1HXCOMM Use DEFHEADING() to define headings in both help text and texi 2HXCOMM Text between STEXI and ETEXI are copied to texi version and 3HXCOMM discarded from C version 4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to 5HXCOMM construct option structures, enums and help message for specified 6HXCOMM architectures. 7HXCOMM HXCOMM can be used for comments, discarded from both texi and C 8 9DEFHEADING(Standard options:) 10STEXI 11@table @option 12ETEXI 13 14DEF("help", 0, QEMU_OPTION_h, 15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 16STEXI 17@item -h 18@findex -h 19Display help and exit 20ETEXI 21 22DEF("version", 0, QEMU_OPTION_version, 23 "-version display version information and exit\n", QEMU_ARCH_ALL) 24STEXI 25@item -version 26@findex -version 27Display version information and exit 28ETEXI 29 30DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 31 "-machine [type=]name[,prop[=value][,...]]\n" 32 " selects emulated machine ('-machine help' for list)\n" 33 " property accel=accel1[:accel2[:...]] selects accelerator\n" 34 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n" 35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" 36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n" 38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 39 " mem-merge=on|off controls memory merge support (default: on)\n" 40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 44 " nvdimm=on|off controls NVDIMM support (default=off)\n" 45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 46 " memory-encryption=@var{} memory encryption object to use (default=none)\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, hvf, whpx 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 enforce-config-section=on|off 99If @option{enforce-config-section} is set to @var{on}, force migration 100code to send configuration section even if the machine-type sets the 101@option{migration.send-configuration} property to @var{off}. 102NOTE: this parameter is deprecated. Please use @option{-global} 103@option{migration.send-configuration}=@var{on|off} instead. 104@item memory-encryption=@var{} 105Memory encryption object to use. The default is none. 106@end table 107ETEXI 108 109HXCOMM Deprecated by -machine 110DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 111 112DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 114STEXI 115@item -cpu @var{model} 116@findex -cpu 117Select CPU model (@code{-cpu help} for list and additional feature selection) 118ETEXI 119 120DEF("accel", HAS_ARG, QEMU_OPTION_accel, 121 "-accel [accel=]accelerator[,thread=single|multi]\n" 122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 123 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 124STEXI 125@item -accel @var{name}[,prop=@var{value}[,...]] 126@findex -accel 127This is used to enable an accelerator. Depending on the target architecture, 128kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 129more than one accelerator specified, the next one is used if the previous one 130fails to initialize. 131@table @option 132@item thread=single|multi 133Controls number of TCG threads. When the TCG is multi-threaded there will be one 134thread per vCPU therefor taking advantage of additional host cores. The default 135is to enable multi-threading where both the back-end and front-ends support it and 136no incompatible TCG features have been enabled (e.g. icount/replay). 137@end table 138ETEXI 139 140DEF("smp", HAS_ARG, QEMU_OPTION_smp, 141 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n" 142 " set the number of CPUs to 'n' [default=1]\n" 143 " maxcpus= maximum number of total cpus, including\n" 144 " offline CPUs for hotplug, etc\n" 145 " cores= number of CPU cores on one socket (for PC, it's on one die)\n" 146 " threads= number of threads on one CPU core\n" 147 " dies= number of CPU dies on one socket (for PC only)\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}][,dies=dies][,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 die, the number of @var{threads} 157per cores, the number of @var{dies} per packages and the total number of 158@var{sockets} can be specified. Missing values will be computed. 159If any on the three values is given, the total number of CPUs @var{n} can be omitted. 160@var{maxcpus} specifies 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" 167 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n", 168 QEMU_ARCH_ALL) 169STEXI 170@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 171@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 172@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 173@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 174@findex -numa 175Define a NUMA node and assign RAM and VCPUs to it. 176Set the NUMA distance from a source node to a destination node. 177 178Legacy VCPU assignment uses @samp{cpus} option where 179@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 180@samp{cpus} option represent a contiguous range of CPU indexes 181(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 182set of VCPUs can be represented by providing multiple @samp{cpus} 183options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 184split between them. 185 186For example, the following option assigns VCPUs 0, 1, 2 and 5 to 187a NUMA node: 188@example 189-numa node,cpus=0-2,cpus=5 190@end example 191 192@samp{cpu} option is a new alternative to @samp{cpus} option 193which uses @samp{socket-id|core-id|thread-id} properties to assign 194CPU objects to a @var{node} using topology layout properties of CPU. 195The set of properties is machine specific, and depends on used 196machine type/@samp{smp} options. It could be queried with 197@samp{hotpluggable-cpus} monitor command. 198@samp{node-id} property specifies @var{node} to which CPU object 199will be assigned, it's required for @var{node} to be declared 200with @samp{node} option before it's used with @samp{cpu} option. 201 202For example: 203@example 204-M pc \ 205-smp 1,sockets=2,maxcpus=2 \ 206-numa node,nodeid=0 -numa node,nodeid=1 \ 207-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 208@end example 209 210@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 211assigns RAM from a given memory backend device to a node. If 212@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 213split equally between them. 214 215@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 216if one node uses @samp{memdev}, all of them have to use it. 217 218@var{source} and @var{destination} are NUMA node IDs. 219@var{distance} is the NUMA distance from @var{source} to @var{destination}. 220The distance from a node to itself is always 10. If any pair of nodes is 221given a distance, then all pairs must be given distances. Although, when 222distances are only given in one direction for each pair of nodes, then 223the distances in the opposite directions are assumed to be the same. If, 224however, an asymmetrical pair of distances is given for even one node 225pair, then all node pairs must be provided distance values for both 226directions, even when they are symmetrical. When a node is unreachable 227from another node, set the pair's distance to 255. 228 229Note that the -@option{numa} option doesn't allocate any of the 230specified resources, it just assigns existing resources to NUMA 231nodes. This means that one still has to use the @option{-m}, 232@option{-smp} options to allocate RAM and VCPUs respectively. 233 234ETEXI 235 236DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 237 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 238 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 239STEXI 240@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 241@findex -add-fd 242 243Add a file descriptor to an fd set. Valid options are: 244 245@table @option 246@item fd=@var{fd} 247This option defines the file descriptor of which a duplicate is added to fd set. 248The file descriptor cannot be stdin, stdout, or stderr. 249@item set=@var{set} 250This option defines the ID of the fd set to add the file descriptor to. 251@item opaque=@var{opaque} 252This option defines a free-form string that can be used to describe @var{fd}. 253@end table 254 255You can open an image using pre-opened file descriptors from an fd set: 256@example 257@value{qemu_system} \ 258 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 259 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 260 -drive file=/dev/fdset/2,index=0,media=disk 261@end example 262ETEXI 263 264DEF("set", HAS_ARG, QEMU_OPTION_set, 265 "-set group.id.arg=value\n" 266 " set <arg> parameter for item <id> of type <group>\n" 267 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 268STEXI 269@item -set @var{group}.@var{id}.@var{arg}=@var{value} 270@findex -set 271Set parameter @var{arg} for item @var{id} of type @var{group} 272ETEXI 273 274DEF("global", HAS_ARG, QEMU_OPTION_global, 275 "-global driver.property=value\n" 276 "-global driver=driver,property=property,value=value\n" 277 " set a global default for a driver property\n", 278 QEMU_ARCH_ALL) 279STEXI 280@item -global @var{driver}.@var{prop}=@var{value} 281@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 282@findex -global 283Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 284 285@example 286@value{qemu_system_x86} -global ide-hd.physical_block_size=4096 disk-image.img 287@end example 288 289In particular, you can use this to set driver properties for devices which are 290created automatically by the machine model. To create a device which is not 291created automatically and set properties on it, use -@option{device}. 292 293-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 294driver=@var{driver},property=@var{prop},value=@var{value}. The 295longhand syntax works even when @var{driver} contains a dot. 296ETEXI 297 298DEF("boot", HAS_ARG, QEMU_OPTION_boot, 299 "-boot [order=drives][,once=drives][,menu=on|off]\n" 300 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 301 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 302 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 303 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 304 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 305 QEMU_ARCH_ALL) 306STEXI 307@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] 308@findex -boot 309Specify boot order @var{drives} as a string of drive letters. Valid 310drive letters depend on the target architecture. The x86 PC uses: a, b 311(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 312from network adapter 1-4), hard disk boot is the default. To apply a 313particular boot order only on the first startup, specify it via 314@option{once}. Note that the @option{order} or @option{once} parameter 315should not be used together with the @option{bootindex} property of 316devices, since the firmware implementations normally do not support both 317at the same time. 318 319Interactive boot menus/prompts can be enabled via @option{menu=on} as far 320as firmware/BIOS supports them. The default is non-interactive boot. 321 322A splash picture could be passed to bios, enabling user to show it as logo, 323when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 324supports them. Currently Seabios for X86 system support it. 325limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 326format(true color). The resolution should be supported by the SVGA mode, so 327the recommended is 320x240, 640x480, 800x640. 328 329A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 330when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 331reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 332system support it. 333 334Do strict boot via @option{strict=on} as far as firmware/BIOS 335supports it. This only effects when boot priority is changed by 336bootindex options. The default is non-strict boot. 337 338@example 339# try to boot from network first, then from hard disk 340@value{qemu_system_x86} -boot order=nc 341# boot from CD-ROM first, switch back to default order after reboot 342@value{qemu_system_x86} -boot once=d 343# boot with a splash picture for 5 seconds. 344@value{qemu_system_x86} -boot menu=on,splash=/root/boot.bmp,splash-time=5000 345@end example 346 347Note: The legacy format '-boot @var{drives}' is still supported but its 348use is discouraged as it may be removed from future versions. 349ETEXI 350 351DEF("m", HAS_ARG, QEMU_OPTION_m, 352 "-m [size=]megs[,slots=n,maxmem=size]\n" 353 " configure guest RAM\n" 354 " size: initial amount of guest memory\n" 355 " slots: number of hotplug slots (default: none)\n" 356 " maxmem: maximum amount of guest memory (default: none)\n" 357 "NOTE: Some architectures might enforce a specific granularity\n", 358 QEMU_ARCH_ALL) 359STEXI 360@item -m [size=]@var{megs}[,slots=n,maxmem=size] 361@findex -m 362Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 363Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 364megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 365could be used to set amount of hotpluggable memory slots and maximum amount of 366memory. Note that @var{maxmem} must be aligned to the page size. 367 368For example, the following command-line sets the guest startup RAM size to 3691GB, creates 3 slots to hotplug additional memory and sets the maximum 370memory the guest can reach to 4GB: 371 372@example 373@value{qemu_system} -m 1G,slots=3,maxmem=4G 374@end example 375 376If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 377be enabled and the guest startup RAM will never increase. 378ETEXI 379 380DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 381 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 382STEXI 383@item -mem-path @var{path} 384@findex -mem-path 385Allocate guest RAM from a temporarily created file in @var{path}. 386ETEXI 387 388DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 389 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 390 QEMU_ARCH_ALL) 391STEXI 392@item -mem-prealloc 393@findex -mem-prealloc 394Preallocate memory when using -mem-path. 395ETEXI 396 397DEF("k", HAS_ARG, QEMU_OPTION_k, 398 "-k language use keyboard layout (for example 'fr' for French)\n", 399 QEMU_ARCH_ALL) 400STEXI 401@item -k @var{language} 402@findex -k 403Use keyboard layout @var{language} (for example @code{fr} for 404French). This option is only needed where it is not easy to get raw PC 405keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 406display). You don't normally need to use it on PC/Linux or PC/Windows 407hosts. 408 409The available layouts are: 410@example 411ar de-ch es fo fr-ca hu ja mk no pt-br sv 412da en-gb et fr fr-ch is lt nl pl ru th 413de en-us fi fr-be hr it lv nl-be pt sl tr 414@end example 415 416The default is @code{en-us}. 417ETEXI 418 419 420HXCOMM Deprecated by -audiodev 421DEF("audio-help", 0, QEMU_OPTION_audio_help, 422 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 423 QEMU_ARCH_ALL) 424STEXI 425@item -audio-help 426@findex -audio-help 427Will show the -audiodev equivalent of the currently specified 428(deprecated) environment variables. 429ETEXI 430 431DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 432 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 433 " specifies the audio backend to use\n" 434 " id= identifier of the backend\n" 435 " timer-period= timer period in microseconds\n" 436 " in|out.fixed-settings= use fixed settings for host audio\n" 437 " in|out.frequency= frequency to use with fixed settings\n" 438 " in|out.channels= number of channels to use with fixed settings\n" 439 " in|out.format= sample format to use with fixed settings\n" 440 " valid values: s8, s16, s32, u8, u16, u32\n" 441 " in|out.voices= number of voices to use\n" 442 " in|out.buffer-length= length of buffer in microseconds\n" 443 "-audiodev none,id=id,[,prop[=value][,...]]\n" 444 " dummy driver that discards all output\n" 445#ifdef CONFIG_AUDIO_ALSA 446 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 447 " in|out.dev= name of the audio device to use\n" 448 " in|out.period-length= length of period in microseconds\n" 449 " in|out.try-poll= attempt to use poll mode\n" 450 " threshold= threshold (in microseconds) when playback starts\n" 451#endif 452#ifdef CONFIG_AUDIO_COREAUDIO 453 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 454 " in|out.buffer-count= number of buffers\n" 455#endif 456#ifdef CONFIG_AUDIO_DSOUND 457 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 458 " latency= add extra latency to playback in microseconds\n" 459#endif 460#ifdef CONFIG_AUDIO_OSS 461 "-audiodev oss,id=id[,prop[=value][,...]]\n" 462 " in|out.dev= path of the audio device to use\n" 463 " in|out.buffer-count= number of buffers\n" 464 " in|out.try-poll= attempt to use poll mode\n" 465 " try-mmap= try using memory mapped access\n" 466 " exclusive= open device in exclusive mode\n" 467 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 468#endif 469#ifdef CONFIG_AUDIO_PA 470 "-audiodev pa,id=id[,prop[=value][,...]]\n" 471 " server= PulseAudio server address\n" 472 " in|out.name= source/sink device name\n" 473#endif 474#ifdef CONFIG_AUDIO_SDL 475 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 476#endif 477#ifdef CONFIG_SPICE 478 "-audiodev spice,id=id[,prop[=value][,...]]\n" 479#endif 480 "-audiodev wav,id=id[,prop[=value][,...]]\n" 481 " path= path of wav file to record\n", 482 QEMU_ARCH_ALL) 483STEXI 484@item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]] 485@findex -audiodev 486Adds a new audio backend @var{driver} identified by @var{id}. There are 487global and driver specific properties. Some values can be set 488differently for input and output, they're marked with @code{in|out.}. 489You can set the input's property with @code{in.@var{prop}} and the 490output's property with @code{out.@var{prop}}. For example: 491@example 492-audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 493-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 494@end example 495 496Valid global options are: 497 498@table @option 499@item id=@var{identifier} 500Identifies the audio backend. 501 502@item timer-period=@var{period} 503Sets the timer @var{period} used by the audio subsystem in microseconds. 504Default is 10000 (10 ms). 505 506@item in|out.fixed-settings=on|off 507Use fixed settings for host audio. When off, it will change based on 508how the guest opens the sound card. In this case you must not specify 509@var{frequency}, @var{channels} or @var{format}. Default is on. 510 511@item in|out.frequency=@var{frequency} 512Specify the @var{frequency} to use when using @var{fixed-settings}. 513Default is 44100Hz. 514 515@item in|out.channels=@var{channels} 516Specify the number of @var{channels} to use when using 517@var{fixed-settings}. Default is 2 (stereo). 518 519@item in|out.format=@var{format} 520Specify the sample @var{format} to use when using @var{fixed-settings}. 521Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8}, 522@code{u16}, @code{u32}. Default is @code{s16}. 523 524@item in|out.voices=@var{voices} 525Specify the number of @var{voices} to use. Default is 1. 526 527@item in|out.buffer-length=@var{usecs} 528Sets the size of the buffer in microseconds. 529 530@end table 531 532@item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]] 533Creates a dummy backend that discards all outputs. This backend has no 534backend specific properties. 535 536@item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 537Creates backend using the ALSA. This backend is only available on 538Linux. 539 540ALSA specific options are: 541 542@table @option 543 544@item in|out.dev=@var{device} 545Specify the ALSA @var{device} to use for input and/or output. Default 546is @code{default}. 547 548@item in|out.period-length=@var{usecs} 549Sets the period length in microseconds. 550 551@item in|out.try-poll=on|off 552Attempt to use poll mode with the device. Default is on. 553 554@item threshold=@var{threshold} 555Threshold (in microseconds) when playback starts. Default is 0. 556 557@end table 558 559@item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]] 560Creates a backend using Apple's Core Audio. This backend is only 561available on Mac OS and only supports playback. 562 563Core Audio specific options are: 564 565@table @option 566 567@item in|out.buffer-count=@var{count} 568Sets the @var{count} of the buffers. 569 570@end table 571 572@item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]] 573Creates a backend using Microsoft's DirectSound. This backend is only 574available on Windows and only supports playback. 575 576DirectSound specific options are: 577 578@table @option 579 580@item latency=@var{usecs} 581Add extra @var{usecs} microseconds latency to playback. Default is 58210000 (10 ms). 583 584@end table 585 586@item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]] 587Creates a backend using OSS. This backend is available on most 588Unix-like systems. 589 590OSS specific options are: 591 592@table @option 593 594@item in|out.dev=@var{device} 595Specify the file name of the OSS @var{device} to use. Default is 596@code{/dev/dsp}. 597 598@item in|out.buffer-count=@var{count} 599Sets the @var{count} of the buffers. 600 601@item in|out.try-poll=on|of 602Attempt to use poll mode with the device. Default is on. 603 604@item try-mmap=on|off 605Try using memory mapped device access. Default is off. 606 607@item exclusive=on|off 608Open the device in exclusive mode (vmix won't work in this case). 609Default is off. 610 611@item dsp-policy=@var{policy} 612Sets the timing policy (between 0 and 10, where smaller number means 613smaller latency but higher CPU usage). Use -1 to use buffer sizes 614specified by @code{buffer} and @code{buffer-count}. This option is 615ignored if you do not have OSS 4. Default is 5. 616 617@end table 618 619@item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 620Creates a backend using PulseAudio. This backend is available on most 621systems. 622 623PulseAudio specific options are: 624 625@table @option 626 627@item server=@var{server} 628Sets the PulseAudio @var{server} to connect to. 629 630@item in|out.name=@var{sink} 631Use the specified source/sink for recording/playback. 632 633@end table 634 635@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]] 636Creates a backend using SDL. This backend is available on most systems, 637but you should use your platform's native backend if possible. This 638backend has no backend specific properties. 639 640@item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]] 641Creates a backend that sends audio through SPICE. This backend requires 642@code{-spice} and automatically selected in that case, so usually you 643can ignore this option. This backend has no backend specific 644properties. 645 646@item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]] 647Creates a backend that writes audio to a WAV file. 648 649Backend specific options are: 650 651@table @option 652 653@item path=@var{path} 654Write recorded audio into the specified file. Default is 655@code{qemu.wav}. 656 657@end table 658ETEXI 659 660DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 661 "-soundhw c1,... enable audio support\n" 662 " and only specified sound cards (comma separated list)\n" 663 " use '-soundhw help' to get the list of supported cards\n" 664 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 665STEXI 666@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 667@findex -soundhw 668Enable audio and selected sound hardware. Use 'help' to print all 669available sound hardware. For example: 670 671@example 672@value{qemu_system_x86} -soundhw sb16,adlib disk.img 673@value{qemu_system_x86} -soundhw es1370 disk.img 674@value{qemu_system_x86} -soundhw ac97 disk.img 675@value{qemu_system_x86} -soundhw hda disk.img 676@value{qemu_system_x86} -soundhw all disk.img 677@value{qemu_system_x86} -soundhw help 678@end example 679 680Note that Linux's i810_audio OSS kernel (for AC97) module might 681require manually specifying clocking. 682 683@example 684modprobe i810_audio clocking=48000 685@end example 686ETEXI 687 688DEF("device", HAS_ARG, QEMU_OPTION_device, 689 "-device driver[,prop[=value][,...]]\n" 690 " add device (based on driver)\n" 691 " prop=value,... sets driver properties\n" 692 " use '-device help' to print all possible drivers\n" 693 " use '-device driver,help' to print all possible properties\n", 694 QEMU_ARCH_ALL) 695STEXI 696@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 697@findex -device 698Add device @var{driver}. @var{prop}=@var{value} sets driver 699properties. Valid properties depend on the driver. To get help on 700possible drivers and properties, use @code{-device help} and 701@code{-device @var{driver},help}. 702 703Some drivers are: 704@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}] 705 706Add an IPMI BMC. This is a simulation of a hardware management 707interface processor that normally sits on a system. It provides 708a watchdog and the ability to reset and power control the system. 709You need to connect this to an IPMI interface to make it useful 710 711The IPMI slave address to use for the BMC. The default is 0x20. 712This address is the BMC's address on the I2C network of management 713controllers. If you don't know what this means, it is safe to ignore 714it. 715 716@table @option 717@item id=@var{id} 718The BMC id for interfaces to use this device. 719@item slave_addr=@var{val} 720Define slave address to use for the BMC. The default is 0x20. 721@item sdrfile=@var{file} 722file containing raw Sensor Data Records (SDR) data. The default is none. 723@item fruareasize=@var{val} 724size of a Field Replaceable Unit (FRU) area. The default is 1024. 725@item frudatafile=@var{file} 726file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 727@item guid=@var{uuid} 728value for the GUID for the BMC, in standard UUID format. If this is set, 729get "Get GUID" command to the BMC will return it. Otherwise "Get GUID" 730will return an error. 731@end table 732 733@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 734 735Add a connection to an external IPMI BMC simulator. Instead of 736locally emulating the BMC like the above item, instead connect 737to an external entity that provides the IPMI services. 738 739A connection is made to an external BMC simulator. If you do this, it 740is strongly recommended that you use the "reconnect=" chardev option 741to reconnect to the simulator if the connection is lost. Note that if 742this is not used carefully, it can be a security issue, as the 743interface has the ability to send resets, NMIs, and power off the VM. 744It's best if QEMU makes a connection to an external simulator running 745on a secure port on localhost, so neither the simulator nor QEMU is 746exposed to any outside network. 747 748See the "lanserv/README.vm" file in the OpenIPMI library for more 749details on the external interface. 750 751@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 752 753Add a KCS IPMI interafce on the ISA bus. This also adds a 754corresponding ACPI and SMBIOS entries, if appropriate. 755 756@table @option 757@item bmc=@var{id} 758The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 759@item ioport=@var{val} 760Define the I/O address of the interface. The default is 0xca0 for KCS. 761@item irq=@var{val} 762Define the interrupt to use. The default is 5. To disable interrupts, 763set this to 0. 764@end table 765 766@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 767 768Like the KCS interface, but defines a BT interface. The default port is 7690xe4 and the default interrupt is 5. 770 771ETEXI 772 773DEF("name", HAS_ARG, QEMU_OPTION_name, 774 "-name string1[,process=string2][,debug-threads=on|off]\n" 775 " set the name of the guest\n" 776 " string1 sets the window title and string2 the process name\n" 777 " When debug-threads is enabled, individual threads are given a separate name\n" 778 " NOTE: The thread names are for debugging and not a stable API.\n", 779 QEMU_ARCH_ALL) 780STEXI 781@item -name @var{name} 782@findex -name 783Sets the @var{name} of the guest. 784This name will be displayed in the SDL window caption. 785The @var{name} will also be used for the VNC server. 786Also optionally set the top visible process name in Linux. 787Naming of individual threads can also be enabled on Linux to aid debugging. 788ETEXI 789 790DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 791 "-uuid %08x-%04x-%04x-%04x-%012x\n" 792 " specify machine UUID\n", QEMU_ARCH_ALL) 793STEXI 794@item -uuid @var{uuid} 795@findex -uuid 796Set system UUID. 797ETEXI 798 799STEXI 800@end table 801ETEXI 802DEFHEADING() 803 804DEFHEADING(Block device options:) 805STEXI 806@table @option 807ETEXI 808 809DEF("fda", HAS_ARG, QEMU_OPTION_fda, 810 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 811DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 812STEXI 813@item -fda @var{file} 814@itemx -fdb @var{file} 815@findex -fda 816@findex -fdb 817Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 818ETEXI 819 820DEF("hda", HAS_ARG, QEMU_OPTION_hda, 821 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 822DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 823DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 824 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 825DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 826STEXI 827@item -hda @var{file} 828@itemx -hdb @var{file} 829@itemx -hdc @var{file} 830@itemx -hdd @var{file} 831@findex -hda 832@findex -hdb 833@findex -hdc 834@findex -hdd 835Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 836ETEXI 837 838DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 839 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 840 QEMU_ARCH_ALL) 841STEXI 842@item -cdrom @var{file} 843@findex -cdrom 844Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 845@option{-cdrom} at the same time). You can use the host CD-ROM by 846using @file{/dev/cdrom} as filename (@pxref{host_drives}). 847ETEXI 848 849DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 850 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 851 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 852 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n" 853 " [,driver specific parameters...]\n" 854 " configure a block backend\n", QEMU_ARCH_ALL) 855STEXI 856@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 857@findex -blockdev 858 859Define a new block driver node. Some of the options apply to all block drivers, 860other options are only accepted for a specific block driver. See below for a 861list of generic options and options for the most common block drivers. 862 863Options that expect a reference to another node (e.g. @code{file}) can be 864given in two ways. Either you specify the node name of an already existing node 865(file=@var{node-name}), or you define a new node inline, adding options 866for the referenced node after a dot (file.filename=@var{path},file.aio=native). 867 868A block driver node created with @option{-blockdev} can be used for a guest 869device by specifying its node name for the @code{drive} property in a 870@option{-device} argument that defines a block device. 871 872@table @option 873@item Valid options for any block driver node: 874 875@table @code 876@item driver 877Specifies the block driver to use for the given node. 878@item node-name 879This defines the name of the block driver node by which it will be referenced 880later. The name must be unique, i.e. it must not match the name of a different 881block driver node, or (if you use @option{-drive} as well) the ID of a drive. 882 883If no node name is specified, it is automatically generated. The generated node 884name is not intended to be predictable and changes between QEMU invocations. 885For the top level, an explicit node name must be specified. 886@item read-only 887Open the node read-only. Guest write attempts will fail. 888@item cache.direct 889The host page cache can be avoided with @option{cache.direct=on}. This will 890attempt to do disk IO directly to the guest's memory. QEMU may still perform an 891internal copy of the data. 892@item cache.no-flush 893In case you don't care about data integrity over host failures, you can use 894@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 895any data to the disk but can instead keep things in cache. If anything goes 896wrong, like your host losing power, the disk storage getting disconnected 897accidentally, etc. your image will most probably be rendered unusable. 898@item discard=@var{discard} 899@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 900whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 901ignored or passed to the filesystem. Some machine types may not support 902discard requests. 903@item detect-zeroes=@var{detect-zeroes} 904@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 905conversion of plain zero writes by the OS to driver specific optimized 906zero write commands. You may even choose "unmap" if @var{discard} is set 907to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 908@end table 909 910@item Driver-specific options for @code{file} 911 912This is the protocol-level block driver for accessing regular files. 913 914@table @code 915@item filename 916The path to the image file in the local filesystem 917@item aio 918Specifies the AIO backend (threads/native, default: threads) 919@item locking 920Specifies whether the image file is protected with Linux OFD / POSIX locks. The 921default is to use the Linux Open File Descriptor API if available, otherwise no 922lock is applied. (auto/on/off, default: auto) 923@end table 924Example: 925@example 926-blockdev driver=file,node-name=disk,filename=disk.img 927@end example 928 929@item Driver-specific options for @code{raw} 930 931This is the image format block driver for raw images. It is usually 932stacked on top of a protocol level block driver such as @code{file}. 933 934@table @code 935@item file 936Reference to or definition of the data source block driver node 937(e.g. a @code{file} driver node) 938@end table 939Example 1: 940@example 941-blockdev driver=file,node-name=disk_file,filename=disk.img 942-blockdev driver=raw,node-name=disk,file=disk_file 943@end example 944Example 2: 945@example 946-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 947@end example 948 949@item Driver-specific options for @code{qcow2} 950 951This is the image format block driver for qcow2 images. It is usually 952stacked on top of a protocol level block driver such as @code{file}. 953 954@table @code 955@item file 956Reference to or definition of the data source block driver node 957(e.g. a @code{file} driver node) 958 959@item backing 960Reference to or definition of the backing file block device (default is taken 961from the image file). It is allowed to pass @code{null} here in order to disable 962the default backing file. 963 964@item lazy-refcounts 965Whether to enable the lazy refcounts feature (on/off; default is taken from the 966image file) 967 968@item cache-size 969The maximum total size of the L2 table and refcount block caches in bytes 970(default: the sum of l2-cache-size and refcount-cache-size) 971 972@item l2-cache-size 973The maximum size of the L2 table cache in bytes 974(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 975non-Linux platforms; otherwise, as large as possible within the cache-size, 976while permitting the requested or the minimal refcount cache size) 977 978@item refcount-cache-size 979The maximum size of the refcount block cache in bytes 980(default: 4 times the cluster size; or if cache-size is specified, the part of 981it which is not used for the L2 cache) 982 983@item cache-clean-interval 984Clean unused entries in the L2 and refcount caches. The interval is in seconds. 985The default value is 600 on supporting platforms, and 0 on other platforms. 986Setting it to 0 disables this feature. 987 988@item pass-discard-request 989Whether discard requests to the qcow2 device should be forwarded to the data 990source (on/off; default: on if discard=unmap is specified, off otherwise) 991 992@item pass-discard-snapshot 993Whether discard requests for the data source should be issued when a snapshot 994operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 995default: on) 996 997@item pass-discard-other 998Whether discard requests for the data source should be issued on other 999occasions where a cluster gets freed (on/off; default: off) 1000 1001@item overlap-check 1002Which overlap checks to perform for writes to the image 1003(none/constant/cached/all; default: cached). For details or finer 1004granularity control refer to the QAPI documentation of @code{blockdev-add}. 1005@end table 1006 1007Example 1: 1008@example 1009-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1010-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1011@end example 1012Example 2: 1013@example 1014-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1015@end example 1016 1017@item Driver-specific options for other drivers 1018Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1019 1020@end table 1021 1022ETEXI 1023 1024DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1025 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1026 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1027 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1028 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1029 " [,readonly=on|off][,copy-on-read=on|off]\n" 1030 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1031 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1032 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1033 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1034 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1035 " [[,iops_size=is]]\n" 1036 " [[,group=g]]\n" 1037 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1038STEXI 1039@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1040@findex -drive 1041 1042Define a new drive. This includes creating a block driver node (the backend) as 1043well as a guest device, and is mostly a shortcut for defining the corresponding 1044@option{-blockdev} and @option{-device} options. 1045 1046@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1047addition, it knows the following options: 1048 1049@table @option 1050@item file=@var{file} 1051This option defines which disk image (@pxref{disk_images}) to use with 1052this drive. If the filename contains comma, you must double it 1053(for instance, "file=my,,file" to use file "my,file"). 1054 1055Special files such as iSCSI devices can be specified using protocol 1056specific URLs. See the section for "Device URL Syntax" for more information. 1057@item if=@var{interface} 1058This option defines on which type on interface the drive is connected. 1059Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1060@item bus=@var{bus},unit=@var{unit} 1061These options define where is connected the drive by defining the bus number and 1062the unit id. 1063@item index=@var{index} 1064This option defines where is connected the drive by using an index in the list 1065of available connectors of a given interface type. 1066@item media=@var{media} 1067This option defines the type of the media: disk or cdrom. 1068@item snapshot=@var{snapshot} 1069@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1070(see @option{-snapshot}). 1071@item cache=@var{cache} 1072@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1073and controls how the host cache is used to access block data. This is a 1074shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1075options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1076which provides a default for the @option{write-cache} option of block guest 1077devices (as in @option{-device}). The modes correspond to the following 1078settings: 1079 1080@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1081@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1082@c and the HTML output. 1083@example 1084@ │ cache.writeback cache.direct cache.no-flush 1085─────────────┼───────────────────────────────────────────────── 1086writeback │ on off off 1087none │ on on off 1088writethrough │ off off off 1089directsync │ off on off 1090unsafe │ on off on 1091@end example 1092 1093The default mode is @option{cache=writeback}. 1094 1095@item aio=@var{aio} 1096@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1097@item format=@var{format} 1098Specify which disk @var{format} will be used rather than detecting 1099the format. Can be used to specify format=raw to avoid interpreting 1100an untrusted format header. 1101@item werror=@var{action},rerror=@var{action} 1102Specify which @var{action} to take on write and read errors. Valid actions are: 1103"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1104"report" (report the error to the guest), "enospc" (pause QEMU only if the 1105host disk is full; report the error to the guest otherwise). 1106The default setting is @option{werror=enospc} and @option{rerror=report}. 1107@item copy-on-read=@var{copy-on-read} 1108@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1109file sectors into the image file. 1110@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1111Specify bandwidth throttling limits in bytes per second, either for all request 1112types or for reads or writes only. Small values can lead to timeouts or hangs 1113inside the guest. A safe minimum for disks is 2 MB/s. 1114@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1115Specify bursts in bytes per second, either for all request types or for reads 1116or writes only. Bursts allow the guest I/O to spike above the limit 1117temporarily. 1118@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1119Specify request rate limits in requests per second, either for all request 1120types or for reads or writes only. 1121@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1122Specify bursts in requests per second, either for all request types or for reads 1123or writes only. Bursts allow the guest I/O to spike above the limit 1124temporarily. 1125@item iops_size=@var{is} 1126Let every @var{is} bytes of a request count as a new request for iops 1127throttling purposes. Use this option to prevent guests from circumventing iops 1128limits by sending fewer but larger requests. 1129@item group=@var{g} 1130Join a throttling quota group with given name @var{g}. All drives that are 1131members of the same group are accounted for together. Use this option to 1132prevent guests from circumventing throttling limits by using many small disks 1133instead of a single larger disk. 1134@end table 1135 1136By default, the @option{cache.writeback=on} mode is used. It will report data 1137writes as completed as soon as the data is present in the host page cache. 1138This is safe as long as your guest OS makes sure to correctly flush disk caches 1139where needed. If your guest OS does not handle volatile disk write caches 1140correctly and your host crashes or loses power, then the guest may experience 1141data corruption. 1142 1143For such guests, you should consider using @option{cache.writeback=off}. This 1144means that the host page cache will be used to read and write data, but write 1145notification will be sent to the guest only after QEMU has made sure to flush 1146each write to the disk. Be aware that this has a major impact on performance. 1147 1148When using the @option{-snapshot} option, unsafe caching is always used. 1149 1150Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1151useful when the backing file is over a slow network. By default copy-on-read 1152is off. 1153 1154Instead of @option{-cdrom} you can use: 1155@example 1156@value{qemu_system} -drive file=file,index=2,media=cdrom 1157@end example 1158 1159Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1160use: 1161@example 1162@value{qemu_system} -drive file=file,index=0,media=disk 1163@value{qemu_system} -drive file=file,index=1,media=disk 1164@value{qemu_system} -drive file=file,index=2,media=disk 1165@value{qemu_system} -drive file=file,index=3,media=disk 1166@end example 1167 1168You can open an image using pre-opened file descriptors from an fd set: 1169@example 1170@value{qemu_system} \ 1171 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 1172 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 1173 -drive file=/dev/fdset/2,index=0,media=disk 1174@end example 1175 1176You can connect a CDROM to the slave of ide0: 1177@example 1178@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom 1179@end example 1180 1181If you don't specify the "file=" argument, you define an empty drive: 1182@example 1183@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom 1184@end example 1185 1186Instead of @option{-fda}, @option{-fdb}, you can use: 1187@example 1188@value{qemu_system_x86} -drive file=file,index=0,if=floppy 1189@value{qemu_system_x86} -drive file=file,index=1,if=floppy 1190@end example 1191 1192By default, @var{interface} is "ide" and @var{index} is automatically 1193incremented: 1194@example 1195@value{qemu_system_x86} -drive file=a -drive file=b" 1196@end example 1197is interpreted like: 1198@example 1199@value{qemu_system_x86} -hda a -hdb b 1200@end example 1201ETEXI 1202 1203DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1204 "-mtdblock file use 'file' as on-board Flash memory image\n", 1205 QEMU_ARCH_ALL) 1206STEXI 1207@item -mtdblock @var{file} 1208@findex -mtdblock 1209Use @var{file} as on-board Flash memory image. 1210ETEXI 1211 1212DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1213 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1214STEXI 1215@item -sd @var{file} 1216@findex -sd 1217Use @var{file} as SecureDigital card image. 1218ETEXI 1219 1220DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1221 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1222STEXI 1223@item -pflash @var{file} 1224@findex -pflash 1225Use @var{file} as a parallel flash image. 1226ETEXI 1227 1228DEF("snapshot", 0, QEMU_OPTION_snapshot, 1229 "-snapshot write to temporary files instead of disk image files\n", 1230 QEMU_ARCH_ALL) 1231STEXI 1232@item -snapshot 1233@findex -snapshot 1234Write to temporary files instead of disk image files. In this case, 1235the raw disk image you use is not written back. You can however force 1236the write back by pressing @key{C-a s} (@pxref{disk_images}). 1237ETEXI 1238 1239DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1240 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1241 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1242 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1243 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1244 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1245 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1246 " [[,throttling.iops-size=is]]\n" 1247 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1248 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1249 "-fsdev synth,id=id\n", 1250 QEMU_ARCH_ALL) 1251 1252STEXI 1253 1254@item -fsdev local,id=@var{id},path=@var{path},security_model=@var{security_model} [,writeout=@var{writeout}][,readonly][,fmode=@var{fmode}][,dmode=@var{dmode}] [,throttling.@var{option}=@var{value}[,throttling.@var{option}=@var{value}[,...]]] 1255@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1256@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1257@itemx -fsdev synth,id=@var{id}[,readonly] 1258@findex -fsdev 1259Define a new file system device. Valid options are: 1260@table @option 1261@item local 1262Accesses to the filesystem are done by QEMU. 1263@item proxy 1264Accesses to the filesystem are done by virtfs-proxy-helper(1). 1265@item synth 1266Synthetic filesystem, only used by QTests. 1267@item id=@var{id} 1268Specifies identifier for this device. 1269@item path=@var{path} 1270Specifies the export path for the file system device. Files under 1271this path will be available to the 9p client on the guest. 1272@item security_model=@var{security_model} 1273Specifies the security model to be used for this export path. 1274Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1275In "passthrough" security model, files are stored using the same 1276credentials as they are created on the guest. This requires QEMU 1277to run as root. In "mapped-xattr" security model, some of the file 1278attributes like uid, gid, mode bits and link target are stored as 1279file attributes. For "mapped-file" these attributes are stored in the 1280hidden .virtfs_metadata directory. Directories exported by this security model cannot 1281interact with other unix tools. "none" security model is same as 1282passthrough except the sever won't report failures if it fails to 1283set file attributes like ownership. Security model is mandatory 1284only for local fsdriver. Other fsdrivers (like proxy) don't take 1285security model as a parameter. 1286@item writeout=@var{writeout} 1287This is an optional argument. The only supported value is "immediate". 1288This means that host page cache will be used to read and write data but 1289write notification will be sent to the guest only when the data has been 1290reported as written by the storage subsystem. 1291@item readonly 1292Enables exporting 9p share as a readonly mount for guests. By default 1293read-write access is given. 1294@item socket=@var{socket} 1295Enables proxy filesystem driver to use passed socket file for communicating 1296with virtfs-proxy-helper(1). 1297@item sock_fd=@var{sock_fd} 1298Enables proxy filesystem driver to use passed socket descriptor for 1299communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1300will create socketpair and pass one of the fds as sock_fd. 1301@item fmode=@var{fmode} 1302Specifies the default mode for newly created files on the host. Works only 1303with security models "mapped-xattr" and "mapped-file". 1304@item dmode=@var{dmode} 1305Specifies the default mode for newly created directories on the host. Works 1306only with security models "mapped-xattr" and "mapped-file". 1307@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1308Specify bandwidth throttling limits in bytes per second, either for all request 1309types or for reads or writes only. 1310@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1311Specify bursts in bytes per second, either for all request types or for reads 1312or writes only. Bursts allow the guest I/O to spike above the limit 1313temporarily. 1314@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1315Specify request rate limits in requests per second, either for all request 1316types or for reads or writes only. 1317@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1318Specify bursts in requests per second, either for all request types or for reads 1319or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1320@item throttling.iops-size=@var{is} 1321Let every @var{is} bytes of a request count as a new request for iops 1322throttling purposes. 1323@end table 1324 1325-fsdev option is used along with -device driver "virtio-9p-...". 1326@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1327Options for virtio-9p-... driver are: 1328@table @option 1329@item @var{type} 1330Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1331depending on the machine type. 1332@item fsdev=@var{id} 1333Specifies the id value specified along with -fsdev option. 1334@item mount_tag=@var{mount_tag} 1335Specifies the tag name to be used by the guest to mount this export point. 1336@end table 1337 1338ETEXI 1339 1340DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1341 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1342 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1343 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1344 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1345 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1346 QEMU_ARCH_ALL) 1347 1348STEXI 1349 1350@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}][,multidevs=@var{multidevs}] 1351@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1352@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1353@itemx -virtfs synth,mount_tag=@var{mount_tag} 1354@findex -virtfs 1355 1356Define a new filesystem device and expose it to the guest using a virtio-9p-device. The general form of a Virtual File system pass-through options are: 1357@table @option 1358@item local 1359Accesses to the filesystem are done by QEMU. 1360@item proxy 1361Accesses to the filesystem are done by virtfs-proxy-helper(1). 1362@item synth 1363Synthetic filesystem, only used by QTests. 1364@item id=@var{id} 1365Specifies identifier for the filesystem device 1366@item path=@var{path} 1367Specifies the export path for the file system device. Files under 1368this path will be available to the 9p client on the guest. 1369@item security_model=@var{security_model} 1370Specifies the security model to be used for this export path. 1371Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1372In "passthrough" security model, files are stored using the same 1373credentials as they are created on the guest. This requires QEMU 1374to run as root. In "mapped-xattr" security model, some of the file 1375attributes like uid, gid, mode bits and link target are stored as 1376file attributes. For "mapped-file" these attributes are stored in the 1377hidden .virtfs_metadata directory. Directories exported by this security model cannot 1378interact with other unix tools. "none" security model is same as 1379passthrough except the sever won't report failures if it fails to 1380set file attributes like ownership. Security model is mandatory only 1381for local fsdriver. Other fsdrivers (like proxy) don't take security 1382model as a parameter. 1383@item writeout=@var{writeout} 1384This is an optional argument. The only supported value is "immediate". 1385This means that host page cache will be used to read and write data but 1386write notification will be sent to the guest only when the data has been 1387reported as written by the storage subsystem. 1388@item readonly 1389Enables exporting 9p share as a readonly mount for guests. By default 1390read-write access is given. 1391@item socket=@var{socket} 1392Enables proxy filesystem driver to use passed socket file for 1393communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1394will create socketpair and pass one of the fds as sock_fd. 1395@item sock_fd 1396Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1397descriptor for interfacing with virtfs-proxy-helper(1). 1398@item fmode=@var{fmode} 1399Specifies the default mode for newly created files on the host. Works only 1400with security models "mapped-xattr" and "mapped-file". 1401@item dmode=@var{dmode} 1402Specifies the default mode for newly created directories on the host. Works 1403only with security models "mapped-xattr" and "mapped-file". 1404@item mount_tag=@var{mount_tag} 1405Specifies the tag name to be used by the guest to mount this export point. 1406@item multidevs=@var{multidevs} 1407Specifies how to deal with multiple devices being shared with a 9p export. 1408Supported behaviours are either "remap", "forbid" or "warn". The latter is 1409the default behaviour on which virtfs 9p expects only one device to be 1410shared with the same export, and if more than one device is shared and 1411accessed via the same 9p export then only a warning message is logged 1412(once) by qemu on host side. In order to avoid file ID collisions on guest 1413you should either create a separate virtfs export for each device to be 1414shared with guests (recommended way) or you might use "remap" instead which 1415allows you to share multiple devices with only one export instead, which is 1416achieved by remapping the original inode numbers from host to guest in a 1417way that would prevent such collisions. Remapping inodes in such use cases 1418is required because the original device IDs from host are never passed and 1419exposed on guest. Instead all files of an export shared with virtfs always 1420share the same device id on guest. So two files with identical inode 1421numbers but from actually different devices on host would otherwise cause a 1422file ID collision and hence potential misbehaviours on guest. "forbid" on 1423the other hand assumes like "warn" that only one device is shared by the 1424same export, however it will not only log a warning message but also 1425deny access to additional devices on guest. Note though that "forbid" does 1426currently not block all possible file access operations (e.g. readdir() 1427would still return entries from other devices). 1428@end table 1429ETEXI 1430 1431DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1432 "-virtfs_synth Create synthetic file system image\n", 1433 QEMU_ARCH_ALL) 1434STEXI 1435@item -virtfs_synth 1436@findex -virtfs_synth 1437Create synthetic file system image. Note that this option is now deprecated. 1438Please use @code{-fsdev synth} and @code{-device virtio-9p-...} instead. 1439ETEXI 1440 1441DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1442 "-iscsi [user=user][,password=password]\n" 1443 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1444 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1445 " [,timeout=timeout]\n" 1446 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1447 1448STEXI 1449@item -iscsi 1450@findex -iscsi 1451Configure iSCSI session parameters. 1452ETEXI 1453 1454STEXI 1455@end table 1456ETEXI 1457DEFHEADING() 1458 1459DEFHEADING(USB options:) 1460STEXI 1461@table @option 1462ETEXI 1463 1464DEF("usb", 0, QEMU_OPTION_usb, 1465 "-usb enable on-board USB host controller (if not enabled by default)\n", 1466 QEMU_ARCH_ALL) 1467STEXI 1468@item -usb 1469@findex -usb 1470Enable USB emulation on machine types with an on-board USB host controller (if 1471not enabled by default). Note that on-board USB host controllers may not 1472support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1473on machines with PCI. 1474ETEXI 1475 1476DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1477 "-usbdevice name add the host or guest USB device 'name'\n", 1478 QEMU_ARCH_ALL) 1479STEXI 1480 1481@item -usbdevice @var{devname} 1482@findex -usbdevice 1483Add the USB device @var{devname}. Note that this option is deprecated, 1484please use @code{-device usb-...} instead. @xref{usb_devices}. 1485 1486@table @option 1487 1488@item mouse 1489Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1490 1491@item tablet 1492Pointer device that uses absolute coordinates (like a touchscreen). This 1493means QEMU is able to report the mouse position without having to grab the 1494mouse. Also overrides the PS/2 mouse emulation when activated. 1495 1496@item braille 1497Braille device. This will use BrlAPI to display the braille output on a real 1498or fake device. 1499 1500@end table 1501ETEXI 1502 1503STEXI 1504@end table 1505ETEXI 1506DEFHEADING() 1507 1508DEFHEADING(Display options:) 1509STEXI 1510@table @option 1511ETEXI 1512 1513DEF("display", HAS_ARG, QEMU_OPTION_display, 1514 "-display spice-app[,gl=on|off]\n" 1515 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1516 " [,window_close=on|off][,gl=on|core|es|off]\n" 1517 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1518 "-display vnc=<display>[,<optargs>]\n" 1519 "-display curses[,charset=<encoding>]\n" 1520 "-display none\n" 1521 "-display egl-headless[,rendernode=<file>]" 1522 " select display type\n" 1523 "The default display is equivalent to\n" 1524#if defined(CONFIG_GTK) 1525 "\t\"-display gtk\"\n" 1526#elif defined(CONFIG_SDL) 1527 "\t\"-display sdl\"\n" 1528#elif defined(CONFIG_COCOA) 1529 "\t\"-display cocoa\"\n" 1530#elif defined(CONFIG_VNC) 1531 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1532#else 1533 "\t\"-display none\"\n" 1534#endif 1535 , QEMU_ARCH_ALL) 1536STEXI 1537@item -display @var{type} 1538@findex -display 1539Select type of display to use. This option is a replacement for the 1540old style -sdl/-curses/... options. Valid values for @var{type} are 1541@table @option 1542@item sdl 1543Display video output via SDL (usually in a separate graphics 1544window; see the SDL documentation for other possibilities). 1545@item curses 1546Display video output via curses. For graphics device models which 1547support a text mode, QEMU can display this output using a 1548curses/ncurses interface. Nothing is displayed when the graphics 1549device is in graphical mode or if the graphics device does not support 1550a text mode. Generally only the VGA device models support text mode. 1551The font charset used by the guest can be specified with the 1552@code{charset} option, for example @code{charset=CP850} for IBM CP850 1553encoding. The default is @code{CP437}. 1554@item none 1555Do not display video output. The guest will still see an emulated 1556graphics card, but its output will not be displayed to the QEMU 1557user. This option differs from the -nographic option in that it 1558only affects what is done with video output; -nographic also changes 1559the destination of the serial and parallel port data. 1560@item gtk 1561Display video output in a GTK window. This interface provides drop-down 1562menus and other UI elements to configure and control the VM during 1563runtime. 1564@item vnc 1565Start a VNC server on display <arg> 1566@item egl-headless 1567Offload all OpenGL operations to a local DRI device. For any graphical display, 1568this display needs to be paired with either VNC or SPICE displays. 1569@item spice-app 1570Start QEMU as a Spice server and launch the default Spice client 1571application. The Spice server will redirect the serial consoles and 1572QEMU monitors. (Since 4.0) 1573@end table 1574ETEXI 1575 1576DEF("nographic", 0, QEMU_OPTION_nographic, 1577 "-nographic disable graphical output and redirect serial I/Os to console\n", 1578 QEMU_ARCH_ALL) 1579STEXI 1580@item -nographic 1581@findex -nographic 1582Normally, if QEMU is compiled with graphical window support, it displays 1583output such as guest graphics, guest console, and the QEMU monitor in a 1584window. With this option, you can totally disable graphical output so 1585that QEMU is a simple command line application. The emulated serial port 1586is redirected on the console and muxed with the monitor (unless 1587redirected elsewhere explicitly). Therefore, you can still use QEMU to 1588debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1589switching between the console and monitor. 1590ETEXI 1591 1592DEF("curses", 0, QEMU_OPTION_curses, 1593 "-curses shorthand for -display curses\n", 1594 QEMU_ARCH_ALL) 1595STEXI 1596@item -curses 1597@findex -curses 1598Normally, if QEMU is compiled with graphical window support, it displays 1599output such as guest graphics, guest console, and the QEMU monitor in a 1600window. With this option, QEMU can display the VGA output when in text 1601mode using a curses/ncurses interface. Nothing is displayed in graphical 1602mode. 1603ETEXI 1604 1605DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1606 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1607 QEMU_ARCH_ALL) 1608STEXI 1609@item -alt-grab 1610@findex -alt-grab 1611Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1612affects the special keys (for fullscreen, monitor-mode switching, etc). 1613ETEXI 1614 1615DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1616 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1617 QEMU_ARCH_ALL) 1618STEXI 1619@item -ctrl-grab 1620@findex -ctrl-grab 1621Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1622affects the special keys (for fullscreen, monitor-mode switching, etc). 1623ETEXI 1624 1625DEF("no-quit", 0, QEMU_OPTION_no_quit, 1626 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1627STEXI 1628@item -no-quit 1629@findex -no-quit 1630Disable SDL window close capability. 1631ETEXI 1632 1633DEF("sdl", 0, QEMU_OPTION_sdl, 1634 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1635STEXI 1636@item -sdl 1637@findex -sdl 1638Enable SDL. 1639ETEXI 1640 1641DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1642 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1643 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1644 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1645 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1646 " [,tls-ciphers=<list>]\n" 1647 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1648 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1649 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1650 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1651 " [,jpeg-wan-compression=[auto|never|always]]\n" 1652 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1653 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1654 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1655 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1656 " [,gl=[on|off]][,rendernode=<file>]\n" 1657 " enable spice\n" 1658 " at least one of {port, tls-port} is mandatory\n", 1659 QEMU_ARCH_ALL) 1660STEXI 1661@item -spice @var{option}[,@var{option}[,...]] 1662@findex -spice 1663Enable the spice remote desktop protocol. Valid options are 1664 1665@table @option 1666 1667@item port=<nr> 1668Set the TCP port spice is listening on for plaintext channels. 1669 1670@item addr=<addr> 1671Set the IP address spice is listening on. Default is any address. 1672 1673@item ipv4 1674@itemx ipv6 1675@itemx unix 1676Force using the specified IP version. 1677 1678@item password=<secret> 1679Set the password you need to authenticate. 1680 1681@item sasl 1682Require that the client use SASL to authenticate with the spice. 1683The exact choice of authentication method used is controlled from the 1684system / user's SASL configuration file for the 'qemu' service. This 1685is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1686unprivileged user, an environment variable SASL_CONF_PATH can be used 1687to make it search alternate locations for the service config. 1688While some SASL auth methods can also provide data encryption (eg GSSAPI), 1689it is recommended that SASL always be combined with the 'tls' and 1690'x509' settings to enable use of SSL and server certificates. This 1691ensures a data encryption preventing compromise of authentication 1692credentials. 1693 1694@item disable-ticketing 1695Allow client connects without authentication. 1696 1697@item disable-copy-paste 1698Disable copy paste between the client and the guest. 1699 1700@item disable-agent-file-xfer 1701Disable spice-vdagent based file-xfer between the client and the guest. 1702 1703@item tls-port=<nr> 1704Set the TCP port spice is listening on for encrypted channels. 1705 1706@item x509-dir=<dir> 1707Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1708 1709@item x509-key-file=<file> 1710@itemx x509-key-password=<file> 1711@itemx x509-cert-file=<file> 1712@itemx x509-cacert-file=<file> 1713@itemx x509-dh-key-file=<file> 1714The x509 file names can also be configured individually. 1715 1716@item tls-ciphers=<list> 1717Specify which ciphers to use. 1718 1719@item tls-channel=[main|display|cursor|inputs|record|playback] 1720@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1721Force specific channel to be used with or without TLS encryption. The 1722options can be specified multiple times to configure multiple 1723channels. The special name "default" can be used to set the default 1724mode. For channels which are not explicitly forced into one mode the 1725spice client is allowed to pick tls/plaintext as he pleases. 1726 1727@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1728Configure image compression (lossless). 1729Default is auto_glz. 1730 1731@item jpeg-wan-compression=[auto|never|always] 1732@itemx zlib-glz-wan-compression=[auto|never|always] 1733Configure wan image compression (lossy for slow links). 1734Default is auto. 1735 1736@item streaming-video=[off|all|filter] 1737Configure video stream detection. Default is off. 1738 1739@item agent-mouse=[on|off] 1740Enable/disable passing mouse events via vdagent. Default is on. 1741 1742@item playback-compression=[on|off] 1743Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1744 1745@item seamless-migration=[on|off] 1746Enable/disable spice seamless migration. Default is off. 1747 1748@item gl=[on|off] 1749Enable/disable OpenGL context. Default is off. 1750 1751@item rendernode=<file> 1752DRM render node for OpenGL rendering. If not specified, it will pick 1753the first available. (Since 2.9) 1754 1755@end table 1756ETEXI 1757 1758DEF("portrait", 0, QEMU_OPTION_portrait, 1759 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1760 QEMU_ARCH_ALL) 1761STEXI 1762@item -portrait 1763@findex -portrait 1764Rotate graphical output 90 deg left (only PXA LCD). 1765ETEXI 1766 1767DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1768 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1769 QEMU_ARCH_ALL) 1770STEXI 1771@item -rotate @var{deg} 1772@findex -rotate 1773Rotate graphical output some deg left (only PXA LCD). 1774ETEXI 1775 1776DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1777 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1778 " select video card type\n", QEMU_ARCH_ALL) 1779STEXI 1780@item -vga @var{type} 1781@findex -vga 1782Select type of VGA card to emulate. Valid values for @var{type} are 1783@table @option 1784@item cirrus 1785Cirrus Logic GD5446 Video card. All Windows versions starting from 1786Windows 95 should recognize and use this graphic card. For optimal 1787performances, use 16 bit color depth in the guest and the host OS. 1788(This card was the default before QEMU 2.2) 1789@item std 1790Standard VGA card with Bochs VBE extensions. If your guest OS 1791supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1792to use high resolution modes (>= 1280x1024x16) then you should use 1793this option. (This card is the default since QEMU 2.2) 1794@item vmware 1795VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1796recent XFree86/XOrg server or Windows guest with a driver for this 1797card. 1798@item qxl 1799QXL paravirtual graphic card. It is VGA compatible (including VESA 18002.0 VBE support). Works best with qxl guest drivers installed though. 1801Recommended choice when using the spice protocol. 1802@item tcx 1803(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1804sun4m machines and offers both 8-bit and 24-bit colour depths at a 1805fixed resolution of 1024x768. 1806@item cg3 1807(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1808for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1809resolutions aimed at people wishing to run older Solaris versions. 1810@item virtio 1811Virtio VGA card. 1812@item none 1813Disable VGA card. 1814@end table 1815ETEXI 1816 1817DEF("full-screen", 0, QEMU_OPTION_full_screen, 1818 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1819STEXI 1820@item -full-screen 1821@findex -full-screen 1822Start in full screen. 1823ETEXI 1824 1825DEF("g", 1, QEMU_OPTION_g , 1826 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1827 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1828STEXI 1829@item -g @var{width}x@var{height}[x@var{depth}] 1830@findex -g 1831Set the initial graphical resolution and depth (PPC, SPARC only). 1832ETEXI 1833 1834DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1835 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1836STEXI 1837@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1838@findex -vnc 1839Normally, if QEMU is compiled with graphical window support, it displays 1840output such as guest graphics, guest console, and the QEMU monitor in a 1841window. With this option, you can have QEMU listen on VNC display 1842@var{display} and redirect the VGA display over the VNC session. It is 1843very useful to enable the usb tablet device when using this option 1844(option @option{-device usb-tablet}). When using the VNC display, you 1845must use the @option{-k} parameter to set the keyboard layout if you are 1846not using en-us. Valid syntax for the @var{display} is 1847 1848@table @option 1849 1850@item to=@var{L} 1851 1852With this option, QEMU will try next available VNC @var{display}s, until the 1853number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1854available, e.g. port 5900+@var{display} is already used by another 1855application. By default, to=0. 1856 1857@item @var{host}:@var{d} 1858 1859TCP connections will only be allowed from @var{host} on display @var{d}. 1860By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1861be omitted in which case the server will accept connections from any host. 1862 1863@item unix:@var{path} 1864 1865Connections will be allowed over UNIX domain sockets where @var{path} is the 1866location of a unix socket to listen for connections on. 1867 1868@item none 1869 1870VNC is initialized but not started. The monitor @code{change} command 1871can be used to later start the VNC server. 1872 1873@end table 1874 1875Following the @var{display} value there may be one or more @var{option} flags 1876separated by commas. Valid options are 1877 1878@table @option 1879 1880@item reverse 1881 1882Connect to a listening VNC client via a ``reverse'' connection. The 1883client is specified by the @var{display}. For reverse network 1884connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1885is a TCP port number, not a display number. 1886 1887@item websocket 1888 1889Opens an additional TCP listening port dedicated to VNC Websocket connections. 1890If a bare @var{websocket} option is given, the Websocket port is 18915700+@var{display}. An alternative port can be specified with the 1892syntax @code{websocket}=@var{port}. 1893 1894If @var{host} is specified connections will only be allowed from this host. 1895It is possible to control the websocket listen address independently, using 1896the syntax @code{websocket}=@var{host}:@var{port}. 1897 1898If no TLS credentials are provided, the websocket connection runs in 1899unencrypted mode. If TLS credentials are provided, the websocket connection 1900requires encrypted client connections. 1901 1902@item password 1903 1904Require that password based authentication is used for client connections. 1905 1906The password must be set separately using the @code{set_password} command in 1907the @ref{pcsys_monitor}. The syntax to change your password is: 1908@code{set_password <protocol> <password>} where <protocol> could be either 1909"vnc" or "spice". 1910 1911If you would like to change <protocol> password expiration, you should use 1912@code{expire_password <protocol> <expiration-time>} where expiration time could 1913be one of the following options: now, never, +seconds or UNIX time of 1914expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1915to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1916date and time). 1917 1918You can also use keywords "now" or "never" for the expiration time to 1919allow <protocol> password to expire immediately or never expire. 1920 1921@item tls-creds=@var{ID} 1922 1923Provides the ID of a set of TLS credentials to use to secure the 1924VNC server. They will apply to both the normal VNC server socket 1925and the websocket socket (if enabled). Setting TLS credentials 1926will cause the VNC server socket to enable the VeNCrypt auth 1927mechanism. The credentials should have been previously created 1928using the @option{-object tls-creds} argument. 1929 1930@item tls-authz=@var{ID} 1931 1932Provides the ID of the QAuthZ authorization object against which 1933the client's x509 distinguished name will validated. This object is 1934only resolved at time of use, so can be deleted and recreated on the 1935fly while the VNC server is active. If missing, it will default 1936to denying access. 1937 1938@item sasl 1939 1940Require that the client use SASL to authenticate with the VNC server. 1941The exact choice of authentication method used is controlled from the 1942system / user's SASL configuration file for the 'qemu' service. This 1943is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1944unprivileged user, an environment variable SASL_CONF_PATH can be used 1945to make it search alternate locations for the service config. 1946While some SASL auth methods can also provide data encryption (eg GSSAPI), 1947it is recommended that SASL always be combined with the 'tls' and 1948'x509' settings to enable use of SSL and server certificates. This 1949ensures a data encryption preventing compromise of authentication 1950credentials. See the @ref{vnc_security} section for details on using 1951SASL authentication. 1952 1953@item sasl-authz=@var{ID} 1954 1955Provides the ID of the QAuthZ authorization object against which 1956the client's SASL username will validated. This object is 1957only resolved at time of use, so can be deleted and recreated on the 1958fly while the VNC server is active. If missing, it will default 1959to denying access. 1960 1961@item acl 1962 1963Legacy method for enabling authorization of clients against the 1964x509 distinguished name and SASL username. It results in the creation 1965of two @code{authz-list} objects with IDs of @code{vnc.username} and 1966@code{vnc.x509dname}. The rules for these objects must be configured 1967with the HMP ACL commands. 1968 1969This option is deprecated and should no longer be used. The new 1970@option{sasl-authz} and @option{tls-authz} options are a 1971replacement. 1972 1973@item lossy 1974 1975Enable lossy compression methods (gradient, JPEG, ...). If this 1976option is set, VNC client may receive lossy framebuffer updates 1977depending on its encoding settings. Enabling this option can save 1978a lot of bandwidth at the expense of quality. 1979 1980@item non-adaptive 1981 1982Disable adaptive encodings. Adaptive encodings are enabled by default. 1983An adaptive encoding will try to detect frequently updated screen regions, 1984and send updates in these regions using a lossy encoding (like JPEG). 1985This can be really helpful to save bandwidth when playing videos. Disabling 1986adaptive encodings restores the original static behavior of encodings 1987like Tight. 1988 1989@item share=[allow-exclusive|force-shared|ignore] 1990 1991Set display sharing policy. 'allow-exclusive' allows clients to ask 1992for exclusive access. As suggested by the rfb spec this is 1993implemented by dropping other connections. Connecting multiple 1994clients in parallel requires all clients asking for a shared session 1995(vncviewer: -shared switch). This is the default. 'force-shared' 1996disables exclusive client access. Useful for shared desktop sessions, 1997where you don't want someone forgetting specify -shared disconnect 1998everybody else. 'ignore' completely ignores the shared flag and 1999allows everybody connect unconditionally. Doesn't conform to the rfb 2000spec but is traditional QEMU behavior. 2001 2002@item key-delay-ms 2003 2004Set keyboard delay, for key down and key up events, in milliseconds. 2005Default is 10. Keyboards are low-bandwidth devices, so this slowdown 2006can help the device and guest to keep up and not lose events in case 2007events are arriving in bulk. Possible causes for the latter are flaky 2008network connections, or scripts for automated testing. 2009 2010@item audiodev=@var{audiodev} 2011 2012Use the specified @var{audiodev} when the VNC client requests audio 2013transmission. When not using an -audiodev argument, this option must 2014be omitted, otherwise is must be present and specify a valid audiodev. 2015 2016@end table 2017ETEXI 2018 2019STEXI 2020@end table 2021ETEXI 2022ARCHHEADING(, QEMU_ARCH_I386) 2023 2024ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2025STEXI 2026@table @option 2027ETEXI 2028 2029DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2030 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2031 QEMU_ARCH_I386) 2032STEXI 2033@item -win2k-hack 2034@findex -win2k-hack 2035Use it when installing Windows 2000 to avoid a disk full bug. After 2036Windows 2000 is installed, you no longer need this option (this option 2037slows down the IDE transfers). 2038ETEXI 2039 2040DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2041 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2042 QEMU_ARCH_I386) 2043STEXI 2044@item -no-fd-bootchk 2045@findex -no-fd-bootchk 2046Disable boot signature checking for floppy disks in BIOS. May 2047be needed to boot from old floppy disks. 2048ETEXI 2049 2050DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2051 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2052STEXI 2053@item -no-acpi 2054@findex -no-acpi 2055Disable ACPI (Advanced Configuration and Power Interface) support. Use 2056it if your guest OS complains about ACPI problems (PC target machine 2057only). 2058ETEXI 2059 2060DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2061 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2062STEXI 2063@item -no-hpet 2064@findex -no-hpet 2065Disable HPET support. 2066ETEXI 2067 2068DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2069 "-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" 2070 " ACPI table description\n", QEMU_ARCH_I386) 2071STEXI 2072@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}]...] 2073@findex -acpitable 2074Add ACPI table with specified header fields and context from specified files. 2075For file=, take whole ACPI table from the specified files, including all 2076ACPI headers (possible overridden by other options). 2077For data=, only data 2078portion of the table is used, all header information is specified in the 2079command line. 2080If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2081fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2082to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2083spec. 2084ETEXI 2085 2086DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2087 "-smbios file=binary\n" 2088 " load SMBIOS entry from binary file\n" 2089 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2090 " [,uefi=on|off]\n" 2091 " specify SMBIOS type 0 fields\n" 2092 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2093 " [,uuid=uuid][,sku=str][,family=str]\n" 2094 " specify SMBIOS type 1 fields\n" 2095 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2096 " [,asset=str][,location=str]\n" 2097 " specify SMBIOS type 2 fields\n" 2098 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2099 " [,sku=str]\n" 2100 " specify SMBIOS type 3 fields\n" 2101 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2102 " [,asset=str][,part=str]\n" 2103 " specify SMBIOS type 4 fields\n" 2104 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2105 " [,asset=str][,part=str][,speed=%d]\n" 2106 " specify SMBIOS type 17 fields\n", 2107 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2108STEXI 2109@item -smbios file=@var{binary} 2110@findex -smbios 2111Load SMBIOS entry from binary file. 2112 2113@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2114Specify SMBIOS type 0 fields 2115 2116@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}] 2117Specify SMBIOS type 1 fields 2118 2119@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2120Specify SMBIOS type 2 fields 2121 2122@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2123Specify SMBIOS type 3 fields 2124 2125@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2126Specify SMBIOS type 4 fields 2127 2128@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}] 2129Specify SMBIOS type 17 fields 2130ETEXI 2131 2132STEXI 2133@end table 2134ETEXI 2135DEFHEADING() 2136 2137DEFHEADING(Network options:) 2138STEXI 2139@table @option 2140ETEXI 2141 2142DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2143#ifdef CONFIG_SLIRP 2144 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2145 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2146 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2147 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2148 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2149#ifndef _WIN32 2150 "[,smb=dir[,smbserver=addr]]\n" 2151#endif 2152 " configure a user mode network backend with ID 'str',\n" 2153 " its DHCP server and optional services\n" 2154#endif 2155#ifdef _WIN32 2156 "-netdev tap,id=str,ifname=name\n" 2157 " configure a host TAP network backend with ID 'str'\n" 2158#else 2159 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2160 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2161 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2162 " [,poll-us=n]\n" 2163 " configure a host TAP network backend with ID 'str'\n" 2164 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2165 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2166 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2167 " to deconfigure it\n" 2168 " use '[down]script=no' to disable script execution\n" 2169 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2170 " configure it\n" 2171 " use 'fd=h' to connect to an already opened TAP interface\n" 2172 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2173 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2174 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2175 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2176 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2177 " use vhost=on to enable experimental in kernel accelerator\n" 2178 " (only has effect for virtio guests which use MSIX)\n" 2179 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2180 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2181 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2182 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2183 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2184 " spent on busy polling for vhost net\n" 2185 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2186 " configure a host TAP network backend with ID 'str' that is\n" 2187 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2188 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2189#endif 2190#ifdef __linux__ 2191 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2192 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2193 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2194 " [,rxcookie=rxcookie][,offset=offset]\n" 2195 " configure a network backend with ID 'str' connected to\n" 2196 " an Ethernet over L2TPv3 pseudowire.\n" 2197 " Linux kernel 3.3+ as well as most routers can talk\n" 2198 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2199 " VM to a router and even VM to Host. It is a nearly-universal\n" 2200 " standard (RFC3391). Note - this implementation uses static\n" 2201 " pre-configured tunnels (same as the Linux kernel).\n" 2202 " use 'src=' to specify source address\n" 2203 " use 'dst=' to specify destination address\n" 2204 " use 'udp=on' to specify udp encapsulation\n" 2205 " use 'srcport=' to specify source udp port\n" 2206 " use 'dstport=' to specify destination udp port\n" 2207 " use 'ipv6=on' to force v6\n" 2208 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2209 " well as a weak security measure\n" 2210 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2211 " use 'txcookie=0x012345678' to specify a txcookie\n" 2212 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2213 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2214 " use 'pincounter=on' to work around broken counter handling in peer\n" 2215 " use 'offset=X' to add an extra offset between header and data\n" 2216#endif 2217 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2218 " configure a network backend to connect to another network\n" 2219 " using a socket connection\n" 2220 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2221 " configure a network backend to connect to a multicast maddr and port\n" 2222 " use 'localaddr=addr' to specify the host address to send packets from\n" 2223 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2224 " configure a network backend to connect to another network\n" 2225 " using an UDP tunnel\n" 2226#ifdef CONFIG_VDE 2227 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2228 " configure a network backend to connect to port 'n' of a vde switch\n" 2229 " running on host and listening for incoming connections on 'socketpath'.\n" 2230 " Use group 'groupname' and mode 'octalmode' to change default\n" 2231 " ownership and permissions for communication port.\n" 2232#endif 2233#ifdef CONFIG_NETMAP 2234 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2235 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2236 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2237 " netmap device, defaults to '/dev/netmap')\n" 2238#endif 2239#ifdef CONFIG_POSIX 2240 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2241 " configure a vhost-user network, backed by a chardev 'dev'\n" 2242#endif 2243 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2244 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2245DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2246 "-nic [tap|bridge|" 2247#ifdef CONFIG_SLIRP 2248 "user|" 2249#endif 2250#ifdef __linux__ 2251 "l2tpv3|" 2252#endif 2253#ifdef CONFIG_VDE 2254 "vde|" 2255#endif 2256#ifdef CONFIG_NETMAP 2257 "netmap|" 2258#endif 2259#ifdef CONFIG_POSIX 2260 "vhost-user|" 2261#endif 2262 "socket][,option][,...][mac=macaddr]\n" 2263 " initialize an on-board / default host NIC (using MAC address\n" 2264 " macaddr) and connect it to the given host network backend\n" 2265 "-nic none use it alone to have zero network devices (the default is to\n" 2266 " provided a 'user' network connection)\n", 2267 QEMU_ARCH_ALL) 2268DEF("net", HAS_ARG, QEMU_OPTION_net, 2269 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2270 " configure or create an on-board (or machine default) NIC and\n" 2271 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2272 "-net [" 2273#ifdef CONFIG_SLIRP 2274 "user|" 2275#endif 2276 "tap|" 2277 "bridge|" 2278#ifdef CONFIG_VDE 2279 "vde|" 2280#endif 2281#ifdef CONFIG_NETMAP 2282 "netmap|" 2283#endif 2284 "socket][,option][,option][,...]\n" 2285 " old way to initialize a host network interface\n" 2286 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2287STEXI 2288@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2289@findex -nic 2290This option is a shortcut for configuring both the on-board (default) guest 2291NIC hardware and the host network backend in one go. The host backend options 2292are the same as with the corresponding @option{-netdev} options below. 2293The guest NIC model can be set with @option{model=@var{modelname}}. 2294Use @option{model=help} to list the available device types. 2295The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2296 2297The following two example do exactly the same, to show how @option{-nic} can 2298be used to shorten the command line length (note that the e1000 is the default 2299on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2300@example 2301@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2302@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2303@end example 2304 2305@item -nic none 2306Indicate that no network devices should be configured. It is used to override 2307the default configuration (default NIC with ``user'' host network backend) 2308which is activated if no other networking options are provided. 2309 2310@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2311@findex -netdev 2312Configure user mode host network backend which requires no administrator 2313privilege to run. Valid options are: 2314 2315@table @option 2316@item id=@var{id} 2317Assign symbolic name for use in monitor commands. 2318 2319@item ipv4=on|off and ipv6=on|off 2320Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2321both protocols are enabled. 2322 2323@item net=@var{addr}[/@var{mask}] 2324Set IP network address the guest will see. Optionally specify the netmask, 2325either in the form a.b.c.d or as number of valid top-most bits. Default is 232610.0.2.0/24. 2327 2328@item host=@var{addr} 2329Specify the guest-visible address of the host. Default is the 2nd IP in the 2330guest network, i.e. x.x.x.2. 2331 2332@item ipv6-net=@var{addr}[/@var{int}] 2333Set IPv6 network address the guest will see (default is fec0::/64). The 2334network prefix is given in the usual hexadecimal IPv6 address 2335notation. The prefix size is optional, and is given as the number of 2336valid top-most bits (default is 64). 2337 2338@item ipv6-host=@var{addr} 2339Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2340the guest network, i.e. xxxx::2. 2341 2342@item restrict=on|off 2343If this option is enabled, the guest will be isolated, i.e. it will not be 2344able to contact the host and no guest IP packets will be routed over the host 2345to the outside. This option does not affect any explicitly set forwarding rules. 2346 2347@item hostname=@var{name} 2348Specifies the client hostname reported by the built-in DHCP server. 2349 2350@item dhcpstart=@var{addr} 2351Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2352is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2353 2354@item dns=@var{addr} 2355Specify the guest-visible address of the virtual nameserver. The address must 2356be different from the host address. Default is the 3rd IP in the guest network, 2357i.e. x.x.x.3. 2358 2359@item ipv6-dns=@var{addr} 2360Specify the guest-visible address of the IPv6 virtual nameserver. The address 2361must be different from the host address. Default is the 3rd IP in the guest 2362network, i.e. xxxx::3. 2363 2364@item dnssearch=@var{domain} 2365Provides an entry for the domain-search list sent by the built-in 2366DHCP server. More than one domain suffix can be transmitted by specifying 2367this option multiple times. If supported, this will cause the guest to 2368automatically try to append the given domain suffix(es) in case a domain name 2369can not be resolved. 2370 2371Example: 2372@example 2373@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2374@end example 2375 2376@item domainname=@var{domain} 2377Specifies the client domain name reported by the built-in DHCP server. 2378 2379@item tftp=@var{dir} 2380When using the user mode network stack, activate a built-in TFTP 2381server. The files in @var{dir} will be exposed as the root of a TFTP server. 2382The TFTP client on the guest must be configured in binary mode (use the command 2383@code{bin} of the Unix TFTP client). 2384 2385@item tftp-server-name=@var{name} 2386In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 238766). This can be used to advise the guest to load boot files or configurations 2388from a different server than the host address. 2389 2390@item bootfile=@var{file} 2391When using the user mode network stack, broadcast @var{file} as the BOOTP 2392filename. In conjunction with @option{tftp}, this can be used to network boot 2393a guest from a local directory. 2394 2395Example (using pxelinux): 2396@example 2397@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2398 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2399@end example 2400 2401@item smb=@var{dir}[,smbserver=@var{addr}] 2402When using the user mode network stack, activate a built-in SMB 2403server so that Windows OSes can access to the host files in @file{@var{dir}} 2404transparently. The IP address of the SMB server can be set to @var{addr}. By 2405default the 4th IP in the guest network is used, i.e. x.x.x.4. 2406 2407In the guest Windows OS, the line: 2408@example 240910.0.2.4 smbserver 2410@end example 2411must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2412or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2413 2414Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2415 2416Note that a SAMBA server must be installed on the host OS. 2417 2418@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2419Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2420the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2421@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2422given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2423be bound to a specific host interface. If no connection type is set, TCP is 2424used. This option can be given multiple times. 2425 2426For example, to redirect host X11 connection from screen 1 to guest 2427screen 0, use the following: 2428 2429@example 2430# on the host 2431@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2432# this host xterm should open in the guest X11 server 2433xterm -display :1 2434@end example 2435 2436To redirect telnet connections from host port 5555 to telnet port on 2437the guest, use the following: 2438 2439@example 2440# on the host 2441@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2442telnet localhost 5555 2443@end example 2444 2445Then when you use on the host @code{telnet localhost 5555}, you 2446connect to the guest telnet server. 2447 2448@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2449@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2450Forward guest TCP connections to the IP address @var{server} on port @var{port} 2451to the character device @var{dev} or to a program executed by @var{cmd:command} 2452which gets spawned for each connection. This option can be given multiple times. 2453 2454You can either use a chardev directly and have that one used throughout QEMU's 2455lifetime, like in the following example: 2456 2457@example 2458# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2459# the guest accesses it 2460@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2461@end example 2462 2463Or you can execute a command on every TCP connection established by the guest, 2464so that QEMU behaves similar to an inetd process for that virtual server: 2465 2466@example 2467# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2468# and connect the TCP stream to its stdin/stdout 2469@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2470@end example 2471 2472@end table 2473 2474@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2475Configure a host TAP network backend with ID @var{id}. 2476 2477Use the network script @var{file} to configure it and the network script 2478@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2479automatically provides one. The default network configure script is 2480@file{/etc/qemu-ifup} and the default network deconfigure script is 2481@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2482to disable script execution. 2483 2484If running QEMU as an unprivileged user, use the network helper 2485@var{helper} to configure the TAP interface and attach it to the bridge. 2486The default network helper executable is @file{/path/to/qemu-bridge-helper} 2487and the default bridge device is @file{br0}. 2488 2489@option{fd}=@var{h} can be used to specify the handle of an already 2490opened host TAP interface. 2491 2492Examples: 2493 2494@example 2495#launch a QEMU instance with the default network script 2496@value{qemu_system} linux.img -nic tap 2497@end example 2498 2499@example 2500#launch a QEMU instance with two NICs, each one connected 2501#to a TAP device 2502@value{qemu_system} linux.img \ 2503 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2504 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2505@end example 2506 2507@example 2508#launch a QEMU instance with the default network helper to 2509#connect a TAP device to bridge br0 2510@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2511 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2512@end example 2513 2514@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2515Connect a host TAP network interface to a host bridge device. 2516 2517Use the network helper @var{helper} to configure the TAP interface and 2518attach it to the bridge. The default network helper executable is 2519@file{/path/to/qemu-bridge-helper} and the default bridge 2520device is @file{br0}. 2521 2522Examples: 2523 2524@example 2525#launch a QEMU instance with the default network helper to 2526#connect a TAP device to bridge br0 2527@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2528@end example 2529 2530@example 2531#launch a QEMU instance with the default network helper to 2532#connect a TAP device to bridge qemubr0 2533@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2534@end example 2535 2536@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2537 2538This host network backend can be used to connect the guest's network to 2539another QEMU virtual machine using a TCP socket connection. If @option{listen} 2540is specified, QEMU waits for incoming connections on @var{port} 2541(@var{host} is optional). @option{connect} is used to connect to 2542another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2543specifies an already opened TCP socket. 2544 2545Example: 2546@example 2547# launch a first QEMU instance 2548@value{qemu_system} linux.img \ 2549 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2550 -netdev socket,id=n1,listen=:1234 2551# connect the network of this instance to the network of the first instance 2552@value{qemu_system} linux.img \ 2553 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2554 -netdev socket,id=n2,connect=127.0.0.1:1234 2555@end example 2556 2557@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2558 2559Configure a socket host network backend to share the guest's network traffic 2560with another QEMU virtual machines using a UDP multicast socket, effectively 2561making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2562NOTES: 2563@enumerate 2564@item 2565Several QEMU can be running on different hosts and share same bus (assuming 2566correct multicast setup for these hosts). 2567@item 2568mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2569@url{http://user-mode-linux.sf.net}. 2570@item 2571Use @option{fd=h} to specify an already opened UDP multicast socket. 2572@end enumerate 2573 2574Example: 2575@example 2576# launch one QEMU instance 2577@value{qemu_system} linux.img \ 2578 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2579 -netdev socket,id=n1,mcast=230.0.0.1:1234 2580# launch another QEMU instance on same "bus" 2581@value{qemu_system} linux.img \ 2582 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2583 -netdev socket,id=n2,mcast=230.0.0.1:1234 2584# launch yet another QEMU instance on same "bus" 2585@value{qemu_system} linux.img \ 2586 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2587 -netdev socket,id=n3,mcast=230.0.0.1:1234 2588@end example 2589 2590Example (User Mode Linux compat.): 2591@example 2592# launch QEMU instance (note mcast address selected is UML's default) 2593@value{qemu_system} linux.img \ 2594 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2595 -netdev socket,id=n1,mcast=239.192.168.1:1102 2596# launch UML 2597/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2598@end example 2599 2600Example (send packets from host's 1.2.3.4): 2601@example 2602@value{qemu_system} linux.img \ 2603 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2604 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2605@end example 2606 2607@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}] 2608Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2609popular protocol to transport Ethernet (and other Layer 2) data frames between 2610two systems. It is present in routers, firewalls and the Linux kernel 2611(from version 3.3 onwards). 2612 2613This transport allows a VM to communicate to another VM, router or firewall directly. 2614 2615@table @option 2616@item src=@var{srcaddr} 2617 source address (mandatory) 2618@item dst=@var{dstaddr} 2619 destination address (mandatory) 2620@item udp 2621 select udp encapsulation (default is ip). 2622@item srcport=@var{srcport} 2623 source udp port. 2624@item dstport=@var{dstport} 2625 destination udp port. 2626@item ipv6 2627 force v6, otherwise defaults to v4. 2628@item rxcookie=@var{rxcookie} 2629@itemx txcookie=@var{txcookie} 2630 Cookies are a weak form of security in the l2tpv3 specification. 2631Their function is mostly to prevent misconfiguration. By default they are 32 2632bit. 2633@item cookie64 2634 Set cookie size to 64 bit instead of the default 32 2635@item counter=off 2636 Force a 'cut-down' L2TPv3 with no counter as in 2637draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2638@item pincounter=on 2639 Work around broken counter handling in peer. This may also help on 2640networks which have packet reorder. 2641@item offset=@var{offset} 2642 Add an extra offset between header and data 2643@end table 2644 2645For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2646on the remote Linux host 1.2.3.4: 2647@example 2648# Setup tunnel on linux host using raw ip as encapsulation 2649# on 1.2.3.4 2650ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2651 encap udp udp_sport 16384 udp_dport 16384 2652ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2653 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2654ifconfig vmtunnel0 mtu 1500 2655ifconfig vmtunnel0 up 2656brctl addif br-lan vmtunnel0 2657 2658 2659# on 4.3.2.1 2660# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2661 2662@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2663 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2664 2665@end example 2666 2667@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2668Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2669listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2670and MODE @var{octalmode} to change default ownership and permissions for 2671communication port. This option is only available if QEMU has been compiled 2672with vde support enabled. 2673 2674Example: 2675@example 2676# launch vde switch 2677vde_switch -F -sock /tmp/myswitch 2678# launch QEMU instance 2679@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2680@end example 2681 2682@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2683 2684Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2685be a unix domain socket backed one. The vhost-user uses a specifically defined 2686protocol to pass vhost ioctl replacement messages to an application on the other 2687end of the socket. On non-MSIX guests, the feature can be forced with 2688@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2689be created for multiqueue vhost-user. 2690 2691Example: 2692@example 2693qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2694 -numa node,memdev=mem \ 2695 -chardev socket,id=chr0,path=/path/to/socket \ 2696 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2697 -device virtio-net-pci,netdev=net0 2698@end example 2699 2700@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2701 2702Create a hub port on the emulated hub with ID @var{hubid}. 2703 2704The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2705single netdev. Alternatively, you can also connect the hubport to another 2706netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2707 2708@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2709@findex -net 2710Legacy option to configure or create an on-board (or machine default) Network 2711Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2712the default hub), or to the netdev @var{nd}. 2713The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2714can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2715only), and a @var{name} can be assigned for use in monitor commands. 2716Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2717that the card should have; this option currently only affects virtio cards; set 2718@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2719NIC is created. QEMU can emulate several different models of network card. 2720Use @code{-net nic,model=help} for a list of available devices for your target. 2721 2722@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2723Configure a host network backend (with the options corresponding to the same 2724@option{-netdev} option) and connect it to the emulated hub 0 (the default 2725hub). Use @var{name} to specify the name of the hub port. 2726ETEXI 2727 2728STEXI 2729@end table 2730ETEXI 2731DEFHEADING() 2732 2733DEFHEADING(Character device options:) 2734 2735DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2736 "-chardev help\n" 2737 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2738 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2739 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2740 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2741 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2742 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2743 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2744 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2745 " [,logfile=PATH][,logappend=on|off]\n" 2746 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2747 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2748 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2749 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2750 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2751 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2752#ifdef _WIN32 2753 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2754 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2755#else 2756 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2757 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2758#endif 2759#ifdef CONFIG_BRLAPI 2760 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2761#endif 2762#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2763 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2764 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2765 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2766#endif 2767#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2768 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2769 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2770#endif 2771#if defined(CONFIG_SPICE) 2772 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2773 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2774#endif 2775 , QEMU_ARCH_ALL 2776) 2777 2778STEXI 2779 2780The general form of a character device option is: 2781@table @option 2782@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2783@findex -chardev 2784Backend is one of: 2785@option{null}, 2786@option{socket}, 2787@option{udp}, 2788@option{msmouse}, 2789@option{vc}, 2790@option{ringbuf}, 2791@option{file}, 2792@option{pipe}, 2793@option{console}, 2794@option{serial}, 2795@option{pty}, 2796@option{stdio}, 2797@option{braille}, 2798@option{tty}, 2799@option{parallel}, 2800@option{parport}, 2801@option{spicevmc}, 2802@option{spiceport}. 2803The specific backend will determine the applicable options. 2804 2805Use @code{-chardev help} to print all available chardev backend types. 2806 2807All devices must have an id, which can be any string up to 127 characters long. 2808It is used to uniquely identify this device in other command line directives. 2809 2810A character device may be used in multiplexing mode by multiple front-ends. 2811Specify @option{mux=on} to enable this mode. 2812A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2813backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2814If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2815create a multiplexer with your specified ID, and you can then configure multiple 2816front ends to use that chardev ID for their input/output. Up to four different 2817front ends can be connected to a single multiplexed chardev. (Without 2818multiplexing enabled, a chardev can only be used by a single front end.) 2819For instance you could use this to allow a single stdio chardev to be used by 2820two serial ports and the QEMU monitor: 2821 2822@example 2823-chardev stdio,mux=on,id=char0 \ 2824-mon chardev=char0,mode=readline \ 2825-serial chardev:char0 \ 2826-serial chardev:char0 2827@end example 2828 2829You can have more than one multiplexer in a system configuration; for instance 2830you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2831multiplexed between the QEMU monitor and a parallel port: 2832 2833@example 2834-chardev stdio,mux=on,id=char0 \ 2835-mon chardev=char0,mode=readline \ 2836-parallel chardev:char0 \ 2837-chardev tcp,...,mux=on,id=char1 \ 2838-serial chardev:char1 \ 2839-serial chardev:char1 2840@end example 2841 2842When you're using a multiplexed character device, some escape sequences are 2843interpreted in the input. @xref{mux_keys, Keys in the character backend 2844multiplexer}. 2845 2846Note that some other command line options may implicitly create multiplexed 2847character backends; for instance @option{-serial mon:stdio} creates a 2848multiplexed stdio backend connected to the serial port and the QEMU monitor, 2849and @option{-nographic} also multiplexes the console and the monitor to 2850stdio. 2851 2852There is currently no support for multiplexing in the other direction 2853(where a single QEMU front end takes input and output from multiple chardevs). 2854 2855Every backend supports the @option{logfile} option, which supplies the path 2856to a file to record all data transmitted via the backend. The @option{logappend} 2857option controls whether the log file will be truncated or appended to when 2858opened. 2859 2860@end table 2861 2862The available backends are: 2863 2864@table @option 2865@item -chardev null,id=@var{id} 2866A void device. This device will not emit any data, and will drop any data it 2867receives. The null backend does not take any options. 2868 2869@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,websocket][,reconnect=@var{seconds}][,tls-creds=@var{id}][,tls-authz=@var{id}] 2870 2871Create a two-way stream socket, which can be either a TCP or a unix socket. A 2872unix socket will be created if @option{path} is specified. Behaviour is 2873undefined if TCP options are specified for a unix socket. 2874 2875@option{server} specifies that the socket shall be a listening socket. 2876 2877@option{nowait} specifies that QEMU should not block waiting for a client to 2878connect to a listening socket. 2879 2880@option{telnet} specifies that traffic on the socket should interpret telnet 2881escape sequences. 2882 2883@option{websocket} specifies that the socket uses WebSocket protocol for 2884communication. 2885 2886@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2887the remote end goes away. qemu will delay this many seconds and then attempt 2888to reconnect. Zero disables reconnecting, and is the default. 2889 2890@option{tls-creds} requests enablement of the TLS protocol for encryption, 2891and specifies the id of the TLS credentials to use for the handshake. The 2892credentials must be previously created with the @option{-object tls-creds} 2893argument. 2894 2895@option{tls-auth} provides the ID of the QAuthZ authorization object against 2896which the client's x509 distinguished name will be validated. This object is 2897only resolved at time of use, so can be deleted and recreated on the fly 2898while the chardev server is active. If missing, it will default to denying 2899access. 2900 2901TCP and unix socket options are given below: 2902 2903@table @option 2904 2905@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2906 2907@option{host} for a listening socket specifies the local address to be bound. 2908For a connecting socket species the remote host to connect to. @option{host} is 2909optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2910 2911@option{port} for a listening socket specifies the local port to be bound. For a 2912connecting socket specifies the port on the remote host to connect to. 2913@option{port} can be given as either a port number or a service name. 2914@option{port} is required. 2915 2916@option{to} is only relevant to listening sockets. If it is specified, and 2917@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2918to and including @option{to} until it succeeds. @option{to} must be specified 2919as a port number. 2920 2921@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2922If neither is specified the socket may use either protocol. 2923 2924@option{nodelay} disables the Nagle algorithm. 2925 2926@item unix options: path=@var{path} 2927 2928@option{path} specifies the local path of the unix socket. @option{path} is 2929required. 2930 2931@end table 2932 2933@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2934 2935Sends all traffic from the guest to a remote host over UDP. 2936 2937@option{host} specifies the remote host to connect to. If not specified it 2938defaults to @code{localhost}. 2939 2940@option{port} specifies the port on the remote host to connect to. @option{port} 2941is required. 2942 2943@option{localaddr} specifies the local address to bind to. If not specified it 2944defaults to @code{0.0.0.0}. 2945 2946@option{localport} specifies the local port to bind to. If not specified any 2947available local port will be used. 2948 2949@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2950If neither is specified the device may use either protocol. 2951 2952@item -chardev msmouse,id=@var{id} 2953 2954Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2955take any options. 2956 2957@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 2958 2959Connect to a QEMU text console. @option{vc} may optionally be given a specific 2960size. 2961 2962@option{width} and @option{height} specify the width and height respectively of 2963the console, in pixels. 2964 2965@option{cols} and @option{rows} specify that the console be sized to fit a text 2966console with the given dimensions. 2967 2968@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 2969 2970Create a ring buffer with fixed size @option{size}. 2971@var{size} must be a power of two and defaults to @code{64K}. 2972 2973@item -chardev file,id=@var{id},path=@var{path} 2974 2975Log all traffic received from the guest to a file. 2976 2977@option{path} specifies the path of the file to be opened. This file will be 2978created if it does not already exist, and overwritten if it does. @option{path} 2979is required. 2980 2981@item -chardev pipe,id=@var{id},path=@var{path} 2982 2983Create a two-way connection to the guest. The behaviour differs slightly between 2984Windows hosts and other hosts: 2985 2986On Windows, a single duplex pipe will be created at 2987@file{\\.pipe\@option{path}}. 2988 2989On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2990@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2991received by the guest. Data written by the guest can be read from 2992@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2993be present. 2994 2995@option{path} forms part of the pipe path as described above. @option{path} is 2996required. 2997 2998@item -chardev console,id=@var{id} 2999 3000Send traffic from the guest to QEMU's standard output. @option{console} does not 3001take any options. 3002 3003@option{console} is only available on Windows hosts. 3004 3005@item -chardev serial,id=@var{id},path=@option{path} 3006 3007Send traffic from the guest to a serial device on the host. 3008 3009On Unix hosts serial will actually accept any tty device, 3010not only serial lines. 3011 3012@option{path} specifies the name of the serial device to open. 3013 3014@item -chardev pty,id=@var{id} 3015 3016Create a new pseudo-terminal on the host and connect to it. @option{pty} does 3017not take any options. 3018 3019@option{pty} is not available on Windows hosts. 3020 3021@item -chardev stdio,id=@var{id}[,signal=on|off] 3022Connect to standard input and standard output of the QEMU process. 3023 3024@option{signal} controls if signals are enabled on the terminal, that includes 3025exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3026default, use @option{signal=off} to disable it. 3027 3028@item -chardev braille,id=@var{id} 3029 3030Connect to a local BrlAPI server. @option{braille} does not take any options. 3031 3032@item -chardev tty,id=@var{id},path=@var{path} 3033 3034@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3035DragonFlyBSD hosts. It is an alias for @option{serial}. 3036 3037@option{path} specifies the path to the tty. @option{path} is required. 3038 3039@item -chardev parallel,id=@var{id},path=@var{path} 3040@itemx -chardev parport,id=@var{id},path=@var{path} 3041 3042@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3043 3044Connect to a local parallel port. 3045 3046@option{path} specifies the path to the parallel port device. @option{path} is 3047required. 3048 3049@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3050 3051@option{spicevmc} is only available when spice support is built in. 3052 3053@option{debug} debug level for spicevmc 3054 3055@option{name} name of spice channel to connect to 3056 3057Connect to a spice virtual machine channel, such as vdiport. 3058 3059@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3060 3061@option{spiceport} is only available when spice support is built in. 3062 3063@option{debug} debug level for spicevmc 3064 3065@option{name} name of spice port to connect to 3066 3067Connect to a spice port, allowing a Spice client to handle the traffic 3068identified by a name (preferably a fqdn). 3069ETEXI 3070 3071STEXI 3072@end table 3073ETEXI 3074DEFHEADING() 3075 3076DEFHEADING(Bluetooth(R) options:) 3077STEXI 3078@table @option 3079ETEXI 3080 3081DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3082 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3083 "-bt hci,host[:id]\n" \ 3084 " use host's HCI with the given name\n" \ 3085 "-bt hci[,vlan=n]\n" \ 3086 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3087 "-bt vhci[,vlan=n]\n" \ 3088 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3089 "-bt device:dev[,vlan=n]\n" \ 3090 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3091 QEMU_ARCH_ALL) 3092STEXI 3093@item -bt hci[...] 3094@findex -bt 3095Defines the function of the corresponding Bluetooth HCI. -bt options 3096are matched with the HCIs present in the chosen machine type. For 3097example when emulating a machine with only one HCI built into it, only 3098the first @code{-bt hci[...]} option is valid and defines the HCI's 3099logic. The Transport Layer is decided by the machine type. Currently 3100the machines @code{n800} and @code{n810} have one HCI and all other 3101machines have none. 3102 3103Note: This option and the whole bluetooth subsystem is considered as deprecated. 3104If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where 3105you describe your usecase. 3106 3107@anchor{bt-hcis} 3108The following three types are recognized: 3109 3110@table @option 3111@item -bt hci,null 3112(default) The corresponding Bluetooth HCI assumes no internal logic 3113and will not respond to any HCI commands or emit events. 3114 3115@item -bt hci,host[:@var{id}] 3116(@code{bluez} only) The corresponding HCI passes commands / events 3117to / from the physical HCI identified by the name @var{id} (default: 3118@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3119capable systems like Linux. 3120 3121@item -bt hci[,vlan=@var{n}] 3122Add a virtual, standard HCI that will participate in the Bluetooth 3123scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3124VLANs, devices inside a bluetooth network @var{n} can only communicate 3125with other devices in the same network (scatternet). 3126@end table 3127 3128@item -bt vhci[,vlan=@var{n}] 3129(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3130to the host bluetooth stack instead of to the emulated target. This 3131allows the host and target machines to participate in a common scatternet 3132and communicate. Requires the Linux @code{vhci} driver installed. Can 3133be used as following: 3134 3135@example 3136@value{qemu_system} [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3137@end example 3138 3139@item -bt device:@var{dev}[,vlan=@var{n}] 3140Emulate a bluetooth device @var{dev} and place it in network @var{n} 3141(default @code{0}). QEMU can only emulate one type of bluetooth devices 3142currently: 3143 3144@table @option 3145@item keyboard 3146Virtual wireless keyboard implementing the HIDP bluetooth profile. 3147@end table 3148ETEXI 3149 3150STEXI 3151@end table 3152ETEXI 3153DEFHEADING() 3154 3155#ifdef CONFIG_TPM 3156DEFHEADING(TPM device options:) 3157 3158DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3159 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3160 " use path to provide path to a character device; default is /dev/tpm0\n" 3161 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3162 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3163 "-tpmdev emulator,id=id,chardev=dev\n" 3164 " configure the TPM device using chardev backend\n", 3165 QEMU_ARCH_ALL) 3166STEXI 3167 3168The general form of a TPM device option is: 3169@table @option 3170 3171@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3172@findex -tpmdev 3173 3174The specific backend type will determine the applicable options. 3175The @code{-tpmdev} option creates the TPM backend and requires a 3176@code{-device} option that specifies the TPM frontend interface model. 3177 3178Use @code{-tpmdev help} to print all available TPM backend types. 3179 3180@end table 3181 3182The available backends are: 3183 3184@table @option 3185 3186@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3187 3188(Linux-host only) Enable access to the host's TPM using the passthrough 3189driver. 3190 3191@option{path} specifies the path to the host's TPM device, i.e., on 3192a Linux host this would be @code{/dev/tpm0}. 3193@option{path} is optional and by default @code{/dev/tpm0} is used. 3194 3195@option{cancel-path} specifies the path to the host TPM device's sysfs 3196entry allowing for cancellation of an ongoing TPM command. 3197@option{cancel-path} is optional and by default QEMU will search for the 3198sysfs entry to use. 3199 3200Some notes about using the host's TPM with the passthrough driver: 3201 3202The TPM device accessed by the passthrough driver must not be 3203used by any other application on the host. 3204 3205Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3206the VM's firmware (BIOS/UEFI) will not be able to initialize the 3207TPM again and may therefore not show a TPM-specific menu that would 3208otherwise allow the user to configure the TPM, e.g., allow the user to 3209enable/disable or activate/deactivate the TPM. 3210Further, if TPM ownership is released from within a VM then the host's TPM 3211will get disabled and deactivated. To enable and activate the 3212TPM again afterwards, the host has to be rebooted and the user is 3213required to enter the firmware's menu to enable and activate the TPM. 3214If the TPM is left disabled and/or deactivated most TPM commands will fail. 3215 3216To create a passthrough TPM use the following two options: 3217@example 3218-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3219@end example 3220Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3221@code{tpmdev=tpm0} in the device option. 3222 3223@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3224 3225(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3226chardev backend. 3227 3228@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3229 3230To create a TPM emulator backend device with chardev socket backend: 3231@example 3232 3233-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3234 3235@end example 3236 3237ETEXI 3238 3239STEXI 3240@end table 3241ETEXI 3242DEFHEADING() 3243 3244#endif 3245 3246DEFHEADING(Linux/Multiboot boot specific:) 3247STEXI 3248 3249When using these options, you can use a given Linux or Multiboot 3250kernel without installing it in the disk image. It can be useful 3251for easier testing of various kernels. 3252 3253@table @option 3254ETEXI 3255 3256DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3257 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3258STEXI 3259@item -kernel @var{bzImage} 3260@findex -kernel 3261Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3262or in multiboot format. 3263ETEXI 3264 3265DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3266 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3267STEXI 3268@item -append @var{cmdline} 3269@findex -append 3270Use @var{cmdline} as kernel command line 3271ETEXI 3272 3273DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3274 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3275STEXI 3276@item -initrd @var{file} 3277@findex -initrd 3278Use @var{file} as initial ram disk. 3279 3280@item -initrd "@var{file1} arg=foo,@var{file2}" 3281 3282This syntax is only available with multiboot. 3283 3284Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3285first module. 3286ETEXI 3287 3288DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3289 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3290STEXI 3291@item -dtb @var{file} 3292@findex -dtb 3293Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3294on boot. 3295ETEXI 3296 3297STEXI 3298@end table 3299ETEXI 3300DEFHEADING() 3301 3302DEFHEADING(Debug/Expert options:) 3303STEXI 3304@table @option 3305ETEXI 3306 3307DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3308 "-fw_cfg [name=]<name>,file=<file>\n" 3309 " add named fw_cfg entry with contents from file\n" 3310 "-fw_cfg [name=]<name>,string=<str>\n" 3311 " add named fw_cfg entry with contents from string\n", 3312 QEMU_ARCH_ALL) 3313STEXI 3314 3315@item -fw_cfg [name=]@var{name},file=@var{file} 3316@findex -fw_cfg 3317Add named fw_cfg entry with contents from file @var{file}. 3318 3319@item -fw_cfg [name=]@var{name},string=@var{str} 3320Add named fw_cfg entry with contents from string @var{str}. 3321 3322The terminating NUL character of the contents of @var{str} will not be 3323included as part of the fw_cfg item data. To insert contents with 3324embedded NUL characters, you have to use the @var{file} parameter. 3325 3326The fw_cfg entries are passed by QEMU through to the guest. 3327 3328Example: 3329@example 3330 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3331@end example 3332creates an fw_cfg entry named opt/com.mycompany/blob with contents 3333from ./my_blob.bin. 3334 3335ETEXI 3336 3337DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3338 "-serial dev redirect the serial port to char device 'dev'\n", 3339 QEMU_ARCH_ALL) 3340STEXI 3341@item -serial @var{dev} 3342@findex -serial 3343Redirect the virtual serial port to host character device 3344@var{dev}. The default device is @code{vc} in graphical mode and 3345@code{stdio} in non graphical mode. 3346 3347This option can be used several times to simulate up to 4 serial 3348ports. 3349 3350Use @code{-serial none} to disable all serial ports. 3351 3352Available character devices are: 3353@table @option 3354@item vc[:@var{W}x@var{H}] 3355Virtual console. Optionally, a width and height can be given in pixel with 3356@example 3357vc:800x600 3358@end example 3359It is also possible to specify width or height in characters: 3360@example 3361vc:80Cx24C 3362@end example 3363@item pty 3364[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3365@item none 3366No device is allocated. 3367@item null 3368void device 3369@item chardev:@var{id} 3370Use a named character device defined with the @code{-chardev} option. 3371@item /dev/XXX 3372[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3373parameters are set according to the emulated ones. 3374@item /dev/parport@var{N} 3375[Linux only, parallel port only] Use host parallel port 3376@var{N}. Currently SPP and EPP parallel port features can be used. 3377@item file:@var{filename} 3378Write output to @var{filename}. No character can be read. 3379@item stdio 3380[Unix only] standard input/output 3381@item pipe:@var{filename} 3382name pipe @var{filename} 3383@item COM@var{n} 3384[Windows only] Use host serial port @var{n} 3385@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3386This implements UDP Net Console. 3387When @var{remote_host} or @var{src_ip} are not specified 3388they default to @code{0.0.0.0}. 3389When not using a specified @var{src_port} a random port is automatically chosen. 3390 3391If you just want a simple readonly console you can use @code{netcat} or 3392@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3393@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3394will appear in the netconsole session. 3395 3396If you plan to send characters back via netconsole or you want to stop 3397and start QEMU a lot of times, you should have QEMU use the same 3398source port each time by using something like @code{-serial 3399udp::4555@@:4556} to QEMU. Another approach is to use a patched 3400version of netcat which can listen to a TCP port and send and receive 3401characters via udp. If you have a patched version of netcat which 3402activates telnet remote echo and single char transfer, then you can 3403use the following options to set up a netcat redirector to allow 3404telnet on port 5555 to access the QEMU port. 3405@table @code 3406@item QEMU Options: 3407-serial udp::4555@@:4556 3408@item netcat options: 3409-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3410@item telnet options: 3411localhost 5555 3412@end table 3413 3414@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3415The TCP Net Console has two modes of operation. It can send the serial 3416I/O to a location or wait for a connection from a location. By default 3417the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3418the @var{server} option QEMU will wait for a client socket application 3419to connect to the port before continuing, unless the @code{nowait} 3420option was specified. The @code{nodelay} option disables the Nagle buffering 3421algorithm. The @code{reconnect} option only applies if @var{noserver} is 3422set, if the connection goes down it will attempt to reconnect at the 3423given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3424one TCP connection at a time is accepted. You can use @code{telnet} to 3425connect to the corresponding character device. 3426@table @code 3427@item Example to send tcp console to 192.168.0.2 port 4444 3428-serial tcp:192.168.0.2:4444 3429@item Example to listen and wait on port 4444 for connection 3430-serial tcp::4444,server 3431@item Example to not wait and listen on ip 192.168.0.100 port 4444 3432-serial tcp:192.168.0.100:4444,server,nowait 3433@end table 3434 3435@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3436The telnet protocol is used instead of raw tcp sockets. The options 3437work the same as if you had specified @code{-serial tcp}. The 3438difference is that the port acts like a telnet server or client using 3439telnet option negotiation. This will also allow you to send the 3440MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3441sequence. Typically in unix telnet you do it with Control-] and then 3442type "send break" followed by pressing the enter key. 3443 3444@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3445The WebSocket protocol is used instead of raw tcp socket. The port acts as 3446a WebSocket server. Client mode is not supported. 3447 3448@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3449A unix domain socket is used instead of a tcp socket. The option works the 3450same as if you had specified @code{-serial tcp} except the unix domain socket 3451@var{path} is used for connections. 3452 3453@item mon:@var{dev_string} 3454This is a special option to allow the monitor to be multiplexed onto 3455another serial port. The monitor is accessed with key sequence of 3456@key{Control-a} and then pressing @key{c}. 3457@var{dev_string} should be any one of the serial devices specified 3458above. An example to multiplex the monitor onto a telnet server 3459listening on port 4444 would be: 3460@table @code 3461@item -serial mon:telnet::4444,server,nowait 3462@end table 3463When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3464QEMU any more but will be passed to the guest instead. 3465 3466@item braille 3467Braille device. This will use BrlAPI to display the braille output on a real 3468or fake device. 3469 3470@item msmouse 3471Three button serial mouse. Configure the guest to use Microsoft protocol. 3472@end table 3473ETEXI 3474 3475DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3476 "-parallel dev redirect the parallel port to char device 'dev'\n", 3477 QEMU_ARCH_ALL) 3478STEXI 3479@item -parallel @var{dev} 3480@findex -parallel 3481Redirect the virtual parallel port to host device @var{dev} (same 3482devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3483be used to use hardware devices connected on the corresponding host 3484parallel port. 3485 3486This option can be used several times to simulate up to 3 parallel 3487ports. 3488 3489Use @code{-parallel none} to disable all parallel ports. 3490ETEXI 3491 3492DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3493 "-monitor dev redirect the monitor to char device 'dev'\n", 3494 QEMU_ARCH_ALL) 3495STEXI 3496@item -monitor @var{dev} 3497@findex -monitor 3498Redirect the monitor to host device @var{dev} (same devices as the 3499serial port). 3500The default device is @code{vc} in graphical mode and @code{stdio} in 3501non graphical mode. 3502Use @code{-monitor none} to disable the default monitor. 3503ETEXI 3504DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3505 "-qmp dev like -monitor but opens in 'control' mode\n", 3506 QEMU_ARCH_ALL) 3507STEXI 3508@item -qmp @var{dev} 3509@findex -qmp 3510Like -monitor but opens in 'control' mode. 3511ETEXI 3512DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3513 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3514 QEMU_ARCH_ALL) 3515STEXI 3516@item -qmp-pretty @var{dev} 3517@findex -qmp-pretty 3518Like -qmp but uses pretty JSON formatting. 3519ETEXI 3520 3521DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3522 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3523STEXI 3524@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3525@findex -mon 3526Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3527easing human reading and debugging. 3528ETEXI 3529 3530DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3531 "-debugcon dev redirect the debug console to char device 'dev'\n", 3532 QEMU_ARCH_ALL) 3533STEXI 3534@item -debugcon @var{dev} 3535@findex -debugcon 3536Redirect the debug console to host device @var{dev} (same devices as the 3537serial port). The debug console is an I/O port which is typically port 35380xe9; writing to that I/O port sends output to this device. 3539The default device is @code{vc} in graphical mode and @code{stdio} in 3540non graphical mode. 3541ETEXI 3542 3543DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3544 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3545STEXI 3546@item -pidfile @var{file} 3547@findex -pidfile 3548Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3549from a script. 3550ETEXI 3551 3552DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3553 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3554STEXI 3555@item -singlestep 3556@findex -singlestep 3557Run the emulation in single step mode. 3558ETEXI 3559 3560DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3561 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3562 QEMU_ARCH_ALL) 3563STEXI 3564@item --preconfig 3565@findex --preconfig 3566Pause QEMU for interactive configuration before the machine is created, 3567which allows querying and configuring properties that will affect 3568machine initialization. Use QMP command 'x-exit-preconfig' to exit 3569the preconfig state and move to the next state (i.e. run guest if -S 3570isn't used or pause the second time if -S is used). This option is 3571experimental. 3572ETEXI 3573 3574DEF("S", 0, QEMU_OPTION_S, \ 3575 "-S freeze CPU at startup (use 'c' to start execution)\n", 3576 QEMU_ARCH_ALL) 3577STEXI 3578@item -S 3579@findex -S 3580Do not start CPU at startup (you must type 'c' in the monitor). 3581ETEXI 3582 3583DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3584 "-realtime [mlock=on|off]\n" 3585 " run qemu with realtime features\n" 3586 " mlock=on|off controls mlock support (default: on)\n", 3587 QEMU_ARCH_ALL) 3588STEXI 3589@item -realtime mlock=on|off 3590@findex -realtime 3591Run qemu with realtime features. 3592mlocking qemu and guest memory can be enabled via @option{mlock=on} 3593(enabled by default). 3594ETEXI 3595 3596DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3597 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3598 " run qemu with overcommit hints\n" 3599 " mem-lock=on|off controls memory lock support (default: off)\n" 3600 " cpu-pm=on|off controls cpu power management (default: off)\n", 3601 QEMU_ARCH_ALL) 3602STEXI 3603@item -overcommit mem-lock=on|off 3604@item -overcommit cpu-pm=on|off 3605@findex -overcommit 3606Run qemu with hints about host resource overcommit. The default is 3607to assume that host overcommits all resources. 3608 3609Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3610by default). This works when host memory is not overcommitted and reduces the 3611worst-case latency for guest. This is equivalent to @option{realtime}. 3612 3613Guest ability to manage power state of host cpus (increasing latency for other 3614processes on the same host cpu, but decreasing latency for guest) can be 3615enabled via @option{cpu-pm=on} (disabled by default). This works best when 3616host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3617utilization will be incorrect, not taking into account guest idle time. 3618ETEXI 3619 3620DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3621 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3622STEXI 3623@item -gdb @var{dev} 3624@findex -gdb 3625Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3626connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3627stdio are reasonable use case. The latter is allowing to start QEMU from 3628within gdb and establish the connection via a pipe: 3629@example 3630(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3631@end example 3632ETEXI 3633 3634DEF("s", 0, QEMU_OPTION_s, \ 3635 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3636 QEMU_ARCH_ALL) 3637STEXI 3638@item -s 3639@findex -s 3640Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3641(@pxref{gdb_usage}). 3642ETEXI 3643 3644DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3645 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3646 QEMU_ARCH_ALL) 3647STEXI 3648@item -d @var{item1}[,...] 3649@findex -d 3650Enable logging of specified items. Use '-d help' for a list of log items. 3651ETEXI 3652 3653DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3654 "-D logfile output log to logfile (default stderr)\n", 3655 QEMU_ARCH_ALL) 3656STEXI 3657@item -D @var{logfile} 3658@findex -D 3659Output log in @var{logfile} instead of to stderr 3660ETEXI 3661 3662DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3663 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3664 QEMU_ARCH_ALL) 3665STEXI 3666@item -dfilter @var{range1}[,...] 3667@findex -dfilter 3668Filter debug output to that relevant to a range of target addresses. The filter 3669spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3670@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3671addresses and sizes required. For example: 3672@example 3673 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3674@end example 3675Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3676the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3677block starting at 0xffffffc00005f000. 3678ETEXI 3679 3680DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3681 "-seed number seed the pseudo-random number generator\n", 3682 QEMU_ARCH_ALL) 3683STEXI 3684@item -seed @var{number} 3685@findex -seed 3686Force the guest to use a deterministic pseudo-random number generator, seeded 3687with @var{number}. This does not affect crypto routines within the host. 3688ETEXI 3689 3690DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3691 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3692 QEMU_ARCH_ALL) 3693STEXI 3694@item -L @var{path} 3695@findex -L 3696Set the directory for the BIOS, VGA BIOS and keymaps. 3697 3698To list all the data directories, use @code{-L help}. 3699ETEXI 3700 3701DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3702 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3703STEXI 3704@item -bios @var{file} 3705@findex -bios 3706Set the filename for the BIOS. 3707ETEXI 3708 3709DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3710 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3711STEXI 3712@item -enable-kvm 3713@findex -enable-kvm 3714Enable KVM full virtualization support. This option is only available 3715if KVM support is enabled when compiling. 3716ETEXI 3717 3718DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3719 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3720DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3721 "-xen-attach attach to existing xen domain\n" 3722 " libxl will use this when starting QEMU\n", 3723 QEMU_ARCH_ALL) 3724DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3725 "-xen-domid-restrict restrict set of available xen operations\n" 3726 " to specified domain id. (Does not affect\n" 3727 " xenpv machine type).\n", 3728 QEMU_ARCH_ALL) 3729STEXI 3730@item -xen-domid @var{id} 3731@findex -xen-domid 3732Specify xen guest domain @var{id} (XEN only). 3733@item -xen-attach 3734@findex -xen-attach 3735Attach to existing xen domain. 3736libxl will use this when starting QEMU (XEN only). 3737@findex -xen-domid-restrict 3738Restrict set of available xen operations to specified domain id (XEN only). 3739ETEXI 3740 3741DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3742 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3743STEXI 3744@item -no-reboot 3745@findex -no-reboot 3746Exit instead of rebooting. 3747ETEXI 3748 3749DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3750 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3751STEXI 3752@item -no-shutdown 3753@findex -no-shutdown 3754Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3755This allows for instance switching to monitor to commit changes to the 3756disk image. 3757ETEXI 3758 3759DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3760 "-loadvm [tag|id]\n" \ 3761 " start right away with a saved state (loadvm in monitor)\n", 3762 QEMU_ARCH_ALL) 3763STEXI 3764@item -loadvm @var{file} 3765@findex -loadvm 3766Start right away with a saved state (@code{loadvm} in monitor) 3767ETEXI 3768 3769#ifndef _WIN32 3770DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3771 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3772#endif 3773STEXI 3774@item -daemonize 3775@findex -daemonize 3776Daemonize the QEMU process after initialization. QEMU will not detach from 3777standard IO until it is ready to receive connections on any of its devices. 3778This option is a useful way for external programs to launch QEMU without having 3779to cope with initialization race conditions. 3780ETEXI 3781 3782DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3783 "-option-rom rom load a file, rom, into the option ROM space\n", 3784 QEMU_ARCH_ALL) 3785STEXI 3786@item -option-rom @var{file} 3787@findex -option-rom 3788Load the contents of @var{file} as an option ROM. 3789This option is useful to load things like EtherBoot. 3790ETEXI 3791 3792DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3793 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3794 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3795 QEMU_ARCH_ALL) 3796 3797STEXI 3798 3799@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3800@findex -rtc 3801Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3802UTC or local time, respectively. @code{localtime} is required for correct date in 3803MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3804format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3805 3806By default the RTC is driven by the host system time. This allows using of the 3807RTC as accurate reference clock inside the guest, specifically if the host 3808time is smoothly following an accurate external reference clock, e.g. via NTP. 3809If you want to isolate the guest time from the host, you can set @option{clock} 3810to @code{rt} instead, which provides a host monotonic clock if host support it. 3811To even prevent the RTC from progressing during suspension, you can set @option{clock} 3812to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3813icount mode in order to preserve determinism; however, note that in icount mode 3814the speed of the virtual clock is variable and can in general differ from the 3815host clock. 3816 3817Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3818specifically with Windows' ACPI HAL. This option will try to figure out how 3819many timer interrupts were not processed by the Windows guest and will 3820re-inject them. 3821ETEXI 3822 3823DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3824 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3825 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3826 " instruction, enable aligning the host and virtual clocks\n" \ 3827 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3828STEXI 3829@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3830@findex -icount 3831Enable virtual instruction counter. The virtual cpu will execute one 3832instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3833then the virtual cpu speed will be automatically adjusted to keep virtual 3834time within a few seconds of real time. 3835 3836When the virtual cpu is sleeping, the virtual time will advance at default 3837speed unless @option{sleep=on|off} is specified. 3838With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3839instantly whenever the virtual cpu goes to sleep mode and will not advance 3840if no timer is enabled. This behavior give deterministic execution times from 3841the guest point of view. 3842 3843Note that while this option can give deterministic behavior, it does not 3844provide cycle accurate emulation. Modern CPUs contain superscalar out of 3845order cores with complex cache hierarchies. The number of instructions 3846executed often has little or no correlation with actual performance. 3847 3848@option{align=on} will activate the delay algorithm which will try 3849to synchronise the host clock and the virtual clock. The goal is to 3850have a guest running at the real frequency imposed by the shift option. 3851Whenever the guest clock is behind the host clock and if 3852@option{align=on} is specified then we print a message to the user 3853to inform about the delay. 3854Currently this option does not work when @option{shift} is @code{auto}. 3855Note: The sync algorithm will work for those shift values for which 3856the guest clock runs ahead of the host clock. Typically this happens 3857when the shift value is high (how high depends on the host machine). 3858 3859When @option{rr} option is specified deterministic record/replay is enabled. 3860Replay log is written into @var{filename} file in record mode and 3861read from this file in replay mode. 3862 3863Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3864at the start of execution recording. In replay mode this option is used 3865to load the initial VM state. 3866ETEXI 3867 3868DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3869 "-watchdog model\n" \ 3870 " enable virtual hardware watchdog [default=none]\n", 3871 QEMU_ARCH_ALL) 3872STEXI 3873@item -watchdog @var{model} 3874@findex -watchdog 3875Create a virtual hardware watchdog device. Once enabled (by a guest 3876action), the watchdog must be periodically polled by an agent inside 3877the guest or else the guest will be restarted. Choose a model for 3878which your guest has drivers. 3879 3880The @var{model} is the model of hardware watchdog to emulate. Use 3881@code{-watchdog help} to list available hardware models. Only one 3882watchdog can be enabled for a guest. 3883 3884The following models may be available: 3885@table @option 3886@item ib700 3887iBASE 700 is a very simple ISA watchdog with a single timer. 3888@item i6300esb 3889Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3890dual-timer watchdog. 3891@item diag288 3892A virtual watchdog for s390x backed by the diagnose 288 hypercall 3893(currently KVM only). 3894@end table 3895ETEXI 3896 3897DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3898 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3899 " action when watchdog fires [default=reset]\n", 3900 QEMU_ARCH_ALL) 3901STEXI 3902@item -watchdog-action @var{action} 3903@findex -watchdog-action 3904 3905The @var{action} controls what QEMU will do when the watchdog timer 3906expires. 3907The default is 3908@code{reset} (forcefully reset the guest). 3909Other possible actions are: 3910@code{shutdown} (attempt to gracefully shutdown the guest), 3911@code{poweroff} (forcefully poweroff the guest), 3912@code{inject-nmi} (inject a NMI into the guest), 3913@code{pause} (pause the guest), 3914@code{debug} (print a debug message and continue), or 3915@code{none} (do nothing). 3916 3917Note that the @code{shutdown} action requires that the guest responds 3918to ACPI signals, which it may not be able to do in the sort of 3919situations where the watchdog would have expired, and thus 3920@code{-watchdog-action shutdown} is not recommended for production use. 3921 3922Examples: 3923 3924@table @code 3925@item -watchdog i6300esb -watchdog-action pause 3926@itemx -watchdog ib700 3927@end table 3928ETEXI 3929 3930DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3931 "-echr chr set terminal escape character instead of ctrl-a\n", 3932 QEMU_ARCH_ALL) 3933STEXI 3934 3935@item -echr @var{numeric_ascii_value} 3936@findex -echr 3937Change the escape character used for switching to the monitor when using 3938monitor and serial sharing. The default is @code{0x01} when using the 3939@code{-nographic} option. @code{0x01} is equal to pressing 3940@code{Control-a}. You can select a different character from the ascii 3941control keys where 1 through 26 map to Control-a through Control-z. For 3942instance you could use the either of the following to change the escape 3943character to Control-t. 3944@table @code 3945@item -echr 0x14 3946@itemx -echr 20 3947@end table 3948ETEXI 3949 3950DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3951 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3952STEXI 3953@item -show-cursor 3954@findex -show-cursor 3955Show cursor. 3956ETEXI 3957 3958DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3959 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3960STEXI 3961@item -tb-size @var{n} 3962@findex -tb-size 3963Set TB size. 3964ETEXI 3965 3966DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3967 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3968 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3969 "-incoming unix:socketpath\n" \ 3970 " prepare for incoming migration, listen on\n" \ 3971 " specified protocol and socket address\n" \ 3972 "-incoming fd:fd\n" \ 3973 "-incoming exec:cmdline\n" \ 3974 " accept incoming migration on given file descriptor\n" \ 3975 " or from given external command\n" \ 3976 "-incoming defer\n" \ 3977 " wait for the URI to be specified via migrate_incoming\n", 3978 QEMU_ARCH_ALL) 3979STEXI 3980@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3981@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3982@findex -incoming 3983Prepare for incoming migration, listen on a given tcp port. 3984 3985@item -incoming unix:@var{socketpath} 3986Prepare for incoming migration, listen on a given unix socket. 3987 3988@item -incoming fd:@var{fd} 3989Accept incoming migration from a given filedescriptor. 3990 3991@item -incoming exec:@var{cmdline} 3992Accept incoming migration as an output from specified external command. 3993 3994@item -incoming defer 3995Wait for the URI to be specified via migrate_incoming. The monitor can 3996be used to change settings (such as migration parameters) prior to issuing 3997the migrate_incoming to allow the migration to begin. 3998ETEXI 3999 4000DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4001 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4002STEXI 4003@item -only-migratable 4004@findex -only-migratable 4005Only allow migratable devices. Devices will not be allowed to enter an 4006unmigratable state. 4007ETEXI 4008 4009DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4010 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4011STEXI 4012@item -nodefaults 4013@findex -nodefaults 4014Don't create default devices. Normally, QEMU sets the default devices like serial 4015port, parallel port, virtual console, monitor device, VGA adapter, floppy and 4016CD-ROM drive and others. The @code{-nodefaults} option will disable all those 4017default devices. 4018ETEXI 4019 4020#ifndef _WIN32 4021DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4022 "-chroot dir chroot to dir just before starting the VM\n", 4023 QEMU_ARCH_ALL) 4024#endif 4025STEXI 4026@item -chroot @var{dir} 4027@findex -chroot 4028Immediately before starting guest execution, chroot to the specified 4029directory. Especially useful in combination with -runas. 4030ETEXI 4031 4032#ifndef _WIN32 4033DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4034 "-runas user change to user id user just before starting the VM\n" \ 4035 " user can be numeric uid:gid instead\n", 4036 QEMU_ARCH_ALL) 4037#endif 4038STEXI 4039@item -runas @var{user} 4040@findex -runas 4041Immediately before starting guest execution, drop root privileges, switching 4042to the specified user. 4043ETEXI 4044 4045DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4046 "-prom-env variable=value\n" 4047 " set OpenBIOS nvram variables\n", 4048 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4049STEXI 4050@item -prom-env @var{variable}=@var{value} 4051@findex -prom-env 4052Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4053ETEXI 4054DEF("semihosting", 0, QEMU_OPTION_semihosting, 4055 "-semihosting semihosting mode\n", 4056 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4057 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4058STEXI 4059@item -semihosting 4060@findex -semihosting 4061Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4062ETEXI 4063DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4064 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4065 " semihosting configuration\n", 4066QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4067QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4068STEXI 4069@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4070@findex -semihosting-config 4071Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4072@table @option 4073@item target=@code{native|gdb|auto} 4074Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4075or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4076during debug sessions and @code{native} otherwise. 4077@item chardev=@var{str1} 4078Send the output to a chardev backend output for native or auto output when not in gdb 4079@item arg=@var{str1},arg=@var{str2},... 4080Allows the user to pass input arguments, and can be used multiple times to build 4081up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4082command line is still supported for backward compatibility. If both the 4083@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4084specified, the former is passed to semihosting as it always takes precedence. 4085@end table 4086ETEXI 4087DEF("old-param", 0, QEMU_OPTION_old_param, 4088 "-old-param old param mode\n", QEMU_ARCH_ARM) 4089STEXI 4090@item -old-param 4091@findex -old-param (ARM) 4092Old param mode (ARM only). 4093ETEXI 4094 4095DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4096 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4097 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4098 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4099 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4100 " by the kernel, but typically no longer used by modern\n" \ 4101 " C library implementations.\n" \ 4102 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4103 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4104 " The value 'children' will deny set*uid|gid system calls for\n" \ 4105 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4106 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4107 " blacklisting *fork and execve\n" \ 4108 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4109 QEMU_ARCH_ALL) 4110STEXI 4111@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4112@findex -sandbox 4113Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4114disable it. The default is 'off'. 4115@table @option 4116@item obsolete=@var{string} 4117Enable Obsolete system calls 4118@item elevateprivileges=@var{string} 4119Disable set*uid|gid system calls 4120@item spawn=@var{string} 4121Disable *fork and execve 4122@item resourcecontrol=@var{string} 4123Disable process affinity and schedular priority 4124@end table 4125ETEXI 4126 4127DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4128 "-readconfig <file>\n", QEMU_ARCH_ALL) 4129STEXI 4130@item -readconfig @var{file} 4131@findex -readconfig 4132Read device configuration from @var{file}. This approach is useful when you want to spawn 4133QEMU process with many command line options but you don't want to exceed the command line 4134character limit. 4135ETEXI 4136DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4137 "-writeconfig <file>\n" 4138 " read/write config file\n", QEMU_ARCH_ALL) 4139STEXI 4140@item -writeconfig @var{file} 4141@findex -writeconfig 4142Write device configuration to @var{file}. The @var{file} can be either filename to save 4143command line and device configuration into file or dash @code{-}) character to print the 4144output to stdout. This can be later used as input file for @code{-readconfig} option. 4145ETEXI 4146 4147DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4148 "-no-user-config\n" 4149 " do not load default user-provided config files at startup\n", 4150 QEMU_ARCH_ALL) 4151STEXI 4152@item -no-user-config 4153@findex -no-user-config 4154The @code{-no-user-config} option makes QEMU not load any of the user-provided 4155config files on @var{sysconfdir}. 4156ETEXI 4157 4158DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4159 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4160 " specify tracing options\n", 4161 QEMU_ARCH_ALL) 4162STEXI 4163HXCOMM This line is not accurate, as some sub-options are backend-specific but 4164HXCOMM HX does not support conditional compilation of text. 4165@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4166@findex -trace 4167@include qemu-option-trace.texi 4168ETEXI 4169 4170HXCOMM Internal use 4171DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4172DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4173 4174#ifdef __linux__ 4175DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4176 "-enable-fips enable FIPS 140-2 compliance\n", 4177 QEMU_ARCH_ALL) 4178#endif 4179STEXI 4180@item -enable-fips 4181@findex -enable-fips 4182Enable FIPS 140-2 compliance mode. 4183ETEXI 4184 4185HXCOMM Deprecated by -accel tcg 4186DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4187 4188DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4189 "-msg timestamp[=on|off]\n" 4190 " change the format of messages\n" 4191 " on|off controls leading timestamps (default:on)\n", 4192 QEMU_ARCH_ALL) 4193STEXI 4194@item -msg timestamp[=on|off] 4195@findex -msg 4196prepend a timestamp to each log message.(default:on) 4197ETEXI 4198 4199DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4200 "-dump-vmstate <file>\n" 4201 " Output vmstate information in JSON format to file.\n" 4202 " Use the scripts/vmstate-static-checker.py file to\n" 4203 " check for possible regressions in migration code\n" 4204 " by comparing two such vmstate dumps.\n", 4205 QEMU_ARCH_ALL) 4206STEXI 4207@item -dump-vmstate @var{file} 4208@findex -dump-vmstate 4209Dump json-encoded vmstate information for current machine type to file 4210in @var{file} 4211ETEXI 4212 4213DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4214 "-enable-sync-profile\n" 4215 " enable synchronization profiling\n", 4216 QEMU_ARCH_ALL) 4217STEXI 4218@item -enable-sync-profile 4219@findex -enable-sync-profile 4220Enable synchronization profiling. 4221ETEXI 4222 4223STEXI 4224@end table 4225ETEXI 4226DEFHEADING() 4227 4228DEFHEADING(Generic object creation:) 4229STEXI 4230@table @option 4231ETEXI 4232 4233DEF("object", HAS_ARG, QEMU_OPTION_object, 4234 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4235 " create a new object of type TYPENAME setting properties\n" 4236 " in the order they are specified. Note that the 'id'\n" 4237 " property must be set. These objects are placed in the\n" 4238 " '/objects' path.\n", 4239 QEMU_ARCH_ALL) 4240STEXI 4241@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4242@findex -object 4243Create a new object of type @var{typename} setting properties 4244in the order they are specified. Note that the 'id' 4245property must be set. These objects are placed in the 4246'/objects' path. 4247 4248@table @option 4249 4250@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},align=@var{align} 4251 4252Creates a memory file backend object, which can be used to back 4253the guest RAM with huge pages. 4254 4255The @option{id} parameter is a unique ID that will be used to reference this 4256memory region when configuring the @option{-numa} argument. 4257 4258The @option{size} option provides the size of the memory region, and accepts 4259common suffixes, eg @option{500M}. 4260 4261The @option{mem-path} provides the path to either a shared memory or huge page 4262filesystem mount. 4263 4264The @option{share} boolean option determines whether the memory 4265region is marked as private to QEMU, or shared. The latter allows 4266a co-operating external process to access the QEMU memory region. 4267 4268The @option{share} is also required for pvrdma devices due to 4269limitations in the RDMA API provided by Linux. 4270 4271Setting share=on might affect the ability to configure NUMA 4272bindings for the memory backend under some circumstances, see 4273Documentation/vm/numa_memory_policy.txt on the Linux kernel 4274source tree for additional details. 4275 4276Setting the @option{discard-data} boolean option to @var{on} 4277indicates that file contents can be destroyed when QEMU exits, 4278to avoid unnecessarily flushing data to the backing file. Note 4279that @option{discard-data} is only an optimization, and QEMU 4280might not discard file contents if it aborts unexpectedly or is 4281terminated using SIGKILL. 4282 4283The @option{merge} boolean option enables memory merge, also known as 4284MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4285memory deduplication. 4286 4287Setting the @option{dump} boolean option to @var{off} excludes the memory from 4288core dumps. This feature is also known as MADV_DONTDUMP. 4289 4290The @option{prealloc} boolean option enables memory preallocation. 4291 4292The @option{host-nodes} option binds the memory range to a list of NUMA host 4293nodes. 4294 4295The @option{policy} option sets the NUMA policy to one of the following values: 4296 4297@table @option 4298@item @var{default} 4299default host policy 4300 4301@item @var{preferred} 4302prefer the given host node list for allocation 4303 4304@item @var{bind} 4305restrict memory allocation to the given host node list 4306 4307@item @var{interleave} 4308interleave memory allocations across the given host node list 4309@end table 4310 4311The @option{align} option specifies the base address alignment when 4312QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4313@option{2M}. Some backend store specified by @option{mem-path} 4314requires an alignment different than the default one used by QEMU, eg 4315the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4316such cases, users can specify the required alignment via this option. 4317 4318The @option{pmem} option specifies whether the backing file specified 4319by @option{mem-path} is in host persistent memory that can be accessed 4320using the SNIA NVM programming model (e.g. Intel NVDIMM). 4321If @option{pmem} is set to 'on', QEMU will take necessary operations to 4322guarantee the persistence of its own writes to @option{mem-path} 4323(e.g. in vNVDIMM label emulation and live migration). 4324Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4325file metadata is in sync for @option{mem-path} in case of host crash 4326or a power failure. MAP_SYNC requires support from both the host kernel 4327(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4328with DAX option. 4329 4330@item -object memory-backend-ram,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave} 4331 4332Creates a memory backend object, which can be used to back the guest RAM. 4333Memory backend objects offer more control than the @option{-m} option that is 4334traditionally used to define guest RAM. Please refer to 4335@option{memory-backend-file} for a description of the options. 4336 4337@item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@var{on|off},share=@var{on|off},prealloc=@var{on|off},size=@var{size},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave},seal=@var{on|off},hugetlb=@var{on|off},hugetlbsize=@var{size} 4338 4339Creates an anonymous memory file backend object, which allows QEMU to 4340share the memory with an external process (e.g. when using 4341vhost-user). The memory is allocated with memfd and optional 4342sealing. (Linux only) 4343 4344The @option{seal} option creates a sealed-file, that will block 4345further resizing the memory ('on' by default). 4346 4347The @option{hugetlb} option specify the file to be created resides in 4348the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4349the @option{hugetlb} option, the @option{hugetlbsize} option specify 4350the hugetlb page size on systems that support multiple hugetlb page 4351sizes (it must be a power of 2 value supported by the system). 4352 4353In some versions of Linux, the @option{hugetlb} option is incompatible 4354with the @option{seal} option (requires at least Linux 4.16). 4355 4356Please refer to @option{memory-backend-file} for a description of the 4357other options. 4358 4359The @option{share} boolean option is @var{on} by default with memfd. 4360 4361@item -object rng-builtin,id=@var{id} 4362 4363Creates a random number generator backend which obtains entropy from 4364QEMU builtin functions. The @option{id} parameter is a unique ID that 4365will be used to reference this entropy backend from the @option{virtio-rng} 4366device. By default, the @option{virtio-rng} device uses this RNG backend. 4367 4368@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4369 4370Creates a random number generator backend which obtains entropy from 4371a device on the host. The @option{id} parameter is a unique ID that 4372will be used to reference this entropy backend from the @option{virtio-rng} 4373device. The @option{filename} parameter specifies which file to obtain 4374entropy from and if omitted defaults to @option{/dev/urandom}. 4375 4376@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4377 4378Creates a random number generator backend which obtains entropy from 4379an external daemon running on the host. The @option{id} parameter is 4380a unique ID that will be used to reference this entropy backend from 4381the @option{virtio-rng} device. The @option{chardev} parameter is 4382the unique ID of a character device backend that provides the connection 4383to the RNG daemon. 4384 4385@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4386 4387Creates a TLS anonymous credentials object, which can be used to provide 4388TLS support on network backends. The @option{id} parameter is a unique 4389ID which network backends will use to access the credentials. The 4390@option{endpoint} is either @option{server} or @option{client} depending 4391on whether the QEMU network backend that uses the credentials will be 4392acting as a client or as a server. If @option{verify-peer} is enabled 4393(the default) then once the handshake is completed, the peer credentials 4394will be verified, though this is a no-op for anonymous credentials. 4395 4396The @var{dir} parameter tells QEMU where to find the credential 4397files. For server endpoints, this directory may contain a file 4398@var{dh-params.pem} providing diffie-hellman parameters to use 4399for the TLS server. If the file is missing, QEMU will generate 4400a set of DH parameters at startup. This is a computationally 4401expensive operation that consumes random pool entropy, so it is 4402recommended that a persistent set of parameters be generated 4403upfront and saved. 4404 4405@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4406 4407Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4408TLS support on network backends. The @option{id} parameter is a unique 4409ID which network backends will use to access the credentials. The 4410@option{endpoint} is either @option{server} or @option{client} depending 4411on whether the QEMU network backend that uses the credentials will be 4412acting as a client or as a server. For clients only, @option{username} 4413is the username which will be sent to the server. If omitted 4414it defaults to ``qemu''. 4415 4416The @var{dir} parameter tells QEMU where to find the keys file. 4417It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4418pairs. This file can most easily be created using the GnuTLS 4419@code{psktool} program. 4420 4421For server endpoints, @var{dir} may also contain a file 4422@var{dh-params.pem} providing diffie-hellman parameters to use 4423for the TLS server. If the file is missing, QEMU will generate 4424a set of DH parameters at startup. This is a computationally 4425expensive operation that consumes random pool entropy, so it is 4426recommended that a persistent set of parameters be generated 4427up front and saved. 4428 4429@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},priority=@var{priority},verify-peer=@var{on|off},passwordid=@var{id} 4430 4431Creates a TLS anonymous credentials object, which can be used to provide 4432TLS support on network backends. The @option{id} parameter is a unique 4433ID which network backends will use to access the credentials. The 4434@option{endpoint} is either @option{server} or @option{client} depending 4435on whether the QEMU network backend that uses the credentials will be 4436acting as a client or as a server. If @option{verify-peer} is enabled 4437(the default) then once the handshake is completed, the peer credentials 4438will be verified. With x509 certificates, this implies that the clients 4439must be provided with valid client certificates too. 4440 4441The @var{dir} parameter tells QEMU where to find the credential 4442files. For server endpoints, this directory may contain a file 4443@var{dh-params.pem} providing diffie-hellman parameters to use 4444for the TLS server. If the file is missing, QEMU will generate 4445a set of DH parameters at startup. This is a computationally 4446expensive operation that consumes random pool entropy, so it is 4447recommended that a persistent set of parameters be generated 4448upfront and saved. 4449 4450For x509 certificate credentials the directory will contain further files 4451providing the x509 certificates. The certificates must be stored 4452in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4453@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4454@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4455 4456For the @var{server-key.pem} and @var{client-key.pem} files which 4457contain sensitive private keys, it is possible to use an encrypted 4458version by providing the @var{passwordid} parameter. This provides 4459the ID of a previously created @code{secret} object containing the 4460password for decryption. 4461 4462The @var{priority} parameter allows to override the global default 4463priority used by gnutls. This can be useful if the system administrator 4464needs to use a weaker set of crypto priorities for QEMU without 4465potentially forcing the weakness onto all applications. Or conversely 4466if one wants wants a stronger default for QEMU than for all other 4467applications, they can do this through this parameter. Its format is 4468a gnutls priority string as described at 4469@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4470 4471@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4472 4473Interval @var{t} can't be 0, this filter batches the packet delivery: all 4474packets arriving in a given interval on netdev @var{netdevid} are delayed 4475until the end of the interval. Interval is in microseconds. 4476@option{status} is optional that indicate whether the netfilter is 4477on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4478 4479queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4480 4481@option{all}: the filter is attached both to the receive and the transmit 4482 queue of the netdev (default). 4483 4484@option{rx}: the filter is attached to the receive queue of the netdev, 4485 where it will receive packets sent to the netdev. 4486 4487@option{tx}: the filter is attached to the transmit queue of the netdev, 4488 where it will receive packets sent by the netdev. 4489 4490@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4491 4492filter-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. 4493 4494@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4495 4496filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4497@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4498filter-redirector will redirect packet with vnet_hdr_len. 4499Create a filter-redirector we need to differ outdev id from indev id, id can not 4500be the same. we can just use indev or outdev, but at least one of indev or outdev 4501need to be specified. 4502 4503@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4504 4505Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4506secondary from primary to keep secondary tcp connection,and rewrite 4507tcp packet to primary from secondary make tcp packet can be handled by 4508client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4509 4510usage: 4511colo secondary: 4512-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4513-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4514-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4515 4516@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4517 4518Dump the network traffic on netdev @var{dev} to the file specified by 4519@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4520The file format is libpcap, so it can be analyzed with tools such as tcpdump 4521or Wireshark. 4522 4523@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid},iothread=@var{id}[,vnet_hdr_support][,notify_dev=@var{id}] 4524 4525Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4526secondary packet. If the packets are same, we will output primary 4527packet to outdev@var{chardevid}, else we will notify colo-frame 4528do checkpoint and send primary packet to outdev@var{chardevid}. 4529In order to improve efficiency, we need to put the task of comparison 4530in another thread. If it has the vnet_hdr_support flag, colo compare 4531will send/recv packet with vnet_hdr_len. 4532If you want to use Xen COLO, will need the notify_dev to notify Xen 4533colo-frame to do checkpoint. 4534 4535we must use it with the help of filter-mirror and filter-redirector. 4536 4537@example 4538 4539KVM COLO 4540 4541primary: 4542-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4543-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4544-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4545-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4546-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4547-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4548-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4549-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4550-object iothread,id=iothread1 4551-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4552-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4553-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4554-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4555 4556secondary: 4557-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4558-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4559-chardev socket,id=red0,host=3.3.3.3,port=9003 4560-chardev socket,id=red1,host=3.3.3.3,port=9004 4561-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4562-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4563 4564 4565Xen COLO 4566 4567primary: 4568-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4569-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4570-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4571-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4572-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4573-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4574-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4575-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4576-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4577-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4578-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4579-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4580-object iothread,id=iothread1 4581-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4582 4583secondary: 4584-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4585-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4586-chardev socket,id=red0,host=3.3.3.3,port=9003 4587-chardev socket,id=red1,host=3.3.3.3,port=9004 4588-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4589-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4590 4591@end example 4592 4593If you want to know the detail of above command line, you can read 4594the colo-compare git log. 4595 4596@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4597 4598Creates a cryptodev backend which executes crypto opreation from 4599the QEMU cipher APIS. The @var{id} parameter is 4600a unique ID that will be used to reference this cryptodev backend from 4601the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4602which specify the queue number of cryptodev backend, the default of 4603@var{queues} is 1. 4604 4605@example 4606 4607 # @value{qemu_system} \ 4608 [...] \ 4609 -object cryptodev-backend-builtin,id=cryptodev0 \ 4610 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4611 [...] 4612@end example 4613 4614@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4615 4616Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4617The @var{id} parameter is a unique ID that will be used to reference this 4618cryptodev backend from the @option{virtio-crypto} device. 4619The chardev should be a unix domain socket backed one. The vhost-user uses 4620a specifically defined protocol to pass vhost ioctl replacement messages 4621to an application on the other end of the socket. 4622The @var{queues} parameter is optional, which specify the queue number 4623of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4624 4625@example 4626 4627 # @value{qemu_system} \ 4628 [...] \ 4629 -chardev socket,id=chardev0,path=/path/to/socket \ 4630 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4631 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4632 [...] 4633@end example 4634 4635@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4636@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4637 4638Defines a secret to store a password, encryption key, or some other sensitive 4639data. The sensitive data can either be passed directly via the @var{data} 4640parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4641parameter is insecure unless the sensitive data is encrypted. 4642 4643The sensitive data can be provided in raw format (the default), or base64. 4644When encoded as JSON, the raw format only supports valid UTF-8 characters, 4645so base64 is recommended for sending binary data. QEMU will convert from 4646which ever format is provided to the format it needs internally. eg, an 4647RBD password can be provided in raw format, even though it will be base64 4648encoded when passed onto the RBD sever. 4649 4650For added protection, it is possible to encrypt the data associated with 4651a secret using the AES-256-CBC cipher. Use of encryption is indicated 4652by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4653parameter provides the ID of a previously defined secret that contains 4654the AES-256 decryption key. This key should be 32-bytes long and be 4655base64 encoded. The @var{iv} parameter provides the random initialization 4656vector used for encryption of this particular secret and should be a 4657base64 encrypted string of the 16-byte IV. 4658 4659The simplest (insecure) usage is to provide the secret inline 4660 4661@example 4662 4663 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4664 4665@end example 4666 4667The simplest secure usage is to provide the secret via a file 4668 4669 # printf "letmein" > mypasswd.txt 4670 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4671 4672For greater security, AES-256-CBC should be used. To illustrate usage, 4673consider the openssl command line tool which can encrypt the data. Note 4674that when encrypting, the plaintext must be padded to the cipher block 4675size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4676 4677First a master key needs to be created in base64 encoding: 4678 4679@example 4680 # openssl rand -base64 32 > key.b64 4681 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4682@end example 4683 4684Each secret to be encrypted needs to have a random initialization vector 4685generated. These do not need to be kept secret 4686 4687@example 4688 # openssl rand -base64 16 > iv.b64 4689 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4690@end example 4691 4692The secret to be defined can now be encrypted, in this case we're 4693telling openssl to base64 encode the result, but it could be left 4694as raw bytes if desired. 4695 4696@example 4697 # SECRET=$(printf "letmein" | 4698 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4699@end example 4700 4701When launching QEMU, create a master secret pointing to @code{key.b64} 4702and specify that to be used to decrypt the user password. Pass the 4703contents of @code{iv.b64} to the second secret 4704 4705@example 4706 # @value{qemu_system} \ 4707 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4708 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4709 data=$SECRET,iv=$(<iv.b64) 4710@end example 4711 4712@item -object sev-guest,id=@var{id},cbitpos=@var{cbitpos},reduced-phys-bits=@var{val},[sev-device=@var{string},policy=@var{policy},handle=@var{handle},dh-cert-file=@var{file},session-file=@var{file}] 4713 4714Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4715to provide the guest memory encryption support on AMD processors. 4716 4717When memory encryption is enabled, one of the physical address bit (aka the 4718C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4719is used to provide the C-bit position. The C-bit position is Host family dependent 4720hence user must provide this value. On EPYC, the value should be 47. 4721 4722When memory encryption is enabled, we loose certain bits in physical address space. 4723The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4724physical address space. Similar to C-bit, the value is Host family dependent. 4725On EPYC, the value should be 5. 4726 4727The @option{sev-device} provides the device file to use for communicating with 4728the SEV firmware running inside AMD Secure Processor. The default device is 4729'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4730created by CCP driver. 4731 4732The @option{policy} provides the guest policy to be enforced by the SEV firmware 4733and restrict what configuration and operational commands can be performed on this 4734guest by the hypervisor. The policy should be provided by the guest owner and is 4735bound to the guest and cannot be changed throughout the lifetime of the guest. 4736The default is 0. 4737 4738If guest @option{policy} allows sharing the key with another SEV guest then 4739@option{handle} can be use to provide handle of the guest from which to share 4740the key. 4741 4742The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4743Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4744are used for establishing a cryptographic session with the guest owner to 4745negotiate keys used for attestation. The file must be encoded in base64. 4746 4747e.g to launch a SEV guest 4748@example 4749 # @value{qemu_system_x86} \ 4750 ...... 4751 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4752 -machine ...,memory-encryption=sev0 4753 ..... 4754 4755@end example 4756 4757 4758@item -object authz-simple,id=@var{id},identity=@var{string} 4759 4760Create an authorization object that will control access to network services. 4761 4762The @option{identity} parameter is identifies the user and its format 4763depends on the network service that authorization object is associated 4764with. For authorizing based on TLS x509 certificates, the identity must 4765be the x509 distinguished name. Note that care must be taken to escape 4766any commas in the distinguished name. 4767 4768An example authorization object to validate a x509 distinguished name 4769would look like: 4770@example 4771 # @value{qemu_system} \ 4772 ... 4773 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4774 ... 4775@end example 4776 4777Note the use of quotes due to the x509 distinguished name containing 4778whitespace, and escaping of ','. 4779 4780@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4781 4782Create an authorization object that will control access to network services. 4783 4784The @option{filename} parameter is the fully qualified path to a file 4785containing the access control list rules in JSON format. 4786 4787An example set of rules that match against SASL usernames might look 4788like: 4789 4790@example 4791 @{ 4792 "rules": [ 4793 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4794 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4795 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4796 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4797 ], 4798 "policy": "deny" 4799 @} 4800@end example 4801 4802When checking access the object will iterate over all the rules and 4803the first rule to match will have its @option{policy} value returned 4804as the result. If no rules match, then the default @option{policy} 4805value is returned. 4806 4807The rules can either be an exact string match, or they can use the 4808simple UNIX glob pattern matching to allow wildcards to be used. 4809 4810If @option{refresh} is set to true the file will be monitored 4811and automatically reloaded whenever its content changes. 4812 4813As with the @code{authz-simple} object, the format of the identity 4814strings being matched depends on the network service, but is usually 4815a TLS x509 distinguished name, or a SASL username. 4816 4817An example authorization object to validate a SASL username 4818would look like: 4819@example 4820 # @value{qemu_system} \ 4821 ... 4822 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4823 ... 4824@end example 4825 4826@item -object authz-pam,id=@var{id},service=@var{string} 4827 4828Create an authorization object that will control access to network services. 4829 4830The @option{service} parameter provides the name of a PAM service to use 4831for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4832exist to provide the configuration for the @code{account} subsystem. 4833 4834An example authorization object to validate a TLS x509 distinguished 4835name would look like: 4836 4837@example 4838 # @value{qemu_system} \ 4839 ... 4840 -object authz-pam,id=auth0,service=qemu-vnc 4841 ... 4842@end example 4843 4844There would then be a corresponding config file for PAM at 4845@code{/etc/pam.d/qemu-vnc} that contains: 4846 4847@example 4848account requisite pam_listfile.so item=user sense=allow \ 4849 file=/etc/qemu/vnc.allow 4850@end example 4851 4852Finally the @code{/etc/qemu/vnc.allow} file would contain 4853the list of x509 distingished names that are permitted 4854access 4855 4856@example 4857CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4858@end example 4859 4860 4861@end table 4862 4863ETEXI 4864 4865 4866HXCOMM This is the last statement. Insert new options before this line! 4867STEXI 4868@end table 4869ETEXI 4870
