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 257qemu-system-i386 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 286qemu-system-i386 -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 340qemu-system-i386 -boot order=nc 341# boot from CD-ROM first, switch back to default order after reboot 342qemu-system-i386 -boot once=d 343# boot with a splash picture for 5 seconds. 344qemu-system-i386 -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 373qemu-system-x86_64 -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. 670 671@example 672qemu-system-i386 -soundhw sb16,adlib disk.img 673qemu-system-i386 -soundhw es1370 disk.img 674qemu-system-i386 -soundhw ac97 disk.img 675qemu-system-i386 -soundhw hda disk.img 676qemu-system-i386 -soundhw all disk.img 677qemu-system-i386 -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 1152qemu-system-i386 -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 1158qemu-system-i386 -drive file=file,index=0,media=disk 1159qemu-system-i386 -drive file=file,index=1,media=disk 1160qemu-system-i386 -drive file=file,index=2,media=disk 1161qemu-system-i386 -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 1166qemu-system-i386 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 1174qemu-system-i386 -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 1179qemu-system-i386 -drive if=ide,index=1,media=cdrom 1180@end example 1181 1182Instead of @option{-fda}, @option{-fdb}, you can use: 1183@example 1184qemu-system-i386 -drive file=file,index=0,if=floppy 1185qemu-system-i386 -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 1191qemu-system-i386 -drive file=a -drive file=b" 1192@end example 1193is interpreted like: 1194@example 1195qemu-system-i386 -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 the USB driver (if it is not used by default yet)\n", 1440 QEMU_ARCH_ALL) 1441STEXI 1442@item -usb 1443@findex -usb 1444Enable the USB driver (if it is not used by default yet). 1445ETEXI 1446 1447DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1448 "-usbdevice name add the host or guest USB device 'name'\n", 1449 QEMU_ARCH_ALL) 1450STEXI 1451 1452@item -usbdevice @var{devname} 1453@findex -usbdevice 1454Add the USB device @var{devname}. Note that this option is deprecated, 1455please use @code{-device usb-...} instead. @xref{usb_devices}. 1456 1457@table @option 1458 1459@item mouse 1460Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1461 1462@item tablet 1463Pointer device that uses absolute coordinates (like a touchscreen). This 1464means QEMU is able to report the mouse position without having to grab the 1465mouse. Also overrides the PS/2 mouse emulation when activated. 1466 1467@item braille 1468Braille device. This will use BrlAPI to display the braille output on a real 1469or fake device. 1470 1471@end table 1472ETEXI 1473 1474STEXI 1475@end table 1476ETEXI 1477DEFHEADING() 1478 1479DEFHEADING(Display options:) 1480STEXI 1481@table @option 1482ETEXI 1483 1484DEF("display", HAS_ARG, QEMU_OPTION_display, 1485 "-display spice-app[,gl=on|off]\n" 1486 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1487 " [,window_close=on|off][,gl=on|core|es|off]\n" 1488 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1489 "-display vnc=<display>[,<optargs>]\n" 1490 "-display curses[,charset=<encoding>]\n" 1491 "-display none\n" 1492 "-display egl-headless[,rendernode=<file>]" 1493 " select display type\n" 1494 "The default display is equivalent to\n" 1495#if defined(CONFIG_GTK) 1496 "\t\"-display gtk\"\n" 1497#elif defined(CONFIG_SDL) 1498 "\t\"-display sdl\"\n" 1499#elif defined(CONFIG_COCOA) 1500 "\t\"-display cocoa\"\n" 1501#elif defined(CONFIG_VNC) 1502 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1503#else 1504 "\t\"-display none\"\n" 1505#endif 1506 , QEMU_ARCH_ALL) 1507STEXI 1508@item -display @var{type} 1509@findex -display 1510Select type of display to use. This option is a replacement for the 1511old style -sdl/-curses/... options. Valid values for @var{type} are 1512@table @option 1513@item sdl 1514Display video output via SDL (usually in a separate graphics 1515window; see the SDL documentation for other possibilities). 1516@item curses 1517Display video output via curses. For graphics device models which 1518support a text mode, QEMU can display this output using a 1519curses/ncurses interface. Nothing is displayed when the graphics 1520device is in graphical mode or if the graphics device does not support 1521a text mode. Generally only the VGA device models support text mode. 1522The font charset used by the guest can be specified with the 1523@code{charset} option, for example @code{charset=CP850} for IBM CP850 1524encoding. The default is @code{CP437}. 1525@item none 1526Do not display video output. The guest will still see an emulated 1527graphics card, but its output will not be displayed to the QEMU 1528user. This option differs from the -nographic option in that it 1529only affects what is done with video output; -nographic also changes 1530the destination of the serial and parallel port data. 1531@item gtk 1532Display video output in a GTK window. This interface provides drop-down 1533menus and other UI elements to configure and control the VM during 1534runtime. 1535@item vnc 1536Start a VNC server on display <arg> 1537@item egl-headless 1538Offload all OpenGL operations to a local DRI device. For any graphical display, 1539this display needs to be paired with either VNC or SPICE displays. 1540@item spice-app 1541Start QEMU as a Spice server and launch the default Spice client 1542application. The Spice server will redirect the serial consoles and 1543QEMU monitors. (Since 4.0) 1544@end table 1545ETEXI 1546 1547DEF("nographic", 0, QEMU_OPTION_nographic, 1548 "-nographic disable graphical output and redirect serial I/Os to console\n", 1549 QEMU_ARCH_ALL) 1550STEXI 1551@item -nographic 1552@findex -nographic 1553Normally, if QEMU is compiled with graphical window support, it displays 1554output such as guest graphics, guest console, and the QEMU monitor in a 1555window. With this option, you can totally disable graphical output so 1556that QEMU is a simple command line application. The emulated serial port 1557is redirected on the console and muxed with the monitor (unless 1558redirected elsewhere explicitly). Therefore, you can still use QEMU to 1559debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1560switching between the console and monitor. 1561ETEXI 1562 1563DEF("curses", 0, QEMU_OPTION_curses, 1564 "-curses shorthand for -display curses\n", 1565 QEMU_ARCH_ALL) 1566STEXI 1567@item -curses 1568@findex -curses 1569Normally, if QEMU is compiled with graphical window support, it displays 1570output such as guest graphics, guest console, and the QEMU monitor in a 1571window. With this option, QEMU can display the VGA output when in text 1572mode using a curses/ncurses interface. Nothing is displayed in graphical 1573mode. 1574ETEXI 1575 1576DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1577 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1578 QEMU_ARCH_ALL) 1579STEXI 1580@item -alt-grab 1581@findex -alt-grab 1582Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1583affects the special keys (for fullscreen, monitor-mode switching, etc). 1584ETEXI 1585 1586DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1587 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1588 QEMU_ARCH_ALL) 1589STEXI 1590@item -ctrl-grab 1591@findex -ctrl-grab 1592Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1593affects the special keys (for fullscreen, monitor-mode switching, etc). 1594ETEXI 1595 1596DEF("no-quit", 0, QEMU_OPTION_no_quit, 1597 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1598STEXI 1599@item -no-quit 1600@findex -no-quit 1601Disable SDL window close capability. 1602ETEXI 1603 1604DEF("sdl", 0, QEMU_OPTION_sdl, 1605 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1606STEXI 1607@item -sdl 1608@findex -sdl 1609Enable SDL. 1610ETEXI 1611 1612DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1613 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1614 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1615 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1616 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1617 " [,tls-ciphers=<list>]\n" 1618 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1619 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1620 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1621 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1622 " [,jpeg-wan-compression=[auto|never|always]]\n" 1623 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1624 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1625 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1626 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1627 " [,gl=[on|off]][,rendernode=<file>]\n" 1628 " enable spice\n" 1629 " at least one of {port, tls-port} is mandatory\n", 1630 QEMU_ARCH_ALL) 1631STEXI 1632@item -spice @var{option}[,@var{option}[,...]] 1633@findex -spice 1634Enable the spice remote desktop protocol. Valid options are 1635 1636@table @option 1637 1638@item port=<nr> 1639Set the TCP port spice is listening on for plaintext channels. 1640 1641@item addr=<addr> 1642Set the IP address spice is listening on. Default is any address. 1643 1644@item ipv4 1645@itemx ipv6 1646@itemx unix 1647Force using the specified IP version. 1648 1649@item password=<secret> 1650Set the password you need to authenticate. 1651 1652@item sasl 1653Require that the client use SASL to authenticate with the spice. 1654The exact choice of authentication method used is controlled from the 1655system / user's SASL configuration file for the 'qemu' service. This 1656is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1657unprivileged user, an environment variable SASL_CONF_PATH can be used 1658to make it search alternate locations for the service config. 1659While some SASL auth methods can also provide data encryption (eg GSSAPI), 1660it is recommended that SASL always be combined with the 'tls' and 1661'x509' settings to enable use of SSL and server certificates. This 1662ensures a data encryption preventing compromise of authentication 1663credentials. 1664 1665@item disable-ticketing 1666Allow client connects without authentication. 1667 1668@item disable-copy-paste 1669Disable copy paste between the client and the guest. 1670 1671@item disable-agent-file-xfer 1672Disable spice-vdagent based file-xfer between the client and the guest. 1673 1674@item tls-port=<nr> 1675Set the TCP port spice is listening on for encrypted channels. 1676 1677@item x509-dir=<dir> 1678Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1679 1680@item x509-key-file=<file> 1681@itemx x509-key-password=<file> 1682@itemx x509-cert-file=<file> 1683@itemx x509-cacert-file=<file> 1684@itemx x509-dh-key-file=<file> 1685The x509 file names can also be configured individually. 1686 1687@item tls-ciphers=<list> 1688Specify which ciphers to use. 1689 1690@item tls-channel=[main|display|cursor|inputs|record|playback] 1691@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1692Force specific channel to be used with or without TLS encryption. The 1693options can be specified multiple times to configure multiple 1694channels. The special name "default" can be used to set the default 1695mode. For channels which are not explicitly forced into one mode the 1696spice client is allowed to pick tls/plaintext as he pleases. 1697 1698@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1699Configure image compression (lossless). 1700Default is auto_glz. 1701 1702@item jpeg-wan-compression=[auto|never|always] 1703@itemx zlib-glz-wan-compression=[auto|never|always] 1704Configure wan image compression (lossy for slow links). 1705Default is auto. 1706 1707@item streaming-video=[off|all|filter] 1708Configure video stream detection. Default is off. 1709 1710@item agent-mouse=[on|off] 1711Enable/disable passing mouse events via vdagent. Default is on. 1712 1713@item playback-compression=[on|off] 1714Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1715 1716@item seamless-migration=[on|off] 1717Enable/disable spice seamless migration. Default is off. 1718 1719@item gl=[on|off] 1720Enable/disable OpenGL context. Default is off. 1721 1722@item rendernode=<file> 1723DRM render node for OpenGL rendering. If not specified, it will pick 1724the first available. (Since 2.9) 1725 1726@end table 1727ETEXI 1728 1729DEF("portrait", 0, QEMU_OPTION_portrait, 1730 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1731 QEMU_ARCH_ALL) 1732STEXI 1733@item -portrait 1734@findex -portrait 1735Rotate graphical output 90 deg left (only PXA LCD). 1736ETEXI 1737 1738DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1739 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1740 QEMU_ARCH_ALL) 1741STEXI 1742@item -rotate @var{deg} 1743@findex -rotate 1744Rotate graphical output some deg left (only PXA LCD). 1745ETEXI 1746 1747DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1748 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1749 " select video card type\n", QEMU_ARCH_ALL) 1750STEXI 1751@item -vga @var{type} 1752@findex -vga 1753Select type of VGA card to emulate. Valid values for @var{type} are 1754@table @option 1755@item cirrus 1756Cirrus Logic GD5446 Video card. All Windows versions starting from 1757Windows 95 should recognize and use this graphic card. For optimal 1758performances, use 16 bit color depth in the guest and the host OS. 1759(This card was the default before QEMU 2.2) 1760@item std 1761Standard VGA card with Bochs VBE extensions. If your guest OS 1762supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1763to use high resolution modes (>= 1280x1024x16) then you should use 1764this option. (This card is the default since QEMU 2.2) 1765@item vmware 1766VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1767recent XFree86/XOrg server or Windows guest with a driver for this 1768card. 1769@item qxl 1770QXL paravirtual graphic card. It is VGA compatible (including VESA 17712.0 VBE support). Works best with qxl guest drivers installed though. 1772Recommended choice when using the spice protocol. 1773@item tcx 1774(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1775sun4m machines and offers both 8-bit and 24-bit colour depths at a 1776fixed resolution of 1024x768. 1777@item cg3 1778(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1779for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1780resolutions aimed at people wishing to run older Solaris versions. 1781@item virtio 1782Virtio VGA card. 1783@item none 1784Disable VGA card. 1785@end table 1786ETEXI 1787 1788DEF("full-screen", 0, QEMU_OPTION_full_screen, 1789 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1790STEXI 1791@item -full-screen 1792@findex -full-screen 1793Start in full screen. 1794ETEXI 1795 1796DEF("g", 1, QEMU_OPTION_g , 1797 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1798 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1799STEXI 1800@item -g @var{width}x@var{height}[x@var{depth}] 1801@findex -g 1802Set the initial graphical resolution and depth (PPC, SPARC only). 1803ETEXI 1804 1805DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1806 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1807STEXI 1808@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1809@findex -vnc 1810Normally, if QEMU is compiled with graphical window support, it displays 1811output such as guest graphics, guest console, and the QEMU monitor in a 1812window. With this option, you can have QEMU listen on VNC display 1813@var{display} and redirect the VGA display over the VNC session. It is 1814very useful to enable the usb tablet device when using this option 1815(option @option{-device usb-tablet}). When using the VNC display, you 1816must use the @option{-k} parameter to set the keyboard layout if you are 1817not using en-us. Valid syntax for the @var{display} is 1818 1819@table @option 1820 1821@item to=@var{L} 1822 1823With this option, QEMU will try next available VNC @var{display}s, until the 1824number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1825available, e.g. port 5900+@var{display} is already used by another 1826application. By default, to=0. 1827 1828@item @var{host}:@var{d} 1829 1830TCP connections will only be allowed from @var{host} on display @var{d}. 1831By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1832be omitted in which case the server will accept connections from any host. 1833 1834@item unix:@var{path} 1835 1836Connections will be allowed over UNIX domain sockets where @var{path} is the 1837location of a unix socket to listen for connections on. 1838 1839@item none 1840 1841VNC is initialized but not started. The monitor @code{change} command 1842can be used to later start the VNC server. 1843 1844@end table 1845 1846Following the @var{display} value there may be one or more @var{option} flags 1847separated by commas. Valid options are 1848 1849@table @option 1850 1851@item reverse 1852 1853Connect to a listening VNC client via a ``reverse'' connection. The 1854client is specified by the @var{display}. For reverse network 1855connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1856is a TCP port number, not a display number. 1857 1858@item websocket 1859 1860Opens an additional TCP listening port dedicated to VNC Websocket connections. 1861If a bare @var{websocket} option is given, the Websocket port is 18625700+@var{display}. An alternative port can be specified with the 1863syntax @code{websocket}=@var{port}. 1864 1865If @var{host} is specified connections will only be allowed from this host. 1866It is possible to control the websocket listen address independently, using 1867the syntax @code{websocket}=@var{host}:@var{port}. 1868 1869If no TLS credentials are provided, the websocket connection runs in 1870unencrypted mode. If TLS credentials are provided, the websocket connection 1871requires encrypted client connections. 1872 1873@item password 1874 1875Require that password based authentication is used for client connections. 1876 1877The password must be set separately using the @code{set_password} command in 1878the @ref{pcsys_monitor}. The syntax to change your password is: 1879@code{set_password <protocol> <password>} where <protocol> could be either 1880"vnc" or "spice". 1881 1882If you would like to change <protocol> password expiration, you should use 1883@code{expire_password <protocol> <expiration-time>} where expiration time could 1884be one of the following options: now, never, +seconds or UNIX time of 1885expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1886to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1887date and time). 1888 1889You can also use keywords "now" or "never" for the expiration time to 1890allow <protocol> password to expire immediately or never expire. 1891 1892@item tls-creds=@var{ID} 1893 1894Provides the ID of a set of TLS credentials to use to secure the 1895VNC server. They will apply to both the normal VNC server socket 1896and the websocket socket (if enabled). Setting TLS credentials 1897will cause the VNC server socket to enable the VeNCrypt auth 1898mechanism. The credentials should have been previously created 1899using the @option{-object tls-creds} argument. 1900 1901@item tls-authz=@var{ID} 1902 1903Provides the ID of the QAuthZ authorization object against which 1904the client's x509 distinguished name will validated. This object is 1905only resolved at time of use, so can be deleted and recreated on the 1906fly while the VNC server is active. If missing, it will default 1907to denying access. 1908 1909@item sasl 1910 1911Require that the client use SASL to authenticate with the VNC server. 1912The exact choice of authentication method used is controlled from the 1913system / user's SASL configuration file for the 'qemu' service. This 1914is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1915unprivileged user, an environment variable SASL_CONF_PATH can be used 1916to make it search alternate locations for the service config. 1917While some SASL auth methods can also provide data encryption (eg GSSAPI), 1918it is recommended that SASL always be combined with the 'tls' and 1919'x509' settings to enable use of SSL and server certificates. This 1920ensures a data encryption preventing compromise of authentication 1921credentials. See the @ref{vnc_security} section for details on using 1922SASL authentication. 1923 1924@item sasl-authz=@var{ID} 1925 1926Provides the ID of the QAuthZ authorization object against which 1927the client's SASL username will validated. This object is 1928only resolved at time of use, so can be deleted and recreated on the 1929fly while the VNC server is active. If missing, it will default 1930to denying access. 1931 1932@item acl 1933 1934Legacy method for enabling authorization of clients against the 1935x509 distinguished name and SASL username. It results in the creation 1936of two @code{authz-list} objects with IDs of @code{vnc.username} and 1937@code{vnc.x509dname}. The rules for these objects must be configured 1938with the HMP ACL commands. 1939 1940This option is deprecated and should no longer be used. The new 1941@option{sasl-authz} and @option{tls-authz} options are a 1942replacement. 1943 1944@item lossy 1945 1946Enable lossy compression methods (gradient, JPEG, ...). If this 1947option is set, VNC client may receive lossy framebuffer updates 1948depending on its encoding settings. Enabling this option can save 1949a lot of bandwidth at the expense of quality. 1950 1951@item non-adaptive 1952 1953Disable adaptive encodings. Adaptive encodings are enabled by default. 1954An adaptive encoding will try to detect frequently updated screen regions, 1955and send updates in these regions using a lossy encoding (like JPEG). 1956This can be really helpful to save bandwidth when playing videos. Disabling 1957adaptive encodings restores the original static behavior of encodings 1958like Tight. 1959 1960@item share=[allow-exclusive|force-shared|ignore] 1961 1962Set display sharing policy. 'allow-exclusive' allows clients to ask 1963for exclusive access. As suggested by the rfb spec this is 1964implemented by dropping other connections. Connecting multiple 1965clients in parallel requires all clients asking for a shared session 1966(vncviewer: -shared switch). This is the default. 'force-shared' 1967disables exclusive client access. Useful for shared desktop sessions, 1968where you don't want someone forgetting specify -shared disconnect 1969everybody else. 'ignore' completely ignores the shared flag and 1970allows everybody connect unconditionally. Doesn't conform to the rfb 1971spec but is traditional QEMU behavior. 1972 1973@item key-delay-ms 1974 1975Set keyboard delay, for key down and key up events, in milliseconds. 1976Default is 10. Keyboards are low-bandwidth devices, so this slowdown 1977can help the device and guest to keep up and not lose events in case 1978events are arriving in bulk. Possible causes for the latter are flaky 1979network connections, or scripts for automated testing. 1980 1981@end table 1982ETEXI 1983 1984STEXI 1985@end table 1986ETEXI 1987ARCHHEADING(, QEMU_ARCH_I386) 1988 1989ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1990STEXI 1991@table @option 1992ETEXI 1993 1994DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1995 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1996 QEMU_ARCH_I386) 1997STEXI 1998@item -win2k-hack 1999@findex -win2k-hack 2000Use it when installing Windows 2000 to avoid a disk full bug. After 2001Windows 2000 is installed, you no longer need this option (this option 2002slows down the IDE transfers). 2003ETEXI 2004 2005DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2006 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2007 QEMU_ARCH_I386) 2008STEXI 2009@item -no-fd-bootchk 2010@findex -no-fd-bootchk 2011Disable boot signature checking for floppy disks in BIOS. May 2012be needed to boot from old floppy disks. 2013ETEXI 2014 2015DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2016 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2017STEXI 2018@item -no-acpi 2019@findex -no-acpi 2020Disable ACPI (Advanced Configuration and Power Interface) support. Use 2021it if your guest OS complains about ACPI problems (PC target machine 2022only). 2023ETEXI 2024 2025DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2026 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2027STEXI 2028@item -no-hpet 2029@findex -no-hpet 2030Disable HPET support. 2031ETEXI 2032 2033DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2034 "-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" 2035 " ACPI table description\n", QEMU_ARCH_I386) 2036STEXI 2037@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}]...] 2038@findex -acpitable 2039Add ACPI table with specified header fields and context from specified files. 2040For file=, take whole ACPI table from the specified files, including all 2041ACPI headers (possible overridden by other options). 2042For data=, only data 2043portion of the table is used, all header information is specified in the 2044command line. 2045If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2046fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2047to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2048spec. 2049ETEXI 2050 2051DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2052 "-smbios file=binary\n" 2053 " load SMBIOS entry from binary file\n" 2054 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2055 " [,uefi=on|off]\n" 2056 " specify SMBIOS type 0 fields\n" 2057 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2058 " [,uuid=uuid][,sku=str][,family=str]\n" 2059 " specify SMBIOS type 1 fields\n" 2060 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2061 " [,asset=str][,location=str]\n" 2062 " specify SMBIOS type 2 fields\n" 2063 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2064 " [,sku=str]\n" 2065 " specify SMBIOS type 3 fields\n" 2066 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2067 " [,asset=str][,part=str]\n" 2068 " specify SMBIOS type 4 fields\n" 2069 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2070 " [,asset=str][,part=str][,speed=%d]\n" 2071 " specify SMBIOS type 17 fields\n", 2072 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2073STEXI 2074@item -smbios file=@var{binary} 2075@findex -smbios 2076Load SMBIOS entry from binary file. 2077 2078@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2079Specify SMBIOS type 0 fields 2080 2081@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}] 2082Specify SMBIOS type 1 fields 2083 2084@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2085Specify SMBIOS type 2 fields 2086 2087@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2088Specify SMBIOS type 3 fields 2089 2090@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2091Specify SMBIOS type 4 fields 2092 2093@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}] 2094Specify SMBIOS type 17 fields 2095ETEXI 2096 2097STEXI 2098@end table 2099ETEXI 2100DEFHEADING() 2101 2102DEFHEADING(Network options:) 2103STEXI 2104@table @option 2105ETEXI 2106 2107DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2108#ifdef CONFIG_SLIRP 2109 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2110 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2111 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2112 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2113 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2114#ifndef _WIN32 2115 "[,smb=dir[,smbserver=addr]]\n" 2116#endif 2117 " configure a user mode network backend with ID 'str',\n" 2118 " its DHCP server and optional services\n" 2119#endif 2120#ifdef _WIN32 2121 "-netdev tap,id=str,ifname=name\n" 2122 " configure a host TAP network backend with ID 'str'\n" 2123#else 2124 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2125 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2126 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2127 " [,poll-us=n]\n" 2128 " configure a host TAP network backend with ID 'str'\n" 2129 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2130 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2131 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2132 " to deconfigure it\n" 2133 " use '[down]script=no' to disable script execution\n" 2134 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2135 " configure it\n" 2136 " use 'fd=h' to connect to an already opened TAP interface\n" 2137 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2138 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2139 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2140 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2141 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2142 " use vhost=on to enable experimental in kernel accelerator\n" 2143 " (only has effect for virtio guests which use MSIX)\n" 2144 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2145 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2146 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2147 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2148 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2149 " spent on busy polling for vhost net\n" 2150 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2151 " configure a host TAP network backend with ID 'str' that is\n" 2152 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2153 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2154#endif 2155#ifdef __linux__ 2156 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2157 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2158 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2159 " [,rxcookie=rxcookie][,offset=offset]\n" 2160 " configure a network backend with ID 'str' connected to\n" 2161 " an Ethernet over L2TPv3 pseudowire.\n" 2162 " Linux kernel 3.3+ as well as most routers can talk\n" 2163 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2164 " VM to a router and even VM to Host. It is a nearly-universal\n" 2165 " standard (RFC3391). Note - this implementation uses static\n" 2166 " pre-configured tunnels (same as the Linux kernel).\n" 2167 " use 'src=' to specify source address\n" 2168 " use 'dst=' to specify destination address\n" 2169 " use 'udp=on' to specify udp encapsulation\n" 2170 " use 'srcport=' to specify source udp port\n" 2171 " use 'dstport=' to specify destination udp port\n" 2172 " use 'ipv6=on' to force v6\n" 2173 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2174 " well as a weak security measure\n" 2175 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2176 " use 'txcookie=0x012345678' to specify a txcookie\n" 2177 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2178 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2179 " use 'pincounter=on' to work around broken counter handling in peer\n" 2180 " use 'offset=X' to add an extra offset between header and data\n" 2181#endif 2182 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2183 " configure a network backend to connect to another network\n" 2184 " using a socket connection\n" 2185 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2186 " configure a network backend to connect to a multicast maddr and port\n" 2187 " use 'localaddr=addr' to specify the host address to send packets from\n" 2188 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2189 " configure a network backend to connect to another network\n" 2190 " using an UDP tunnel\n" 2191#ifdef CONFIG_VDE 2192 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2193 " configure a network backend to connect to port 'n' of a vde switch\n" 2194 " running on host and listening for incoming connections on 'socketpath'.\n" 2195 " Use group 'groupname' and mode 'octalmode' to change default\n" 2196 " ownership and permissions for communication port.\n" 2197#endif 2198#ifdef CONFIG_NETMAP 2199 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2200 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2201 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2202 " netmap device, defaults to '/dev/netmap')\n" 2203#endif 2204#ifdef CONFIG_POSIX 2205 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2206 " configure a vhost-user network, backed by a chardev 'dev'\n" 2207#endif 2208 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2209 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2210DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2211 "-nic [tap|bridge|" 2212#ifdef CONFIG_SLIRP 2213 "user|" 2214#endif 2215#ifdef __linux__ 2216 "l2tpv3|" 2217#endif 2218#ifdef CONFIG_VDE 2219 "vde|" 2220#endif 2221#ifdef CONFIG_NETMAP 2222 "netmap|" 2223#endif 2224#ifdef CONFIG_POSIX 2225 "vhost-user|" 2226#endif 2227 "socket][,option][,...][mac=macaddr]\n" 2228 " initialize an on-board / default host NIC (using MAC address\n" 2229 " macaddr) and connect it to the given host network backend\n" 2230 "-nic none use it alone to have zero network devices (the default is to\n" 2231 " provided a 'user' network connection)\n", 2232 QEMU_ARCH_ALL) 2233DEF("net", HAS_ARG, QEMU_OPTION_net, 2234 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2235 " configure or create an on-board (or machine default) NIC and\n" 2236 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2237 "-net [" 2238#ifdef CONFIG_SLIRP 2239 "user|" 2240#endif 2241 "tap|" 2242 "bridge|" 2243#ifdef CONFIG_VDE 2244 "vde|" 2245#endif 2246#ifdef CONFIG_NETMAP 2247 "netmap|" 2248#endif 2249 "socket][,option][,option][,...]\n" 2250 " old way to initialize a host network interface\n" 2251 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2252STEXI 2253@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2254@findex -nic 2255This option is a shortcut for configuring both the on-board (default) guest 2256NIC hardware and the host network backend in one go. The host backend options 2257are the same as with the corresponding @option{-netdev} options below. 2258The guest NIC model can be set with @option{model=@var{modelname}}. 2259Use @option{model=help} to list the available device types. 2260The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2261 2262The following two example do exactly the same, to show how @option{-nic} can 2263be used to shorten the command line length (note that the e1000 is the default 2264on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2265@example 2266qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2267qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2268@end example 2269 2270@item -nic none 2271Indicate that no network devices should be configured. It is used to override 2272the default configuration (default NIC with ``user'' host network backend) 2273which is activated if no other networking options are provided. 2274 2275@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2276@findex -netdev 2277Configure user mode host network backend which requires no administrator 2278privilege to run. Valid options are: 2279 2280@table @option 2281@item id=@var{id} 2282Assign symbolic name for use in monitor commands. 2283 2284@item ipv4=on|off and ipv6=on|off 2285Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2286both protocols are enabled. 2287 2288@item net=@var{addr}[/@var{mask}] 2289Set IP network address the guest will see. Optionally specify the netmask, 2290either in the form a.b.c.d or as number of valid top-most bits. Default is 229110.0.2.0/24. 2292 2293@item host=@var{addr} 2294Specify the guest-visible address of the host. Default is the 2nd IP in the 2295guest network, i.e. x.x.x.2. 2296 2297@item ipv6-net=@var{addr}[/@var{int}] 2298Set IPv6 network address the guest will see (default is fec0::/64). The 2299network prefix is given in the usual hexadecimal IPv6 address 2300notation. The prefix size is optional, and is given as the number of 2301valid top-most bits (default is 64). 2302 2303@item ipv6-host=@var{addr} 2304Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2305the guest network, i.e. xxxx::2. 2306 2307@item restrict=on|off 2308If this option is enabled, the guest will be isolated, i.e. it will not be 2309able to contact the host and no guest IP packets will be routed over the host 2310to the outside. This option does not affect any explicitly set forwarding rules. 2311 2312@item hostname=@var{name} 2313Specifies the client hostname reported by the built-in DHCP server. 2314 2315@item dhcpstart=@var{addr} 2316Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2317is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2318 2319@item dns=@var{addr} 2320Specify the guest-visible address of the virtual nameserver. The address must 2321be different from the host address. Default is the 3rd IP in the guest network, 2322i.e. x.x.x.3. 2323 2324@item ipv6-dns=@var{addr} 2325Specify the guest-visible address of the IPv6 virtual nameserver. The address 2326must be different from the host address. Default is the 3rd IP in the guest 2327network, i.e. xxxx::3. 2328 2329@item dnssearch=@var{domain} 2330Provides an entry for the domain-search list sent by the built-in 2331DHCP server. More than one domain suffix can be transmitted by specifying 2332this option multiple times. If supported, this will cause the guest to 2333automatically try to append the given domain suffix(es) in case a domain name 2334can not be resolved. 2335 2336Example: 2337@example 2338qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2339@end example 2340 2341@item domainname=@var{domain} 2342Specifies the client domain name reported by the built-in DHCP server. 2343 2344@item tftp=@var{dir} 2345When using the user mode network stack, activate a built-in TFTP 2346server. The files in @var{dir} will be exposed as the root of a TFTP server. 2347The TFTP client on the guest must be configured in binary mode (use the command 2348@code{bin} of the Unix TFTP client). 2349 2350@item tftp-server-name=@var{name} 2351In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 235266). This can be used to advise the guest to load boot files or configurations 2353from a different server than the host address. 2354 2355@item bootfile=@var{file} 2356When using the user mode network stack, broadcast @var{file} as the BOOTP 2357filename. In conjunction with @option{tftp}, this can be used to network boot 2358a guest from a local directory. 2359 2360Example (using pxelinux): 2361@example 2362qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \ 2363 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2364@end example 2365 2366@item smb=@var{dir}[,smbserver=@var{addr}] 2367When using the user mode network stack, activate a built-in SMB 2368server so that Windows OSes can access to the host files in @file{@var{dir}} 2369transparently. The IP address of the SMB server can be set to @var{addr}. By 2370default the 4th IP in the guest network is used, i.e. x.x.x.4. 2371 2372In the guest Windows OS, the line: 2373@example 237410.0.2.4 smbserver 2375@end example 2376must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2377or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2378 2379Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2380 2381Note that a SAMBA server must be installed on the host OS. 2382 2383@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2384Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2385the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2386@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2387given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2388be bound to a specific host interface. If no connection type is set, TCP is 2389used. This option can be given multiple times. 2390 2391For example, to redirect host X11 connection from screen 1 to guest 2392screen 0, use the following: 2393 2394@example 2395# on the host 2396qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2397# this host xterm should open in the guest X11 server 2398xterm -display :1 2399@end example 2400 2401To redirect telnet connections from host port 5555 to telnet port on 2402the guest, use the following: 2403 2404@example 2405# on the host 2406qemu-system-i386 -nic user,hostfwd=tcp::5555-:23 2407telnet localhost 5555 2408@end example 2409 2410Then when you use on the host @code{telnet localhost 5555}, you 2411connect to the guest telnet server. 2412 2413@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2414@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2415Forward guest TCP connections to the IP address @var{server} on port @var{port} 2416to the character device @var{dev} or to a program executed by @var{cmd:command} 2417which gets spawned for each connection. This option can be given multiple times. 2418 2419You can either use a chardev directly and have that one used throughout QEMU's 2420lifetime, like in the following example: 2421 2422@example 2423# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2424# the guest accesses it 2425qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2426@end example 2427 2428Or you can execute a command on every TCP connection established by the guest, 2429so that QEMU behaves similar to an inetd process for that virtual server: 2430 2431@example 2432# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2433# and connect the TCP stream to its stdin/stdout 2434qemu-system-i386 -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2435@end example 2436 2437@end table 2438 2439@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2440Configure a host TAP network backend with ID @var{id}. 2441 2442Use the network script @var{file} to configure it and the network script 2443@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2444automatically provides one. The default network configure script is 2445@file{/etc/qemu-ifup} and the default network deconfigure script is 2446@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2447to disable script execution. 2448 2449If running QEMU as an unprivileged user, use the network helper 2450@var{helper} to configure the TAP interface and attach it to the bridge. 2451The default network helper executable is @file{/path/to/qemu-bridge-helper} 2452and the default bridge device is @file{br0}. 2453 2454@option{fd}=@var{h} can be used to specify the handle of an already 2455opened host TAP interface. 2456 2457Examples: 2458 2459@example 2460#launch a QEMU instance with the default network script 2461qemu-system-i386 linux.img -nic tap 2462@end example 2463 2464@example 2465#launch a QEMU instance with two NICs, each one connected 2466#to a TAP device 2467qemu-system-i386 linux.img \ 2468 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2469 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2470@end example 2471 2472@example 2473#launch a QEMU instance with the default network helper to 2474#connect a TAP device to bridge br0 2475qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \ 2476 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2477@end example 2478 2479@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2480Connect a host TAP network interface to a host bridge device. 2481 2482Use the network helper @var{helper} to configure the TAP interface and 2483attach it to the bridge. The default network helper executable is 2484@file{/path/to/qemu-bridge-helper} and the default bridge 2485device is @file{br0}. 2486 2487Examples: 2488 2489@example 2490#launch a QEMU instance with the default network helper to 2491#connect a TAP device to bridge br0 2492qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2493@end example 2494 2495@example 2496#launch a QEMU instance with the default network helper to 2497#connect a TAP device to bridge qemubr0 2498qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2499@end example 2500 2501@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2502 2503This host network backend can be used to connect the guest's network to 2504another QEMU virtual machine using a TCP socket connection. If @option{listen} 2505is specified, QEMU waits for incoming connections on @var{port} 2506(@var{host} is optional). @option{connect} is used to connect to 2507another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2508specifies an already opened TCP socket. 2509 2510Example: 2511@example 2512# launch a first QEMU instance 2513qemu-system-i386 linux.img \ 2514 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2515 -netdev socket,id=n1,listen=:1234 2516# connect the network of this instance to the network of the first instance 2517qemu-system-i386 linux.img \ 2518 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2519 -netdev socket,id=n2,connect=127.0.0.1:1234 2520@end example 2521 2522@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2523 2524Configure a socket host network backend to share the guest's network traffic 2525with another QEMU virtual machines using a UDP multicast socket, effectively 2526making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2527NOTES: 2528@enumerate 2529@item 2530Several QEMU can be running on different hosts and share same bus (assuming 2531correct multicast setup for these hosts). 2532@item 2533mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2534@url{http://user-mode-linux.sf.net}. 2535@item 2536Use @option{fd=h} to specify an already opened UDP multicast socket. 2537@end enumerate 2538 2539Example: 2540@example 2541# launch one QEMU instance 2542qemu-system-i386 linux.img \ 2543 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2544 -netdev socket,id=n1,mcast=230.0.0.1:1234 2545# launch another QEMU instance on same "bus" 2546qemu-system-i386 linux.img \ 2547 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2548 -netdev socket,id=n2,mcast=230.0.0.1:1234 2549# launch yet another QEMU instance on same "bus" 2550qemu-system-i386 linux.img \ 2551 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2552 -netdev socket,id=n3,mcast=230.0.0.1:1234 2553@end example 2554 2555Example (User Mode Linux compat.): 2556@example 2557# launch QEMU instance (note mcast address selected is UML's default) 2558qemu-system-i386 linux.img \ 2559 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2560 -netdev socket,id=n1,mcast=239.192.168.1:1102 2561# launch UML 2562/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2563@end example 2564 2565Example (send packets from host's 1.2.3.4): 2566@example 2567qemu-system-i386 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,localaddr=1.2.3.4 2570@end example 2571 2572@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}] 2573Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2574popular protocol to transport Ethernet (and other Layer 2) data frames between 2575two systems. It is present in routers, firewalls and the Linux kernel 2576(from version 3.3 onwards). 2577 2578This transport allows a VM to communicate to another VM, router or firewall directly. 2579 2580@table @option 2581@item src=@var{srcaddr} 2582 source address (mandatory) 2583@item dst=@var{dstaddr} 2584 destination address (mandatory) 2585@item udp 2586 select udp encapsulation (default is ip). 2587@item srcport=@var{srcport} 2588 source udp port. 2589@item dstport=@var{dstport} 2590 destination udp port. 2591@item ipv6 2592 force v6, otherwise defaults to v4. 2593@item rxcookie=@var{rxcookie} 2594@itemx txcookie=@var{txcookie} 2595 Cookies are a weak form of security in the l2tpv3 specification. 2596Their function is mostly to prevent misconfiguration. By default they are 32 2597bit. 2598@item cookie64 2599 Set cookie size to 64 bit instead of the default 32 2600@item counter=off 2601 Force a 'cut-down' L2TPv3 with no counter as in 2602draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2603@item pincounter=on 2604 Work around broken counter handling in peer. This may also help on 2605networks which have packet reorder. 2606@item offset=@var{offset} 2607 Add an extra offset between header and data 2608@end table 2609 2610For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2611on the remote Linux host 1.2.3.4: 2612@example 2613# Setup tunnel on linux host using raw ip as encapsulation 2614# on 1.2.3.4 2615ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2616 encap udp udp_sport 16384 udp_dport 16384 2617ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2618 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2619ifconfig vmtunnel0 mtu 1500 2620ifconfig vmtunnel0 up 2621brctl addif br-lan vmtunnel0 2622 2623 2624# on 4.3.2.1 2625# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2626 2627qemu-system-i386 linux.img -device e1000,netdev=n1 \ 2628 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2629 2630@end example 2631 2632@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2633Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2634listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2635and MODE @var{octalmode} to change default ownership and permissions for 2636communication port. This option is only available if QEMU has been compiled 2637with vde support enabled. 2638 2639Example: 2640@example 2641# launch vde switch 2642vde_switch -F -sock /tmp/myswitch 2643# launch QEMU instance 2644qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch 2645@end example 2646 2647@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2648 2649Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2650be a unix domain socket backed one. The vhost-user uses a specifically defined 2651protocol to pass vhost ioctl replacement messages to an application on the other 2652end of the socket. On non-MSIX guests, the feature can be forced with 2653@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2654be created for multiqueue vhost-user. 2655 2656Example: 2657@example 2658qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2659 -numa node,memdev=mem \ 2660 -chardev socket,id=chr0,path=/path/to/socket \ 2661 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2662 -device virtio-net-pci,netdev=net0 2663@end example 2664 2665@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2666 2667Create a hub port on the emulated hub with ID @var{hubid}. 2668 2669The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2670single netdev. Alternatively, you can also connect the hubport to another 2671netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2672 2673@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2674@findex -net 2675Legacy option to configure or create an on-board (or machine default) Network 2676Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2677the default hub), or to the netdev @var{nd}. 2678The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2679can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2680only), and a @var{name} can be assigned for use in monitor commands. 2681Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2682that the card should have; this option currently only affects virtio cards; set 2683@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2684NIC is created. QEMU can emulate several different models of network card. 2685Use @code{-net nic,model=help} for a list of available devices for your target. 2686 2687@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2688Configure a host network backend (with the options corresponding to the same 2689@option{-netdev} option) and connect it to the emulated hub 0 (the default 2690hub). Use @var{name} to specify the name of the hub port. 2691ETEXI 2692 2693STEXI 2694@end table 2695ETEXI 2696DEFHEADING() 2697 2698DEFHEADING(Character device options:) 2699 2700DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2701 "-chardev help\n" 2702 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2703 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2704 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2705 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2706 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2707 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2708 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2709 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2710 " [,logfile=PATH][,logappend=on|off]\n" 2711 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2712 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2713 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2714 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2715 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2716 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2717#ifdef _WIN32 2718 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2719 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2720#else 2721 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2722 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2723#endif 2724#ifdef CONFIG_BRLAPI 2725 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2726#endif 2727#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2728 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2729 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2730 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2731#endif 2732#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2733 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2734 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2735#endif 2736#if defined(CONFIG_SPICE) 2737 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2738 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2739#endif 2740 , QEMU_ARCH_ALL 2741) 2742 2743STEXI 2744 2745The general form of a character device option is: 2746@table @option 2747@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2748@findex -chardev 2749Backend is one of: 2750@option{null}, 2751@option{socket}, 2752@option{udp}, 2753@option{msmouse}, 2754@option{vc}, 2755@option{ringbuf}, 2756@option{file}, 2757@option{pipe}, 2758@option{console}, 2759@option{serial}, 2760@option{pty}, 2761@option{stdio}, 2762@option{braille}, 2763@option{tty}, 2764@option{parallel}, 2765@option{parport}, 2766@option{spicevmc}, 2767@option{spiceport}. 2768The specific backend will determine the applicable options. 2769 2770Use @code{-chardev help} to print all available chardev backend types. 2771 2772All devices must have an id, which can be any string up to 127 characters long. 2773It is used to uniquely identify this device in other command line directives. 2774 2775A character device may be used in multiplexing mode by multiple front-ends. 2776Specify @option{mux=on} to enable this mode. 2777A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2778backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2779If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2780create a multiplexer with your specified ID, and you can then configure multiple 2781front ends to use that chardev ID for their input/output. Up to four different 2782front ends can be connected to a single multiplexed chardev. (Without 2783multiplexing enabled, a chardev can only be used by a single front end.) 2784For instance you could use this to allow a single stdio chardev to be used by 2785two serial ports and the QEMU monitor: 2786 2787@example 2788-chardev stdio,mux=on,id=char0 \ 2789-mon chardev=char0,mode=readline \ 2790-serial chardev:char0 \ 2791-serial chardev:char0 2792@end example 2793 2794You can have more than one multiplexer in a system configuration; for instance 2795you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2796multiplexed between the QEMU monitor and a parallel port: 2797 2798@example 2799-chardev stdio,mux=on,id=char0 \ 2800-mon chardev=char0,mode=readline \ 2801-parallel chardev:char0 \ 2802-chardev tcp,...,mux=on,id=char1 \ 2803-serial chardev:char1 \ 2804-serial chardev:char1 2805@end example 2806 2807When you're using a multiplexed character device, some escape sequences are 2808interpreted in the input. @xref{mux_keys, Keys in the character backend 2809multiplexer}. 2810 2811Note that some other command line options may implicitly create multiplexed 2812character backends; for instance @option{-serial mon:stdio} creates a 2813multiplexed stdio backend connected to the serial port and the QEMU monitor, 2814and @option{-nographic} also multiplexes the console and the monitor to 2815stdio. 2816 2817There is currently no support for multiplexing in the other direction 2818(where a single QEMU front end takes input and output from multiple chardevs). 2819 2820Every backend supports the @option{logfile} option, which supplies the path 2821to a file to record all data transmitted via the backend. The @option{logappend} 2822option controls whether the log file will be truncated or appended to when 2823opened. 2824 2825@end table 2826 2827The available backends are: 2828 2829@table @option 2830@item -chardev null,id=@var{id} 2831A void device. This device will not emit any data, and will drop any data it 2832receives. The null backend does not take any options. 2833 2834@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}] 2835 2836Create a two-way stream socket, which can be either a TCP or a unix socket. A 2837unix socket will be created if @option{path} is specified. Behaviour is 2838undefined if TCP options are specified for a unix socket. 2839 2840@option{server} specifies that the socket shall be a listening socket. 2841 2842@option{nowait} specifies that QEMU should not block waiting for a client to 2843connect to a listening socket. 2844 2845@option{telnet} specifies that traffic on the socket should interpret telnet 2846escape sequences. 2847 2848@option{websocket} specifies that the socket uses WebSocket protocol for 2849communication. 2850 2851@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2852the remote end goes away. qemu will delay this many seconds and then attempt 2853to reconnect. Zero disables reconnecting, and is the default. 2854 2855@option{tls-creds} requests enablement of the TLS protocol for encryption, 2856and specifies the id of the TLS credentials to use for the handshake. The 2857credentials must be previously created with the @option{-object tls-creds} 2858argument. 2859 2860@option{tls-auth} provides the ID of the QAuthZ authorization object against 2861which the client's x509 distinguished name will be validated. This object is 2862only resolved at time of use, so can be deleted and recreated on the fly 2863while the chardev server is active. If missing, it will default to denying 2864access. 2865 2866TCP and unix socket options are given below: 2867 2868@table @option 2869 2870@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2871 2872@option{host} for a listening socket specifies the local address to be bound. 2873For a connecting socket species the remote host to connect to. @option{host} is 2874optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2875 2876@option{port} for a listening socket specifies the local port to be bound. For a 2877connecting socket specifies the port on the remote host to connect to. 2878@option{port} can be given as either a port number or a service name. 2879@option{port} is required. 2880 2881@option{to} is only relevant to listening sockets. If it is specified, and 2882@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2883to and including @option{to} until it succeeds. @option{to} must be specified 2884as a port number. 2885 2886@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2887If neither is specified the socket may use either protocol. 2888 2889@option{nodelay} disables the Nagle algorithm. 2890 2891@item unix options: path=@var{path} 2892 2893@option{path} specifies the local path of the unix socket. @option{path} is 2894required. 2895 2896@end table 2897 2898@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2899 2900Sends all traffic from the guest to a remote host over UDP. 2901 2902@option{host} specifies the remote host to connect to. If not specified it 2903defaults to @code{localhost}. 2904 2905@option{port} specifies the port on the remote host to connect to. @option{port} 2906is required. 2907 2908@option{localaddr} specifies the local address to bind to. If not specified it 2909defaults to @code{0.0.0.0}. 2910 2911@option{localport} specifies the local port to bind to. If not specified any 2912available local port will be used. 2913 2914@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2915If neither is specified the device may use either protocol. 2916 2917@item -chardev msmouse,id=@var{id} 2918 2919Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2920take any options. 2921 2922@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 2923 2924Connect to a QEMU text console. @option{vc} may optionally be given a specific 2925size. 2926 2927@option{width} and @option{height} specify the width and height respectively of 2928the console, in pixels. 2929 2930@option{cols} and @option{rows} specify that the console be sized to fit a text 2931console with the given dimensions. 2932 2933@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 2934 2935Create a ring buffer with fixed size @option{size}. 2936@var{size} must be a power of two and defaults to @code{64K}. 2937 2938@item -chardev file,id=@var{id},path=@var{path} 2939 2940Log all traffic received from the guest to a file. 2941 2942@option{path} specifies the path of the file to be opened. This file will be 2943created if it does not already exist, and overwritten if it does. @option{path} 2944is required. 2945 2946@item -chardev pipe,id=@var{id},path=@var{path} 2947 2948Create a two-way connection to the guest. The behaviour differs slightly between 2949Windows hosts and other hosts: 2950 2951On Windows, a single duplex pipe will be created at 2952@file{\\.pipe\@option{path}}. 2953 2954On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2955@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2956received by the guest. Data written by the guest can be read from 2957@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2958be present. 2959 2960@option{path} forms part of the pipe path as described above. @option{path} is 2961required. 2962 2963@item -chardev console,id=@var{id} 2964 2965Send traffic from the guest to QEMU's standard output. @option{console} does not 2966take any options. 2967 2968@option{console} is only available on Windows hosts. 2969 2970@item -chardev serial,id=@var{id},path=@option{path} 2971 2972Send traffic from the guest to a serial device on the host. 2973 2974On Unix hosts serial will actually accept any tty device, 2975not only serial lines. 2976 2977@option{path} specifies the name of the serial device to open. 2978 2979@item -chardev pty,id=@var{id} 2980 2981Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2982not take any options. 2983 2984@option{pty} is not available on Windows hosts. 2985 2986@item -chardev stdio,id=@var{id}[,signal=on|off] 2987Connect to standard input and standard output of the QEMU process. 2988 2989@option{signal} controls if signals are enabled on the terminal, that includes 2990exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2991default, use @option{signal=off} to disable it. 2992 2993@item -chardev braille,id=@var{id} 2994 2995Connect to a local BrlAPI server. @option{braille} does not take any options. 2996 2997@item -chardev tty,id=@var{id},path=@var{path} 2998 2999@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3000DragonFlyBSD hosts. It is an alias for @option{serial}. 3001 3002@option{path} specifies the path to the tty. @option{path} is required. 3003 3004@item -chardev parallel,id=@var{id},path=@var{path} 3005@itemx -chardev parport,id=@var{id},path=@var{path} 3006 3007@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3008 3009Connect to a local parallel port. 3010 3011@option{path} specifies the path to the parallel port device. @option{path} is 3012required. 3013 3014@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3015 3016@option{spicevmc} is only available when spice support is built in. 3017 3018@option{debug} debug level for spicevmc 3019 3020@option{name} name of spice channel to connect to 3021 3022Connect to a spice virtual machine channel, such as vdiport. 3023 3024@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3025 3026@option{spiceport} is only available when spice support is built in. 3027 3028@option{debug} debug level for spicevmc 3029 3030@option{name} name of spice port to connect to 3031 3032Connect to a spice port, allowing a Spice client to handle the traffic 3033identified by a name (preferably a fqdn). 3034ETEXI 3035 3036STEXI 3037@end table 3038ETEXI 3039DEFHEADING() 3040 3041DEFHEADING(Bluetooth(R) options:) 3042STEXI 3043@table @option 3044ETEXI 3045 3046DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3047 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3048 "-bt hci,host[:id]\n" \ 3049 " use host's HCI with the given name\n" \ 3050 "-bt hci[,vlan=n]\n" \ 3051 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3052 "-bt vhci[,vlan=n]\n" \ 3053 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3054 "-bt device:dev[,vlan=n]\n" \ 3055 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3056 QEMU_ARCH_ALL) 3057STEXI 3058@item -bt hci[...] 3059@findex -bt 3060Defines the function of the corresponding Bluetooth HCI. -bt options 3061are matched with the HCIs present in the chosen machine type. For 3062example when emulating a machine with only one HCI built into it, only 3063the first @code{-bt hci[...]} option is valid and defines the HCI's 3064logic. The Transport Layer is decided by the machine type. Currently 3065the machines @code{n800} and @code{n810} have one HCI and all other 3066machines have none. 3067 3068Note: This option and the whole bluetooth subsystem is considered as deprecated. 3069If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where 3070you describe your usecase. 3071 3072@anchor{bt-hcis} 3073The following three types are recognized: 3074 3075@table @option 3076@item -bt hci,null 3077(default) The corresponding Bluetooth HCI assumes no internal logic 3078and will not respond to any HCI commands or emit events. 3079 3080@item -bt hci,host[:@var{id}] 3081(@code{bluez} only) The corresponding HCI passes commands / events 3082to / from the physical HCI identified by the name @var{id} (default: 3083@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3084capable systems like Linux. 3085 3086@item -bt hci[,vlan=@var{n}] 3087Add a virtual, standard HCI that will participate in the Bluetooth 3088scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3089VLANs, devices inside a bluetooth network @var{n} can only communicate 3090with other devices in the same network (scatternet). 3091@end table 3092 3093@item -bt vhci[,vlan=@var{n}] 3094(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3095to the host bluetooth stack instead of to the emulated target. This 3096allows the host and target machines to participate in a common scatternet 3097and communicate. Requires the Linux @code{vhci} driver installed. Can 3098be used as following: 3099 3100@example 3101qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3102@end example 3103 3104@item -bt device:@var{dev}[,vlan=@var{n}] 3105Emulate a bluetooth device @var{dev} and place it in network @var{n} 3106(default @code{0}). QEMU can only emulate one type of bluetooth devices 3107currently: 3108 3109@table @option 3110@item keyboard 3111Virtual wireless keyboard implementing the HIDP bluetooth profile. 3112@end table 3113ETEXI 3114 3115STEXI 3116@end table 3117ETEXI 3118DEFHEADING() 3119 3120#ifdef CONFIG_TPM 3121DEFHEADING(TPM device options:) 3122 3123DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3124 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3125 " use path to provide path to a character device; default is /dev/tpm0\n" 3126 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3127 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3128 "-tpmdev emulator,id=id,chardev=dev\n" 3129 " configure the TPM device using chardev backend\n", 3130 QEMU_ARCH_ALL) 3131STEXI 3132 3133The general form of a TPM device option is: 3134@table @option 3135 3136@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3137@findex -tpmdev 3138 3139The specific backend type will determine the applicable options. 3140The @code{-tpmdev} option creates the TPM backend and requires a 3141@code{-device} option that specifies the TPM frontend interface model. 3142 3143Use @code{-tpmdev help} to print all available TPM backend types. 3144 3145@end table 3146 3147The available backends are: 3148 3149@table @option 3150 3151@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3152 3153(Linux-host only) Enable access to the host's TPM using the passthrough 3154driver. 3155 3156@option{path} specifies the path to the host's TPM device, i.e., on 3157a Linux host this would be @code{/dev/tpm0}. 3158@option{path} is optional and by default @code{/dev/tpm0} is used. 3159 3160@option{cancel-path} specifies the path to the host TPM device's sysfs 3161entry allowing for cancellation of an ongoing TPM command. 3162@option{cancel-path} is optional and by default QEMU will search for the 3163sysfs entry to use. 3164 3165Some notes about using the host's TPM with the passthrough driver: 3166 3167The TPM device accessed by the passthrough driver must not be 3168used by any other application on the host. 3169 3170Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3171the VM's firmware (BIOS/UEFI) will not be able to initialize the 3172TPM again and may therefore not show a TPM-specific menu that would 3173otherwise allow the user to configure the TPM, e.g., allow the user to 3174enable/disable or activate/deactivate the TPM. 3175Further, if TPM ownership is released from within a VM then the host's TPM 3176will get disabled and deactivated. To enable and activate the 3177TPM again afterwards, the host has to be rebooted and the user is 3178required to enter the firmware's menu to enable and activate the TPM. 3179If the TPM is left disabled and/or deactivated most TPM commands will fail. 3180 3181To create a passthrough TPM use the following two options: 3182@example 3183-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3184@end example 3185Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3186@code{tpmdev=tpm0} in the device option. 3187 3188@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3189 3190(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3191chardev backend. 3192 3193@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3194 3195To create a TPM emulator backend device with chardev socket backend: 3196@example 3197 3198-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3199 3200@end example 3201 3202ETEXI 3203 3204STEXI 3205@end table 3206ETEXI 3207DEFHEADING() 3208 3209#endif 3210 3211DEFHEADING(Linux/Multiboot boot specific:) 3212STEXI 3213 3214When using these options, you can use a given Linux or Multiboot 3215kernel without installing it in the disk image. It can be useful 3216for easier testing of various kernels. 3217 3218@table @option 3219ETEXI 3220 3221DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3222 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3223STEXI 3224@item -kernel @var{bzImage} 3225@findex -kernel 3226Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3227or in multiboot format. 3228ETEXI 3229 3230DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3231 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3232STEXI 3233@item -append @var{cmdline} 3234@findex -append 3235Use @var{cmdline} as kernel command line 3236ETEXI 3237 3238DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3239 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3240STEXI 3241@item -initrd @var{file} 3242@findex -initrd 3243Use @var{file} as initial ram disk. 3244 3245@item -initrd "@var{file1} arg=foo,@var{file2}" 3246 3247This syntax is only available with multiboot. 3248 3249Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3250first module. 3251ETEXI 3252 3253DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3254 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3255STEXI 3256@item -dtb @var{file} 3257@findex -dtb 3258Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3259on boot. 3260ETEXI 3261 3262STEXI 3263@end table 3264ETEXI 3265DEFHEADING() 3266 3267DEFHEADING(Debug/Expert options:) 3268STEXI 3269@table @option 3270ETEXI 3271 3272DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3273 "-fw_cfg [name=]<name>,file=<file>\n" 3274 " add named fw_cfg entry with contents from file\n" 3275 "-fw_cfg [name=]<name>,string=<str>\n" 3276 " add named fw_cfg entry with contents from string\n", 3277 QEMU_ARCH_ALL) 3278STEXI 3279 3280@item -fw_cfg [name=]@var{name},file=@var{file} 3281@findex -fw_cfg 3282Add named fw_cfg entry with contents from file @var{file}. 3283 3284@item -fw_cfg [name=]@var{name},string=@var{str} 3285Add named fw_cfg entry with contents from string @var{str}. 3286 3287The terminating NUL character of the contents of @var{str} will not be 3288included as part of the fw_cfg item data. To insert contents with 3289embedded NUL characters, you have to use the @var{file} parameter. 3290 3291The fw_cfg entries are passed by QEMU through to the guest. 3292 3293Example: 3294@example 3295 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3296@end example 3297creates an fw_cfg entry named opt/com.mycompany/blob with contents 3298from ./my_blob.bin. 3299 3300ETEXI 3301 3302DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3303 "-serial dev redirect the serial port to char device 'dev'\n", 3304 QEMU_ARCH_ALL) 3305STEXI 3306@item -serial @var{dev} 3307@findex -serial 3308Redirect the virtual serial port to host character device 3309@var{dev}. The default device is @code{vc} in graphical mode and 3310@code{stdio} in non graphical mode. 3311 3312This option can be used several times to simulate up to 4 serial 3313ports. 3314 3315Use @code{-serial none} to disable all serial ports. 3316 3317Available character devices are: 3318@table @option 3319@item vc[:@var{W}x@var{H}] 3320Virtual console. Optionally, a width and height can be given in pixel with 3321@example 3322vc:800x600 3323@end example 3324It is also possible to specify width or height in characters: 3325@example 3326vc:80Cx24C 3327@end example 3328@item pty 3329[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3330@item none 3331No device is allocated. 3332@item null 3333void device 3334@item chardev:@var{id} 3335Use a named character device defined with the @code{-chardev} option. 3336@item /dev/XXX 3337[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3338parameters are set according to the emulated ones. 3339@item /dev/parport@var{N} 3340[Linux only, parallel port only] Use host parallel port 3341@var{N}. Currently SPP and EPP parallel port features can be used. 3342@item file:@var{filename} 3343Write output to @var{filename}. No character can be read. 3344@item stdio 3345[Unix only] standard input/output 3346@item pipe:@var{filename} 3347name pipe @var{filename} 3348@item COM@var{n} 3349[Windows only] Use host serial port @var{n} 3350@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3351This implements UDP Net Console. 3352When @var{remote_host} or @var{src_ip} are not specified 3353they default to @code{0.0.0.0}. 3354When not using a specified @var{src_port} a random port is automatically chosen. 3355 3356If you just want a simple readonly console you can use @code{netcat} or 3357@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3358@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3359will appear in the netconsole session. 3360 3361If you plan to send characters back via netconsole or you want to stop 3362and start QEMU a lot of times, you should have QEMU use the same 3363source port each time by using something like @code{-serial 3364udp::4555@@:4556} to QEMU. Another approach is to use a patched 3365version of netcat which can listen to a TCP port and send and receive 3366characters via udp. If you have a patched version of netcat which 3367activates telnet remote echo and single char transfer, then you can 3368use the following options to set up a netcat redirector to allow 3369telnet on port 5555 to access the QEMU port. 3370@table @code 3371@item QEMU Options: 3372-serial udp::4555@@:4556 3373@item netcat options: 3374-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3375@item telnet options: 3376localhost 5555 3377@end table 3378 3379@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3380The TCP Net Console has two modes of operation. It can send the serial 3381I/O to a location or wait for a connection from a location. By default 3382the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3383the @var{server} option QEMU will wait for a client socket application 3384to connect to the port before continuing, unless the @code{nowait} 3385option was specified. The @code{nodelay} option disables the Nagle buffering 3386algorithm. The @code{reconnect} option only applies if @var{noserver} is 3387set, if the connection goes down it will attempt to reconnect at the 3388given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3389one TCP connection at a time is accepted. You can use @code{telnet} to 3390connect to the corresponding character device. 3391@table @code 3392@item Example to send tcp console to 192.168.0.2 port 4444 3393-serial tcp:192.168.0.2:4444 3394@item Example to listen and wait on port 4444 for connection 3395-serial tcp::4444,server 3396@item Example to not wait and listen on ip 192.168.0.100 port 4444 3397-serial tcp:192.168.0.100:4444,server,nowait 3398@end table 3399 3400@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3401The telnet protocol is used instead of raw tcp sockets. The options 3402work the same as if you had specified @code{-serial tcp}. The 3403difference is that the port acts like a telnet server or client using 3404telnet option negotiation. This will also allow you to send the 3405MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3406sequence. Typically in unix telnet you do it with Control-] and then 3407type "send break" followed by pressing the enter key. 3408 3409@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3410The WebSocket protocol is used instead of raw tcp socket. The port acts as 3411a WebSocket server. Client mode is not supported. 3412 3413@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3414A unix domain socket is used instead of a tcp socket. The option works the 3415same as if you had specified @code{-serial tcp} except the unix domain socket 3416@var{path} is used for connections. 3417 3418@item mon:@var{dev_string} 3419This is a special option to allow the monitor to be multiplexed onto 3420another serial port. The monitor is accessed with key sequence of 3421@key{Control-a} and then pressing @key{c}. 3422@var{dev_string} should be any one of the serial devices specified 3423above. An example to multiplex the monitor onto a telnet server 3424listening on port 4444 would be: 3425@table @code 3426@item -serial mon:telnet::4444,server,nowait 3427@end table 3428When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3429QEMU any more but will be passed to the guest instead. 3430 3431@item braille 3432Braille device. This will use BrlAPI to display the braille output on a real 3433or fake device. 3434 3435@item msmouse 3436Three button serial mouse. Configure the guest to use Microsoft protocol. 3437@end table 3438ETEXI 3439 3440DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3441 "-parallel dev redirect the parallel port to char device 'dev'\n", 3442 QEMU_ARCH_ALL) 3443STEXI 3444@item -parallel @var{dev} 3445@findex -parallel 3446Redirect the virtual parallel port to host device @var{dev} (same 3447devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3448be used to use hardware devices connected on the corresponding host 3449parallel port. 3450 3451This option can be used several times to simulate up to 3 parallel 3452ports. 3453 3454Use @code{-parallel none} to disable all parallel ports. 3455ETEXI 3456 3457DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3458 "-monitor dev redirect the monitor to char device 'dev'\n", 3459 QEMU_ARCH_ALL) 3460STEXI 3461@item -monitor @var{dev} 3462@findex -monitor 3463Redirect the monitor to host device @var{dev} (same devices as the 3464serial port). 3465The default device is @code{vc} in graphical mode and @code{stdio} in 3466non graphical mode. 3467Use @code{-monitor none} to disable the default monitor. 3468ETEXI 3469DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3470 "-qmp dev like -monitor but opens in 'control' mode\n", 3471 QEMU_ARCH_ALL) 3472STEXI 3473@item -qmp @var{dev} 3474@findex -qmp 3475Like -monitor but opens in 'control' mode. 3476ETEXI 3477DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3478 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3479 QEMU_ARCH_ALL) 3480STEXI 3481@item -qmp-pretty @var{dev} 3482@findex -qmp-pretty 3483Like -qmp but uses pretty JSON formatting. 3484ETEXI 3485 3486DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3487 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3488STEXI 3489@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3490@findex -mon 3491Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3492easing human reading and debugging. 3493ETEXI 3494 3495DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3496 "-debugcon dev redirect the debug console to char device 'dev'\n", 3497 QEMU_ARCH_ALL) 3498STEXI 3499@item -debugcon @var{dev} 3500@findex -debugcon 3501Redirect the debug console to host device @var{dev} (same devices as the 3502serial port). The debug console is an I/O port which is typically port 35030xe9; writing to that I/O port sends output to this device. 3504The default device is @code{vc} in graphical mode and @code{stdio} in 3505non graphical mode. 3506ETEXI 3507 3508DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3509 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3510STEXI 3511@item -pidfile @var{file} 3512@findex -pidfile 3513Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3514from a script. 3515ETEXI 3516 3517DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3518 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3519STEXI 3520@item -singlestep 3521@findex -singlestep 3522Run the emulation in single step mode. 3523ETEXI 3524 3525DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3526 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3527 QEMU_ARCH_ALL) 3528STEXI 3529@item --preconfig 3530@findex --preconfig 3531Pause QEMU for interactive configuration before the machine is created, 3532which allows querying and configuring properties that will affect 3533machine initialization. Use QMP command 'x-exit-preconfig' to exit 3534the preconfig state and move to the next state (i.e. run guest if -S 3535isn't used or pause the second time if -S is used). This option is 3536experimental. 3537ETEXI 3538 3539DEF("S", 0, QEMU_OPTION_S, \ 3540 "-S freeze CPU at startup (use 'c' to start execution)\n", 3541 QEMU_ARCH_ALL) 3542STEXI 3543@item -S 3544@findex -S 3545Do not start CPU at startup (you must type 'c' in the monitor). 3546ETEXI 3547 3548DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3549 "-realtime [mlock=on|off]\n" 3550 " run qemu with realtime features\n" 3551 " mlock=on|off controls mlock support (default: on)\n", 3552 QEMU_ARCH_ALL) 3553STEXI 3554@item -realtime mlock=on|off 3555@findex -realtime 3556Run qemu with realtime features. 3557mlocking qemu and guest memory can be enabled via @option{mlock=on} 3558(enabled by default). 3559ETEXI 3560 3561DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3562 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3563 " run qemu with overcommit hints\n" 3564 " mem-lock=on|off controls memory lock support (default: off)\n" 3565 " cpu-pm=on|off controls cpu power management (default: off)\n", 3566 QEMU_ARCH_ALL) 3567STEXI 3568@item -overcommit mem-lock=on|off 3569@item -overcommit cpu-pm=on|off 3570@findex -overcommit 3571Run qemu with hints about host resource overcommit. The default is 3572to assume that host overcommits all resources. 3573 3574Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3575by default). This works when host memory is not overcommitted and reduces the 3576worst-case latency for guest. This is equivalent to @option{realtime}. 3577 3578Guest ability to manage power state of host cpus (increasing latency for other 3579processes on the same host cpu, but decreasing latency for guest) can be 3580enabled via @option{cpu-pm=on} (disabled by default). This works best when 3581host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3582utilization will be incorrect, not taking into account guest idle time. 3583ETEXI 3584 3585DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3586 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3587STEXI 3588@item -gdb @var{dev} 3589@findex -gdb 3590Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3591connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3592stdio are reasonable use case. The latter is allowing to start QEMU from 3593within gdb and establish the connection via a pipe: 3594@example 3595(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3596@end example 3597ETEXI 3598 3599DEF("s", 0, QEMU_OPTION_s, \ 3600 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3601 QEMU_ARCH_ALL) 3602STEXI 3603@item -s 3604@findex -s 3605Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3606(@pxref{gdb_usage}). 3607ETEXI 3608 3609DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3610 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3611 QEMU_ARCH_ALL) 3612STEXI 3613@item -d @var{item1}[,...] 3614@findex -d 3615Enable logging of specified items. Use '-d help' for a list of log items. 3616ETEXI 3617 3618DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3619 "-D logfile output log to logfile (default stderr)\n", 3620 QEMU_ARCH_ALL) 3621STEXI 3622@item -D @var{logfile} 3623@findex -D 3624Output log in @var{logfile} instead of to stderr 3625ETEXI 3626 3627DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3628 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3629 QEMU_ARCH_ALL) 3630STEXI 3631@item -dfilter @var{range1}[,...] 3632@findex -dfilter 3633Filter debug output to that relevant to a range of target addresses. The filter 3634spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3635@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3636addresses and sizes required. For example: 3637@example 3638 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3639@end example 3640Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3641the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3642block starting at 0xffffffc00005f000. 3643ETEXI 3644 3645DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3646 "-seed number seed the pseudo-random number generator\n", 3647 QEMU_ARCH_ALL) 3648STEXI 3649@item -seed @var{number} 3650@findex -seed 3651Force the guest to use a deterministic pseudo-random number generator, seeded 3652with @var{number}. This does not affect crypto routines within the host. 3653ETEXI 3654 3655DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3656 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3657 QEMU_ARCH_ALL) 3658STEXI 3659@item -L @var{path} 3660@findex -L 3661Set the directory for the BIOS, VGA BIOS and keymaps. 3662 3663To list all the data directories, use @code{-L help}. 3664ETEXI 3665 3666DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3667 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3668STEXI 3669@item -bios @var{file} 3670@findex -bios 3671Set the filename for the BIOS. 3672ETEXI 3673 3674DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3675 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3676STEXI 3677@item -enable-kvm 3678@findex -enable-kvm 3679Enable KVM full virtualization support. This option is only available 3680if KVM support is enabled when compiling. 3681ETEXI 3682 3683DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3684 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3685DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3686 "-xen-attach attach to existing xen domain\n" 3687 " libxl will use this when starting QEMU\n", 3688 QEMU_ARCH_ALL) 3689DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3690 "-xen-domid-restrict restrict set of available xen operations\n" 3691 " to specified domain id. (Does not affect\n" 3692 " xenpv machine type).\n", 3693 QEMU_ARCH_ALL) 3694STEXI 3695@item -xen-domid @var{id} 3696@findex -xen-domid 3697Specify xen guest domain @var{id} (XEN only). 3698@item -xen-attach 3699@findex -xen-attach 3700Attach to existing xen domain. 3701libxl will use this when starting QEMU (XEN only). 3702@findex -xen-domid-restrict 3703Restrict set of available xen operations to specified domain id (XEN only). 3704ETEXI 3705 3706DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3707 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3708STEXI 3709@item -no-reboot 3710@findex -no-reboot 3711Exit instead of rebooting. 3712ETEXI 3713 3714DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3715 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3716STEXI 3717@item -no-shutdown 3718@findex -no-shutdown 3719Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3720This allows for instance switching to monitor to commit changes to the 3721disk image. 3722ETEXI 3723 3724DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3725 "-loadvm [tag|id]\n" \ 3726 " start right away with a saved state (loadvm in monitor)\n", 3727 QEMU_ARCH_ALL) 3728STEXI 3729@item -loadvm @var{file} 3730@findex -loadvm 3731Start right away with a saved state (@code{loadvm} in monitor) 3732ETEXI 3733 3734#ifndef _WIN32 3735DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3736 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3737#endif 3738STEXI 3739@item -daemonize 3740@findex -daemonize 3741Daemonize the QEMU process after initialization. QEMU will not detach from 3742standard IO until it is ready to receive connections on any of its devices. 3743This option is a useful way for external programs to launch QEMU without having 3744to cope with initialization race conditions. 3745ETEXI 3746 3747DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3748 "-option-rom rom load a file, rom, into the option ROM space\n", 3749 QEMU_ARCH_ALL) 3750STEXI 3751@item -option-rom @var{file} 3752@findex -option-rom 3753Load the contents of @var{file} as an option ROM. 3754This option is useful to load things like EtherBoot. 3755ETEXI 3756 3757DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3758 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3759 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3760 QEMU_ARCH_ALL) 3761 3762STEXI 3763 3764@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3765@findex -rtc 3766Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3767UTC or local time, respectively. @code{localtime} is required for correct date in 3768MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3769format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3770 3771By default the RTC is driven by the host system time. This allows using of the 3772RTC as accurate reference clock inside the guest, specifically if the host 3773time is smoothly following an accurate external reference clock, e.g. via NTP. 3774If you want to isolate the guest time from the host, you can set @option{clock} 3775to @code{rt} instead, which provides a host monotonic clock if host support it. 3776To even prevent the RTC from progressing during suspension, you can set @option{clock} 3777to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3778icount mode in order to preserve determinism; however, note that in icount mode 3779the speed of the virtual clock is variable and can in general differ from the 3780host clock. 3781 3782Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3783specifically with Windows' ACPI HAL. This option will try to figure out how 3784many timer interrupts were not processed by the Windows guest and will 3785re-inject them. 3786ETEXI 3787 3788DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3789 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3790 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3791 " instruction, enable aligning the host and virtual clocks\n" \ 3792 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3793STEXI 3794@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3795@findex -icount 3796Enable virtual instruction counter. The virtual cpu will execute one 3797instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3798then the virtual cpu speed will be automatically adjusted to keep virtual 3799time within a few seconds of real time. 3800 3801When the virtual cpu is sleeping, the virtual time will advance at default 3802speed unless @option{sleep=on|off} is specified. 3803With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3804instantly whenever the virtual cpu goes to sleep mode and will not advance 3805if no timer is enabled. This behavior give deterministic execution times from 3806the guest point of view. 3807 3808Note that while this option can give deterministic behavior, it does not 3809provide cycle accurate emulation. Modern CPUs contain superscalar out of 3810order cores with complex cache hierarchies. The number of instructions 3811executed often has little or no correlation with actual performance. 3812 3813@option{align=on} will activate the delay algorithm which will try 3814to synchronise the host clock and the virtual clock. The goal is to 3815have a guest running at the real frequency imposed by the shift option. 3816Whenever the guest clock is behind the host clock and if 3817@option{align=on} is specified then we print a message to the user 3818to inform about the delay. 3819Currently this option does not work when @option{shift} is @code{auto}. 3820Note: The sync algorithm will work for those shift values for which 3821the guest clock runs ahead of the host clock. Typically this happens 3822when the shift value is high (how high depends on the host machine). 3823 3824When @option{rr} option is specified deterministic record/replay is enabled. 3825Replay log is written into @var{filename} file in record mode and 3826read from this file in replay mode. 3827 3828Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3829at the start of execution recording. In replay mode this option is used 3830to load the initial VM state. 3831ETEXI 3832 3833DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3834 "-watchdog model\n" \ 3835 " enable virtual hardware watchdog [default=none]\n", 3836 QEMU_ARCH_ALL) 3837STEXI 3838@item -watchdog @var{model} 3839@findex -watchdog 3840Create a virtual hardware watchdog device. Once enabled (by a guest 3841action), the watchdog must be periodically polled by an agent inside 3842the guest or else the guest will be restarted. Choose a model for 3843which your guest has drivers. 3844 3845The @var{model} is the model of hardware watchdog to emulate. Use 3846@code{-watchdog help} to list available hardware models. Only one 3847watchdog can be enabled for a guest. 3848 3849The following models may be available: 3850@table @option 3851@item ib700 3852iBASE 700 is a very simple ISA watchdog with a single timer. 3853@item i6300esb 3854Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3855dual-timer watchdog. 3856@item diag288 3857A virtual watchdog for s390x backed by the diagnose 288 hypercall 3858(currently KVM only). 3859@end table 3860ETEXI 3861 3862DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3863 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3864 " action when watchdog fires [default=reset]\n", 3865 QEMU_ARCH_ALL) 3866STEXI 3867@item -watchdog-action @var{action} 3868@findex -watchdog-action 3869 3870The @var{action} controls what QEMU will do when the watchdog timer 3871expires. 3872The default is 3873@code{reset} (forcefully reset the guest). 3874Other possible actions are: 3875@code{shutdown} (attempt to gracefully shutdown the guest), 3876@code{poweroff} (forcefully poweroff the guest), 3877@code{inject-nmi} (inject a NMI into the guest), 3878@code{pause} (pause the guest), 3879@code{debug} (print a debug message and continue), or 3880@code{none} (do nothing). 3881 3882Note that the @code{shutdown} action requires that the guest responds 3883to ACPI signals, which it may not be able to do in the sort of 3884situations where the watchdog would have expired, and thus 3885@code{-watchdog-action shutdown} is not recommended for production use. 3886 3887Examples: 3888 3889@table @code 3890@item -watchdog i6300esb -watchdog-action pause 3891@itemx -watchdog ib700 3892@end table 3893ETEXI 3894 3895DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3896 "-echr chr set terminal escape character instead of ctrl-a\n", 3897 QEMU_ARCH_ALL) 3898STEXI 3899 3900@item -echr @var{numeric_ascii_value} 3901@findex -echr 3902Change the escape character used for switching to the monitor when using 3903monitor and serial sharing. The default is @code{0x01} when using the 3904@code{-nographic} option. @code{0x01} is equal to pressing 3905@code{Control-a}. You can select a different character from the ascii 3906control keys where 1 through 26 map to Control-a through Control-z. For 3907instance you could use the either of the following to change the escape 3908character to Control-t. 3909@table @code 3910@item -echr 0x14 3911@itemx -echr 20 3912@end table 3913ETEXI 3914 3915DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3916 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3917STEXI 3918@item -show-cursor 3919@findex -show-cursor 3920Show cursor. 3921ETEXI 3922 3923DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3924 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3925STEXI 3926@item -tb-size @var{n} 3927@findex -tb-size 3928Set TB size. 3929ETEXI 3930 3931DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3932 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3933 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3934 "-incoming unix:socketpath\n" \ 3935 " prepare for incoming migration, listen on\n" \ 3936 " specified protocol and socket address\n" \ 3937 "-incoming fd:fd\n" \ 3938 "-incoming exec:cmdline\n" \ 3939 " accept incoming migration on given file descriptor\n" \ 3940 " or from given external command\n" \ 3941 "-incoming defer\n" \ 3942 " wait for the URI to be specified via migrate_incoming\n", 3943 QEMU_ARCH_ALL) 3944STEXI 3945@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3946@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3947@findex -incoming 3948Prepare for incoming migration, listen on a given tcp port. 3949 3950@item -incoming unix:@var{socketpath} 3951Prepare for incoming migration, listen on a given unix socket. 3952 3953@item -incoming fd:@var{fd} 3954Accept incoming migration from a given filedescriptor. 3955 3956@item -incoming exec:@var{cmdline} 3957Accept incoming migration as an output from specified external command. 3958 3959@item -incoming defer 3960Wait for the URI to be specified via migrate_incoming. The monitor can 3961be used to change settings (such as migration parameters) prior to issuing 3962the migrate_incoming to allow the migration to begin. 3963ETEXI 3964 3965DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3966 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3967STEXI 3968@item -only-migratable 3969@findex -only-migratable 3970Only allow migratable devices. Devices will not be allowed to enter an 3971unmigratable state. 3972ETEXI 3973 3974DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3975 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3976STEXI 3977@item -nodefaults 3978@findex -nodefaults 3979Don't create default devices. Normally, QEMU sets the default devices like serial 3980port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3981CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3982default devices. 3983ETEXI 3984 3985#ifndef _WIN32 3986DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3987 "-chroot dir chroot to dir just before starting the VM\n", 3988 QEMU_ARCH_ALL) 3989#endif 3990STEXI 3991@item -chroot @var{dir} 3992@findex -chroot 3993Immediately before starting guest execution, chroot to the specified 3994directory. Especially useful in combination with -runas. 3995ETEXI 3996 3997#ifndef _WIN32 3998DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3999 "-runas user change to user id user just before starting the VM\n" \ 4000 " user can be numeric uid:gid instead\n", 4001 QEMU_ARCH_ALL) 4002#endif 4003STEXI 4004@item -runas @var{user} 4005@findex -runas 4006Immediately before starting guest execution, drop root privileges, switching 4007to the specified user. 4008ETEXI 4009 4010DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4011 "-prom-env variable=value\n" 4012 " set OpenBIOS nvram variables\n", 4013 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4014STEXI 4015@item -prom-env @var{variable}=@var{value} 4016@findex -prom-env 4017Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4018ETEXI 4019DEF("semihosting", 0, QEMU_OPTION_semihosting, 4020 "-semihosting semihosting mode\n", 4021 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4022 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4023STEXI 4024@item -semihosting 4025@findex -semihosting 4026Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4027ETEXI 4028DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4029 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4030 " semihosting configuration\n", 4031QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4032QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4033STEXI 4034@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4035@findex -semihosting-config 4036Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4037@table @option 4038@item target=@code{native|gdb|auto} 4039Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4040or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4041during debug sessions and @code{native} otherwise. 4042@item chardev=@var{str1} 4043Send the output to a chardev backend output for native or auto output when not in gdb 4044@item arg=@var{str1},arg=@var{str2},... 4045Allows the user to pass input arguments, and can be used multiple times to build 4046up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4047command line is still supported for backward compatibility. If both the 4048@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4049specified, the former is passed to semihosting as it always takes precedence. 4050@end table 4051ETEXI 4052DEF("old-param", 0, QEMU_OPTION_old_param, 4053 "-old-param old param mode\n", QEMU_ARCH_ARM) 4054STEXI 4055@item -old-param 4056@findex -old-param (ARM) 4057Old param mode (ARM only). 4058ETEXI 4059 4060DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4061 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4062 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4063 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4064 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4065 " by the kernel, but typically no longer used by modern\n" \ 4066 " C library implementations.\n" \ 4067 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4068 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4069 " The value 'children' will deny set*uid|gid system calls for\n" \ 4070 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4071 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4072 " blacklisting *fork and execve\n" \ 4073 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4074 QEMU_ARCH_ALL) 4075STEXI 4076@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4077@findex -sandbox 4078Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4079disable it. The default is 'off'. 4080@table @option 4081@item obsolete=@var{string} 4082Enable Obsolete system calls 4083@item elevateprivileges=@var{string} 4084Disable set*uid|gid system calls 4085@item spawn=@var{string} 4086Disable *fork and execve 4087@item resourcecontrol=@var{string} 4088Disable process affinity and schedular priority 4089@end table 4090ETEXI 4091 4092DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4093 "-readconfig <file>\n", QEMU_ARCH_ALL) 4094STEXI 4095@item -readconfig @var{file} 4096@findex -readconfig 4097Read device configuration from @var{file}. This approach is useful when you want to spawn 4098QEMU process with many command line options but you don't want to exceed the command line 4099character limit. 4100ETEXI 4101DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4102 "-writeconfig <file>\n" 4103 " read/write config file\n", QEMU_ARCH_ALL) 4104STEXI 4105@item -writeconfig @var{file} 4106@findex -writeconfig 4107Write device configuration to @var{file}. The @var{file} can be either filename to save 4108command line and device configuration into file or dash @code{-}) character to print the 4109output to stdout. This can be later used as input file for @code{-readconfig} option. 4110ETEXI 4111 4112DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4113 "-no-user-config\n" 4114 " do not load default user-provided config files at startup\n", 4115 QEMU_ARCH_ALL) 4116STEXI 4117@item -no-user-config 4118@findex -no-user-config 4119The @code{-no-user-config} option makes QEMU not load any of the user-provided 4120config files on @var{sysconfdir}. 4121ETEXI 4122 4123DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4124 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4125 " specify tracing options\n", 4126 QEMU_ARCH_ALL) 4127STEXI 4128HXCOMM This line is not accurate, as some sub-options are backend-specific but 4129HXCOMM HX does not support conditional compilation of text. 4130@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4131@findex -trace 4132@include qemu-option-trace.texi 4133ETEXI 4134 4135HXCOMM Internal use 4136DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4137DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4138 4139#ifdef __linux__ 4140DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4141 "-enable-fips enable FIPS 140-2 compliance\n", 4142 QEMU_ARCH_ALL) 4143#endif 4144STEXI 4145@item -enable-fips 4146@findex -enable-fips 4147Enable FIPS 140-2 compliance mode. 4148ETEXI 4149 4150HXCOMM Deprecated by -machine accel=tcg property 4151DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4152 4153DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4154 "-msg timestamp[=on|off]\n" 4155 " change the format of messages\n" 4156 " on|off controls leading timestamps (default:on)\n", 4157 QEMU_ARCH_ALL) 4158STEXI 4159@item -msg timestamp[=on|off] 4160@findex -msg 4161prepend a timestamp to each log message.(default:on) 4162ETEXI 4163 4164DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4165 "-dump-vmstate <file>\n" 4166 " Output vmstate information in JSON format to file.\n" 4167 " Use the scripts/vmstate-static-checker.py file to\n" 4168 " check for possible regressions in migration code\n" 4169 " by comparing two such vmstate dumps.\n", 4170 QEMU_ARCH_ALL) 4171STEXI 4172@item -dump-vmstate @var{file} 4173@findex -dump-vmstate 4174Dump json-encoded vmstate information for current machine type to file 4175in @var{file} 4176ETEXI 4177 4178DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4179 "-enable-sync-profile\n" 4180 " enable synchronization profiling\n", 4181 QEMU_ARCH_ALL) 4182STEXI 4183@item -enable-sync-profile 4184@findex -enable-sync-profile 4185Enable synchronization profiling. 4186ETEXI 4187 4188STEXI 4189@end table 4190ETEXI 4191DEFHEADING() 4192 4193DEFHEADING(Generic object creation:) 4194STEXI 4195@table @option 4196ETEXI 4197 4198DEF("object", HAS_ARG, QEMU_OPTION_object, 4199 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4200 " create a new object of type TYPENAME setting properties\n" 4201 " in the order they are specified. Note that the 'id'\n" 4202 " property must be set. These objects are placed in the\n" 4203 " '/objects' path.\n", 4204 QEMU_ARCH_ALL) 4205STEXI 4206@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4207@findex -object 4208Create a new object of type @var{typename} setting properties 4209in the order they are specified. Note that the 'id' 4210property must be set. These objects are placed in the 4211'/objects' path. 4212 4213@table @option 4214 4215@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} 4216 4217Creates a memory file backend object, which can be used to back 4218the guest RAM with huge pages. 4219 4220The @option{id} parameter is a unique ID that will be used to reference this 4221memory region when configuring the @option{-numa} argument. 4222 4223The @option{size} option provides the size of the memory region, and accepts 4224common suffixes, eg @option{500M}. 4225 4226The @option{mem-path} provides the path to either a shared memory or huge page 4227filesystem mount. 4228 4229The @option{share} boolean option determines whether the memory 4230region is marked as private to QEMU, or shared. The latter allows 4231a co-operating external process to access the QEMU memory region. 4232 4233The @option{share} is also required for pvrdma devices due to 4234limitations in the RDMA API provided by Linux. 4235 4236Setting share=on might affect the ability to configure NUMA 4237bindings for the memory backend under some circumstances, see 4238Documentation/vm/numa_memory_policy.txt on the Linux kernel 4239source tree for additional details. 4240 4241Setting the @option{discard-data} boolean option to @var{on} 4242indicates that file contents can be destroyed when QEMU exits, 4243to avoid unnecessarily flushing data to the backing file. Note 4244that @option{discard-data} is only an optimization, and QEMU 4245might not discard file contents if it aborts unexpectedly or is 4246terminated using SIGKILL. 4247 4248The @option{merge} boolean option enables memory merge, also known as 4249MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4250memory deduplication. 4251 4252Setting the @option{dump} boolean option to @var{off} excludes the memory from 4253core dumps. This feature is also known as MADV_DONTDUMP. 4254 4255The @option{prealloc} boolean option enables memory preallocation. 4256 4257The @option{host-nodes} option binds the memory range to a list of NUMA host 4258nodes. 4259 4260The @option{policy} option sets the NUMA policy to one of the following values: 4261 4262@table @option 4263@item @var{default} 4264default host policy 4265 4266@item @var{preferred} 4267prefer the given host node list for allocation 4268 4269@item @var{bind} 4270restrict memory allocation to the given host node list 4271 4272@item @var{interleave} 4273interleave memory allocations across the given host node list 4274@end table 4275 4276The @option{align} option specifies the base address alignment when 4277QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4278@option{2M}. Some backend store specified by @option{mem-path} 4279requires an alignment different than the default one used by QEMU, eg 4280the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4281such cases, users can specify the required alignment via this option. 4282 4283The @option{pmem} option specifies whether the backing file specified 4284by @option{mem-path} is in host persistent memory that can be accessed 4285using the SNIA NVM programming model (e.g. Intel NVDIMM). 4286If @option{pmem} is set to 'on', QEMU will take necessary operations to 4287guarantee the persistence of its own writes to @option{mem-path} 4288(e.g. in vNVDIMM label emulation and live migration). 4289Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4290file metadata is in sync for @option{mem-path} in case of host crash 4291or a power failure. MAP_SYNC requires support from both the host kernel 4292(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4293with DAX option. 4294 4295@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} 4296 4297Creates a memory backend object, which can be used to back the guest RAM. 4298Memory backend objects offer more control than the @option{-m} option that is 4299traditionally used to define guest RAM. Please refer to 4300@option{memory-backend-file} for a description of the options. 4301 4302@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} 4303 4304Creates an anonymous memory file backend object, which allows QEMU to 4305share the memory with an external process (e.g. when using 4306vhost-user). The memory is allocated with memfd and optional 4307sealing. (Linux only) 4308 4309The @option{seal} option creates a sealed-file, that will block 4310further resizing the memory ('on' by default). 4311 4312The @option{hugetlb} option specify the file to be created resides in 4313the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4314the @option{hugetlb} option, the @option{hugetlbsize} option specify 4315the hugetlb page size on systems that support multiple hugetlb page 4316sizes (it must be a power of 2 value supported by the system). 4317 4318In some versions of Linux, the @option{hugetlb} option is incompatible 4319with the @option{seal} option (requires at least Linux 4.16). 4320 4321Please refer to @option{memory-backend-file} for a description of the 4322other options. 4323 4324The @option{share} boolean option is @var{on} by default with memfd. 4325 4326@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4327 4328Creates a random number generator backend which obtains entropy from 4329a device on the host. The @option{id} parameter is a unique ID that 4330will be used to reference this entropy backend from the @option{virtio-rng} 4331device. The @option{filename} parameter specifies which file to obtain 4332entropy from and if omitted defaults to @option{/dev/urandom}. 4333 4334@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4335 4336Creates a random number generator backend which obtains entropy from 4337an external daemon running on the host. The @option{id} parameter is 4338a unique ID that will be used to reference this entropy backend from 4339the @option{virtio-rng} device. The @option{chardev} parameter is 4340the unique ID of a character device backend that provides the connection 4341to the RNG daemon. 4342 4343@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4344 4345Creates a TLS anonymous credentials object, which can be used to provide 4346TLS support on network backends. The @option{id} parameter is a unique 4347ID which network backends will use to access the credentials. The 4348@option{endpoint} is either @option{server} or @option{client} depending 4349on whether the QEMU network backend that uses the credentials will be 4350acting as a client or as a server. If @option{verify-peer} is enabled 4351(the default) then once the handshake is completed, the peer credentials 4352will be verified, though this is a no-op for anonymous credentials. 4353 4354The @var{dir} parameter tells QEMU where to find the credential 4355files. For server endpoints, this directory may contain a file 4356@var{dh-params.pem} providing diffie-hellman parameters to use 4357for the TLS server. If the file is missing, QEMU will generate 4358a set of DH parameters at startup. This is a computationally 4359expensive operation that consumes random pool entropy, so it is 4360recommended that a persistent set of parameters be generated 4361upfront and saved. 4362 4363@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4364 4365Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4366TLS support on network backends. The @option{id} parameter is a unique 4367ID which network backends will use to access the credentials. The 4368@option{endpoint} is either @option{server} or @option{client} depending 4369on whether the QEMU network backend that uses the credentials will be 4370acting as a client or as a server. For clients only, @option{username} 4371is the username which will be sent to the server. If omitted 4372it defaults to ``qemu''. 4373 4374The @var{dir} parameter tells QEMU where to find the keys file. 4375It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4376pairs. This file can most easily be created using the GnuTLS 4377@code{psktool} program. 4378 4379For server endpoints, @var{dir} may also contain a file 4380@var{dh-params.pem} providing diffie-hellman parameters to use 4381for the TLS server. If the file is missing, QEMU will generate 4382a set of DH parameters at startup. This is a computationally 4383expensive operation that consumes random pool entropy, so it is 4384recommended that a persistent set of parameters be generated 4385up front and saved. 4386 4387@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} 4388 4389Creates a TLS anonymous credentials object, which can be used to provide 4390TLS support on network backends. The @option{id} parameter is a unique 4391ID which network backends will use to access the credentials. The 4392@option{endpoint} is either @option{server} or @option{client} depending 4393on whether the QEMU network backend that uses the credentials will be 4394acting as a client or as a server. If @option{verify-peer} is enabled 4395(the default) then once the handshake is completed, the peer credentials 4396will be verified. With x509 certificates, this implies that the clients 4397must be provided with valid client certificates too. 4398 4399The @var{dir} parameter tells QEMU where to find the credential 4400files. For server endpoints, this directory may contain a file 4401@var{dh-params.pem} providing diffie-hellman parameters to use 4402for the TLS server. If the file is missing, QEMU will generate 4403a set of DH parameters at startup. This is a computationally 4404expensive operation that consumes random pool entropy, so it is 4405recommended that a persistent set of parameters be generated 4406upfront and saved. 4407 4408For x509 certificate credentials the directory will contain further files 4409providing the x509 certificates. The certificates must be stored 4410in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4411@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4412@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4413 4414For the @var{server-key.pem} and @var{client-key.pem} files which 4415contain sensitive private keys, it is possible to use an encrypted 4416version by providing the @var{passwordid} parameter. This provides 4417the ID of a previously created @code{secret} object containing the 4418password for decryption. 4419 4420The @var{priority} parameter allows to override the global default 4421priority used by gnutls. This can be useful if the system administrator 4422needs to use a weaker set of crypto priorities for QEMU without 4423potentially forcing the weakness onto all applications. Or conversely 4424if one wants wants a stronger default for QEMU than for all other 4425applications, they can do this through this parameter. Its format is 4426a gnutls priority string as described at 4427@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4428 4429@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4430 4431Interval @var{t} can't be 0, this filter batches the packet delivery: all 4432packets arriving in a given interval on netdev @var{netdevid} are delayed 4433until the end of the interval. Interval is in microseconds. 4434@option{status} is optional that indicate whether the netfilter is 4435on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4436 4437queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4438 4439@option{all}: the filter is attached both to the receive and the transmit 4440 queue of the netdev (default). 4441 4442@option{rx}: the filter is attached to the receive queue of the netdev, 4443 where it will receive packets sent to the netdev. 4444 4445@option{tx}: the filter is attached to the transmit queue of the netdev, 4446 where it will receive packets sent by the netdev. 4447 4448@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4449 4450filter-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. 4451 4452@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4453 4454filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4455@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4456filter-redirector will redirect packet with vnet_hdr_len. 4457Create a filter-redirector we need to differ outdev id from indev id, id can not 4458be the same. we can just use indev or outdev, but at least one of indev or outdev 4459need to be specified. 4460 4461@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4462 4463Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4464secondary from primary to keep secondary tcp connection,and rewrite 4465tcp packet to primary from secondary make tcp packet can be handled by 4466client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4467 4468usage: 4469colo secondary: 4470-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4471-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4472-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4473 4474@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4475 4476Dump the network traffic on netdev @var{dev} to the file specified by 4477@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4478The file format is libpcap, so it can be analyzed with tools such as tcpdump 4479or Wireshark. 4480 4481@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}] 4482 4483Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4484secondary packet. If the packets are same, we will output primary 4485packet to outdev@var{chardevid}, else we will notify colo-frame 4486do checkpoint and send primary packet to outdev@var{chardevid}. 4487In order to improve efficiency, we need to put the task of comparison 4488in another thread. If it has the vnet_hdr_support flag, colo compare 4489will send/recv packet with vnet_hdr_len. 4490If you want to use Xen COLO, will need the notify_dev to notify Xen 4491colo-frame to do checkpoint. 4492 4493we must use it with the help of filter-mirror and filter-redirector. 4494 4495@example 4496 4497KVM COLO 4498 4499primary: 4500-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4501-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4502-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4503-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4504-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4505-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4506-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4507-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4508-object iothread,id=iothread1 4509-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4510-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4511-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4512-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4513 4514secondary: 4515-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4516-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4517-chardev socket,id=red0,host=3.3.3.3,port=9003 4518-chardev socket,id=red1,host=3.3.3.3,port=9004 4519-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4520-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4521 4522 4523Xen COLO 4524 4525primary: 4526-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4527-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4528-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4529-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4530-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4531-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4532-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4533-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4534-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4535-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4536-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4537-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4538-object iothread,id=iothread1 4539-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4540 4541secondary: 4542-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4543-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4544-chardev socket,id=red0,host=3.3.3.3,port=9003 4545-chardev socket,id=red1,host=3.3.3.3,port=9004 4546-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4547-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4548 4549@end example 4550 4551If you want to know the detail of above command line, you can read 4552the colo-compare git log. 4553 4554@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4555 4556Creates a cryptodev backend which executes crypto opreation from 4557the QEMU cipher APIS. The @var{id} parameter is 4558a unique ID that will be used to reference this cryptodev backend from 4559the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4560which specify the queue number of cryptodev backend, the default of 4561@var{queues} is 1. 4562 4563@example 4564 4565 # qemu-system-x86_64 \ 4566 [...] \ 4567 -object cryptodev-backend-builtin,id=cryptodev0 \ 4568 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4569 [...] 4570@end example 4571 4572@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4573 4574Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4575The @var{id} parameter is a unique ID that will be used to reference this 4576cryptodev backend from the @option{virtio-crypto} device. 4577The chardev should be a unix domain socket backed one. The vhost-user uses 4578a specifically defined protocol to pass vhost ioctl replacement messages 4579to an application on the other end of the socket. 4580The @var{queues} parameter is optional, which specify the queue number 4581of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4582 4583@example 4584 4585 # qemu-system-x86_64 \ 4586 [...] \ 4587 -chardev socket,id=chardev0,path=/path/to/socket \ 4588 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4589 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4590 [...] 4591@end example 4592 4593@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4594@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4595 4596Defines a secret to store a password, encryption key, or some other sensitive 4597data. The sensitive data can either be passed directly via the @var{data} 4598parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4599parameter is insecure unless the sensitive data is encrypted. 4600 4601The sensitive data can be provided in raw format (the default), or base64. 4602When encoded as JSON, the raw format only supports valid UTF-8 characters, 4603so base64 is recommended for sending binary data. QEMU will convert from 4604which ever format is provided to the format it needs internally. eg, an 4605RBD password can be provided in raw format, even though it will be base64 4606encoded when passed onto the RBD sever. 4607 4608For added protection, it is possible to encrypt the data associated with 4609a secret using the AES-256-CBC cipher. Use of encryption is indicated 4610by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4611parameter provides the ID of a previously defined secret that contains 4612the AES-256 decryption key. This key should be 32-bytes long and be 4613base64 encoded. The @var{iv} parameter provides the random initialization 4614vector used for encryption of this particular secret and should be a 4615base64 encrypted string of the 16-byte IV. 4616 4617The simplest (insecure) usage is to provide the secret inline 4618 4619@example 4620 4621 # $QEMU -object secret,id=sec0,data=letmein,format=raw 4622 4623@end example 4624 4625The simplest secure usage is to provide the secret via a file 4626 4627 # printf "letmein" > mypasswd.txt 4628 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 4629 4630For greater security, AES-256-CBC should be used. To illustrate usage, 4631consider the openssl command line tool which can encrypt the data. Note 4632that when encrypting, the plaintext must be padded to the cipher block 4633size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4634 4635First a master key needs to be created in base64 encoding: 4636 4637@example 4638 # openssl rand -base64 32 > key.b64 4639 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4640@end example 4641 4642Each secret to be encrypted needs to have a random initialization vector 4643generated. These do not need to be kept secret 4644 4645@example 4646 # openssl rand -base64 16 > iv.b64 4647 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4648@end example 4649 4650The secret to be defined can now be encrypted, in this case we're 4651telling openssl to base64 encode the result, but it could be left 4652as raw bytes if desired. 4653 4654@example 4655 # SECRET=$(printf "letmein" | 4656 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4657@end example 4658 4659When launching QEMU, create a master secret pointing to @code{key.b64} 4660and specify that to be used to decrypt the user password. Pass the 4661contents of @code{iv.b64} to the second secret 4662 4663@example 4664 # $QEMU \ 4665 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4666 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4667 data=$SECRET,iv=$(<iv.b64) 4668@end example 4669 4670@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}] 4671 4672Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4673to provide the guest memory encryption support on AMD processors. 4674 4675When memory encryption is enabled, one of the physical address bit (aka the 4676C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4677is used to provide the C-bit position. The C-bit position is Host family dependent 4678hence user must provide this value. On EPYC, the value should be 47. 4679 4680When memory encryption is enabled, we loose certain bits in physical address space. 4681The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4682physical address space. Similar to C-bit, the value is Host family dependent. 4683On EPYC, the value should be 5. 4684 4685The @option{sev-device} provides the device file to use for communicating with 4686the SEV firmware running inside AMD Secure Processor. The default device is 4687'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4688created by CCP driver. 4689 4690The @option{policy} provides the guest policy to be enforced by the SEV firmware 4691and restrict what configuration and operational commands can be performed on this 4692guest by the hypervisor. The policy should be provided by the guest owner and is 4693bound to the guest and cannot be changed throughout the lifetime of the guest. 4694The default is 0. 4695 4696If guest @option{policy} allows sharing the key with another SEV guest then 4697@option{handle} can be use to provide handle of the guest from which to share 4698the key. 4699 4700The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4701Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4702are used for establishing a cryptographic session with the guest owner to 4703negotiate keys used for attestation. The file must be encoded in base64. 4704 4705e.g to launch a SEV guest 4706@example 4707 # $QEMU \ 4708 ...... 4709 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4710 -machine ...,memory-encryption=sev0 4711 ..... 4712 4713@end example 4714 4715 4716@item -object authz-simple,id=@var{id},identity=@var{string} 4717 4718Create an authorization object that will control access to network services. 4719 4720The @option{identity} parameter is identifies the user and its format 4721depends on the network service that authorization object is associated 4722with. For authorizing based on TLS x509 certificates, the identity must 4723be the x509 distinguished name. Note that care must be taken to escape 4724any commas in the distinguished name. 4725 4726An example authorization object to validate a x509 distinguished name 4727would look like: 4728@example 4729 # $QEMU \ 4730 ... 4731 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4732 ... 4733@end example 4734 4735Note the use of quotes due to the x509 distinguished name containing 4736whitespace, and escaping of ','. 4737 4738@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4739 4740Create an authorization object that will control access to network services. 4741 4742The @option{filename} parameter is the fully qualified path to a file 4743containing the access control list rules in JSON format. 4744 4745An example set of rules that match against SASL usernames might look 4746like: 4747 4748@example 4749 @{ 4750 "rules": [ 4751 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4752 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4753 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4754 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4755 ], 4756 "policy": "deny" 4757 @} 4758@end example 4759 4760When checking access the object will iterate over all the rules and 4761the first rule to match will have its @option{policy} value returned 4762as the result. If no rules match, then the default @option{policy} 4763value is returned. 4764 4765The rules can either be an exact string match, or they can use the 4766simple UNIX glob pattern matching to allow wildcards to be used. 4767 4768If @option{refresh} is set to true the file will be monitored 4769and automatically reloaded whenever its content changes. 4770 4771As with the @code{authz-simple} object, the format of the identity 4772strings being matched depends on the network service, but is usually 4773a TLS x509 distinguished name, or a SASL username. 4774 4775An example authorization object to validate a SASL username 4776would look like: 4777@example 4778 # $QEMU \ 4779 ... 4780 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4781 ... 4782@end example 4783 4784@item -object authz-pam,id=@var{id},service=@var{string} 4785 4786Create an authorization object that will control access to network services. 4787 4788The @option{service} parameter provides the name of a PAM service to use 4789for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4790exist to provide the configuration for the @code{account} subsystem. 4791 4792An example authorization object to validate a TLS x509 distinguished 4793name would look like: 4794 4795@example 4796 # $QEMU \ 4797 ... 4798 -object authz-pam,id=auth0,service=qemu-vnc 4799 ... 4800@end example 4801 4802There would then be a corresponding config file for PAM at 4803@code{/etc/pam.d/qemu-vnc} that contains: 4804 4805@example 4806account requisite pam_listfile.so item=user sense=allow \ 4807 file=/etc/qemu/vnc.allow 4808@end example 4809 4810Finally the @code{/etc/qemu/vnc.allow} file would contain 4811the list of x509 distingished names that are permitted 4812access 4813 4814@example 4815CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4816@end example 4817 4818 4819@end table 4820 4821ETEXI 4822 4823 4824HXCOMM This is the last statement. Insert new options before this line! 4825STEXI 4826@end table 4827ETEXI 4828
