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 or tcg (default: tcg)\n"
  35    "                kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n"
  36    "                vmport=on|off|auto controls emulation of vmport (default: auto)\n"
  37    "                kvm_shadow_mem=size of KVM shadow MMU in bytes\n"
  38    "                dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
  39    "                mem-merge=on|off controls memory merge support (default: on)\n"
  40    "                igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n"
  41    "                aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
  42    "                dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
  43    "                suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
  44    "                nvdimm=on|off controls NVDIMM support (default=off)\n"
  45    "                enforce-config-section=on|off enforce configuration section migration (default=off)\n"
  46    "                s390-squash-mcss=on|off controls support for squashing into default css (default=off)\n",
  47    QEMU_ARCH_ALL)
  48STEXI
  49@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
  50@findex -machine
  51Select the emulated machine by @var{name}. Use @code{-machine help} to list
  52available machines.
  53
  54For architectures which aim to support live migration compatibility
  55across releases, each release will introduce a new versioned machine
  56type. For example, the 2.8.0 release introduced machine types
  57``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures.
  58
  59To allow live migration of guests from QEMU version 2.8.0, to QEMU
  60version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8''
  61and ``pc-q35-2.8'' machines too. To allow users live migrating VMs
  62to skip multiple intermediate releases when upgrading, new releases
  63of QEMU will support machine types from many previous versions.
  64
  65Supported machine properties are:
  66@table @option
  67@item accel=@var{accels1}[:@var{accels2}[:...]]
  68This is used to enable an accelerator. Depending on the target architecture,
  69kvm, xen, hax or tcg can be available. By default, tcg is used. If there is
  70more than one accelerator specified, the next one is used if the previous one
  71fails to initialize.
  72@item kernel_irqchip=on|off
  73Controls in-kernel irqchip support for the chosen accelerator when available.
  74@item gfx_passthru=on|off
  75Enables IGD GFX passthrough support for the chosen machine when available.
  76@item vmport=on|off|auto
  77Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
  78value based on accel. For accel=xen the default is off otherwise the default
  79is on.
  80@item kvm_shadow_mem=size
  81Defines the size of the KVM shadow MMU.
  82@item dump-guest-core=on|off
  83Include guest memory in a core dump. The default is on.
  84@item mem-merge=on|off
  85Enables or disables memory merge support. This feature, when supported by
  86the host, de-duplicates identical memory pages among VMs instances
  87(enabled by default).
  88@item aes-key-wrap=on|off
  89Enables or disables AES key wrapping support on s390-ccw hosts. This feature
  90controls whether AES wrapping keys will be created to allow
  91execution of AES cryptographic functions.  The default is on.
  92@item dea-key-wrap=on|off
  93Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
  94controls whether DEA wrapping keys will be created to allow
  95execution of DEA cryptographic functions.  The default is on.
  96@item nvdimm=on|off
  97Enables or disables NVDIMM support. The default is off.
  98@item s390-squash-mcss=on|off
  99Enables or disables squashing subchannels into the default css.
 100The default is off.
 101@item enforce-config-section=on|off
 102If @option{enforce-config-section} is set to @var{on}, force migration
 103code to send configuration section even if the machine-type sets the
 104@option{migration.send-configuration} property to @var{off}.
 105NOTE: this parameter is deprecated. Please use @option{-global}
 106@option{migration.send-configuration}=@var{on|off} instead.
 107@end table
 108ETEXI
 109
 110HXCOMM Deprecated by -machine
 111DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
 112
 113DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
 114    "-cpu cpu        select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
 115STEXI
 116@item -cpu @var{model}
 117@findex -cpu
 118Select CPU model (@code{-cpu help} for list and additional feature selection)
 119ETEXI
 120
 121DEF("accel", HAS_ARG, QEMU_OPTION_accel,
 122    "-accel [accel=]accelerator[,thread=single|multi]\n"
 123    "                select accelerator (kvm, xen, hax or tcg; use 'help' for a list)\n"
 124    "                thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL)
 125STEXI
 126@item -accel @var{name}[,prop=@var{value}[,...]]
 127@findex -accel
 128This is used to enable an accelerator. Depending on the target architecture,
 129kvm, xen, hax or tcg can be available. By default, tcg is used. If there is
 130more than one accelerator specified, the next one is used if the previous one
 131fails to initialize.
 132@table @option
 133@item thread=single|multi
 134Controls number of TCG threads. When the TCG is multi-threaded there will be one
 135thread per vCPU therefor taking advantage of additional host cores. The default
 136is to enable multi-threading where both the back-end and front-ends support it and
 137no incompatible TCG features have been enabled (e.g. icount/replay).
 138@end table
 139ETEXI
 140
 141DEF("smp", HAS_ARG, QEMU_OPTION_smp,
 142    "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
 143    "                set the number of CPUs to 'n' [default=1]\n"
 144    "                maxcpus= maximum number of total cpus, including\n"
 145    "                offline CPUs for hotplug, etc\n"
 146    "                cores= number of CPU cores on one socket\n"
 147    "                threads= number of threads on one CPU core\n"
 148    "                sockets= number of discrete sockets in the system\n",
 149        QEMU_ARCH_ALL)
 150STEXI
 151@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
 152@findex -smp
 153Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
 154CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
 155to 4.
 156For the PC target, the number of @var{cores} per socket, the number
 157of @var{threads} per cores and the total number of @var{sockets} can be
 158specified. Missing values will be computed. If any on the three values is
 159given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
 160specifies the maximum number of hotpluggable CPUs.
 161ETEXI
 162
 163DEF("numa", HAS_ARG, QEMU_OPTION_numa,
 164    "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
 165    "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
 166    "-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL)
 167STEXI
 168@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
 169@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
 170@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
 171@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}]
 172@findex -numa
 173Define a NUMA node and assign RAM and VCPUs to it.
 174Set the NUMA distance from a source node to a destination node.
 175
 176Legacy VCPU assignment uses @samp{cpus} option where
 177@var{firstcpu} and @var{lastcpu} are CPU indexes. Each
 178@samp{cpus} option represent a contiguous range of CPU indexes
 179(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous
 180set of VCPUs can be represented by providing multiple @samp{cpus}
 181options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically
 182split between them.
 183
 184For example, the following option assigns VCPUs 0, 1, 2 and 5 to
 185a NUMA node:
 186@example
 187-numa node,cpus=0-2,cpus=5
 188@end example
 189
 190@samp{cpu} option is a new alternative to @samp{cpus} option
 191which uses @samp{socket-id|core-id|thread-id} properties to assign
 192CPU objects to a @var{node} using topology layout properties of CPU.
 193The set of properties is machine specific, and depends on used
 194machine type/@samp{smp} options. It could be queried with
 195@samp{hotpluggable-cpus} monitor command.
 196@samp{node-id} property specifies @var{node} to which CPU object
 197will be assigned, it's required for @var{node} to be declared
 198with @samp{node} option before it's used with @samp{cpu} option.
 199
 200For example:
 201@example
 202-M pc \
 203-smp 1,sockets=2,maxcpus=2 \
 204-numa node,nodeid=0 -numa node,nodeid=1 \
 205-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
 206@end example
 207
 208@samp{mem} assigns a given RAM amount to a node. @samp{memdev}
 209assigns RAM from a given memory backend device to a node. If
 210@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
 211split equally between them.
 212
 213@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
 214if one node uses @samp{memdev}, all of them have to use it.
 215
 216@var{source} and @var{destination} are NUMA node IDs.
 217@var{distance} is the NUMA distance from @var{source} to @var{destination}.
 218The distance from a node to itself is always 10. If any pair of nodes is
 219given a distance, then all pairs must be given distances. Although, when
 220distances are only given in one direction for each pair of nodes, then
 221the distances in the opposite directions are assumed to be the same. If,
 222however, an asymmetrical pair of distances is given for even one node
 223pair, then all node pairs must be provided distance values for both
 224directions, even when they are symmetrical. When a node is unreachable
 225from another node, set the pair's distance to 255.
 226
 227Note that the -@option{numa} option doesn't allocate any of the
 228specified resources, it just assigns existing resources to NUMA
 229nodes. This means that one still has to use the @option{-m},
 230@option{-smp} options to allocate RAM and VCPUs respectively.
 231
 232ETEXI
 233
 234DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
 235    "-add-fd fd=fd,set=set[,opaque=opaque]\n"
 236    "                Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
 237STEXI
 238@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
 239@findex -add-fd
 240
 241Add a file descriptor to an fd set.  Valid options are:
 242
 243@table @option
 244@item fd=@var{fd}
 245This option defines the file descriptor of which a duplicate is added to fd set.
 246The file descriptor cannot be stdin, stdout, or stderr.
 247@item set=@var{set}
 248This option defines the ID of the fd set to add the file descriptor to.
 249@item opaque=@var{opaque}
 250This option defines a free-form string that can be used to describe @var{fd}.
 251@end table
 252
 253You can open an image using pre-opened file descriptors from an fd set:
 254@example
 255qemu-system-i386
 256-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
 257-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
 258-drive file=/dev/fdset/2,index=0,media=disk
 259@end example
 260ETEXI
 261
 262DEF("set", HAS_ARG, QEMU_OPTION_set,
 263    "-set group.id.arg=value\n"
 264    "                set <arg> parameter for item <id> of type <group>\n"
 265    "                i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
 266STEXI
 267@item -set @var{group}.@var{id}.@var{arg}=@var{value}
 268@findex -set
 269Set parameter @var{arg} for item @var{id} of type @var{group}
 270ETEXI
 271
 272DEF("global", HAS_ARG, QEMU_OPTION_global,
 273    "-global driver.property=value\n"
 274    "-global driver=driver,property=property,value=value\n"
 275    "                set a global default for a driver property\n",
 276    QEMU_ARCH_ALL)
 277STEXI
 278@item -global @var{driver}.@var{prop}=@var{value}
 279@itemx -global driver=@var{driver},property=@var{property},value=@var{value}
 280@findex -global
 281Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
 282
 283@example
 284qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
 285@end example
 286
 287In particular, you can use this to set driver properties for devices which are
 288created automatically by the machine model. To create a device which is not
 289created automatically and set properties on it, use -@option{device}.
 290
 291-global @var{driver}.@var{prop}=@var{value} is shorthand for -global
 292driver=@var{driver},property=@var{prop},value=@var{value}.  The
 293longhand syntax works even when @var{driver} contains a dot.
 294ETEXI
 295
 296DEF("boot", HAS_ARG, QEMU_OPTION_boot,
 297    "-boot [order=drives][,once=drives][,menu=on|off]\n"
 298    "      [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
 299    "                'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
 300    "                'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
 301    "                'sp_time': the period that splash picture last if menu=on, unit is ms\n"
 302    "                'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
 303    QEMU_ARCH_ALL)
 304STEXI
 305@item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off]
 306@findex -boot
 307Specify boot order @var{drives} as a string of drive letters. Valid
 308drive letters depend on the target architecture. The x86 PC uses: a, b
 309(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
 310from network adapter 1-4), hard disk boot is the default. To apply a
 311particular boot order only on the first startup, specify it via
 312@option{once}. Note that the @option{order} or @option{once} parameter
 313should not be used together with the @option{bootindex} property of
 314devices, since the firmware implementations normally do not support both
 315at the same time.
 316
 317Interactive boot menus/prompts can be enabled via @option{menu=on} as far
 318as firmware/BIOS supports them. The default is non-interactive boot.
 319
 320A splash picture could be passed to bios, enabling user to show it as logo,
 321when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
 322supports them. Currently Seabios for X86 system support it.
 323limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
 324format(true color). The resolution should be supported by the SVGA mode, so
 325the recommended is 320x240, 640x480, 800x640.
 326
 327A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
 328when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
 329reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
 330system support it.
 331
 332Do strict boot via @option{strict=on} as far as firmware/BIOS
 333supports it. This only effects when boot priority is changed by
 334bootindex options. The default is non-strict boot.
 335
 336@example
 337# try to boot from network first, then from hard disk
 338qemu-system-i386 -boot order=nc
 339# boot from CD-ROM first, switch back to default order after reboot
 340qemu-system-i386 -boot once=d
 341# boot with a splash picture for 5 seconds.
 342qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
 343@end example
 344
 345Note: The legacy format '-boot @var{drives}' is still supported but its
 346use is discouraged as it may be removed from future versions.
 347ETEXI
 348
 349DEF("m", HAS_ARG, QEMU_OPTION_m,
 350    "-m [size=]megs[,slots=n,maxmem=size]\n"
 351    "                configure guest RAM\n"
 352    "                size: initial amount of guest memory\n"
 353    "                slots: number of hotplug slots (default: none)\n"
 354    "                maxmem: maximum amount of guest memory (default: none)\n"
 355    "NOTE: Some architectures might enforce a specific granularity\n",
 356    QEMU_ARCH_ALL)
 357STEXI
 358@item -m [size=]@var{megs}[,slots=n,maxmem=size]
 359@findex -m
 360Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
 361Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
 362megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
 363could be used to set amount of hotpluggable memory slots and maximum amount of
 364memory. Note that @var{maxmem} must be aligned to the page size.
 365
 366For example, the following command-line sets the guest startup RAM size to
 3671GB, creates 3 slots to hotplug additional memory and sets the maximum
 368memory the guest can reach to 4GB:
 369
 370@example
 371qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
 372@end example
 373
 374If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
 375be enabled and the guest startup RAM will never increase.
 376ETEXI
 377
 378DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
 379    "-mem-path FILE  provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
 380STEXI
 381@item -mem-path @var{path}
 382@findex -mem-path
 383Allocate guest RAM from a temporarily created file in @var{path}.
 384ETEXI
 385
 386DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
 387    "-mem-prealloc   preallocate guest memory (use with -mem-path)\n",
 388    QEMU_ARCH_ALL)
 389STEXI
 390@item -mem-prealloc
 391@findex -mem-prealloc
 392Preallocate memory when using -mem-path.
 393ETEXI
 394
 395DEF("k", HAS_ARG, QEMU_OPTION_k,
 396    "-k language     use keyboard layout (for example 'fr' for French)\n",
 397    QEMU_ARCH_ALL)
 398STEXI
 399@item -k @var{language}
 400@findex -k
 401Use keyboard layout @var{language} (for example @code{fr} for
 402French). This option is only needed where it is not easy to get raw PC
 403keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
 404display). You don't normally need to use it on PC/Linux or PC/Windows
 405hosts.
 406
 407The available layouts are:
 408@example
 409ar  de-ch  es  fo     fr-ca  hu  ja  mk     no  pt-br  sv
 410da  en-gb  et  fr     fr-ch  is  lt  nl     pl  ru     th
 411de  en-us  fi  fr-be  hr     it  lv  nl-be  pt  sl     tr
 412@end example
 413
 414The default is @code{en-us}.
 415ETEXI
 416
 417
 418DEF("audio-help", 0, QEMU_OPTION_audio_help,
 419    "-audio-help     print list of audio drivers and their options\n",
 420    QEMU_ARCH_ALL)
 421STEXI
 422@item -audio-help
 423@findex -audio-help
 424Will show the audio subsystem help: list of drivers, tunable
 425parameters.
 426ETEXI
 427
 428DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
 429    "-soundhw c1,... enable audio support\n"
 430    "                and only specified sound cards (comma separated list)\n"
 431    "                use '-soundhw help' to get the list of supported cards\n"
 432    "                use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
 433STEXI
 434@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
 435@findex -soundhw
 436Enable audio and selected sound hardware. Use 'help' to print all
 437available sound hardware.
 438
 439@example
 440qemu-system-i386 -soundhw sb16,adlib disk.img
 441qemu-system-i386 -soundhw es1370 disk.img
 442qemu-system-i386 -soundhw ac97 disk.img
 443qemu-system-i386 -soundhw hda disk.img
 444qemu-system-i386 -soundhw all disk.img
 445qemu-system-i386 -soundhw help
 446@end example
 447
 448Note that Linux's i810_audio OSS kernel (for AC97) module might
 449require manually specifying clocking.
 450
 451@example
 452modprobe i810_audio clocking=48000
 453@end example
 454ETEXI
 455
 456DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
 457    "-balloon none   disable balloon device\n"
 458    "-balloon virtio[,addr=str]\n"
 459    "                enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
 460STEXI
 461@item -balloon none
 462@findex -balloon
 463Disable balloon device.
 464@item -balloon virtio[,addr=@var{addr}]
 465Enable virtio balloon device (default), optionally with PCI address
 466@var{addr}.
 467ETEXI
 468
 469DEF("device", HAS_ARG, QEMU_OPTION_device,
 470    "-device driver[,prop[=value][,...]]\n"
 471    "                add device (based on driver)\n"
 472    "                prop=value,... sets driver properties\n"
 473    "                use '-device help' to print all possible drivers\n"
 474    "                use '-device driver,help' to print all possible properties\n",
 475    QEMU_ARCH_ALL)
 476STEXI
 477@item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
 478@findex -device
 479Add device @var{driver}.  @var{prop}=@var{value} sets driver
 480properties.  Valid properties depend on the driver.  To get help on
 481possible drivers and properties, use @code{-device help} and
 482@code{-device @var{driver},help}.
 483
 484Some drivers are:
 485@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
 486
 487Add an IPMI BMC.  This is a simulation of a hardware management
 488interface processor that normally sits on a system.  It provides
 489a watchdog and the ability to reset and power control the system.
 490You need to connect this to an IPMI interface to make it useful
 491
 492The IPMI slave address to use for the BMC.  The default is 0x20.
 493This address is the BMC's address on the I2C network of management
 494controllers.  If you don't know what this means, it is safe to ignore
 495it.
 496
 497@table @option
 498@item bmc=@var{id}
 499The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
 500@item slave_addr=@var{val}
 501Define slave address to use for the BMC.  The default is 0x20.
 502@item sdrfile=@var{file}
 503file containing raw Sensor Data Records (SDR) data. The default is none.
 504@item fruareasize=@var{val}
 505size of a Field Replaceable Unit (FRU) area.  The default is 1024.
 506@item frudatafile=@var{file}
 507file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
 508@end table
 509
 510@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
 511
 512Add a connection to an external IPMI BMC simulator.  Instead of
 513locally emulating the BMC like the above item, instead connect
 514to an external entity that provides the IPMI services.
 515
 516A connection is made to an external BMC simulator.  If you do this, it
 517is strongly recommended that you use the "reconnect=" chardev option
 518to reconnect to the simulator if the connection is lost.  Note that if
 519this is not used carefully, it can be a security issue, as the
 520interface has the ability to send resets, NMIs, and power off the VM.
 521It's best if QEMU makes a connection to an external simulator running
 522on a secure port on localhost, so neither the simulator nor QEMU is
 523exposed to any outside network.
 524
 525See the "lanserv/README.vm" file in the OpenIPMI library for more
 526details on the external interface.
 527
 528@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
 529
 530Add a KCS IPMI interafce on the ISA bus.  This also adds a
 531corresponding ACPI and SMBIOS entries, if appropriate.
 532
 533@table @option
 534@item bmc=@var{id}
 535The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
 536@item ioport=@var{val}
 537Define the I/O address of the interface.  The default is 0xca0 for KCS.
 538@item irq=@var{val}
 539Define the interrupt to use.  The default is 5.  To disable interrupts,
 540set this to 0.
 541@end table
 542
 543@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}]
 544
 545Like the KCS interface, but defines a BT interface.  The default port is
 5460xe4 and the default interrupt is 5.
 547
 548ETEXI
 549
 550DEF("name", HAS_ARG, QEMU_OPTION_name,
 551    "-name string1[,process=string2][,debug-threads=on|off]\n"
 552    "                set the name of the guest\n"
 553    "                string1 sets the window title and string2 the process name (on Linux)\n"
 554    "                When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
 555    "                NOTE: The thread names are for debugging and not a stable API.\n",
 556    QEMU_ARCH_ALL)
 557STEXI
 558@item -name @var{name}
 559@findex -name
 560Sets the @var{name} of the guest.
 561This name will be displayed in the SDL window caption.
 562The @var{name} will also be used for the VNC server.
 563Also optionally set the top visible process name in Linux.
 564Naming of individual threads can also be enabled on Linux to aid debugging.
 565ETEXI
 566
 567DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
 568    "-uuid %08x-%04x-%04x-%04x-%012x\n"
 569    "                specify machine UUID\n", QEMU_ARCH_ALL)
 570STEXI
 571@item -uuid @var{uuid}
 572@findex -uuid
 573Set system UUID.
 574ETEXI
 575
 576STEXI
 577@end table
 578ETEXI
 579DEFHEADING()
 580
 581DEFHEADING(Block device options:)
 582STEXI
 583@table @option
 584ETEXI
 585
 586DEF("fda", HAS_ARG, QEMU_OPTION_fda,
 587    "-fda/-fdb file  use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
 588DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
 589STEXI
 590@item -fda @var{file}
 591@itemx -fdb @var{file}
 592@findex -fda
 593@findex -fdb
 594Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
 595ETEXI
 596
 597DEF("hda", HAS_ARG, QEMU_OPTION_hda,
 598    "-hda/-hdb file  use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
 599DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
 600DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
 601    "-hdc/-hdd file  use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
 602DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
 603STEXI
 604@item -hda @var{file}
 605@itemx -hdb @var{file}
 606@itemx -hdc @var{file}
 607@itemx -hdd @var{file}
 608@findex -hda
 609@findex -hdb
 610@findex -hdc
 611@findex -hdd
 612Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
 613ETEXI
 614
 615DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
 616    "-cdrom file     use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
 617    QEMU_ARCH_ALL)
 618STEXI
 619@item -cdrom @var{file}
 620@findex -cdrom
 621Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
 622@option{-cdrom} at the same time). You can use the host CD-ROM by
 623using @file{/dev/cdrom} as filename (@pxref{host_drives}).
 624ETEXI
 625
 626DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
 627    "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
 628    "          [,cache.direct=on|off][,cache.no-flush=on|off]\n"
 629    "          [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
 630    "          [,driver specific parameters...]\n"
 631    "                configure a block backend\n", QEMU_ARCH_ALL)
 632STEXI
 633@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]]
 634@findex -blockdev
 635
 636Define a new block driver node. Some of the options apply to all block drivers,
 637other options are only accepted for a specific block driver. See below for a
 638list of generic options and options for the most common block drivers.
 639
 640Options that expect a reference to another node (e.g. @code{file}) can be
 641given in two ways. Either you specify the node name of an already existing node
 642(file=@var{node-name}), or you define a new node inline, adding options
 643for the referenced node after a dot (file.filename=@var{path},file.aio=native).
 644
 645A block driver node created with @option{-blockdev} can be used for a guest
 646device by specifying its node name for the @code{drive} property in a
 647@option{-device} argument that defines a block device.
 648
 649@table @option
 650@item Valid options for any block driver node:
 651
 652@table @code
 653@item driver
 654Specifies the block driver to use for the given node.
 655@item node-name
 656This defines the name of the block driver node by which it will be referenced
 657later. The name must be unique, i.e. it must not match the name of a different
 658block driver node, or (if you use @option{-drive} as well) the ID of a drive.
 659
 660If no node name is specified, it is automatically generated. The generated node
 661name is not intended to be predictable and changes between QEMU invocations.
 662For the top level, an explicit node name must be specified.
 663@item read-only
 664Open the node read-only. Guest write attempts will fail.
 665@item cache.direct
 666The host page cache can be avoided with @option{cache.direct=on}. This will
 667attempt to do disk IO directly to the guest's memory. QEMU may still perform an
 668internal copy of the data.
 669@item cache.no-flush
 670In case you don't care about data integrity over host failures, you can use
 671@option{cache.no-flush=on}. This option tells QEMU that it never needs to write
 672any data to the disk but can instead keep things in cache. If anything goes
 673wrong, like your host losing power, the disk storage getting disconnected
 674accidentally, etc. your image will most probably be rendered unusable.
 675@item discard=@var{discard}
 676@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls
 677whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are
 678ignored or passed to the filesystem. Some machine types may not support
 679discard requests.
 680@item detect-zeroes=@var{detect-zeroes}
 681@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
 682conversion of plain zero writes by the OS to driver specific optimized
 683zero write commands. You may even choose "unmap" if @var{discard} is set
 684to "unmap" to allow a zero write to be converted to an @code{unmap} operation.
 685@end table
 686
 687@item Driver-specific options for @code{file}
 688
 689This is the protocol-level block driver for accessing regular files.
 690
 691@table @code
 692@item filename
 693The path to the image file in the local filesystem
 694@item aio
 695Specifies the AIO backend (threads/native, default: threads)
 696@item locking
 697Specifies whether the image file is protected with Linux OFD / POSIX locks. The
 698default is to use the Linux Open File Descriptor API if available, otherwise no
 699lock is applied.  (auto/on/off, default: auto)
 700@end table
 701Example:
 702@example
 703-blockdev driver=file,node-name=disk,filename=disk.img
 704@end example
 705
 706@item Driver-specific options for @code{raw}
 707
 708This is the image format block driver for raw images. It is usually
 709stacked on top of a protocol level block driver such as @code{file}.
 710
 711@table @code
 712@item file
 713Reference to or definition of the data source block driver node
 714(e.g. a @code{file} driver node)
 715@end table
 716Example 1:
 717@example
 718-blockdev driver=file,node-name=disk_file,filename=disk.img
 719-blockdev driver=raw,node-name=disk,file=disk_file
 720@end example
 721Example 2:
 722@example
 723-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
 724@end example
 725
 726@item Driver-specific options for @code{qcow2}
 727
 728This is the image format block driver for qcow2 images. It is usually
 729stacked on top of a protocol level block driver such as @code{file}.
 730
 731@table @code
 732@item file
 733Reference to or definition of the data source block driver node
 734(e.g. a @code{file} driver node)
 735
 736@item backing
 737Reference to or definition of the backing file block device (default is taken
 738from the image file). It is allowed to pass an empty string here in order to
 739disable the default backing file.
 740
 741@item lazy-refcounts
 742Whether to enable the lazy refcounts feature (on/off; default is taken from the
 743image file)
 744
 745@item cache-size
 746The maximum total size of the L2 table and refcount block caches in bytes
 747(default: 1048576 bytes or 8 clusters, whichever is larger)
 748
 749@item l2-cache-size
 750The maximum size of the L2 table cache in bytes
 751(default: 4/5 of the total cache size)
 752
 753@item refcount-cache-size
 754The maximum size of the refcount block cache in bytes
 755(default: 1/5 of the total cache size)
 756
 757@item cache-clean-interval
 758Clean unused entries in the L2 and refcount caches. The interval is in seconds.
 759The default value is 0 and it disables this feature.
 760
 761@item pass-discard-request
 762Whether discard requests to the qcow2 device should be forwarded to the data
 763source (on/off; default: on if discard=unmap is specified, off otherwise)
 764
 765@item pass-discard-snapshot
 766Whether discard requests for the data source should be issued when a snapshot
 767operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off;
 768default: on)
 769
 770@item pass-discard-other
 771Whether discard requests for the data source should be issued on other
 772occasions where a cluster gets freed (on/off; default: off)
 773
 774@item overlap-check
 775Which overlap checks to perform for writes to the image
 776(none/constant/cached/all; default: cached). For details or finer
 777granularity control refer to the QAPI documentation of @code{blockdev-add}.
 778@end table
 779
 780Example 1:
 781@example
 782-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
 783-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
 784@end example
 785Example 2:
 786@example
 787-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
 788@end example
 789
 790@item Driver-specific options for other drivers
 791Please refer to the QAPI documentation of the @code{blockdev-add} QMP command.
 792
 793@end table
 794
 795ETEXI
 796
 797DEF("drive", HAS_ARG, QEMU_OPTION_drive,
 798    "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
 799    "       [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
 800    "       [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
 801    "       [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
 802    "       [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
 803    "       [,readonly=on|off][,copy-on-read=on|off]\n"
 804    "       [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
 805    "       [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
 806    "       [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
 807    "       [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
 808    "       [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
 809    "       [[,iops_size=is]]\n"
 810    "       [[,group=g]]\n"
 811    "                use 'file' as a drive image\n", QEMU_ARCH_ALL)
 812STEXI
 813@item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
 814@findex -drive
 815
 816Define a new drive. This includes creating a block driver node (the backend) as
 817well as a guest device, and is mostly a shortcut for defining the corresponding
 818@option{-blockdev} and @option{-device} options.
 819
 820@option{-drive} accepts all options that are accepted by @option{-blockdev}. In
 821addition, it knows the following options:
 822
 823@table @option
 824@item file=@var{file}
 825This option defines which disk image (@pxref{disk_images}) to use with
 826this drive. If the filename contains comma, you must double it
 827(for instance, "file=my,,file" to use file "my,file").
 828
 829Special files such as iSCSI devices can be specified using protocol
 830specific URLs. See the section for "Device URL Syntax" for more information.
 831@item if=@var{interface}
 832This option defines on which type on interface the drive is connected.
 833Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none.
 834@item bus=@var{bus},unit=@var{unit}
 835These options define where is connected the drive by defining the bus number and
 836the unit id.
 837@item index=@var{index}
 838This option defines where is connected the drive by using an index in the list
 839of available connectors of a given interface type.
 840@item media=@var{media}
 841This option defines the type of the media: disk or cdrom.
 842@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
 843These options have the same definition as they have in @option{-hdachs}.
 844These parameters are deprecated, use the corresponding parameters
 845of @code{-device} instead.
 846@item snapshot=@var{snapshot}
 847@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
 848(see @option{-snapshot}).
 849@item cache=@var{cache}
 850@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
 851and controls how the host cache is used to access block data. This is a
 852shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
 853options (as in @option{-blockdev}), and additionally @option{cache.writeback},
 854which provides a default for the @option{write-cache} option of block guest
 855devices (as in @option{-device}). The modes correspond to the following
 856settings:
 857
 858@c Our texi2pod.pl script doesn't support @multitable, so fall back to using
 859@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
 860@c and the HTML output.
 861@example
 862@             │ cache.writeback   cache.direct   cache.no-flush
 863─────────────┼─────────────────────────────────────────────────
 864writeback    │ on                off            off
 865none         │ on                on             off
 866writethrough │ off               off            off
 867directsync   │ off               on             off
 868unsafe       │ on                off            on
 869@end example
 870
 871The default mode is @option{cache=writeback}.
 872
 873@item aio=@var{aio}
 874@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
 875@item format=@var{format}
 876Specify which disk @var{format} will be used rather than detecting
 877the format.  Can be used to specify format=raw to avoid interpreting
 878an untrusted format header.
 879@item serial=@var{serial}
 880This option specifies the serial number to assign to the device. This
 881parameter is deprecated, use the corresponding parameter of @code{-device}
 882instead.
 883@item addr=@var{addr}
 884Specify the controller's PCI address (if=virtio only). This parameter is
 885deprecated, use the corresponding parameter of @code{-device} instead.
 886@item werror=@var{action},rerror=@var{action}
 887Specify which @var{action} to take on write and read errors. Valid actions are:
 888"ignore" (ignore the error and try to continue), "stop" (pause QEMU),
 889"report" (report the error to the guest), "enospc" (pause QEMU only if the
 890host disk is full; report the error to the guest otherwise).
 891The default setting is @option{werror=enospc} and @option{rerror=report}.
 892@item copy-on-read=@var{copy-on-read}
 893@var{copy-on-read} is "on" or "off" and enables whether to copy read backing
 894file sectors into the image file.
 895@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
 896Specify bandwidth throttling limits in bytes per second, either for all request
 897types or for reads or writes only.  Small values can lead to timeouts or hangs
 898inside the guest.  A safe minimum for disks is 2 MB/s.
 899@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
 900Specify bursts in bytes per second, either for all request types or for reads
 901or writes only.  Bursts allow the guest I/O to spike above the limit
 902temporarily.
 903@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
 904Specify request rate limits in requests per second, either for all request
 905types or for reads or writes only.
 906@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
 907Specify bursts in requests per second, either for all request types or for reads
 908or writes only.  Bursts allow the guest I/O to spike above the limit
 909temporarily.
 910@item iops_size=@var{is}
 911Let every @var{is} bytes of a request count as a new request for iops
 912throttling purposes.  Use this option to prevent guests from circumventing iops
 913limits by sending fewer but larger requests.
 914@item group=@var{g}
 915Join a throttling quota group with given name @var{g}.  All drives that are
 916members of the same group are accounted for together.  Use this option to
 917prevent guests from circumventing throttling limits by using many small disks
 918instead of a single larger disk.
 919@end table
 920
 921By default, the @option{cache.writeback=on} mode is used. It will report data
 922writes as completed as soon as the data is present in the host page cache.
 923This is safe as long as your guest OS makes sure to correctly flush disk caches
 924where needed. If your guest OS does not handle volatile disk write caches
 925correctly and your host crashes or loses power, then the guest may experience
 926data corruption.
 927
 928For such guests, you should consider using @option{cache.writeback=off}. This
 929means that the host page cache will be used to read and write data, but write
 930notification will be sent to the guest only after QEMU has made sure to flush
 931each write to the disk. Be aware that this has a major impact on performance.
 932
 933When using the @option{-snapshot} option, unsafe caching is always used.
 934
 935Copy-on-read avoids accessing the same backing file sectors repeatedly and is
 936useful when the backing file is over a slow network.  By default copy-on-read
 937is off.
 938
 939Instead of @option{-cdrom} you can use:
 940@example
 941qemu-system-i386 -drive file=file,index=2,media=cdrom
 942@end example
 943
 944Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
 945use:
 946@example
 947qemu-system-i386 -drive file=file,index=0,media=disk
 948qemu-system-i386 -drive file=file,index=1,media=disk
 949qemu-system-i386 -drive file=file,index=2,media=disk
 950qemu-system-i386 -drive file=file,index=3,media=disk
 951@end example
 952
 953You can open an image using pre-opened file descriptors from an fd set:
 954@example
 955qemu-system-i386
 956-add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
 957-add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
 958-drive file=/dev/fdset/2,index=0,media=disk
 959@end example
 960
 961You can connect a CDROM to the slave of ide0:
 962@example
 963qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
 964@end example
 965
 966If you don't specify the "file=" argument, you define an empty drive:
 967@example
 968qemu-system-i386 -drive if=ide,index=1,media=cdrom
 969@end example
 970
 971Instead of @option{-fda}, @option{-fdb}, you can use:
 972@example
 973qemu-system-i386 -drive file=file,index=0,if=floppy
 974qemu-system-i386 -drive file=file,index=1,if=floppy
 975@end example
 976
 977By default, @var{interface} is "ide" and @var{index} is automatically
 978incremented:
 979@example
 980qemu-system-i386 -drive file=a -drive file=b"
 981@end example
 982is interpreted like:
 983@example
 984qemu-system-i386 -hda a -hdb b
 985@end example
 986ETEXI
 987
 988DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
 989    "-mtdblock file  use 'file' as on-board Flash memory image\n",
 990    QEMU_ARCH_ALL)
 991STEXI
 992@item -mtdblock @var{file}
 993@findex -mtdblock
 994Use @var{file} as on-board Flash memory image.
 995ETEXI
 996
 997DEF("sd", HAS_ARG, QEMU_OPTION_sd,
 998    "-sd file        use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
 999STEXI
1000@item -sd @var{file}
1001@findex -sd
1002Use @var{file} as SecureDigital card image.
1003ETEXI
1004
1005DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
1006    "-pflash file    use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
1007STEXI
1008@item -pflash @var{file}
1009@findex -pflash
1010Use @var{file} as a parallel flash image.
1011ETEXI
1012
1013DEF("snapshot", 0, QEMU_OPTION_snapshot,
1014    "-snapshot       write to temporary files instead of disk image files\n",
1015    QEMU_ARCH_ALL)
1016STEXI
1017@item -snapshot
1018@findex -snapshot
1019Write to temporary files instead of disk image files. In this case,
1020the raw disk image you use is not written back. You can however force
1021the write back by pressing @key{C-a s} (@pxref{disk_images}).
1022ETEXI
1023
1024DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
1025    "-hdachs c,h,s[,t]\n" \
1026    "                force hard disk 0 physical geometry and the optional BIOS\n" \
1027    "                translation (t=none or lba) (usually QEMU can guess them)\n",
1028    QEMU_ARCH_ALL)
1029STEXI
1030@item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
1031@findex -hdachs
1032Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
1033@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
1034translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
1035all those parameters. This option is deprecated, please use
1036@code{-device ide-hd,cyls=c,heads=h,secs=s,...} instead.
1037ETEXI
1038
1039DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
1040    "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
1041    " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
1042    " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1043    " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1044    " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1045    " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
1046    " [[,throttling.iops-size=is]]\n",
1047    QEMU_ARCH_ALL)
1048
1049STEXI
1050
1051@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}]
1052@findex -fsdev
1053Define a new file system device. Valid options are:
1054@table @option
1055@item @var{fsdriver}
1056This option specifies the fs driver backend to use.
1057Currently "local", "handle" and "proxy" file system drivers are supported.
1058@item id=@var{id}
1059Specifies identifier for this device
1060@item path=@var{path}
1061Specifies the export path for the file system device. Files under
1062this path will be available to the 9p client on the guest.
1063@item security_model=@var{security_model}
1064Specifies the security model to be used for this export path.
1065Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1066In "passthrough" security model, files are stored using the same
1067credentials as they are created on the guest. This requires QEMU
1068to run as root. In "mapped-xattr" security model, some of the file
1069attributes like uid, gid, mode bits and link target are stored as
1070file attributes. For "mapped-file" these attributes are stored in the
1071hidden .virtfs_metadata directory. Directories exported by this security model cannot
1072interact with other unix tools. "none" security model is same as
1073passthrough except the sever won't report failures if it fails to
1074set file attributes like ownership. Security model is mandatory
1075only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
1076security model as a parameter.
1077@item writeout=@var{writeout}
1078This is an optional argument. The only supported value is "immediate".
1079This means that host page cache will be used to read and write data but
1080write notification will be sent to the guest only when the data has been
1081reported as written by the storage subsystem.
1082@item readonly
1083Enables exporting 9p share as a readonly mount for guests. By default
1084read-write access is given.
1085@item socket=@var{socket}
1086Enables proxy filesystem driver to use passed socket file for communicating
1087with virtfs-proxy-helper
1088@item sock_fd=@var{sock_fd}
1089Enables proxy filesystem driver to use passed socket descriptor for
1090communicating with virtfs-proxy-helper. Usually a helper like libvirt
1091will create socketpair and pass one of the fds as sock_fd
1092@item fmode=@var{fmode}
1093Specifies the default mode for newly created files on the host. Works only
1094with security models "mapped-xattr" and "mapped-file".
1095@item dmode=@var{dmode}
1096Specifies the default mode for newly created directories on the host. Works
1097only with security models "mapped-xattr" and "mapped-file".
1098@end table
1099
1100-fsdev option is used along with -device driver "virtio-9p-pci".
1101@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
1102Options for virtio-9p-pci driver are:
1103@table @option
1104@item fsdev=@var{id}
1105Specifies the id value specified along with -fsdev option
1106@item mount_tag=@var{mount_tag}
1107Specifies the tag name to be used by the guest to mount this export point
1108@end table
1109
1110ETEXI
1111
1112DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
1113    "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
1114    "        [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
1115    QEMU_ARCH_ALL)
1116
1117STEXI
1118
1119@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}]
1120@findex -virtfs
1121
1122The general form of a Virtual File system pass-through options are:
1123@table @option
1124@item @var{fsdriver}
1125This option specifies the fs driver backend to use.
1126Currently "local", "handle" and "proxy" file system drivers are supported.
1127@item id=@var{id}
1128Specifies identifier for this device
1129@item path=@var{path}
1130Specifies the export path for the file system device. Files under
1131this path will be available to the 9p client on the guest.
1132@item security_model=@var{security_model}
1133Specifies the security model to be used for this export path.
1134Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
1135In "passthrough" security model, files are stored using the same
1136credentials as they are created on the guest. This requires QEMU
1137to run as root. In "mapped-xattr" security model, some of the file
1138attributes like uid, gid, mode bits and link target are stored as
1139file attributes. For "mapped-file" these attributes are stored in the
1140hidden .virtfs_metadata directory. Directories exported by this security model cannot
1141interact with other unix tools. "none" security model is same as
1142passthrough except the sever won't report failures if it fails to
1143set file attributes like ownership. Security model is mandatory only
1144for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
1145model as a parameter.
1146@item writeout=@var{writeout}
1147This is an optional argument. The only supported value is "immediate".
1148This means that host page cache will be used to read and write data but
1149write notification will be sent to the guest only when the data has been
1150reported as written by the storage subsystem.
1151@item readonly
1152Enables exporting 9p share as a readonly mount for guests. By default
1153read-write access is given.
1154@item socket=@var{socket}
1155Enables proxy filesystem driver to use passed socket file for
1156communicating with virtfs-proxy-helper. Usually a helper like libvirt
1157will create socketpair and pass one of the fds as sock_fd
1158@item sock_fd
1159Enables proxy filesystem driver to use passed 'sock_fd' as the socket
1160descriptor for interfacing with virtfs-proxy-helper
1161@item fmode=@var{fmode}
1162Specifies the default mode for newly created files on the host. Works only
1163with security models "mapped-xattr" and "mapped-file".
1164@item dmode=@var{dmode}
1165Specifies the default mode for newly created directories on the host. Works
1166only with security models "mapped-xattr" and "mapped-file".
1167@end table
1168ETEXI
1169
1170DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
1171    "-virtfs_synth Create synthetic file system image\n",
1172    QEMU_ARCH_ALL)
1173STEXI
1174@item -virtfs_synth
1175@findex -virtfs_synth
1176Create synthetic file system image
1177ETEXI
1178
1179STEXI
1180@end table
1181ETEXI
1182DEFHEADING()
1183
1184DEFHEADING(USB options:)
1185STEXI
1186@table @option
1187ETEXI
1188
1189DEF("usb", 0, QEMU_OPTION_usb,
1190    "-usb            enable the USB driver (if it is not used by default yet)\n",
1191    QEMU_ARCH_ALL)
1192STEXI
1193@item -usb
1194@findex -usb
1195Enable the USB driver (if it is not used by default yet).
1196ETEXI
1197
1198DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1199    "-usbdevice name add the host or guest USB device 'name'\n",
1200    QEMU_ARCH_ALL)
1201STEXI
1202
1203@item -usbdevice @var{devname}
1204@findex -usbdevice
1205Add the USB device @var{devname}. Note that this option is deprecated,
1206please use @code{-device usb-...} instead. @xref{usb_devices}.
1207
1208@table @option
1209
1210@item mouse
1211Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1212
1213@item tablet
1214Pointer device that uses absolute coordinates (like a touchscreen). This
1215means QEMU is able to report the mouse position without having to grab the
1216mouse. Also overrides the PS/2 mouse emulation when activated.
1217
1218@item disk:[format=@var{format}]:@var{file}
1219Mass storage device based on file. The optional @var{format} argument
1220will be used rather than detecting the format. Can be used to specify
1221@code{format=raw} to avoid interpreting an untrusted format header.
1222
1223@item host:@var{bus}.@var{addr}
1224Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
1225
1226@item host:@var{vendor_id}:@var{product_id}
1227Pass through the host device identified by @var{vendor_id}:@var{product_id}
1228(Linux only).
1229
1230@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
1231Serial converter to host character device @var{dev}, see @code{-serial} for the
1232available devices.
1233
1234@item braille
1235Braille device.  This will use BrlAPI to display the braille output on a real
1236or fake device.
1237
1238@item net:@var{options}
1239Network adapter that supports CDC ethernet and RNDIS protocols.
1240
1241@end table
1242ETEXI
1243
1244STEXI
1245@end table
1246ETEXI
1247DEFHEADING()
1248
1249DEFHEADING(Display options:)
1250STEXI
1251@table @option
1252ETEXI
1253
1254DEF("display", HAS_ARG, QEMU_OPTION_display,
1255    "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
1256    "            [,window_close=on|off][,gl=on|off]\n"
1257    "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
1258    "-display vnc=<display>[,<optargs>]\n"
1259    "-display curses\n"
1260    "-display none"
1261    "                select display type\n"
1262    "The default display is equivalent to\n"
1263#if defined(CONFIG_GTK)
1264            "\t\"-display gtk\"\n"
1265#elif defined(CONFIG_SDL)
1266            "\t\"-display sdl\"\n"
1267#elif defined(CONFIG_COCOA)
1268            "\t\"-display cocoa\"\n"
1269#elif defined(CONFIG_VNC)
1270            "\t\"-vnc localhost:0,to=99,id=default\"\n"
1271#else
1272            "\t\"-display none\"\n"
1273#endif
1274    , QEMU_ARCH_ALL)
1275STEXI
1276@item -display @var{type}
1277@findex -display
1278Select type of display to use. This option is a replacement for the
1279old style -sdl/-curses/... options. Valid values for @var{type} are
1280@table @option
1281@item sdl
1282Display video output via SDL (usually in a separate graphics
1283window; see the SDL documentation for other possibilities).
1284@item curses
1285Display video output via curses. For graphics device models which
1286support a text mode, QEMU can display this output using a
1287curses/ncurses interface. Nothing is displayed when the graphics
1288device is in graphical mode or if the graphics device does not support
1289a text mode. Generally only the VGA device models support text mode.
1290@item none
1291Do not display video output. The guest will still see an emulated
1292graphics card, but its output will not be displayed to the QEMU
1293user. This option differs from the -nographic option in that it
1294only affects what is done with video output; -nographic also changes
1295the destination of the serial and parallel port data.
1296@item gtk
1297Display video output in a GTK window. This interface provides drop-down
1298menus and other UI elements to configure and control the VM during
1299runtime.
1300@item vnc
1301Start a VNC server on display <arg>
1302@end table
1303ETEXI
1304
1305DEF("nographic", 0, QEMU_OPTION_nographic,
1306    "-nographic      disable graphical output and redirect serial I/Os to console\n",
1307    QEMU_ARCH_ALL)
1308STEXI
1309@item -nographic
1310@findex -nographic
1311Normally, if QEMU is compiled with graphical window support, it displays
1312output such as guest graphics, guest console, and the QEMU monitor in a
1313window. With this option, you can totally disable graphical output so
1314that QEMU is a simple command line application. The emulated serial port
1315is redirected on the console and muxed with the monitor (unless
1316redirected elsewhere explicitly). Therefore, you can still use QEMU to
1317debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1318switching between the console and monitor.
1319ETEXI
1320
1321DEF("curses", 0, QEMU_OPTION_curses,
1322    "-curses         shorthand for -display curses\n",
1323    QEMU_ARCH_ALL)
1324STEXI
1325@item -curses
1326@findex -curses
1327Normally, if QEMU is compiled with graphical window support, it displays
1328output such as guest graphics, guest console, and the QEMU monitor in a
1329window. With this option, QEMU can display the VGA output when in text
1330mode using a curses/ncurses interface. Nothing is displayed in graphical
1331mode.
1332ETEXI
1333
1334DEF("no-frame", 0, QEMU_OPTION_no_frame,
1335    "-no-frame       open SDL window without a frame and window decorations\n",
1336    QEMU_ARCH_ALL)
1337STEXI
1338@item -no-frame
1339@findex -no-frame
1340Do not use decorations for SDL windows and start them using the whole
1341available screen space. This makes the using QEMU in a dedicated desktop
1342workspace more convenient.
1343ETEXI
1344
1345DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
1346    "-alt-grab       use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
1347    QEMU_ARCH_ALL)
1348STEXI
1349@item -alt-grab
1350@findex -alt-grab
1351Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1352affects the special keys (for fullscreen, monitor-mode switching, etc).
1353ETEXI
1354
1355DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
1356    "-ctrl-grab      use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
1357    QEMU_ARCH_ALL)
1358STEXI
1359@item -ctrl-grab
1360@findex -ctrl-grab
1361Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1362affects the special keys (for fullscreen, monitor-mode switching, etc).
1363ETEXI
1364
1365DEF("no-quit", 0, QEMU_OPTION_no_quit,
1366    "-no-quit        disable SDL window close capability\n", QEMU_ARCH_ALL)
1367STEXI
1368@item -no-quit
1369@findex -no-quit
1370Disable SDL window close capability.
1371ETEXI
1372
1373DEF("sdl", 0, QEMU_OPTION_sdl,
1374    "-sdl            shorthand for -display sdl\n", QEMU_ARCH_ALL)
1375STEXI
1376@item -sdl
1377@findex -sdl
1378Enable SDL.
1379ETEXI
1380
1381DEF("spice", HAS_ARG, QEMU_OPTION_spice,
1382    "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
1383    "       [,x509-key-file=<file>][,x509-key-password=<file>]\n"
1384    "       [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
1385    "       [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
1386    "       [,tls-ciphers=<list>]\n"
1387    "       [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
1388    "       [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
1389    "       [,sasl][,password=<secret>][,disable-ticketing]\n"
1390    "       [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
1391    "       [,jpeg-wan-compression=[auto|never|always]]\n"
1392    "       [,zlib-glz-wan-compression=[auto|never|always]]\n"
1393    "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
1394    "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
1395    "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
1396    "       [,gl=[on|off]][,rendernode=<file>]\n"
1397    "   enable spice\n"
1398    "   at least one of {port, tls-port} is mandatory\n",
1399    QEMU_ARCH_ALL)
1400STEXI
1401@item -spice @var{option}[,@var{option}[,...]]
1402@findex -spice
1403Enable the spice remote desktop protocol. Valid options are
1404
1405@table @option
1406
1407@item port=<nr>
1408Set the TCP port spice is listening on for plaintext channels.
1409
1410@item addr=<addr>
1411Set the IP address spice is listening on.  Default is any address.
1412
1413@item ipv4
1414@itemx ipv6
1415@itemx unix
1416Force using the specified IP version.
1417
1418@item password=<secret>
1419Set the password you need to authenticate.
1420
1421@item sasl
1422Require that the client use SASL to authenticate with the spice.
1423The exact choice of authentication method used is controlled from the
1424system / user's SASL configuration file for the 'qemu' service. This
1425is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1426unprivileged user, an environment variable SASL_CONF_PATH can be used
1427to make it search alternate locations for the service config.
1428While some SASL auth methods can also provide data encryption (eg GSSAPI),
1429it is recommended that SASL always be combined with the 'tls' and
1430'x509' settings to enable use of SSL and server certificates. This
1431ensures a data encryption preventing compromise of authentication
1432credentials.
1433
1434@item disable-ticketing
1435Allow client connects without authentication.
1436
1437@item disable-copy-paste
1438Disable copy paste between the client and the guest.
1439
1440@item disable-agent-file-xfer
1441Disable spice-vdagent based file-xfer between the client and the guest.
1442
1443@item tls-port=<nr>
1444Set the TCP port spice is listening on for encrypted channels.
1445
1446@item x509-dir=<dir>
1447Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1448
1449@item x509-key-file=<file>
1450@itemx x509-key-password=<file>
1451@itemx x509-cert-file=<file>
1452@itemx x509-cacert-file=<file>
1453@itemx x509-dh-key-file=<file>
1454The x509 file names can also be configured individually.
1455
1456@item tls-ciphers=<list>
1457Specify which ciphers to use.
1458
1459@item tls-channel=[main|display|cursor|inputs|record|playback]
1460@itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1461Force specific channel to be used with or without TLS encryption.  The
1462options can be specified multiple times to configure multiple
1463channels.  The special name "default" can be used to set the default
1464mode.  For channels which are not explicitly forced into one mode the
1465spice client is allowed to pick tls/plaintext as he pleases.
1466
1467@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1468Configure image compression (lossless).
1469Default is auto_glz.
1470
1471@item jpeg-wan-compression=[auto|never|always]
1472@itemx zlib-glz-wan-compression=[auto|never|always]
1473Configure wan image compression (lossy for slow links).
1474Default is auto.
1475
1476@item streaming-video=[off|all|filter]
1477Configure video stream detection.  Default is off.
1478
1479@item agent-mouse=[on|off]
1480Enable/disable passing mouse events via vdagent.  Default is on.
1481
1482@item playback-compression=[on|off]
1483Enable/disable audio stream compression (using celt 0.5.1).  Default is on.
1484
1485@item seamless-migration=[on|off]
1486Enable/disable spice seamless migration. Default is off.
1487
1488@item gl=[on|off]
1489Enable/disable OpenGL context. Default is off.
1490
1491@item rendernode=<file>
1492DRM render node for OpenGL rendering. If not specified, it will pick
1493the first available. (Since 2.9)
1494
1495@end table
1496ETEXI
1497
1498DEF("portrait", 0, QEMU_OPTION_portrait,
1499    "-portrait       rotate graphical output 90 deg left (only PXA LCD)\n",
1500    QEMU_ARCH_ALL)
1501STEXI
1502@item -portrait
1503@findex -portrait
1504Rotate graphical output 90 deg left (only PXA LCD).
1505ETEXI
1506
1507DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1508    "-rotate <deg>   rotate graphical output some deg left (only PXA LCD)\n",
1509    QEMU_ARCH_ALL)
1510STEXI
1511@item -rotate @var{deg}
1512@findex -rotate
1513Rotate graphical output some deg left (only PXA LCD).
1514ETEXI
1515
1516DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1517    "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1518    "                select video card type\n", QEMU_ARCH_ALL)
1519STEXI
1520@item -vga @var{type}
1521@findex -vga
1522Select type of VGA card to emulate. Valid values for @var{type} are
1523@table @option
1524@item cirrus
1525Cirrus Logic GD5446 Video card. All Windows versions starting from
1526Windows 95 should recognize and use this graphic card. For optimal
1527performances, use 16 bit color depth in the guest and the host OS.
1528(This card was the default before QEMU 2.2)
1529@item std
1530Standard VGA card with Bochs VBE extensions.  If your guest OS
1531supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1532to use high resolution modes (>= 1280x1024x16) then you should use
1533this option. (This card is the default since QEMU 2.2)
1534@item vmware
1535VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1536recent XFree86/XOrg server or Windows guest with a driver for this
1537card.
1538@item qxl
1539QXL paravirtual graphic card.  It is VGA compatible (including VESA
15402.0 VBE support).  Works best with qxl guest drivers installed though.
1541Recommended choice when using the spice protocol.
1542@item tcx
1543(sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1544sun4m machines and offers both 8-bit and 24-bit colour depths at a
1545fixed resolution of 1024x768.
1546@item cg3
1547(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1548for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1549resolutions aimed at people wishing to run older Solaris versions.
1550@item virtio
1551Virtio VGA card.
1552@item none
1553Disable VGA card.
1554@end table
1555ETEXI
1556
1557DEF("full-screen", 0, QEMU_OPTION_full_screen,
1558    "-full-screen    start in full screen\n", QEMU_ARCH_ALL)
1559STEXI
1560@item -full-screen
1561@findex -full-screen
1562Start in full screen.
1563ETEXI
1564
1565DEF("g", 1, QEMU_OPTION_g ,
1566    "-g WxH[xDEPTH]  Set the initial graphical resolution and depth\n",
1567    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1568STEXI
1569@item -g @var{width}x@var{height}[x@var{depth}]
1570@findex -g
1571Set the initial graphical resolution and depth (PPC, SPARC only).
1572ETEXI
1573
1574DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1575    "-vnc <display>  shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
1576STEXI
1577@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1578@findex -vnc
1579Normally, if QEMU is compiled with graphical window support, it displays
1580output such as guest graphics, guest console, and the QEMU monitor in a
1581window. With this option, you can have QEMU listen on VNC display
1582@var{display} and redirect the VGA display over the VNC session. It is
1583very useful to enable the usb tablet device when using this option
1584(option @option{-device usb-tablet}). When using the VNC display, you
1585must use the @option{-k} parameter to set the keyboard layout if you are
1586not using en-us. Valid syntax for the @var{display} is
1587
1588@table @option
1589
1590@item to=@var{L}
1591
1592With this option, QEMU will try next available VNC @var{display}s, until the
1593number @var{L}, if the origianlly defined "-vnc @var{display}" is not
1594available, e.g. port 5900+@var{display} is already used by another
1595application. By default, to=0.
1596
1597@item @var{host}:@var{d}
1598
1599TCP connections will only be allowed from @var{host} on display @var{d}.
1600By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1601be omitted in which case the server will accept connections from any host.
1602
1603@item unix:@var{path}
1604
1605Connections will be allowed over UNIX domain sockets where @var{path} is the
1606location of a unix socket to listen for connections on.
1607
1608@item none
1609
1610VNC is initialized but not started. The monitor @code{change} command
1611can be used to later start the VNC server.
1612
1613@end table
1614
1615Following the @var{display} value there may be one or more @var{option} flags
1616separated by commas. Valid options are
1617
1618@table @option
1619
1620@item reverse
1621
1622Connect to a listening VNC client via a ``reverse'' connection. The
1623client is specified by the @var{display}. For reverse network
1624connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1625is a TCP port number, not a display number.
1626
1627@item websocket
1628
1629Opens an additional TCP listening port dedicated to VNC Websocket connections.
1630If a bare @var{websocket} option is given, the Websocket port is
16315700+@var{display}. An alternative port can be specified with the
1632syntax @code{websocket}=@var{port}.
1633
1634If @var{host} is specified connections will only be allowed from this host.
1635It is possible to control the websocket listen address independently, using
1636the syntax @code{websocket}=@var{host}:@var{port}.
1637
1638If no TLS credentials are provided, the websocket connection runs in
1639unencrypted mode. If TLS credentials are provided, the websocket connection
1640requires encrypted client connections.
1641
1642@item password
1643
1644Require that password based authentication is used for client connections.
1645
1646The password must be set separately using the @code{set_password} command in
1647the @ref{pcsys_monitor}. The syntax to change your password is:
1648@code{set_password <protocol> <password>} where <protocol> could be either
1649"vnc" or "spice".
1650
1651If you would like to change <protocol> password expiration, you should use
1652@code{expire_password <protocol> <expiration-time>} where expiration time could
1653be one of the following options: now, never, +seconds or UNIX time of
1654expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1655to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1656date and time).
1657
1658You can also use keywords "now" or "never" for the expiration time to
1659allow <protocol> password to expire immediately or never expire.
1660
1661@item tls-creds=@var{ID}
1662
1663Provides the ID of a set of TLS credentials to use to secure the
1664VNC server. They will apply to both the normal VNC server socket
1665and the websocket socket (if enabled). Setting TLS credentials
1666will cause the VNC server socket to enable the VeNCrypt auth
1667mechanism.  The credentials should have been previously created
1668using the @option{-object tls-creds} argument.
1669
1670The @option{tls-creds} parameter obsoletes the @option{tls},
1671@option{x509}, and @option{x509verify} options, and as such
1672it is not permitted to set both new and old type options at
1673the same time.
1674
1675@item tls
1676
1677Require that client use TLS when communicating with the VNC server. This
1678uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1679attack. It is recommended that this option be combined with either the
1680@option{x509} or @option{x509verify} options.
1681
1682This option is now deprecated in favor of using the @option{tls-creds}
1683argument.
1684
1685@item x509=@var{/path/to/certificate/dir}
1686
1687Valid if @option{tls} is specified. Require that x509 credentials are used
1688for negotiating the TLS session. The server will send its x509 certificate
1689to the client. It is recommended that a password be set on the VNC server
1690to provide authentication of the client when this is used. The path following
1691this option specifies where the x509 certificates are to be loaded from.
1692See the @ref{vnc_security} section for details on generating certificates.
1693
1694This option is now deprecated in favour of using the @option{tls-creds}
1695argument.
1696
1697@item x509verify=@var{/path/to/certificate/dir}
1698
1699Valid if @option{tls} is specified. Require that x509 credentials are used
1700for negotiating the TLS session. The server will send its x509 certificate
1701to the client, and request that the client send its own x509 certificate.
1702The server will validate the client's certificate against the CA certificate,
1703and reject clients when validation fails. If the certificate authority is
1704trusted, this is a sufficient authentication mechanism. You may still wish
1705to set a password on the VNC server as a second authentication layer. The
1706path following this option specifies where the x509 certificates are to
1707be loaded from. See the @ref{vnc_security} section for details on generating
1708certificates.
1709
1710This option is now deprecated in favour of using the @option{tls-creds}
1711argument.
1712
1713@item sasl
1714
1715Require that the client use SASL to authenticate with the VNC server.
1716The exact choice of authentication method used is controlled from the
1717system / user's SASL configuration file for the 'qemu' service. This
1718is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1719unprivileged user, an environment variable SASL_CONF_PATH can be used
1720to make it search alternate locations for the service config.
1721While some SASL auth methods can also provide data encryption (eg GSSAPI),
1722it is recommended that SASL always be combined with the 'tls' and
1723'x509' settings to enable use of SSL and server certificates. This
1724ensures a data encryption preventing compromise of authentication
1725credentials. See the @ref{vnc_security} section for details on using
1726SASL authentication.
1727
1728@item acl
1729
1730Turn on access control lists for checking of the x509 client certificate
1731and SASL party. For x509 certs, the ACL check is made against the
1732certificate's distinguished name. This is something that looks like
1733@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1734made against the username, which depending on the SASL plugin, may
1735include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1736When the @option{acl} flag is set, the initial access list will be
1737empty, with a @code{deny} policy. Thus no one will be allowed to
1738use the VNC server until the ACLs have been loaded. This can be
1739achieved using the @code{acl} monitor command.
1740
1741@item lossy
1742
1743Enable lossy compression methods (gradient, JPEG, ...). If this
1744option is set, VNC client may receive lossy framebuffer updates
1745depending on its encoding settings. Enabling this option can save
1746a lot of bandwidth at the expense of quality.
1747
1748@item non-adaptive
1749
1750Disable adaptive encodings. Adaptive encodings are enabled by default.
1751An adaptive encoding will try to detect frequently updated screen regions,
1752and send updates in these regions using a lossy encoding (like JPEG).
1753This can be really helpful to save bandwidth when playing videos. Disabling
1754adaptive encodings restores the original static behavior of encodings
1755like Tight.
1756
1757@item share=[allow-exclusive|force-shared|ignore]
1758
1759Set display sharing policy.  'allow-exclusive' allows clients to ask
1760for exclusive access.  As suggested by the rfb spec this is
1761implemented by dropping other connections.  Connecting multiple
1762clients in parallel requires all clients asking for a shared session
1763(vncviewer: -shared switch).  This is the default.  'force-shared'
1764disables exclusive client access.  Useful for shared desktop sessions,
1765where you don't want someone forgetting specify -shared disconnect
1766everybody else.  'ignore' completely ignores the shared flag and
1767allows everybody connect unconditionally.  Doesn't conform to the rfb
1768spec but is traditional QEMU behavior.
1769
1770@item key-delay-ms
1771
1772Set keyboard delay, for key down and key up events, in milliseconds.
1773Default is 10.  Keyboards are low-bandwidth devices, so this slowdown
1774can help the device and guest to keep up and not lose events in case
1775events are arriving in bulk.  Possible causes for the latter are flaky
1776network connections, or scripts for automated testing.
1777
1778@end table
1779ETEXI
1780
1781STEXI
1782@end table
1783ETEXI
1784ARCHHEADING(, QEMU_ARCH_I386)
1785
1786ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1787STEXI
1788@table @option
1789ETEXI
1790
1791DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1792    "-win2k-hack     use it when installing Windows 2000 to avoid a disk full bug\n",
1793    QEMU_ARCH_I386)
1794STEXI
1795@item -win2k-hack
1796@findex -win2k-hack
1797Use it when installing Windows 2000 to avoid a disk full bug. After
1798Windows 2000 is installed, you no longer need this option (this option
1799slows down the IDE transfers).
1800ETEXI
1801
1802HXCOMM Deprecated by -rtc
1803DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1804
1805DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1806    "-no-fd-bootchk  disable boot signature checking for floppy disks\n",
1807    QEMU_ARCH_I386)
1808STEXI
1809@item -no-fd-bootchk
1810@findex -no-fd-bootchk
1811Disable boot signature checking for floppy disks in BIOS. May
1812be needed to boot from old floppy disks.
1813ETEXI
1814
1815DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1816           "-no-acpi        disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1817STEXI
1818@item -no-acpi
1819@findex -no-acpi
1820Disable ACPI (Advanced Configuration and Power Interface) support. Use
1821it if your guest OS complains about ACPI problems (PC target machine
1822only).
1823ETEXI
1824
1825DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1826    "-no-hpet        disable HPET\n", QEMU_ARCH_I386)
1827STEXI
1828@item -no-hpet
1829@findex -no-hpet
1830Disable HPET support.
1831ETEXI
1832
1833DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1834    "-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"
1835    "                ACPI table description\n", QEMU_ARCH_I386)
1836STEXI
1837@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}]...]
1838@findex -acpitable
1839Add ACPI table with specified header fields and context from specified files.
1840For file=, take whole ACPI table from the specified files, including all
1841ACPI headers (possible overridden by other options).
1842For data=, only data
1843portion of the table is used, all header information is specified in the
1844command line.
1845If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1846fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1847to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1848spec.
1849ETEXI
1850
1851DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1852    "-smbios file=binary\n"
1853    "                load SMBIOS entry from binary file\n"
1854    "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1855    "              [,uefi=on|off]\n"
1856    "                specify SMBIOS type 0 fields\n"
1857    "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1858    "              [,uuid=uuid][,sku=str][,family=str]\n"
1859    "                specify SMBIOS type 1 fields\n"
1860    "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1861    "              [,asset=str][,location=str]\n"
1862    "                specify SMBIOS type 2 fields\n"
1863    "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1864    "              [,sku=str]\n"
1865    "                specify SMBIOS type 3 fields\n"
1866    "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1867    "              [,asset=str][,part=str]\n"
1868    "                specify SMBIOS type 4 fields\n"
1869    "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1870    "               [,asset=str][,part=str][,speed=%d]\n"
1871    "                specify SMBIOS type 17 fields\n",
1872    QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1873STEXI
1874@item -smbios file=@var{binary}
1875@findex -smbios
1876Load SMBIOS entry from binary file.
1877
1878@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1879Specify SMBIOS type 0 fields
1880
1881@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}]
1882Specify SMBIOS type 1 fields
1883
1884@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}]
1885Specify SMBIOS type 2 fields
1886
1887@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1888Specify SMBIOS type 3 fields
1889
1890@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1891Specify SMBIOS type 4 fields
1892
1893@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}]
1894Specify SMBIOS type 17 fields
1895ETEXI
1896
1897STEXI
1898@end table
1899ETEXI
1900DEFHEADING()
1901
1902DEFHEADING(Network options:)
1903STEXI
1904@table @option
1905ETEXI
1906
1907HXCOMM Legacy slirp options (now moved to -net user):
1908#ifdef CONFIG_SLIRP
1909DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1910DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1911DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1912#ifndef _WIN32
1913DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1914#endif
1915#endif
1916
1917DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1918#ifdef CONFIG_SLIRP
1919    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
1920    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
1921    "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
1922    "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
1923    "         [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1924#ifndef _WIN32
1925                                             "[,smb=dir[,smbserver=addr]]\n"
1926#endif
1927    "                configure a user mode network backend with ID 'str',\n"
1928    "                its DHCP server and optional services\n"
1929#endif
1930#ifdef _WIN32
1931    "-netdev tap,id=str,ifname=name\n"
1932    "                configure a host TAP network backend with ID 'str'\n"
1933#else
1934    "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1935    "         [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1936    "         [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1937    "         [,poll-us=n]\n"
1938    "                configure a host TAP network backend with ID 'str'\n"
1939    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1940    "                use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1941    "                to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1942    "                to deconfigure it\n"
1943    "                use '[down]script=no' to disable script execution\n"
1944    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1945    "                configure it\n"
1946    "                use 'fd=h' to connect to an already opened TAP interface\n"
1947    "                use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1948    "                use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1949    "                default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1950    "                use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1951    "                use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1952    "                use vhost=on to enable experimental in kernel accelerator\n"
1953    "                    (only has effect for virtio guests which use MSIX)\n"
1954    "                use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1955    "                use 'vhostfd=h' to connect to an already opened vhost net device\n"
1956    "                use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1957    "                use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1958    "                use 'poll-us=n' to speciy the maximum number of microseconds that could be\n"
1959    "                spent on busy polling for vhost net\n"
1960    "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1961    "                configure a host TAP network backend with ID 'str' that is\n"
1962    "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1963    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1964#endif
1965#ifdef __linux__
1966    "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1967    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1968    "         [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1969    "         [,rxcookie=rxcookie][,offset=offset]\n"
1970    "                configure a network backend with ID 'str' connected to\n"
1971    "                an Ethernet over L2TPv3 pseudowire.\n"
1972    "                Linux kernel 3.3+ as well as most routers can talk\n"
1973    "                L2TPv3. This transport allows connecting a VM to a VM,\n"
1974    "                VM to a router and even VM to Host. It is a nearly-universal\n"
1975    "                standard (RFC3391). Note - this implementation uses static\n"
1976    "                pre-configured tunnels (same as the Linux kernel).\n"
1977    "                use 'src=' to specify source address\n"
1978    "                use 'dst=' to specify destination address\n"
1979    "                use 'udp=on' to specify udp encapsulation\n"
1980    "                use 'srcport=' to specify source udp port\n"
1981    "                use 'dstport=' to specify destination udp port\n"
1982    "                use 'ipv6=on' to force v6\n"
1983    "                L2TPv3 uses cookies to prevent misconfiguration as\n"
1984    "                well as a weak security measure\n"
1985    "                use 'rxcookie=0x012345678' to specify a rxcookie\n"
1986    "                use 'txcookie=0x012345678' to specify a txcookie\n"
1987    "                use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1988    "                use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1989    "                use 'pincounter=on' to work around broken counter handling in peer\n"
1990    "                use 'offset=X' to add an extra offset between header and data\n"
1991#endif
1992    "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1993    "                configure a network backend to connect to another network\n"
1994    "                using a socket connection\n"
1995    "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1996    "                configure a network backend to connect to a multicast maddr and port\n"
1997    "                use 'localaddr=addr' to specify the host address to send packets from\n"
1998    "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1999    "                configure a network backend to connect to another network\n"
2000    "                using an UDP tunnel\n"
2001#ifdef CONFIG_VDE
2002    "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2003    "                configure a network backend to connect to port 'n' of a vde switch\n"
2004    "                running on host and listening for incoming connections on 'socketpath'.\n"
2005    "                Use group 'groupname' and mode 'octalmode' to change default\n"
2006    "                ownership and permissions for communication port.\n"
2007#endif
2008#ifdef CONFIG_NETMAP
2009    "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
2010    "                attach to the existing netmap-enabled network interface 'name', or to a\n"
2011    "                VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
2012    "                netmap device, defaults to '/dev/netmap')\n"
2013#endif
2014    "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2015    "                configure a vhost-user network, backed by a chardev 'dev'\n"
2016    "-netdev hubport,id=str,hubid=n\n"
2017    "                configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
2018DEF("net", HAS_ARG, QEMU_OPTION_net,
2019    "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
2020    "                old way to create a new NIC and connect it to VLAN 'n'\n"
2021    "                (use the '-device devtype,netdev=str' option if possible instead)\n"
2022    "-net dump[,vlan=n][,file=f][,len=n]\n"
2023    "                dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
2024    "-net none       use it alone to have zero network devices. If no -net option\n"
2025    "                is provided, the default is '-net nic -net user'\n"
2026    "-net ["
2027#ifdef CONFIG_SLIRP
2028    "user|"
2029#endif
2030    "tap|"
2031    "bridge|"
2032#ifdef CONFIG_VDE
2033    "vde|"
2034#endif
2035#ifdef CONFIG_NETMAP
2036    "netmap|"
2037#endif
2038    "socket][,vlan=n][,option][,option][,...]\n"
2039    "                old way to initialize a host network interface\n"
2040    "                (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
2041STEXI
2042@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
2043@findex -net
2044Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
2045= 0 is the default). The NIC is an e1000 by default on the PC
2046target. Optionally, the MAC address can be changed to @var{mac}, the
2047device address set to @var{addr} (PCI cards only),
2048and a @var{name} can be assigned for use in monitor commands.
2049Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
2050that the card should have; this option currently only affects virtio cards; set
2051@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
2052NIC is created.  QEMU can emulate several different models of network card.
2053Valid values for @var{type} are
2054@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
2055@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
2056@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
2057Not all devices are supported on all targets.  Use @code{-net nic,model=help}
2058for a list of available devices for your target.
2059
2060@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
2061@findex -netdev
2062@item -net user[,@var{option}][,@var{option}][,...]
2063Use the user mode network stack which requires no administrator
2064privilege to run. Valid options are:
2065
2066@table @option
2067@item vlan=@var{n}
2068Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
2069
2070@item id=@var{id}
2071@itemx name=@var{name}
2072Assign symbolic name for use in monitor commands.
2073
2074@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
2075be enabled.  If neither is specified both protocols are enabled.
2076
2077@item net=@var{addr}[/@var{mask}]
2078Set IP network address the guest will see. Optionally specify the netmask,
2079either in the form a.b.c.d or as number of valid top-most bits. Default is
208010.0.2.0/24.
2081
2082@item host=@var{addr}
2083Specify the guest-visible address of the host. Default is the 2nd IP in the
2084guest network, i.e. x.x.x.2.
2085
2086@item ipv6-net=@var{addr}[/@var{int}]
2087Set IPv6 network address the guest will see (default is fec0::/64). The
2088network prefix is given in the usual hexadecimal IPv6 address
2089notation. The prefix size is optional, and is given as the number of
2090valid top-most bits (default is 64).
2091
2092@item ipv6-host=@var{addr}
2093Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
2094the guest network, i.e. xxxx::2.
2095
2096@item restrict=on|off
2097If this option is enabled, the guest will be isolated, i.e. it will not be
2098able to contact the host and no guest IP packets will be routed over the host
2099to the outside. This option does not affect any explicitly set forwarding rules.
2100
2101@item hostname=@var{name}
2102Specifies the client hostname reported by the built-in DHCP server.
2103
2104@item dhcpstart=@var{addr}
2105Specify the first of the 16 IPs the built-in DHCP server can assign. Default
2106is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
2107
2108@item dns=@var{addr}
2109Specify the guest-visible address of the virtual nameserver. The address must
2110be different from the host address. Default is the 3rd IP in the guest network,
2111i.e. x.x.x.3.
2112
2113@item ipv6-dns=@var{addr}
2114Specify the guest-visible address of the IPv6 virtual nameserver. The address
2115must be different from the host address. Default is the 3rd IP in the guest
2116network, i.e. xxxx::3.
2117
2118@item dnssearch=@var{domain}
2119Provides an entry for the domain-search list sent by the built-in
2120DHCP server. More than one domain suffix can be transmitted by specifying
2121this option multiple times. If supported, this will cause the guest to
2122automatically try to append the given domain suffix(es) in case a domain name
2123can not be resolved.
2124
2125Example:
2126@example
2127qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
2128@end example
2129
2130@item tftp=@var{dir}
2131When using the user mode network stack, activate a built-in TFTP
2132server. The files in @var{dir} will be exposed as the root of a TFTP server.
2133The TFTP client on the guest must be configured in binary mode (use the command
2134@code{bin} of the Unix TFTP client).
2135
2136@item bootfile=@var{file}
2137When using the user mode network stack, broadcast @var{file} as the BOOTP
2138filename. In conjunction with @option{tftp}, this can be used to network boot
2139a guest from a local directory.
2140
2141Example (using pxelinux):
2142@example
2143qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
2144@end example
2145
2146@item smb=@var{dir}[,smbserver=@var{addr}]
2147When using the user mode network stack, activate a built-in SMB
2148server so that Windows OSes can access to the host files in @file{@var{dir}}
2149transparently. The IP address of the SMB server can be set to @var{addr}. By
2150default the 4th IP in the guest network is used, i.e. x.x.x.4.
2151
2152In the guest Windows OS, the line:
2153@example
215410.0.2.4 smbserver
2155@end example
2156must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
2157or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
2158
2159Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
2160
2161Note that a SAMBA server must be installed on the host OS.
2162QEMU was tested successfully with smbd versions from Red Hat 9,
2163Fedora Core 3 and OpenSUSE 11.x.
2164
2165@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
2166Redirect incoming TCP or UDP connections to the host port @var{hostport} to
2167the guest IP address @var{guestaddr} on guest port @var{guestport}. If
2168@var{guestaddr} is not specified, its value is x.x.x.15 (default first address
2169given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
2170be bound to a specific host interface. If no connection type is set, TCP is
2171used. This option can be given multiple times.
2172
2173For example, to redirect host X11 connection from screen 1 to guest
2174screen 0, use the following:
2175
2176@example
2177# on the host
2178qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
2179# this host xterm should open in the guest X11 server
2180xterm -display :1
2181@end example
2182
2183To redirect telnet connections from host port 5555 to telnet port on
2184the guest, use the following:
2185
2186@example
2187# on the host
2188qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
2189telnet localhost 5555
2190@end example
2191
2192Then when you use on the host @code{telnet localhost 5555}, you
2193connect to the guest telnet server.
2194
2195@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
2196@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
2197Forward guest TCP connections to the IP address @var{server} on port @var{port}
2198to the character device @var{dev} or to a program executed by @var{cmd:command}
2199which gets spawned for each connection. This option can be given multiple times.
2200
2201You can either use a chardev directly and have that one used throughout QEMU's
2202lifetime, like in the following example:
2203
2204@example
2205# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
2206# the guest accesses it
2207qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
2208@end example
2209
2210Or you can execute a command on every TCP connection established by the guest,
2211so that QEMU behaves similar to an inetd process for that virtual server:
2212
2213@example
2214# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
2215# and connect the TCP stream to its stdin/stdout
2216qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
2217@end example
2218
2219@end table
2220
2221Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
2222processed and applied to -net user. Mixing them with the new configuration
2223syntax gives undefined results. Their use for new applications is discouraged
2224as they will be removed from future versions.
2225
2226@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2227@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
2228Connect the host TAP network interface @var{name} to VLAN @var{n}.
2229
2230Use the network script @var{file} to configure it and the network script
2231@var{dfile} to deconfigure it. If @var{name} is not provided, the OS
2232automatically provides one. The default network configure script is
2233@file{/etc/qemu-ifup} and the default network deconfigure script is
2234@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
2235to disable script execution.
2236
2237If running QEMU as an unprivileged user, use the network helper
2238@var{helper} to configure the TAP interface and attach it to the bridge.
2239The default network helper executable is @file{/path/to/qemu-bridge-helper}
2240and the default bridge device is @file{br0}.
2241
2242@option{fd}=@var{h} can be used to specify the handle of an already
2243opened host TAP interface.
2244
2245Examples:
2246
2247@example
2248#launch a QEMU instance with the default network script
2249qemu-system-i386 linux.img -net nic -net tap
2250@end example
2251
2252@example
2253#launch a QEMU instance with two NICs, each one connected
2254#to a TAP device
2255qemu-system-i386 linux.img \
2256                 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
2257                 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
2258@end example
2259
2260@example
2261#launch a QEMU instance with the default network helper to
2262#connect a TAP device to bridge br0
2263qemu-system-i386 linux.img \
2264                 -net nic -net tap,"helper=/path/to/qemu-bridge-helper"
2265@end example
2266
2267@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2268@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
2269Connect a host TAP network interface to a host bridge device.
2270
2271Use the network helper @var{helper} to configure the TAP interface and
2272attach it to the bridge. The default network helper executable is
2273@file{/path/to/qemu-bridge-helper} and the default bridge
2274device is @file{br0}.
2275
2276Examples:
2277
2278@example
2279#launch a QEMU instance with the default network helper to
2280#connect a TAP device to bridge br0
2281qemu-system-i386 linux.img -net bridge -net nic,model=virtio
2282@end example
2283
2284@example
2285#launch a QEMU instance with the default network helper to
2286#connect a TAP device to bridge qemubr0
2287qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
2288@end example
2289
2290@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2291@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2292
2293Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
2294machine using a TCP socket connection. If @option{listen} is
2295specified, QEMU waits for incoming connections on @var{port}
2296(@var{host} is optional). @option{connect} is used to connect to
2297another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2298specifies an already opened TCP socket.
2299
2300Example:
2301@example
2302# launch a first QEMU instance
2303qemu-system-i386 linux.img \
2304                 -net nic,macaddr=52:54:00:12:34:56 \
2305                 -net socket,listen=:1234
2306# connect the VLAN 0 of this instance to the VLAN 0
2307# of the first instance
2308qemu-system-i386 linux.img \
2309                 -net nic,macaddr=52:54:00:12:34:57 \
2310                 -net socket,connect=127.0.0.1:1234
2311@end example
2312
2313@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2314@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2315
2316Create a VLAN @var{n} shared with another QEMU virtual
2317machines using a UDP multicast socket, effectively making a bus for
2318every QEMU with same multicast address @var{maddr} and @var{port}.
2319NOTES:
2320@enumerate
2321@item
2322Several QEMU can be running on different hosts and share same bus (assuming
2323correct multicast setup for these hosts).
2324@item
2325mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2326@url{http://user-mode-linux.sf.net}.
2327@item
2328Use @option{fd=h} to specify an already opened UDP multicast socket.
2329@end enumerate
2330
2331Example:
2332@example
2333# launch one QEMU instance
2334qemu-system-i386 linux.img \
2335                 -net nic,macaddr=52:54:00:12:34:56 \
2336                 -net socket,mcast=230.0.0.1:1234
2337# launch another QEMU instance on same "bus"
2338qemu-system-i386 linux.img \
2339                 -net nic,macaddr=52:54:00:12:34:57 \
2340                 -net socket,mcast=230.0.0.1:1234
2341# launch yet another QEMU instance on same "bus"
2342qemu-system-i386 linux.img \
2343                 -net nic,macaddr=52:54:00:12:34:58 \
2344                 -net socket,mcast=230.0.0.1:1234
2345@end example
2346
2347Example (User Mode Linux compat.):
2348@example
2349# launch QEMU instance (note mcast address selected
2350# is UML's default)
2351qemu-system-i386 linux.img \
2352                 -net nic,macaddr=52:54:00:12:34:56 \
2353                 -net socket,mcast=239.192.168.1:1102
2354# launch UML
2355/path/to/linux ubd0=/path/to/root_fs eth0=mcast
2356@end example
2357
2358Example (send packets from host's 1.2.3.4):
2359@example
2360qemu-system-i386 linux.img \
2361                 -net nic,macaddr=52:54:00:12:34:56 \
2362                 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2363@end example
2364
2365@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}]
2366@itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
2367Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2368protocol to transport Ethernet (and other Layer 2) data frames between
2369two systems. It is present in routers, firewalls and the Linux kernel
2370(from version 3.3 onwards).
2371
2372This transport allows a VM to communicate to another VM, router or firewall directly.
2373
2374@item src=@var{srcaddr}
2375    source address (mandatory)
2376@item dst=@var{dstaddr}
2377    destination address (mandatory)
2378@item udp
2379    select udp encapsulation (default is ip).
2380@item srcport=@var{srcport}
2381    source udp port.
2382@item dstport=@var{dstport}
2383    destination udp port.
2384@item ipv6
2385    force v6, otherwise defaults to v4.
2386@item rxcookie=@var{rxcookie}
2387@itemx txcookie=@var{txcookie}
2388    Cookies are a weak form of security in the l2tpv3 specification.
2389Their function is mostly to prevent misconfiguration. By default they are 32
2390bit.
2391@item cookie64
2392    Set cookie size to 64 bit instead of the default 32
2393@item counter=off
2394    Force a 'cut-down' L2TPv3 with no counter as in
2395draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2396@item pincounter=on
2397    Work around broken counter handling in peer. This may also help on
2398networks which have packet reorder.
2399@item offset=@var{offset}
2400    Add an extra offset between header and data
2401
2402For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2403on the remote Linux host 1.2.3.4:
2404@example
2405# Setup tunnel on linux host using raw ip as encapsulation
2406# on 1.2.3.4
2407ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2408    encap udp udp_sport 16384 udp_dport 16384
2409ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2410    0xFFFFFFFF peer_session_id 0xFFFFFFFF
2411ifconfig vmtunnel0 mtu 1500
2412ifconfig vmtunnel0 up
2413brctl addif br-lan vmtunnel0
2414
2415
2416# on 4.3.2.1
2417# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2418
2419qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2420
2421
2422@end example
2423
2424@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2425@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2426Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2427listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2428and MODE @var{octalmode} to change default ownership and permissions for
2429communication port. This option is only available if QEMU has been compiled
2430with vde support enabled.
2431
2432Example:
2433@example
2434# launch vde switch
2435vde_switch -F -sock /tmp/myswitch
2436# launch QEMU instance
2437qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2438@end example
2439
2440@item -netdev hubport,id=@var{id},hubid=@var{hubid}
2441
2442Create a hub port on QEMU "vlan" @var{hubid}.
2443
2444The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single
2445netdev.  @code{-net} and @code{-device} with parameter @option{vlan} create the
2446required hub automatically.
2447
2448@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2449
2450Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2451be a unix domain socket backed one. The vhost-user uses a specifically defined
2452protocol to pass vhost ioctl replacement messages to an application on the other
2453end of the socket. On non-MSIX guests, the feature can be forced with
2454@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2455be created for multiqueue vhost-user.
2456
2457Example:
2458@example
2459qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2460     -numa node,memdev=mem \
2461     -chardev socket,id=chr0,path=/path/to/socket \
2462     -netdev type=vhost-user,id=net0,chardev=chr0 \
2463     -device virtio-net-pci,netdev=net0
2464@end example
2465
2466@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2467Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2468At most @var{len} bytes (64k by default) per packet are stored. The file format is
2469libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2470Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2471
2472@item -net none
2473Indicate that no network devices should be configured. It is used to
2474override the default configuration (@option{-net nic -net user}) which
2475is activated if no @option{-net} options are provided.
2476ETEXI
2477
2478STEXI
2479@end table
2480ETEXI
2481DEFHEADING()
2482
2483DEFHEADING(Character device options:)
2484STEXI
2485
2486The general form of a character device option is:
2487@table @option
2488ETEXI
2489
2490DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2491    "-chardev help\n"
2492    "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2493    "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2494    "         [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n"
2495    "         [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
2496    "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n"
2497    "         [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
2498    "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2499    "         [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2500    "         [,logfile=PATH][,logappend=on|off]\n"
2501    "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2502    "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2503    "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2504    "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
2505    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2506    "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2507#ifdef _WIN32
2508    "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2509    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2510#else
2511    "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2512    "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
2513#endif
2514#ifdef CONFIG_BRLAPI
2515    "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2516#endif
2517#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2518        || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2519    "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2520    "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2521#endif
2522#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2523    "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2524    "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
2525#endif
2526#if defined(CONFIG_SPICE)
2527    "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2528    "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
2529#endif
2530    , QEMU_ARCH_ALL
2531)
2532
2533STEXI
2534@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2535@findex -chardev
2536Backend is one of:
2537@option{null},
2538@option{socket},
2539@option{udp},
2540@option{msmouse},
2541@option{vc},
2542@option{ringbuf},
2543@option{file},
2544@option{pipe},
2545@option{console},
2546@option{serial},
2547@option{pty},
2548@option{stdio},
2549@option{braille},
2550@option{tty},
2551@option{parallel},
2552@option{parport},
2553@option{spicevmc}.
2554@option{spiceport}.
2555The specific backend will determine the applicable options.
2556
2557Use "-chardev help" to print all available chardev backend types.
2558
2559All devices must have an id, which can be any string up to 127 characters long.
2560It is used to uniquely identify this device in other command line directives.
2561
2562A character device may be used in multiplexing mode by multiple front-ends.
2563Specify @option{mux=on} to enable this mode.
2564A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
2565backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
2566If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2567create a multiplexer with your specified ID, and you can then configure multiple
2568front ends to use that chardev ID for their input/output. Up to four different
2569front ends can be connected to a single multiplexed chardev. (Without
2570multiplexing enabled, a chardev can only be used by a single front end.)
2571For instance you could use this to allow a single stdio chardev to be used by
2572two serial ports and the QEMU monitor:
2573
2574@example
2575-chardev stdio,mux=on,id=char0 \
2576-mon chardev=char0,mode=readline \
2577-serial chardev:char0 \
2578-serial chardev:char0
2579@end example
2580
2581You can have more than one multiplexer in a system configuration; for instance
2582you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2583multiplexed between the QEMU monitor and a parallel port:
2584
2585@example
2586-chardev stdio,mux=on,id=char0 \
2587-mon chardev=char0,mode=readline \
2588-parallel chardev:char0 \
2589-chardev tcp,...,mux=on,id=char1 \
2590-serial chardev:char1 \
2591-serial chardev:char1
2592@end example
2593
2594When you're using a multiplexed character device, some escape sequences are
2595interpreted in the input. @xref{mux_keys, Keys in the character backend
2596multiplexer}.
2597
2598Note that some other command line options may implicitly create multiplexed
2599character backends; for instance @option{-serial mon:stdio} creates a
2600multiplexed stdio backend connected to the serial port and the QEMU monitor,
2601and @option{-nographic} also multiplexes the console and the monitor to
2602stdio.
2603
2604There is currently no support for multiplexing in the other direction
2605(where a single QEMU front end takes input and output from multiple chardevs).
2606
2607Every backend supports the @option{logfile} option, which supplies the path
2608to a file to record all data transmitted via the backend. The @option{logappend}
2609option controls whether the log file will be truncated or appended to when
2610opened.
2611
2612Further options to each backend are described below.
2613
2614@item -chardev null ,id=@var{id}
2615A void device. This device will not emit any data, and will drop any data it
2616receives. The null backend does not take any options.
2617
2618@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2619
2620Create a two-way stream socket, which can be either a TCP or a unix socket. A
2621unix socket will be created if @option{path} is specified. Behaviour is
2622undefined if TCP options are specified for a unix socket.
2623
2624@option{server} specifies that the socket shall be a listening socket.
2625
2626@option{nowait} specifies that QEMU should not block waiting for a client to
2627connect to a listening socket.
2628
2629@option{telnet} specifies that traffic on the socket should interpret telnet
2630escape sequences.
2631
2632@option{reconnect} sets the timeout for reconnecting on non-server sockets when
2633the remote end goes away.  qemu will delay this many seconds and then attempt
2634to reconnect.  Zero disables reconnecting, and is the default.
2635
2636@option{tls-creds} requests enablement of the TLS protocol for encryption,
2637and specifies the id of the TLS credentials to use for the handshake. The
2638credentials must be previously created with the @option{-object tls-creds}
2639argument.
2640
2641TCP and unix socket options are given below:
2642
2643@table @option
2644
2645@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2646
2647@option{host} for a listening socket specifies the local address to be bound.
2648For a connecting socket species the remote host to connect to. @option{host} is
2649optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2650
2651@option{port} for a listening socket specifies the local port to be bound. For a
2652connecting socket specifies the port on the remote host to connect to.
2653@option{port} can be given as either a port number or a service name.
2654@option{port} is required.
2655
2656@option{to} is only relevant to listening sockets. If it is specified, and
2657@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2658to and including @option{to} until it succeeds. @option{to} must be specified
2659as a port number.
2660
2661@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2662If neither is specified the socket may use either protocol.
2663
2664@option{nodelay} disables the Nagle algorithm.
2665
2666@item unix options: path=@var{path}
2667
2668@option{path} specifies the local path of the unix socket. @option{path} is
2669required.
2670
2671@end table
2672
2673@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2674
2675Sends all traffic from the guest to a remote host over UDP.
2676
2677@option{host} specifies the remote host to connect to. If not specified it
2678defaults to @code{localhost}.
2679
2680@option{port} specifies the port on the remote host to connect to. @option{port}
2681is required.
2682
2683@option{localaddr} specifies the local address to bind to. If not specified it
2684defaults to @code{0.0.0.0}.
2685
2686@option{localport} specifies the local port to bind to. If not specified any
2687available local port will be used.
2688
2689@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2690If neither is specified the device may use either protocol.
2691
2692@item -chardev msmouse ,id=@var{id}
2693
2694Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2695take any options.
2696
2697@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2698
2699Connect to a QEMU text console. @option{vc} may optionally be given a specific
2700size.
2701
2702@option{width} and @option{height} specify the width and height respectively of
2703the console, in pixels.
2704
2705@option{cols} and @option{rows} specify that the console be sized to fit a text
2706console with the given dimensions.
2707
2708@item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2709
2710Create a ring buffer with fixed size @option{size}.
2711@var{size} must be a power of two and defaults to @code{64K}.
2712
2713@item -chardev file ,id=@var{id} ,path=@var{path}
2714
2715Log all traffic received from the guest to a file.
2716
2717@option{path} specifies the path of the file to be opened. This file will be
2718created if it does not already exist, and overwritten if it does. @option{path}
2719is required.
2720
2721@item -chardev pipe ,id=@var{id} ,path=@var{path}
2722
2723Create a two-way connection to the guest. The behaviour differs slightly between
2724Windows hosts and other hosts:
2725
2726On Windows, a single duplex pipe will be created at
2727@file{\\.pipe\@option{path}}.
2728
2729On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2730@file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2731received by the guest. Data written by the guest can be read from
2732@file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2733be present.
2734
2735@option{path} forms part of the pipe path as described above. @option{path} is
2736required.
2737
2738@item -chardev console ,id=@var{id}
2739
2740Send traffic from the guest to QEMU's standard output. @option{console} does not
2741take any options.
2742
2743@option{console} is only available on Windows hosts.
2744
2745@item -chardev serial ,id=@var{id} ,path=@option{path}
2746
2747Send traffic from the guest to a serial device on the host.
2748
2749On Unix hosts serial will actually accept any tty device,
2750not only serial lines.
2751
2752@option{path} specifies the name of the serial device to open.
2753
2754@item -chardev pty ,id=@var{id}
2755
2756Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2757not take any options.
2758
2759@option{pty} is not available on Windows hosts.
2760
2761@item -chardev stdio ,id=@var{id} [,signal=on|off]
2762Connect to standard input and standard output of the QEMU process.
2763
2764@option{signal} controls if signals are enabled on the terminal, that includes
2765exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2766default, use @option{signal=off} to disable it.
2767
2768@item -chardev braille ,id=@var{id}
2769
2770Connect to a local BrlAPI server. @option{braille} does not take any options.
2771
2772@item -chardev tty ,id=@var{id} ,path=@var{path}
2773
2774@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2775DragonFlyBSD hosts.  It is an alias for @option{serial}.
2776
2777@option{path} specifies the path to the tty. @option{path} is required.
2778
2779@item -chardev parallel ,id=@var{id} ,path=@var{path}
2780@itemx -chardev parport ,id=@var{id} ,path=@var{path}
2781
2782@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2783
2784Connect to a local parallel port.
2785
2786@option{path} specifies the path to the parallel port device. @option{path} is
2787required.
2788
2789@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2790
2791@option{spicevmc} is only available when spice support is built in.
2792
2793@option{debug} debug level for spicevmc
2794
2795@option{name} name of spice channel to connect to
2796
2797Connect to a spice virtual machine channel, such as vdiport.
2798
2799@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2800
2801@option{spiceport} is only available when spice support is built in.
2802
2803@option{debug} debug level for spicevmc
2804
2805@option{name} name of spice port to connect to
2806
2807Connect to a spice port, allowing a Spice client to handle the traffic
2808identified by a name (preferably a fqdn).
2809ETEXI
2810
2811STEXI
2812@end table
2813ETEXI
2814DEFHEADING()
2815
2816DEFHEADING(Device URL Syntax:)
2817STEXI
2818
2819In addition to using normal file images for the emulated storage devices,
2820QEMU can also use networked resources such as iSCSI devices. These are
2821specified using a special URL syntax.
2822
2823@table @option
2824@item iSCSI
2825iSCSI support allows QEMU to access iSCSI resources directly and use as
2826images for the guest storage. Both disk and cdrom images are supported.
2827
2828Syntax for specifying iSCSI LUNs is
2829``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2830
2831By default qemu will use the iSCSI initiator-name
2832'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2833line or a configuration file.
2834
2835Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2836stalled requests and force a reestablishment of the session. The timeout
2837is specified in seconds. The default is 0 which means no timeout. Libiscsi
28381.15.0 or greater is required for this feature.
2839
2840Example (without authentication):
2841@example
2842qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2843                 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2844                 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2845@end example
2846
2847Example (CHAP username/password via URL):
2848@example
2849qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2850@end example
2851
2852Example (CHAP username/password via environment variables):
2853@example
2854LIBISCSI_CHAP_USERNAME="user" \
2855LIBISCSI_CHAP_PASSWORD="password" \
2856qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2857@end example
2858
2859iSCSI support is an optional feature of QEMU and only available when
2860compiled and linked against libiscsi.
2861ETEXI
2862DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
2863    "-iscsi [user=user][,password=password]\n"
2864    "       [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2865    "       [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2866    "       [,timeout=timeout]\n"
2867    "                iSCSI session parameters\n", QEMU_ARCH_ALL)
2868STEXI
2869
2870iSCSI parameters such as username and password can also be specified via
2871a configuration file. See qemu-doc for more information and examples.
2872
2873@item NBD
2874QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2875as Unix Domain Sockets.
2876
2877Syntax for specifying a NBD device using TCP
2878``nbd:<server-ip>:<port>[:exportname=<export>]''
2879
2880Syntax for specifying a NBD device using Unix Domain Sockets
2881``nbd:unix:<domain-socket>[:exportname=<export>]''
2882
2883
2884Example for TCP
2885@example
2886qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2887@end example
2888
2889Example for Unix Domain Sockets
2890@example
2891qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2892@end example
2893
2894@item SSH
2895QEMU supports SSH (Secure Shell) access to remote disks.
2896
2897Examples:
2898@example
2899qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2900qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2901@end example
2902
2903Currently authentication must be done using ssh-agent.  Other
2904authentication methods may be supported in future.
2905
2906@item Sheepdog
2907Sheepdog is a distributed storage system for QEMU.
2908QEMU supports using either local sheepdog devices or remote networked
2909devices.
2910
2911Syntax for specifying a sheepdog device
2912@example
2913sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2914@end example
2915
2916Example
2917@example
2918qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2919@end example
2920
2921See also @url{https://sheepdog.github.io/sheepdog/}.
2922
2923@item GlusterFS
2924GlusterFS is a user space distributed file system.
2925QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2926TCP, Unix Domain Sockets and RDMA transport protocols.
2927
2928Syntax for specifying a VM disk image on GlusterFS volume is
2929@example
2930
2931URI:
2932gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
2933
2934JSON:
2935'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
2936@                                 "server":[@{"type":"tcp","host":"...","port":"..."@},
2937@                                           @{"type":"unix","socket":"..."@}]@}@}'
2938@end example
2939
2940
2941Example
2942@example
2943URI:
2944qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
2945@                               file.debug=9,file.logfile=/var/log/qemu-gluster.log
2946
2947JSON:
2948qemu-system-x86_64 'json:@{"driver":"qcow2",
2949@                          "file":@{"driver":"gluster",
2950@                                   "volume":"testvol","path":"a.img",
2951@                                   "debug":9,"logfile":"/var/log/qemu-gluster.log",
2952@                                   "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@},
2953@                                             @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}'
2954qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
2955@                                      file.debug=9,file.logfile=/var/log/qemu-gluster.log,
2956@                                      file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
2957@                                      file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
2958@end example
2959
2960See also @url{http://www.gluster.org}.
2961
2962@item HTTP/HTTPS/FTP/FTPS
2963QEMU supports read-only access to files accessed over http(s) and ftp(s).
2964
2965Syntax using a single filename:
2966@example
2967<protocol>://[<username>[:<password>]@@]<host>/<path>
2968@end example
2969
2970where:
2971@table @option
2972@item protocol
2973'http', 'https', 'ftp', or 'ftps'.
2974
2975@item username
2976Optional username for authentication to the remote server.
2977
2978@item password
2979Optional password for authentication to the remote server.
2980
2981@item host
2982Address of the remote server.
2983
2984@item path
2985Path on the remote server, including any query string.
2986@end table
2987
2988The following options are also supported:
2989@table @option
2990@item url
2991The full URL when passing options to the driver explicitly.
2992
2993@item readahead
2994The amount of data to read ahead with each range request to the remote server.
2995This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2996does not have a suffix, it will be assumed to be in bytes. The value must be a
2997multiple of 512 bytes. It defaults to 256k.
2998
2999@item sslverify
3000Whether to verify the remote server's certificate when connecting over SSL. It
3001can have the value 'on' or 'off'. It defaults to 'on'.
3002
3003@item cookie
3004Send this cookie (it can also be a list of cookies separated by ';') with
3005each outgoing request.  Only supported when using protocols such as HTTP
3006which support cookies, otherwise ignored.
3007
3008@item timeout
3009Set the timeout in seconds of the CURL connection. This timeout is the time
3010that CURL waits for a response from the remote server to get the size of the
3011image to be downloaded. If not set, the default timeout of 5 seconds is used.
3012@end table
3013
3014Note that when passing options to qemu explicitly, @option{driver} is the value
3015of <protocol>.
3016
3017Example: boot from a remote Fedora 20 live ISO image
3018@example
3019qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
3020
3021qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
3022@end example
3023
3024Example: boot from a remote Fedora 20 cloud image using a local overlay for
3025writes, copy-on-read, and a readahead of 64k
3026@example
3027qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
3028
3029qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
3030@end example
3031
3032Example: boot from an image stored on a VMware vSphere server with a self-signed
3033certificate using a local overlay for writes, a readahead of 64k and a timeout
3034of 10 seconds.
3035@example
3036qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2
3037
3038qemu-system-x86_64 -drive file=/tmp/test.qcow2
3039@end example
3040ETEXI
3041
3042STEXI
3043@end table
3044ETEXI
3045
3046DEFHEADING(Bluetooth(R) options:)
3047STEXI
3048@table @option
3049ETEXI
3050
3051DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
3052    "-bt hci,null    dumb bluetooth HCI - doesn't respond to commands\n" \
3053    "-bt hci,host[:id]\n" \
3054    "                use host's HCI with the given name\n" \
3055    "-bt hci[,vlan=n]\n" \
3056    "                emulate a standard HCI in virtual scatternet 'n'\n" \
3057    "-bt vhci[,vlan=n]\n" \
3058    "                add host computer to virtual scatternet 'n' using VHCI\n" \
3059    "-bt device:dev[,vlan=n]\n" \
3060    "                emulate a bluetooth device 'dev' in scatternet 'n'\n",
3061    QEMU_ARCH_ALL)
3062STEXI
3063@item -bt hci[...]
3064@findex -bt
3065Defines the function of the corresponding Bluetooth HCI.  -bt options
3066are matched with the HCIs present in the chosen machine type.  For
3067example when emulating a machine with only one HCI built into it, only
3068the first @code{-bt hci[...]} option is valid and defines the HCI's
3069logic.  The Transport Layer is decided by the machine type.  Currently
3070the machines @code{n800} and @code{n810} have one HCI and all other
3071machines have none.
3072
3073@anchor{bt-hcis}
3074The following three types are recognized:
3075
3076@table @option
3077@item -bt hci,null
3078(default) The corresponding Bluetooth HCI assumes no internal logic
3079and will not respond to any HCI commands or emit events.
3080
3081@item -bt hci,host[:@var{id}]
3082(@code{bluez} only) The corresponding HCI passes commands / events
3083to / from the physical HCI identified by the name @var{id} (default:
3084@code{hci0}) on the computer running QEMU.  Only available on @code{bluez}
3085capable systems like Linux.
3086
3087@item -bt hci[,vlan=@var{n}]
3088Add a virtual, standard HCI that will participate in the Bluetooth
3089scatternet @var{n} (default @code{0}).  Similarly to @option{-net}
3090VLANs, devices inside a bluetooth network @var{n} can only communicate
3091with other devices in the same network (scatternet).
3092@end table
3093
3094@item -bt vhci[,vlan=@var{n}]
3095(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
3096to the host bluetooth stack instead of to the emulated target.  This
3097allows the host and target machines to participate in a common scatternet
3098and communicate.  Requires the Linux @code{vhci} driver installed.  Can
3099be used as following:
3100
3101@example
3102qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
3103@end example
3104
3105@item -bt device:@var{dev}[,vlan=@var{n}]
3106Emulate a bluetooth device @var{dev} and place it in network @var{n}
3107(default @code{0}).  QEMU can only emulate one type of bluetooth devices
3108currently:
3109
3110@table @option
3111@item keyboard
3112Virtual wireless keyboard implementing the HIDP bluetooth profile.
3113@end table
3114ETEXI
3115
3116STEXI
3117@end table
3118ETEXI
3119DEFHEADING()
3120
3121#ifdef CONFIG_TPM
3122DEFHEADING(TPM device options:)
3123
3124DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
3125    "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
3126    "                use path to provide path to a character device; default is /dev/tpm0\n"
3127    "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
3128    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
3129    "-tpmdev emulator,id=id,chardev=dev\n"
3130    "                configure the TPM device using chardev backend\n",
3131    QEMU_ARCH_ALL)
3132STEXI
3133
3134The general form of a TPM device option is:
3135@table @option
3136
3137@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
3138@findex -tpmdev
3139Backend type must be either one of the following:
3140@option{passthrough}, @option{emulator}.
3141
3142The specific backend type will determine the applicable options.
3143The @code{-tpmdev} option creates the TPM backend and requires a
3144@code{-device} option that specifies the TPM frontend interface model.
3145
3146Options to each backend are described below.
3147
3148Use 'help' to print all available TPM backend types.
3149@example
3150qemu -tpmdev help
3151@end example
3152
3153@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
3154
3155(Linux-host only) Enable access to the host's TPM using the passthrough
3156driver.
3157
3158@option{path} specifies the path to the host's TPM device, i.e., on
3159a Linux host this would be @code{/dev/tpm0}.
3160@option{path} is optional and by default @code{/dev/tpm0} is used.
3161
3162@option{cancel-path} specifies the path to the host TPM device's sysfs
3163entry allowing for cancellation of an ongoing TPM command.
3164@option{cancel-path} is optional and by default QEMU will search for the
3165sysfs entry to use.
3166
3167Some notes about using the host's TPM with the passthrough driver:
3168
3169The TPM device accessed by the passthrough driver must not be
3170used by any other application on the host.
3171
3172Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
3173the VM's firmware (BIOS/UEFI) will not be able to initialize the
3174TPM again and may therefore not show a TPM-specific menu that would
3175otherwise allow the user to configure the TPM, e.g., allow the user to
3176enable/disable or activate/deactivate the TPM.
3177Further, if TPM ownership is released from within a VM then the host's TPM
3178will get disabled and deactivated. To enable and activate the
3179TPM again afterwards, the host has to be rebooted and the user is
3180required to enter the firmware's menu to enable and activate the TPM.
3181If the TPM is left disabled and/or deactivated most TPM commands will fail.
3182
3183To create a passthrough TPM use the following two options:
3184@example
3185-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
3186@end example
3187Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
3188@code{tpmdev=tpm0} in the device option.
3189
3190@item -tpmdev emulator, id=@var{id}, chardev=@var{dev}
3191
3192(Linux-host only) Enable access to a TPM emulator using Unix domain socket based
3193chardev backend.
3194
3195@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server.
3196
3197To create a TPM emulator backend device with chardev socket backend:
3198@example
3199
3200-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
3201
3202@end example
3203
3204@end table
3205
3206ETEXI
3207
3208DEFHEADING()
3209
3210#endif
3211
3212DEFHEADING(Linux/Multiboot boot specific:)
3213STEXI
3214
3215When using these options, you can use a given Linux or Multiboot
3216kernel without installing it in the disk image. It can be useful
3217for easier testing of various kernels.
3218
3219@table @option
3220ETEXI
3221
3222DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
3223    "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
3224STEXI
3225@item -kernel @var{bzImage}
3226@findex -kernel
3227Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
3228or in multiboot format.
3229ETEXI
3230
3231DEF("append", HAS_ARG, QEMU_OPTION_append, \
3232    "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
3233STEXI
3234@item -append @var{cmdline}
3235@findex -append
3236Use @var{cmdline} as kernel command line
3237ETEXI
3238
3239DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
3240           "-initrd file    use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
3241STEXI
3242@item -initrd @var{file}
3243@findex -initrd
3244Use @var{file} as initial ram disk.
3245
3246@item -initrd "@var{file1} arg=foo,@var{file2}"
3247
3248This syntax is only available with multiboot.
3249
3250Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
3251first module.
3252ETEXI
3253
3254DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
3255    "-dtb    file    use 'file' as device tree image\n", QEMU_ARCH_ALL)
3256STEXI
3257@item -dtb @var{file}
3258@findex -dtb
3259Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3260on boot.
3261ETEXI
3262
3263STEXI
3264@end table
3265ETEXI
3266DEFHEADING()
3267
3268DEFHEADING(Debug/Expert options:)
3269STEXI
3270@table @option
3271ETEXI
3272
3273DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3274    "-fw_cfg [name=]<name>,file=<file>\n"
3275    "                add named fw_cfg entry with contents from file\n"
3276    "-fw_cfg [name=]<name>,string=<str>\n"
3277    "                add named fw_cfg entry with contents from string\n",
3278    QEMU_ARCH_ALL)
3279STEXI
3280
3281@item -fw_cfg [name=]@var{name},file=@var{file}
3282@findex -fw_cfg
3283Add named fw_cfg entry with contents from file @var{file}.
3284
3285@item -fw_cfg [name=]@var{name},string=@var{str}
3286Add named fw_cfg entry with contents from string @var{str}.
3287
3288The terminating NUL character of the contents of @var{str} will not be
3289included as part of the fw_cfg item data. To insert contents with
3290embedded NUL characters, you have to use the @var{file} parameter.
3291
3292The fw_cfg entries are passed by QEMU through to the guest.
3293
3294Example:
3295@example
3296    -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3297@end example
3298creates an fw_cfg entry named opt/com.mycompany/blob with contents
3299from ./my_blob.bin.
3300
3301ETEXI
3302
3303DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
3304    "-serial dev     redirect the serial port to char device 'dev'\n",
3305    QEMU_ARCH_ALL)
3306STEXI
3307@item -serial @var{dev}
3308@findex -serial
3309Redirect the virtual serial port to host character device
3310@var{dev}. The default device is @code{vc} in graphical mode and
3311@code{stdio} in non graphical mode.
3312
3313This option can be used several times to simulate up to 4 serial
3314ports.
3315
3316Use @code{-serial none} to disable all serial ports.
3317
3318Available character devices are:
3319@table @option
3320@item vc[:@var{W}x@var{H}]
3321Virtual console. Optionally, a width and height can be given in pixel with
3322@example
3323vc:800x600
3324@end example
3325It is also possible to specify width or height in characters:
3326@example
3327vc:80Cx24C
3328@end example
3329@item pty
3330[Linux only] Pseudo TTY (a new PTY is automatically allocated)
3331@item none
3332No device is allocated.
3333@item null
3334void device
3335@item chardev:@var{id}
3336Use a named character device defined with the @code{-chardev} option.
3337@item /dev/XXX
3338[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3339parameters are set according to the emulated ones.
3340@item /dev/parport@var{N}
3341[Linux only, parallel port only] Use host parallel port
3342@var{N}. Currently SPP and EPP parallel port features can be used.
3343@item file:@var{filename}
3344Write output to @var{filename}. No character can be read.
3345@item stdio
3346[Unix only] standard input/output
3347@item pipe:@var{filename}
3348name pipe @var{filename}
3349@item COM@var{n}
3350[Windows only] Use host serial port @var{n}
3351@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3352This implements UDP Net Console.
3353When @var{remote_host} or @var{src_ip} are not specified
3354they default to @code{0.0.0.0}.
3355When not using a specified @var{src_port} a random port is automatically chosen.
3356
3357If you just want a simple readonly console you can use @code{netcat} or
3358@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3359@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3360will appear in the netconsole session.
3361
3362If you plan to send characters back via netconsole or you want to stop
3363and start QEMU a lot of times, you should have QEMU use the same
3364source port each time by using something like @code{-serial
3365udp::4555@@:4556} to QEMU. Another approach is to use a patched
3366version of netcat which can listen to a TCP port and send and receive
3367characters via udp.  If you have a patched version of netcat which
3368activates telnet remote echo and single char transfer, then you can
3369use the following options to set up a netcat redirector to allow
3370telnet on port 5555 to access the QEMU port.
3371@table @code
3372@item QEMU Options:
3373-serial udp::4555@@:4556
3374@item netcat options:
3375-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3376@item telnet options:
3377localhost 5555
3378@end table
3379
3380@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3381The TCP Net Console has two modes of operation.  It can send the serial
3382I/O to a location or wait for a connection from a location.  By default
3383the TCP Net Console is sent to @var{host} at the @var{port}.  If you use
3384the @var{server} option QEMU will wait for a client socket application
3385to connect to the port before continuing, unless the @code{nowait}
3386option was specified.  The @code{nodelay} option disables the Nagle buffering
3387algorithm.  The @code{reconnect} option only applies if @var{noserver} is
3388set, if the connection goes down it will attempt to reconnect at the
3389given interval.  If @var{host} is omitted, 0.0.0.0 is assumed. Only
3390one TCP connection at a time is accepted. You can use @code{telnet} to
3391connect to the corresponding character device.
3392@table @code
3393@item Example to send tcp console to 192.168.0.2 port 4444
3394-serial tcp:192.168.0.2:4444
3395@item Example to listen and wait on port 4444 for connection
3396-serial tcp::4444,server
3397@item Example to not wait and listen on ip 192.168.0.100 port 4444
3398-serial tcp:192.168.0.100:4444,server,nowait
3399@end table
3400
3401@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3402The telnet protocol is used instead of raw tcp sockets.  The options
3403work the same as if you had specified @code{-serial tcp}.  The
3404difference is that the port acts like a telnet server or client using
3405telnet option negotiation.  This will also allow you to send the
3406MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3407sequence.  Typically in unix telnet you do it with Control-] and then
3408type "send break" followed by pressing the enter key.
3409
3410@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3411A unix domain socket is used instead of a tcp socket.  The option works the
3412same as if you had specified @code{-serial tcp} except the unix domain socket
3413@var{path} is used for connections.
3414
3415@item mon:@var{dev_string}
3416This is a special option to allow the monitor to be multiplexed onto
3417another serial port.  The monitor is accessed with key sequence of
3418@key{Control-a} and then pressing @key{c}.
3419@var{dev_string} should be any one of the serial devices specified
3420above.  An example to multiplex the monitor onto a telnet server
3421listening on port 4444 would be:
3422@table @code
3423@item -serial mon:telnet::4444,server,nowait
3424@end table
3425When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3426QEMU any more but will be passed to the guest instead.
3427
3428@item braille
3429Braille device.  This will use BrlAPI to display the braille output on a real
3430or fake device.
3431
3432@item msmouse
3433Three button serial mouse. Configure the guest to use Microsoft protocol.
3434@end table
3435ETEXI
3436
3437DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
3438    "-parallel dev   redirect the parallel port to char device 'dev'\n",
3439    QEMU_ARCH_ALL)
3440STEXI
3441@item -parallel @var{dev}
3442@findex -parallel
3443Redirect the virtual parallel port to host device @var{dev} (same
3444devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3445be used to use hardware devices connected on the corresponding host
3446parallel port.
3447
3448This option can be used several times to simulate up to 3 parallel
3449ports.
3450
3451Use @code{-parallel none} to disable all parallel ports.
3452ETEXI
3453
3454DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
3455    "-monitor dev    redirect the monitor to char device 'dev'\n",
3456    QEMU_ARCH_ALL)
3457STEXI
3458@item -monitor @var{dev}
3459@findex -monitor
3460Redirect the monitor to host device @var{dev} (same devices as the
3461serial port).
3462The default device is @code{vc} in graphical mode and @code{stdio} in
3463non graphical mode.
3464Use @code{-monitor none} to disable the default monitor.
3465ETEXI
3466DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
3467    "-qmp dev        like -monitor but opens in 'control' mode\n",
3468    QEMU_ARCH_ALL)
3469STEXI
3470@item -qmp @var{dev}
3471@findex -qmp
3472Like -monitor but opens in 'control' mode.
3473ETEXI
3474DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
3475    "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
3476    QEMU_ARCH_ALL)
3477STEXI
3478@item -qmp-pretty @var{dev}
3479@findex -qmp-pretty
3480Like -qmp but uses pretty JSON formatting.
3481ETEXI
3482
3483DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
3484    "-mon [chardev=]name[,mode=readline|control]\n", QEMU_ARCH_ALL)
3485STEXI
3486@item -mon [chardev=]name[,mode=readline|control]
3487@findex -mon
3488Setup monitor on chardev @var{name}.
3489ETEXI
3490
3491DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
3492    "-debugcon dev   redirect the debug console to char device 'dev'\n",
3493    QEMU_ARCH_ALL)
3494STEXI
3495@item -debugcon @var{dev}
3496@findex -debugcon
3497Redirect the debug console to host device @var{dev} (same devices as the
3498serial port).  The debug console is an I/O port which is typically port
34990xe9; writing to that I/O port sends output to this device.
3500The default device is @code{vc} in graphical mode and @code{stdio} in
3501non graphical mode.
3502ETEXI
3503
3504DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
3505    "-pidfile file   write PID to 'file'\n", QEMU_ARCH_ALL)
3506STEXI
3507@item -pidfile @var{file}
3508@findex -pidfile
3509Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3510from a script.
3511ETEXI
3512
3513DEF("singlestep", 0, QEMU_OPTION_singlestep, \
3514    "-singlestep     always run in singlestep mode\n", QEMU_ARCH_ALL)
3515STEXI
3516@item -singlestep
3517@findex -singlestep
3518Run the emulation in single step mode.
3519ETEXI
3520
3521DEF("S", 0, QEMU_OPTION_S, \
3522    "-S              freeze CPU at startup (use 'c' to start execution)\n",
3523    QEMU_ARCH_ALL)
3524STEXI
3525@item -S
3526@findex -S
3527Do not start CPU at startup (you must type 'c' in the monitor).
3528ETEXI
3529
3530DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
3531    "-realtime [mlock=on|off]\n"
3532    "                run qemu with realtime features\n"
3533    "                mlock=on|off controls mlock support (default: on)\n",
3534    QEMU_ARCH_ALL)
3535STEXI
3536@item -realtime mlock=on|off
3537@findex -realtime
3538Run qemu with realtime features.
3539mlocking qemu and guest memory can be enabled via @option{mlock=on}
3540(enabled by default).
3541ETEXI
3542
3543DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
3544    "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
3545STEXI
3546@item -gdb @var{dev}
3547@findex -gdb
3548Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3549connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3550stdio are reasonable use case. The latter is allowing to start QEMU from
3551within gdb and establish the connection via a pipe:
3552@example
3553(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3554@end example
3555ETEXI
3556
3557DEF("s", 0, QEMU_OPTION_s, \
3558    "-s              shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
3559    QEMU_ARCH_ALL)
3560STEXI
3561@item -s
3562@findex -s
3563Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3564(@pxref{gdb_usage}).
3565ETEXI
3566
3567DEF("d", HAS_ARG, QEMU_OPTION_d, \
3568    "-d item1,...    enable logging of specified items (use '-d help' for a list of log items)\n",
3569    QEMU_ARCH_ALL)
3570STEXI
3571@item -d @var{item1}[,...]
3572@findex -d
3573Enable logging of specified items. Use '-d help' for a list of log items.
3574ETEXI
3575
3576DEF("D", HAS_ARG, QEMU_OPTION_D, \
3577    "-D logfile      output log to logfile (default stderr)\n",
3578    QEMU_ARCH_ALL)
3579STEXI
3580@item -D @var{logfile}
3581@findex -D
3582Output log in @var{logfile} instead of to stderr
3583ETEXI
3584
3585DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
3586    "-dfilter range,..  filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3587    QEMU_ARCH_ALL)
3588STEXI
3589@item -dfilter @var{range1}[,...]
3590@findex -dfilter
3591Filter debug output to that relevant to a range of target addresses. The filter
3592spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3593@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3594addresses and sizes required. For example:
3595@example
3596    -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3597@end example
3598Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3599the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3600block starting at 0xffffffc00005f000.
3601ETEXI
3602
3603DEF("L", HAS_ARG, QEMU_OPTION_L, \
3604    "-L path         set the directory for the BIOS, VGA BIOS and keymaps\n",
3605    QEMU_ARCH_ALL)
3606STEXI
3607@item -L  @var{path}
3608@findex -L
3609Set the directory for the BIOS, VGA BIOS and keymaps.
3610
3611To list all the data directories, use @code{-L help}.
3612ETEXI
3613
3614DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3615    "-bios file      set the filename for the BIOS\n", QEMU_ARCH_ALL)
3616STEXI
3617@item -bios @var{file}
3618@findex -bios
3619Set the filename for the BIOS.
3620ETEXI
3621
3622DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3623    "-enable-kvm     enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3624STEXI
3625@item -enable-kvm
3626@findex -enable-kvm
3627Enable KVM full virtualization support. This option is only available
3628if KVM support is enabled when compiling.
3629ETEXI
3630
3631DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3632    "-enable-hax     enable HAX virtualization support\n", QEMU_ARCH_I386)
3633STEXI
3634@item -enable-hax
3635@findex -enable-hax
3636Enable HAX (Hardware-based Acceleration eXecution) support. This option
3637is only available if HAX support is enabled when compiling. HAX is only
3638applicable to MAC and Windows platform, and thus does not conflict with
3639KVM.
3640ETEXI
3641
3642DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3643    "-xen-domid id   specify xen guest domain id\n", QEMU_ARCH_ALL)
3644DEF("xen-create", 0, QEMU_OPTION_xen_create,
3645    "-xen-create     create domain using xen hypercalls, bypassing xend\n"
3646    "                warning: should not be used when xend is in use\n",
3647    QEMU_ARCH_ALL)
3648DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
3649    "-xen-attach     attach to existing xen domain\n"
3650    "                xend will use this when starting QEMU\n",
3651    QEMU_ARCH_ALL)
3652DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
3653    "-xen-domid-restrict     restrict set of available xen operations\n"
3654    "                        to specified domain id. (Does not affect\n"
3655    "                        xenpv machine type).\n",
3656    QEMU_ARCH_ALL)
3657STEXI
3658@item -xen-domid @var{id}
3659@findex -xen-domid
3660Specify xen guest domain @var{id} (XEN only).
3661@item -xen-create
3662@findex -xen-create
3663Create domain using xen hypercalls, bypassing xend.
3664Warning: should not be used when xend is in use (XEN only).
3665@item -xen-attach
3666@findex -xen-attach
3667Attach to existing xen domain.
3668xend will use this when starting QEMU (XEN only).
3669@findex -xen-domid-restrict
3670Restrict set of available xen operations to specified domain id (XEN only).
3671ETEXI
3672
3673DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3674    "-no-reboot      exit instead of rebooting\n", QEMU_ARCH_ALL)
3675STEXI
3676@item -no-reboot
3677@findex -no-reboot
3678Exit instead of rebooting.
3679ETEXI
3680
3681DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3682    "-no-shutdown    stop before shutdown\n", QEMU_ARCH_ALL)
3683STEXI
3684@item -no-shutdown
3685@findex -no-shutdown
3686Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3687This allows for instance switching to monitor to commit changes to the
3688disk image.
3689ETEXI
3690
3691DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3692    "-loadvm [tag|id]\n" \
3693    "                start right away with a saved state (loadvm in monitor)\n",
3694    QEMU_ARCH_ALL)
3695STEXI
3696@item -loadvm @var{file}
3697@findex -loadvm
3698Start right away with a saved state (@code{loadvm} in monitor)
3699ETEXI
3700
3701#ifndef _WIN32
3702DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3703    "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3704#endif
3705STEXI
3706@item -daemonize
3707@findex -daemonize
3708Daemonize the QEMU process after initialization.  QEMU will not detach from
3709standard IO until it is ready to receive connections on any of its devices.
3710This option is a useful way for external programs to launch QEMU without having
3711to cope with initialization race conditions.
3712ETEXI
3713
3714DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3715    "-option-rom rom load a file, rom, into the option ROM space\n",
3716    QEMU_ARCH_ALL)
3717STEXI
3718@item -option-rom @var{file}
3719@findex -option-rom
3720Load the contents of @var{file} as an option ROM.
3721This option is useful to load things like EtherBoot.
3722ETEXI
3723
3724HXCOMM Silently ignored for compatibility
3725DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3726
3727HXCOMM Options deprecated by -rtc
3728DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3729DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3730
3731DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
3732    "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
3733    "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
3734    QEMU_ARCH_ALL)
3735
3736STEXI
3737
3738@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3739@findex -rtc
3740Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3741UTC or local time, respectively. @code{localtime} is required for correct date in
3742MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3743format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3744
3745By default the RTC is driven by the host system time. This allows using of the
3746RTC as accurate reference clock inside the guest, specifically if the host
3747time is smoothly following an accurate external reference clock, e.g. via NTP.
3748If you want to isolate the guest time from the host, you can set @option{clock}
3749to @code{rt} instead.  To even prevent it from progressing during suspension,
3750you can set it to @code{vm}.
3751
3752Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3753specifically with Windows' ACPI HAL. This option will try to figure out how
3754many timer interrupts were not processed by the Windows guest and will
3755re-inject them.
3756ETEXI
3757
3758DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3759    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3760    "                enable virtual instruction counter with 2^N clock ticks per\n" \
3761    "                instruction, enable aligning the host and virtual clocks\n" \
3762    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
3763STEXI
3764@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3765@findex -icount
3766Enable virtual instruction counter.  The virtual cpu will execute one
3767instruction every 2^@var{N} ns of virtual time.  If @code{auto} is specified
3768then the virtual cpu speed will be automatically adjusted to keep virtual
3769time within a few seconds of real time.
3770
3771When the virtual cpu is sleeping, the virtual time will advance at default
3772speed unless @option{sleep=on|off} is specified.
3773With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3774instantly whenever the virtual cpu goes to sleep mode and will not advance
3775if no timer is enabled. This behavior give deterministic execution times from
3776the guest point of view.
3777
3778Note that while this option can give deterministic behavior, it does not
3779provide cycle accurate emulation.  Modern CPUs contain superscalar out of
3780order cores with complex cache hierarchies.  The number of instructions
3781executed often has little or no correlation with actual performance.
3782
3783@option{align=on} will activate the delay algorithm which will try
3784to synchronise the host clock and the virtual clock. The goal is to
3785have a guest running at the real frequency imposed by the shift option.
3786Whenever the guest clock is behind the host clock and if
3787@option{align=on} is specified then we print a message to the user
3788to inform about the delay.
3789Currently this option does not work when @option{shift} is @code{auto}.
3790Note: The sync algorithm will work for those shift values for which
3791the guest clock runs ahead of the host clock. Typically this happens
3792when the shift value is high (how high depends on the host machine).
3793
3794When @option{rr} option is specified deterministic record/replay is enabled.
3795Replay log is written into @var{filename} file in record mode and
3796read from this file in replay mode.
3797
3798Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3799at the start of execution recording. In replay mode this option is used
3800to load the initial VM state.
3801ETEXI
3802
3803DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3804    "-watchdog model\n" \
3805    "                enable virtual hardware watchdog [default=none]\n",
3806    QEMU_ARCH_ALL)
3807STEXI
3808@item -watchdog @var{model}
3809@findex -watchdog
3810Create a virtual hardware watchdog device.  Once enabled (by a guest
3811action), the watchdog must be periodically polled by an agent inside
3812the guest or else the guest will be restarted. Choose a model for
3813which your guest has drivers.
3814
3815The @var{model} is the model of hardware watchdog to emulate. Use
3816@code{-watchdog help} to list available hardware models. Only one
3817watchdog can be enabled for a guest.
3818
3819The following models may be available:
3820@table @option
3821@item ib700
3822iBASE 700 is a very simple ISA watchdog with a single timer.
3823@item i6300esb
3824Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3825dual-timer watchdog.
3826@item diag288
3827A virtual watchdog for s390x backed by the diagnose 288 hypercall
3828(currently KVM only).
3829@end table
3830ETEXI
3831
3832DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3833    "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3834    "                action when watchdog fires [default=reset]\n",
3835    QEMU_ARCH_ALL)
3836STEXI
3837@item -watchdog-action @var{action}
3838@findex -watchdog-action
3839
3840The @var{action} controls what QEMU will do when the watchdog timer
3841expires.
3842The default is
3843@code{reset} (forcefully reset the guest).
3844Other possible actions are:
3845@code{shutdown} (attempt to gracefully shutdown the guest),
3846@code{poweroff} (forcefully poweroff the guest),
3847@code{pause} (pause the guest),
3848@code{debug} (print a debug message and continue), or
3849@code{none} (do nothing).
3850
3851Note that the @code{shutdown} action requires that the guest responds
3852to ACPI signals, which it may not be able to do in the sort of
3853situations where the watchdog would have expired, and thus
3854@code{-watchdog-action shutdown} is not recommended for production use.
3855
3856Examples:
3857
3858@table @code
3859@item -watchdog i6300esb -watchdog-action pause
3860@itemx -watchdog ib700
3861@end table
3862ETEXI
3863
3864DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3865    "-echr chr       set terminal escape character instead of ctrl-a\n",
3866    QEMU_ARCH_ALL)
3867STEXI
3868
3869@item -echr @var{numeric_ascii_value}
3870@findex -echr
3871Change the escape character used for switching to the monitor when using
3872monitor and serial sharing.  The default is @code{0x01} when using the
3873@code{-nographic} option.  @code{0x01} is equal to pressing
3874@code{Control-a}.  You can select a different character from the ascii
3875control keys where 1 through 26 map to Control-a through Control-z.  For
3876instance you could use the either of the following to change the escape
3877character to Control-t.
3878@table @code
3879@item -echr 0x14
3880@itemx -echr 20
3881@end table
3882ETEXI
3883
3884DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3885    "-virtioconsole c\n" \
3886    "                set virtio console\n", QEMU_ARCH_ALL)
3887STEXI
3888@item -virtioconsole @var{c}
3889@findex -virtioconsole
3890Set virtio console.
3891
3892This option is maintained for backward compatibility.
3893
3894Please use @code{-device virtconsole} for the new way of invocation.
3895ETEXI
3896
3897DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3898    "-show-cursor    show cursor\n", QEMU_ARCH_ALL)
3899STEXI
3900@item -show-cursor
3901@findex -show-cursor
3902Show cursor.
3903ETEXI
3904
3905DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3906    "-tb-size n      set TB size\n", QEMU_ARCH_ALL)
3907STEXI
3908@item -tb-size @var{n}
3909@findex -tb-size
3910Set TB size.
3911ETEXI
3912
3913DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3914    "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3915    "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3916    "-incoming unix:socketpath\n" \
3917    "                prepare for incoming migration, listen on\n" \
3918    "                specified protocol and socket address\n" \
3919    "-incoming fd:fd\n" \
3920    "-incoming exec:cmdline\n" \
3921    "                accept incoming migration on given file descriptor\n" \
3922    "                or from given external command\n" \
3923    "-incoming defer\n" \
3924    "                wait for the URI to be specified via migrate_incoming\n",
3925    QEMU_ARCH_ALL)
3926STEXI
3927@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3928@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3929@findex -incoming
3930Prepare for incoming migration, listen on a given tcp port.
3931
3932@item -incoming unix:@var{socketpath}
3933Prepare for incoming migration, listen on a given unix socket.
3934
3935@item -incoming fd:@var{fd}
3936Accept incoming migration from a given filedescriptor.
3937
3938@item -incoming exec:@var{cmdline}
3939Accept incoming migration as an output from specified external command.
3940
3941@item -incoming defer
3942Wait for the URI to be specified via migrate_incoming.  The monitor can
3943be used to change settings (such as migration parameters) prior to issuing
3944the migrate_incoming to allow the migration to begin.
3945ETEXI
3946
3947DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
3948    "-only-migratable     allow only migratable devices\n", QEMU_ARCH_ALL)
3949STEXI
3950@item -only-migratable
3951@findex -only-migratable
3952Only allow migratable devices. Devices will not be allowed to enter an
3953unmigratable state.
3954ETEXI
3955
3956DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3957    "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
3958STEXI
3959@item -nodefaults
3960@findex -nodefaults
3961Don't create default devices. Normally, QEMU sets the default devices like serial
3962port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3963CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3964default devices.
3965ETEXI
3966
3967#ifndef _WIN32
3968DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3969    "-chroot dir     chroot to dir just before starting the VM\n",
3970    QEMU_ARCH_ALL)
3971#endif
3972STEXI
3973@item -chroot @var{dir}
3974@findex -chroot
3975Immediately before starting guest execution, chroot to the specified
3976directory.  Especially useful in combination with -runas.
3977ETEXI
3978
3979#ifndef _WIN32
3980DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3981    "-runas user     change to user id user just before starting the VM\n",
3982    QEMU_ARCH_ALL)
3983#endif
3984STEXI
3985@item -runas @var{user}
3986@findex -runas
3987Immediately before starting guest execution, drop root privileges, switching
3988to the specified user.
3989ETEXI
3990
3991DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3992    "-prom-env variable=value\n"
3993    "                set OpenBIOS nvram variables\n",
3994    QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3995STEXI
3996@item -prom-env @var{variable}=@var{value}
3997@findex -prom-env
3998Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3999ETEXI
4000DEF("semihosting", 0, QEMU_OPTION_semihosting,
4001    "-semihosting    semihosting mode\n",
4002    QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
4003    QEMU_ARCH_MIPS)
4004STEXI
4005@item -semihosting
4006@findex -semihosting
4007Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
4008ETEXI
4009DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
4010    "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
4011    "                semihosting configuration\n",
4012QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
4013QEMU_ARCH_MIPS)
4014STEXI
4015@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
4016@findex -semihosting-config
4017Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
4018@table @option
4019@item target=@code{native|gdb|auto}
4020Defines where the semihosting calls will be addressed, to QEMU (@code{native})
4021or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
4022during debug sessions and @code{native} otherwise.
4023@item arg=@var{str1},arg=@var{str2},...
4024Allows the user to pass input arguments, and can be used multiple times to build
4025up a list. The old-style @code{-kernel}/@code{-append} method of passing a
4026command line is still supported for backward compatibility. If both the
4027@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
4028specified, the former is passed to semihosting as it always takes precedence.
4029@end table
4030ETEXI
4031DEF("old-param", 0, QEMU_OPTION_old_param,
4032    "-old-param      old param mode\n", QEMU_ARCH_ARM)
4033STEXI
4034@item -old-param
4035@findex -old-param (ARM)
4036Old param mode (ARM only).
4037ETEXI
4038
4039DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
4040    "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
4041    "          [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
4042    "                Enable seccomp mode 2 system call filter (default 'off').\n" \
4043    "                use 'obsolete' to allow obsolete system calls that are provided\n" \
4044    "                    by the kernel, but typically no longer used by modern\n" \
4045    "                    C library implementations.\n" \
4046    "                use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \
4047    "                    its privileges by blacklisting all set*uid|gid system calls.\n" \
4048    "                    The value 'children' will deny set*uid|gid system calls for\n" \
4049    "                    main QEMU process but will allow forks and execves to run unprivileged\n" \
4050    "                use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
4051    "                     blacklisting *fork and execve\n" \
4052    "                use 'resourcecontrol' to disable process affinity and schedular priority\n",
4053    QEMU_ARCH_ALL)
4054STEXI
4055@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
4056@findex -sandbox
4057Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
4058disable it.  The default is 'off'.
4059@table @option
4060@item obsolete=@var{string}
4061Enable Obsolete system calls
4062@item elevateprivileges=@var{string}
4063Disable set*uid|gid system calls
4064@item spawn=@var{string}
4065Disable *fork and execve
4066@item resourcecontrol=@var{string}
4067Disable process affinity and schedular priority
4068@end table
4069ETEXI
4070
4071DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
4072    "-readconfig <file>\n", QEMU_ARCH_ALL)
4073STEXI
4074@item -readconfig @var{file}
4075@findex -readconfig
4076Read device configuration from @var{file}. This approach is useful when you want to spawn
4077QEMU process with many command line options but you don't want to exceed the command line
4078character limit.
4079ETEXI
4080DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
4081    "-writeconfig <file>\n"
4082    "                read/write config file\n", QEMU_ARCH_ALL)
4083STEXI
4084@item -writeconfig @var{file}
4085@findex -writeconfig
4086Write device configuration to @var{file}. The @var{file} can be either filename to save
4087command line and device configuration into file or dash @code{-}) character to print the
4088output to stdout. This can be later used as input file for @code{-readconfig} option.
4089ETEXI
4090HXCOMM Deprecated, same as -no-user-config
4091DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL)
4092DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
4093    "-no-user-config\n"
4094    "                do not load default user-provided config files at startup\n",
4095    QEMU_ARCH_ALL)
4096STEXI
4097@item -no-user-config
4098@findex -no-user-config
4099The @code{-no-user-config} option makes QEMU not load any of the user-provided
4100config files on @var{sysconfdir}.
4101ETEXI
4102DEF("trace", HAS_ARG, QEMU_OPTION_trace,
4103    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
4104    "                specify tracing options\n",
4105    QEMU_ARCH_ALL)
4106STEXI
4107HXCOMM This line is not accurate, as some sub-options are backend-specific but
4108HXCOMM HX does not support conditional compilation of text.
4109@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
4110@findex -trace
4111@include qemu-option-trace.texi
4112ETEXI
4113
4114HXCOMM Internal use
4115DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
4116DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
4117
4118#ifdef __linux__
4119DEF("enable-fips", 0, QEMU_OPTION_enablefips,
4120    "-enable-fips    enable FIPS 140-2 compliance\n",
4121    QEMU_ARCH_ALL)
4122#endif
4123STEXI
4124@item -enable-fips
4125@findex -enable-fips
4126Enable FIPS 140-2 compliance mode.
4127ETEXI
4128
4129HXCOMM Deprecated by -machine accel=tcg property
4130DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
4131
4132HXCOMM Deprecated by kvm-pit driver properties
4133DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
4134    "", QEMU_ARCH_I386)
4135
4136HXCOMM Deprecated (ignored)
4137DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
4138
4139HXCOMM Deprecated by -machine kernel_irqchip=on|off property
4140DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
4141
4142HXCOMM Deprecated (ignored)
4143DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
4144
4145DEF("msg", HAS_ARG, QEMU_OPTION_msg,
4146    "-msg timestamp[=on|off]\n"
4147    "                change the format of messages\n"
4148    "                on|off controls leading timestamps (default:on)\n",
4149    QEMU_ARCH_ALL)
4150STEXI
4151@item -msg timestamp[=on|off]
4152@findex -msg
4153prepend a timestamp to each log message.(default:on)
4154ETEXI
4155
4156DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
4157    "-dump-vmstate <file>\n"
4158    "                Output vmstate information in JSON format to file.\n"
4159    "                Use the scripts/vmstate-static-checker.py file to\n"
4160    "                check for possible regressions in migration code\n"
4161    "                by comparing two such vmstate dumps.\n",
4162    QEMU_ARCH_ALL)
4163STEXI
4164@item -dump-vmstate @var{file}
4165@findex -dump-vmstate
4166Dump json-encoded vmstate information for current machine type to file
4167in @var{file}
4168ETEXI
4169
4170STEXI
4171@end table
4172ETEXI
4173DEFHEADING()
4174
4175DEFHEADING(Generic object creation:)
4176STEXI
4177@table @option
4178ETEXI
4179
4180DEF("object", HAS_ARG, QEMU_OPTION_object,
4181    "-object TYPENAME[,PROP1=VALUE1,...]\n"
4182    "                create a new object of type TYPENAME setting properties\n"
4183    "                in the order they are specified.  Note that the 'id'\n"
4184    "                property must be set.  These objects are placed in the\n"
4185    "                '/objects' path.\n",
4186    QEMU_ARCH_ALL)
4187STEXI
4188@item -object @var{typename}[,@var{prop1}=@var{value1},...]
4189@findex -object
4190Create a new object of type @var{typename} setting properties
4191in the order they are specified.  Note that the 'id'
4192property must be set.  These objects are placed in the
4193'/objects' path.
4194
4195@table @option
4196
4197@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off}
4198
4199Creates a memory file backend object, which can be used to back
4200the guest RAM with huge pages. The @option{id} parameter is a
4201unique ID that will be used to reference this memory region
4202when configuring the @option{-numa} argument. The @option{size}
4203option provides the size of the memory region, and accepts
4204common suffixes, eg @option{500M}. The @option{mem-path} provides
4205the path to either a shared memory or huge page filesystem mount.
4206The @option{share} boolean option determines whether the memory
4207region is marked as private to QEMU, or shared. The latter allows
4208a co-operating external process to access the QEMU memory region.
4209Setting the @option{discard-data} boolean option to @var{on}
4210indicates that file contents can be destroyed when QEMU exits,
4211to avoid unnecessarily flushing data to the backing file.  Note
4212that @option{discard-data} is only an optimization, and QEMU
4213might not discard file contents if it aborts unexpectedly or is
4214terminated using SIGKILL.
4215
4216@item -object rng-random,id=@var{id},filename=@var{/dev/random}
4217
4218Creates a random number generator backend which obtains entropy from
4219a device on the host. The @option{id} parameter is a unique ID that
4220will be used to reference this entropy backend from the @option{virtio-rng}
4221device. The @option{filename} parameter specifies which file to obtain
4222entropy from and if omitted defaults to @option{/dev/random}.
4223
4224@item -object rng-egd,id=@var{id},chardev=@var{chardevid}
4225
4226Creates a random number generator backend which obtains entropy from
4227an external daemon running on the host. The @option{id} parameter is
4228a unique ID that will be used to reference this entropy backend from
4229the @option{virtio-rng} device. The @option{chardev} parameter is
4230the unique ID of a character device backend that provides the connection
4231to the RNG daemon.
4232
4233@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
4234
4235Creates a TLS anonymous credentials object, which can be used to provide
4236TLS support on network backends. The @option{id} parameter is a unique
4237ID which network backends will use to access the credentials. The
4238@option{endpoint} is either @option{server} or @option{client} depending
4239on whether the QEMU network backend that uses the credentials will be
4240acting as a client or as a server. If @option{verify-peer} is enabled
4241(the default) then once the handshake is completed, the peer credentials
4242will be verified, though this is a no-op for anonymous credentials.
4243
4244The @var{dir} parameter tells QEMU where to find the credential
4245files. For server endpoints, this directory may contain a file
4246@var{dh-params.pem} providing diffie-hellman parameters to use
4247for the TLS server. If the file is missing, QEMU will generate
4248a set of DH parameters at startup. This is a computationally
4249expensive operation that consumes random pool entropy, so it is
4250recommended that a persistent set of parameters be generated
4251upfront and saved.
4252
4253@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off},passwordid=@var{id}
4254
4255Creates a TLS anonymous credentials object, which can be used to provide
4256TLS support on network backends. The @option{id} parameter is a unique
4257ID which network backends will use to access the credentials. The
4258@option{endpoint} is either @option{server} or @option{client} depending
4259on whether the QEMU network backend that uses the credentials will be
4260acting as a client or as a server. If @option{verify-peer} is enabled
4261(the default) then once the handshake is completed, the peer credentials
4262will be verified. With x509 certificates, this implies that the clients
4263must be provided with valid client certificates too.
4264
4265The @var{dir} parameter tells QEMU where to find the credential
4266files. For server endpoints, this directory may contain a file
4267@var{dh-params.pem} providing diffie-hellman parameters to use
4268for the TLS server. If the file is missing, QEMU will generate
4269a set of DH parameters at startup. This is a computationally
4270expensive operation that consumes random pool entropy, so it is
4271recommended that a persistent set of parameters be generated
4272upfront and saved.
4273
4274For x509 certificate credentials the directory will contain further files
4275providing the x509 certificates. The certificates must be stored
4276in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional),
4277@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers),
4278@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients).
4279
4280For the @var{server-key.pem} and @var{client-key.pem} files which
4281contain sensitive private keys, it is possible to use an encrypted
4282version by providing the @var{passwordid} parameter. This provides
4283the ID of a previously created @code{secret} object containing the
4284password for decryption.
4285
4286@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4287
4288Interval @var{t} can't be 0, this filter batches the packet delivery: all
4289packets arriving in a given interval on netdev @var{netdevid} are delayed
4290until the end of the interval. Interval is in microseconds.
4291@option{status} is optional that indicate whether the netfilter is
4292on (enabled) or off (disabled), the default status for netfilter will be 'on'.
4293
4294queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4295
4296@option{all}: the filter is attached both to the receive and the transmit
4297              queue of the netdev (default).
4298
4299@option{rx}: the filter is attached to the receive queue of the netdev,
4300             where it will receive packets sent to the netdev.
4301
4302@option{tx}: the filter is attached to the transmit queue of the netdev,
4303             where it will receive packets sent by the netdev.
4304
4305@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4306
4307filter-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.
4308
4309@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
4310
4311filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4312@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
4313filter-redirector will redirect packet with vnet_hdr_len.
4314Create a filter-redirector we need to differ outdev id from indev id, id can not
4315be the same. we can just use indev or outdev, but at least one of indev or outdev
4316need to be specified.
4317
4318@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
4319
4320Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4321secondary from primary to keep secondary tcp connection,and rewrite
4322tcp packet to primary from secondary make tcp packet can be handled by
4323client.if it has the vnet_hdr_support flag, we can parse packet with vnet header.
4324
4325usage:
4326colo secondary:
4327-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4328-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4329-object filter-rewriter,id=rew0,netdev=hn0,queue=all
4330
4331@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4332
4333Dump the network traffic on netdev @var{dev} to the file specified by
4334@var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4335The file format is libpcap, so it can be analyzed with tools such as tcpdump
4336or Wireshark.
4337
4338@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support]
4339
4340Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4341secondary packet. If the packets are same, we will output primary
4342packet to outdev@var{chardevid}, else we will notify colo-frame
4343do checkpoint and send primary packet to outdev@var{chardevid}.
4344if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len.
4345
4346we must use it with the help of filter-mirror and filter-redirector.
4347
4348@example
4349
4350primary:
4351-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4352-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4353-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4354-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4355-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4356-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4357-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4358-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4359-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4360-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4361-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4362-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4363
4364secondary:
4365-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4366-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4367-chardev socket,id=red0,host=3.3.3.3,port=9003
4368-chardev socket,id=red1,host=3.3.3.3,port=9004
4369-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4370-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4371
4372@end example
4373
4374If you want to know the detail of above command line, you can read
4375the colo-compare git log.
4376
4377@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4378
4379Creates a cryptodev backend which executes crypto opreation from
4380the QEMU cipher APIS. The @var{id} parameter is
4381a unique ID that will be used to reference this cryptodev backend from
4382the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4383which specify the queue number of cryptodev backend, the default of
4384@var{queues} is 1.
4385
4386@example
4387
4388 # qemu-system-x86_64 \
4389   [...] \
4390       -object cryptodev-backend-builtin,id=cryptodev0 \
4391       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4392   [...]
4393@end example
4394
4395@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4396@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4397
4398Defines a secret to store a password, encryption key, or some other sensitive
4399data. The sensitive data can either be passed directly via the @var{data}
4400parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4401parameter is insecure unless the sensitive data is encrypted.
4402
4403The sensitive data can be provided in raw format (the default), or base64.
4404When encoded as JSON, the raw format only supports valid UTF-8 characters,
4405so base64 is recommended for sending binary data. QEMU will convert from
4406which ever format is provided to the format it needs internally. eg, an
4407RBD password can be provided in raw format, even though it will be base64
4408encoded when passed onto the RBD sever.
4409
4410For added protection, it is possible to encrypt the data associated with
4411a secret using the AES-256-CBC cipher. Use of encryption is indicated
4412by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4413parameter provides the ID of a previously defined secret that contains
4414the AES-256 decryption key. This key should be 32-bytes long and be
4415base64 encoded. The @var{iv} parameter provides the random initialization
4416vector used for encryption of this particular secret and should be a
4417base64 encrypted string of the 16-byte IV.
4418
4419The simplest (insecure) usage is to provide the secret inline
4420
4421@example
4422
4423 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4424
4425@end example
4426
4427The simplest secure usage is to provide the secret via a file
4428
4429 # printf "letmein" > mypasswd.txt
4430 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4431
4432For greater security, AES-256-CBC should be used. To illustrate usage,
4433consider the openssl command line tool which can encrypt the data. Note
4434that when encrypting, the plaintext must be padded to the cipher block
4435size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4436
4437First a master key needs to be created in base64 encoding:
4438
4439@example
4440 # openssl rand -base64 32 > key.b64
4441 # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')
4442@end example
4443
4444Each secret to be encrypted needs to have a random initialization vector
4445generated. These do not need to be kept secret
4446
4447@example
4448 # openssl rand -base64 16 > iv.b64
4449 # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')
4450@end example
4451
4452The secret to be defined can now be encrypted, in this case we're
4453telling openssl to base64 encode the result, but it could be left
4454as raw bytes if desired.
4455
4456@example
4457 # SECRET=$(printf "letmein" |
4458            openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
4459@end example
4460
4461When launching QEMU, create a master secret pointing to @code{key.b64}
4462and specify that to be used to decrypt the user password. Pass the
4463contents of @code{iv.b64} to the second secret
4464
4465@example
4466 # $QEMU \
4467     -object secret,id=secmaster0,format=base64,file=key.b64 \
4468     -object secret,id=sec0,keyid=secmaster0,format=base64,\
4469         data=$SECRET,iv=$(<iv.b64)
4470@end example
4471
4472@end table
4473
4474ETEXI
4475
4476
4477HXCOMM This is the last statement. Insert new options before this line!
4478STEXI
4479@end table
4480ETEXI
4481