1HXCOMM See docs/devel/docs.rst for the format of this file. 2HXCOMM 3HXCOMM Use DEFHEADING() to define headings in both help text and rST. 4HXCOMM Text between SRST and ERST is copied to the rST version and 5HXCOMM discarded from C version. 6HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to 7HXCOMM construct option structures, enums and help message for specified 8HXCOMM architectures. 9HXCOMM HXCOMM can be used for comments, discarded from both rST and C. 10 11DEFHEADING(Standard options:) 12 13DEF("help", 0, QEMU_OPTION_h, 14 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 15SRST 16``-h`` 17 Display help and exit 18ERST 19 20DEF("version", 0, QEMU_OPTION_version, 21 "-version display version information and exit\n", QEMU_ARCH_ALL) 22SRST 23``-version`` 24 Display version information and exit 25ERST 26 27DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 28 "-machine [type=]name[,prop[=value][,...]]\n" 29 " selects emulated machine ('-machine help' for list)\n" 30 " property accel=accel1[:accel2[:...]] selects accelerator\n" 31 " supported accelerators are kvm, xen, hvf, nvmm, whpx or tcg (default: tcg)\n" 32 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 33 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 34 " mem-merge=on|off controls memory merge support (default: on)\n" 35 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 36 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 37 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 38 " nvdimm=on|off controls NVDIMM support (default=off)\n" 39 " memory-encryption=@var{} memory encryption object to use (default=none)\n" 40 " hmat=on|off controls ACPI HMAT support (default=off)\n" 41 " memory-backend='backend-id' specifies explicitly provided backend for main RAM (default=none)\n" 42 " cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]\n", 43 QEMU_ARCH_ALL) 44SRST 45``-machine [type=]name[,prop=value[,...]]`` 46 Select the emulated machine by name. Use ``-machine help`` to list 47 available machines. 48 49 For architectures which aim to support live migration compatibility 50 across releases, each release will introduce a new versioned machine 51 type. For example, the 2.8.0 release introduced machine types 52 "pc-i440fx-2.8" and "pc-q35-2.8" for the x86\_64/i686 architectures. 53 54 To allow live migration of guests from QEMU version 2.8.0, to QEMU 55 version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8" 56 and "pc-q35-2.8" machines too. To allow users live migrating VMs to 57 skip multiple intermediate releases when upgrading, new releases of 58 QEMU will support machine types from many previous versions. 59 60 Supported machine properties are: 61 62 ``accel=accels1[:accels2[:...]]`` 63 This is used to enable an accelerator. Depending on the target 64 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. 65 By default, tcg is used. If there is more than one accelerator 66 specified, the next one is used if the previous one fails to 67 initialize. 68 69 ``vmport=on|off|auto`` 70 Enables emulation of VMWare IO port, for vmmouse etc. auto says 71 to select the value based on accel. For accel=xen the default is 72 off otherwise the default is on. 73 74 ``dump-guest-core=on|off`` 75 Include guest memory in a core dump. The default is on. 76 77 ``mem-merge=on|off`` 78 Enables or disables memory merge support. This feature, when 79 supported by the host, de-duplicates identical memory pages 80 among VMs instances (enabled by default). 81 82 ``aes-key-wrap=on|off`` 83 Enables or disables AES key wrapping support on s390-ccw hosts. 84 This feature controls whether AES wrapping keys will be created 85 to allow execution of AES cryptographic functions. The default 86 is on. 87 88 ``dea-key-wrap=on|off`` 89 Enables or disables DEA key wrapping support on s390-ccw hosts. 90 This feature controls whether DEA wrapping keys will be created 91 to allow execution of DEA cryptographic functions. The default 92 is on. 93 94 ``nvdimm=on|off`` 95 Enables or disables NVDIMM support. The default is off. 96 97 ``memory-encryption=`` 98 Memory encryption object to use. The default is none. 99 100 ``hmat=on|off`` 101 Enables or disables ACPI Heterogeneous Memory Attribute Table 102 (HMAT) support. The default is off. 103 104 ``memory-backend='id'`` 105 An alternative to legacy ``-mem-path`` and ``mem-prealloc`` options. 106 Allows to use a memory backend as main RAM. 107 108 For example: 109 :: 110 111 -object memory-backend-file,id=pc.ram,size=512M,mem-path=/hugetlbfs,prealloc=on,share=on 112 -machine memory-backend=pc.ram 113 -m 512M 114 115 Migration compatibility note: 116 117 * as backend id one shall use value of 'default-ram-id', advertised by 118 machine type (available via ``query-machines`` QMP command), if migration 119 to/from old QEMU (<5.0) is expected. 120 * for machine types 4.0 and older, user shall 121 use ``x-use-canonical-path-for-ramblock-id=off`` backend option 122 if migration to/from old QEMU (<5.0) is expected. 123 124 For example: 125 :: 126 127 -object memory-backend-ram,id=pc.ram,size=512M,x-use-canonical-path-for-ramblock-id=off 128 -machine memory-backend=pc.ram 129 -m 512M 130 131 ``cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]`` 132 Define a CXL Fixed Memory Window (CFMW). 133 134 Described in the CXL 2.0 ECN: CEDT CFMWS & QTG _DSM. 135 136 They are regions of Host Physical Addresses (HPA) on a system which 137 may be interleaved across one or more CXL host bridges. The system 138 software will assign particular devices into these windows and 139 configure the downstream Host-managed Device Memory (HDM) decoders 140 in root ports, switch ports and devices appropriately to meet the 141 interleave requirements before enabling the memory devices. 142 143 ``targets.X=target`` provides the mapping to CXL host bridges 144 which may be identified by the id provided in the -device entry. 145 Multiple entries are needed to specify all the targets when 146 the fixed memory window represents interleaved memory. X is the 147 target index from 0. 148 149 ``size=size`` sets the size of the CFMW. This must be a multiple of 150 256MiB. The region will be aligned to 256MiB but the location is 151 platform and configuration dependent. 152 153 ``interleave-granularity=granularity`` sets the granularity of 154 interleave. Default 256KiB. Only 256KiB, 512KiB, 1024KiB, 2048KiB 155 4096KiB, 8192KiB and 16384KiB granularities supported. 156 157 Example: 158 159 :: 160 161 -machine cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=128G,cxl-fmw.0.interleave-granularity=512k 162ERST 163 164DEF("M", HAS_ARG, QEMU_OPTION_M, 165 " sgx-epc.0.memdev=memid,sgx-epc.0.node=numaid\n", 166 QEMU_ARCH_ALL) 167 168SRST 169``sgx-epc.0.memdev=@var{memid},sgx-epc.0.node=@var{numaid}`` 170 Define an SGX EPC section. 171ERST 172 173DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 174 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 175SRST 176``-cpu model`` 177 Select CPU model (``-cpu help`` for list and additional feature 178 selection) 179ERST 180 181DEF("accel", HAS_ARG, QEMU_OPTION_accel, 182 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 183 " select accelerator (kvm, xen, hvf, nvmm, whpx or tcg; use 'help' for a list)\n" 184 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 185 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" 186 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 187 " one-insn-per-tb=on|off (one guest instruction per TCG translation block)\n" 188 " split-wx=on|off (enable TCG split w^x mapping)\n" 189 " tb-size=n (TCG translation block cache size)\n" 190 " dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n" 191 " eager-split-size=n (KVM Eager Page Split chunk size, default 0, disabled. ARM only)\n" 192 " notify-vmexit=run|internal-error|disable,notify-window=n (enable notify VM exit and set notify window, x86 only)\n" 193 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 194SRST 195``-accel name[,prop=value[,...]]`` 196 This is used to enable an accelerator. Depending on the target 197 architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. By 198 default, tcg is used. If there is more than one accelerator 199 specified, the next one is used if the previous one fails to 200 initialize. 201 202 ``igd-passthru=on|off`` 203 When Xen is in use, this option controls whether Intel 204 integrated graphics devices can be passed through to the guest 205 (default=off) 206 207 ``kernel-irqchip=on|off|split`` 208 Controls KVM in-kernel irqchip support. The default is full 209 acceleration of the interrupt controllers. On x86, split irqchip 210 reduces the kernel attack surface, at a performance cost for 211 non-MSI interrupts. Disabling the in-kernel irqchip completely 212 is not recommended except for debugging purposes. 213 214 ``kvm-shadow-mem=size`` 215 Defines the size of the KVM shadow MMU. 216 217 ``one-insn-per-tb=on|off`` 218 Makes the TCG accelerator put only one guest instruction into 219 each translation block. This slows down emulation a lot, but 220 can be useful in some situations, such as when trying to analyse 221 the logs produced by the ``-d`` option. 222 223 ``split-wx=on|off`` 224 Controls the use of split w^x mapping for the TCG code generation 225 buffer. Some operating systems require this to be enabled, and in 226 such a case this will default on. On other operating systems, this 227 will default off, but one may enable this for testing or debugging. 228 229 ``tb-size=n`` 230 Controls the size (in MiB) of the TCG translation block cache. 231 232 ``thread=single|multi`` 233 Controls number of TCG threads. When the TCG is multi-threaded 234 there will be one thread per vCPU therefore taking advantage of 235 additional host cores. The default is to enable multi-threading 236 where both the back-end and front-ends support it and no 237 incompatible TCG features have been enabled (e.g. 238 icount/replay). 239 240 ``dirty-ring-size=n`` 241 When the KVM accelerator is used, it controls the size of the per-vCPU 242 dirty page ring buffer (number of entries for each vCPU). It should 243 be a value that is power of two, and it should be 1024 or bigger (but 244 still less than the maximum value that the kernel supports). 4096 245 could be a good initial value if you have no idea which is the best. 246 Set this value to 0 to disable the feature. By default, this feature 247 is disabled (dirty-ring-size=0). When enabled, KVM will instead 248 record dirty pages in a bitmap. 249 250 ``eager-split-size=n`` 251 KVM implements dirty page logging at the PAGE_SIZE granularity and 252 enabling dirty-logging on a huge-page requires breaking it into 253 PAGE_SIZE pages in the first place. KVM on ARM does this splitting 254 lazily by default. There are performance benefits in doing huge-page 255 split eagerly, especially in situations where TLBI costs associated 256 with break-before-make sequences are considerable and also if guest 257 workloads are read intensive. The size here specifies how many pages 258 to break at a time and needs to be a valid block size which is 259 1GB/2MB/4KB, 32MB/16KB and 512MB/64KB for 4KB/16KB/64KB PAGE_SIZE 260 respectively. Be wary of specifying a higher size as it will have an 261 impact on the memory. By default, this feature is disabled 262 (eager-split-size=0). 263 264 ``notify-vmexit=run|internal-error|disable,notify-window=n`` 265 Enables or disables notify VM exit support on x86 host and specify 266 the corresponding notify window to trigger the VM exit if enabled. 267 ``run`` option enables the feature. It does nothing and continue 268 if the exit happens. ``internal-error`` option enables the feature. 269 It raises a internal error. ``disable`` option doesn't enable the feature. 270 This feature can mitigate the CPU stuck issue due to event windows don't 271 open up for a specified of time (i.e. notify-window). 272 Default: notify-vmexit=run,notify-window=0. 273 274ERST 275 276DEF("smp", HAS_ARG, QEMU_OPTION_smp, 277 "-smp [[cpus=]n][,maxcpus=maxcpus][,drawers=drawers][,books=books][,sockets=sockets]\n" 278 " [,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]\n" 279 " set the number of initial CPUs to 'n' [default=1]\n" 280 " maxcpus= maximum number of total CPUs, including\n" 281 " offline CPUs for hotplug, etc\n" 282 " drawers= number of drawers on the machine board\n" 283 " books= number of books in one drawer\n" 284 " sockets= number of sockets in one book\n" 285 " dies= number of dies in one socket\n" 286 " clusters= number of clusters in one die\n" 287 " cores= number of cores in one cluster\n" 288 " threads= number of threads in one core\n" 289 "Note: Different machines may have different subsets of the CPU topology\n" 290 " parameters supported, so the actual meaning of the supported parameters\n" 291 " will vary accordingly. For example, for a machine type that supports a\n" 292 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n" 293 " sequentially mean as below:\n" 294 " sockets means the number of sockets on the machine board\n" 295 " cores means the number of cores in one socket\n" 296 " threads means the number of threads in one core\n" 297 " For a particular machine type board, an expected CPU topology hierarchy\n" 298 " can be defined through the supported sub-option. Unsupported parameters\n" 299 " can also be provided in addition to the sub-option, but their values\n" 300 " must be set as 1 in the purpose of correct parsing.\n", 301 QEMU_ARCH_ALL) 302SRST 303``-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]`` 304 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on 305 the machine type board. On boards supporting CPU hotplug, the optional 306 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be 307 added at runtime. When both parameters are omitted, the maximum number 308 of CPUs will be calculated from the provided topology members and the 309 initial CPU count will match the maximum number. When only one of them 310 is given then the omitted one will be set to its counterpart's value. 311 Both parameters may be specified, but the maximum number of CPUs must 312 be equal to or greater than the initial CPU count. Product of the 313 CPU topology hierarchy must be equal to the maximum number of CPUs. 314 Both parameters are subject to an upper limit that is determined by 315 the specific machine type chosen. 316 317 To control reporting of CPU topology information, values of the topology 318 parameters can be specified. Machines may only support a subset of the 319 parameters and different machines may have different subsets supported 320 which vary depending on capacity of the corresponding CPU targets. So 321 for a particular machine type board, an expected topology hierarchy can 322 be defined through the supported sub-option. Unsupported parameters can 323 also be provided in addition to the sub-option, but their values must be 324 set as 1 in the purpose of correct parsing. 325 326 Either the initial CPU count, or at least one of the topology parameters 327 must be specified. The specified parameters must be greater than zero, 328 explicit configuration like "cpus=0" is not allowed. Values for any 329 omitted parameters will be computed from those which are given. 330 331 For example, the following sub-option defines a CPU topology hierarchy 332 (2 sockets totally on the machine, 2 cores per socket, 2 threads per 333 core) for a machine that only supports sockets/cores/threads. 334 Some members of the option can be omitted but their values will be 335 automatically computed: 336 337 :: 338 339 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8 340 341 The following sub-option defines a CPU topology hierarchy (2 sockets 342 totally on the machine, 2 dies per socket, 2 cores per die, 2 threads 343 per core) for PC machines which support sockets/dies/cores/threads. 344 Some members of the option can be omitted but their values will be 345 automatically computed: 346 347 :: 348 349 -smp 16,sockets=2,dies=2,cores=2,threads=2,maxcpus=16 350 351 The following sub-option defines a CPU topology hierarchy (2 sockets 352 totally on the machine, 2 clusters per socket, 2 cores per cluster, 353 2 threads per core) for ARM virt machines which support sockets/clusters 354 /cores/threads. Some members of the option can be omitted but their values 355 will be automatically computed: 356 357 :: 358 359 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16 360 361 Historically preference was given to the coarsest topology parameters 362 when computing missing values (ie sockets preferred over cores, which 363 were preferred over threads), however, this behaviour is considered 364 liable to change. Prior to 6.2 the preference was sockets over cores 365 over threads. Since 6.2 the preference is cores over sockets over threads. 366 367 For example, the following option defines a machine board with 2 sockets 368 of 1 core before 6.2 and 1 socket of 2 cores after 6.2: 369 370 :: 371 372 -smp 2 373 374 Note: The cluster topology will only be generated in ACPI and exposed 375 to guest if it's explicitly specified in -smp. 376ERST 377 378DEF("numa", HAS_ARG, QEMU_OPTION_numa, 379 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 380 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n" 381 "-numa dist,src=source,dst=destination,val=distance\n" 382 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n" 383 "-numa hmat-lb,initiator=node,target=node,hierarchy=memory|first-level|second-level|third-level,data-type=access-latency|read-latency|write-latency[,latency=lat][,bandwidth=bw]\n" 384 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n", 385 QEMU_ARCH_ALL) 386SRST 387``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 388 \ 389``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]`` 390 \ 391``-numa dist,src=source,dst=destination,val=distance`` 392 \ 393``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]`` 394 \ 395``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=type[,latency=lat][,bandwidth=bw]`` 396 \ 397``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]`` 398 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA 399 distance from a source node to a destination node. Set the ACPI 400 Heterogeneous Memory Attributes for the given nodes. 401 402 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and 403 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a 404 contiguous range of CPU indexes (or a single VCPU if lastcpu is 405 omitted). A non-contiguous set of VCPUs can be represented by 406 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is 407 omitted on all nodes, VCPUs are automatically split between them. 408 409 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a 410 NUMA node: 411 412 :: 413 414 -numa node,cpus=0-2,cpus=5 415 416 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option 417 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to 418 assign CPU objects to a node using topology layout properties of 419 CPU. The set of properties is machine specific, and depends on used 420 machine type/'\ ``smp``\ ' options. It could be queried with 421 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ ' 422 property specifies node to which CPU object will be assigned, it's 423 required for node to be declared with '\ ``node``\ ' option before 424 it's used with '\ ``cpu``\ ' option. 425 426 For example: 427 428 :: 429 430 -M pc \ 431 -smp 1,sockets=2,maxcpus=2 \ 432 -numa node,nodeid=0 -numa node,nodeid=1 \ 433 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 434 435 '\ ``memdev``\ ' option assigns RAM from a given memory backend 436 device to a node. It is recommended to use '\ ``memdev``\ ' option 437 over legacy '\ ``mem``\ ' option. This is because '\ ``memdev``\ ' 438 option provides better performance and more control over the 439 backend's RAM (e.g. '\ ``prealloc``\ ' parameter of 440 '\ ``-memory-backend-ram``\ ' allows memory preallocation). 441 442 For compatibility reasons, legacy '\ ``mem``\ ' option is 443 supported in 5.0 and older machine types. Note that '\ ``mem``\ ' 444 and '\ ``memdev``\ ' are mutually exclusive. If one node uses 445 '\ ``memdev``\ ', the rest nodes have to use '\ ``memdev``\ ' 446 option, and vice versa. 447 448 Users must specify memory for all NUMA nodes by '\ ``memdev``\ ' 449 (or legacy '\ ``mem``\ ' if available). In QEMU 5.2, the support 450 for '\ ``-numa node``\ ' without memory specified was removed. 451 452 '\ ``initiator``\ ' is an additional option that points to an 453 initiator NUMA node that has best performance (the lowest latency or 454 largest bandwidth) to this NUMA node. Note that this option can be 455 set only when the machine property 'hmat' is set to 'on'. 456 457 Following example creates a machine with 2 NUMA nodes, node 0 has 458 CPU. node 1 has only memory, and its initiator is node 0. Note that 459 because node 0 has CPU, by default the initiator of node 0 is itself 460 and must be itself. 461 462 :: 463 464 -machine hmat=on \ 465 -m 2G,slots=2,maxmem=4G \ 466 -object memory-backend-ram,size=1G,id=m0 \ 467 -object memory-backend-ram,size=1G,id=m1 \ 468 -numa node,nodeid=0,memdev=m0 \ 469 -numa node,nodeid=1,memdev=m1,initiator=0 \ 470 -smp 2,sockets=2,maxcpus=2 \ 471 -numa cpu,node-id=0,socket-id=0 \ 472 -numa cpu,node-id=0,socket-id=1 473 474 source and destination are NUMA node IDs. distance is the NUMA 475 distance from source to destination. The distance from a node to 476 itself is always 10. If any pair of nodes is given a distance, then 477 all pairs must be given distances. Although, when distances are only 478 given in one direction for each pair of nodes, then the distances in 479 the opposite directions are assumed to be the same. If, however, an 480 asymmetrical pair of distances is given for even one node pair, then 481 all node pairs must be provided distance values for both directions, 482 even when they are symmetrical. When a node is unreachable from 483 another node, set the pair's distance to 255. 484 485 Note that the -``numa`` option doesn't allocate any of the specified 486 resources, it just assigns existing resources to NUMA nodes. This 487 means that one still has to use the ``-m``, ``-smp`` options to 488 allocate RAM and VCPUs respectively. 489 490 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth 491 Information between initiator and target NUMA nodes in ACPI 492 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can 493 create memory requests, usually it has one or more processors. 494 Target NUMA node contains addressable memory. 495 496 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is 497 the memory hierarchy of the target NUMA node: if hierarchy is 498 'memory', the structure represents the memory performance; if 499 hierarchy is 'first-level\|second-level\|third-level', this 500 structure represents aggregated performance of memory side caches 501 for each domain. type of 'data-type' is type of data represented by 502 this structure instance: if 'hierarchy' is 'memory', 'data-type' is 503 'access\|read\|write' latency or 'access\|read\|write' bandwidth of 504 the target memory; if 'hierarchy' is 505 'first-level\|second-level\|third-level', 'data-type' is 506 'access\|read\|write' hit latency or 'access\|read\|write' hit 507 bandwidth of the target memory side cache. 508 509 lat is latency value in nanoseconds. bw is bandwidth value, the 510 possible value and units are NUM[M\|G\|T], mean that the bandwidth 511 value are NUM byte per second (or MB/s, GB/s or TB/s depending on 512 used suffix). Note that if latency or bandwidth value is 0, means 513 the corresponding latency or bandwidth information is not provided. 514 515 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory 516 belongs. size is the size of memory side cache in bytes. level is 517 the cache level described in this structure, note that the cache 518 level 0 should not be used with '\ ``hmat-cache``\ ' option. 519 associativity is the cache associativity, the possible value is 520 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy 521 is the write policy. line is the cache Line size in bytes. 522 523 For example, the following options describe 2 NUMA nodes. Node 0 has 524 2 cpus and a ram, node 1 has only a ram. The processors in node 0 525 access memory in node 0 with access-latency 5 nanoseconds, 526 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access 527 memory in NUMA node 1 with access-latency 10 nanoseconds, 528 access-bandwidth is 100 MB/s. And for memory side cache information, 529 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB, 530 policy is write-back, the cache Line size is 8 bytes: 531 532 :: 533 534 -machine hmat=on \ 535 -m 2G \ 536 -object memory-backend-ram,size=1G,id=m0 \ 537 -object memory-backend-ram,size=1G,id=m1 \ 538 -smp 2,sockets=2,maxcpus=2 \ 539 -numa node,nodeid=0,memdev=m0 \ 540 -numa node,nodeid=1,memdev=m1,initiator=0 \ 541 -numa cpu,node-id=0,socket-id=0 \ 542 -numa cpu,node-id=0,socket-id=1 \ 543 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \ 544 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \ 545 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \ 546 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \ 547 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \ 548 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8 549ERST 550 551DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 552 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 553 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 554SRST 555``-add-fd fd=fd,set=set[,opaque=opaque]`` 556 Add a file descriptor to an fd set. Valid options are: 557 558 ``fd=fd`` 559 This option defines the file descriptor of which a duplicate is 560 added to fd set. The file descriptor cannot be stdin, stdout, or 561 stderr. 562 563 ``set=set`` 564 This option defines the ID of the fd set to add the file 565 descriptor to. 566 567 ``opaque=opaque`` 568 This option defines a free-form string that can be used to 569 describe fd. 570 571 You can open an image using pre-opened file descriptors from an fd 572 set: 573 574 .. parsed-literal:: 575 576 |qemu_system| \\ 577 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 578 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 579 -drive file=/dev/fdset/2,index=0,media=disk 580ERST 581 582DEF("set", HAS_ARG, QEMU_OPTION_set, 583 "-set group.id.arg=value\n" 584 " set <arg> parameter for item <id> of type <group>\n" 585 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 586SRST 587``-set group.id.arg=value`` 588 Set parameter arg for item id of type group 589ERST 590 591DEF("global", HAS_ARG, QEMU_OPTION_global, 592 "-global driver.property=value\n" 593 "-global driver=driver,property=property,value=value\n" 594 " set a global default for a driver property\n", 595 QEMU_ARCH_ALL) 596SRST 597``-global driver.prop=value`` 598 \ 599``-global driver=driver,property=property,value=value`` 600 Set default value of driver's property prop to value, e.g.: 601 602 .. parsed-literal:: 603 604 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img 605 606 In particular, you can use this to set driver properties for devices 607 which are created automatically by the machine model. To create a 608 device which is not created automatically and set properties on it, 609 use -``device``. 610 611 -global driver.prop=value is shorthand for -global 612 driver=driver,property=prop,value=value. The longhand syntax works 613 even when driver contains a dot. 614ERST 615 616DEF("boot", HAS_ARG, QEMU_OPTION_boot, 617 "-boot [order=drives][,once=drives][,menu=on|off]\n" 618 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 619 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 620 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 621 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 622 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 623 QEMU_ARCH_ALL) 624SRST 625``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]`` 626 Specify boot order drives as a string of drive letters. Valid drive 627 letters depend on the target architecture. The x86 PC uses: a, b 628 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p 629 (Etherboot from network adapter 1-4), hard disk boot is the default. 630 To apply a particular boot order only on the first startup, specify 631 it via ``once``. Note that the ``order`` or ``once`` parameter 632 should not be used together with the ``bootindex`` property of 633 devices, since the firmware implementations normally do not support 634 both at the same time. 635 636 Interactive boot menus/prompts can be enabled via ``menu=on`` as far 637 as firmware/BIOS supports them. The default is non-interactive boot. 638 639 A splash picture could be passed to bios, enabling user to show it 640 as logo, when option splash=sp\_name is given and menu=on, If 641 firmware/BIOS supports them. Currently Seabios for X86 system 642 support it. limitation: The splash file could be a jpeg file or a 643 BMP file in 24 BPP format(true color). The resolution should be 644 supported by the SVGA mode, so the recommended is 320x240, 640x480, 645 800x640. 646 647 A timeout could be passed to bios, guest will pause for rb\_timeout 648 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will 649 not reboot, qemu passes '-1' to bios by default. Currently Seabios 650 for X86 system support it. 651 652 Do strict boot via ``strict=on`` as far as firmware/BIOS supports 653 it. This only effects when boot priority is changed by bootindex 654 options. The default is non-strict boot. 655 656 .. parsed-literal:: 657 658 # try to boot from network first, then from hard disk 659 |qemu_system_x86| -boot order=nc 660 # boot from CD-ROM first, switch back to default order after reboot 661 |qemu_system_x86| -boot once=d 662 # boot with a splash picture for 5 seconds. 663 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000 664 665 Note: The legacy format '-boot drives' is still supported but its 666 use is discouraged as it may be removed from future versions. 667ERST 668 669DEF("m", HAS_ARG, QEMU_OPTION_m, 670 "-m [size=]megs[,slots=n,maxmem=size]\n" 671 " configure guest RAM\n" 672 " size: initial amount of guest memory\n" 673 " slots: number of hotplug slots (default: none)\n" 674 " maxmem: maximum amount of guest memory (default: none)\n" 675 " Note: Some architectures might enforce a specific granularity\n", 676 QEMU_ARCH_ALL) 677SRST 678``-m [size=]megs[,slots=n,maxmem=size]`` 679 Sets guest startup RAM size to megs megabytes. Default is 128 MiB. 680 Optionally, a suffix of "M" or "G" can be used to signify a value in 681 megabytes or gigabytes respectively. Optional pair slots, maxmem 682 could be used to set amount of hotpluggable memory slots and maximum 683 amount of memory. Note that maxmem must be aligned to the page size. 684 685 For example, the following command-line sets the guest startup RAM 686 size to 1GB, creates 3 slots to hotplug additional memory and sets 687 the maximum memory the guest can reach to 4GB: 688 689 .. parsed-literal:: 690 691 |qemu_system| -m 1G,slots=3,maxmem=4G 692 693 If slots and maxmem are not specified, memory hotplug won't be 694 enabled and the guest startup RAM will never increase. 695ERST 696 697DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 698 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 699SRST 700``-mem-path path`` 701 Allocate guest RAM from a temporarily created file in path. 702ERST 703 704DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 705 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 706 QEMU_ARCH_ALL) 707SRST 708``-mem-prealloc`` 709 Preallocate memory when using -mem-path. 710ERST 711 712DEF("k", HAS_ARG, QEMU_OPTION_k, 713 "-k language use keyboard layout (for example 'fr' for French)\n", 714 QEMU_ARCH_ALL) 715SRST 716``-k language`` 717 Use keyboard layout language (for example ``fr`` for French). This 718 option is only needed where it is not easy to get raw PC keycodes 719 (e.g. on Macs, with some X11 servers or with a VNC or curses 720 display). You don't normally need to use it on PC/Linux or 721 PC/Windows hosts. 722 723 The available layouts are: 724 725 :: 726 727 ar de-ch es fo fr-ca hu ja mk no pt-br sv 728 da en-gb et fr fr-ch is lt nl pl ru th 729 de en-us fi fr-be hr it lv nl-be pt sl tr 730 731 The default is ``en-us``. 732ERST 733 734 735DEF("audio", HAS_ARG, QEMU_OPTION_audio, 736 "-audio [driver=]driver[,prop[=value][,...]]\n" 737 " specifies default audio backend when `audiodev` is not\n" 738 " used to create a machine or sound device;" 739 " options are the same as for -audiodev\n" 740 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n" 741 " specifies the audio backend and device to use;\n" 742 " apart from 'model', options are the same as for -audiodev.\n" 743 " use '-audio model=help' to show possible devices.\n", 744 QEMU_ARCH_ALL) 745SRST 746``-audio [driver=]driver[,model=value][,prop[=value][,...]]`` 747 If the ``model`` option is specified, ``-audio`` is a shortcut 748 for configuring both the guest audio hardware and the host audio 749 backend in one go. The guest hardware model can be set with 750 ``model=modelname``. Use ``model=help`` to list the available 751 device types. 752 753 The following two example do exactly the same, to show how ``-audio`` 754 can be used to shorten the command line length: 755 756 .. parsed-literal:: 757 758 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa 759 |qemu_system| -audio pa,model=sb16 760 761 If the ``model`` option is not specified, ``-audio`` is used to 762 configure a default audio backend that will be used whenever the 763 ``audiodev`` property is not set on a device or machine. In 764 particular, ``-audio none`` ensures that no audio is produced even 765 for machines that have embedded sound hardware. 766 767 In both cases, the driver option is the same as with the corresponding 768 ``-audiodev`` option below. Use ``driver=help`` to list the available 769 drivers. 770 771ERST 772 773DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 774 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 775 " specifies the audio backend to use\n" 776 " Use ``-audiodev help`` to list the available drivers\n" 777 " id= identifier of the backend\n" 778 " timer-period= timer period in microseconds\n" 779 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 780 " in|out.fixed-settings= use fixed settings for host audio\n" 781 " in|out.frequency= frequency to use with fixed settings\n" 782 " in|out.channels= number of channels to use with fixed settings\n" 783 " in|out.format= sample format to use with fixed settings\n" 784 " valid values: s8, s16, s32, u8, u16, u32, f32\n" 785 " in|out.voices= number of voices to use\n" 786 " in|out.buffer-length= length of buffer in microseconds\n" 787 "-audiodev none,id=id,[,prop[=value][,...]]\n" 788 " dummy driver that discards all output\n" 789#ifdef CONFIG_AUDIO_ALSA 790 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 791 " in|out.dev= name of the audio device to use\n" 792 " in|out.period-length= length of period in microseconds\n" 793 " in|out.try-poll= attempt to use poll mode\n" 794 " threshold= threshold (in microseconds) when playback starts\n" 795#endif 796#ifdef CONFIG_AUDIO_COREAUDIO 797 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 798 " in|out.buffer-count= number of buffers\n" 799#endif 800#ifdef CONFIG_AUDIO_DSOUND 801 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 802 " latency= add extra latency to playback in microseconds\n" 803#endif 804#ifdef CONFIG_AUDIO_OSS 805 "-audiodev oss,id=id[,prop[=value][,...]]\n" 806 " in|out.dev= path of the audio device to use\n" 807 " in|out.buffer-count= number of buffers\n" 808 " in|out.try-poll= attempt to use poll mode\n" 809 " try-mmap= try using memory mapped access\n" 810 " exclusive= open device in exclusive mode\n" 811 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 812#endif 813#ifdef CONFIG_AUDIO_PA 814 "-audiodev pa,id=id[,prop[=value][,...]]\n" 815 " server= PulseAudio server address\n" 816 " in|out.name= source/sink device name\n" 817 " in|out.latency= desired latency in microseconds\n" 818#endif 819#ifdef CONFIG_AUDIO_PIPEWIRE 820 "-audiodev pipewire,id=id[,prop[=value][,...]]\n" 821 " in|out.name= source/sink device name\n" 822 " in|out.stream-name= name of pipewire stream\n" 823 " in|out.latency= desired latency in microseconds\n" 824#endif 825#ifdef CONFIG_AUDIO_SDL 826 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 827 " in|out.buffer-count= number of buffers\n" 828#endif 829#ifdef CONFIG_AUDIO_SNDIO 830 "-audiodev sndio,id=id[,prop[=value][,...]]\n" 831#endif 832#ifdef CONFIG_SPICE 833 "-audiodev spice,id=id[,prop[=value][,...]]\n" 834#endif 835#ifdef CONFIG_DBUS_DISPLAY 836 "-audiodev dbus,id=id[,prop[=value][,...]]\n" 837#endif 838 "-audiodev wav,id=id[,prop[=value][,...]]\n" 839 " path= path of wav file to record\n", 840 QEMU_ARCH_ALL) 841SRST 842``-audiodev [driver=]driver,id=id[,prop[=value][,...]]`` 843 Adds a new audio backend driver identified by id. There are global 844 and driver specific properties. Some values can be set differently 845 for input and output, they're marked with ``in|out.``. You can set 846 the input's property with ``in.prop`` and the output's property with 847 ``out.prop``. For example: 848 849 :: 850 851 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 852 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 853 854 NOTE: parameter validation is known to be incomplete, in many cases 855 specifying an invalid option causes QEMU to print an error message 856 and continue emulation without sound. 857 858 Valid global options are: 859 860 ``id=identifier`` 861 Identifies the audio backend. 862 863 ``timer-period=period`` 864 Sets the timer period used by the audio subsystem in 865 microseconds. Default is 10000 (10 ms). 866 867 ``in|out.mixing-engine=on|off`` 868 Use QEMU's mixing engine to mix all streams inside QEMU and 869 convert audio formats when not supported by the backend. When 870 off, fixed-settings must be off too. Note that disabling this 871 option means that the selected backend must support multiple 872 streams and the audio formats used by the virtual cards, 873 otherwise you'll get no sound. It's not recommended to disable 874 this option unless you want to use 5.1 or 7.1 audio, as mixing 875 engine only supports mono and stereo audio. Default is on. 876 877 ``in|out.fixed-settings=on|off`` 878 Use fixed settings for host audio. When off, it will change 879 based on how the guest opens the sound card. In this case you 880 must not specify frequency, channels or format. Default is on. 881 882 ``in|out.frequency=frequency`` 883 Specify the frequency to use when using fixed-settings. Default 884 is 44100Hz. 885 886 ``in|out.channels=channels`` 887 Specify the number of channels to use when using fixed-settings. 888 Default is 2 (stereo). 889 890 ``in|out.format=format`` 891 Specify the sample format to use when using fixed-settings. 892 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``, 893 ``u32``, ``f32``. Default is ``s16``. 894 895 ``in|out.voices=voices`` 896 Specify the number of voices to use. Default is 1. 897 898 ``in|out.buffer-length=usecs`` 899 Sets the size of the buffer in microseconds. 900 901``-audiodev none,id=id[,prop[=value][,...]]`` 902 Creates a dummy backend that discards all outputs. This backend has 903 no backend specific properties. 904 905``-audiodev alsa,id=id[,prop[=value][,...]]`` 906 Creates backend using the ALSA. This backend is only available on 907 Linux. 908 909 ALSA specific options are: 910 911 ``in|out.dev=device`` 912 Specify the ALSA device to use for input and/or output. Default 913 is ``default``. 914 915 ``in|out.period-length=usecs`` 916 Sets the period length in microseconds. 917 918 ``in|out.try-poll=on|off`` 919 Attempt to use poll mode with the device. Default is on. 920 921 ``threshold=threshold`` 922 Threshold (in microseconds) when playback starts. Default is 0. 923 924``-audiodev coreaudio,id=id[,prop[=value][,...]]`` 925 Creates a backend using Apple's Core Audio. This backend is only 926 available on Mac OS and only supports playback. 927 928 Core Audio specific options are: 929 930 ``in|out.buffer-count=count`` 931 Sets the count of the buffers. 932 933``-audiodev dsound,id=id[,prop[=value][,...]]`` 934 Creates a backend using Microsoft's DirectSound. This backend is 935 only available on Windows and only supports playback. 936 937 DirectSound specific options are: 938 939 ``latency=usecs`` 940 Add extra usecs microseconds latency to playback. Default is 941 10000 (10 ms). 942 943``-audiodev oss,id=id[,prop[=value][,...]]`` 944 Creates a backend using OSS. This backend is available on most 945 Unix-like systems. 946 947 OSS specific options are: 948 949 ``in|out.dev=device`` 950 Specify the file name of the OSS device to use. Default is 951 ``/dev/dsp``. 952 953 ``in|out.buffer-count=count`` 954 Sets the count of the buffers. 955 956 ``in|out.try-poll=on|of`` 957 Attempt to use poll mode with the device. Default is on. 958 959 ``try-mmap=on|off`` 960 Try using memory mapped device access. Default is off. 961 962 ``exclusive=on|off`` 963 Open the device in exclusive mode (vmix won't work in this 964 case). Default is off. 965 966 ``dsp-policy=policy`` 967 Sets the timing policy (between 0 and 10, where smaller number 968 means smaller latency but higher CPU usage). Use -1 to use 969 buffer sizes specified by ``buffer`` and ``buffer-count``. This 970 option is ignored if you do not have OSS 4. Default is 5. 971 972``-audiodev pa,id=id[,prop[=value][,...]]`` 973 Creates a backend using PulseAudio. This backend is available on 974 most systems. 975 976 PulseAudio specific options are: 977 978 ``server=server`` 979 Sets the PulseAudio server to connect to. 980 981 ``in|out.name=sink`` 982 Use the specified source/sink for recording/playback. 983 984 ``in|out.latency=usecs`` 985 Desired latency in microseconds. The PulseAudio server will try 986 to honor this value but actual latencies may be lower or higher. 987 988``-audiodev pipewire,id=id[,prop[=value][,...]]`` 989 Creates a backend using PipeWire. This backend is available on 990 most systems. 991 992 PipeWire specific options are: 993 994 ``in|out.latency=usecs`` 995 Desired latency in microseconds. 996 997 ``in|out.name=sink`` 998 Use the specified source/sink for recording/playback. 999 1000 ``in|out.stream-name`` 1001 Specify the name of pipewire stream. 1002 1003``-audiodev sdl,id=id[,prop[=value][,...]]`` 1004 Creates a backend using SDL. This backend is available on most 1005 systems, but you should use your platform's native backend if 1006 possible. 1007 1008 SDL specific options are: 1009 1010 ``in|out.buffer-count=count`` 1011 Sets the count of the buffers. 1012 1013``-audiodev sndio,id=id[,prop[=value][,...]]`` 1014 Creates a backend using SNDIO. This backend is available on 1015 OpenBSD and most other Unix-like systems. 1016 1017 Sndio specific options are: 1018 1019 ``in|out.dev=device`` 1020 Specify the sndio device to use for input and/or output. Default 1021 is ``default``. 1022 1023 ``in|out.latency=usecs`` 1024 Sets the desired period length in microseconds. 1025 1026``-audiodev spice,id=id[,prop[=value][,...]]`` 1027 Creates a backend that sends audio through SPICE. This backend 1028 requires ``-spice`` and automatically selected in that case, so 1029 usually you can ignore this option. This backend has no backend 1030 specific properties. 1031 1032``-audiodev wav,id=id[,prop[=value][,...]]`` 1033 Creates a backend that writes audio to a WAV file. 1034 1035 Backend specific options are: 1036 1037 ``path=path`` 1038 Write recorded audio into the specified file. Default is 1039 ``qemu.wav``. 1040ERST 1041 1042DEF("device", HAS_ARG, QEMU_OPTION_device, 1043 "-device driver[,prop[=value][,...]]\n" 1044 " add device (based on driver)\n" 1045 " prop=value,... sets driver properties\n" 1046 " use '-device help' to print all possible drivers\n" 1047 " use '-device driver,help' to print all possible properties\n", 1048 QEMU_ARCH_ALL) 1049SRST 1050``-device driver[,prop[=value][,...]]`` 1051 Add device driver. prop=value sets driver properties. Valid 1052 properties depend on the driver. To get help on possible drivers and 1053 properties, use ``-device help`` and ``-device driver,help``. 1054 1055 Some drivers are: 1056 1057``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]`` 1058 Add an IPMI BMC. This is a simulation of a hardware management 1059 interface processor that normally sits on a system. It provides a 1060 watchdog and the ability to reset and power control the system. You 1061 need to connect this to an IPMI interface to make it useful 1062 1063 The IPMI slave address to use for the BMC. The default is 0x20. This 1064 address is the BMC's address on the I2C network of management 1065 controllers. If you don't know what this means, it is safe to ignore 1066 it. 1067 1068 ``id=id`` 1069 The BMC id for interfaces to use this device. 1070 1071 ``slave_addr=val`` 1072 Define slave address to use for the BMC. The default is 0x20. 1073 1074 ``sdrfile=file`` 1075 file containing raw Sensor Data Records (SDR) data. The default 1076 is none. 1077 1078 ``fruareasize=val`` 1079 size of a Field Replaceable Unit (FRU) area. The default is 1080 1024. 1081 1082 ``frudatafile=file`` 1083 file containing raw Field Replaceable Unit (FRU) inventory data. 1084 The default is none. 1085 1086 ``guid=uuid`` 1087 value for the GUID for the BMC, in standard UUID format. If this 1088 is set, get "Get GUID" command to the BMC will return it. 1089 Otherwise "Get GUID" will return an error. 1090 1091``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]`` 1092 Add a connection to an external IPMI BMC simulator. Instead of 1093 locally emulating the BMC like the above item, instead connect to an 1094 external entity that provides the IPMI services. 1095 1096 A connection is made to an external BMC simulator. If you do this, 1097 it is strongly recommended that you use the "reconnect=" chardev 1098 option to reconnect to the simulator if the connection is lost. Note 1099 that if this is not used carefully, it can be a security issue, as 1100 the interface has the ability to send resets, NMIs, and power off 1101 the VM. It's best if QEMU makes a connection to an external 1102 simulator running on a secure port on localhost, so neither the 1103 simulator nor QEMU is exposed to any outside network. 1104 1105 See the "lanserv/README.vm" file in the OpenIPMI library for more 1106 details on the external interface. 1107 1108``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]`` 1109 Add a KCS IPMI interface on the ISA bus. This also adds a 1110 corresponding ACPI and SMBIOS entries, if appropriate. 1111 1112 ``bmc=id`` 1113 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern 1114 above. 1115 1116 ``ioport=val`` 1117 Define the I/O address of the interface. The default is 0xca0 1118 for KCS. 1119 1120 ``irq=val`` 1121 Define the interrupt to use. The default is 5. To disable 1122 interrupts, set this to 0. 1123 1124``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]`` 1125 Like the KCS interface, but defines a BT interface. The default port 1126 is 0xe4 and the default interrupt is 5. 1127 1128``-device pci-ipmi-kcs,bmc=id`` 1129 Add a KCS IPMI interface on the PCI bus. 1130 1131 ``bmc=id`` 1132 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 1133 1134``-device pci-ipmi-bt,bmc=id`` 1135 Like the KCS interface, but defines a BT interface on the PCI bus. 1136 1137``-device intel-iommu[,option=...]`` 1138 This is only supported by ``-machine q35``, which will enable Intel VT-d 1139 emulation within the guest. It supports below options: 1140 1141 ``intremap=on|off`` (default: auto) 1142 This enables interrupt remapping feature. It's required to enable 1143 complete x2apic. Currently it only supports kvm kernel-irqchip modes 1144 ``off`` or ``split``, while full kernel-irqchip is not yet supported. 1145 The default value is "auto", which will be decided by the mode of 1146 kernel-irqchip. 1147 1148 ``caching-mode=on|off`` (default: off) 1149 This enables caching mode for the VT-d emulated device. When 1150 caching-mode is enabled, each guest DMA buffer mapping will generate an 1151 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in 1152 a synchronous way. It is required for ``-device vfio-pci`` to work 1153 with the VT-d device, because host assigned devices requires to setup 1154 the DMA mapping on the host before guest DMA starts. 1155 1156 ``device-iotlb=on|off`` (default: off) 1157 This enables device-iotlb capability for the emulated VT-d device. So 1158 far virtio/vhost should be the only real user for this parameter, 1159 paired with ats=on configured for the device. 1160 1161 ``aw-bits=39|48`` (default: 39) 1162 This decides the address width of IOVA address space. The address 1163 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for 1164 4-level IOMMU page tables. 1165 1166 Please also refer to the wiki page for general scenarios of VT-d 1167 emulation in QEMU: https://wiki.qemu.org/Features/VT-d. 1168 1169ERST 1170 1171DEF("name", HAS_ARG, QEMU_OPTION_name, 1172 "-name string1[,process=string2][,debug-threads=on|off]\n" 1173 " set the name of the guest\n" 1174 " string1 sets the window title and string2 the process name\n" 1175 " When debug-threads is enabled, individual threads are given a separate name\n" 1176 " NOTE: The thread names are for debugging and not a stable API.\n", 1177 QEMU_ARCH_ALL) 1178SRST 1179``-name name`` 1180 Sets the name of the guest. This name will be displayed in the SDL 1181 window caption. The name will also be used for the VNC server. Also 1182 optionally set the top visible process name in Linux. Naming of 1183 individual threads can also be enabled on Linux to aid debugging. 1184ERST 1185 1186DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 1187 "-uuid %08x-%04x-%04x-%04x-%012x\n" 1188 " specify machine UUID\n", QEMU_ARCH_ALL) 1189SRST 1190``-uuid uuid`` 1191 Set system UUID. 1192ERST 1193 1194DEFHEADING() 1195 1196DEFHEADING(Block device options:) 1197 1198SRST 1199The QEMU block device handling options have a long history and 1200have gone through several iterations as the feature set and complexity 1201of the block layer have grown. Many online guides to QEMU often 1202reference older and deprecated options, which can lead to confusion. 1203 1204The most explicit way to describe disks is to use a combination of 1205``-device`` to specify the hardware device and ``-blockdev`` to 1206describe the backend. The device defines what the guest sees and the 1207backend describes how QEMU handles the data. It is the only guaranteed 1208stable interface for describing block devices and as such is 1209recommended for management tools and scripting. 1210 1211The ``-drive`` option combines the device and backend into a single 1212command line option which is a more human friendly. There is however no 1213interface stability guarantee although some older board models still 1214need updating to work with the modern blockdev forms. 1215 1216Older options like ``-hda`` are essentially macros which expand into 1217``-drive`` options for various drive interfaces. The original forms 1218bake in a lot of assumptions from the days when QEMU was emulating a 1219legacy PC, they are not recommended for modern configurations. 1220 1221ERST 1222 1223DEF("fda", HAS_ARG, QEMU_OPTION_fda, 1224 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 1225DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 1226SRST 1227``-fda file`` 1228 \ 1229``-fdb file`` 1230 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in 1231 the System Emulation Users Guide). 1232ERST 1233 1234DEF("hda", HAS_ARG, QEMU_OPTION_hda, 1235 "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL) 1236DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 1237DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 1238 "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL) 1239DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 1240SRST 1241``-hda file`` 1242 \ 1243``-hdb file`` 1244 \ 1245``-hdc file`` 1246 \ 1247``-hdd file`` 1248 Use file as hard disk 0, 1, 2 or 3 image on the default bus of the 1249 emulated machine (this is for example the IDE bus on most x86 machines, 1250 but it can also be SCSI, virtio or something else on other target 1251 architectures). See also the :ref:`disk images` chapter in the System 1252 Emulation Users Guide. 1253ERST 1254 1255DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 1256 "-cdrom file use 'file' as CD-ROM image\n", 1257 QEMU_ARCH_ALL) 1258SRST 1259``-cdrom file`` 1260 Use file as CD-ROM image on the default bus of the emulated machine 1261 (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom`` 1262 at the same time there). On systems that support it, you can use the 1263 host CD-ROM by using ``/dev/cdrom`` as filename. 1264ERST 1265 1266DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 1267 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 1268 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 1269 " [,read-only=on|off][,auto-read-only=on|off]\n" 1270 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 1271 " [,driver specific parameters...]\n" 1272 " configure a block backend\n", QEMU_ARCH_ALL) 1273SRST 1274``-blockdev option[,option[,option[,...]]]`` 1275 Define a new block driver node. Some of the options apply to all 1276 block drivers, other options are only accepted for a specific block 1277 driver. See below for a list of generic options and options for the 1278 most common block drivers. 1279 1280 Options that expect a reference to another node (e.g. ``file``) can 1281 be given in two ways. Either you specify the node name of an already 1282 existing node (file=node-name), or you define a new node inline, 1283 adding options for the referenced node after a dot 1284 (file.filename=path,file.aio=native). 1285 1286 A block driver node created with ``-blockdev`` can be used for a 1287 guest device by specifying its node name for the ``drive`` property 1288 in a ``-device`` argument that defines a block device. 1289 1290 ``Valid options for any block driver node:`` 1291 ``driver`` 1292 Specifies the block driver to use for the given node. 1293 1294 ``node-name`` 1295 This defines the name of the block driver node by which it 1296 will be referenced later. The name must be unique, i.e. it 1297 must not match the name of a different block driver node, or 1298 (if you use ``-drive`` as well) the ID of a drive. 1299 1300 If no node name is specified, it is automatically generated. 1301 The generated node name is not intended to be predictable 1302 and changes between QEMU invocations. For the top level, an 1303 explicit node name must be specified. 1304 1305 ``read-only`` 1306 Open the node read-only. Guest write attempts will fail. 1307 1308 Note that some block drivers support only read-only access, 1309 either generally or in certain configurations. In this case, 1310 the default value ``read-only=off`` does not work and the 1311 option must be specified explicitly. 1312 1313 ``auto-read-only`` 1314 If ``auto-read-only=on`` is set, QEMU may fall back to 1315 read-only usage even when ``read-only=off`` is requested, or 1316 even switch between modes as needed, e.g. depending on 1317 whether the image file is writable or whether a writing user 1318 is attached to the node. 1319 1320 ``force-share`` 1321 Override the image locking system of QEMU by forcing the 1322 node to utilize weaker shared access for permissions where 1323 it would normally request exclusive access. When there is 1324 the potential for multiple instances to have the same file 1325 open (whether this invocation of QEMU is the first or the 1326 second instance), both instances must permit shared access 1327 for the second instance to succeed at opening the file. 1328 1329 Enabling ``force-share=on`` requires ``read-only=on``. 1330 1331 ``cache.direct`` 1332 The host page cache can be avoided with ``cache.direct=on``. 1333 This will attempt to do disk IO directly to the guest's 1334 memory. QEMU may still perform an internal copy of the data. 1335 1336 ``cache.no-flush`` 1337 In case you don't care about data integrity over host 1338 failures, you can use ``cache.no-flush=on``. This option 1339 tells QEMU that it never needs to write any data to the disk 1340 but can instead keep things in cache. If anything goes 1341 wrong, like your host losing power, the disk storage getting 1342 disconnected accidentally, etc. your image will most 1343 probably be rendered unusable. 1344 1345 ``discard=discard`` 1346 discard is one of "ignore" (or "off") or "unmap" (or "on") 1347 and controls whether ``discard`` (also known as ``trim`` or 1348 ``unmap``) requests are ignored or passed to the filesystem. 1349 Some machine types may not support discard requests. 1350 1351 ``detect-zeroes=detect-zeroes`` 1352 detect-zeroes is "off", "on" or "unmap" and enables the 1353 automatic conversion of plain zero writes by the OS to 1354 driver specific optimized zero write commands. You may even 1355 choose "unmap" if discard is set to "unmap" to allow a zero 1356 write to be converted to an ``unmap`` operation. 1357 1358 ``Driver-specific options for file`` 1359 This is the protocol-level block driver for accessing regular 1360 files. 1361 1362 ``filename`` 1363 The path to the image file in the local filesystem 1364 1365 ``aio`` 1366 Specifies the AIO backend (threads/native/io_uring, 1367 default: threads) 1368 1369 ``locking`` 1370 Specifies whether the image file is protected with Linux OFD 1371 / POSIX locks. The default is to use the Linux Open File 1372 Descriptor API if available, otherwise no lock is applied. 1373 (auto/on/off, default: auto) 1374 1375 Example: 1376 1377 :: 1378 1379 -blockdev driver=file,node-name=disk,filename=disk.img 1380 1381 ``Driver-specific options for raw`` 1382 This is the image format block driver for raw images. It is 1383 usually stacked on top of a protocol level block driver such as 1384 ``file``. 1385 1386 ``file`` 1387 Reference to or definition of the data source block driver 1388 node (e.g. a ``file`` driver node) 1389 1390 Example 1: 1391 1392 :: 1393 1394 -blockdev driver=file,node-name=disk_file,filename=disk.img 1395 -blockdev driver=raw,node-name=disk,file=disk_file 1396 1397 Example 2: 1398 1399 :: 1400 1401 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 1402 1403 ``Driver-specific options for qcow2`` 1404 This is the image format block driver for qcow2 images. It is 1405 usually stacked on top of a protocol level block driver such as 1406 ``file``. 1407 1408 ``file`` 1409 Reference to or definition of the data source block driver 1410 node (e.g. a ``file`` driver node) 1411 1412 ``backing`` 1413 Reference to or definition of the backing file block device 1414 (default is taken from the image file). It is allowed to 1415 pass ``null`` here in order to disable the default backing 1416 file. 1417 1418 ``lazy-refcounts`` 1419 Whether to enable the lazy refcounts feature (on/off; 1420 default is taken from the image file) 1421 1422 ``cache-size`` 1423 The maximum total size of the L2 table and refcount block 1424 caches in bytes (default: the sum of l2-cache-size and 1425 refcount-cache-size) 1426 1427 ``l2-cache-size`` 1428 The maximum size of the L2 table cache in bytes (default: if 1429 cache-size is not specified - 32M on Linux platforms, and 8M 1430 on non-Linux platforms; otherwise, as large as possible 1431 within the cache-size, while permitting the requested or the 1432 minimal refcount cache size) 1433 1434 ``refcount-cache-size`` 1435 The maximum size of the refcount block cache in bytes 1436 (default: 4 times the cluster size; or if cache-size is 1437 specified, the part of it which is not used for the L2 1438 cache) 1439 1440 ``cache-clean-interval`` 1441 Clean unused entries in the L2 and refcount caches. The 1442 interval is in seconds. The default value is 600 on 1443 supporting platforms, and 0 on other platforms. Setting it 1444 to 0 disables this feature. 1445 1446 ``pass-discard-request`` 1447 Whether discard requests to the qcow2 device should be 1448 forwarded to the data source (on/off; default: on if 1449 discard=unmap is specified, off otherwise) 1450 1451 ``pass-discard-snapshot`` 1452 Whether discard requests for the data source should be 1453 issued when a snapshot operation (e.g. deleting a snapshot) 1454 frees clusters in the qcow2 file (on/off; default: on) 1455 1456 ``pass-discard-other`` 1457 Whether discard requests for the data source should be 1458 issued on other occasions where a cluster gets freed 1459 (on/off; default: off) 1460 1461 ``discard-no-unref`` 1462 When enabled, data clusters will remain preallocated when they are 1463 no longer used, e.g. because they are discarded or converted to 1464 zero clusters. As usual, whether the old data is discarded or kept 1465 on the protocol level (i.e. in the image file) depends on the 1466 setting of the pass-discard-request option. Keeping the clusters 1467 preallocated prevents qcow2 fragmentation that would otherwise be 1468 caused by freeing and re-allocating them later. Besides potential 1469 performance degradation, such fragmentation can lead to increased 1470 allocation of clusters past the end of the image file, 1471 resulting in image files whose file length can grow much larger 1472 than their guest disk size would suggest. 1473 If image file length is of concern (e.g. when storing qcow2 1474 images directly on block devices), you should consider enabling 1475 this option. 1476 1477 ``overlap-check`` 1478 Which overlap checks to perform for writes to the image 1479 (none/constant/cached/all; default: cached). For details or 1480 finer granularity control refer to the QAPI documentation of 1481 ``blockdev-add``. 1482 1483 Example 1: 1484 1485 :: 1486 1487 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1488 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1489 1490 Example 2: 1491 1492 :: 1493 1494 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1495 1496 ``Driver-specific options for other drivers`` 1497 Please refer to the QAPI documentation of the ``blockdev-add`` 1498 QMP command. 1499ERST 1500 1501DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1502 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1503 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1504 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1505 " [,werror=ignore|stop|report|enospc][,id=name]\n" 1506 " [,aio=threads|native|io_uring]\n" 1507 " [,readonly=on|off][,copy-on-read=on|off]\n" 1508 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1509 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1510 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1511 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1512 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1513 " [[,iops_size=is]]\n" 1514 " [[,group=g]]\n" 1515 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1516SRST 1517``-drive option[,option[,option[,...]]]`` 1518 Define a new drive. This includes creating a block driver node (the 1519 backend) as well as a guest device, and is mostly a shortcut for 1520 defining the corresponding ``-blockdev`` and ``-device`` options. 1521 1522 ``-drive`` accepts all options that are accepted by ``-blockdev``. 1523 In addition, it knows the following options: 1524 1525 ``file=file`` 1526 This option defines which disk image (see the :ref:`disk images` 1527 chapter in the System Emulation Users Guide) to use with this drive. 1528 If the filename contains comma, you must double it (for instance, 1529 "file=my,,file" to use file "my,file"). 1530 1531 Special files such as iSCSI devices can be specified using 1532 protocol specific URLs. See the section for "Device URL Syntax" 1533 for more information. 1534 1535 ``if=interface`` 1536 This option defines on which type on interface the drive is 1537 connected. Available types are: ide, scsi, sd, mtd, floppy, 1538 pflash, virtio, none. 1539 1540 ``bus=bus,unit=unit`` 1541 These options define where is connected the drive by defining 1542 the bus number and the unit id. 1543 1544 ``index=index`` 1545 This option defines where the drive is connected by using an 1546 index in the list of available connectors of a given interface 1547 type. 1548 1549 ``media=media`` 1550 This option defines the type of the media: disk or cdrom. 1551 1552 ``snapshot=snapshot`` 1553 snapshot is "on" or "off" and controls snapshot mode for the 1554 given drive (see ``-snapshot``). 1555 1556 ``cache=cache`` 1557 cache is "none", "writeback", "unsafe", "directsync" or 1558 "writethrough" and controls how the host cache is used to access 1559 block data. This is a shortcut that sets the ``cache.direct`` 1560 and ``cache.no-flush`` options (as in ``-blockdev``), and 1561 additionally ``cache.writeback``, which provides a default for 1562 the ``write-cache`` option of block guest devices (as in 1563 ``-device``). The modes correspond to the following settings: 1564 1565 ============= =============== ============ ============== 1566 \ cache.writeback cache.direct cache.no-flush 1567 ============= =============== ============ ============== 1568 writeback on off off 1569 none on on off 1570 writethrough off off off 1571 directsync off on off 1572 unsafe on off on 1573 ============= =============== ============ ============== 1574 1575 The default mode is ``cache=writeback``. 1576 1577 ``aio=aio`` 1578 aio is "threads", "native", or "io_uring" and selects between pthread 1579 based disk I/O, native Linux AIO, or Linux io_uring API. 1580 1581 ``format=format`` 1582 Specify which disk format will be used rather than detecting the 1583 format. Can be used to specify format=raw to avoid interpreting 1584 an untrusted format header. 1585 1586 ``werror=action,rerror=action`` 1587 Specify which action to take on write and read errors. Valid 1588 actions are: "ignore" (ignore the error and try to continue), 1589 "stop" (pause QEMU), "report" (report the error to the guest), 1590 "enospc" (pause QEMU only if the host disk is full; report the 1591 error to the guest otherwise). The default setting is 1592 ``werror=enospc`` and ``rerror=report``. 1593 1594 ``copy-on-read=copy-on-read`` 1595 copy-on-read is "on" or "off" and enables whether to copy read 1596 backing file sectors into the image file. 1597 1598 ``bps=b,bps_rd=r,bps_wr=w`` 1599 Specify bandwidth throttling limits in bytes per second, either 1600 for all request types or for reads or writes only. Small values 1601 can lead to timeouts or hangs inside the guest. A safe minimum 1602 for disks is 2 MB/s. 1603 1604 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm`` 1605 Specify bursts in bytes per second, either for all request types 1606 or for reads or writes only. Bursts allow the guest I/O to spike 1607 above the limit temporarily. 1608 1609 ``iops=i,iops_rd=r,iops_wr=w`` 1610 Specify request rate limits in requests per second, either for 1611 all request types or for reads or writes only. 1612 1613 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm`` 1614 Specify bursts in requests per second, either for all request 1615 types or for reads or writes only. Bursts allow the guest I/O to 1616 spike above the limit temporarily. 1617 1618 ``iops_size=is`` 1619 Let every is bytes of a request count as a new request for iops 1620 throttling purposes. Use this option to prevent guests from 1621 circumventing iops limits by sending fewer but larger requests. 1622 1623 ``group=g`` 1624 Join a throttling quota group with given name g. All drives that 1625 are members of the same group are accounted for together. Use 1626 this option to prevent guests from circumventing throttling 1627 limits by using many small disks instead of a single larger 1628 disk. 1629 1630 By default, the ``cache.writeback=on`` mode is used. It will report 1631 data writes as completed as soon as the data is present in the host 1632 page cache. This is safe as long as your guest OS makes sure to 1633 correctly flush disk caches where needed. If your guest OS does not 1634 handle volatile disk write caches correctly and your host crashes or 1635 loses power, then the guest may experience data corruption. 1636 1637 For such guests, you should consider using ``cache.writeback=off``. 1638 This means that the host page cache will be used to read and write 1639 data, but write notification will be sent to the guest only after 1640 QEMU has made sure to flush each write to the disk. Be aware that 1641 this has a major impact on performance. 1642 1643 When using the ``-snapshot`` option, unsafe caching is always used. 1644 1645 Copy-on-read avoids accessing the same backing file sectors 1646 repeatedly and is useful when the backing file is over a slow 1647 network. By default copy-on-read is off. 1648 1649 Instead of ``-cdrom`` you can use: 1650 1651 .. parsed-literal:: 1652 1653 |qemu_system| -drive file=file,index=2,media=cdrom 1654 1655 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use: 1656 1657 .. parsed-literal:: 1658 1659 |qemu_system| -drive file=file,index=0,media=disk 1660 |qemu_system| -drive file=file,index=1,media=disk 1661 |qemu_system| -drive file=file,index=2,media=disk 1662 |qemu_system| -drive file=file,index=3,media=disk 1663 1664 You can open an image using pre-opened file descriptors from an fd 1665 set: 1666 1667 .. parsed-literal:: 1668 1669 |qemu_system| \\ 1670 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\ 1671 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\ 1672 -drive file=/dev/fdset/2,index=0,media=disk 1673 1674 You can connect a CDROM to the slave of ide0: 1675 1676 .. parsed-literal:: 1677 1678 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom 1679 1680 If you don't specify the "file=" argument, you define an empty 1681 drive: 1682 1683 .. parsed-literal:: 1684 1685 |qemu_system_x86| -drive if=ide,index=1,media=cdrom 1686 1687 Instead of ``-fda``, ``-fdb``, you can use: 1688 1689 .. parsed-literal:: 1690 1691 |qemu_system_x86| -drive file=file,index=0,if=floppy 1692 |qemu_system_x86| -drive file=file,index=1,if=floppy 1693 1694 By default, interface is "ide" and index is automatically 1695 incremented: 1696 1697 .. parsed-literal:: 1698 1699 |qemu_system_x86| -drive file=a -drive file=b 1700 1701 is interpreted like: 1702 1703 .. parsed-literal:: 1704 1705 |qemu_system_x86| -hda a -hdb b 1706ERST 1707 1708DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1709 "-mtdblock file use 'file' as on-board Flash memory image\n", 1710 QEMU_ARCH_ALL) 1711SRST 1712``-mtdblock file`` 1713 Use file as on-board Flash memory image. 1714ERST 1715 1716DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1717 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1718SRST 1719``-sd file`` 1720 Use file as SecureDigital card image. 1721ERST 1722 1723DEF("snapshot", 0, QEMU_OPTION_snapshot, 1724 "-snapshot write to temporary files instead of disk image files\n", 1725 QEMU_ARCH_ALL) 1726SRST 1727``-snapshot`` 1728 Write to temporary files instead of disk image files. In this case, 1729 the raw disk image you use is not written back. You can however 1730 force the write back by pressing C-a s (see the :ref:`disk images` 1731 chapter in the System Emulation Users Guide). 1732 1733 .. warning:: 1734 snapshot is incompatible with ``-blockdev`` (instead use qemu-img 1735 to manually create snapshot images to attach to your blockdev). 1736 If you have mixed ``-blockdev`` and ``-drive`` declarations you 1737 can use the 'snapshot' property on your drive declarations 1738 instead of this global option. 1739 1740ERST 1741 1742DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1743 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1744 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n" 1745 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1746 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1747 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1748 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1749 " [[,throttling.iops-size=is]]\n" 1750 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n" 1751 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n" 1752 "-fsdev synth,id=id\n", 1753 QEMU_ARCH_ALL) 1754 1755SRST 1756``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]`` 1757 \ 1758``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]`` 1759 \ 1760``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]`` 1761 \ 1762``-fsdev synth,id=id[,readonly=on]`` 1763 Define a new file system device. Valid options are: 1764 1765 ``local`` 1766 Accesses to the filesystem are done by QEMU. 1767 1768 ``proxy`` 1769 Accesses to the filesystem are done by virtfs-proxy-helper(1). This 1770 option is deprecated (since QEMU 8.1) and will be removed in a future 1771 version of QEMU. Use ``local`` instead. 1772 1773 ``synth`` 1774 Synthetic filesystem, only used by QTests. 1775 1776 ``id=id`` 1777 Specifies identifier for this device. 1778 1779 ``path=path`` 1780 Specifies the export path for the file system device. Files 1781 under this path will be available to the 9p client on the guest. 1782 1783 ``security_model=security_model`` 1784 Specifies the security model to be used for this export path. 1785 Supported security models are "passthrough", "mapped-xattr", 1786 "mapped-file" and "none". In "passthrough" security model, files 1787 are stored using the same credentials as they are created on the 1788 guest. This requires QEMU to run as root. In "mapped-xattr" 1789 security model, some of the file attributes like uid, gid, mode 1790 bits and link target are stored as file attributes. For 1791 "mapped-file" these attributes are stored in the hidden 1792 .virtfs\_metadata directory. Directories exported by this 1793 security model cannot interact with other unix tools. "none" 1794 security model is same as passthrough except the sever won't 1795 report failures if it fails to set file attributes like 1796 ownership. Security model is mandatory only for local fsdriver. 1797 Other fsdrivers (like proxy) don't take security model as a 1798 parameter. 1799 1800 ``writeout=writeout`` 1801 This is an optional argument. The only supported value is 1802 "immediate". This means that host page cache will be used to 1803 read and write data but write notification will be sent to the 1804 guest only when the data has been reported as written by the 1805 storage subsystem. 1806 1807 ``readonly=on`` 1808 Enables exporting 9p share as a readonly mount for guests. By 1809 default read-write access is given. 1810 1811 ``socket=socket`` 1812 Enables proxy filesystem driver to use passed socket file for 1813 communicating with virtfs-proxy-helper(1). 1814 1815 ``sock_fd=sock_fd`` 1816 Enables proxy filesystem driver to use passed socket descriptor 1817 for communicating with virtfs-proxy-helper(1). Usually a helper 1818 like libvirt will create socketpair and pass one of the fds as 1819 sock\_fd. 1820 1821 ``fmode=fmode`` 1822 Specifies the default mode for newly created files on the host. 1823 Works only with security models "mapped-xattr" and 1824 "mapped-file". 1825 1826 ``dmode=dmode`` 1827 Specifies the default mode for newly created directories on the 1828 host. Works only with security models "mapped-xattr" and 1829 "mapped-file". 1830 1831 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w`` 1832 Specify bandwidth throttling limits in bytes per second, either 1833 for all request types or for reads or writes only. 1834 1835 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm`` 1836 Specify bursts in bytes per second, either for all request types 1837 or for reads or writes only. Bursts allow the guest I/O to spike 1838 above the limit temporarily. 1839 1840 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w`` 1841 Specify request rate limits in requests per second, either for 1842 all request types or for reads or writes only. 1843 1844 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm`` 1845 Specify bursts in requests per second, either for all request 1846 types or for reads or writes only. Bursts allow the guest I/O to 1847 spike above the limit temporarily. 1848 1849 ``throttling.iops-size=is`` 1850 Let every is bytes of a request count as a new request for iops 1851 throttling purposes. 1852 1853 -fsdev option is used along with -device driver "virtio-9p-...". 1854 1855``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag`` 1856 Options for virtio-9p-... driver are: 1857 1858 ``type`` 1859 Specifies the variant to be used. Supported values are "pci", 1860 "ccw" or "device", depending on the machine type. 1861 1862 ``fsdev=id`` 1863 Specifies the id value specified along with -fsdev option. 1864 1865 ``mount_tag=mount_tag`` 1866 Specifies the tag name to be used by the guest to mount this 1867 export point. 1868ERST 1869 1870DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1871 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1872 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1873 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n" 1874 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n" 1875 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n", 1876 QEMU_ARCH_ALL) 1877 1878SRST 1879``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]`` 1880 \ 1881``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1882 \ 1883``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]`` 1884 \ 1885``-virtfs synth,mount_tag=mount_tag`` 1886 Define a new virtual filesystem device and expose it to the guest using 1887 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain 1888 directory on host is made directly accessible by guest as a pass-through 1889 file system by using the 9P network protocol for communication between 1890 host and guests, if desired even accessible, shared by several guests 1891 simultaneously. 1892 1893 Note that ``-virtfs`` is actually just a convenience shortcut for its 1894 generalized form ``-fsdev -device virtio-9p-pci``. 1895 1896 The general form of pass-through file system options are: 1897 1898 ``local`` 1899 Accesses to the filesystem are done by QEMU. 1900 1901 ``proxy`` 1902 Accesses to the filesystem are done by virtfs-proxy-helper(1). 1903 This option is deprecated (since QEMU 8.1) and will be removed in a 1904 future version of QEMU. Use ``local`` instead. 1905 1906 ``synth`` 1907 Synthetic filesystem, only used by QTests. 1908 1909 ``id=id`` 1910 Specifies identifier for the filesystem device 1911 1912 ``path=path`` 1913 Specifies the export path for the file system device. Files 1914 under this path will be available to the 9p client on the guest. 1915 1916 ``security_model=security_model`` 1917 Specifies the security model to be used for this export path. 1918 Supported security models are "passthrough", "mapped-xattr", 1919 "mapped-file" and "none". In "passthrough" security model, files 1920 are stored using the same credentials as they are created on the 1921 guest. This requires QEMU to run as root. In "mapped-xattr" 1922 security model, some of the file attributes like uid, gid, mode 1923 bits and link target are stored as file attributes. For 1924 "mapped-file" these attributes are stored in the hidden 1925 .virtfs\_metadata directory. Directories exported by this 1926 security model cannot interact with other unix tools. "none" 1927 security model is same as passthrough except the sever won't 1928 report failures if it fails to set file attributes like 1929 ownership. Security model is mandatory only for local fsdriver. 1930 Other fsdrivers (like proxy) don't take security model as a 1931 parameter. 1932 1933 ``writeout=writeout`` 1934 This is an optional argument. The only supported value is 1935 "immediate". This means that host page cache will be used to 1936 read and write data but write notification will be sent to the 1937 guest only when the data has been reported as written by the 1938 storage subsystem. 1939 1940 ``readonly=on`` 1941 Enables exporting 9p share as a readonly mount for guests. By 1942 default read-write access is given. 1943 1944 ``socket=socket`` 1945 Enables proxy filesystem driver to use passed socket file for 1946 communicating with virtfs-proxy-helper(1). Usually a helper like 1947 libvirt will create socketpair and pass one of the fds as 1948 sock\_fd. 1949 1950 ``sock_fd`` 1951 Enables proxy filesystem driver to use passed 'sock\_fd' as the 1952 socket descriptor for interfacing with virtfs-proxy-helper(1). 1953 1954 ``fmode=fmode`` 1955 Specifies the default mode for newly created files on the host. 1956 Works only with security models "mapped-xattr" and 1957 "mapped-file". 1958 1959 ``dmode=dmode`` 1960 Specifies the default mode for newly created directories on the 1961 host. Works only with security models "mapped-xattr" and 1962 "mapped-file". 1963 1964 ``mount_tag=mount_tag`` 1965 Specifies the tag name to be used by the guest to mount this 1966 export point. 1967 1968 ``multidevs=multidevs`` 1969 Specifies how to deal with multiple devices being shared with a 1970 9p export. Supported behaviours are either "remap", "forbid" or 1971 "warn". The latter is the default behaviour on which virtfs 9p 1972 expects only one device to be shared with the same export, and 1973 if more than one device is shared and accessed via the same 9p 1974 export then only a warning message is logged (once) by qemu on 1975 host side. In order to avoid file ID collisions on guest you 1976 should either create a separate virtfs export for each device to 1977 be shared with guests (recommended way) or you might use "remap" 1978 instead which allows you to share multiple devices with only one 1979 export instead, which is achieved by remapping the original 1980 inode numbers from host to guest in a way that would prevent 1981 such collisions. Remapping inodes in such use cases is required 1982 because the original device IDs from host are never passed and 1983 exposed on guest. Instead all files of an export shared with 1984 virtfs always share the same device id on guest. So two files 1985 with identical inode numbers but from actually different devices 1986 on host would otherwise cause a file ID collision and hence 1987 potential misbehaviours on guest. "forbid" on the other hand 1988 assumes like "warn" that only one device is shared by the same 1989 export, however it will not only log a warning message but also 1990 deny access to additional devices on guest. Note though that 1991 "forbid" does currently not block all possible file access 1992 operations (e.g. readdir() would still return entries from other 1993 devices). 1994ERST 1995 1996DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1997 "-iscsi [user=user][,password=password][,password-secret=secret-id]\n" 1998 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE]\n" 1999 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2000 " [,timeout=timeout]\n" 2001 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2002 2003SRST 2004``-iscsi`` 2005 Configure iSCSI session parameters. 2006ERST 2007 2008DEFHEADING() 2009 2010DEFHEADING(USB convenience options:) 2011 2012DEF("usb", 0, QEMU_OPTION_usb, 2013 "-usb enable on-board USB host controller (if not enabled by default)\n", 2014 QEMU_ARCH_ALL) 2015SRST 2016``-usb`` 2017 Enable USB emulation on machine types with an on-board USB host 2018 controller (if not enabled by default). Note that on-board USB host 2019 controllers may not support USB 3.0. In this case 2020 ``-device qemu-xhci`` can be used instead on machines with PCI. 2021ERST 2022 2023DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 2024 "-usbdevice name add the host or guest USB device 'name'\n", 2025 QEMU_ARCH_ALL) 2026SRST 2027``-usbdevice devname`` 2028 Add the USB device devname, and enable an on-board USB controller 2029 if possible and necessary (just like it can be done via 2030 ``-machine usb=on``). Note that this option is mainly intended for 2031 the user's convenience only. More fine-grained control can be 2032 achieved by selecting a USB host controller (if necessary) and the 2033 desired USB device via the ``-device`` option instead. For example, 2034 instead of using ``-usbdevice mouse`` it is possible to use 2035 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse 2036 to a USB 3.0 controller instead (at least on machines that support 2037 PCI and do not have an USB controller enabled by default yet). 2038 For more details, see the chapter about 2039 :ref:`Connecting USB devices` in the System Emulation Users Guide. 2040 Possible devices for devname are: 2041 2042 ``braille`` 2043 Braille device. This will use BrlAPI to display the braille 2044 output on a real or fake device (i.e. it also creates a 2045 corresponding ``braille`` chardev automatically beside the 2046 ``usb-braille`` USB device). 2047 2048 ``keyboard`` 2049 Standard USB keyboard. Will override the PS/2 keyboard (if present). 2050 2051 ``mouse`` 2052 Virtual Mouse. This will override the PS/2 mouse emulation when 2053 activated. 2054 2055 ``tablet`` 2056 Pointer device that uses absolute coordinates (like a 2057 touchscreen). This means QEMU is able to report the mouse 2058 position without having to grab the mouse. Also overrides the 2059 PS/2 mouse emulation when activated. 2060 2061 ``wacom-tablet`` 2062 Wacom PenPartner USB tablet. 2063 2064 2065ERST 2066 2067DEFHEADING() 2068 2069DEFHEADING(Display options:) 2070 2071DEF("display", HAS_ARG, QEMU_OPTION_display, 2072#if defined(CONFIG_SPICE) 2073 "-display spice-app[,gl=on|off]\n" 2074#endif 2075#if defined(CONFIG_SDL) 2076 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n" 2077 " [,window-close=on|off]\n" 2078#endif 2079#if defined(CONFIG_GTK) 2080 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n" 2081 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n" 2082 " [,show-menubar=on|off]\n" 2083#endif 2084#if defined(CONFIG_VNC) 2085 "-display vnc=<display>[,<optargs>]\n" 2086#endif 2087#if defined(CONFIG_CURSES) 2088 "-display curses[,charset=<encoding>]\n" 2089#endif 2090#if defined(CONFIG_COCOA) 2091 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n" 2092 " [,show-cursor=on|off][,left-command-key=on|off]\n" 2093 " [,full-screen=on|off][,zoom-to-fit=on|off]\n" 2094#endif 2095#if defined(CONFIG_OPENGL) 2096 "-display egl-headless[,rendernode=<file>]\n" 2097#endif 2098#if defined(CONFIG_DBUS_DISPLAY) 2099 "-display dbus[,addr=<dbusaddr>]\n" 2100 " [,gl=on|core|es|off][,rendernode=<file>]\n" 2101#endif 2102 "-display none\n" 2103 " select display backend type\n" 2104 " The default display is equivalent to\n " 2105#if defined(CONFIG_GTK) 2106 "\"-display gtk\"\n" 2107#elif defined(CONFIG_SDL) 2108 "\"-display sdl\"\n" 2109#elif defined(CONFIG_COCOA) 2110 "\"-display cocoa\"\n" 2111#elif defined(CONFIG_VNC) 2112 "\"-vnc localhost:0,to=99,id=default\"\n" 2113#else 2114 "\"-display none\"\n" 2115#endif 2116 , QEMU_ARCH_ALL) 2117SRST 2118``-display type`` 2119 Select type of display to use. Use ``-display help`` to list the available 2120 display types. Valid values for type are 2121 2122 ``spice-app[,gl=on|off]`` 2123 Start QEMU as a Spice server and launch the default Spice client 2124 application. The Spice server will redirect the serial consoles 2125 and QEMU monitors. (Since 4.0) 2126 2127 ``dbus`` 2128 Export the display over D-Bus interfaces. (Since 7.0) 2129 2130 The connection is registered with the "org.qemu" name (and queued when 2131 already owned). 2132 2133 ``addr=<dbusaddr>`` : D-Bus bus address to connect to. 2134 2135 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``. 2136 2137 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface 2138 will share framebuffers with DMABUF file descriptors). 2139 2140 ``sdl`` 2141 Display video output via SDL (usually in a separate graphics 2142 window; see the SDL documentation for other possibilities). 2143 Valid parameters are: 2144 2145 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling 2146 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be 2147 either ``lshift-lctrl-lalt`` or ``rctrl``. 2148 2149 ``gl=on|off|core|es`` : Use OpenGL for displaying 2150 2151 ``show-cursor=on|off`` : Force showing the mouse cursor 2152 2153 ``window-close=on|off`` : Allow to quit qemu with window close button 2154 2155 ``gtk`` 2156 Display video output in a GTK window. This interface provides 2157 drop-down menus and other UI elements to configure and control 2158 the VM during runtime. Valid parameters are: 2159 2160 ``full-screen=on|off`` : Start in fullscreen mode 2161 2162 ``gl=on|off`` : Use OpenGL for displaying 2163 2164 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover 2165 2166 ``show-tabs=on|off`` : Display the tab bar for switching between the 2167 various graphical interfaces (e.g. VGA and 2168 virtual console character devices) by default. 2169 2170 ``show-cursor=on|off`` : Force showing the mouse cursor 2171 2172 ``window-close=on|off`` : Allow to quit qemu with window close button 2173 2174 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on" 2175 2176 ``zoom-to-fit=on|off`` : Expand video output to the window size, 2177 defaults to "off" 2178 2179 ``curses[,charset=<encoding>]`` 2180 Display video output via curses. For graphics device models 2181 which support a text mode, QEMU can display this output using a 2182 curses/ncurses interface. Nothing is displayed when the graphics 2183 device is in graphical mode or if the graphics device does not 2184 support a text mode. Generally only the VGA device models 2185 support text mode. The font charset used by the guest can be 2186 specified with the ``charset`` option, for example 2187 ``charset=CP850`` for IBM CP850 encoding. The default is 2188 ``CP437``. 2189 2190 ``cocoa`` 2191 Display video output in a Cocoa window. Mac only. This interface 2192 provides drop-down menus and other UI elements to configure and 2193 control the VM during runtime. Valid parameters are: 2194 2195 ``full-grab=on|off`` : Capture all key presses, including system combos. 2196 This requires accessibility permissions, since it 2197 performs a global grab on key events. 2198 (default: off) See 2199 https://support.apple.com/en-in/guide/mac-help/mh32356/mac 2200 2201 ``swap-opt-cmd=on|off`` : Swap the Option and Command keys so that their 2202 key codes match their position on non-Mac 2203 keyboards and you can use Meta/Super and Alt 2204 where you expect them. (default: off) 2205 2206 ``show-cursor=on|off`` : Force showing the mouse cursor 2207 2208 ``left-command-key=on|off`` : Disable forwarding left command key to host 2209 2210 ``full-screen=on|off`` : Start in fullscreen mode 2211 2212 ``zoom-to-fit=on|off`` : Expand video output to the window size, 2213 defaults to "off" 2214 2215 ``egl-headless[,rendernode=<file>]`` 2216 Offload all OpenGL operations to a local DRI device. For any 2217 graphical display, this display needs to be paired with either 2218 VNC or SPICE displays. 2219 2220 ``vnc=<display>`` 2221 Start a VNC server on display <display> 2222 2223 ``none`` 2224 Do not display video output. The guest will still see an 2225 emulated graphics card, but its output will not be displayed to 2226 the QEMU user. This option differs from the -nographic option in 2227 that it only affects what is done with video output; -nographic 2228 also changes the destination of the serial and parallel port 2229 data. 2230ERST 2231 2232DEF("nographic", 0, QEMU_OPTION_nographic, 2233 "-nographic disable graphical output and redirect serial I/Os to console\n", 2234 QEMU_ARCH_ALL) 2235SRST 2236``-nographic`` 2237 Normally, if QEMU is compiled with graphical window support, it 2238 displays output such as guest graphics, guest console, and the QEMU 2239 monitor in a window. With this option, you can totally disable 2240 graphical output so that QEMU is a simple command line application. 2241 The emulated serial port is redirected on the console and muxed with 2242 the monitor (unless redirected elsewhere explicitly). Therefore, you 2243 can still use QEMU to debug a Linux kernel with a serial console. 2244 Use C-a h for help on switching between the console and monitor. 2245ERST 2246 2247#ifdef CONFIG_SPICE 2248DEF("spice", HAS_ARG, QEMU_OPTION_spice, 2249 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 2250 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 2251 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 2252 " [,x509-dh-key-file=<file>][,addr=addr]\n" 2253 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n" 2254 " [,tls-ciphers=<list>]\n" 2255 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 2256 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 2257 " [,sasl=on|off][,disable-ticketing=on|off]\n" 2258 " [,password-secret=<secret-id>]\n" 2259 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 2260 " [,jpeg-wan-compression=[auto|never|always]]\n" 2261 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 2262 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n" 2263 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n" 2264 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 2265 " [,gl=[on|off]][,rendernode=<file>]\n" 2266 " enable spice\n" 2267 " at least one of {port, tls-port} is mandatory\n", 2268 QEMU_ARCH_ALL) 2269#endif 2270SRST 2271``-spice option[,option[,...]]`` 2272 Enable the spice remote desktop protocol. Valid options are 2273 2274 ``port=<nr>`` 2275 Set the TCP port spice is listening on for plaintext channels. 2276 2277 ``addr=<addr>`` 2278 Set the IP address spice is listening on. Default is any 2279 address. 2280 2281 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off`` 2282 Force using the specified IP version. 2283 2284 ``password-secret=<secret-id>`` 2285 Set the ID of the ``secret`` object containing the password 2286 you need to authenticate. 2287 2288 ``sasl=on|off`` 2289 Require that the client use SASL to authenticate with the spice. 2290 The exact choice of authentication method used is controlled 2291 from the system / user's SASL configuration file for the 'qemu' 2292 service. This is typically found in /etc/sasl2/qemu.conf. If 2293 running QEMU as an unprivileged user, an environment variable 2294 SASL\_CONF\_PATH can be used to make it search alternate 2295 locations for the service config. While some SASL auth methods 2296 can also provide data encryption (eg GSSAPI), it is recommended 2297 that SASL always be combined with the 'tls' and 'x509' settings 2298 to enable use of SSL and server certificates. This ensures a 2299 data encryption preventing compromise of authentication 2300 credentials. 2301 2302 ``disable-ticketing=on|off`` 2303 Allow client connects without authentication. 2304 2305 ``disable-copy-paste=on|off`` 2306 Disable copy paste between the client and the guest. 2307 2308 ``disable-agent-file-xfer=on|off`` 2309 Disable spice-vdagent based file-xfer between the client and the 2310 guest. 2311 2312 ``tls-port=<nr>`` 2313 Set the TCP port spice is listening on for encrypted channels. 2314 2315 ``x509-dir=<dir>`` 2316 Set the x509 file directory. Expects same filenames as -vnc 2317 $display,x509=$dir 2318 2319 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>`` 2320 The x509 file names can also be configured individually. 2321 2322 ``tls-ciphers=<list>`` 2323 Specify which ciphers to use. 2324 2325 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]`` 2326 Force specific channel to be used with or without TLS 2327 encryption. The options can be specified multiple times to 2328 configure multiple channels. The special name "default" can be 2329 used to set the default mode. For channels which are not 2330 explicitly forced into one mode the spice client is allowed to 2331 pick tls/plaintext as he pleases. 2332 2333 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]`` 2334 Configure image compression (lossless). Default is auto\_glz. 2335 2336 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]`` 2337 Configure wan image compression (lossy for slow links). Default 2338 is auto. 2339 2340 ``streaming-video=[off|all|filter]`` 2341 Configure video stream detection. Default is off. 2342 2343 ``agent-mouse=[on|off]`` 2344 Enable/disable passing mouse events via vdagent. Default is on. 2345 2346 ``playback-compression=[on|off]`` 2347 Enable/disable audio stream compression (using celt 0.5.1). 2348 Default is on. 2349 2350 ``seamless-migration=[on|off]`` 2351 Enable/disable spice seamless migration. Default is off. 2352 2353 ``gl=[on|off]`` 2354 Enable/disable OpenGL context. Default is off. 2355 2356 ``rendernode=<file>`` 2357 DRM render node for OpenGL rendering. If not specified, it will 2358 pick the first available. (Since 2.9) 2359ERST 2360 2361DEF("portrait", 0, QEMU_OPTION_portrait, 2362 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 2363 QEMU_ARCH_ALL) 2364SRST 2365``-portrait`` 2366 Rotate graphical output 90 deg left (only PXA LCD). 2367ERST 2368 2369DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 2370 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 2371 QEMU_ARCH_ALL) 2372SRST 2373``-rotate deg`` 2374 Rotate graphical output some deg left (only PXA LCD). 2375ERST 2376 2377DEF("vga", HAS_ARG, QEMU_OPTION_vga, 2378 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 2379 " select video card type\n", QEMU_ARCH_ALL) 2380SRST 2381``-vga type`` 2382 Select type of VGA card to emulate. Valid values for type are 2383 2384 ``cirrus`` 2385 Cirrus Logic GD5446 Video card. All Windows versions starting 2386 from Windows 95 should recognize and use this graphic card. For 2387 optimal performances, use 16 bit color depth in the guest and 2388 the host OS. (This card was the default before QEMU 2.2) 2389 2390 ``std`` 2391 Standard VGA card with Bochs VBE extensions. If your guest OS 2392 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if 2393 you want to use high resolution modes (>= 1280x1024x16) then you 2394 should use this option. (This card is the default since QEMU 2395 2.2) 2396 2397 ``vmware`` 2398 VMWare SVGA-II compatible adapter. Use it if you have 2399 sufficiently recent XFree86/XOrg server or Windows guest with a 2400 driver for this card. 2401 2402 ``qxl`` 2403 QXL paravirtual graphic card. It is VGA compatible (including 2404 VESA 2.0 VBE support). Works best with qxl guest drivers 2405 installed though. Recommended choice when using the spice 2406 protocol. 2407 2408 ``tcx`` 2409 (sun4m only) Sun TCX framebuffer. This is the default 2410 framebuffer for sun4m machines and offers both 8-bit and 24-bit 2411 colour depths at a fixed resolution of 1024x768. 2412 2413 ``cg3`` 2414 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit 2415 framebuffer for sun4m machines available in both 1024x768 2416 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people 2417 wishing to run older Solaris versions. 2418 2419 ``virtio`` 2420 Virtio VGA card. 2421 2422 ``none`` 2423 Disable VGA card. 2424ERST 2425 2426DEF("full-screen", 0, QEMU_OPTION_full_screen, 2427 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 2428SRST 2429``-full-screen`` 2430 Start in full screen. 2431ERST 2432 2433DEF("g", HAS_ARG, QEMU_OPTION_g , 2434 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 2435 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 2436SRST 2437``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]`` 2438 Set the initial graphical resolution and depth (PPC, SPARC only). 2439 2440 For PPC the default is 800x600x32. 2441 2442 For SPARC with the TCX graphics device, the default is 1024x768x8 2443 with the option of 1024x768x24. For cgthree, the default is 2444 1024x768x8 with the option of 1152x900x8 for people who wish to use 2445 OBP. 2446ERST 2447 2448#ifdef CONFIG_VNC 2449DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 2450 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 2451#endif 2452SRST 2453``-vnc display[,option[,option[,...]]]`` 2454 Normally, if QEMU is compiled with graphical window support, it 2455 displays output such as guest graphics, guest console, and the QEMU 2456 monitor in a window. With this option, you can have QEMU listen on 2457 VNC display display and redirect the VGA display over the VNC 2458 session. It is very useful to enable the usb tablet device when 2459 using this option (option ``-device usb-tablet``). When using the 2460 VNC display, you must use the ``-k`` parameter to set the keyboard 2461 layout if you are not using en-us. Valid syntax for the display is 2462 2463 ``to=L`` 2464 With this option, QEMU will try next available VNC displays, 2465 until the number L, if the origianlly defined "-vnc display" is 2466 not available, e.g. port 5900+display is already used by another 2467 application. By default, to=0. 2468 2469 ``host:d`` 2470 TCP connections will only be allowed from host on display d. By 2471 convention the TCP port is 5900+d. Optionally, host can be 2472 omitted in which case the server will accept connections from 2473 any host. 2474 2475 ``unix:path`` 2476 Connections will be allowed over UNIX domain sockets where path 2477 is the location of a unix socket to listen for connections on. 2478 2479 ``none`` 2480 VNC is initialized but not started. The monitor ``change`` 2481 command can be used to later start the VNC server. 2482 2483 Following the display value there may be one or more option flags 2484 separated by commas. Valid options are 2485 2486 ``reverse=on|off`` 2487 Connect to a listening VNC client via a "reverse" connection. 2488 The client is specified by the display. For reverse network 2489 connections (host:d,``reverse``), the d argument is a TCP port 2490 number, not a display number. 2491 2492 ``websocket=on|off`` 2493 Opens an additional TCP listening port dedicated to VNC 2494 Websocket connections. If a bare websocket option is given, the 2495 Websocket port is 5700+display. An alternative port can be 2496 specified with the syntax ``websocket``\ =port. 2497 2498 If host is specified connections will only be allowed from this 2499 host. It is possible to control the websocket listen address 2500 independently, using the syntax ``websocket``\ =host:port. 2501 2502 If no TLS credentials are provided, the websocket connection 2503 runs in unencrypted mode. If TLS credentials are provided, the 2504 websocket connection requires encrypted client connections. 2505 2506 ``password=on|off`` 2507 Require that password based authentication is used for client 2508 connections. 2509 2510 The password must be set separately using the ``set_password`` 2511 command in the :ref:`QEMU monitor`. The 2512 syntax to change your password is: 2513 ``set_password <protocol> <password>`` where <protocol> could be 2514 either "vnc" or "spice". 2515 2516 If you would like to change <protocol> password expiration, you 2517 should use ``expire_password <protocol> <expiration-time>`` 2518 where expiration time could be one of the following options: 2519 now, never, +seconds or UNIX time of expiration, e.g. +60 to 2520 make password expire in 60 seconds, or 1335196800 to make 2521 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for 2522 this date and time). 2523 2524 You can also use keywords "now" or "never" for the expiration 2525 time to allow <protocol> password to expire immediately or never 2526 expire. 2527 2528 ``password-secret=<secret-id>`` 2529 Require that password based authentication is used for client 2530 connections, using the password provided by the ``secret`` 2531 object identified by ``secret-id``. 2532 2533 ``tls-creds=ID`` 2534 Provides the ID of a set of TLS credentials to use to secure the 2535 VNC server. They will apply to both the normal VNC server socket 2536 and the websocket socket (if enabled). Setting TLS credentials 2537 will cause the VNC server socket to enable the VeNCrypt auth 2538 mechanism. The credentials should have been previously created 2539 using the ``-object tls-creds`` argument. 2540 2541 ``tls-authz=ID`` 2542 Provides the ID of the QAuthZ authorization object against which 2543 the client's x509 distinguished name will validated. This object 2544 is only resolved at time of use, so can be deleted and recreated 2545 on the fly while the VNC server is active. If missing, it will 2546 default to denying access. 2547 2548 ``sasl=on|off`` 2549 Require that the client use SASL to authenticate with the VNC 2550 server. The exact choice of authentication method used is 2551 controlled from the system / user's SASL configuration file for 2552 the 'qemu' service. This is typically found in 2553 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, 2554 an environment variable SASL\_CONF\_PATH can be used to make it 2555 search alternate locations for the service config. While some 2556 SASL auth methods can also provide data encryption (eg GSSAPI), 2557 it is recommended that SASL always be combined with the 'tls' 2558 and 'x509' settings to enable use of SSL and server 2559 certificates. This ensures a data encryption preventing 2560 compromise of authentication credentials. See the 2561 :ref:`VNC security` section in the System Emulation Users Guide 2562 for details on using SASL authentication. 2563 2564 ``sasl-authz=ID`` 2565 Provides the ID of the QAuthZ authorization object against which 2566 the client's SASL username will validated. This object is only 2567 resolved at time of use, so can be deleted and recreated on the 2568 fly while the VNC server is active. If missing, it will default 2569 to denying access. 2570 2571 ``acl=on|off`` 2572 Legacy method for enabling authorization of clients against the 2573 x509 distinguished name and SASL username. It results in the 2574 creation of two ``authz-list`` objects with IDs of 2575 ``vnc.username`` and ``vnc.x509dname``. The rules for these 2576 objects must be configured with the HMP ACL commands. 2577 2578 This option is deprecated and should no longer be used. The new 2579 ``sasl-authz`` and ``tls-authz`` options are a replacement. 2580 2581 ``lossy=on|off`` 2582 Enable lossy compression methods (gradient, JPEG, ...). If this 2583 option is set, VNC client may receive lossy framebuffer updates 2584 depending on its encoding settings. Enabling this option can 2585 save a lot of bandwidth at the expense of quality. 2586 2587 ``non-adaptive=on|off`` 2588 Disable adaptive encodings. Adaptive encodings are enabled by 2589 default. An adaptive encoding will try to detect frequently 2590 updated screen regions, and send updates in these regions using 2591 a lossy encoding (like JPEG). This can be really helpful to save 2592 bandwidth when playing videos. Disabling adaptive encodings 2593 restores the original static behavior of encodings like Tight. 2594 2595 ``share=[allow-exclusive|force-shared|ignore]`` 2596 Set display sharing policy. 'allow-exclusive' allows clients to 2597 ask for exclusive access. As suggested by the rfb spec this is 2598 implemented by dropping other connections. Connecting multiple 2599 clients in parallel requires all clients asking for a shared 2600 session (vncviewer: -shared switch). This is the default. 2601 'force-shared' disables exclusive client access. Useful for 2602 shared desktop sessions, where you don't want someone forgetting 2603 specify -shared disconnect everybody else. 'ignore' completely 2604 ignores the shared flag and allows everybody connect 2605 unconditionally. Doesn't conform to the rfb spec but is 2606 traditional QEMU behavior. 2607 2608 ``key-delay-ms`` 2609 Set keyboard delay, for key down and key up events, in 2610 milliseconds. Default is 10. Keyboards are low-bandwidth 2611 devices, so this slowdown can help the device and guest to keep 2612 up and not lose events in case events are arriving in bulk. 2613 Possible causes for the latter are flaky network connections, or 2614 scripts for automated testing. 2615 2616 ``audiodev=audiodev`` 2617 Use the specified audiodev when the VNC client requests audio 2618 transmission. When not using an -audiodev argument, this option 2619 must be omitted, otherwise is must be present and specify a 2620 valid audiodev. 2621 2622 ``power-control=on|off`` 2623 Permit the remote client to issue shutdown, reboot or reset power 2624 control requests. 2625ERST 2626 2627ARCHHEADING(, QEMU_ARCH_I386) 2628 2629ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2630 2631DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2632 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2633 QEMU_ARCH_I386) 2634SRST 2635``-win2k-hack`` 2636 Use it when installing Windows 2000 to avoid a disk full bug. After 2637 Windows 2000 is installed, you no longer need this option (this 2638 option slows down the IDE transfers). 2639ERST 2640 2641DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2642 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2643 QEMU_ARCH_I386) 2644SRST 2645``-no-fd-bootchk`` 2646 Disable boot signature checking for floppy disks in BIOS. May be 2647 needed to boot from old floppy disks. 2648ERST 2649 2650DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2651 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2652SRST 2653``-no-acpi`` 2654 Disable ACPI (Advanced Configuration and Power Interface) support. 2655 Use it if your guest OS complains about ACPI problems (PC target 2656 machine only). 2657ERST 2658 2659DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2660 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2661SRST 2662``-no-hpet`` 2663 Disable HPET support. Deprecated, use '-machine hpet=off' instead. 2664ERST 2665 2666DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2667 "-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n][,asl_compiler_id=str][,asl_compiler_rev=n][,{data|file}=file1[:file2]...]\n" 2668 " ACPI table description\n", QEMU_ARCH_I386) 2669SRST 2670``-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n] [,asl_compiler_id=str][,asl_compiler_rev=n][,data=file1[:file2]...]`` 2671 Add ACPI table with specified header fields and context from 2672 specified files. For file=, take whole ACPI table from the specified 2673 files, including all ACPI headers (possible overridden by other 2674 options). For data=, only data portion of the table is used, all 2675 header information is specified in the command line. If a SLIC table 2676 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id 2677 fields will override the same in the RSDT and the FADT (a.k.a. 2678 FACP), in order to ensure the field matches required by the 2679 Microsoft SLIC spec and the ACPI spec. 2680ERST 2681 2682DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2683 "-smbios file=binary\n" 2684 " load SMBIOS entry from binary file\n" 2685 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2686 " [,uefi=on|off]\n" 2687 " specify SMBIOS type 0 fields\n" 2688 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2689 " [,uuid=uuid][,sku=str][,family=str]\n" 2690 " specify SMBIOS type 1 fields\n" 2691 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2692 " [,asset=str][,location=str]\n" 2693 " specify SMBIOS type 2 fields\n" 2694 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2695 " [,sku=str]\n" 2696 " specify SMBIOS type 3 fields\n" 2697 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2698 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n" 2699 " [,processor-id=%d]\n" 2700 " specify SMBIOS type 4 fields\n" 2701 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n" 2702 " specify SMBIOS type 8 fields\n" 2703 "-smbios type=11[,value=str][,path=filename]\n" 2704 " specify SMBIOS type 11 fields\n" 2705 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2706 " [,asset=str][,part=str][,speed=%d]\n" 2707 " specify SMBIOS type 17 fields\n" 2708 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n" 2709 " specify SMBIOS type 41 fields\n", 2710 QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH) 2711SRST 2712``-smbios file=binary`` 2713 Load SMBIOS entry from binary file. 2714 2715``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]`` 2716 Specify SMBIOS type 0 fields 2717 2718``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]`` 2719 Specify SMBIOS type 1 fields 2720 2721``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]`` 2722 Specify SMBIOS type 2 fields 2723 2724``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]`` 2725 Specify SMBIOS type 3 fields 2726 2727``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str][,processor-id=%d]`` 2728 Specify SMBIOS type 4 fields 2729 2730``-smbios type=11[,value=str][,path=filename]`` 2731 Specify SMBIOS type 11 fields 2732 2733 This argument can be repeated multiple times, and values are added in the order they are parsed. 2734 Applications intending to use OEM strings data are encouraged to use their application name as 2735 a prefix for the value string. This facilitates passing information for multiple applications 2736 concurrently. 2737 2738 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax 2739 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes. 2740 2741 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to 2742 the SMBIOS table in the order in which they appear. 2743 2744 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535 2745 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the 2746 guest. Instead it should be used as a indicator to inform the guest where to locate the real 2747 data set, for example, by specifying the serial ID of a block device. 2748 2749 An example passing three strings is 2750 2751 .. parsed-literal:: 2752 2753 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\ 2754 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\ 2755 path=/some/file/with/oemstringsdata.txt 2756 2757 In the guest OS this is visible with the ``dmidecode`` command 2758 2759 .. parsed-literal:: 2760 2761 $ dmidecode -t 11 2762 Handle 0x0E00, DMI type 11, 5 bytes 2763 OEM Strings 2764 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/ 2765 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os 2766 String 3: myapp:some extra data 2767 2768 2769``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]`` 2770 Specify SMBIOS type 17 fields 2771 2772``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]`` 2773 Specify SMBIOS type 41 fields 2774 2775 This argument can be repeated multiple times. Its main use is to allow network interfaces be created 2776 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface 2777 position on the PCI bus. 2778 2779 Here is an example of use: 2780 2781 .. parsed-literal:: 2782 2783 -netdev user,id=internet \\ 2784 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\ 2785 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev 2786 2787 In the guest OS, the device should then appear as ``eno1``: 2788 2789 ..parsed-literal:: 2790 2791 $ ip -brief l 2792 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP> 2793 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP> 2794 2795 Currently, the PCI device has to be attached to the root bus. 2796 2797ERST 2798 2799DEFHEADING() 2800 2801DEFHEADING(Network options:) 2802 2803DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2804#ifdef CONFIG_SLIRP 2805 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n" 2806 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2807 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2808 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2809 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2810#ifndef _WIN32 2811 "[,smb=dir[,smbserver=addr]]\n" 2812#endif 2813 " configure a user mode network backend with ID 'str',\n" 2814 " its DHCP server and optional services\n" 2815#endif 2816#ifdef _WIN32 2817 "-netdev tap,id=str,ifname=name\n" 2818 " configure a host TAP network backend with ID 'str'\n" 2819#else 2820 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2821 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2822 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2823 " [,poll-us=n]\n" 2824 " configure a host TAP network backend with ID 'str'\n" 2825 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2826 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2827 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2828 " to deconfigure it\n" 2829 " use '[down]script=no' to disable script execution\n" 2830 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2831 " configure it\n" 2832 " use 'fd=h' to connect to an already opened TAP interface\n" 2833 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2834 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2835 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2836 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2837 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2838 " use vhost=on to enable experimental in kernel accelerator\n" 2839 " (only has effect for virtio guests which use MSIX)\n" 2840 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2841 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2842 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2843 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2844 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n" 2845 " spent on busy polling for vhost net\n" 2846 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2847 " configure a host TAP network backend with ID 'str' that is\n" 2848 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2849 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2850#endif 2851#ifdef __linux__ 2852 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2853 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n" 2854 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n" 2855 " [,rxcookie=rxcookie][,offset=offset]\n" 2856 " configure a network backend with ID 'str' connected to\n" 2857 " an Ethernet over L2TPv3 pseudowire.\n" 2858 " Linux kernel 3.3+ as well as most routers can talk\n" 2859 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2860 " VM to a router and even VM to Host. It is a nearly-universal\n" 2861 " standard (RFC3931). Note - this implementation uses static\n" 2862 " pre-configured tunnels (same as the Linux kernel).\n" 2863 " use 'src=' to specify source address\n" 2864 " use 'dst=' to specify destination address\n" 2865 " use 'udp=on' to specify udp encapsulation\n" 2866 " use 'srcport=' to specify source udp port\n" 2867 " use 'dstport=' to specify destination udp port\n" 2868 " use 'ipv6=on' to force v6\n" 2869 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2870 " well as a weak security measure\n" 2871 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2872 " use 'txcookie=0x012345678' to specify a txcookie\n" 2873 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2874 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2875 " use 'pincounter=on' to work around broken counter handling in peer\n" 2876 " use 'offset=X' to add an extra offset between header and data\n" 2877#endif 2878 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2879 " configure a network backend to connect to another network\n" 2880 " using a socket connection\n" 2881 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2882 " configure a network backend to connect to a multicast maddr and port\n" 2883 " use 'localaddr=addr' to specify the host address to send packets from\n" 2884 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2885 " configure a network backend to connect to another network\n" 2886 " using an UDP tunnel\n" 2887 "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port[,to=maxport][,numeric=on|off][,keep-alive=on|off][,mptcp=on|off][,addr.ipv4=on|off][,addr.ipv6=on|off][,reconnect=seconds]\n" 2888 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off][,reconnect=seconds]\n" 2889 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor[,reconnect=seconds]\n" 2890 " configure a network backend to connect to another network\n" 2891 " using a socket connection in stream mode.\n" 2892 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n" 2893 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n" 2894 " configure a network backend to connect to a multicast maddr and port\n" 2895 " use ``local.host=addr`` to specify the host address to send packets from\n" 2896 "-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]\n" 2897 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n" 2898 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n" 2899 " configure a network backend to connect to another network\n" 2900 " using an UDP tunnel\n" 2901#ifdef CONFIG_VDE 2902 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2903 " configure a network backend to connect to port 'n' of a vde switch\n" 2904 " running on host and listening for incoming connections on 'socketpath'.\n" 2905 " Use group 'groupname' and mode 'octalmode' to change default\n" 2906 " ownership and permissions for communication port.\n" 2907#endif 2908#ifdef CONFIG_NETMAP 2909 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2910 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2911 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2912 " netmap device, defaults to '/dev/netmap')\n" 2913#endif 2914#ifdef CONFIG_AF_XDP 2915 "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n" 2916 " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n" 2917 " attach to the existing network interface 'name' with AF_XDP socket\n" 2918 " use 'mode=MODE' to specify an XDP program attach mode\n" 2919 " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n" 2920 " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n" 2921 " with inhibit=on,\n" 2922 " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n" 2923 " added to a socket map in XDP program. One socket per queue.\n" 2924 " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n" 2925 " use 'start-queue=m' to specify the first queue that should be used\n" 2926#endif 2927#ifdef CONFIG_POSIX 2928 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2929 " configure a vhost-user network, backed by a chardev 'dev'\n" 2930#endif 2931#ifdef __linux__ 2932 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n" 2933 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n" 2934 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n" 2935 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n" 2936#endif 2937#ifdef CONFIG_VMNET 2938 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n" 2939 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2940 " configure a vmnet network backend in host mode with ID 'str',\n" 2941 " isolate this interface from others with 'isolated',\n" 2942 " configure the address range and choose a subnet mask,\n" 2943 " specify network UUID 'uuid' to disable DHCP and interact with\n" 2944 " vmnet-host interfaces within this isolated network\n" 2945 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n" 2946 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n" 2947 " configure a vmnet network backend in shared mode with ID 'str',\n" 2948 " configure the address range and choose a subnet mask,\n" 2949 " set IPv6 ULA prefix (of length 64) to use for internal network,\n" 2950 " isolate this interface from others with 'isolated'\n" 2951 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n" 2952 " configure a vmnet network backend in bridged mode with ID 'str',\n" 2953 " use 'ifname=name' to select a physical network interface to be bridged,\n" 2954 " isolate this interface from others with 'isolated'\n" 2955#endif 2956 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2957 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2958DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2959 "-nic [tap|bridge|" 2960#ifdef CONFIG_SLIRP 2961 "user|" 2962#endif 2963#ifdef __linux__ 2964 "l2tpv3|" 2965#endif 2966#ifdef CONFIG_VDE 2967 "vde|" 2968#endif 2969#ifdef CONFIG_NETMAP 2970 "netmap|" 2971#endif 2972#ifdef CONFIG_AF_XDP 2973 "af-xdp|" 2974#endif 2975#ifdef CONFIG_POSIX 2976 "vhost-user|" 2977#endif 2978#ifdef CONFIG_VMNET 2979 "vmnet-host|vmnet-shared|vmnet-bridged|" 2980#endif 2981 "socket][,option][,...][mac=macaddr]\n" 2982 " initialize an on-board / default host NIC (using MAC address\n" 2983 " macaddr) and connect it to the given host network backend\n" 2984 "-nic none use it alone to have zero network devices (the default is to\n" 2985 " provided a 'user' network connection)\n", 2986 QEMU_ARCH_ALL) 2987DEF("net", HAS_ARG, QEMU_OPTION_net, 2988 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2989 " configure or create an on-board (or machine default) NIC and\n" 2990 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2991 "-net [" 2992#ifdef CONFIG_SLIRP 2993 "user|" 2994#endif 2995 "tap|" 2996 "bridge|" 2997#ifdef CONFIG_VDE 2998 "vde|" 2999#endif 3000#ifdef CONFIG_NETMAP 3001 "netmap|" 3002#endif 3003#ifdef CONFIG_AF_XDP 3004 "af-xdp|" 3005#endif 3006#ifdef CONFIG_VMNET 3007 "vmnet-host|vmnet-shared|vmnet-bridged|" 3008#endif 3009 "socket][,option][,option][,...]\n" 3010 " old way to initialize a host network interface\n" 3011 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 3012SRST 3013``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]`` 3014 This option is a shortcut for configuring both the on-board 3015 (default) guest NIC hardware and the host network backend in one go. 3016 The host backend options are the same as with the corresponding 3017 ``-netdev`` options below. The guest NIC model can be set with 3018 ``model=modelname``. Use ``model=help`` to list the available device 3019 types. The hardware MAC address can be set with ``mac=macaddr``. 3020 3021 The following two example do exactly the same, to show how ``-nic`` 3022 can be used to shorten the command line length: 3023 3024 .. parsed-literal:: 3025 3026 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 3027 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 3028 3029``-nic none`` 3030 Indicate that no network devices should be configured. It is used to 3031 override the default configuration (default NIC with "user" host 3032 network backend) which is activated if no other networking options 3033 are provided. 3034 3035``-netdev user,id=id[,option][,option][,...]`` 3036 Configure user mode host network backend which requires no 3037 administrator privilege to run. Valid options are: 3038 3039 ``id=id`` 3040 Assign symbolic name for use in monitor commands. 3041 3042 ``ipv4=on|off and ipv6=on|off`` 3043 Specify that either IPv4 or IPv6 must be enabled. If neither is 3044 specified both protocols are enabled. 3045 3046 ``net=addr[/mask]`` 3047 Set IP network address the guest will see. Optionally specify 3048 the netmask, either in the form a.b.c.d or as number of valid 3049 top-most bits. Default is 10.0.2.0/24. 3050 3051 ``host=addr`` 3052 Specify the guest-visible address of the host. Default is the 3053 2nd IP in the guest network, i.e. x.x.x.2. 3054 3055 ``ipv6-net=addr[/int]`` 3056 Set IPv6 network address the guest will see (default is 3057 fec0::/64). The network prefix is given in the usual hexadecimal 3058 IPv6 address notation. The prefix size is optional, and is given 3059 as the number of valid top-most bits (default is 64). 3060 3061 ``ipv6-host=addr`` 3062 Specify the guest-visible IPv6 address of the host. Default is 3063 the 2nd IPv6 in the guest network, i.e. xxxx::2. 3064 3065 ``restrict=on|off`` 3066 If this option is enabled, the guest will be isolated, i.e. it 3067 will not be able to contact the host and no guest IP packets 3068 will be routed over the host to the outside. This option does 3069 not affect any explicitly set forwarding rules. 3070 3071 ``hostname=name`` 3072 Specifies the client hostname reported by the built-in DHCP 3073 server. 3074 3075 ``dhcpstart=addr`` 3076 Specify the first of the 16 IPs the built-in DHCP server can 3077 assign. Default is the 15th to 31st IP in the guest network, 3078 i.e. x.x.x.15 to x.x.x.31. 3079 3080 ``dns=addr`` 3081 Specify the guest-visible address of the virtual nameserver. The 3082 address must be different from the host address. Default is the 3083 3rd IP in the guest network, i.e. x.x.x.3. 3084 3085 ``ipv6-dns=addr`` 3086 Specify the guest-visible address of the IPv6 virtual 3087 nameserver. The address must be different from the host address. 3088 Default is the 3rd IP in the guest network, i.e. xxxx::3. 3089 3090 ``dnssearch=domain`` 3091 Provides an entry for the domain-search list sent by the 3092 built-in DHCP server. More than one domain suffix can be 3093 transmitted by specifying this option multiple times. If 3094 supported, this will cause the guest to automatically try to 3095 append the given domain suffix(es) in case a domain name can not 3096 be resolved. 3097 3098 Example: 3099 3100 .. parsed-literal:: 3101 3102 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 3103 3104 ``domainname=domain`` 3105 Specifies the client domain name reported by the built-in DHCP 3106 server. 3107 3108 ``tftp=dir`` 3109 When using the user mode network stack, activate a built-in TFTP 3110 server. The files in dir will be exposed as the root of a TFTP 3111 server. The TFTP client on the guest must be configured in 3112 binary mode (use the command ``bin`` of the Unix TFTP client). 3113 3114 ``tftp-server-name=name`` 3115 In BOOTP reply, broadcast name as the "TFTP server name" 3116 (RFC2132 option 66). This can be used to advise the guest to 3117 load boot files or configurations from a different server than 3118 the host address. 3119 3120 ``bootfile=file`` 3121 When using the user mode network stack, broadcast file as the 3122 BOOTP filename. In conjunction with ``tftp``, this can be used 3123 to network boot a guest from a local directory. 3124 3125 Example (using pxelinux): 3126 3127 .. parsed-literal:: 3128 3129 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\ 3130 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 3131 3132 ``smb=dir[,smbserver=addr]`` 3133 When using the user mode network stack, activate a built-in SMB 3134 server so that Windows OSes can access to the host files in 3135 ``dir`` transparently. The IP address of the SMB server can be 3136 set to addr. By default the 4th IP in the guest network is used, 3137 i.e. x.x.x.4. 3138 3139 In the guest Windows OS, the line: 3140 3141 :: 3142 3143 10.0.2.4 smbserver 3144 3145 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows 3146 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows 3147 NT/2000). 3148 3149 Then ``dir`` can be accessed in ``\\smbserver\qemu``. 3150 3151 Note that a SAMBA server must be installed on the host OS. 3152 3153 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport`` 3154 Redirect incoming TCP or UDP connections to the host port 3155 hostport to the guest IP address guestaddr on guest port 3156 guestport. If guestaddr is not specified, its value is x.x.x.15 3157 (default first address given by the built-in DHCP server). By 3158 specifying hostaddr, the rule can be bound to a specific host 3159 interface. If no connection type is set, TCP is used. This 3160 option can be given multiple times. 3161 3162 For example, to redirect host X11 connection from screen 1 to 3163 guest screen 0, use the following: 3164 3165 .. parsed-literal:: 3166 3167 # on the host 3168 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 3169 # this host xterm should open in the guest X11 server 3170 xterm -display :1 3171 3172 To redirect telnet connections from host port 5555 to telnet 3173 port on the guest, use the following: 3174 3175 .. parsed-literal:: 3176 3177 # on the host 3178 |qemu_system| -nic user,hostfwd=tcp::5555-:23 3179 telnet localhost 5555 3180 3181 Then when you use on the host ``telnet localhost 5555``, you 3182 connect to the guest telnet server. 3183 3184 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command`` 3185 Forward guest TCP connections to the IP address server on port 3186 port to the character device dev or to a program executed by 3187 cmd:command which gets spawned for each connection. This option 3188 can be given multiple times. 3189 3190 You can either use a chardev directly and have that one used 3191 throughout QEMU's lifetime, like in the following example: 3192 3193 .. parsed-literal:: 3194 3195 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 3196 # the guest accesses it 3197 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 3198 3199 Or you can execute a command on every TCP connection established 3200 by the guest, so that QEMU behaves similar to an inetd process 3201 for that virtual server: 3202 3203 .. parsed-literal:: 3204 3205 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 3206 # and connect the TCP stream to its stdin/stdout 3207 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 3208 3209``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` 3210 Configure a host TAP network backend with ID id. 3211 3212 Use the network script file to configure it and the network script 3213 dfile to deconfigure it. If name is not provided, the OS 3214 automatically provides one. The default network configure script is 3215 ``/etc/qemu-ifup`` and the default network deconfigure script is 3216 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to 3217 disable script execution. 3218 3219 If running QEMU as an unprivileged user, use the network helper 3220 to configure the TAP interface and attach it to the bridge. 3221 The default network helper executable is 3222 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3223 ``br0``. 3224 3225 ``fd``\ =h can be used to specify the handle of an already opened 3226 host TAP interface. 3227 3228 Examples: 3229 3230 .. parsed-literal:: 3231 3232 #launch a QEMU instance with the default network script 3233 |qemu_system| linux.img -nic tap 3234 3235 .. parsed-literal:: 3236 3237 #launch a QEMU instance with two NICs, each one connected 3238 #to a TAP device 3239 |qemu_system| linux.img \\ 3240 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\ 3241 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 3242 3243 .. parsed-literal:: 3244 3245 #launch a QEMU instance with the default network helper to 3246 #connect a TAP device to bridge br0 3247 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3248 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 3249 3250``-netdev bridge,id=id[,br=bridge][,helper=helper]`` 3251 Connect a host TAP network interface to a host bridge device. 3252 3253 Use the network helper helper to configure the TAP interface and 3254 attach it to the bridge. The default network helper executable is 3255 ``/path/to/qemu-bridge-helper`` and the default bridge device is 3256 ``br0``. 3257 3258 Examples: 3259 3260 .. parsed-literal:: 3261 3262 #launch a QEMU instance with the default network helper to 3263 #connect a TAP device to bridge br0 3264 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 3265 3266 .. parsed-literal:: 3267 3268 #launch a QEMU instance with the default network helper to 3269 #connect a TAP device to bridge qemubr0 3270 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 3271 3272``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]`` 3273 This host network backend can be used to connect the guest's network 3274 to another QEMU virtual machine using a TCP socket connection. If 3275 ``listen`` is specified, QEMU waits for incoming connections on port 3276 (host is optional). ``connect`` is used to connect to another QEMU 3277 instance using the ``listen`` option. ``fd``\ =h specifies an 3278 already opened TCP socket. 3279 3280 Example: 3281 3282 .. parsed-literal:: 3283 3284 # launch a first QEMU instance 3285 |qemu_system| linux.img \\ 3286 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3287 -netdev socket,id=n1,listen=:1234 3288 # connect the network of this instance to the network of the first instance 3289 |qemu_system| linux.img \\ 3290 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3291 -netdev socket,id=n2,connect=127.0.0.1:1234 3292 3293``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]`` 3294 Configure a socket host network backend to share the guest's network 3295 traffic with another QEMU virtual machines using a UDP multicast 3296 socket, effectively making a bus for every QEMU with same multicast 3297 address maddr and port. NOTES: 3298 3299 1. Several QEMU can be running on different hosts and share same bus 3300 (assuming correct multicast setup for these hosts). 3301 3302 2. mcast support is compatible with User Mode Linux (argument 3303 ``ethN=mcast``), see http://user-mode-linux.sf.net. 3304 3305 3. Use ``fd=h`` to specify an already opened UDP multicast socket. 3306 3307 Example: 3308 3309 .. parsed-literal:: 3310 3311 # launch one QEMU instance 3312 |qemu_system| linux.img \\ 3313 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3314 -netdev socket,id=n1,mcast=230.0.0.1:1234 3315 # launch another QEMU instance on same "bus" 3316 |qemu_system| linux.img \\ 3317 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\ 3318 -netdev socket,id=n2,mcast=230.0.0.1:1234 3319 # launch yet another QEMU instance on same "bus" 3320 |qemu_system| linux.img \\ 3321 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\ 3322 -netdev socket,id=n3,mcast=230.0.0.1:1234 3323 3324 Example (User Mode Linux compat.): 3325 3326 .. parsed-literal:: 3327 3328 # launch QEMU instance (note mcast address selected is UML's default) 3329 |qemu_system| linux.img \\ 3330 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3331 -netdev socket,id=n1,mcast=239.192.168.1:1102 3332 # launch UML 3333 /path/to/linux ubd0=/path/to/root_fs eth0=mcast 3334 3335 Example (send packets from host's 1.2.3.4): 3336 3337 .. parsed-literal:: 3338 3339 |qemu_system| linux.img \\ 3340 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\ 3341 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 3342 3343``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on|off][,udp=on|off][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]`` 3344 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931) 3345 is a popular protocol to transport Ethernet (and other Layer 2) data 3346 frames between two systems. It is present in routers, firewalls and 3347 the Linux kernel (from version 3.3 onwards). 3348 3349 This transport allows a VM to communicate to another VM, router or 3350 firewall directly. 3351 3352 ``src=srcaddr`` 3353 source address (mandatory) 3354 3355 ``dst=dstaddr`` 3356 destination address (mandatory) 3357 3358 ``udp`` 3359 select udp encapsulation (default is ip). 3360 3361 ``srcport=srcport`` 3362 source udp port. 3363 3364 ``dstport=dstport`` 3365 destination udp port. 3366 3367 ``ipv6`` 3368 force v6, otherwise defaults to v4. 3369 3370 ``rxcookie=rxcookie``; \ ``txcookie=txcookie`` 3371 Cookies are a weak form of security in the l2tpv3 specification. 3372 Their function is mostly to prevent misconfiguration. By default 3373 they are 32 bit. 3374 3375 ``cookie64`` 3376 Set cookie size to 64 bit instead of the default 32 3377 3378 ``counter=off`` 3379 Force a 'cut-down' L2TPv3 with no counter as in 3380 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 3381 3382 ``pincounter=on`` 3383 Work around broken counter handling in peer. This may also help 3384 on networks which have packet reorder. 3385 3386 ``offset=offset`` 3387 Add an extra offset between header and data 3388 3389 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to 3390 the bridge br-lan on the remote Linux host 1.2.3.4: 3391 3392 .. parsed-literal:: 3393 3394 # Setup tunnel on linux host using raw ip as encapsulation 3395 # on 1.2.3.4 3396 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\ 3397 encap udp udp_sport 16384 udp_dport 16384 3398 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\ 3399 0xFFFFFFFF peer_session_id 0xFFFFFFFF 3400 ifconfig vmtunnel0 mtu 1500 3401 ifconfig vmtunnel0 up 3402 brctl addif br-lan vmtunnel0 3403 3404 3405 # on 4.3.2.1 3406 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 3407 3408 |qemu_system| linux.img -device e1000,netdev=n1 \\ 3409 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 3410 3411``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]`` 3412 Configure VDE backend to connect to PORT n of a vde switch running 3413 on host and listening for incoming connections on socketpath. Use 3414 GROUP groupname and MODE octalmode to change default ownership and 3415 permissions for communication port. This option is only available if 3416 QEMU has been compiled with vde support enabled. 3417 3418 Example: 3419 3420 .. parsed-literal:: 3421 3422 # launch vde switch 3423 vde_switch -F -sock /tmp/myswitch 3424 # launch QEMU instance 3425 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch 3426 3427``-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off][,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]`` 3428 Configure AF_XDP backend to connect to a network interface 'name' 3429 using AF_XDP socket. A specific program attach mode for a default 3430 XDP program can be forced with 'mode', defaults to best-effort, 3431 where the likely most performant mode will be in use. Number of queues 3432 'n' should generally match the number or queues in the interface, 3433 defaults to 1. Traffic arriving on non-configured device queues will 3434 not be delivered to the network backend. 3435 3436 .. parsed-literal:: 3437 3438 # set number of queues to 4 3439 ethtool -L eth0 combined 4 3440 # launch QEMU instance 3441 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3442 -netdev af-xdp,id=n1,ifname=eth0,queues=4 3443 3444 'start-queue' option can be specified if a particular range of queues 3445 [m, m + n] should be in use. For example, this is may be necessary in 3446 order to use certain NICs in native mode. Kernel allows the driver to 3447 create a separate set of XDP queues on top of regular ones, and only 3448 these queues can be used for AF_XDP sockets. NICs that work this way 3449 may also require an additional traffic redirection with ethtool to these 3450 special queues. 3451 3452 .. parsed-literal:: 3453 3454 # set number of queues to 1 3455 ethtool -L eth0 combined 1 3456 # redirect all the traffic to the second queue (id: 1) 3457 # note: drivers may require non-empty key/mask pair. 3458 ethtool -N eth0 flow-type ether \\ 3459 dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1 3460 ethtool -N eth0 flow-type ether \\ 3461 dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1 3462 # launch QEMU instance 3463 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3464 -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1 3465 3466 XDP program can also be loaded externally. In this case 'inhibit' option 3467 should be set to 'on' and 'sock-fds' provided with file descriptors for 3468 already open but not bound XDP sockets already added to a socket map for 3469 corresponding queues. One socket per queue. 3470 3471 .. parsed-literal:: 3472 3473 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\ 3474 -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17 3475 3476``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` 3477 Establish a vhost-user netdev, backed by a chardev id. The chardev 3478 should be a unix domain socket backed one. The vhost-user uses a 3479 specifically defined protocol to pass vhost ioctl replacement 3480 messages to an application on the other end of the socket. On 3481 non-MSIX guests, the feature can be forced with vhostforce. Use 3482 'queues=n' to specify the number of queues to be created for 3483 multiqueue vhost-user. 3484 3485 Example: 3486 3487 :: 3488 3489 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 3490 -numa node,memdev=mem \ 3491 -chardev socket,id=chr0,path=/path/to/socket \ 3492 -netdev type=vhost-user,id=net0,chardev=chr0 \ 3493 -device virtio-net-pci,netdev=net0 3494 3495``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]`` 3496 Establish a vhost-vdpa netdev. 3497 3498 vDPA device is a device that uses a datapath which complies with 3499 the virtio specifications with a vendor specific control path. 3500 vDPA devices can be both physically located on the hardware or 3501 emulated by software. 3502 3503``-netdev hubport,id=id,hubid=hubid[,netdev=nd]`` 3504 Create a hub port on the emulated hub with ID hubid. 3505 3506 The hubport netdev lets you connect a NIC to a QEMU emulated hub 3507 instead of a single netdev. Alternatively, you can also connect the 3508 hubport to another netdev with ID nd by using the ``netdev=nd`` 3509 option. 3510 3511``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]`` 3512 Legacy option to configure or create an on-board (or machine 3513 default) Network Interface Card(NIC) and connect it either to the 3514 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd. 3515 If model is omitted, then the default NIC model associated with the 3516 machine type is used. Note that the default NIC model may change in 3517 future QEMU releases, so it is highly recommended to always specify 3518 a model. Optionally, the MAC address can be changed to mac, the 3519 device address set to addr (PCI cards only), and a name can be 3520 assigned for use in monitor commands. Optionally, for PCI cards, you 3521 can specify the number v of MSI-X vectors that the card should have; 3522 this option currently only affects virtio cards; set v = 0 to 3523 disable MSI-X. If no ``-net`` option is specified, a single NIC is 3524 created. QEMU can emulate several different models of network card. 3525 Use ``-net nic,model=help`` for a list of available devices for your 3526 target. 3527 3528``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]`` 3529 Configure a host network backend (with the options corresponding to 3530 the same ``-netdev`` option) and connect it to the emulated hub 0 3531 (the default hub). Use name to specify the name of the hub port. 3532ERST 3533 3534DEFHEADING() 3535 3536DEFHEADING(Character device options:) 3537 3538DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 3539 "-chardev help\n" 3540 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3541 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" 3542 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" 3543 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 3544 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" 3545 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" 3546 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 3547 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" 3548 " [,logfile=PATH][,logappend=on|off]\n" 3549 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3550 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 3551 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3552 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 3553 "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3554 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3555#ifdef _WIN32 3556 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3557 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3558#else 3559 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3560 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 3561#endif 3562#ifdef CONFIG_BRLAPI 3563 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3564#endif 3565#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 3566 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 3567 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3568#endif 3569#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 3570 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 3571#endif 3572#if defined(CONFIG_SPICE) 3573 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3574 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 3575#endif 3576 , QEMU_ARCH_ALL 3577) 3578 3579SRST 3580The general form of a character device option is: 3581 3582``-chardev backend,id=id[,mux=on|off][,options]`` 3583 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, 3584 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, 3585 ``pty``, ``stdio``, ``braille``, ``parallel``, 3586 ``spicevmc``, ``spiceport``. The specific backend will determine the 3587 applicable options. 3588 3589 Use ``-chardev help`` to print all available chardev backend types. 3590 3591 All devices must have an id, which can be any string up to 127 3592 characters long. It is used to uniquely identify this device in 3593 other command line directives. 3594 3595 A character device may be used in multiplexing mode by multiple 3596 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is 3597 a "1:N" device, and here the "1" end is your specified chardev 3598 backend, and the "N" end is the various parts of QEMU that can talk 3599 to a chardev. If you create a chardev with ``id=myid`` and 3600 ``mux=on``, QEMU will create a multiplexer with your specified ID, 3601 and you can then configure multiple front ends to use that chardev 3602 ID for their input/output. Up to four different front ends can be 3603 connected to a single multiplexed chardev. (Without multiplexing 3604 enabled, a chardev can only be used by a single front end.) For 3605 instance you could use this to allow a single stdio chardev to be 3606 used by two serial ports and the QEMU monitor: 3607 3608 :: 3609 3610 -chardev stdio,mux=on,id=char0 \ 3611 -mon chardev=char0,mode=readline \ 3612 -serial chardev:char0 \ 3613 -serial chardev:char0 3614 3615 You can have more than one multiplexer in a system configuration; 3616 for instance you could have a TCP port multiplexed between UART 0 3617 and UART 1, and stdio multiplexed between the QEMU monitor and a 3618 parallel port: 3619 3620 :: 3621 3622 -chardev stdio,mux=on,id=char0 \ 3623 -mon chardev=char0,mode=readline \ 3624 -parallel chardev:char0 \ 3625 -chardev tcp,...,mux=on,id=char1 \ 3626 -serial chardev:char1 \ 3627 -serial chardev:char1 3628 3629 When you're using a multiplexed character device, some escape 3630 sequences are interpreted in the input. See the chapter about 3631 :ref:`keys in the character backend multiplexer` in the 3632 System Emulation Users Guide for more details. 3633 3634 Note that some other command line options may implicitly create 3635 multiplexed character backends; for instance ``-serial mon:stdio`` 3636 creates a multiplexed stdio backend connected to the serial port and 3637 the QEMU monitor, and ``-nographic`` also multiplexes the console 3638 and the monitor to stdio. 3639 3640 There is currently no support for multiplexing in the other 3641 direction (where a single QEMU front end takes input and output from 3642 multiple chardevs). 3643 3644 Every backend supports the ``logfile`` option, which supplies the 3645 path to a file to record all data transmitted via the backend. The 3646 ``logappend`` option controls whether the log file will be truncated 3647 or appended to when opened. 3648 3649The available backends are: 3650 3651``-chardev null,id=id`` 3652 A void device. This device will not emit any data, and will drop any 3653 data it receives. The null backend does not take any options. 3654 3655``-chardev socket,id=id[,TCP options or unix options][,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,tls-creds=id][,tls-authz=id]`` 3656 Create a two-way stream socket, which can be either a TCP or a unix 3657 socket. A unix socket will be created if ``path`` is specified. 3658 Behaviour is undefined if TCP options are specified for a unix 3659 socket. 3660 3661 ``server=on|off`` specifies that the socket shall be a listening socket. 3662 3663 ``wait=on|off`` specifies that QEMU should not block waiting for a client 3664 to connect to a listening socket. 3665 3666 ``telnet=on|off`` specifies that traffic on the socket should interpret 3667 telnet escape sequences. 3668 3669 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for 3670 communication. 3671 3672 ``reconnect`` sets the timeout for reconnecting on non-server 3673 sockets when the remote end goes away. qemu will delay this many 3674 seconds and then attempt to reconnect. Zero disables reconnecting, 3675 and is the default. 3676 3677 ``tls-creds`` requests enablement of the TLS protocol for 3678 encryption, and specifies the id of the TLS credentials to use for 3679 the handshake. The credentials must be previously created with the 3680 ``-object tls-creds`` argument. 3681 3682 ``tls-auth`` provides the ID of the QAuthZ authorization object 3683 against which the client's x509 distinguished name will be 3684 validated. This object is only resolved at time of use, so can be 3685 deleted and recreated on the fly while the chardev server is active. 3686 If missing, it will default to denying access. 3687 3688 TCP and unix socket options are given below: 3689 3690 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` 3691 ``host`` for a listening socket specifies the local address to 3692 be bound. For a connecting socket species the remote host to 3693 connect to. ``host`` is optional for listening sockets. If not 3694 specified it defaults to ``0.0.0.0``. 3695 3696 ``port`` for a listening socket specifies the local port to be 3697 bound. For a connecting socket specifies the port on the remote 3698 host to connect to. ``port`` can be given as either a port 3699 number or a service name. ``port`` is required. 3700 3701 ``to`` is only relevant to listening sockets. If it is 3702 specified, and ``port`` cannot be bound, QEMU will attempt to 3703 bind to subsequent ports up to and including ``to`` until it 3704 succeeds. ``to`` must be specified as a port number. 3705 3706 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 3707 or IPv6 must be used. If neither is specified the socket may 3708 use either protocol. 3709 3710 ``nodelay=on|off`` disables the Nagle algorithm. 3711 3712 ``unix options: path=path[,abstract=on|off][,tight=on|off]`` 3713 ``path`` specifies the local path of the unix socket. ``path`` 3714 is required. 3715 ``abstract=on|off`` specifies the use of the abstract socket namespace, 3716 rather than the filesystem. Optional, defaults to false. 3717 ``tight=on|off`` sets the socket length of abstract sockets to their minimum, 3718 rather than the full sun_path length. Optional, defaults to true. 3719 3720``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]`` 3721 Sends all traffic from the guest to a remote host over UDP. 3722 3723 ``host`` specifies the remote host to connect to. If not specified 3724 it defaults to ``localhost``. 3725 3726 ``port`` specifies the port on the remote host to connect to. 3727 ``port`` is required. 3728 3729 ``localaddr`` specifies the local address to bind to. If not 3730 specified it defaults to ``0.0.0.0``. 3731 3732 ``localport`` specifies the local port to bind to. If not specified 3733 any available local port will be used. 3734 3735 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used. 3736 If neither is specified the device may use either protocol. 3737 3738``-chardev msmouse,id=id`` 3739 Forward QEMU's emulated msmouse events to the guest. ``msmouse`` 3740 does not take any options. 3741 3742``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` 3743 Connect to a QEMU text console. ``vc`` may optionally be given a 3744 specific size. 3745 3746 ``width`` and ``height`` specify the width and height respectively 3747 of the console, in pixels. 3748 3749 ``cols`` and ``rows`` specify that the console be sized to fit a 3750 text console with the given dimensions. 3751 3752``-chardev ringbuf,id=id[,size=size]`` 3753 Create a ring buffer with fixed size ``size``. size must be a power 3754 of two and defaults to ``64K``. 3755 3756``-chardev file,id=id,path=path[,input-path=input-path]`` 3757 Log all traffic received from the guest to a file. 3758 3759 ``path`` specifies the path of the file to be opened. This file will 3760 be created if it does not already exist, and overwritten if it does. 3761 ``path`` is required. 3762 3763 If ``input-path`` is specified, this is the path of a second file 3764 which will be used for input. If ``input-path`` is not specified, 3765 no input will be available from the chardev. 3766 3767 Note that ``input-path`` is not supported on Windows hosts. 3768 3769``-chardev pipe,id=id,path=path`` 3770 Create a two-way connection to the guest. The behaviour differs 3771 slightly between Windows hosts and other hosts: 3772 3773 On Windows, a single duplex pipe will be created at 3774 ``\\.pipe\path``. 3775 3776 On other hosts, 2 pipes will be created called ``path.in`` and 3777 ``path.out``. Data written to ``path.in`` will be received by the 3778 guest. Data written by the guest can be read from ``path.out``. QEMU 3779 will not create these fifos, and requires them to be present. 3780 3781 ``path`` forms part of the pipe path as described above. ``path`` is 3782 required. 3783 3784``-chardev console,id=id`` 3785 Send traffic from the guest to QEMU's standard output. ``console`` 3786 does not take any options. 3787 3788 ``console`` is only available on Windows hosts. 3789 3790``-chardev serial,id=id,path=path`` 3791 Send traffic from the guest to a serial device on the host. 3792 3793 On Unix hosts serial will actually accept any tty device, not only 3794 serial lines. 3795 3796 ``path`` specifies the name of the serial device to open. 3797 3798``-chardev pty,id=id`` 3799 Create a new pseudo-terminal on the host and connect to it. ``pty`` 3800 does not take any options. 3801 3802 ``pty`` is not available on Windows hosts. 3803 3804``-chardev stdio,id=id[,signal=on|off]`` 3805 Connect to standard input and standard output of the QEMU process. 3806 3807 ``signal`` controls if signals are enabled on the terminal, that 3808 includes exiting QEMU with the key sequence Control-c. This option 3809 is enabled by default, use ``signal=off`` to disable it. 3810 3811``-chardev braille,id=id`` 3812 Connect to a local BrlAPI server. ``braille`` does not take any 3813 options. 3814 3815``-chardev parallel,id=id,path=path`` 3816 \ 3817 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD 3818 hosts. 3819 3820 Connect to a local parallel port. 3821 3822 ``path`` specifies the path to the parallel port device. ``path`` is 3823 required. 3824 3825``-chardev spicevmc,id=id,debug=debug,name=name`` 3826 ``spicevmc`` is only available when spice support is built in. 3827 3828 ``debug`` debug level for spicevmc 3829 3830 ``name`` name of spice channel to connect to 3831 3832 Connect to a spice virtual machine channel, such as vdiport. 3833 3834``-chardev spiceport,id=id,debug=debug,name=name`` 3835 ``spiceport`` is only available when spice support is built in. 3836 3837 ``debug`` debug level for spicevmc 3838 3839 ``name`` name of spice port to connect to 3840 3841 Connect to a spice port, allowing a Spice client to handle the 3842 traffic identified by a name (preferably a fqdn). 3843ERST 3844 3845DEFHEADING() 3846 3847#ifdef CONFIG_TPM 3848DEFHEADING(TPM device options:) 3849 3850DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3851 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3852 " use path to provide path to a character device; default is /dev/tpm0\n" 3853 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3854 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3855 "-tpmdev emulator,id=id,chardev=dev\n" 3856 " configure the TPM device using chardev backend\n", 3857 QEMU_ARCH_ALL) 3858SRST 3859The general form of a TPM device option is: 3860 3861``-tpmdev backend,id=id[,options]`` 3862 The specific backend type will determine the applicable options. The 3863 ``-tpmdev`` option creates the TPM backend and requires a 3864 ``-device`` option that specifies the TPM frontend interface model. 3865 3866 Use ``-tpmdev help`` to print all available TPM backend types. 3867 3868The available backends are: 3869 3870``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path`` 3871 (Linux-host only) Enable access to the host's TPM using the 3872 passthrough driver. 3873 3874 ``path`` specifies the path to the host's TPM device, i.e., on a 3875 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by 3876 default ``/dev/tpm0`` is used. 3877 3878 ``cancel-path`` specifies the path to the host TPM device's sysfs 3879 entry allowing for cancellation of an ongoing TPM command. 3880 ``cancel-path`` is optional and by default QEMU will search for the 3881 sysfs entry to use. 3882 3883 Some notes about using the host's TPM with the passthrough driver: 3884 3885 The TPM device accessed by the passthrough driver must not be used 3886 by any other application on the host. 3887 3888 Since the host's firmware (BIOS/UEFI) has already initialized the 3889 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize 3890 the TPM again and may therefore not show a TPM-specific menu that 3891 would otherwise allow the user to configure the TPM, e.g., allow the 3892 user to enable/disable or activate/deactivate the TPM. Further, if 3893 TPM ownership is released from within a VM then the host's TPM will 3894 get disabled and deactivated. To enable and activate the TPM again 3895 afterwards, the host has to be rebooted and the user is required to 3896 enter the firmware's menu to enable and activate the TPM. If the TPM 3897 is left disabled and/or deactivated most TPM commands will fail. 3898 3899 To create a passthrough TPM use the following two options: 3900 3901 :: 3902 3903 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3904 3905 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by 3906 ``tpmdev=tpm0`` in the device option. 3907 3908``-tpmdev emulator,id=id,chardev=dev`` 3909 (Linux-host only) Enable access to a TPM emulator using Unix domain 3910 socket based chardev backend. 3911 3912 ``chardev`` specifies the unique ID of a character device backend 3913 that provides connection to the software TPM server. 3914 3915 To create a TPM emulator backend device with chardev socket backend: 3916 3917 :: 3918 3919 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3920ERST 3921 3922DEFHEADING() 3923 3924#endif 3925 3926DEFHEADING(Boot Image or Kernel specific:) 3927SRST 3928There are broadly 4 ways you can boot a system with QEMU. 3929 3930 - specify a firmware and let it control finding a kernel 3931 - specify a firmware and pass a hint to the kernel to boot 3932 - direct kernel image boot 3933 - manually load files into the guest's address space 3934 3935The third method is useful for quickly testing kernels but as there is 3936no firmware to pass configuration information to the kernel the 3937hardware must either be probeable, the kernel built for the exact 3938configuration or passed some configuration data (e.g. a DTB blob) 3939which tells the kernel what drivers it needs. This exact details are 3940often hardware specific. 3941 3942The final method is the most generic way of loading images into the 3943guest address space and used mostly for ``bare metal`` type 3944development where the reset vectors of the processor are taken into 3945account. 3946 3947ERST 3948 3949SRST 3950 3951For x86 machines and some other architectures ``-bios`` will generally 3952do the right thing with whatever it is given. For other machines the 3953more strict ``-pflash`` option needs an image that is sized for the 3954flash device for the given machine type. 3955 3956Please see the :ref:`system-targets-ref` section of the manual for 3957more detailed documentation. 3958 3959ERST 3960 3961DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3962 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3963SRST 3964``-bios file`` 3965 Set the filename for the BIOS. 3966ERST 3967 3968DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 3969 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 3970SRST 3971``-pflash file`` 3972 Use file as a parallel flash image. 3973ERST 3974 3975SRST 3976 3977The kernel options were designed to work with Linux kernels although 3978other things (like hypervisors) can be packaged up as a kernel 3979executable image. The exact format of a executable image is usually 3980architecture specific. 3981 3982The way in which the kernel is started (what address it is loaded at, 3983what if any information is passed to it via CPU registers, the state 3984of the hardware when it is started, and so on) is also architecture 3985specific. Typically it follows the specification laid down by the 3986Linux kernel for how kernels for that architecture must be started. 3987 3988ERST 3989 3990DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3991 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3992SRST 3993``-kernel bzImage`` 3994 Use bzImage as kernel image. The kernel can be either a Linux kernel 3995 or in multiboot format. 3996ERST 3997 3998DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3999 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 4000SRST 4001``-append cmdline`` 4002 Use cmdline as kernel command line 4003ERST 4004 4005DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 4006 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 4007SRST 4008 4009``-initrd file`` 4010 Use file as initial ram disk. 4011 4012``-initrd "file1 arg=foo,file2"`` 4013 This syntax is only available with multiboot. 4014 4015 Use file1 and file2 as modules and pass ``arg=foo`` as parameter to the 4016 first module. Commas can be provided in module parameters by doubling 4017 them on the command line to escape them: 4018 4019``-initrd "bzImage earlyprintk=xen,,keep root=/dev/xvda1,initrd.img"`` 4020 Multiboot only. Use bzImage as the first module with 4021 "``earlyprintk=xen,keep root=/dev/xvda1``" as its command line, 4022 and initrd.img as the second module. 4023 4024ERST 4025 4026DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 4027 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 4028SRST 4029``-dtb file`` 4030 Use file as a device tree binary (dtb) image and pass it to the 4031 kernel on boot. 4032ERST 4033 4034SRST 4035 4036Finally you can also manually load images directly into the address 4037space of the guest. This is most useful for developers who already 4038know the layout of their guest and take care to ensure something sane 4039will happen when the reset vector executes. 4040 4041The generic loader can be invoked by using the loader device: 4042 4043``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]`` 4044 4045there is also the guest loader which operates in a similar way but 4046tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where 4047the guest image is: 4048 4049``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]`` 4050 4051ERST 4052 4053DEFHEADING() 4054 4055DEFHEADING(Debug/Expert options:) 4056 4057DEF("compat", HAS_ARG, QEMU_OPTION_compat, 4058 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n" 4059 " Policy for handling deprecated management interfaces\n" 4060 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n" 4061 " Policy for handling unstable management interfaces\n", 4062 QEMU_ARCH_ALL) 4063SRST 4064``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]`` 4065 Set policy for handling deprecated management interfaces (experimental): 4066 4067 ``deprecated-input=accept`` (default) 4068 Accept deprecated commands and arguments 4069 ``deprecated-input=reject`` 4070 Reject deprecated commands and arguments 4071 ``deprecated-input=crash`` 4072 Crash on deprecated commands and arguments 4073 ``deprecated-output=accept`` (default) 4074 Emit deprecated command results and events 4075 ``deprecated-output=hide`` 4076 Suppress deprecated command results and events 4077 4078 Limitation: covers only syntactic aspects of QMP. 4079 4080``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]`` 4081 Set policy for handling unstable management interfaces (experimental): 4082 4083 ``unstable-input=accept`` (default) 4084 Accept unstable commands and arguments 4085 ``unstable-input=reject`` 4086 Reject unstable commands and arguments 4087 ``unstable-input=crash`` 4088 Crash on unstable commands and arguments 4089 ``unstable-output=accept`` (default) 4090 Emit unstable command results and events 4091 ``unstable-output=hide`` 4092 Suppress unstable command results and events 4093 4094 Limitation: covers only syntactic aspects of QMP. 4095ERST 4096 4097DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 4098 "-fw_cfg [name=]<name>,file=<file>\n" 4099 " add named fw_cfg entry with contents from file\n" 4100 "-fw_cfg [name=]<name>,string=<str>\n" 4101 " add named fw_cfg entry with contents from string\n", 4102 QEMU_ARCH_ALL) 4103SRST 4104``-fw_cfg [name=]name,file=file`` 4105 Add named fw\_cfg entry with contents from file file. 4106 If the filename contains comma, you must double it (for instance, 4107 "file=my,,file" to use file "my,file"). 4108 4109``-fw_cfg [name=]name,string=str`` 4110 Add named fw\_cfg entry with contents from string str. 4111 If the string contains comma, you must double it (for instance, 4112 "string=my,,string" to use file "my,string"). 4113 4114 The terminating NUL character of the contents of str will not be 4115 included as part of the fw\_cfg item data. To insert contents with 4116 embedded NUL characters, you have to use the file parameter. 4117 4118 The fw\_cfg entries are passed by QEMU through to the guest. 4119 4120 Example: 4121 4122 :: 4123 4124 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 4125 4126 creates an fw\_cfg entry named opt/com.mycompany/blob with contents 4127 from ./my\_blob.bin. 4128ERST 4129 4130DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 4131 "-serial dev redirect the serial port to char device 'dev'\n", 4132 QEMU_ARCH_ALL) 4133SRST 4134``-serial dev`` 4135 Redirect the virtual serial port to host character device dev. The 4136 default device is ``vc`` in graphical mode and ``stdio`` in non 4137 graphical mode. 4138 4139 This option can be used several times to simulate up to 4 serial 4140 ports. 4141 4142 Use ``-serial none`` to disable all serial ports. 4143 4144 Available character devices are: 4145 4146 ``vc[:WxH]`` 4147 Virtual console. Optionally, a width and height can be given in 4148 pixel with 4149 4150 :: 4151 4152 vc:800x600 4153 4154 It is also possible to specify width or height in characters: 4155 4156 :: 4157 4158 vc:80Cx24C 4159 4160 ``pty`` 4161 [Linux only] Pseudo TTY (a new PTY is automatically allocated) 4162 4163 ``none`` 4164 No device is allocated. 4165 4166 ``null`` 4167 void device 4168 4169 ``chardev:id`` 4170 Use a named character device defined with the ``-chardev`` 4171 option. 4172 4173 ``/dev/XXX`` 4174 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial 4175 port parameters are set according to the emulated ones. 4176 4177 ``/dev/parportN`` 4178 [Linux only, parallel port only] Use host parallel port N. 4179 Currently SPP and EPP parallel port features can be used. 4180 4181 ``file:filename`` 4182 Write output to filename. No character can be read. 4183 4184 ``stdio`` 4185 [Unix only] standard input/output 4186 4187 ``pipe:filename`` 4188 name pipe filename 4189 4190 ``COMn`` 4191 [Windows only] Use host serial port n 4192 4193 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]`` 4194 This implements UDP Net Console. When remote\_host or src\_ip 4195 are not specified they default to ``0.0.0.0``. When not using a 4196 specified src\_port a random port is automatically chosen. 4197 4198 If you just want a simple readonly console you can use 4199 ``netcat`` or ``nc``, by starting QEMU with: 4200 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time 4201 QEMU writes something to that port it will appear in the 4202 netconsole session. 4203 4204 If you plan to send characters back via netconsole or you want 4205 to stop and start QEMU a lot of times, you should have QEMU use 4206 the same source port each time by using something like ``-serial 4207 udp::4555@:4556`` to QEMU. Another approach is to use a patched 4208 version of netcat which can listen to a TCP port and send and 4209 receive characters via udp. If you have a patched version of 4210 netcat which activates telnet remote echo and single char 4211 transfer, then you can use the following options to set up a 4212 netcat redirector to allow telnet on port 5555 to access the 4213 QEMU port. 4214 4215 ``QEMU Options:`` 4216 -serial udp::4555@:4556 4217 4218 ``netcat options:`` 4219 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 4220 4221 ``telnet options:`` 4222 localhost 5555 4223 4224 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` 4225 The TCP Net Console has two modes of operation. It can send the 4226 serial I/O to a location or wait for a connection from a 4227 location. By default the TCP Net Console is sent to host at the 4228 port. If you use the ``server=on`` option QEMU will wait for a client 4229 socket application to connect to the port before continuing, 4230 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` 4231 option disables the Nagle buffering algorithm. The ``reconnect=on`` 4232 option only applies if ``server=no`` is set, if the connection goes 4233 down it will attempt to reconnect at the given interval. If host 4234 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a 4235 time is accepted. You can use ``telnet=on`` to connect to the 4236 corresponding character device. 4237 4238 ``Example to send tcp console to 192.168.0.2 port 4444`` 4239 -serial tcp:192.168.0.2:4444 4240 4241 ``Example to listen and wait on port 4444 for connection`` 4242 -serial tcp::4444,server=on 4243 4244 ``Example to not wait and listen on ip 192.168.0.100 port 4444`` 4245 -serial tcp:192.168.0.100:4444,server=on,wait=off 4246 4247 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` 4248 The telnet protocol is used instead of raw tcp sockets. The 4249 options work the same as if you had specified ``-serial tcp``. 4250 The difference is that the port acts like a telnet server or 4251 client using telnet option negotiation. This will also allow you 4252 to send the MAGIC\_SYSRQ sequence if you use a telnet that 4253 supports sending the break sequence. Typically in unix telnet 4254 you do it with Control-] and then type "send break" followed by 4255 pressing the enter key. 4256 4257 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` 4258 The WebSocket protocol is used instead of raw tcp socket. The 4259 port acts as a WebSocket server. Client mode is not supported. 4260 4261 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]`` 4262 A unix domain socket is used instead of a tcp socket. The option 4263 works the same as if you had specified ``-serial tcp`` except 4264 the unix domain socket path is used for connections. 4265 4266 ``mon:dev_string`` 4267 This is a special option to allow the monitor to be multiplexed 4268 onto another serial port. The monitor is accessed with key 4269 sequence of Control-a and then pressing c. dev\_string should be 4270 any one of the serial devices specified above. An example to 4271 multiplex the monitor onto a telnet server listening on port 4272 4444 would be: 4273 4274 ``-serial mon:telnet::4444,server=on,wait=off`` 4275 4276 When the monitor is multiplexed to stdio in this way, Ctrl+C 4277 will not terminate QEMU any more but will be passed to the guest 4278 instead. 4279 4280 ``braille`` 4281 Braille device. This will use BrlAPI to display the braille 4282 output on a real or fake device. 4283 4284 ``msmouse`` 4285 Three button serial mouse. Configure the guest to use Microsoft 4286 protocol. 4287ERST 4288 4289DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 4290 "-parallel dev redirect the parallel port to char device 'dev'\n", 4291 QEMU_ARCH_ALL) 4292SRST 4293``-parallel dev`` 4294 Redirect the virtual parallel port to host device dev (same devices 4295 as the serial port). On Linux hosts, ``/dev/parportN`` can be used 4296 to use hardware devices connected on the corresponding host parallel 4297 port. 4298 4299 This option can be used several times to simulate up to 3 parallel 4300 ports. 4301 4302 Use ``-parallel none`` to disable all parallel ports. 4303ERST 4304 4305DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 4306 "-monitor dev redirect the monitor to char device 'dev'\n", 4307 QEMU_ARCH_ALL) 4308SRST 4309``-monitor dev`` 4310 Redirect the monitor to host device dev (same devices as the serial 4311 port). The default device is ``vc`` in graphical mode and ``stdio`` 4312 in non graphical mode. Use ``-monitor none`` to disable the default 4313 monitor. 4314ERST 4315DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 4316 "-qmp dev like -monitor but opens in 'control' mode\n", 4317 QEMU_ARCH_ALL) 4318SRST 4319``-qmp dev`` 4320 Like ``-monitor`` but opens in 'control' mode. For example, to make 4321 QMP available on localhost port 4444:: 4322 4323 -qmp tcp:localhost:4444,server=on,wait=off 4324 4325 Not all options are configurable via this syntax; for maximum 4326 flexibility use the ``-mon`` option and an accompanying ``-chardev``. 4327 4328ERST 4329DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 4330 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 4331 QEMU_ARCH_ALL) 4332SRST 4333``-qmp-pretty dev`` 4334 Like ``-qmp`` but uses pretty JSON formatting. 4335ERST 4336 4337DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 4338 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 4339SRST 4340``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]`` 4341 Set up a monitor connected to the chardev ``name``. 4342 QEMU supports two monitors: the Human Monitor Protocol 4343 (HMP; for human interaction), and the QEMU Monitor Protocol 4344 (QMP; a JSON RPC-style protocol). 4345 The default is HMP; ``mode=control`` selects QMP instead. 4346 ``pretty`` is only valid when ``mode=control``, 4347 turning on JSON pretty printing to ease 4348 human reading and debugging. 4349 4350 For example:: 4351 4352 -chardev socket,id=mon1,host=localhost,port=4444,server=on,wait=off \ 4353 -mon chardev=mon1,mode=control,pretty=on 4354 4355 enables the QMP monitor on localhost port 4444 with pretty-printing. 4356ERST 4357 4358DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 4359 "-debugcon dev redirect the debug console to char device 'dev'\n", 4360 QEMU_ARCH_ALL) 4361SRST 4362``-debugcon dev`` 4363 Redirect the debug console to host device dev (same devices as the 4364 serial port). The debug console is an I/O port which is typically 4365 port 0xe9; writing to that I/O port sends output to this device. The 4366 default device is ``vc`` in graphical mode and ``stdio`` in non 4367 graphical mode. 4368ERST 4369 4370DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 4371 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 4372SRST 4373``-pidfile file`` 4374 Store the QEMU process PID in file. It is useful if you launch QEMU 4375 from a script. 4376ERST 4377 4378DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 4379 "-singlestep deprecated synonym for -accel tcg,one-insn-per-tb=on\n", QEMU_ARCH_ALL) 4380SRST 4381``-singlestep`` 4382 This is a deprecated synonym for the TCG accelerator property 4383 ``one-insn-per-tb``. 4384ERST 4385 4386DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 4387 "--preconfig pause QEMU before machine is initialized (experimental)\n", 4388 QEMU_ARCH_ALL) 4389SRST 4390``--preconfig`` 4391 Pause QEMU for interactive configuration before the machine is 4392 created, which allows querying and configuring properties that will 4393 affect machine initialization. Use QMP command 'x-exit-preconfig' to 4394 exit the preconfig state and move to the next state (i.e. run guest 4395 if -S isn't used or pause the second time if -S is used). This 4396 option is experimental. 4397ERST 4398 4399DEF("S", 0, QEMU_OPTION_S, \ 4400 "-S freeze CPU at startup (use 'c' to start execution)\n", 4401 QEMU_ARCH_ALL) 4402SRST 4403``-S`` 4404 Do not start CPU at startup (you must type 'c' in the monitor). 4405ERST 4406 4407DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 4408 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 4409 " run qemu with overcommit hints\n" 4410 " mem-lock=on|off controls memory lock support (default: off)\n" 4411 " cpu-pm=on|off controls cpu power management (default: off)\n", 4412 QEMU_ARCH_ALL) 4413SRST 4414``-overcommit mem-lock=on|off`` 4415 \ 4416``-overcommit cpu-pm=on|off`` 4417 Run qemu with hints about host resource overcommit. The default is 4418 to assume that host overcommits all resources. 4419 4420 Locking qemu and guest memory can be enabled via ``mem-lock=on`` 4421 (disabled by default). This works when host memory is not 4422 overcommitted and reduces the worst-case latency for guest. 4423 4424 Guest ability to manage power state of host cpus (increasing latency 4425 for other processes on the same host cpu, but decreasing latency for 4426 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This 4427 works best when host CPU is not overcommitted. When used, host 4428 estimates of CPU cycle and power utilization will be incorrect, not 4429 taking into account guest idle time. 4430ERST 4431 4432DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 4433 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n" 4434 " the guest without waiting for gdb to connect; use -S too\n" 4435 " if you want it to not start execution.)\n", 4436 QEMU_ARCH_ALL) 4437SRST 4438``-gdb dev`` 4439 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter 4440 in the System Emulation Users Guide). Note that this option does not pause QEMU 4441 execution -- if you want QEMU to not start the guest until you 4442 connect with gdb and issue a ``continue`` command, you will need to 4443 also pass the ``-S`` option to QEMU. 4444 4445 The most usual configuration is to listen on a local TCP socket:: 4446 4447 -gdb tcp::3117 4448 4449 but you can specify other backends; UDP, pseudo TTY, or even stdio 4450 are all reasonable use cases. For example, a stdio connection 4451 allows you to start QEMU from within gdb and establish the 4452 connection via a pipe: 4453 4454 .. parsed-literal:: 4455 4456 (gdb) target remote | exec |qemu_system| -gdb stdio ... 4457ERST 4458 4459DEF("s", 0, QEMU_OPTION_s, \ 4460 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 4461 QEMU_ARCH_ALL) 4462SRST 4463``-s`` 4464 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 4465 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide). 4466ERST 4467 4468DEF("d", HAS_ARG, QEMU_OPTION_d, \ 4469 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 4470 QEMU_ARCH_ALL) 4471SRST 4472``-d item1[,...]`` 4473 Enable logging of specified items. Use '-d help' for a list of log 4474 items. 4475ERST 4476 4477DEF("D", HAS_ARG, QEMU_OPTION_D, \ 4478 "-D logfile output log to logfile (default stderr)\n", 4479 QEMU_ARCH_ALL) 4480SRST 4481``-D logfile`` 4482 Output log in logfile instead of to stderr 4483ERST 4484 4485DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 4486 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 4487 QEMU_ARCH_ALL) 4488SRST 4489``-dfilter range1[,...]`` 4490 Filter debug output to that relevant to a range of target addresses. 4491 The filter spec can be either start+size, start-size or start..end 4492 where start end and size are the addresses and sizes required. For 4493 example: 4494 4495 :: 4496 4497 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 4498 4499 Will dump output for any code in the 0x1000 sized block starting at 4500 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and 4501 another 0x1000 sized block starting at 0xffffffc00005f000. 4502ERST 4503 4504DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 4505 "-seed number seed the pseudo-random number generator\n", 4506 QEMU_ARCH_ALL) 4507SRST 4508``-seed number`` 4509 Force the guest to use a deterministic pseudo-random number 4510 generator, seeded with number. This does not affect crypto routines 4511 within the host. 4512ERST 4513 4514DEF("L", HAS_ARG, QEMU_OPTION_L, \ 4515 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 4516 QEMU_ARCH_ALL) 4517SRST 4518``-L path`` 4519 Set the directory for the BIOS, VGA BIOS and keymaps. 4520 4521 To list all the data directories, use ``-L help``. 4522ERST 4523 4524DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 4525 "-enable-kvm enable KVM full virtualization support\n", 4526 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC | 4527 QEMU_ARCH_RISCV | QEMU_ARCH_S390X) 4528SRST 4529``-enable-kvm`` 4530 Enable KVM full virtualization support. This option is only 4531 available if KVM support is enabled when compiling. 4532ERST 4533 4534DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 4535 "-xen-domid id specify xen guest domain id\n", 4536 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4537DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 4538 "-xen-attach attach to existing xen domain\n" 4539 " libxl will use this when starting QEMU\n", 4540 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4541DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 4542 "-xen-domid-restrict restrict set of available xen operations\n" 4543 " to specified domain id. (Does not affect\n" 4544 " xenpv machine type).\n", 4545 QEMU_ARCH_ARM | QEMU_ARCH_I386) 4546SRST 4547``-xen-domid id`` 4548 Specify xen guest domain id (XEN only). 4549 4550``-xen-attach`` 4551 Attach to existing xen domain. libxl will use this when starting 4552 QEMU (XEN only). Restrict set of available xen operations to 4553 specified domain id (XEN only). 4554ERST 4555 4556DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 4557 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 4558SRST 4559``-no-reboot`` 4560 Exit instead of rebooting. 4561ERST 4562 4563DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 4564 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 4565SRST 4566``-no-shutdown`` 4567 Don't exit QEMU on guest shutdown, but instead only stop the 4568 emulation. This allows for instance switching to monitor to commit 4569 changes to the disk image. 4570ERST 4571 4572DEF("action", HAS_ARG, QEMU_OPTION_action, 4573 "-action reboot=reset|shutdown\n" 4574 " action when guest reboots [default=reset]\n" 4575 "-action shutdown=poweroff|pause\n" 4576 " action when guest shuts down [default=poweroff]\n" 4577 "-action panic=pause|shutdown|exit-failure|none\n" 4578 " action when guest panics [default=shutdown]\n" 4579 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" 4580 " action when watchdog fires [default=reset]\n", 4581 QEMU_ARCH_ALL) 4582SRST 4583``-action event=action`` 4584 The action parameter serves to modify QEMU's default behavior when 4585 certain guest events occur. It provides a generic method for specifying the 4586 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown`` 4587 parameters. 4588 4589 Examples: 4590 4591 ``-action panic=none`` 4592 ``-action reboot=shutdown,shutdown=pause`` 4593 ``-device i6300esb -action watchdog=pause`` 4594 4595ERST 4596 4597DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 4598 "-loadvm [tag|id]\n" \ 4599 " start right away with a saved state (loadvm in monitor)\n", 4600 QEMU_ARCH_ALL) 4601SRST 4602``-loadvm file`` 4603 Start right away with a saved state (``loadvm`` in monitor) 4604ERST 4605 4606#ifndef _WIN32 4607DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 4608 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 4609#endif 4610SRST 4611``-daemonize`` 4612 Daemonize the QEMU process after initialization. QEMU will not 4613 detach from standard IO until it is ready to receive connections on 4614 any of its devices. This option is a useful way for external 4615 programs to launch QEMU without having to cope with initialization 4616 race conditions. 4617ERST 4618 4619DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 4620 "-option-rom rom load a file, rom, into the option ROM space\n", 4621 QEMU_ARCH_ALL) 4622SRST 4623``-option-rom file`` 4624 Load the contents of file as an option ROM. This option is useful to 4625 load things like EtherBoot. 4626ERST 4627 4628DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 4629 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 4630 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 4631 QEMU_ARCH_ALL) 4632 4633SRST 4634``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]`` 4635 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at 4636 the current UTC or local time, respectively. ``localtime`` is 4637 required for correct date in MS-DOS or Windows. To start at a 4638 specific point in time, provide datetime in the format 4639 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC. 4640 4641 By default the RTC is driven by the host system time. This allows 4642 using of the RTC as accurate reference clock inside the guest, 4643 specifically if the host time is smoothly following an accurate 4644 external reference clock, e.g. via NTP. If you want to isolate the 4645 guest time from the host, you can set ``clock`` to ``rt`` instead, 4646 which provides a host monotonic clock if host support it. To even 4647 prevent the RTC from progressing during suspension, you can set 4648 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is 4649 recommended especially in icount mode in order to preserve 4650 determinism; however, note that in icount mode the speed of the 4651 virtual clock is variable and can in general differ from the host 4652 clock. 4653 4654 Enable ``driftfix`` (i386 targets only) if you experience time drift 4655 problems, specifically with Windows' ACPI HAL. This option will try 4656 to figure out how many timer interrupts were not processed by the 4657 Windows guest and will re-inject them. 4658ERST 4659 4660DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 4661 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \ 4662 " enable virtual instruction counter with 2^N clock ticks per\n" \ 4663 " instruction, enable aligning the host and virtual clocks\n" \ 4664 " or disable real time cpu sleeping, and optionally enable\n" \ 4665 " record-and-replay mode\n", QEMU_ARCH_ALL) 4666SRST 4667``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` 4668 Enable virtual instruction counter. The virtual cpu will execute one 4669 instruction every 2^N ns of virtual time. If ``auto`` is specified 4670 then the virtual cpu speed will be automatically adjusted to keep 4671 virtual time within a few seconds of real time. 4672 4673 Note that while this option can give deterministic behavior, it does 4674 not provide cycle accurate emulation. Modern CPUs contain 4675 superscalar out of order cores with complex cache hierarchies. The 4676 number of instructions executed often has little or no correlation 4677 with actual performance. 4678 4679 When the virtual cpu is sleeping, the virtual time will advance at 4680 default speed unless ``sleep=on`` is specified. With 4681 ``sleep=on``, the virtual time will jump to the next timer 4682 deadline instantly whenever the virtual cpu goes to sleep mode and 4683 will not advance if no timer is enabled. This behavior gives 4684 deterministic execution times from the guest point of view. 4685 The default if icount is enabled is ``sleep=off``. 4686 ``sleep=on`` cannot be used together with either ``shift=auto`` 4687 or ``align=on``. 4688 4689 ``align=on`` will activate the delay algorithm which will try to 4690 synchronise the host clock and the virtual clock. The goal is to 4691 have a guest running at the real frequency imposed by the shift 4692 option. Whenever the guest clock is behind the host clock and if 4693 ``align=on`` is specified then we print a message to the user to 4694 inform about the delay. Currently this option does not work when 4695 ``shift`` is ``auto``. Note: The sync algorithm will work for those 4696 shift values for which the guest clock runs ahead of the host clock. 4697 Typically this happens when the shift value is high (how high 4698 depends on the host machine). The default if icount is enabled 4699 is ``align=off``. 4700 4701 When the ``rr`` option is specified deterministic record/replay is 4702 enabled. The ``rrfile=`` option must also be provided to 4703 specify the path to the replay log. In record mode data is written 4704 to this file, and in replay mode it is read back. 4705 If the ``rrsnapshot`` option is given then it specifies a VM snapshot 4706 name. In record mode, a new VM snapshot with the given name is created 4707 at the start of execution recording. In replay mode this option 4708 specifies the snapshot name used to load the initial VM state. 4709ERST 4710 4711DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 4712 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 4713 " action when watchdog fires [default=reset]\n", 4714 QEMU_ARCH_ALL) 4715SRST 4716``-watchdog-action action`` 4717 The action controls what QEMU will do when the watchdog timer 4718 expires. The default is ``reset`` (forcefully reset the guest). 4719 Other possible actions are: ``shutdown`` (attempt to gracefully 4720 shutdown the guest), ``poweroff`` (forcefully poweroff the guest), 4721 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the 4722 guest), ``debug`` (print a debug message and continue), or ``none`` 4723 (do nothing). 4724 4725 Note that the ``shutdown`` action requires that the guest responds 4726 to ACPI signals, which it may not be able to do in the sort of 4727 situations where the watchdog would have expired, and thus 4728 ``-watchdog-action shutdown`` is not recommended for production use. 4729 4730 Examples: 4731 4732 ``-device i6300esb -watchdog-action pause`` 4733 4734ERST 4735 4736DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 4737 "-echr chr set terminal escape character instead of ctrl-a\n", 4738 QEMU_ARCH_ALL) 4739SRST 4740``-echr numeric_ascii_value`` 4741 Change the escape character used for switching to the monitor when 4742 using monitor and serial sharing. The default is ``0x01`` when using 4743 the ``-nographic`` option. ``0x01`` is equal to pressing 4744 ``Control-a``. You can select a different character from the ascii 4745 control keys where 1 through 26 map to Control-a through Control-z. 4746 For instance you could use the either of the following to change the 4747 escape character to Control-t. 4748 4749 ``-echr 0x14``; \ ``-echr 20`` 4750 4751ERST 4752 4753DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4754 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \ 4755 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \ 4756 "-incoming unix:socketpath\n" \ 4757 " prepare for incoming migration, listen on\n" \ 4758 " specified protocol and socket address\n" \ 4759 "-incoming fd:fd\n" \ 4760 "-incoming file:filename[,offset=offset]\n" \ 4761 "-incoming exec:cmdline\n" \ 4762 " accept incoming migration on given file descriptor\n" \ 4763 " or from given external command\n" \ 4764 "-incoming defer\n" \ 4765 " wait for the URI to be specified via migrate_incoming\n", 4766 QEMU_ARCH_ALL) 4767SRST 4768``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]`` 4769 \ 4770``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]`` 4771 Prepare for incoming migration, listen on a given tcp port. 4772 4773``-incoming unix:socketpath`` 4774 Prepare for incoming migration, listen on a given unix socket. 4775 4776``-incoming fd:fd`` 4777 Accept incoming migration from a given file descriptor. 4778 4779``-incoming file:filename[,offset=offset]`` 4780 Accept incoming migration from a given file starting at offset. 4781 offset allows the common size suffixes, or a 0x prefix, but not both. 4782 4783``-incoming exec:cmdline`` 4784 Accept incoming migration as an output from specified external 4785 command. 4786 4787``-incoming defer`` 4788 Wait for the URI to be specified via migrate\_incoming. The monitor 4789 can be used to change settings (such as migration parameters) prior 4790 to issuing the migrate\_incoming to allow the migration to begin. 4791ERST 4792 4793DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4794 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4795SRST 4796``-only-migratable`` 4797 Only allow migratable devices. Devices will not be allowed to enter 4798 an unmigratable state. 4799ERST 4800 4801DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4802 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4803SRST 4804``-nodefaults`` 4805 Don't create default devices. Normally, QEMU sets the default 4806 devices like serial port, parallel port, virtual console, monitor 4807 device, VGA adapter, floppy and CD-ROM drive and others. The 4808 ``-nodefaults`` option will disable all those default devices. 4809ERST 4810 4811#ifndef _WIN32 4812DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4813 "-chroot dir chroot to dir just before starting the VM (deprecated)\n", 4814 QEMU_ARCH_ALL) 4815#endif 4816SRST 4817``-chroot dir`` 4818 Deprecated, use '-run-with chroot=...' instead. 4819 Immediately before starting guest execution, chroot to the specified 4820 directory. Especially useful in combination with -runas. 4821ERST 4822 4823#ifndef _WIN32 4824DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4825 "-runas user change to user id user just before starting the VM\n" \ 4826 " user can be numeric uid:gid instead\n", 4827 QEMU_ARCH_ALL) 4828#endif 4829SRST 4830``-runas user`` 4831 Immediately before starting guest execution, drop root privileges, 4832 switching to the specified user. 4833ERST 4834 4835DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4836 "-prom-env variable=value\n" 4837 " set OpenBIOS nvram variables\n", 4838 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4839SRST 4840``-prom-env variable=value`` 4841 Set OpenBIOS nvram variable to given value (PPC, SPARC only). 4842 4843 :: 4844 4845 qemu-system-sparc -prom-env 'auto-boot?=false' \ 4846 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single' 4847 4848 :: 4849 4850 qemu-system-ppc -prom-env 'auto-boot?=false' \ 4851 -prom-env 'boot-device=hd:2,\yaboot' \ 4852 -prom-env 'boot-args=conf=hd:2,\yaboot.conf' 4853ERST 4854DEF("semihosting", 0, QEMU_OPTION_semihosting, 4855 "-semihosting semihosting mode\n", 4856 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4857 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4858SRST 4859``-semihosting`` 4860 Enable :ref:`Semihosting` mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only). 4861 4862 .. warning:: 4863 Note that this allows guest direct access to the host filesystem, so 4864 should only be used with a trusted guest OS. 4865 4866 See the -semihosting-config option documentation for further 4867 information about the facilities this enables. 4868ERST 4869DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4870 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \ 4871 " semihosting configuration\n", 4872QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | 4873QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV) 4874SRST 4875``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]`` 4876 Enable and configure :ref:`Semihosting` (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V 4877 only). 4878 4879 .. warning:: 4880 Note that this allows guest direct access to the host filesystem, so 4881 should only be used with a trusted guest OS. 4882 4883 ``target=native|gdb|auto`` 4884 Defines where the semihosting calls will be addressed, to QEMU 4885 (``native``) or to GDB (``gdb``). The default is ``auto``, which 4886 means ``gdb`` during debug sessions and ``native`` otherwise. 4887 4888 ``chardev=str1`` 4889 Send the output to a chardev backend output for native or auto 4890 output when not in gdb 4891 4892 ``userspace=on|off`` 4893 Allows code running in guest userspace to access the semihosting 4894 interface. The default is that only privileged guest code can 4895 make semihosting calls. Note that setting ``userspace=on`` should 4896 only be used if all guest code is trusted (for example, in 4897 bare-metal test case code). 4898 4899 ``arg=str1,arg=str2,...`` 4900 Allows the user to pass input arguments, and can be used 4901 multiple times to build up a list. The old-style 4902 ``-kernel``/``-append`` method of passing a command line is 4903 still supported for backward compatibility. If both the 4904 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are 4905 specified, the former is passed to semihosting as it always 4906 takes precedence. 4907ERST 4908DEF("old-param", 0, QEMU_OPTION_old_param, 4909 "-old-param old param mode\n", QEMU_ARCH_ARM) 4910SRST 4911``-old-param`` 4912 Old param mode (ARM only). 4913ERST 4914 4915DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4916 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4917 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4918 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4919 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4920 " by the kernel, but typically no longer used by modern\n" \ 4921 " C library implementations.\n" \ 4922 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \ 4923 " to elevate privileges using set*uid|gid system calls.\n" \ 4924 " The value 'children' will deny set*uid|gid system calls for\n" \ 4925 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4926 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4927 " blocking *fork and execve\n" \ 4928 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4929 QEMU_ARCH_ALL) 4930SRST 4931``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]`` 4932 Enable Seccomp mode 2 system call filter. 'on' will enable syscall 4933 filtering and 'off' will disable it. The default is 'off'. 4934 4935 ``obsolete=string`` 4936 Enable Obsolete system calls 4937 4938 ``elevateprivileges=string`` 4939 Disable set\*uid\|gid system calls 4940 4941 ``spawn=string`` 4942 Disable \*fork and execve 4943 4944 ``resourcecontrol=string`` 4945 Disable process affinity and schedular priority 4946ERST 4947 4948DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4949 "-readconfig <file>\n" 4950 " read config file\n", QEMU_ARCH_ALL) 4951SRST 4952``-readconfig file`` 4953 Read device configuration from file. This approach is useful when 4954 you want to spawn QEMU process with many command line options but 4955 you don't want to exceed the command line character limit. 4956ERST 4957 4958DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4959 "-no-user-config\n" 4960 " do not load default user-provided config files at startup\n", 4961 QEMU_ARCH_ALL) 4962SRST 4963``-no-user-config`` 4964 The ``-no-user-config`` option makes QEMU not load any of the 4965 user-provided config files on sysconfdir. 4966ERST 4967 4968DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4969 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4970 " specify tracing options\n", 4971 QEMU_ARCH_ALL) 4972SRST 4973``-trace [[enable=]pattern][,events=file][,file=file]`` 4974 .. include:: ../qemu-option-trace.rst.inc 4975 4976ERST 4977DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4978 "-plugin [file=]<file>[,<argname>=<argvalue>]\n" 4979 " load a plugin\n", 4980 QEMU_ARCH_ALL) 4981SRST 4982``-plugin file=file[,argname=argvalue]`` 4983 Load a plugin. 4984 4985 ``file=file`` 4986 Load the given plugin from a shared library file. 4987 4988 ``argname=argvalue`` 4989 Argument passed to the plugin. (Can be given multiple times.) 4990ERST 4991 4992HXCOMM Internal use 4993DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4994DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4995 4996#ifdef __linux__ 4997DEF("async-teardown", 0, QEMU_OPTION_asyncteardown, 4998 "-async-teardown enable asynchronous teardown\n", 4999 QEMU_ARCH_ALL) 5000SRST 5001``-async-teardown`` 5002 This option is deprecated and should no longer be used. The new option 5003 ``-run-with async-teardown=on`` is a replacement. 5004ERST 5005#endif 5006#ifdef CONFIG_POSIX 5007DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, 5008 "-run-with [async-teardown=on|off][,chroot=dir]\n" 5009 " Set miscellaneous QEMU process lifecycle options:\n" 5010 " async-teardown=on enables asynchronous teardown (Linux only)\n" 5011 " chroot=dir chroot to dir just before starting the VM\n", 5012 QEMU_ARCH_ALL) 5013SRST 5014``-run-with [async-teardown=on|off][,chroot=dir]`` 5015 Set QEMU process lifecycle options. 5016 5017 ``async-teardown=on`` enables asynchronous teardown. A new process called 5018 "cleanup/<QEMU_PID>" will be created at startup sharing the address 5019 space with the main QEMU process, using clone. It will wait for the 5020 main QEMU process to terminate completely, and then exit. This allows 5021 QEMU to terminate very quickly even if the guest was huge, leaving the 5022 teardown of the address space to the cleanup process. Since the cleanup 5023 process shares the same cgroups as the main QEMU process, accounting is 5024 performed correctly. This only works if the cleanup process is not 5025 forcefully killed with SIGKILL before the main QEMU process has 5026 terminated completely. 5027 5028 ``chroot=dir`` can be used for doing a chroot to the specified directory 5029 immediately before starting the guest execution. This is especially useful 5030 in combination with -runas. 5031ERST 5032#endif 5033 5034DEF("msg", HAS_ARG, QEMU_OPTION_msg, 5035 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n" 5036 " control error message format\n" 5037 " timestamp=on enables timestamps (default: off)\n" 5038 " guest-name=on enables guest name prefix but only if\n" 5039 " -name guest option is set (default: off)\n", 5040 QEMU_ARCH_ALL) 5041SRST 5042``-msg [timestamp[=on|off]][,guest-name[=on|off]]`` 5043 Control error message format. 5044 5045 ``timestamp=on|off`` 5046 Prefix messages with a timestamp. Default is off. 5047 5048 ``guest-name=on|off`` 5049 Prefix messages with guest name but only if -name guest option is set 5050 otherwise the option is ignored. Default is off. 5051ERST 5052 5053DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 5054 "-dump-vmstate <file>\n" 5055 " Output vmstate information in JSON format to file.\n" 5056 " Use the scripts/vmstate-static-checker.py file to\n" 5057 " check for possible regressions in migration code\n" 5058 " by comparing two such vmstate dumps.\n", 5059 QEMU_ARCH_ALL) 5060SRST 5061``-dump-vmstate file`` 5062 Dump json-encoded vmstate information for current machine type to 5063 file in file 5064ERST 5065 5066DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 5067 "-enable-sync-profile\n" 5068 " enable synchronization profiling\n", 5069 QEMU_ARCH_ALL) 5070SRST 5071``-enable-sync-profile`` 5072 Enable synchronization profiling. 5073ERST 5074 5075#if defined(CONFIG_TCG) && defined(CONFIG_LINUX) 5076DEF("perfmap", 0, QEMU_OPTION_perfmap, 5077 "-perfmap generate a /tmp/perf-${pid}.map file for perf\n", 5078 QEMU_ARCH_ALL) 5079SRST 5080``-perfmap`` 5081 Generate a map file for Linux perf tools that will allow basic profiling 5082 information to be broken down into basic blocks. 5083ERST 5084 5085DEF("jitdump", 0, QEMU_OPTION_jitdump, 5086 "-jitdump generate a jit-${pid}.dump file for perf\n", 5087 QEMU_ARCH_ALL) 5088SRST 5089``-jitdump`` 5090 Generate a dump file for Linux perf tools that maps basic blocks to symbol 5091 names, line numbers and JITted code. 5092ERST 5093#endif 5094 5095DEFHEADING() 5096 5097DEFHEADING(Generic object creation:) 5098 5099DEF("object", HAS_ARG, QEMU_OPTION_object, 5100 "-object TYPENAME[,PROP1=VALUE1,...]\n" 5101 " create a new object of type TYPENAME setting properties\n" 5102 " in the order they are specified. Note that the 'id'\n" 5103 " property must be set. These objects are placed in the\n" 5104 " '/objects' path.\n", 5105 QEMU_ARCH_ALL) 5106SRST 5107``-object typename[,prop1=value1,...]`` 5108 Create a new object of type typename setting properties in the order 5109 they are specified. Note that the 'id' property must be set. These 5110 objects are placed in the '/objects' path. 5111 5112 ``-object memory-backend-file,id=id,size=size,mem-path=dir,share=on|off,discard-data=on|off,merge=on|off,dump=on|off,prealloc=on|off,host-nodes=host-nodes,policy=default|preferred|bind|interleave,align=align,offset=offset,readonly=on|off,rom=on|off|auto`` 5113 Creates a memory file backend object, which can be used to back 5114 the guest RAM with huge pages. 5115 5116 The ``id`` parameter is a unique ID that will be used to 5117 reference this memory region in other parameters, e.g. ``-numa``, 5118 ``-device nvdimm``, etc. 5119 5120 The ``size`` option provides the size of the memory region, and 5121 accepts common suffixes, e.g. ``500M``. 5122 5123 The ``mem-path`` provides the path to either a shared memory or 5124 huge page filesystem mount. 5125 5126 The ``share`` boolean option determines whether the memory 5127 region is marked as private to QEMU, or shared. The latter 5128 allows a co-operating external process to access the QEMU memory 5129 region. 5130 5131 The ``share`` is also required for pvrdma devices due to 5132 limitations in the RDMA API provided by Linux. 5133 5134 Setting share=on might affect the ability to configure NUMA 5135 bindings for the memory backend under some circumstances, see 5136 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel 5137 source tree for additional details. 5138 5139 Setting the ``discard-data`` boolean option to on indicates that 5140 file contents can be destroyed when QEMU exits, to avoid 5141 unnecessarily flushing data to the backing file. Note that 5142 ``discard-data`` is only an optimization, and QEMU might not 5143 discard file contents if it aborts unexpectedly or is terminated 5144 using SIGKILL. 5145 5146 The ``merge`` boolean option enables memory merge, also known as 5147 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider 5148 the pages for memory deduplication. 5149 5150 Setting the ``dump`` boolean option to off excludes the memory 5151 from core dumps. This feature is also known as MADV\_DONTDUMP. 5152 5153 The ``prealloc`` boolean option enables memory preallocation. 5154 5155 The ``host-nodes`` option binds the memory range to a list of 5156 NUMA host nodes. 5157 5158 The ``policy`` option sets the NUMA policy to one of the 5159 following values: 5160 5161 ``default`` 5162 default host policy 5163 5164 ``preferred`` 5165 prefer the given host node list for allocation 5166 5167 ``bind`` 5168 restrict memory allocation to the given host node list 5169 5170 ``interleave`` 5171 interleave memory allocations across the given host node 5172 list 5173 5174 The ``align`` option specifies the base address alignment when 5175 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg 5176 ``2M``. Some backend store specified by ``mem-path`` requires an 5177 alignment different than the default one used by QEMU, eg the 5178 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 5179 such cases, users can specify the required alignment via this 5180 option. 5181 5182 The ``offset`` option specifies the offset into the target file 5183 that the region starts at. You can use this parameter to back 5184 multiple regions with a single file. 5185 5186 The ``pmem`` option specifies whether the backing file specified 5187 by ``mem-path`` is in host persistent memory that can be 5188 accessed using the SNIA NVM programming model (e.g. Intel 5189 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary 5190 operations to guarantee the persistence of its own writes to 5191 ``mem-path`` (e.g. in vNVDIMM label emulation and live 5192 migration). Also, we will map the backend-file with MAP\_SYNC 5193 flag, which ensures the file metadata is in sync for 5194 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC 5195 requires support from both the host kernel (since Linux kernel 5196 4.15) and the filesystem of ``mem-path`` mounted with DAX 5197 option. 5198 5199 The ``readonly`` option specifies whether the backing file is opened 5200 read-only or read-write (default). 5201 5202 The ``rom`` option specifies whether to create Read Only Memory 5203 (ROM) that cannot be modified by the VM. Any write attempts to such 5204 ROM will be denied. Most use cases want proper RAM instead of ROM. 5205 However, selected use cases, like R/O NVDIMMs, can benefit from 5206 ROM. If set to ``on``, create ROM; if set to ``off``, create 5207 writable RAM; if set to ``auto`` (default), the value of the 5208 ``readonly`` option is used. This option is primarily helpful when 5209 we want to have writable RAM in configurations that would 5210 traditionally create ROM before the ``rom`` option was introduced: 5211 VM templating, where we want to open a file readonly 5212 (``readonly=on``) and mark the memory to be private for QEMU 5213 (``share=off``). For this use case, we need writable RAM instead 5214 of ROM, and want to also set ``rom=off``. 5215 5216 ``-object memory-backend-ram,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave`` 5217 Creates a memory backend object, which can be used to back the 5218 guest RAM. Memory backend objects offer more control than the 5219 ``-m`` option that is traditionally used to define guest RAM. 5220 Please refer to ``memory-backend-file`` for a description of the 5221 options. 5222 5223 ``-object memory-backend-memfd,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave,seal=on|off,hugetlb=on|off,hugetlbsize=size`` 5224 Creates an anonymous memory file backend object, which allows 5225 QEMU to share the memory with an external process (e.g. when 5226 using vhost-user). The memory is allocated with memfd and 5227 optional sealing. (Linux only) 5228 5229 The ``seal`` option creates a sealed-file, that will block 5230 further resizing the memory ('on' by default). 5231 5232 The ``hugetlb`` option specify the file to be created resides in 5233 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction 5234 with the ``hugetlb`` option, the ``hugetlbsize`` option specify 5235 the hugetlb page size on systems that support multiple hugetlb 5236 page sizes (it must be a power of 2 value supported by the 5237 system). 5238 5239 In some versions of Linux, the ``hugetlb`` option is 5240 incompatible with the ``seal`` option (requires at least Linux 5241 4.16). 5242 5243 Please refer to ``memory-backend-file`` for a description of the 5244 other options. 5245 5246 The ``share`` boolean option is on by default with memfd. 5247 5248 ``-object iommufd,id=id[,fd=fd]`` 5249 Creates an iommufd backend which allows control of DMA mapping 5250 through the ``/dev/iommu`` device. 5251 5252 The ``id`` parameter is a unique ID which frontends (such as 5253 vfio-pci of vdpa) will use to connect with the iommufd backend. 5254 5255 The ``fd`` parameter is an optional pre-opened file descriptor 5256 resulting from ``/dev/iommu`` opening. Usually the iommufd is shared 5257 across all subsystems, bringing the benefit of centralized 5258 reference counting. 5259 5260 ``-object rng-builtin,id=id`` 5261 Creates a random number generator backend which obtains entropy 5262 from QEMU builtin functions. The ``id`` parameter is a unique ID 5263 that will be used to reference this entropy backend from the 5264 ``virtio-rng`` device. By default, the ``virtio-rng`` device 5265 uses this RNG backend. 5266 5267 ``-object rng-random,id=id,filename=/dev/random`` 5268 Creates a random number generator backend which obtains entropy 5269 from a device on the host. The ``id`` parameter is a unique ID 5270 that will be used to reference this entropy backend from the 5271 ``virtio-rng`` device. The ``filename`` parameter specifies 5272 which file to obtain entropy from and if omitted defaults to 5273 ``/dev/urandom``. 5274 5275 ``-object rng-egd,id=id,chardev=chardevid`` 5276 Creates a random number generator backend which obtains entropy 5277 from an external daemon running on the host. The ``id`` 5278 parameter is a unique ID that will be used to reference this 5279 entropy backend from the ``virtio-rng`` device. The ``chardev`` 5280 parameter is the unique ID of a character device backend that 5281 provides the connection to the RNG daemon. 5282 5283 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off`` 5284 Creates a TLS anonymous credentials object, which can be used to 5285 provide TLS support on network backends. The ``id`` parameter is 5286 a unique ID which network backends will use to access the 5287 credentials. The ``endpoint`` is either ``server`` or ``client`` 5288 depending on whether the QEMU network backend that uses the 5289 credentials will be acting as a client or as a server. If 5290 ``verify-peer`` is enabled (the default) then once the handshake 5291 is completed, the peer credentials will be verified, though this 5292 is a no-op for anonymous credentials. 5293 5294 The dir parameter tells QEMU where to find the credential files. 5295 For server endpoints, this directory may contain a file 5296 dh-params.pem providing diffie-hellman parameters to use for the 5297 TLS server. If the file is missing, QEMU will generate a set of 5298 DH parameters at startup. This is a computationally expensive 5299 operation that consumes random pool entropy, so it is 5300 recommended that a persistent set of parameters be generated 5301 upfront and saved. 5302 5303 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]`` 5304 Creates a TLS Pre-Shared Keys (PSK) credentials object, which 5305 can be used to provide TLS support on network backends. The 5306 ``id`` parameter is a unique ID which network backends will use 5307 to access the credentials. The ``endpoint`` is either ``server`` 5308 or ``client`` depending on whether the QEMU network backend that 5309 uses the credentials will be acting as a client or as a server. 5310 For clients only, ``username`` is the username which will be 5311 sent to the server. If omitted it defaults to "qemu". 5312 5313 The dir parameter tells QEMU where to find the keys file. It is 5314 called "dir/keys.psk" and contains "username:key" pairs. This 5315 file can most easily be created using the GnuTLS ``psktool`` 5316 program. 5317 5318 For server endpoints, dir may also contain a file dh-params.pem 5319 providing diffie-hellman parameters to use for the TLS server. 5320 If the file is missing, QEMU will generate a set of DH 5321 parameters at startup. This is a computationally expensive 5322 operation that consumes random pool entropy, so it is 5323 recommended that a persistent set of parameters be generated up 5324 front and saved. 5325 5326 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id`` 5327 Creates a TLS anonymous credentials object, which can be used to 5328 provide TLS support on network backends. The ``id`` parameter is 5329 a unique ID which network backends will use to access the 5330 credentials. The ``endpoint`` is either ``server`` or ``client`` 5331 depending on whether the QEMU network backend that uses the 5332 credentials will be acting as a client or as a server. If 5333 ``verify-peer`` is enabled (the default) then once the handshake 5334 is completed, the peer credentials will be verified. With x509 5335 certificates, this implies that the clients must be provided 5336 with valid client certificates too. 5337 5338 The dir parameter tells QEMU where to find the credential files. 5339 For server endpoints, this directory may contain a file 5340 dh-params.pem providing diffie-hellman parameters to use for the 5341 TLS server. If the file is missing, QEMU will generate a set of 5342 DH parameters at startup. This is a computationally expensive 5343 operation that consumes random pool entropy, so it is 5344 recommended that a persistent set of parameters be generated 5345 upfront and saved. 5346 5347 For x509 certificate credentials the directory will contain 5348 further files providing the x509 certificates. The certificates 5349 must be stored in PEM format, in filenames ca-cert.pem, 5350 ca-crl.pem (optional), server-cert.pem (only servers), 5351 server-key.pem (only servers), client-cert.pem (only clients), 5352 and client-key.pem (only clients). 5353 5354 For the server-key.pem and client-key.pem files which contain 5355 sensitive private keys, it is possible to use an encrypted 5356 version by providing the passwordid parameter. This provides the 5357 ID of a previously created ``secret`` object containing the 5358 password for decryption. 5359 5360 The priority parameter allows to override the global default 5361 priority used by gnutls. This can be useful if the system 5362 administrator needs to use a weaker set of crypto priorities for 5363 QEMU without potentially forcing the weakness onto all 5364 applications. Or conversely if one wants wants a stronger 5365 default for QEMU than for all other applications, they can do 5366 this through this parameter. Its format is a gnutls priority 5367 string as described at 5368 https://gnutls.org/manual/html_node/Priority-Strings.html. 5369 5370 ``-object tls-cipher-suites,id=id,priority=priority`` 5371 Creates a TLS cipher suites object, which can be used to control 5372 the TLS cipher/protocol algorithms that applications are permitted 5373 to use. 5374 5375 The ``id`` parameter is a unique ID which frontends will use to 5376 access the ordered list of permitted TLS cipher suites from the 5377 host. 5378 5379 The ``priority`` parameter allows to override the global default 5380 priority used by gnutls. This can be useful if the system 5381 administrator needs to use a weaker set of crypto priorities for 5382 QEMU without potentially forcing the weakness onto all 5383 applications. Or conversely if one wants wants a stronger 5384 default for QEMU than for all other applications, they can do 5385 this through this parameter. Its format is a gnutls priority 5386 string as described at 5387 https://gnutls.org/manual/html_node/Priority-Strings.html. 5388 5389 An example of use of this object is to control UEFI HTTPS Boot. 5390 The tls-cipher-suites object exposes the ordered list of permitted 5391 TLS cipher suites from the host side to the guest firmware, via 5392 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER 5393 objects. The firmware uses the IANA_TLS_CIPHER array for configuring 5394 guest-side TLS. 5395 5396 In the following example, the priority at which the host-side policy 5397 is retrieved is given by the ``priority`` property. 5398 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to 5399 refer to /etc/crypto-policies/back-ends/gnutls.config. 5400 5401 .. parsed-literal:: 5402 5403 # |qemu_system| \\ 5404 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\ 5405 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 5406 5407 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` 5408 Interval t can't be 0, this filter batches the packet delivery: 5409 all packets arriving in a given interval on netdev netdevid are 5410 delayed until the end of the interval. Interval is in 5411 microseconds. ``status`` is optional that indicate whether the 5412 netfilter is on (enabled) or off (disabled), the default status 5413 for netfilter will be 'on'. 5414 5415 queue all\|rx\|tx is an option that can be applied to any 5416 netfilter. 5417 5418 ``all``: the filter is attached both to the receive and the 5419 transmit queue of the netdev (default). 5420 5421 ``rx``: the filter is attached to the receive queue of the 5422 netdev, where it will receive packets sent to the netdev. 5423 5424 ``tx``: the filter is attached to the transmit queue of the 5425 netdev, where it will receive packets sent by the netdev. 5426 5427 position head\|tail\|id=<id> is an option to specify where the 5428 filter should be inserted in the filter list. It can be applied 5429 to any netfilter. 5430 5431 ``head``: the filter is inserted at the head of the filter list, 5432 before any existing filters. 5433 5434 ``tail``: the filter is inserted at the tail of the filter list, 5435 behind any existing filters (default). 5436 5437 ``id=<id>``: the filter is inserted before or behind the filter 5438 specified by <id>, see the insert option below. 5439 5440 insert behind\|before is an option to specify where to insert 5441 the new filter relative to the one specified with 5442 position=id=<id>. It can be applied to any netfilter. 5443 5444 ``before``: insert before the specified filter. 5445 5446 ``behind``: insert behind the specified filter (default). 5447 5448 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5449 filter-mirror on netdev netdevid,mirror net packet to 5450 chardevchardevid, if it has the vnet\_hdr\_support flag, 5451 filter-mirror will mirror packet with vnet\_hdr\_len. 5452 5453 ``-object filter-redirector,id=id,netdev=netdevid,indev=chardevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5454 filter-redirector on netdev netdevid,redirect filter's net 5455 packet to chardev chardevid,and redirect indev's packet to 5456 filter.if it has the vnet\_hdr\_support flag, filter-redirector 5457 will redirect packet with vnet\_hdr\_len. Create a 5458 filter-redirector we need to differ outdev id from indev id, id 5459 can not be the same. we can just use indev or outdev, but at 5460 least one of indev or outdev need to be specified. 5461 5462 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]`` 5463 Filter-rewriter is a part of COLO project.It will rewrite tcp 5464 packet to secondary from primary to keep secondary tcp 5465 connection,and rewrite tcp packet to primary from secondary make 5466 tcp packet can be handled by client.if it has the 5467 vnet\_hdr\_support flag, we can parse packet with vnet header. 5468 5469 usage: colo secondary: -object 5470 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object 5471 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object 5472 filter-rewriter,id=rew0,netdev=hn0,queue=all 5473 5474 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]`` 5475 Dump the network traffic on netdev dev to the file specified by 5476 filename. At most len bytes (64k by default) per packet are 5477 stored. The file format is libpcap, so it can be analyzed with 5478 tools such as tcpdump or Wireshark. 5479 5480 ``-object colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]`` 5481 Colo-compare gets packet from primary\_in chardevid and 5482 secondary\_in, then compare whether the payload of primary packet 5483 and secondary packet are the same. If same, it will output 5484 primary packet to out\_dev, else it will notify COLO-framework to do 5485 checkpoint and send primary packet to out\_dev. In order to 5486 improve efficiency, we need to put the task of comparison in 5487 another iothread. If it has the vnet\_hdr\_support flag, 5488 colo compare will send/recv packet with vnet\_hdr\_len. 5489 The compare\_timeout=@var{ms} determines the maximum time of the 5490 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms} 5491 is to set the period of scanning expired primary node network packets. 5492 The max\_queue\_size=@var{size} is to set the max compare queue 5493 size depend on user environment. 5494 If user want to use Xen COLO, need to add the notify\_dev to 5495 notify Xen colo-frame to do checkpoint. 5496 5497 COLO-compare must be used with the help of filter-mirror, 5498 filter-redirector and filter-rewriter. 5499 5500 :: 5501 5502 KVM COLO 5503 5504 primary: 5505 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5506 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5507 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5508 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5509 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5510 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5511 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5512 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5513 -object iothread,id=iothread1 5514 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5515 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5516 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5517 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 5518 5519 secondary: 5520 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5521 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5522 -chardev socket,id=red0,host=3.3.3.3,port=9003 5523 -chardev socket,id=red1,host=3.3.3.3,port=9004 5524 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5525 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5526 5527 5528 Xen COLO 5529 5530 primary: 5531 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 5532 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 5533 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off 5534 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off 5535 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off 5536 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001 5537 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off 5538 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005 5539 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off 5540 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 5541 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 5542 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 5543 -object iothread,id=iothread1 5544 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 5545 5546 secondary: 5547 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 5548 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66 5549 -chardev socket,id=red0,host=3.3.3.3,port=9003 5550 -chardev socket,id=red1,host=3.3.3.3,port=9004 5551 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 5552 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 5553 5554 If you want to know the detail of above command line, you can 5555 read the colo-compare git log. 5556 5557 ``-object cryptodev-backend-builtin,id=id[,queues=queues]`` 5558 Creates a cryptodev backend which executes crypto operations from 5559 the QEMU cipher APIs. The id parameter is a unique ID that will 5560 be used to reference this cryptodev backend from the 5561 ``virtio-crypto`` device. The queues parameter is optional, 5562 which specify the queue number of cryptodev backend, the default 5563 of queues is 1. 5564 5565 .. parsed-literal:: 5566 5567 # |qemu_system| \\ 5568 [...] \\ 5569 -object cryptodev-backend-builtin,id=cryptodev0 \\ 5570 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5571 [...] 5572 5573 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]`` 5574 Creates a vhost-user cryptodev backend, backed by a chardev 5575 chardevid. The id parameter is a unique ID that will be used to 5576 reference this cryptodev backend from the ``virtio-crypto`` 5577 device. The chardev should be a unix domain socket backed one. 5578 The vhost-user uses a specifically defined protocol to pass 5579 vhost ioctl replacement messages to an application on the other 5580 end of the socket. The queues parameter is optional, which 5581 specify the queue number of cryptodev backend for multiqueue 5582 vhost-user, the default of queues is 1. 5583 5584 .. parsed-literal:: 5585 5586 # |qemu_system| \\ 5587 [...] \\ 5588 -chardev socket,id=chardev0,path=/path/to/socket \\ 5589 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\ 5590 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\ 5591 [...] 5592 5593 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]`` 5594 \ 5595 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]`` 5596 Defines a secret to store a password, encryption key, or some 5597 other sensitive data. The sensitive data can either be passed 5598 directly via the data parameter, or indirectly via the file 5599 parameter. Using the data parameter is insecure unless the 5600 sensitive data is encrypted. 5601 5602 The sensitive data can be provided in raw format (the default), 5603 or base64. When encoded as JSON, the raw format only supports 5604 valid UTF-8 characters, so base64 is recommended for sending 5605 binary data. QEMU will convert from which ever format is 5606 provided to the format it needs internally. eg, an RBD password 5607 can be provided in raw format, even though it will be base64 5608 encoded when passed onto the RBD sever. 5609 5610 For added protection, it is possible to encrypt the data 5611 associated with a secret using the AES-256-CBC cipher. Use of 5612 encryption is indicated by providing the keyid and iv 5613 parameters. The keyid parameter provides the ID of a previously 5614 defined secret that contains the AES-256 decryption key. This 5615 key should be 32-bytes long and be base64 encoded. The iv 5616 parameter provides the random initialization vector used for 5617 encryption of this particular secret and should be a base64 5618 encrypted string of the 16-byte IV. 5619 5620 The simplest (insecure) usage is to provide the secret inline 5621 5622 .. parsed-literal:: 5623 5624 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw 5625 5626 The simplest secure usage is to provide the secret via a file 5627 5628 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object 5629 secret,id=sec0,file=mypasswd.txt,format=raw 5630 5631 For greater security, AES-256-CBC should be used. To illustrate 5632 usage, consider the openssl command line tool which can encrypt 5633 the data. Note that when encrypting, the plaintext must be 5634 padded to the cipher block size (32 bytes) using the standard 5635 PKCS#5/6 compatible padding algorithm. 5636 5637 First a master key needs to be created in base64 encoding: 5638 5639 :: 5640 5641 # openssl rand -base64 32 > key.b64 5642 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 5643 5644 Each secret to be encrypted needs to have a random 5645 initialization vector generated. These do not need to be kept 5646 secret 5647 5648 :: 5649 5650 # openssl rand -base64 16 > iv.b64 5651 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 5652 5653 The secret to be defined can now be encrypted, in this case 5654 we're telling openssl to base64 encode the result, but it could 5655 be left as raw bytes if desired. 5656 5657 :: 5658 5659 # SECRET=$(printf "letmein" | 5660 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 5661 5662 When launching QEMU, create a master secret pointing to 5663 ``key.b64`` and specify that to be used to decrypt the user 5664 password. Pass the contents of ``iv.b64`` to the second secret 5665 5666 .. parsed-literal:: 5667 5668 # |qemu_system| \\ 5669 -object secret,id=secmaster0,format=base64,file=key.b64 \\ 5670 -object secret,id=sec0,keyid=secmaster0,format=base64,\\ 5671 data=$SECRET,iv=$(<iv.b64) 5672 5673 ``-object sev-guest,id=id,cbitpos=cbitpos,reduced-phys-bits=val,[sev-device=string,policy=policy,handle=handle,dh-cert-file=file,session-file=file,kernel-hashes=on|off]`` 5674 Create a Secure Encrypted Virtualization (SEV) guest object, 5675 which can be used to provide the guest memory encryption support 5676 on AMD processors. 5677 5678 When memory encryption is enabled, one of the physical address 5679 bit (aka the C-bit) is utilized to mark if a memory page is 5680 protected. The ``cbitpos`` is used to provide the C-bit 5681 position. The C-bit position is Host family dependent hence user 5682 must provide this value. On EPYC, the value should be 47. 5683 5684 When memory encryption is enabled, we loose certain bits in 5685 physical address space. The ``reduced-phys-bits`` is used to 5686 provide the number of bits we loose in physical address space. 5687 Similar to C-bit, the value is Host family dependent. On EPYC, 5688 a guest will lose a maximum of 1 bit, so the value should be 1. 5689 5690 The ``sev-device`` provides the device file to use for 5691 communicating with the SEV firmware running inside AMD Secure 5692 Processor. The default device is '/dev/sev'. If hardware 5693 supports memory encryption then /dev/sev devices are created by 5694 CCP driver. 5695 5696 The ``policy`` provides the guest policy to be enforced by the 5697 SEV firmware and restrict what configuration and operational 5698 commands can be performed on this guest by the hypervisor. The 5699 policy should be provided by the guest owner and is bound to the 5700 guest and cannot be changed throughout the lifetime of the 5701 guest. The default is 0. 5702 5703 If guest ``policy`` allows sharing the key with another SEV 5704 guest then ``handle`` can be use to provide handle of the guest 5705 from which to share the key. 5706 5707 The ``dh-cert-file`` and ``session-file`` provides the guest 5708 owner's Public Diffie-Hillman key defined in SEV spec. The PDH 5709 and session parameters are used for establishing a cryptographic 5710 session with the guest owner to negotiate keys used for 5711 attestation. The file must be encoded in base64. 5712 5713 The ``kernel-hashes`` adds the hashes of given kernel/initrd/ 5714 cmdline to a designated guest firmware page for measured Linux 5715 boot with -kernel. The default is off. (Since 6.2) 5716 5717 e.g to launch a SEV guest 5718 5719 .. parsed-literal:: 5720 5721 # |qemu_system_x86| \\ 5722 ...... \\ 5723 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\ 5724 -machine ...,memory-encryption=sev0 \\ 5725 ..... 5726 5727 ``-object authz-simple,id=id,identity=string`` 5728 Create an authorization object that will control access to 5729 network services. 5730 5731 The ``identity`` parameter is identifies the user and its format 5732 depends on the network service that authorization object is 5733 associated with. For authorizing based on TLS x509 certificates, 5734 the identity must be the x509 distinguished name. Note that care 5735 must be taken to escape any commas in the distinguished name. 5736 5737 An example authorization object to validate a x509 distinguished 5738 name would look like: 5739 5740 .. parsed-literal:: 5741 5742 # |qemu_system| \\ 5743 ... \\ 5744 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\ 5745 ... 5746 5747 Note the use of quotes due to the x509 distinguished name 5748 containing whitespace, and escaping of ','. 5749 5750 ``-object authz-listfile,id=id,filename=path,refresh=on|off`` 5751 Create an authorization object that will control access to 5752 network services. 5753 5754 The ``filename`` parameter is the fully qualified path to a file 5755 containing the access control list rules in JSON format. 5756 5757 An example set of rules that match against SASL usernames might 5758 look like: 5759 5760 :: 5761 5762 { 5763 "rules": [ 5764 { "match": "fred", "policy": "allow", "format": "exact" }, 5765 { "match": "bob", "policy": "allow", "format": "exact" }, 5766 { "match": "danb", "policy": "deny", "format": "glob" }, 5767 { "match": "dan*", "policy": "allow", "format": "exact" }, 5768 ], 5769 "policy": "deny" 5770 } 5771 5772 When checking access the object will iterate over all the rules 5773 and the first rule to match will have its ``policy`` value 5774 returned as the result. If no rules match, then the default 5775 ``policy`` value is returned. 5776 5777 The rules can either be an exact string match, or they can use 5778 the simple UNIX glob pattern matching to allow wildcards to be 5779 used. 5780 5781 If ``refresh`` is set to true the file will be monitored and 5782 automatically reloaded whenever its content changes. 5783 5784 As with the ``authz-simple`` object, the format of the identity 5785 strings being matched depends on the network service, but is 5786 usually a TLS x509 distinguished name, or a SASL username. 5787 5788 An example authorization object to validate a SASL username 5789 would look like: 5790 5791 .. parsed-literal:: 5792 5793 # |qemu_system| \\ 5794 ... \\ 5795 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\ 5796 ... 5797 5798 ``-object authz-pam,id=id,service=string`` 5799 Create an authorization object that will control access to 5800 network services. 5801 5802 The ``service`` parameter provides the name of a PAM service to 5803 use for authorization. It requires that a file 5804 ``/etc/pam.d/service`` exist to provide the configuration for 5805 the ``account`` subsystem. 5806 5807 An example authorization object to validate a TLS x509 5808 distinguished name would look like: 5809 5810 .. parsed-literal:: 5811 5812 # |qemu_system| \\ 5813 ... \\ 5814 -object authz-pam,id=auth0,service=qemu-vnc \\ 5815 ... 5816 5817 There would then be a corresponding config file for PAM at 5818 ``/etc/pam.d/qemu-vnc`` that contains: 5819 5820 :: 5821 5822 account requisite pam_listfile.so item=user sense=allow \ 5823 file=/etc/qemu/vnc.allow 5824 5825 Finally the ``/etc/qemu/vnc.allow`` file would contain the list 5826 of x509 distinguished names that are permitted access 5827 5828 :: 5829 5830 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 5831 5832 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch`` 5833 Creates a dedicated event loop thread that devices can be 5834 assigned to. This is known as an IOThread. By default device 5835 emulation happens in vCPU threads or the main event loop thread. 5836 This can become a scalability bottleneck. IOThreads allow device 5837 emulation and I/O to run on other host CPUs. 5838 5839 The ``id`` parameter is a unique ID that will be used to 5840 reference this IOThread from ``-device ...,iothread=id``. 5841 Multiple devices can be assigned to an IOThread. Note that not 5842 all devices support an ``iothread`` parameter. 5843 5844 The ``query-iothreads`` QMP command lists IOThreads and reports 5845 their thread IDs so that the user can configure host CPU 5846 pinning/affinity. 5847 5848 IOThreads use an adaptive polling algorithm to reduce event loop 5849 latency. Instead of entering a blocking system call to monitor 5850 file descriptors and then pay the cost of being woken up when an 5851 event occurs, the polling algorithm spins waiting for events for 5852 a short time. The algorithm's default parameters are suitable 5853 for many cases but can be adjusted based on knowledge of the 5854 workload and/or host device latency. 5855 5856 The ``poll-max-ns`` parameter is the maximum number of 5857 nanoseconds to busy wait for events. Polling can be disabled by 5858 setting this value to 0. 5859 5860 The ``poll-grow`` parameter is the multiplier used to increase 5861 the polling time when the algorithm detects it is missing events 5862 due to not polling long enough. 5863 5864 The ``poll-shrink`` parameter is the divisor used to decrease 5865 the polling time when the algorithm detects it is spending too 5866 long polling without encountering events. 5867 5868 The ``aio-max-batch`` parameter is the maximum number of requests 5869 in a batch for the AIO engine, 0 means that the engine will use 5870 its default. 5871 5872 The IOThread parameters can be modified at run-time using the 5873 ``qom-set`` command (where ``iothread1`` is the IOThread's 5874 ``id``): 5875 5876 :: 5877 5878 (qemu) qom-set /objects/iothread1 poll-max-ns 100000 5879ERST 5880 5881 5882HXCOMM This is the last statement. Insert new options before this line! 5883 5884#undef DEF 5885#undef DEFHEADING 5886#undef ARCHHEADING 5887
