1HXCOMM Use DEFHEADING() to define headings in both help text and texi 2HXCOMM Text between STEXI and ETEXI are copied to texi version and 3HXCOMM discarded from C version 4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to 5HXCOMM construct option structures, enums and help message for specified 6HXCOMM architectures. 7HXCOMM HXCOMM can be used for comments, discarded from both texi and C 8 9DEFHEADING(Standard options) 10STEXI 11@table @option 12ETEXI 13 14DEF("help", 0, QEMU_OPTION_h, 15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 16STEXI 17@item -h 18@findex -h 19Display help and exit 20ETEXI 21 22DEF("version", 0, QEMU_OPTION_version, 23 "-version display version information and exit\n", QEMU_ARCH_ALL) 24STEXI 25@item -version 26@findex -version 27Display version information and exit 28ETEXI 29 30DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 31 "-machine [type=]name[,prop[=value][,...]]\n" 32 " selects emulated machine ('-machine help' for list)\n" 33 " property accel=accel1[:accel2[:...]] selects accelerator\n" 34 " supported accelerators are kvm, xen, hax or tcg (default: tcg)\n" 35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" 36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n" 38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 39 " mem-merge=on|off controls memory merge support (default: on)\n" 40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 44 " nvdimm=on|off controls NVDIMM support (default=off)\n" 45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 46 " s390-squash-mcss=on|off controls support for squashing into default css (default=off)\n", 47 QEMU_ARCH_ALL) 48STEXI 49@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 50@findex -machine 51Select the emulated machine by @var{name}. Use @code{-machine help} to list 52available machines. 53 54For architectures which aim to support live migration compatibility 55across releases, each release will introduce a new versioned machine 56type. For example, the 2.8.0 release introduced machine types 57``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. 58 59To allow live migration of guests from QEMU version 2.8.0, to QEMU 60version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' 61and ``pc-q35-2.8'' machines too. To allow users live migrating VMs 62to skip multiple intermediate releases when upgrading, new releases 63of QEMU will support machine types from many previous versions. 64 65Supported machine properties are: 66@table @option 67@item accel=@var{accels1}[:@var{accels2}[:...]] 68This is used to enable an accelerator. Depending on the target architecture, 69kvm, xen, hax or tcg can be available. By default, tcg is used. If there is 70more than one accelerator specified, the next one is used if the previous one 71fails to initialize. 72@item kernel_irqchip=on|off 73Controls in-kernel irqchip support for the chosen accelerator when available. 74@item gfx_passthru=on|off 75Enables IGD GFX passthrough support for the chosen machine when available. 76@item vmport=on|off|auto 77Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 78value based on accel. For accel=xen the default is off otherwise the default 79is on. 80@item kvm_shadow_mem=size 81Defines the size of the KVM shadow MMU. 82@item dump-guest-core=on|off 83Include guest memory in a core dump. The default is on. 84@item mem-merge=on|off 85Enables or disables memory merge support. This feature, when supported by 86the host, de-duplicates identical memory pages among VMs instances 87(enabled by default). 88@item aes-key-wrap=on|off 89Enables or disables AES key wrapping support on s390-ccw hosts. This feature 90controls whether AES wrapping keys will be created to allow 91execution of AES cryptographic functions. The default is on. 92@item dea-key-wrap=on|off 93Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 94controls whether DEA wrapping keys will be created to allow 95execution of DEA cryptographic functions. The default is on. 96@item nvdimm=on|off 97Enables or disables NVDIMM support. The default is off. 98@item s390-squash-mcss=on|off 99Enables or disables squashing subchannels into the default css. 100The default is off. 101@item enforce-config-section=on|off 102If @option{enforce-config-section} is set to @var{on}, force migration 103code to send configuration section even if the machine-type sets the 104@option{migration.send-configuration} property to @var{off}. 105NOTE: this parameter is deprecated. Please use @option{-global} 106@option{migration.send-configuration}=@var{on|off} instead. 107@end table 108ETEXI 109 110HXCOMM Deprecated by -machine 111DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 112 113DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 114 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 115STEXI 116@item -cpu @var{model} 117@findex -cpu 118Select CPU model (@code{-cpu help} for list and additional feature selection) 119ETEXI 120 121DEF("accel", HAS_ARG, QEMU_OPTION_accel, 122 "-accel [accel=]accelerator[,thread=single|multi]\n" 123 " select accelerator (kvm, xen, hax or tcg; use 'help' for a list)\n" 124 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 125STEXI 126@item -accel @var{name}[,prop=@var{value}[,...]] 127@findex -accel 128This is used to enable an accelerator. Depending on the target architecture, 129kvm, xen, hax or tcg can be available. By default, tcg is used. If there is 130more than one accelerator specified, the next one is used if the previous one 131fails to initialize. 132@table @option 133@item thread=single|multi 134Controls number of TCG threads. When the TCG is multi-threaded there will be one 135thread per vCPU therefor taking advantage of additional host cores. The default 136is to enable multi-threading where both the back-end and front-ends support it and 137no incompatible TCG features have been enabled (e.g. icount/replay). 138@end table 139ETEXI 140 141DEF("smp", HAS_ARG, QEMU_OPTION_smp, 142 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 143 " set the number of CPUs to 'n' [default=1]\n" 144 " maxcpus= maximum number of total cpus, including\n" 145 " offline CPUs for hotplug, etc\n" 146 " cores= number of CPU cores on one socket\n" 147 " threads= number of threads on one CPU core\n" 148 " sockets= number of discrete sockets in the system\n", 149 QEMU_ARCH_ALL) 150STEXI 151@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 152@findex -smp 153Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 154CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 155to 4. 156For the PC target, the number of @var{cores} per socket, the number 157of @var{threads} per cores and the total number of @var{sockets} can be 158specified. Missing values will be computed. If any on the three values is 159given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 160specifies the maximum number of hotpluggable CPUs. 161ETEXI 162 163DEF("numa", HAS_ARG, QEMU_OPTION_numa, 164 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 165 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 166 "-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL) 167STEXI 168@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 169@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 170@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 171@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 172@findex -numa 173Define a NUMA node and assign RAM and VCPUs to it. 174Set the NUMA distance from a source node to a destination node. 175 176Legacy VCPU assignment uses @samp{cpus} option where 177@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 178@samp{cpus} option represent a contiguous range of CPU indexes 179(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 180set of VCPUs can be represented by providing multiple @samp{cpus} 181options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 182split between them. 183 184For example, the following option assigns VCPUs 0, 1, 2 and 5 to 185a NUMA node: 186@example 187-numa node,cpus=0-2,cpus=5 188@end example 189 190@samp{cpu} option is a new alternative to @samp{cpus} option 191which uses @samp{socket-id|core-id|thread-id} properties to assign 192CPU objects to a @var{node} using topology layout properties of CPU. 193The set of properties is machine specific, and depends on used 194machine type/@samp{smp} options. It could be queried with 195@samp{hotpluggable-cpus} monitor command. 196@samp{node-id} property specifies @var{node} to which CPU object 197will be assigned, it's required for @var{node} to be declared 198with @samp{node} option before it's used with @samp{cpu} option. 199 200For example: 201@example 202-M pc \ 203-smp 1,sockets=2,maxcpus=2 \ 204-numa node,nodeid=0 -numa node,nodeid=1 \ 205-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 206@end example 207 208@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 209assigns RAM from a given memory backend device to a node. If 210@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 211split equally between them. 212 213@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 214if one node uses @samp{memdev}, all of them have to use it. 215 216@var{source} and @var{destination} are NUMA node IDs. 217@var{distance} is the NUMA distance from @var{source} to @var{destination}. 218The distance from a node to itself is always 10. If any pair of nodes is 219given a distance, then all pairs must be given distances. Although, when 220distances are only given in one direction for each pair of nodes, then 221the distances in the opposite directions are assumed to be the same. If, 222however, an asymmetrical pair of distances is given for even one node 223pair, then all node pairs must be provided distance values for both 224directions, even when they are symmetrical. When a node is unreachable 225from another node, set the pair's distance to 255. 226 227Note that the -@option{numa} option doesn't allocate any of the 228specified resources, it just assigns existing resources to NUMA 229nodes. This means that one still has to use the @option{-m}, 230@option{-smp} options to allocate RAM and VCPUs respectively. 231 232ETEXI 233 234DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 235 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 236 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 237STEXI 238@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 239@findex -add-fd 240 241Add a file descriptor to an fd set. Valid options are: 242 243@table @option 244@item fd=@var{fd} 245This option defines the file descriptor of which a duplicate is added to fd set. 246The file descriptor cannot be stdin, stdout, or stderr. 247@item set=@var{set} 248This option defines the ID of the fd set to add the file descriptor to. 249@item opaque=@var{opaque} 250This option defines a free-form string that can be used to describe @var{fd}. 251@end table 252 253You can open an image using pre-opened file descriptors from an fd set: 254@example 255qemu-system-i386 256-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 257-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 258-drive file=/dev/fdset/2,index=0,media=disk 259@end example 260ETEXI 261 262DEF("set", HAS_ARG, QEMU_OPTION_set, 263 "-set group.id.arg=value\n" 264 " set <arg> parameter for item <id> of type <group>\n" 265 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 266STEXI 267@item -set @var{group}.@var{id}.@var{arg}=@var{value} 268@findex -set 269Set parameter @var{arg} for item @var{id} of type @var{group} 270ETEXI 271 272DEF("global", HAS_ARG, QEMU_OPTION_global, 273 "-global driver.property=value\n" 274 "-global driver=driver,property=property,value=value\n" 275 " set a global default for a driver property\n", 276 QEMU_ARCH_ALL) 277STEXI 278@item -global @var{driver}.@var{prop}=@var{value} 279@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 280@findex -global 281Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 282 283@example 284qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img 285@end example 286 287In particular, you can use this to set driver properties for devices which are 288created automatically by the machine model. To create a device which is not 289created automatically and set properties on it, use -@option{device}. 290 291-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 292driver=@var{driver},property=@var{prop},value=@var{value}. The 293longhand syntax works even when @var{driver} contains a dot. 294ETEXI 295 296DEF("boot", HAS_ARG, QEMU_OPTION_boot, 297 "-boot [order=drives][,once=drives][,menu=on|off]\n" 298 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 299 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 300 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 301 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 302 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 303 QEMU_ARCH_ALL) 304STEXI 305@item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off] 306@findex -boot 307Specify boot order @var{drives} as a string of drive letters. Valid 308drive letters depend on the target architecture. The x86 PC uses: a, b 309(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 310from network adapter 1-4), hard disk boot is the default. To apply a 311particular boot order only on the first startup, specify it via 312@option{once}. Note that the @option{order} or @option{once} parameter 313should not be used together with the @option{bootindex} property of 314devices, since the firmware implementations normally do not support both 315at the same time. 316 317Interactive boot menus/prompts can be enabled via @option{menu=on} as far 318as firmware/BIOS supports them. The default is non-interactive boot. 319 320A splash picture could be passed to bios, enabling user to show it as logo, 321when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 322supports them. Currently Seabios for X86 system support it. 323limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 324format(true color). The resolution should be supported by the SVGA mode, so 325the recommended is 320x240, 640x480, 800x640. 326 327A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 328when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 329reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 330system support it. 331 332Do strict boot via @option{strict=on} as far as firmware/BIOS 333supports it. This only effects when boot priority is changed by 334bootindex options. The default is non-strict boot. 335 336@example 337# try to boot from network first, then from hard disk 338qemu-system-i386 -boot order=nc 339# boot from CD-ROM first, switch back to default order after reboot 340qemu-system-i386 -boot once=d 341# boot with a splash picture for 5 seconds. 342qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 343@end example 344 345Note: The legacy format '-boot @var{drives}' is still supported but its 346use is discouraged as it may be removed from future versions. 347ETEXI 348 349DEF("m", HAS_ARG, QEMU_OPTION_m, 350 "-m [size=]megs[,slots=n,maxmem=size]\n" 351 " configure guest RAM\n" 352 " size: initial amount of guest memory\n" 353 " slots: number of hotplug slots (default: none)\n" 354 " maxmem: maximum amount of guest memory (default: none)\n" 355 "NOTE: Some architectures might enforce a specific granularity\n", 356 QEMU_ARCH_ALL) 357STEXI 358@item -m [size=]@var{megs}[,slots=n,maxmem=size] 359@findex -m 360Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 361Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 362megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 363could be used to set amount of hotpluggable memory slots and maximum amount of 364memory. Note that @var{maxmem} must be aligned to the page size. 365 366For example, the following command-line sets the guest startup RAM size to 3671GB, creates 3 slots to hotplug additional memory and sets the maximum 368memory the guest can reach to 4GB: 369 370@example 371qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 372@end example 373 374If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 375be enabled and the guest startup RAM will never increase. 376ETEXI 377 378DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 379 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 380STEXI 381@item -mem-path @var{path} 382@findex -mem-path 383Allocate guest RAM from a temporarily created file in @var{path}. 384ETEXI 385 386DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 387 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 388 QEMU_ARCH_ALL) 389STEXI 390@item -mem-prealloc 391@findex -mem-prealloc 392Preallocate memory when using -mem-path. 393ETEXI 394 395DEF("k", HAS_ARG, QEMU_OPTION_k, 396 "-k language use keyboard layout (for example 'fr' for French)\n", 397 QEMU_ARCH_ALL) 398STEXI 399@item -k @var{language} 400@findex -k 401Use keyboard layout @var{language} (for example @code{fr} for 402French). This option is only needed where it is not easy to get raw PC 403keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 404display). You don't normally need to use it on PC/Linux or PC/Windows 405hosts. 406 407The available layouts are: 408@example 409ar de-ch es fo fr-ca hu ja mk no pt-br sv 410da en-gb et fr fr-ch is lt nl pl ru th 411de en-us fi fr-be hr it lv nl-be pt sl tr 412@end example 413 414The default is @code{en-us}. 415ETEXI 416 417 418DEF("audio-help", 0, QEMU_OPTION_audio_help, 419 "-audio-help print list of audio drivers and their options\n", 420 QEMU_ARCH_ALL) 421STEXI 422@item -audio-help 423@findex -audio-help 424Will show the audio subsystem help: list of drivers, tunable 425parameters. 426ETEXI 427 428DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 429 "-soundhw c1,... enable audio support\n" 430 " and only specified sound cards (comma separated list)\n" 431 " use '-soundhw help' to get the list of supported cards\n" 432 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 433STEXI 434@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 435@findex -soundhw 436Enable audio and selected sound hardware. Use 'help' to print all 437available sound hardware. 438 439@example 440qemu-system-i386 -soundhw sb16,adlib disk.img 441qemu-system-i386 -soundhw es1370 disk.img 442qemu-system-i386 -soundhw ac97 disk.img 443qemu-system-i386 -soundhw hda disk.img 444qemu-system-i386 -soundhw all disk.img 445qemu-system-i386 -soundhw help 446@end example 447 448Note that Linux's i810_audio OSS kernel (for AC97) module might 449require manually specifying clocking. 450 451@example 452modprobe i810_audio clocking=48000 453@end example 454ETEXI 455 456DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 457 "-balloon none disable balloon device\n" 458 "-balloon virtio[,addr=str]\n" 459 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL) 460STEXI 461@item -balloon none 462@findex -balloon 463Disable balloon device. 464@item -balloon virtio[,addr=@var{addr}] 465Enable virtio balloon device (default), optionally with PCI address 466@var{addr}. 467ETEXI 468 469DEF("device", HAS_ARG, QEMU_OPTION_device, 470 "-device driver[,prop[=value][,...]]\n" 471 " add device (based on driver)\n" 472 " prop=value,... sets driver properties\n" 473 " use '-device help' to print all possible drivers\n" 474 " use '-device driver,help' to print all possible properties\n", 475 QEMU_ARCH_ALL) 476STEXI 477@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 478@findex -device 479Add device @var{driver}. @var{prop}=@var{value} sets driver 480properties. Valid properties depend on the driver. To get help on 481possible drivers and properties, use @code{-device help} and 482@code{-device @var{driver},help}. 483 484Some drivers are: 485@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}] 486 487Add an IPMI BMC. This is a simulation of a hardware management 488interface processor that normally sits on a system. It provides 489a watchdog and the ability to reset and power control the system. 490You need to connect this to an IPMI interface to make it useful 491 492The IPMI slave address to use for the BMC. The default is 0x20. 493This address is the BMC's address on the I2C network of management 494controllers. If you don't know what this means, it is safe to ignore 495it. 496 497@table @option 498@item bmc=@var{id} 499The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 500@item slave_addr=@var{val} 501Define slave address to use for the BMC. The default is 0x20. 502@item sdrfile=@var{file} 503file containing raw Sensor Data Records (SDR) data. The default is none. 504@item fruareasize=@var{val} 505size of a Field Replaceable Unit (FRU) area. The default is 1024. 506@item frudatafile=@var{file} 507file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 508@end table 509 510@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 511 512Add a connection to an external IPMI BMC simulator. Instead of 513locally emulating the BMC like the above item, instead connect 514to an external entity that provides the IPMI services. 515 516A connection is made to an external BMC simulator. If you do this, it 517is strongly recommended that you use the "reconnect=" chardev option 518to reconnect to the simulator if the connection is lost. Note that if 519this is not used carefully, it can be a security issue, as the 520interface has the ability to send resets, NMIs, and power off the VM. 521It's best if QEMU makes a connection to an external simulator running 522on a secure port on localhost, so neither the simulator nor QEMU is 523exposed to any outside network. 524 525See the "lanserv/README.vm" file in the OpenIPMI library for more 526details on the external interface. 527 528@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 529 530Add a KCS IPMI interafce on the ISA bus. This also adds a 531corresponding ACPI and SMBIOS entries, if appropriate. 532 533@table @option 534@item bmc=@var{id} 535The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 536@item ioport=@var{val} 537Define the I/O address of the interface. The default is 0xca0 for KCS. 538@item irq=@var{val} 539Define the interrupt to use. The default is 5. To disable interrupts, 540set this to 0. 541@end table 542 543@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 544 545Like the KCS interface, but defines a BT interface. The default port is 5460xe4 and the default interrupt is 5. 547 548ETEXI 549 550DEF("name", HAS_ARG, QEMU_OPTION_name, 551 "-name string1[,process=string2][,debug-threads=on|off]\n" 552 " set the name of the guest\n" 553 " string1 sets the window title and string2 the process name (on Linux)\n" 554 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 555 " NOTE: The thread names are for debugging and not a stable API.\n", 556 QEMU_ARCH_ALL) 557STEXI 558@item -name @var{name} 559@findex -name 560Sets the @var{name} of the guest. 561This name will be displayed in the SDL window caption. 562The @var{name} will also be used for the VNC server. 563Also optionally set the top visible process name in Linux. 564Naming of individual threads can also be enabled on Linux to aid debugging. 565ETEXI 566 567DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 568 "-uuid %08x-%04x-%04x-%04x-%012x\n" 569 " specify machine UUID\n", QEMU_ARCH_ALL) 570STEXI 571@item -uuid @var{uuid} 572@findex -uuid 573Set system UUID. 574ETEXI 575 576STEXI 577@end table 578ETEXI 579DEFHEADING() 580 581DEFHEADING(Block device options) 582STEXI 583@table @option 584ETEXI 585 586DEF("fda", HAS_ARG, QEMU_OPTION_fda, 587 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 588DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 589STEXI 590@item -fda @var{file} 591@itemx -fdb @var{file} 592@findex -fda 593@findex -fdb 594Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 595ETEXI 596 597DEF("hda", HAS_ARG, QEMU_OPTION_hda, 598 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 599DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 600DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 601 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 602DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 603STEXI 604@item -hda @var{file} 605@itemx -hdb @var{file} 606@itemx -hdc @var{file} 607@itemx -hdd @var{file} 608@findex -hda 609@findex -hdb 610@findex -hdc 611@findex -hdd 612Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 613ETEXI 614 615DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 616 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 617 QEMU_ARCH_ALL) 618STEXI 619@item -cdrom @var{file} 620@findex -cdrom 621Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 622@option{-cdrom} at the same time). You can use the host CD-ROM by 623using @file{/dev/cdrom} as filename (@pxref{host_drives}). 624ETEXI 625 626DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 627 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 628 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 629 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n" 630 " [,driver specific parameters...]\n" 631 " configure a block backend\n", QEMU_ARCH_ALL) 632STEXI 633@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 634@findex -blockdev 635 636Define a new block driver node. Some of the options apply to all block drivers, 637other options are only accepted for a specific block driver. See below for a 638list of generic options and options for the most common block drivers. 639 640Options that expect a reference to another node (e.g. @code{file}) can be 641given in two ways. Either you specify the node name of an already existing node 642(file=@var{node-name}), or you define a new node inline, adding options 643for the referenced node after a dot (file.filename=@var{path},file.aio=native). 644 645A block driver node created with @option{-blockdev} can be used for a guest 646device by specifying its node name for the @code{drive} property in a 647@option{-device} argument that defines a block device. 648 649@table @option 650@item Valid options for any block driver node: 651 652@table @code 653@item driver 654Specifies the block driver to use for the given node. 655@item node-name 656This defines the name of the block driver node by which it will be referenced 657later. The name must be unique, i.e. it must not match the name of a different 658block driver node, or (if you use @option{-drive} as well) the ID of a drive. 659 660If no node name is specified, it is automatically generated. The generated node 661name is not intended to be predictable and changes between QEMU invocations. 662For the top level, an explicit node name must be specified. 663@item read-only 664Open the node read-only. Guest write attempts will fail. 665@item cache.direct 666The host page cache can be avoided with @option{cache.direct=on}. This will 667attempt to do disk IO directly to the guest's memory. QEMU may still perform an 668internal copy of the data. 669@item cache.no-flush 670In case you don't care about data integrity over host failures, you can use 671@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 672any data to the disk but can instead keep things in cache. If anything goes 673wrong, like your host losing power, the disk storage getting disconnected 674accidentally, etc. your image will most probably be rendered unusable. 675@item discard=@var{discard} 676@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 677whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 678ignored or passed to the filesystem. Some machine types may not support 679discard requests. 680@item detect-zeroes=@var{detect-zeroes} 681@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 682conversion of plain zero writes by the OS to driver specific optimized 683zero write commands. You may even choose "unmap" if @var{discard} is set 684to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 685@end table 686 687@item Driver-specific options for @code{file} 688 689This is the protocol-level block driver for accessing regular files. 690 691@table @code 692@item filename 693The path to the image file in the local filesystem 694@item aio 695Specifies the AIO backend (threads/native, default: threads) 696@end table 697Example: 698@example 699-blockdev driver=file,node-name=disk,filename=disk.img 700@end example 701 702@item Driver-specific options for @code{raw} 703 704This is the image format block driver for raw images. It is usually 705stacked on top of a protocol level block driver such as @code{file}. 706 707@table @code 708@item file 709Reference to or definition of the data source block driver node 710(e.g. a @code{file} driver node) 711@end table 712Example 1: 713@example 714-blockdev driver=file,node-name=disk_file,filename=disk.img 715-blockdev driver=raw,node-name=disk,file=disk_file 716@end example 717Example 2: 718@example 719-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 720@end example 721 722@item Driver-specific options for @code{qcow2} 723 724This is the image format block driver for qcow2 images. It is usually 725stacked on top of a protocol level block driver such as @code{file}. 726 727@table @code 728@item file 729Reference to or definition of the data source block driver node 730(e.g. a @code{file} driver node) 731 732@item backing 733Reference to or definition of the backing file block device (default is taken 734from the image file). It is allowed to pass an empty string here in order to 735disable the default backing file. 736 737@item lazy-refcounts 738Whether to enable the lazy refcounts feature (on/off; default is taken from the 739image file) 740 741@item cache-size 742The maximum total size of the L2 table and refcount block caches in bytes 743(default: 1048576 bytes or 8 clusters, whichever is larger) 744 745@item l2-cache-size 746The maximum size of the L2 table cache in bytes 747(default: 4/5 of the total cache size) 748 749@item refcount-cache-size 750The maximum size of the refcount block cache in bytes 751(default: 1/5 of the total cache size) 752 753@item cache-clean-interval 754Clean unused entries in the L2 and refcount caches. The interval is in seconds. 755The default value is 0 and it disables this feature. 756 757@item pass-discard-request 758Whether discard requests to the qcow2 device should be forwarded to the data 759source (on/off; default: on if discard=unmap is specified, off otherwise) 760 761@item pass-discard-snapshot 762Whether discard requests for the data source should be issued when a snapshot 763operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 764default: on) 765 766@item pass-discard-other 767Whether discard requests for the data source should be issued on other 768occasions where a cluster gets freed (on/off; default: off) 769 770@item overlap-check 771Which overlap checks to perform for writes to the image 772(none/constant/cached/all; default: cached). For details or finer 773granularity control refer to the QAPI documentation of @code{blockdev-add}. 774@end table 775 776Example 1: 777@example 778-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 779-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 780@end example 781Example 2: 782@example 783-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 784@end example 785 786@item Driver-specific options for other drivers 787Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 788 789@end table 790 791ETEXI 792 793DEF("drive", HAS_ARG, QEMU_OPTION_drive, 794 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 795 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n" 796 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 797 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n" 798 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 799 " [,readonly=on|off][,copy-on-read=on|off]\n" 800 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 801 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 802 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 803 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 804 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 805 " [[,iops_size=is]]\n" 806 " [[,group=g]]\n" 807 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 808STEXI 809@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 810@findex -drive 811 812Define a new drive. This includes creating a block driver node (the backend) as 813well as a guest device, and is mostly a shortcut for defining the corresponding 814@option{-blockdev} and @option{-device} options. 815 816@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 817addition, it knows the following options: 818 819@table @option 820@item file=@var{file} 821This option defines which disk image (@pxref{disk_images}) to use with 822this drive. If the filename contains comma, you must double it 823(for instance, "file=my,,file" to use file "my,file"). 824 825Special files such as iSCSI devices can be specified using protocol 826specific URLs. See the section for "Device URL Syntax" for more information. 827@item if=@var{interface} 828This option defines on which type on interface the drive is connected. 829Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 830@item bus=@var{bus},unit=@var{unit} 831These options define where is connected the drive by defining the bus number and 832the unit id. 833@item index=@var{index} 834This option defines where is connected the drive by using an index in the list 835of available connectors of a given interface type. 836@item media=@var{media} 837This option defines the type of the media: disk or cdrom. 838@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}] 839These options have the same definition as they have in @option{-hdachs}. 840These parameters are deprecated, use the corresponding parameters 841of @code{-device} instead. 842@item snapshot=@var{snapshot} 843@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 844(see @option{-snapshot}). 845@item cache=@var{cache} 846@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 847and controls how the host cache is used to access block data. This is a 848shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 849options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 850which provides a default for the @option{write-cache} option of block guest 851devices (as in @option{-device}). The modes correspond to the following 852settings: 853 854@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 855@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 856@c and the HTML output. 857@example 858@ │ cache.writeback cache.direct cache.no-flush 859─────────────┼───────────────────────────────────────────────── 860writeback │ on off off 861none │ on on off 862writethrough │ off off off 863directsync │ off on off 864unsafe │ on off on 865@end example 866 867The default mode is @option{cache=writeback}. 868 869@item aio=@var{aio} 870@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 871@item format=@var{format} 872Specify which disk @var{format} will be used rather than detecting 873the format. Can be used to specify format=raw to avoid interpreting 874an untrusted format header. 875@item serial=@var{serial} 876This option specifies the serial number to assign to the device. This 877parameter is deprecated, use the corresponding parameter of @code{-device} 878instead. 879@item addr=@var{addr} 880Specify the controller's PCI address (if=virtio only). This parameter is 881deprecated, use the corresponding parameter of @code{-device} instead. 882@item werror=@var{action},rerror=@var{action} 883Specify which @var{action} to take on write and read errors. Valid actions are: 884"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 885"report" (report the error to the guest), "enospc" (pause QEMU only if the 886host disk is full; report the error to the guest otherwise). 887The default setting is @option{werror=enospc} and @option{rerror=report}. 888@item copy-on-read=@var{copy-on-read} 889@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 890file sectors into the image file. 891@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 892Specify bandwidth throttling limits in bytes per second, either for all request 893types or for reads or writes only. Small values can lead to timeouts or hangs 894inside the guest. A safe minimum for disks is 2 MB/s. 895@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 896Specify bursts in bytes per second, either for all request types or for reads 897or writes only. Bursts allow the guest I/O to spike above the limit 898temporarily. 899@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 900Specify request rate limits in requests per second, either for all request 901types or for reads or writes only. 902@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 903Specify bursts in requests per second, either for all request types or for reads 904or writes only. Bursts allow the guest I/O to spike above the limit 905temporarily. 906@item iops_size=@var{is} 907Let every @var{is} bytes of a request count as a new request for iops 908throttling purposes. Use this option to prevent guests from circumventing iops 909limits by sending fewer but larger requests. 910@item group=@var{g} 911Join a throttling quota group with given name @var{g}. All drives that are 912members of the same group are accounted for together. Use this option to 913prevent guests from circumventing throttling limits by using many small disks 914instead of a single larger disk. 915@end table 916 917By default, the @option{cache.writeback=on} mode is used. It will report data 918writes as completed as soon as the data is present in the host page cache. 919This is safe as long as your guest OS makes sure to correctly flush disk caches 920where needed. If your guest OS does not handle volatile disk write caches 921correctly and your host crashes or loses power, then the guest may experience 922data corruption. 923 924For such guests, you should consider using @option{cache.writeback=off}. This 925means that the host page cache will be used to read and write data, but write 926notification will be sent to the guest only after QEMU has made sure to flush 927each write to the disk. Be aware that this has a major impact on performance. 928 929When using the @option{-snapshot} option, unsafe caching is always used. 930 931Copy-on-read avoids accessing the same backing file sectors repeatedly and is 932useful when the backing file is over a slow network. By default copy-on-read 933is off. 934 935Instead of @option{-cdrom} you can use: 936@example 937qemu-system-i386 -drive file=file,index=2,media=cdrom 938@end example 939 940Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 941use: 942@example 943qemu-system-i386 -drive file=file,index=0,media=disk 944qemu-system-i386 -drive file=file,index=1,media=disk 945qemu-system-i386 -drive file=file,index=2,media=disk 946qemu-system-i386 -drive file=file,index=3,media=disk 947@end example 948 949You can open an image using pre-opened file descriptors from an fd set: 950@example 951qemu-system-i386 952-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 953-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 954-drive file=/dev/fdset/2,index=0,media=disk 955@end example 956 957You can connect a CDROM to the slave of ide0: 958@example 959qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 960@end example 961 962If you don't specify the "file=" argument, you define an empty drive: 963@example 964qemu-system-i386 -drive if=ide,index=1,media=cdrom 965@end example 966 967Instead of @option{-fda}, @option{-fdb}, you can use: 968@example 969qemu-system-i386 -drive file=file,index=0,if=floppy 970qemu-system-i386 -drive file=file,index=1,if=floppy 971@end example 972 973By default, @var{interface} is "ide" and @var{index} is automatically 974incremented: 975@example 976qemu-system-i386 -drive file=a -drive file=b" 977@end example 978is interpreted like: 979@example 980qemu-system-i386 -hda a -hdb b 981@end example 982ETEXI 983 984DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 985 "-mtdblock file use 'file' as on-board Flash memory image\n", 986 QEMU_ARCH_ALL) 987STEXI 988@item -mtdblock @var{file} 989@findex -mtdblock 990Use @var{file} as on-board Flash memory image. 991ETEXI 992 993DEF("sd", HAS_ARG, QEMU_OPTION_sd, 994 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 995STEXI 996@item -sd @var{file} 997@findex -sd 998Use @var{file} as SecureDigital card image. 999ETEXI 1000 1001DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1002 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1003STEXI 1004@item -pflash @var{file} 1005@findex -pflash 1006Use @var{file} as a parallel flash image. 1007ETEXI 1008 1009DEF("snapshot", 0, QEMU_OPTION_snapshot, 1010 "-snapshot write to temporary files instead of disk image files\n", 1011 QEMU_ARCH_ALL) 1012STEXI 1013@item -snapshot 1014@findex -snapshot 1015Write to temporary files instead of disk image files. In this case, 1016the raw disk image you use is not written back. You can however force 1017the write back by pressing @key{C-a s} (@pxref{disk_images}). 1018ETEXI 1019 1020DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \ 1021 "-hdachs c,h,s[,t]\n" \ 1022 " force hard disk 0 physical geometry and the optional BIOS\n" \ 1023 " translation (t=none or lba) (usually QEMU can guess them)\n", 1024 QEMU_ARCH_ALL) 1025STEXI 1026@item -hdachs @var{c},@var{h},@var{s},[,@var{t}] 1027@findex -hdachs 1028Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <= 1029@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS 1030translation mode (@var{t}=none, lba or auto). Usually QEMU can guess 1031all those parameters. This option is deprecated, please use 1032@code{-device ide-hd,cyls=c,heads=h,secs=s,...} instead. 1033ETEXI 1034 1035DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1036 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 1037 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n" 1038 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1039 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1040 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1041 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1042 " [[,throttling.iops-size=is]]\n", 1043 QEMU_ARCH_ALL) 1044 1045STEXI 1046 1047@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}] 1048@findex -fsdev 1049Define a new file system device. Valid options are: 1050@table @option 1051@item @var{fsdriver} 1052This option specifies the fs driver backend to use. 1053Currently "local", "handle" and "proxy" file system drivers are supported. 1054@item id=@var{id} 1055Specifies identifier for this device 1056@item path=@var{path} 1057Specifies the export path for the file system device. Files under 1058this path will be available to the 9p client on the guest. 1059@item security_model=@var{security_model} 1060Specifies the security model to be used for this export path. 1061Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1062In "passthrough" security model, files are stored using the same 1063credentials as they are created on the guest. This requires QEMU 1064to run as root. In "mapped-xattr" security model, some of the file 1065attributes like uid, gid, mode bits and link target are stored as 1066file attributes. For "mapped-file" these attributes are stored in the 1067hidden .virtfs_metadata directory. Directories exported by this security model cannot 1068interact with other unix tools. "none" security model is same as 1069passthrough except the sever won't report failures if it fails to 1070set file attributes like ownership. Security model is mandatory 1071only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 1072security model as a parameter. 1073@item writeout=@var{writeout} 1074This is an optional argument. The only supported value is "immediate". 1075This means that host page cache will be used to read and write data but 1076write notification will be sent to the guest only when the data has been 1077reported as written by the storage subsystem. 1078@item readonly 1079Enables exporting 9p share as a readonly mount for guests. By default 1080read-write access is given. 1081@item socket=@var{socket} 1082Enables proxy filesystem driver to use passed socket file for communicating 1083with virtfs-proxy-helper 1084@item sock_fd=@var{sock_fd} 1085Enables proxy filesystem driver to use passed socket descriptor for 1086communicating with virtfs-proxy-helper. Usually a helper like libvirt 1087will create socketpair and pass one of the fds as sock_fd 1088@item fmode=@var{fmode} 1089Specifies the default mode for newly created files on the host. Works only 1090with security models "mapped-xattr" and "mapped-file". 1091@item dmode=@var{dmode} 1092Specifies the default mode for newly created directories on the host. Works 1093only with security models "mapped-xattr" and "mapped-file". 1094@end table 1095 1096-fsdev option is used along with -device driver "virtio-9p-pci". 1097@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 1098Options for virtio-9p-pci driver are: 1099@table @option 1100@item fsdev=@var{id} 1101Specifies the id value specified along with -fsdev option 1102@item mount_tag=@var{mount_tag} 1103Specifies the tag name to be used by the guest to mount this export point 1104@end table 1105 1106ETEXI 1107 1108DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1109 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 1110 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n", 1111 QEMU_ARCH_ALL) 1112 1113STEXI 1114 1115@item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}] 1116@findex -virtfs 1117 1118The general form of a Virtual File system pass-through options are: 1119@table @option 1120@item @var{fsdriver} 1121This option specifies the fs driver backend to use. 1122Currently "local", "handle" and "proxy" file system drivers are supported. 1123@item id=@var{id} 1124Specifies identifier for this device 1125@item path=@var{path} 1126Specifies the export path for the file system device. Files under 1127this path will be available to the 9p client on the guest. 1128@item security_model=@var{security_model} 1129Specifies the security model to be used for this export path. 1130Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1131In "passthrough" security model, files are stored using the same 1132credentials as they are created on the guest. This requires QEMU 1133to run as root. In "mapped-xattr" security model, some of the file 1134attributes like uid, gid, mode bits and link target are stored as 1135file attributes. For "mapped-file" these attributes are stored in the 1136hidden .virtfs_metadata directory. Directories exported by this security model cannot 1137interact with other unix tools. "none" security model is same as 1138passthrough except the sever won't report failures if it fails to 1139set file attributes like ownership. Security model is mandatory only 1140for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 1141model as a parameter. 1142@item writeout=@var{writeout} 1143This is an optional argument. The only supported value is "immediate". 1144This means that host page cache will be used to read and write data but 1145write notification will be sent to the guest only when the data has been 1146reported as written by the storage subsystem. 1147@item readonly 1148Enables exporting 9p share as a readonly mount for guests. By default 1149read-write access is given. 1150@item socket=@var{socket} 1151Enables proxy filesystem driver to use passed socket file for 1152communicating with virtfs-proxy-helper. Usually a helper like libvirt 1153will create socketpair and pass one of the fds as sock_fd 1154@item sock_fd 1155Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1156descriptor for interfacing with virtfs-proxy-helper 1157@item fmode=@var{fmode} 1158Specifies the default mode for newly created files on the host. Works only 1159with security models "mapped-xattr" and "mapped-file". 1160@item dmode=@var{dmode} 1161Specifies the default mode for newly created directories on the host. Works 1162only with security models "mapped-xattr" and "mapped-file". 1163@end table 1164ETEXI 1165 1166DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1167 "-virtfs_synth Create synthetic file system image\n", 1168 QEMU_ARCH_ALL) 1169STEXI 1170@item -virtfs_synth 1171@findex -virtfs_synth 1172Create synthetic file system image 1173ETEXI 1174 1175STEXI 1176@end table 1177ETEXI 1178DEFHEADING() 1179 1180DEFHEADING(USB options) 1181STEXI 1182@table @option 1183ETEXI 1184 1185DEF("usb", 0, QEMU_OPTION_usb, 1186 "-usb enable the USB driver (if it is not used by default yet)\n", 1187 QEMU_ARCH_ALL) 1188STEXI 1189@item -usb 1190@findex -usb 1191Enable the USB driver (if it is not used by default yet). 1192ETEXI 1193 1194DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1195 "-usbdevice name add the host or guest USB device 'name'\n", 1196 QEMU_ARCH_ALL) 1197STEXI 1198 1199@item -usbdevice @var{devname} 1200@findex -usbdevice 1201Add the USB device @var{devname}. Note that this option is deprecated, 1202please use @code{-device usb-...} instead. @xref{usb_devices}. 1203 1204@table @option 1205 1206@item mouse 1207Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1208 1209@item tablet 1210Pointer device that uses absolute coordinates (like a touchscreen). This 1211means QEMU is able to report the mouse position without having to grab the 1212mouse. Also overrides the PS/2 mouse emulation when activated. 1213 1214@item disk:[format=@var{format}]:@var{file} 1215Mass storage device based on file. The optional @var{format} argument 1216will be used rather than detecting the format. Can be used to specify 1217@code{format=raw} to avoid interpreting an untrusted format header. 1218 1219@item host:@var{bus}.@var{addr} 1220Pass through the host device identified by @var{bus}.@var{addr} (Linux only). 1221 1222@item host:@var{vendor_id}:@var{product_id} 1223Pass through the host device identified by @var{vendor_id}:@var{product_id} 1224(Linux only). 1225 1226@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev} 1227Serial converter to host character device @var{dev}, see @code{-serial} for the 1228available devices. 1229 1230@item braille 1231Braille device. This will use BrlAPI to display the braille output on a real 1232or fake device. 1233 1234@item net:@var{options} 1235Network adapter that supports CDC ethernet and RNDIS protocols. 1236 1237@end table 1238ETEXI 1239 1240STEXI 1241@end table 1242ETEXI 1243DEFHEADING() 1244 1245DEFHEADING(Display options) 1246STEXI 1247@table @option 1248ETEXI 1249 1250DEF("display", HAS_ARG, QEMU_OPTION_display, 1251 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1252 " [,window_close=on|off][,gl=on|off]\n" 1253 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1254 "-display vnc=<display>[,<optargs>]\n" 1255 "-display curses\n" 1256 "-display none" 1257 " select display type\n" 1258 "The default display is equivalent to\n" 1259#if defined(CONFIG_GTK) 1260 "\t\"-display gtk\"\n" 1261#elif defined(CONFIG_SDL) 1262 "\t\"-display sdl\"\n" 1263#elif defined(CONFIG_COCOA) 1264 "\t\"-display cocoa\"\n" 1265#elif defined(CONFIG_VNC) 1266 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1267#else 1268 "\t\"-display none\"\n" 1269#endif 1270 , QEMU_ARCH_ALL) 1271STEXI 1272@item -display @var{type} 1273@findex -display 1274Select type of display to use. This option is a replacement for the 1275old style -sdl/-curses/... options. Valid values for @var{type} are 1276@table @option 1277@item sdl 1278Display video output via SDL (usually in a separate graphics 1279window; see the SDL documentation for other possibilities). 1280@item curses 1281Display video output via curses. For graphics device models which 1282support a text mode, QEMU can display this output using a 1283curses/ncurses interface. Nothing is displayed when the graphics 1284device is in graphical mode or if the graphics device does not support 1285a text mode. Generally only the VGA device models support text mode. 1286@item none 1287Do not display video output. The guest will still see an emulated 1288graphics card, but its output will not be displayed to the QEMU 1289user. This option differs from the -nographic option in that it 1290only affects what is done with video output; -nographic also changes 1291the destination of the serial and parallel port data. 1292@item gtk 1293Display video output in a GTK window. This interface provides drop-down 1294menus and other UI elements to configure and control the VM during 1295runtime. 1296@item vnc 1297Start a VNC server on display <arg> 1298@end table 1299ETEXI 1300 1301DEF("nographic", 0, QEMU_OPTION_nographic, 1302 "-nographic disable graphical output and redirect serial I/Os to console\n", 1303 QEMU_ARCH_ALL) 1304STEXI 1305@item -nographic 1306@findex -nographic 1307Normally, if QEMU is compiled with graphical window support, it displays 1308output such as guest graphics, guest console, and the QEMU monitor in a 1309window. With this option, you can totally disable graphical output so 1310that QEMU is a simple command line application. The emulated serial port 1311is redirected on the console and muxed with the monitor (unless 1312redirected elsewhere explicitly). Therefore, you can still use QEMU to 1313debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1314switching between the console and monitor. 1315ETEXI 1316 1317DEF("curses", 0, QEMU_OPTION_curses, 1318 "-curses shorthand for -display curses\n", 1319 QEMU_ARCH_ALL) 1320STEXI 1321@item -curses 1322@findex -curses 1323Normally, if QEMU is compiled with graphical window support, it displays 1324output such as guest graphics, guest console, and the QEMU monitor in a 1325window. With this option, QEMU can display the VGA output when in text 1326mode using a curses/ncurses interface. Nothing is displayed in graphical 1327mode. 1328ETEXI 1329 1330DEF("no-frame", 0, QEMU_OPTION_no_frame, 1331 "-no-frame open SDL window without a frame and window decorations\n", 1332 QEMU_ARCH_ALL) 1333STEXI 1334@item -no-frame 1335@findex -no-frame 1336Do not use decorations for SDL windows and start them using the whole 1337available screen space. This makes the using QEMU in a dedicated desktop 1338workspace more convenient. 1339ETEXI 1340 1341DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1342 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1343 QEMU_ARCH_ALL) 1344STEXI 1345@item -alt-grab 1346@findex -alt-grab 1347Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1348affects the special keys (for fullscreen, monitor-mode switching, etc). 1349ETEXI 1350 1351DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1352 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1353 QEMU_ARCH_ALL) 1354STEXI 1355@item -ctrl-grab 1356@findex -ctrl-grab 1357Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1358affects the special keys (for fullscreen, monitor-mode switching, etc). 1359ETEXI 1360 1361DEF("no-quit", 0, QEMU_OPTION_no_quit, 1362 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1363STEXI 1364@item -no-quit 1365@findex -no-quit 1366Disable SDL window close capability. 1367ETEXI 1368 1369DEF("sdl", 0, QEMU_OPTION_sdl, 1370 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1371STEXI 1372@item -sdl 1373@findex -sdl 1374Enable SDL. 1375ETEXI 1376 1377DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1378 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1379 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1380 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1381 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1382 " [,tls-ciphers=<list>]\n" 1383 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1384 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1385 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1386 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1387 " [,jpeg-wan-compression=[auto|never|always]]\n" 1388 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1389 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1390 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1391 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1392 " [,gl=[on|off]][,rendernode=<file>]\n" 1393 " enable spice\n" 1394 " at least one of {port, tls-port} is mandatory\n", 1395 QEMU_ARCH_ALL) 1396STEXI 1397@item -spice @var{option}[,@var{option}[,...]] 1398@findex -spice 1399Enable the spice remote desktop protocol. Valid options are 1400 1401@table @option 1402 1403@item port=<nr> 1404Set the TCP port spice is listening on for plaintext channels. 1405 1406@item addr=<addr> 1407Set the IP address spice is listening on. Default is any address. 1408 1409@item ipv4 1410@itemx ipv6 1411@itemx unix 1412Force using the specified IP version. 1413 1414@item password=<secret> 1415Set the password you need to authenticate. 1416 1417@item sasl 1418Require that the client use SASL to authenticate with the spice. 1419The exact choice of authentication method used is controlled from the 1420system / user's SASL configuration file for the 'qemu' service. This 1421is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1422unprivileged user, an environment variable SASL_CONF_PATH can be used 1423to make it search alternate locations for the service config. 1424While some SASL auth methods can also provide data encryption (eg GSSAPI), 1425it is recommended that SASL always be combined with the 'tls' and 1426'x509' settings to enable use of SSL and server certificates. This 1427ensures a data encryption preventing compromise of authentication 1428credentials. 1429 1430@item disable-ticketing 1431Allow client connects without authentication. 1432 1433@item disable-copy-paste 1434Disable copy paste between the client and the guest. 1435 1436@item disable-agent-file-xfer 1437Disable spice-vdagent based file-xfer between the client and the guest. 1438 1439@item tls-port=<nr> 1440Set the TCP port spice is listening on for encrypted channels. 1441 1442@item x509-dir=<dir> 1443Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1444 1445@item x509-key-file=<file> 1446@itemx x509-key-password=<file> 1447@itemx x509-cert-file=<file> 1448@itemx x509-cacert-file=<file> 1449@itemx x509-dh-key-file=<file> 1450The x509 file names can also be configured individually. 1451 1452@item tls-ciphers=<list> 1453Specify which ciphers to use. 1454 1455@item tls-channel=[main|display|cursor|inputs|record|playback] 1456@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1457Force specific channel to be used with or without TLS encryption. The 1458options can be specified multiple times to configure multiple 1459channels. The special name "default" can be used to set the default 1460mode. For channels which are not explicitly forced into one mode the 1461spice client is allowed to pick tls/plaintext as he pleases. 1462 1463@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1464Configure image compression (lossless). 1465Default is auto_glz. 1466 1467@item jpeg-wan-compression=[auto|never|always] 1468@itemx zlib-glz-wan-compression=[auto|never|always] 1469Configure wan image compression (lossy for slow links). 1470Default is auto. 1471 1472@item streaming-video=[off|all|filter] 1473Configure video stream detection. Default is off. 1474 1475@item agent-mouse=[on|off] 1476Enable/disable passing mouse events via vdagent. Default is on. 1477 1478@item playback-compression=[on|off] 1479Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1480 1481@item seamless-migration=[on|off] 1482Enable/disable spice seamless migration. Default is off. 1483 1484@item gl=[on|off] 1485Enable/disable OpenGL context. Default is off. 1486 1487@item rendernode=<file> 1488DRM render node for OpenGL rendering. If not specified, it will pick 1489the first available. (Since 2.9) 1490 1491@end table 1492ETEXI 1493 1494DEF("portrait", 0, QEMU_OPTION_portrait, 1495 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1496 QEMU_ARCH_ALL) 1497STEXI 1498@item -portrait 1499@findex -portrait 1500Rotate graphical output 90 deg left (only PXA LCD). 1501ETEXI 1502 1503DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1504 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1505 QEMU_ARCH_ALL) 1506STEXI 1507@item -rotate @var{deg} 1508@findex -rotate 1509Rotate graphical output some deg left (only PXA LCD). 1510ETEXI 1511 1512DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1513 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1514 " select video card type\n", QEMU_ARCH_ALL) 1515STEXI 1516@item -vga @var{type} 1517@findex -vga 1518Select type of VGA card to emulate. Valid values for @var{type} are 1519@table @option 1520@item cirrus 1521Cirrus Logic GD5446 Video card. All Windows versions starting from 1522Windows 95 should recognize and use this graphic card. For optimal 1523performances, use 16 bit color depth in the guest and the host OS. 1524(This card was the default before QEMU 2.2) 1525@item std 1526Standard VGA card with Bochs VBE extensions. If your guest OS 1527supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1528to use high resolution modes (>= 1280x1024x16) then you should use 1529this option. (This card is the default since QEMU 2.2) 1530@item vmware 1531VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1532recent XFree86/XOrg server or Windows guest with a driver for this 1533card. 1534@item qxl 1535QXL paravirtual graphic card. It is VGA compatible (including VESA 15362.0 VBE support). Works best with qxl guest drivers installed though. 1537Recommended choice when using the spice protocol. 1538@item tcx 1539(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1540sun4m machines and offers both 8-bit and 24-bit colour depths at a 1541fixed resolution of 1024x768. 1542@item cg3 1543(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1544for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1545resolutions aimed at people wishing to run older Solaris versions. 1546@item virtio 1547Virtio VGA card. 1548@item none 1549Disable VGA card. 1550@end table 1551ETEXI 1552 1553DEF("full-screen", 0, QEMU_OPTION_full_screen, 1554 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1555STEXI 1556@item -full-screen 1557@findex -full-screen 1558Start in full screen. 1559ETEXI 1560 1561DEF("g", 1, QEMU_OPTION_g , 1562 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1563 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1564STEXI 1565@item -g @var{width}x@var{height}[x@var{depth}] 1566@findex -g 1567Set the initial graphical resolution and depth (PPC, SPARC only). 1568ETEXI 1569 1570DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1571 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1572STEXI 1573@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1574@findex -vnc 1575Normally, if QEMU is compiled with graphical window support, it displays 1576output such as guest graphics, guest console, and the QEMU monitor in a 1577window. With this option, you can have QEMU listen on VNC display 1578@var{display} and redirect the VGA display over the VNC session. It is 1579very useful to enable the usb tablet device when using this option 1580(option @option{-device usb-tablet}). When using the VNC display, you 1581must use the @option{-k} parameter to set the keyboard layout if you are 1582not using en-us. Valid syntax for the @var{display} is 1583 1584@table @option 1585 1586@item to=@var{L} 1587 1588With this option, QEMU will try next available VNC @var{display}s, until the 1589number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1590available, e.g. port 5900+@var{display} is already used by another 1591application. By default, to=0. 1592 1593@item @var{host}:@var{d} 1594 1595TCP connections will only be allowed from @var{host} on display @var{d}. 1596By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1597be omitted in which case the server will accept connections from any host. 1598 1599@item unix:@var{path} 1600 1601Connections will be allowed over UNIX domain sockets where @var{path} is the 1602location of a unix socket to listen for connections on. 1603 1604@item none 1605 1606VNC is initialized but not started. The monitor @code{change} command 1607can be used to later start the VNC server. 1608 1609@end table 1610 1611Following the @var{display} value there may be one or more @var{option} flags 1612separated by commas. Valid options are 1613 1614@table @option 1615 1616@item reverse 1617 1618Connect to a listening VNC client via a ``reverse'' connection. The 1619client is specified by the @var{display}. For reverse network 1620connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1621is a TCP port number, not a display number. 1622 1623@item websocket 1624 1625Opens an additional TCP listening port dedicated to VNC Websocket connections. 1626If a bare @var{websocket} option is given, the Websocket port is 16275700+@var{display}. An alternative port can be specified with the 1628syntax @code{websocket}=@var{port}. 1629 1630If @var{host} is specified connections will only be allowed from this host. 1631It is possible to control the websocket listen address independently, using 1632the syntax @code{websocket}=@var{host}:@var{port}. 1633 1634If no TLS credentials are provided, the websocket connection runs in 1635unencrypted mode. If TLS credentials are provided, the websocket connection 1636requires encrypted client connections. 1637 1638@item password 1639 1640Require that password based authentication is used for client connections. 1641 1642The password must be set separately using the @code{set_password} command in 1643the @ref{pcsys_monitor}. The syntax to change your password is: 1644@code{set_password <protocol> <password>} where <protocol> could be either 1645"vnc" or "spice". 1646 1647If you would like to change <protocol> password expiration, you should use 1648@code{expire_password <protocol> <expiration-time>} where expiration time could 1649be one of the following options: now, never, +seconds or UNIX time of 1650expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1651to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1652date and time). 1653 1654You can also use keywords "now" or "never" for the expiration time to 1655allow <protocol> password to expire immediately or never expire. 1656 1657@item tls-creds=@var{ID} 1658 1659Provides the ID of a set of TLS credentials to use to secure the 1660VNC server. They will apply to both the normal VNC server socket 1661and the websocket socket (if enabled). Setting TLS credentials 1662will cause the VNC server socket to enable the VeNCrypt auth 1663mechanism. The credentials should have been previously created 1664using the @option{-object tls-creds} argument. 1665 1666The @option{tls-creds} parameter obsoletes the @option{tls}, 1667@option{x509}, and @option{x509verify} options, and as such 1668it is not permitted to set both new and old type options at 1669the same time. 1670 1671@item tls 1672 1673Require that client use TLS when communicating with the VNC server. This 1674uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1675attack. It is recommended that this option be combined with either the 1676@option{x509} or @option{x509verify} options. 1677 1678This option is now deprecated in favor of using the @option{tls-creds} 1679argument. 1680 1681@item x509=@var{/path/to/certificate/dir} 1682 1683Valid if @option{tls} is specified. Require that x509 credentials are used 1684for negotiating the TLS session. The server will send its x509 certificate 1685to the client. It is recommended that a password be set on the VNC server 1686to provide authentication of the client when this is used. The path following 1687this option specifies where the x509 certificates are to be loaded from. 1688See the @ref{vnc_security} section for details on generating certificates. 1689 1690This option is now deprecated in favour of using the @option{tls-creds} 1691argument. 1692 1693@item x509verify=@var{/path/to/certificate/dir} 1694 1695Valid if @option{tls} is specified. Require that x509 credentials are used 1696for negotiating the TLS session. The server will send its x509 certificate 1697to the client, and request that the client send its own x509 certificate. 1698The server will validate the client's certificate against the CA certificate, 1699and reject clients when validation fails. If the certificate authority is 1700trusted, this is a sufficient authentication mechanism. You may still wish 1701to set a password on the VNC server as a second authentication layer. The 1702path following this option specifies where the x509 certificates are to 1703be loaded from. See the @ref{vnc_security} section for details on generating 1704certificates. 1705 1706This option is now deprecated in favour of using the @option{tls-creds} 1707argument. 1708 1709@item sasl 1710 1711Require that the client use SASL to authenticate with the VNC server. 1712The exact choice of authentication method used is controlled from the 1713system / user's SASL configuration file for the 'qemu' service. This 1714is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1715unprivileged user, an environment variable SASL_CONF_PATH can be used 1716to make it search alternate locations for the service config. 1717While some SASL auth methods can also provide data encryption (eg GSSAPI), 1718it is recommended that SASL always be combined with the 'tls' and 1719'x509' settings to enable use of SSL and server certificates. This 1720ensures a data encryption preventing compromise of authentication 1721credentials. See the @ref{vnc_security} section for details on using 1722SASL authentication. 1723 1724@item acl 1725 1726Turn on access control lists for checking of the x509 client certificate 1727and SASL party. For x509 certs, the ACL check is made against the 1728certificate's distinguished name. This is something that looks like 1729@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1730made against the username, which depending on the SASL plugin, may 1731include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1732When the @option{acl} flag is set, the initial access list will be 1733empty, with a @code{deny} policy. Thus no one will be allowed to 1734use the VNC server until the ACLs have been loaded. This can be 1735achieved using the @code{acl} monitor command. 1736 1737@item lossy 1738 1739Enable lossy compression methods (gradient, JPEG, ...). If this 1740option is set, VNC client may receive lossy framebuffer updates 1741depending on its encoding settings. Enabling this option can save 1742a lot of bandwidth at the expense of quality. 1743 1744@item non-adaptive 1745 1746Disable adaptive encodings. Adaptive encodings are enabled by default. 1747An adaptive encoding will try to detect frequently updated screen regions, 1748and send updates in these regions using a lossy encoding (like JPEG). 1749This can be really helpful to save bandwidth when playing videos. Disabling 1750adaptive encodings restores the original static behavior of encodings 1751like Tight. 1752 1753@item share=[allow-exclusive|force-shared|ignore] 1754 1755Set display sharing policy. 'allow-exclusive' allows clients to ask 1756for exclusive access. As suggested by the rfb spec this is 1757implemented by dropping other connections. Connecting multiple 1758clients in parallel requires all clients asking for a shared session 1759(vncviewer: -shared switch). This is the default. 'force-shared' 1760disables exclusive client access. Useful for shared desktop sessions, 1761where you don't want someone forgetting specify -shared disconnect 1762everybody else. 'ignore' completely ignores the shared flag and 1763allows everybody connect unconditionally. Doesn't conform to the rfb 1764spec but is traditional QEMU behavior. 1765 1766@item key-delay-ms 1767 1768Set keyboard delay, for key down and key up events, in milliseconds. 1769Default is 10. Keyboards are low-bandwidth devices, so this slowdown 1770can help the device and guest to keep up and not lose events in case 1771events are arriving in bulk. Possible causes for the latter are flaky 1772network connections, or scripts for automated testing. 1773 1774@end table 1775ETEXI 1776 1777STEXI 1778@end table 1779ETEXI 1780ARCHHEADING(, QEMU_ARCH_I386) 1781 1782ARCHHEADING(i386 target only, QEMU_ARCH_I386) 1783STEXI 1784@table @option 1785ETEXI 1786 1787DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1788 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1789 QEMU_ARCH_I386) 1790STEXI 1791@item -win2k-hack 1792@findex -win2k-hack 1793Use it when installing Windows 2000 to avoid a disk full bug. After 1794Windows 2000 is installed, you no longer need this option (this option 1795slows down the IDE transfers). 1796ETEXI 1797 1798HXCOMM Deprecated by -rtc 1799DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1800 1801DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1802 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1803 QEMU_ARCH_I386) 1804STEXI 1805@item -no-fd-bootchk 1806@findex -no-fd-bootchk 1807Disable boot signature checking for floppy disks in BIOS. May 1808be needed to boot from old floppy disks. 1809ETEXI 1810 1811DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1812 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1813STEXI 1814@item -no-acpi 1815@findex -no-acpi 1816Disable ACPI (Advanced Configuration and Power Interface) support. Use 1817it if your guest OS complains about ACPI problems (PC target machine 1818only). 1819ETEXI 1820 1821DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1822 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1823STEXI 1824@item -no-hpet 1825@findex -no-hpet 1826Disable HPET support. 1827ETEXI 1828 1829DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1830 "-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" 1831 " ACPI table description\n", QEMU_ARCH_I386) 1832STEXI 1833@item -acpitable [sig=@var{str}][,rev=@var{n}][,oem_id=@var{str}][,oem_table_id=@var{str}][,oem_rev=@var{n}] [,asl_compiler_id=@var{str}][,asl_compiler_rev=@var{n}][,data=@var{file1}[:@var{file2}]...] 1834@findex -acpitable 1835Add ACPI table with specified header fields and context from specified files. 1836For file=, take whole ACPI table from the specified files, including all 1837ACPI headers (possible overridden by other options). 1838For data=, only data 1839portion of the table is used, all header information is specified in the 1840command line. 1841If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 1842fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 1843to ensure the field matches required by the Microsoft SLIC spec and the ACPI 1844spec. 1845ETEXI 1846 1847DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1848 "-smbios file=binary\n" 1849 " load SMBIOS entry from binary file\n" 1850 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1851 " [,uefi=on|off]\n" 1852 " specify SMBIOS type 0 fields\n" 1853 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1854 " [,uuid=uuid][,sku=str][,family=str]\n" 1855 " specify SMBIOS type 1 fields\n" 1856 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1857 " [,asset=str][,location=str]\n" 1858 " specify SMBIOS type 2 fields\n" 1859 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1860 " [,sku=str]\n" 1861 " specify SMBIOS type 3 fields\n" 1862 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1863 " [,asset=str][,part=str]\n" 1864 " specify SMBIOS type 4 fields\n" 1865 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1866 " [,asset=str][,part=str][,speed=%d]\n" 1867 " specify SMBIOS type 17 fields\n", 1868 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1869STEXI 1870@item -smbios file=@var{binary} 1871@findex -smbios 1872Load SMBIOS entry from binary file. 1873 1874@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1875Specify SMBIOS type 0 fields 1876 1877@item -smbios type=1[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,uuid=@var{uuid}][,sku=@var{str}][,family=@var{str}] 1878Specify SMBIOS type 1 fields 1879 1880@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}][,family=@var{str}] 1881Specify SMBIOS type 2 fields 1882 1883@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1884Specify SMBIOS type 3 fields 1885 1886@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1887Specify SMBIOS type 4 fields 1888 1889@item -smbios type=17[,loc_pfx=@var{str}][,bank=@var{str}][,manufacturer=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,speed=@var{%d}] 1890Specify SMBIOS type 17 fields 1891ETEXI 1892 1893STEXI 1894@end table 1895ETEXI 1896DEFHEADING() 1897 1898DEFHEADING(Network options) 1899STEXI 1900@table @option 1901ETEXI 1902 1903HXCOMM Legacy slirp options (now moved to -net user): 1904#ifdef CONFIG_SLIRP 1905DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1906DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1907DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1908#ifndef _WIN32 1909DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1910#endif 1911#endif 1912 1913DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1914#ifdef CONFIG_SLIRP 1915 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 1916 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 1917 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 1918 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n" 1919 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1920#ifndef _WIN32 1921 "[,smb=dir[,smbserver=addr]]\n" 1922#endif 1923 " configure a user mode network backend with ID 'str',\n" 1924 " its DHCP server and optional services\n" 1925#endif 1926#ifdef _WIN32 1927 "-netdev tap,id=str,ifname=name\n" 1928 " configure a host TAP network backend with ID 'str'\n" 1929#else 1930 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1931 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1932 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1933 " [,poll-us=n]\n" 1934 " configure a host TAP network backend with ID 'str'\n" 1935 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1936 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1937 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1938 " to deconfigure it\n" 1939 " use '[down]script=no' to disable script execution\n" 1940 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1941 " configure it\n" 1942 " use 'fd=h' to connect to an already opened TAP interface\n" 1943 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1944 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1945 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1946 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1947 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1948 " use vhost=on to enable experimental in kernel accelerator\n" 1949 " (only has effect for virtio guests which use MSIX)\n" 1950 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1951 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1952 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1953 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1954 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 1955 " spent on busy polling for vhost net\n" 1956 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1957 " configure a host TAP network backend with ID 'str' that is\n" 1958 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1959 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1960#endif 1961#ifdef __linux__ 1962 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1963 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1964 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1965 " [,rxcookie=rxcookie][,offset=offset]\n" 1966 " configure a network backend with ID 'str' connected to\n" 1967 " an Ethernet over L2TPv3 pseudowire.\n" 1968 " Linux kernel 3.3+ as well as most routers can talk\n" 1969 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1970 " VM to a router and even VM to Host. It is a nearly-universal\n" 1971 " standard (RFC3391). Note - this implementation uses static\n" 1972 " pre-configured tunnels (same as the Linux kernel).\n" 1973 " use 'src=' to specify source address\n" 1974 " use 'dst=' to specify destination address\n" 1975 " use 'udp=on' to specify udp encapsulation\n" 1976 " use 'srcport=' to specify source udp port\n" 1977 " use 'dstport=' to specify destination udp port\n" 1978 " use 'ipv6=on' to force v6\n" 1979 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1980 " well as a weak security measure\n" 1981 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1982 " use 'txcookie=0x012345678' to specify a txcookie\n" 1983 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1984 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1985 " use 'pincounter=on' to work around broken counter handling in peer\n" 1986 " use 'offset=X' to add an extra offset between header and data\n" 1987#endif 1988 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1989 " configure a network backend to connect to another network\n" 1990 " using a socket connection\n" 1991 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1992 " configure a network backend to connect to a multicast maddr and port\n" 1993 " use 'localaddr=addr' to specify the host address to send packets from\n" 1994 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1995 " configure a network backend to connect to another network\n" 1996 " using an UDP tunnel\n" 1997#ifdef CONFIG_VDE 1998 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1999 " configure a network backend to connect to port 'n' of a vde switch\n" 2000 " running on host and listening for incoming connections on 'socketpath'.\n" 2001 " Use group 'groupname' and mode 'octalmode' to change default\n" 2002 " ownership and permissions for communication port.\n" 2003#endif 2004#ifdef CONFIG_NETMAP 2005 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2006 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2007 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2008 " netmap device, defaults to '/dev/netmap')\n" 2009#endif 2010 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2011 " configure a vhost-user network, backed by a chardev 'dev'\n" 2012 "-netdev hubport,id=str,hubid=n\n" 2013 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL) 2014DEF("net", HAS_ARG, QEMU_OPTION_net, 2015 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2016 " old way to create a new NIC and connect it to VLAN 'n'\n" 2017 " (use the '-device devtype,netdev=str' option if possible instead)\n" 2018 "-net dump[,vlan=n][,file=f][,len=n]\n" 2019 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n" 2020 "-net none use it alone to have zero network devices. If no -net option\n" 2021 " is provided, the default is '-net nic -net user'\n" 2022 "-net [" 2023#ifdef CONFIG_SLIRP 2024 "user|" 2025#endif 2026 "tap|" 2027 "bridge|" 2028#ifdef CONFIG_VDE 2029 "vde|" 2030#endif 2031#ifdef CONFIG_NETMAP 2032 "netmap|" 2033#endif 2034 "socket][,vlan=n][,option][,option][,...]\n" 2035 " old way to initialize a host network interface\n" 2036 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2037STEXI 2038@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2039@findex -net 2040Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n} 2041= 0 is the default). The NIC is an e1000 by default on the PC 2042target. Optionally, the MAC address can be changed to @var{mac}, the 2043device address set to @var{addr} (PCI cards only), 2044and a @var{name} can be assigned for use in monitor commands. 2045Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2046that the card should have; this option currently only affects virtio cards; set 2047@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2048NIC is created. QEMU can emulate several different models of network card. 2049Valid values for @var{type} are 2050@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er}, 2051@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139}, 2052@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}. 2053Not all devices are supported on all targets. Use @code{-net nic,model=help} 2054for a list of available devices for your target. 2055 2056@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2057@findex -netdev 2058@item -net user[,@var{option}][,@var{option}][,...] 2059Use the user mode network stack which requires no administrator 2060privilege to run. Valid options are: 2061 2062@table @option 2063@item vlan=@var{n} 2064Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default). 2065 2066@item id=@var{id} 2067@itemx name=@var{name} 2068Assign symbolic name for use in monitor commands. 2069 2070@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must 2071be enabled. If neither is specified both protocols are enabled. 2072 2073@item net=@var{addr}[/@var{mask}] 2074Set IP network address the guest will see. Optionally specify the netmask, 2075either in the form a.b.c.d or as number of valid top-most bits. Default is 207610.0.2.0/24. 2077 2078@item host=@var{addr} 2079Specify the guest-visible address of the host. Default is the 2nd IP in the 2080guest network, i.e. x.x.x.2. 2081 2082@item ipv6-net=@var{addr}[/@var{int}] 2083Set IPv6 network address the guest will see (default is fec0::/64). The 2084network prefix is given in the usual hexadecimal IPv6 address 2085notation. The prefix size is optional, and is given as the number of 2086valid top-most bits (default is 64). 2087 2088@item ipv6-host=@var{addr} 2089Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2090the guest network, i.e. xxxx::2. 2091 2092@item restrict=on|off 2093If this option is enabled, the guest will be isolated, i.e. it will not be 2094able to contact the host and no guest IP packets will be routed over the host 2095to the outside. This option does not affect any explicitly set forwarding rules. 2096 2097@item hostname=@var{name} 2098Specifies the client hostname reported by the built-in DHCP server. 2099 2100@item dhcpstart=@var{addr} 2101Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2102is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2103 2104@item dns=@var{addr} 2105Specify the guest-visible address of the virtual nameserver. The address must 2106be different from the host address. Default is the 3rd IP in the guest network, 2107i.e. x.x.x.3. 2108 2109@item ipv6-dns=@var{addr} 2110Specify the guest-visible address of the IPv6 virtual nameserver. The address 2111must be different from the host address. Default is the 3rd IP in the guest 2112network, i.e. xxxx::3. 2113 2114@item dnssearch=@var{domain} 2115Provides an entry for the domain-search list sent by the built-in 2116DHCP server. More than one domain suffix can be transmitted by specifying 2117this option multiple times. If supported, this will cause the guest to 2118automatically try to append the given domain suffix(es) in case a domain name 2119can not be resolved. 2120 2121Example: 2122@example 2123qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...] 2124@end example 2125 2126@item tftp=@var{dir} 2127When using the user mode network stack, activate a built-in TFTP 2128server. The files in @var{dir} will be exposed as the root of a TFTP server. 2129The TFTP client on the guest must be configured in binary mode (use the command 2130@code{bin} of the Unix TFTP client). 2131 2132@item bootfile=@var{file} 2133When using the user mode network stack, broadcast @var{file} as the BOOTP 2134filename. In conjunction with @option{tftp}, this can be used to network boot 2135a guest from a local directory. 2136 2137Example (using pxelinux): 2138@example 2139qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2140@end example 2141 2142@item smb=@var{dir}[,smbserver=@var{addr}] 2143When using the user mode network stack, activate a built-in SMB 2144server so that Windows OSes can access to the host files in @file{@var{dir}} 2145transparently. The IP address of the SMB server can be set to @var{addr}. By 2146default the 4th IP in the guest network is used, i.e. x.x.x.4. 2147 2148In the guest Windows OS, the line: 2149@example 215010.0.2.4 smbserver 2151@end example 2152must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2153or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2154 2155Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2156 2157Note that a SAMBA server must be installed on the host OS. 2158QEMU was tested successfully with smbd versions from Red Hat 9, 2159Fedora Core 3 and OpenSUSE 11.x. 2160 2161@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2162Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2163the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2164@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2165given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2166be bound to a specific host interface. If no connection type is set, TCP is 2167used. This option can be given multiple times. 2168 2169For example, to redirect host X11 connection from screen 1 to guest 2170screen 0, use the following: 2171 2172@example 2173# on the host 2174qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...] 2175# this host xterm should open in the guest X11 server 2176xterm -display :1 2177@end example 2178 2179To redirect telnet connections from host port 5555 to telnet port on 2180the guest, use the following: 2181 2182@example 2183# on the host 2184qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...] 2185telnet localhost 5555 2186@end example 2187 2188Then when you use on the host @code{telnet localhost 5555}, you 2189connect to the guest telnet server. 2190 2191@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2192@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2193Forward guest TCP connections to the IP address @var{server} on port @var{port} 2194to the character device @var{dev} or to a program executed by @var{cmd:command} 2195which gets spawned for each connection. This option can be given multiple times. 2196 2197You can either use a chardev directly and have that one used throughout QEMU's 2198lifetime, like in the following example: 2199 2200@example 2201# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2202# the guest accesses it 2203qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...] 2204@end example 2205 2206Or you can execute a command on every TCP connection established by the guest, 2207so that QEMU behaves similar to an inetd process for that virtual server: 2208 2209@example 2210# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2211# and connect the TCP stream to its stdin/stdout 2212qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2213@end example 2214 2215@end table 2216 2217Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 2218processed and applied to -net user. Mixing them with the new configuration 2219syntax gives undefined results. Their use for new applications is discouraged 2220as they will be removed from future versions. 2221 2222@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2223@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2224Connect the host TAP network interface @var{name} to VLAN @var{n}. 2225 2226Use the network script @var{file} to configure it and the network script 2227@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2228automatically provides one. The default network configure script is 2229@file{/etc/qemu-ifup} and the default network deconfigure script is 2230@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2231to disable script execution. 2232 2233If running QEMU as an unprivileged user, use the network helper 2234@var{helper} to configure the TAP interface and attach it to the bridge. 2235The default network helper executable is @file{/path/to/qemu-bridge-helper} 2236and the default bridge device is @file{br0}. 2237 2238@option{fd}=@var{h} can be used to specify the handle of an already 2239opened host TAP interface. 2240 2241Examples: 2242 2243@example 2244#launch a QEMU instance with the default network script 2245qemu-system-i386 linux.img -net nic -net tap 2246@end example 2247 2248@example 2249#launch a QEMU instance with two NICs, each one connected 2250#to a TAP device 2251qemu-system-i386 linux.img \ 2252 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ 2253 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 2254@end example 2255 2256@example 2257#launch a QEMU instance with the default network helper to 2258#connect a TAP device to bridge br0 2259qemu-system-i386 linux.img \ 2260 -net nic -net tap,"helper=/path/to/qemu-bridge-helper" 2261@end example 2262 2263@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2264@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}] 2265Connect a host TAP network interface to a host bridge device. 2266 2267Use the network helper @var{helper} to configure the TAP interface and 2268attach it to the bridge. The default network helper executable is 2269@file{/path/to/qemu-bridge-helper} and the default bridge 2270device is @file{br0}. 2271 2272Examples: 2273 2274@example 2275#launch a QEMU instance with the default network helper to 2276#connect a TAP device to bridge br0 2277qemu-system-i386 linux.img -net bridge -net nic,model=virtio 2278@end example 2279 2280@example 2281#launch a QEMU instance with the default network helper to 2282#connect a TAP device to bridge qemubr0 2283qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio 2284@end example 2285 2286@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2287@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2288 2289Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual 2290machine using a TCP socket connection. If @option{listen} is 2291specified, QEMU waits for incoming connections on @var{port} 2292(@var{host} is optional). @option{connect} is used to connect to 2293another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2294specifies an already opened TCP socket. 2295 2296Example: 2297@example 2298# launch a first QEMU instance 2299qemu-system-i386 linux.img \ 2300 -net nic,macaddr=52:54:00:12:34:56 \ 2301 -net socket,listen=:1234 2302# connect the VLAN 0 of this instance to the VLAN 0 2303# of the first instance 2304qemu-system-i386 linux.img \ 2305 -net nic,macaddr=52:54:00:12:34:57 \ 2306 -net socket,connect=127.0.0.1:1234 2307@end example 2308 2309@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2310@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2311 2312Create a VLAN @var{n} shared with another QEMU virtual 2313machines using a UDP multicast socket, effectively making a bus for 2314every QEMU with same multicast address @var{maddr} and @var{port}. 2315NOTES: 2316@enumerate 2317@item 2318Several QEMU can be running on different hosts and share same bus (assuming 2319correct multicast setup for these hosts). 2320@item 2321mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2322@url{http://user-mode-linux.sf.net}. 2323@item 2324Use @option{fd=h} to specify an already opened UDP multicast socket. 2325@end enumerate 2326 2327Example: 2328@example 2329# launch one QEMU instance 2330qemu-system-i386 linux.img \ 2331 -net nic,macaddr=52:54:00:12:34:56 \ 2332 -net socket,mcast=230.0.0.1:1234 2333# launch another QEMU instance on same "bus" 2334qemu-system-i386 linux.img \ 2335 -net nic,macaddr=52:54:00:12:34:57 \ 2336 -net socket,mcast=230.0.0.1:1234 2337# launch yet another QEMU instance on same "bus" 2338qemu-system-i386 linux.img \ 2339 -net nic,macaddr=52:54:00:12:34:58 \ 2340 -net socket,mcast=230.0.0.1:1234 2341@end example 2342 2343Example (User Mode Linux compat.): 2344@example 2345# launch QEMU instance (note mcast address selected 2346# is UML's default) 2347qemu-system-i386 linux.img \ 2348 -net nic,macaddr=52:54:00:12:34:56 \ 2349 -net socket,mcast=239.192.168.1:1102 2350# launch UML 2351/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2352@end example 2353 2354Example (send packets from host's 1.2.3.4): 2355@example 2356qemu-system-i386 linux.img \ 2357 -net nic,macaddr=52:54:00:12:34:56 \ 2358 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2359@end example 2360 2361@item -netdev l2tpv3,id=@var{id},src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}] 2362@itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}] 2363Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular 2364protocol to transport Ethernet (and other Layer 2) data frames between 2365two systems. It is present in routers, firewalls and the Linux kernel 2366(from version 3.3 onwards). 2367 2368This transport allows a VM to communicate to another VM, router or firewall directly. 2369 2370@item src=@var{srcaddr} 2371 source address (mandatory) 2372@item dst=@var{dstaddr} 2373 destination address (mandatory) 2374@item udp 2375 select udp encapsulation (default is ip). 2376@item srcport=@var{srcport} 2377 source udp port. 2378@item dstport=@var{dstport} 2379 destination udp port. 2380@item ipv6 2381 force v6, otherwise defaults to v4. 2382@item rxcookie=@var{rxcookie} 2383@itemx txcookie=@var{txcookie} 2384 Cookies are a weak form of security in the l2tpv3 specification. 2385Their function is mostly to prevent misconfiguration. By default they are 32 2386bit. 2387@item cookie64 2388 Set cookie size to 64 bit instead of the default 32 2389@item counter=off 2390 Force a 'cut-down' L2TPv3 with no counter as in 2391draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2392@item pincounter=on 2393 Work around broken counter handling in peer. This may also help on 2394networks which have packet reorder. 2395@item offset=@var{offset} 2396 Add an extra offset between header and data 2397 2398For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2399on the remote Linux host 1.2.3.4: 2400@example 2401# Setup tunnel on linux host using raw ip as encapsulation 2402# on 1.2.3.4 2403ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2404 encap udp udp_sport 16384 udp_dport 16384 2405ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2406 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2407ifconfig vmtunnel0 mtu 1500 2408ifconfig vmtunnel0 up 2409brctl addif br-lan vmtunnel0 2410 2411 2412# on 4.3.2.1 2413# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2414 2415qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2416 2417 2418@end example 2419 2420@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2421@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2422Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and 2423listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2424and MODE @var{octalmode} to change default ownership and permissions for 2425communication port. This option is only available if QEMU has been compiled 2426with vde support enabled. 2427 2428Example: 2429@example 2430# launch vde switch 2431vde_switch -F -sock /tmp/myswitch 2432# launch QEMU instance 2433qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch 2434@end example 2435 2436@item -netdev hubport,id=@var{id},hubid=@var{hubid} 2437 2438Create a hub port on QEMU "vlan" @var{hubid}. 2439 2440The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single 2441netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the 2442required hub automatically. 2443 2444@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2445 2446Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2447be a unix domain socket backed one. The vhost-user uses a specifically defined 2448protocol to pass vhost ioctl replacement messages to an application on the other 2449end of the socket. On non-MSIX guests, the feature can be forced with 2450@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2451be created for multiqueue vhost-user. 2452 2453Example: 2454@example 2455qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2456 -numa node,memdev=mem \ 2457 -chardev socket,id=chr0,path=/path/to/socket \ 2458 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2459 -device virtio-net-pci,netdev=net0 2460@end example 2461 2462@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}] 2463Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default). 2464At most @var{len} bytes (64k by default) per packet are stored. The file format is 2465libpcap, so it can be analyzed with tools such as tcpdump or Wireshark. 2466Note: For devices created with '-netdev', use '-object filter-dump,...' instead. 2467 2468@item -net none 2469Indicate that no network devices should be configured. It is used to 2470override the default configuration (@option{-net nic -net user}) which 2471is activated if no @option{-net} options are provided. 2472ETEXI 2473 2474STEXI 2475@end table 2476ETEXI 2477DEFHEADING() 2478 2479DEFHEADING(Character device options) 2480STEXI 2481 2482The general form of a character device option is: 2483@table @option 2484ETEXI 2485 2486DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2487 "-chardev help\n" 2488 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2489 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2490 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n" 2491 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n" 2492 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n" 2493 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2494 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2495 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2496 " [,logfile=PATH][,logappend=on|off]\n" 2497 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2498 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2499 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2500 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2501 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2502 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2503#ifdef _WIN32 2504 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2505 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2506#else 2507 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2508 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2509#endif 2510#ifdef CONFIG_BRLAPI 2511 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2512#endif 2513#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2514 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2515 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2516 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2517#endif 2518#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2519 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2520 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2521#endif 2522#if defined(CONFIG_SPICE) 2523 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2524 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2525#endif 2526 , QEMU_ARCH_ALL 2527) 2528 2529STEXI 2530@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}] 2531@findex -chardev 2532Backend is one of: 2533@option{null}, 2534@option{socket}, 2535@option{udp}, 2536@option{msmouse}, 2537@option{vc}, 2538@option{ringbuf}, 2539@option{file}, 2540@option{pipe}, 2541@option{console}, 2542@option{serial}, 2543@option{pty}, 2544@option{stdio}, 2545@option{braille}, 2546@option{tty}, 2547@option{parallel}, 2548@option{parport}, 2549@option{spicevmc}. 2550@option{spiceport}. 2551The specific backend will determine the applicable options. 2552 2553Use "-chardev help" to print all available chardev backend types. 2554 2555All devices must have an id, which can be any string up to 127 characters long. 2556It is used to uniquely identify this device in other command line directives. 2557 2558A character device may be used in multiplexing mode by multiple front-ends. 2559Specify @option{mux=on} to enable this mode. 2560A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2561backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2562If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2563create a multiplexer with your specified ID, and you can then configure multiple 2564front ends to use that chardev ID for their input/output. Up to four different 2565front ends can be connected to a single multiplexed chardev. (Without 2566multiplexing enabled, a chardev can only be used by a single front end.) 2567For instance you could use this to allow a single stdio chardev to be used by 2568two serial ports and the QEMU monitor: 2569 2570@example 2571-chardev stdio,mux=on,id=char0 \ 2572-mon chardev=char0,mode=readline \ 2573-serial chardev:char0 \ 2574-serial chardev:char0 2575@end example 2576 2577You can have more than one multiplexer in a system configuration; for instance 2578you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2579multiplexed between the QEMU monitor and a parallel port: 2580 2581@example 2582-chardev stdio,mux=on,id=char0 \ 2583-mon chardev=char0,mode=readline \ 2584-parallel chardev:char0 \ 2585-chardev tcp,...,mux=on,id=char1 \ 2586-serial chardev:char1 \ 2587-serial chardev:char1 2588@end example 2589 2590When you're using a multiplexed character device, some escape sequences are 2591interpreted in the input. @xref{mux_keys, Keys in the character backend 2592multiplexer}. 2593 2594Note that some other command line options may implicitly create multiplexed 2595character backends; for instance @option{-serial mon:stdio} creates a 2596multiplexed stdio backend connected to the serial port and the QEMU monitor, 2597and @option{-nographic} also multiplexes the console and the monitor to 2598stdio. 2599 2600There is currently no support for multiplexing in the other direction 2601(where a single QEMU front end takes input and output from multiple chardevs). 2602 2603Every backend supports the @option{logfile} option, which supplies the path 2604to a file to record all data transmitted via the backend. The @option{logappend} 2605option controls whether the log file will be truncated or appended to when 2606opened. 2607 2608Further options to each backend are described below. 2609 2610@item -chardev null ,id=@var{id} 2611A void device. This device will not emit any data, and will drop any data it 2612receives. The null backend does not take any options. 2613 2614@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}] 2615 2616Create a two-way stream socket, which can be either a TCP or a unix socket. A 2617unix socket will be created if @option{path} is specified. Behaviour is 2618undefined if TCP options are specified for a unix socket. 2619 2620@option{server} specifies that the socket shall be a listening socket. 2621 2622@option{nowait} specifies that QEMU should not block waiting for a client to 2623connect to a listening socket. 2624 2625@option{telnet} specifies that traffic on the socket should interpret telnet 2626escape sequences. 2627 2628@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2629the remote end goes away. qemu will delay this many seconds and then attempt 2630to reconnect. Zero disables reconnecting, and is the default. 2631 2632@option{tls-creds} requests enablement of the TLS protocol for encryption, 2633and specifies the id of the TLS credentials to use for the handshake. The 2634credentials must be previously created with the @option{-object tls-creds} 2635argument. 2636 2637TCP and unix socket options are given below: 2638 2639@table @option 2640 2641@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay] 2642 2643@option{host} for a listening socket specifies the local address to be bound. 2644For a connecting socket species the remote host to connect to. @option{host} is 2645optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2646 2647@option{port} for a listening socket specifies the local port to be bound. For a 2648connecting socket specifies the port on the remote host to connect to. 2649@option{port} can be given as either a port number or a service name. 2650@option{port} is required. 2651 2652@option{to} is only relevant to listening sockets. If it is specified, and 2653@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2654to and including @option{to} until it succeeds. @option{to} must be specified 2655as a port number. 2656 2657@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2658If neither is specified the socket may use either protocol. 2659 2660@option{nodelay} disables the Nagle algorithm. 2661 2662@item unix options: path=@var{path} 2663 2664@option{path} specifies the local path of the unix socket. @option{path} is 2665required. 2666 2667@end table 2668 2669@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6] 2670 2671Sends all traffic from the guest to a remote host over UDP. 2672 2673@option{host} specifies the remote host to connect to. If not specified it 2674defaults to @code{localhost}. 2675 2676@option{port} specifies the port on the remote host to connect to. @option{port} 2677is required. 2678 2679@option{localaddr} specifies the local address to bind to. If not specified it 2680defaults to @code{0.0.0.0}. 2681 2682@option{localport} specifies the local port to bind to. If not specified any 2683available local port will be used. 2684 2685@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2686If neither is specified the device may use either protocol. 2687 2688@item -chardev msmouse ,id=@var{id} 2689 2690Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2691take any options. 2692 2693@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]] 2694 2695Connect to a QEMU text console. @option{vc} may optionally be given a specific 2696size. 2697 2698@option{width} and @option{height} specify the width and height respectively of 2699the console, in pixels. 2700 2701@option{cols} and @option{rows} specify that the console be sized to fit a text 2702console with the given dimensions. 2703 2704@item -chardev ringbuf ,id=@var{id} [,size=@var{size}] 2705 2706Create a ring buffer with fixed size @option{size}. 2707@var{size} must be a power of two and defaults to @code{64K}. 2708 2709@item -chardev file ,id=@var{id} ,path=@var{path} 2710 2711Log all traffic received from the guest to a file. 2712 2713@option{path} specifies the path of the file to be opened. This file will be 2714created if it does not already exist, and overwritten if it does. @option{path} 2715is required. 2716 2717@item -chardev pipe ,id=@var{id} ,path=@var{path} 2718 2719Create a two-way connection to the guest. The behaviour differs slightly between 2720Windows hosts and other hosts: 2721 2722On Windows, a single duplex pipe will be created at 2723@file{\\.pipe\@option{path}}. 2724 2725On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2726@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2727received by the guest. Data written by the guest can be read from 2728@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2729be present. 2730 2731@option{path} forms part of the pipe path as described above. @option{path} is 2732required. 2733 2734@item -chardev console ,id=@var{id} 2735 2736Send traffic from the guest to QEMU's standard output. @option{console} does not 2737take any options. 2738 2739@option{console} is only available on Windows hosts. 2740 2741@item -chardev serial ,id=@var{id} ,path=@option{path} 2742 2743Send traffic from the guest to a serial device on the host. 2744 2745On Unix hosts serial will actually accept any tty device, 2746not only serial lines. 2747 2748@option{path} specifies the name of the serial device to open. 2749 2750@item -chardev pty ,id=@var{id} 2751 2752Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2753not take any options. 2754 2755@option{pty} is not available on Windows hosts. 2756 2757@item -chardev stdio ,id=@var{id} [,signal=on|off] 2758Connect to standard input and standard output of the QEMU process. 2759 2760@option{signal} controls if signals are enabled on the terminal, that includes 2761exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2762default, use @option{signal=off} to disable it. 2763 2764@item -chardev braille ,id=@var{id} 2765 2766Connect to a local BrlAPI server. @option{braille} does not take any options. 2767 2768@item -chardev tty ,id=@var{id} ,path=@var{path} 2769 2770@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2771DragonFlyBSD hosts. It is an alias for @option{serial}. 2772 2773@option{path} specifies the path to the tty. @option{path} is required. 2774 2775@item -chardev parallel ,id=@var{id} ,path=@var{path} 2776@itemx -chardev parport ,id=@var{id} ,path=@var{path} 2777 2778@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2779 2780Connect to a local parallel port. 2781 2782@option{path} specifies the path to the parallel port device. @option{path} is 2783required. 2784 2785@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2786 2787@option{spicevmc} is only available when spice support is built in. 2788 2789@option{debug} debug level for spicevmc 2790 2791@option{name} name of spice channel to connect to 2792 2793Connect to a spice virtual machine channel, such as vdiport. 2794 2795@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2796 2797@option{spiceport} is only available when spice support is built in. 2798 2799@option{debug} debug level for spicevmc 2800 2801@option{name} name of spice port to connect to 2802 2803Connect to a spice port, allowing a Spice client to handle the traffic 2804identified by a name (preferably a fqdn). 2805ETEXI 2806 2807STEXI 2808@end table 2809ETEXI 2810DEFHEADING() 2811 2812DEFHEADING(Device URL Syntax) 2813STEXI 2814 2815In addition to using normal file images for the emulated storage devices, 2816QEMU can also use networked resources such as iSCSI devices. These are 2817specified using a special URL syntax. 2818 2819@table @option 2820@item iSCSI 2821iSCSI support allows QEMU to access iSCSI resources directly and use as 2822images for the guest storage. Both disk and cdrom images are supported. 2823 2824Syntax for specifying iSCSI LUNs is 2825``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>'' 2826 2827By default qemu will use the iSCSI initiator-name 2828'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command 2829line or a configuration file. 2830 2831Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect 2832stalled requests and force a reestablishment of the session. The timeout 2833is specified in seconds. The default is 0 which means no timeout. Libiscsi 28341.15.0 or greater is required for this feature. 2835 2836Example (without authentication): 2837@example 2838qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \ 2839 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \ 2840 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2841@end example 2842 2843Example (CHAP username/password via URL): 2844@example 2845qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1 2846@end example 2847 2848Example (CHAP username/password via environment variables): 2849@example 2850LIBISCSI_CHAP_USERNAME="user" \ 2851LIBISCSI_CHAP_PASSWORD="password" \ 2852qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2853@end example 2854 2855iSCSI support is an optional feature of QEMU and only available when 2856compiled and linked against libiscsi. 2857ETEXI 2858DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 2859 "-iscsi [user=user][,password=password]\n" 2860 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 2861 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2862 " [,timeout=timeout]\n" 2863 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2864STEXI 2865 2866iSCSI parameters such as username and password can also be specified via 2867a configuration file. See qemu-doc for more information and examples. 2868 2869@item NBD 2870QEMU supports NBD (Network Block Devices) both using TCP protocol as well 2871as Unix Domain Sockets. 2872 2873Syntax for specifying a NBD device using TCP 2874``nbd:<server-ip>:<port>[:exportname=<export>]'' 2875 2876Syntax for specifying a NBD device using Unix Domain Sockets 2877``nbd:unix:<domain-socket>[:exportname=<export>]'' 2878 2879 2880Example for TCP 2881@example 2882qemu-system-i386 --drive file=nbd:192.0.2.1:30000 2883@end example 2884 2885Example for Unix Domain Sockets 2886@example 2887qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket 2888@end example 2889 2890@item SSH 2891QEMU supports SSH (Secure Shell) access to remote disks. 2892 2893Examples: 2894@example 2895qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img 2896qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img 2897@end example 2898 2899Currently authentication must be done using ssh-agent. Other 2900authentication methods may be supported in future. 2901 2902@item Sheepdog 2903Sheepdog is a distributed storage system for QEMU. 2904QEMU supports using either local sheepdog devices or remote networked 2905devices. 2906 2907Syntax for specifying a sheepdog device 2908@example 2909sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag] 2910@end example 2911 2912Example 2913@example 2914qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine 2915@end example 2916 2917See also @url{https://sheepdog.github.io/sheepdog/}. 2918 2919@item GlusterFS 2920GlusterFS is a user space distributed file system. 2921QEMU supports the use of GlusterFS volumes for hosting VM disk images using 2922TCP, Unix Domain Sockets and RDMA transport protocols. 2923 2924Syntax for specifying a VM disk image on GlusterFS volume is 2925@example 2926 2927URI: 2928gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...] 2929 2930JSON: 2931'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...", 2932@ "server":[@{"type":"tcp","host":"...","port":"..."@}, 2933@ @{"type":"unix","socket":"..."@}]@}@}' 2934@end example 2935 2936 2937Example 2938@example 2939URI: 2940qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img, 2941@ file.debug=9,file.logfile=/var/log/qemu-gluster.log 2942 2943JSON: 2944qemu-system-x86_64 'json:@{"driver":"qcow2", 2945@ "file":@{"driver":"gluster", 2946@ "volume":"testvol","path":"a.img", 2947@ "debug":9,"logfile":"/var/log/qemu-gluster.log", 2948@ "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@}, 2949@ @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}' 2950qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img, 2951@ file.debug=9,file.logfile=/var/log/qemu-gluster.log, 2952@ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007, 2953@ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket 2954@end example 2955 2956See also @url{http://www.gluster.org}. 2957 2958@item HTTP/HTTPS/FTP/FTPS 2959QEMU supports read-only access to files accessed over http(s) and ftp(s). 2960 2961Syntax using a single filename: 2962@example 2963<protocol>://[<username>[:<password>]@@]<host>/<path> 2964@end example 2965 2966where: 2967@table @option 2968@item protocol 2969'http', 'https', 'ftp', or 'ftps'. 2970 2971@item username 2972Optional username for authentication to the remote server. 2973 2974@item password 2975Optional password for authentication to the remote server. 2976 2977@item host 2978Address of the remote server. 2979 2980@item path 2981Path on the remote server, including any query string. 2982@end table 2983 2984The following options are also supported: 2985@table @option 2986@item url 2987The full URL when passing options to the driver explicitly. 2988 2989@item readahead 2990The amount of data to read ahead with each range request to the remote server. 2991This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it 2992does not have a suffix, it will be assumed to be in bytes. The value must be a 2993multiple of 512 bytes. It defaults to 256k. 2994 2995@item sslverify 2996Whether to verify the remote server's certificate when connecting over SSL. It 2997can have the value 'on' or 'off'. It defaults to 'on'. 2998 2999@item cookie 3000Send this cookie (it can also be a list of cookies separated by ';') with 3001each outgoing request. Only supported when using protocols such as HTTP 3002which support cookies, otherwise ignored. 3003 3004@item timeout 3005Set the timeout in seconds of the CURL connection. This timeout is the time 3006that CURL waits for a response from the remote server to get the size of the 3007image to be downloaded. If not set, the default timeout of 5 seconds is used. 3008@end table 3009 3010Note that when passing options to qemu explicitly, @option{driver} is the value 3011of <protocol>. 3012 3013Example: boot from a remote Fedora 20 live ISO image 3014@example 3015qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly 3016 3017qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly 3018@end example 3019 3020Example: boot from a remote Fedora 20 cloud image using a local overlay for 3021writes, copy-on-read, and a readahead of 64k 3022@example 3023qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2 3024 3025qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on 3026@end example 3027 3028Example: boot from an image stored on a VMware vSphere server with a self-signed 3029certificate using a local overlay for writes, a readahead of 64k and a timeout 3030of 10 seconds. 3031@example 3032qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2 3033 3034qemu-system-x86_64 -drive file=/tmp/test.qcow2 3035@end example 3036ETEXI 3037 3038STEXI 3039@end table 3040ETEXI 3041 3042DEFHEADING(Bluetooth(R) options) 3043STEXI 3044@table @option 3045ETEXI 3046 3047DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3048 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3049 "-bt hci,host[:id]\n" \ 3050 " use host's HCI with the given name\n" \ 3051 "-bt hci[,vlan=n]\n" \ 3052 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3053 "-bt vhci[,vlan=n]\n" \ 3054 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3055 "-bt device:dev[,vlan=n]\n" \ 3056 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3057 QEMU_ARCH_ALL) 3058STEXI 3059@item -bt hci[...] 3060@findex -bt 3061Defines the function of the corresponding Bluetooth HCI. -bt options 3062are matched with the HCIs present in the chosen machine type. For 3063example when emulating a machine with only one HCI built into it, only 3064the first @code{-bt hci[...]} option is valid and defines the HCI's 3065logic. The Transport Layer is decided by the machine type. Currently 3066the machines @code{n800} and @code{n810} have one HCI and all other 3067machines have none. 3068 3069@anchor{bt-hcis} 3070The following three types are recognized: 3071 3072@table @option 3073@item -bt hci,null 3074(default) The corresponding Bluetooth HCI assumes no internal logic 3075and will not respond to any HCI commands or emit events. 3076 3077@item -bt hci,host[:@var{id}] 3078(@code{bluez} only) The corresponding HCI passes commands / events 3079to / from the physical HCI identified by the name @var{id} (default: 3080@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3081capable systems like Linux. 3082 3083@item -bt hci[,vlan=@var{n}] 3084Add a virtual, standard HCI that will participate in the Bluetooth 3085scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3086VLANs, devices inside a bluetooth network @var{n} can only communicate 3087with other devices in the same network (scatternet). 3088@end table 3089 3090@item -bt vhci[,vlan=@var{n}] 3091(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3092to the host bluetooth stack instead of to the emulated target. This 3093allows the host and target machines to participate in a common scatternet 3094and communicate. Requires the Linux @code{vhci} driver installed. Can 3095be used as following: 3096 3097@example 3098qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3099@end example 3100 3101@item -bt device:@var{dev}[,vlan=@var{n}] 3102Emulate a bluetooth device @var{dev} and place it in network @var{n} 3103(default @code{0}). QEMU can only emulate one type of bluetooth devices 3104currently: 3105 3106@table @option 3107@item keyboard 3108Virtual wireless keyboard implementing the HIDP bluetooth profile. 3109@end table 3110ETEXI 3111 3112STEXI 3113@end table 3114ETEXI 3115DEFHEADING() 3116 3117#ifdef CONFIG_TPM 3118DEFHEADING(TPM device options) 3119 3120DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3121 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3122 " use path to provide path to a character device; default is /dev/tpm0\n" 3123 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3124 " not provided it will be searched for in /sys/class/misc/tpm?/device\n", 3125 QEMU_ARCH_ALL) 3126STEXI 3127 3128The general form of a TPM device option is: 3129@table @option 3130 3131@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] 3132@findex -tpmdev 3133Backend type must be: 3134@option{passthrough}. 3135 3136The specific backend type will determine the applicable options. 3137The @code{-tpmdev} option creates the TPM backend and requires a 3138@code{-device} option that specifies the TPM frontend interface model. 3139 3140Options to each backend are described below. 3141 3142Use 'help' to print all available TPM backend types. 3143@example 3144qemu -tpmdev help 3145@end example 3146 3147@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path} 3148 3149(Linux-host only) Enable access to the host's TPM using the passthrough 3150driver. 3151 3152@option{path} specifies the path to the host's TPM device, i.e., on 3153a Linux host this would be @code{/dev/tpm0}. 3154@option{path} is optional and by default @code{/dev/tpm0} is used. 3155 3156@option{cancel-path} specifies the path to the host TPM device's sysfs 3157entry allowing for cancellation of an ongoing TPM command. 3158@option{cancel-path} is optional and by default QEMU will search for the 3159sysfs entry to use. 3160 3161Some notes about using the host's TPM with the passthrough driver: 3162 3163The TPM device accessed by the passthrough driver must not be 3164used by any other application on the host. 3165 3166Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3167the VM's firmware (BIOS/UEFI) will not be able to initialize the 3168TPM again and may therefore not show a TPM-specific menu that would 3169otherwise allow the user to configure the TPM, e.g., allow the user to 3170enable/disable or activate/deactivate the TPM. 3171Further, if TPM ownership is released from within a VM then the host's TPM 3172will get disabled and deactivated. To enable and activate the 3173TPM again afterwards, the host has to be rebooted and the user is 3174required to enter the firmware's menu to enable and activate the TPM. 3175If the TPM is left disabled and/or deactivated most TPM commands will fail. 3176 3177To create a passthrough TPM use the following two options: 3178@example 3179-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3180@end example 3181Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3182@code{tpmdev=tpm0} in the device option. 3183 3184@end table 3185 3186ETEXI 3187 3188DEFHEADING() 3189 3190#endif 3191 3192DEFHEADING(Linux/Multiboot boot specific) 3193STEXI 3194 3195When using these options, you can use a given Linux or Multiboot 3196kernel without installing it in the disk image. It can be useful 3197for easier testing of various kernels. 3198 3199@table @option 3200ETEXI 3201 3202DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3203 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3204STEXI 3205@item -kernel @var{bzImage} 3206@findex -kernel 3207Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3208or in multiboot format. 3209ETEXI 3210 3211DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3212 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3213STEXI 3214@item -append @var{cmdline} 3215@findex -append 3216Use @var{cmdline} as kernel command line 3217ETEXI 3218 3219DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3220 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3221STEXI 3222@item -initrd @var{file} 3223@findex -initrd 3224Use @var{file} as initial ram disk. 3225 3226@item -initrd "@var{file1} arg=foo,@var{file2}" 3227 3228This syntax is only available with multiboot. 3229 3230Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3231first module. 3232ETEXI 3233 3234DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3235 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3236STEXI 3237@item -dtb @var{file} 3238@findex -dtb 3239Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3240on boot. 3241ETEXI 3242 3243STEXI 3244@end table 3245ETEXI 3246DEFHEADING() 3247 3248DEFHEADING(Debug/Expert options) 3249STEXI 3250@table @option 3251ETEXI 3252 3253DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3254 "-fw_cfg [name=]<name>,file=<file>\n" 3255 " add named fw_cfg entry with contents from file\n" 3256 "-fw_cfg [name=]<name>,string=<str>\n" 3257 " add named fw_cfg entry with contents from string\n", 3258 QEMU_ARCH_ALL) 3259STEXI 3260 3261@item -fw_cfg [name=]@var{name},file=@var{file} 3262@findex -fw_cfg 3263Add named fw_cfg entry with contents from file @var{file}. 3264 3265@item -fw_cfg [name=]@var{name},string=@var{str} 3266Add named fw_cfg entry with contents from string @var{str}. 3267 3268The terminating NUL character of the contents of @var{str} will not be 3269included as part of the fw_cfg item data. To insert contents with 3270embedded NUL characters, you have to use the @var{file} parameter. 3271 3272The fw_cfg entries are passed by QEMU through to the guest. 3273 3274Example: 3275@example 3276 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3277@end example 3278creates an fw_cfg entry named opt/com.mycompany/blob with contents 3279from ./my_blob.bin. 3280 3281ETEXI 3282 3283DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3284 "-serial dev redirect the serial port to char device 'dev'\n", 3285 QEMU_ARCH_ALL) 3286STEXI 3287@item -serial @var{dev} 3288@findex -serial 3289Redirect the virtual serial port to host character device 3290@var{dev}. The default device is @code{vc} in graphical mode and 3291@code{stdio} in non graphical mode. 3292 3293This option can be used several times to simulate up to 4 serial 3294ports. 3295 3296Use @code{-serial none} to disable all serial ports. 3297 3298Available character devices are: 3299@table @option 3300@item vc[:@var{W}x@var{H}] 3301Virtual console. Optionally, a width and height can be given in pixel with 3302@example 3303vc:800x600 3304@end example 3305It is also possible to specify width or height in characters: 3306@example 3307vc:80Cx24C 3308@end example 3309@item pty 3310[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3311@item none 3312No device is allocated. 3313@item null 3314void device 3315@item chardev:@var{id} 3316Use a named character device defined with the @code{-chardev} option. 3317@item /dev/XXX 3318[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3319parameters are set according to the emulated ones. 3320@item /dev/parport@var{N} 3321[Linux only, parallel port only] Use host parallel port 3322@var{N}. Currently SPP and EPP parallel port features can be used. 3323@item file:@var{filename} 3324Write output to @var{filename}. No character can be read. 3325@item stdio 3326[Unix only] standard input/output 3327@item pipe:@var{filename} 3328name pipe @var{filename} 3329@item COM@var{n} 3330[Windows only] Use host serial port @var{n} 3331@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3332This implements UDP Net Console. 3333When @var{remote_host} or @var{src_ip} are not specified 3334they default to @code{0.0.0.0}. 3335When not using a specified @var{src_port} a random port is automatically chosen. 3336 3337If you just want a simple readonly console you can use @code{netcat} or 3338@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3339@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3340will appear in the netconsole session. 3341 3342If you plan to send characters back via netconsole or you want to stop 3343and start QEMU a lot of times, you should have QEMU use the same 3344source port each time by using something like @code{-serial 3345udp::4555@@:4556} to QEMU. Another approach is to use a patched 3346version of netcat which can listen to a TCP port and send and receive 3347characters via udp. If you have a patched version of netcat which 3348activates telnet remote echo and single char transfer, then you can 3349use the following options to set up a netcat redirector to allow 3350telnet on port 5555 to access the QEMU port. 3351@table @code 3352@item QEMU Options: 3353-serial udp::4555@@:4556 3354@item netcat options: 3355-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3356@item telnet options: 3357localhost 5555 3358@end table 3359 3360@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3361The TCP Net Console has two modes of operation. It can send the serial 3362I/O to a location or wait for a connection from a location. By default 3363the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3364the @var{server} option QEMU will wait for a client socket application 3365to connect to the port before continuing, unless the @code{nowait} 3366option was specified. The @code{nodelay} option disables the Nagle buffering 3367algorithm. The @code{reconnect} option only applies if @var{noserver} is 3368set, if the connection goes down it will attempt to reconnect at the 3369given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3370one TCP connection at a time is accepted. You can use @code{telnet} to 3371connect to the corresponding character device. 3372@table @code 3373@item Example to send tcp console to 192.168.0.2 port 4444 3374-serial tcp:192.168.0.2:4444 3375@item Example to listen and wait on port 4444 for connection 3376-serial tcp::4444,server 3377@item Example to not wait and listen on ip 192.168.0.100 port 4444 3378-serial tcp:192.168.0.100:4444,server,nowait 3379@end table 3380 3381@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3382The telnet protocol is used instead of raw tcp sockets. The options 3383work the same as if you had specified @code{-serial tcp}. The 3384difference is that the port acts like a telnet server or client using 3385telnet option negotiation. This will also allow you to send the 3386MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3387sequence. Typically in unix telnet you do it with Control-] and then 3388type "send break" followed by pressing the enter key. 3389 3390@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3391A unix domain socket is used instead of a tcp socket. The option works the 3392same as if you had specified @code{-serial tcp} except the unix domain socket 3393@var{path} is used for connections. 3394 3395@item mon:@var{dev_string} 3396This is a special option to allow the monitor to be multiplexed onto 3397another serial port. The monitor is accessed with key sequence of 3398@key{Control-a} and then pressing @key{c}. 3399@var{dev_string} should be any one of the serial devices specified 3400above. An example to multiplex the monitor onto a telnet server 3401listening on port 4444 would be: 3402@table @code 3403@item -serial mon:telnet::4444,server,nowait 3404@end table 3405When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3406QEMU any more but will be passed to the guest instead. 3407 3408@item braille 3409Braille device. This will use BrlAPI to display the braille output on a real 3410or fake device. 3411 3412@item msmouse 3413Three button serial mouse. Configure the guest to use Microsoft protocol. 3414@end table 3415ETEXI 3416 3417DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3418 "-parallel dev redirect the parallel port to char device 'dev'\n", 3419 QEMU_ARCH_ALL) 3420STEXI 3421@item -parallel @var{dev} 3422@findex -parallel 3423Redirect the virtual parallel port to host device @var{dev} (same 3424devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3425be used to use hardware devices connected on the corresponding host 3426parallel port. 3427 3428This option can be used several times to simulate up to 3 parallel 3429ports. 3430 3431Use @code{-parallel none} to disable all parallel ports. 3432ETEXI 3433 3434DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3435 "-monitor dev redirect the monitor to char device 'dev'\n", 3436 QEMU_ARCH_ALL) 3437STEXI 3438@item -monitor @var{dev} 3439@findex -monitor 3440Redirect the monitor to host device @var{dev} (same devices as the 3441serial port). 3442The default device is @code{vc} in graphical mode and @code{stdio} in 3443non graphical mode. 3444Use @code{-monitor none} to disable the default monitor. 3445ETEXI 3446DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3447 "-qmp dev like -monitor but opens in 'control' mode\n", 3448 QEMU_ARCH_ALL) 3449STEXI 3450@item -qmp @var{dev} 3451@findex -qmp 3452Like -monitor but opens in 'control' mode. 3453ETEXI 3454DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3455 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3456 QEMU_ARCH_ALL) 3457STEXI 3458@item -qmp-pretty @var{dev} 3459@findex -qmp-pretty 3460Like -qmp but uses pretty JSON formatting. 3461ETEXI 3462 3463DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3464 "-mon [chardev=]name[,mode=readline|control]\n", QEMU_ARCH_ALL) 3465STEXI 3466@item -mon [chardev=]name[,mode=readline|control] 3467@findex -mon 3468Setup monitor on chardev @var{name}. 3469ETEXI 3470 3471DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3472 "-debugcon dev redirect the debug console to char device 'dev'\n", 3473 QEMU_ARCH_ALL) 3474STEXI 3475@item -debugcon @var{dev} 3476@findex -debugcon 3477Redirect the debug console to host device @var{dev} (same devices as the 3478serial port). The debug console is an I/O port which is typically port 34790xe9; writing to that I/O port sends output to this device. 3480The default device is @code{vc} in graphical mode and @code{stdio} in 3481non graphical mode. 3482ETEXI 3483 3484DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3485 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3486STEXI 3487@item -pidfile @var{file} 3488@findex -pidfile 3489Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3490from a script. 3491ETEXI 3492 3493DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3494 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3495STEXI 3496@item -singlestep 3497@findex -singlestep 3498Run the emulation in single step mode. 3499ETEXI 3500 3501DEF("S", 0, QEMU_OPTION_S, \ 3502 "-S freeze CPU at startup (use 'c' to start execution)\n", 3503 QEMU_ARCH_ALL) 3504STEXI 3505@item -S 3506@findex -S 3507Do not start CPU at startup (you must type 'c' in the monitor). 3508ETEXI 3509 3510DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3511 "-realtime [mlock=on|off]\n" 3512 " run qemu with realtime features\n" 3513 " mlock=on|off controls mlock support (default: on)\n", 3514 QEMU_ARCH_ALL) 3515STEXI 3516@item -realtime mlock=on|off 3517@findex -realtime 3518Run qemu with realtime features. 3519mlocking qemu and guest memory can be enabled via @option{mlock=on} 3520(enabled by default). 3521ETEXI 3522 3523DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3524 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3525STEXI 3526@item -gdb @var{dev} 3527@findex -gdb 3528Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3529connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3530stdio are reasonable use case. The latter is allowing to start QEMU from 3531within gdb and establish the connection via a pipe: 3532@example 3533(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3534@end example 3535ETEXI 3536 3537DEF("s", 0, QEMU_OPTION_s, \ 3538 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3539 QEMU_ARCH_ALL) 3540STEXI 3541@item -s 3542@findex -s 3543Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3544(@pxref{gdb_usage}). 3545ETEXI 3546 3547DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3548 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3549 QEMU_ARCH_ALL) 3550STEXI 3551@item -d @var{item1}[,...] 3552@findex -d 3553Enable logging of specified items. Use '-d help' for a list of log items. 3554ETEXI 3555 3556DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3557 "-D logfile output log to logfile (default stderr)\n", 3558 QEMU_ARCH_ALL) 3559STEXI 3560@item -D @var{logfile} 3561@findex -D 3562Output log in @var{logfile} instead of to stderr 3563ETEXI 3564 3565DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3566 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3567 QEMU_ARCH_ALL) 3568STEXI 3569@item -dfilter @var{range1}[,...] 3570@findex -dfilter 3571Filter debug output to that relevant to a range of target addresses. The filter 3572spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3573@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3574addresses and sizes required. For example: 3575@example 3576 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3577@end example 3578Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3579the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3580block starting at 0xffffffc00005f000. 3581ETEXI 3582 3583DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3584 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3585 QEMU_ARCH_ALL) 3586STEXI 3587@item -L @var{path} 3588@findex -L 3589Set the directory for the BIOS, VGA BIOS and keymaps. 3590 3591To list all the data directories, use @code{-L help}. 3592ETEXI 3593 3594DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3595 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3596STEXI 3597@item -bios @var{file} 3598@findex -bios 3599Set the filename for the BIOS. 3600ETEXI 3601 3602DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3603 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3604STEXI 3605@item -enable-kvm 3606@findex -enable-kvm 3607Enable KVM full virtualization support. This option is only available 3608if KVM support is enabled when compiling. 3609ETEXI 3610 3611DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \ 3612 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386) 3613STEXI 3614@item -enable-hax 3615@findex -enable-hax 3616Enable HAX (Hardware-based Acceleration eXecution) support. This option 3617is only available if HAX support is enabled when compiling. HAX is only 3618applicable to MAC and Windows platform, and thus does not conflict with 3619KVM. 3620ETEXI 3621 3622DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3623 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3624DEF("xen-create", 0, QEMU_OPTION_xen_create, 3625 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3626 " warning: should not be used when xend is in use\n", 3627 QEMU_ARCH_ALL) 3628DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3629 "-xen-attach attach to existing xen domain\n" 3630 " xend will use this when starting QEMU\n", 3631 QEMU_ARCH_ALL) 3632DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3633 "-xen-domid-restrict restrict set of available xen operations\n" 3634 " to specified domain id. (Does not affect\n" 3635 " xenpv machine type).\n", 3636 QEMU_ARCH_ALL) 3637STEXI 3638@item -xen-domid @var{id} 3639@findex -xen-domid 3640Specify xen guest domain @var{id} (XEN only). 3641@item -xen-create 3642@findex -xen-create 3643Create domain using xen hypercalls, bypassing xend. 3644Warning: should not be used when xend is in use (XEN only). 3645@item -xen-attach 3646@findex -xen-attach 3647Attach to existing xen domain. 3648xend will use this when starting QEMU (XEN only). 3649@findex -xen-domid-restrict 3650Restrict set of available xen operations to specified domain id (XEN only). 3651ETEXI 3652 3653DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3654 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3655STEXI 3656@item -no-reboot 3657@findex -no-reboot 3658Exit instead of rebooting. 3659ETEXI 3660 3661DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3662 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3663STEXI 3664@item -no-shutdown 3665@findex -no-shutdown 3666Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3667This allows for instance switching to monitor to commit changes to the 3668disk image. 3669ETEXI 3670 3671DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3672 "-loadvm [tag|id]\n" \ 3673 " start right away with a saved state (loadvm in monitor)\n", 3674 QEMU_ARCH_ALL) 3675STEXI 3676@item -loadvm @var{file} 3677@findex -loadvm 3678Start right away with a saved state (@code{loadvm} in monitor) 3679ETEXI 3680 3681#ifndef _WIN32 3682DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3683 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3684#endif 3685STEXI 3686@item -daemonize 3687@findex -daemonize 3688Daemonize the QEMU process after initialization. QEMU will not detach from 3689standard IO until it is ready to receive connections on any of its devices. 3690This option is a useful way for external programs to launch QEMU without having 3691to cope with initialization race conditions. 3692ETEXI 3693 3694DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3695 "-option-rom rom load a file, rom, into the option ROM space\n", 3696 QEMU_ARCH_ALL) 3697STEXI 3698@item -option-rom @var{file} 3699@findex -option-rom 3700Load the contents of @var{file} as an option ROM. 3701This option is useful to load things like EtherBoot. 3702ETEXI 3703 3704HXCOMM Silently ignored for compatibility 3705DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3706 3707HXCOMM Options deprecated by -rtc 3708DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3709DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3710 3711DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3712 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3713 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3714 QEMU_ARCH_ALL) 3715 3716STEXI 3717 3718@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3719@findex -rtc 3720Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3721UTC or local time, respectively. @code{localtime} is required for correct date in 3722MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3723format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3724 3725By default the RTC is driven by the host system time. This allows using of the 3726RTC as accurate reference clock inside the guest, specifically if the host 3727time is smoothly following an accurate external reference clock, e.g. via NTP. 3728If you want to isolate the guest time from the host, you can set @option{clock} 3729to @code{rt} instead. To even prevent it from progressing during suspension, 3730you can set it to @code{vm}. 3731 3732Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3733specifically with Windows' ACPI HAL. This option will try to figure out how 3734many timer interrupts were not processed by the Windows guest and will 3735re-inject them. 3736ETEXI 3737 3738DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3739 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3740 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3741 " instruction, enable aligning the host and virtual clocks\n" \ 3742 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3743STEXI 3744@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3745@findex -icount 3746Enable virtual instruction counter. The virtual cpu will execute one 3747instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3748then the virtual cpu speed will be automatically adjusted to keep virtual 3749time within a few seconds of real time. 3750 3751When the virtual cpu is sleeping, the virtual time will advance at default 3752speed unless @option{sleep=on|off} is specified. 3753With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3754instantly whenever the virtual cpu goes to sleep mode and will not advance 3755if no timer is enabled. This behavior give deterministic execution times from 3756the guest point of view. 3757 3758Note that while this option can give deterministic behavior, it does not 3759provide cycle accurate emulation. Modern CPUs contain superscalar out of 3760order cores with complex cache hierarchies. The number of instructions 3761executed often has little or no correlation with actual performance. 3762 3763@option{align=on} will activate the delay algorithm which will try 3764to synchronise the host clock and the virtual clock. The goal is to 3765have a guest running at the real frequency imposed by the shift option. 3766Whenever the guest clock is behind the host clock and if 3767@option{align=on} is specified then we print a message to the user 3768to inform about the delay. 3769Currently this option does not work when @option{shift} is @code{auto}. 3770Note: The sync algorithm will work for those shift values for which 3771the guest clock runs ahead of the host clock. Typically this happens 3772when the shift value is high (how high depends on the host machine). 3773 3774When @option{rr} option is specified deterministic record/replay is enabled. 3775Replay log is written into @var{filename} file in record mode and 3776read from this file in replay mode. 3777 3778Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3779at the start of execution recording. In replay mode this option is used 3780to load the initial VM state. 3781ETEXI 3782 3783DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3784 "-watchdog model\n" \ 3785 " enable virtual hardware watchdog [default=none]\n", 3786 QEMU_ARCH_ALL) 3787STEXI 3788@item -watchdog @var{model} 3789@findex -watchdog 3790Create a virtual hardware watchdog device. Once enabled (by a guest 3791action), the watchdog must be periodically polled by an agent inside 3792the guest or else the guest will be restarted. Choose a model for 3793which your guest has drivers. 3794 3795The @var{model} is the model of hardware watchdog to emulate. Use 3796@code{-watchdog help} to list available hardware models. Only one 3797watchdog can be enabled for a guest. 3798 3799The following models may be available: 3800@table @option 3801@item ib700 3802iBASE 700 is a very simple ISA watchdog with a single timer. 3803@item i6300esb 3804Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3805dual-timer watchdog. 3806@item diag288 3807A virtual watchdog for s390x backed by the diagnose 288 hypercall 3808(currently KVM only). 3809@end table 3810ETEXI 3811 3812DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3813 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \ 3814 " action when watchdog fires [default=reset]\n", 3815 QEMU_ARCH_ALL) 3816STEXI 3817@item -watchdog-action @var{action} 3818@findex -watchdog-action 3819 3820The @var{action} controls what QEMU will do when the watchdog timer 3821expires. 3822The default is 3823@code{reset} (forcefully reset the guest). 3824Other possible actions are: 3825@code{shutdown} (attempt to gracefully shutdown the guest), 3826@code{poweroff} (forcefully poweroff the guest), 3827@code{pause} (pause the guest), 3828@code{debug} (print a debug message and continue), or 3829@code{none} (do nothing). 3830 3831Note that the @code{shutdown} action requires that the guest responds 3832to ACPI signals, which it may not be able to do in the sort of 3833situations where the watchdog would have expired, and thus 3834@code{-watchdog-action shutdown} is not recommended for production use. 3835 3836Examples: 3837 3838@table @code 3839@item -watchdog i6300esb -watchdog-action pause 3840@itemx -watchdog ib700 3841@end table 3842ETEXI 3843 3844DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3845 "-echr chr set terminal escape character instead of ctrl-a\n", 3846 QEMU_ARCH_ALL) 3847STEXI 3848 3849@item -echr @var{numeric_ascii_value} 3850@findex -echr 3851Change the escape character used for switching to the monitor when using 3852monitor and serial sharing. The default is @code{0x01} when using the 3853@code{-nographic} option. @code{0x01} is equal to pressing 3854@code{Control-a}. You can select a different character from the ascii 3855control keys where 1 through 26 map to Control-a through Control-z. For 3856instance you could use the either of the following to change the escape 3857character to Control-t. 3858@table @code 3859@item -echr 0x14 3860@itemx -echr 20 3861@end table 3862ETEXI 3863 3864DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3865 "-virtioconsole c\n" \ 3866 " set virtio console\n", QEMU_ARCH_ALL) 3867STEXI 3868@item -virtioconsole @var{c} 3869@findex -virtioconsole 3870Set virtio console. 3871 3872This option is maintained for backward compatibility. 3873 3874Please use @code{-device virtconsole} for the new way of invocation. 3875ETEXI 3876 3877DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3878 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3879STEXI 3880@item -show-cursor 3881@findex -show-cursor 3882Show cursor. 3883ETEXI 3884 3885DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3886 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3887STEXI 3888@item -tb-size @var{n} 3889@findex -tb-size 3890Set TB size. 3891ETEXI 3892 3893DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3894 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3895 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3896 "-incoming unix:socketpath\n" \ 3897 " prepare for incoming migration, listen on\n" \ 3898 " specified protocol and socket address\n" \ 3899 "-incoming fd:fd\n" \ 3900 "-incoming exec:cmdline\n" \ 3901 " accept incoming migration on given file descriptor\n" \ 3902 " or from given external command\n" \ 3903 "-incoming defer\n" \ 3904 " wait for the URI to be specified via migrate_incoming\n", 3905 QEMU_ARCH_ALL) 3906STEXI 3907@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3908@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3909@findex -incoming 3910Prepare for incoming migration, listen on a given tcp port. 3911 3912@item -incoming unix:@var{socketpath} 3913Prepare for incoming migration, listen on a given unix socket. 3914 3915@item -incoming fd:@var{fd} 3916Accept incoming migration from a given filedescriptor. 3917 3918@item -incoming exec:@var{cmdline} 3919Accept incoming migration as an output from specified external command. 3920 3921@item -incoming defer 3922Wait for the URI to be specified via migrate_incoming. The monitor can 3923be used to change settings (such as migration parameters) prior to issuing 3924the migrate_incoming to allow the migration to begin. 3925ETEXI 3926 3927DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3928 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3929STEXI 3930@item -only-migratable 3931@findex -only-migratable 3932Only allow migratable devices. Devices will not be allowed to enter an 3933unmigratable state. 3934ETEXI 3935 3936DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3937 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3938STEXI 3939@item -nodefaults 3940@findex -nodefaults 3941Don't create default devices. Normally, QEMU sets the default devices like serial 3942port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3943CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3944default devices. 3945ETEXI 3946 3947#ifndef _WIN32 3948DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3949 "-chroot dir chroot to dir just before starting the VM\n", 3950 QEMU_ARCH_ALL) 3951#endif 3952STEXI 3953@item -chroot @var{dir} 3954@findex -chroot 3955Immediately before starting guest execution, chroot to the specified 3956directory. Especially useful in combination with -runas. 3957ETEXI 3958 3959#ifndef _WIN32 3960DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3961 "-runas user change to user id user just before starting the VM\n", 3962 QEMU_ARCH_ALL) 3963#endif 3964STEXI 3965@item -runas @var{user} 3966@findex -runas 3967Immediately before starting guest execution, drop root privileges, switching 3968to the specified user. 3969ETEXI 3970 3971DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3972 "-prom-env variable=value\n" 3973 " set OpenBIOS nvram variables\n", 3974 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3975STEXI 3976@item -prom-env @var{variable}=@var{value} 3977@findex -prom-env 3978Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3979ETEXI 3980DEF("semihosting", 0, QEMU_OPTION_semihosting, 3981 "-semihosting semihosting mode\n", 3982 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3983 QEMU_ARCH_MIPS) 3984STEXI 3985@item -semihosting 3986@findex -semihosting 3987Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 3988ETEXI 3989DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 3990 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 3991 " semihosting configuration\n", 3992QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3993QEMU_ARCH_MIPS) 3994STEXI 3995@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 3996@findex -semihosting-config 3997Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 3998@table @option 3999@item target=@code{native|gdb|auto} 4000Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4001or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4002during debug sessions and @code{native} otherwise. 4003@item arg=@var{str1},arg=@var{str2},... 4004Allows the user to pass input arguments, and can be used multiple times to build 4005up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4006command line is still supported for backward compatibility. If both the 4007@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4008specified, the former is passed to semihosting as it always takes precedence. 4009@end table 4010ETEXI 4011DEF("old-param", 0, QEMU_OPTION_old_param, 4012 "-old-param old param mode\n", QEMU_ARCH_ARM) 4013STEXI 4014@item -old-param 4015@findex -old-param (ARM) 4016Old param mode (ARM only). 4017ETEXI 4018 4019DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4020 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", 4021 QEMU_ARCH_ALL) 4022STEXI 4023@item -sandbox @var{arg} 4024@findex -sandbox 4025Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4026disable it. The default is 'off'. 4027ETEXI 4028 4029DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4030 "-readconfig <file>\n", QEMU_ARCH_ALL) 4031STEXI 4032@item -readconfig @var{file} 4033@findex -readconfig 4034Read device configuration from @var{file}. This approach is useful when you want to spawn 4035QEMU process with many command line options but you don't want to exceed the command line 4036character limit. 4037ETEXI 4038DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4039 "-writeconfig <file>\n" 4040 " read/write config file\n", QEMU_ARCH_ALL) 4041STEXI 4042@item -writeconfig @var{file} 4043@findex -writeconfig 4044Write device configuration to @var{file}. The @var{file} can be either filename to save 4045command line and device configuration into file or dash @code{-}) character to print the 4046output to stdout. This can be later used as input file for @code{-readconfig} option. 4047ETEXI 4048DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, 4049 "-nodefconfig\n" 4050 " do not load default config files at startup\n", 4051 QEMU_ARCH_ALL) 4052STEXI 4053@item -nodefconfig 4054@findex -nodefconfig 4055Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup. 4056The @code{-nodefconfig} option will prevent QEMU from loading any of those config files. 4057ETEXI 4058DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4059 "-no-user-config\n" 4060 " do not load user-provided config files at startup\n", 4061 QEMU_ARCH_ALL) 4062STEXI 4063@item -no-user-config 4064@findex -no-user-config 4065The @code{-no-user-config} option makes QEMU not load any of the user-provided 4066config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config 4067files from @var{datadir}. 4068ETEXI 4069DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4070 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4071 " specify tracing options\n", 4072 QEMU_ARCH_ALL) 4073STEXI 4074HXCOMM This line is not accurate, as some sub-options are backend-specific but 4075HXCOMM HX does not support conditional compilation of text. 4076@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4077@findex -trace 4078@include qemu-option-trace.texi 4079ETEXI 4080 4081HXCOMM Internal use 4082DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4083DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4084 4085#ifdef __linux__ 4086DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4087 "-enable-fips enable FIPS 140-2 compliance\n", 4088 QEMU_ARCH_ALL) 4089#endif 4090STEXI 4091@item -enable-fips 4092@findex -enable-fips 4093Enable FIPS 140-2 compliance mode. 4094ETEXI 4095 4096HXCOMM Deprecated by -machine accel=tcg property 4097DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4098 4099HXCOMM Deprecated by kvm-pit driver properties 4100DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, 4101 "", QEMU_ARCH_I386) 4102 4103HXCOMM Deprecated (ignored) 4104DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386) 4105 4106HXCOMM Deprecated by -machine kernel_irqchip=on|off property 4107DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386) 4108 4109HXCOMM Deprecated (ignored) 4110DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL) 4111 4112DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4113 "-msg timestamp[=on|off]\n" 4114 " change the format of messages\n" 4115 " on|off controls leading timestamps (default:on)\n", 4116 QEMU_ARCH_ALL) 4117STEXI 4118@item -msg timestamp[=on|off] 4119@findex -msg 4120prepend a timestamp to each log message.(default:on) 4121ETEXI 4122 4123DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4124 "-dump-vmstate <file>\n" 4125 " Output vmstate information in JSON format to file.\n" 4126 " Use the scripts/vmstate-static-checker.py file to\n" 4127 " check for possible regressions in migration code\n" 4128 " by comparing two such vmstate dumps.\n", 4129 QEMU_ARCH_ALL) 4130STEXI 4131@item -dump-vmstate @var{file} 4132@findex -dump-vmstate 4133Dump json-encoded vmstate information for current machine type to file 4134in @var{file} 4135ETEXI 4136 4137STEXI 4138@end table 4139ETEXI 4140DEFHEADING() 4141DEFHEADING(Generic object creation) 4142STEXI 4143@table @option 4144ETEXI 4145 4146DEF("object", HAS_ARG, QEMU_OPTION_object, 4147 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4148 " create a new object of type TYPENAME setting properties\n" 4149 " in the order they are specified. Note that the 'id'\n" 4150 " property must be set. These objects are placed in the\n" 4151 " '/objects' path.\n", 4152 QEMU_ARCH_ALL) 4153STEXI 4154@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4155@findex -object 4156Create a new object of type @var{typename} setting properties 4157in the order they are specified. Note that the 'id' 4158property must be set. These objects are placed in the 4159'/objects' path. 4160 4161@table @option 4162 4163@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off} 4164 4165Creates a memory file backend object, which can be used to back 4166the guest RAM with huge pages. The @option{id} parameter is a 4167unique ID that will be used to reference this memory region 4168when configuring the @option{-numa} argument. The @option{size} 4169option provides the size of the memory region, and accepts 4170common suffixes, eg @option{500M}. The @option{mem-path} provides 4171the path to either a shared memory or huge page filesystem mount. 4172The @option{share} boolean option determines whether the memory 4173region is marked as private to QEMU, or shared. The latter allows 4174a co-operating external process to access the QEMU memory region. 4175 4176@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4177 4178Creates a random number generator backend which obtains entropy from 4179a device on the host. The @option{id} parameter is a unique ID that 4180will be used to reference this entropy backend from the @option{virtio-rng} 4181device. The @option{filename} parameter specifies which file to obtain 4182entropy from and if omitted defaults to @option{/dev/random}. 4183 4184@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4185 4186Creates a random number generator backend which obtains entropy from 4187an external daemon running on the host. The @option{id} parameter is 4188a unique ID that will be used to reference this entropy backend from 4189the @option{virtio-rng} device. The @option{chardev} parameter is 4190the unique ID of a character device backend that provides the connection 4191to the RNG daemon. 4192 4193@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4194 4195Creates a TLS anonymous credentials object, which can be used to provide 4196TLS support on network backends. The @option{id} parameter is a unique 4197ID which network backends will use to access the credentials. The 4198@option{endpoint} is either @option{server} or @option{client} depending 4199on whether the QEMU network backend that uses the credentials will be 4200acting as a client or as a server. If @option{verify-peer} is enabled 4201(the default) then once the handshake is completed, the peer credentials 4202will be verified, though this is a no-op for anonymous credentials. 4203 4204The @var{dir} parameter tells QEMU where to find the credential 4205files. For server endpoints, this directory may contain a file 4206@var{dh-params.pem} providing diffie-hellman parameters to use 4207for the TLS server. If the file is missing, QEMU will generate 4208a set of DH parameters at startup. This is a computationally 4209expensive operation that consumes random pool entropy, so it is 4210recommended that a persistent set of parameters be generated 4211upfront and saved. 4212 4213@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off},passwordid=@var{id} 4214 4215Creates a TLS anonymous credentials object, which can be used to provide 4216TLS support on network backends. The @option{id} parameter is a unique 4217ID which network backends will use to access the credentials. The 4218@option{endpoint} is either @option{server} or @option{client} depending 4219on whether the QEMU network backend that uses the credentials will be 4220acting as a client or as a server. If @option{verify-peer} is enabled 4221(the default) then once the handshake is completed, the peer credentials 4222will be verified. With x509 certificates, this implies that the clients 4223must be provided with valid client certificates too. 4224 4225The @var{dir} parameter tells QEMU where to find the credential 4226files. For server endpoints, this directory may contain a file 4227@var{dh-params.pem} providing diffie-hellman parameters to use 4228for the TLS server. If the file is missing, QEMU will generate 4229a set of DH parameters at startup. This is a computationally 4230expensive operation that consumes random pool entropy, so it is 4231recommended that a persistent set of parameters be generated 4232upfront and saved. 4233 4234For x509 certificate credentials the directory will contain further files 4235providing the x509 certificates. The certificates must be stored 4236in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4237@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4238@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4239 4240For the @var{server-key.pem} and @var{client-key.pem} files which 4241contain sensitive private keys, it is possible to use an encrypted 4242version by providing the @var{passwordid} parameter. This provides 4243the ID of a previously created @code{secret} object containing the 4244password for decryption. 4245 4246@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4247 4248Interval @var{t} can't be 0, this filter batches the packet delivery: all 4249packets arriving in a given interval on netdev @var{netdevid} are delayed 4250until the end of the interval. Interval is in microseconds. 4251@option{status} is optional that indicate whether the netfilter is 4252on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4253 4254queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4255 4256@option{all}: the filter is attached both to the receive and the transmit 4257 queue of the netdev (default). 4258 4259@option{rx}: the filter is attached to the receive queue of the netdev, 4260 where it will receive packets sent to the netdev. 4261 4262@option{tx}: the filter is attached to the transmit queue of the netdev, 4263 where it will receive packets sent by the netdev. 4264 4265@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4266 4267filter-mirror on netdev @var{netdevid},mirror net packet to chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will mirror packet with vnet_hdr_len. 4268 4269@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4270 4271filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4272@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4273filter-redirector will redirect packet with vnet_hdr_len. 4274Create a filter-redirector we need to differ outdev id from indev id, id can not 4275be the same. we can just use indev or outdev, but at least one of indev or outdev 4276need to be specified. 4277 4278@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4279 4280Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4281secondary from primary to keep secondary tcp connection,and rewrite 4282tcp packet to primary from secondary make tcp packet can be handled by 4283client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4284 4285usage: 4286colo secondary: 4287-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4288-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4289-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4290 4291@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4292 4293Dump the network traffic on netdev @var{dev} to the file specified by 4294@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4295The file format is libpcap, so it can be analyzed with tools such as tcpdump 4296or Wireshark. 4297 4298@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support] 4299 4300Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4301secondary packet. If the packets are same, we will output primary 4302packet to outdev@var{chardevid}, else we will notify colo-frame 4303do checkpoint and send primary packet to outdev@var{chardevid}. 4304if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len. 4305 4306we must use it with the help of filter-mirror and filter-redirector. 4307 4308@example 4309 4310primary: 4311-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4312-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4313-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4314-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4315-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4316-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4317-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4318-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4319-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4320-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4321-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4322-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0 4323 4324secondary: 4325-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4326-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4327-chardev socket,id=red0,host=3.3.3.3,port=9003 4328-chardev socket,id=red1,host=3.3.3.3,port=9004 4329-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4330-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4331 4332@end example 4333 4334If you want to know the detail of above command line, you can read 4335the colo-compare git log. 4336 4337@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4338 4339Creates a cryptodev backend which executes crypto opreation from 4340the QEMU cipher APIS. The @var{id} parameter is 4341a unique ID that will be used to reference this cryptodev backend from 4342the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4343which specify the queue number of cryptodev backend, the default of 4344@var{queues} is 1. 4345 4346@example 4347 4348 # qemu-system-x86_64 \ 4349 [...] \ 4350 -object cryptodev-backend-builtin,id=cryptodev0 \ 4351 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4352 [...] 4353@end example 4354 4355@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4356@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4357 4358Defines a secret to store a password, encryption key, or some other sensitive 4359data. The sensitive data can either be passed directly via the @var{data} 4360parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4361parameter is insecure unless the sensitive data is encrypted. 4362 4363The sensitive data can be provided in raw format (the default), or base64. 4364When encoded as JSON, the raw format only supports valid UTF-8 characters, 4365so base64 is recommended for sending binary data. QEMU will convert from 4366which ever format is provided to the format it needs internally. eg, an 4367RBD password can be provided in raw format, even though it will be base64 4368encoded when passed onto the RBD sever. 4369 4370For added protection, it is possible to encrypt the data associated with 4371a secret using the AES-256-CBC cipher. Use of encryption is indicated 4372by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4373parameter provides the ID of a previously defined secret that contains 4374the AES-256 decryption key. This key should be 32-bytes long and be 4375base64 encoded. The @var{iv} parameter provides the random initialization 4376vector used for encryption of this particular secret and should be a 4377base64 encrypted string of the 16-byte IV. 4378 4379The simplest (insecure) usage is to provide the secret inline 4380 4381@example 4382 4383 # $QEMU -object secret,id=sec0,data=letmein,format=raw 4384 4385@end example 4386 4387The simplest secure usage is to provide the secret via a file 4388 4389 # printf "letmein" > mypasswd.txt 4390 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 4391 4392For greater security, AES-256-CBC should be used. To illustrate usage, 4393consider the openssl command line tool which can encrypt the data. Note 4394that when encrypting, the plaintext must be padded to the cipher block 4395size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4396 4397First a master key needs to be created in base64 encoding: 4398 4399@example 4400 # openssl rand -base64 32 > key.b64 4401 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4402@end example 4403 4404Each secret to be encrypted needs to have a random initialization vector 4405generated. These do not need to be kept secret 4406 4407@example 4408 # openssl rand -base64 16 > iv.b64 4409 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4410@end example 4411 4412The secret to be defined can now be encrypted, in this case we're 4413telling openssl to base64 encode the result, but it could be left 4414as raw bytes if desired. 4415 4416@example 4417 # SECRET=$(printf "letmein" | 4418 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4419@end example 4420 4421When launching QEMU, create a master secret pointing to @code{key.b64} 4422and specify that to be used to decrypt the user password. Pass the 4423contents of @code{iv.b64} to the second secret 4424 4425@example 4426 # $QEMU \ 4427 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4428 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4429 data=$SECRET,iv=$(<iv.b64) 4430@end example 4431 4432@end table 4433 4434ETEXI 4435 4436 4437HXCOMM This is the last statement. Insert new options before this line! 4438STEXI 4439@end table 4440ETEXI 4441
