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-len= 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-len= 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=@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-len=@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}] 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 bmc=@var{id} 718The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 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@end table 728 729@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 730 731Add a connection to an external IPMI BMC simulator. Instead of 732locally emulating the BMC like the above item, instead connect 733to an external entity that provides the IPMI services. 734 735A connection is made to an external BMC simulator. If you do this, it 736is strongly recommended that you use the "reconnect=" chardev option 737to reconnect to the simulator if the connection is lost. Note that if 738this is not used carefully, it can be a security issue, as the 739interface has the ability to send resets, NMIs, and power off the VM. 740It's best if QEMU makes a connection to an external simulator running 741on a secure port on localhost, so neither the simulator nor QEMU is 742exposed to any outside network. 743 744See the "lanserv/README.vm" file in the OpenIPMI library for more 745details on the external interface. 746 747@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 748 749Add a KCS IPMI interafce on the ISA bus. This also adds a 750corresponding ACPI and SMBIOS entries, if appropriate. 751 752@table @option 753@item bmc=@var{id} 754The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 755@item ioport=@var{val} 756Define the I/O address of the interface. The default is 0xca0 for KCS. 757@item irq=@var{val} 758Define the interrupt to use. The default is 5. To disable interrupts, 759set this to 0. 760@end table 761 762@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 763 764Like the KCS interface, but defines a BT interface. The default port is 7650xe4 and the default interrupt is 5. 766 767ETEXI 768 769DEF("name", HAS_ARG, QEMU_OPTION_name, 770 "-name string1[,process=string2][,debug-threads=on|off]\n" 771 " set the name of the guest\n" 772 " string1 sets the window title and string2 the process name\n" 773 " When debug-threads is enabled, individual threads are given a separate name\n" 774 " NOTE: The thread names are for debugging and not a stable API.\n", 775 QEMU_ARCH_ALL) 776STEXI 777@item -name @var{name} 778@findex -name 779Sets the @var{name} of the guest. 780This name will be displayed in the SDL window caption. 781The @var{name} will also be used for the VNC server. 782Also optionally set the top visible process name in Linux. 783Naming of individual threads can also be enabled on Linux to aid debugging. 784ETEXI 785 786DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 787 "-uuid %08x-%04x-%04x-%04x-%012x\n" 788 " specify machine UUID\n", QEMU_ARCH_ALL) 789STEXI 790@item -uuid @var{uuid} 791@findex -uuid 792Set system UUID. 793ETEXI 794 795STEXI 796@end table 797ETEXI 798DEFHEADING() 799 800DEFHEADING(Block device options:) 801STEXI 802@table @option 803ETEXI 804 805DEF("fda", HAS_ARG, QEMU_OPTION_fda, 806 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 807DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 808STEXI 809@item -fda @var{file} 810@itemx -fdb @var{file} 811@findex -fda 812@findex -fdb 813Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 814ETEXI 815 816DEF("hda", HAS_ARG, QEMU_OPTION_hda, 817 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 818DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 819DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 820 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 821DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 822STEXI 823@item -hda @var{file} 824@itemx -hdb @var{file} 825@itemx -hdc @var{file} 826@itemx -hdd @var{file} 827@findex -hda 828@findex -hdb 829@findex -hdc 830@findex -hdd 831Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 832ETEXI 833 834DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 835 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 836 QEMU_ARCH_ALL) 837STEXI 838@item -cdrom @var{file} 839@findex -cdrom 840Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 841@option{-cdrom} at the same time). You can use the host CD-ROM by 842using @file{/dev/cdrom} as filename (@pxref{host_drives}). 843ETEXI 844 845DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 846 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 847 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 848 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n" 849 " [,driver specific parameters...]\n" 850 " configure a block backend\n", QEMU_ARCH_ALL) 851STEXI 852@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 853@findex -blockdev 854 855Define a new block driver node. Some of the options apply to all block drivers, 856other options are only accepted for a specific block driver. See below for a 857list of generic options and options for the most common block drivers. 858 859Options that expect a reference to another node (e.g. @code{file}) can be 860given in two ways. Either you specify the node name of an already existing node 861(file=@var{node-name}), or you define a new node inline, adding options 862for the referenced node after a dot (file.filename=@var{path},file.aio=native). 863 864A block driver node created with @option{-blockdev} can be used for a guest 865device by specifying its node name for the @code{drive} property in a 866@option{-device} argument that defines a block device. 867 868@table @option 869@item Valid options for any block driver node: 870 871@table @code 872@item driver 873Specifies the block driver to use for the given node. 874@item node-name 875This defines the name of the block driver node by which it will be referenced 876later. The name must be unique, i.e. it must not match the name of a different 877block driver node, or (if you use @option{-drive} as well) the ID of a drive. 878 879If no node name is specified, it is automatically generated. The generated node 880name is not intended to be predictable and changes between QEMU invocations. 881For the top level, an explicit node name must be specified. 882@item read-only 883Open the node read-only. Guest write attempts will fail. 884@item cache.direct 885The host page cache can be avoided with @option{cache.direct=on}. This will 886attempt to do disk IO directly to the guest's memory. QEMU may still perform an 887internal copy of the data. 888@item cache.no-flush 889In case you don't care about data integrity over host failures, you can use 890@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 891any data to the disk but can instead keep things in cache. If anything goes 892wrong, like your host losing power, the disk storage getting disconnected 893accidentally, etc. your image will most probably be rendered unusable. 894@item discard=@var{discard} 895@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 896whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 897ignored or passed to the filesystem. Some machine types may not support 898discard requests. 899@item detect-zeroes=@var{detect-zeroes} 900@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 901conversion of plain zero writes by the OS to driver specific optimized 902zero write commands. You may even choose "unmap" if @var{discard} is set 903to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 904@end table 905 906@item Driver-specific options for @code{file} 907 908This is the protocol-level block driver for accessing regular files. 909 910@table @code 911@item filename 912The path to the image file in the local filesystem 913@item aio 914Specifies the AIO backend (threads/native, default: threads) 915@item locking 916Specifies whether the image file is protected with Linux OFD / POSIX locks. The 917default is to use the Linux Open File Descriptor API if available, otherwise no 918lock is applied. (auto/on/off, default: auto) 919@end table 920Example: 921@example 922-blockdev driver=file,node-name=disk,filename=disk.img 923@end example 924 925@item Driver-specific options for @code{raw} 926 927This is the image format block driver for raw images. It is usually 928stacked on top of a protocol level block driver such as @code{file}. 929 930@table @code 931@item file 932Reference to or definition of the data source block driver node 933(e.g. a @code{file} driver node) 934@end table 935Example 1: 936@example 937-blockdev driver=file,node-name=disk_file,filename=disk.img 938-blockdev driver=raw,node-name=disk,file=disk_file 939@end example 940Example 2: 941@example 942-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 943@end example 944 945@item Driver-specific options for @code{qcow2} 946 947This is the image format block driver for qcow2 images. It is usually 948stacked on top of a protocol level block driver such as @code{file}. 949 950@table @code 951@item file 952Reference to or definition of the data source block driver node 953(e.g. a @code{file} driver node) 954 955@item backing 956Reference to or definition of the backing file block device (default is taken 957from the image file). It is allowed to pass @code{null} here in order to disable 958the default backing file. 959 960@item lazy-refcounts 961Whether to enable the lazy refcounts feature (on/off; default is taken from the 962image file) 963 964@item cache-size 965The maximum total size of the L2 table and refcount block caches in bytes 966(default: the sum of l2-cache-size and refcount-cache-size) 967 968@item l2-cache-size 969The maximum size of the L2 table cache in bytes 970(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 971non-Linux platforms; otherwise, as large as possible within the cache-size, 972while permitting the requested or the minimal refcount cache size) 973 974@item refcount-cache-size 975The maximum size of the refcount block cache in bytes 976(default: 4 times the cluster size; or if cache-size is specified, the part of 977it which is not used for the L2 cache) 978 979@item cache-clean-interval 980Clean unused entries in the L2 and refcount caches. The interval is in seconds. 981The default value is 600 on supporting platforms, and 0 on other platforms. 982Setting it to 0 disables this feature. 983 984@item pass-discard-request 985Whether discard requests to the qcow2 device should be forwarded to the data 986source (on/off; default: on if discard=unmap is specified, off otherwise) 987 988@item pass-discard-snapshot 989Whether discard requests for the data source should be issued when a snapshot 990operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 991default: on) 992 993@item pass-discard-other 994Whether discard requests for the data source should be issued on other 995occasions where a cluster gets freed (on/off; default: off) 996 997@item overlap-check 998Which overlap checks to perform for writes to the image 999(none/constant/cached/all; default: cached). For details or finer 1000granularity control refer to the QAPI documentation of @code{blockdev-add}. 1001@end table 1002 1003Example 1: 1004@example 1005-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1006-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1007@end example 1008Example 2: 1009@example 1010-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1011@end example 1012 1013@item Driver-specific options for other drivers 1014Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1015 1016@end table 1017 1018ETEXI 1019 1020DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1021 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1022 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1023 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1024 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1025 " [,readonly=on|off][,copy-on-read=on|off]\n" 1026 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1027 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1028 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1029 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1030 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1031 " [[,iops_size=is]]\n" 1032 " [[,group=g]]\n" 1033 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1034STEXI 1035@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1036@findex -drive 1037 1038Define a new drive. This includes creating a block driver node (the backend) as 1039well as a guest device, and is mostly a shortcut for defining the corresponding 1040@option{-blockdev} and @option{-device} options. 1041 1042@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1043addition, it knows the following options: 1044 1045@table @option 1046@item file=@var{file} 1047This option defines which disk image (@pxref{disk_images}) to use with 1048this drive. If the filename contains comma, you must double it 1049(for instance, "file=my,,file" to use file "my,file"). 1050 1051Special files such as iSCSI devices can be specified using protocol 1052specific URLs. See the section for "Device URL Syntax" for more information. 1053@item if=@var{interface} 1054This option defines on which type on interface the drive is connected. 1055Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1056@item bus=@var{bus},unit=@var{unit} 1057These options define where is connected the drive by defining the bus number and 1058the unit id. 1059@item index=@var{index} 1060This option defines where is connected the drive by using an index in the list 1061of available connectors of a given interface type. 1062@item media=@var{media} 1063This option defines the type of the media: disk or cdrom. 1064@item snapshot=@var{snapshot} 1065@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1066(see @option{-snapshot}). 1067@item cache=@var{cache} 1068@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1069and controls how the host cache is used to access block data. This is a 1070shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1071options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1072which provides a default for the @option{write-cache} option of block guest 1073devices (as in @option{-device}). The modes correspond to the following 1074settings: 1075 1076@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1077@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1078@c and the HTML output. 1079@example 1080@ │ cache.writeback cache.direct cache.no-flush 1081─────────────┼───────────────────────────────────────────────── 1082writeback │ on off off 1083none │ on on off 1084writethrough │ off off off 1085directsync │ off on off 1086unsafe │ on off on 1087@end example 1088 1089The default mode is @option{cache=writeback}. 1090 1091@item aio=@var{aio} 1092@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1093@item format=@var{format} 1094Specify which disk @var{format} will be used rather than detecting 1095the format. Can be used to specify format=raw to avoid interpreting 1096an untrusted format header. 1097@item werror=@var{action},rerror=@var{action} 1098Specify which @var{action} to take on write and read errors. Valid actions are: 1099"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1100"report" (report the error to the guest), "enospc" (pause QEMU only if the 1101host disk is full; report the error to the guest otherwise). 1102The default setting is @option{werror=enospc} and @option{rerror=report}. 1103@item copy-on-read=@var{copy-on-read} 1104@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1105file sectors into the image file. 1106@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1107Specify bandwidth throttling limits in bytes per second, either for all request 1108types or for reads or writes only. Small values can lead to timeouts or hangs 1109inside the guest. A safe minimum for disks is 2 MB/s. 1110@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1111Specify bursts in bytes per second, either for all request types or for reads 1112or writes only. Bursts allow the guest I/O to spike above the limit 1113temporarily. 1114@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1115Specify request rate limits in requests per second, either for all request 1116types or for reads or writes only. 1117@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1118Specify bursts in requests per second, either for all request types or for reads 1119or writes only. Bursts allow the guest I/O to spike above the limit 1120temporarily. 1121@item iops_size=@var{is} 1122Let every @var{is} bytes of a request count as a new request for iops 1123throttling purposes. Use this option to prevent guests from circumventing iops 1124limits by sending fewer but larger requests. 1125@item group=@var{g} 1126Join a throttling quota group with given name @var{g}. All drives that are 1127members of the same group are accounted for together. Use this option to 1128prevent guests from circumventing throttling limits by using many small disks 1129instead of a single larger disk. 1130@end table 1131 1132By default, the @option{cache.writeback=on} mode is used. It will report data 1133writes as completed as soon as the data is present in the host page cache. 1134This is safe as long as your guest OS makes sure to correctly flush disk caches 1135where needed. If your guest OS does not handle volatile disk write caches 1136correctly and your host crashes or loses power, then the guest may experience 1137data corruption. 1138 1139For such guests, you should consider using @option{cache.writeback=off}. This 1140means that the host page cache will be used to read and write data, but write 1141notification will be sent to the guest only after QEMU has made sure to flush 1142each write to the disk. Be aware that this has a major impact on performance. 1143 1144When using the @option{-snapshot} option, unsafe caching is always used. 1145 1146Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1147useful when the backing file is over a slow network. By default copy-on-read 1148is off. 1149 1150Instead of @option{-cdrom} you can use: 1151@example 1152@value{qemu_system} -drive file=file,index=2,media=cdrom 1153@end example 1154 1155Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1156use: 1157@example 1158@value{qemu_system} -drive file=file,index=0,media=disk 1159@value{qemu_system} -drive file=file,index=1,media=disk 1160@value{qemu_system} -drive file=file,index=2,media=disk 1161@value{qemu_system} -drive file=file,index=3,media=disk 1162@end example 1163 1164You can open an image using pre-opened file descriptors from an fd set: 1165@example 1166@value{qemu_system} \ 1167 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 1168 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 1169 -drive file=/dev/fdset/2,index=0,media=disk 1170@end example 1171 1172You can connect a CDROM to the slave of ide0: 1173@example 1174@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom 1175@end example 1176 1177If you don't specify the "file=" argument, you define an empty drive: 1178@example 1179@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom 1180@end example 1181 1182Instead of @option{-fda}, @option{-fdb}, you can use: 1183@example 1184@value{qemu_system_x86} -drive file=file,index=0,if=floppy 1185@value{qemu_system_x86} -drive file=file,index=1,if=floppy 1186@end example 1187 1188By default, @var{interface} is "ide" and @var{index} is automatically 1189incremented: 1190@example 1191@value{qemu_system_x86} -drive file=a -drive file=b" 1192@end example 1193is interpreted like: 1194@example 1195@value{qemu_system_x86} -hda a -hdb b 1196@end example 1197ETEXI 1198 1199DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1200 "-mtdblock file use 'file' as on-board Flash memory image\n", 1201 QEMU_ARCH_ALL) 1202STEXI 1203@item -mtdblock @var{file} 1204@findex -mtdblock 1205Use @var{file} as on-board Flash memory image. 1206ETEXI 1207 1208DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1209 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1210STEXI 1211@item -sd @var{file} 1212@findex -sd 1213Use @var{file} as SecureDigital card image. 1214ETEXI 1215 1216DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1217 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1218STEXI 1219@item -pflash @var{file} 1220@findex -pflash 1221Use @var{file} as a parallel flash image. 1222ETEXI 1223 1224DEF("snapshot", 0, QEMU_OPTION_snapshot, 1225 "-snapshot write to temporary files instead of disk image files\n", 1226 QEMU_ARCH_ALL) 1227STEXI 1228@item -snapshot 1229@findex -snapshot 1230Write to temporary files instead of disk image files. In this case, 1231the raw disk image you use is not written back. You can however force 1232the write back by pressing @key{C-a s} (@pxref{disk_images}). 1233ETEXI 1234 1235DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1236 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1237 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1238 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1239 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1240 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1241 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1242 " [[,throttling.iops-size=is]]\n" 1243 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1244 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1245 "-fsdev synth,id=id\n", 1246 QEMU_ARCH_ALL) 1247 1248STEXI 1249 1250@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}[,...]]] 1251@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1252@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1253@itemx -fsdev synth,id=@var{id}[,readonly] 1254@findex -fsdev 1255Define a new file system device. Valid options are: 1256@table @option 1257@item local 1258Accesses to the filesystem are done by QEMU. 1259@item proxy 1260Accesses to the filesystem are done by virtfs-proxy-helper(1). 1261@item synth 1262Synthetic filesystem, only used by QTests. 1263@item id=@var{id} 1264Specifies identifier for this device. 1265@item path=@var{path} 1266Specifies the export path for the file system device. Files under 1267this path will be available to the 9p client on the guest. 1268@item security_model=@var{security_model} 1269Specifies the security model to be used for this export path. 1270Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1271In "passthrough" security model, files are stored using the same 1272credentials as they are created on the guest. This requires QEMU 1273to run as root. In "mapped-xattr" security model, some of the file 1274attributes like uid, gid, mode bits and link target are stored as 1275file attributes. For "mapped-file" these attributes are stored in the 1276hidden .virtfs_metadata directory. Directories exported by this security model cannot 1277interact with other unix tools. "none" security model is same as 1278passthrough except the sever won't report failures if it fails to 1279set file attributes like ownership. Security model is mandatory 1280only for local fsdriver. Other fsdrivers (like proxy) don't take 1281security model as a parameter. 1282@item writeout=@var{writeout} 1283This is an optional argument. The only supported value is "immediate". 1284This means that host page cache will be used to read and write data but 1285write notification will be sent to the guest only when the data has been 1286reported as written by the storage subsystem. 1287@item readonly 1288Enables exporting 9p share as a readonly mount for guests. By default 1289read-write access is given. 1290@item socket=@var{socket} 1291Enables proxy filesystem driver to use passed socket file for communicating 1292with virtfs-proxy-helper(1). 1293@item sock_fd=@var{sock_fd} 1294Enables proxy filesystem driver to use passed socket descriptor for 1295communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1296will create socketpair and pass one of the fds as sock_fd. 1297@item fmode=@var{fmode} 1298Specifies the default mode for newly created files on the host. Works only 1299with security models "mapped-xattr" and "mapped-file". 1300@item dmode=@var{dmode} 1301Specifies the default mode for newly created directories on the host. Works 1302only with security models "mapped-xattr" and "mapped-file". 1303@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1304Specify bandwidth throttling limits in bytes per second, either for all request 1305types or for reads or writes only. 1306@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1307Specify bursts in bytes per second, either for all request types or for reads 1308or writes only. Bursts allow the guest I/O to spike above the limit 1309temporarily. 1310@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1311Specify request rate limits in requests per second, either for all request 1312types or for reads or writes only. 1313@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1314Specify bursts in requests per second, either for all request types or for reads 1315or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1316@item throttling.iops-size=@var{is} 1317Let every @var{is} bytes of a request count as a new request for iops 1318throttling purposes. 1319@end table 1320 1321-fsdev option is used along with -device driver "virtio-9p-...". 1322@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1323Options for virtio-9p-... driver are: 1324@table @option 1325@item @var{type} 1326Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1327depending on the machine type. 1328@item fsdev=@var{id} 1329Specifies the id value specified along with -fsdev option. 1330@item mount_tag=@var{mount_tag} 1331Specifies the tag name to be used by the guest to mount this export point. 1332@end table 1333 1334ETEXI 1335 1336DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1337 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1338 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1339 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1340 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1341 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1342 QEMU_ARCH_ALL) 1343 1344STEXI 1345 1346@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}] 1347@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1348@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1349@itemx -virtfs synth,mount_tag=@var{mount_tag} 1350@findex -virtfs 1351 1352Define 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: 1353@table @option 1354@item local 1355Accesses to the filesystem are done by QEMU. 1356@item proxy 1357Accesses to the filesystem are done by virtfs-proxy-helper(1). 1358@item synth 1359Synthetic filesystem, only used by QTests. 1360@item id=@var{id} 1361Specifies identifier for the filesystem device 1362@item path=@var{path} 1363Specifies the export path for the file system device. Files under 1364this path will be available to the 9p client on the guest. 1365@item security_model=@var{security_model} 1366Specifies the security model to be used for this export path. 1367Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1368In "passthrough" security model, files are stored using the same 1369credentials as they are created on the guest. This requires QEMU 1370to run as root. In "mapped-xattr" security model, some of the file 1371attributes like uid, gid, mode bits and link target are stored as 1372file attributes. For "mapped-file" these attributes are stored in the 1373hidden .virtfs_metadata directory. Directories exported by this security model cannot 1374interact with other unix tools. "none" security model is same as 1375passthrough except the sever won't report failures if it fails to 1376set file attributes like ownership. Security model is mandatory only 1377for local fsdriver. Other fsdrivers (like proxy) don't take security 1378model as a parameter. 1379@item writeout=@var{writeout} 1380This is an optional argument. The only supported value is "immediate". 1381This means that host page cache will be used to read and write data but 1382write notification will be sent to the guest only when the data has been 1383reported as written by the storage subsystem. 1384@item readonly 1385Enables exporting 9p share as a readonly mount for guests. By default 1386read-write access is given. 1387@item socket=@var{socket} 1388Enables proxy filesystem driver to use passed socket file for 1389communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1390will create socketpair and pass one of the fds as sock_fd. 1391@item sock_fd 1392Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1393descriptor for interfacing with virtfs-proxy-helper(1). 1394@item fmode=@var{fmode} 1395Specifies the default mode for newly created files on the host. Works only 1396with security models "mapped-xattr" and "mapped-file". 1397@item dmode=@var{dmode} 1398Specifies the default mode for newly created directories on the host. Works 1399only with security models "mapped-xattr" and "mapped-file". 1400@item mount_tag=@var{mount_tag} 1401Specifies the tag name to be used by the guest to mount this export point. 1402@end table 1403ETEXI 1404 1405DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1406 "-virtfs_synth Create synthetic file system image\n", 1407 QEMU_ARCH_ALL) 1408STEXI 1409@item -virtfs_synth 1410@findex -virtfs_synth 1411Create synthetic file system image. Note that this option is now deprecated. 1412Please use @code{-fsdev synth} and @code{-device virtio-9p-...} instead. 1413ETEXI 1414 1415DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1416 "-iscsi [user=user][,password=password]\n" 1417 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1418 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1419 " [,timeout=timeout]\n" 1420 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1421 1422STEXI 1423@item -iscsi 1424@findex -iscsi 1425Configure iSCSI session parameters. 1426ETEXI 1427 1428STEXI 1429@end table 1430ETEXI 1431DEFHEADING() 1432 1433DEFHEADING(USB options:) 1434STEXI 1435@table @option 1436ETEXI 1437 1438DEF("usb", 0, QEMU_OPTION_usb, 1439 "-usb enable on-board USB host controller (if not enabled by default)\n", 1440 QEMU_ARCH_ALL) 1441STEXI 1442@item -usb 1443@findex -usb 1444Enable USB emulation on machine types with an on-board USB host controller (if 1445not enabled by default). Note that on-board USB host controllers may not 1446support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1447on machines with PCI. 1448ETEXI 1449 1450DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1451 "-usbdevice name add the host or guest USB device 'name'\n", 1452 QEMU_ARCH_ALL) 1453STEXI 1454 1455@item -usbdevice @var{devname} 1456@findex -usbdevice 1457Add the USB device @var{devname}. Note that this option is deprecated, 1458please use @code{-device usb-...} instead. @xref{usb_devices}. 1459 1460@table @option 1461 1462@item mouse 1463Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1464 1465@item tablet 1466Pointer device that uses absolute coordinates (like a touchscreen). This 1467means QEMU is able to report the mouse position without having to grab the 1468mouse. Also overrides the PS/2 mouse emulation when activated. 1469 1470@item braille 1471Braille device. This will use BrlAPI to display the braille output on a real 1472or fake device. 1473 1474@end table 1475ETEXI 1476 1477STEXI 1478@end table 1479ETEXI 1480DEFHEADING() 1481 1482DEFHEADING(Display options:) 1483STEXI 1484@table @option 1485ETEXI 1486 1487DEF("display", HAS_ARG, QEMU_OPTION_display, 1488 "-display spice-app[,gl=on|off]\n" 1489 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1490 " [,window_close=on|off][,gl=on|core|es|off]\n" 1491 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1492 "-display vnc=<display>[,<optargs>]\n" 1493 "-display curses[,charset=<encoding>]\n" 1494 "-display none\n" 1495 "-display egl-headless[,rendernode=<file>]" 1496 " select display type\n" 1497 "The default display is equivalent to\n" 1498#if defined(CONFIG_GTK) 1499 "\t\"-display gtk\"\n" 1500#elif defined(CONFIG_SDL) 1501 "\t\"-display sdl\"\n" 1502#elif defined(CONFIG_COCOA) 1503 "\t\"-display cocoa\"\n" 1504#elif defined(CONFIG_VNC) 1505 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1506#else 1507 "\t\"-display none\"\n" 1508#endif 1509 , QEMU_ARCH_ALL) 1510STEXI 1511@item -display @var{type} 1512@findex -display 1513Select type of display to use. This option is a replacement for the 1514old style -sdl/-curses/... options. Valid values for @var{type} are 1515@table @option 1516@item sdl 1517Display video output via SDL (usually in a separate graphics 1518window; see the SDL documentation for other possibilities). 1519@item curses 1520Display video output via curses. For graphics device models which 1521support a text mode, QEMU can display this output using a 1522curses/ncurses interface. Nothing is displayed when the graphics 1523device is in graphical mode or if the graphics device does not support 1524a text mode. Generally only the VGA device models support text mode. 1525The font charset used by the guest can be specified with the 1526@code{charset} option, for example @code{charset=CP850} for IBM CP850 1527encoding. The default is @code{CP437}. 1528@item none 1529Do not display video output. The guest will still see an emulated 1530graphics card, but its output will not be displayed to the QEMU 1531user. This option differs from the -nographic option in that it 1532only affects what is done with video output; -nographic also changes 1533the destination of the serial and parallel port data. 1534@item gtk 1535Display video output in a GTK window. This interface provides drop-down 1536menus and other UI elements to configure and control the VM during 1537runtime. 1538@item vnc 1539Start a VNC server on display <arg> 1540@item egl-headless 1541Offload all OpenGL operations to a local DRI device. For any graphical display, 1542this display needs to be paired with either VNC or SPICE displays. 1543@item spice-app 1544Start QEMU as a Spice server and launch the default Spice client 1545application. The Spice server will redirect the serial consoles and 1546QEMU monitors. (Since 4.0) 1547@end table 1548ETEXI 1549 1550DEF("nographic", 0, QEMU_OPTION_nographic, 1551 "-nographic disable graphical output and redirect serial I/Os to console\n", 1552 QEMU_ARCH_ALL) 1553STEXI 1554@item -nographic 1555@findex -nographic 1556Normally, if QEMU is compiled with graphical window support, it displays 1557output such as guest graphics, guest console, and the QEMU monitor in a 1558window. With this option, you can totally disable graphical output so 1559that QEMU is a simple command line application. The emulated serial port 1560is redirected on the console and muxed with the monitor (unless 1561redirected elsewhere explicitly). Therefore, you can still use QEMU to 1562debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1563switching between the console and monitor. 1564ETEXI 1565 1566DEF("curses", 0, QEMU_OPTION_curses, 1567 "-curses shorthand for -display curses\n", 1568 QEMU_ARCH_ALL) 1569STEXI 1570@item -curses 1571@findex -curses 1572Normally, if QEMU is compiled with graphical window support, it displays 1573output such as guest graphics, guest console, and the QEMU monitor in a 1574window. With this option, QEMU can display the VGA output when in text 1575mode using a curses/ncurses interface. Nothing is displayed in graphical 1576mode. 1577ETEXI 1578 1579DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1580 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1581 QEMU_ARCH_ALL) 1582STEXI 1583@item -alt-grab 1584@findex -alt-grab 1585Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1586affects the special keys (for fullscreen, monitor-mode switching, etc). 1587ETEXI 1588 1589DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1590 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1591 QEMU_ARCH_ALL) 1592STEXI 1593@item -ctrl-grab 1594@findex -ctrl-grab 1595Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1596affects the special keys (for fullscreen, monitor-mode switching, etc). 1597ETEXI 1598 1599DEF("no-quit", 0, QEMU_OPTION_no_quit, 1600 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1601STEXI 1602@item -no-quit 1603@findex -no-quit 1604Disable SDL window close capability. 1605ETEXI 1606 1607DEF("sdl", 0, QEMU_OPTION_sdl, 1608 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1609STEXI 1610@item -sdl 1611@findex -sdl 1612Enable SDL. 1613ETEXI 1614 1615DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1616 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1617 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1618 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1619 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1620 " [,tls-ciphers=<list>]\n" 1621 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1622 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1623 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1624 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1625 " [,jpeg-wan-compression=[auto|never|always]]\n" 1626 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1627 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1628 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1629 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1630 " [,gl=[on|off]][,rendernode=<file>]\n" 1631 " enable spice\n" 1632 " at least one of {port, tls-port} is mandatory\n", 1633 QEMU_ARCH_ALL) 1634STEXI 1635@item -spice @var{option}[,@var{option}[,...]] 1636@findex -spice 1637Enable the spice remote desktop protocol. Valid options are 1638 1639@table @option 1640 1641@item port=<nr> 1642Set the TCP port spice is listening on for plaintext channels. 1643 1644@item addr=<addr> 1645Set the IP address spice is listening on. Default is any address. 1646 1647@item ipv4 1648@itemx ipv6 1649@itemx unix 1650Force using the specified IP version. 1651 1652@item password=<secret> 1653Set the password you need to authenticate. 1654 1655@item sasl 1656Require that the client use SASL to authenticate with the spice. 1657The exact choice of authentication method used is controlled from the 1658system / user's SASL configuration file for the 'qemu' service. This 1659is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1660unprivileged user, an environment variable SASL_CONF_PATH can be used 1661to make it search alternate locations for the service config. 1662While some SASL auth methods can also provide data encryption (eg GSSAPI), 1663it is recommended that SASL always be combined with the 'tls' and 1664'x509' settings to enable use of SSL and server certificates. This 1665ensures a data encryption preventing compromise of authentication 1666credentials. 1667 1668@item disable-ticketing 1669Allow client connects without authentication. 1670 1671@item disable-copy-paste 1672Disable copy paste between the client and the guest. 1673 1674@item disable-agent-file-xfer 1675Disable spice-vdagent based file-xfer between the client and the guest. 1676 1677@item tls-port=<nr> 1678Set the TCP port spice is listening on for encrypted channels. 1679 1680@item x509-dir=<dir> 1681Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1682 1683@item x509-key-file=<file> 1684@itemx x509-key-password=<file> 1685@itemx x509-cert-file=<file> 1686@itemx x509-cacert-file=<file> 1687@itemx x509-dh-key-file=<file> 1688The x509 file names can also be configured individually. 1689 1690@item tls-ciphers=<list> 1691Specify which ciphers to use. 1692 1693@item tls-channel=[main|display|cursor|inputs|record|playback] 1694@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1695Force specific channel to be used with or without TLS encryption. The 1696options can be specified multiple times to configure multiple 1697channels. The special name "default" can be used to set the default 1698mode. For channels which are not explicitly forced into one mode the 1699spice client is allowed to pick tls/plaintext as he pleases. 1700 1701@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1702Configure image compression (lossless). 1703Default is auto_glz. 1704 1705@item jpeg-wan-compression=[auto|never|always] 1706@itemx zlib-glz-wan-compression=[auto|never|always] 1707Configure wan image compression (lossy for slow links). 1708Default is auto. 1709 1710@item streaming-video=[off|all|filter] 1711Configure video stream detection. Default is off. 1712 1713@item agent-mouse=[on|off] 1714Enable/disable passing mouse events via vdagent. Default is on. 1715 1716@item playback-compression=[on|off] 1717Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1718 1719@item seamless-migration=[on|off] 1720Enable/disable spice seamless migration. Default is off. 1721 1722@item gl=[on|off] 1723Enable/disable OpenGL context. Default is off. 1724 1725@item rendernode=<file> 1726DRM render node for OpenGL rendering. If not specified, it will pick 1727the first available. (Since 2.9) 1728 1729@end table 1730ETEXI 1731 1732DEF("portrait", 0, QEMU_OPTION_portrait, 1733 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1734 QEMU_ARCH_ALL) 1735STEXI 1736@item -portrait 1737@findex -portrait 1738Rotate graphical output 90 deg left (only PXA LCD). 1739ETEXI 1740 1741DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1742 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1743 QEMU_ARCH_ALL) 1744STEXI 1745@item -rotate @var{deg} 1746@findex -rotate 1747Rotate graphical output some deg left (only PXA LCD). 1748ETEXI 1749 1750DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1751 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1752 " select video card type\n", QEMU_ARCH_ALL) 1753STEXI 1754@item -vga @var{type} 1755@findex -vga 1756Select type of VGA card to emulate. Valid values for @var{type} are 1757@table @option 1758@item cirrus 1759Cirrus Logic GD5446 Video card. All Windows versions starting from 1760Windows 95 should recognize and use this graphic card. For optimal 1761performances, use 16 bit color depth in the guest and the host OS. 1762(This card was the default before QEMU 2.2) 1763@item std 1764Standard VGA card with Bochs VBE extensions. If your guest OS 1765supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1766to use high resolution modes (>= 1280x1024x16) then you should use 1767this option. (This card is the default since QEMU 2.2) 1768@item vmware 1769VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1770recent XFree86/XOrg server or Windows guest with a driver for this 1771card. 1772@item qxl 1773QXL paravirtual graphic card. It is VGA compatible (including VESA 17742.0 VBE support). Works best with qxl guest drivers installed though. 1775Recommended choice when using the spice protocol. 1776@item tcx 1777(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1778sun4m machines and offers both 8-bit and 24-bit colour depths at a 1779fixed resolution of 1024x768. 1780@item cg3 1781(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1782for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1783resolutions aimed at people wishing to run older Solaris versions. 1784@item virtio 1785Virtio VGA card. 1786@item none 1787Disable VGA card. 1788@end table 1789ETEXI 1790 1791DEF("full-screen", 0, QEMU_OPTION_full_screen, 1792 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1793STEXI 1794@item -full-screen 1795@findex -full-screen 1796Start in full screen. 1797ETEXI 1798 1799DEF("g", 1, QEMU_OPTION_g , 1800 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1801 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1802STEXI 1803@item -g @var{width}x@var{height}[x@var{depth}] 1804@findex -g 1805Set the initial graphical resolution and depth (PPC, SPARC only). 1806ETEXI 1807 1808DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1809 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1810STEXI 1811@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1812@findex -vnc 1813Normally, if QEMU is compiled with graphical window support, it displays 1814output such as guest graphics, guest console, and the QEMU monitor in a 1815window. With this option, you can have QEMU listen on VNC display 1816@var{display} and redirect the VGA display over the VNC session. It is 1817very useful to enable the usb tablet device when using this option 1818(option @option{-device usb-tablet}). When using the VNC display, you 1819must use the @option{-k} parameter to set the keyboard layout if you are 1820not using en-us. Valid syntax for the @var{display} is 1821 1822@table @option 1823 1824@item to=@var{L} 1825 1826With this option, QEMU will try next available VNC @var{display}s, until the 1827number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1828available, e.g. port 5900+@var{display} is already used by another 1829application. By default, to=0. 1830 1831@item @var{host}:@var{d} 1832 1833TCP connections will only be allowed from @var{host} on display @var{d}. 1834By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1835be omitted in which case the server will accept connections from any host. 1836 1837@item unix:@var{path} 1838 1839Connections will be allowed over UNIX domain sockets where @var{path} is the 1840location of a unix socket to listen for connections on. 1841 1842@item none 1843 1844VNC is initialized but not started. The monitor @code{change} command 1845can be used to later start the VNC server. 1846 1847@end table 1848 1849Following the @var{display} value there may be one or more @var{option} flags 1850separated by commas. Valid options are 1851 1852@table @option 1853 1854@item reverse 1855 1856Connect to a listening VNC client via a ``reverse'' connection. The 1857client is specified by the @var{display}. For reverse network 1858connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1859is a TCP port number, not a display number. 1860 1861@item websocket 1862 1863Opens an additional TCP listening port dedicated to VNC Websocket connections. 1864If a bare @var{websocket} option is given, the Websocket port is 18655700+@var{display}. An alternative port can be specified with the 1866syntax @code{websocket}=@var{port}. 1867 1868If @var{host} is specified connections will only be allowed from this host. 1869It is possible to control the websocket listen address independently, using 1870the syntax @code{websocket}=@var{host}:@var{port}. 1871 1872If no TLS credentials are provided, the websocket connection runs in 1873unencrypted mode. If TLS credentials are provided, the websocket connection 1874requires encrypted client connections. 1875 1876@item password 1877 1878Require that password based authentication is used for client connections. 1879 1880The password must be set separately using the @code{set_password} command in 1881the @ref{pcsys_monitor}. The syntax to change your password is: 1882@code{set_password <protocol> <password>} where <protocol> could be either 1883"vnc" or "spice". 1884 1885If you would like to change <protocol> password expiration, you should use 1886@code{expire_password <protocol> <expiration-time>} where expiration time could 1887be one of the following options: now, never, +seconds or UNIX time of 1888expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1889to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1890date and time). 1891 1892You can also use keywords "now" or "never" for the expiration time to 1893allow <protocol> password to expire immediately or never expire. 1894 1895@item tls-creds=@var{ID} 1896 1897Provides the ID of a set of TLS credentials to use to secure the 1898VNC server. They will apply to both the normal VNC server socket 1899and the websocket socket (if enabled). Setting TLS credentials 1900will cause the VNC server socket to enable the VeNCrypt auth 1901mechanism. The credentials should have been previously created 1902using the @option{-object tls-creds} argument. 1903 1904@item tls-authz=@var{ID} 1905 1906Provides the ID of the QAuthZ authorization object against which 1907the client's x509 distinguished name will validated. This object is 1908only resolved at time of use, so can be deleted and recreated on the 1909fly while the VNC server is active. If missing, it will default 1910to denying access. 1911 1912@item sasl 1913 1914Require that the client use SASL to authenticate with the VNC server. 1915The exact choice of authentication method used is controlled from the 1916system / user's SASL configuration file for the 'qemu' service. This 1917is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1918unprivileged user, an environment variable SASL_CONF_PATH can be used 1919to make it search alternate locations for the service config. 1920While some SASL auth methods can also provide data encryption (eg GSSAPI), 1921it is recommended that SASL always be combined with the 'tls' and 1922'x509' settings to enable use of SSL and server certificates. This 1923ensures a data encryption preventing compromise of authentication 1924credentials. See the @ref{vnc_security} section for details on using 1925SASL authentication. 1926 1927@item sasl-authz=@var{ID} 1928 1929Provides the ID of the QAuthZ authorization object against which 1930the client's SASL username will validated. This object is 1931only resolved at time of use, so can be deleted and recreated on the 1932fly while the VNC server is active. If missing, it will default 1933to denying access. 1934 1935@item acl 1936 1937Legacy method for enabling authorization of clients against the 1938x509 distinguished name and SASL username. It results in the creation 1939of two @code{authz-list} objects with IDs of @code{vnc.username} and 1940@code{vnc.x509dname}. The rules for these objects must be configured 1941with the HMP ACL commands. 1942 1943This option is deprecated and should no longer be used. The new 1944@option{sasl-authz} and @option{tls-authz} options are a 1945replacement. 1946 1947@item lossy 1948 1949Enable lossy compression methods (gradient, JPEG, ...). If this 1950option is set, VNC client may receive lossy framebuffer updates 1951depending on its encoding settings. Enabling this option can save 1952a lot of bandwidth at the expense of quality. 1953 1954@item non-adaptive 1955 1956Disable adaptive encodings. Adaptive encodings are enabled by default. 1957An adaptive encoding will try to detect frequently updated screen regions, 1958and send updates in these regions using a lossy encoding (like JPEG). 1959This can be really helpful to save bandwidth when playing videos. Disabling 1960adaptive encodings restores the original static behavior of encodings 1961like Tight. 1962 1963@item share=[allow-exclusive|force-shared|ignore] 1964 1965Set display sharing policy. 'allow-exclusive' allows clients to ask 1966for exclusive access. As suggested by the rfb spec this is 1967implemented by dropping other connections. Connecting multiple 1968clients in parallel requires all clients asking for a shared session 1969(vncviewer: -shared switch). This is the default. 'force-shared' 1970disables exclusive client access. Useful for shared desktop sessions, 1971where you don't want someone forgetting specify -shared disconnect 1972everybody else. 'ignore' completely ignores the shared flag and 1973allows everybody connect unconditionally. Doesn't conform to the rfb 1974spec but is traditional QEMU behavior. 1975 1976@item key-delay-ms 1977 1978Set keyboard delay, for key down and key up events, in milliseconds. 1979Default is 10. Keyboards are low-bandwidth devices, so this slowdown 1980can help the device and guest to keep up and not lose events in case 1981events are arriving in bulk. Possible causes for the latter are flaky 1982network connections, or scripts for automated testing. 1983 1984@item audiodev=@var{audiodev} 1985 1986Use the specified @var{audiodev} when the VNC client requests audio 1987transmission. When not using an -audiodev argument, this option must 1988be omitted, otherwise is must be present and specify a valid audiodev. 1989 1990@end table 1991ETEXI 1992 1993STEXI 1994@end table 1995ETEXI 1996ARCHHEADING(, QEMU_ARCH_I386) 1997 1998ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1999STEXI 2000@table @option 2001ETEXI 2002 2003DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2004 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2005 QEMU_ARCH_I386) 2006STEXI 2007@item -win2k-hack 2008@findex -win2k-hack 2009Use it when installing Windows 2000 to avoid a disk full bug. After 2010Windows 2000 is installed, you no longer need this option (this option 2011slows down the IDE transfers). 2012ETEXI 2013 2014DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2015 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2016 QEMU_ARCH_I386) 2017STEXI 2018@item -no-fd-bootchk 2019@findex -no-fd-bootchk 2020Disable boot signature checking for floppy disks in BIOS. May 2021be needed to boot from old floppy disks. 2022ETEXI 2023 2024DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2025 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2026STEXI 2027@item -no-acpi 2028@findex -no-acpi 2029Disable ACPI (Advanced Configuration and Power Interface) support. Use 2030it if your guest OS complains about ACPI problems (PC target machine 2031only). 2032ETEXI 2033 2034DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2035 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2036STEXI 2037@item -no-hpet 2038@findex -no-hpet 2039Disable HPET support. 2040ETEXI 2041 2042DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2043 "-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" 2044 " ACPI table description\n", QEMU_ARCH_I386) 2045STEXI 2046@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}]...] 2047@findex -acpitable 2048Add ACPI table with specified header fields and context from specified files. 2049For file=, take whole ACPI table from the specified files, including all 2050ACPI headers (possible overridden by other options). 2051For data=, only data 2052portion of the table is used, all header information is specified in the 2053command line. 2054If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2055fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2056to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2057spec. 2058ETEXI 2059 2060DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2061 "-smbios file=binary\n" 2062 " load SMBIOS entry from binary file\n" 2063 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2064 " [,uefi=on|off]\n" 2065 " specify SMBIOS type 0 fields\n" 2066 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2067 " [,uuid=uuid][,sku=str][,family=str]\n" 2068 " specify SMBIOS type 1 fields\n" 2069 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2070 " [,asset=str][,location=str]\n" 2071 " specify SMBIOS type 2 fields\n" 2072 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2073 " [,sku=str]\n" 2074 " specify SMBIOS type 3 fields\n" 2075 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2076 " [,asset=str][,part=str]\n" 2077 " specify SMBIOS type 4 fields\n" 2078 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2079 " [,asset=str][,part=str][,speed=%d]\n" 2080 " specify SMBIOS type 17 fields\n", 2081 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2082STEXI 2083@item -smbios file=@var{binary} 2084@findex -smbios 2085Load SMBIOS entry from binary file. 2086 2087@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2088Specify SMBIOS type 0 fields 2089 2090@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}] 2091Specify SMBIOS type 1 fields 2092 2093@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2094Specify SMBIOS type 2 fields 2095 2096@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2097Specify SMBIOS type 3 fields 2098 2099@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2100Specify SMBIOS type 4 fields 2101 2102@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}] 2103Specify SMBIOS type 17 fields 2104ETEXI 2105 2106STEXI 2107@end table 2108ETEXI 2109DEFHEADING() 2110 2111DEFHEADING(Network options:) 2112STEXI 2113@table @option 2114ETEXI 2115 2116DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2117#ifdef CONFIG_SLIRP 2118 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2119 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2120 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2121 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2122 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2123#ifndef _WIN32 2124 "[,smb=dir[,smbserver=addr]]\n" 2125#endif 2126 " configure a user mode network backend with ID 'str',\n" 2127 " its DHCP server and optional services\n" 2128#endif 2129#ifdef _WIN32 2130 "-netdev tap,id=str,ifname=name\n" 2131 " configure a host TAP network backend with ID 'str'\n" 2132#else 2133 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2134 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2135 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2136 " [,poll-us=n]\n" 2137 " configure a host TAP network backend with ID 'str'\n" 2138 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2139 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2140 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2141 " to deconfigure it\n" 2142 " use '[down]script=no' to disable script execution\n" 2143 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2144 " configure it\n" 2145 " use 'fd=h' to connect to an already opened TAP interface\n" 2146 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2147 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2148 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2149 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2150 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2151 " use vhost=on to enable experimental in kernel accelerator\n" 2152 " (only has effect for virtio guests which use MSIX)\n" 2153 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2154 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2155 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2156 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2157 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2158 " spent on busy polling for vhost net\n" 2159 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2160 " configure a host TAP network backend with ID 'str' that is\n" 2161 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2162 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2163#endif 2164#ifdef __linux__ 2165 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2166 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2167 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2168 " [,rxcookie=rxcookie][,offset=offset]\n" 2169 " configure a network backend with ID 'str' connected to\n" 2170 " an Ethernet over L2TPv3 pseudowire.\n" 2171 " Linux kernel 3.3+ as well as most routers can talk\n" 2172 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2173 " VM to a router and even VM to Host. It is a nearly-universal\n" 2174 " standard (RFC3391). Note - this implementation uses static\n" 2175 " pre-configured tunnels (same as the Linux kernel).\n" 2176 " use 'src=' to specify source address\n" 2177 " use 'dst=' to specify destination address\n" 2178 " use 'udp=on' to specify udp encapsulation\n" 2179 " use 'srcport=' to specify source udp port\n" 2180 " use 'dstport=' to specify destination udp port\n" 2181 " use 'ipv6=on' to force v6\n" 2182 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2183 " well as a weak security measure\n" 2184 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2185 " use 'txcookie=0x012345678' to specify a txcookie\n" 2186 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2187 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2188 " use 'pincounter=on' to work around broken counter handling in peer\n" 2189 " use 'offset=X' to add an extra offset between header and data\n" 2190#endif 2191 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2192 " configure a network backend to connect to another network\n" 2193 " using a socket connection\n" 2194 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2195 " configure a network backend to connect to a multicast maddr and port\n" 2196 " use 'localaddr=addr' to specify the host address to send packets from\n" 2197 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2198 " configure a network backend to connect to another network\n" 2199 " using an UDP tunnel\n" 2200#ifdef CONFIG_VDE 2201 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2202 " configure a network backend to connect to port 'n' of a vde switch\n" 2203 " running on host and listening for incoming connections on 'socketpath'.\n" 2204 " Use group 'groupname' and mode 'octalmode' to change default\n" 2205 " ownership and permissions for communication port.\n" 2206#endif 2207#ifdef CONFIG_NETMAP 2208 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2209 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2210 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2211 " netmap device, defaults to '/dev/netmap')\n" 2212#endif 2213#ifdef CONFIG_POSIX 2214 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2215 " configure a vhost-user network, backed by a chardev 'dev'\n" 2216#endif 2217 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2218 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2219DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2220 "-nic [tap|bridge|" 2221#ifdef CONFIG_SLIRP 2222 "user|" 2223#endif 2224#ifdef __linux__ 2225 "l2tpv3|" 2226#endif 2227#ifdef CONFIG_VDE 2228 "vde|" 2229#endif 2230#ifdef CONFIG_NETMAP 2231 "netmap|" 2232#endif 2233#ifdef CONFIG_POSIX 2234 "vhost-user|" 2235#endif 2236 "socket][,option][,...][mac=macaddr]\n" 2237 " initialize an on-board / default host NIC (using MAC address\n" 2238 " macaddr) and connect it to the given host network backend\n" 2239 "-nic none use it alone to have zero network devices (the default is to\n" 2240 " provided a 'user' network connection)\n", 2241 QEMU_ARCH_ALL) 2242DEF("net", HAS_ARG, QEMU_OPTION_net, 2243 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2244 " configure or create an on-board (or machine default) NIC and\n" 2245 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2246 "-net [" 2247#ifdef CONFIG_SLIRP 2248 "user|" 2249#endif 2250 "tap|" 2251 "bridge|" 2252#ifdef CONFIG_VDE 2253 "vde|" 2254#endif 2255#ifdef CONFIG_NETMAP 2256 "netmap|" 2257#endif 2258 "socket][,option][,option][,...]\n" 2259 " old way to initialize a host network interface\n" 2260 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2261STEXI 2262@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2263@findex -nic 2264This option is a shortcut for configuring both the on-board (default) guest 2265NIC hardware and the host network backend in one go. The host backend options 2266are the same as with the corresponding @option{-netdev} options below. 2267The guest NIC model can be set with @option{model=@var{modelname}}. 2268Use @option{model=help} to list the available device types. 2269The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2270 2271The following two example do exactly the same, to show how @option{-nic} can 2272be used to shorten the command line length (note that the e1000 is the default 2273on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2274@example 2275@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2276@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2277@end example 2278 2279@item -nic none 2280Indicate that no network devices should be configured. It is used to override 2281the default configuration (default NIC with ``user'' host network backend) 2282which is activated if no other networking options are provided. 2283 2284@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2285@findex -netdev 2286Configure user mode host network backend which requires no administrator 2287privilege to run. Valid options are: 2288 2289@table @option 2290@item id=@var{id} 2291Assign symbolic name for use in monitor commands. 2292 2293@item ipv4=on|off and ipv6=on|off 2294Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2295both protocols are enabled. 2296 2297@item net=@var{addr}[/@var{mask}] 2298Set IP network address the guest will see. Optionally specify the netmask, 2299either in the form a.b.c.d or as number of valid top-most bits. Default is 230010.0.2.0/24. 2301 2302@item host=@var{addr} 2303Specify the guest-visible address of the host. Default is the 2nd IP in the 2304guest network, i.e. x.x.x.2. 2305 2306@item ipv6-net=@var{addr}[/@var{int}] 2307Set IPv6 network address the guest will see (default is fec0::/64). The 2308network prefix is given in the usual hexadecimal IPv6 address 2309notation. The prefix size is optional, and is given as the number of 2310valid top-most bits (default is 64). 2311 2312@item ipv6-host=@var{addr} 2313Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2314the guest network, i.e. xxxx::2. 2315 2316@item restrict=on|off 2317If this option is enabled, the guest will be isolated, i.e. it will not be 2318able to contact the host and no guest IP packets will be routed over the host 2319to the outside. This option does not affect any explicitly set forwarding rules. 2320 2321@item hostname=@var{name} 2322Specifies the client hostname reported by the built-in DHCP server. 2323 2324@item dhcpstart=@var{addr} 2325Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2326is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2327 2328@item dns=@var{addr} 2329Specify the guest-visible address of the virtual nameserver. The address must 2330be different from the host address. Default is the 3rd IP in the guest network, 2331i.e. x.x.x.3. 2332 2333@item ipv6-dns=@var{addr} 2334Specify the guest-visible address of the IPv6 virtual nameserver. The address 2335must be different from the host address. Default is the 3rd IP in the guest 2336network, i.e. xxxx::3. 2337 2338@item dnssearch=@var{domain} 2339Provides an entry for the domain-search list sent by the built-in 2340DHCP server. More than one domain suffix can be transmitted by specifying 2341this option multiple times. If supported, this will cause the guest to 2342automatically try to append the given domain suffix(es) in case a domain name 2343can not be resolved. 2344 2345Example: 2346@example 2347@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2348@end example 2349 2350@item domainname=@var{domain} 2351Specifies the client domain name reported by the built-in DHCP server. 2352 2353@item tftp=@var{dir} 2354When using the user mode network stack, activate a built-in TFTP 2355server. The files in @var{dir} will be exposed as the root of a TFTP server. 2356The TFTP client on the guest must be configured in binary mode (use the command 2357@code{bin} of the Unix TFTP client). 2358 2359@item tftp-server-name=@var{name} 2360In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 236166). This can be used to advise the guest to load boot files or configurations 2362from a different server than the host address. 2363 2364@item bootfile=@var{file} 2365When using the user mode network stack, broadcast @var{file} as the BOOTP 2366filename. In conjunction with @option{tftp}, this can be used to network boot 2367a guest from a local directory. 2368 2369Example (using pxelinux): 2370@example 2371@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2372 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2373@end example 2374 2375@item smb=@var{dir}[,smbserver=@var{addr}] 2376When using the user mode network stack, activate a built-in SMB 2377server so that Windows OSes can access to the host files in @file{@var{dir}} 2378transparently. The IP address of the SMB server can be set to @var{addr}. By 2379default the 4th IP in the guest network is used, i.e. x.x.x.4. 2380 2381In the guest Windows OS, the line: 2382@example 238310.0.2.4 smbserver 2384@end example 2385must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2386or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2387 2388Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2389 2390Note that a SAMBA server must be installed on the host OS. 2391 2392@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2393Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2394the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2395@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2396given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2397be bound to a specific host interface. If no connection type is set, TCP is 2398used. This option can be given multiple times. 2399 2400For example, to redirect host X11 connection from screen 1 to guest 2401screen 0, use the following: 2402 2403@example 2404# on the host 2405@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2406# this host xterm should open in the guest X11 server 2407xterm -display :1 2408@end example 2409 2410To redirect telnet connections from host port 5555 to telnet port on 2411the guest, use the following: 2412 2413@example 2414# on the host 2415@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2416telnet localhost 5555 2417@end example 2418 2419Then when you use on the host @code{telnet localhost 5555}, you 2420connect to the guest telnet server. 2421 2422@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2423@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2424Forward guest TCP connections to the IP address @var{server} on port @var{port} 2425to the character device @var{dev} or to a program executed by @var{cmd:command} 2426which gets spawned for each connection. This option can be given multiple times. 2427 2428You can either use a chardev directly and have that one used throughout QEMU's 2429lifetime, like in the following example: 2430 2431@example 2432# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2433# the guest accesses it 2434@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2435@end example 2436 2437Or you can execute a command on every TCP connection established by the guest, 2438so that QEMU behaves similar to an inetd process for that virtual server: 2439 2440@example 2441# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2442# and connect the TCP stream to its stdin/stdout 2443@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2444@end example 2445 2446@end table 2447 2448@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2449Configure a host TAP network backend with ID @var{id}. 2450 2451Use the network script @var{file} to configure it and the network script 2452@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2453automatically provides one. The default network configure script is 2454@file{/etc/qemu-ifup} and the default network deconfigure script is 2455@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2456to disable script execution. 2457 2458If running QEMU as an unprivileged user, use the network helper 2459@var{helper} to configure the TAP interface and attach it to the bridge. 2460The default network helper executable is @file{/path/to/qemu-bridge-helper} 2461and the default bridge device is @file{br0}. 2462 2463@option{fd}=@var{h} can be used to specify the handle of an already 2464opened host TAP interface. 2465 2466Examples: 2467 2468@example 2469#launch a QEMU instance with the default network script 2470@value{qemu_system} linux.img -nic tap 2471@end example 2472 2473@example 2474#launch a QEMU instance with two NICs, each one connected 2475#to a TAP device 2476@value{qemu_system} linux.img \ 2477 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2478 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2479@end example 2480 2481@example 2482#launch a QEMU instance with the default network helper to 2483#connect a TAP device to bridge br0 2484@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2485 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2486@end example 2487 2488@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2489Connect a host TAP network interface to a host bridge device. 2490 2491Use the network helper @var{helper} to configure the TAP interface and 2492attach it to the bridge. The default network helper executable is 2493@file{/path/to/qemu-bridge-helper} and the default bridge 2494device is @file{br0}. 2495 2496Examples: 2497 2498@example 2499#launch a QEMU instance with the default network helper to 2500#connect a TAP device to bridge br0 2501@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2502@end example 2503 2504@example 2505#launch a QEMU instance with the default network helper to 2506#connect a TAP device to bridge qemubr0 2507@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2508@end example 2509 2510@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2511 2512This host network backend can be used to connect the guest's network to 2513another QEMU virtual machine using a TCP socket connection. If @option{listen} 2514is specified, QEMU waits for incoming connections on @var{port} 2515(@var{host} is optional). @option{connect} is used to connect to 2516another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2517specifies an already opened TCP socket. 2518 2519Example: 2520@example 2521# launch a first QEMU instance 2522@value{qemu_system} linux.img \ 2523 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2524 -netdev socket,id=n1,listen=:1234 2525# connect the network of this instance to the network of the first instance 2526@value{qemu_system} linux.img \ 2527 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2528 -netdev socket,id=n2,connect=127.0.0.1:1234 2529@end example 2530 2531@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2532 2533Configure a socket host network backend to share the guest's network traffic 2534with another QEMU virtual machines using a UDP multicast socket, effectively 2535making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2536NOTES: 2537@enumerate 2538@item 2539Several QEMU can be running on different hosts and share same bus (assuming 2540correct multicast setup for these hosts). 2541@item 2542mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2543@url{http://user-mode-linux.sf.net}. 2544@item 2545Use @option{fd=h} to specify an already opened UDP multicast socket. 2546@end enumerate 2547 2548Example: 2549@example 2550# launch one QEMU instance 2551@value{qemu_system} linux.img \ 2552 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2553 -netdev socket,id=n1,mcast=230.0.0.1:1234 2554# launch another QEMU instance on same "bus" 2555@value{qemu_system} linux.img \ 2556 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2557 -netdev socket,id=n2,mcast=230.0.0.1:1234 2558# launch yet another QEMU instance on same "bus" 2559@value{qemu_system} linux.img \ 2560 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2561 -netdev socket,id=n3,mcast=230.0.0.1:1234 2562@end example 2563 2564Example (User Mode Linux compat.): 2565@example 2566# launch QEMU instance (note mcast address selected is UML's default) 2567@value{qemu_system} linux.img \ 2568 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2569 -netdev socket,id=n1,mcast=239.192.168.1:1102 2570# launch UML 2571/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2572@end example 2573 2574Example (send packets from host's 1.2.3.4): 2575@example 2576@value{qemu_system} linux.img \ 2577 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2578 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2579@end example 2580 2581@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}] 2582Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2583popular protocol to transport Ethernet (and other Layer 2) data frames between 2584two systems. It is present in routers, firewalls and the Linux kernel 2585(from version 3.3 onwards). 2586 2587This transport allows a VM to communicate to another VM, router or firewall directly. 2588 2589@table @option 2590@item src=@var{srcaddr} 2591 source address (mandatory) 2592@item dst=@var{dstaddr} 2593 destination address (mandatory) 2594@item udp 2595 select udp encapsulation (default is ip). 2596@item srcport=@var{srcport} 2597 source udp port. 2598@item dstport=@var{dstport} 2599 destination udp port. 2600@item ipv6 2601 force v6, otherwise defaults to v4. 2602@item rxcookie=@var{rxcookie} 2603@itemx txcookie=@var{txcookie} 2604 Cookies are a weak form of security in the l2tpv3 specification. 2605Their function is mostly to prevent misconfiguration. By default they are 32 2606bit. 2607@item cookie64 2608 Set cookie size to 64 bit instead of the default 32 2609@item counter=off 2610 Force a 'cut-down' L2TPv3 with no counter as in 2611draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2612@item pincounter=on 2613 Work around broken counter handling in peer. This may also help on 2614networks which have packet reorder. 2615@item offset=@var{offset} 2616 Add an extra offset between header and data 2617@end table 2618 2619For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2620on the remote Linux host 1.2.3.4: 2621@example 2622# Setup tunnel on linux host using raw ip as encapsulation 2623# on 1.2.3.4 2624ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2625 encap udp udp_sport 16384 udp_dport 16384 2626ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2627 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2628ifconfig vmtunnel0 mtu 1500 2629ifconfig vmtunnel0 up 2630brctl addif br-lan vmtunnel0 2631 2632 2633# on 4.3.2.1 2634# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2635 2636@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2637 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2638 2639@end example 2640 2641@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2642Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2643listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2644and MODE @var{octalmode} to change default ownership and permissions for 2645communication port. This option is only available if QEMU has been compiled 2646with vde support enabled. 2647 2648Example: 2649@example 2650# launch vde switch 2651vde_switch -F -sock /tmp/myswitch 2652# launch QEMU instance 2653@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2654@end example 2655 2656@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2657 2658Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2659be a unix domain socket backed one. The vhost-user uses a specifically defined 2660protocol to pass vhost ioctl replacement messages to an application on the other 2661end of the socket. On non-MSIX guests, the feature can be forced with 2662@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2663be created for multiqueue vhost-user. 2664 2665Example: 2666@example 2667qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2668 -numa node,memdev=mem \ 2669 -chardev socket,id=chr0,path=/path/to/socket \ 2670 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2671 -device virtio-net-pci,netdev=net0 2672@end example 2673 2674@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2675 2676Create a hub port on the emulated hub with ID @var{hubid}. 2677 2678The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2679single netdev. Alternatively, you can also connect the hubport to another 2680netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2681 2682@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2683@findex -net 2684Legacy option to configure or create an on-board (or machine default) Network 2685Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2686the default hub), or to the netdev @var{nd}. 2687The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2688can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2689only), and a @var{name} can be assigned for use in monitor commands. 2690Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2691that the card should have; this option currently only affects virtio cards; set 2692@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2693NIC is created. QEMU can emulate several different models of network card. 2694Use @code{-net nic,model=help} for a list of available devices for your target. 2695 2696@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2697Configure a host network backend (with the options corresponding to the same 2698@option{-netdev} option) and connect it to the emulated hub 0 (the default 2699hub). Use @var{name} to specify the name of the hub port. 2700ETEXI 2701 2702STEXI 2703@end table 2704ETEXI 2705DEFHEADING() 2706 2707DEFHEADING(Character device options:) 2708 2709DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2710 "-chardev help\n" 2711 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2712 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2713 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2714 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2715 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2716 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2717 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2718 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2719 " [,logfile=PATH][,logappend=on|off]\n" 2720 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2721 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2722 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2723 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2724 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2725 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2726#ifdef _WIN32 2727 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2728 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2729#else 2730 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2731 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2732#endif 2733#ifdef CONFIG_BRLAPI 2734 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2735#endif 2736#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2737 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2738 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2739 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2740#endif 2741#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2742 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2743 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2744#endif 2745#if defined(CONFIG_SPICE) 2746 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2747 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2748#endif 2749 , QEMU_ARCH_ALL 2750) 2751 2752STEXI 2753 2754The general form of a character device option is: 2755@table @option 2756@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2757@findex -chardev 2758Backend is one of: 2759@option{null}, 2760@option{socket}, 2761@option{udp}, 2762@option{msmouse}, 2763@option{vc}, 2764@option{ringbuf}, 2765@option{file}, 2766@option{pipe}, 2767@option{console}, 2768@option{serial}, 2769@option{pty}, 2770@option{stdio}, 2771@option{braille}, 2772@option{tty}, 2773@option{parallel}, 2774@option{parport}, 2775@option{spicevmc}, 2776@option{spiceport}. 2777The specific backend will determine the applicable options. 2778 2779Use @code{-chardev help} to print all available chardev backend types. 2780 2781All devices must have an id, which can be any string up to 127 characters long. 2782It is used to uniquely identify this device in other command line directives. 2783 2784A character device may be used in multiplexing mode by multiple front-ends. 2785Specify @option{mux=on} to enable this mode. 2786A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2787backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2788If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2789create a multiplexer with your specified ID, and you can then configure multiple 2790front ends to use that chardev ID for their input/output. Up to four different 2791front ends can be connected to a single multiplexed chardev. (Without 2792multiplexing enabled, a chardev can only be used by a single front end.) 2793For instance you could use this to allow a single stdio chardev to be used by 2794two serial ports and the QEMU monitor: 2795 2796@example 2797-chardev stdio,mux=on,id=char0 \ 2798-mon chardev=char0,mode=readline \ 2799-serial chardev:char0 \ 2800-serial chardev:char0 2801@end example 2802 2803You can have more than one multiplexer in a system configuration; for instance 2804you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2805multiplexed between the QEMU monitor and a parallel port: 2806 2807@example 2808-chardev stdio,mux=on,id=char0 \ 2809-mon chardev=char0,mode=readline \ 2810-parallel chardev:char0 \ 2811-chardev tcp,...,mux=on,id=char1 \ 2812-serial chardev:char1 \ 2813-serial chardev:char1 2814@end example 2815 2816When you're using a multiplexed character device, some escape sequences are 2817interpreted in the input. @xref{mux_keys, Keys in the character backend 2818multiplexer}. 2819 2820Note that some other command line options may implicitly create multiplexed 2821character backends; for instance @option{-serial mon:stdio} creates a 2822multiplexed stdio backend connected to the serial port and the QEMU monitor, 2823and @option{-nographic} also multiplexes the console and the monitor to 2824stdio. 2825 2826There is currently no support for multiplexing in the other direction 2827(where a single QEMU front end takes input and output from multiple chardevs). 2828 2829Every backend supports the @option{logfile} option, which supplies the path 2830to a file to record all data transmitted via the backend. The @option{logappend} 2831option controls whether the log file will be truncated or appended to when 2832opened. 2833 2834@end table 2835 2836The available backends are: 2837 2838@table @option 2839@item -chardev null,id=@var{id} 2840A void device. This device will not emit any data, and will drop any data it 2841receives. The null backend does not take any options. 2842 2843@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}] 2844 2845Create a two-way stream socket, which can be either a TCP or a unix socket. A 2846unix socket will be created if @option{path} is specified. Behaviour is 2847undefined if TCP options are specified for a unix socket. 2848 2849@option{server} specifies that the socket shall be a listening socket. 2850 2851@option{nowait} specifies that QEMU should not block waiting for a client to 2852connect to a listening socket. 2853 2854@option{telnet} specifies that traffic on the socket should interpret telnet 2855escape sequences. 2856 2857@option{websocket} specifies that the socket uses WebSocket protocol for 2858communication. 2859 2860@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2861the remote end goes away. qemu will delay this many seconds and then attempt 2862to reconnect. Zero disables reconnecting, and is the default. 2863 2864@option{tls-creds} requests enablement of the TLS protocol for encryption, 2865and specifies the id of the TLS credentials to use for the handshake. The 2866credentials must be previously created with the @option{-object tls-creds} 2867argument. 2868 2869@option{tls-auth} provides the ID of the QAuthZ authorization object against 2870which the client's x509 distinguished name will be validated. This object is 2871only resolved at time of use, so can be deleted and recreated on the fly 2872while the chardev server is active. If missing, it will default to denying 2873access. 2874 2875TCP and unix socket options are given below: 2876 2877@table @option 2878 2879@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2880 2881@option{host} for a listening socket specifies the local address to be bound. 2882For a connecting socket species the remote host to connect to. @option{host} is 2883optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2884 2885@option{port} for a listening socket specifies the local port to be bound. For a 2886connecting socket specifies the port on the remote host to connect to. 2887@option{port} can be given as either a port number or a service name. 2888@option{port} is required. 2889 2890@option{to} is only relevant to listening sockets. If it is specified, and 2891@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2892to and including @option{to} until it succeeds. @option{to} must be specified 2893as a port number. 2894 2895@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2896If neither is specified the socket may use either protocol. 2897 2898@option{nodelay} disables the Nagle algorithm. 2899 2900@item unix options: path=@var{path} 2901 2902@option{path} specifies the local path of the unix socket. @option{path} is 2903required. 2904 2905@end table 2906 2907@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2908 2909Sends all traffic from the guest to a remote host over UDP. 2910 2911@option{host} specifies the remote host to connect to. If not specified it 2912defaults to @code{localhost}. 2913 2914@option{port} specifies the port on the remote host to connect to. @option{port} 2915is required. 2916 2917@option{localaddr} specifies the local address to bind to. If not specified it 2918defaults to @code{0.0.0.0}. 2919 2920@option{localport} specifies the local port to bind to. If not specified any 2921available local port will be used. 2922 2923@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2924If neither is specified the device may use either protocol. 2925 2926@item -chardev msmouse,id=@var{id} 2927 2928Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2929take any options. 2930 2931@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 2932 2933Connect to a QEMU text console. @option{vc} may optionally be given a specific 2934size. 2935 2936@option{width} and @option{height} specify the width and height respectively of 2937the console, in pixels. 2938 2939@option{cols} and @option{rows} specify that the console be sized to fit a text 2940console with the given dimensions. 2941 2942@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 2943 2944Create a ring buffer with fixed size @option{size}. 2945@var{size} must be a power of two and defaults to @code{64K}. 2946 2947@item -chardev file,id=@var{id},path=@var{path} 2948 2949Log all traffic received from the guest to a file. 2950 2951@option{path} specifies the path of the file to be opened. This file will be 2952created if it does not already exist, and overwritten if it does. @option{path} 2953is required. 2954 2955@item -chardev pipe,id=@var{id},path=@var{path} 2956 2957Create a two-way connection to the guest. The behaviour differs slightly between 2958Windows hosts and other hosts: 2959 2960On Windows, a single duplex pipe will be created at 2961@file{\\.pipe\@option{path}}. 2962 2963On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2964@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2965received by the guest. Data written by the guest can be read from 2966@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2967be present. 2968 2969@option{path} forms part of the pipe path as described above. @option{path} is 2970required. 2971 2972@item -chardev console,id=@var{id} 2973 2974Send traffic from the guest to QEMU's standard output. @option{console} does not 2975take any options. 2976 2977@option{console} is only available on Windows hosts. 2978 2979@item -chardev serial,id=@var{id},path=@option{path} 2980 2981Send traffic from the guest to a serial device on the host. 2982 2983On Unix hosts serial will actually accept any tty device, 2984not only serial lines. 2985 2986@option{path} specifies the name of the serial device to open. 2987 2988@item -chardev pty,id=@var{id} 2989 2990Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2991not take any options. 2992 2993@option{pty} is not available on Windows hosts. 2994 2995@item -chardev stdio,id=@var{id}[,signal=on|off] 2996Connect to standard input and standard output of the QEMU process. 2997 2998@option{signal} controls if signals are enabled on the terminal, that includes 2999exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3000default, use @option{signal=off} to disable it. 3001 3002@item -chardev braille,id=@var{id} 3003 3004Connect to a local BrlAPI server. @option{braille} does not take any options. 3005 3006@item -chardev tty,id=@var{id},path=@var{path} 3007 3008@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3009DragonFlyBSD hosts. It is an alias for @option{serial}. 3010 3011@option{path} specifies the path to the tty. @option{path} is required. 3012 3013@item -chardev parallel,id=@var{id},path=@var{path} 3014@itemx -chardev parport,id=@var{id},path=@var{path} 3015 3016@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3017 3018Connect to a local parallel port. 3019 3020@option{path} specifies the path to the parallel port device. @option{path} is 3021required. 3022 3023@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3024 3025@option{spicevmc} is only available when spice support is built in. 3026 3027@option{debug} debug level for spicevmc 3028 3029@option{name} name of spice channel to connect to 3030 3031Connect to a spice virtual machine channel, such as vdiport. 3032 3033@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3034 3035@option{spiceport} is only available when spice support is built in. 3036 3037@option{debug} debug level for spicevmc 3038 3039@option{name} name of spice port to connect to 3040 3041Connect to a spice port, allowing a Spice client to handle the traffic 3042identified by a name (preferably a fqdn). 3043ETEXI 3044 3045STEXI 3046@end table 3047ETEXI 3048DEFHEADING() 3049 3050DEFHEADING(Bluetooth(R) options:) 3051STEXI 3052@table @option 3053ETEXI 3054 3055DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3056 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3057 "-bt hci,host[:id]\n" \ 3058 " use host's HCI with the given name\n" \ 3059 "-bt hci[,vlan=n]\n" \ 3060 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3061 "-bt vhci[,vlan=n]\n" \ 3062 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3063 "-bt device:dev[,vlan=n]\n" \ 3064 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3065 QEMU_ARCH_ALL) 3066STEXI 3067@item -bt hci[...] 3068@findex -bt 3069Defines the function of the corresponding Bluetooth HCI. -bt options 3070are matched with the HCIs present in the chosen machine type. For 3071example when emulating a machine with only one HCI built into it, only 3072the first @code{-bt hci[...]} option is valid and defines the HCI's 3073logic. The Transport Layer is decided by the machine type. Currently 3074the machines @code{n800} and @code{n810} have one HCI and all other 3075machines have none. 3076 3077Note: This option and the whole bluetooth subsystem is considered as deprecated. 3078If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where 3079you describe your usecase. 3080 3081@anchor{bt-hcis} 3082The following three types are recognized: 3083 3084@table @option 3085@item -bt hci,null 3086(default) The corresponding Bluetooth HCI assumes no internal logic 3087and will not respond to any HCI commands or emit events. 3088 3089@item -bt hci,host[:@var{id}] 3090(@code{bluez} only) The corresponding HCI passes commands / events 3091to / from the physical HCI identified by the name @var{id} (default: 3092@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3093capable systems like Linux. 3094 3095@item -bt hci[,vlan=@var{n}] 3096Add a virtual, standard HCI that will participate in the Bluetooth 3097scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3098VLANs, devices inside a bluetooth network @var{n} can only communicate 3099with other devices in the same network (scatternet). 3100@end table 3101 3102@item -bt vhci[,vlan=@var{n}] 3103(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3104to the host bluetooth stack instead of to the emulated target. This 3105allows the host and target machines to participate in a common scatternet 3106and communicate. Requires the Linux @code{vhci} driver installed. Can 3107be used as following: 3108 3109@example 3110@value{qemu_system} [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3111@end example 3112 3113@item -bt device:@var{dev}[,vlan=@var{n}] 3114Emulate a bluetooth device @var{dev} and place it in network @var{n} 3115(default @code{0}). QEMU can only emulate one type of bluetooth devices 3116currently: 3117 3118@table @option 3119@item keyboard 3120Virtual wireless keyboard implementing the HIDP bluetooth profile. 3121@end table 3122ETEXI 3123 3124STEXI 3125@end table 3126ETEXI 3127DEFHEADING() 3128 3129#ifdef CONFIG_TPM 3130DEFHEADING(TPM device options:) 3131 3132DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3133 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3134 " use path to provide path to a character device; default is /dev/tpm0\n" 3135 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3136 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3137 "-tpmdev emulator,id=id,chardev=dev\n" 3138 " configure the TPM device using chardev backend\n", 3139 QEMU_ARCH_ALL) 3140STEXI 3141 3142The general form of a TPM device option is: 3143@table @option 3144 3145@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3146@findex -tpmdev 3147 3148The specific backend type will determine the applicable options. 3149The @code{-tpmdev} option creates the TPM backend and requires a 3150@code{-device} option that specifies the TPM frontend interface model. 3151 3152Use @code{-tpmdev help} to print all available TPM backend types. 3153 3154@end table 3155 3156The available backends are: 3157 3158@table @option 3159 3160@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3161 3162(Linux-host only) Enable access to the host's TPM using the passthrough 3163driver. 3164 3165@option{path} specifies the path to the host's TPM device, i.e., on 3166a Linux host this would be @code{/dev/tpm0}. 3167@option{path} is optional and by default @code{/dev/tpm0} is used. 3168 3169@option{cancel-path} specifies the path to the host TPM device's sysfs 3170entry allowing for cancellation of an ongoing TPM command. 3171@option{cancel-path} is optional and by default QEMU will search for the 3172sysfs entry to use. 3173 3174Some notes about using the host's TPM with the passthrough driver: 3175 3176The TPM device accessed by the passthrough driver must not be 3177used by any other application on the host. 3178 3179Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3180the VM's firmware (BIOS/UEFI) will not be able to initialize the 3181TPM again and may therefore not show a TPM-specific menu that would 3182otherwise allow the user to configure the TPM, e.g., allow the user to 3183enable/disable or activate/deactivate the TPM. 3184Further, if TPM ownership is released from within a VM then the host's TPM 3185will get disabled and deactivated. To enable and activate the 3186TPM again afterwards, the host has to be rebooted and the user is 3187required to enter the firmware's menu to enable and activate the TPM. 3188If the TPM is left disabled and/or deactivated most TPM commands will fail. 3189 3190To create a passthrough TPM use the following two options: 3191@example 3192-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3193@end example 3194Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3195@code{tpmdev=tpm0} in the device option. 3196 3197@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3198 3199(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3200chardev backend. 3201 3202@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3203 3204To create a TPM emulator backend device with chardev socket backend: 3205@example 3206 3207-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3208 3209@end example 3210 3211ETEXI 3212 3213STEXI 3214@end table 3215ETEXI 3216DEFHEADING() 3217 3218#endif 3219 3220DEFHEADING(Linux/Multiboot boot specific:) 3221STEXI 3222 3223When using these options, you can use a given Linux or Multiboot 3224kernel without installing it in the disk image. It can be useful 3225for easier testing of various kernels. 3226 3227@table @option 3228ETEXI 3229 3230DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3231 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3232STEXI 3233@item -kernel @var{bzImage} 3234@findex -kernel 3235Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3236or in multiboot format. 3237ETEXI 3238 3239DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3240 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3241STEXI 3242@item -append @var{cmdline} 3243@findex -append 3244Use @var{cmdline} as kernel command line 3245ETEXI 3246 3247DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3248 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3249STEXI 3250@item -initrd @var{file} 3251@findex -initrd 3252Use @var{file} as initial ram disk. 3253 3254@item -initrd "@var{file1} arg=foo,@var{file2}" 3255 3256This syntax is only available with multiboot. 3257 3258Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3259first module. 3260ETEXI 3261 3262DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3263 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3264STEXI 3265@item -dtb @var{file} 3266@findex -dtb 3267Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3268on boot. 3269ETEXI 3270 3271STEXI 3272@end table 3273ETEXI 3274DEFHEADING() 3275 3276DEFHEADING(Debug/Expert options:) 3277STEXI 3278@table @option 3279ETEXI 3280 3281DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3282 "-fw_cfg [name=]<name>,file=<file>\n" 3283 " add named fw_cfg entry with contents from file\n" 3284 "-fw_cfg [name=]<name>,string=<str>\n" 3285 " add named fw_cfg entry with contents from string\n", 3286 QEMU_ARCH_ALL) 3287STEXI 3288 3289@item -fw_cfg [name=]@var{name},file=@var{file} 3290@findex -fw_cfg 3291Add named fw_cfg entry with contents from file @var{file}. 3292 3293@item -fw_cfg [name=]@var{name},string=@var{str} 3294Add named fw_cfg entry with contents from string @var{str}. 3295 3296The terminating NUL character of the contents of @var{str} will not be 3297included as part of the fw_cfg item data. To insert contents with 3298embedded NUL characters, you have to use the @var{file} parameter. 3299 3300The fw_cfg entries are passed by QEMU through to the guest. 3301 3302Example: 3303@example 3304 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3305@end example 3306creates an fw_cfg entry named opt/com.mycompany/blob with contents 3307from ./my_blob.bin. 3308 3309ETEXI 3310 3311DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3312 "-serial dev redirect the serial port to char device 'dev'\n", 3313 QEMU_ARCH_ALL) 3314STEXI 3315@item -serial @var{dev} 3316@findex -serial 3317Redirect the virtual serial port to host character device 3318@var{dev}. The default device is @code{vc} in graphical mode and 3319@code{stdio} in non graphical mode. 3320 3321This option can be used several times to simulate up to 4 serial 3322ports. 3323 3324Use @code{-serial none} to disable all serial ports. 3325 3326Available character devices are: 3327@table @option 3328@item vc[:@var{W}x@var{H}] 3329Virtual console. Optionally, a width and height can be given in pixel with 3330@example 3331vc:800x600 3332@end example 3333It is also possible to specify width or height in characters: 3334@example 3335vc:80Cx24C 3336@end example 3337@item pty 3338[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3339@item none 3340No device is allocated. 3341@item null 3342void device 3343@item chardev:@var{id} 3344Use a named character device defined with the @code{-chardev} option. 3345@item /dev/XXX 3346[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3347parameters are set according to the emulated ones. 3348@item /dev/parport@var{N} 3349[Linux only, parallel port only] Use host parallel port 3350@var{N}. Currently SPP and EPP parallel port features can be used. 3351@item file:@var{filename} 3352Write output to @var{filename}. No character can be read. 3353@item stdio 3354[Unix only] standard input/output 3355@item pipe:@var{filename} 3356name pipe @var{filename} 3357@item COM@var{n} 3358[Windows only] Use host serial port @var{n} 3359@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3360This implements UDP Net Console. 3361When @var{remote_host} or @var{src_ip} are not specified 3362they default to @code{0.0.0.0}. 3363When not using a specified @var{src_port} a random port is automatically chosen. 3364 3365If you just want a simple readonly console you can use @code{netcat} or 3366@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3367@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3368will appear in the netconsole session. 3369 3370If you plan to send characters back via netconsole or you want to stop 3371and start QEMU a lot of times, you should have QEMU use the same 3372source port each time by using something like @code{-serial 3373udp::4555@@:4556} to QEMU. Another approach is to use a patched 3374version of netcat which can listen to a TCP port and send and receive 3375characters via udp. If you have a patched version of netcat which 3376activates telnet remote echo and single char transfer, then you can 3377use the following options to set up a netcat redirector to allow 3378telnet on port 5555 to access the QEMU port. 3379@table @code 3380@item QEMU Options: 3381-serial udp::4555@@:4556 3382@item netcat options: 3383-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3384@item telnet options: 3385localhost 5555 3386@end table 3387 3388@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3389The TCP Net Console has two modes of operation. It can send the serial 3390I/O to a location or wait for a connection from a location. By default 3391the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3392the @var{server} option QEMU will wait for a client socket application 3393to connect to the port before continuing, unless the @code{nowait} 3394option was specified. The @code{nodelay} option disables the Nagle buffering 3395algorithm. The @code{reconnect} option only applies if @var{noserver} is 3396set, if the connection goes down it will attempt to reconnect at the 3397given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3398one TCP connection at a time is accepted. You can use @code{telnet} to 3399connect to the corresponding character device. 3400@table @code 3401@item Example to send tcp console to 192.168.0.2 port 4444 3402-serial tcp:192.168.0.2:4444 3403@item Example to listen and wait on port 4444 for connection 3404-serial tcp::4444,server 3405@item Example to not wait and listen on ip 192.168.0.100 port 4444 3406-serial tcp:192.168.0.100:4444,server,nowait 3407@end table 3408 3409@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3410The telnet protocol is used instead of raw tcp sockets. The options 3411work the same as if you had specified @code{-serial tcp}. The 3412difference is that the port acts like a telnet server or client using 3413telnet option negotiation. This will also allow you to send the 3414MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3415sequence. Typically in unix telnet you do it with Control-] and then 3416type "send break" followed by pressing the enter key. 3417 3418@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3419The WebSocket protocol is used instead of raw tcp socket. The port acts as 3420a WebSocket server. Client mode is not supported. 3421 3422@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3423A unix domain socket is used instead of a tcp socket. The option works the 3424same as if you had specified @code{-serial tcp} except the unix domain socket 3425@var{path} is used for connections. 3426 3427@item mon:@var{dev_string} 3428This is a special option to allow the monitor to be multiplexed onto 3429another serial port. The monitor is accessed with key sequence of 3430@key{Control-a} and then pressing @key{c}. 3431@var{dev_string} should be any one of the serial devices specified 3432above. An example to multiplex the monitor onto a telnet server 3433listening on port 4444 would be: 3434@table @code 3435@item -serial mon:telnet::4444,server,nowait 3436@end table 3437When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3438QEMU any more but will be passed to the guest instead. 3439 3440@item braille 3441Braille device. This will use BrlAPI to display the braille output on a real 3442or fake device. 3443 3444@item msmouse 3445Three button serial mouse. Configure the guest to use Microsoft protocol. 3446@end table 3447ETEXI 3448 3449DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3450 "-parallel dev redirect the parallel port to char device 'dev'\n", 3451 QEMU_ARCH_ALL) 3452STEXI 3453@item -parallel @var{dev} 3454@findex -parallel 3455Redirect the virtual parallel port to host device @var{dev} (same 3456devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3457be used to use hardware devices connected on the corresponding host 3458parallel port. 3459 3460This option can be used several times to simulate up to 3 parallel 3461ports. 3462 3463Use @code{-parallel none} to disable all parallel ports. 3464ETEXI 3465 3466DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3467 "-monitor dev redirect the monitor to char device 'dev'\n", 3468 QEMU_ARCH_ALL) 3469STEXI 3470@item -monitor @var{dev} 3471@findex -monitor 3472Redirect the monitor to host device @var{dev} (same devices as the 3473serial port). 3474The default device is @code{vc} in graphical mode and @code{stdio} in 3475non graphical mode. 3476Use @code{-monitor none} to disable the default monitor. 3477ETEXI 3478DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3479 "-qmp dev like -monitor but opens in 'control' mode\n", 3480 QEMU_ARCH_ALL) 3481STEXI 3482@item -qmp @var{dev} 3483@findex -qmp 3484Like -monitor but opens in 'control' mode. 3485ETEXI 3486DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3487 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3488 QEMU_ARCH_ALL) 3489STEXI 3490@item -qmp-pretty @var{dev} 3491@findex -qmp-pretty 3492Like -qmp but uses pretty JSON formatting. 3493ETEXI 3494 3495DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3496 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3497STEXI 3498@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3499@findex -mon 3500Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3501easing human reading and debugging. 3502ETEXI 3503 3504DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3505 "-debugcon dev redirect the debug console to char device 'dev'\n", 3506 QEMU_ARCH_ALL) 3507STEXI 3508@item -debugcon @var{dev} 3509@findex -debugcon 3510Redirect the debug console to host device @var{dev} (same devices as the 3511serial port). The debug console is an I/O port which is typically port 35120xe9; writing to that I/O port sends output to this device. 3513The default device is @code{vc} in graphical mode and @code{stdio} in 3514non graphical mode. 3515ETEXI 3516 3517DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3518 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3519STEXI 3520@item -pidfile @var{file} 3521@findex -pidfile 3522Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3523from a script. 3524ETEXI 3525 3526DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3527 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3528STEXI 3529@item -singlestep 3530@findex -singlestep 3531Run the emulation in single step mode. 3532ETEXI 3533 3534DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3535 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3536 QEMU_ARCH_ALL) 3537STEXI 3538@item --preconfig 3539@findex --preconfig 3540Pause QEMU for interactive configuration before the machine is created, 3541which allows querying and configuring properties that will affect 3542machine initialization. Use QMP command 'x-exit-preconfig' to exit 3543the preconfig state and move to the next state (i.e. run guest if -S 3544isn't used or pause the second time if -S is used). This option is 3545experimental. 3546ETEXI 3547 3548DEF("S", 0, QEMU_OPTION_S, \ 3549 "-S freeze CPU at startup (use 'c' to start execution)\n", 3550 QEMU_ARCH_ALL) 3551STEXI 3552@item -S 3553@findex -S 3554Do not start CPU at startup (you must type 'c' in the monitor). 3555ETEXI 3556 3557DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3558 "-realtime [mlock=on|off]\n" 3559 " run qemu with realtime features\n" 3560 " mlock=on|off controls mlock support (default: on)\n", 3561 QEMU_ARCH_ALL) 3562STEXI 3563@item -realtime mlock=on|off 3564@findex -realtime 3565Run qemu with realtime features. 3566mlocking qemu and guest memory can be enabled via @option{mlock=on} 3567(enabled by default). 3568ETEXI 3569 3570DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3571 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3572 " run qemu with overcommit hints\n" 3573 " mem-lock=on|off controls memory lock support (default: off)\n" 3574 " cpu-pm=on|off controls cpu power management (default: off)\n", 3575 QEMU_ARCH_ALL) 3576STEXI 3577@item -overcommit mem-lock=on|off 3578@item -overcommit cpu-pm=on|off 3579@findex -overcommit 3580Run qemu with hints about host resource overcommit. The default is 3581to assume that host overcommits all resources. 3582 3583Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3584by default). This works when host memory is not overcommitted and reduces the 3585worst-case latency for guest. This is equivalent to @option{realtime}. 3586 3587Guest ability to manage power state of host cpus (increasing latency for other 3588processes on the same host cpu, but decreasing latency for guest) can be 3589enabled via @option{cpu-pm=on} (disabled by default). This works best when 3590host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3591utilization will be incorrect, not taking into account guest idle time. 3592ETEXI 3593 3594DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3595 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3596STEXI 3597@item -gdb @var{dev} 3598@findex -gdb 3599Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3600connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3601stdio are reasonable use case. The latter is allowing to start QEMU from 3602within gdb and establish the connection via a pipe: 3603@example 3604(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3605@end example 3606ETEXI 3607 3608DEF("s", 0, QEMU_OPTION_s, \ 3609 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3610 QEMU_ARCH_ALL) 3611STEXI 3612@item -s 3613@findex -s 3614Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3615(@pxref{gdb_usage}). 3616ETEXI 3617 3618DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3619 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3620 QEMU_ARCH_ALL) 3621STEXI 3622@item -d @var{item1}[,...] 3623@findex -d 3624Enable logging of specified items. Use '-d help' for a list of log items. 3625ETEXI 3626 3627DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3628 "-D logfile output log to logfile (default stderr)\n", 3629 QEMU_ARCH_ALL) 3630STEXI 3631@item -D @var{logfile} 3632@findex -D 3633Output log in @var{logfile} instead of to stderr 3634ETEXI 3635 3636DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3637 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3638 QEMU_ARCH_ALL) 3639STEXI 3640@item -dfilter @var{range1}[,...] 3641@findex -dfilter 3642Filter debug output to that relevant to a range of target addresses. The filter 3643spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3644@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3645addresses and sizes required. For example: 3646@example 3647 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3648@end example 3649Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3650the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3651block starting at 0xffffffc00005f000. 3652ETEXI 3653 3654DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3655 "-seed number seed the pseudo-random number generator\n", 3656 QEMU_ARCH_ALL) 3657STEXI 3658@item -seed @var{number} 3659@findex -seed 3660Force the guest to use a deterministic pseudo-random number generator, seeded 3661with @var{number}. This does not affect crypto routines within the host. 3662ETEXI 3663 3664DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3665 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3666 QEMU_ARCH_ALL) 3667STEXI 3668@item -L @var{path} 3669@findex -L 3670Set the directory for the BIOS, VGA BIOS and keymaps. 3671 3672To list all the data directories, use @code{-L help}. 3673ETEXI 3674 3675DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3676 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3677STEXI 3678@item -bios @var{file} 3679@findex -bios 3680Set the filename for the BIOS. 3681ETEXI 3682 3683DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3684 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3685STEXI 3686@item -enable-kvm 3687@findex -enable-kvm 3688Enable KVM full virtualization support. This option is only available 3689if KVM support is enabled when compiling. 3690ETEXI 3691 3692DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3693 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3694DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3695 "-xen-attach attach to existing xen domain\n" 3696 " libxl will use this when starting QEMU\n", 3697 QEMU_ARCH_ALL) 3698DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3699 "-xen-domid-restrict restrict set of available xen operations\n" 3700 " to specified domain id. (Does not affect\n" 3701 " xenpv machine type).\n", 3702 QEMU_ARCH_ALL) 3703STEXI 3704@item -xen-domid @var{id} 3705@findex -xen-domid 3706Specify xen guest domain @var{id} (XEN only). 3707@item -xen-attach 3708@findex -xen-attach 3709Attach to existing xen domain. 3710libxl will use this when starting QEMU (XEN only). 3711@findex -xen-domid-restrict 3712Restrict set of available xen operations to specified domain id (XEN only). 3713ETEXI 3714 3715DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3716 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3717STEXI 3718@item -no-reboot 3719@findex -no-reboot 3720Exit instead of rebooting. 3721ETEXI 3722 3723DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3724 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3725STEXI 3726@item -no-shutdown 3727@findex -no-shutdown 3728Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3729This allows for instance switching to monitor to commit changes to the 3730disk image. 3731ETEXI 3732 3733DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3734 "-loadvm [tag|id]\n" \ 3735 " start right away with a saved state (loadvm in monitor)\n", 3736 QEMU_ARCH_ALL) 3737STEXI 3738@item -loadvm @var{file} 3739@findex -loadvm 3740Start right away with a saved state (@code{loadvm} in monitor) 3741ETEXI 3742 3743#ifndef _WIN32 3744DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3745 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3746#endif 3747STEXI 3748@item -daemonize 3749@findex -daemonize 3750Daemonize the QEMU process after initialization. QEMU will not detach from 3751standard IO until it is ready to receive connections on any of its devices. 3752This option is a useful way for external programs to launch QEMU without having 3753to cope with initialization race conditions. 3754ETEXI 3755 3756DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3757 "-option-rom rom load a file, rom, into the option ROM space\n", 3758 QEMU_ARCH_ALL) 3759STEXI 3760@item -option-rom @var{file} 3761@findex -option-rom 3762Load the contents of @var{file} as an option ROM. 3763This option is useful to load things like EtherBoot. 3764ETEXI 3765 3766DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3767 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3768 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3769 QEMU_ARCH_ALL) 3770 3771STEXI 3772 3773@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3774@findex -rtc 3775Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3776UTC or local time, respectively. @code{localtime} is required for correct date in 3777MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3778format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3779 3780By default the RTC is driven by the host system time. This allows using of the 3781RTC as accurate reference clock inside the guest, specifically if the host 3782time is smoothly following an accurate external reference clock, e.g. via NTP. 3783If you want to isolate the guest time from the host, you can set @option{clock} 3784to @code{rt} instead, which provides a host monotonic clock if host support it. 3785To even prevent the RTC from progressing during suspension, you can set @option{clock} 3786to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3787icount mode in order to preserve determinism; however, note that in icount mode 3788the speed of the virtual clock is variable and can in general differ from the 3789host clock. 3790 3791Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3792specifically with Windows' ACPI HAL. This option will try to figure out how 3793many timer interrupts were not processed by the Windows guest and will 3794re-inject them. 3795ETEXI 3796 3797DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3798 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3799 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3800 " instruction, enable aligning the host and virtual clocks\n" \ 3801 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3802STEXI 3803@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3804@findex -icount 3805Enable virtual instruction counter. The virtual cpu will execute one 3806instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3807then the virtual cpu speed will be automatically adjusted to keep virtual 3808time within a few seconds of real time. 3809 3810When the virtual cpu is sleeping, the virtual time will advance at default 3811speed unless @option{sleep=on|off} is specified. 3812With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3813instantly whenever the virtual cpu goes to sleep mode and will not advance 3814if no timer is enabled. This behavior give deterministic execution times from 3815the guest point of view. 3816 3817Note that while this option can give deterministic behavior, it does not 3818provide cycle accurate emulation. Modern CPUs contain superscalar out of 3819order cores with complex cache hierarchies. The number of instructions 3820executed often has little or no correlation with actual performance. 3821 3822@option{align=on} will activate the delay algorithm which will try 3823to synchronise the host clock and the virtual clock. The goal is to 3824have a guest running at the real frequency imposed by the shift option. 3825Whenever the guest clock is behind the host clock and if 3826@option{align=on} is specified then we print a message to the user 3827to inform about the delay. 3828Currently this option does not work when @option{shift} is @code{auto}. 3829Note: The sync algorithm will work for those shift values for which 3830the guest clock runs ahead of the host clock. Typically this happens 3831when the shift value is high (how high depends on the host machine). 3832 3833When @option{rr} option is specified deterministic record/replay is enabled. 3834Replay log is written into @var{filename} file in record mode and 3835read from this file in replay mode. 3836 3837Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3838at the start of execution recording. In replay mode this option is used 3839to load the initial VM state. 3840ETEXI 3841 3842DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3843 "-watchdog model\n" \ 3844 " enable virtual hardware watchdog [default=none]\n", 3845 QEMU_ARCH_ALL) 3846STEXI 3847@item -watchdog @var{model} 3848@findex -watchdog 3849Create a virtual hardware watchdog device. Once enabled (by a guest 3850action), the watchdog must be periodically polled by an agent inside 3851the guest or else the guest will be restarted. Choose a model for 3852which your guest has drivers. 3853 3854The @var{model} is the model of hardware watchdog to emulate. Use 3855@code{-watchdog help} to list available hardware models. Only one 3856watchdog can be enabled for a guest. 3857 3858The following models may be available: 3859@table @option 3860@item ib700 3861iBASE 700 is a very simple ISA watchdog with a single timer. 3862@item i6300esb 3863Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3864dual-timer watchdog. 3865@item diag288 3866A virtual watchdog for s390x backed by the diagnose 288 hypercall 3867(currently KVM only). 3868@end table 3869ETEXI 3870 3871DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3872 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3873 " action when watchdog fires [default=reset]\n", 3874 QEMU_ARCH_ALL) 3875STEXI 3876@item -watchdog-action @var{action} 3877@findex -watchdog-action 3878 3879The @var{action} controls what QEMU will do when the watchdog timer 3880expires. 3881The default is 3882@code{reset} (forcefully reset the guest). 3883Other possible actions are: 3884@code{shutdown} (attempt to gracefully shutdown the guest), 3885@code{poweroff} (forcefully poweroff the guest), 3886@code{inject-nmi} (inject a NMI into the guest), 3887@code{pause} (pause the guest), 3888@code{debug} (print a debug message and continue), or 3889@code{none} (do nothing). 3890 3891Note that the @code{shutdown} action requires that the guest responds 3892to ACPI signals, which it may not be able to do in the sort of 3893situations where the watchdog would have expired, and thus 3894@code{-watchdog-action shutdown} is not recommended for production use. 3895 3896Examples: 3897 3898@table @code 3899@item -watchdog i6300esb -watchdog-action pause 3900@itemx -watchdog ib700 3901@end table 3902ETEXI 3903 3904DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3905 "-echr chr set terminal escape character instead of ctrl-a\n", 3906 QEMU_ARCH_ALL) 3907STEXI 3908 3909@item -echr @var{numeric_ascii_value} 3910@findex -echr 3911Change the escape character used for switching to the monitor when using 3912monitor and serial sharing. The default is @code{0x01} when using the 3913@code{-nographic} option. @code{0x01} is equal to pressing 3914@code{Control-a}. You can select a different character from the ascii 3915control keys where 1 through 26 map to Control-a through Control-z. For 3916instance you could use the either of the following to change the escape 3917character to Control-t. 3918@table @code 3919@item -echr 0x14 3920@itemx -echr 20 3921@end table 3922ETEXI 3923 3924DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3925 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3926STEXI 3927@item -show-cursor 3928@findex -show-cursor 3929Show cursor. 3930ETEXI 3931 3932DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3933 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3934STEXI 3935@item -tb-size @var{n} 3936@findex -tb-size 3937Set TB size. 3938ETEXI 3939 3940DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3941 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3942 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3943 "-incoming unix:socketpath\n" \ 3944 " prepare for incoming migration, listen on\n" \ 3945 " specified protocol and socket address\n" \ 3946 "-incoming fd:fd\n" \ 3947 "-incoming exec:cmdline\n" \ 3948 " accept incoming migration on given file descriptor\n" \ 3949 " or from given external command\n" \ 3950 "-incoming defer\n" \ 3951 " wait for the URI to be specified via migrate_incoming\n", 3952 QEMU_ARCH_ALL) 3953STEXI 3954@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3955@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3956@findex -incoming 3957Prepare for incoming migration, listen on a given tcp port. 3958 3959@item -incoming unix:@var{socketpath} 3960Prepare for incoming migration, listen on a given unix socket. 3961 3962@item -incoming fd:@var{fd} 3963Accept incoming migration from a given filedescriptor. 3964 3965@item -incoming exec:@var{cmdline} 3966Accept incoming migration as an output from specified external command. 3967 3968@item -incoming defer 3969Wait for the URI to be specified via migrate_incoming. The monitor can 3970be used to change settings (such as migration parameters) prior to issuing 3971the migrate_incoming to allow the migration to begin. 3972ETEXI 3973 3974DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3975 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3976STEXI 3977@item -only-migratable 3978@findex -only-migratable 3979Only allow migratable devices. Devices will not be allowed to enter an 3980unmigratable state. 3981ETEXI 3982 3983DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3984 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3985STEXI 3986@item -nodefaults 3987@findex -nodefaults 3988Don't create default devices. Normally, QEMU sets the default devices like serial 3989port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3990CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3991default devices. 3992ETEXI 3993 3994#ifndef _WIN32 3995DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3996 "-chroot dir chroot to dir just before starting the VM\n", 3997 QEMU_ARCH_ALL) 3998#endif 3999STEXI 4000@item -chroot @var{dir} 4001@findex -chroot 4002Immediately before starting guest execution, chroot to the specified 4003directory. Especially useful in combination with -runas. 4004ETEXI 4005 4006#ifndef _WIN32 4007DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4008 "-runas user change to user id user just before starting the VM\n" \ 4009 " user can be numeric uid:gid instead\n", 4010 QEMU_ARCH_ALL) 4011#endif 4012STEXI 4013@item -runas @var{user} 4014@findex -runas 4015Immediately before starting guest execution, drop root privileges, switching 4016to the specified user. 4017ETEXI 4018 4019DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4020 "-prom-env variable=value\n" 4021 " set OpenBIOS nvram variables\n", 4022 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4023STEXI 4024@item -prom-env @var{variable}=@var{value} 4025@findex -prom-env 4026Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4027ETEXI 4028DEF("semihosting", 0, QEMU_OPTION_semihosting, 4029 "-semihosting semihosting mode\n", 4030 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4031 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4032STEXI 4033@item -semihosting 4034@findex -semihosting 4035Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4036ETEXI 4037DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4038 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4039 " semihosting configuration\n", 4040QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4041QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4042STEXI 4043@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4044@findex -semihosting-config 4045Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4046@table @option 4047@item target=@code{native|gdb|auto} 4048Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4049or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4050during debug sessions and @code{native} otherwise. 4051@item chardev=@var{str1} 4052Send the output to a chardev backend output for native or auto output when not in gdb 4053@item arg=@var{str1},arg=@var{str2},... 4054Allows the user to pass input arguments, and can be used multiple times to build 4055up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4056command line is still supported for backward compatibility. If both the 4057@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4058specified, the former is passed to semihosting as it always takes precedence. 4059@end table 4060ETEXI 4061DEF("old-param", 0, QEMU_OPTION_old_param, 4062 "-old-param old param mode\n", QEMU_ARCH_ARM) 4063STEXI 4064@item -old-param 4065@findex -old-param (ARM) 4066Old param mode (ARM only). 4067ETEXI 4068 4069DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4070 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4071 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4072 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4073 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4074 " by the kernel, but typically no longer used by modern\n" \ 4075 " C library implementations.\n" \ 4076 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4077 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4078 " The value 'children' will deny set*uid|gid system calls for\n" \ 4079 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4080 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4081 " blacklisting *fork and execve\n" \ 4082 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4083 QEMU_ARCH_ALL) 4084STEXI 4085@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4086@findex -sandbox 4087Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4088disable it. The default is 'off'. 4089@table @option 4090@item obsolete=@var{string} 4091Enable Obsolete system calls 4092@item elevateprivileges=@var{string} 4093Disable set*uid|gid system calls 4094@item spawn=@var{string} 4095Disable *fork and execve 4096@item resourcecontrol=@var{string} 4097Disable process affinity and schedular priority 4098@end table 4099ETEXI 4100 4101DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4102 "-readconfig <file>\n", QEMU_ARCH_ALL) 4103STEXI 4104@item -readconfig @var{file} 4105@findex -readconfig 4106Read device configuration from @var{file}. This approach is useful when you want to spawn 4107QEMU process with many command line options but you don't want to exceed the command line 4108character limit. 4109ETEXI 4110DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4111 "-writeconfig <file>\n" 4112 " read/write config file\n", QEMU_ARCH_ALL) 4113STEXI 4114@item -writeconfig @var{file} 4115@findex -writeconfig 4116Write device configuration to @var{file}. The @var{file} can be either filename to save 4117command line and device configuration into file or dash @code{-}) character to print the 4118output to stdout. This can be later used as input file for @code{-readconfig} option. 4119ETEXI 4120 4121DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4122 "-no-user-config\n" 4123 " do not load default user-provided config files at startup\n", 4124 QEMU_ARCH_ALL) 4125STEXI 4126@item -no-user-config 4127@findex -no-user-config 4128The @code{-no-user-config} option makes QEMU not load any of the user-provided 4129config files on @var{sysconfdir}. 4130ETEXI 4131 4132DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4133 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4134 " specify tracing options\n", 4135 QEMU_ARCH_ALL) 4136STEXI 4137HXCOMM This line is not accurate, as some sub-options are backend-specific but 4138HXCOMM HX does not support conditional compilation of text. 4139@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4140@findex -trace 4141@include qemu-option-trace.texi 4142ETEXI 4143 4144HXCOMM Internal use 4145DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4146DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4147 4148#ifdef __linux__ 4149DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4150 "-enable-fips enable FIPS 140-2 compliance\n", 4151 QEMU_ARCH_ALL) 4152#endif 4153STEXI 4154@item -enable-fips 4155@findex -enable-fips 4156Enable FIPS 140-2 compliance mode. 4157ETEXI 4158 4159HXCOMM Deprecated by -machine accel=tcg property 4160DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4161 4162DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4163 "-msg timestamp[=on|off]\n" 4164 " change the format of messages\n" 4165 " on|off controls leading timestamps (default:on)\n", 4166 QEMU_ARCH_ALL) 4167STEXI 4168@item -msg timestamp[=on|off] 4169@findex -msg 4170prepend a timestamp to each log message.(default:on) 4171ETEXI 4172 4173DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4174 "-dump-vmstate <file>\n" 4175 " Output vmstate information in JSON format to file.\n" 4176 " Use the scripts/vmstate-static-checker.py file to\n" 4177 " check for possible regressions in migration code\n" 4178 " by comparing two such vmstate dumps.\n", 4179 QEMU_ARCH_ALL) 4180STEXI 4181@item -dump-vmstate @var{file} 4182@findex -dump-vmstate 4183Dump json-encoded vmstate information for current machine type to file 4184in @var{file} 4185ETEXI 4186 4187DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4188 "-enable-sync-profile\n" 4189 " enable synchronization profiling\n", 4190 QEMU_ARCH_ALL) 4191STEXI 4192@item -enable-sync-profile 4193@findex -enable-sync-profile 4194Enable synchronization profiling. 4195ETEXI 4196 4197STEXI 4198@end table 4199ETEXI 4200DEFHEADING() 4201 4202DEFHEADING(Generic object creation:) 4203STEXI 4204@table @option 4205ETEXI 4206 4207DEF("object", HAS_ARG, QEMU_OPTION_object, 4208 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4209 " create a new object of type TYPENAME setting properties\n" 4210 " in the order they are specified. Note that the 'id'\n" 4211 " property must be set. These objects are placed in the\n" 4212 " '/objects' path.\n", 4213 QEMU_ARCH_ALL) 4214STEXI 4215@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4216@findex -object 4217Create a new object of type @var{typename} setting properties 4218in the order they are specified. Note that the 'id' 4219property must be set. These objects are placed in the 4220'/objects' path. 4221 4222@table @option 4223 4224@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} 4225 4226Creates a memory file backend object, which can be used to back 4227the guest RAM with huge pages. 4228 4229The @option{id} parameter is a unique ID that will be used to reference this 4230memory region when configuring the @option{-numa} argument. 4231 4232The @option{size} option provides the size of the memory region, and accepts 4233common suffixes, eg @option{500M}. 4234 4235The @option{mem-path} provides the path to either a shared memory or huge page 4236filesystem mount. 4237 4238The @option{share} boolean option determines whether the memory 4239region is marked as private to QEMU, or shared. The latter allows 4240a co-operating external process to access the QEMU memory region. 4241 4242The @option{share} is also required for pvrdma devices due to 4243limitations in the RDMA API provided by Linux. 4244 4245Setting share=on might affect the ability to configure NUMA 4246bindings for the memory backend under some circumstances, see 4247Documentation/vm/numa_memory_policy.txt on the Linux kernel 4248source tree for additional details. 4249 4250Setting the @option{discard-data} boolean option to @var{on} 4251indicates that file contents can be destroyed when QEMU exits, 4252to avoid unnecessarily flushing data to the backing file. Note 4253that @option{discard-data} is only an optimization, and QEMU 4254might not discard file contents if it aborts unexpectedly or is 4255terminated using SIGKILL. 4256 4257The @option{merge} boolean option enables memory merge, also known as 4258MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4259memory deduplication. 4260 4261Setting the @option{dump} boolean option to @var{off} excludes the memory from 4262core dumps. This feature is also known as MADV_DONTDUMP. 4263 4264The @option{prealloc} boolean option enables memory preallocation. 4265 4266The @option{host-nodes} option binds the memory range to a list of NUMA host 4267nodes. 4268 4269The @option{policy} option sets the NUMA policy to one of the following values: 4270 4271@table @option 4272@item @var{default} 4273default host policy 4274 4275@item @var{preferred} 4276prefer the given host node list for allocation 4277 4278@item @var{bind} 4279restrict memory allocation to the given host node list 4280 4281@item @var{interleave} 4282interleave memory allocations across the given host node list 4283@end table 4284 4285The @option{align} option specifies the base address alignment when 4286QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4287@option{2M}. Some backend store specified by @option{mem-path} 4288requires an alignment different than the default one used by QEMU, eg 4289the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4290such cases, users can specify the required alignment via this option. 4291 4292The @option{pmem} option specifies whether the backing file specified 4293by @option{mem-path} is in host persistent memory that can be accessed 4294using the SNIA NVM programming model (e.g. Intel NVDIMM). 4295If @option{pmem} is set to 'on', QEMU will take necessary operations to 4296guarantee the persistence of its own writes to @option{mem-path} 4297(e.g. in vNVDIMM label emulation and live migration). 4298Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4299file metadata is in sync for @option{mem-path} in case of host crash 4300or a power failure. MAP_SYNC requires support from both the host kernel 4301(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4302with DAX option. 4303 4304@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} 4305 4306Creates a memory backend object, which can be used to back the guest RAM. 4307Memory backend objects offer more control than the @option{-m} option that is 4308traditionally used to define guest RAM. Please refer to 4309@option{memory-backend-file} for a description of the options. 4310 4311@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} 4312 4313Creates an anonymous memory file backend object, which allows QEMU to 4314share the memory with an external process (e.g. when using 4315vhost-user). The memory is allocated with memfd and optional 4316sealing. (Linux only) 4317 4318The @option{seal} option creates a sealed-file, that will block 4319further resizing the memory ('on' by default). 4320 4321The @option{hugetlb} option specify the file to be created resides in 4322the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4323the @option{hugetlb} option, the @option{hugetlbsize} option specify 4324the hugetlb page size on systems that support multiple hugetlb page 4325sizes (it must be a power of 2 value supported by the system). 4326 4327In some versions of Linux, the @option{hugetlb} option is incompatible 4328with the @option{seal} option (requires at least Linux 4.16). 4329 4330Please refer to @option{memory-backend-file} for a description of the 4331other options. 4332 4333The @option{share} boolean option is @var{on} by default with memfd. 4334 4335@item -object rng-builtin,id=@var{id} 4336 4337Creates a random number generator backend which obtains entropy from 4338QEMU builtin functions. The @option{id} parameter is a unique ID that 4339will be used to reference this entropy backend from the @option{virtio-rng} 4340device. By default, the @option{virtio-rng} device uses this RNG backend. 4341 4342@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4343 4344Creates a random number generator backend which obtains entropy from 4345a device on the host. The @option{id} parameter is a unique ID that 4346will be used to reference this entropy backend from the @option{virtio-rng} 4347device. The @option{filename} parameter specifies which file to obtain 4348entropy from and if omitted defaults to @option{/dev/urandom}. 4349 4350@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4351 4352Creates a random number generator backend which obtains entropy from 4353an external daemon running on the host. The @option{id} parameter is 4354a unique ID that will be used to reference this entropy backend from 4355the @option{virtio-rng} device. The @option{chardev} parameter is 4356the unique ID of a character device backend that provides the connection 4357to the RNG daemon. 4358 4359@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4360 4361Creates a TLS anonymous credentials object, which can be used to provide 4362TLS support on network backends. The @option{id} parameter is a unique 4363ID which network backends will use to access the credentials. The 4364@option{endpoint} is either @option{server} or @option{client} depending 4365on whether the QEMU network backend that uses the credentials will be 4366acting as a client or as a server. If @option{verify-peer} is enabled 4367(the default) then once the handshake is completed, the peer credentials 4368will be verified, though this is a no-op for anonymous credentials. 4369 4370The @var{dir} parameter tells QEMU where to find the credential 4371files. For server endpoints, this directory may contain a file 4372@var{dh-params.pem} providing diffie-hellman parameters to use 4373for the TLS server. If the file is missing, QEMU will generate 4374a set of DH parameters at startup. This is a computationally 4375expensive operation that consumes random pool entropy, so it is 4376recommended that a persistent set of parameters be generated 4377upfront and saved. 4378 4379@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4380 4381Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4382TLS support on network backends. The @option{id} parameter is a unique 4383ID which network backends will use to access the credentials. The 4384@option{endpoint} is either @option{server} or @option{client} depending 4385on whether the QEMU network backend that uses the credentials will be 4386acting as a client or as a server. For clients only, @option{username} 4387is the username which will be sent to the server. If omitted 4388it defaults to ``qemu''. 4389 4390The @var{dir} parameter tells QEMU where to find the keys file. 4391It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4392pairs. This file can most easily be created using the GnuTLS 4393@code{psktool} program. 4394 4395For server endpoints, @var{dir} may also contain a file 4396@var{dh-params.pem} providing diffie-hellman parameters to use 4397for the TLS server. If the file is missing, QEMU will generate 4398a set of DH parameters at startup. This is a computationally 4399expensive operation that consumes random pool entropy, so it is 4400recommended that a persistent set of parameters be generated 4401up front and saved. 4402 4403@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} 4404 4405Creates a TLS anonymous credentials object, which can be used to provide 4406TLS support on network backends. The @option{id} parameter is a unique 4407ID which network backends will use to access the credentials. The 4408@option{endpoint} is either @option{server} or @option{client} depending 4409on whether the QEMU network backend that uses the credentials will be 4410acting as a client or as a server. If @option{verify-peer} is enabled 4411(the default) then once the handshake is completed, the peer credentials 4412will be verified. With x509 certificates, this implies that the clients 4413must be provided with valid client certificates too. 4414 4415The @var{dir} parameter tells QEMU where to find the credential 4416files. For server endpoints, this directory may contain a file 4417@var{dh-params.pem} providing diffie-hellman parameters to use 4418for the TLS server. If the file is missing, QEMU will generate 4419a set of DH parameters at startup. This is a computationally 4420expensive operation that consumes random pool entropy, so it is 4421recommended that a persistent set of parameters be generated 4422upfront and saved. 4423 4424For x509 certificate credentials the directory will contain further files 4425providing the x509 certificates. The certificates must be stored 4426in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4427@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4428@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4429 4430For the @var{server-key.pem} and @var{client-key.pem} files which 4431contain sensitive private keys, it is possible to use an encrypted 4432version by providing the @var{passwordid} parameter. This provides 4433the ID of a previously created @code{secret} object containing the 4434password for decryption. 4435 4436The @var{priority} parameter allows to override the global default 4437priority used by gnutls. This can be useful if the system administrator 4438needs to use a weaker set of crypto priorities for QEMU without 4439potentially forcing the weakness onto all applications. Or conversely 4440if one wants wants a stronger default for QEMU than for all other 4441applications, they can do this through this parameter. Its format is 4442a gnutls priority string as described at 4443@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4444 4445@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4446 4447Interval @var{t} can't be 0, this filter batches the packet delivery: all 4448packets arriving in a given interval on netdev @var{netdevid} are delayed 4449until the end of the interval. Interval is in microseconds. 4450@option{status} is optional that indicate whether the netfilter is 4451on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4452 4453queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4454 4455@option{all}: the filter is attached both to the receive and the transmit 4456 queue of the netdev (default). 4457 4458@option{rx}: the filter is attached to the receive queue of the netdev, 4459 where it will receive packets sent to the netdev. 4460 4461@option{tx}: the filter is attached to the transmit queue of the netdev, 4462 where it will receive packets sent by the netdev. 4463 4464@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4465 4466filter-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. 4467 4468@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4469 4470filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4471@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4472filter-redirector will redirect packet with vnet_hdr_len. 4473Create a filter-redirector we need to differ outdev id from indev id, id can not 4474be the same. we can just use indev or outdev, but at least one of indev or outdev 4475need to be specified. 4476 4477@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4478 4479Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4480secondary from primary to keep secondary tcp connection,and rewrite 4481tcp packet to primary from secondary make tcp packet can be handled by 4482client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4483 4484usage: 4485colo secondary: 4486-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4487-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4488-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4489 4490@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4491 4492Dump the network traffic on netdev @var{dev} to the file specified by 4493@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4494The file format is libpcap, so it can be analyzed with tools such as tcpdump 4495or Wireshark. 4496 4497@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}] 4498 4499Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4500secondary packet. If the packets are same, we will output primary 4501packet to outdev@var{chardevid}, else we will notify colo-frame 4502do checkpoint and send primary packet to outdev@var{chardevid}. 4503In order to improve efficiency, we need to put the task of comparison 4504in another thread. If it has the vnet_hdr_support flag, colo compare 4505will send/recv packet with vnet_hdr_len. 4506If you want to use Xen COLO, will need the notify_dev to notify Xen 4507colo-frame to do checkpoint. 4508 4509we must use it with the help of filter-mirror and filter-redirector. 4510 4511@example 4512 4513KVM COLO 4514 4515primary: 4516-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4517-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4518-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4519-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4520-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4521-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4522-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4523-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4524-object iothread,id=iothread1 4525-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4526-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4527-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4528-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4529 4530secondary: 4531-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4532-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4533-chardev socket,id=red0,host=3.3.3.3,port=9003 4534-chardev socket,id=red1,host=3.3.3.3,port=9004 4535-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4536-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4537 4538 4539Xen COLO 4540 4541primary: 4542-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4543-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4544-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4545-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4546-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4547-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4548-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4549-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4550-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4551-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4552-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4553-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4554-object iothread,id=iothread1 4555-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4556 4557secondary: 4558-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4559-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4560-chardev socket,id=red0,host=3.3.3.3,port=9003 4561-chardev socket,id=red1,host=3.3.3.3,port=9004 4562-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4563-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4564 4565@end example 4566 4567If you want to know the detail of above command line, you can read 4568the colo-compare git log. 4569 4570@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4571 4572Creates a cryptodev backend which executes crypto opreation from 4573the QEMU cipher APIS. The @var{id} parameter is 4574a unique ID that will be used to reference this cryptodev backend from 4575the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4576which specify the queue number of cryptodev backend, the default of 4577@var{queues} is 1. 4578 4579@example 4580 4581 # @value{qemu_system} \ 4582 [...] \ 4583 -object cryptodev-backend-builtin,id=cryptodev0 \ 4584 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4585 [...] 4586@end example 4587 4588@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4589 4590Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4591The @var{id} parameter is a unique ID that will be used to reference this 4592cryptodev backend from the @option{virtio-crypto} device. 4593The chardev should be a unix domain socket backed one. The vhost-user uses 4594a specifically defined protocol to pass vhost ioctl replacement messages 4595to an application on the other end of the socket. 4596The @var{queues} parameter is optional, which specify the queue number 4597of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4598 4599@example 4600 4601 # @value{qemu_system} \ 4602 [...] \ 4603 -chardev socket,id=chardev0,path=/path/to/socket \ 4604 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4605 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4606 [...] 4607@end example 4608 4609@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4610@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4611 4612Defines a secret to store a password, encryption key, or some other sensitive 4613data. The sensitive data can either be passed directly via the @var{data} 4614parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4615parameter is insecure unless the sensitive data is encrypted. 4616 4617The sensitive data can be provided in raw format (the default), or base64. 4618When encoded as JSON, the raw format only supports valid UTF-8 characters, 4619so base64 is recommended for sending binary data. QEMU will convert from 4620which ever format is provided to the format it needs internally. eg, an 4621RBD password can be provided in raw format, even though it will be base64 4622encoded when passed onto the RBD sever. 4623 4624For added protection, it is possible to encrypt the data associated with 4625a secret using the AES-256-CBC cipher. Use of encryption is indicated 4626by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4627parameter provides the ID of a previously defined secret that contains 4628the AES-256 decryption key. This key should be 32-bytes long and be 4629base64 encoded. The @var{iv} parameter provides the random initialization 4630vector used for encryption of this particular secret and should be a 4631base64 encrypted string of the 16-byte IV. 4632 4633The simplest (insecure) usage is to provide the secret inline 4634 4635@example 4636 4637 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4638 4639@end example 4640 4641The simplest secure usage is to provide the secret via a file 4642 4643 # printf "letmein" > mypasswd.txt 4644 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4645 4646For greater security, AES-256-CBC should be used. To illustrate usage, 4647consider the openssl command line tool which can encrypt the data. Note 4648that when encrypting, the plaintext must be padded to the cipher block 4649size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4650 4651First a master key needs to be created in base64 encoding: 4652 4653@example 4654 # openssl rand -base64 32 > key.b64 4655 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4656@end example 4657 4658Each secret to be encrypted needs to have a random initialization vector 4659generated. These do not need to be kept secret 4660 4661@example 4662 # openssl rand -base64 16 > iv.b64 4663 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4664@end example 4665 4666The secret to be defined can now be encrypted, in this case we're 4667telling openssl to base64 encode the result, but it could be left 4668as raw bytes if desired. 4669 4670@example 4671 # SECRET=$(printf "letmein" | 4672 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4673@end example 4674 4675When launching QEMU, create a master secret pointing to @code{key.b64} 4676and specify that to be used to decrypt the user password. Pass the 4677contents of @code{iv.b64} to the second secret 4678 4679@example 4680 # @value{qemu_system} \ 4681 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4682 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4683 data=$SECRET,iv=$(<iv.b64) 4684@end example 4685 4686@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}] 4687 4688Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4689to provide the guest memory encryption support on AMD processors. 4690 4691When memory encryption is enabled, one of the physical address bit (aka the 4692C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4693is used to provide the C-bit position. The C-bit position is Host family dependent 4694hence user must provide this value. On EPYC, the value should be 47. 4695 4696When memory encryption is enabled, we loose certain bits in physical address space. 4697The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4698physical address space. Similar to C-bit, the value is Host family dependent. 4699On EPYC, the value should be 5. 4700 4701The @option{sev-device} provides the device file to use for communicating with 4702the SEV firmware running inside AMD Secure Processor. The default device is 4703'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4704created by CCP driver. 4705 4706The @option{policy} provides the guest policy to be enforced by the SEV firmware 4707and restrict what configuration and operational commands can be performed on this 4708guest by the hypervisor. The policy should be provided by the guest owner and is 4709bound to the guest and cannot be changed throughout the lifetime of the guest. 4710The default is 0. 4711 4712If guest @option{policy} allows sharing the key with another SEV guest then 4713@option{handle} can be use to provide handle of the guest from which to share 4714the key. 4715 4716The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4717Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4718are used for establishing a cryptographic session with the guest owner to 4719negotiate keys used for attestation. The file must be encoded in base64. 4720 4721e.g to launch a SEV guest 4722@example 4723 # @value{qemu_system_x86} \ 4724 ...... 4725 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4726 -machine ...,memory-encryption=sev0 4727 ..... 4728 4729@end example 4730 4731 4732@item -object authz-simple,id=@var{id},identity=@var{string} 4733 4734Create an authorization object that will control access to network services. 4735 4736The @option{identity} parameter is identifies the user and its format 4737depends on the network service that authorization object is associated 4738with. For authorizing based on TLS x509 certificates, the identity must 4739be the x509 distinguished name. Note that care must be taken to escape 4740any commas in the distinguished name. 4741 4742An example authorization object to validate a x509 distinguished name 4743would look like: 4744@example 4745 # @value{qemu_system} \ 4746 ... 4747 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4748 ... 4749@end example 4750 4751Note the use of quotes due to the x509 distinguished name containing 4752whitespace, and escaping of ','. 4753 4754@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4755 4756Create an authorization object that will control access to network services. 4757 4758The @option{filename} parameter is the fully qualified path to a file 4759containing the access control list rules in JSON format. 4760 4761An example set of rules that match against SASL usernames might look 4762like: 4763 4764@example 4765 @{ 4766 "rules": [ 4767 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4768 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4769 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4770 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4771 ], 4772 "policy": "deny" 4773 @} 4774@end example 4775 4776When checking access the object will iterate over all the rules and 4777the first rule to match will have its @option{policy} value returned 4778as the result. If no rules match, then the default @option{policy} 4779value is returned. 4780 4781The rules can either be an exact string match, or they can use the 4782simple UNIX glob pattern matching to allow wildcards to be used. 4783 4784If @option{refresh} is set to true the file will be monitored 4785and automatically reloaded whenever its content changes. 4786 4787As with the @code{authz-simple} object, the format of the identity 4788strings being matched depends on the network service, but is usually 4789a TLS x509 distinguished name, or a SASL username. 4790 4791An example authorization object to validate a SASL username 4792would look like: 4793@example 4794 # @value{qemu_system} \ 4795 ... 4796 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4797 ... 4798@end example 4799 4800@item -object authz-pam,id=@var{id},service=@var{string} 4801 4802Create an authorization object that will control access to network services. 4803 4804The @option{service} parameter provides the name of a PAM service to use 4805for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4806exist to provide the configuration for the @code{account} subsystem. 4807 4808An example authorization object to validate a TLS x509 distinguished 4809name would look like: 4810 4811@example 4812 # @value{qemu_system} \ 4813 ... 4814 -object authz-pam,id=auth0,service=qemu-vnc 4815 ... 4816@end example 4817 4818There would then be a corresponding config file for PAM at 4819@code{/etc/pam.d/qemu-vnc} that contains: 4820 4821@example 4822account requisite pam_listfile.so item=user sense=allow \ 4823 file=/etc/qemu/vnc.allow 4824@end example 4825 4826Finally the @code{/etc/qemu/vnc.allow} file would contain 4827the list of x509 distingished names that are permitted 4828access 4829 4830@example 4831CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4832@end example 4833 4834 4835@end table 4836 4837ETEXI 4838 4839 4840HXCOMM This is the last statement. Insert new options before this line! 4841STEXI 4842@end table 4843ETEXI 4844
