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, tcg (default: tcg)\n" 35 " kernel_irqchip=on|off controls accelerated irqchip support\n" 36 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" 37 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 38 " kvm_shadow_mem=size of KVM shadow MMU\n" 39 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 40 " mem-merge=on|off controls memory merge support (default: on)\n" 41 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n" 42 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 43 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 44 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 45 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 46 " nvdimm=on|off controls NVDIMM support (default=off)\n" 47 " enforce-config-section=on|off enforce configuration section migration (default=off)\n", 48 QEMU_ARCH_ALL) 49STEXI 50@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 51@findex -machine 52Select the emulated machine by @var{name}. Use @code{-machine help} to list 53available machines. Supported machine properties are: 54@table @option 55@item accel=@var{accels1}[:@var{accels2}[:...]] 56This is used to enable an accelerator. Depending on the target architecture, 57kvm, xen, or tcg can be available. By default, tcg is used. If there is more 58than one accelerator specified, the next one is used if the previous one fails 59to initialize. 60@item kernel_irqchip=on|off 61Controls in-kernel irqchip support for the chosen accelerator when available. 62@item gfx_passthru=on|off 63Enables IGD GFX passthrough support for the chosen machine when available. 64@item vmport=on|off|auto 65Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 66value based on accel. For accel=xen the default is off otherwise the default 67is on. 68@item kvm_shadow_mem=size 69Defines the size of the KVM shadow MMU. 70@item dump-guest-core=on|off 71Include guest memory in a core dump. The default is on. 72@item mem-merge=on|off 73Enables or disables memory merge support. This feature, when supported by 74the host, de-duplicates identical memory pages among VMs instances 75(enabled by default). 76@item iommu=on|off 77Enables or disables emulated Intel IOMMU (VT-d) support. The default is off. 78@item aes-key-wrap=on|off 79Enables or disables AES key wrapping support on s390-ccw hosts. This feature 80controls whether AES wrapping keys will be created to allow 81execution of AES cryptographic functions. The default is on. 82@item dea-key-wrap=on|off 83Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 84controls whether DEA wrapping keys will be created to allow 85execution of DEA cryptographic functions. The default is on. 86@item nvdimm=on|off 87Enables or disables NVDIMM support. The default is off. 88@end table 89ETEXI 90 91HXCOMM Deprecated by -machine 92DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 93 94DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 95 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 96STEXI 97@item -cpu @var{model} 98@findex -cpu 99Select CPU model (@code{-cpu help} for list and additional feature selection) 100ETEXI 101 102DEF("smp", HAS_ARG, QEMU_OPTION_smp, 103 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 104 " set the number of CPUs to 'n' [default=1]\n" 105 " maxcpus= maximum number of total cpus, including\n" 106 " offline CPUs for hotplug, etc\n" 107 " cores= number of CPU cores on one socket\n" 108 " threads= number of threads on one CPU core\n" 109 " sockets= number of discrete sockets in the system\n", 110 QEMU_ARCH_ALL) 111STEXI 112@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 113@findex -smp 114Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 115CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 116to 4. 117For the PC target, the number of @var{cores} per socket, the number 118of @var{threads} per cores and the total number of @var{sockets} can be 119specified. Missing values will be computed. If any on the three values is 120given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 121specifies the maximum number of hotpluggable CPUs. 122ETEXI 123 124DEF("numa", HAS_ARG, QEMU_OPTION_numa, 125 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n" 126 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL) 127STEXI 128@item -numa node[,mem=@var{size}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 129@itemx -numa node[,memdev=@var{id}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 130@findex -numa 131Simulate a multi node NUMA system. If @samp{mem}, @samp{memdev} 132and @samp{cpus} are omitted, resources are split equally. Also, note 133that the -@option{numa} option doesn't allocate any of the specified 134resources. That is, it just assigns existing resources to NUMA nodes. This 135means that one still has to use the @option{-m}, @option{-smp} options 136to allocate RAM and VCPUs respectively, and possibly @option{-object} 137to specify the memory backend for the @samp{memdev} suboption. 138 139@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one 140node uses @samp{memdev}, all of them have to use it. 141ETEXI 142 143DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 144 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 145 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 146STEXI 147@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 148@findex -add-fd 149 150Add a file descriptor to an fd set. Valid options are: 151 152@table @option 153@item fd=@var{fd} 154This option defines the file descriptor of which a duplicate is added to fd set. 155The file descriptor cannot be stdin, stdout, or stderr. 156@item set=@var{set} 157This option defines the ID of the fd set to add the file descriptor to. 158@item opaque=@var{opaque} 159This option defines a free-form string that can be used to describe @var{fd}. 160@end table 161 162You can open an image using pre-opened file descriptors from an fd set: 163@example 164qemu-system-i386 165-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 166-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 167-drive file=/dev/fdset/2,index=0,media=disk 168@end example 169ETEXI 170 171DEF("set", HAS_ARG, QEMU_OPTION_set, 172 "-set group.id.arg=value\n" 173 " set <arg> parameter for item <id> of type <group>\n" 174 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 175STEXI 176@item -set @var{group}.@var{id}.@var{arg}=@var{value} 177@findex -set 178Set parameter @var{arg} for item @var{id} of type @var{group}\n" 179ETEXI 180 181DEF("global", HAS_ARG, QEMU_OPTION_global, 182 "-global driver.property=value\n" 183 "-global driver=driver,property=property,value=value\n" 184 " set a global default for a driver property\n", 185 QEMU_ARCH_ALL) 186STEXI 187@item -global @var{driver}.@var{prop}=@var{value} 188@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 189@findex -global 190Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 191 192@example 193qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk 194@end example 195 196In particular, you can use this to set driver properties for devices which are 197created automatically by the machine model. To create a device which is not 198created automatically and set properties on it, use -@option{device}. 199 200-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 201driver=@var{driver},property=@var{prop},value=@var{value}. The 202longhand syntax works even when @var{driver} contains a dot. 203ETEXI 204 205DEF("boot", HAS_ARG, QEMU_OPTION_boot, 206 "-boot [order=drives][,once=drives][,menu=on|off]\n" 207 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 208 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 209 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 210 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 211 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 212 QEMU_ARCH_ALL) 213STEXI 214@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] 215@findex -boot 216Specify boot order @var{drives} as a string of drive letters. Valid 217drive letters depend on the target architecture. The x86 PC uses: a, b 218(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 219from network adapter 1-4), hard disk boot is the default. To apply a 220particular boot order only on the first startup, specify it via 221@option{once}. 222 223Interactive boot menus/prompts can be enabled via @option{menu=on} as far 224as firmware/BIOS supports them. The default is non-interactive boot. 225 226A splash picture could be passed to bios, enabling user to show it as logo, 227when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 228supports them. Currently Seabios for X86 system support it. 229limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 230format(true color). The resolution should be supported by the SVGA mode, so 231the recommended is 320x240, 640x480, 800x640. 232 233A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 234when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 235reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 236system support it. 237 238Do strict boot via @option{strict=on} as far as firmware/BIOS 239supports it. This only effects when boot priority is changed by 240bootindex options. The default is non-strict boot. 241 242@example 243# try to boot from network first, then from hard disk 244qemu-system-i386 -boot order=nc 245# boot from CD-ROM first, switch back to default order after reboot 246qemu-system-i386 -boot once=d 247# boot with a splash picture for 5 seconds. 248qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 249@end example 250 251Note: The legacy format '-boot @var{drives}' is still supported but its 252use is discouraged as it may be removed from future versions. 253ETEXI 254 255DEF("m", HAS_ARG, QEMU_OPTION_m, 256 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n" 257 " configure guest RAM\n" 258 " size: initial amount of guest memory\n" 259 " slots: number of hotplug slots (default: none)\n" 260 " maxmem: maximum amount of guest memory (default: none)\n" 261 "NOTE: Some architectures might enforce a specific granularity\n", 262 QEMU_ARCH_ALL) 263STEXI 264@item -m [size=]@var{megs}[,slots=n,maxmem=size] 265@findex -m 266Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 267Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 268megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 269could be used to set amount of hotpluggable memory slots and maximum amount of 270memory. Note that @var{maxmem} must be aligned to the page size. 271 272For example, the following command-line sets the guest startup RAM size to 2731GB, creates 3 slots to hotplug additional memory and sets the maximum 274memory the guest can reach to 4GB: 275 276@example 277qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 278@end example 279 280If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 281be enabled and the guest startup RAM will never increase. 282ETEXI 283 284DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 285 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 286STEXI 287@item -mem-path @var{path} 288@findex -mem-path 289Allocate guest RAM from a temporarily created file in @var{path}. 290ETEXI 291 292DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 293 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 294 QEMU_ARCH_ALL) 295STEXI 296@item -mem-prealloc 297@findex -mem-prealloc 298Preallocate memory when using -mem-path. 299ETEXI 300 301DEF("k", HAS_ARG, QEMU_OPTION_k, 302 "-k language use keyboard layout (for example 'fr' for French)\n", 303 QEMU_ARCH_ALL) 304STEXI 305@item -k @var{language} 306@findex -k 307Use keyboard layout @var{language} (for example @code{fr} for 308French). This option is only needed where it is not easy to get raw PC 309keycodes (e.g. on Macs, with some X11 servers or with a VNC 310display). You don't normally need to use it on PC/Linux or PC/Windows 311hosts. 312 313The available layouts are: 314@example 315ar de-ch es fo fr-ca hu ja mk no pt-br sv 316da en-gb et fr fr-ch is lt nl pl ru th 317de en-us fi fr-be hr it lv nl-be pt sl tr 318@end example 319 320The default is @code{en-us}. 321ETEXI 322 323 324DEF("audio-help", 0, QEMU_OPTION_audio_help, 325 "-audio-help print list of audio drivers and their options\n", 326 QEMU_ARCH_ALL) 327STEXI 328@item -audio-help 329@findex -audio-help 330Will show the audio subsystem help: list of drivers, tunable 331parameters. 332ETEXI 333 334DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 335 "-soundhw c1,... enable audio support\n" 336 " and only specified sound cards (comma separated list)\n" 337 " use '-soundhw help' to get the list of supported cards\n" 338 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 339STEXI 340@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 341@findex -soundhw 342Enable audio and selected sound hardware. Use 'help' to print all 343available sound hardware. 344 345@example 346qemu-system-i386 -soundhw sb16,adlib disk.img 347qemu-system-i386 -soundhw es1370 disk.img 348qemu-system-i386 -soundhw ac97 disk.img 349qemu-system-i386 -soundhw hda disk.img 350qemu-system-i386 -soundhw all disk.img 351qemu-system-i386 -soundhw help 352@end example 353 354Note that Linux's i810_audio OSS kernel (for AC97) module might 355require manually specifying clocking. 356 357@example 358modprobe i810_audio clocking=48000 359@end example 360ETEXI 361 362DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 363 "-balloon none disable balloon device\n" 364 "-balloon virtio[,addr=str]\n" 365 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL) 366STEXI 367@item -balloon none 368@findex -balloon 369Disable balloon device. 370@item -balloon virtio[,addr=@var{addr}] 371Enable virtio balloon device (default), optionally with PCI address 372@var{addr}. 373ETEXI 374 375DEF("device", HAS_ARG, QEMU_OPTION_device, 376 "-device driver[,prop[=value][,...]]\n" 377 " add device (based on driver)\n" 378 " prop=value,... sets driver properties\n" 379 " use '-device help' to print all possible drivers\n" 380 " use '-device driver,help' to print all possible properties\n", 381 QEMU_ARCH_ALL) 382STEXI 383@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 384@findex -device 385Add device @var{driver}. @var{prop}=@var{value} sets driver 386properties. Valid properties depend on the driver. To get help on 387possible drivers and properties, use @code{-device help} and 388@code{-device @var{driver},help}. 389 390Some drivers are: 391@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}] 392 393Add an IPMI BMC. This is a simulation of a hardware management 394interface processor that normally sits on a system. It provides 395a watchdog and the ability to reset and power control the system. 396You need to connect this to an IPMI interface to make it useful 397 398The IPMI slave address to use for the BMC. The default is 0x20. 399This address is the BMC's address on the I2C network of management 400controllers. If you don't know what this means, it is safe to ignore 401it. 402 403@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 404 405Add a connection to an external IPMI BMC simulator. Instead of 406locally emulating the BMC like the above item, instead connect 407to an external entity that provides the IPMI services. 408 409A connection is made to an external BMC simulator. If you do this, it 410is strongly recommended that you use the "reconnect=" chardev option 411to reconnect to the simulator if the connection is lost. Note that if 412this is not used carefully, it can be a security issue, as the 413interface has the ability to send resets, NMIs, and power off the VM. 414It's best if QEMU makes a connection to an external simulator running 415on a secure port on localhost, so neither the simulator nor QEMU is 416exposed to any outside network. 417 418See the "lanserv/README.vm" file in the OpenIPMI library for more 419details on the external interface. 420 421@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 422 423Add a KCS IPMI interafce on the ISA bus. This also adds a 424corresponding ACPI and SMBIOS entries, if appropriate. 425 426@table @option 427@item bmc=@var{id} 428The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 429@item ioport=@var{val} 430Define the I/O address of the interface. The default is 0xca0 for KCS. 431@item irq=@var{val} 432Define the interrupt to use. The default is 5. To disable interrupts, 433set this to 0. 434@end table 435 436@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 437 438Like the KCS interface, but defines a BT interface. The default port is 4390xe4 and the default interrupt is 5. 440 441ETEXI 442 443DEF("name", HAS_ARG, QEMU_OPTION_name, 444 "-name string1[,process=string2][,debug-threads=on|off]\n" 445 " set the name of the guest\n" 446 " string1 sets the window title and string2 the process name (on Linux)\n" 447 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 448 " NOTE: The thread names are for debugging and not a stable API.\n", 449 QEMU_ARCH_ALL) 450STEXI 451@item -name @var{name} 452@findex -name 453Sets the @var{name} of the guest. 454This name will be displayed in the SDL window caption. 455The @var{name} will also be used for the VNC server. 456Also optionally set the top visible process name in Linux. 457Naming of individual threads can also be enabled on Linux to aid debugging. 458ETEXI 459 460DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 461 "-uuid %08x-%04x-%04x-%04x-%012x\n" 462 " specify machine UUID\n", QEMU_ARCH_ALL) 463STEXI 464@item -uuid @var{uuid} 465@findex -uuid 466Set system UUID. 467ETEXI 468 469STEXI 470@end table 471ETEXI 472DEFHEADING() 473 474DEFHEADING(Block device options:) 475STEXI 476@table @option 477ETEXI 478 479DEF("fda", HAS_ARG, QEMU_OPTION_fda, 480 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 481DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 482STEXI 483@item -fda @var{file} 484@itemx -fdb @var{file} 485@findex -fda 486@findex -fdb 487Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 488ETEXI 489 490DEF("hda", HAS_ARG, QEMU_OPTION_hda, 491 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 492DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 493DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 494 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 495DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 496STEXI 497@item -hda @var{file} 498@itemx -hdb @var{file} 499@itemx -hdc @var{file} 500@itemx -hdd @var{file} 501@findex -hda 502@findex -hdb 503@findex -hdc 504@findex -hdd 505Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 506ETEXI 507 508DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 509 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 510 QEMU_ARCH_ALL) 511STEXI 512@item -cdrom @var{file} 513@findex -cdrom 514Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 515@option{-cdrom} at the same time). You can use the host CD-ROM by 516using @file{/dev/cdrom} as filename (@pxref{host_drives}). 517ETEXI 518 519DEF("drive", HAS_ARG, QEMU_OPTION_drive, 520 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 521 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n" 522 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 523 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n" 524 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 525 " [,readonly=on|off][,copy-on-read=on|off]\n" 526 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 527 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 528 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 529 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 530 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 531 " [[,iops_size=is]]\n" 532 " [[,group=g]]\n" 533 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 534STEXI 535@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 536@findex -drive 537 538Define a new drive. Valid options are: 539 540@table @option 541@item file=@var{file} 542This option defines which disk image (@pxref{disk_images}) to use with 543this drive. If the filename contains comma, you must double it 544(for instance, "file=my,,file" to use file "my,file"). 545 546Special files such as iSCSI devices can be specified using protocol 547specific URLs. See the section for "Device URL Syntax" for more information. 548@item if=@var{interface} 549This option defines on which type on interface the drive is connected. 550Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio. 551@item bus=@var{bus},unit=@var{unit} 552These options define where is connected the drive by defining the bus number and 553the unit id. 554@item index=@var{index} 555This option defines where is connected the drive by using an index in the list 556of available connectors of a given interface type. 557@item media=@var{media} 558This option defines the type of the media: disk or cdrom. 559@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}] 560These options have the same definition as they have in @option{-hdachs}. 561@item snapshot=@var{snapshot} 562@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 563(see @option{-snapshot}). 564@item cache=@var{cache} 565@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data. 566@item aio=@var{aio} 567@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 568@item discard=@var{discard} 569@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap}) requests are ignored or passed to the filesystem. Some machine types may not support discard requests. 570@item format=@var{format} 571Specify which disk @var{format} will be used rather than detecting 572the format. Can be used to specifiy format=raw to avoid interpreting 573an untrusted format header. 574@item serial=@var{serial} 575This option specifies the serial number to assign to the device. 576@item addr=@var{addr} 577Specify the controller's PCI address (if=virtio only). 578@item werror=@var{action},rerror=@var{action} 579Specify which @var{action} to take on write and read errors. Valid actions are: 580"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 581"report" (report the error to the guest), "enospc" (pause QEMU only if the 582host disk is full; report the error to the guest otherwise). 583The default setting is @option{werror=enospc} and @option{rerror=report}. 584@item readonly 585Open drive @option{file} as read-only. Guest write attempts will fail. 586@item copy-on-read=@var{copy-on-read} 587@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 588file sectors into the image file. 589@item detect-zeroes=@var{detect-zeroes} 590@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 591conversion of plain zero writes by the OS to driver specific optimized 592zero write commands. You may even choose "unmap" if @var{discard} is set 593to "unmap" to allow a zero write to be converted to an UNMAP operation. 594@end table 595 596By default, the @option{cache=writeback} mode is used. It will report data 597writes as completed as soon as the data is present in the host page cache. 598This is safe as long as your guest OS makes sure to correctly flush disk caches 599where needed. If your guest OS does not handle volatile disk write caches 600correctly and your host crashes or loses power, then the guest may experience 601data corruption. 602 603For such guests, you should consider using @option{cache=writethrough}. This 604means that the host page cache will be used to read and write data, but write 605notification will be sent to the guest only after QEMU has made sure to flush 606each write to the disk. Be aware that this has a major impact on performance. 607 608The host page cache can be avoided entirely with @option{cache=none}. This will 609attempt to do disk IO directly to the guest's memory. QEMU may still perform 610an internal copy of the data. Note that this is considered a writeback mode and 611the guest OS must handle the disk write cache correctly in order to avoid data 612corruption on host crashes. 613 614The host page cache can be avoided while only sending write notifications to 615the guest when the data has been flushed to the disk using 616@option{cache=directsync}. 617 618In case you don't care about data integrity over host failures, use 619@option{cache=unsafe}. This option tells QEMU that it never needs to write any 620data to the disk but can instead keep things in cache. If anything goes wrong, 621like your host losing power, the disk storage getting disconnected accidentally, 622etc. your image will most probably be rendered unusable. When using 623the @option{-snapshot} option, unsafe caching is always used. 624 625Copy-on-read avoids accessing the same backing file sectors repeatedly and is 626useful when the backing file is over a slow network. By default copy-on-read 627is off. 628 629Instead of @option{-cdrom} you can use: 630@example 631qemu-system-i386 -drive file=file,index=2,media=cdrom 632@end example 633 634Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 635use: 636@example 637qemu-system-i386 -drive file=file,index=0,media=disk 638qemu-system-i386 -drive file=file,index=1,media=disk 639qemu-system-i386 -drive file=file,index=2,media=disk 640qemu-system-i386 -drive file=file,index=3,media=disk 641@end example 642 643You can open an image using pre-opened file descriptors from an fd set: 644@example 645qemu-system-i386 646-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 647-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 648-drive file=/dev/fdset/2,index=0,media=disk 649@end example 650 651You can connect a CDROM to the slave of ide0: 652@example 653qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 654@end example 655 656If you don't specify the "file=" argument, you define an empty drive: 657@example 658qemu-system-i386 -drive if=ide,index=1,media=cdrom 659@end example 660 661You can connect a SCSI disk with unit ID 6 on the bus #0: 662@example 663qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6 664@end example 665 666Instead of @option{-fda}, @option{-fdb}, you can use: 667@example 668qemu-system-i386 -drive file=file,index=0,if=floppy 669qemu-system-i386 -drive file=file,index=1,if=floppy 670@end example 671 672By default, @var{interface} is "ide" and @var{index} is automatically 673incremented: 674@example 675qemu-system-i386 -drive file=a -drive file=b" 676@end example 677is interpreted like: 678@example 679qemu-system-i386 -hda a -hdb b 680@end example 681ETEXI 682 683DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 684 "-mtdblock file use 'file' as on-board Flash memory image\n", 685 QEMU_ARCH_ALL) 686STEXI 687@item -mtdblock @var{file} 688@findex -mtdblock 689Use @var{file} as on-board Flash memory image. 690ETEXI 691 692DEF("sd", HAS_ARG, QEMU_OPTION_sd, 693 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 694STEXI 695@item -sd @var{file} 696@findex -sd 697Use @var{file} as SecureDigital card image. 698ETEXI 699 700DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 701 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 702STEXI 703@item -pflash @var{file} 704@findex -pflash 705Use @var{file} as a parallel flash image. 706ETEXI 707 708DEF("snapshot", 0, QEMU_OPTION_snapshot, 709 "-snapshot write to temporary files instead of disk image files\n", 710 QEMU_ARCH_ALL) 711STEXI 712@item -snapshot 713@findex -snapshot 714Write to temporary files instead of disk image files. In this case, 715the raw disk image you use is not written back. You can however force 716the write back by pressing @key{C-a s} (@pxref{disk_images}). 717ETEXI 718 719DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \ 720 "-hdachs c,h,s[,t]\n" \ 721 " force hard disk 0 physical geometry and the optional BIOS\n" \ 722 " translation (t=none or lba) (usually QEMU can guess them)\n", 723 QEMU_ARCH_ALL) 724STEXI 725@item -hdachs @var{c},@var{h},@var{s},[,@var{t}] 726@findex -hdachs 727Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <= 728@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS 729translation mode (@var{t}=none, lba or auto). Usually QEMU can guess 730all those parameters. This option is useful for old MS-DOS disk 731images. 732ETEXI 733 734DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 735 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 736 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 737 QEMU_ARCH_ALL) 738 739STEXI 740 741@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}] 742@findex -fsdev 743Define a new file system device. Valid options are: 744@table @option 745@item @var{fsdriver} 746This option specifies the fs driver backend to use. 747Currently "local", "handle" and "proxy" file system drivers are supported. 748@item id=@var{id} 749Specifies identifier for this device 750@item path=@var{path} 751Specifies the export path for the file system device. Files under 752this path will be available to the 9p client on the guest. 753@item security_model=@var{security_model} 754Specifies the security model to be used for this export path. 755Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 756In "passthrough" security model, files are stored using the same 757credentials as they are created on the guest. This requires QEMU 758to run as root. In "mapped-xattr" security model, some of the file 759attributes like uid, gid, mode bits and link target are stored as 760file attributes. For "mapped-file" these attributes are stored in the 761hidden .virtfs_metadata directory. Directories exported by this security model cannot 762interact with other unix tools. "none" security model is same as 763passthrough except the sever won't report failures if it fails to 764set file attributes like ownership. Security model is mandatory 765only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 766security model as a parameter. 767@item writeout=@var{writeout} 768This is an optional argument. The only supported value is "immediate". 769This means that host page cache will be used to read and write data but 770write notification will be sent to the guest only when the data has been 771reported as written by the storage subsystem. 772@item readonly 773Enables exporting 9p share as a readonly mount for guests. By default 774read-write access is given. 775@item socket=@var{socket} 776Enables proxy filesystem driver to use passed socket file for communicating 777with virtfs-proxy-helper 778@item sock_fd=@var{sock_fd} 779Enables proxy filesystem driver to use passed socket descriptor for 780communicating with virtfs-proxy-helper. Usually a helper like libvirt 781will create socketpair and pass one of the fds as sock_fd 782@end table 783 784-fsdev option is used along with -device driver "virtio-9p-pci". 785@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 786Options for virtio-9p-pci driver are: 787@table @option 788@item fsdev=@var{id} 789Specifies the id value specified along with -fsdev option 790@item mount_tag=@var{mount_tag} 791Specifies the tag name to be used by the guest to mount this export point 792@end table 793 794ETEXI 795 796DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 797 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 798 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 799 QEMU_ARCH_ALL) 800 801STEXI 802 803@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}] 804@findex -virtfs 805 806The general form of a Virtual File system pass-through options are: 807@table @option 808@item @var{fsdriver} 809This option specifies the fs driver backend to use. 810Currently "local", "handle" and "proxy" file system drivers are supported. 811@item id=@var{id} 812Specifies identifier for this device 813@item path=@var{path} 814Specifies the export path for the file system device. Files under 815this path will be available to the 9p client on the guest. 816@item security_model=@var{security_model} 817Specifies the security model to be used for this export path. 818Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 819In "passthrough" security model, files are stored using the same 820credentials as they are created on the guest. This requires QEMU 821to run as root. In "mapped-xattr" security model, some of the file 822attributes like uid, gid, mode bits and link target are stored as 823file attributes. For "mapped-file" these attributes are stored in the 824hidden .virtfs_metadata directory. Directories exported by this security model cannot 825interact with other unix tools. "none" security model is same as 826passthrough except the sever won't report failures if it fails to 827set file attributes like ownership. Security model is mandatory only 828for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 829model as a parameter. 830@item writeout=@var{writeout} 831This is an optional argument. The only supported value is "immediate". 832This means that host page cache will be used to read and write data but 833write notification will be sent to the guest only when the data has been 834reported as written by the storage subsystem. 835@item readonly 836Enables exporting 9p share as a readonly mount for guests. By default 837read-write access is given. 838@item socket=@var{socket} 839Enables proxy filesystem driver to use passed socket file for 840communicating with virtfs-proxy-helper. Usually a helper like libvirt 841will create socketpair and pass one of the fds as sock_fd 842@item sock_fd 843Enables proxy filesystem driver to use passed 'sock_fd' as the socket 844descriptor for interfacing with virtfs-proxy-helper 845@end table 846ETEXI 847 848DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 849 "-virtfs_synth Create synthetic file system image\n", 850 QEMU_ARCH_ALL) 851STEXI 852@item -virtfs_synth 853@findex -virtfs_synth 854Create synthetic file system image 855ETEXI 856 857STEXI 858@end table 859ETEXI 860DEFHEADING() 861 862DEFHEADING(USB options:) 863STEXI 864@table @option 865ETEXI 866 867DEF("usb", 0, QEMU_OPTION_usb, 868 "-usb enable the USB driver (will be the default soon)\n", 869 QEMU_ARCH_ALL) 870STEXI 871@item -usb 872@findex -usb 873Enable the USB driver (will be the default soon) 874ETEXI 875 876DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 877 "-usbdevice name add the host or guest USB device 'name'\n", 878 QEMU_ARCH_ALL) 879STEXI 880 881@item -usbdevice @var{devname} 882@findex -usbdevice 883Add the USB device @var{devname}. @xref{usb_devices}. 884 885@table @option 886 887@item mouse 888Virtual Mouse. This will override the PS/2 mouse emulation when activated. 889 890@item tablet 891Pointer device that uses absolute coordinates (like a touchscreen). This 892means QEMU is able to report the mouse position without having to grab the 893mouse. Also overrides the PS/2 mouse emulation when activated. 894 895@item disk:[format=@var{format}]:@var{file} 896Mass storage device based on file. The optional @var{format} argument 897will be used rather than detecting the format. Can be used to specifiy 898@code{format=raw} to avoid interpreting an untrusted format header. 899 900@item host:@var{bus}.@var{addr} 901Pass through the host device identified by @var{bus}.@var{addr} (Linux only). 902 903@item host:@var{vendor_id}:@var{product_id} 904Pass through the host device identified by @var{vendor_id}:@var{product_id} 905(Linux only). 906 907@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev} 908Serial converter to host character device @var{dev}, see @code{-serial} for the 909available devices. 910 911@item braille 912Braille device. This will use BrlAPI to display the braille output on a real 913or fake device. 914 915@item net:@var{options} 916Network adapter that supports CDC ethernet and RNDIS protocols. 917 918@end table 919ETEXI 920 921STEXI 922@end table 923ETEXI 924DEFHEADING() 925 926DEFHEADING(Display options:) 927STEXI 928@table @option 929ETEXI 930 931DEF("display", HAS_ARG, QEMU_OPTION_display, 932 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 933 " [,window_close=on|off]|curses|none|\n" 934 " gtk[,grab_on_hover=on|off]|\n" 935 " vnc=<display>[,<optargs>]\n" 936 " select display type\n", QEMU_ARCH_ALL) 937STEXI 938@item -display @var{type} 939@findex -display 940Select type of display to use. This option is a replacement for the 941old style -sdl/-curses/... options. Valid values for @var{type} are 942@table @option 943@item sdl 944Display video output via SDL (usually in a separate graphics 945window; see the SDL documentation for other possibilities). 946@item curses 947Display video output via curses. For graphics device models which 948support a text mode, QEMU can display this output using a 949curses/ncurses interface. Nothing is displayed when the graphics 950device is in graphical mode or if the graphics device does not support 951a text mode. Generally only the VGA device models support text mode. 952@item none 953Do not display video output. The guest will still see an emulated 954graphics card, but its output will not be displayed to the QEMU 955user. This option differs from the -nographic option in that it 956only affects what is done with video output; -nographic also changes 957the destination of the serial and parallel port data. 958@item gtk 959Display video output in a GTK window. This interface provides drop-down 960menus and other UI elements to configure and control the VM during 961runtime. 962@item vnc 963Start a VNC server on display <arg> 964@end table 965ETEXI 966 967DEF("nographic", 0, QEMU_OPTION_nographic, 968 "-nographic disable graphical output and redirect serial I/Os to console\n", 969 QEMU_ARCH_ALL) 970STEXI 971@item -nographic 972@findex -nographic 973Normally, QEMU uses SDL to display the VGA output. With this option, 974you can totally disable graphical output so that QEMU is a simple 975command line application. The emulated serial port is redirected on 976the console and muxed with the monitor (unless redirected elsewhere 977explicitly). Therefore, you can still use QEMU to debug a Linux kernel 978with a serial console. Use @key{C-a h} for help on switching between 979the console and monitor. 980ETEXI 981 982DEF("curses", 0, QEMU_OPTION_curses, 983 "-curses use a curses/ncurses interface instead of SDL\n", 984 QEMU_ARCH_ALL) 985STEXI 986@item -curses 987@findex -curses 988Normally, QEMU uses SDL to display the VGA output. With this option, 989QEMU can display the VGA output when in text mode using a 990curses/ncurses interface. Nothing is displayed in graphical mode. 991ETEXI 992 993DEF("no-frame", 0, QEMU_OPTION_no_frame, 994 "-no-frame open SDL window without a frame and window decorations\n", 995 QEMU_ARCH_ALL) 996STEXI 997@item -no-frame 998@findex -no-frame 999Do not use decorations for SDL windows and start them using the whole 1000available screen space. This makes the using QEMU in a dedicated desktop 1001workspace more convenient. 1002ETEXI 1003 1004DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1005 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1006 QEMU_ARCH_ALL) 1007STEXI 1008@item -alt-grab 1009@findex -alt-grab 1010Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1011affects the special keys (for fullscreen, monitor-mode switching, etc). 1012ETEXI 1013 1014DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1015 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1016 QEMU_ARCH_ALL) 1017STEXI 1018@item -ctrl-grab 1019@findex -ctrl-grab 1020Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1021affects the special keys (for fullscreen, monitor-mode switching, etc). 1022ETEXI 1023 1024DEF("no-quit", 0, QEMU_OPTION_no_quit, 1025 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1026STEXI 1027@item -no-quit 1028@findex -no-quit 1029Disable SDL window close capability. 1030ETEXI 1031 1032DEF("sdl", 0, QEMU_OPTION_sdl, 1033 "-sdl enable SDL\n", QEMU_ARCH_ALL) 1034STEXI 1035@item -sdl 1036@findex -sdl 1037Enable SDL. 1038ETEXI 1039 1040DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1041 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1042 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1043 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1044 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1045 " [,tls-ciphers=<list>]\n" 1046 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1047 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1048 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1049 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1050 " [,jpeg-wan-compression=[auto|never|always]]\n" 1051 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1052 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1053 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1054 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1055 " [,gl=[on|off]]\n" 1056 " enable spice\n" 1057 " at least one of {port, tls-port} is mandatory\n", 1058 QEMU_ARCH_ALL) 1059STEXI 1060@item -spice @var{option}[,@var{option}[,...]] 1061@findex -spice 1062Enable the spice remote desktop protocol. Valid options are 1063 1064@table @option 1065 1066@item port=<nr> 1067Set the TCP port spice is listening on for plaintext channels. 1068 1069@item addr=<addr> 1070Set the IP address spice is listening on. Default is any address. 1071 1072@item ipv4 1073@itemx ipv6 1074@itemx unix 1075Force using the specified IP version. 1076 1077@item password=<secret> 1078Set the password you need to authenticate. 1079 1080@item sasl 1081Require that the client use SASL to authenticate with the spice. 1082The exact choice of authentication method used is controlled from the 1083system / user's SASL configuration file for the 'qemu' service. This 1084is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1085unprivileged user, an environment variable SASL_CONF_PATH can be used 1086to make it search alternate locations for the service config. 1087While some SASL auth methods can also provide data encryption (eg GSSAPI), 1088it is recommended that SASL always be combined with the 'tls' and 1089'x509' settings to enable use of SSL and server certificates. This 1090ensures a data encryption preventing compromise of authentication 1091credentials. 1092 1093@item disable-ticketing 1094Allow client connects without authentication. 1095 1096@item disable-copy-paste 1097Disable copy paste between the client and the guest. 1098 1099@item disable-agent-file-xfer 1100Disable spice-vdagent based file-xfer between the client and the guest. 1101 1102@item tls-port=<nr> 1103Set the TCP port spice is listening on for encrypted channels. 1104 1105@item x509-dir=<dir> 1106Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1107 1108@item x509-key-file=<file> 1109@itemx x509-key-password=<file> 1110@itemx x509-cert-file=<file> 1111@itemx x509-cacert-file=<file> 1112@itemx x509-dh-key-file=<file> 1113The x509 file names can also be configured individually. 1114 1115@item tls-ciphers=<list> 1116Specify which ciphers to use. 1117 1118@item tls-channel=[main|display|cursor|inputs|record|playback] 1119@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1120Force specific channel to be used with or without TLS encryption. The 1121options can be specified multiple times to configure multiple 1122channels. The special name "default" can be used to set the default 1123mode. For channels which are not explicitly forced into one mode the 1124spice client is allowed to pick tls/plaintext as he pleases. 1125 1126@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1127Configure image compression (lossless). 1128Default is auto_glz. 1129 1130@item jpeg-wan-compression=[auto|never|always] 1131@itemx zlib-glz-wan-compression=[auto|never|always] 1132Configure wan image compression (lossy for slow links). 1133Default is auto. 1134 1135@item streaming-video=[off|all|filter] 1136Configure video stream detection. Default is filter. 1137 1138@item agent-mouse=[on|off] 1139Enable/disable passing mouse events via vdagent. Default is on. 1140 1141@item playback-compression=[on|off] 1142Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1143 1144@item seamless-migration=[on|off] 1145Enable/disable spice seamless migration. Default is off. 1146 1147@item gl=[on|off] 1148Enable/disable OpenGL context. Default is off. 1149 1150@end table 1151ETEXI 1152 1153DEF("portrait", 0, QEMU_OPTION_portrait, 1154 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1155 QEMU_ARCH_ALL) 1156STEXI 1157@item -portrait 1158@findex -portrait 1159Rotate graphical output 90 deg left (only PXA LCD). 1160ETEXI 1161 1162DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1163 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1164 QEMU_ARCH_ALL) 1165STEXI 1166@item -rotate @var{deg} 1167@findex -rotate 1168Rotate graphical output some deg left (only PXA LCD). 1169ETEXI 1170 1171DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1172 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1173 " select video card type\n", QEMU_ARCH_ALL) 1174STEXI 1175@item -vga @var{type} 1176@findex -vga 1177Select type of VGA card to emulate. Valid values for @var{type} are 1178@table @option 1179@item cirrus 1180Cirrus Logic GD5446 Video card. All Windows versions starting from 1181Windows 95 should recognize and use this graphic card. For optimal 1182performances, use 16 bit color depth in the guest and the host OS. 1183(This one is the default) 1184@item std 1185Standard VGA card with Bochs VBE extensions. If your guest OS 1186supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1187to use high resolution modes (>= 1280x1024x16) then you should use 1188this option. 1189@item vmware 1190VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1191recent XFree86/XOrg server or Windows guest with a driver for this 1192card. 1193@item qxl 1194QXL paravirtual graphic card. It is VGA compatible (including VESA 11952.0 VBE support). Works best with qxl guest drivers installed though. 1196Recommended choice when using the spice protocol. 1197@item tcx 1198(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1199sun4m machines and offers both 8-bit and 24-bit colour depths at a 1200fixed resolution of 1024x768. 1201@item cg3 1202(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1203for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1204resolutions aimed at people wishing to run older Solaris versions. 1205@item virtio 1206Virtio VGA card. 1207@item none 1208Disable VGA card. 1209@end table 1210ETEXI 1211 1212DEF("full-screen", 0, QEMU_OPTION_full_screen, 1213 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1214STEXI 1215@item -full-screen 1216@findex -full-screen 1217Start in full screen. 1218ETEXI 1219 1220DEF("g", 1, QEMU_OPTION_g , 1221 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1222 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1223STEXI 1224@item -g @var{width}x@var{height}[x@var{depth}] 1225@findex -g 1226Set the initial graphical resolution and depth (PPC, SPARC only). 1227ETEXI 1228 1229DEF("input-linux", 1, QEMU_OPTION_input_linux, 1230 "-input-linux <evdev>\n" 1231 " Use input device.\n", QEMU_ARCH_ALL) 1232STEXI 1233@item -input-linux @var{dev} 1234@findex -input-linux 1235Use input device. 1236ETEXI 1237 1238DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1239 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL) 1240STEXI 1241@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1242@findex -vnc 1243Normally, QEMU uses SDL to display the VGA output. With this option, 1244you can have QEMU listen on VNC display @var{display} and redirect the VGA 1245display over the VNC session. It is very useful to enable the usb 1246tablet device when using this option (option @option{-usbdevice 1247tablet}). When using the VNC display, you must use the @option{-k} 1248parameter to set the keyboard layout if you are not using en-us. Valid 1249syntax for the @var{display} is 1250 1251@table @option 1252 1253@item @var{host}:@var{d} 1254 1255TCP connections will only be allowed from @var{host} on display @var{d}. 1256By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1257be omitted in which case the server will accept connections from any host. 1258 1259@item unix:@var{path} 1260 1261Connections will be allowed over UNIX domain sockets where @var{path} is the 1262location of a unix socket to listen for connections on. 1263 1264@item none 1265 1266VNC is initialized but not started. The monitor @code{change} command 1267can be used to later start the VNC server. 1268 1269@end table 1270 1271Following the @var{display} value there may be one or more @var{option} flags 1272separated by commas. Valid options are 1273 1274@table @option 1275 1276@item reverse 1277 1278Connect to a listening VNC client via a ``reverse'' connection. The 1279client is specified by the @var{display}. For reverse network 1280connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1281is a TCP port number, not a display number. 1282 1283@item websocket 1284 1285Opens an additional TCP listening port dedicated to VNC Websocket connections. 1286By definition the Websocket port is 5700+@var{display}. If @var{host} is 1287specified connections will only be allowed from this host. 1288As an alternative the Websocket port could be specified by using 1289@code{websocket}=@var{port}. 1290If no TLS credentials are provided, the websocket connection runs in 1291unencrypted mode. If TLS credentials are provided, the websocket connection 1292requires encrypted client connections. 1293 1294@item password 1295 1296Require that password based authentication is used for client connections. 1297 1298The password must be set separately using the @code{set_password} command in 1299the @ref{pcsys_monitor}. The syntax to change your password is: 1300@code{set_password <protocol> <password>} where <protocol> could be either 1301"vnc" or "spice". 1302 1303If you would like to change <protocol> password expiration, you should use 1304@code{expire_password <protocol> <expiration-time>} where expiration time could 1305be one of the following options: now, never, +seconds or UNIX time of 1306expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1307to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1308date and time). 1309 1310You can also use keywords "now" or "never" for the expiration time to 1311allow <protocol> password to expire immediately or never expire. 1312 1313@item tls-creds=@var{ID} 1314 1315Provides the ID of a set of TLS credentials to use to secure the 1316VNC server. They will apply to both the normal VNC server socket 1317and the websocket socket (if enabled). Setting TLS credentials 1318will cause the VNC server socket to enable the VeNCrypt auth 1319mechanism. The credentials should have been previously created 1320using the @option{-object tls-creds} argument. 1321 1322The @option{tls-creds} parameter obsoletes the @option{tls}, 1323@option{x509}, and @option{x509verify} options, and as such 1324it is not permitted to set both new and old type options at 1325the same time. 1326 1327@item tls 1328 1329Require that client use TLS when communicating with the VNC server. This 1330uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1331attack. It is recommended that this option be combined with either the 1332@option{x509} or @option{x509verify} options. 1333 1334This option is now deprecated in favor of using the @option{tls-creds} 1335argument. 1336 1337@item x509=@var{/path/to/certificate/dir} 1338 1339Valid if @option{tls} is specified. Require that x509 credentials are used 1340for negotiating the TLS session. The server will send its x509 certificate 1341to the client. It is recommended that a password be set on the VNC server 1342to provide authentication of the client when this is used. The path following 1343this option specifies where the x509 certificates are to be loaded from. 1344See the @ref{vnc_security} section for details on generating certificates. 1345 1346This option is now deprecated in favour of using the @option{tls-creds} 1347argument. 1348 1349@item x509verify=@var{/path/to/certificate/dir} 1350 1351Valid if @option{tls} is specified. Require that x509 credentials are used 1352for negotiating the TLS session. The server will send its x509 certificate 1353to the client, and request that the client send its own x509 certificate. 1354The server will validate the client's certificate against the CA certificate, 1355and reject clients when validation fails. If the certificate authority is 1356trusted, this is a sufficient authentication mechanism. You may still wish 1357to set a password on the VNC server as a second authentication layer. The 1358path following this option specifies where the x509 certificates are to 1359be loaded from. See the @ref{vnc_security} section for details on generating 1360certificates. 1361 1362This option is now deprecated in favour of using the @option{tls-creds} 1363argument. 1364 1365@item sasl 1366 1367Require that the client use SASL to authenticate with the VNC server. 1368The exact choice of authentication method used is controlled from the 1369system / user's SASL configuration file for the 'qemu' service. This 1370is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1371unprivileged user, an environment variable SASL_CONF_PATH can be used 1372to make it search alternate locations for the service config. 1373While some SASL auth methods can also provide data encryption (eg GSSAPI), 1374it is recommended that SASL always be combined with the 'tls' and 1375'x509' settings to enable use of SSL and server certificates. This 1376ensures a data encryption preventing compromise of authentication 1377credentials. See the @ref{vnc_security} section for details on using 1378SASL authentication. 1379 1380@item acl 1381 1382Turn on access control lists for checking of the x509 client certificate 1383and SASL party. For x509 certs, the ACL check is made against the 1384certificate's distinguished name. This is something that looks like 1385@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1386made against the username, which depending on the SASL plugin, may 1387include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1388When the @option{acl} flag is set, the initial access list will be 1389empty, with a @code{deny} policy. Thus no one will be allowed to 1390use the VNC server until the ACLs have been loaded. This can be 1391achieved using the @code{acl} monitor command. 1392 1393@item lossy 1394 1395Enable lossy compression methods (gradient, JPEG, ...). If this 1396option is set, VNC client may receive lossy framebuffer updates 1397depending on its encoding settings. Enabling this option can save 1398a lot of bandwidth at the expense of quality. 1399 1400@item non-adaptive 1401 1402Disable adaptive encodings. Adaptive encodings are enabled by default. 1403An adaptive encoding will try to detect frequently updated screen regions, 1404and send updates in these regions using a lossy encoding (like JPEG). 1405This can be really helpful to save bandwidth when playing videos. Disabling 1406adaptive encodings restores the original static behavior of encodings 1407like Tight. 1408 1409@item share=[allow-exclusive|force-shared|ignore] 1410 1411Set display sharing policy. 'allow-exclusive' allows clients to ask 1412for exclusive access. As suggested by the rfb spec this is 1413implemented by dropping other connections. Connecting multiple 1414clients in parallel requires all clients asking for a shared session 1415(vncviewer: -shared switch). This is the default. 'force-shared' 1416disables exclusive client access. Useful for shared desktop sessions, 1417where you don't want someone forgetting specify -shared disconnect 1418everybody else. 'ignore' completely ignores the shared flag and 1419allows everybody connect unconditionally. Doesn't conform to the rfb 1420spec but is traditional QEMU behavior. 1421 1422@end table 1423ETEXI 1424 1425STEXI 1426@end table 1427ETEXI 1428ARCHHEADING(, QEMU_ARCH_I386) 1429 1430ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1431STEXI 1432@table @option 1433ETEXI 1434 1435DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1436 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1437 QEMU_ARCH_I386) 1438STEXI 1439@item -win2k-hack 1440@findex -win2k-hack 1441Use it when installing Windows 2000 to avoid a disk full bug. After 1442Windows 2000 is installed, you no longer need this option (this option 1443slows down the IDE transfers). 1444ETEXI 1445 1446HXCOMM Deprecated by -rtc 1447DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1448 1449DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1450 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1451 QEMU_ARCH_I386) 1452STEXI 1453@item -no-fd-bootchk 1454@findex -no-fd-bootchk 1455Disable boot signature checking for floppy disks in BIOS. May 1456be needed to boot from old floppy disks. 1457ETEXI 1458 1459DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1460 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1461STEXI 1462@item -no-acpi 1463@findex -no-acpi 1464Disable ACPI (Advanced Configuration and Power Interface) support. Use 1465it if your guest OS complains about ACPI problems (PC target machine 1466only). 1467ETEXI 1468 1469DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1470 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1471STEXI 1472@item -no-hpet 1473@findex -no-hpet 1474Disable HPET support. 1475ETEXI 1476 1477DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1478 "-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" 1479 " ACPI table description\n", QEMU_ARCH_I386) 1480STEXI 1481@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}]...] 1482@findex -acpitable 1483Add ACPI table with specified header fields and context from specified files. 1484For file=, take whole ACPI table from the specified files, including all 1485ACPI headers (possible overridden by other options). 1486For data=, only data 1487portion of the table is used, all header information is specified in the 1488command line. 1489If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 1490fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 1491to ensure the field matches required by the Microsoft SLIC spec and the ACPI 1492spec. 1493ETEXI 1494 1495DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1496 "-smbios file=binary\n" 1497 " load SMBIOS entry from binary file\n" 1498 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1499 " [,uefi=on|off]\n" 1500 " specify SMBIOS type 0 fields\n" 1501 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1502 " [,uuid=uuid][,sku=str][,family=str]\n" 1503 " specify SMBIOS type 1 fields\n" 1504 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1505 " [,asset=str][,location=str]\n" 1506 " specify SMBIOS type 2 fields\n" 1507 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1508 " [,sku=str]\n" 1509 " specify SMBIOS type 3 fields\n" 1510 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1511 " [,asset=str][,part=str]\n" 1512 " specify SMBIOS type 4 fields\n" 1513 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1514 " [,asset=str][,part=str][,speed=%d]\n" 1515 " specify SMBIOS type 17 fields\n", 1516 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1517STEXI 1518@item -smbios file=@var{binary} 1519@findex -smbios 1520Load SMBIOS entry from binary file. 1521 1522@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1523Specify SMBIOS type 0 fields 1524 1525@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}] 1526Specify SMBIOS type 1 fields 1527 1528@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}] 1529Specify SMBIOS type 2 fields 1530 1531@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1532Specify SMBIOS type 3 fields 1533 1534@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1535Specify SMBIOS type 4 fields 1536 1537@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}] 1538Specify SMBIOS type 17 fields 1539ETEXI 1540 1541STEXI 1542@end table 1543ETEXI 1544DEFHEADING() 1545 1546DEFHEADING(Network options:) 1547STEXI 1548@table @option 1549ETEXI 1550 1551HXCOMM Legacy slirp options (now moved to -net user): 1552#ifdef CONFIG_SLIRP 1553DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1554DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1555DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1556#ifndef _WIN32 1557DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1558#endif 1559#endif 1560 1561DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1562#ifdef CONFIG_SLIRP 1563 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n" 1564 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n" 1565 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1566#ifndef _WIN32 1567 "[,smb=dir[,smbserver=addr]]\n" 1568#endif 1569 " configure a user mode network backend with ID 'str',\n" 1570 " its DHCP server and optional services\n" 1571#endif 1572#ifdef _WIN32 1573 "-netdev tap,id=str,ifname=name\n" 1574 " configure a host TAP network backend with ID 'str'\n" 1575#else 1576 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1577 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1578 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1579 " configure a host TAP network backend with ID 'str'\n" 1580 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1581 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1582 " to deconfigure it\n" 1583 " use '[down]script=no' to disable script execution\n" 1584 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1585 " configure it\n" 1586 " use 'fd=h' to connect to an already opened TAP interface\n" 1587 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1588 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1589 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1590 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1591 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1592 " use vhost=on to enable experimental in kernel accelerator\n" 1593 " (only has effect for virtio guests which use MSIX)\n" 1594 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1595 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1596 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1597 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1598 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1599 " configure a host TAP network backend with ID 'str' that is\n" 1600 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1601 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1602#endif 1603#ifdef __linux__ 1604 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1605 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1606 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1607 " [,rxcookie=rxcookie][,offset=offset]\n" 1608 " configure a network backend with ID 'str' connected to\n" 1609 " an Ethernet over L2TPv3 pseudowire.\n" 1610 " Linux kernel 3.3+ as well as most routers can talk\n" 1611 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1612 " VM to a router and even VM to Host. It is a nearly-universal\n" 1613 " standard (RFC3391). Note - this implementation uses static\n" 1614 " pre-configured tunnels (same as the Linux kernel).\n" 1615 " use 'src=' to specify source address\n" 1616 " use 'dst=' to specify destination address\n" 1617 " use 'udp=on' to specify udp encapsulation\n" 1618 " use 'srcport=' to specify source udp port\n" 1619 " use 'dstport=' to specify destination udp port\n" 1620 " use 'ipv6=on' to force v6\n" 1621 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1622 " well as a weak security measure\n" 1623 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1624 " use 'txcookie=0x012345678' to specify a txcookie\n" 1625 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1626 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1627 " use 'pincounter=on' to work around broken counter handling in peer\n" 1628 " use 'offset=X' to add an extra offset between header and data\n" 1629#endif 1630 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1631 " configure a network backend to connect to another network\n" 1632 " using a socket connection\n" 1633 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1634 " configure a network backend to connect to a multicast maddr and port\n" 1635 " use 'localaddr=addr' to specify the host address to send packets from\n" 1636 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1637 " configure a network backend to connect to another network\n" 1638 " using an UDP tunnel\n" 1639#ifdef CONFIG_VDE 1640 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1641 " configure a network backend to connect to port 'n' of a vde switch\n" 1642 " running on host and listening for incoming connections on 'socketpath'.\n" 1643 " Use group 'groupname' and mode 'octalmode' to change default\n" 1644 " ownership and permissions for communication port.\n" 1645#endif 1646#ifdef CONFIG_NETMAP 1647 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 1648 " attach to the existing netmap-enabled network interface 'name', or to a\n" 1649 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 1650 " netmap device, defaults to '/dev/netmap')\n" 1651#endif 1652 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 1653 " configure a vhost-user network, backed by a chardev 'dev'\n" 1654 "-netdev hubport,id=str,hubid=n\n" 1655 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL) 1656DEF("net", HAS_ARG, QEMU_OPTION_net, 1657 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 1658 " old way to create a new NIC and connect it to VLAN 'n'\n" 1659 " (use the '-device devtype,netdev=str' option if possible instead)\n" 1660 "-net dump[,vlan=n][,file=f][,len=n]\n" 1661 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n" 1662 "-net none use it alone to have zero network devices. If no -net option\n" 1663 " is provided, the default is '-net nic -net user'\n" 1664 "-net [" 1665#ifdef CONFIG_SLIRP 1666 "user|" 1667#endif 1668 "tap|" 1669 "bridge|" 1670#ifdef CONFIG_VDE 1671 "vde|" 1672#endif 1673#ifdef CONFIG_NETMAP 1674 "netmap|" 1675#endif 1676 "socket][,vlan=n][,option][,option][,...]\n" 1677 " old way to initialize a host network interface\n" 1678 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 1679STEXI 1680@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 1681@findex -net 1682Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n} 1683= 0 is the default). The NIC is an e1000 by default on the PC 1684target. Optionally, the MAC address can be changed to @var{mac}, the 1685device address set to @var{addr} (PCI cards only), 1686and a @var{name} can be assigned for use in monitor commands. 1687Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 1688that the card should have; this option currently only affects virtio cards; set 1689@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 1690NIC is created. QEMU can emulate several different models of network card. 1691Valid values for @var{type} are 1692@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er}, 1693@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139}, 1694@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}. 1695Not all devices are supported on all targets. Use @code{-net nic,model=help} 1696for a list of available devices for your target. 1697 1698@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 1699@findex -netdev 1700@item -net user[,@var{option}][,@var{option}][,...] 1701Use the user mode network stack which requires no administrator 1702privilege to run. Valid options are: 1703 1704@table @option 1705@item vlan=@var{n} 1706Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default). 1707 1708@item id=@var{id} 1709@itemx name=@var{name} 1710Assign symbolic name for use in monitor commands. 1711 1712@item net=@var{addr}[/@var{mask}] 1713Set IP network address the guest will see. Optionally specify the netmask, 1714either in the form a.b.c.d or as number of valid top-most bits. Default is 171510.0.2.0/24. 1716 1717@item host=@var{addr} 1718Specify the guest-visible address of the host. Default is the 2nd IP in the 1719guest network, i.e. x.x.x.2. 1720 1721@item restrict=on|off 1722If this option is enabled, the guest will be isolated, i.e. it will not be 1723able to contact the host and no guest IP packets will be routed over the host 1724to the outside. This option does not affect any explicitly set forwarding rules. 1725 1726@item hostname=@var{name} 1727Specifies the client hostname reported by the built-in DHCP server. 1728 1729@item dhcpstart=@var{addr} 1730Specify the first of the 16 IPs the built-in DHCP server can assign. Default 1731is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 1732 1733@item dns=@var{addr} 1734Specify the guest-visible address of the virtual nameserver. The address must 1735be different from the host address. Default is the 3rd IP in the guest network, 1736i.e. x.x.x.3. 1737 1738@item dnssearch=@var{domain} 1739Provides an entry for the domain-search list sent by the built-in 1740DHCP server. More than one domain suffix can be transmitted by specifying 1741this option multiple times. If supported, this will cause the guest to 1742automatically try to append the given domain suffix(es) in case a domain name 1743can not be resolved. 1744 1745Example: 1746@example 1747qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...] 1748@end example 1749 1750@item tftp=@var{dir} 1751When using the user mode network stack, activate a built-in TFTP 1752server. The files in @var{dir} will be exposed as the root of a TFTP server. 1753The TFTP client on the guest must be configured in binary mode (use the command 1754@code{bin} of the Unix TFTP client). 1755 1756@item bootfile=@var{file} 1757When using the user mode network stack, broadcast @var{file} as the BOOTP 1758filename. In conjunction with @option{tftp}, this can be used to network boot 1759a guest from a local directory. 1760 1761Example (using pxelinux): 1762@example 1763qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 1764@end example 1765 1766@item smb=@var{dir}[,smbserver=@var{addr}] 1767When using the user mode network stack, activate a built-in SMB 1768server so that Windows OSes can access to the host files in @file{@var{dir}} 1769transparently. The IP address of the SMB server can be set to @var{addr}. By 1770default the 4th IP in the guest network is used, i.e. x.x.x.4. 1771 1772In the guest Windows OS, the line: 1773@example 177410.0.2.4 smbserver 1775@end example 1776must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 1777or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 1778 1779Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 1780 1781Note that a SAMBA server must be installed on the host OS. 1782QEMU was tested successfully with smbd versions from Red Hat 9, 1783Fedora Core 3 and OpenSUSE 11.x. 1784 1785@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 1786Redirect incoming TCP or UDP connections to the host port @var{hostport} to 1787the guest IP address @var{guestaddr} on guest port @var{guestport}. If 1788@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 1789given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 1790be bound to a specific host interface. If no connection type is set, TCP is 1791used. This option can be given multiple times. 1792 1793For example, to redirect host X11 connection from screen 1 to guest 1794screen 0, use the following: 1795 1796@example 1797# on the host 1798qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...] 1799# this host xterm should open in the guest X11 server 1800xterm -display :1 1801@end example 1802 1803To redirect telnet connections from host port 5555 to telnet port on 1804the guest, use the following: 1805 1806@example 1807# on the host 1808qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...] 1809telnet localhost 5555 1810@end example 1811 1812Then when you use on the host @code{telnet localhost 5555}, you 1813connect to the guest telnet server. 1814 1815@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 1816@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 1817Forward guest TCP connections to the IP address @var{server} on port @var{port} 1818to the character device @var{dev} or to a program executed by @var{cmd:command} 1819which gets spawned for each connection. This option can be given multiple times. 1820 1821You can either use a chardev directly and have that one used throughout QEMU's 1822lifetime, like in the following example: 1823 1824@example 1825# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 1826# the guest accesses it 1827qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...] 1828@end example 1829 1830Or you can execute a command on every TCP connection established by the guest, 1831so that QEMU behaves similar to an inetd process for that virtual server: 1832 1833@example 1834# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 1835# and connect the TCP stream to its stdin/stdout 1836qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 1837@end example 1838 1839@end table 1840 1841Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 1842processed and applied to -net user. Mixing them with the new configuration 1843syntax gives undefined results. Their use for new applications is discouraged 1844as they will be removed from future versions. 1845 1846@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1847@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1848Connect the host TAP network interface @var{name} to VLAN @var{n}. 1849 1850Use the network script @var{file} to configure it and the network script 1851@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 1852automatically provides one. The default network configure script is 1853@file{/etc/qemu-ifup} and the default network deconfigure script is 1854@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 1855to disable script execution. 1856 1857If running QEMU as an unprivileged user, use the network helper 1858@var{helper} to configure the TAP interface. The default network 1859helper executable is @file{/path/to/qemu-bridge-helper}. 1860 1861@option{fd}=@var{h} can be used to specify the handle of an already 1862opened host TAP interface. 1863 1864Examples: 1865 1866@example 1867#launch a QEMU instance with the default network script 1868qemu-system-i386 linux.img -net nic -net tap 1869@end example 1870 1871@example 1872#launch a QEMU instance with two NICs, each one connected 1873#to a TAP device 1874qemu-system-i386 linux.img \ 1875 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ 1876 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 1877@end example 1878 1879@example 1880#launch a QEMU instance with the default network helper to 1881#connect a TAP device to bridge br0 1882qemu-system-i386 linux.img \ 1883 -net nic -net tap,"helper=/path/to/qemu-bridge-helper" 1884@end example 1885 1886@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 1887@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}] 1888Connect a host TAP network interface to a host bridge device. 1889 1890Use the network helper @var{helper} to configure the TAP interface and 1891attach it to the bridge. The default network helper executable is 1892@file{/path/to/qemu-bridge-helper} and the default bridge 1893device is @file{br0}. 1894 1895Examples: 1896 1897@example 1898#launch a QEMU instance with the default network helper to 1899#connect a TAP device to bridge br0 1900qemu-system-i386 linux.img -net bridge -net nic,model=virtio 1901@end example 1902 1903@example 1904#launch a QEMU instance with the default network helper to 1905#connect a TAP device to bridge qemubr0 1906qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio 1907@end example 1908 1909@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1910@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1911 1912Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual 1913machine using a TCP socket connection. If @option{listen} is 1914specified, QEMU waits for incoming connections on @var{port} 1915(@var{host} is optional). @option{connect} is used to connect to 1916another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 1917specifies an already opened TCP socket. 1918 1919Example: 1920@example 1921# launch a first QEMU instance 1922qemu-system-i386 linux.img \ 1923 -net nic,macaddr=52:54:00:12:34:56 \ 1924 -net socket,listen=:1234 1925# connect the VLAN 0 of this instance to the VLAN 0 1926# of the first instance 1927qemu-system-i386 linux.img \ 1928 -net nic,macaddr=52:54:00:12:34:57 \ 1929 -net socket,connect=127.0.0.1:1234 1930@end example 1931 1932@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1933@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1934 1935Create a VLAN @var{n} shared with another QEMU virtual 1936machines using a UDP multicast socket, effectively making a bus for 1937every QEMU with same multicast address @var{maddr} and @var{port}. 1938NOTES: 1939@enumerate 1940@item 1941Several QEMU can be running on different hosts and share same bus (assuming 1942correct multicast setup for these hosts). 1943@item 1944mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 1945@url{http://user-mode-linux.sf.net}. 1946@item 1947Use @option{fd=h} to specify an already opened UDP multicast socket. 1948@end enumerate 1949 1950Example: 1951@example 1952# launch one QEMU instance 1953qemu-system-i386 linux.img \ 1954 -net nic,macaddr=52:54:00:12:34:56 \ 1955 -net socket,mcast=230.0.0.1:1234 1956# launch another QEMU instance on same "bus" 1957qemu-system-i386 linux.img \ 1958 -net nic,macaddr=52:54:00:12:34:57 \ 1959 -net socket,mcast=230.0.0.1:1234 1960# launch yet another QEMU instance on same "bus" 1961qemu-system-i386 linux.img \ 1962 -net nic,macaddr=52:54:00:12:34:58 \ 1963 -net socket,mcast=230.0.0.1:1234 1964@end example 1965 1966Example (User Mode Linux compat.): 1967@example 1968# launch QEMU instance (note mcast address selected 1969# is UML's default) 1970qemu-system-i386 linux.img \ 1971 -net nic,macaddr=52:54:00:12:34:56 \ 1972 -net socket,mcast=239.192.168.1:1102 1973# launch UML 1974/path/to/linux ubd0=/path/to/root_fs eth0=mcast 1975@end example 1976 1977Example (send packets from host's 1.2.3.4): 1978@example 1979qemu-system-i386 linux.img \ 1980 -net nic,macaddr=52:54:00:12:34:56 \ 1981 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 1982@end example 1983 1984@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}] 1985@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}] 1986Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular 1987protocol to transport Ethernet (and other Layer 2) data frames between 1988two systems. It is present in routers, firewalls and the Linux kernel 1989(from version 3.3 onwards). 1990 1991This transport allows a VM to communicate to another VM, router or firewall directly. 1992 1993@item src=@var{srcaddr} 1994 source address (mandatory) 1995@item dst=@var{dstaddr} 1996 destination address (mandatory) 1997@item udp 1998 select udp encapsulation (default is ip). 1999@item srcport=@var{srcport} 2000 source udp port. 2001@item dstport=@var{dstport} 2002 destination udp port. 2003@item ipv6 2004 force v6, otherwise defaults to v4. 2005@item rxcookie=@var{rxcookie} 2006@itemx txcookie=@var{txcookie} 2007 Cookies are a weak form of security in the l2tpv3 specification. 2008Their function is mostly to prevent misconfiguration. By default they are 32 2009bit. 2010@item cookie64 2011 Set cookie size to 64 bit instead of the default 32 2012@item counter=off 2013 Force a 'cut-down' L2TPv3 with no counter as in 2014draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2015@item pincounter=on 2016 Work around broken counter handling in peer. This may also help on 2017networks which have packet reorder. 2018@item offset=@var{offset} 2019 Add an extra offset between header and data 2020 2021For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2022on the remote Linux host 1.2.3.4: 2023@example 2024# Setup tunnel on linux host using raw ip as encapsulation 2025# on 1.2.3.4 2026ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2027 encap udp udp_sport 16384 udp_dport 16384 2028ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2029 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2030ifconfig vmtunnel0 mtu 1500 2031ifconfig vmtunnel0 up 2032brctl addif br-lan vmtunnel0 2033 2034 2035# on 4.3.2.1 2036# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2037 2038qemu-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 2039 2040 2041@end example 2042 2043@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2044@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2045Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and 2046listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2047and MODE @var{octalmode} to change default ownership and permissions for 2048communication port. This option is only available if QEMU has been compiled 2049with vde support enabled. 2050 2051Example: 2052@example 2053# launch vde switch 2054vde_switch -F -sock /tmp/myswitch 2055# launch QEMU instance 2056qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch 2057@end example 2058 2059@item -netdev hubport,id=@var{id},hubid=@var{hubid} 2060 2061Create a hub port on QEMU "vlan" @var{hubid}. 2062 2063The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single 2064netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the 2065required hub automatically. 2066 2067@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2068 2069Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2070be a unix domain socket backed one. The vhost-user uses a specifically defined 2071protocol to pass vhost ioctl replacement messages to an application on the other 2072end of the socket. On non-MSIX guests, the feature can be forced with 2073@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2074be created for multiqueue vhost-user. 2075 2076Example: 2077@example 2078qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2079 -numa node,memdev=mem \ 2080 -chardev socket,path=/path/to/socket \ 2081 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2082 -device virtio-net-pci,netdev=net0 2083@end example 2084 2085@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}] 2086Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default). 2087At most @var{len} bytes (64k by default) per packet are stored. The file format is 2088libpcap, so it can be analyzed with tools such as tcpdump or Wireshark. 2089Note: For devices created with '-netdev', use '-object filter-dump,...' instead. 2090 2091@item -net none 2092Indicate that no network devices should be configured. It is used to 2093override the default configuration (@option{-net nic -net user}) which 2094is activated if no @option{-net} options are provided. 2095ETEXI 2096 2097STEXI 2098@end table 2099ETEXI 2100DEFHEADING() 2101 2102DEFHEADING(Character device options:) 2103STEXI 2104 2105The general form of a character device option is: 2106@table @option 2107ETEXI 2108 2109DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2110 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2111 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2112 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n" 2113 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n" 2114 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n" 2115 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2116 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2117 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2118 " [,logfile=PATH][,logappend=on|off]\n" 2119 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2120 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2121 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2122 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2123 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2124 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2125#ifdef _WIN32 2126 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2127 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2128#else 2129 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2130 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2131#endif 2132#ifdef CONFIG_BRLAPI 2133 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2134#endif 2135#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2136 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2137 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2138 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2139#endif 2140#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2141 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2142 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2143#endif 2144#if defined(CONFIG_SPICE) 2145 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2146 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2147#endif 2148 , QEMU_ARCH_ALL 2149) 2150 2151STEXI 2152@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}] 2153@findex -chardev 2154Backend is one of: 2155@option{null}, 2156@option{socket}, 2157@option{udp}, 2158@option{msmouse}, 2159@option{vc}, 2160@option{ringbuf}, 2161@option{file}, 2162@option{pipe}, 2163@option{console}, 2164@option{serial}, 2165@option{pty}, 2166@option{stdio}, 2167@option{braille}, 2168@option{tty}, 2169@option{parallel}, 2170@option{parport}, 2171@option{spicevmc}. 2172@option{spiceport}. 2173The specific backend will determine the applicable options. 2174 2175All devices must have an id, which can be any string up to 127 characters long. 2176It is used to uniquely identify this device in other command line directives. 2177 2178A character device may be used in multiplexing mode by multiple front-ends. 2179Specify @option{mux=on} to enable this mode. 2180A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2181backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2182If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2183create a multiplexer with your specified ID, and you can then configure multiple 2184front ends to use that chardev ID for their input/output. Up to four different 2185front ends can be connected to a single multiplexed chardev. (Without 2186multiplexing enabled, a chardev can only be used by a single front end.) 2187For instance you could use this to allow a single stdio chardev to be used by 2188two serial ports and the QEMU monitor: 2189 2190@example 2191-chardev stdio,mux=on,id=char0 \ 2192-mon chardev=char0,mode=readline,default \ 2193-serial chardev:char0 \ 2194-serial chardev:char0 2195@end example 2196 2197You can have more than one multiplexer in a system configuration; for instance 2198you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2199multiplexed between the QEMU monitor and a parallel port: 2200 2201@example 2202-chardev stdio,mux=on,id=char0 \ 2203-mon chardev=char0,mode=readline,default \ 2204-parallel chardev:char0 \ 2205-chardev tcp,...,mux=on,id=char1 \ 2206-serial chardev:char1 \ 2207-serial chardev:char1 2208@end example 2209 2210When you're using a multiplexed character device, some escape sequences are 2211interpreted in the input. @xref{mux_keys, Keys in the character backend 2212multiplexer}. 2213 2214Note that some other command line options may implicitly create multiplexed 2215character backends; for instance @option{-serial mon:stdio} creates a 2216multiplexed stdio backend connected to the serial port and the QEMU monitor, 2217and @option{-nographic} also multiplexes the console and the monitor to 2218stdio. 2219 2220There is currently no support for multiplexing in the other direction 2221(where a single QEMU front end takes input and output from multiple chardevs). 2222 2223Every backend supports the @option{logfile} option, which supplies the path 2224to a file to record all data transmitted via the backend. The @option{logappend} 2225option controls whether the log file will be truncated or appended to when 2226opened. 2227 2228Further options to each backend are described below. 2229 2230@item -chardev null ,id=@var{id} 2231A void device. This device will not emit any data, and will drop any data it 2232receives. The null backend does not take any options. 2233 2234@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}] 2235 2236Create a two-way stream socket, which can be either a TCP or a unix socket. A 2237unix socket will be created if @option{path} is specified. Behaviour is 2238undefined if TCP options are specified for a unix socket. 2239 2240@option{server} specifies that the socket shall be a listening socket. 2241 2242@option{nowait} specifies that QEMU should not block waiting for a client to 2243connect to a listening socket. 2244 2245@option{telnet} specifies that traffic on the socket should interpret telnet 2246escape sequences. 2247 2248@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2249the remote end goes away. qemu will delay this many seconds and then attempt 2250to reconnect. Zero disables reconnecting, and is the default. 2251 2252@option{tls-creds} requests enablement of the TLS protocol for encryption, 2253and specifies the id of the TLS credentials to use for the handshake. The 2254credentials must be previously created with the @option{-object tls-creds} 2255argument. 2256 2257TCP and unix socket options are given below: 2258 2259@table @option 2260 2261@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay] 2262 2263@option{host} for a listening socket specifies the local address to be bound. 2264For a connecting socket species the remote host to connect to. @option{host} is 2265optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2266 2267@option{port} for a listening socket specifies the local port to be bound. For a 2268connecting socket specifies the port on the remote host to connect to. 2269@option{port} can be given as either a port number or a service name. 2270@option{port} is required. 2271 2272@option{to} is only relevant to listening sockets. If it is specified, and 2273@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2274to and including @option{to} until it succeeds. @option{to} must be specified 2275as a port number. 2276 2277@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2278If neither is specified the socket may use either protocol. 2279 2280@option{nodelay} disables the Nagle algorithm. 2281 2282@item unix options: path=@var{path} 2283 2284@option{path} specifies the local path of the unix socket. @option{path} is 2285required. 2286 2287@end table 2288 2289@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6] 2290 2291Sends all traffic from the guest to a remote host over UDP. 2292 2293@option{host} specifies the remote host to connect to. If not specified it 2294defaults to @code{localhost}. 2295 2296@option{port} specifies the port on the remote host to connect to. @option{port} 2297is required. 2298 2299@option{localaddr} specifies the local address to bind to. If not specified it 2300defaults to @code{0.0.0.0}. 2301 2302@option{localport} specifies the local port to bind to. If not specified any 2303available local port will be used. 2304 2305@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2306If neither is specified the device may use either protocol. 2307 2308@item -chardev msmouse ,id=@var{id} 2309 2310Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2311take any options. 2312 2313@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]] 2314 2315Connect to a QEMU text console. @option{vc} may optionally be given a specific 2316size. 2317 2318@option{width} and @option{height} specify the width and height respectively of 2319the console, in pixels. 2320 2321@option{cols} and @option{rows} specify that the console be sized to fit a text 2322console with the given dimensions. 2323 2324@item -chardev ringbuf ,id=@var{id} [,size=@var{size}] 2325 2326Create a ring buffer with fixed size @option{size}. 2327@var{size} must be a power of two, and defaults to @code{64K}). 2328 2329@item -chardev file ,id=@var{id} ,path=@var{path} 2330 2331Log all traffic received from the guest to a file. 2332 2333@option{path} specifies the path of the file to be opened. This file will be 2334created if it does not already exist, and overwritten if it does. @option{path} 2335is required. 2336 2337@item -chardev pipe ,id=@var{id} ,path=@var{path} 2338 2339Create a two-way connection to the guest. The behaviour differs slightly between 2340Windows hosts and other hosts: 2341 2342On Windows, a single duplex pipe will be created at 2343@file{\\.pipe\@option{path}}. 2344 2345On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2346@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2347received by the guest. Data written by the guest can be read from 2348@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2349be present. 2350 2351@option{path} forms part of the pipe path as described above. @option{path} is 2352required. 2353 2354@item -chardev console ,id=@var{id} 2355 2356Send traffic from the guest to QEMU's standard output. @option{console} does not 2357take any options. 2358 2359@option{console} is only available on Windows hosts. 2360 2361@item -chardev serial ,id=@var{id} ,path=@option{path} 2362 2363Send traffic from the guest to a serial device on the host. 2364 2365On Unix hosts serial will actually accept any tty device, 2366not only serial lines. 2367 2368@option{path} specifies the name of the serial device to open. 2369 2370@item -chardev pty ,id=@var{id} 2371 2372Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2373not take any options. 2374 2375@option{pty} is not available on Windows hosts. 2376 2377@item -chardev stdio ,id=@var{id} [,signal=on|off] 2378Connect to standard input and standard output of the QEMU process. 2379 2380@option{signal} controls if signals are enabled on the terminal, that includes 2381exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2382default, use @option{signal=off} to disable it. 2383 2384@option{stdio} is not available on Windows hosts. 2385 2386@item -chardev braille ,id=@var{id} 2387 2388Connect to a local BrlAPI server. @option{braille} does not take any options. 2389 2390@item -chardev tty ,id=@var{id} ,path=@var{path} 2391 2392@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2393DragonFlyBSD hosts. It is an alias for @option{serial}. 2394 2395@option{path} specifies the path to the tty. @option{path} is required. 2396 2397@item -chardev parallel ,id=@var{id} ,path=@var{path} 2398@itemx -chardev parport ,id=@var{id} ,path=@var{path} 2399 2400@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2401 2402Connect to a local parallel port. 2403 2404@option{path} specifies the path to the parallel port device. @option{path} is 2405required. 2406 2407@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2408 2409@option{spicevmc} is only available when spice support is built in. 2410 2411@option{debug} debug level for spicevmc 2412 2413@option{name} name of spice channel to connect to 2414 2415Connect to a spice virtual machine channel, such as vdiport. 2416 2417@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2418 2419@option{spiceport} is only available when spice support is built in. 2420 2421@option{debug} debug level for spicevmc 2422 2423@option{name} name of spice port to connect to 2424 2425Connect to a spice port, allowing a Spice client to handle the traffic 2426identified by a name (preferably a fqdn). 2427ETEXI 2428 2429STEXI 2430@end table 2431ETEXI 2432DEFHEADING() 2433 2434DEFHEADING(Device URL Syntax:) 2435STEXI 2436 2437In addition to using normal file images for the emulated storage devices, 2438QEMU can also use networked resources such as iSCSI devices. These are 2439specified using a special URL syntax. 2440 2441@table @option 2442@item iSCSI 2443iSCSI support allows QEMU to access iSCSI resources directly and use as 2444images for the guest storage. Both disk and cdrom images are supported. 2445 2446Syntax for specifying iSCSI LUNs is 2447``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>'' 2448 2449By default qemu will use the iSCSI initiator-name 2450'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command 2451line or a configuration file. 2452 2453Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect 2454stalled requests and force a reestablishment of the session. The timeout 2455is specified in seconds. The default is 0 which means no timeout. Libiscsi 24561.15.0 or greater is required for this feature. 2457 2458Example (without authentication): 2459@example 2460qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \ 2461 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \ 2462 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2463@end example 2464 2465Example (CHAP username/password via URL): 2466@example 2467qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1 2468@end example 2469 2470Example (CHAP username/password via environment variables): 2471@example 2472LIBISCSI_CHAP_USERNAME="user" \ 2473LIBISCSI_CHAP_PASSWORD="password" \ 2474qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2475@end example 2476 2477iSCSI support is an optional feature of QEMU and only available when 2478compiled and linked against libiscsi. 2479ETEXI 2480DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 2481 "-iscsi [user=user][,password=password]\n" 2482 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 2483 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2484 " [,timeout=timeout]\n" 2485 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2486STEXI 2487 2488iSCSI parameters such as username and password can also be specified via 2489a configuration file. See qemu-doc for more information and examples. 2490 2491@item NBD 2492QEMU supports NBD (Network Block Devices) both using TCP protocol as well 2493as Unix Domain Sockets. 2494 2495Syntax for specifying a NBD device using TCP 2496``nbd:<server-ip>:<port>[:exportname=<export>]'' 2497 2498Syntax for specifying a NBD device using Unix Domain Sockets 2499``nbd:unix:<domain-socket>[:exportname=<export>]'' 2500 2501 2502Example for TCP 2503@example 2504qemu-system-i386 --drive file=nbd:192.0.2.1:30000 2505@end example 2506 2507Example for Unix Domain Sockets 2508@example 2509qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket 2510@end example 2511 2512@item SSH 2513QEMU supports SSH (Secure Shell) access to remote disks. 2514 2515Examples: 2516@example 2517qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img 2518qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img 2519@end example 2520 2521Currently authentication must be done using ssh-agent. Other 2522authentication methods may be supported in future. 2523 2524@item Sheepdog 2525Sheepdog is a distributed storage system for QEMU. 2526QEMU supports using either local sheepdog devices or remote networked 2527devices. 2528 2529Syntax for specifying a sheepdog device 2530@example 2531sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag] 2532@end example 2533 2534Example 2535@example 2536qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine 2537@end example 2538 2539See also @url{http://http://www.osrg.net/sheepdog/}. 2540 2541@item GlusterFS 2542GlusterFS is an user space distributed file system. 2543QEMU supports the use of GlusterFS volumes for hosting VM disk images using 2544TCP, Unix Domain Sockets and RDMA transport protocols. 2545 2546Syntax for specifying a VM disk image on GlusterFS volume is 2547@example 2548gluster[+transport]://[server[:port]]/volname/image[?socket=...] 2549@end example 2550 2551 2552Example 2553@example 2554qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img 2555@end example 2556 2557See also @url{http://www.gluster.org}. 2558 2559@item HTTP/HTTPS/FTP/FTPS/TFTP 2560QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp. 2561 2562Syntax using a single filename: 2563@example 2564<protocol>://[<username>[:<password>]@@]<host>/<path> 2565@end example 2566 2567where: 2568@table @option 2569@item protocol 2570'http', 'https', 'ftp', 'ftps', or 'tftp'. 2571 2572@item username 2573Optional username for authentication to the remote server. 2574 2575@item password 2576Optional password for authentication to the remote server. 2577 2578@item host 2579Address of the remote server. 2580 2581@item path 2582Path on the remote server, including any query string. 2583@end table 2584 2585The following options are also supported: 2586@table @option 2587@item url 2588The full URL when passing options to the driver explicitly. 2589 2590@item readahead 2591The amount of data to read ahead with each range request to the remote server. 2592This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it 2593does not have a suffix, it will be assumed to be in bytes. The value must be a 2594multiple of 512 bytes. It defaults to 256k. 2595 2596@item sslverify 2597Whether to verify the remote server's certificate when connecting over SSL. It 2598can have the value 'on' or 'off'. It defaults to 'on'. 2599 2600@item cookie 2601Send this cookie (it can also be a list of cookies separated by ';') with 2602each outgoing request. Only supported when using protocols such as HTTP 2603which support cookies, otherwise ignored. 2604 2605@item timeout 2606Set the timeout in seconds of the CURL connection. This timeout is the time 2607that CURL waits for a response from the remote server to get the size of the 2608image to be downloaded. If not set, the default timeout of 5 seconds is used. 2609@end table 2610 2611Note that when passing options to qemu explicitly, @option{driver} is the value 2612of <protocol>. 2613 2614Example: boot from a remote Fedora 20 live ISO image 2615@example 2616qemu-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 2617 2618qemu-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 2619@end example 2620 2621Example: boot from a remote Fedora 20 cloud image using a local overlay for 2622writes, copy-on-read, and a readahead of 64k 2623@example 2624qemu-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 2625 2626qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on 2627@end example 2628 2629Example: boot from an image stored on a VMware vSphere server with a self-signed 2630certificate using a local overlay for writes, a readahead of 64k and a timeout 2631of 10 seconds. 2632@example 2633qemu-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 2634 2635qemu-system-x86_64 -drive file=/tmp/test.qcow2 2636@end example 2637ETEXI 2638 2639STEXI 2640@end table 2641ETEXI 2642 2643DEFHEADING(Bluetooth(R) options:) 2644STEXI 2645@table @option 2646ETEXI 2647 2648DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 2649 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 2650 "-bt hci,host[:id]\n" \ 2651 " use host's HCI with the given name\n" \ 2652 "-bt hci[,vlan=n]\n" \ 2653 " emulate a standard HCI in virtual scatternet 'n'\n" \ 2654 "-bt vhci[,vlan=n]\n" \ 2655 " add host computer to virtual scatternet 'n' using VHCI\n" \ 2656 "-bt device:dev[,vlan=n]\n" \ 2657 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 2658 QEMU_ARCH_ALL) 2659STEXI 2660@item -bt hci[...] 2661@findex -bt 2662Defines the function of the corresponding Bluetooth HCI. -bt options 2663are matched with the HCIs present in the chosen machine type. For 2664example when emulating a machine with only one HCI built into it, only 2665the first @code{-bt hci[...]} option is valid and defines the HCI's 2666logic. The Transport Layer is decided by the machine type. Currently 2667the machines @code{n800} and @code{n810} have one HCI and all other 2668machines have none. 2669 2670@anchor{bt-hcis} 2671The following three types are recognized: 2672 2673@table @option 2674@item -bt hci,null 2675(default) The corresponding Bluetooth HCI assumes no internal logic 2676and will not respond to any HCI commands or emit events. 2677 2678@item -bt hci,host[:@var{id}] 2679(@code{bluez} only) The corresponding HCI passes commands / events 2680to / from the physical HCI identified by the name @var{id} (default: 2681@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 2682capable systems like Linux. 2683 2684@item -bt hci[,vlan=@var{n}] 2685Add a virtual, standard HCI that will participate in the Bluetooth 2686scatternet @var{n} (default @code{0}). Similarly to @option{-net} 2687VLANs, devices inside a bluetooth network @var{n} can only communicate 2688with other devices in the same network (scatternet). 2689@end table 2690 2691@item -bt vhci[,vlan=@var{n}] 2692(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 2693to the host bluetooth stack instead of to the emulated target. This 2694allows the host and target machines to participate in a common scatternet 2695and communicate. Requires the Linux @code{vhci} driver installed. Can 2696be used as following: 2697 2698@example 2699qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 2700@end example 2701 2702@item -bt device:@var{dev}[,vlan=@var{n}] 2703Emulate a bluetooth device @var{dev} and place it in network @var{n} 2704(default @code{0}). QEMU can only emulate one type of bluetooth devices 2705currently: 2706 2707@table @option 2708@item keyboard 2709Virtual wireless keyboard implementing the HIDP bluetooth profile. 2710@end table 2711ETEXI 2712 2713STEXI 2714@end table 2715ETEXI 2716DEFHEADING() 2717 2718#ifdef CONFIG_TPM 2719DEFHEADING(TPM device options:) 2720 2721DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 2722 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 2723 " use path to provide path to a character device; default is /dev/tpm0\n" 2724 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 2725 " not provided it will be searched for in /sys/class/misc/tpm?/device\n", 2726 QEMU_ARCH_ALL) 2727STEXI 2728 2729The general form of a TPM device option is: 2730@table @option 2731 2732@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] 2733@findex -tpmdev 2734Backend type must be: 2735@option{passthrough}. 2736 2737The specific backend type will determine the applicable options. 2738The @code{-tpmdev} option creates the TPM backend and requires a 2739@code{-device} option that specifies the TPM frontend interface model. 2740 2741Options to each backend are described below. 2742 2743Use 'help' to print all available TPM backend types. 2744@example 2745qemu -tpmdev help 2746@end example 2747 2748@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path} 2749 2750(Linux-host only) Enable access to the host's TPM using the passthrough 2751driver. 2752 2753@option{path} specifies the path to the host's TPM device, i.e., on 2754a Linux host this would be @code{/dev/tpm0}. 2755@option{path} is optional and by default @code{/dev/tpm0} is used. 2756 2757@option{cancel-path} specifies the path to the host TPM device's sysfs 2758entry allowing for cancellation of an ongoing TPM command. 2759@option{cancel-path} is optional and by default QEMU will search for the 2760sysfs entry to use. 2761 2762Some notes about using the host's TPM with the passthrough driver: 2763 2764The TPM device accessed by the passthrough driver must not be 2765used by any other application on the host. 2766 2767Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 2768the VM's firmware (BIOS/UEFI) will not be able to initialize the 2769TPM again and may therefore not show a TPM-specific menu that would 2770otherwise allow the user to configure the TPM, e.g., allow the user to 2771enable/disable or activate/deactivate the TPM. 2772Further, if TPM ownership is released from within a VM then the host's TPM 2773will get disabled and deactivated. To enable and activate the 2774TPM again afterwards, the host has to be rebooted and the user is 2775required to enter the firmware's menu to enable and activate the TPM. 2776If the TPM is left disabled and/or deactivated most TPM commands will fail. 2777 2778To create a passthrough TPM use the following two options: 2779@example 2780-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 2781@end example 2782Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 2783@code{tpmdev=tpm0} in the device option. 2784 2785@end table 2786 2787ETEXI 2788 2789DEFHEADING() 2790 2791#endif 2792 2793DEFHEADING(Linux/Multiboot boot specific:) 2794STEXI 2795 2796When using these options, you can use a given Linux or Multiboot 2797kernel without installing it in the disk image. It can be useful 2798for easier testing of various kernels. 2799 2800@table @option 2801ETEXI 2802 2803DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 2804 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 2805STEXI 2806@item -kernel @var{bzImage} 2807@findex -kernel 2808Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 2809or in multiboot format. 2810ETEXI 2811 2812DEF("append", HAS_ARG, QEMU_OPTION_append, \ 2813 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 2814STEXI 2815@item -append @var{cmdline} 2816@findex -append 2817Use @var{cmdline} as kernel command line 2818ETEXI 2819 2820DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 2821 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 2822STEXI 2823@item -initrd @var{file} 2824@findex -initrd 2825Use @var{file} as initial ram disk. 2826 2827@item -initrd "@var{file1} arg=foo,@var{file2}" 2828 2829This syntax is only available with multiboot. 2830 2831Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 2832first module. 2833ETEXI 2834 2835DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 2836 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 2837STEXI 2838@item -dtb @var{file} 2839@findex -dtb 2840Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 2841on boot. 2842ETEXI 2843 2844STEXI 2845@end table 2846ETEXI 2847DEFHEADING() 2848 2849DEFHEADING(Debug/Expert options:) 2850STEXI 2851@table @option 2852ETEXI 2853 2854DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 2855 "-fw_cfg [name=]<name>,file=<file>\n" 2856 " add named fw_cfg entry from file\n" 2857 "-fw_cfg [name=]<name>,string=<str>\n" 2858 " add named fw_cfg entry from string\n", 2859 QEMU_ARCH_ALL) 2860STEXI 2861@item -fw_cfg [name=]@var{name},file=@var{file} 2862@findex -fw_cfg 2863Add named fw_cfg entry from file. @var{name} determines the name of 2864the entry in the fw_cfg file directory exposed to the guest. 2865 2866@item -fw_cfg [name=]@var{name},string=@var{str} 2867Add named fw_cfg entry from string. 2868ETEXI 2869 2870DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 2871 "-serial dev redirect the serial port to char device 'dev'\n", 2872 QEMU_ARCH_ALL) 2873STEXI 2874@item -serial @var{dev} 2875@findex -serial 2876Redirect the virtual serial port to host character device 2877@var{dev}. The default device is @code{vc} in graphical mode and 2878@code{stdio} in non graphical mode. 2879 2880This option can be used several times to simulate up to 4 serial 2881ports. 2882 2883Use @code{-serial none} to disable all serial ports. 2884 2885Available character devices are: 2886@table @option 2887@item vc[:@var{W}x@var{H}] 2888Virtual console. Optionally, a width and height can be given in pixel with 2889@example 2890vc:800x600 2891@end example 2892It is also possible to specify width or height in characters: 2893@example 2894vc:80Cx24C 2895@end example 2896@item pty 2897[Linux only] Pseudo TTY (a new PTY is automatically allocated) 2898@item none 2899No device is allocated. 2900@item null 2901void device 2902@item chardev:@var{id} 2903Use a named character device defined with the @code{-chardev} option. 2904@item /dev/XXX 2905[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 2906parameters are set according to the emulated ones. 2907@item /dev/parport@var{N} 2908[Linux only, parallel port only] Use host parallel port 2909@var{N}. Currently SPP and EPP parallel port features can be used. 2910@item file:@var{filename} 2911Write output to @var{filename}. No character can be read. 2912@item stdio 2913[Unix only] standard input/output 2914@item pipe:@var{filename} 2915name pipe @var{filename} 2916@item COM@var{n} 2917[Windows only] Use host serial port @var{n} 2918@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 2919This implements UDP Net Console. 2920When @var{remote_host} or @var{src_ip} are not specified 2921they default to @code{0.0.0.0}. 2922When not using a specified @var{src_port} a random port is automatically chosen. 2923 2924If you just want a simple readonly console you can use @code{netcat} or 2925@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 2926@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 2927will appear in the netconsole session. 2928 2929If you plan to send characters back via netconsole or you want to stop 2930and start QEMU a lot of times, you should have QEMU use the same 2931source port each time by using something like @code{-serial 2932udp::4555@@:4556} to QEMU. Another approach is to use a patched 2933version of netcat which can listen to a TCP port and send and receive 2934characters via udp. If you have a patched version of netcat which 2935activates telnet remote echo and single char transfer, then you can 2936use the following options to step up a netcat redirector to allow 2937telnet on port 5555 to access the QEMU port. 2938@table @code 2939@item QEMU Options: 2940-serial udp::4555@@:4556 2941@item netcat options: 2942-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 2943@item telnet options: 2944localhost 5555 2945@end table 2946 2947@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 2948The TCP Net Console has two modes of operation. It can send the serial 2949I/O to a location or wait for a connection from a location. By default 2950the TCP Net Console is sent to @var{host} at the @var{port}. If you use 2951the @var{server} option QEMU will wait for a client socket application 2952to connect to the port before continuing, unless the @code{nowait} 2953option was specified. The @code{nodelay} option disables the Nagle buffering 2954algorithm. The @code{reconnect} option only applies if @var{noserver} is 2955set, if the connection goes down it will attempt to reconnect at the 2956given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 2957one TCP connection at a time is accepted. You can use @code{telnet} to 2958connect to the corresponding character device. 2959@table @code 2960@item Example to send tcp console to 192.168.0.2 port 4444 2961-serial tcp:192.168.0.2:4444 2962@item Example to listen and wait on port 4444 for connection 2963-serial tcp::4444,server 2964@item Example to not wait and listen on ip 192.168.0.100 port 4444 2965-serial tcp:192.168.0.100:4444,server,nowait 2966@end table 2967 2968@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 2969The telnet protocol is used instead of raw tcp sockets. The options 2970work the same as if you had specified @code{-serial tcp}. The 2971difference is that the port acts like a telnet server or client using 2972telnet option negotiation. This will also allow you to send the 2973MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 2974sequence. Typically in unix telnet you do it with Control-] and then 2975type "send break" followed by pressing the enter key. 2976 2977@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 2978A unix domain socket is used instead of a tcp socket. The option works the 2979same as if you had specified @code{-serial tcp} except the unix domain socket 2980@var{path} is used for connections. 2981 2982@item mon:@var{dev_string} 2983This is a special option to allow the monitor to be multiplexed onto 2984another serial port. The monitor is accessed with key sequence of 2985@key{Control-a} and then pressing @key{c}. 2986@var{dev_string} should be any one of the serial devices specified 2987above. An example to multiplex the monitor onto a telnet server 2988listening on port 4444 would be: 2989@table @code 2990@item -serial mon:telnet::4444,server,nowait 2991@end table 2992When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 2993QEMU any more but will be passed to the guest instead. 2994 2995@item braille 2996Braille device. This will use BrlAPI to display the braille output on a real 2997or fake device. 2998 2999@item msmouse 3000Three button serial mouse. Configure the guest to use Microsoft protocol. 3001@end table 3002ETEXI 3003 3004DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3005 "-parallel dev redirect the parallel port to char device 'dev'\n", 3006 QEMU_ARCH_ALL) 3007STEXI 3008@item -parallel @var{dev} 3009@findex -parallel 3010Redirect the virtual parallel port to host device @var{dev} (same 3011devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3012be used to use hardware devices connected on the corresponding host 3013parallel port. 3014 3015This option can be used several times to simulate up to 3 parallel 3016ports. 3017 3018Use @code{-parallel none} to disable all parallel ports. 3019ETEXI 3020 3021DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3022 "-monitor dev redirect the monitor to char device 'dev'\n", 3023 QEMU_ARCH_ALL) 3024STEXI 3025@item -monitor @var{dev} 3026@findex -monitor 3027Redirect the monitor to host device @var{dev} (same devices as the 3028serial port). 3029The default device is @code{vc} in graphical mode and @code{stdio} in 3030non graphical mode. 3031Use @code{-monitor none} to disable the default monitor. 3032ETEXI 3033DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3034 "-qmp dev like -monitor but opens in 'control' mode\n", 3035 QEMU_ARCH_ALL) 3036STEXI 3037@item -qmp @var{dev} 3038@findex -qmp 3039Like -monitor but opens in 'control' mode. 3040ETEXI 3041DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3042 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3043 QEMU_ARCH_ALL) 3044STEXI 3045@item -qmp-pretty @var{dev} 3046@findex -qmp-pretty 3047Like -qmp but uses pretty JSON formatting. 3048ETEXI 3049 3050DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3051 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL) 3052STEXI 3053@item -mon [chardev=]name[,mode=readline|control][,default] 3054@findex -mon 3055Setup monitor on chardev @var{name}. 3056ETEXI 3057 3058DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3059 "-debugcon dev redirect the debug console to char device 'dev'\n", 3060 QEMU_ARCH_ALL) 3061STEXI 3062@item -debugcon @var{dev} 3063@findex -debugcon 3064Redirect the debug console to host device @var{dev} (same devices as the 3065serial port). The debug console is an I/O port which is typically port 30660xe9; writing to that I/O port sends output to this device. 3067The default device is @code{vc} in graphical mode and @code{stdio} in 3068non graphical mode. 3069ETEXI 3070 3071DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3072 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3073STEXI 3074@item -pidfile @var{file} 3075@findex -pidfile 3076Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3077from a script. 3078ETEXI 3079 3080DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3081 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3082STEXI 3083@item -singlestep 3084@findex -singlestep 3085Run the emulation in single step mode. 3086ETEXI 3087 3088DEF("S", 0, QEMU_OPTION_S, \ 3089 "-S freeze CPU at startup (use 'c' to start execution)\n", 3090 QEMU_ARCH_ALL) 3091STEXI 3092@item -S 3093@findex -S 3094Do not start CPU at startup (you must type 'c' in the monitor). 3095ETEXI 3096 3097DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3098 "-realtime [mlock=on|off]\n" 3099 " run qemu with realtime features\n" 3100 " mlock=on|off controls mlock support (default: on)\n", 3101 QEMU_ARCH_ALL) 3102STEXI 3103@item -realtime mlock=on|off 3104@findex -realtime 3105Run qemu with realtime features. 3106mlocking qemu and guest memory can be enabled via @option{mlock=on} 3107(enabled by default). 3108ETEXI 3109 3110DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3111 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3112STEXI 3113@item -gdb @var{dev} 3114@findex -gdb 3115Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3116connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3117stdio are reasonable use case. The latter is allowing to start QEMU from 3118within gdb and establish the connection via a pipe: 3119@example 3120(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3121@end example 3122ETEXI 3123 3124DEF("s", 0, QEMU_OPTION_s, \ 3125 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3126 QEMU_ARCH_ALL) 3127STEXI 3128@item -s 3129@findex -s 3130Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3131(@pxref{gdb_usage}). 3132ETEXI 3133 3134DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3135 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3136 QEMU_ARCH_ALL) 3137STEXI 3138@item -d @var{item1}[,...] 3139@findex -d 3140Enable logging of specified items. Use '-d help' for a list of log items. 3141ETEXI 3142 3143DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3144 "-D logfile output log to logfile (default stderr)\n", 3145 QEMU_ARCH_ALL) 3146STEXI 3147@item -D @var{logfile} 3148@findex -D 3149Output log in @var{logfile} instead of to stderr 3150ETEXI 3151 3152DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3153 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3154 QEMU_ARCH_ALL) 3155STEXI 3156@item -L @var{path} 3157@findex -L 3158Set the directory for the BIOS, VGA BIOS and keymaps. 3159ETEXI 3160 3161DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3162 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3163STEXI 3164@item -bios @var{file} 3165@findex -bios 3166Set the filename for the BIOS. 3167ETEXI 3168 3169DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3170 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3171STEXI 3172@item -enable-kvm 3173@findex -enable-kvm 3174Enable KVM full virtualization support. This option is only available 3175if KVM support is enabled when compiling. 3176ETEXI 3177 3178DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3179 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3180DEF("xen-create", 0, QEMU_OPTION_xen_create, 3181 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3182 " warning: should not be used when xend is in use\n", 3183 QEMU_ARCH_ALL) 3184DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3185 "-xen-attach attach to existing xen domain\n" 3186 " xend will use this when starting QEMU\n", 3187 QEMU_ARCH_ALL) 3188STEXI 3189@item -xen-domid @var{id} 3190@findex -xen-domid 3191Specify xen guest domain @var{id} (XEN only). 3192@item -xen-create 3193@findex -xen-create 3194Create domain using xen hypercalls, bypassing xend. 3195Warning: should not be used when xend is in use (XEN only). 3196@item -xen-attach 3197@findex -xen-attach 3198Attach to existing xen domain. 3199xend will use this when starting QEMU (XEN only). 3200ETEXI 3201 3202DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3203 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3204STEXI 3205@item -no-reboot 3206@findex -no-reboot 3207Exit instead of rebooting. 3208ETEXI 3209 3210DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3211 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3212STEXI 3213@item -no-shutdown 3214@findex -no-shutdown 3215Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3216This allows for instance switching to monitor to commit changes to the 3217disk image. 3218ETEXI 3219 3220DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3221 "-loadvm [tag|id]\n" \ 3222 " start right away with a saved state (loadvm in monitor)\n", 3223 QEMU_ARCH_ALL) 3224STEXI 3225@item -loadvm @var{file} 3226@findex -loadvm 3227Start right away with a saved state (@code{loadvm} in monitor) 3228ETEXI 3229 3230#ifndef _WIN32 3231DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3232 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3233#endif 3234STEXI 3235@item -daemonize 3236@findex -daemonize 3237Daemonize the QEMU process after initialization. QEMU will not detach from 3238standard IO until it is ready to receive connections on any of its devices. 3239This option is a useful way for external programs to launch QEMU without having 3240to cope with initialization race conditions. 3241ETEXI 3242 3243DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3244 "-option-rom rom load a file, rom, into the option ROM space\n", 3245 QEMU_ARCH_ALL) 3246STEXI 3247@item -option-rom @var{file} 3248@findex -option-rom 3249Load the contents of @var{file} as an option ROM. 3250This option is useful to load things like EtherBoot. 3251ETEXI 3252 3253HXCOMM Silently ignored for compatibility 3254DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3255 3256HXCOMM Options deprecated by -rtc 3257DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3258DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3259 3260DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3261 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3262 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3263 QEMU_ARCH_ALL) 3264 3265STEXI 3266 3267@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3268@findex -rtc 3269Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3270UTC or local time, respectively. @code{localtime} is required for correct date in 3271MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3272format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3273 3274By default the RTC is driven by the host system time. This allows using of the 3275RTC as accurate reference clock inside the guest, specifically if the host 3276time is smoothly following an accurate external reference clock, e.g. via NTP. 3277If you want to isolate the guest time from the host, you can set @option{clock} 3278to @code{rt} instead. To even prevent it from progressing during suspension, 3279you can set it to @code{vm}. 3280 3281Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3282specifically with Windows' ACPI HAL. This option will try to figure out how 3283many timer interrupts were not processed by the Windows guest and will 3284re-inject them. 3285ETEXI 3286 3287DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3288 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>]\n" \ 3289 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3290 " instruction, enable aligning the host and virtual clocks\n" \ 3291 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3292STEXI 3293@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}] 3294@findex -icount 3295Enable virtual instruction counter. The virtual cpu will execute one 3296instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3297then the virtual cpu speed will be automatically adjusted to keep virtual 3298time within a few seconds of real time. 3299 3300When the virtual cpu is sleeping, the virtual time will advance at default 3301speed unless @option{sleep=on|off} is specified. 3302With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3303instantly whenever the virtual cpu goes to sleep mode and will not advance 3304if no timer is enabled. This behavior give deterministic execution times from 3305the guest point of view. 3306 3307Note that while this option can give deterministic behavior, it does not 3308provide cycle accurate emulation. Modern CPUs contain superscalar out of 3309order cores with complex cache hierarchies. The number of instructions 3310executed often has little or no correlation with actual performance. 3311 3312@option{align=on} will activate the delay algorithm which will try 3313to synchronise the host clock and the virtual clock. The goal is to 3314have a guest running at the real frequency imposed by the shift option. 3315Whenever the guest clock is behind the host clock and if 3316@option{align=on} is specified then we print a message to the user 3317to inform about the delay. 3318Currently this option does not work when @option{shift} is @code{auto}. 3319Note: The sync algorithm will work for those shift values for which 3320the guest clock runs ahead of the host clock. Typically this happens 3321when the shift value is high (how high depends on the host machine). 3322 3323When @option{rr} option is specified deterministic record/replay is enabled. 3324Replay log is written into @var{filename} file in record mode and 3325read from this file in replay mode. 3326ETEXI 3327 3328DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3329 "-watchdog model\n" \ 3330 " enable virtual hardware watchdog [default=none]\n", 3331 QEMU_ARCH_ALL) 3332STEXI 3333@item -watchdog @var{model} 3334@findex -watchdog 3335Create a virtual hardware watchdog device. Once enabled (by a guest 3336action), the watchdog must be periodically polled by an agent inside 3337the guest or else the guest will be restarted. Choose a model for 3338which your guest has drivers. 3339 3340The @var{model} is the model of hardware watchdog to emulate. Use 3341@code{-watchdog help} to list available hardware models. Only one 3342watchdog can be enabled for a guest. 3343 3344The following models may be available: 3345@table @option 3346@item ib700 3347iBASE 700 is a very simple ISA watchdog with a single timer. 3348@item i6300esb 3349Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3350dual-timer watchdog. 3351@item diag288 3352A virtual watchdog for s390x backed by the diagnose 288 hypercall 3353(currently KVM only). 3354@end table 3355ETEXI 3356 3357DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3358 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \ 3359 " action when watchdog fires [default=reset]\n", 3360 QEMU_ARCH_ALL) 3361STEXI 3362@item -watchdog-action @var{action} 3363@findex -watchdog-action 3364 3365The @var{action} controls what QEMU will do when the watchdog timer 3366expires. 3367The default is 3368@code{reset} (forcefully reset the guest). 3369Other possible actions are: 3370@code{shutdown} (attempt to gracefully shutdown the guest), 3371@code{poweroff} (forcefully poweroff the guest), 3372@code{pause} (pause the guest), 3373@code{debug} (print a debug message and continue), or 3374@code{none} (do nothing). 3375 3376Note that the @code{shutdown} action requires that the guest responds 3377to ACPI signals, which it may not be able to do in the sort of 3378situations where the watchdog would have expired, and thus 3379@code{-watchdog-action shutdown} is not recommended for production use. 3380 3381Examples: 3382 3383@table @code 3384@item -watchdog i6300esb -watchdog-action pause 3385@itemx -watchdog ib700 3386@end table 3387ETEXI 3388 3389DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3390 "-echr chr set terminal escape character instead of ctrl-a\n", 3391 QEMU_ARCH_ALL) 3392STEXI 3393 3394@item -echr @var{numeric_ascii_value} 3395@findex -echr 3396Change the escape character used for switching to the monitor when using 3397monitor and serial sharing. The default is @code{0x01} when using the 3398@code{-nographic} option. @code{0x01} is equal to pressing 3399@code{Control-a}. You can select a different character from the ascii 3400control keys where 1 through 26 map to Control-a through Control-z. For 3401instance you could use the either of the following to change the escape 3402character to Control-t. 3403@table @code 3404@item -echr 0x14 3405@itemx -echr 20 3406@end table 3407ETEXI 3408 3409DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3410 "-virtioconsole c\n" \ 3411 " set virtio console\n", QEMU_ARCH_ALL) 3412STEXI 3413@item -virtioconsole @var{c} 3414@findex -virtioconsole 3415Set virtio console. 3416 3417This option is maintained for backward compatibility. 3418 3419Please use @code{-device virtconsole} for the new way of invocation. 3420ETEXI 3421 3422DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3423 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3424STEXI 3425@item -show-cursor 3426@findex -show-cursor 3427Show cursor. 3428ETEXI 3429 3430DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3431 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3432STEXI 3433@item -tb-size @var{n} 3434@findex -tb-size 3435Set TB size. 3436ETEXI 3437 3438DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3439 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3440 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3441 "-incoming unix:socketpath\n" \ 3442 " prepare for incoming migration, listen on\n" \ 3443 " specified protocol and socket address\n" \ 3444 "-incoming fd:fd\n" \ 3445 "-incoming exec:cmdline\n" \ 3446 " accept incoming migration on given file descriptor\n" \ 3447 " or from given external command\n" \ 3448 "-incoming defer\n" \ 3449 " wait for the URI to be specified via migrate_incoming\n", 3450 QEMU_ARCH_ALL) 3451STEXI 3452@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3453@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3454@findex -incoming 3455Prepare for incoming migration, listen on a given tcp port. 3456 3457@item -incoming unix:@var{socketpath} 3458Prepare for incoming migration, listen on a given unix socket. 3459 3460@item -incoming fd:@var{fd} 3461Accept incoming migration from a given filedescriptor. 3462 3463@item -incoming exec:@var{cmdline} 3464Accept incoming migration as an output from specified external command. 3465 3466@item -incoming defer 3467Wait for the URI to be specified via migrate_incoming. The monitor can 3468be used to change settings (such as migration parameters) prior to issuing 3469the migrate_incoming to allow the migration to begin. 3470ETEXI 3471 3472DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3473 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3474STEXI 3475@item -nodefaults 3476@findex -nodefaults 3477Don't create default devices. Normally, QEMU sets the default devices like serial 3478port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3479CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3480default devices. 3481ETEXI 3482 3483#ifndef _WIN32 3484DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3485 "-chroot dir chroot to dir just before starting the VM\n", 3486 QEMU_ARCH_ALL) 3487#endif 3488STEXI 3489@item -chroot @var{dir} 3490@findex -chroot 3491Immediately before starting guest execution, chroot to the specified 3492directory. Especially useful in combination with -runas. 3493ETEXI 3494 3495#ifndef _WIN32 3496DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3497 "-runas user change to user id user just before starting the VM\n", 3498 QEMU_ARCH_ALL) 3499#endif 3500STEXI 3501@item -runas @var{user} 3502@findex -runas 3503Immediately before starting guest execution, drop root privileges, switching 3504to the specified user. 3505ETEXI 3506 3507DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3508 "-prom-env variable=value\n" 3509 " set OpenBIOS nvram variables\n", 3510 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3511STEXI 3512@item -prom-env @var{variable}=@var{value} 3513@findex -prom-env 3514Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3515ETEXI 3516DEF("semihosting", 0, QEMU_OPTION_semihosting, 3517 "-semihosting semihosting mode\n", 3518 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3519 QEMU_ARCH_MIPS) 3520STEXI 3521@item -semihosting 3522@findex -semihosting 3523Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 3524ETEXI 3525DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 3526 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 3527 " semihosting configuration\n", 3528QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3529QEMU_ARCH_MIPS) 3530STEXI 3531@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 3532@findex -semihosting-config 3533Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 3534@table @option 3535@item target=@code{native|gdb|auto} 3536Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 3537or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 3538during debug sessions and @code{native} otherwise. 3539@item arg=@var{str1},arg=@var{str2},... 3540Allows the user to pass input arguments, and can be used multiple times to build 3541up a list. The old-style @code{-kernel}/@code{-append} method of passing a 3542command line is still supported for backward compatibility. If both the 3543@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 3544specified, the former is passed to semihosting as it always takes precedence. 3545@end table 3546ETEXI 3547DEF("old-param", 0, QEMU_OPTION_old_param, 3548 "-old-param old param mode\n", QEMU_ARCH_ARM) 3549STEXI 3550@item -old-param 3551@findex -old-param (ARM) 3552Old param mode (ARM only). 3553ETEXI 3554 3555DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 3556 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", 3557 QEMU_ARCH_ALL) 3558STEXI 3559@item -sandbox @var{arg} 3560@findex -sandbox 3561Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 3562disable it. The default is 'off'. 3563ETEXI 3564 3565DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 3566 "-readconfig <file>\n", QEMU_ARCH_ALL) 3567STEXI 3568@item -readconfig @var{file} 3569@findex -readconfig 3570Read device configuration from @var{file}. This approach is useful when you want to spawn 3571QEMU process with many command line options but you don't want to exceed the command line 3572character limit. 3573ETEXI 3574DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 3575 "-writeconfig <file>\n" 3576 " read/write config file\n", QEMU_ARCH_ALL) 3577STEXI 3578@item -writeconfig @var{file} 3579@findex -writeconfig 3580Write device configuration to @var{file}. The @var{file} can be either filename to save 3581command line and device configuration into file or dash @code{-}) character to print the 3582output to stdout. This can be later used as input file for @code{-readconfig} option. 3583ETEXI 3584DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, 3585 "-nodefconfig\n" 3586 " do not load default config files at startup\n", 3587 QEMU_ARCH_ALL) 3588STEXI 3589@item -nodefconfig 3590@findex -nodefconfig 3591Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup. 3592The @code{-nodefconfig} option will prevent QEMU from loading any of those config files. 3593ETEXI 3594DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 3595 "-no-user-config\n" 3596 " do not load user-provided config files at startup\n", 3597 QEMU_ARCH_ALL) 3598STEXI 3599@item -no-user-config 3600@findex -no-user-config 3601The @code{-no-user-config} option makes QEMU not load any of the user-provided 3602config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config 3603files from @var{datadir}. 3604ETEXI 3605DEF("trace", HAS_ARG, QEMU_OPTION_trace, 3606 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 3607 " specify tracing options\n", 3608 QEMU_ARCH_ALL) 3609STEXI 3610HXCOMM This line is not accurate, as some sub-options are backend-specific but 3611HXCOMM HX does not support conditional compilation of text. 3612@item -trace [events=@var{file}][,file=@var{file}] 3613@findex -trace 3614 3615Specify tracing options. 3616 3617@table @option 3618@item [enable=]@var{pattern} 3619Immediately enable events matching @var{pattern}. 3620The file must contain one event name (as listed in the @file{trace-events} file) 3621per line; globbing patterns are accepted too. This option is only 3622available if QEMU has been compiled with the @var{simple}, @var{stderr} 3623or @var{ftrace} tracing backend. To specify multiple events or patterns, 3624specify the @option{-trace} option multiple times. 3625 3626Use @code{-trace help} to print a list of names of trace points. 3627 3628@item events=@var{file} 3629Immediately enable events listed in @var{file}. 3630The file must contain one event name (as listed in the @file{trace-events} file) 3631per line; globbing patterns are accepted too. This option is only 3632available if QEMU has been compiled with the @var{simple}, @var{stderr} or 3633@var{ftrace} tracing backend. 3634 3635@item file=@var{file} 3636Log output traces to @var{file}. 3637This option is only available if QEMU has been compiled with 3638the @var{simple} tracing backend. 3639@end table 3640ETEXI 3641 3642HXCOMM Internal use 3643DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 3644DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 3645 3646#ifdef __linux__ 3647DEF("enable-fips", 0, QEMU_OPTION_enablefips, 3648 "-enable-fips enable FIPS 140-2 compliance\n", 3649 QEMU_ARCH_ALL) 3650#endif 3651STEXI 3652@item -enable-fips 3653@findex -enable-fips 3654Enable FIPS 140-2 compliance mode. 3655ETEXI 3656 3657HXCOMM Deprecated by -machine accel=tcg property 3658DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 3659 3660HXCOMM Deprecated by kvm-pit driver properties 3661DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, 3662 "", QEMU_ARCH_I386) 3663 3664HXCOMM Deprecated (ignored) 3665DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386) 3666 3667HXCOMM Deprecated by -machine kernel_irqchip=on|off property 3668DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386) 3669 3670HXCOMM Deprecated (ignored) 3671DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL) 3672 3673DEF("msg", HAS_ARG, QEMU_OPTION_msg, 3674 "-msg timestamp[=on|off]\n" 3675 " change the format of messages\n" 3676 " on|off controls leading timestamps (default:on)\n", 3677 QEMU_ARCH_ALL) 3678STEXI 3679@item -msg timestamp[=on|off] 3680@findex -msg 3681prepend a timestamp to each log message.(default:on) 3682ETEXI 3683 3684DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 3685 "-dump-vmstate <file>\n" 3686 " Output vmstate information in JSON format to file.\n" 3687 " Use the scripts/vmstate-static-checker.py file to\n" 3688 " check for possible regressions in migration code\n" 3689 " by comparing two such vmstate dumps.\n", 3690 QEMU_ARCH_ALL) 3691STEXI 3692@item -dump-vmstate @var{file} 3693@findex -dump-vmstate 3694Dump json-encoded vmstate information for current machine type to file 3695in @var{file} 3696ETEXI 3697 3698DEFHEADING(Generic object creation) 3699 3700DEF("object", HAS_ARG, QEMU_OPTION_object, 3701 "-object TYPENAME[,PROP1=VALUE1,...]\n" 3702 " create a new object of type TYPENAME setting properties\n" 3703 " in the order they are specified. Note that the 'id'\n" 3704 " property must be set. These objects are placed in the\n" 3705 " '/objects' path.\n", 3706 QEMU_ARCH_ALL) 3707STEXI 3708@item -object @var{typename}[,@var{prop1}=@var{value1},...] 3709@findex -object 3710Create a new object of type @var{typename} setting properties 3711in the order they are specified. Note that the 'id' 3712property must be set. These objects are placed in the 3713'/objects' path. 3714 3715@table @option 3716 3717@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off} 3718 3719Creates a memory file backend object, which can be used to back 3720the guest RAM with huge pages. The @option{id} parameter is a 3721unique ID that will be used to reference this memory region 3722when configuring the @option{-numa} argument. The @option{size} 3723option provides the size of the memory region, and accepts 3724common suffixes, eg @option{500M}. The @option{mem-path} provides 3725the path to either a shared memory or huge page filesystem mount. 3726The @option{share} boolean option determines whether the memory 3727region is marked as private to QEMU, or shared. The latter allows 3728a co-operating external process to access the QEMU memory region. 3729 3730@item -object rng-random,id=@var{id},filename=@var{/dev/random} 3731 3732Creates a random number generator backend which obtains entropy from 3733a device on the host. The @option{id} parameter is a unique ID that 3734will be used to reference this entropy backend from the @option{virtio-rng} 3735device. The @option{filename} parameter specifies which file to obtain 3736entropy from and if omitted defaults to @option{/dev/random}. 3737 3738@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 3739 3740Creates a random number generator backend which obtains entropy from 3741an external daemon running on the host. The @option{id} parameter is 3742a unique ID that will be used to reference this entropy backend from 3743the @option{virtio-rng} device. The @option{chardev} parameter is 3744the unique ID of a character device backend that provides the connection 3745to the RNG daemon. 3746 3747@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 3748 3749Creates a TLS anonymous credentials object, which can be used to provide 3750TLS support on network backends. The @option{id} parameter is a unique 3751ID which network backends will use to access the credentials. The 3752@option{endpoint} is either @option{server} or @option{client} depending 3753on whether the QEMU network backend that uses the credentials will be 3754acting as a client or as a server. If @option{verify-peer} is enabled 3755(the default) then once the handshake is completed, the peer credentials 3756will be verified, though this is a no-op for anonymous credentials. 3757 3758The @var{dir} parameter tells QEMU where to find the credential 3759files. For server endpoints, this directory may contain a file 3760@var{dh-params.pem} providing diffie-hellman parameters to use 3761for the TLS server. If the file is missing, QEMU will generate 3762a set of DH parameters at startup. This is a computationally 3763expensive operation that consumes random pool entropy, so it is 3764recommended that a persistent set of parameters be generated 3765upfront and saved. 3766 3767@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} 3768 3769Creates a TLS anonymous credentials object, which can be used to provide 3770TLS support on network backends. The @option{id} parameter is a unique 3771ID which network backends will use to access the credentials. The 3772@option{endpoint} is either @option{server} or @option{client} depending 3773on whether the QEMU network backend that uses the credentials will be 3774acting as a client or as a server. If @option{verify-peer} is enabled 3775(the default) then once the handshake is completed, the peer credentials 3776will be verified. With x509 certificates, this implies that the clients 3777must be provided with valid client certificates too. 3778 3779The @var{dir} parameter tells QEMU where to find the credential 3780files. For server endpoints, this directory may contain a file 3781@var{dh-params.pem} providing diffie-hellman parameters to use 3782for the TLS server. If the file is missing, QEMU will generate 3783a set of DH parameters at startup. This is a computationally 3784expensive operation that consumes random pool entropy, so it is 3785recommended that a persistent set of parameters be generated 3786upfront and saved. 3787 3788For x509 certificate credentials the directory will contain further files 3789providing the x509 certificates. The certificates must be stored 3790in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 3791@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 3792@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 3793 3794For the @var{server-key.pem} and @var{client-key.pem} files which 3795contain sensitive private keys, it is possible to use an encrypted 3796version by providing the @var{passwordid} parameter. This provides 3797the ID of a previously created @code{secret} object containing the 3798password for decryption. 3799 3800@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 3801 3802Interval @var{t} can't be 0, this filter batches the packet delivery: all 3803packets arriving in a given interval on netdev @var{netdevid} are delayed 3804until the end of the interval. Interval is in microseconds. 3805@option{status} is optional that indicate whether the netfilter is 3806on (enabled) or off (disabled), the default status for netfilter will be 'on'. 3807 3808queue @var{all|rx|tx} is an option that can be applied to any netfilter. 3809 3810@option{all}: the filter is attached both to the receive and the transmit 3811 queue of the netdev (default). 3812 3813@option{rx}: the filter is attached to the receive queue of the netdev, 3814 where it will receive packets sent to the netdev. 3815 3816@option{tx}: the filter is attached to the transmit queue of the netdev, 3817 where it will receive packets sent by the netdev. 3818 3819@item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}] 3820 3821Dump the network traffic on netdev @var{dev} to the file specified by 3822@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 3823The file format is libpcap, so it can be analyzed with tools such as tcpdump 3824or Wireshark. 3825 3826@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 3827@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 3828 3829Defines a secret to store a password, encryption key, or some other sensitive 3830data. The sensitive data can either be passed directly via the @var{data} 3831parameter, or indirectly via the @var{file} parameter. Using the @var{data} 3832parameter is insecure unless the sensitive data is encrypted. 3833 3834The sensitive data can be provided in raw format (the default), or base64. 3835When encoded as JSON, the raw format only supports valid UTF-8 characters, 3836so base64 is recommended for sending binary data. QEMU will convert from 3837which ever format is provided to the format it needs internally. eg, an 3838RBD password can be provided in raw format, even though it will be base64 3839encoded when passed onto the RBD sever. 3840 3841For added protection, it is possible to encrypt the data associated with 3842a secret using the AES-256-CBC cipher. Use of encryption is indicated 3843by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 3844parameter provides the ID of a previously defined secret that contains 3845the AES-256 decryption key. This key should be 32-bytes long and be 3846base64 encoded. The @var{iv} parameter provides the random initialization 3847vector used for encryption of this particular secret and should be a 3848base64 encrypted string of the 32-byte IV. 3849 3850The simplest (insecure) usage is to provide the secret inline 3851 3852@example 3853 3854 # $QEMU -object secret,id=sec0,data=letmein,format=raw 3855 3856@end example 3857 3858The simplest secure usage is to provide the secret via a file 3859 3860 # echo -n "letmein" > mypasswd.txt 3861 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 3862 3863For greater security, AES-256-CBC should be used. To illustrate usage, 3864consider the openssl command line tool which can encrypt the data. Note 3865that when encrypting, the plaintext must be padded to the cipher block 3866size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 3867 3868First a master key needs to be created in base64 encoding: 3869 3870@example 3871 # openssl rand -base64 32 > key.b64 3872 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 3873@end example 3874 3875Each secret to be encrypted needs to have a random initialization vector 3876generated. These do not need to be kept secret 3877 3878@example 3879 # openssl rand -base64 16 > iv.b64 3880 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 3881@end example 3882 3883The secret to be defined can now be encrypted, in this case we're 3884telling openssl to base64 encode the result, but it could be left 3885as raw bytes if desired. 3886 3887@example 3888 # SECRET=$(echo -n "letmein" | 3889 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 3890@end example 3891 3892When launching QEMU, create a master secret pointing to @code{key.b64} 3893and specify that to be used to decrypt the user password. Pass the 3894contents of @code{iv.b64} to the second secret 3895 3896@example 3897 # $QEMU \ 3898 -object secret,id=secmaster0,format=base64,file=key.b64 \ 3899 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 3900 data=$SECRET,iv=$(<iv.b64) 3901@end example 3902 3903@end table 3904 3905ETEXI 3906 3907 3908HXCOMM This is the last statement. Insert new options before this line! 3909STEXI 3910@end table 3911ETEXI 3912
