qemu/qemu-options.hx
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   1HXCOMM Use DEFHEADING() to define headings in both help text and texi
   2HXCOMM Text between STEXI and ETEXI are copied to texi version and
   3HXCOMM discarded from C version
   4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to
   5HXCOMM construct option structures, enums and help message for specified
   6HXCOMM architectures.
   7HXCOMM HXCOMM can be used for comments, discarded from both texi and C
   8
   9DEFHEADING(Standard options:)
  10STEXI
  11@table @option
  12ETEXI
  13
  14DEF("help", 0, QEMU_OPTION_h,
  15    "-h or -help     display this help and exit\n", QEMU_ARCH_ALL)
  16STEXI
  17@item -h
  18@findex -h
  19Display help and exit
  20ETEXI
  21
  22DEF("version", 0, QEMU_OPTION_version,
  23    "-version        display version information and exit\n", QEMU_ARCH_ALL)
  24STEXI
  25@item -version
  26@findex -version
  27Display version information and exit
  28ETEXI
  29
  30DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
  31    "-machine [type=]name[,prop[=value][,...]]\n"
  32    "                selects emulated machine ('-machine help' for list)\n"
  33    "                property accel=accel1[:accel2[:...]] selects accelerator\n"
  34    "                supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n"
  35    "                kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
  36    "                vmport=on|off|auto controls emulation of vmport (default: auto)\n"
  37    "                kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
  38    "                dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
  39    "                mem-merge=on|off controls memory merge support (default: on)\n"
  40    "                igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
  41    "                aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
  42    "                dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
  43    "                suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
  44    "                nvdimm=on|off controls NVDIMM support (default=off)\n"
  45    "                enforce-config-section=on|off enforce configuration section migration (default=off)\n"
  46    "                s390-squash-mcss=on|off (deprecated) controls support for squashing into default css (default=off)\n"
  47    "                memory-encryption=@var{} memory encryption object to use (default=none)\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.
  54
  55For architectures which aim to support live migration compatibility
  56across releases, each release will introduce a new versioned machine
  57type. For example, the 2.8.0 release introduced machine types
  58``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures.
  59
  60To allow live migration of guests from QEMU version 2.8.0, to QEMU
  61version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8''
  62and ``pc-q35-2.8'' machines too. To allow users live migrating VMs
  63to skip multiple intermediate releases when upgrading, new releases
  64of QEMU will support machine types from many previous versions.
  65
  66Supported machine properties are:
  67@table @option
  68@item accel=@var{accels1}[:@var{accels2}[:...]]
  69This is used to enable an accelerator. Depending on the target architecture,
  70kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
  71more than one accelerator specified, the next one is used if the previous one
  72fails to initialize.
  73@item kernel_irqchip=on|off
  74Controls in-kernel irqchip support for the chosen accelerator when available.
  75@item gfx_passthru=on|off
  76Enables IGD GFX passthrough support for the chosen machine when available.
  77@item vmport=on|off|auto
  78Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
  79value based on accel. For accel=xen the default is off otherwise the default
  80is on.
  81@item kvm_shadow_mem=size
  82Defines the size of the KVM shadow MMU.
  83@item dump-guest-core=on|off
  84Include guest memory in a core dump. The default is on.
  85@item mem-merge=on|off
  86Enables or disables memory merge support. This feature, when supported by
  87the host, de-duplicates identical memory pages among VMs instances
  88(enabled by default).
  89@item aes-key-wrap=on|off
  90Enables or disables AES key wrapping support on s390-ccw hosts. This feature
  91controls whether AES wrapping keys will be created to allow
  92execution of AES cryptographic functions.  The default is on.
  93@item dea-key-wrap=on|off
  94Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
  95controls whether DEA wrapping keys will be created to allow
  96execution of DEA cryptographic functions.  The default is on.
  97@item nvdimm=on|off
  98Enables or disables NVDIMM support. The default is off.
  99@item s390-squash-mcss=on|off
 100Enables or disables squashing subchannels into the default css.
 101The default is off.
 102NOTE: This property is deprecated and will be removed in future releases.
 103The ``s390-squash-mcss=on`` property has been obsoleted by allowing the
 104cssid to be chosen freely. Instead of squashing subchannels into the
 105default channel subsystem image for guests that do not support multiple
 106channel subsystems, all devices can be put into the default channel
 107subsystem image.
 108@item enforce-config-section=on|off
 109If @option{enforce-config-section} is set to @var{on}, force migration
 110code to send configuration section even if the machine-type sets the
 111@option{migration.send-configuration} property to @var{off}.
 112NOTE: this parameter is deprecated. Please use @option{-global}
 113@option{migration.send-configuration}=@var{on|off} instead.
 114@item memory-encryption=@var{}
 115Memory encryption object to use. The default is none.
 116@end table
 117ETEXI
 118
 119HXCOMM Deprecated by -machine
 120DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
 121
 122DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
 123    "-cpu cpu        select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
 124STEXI
 125@item -cpu @var{model}
 126@findex -cpu
 127Select CPU model (@code{-cpu help} for list and additional feature selection)
 128ETEXI
 129
 130DEF("accel", HAS_ARG, QEMU_OPTION_accel,
 131    "-accel [accel=]accelerator[,thread=single|multi]\n"
 132    "                select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n"
 133    "                thread=single|multi (enable multi-threaded TCG)", QEMU_ARCH_ALL)
 134STEXI
 135@item -accel @var{name}[,prop=@var{value}[,...]]
 136@findex -accel
 137This is used to enable an accelerator. Depending on the target architecture,
 138kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is
 139more than one accelerator specified, the next one is used if the previous one
 140fails to initialize.
 141@table @option
 142@item thread=single|multi
 143Controls number of TCG threads. When the TCG is multi-threaded there will be one
 144thread per vCPU therefor taking advantage of additional host cores. The default
 145is to enable multi-threading where both the back-end and front-ends support it and
 146no incompatible TCG features have been enabled (e.g. icount/replay).
 147@end table
 148ETEXI
 149
 150DEF("smp", HAS_ARG, QEMU_OPTION_smp,
 151    "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
 152    "                set the number of CPUs to 'n' [default=1]\n"
 153    "                maxcpus= maximum number of total cpus, including\n"
 154    "                offline CPUs for hotplug, etc\n"
 155    "                cores= number of CPU cores on one socket\n"
 156    "                threads= number of threads on one CPU core\n"
 157    "                sockets= number of discrete sockets in the system\n",
 158        QEMU_ARCH_ALL)
 159STEXI
 160@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
 161@findex -smp
 162Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
 163CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
 164to 4.
 165For the PC target, the number of @var{cores} per socket, the number
 166of @var{threads} per cores and the total number of @var{sockets} can be
 167specified. Missing values will be computed. If any on the three values is
 168given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
 169specifies the maximum number of hotpluggable CPUs.
 170ETEXI
 171
 172DEF("numa", HAS_ARG, QEMU_OPTION_numa,
 173    "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
 174    "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
 175    "-numa dist,src=source,dst=destination,val=distance\n"
 176    "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n",
 177    QEMU_ARCH_ALL)
 178STEXI
 179@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
 180@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
 181@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
 182@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}]
 183@findex -numa
 184Define a NUMA node and assign RAM and VCPUs to it.
 185Set the NUMA distance from a source node to a destination node.
 186
 187Legacy VCPU assignment uses @samp{cpus} option where
 188@var{firstcpu} and @var{lastcpu} are CPU indexes. Each
 189@samp{cpus} option represent a contiguous range of CPU indexes
 190(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous
 191set of VCPUs can be represented by providing multiple @samp{cpus}
 192options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
 193split between them.
 194
 195For example, the following option assigns VCPUs 0, 1, 2 and 5 to
 196a NUMA node:
 197@example
 198-numa node,cpus=0-2,cpus=5
 199@end example
 200
 201@samp{cpu} option is a new alternative to @samp{cpus} option
 202which uses @samp{socket-id|core-id|thread-id} properties to assign
 203CPU objects to a @var{node} using topology layout properties of CPU.
 204The set of properties is machine specific, and depends on used
 205machine type/@samp{smp} options. It could be queried with
 206@samp{hotpluggable-cpus} monitor command.
 207@samp{node-id} property specifies @var{node} to which CPU object
 208will be assigned, it's required for @var{node} to be declared
 209with @samp{node} option before it's used with @samp{cpu} option.
 210
 211For example:
 212@example
 213-M pc \
 214-smp 1,sockets=2,maxcpus=2 \
 215-numa node,nodeid=0 -numa node,nodeid=1 \
 216-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
 217@end example
 218
 219@samp{mem} assigns a given RAM amount to a node. @samp{memdev}
 220assigns RAM from a given memory backend device to a node. If
 221@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
 222split equally between them.
 223
 224@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
 225if one node uses @samp{memdev}, all of them have to use it.
 226
 227@var{source} and @var{destination} are NUMA node IDs.
 228@var{distance} is the NUMA distance from @var{source} to @var{destination}.
 229The distance from a node to itself is always 10. If any pair of nodes is
 230given a distance, then all pairs must be given distances. Although, when
 231distances are only given in one direction for each pair of nodes, then
 232the distances in the opposite directions are assumed to be the same. If,
 233however, an asymmetrical pair of distances is given for even one node
 234pair, then all node pairs must be provided distance values for both
 235directions, even when they are symmetrical. When a node is unreachable
 236from another node, set the pair's distance to 255.
 237
 238Note that the -@option{numa} option doesn't allocate any of the
 239specified resources, it just assigns existing resources to NUMA
 240nodes. This means that one still has to use the @option{-m},
 241@option{-smp} options to allocate RAM and VCPUs respectively.
 242
 243ETEXI
 244
 245DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
 246    "-add-fd fd=fd,set=set[,opaque=opaque]\n"
 247    "                Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
 248STEXI
 249@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
 250@findex -add-fd
 251
 252Add a file descriptor to an fd set.  Valid options are:
 253
 254@table @option
 255@item fd=@var{fd}
 256This option defines the file descriptor of which a duplicate is added to fd set.
 257The file descriptor cannot be stdin, stdout, or stderr.
 258@item set=@var{set}
 259This option defines the ID of the fd set to add the file descriptor to.
 260@item opaque=@var{opaque}
 261This option defines a free-form string that can be used to describe @var{fd}.
 262@end table
 263
 264You can open an image using pre-opened file descriptors from an fd set:
 265@example
 266qemu-system-i386
 267-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
 268-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
 269-drive file=/dev/fdset/2,index=0,media=disk
 270@end example
 271ETEXI
 272
 273DEF("set", HAS_ARG, QEMU_OPTION_set,
 274    "-set group.id.arg=value\n"
 275    "                set <arg> parameter for item <id> of type <group>\n"
 276    "                i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
 277STEXI
 278@item -set @var{group}.@var{id}.@var{arg}=@var{value}
 279@findex -set
 280Set parameter @var{arg} for item @var{id} of type @var{group}
 281ETEXI
 282
 283DEF("global", HAS_ARG, QEMU_OPTION_global,
 284    "-global driver.property=value\n"
 285    "-global driver=driver,property=property,value=value\n"
 286    "                set a global default for a driver property\n",
 287    QEMU_ARCH_ALL)
 288STEXI
 289@item -global @var{driver}.@var{prop}=@var{value}
 290@itemx -global driver=@var{driver},property=@var{property},value=@var{value}
 291@findex -global
 292Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
 293
 294@example
 295qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
 296@end example
 297
 298In particular, you can use this to set driver properties for devices which are
 299created automatically by the machine model. To create a device which is not
 300created automatically and set properties on it, use -@option{device}.
 301
 302-global @var{driver}.@var{prop}=@var{value} is shorthand for -global
 303driver=@var{driver},property=@var{prop},value=@var{value}.  The
 304longhand syntax works even when @var{driver} contains a dot.
 305ETEXI
 306
 307DEF("boot", HAS_ARG, QEMU_OPTION_boot,
 308    "-boot [order=drives][,once=drives][,menu=on|off]\n"
 309    "      [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
 310    "                'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
 311    "                'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
 312    "                'sp_time': the period that splash picture last if menu=on, unit is ms\n"
 313    "                'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
 314    QEMU_ARCH_ALL)
 315STEXI
 316@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]
 317@findex -boot
 318Specify boot order @var{drives} as a string of drive letters. Valid
 319drive letters depend on the target architecture. The x86 PC uses: a, b
 320(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
 321from network adapter 1-4), hard disk boot is the default. To apply a
 322particular boot order only on the first startup, specify it via
 323@option{once}. Note that the @option{order} or @option{once} parameter
 324should not be used together with the @option{bootindex} property of
 325devices, since the firmware implementations normally do not support both
 326at the same time.
 327
 328Interactive boot menus/prompts can be enabled via @option{menu=on} as far
 329as firmware/BIOS supports them. The default is non-interactive boot.
 330
 331A splash picture could be passed to bios, enabling user to show it as logo,
 332when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
 333supports them. Currently Seabios for X86 system support it.
 334limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
 335format(true color). The resolution should be supported by the SVGA mode, so
 336the recommended is 320x240, 640x480, 800x640.
 337
 338A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
 339when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
 340reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
 341system support it.
 342
 343Do strict boot via @option{strict=on} as far as firmware/BIOS
 344supports it. This only effects when boot priority is changed by
 345bootindex options. The default is non-strict boot.
 346
 347@example
 348# try to boot from network first, then from hard disk
 349qemu-system-i386 -boot order=nc
 350# boot from CD-ROM first, switch back to default order after reboot
 351qemu-system-i386 -boot once=d
 352# boot with a splash picture for 5 seconds.
 353qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
 354@end example
 355
 356Note: The legacy format '-boot @var{drives}' is still supported but its
 357use is discouraged as it may be removed from future versions.
 358ETEXI
 359
 360DEF("m", HAS_ARG, QEMU_OPTION_m,
 361    "-m [size=]megs[,slots=n,maxmem=size]\n"
 362    "                configure guest RAM\n"
 363    "                size: initial amount of guest memory\n"
 364    "                slots: number of hotplug slots (default: none)\n"
 365    "                maxmem: maximum amount of guest memory (default: none)\n"
 366    "NOTE: Some architectures might enforce a specific granularity\n",
 367    QEMU_ARCH_ALL)
 368STEXI
 369@item -m [size=]@var{megs}[,slots=n,maxmem=size]
 370@findex -m
 371Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
 372Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
 373megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
 374could be used to set amount of hotpluggable memory slots and maximum amount of
 375memory. Note that @var{maxmem} must be aligned to the page size.
 376
 377For example, the following command-line sets the guest startup RAM size to
 3781GB, creates 3 slots to hotplug additional memory and sets the maximum
 379memory the guest can reach to 4GB:
 380
 381@example
 382qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
 383@end example
 384
 385If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
 386be enabled and the guest startup RAM will never increase.
 387ETEXI
 388
 389DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
 390    "-mem-path FILE  provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
 391STEXI
 392@item -mem-path @var{path}
 393@findex -mem-path
 394Allocate guest RAM from a temporarily created file in @var{path}.
 395ETEXI
 396
 397DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
 398    "-mem-prealloc   preallocate guest memory (use with -mem-path)\n",
 399    QEMU_ARCH_ALL)
 400STEXI
 401@item -mem-prealloc
 402@findex -mem-prealloc
 403Preallocate memory when using -mem-path.
 404ETEXI
 405
 406DEF("k", HAS_ARG, QEMU_OPTION_k,
 407    "-k language     use keyboard layout (for example 'fr' for French)\n",
 408    QEMU_ARCH_ALL)
 409STEXI
 410@item -k @var{language}
 411@findex -k
 412Use keyboard layout @var{language} (for example @code{fr} for
 413French). This option is only needed where it is not easy to get raw PC
 414keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
 415display). You don't normally need to use it on PC/Linux or PC/Windows
 416hosts.
 417
 418The available layouts are:
 419@example
 420ar  de-ch  es  fo     fr-ca  hu  ja  mk     no  pt-br  sv
 421da  en-gb  et  fr     fr-ch  is  lt  nl     pl  ru     th
 422de  en-us  fi  fr-be  hr     it  lv  nl-be  pt  sl     tr
 423@end example
 424
 425The default is @code{en-us}.
 426ETEXI
 427
 428
 429DEF("audio-help", 0, QEMU_OPTION_audio_help,
 430    "-audio-help     print list of audio drivers and their options\n",
 431    QEMU_ARCH_ALL)
 432STEXI
 433@item -audio-help
 434@findex -audio-help
 435Will show the audio subsystem help: list of drivers, tunable
 436parameters.
 437ETEXI
 438
 439DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
 440    "-soundhw c1,... enable audio support\n"
 441    "                and only specified sound cards (comma separated list)\n"
 442    "                use '-soundhw help' to get the list of supported cards\n"
 443    "                use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
 444STEXI
 445@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
 446@findex -soundhw
 447Enable audio and selected sound hardware. Use 'help' to print all
 448available sound hardware.
 449
 450@example
 451qemu-system-i386 -soundhw sb16,adlib disk.img
 452qemu-system-i386 -soundhw es1370 disk.img
 453qemu-system-i386 -soundhw ac97 disk.img
 454qemu-system-i386 -soundhw hda disk.img
 455qemu-system-i386 -soundhw all disk.img
 456qemu-system-i386 -soundhw help
 457@end example
 458
 459Note that Linux's i810_audio OSS kernel (for AC97) module might
 460require manually specifying clocking.
 461
 462@example
 463modprobe i810_audio clocking=48000
 464@end example
 465ETEXI
 466
 467DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
 468    "-balloon virtio[,addr=str]\n"
 469    "                enable virtio balloon device (deprecated)\n", QEMU_ARCH_ALL)
 470STEXI
 471@item -balloon virtio[,addr=@var{addr}]
 472@findex -balloon
 473Enable virtio balloon device, optionally with PCI address @var{addr}. This
 474option is deprecated, use @option{--device virtio-balloon} instead.
 475ETEXI
 476
 477DEF("device", HAS_ARG, QEMU_OPTION_device,
 478    "-device driver[,prop[=value][,...]]\n"
 479    "                add device (based on driver)\n"
 480    "                prop=value,... sets driver properties\n"
 481    "                use '-device help' to print all possible drivers\n"
 482    "                use '-device driver,help' to print all possible properties\n",
 483    QEMU_ARCH_ALL)
 484STEXI
 485@item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
 486@findex -device
 487Add device @var{driver}.  @var{prop}=@var{value} sets driver
 488properties.  Valid properties depend on the driver.  To get help on
 489possible drivers and properties, use @code{-device help} and
 490@code{-device @var{driver},help}.
 491
 492Some drivers are:
 493@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
 494
 495Add an IPMI BMC.  This is a simulation of a hardware management
 496interface processor that normally sits on a system.  It provides
 497a watchdog and the ability to reset and power control the system.
 498You need to connect this to an IPMI interface to make it useful
 499
 500The IPMI slave address to use for the BMC.  The default is 0x20.
 501This address is the BMC's address on the I2C network of management
 502controllers.  If you don't know what this means, it is safe to ignore
 503it.
 504
 505@table @option
 506@item bmc=@var{id}
 507The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
 508@item slave_addr=@var{val}
 509Define slave address to use for the BMC.  The default is 0x20.
 510@item sdrfile=@var{file}
 511file containing raw Sensor Data Records (SDR) data. The default is none.
 512@item fruareasize=@var{val}
 513size of a Field Replaceable Unit (FRU) area.  The default is 1024.
 514@item frudatafile=@var{file}
 515file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
 516@end table
 517
 518@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
 519
 520Add a connection to an external IPMI BMC simulator.  Instead of
 521locally emulating the BMC like the above item, instead connect
 522to an external entity that provides the IPMI services.
 523
 524A connection is made to an external BMC simulator.  If you do this, it
 525is strongly recommended that you use the "reconnect=" chardev option
 526to reconnect to the simulator if the connection is lost.  Note that if
 527this is not used carefully, it can be a security issue, as the
 528interface has the ability to send resets, NMIs, and power off the VM.
 529It's best if QEMU makes a connection to an external simulator running
 530on a secure port on localhost, so neither the simulator nor QEMU is
 531exposed to any outside network.
 532
 533See the "lanserv/README.vm" file in the OpenIPMI library for more
 534details on the external interface.
 535
 536@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
 537
 538Add a KCS IPMI interafce on the ISA bus.  This also adds a
 539corresponding ACPI and SMBIOS entries, if appropriate.
 540
 541@table @option
 542@item bmc=@var{id}
 543The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
 544@item ioport=@var{val}
 545Define the I/O address of the interface.  The default is 0xca0 for KCS.
 546@item irq=@var{val}
 547Define the interrupt to use.  The default is 5.  To disable interrupts,
 548set this to 0.
 549@end table
 550
 551@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
 552
 553Like the KCS interface, but defines a BT interface.  The default port is
 5540xe4 and the default interrupt is 5.
 555
 556ETEXI
 557
 558DEF("name", HAS_ARG, QEMU_OPTION_name,
 559    "-name string1[,process=string2][,debug-threads=on|off]\n"
 560    "                set the name of the guest\n"
 561    "                string1 sets the window title and string2 the process name (on Linux)\n"
 562    "                When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
 563    "                NOTE: The thread names are for debugging and not a stable API.\n",
 564    QEMU_ARCH_ALL)
 565STEXI
 566@item -name @var{name}
 567@findex -name
 568Sets the @var{name} of the guest.
 569This name will be displayed in the SDL window caption.
 570The @var{name} will also be used for the VNC server.
 571Also optionally set the top visible process name in Linux.
 572Naming of individual threads can also be enabled on Linux to aid debugging.
 573ETEXI
 574
 575DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
 576    "-uuid %08x-%04x-%04x-%04x-%012x\n"
 577    "                specify machine UUID\n", QEMU_ARCH_ALL)
 578STEXI
 579@item -uuid @var{uuid}
 580@findex -uuid
 581Set system UUID.
 582ETEXI
 583
 584STEXI
 585@end table
 586ETEXI
 587DEFHEADING()
 588
 589DEFHEADING(Block device options:)
 590STEXI
 591@table @option
 592ETEXI
 593
 594DEF("fda", HAS_ARG, QEMU_OPTION_fda,
 595    "-fda/-fdb file  use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
 596DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
 597STEXI
 598@item -fda @var{file}
 599@itemx -fdb @var{file}
 600@findex -fda
 601@findex -fdb
 602Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
 603ETEXI
 604
 605DEF("hda", HAS_ARG, QEMU_OPTION_hda,
 606    "-hda/-hdb file  use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
 607DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
 608DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
 609    "-hdc/-hdd file  use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
 610DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
 611STEXI
 612@item -hda @var{file}
 613@itemx -hdb @var{file}
 614@itemx -hdc @var{file}
 615@itemx -hdd @var{file}
 616@findex -hda
 617@findex -hdb
 618@findex -hdc
 619@findex -hdd
 620Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
 621ETEXI
 622
 623DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
 624    "-cdrom file     use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
 625    QEMU_ARCH_ALL)
 626STEXI
 627@item -cdrom @var{file}
 628@findex -cdrom
 629Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
 630@option{-cdrom} at the same time). You can use the host CD-ROM by
 631using @file{/dev/cdrom} as filename (@pxref{host_drives}).
 632ETEXI
 633
 634DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
 635    "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
 636    "          [,cache.direct=on|off][,cache.no-flush=on|off]\n"
 637    "          [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
 638    "          [,driver specific parameters...]\n"
 639    "                configure a block backend\n", QEMU_ARCH_ALL)
 640STEXI
 641@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
 642@findex -blockdev
 643
 644Define a new block driver node. Some of the options apply to all block drivers,
 645other options are only accepted for a specific block driver. See below for a
 646list of generic options and options for the most common block drivers.
 647
 648Options that expect a reference to another node (e.g. @code{file}) can be
 649given in two ways. Either you specify the node name of an already existing node
 650(file=@var{node-name}), or you define a new node inline, adding options
 651for the referenced node after a dot (file.filename=@var{path},file.aio=native).
 652
 653A block driver node created with @option{-blockdev} can be used for a guest
 654device by specifying its node name for the @code{drive} property in a
 655@option{-device} argument that defines a block device.
 656
 657@table @option
 658@item Valid options for any block driver node:
 659
 660@table @code
 661@item driver
 662Specifies the block driver to use for the given node.
 663@item node-name
 664This defines the name of the block driver node by which it will be referenced
 665later. The name must be unique, i.e. it must not match the name of a different
 666block driver node, or (if you use @option{-drive} as well) the ID of a drive.
 667
 668If no node name is specified, it is automatically generated. The generated node
 669name is not intended to be predictable and changes between QEMU invocations.
 670For the top level, an explicit node name must be specified.
 671@item read-only
 672Open the node read-only. Guest write attempts will fail.
 673@item cache.direct
 674The host page cache can be avoided with @option{cache.direct=on}. This will
 675attempt to do disk IO directly to the guest's memory. QEMU may still perform an
 676internal copy of the data.
 677@item cache.no-flush
 678In case you don't care about data integrity over host failures, you can use
 679@option{cache.no-flush=on}. This option tells QEMU that it never needs to write
 680any data to the disk but can instead keep things in cache. If anything goes
 681wrong, like your host losing power, the disk storage getting disconnected
 682accidentally, etc. your image will most probably be rendered unusable.
 683@item discard=@var{discard}
 684@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
 685whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
 686ignored or passed to the filesystem. Some machine types may not support
 687discard requests.
 688@item detect-zeroes=@var{detect-zeroes}
 689@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
 690conversion of plain zero writes by the OS to driver specific optimized
 691zero write commands. You may even choose "unmap" if @var{discard} is set
 692to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
 693@end table
 694
 695@item Driver-specific options for @code{file}
 696
 697This is the protocol-level block driver for accessing regular files.
 698
 699@table @code
 700@item filename
 701The path to the image file in the local filesystem
 702@item aio
 703Specifies the AIO backend (threads/native, default: threads)
 704@item locking
 705Specifies whether the image file is protected with Linux OFD / POSIX locks. The
 706default is to use the Linux Open File Descriptor API if available, otherwise no
 707lock is applied.  (auto/on/off, default: auto)
 708@end table
 709Example:
 710@example
 711-blockdev driver=file,node-name=disk,filename=disk.img
 712@end example
 713
 714@item Driver-specific options for @code{raw}
 715
 716This is the image format block driver for raw images. It is usually
 717stacked on top of a protocol level block driver such as @code{file}.
 718
 719@table @code
 720@item file
 721Reference to or definition of the data source block driver node
 722(e.g. a @code{file} driver node)
 723@end table
 724Example 1:
 725@example
 726-blockdev driver=file,node-name=disk_file,filename=disk.img
 727-blockdev driver=raw,node-name=disk,file=disk_file
 728@end example
 729Example 2:
 730@example
 731-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
 732@end example
 733
 734@item Driver-specific options for @code{qcow2}
 735
 736This is the image format block driver for qcow2 images. It is usually
 737stacked on top of a protocol level block driver such as @code{file}.
 738
 739@table @code
 740@item file
 741Reference to or definition of the data source block driver node
 742(e.g. a @code{file} driver node)
 743
 744@item backing
 745Reference to or definition of the backing file block device (default is taken
 746from the image file). It is allowed to pass @code{null} here in order to disable
 747the default backing file.
 748
 749@item lazy-refcounts
 750Whether to enable the lazy refcounts feature (on/off; default is taken from the
 751image file)
 752
 753@item cache-size
 754The maximum total size of the L2 table and refcount block caches in bytes
 755(default: 1048576 bytes or 8 clusters, whichever is larger)
 756
 757@item l2-cache-size
 758The maximum size of the L2 table cache in bytes
 759(default: 4/5 of the total cache size)
 760
 761@item refcount-cache-size
 762The maximum size of the refcount block cache in bytes
 763(default: 1/5 of the total cache size)
 764
 765@item cache-clean-interval
 766Clean unused entries in the L2 and refcount caches. The interval is in seconds.
 767The default value is 0 and it disables this feature.
 768
 769@item pass-discard-request
 770Whether discard requests to the qcow2 device should be forwarded to the data
 771source (on/off; default: on if discard=unmap is specified, off otherwise)
 772
 773@item pass-discard-snapshot
 774Whether discard requests for the data source should be issued when a snapshot
 775operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
 776default: on)
 777
 778@item pass-discard-other
 779Whether discard requests for the data source should be issued on other
 780occasions where a cluster gets freed (on/off; default: off)
 781
 782@item overlap-check
 783Which overlap checks to perform for writes to the image
 784(none/constant/cached/all; default: cached). For details or finer
 785granularity control refer to the QAPI documentation of @code{blockdev-add}.
 786@end table
 787
 788Example 1:
 789@example
 790-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
 791-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
 792@end example
 793Example 2:
 794@example
 795-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
 796@end example
 797
 798@item Driver-specific options for other drivers
 799Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
 800
 801@end table
 802
 803ETEXI
 804
 805DEF("drive", HAS_ARG, QEMU_OPTION_drive,
 806    "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
 807    "       [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
 808    "       [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
 809    "       [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
 810    "       [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
 811    "       [,readonly=on|off][,copy-on-read=on|off]\n"
 812    "       [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
 813    "       [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
 814    "       [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
 815    "       [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
 816    "       [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
 817    "       [[,iops_size=is]]\n"
 818    "       [[,group=g]]\n"
 819    "                use 'file' as a drive image\n", QEMU_ARCH_ALL)
 820STEXI
 821@item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
 822@findex -drive
 823
 824Define a new drive. This includes creating a block driver node (the backend) as
 825well as a guest device, and is mostly a shortcut for defining the corresponding
 826@option{-blockdev} and @option{-device} options.
 827
 828@option{-drive} accepts all options that are accepted by @option{-blockdev}. In
 829addition, it knows the following options:
 830
 831@table @option
 832@item file=@var{file}
 833This option defines which disk image (@pxref{disk_images}) to use with
 834this drive. If the filename contains comma, you must double it
 835(for instance, "file=my,,file" to use file "my,file").
 836
 837Special files such as iSCSI devices can be specified using protocol
 838specific URLs. See the section for "Device URL Syntax" for more information.
 839@item if=@var{interface}
 840This option defines on which type on interface the drive is connected.
 841Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
 842@item bus=@var{bus},unit=@var{unit}
 843These options define where is connected the drive by defining the bus number and
 844the unit id.
 845@item index=@var{index}
 846This option defines where is connected the drive by using an index in the list
 847of available connectors of a given interface type.
 848@item media=@var{media}
 849This option defines the type of the media: disk or cdrom.
 850@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
 851Force disk physical geometry and the optional BIOS translation (trans=none or
 852lba). These parameters are deprecated, use the corresponding parameters
 853of @code{-device} instead.
 854@item snapshot=@var{snapshot}
 855@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
 856(see @option{-snapshot}).
 857@item cache=@var{cache}
 858@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
 859and controls how the host cache is used to access block data. This is a
 860shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
 861options (as in @option{-blockdev}), and additionally @option{cache.writeback},
 862which provides a default for the @option{write-cache} option of block guest
 863devices (as in @option{-device}). The modes correspond to the following
 864settings:
 865
 866@c Our texi2pod.pl script doesn't support @multitable, so fall back to using
 867@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
 868@c and the HTML output.
 869@example
 870@             │ cache.writeback   cache.direct   cache.no-flush
 871─────────────┼─────────────────────────────────────────────────
 872writeback    │ on                off            off
 873none         │ on                on             off
 874writethrough │ off               off            off
 875directsync   │ off               on             off
 876unsafe       │ on                off            on
 877@end example
 878
 879The default mode is @option{cache=writeback}.
 880
 881@item aio=@var{aio}
 882@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
 883@item format=@var{format}
 884Specify which disk @var{format} will be used rather than detecting
 885the format.  Can be used to specify format=raw to avoid interpreting
 886an untrusted format header.
 887@item serial=@var{serial}
 888This option specifies the serial number to assign to the device. This
 889parameter is deprecated, use the corresponding parameter of @code{-device}
 890instead.
 891@item addr=@var{addr}
 892Specify the controller's PCI address (if=virtio only). This parameter is
 893deprecated, use the corresponding parameter of @code{-device} instead.
 894@item werror=@var{action},rerror=@var{action}
 895Specify which @var{action} to take on write and read errors. Valid actions are:
 896"ignore" (ignore the error and try to continue), "stop" (pause QEMU),
 897"report" (report the error to the guest), "enospc" (pause QEMU only if the
 898host disk is full; report the error to the guest otherwise).
 899The default setting is @option{werror=enospc} and @option{rerror=report}.
 900@item copy-on-read=@var{copy-on-read}
 901@var{copy-on-read} is "on" or "off" and enables whether to copy read backing
 902file sectors into the image file.
 903@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
 904Specify bandwidth throttling limits in bytes per second, either for all request
 905types or for reads or writes only.  Small values can lead to timeouts or hangs
 906inside the guest.  A safe minimum for disks is 2 MB/s.
 907@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
 908Specify bursts in bytes per second, either for all request types or for reads
 909or writes only.  Bursts allow the guest I/O to spike above the limit
 910temporarily.
 911@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
 912Specify request rate limits in requests per second, either for all request
 913types or for reads or writes only.
 914@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
 915Specify bursts in requests per second, either for all request types or for reads
 916or writes only.  Bursts allow the guest I/O to spike above the limit
 917temporarily.
 918@item iops_size=@var{is}
 919Let every @var{is} bytes of a request count as a new request for iops
 920throttling purposes.  Use this option to prevent guests from circumventing iops
 921limits by sending fewer but larger requests.
 922@item group=@var{g}
 923Join a throttling quota group with given name @var{g}.  All drives that are
 924members of the same group are accounted for together.  Use this option to
 925prevent guests from circumventing throttling limits by using many small disks
 926instead of a single larger disk.
 927@end table
 928
 929By default, the @option{cache.writeback=on} mode is used. It will report data
 930writes as completed as soon as the data is present in the host page cache.
 931This is safe as long as your guest OS makes sure to correctly flush disk caches
 932where needed. If your guest OS does not handle volatile disk write caches
 933correctly and your host crashes or loses power, then the guest may experience
 934data corruption.
 935
 936For such guests, you should consider using @option{cache.writeback=off}. This
 937means that the host page cache will be used to read and write data, but write
 938notification will be sent to the guest only after QEMU has made sure to flush
 939each write to the disk. Be aware that this has a major impact on performance.
 940
 941When using the @option{-snapshot} option, unsafe caching is always used.
 942
 943Copy-on-read avoids accessing the same backing file sectors repeatedly and is
 944useful when the backing file is over a slow network.  By default copy-on-read
 945is off.
 946
 947Instead of @option{-cdrom} you can use:
 948@example
 949qemu-system-i386 -drive file=file,index=2,media=cdrom
 950@end example
 951
 952Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
 953use:
 954@example
 955qemu-system-i386 -drive file=file,index=0,media=disk
 956qemu-system-i386 -drive file=file,index=1,media=disk
 957qemu-system-i386 -drive file=file,index=2,media=disk
 958qemu-system-i386 -drive file=file,index=3,media=disk
 959@end example
 960
 961You can open an image using pre-opened file descriptors from an fd set:
 962@example
 963qemu-system-i386
 964-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
 965-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
 966-drive file=/dev/fdset/2,index=0,media=disk
 967@end example
 968
 969You can connect a CDROM to the slave of ide0:
 970@example
 971qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
 972@end example
 973
 974If you don't specify the "file=" argument, you define an empty drive:
 975@example
 976qemu-system-i386 -drive if=ide,index=1,media=cdrom
 977@end example
 978
 979Instead of @option{-fda}, @option{-fdb}, you can use:
 980@example
 981qemu-system-i386 -drive file=file,index=0,if=floppy
 982qemu-system-i386 -drive file=file,index=1,if=floppy
 983@end example
 984
 985By default, @var{interface} is "ide" and @var{index} is automatically
 986incremented:
 987@example
 988qemu-system-i386 -drive file=a -drive file=b"
 989@end example
 990is interpreted like:
 991@example
 992qemu-system-i386 -hda a -hdb b
 993@end example
 994ETEXI
 995
 996DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
 997    "-mtdblock file  use 'file' as on-board Flash memory image\n",
 998    QEMU_ARCH_ALL)
 999STEXI
1000@item -mtdblock @var{file}
1001@findex -mtdblock
1002Use @var{file} as on-board Flash memory image.
1003ETEXI
1004
1005DEF("sd", HAS_ARG, QEMU_OPTION_sd,
1006    "-sd file        use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
1007STEXI
1008@item -sd @var{file}
1009@findex -sd
1010Use @var{file} as SecureDigital card image.
1011ETEXI
1012
1013DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
1014    "-pflash file    use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
1015STEXI
1016@item -pflash @var{file}
1017@findex -pflash
1018Use @var{file} as a parallel flash image.
1019ETEXI
1020
1021DEF("snapshot", 0, QEMU_OPTION_snapshot,
1022    "-snapshot       write to temporary files instead of disk image files\n",
1023    QEMU_ARCH_ALL)
1024STEXI
1025@item -snapshot
1026@findex -snapshot
1027Write to temporary files instead of disk image files. In this case,
1028the raw disk image you use is not written back. You can however force
1029the write back by pressing @key{C-a s} (@pxref{disk_images}).
1030ETEXI
1031
1032DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1033    "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1034    " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1035    " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1036    " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1037    " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1038    " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1039    " [[,throttling.iops-size=is]]\n",
1040    QEMU_ARCH_ALL)
1041
1042STEXI
1043
1044@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}]
1045@findex -fsdev
1046Define a new file system device. Valid options are:
1047@table @option
1048@item @var{fsdriver}
1049This option specifies the fs driver backend to use.
1050Currently "local", "handle" and "proxy" file system drivers are supported.
1051@item id=@var{id}
1052Specifies identifier for this device
1053@item path=@var{path}
1054Specifies the export path for the file system device. Files under
1055this path will be available to the 9p client on the guest.
1056@item security_model=@var{security_model}
1057Specifies the security model to be used for this export path.
1058Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1059In "passthrough" security model, files are stored using the same
1060credentials as they are created on the guest. This requires QEMU
1061to run as root. In "mapped-xattr" security model, some of the file
1062attributes like uid, gid, mode bits and link target are stored as
1063file attributes. For "mapped-file" these attributes are stored in the
1064hidden .virtfs_metadata directory. Directories exported by this security model cannot
1065interact with other unix tools. "none" security model is same as
1066passthrough except the sever won't report failures if it fails to
1067set file attributes like ownership. Security model is mandatory
1068only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1069security model as a parameter.
1070@item writeout=@var{writeout}
1071This is an optional argument. The only supported value is "immediate".
1072This means that host page cache will be used to read and write data but
1073write notification will be sent to the guest only when the data has been
1074reported as written by the storage subsystem.
1075@item readonly
1076Enables exporting 9p share as a readonly mount for guests. By default
1077read-write access is given.
1078@item socket=@var{socket}
1079Enables proxy filesystem driver to use passed socket file for communicating
1080with virtfs-proxy-helper
1081@item sock_fd=@var{sock_fd}
1082Enables proxy filesystem driver to use passed socket descriptor for
1083communicating with virtfs-proxy-helper. Usually a helper like libvirt
1084will create socketpair and pass one of the fds as sock_fd
1085@item fmode=@var{fmode}
1086Specifies the default mode for newly created files on the host. Works only
1087with security models "mapped-xattr" and "mapped-file".
1088@item dmode=@var{dmode}
1089Specifies the default mode for newly created directories on the host. Works
1090only with security models "mapped-xattr" and "mapped-file".
1091@end table
1092
1093-fsdev option is used along with -device driver "virtio-9p-pci".
1094@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1095Options for virtio-9p-pci driver are:
1096@table @option
1097@item fsdev=@var{id}
1098Specifies the id value specified along with -fsdev option
1099@item mount_tag=@var{mount_tag}
1100Specifies the tag name to be used by the guest to mount this export point
1101@end table
1102
1103ETEXI
1104
1105DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1106    "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1107    "        [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1108    QEMU_ARCH_ALL)
1109
1110STEXI
1111
1112@item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}]
1113@findex -virtfs
1114
1115The general form of a Virtual File system pass-through options are:
1116@table @option
1117@item @var{fsdriver}
1118This option specifies the fs driver backend to use.
1119Currently "local", "handle" and "proxy" file system drivers are supported.
1120@item id=@var{id}
1121Specifies identifier for this device
1122@item path=@var{path}
1123Specifies the export path for the file system device. Files under
1124this path will be available to the 9p client on the guest.
1125@item security_model=@var{security_model}
1126Specifies the security model to be used for this export path.
1127Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1128In "passthrough" security model, files are stored using the same
1129credentials as they are created on the guest. This requires QEMU
1130to run as root. In "mapped-xattr" security model, some of the file
1131attributes like uid, gid, mode bits and link target are stored as
1132file attributes. For "mapped-file" these attributes are stored in the
1133hidden .virtfs_metadata directory. Directories exported by this security model cannot
1134interact with other unix tools. "none" security model is same as
1135passthrough except the sever won't report failures if it fails to
1136set file attributes like ownership. Security model is mandatory only
1137for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1138model as a parameter.
1139@item writeout=@var{writeout}
1140This is an optional argument. The only supported value is "immediate".
1141This means that host page cache will be used to read and write data but
1142write notification will be sent to the guest only when the data has been
1143reported as written by the storage subsystem.
1144@item readonly
1145Enables exporting 9p share as a readonly mount for guests. By default
1146read-write access is given.
1147@item socket=@var{socket}
1148Enables proxy filesystem driver to use passed socket file for
1149communicating with virtfs-proxy-helper. Usually a helper like libvirt
1150will create socketpair and pass one of the fds as sock_fd
1151@item sock_fd
1152Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1153descriptor for interfacing with virtfs-proxy-helper
1154@item fmode=@var{fmode}
1155Specifies the default mode for newly created files on the host. Works only
1156with security models "mapped-xattr" and "mapped-file".
1157@item dmode=@var{dmode}
1158Specifies the default mode for newly created directories on the host. Works
1159only with security models "mapped-xattr" and "mapped-file".
1160@end table
1161ETEXI
1162
1163DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1164    "-virtfs_synth Create synthetic file system image\n",
1165    QEMU_ARCH_ALL)
1166STEXI
1167@item -virtfs_synth
1168@findex -virtfs_synth
1169Create synthetic file system image
1170ETEXI
1171
1172DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1173    "-iscsi [user=user][,password=password]\n"
1174    "       [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1175    "       [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1176    "       [,timeout=timeout]\n"
1177    "                iSCSI session parameters\n", QEMU_ARCH_ALL)
1178
1179STEXI
1180@item -iscsi
1181@findex -iscsi
1182Configure iSCSI session parameters.
1183ETEXI
1184
1185STEXI
1186@end table
1187ETEXI
1188DEFHEADING()
1189
1190DEFHEADING(USB options:)
1191STEXI
1192@table @option
1193ETEXI
1194
1195DEF("usb", 0, QEMU_OPTION_usb,
1196    "-usb            enable the USB driver (if it is not used by default yet)\n",
1197    QEMU_ARCH_ALL)
1198STEXI
1199@item -usb
1200@findex -usb
1201Enable the USB driver (if it is not used by default yet).
1202ETEXI
1203
1204DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1205    "-usbdevice name add the host or guest USB device 'name'\n",
1206    QEMU_ARCH_ALL)
1207STEXI
1208
1209@item -usbdevice @var{devname}
1210@findex -usbdevice
1211Add the USB device @var{devname}. Note that this option is deprecated,
1212please use @code{-device usb-...} instead. @xref{usb_devices}.
1213
1214@table @option
1215
1216@item mouse
1217Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1218
1219@item tablet
1220Pointer device that uses absolute coordinates (like a touchscreen). This
1221means QEMU is able to report the mouse position without having to grab the
1222mouse. Also overrides the PS/2 mouse emulation when activated.
1223
1224@item braille
1225Braille device.  This will use BrlAPI to display the braille output on a real
1226or fake device.
1227
1228@end table
1229ETEXI
1230
1231STEXI
1232@end table
1233ETEXI
1234DEFHEADING()
1235
1236DEFHEADING(Display options:)
1237STEXI
1238@table @option
1239ETEXI
1240
1241DEF("display", HAS_ARG, QEMU_OPTION_display,
1242    "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1243    "            [,window_close=on|off][,gl=on|off]\n"
1244    "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1245    "-display vnc=<display>[,<optargs>]\n"
1246    "-display curses\n"
1247    "-display none"
1248    "                select display type\n"
1249    "The default display is equivalent to\n"
1250#if defined(CONFIG_GTK)
1251            "\t\"-display gtk\"\n"
1252#elif defined(CONFIG_SDL)
1253            "\t\"-display sdl\"\n"
1254#elif defined(CONFIG_COCOA)
1255            "\t\"-display cocoa\"\n"
1256#elif defined(CONFIG_VNC)
1257            "\t\"-vnc localhost:0,to=99,id=default\"\n"
1258#else
1259            "\t\"-display none\"\n"
1260#endif
1261    , QEMU_ARCH_ALL)
1262STEXI
1263@item -display @var{type}
1264@findex -display
1265Select type of display to use. This option is a replacement for the
1266old style -sdl/-curses/... options. Valid values for @var{type} are
1267@table @option
1268@item sdl
1269Display video output via SDL (usually in a separate graphics
1270window; see the SDL documentation for other possibilities).
1271@item curses
1272Display video output via curses. For graphics device models which
1273support a text mode, QEMU can display this output using a
1274curses/ncurses interface. Nothing is displayed when the graphics
1275device is in graphical mode or if the graphics device does not support
1276a text mode. Generally only the VGA device models support text mode.
1277@item none
1278Do not display video output. The guest will still see an emulated
1279graphics card, but its output will not be displayed to the QEMU
1280user. This option differs from the -nographic option in that it
1281only affects what is done with video output; -nographic also changes
1282the destination of the serial and parallel port data.
1283@item gtk
1284Display video output in a GTK window. This interface provides drop-down
1285menus and other UI elements to configure and control the VM during
1286runtime.
1287@item vnc
1288Start a VNC server on display <arg>
1289@end table
1290ETEXI
1291
1292DEF("nographic", 0, QEMU_OPTION_nographic,
1293    "-nographic      disable graphical output and redirect serial I/Os to console\n",
1294    QEMU_ARCH_ALL)
1295STEXI
1296@item -nographic
1297@findex -nographic
1298Normally, if QEMU is compiled with graphical window support, it displays
1299output such as guest graphics, guest console, and the QEMU monitor in a
1300window. With this option, you can totally disable graphical output so
1301that QEMU is a simple command line application. The emulated serial port
1302is redirected on the console and muxed with the monitor (unless
1303redirected elsewhere explicitly). Therefore, you can still use QEMU to
1304debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1305switching between the console and monitor.
1306ETEXI
1307
1308DEF("curses", 0, QEMU_OPTION_curses,
1309    "-curses         shorthand for -display curses\n",
1310    QEMU_ARCH_ALL)
1311STEXI
1312@item -curses
1313@findex -curses
1314Normally, if QEMU is compiled with graphical window support, it displays
1315output such as guest graphics, guest console, and the QEMU monitor in a
1316window. With this option, QEMU can display the VGA output when in text
1317mode using a curses/ncurses interface. Nothing is displayed in graphical
1318mode.
1319ETEXI
1320
1321DEF("no-frame", 0, QEMU_OPTION_no_frame,
1322    "-no-frame       open SDL window without a frame and window decorations\n",
1323    QEMU_ARCH_ALL)
1324STEXI
1325@item -no-frame
1326@findex -no-frame
1327Do not use decorations for SDL windows and start them using the whole
1328available screen space. This makes the using QEMU in a dedicated desktop
1329workspace more convenient.
1330ETEXI
1331
1332DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1333    "-alt-grab       use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1334    QEMU_ARCH_ALL)
1335STEXI
1336@item -alt-grab
1337@findex -alt-grab
1338Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1339affects the special keys (for fullscreen, monitor-mode switching, etc).
1340ETEXI
1341
1342DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1343    "-ctrl-grab      use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1344    QEMU_ARCH_ALL)
1345STEXI
1346@item -ctrl-grab
1347@findex -ctrl-grab
1348Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1349affects the special keys (for fullscreen, monitor-mode switching, etc).
1350ETEXI
1351
1352DEF("no-quit", 0, QEMU_OPTION_no_quit,
1353    "-no-quit        disable SDL window close capability\n", QEMU_ARCH_ALL)
1354STEXI
1355@item -no-quit
1356@findex -no-quit
1357Disable SDL window close capability.
1358ETEXI
1359
1360DEF("sdl", 0, QEMU_OPTION_sdl,
1361    "-sdl            shorthand for -display sdl\n", QEMU_ARCH_ALL)
1362STEXI
1363@item -sdl
1364@findex -sdl
1365Enable SDL.
1366ETEXI
1367
1368DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1369    "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1370    "       [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1371    "       [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1372    "       [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1373    "       [,tls-ciphers=<list>]\n"
1374    "       [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1375    "       [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1376    "       [,sasl][,password=<secret>][,disable-ticketing]\n"
1377    "       [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1378    "       [,jpeg-wan-compression=[auto|never|always]]\n"
1379    "       [,zlib-glz-wan-compression=[auto|never|always]]\n"
1380    "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1381    "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1382    "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1383    "       [,gl=[on|off]][,rendernode=<file>]\n"
1384    "   enable spice\n"
1385    "   at least one of {port, tls-port} is mandatory\n",
1386    QEMU_ARCH_ALL)
1387STEXI
1388@item -spice @var{option}[,@var{option}[,...]]
1389@findex -spice
1390Enable the spice remote desktop protocol. Valid options are
1391
1392@table @option
1393
1394@item port=<nr>
1395Set the TCP port spice is listening on for plaintext channels.
1396
1397@item addr=<addr>
1398Set the IP address spice is listening on.  Default is any address.
1399
1400@item ipv4
1401@itemx ipv6
1402@itemx unix
1403Force using the specified IP version.
1404
1405@item password=<secret>
1406Set the password you need to authenticate.
1407
1408@item sasl
1409Require that the client use SASL to authenticate with the spice.
1410The exact choice of authentication method used is controlled from the
1411system / user's SASL configuration file for the 'qemu' service. This
1412is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1413unprivileged user, an environment variable SASL_CONF_PATH can be used
1414to make it search alternate locations for the service config.
1415While some SASL auth methods can also provide data encryption (eg GSSAPI),
1416it is recommended that SASL always be combined with the 'tls' and
1417'x509' settings to enable use of SSL and server certificates. This
1418ensures a data encryption preventing compromise of authentication
1419credentials.
1420
1421@item disable-ticketing
1422Allow client connects without authentication.
1423
1424@item disable-copy-paste
1425Disable copy paste between the client and the guest.
1426
1427@item disable-agent-file-xfer
1428Disable spice-vdagent based file-xfer between the client and the guest.
1429
1430@item tls-port=<nr>
1431Set the TCP port spice is listening on for encrypted channels.
1432
1433@item x509-dir=<dir>
1434Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1435
1436@item x509-key-file=<file>
1437@itemx x509-key-password=<file>
1438@itemx x509-cert-file=<file>
1439@itemx x509-cacert-file=<file>
1440@itemx x509-dh-key-file=<file>
1441The x509 file names can also be configured individually.
1442
1443@item tls-ciphers=<list>
1444Specify which ciphers to use.
1445
1446@item tls-channel=[main|display|cursor|inputs|record|playback]
1447@itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1448Force specific channel to be used with or without TLS encryption.  The
1449options can be specified multiple times to configure multiple
1450channels.  The special name "default" can be used to set the default
1451mode.  For channels which are not explicitly forced into one mode the
1452spice client is allowed to pick tls/plaintext as he pleases.
1453
1454@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1455Configure image compression (lossless).
1456Default is auto_glz.
1457
1458@item jpeg-wan-compression=[auto|never|always]
1459@itemx zlib-glz-wan-compression=[auto|never|always]
1460Configure wan image compression (lossy for slow links).
1461Default is auto.
1462
1463@item streaming-video=[off|all|filter]
1464Configure video stream detection.  Default is off.
1465
1466@item agent-mouse=[on|off]
1467Enable/disable passing mouse events via vdagent.  Default is on.
1468
1469@item playback-compression=[on|off]
1470Enable/disable audio stream compression (using celt 0.5.1).  Default is on.
1471
1472@item seamless-migration=[on|off]
1473Enable/disable spice seamless migration. Default is off.
1474
1475@item gl=[on|off]
1476Enable/disable OpenGL context. Default is off.
1477
1478@item rendernode=<file>
1479DRM render node for OpenGL rendering. If not specified, it will pick
1480the first available. (Since 2.9)
1481
1482@end table
1483ETEXI
1484
1485DEF("portrait", 0, QEMU_OPTION_portrait,
1486    "-portrait       rotate graphical output 90 deg left (only PXA LCD)\n",
1487    QEMU_ARCH_ALL)
1488STEXI
1489@item -portrait
1490@findex -portrait
1491Rotate graphical output 90 deg left (only PXA LCD).
1492ETEXI
1493
1494DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1495    "-rotate <deg>   rotate graphical output some deg left (only PXA LCD)\n",
1496    QEMU_ARCH_ALL)
1497STEXI
1498@item -rotate @var{deg}
1499@findex -rotate
1500Rotate graphical output some deg left (only PXA LCD).
1501ETEXI
1502
1503DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1504    "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1505    "                select video card type\n", QEMU_ARCH_ALL)
1506STEXI
1507@item -vga @var{type}
1508@findex -vga
1509Select type of VGA card to emulate. Valid values for @var{type} are
1510@table @option
1511@item cirrus
1512Cirrus Logic GD5446 Video card. All Windows versions starting from
1513Windows 95 should recognize and use this graphic card. For optimal
1514performances, use 16 bit color depth in the guest and the host OS.
1515(This card was the default before QEMU 2.2)
1516@item std
1517Standard VGA card with Bochs VBE extensions.  If your guest OS
1518supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1519to use high resolution modes (>= 1280x1024x16) then you should use
1520this option. (This card is the default since QEMU 2.2)
1521@item vmware
1522VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1523recent XFree86/XOrg server or Windows guest with a driver for this
1524card.
1525@item qxl
1526QXL paravirtual graphic card.  It is VGA compatible (including VESA
15272.0 VBE support).  Works best with qxl guest drivers installed though.
1528Recommended choice when using the spice protocol.
1529@item tcx
1530(sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1531sun4m machines and offers both 8-bit and 24-bit colour depths at a
1532fixed resolution of 1024x768.
1533@item cg3
1534(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1535for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1536resolutions aimed at people wishing to run older Solaris versions.
1537@item virtio
1538Virtio VGA card.
1539@item none
1540Disable VGA card.
1541@end table
1542ETEXI
1543
1544DEF("full-screen", 0, QEMU_OPTION_full_screen,
1545    "-full-screen    start in full screen\n", QEMU_ARCH_ALL)
1546STEXI
1547@item -full-screen
1548@findex -full-screen
1549Start in full screen.
1550ETEXI
1551
1552DEF("g", 1, QEMU_OPTION_g ,
1553    "-g WxH[xDEPTH]  Set the initial graphical resolution and depth\n",
1554    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1555STEXI
1556@item -g @var{width}x@var{height}[x@var{depth}]
1557@findex -g
1558Set the initial graphical resolution and depth (PPC, SPARC only).
1559ETEXI
1560
1561DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1562    "-vnc <display>  shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1563STEXI
1564@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1565@findex -vnc
1566Normally, if QEMU is compiled with graphical window support, it displays
1567output such as guest graphics, guest console, and the QEMU monitor in a
1568window. With this option, you can have QEMU listen on VNC display
1569@var{display} and redirect the VGA display over the VNC session. It is
1570very useful to enable the usb tablet device when using this option
1571(option @option{-device usb-tablet}). When using the VNC display, you
1572must use the @option{-k} parameter to set the keyboard layout if you are
1573not using en-us. Valid syntax for the @var{display} is
1574
1575@table @option
1576
1577@item to=@var{L}
1578
1579With this option, QEMU will try next available VNC @var{display}s, until the
1580number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1581available, e.g. port 5900+@var{display} is already used by another
1582application. By default, to=0.
1583
1584@item @var{host}:@var{d}
1585
1586TCP connections will only be allowed from @var{host} on display @var{d}.
1587By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1588be omitted in which case the server will accept connections from any host.
1589
1590@item unix:@var{path}
1591
1592Connections will be allowed over UNIX domain sockets where @var{path} is the
1593location of a unix socket to listen for connections on.
1594
1595@item none
1596
1597VNC is initialized but not started. The monitor @code{change} command
1598can be used to later start the VNC server.
1599
1600@end table
1601
1602Following the @var{display} value there may be one or more @var{option} flags
1603separated by commas. Valid options are
1604
1605@table @option
1606
1607@item reverse
1608
1609Connect to a listening VNC client via a ``reverse'' connection. The
1610client is specified by the @var{display}. For reverse network
1611connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1612is a TCP port number, not a display number.
1613
1614@item websocket
1615
1616Opens an additional TCP listening port dedicated to VNC Websocket connections.
1617If a bare @var{websocket} option is given, the Websocket port is
16185700+@var{display}. An alternative port can be specified with the
1619syntax @code{websocket}=@var{port}.
1620
1621If @var{host} is specified connections will only be allowed from this host.
1622It is possible to control the websocket listen address independently, using
1623the syntax @code{websocket}=@var{host}:@var{port}.
1624
1625If no TLS credentials are provided, the websocket connection runs in
1626unencrypted mode. If TLS credentials are provided, the websocket connection
1627requires encrypted client connections.
1628
1629@item password
1630
1631Require that password based authentication is used for client connections.
1632
1633The password must be set separately using the @code{set_password} command in
1634the @ref{pcsys_monitor}. The syntax to change your password is:
1635@code{set_password <protocol> <password>} where <protocol> could be either
1636"vnc" or "spice".
1637
1638If you would like to change <protocol> password expiration, you should use
1639@code{expire_password <protocol> <expiration-time>} where expiration time could
1640be one of the following options: now, never, +seconds or UNIX time of
1641expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1642to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1643date and time).
1644
1645You can also use keywords "now" or "never" for the expiration time to
1646allow <protocol> password to expire immediately or never expire.
1647
1648@item tls-creds=@var{ID}
1649
1650Provides the ID of a set of TLS credentials to use to secure the
1651VNC server. They will apply to both the normal VNC server socket
1652and the websocket socket (if enabled). Setting TLS credentials
1653will cause the VNC server socket to enable the VeNCrypt auth
1654mechanism.  The credentials should have been previously created
1655using the @option{-object tls-creds} argument.
1656
1657The @option{tls-creds} parameter obsoletes the @option{tls},
1658@option{x509}, and @option{x509verify} options, and as such
1659it is not permitted to set both new and old type options at
1660the same time.
1661
1662@item tls
1663
1664Require that client use TLS when communicating with the VNC server. This
1665uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1666attack. It is recommended that this option be combined with either the
1667@option{x509} or @option{x509verify} options.
1668
1669This option is now deprecated in favor of using the @option{tls-creds}
1670argument.
1671
1672@item x509=@var{/path/to/certificate/dir}
1673
1674Valid if @option{tls} is specified. Require that x509 credentials are used
1675for negotiating the TLS session. The server will send its x509 certificate
1676to the client. It is recommended that a password be set on the VNC server
1677to provide authentication of the client when this is used. The path following
1678this option specifies where the x509 certificates are to be loaded from.
1679See the @ref{vnc_security} section for details on generating certificates.
1680
1681This option is now deprecated in favour of using the @option{tls-creds}
1682argument.
1683
1684@item x509verify=@var{/path/to/certificate/dir}
1685
1686Valid if @option{tls} is specified. Require that x509 credentials are used
1687for negotiating the TLS session. The server will send its x509 certificate
1688to the client, and request that the client send its own x509 certificate.
1689The server will validate the client's certificate against the CA certificate,
1690and reject clients when validation fails. If the certificate authority is
1691trusted, this is a sufficient authentication mechanism. You may still wish
1692to set a password on the VNC server as a second authentication layer. The
1693path following this option specifies where the x509 certificates are to
1694be loaded from. See the @ref{vnc_security} section for details on generating
1695certificates.
1696
1697This option is now deprecated in favour of using the @option{tls-creds}
1698argument.
1699
1700@item sasl
1701
1702Require that the client use SASL to authenticate with the VNC server.
1703The exact choice of authentication method used is controlled from the
1704system / user's SASL configuration file for the 'qemu' service. This
1705is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1706unprivileged user, an environment variable SASL_CONF_PATH can be used
1707to make it search alternate locations for the service config.
1708While some SASL auth methods can also provide data encryption (eg GSSAPI),
1709it is recommended that SASL always be combined with the 'tls' and
1710'x509' settings to enable use of SSL and server certificates. This
1711ensures a data encryption preventing compromise of authentication
1712credentials. See the @ref{vnc_security} section for details on using
1713SASL authentication.
1714
1715@item acl
1716
1717Turn on access control lists for checking of the x509 client certificate
1718and SASL party. For x509 certs, the ACL check is made against the
1719certificate's distinguished name. This is something that looks like
1720@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1721made against the username, which depending on the SASL plugin, may
1722include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1723When the @option{acl} flag is set, the initial access list will be
1724empty, with a @code{deny} policy. Thus no one will be allowed to
1725use the VNC server until the ACLs have been loaded. This can be
1726achieved using the @code{acl} monitor command.
1727
1728@item lossy
1729
1730Enable lossy compression methods (gradient, JPEG, ...). If this
1731option is set, VNC client may receive lossy framebuffer updates
1732depending on its encoding settings. Enabling this option can save
1733a lot of bandwidth at the expense of quality.
1734
1735@item non-adaptive
1736
1737Disable adaptive encodings. Adaptive encodings are enabled by default.
1738An adaptive encoding will try to detect frequently updated screen regions,
1739and send updates in these regions using a lossy encoding (like JPEG).
1740This can be really helpful to save bandwidth when playing videos. Disabling
1741adaptive encodings restores the original static behavior of encodings
1742like Tight.
1743
1744@item share=[allow-exclusive|force-shared|ignore]
1745
1746Set display sharing policy.  'allow-exclusive' allows clients to ask
1747for exclusive access.  As suggested by the rfb spec this is
1748implemented by dropping other connections.  Connecting multiple
1749clients in parallel requires all clients asking for a shared session
1750(vncviewer: -shared switch).  This is the default.  'force-shared'
1751disables exclusive client access.  Useful for shared desktop sessions,
1752where you don't want someone forgetting specify -shared disconnect
1753everybody else.  'ignore' completely ignores the shared flag and
1754allows everybody connect unconditionally.  Doesn't conform to the rfb
1755spec but is traditional QEMU behavior.
1756
1757@item key-delay-ms
1758
1759Set keyboard delay, for key down and key up events, in milliseconds.
1760Default is 10.  Keyboards are low-bandwidth devices, so this slowdown
1761can help the device and guest to keep up and not lose events in case
1762events are arriving in bulk.  Possible causes for the latter are flaky
1763network connections, or scripts for automated testing.
1764
1765@end table
1766ETEXI
1767
1768STEXI
1769@end table
1770ETEXI
1771ARCHHEADING(, QEMU_ARCH_I386)
1772
1773ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1774STEXI
1775@table @option
1776ETEXI
1777
1778DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1779    "-win2k-hack     use it when installing Windows 2000 to avoid a disk full bug\n",
1780    QEMU_ARCH_I386)
1781STEXI
1782@item -win2k-hack
1783@findex -win2k-hack
1784Use it when installing Windows 2000 to avoid a disk full bug. After
1785Windows 2000 is installed, you no longer need this option (this option
1786slows down the IDE transfers).
1787ETEXI
1788
1789HXCOMM Deprecated by -rtc
1790DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1791
1792DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1793    "-no-fd-bootchk  disable boot signature checking for floppy disks\n",
1794    QEMU_ARCH_I386)
1795STEXI
1796@item -no-fd-bootchk
1797@findex -no-fd-bootchk
1798Disable boot signature checking for floppy disks in BIOS. May
1799be needed to boot from old floppy disks.
1800ETEXI
1801
1802DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1803           "-no-acpi        disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1804STEXI
1805@item -no-acpi
1806@findex -no-acpi
1807Disable ACPI (Advanced Configuration and Power Interface) support. Use
1808it if your guest OS complains about ACPI problems (PC target machine
1809only).
1810ETEXI
1811
1812DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1813    "-no-hpet        disable HPET\n", QEMU_ARCH_I386)
1814STEXI
1815@item -no-hpet
1816@findex -no-hpet
1817Disable HPET support.
1818ETEXI
1819
1820DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1821    "-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"
1822    "                ACPI table description\n", QEMU_ARCH_I386)
1823STEXI
1824@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}]...]
1825@findex -acpitable
1826Add ACPI table with specified header fields and context from specified files.
1827For file=, take whole ACPI table from the specified files, including all
1828ACPI headers (possible overridden by other options).
1829For data=, only data
1830portion of the table is used, all header information is specified in the
1831command line.
1832If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1833fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1834to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1835spec.
1836ETEXI
1837
1838DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1839    "-smbios file=binary\n"
1840    "                load SMBIOS entry from binary file\n"
1841    "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1842    "              [,uefi=on|off]\n"
1843    "                specify SMBIOS type 0 fields\n"
1844    "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1845    "              [,uuid=uuid][,sku=str][,family=str]\n"
1846    "                specify SMBIOS type 1 fields\n"
1847    "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1848    "              [,asset=str][,location=str]\n"
1849    "                specify SMBIOS type 2 fields\n"
1850    "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1851    "              [,sku=str]\n"
1852    "                specify SMBIOS type 3 fields\n"
1853    "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1854    "              [,asset=str][,part=str]\n"
1855    "                specify SMBIOS type 4 fields\n"
1856    "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1857    "               [,asset=str][,part=str][,speed=%d]\n"
1858    "                specify SMBIOS type 17 fields\n",
1859    QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1860STEXI
1861@item -smbios file=@var{binary}
1862@findex -smbios
1863Load SMBIOS entry from binary file.
1864
1865@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1866Specify SMBIOS type 0 fields
1867
1868@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}]
1869Specify SMBIOS type 1 fields
1870
1871@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}]
1872Specify SMBIOS type 2 fields
1873
1874@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1875Specify SMBIOS type 3 fields
1876
1877@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1878Specify SMBIOS type 4 fields
1879
1880@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}]
1881Specify SMBIOS type 17 fields
1882ETEXI
1883
1884STEXI
1885@end table
1886ETEXI
1887DEFHEADING()
1888
1889DEFHEADING(Network options:)
1890STEXI
1891@table @option
1892ETEXI
1893
1894HXCOMM Legacy slirp options (now moved to -net user):
1895#ifdef CONFIG_SLIRP
1896DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1897DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1898DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1899#ifndef _WIN32
1900DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1901#endif
1902#endif
1903
1904DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1905#ifdef CONFIG_SLIRP
1906    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1907    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1908    "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1909    "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1910    "         [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1911#ifndef _WIN32
1912                                             "[,smb=dir[,smbserver=addr]]\n"
1913#endif
1914    "                configure a user mode network backend with ID 'str',\n"
1915    "                its DHCP server and optional services\n"
1916#endif
1917#ifdef _WIN32
1918    "-netdev tap,id=str,ifname=name\n"
1919    "                configure a host TAP network backend with ID 'str'\n"
1920#else
1921    "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1922    "         [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1923    "         [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1924    "         [,poll-us=n]\n"
1925    "                configure a host TAP network backend with ID 'str'\n"
1926    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1927    "                use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1928    "                to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1929    "                to deconfigure it\n"
1930    "                use '[down]script=no' to disable script execution\n"
1931    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1932    "                configure it\n"
1933    "                use 'fd=h' to connect to an already opened TAP interface\n"
1934    "                use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1935    "                use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1936    "                default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1937    "                use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1938    "                use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1939    "                use vhost=on to enable experimental in kernel accelerator\n"
1940    "                    (only has effect for virtio guests which use MSIX)\n"
1941    "                use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1942    "                use 'vhostfd=h' to connect to an already opened vhost net device\n"
1943    "                use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1944    "                use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1945    "                use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1946    "                spent on busy polling for vhost net\n"
1947    "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1948    "                configure a host TAP network backend with ID 'str' that is\n"
1949    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1950    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1951#endif
1952#ifdef __linux__
1953    "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1954    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1955    "         [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1956    "         [,rxcookie=rxcookie][,offset=offset]\n"
1957    "                configure a network backend with ID 'str' connected to\n"
1958    "                an Ethernet over L2TPv3 pseudowire.\n"
1959    "                Linux kernel 3.3+ as well as most routers can talk\n"
1960    "                L2TPv3. This transport allows connecting a VM to a VM,\n"
1961    "                VM to a router and even VM to Host. It is a nearly-universal\n"
1962    "                standard (RFC3391). Note - this implementation uses static\n"
1963    "                pre-configured tunnels (same as the Linux kernel).\n"
1964    "                use 'src=' to specify source address\n"
1965    "                use 'dst=' to specify destination address\n"
1966    "                use 'udp=on' to specify udp encapsulation\n"
1967    "                use 'srcport=' to specify source udp port\n"
1968    "                use 'dstport=' to specify destination udp port\n"
1969    "                use 'ipv6=on' to force v6\n"
1970    "                L2TPv3 uses cookies to prevent misconfiguration as\n"
1971    "                well as a weak security measure\n"
1972    "                use 'rxcookie=0x012345678' to specify a rxcookie\n"
1973    "                use 'txcookie=0x012345678' to specify a txcookie\n"
1974    "                use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1975    "                use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1976    "                use 'pincounter=on' to work around broken counter handling in peer\n"
1977    "                use 'offset=X' to add an extra offset between header and data\n"
1978#endif
1979    "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1980    "                configure a network backend to connect to another network\n"
1981    "                using a socket connection\n"
1982    "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1983    "                configure a network backend to connect to a multicast maddr and port\n"
1984    "                use 'localaddr=addr' to specify the host address to send packets from\n"
1985    "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1986    "                configure a network backend to connect to another network\n"
1987    "                using an UDP tunnel\n"
1988#ifdef CONFIG_VDE
1989    "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1990    "                configure a network backend to connect to port 'n' of a vde switch\n"
1991    "                running on host and listening for incoming connections on 'socketpath'.\n"
1992    "                Use group 'groupname' and mode 'octalmode' to change default\n"
1993    "                ownership and permissions for communication port.\n"
1994#endif
1995#ifdef CONFIG_NETMAP
1996    "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1997    "                attach to the existing netmap-enabled network interface 'name', or to a\n"
1998    "                VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1999    "                netmap device, defaults to '/dev/netmap')\n"
2000#endif
2001#ifdef CONFIG_POSIX
2002    "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2003    "                configure a vhost-user network, backed by a chardev 'dev'\n"
2004#endif
2005    "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
2006    "                configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
2007DEF("nic", HAS_ARG, QEMU_OPTION_nic,
2008    "--nic [tap|bridge|"
2009#ifdef CONFIG_SLIRP
2010    "user|"
2011#endif
2012#ifdef __linux__
2013    "l2tpv3|"
2014#endif
2015#ifdef CONFIG_VDE
2016    "vde|"
2017#endif
2018#ifdef CONFIG_NETMAP
2019    "netmap|"
2020#endif
2021#ifdef CONFIG_POSIX
2022    "vhost-user|"
2023#endif
2024    "socket][,option][,...][mac=macaddr]\n"
2025    "                initialize an on-board / default host NIC (using MAC address\n"
2026    "                macaddr) and connect it to the given host network backend\n"
2027    "--nic none      use it alone to have zero network devices (the default is to\n"
2028    "                provided a 'user' network connection)\n",
2029    QEMU_ARCH_ALL)
2030DEF("net", HAS_ARG, QEMU_OPTION_net,
2031    "-net nic[,vlan=n][,netdev=nd][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2032    "                configure or create an on-board (or machine default) NIC and\n"
2033    "                connect it either to VLAN 'n' or the netdev 'nd' (for pluggable\n"
2034    "                NICs please use '-device devtype,netdev=nd' instead)\n"
2035    "-net ["
2036#ifdef CONFIG_SLIRP
2037    "user|"
2038#endif
2039    "tap|"
2040    "bridge|"
2041#ifdef CONFIG_VDE
2042    "vde|"
2043#endif
2044#ifdef CONFIG_NETMAP
2045    "netmap|"
2046#endif
2047    "socket][,vlan=n][,option][,option][,...]\n"
2048    "                old way to initialize a host network interface\n"
2049    "                (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2050STEXI
2051@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]
2052@findex -nic
2053This option is a shortcut for configuring both the on-board (default) guest
2054NIC hardware and the host network backend in one go. The host backend options
2055are the same as with the corresponding @option{-netdev} options below.
2056The guest NIC model can be set with @option{model=@var{modelname}}.
2057Use @option{model=help} to list the available device types.
2058The hardware MAC address can be set with @option{mac=@var{macaddr}}.
2059
2060The following two example do exactly the same, to show how @option{-nic} can
2061be used to shorten the command line length (note that the e1000 is the default
2062on i386, so the @option{model=e1000} parameter could even be omitted here, too):
2063@example
2064qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2065qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2066@end example
2067
2068@item -nic none
2069Indicate that no network devices should be configured. It is used to override
2070the default configuration (default NIC with ``user'' host network backend)
2071which is activated if no other networking options are provided.
2072
2073@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2074@findex -netdev
2075Configure user mode host network backend which requires no administrator
2076privilege to run. Valid options are:
2077
2078@table @option
2079@item id=@var{id}
2080Assign symbolic name for use in monitor commands.
2081
2082@item ipv4=on|off and ipv6=on|off
2083Specify that either IPv4 or IPv6 must be enabled. If neither is specified
2084both protocols are enabled.
2085
2086@item net=@var{addr}[/@var{mask}]
2087Set IP network address the guest will see. Optionally specify the netmask,
2088either in the form a.b.c.d or as number of valid top-most bits. Default is
208910.0.2.0/24.
2090
2091@item host=@var{addr}
2092Specify the guest-visible address of the host. Default is the 2nd IP in the
2093guest network, i.e. x.x.x.2.
2094
2095@item ipv6-net=@var{addr}[/@var{int}]
2096Set IPv6 network address the guest will see (default is fec0::/64). The
2097network prefix is given in the usual hexadecimal IPv6 address
2098notation. The prefix size is optional, and is given as the number of
2099valid top-most bits (default is 64).
2100
2101@item ipv6-host=@var{addr}
2102Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2103the guest network, i.e. xxxx::2.
2104
2105@item restrict=on|off
2106If this option is enabled, the guest will be isolated, i.e. it will not be
2107able to contact the host and no guest IP packets will be routed over the host
2108to the outside. This option does not affect any explicitly set forwarding rules.
2109
2110@item hostname=@var{name}
2111Specifies the client hostname reported by the built-in DHCP server.
2112
2113@item dhcpstart=@var{addr}
2114Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2115is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2116
2117@item dns=@var{addr}
2118Specify the guest-visible address of the virtual nameserver. The address must
2119be different from the host address. Default is the 3rd IP in the guest network,
2120i.e. x.x.x.3.
2121
2122@item ipv6-dns=@var{addr}
2123Specify the guest-visible address of the IPv6 virtual nameserver. The address
2124must be different from the host address. Default is the 3rd IP in the guest
2125network, i.e. xxxx::3.
2126
2127@item dnssearch=@var{domain}
2128Provides an entry for the domain-search list sent by the built-in
2129DHCP server. More than one domain suffix can be transmitted by specifying
2130this option multiple times. If supported, this will cause the guest to
2131automatically try to append the given domain suffix(es) in case a domain name
2132can not be resolved.
2133
2134Example:
2135@example
2136qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2137@end example
2138
2139@item tftp=@var{dir}
2140When using the user mode network stack, activate a built-in TFTP
2141server. The files in @var{dir} will be exposed as the root of a TFTP server.
2142The TFTP client on the guest must be configured in binary mode (use the command
2143@code{bin} of the Unix TFTP client).
2144
2145@item bootfile=@var{file}
2146When using the user mode network stack, broadcast @var{file} as the BOOTP
2147filename. In conjunction with @option{tftp}, this can be used to network boot
2148a guest from a local directory.
2149
2150Example (using pxelinux):
2151@example
2152qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
2153    -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2154@end example
2155
2156@item smb=@var{dir}[,smbserver=@var{addr}]
2157When using the user mode network stack, activate a built-in SMB
2158server so that Windows OSes can access to the host files in @file{@var{dir}}
2159transparently. The IP address of the SMB server can be set to @var{addr}. By
2160default the 4th IP in the guest network is used, i.e. x.x.x.4.
2161
2162In the guest Windows OS, the line:
2163@example
216410.0.2.4 smbserver
2165@end example
2166must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2167or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2168
2169Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2170
2171Note that a SAMBA server must be installed on the host OS.
2172
2173@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2174Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2175the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2176@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2177given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2178be bound to a specific host interface. If no connection type is set, TCP is
2179used. This option can be given multiple times.
2180
2181For example, to redirect host X11 connection from screen 1 to guest
2182screen 0, use the following:
2183
2184@example
2185# on the host
2186qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
2187# this host xterm should open in the guest X11 server
2188xterm -display :1
2189@end example
2190
2191To redirect telnet connections from host port 5555 to telnet port on
2192the guest, use the following:
2193
2194@example
2195# on the host
2196qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
2197telnet localhost 5555
2198@end example
2199
2200Then when you use on the host @code{telnet localhost 5555}, you
2201connect to the guest telnet server.
2202
2203@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2204@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2205Forward guest TCP connections to the IP address @var{server} on port @var{port}
2206to the character device @var{dev} or to a program executed by @var{cmd:command}
2207which gets spawned for each connection. This option can be given multiple times.
2208
2209You can either use a chardev directly and have that one used throughout QEMU's
2210lifetime, like in the following example:
2211
2212@example
2213# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2214# the guest accesses it
2215qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
2216@end example
2217
2218Or you can execute a command on every TCP connection established by the guest,
2219so that QEMU behaves similar to an inetd process for that virtual server:
2220
2221@example
2222# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2223# and connect the TCP stream to its stdin/stdout
2224qemu-system-i386 -nic  'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2225@end example
2226
2227@end table
2228
2229Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2230processed and applied to -net user. Mixing them with the new configuration
2231syntax gives undefined results. Their use for new applications is discouraged
2232as they will be removed from future versions.
2233
2234@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2235Configure a host TAP network backend with ID @var{id}.
2236
2237Use the network script @var{file} to configure it and the network script
2238@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2239automatically provides one. The default network configure script is
2240@file{/etc/qemu-ifup} and the default network deconfigure script is
2241@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2242to disable script execution.
2243
2244If running QEMU as an unprivileged user, use the network helper
2245@var{helper} to configure the TAP interface and attach it to the bridge.
2246The default network helper executable is @file{/path/to/qemu-bridge-helper}
2247and the default bridge device is @file{br0}.
2248
2249@option{fd}=@var{h} can be used to specify the handle of an already
2250opened host TAP interface.
2251
2252Examples:
2253
2254@example
2255#launch a QEMU instance with the default network script
2256qemu-system-i386 linux.img -nic tap
2257@end example
2258
2259@example
2260#launch a QEMU instance with two NICs, each one connected
2261#to a TAP device
2262qemu-system-i386 linux.img \
2263        -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
2264        -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
2265@end example
2266
2267@example
2268#launch a QEMU instance with the default network helper to
2269#connect a TAP device to bridge br0
2270qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
2271        -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
2272@end example
2273
2274@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2275Connect a host TAP network interface to a host bridge device.
2276
2277Use the network helper @var{helper} to configure the TAP interface and
2278attach it to the bridge. The default network helper executable is
2279@file{/path/to/qemu-bridge-helper} and the default bridge
2280device is @file{br0}.
2281
2282Examples:
2283
2284@example
2285#launch a QEMU instance with the default network helper to
2286#connect a TAP device to bridge br0
2287qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
2288@end example
2289
2290@example
2291#launch a QEMU instance with the default network helper to
2292#connect a TAP device to bridge qemubr0
2293qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
2294@end example
2295
2296@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2297
2298This host network backend can be used to connect the guest's network to
2299another QEMU virtual machine using a TCP socket connection. If @option{listen}
2300is specified, QEMU waits for incoming connections on @var{port}
2301(@var{host} is optional). @option{connect} is used to connect to
2302another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2303specifies an already opened TCP socket.
2304
2305Example:
2306@example
2307# launch a first QEMU instance
2308qemu-system-i386 linux.img \
2309                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2310                 -netdev socket,id=n1,listen=:1234
2311# connect the network of this instance to the network of the first instance
2312qemu-system-i386 linux.img \
2313                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2314                 -netdev socket,id=n2,connect=127.0.0.1:1234
2315@end example
2316
2317@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2318
2319Configure a socket host network backend to share the guest's network traffic
2320with another QEMU virtual machines using a UDP multicast socket, effectively
2321making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
2322NOTES:
2323@enumerate
2324@item
2325Several QEMU can be running on different hosts and share same bus (assuming
2326correct multicast setup for these hosts).
2327@item
2328mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2329@url{http://user-mode-linux.sf.net}.
2330@item
2331Use @option{fd=h} to specify an already opened UDP multicast socket.
2332@end enumerate
2333
2334Example:
2335@example
2336# launch one QEMU instance
2337qemu-system-i386 linux.img \
2338                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2339                 -netdev socket,id=n1,mcast=230.0.0.1:1234
2340# launch another QEMU instance on same "bus"
2341qemu-system-i386 linux.img \
2342                 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \
2343                 -netdev socket,id=n2,mcast=230.0.0.1:1234
2344# launch yet another QEMU instance on same "bus"
2345qemu-system-i386 linux.img \
2346                 -device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \
2347                 -netdev socket,id=n3,mcast=230.0.0.1:1234
2348@end example
2349
2350Example (User Mode Linux compat.):
2351@example
2352# launch QEMU instance (note mcast address selected is UML's default)
2353qemu-system-i386 linux.img \
2354                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2355                 -netdev socket,id=n1,mcast=239.192.168.1:1102
2356# launch UML
2357/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2358@end example
2359
2360Example (send packets from host's 1.2.3.4):
2361@example
2362qemu-system-i386 linux.img \
2363                 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \
2364                 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2365@end example
2366
2367@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}]
2368Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
2369popular protocol to transport Ethernet (and other Layer 2) data frames between
2370two systems. It is present in routers, firewalls and the Linux kernel
2371(from version 3.3 onwards).
2372
2373This transport allows a VM to communicate to another VM, router or firewall directly.
2374
2375@table @option
2376@item src=@var{srcaddr}
2377    source address (mandatory)
2378@item dst=@var{dstaddr}
2379    destination address (mandatory)
2380@item udp
2381    select udp encapsulation (default is ip).
2382@item srcport=@var{srcport}
2383    source udp port.
2384@item dstport=@var{dstport}
2385    destination udp port.
2386@item ipv6
2387    force v6, otherwise defaults to v4.
2388@item rxcookie=@var{rxcookie}
2389@itemx txcookie=@var{txcookie}
2390    Cookies are a weak form of security in the l2tpv3 specification.
2391Their function is mostly to prevent misconfiguration. By default they are 32
2392bit.
2393@item cookie64
2394    Set cookie size to 64 bit instead of the default 32
2395@item counter=off
2396    Force a 'cut-down' L2TPv3 with no counter as in
2397draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2398@item pincounter=on
2399    Work around broken counter handling in peer. This may also help on
2400networks which have packet reorder.
2401@item offset=@var{offset}
2402    Add an extra offset between header and data
2403@end table
2404
2405For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2406on the remote Linux host 1.2.3.4:
2407@example
2408# Setup tunnel on linux host using raw ip as encapsulation
2409# on 1.2.3.4
2410ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2411    encap udp udp_sport 16384 udp_dport 16384
2412ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2413    0xFFFFFFFF peer_session_id 0xFFFFFFFF
2414ifconfig vmtunnel0 mtu 1500
2415ifconfig vmtunnel0 up
2416brctl addif br-lan vmtunnel0
2417
2418
2419# on 4.3.2.1
2420# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2421
2422qemu-system-i386 linux.img -device e1000,netdev=n1 \
2423    -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2424
2425@end example
2426
2427@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2428Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
2429listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2430and MODE @var{octalmode} to change default ownership and permissions for
2431communication port. This option is only available if QEMU has been compiled
2432with vde support enabled.
2433
2434Example:
2435@example
2436# launch vde switch
2437vde_switch -F -sock /tmp/myswitch
2438# launch QEMU instance
2439qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
2440@end example
2441
2442@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2443
2444Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2445be a unix domain socket backed one. The vhost-user uses a specifically defined
2446protocol to pass vhost ioctl replacement messages to an application on the other
2447end of the socket. On non-MSIX guests, the feature can be forced with
2448@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2449be created for multiqueue vhost-user.
2450
2451Example:
2452@example
2453qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2454     -numa node,memdev=mem \
2455     -chardev socket,id=chr0,path=/path/to/socket \
2456     -netdev type=vhost-user,id=net0,chardev=chr0 \
2457     -device virtio-net-pci,netdev=net0
2458@end example
2459
2460@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
2461
2462Create a hub port on the emulated hub with ID @var{hubid}.
2463
2464The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
2465single netdev. @code{-net} and @code{-device} with the parameter @option{vlan}
2466(deprecated), or @code{-nic hubport} can also be used to connect a
2467network device or a NIC to a hub. Alternatively, you can also connect the
2468hubport to another netdev with ID @var{nd} by using the @option{netdev=@var{nd}}
2469option.
2470
2471@item -net nic[,vlan=@var{n}][,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2472@findex -net
2473Legacy option to configure or create an on-board (or machine default) Network
2474Interface Card(NIC) and connect it either to the emulated hub port ("vlan")
2475with number @var{n} (@var{n} = 0 is the default), or to the netdev @var{nd}.
2476The NIC is an e1000 by default on the PC target. Optionally, the MAC address
2477can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
2478only), and a @var{name} can be assigned for use in monitor commands.
2479Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2480that the card should have; this option currently only affects virtio cards; set
2481@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2482NIC is created.  QEMU can emulate several different models of network card.
2483Use @code{-net nic,model=help} for a list of available devices for your target.
2484
2485@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,vlan=@var{n}][,name=@var{name}]
2486Configure a host network backend (with the options corresponding to the same
2487@option{-netdev} option) and connect it to the emulated hub ("vlan") with the
2488number @var{n} (default is number 0). Use @var{name} to specify the name of the
2489hub port.
2490ETEXI
2491
2492STEXI
2493@end table
2494ETEXI
2495DEFHEADING()
2496
2497DEFHEADING(Character device options:)
2498
2499DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2500    "-chardev help\n"
2501    "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2502    "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2503    "         [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2504    "         [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2505    "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2506    "         [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2507    "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2508    "         [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2509    "         [,logfile=PATH][,logappend=on|off]\n"
2510    "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2511    "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2512    "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2513    "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2514    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2515    "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2516#ifdef _WIN32
2517    "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2518    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2519#else
2520    "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2521    "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2522#endif
2523#ifdef CONFIG_BRLAPI
2524    "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2525#endif
2526#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2527        || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2528    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2529    "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2530#endif
2531#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2532    "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2533    "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2534#endif
2535#if defined(CONFIG_SPICE)
2536    "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2537    "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2538#endif
2539    , QEMU_ARCH_ALL
2540)
2541
2542STEXI
2543
2544The general form of a character device option is:
2545@table @option
2546@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}]
2547@findex -chardev
2548Backend is one of:
2549@option{null},
2550@option{socket},
2551@option{udp},
2552@option{msmouse},
2553@option{vc},
2554@option{ringbuf},
2555@option{file},
2556@option{pipe},
2557@option{console},
2558@option{serial},
2559@option{pty},
2560@option{stdio},
2561@option{braille},
2562@option{tty},
2563@option{parallel},
2564@option{parport},
2565@option{spicevmc},
2566@option{spiceport}.
2567The specific backend will determine the applicable options.
2568
2569Use @code{-chardev help} to print all available chardev backend types.
2570
2571All devices must have an id, which can be any string up to 127 characters long.
2572It is used to uniquely identify this device in other command line directives.
2573
2574A character device may be used in multiplexing mode by multiple front-ends.
2575Specify @option{mux=on} to enable this mode.
2576A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2577backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2578If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2579create a multiplexer with your specified ID, and you can then configure multiple
2580front ends to use that chardev ID for their input/output. Up to four different
2581front ends can be connected to a single multiplexed chardev. (Without
2582multiplexing enabled, a chardev can only be used by a single front end.)
2583For instance you could use this to allow a single stdio chardev to be used by
2584two serial ports and the QEMU monitor:
2585
2586@example
2587-chardev stdio,mux=on,id=char0 \
2588-mon chardev=char0,mode=readline \
2589-serial chardev:char0 \
2590-serial chardev:char0
2591@end example
2592
2593You can have more than one multiplexer in a system configuration; for instance
2594you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2595multiplexed between the QEMU monitor and a parallel port:
2596
2597@example
2598-chardev stdio,mux=on,id=char0 \
2599-mon chardev=char0,mode=readline \
2600-parallel chardev:char0 \
2601-chardev tcp,...,mux=on,id=char1 \
2602-serial chardev:char1 \
2603-serial chardev:char1
2604@end example
2605
2606When you're using a multiplexed character device, some escape sequences are
2607interpreted in the input. @xref{mux_keys, Keys in the character backend
2608multiplexer}.
2609
2610Note that some other command line options may implicitly create multiplexed
2611character backends; for instance @option{-serial mon:stdio} creates a
2612multiplexed stdio backend connected to the serial port and the QEMU monitor,
2613and @option{-nographic} also multiplexes the console and the monitor to
2614stdio.
2615
2616There is currently no support for multiplexing in the other direction
2617(where a single QEMU front end takes input and output from multiple chardevs).
2618
2619Every backend supports the @option{logfile} option, which supplies the path
2620to a file to record all data transmitted via the backend. The @option{logappend}
2621option controls whether the log file will be truncated or appended to when
2622opened.
2623
2624@end table
2625
2626The available backends are:
2627
2628@table @option
2629@item -chardev null,id=@var{id}
2630A void device. This device will not emit any data, and will drop any data it
2631receives. The null backend does not take any options.
2632
2633@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}]
2634
2635Create a two-way stream socket, which can be either a TCP or a unix socket. A
2636unix socket will be created if @option{path} is specified. Behaviour is
2637undefined if TCP options are specified for a unix socket.
2638
2639@option{server} specifies that the socket shall be a listening socket.
2640
2641@option{nowait} specifies that QEMU should not block waiting for a client to
2642connect to a listening socket.
2643
2644@option{telnet} specifies that traffic on the socket should interpret telnet
2645escape sequences.
2646
2647@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2648the remote end goes away.  qemu will delay this many seconds and then attempt
2649to reconnect.  Zero disables reconnecting, and is the default.
2650
2651@option{tls-creds} requests enablement of the TLS protocol for encryption,
2652and specifies the id of the TLS credentials to use for the handshake. The
2653credentials must be previously created with the @option{-object tls-creds}
2654argument.
2655
2656TCP and unix socket options are given below:
2657
2658@table @option
2659
2660@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay]
2661
2662@option{host} for a listening socket specifies the local address to be bound.
2663For a connecting socket species the remote host to connect to. @option{host} is
2664optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2665
2666@option{port} for a listening socket specifies the local port to be bound. For a
2667connecting socket specifies the port on the remote host to connect to.
2668@option{port} can be given as either a port number or a service name.
2669@option{port} is required.
2670
2671@option{to} is only relevant to listening sockets. If it is specified, and
2672@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2673to and including @option{to} until it succeeds. @option{to} must be specified
2674as a port number.
2675
2676@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2677If neither is specified the socket may use either protocol.
2678
2679@option{nodelay} disables the Nagle algorithm.
2680
2681@item unix options: path=@var{path}
2682
2683@option{path} specifies the local path of the unix socket. @option{path} is
2684required.
2685
2686@end table
2687
2688@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6]
2689
2690Sends all traffic from the guest to a remote host over UDP.
2691
2692@option{host} specifies the remote host to connect to. If not specified it
2693defaults to @code{localhost}.
2694
2695@option{port} specifies the port on the remote host to connect to. @option{port}
2696is required.
2697
2698@option{localaddr} specifies the local address to bind to. If not specified it
2699defaults to @code{0.0.0.0}.
2700
2701@option{localport} specifies the local port to bind to. If not specified any
2702available local port will be used.
2703
2704@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2705If neither is specified the device may use either protocol.
2706
2707@item -chardev msmouse,id=@var{id}
2708
2709Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2710take any options.
2711
2712@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]]
2713
2714Connect to a QEMU text console. @option{vc} may optionally be given a specific
2715size.
2716
2717@option{width} and @option{height} specify the width and height respectively of
2718the console, in pixels.
2719
2720@option{cols} and @option{rows} specify that the console be sized to fit a text
2721console with the given dimensions.
2722
2723@item -chardev ringbuf,id=@var{id}[,size=@var{size}]
2724
2725Create a ring buffer with fixed size @option{size}.
2726@var{size} must be a power of two and defaults to @code{64K}.
2727
2728@item -chardev file,id=@var{id},path=@var{path}
2729
2730Log all traffic received from the guest to a file.
2731
2732@option{path} specifies the path of the file to be opened. This file will be
2733created if it does not already exist, and overwritten if it does. @option{path}
2734is required.
2735
2736@item -chardev pipe,id=@var{id},path=@var{path}
2737
2738Create a two-way connection to the guest. The behaviour differs slightly between
2739Windows hosts and other hosts:
2740
2741On Windows, a single duplex pipe will be created at
2742@file{\\.pipe\@option{path}}.
2743
2744On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2745@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2746received by the guest. Data written by the guest can be read from
2747@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2748be present.
2749
2750@option{path} forms part of the pipe path as described above. @option{path} is
2751required.
2752
2753@item -chardev console,id=@var{id}
2754
2755Send traffic from the guest to QEMU's standard output. @option{console} does not
2756take any options.
2757
2758@option{console} is only available on Windows hosts.
2759
2760@item -chardev serial,id=@var{id},path=@option{path}
2761
2762Send traffic from the guest to a serial device on the host.
2763
2764On Unix hosts serial will actually accept any tty device,
2765not only serial lines.
2766
2767@option{path} specifies the name of the serial device to open.
2768
2769@item -chardev pty,id=@var{id}
2770
2771Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2772not take any options.
2773
2774@option{pty} is not available on Windows hosts.
2775
2776@item -chardev stdio,id=@var{id}[,signal=on|off]
2777Connect to standard input and standard output of the QEMU process.
2778
2779@option{signal} controls if signals are enabled on the terminal, that includes
2780exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2781default, use @option{signal=off} to disable it.
2782
2783@item -chardev braille,id=@var{id}
2784
2785Connect to a local BrlAPI server. @option{braille} does not take any options.
2786
2787@item -chardev tty,id=@var{id},path=@var{path}
2788
2789@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2790DragonFlyBSD hosts.  It is an alias for @option{serial}.
2791
2792@option{path} specifies the path to the tty. @option{path} is required.
2793
2794@item -chardev parallel,id=@var{id},path=@var{path}
2795@itemx -chardev parport,id=@var{id},path=@var{path}
2796
2797@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2798
2799Connect to a local parallel port.
2800
2801@option{path} specifies the path to the parallel port device. @option{path} is
2802required.
2803
2804@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name}
2805
2806@option{spicevmc} is only available when spice support is built in.
2807
2808@option{debug} debug level for spicevmc
2809
2810@option{name} name of spice channel to connect to
2811
2812Connect to a spice virtual machine channel, such as vdiport.
2813
2814@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name}
2815
2816@option{spiceport} is only available when spice support is built in.
2817
2818@option{debug} debug level for spicevmc
2819
2820@option{name} name of spice port to connect to
2821
2822Connect to a spice port, allowing a Spice client to handle the traffic
2823identified by a name (preferably a fqdn).
2824ETEXI
2825
2826STEXI
2827@end table
2828ETEXI
2829DEFHEADING()
2830
2831DEFHEADING(Bluetooth(R) options:)
2832STEXI
2833@table @option
2834ETEXI
2835
2836DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2837    "-bt hci,null    dumb bluetooth HCI - doesn't respond to commands\n" \
2838    "-bt hci,host[:id]\n" \
2839    "                use host's HCI with the given name\n" \
2840    "-bt hci[,vlan=n]\n" \
2841    "                emulate a standard HCI in virtual scatternet 'n'\n" \
2842    "-bt vhci[,vlan=n]\n" \
2843    "                add host computer to virtual scatternet 'n' using VHCI\n" \
2844    "-bt device:dev[,vlan=n]\n" \
2845    "                emulate a bluetooth device 'dev' in scatternet 'n'\n",
2846    QEMU_ARCH_ALL)
2847STEXI
2848@item -bt hci[...]
2849@findex -bt
2850Defines the function of the corresponding Bluetooth HCI.  -bt options
2851are matched with the HCIs present in the chosen machine type.  For
2852example when emulating a machine with only one HCI built into it, only
2853the first @code{-bt hci[...]} option is valid and defines the HCI's
2854logic.  The Transport Layer is decided by the machine type.  Currently
2855the machines @code{n800} and @code{n810} have one HCI and all other
2856machines have none.
2857
2858@anchor{bt-hcis}
2859The following three types are recognized:
2860
2861@table @option
2862@item -bt hci,null
2863(default) The corresponding Bluetooth HCI assumes no internal logic
2864and will not respond to any HCI commands or emit events.
2865
2866@item -bt hci,host[:@var{id}]
2867(@code{bluez} only) The corresponding HCI passes commands / events
2868to / from the physical HCI identified by the name @var{id} (default:
2869@code{hci0}) on the computer running QEMU.  Only available on @code{bluez}
2870capable systems like Linux.
2871
2872@item -bt hci[,vlan=@var{n}]
2873Add a virtual, standard HCI that will participate in the Bluetooth
2874scatternet @var{n} (default @code{0}).  Similarly to @option{-net}
2875VLANs, devices inside a bluetooth network @var{n} can only communicate
2876with other devices in the same network (scatternet).
2877@end table
2878
2879@item -bt vhci[,vlan=@var{n}]
2880(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2881to the host bluetooth stack instead of to the emulated target.  This
2882allows the host and target machines to participate in a common scatternet
2883and communicate.  Requires the Linux @code{vhci} driver installed.  Can
2884be used as following:
2885
2886@example
2887qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2888@end example
2889
2890@item -bt device:@var{dev}[,vlan=@var{n}]
2891Emulate a bluetooth device @var{dev} and place it in network @var{n}
2892(default @code{0}).  QEMU can only emulate one type of bluetooth devices
2893currently:
2894
2895@table @option
2896@item keyboard
2897Virtual wireless keyboard implementing the HIDP bluetooth profile.
2898@end table
2899ETEXI
2900
2901STEXI
2902@end table
2903ETEXI
2904DEFHEADING()
2905
2906#ifdef CONFIG_TPM
2907DEFHEADING(TPM device options:)
2908
2909DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2910    "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2911    "                use path to provide path to a character device; default is /dev/tpm0\n"
2912    "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2913    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
2914    "-tpmdev emulator,id=id,chardev=dev\n"
2915    "                configure the TPM device using chardev backend\n",
2916    QEMU_ARCH_ALL)
2917STEXI
2918
2919The general form of a TPM device option is:
2920@table @option
2921
2922@item -tpmdev @var{backend},id=@var{id}[,@var{options}]
2923@findex -tpmdev
2924
2925The specific backend type will determine the applicable options.
2926The @code{-tpmdev} option creates the TPM backend and requires a
2927@code{-device} option that specifies the TPM frontend interface model.
2928
2929Use @code{-tpmdev help} to print all available TPM backend types.
2930
2931@end table
2932
2933The available backends are:
2934
2935@table @option
2936
2937@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path}
2938
2939(Linux-host only) Enable access to the host's TPM using the passthrough
2940driver.
2941
2942@option{path} specifies the path to the host's TPM device, i.e., on
2943a Linux host this would be @code{/dev/tpm0}.
2944@option{path} is optional and by default @code{/dev/tpm0} is used.
2945
2946@option{cancel-path} specifies the path to the host TPM device's sysfs
2947entry allowing for cancellation of an ongoing TPM command.
2948@option{cancel-path} is optional and by default QEMU will search for the
2949sysfs entry to use.
2950
2951Some notes about using the host's TPM with the passthrough driver:
2952
2953The TPM device accessed by the passthrough driver must not be
2954used by any other application on the host.
2955
2956Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2957the VM's firmware (BIOS/UEFI) will not be able to initialize the
2958TPM again and may therefore not show a TPM-specific menu that would
2959otherwise allow the user to configure the TPM, e.g., allow the user to
2960enable/disable or activate/deactivate the TPM.
2961Further, if TPM ownership is released from within a VM then the host's TPM
2962will get disabled and deactivated. To enable and activate the
2963TPM again afterwards, the host has to be rebooted and the user is
2964required to enter the firmware's menu to enable and activate the TPM.
2965If the TPM is left disabled and/or deactivated most TPM commands will fail.
2966
2967To create a passthrough TPM use the following two options:
2968@example
2969-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2970@end example
2971Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2972@code{tpmdev=tpm0} in the device option.
2973
2974@item -tpmdev emulator,id=@var{id},chardev=@var{dev}
2975
2976(Linux-host only) Enable access to a TPM emulator using Unix domain socket based
2977chardev backend.
2978
2979@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
2980
2981To create a TPM emulator backend device with chardev socket backend:
2982@example
2983
2984-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
2985
2986@end example
2987
2988ETEXI
2989
2990STEXI
2991@end table
2992ETEXI
2993DEFHEADING()
2994
2995#endif
2996
2997DEFHEADING(Linux/Multiboot boot specific:)
2998STEXI
2999
3000When using these options, you can use a given Linux or Multiboot
3001kernel without installing it in the disk image. It can be useful
3002for easier testing of various kernels.
3003
3004@table @option
3005ETEXI
3006
3007DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
3008    "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
3009STEXI
3010@item -kernel @var{bzImage}
3011@findex -kernel
3012Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3013or in multiboot format.
3014ETEXI
3015
3016DEF("append", HAS_ARG, QEMU_OPTION_append, \
3017    "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
3018STEXI
3019@item -append @var{cmdline}
3020@findex -append
3021Use @var{cmdline} as kernel command line
3022ETEXI
3023
3024DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3025           "-initrd file    use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3026STEXI
3027@item -initrd @var{file}
3028@findex -initrd
3029Use @var{file} as initial ram disk.
3030
3031@item -initrd "@var{file1} arg=foo,@var{file2}"
3032
3033This syntax is only available with multiboot.
3034
3035Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3036first module.
3037ETEXI
3038
3039DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3040    "-dtb    file    use 'file' as device tree image\n", QEMU_ARCH_ALL)
3041STEXI
3042@item -dtb @var{file}
3043@findex -dtb
3044Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3045on boot.
3046ETEXI
3047
3048STEXI
3049@end table
3050ETEXI
3051DEFHEADING()
3052
3053DEFHEADING(Debug/Expert options:)
3054STEXI
3055@table @option
3056ETEXI
3057
3058DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3059    "-fw_cfg [name=]<name>,file=<file>\n"
3060    "                add named fw_cfg entry with contents from file\n"
3061    "-fw_cfg [name=]<name>,string=<str>\n"
3062    "                add named fw_cfg entry with contents from string\n",
3063    QEMU_ARCH_ALL)
3064STEXI
3065
3066@item -fw_cfg [name=]@var{name},file=@var{file}
3067@findex -fw_cfg
3068Add named fw_cfg entry with contents from file @var{file}.
3069
3070@item -fw_cfg [name=]@var{name},string=@var{str}
3071Add named fw_cfg entry with contents from string @var{str}.
3072
3073The terminating NUL character of the contents of @var{str} will not be
3074included as part of the fw_cfg item data. To insert contents with
3075embedded NUL characters, you have to use the @var{file} parameter.
3076
3077The fw_cfg entries are passed by QEMU through to the guest.
3078
3079Example:
3080@example
3081    -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3082@end example
3083creates an fw_cfg entry named opt/com.mycompany/blob with contents
3084from ./my_blob.bin.
3085
3086ETEXI
3087
3088DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3089    "-serial dev     redirect the serial port to char device 'dev'\n",
3090    QEMU_ARCH_ALL)
3091STEXI
3092@item -serial @var{dev}
3093@findex -serial
3094Redirect the virtual serial port to host character device
3095@var{dev}. The default device is @code{vc} in graphical mode and
3096@code{stdio} in non graphical mode.
3097
3098This option can be used several times to simulate up to 4 serial
3099ports.
3100
3101Use @code{-serial none} to disable all serial ports.
3102
3103Available character devices are:
3104@table @option
3105@item vc[:@var{W}x@var{H}]
3106Virtual console. Optionally, a width and height can be given in pixel with
3107@example
3108vc:800x600
3109@end example
3110It is also possible to specify width or height in characters:
3111@example
3112vc:80Cx24C
3113@end example
3114@item pty
3115[Linux only] Pseudo TTY (a new PTY is automatically allocated)
3116@item none
3117No device is allocated.
3118@item null
3119void device
3120@item chardev:@var{id}
3121Use a named character device defined with the @code{-chardev} option.
3122@item /dev/XXX
3123[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3124parameters are set according to the emulated ones.
3125@item /dev/parport@var{N}
3126[Linux only, parallel port only] Use host parallel port
3127@var{N}. Currently SPP and EPP parallel port features can be used.
3128@item file:@var{filename}
3129Write output to @var{filename}. No character can be read.
3130@item stdio
3131[Unix only] standard input/output
3132@item pipe:@var{filename}
3133name pipe @var{filename}
3134@item COM@var{n}
3135[Windows only] Use host serial port @var{n}
3136@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3137This implements UDP Net Console.
3138When @var{remote_host} or @var{src_ip} are not specified
3139they default to @code{0.0.0.0}.
3140When not using a specified @var{src_port} a random port is automatically chosen.
3141
3142If you just want a simple readonly console you can use @code{netcat} or
3143@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3144@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3145will appear in the netconsole session.
3146
3147If you plan to send characters back via netconsole or you want to stop
3148and start QEMU a lot of times, you should have QEMU use the same
3149source port each time by using something like @code{-serial
3150udp::4555@@:4556} to QEMU. Another approach is to use a patched
3151version of netcat which can listen to a TCP port and send and receive
3152characters via udp.  If you have a patched version of netcat which
3153activates telnet remote echo and single char transfer, then you can
3154use the following options to set up a netcat redirector to allow
3155telnet on port 5555 to access the QEMU port.
3156@table @code
3157@item QEMU Options:
3158-serial udp::4555@@:4556
3159@item netcat options:
3160-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3161@item telnet options:
3162localhost 5555
3163@end table
3164
3165@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3166The TCP Net Console has two modes of operation.  It can send the serial
3167I/O to a location or wait for a connection from a location.  By default
3168the TCP Net Console is sent to @var{host} at the @var{port}.  If you use
3169the @var{server} option QEMU will wait for a client socket application
3170to connect to the port before continuing, unless the @code{nowait}
3171option was specified.  The @code{nodelay} option disables the Nagle buffering
3172algorithm.  The @code{reconnect} option only applies if @var{noserver} is
3173set, if the connection goes down it will attempt to reconnect at the
3174given interval.  If @var{host} is omitted, 0.0.0.0 is assumed. Only
3175one TCP connection at a time is accepted. You can use @code{telnet} to
3176connect to the corresponding character device.
3177@table @code
3178@item Example to send tcp console to 192.168.0.2 port 4444
3179-serial tcp:192.168.0.2:4444
3180@item Example to listen and wait on port 4444 for connection
3181-serial tcp::4444,server
3182@item Example to not wait and listen on ip 192.168.0.100 port 4444
3183-serial tcp:192.168.0.100:4444,server,nowait
3184@end table
3185
3186@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3187The telnet protocol is used instead of raw tcp sockets.  The options
3188work the same as if you had specified @code{-serial tcp}.  The
3189difference is that the port acts like a telnet server or client using
3190telnet option negotiation.  This will also allow you to send the
3191MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3192sequence.  Typically in unix telnet you do it with Control-] and then
3193type "send break" followed by pressing the enter key.
3194
3195@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3196A unix domain socket is used instead of a tcp socket.  The option works the
3197same as if you had specified @code{-serial tcp} except the unix domain socket
3198@var{path} is used for connections.
3199
3200@item mon:@var{dev_string}
3201This is a special option to allow the monitor to be multiplexed onto
3202another serial port.  The monitor is accessed with key sequence of
3203@key{Control-a} and then pressing @key{c}.
3204@var{dev_string} should be any one of the serial devices specified
3205above.  An example to multiplex the monitor onto a telnet server
3206listening on port 4444 would be:
3207@table @code
3208@item -serial mon:telnet::4444,server,nowait
3209@end table
3210When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3211QEMU any more but will be passed to the guest instead.
3212
3213@item braille
3214Braille device.  This will use BrlAPI to display the braille output on a real
3215or fake device.
3216
3217@item msmouse
3218Three button serial mouse. Configure the guest to use Microsoft protocol.
3219@end table
3220ETEXI
3221
3222DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3223    "-parallel dev   redirect the parallel port to char device 'dev'\n",
3224    QEMU_ARCH_ALL)
3225STEXI
3226@item -parallel @var{dev}
3227@findex -parallel
3228Redirect the virtual parallel port to host device @var{dev} (same
3229devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3230be used to use hardware devices connected on the corresponding host
3231parallel port.
3232
3233This option can be used several times to simulate up to 3 parallel
3234ports.
3235
3236Use @code{-parallel none} to disable all parallel ports.
3237ETEXI
3238
3239DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3240    "-monitor dev    redirect the monitor to char device 'dev'\n",
3241    QEMU_ARCH_ALL)
3242STEXI
3243@item -monitor @var{dev}
3244@findex -monitor
3245Redirect the monitor to host device @var{dev} (same devices as the
3246serial port).
3247The default device is @code{vc} in graphical mode and @code{stdio} in
3248non graphical mode.
3249Use @code{-monitor none} to disable the default monitor.
3250ETEXI
3251DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3252    "-qmp dev        like -monitor but opens in 'control' mode\n",
3253    QEMU_ARCH_ALL)
3254STEXI
3255@item -qmp @var{dev}
3256@findex -qmp
3257Like -monitor but opens in 'control' mode.
3258ETEXI
3259DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3260    "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3261    QEMU_ARCH_ALL)
3262STEXI
3263@item -qmp-pretty @var{dev}
3264@findex -qmp-pretty
3265Like -qmp but uses pretty JSON formatting.
3266ETEXI
3267
3268DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3269    "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
3270STEXI
3271@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]
3272@findex -mon
3273Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing
3274easing human reading and debugging.
3275ETEXI
3276
3277DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3278    "-debugcon dev   redirect the debug console to char device 'dev'\n",
3279    QEMU_ARCH_ALL)
3280STEXI
3281@item -debugcon @var{dev}
3282@findex -debugcon
3283Redirect the debug console to host device @var{dev} (same devices as the
3284serial port).  The debug console is an I/O port which is typically port
32850xe9; writing to that I/O port sends output to this device.
3286The default device is @code{vc} in graphical mode and @code{stdio} in
3287non graphical mode.
3288ETEXI
3289
3290DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3291    "-pidfile file   write PID to 'file'\n", QEMU_ARCH_ALL)
3292STEXI
3293@item -pidfile @var{file}
3294@findex -pidfile
3295Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3296from a script.
3297ETEXI
3298
3299DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3300    "-singlestep     always run in singlestep mode\n", QEMU_ARCH_ALL)
3301STEXI
3302@item -singlestep
3303@findex -singlestep
3304Run the emulation in single step mode.
3305ETEXI
3306
3307DEF("S", 0, QEMU_OPTION_S, \
3308    "-S              freeze CPU at startup (use 'c' to start execution)\n",
3309    QEMU_ARCH_ALL)
3310STEXI
3311@item -S
3312@findex -S
3313Do not start CPU at startup (you must type 'c' in the monitor).
3314ETEXI
3315
3316DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3317    "-realtime [mlock=on|off]\n"
3318    "                run qemu with realtime features\n"
3319    "                mlock=on|off controls mlock support (default: on)\n",
3320    QEMU_ARCH_ALL)
3321STEXI
3322@item -realtime mlock=on|off
3323@findex -realtime
3324Run qemu with realtime features.
3325mlocking qemu and guest memory can be enabled via @option{mlock=on}
3326(enabled by default).
3327ETEXI
3328
3329DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3330    "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3331STEXI
3332@item -gdb @var{dev}
3333@findex -gdb
3334Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3335connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3336stdio are reasonable use case. The latter is allowing to start QEMU from
3337within gdb and establish the connection via a pipe:
3338@example
3339(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3340@end example
3341ETEXI
3342
3343DEF("s", 0, QEMU_OPTION_s, \
3344    "-s              shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3345    QEMU_ARCH_ALL)
3346STEXI
3347@item -s
3348@findex -s
3349Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3350(@pxref{gdb_usage}).
3351ETEXI
3352
3353DEF("d", HAS_ARG, QEMU_OPTION_d, \
3354    "-d item1,...    enable logging of specified items (use '-d help' for a list of log items)\n",
3355    QEMU_ARCH_ALL)
3356STEXI
3357@item -d @var{item1}[,...]
3358@findex -d
3359Enable logging of specified items. Use '-d help' for a list of log items.
3360ETEXI
3361
3362DEF("D", HAS_ARG, QEMU_OPTION_D, \
3363    "-D logfile      output log to logfile (default stderr)\n",
3364    QEMU_ARCH_ALL)
3365STEXI
3366@item -D @var{logfile}
3367@findex -D
3368Output log in @var{logfile} instead of to stderr
3369ETEXI
3370
3371DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3372    "-dfilter range,..  filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3373    QEMU_ARCH_ALL)
3374STEXI
3375@item -dfilter @var{range1}[,...]
3376@findex -dfilter
3377Filter debug output to that relevant to a range of target addresses. The filter
3378spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3379@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3380addresses and sizes required. For example:
3381@example
3382    -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3383@end example
3384Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3385the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3386block starting at 0xffffffc00005f000.
3387ETEXI
3388
3389DEF("L", HAS_ARG, QEMU_OPTION_L, \
3390    "-L path         set the directory for the BIOS, VGA BIOS and keymaps\n",
3391    QEMU_ARCH_ALL)
3392STEXI
3393@item -L  @var{path}
3394@findex -L
3395Set the directory for the BIOS, VGA BIOS and keymaps.
3396
3397To list all the data directories, use @code{-L help}.
3398ETEXI
3399
3400DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3401    "-bios file      set the filename for the BIOS\n", QEMU_ARCH_ALL)
3402STEXI
3403@item -bios @var{file}
3404@findex -bios
3405Set the filename for the BIOS.
3406ETEXI
3407
3408DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3409    "-enable-kvm     enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3410STEXI
3411@item -enable-kvm
3412@findex -enable-kvm
3413Enable KVM full virtualization support. This option is only available
3414if KVM support is enabled when compiling.
3415ETEXI
3416
3417DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3418    "-enable-hax     enable HAX virtualization support\n", QEMU_ARCH_I386)
3419STEXI
3420@item -enable-hax
3421@findex -enable-hax
3422Enable HAX (Hardware-based Acceleration eXecution) support. This option
3423is only available if HAX support is enabled when compiling. HAX is only
3424applicable to MAC and Windows platform, and thus does not conflict with
3425KVM.
3426ETEXI
3427
3428DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3429    "-xen-domid id   specify xen guest domain id\n", QEMU_ARCH_ALL)
3430DEF("xen-create", 0, QEMU_OPTION_xen_create,
3431    "-xen-create     create domain using xen hypercalls, bypassing xend\n"
3432    "                warning: should not be used when xend is in use\n",
3433    QEMU_ARCH_ALL)
3434DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3435    "-xen-attach     attach to existing xen domain\n"
3436    "                xend will use this when starting QEMU\n",
3437    QEMU_ARCH_ALL)
3438DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3439    "-xen-domid-restrict     restrict set of available xen operations\n"
3440    "                        to specified domain id. (Does not affect\n"
3441    "                        xenpv machine type).\n",
3442    QEMU_ARCH_ALL)
3443STEXI
3444@item -xen-domid @var{id}
3445@findex -xen-domid
3446Specify xen guest domain @var{id} (XEN only).
3447@item -xen-create
3448@findex -xen-create
3449Create domain using xen hypercalls, bypassing xend.
3450Warning: should not be used when xend is in use (XEN only).
3451@item -xen-attach
3452@findex -xen-attach
3453Attach to existing xen domain.
3454xend will use this when starting QEMU (XEN only).
3455@findex -xen-domid-restrict
3456Restrict set of available xen operations to specified domain id (XEN only).
3457ETEXI
3458
3459DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3460    "-no-reboot      exit instead of rebooting\n", QEMU_ARCH_ALL)
3461STEXI
3462@item -no-reboot
3463@findex -no-reboot
3464Exit instead of rebooting.
3465ETEXI
3466
3467DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3468    "-no-shutdown    stop before shutdown\n", QEMU_ARCH_ALL)
3469STEXI
3470@item -no-shutdown
3471@findex -no-shutdown
3472Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3473This allows for instance switching to monitor to commit changes to the
3474disk image.
3475ETEXI
3476
3477DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3478    "-loadvm [tag|id]\n" \
3479    "                start right away with a saved state (loadvm in monitor)\n",
3480    QEMU_ARCH_ALL)
3481STEXI
3482@item -loadvm @var{file}
3483@findex -loadvm
3484Start right away with a saved state (@code{loadvm} in monitor)
3485ETEXI
3486
3487#ifndef _WIN32
3488DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3489    "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3490#endif
3491STEXI
3492@item -daemonize
3493@findex -daemonize
3494Daemonize the QEMU process after initialization.  QEMU will not detach from
3495standard IO until it is ready to receive connections on any of its devices.
3496This option is a useful way for external programs to launch QEMU without having
3497to cope with initialization race conditions.
3498ETEXI
3499
3500DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3501    "-option-rom rom load a file, rom, into the option ROM space\n",
3502    QEMU_ARCH_ALL)
3503STEXI
3504@item -option-rom @var{file}
3505@findex -option-rom
3506Load the contents of @var{file} as an option ROM.
3507This option is useful to load things like EtherBoot.
3508ETEXI
3509
3510HXCOMM Silently ignored for compatibility
3511DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3512
3513HXCOMM Options deprecated by -rtc
3514DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3515DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3516
3517DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3518    "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3519    "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3520    QEMU_ARCH_ALL)
3521
3522STEXI
3523
3524@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3525@findex -rtc
3526Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3527UTC or local time, respectively. @code{localtime} is required for correct date in
3528MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3529format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3530
3531By default the RTC is driven by the host system time. This allows using of the
3532RTC as accurate reference clock inside the guest, specifically if the host
3533time is smoothly following an accurate external reference clock, e.g. via NTP.
3534If you want to isolate the guest time from the host, you can set @option{clock}
3535to @code{rt} instead.  To even prevent it from progressing during suspension,
3536you can set it to @code{vm}.
3537
3538Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3539specifically with Windows' ACPI HAL. This option will try to figure out how
3540many timer interrupts were not processed by the Windows guest and will
3541re-inject them.
3542ETEXI
3543
3544DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3545    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3546    "                enable virtual instruction counter with 2^N clock ticks per\n" \
3547    "                instruction, enable aligning the host and virtual clocks\n" \
3548    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3549STEXI
3550@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3551@findex -icount
3552Enable virtual instruction counter.  The virtual cpu will execute one
3553instruction every 2^@var{N} ns of virtual time.  If @code{auto} is specified
3554then the virtual cpu speed will be automatically adjusted to keep virtual
3555time within a few seconds of real time.
3556
3557When the virtual cpu is sleeping, the virtual time will advance at default
3558speed unless @option{sleep=on|off} is specified.
3559With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3560instantly whenever the virtual cpu goes to sleep mode and will not advance
3561if no timer is enabled. This behavior give deterministic execution times from
3562the guest point of view.
3563
3564Note that while this option can give deterministic behavior, it does not
3565provide cycle accurate emulation.  Modern CPUs contain superscalar out of
3566order cores with complex cache hierarchies.  The number of instructions
3567executed often has little or no correlation with actual performance.
3568
3569@option{align=on} will activate the delay algorithm which will try
3570to synchronise the host clock and the virtual clock. The goal is to
3571have a guest running at the real frequency imposed by the shift option.
3572Whenever the guest clock is behind the host clock and if
3573@option{align=on} is specified then we print a message to the user
3574to inform about the delay.
3575Currently this option does not work when @option{shift} is @code{auto}.
3576Note: The sync algorithm will work for those shift values for which
3577the guest clock runs ahead of the host clock. Typically this happens
3578when the shift value is high (how high depends on the host machine).
3579
3580When @option{rr} option is specified deterministic record/replay is enabled.
3581Replay log is written into @var{filename} file in record mode and
3582read from this file in replay mode.
3583
3584Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3585at the start of execution recording. In replay mode this option is used
3586to load the initial VM state.
3587ETEXI
3588
3589DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3590    "-watchdog model\n" \
3591    "                enable virtual hardware watchdog [default=none]\n",
3592    QEMU_ARCH_ALL)
3593STEXI
3594@item -watchdog @var{model}
3595@findex -watchdog
3596Create a virtual hardware watchdog device.  Once enabled (by a guest
3597action), the watchdog must be periodically polled by an agent inside
3598the guest or else the guest will be restarted. Choose a model for
3599which your guest has drivers.
3600
3601The @var{model} is the model of hardware watchdog to emulate. Use
3602@code{-watchdog help} to list available hardware models. Only one
3603watchdog can be enabled for a guest.
3604
3605The following models may be available:
3606@table @option
3607@item ib700
3608iBASE 700 is a very simple ISA watchdog with a single timer.
3609@item i6300esb
3610Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3611dual-timer watchdog.
3612@item diag288
3613A virtual watchdog for s390x backed by the diagnose 288 hypercall
3614(currently KVM only).
3615@end table
3616ETEXI
3617
3618DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3619    "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
3620    "                action when watchdog fires [default=reset]\n",
3621    QEMU_ARCH_ALL)
3622STEXI
3623@item -watchdog-action @var{action}
3624@findex -watchdog-action
3625
3626The @var{action} controls what QEMU will do when the watchdog timer
3627expires.
3628The default is
3629@code{reset} (forcefully reset the guest).
3630Other possible actions are:
3631@code{shutdown} (attempt to gracefully shutdown the guest),
3632@code{poweroff} (forcefully poweroff the guest),
3633@code{inject-nmi} (inject a NMI into the guest),
3634@code{pause} (pause the guest),
3635@code{debug} (print a debug message and continue), or
3636@code{none} (do nothing).
3637
3638Note that the @code{shutdown} action requires that the guest responds
3639to ACPI signals, which it may not be able to do in the sort of
3640situations where the watchdog would have expired, and thus
3641@code{-watchdog-action shutdown} is not recommended for production use.
3642
3643Examples:
3644
3645@table @code
3646@item -watchdog i6300esb -watchdog-action pause
3647@itemx -watchdog ib700
3648@end table
3649ETEXI
3650
3651DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3652    "-echr chr       set terminal escape character instead of ctrl-a\n",
3653    QEMU_ARCH_ALL)
3654STEXI
3655
3656@item -echr @var{numeric_ascii_value}
3657@findex -echr
3658Change the escape character used for switching to the monitor when using
3659monitor and serial sharing.  The default is @code{0x01} when using the
3660@code{-nographic} option.  @code{0x01} is equal to pressing
3661@code{Control-a}.  You can select a different character from the ascii
3662control keys where 1 through 26 map to Control-a through Control-z.  For
3663instance you could use the either of the following to change the escape
3664character to Control-t.
3665@table @code
3666@item -echr 0x14
3667@itemx -echr 20
3668@end table
3669ETEXI
3670
3671DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3672    "-virtioconsole c\n" \
3673    "                set virtio console\n", QEMU_ARCH_ALL)
3674STEXI
3675@item -virtioconsole @var{c}
3676@findex -virtioconsole
3677Set virtio console.
3678
3679This option is maintained for backward compatibility.
3680
3681Please use @code{-device virtconsole} for the new way of invocation.
3682ETEXI
3683
3684DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3685    "-show-cursor    show cursor\n", QEMU_ARCH_ALL)
3686STEXI
3687@item -show-cursor
3688@findex -show-cursor
3689Show cursor.
3690ETEXI
3691
3692DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3693    "-tb-size n      set TB size\n", QEMU_ARCH_ALL)
3694STEXI
3695@item -tb-size @var{n}
3696@findex -tb-size
3697Set TB size.
3698ETEXI
3699
3700DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3701    "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3702    "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3703    "-incoming unix:socketpath\n" \
3704    "                prepare for incoming migration, listen on\n" \
3705    "                specified protocol and socket address\n" \
3706    "-incoming fd:fd\n" \
3707    "-incoming exec:cmdline\n" \
3708    "                accept incoming migration on given file descriptor\n" \
3709    "                or from given external command\n" \
3710    "-incoming defer\n" \
3711    "                wait for the URI to be specified via migrate_incoming\n",
3712    QEMU_ARCH_ALL)
3713STEXI
3714@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3715@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3716@findex -incoming
3717Prepare for incoming migration, listen on a given tcp port.
3718
3719@item -incoming unix:@var{socketpath}
3720Prepare for incoming migration, listen on a given unix socket.
3721
3722@item -incoming fd:@var{fd}
3723Accept incoming migration from a given filedescriptor.
3724
3725@item -incoming exec:@var{cmdline}
3726Accept incoming migration as an output from specified external command.
3727
3728@item -incoming defer
3729Wait for the URI to be specified via migrate_incoming.  The monitor can
3730be used to change settings (such as migration parameters) prior to issuing
3731the migrate_incoming to allow the migration to begin.
3732ETEXI
3733
3734DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3735    "-only-migratable     allow only migratable devices\n", QEMU_ARCH_ALL)
3736STEXI
3737@item -only-migratable
3738@findex -only-migratable
3739Only allow migratable devices. Devices will not be allowed to enter an
3740unmigratable state.
3741ETEXI
3742
3743DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3744    "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
3745STEXI
3746@item -nodefaults
3747@findex -nodefaults
3748Don't create default devices. Normally, QEMU sets the default devices like serial
3749port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3750CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3751default devices.
3752ETEXI
3753
3754#ifndef _WIN32
3755DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3756    "-chroot dir     chroot to dir just before starting the VM\n",
3757    QEMU_ARCH_ALL)
3758#endif
3759STEXI
3760@item -chroot @var{dir}
3761@findex -chroot
3762Immediately before starting guest execution, chroot to the specified
3763directory.  Especially useful in combination with -runas.
3764ETEXI
3765
3766#ifndef _WIN32
3767DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3768    "-runas user     change to user id user just before starting the VM\n",
3769    QEMU_ARCH_ALL)
3770#endif
3771STEXI
3772@item -runas @var{user}
3773@findex -runas
3774Immediately before starting guest execution, drop root privileges, switching
3775to the specified user.
3776ETEXI
3777
3778DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3779    "-prom-env variable=value\n"
3780    "                set OpenBIOS nvram variables\n",
3781    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3782STEXI
3783@item -prom-env @var{variable}=@var{value}
3784@findex -prom-env
3785Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3786ETEXI
3787DEF("semihosting", 0, QEMU_OPTION_semihosting,
3788    "-semihosting    semihosting mode\n",
3789    QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3790    QEMU_ARCH_MIPS)
3791STEXI
3792@item -semihosting
3793@findex -semihosting
3794Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3795ETEXI
3796DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3797    "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3798    "                semihosting configuration\n",
3799QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3800QEMU_ARCH_MIPS)
3801STEXI
3802@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3803@findex -semihosting-config
3804Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3805@table @option
3806@item target=@code{native|gdb|auto}
3807Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3808or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3809during debug sessions and @code{native} otherwise.
3810@item arg=@var{str1},arg=@var{str2},...
3811Allows the user to pass input arguments, and can be used multiple times to build
3812up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3813command line is still supported for backward compatibility. If both the
3814@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3815specified, the former is passed to semihosting as it always takes precedence.
3816@end table
3817ETEXI
3818DEF("old-param", 0, QEMU_OPTION_old_param,
3819    "-old-param      old param mode\n", QEMU_ARCH_ARM)
3820STEXI
3821@item -old-param
3822@findex -old-param (ARM)
3823Old param mode (ARM only).
3824ETEXI
3825
3826DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3827    "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
3828    "          [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
3829    "                Enable seccomp mode 2 system call filter (default 'off').\n" \
3830    "                use 'obsolete' to allow obsolete system calls that are provided\n" \
3831    "                    by the kernel, but typically no longer used by modern\n" \
3832    "                    C library implementations.\n" \
3833    "                use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
3834    "                    its privileges by blacklisting all set*uid|gid system calls.\n" \
3835    "                    The value 'children' will deny set*uid|gid system calls for\n" \
3836    "                    main QEMU process but will allow forks and execves to run unprivileged\n" \
3837    "                use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
3838    "                     blacklisting *fork and execve\n" \
3839    "                use 'resourcecontrol' to disable process affinity and schedular priority\n",
3840    QEMU_ARCH_ALL)
3841STEXI
3842@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
3843@findex -sandbox
3844Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3845disable it.  The default is 'off'.
3846@table @option
3847@item obsolete=@var{string}
3848Enable Obsolete system calls
3849@item elevateprivileges=@var{string}
3850Disable set*uid|gid system calls
3851@item spawn=@var{string}
3852Disable *fork and execve
3853@item resourcecontrol=@var{string}
3854Disable process affinity and schedular priority
3855@end table
3856ETEXI
3857
3858DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3859    "-readconfig <file>\n", QEMU_ARCH_ALL)
3860STEXI
3861@item -readconfig @var{file}
3862@findex -readconfig
3863Read device configuration from @var{file}. This approach is useful when you want to spawn
3864QEMU process with many command line options but you don't want to exceed the command line
3865character limit.
3866ETEXI
3867DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3868    "-writeconfig <file>\n"
3869    "                read/write config file\n", QEMU_ARCH_ALL)
3870STEXI
3871@item -writeconfig @var{file}
3872@findex -writeconfig
3873Write device configuration to @var{file}. The @var{file} can be either filename to save
3874command line and device configuration into file or dash @code{-}) character to print the
3875output to stdout. This can be later used as input file for @code{-readconfig} option.
3876ETEXI
3877HXCOMM Deprecated, same as -no-user-config
3878DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
3879DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3880    "-no-user-config\n"
3881    "                do not load default user-provided config files at startup\n",
3882    QEMU_ARCH_ALL)
3883STEXI
3884@item -no-user-config
3885@findex -no-user-config
3886The @code{-no-user-config} option makes QEMU not load any of the user-provided
3887config files on @var{sysconfdir}.
3888ETEXI
3889DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3890    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
3891    "                specify tracing options\n",
3892    QEMU_ARCH_ALL)
3893STEXI
3894HXCOMM This line is not accurate, as some sub-options are backend-specific but
3895HXCOMM HX does not support conditional compilation of text.
3896@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
3897@findex -trace
3898@include qemu-option-trace.texi
3899ETEXI
3900
3901HXCOMM Internal use
3902DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3903DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3904
3905#ifdef __linux__
3906DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3907    "-enable-fips    enable FIPS 140-2 compliance\n",
3908    QEMU_ARCH_ALL)
3909#endif
3910STEXI
3911@item -enable-fips
3912@findex -enable-fips
3913Enable FIPS 140-2 compliance mode.
3914ETEXI
3915
3916HXCOMM Deprecated by -machine accel=tcg property
3917DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3918
3919HXCOMM Deprecated by kvm-pit driver properties
3920DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3921    "", QEMU_ARCH_I386)
3922
3923HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3924DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3925
3926HXCOMM Deprecated (ignored)
3927DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3928
3929DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3930    "-msg timestamp[=on|off]\n"
3931    "                change the format of messages\n"
3932    "                on|off controls leading timestamps (default:on)\n",
3933    QEMU_ARCH_ALL)
3934STEXI
3935@item -msg timestamp[=on|off]
3936@findex -msg
3937prepend a timestamp to each log message.(default:on)
3938ETEXI
3939
3940DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3941    "-dump-vmstate <file>\n"
3942    "                Output vmstate information in JSON format to file.\n"
3943    "                Use the scripts/vmstate-static-checker.py file to\n"
3944    "                check for possible regressions in migration code\n"
3945    "                by comparing two such vmstate dumps.\n",
3946    QEMU_ARCH_ALL)
3947STEXI
3948@item -dump-vmstate @var{file}
3949@findex -dump-vmstate
3950Dump json-encoded vmstate information for current machine type to file
3951in @var{file}
3952ETEXI
3953
3954STEXI
3955@end table
3956ETEXI
3957DEFHEADING()
3958
3959DEFHEADING(Generic object creation:)
3960STEXI
3961@table @option
3962ETEXI
3963
3964DEF("object", HAS_ARG, QEMU_OPTION_object,
3965    "-object TYPENAME[,PROP1=VALUE1,...]\n"
3966    "                create a new object of type TYPENAME setting properties\n"
3967    "                in the order they are specified.  Note that the 'id'\n"
3968    "                property must be set.  These objects are placed in the\n"
3969    "                '/objects' path.\n",
3970    QEMU_ARCH_ALL)
3971STEXI
3972@item -object @var{typename}[,@var{prop1}=@var{value1},...]
3973@findex -object
3974Create a new object of type @var{typename} setting properties
3975in the order they are specified.  Note that the 'id'
3976property must be set.  These objects are placed in the
3977'/objects' path.
3978
3979@table @option
3980
3981@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},align=@var{align}
3982
3983Creates a memory file backend object, which can be used to back
3984the guest RAM with huge pages.
3985
3986The @option{id} parameter is a unique ID that will be used to reference this
3987memory region when configuring the @option{-numa} argument.
3988
3989The @option{size} option provides the size of the memory region, and accepts
3990common suffixes, eg @option{500M}.
3991
3992The @option{mem-path} provides the path to either a shared memory or huge page
3993filesystem mount.
3994
3995The @option{share} boolean option determines whether the memory
3996region is marked as private to QEMU, or shared. The latter allows
3997a co-operating external process to access the QEMU memory region.
3998
3999The @option{share} is also required for pvrdma devices due to
4000limitations in the RDMA API provided by Linux.
4001
4002Setting share=on might affect the ability to configure NUMA
4003bindings for the memory backend under some circumstances, see
4004Documentation/vm/numa_memory_policy.txt on the Linux kernel
4005source tree for additional details.
4006
4007Setting the @option{discard-data} boolean option to @var{on}
4008indicates that file contents can be destroyed when QEMU exits,
4009to avoid unnecessarily flushing data to the backing file.  Note
4010that @option{discard-data} is only an optimization, and QEMU
4011might not discard file contents if it aborts unexpectedly or is
4012terminated using SIGKILL.
4013
4014The @option{merge} boolean option enables memory merge, also known as
4015MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for
4016memory deduplication.
4017
4018Setting the @option{dump} boolean option to @var{off} excludes the memory from
4019core dumps. This feature is also known as MADV_DONTDUMP.
4020
4021The @option{prealloc} boolean option enables memory preallocation.
4022
4023The @option{host-nodes} option binds the memory range to a list of NUMA host
4024nodes.
4025
4026The @option{policy} option sets the NUMA policy to one of the following values:
4027
4028@table @option
4029@item @var{default}
4030default host policy
4031
4032@item @var{preferred}
4033prefer the given host node list for allocation
4034
4035@item @var{bind}
4036restrict memory allocation to the given host node list
4037
4038@item @var{interleave}
4039interleave memory allocations across the given host node list
4040@end table
4041
4042The @option{align} option specifies the base address alignment when
4043QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg
4044@option{2M}. Some backend store specified by @option{mem-path}
4045requires an alignment different than the default one used by QEMU, eg
4046the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4047such cases, users can specify the required alignment via this option.
4048
4049@item -object memory-backend-ram,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave}
4050
4051Creates a memory backend object, which can be used to back the guest RAM.
4052Memory backend objects offer more control than the @option{-m} option that is
4053traditionally used to define guest RAM. Please refer to
4054@option{memory-backend-file} for a description of the options.
4055
4056@item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size}
4057
4058Creates an anonymous memory file backend object, which allows QEMU to
4059share the memory with an external process (e.g. when using
4060vhost-user). The memory is allocated with memfd and optional
4061sealing. (Linux only)
4062
4063The @option{seal} option creates a sealed-file, that will block
4064further resizing the memory ('on' by default).
4065
4066The @option{hugetlb} option specify the file to be created resides in
4067the hugetlbfs filesystem (since Linux 4.14).  Used in conjunction with
4068the @option{hugetlb} option, the @option{hugetlbsize} option specify
4069the hugetlb page size on systems that support multiple hugetlb page
4070sizes (it must be a power of 2 value supported by the system).
4071
4072In some versions of Linux, the @option{hugetlb} option is incompatible
4073with the @option{seal} option (requires at least Linux 4.16).
4074
4075Please refer to @option{memory-backend-file} for a description of the
4076other options.
4077
4078@item -object rng-random,id=@var{id},filename=@var{/dev/random}
4079
4080Creates a random number generator backend which obtains entropy from
4081a device on the host. The @option{id} parameter is a unique ID that
4082will be used to reference this entropy backend from the @option{virtio-rng}
4083device. The @option{filename} parameter specifies which file to obtain
4084entropy from and if omitted defaults to @option{/dev/random}.
4085
4086@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4087
4088Creates a random number generator backend which obtains entropy from
4089an external daemon running on the host. The @option{id} parameter is
4090a unique ID that will be used to reference this entropy backend from
4091the @option{virtio-rng} device. The @option{chardev} parameter is
4092the unique ID of a character device backend that provides the connection
4093to the RNG daemon.
4094
4095@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4096
4097Creates a TLS anonymous credentials object, which can be used to provide
4098TLS support on network backends. The @option{id} parameter is a unique
4099ID which network backends will use to access the credentials. The
4100@option{endpoint} is either @option{server} or @option{client} depending
4101on whether the QEMU network backend that uses the credentials will be
4102acting as a client or as a server. If @option{verify-peer} is enabled
4103(the default) then once the handshake is completed, the peer credentials
4104will be verified, though this is a no-op for anonymous credentials.
4105
4106The @var{dir} parameter tells QEMU where to find the credential
4107files. For server endpoints, this directory may contain a file
4108@var{dh-params.pem} providing diffie-hellman parameters to use
4109for the TLS server. If the file is missing, QEMU will generate
4110a set of DH parameters at startup. This is a computationally
4111expensive operation that consumes random pool entropy, so it is
4112recommended that a persistent set of parameters be generated
4113upfront and saved.
4114
4115@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},priority=@var{priority},verify-peer=@var{on|off},passwordid=@var{id}
4116
4117Creates a TLS anonymous credentials object, which can be used to provide
4118TLS support on network backends. The @option{id} parameter is a unique
4119ID which network backends will use to access the credentials. The
4120@option{endpoint} is either @option{server} or @option{client} depending
4121on whether the QEMU network backend that uses the credentials will be
4122acting as a client or as a server. If @option{verify-peer} is enabled
4123(the default) then once the handshake is completed, the peer credentials
4124will be verified. With x509 certificates, this implies that the clients
4125must be provided with valid client certificates too.
4126
4127The @var{dir} parameter tells QEMU where to find the credential
4128files. For server endpoints, this directory may contain a file
4129@var{dh-params.pem} providing diffie-hellman parameters to use
4130for the TLS server. If the file is missing, QEMU will generate
4131a set of DH parameters at startup. This is a computationally
4132expensive operation that consumes random pool entropy, so it is
4133recommended that a persistent set of parameters be generated
4134upfront and saved.
4135
4136For x509 certificate credentials the directory will contain further files
4137providing the x509 certificates. The certificates must be stored
4138in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4139@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4140@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4141
4142For the @var{server-key.pem} and @var{client-key.pem} files which
4143contain sensitive private keys, it is possible to use an encrypted
4144version by providing the @var{passwordid} parameter. This provides
4145the ID of a previously created @code{secret} object containing the
4146password for decryption.
4147
4148The @var{priority} parameter allows to override the global default
4149priority used by gnutls. This can be useful if the system administrator
4150needs to use a weaker set of crypto priorities for QEMU without
4151potentially forcing the weakness onto all applications. Or conversely
4152if one wants wants a stronger default for QEMU than for all other
4153applications, they can do this through this parameter. Its format is
4154a gnutls priority string as described at
4155@url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
4156
4157@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4158
4159Interval @var{t} can't be 0, this filter batches the packet delivery: all
4160packets arriving in a given interval on netdev @var{netdevid} are delayed
4161until the end of the interval. Interval is in microseconds.
4162@option{status} is optional that indicate whether the netfilter is
4163on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4164
4165queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4166
4167@option{all}: the filter is attached both to the receive and the transmit
4168              queue of the netdev (default).
4169
4170@option{rx}: the filter is attached to the receive queue of the netdev,
4171             where it will receive packets sent to the netdev.
4172
4173@option{tx}: the filter is attached to the transmit queue of the netdev,
4174             where it will receive packets sent by the netdev.
4175
4176@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4177
4178filter-mirror on netdev @var{netdevid},mirror net packet to chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will mirror packet with vnet_hdr_len.
4179
4180@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4181
4182filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4183@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4184filter-redirector will redirect packet with vnet_hdr_len.
4185Create a filter-redirector we need to differ outdev id from indev id, id can not
4186be the same. we can just use indev or outdev, but at least one of indev or outdev
4187need to be specified.
4188
4189@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4190
4191Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4192secondary from primary to keep secondary tcp connection,and rewrite
4193tcp packet to primary from secondary make tcp packet can be handled by
4194client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4195
4196usage:
4197colo secondary:
4198-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4199-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4200-object filter-rewriter,id=rew0,netdev=hn0,queue=all
4201
4202@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4203
4204Dump the network traffic on netdev @var{dev} to the file specified by
4205@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4206The file format is libpcap, so it can be analyzed with tools such as tcpdump
4207or Wireshark.
4208
4209@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4210
4211Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4212secondary packet. If the packets are same, we will output primary
4213packet to outdev@var{chardevid}, else we will notify colo-frame
4214do checkpoint and send primary packet to outdev@var{chardevid}.
4215if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4216
4217we must use it with the help of filter-mirror and filter-redirector.
4218
4219@example
4220
4221primary:
4222-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4223-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4224-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4225-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4226-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4227-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4228-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4229-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4230-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4231-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4232-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4233-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4234
4235secondary:
4236-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4237-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4238-chardev socket,id=red0,host=3.3.3.3,port=9003
4239-chardev socket,id=red1,host=3.3.3.3,port=9004
4240-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4241-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4242
4243@end example
4244
4245If you want to know the detail of above command line, you can read
4246the colo-compare git log.
4247
4248@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4249
4250Creates a cryptodev backend which executes crypto opreation from
4251the QEMU cipher APIS. The @var{id} parameter is
4252a unique ID that will be used to reference this cryptodev backend from
4253the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4254which specify the queue number of cryptodev backend, the default of
4255@var{queues} is 1.
4256
4257@example
4258
4259 # qemu-system-x86_64 \
4260   [...] \
4261       -object cryptodev-backend-builtin,id=cryptodev0 \
4262       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4263   [...]
4264@end example
4265
4266@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}]
4267
4268Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}.
4269The @var{id} parameter is a unique ID that will be used to reference this
4270cryptodev backend from the @option{virtio-crypto} device.
4271The chardev should be a unix domain socket backed one. The vhost-user uses
4272a specifically defined protocol to pass vhost ioctl replacement messages
4273to an application on the other end of the socket.
4274The @var{queues} parameter is optional, which specify the queue number
4275of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1.
4276
4277@example
4278
4279 # qemu-system-x86_64 \
4280   [...] \
4281       -chardev socket,id=chardev0,path=/path/to/socket \
4282       -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
4283       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4284   [...]
4285@end example
4286
4287@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4288@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4289
4290Defines a secret to store a password, encryption key, or some other sensitive
4291data. The sensitive data can either be passed directly via the @var{data}
4292parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4293parameter is insecure unless the sensitive data is encrypted.
4294
4295The sensitive data can be provided in raw format (the default), or base64.
4296When encoded as JSON, the raw format only supports valid UTF-8 characters,
4297so base64 is recommended for sending binary data. QEMU will convert from
4298which ever format is provided to the format it needs internally. eg, an
4299RBD password can be provided in raw format, even though it will be base64
4300encoded when passed onto the RBD sever.
4301
4302For added protection, it is possible to encrypt the data associated with
4303a secret using the AES-256-CBC cipher. Use of encryption is indicated
4304by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4305parameter provides the ID of a previously defined secret that contains
4306the AES-256 decryption key. This key should be 32-bytes long and be
4307base64 encoded. The @var{iv} parameter provides the random initialization
4308vector used for encryption of this particular secret and should be a
4309base64 encrypted string of the 16-byte IV.
4310
4311The simplest (insecure) usage is to provide the secret inline
4312
4313@example
4314
4315 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4316
4317@end example
4318
4319The simplest secure usage is to provide the secret via a file
4320
4321 # printf "letmein" > mypasswd.txt
4322 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4323
4324For greater security, AES-256-CBC should be used. To illustrate usage,
4325consider the openssl command line tool which can encrypt the data. Note
4326that when encrypting, the plaintext must be padded to the cipher block
4327size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4328
4329First a master key needs to be created in base64 encoding:
4330
4331@example
4332 # openssl rand -base64 32 > key.b64
4333 # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')
4334@end example
4335
4336Each secret to be encrypted needs to have a random initialization vector
4337generated. These do not need to be kept secret
4338
4339@example
4340 # openssl rand -base64 16 > iv.b64
4341 # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')
4342@end example
4343
4344The secret to be defined can now be encrypted, in this case we're
4345telling openssl to base64 encode the result, but it could be left
4346as raw bytes if desired.
4347
4348@example
4349 # SECRET=$(printf "letmein" |
4350            openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4351@end example
4352
4353When launching QEMU, create a master secret pointing to @code{key.b64}
4354and specify that to be used to decrypt the user password. Pass the
4355contents of @code{iv.b64} to the second secret
4356
4357@example
4358 # $QEMU \
4359     -object secret,id=secmaster0,format=base64,file=key.b64 \
4360     -object secret,id=sec0,keyid=secmaster0,format=base64,\
4361         data=$SECRET,iv=$(<iv.b64)
4362@end example
4363
4364@item -object sev-guest,id=@var{id},cbitpos=@var{cbitpos},reduced-phys-bits=@var{val},[sev-device=@var{string},policy=@var{policy},handle=@var{handle},dh-cert-file=@var{file},session-file=@var{file}]
4365
4366Create a Secure Encrypted Virtualization (SEV) guest object, which can be used
4367to provide the guest memory encryption support on AMD processors.
4368
4369When memory encryption is enabled, one of the physical address bit (aka the
4370C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos}
4371is used to provide the C-bit position. The C-bit position is Host family dependent
4372hence user must provide this value. On EPYC, the value should be 47.
4373
4374When memory encryption is enabled, we loose certain bits in physical address space.
4375The @option{reduced-phys-bits} is used to provide the number of bits we loose in
4376physical address space. Similar to C-bit, the value is Host family dependent.
4377On EPYC, the value should be 5.
4378
4379The @option{sev-device} provides the device file to use for communicating with
4380the SEV firmware running inside AMD Secure Processor. The default device is
4381'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are
4382created by CCP driver.
4383
4384The @option{policy} provides the guest policy to be enforced by the SEV firmware
4385and restrict what configuration and operational commands can be performed on this
4386guest by the hypervisor. The policy should be provided by the guest owner and is
4387bound to the guest and cannot be changed throughout the lifetime of the guest.
4388The default is 0.
4389
4390If guest @option{policy} allows sharing the key with another SEV guest then
4391@option{handle} can be use to provide handle of the guest from which to share
4392the key.
4393
4394The @option{dh-cert-file} and @option{session-file} provides the guest owner's
4395Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters
4396are used for establishing a cryptographic session with the guest owner to
4397negotiate keys used for attestation. The file must be encoded in base64.
4398
4399e.g to launch a SEV guest
4400@example
4401 # $QEMU \
4402     ......
4403     -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
4404     -machine ...,memory-encryption=sev0
4405     .....
4406
4407@end example
4408@end table
4409
4410ETEXI
4411
4412
4413HXCOMM This is the last statement. Insert new options before this line!
4414STEXI
4415@end table
4416ETEXI
4417