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]\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}] 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@end table 1407ETEXI 1408 1409DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1410 "-virtfs_synth Create synthetic file system image\n", 1411 QEMU_ARCH_ALL) 1412STEXI 1413@item -virtfs_synth 1414@findex -virtfs_synth 1415Create synthetic file system image. Note that this option is now deprecated. 1416Please use @code{-fsdev synth} and @code{-device virtio-9p-...} instead. 1417ETEXI 1418 1419DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1420 "-iscsi [user=user][,password=password]\n" 1421 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1422 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1423 " [,timeout=timeout]\n" 1424 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1425 1426STEXI 1427@item -iscsi 1428@findex -iscsi 1429Configure iSCSI session parameters. 1430ETEXI 1431 1432STEXI 1433@end table 1434ETEXI 1435DEFHEADING() 1436 1437DEFHEADING(USB options:) 1438STEXI 1439@table @option 1440ETEXI 1441 1442DEF("usb", 0, QEMU_OPTION_usb, 1443 "-usb enable on-board USB host controller (if not enabled by default)\n", 1444 QEMU_ARCH_ALL) 1445STEXI 1446@item -usb 1447@findex -usb 1448Enable USB emulation on machine types with an on-board USB host controller (if 1449not enabled by default). Note that on-board USB host controllers may not 1450support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1451on machines with PCI. 1452ETEXI 1453 1454DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1455 "-usbdevice name add the host or guest USB device 'name'\n", 1456 QEMU_ARCH_ALL) 1457STEXI 1458 1459@item -usbdevice @var{devname} 1460@findex -usbdevice 1461Add the USB device @var{devname}. Note that this option is deprecated, 1462please use @code{-device usb-...} instead. @xref{usb_devices}. 1463 1464@table @option 1465 1466@item mouse 1467Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1468 1469@item tablet 1470Pointer device that uses absolute coordinates (like a touchscreen). This 1471means QEMU is able to report the mouse position without having to grab the 1472mouse. Also overrides the PS/2 mouse emulation when activated. 1473 1474@item braille 1475Braille device. This will use BrlAPI to display the braille output on a real 1476or fake device. 1477 1478@end table 1479ETEXI 1480 1481STEXI 1482@end table 1483ETEXI 1484DEFHEADING() 1485 1486DEFHEADING(Display options:) 1487STEXI 1488@table @option 1489ETEXI 1490 1491DEF("display", HAS_ARG, QEMU_OPTION_display, 1492 "-display spice-app[,gl=on|off]\n" 1493 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1494 " [,window_close=on|off][,gl=on|core|es|off]\n" 1495 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1496 "-display vnc=<display>[,<optargs>]\n" 1497 "-display curses[,charset=<encoding>]\n" 1498 "-display none\n" 1499 "-display egl-headless[,rendernode=<file>]" 1500 " select display type\n" 1501 "The default display is equivalent to\n" 1502#if defined(CONFIG_GTK) 1503 "\t\"-display gtk\"\n" 1504#elif defined(CONFIG_SDL) 1505 "\t\"-display sdl\"\n" 1506#elif defined(CONFIG_COCOA) 1507 "\t\"-display cocoa\"\n" 1508#elif defined(CONFIG_VNC) 1509 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1510#else 1511 "\t\"-display none\"\n" 1512#endif 1513 , QEMU_ARCH_ALL) 1514STEXI 1515@item -display @var{type} 1516@findex -display 1517Select type of display to use. This option is a replacement for the 1518old style -sdl/-curses/... options. Valid values for @var{type} are 1519@table @option 1520@item sdl 1521Display video output via SDL (usually in a separate graphics 1522window; see the SDL documentation for other possibilities). 1523@item curses 1524Display video output via curses. For graphics device models which 1525support a text mode, QEMU can display this output using a 1526curses/ncurses interface. Nothing is displayed when the graphics 1527device is in graphical mode or if the graphics device does not support 1528a text mode. Generally only the VGA device models support text mode. 1529The font charset used by the guest can be specified with the 1530@code{charset} option, for example @code{charset=CP850} for IBM CP850 1531encoding. The default is @code{CP437}. 1532@item none 1533Do not display video output. The guest will still see an emulated 1534graphics card, but its output will not be displayed to the QEMU 1535user. This option differs from the -nographic option in that it 1536only affects what is done with video output; -nographic also changes 1537the destination of the serial and parallel port data. 1538@item gtk 1539Display video output in a GTK window. This interface provides drop-down 1540menus and other UI elements to configure and control the VM during 1541runtime. 1542@item vnc 1543Start a VNC server on display <arg> 1544@item egl-headless 1545Offload all OpenGL operations to a local DRI device. For any graphical display, 1546this display needs to be paired with either VNC or SPICE displays. 1547@item spice-app 1548Start QEMU as a Spice server and launch the default Spice client 1549application. The Spice server will redirect the serial consoles and 1550QEMU monitors. (Since 4.0) 1551@end table 1552ETEXI 1553 1554DEF("nographic", 0, QEMU_OPTION_nographic, 1555 "-nographic disable graphical output and redirect serial I/Os to console\n", 1556 QEMU_ARCH_ALL) 1557STEXI 1558@item -nographic 1559@findex -nographic 1560Normally, if QEMU is compiled with graphical window support, it displays 1561output such as guest graphics, guest console, and the QEMU monitor in a 1562window. With this option, you can totally disable graphical output so 1563that QEMU is a simple command line application. The emulated serial port 1564is redirected on the console and muxed with the monitor (unless 1565redirected elsewhere explicitly). Therefore, you can still use QEMU to 1566debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1567switching between the console and monitor. 1568ETEXI 1569 1570DEF("curses", 0, QEMU_OPTION_curses, 1571 "-curses shorthand for -display curses\n", 1572 QEMU_ARCH_ALL) 1573STEXI 1574@item -curses 1575@findex -curses 1576Normally, if QEMU is compiled with graphical window support, it displays 1577output such as guest graphics, guest console, and the QEMU monitor in a 1578window. With this option, QEMU can display the VGA output when in text 1579mode using a curses/ncurses interface. Nothing is displayed in graphical 1580mode. 1581ETEXI 1582 1583DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1584 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1585 QEMU_ARCH_ALL) 1586STEXI 1587@item -alt-grab 1588@findex -alt-grab 1589Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1590affects the special keys (for fullscreen, monitor-mode switching, etc). 1591ETEXI 1592 1593DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1594 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1595 QEMU_ARCH_ALL) 1596STEXI 1597@item -ctrl-grab 1598@findex -ctrl-grab 1599Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1600affects the special keys (for fullscreen, monitor-mode switching, etc). 1601ETEXI 1602 1603DEF("no-quit", 0, QEMU_OPTION_no_quit, 1604 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1605STEXI 1606@item -no-quit 1607@findex -no-quit 1608Disable SDL window close capability. 1609ETEXI 1610 1611DEF("sdl", 0, QEMU_OPTION_sdl, 1612 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1613STEXI 1614@item -sdl 1615@findex -sdl 1616Enable SDL. 1617ETEXI 1618 1619DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1620 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1621 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1622 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1623 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1624 " [,tls-ciphers=<list>]\n" 1625 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1626 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1627 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1628 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1629 " [,jpeg-wan-compression=[auto|never|always]]\n" 1630 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1631 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1632 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1633 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1634 " [,gl=[on|off]][,rendernode=<file>]\n" 1635 " enable spice\n" 1636 " at least one of {port, tls-port} is mandatory\n", 1637 QEMU_ARCH_ALL) 1638STEXI 1639@item -spice @var{option}[,@var{option}[,...]] 1640@findex -spice 1641Enable the spice remote desktop protocol. Valid options are 1642 1643@table @option 1644 1645@item port=<nr> 1646Set the TCP port spice is listening on for plaintext channels. 1647 1648@item addr=<addr> 1649Set the IP address spice is listening on. Default is any address. 1650 1651@item ipv4 1652@itemx ipv6 1653@itemx unix 1654Force using the specified IP version. 1655 1656@item password=<secret> 1657Set the password you need to authenticate. 1658 1659@item sasl 1660Require that the client use SASL to authenticate with the spice. 1661The exact choice of authentication method used is controlled from the 1662system / user's SASL configuration file for the 'qemu' service. This 1663is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1664unprivileged user, an environment variable SASL_CONF_PATH can be used 1665to make it search alternate locations for the service config. 1666While some SASL auth methods can also provide data encryption (eg GSSAPI), 1667it is recommended that SASL always be combined with the 'tls' and 1668'x509' settings to enable use of SSL and server certificates. This 1669ensures a data encryption preventing compromise of authentication 1670credentials. 1671 1672@item disable-ticketing 1673Allow client connects without authentication. 1674 1675@item disable-copy-paste 1676Disable copy paste between the client and the guest. 1677 1678@item disable-agent-file-xfer 1679Disable spice-vdagent based file-xfer between the client and the guest. 1680 1681@item tls-port=<nr> 1682Set the TCP port spice is listening on for encrypted channels. 1683 1684@item x509-dir=<dir> 1685Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1686 1687@item x509-key-file=<file> 1688@itemx x509-key-password=<file> 1689@itemx x509-cert-file=<file> 1690@itemx x509-cacert-file=<file> 1691@itemx x509-dh-key-file=<file> 1692The x509 file names can also be configured individually. 1693 1694@item tls-ciphers=<list> 1695Specify which ciphers to use. 1696 1697@item tls-channel=[main|display|cursor|inputs|record|playback] 1698@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1699Force specific channel to be used with or without TLS encryption. The 1700options can be specified multiple times to configure multiple 1701channels. The special name "default" can be used to set the default 1702mode. For channels which are not explicitly forced into one mode the 1703spice client is allowed to pick tls/plaintext as he pleases. 1704 1705@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1706Configure image compression (lossless). 1707Default is auto_glz. 1708 1709@item jpeg-wan-compression=[auto|never|always] 1710@itemx zlib-glz-wan-compression=[auto|never|always] 1711Configure wan image compression (lossy for slow links). 1712Default is auto. 1713 1714@item streaming-video=[off|all|filter] 1715Configure video stream detection. Default is off. 1716 1717@item agent-mouse=[on|off] 1718Enable/disable passing mouse events via vdagent. Default is on. 1719 1720@item playback-compression=[on|off] 1721Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1722 1723@item seamless-migration=[on|off] 1724Enable/disable spice seamless migration. Default is off. 1725 1726@item gl=[on|off] 1727Enable/disable OpenGL context. Default is off. 1728 1729@item rendernode=<file> 1730DRM render node for OpenGL rendering. If not specified, it will pick 1731the first available. (Since 2.9) 1732 1733@end table 1734ETEXI 1735 1736DEF("portrait", 0, QEMU_OPTION_portrait, 1737 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1738 QEMU_ARCH_ALL) 1739STEXI 1740@item -portrait 1741@findex -portrait 1742Rotate graphical output 90 deg left (only PXA LCD). 1743ETEXI 1744 1745DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1746 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1747 QEMU_ARCH_ALL) 1748STEXI 1749@item -rotate @var{deg} 1750@findex -rotate 1751Rotate graphical output some deg left (only PXA LCD). 1752ETEXI 1753 1754DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1755 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1756 " select video card type\n", QEMU_ARCH_ALL) 1757STEXI 1758@item -vga @var{type} 1759@findex -vga 1760Select type of VGA card to emulate. Valid values for @var{type} are 1761@table @option 1762@item cirrus 1763Cirrus Logic GD5446 Video card. All Windows versions starting from 1764Windows 95 should recognize and use this graphic card. For optimal 1765performances, use 16 bit color depth in the guest and the host OS. 1766(This card was the default before QEMU 2.2) 1767@item std 1768Standard VGA card with Bochs VBE extensions. If your guest OS 1769supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1770to use high resolution modes (>= 1280x1024x16) then you should use 1771this option. (This card is the default since QEMU 2.2) 1772@item vmware 1773VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1774recent XFree86/XOrg server or Windows guest with a driver for this 1775card. 1776@item qxl 1777QXL paravirtual graphic card. It is VGA compatible (including VESA 17782.0 VBE support). Works best with qxl guest drivers installed though. 1779Recommended choice when using the spice protocol. 1780@item tcx 1781(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1782sun4m machines and offers both 8-bit and 24-bit colour depths at a 1783fixed resolution of 1024x768. 1784@item cg3 1785(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1786for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1787resolutions aimed at people wishing to run older Solaris versions. 1788@item virtio 1789Virtio VGA card. 1790@item none 1791Disable VGA card. 1792@end table 1793ETEXI 1794 1795DEF("full-screen", 0, QEMU_OPTION_full_screen, 1796 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1797STEXI 1798@item -full-screen 1799@findex -full-screen 1800Start in full screen. 1801ETEXI 1802 1803DEF("g", 1, QEMU_OPTION_g , 1804 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1805 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1806STEXI 1807@item -g @var{width}x@var{height}[x@var{depth}] 1808@findex -g 1809Set the initial graphical resolution and depth (PPC, SPARC only). 1810ETEXI 1811 1812DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1813 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1814STEXI 1815@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1816@findex -vnc 1817Normally, if QEMU is compiled with graphical window support, it displays 1818output such as guest graphics, guest console, and the QEMU monitor in a 1819window. With this option, you can have QEMU listen on VNC display 1820@var{display} and redirect the VGA display over the VNC session. It is 1821very useful to enable the usb tablet device when using this option 1822(option @option{-device usb-tablet}). When using the VNC display, you 1823must use the @option{-k} parameter to set the keyboard layout if you are 1824not using en-us. Valid syntax for the @var{display} is 1825 1826@table @option 1827 1828@item to=@var{L} 1829 1830With this option, QEMU will try next available VNC @var{display}s, until the 1831number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1832available, e.g. port 5900+@var{display} is already used by another 1833application. By default, to=0. 1834 1835@item @var{host}:@var{d} 1836 1837TCP connections will only be allowed from @var{host} on display @var{d}. 1838By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1839be omitted in which case the server will accept connections from any host. 1840 1841@item unix:@var{path} 1842 1843Connections will be allowed over UNIX domain sockets where @var{path} is the 1844location of a unix socket to listen for connections on. 1845 1846@item none 1847 1848VNC is initialized but not started. The monitor @code{change} command 1849can be used to later start the VNC server. 1850 1851@end table 1852 1853Following the @var{display} value there may be one or more @var{option} flags 1854separated by commas. Valid options are 1855 1856@table @option 1857 1858@item reverse 1859 1860Connect to a listening VNC client via a ``reverse'' connection. The 1861client is specified by the @var{display}. For reverse network 1862connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1863is a TCP port number, not a display number. 1864 1865@item websocket 1866 1867Opens an additional TCP listening port dedicated to VNC Websocket connections. 1868If a bare @var{websocket} option is given, the Websocket port is 18695700+@var{display}. An alternative port can be specified with the 1870syntax @code{websocket}=@var{port}. 1871 1872If @var{host} is specified connections will only be allowed from this host. 1873It is possible to control the websocket listen address independently, using 1874the syntax @code{websocket}=@var{host}:@var{port}. 1875 1876If no TLS credentials are provided, the websocket connection runs in 1877unencrypted mode. If TLS credentials are provided, the websocket connection 1878requires encrypted client connections. 1879 1880@item password 1881 1882Require that password based authentication is used for client connections. 1883 1884The password must be set separately using the @code{set_password} command in 1885the @ref{pcsys_monitor}. The syntax to change your password is: 1886@code{set_password <protocol> <password>} where <protocol> could be either 1887"vnc" or "spice". 1888 1889If you would like to change <protocol> password expiration, you should use 1890@code{expire_password <protocol> <expiration-time>} where expiration time could 1891be one of the following options: now, never, +seconds or UNIX time of 1892expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1893to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1894date and time). 1895 1896You can also use keywords "now" or "never" for the expiration time to 1897allow <protocol> password to expire immediately or never expire. 1898 1899@item tls-creds=@var{ID} 1900 1901Provides the ID of a set of TLS credentials to use to secure the 1902VNC server. They will apply to both the normal VNC server socket 1903and the websocket socket (if enabled). Setting TLS credentials 1904will cause the VNC server socket to enable the VeNCrypt auth 1905mechanism. The credentials should have been previously created 1906using the @option{-object tls-creds} argument. 1907 1908@item tls-authz=@var{ID} 1909 1910Provides the ID of the QAuthZ authorization object against which 1911the client's x509 distinguished name will validated. This object is 1912only resolved at time of use, so can be deleted and recreated on the 1913fly while the VNC server is active. If missing, it will default 1914to denying access. 1915 1916@item sasl 1917 1918Require that the client use SASL to authenticate with the VNC server. 1919The exact choice of authentication method used is controlled from the 1920system / user's SASL configuration file for the 'qemu' service. This 1921is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1922unprivileged user, an environment variable SASL_CONF_PATH can be used 1923to make it search alternate locations for the service config. 1924While some SASL auth methods can also provide data encryption (eg GSSAPI), 1925it is recommended that SASL always be combined with the 'tls' and 1926'x509' settings to enable use of SSL and server certificates. This 1927ensures a data encryption preventing compromise of authentication 1928credentials. See the @ref{vnc_security} section for details on using 1929SASL authentication. 1930 1931@item sasl-authz=@var{ID} 1932 1933Provides the ID of the QAuthZ authorization object against which 1934the client's SASL username will validated. This object is 1935only resolved at time of use, so can be deleted and recreated on the 1936fly while the VNC server is active. If missing, it will default 1937to denying access. 1938 1939@item acl 1940 1941Legacy method for enabling authorization of clients against the 1942x509 distinguished name and SASL username. It results in the creation 1943of two @code{authz-list} objects with IDs of @code{vnc.username} and 1944@code{vnc.x509dname}. The rules for these objects must be configured 1945with the HMP ACL commands. 1946 1947This option is deprecated and should no longer be used. The new 1948@option{sasl-authz} and @option{tls-authz} options are a 1949replacement. 1950 1951@item lossy 1952 1953Enable lossy compression methods (gradient, JPEG, ...). If this 1954option is set, VNC client may receive lossy framebuffer updates 1955depending on its encoding settings. Enabling this option can save 1956a lot of bandwidth at the expense of quality. 1957 1958@item non-adaptive 1959 1960Disable adaptive encodings. Adaptive encodings are enabled by default. 1961An adaptive encoding will try to detect frequently updated screen regions, 1962and send updates in these regions using a lossy encoding (like JPEG). 1963This can be really helpful to save bandwidth when playing videos. Disabling 1964adaptive encodings restores the original static behavior of encodings 1965like Tight. 1966 1967@item share=[allow-exclusive|force-shared|ignore] 1968 1969Set display sharing policy. 'allow-exclusive' allows clients to ask 1970for exclusive access. As suggested by the rfb spec this is 1971implemented by dropping other connections. Connecting multiple 1972clients in parallel requires all clients asking for a shared session 1973(vncviewer: -shared switch). This is the default. 'force-shared' 1974disables exclusive client access. Useful for shared desktop sessions, 1975where you don't want someone forgetting specify -shared disconnect 1976everybody else. 'ignore' completely ignores the shared flag and 1977allows everybody connect unconditionally. Doesn't conform to the rfb 1978spec but is traditional QEMU behavior. 1979 1980@item key-delay-ms 1981 1982Set keyboard delay, for key down and key up events, in milliseconds. 1983Default is 10. Keyboards are low-bandwidth devices, so this slowdown 1984can help the device and guest to keep up and not lose events in case 1985events are arriving in bulk. Possible causes for the latter are flaky 1986network connections, or scripts for automated testing. 1987 1988@item audiodev=@var{audiodev} 1989 1990Use the specified @var{audiodev} when the VNC client requests audio 1991transmission. When not using an -audiodev argument, this option must 1992be omitted, otherwise is must be present and specify a valid audiodev. 1993 1994@end table 1995ETEXI 1996 1997STEXI 1998@end table 1999ETEXI 2000ARCHHEADING(, QEMU_ARCH_I386) 2001 2002ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2003STEXI 2004@table @option 2005ETEXI 2006 2007DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2008 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2009 QEMU_ARCH_I386) 2010STEXI 2011@item -win2k-hack 2012@findex -win2k-hack 2013Use it when installing Windows 2000 to avoid a disk full bug. After 2014Windows 2000 is installed, you no longer need this option (this option 2015slows down the IDE transfers). 2016ETEXI 2017 2018DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2019 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2020 QEMU_ARCH_I386) 2021STEXI 2022@item -no-fd-bootchk 2023@findex -no-fd-bootchk 2024Disable boot signature checking for floppy disks in BIOS. May 2025be needed to boot from old floppy disks. 2026ETEXI 2027 2028DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2029 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2030STEXI 2031@item -no-acpi 2032@findex -no-acpi 2033Disable ACPI (Advanced Configuration and Power Interface) support. Use 2034it if your guest OS complains about ACPI problems (PC target machine 2035only). 2036ETEXI 2037 2038DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2039 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2040STEXI 2041@item -no-hpet 2042@findex -no-hpet 2043Disable HPET support. 2044ETEXI 2045 2046DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2047 "-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" 2048 " ACPI table description\n", QEMU_ARCH_I386) 2049STEXI 2050@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}]...] 2051@findex -acpitable 2052Add ACPI table with specified header fields and context from specified files. 2053For file=, take whole ACPI table from the specified files, including all 2054ACPI headers (possible overridden by other options). 2055For data=, only data 2056portion of the table is used, all header information is specified in the 2057command line. 2058If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2059fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2060to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2061spec. 2062ETEXI 2063 2064DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2065 "-smbios file=binary\n" 2066 " load SMBIOS entry from binary file\n" 2067 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2068 " [,uefi=on|off]\n" 2069 " specify SMBIOS type 0 fields\n" 2070 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2071 " [,uuid=uuid][,sku=str][,family=str]\n" 2072 " specify SMBIOS type 1 fields\n" 2073 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2074 " [,asset=str][,location=str]\n" 2075 " specify SMBIOS type 2 fields\n" 2076 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2077 " [,sku=str]\n" 2078 " specify SMBIOS type 3 fields\n" 2079 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2080 " [,asset=str][,part=str]\n" 2081 " specify SMBIOS type 4 fields\n" 2082 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2083 " [,asset=str][,part=str][,speed=%d]\n" 2084 " specify SMBIOS type 17 fields\n", 2085 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2086STEXI 2087@item -smbios file=@var{binary} 2088@findex -smbios 2089Load SMBIOS entry from binary file. 2090 2091@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2092Specify SMBIOS type 0 fields 2093 2094@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}] 2095Specify SMBIOS type 1 fields 2096 2097@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2098Specify SMBIOS type 2 fields 2099 2100@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2101Specify SMBIOS type 3 fields 2102 2103@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2104Specify SMBIOS type 4 fields 2105 2106@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}] 2107Specify SMBIOS type 17 fields 2108ETEXI 2109 2110STEXI 2111@end table 2112ETEXI 2113DEFHEADING() 2114 2115DEFHEADING(Network options:) 2116STEXI 2117@table @option 2118ETEXI 2119 2120DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2121#ifdef CONFIG_SLIRP 2122 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2123 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2124 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2125 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2126 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2127#ifndef _WIN32 2128 "[,smb=dir[,smbserver=addr]]\n" 2129#endif 2130 " configure a user mode network backend with ID 'str',\n" 2131 " its DHCP server and optional services\n" 2132#endif 2133#ifdef _WIN32 2134 "-netdev tap,id=str,ifname=name\n" 2135 " configure a host TAP network backend with ID 'str'\n" 2136#else 2137 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2138 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2139 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2140 " [,poll-us=n]\n" 2141 " configure a host TAP network backend with ID 'str'\n" 2142 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2143 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2144 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2145 " to deconfigure it\n" 2146 " use '[down]script=no' to disable script execution\n" 2147 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2148 " configure it\n" 2149 " use 'fd=h' to connect to an already opened TAP interface\n" 2150 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2151 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2152 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2153 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2154 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2155 " use vhost=on to enable experimental in kernel accelerator\n" 2156 " (only has effect for virtio guests which use MSIX)\n" 2157 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2158 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2159 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2160 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2161 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2162 " spent on busy polling for vhost net\n" 2163 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2164 " configure a host TAP network backend with ID 'str' that is\n" 2165 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2166 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2167#endif 2168#ifdef __linux__ 2169 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2170 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2171 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2172 " [,rxcookie=rxcookie][,offset=offset]\n" 2173 " configure a network backend with ID 'str' connected to\n" 2174 " an Ethernet over L2TPv3 pseudowire.\n" 2175 " Linux kernel 3.3+ as well as most routers can talk\n" 2176 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2177 " VM to a router and even VM to Host. It is a nearly-universal\n" 2178 " standard (RFC3391). Note - this implementation uses static\n" 2179 " pre-configured tunnels (same as the Linux kernel).\n" 2180 " use 'src=' to specify source address\n" 2181 " use 'dst=' to specify destination address\n" 2182 " use 'udp=on' to specify udp encapsulation\n" 2183 " use 'srcport=' to specify source udp port\n" 2184 " use 'dstport=' to specify destination udp port\n" 2185 " use 'ipv6=on' to force v6\n" 2186 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2187 " well as a weak security measure\n" 2188 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2189 " use 'txcookie=0x012345678' to specify a txcookie\n" 2190 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2191 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2192 " use 'pincounter=on' to work around broken counter handling in peer\n" 2193 " use 'offset=X' to add an extra offset between header and data\n" 2194#endif 2195 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2196 " configure a network backend to connect to another network\n" 2197 " using a socket connection\n" 2198 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2199 " configure a network backend to connect to a multicast maddr and port\n" 2200 " use 'localaddr=addr' to specify the host address to send packets from\n" 2201 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2202 " configure a network backend to connect to another network\n" 2203 " using an UDP tunnel\n" 2204#ifdef CONFIG_VDE 2205 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2206 " configure a network backend to connect to port 'n' of a vde switch\n" 2207 " running on host and listening for incoming connections on 'socketpath'.\n" 2208 " Use group 'groupname' and mode 'octalmode' to change default\n" 2209 " ownership and permissions for communication port.\n" 2210#endif 2211#ifdef CONFIG_NETMAP 2212 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2213 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2214 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2215 " netmap device, defaults to '/dev/netmap')\n" 2216#endif 2217#ifdef CONFIG_POSIX 2218 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2219 " configure a vhost-user network, backed by a chardev 'dev'\n" 2220#endif 2221 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2222 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2223DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2224 "-nic [tap|bridge|" 2225#ifdef CONFIG_SLIRP 2226 "user|" 2227#endif 2228#ifdef __linux__ 2229 "l2tpv3|" 2230#endif 2231#ifdef CONFIG_VDE 2232 "vde|" 2233#endif 2234#ifdef CONFIG_NETMAP 2235 "netmap|" 2236#endif 2237#ifdef CONFIG_POSIX 2238 "vhost-user|" 2239#endif 2240 "socket][,option][,...][mac=macaddr]\n" 2241 " initialize an on-board / default host NIC (using MAC address\n" 2242 " macaddr) and connect it to the given host network backend\n" 2243 "-nic none use it alone to have zero network devices (the default is to\n" 2244 " provided a 'user' network connection)\n", 2245 QEMU_ARCH_ALL) 2246DEF("net", HAS_ARG, QEMU_OPTION_net, 2247 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2248 " configure or create an on-board (or machine default) NIC and\n" 2249 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2250 "-net [" 2251#ifdef CONFIG_SLIRP 2252 "user|" 2253#endif 2254 "tap|" 2255 "bridge|" 2256#ifdef CONFIG_VDE 2257 "vde|" 2258#endif 2259#ifdef CONFIG_NETMAP 2260 "netmap|" 2261#endif 2262 "socket][,option][,option][,...]\n" 2263 " old way to initialize a host network interface\n" 2264 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2265STEXI 2266@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2267@findex -nic 2268This option is a shortcut for configuring both the on-board (default) guest 2269NIC hardware and the host network backend in one go. The host backend options 2270are the same as with the corresponding @option{-netdev} options below. 2271The guest NIC model can be set with @option{model=@var{modelname}}. 2272Use @option{model=help} to list the available device types. 2273The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2274 2275The following two example do exactly the same, to show how @option{-nic} can 2276be used to shorten the command line length (note that the e1000 is the default 2277on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2278@example 2279@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2280@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2281@end example 2282 2283@item -nic none 2284Indicate that no network devices should be configured. It is used to override 2285the default configuration (default NIC with ``user'' host network backend) 2286which is activated if no other networking options are provided. 2287 2288@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2289@findex -netdev 2290Configure user mode host network backend which requires no administrator 2291privilege to run. Valid options are: 2292 2293@table @option 2294@item id=@var{id} 2295Assign symbolic name for use in monitor commands. 2296 2297@item ipv4=on|off and ipv6=on|off 2298Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2299both protocols are enabled. 2300 2301@item net=@var{addr}[/@var{mask}] 2302Set IP network address the guest will see. Optionally specify the netmask, 2303either in the form a.b.c.d or as number of valid top-most bits. Default is 230410.0.2.0/24. 2305 2306@item host=@var{addr} 2307Specify the guest-visible address of the host. Default is the 2nd IP in the 2308guest network, i.e. x.x.x.2. 2309 2310@item ipv6-net=@var{addr}[/@var{int}] 2311Set IPv6 network address the guest will see (default is fec0::/64). The 2312network prefix is given in the usual hexadecimal IPv6 address 2313notation. The prefix size is optional, and is given as the number of 2314valid top-most bits (default is 64). 2315 2316@item ipv6-host=@var{addr} 2317Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2318the guest network, i.e. xxxx::2. 2319 2320@item restrict=on|off 2321If this option is enabled, the guest will be isolated, i.e. it will not be 2322able to contact the host and no guest IP packets will be routed over the host 2323to the outside. This option does not affect any explicitly set forwarding rules. 2324 2325@item hostname=@var{name} 2326Specifies the client hostname reported by the built-in DHCP server. 2327 2328@item dhcpstart=@var{addr} 2329Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2330is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2331 2332@item dns=@var{addr} 2333Specify the guest-visible address of the virtual nameserver. The address must 2334be different from the host address. Default is the 3rd IP in the guest network, 2335i.e. x.x.x.3. 2336 2337@item ipv6-dns=@var{addr} 2338Specify the guest-visible address of the IPv6 virtual nameserver. The address 2339must be different from the host address. Default is the 3rd IP in the guest 2340network, i.e. xxxx::3. 2341 2342@item dnssearch=@var{domain} 2343Provides an entry for the domain-search list sent by the built-in 2344DHCP server. More than one domain suffix can be transmitted by specifying 2345this option multiple times. If supported, this will cause the guest to 2346automatically try to append the given domain suffix(es) in case a domain name 2347can not be resolved. 2348 2349Example: 2350@example 2351@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2352@end example 2353 2354@item domainname=@var{domain} 2355Specifies the client domain name reported by the built-in DHCP server. 2356 2357@item tftp=@var{dir} 2358When using the user mode network stack, activate a built-in TFTP 2359server. The files in @var{dir} will be exposed as the root of a TFTP server. 2360The TFTP client on the guest must be configured in binary mode (use the command 2361@code{bin} of the Unix TFTP client). 2362 2363@item tftp-server-name=@var{name} 2364In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 236566). This can be used to advise the guest to load boot files or configurations 2366from a different server than the host address. 2367 2368@item bootfile=@var{file} 2369When using the user mode network stack, broadcast @var{file} as the BOOTP 2370filename. In conjunction with @option{tftp}, this can be used to network boot 2371a guest from a local directory. 2372 2373Example (using pxelinux): 2374@example 2375@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2376 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2377@end example 2378 2379@item smb=@var{dir}[,smbserver=@var{addr}] 2380When using the user mode network stack, activate a built-in SMB 2381server so that Windows OSes can access to the host files in @file{@var{dir}} 2382transparently. The IP address of the SMB server can be set to @var{addr}. By 2383default the 4th IP in the guest network is used, i.e. x.x.x.4. 2384 2385In the guest Windows OS, the line: 2386@example 238710.0.2.4 smbserver 2388@end example 2389must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2390or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2391 2392Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2393 2394Note that a SAMBA server must be installed on the host OS. 2395 2396@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2397Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2398the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2399@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2400given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2401be bound to a specific host interface. If no connection type is set, TCP is 2402used. This option can be given multiple times. 2403 2404For example, to redirect host X11 connection from screen 1 to guest 2405screen 0, use the following: 2406 2407@example 2408# on the host 2409@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2410# this host xterm should open in the guest X11 server 2411xterm -display :1 2412@end example 2413 2414To redirect telnet connections from host port 5555 to telnet port on 2415the guest, use the following: 2416 2417@example 2418# on the host 2419@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2420telnet localhost 5555 2421@end example 2422 2423Then when you use on the host @code{telnet localhost 5555}, you 2424connect to the guest telnet server. 2425 2426@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2427@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2428Forward guest TCP connections to the IP address @var{server} on port @var{port} 2429to the character device @var{dev} or to a program executed by @var{cmd:command} 2430which gets spawned for each connection. This option can be given multiple times. 2431 2432You can either use a chardev directly and have that one used throughout QEMU's 2433lifetime, like in the following example: 2434 2435@example 2436# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2437# the guest accesses it 2438@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2439@end example 2440 2441Or you can execute a command on every TCP connection established by the guest, 2442so that QEMU behaves similar to an inetd process for that virtual server: 2443 2444@example 2445# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2446# and connect the TCP stream to its stdin/stdout 2447@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2448@end example 2449 2450@end table 2451 2452@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2453Configure a host TAP network backend with ID @var{id}. 2454 2455Use the network script @var{file} to configure it and the network script 2456@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2457automatically provides one. The default network configure script is 2458@file{/etc/qemu-ifup} and the default network deconfigure script is 2459@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2460to disable script execution. 2461 2462If running QEMU as an unprivileged user, use the network helper 2463@var{helper} to configure the TAP interface and attach it to the bridge. 2464The default network helper executable is @file{/path/to/qemu-bridge-helper} 2465and the default bridge device is @file{br0}. 2466 2467@option{fd}=@var{h} can be used to specify the handle of an already 2468opened host TAP interface. 2469 2470Examples: 2471 2472@example 2473#launch a QEMU instance with the default network script 2474@value{qemu_system} linux.img -nic tap 2475@end example 2476 2477@example 2478#launch a QEMU instance with two NICs, each one connected 2479#to a TAP device 2480@value{qemu_system} linux.img \ 2481 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2482 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2483@end example 2484 2485@example 2486#launch a QEMU instance with the default network helper to 2487#connect a TAP device to bridge br0 2488@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2489 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2490@end example 2491 2492@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2493Connect a host TAP network interface to a host bridge device. 2494 2495Use the network helper @var{helper} to configure the TAP interface and 2496attach it to the bridge. The default network helper executable is 2497@file{/path/to/qemu-bridge-helper} and the default bridge 2498device is @file{br0}. 2499 2500Examples: 2501 2502@example 2503#launch a QEMU instance with the default network helper to 2504#connect a TAP device to bridge br0 2505@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2506@end example 2507 2508@example 2509#launch a QEMU instance with the default network helper to 2510#connect a TAP device to bridge qemubr0 2511@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2512@end example 2513 2514@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2515 2516This host network backend can be used to connect the guest's network to 2517another QEMU virtual machine using a TCP socket connection. If @option{listen} 2518is specified, QEMU waits for incoming connections on @var{port} 2519(@var{host} is optional). @option{connect} is used to connect to 2520another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2521specifies an already opened TCP socket. 2522 2523Example: 2524@example 2525# launch a first QEMU instance 2526@value{qemu_system} linux.img \ 2527 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2528 -netdev socket,id=n1,listen=:1234 2529# connect the network of this instance to the network of the first instance 2530@value{qemu_system} linux.img \ 2531 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2532 -netdev socket,id=n2,connect=127.0.0.1:1234 2533@end example 2534 2535@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2536 2537Configure a socket host network backend to share the guest's network traffic 2538with another QEMU virtual machines using a UDP multicast socket, effectively 2539making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2540NOTES: 2541@enumerate 2542@item 2543Several QEMU can be running on different hosts and share same bus (assuming 2544correct multicast setup for these hosts). 2545@item 2546mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2547@url{http://user-mode-linux.sf.net}. 2548@item 2549Use @option{fd=h} to specify an already opened UDP multicast socket. 2550@end enumerate 2551 2552Example: 2553@example 2554# launch one QEMU instance 2555@value{qemu_system} linux.img \ 2556 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2557 -netdev socket,id=n1,mcast=230.0.0.1:1234 2558# launch another QEMU instance on same "bus" 2559@value{qemu_system} linux.img \ 2560 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2561 -netdev socket,id=n2,mcast=230.0.0.1:1234 2562# launch yet another QEMU instance on same "bus" 2563@value{qemu_system} linux.img \ 2564 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2565 -netdev socket,id=n3,mcast=230.0.0.1:1234 2566@end example 2567 2568Example (User Mode Linux compat.): 2569@example 2570# launch QEMU instance (note mcast address selected is UML's default) 2571@value{qemu_system} linux.img \ 2572 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2573 -netdev socket,id=n1,mcast=239.192.168.1:1102 2574# launch UML 2575/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2576@end example 2577 2578Example (send packets from host's 1.2.3.4): 2579@example 2580@value{qemu_system} linux.img \ 2581 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2582 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2583@end example 2584 2585@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}] 2586Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2587popular protocol to transport Ethernet (and other Layer 2) data frames between 2588two systems. It is present in routers, firewalls and the Linux kernel 2589(from version 3.3 onwards). 2590 2591This transport allows a VM to communicate to another VM, router or firewall directly. 2592 2593@table @option 2594@item src=@var{srcaddr} 2595 source address (mandatory) 2596@item dst=@var{dstaddr} 2597 destination address (mandatory) 2598@item udp 2599 select udp encapsulation (default is ip). 2600@item srcport=@var{srcport} 2601 source udp port. 2602@item dstport=@var{dstport} 2603 destination udp port. 2604@item ipv6 2605 force v6, otherwise defaults to v4. 2606@item rxcookie=@var{rxcookie} 2607@itemx txcookie=@var{txcookie} 2608 Cookies are a weak form of security in the l2tpv3 specification. 2609Their function is mostly to prevent misconfiguration. By default they are 32 2610bit. 2611@item cookie64 2612 Set cookie size to 64 bit instead of the default 32 2613@item counter=off 2614 Force a 'cut-down' L2TPv3 with no counter as in 2615draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2616@item pincounter=on 2617 Work around broken counter handling in peer. This may also help on 2618networks which have packet reorder. 2619@item offset=@var{offset} 2620 Add an extra offset between header and data 2621@end table 2622 2623For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2624on the remote Linux host 1.2.3.4: 2625@example 2626# Setup tunnel on linux host using raw ip as encapsulation 2627# on 1.2.3.4 2628ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2629 encap udp udp_sport 16384 udp_dport 16384 2630ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2631 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2632ifconfig vmtunnel0 mtu 1500 2633ifconfig vmtunnel0 up 2634brctl addif br-lan vmtunnel0 2635 2636 2637# on 4.3.2.1 2638# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2639 2640@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2641 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2642 2643@end example 2644 2645@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2646Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2647listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2648and MODE @var{octalmode} to change default ownership and permissions for 2649communication port. This option is only available if QEMU has been compiled 2650with vde support enabled. 2651 2652Example: 2653@example 2654# launch vde switch 2655vde_switch -F -sock /tmp/myswitch 2656# launch QEMU instance 2657@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2658@end example 2659 2660@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2661 2662Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2663be a unix domain socket backed one. The vhost-user uses a specifically defined 2664protocol to pass vhost ioctl replacement messages to an application on the other 2665end of the socket. On non-MSIX guests, the feature can be forced with 2666@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2667be created for multiqueue vhost-user. 2668 2669Example: 2670@example 2671qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2672 -numa node,memdev=mem \ 2673 -chardev socket,id=chr0,path=/path/to/socket \ 2674 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2675 -device virtio-net-pci,netdev=net0 2676@end example 2677 2678@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2679 2680Create a hub port on the emulated hub with ID @var{hubid}. 2681 2682The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2683single netdev. Alternatively, you can also connect the hubport to another 2684netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2685 2686@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2687@findex -net 2688Legacy option to configure or create an on-board (or machine default) Network 2689Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2690the default hub), or to the netdev @var{nd}. 2691The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2692can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2693only), and a @var{name} can be assigned for use in monitor commands. 2694Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2695that the card should have; this option currently only affects virtio cards; set 2696@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2697NIC is created. QEMU can emulate several different models of network card. 2698Use @code{-net nic,model=help} for a list of available devices for your target. 2699 2700@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2701Configure a host network backend (with the options corresponding to the same 2702@option{-netdev} option) and connect it to the emulated hub 0 (the default 2703hub). Use @var{name} to specify the name of the hub port. 2704ETEXI 2705 2706STEXI 2707@end table 2708ETEXI 2709DEFHEADING() 2710 2711DEFHEADING(Character device options:) 2712 2713DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2714 "-chardev help\n" 2715 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2716 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2717 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2718 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2719 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2720 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2721 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2722 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2723 " [,logfile=PATH][,logappend=on|off]\n" 2724 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2725 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2726 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2727 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2728 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2729 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2730#ifdef _WIN32 2731 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2732 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2733#else 2734 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2735 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2736#endif 2737#ifdef CONFIG_BRLAPI 2738 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2739#endif 2740#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2741 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2742 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2743 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2744#endif 2745#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2746 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2747 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2748#endif 2749#if defined(CONFIG_SPICE) 2750 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2751 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2752#endif 2753 , QEMU_ARCH_ALL 2754) 2755 2756STEXI 2757 2758The general form of a character device option is: 2759@table @option 2760@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2761@findex -chardev 2762Backend is one of: 2763@option{null}, 2764@option{socket}, 2765@option{udp}, 2766@option{msmouse}, 2767@option{vc}, 2768@option{ringbuf}, 2769@option{file}, 2770@option{pipe}, 2771@option{console}, 2772@option{serial}, 2773@option{pty}, 2774@option{stdio}, 2775@option{braille}, 2776@option{tty}, 2777@option{parallel}, 2778@option{parport}, 2779@option{spicevmc}, 2780@option{spiceport}. 2781The specific backend will determine the applicable options. 2782 2783Use @code{-chardev help} to print all available chardev backend types. 2784 2785All devices must have an id, which can be any string up to 127 characters long. 2786It is used to uniquely identify this device in other command line directives. 2787 2788A character device may be used in multiplexing mode by multiple front-ends. 2789Specify @option{mux=on} to enable this mode. 2790A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2791backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2792If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2793create a multiplexer with your specified ID, and you can then configure multiple 2794front ends to use that chardev ID for their input/output. Up to four different 2795front ends can be connected to a single multiplexed chardev. (Without 2796multiplexing enabled, a chardev can only be used by a single front end.) 2797For instance you could use this to allow a single stdio chardev to be used by 2798two serial ports and the QEMU monitor: 2799 2800@example 2801-chardev stdio,mux=on,id=char0 \ 2802-mon chardev=char0,mode=readline \ 2803-serial chardev:char0 \ 2804-serial chardev:char0 2805@end example 2806 2807You can have more than one multiplexer in a system configuration; for instance 2808you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2809multiplexed between the QEMU monitor and a parallel port: 2810 2811@example 2812-chardev stdio,mux=on,id=char0 \ 2813-mon chardev=char0,mode=readline \ 2814-parallel chardev:char0 \ 2815-chardev tcp,...,mux=on,id=char1 \ 2816-serial chardev:char1 \ 2817-serial chardev:char1 2818@end example 2819 2820When you're using a multiplexed character device, some escape sequences are 2821interpreted in the input. @xref{mux_keys, Keys in the character backend 2822multiplexer}. 2823 2824Note that some other command line options may implicitly create multiplexed 2825character backends; for instance @option{-serial mon:stdio} creates a 2826multiplexed stdio backend connected to the serial port and the QEMU monitor, 2827and @option{-nographic} also multiplexes the console and the monitor to 2828stdio. 2829 2830There is currently no support for multiplexing in the other direction 2831(where a single QEMU front end takes input and output from multiple chardevs). 2832 2833Every backend supports the @option{logfile} option, which supplies the path 2834to a file to record all data transmitted via the backend. The @option{logappend} 2835option controls whether the log file will be truncated or appended to when 2836opened. 2837 2838@end table 2839 2840The available backends are: 2841 2842@table @option 2843@item -chardev null,id=@var{id} 2844A void device. This device will not emit any data, and will drop any data it 2845receives. The null backend does not take any options. 2846 2847@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}] 2848 2849Create a two-way stream socket, which can be either a TCP or a unix socket. A 2850unix socket will be created if @option{path} is specified. Behaviour is 2851undefined if TCP options are specified for a unix socket. 2852 2853@option{server} specifies that the socket shall be a listening socket. 2854 2855@option{nowait} specifies that QEMU should not block waiting for a client to 2856connect to a listening socket. 2857 2858@option{telnet} specifies that traffic on the socket should interpret telnet 2859escape sequences. 2860 2861@option{websocket} specifies that the socket uses WebSocket protocol for 2862communication. 2863 2864@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2865the remote end goes away. qemu will delay this many seconds and then attempt 2866to reconnect. Zero disables reconnecting, and is the default. 2867 2868@option{tls-creds} requests enablement of the TLS protocol for encryption, 2869and specifies the id of the TLS credentials to use for the handshake. The 2870credentials must be previously created with the @option{-object tls-creds} 2871argument. 2872 2873@option{tls-auth} provides the ID of the QAuthZ authorization object against 2874which the client's x509 distinguished name will be validated. This object is 2875only resolved at time of use, so can be deleted and recreated on the fly 2876while the chardev server is active. If missing, it will default to denying 2877access. 2878 2879TCP and unix socket options are given below: 2880 2881@table @option 2882 2883@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2884 2885@option{host} for a listening socket specifies the local address to be bound. 2886For a connecting socket species the remote host to connect to. @option{host} is 2887optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2888 2889@option{port} for a listening socket specifies the local port to be bound. For a 2890connecting socket specifies the port on the remote host to connect to. 2891@option{port} can be given as either a port number or a service name. 2892@option{port} is required. 2893 2894@option{to} is only relevant to listening sockets. If it is specified, and 2895@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2896to and including @option{to} until it succeeds. @option{to} must be specified 2897as a port number. 2898 2899@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2900If neither is specified the socket may use either protocol. 2901 2902@option{nodelay} disables the Nagle algorithm. 2903 2904@item unix options: path=@var{path} 2905 2906@option{path} specifies the local path of the unix socket. @option{path} is 2907required. 2908 2909@end table 2910 2911@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2912 2913Sends all traffic from the guest to a remote host over UDP. 2914 2915@option{host} specifies the remote host to connect to. If not specified it 2916defaults to @code{localhost}. 2917 2918@option{port} specifies the port on the remote host to connect to. @option{port} 2919is required. 2920 2921@option{localaddr} specifies the local address to bind to. If not specified it 2922defaults to @code{0.0.0.0}. 2923 2924@option{localport} specifies the local port to bind to. If not specified any 2925available local port will be used. 2926 2927@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2928If neither is specified the device may use either protocol. 2929 2930@item -chardev msmouse,id=@var{id} 2931 2932Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2933take any options. 2934 2935@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 2936 2937Connect to a QEMU text console. @option{vc} may optionally be given a specific 2938size. 2939 2940@option{width} and @option{height} specify the width and height respectively of 2941the console, in pixels. 2942 2943@option{cols} and @option{rows} specify that the console be sized to fit a text 2944console with the given dimensions. 2945 2946@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 2947 2948Create a ring buffer with fixed size @option{size}. 2949@var{size} must be a power of two and defaults to @code{64K}. 2950 2951@item -chardev file,id=@var{id},path=@var{path} 2952 2953Log all traffic received from the guest to a file. 2954 2955@option{path} specifies the path of the file to be opened. This file will be 2956created if it does not already exist, and overwritten if it does. @option{path} 2957is required. 2958 2959@item -chardev pipe,id=@var{id},path=@var{path} 2960 2961Create a two-way connection to the guest. The behaviour differs slightly between 2962Windows hosts and other hosts: 2963 2964On Windows, a single duplex pipe will be created at 2965@file{\\.pipe\@option{path}}. 2966 2967On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2968@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2969received by the guest. Data written by the guest can be read from 2970@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2971be present. 2972 2973@option{path} forms part of the pipe path as described above. @option{path} is 2974required. 2975 2976@item -chardev console,id=@var{id} 2977 2978Send traffic from the guest to QEMU's standard output. @option{console} does not 2979take any options. 2980 2981@option{console} is only available on Windows hosts. 2982 2983@item -chardev serial,id=@var{id},path=@option{path} 2984 2985Send traffic from the guest to a serial device on the host. 2986 2987On Unix hosts serial will actually accept any tty device, 2988not only serial lines. 2989 2990@option{path} specifies the name of the serial device to open. 2991 2992@item -chardev pty,id=@var{id} 2993 2994Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2995not take any options. 2996 2997@option{pty} is not available on Windows hosts. 2998 2999@item -chardev stdio,id=@var{id}[,signal=on|off] 3000Connect to standard input and standard output of the QEMU process. 3001 3002@option{signal} controls if signals are enabled on the terminal, that includes 3003exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3004default, use @option{signal=off} to disable it. 3005 3006@item -chardev braille,id=@var{id} 3007 3008Connect to a local BrlAPI server. @option{braille} does not take any options. 3009 3010@item -chardev tty,id=@var{id},path=@var{path} 3011 3012@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3013DragonFlyBSD hosts. It is an alias for @option{serial}. 3014 3015@option{path} specifies the path to the tty. @option{path} is required. 3016 3017@item -chardev parallel,id=@var{id},path=@var{path} 3018@itemx -chardev parport,id=@var{id},path=@var{path} 3019 3020@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3021 3022Connect to a local parallel port. 3023 3024@option{path} specifies the path to the parallel port device. @option{path} is 3025required. 3026 3027@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3028 3029@option{spicevmc} is only available when spice support is built in. 3030 3031@option{debug} debug level for spicevmc 3032 3033@option{name} name of spice channel to connect to 3034 3035Connect to a spice virtual machine channel, such as vdiport. 3036 3037@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3038 3039@option{spiceport} is only available when spice support is built in. 3040 3041@option{debug} debug level for spicevmc 3042 3043@option{name} name of spice port to connect to 3044 3045Connect to a spice port, allowing a Spice client to handle the traffic 3046identified by a name (preferably a fqdn). 3047ETEXI 3048 3049STEXI 3050@end table 3051ETEXI 3052DEFHEADING() 3053 3054DEFHEADING(Bluetooth(R) options:) 3055STEXI 3056@table @option 3057ETEXI 3058 3059DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3060 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3061 "-bt hci,host[:id]\n" \ 3062 " use host's HCI with the given name\n" \ 3063 "-bt hci[,vlan=n]\n" \ 3064 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3065 "-bt vhci[,vlan=n]\n" \ 3066 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3067 "-bt device:dev[,vlan=n]\n" \ 3068 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3069 QEMU_ARCH_ALL) 3070STEXI 3071@item -bt hci[...] 3072@findex -bt 3073Defines the function of the corresponding Bluetooth HCI. -bt options 3074are matched with the HCIs present in the chosen machine type. For 3075example when emulating a machine with only one HCI built into it, only 3076the first @code{-bt hci[...]} option is valid and defines the HCI's 3077logic. The Transport Layer is decided by the machine type. Currently 3078the machines @code{n800} and @code{n810} have one HCI and all other 3079machines have none. 3080 3081Note: This option and the whole bluetooth subsystem is considered as deprecated. 3082If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where 3083you describe your usecase. 3084 3085@anchor{bt-hcis} 3086The following three types are recognized: 3087 3088@table @option 3089@item -bt hci,null 3090(default) The corresponding Bluetooth HCI assumes no internal logic 3091and will not respond to any HCI commands or emit events. 3092 3093@item -bt hci,host[:@var{id}] 3094(@code{bluez} only) The corresponding HCI passes commands / events 3095to / from the physical HCI identified by the name @var{id} (default: 3096@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3097capable systems like Linux. 3098 3099@item -bt hci[,vlan=@var{n}] 3100Add a virtual, standard HCI that will participate in the Bluetooth 3101scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3102VLANs, devices inside a bluetooth network @var{n} can only communicate 3103with other devices in the same network (scatternet). 3104@end table 3105 3106@item -bt vhci[,vlan=@var{n}] 3107(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3108to the host bluetooth stack instead of to the emulated target. This 3109allows the host and target machines to participate in a common scatternet 3110and communicate. Requires the Linux @code{vhci} driver installed. Can 3111be used as following: 3112 3113@example 3114@value{qemu_system} [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3115@end example 3116 3117@item -bt device:@var{dev}[,vlan=@var{n}] 3118Emulate a bluetooth device @var{dev} and place it in network @var{n} 3119(default @code{0}). QEMU can only emulate one type of bluetooth devices 3120currently: 3121 3122@table @option 3123@item keyboard 3124Virtual wireless keyboard implementing the HIDP bluetooth profile. 3125@end table 3126ETEXI 3127 3128STEXI 3129@end table 3130ETEXI 3131DEFHEADING() 3132 3133#ifdef CONFIG_TPM 3134DEFHEADING(TPM device options:) 3135 3136DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3137 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3138 " use path to provide path to a character device; default is /dev/tpm0\n" 3139 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3140 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3141 "-tpmdev emulator,id=id,chardev=dev\n" 3142 " configure the TPM device using chardev backend\n", 3143 QEMU_ARCH_ALL) 3144STEXI 3145 3146The general form of a TPM device option is: 3147@table @option 3148 3149@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3150@findex -tpmdev 3151 3152The specific backend type will determine the applicable options. 3153The @code{-tpmdev} option creates the TPM backend and requires a 3154@code{-device} option that specifies the TPM frontend interface model. 3155 3156Use @code{-tpmdev help} to print all available TPM backend types. 3157 3158@end table 3159 3160The available backends are: 3161 3162@table @option 3163 3164@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3165 3166(Linux-host only) Enable access to the host's TPM using the passthrough 3167driver. 3168 3169@option{path} specifies the path to the host's TPM device, i.e., on 3170a Linux host this would be @code{/dev/tpm0}. 3171@option{path} is optional and by default @code{/dev/tpm0} is used. 3172 3173@option{cancel-path} specifies the path to the host TPM device's sysfs 3174entry allowing for cancellation of an ongoing TPM command. 3175@option{cancel-path} is optional and by default QEMU will search for the 3176sysfs entry to use. 3177 3178Some notes about using the host's TPM with the passthrough driver: 3179 3180The TPM device accessed by the passthrough driver must not be 3181used by any other application on the host. 3182 3183Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3184the VM's firmware (BIOS/UEFI) will not be able to initialize the 3185TPM again and may therefore not show a TPM-specific menu that would 3186otherwise allow the user to configure the TPM, e.g., allow the user to 3187enable/disable or activate/deactivate the TPM. 3188Further, if TPM ownership is released from within a VM then the host's TPM 3189will get disabled and deactivated. To enable and activate the 3190TPM again afterwards, the host has to be rebooted and the user is 3191required to enter the firmware's menu to enable and activate the TPM. 3192If the TPM is left disabled and/or deactivated most TPM commands will fail. 3193 3194To create a passthrough TPM use the following two options: 3195@example 3196-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3197@end example 3198Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3199@code{tpmdev=tpm0} in the device option. 3200 3201@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3202 3203(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3204chardev backend. 3205 3206@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3207 3208To create a TPM emulator backend device with chardev socket backend: 3209@example 3210 3211-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3212 3213@end example 3214 3215ETEXI 3216 3217STEXI 3218@end table 3219ETEXI 3220DEFHEADING() 3221 3222#endif 3223 3224DEFHEADING(Linux/Multiboot boot specific:) 3225STEXI 3226 3227When using these options, you can use a given Linux or Multiboot 3228kernel without installing it in the disk image. It can be useful 3229for easier testing of various kernels. 3230 3231@table @option 3232ETEXI 3233 3234DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3235 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3236STEXI 3237@item -kernel @var{bzImage} 3238@findex -kernel 3239Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3240or in multiboot format. 3241ETEXI 3242 3243DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3244 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3245STEXI 3246@item -append @var{cmdline} 3247@findex -append 3248Use @var{cmdline} as kernel command line 3249ETEXI 3250 3251DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3252 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3253STEXI 3254@item -initrd @var{file} 3255@findex -initrd 3256Use @var{file} as initial ram disk. 3257 3258@item -initrd "@var{file1} arg=foo,@var{file2}" 3259 3260This syntax is only available with multiboot. 3261 3262Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3263first module. 3264ETEXI 3265 3266DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3267 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3268STEXI 3269@item -dtb @var{file} 3270@findex -dtb 3271Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3272on boot. 3273ETEXI 3274 3275STEXI 3276@end table 3277ETEXI 3278DEFHEADING() 3279 3280DEFHEADING(Debug/Expert options:) 3281STEXI 3282@table @option 3283ETEXI 3284 3285DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3286 "-fw_cfg [name=]<name>,file=<file>\n" 3287 " add named fw_cfg entry with contents from file\n" 3288 "-fw_cfg [name=]<name>,string=<str>\n" 3289 " add named fw_cfg entry with contents from string\n", 3290 QEMU_ARCH_ALL) 3291STEXI 3292 3293@item -fw_cfg [name=]@var{name},file=@var{file} 3294@findex -fw_cfg 3295Add named fw_cfg entry with contents from file @var{file}. 3296 3297@item -fw_cfg [name=]@var{name},string=@var{str} 3298Add named fw_cfg entry with contents from string @var{str}. 3299 3300The terminating NUL character of the contents of @var{str} will not be 3301included as part of the fw_cfg item data. To insert contents with 3302embedded NUL characters, you have to use the @var{file} parameter. 3303 3304The fw_cfg entries are passed by QEMU through to the guest. 3305 3306Example: 3307@example 3308 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3309@end example 3310creates an fw_cfg entry named opt/com.mycompany/blob with contents 3311from ./my_blob.bin. 3312 3313ETEXI 3314 3315DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3316 "-serial dev redirect the serial port to char device 'dev'\n", 3317 QEMU_ARCH_ALL) 3318STEXI 3319@item -serial @var{dev} 3320@findex -serial 3321Redirect the virtual serial port to host character device 3322@var{dev}. The default device is @code{vc} in graphical mode and 3323@code{stdio} in non graphical mode. 3324 3325This option can be used several times to simulate up to 4 serial 3326ports. 3327 3328Use @code{-serial none} to disable all serial ports. 3329 3330Available character devices are: 3331@table @option 3332@item vc[:@var{W}x@var{H}] 3333Virtual console. Optionally, a width and height can be given in pixel with 3334@example 3335vc:800x600 3336@end example 3337It is also possible to specify width or height in characters: 3338@example 3339vc:80Cx24C 3340@end example 3341@item pty 3342[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3343@item none 3344No device is allocated. 3345@item null 3346void device 3347@item chardev:@var{id} 3348Use a named character device defined with the @code{-chardev} option. 3349@item /dev/XXX 3350[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3351parameters are set according to the emulated ones. 3352@item /dev/parport@var{N} 3353[Linux only, parallel port only] Use host parallel port 3354@var{N}. Currently SPP and EPP parallel port features can be used. 3355@item file:@var{filename} 3356Write output to @var{filename}. No character can be read. 3357@item stdio 3358[Unix only] standard input/output 3359@item pipe:@var{filename} 3360name pipe @var{filename} 3361@item COM@var{n} 3362[Windows only] Use host serial port @var{n} 3363@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3364This implements UDP Net Console. 3365When @var{remote_host} or @var{src_ip} are not specified 3366they default to @code{0.0.0.0}. 3367When not using a specified @var{src_port} a random port is automatically chosen. 3368 3369If you just want a simple readonly console you can use @code{netcat} or 3370@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3371@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3372will appear in the netconsole session. 3373 3374If you plan to send characters back via netconsole or you want to stop 3375and start QEMU a lot of times, you should have QEMU use the same 3376source port each time by using something like @code{-serial 3377udp::4555@@:4556} to QEMU. Another approach is to use a patched 3378version of netcat which can listen to a TCP port and send and receive 3379characters via udp. If you have a patched version of netcat which 3380activates telnet remote echo and single char transfer, then you can 3381use the following options to set up a netcat redirector to allow 3382telnet on port 5555 to access the QEMU port. 3383@table @code 3384@item QEMU Options: 3385-serial udp::4555@@:4556 3386@item netcat options: 3387-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3388@item telnet options: 3389localhost 5555 3390@end table 3391 3392@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3393The TCP Net Console has two modes of operation. It can send the serial 3394I/O to a location or wait for a connection from a location. By default 3395the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3396the @var{server} option QEMU will wait for a client socket application 3397to connect to the port before continuing, unless the @code{nowait} 3398option was specified. The @code{nodelay} option disables the Nagle buffering 3399algorithm. The @code{reconnect} option only applies if @var{noserver} is 3400set, if the connection goes down it will attempt to reconnect at the 3401given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3402one TCP connection at a time is accepted. You can use @code{telnet} to 3403connect to the corresponding character device. 3404@table @code 3405@item Example to send tcp console to 192.168.0.2 port 4444 3406-serial tcp:192.168.0.2:4444 3407@item Example to listen and wait on port 4444 for connection 3408-serial tcp::4444,server 3409@item Example to not wait and listen on ip 192.168.0.100 port 4444 3410-serial tcp:192.168.0.100:4444,server,nowait 3411@end table 3412 3413@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3414The telnet protocol is used instead of raw tcp sockets. The options 3415work the same as if you had specified @code{-serial tcp}. The 3416difference is that the port acts like a telnet server or client using 3417telnet option negotiation. This will also allow you to send the 3418MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3419sequence. Typically in unix telnet you do it with Control-] and then 3420type "send break" followed by pressing the enter key. 3421 3422@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3423The WebSocket protocol is used instead of raw tcp socket. The port acts as 3424a WebSocket server. Client mode is not supported. 3425 3426@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3427A unix domain socket is used instead of a tcp socket. The option works the 3428same as if you had specified @code{-serial tcp} except the unix domain socket 3429@var{path} is used for connections. 3430 3431@item mon:@var{dev_string} 3432This is a special option to allow the monitor to be multiplexed onto 3433another serial port. The monitor is accessed with key sequence of 3434@key{Control-a} and then pressing @key{c}. 3435@var{dev_string} should be any one of the serial devices specified 3436above. An example to multiplex the monitor onto a telnet server 3437listening on port 4444 would be: 3438@table @code 3439@item -serial mon:telnet::4444,server,nowait 3440@end table 3441When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3442QEMU any more but will be passed to the guest instead. 3443 3444@item braille 3445Braille device. This will use BrlAPI to display the braille output on a real 3446or fake device. 3447 3448@item msmouse 3449Three button serial mouse. Configure the guest to use Microsoft protocol. 3450@end table 3451ETEXI 3452 3453DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3454 "-parallel dev redirect the parallel port to char device 'dev'\n", 3455 QEMU_ARCH_ALL) 3456STEXI 3457@item -parallel @var{dev} 3458@findex -parallel 3459Redirect the virtual parallel port to host device @var{dev} (same 3460devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3461be used to use hardware devices connected on the corresponding host 3462parallel port. 3463 3464This option can be used several times to simulate up to 3 parallel 3465ports. 3466 3467Use @code{-parallel none} to disable all parallel ports. 3468ETEXI 3469 3470DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3471 "-monitor dev redirect the monitor to char device 'dev'\n", 3472 QEMU_ARCH_ALL) 3473STEXI 3474@item -monitor @var{dev} 3475@findex -monitor 3476Redirect the monitor to host device @var{dev} (same devices as the 3477serial port). 3478The default device is @code{vc} in graphical mode and @code{stdio} in 3479non graphical mode. 3480Use @code{-monitor none} to disable the default monitor. 3481ETEXI 3482DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3483 "-qmp dev like -monitor but opens in 'control' mode\n", 3484 QEMU_ARCH_ALL) 3485STEXI 3486@item -qmp @var{dev} 3487@findex -qmp 3488Like -monitor but opens in 'control' mode. 3489ETEXI 3490DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3491 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3492 QEMU_ARCH_ALL) 3493STEXI 3494@item -qmp-pretty @var{dev} 3495@findex -qmp-pretty 3496Like -qmp but uses pretty JSON formatting. 3497ETEXI 3498 3499DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3500 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3501STEXI 3502@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3503@findex -mon 3504Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3505easing human reading and debugging. 3506ETEXI 3507 3508DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3509 "-debugcon dev redirect the debug console to char device 'dev'\n", 3510 QEMU_ARCH_ALL) 3511STEXI 3512@item -debugcon @var{dev} 3513@findex -debugcon 3514Redirect the debug console to host device @var{dev} (same devices as the 3515serial port). The debug console is an I/O port which is typically port 35160xe9; writing to that I/O port sends output to this device. 3517The default device is @code{vc} in graphical mode and @code{stdio} in 3518non graphical mode. 3519ETEXI 3520 3521DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3522 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3523STEXI 3524@item -pidfile @var{file} 3525@findex -pidfile 3526Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3527from a script. 3528ETEXI 3529 3530DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3531 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3532STEXI 3533@item -singlestep 3534@findex -singlestep 3535Run the emulation in single step mode. 3536ETEXI 3537 3538DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3539 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3540 QEMU_ARCH_ALL) 3541STEXI 3542@item --preconfig 3543@findex --preconfig 3544Pause QEMU for interactive configuration before the machine is created, 3545which allows querying and configuring properties that will affect 3546machine initialization. Use QMP command 'x-exit-preconfig' to exit 3547the preconfig state and move to the next state (i.e. run guest if -S 3548isn't used or pause the second time if -S is used). This option is 3549experimental. 3550ETEXI 3551 3552DEF("S", 0, QEMU_OPTION_S, \ 3553 "-S freeze CPU at startup (use 'c' to start execution)\n", 3554 QEMU_ARCH_ALL) 3555STEXI 3556@item -S 3557@findex -S 3558Do not start CPU at startup (you must type 'c' in the monitor). 3559ETEXI 3560 3561DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3562 "-realtime [mlock=on|off]\n" 3563 " run qemu with realtime features\n" 3564 " mlock=on|off controls mlock support (default: on)\n", 3565 QEMU_ARCH_ALL) 3566STEXI 3567@item -realtime mlock=on|off 3568@findex -realtime 3569Run qemu with realtime features. 3570mlocking qemu and guest memory can be enabled via @option{mlock=on} 3571(enabled by default). 3572ETEXI 3573 3574DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3575 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3576 " run qemu with overcommit hints\n" 3577 " mem-lock=on|off controls memory lock support (default: off)\n" 3578 " cpu-pm=on|off controls cpu power management (default: off)\n", 3579 QEMU_ARCH_ALL) 3580STEXI 3581@item -overcommit mem-lock=on|off 3582@item -overcommit cpu-pm=on|off 3583@findex -overcommit 3584Run qemu with hints about host resource overcommit. The default is 3585to assume that host overcommits all resources. 3586 3587Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3588by default). This works when host memory is not overcommitted and reduces the 3589worst-case latency for guest. This is equivalent to @option{realtime}. 3590 3591Guest ability to manage power state of host cpus (increasing latency for other 3592processes on the same host cpu, but decreasing latency for guest) can be 3593enabled via @option{cpu-pm=on} (disabled by default). This works best when 3594host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3595utilization will be incorrect, not taking into account guest idle time. 3596ETEXI 3597 3598DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3599 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3600STEXI 3601@item -gdb @var{dev} 3602@findex -gdb 3603Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3604connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3605stdio are reasonable use case. The latter is allowing to start QEMU from 3606within gdb and establish the connection via a pipe: 3607@example 3608(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3609@end example 3610ETEXI 3611 3612DEF("s", 0, QEMU_OPTION_s, \ 3613 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3614 QEMU_ARCH_ALL) 3615STEXI 3616@item -s 3617@findex -s 3618Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3619(@pxref{gdb_usage}). 3620ETEXI 3621 3622DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3623 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3624 QEMU_ARCH_ALL) 3625STEXI 3626@item -d @var{item1}[,...] 3627@findex -d 3628Enable logging of specified items. Use '-d help' for a list of log items. 3629ETEXI 3630 3631DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3632 "-D logfile output log to logfile (default stderr)\n", 3633 QEMU_ARCH_ALL) 3634STEXI 3635@item -D @var{logfile} 3636@findex -D 3637Output log in @var{logfile} instead of to stderr 3638ETEXI 3639 3640DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3641 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3642 QEMU_ARCH_ALL) 3643STEXI 3644@item -dfilter @var{range1}[,...] 3645@findex -dfilter 3646Filter debug output to that relevant to a range of target addresses. The filter 3647spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3648@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3649addresses and sizes required. For example: 3650@example 3651 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3652@end example 3653Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3654the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3655block starting at 0xffffffc00005f000. 3656ETEXI 3657 3658DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3659 "-seed number seed the pseudo-random number generator\n", 3660 QEMU_ARCH_ALL) 3661STEXI 3662@item -seed @var{number} 3663@findex -seed 3664Force the guest to use a deterministic pseudo-random number generator, seeded 3665with @var{number}. This does not affect crypto routines within the host. 3666ETEXI 3667 3668DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3669 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3670 QEMU_ARCH_ALL) 3671STEXI 3672@item -L @var{path} 3673@findex -L 3674Set the directory for the BIOS, VGA BIOS and keymaps. 3675 3676To list all the data directories, use @code{-L help}. 3677ETEXI 3678 3679DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3680 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3681STEXI 3682@item -bios @var{file} 3683@findex -bios 3684Set the filename for the BIOS. 3685ETEXI 3686 3687DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3688 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3689STEXI 3690@item -enable-kvm 3691@findex -enable-kvm 3692Enable KVM full virtualization support. This option is only available 3693if KVM support is enabled when compiling. 3694ETEXI 3695 3696DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3697 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3698DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3699 "-xen-attach attach to existing xen domain\n" 3700 " libxl will use this when starting QEMU\n", 3701 QEMU_ARCH_ALL) 3702DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3703 "-xen-domid-restrict restrict set of available xen operations\n" 3704 " to specified domain id. (Does not affect\n" 3705 " xenpv machine type).\n", 3706 QEMU_ARCH_ALL) 3707STEXI 3708@item -xen-domid @var{id} 3709@findex -xen-domid 3710Specify xen guest domain @var{id} (XEN only). 3711@item -xen-attach 3712@findex -xen-attach 3713Attach to existing xen domain. 3714libxl will use this when starting QEMU (XEN only). 3715@findex -xen-domid-restrict 3716Restrict set of available xen operations to specified domain id (XEN only). 3717ETEXI 3718 3719DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3720 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3721STEXI 3722@item -no-reboot 3723@findex -no-reboot 3724Exit instead of rebooting. 3725ETEXI 3726 3727DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3728 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3729STEXI 3730@item -no-shutdown 3731@findex -no-shutdown 3732Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3733This allows for instance switching to monitor to commit changes to the 3734disk image. 3735ETEXI 3736 3737DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3738 "-loadvm [tag|id]\n" \ 3739 " start right away with a saved state (loadvm in monitor)\n", 3740 QEMU_ARCH_ALL) 3741STEXI 3742@item -loadvm @var{file} 3743@findex -loadvm 3744Start right away with a saved state (@code{loadvm} in monitor) 3745ETEXI 3746 3747#ifndef _WIN32 3748DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3749 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3750#endif 3751STEXI 3752@item -daemonize 3753@findex -daemonize 3754Daemonize the QEMU process after initialization. QEMU will not detach from 3755standard IO until it is ready to receive connections on any of its devices. 3756This option is a useful way for external programs to launch QEMU without having 3757to cope with initialization race conditions. 3758ETEXI 3759 3760DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3761 "-option-rom rom load a file, rom, into the option ROM space\n", 3762 QEMU_ARCH_ALL) 3763STEXI 3764@item -option-rom @var{file} 3765@findex -option-rom 3766Load the contents of @var{file} as an option ROM. 3767This option is useful to load things like EtherBoot. 3768ETEXI 3769 3770DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3771 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3772 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3773 QEMU_ARCH_ALL) 3774 3775STEXI 3776 3777@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3778@findex -rtc 3779Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3780UTC or local time, respectively. @code{localtime} is required for correct date in 3781MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3782format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3783 3784By default the RTC is driven by the host system time. This allows using of the 3785RTC as accurate reference clock inside the guest, specifically if the host 3786time is smoothly following an accurate external reference clock, e.g. via NTP. 3787If you want to isolate the guest time from the host, you can set @option{clock} 3788to @code{rt} instead, which provides a host monotonic clock if host support it. 3789To even prevent the RTC from progressing during suspension, you can set @option{clock} 3790to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3791icount mode in order to preserve determinism; however, note that in icount mode 3792the speed of the virtual clock is variable and can in general differ from the 3793host clock. 3794 3795Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3796specifically with Windows' ACPI HAL. This option will try to figure out how 3797many timer interrupts were not processed by the Windows guest and will 3798re-inject them. 3799ETEXI 3800 3801DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3802 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3803 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3804 " instruction, enable aligning the host and virtual clocks\n" \ 3805 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3806STEXI 3807@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3808@findex -icount 3809Enable virtual instruction counter. The virtual cpu will execute one 3810instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3811then the virtual cpu speed will be automatically adjusted to keep virtual 3812time within a few seconds of real time. 3813 3814When the virtual cpu is sleeping, the virtual time will advance at default 3815speed unless @option{sleep=on|off} is specified. 3816With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3817instantly whenever the virtual cpu goes to sleep mode and will not advance 3818if no timer is enabled. This behavior give deterministic execution times from 3819the guest point of view. 3820 3821Note that while this option can give deterministic behavior, it does not 3822provide cycle accurate emulation. Modern CPUs contain superscalar out of 3823order cores with complex cache hierarchies. The number of instructions 3824executed often has little or no correlation with actual performance. 3825 3826@option{align=on} will activate the delay algorithm which will try 3827to synchronise the host clock and the virtual clock. The goal is to 3828have a guest running at the real frequency imposed by the shift option. 3829Whenever the guest clock is behind the host clock and if 3830@option{align=on} is specified then we print a message to the user 3831to inform about the delay. 3832Currently this option does not work when @option{shift} is @code{auto}. 3833Note: The sync algorithm will work for those shift values for which 3834the guest clock runs ahead of the host clock. Typically this happens 3835when the shift value is high (how high depends on the host machine). 3836 3837When @option{rr} option is specified deterministic record/replay is enabled. 3838Replay log is written into @var{filename} file in record mode and 3839read from this file in replay mode. 3840 3841Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3842at the start of execution recording. In replay mode this option is used 3843to load the initial VM state. 3844ETEXI 3845 3846DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3847 "-watchdog model\n" \ 3848 " enable virtual hardware watchdog [default=none]\n", 3849 QEMU_ARCH_ALL) 3850STEXI 3851@item -watchdog @var{model} 3852@findex -watchdog 3853Create a virtual hardware watchdog device. Once enabled (by a guest 3854action), the watchdog must be periodically polled by an agent inside 3855the guest or else the guest will be restarted. Choose a model for 3856which your guest has drivers. 3857 3858The @var{model} is the model of hardware watchdog to emulate. Use 3859@code{-watchdog help} to list available hardware models. Only one 3860watchdog can be enabled for a guest. 3861 3862The following models may be available: 3863@table @option 3864@item ib700 3865iBASE 700 is a very simple ISA watchdog with a single timer. 3866@item i6300esb 3867Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3868dual-timer watchdog. 3869@item diag288 3870A virtual watchdog for s390x backed by the diagnose 288 hypercall 3871(currently KVM only). 3872@end table 3873ETEXI 3874 3875DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3876 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3877 " action when watchdog fires [default=reset]\n", 3878 QEMU_ARCH_ALL) 3879STEXI 3880@item -watchdog-action @var{action} 3881@findex -watchdog-action 3882 3883The @var{action} controls what QEMU will do when the watchdog timer 3884expires. 3885The default is 3886@code{reset} (forcefully reset the guest). 3887Other possible actions are: 3888@code{shutdown} (attempt to gracefully shutdown the guest), 3889@code{poweroff} (forcefully poweroff the guest), 3890@code{inject-nmi} (inject a NMI into the guest), 3891@code{pause} (pause the guest), 3892@code{debug} (print a debug message and continue), or 3893@code{none} (do nothing). 3894 3895Note that the @code{shutdown} action requires that the guest responds 3896to ACPI signals, which it may not be able to do in the sort of 3897situations where the watchdog would have expired, and thus 3898@code{-watchdog-action shutdown} is not recommended for production use. 3899 3900Examples: 3901 3902@table @code 3903@item -watchdog i6300esb -watchdog-action pause 3904@itemx -watchdog ib700 3905@end table 3906ETEXI 3907 3908DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3909 "-echr chr set terminal escape character instead of ctrl-a\n", 3910 QEMU_ARCH_ALL) 3911STEXI 3912 3913@item -echr @var{numeric_ascii_value} 3914@findex -echr 3915Change the escape character used for switching to the monitor when using 3916monitor and serial sharing. The default is @code{0x01} when using the 3917@code{-nographic} option. @code{0x01} is equal to pressing 3918@code{Control-a}. You can select a different character from the ascii 3919control keys where 1 through 26 map to Control-a through Control-z. For 3920instance you could use the either of the following to change the escape 3921character to Control-t. 3922@table @code 3923@item -echr 0x14 3924@itemx -echr 20 3925@end table 3926ETEXI 3927 3928DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3929 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3930STEXI 3931@item -show-cursor 3932@findex -show-cursor 3933Show cursor. 3934ETEXI 3935 3936DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3937 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3938STEXI 3939@item -tb-size @var{n} 3940@findex -tb-size 3941Set TB size. 3942ETEXI 3943 3944DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3945 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3946 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3947 "-incoming unix:socketpath\n" \ 3948 " prepare for incoming migration, listen on\n" \ 3949 " specified protocol and socket address\n" \ 3950 "-incoming fd:fd\n" \ 3951 "-incoming exec:cmdline\n" \ 3952 " accept incoming migration on given file descriptor\n" \ 3953 " or from given external command\n" \ 3954 "-incoming defer\n" \ 3955 " wait for the URI to be specified via migrate_incoming\n", 3956 QEMU_ARCH_ALL) 3957STEXI 3958@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3959@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3960@findex -incoming 3961Prepare for incoming migration, listen on a given tcp port. 3962 3963@item -incoming unix:@var{socketpath} 3964Prepare for incoming migration, listen on a given unix socket. 3965 3966@item -incoming fd:@var{fd} 3967Accept incoming migration from a given filedescriptor. 3968 3969@item -incoming exec:@var{cmdline} 3970Accept incoming migration as an output from specified external command. 3971 3972@item -incoming defer 3973Wait for the URI to be specified via migrate_incoming. The monitor can 3974be used to change settings (such as migration parameters) prior to issuing 3975the migrate_incoming to allow the migration to begin. 3976ETEXI 3977 3978DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3979 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3980STEXI 3981@item -only-migratable 3982@findex -only-migratable 3983Only allow migratable devices. Devices will not be allowed to enter an 3984unmigratable state. 3985ETEXI 3986 3987DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3988 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3989STEXI 3990@item -nodefaults 3991@findex -nodefaults 3992Don't create default devices. Normally, QEMU sets the default devices like serial 3993port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3994CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3995default devices. 3996ETEXI 3997 3998#ifndef _WIN32 3999DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4000 "-chroot dir chroot to dir just before starting the VM\n", 4001 QEMU_ARCH_ALL) 4002#endif 4003STEXI 4004@item -chroot @var{dir} 4005@findex -chroot 4006Immediately before starting guest execution, chroot to the specified 4007directory. Especially useful in combination with -runas. 4008ETEXI 4009 4010#ifndef _WIN32 4011DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4012 "-runas user change to user id user just before starting the VM\n" \ 4013 " user can be numeric uid:gid instead\n", 4014 QEMU_ARCH_ALL) 4015#endif 4016STEXI 4017@item -runas @var{user} 4018@findex -runas 4019Immediately before starting guest execution, drop root privileges, switching 4020to the specified user. 4021ETEXI 4022 4023DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4024 "-prom-env variable=value\n" 4025 " set OpenBIOS nvram variables\n", 4026 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4027STEXI 4028@item -prom-env @var{variable}=@var{value} 4029@findex -prom-env 4030Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4031ETEXI 4032DEF("semihosting", 0, QEMU_OPTION_semihosting, 4033 "-semihosting semihosting mode\n", 4034 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4035 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4036STEXI 4037@item -semihosting 4038@findex -semihosting 4039Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4040ETEXI 4041DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4042 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4043 " semihosting configuration\n", 4044QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4045QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4046STEXI 4047@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4048@findex -semihosting-config 4049Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4050@table @option 4051@item target=@code{native|gdb|auto} 4052Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4053or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4054during debug sessions and @code{native} otherwise. 4055@item chardev=@var{str1} 4056Send the output to a chardev backend output for native or auto output when not in gdb 4057@item arg=@var{str1},arg=@var{str2},... 4058Allows the user to pass input arguments, and can be used multiple times to build 4059up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4060command line is still supported for backward compatibility. If both the 4061@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4062specified, the former is passed to semihosting as it always takes precedence. 4063@end table 4064ETEXI 4065DEF("old-param", 0, QEMU_OPTION_old_param, 4066 "-old-param old param mode\n", QEMU_ARCH_ARM) 4067STEXI 4068@item -old-param 4069@findex -old-param (ARM) 4070Old param mode (ARM only). 4071ETEXI 4072 4073DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4074 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4075 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4076 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4077 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4078 " by the kernel, but typically no longer used by modern\n" \ 4079 " C library implementations.\n" \ 4080 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4081 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4082 " The value 'children' will deny set*uid|gid system calls for\n" \ 4083 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4084 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4085 " blacklisting *fork and execve\n" \ 4086 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4087 QEMU_ARCH_ALL) 4088STEXI 4089@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4090@findex -sandbox 4091Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4092disable it. The default is 'off'. 4093@table @option 4094@item obsolete=@var{string} 4095Enable Obsolete system calls 4096@item elevateprivileges=@var{string} 4097Disable set*uid|gid system calls 4098@item spawn=@var{string} 4099Disable *fork and execve 4100@item resourcecontrol=@var{string} 4101Disable process affinity and schedular priority 4102@end table 4103ETEXI 4104 4105DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4106 "-readconfig <file>\n", QEMU_ARCH_ALL) 4107STEXI 4108@item -readconfig @var{file} 4109@findex -readconfig 4110Read device configuration from @var{file}. This approach is useful when you want to spawn 4111QEMU process with many command line options but you don't want to exceed the command line 4112character limit. 4113ETEXI 4114DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4115 "-writeconfig <file>\n" 4116 " read/write config file\n", QEMU_ARCH_ALL) 4117STEXI 4118@item -writeconfig @var{file} 4119@findex -writeconfig 4120Write device configuration to @var{file}. The @var{file} can be either filename to save 4121command line and device configuration into file or dash @code{-}) character to print the 4122output to stdout. This can be later used as input file for @code{-readconfig} option. 4123ETEXI 4124 4125DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4126 "-no-user-config\n" 4127 " do not load default user-provided config files at startup\n", 4128 QEMU_ARCH_ALL) 4129STEXI 4130@item -no-user-config 4131@findex -no-user-config 4132The @code{-no-user-config} option makes QEMU not load any of the user-provided 4133config files on @var{sysconfdir}. 4134ETEXI 4135 4136DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4137 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4138 " specify tracing options\n", 4139 QEMU_ARCH_ALL) 4140STEXI 4141HXCOMM This line is not accurate, as some sub-options are backend-specific but 4142HXCOMM HX does not support conditional compilation of text. 4143@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4144@findex -trace 4145@include qemu-option-trace.texi 4146ETEXI 4147 4148HXCOMM Internal use 4149DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4150DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4151 4152#ifdef __linux__ 4153DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4154 "-enable-fips enable FIPS 140-2 compliance\n", 4155 QEMU_ARCH_ALL) 4156#endif 4157STEXI 4158@item -enable-fips 4159@findex -enable-fips 4160Enable FIPS 140-2 compliance mode. 4161ETEXI 4162 4163HXCOMM Deprecated by -accel tcg 4164DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4165 4166DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4167 "-msg timestamp[=on|off]\n" 4168 " change the format of messages\n" 4169 " on|off controls leading timestamps (default:on)\n", 4170 QEMU_ARCH_ALL) 4171STEXI 4172@item -msg timestamp[=on|off] 4173@findex -msg 4174prepend a timestamp to each log message.(default:on) 4175ETEXI 4176 4177DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4178 "-dump-vmstate <file>\n" 4179 " Output vmstate information in JSON format to file.\n" 4180 " Use the scripts/vmstate-static-checker.py file to\n" 4181 " check for possible regressions in migration code\n" 4182 " by comparing two such vmstate dumps.\n", 4183 QEMU_ARCH_ALL) 4184STEXI 4185@item -dump-vmstate @var{file} 4186@findex -dump-vmstate 4187Dump json-encoded vmstate information for current machine type to file 4188in @var{file} 4189ETEXI 4190 4191DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4192 "-enable-sync-profile\n" 4193 " enable synchronization profiling\n", 4194 QEMU_ARCH_ALL) 4195STEXI 4196@item -enable-sync-profile 4197@findex -enable-sync-profile 4198Enable synchronization profiling. 4199ETEXI 4200 4201STEXI 4202@end table 4203ETEXI 4204DEFHEADING() 4205 4206DEFHEADING(Generic object creation:) 4207STEXI 4208@table @option 4209ETEXI 4210 4211DEF("object", HAS_ARG, QEMU_OPTION_object, 4212 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4213 " create a new object of type TYPENAME setting properties\n" 4214 " in the order they are specified. Note that the 'id'\n" 4215 " property must be set. These objects are placed in the\n" 4216 " '/objects' path.\n", 4217 QEMU_ARCH_ALL) 4218STEXI 4219@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4220@findex -object 4221Create a new object of type @var{typename} setting properties 4222in the order they are specified. Note that the 'id' 4223property must be set. These objects are placed in the 4224'/objects' path. 4225 4226@table @option 4227 4228@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} 4229 4230Creates a memory file backend object, which can be used to back 4231the guest RAM with huge pages. 4232 4233The @option{id} parameter is a unique ID that will be used to reference this 4234memory region when configuring the @option{-numa} argument. 4235 4236The @option{size} option provides the size of the memory region, and accepts 4237common suffixes, eg @option{500M}. 4238 4239The @option{mem-path} provides the path to either a shared memory or huge page 4240filesystem mount. 4241 4242The @option{share} boolean option determines whether the memory 4243region is marked as private to QEMU, or shared. The latter allows 4244a co-operating external process to access the QEMU memory region. 4245 4246The @option{share} is also required for pvrdma devices due to 4247limitations in the RDMA API provided by Linux. 4248 4249Setting share=on might affect the ability to configure NUMA 4250bindings for the memory backend under some circumstances, see 4251Documentation/vm/numa_memory_policy.txt on the Linux kernel 4252source tree for additional details. 4253 4254Setting the @option{discard-data} boolean option to @var{on} 4255indicates that file contents can be destroyed when QEMU exits, 4256to avoid unnecessarily flushing data to the backing file. Note 4257that @option{discard-data} is only an optimization, and QEMU 4258might not discard file contents if it aborts unexpectedly or is 4259terminated using SIGKILL. 4260 4261The @option{merge} boolean option enables memory merge, also known as 4262MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4263memory deduplication. 4264 4265Setting the @option{dump} boolean option to @var{off} excludes the memory from 4266core dumps. This feature is also known as MADV_DONTDUMP. 4267 4268The @option{prealloc} boolean option enables memory preallocation. 4269 4270The @option{host-nodes} option binds the memory range to a list of NUMA host 4271nodes. 4272 4273The @option{policy} option sets the NUMA policy to one of the following values: 4274 4275@table @option 4276@item @var{default} 4277default host policy 4278 4279@item @var{preferred} 4280prefer the given host node list for allocation 4281 4282@item @var{bind} 4283restrict memory allocation to the given host node list 4284 4285@item @var{interleave} 4286interleave memory allocations across the given host node list 4287@end table 4288 4289The @option{align} option specifies the base address alignment when 4290QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4291@option{2M}. Some backend store specified by @option{mem-path} 4292requires an alignment different than the default one used by QEMU, eg 4293the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4294such cases, users can specify the required alignment via this option. 4295 4296The @option{pmem} option specifies whether the backing file specified 4297by @option{mem-path} is in host persistent memory that can be accessed 4298using the SNIA NVM programming model (e.g. Intel NVDIMM). 4299If @option{pmem} is set to 'on', QEMU will take necessary operations to 4300guarantee the persistence of its own writes to @option{mem-path} 4301(e.g. in vNVDIMM label emulation and live migration). 4302Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4303file metadata is in sync for @option{mem-path} in case of host crash 4304or a power failure. MAP_SYNC requires support from both the host kernel 4305(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4306with DAX option. 4307 4308@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} 4309 4310Creates a memory backend object, which can be used to back the guest RAM. 4311Memory backend objects offer more control than the @option{-m} option that is 4312traditionally used to define guest RAM. Please refer to 4313@option{memory-backend-file} for a description of the options. 4314 4315@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} 4316 4317Creates an anonymous memory file backend object, which allows QEMU to 4318share the memory with an external process (e.g. when using 4319vhost-user). The memory is allocated with memfd and optional 4320sealing. (Linux only) 4321 4322The @option{seal} option creates a sealed-file, that will block 4323further resizing the memory ('on' by default). 4324 4325The @option{hugetlb} option specify the file to be created resides in 4326the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4327the @option{hugetlb} option, the @option{hugetlbsize} option specify 4328the hugetlb page size on systems that support multiple hugetlb page 4329sizes (it must be a power of 2 value supported by the system). 4330 4331In some versions of Linux, the @option{hugetlb} option is incompatible 4332with the @option{seal} option (requires at least Linux 4.16). 4333 4334Please refer to @option{memory-backend-file} for a description of the 4335other options. 4336 4337The @option{share} boolean option is @var{on} by default with memfd. 4338 4339@item -object rng-builtin,id=@var{id} 4340 4341Creates a random number generator backend which obtains entropy from 4342QEMU builtin functions. The @option{id} parameter is a unique ID that 4343will be used to reference this entropy backend from the @option{virtio-rng} 4344device. By default, the @option{virtio-rng} device uses this RNG backend. 4345 4346@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4347 4348Creates a random number generator backend which obtains entropy from 4349a device on the host. The @option{id} parameter is a unique ID that 4350will be used to reference this entropy backend from the @option{virtio-rng} 4351device. The @option{filename} parameter specifies which file to obtain 4352entropy from and if omitted defaults to @option{/dev/urandom}. 4353 4354@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4355 4356Creates a random number generator backend which obtains entropy from 4357an external daemon running on the host. The @option{id} parameter is 4358a unique ID that will be used to reference this entropy backend from 4359the @option{virtio-rng} device. The @option{chardev} parameter is 4360the unique ID of a character device backend that provides the connection 4361to the RNG daemon. 4362 4363@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4364 4365Creates a TLS anonymous credentials object, which can be used to provide 4366TLS support on network backends. The @option{id} parameter is a unique 4367ID which network backends will use to access the credentials. The 4368@option{endpoint} is either @option{server} or @option{client} depending 4369on whether the QEMU network backend that uses the credentials will be 4370acting as a client or as a server. If @option{verify-peer} is enabled 4371(the default) then once the handshake is completed, the peer credentials 4372will be verified, though this is a no-op for anonymous credentials. 4373 4374The @var{dir} parameter tells QEMU where to find the credential 4375files. For server endpoints, this directory may contain a file 4376@var{dh-params.pem} providing diffie-hellman parameters to use 4377for the TLS server. If the file is missing, QEMU will generate 4378a set of DH parameters at startup. This is a computationally 4379expensive operation that consumes random pool entropy, so it is 4380recommended that a persistent set of parameters be generated 4381upfront and saved. 4382 4383@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4384 4385Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4386TLS support on network backends. The @option{id} parameter is a unique 4387ID which network backends will use to access the credentials. The 4388@option{endpoint} is either @option{server} or @option{client} depending 4389on whether the QEMU network backend that uses the credentials will be 4390acting as a client or as a server. For clients only, @option{username} 4391is the username which will be sent to the server. If omitted 4392it defaults to ``qemu''. 4393 4394The @var{dir} parameter tells QEMU where to find the keys file. 4395It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4396pairs. This file can most easily be created using the GnuTLS 4397@code{psktool} program. 4398 4399For server endpoints, @var{dir} may also contain a file 4400@var{dh-params.pem} providing diffie-hellman parameters to use 4401for the TLS server. If the file is missing, QEMU will generate 4402a set of DH parameters at startup. This is a computationally 4403expensive operation that consumes random pool entropy, so it is 4404recommended that a persistent set of parameters be generated 4405up front and saved. 4406 4407@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} 4408 4409Creates a TLS anonymous credentials object, which can be used to provide 4410TLS support on network backends. The @option{id} parameter is a unique 4411ID which network backends will use to access the credentials. The 4412@option{endpoint} is either @option{server} or @option{client} depending 4413on whether the QEMU network backend that uses the credentials will be 4414acting as a client or as a server. If @option{verify-peer} is enabled 4415(the default) then once the handshake is completed, the peer credentials 4416will be verified. With x509 certificates, this implies that the clients 4417must be provided with valid client certificates too. 4418 4419The @var{dir} parameter tells QEMU where to find the credential 4420files. For server endpoints, this directory may contain a file 4421@var{dh-params.pem} providing diffie-hellman parameters to use 4422for the TLS server. If the file is missing, QEMU will generate 4423a set of DH parameters at startup. This is a computationally 4424expensive operation that consumes random pool entropy, so it is 4425recommended that a persistent set of parameters be generated 4426upfront and saved. 4427 4428For x509 certificate credentials the directory will contain further files 4429providing the x509 certificates. The certificates must be stored 4430in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4431@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4432@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4433 4434For the @var{server-key.pem} and @var{client-key.pem} files which 4435contain sensitive private keys, it is possible to use an encrypted 4436version by providing the @var{passwordid} parameter. This provides 4437the ID of a previously created @code{secret} object containing the 4438password for decryption. 4439 4440The @var{priority} parameter allows to override the global default 4441priority used by gnutls. This can be useful if the system administrator 4442needs to use a weaker set of crypto priorities for QEMU without 4443potentially forcing the weakness onto all applications. Or conversely 4444if one wants wants a stronger default for QEMU than for all other 4445applications, they can do this through this parameter. Its format is 4446a gnutls priority string as described at 4447@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4448 4449@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4450 4451Interval @var{t} can't be 0, this filter batches the packet delivery: all 4452packets arriving in a given interval on netdev @var{netdevid} are delayed 4453until the end of the interval. Interval is in microseconds. 4454@option{status} is optional that indicate whether the netfilter is 4455on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4456 4457queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4458 4459@option{all}: the filter is attached both to the receive and the transmit 4460 queue of the netdev (default). 4461 4462@option{rx}: the filter is attached to the receive queue of the netdev, 4463 where it will receive packets sent to the netdev. 4464 4465@option{tx}: the filter is attached to the transmit queue of the netdev, 4466 where it will receive packets sent by the netdev. 4467 4468@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4469 4470filter-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. 4471 4472@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4473 4474filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4475@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4476filter-redirector will redirect packet with vnet_hdr_len. 4477Create a filter-redirector we need to differ outdev id from indev id, id can not 4478be the same. we can just use indev or outdev, but at least one of indev or outdev 4479need to be specified. 4480 4481@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4482 4483Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4484secondary from primary to keep secondary tcp connection,and rewrite 4485tcp packet to primary from secondary make tcp packet can be handled by 4486client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4487 4488usage: 4489colo secondary: 4490-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4491-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4492-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4493 4494@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4495 4496Dump the network traffic on netdev @var{dev} to the file specified by 4497@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4498The file format is libpcap, so it can be analyzed with tools such as tcpdump 4499or Wireshark. 4500 4501@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}] 4502 4503Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4504secondary packet. If the packets are same, we will output primary 4505packet to outdev@var{chardevid}, else we will notify colo-frame 4506do checkpoint and send primary packet to outdev@var{chardevid}. 4507In order to improve efficiency, we need to put the task of comparison 4508in another thread. If it has the vnet_hdr_support flag, colo compare 4509will send/recv packet with vnet_hdr_len. 4510If you want to use Xen COLO, will need the notify_dev to notify Xen 4511colo-frame to do checkpoint. 4512 4513we must use it with the help of filter-mirror and filter-redirector. 4514 4515@example 4516 4517KVM COLO 4518 4519primary: 4520-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4521-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4522-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4523-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4524-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4525-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4526-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4527-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4528-object iothread,id=iothread1 4529-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4530-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4531-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4532-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4533 4534secondary: 4535-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4536-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4537-chardev socket,id=red0,host=3.3.3.3,port=9003 4538-chardev socket,id=red1,host=3.3.3.3,port=9004 4539-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4540-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4541 4542 4543Xen COLO 4544 4545primary: 4546-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4547-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4548-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4549-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4550-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4551-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4552-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4553-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4554-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4555-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4556-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4557-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4558-object iothread,id=iothread1 4559-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4560 4561secondary: 4562-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4563-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4564-chardev socket,id=red0,host=3.3.3.3,port=9003 4565-chardev socket,id=red1,host=3.3.3.3,port=9004 4566-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4567-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4568 4569@end example 4570 4571If you want to know the detail of above command line, you can read 4572the colo-compare git log. 4573 4574@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4575 4576Creates a cryptodev backend which executes crypto opreation from 4577the QEMU cipher APIS. The @var{id} parameter is 4578a unique ID that will be used to reference this cryptodev backend from 4579the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4580which specify the queue number of cryptodev backend, the default of 4581@var{queues} is 1. 4582 4583@example 4584 4585 # @value{qemu_system} \ 4586 [...] \ 4587 -object cryptodev-backend-builtin,id=cryptodev0 \ 4588 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4589 [...] 4590@end example 4591 4592@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4593 4594Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4595The @var{id} parameter is a unique ID that will be used to reference this 4596cryptodev backend from the @option{virtio-crypto} device. 4597The chardev should be a unix domain socket backed one. The vhost-user uses 4598a specifically defined protocol to pass vhost ioctl replacement messages 4599to an application on the other end of the socket. 4600The @var{queues} parameter is optional, which specify the queue number 4601of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4602 4603@example 4604 4605 # @value{qemu_system} \ 4606 [...] \ 4607 -chardev socket,id=chardev0,path=/path/to/socket \ 4608 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4609 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4610 [...] 4611@end example 4612 4613@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4614@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4615 4616Defines a secret to store a password, encryption key, or some other sensitive 4617data. The sensitive data can either be passed directly via the @var{data} 4618parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4619parameter is insecure unless the sensitive data is encrypted. 4620 4621The sensitive data can be provided in raw format (the default), or base64. 4622When encoded as JSON, the raw format only supports valid UTF-8 characters, 4623so base64 is recommended for sending binary data. QEMU will convert from 4624which ever format is provided to the format it needs internally. eg, an 4625RBD password can be provided in raw format, even though it will be base64 4626encoded when passed onto the RBD sever. 4627 4628For added protection, it is possible to encrypt the data associated with 4629a secret using the AES-256-CBC cipher. Use of encryption is indicated 4630by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4631parameter provides the ID of a previously defined secret that contains 4632the AES-256 decryption key. This key should be 32-bytes long and be 4633base64 encoded. The @var{iv} parameter provides the random initialization 4634vector used for encryption of this particular secret and should be a 4635base64 encrypted string of the 16-byte IV. 4636 4637The simplest (insecure) usage is to provide the secret inline 4638 4639@example 4640 4641 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4642 4643@end example 4644 4645The simplest secure usage is to provide the secret via a file 4646 4647 # printf "letmein" > mypasswd.txt 4648 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4649 4650For greater security, AES-256-CBC should be used. To illustrate usage, 4651consider the openssl command line tool which can encrypt the data. Note 4652that when encrypting, the plaintext must be padded to the cipher block 4653size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4654 4655First a master key needs to be created in base64 encoding: 4656 4657@example 4658 # openssl rand -base64 32 > key.b64 4659 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4660@end example 4661 4662Each secret to be encrypted needs to have a random initialization vector 4663generated. These do not need to be kept secret 4664 4665@example 4666 # openssl rand -base64 16 > iv.b64 4667 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4668@end example 4669 4670The secret to be defined can now be encrypted, in this case we're 4671telling openssl to base64 encode the result, but it could be left 4672as raw bytes if desired. 4673 4674@example 4675 # SECRET=$(printf "letmein" | 4676 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4677@end example 4678 4679When launching QEMU, create a master secret pointing to @code{key.b64} 4680and specify that to be used to decrypt the user password. Pass the 4681contents of @code{iv.b64} to the second secret 4682 4683@example 4684 # @value{qemu_system} \ 4685 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4686 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4687 data=$SECRET,iv=$(<iv.b64) 4688@end example 4689 4690@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}] 4691 4692Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4693to provide the guest memory encryption support on AMD processors. 4694 4695When memory encryption is enabled, one of the physical address bit (aka the 4696C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4697is used to provide the C-bit position. The C-bit position is Host family dependent 4698hence user must provide this value. On EPYC, the value should be 47. 4699 4700When memory encryption is enabled, we loose certain bits in physical address space. 4701The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4702physical address space. Similar to C-bit, the value is Host family dependent. 4703On EPYC, the value should be 5. 4704 4705The @option{sev-device} provides the device file to use for communicating with 4706the SEV firmware running inside AMD Secure Processor. The default device is 4707'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4708created by CCP driver. 4709 4710The @option{policy} provides the guest policy to be enforced by the SEV firmware 4711and restrict what configuration and operational commands can be performed on this 4712guest by the hypervisor. The policy should be provided by the guest owner and is 4713bound to the guest and cannot be changed throughout the lifetime of the guest. 4714The default is 0. 4715 4716If guest @option{policy} allows sharing the key with another SEV guest then 4717@option{handle} can be use to provide handle of the guest from which to share 4718the key. 4719 4720The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4721Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4722are used for establishing a cryptographic session with the guest owner to 4723negotiate keys used for attestation. The file must be encoded in base64. 4724 4725e.g to launch a SEV guest 4726@example 4727 # @value{qemu_system_x86} \ 4728 ...... 4729 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4730 -machine ...,memory-encryption=sev0 4731 ..... 4732 4733@end example 4734 4735 4736@item -object authz-simple,id=@var{id},identity=@var{string} 4737 4738Create an authorization object that will control access to network services. 4739 4740The @option{identity} parameter is identifies the user and its format 4741depends on the network service that authorization object is associated 4742with. For authorizing based on TLS x509 certificates, the identity must 4743be the x509 distinguished name. Note that care must be taken to escape 4744any commas in the distinguished name. 4745 4746An example authorization object to validate a x509 distinguished name 4747would look like: 4748@example 4749 # @value{qemu_system} \ 4750 ... 4751 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4752 ... 4753@end example 4754 4755Note the use of quotes due to the x509 distinguished name containing 4756whitespace, and escaping of ','. 4757 4758@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4759 4760Create an authorization object that will control access to network services. 4761 4762The @option{filename} parameter is the fully qualified path to a file 4763containing the access control list rules in JSON format. 4764 4765An example set of rules that match against SASL usernames might look 4766like: 4767 4768@example 4769 @{ 4770 "rules": [ 4771 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4772 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4773 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4774 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4775 ], 4776 "policy": "deny" 4777 @} 4778@end example 4779 4780When checking access the object will iterate over all the rules and 4781the first rule to match will have its @option{policy} value returned 4782as the result. If no rules match, then the default @option{policy} 4783value is returned. 4784 4785The rules can either be an exact string match, or they can use the 4786simple UNIX glob pattern matching to allow wildcards to be used. 4787 4788If @option{refresh} is set to true the file will be monitored 4789and automatically reloaded whenever its content changes. 4790 4791As with the @code{authz-simple} object, the format of the identity 4792strings being matched depends on the network service, but is usually 4793a TLS x509 distinguished name, or a SASL username. 4794 4795An example authorization object to validate a SASL username 4796would look like: 4797@example 4798 # @value{qemu_system} \ 4799 ... 4800 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4801 ... 4802@end example 4803 4804@item -object authz-pam,id=@var{id},service=@var{string} 4805 4806Create an authorization object that will control access to network services. 4807 4808The @option{service} parameter provides the name of a PAM service to use 4809for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4810exist to provide the configuration for the @code{account} subsystem. 4811 4812An example authorization object to validate a TLS x509 distinguished 4813name would look like: 4814 4815@example 4816 # @value{qemu_system} \ 4817 ... 4818 -object authz-pam,id=auth0,service=qemu-vnc 4819 ... 4820@end example 4821 4822There would then be a corresponding config file for PAM at 4823@code{/etc/pam.d/qemu-vnc} that contains: 4824 4825@example 4826account requisite pam_listfile.so item=user sense=allow \ 4827 file=/etc/qemu/vnc.allow 4828@end example 4829 4830Finally the @code{/etc/qemu/vnc.allow} file would contain 4831the list of x509 distingished names that are permitted 4832access 4833 4834@example 4835CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4836@end example 4837 4838 4839@end table 4840 4841ETEXI 4842 4843 4844HXCOMM This is the last statement. Insert new options before this line! 4845STEXI 4846@end table 4847ETEXI 4848
