1HXCOMM Use DEFHEADING() to define headings in both help text and texi 2HXCOMM Text between STEXI and ETEXI are copied to texi version and 3HXCOMM discarded from C version 4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to 5HXCOMM construct option structures, enums and help message for specified 6HXCOMM architectures. 7HXCOMM HXCOMM can be used for comments, discarded from both texi and C 8 9DEFHEADING(Standard options:) 10STEXI 11@table @option 12ETEXI 13 14DEF("help", 0, QEMU_OPTION_h, 15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 16STEXI 17@item -h 18@findex -h 19Display help and exit 20ETEXI 21 22DEF("version", 0, QEMU_OPTION_version, 23 "-version display version information and exit\n", QEMU_ARCH_ALL) 24STEXI 25@item -version 26@findex -version 27Display version information and exit 28ETEXI 29 30DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 31 "-machine [type=]name[,prop[=value][,...]]\n" 32 " selects emulated machine ('-machine help' for list)\n" 33 " property accel=accel1[:accel2[:...]] selects accelerator\n" 34 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n" 35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" 36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n" 38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 39 " mem-merge=on|off controls memory merge support (default: on)\n" 40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 44 " nvdimm=on|off controls NVDIMM support (default=off)\n" 45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 46 " memory-encryption=@var{} memory encryption object to use (default=none)\n", 47 QEMU_ARCH_ALL) 48STEXI 49@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 50@findex -machine 51Select the emulated machine by @var{name}. Use @code{-machine help} to list 52available machines. 53 54For architectures which aim to support live migration compatibility 55across releases, each release will introduce a new versioned machine 56type. For example, the 2.8.0 release introduced machine types 57``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. 58 59To allow live migration of guests from QEMU version 2.8.0, to QEMU 60version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' 61and ``pc-q35-2.8'' machines too. To allow users live migrating VMs 62to skip multiple intermediate releases when upgrading, new releases 63of QEMU will support machine types from many previous versions. 64 65Supported machine properties are: 66@table @option 67@item accel=@var{accels1}[:@var{accels2}[:...]] 68This is used to enable an accelerator. Depending on the target architecture, 69kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 70more than one accelerator specified, the next one is used if the previous one 71fails to initialize. 72@item kernel_irqchip=on|off 73Controls in-kernel irqchip support for the chosen accelerator when available. 74@item gfx_passthru=on|off 75Enables IGD GFX passthrough support for the chosen machine when available. 76@item vmport=on|off|auto 77Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 78value based on accel. For accel=xen the default is off otherwise the default 79is on. 80@item kvm_shadow_mem=size 81Defines the size of the KVM shadow MMU. 82@item dump-guest-core=on|off 83Include guest memory in a core dump. The default is on. 84@item mem-merge=on|off 85Enables or disables memory merge support. This feature, when supported by 86the host, de-duplicates identical memory pages among VMs instances 87(enabled by default). 88@item aes-key-wrap=on|off 89Enables or disables AES key wrapping support on s390-ccw hosts. This feature 90controls whether AES wrapping keys will be created to allow 91execution of AES cryptographic functions. The default is on. 92@item dea-key-wrap=on|off 93Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 94controls whether DEA wrapping keys will be created to allow 95execution of DEA cryptographic functions. The default is on. 96@item nvdimm=on|off 97Enables or disables NVDIMM support. The default is off. 98@item enforce-config-section=on|off 99If @option{enforce-config-section} is set to @var{on}, force migration 100code to send configuration section even if the machine-type sets the 101@option{migration.send-configuration} property to @var{off}. 102NOTE: this parameter is deprecated. Please use @option{-global} 103@option{migration.send-configuration}=@var{on|off} instead. 104@item memory-encryption=@var{} 105Memory encryption object to use. The default is none. 106@end table 107ETEXI 108 109HXCOMM Deprecated by -machine 110DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 111 112DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 114STEXI 115@item -cpu @var{model} 116@findex -cpu 117Select CPU model (@code{-cpu help} for list and additional feature selection) 118ETEXI 119 120DEF("accel", HAS_ARG, QEMU_OPTION_accel, 121 "-accel [accel=]accelerator[,thread=single|multi]\n" 122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 123 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 124STEXI 125@item -accel @var{name}[,prop=@var{value}[,...]] 126@findex -accel 127This is used to enable an accelerator. Depending on the target architecture, 128kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 129more than one accelerator specified, the next one is used if the previous one 130fails to initialize. 131@table @option 132@item thread=single|multi 133Controls number of TCG threads. When the TCG is multi-threaded there will be one 134thread per vCPU therefor taking advantage of additional host cores. The default 135is to enable multi-threading where both the back-end and front-ends support it and 136no incompatible TCG features have been enabled (e.g. icount/replay). 137@end table 138ETEXI 139 140DEF("smp", HAS_ARG, QEMU_OPTION_smp, 141 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n" 142 " set the number of CPUs to 'n' [default=1]\n" 143 " maxcpus= maximum number of total cpus, including\n" 144 " offline CPUs for hotplug, etc\n" 145 " cores= number of CPU cores on one socket (for PC, it's on one die)\n" 146 " threads= number of threads on one CPU core\n" 147 " dies= number of CPU dies on one socket (for PC only)\n" 148 " sockets= number of discrete sockets in the system\n", 149 QEMU_ARCH_ALL) 150STEXI 151@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,dies=dies][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 152@findex -smp 153Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 154CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 155to 4. 156For the PC target, the number of @var{cores} per die, the number of @var{threads} 157per cores, the number of @var{dies} per packages and the total number of 158@var{sockets} can be specified. Missing values will be computed. 159If any on the three values is given, the total number of CPUs @var{n} can be omitted. 160@var{maxcpus} specifies the maximum number of hotpluggable CPUs. 161ETEXI 162 163DEF("numa", HAS_ARG, QEMU_OPTION_numa, 164 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 165 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 166 "-numa dist,src=source,dst=destination,val=distance\n" 167 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n", 168 QEMU_ARCH_ALL) 169STEXI 170@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 171@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 172@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 173@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 174@findex -numa 175Define a NUMA node and assign RAM and VCPUs to it. 176Set the NUMA distance from a source node to a destination node. 177 178Legacy VCPU assignment uses @samp{cpus} option where 179@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 180@samp{cpus} option represent a contiguous range of CPU indexes 181(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 182set of VCPUs can be represented by providing multiple @samp{cpus} 183options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 184split between them. 185 186For example, the following option assigns VCPUs 0, 1, 2 and 5 to 187a NUMA node: 188@example 189-numa node,cpus=0-2,cpus=5 190@end example 191 192@samp{cpu} option is a new alternative to @samp{cpus} option 193which uses @samp{socket-id|core-id|thread-id} properties to assign 194CPU objects to a @var{node} using topology layout properties of CPU. 195The set of properties is machine specific, and depends on used 196machine type/@samp{smp} options. It could be queried with 197@samp{hotpluggable-cpus} monitor command. 198@samp{node-id} property specifies @var{node} to which CPU object 199will be assigned, it's required for @var{node} to be declared 200with @samp{node} option before it's used with @samp{cpu} option. 201 202For example: 203@example 204-M pc \ 205-smp 1,sockets=2,maxcpus=2 \ 206-numa node,nodeid=0 -numa node,nodeid=1 \ 207-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 208@end example 209 210@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 211assigns RAM from a given memory backend device to a node. If 212@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 213split equally between them. 214 215@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 216if one node uses @samp{memdev}, all of them have to use it. 217 218@var{source} and @var{destination} are NUMA node IDs. 219@var{distance} is the NUMA distance from @var{source} to @var{destination}. 220The distance from a node to itself is always 10. If any pair of nodes is 221given a distance, then all pairs must be given distances. Although, when 222distances are only given in one direction for each pair of nodes, then 223the distances in the opposite directions are assumed to be the same. If, 224however, an asymmetrical pair of distances is given for even one node 225pair, then all node pairs must be provided distance values for both 226directions, even when they are symmetrical. When a node is unreachable 227from another node, set the pair's distance to 255. 228 229Note that the -@option{numa} option doesn't allocate any of the 230specified resources, it just assigns existing resources to NUMA 231nodes. This means that one still has to use the @option{-m}, 232@option{-smp} options to allocate RAM and VCPUs respectively. 233 234ETEXI 235 236DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 237 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 238 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 239STEXI 240@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 241@findex -add-fd 242 243Add a file descriptor to an fd set. Valid options are: 244 245@table @option 246@item fd=@var{fd} 247This option defines the file descriptor of which a duplicate is added to fd set. 248The file descriptor cannot be stdin, stdout, or stderr. 249@item set=@var{set} 250This option defines the ID of the fd set to add the file descriptor to. 251@item opaque=@var{opaque} 252This option defines a free-form string that can be used to describe @var{fd}. 253@end table 254 255You can open an image using pre-opened file descriptors from an fd set: 256@example 257@value{qemu_system} \ 258 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 259 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 260 -drive file=/dev/fdset/2,index=0,media=disk 261@end example 262ETEXI 263 264DEF("set", HAS_ARG, QEMU_OPTION_set, 265 "-set group.id.arg=value\n" 266 " set <arg> parameter for item <id> of type <group>\n" 267 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 268STEXI 269@item -set @var{group}.@var{id}.@var{arg}=@var{value} 270@findex -set 271Set parameter @var{arg} for item @var{id} of type @var{group} 272ETEXI 273 274DEF("global", HAS_ARG, QEMU_OPTION_global, 275 "-global driver.property=value\n" 276 "-global driver=driver,property=property,value=value\n" 277 " set a global default for a driver property\n", 278 QEMU_ARCH_ALL) 279STEXI 280@item -global @var{driver}.@var{prop}=@var{value} 281@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 282@findex -global 283Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 284 285@example 286@value{qemu_system_x86} -global ide-hd.physical_block_size=4096 disk-image.img 287@end example 288 289In particular, you can use this to set driver properties for devices which are 290created automatically by the machine model. To create a device which is not 291created automatically and set properties on it, use -@option{device}. 292 293-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 294driver=@var{driver},property=@var{prop},value=@var{value}. The 295longhand syntax works even when @var{driver} contains a dot. 296ETEXI 297 298DEF("boot", HAS_ARG, QEMU_OPTION_boot, 299 "-boot [order=drives][,once=drives][,menu=on|off]\n" 300 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 301 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 302 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 303 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 304 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 305 QEMU_ARCH_ALL) 306STEXI 307@item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off] 308@findex -boot 309Specify boot order @var{drives} as a string of drive letters. Valid 310drive letters depend on the target architecture. The x86 PC uses: a, b 311(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 312from network adapter 1-4), hard disk boot is the default. To apply a 313particular boot order only on the first startup, specify it via 314@option{once}. Note that the @option{order} or @option{once} parameter 315should not be used together with the @option{bootindex} property of 316devices, since the firmware implementations normally do not support both 317at the same time. 318 319Interactive boot menus/prompts can be enabled via @option{menu=on} as far 320as firmware/BIOS supports them. The default is non-interactive boot. 321 322A splash picture could be passed to bios, enabling user to show it as logo, 323when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 324supports them. Currently Seabios for X86 system support it. 325limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 326format(true color). The resolution should be supported by the SVGA mode, so 327the recommended is 320x240, 640x480, 800x640. 328 329A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 330when boot failed, then reboot. If @option{reboot-timeout} is not set, 331guest will not reboot by default. Currently Seabios for X86 332system support it. 333 334Do strict boot via @option{strict=on} as far as firmware/BIOS 335supports it. This only effects when boot priority is changed by 336bootindex options. The default is non-strict boot. 337 338@example 339# try to boot from network first, then from hard disk 340@value{qemu_system_x86} -boot order=nc 341# boot from CD-ROM first, switch back to default order after reboot 342@value{qemu_system_x86} -boot once=d 343# boot with a splash picture for 5 seconds. 344@value{qemu_system_x86} -boot menu=on,splash=/root/boot.bmp,splash-time=5000 345@end example 346 347Note: The legacy format '-boot @var{drives}' is still supported but its 348use is discouraged as it may be removed from future versions. 349ETEXI 350 351DEF("m", HAS_ARG, QEMU_OPTION_m, 352 "-m [size=]megs[,slots=n,maxmem=size]\n" 353 " configure guest RAM\n" 354 " size: initial amount of guest memory\n" 355 " slots: number of hotplug slots (default: none)\n" 356 " maxmem: maximum amount of guest memory (default: none)\n" 357 "NOTE: Some architectures might enforce a specific granularity\n", 358 QEMU_ARCH_ALL) 359STEXI 360@item -m [size=]@var{megs}[,slots=n,maxmem=size] 361@findex -m 362Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 363Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 364megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 365could be used to set amount of hotpluggable memory slots and maximum amount of 366memory. Note that @var{maxmem} must be aligned to the page size. 367 368For example, the following command-line sets the guest startup RAM size to 3691GB, creates 3 slots to hotplug additional memory and sets the maximum 370memory the guest can reach to 4GB: 371 372@example 373@value{qemu_system} -m 1G,slots=3,maxmem=4G 374@end example 375 376If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 377be enabled and the guest startup RAM will never increase. 378ETEXI 379 380DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 381 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 382STEXI 383@item -mem-path @var{path} 384@findex -mem-path 385Allocate guest RAM from a temporarily created file in @var{path}. 386ETEXI 387 388DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 389 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 390 QEMU_ARCH_ALL) 391STEXI 392@item -mem-prealloc 393@findex -mem-prealloc 394Preallocate memory when using -mem-path. 395ETEXI 396 397DEF("k", HAS_ARG, QEMU_OPTION_k, 398 "-k language use keyboard layout (for example 'fr' for French)\n", 399 QEMU_ARCH_ALL) 400STEXI 401@item -k @var{language} 402@findex -k 403Use keyboard layout @var{language} (for example @code{fr} for 404French). This option is only needed where it is not easy to get raw PC 405keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 406display). You don't normally need to use it on PC/Linux or PC/Windows 407hosts. 408 409The available layouts are: 410@example 411ar de-ch es fo fr-ca hu ja mk no pt-br sv 412da en-gb et fr fr-ch is lt nl pl ru th 413de en-us fi fr-be hr it lv nl-be pt sl tr 414@end example 415 416The default is @code{en-us}. 417ETEXI 418 419 420HXCOMM Deprecated by -audiodev 421DEF("audio-help", 0, QEMU_OPTION_audio_help, 422 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 423 QEMU_ARCH_ALL) 424STEXI 425@item -audio-help 426@findex -audio-help 427Will show the -audiodev equivalent of the currently specified 428(deprecated) environment variables. 429ETEXI 430 431DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 432 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 433 " specifies the audio backend to use\n" 434 " id= identifier of the backend\n" 435 " timer-period= timer period in microseconds\n" 436 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 437 " in|out.fixed-settings= use fixed settings for host audio\n" 438 " in|out.frequency= frequency to use with fixed settings\n" 439 " in|out.channels= number of channels to use with fixed settings\n" 440 " in|out.format= sample format to use with fixed settings\n" 441 " valid values: s8, s16, s32, u8, u16, u32\n" 442 " in|out.voices= number of voices to use\n" 443 " in|out.buffer-length= length of buffer in microseconds\n" 444 "-audiodev none,id=id,[,prop[=value][,...]]\n" 445 " dummy driver that discards all output\n" 446#ifdef CONFIG_AUDIO_ALSA 447 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 448 " in|out.dev= name of the audio device to use\n" 449 " in|out.period-length= length of period in microseconds\n" 450 " in|out.try-poll= attempt to use poll mode\n" 451 " threshold= threshold (in microseconds) when playback starts\n" 452#endif 453#ifdef CONFIG_AUDIO_COREAUDIO 454 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 455 " in|out.buffer-count= number of buffers\n" 456#endif 457#ifdef CONFIG_AUDIO_DSOUND 458 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 459 " latency= add extra latency to playback in microseconds\n" 460#endif 461#ifdef CONFIG_AUDIO_OSS 462 "-audiodev oss,id=id[,prop[=value][,...]]\n" 463 " in|out.dev= path of the audio device to use\n" 464 " in|out.buffer-count= number of buffers\n" 465 " in|out.try-poll= attempt to use poll mode\n" 466 " try-mmap= try using memory mapped access\n" 467 " exclusive= open device in exclusive mode\n" 468 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 469#endif 470#ifdef CONFIG_AUDIO_PA 471 "-audiodev pa,id=id[,prop[=value][,...]]\n" 472 " server= PulseAudio server address\n" 473 " in|out.name= source/sink device name\n" 474#endif 475#ifdef CONFIG_AUDIO_SDL 476 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 477#endif 478#ifdef CONFIG_SPICE 479 "-audiodev spice,id=id[,prop[=value][,...]]\n" 480#endif 481 "-audiodev wav,id=id[,prop[=value][,...]]\n" 482 " path= path of wav file to record\n", 483 QEMU_ARCH_ALL) 484STEXI 485@item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]] 486@findex -audiodev 487Adds a new audio backend @var{driver} identified by @var{id}. There are 488global and driver specific properties. Some values can be set 489differently for input and output, they're marked with @code{in|out.}. 490You can set the input's property with @code{in.@var{prop}} and the 491output's property with @code{out.@var{prop}}. For example: 492@example 493-audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 494-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 495@end example 496 497NOTE: parameter validation is known to be incomplete, in many cases 498specifying an invalid option causes QEMU to print an error message and 499continue emulation without sound. 500 501Valid global options are: 502 503@table @option 504@item id=@var{identifier} 505Identifies the audio backend. 506 507@item timer-period=@var{period} 508Sets the timer @var{period} used by the audio subsystem in microseconds. 509Default is 10000 (10 ms). 510 511@item in|out.mixing-engine=on|off 512Use QEMU's mixing engine to mix all streams inside QEMU and convert 513audio formats when not supported by the backend. When off, 514@var{fixed-settings} must be off too. Note that disabling this option 515means that the selected backend must support multiple streams and the 516audio formats used by the virtual cards, otherwise you'll get no sound. 517It's not recommended to disable this option unless you want to use 5.1 518or 7.1 audio, as mixing engine only supports mono and stereo audio. 519Default is on. 520 521@item in|out.fixed-settings=on|off 522Use fixed settings for host audio. When off, it will change based on 523how the guest opens the sound card. In this case you must not specify 524@var{frequency}, @var{channels} or @var{format}. Default is on. 525 526@item in|out.frequency=@var{frequency} 527Specify the @var{frequency} to use when using @var{fixed-settings}. 528Default is 44100Hz. 529 530@item in|out.channels=@var{channels} 531Specify the number of @var{channels} to use when using 532@var{fixed-settings}. Default is 2 (stereo). 533 534@item in|out.format=@var{format} 535Specify the sample @var{format} to use when using @var{fixed-settings}. 536Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8}, 537@code{u16}, @code{u32}. Default is @code{s16}. 538 539@item in|out.voices=@var{voices} 540Specify the number of @var{voices} to use. Default is 1. 541 542@item in|out.buffer-length=@var{usecs} 543Sets the size of the buffer in microseconds. 544 545@end table 546 547@item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]] 548Creates a dummy backend that discards all outputs. This backend has no 549backend specific properties. 550 551@item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 552Creates backend using the ALSA. This backend is only available on 553Linux. 554 555ALSA specific options are: 556 557@table @option 558 559@item in|out.dev=@var{device} 560Specify the ALSA @var{device} to use for input and/or output. Default 561is @code{default}. 562 563@item in|out.period-length=@var{usecs} 564Sets the period length in microseconds. 565 566@item in|out.try-poll=on|off 567Attempt to use poll mode with the device. Default is on. 568 569@item threshold=@var{threshold} 570Threshold (in microseconds) when playback starts. Default is 0. 571 572@end table 573 574@item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]] 575Creates a backend using Apple's Core Audio. This backend is only 576available on Mac OS and only supports playback. 577 578Core Audio specific options are: 579 580@table @option 581 582@item in|out.buffer-count=@var{count} 583Sets the @var{count} of the buffers. 584 585@end table 586 587@item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]] 588Creates a backend using Microsoft's DirectSound. This backend is only 589available on Windows and only supports playback. 590 591DirectSound specific options are: 592 593@table @option 594 595@item latency=@var{usecs} 596Add extra @var{usecs} microseconds latency to playback. Default is 59710000 (10 ms). 598 599@end table 600 601@item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]] 602Creates a backend using OSS. This backend is available on most 603Unix-like systems. 604 605OSS specific options are: 606 607@table @option 608 609@item in|out.dev=@var{device} 610Specify the file name of the OSS @var{device} to use. Default is 611@code{/dev/dsp}. 612 613@item in|out.buffer-count=@var{count} 614Sets the @var{count} of the buffers. 615 616@item in|out.try-poll=on|of 617Attempt to use poll mode with the device. Default is on. 618 619@item try-mmap=on|off 620Try using memory mapped device access. Default is off. 621 622@item exclusive=on|off 623Open the device in exclusive mode (vmix won't work in this case). 624Default is off. 625 626@item dsp-policy=@var{policy} 627Sets the timing policy (between 0 and 10, where smaller number means 628smaller latency but higher CPU usage). Use -1 to use buffer sizes 629specified by @code{buffer} and @code{buffer-count}. This option is 630ignored if you do not have OSS 4. Default is 5. 631 632@end table 633 634@item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 635Creates a backend using PulseAudio. This backend is available on most 636systems. 637 638PulseAudio specific options are: 639 640@table @option 641 642@item server=@var{server} 643Sets the PulseAudio @var{server} to connect to. 644 645@item in|out.name=@var{sink} 646Use the specified source/sink for recording/playback. 647 648@end table 649 650@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]] 651Creates a backend using SDL. This backend is available on most systems, 652but you should use your platform's native backend if possible. This 653backend has no backend specific properties. 654 655@item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]] 656Creates a backend that sends audio through SPICE. This backend requires 657@code{-spice} and automatically selected in that case, so usually you 658can ignore this option. This backend has no backend specific 659properties. 660 661@item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]] 662Creates a backend that writes audio to a WAV file. 663 664Backend specific options are: 665 666@table @option 667 668@item path=@var{path} 669Write recorded audio into the specified file. Default is 670@code{qemu.wav}. 671 672@end table 673ETEXI 674 675DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 676 "-soundhw c1,... enable audio support\n" 677 " and only specified sound cards (comma separated list)\n" 678 " use '-soundhw help' to get the list of supported cards\n" 679 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 680STEXI 681@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 682@findex -soundhw 683Enable audio and selected sound hardware. Use 'help' to print all 684available sound hardware. For example: 685 686@example 687@value{qemu_system_x86} -soundhw sb16,adlib disk.img 688@value{qemu_system_x86} -soundhw es1370 disk.img 689@value{qemu_system_x86} -soundhw ac97 disk.img 690@value{qemu_system_x86} -soundhw hda disk.img 691@value{qemu_system_x86} -soundhw all disk.img 692@value{qemu_system_x86} -soundhw help 693@end example 694 695Note that Linux's i810_audio OSS kernel (for AC97) module might 696require manually specifying clocking. 697 698@example 699modprobe i810_audio clocking=48000 700@end example 701ETEXI 702 703DEF("device", HAS_ARG, QEMU_OPTION_device, 704 "-device driver[,prop[=value][,...]]\n" 705 " add device (based on driver)\n" 706 " prop=value,... sets driver properties\n" 707 " use '-device help' to print all possible drivers\n" 708 " use '-device driver,help' to print all possible properties\n", 709 QEMU_ARCH_ALL) 710STEXI 711@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 712@findex -device 713Add device @var{driver}. @var{prop}=@var{value} sets driver 714properties. Valid properties depend on the driver. To get help on 715possible drivers and properties, use @code{-device help} and 716@code{-device @var{driver},help}. 717 718Some drivers are: 719@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}] 720 721Add an IPMI BMC. This is a simulation of a hardware management 722interface processor that normally sits on a system. It provides 723a watchdog and the ability to reset and power control the system. 724You need to connect this to an IPMI interface to make it useful 725 726The IPMI slave address to use for the BMC. The default is 0x20. 727This address is the BMC's address on the I2C network of management 728controllers. If you don't know what this means, it is safe to ignore 729it. 730 731@table @option 732@item id=@var{id} 733The BMC id for interfaces to use this device. 734@item slave_addr=@var{val} 735Define slave address to use for the BMC. The default is 0x20. 736@item sdrfile=@var{file} 737file containing raw Sensor Data Records (SDR) data. The default is none. 738@item fruareasize=@var{val} 739size of a Field Replaceable Unit (FRU) area. The default is 1024. 740@item frudatafile=@var{file} 741file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 742@item guid=@var{uuid} 743value for the GUID for the BMC, in standard UUID format. If this is set, 744get "Get GUID" command to the BMC will return it. Otherwise "Get GUID" 745will return an error. 746@end table 747 748@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 749 750Add a connection to an external IPMI BMC simulator. Instead of 751locally emulating the BMC like the above item, instead connect 752to an external entity that provides the IPMI services. 753 754A connection is made to an external BMC simulator. If you do this, it 755is strongly recommended that you use the "reconnect=" chardev option 756to reconnect to the simulator if the connection is lost. Note that if 757this is not used carefully, it can be a security issue, as the 758interface has the ability to send resets, NMIs, and power off the VM. 759It's best if QEMU makes a connection to an external simulator running 760on a secure port on localhost, so neither the simulator nor QEMU is 761exposed to any outside network. 762 763See the "lanserv/README.vm" file in the OpenIPMI library for more 764details on the external interface. 765 766@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 767 768Add a KCS IPMI interafce on the ISA bus. This also adds a 769corresponding ACPI and SMBIOS entries, if appropriate. 770 771@table @option 772@item bmc=@var{id} 773The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 774@item ioport=@var{val} 775Define the I/O address of the interface. The default is 0xca0 for KCS. 776@item irq=@var{val} 777Define the interrupt to use. The default is 5. To disable interrupts, 778set this to 0. 779@end table 780 781@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 782 783Like the KCS interface, but defines a BT interface. The default port is 7840xe4 and the default interrupt is 5. 785 786ETEXI 787 788DEF("name", HAS_ARG, QEMU_OPTION_name, 789 "-name string1[,process=string2][,debug-threads=on|off]\n" 790 " set the name of the guest\n" 791 " string1 sets the window title and string2 the process name\n" 792 " When debug-threads is enabled, individual threads are given a separate name\n" 793 " NOTE: The thread names are for debugging and not a stable API.\n", 794 QEMU_ARCH_ALL) 795STEXI 796@item -name @var{name} 797@findex -name 798Sets the @var{name} of the guest. 799This name will be displayed in the SDL window caption. 800The @var{name} will also be used for the VNC server. 801Also optionally set the top visible process name in Linux. 802Naming of individual threads can also be enabled on Linux to aid debugging. 803ETEXI 804 805DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 806 "-uuid %08x-%04x-%04x-%04x-%012x\n" 807 " specify machine UUID\n", QEMU_ARCH_ALL) 808STEXI 809@item -uuid @var{uuid} 810@findex -uuid 811Set system UUID. 812ETEXI 813 814STEXI 815@end table 816ETEXI 817DEFHEADING() 818 819DEFHEADING(Block device options:) 820STEXI 821@table @option 822ETEXI 823 824DEF("fda", HAS_ARG, QEMU_OPTION_fda, 825 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 826DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 827STEXI 828@item -fda @var{file} 829@itemx -fdb @var{file} 830@findex -fda 831@findex -fdb 832Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 833ETEXI 834 835DEF("hda", HAS_ARG, QEMU_OPTION_hda, 836 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 837DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 838DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 839 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 840DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 841STEXI 842@item -hda @var{file} 843@itemx -hdb @var{file} 844@itemx -hdc @var{file} 845@itemx -hdd @var{file} 846@findex -hda 847@findex -hdb 848@findex -hdc 849@findex -hdd 850Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 851ETEXI 852 853DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 854 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 855 QEMU_ARCH_ALL) 856STEXI 857@item -cdrom @var{file} 858@findex -cdrom 859Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 860@option{-cdrom} at the same time). You can use the host CD-ROM by 861using @file{/dev/cdrom} as filename (@pxref{host_drives}). 862ETEXI 863 864DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 865 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 866 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 867 " [,read-only=on|off][,auto-read-only=on|off]\n" 868 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 869 " [,driver specific parameters...]\n" 870 " configure a block backend\n", QEMU_ARCH_ALL) 871STEXI 872@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 873@findex -blockdev 874 875Define a new block driver node. Some of the options apply to all block drivers, 876other options are only accepted for a specific block driver. See below for a 877list of generic options and options for the most common block drivers. 878 879Options that expect a reference to another node (e.g. @code{file}) can be 880given in two ways. Either you specify the node name of an already existing node 881(file=@var{node-name}), or you define a new node inline, adding options 882for the referenced node after a dot (file.filename=@var{path},file.aio=native). 883 884A block driver node created with @option{-blockdev} can be used for a guest 885device by specifying its node name for the @code{drive} property in a 886@option{-device} argument that defines a block device. 887 888@table @option 889@item Valid options for any block driver node: 890 891@table @code 892@item driver 893Specifies the block driver to use for the given node. 894@item node-name 895This defines the name of the block driver node by which it will be referenced 896later. The name must be unique, i.e. it must not match the name of a different 897block driver node, or (if you use @option{-drive} as well) the ID of a drive. 898 899If no node name is specified, it is automatically generated. The generated node 900name is not intended to be predictable and changes between QEMU invocations. 901For the top level, an explicit node name must be specified. 902@item read-only 903Open the node read-only. Guest write attempts will fail. 904 905Note that some block drivers support only read-only access, either generally or 906in certain configurations. In this case, the default value 907@option{read-only=off} does not work and the option must be specified 908explicitly. 909@item auto-read-only 910If @option{auto-read-only=on} is set, QEMU may fall back to read-only usage 911even when @option{read-only=off} is requested, or even switch between modes as 912needed, e.g. depending on whether the image file is writable or whether a 913writing user is attached to the node. 914@item force-share 915Override the image locking system of QEMU by forcing the node to utilize 916weaker shared access for permissions where it would normally request exclusive 917access. When there is the potential for multiple instances to have the same 918file open (whether this invocation of QEMU is the first or the second 919instance), both instances must permit shared access for the second instance to 920succeed at opening the file. 921 922Enabling @option{force-share=on} requires @option{read-only=on}. 923@item cache.direct 924The host page cache can be avoided with @option{cache.direct=on}. This will 925attempt to do disk IO directly to the guest's memory. QEMU may still perform an 926internal copy of the data. 927@item cache.no-flush 928In case you don't care about data integrity over host failures, you can use 929@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 930any data to the disk but can instead keep things in cache. If anything goes 931wrong, like your host losing power, the disk storage getting disconnected 932accidentally, etc. your image will most probably be rendered unusable. 933@item discard=@var{discard} 934@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 935whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 936ignored or passed to the filesystem. Some machine types may not support 937discard requests. 938@item detect-zeroes=@var{detect-zeroes} 939@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 940conversion of plain zero writes by the OS to driver specific optimized 941zero write commands. You may even choose "unmap" if @var{discard} is set 942to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 943@end table 944 945@item Driver-specific options for @code{file} 946 947This is the protocol-level block driver for accessing regular files. 948 949@table @code 950@item filename 951The path to the image file in the local filesystem 952@item aio 953Specifies the AIO backend (threads/native, default: threads) 954@item locking 955Specifies whether the image file is protected with Linux OFD / POSIX locks. The 956default is to use the Linux Open File Descriptor API if available, otherwise no 957lock is applied. (auto/on/off, default: auto) 958@end table 959Example: 960@example 961-blockdev driver=file,node-name=disk,filename=disk.img 962@end example 963 964@item Driver-specific options for @code{raw} 965 966This is the image format block driver for raw images. It is usually 967stacked on top of a protocol level block driver such as @code{file}. 968 969@table @code 970@item file 971Reference to or definition of the data source block driver node 972(e.g. a @code{file} driver node) 973@end table 974Example 1: 975@example 976-blockdev driver=file,node-name=disk_file,filename=disk.img 977-blockdev driver=raw,node-name=disk,file=disk_file 978@end example 979Example 2: 980@example 981-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 982@end example 983 984@item Driver-specific options for @code{qcow2} 985 986This is the image format block driver for qcow2 images. It is usually 987stacked on top of a protocol level block driver such as @code{file}. 988 989@table @code 990@item file 991Reference to or definition of the data source block driver node 992(e.g. a @code{file} driver node) 993 994@item backing 995Reference to or definition of the backing file block device (default is taken 996from the image file). It is allowed to pass @code{null} here in order to disable 997the default backing file. 998 999@item lazy-refcounts 1000Whether to enable the lazy refcounts feature (on/off; default is taken from the 1001image file) 1002 1003@item cache-size 1004The maximum total size of the L2 table and refcount block caches in bytes 1005(default: the sum of l2-cache-size and refcount-cache-size) 1006 1007@item l2-cache-size 1008The maximum size of the L2 table cache in bytes 1009(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 1010non-Linux platforms; otherwise, as large as possible within the cache-size, 1011while permitting the requested or the minimal refcount cache size) 1012 1013@item refcount-cache-size 1014The maximum size of the refcount block cache in bytes 1015(default: 4 times the cluster size; or if cache-size is specified, the part of 1016it which is not used for the L2 cache) 1017 1018@item cache-clean-interval 1019Clean unused entries in the L2 and refcount caches. The interval is in seconds. 1020The default value is 600 on supporting platforms, and 0 on other platforms. 1021Setting it to 0 disables this feature. 1022 1023@item pass-discard-request 1024Whether discard requests to the qcow2 device should be forwarded to the data 1025source (on/off; default: on if discard=unmap is specified, off otherwise) 1026 1027@item pass-discard-snapshot 1028Whether discard requests for the data source should be issued when a snapshot 1029operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 1030default: on) 1031 1032@item pass-discard-other 1033Whether discard requests for the data source should be issued on other 1034occasions where a cluster gets freed (on/off; default: off) 1035 1036@item overlap-check 1037Which overlap checks to perform for writes to the image 1038(none/constant/cached/all; default: cached). For details or finer 1039granularity control refer to the QAPI documentation of @code{blockdev-add}. 1040@end table 1041 1042Example 1: 1043@example 1044-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1045-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1046@end example 1047Example 2: 1048@example 1049-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1050@end example 1051 1052@item Driver-specific options for other drivers 1053Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1054 1055@end table 1056 1057ETEXI 1058 1059DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1060 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1061 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1062 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1063 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1064 " [,readonly=on|off][,copy-on-read=on|off]\n" 1065 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1066 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1067 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1068 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1069 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1070 " [[,iops_size=is]]\n" 1071 " [[,group=g]]\n" 1072 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1073STEXI 1074@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1075@findex -drive 1076 1077Define a new drive. This includes creating a block driver node (the backend) as 1078well as a guest device, and is mostly a shortcut for defining the corresponding 1079@option{-blockdev} and @option{-device} options. 1080 1081@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1082addition, it knows the following options: 1083 1084@table @option 1085@item file=@var{file} 1086This option defines which disk image (@pxref{disk_images}) to use with 1087this drive. If the filename contains comma, you must double it 1088(for instance, "file=my,,file" to use file "my,file"). 1089 1090Special files such as iSCSI devices can be specified using protocol 1091specific URLs. See the section for "Device URL Syntax" for more information. 1092@item if=@var{interface} 1093This option defines on which type on interface the drive is connected. 1094Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1095@item bus=@var{bus},unit=@var{unit} 1096These options define where is connected the drive by defining the bus number and 1097the unit id. 1098@item index=@var{index} 1099This option defines where is connected the drive by using an index in the list 1100of available connectors of a given interface type. 1101@item media=@var{media} 1102This option defines the type of the media: disk or cdrom. 1103@item snapshot=@var{snapshot} 1104@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1105(see @option{-snapshot}). 1106@item cache=@var{cache} 1107@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1108and controls how the host cache is used to access block data. This is a 1109shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1110options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1111which provides a default for the @option{write-cache} option of block guest 1112devices (as in @option{-device}). The modes correspond to the following 1113settings: 1114 1115@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1116@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1117@c and the HTML output. 1118@example 1119@ │ cache.writeback cache.direct cache.no-flush 1120─────────────┼───────────────────────────────────────────────── 1121writeback │ on off off 1122none │ on on off 1123writethrough │ off off off 1124directsync │ off on off 1125unsafe │ on off on 1126@end example 1127 1128The default mode is @option{cache=writeback}. 1129 1130@item aio=@var{aio} 1131@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1132@item format=@var{format} 1133Specify which disk @var{format} will be used rather than detecting 1134the format. Can be used to specify format=raw to avoid interpreting 1135an untrusted format header. 1136@item werror=@var{action},rerror=@var{action} 1137Specify which @var{action} to take on write and read errors. Valid actions are: 1138"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1139"report" (report the error to the guest), "enospc" (pause QEMU only if the 1140host disk is full; report the error to the guest otherwise). 1141The default setting is @option{werror=enospc} and @option{rerror=report}. 1142@item copy-on-read=@var{copy-on-read} 1143@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1144file sectors into the image file. 1145@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1146Specify bandwidth throttling limits in bytes per second, either for all request 1147types or for reads or writes only. Small values can lead to timeouts or hangs 1148inside the guest. A safe minimum for disks is 2 MB/s. 1149@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1150Specify bursts in bytes per second, either for all request types or for reads 1151or writes only. Bursts allow the guest I/O to spike above the limit 1152temporarily. 1153@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1154Specify request rate limits in requests per second, either for all request 1155types or for reads or writes only. 1156@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1157Specify bursts in requests per second, either for all request types or for reads 1158or writes only. Bursts allow the guest I/O to spike above the limit 1159temporarily. 1160@item iops_size=@var{is} 1161Let every @var{is} bytes of a request count as a new request for iops 1162throttling purposes. Use this option to prevent guests from circumventing iops 1163limits by sending fewer but larger requests. 1164@item group=@var{g} 1165Join a throttling quota group with given name @var{g}. All drives that are 1166members of the same group are accounted for together. Use this option to 1167prevent guests from circumventing throttling limits by using many small disks 1168instead of a single larger disk. 1169@end table 1170 1171By default, the @option{cache.writeback=on} mode is used. It will report data 1172writes as completed as soon as the data is present in the host page cache. 1173This is safe as long as your guest OS makes sure to correctly flush disk caches 1174where needed. If your guest OS does not handle volatile disk write caches 1175correctly and your host crashes or loses power, then the guest may experience 1176data corruption. 1177 1178For such guests, you should consider using @option{cache.writeback=off}. This 1179means that the host page cache will be used to read and write data, but write 1180notification will be sent to the guest only after QEMU has made sure to flush 1181each write to the disk. Be aware that this has a major impact on performance. 1182 1183When using the @option{-snapshot} option, unsafe caching is always used. 1184 1185Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1186useful when the backing file is over a slow network. By default copy-on-read 1187is off. 1188 1189Instead of @option{-cdrom} you can use: 1190@example 1191@value{qemu_system} -drive file=file,index=2,media=cdrom 1192@end example 1193 1194Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1195use: 1196@example 1197@value{qemu_system} -drive file=file,index=0,media=disk 1198@value{qemu_system} -drive file=file,index=1,media=disk 1199@value{qemu_system} -drive file=file,index=2,media=disk 1200@value{qemu_system} -drive file=file,index=3,media=disk 1201@end example 1202 1203You can open an image using pre-opened file descriptors from an fd set: 1204@example 1205@value{qemu_system} \ 1206 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 1207 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 1208 -drive file=/dev/fdset/2,index=0,media=disk 1209@end example 1210 1211You can connect a CDROM to the slave of ide0: 1212@example 1213@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom 1214@end example 1215 1216If you don't specify the "file=" argument, you define an empty drive: 1217@example 1218@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom 1219@end example 1220 1221Instead of @option{-fda}, @option{-fdb}, you can use: 1222@example 1223@value{qemu_system_x86} -drive file=file,index=0,if=floppy 1224@value{qemu_system_x86} -drive file=file,index=1,if=floppy 1225@end example 1226 1227By default, @var{interface} is "ide" and @var{index} is automatically 1228incremented: 1229@example 1230@value{qemu_system_x86} -drive file=a -drive file=b" 1231@end example 1232is interpreted like: 1233@example 1234@value{qemu_system_x86} -hda a -hdb b 1235@end example 1236ETEXI 1237 1238DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1239 "-mtdblock file use 'file' as on-board Flash memory image\n", 1240 QEMU_ARCH_ALL) 1241STEXI 1242@item -mtdblock @var{file} 1243@findex -mtdblock 1244Use @var{file} as on-board Flash memory image. 1245ETEXI 1246 1247DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1248 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1249STEXI 1250@item -sd @var{file} 1251@findex -sd 1252Use @var{file} as SecureDigital card image. 1253ETEXI 1254 1255DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1256 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1257STEXI 1258@item -pflash @var{file} 1259@findex -pflash 1260Use @var{file} as a parallel flash image. 1261ETEXI 1262 1263DEF("snapshot", 0, QEMU_OPTION_snapshot, 1264 "-snapshot write to temporary files instead of disk image files\n", 1265 QEMU_ARCH_ALL) 1266STEXI 1267@item -snapshot 1268@findex -snapshot 1269Write to temporary files instead of disk image files. In this case, 1270the raw disk image you use is not written back. You can however force 1271the write back by pressing @key{C-a s} (@pxref{disk_images}). 1272ETEXI 1273 1274DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1275 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1276 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1277 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1278 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1279 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1280 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1281 " [[,throttling.iops-size=is]]\n" 1282 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1283 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1284 "-fsdev synth,id=id\n", 1285 QEMU_ARCH_ALL) 1286 1287STEXI 1288 1289@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}[,...]]] 1290@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1291@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1292@itemx -fsdev synth,id=@var{id}[,readonly] 1293@findex -fsdev 1294Define a new file system device. Valid options are: 1295@table @option 1296@item local 1297Accesses to the filesystem are done by QEMU. 1298@item proxy 1299Accesses to the filesystem are done by virtfs-proxy-helper(1). 1300@item synth 1301Synthetic filesystem, only used by QTests. 1302@item id=@var{id} 1303Specifies identifier for this device. 1304@item path=@var{path} 1305Specifies the export path for the file system device. Files under 1306this path will be available to the 9p client on the guest. 1307@item security_model=@var{security_model} 1308Specifies the security model to be used for this export path. 1309Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1310In "passthrough" security model, files are stored using the same 1311credentials as they are created on the guest. This requires QEMU 1312to run as root. In "mapped-xattr" security model, some of the file 1313attributes like uid, gid, mode bits and link target are stored as 1314file attributes. For "mapped-file" these attributes are stored in the 1315hidden .virtfs_metadata directory. Directories exported by this security model cannot 1316interact with other unix tools. "none" security model is same as 1317passthrough except the sever won't report failures if it fails to 1318set file attributes like ownership. Security model is mandatory 1319only for local fsdriver. Other fsdrivers (like proxy) don't take 1320security model as a parameter. 1321@item writeout=@var{writeout} 1322This is an optional argument. The only supported value is "immediate". 1323This means that host page cache will be used to read and write data but 1324write notification will be sent to the guest only when the data has been 1325reported as written by the storage subsystem. 1326@item readonly 1327Enables exporting 9p share as a readonly mount for guests. By default 1328read-write access is given. 1329@item socket=@var{socket} 1330Enables proxy filesystem driver to use passed socket file for communicating 1331with virtfs-proxy-helper(1). 1332@item sock_fd=@var{sock_fd} 1333Enables proxy filesystem driver to use passed socket descriptor for 1334communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1335will create socketpair and pass one of the fds as sock_fd. 1336@item fmode=@var{fmode} 1337Specifies the default mode for newly created files on the host. Works only 1338with security models "mapped-xattr" and "mapped-file". 1339@item dmode=@var{dmode} 1340Specifies the default mode for newly created directories on the host. Works 1341only with security models "mapped-xattr" and "mapped-file". 1342@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1343Specify bandwidth throttling limits in bytes per second, either for all request 1344types or for reads or writes only. 1345@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1346Specify bursts in bytes per second, either for all request types or for reads 1347or writes only. Bursts allow the guest I/O to spike above the limit 1348temporarily. 1349@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1350Specify request rate limits in requests per second, either for all request 1351types or for reads or writes only. 1352@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1353Specify bursts in requests per second, either for all request types or for reads 1354or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1355@item throttling.iops-size=@var{is} 1356Let every @var{is} bytes of a request count as a new request for iops 1357throttling purposes. 1358@end table 1359 1360-fsdev option is used along with -device driver "virtio-9p-...". 1361@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1362Options for virtio-9p-... driver are: 1363@table @option 1364@item @var{type} 1365Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1366depending on the machine type. 1367@item fsdev=@var{id} 1368Specifies the id value specified along with -fsdev option. 1369@item mount_tag=@var{mount_tag} 1370Specifies the tag name to be used by the guest to mount this export point. 1371@end table 1372 1373ETEXI 1374 1375DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1376 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1377 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1378 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1379 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1380 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1381 QEMU_ARCH_ALL) 1382 1383STEXI 1384 1385@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}][,multidevs=@var{multidevs}] 1386@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1387@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1388@itemx -virtfs synth,mount_tag=@var{mount_tag} 1389@findex -virtfs 1390 1391Define 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: 1392@table @option 1393@item local 1394Accesses to the filesystem are done by QEMU. 1395@item proxy 1396Accesses to the filesystem are done by virtfs-proxy-helper(1). 1397@item synth 1398Synthetic filesystem, only used by QTests. 1399@item id=@var{id} 1400Specifies identifier for the filesystem device 1401@item path=@var{path} 1402Specifies the export path for the file system device. Files under 1403this path will be available to the 9p client on the guest. 1404@item security_model=@var{security_model} 1405Specifies the security model to be used for this export path. 1406Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1407In "passthrough" security model, files are stored using the same 1408credentials as they are created on the guest. This requires QEMU 1409to run as root. In "mapped-xattr" security model, some of the file 1410attributes like uid, gid, mode bits and link target are stored as 1411file attributes. For "mapped-file" these attributes are stored in the 1412hidden .virtfs_metadata directory. Directories exported by this security model cannot 1413interact with other unix tools. "none" security model is same as 1414passthrough except the sever won't report failures if it fails to 1415set file attributes like ownership. Security model is mandatory only 1416for local fsdriver. Other fsdrivers (like proxy) don't take security 1417model as a parameter. 1418@item writeout=@var{writeout} 1419This is an optional argument. The only supported value is "immediate". 1420This means that host page cache will be used to read and write data but 1421write notification will be sent to the guest only when the data has been 1422reported as written by the storage subsystem. 1423@item readonly 1424Enables exporting 9p share as a readonly mount for guests. By default 1425read-write access is given. 1426@item socket=@var{socket} 1427Enables proxy filesystem driver to use passed socket file for 1428communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1429will create socketpair and pass one of the fds as sock_fd. 1430@item sock_fd 1431Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1432descriptor for interfacing with virtfs-proxy-helper(1). 1433@item fmode=@var{fmode} 1434Specifies the default mode for newly created files on the host. Works only 1435with security models "mapped-xattr" and "mapped-file". 1436@item dmode=@var{dmode} 1437Specifies the default mode for newly created directories on the host. Works 1438only with security models "mapped-xattr" and "mapped-file". 1439@item mount_tag=@var{mount_tag} 1440Specifies the tag name to be used by the guest to mount this export point. 1441@item multidevs=@var{multidevs} 1442Specifies how to deal with multiple devices being shared with a 9p export. 1443Supported behaviours are either "remap", "forbid" or "warn". The latter is 1444the default behaviour on which virtfs 9p expects only one device to be 1445shared with the same export, and if more than one device is shared and 1446accessed via the same 9p export then only a warning message is logged 1447(once) by qemu on host side. In order to avoid file ID collisions on guest 1448you should either create a separate virtfs export for each device to be 1449shared with guests (recommended way) or you might use "remap" instead which 1450allows you to share multiple devices with only one export instead, which is 1451achieved by remapping the original inode numbers from host to guest in a 1452way that would prevent such collisions. Remapping inodes in such use cases 1453is required because the original device IDs from host are never passed and 1454exposed on guest. Instead all files of an export shared with virtfs always 1455share the same device id on guest. So two files with identical inode 1456numbers but from actually different devices on host would otherwise cause a 1457file ID collision and hence potential misbehaviours on guest. "forbid" on 1458the other hand assumes like "warn" that only one device is shared by the 1459same export, however it will not only log a warning message but also 1460deny access to additional devices on guest. Note though that "forbid" does 1461currently not block all possible file access operations (e.g. readdir() 1462would still return entries from other devices). 1463@end table 1464ETEXI 1465 1466DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1467 "-virtfs_synth Create synthetic file system image\n", 1468 QEMU_ARCH_ALL) 1469STEXI 1470@item -virtfs_synth 1471@findex -virtfs_synth 1472Create synthetic file system image. Note that this option is now deprecated. 1473Please use @code{-fsdev synth} and @code{-device virtio-9p-...} instead. 1474ETEXI 1475 1476DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1477 "-iscsi [user=user][,password=password]\n" 1478 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1479 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1480 " [,timeout=timeout]\n" 1481 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1482 1483STEXI 1484@item -iscsi 1485@findex -iscsi 1486Configure iSCSI session parameters. 1487ETEXI 1488 1489STEXI 1490@end table 1491ETEXI 1492DEFHEADING() 1493 1494DEFHEADING(USB options:) 1495STEXI 1496@table @option 1497ETEXI 1498 1499DEF("usb", 0, QEMU_OPTION_usb, 1500 "-usb enable on-board USB host controller (if not enabled by default)\n", 1501 QEMU_ARCH_ALL) 1502STEXI 1503@item -usb 1504@findex -usb 1505Enable USB emulation on machine types with an on-board USB host controller (if 1506not enabled by default). Note that on-board USB host controllers may not 1507support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1508on machines with PCI. 1509ETEXI 1510 1511DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1512 "-usbdevice name add the host or guest USB device 'name'\n", 1513 QEMU_ARCH_ALL) 1514STEXI 1515 1516@item -usbdevice @var{devname} 1517@findex -usbdevice 1518Add the USB device @var{devname}. Note that this option is deprecated, 1519please use @code{-device usb-...} instead. @xref{usb_devices}. 1520 1521@table @option 1522 1523@item mouse 1524Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1525 1526@item tablet 1527Pointer device that uses absolute coordinates (like a touchscreen). This 1528means QEMU is able to report the mouse position without having to grab the 1529mouse. Also overrides the PS/2 mouse emulation when activated. 1530 1531@item braille 1532Braille device. This will use BrlAPI to display the braille output on a real 1533or fake device. 1534 1535@end table 1536ETEXI 1537 1538STEXI 1539@end table 1540ETEXI 1541DEFHEADING() 1542 1543DEFHEADING(Display options:) 1544STEXI 1545@table @option 1546ETEXI 1547 1548DEF("display", HAS_ARG, QEMU_OPTION_display, 1549 "-display spice-app[,gl=on|off]\n" 1550 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1551 " [,window_close=on|off][,gl=on|core|es|off]\n" 1552 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1553 "-display vnc=<display>[,<optargs>]\n" 1554 "-display curses[,charset=<encoding>]\n" 1555 "-display none\n" 1556 "-display egl-headless[,rendernode=<file>]" 1557 " select display type\n" 1558 "The default display is equivalent to\n" 1559#if defined(CONFIG_GTK) 1560 "\t\"-display gtk\"\n" 1561#elif defined(CONFIG_SDL) 1562 "\t\"-display sdl\"\n" 1563#elif defined(CONFIG_COCOA) 1564 "\t\"-display cocoa\"\n" 1565#elif defined(CONFIG_VNC) 1566 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1567#else 1568 "\t\"-display none\"\n" 1569#endif 1570 , QEMU_ARCH_ALL) 1571STEXI 1572@item -display @var{type} 1573@findex -display 1574Select type of display to use. This option is a replacement for the 1575old style -sdl/-curses/... options. Valid values for @var{type} are 1576@table @option 1577@item sdl 1578Display video output via SDL (usually in a separate graphics 1579window; see the SDL documentation for other possibilities). 1580@item curses 1581Display video output via curses. For graphics device models which 1582support a text mode, QEMU can display this output using a 1583curses/ncurses interface. Nothing is displayed when the graphics 1584device is in graphical mode or if the graphics device does not support 1585a text mode. Generally only the VGA device models support text mode. 1586The font charset used by the guest can be specified with the 1587@code{charset} option, for example @code{charset=CP850} for IBM CP850 1588encoding. The default is @code{CP437}. 1589@item none 1590Do not display video output. The guest will still see an emulated 1591graphics card, but its output will not be displayed to the QEMU 1592user. This option differs from the -nographic option in that it 1593only affects what is done with video output; -nographic also changes 1594the destination of the serial and parallel port data. 1595@item gtk 1596Display video output in a GTK window. This interface provides drop-down 1597menus and other UI elements to configure and control the VM during 1598runtime. 1599@item vnc 1600Start a VNC server on display <arg> 1601@item egl-headless 1602Offload all OpenGL operations to a local DRI device. For any graphical display, 1603this display needs to be paired with either VNC or SPICE displays. 1604@item spice-app 1605Start QEMU as a Spice server and launch the default Spice client 1606application. The Spice server will redirect the serial consoles and 1607QEMU monitors. (Since 4.0) 1608@end table 1609ETEXI 1610 1611DEF("nographic", 0, QEMU_OPTION_nographic, 1612 "-nographic disable graphical output and redirect serial I/Os to console\n", 1613 QEMU_ARCH_ALL) 1614STEXI 1615@item -nographic 1616@findex -nographic 1617Normally, if QEMU is compiled with graphical window support, it displays 1618output such as guest graphics, guest console, and the QEMU monitor in a 1619window. With this option, you can totally disable graphical output so 1620that QEMU is a simple command line application. The emulated serial port 1621is redirected on the console and muxed with the monitor (unless 1622redirected elsewhere explicitly). Therefore, you can still use QEMU to 1623debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1624switching between the console and monitor. 1625ETEXI 1626 1627DEF("curses", 0, QEMU_OPTION_curses, 1628 "-curses shorthand for -display curses\n", 1629 QEMU_ARCH_ALL) 1630STEXI 1631@item -curses 1632@findex -curses 1633Normally, if QEMU is compiled with graphical window support, it displays 1634output such as guest graphics, guest console, and the QEMU monitor in a 1635window. With this option, QEMU can display the VGA output when in text 1636mode using a curses/ncurses interface. Nothing is displayed in graphical 1637mode. 1638ETEXI 1639 1640DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1641 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1642 QEMU_ARCH_ALL) 1643STEXI 1644@item -alt-grab 1645@findex -alt-grab 1646Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1647affects the special keys (for fullscreen, monitor-mode switching, etc). 1648ETEXI 1649 1650DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1651 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1652 QEMU_ARCH_ALL) 1653STEXI 1654@item -ctrl-grab 1655@findex -ctrl-grab 1656Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1657affects the special keys (for fullscreen, monitor-mode switching, etc). 1658ETEXI 1659 1660DEF("no-quit", 0, QEMU_OPTION_no_quit, 1661 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1662STEXI 1663@item -no-quit 1664@findex -no-quit 1665Disable SDL window close capability. 1666ETEXI 1667 1668DEF("sdl", 0, QEMU_OPTION_sdl, 1669 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1670STEXI 1671@item -sdl 1672@findex -sdl 1673Enable SDL. 1674ETEXI 1675 1676DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1677 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1678 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1679 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1680 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1681 " [,tls-ciphers=<list>]\n" 1682 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1683 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1684 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1685 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1686 " [,jpeg-wan-compression=[auto|never|always]]\n" 1687 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1688 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1689 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1690 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1691 " [,gl=[on|off]][,rendernode=<file>]\n" 1692 " enable spice\n" 1693 " at least one of {port, tls-port} is mandatory\n", 1694 QEMU_ARCH_ALL) 1695STEXI 1696@item -spice @var{option}[,@var{option}[,...]] 1697@findex -spice 1698Enable the spice remote desktop protocol. Valid options are 1699 1700@table @option 1701 1702@item port=<nr> 1703Set the TCP port spice is listening on for plaintext channels. 1704 1705@item addr=<addr> 1706Set the IP address spice is listening on. Default is any address. 1707 1708@item ipv4 1709@itemx ipv6 1710@itemx unix 1711Force using the specified IP version. 1712 1713@item password=<secret> 1714Set the password you need to authenticate. 1715 1716@item sasl 1717Require that the client use SASL to authenticate with the spice. 1718The exact choice of authentication method used is controlled from the 1719system / user's SASL configuration file for the 'qemu' service. This 1720is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1721unprivileged user, an environment variable SASL_CONF_PATH can be used 1722to make it search alternate locations for the service config. 1723While some SASL auth methods can also provide data encryption (eg GSSAPI), 1724it is recommended that SASL always be combined with the 'tls' and 1725'x509' settings to enable use of SSL and server certificates. This 1726ensures a data encryption preventing compromise of authentication 1727credentials. 1728 1729@item disable-ticketing 1730Allow client connects without authentication. 1731 1732@item disable-copy-paste 1733Disable copy paste between the client and the guest. 1734 1735@item disable-agent-file-xfer 1736Disable spice-vdagent based file-xfer between the client and the guest. 1737 1738@item tls-port=<nr> 1739Set the TCP port spice is listening on for encrypted channels. 1740 1741@item x509-dir=<dir> 1742Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1743 1744@item x509-key-file=<file> 1745@itemx x509-key-password=<file> 1746@itemx x509-cert-file=<file> 1747@itemx x509-cacert-file=<file> 1748@itemx x509-dh-key-file=<file> 1749The x509 file names can also be configured individually. 1750 1751@item tls-ciphers=<list> 1752Specify which ciphers to use. 1753 1754@item tls-channel=[main|display|cursor|inputs|record|playback] 1755@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1756Force specific channel to be used with or without TLS encryption. The 1757options can be specified multiple times to configure multiple 1758channels. The special name "default" can be used to set the default 1759mode. For channels which are not explicitly forced into one mode the 1760spice client is allowed to pick tls/plaintext as he pleases. 1761 1762@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1763Configure image compression (lossless). 1764Default is auto_glz. 1765 1766@item jpeg-wan-compression=[auto|never|always] 1767@itemx zlib-glz-wan-compression=[auto|never|always] 1768Configure wan image compression (lossy for slow links). 1769Default is auto. 1770 1771@item streaming-video=[off|all|filter] 1772Configure video stream detection. Default is off. 1773 1774@item agent-mouse=[on|off] 1775Enable/disable passing mouse events via vdagent. Default is on. 1776 1777@item playback-compression=[on|off] 1778Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1779 1780@item seamless-migration=[on|off] 1781Enable/disable spice seamless migration. Default is off. 1782 1783@item gl=[on|off] 1784Enable/disable OpenGL context. Default is off. 1785 1786@item rendernode=<file> 1787DRM render node for OpenGL rendering. If not specified, it will pick 1788the first available. (Since 2.9) 1789 1790@end table 1791ETEXI 1792 1793DEF("portrait", 0, QEMU_OPTION_portrait, 1794 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1795 QEMU_ARCH_ALL) 1796STEXI 1797@item -portrait 1798@findex -portrait 1799Rotate graphical output 90 deg left (only PXA LCD). 1800ETEXI 1801 1802DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1803 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1804 QEMU_ARCH_ALL) 1805STEXI 1806@item -rotate @var{deg} 1807@findex -rotate 1808Rotate graphical output some deg left (only PXA LCD). 1809ETEXI 1810 1811DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1812 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1813 " select video card type\n", QEMU_ARCH_ALL) 1814STEXI 1815@item -vga @var{type} 1816@findex -vga 1817Select type of VGA card to emulate. Valid values for @var{type} are 1818@table @option 1819@item cirrus 1820Cirrus Logic GD5446 Video card. All Windows versions starting from 1821Windows 95 should recognize and use this graphic card. For optimal 1822performances, use 16 bit color depth in the guest and the host OS. 1823(This card was the default before QEMU 2.2) 1824@item std 1825Standard VGA card with Bochs VBE extensions. If your guest OS 1826supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1827to use high resolution modes (>= 1280x1024x16) then you should use 1828this option. (This card is the default since QEMU 2.2) 1829@item vmware 1830VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1831recent XFree86/XOrg server or Windows guest with a driver for this 1832card. 1833@item qxl 1834QXL paravirtual graphic card. It is VGA compatible (including VESA 18352.0 VBE support). Works best with qxl guest drivers installed though. 1836Recommended choice when using the spice protocol. 1837@item tcx 1838(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1839sun4m machines and offers both 8-bit and 24-bit colour depths at a 1840fixed resolution of 1024x768. 1841@item cg3 1842(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1843for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1844resolutions aimed at people wishing to run older Solaris versions. 1845@item virtio 1846Virtio VGA card. 1847@item none 1848Disable VGA card. 1849@end table 1850ETEXI 1851 1852DEF("full-screen", 0, QEMU_OPTION_full_screen, 1853 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1854STEXI 1855@item -full-screen 1856@findex -full-screen 1857Start in full screen. 1858ETEXI 1859 1860DEF("g", 1, QEMU_OPTION_g , 1861 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1862 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 1863STEXI 1864@item -g @var{width}x@var{height}[x@var{depth}] 1865@findex -g 1866Set the initial graphical resolution and depth (PPC, SPARC only). 1867ETEXI 1868 1869DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1870 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1871STEXI 1872@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1873@findex -vnc 1874Normally, if QEMU is compiled with graphical window support, it displays 1875output such as guest graphics, guest console, and the QEMU monitor in a 1876window. With this option, you can have QEMU listen on VNC display 1877@var{display} and redirect the VGA display over the VNC session. It is 1878very useful to enable the usb tablet device when using this option 1879(option @option{-device usb-tablet}). When using the VNC display, you 1880must use the @option{-k} parameter to set the keyboard layout if you are 1881not using en-us. Valid syntax for the @var{display} is 1882 1883@table @option 1884 1885@item to=@var{L} 1886 1887With this option, QEMU will try next available VNC @var{display}s, until the 1888number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1889available, e.g. port 5900+@var{display} is already used by another 1890application. By default, to=0. 1891 1892@item @var{host}:@var{d} 1893 1894TCP connections will only be allowed from @var{host} on display @var{d}. 1895By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1896be omitted in which case the server will accept connections from any host. 1897 1898@item unix:@var{path} 1899 1900Connections will be allowed over UNIX domain sockets where @var{path} is the 1901location of a unix socket to listen for connections on. 1902 1903@item none 1904 1905VNC is initialized but not started. The monitor @code{change} command 1906can be used to later start the VNC server. 1907 1908@end table 1909 1910Following the @var{display} value there may be one or more @var{option} flags 1911separated by commas. Valid options are 1912 1913@table @option 1914 1915@item reverse 1916 1917Connect to a listening VNC client via a ``reverse'' connection. The 1918client is specified by the @var{display}. For reverse network 1919connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1920is a TCP port number, not a display number. 1921 1922@item websocket 1923 1924Opens an additional TCP listening port dedicated to VNC Websocket connections. 1925If a bare @var{websocket} option is given, the Websocket port is 19265700+@var{display}. An alternative port can be specified with the 1927syntax @code{websocket}=@var{port}. 1928 1929If @var{host} is specified connections will only be allowed from this host. 1930It is possible to control the websocket listen address independently, using 1931the syntax @code{websocket}=@var{host}:@var{port}. 1932 1933If no TLS credentials are provided, the websocket connection runs in 1934unencrypted mode. If TLS credentials are provided, the websocket connection 1935requires encrypted client connections. 1936 1937@item password 1938 1939Require that password based authentication is used for client connections. 1940 1941The password must be set separately using the @code{set_password} command in 1942the @ref{pcsys_monitor}. The syntax to change your password is: 1943@code{set_password <protocol> <password>} where <protocol> could be either 1944"vnc" or "spice". 1945 1946If you would like to change <protocol> password expiration, you should use 1947@code{expire_password <protocol> <expiration-time>} where expiration time could 1948be one of the following options: now, never, +seconds or UNIX time of 1949expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1950to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1951date and time). 1952 1953You can also use keywords "now" or "never" for the expiration time to 1954allow <protocol> password to expire immediately or never expire. 1955 1956@item tls-creds=@var{ID} 1957 1958Provides the ID of a set of TLS credentials to use to secure the 1959VNC server. They will apply to both the normal VNC server socket 1960and the websocket socket (if enabled). Setting TLS credentials 1961will cause the VNC server socket to enable the VeNCrypt auth 1962mechanism. The credentials should have been previously created 1963using the @option{-object tls-creds} argument. 1964 1965@item tls-authz=@var{ID} 1966 1967Provides the ID of the QAuthZ authorization object against which 1968the client's x509 distinguished name will validated. This object is 1969only resolved at time of use, so can be deleted and recreated on the 1970fly while the VNC server is active. If missing, it will default 1971to denying access. 1972 1973@item sasl 1974 1975Require that the client use SASL to authenticate with the VNC server. 1976The exact choice of authentication method used is controlled from the 1977system / user's SASL configuration file for the 'qemu' service. This 1978is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1979unprivileged user, an environment variable SASL_CONF_PATH can be used 1980to make it search alternate locations for the service config. 1981While some SASL auth methods can also provide data encryption (eg GSSAPI), 1982it is recommended that SASL always be combined with the 'tls' and 1983'x509' settings to enable use of SSL and server certificates. This 1984ensures a data encryption preventing compromise of authentication 1985credentials. See the @ref{vnc_security} section for details on using 1986SASL authentication. 1987 1988@item sasl-authz=@var{ID} 1989 1990Provides the ID of the QAuthZ authorization object against which 1991the client's SASL username will validated. This object is 1992only resolved at time of use, so can be deleted and recreated on the 1993fly while the VNC server is active. If missing, it will default 1994to denying access. 1995 1996@item acl 1997 1998Legacy method for enabling authorization of clients against the 1999x509 distinguished name and SASL username. It results in the creation 2000of two @code{authz-list} objects with IDs of @code{vnc.username} and 2001@code{vnc.x509dname}. The rules for these objects must be configured 2002with the HMP ACL commands. 2003 2004This option is deprecated and should no longer be used. The new 2005@option{sasl-authz} and @option{tls-authz} options are a 2006replacement. 2007 2008@item lossy 2009 2010Enable lossy compression methods (gradient, JPEG, ...). If this 2011option is set, VNC client may receive lossy framebuffer updates 2012depending on its encoding settings. Enabling this option can save 2013a lot of bandwidth at the expense of quality. 2014 2015@item non-adaptive 2016 2017Disable adaptive encodings. Adaptive encodings are enabled by default. 2018An adaptive encoding will try to detect frequently updated screen regions, 2019and send updates in these regions using a lossy encoding (like JPEG). 2020This can be really helpful to save bandwidth when playing videos. Disabling 2021adaptive encodings restores the original static behavior of encodings 2022like Tight. 2023 2024@item share=[allow-exclusive|force-shared|ignore] 2025 2026Set display sharing policy. 'allow-exclusive' allows clients to ask 2027for exclusive access. As suggested by the rfb spec this is 2028implemented by dropping other connections. Connecting multiple 2029clients in parallel requires all clients asking for a shared session 2030(vncviewer: -shared switch). This is the default. 'force-shared' 2031disables exclusive client access. Useful for shared desktop sessions, 2032where you don't want someone forgetting specify -shared disconnect 2033everybody else. 'ignore' completely ignores the shared flag and 2034allows everybody connect unconditionally. Doesn't conform to the rfb 2035spec but is traditional QEMU behavior. 2036 2037@item key-delay-ms 2038 2039Set keyboard delay, for key down and key up events, in milliseconds. 2040Default is 10. Keyboards are low-bandwidth devices, so this slowdown 2041can help the device and guest to keep up and not lose events in case 2042events are arriving in bulk. Possible causes for the latter are flaky 2043network connections, or scripts for automated testing. 2044 2045@item audiodev=@var{audiodev} 2046 2047Use the specified @var{audiodev} when the VNC client requests audio 2048transmission. When not using an -audiodev argument, this option must 2049be omitted, otherwise is must be present and specify a valid audiodev. 2050 2051@end table 2052ETEXI 2053 2054STEXI 2055@end table 2056ETEXI 2057ARCHHEADING(, QEMU_ARCH_I386) 2058 2059ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2060STEXI 2061@table @option 2062ETEXI 2063 2064DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2065 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2066 QEMU_ARCH_I386) 2067STEXI 2068@item -win2k-hack 2069@findex -win2k-hack 2070Use it when installing Windows 2000 to avoid a disk full bug. After 2071Windows 2000 is installed, you no longer need this option (this option 2072slows down the IDE transfers). 2073ETEXI 2074 2075DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2076 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2077 QEMU_ARCH_I386) 2078STEXI 2079@item -no-fd-bootchk 2080@findex -no-fd-bootchk 2081Disable boot signature checking for floppy disks in BIOS. May 2082be needed to boot from old floppy disks. 2083ETEXI 2084 2085DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2086 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2087STEXI 2088@item -no-acpi 2089@findex -no-acpi 2090Disable ACPI (Advanced Configuration and Power Interface) support. Use 2091it if your guest OS complains about ACPI problems (PC target machine 2092only). 2093ETEXI 2094 2095DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2096 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2097STEXI 2098@item -no-hpet 2099@findex -no-hpet 2100Disable HPET support. 2101ETEXI 2102 2103DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2104 "-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" 2105 " ACPI table description\n", QEMU_ARCH_I386) 2106STEXI 2107@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}]...] 2108@findex -acpitable 2109Add ACPI table with specified header fields and context from specified files. 2110For file=, take whole ACPI table from the specified files, including all 2111ACPI headers (possible overridden by other options). 2112For data=, only data 2113portion of the table is used, all header information is specified in the 2114command line. 2115If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2116fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2117to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2118spec. 2119ETEXI 2120 2121DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2122 "-smbios file=binary\n" 2123 " load SMBIOS entry from binary file\n" 2124 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2125 " [,uefi=on|off]\n" 2126 " specify SMBIOS type 0 fields\n" 2127 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2128 " [,uuid=uuid][,sku=str][,family=str]\n" 2129 " specify SMBIOS type 1 fields\n" 2130 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2131 " [,asset=str][,location=str]\n" 2132 " specify SMBIOS type 2 fields\n" 2133 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2134 " [,sku=str]\n" 2135 " specify SMBIOS type 3 fields\n" 2136 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2137 " [,asset=str][,part=str]\n" 2138 " specify SMBIOS type 4 fields\n" 2139 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2140 " [,asset=str][,part=str][,speed=%d]\n" 2141 " specify SMBIOS type 17 fields\n", 2142 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2143STEXI 2144@item -smbios file=@var{binary} 2145@findex -smbios 2146Load SMBIOS entry from binary file. 2147 2148@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2149Specify SMBIOS type 0 fields 2150 2151@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}] 2152Specify SMBIOS type 1 fields 2153 2154@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2155Specify SMBIOS type 2 fields 2156 2157@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2158Specify SMBIOS type 3 fields 2159 2160@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2161Specify SMBIOS type 4 fields 2162 2163@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}] 2164Specify SMBIOS type 17 fields 2165ETEXI 2166 2167STEXI 2168@end table 2169ETEXI 2170DEFHEADING() 2171 2172DEFHEADING(Network options:) 2173STEXI 2174@table @option 2175ETEXI 2176 2177DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2178#ifdef CONFIG_SLIRP 2179 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2180 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2181 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2182 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2183 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2184#ifndef _WIN32 2185 "[,smb=dir[,smbserver=addr]]\n" 2186#endif 2187 " configure a user mode network backend with ID 'str',\n" 2188 " its DHCP server and optional services\n" 2189#endif 2190#ifdef _WIN32 2191 "-netdev tap,id=str,ifname=name\n" 2192 " configure a host TAP network backend with ID 'str'\n" 2193#else 2194 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2195 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2196 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2197 " [,poll-us=n]\n" 2198 " configure a host TAP network backend with ID 'str'\n" 2199 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2200 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2201 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2202 " to deconfigure it\n" 2203 " use '[down]script=no' to disable script execution\n" 2204 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2205 " configure it\n" 2206 " use 'fd=h' to connect to an already opened TAP interface\n" 2207 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2208 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2209 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2210 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2211 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2212 " use vhost=on to enable experimental in kernel accelerator\n" 2213 " (only has effect for virtio guests which use MSIX)\n" 2214 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2215 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2216 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2217 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2218 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2219 " spent on busy polling for vhost net\n" 2220 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2221 " configure a host TAP network backend with ID 'str' that is\n" 2222 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2223 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2224#endif 2225#ifdef __linux__ 2226 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2227 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2228 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2229 " [,rxcookie=rxcookie][,offset=offset]\n" 2230 " configure a network backend with ID 'str' connected to\n" 2231 " an Ethernet over L2TPv3 pseudowire.\n" 2232 " Linux kernel 3.3+ as well as most routers can talk\n" 2233 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2234 " VM to a router and even VM to Host. It is a nearly-universal\n" 2235 " standard (RFC3391). Note - this implementation uses static\n" 2236 " pre-configured tunnels (same as the Linux kernel).\n" 2237 " use 'src=' to specify source address\n" 2238 " use 'dst=' to specify destination address\n" 2239 " use 'udp=on' to specify udp encapsulation\n" 2240 " use 'srcport=' to specify source udp port\n" 2241 " use 'dstport=' to specify destination udp port\n" 2242 " use 'ipv6=on' to force v6\n" 2243 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2244 " well as a weak security measure\n" 2245 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2246 " use 'txcookie=0x012345678' to specify a txcookie\n" 2247 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2248 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2249 " use 'pincounter=on' to work around broken counter handling in peer\n" 2250 " use 'offset=X' to add an extra offset between header and data\n" 2251#endif 2252 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2253 " configure a network backend to connect to another network\n" 2254 " using a socket connection\n" 2255 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2256 " configure a network backend to connect to a multicast maddr and port\n" 2257 " use 'localaddr=addr' to specify the host address to send packets from\n" 2258 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2259 " configure a network backend to connect to another network\n" 2260 " using an UDP tunnel\n" 2261#ifdef CONFIG_VDE 2262 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2263 " configure a network backend to connect to port 'n' of a vde switch\n" 2264 " running on host and listening for incoming connections on 'socketpath'.\n" 2265 " Use group 'groupname' and mode 'octalmode' to change default\n" 2266 " ownership and permissions for communication port.\n" 2267#endif 2268#ifdef CONFIG_NETMAP 2269 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2270 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2271 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2272 " netmap device, defaults to '/dev/netmap')\n" 2273#endif 2274#ifdef CONFIG_POSIX 2275 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2276 " configure a vhost-user network, backed by a chardev 'dev'\n" 2277#endif 2278 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2279 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2280DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2281 "-nic [tap|bridge|" 2282#ifdef CONFIG_SLIRP 2283 "user|" 2284#endif 2285#ifdef __linux__ 2286 "l2tpv3|" 2287#endif 2288#ifdef CONFIG_VDE 2289 "vde|" 2290#endif 2291#ifdef CONFIG_NETMAP 2292 "netmap|" 2293#endif 2294#ifdef CONFIG_POSIX 2295 "vhost-user|" 2296#endif 2297 "socket][,option][,...][mac=macaddr]\n" 2298 " initialize an on-board / default host NIC (using MAC address\n" 2299 " macaddr) and connect it to the given host network backend\n" 2300 "-nic none use it alone to have zero network devices (the default is to\n" 2301 " provided a 'user' network connection)\n", 2302 QEMU_ARCH_ALL) 2303DEF("net", HAS_ARG, QEMU_OPTION_net, 2304 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2305 " configure or create an on-board (or machine default) NIC and\n" 2306 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2307 "-net [" 2308#ifdef CONFIG_SLIRP 2309 "user|" 2310#endif 2311 "tap|" 2312 "bridge|" 2313#ifdef CONFIG_VDE 2314 "vde|" 2315#endif 2316#ifdef CONFIG_NETMAP 2317 "netmap|" 2318#endif 2319 "socket][,option][,option][,...]\n" 2320 " old way to initialize a host network interface\n" 2321 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2322STEXI 2323@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2324@findex -nic 2325This option is a shortcut for configuring both the on-board (default) guest 2326NIC hardware and the host network backend in one go. The host backend options 2327are the same as with the corresponding @option{-netdev} options below. 2328The guest NIC model can be set with @option{model=@var{modelname}}. 2329Use @option{model=help} to list the available device types. 2330The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2331 2332The following two example do exactly the same, to show how @option{-nic} can 2333be used to shorten the command line length (note that the e1000 is the default 2334on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2335@example 2336@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2337@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2338@end example 2339 2340@item -nic none 2341Indicate that no network devices should be configured. It is used to override 2342the default configuration (default NIC with ``user'' host network backend) 2343which is activated if no other networking options are provided. 2344 2345@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2346@findex -netdev 2347Configure user mode host network backend which requires no administrator 2348privilege to run. Valid options are: 2349 2350@table @option 2351@item id=@var{id} 2352Assign symbolic name for use in monitor commands. 2353 2354@item ipv4=on|off and ipv6=on|off 2355Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2356both protocols are enabled. 2357 2358@item net=@var{addr}[/@var{mask}] 2359Set IP network address the guest will see. Optionally specify the netmask, 2360either in the form a.b.c.d or as number of valid top-most bits. Default is 236110.0.2.0/24. 2362 2363@item host=@var{addr} 2364Specify the guest-visible address of the host. Default is the 2nd IP in the 2365guest network, i.e. x.x.x.2. 2366 2367@item ipv6-net=@var{addr}[/@var{int}] 2368Set IPv6 network address the guest will see (default is fec0::/64). The 2369network prefix is given in the usual hexadecimal IPv6 address 2370notation. The prefix size is optional, and is given as the number of 2371valid top-most bits (default is 64). 2372 2373@item ipv6-host=@var{addr} 2374Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2375the guest network, i.e. xxxx::2. 2376 2377@item restrict=on|off 2378If this option is enabled, the guest will be isolated, i.e. it will not be 2379able to contact the host and no guest IP packets will be routed over the host 2380to the outside. This option does not affect any explicitly set forwarding rules. 2381 2382@item hostname=@var{name} 2383Specifies the client hostname reported by the built-in DHCP server. 2384 2385@item dhcpstart=@var{addr} 2386Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2387is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2388 2389@item dns=@var{addr} 2390Specify the guest-visible address of the virtual nameserver. The address must 2391be different from the host address. Default is the 3rd IP in the guest network, 2392i.e. x.x.x.3. 2393 2394@item ipv6-dns=@var{addr} 2395Specify the guest-visible address of the IPv6 virtual nameserver. The address 2396must be different from the host address. Default is the 3rd IP in the guest 2397network, i.e. xxxx::3. 2398 2399@item dnssearch=@var{domain} 2400Provides an entry for the domain-search list sent by the built-in 2401DHCP server. More than one domain suffix can be transmitted by specifying 2402this option multiple times. If supported, this will cause the guest to 2403automatically try to append the given domain suffix(es) in case a domain name 2404can not be resolved. 2405 2406Example: 2407@example 2408@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2409@end example 2410 2411@item domainname=@var{domain} 2412Specifies the client domain name reported by the built-in DHCP server. 2413 2414@item tftp=@var{dir} 2415When using the user mode network stack, activate a built-in TFTP 2416server. The files in @var{dir} will be exposed as the root of a TFTP server. 2417The TFTP client on the guest must be configured in binary mode (use the command 2418@code{bin} of the Unix TFTP client). 2419 2420@item tftp-server-name=@var{name} 2421In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 242266). This can be used to advise the guest to load boot files or configurations 2423from a different server than the host address. 2424 2425@item bootfile=@var{file} 2426When using the user mode network stack, broadcast @var{file} as the BOOTP 2427filename. In conjunction with @option{tftp}, this can be used to network boot 2428a guest from a local directory. 2429 2430Example (using pxelinux): 2431@example 2432@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2433 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2434@end example 2435 2436@item smb=@var{dir}[,smbserver=@var{addr}] 2437When using the user mode network stack, activate a built-in SMB 2438server so that Windows OSes can access to the host files in @file{@var{dir}} 2439transparently. The IP address of the SMB server can be set to @var{addr}. By 2440default the 4th IP in the guest network is used, i.e. x.x.x.4. 2441 2442In the guest Windows OS, the line: 2443@example 244410.0.2.4 smbserver 2445@end example 2446must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2447or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2448 2449Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2450 2451Note that a SAMBA server must be installed on the host OS. 2452 2453@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2454Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2455the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2456@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2457given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2458be bound to a specific host interface. If no connection type is set, TCP is 2459used. This option can be given multiple times. 2460 2461For example, to redirect host X11 connection from screen 1 to guest 2462screen 0, use the following: 2463 2464@example 2465# on the host 2466@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2467# this host xterm should open in the guest X11 server 2468xterm -display :1 2469@end example 2470 2471To redirect telnet connections from host port 5555 to telnet port on 2472the guest, use the following: 2473 2474@example 2475# on the host 2476@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2477telnet localhost 5555 2478@end example 2479 2480Then when you use on the host @code{telnet localhost 5555}, you 2481connect to the guest telnet server. 2482 2483@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2484@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2485Forward guest TCP connections to the IP address @var{server} on port @var{port} 2486to the character device @var{dev} or to a program executed by @var{cmd:command} 2487which gets spawned for each connection. This option can be given multiple times. 2488 2489You can either use a chardev directly and have that one used throughout QEMU's 2490lifetime, like in the following example: 2491 2492@example 2493# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2494# the guest accesses it 2495@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2496@end example 2497 2498Or you can execute a command on every TCP connection established by the guest, 2499so that QEMU behaves similar to an inetd process for that virtual server: 2500 2501@example 2502# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2503# and connect the TCP stream to its stdin/stdout 2504@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2505@end example 2506 2507@end table 2508 2509@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2510Configure a host TAP network backend with ID @var{id}. 2511 2512Use the network script @var{file} to configure it and the network script 2513@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2514automatically provides one. The default network configure script is 2515@file{/etc/qemu-ifup} and the default network deconfigure script is 2516@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2517to disable script execution. 2518 2519If running QEMU as an unprivileged user, use the network helper 2520@var{helper} to configure the TAP interface and attach it to the bridge. 2521The default network helper executable is @file{/path/to/qemu-bridge-helper} 2522and the default bridge device is @file{br0}. 2523 2524@option{fd}=@var{h} can be used to specify the handle of an already 2525opened host TAP interface. 2526 2527Examples: 2528 2529@example 2530#launch a QEMU instance with the default network script 2531@value{qemu_system} linux.img -nic tap 2532@end example 2533 2534@example 2535#launch a QEMU instance with two NICs, each one connected 2536#to a TAP device 2537@value{qemu_system} linux.img \ 2538 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2539 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2540@end example 2541 2542@example 2543#launch a QEMU instance with the default network helper to 2544#connect a TAP device to bridge br0 2545@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2546 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2547@end example 2548 2549@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2550Connect a host TAP network interface to a host bridge device. 2551 2552Use the network helper @var{helper} to configure the TAP interface and 2553attach it to the bridge. The default network helper executable is 2554@file{/path/to/qemu-bridge-helper} and the default bridge 2555device is @file{br0}. 2556 2557Examples: 2558 2559@example 2560#launch a QEMU instance with the default network helper to 2561#connect a TAP device to bridge br0 2562@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2563@end example 2564 2565@example 2566#launch a QEMU instance with the default network helper to 2567#connect a TAP device to bridge qemubr0 2568@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2569@end example 2570 2571@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2572 2573This host network backend can be used to connect the guest's network to 2574another QEMU virtual machine using a TCP socket connection. If @option{listen} 2575is specified, QEMU waits for incoming connections on @var{port} 2576(@var{host} is optional). @option{connect} is used to connect to 2577another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2578specifies an already opened TCP socket. 2579 2580Example: 2581@example 2582# launch a first QEMU instance 2583@value{qemu_system} linux.img \ 2584 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2585 -netdev socket,id=n1,listen=:1234 2586# connect the network of this instance to the network of the first instance 2587@value{qemu_system} linux.img \ 2588 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2589 -netdev socket,id=n2,connect=127.0.0.1:1234 2590@end example 2591 2592@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2593 2594Configure a socket host network backend to share the guest's network traffic 2595with another QEMU virtual machines using a UDP multicast socket, effectively 2596making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2597NOTES: 2598@enumerate 2599@item 2600Several QEMU can be running on different hosts and share same bus (assuming 2601correct multicast setup for these hosts). 2602@item 2603mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2604@url{http://user-mode-linux.sf.net}. 2605@item 2606Use @option{fd=h} to specify an already opened UDP multicast socket. 2607@end enumerate 2608 2609Example: 2610@example 2611# launch one QEMU instance 2612@value{qemu_system} linux.img \ 2613 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2614 -netdev socket,id=n1,mcast=230.0.0.1:1234 2615# launch another QEMU instance on same "bus" 2616@value{qemu_system} linux.img \ 2617 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2618 -netdev socket,id=n2,mcast=230.0.0.1:1234 2619# launch yet another QEMU instance on same "bus" 2620@value{qemu_system} linux.img \ 2621 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2622 -netdev socket,id=n3,mcast=230.0.0.1:1234 2623@end example 2624 2625Example (User Mode Linux compat.): 2626@example 2627# launch QEMU instance (note mcast address selected is UML's default) 2628@value{qemu_system} linux.img \ 2629 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2630 -netdev socket,id=n1,mcast=239.192.168.1:1102 2631# launch UML 2632/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2633@end example 2634 2635Example (send packets from host's 1.2.3.4): 2636@example 2637@value{qemu_system} linux.img \ 2638 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2639 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2640@end example 2641 2642@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}] 2643Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2644popular protocol to transport Ethernet (and other Layer 2) data frames between 2645two systems. It is present in routers, firewalls and the Linux kernel 2646(from version 3.3 onwards). 2647 2648This transport allows a VM to communicate to another VM, router or firewall directly. 2649 2650@table @option 2651@item src=@var{srcaddr} 2652 source address (mandatory) 2653@item dst=@var{dstaddr} 2654 destination address (mandatory) 2655@item udp 2656 select udp encapsulation (default is ip). 2657@item srcport=@var{srcport} 2658 source udp port. 2659@item dstport=@var{dstport} 2660 destination udp port. 2661@item ipv6 2662 force v6, otherwise defaults to v4. 2663@item rxcookie=@var{rxcookie} 2664@itemx txcookie=@var{txcookie} 2665 Cookies are a weak form of security in the l2tpv3 specification. 2666Their function is mostly to prevent misconfiguration. By default they are 32 2667bit. 2668@item cookie64 2669 Set cookie size to 64 bit instead of the default 32 2670@item counter=off 2671 Force a 'cut-down' L2TPv3 with no counter as in 2672draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2673@item pincounter=on 2674 Work around broken counter handling in peer. This may also help on 2675networks which have packet reorder. 2676@item offset=@var{offset} 2677 Add an extra offset between header and data 2678@end table 2679 2680For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2681on the remote Linux host 1.2.3.4: 2682@example 2683# Setup tunnel on linux host using raw ip as encapsulation 2684# on 1.2.3.4 2685ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2686 encap udp udp_sport 16384 udp_dport 16384 2687ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2688 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2689ifconfig vmtunnel0 mtu 1500 2690ifconfig vmtunnel0 up 2691brctl addif br-lan vmtunnel0 2692 2693 2694# on 4.3.2.1 2695# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2696 2697@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2698 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2699 2700@end example 2701 2702@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2703Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2704listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2705and MODE @var{octalmode} to change default ownership and permissions for 2706communication port. This option is only available if QEMU has been compiled 2707with vde support enabled. 2708 2709Example: 2710@example 2711# launch vde switch 2712vde_switch -F -sock /tmp/myswitch 2713# launch QEMU instance 2714@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2715@end example 2716 2717@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2718 2719Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2720be a unix domain socket backed one. The vhost-user uses a specifically defined 2721protocol to pass vhost ioctl replacement messages to an application on the other 2722end of the socket. On non-MSIX guests, the feature can be forced with 2723@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2724be created for multiqueue vhost-user. 2725 2726Example: 2727@example 2728qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2729 -numa node,memdev=mem \ 2730 -chardev socket,id=chr0,path=/path/to/socket \ 2731 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2732 -device virtio-net-pci,netdev=net0 2733@end example 2734 2735@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2736 2737Create a hub port on the emulated hub with ID @var{hubid}. 2738 2739The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2740single netdev. Alternatively, you can also connect the hubport to another 2741netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2742 2743@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2744@findex -net 2745Legacy option to configure or create an on-board (or machine default) Network 2746Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2747the default hub), or to the netdev @var{nd}. 2748The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2749can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2750only), and a @var{name} can be assigned for use in monitor commands. 2751Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2752that the card should have; this option currently only affects virtio cards; set 2753@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2754NIC is created. QEMU can emulate several different models of network card. 2755Use @code{-net nic,model=help} for a list of available devices for your target. 2756 2757@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2758Configure a host network backend (with the options corresponding to the same 2759@option{-netdev} option) and connect it to the emulated hub 0 (the default 2760hub). Use @var{name} to specify the name of the hub port. 2761ETEXI 2762 2763STEXI 2764@end table 2765ETEXI 2766DEFHEADING() 2767 2768DEFHEADING(Character device options:) 2769 2770DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2771 "-chardev help\n" 2772 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2773 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2774 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2775 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2776 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2777 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2778 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2779 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2780 " [,logfile=PATH][,logappend=on|off]\n" 2781 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2782 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2783 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2784 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2785 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2786 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2787#ifdef _WIN32 2788 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2789 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2790#else 2791 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2792 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2793#endif 2794#ifdef CONFIG_BRLAPI 2795 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2796#endif 2797#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2798 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2799 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2800 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2801#endif 2802#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2803 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2804 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2805#endif 2806#if defined(CONFIG_SPICE) 2807 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2808 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2809#endif 2810 , QEMU_ARCH_ALL 2811) 2812 2813STEXI 2814 2815The general form of a character device option is: 2816@table @option 2817@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2818@findex -chardev 2819Backend is one of: 2820@option{null}, 2821@option{socket}, 2822@option{udp}, 2823@option{msmouse}, 2824@option{vc}, 2825@option{ringbuf}, 2826@option{file}, 2827@option{pipe}, 2828@option{console}, 2829@option{serial}, 2830@option{pty}, 2831@option{stdio}, 2832@option{braille}, 2833@option{tty}, 2834@option{parallel}, 2835@option{parport}, 2836@option{spicevmc}, 2837@option{spiceport}. 2838The specific backend will determine the applicable options. 2839 2840Use @code{-chardev help} to print all available chardev backend types. 2841 2842All devices must have an id, which can be any string up to 127 characters long. 2843It is used to uniquely identify this device in other command line directives. 2844 2845A character device may be used in multiplexing mode by multiple front-ends. 2846Specify @option{mux=on} to enable this mode. 2847A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2848backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2849If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2850create a multiplexer with your specified ID, and you can then configure multiple 2851front ends to use that chardev ID for their input/output. Up to four different 2852front ends can be connected to a single multiplexed chardev. (Without 2853multiplexing enabled, a chardev can only be used by a single front end.) 2854For instance you could use this to allow a single stdio chardev to be used by 2855two serial ports and the QEMU monitor: 2856 2857@example 2858-chardev stdio,mux=on,id=char0 \ 2859-mon chardev=char0,mode=readline \ 2860-serial chardev:char0 \ 2861-serial chardev:char0 2862@end example 2863 2864You can have more than one multiplexer in a system configuration; for instance 2865you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2866multiplexed between the QEMU monitor and a parallel port: 2867 2868@example 2869-chardev stdio,mux=on,id=char0 \ 2870-mon chardev=char0,mode=readline \ 2871-parallel chardev:char0 \ 2872-chardev tcp,...,mux=on,id=char1 \ 2873-serial chardev:char1 \ 2874-serial chardev:char1 2875@end example 2876 2877When you're using a multiplexed character device, some escape sequences are 2878interpreted in the input. @xref{mux_keys, Keys in the character backend 2879multiplexer}. 2880 2881Note that some other command line options may implicitly create multiplexed 2882character backends; for instance @option{-serial mon:stdio} creates a 2883multiplexed stdio backend connected to the serial port and the QEMU monitor, 2884and @option{-nographic} also multiplexes the console and the monitor to 2885stdio. 2886 2887There is currently no support for multiplexing in the other direction 2888(where a single QEMU front end takes input and output from multiple chardevs). 2889 2890Every backend supports the @option{logfile} option, which supplies the path 2891to a file to record all data transmitted via the backend. The @option{logappend} 2892option controls whether the log file will be truncated or appended to when 2893opened. 2894 2895@end table 2896 2897The available backends are: 2898 2899@table @option 2900@item -chardev null,id=@var{id} 2901A void device. This device will not emit any data, and will drop any data it 2902receives. The null backend does not take any options. 2903 2904@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}] 2905 2906Create a two-way stream socket, which can be either a TCP or a unix socket. A 2907unix socket will be created if @option{path} is specified. Behaviour is 2908undefined if TCP options are specified for a unix socket. 2909 2910@option{server} specifies that the socket shall be a listening socket. 2911 2912@option{nowait} specifies that QEMU should not block waiting for a client to 2913connect to a listening socket. 2914 2915@option{telnet} specifies that traffic on the socket should interpret telnet 2916escape sequences. 2917 2918@option{websocket} specifies that the socket uses WebSocket protocol for 2919communication. 2920 2921@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2922the remote end goes away. qemu will delay this many seconds and then attempt 2923to reconnect. Zero disables reconnecting, and is the default. 2924 2925@option{tls-creds} requests enablement of the TLS protocol for encryption, 2926and specifies the id of the TLS credentials to use for the handshake. The 2927credentials must be previously created with the @option{-object tls-creds} 2928argument. 2929 2930@option{tls-auth} provides the ID of the QAuthZ authorization object against 2931which the client's x509 distinguished name will be validated. This object is 2932only resolved at time of use, so can be deleted and recreated on the fly 2933while the chardev server is active. If missing, it will default to denying 2934access. 2935 2936TCP and unix socket options are given below: 2937 2938@table @option 2939 2940@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2941 2942@option{host} for a listening socket specifies the local address to be bound. 2943For a connecting socket species the remote host to connect to. @option{host} is 2944optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2945 2946@option{port} for a listening socket specifies the local port to be bound. For a 2947connecting socket specifies the port on the remote host to connect to. 2948@option{port} can be given as either a port number or a service name. 2949@option{port} is required. 2950 2951@option{to} is only relevant to listening sockets. If it is specified, and 2952@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2953to and including @option{to} until it succeeds. @option{to} must be specified 2954as a port number. 2955 2956@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2957If neither is specified the socket may use either protocol. 2958 2959@option{nodelay} disables the Nagle algorithm. 2960 2961@item unix options: path=@var{path} 2962 2963@option{path} specifies the local path of the unix socket. @option{path} is 2964required. 2965 2966@end table 2967 2968@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2969 2970Sends all traffic from the guest to a remote host over UDP. 2971 2972@option{host} specifies the remote host to connect to. If not specified it 2973defaults to @code{localhost}. 2974 2975@option{port} specifies the port on the remote host to connect to. @option{port} 2976is required. 2977 2978@option{localaddr} specifies the local address to bind to. If not specified it 2979defaults to @code{0.0.0.0}. 2980 2981@option{localport} specifies the local port to bind to. If not specified any 2982available local port will be used. 2983 2984@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2985If neither is specified the device may use either protocol. 2986 2987@item -chardev msmouse,id=@var{id} 2988 2989Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2990take any options. 2991 2992@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 2993 2994Connect to a QEMU text console. @option{vc} may optionally be given a specific 2995size. 2996 2997@option{width} and @option{height} specify the width and height respectively of 2998the console, in pixels. 2999 3000@option{cols} and @option{rows} specify that the console be sized to fit a text 3001console with the given dimensions. 3002 3003@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 3004 3005Create a ring buffer with fixed size @option{size}. 3006@var{size} must be a power of two and defaults to @code{64K}. 3007 3008@item -chardev file,id=@var{id},path=@var{path} 3009 3010Log all traffic received from the guest to a file. 3011 3012@option{path} specifies the path of the file to be opened. This file will be 3013created if it does not already exist, and overwritten if it does. @option{path} 3014is required. 3015 3016@item -chardev pipe,id=@var{id},path=@var{path} 3017 3018Create a two-way connection to the guest. The behaviour differs slightly between 3019Windows hosts and other hosts: 3020 3021On Windows, a single duplex pipe will be created at 3022@file{\\.pipe\@option{path}}. 3023 3024On other hosts, 2 pipes will be created called @file{@option{path}.in} and 3025@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 3026received by the guest. Data written by the guest can be read from 3027@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 3028be present. 3029 3030@option{path} forms part of the pipe path as described above. @option{path} is 3031required. 3032 3033@item -chardev console,id=@var{id} 3034 3035Send traffic from the guest to QEMU's standard output. @option{console} does not 3036take any options. 3037 3038@option{console} is only available on Windows hosts. 3039 3040@item -chardev serial,id=@var{id},path=@option{path} 3041 3042Send traffic from the guest to a serial device on the host. 3043 3044On Unix hosts serial will actually accept any tty device, 3045not only serial lines. 3046 3047@option{path} specifies the name of the serial device to open. 3048 3049@item -chardev pty,id=@var{id} 3050 3051Create a new pseudo-terminal on the host and connect to it. @option{pty} does 3052not take any options. 3053 3054@option{pty} is not available on Windows hosts. 3055 3056@item -chardev stdio,id=@var{id}[,signal=on|off] 3057Connect to standard input and standard output of the QEMU process. 3058 3059@option{signal} controls if signals are enabled on the terminal, that includes 3060exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3061default, use @option{signal=off} to disable it. 3062 3063@item -chardev braille,id=@var{id} 3064 3065Connect to a local BrlAPI server. @option{braille} does not take any options. 3066 3067@item -chardev tty,id=@var{id},path=@var{path} 3068 3069@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3070DragonFlyBSD hosts. It is an alias for @option{serial}. 3071 3072@option{path} specifies the path to the tty. @option{path} is required. 3073 3074@item -chardev parallel,id=@var{id},path=@var{path} 3075@itemx -chardev parport,id=@var{id},path=@var{path} 3076 3077@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3078 3079Connect to a local parallel port. 3080 3081@option{path} specifies the path to the parallel port device. @option{path} is 3082required. 3083 3084@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3085 3086@option{spicevmc} is only available when spice support is built in. 3087 3088@option{debug} debug level for spicevmc 3089 3090@option{name} name of spice channel to connect to 3091 3092Connect to a spice virtual machine channel, such as vdiport. 3093 3094@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3095 3096@option{spiceport} is only available when spice support is built in. 3097 3098@option{debug} debug level for spicevmc 3099 3100@option{name} name of spice port to connect to 3101 3102Connect to a spice port, allowing a Spice client to handle the traffic 3103identified by a name (preferably a fqdn). 3104ETEXI 3105 3106STEXI 3107@end table 3108ETEXI 3109DEFHEADING() 3110 3111DEFHEADING(Bluetooth(R) options:) 3112STEXI 3113@table @option 3114ETEXI 3115 3116DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3117 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3118 "-bt hci,host[:id]\n" \ 3119 " use host's HCI with the given name\n" \ 3120 "-bt hci[,vlan=n]\n" \ 3121 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3122 "-bt vhci[,vlan=n]\n" \ 3123 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3124 "-bt device:dev[,vlan=n]\n" \ 3125 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3126 QEMU_ARCH_ALL) 3127STEXI 3128@item -bt hci[...] 3129@findex -bt 3130Defines the function of the corresponding Bluetooth HCI. -bt options 3131are matched with the HCIs present in the chosen machine type. For 3132example when emulating a machine with only one HCI built into it, only 3133the first @code{-bt hci[...]} option is valid and defines the HCI's 3134logic. The Transport Layer is decided by the machine type. Currently 3135the machines @code{n800} and @code{n810} have one HCI and all other 3136machines have none. 3137 3138Note: This option and the whole bluetooth subsystem is considered as deprecated. 3139If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where 3140you describe your usecase. 3141 3142@anchor{bt-hcis} 3143The following three types are recognized: 3144 3145@table @option 3146@item -bt hci,null 3147(default) The corresponding Bluetooth HCI assumes no internal logic 3148and will not respond to any HCI commands or emit events. 3149 3150@item -bt hci,host[:@var{id}] 3151(@code{bluez} only) The corresponding HCI passes commands / events 3152to / from the physical HCI identified by the name @var{id} (default: 3153@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3154capable systems like Linux. 3155 3156@item -bt hci[,vlan=@var{n}] 3157Add a virtual, standard HCI that will participate in the Bluetooth 3158scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3159VLANs, devices inside a bluetooth network @var{n} can only communicate 3160with other devices in the same network (scatternet). 3161@end table 3162 3163@item -bt vhci[,vlan=@var{n}] 3164(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3165to the host bluetooth stack instead of to the emulated target. This 3166allows the host and target machines to participate in a common scatternet 3167and communicate. Requires the Linux @code{vhci} driver installed. Can 3168be used as following: 3169 3170@example 3171@value{qemu_system} [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3172@end example 3173 3174@item -bt device:@var{dev}[,vlan=@var{n}] 3175Emulate a bluetooth device @var{dev} and place it in network @var{n} 3176(default @code{0}). QEMU can only emulate one type of bluetooth devices 3177currently: 3178 3179@table @option 3180@item keyboard 3181Virtual wireless keyboard implementing the HIDP bluetooth profile. 3182@end table 3183ETEXI 3184 3185STEXI 3186@end table 3187ETEXI 3188DEFHEADING() 3189 3190#ifdef CONFIG_TPM 3191DEFHEADING(TPM device options:) 3192 3193DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3194 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3195 " use path to provide path to a character device; default is /dev/tpm0\n" 3196 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3197 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3198 "-tpmdev emulator,id=id,chardev=dev\n" 3199 " configure the TPM device using chardev backend\n", 3200 QEMU_ARCH_ALL) 3201STEXI 3202 3203The general form of a TPM device option is: 3204@table @option 3205 3206@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3207@findex -tpmdev 3208 3209The specific backend type will determine the applicable options. 3210The @code{-tpmdev} option creates the TPM backend and requires a 3211@code{-device} option that specifies the TPM frontend interface model. 3212 3213Use @code{-tpmdev help} to print all available TPM backend types. 3214 3215@end table 3216 3217The available backends are: 3218 3219@table @option 3220 3221@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3222 3223(Linux-host only) Enable access to the host's TPM using the passthrough 3224driver. 3225 3226@option{path} specifies the path to the host's TPM device, i.e., on 3227a Linux host this would be @code{/dev/tpm0}. 3228@option{path} is optional and by default @code{/dev/tpm0} is used. 3229 3230@option{cancel-path} specifies the path to the host TPM device's sysfs 3231entry allowing for cancellation of an ongoing TPM command. 3232@option{cancel-path} is optional and by default QEMU will search for the 3233sysfs entry to use. 3234 3235Some notes about using the host's TPM with the passthrough driver: 3236 3237The TPM device accessed by the passthrough driver must not be 3238used by any other application on the host. 3239 3240Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3241the VM's firmware (BIOS/UEFI) will not be able to initialize the 3242TPM again and may therefore not show a TPM-specific menu that would 3243otherwise allow the user to configure the TPM, e.g., allow the user to 3244enable/disable or activate/deactivate the TPM. 3245Further, if TPM ownership is released from within a VM then the host's TPM 3246will get disabled and deactivated. To enable and activate the 3247TPM again afterwards, the host has to be rebooted and the user is 3248required to enter the firmware's menu to enable and activate the TPM. 3249If the TPM is left disabled and/or deactivated most TPM commands will fail. 3250 3251To create a passthrough TPM use the following two options: 3252@example 3253-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3254@end example 3255Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3256@code{tpmdev=tpm0} in the device option. 3257 3258@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3259 3260(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3261chardev backend. 3262 3263@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3264 3265To create a TPM emulator backend device with chardev socket backend: 3266@example 3267 3268-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3269 3270@end example 3271 3272ETEXI 3273 3274STEXI 3275@end table 3276ETEXI 3277DEFHEADING() 3278 3279#endif 3280 3281DEFHEADING(Linux/Multiboot boot specific:) 3282STEXI 3283 3284When using these options, you can use a given Linux or Multiboot 3285kernel without installing it in the disk image. It can be useful 3286for easier testing of various kernels. 3287 3288@table @option 3289ETEXI 3290 3291DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3292 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3293STEXI 3294@item -kernel @var{bzImage} 3295@findex -kernel 3296Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3297or in multiboot format. 3298ETEXI 3299 3300DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3301 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3302STEXI 3303@item -append @var{cmdline} 3304@findex -append 3305Use @var{cmdline} as kernel command line 3306ETEXI 3307 3308DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3309 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3310STEXI 3311@item -initrd @var{file} 3312@findex -initrd 3313Use @var{file} as initial ram disk. 3314 3315@item -initrd "@var{file1} arg=foo,@var{file2}" 3316 3317This syntax is only available with multiboot. 3318 3319Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3320first module. 3321ETEXI 3322 3323DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3324 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3325STEXI 3326@item -dtb @var{file} 3327@findex -dtb 3328Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3329on boot. 3330ETEXI 3331 3332STEXI 3333@end table 3334ETEXI 3335DEFHEADING() 3336 3337DEFHEADING(Debug/Expert options:) 3338STEXI 3339@table @option 3340ETEXI 3341 3342DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3343 "-fw_cfg [name=]<name>,file=<file>\n" 3344 " add named fw_cfg entry with contents from file\n" 3345 "-fw_cfg [name=]<name>,string=<str>\n" 3346 " add named fw_cfg entry with contents from string\n", 3347 QEMU_ARCH_ALL) 3348STEXI 3349 3350@item -fw_cfg [name=]@var{name},file=@var{file} 3351@findex -fw_cfg 3352Add named fw_cfg entry with contents from file @var{file}. 3353 3354@item -fw_cfg [name=]@var{name},string=@var{str} 3355Add named fw_cfg entry with contents from string @var{str}. 3356 3357The terminating NUL character of the contents of @var{str} will not be 3358included as part of the fw_cfg item data. To insert contents with 3359embedded NUL characters, you have to use the @var{file} parameter. 3360 3361The fw_cfg entries are passed by QEMU through to the guest. 3362 3363Example: 3364@example 3365 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3366@end example 3367creates an fw_cfg entry named opt/com.mycompany/blob with contents 3368from ./my_blob.bin. 3369 3370ETEXI 3371 3372DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3373 "-serial dev redirect the serial port to char device 'dev'\n", 3374 QEMU_ARCH_ALL) 3375STEXI 3376@item -serial @var{dev} 3377@findex -serial 3378Redirect the virtual serial port to host character device 3379@var{dev}. The default device is @code{vc} in graphical mode and 3380@code{stdio} in non graphical mode. 3381 3382This option can be used several times to simulate up to 4 serial 3383ports. 3384 3385Use @code{-serial none} to disable all serial ports. 3386 3387Available character devices are: 3388@table @option 3389@item vc[:@var{W}x@var{H}] 3390Virtual console. Optionally, a width and height can be given in pixel with 3391@example 3392vc:800x600 3393@end example 3394It is also possible to specify width or height in characters: 3395@example 3396vc:80Cx24C 3397@end example 3398@item pty 3399[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3400@item none 3401No device is allocated. 3402@item null 3403void device 3404@item chardev:@var{id} 3405Use a named character device defined with the @code{-chardev} option. 3406@item /dev/XXX 3407[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3408parameters are set according to the emulated ones. 3409@item /dev/parport@var{N} 3410[Linux only, parallel port only] Use host parallel port 3411@var{N}. Currently SPP and EPP parallel port features can be used. 3412@item file:@var{filename} 3413Write output to @var{filename}. No character can be read. 3414@item stdio 3415[Unix only] standard input/output 3416@item pipe:@var{filename} 3417name pipe @var{filename} 3418@item COM@var{n} 3419[Windows only] Use host serial port @var{n} 3420@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3421This implements UDP Net Console. 3422When @var{remote_host} or @var{src_ip} are not specified 3423they default to @code{0.0.0.0}. 3424When not using a specified @var{src_port} a random port is automatically chosen. 3425 3426If you just want a simple readonly console you can use @code{netcat} or 3427@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3428@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3429will appear in the netconsole session. 3430 3431If you plan to send characters back via netconsole or you want to stop 3432and start QEMU a lot of times, you should have QEMU use the same 3433source port each time by using something like @code{-serial 3434udp::4555@@:4556} to QEMU. Another approach is to use a patched 3435version of netcat which can listen to a TCP port and send and receive 3436characters via udp. If you have a patched version of netcat which 3437activates telnet remote echo and single char transfer, then you can 3438use the following options to set up a netcat redirector to allow 3439telnet on port 5555 to access the QEMU port. 3440@table @code 3441@item QEMU Options: 3442-serial udp::4555@@:4556 3443@item netcat options: 3444-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3445@item telnet options: 3446localhost 5555 3447@end table 3448 3449@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3450The TCP Net Console has two modes of operation. It can send the serial 3451I/O to a location or wait for a connection from a location. By default 3452the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3453the @var{server} option QEMU will wait for a client socket application 3454to connect to the port before continuing, unless the @code{nowait} 3455option was specified. The @code{nodelay} option disables the Nagle buffering 3456algorithm. The @code{reconnect} option only applies if @var{noserver} is 3457set, if the connection goes down it will attempt to reconnect at the 3458given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3459one TCP connection at a time is accepted. You can use @code{telnet} to 3460connect to the corresponding character device. 3461@table @code 3462@item Example to send tcp console to 192.168.0.2 port 4444 3463-serial tcp:192.168.0.2:4444 3464@item Example to listen and wait on port 4444 for connection 3465-serial tcp::4444,server 3466@item Example to not wait and listen on ip 192.168.0.100 port 4444 3467-serial tcp:192.168.0.100:4444,server,nowait 3468@end table 3469 3470@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3471The telnet protocol is used instead of raw tcp sockets. The options 3472work the same as if you had specified @code{-serial tcp}. The 3473difference is that the port acts like a telnet server or client using 3474telnet option negotiation. This will also allow you to send the 3475MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3476sequence. Typically in unix telnet you do it with Control-] and then 3477type "send break" followed by pressing the enter key. 3478 3479@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3480The WebSocket protocol is used instead of raw tcp socket. The port acts as 3481a WebSocket server. Client mode is not supported. 3482 3483@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3484A unix domain socket is used instead of a tcp socket. The option works the 3485same as if you had specified @code{-serial tcp} except the unix domain socket 3486@var{path} is used for connections. 3487 3488@item mon:@var{dev_string} 3489This is a special option to allow the monitor to be multiplexed onto 3490another serial port. The monitor is accessed with key sequence of 3491@key{Control-a} and then pressing @key{c}. 3492@var{dev_string} should be any one of the serial devices specified 3493above. An example to multiplex the monitor onto a telnet server 3494listening on port 4444 would be: 3495@table @code 3496@item -serial mon:telnet::4444,server,nowait 3497@end table 3498When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3499QEMU any more but will be passed to the guest instead. 3500 3501@item braille 3502Braille device. This will use BrlAPI to display the braille output on a real 3503or fake device. 3504 3505@item msmouse 3506Three button serial mouse. Configure the guest to use Microsoft protocol. 3507@end table 3508ETEXI 3509 3510DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3511 "-parallel dev redirect the parallel port to char device 'dev'\n", 3512 QEMU_ARCH_ALL) 3513STEXI 3514@item -parallel @var{dev} 3515@findex -parallel 3516Redirect the virtual parallel port to host device @var{dev} (same 3517devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3518be used to use hardware devices connected on the corresponding host 3519parallel port. 3520 3521This option can be used several times to simulate up to 3 parallel 3522ports. 3523 3524Use @code{-parallel none} to disable all parallel ports. 3525ETEXI 3526 3527DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3528 "-monitor dev redirect the monitor to char device 'dev'\n", 3529 QEMU_ARCH_ALL) 3530STEXI 3531@item -monitor @var{dev} 3532@findex -monitor 3533Redirect the monitor to host device @var{dev} (same devices as the 3534serial port). 3535The default device is @code{vc} in graphical mode and @code{stdio} in 3536non graphical mode. 3537Use @code{-monitor none} to disable the default monitor. 3538ETEXI 3539DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3540 "-qmp dev like -monitor but opens in 'control' mode\n", 3541 QEMU_ARCH_ALL) 3542STEXI 3543@item -qmp @var{dev} 3544@findex -qmp 3545Like -monitor but opens in 'control' mode. 3546ETEXI 3547DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3548 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3549 QEMU_ARCH_ALL) 3550STEXI 3551@item -qmp-pretty @var{dev} 3552@findex -qmp-pretty 3553Like -qmp but uses pretty JSON formatting. 3554ETEXI 3555 3556DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3557 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3558STEXI 3559@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3560@findex -mon 3561Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3562easing human reading and debugging. 3563ETEXI 3564 3565DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3566 "-debugcon dev redirect the debug console to char device 'dev'\n", 3567 QEMU_ARCH_ALL) 3568STEXI 3569@item -debugcon @var{dev} 3570@findex -debugcon 3571Redirect the debug console to host device @var{dev} (same devices as the 3572serial port). The debug console is an I/O port which is typically port 35730xe9; writing to that I/O port sends output to this device. 3574The default device is @code{vc} in graphical mode and @code{stdio} in 3575non graphical mode. 3576ETEXI 3577 3578DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3579 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3580STEXI 3581@item -pidfile @var{file} 3582@findex -pidfile 3583Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3584from a script. 3585ETEXI 3586 3587DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3588 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3589STEXI 3590@item -singlestep 3591@findex -singlestep 3592Run the emulation in single step mode. 3593ETEXI 3594 3595DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3596 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3597 QEMU_ARCH_ALL) 3598STEXI 3599@item --preconfig 3600@findex --preconfig 3601Pause QEMU for interactive configuration before the machine is created, 3602which allows querying and configuring properties that will affect 3603machine initialization. Use QMP command 'x-exit-preconfig' to exit 3604the preconfig state and move to the next state (i.e. run guest if -S 3605isn't used or pause the second time if -S is used). This option is 3606experimental. 3607ETEXI 3608 3609DEF("S", 0, QEMU_OPTION_S, \ 3610 "-S freeze CPU at startup (use 'c' to start execution)\n", 3611 QEMU_ARCH_ALL) 3612STEXI 3613@item -S 3614@findex -S 3615Do not start CPU at startup (you must type 'c' in the monitor). 3616ETEXI 3617 3618DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3619 "-realtime [mlock=on|off]\n" 3620 " run qemu with realtime features\n" 3621 " mlock=on|off controls mlock support (default: on)\n", 3622 QEMU_ARCH_ALL) 3623STEXI 3624@item -realtime mlock=on|off 3625@findex -realtime 3626Run qemu with realtime features. 3627mlocking qemu and guest memory can be enabled via @option{mlock=on} 3628(enabled by default). 3629ETEXI 3630 3631DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3632 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3633 " run qemu with overcommit hints\n" 3634 " mem-lock=on|off controls memory lock support (default: off)\n" 3635 " cpu-pm=on|off controls cpu power management (default: off)\n", 3636 QEMU_ARCH_ALL) 3637STEXI 3638@item -overcommit mem-lock=on|off 3639@item -overcommit cpu-pm=on|off 3640@findex -overcommit 3641Run qemu with hints about host resource overcommit. The default is 3642to assume that host overcommits all resources. 3643 3644Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3645by default). This works when host memory is not overcommitted and reduces the 3646worst-case latency for guest. This is equivalent to @option{realtime}. 3647 3648Guest ability to manage power state of host cpus (increasing latency for other 3649processes on the same host cpu, but decreasing latency for guest) can be 3650enabled via @option{cpu-pm=on} (disabled by default). This works best when 3651host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3652utilization will be incorrect, not taking into account guest idle time. 3653ETEXI 3654 3655DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3656 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3657STEXI 3658@item -gdb @var{dev} 3659@findex -gdb 3660Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3661connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3662stdio are reasonable use case. The latter is allowing to start QEMU from 3663within gdb and establish the connection via a pipe: 3664@example 3665(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3666@end example 3667ETEXI 3668 3669DEF("s", 0, QEMU_OPTION_s, \ 3670 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3671 QEMU_ARCH_ALL) 3672STEXI 3673@item -s 3674@findex -s 3675Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3676(@pxref{gdb_usage}). 3677ETEXI 3678 3679DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3680 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3681 QEMU_ARCH_ALL) 3682STEXI 3683@item -d @var{item1}[,...] 3684@findex -d 3685Enable logging of specified items. Use '-d help' for a list of log items. 3686ETEXI 3687 3688DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3689 "-D logfile output log to logfile (default stderr)\n", 3690 QEMU_ARCH_ALL) 3691STEXI 3692@item -D @var{logfile} 3693@findex -D 3694Output log in @var{logfile} instead of to stderr 3695ETEXI 3696 3697DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3698 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3699 QEMU_ARCH_ALL) 3700STEXI 3701@item -dfilter @var{range1}[,...] 3702@findex -dfilter 3703Filter debug output to that relevant to a range of target addresses. The filter 3704spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3705@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3706addresses and sizes required. For example: 3707@example 3708 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3709@end example 3710Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3711the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3712block starting at 0xffffffc00005f000. 3713ETEXI 3714 3715DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3716 "-seed number seed the pseudo-random number generator\n", 3717 QEMU_ARCH_ALL) 3718STEXI 3719@item -seed @var{number} 3720@findex -seed 3721Force the guest to use a deterministic pseudo-random number generator, seeded 3722with @var{number}. This does not affect crypto routines within the host. 3723ETEXI 3724 3725DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3726 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3727 QEMU_ARCH_ALL) 3728STEXI 3729@item -L @var{path} 3730@findex -L 3731Set the directory for the BIOS, VGA BIOS and keymaps. 3732 3733To list all the data directories, use @code{-L help}. 3734ETEXI 3735 3736DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3737 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3738STEXI 3739@item -bios @var{file} 3740@findex -bios 3741Set the filename for the BIOS. 3742ETEXI 3743 3744DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3745 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3746STEXI 3747@item -enable-kvm 3748@findex -enable-kvm 3749Enable KVM full virtualization support. This option is only available 3750if KVM support is enabled when compiling. 3751ETEXI 3752 3753DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3754 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3755DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3756 "-xen-attach attach to existing xen domain\n" 3757 " libxl will use this when starting QEMU\n", 3758 QEMU_ARCH_ALL) 3759DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3760 "-xen-domid-restrict restrict set of available xen operations\n" 3761 " to specified domain id. (Does not affect\n" 3762 " xenpv machine type).\n", 3763 QEMU_ARCH_ALL) 3764STEXI 3765@item -xen-domid @var{id} 3766@findex -xen-domid 3767Specify xen guest domain @var{id} (XEN only). 3768@item -xen-attach 3769@findex -xen-attach 3770Attach to existing xen domain. 3771libxl will use this when starting QEMU (XEN only). 3772@findex -xen-domid-restrict 3773Restrict set of available xen operations to specified domain id (XEN only). 3774ETEXI 3775 3776DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3777 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3778STEXI 3779@item -no-reboot 3780@findex -no-reboot 3781Exit instead of rebooting. 3782ETEXI 3783 3784DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3785 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3786STEXI 3787@item -no-shutdown 3788@findex -no-shutdown 3789Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3790This allows for instance switching to monitor to commit changes to the 3791disk image. 3792ETEXI 3793 3794DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3795 "-loadvm [tag|id]\n" \ 3796 " start right away with a saved state (loadvm in monitor)\n", 3797 QEMU_ARCH_ALL) 3798STEXI 3799@item -loadvm @var{file} 3800@findex -loadvm 3801Start right away with a saved state (@code{loadvm} in monitor) 3802ETEXI 3803 3804#ifndef _WIN32 3805DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3806 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3807#endif 3808STEXI 3809@item -daemonize 3810@findex -daemonize 3811Daemonize the QEMU process after initialization. QEMU will not detach from 3812standard IO until it is ready to receive connections on any of its devices. 3813This option is a useful way for external programs to launch QEMU without having 3814to cope with initialization race conditions. 3815ETEXI 3816 3817DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3818 "-option-rom rom load a file, rom, into the option ROM space\n", 3819 QEMU_ARCH_ALL) 3820STEXI 3821@item -option-rom @var{file} 3822@findex -option-rom 3823Load the contents of @var{file} as an option ROM. 3824This option is useful to load things like EtherBoot. 3825ETEXI 3826 3827DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3828 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3829 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3830 QEMU_ARCH_ALL) 3831 3832STEXI 3833 3834@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3835@findex -rtc 3836Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3837UTC or local time, respectively. @code{localtime} is required for correct date in 3838MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3839format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3840 3841By default the RTC is driven by the host system time. This allows using of the 3842RTC as accurate reference clock inside the guest, specifically if the host 3843time is smoothly following an accurate external reference clock, e.g. via NTP. 3844If you want to isolate the guest time from the host, you can set @option{clock} 3845to @code{rt} instead, which provides a host monotonic clock if host support it. 3846To even prevent the RTC from progressing during suspension, you can set @option{clock} 3847to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3848icount mode in order to preserve determinism; however, note that in icount mode 3849the speed of the virtual clock is variable and can in general differ from the 3850host clock. 3851 3852Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3853specifically with Windows' ACPI HAL. This option will try to figure out how 3854many timer interrupts were not processed by the Windows guest and will 3855re-inject them. 3856ETEXI 3857 3858DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3859 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3860 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3861 " instruction, enable aligning the host and virtual clocks\n" \ 3862 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3863STEXI 3864@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3865@findex -icount 3866Enable virtual instruction counter. The virtual cpu will execute one 3867instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3868then the virtual cpu speed will be automatically adjusted to keep virtual 3869time within a few seconds of real time. 3870 3871When the virtual cpu is sleeping, the virtual time will advance at default 3872speed unless @option{sleep=on|off} is specified. 3873With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3874instantly whenever the virtual cpu goes to sleep mode and will not advance 3875if no timer is enabled. This behavior give deterministic execution times from 3876the guest point of view. 3877 3878Note that while this option can give deterministic behavior, it does not 3879provide cycle accurate emulation. Modern CPUs contain superscalar out of 3880order cores with complex cache hierarchies. The number of instructions 3881executed often has little or no correlation with actual performance. 3882 3883@option{align=on} will activate the delay algorithm which will try 3884to synchronise the host clock and the virtual clock. The goal is to 3885have a guest running at the real frequency imposed by the shift option. 3886Whenever the guest clock is behind the host clock and if 3887@option{align=on} is specified then we print a message to the user 3888to inform about the delay. 3889Currently this option does not work when @option{shift} is @code{auto}. 3890Note: The sync algorithm will work for those shift values for which 3891the guest clock runs ahead of the host clock. Typically this happens 3892when the shift value is high (how high depends on the host machine). 3893 3894When @option{rr} option is specified deterministic record/replay is enabled. 3895Replay log is written into @var{filename} file in record mode and 3896read from this file in replay mode. 3897 3898Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3899at the start of execution recording. In replay mode this option is used 3900to load the initial VM state. 3901ETEXI 3902 3903DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3904 "-watchdog model\n" \ 3905 " enable virtual hardware watchdog [default=none]\n", 3906 QEMU_ARCH_ALL) 3907STEXI 3908@item -watchdog @var{model} 3909@findex -watchdog 3910Create a virtual hardware watchdog device. Once enabled (by a guest 3911action), the watchdog must be periodically polled by an agent inside 3912the guest or else the guest will be restarted. Choose a model for 3913which your guest has drivers. 3914 3915The @var{model} is the model of hardware watchdog to emulate. Use 3916@code{-watchdog help} to list available hardware models. Only one 3917watchdog can be enabled for a guest. 3918 3919The following models may be available: 3920@table @option 3921@item ib700 3922iBASE 700 is a very simple ISA watchdog with a single timer. 3923@item i6300esb 3924Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3925dual-timer watchdog. 3926@item diag288 3927A virtual watchdog for s390x backed by the diagnose 288 hypercall 3928(currently KVM only). 3929@end table 3930ETEXI 3931 3932DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3933 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3934 " action when watchdog fires [default=reset]\n", 3935 QEMU_ARCH_ALL) 3936STEXI 3937@item -watchdog-action @var{action} 3938@findex -watchdog-action 3939 3940The @var{action} controls what QEMU will do when the watchdog timer 3941expires. 3942The default is 3943@code{reset} (forcefully reset the guest). 3944Other possible actions are: 3945@code{shutdown} (attempt to gracefully shutdown the guest), 3946@code{poweroff} (forcefully poweroff the guest), 3947@code{inject-nmi} (inject a NMI into the guest), 3948@code{pause} (pause the guest), 3949@code{debug} (print a debug message and continue), or 3950@code{none} (do nothing). 3951 3952Note that the @code{shutdown} action requires that the guest responds 3953to ACPI signals, which it may not be able to do in the sort of 3954situations where the watchdog would have expired, and thus 3955@code{-watchdog-action shutdown} is not recommended for production use. 3956 3957Examples: 3958 3959@table @code 3960@item -watchdog i6300esb -watchdog-action pause 3961@itemx -watchdog ib700 3962@end table 3963ETEXI 3964 3965DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3966 "-echr chr set terminal escape character instead of ctrl-a\n", 3967 QEMU_ARCH_ALL) 3968STEXI 3969 3970@item -echr @var{numeric_ascii_value} 3971@findex -echr 3972Change the escape character used for switching to the monitor when using 3973monitor and serial sharing. The default is @code{0x01} when using the 3974@code{-nographic} option. @code{0x01} is equal to pressing 3975@code{Control-a}. You can select a different character from the ascii 3976control keys where 1 through 26 map to Control-a through Control-z. For 3977instance you could use the either of the following to change the escape 3978character to Control-t. 3979@table @code 3980@item -echr 0x14 3981@itemx -echr 20 3982@end table 3983ETEXI 3984 3985DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3986 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3987STEXI 3988@item -show-cursor 3989@findex -show-cursor 3990Show cursor. 3991ETEXI 3992 3993DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3994 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3995STEXI 3996@item -tb-size @var{n} 3997@findex -tb-size 3998Set TB size. 3999ETEXI 4000 4001DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 4002 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 4003 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 4004 "-incoming unix:socketpath\n" \ 4005 " prepare for incoming migration, listen on\n" \ 4006 " specified protocol and socket address\n" \ 4007 "-incoming fd:fd\n" \ 4008 "-incoming exec:cmdline\n" \ 4009 " accept incoming migration on given file descriptor\n" \ 4010 " or from given external command\n" \ 4011 "-incoming defer\n" \ 4012 " wait for the URI to be specified via migrate_incoming\n", 4013 QEMU_ARCH_ALL) 4014STEXI 4015@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 4016@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 4017@findex -incoming 4018Prepare for incoming migration, listen on a given tcp port. 4019 4020@item -incoming unix:@var{socketpath} 4021Prepare for incoming migration, listen on a given unix socket. 4022 4023@item -incoming fd:@var{fd} 4024Accept incoming migration from a given filedescriptor. 4025 4026@item -incoming exec:@var{cmdline} 4027Accept incoming migration as an output from specified external command. 4028 4029@item -incoming defer 4030Wait for the URI to be specified via migrate_incoming. The monitor can 4031be used to change settings (such as migration parameters) prior to issuing 4032the migrate_incoming to allow the migration to begin. 4033ETEXI 4034 4035DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 4036 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 4037STEXI 4038@item -only-migratable 4039@findex -only-migratable 4040Only allow migratable devices. Devices will not be allowed to enter an 4041unmigratable state. 4042ETEXI 4043 4044DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 4045 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 4046STEXI 4047@item -nodefaults 4048@findex -nodefaults 4049Don't create default devices. Normally, QEMU sets the default devices like serial 4050port, parallel port, virtual console, monitor device, VGA adapter, floppy and 4051CD-ROM drive and others. The @code{-nodefaults} option will disable all those 4052default devices. 4053ETEXI 4054 4055#ifndef _WIN32 4056DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 4057 "-chroot dir chroot to dir just before starting the VM\n", 4058 QEMU_ARCH_ALL) 4059#endif 4060STEXI 4061@item -chroot @var{dir} 4062@findex -chroot 4063Immediately before starting guest execution, chroot to the specified 4064directory. Especially useful in combination with -runas. 4065ETEXI 4066 4067#ifndef _WIN32 4068DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4069 "-runas user change to user id user just before starting the VM\n" \ 4070 " user can be numeric uid:gid instead\n", 4071 QEMU_ARCH_ALL) 4072#endif 4073STEXI 4074@item -runas @var{user} 4075@findex -runas 4076Immediately before starting guest execution, drop root privileges, switching 4077to the specified user. 4078ETEXI 4079 4080DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4081 "-prom-env variable=value\n" 4082 " set OpenBIOS nvram variables\n", 4083 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4084STEXI 4085@item -prom-env @var{variable}=@var{value} 4086@findex -prom-env 4087Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4088ETEXI 4089DEF("semihosting", 0, QEMU_OPTION_semihosting, 4090 "-semihosting semihosting mode\n", 4091 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4092 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4093STEXI 4094@item -semihosting 4095@findex -semihosting 4096Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4097ETEXI 4098DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4099 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4100 " semihosting configuration\n", 4101QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4102QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4103STEXI 4104@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4105@findex -semihosting-config 4106Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4107@table @option 4108@item target=@code{native|gdb|auto} 4109Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4110or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4111during debug sessions and @code{native} otherwise. 4112@item chardev=@var{str1} 4113Send the output to a chardev backend output for native or auto output when not in gdb 4114@item arg=@var{str1},arg=@var{str2},... 4115Allows the user to pass input arguments, and can be used multiple times to build 4116up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4117command line is still supported for backward compatibility. If both the 4118@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4119specified, the former is passed to semihosting as it always takes precedence. 4120@end table 4121ETEXI 4122DEF("old-param", 0, QEMU_OPTION_old_param, 4123 "-old-param old param mode\n", QEMU_ARCH_ARM) 4124STEXI 4125@item -old-param 4126@findex -old-param (ARM) 4127Old param mode (ARM only). 4128ETEXI 4129 4130DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4131 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4132 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4133 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4134 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4135 " by the kernel, but typically no longer used by modern\n" \ 4136 " C library implementations.\n" \ 4137 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4138 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4139 " The value 'children' will deny set*uid|gid system calls for\n" \ 4140 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4141 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4142 " blacklisting *fork and execve\n" \ 4143 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4144 QEMU_ARCH_ALL) 4145STEXI 4146@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4147@findex -sandbox 4148Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4149disable it. The default is 'off'. 4150@table @option 4151@item obsolete=@var{string} 4152Enable Obsolete system calls 4153@item elevateprivileges=@var{string} 4154Disable set*uid|gid system calls 4155@item spawn=@var{string} 4156Disable *fork and execve 4157@item resourcecontrol=@var{string} 4158Disable process affinity and schedular priority 4159@end table 4160ETEXI 4161 4162DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4163 "-readconfig <file>\n", QEMU_ARCH_ALL) 4164STEXI 4165@item -readconfig @var{file} 4166@findex -readconfig 4167Read device configuration from @var{file}. This approach is useful when you want to spawn 4168QEMU process with many command line options but you don't want to exceed the command line 4169character limit. 4170ETEXI 4171DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4172 "-writeconfig <file>\n" 4173 " read/write config file\n", QEMU_ARCH_ALL) 4174STEXI 4175@item -writeconfig @var{file} 4176@findex -writeconfig 4177Write device configuration to @var{file}. The @var{file} can be either filename to save 4178command line and device configuration into file or dash @code{-}) character to print the 4179output to stdout. This can be later used as input file for @code{-readconfig} option. 4180ETEXI 4181 4182DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4183 "-no-user-config\n" 4184 " do not load default user-provided config files at startup\n", 4185 QEMU_ARCH_ALL) 4186STEXI 4187@item -no-user-config 4188@findex -no-user-config 4189The @code{-no-user-config} option makes QEMU not load any of the user-provided 4190config files on @var{sysconfdir}. 4191ETEXI 4192 4193DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4194 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4195 " specify tracing options\n", 4196 QEMU_ARCH_ALL) 4197STEXI 4198HXCOMM This line is not accurate, as some sub-options are backend-specific but 4199HXCOMM HX does not support conditional compilation of text. 4200@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4201@findex -trace 4202@include qemu-option-trace.texi 4203ETEXI 4204DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4205 "-plugin [file=]<file>[,arg=<string>]\n" 4206 " load a plugin\n", 4207 QEMU_ARCH_ALL) 4208STEXI 4209@item -plugin file=@var{file}[,arg=@var{string}] 4210@findex -plugin 4211 4212Load a plugin. 4213 4214@table @option 4215@item file=@var{file} 4216Load the given plugin from a shared library file. 4217@item arg=@var{string} 4218Argument string passed to the plugin. (Can be given multiple times.) 4219@end table 4220ETEXI 4221 4222HXCOMM Internal use 4223DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4224DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4225 4226#ifdef __linux__ 4227DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4228 "-enable-fips enable FIPS 140-2 compliance\n", 4229 QEMU_ARCH_ALL) 4230#endif 4231STEXI 4232@item -enable-fips 4233@findex -enable-fips 4234Enable FIPS 140-2 compliance mode. 4235ETEXI 4236 4237HXCOMM Deprecated by -accel tcg 4238DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4239 4240DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4241 "-msg timestamp[=on|off]\n" 4242 " change the format of messages\n" 4243 " on|off controls leading timestamps (default:on)\n", 4244 QEMU_ARCH_ALL) 4245STEXI 4246@item -msg timestamp[=on|off] 4247@findex -msg 4248prepend a timestamp to each log message.(default:on) 4249ETEXI 4250 4251DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4252 "-dump-vmstate <file>\n" 4253 " Output vmstate information in JSON format to file.\n" 4254 " Use the scripts/vmstate-static-checker.py file to\n" 4255 " check for possible regressions in migration code\n" 4256 " by comparing two such vmstate dumps.\n", 4257 QEMU_ARCH_ALL) 4258STEXI 4259@item -dump-vmstate @var{file} 4260@findex -dump-vmstate 4261Dump json-encoded vmstate information for current machine type to file 4262in @var{file} 4263ETEXI 4264 4265DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4266 "-enable-sync-profile\n" 4267 " enable synchronization profiling\n", 4268 QEMU_ARCH_ALL) 4269STEXI 4270@item -enable-sync-profile 4271@findex -enable-sync-profile 4272Enable synchronization profiling. 4273ETEXI 4274 4275STEXI 4276@end table 4277ETEXI 4278DEFHEADING() 4279 4280DEFHEADING(Generic object creation:) 4281STEXI 4282@table @option 4283ETEXI 4284 4285DEF("object", HAS_ARG, QEMU_OPTION_object, 4286 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4287 " create a new object of type TYPENAME setting properties\n" 4288 " in the order they are specified. Note that the 'id'\n" 4289 " property must be set. These objects are placed in the\n" 4290 " '/objects' path.\n", 4291 QEMU_ARCH_ALL) 4292STEXI 4293@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4294@findex -object 4295Create a new object of type @var{typename} setting properties 4296in the order they are specified. Note that the 'id' 4297property must be set. These objects are placed in the 4298'/objects' path. 4299 4300@table @option 4301 4302@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} 4303 4304Creates a memory file backend object, which can be used to back 4305the guest RAM with huge pages. 4306 4307The @option{id} parameter is a unique ID that will be used to reference this 4308memory region when configuring the @option{-numa} argument. 4309 4310The @option{size} option provides the size of the memory region, and accepts 4311common suffixes, eg @option{500M}. 4312 4313The @option{mem-path} provides the path to either a shared memory or huge page 4314filesystem mount. 4315 4316The @option{share} boolean option determines whether the memory 4317region is marked as private to QEMU, or shared. The latter allows 4318a co-operating external process to access the QEMU memory region. 4319 4320The @option{share} is also required for pvrdma devices due to 4321limitations in the RDMA API provided by Linux. 4322 4323Setting share=on might affect the ability to configure NUMA 4324bindings for the memory backend under some circumstances, see 4325Documentation/vm/numa_memory_policy.txt on the Linux kernel 4326source tree for additional details. 4327 4328Setting the @option{discard-data} boolean option to @var{on} 4329indicates that file contents can be destroyed when QEMU exits, 4330to avoid unnecessarily flushing data to the backing file. Note 4331that @option{discard-data} is only an optimization, and QEMU 4332might not discard file contents if it aborts unexpectedly or is 4333terminated using SIGKILL. 4334 4335The @option{merge} boolean option enables memory merge, also known as 4336MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4337memory deduplication. 4338 4339Setting the @option{dump} boolean option to @var{off} excludes the memory from 4340core dumps. This feature is also known as MADV_DONTDUMP. 4341 4342The @option{prealloc} boolean option enables memory preallocation. 4343 4344The @option{host-nodes} option binds the memory range to a list of NUMA host 4345nodes. 4346 4347The @option{policy} option sets the NUMA policy to one of the following values: 4348 4349@table @option 4350@item @var{default} 4351default host policy 4352 4353@item @var{preferred} 4354prefer the given host node list for allocation 4355 4356@item @var{bind} 4357restrict memory allocation to the given host node list 4358 4359@item @var{interleave} 4360interleave memory allocations across the given host node list 4361@end table 4362 4363The @option{align} option specifies the base address alignment when 4364QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4365@option{2M}. Some backend store specified by @option{mem-path} 4366requires an alignment different than the default one used by QEMU, eg 4367the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4368such cases, users can specify the required alignment via this option. 4369 4370The @option{pmem} option specifies whether the backing file specified 4371by @option{mem-path} is in host persistent memory that can be accessed 4372using the SNIA NVM programming model (e.g. Intel NVDIMM). 4373If @option{pmem} is set to 'on', QEMU will take necessary operations to 4374guarantee the persistence of its own writes to @option{mem-path} 4375(e.g. in vNVDIMM label emulation and live migration). 4376Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4377file metadata is in sync for @option{mem-path} in case of host crash 4378or a power failure. MAP_SYNC requires support from both the host kernel 4379(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4380with DAX option. 4381 4382@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} 4383 4384Creates a memory backend object, which can be used to back the guest RAM. 4385Memory backend objects offer more control than the @option{-m} option that is 4386traditionally used to define guest RAM. Please refer to 4387@option{memory-backend-file} for a description of the options. 4388 4389@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} 4390 4391Creates an anonymous memory file backend object, which allows QEMU to 4392share the memory with an external process (e.g. when using 4393vhost-user). The memory is allocated with memfd and optional 4394sealing. (Linux only) 4395 4396The @option{seal} option creates a sealed-file, that will block 4397further resizing the memory ('on' by default). 4398 4399The @option{hugetlb} option specify the file to be created resides in 4400the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4401the @option{hugetlb} option, the @option{hugetlbsize} option specify 4402the hugetlb page size on systems that support multiple hugetlb page 4403sizes (it must be a power of 2 value supported by the system). 4404 4405In some versions of Linux, the @option{hugetlb} option is incompatible 4406with the @option{seal} option (requires at least Linux 4.16). 4407 4408Please refer to @option{memory-backend-file} for a description of the 4409other options. 4410 4411The @option{share} boolean option is @var{on} by default with memfd. 4412 4413@item -object rng-builtin,id=@var{id} 4414 4415Creates a random number generator backend which obtains entropy from 4416QEMU builtin functions. The @option{id} parameter is a unique ID that 4417will be used to reference this entropy backend from the @option{virtio-rng} 4418device. By default, the @option{virtio-rng} device uses this RNG backend. 4419 4420@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4421 4422Creates a random number generator backend which obtains entropy from 4423a device on the host. The @option{id} parameter is a unique ID that 4424will be used to reference this entropy backend from the @option{virtio-rng} 4425device. The @option{filename} parameter specifies which file to obtain 4426entropy from and if omitted defaults to @option{/dev/urandom}. 4427 4428@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4429 4430Creates a random number generator backend which obtains entropy from 4431an external daemon running on the host. The @option{id} parameter is 4432a unique ID that will be used to reference this entropy backend from 4433the @option{virtio-rng} device. The @option{chardev} parameter is 4434the unique ID of a character device backend that provides the connection 4435to the RNG daemon. 4436 4437@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4438 4439Creates a TLS anonymous credentials object, which can be used to provide 4440TLS support on network backends. The @option{id} parameter is a unique 4441ID which network backends will use to access the credentials. The 4442@option{endpoint} is either @option{server} or @option{client} depending 4443on whether the QEMU network backend that uses the credentials will be 4444acting as a client or as a server. If @option{verify-peer} is enabled 4445(the default) then once the handshake is completed, the peer credentials 4446will be verified, though this is a no-op for anonymous credentials. 4447 4448The @var{dir} parameter tells QEMU where to find the credential 4449files. For server endpoints, this directory may contain a file 4450@var{dh-params.pem} providing diffie-hellman parameters to use 4451for the TLS server. If the file is missing, QEMU will generate 4452a set of DH parameters at startup. This is a computationally 4453expensive operation that consumes random pool entropy, so it is 4454recommended that a persistent set of parameters be generated 4455upfront and saved. 4456 4457@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4458 4459Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4460TLS support on network backends. The @option{id} parameter is a unique 4461ID which network backends will use to access the credentials. The 4462@option{endpoint} is either @option{server} or @option{client} depending 4463on whether the QEMU network backend that uses the credentials will be 4464acting as a client or as a server. For clients only, @option{username} 4465is the username which will be sent to the server. If omitted 4466it defaults to ``qemu''. 4467 4468The @var{dir} parameter tells QEMU where to find the keys file. 4469It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4470pairs. This file can most easily be created using the GnuTLS 4471@code{psktool} program. 4472 4473For server endpoints, @var{dir} may also contain a file 4474@var{dh-params.pem} providing diffie-hellman parameters to use 4475for the TLS server. If the file is missing, QEMU will generate 4476a set of DH parameters at startup. This is a computationally 4477expensive operation that consumes random pool entropy, so it is 4478recommended that a persistent set of parameters be generated 4479up front and saved. 4480 4481@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} 4482 4483Creates a TLS anonymous credentials object, which can be used to provide 4484TLS support on network backends. The @option{id} parameter is a unique 4485ID which network backends will use to access the credentials. The 4486@option{endpoint} is either @option{server} or @option{client} depending 4487on whether the QEMU network backend that uses the credentials will be 4488acting as a client or as a server. If @option{verify-peer} is enabled 4489(the default) then once the handshake is completed, the peer credentials 4490will be verified. With x509 certificates, this implies that the clients 4491must be provided with valid client certificates too. 4492 4493The @var{dir} parameter tells QEMU where to find the credential 4494files. For server endpoints, this directory may contain a file 4495@var{dh-params.pem} providing diffie-hellman parameters to use 4496for the TLS server. If the file is missing, QEMU will generate 4497a set of DH parameters at startup. This is a computationally 4498expensive operation that consumes random pool entropy, so it is 4499recommended that a persistent set of parameters be generated 4500upfront and saved. 4501 4502For x509 certificate credentials the directory will contain further files 4503providing the x509 certificates. The certificates must be stored 4504in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4505@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4506@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4507 4508For the @var{server-key.pem} and @var{client-key.pem} files which 4509contain sensitive private keys, it is possible to use an encrypted 4510version by providing the @var{passwordid} parameter. This provides 4511the ID of a previously created @code{secret} object containing the 4512password for decryption. 4513 4514The @var{priority} parameter allows to override the global default 4515priority used by gnutls. This can be useful if the system administrator 4516needs to use a weaker set of crypto priorities for QEMU without 4517potentially forcing the weakness onto all applications. Or conversely 4518if one wants wants a stronger default for QEMU than for all other 4519applications, they can do this through this parameter. Its format is 4520a gnutls priority string as described at 4521@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4522 4523@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4524 4525Interval @var{t} can't be 0, this filter batches the packet delivery: all 4526packets arriving in a given interval on netdev @var{netdevid} are delayed 4527until the end of the interval. Interval is in microseconds. 4528@option{status} is optional that indicate whether the netfilter is 4529on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4530 4531queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4532 4533@option{all}: the filter is attached both to the receive and the transmit 4534 queue of the netdev (default). 4535 4536@option{rx}: the filter is attached to the receive queue of the netdev, 4537 where it will receive packets sent to the netdev. 4538 4539@option{tx}: the filter is attached to the transmit queue of the netdev, 4540 where it will receive packets sent by the netdev. 4541 4542@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4543 4544filter-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. 4545 4546@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4547 4548filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4549@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4550filter-redirector will redirect packet with vnet_hdr_len. 4551Create a filter-redirector we need to differ outdev id from indev id, id can not 4552be the same. we can just use indev or outdev, but at least one of indev or outdev 4553need to be specified. 4554 4555@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4556 4557Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4558secondary from primary to keep secondary tcp connection,and rewrite 4559tcp packet to primary from secondary make tcp packet can be handled by 4560client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4561 4562usage: 4563colo secondary: 4564-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4565-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4566-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4567 4568@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4569 4570Dump the network traffic on netdev @var{dev} to the file specified by 4571@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4572The file format is libpcap, so it can be analyzed with tools such as tcpdump 4573or Wireshark. 4574 4575@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}] 4576 4577Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4578secondary packet. If the packets are same, we will output primary 4579packet to outdev@var{chardevid}, else we will notify colo-frame 4580do checkpoint and send primary packet to outdev@var{chardevid}. 4581In order to improve efficiency, we need to put the task of comparison 4582in another thread. If it has the vnet_hdr_support flag, colo compare 4583will send/recv packet with vnet_hdr_len. 4584If you want to use Xen COLO, will need the notify_dev to notify Xen 4585colo-frame to do checkpoint. 4586 4587we must use it with the help of filter-mirror and filter-redirector. 4588 4589@example 4590 4591KVM COLO 4592 4593primary: 4594-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4595-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4596-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4597-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4598-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4599-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4600-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4601-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4602-object iothread,id=iothread1 4603-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4604-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4605-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4606-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4607 4608secondary: 4609-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4610-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4611-chardev socket,id=red0,host=3.3.3.3,port=9003 4612-chardev socket,id=red1,host=3.3.3.3,port=9004 4613-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4614-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4615 4616 4617Xen COLO 4618 4619primary: 4620-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4621-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4622-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4623-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4624-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4625-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4626-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4627-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4628-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4629-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4630-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4631-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4632-object iothread,id=iothread1 4633-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4634 4635secondary: 4636-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4637-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4638-chardev socket,id=red0,host=3.3.3.3,port=9003 4639-chardev socket,id=red1,host=3.3.3.3,port=9004 4640-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4641-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4642 4643@end example 4644 4645If you want to know the detail of above command line, you can read 4646the colo-compare git log. 4647 4648@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4649 4650Creates a cryptodev backend which executes crypto opreation from 4651the QEMU cipher APIS. The @var{id} parameter is 4652a unique ID that will be used to reference this cryptodev backend from 4653the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4654which specify the queue number of cryptodev backend, the default of 4655@var{queues} is 1. 4656 4657@example 4658 4659 # @value{qemu_system} \ 4660 [...] \ 4661 -object cryptodev-backend-builtin,id=cryptodev0 \ 4662 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4663 [...] 4664@end example 4665 4666@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4667 4668Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4669The @var{id} parameter is a unique ID that will be used to reference this 4670cryptodev backend from the @option{virtio-crypto} device. 4671The chardev should be a unix domain socket backed one. The vhost-user uses 4672a specifically defined protocol to pass vhost ioctl replacement messages 4673to an application on the other end of the socket. 4674The @var{queues} parameter is optional, which specify the queue number 4675of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4676 4677@example 4678 4679 # @value{qemu_system} \ 4680 [...] \ 4681 -chardev socket,id=chardev0,path=/path/to/socket \ 4682 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4683 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4684 [...] 4685@end example 4686 4687@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4688@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4689 4690Defines a secret to store a password, encryption key, or some other sensitive 4691data. The sensitive data can either be passed directly via the @var{data} 4692parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4693parameter is insecure unless the sensitive data is encrypted. 4694 4695The sensitive data can be provided in raw format (the default), or base64. 4696When encoded as JSON, the raw format only supports valid UTF-8 characters, 4697so base64 is recommended for sending binary data. QEMU will convert from 4698which ever format is provided to the format it needs internally. eg, an 4699RBD password can be provided in raw format, even though it will be base64 4700encoded when passed onto the RBD sever. 4701 4702For added protection, it is possible to encrypt the data associated with 4703a secret using the AES-256-CBC cipher. Use of encryption is indicated 4704by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4705parameter provides the ID of a previously defined secret that contains 4706the AES-256 decryption key. This key should be 32-bytes long and be 4707base64 encoded. The @var{iv} parameter provides the random initialization 4708vector used for encryption of this particular secret and should be a 4709base64 encrypted string of the 16-byte IV. 4710 4711The simplest (insecure) usage is to provide the secret inline 4712 4713@example 4714 4715 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4716 4717@end example 4718 4719The simplest secure usage is to provide the secret via a file 4720 4721 # printf "letmein" > mypasswd.txt 4722 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4723 4724For greater security, AES-256-CBC should be used. To illustrate usage, 4725consider the openssl command line tool which can encrypt the data. Note 4726that when encrypting, the plaintext must be padded to the cipher block 4727size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4728 4729First a master key needs to be created in base64 encoding: 4730 4731@example 4732 # openssl rand -base64 32 > key.b64 4733 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4734@end example 4735 4736Each secret to be encrypted needs to have a random initialization vector 4737generated. These do not need to be kept secret 4738 4739@example 4740 # openssl rand -base64 16 > iv.b64 4741 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4742@end example 4743 4744The secret to be defined can now be encrypted, in this case we're 4745telling openssl to base64 encode the result, but it could be left 4746as raw bytes if desired. 4747 4748@example 4749 # SECRET=$(printf "letmein" | 4750 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4751@end example 4752 4753When launching QEMU, create a master secret pointing to @code{key.b64} 4754and specify that to be used to decrypt the user password. Pass the 4755contents of @code{iv.b64} to the second secret 4756 4757@example 4758 # @value{qemu_system} \ 4759 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4760 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4761 data=$SECRET,iv=$(<iv.b64) 4762@end example 4763 4764@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}] 4765 4766Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4767to provide the guest memory encryption support on AMD processors. 4768 4769When memory encryption is enabled, one of the physical address bit (aka the 4770C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4771is used to provide the C-bit position. The C-bit position is Host family dependent 4772hence user must provide this value. On EPYC, the value should be 47. 4773 4774When memory encryption is enabled, we loose certain bits in physical address space. 4775The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4776physical address space. Similar to C-bit, the value is Host family dependent. 4777On EPYC, the value should be 5. 4778 4779The @option{sev-device} provides the device file to use for communicating with 4780the SEV firmware running inside AMD Secure Processor. The default device is 4781'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4782created by CCP driver. 4783 4784The @option{policy} provides the guest policy to be enforced by the SEV firmware 4785and restrict what configuration and operational commands can be performed on this 4786guest by the hypervisor. The policy should be provided by the guest owner and is 4787bound to the guest and cannot be changed throughout the lifetime of the guest. 4788The default is 0. 4789 4790If guest @option{policy} allows sharing the key with another SEV guest then 4791@option{handle} can be use to provide handle of the guest from which to share 4792the key. 4793 4794The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4795Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4796are used for establishing a cryptographic session with the guest owner to 4797negotiate keys used for attestation. The file must be encoded in base64. 4798 4799e.g to launch a SEV guest 4800@example 4801 # @value{qemu_system_x86} \ 4802 ...... 4803 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4804 -machine ...,memory-encryption=sev0 4805 ..... 4806 4807@end example 4808 4809 4810@item -object authz-simple,id=@var{id},identity=@var{string} 4811 4812Create an authorization object that will control access to network services. 4813 4814The @option{identity} parameter is identifies the user and its format 4815depends on the network service that authorization object is associated 4816with. For authorizing based on TLS x509 certificates, the identity must 4817be the x509 distinguished name. Note that care must be taken to escape 4818any commas in the distinguished name. 4819 4820An example authorization object to validate a x509 distinguished name 4821would look like: 4822@example 4823 # @value{qemu_system} \ 4824 ... 4825 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4826 ... 4827@end example 4828 4829Note the use of quotes due to the x509 distinguished name containing 4830whitespace, and escaping of ','. 4831 4832@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4833 4834Create an authorization object that will control access to network services. 4835 4836The @option{filename} parameter is the fully qualified path to a file 4837containing the access control list rules in JSON format. 4838 4839An example set of rules that match against SASL usernames might look 4840like: 4841 4842@example 4843 @{ 4844 "rules": [ 4845 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4846 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4847 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4848 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4849 ], 4850 "policy": "deny" 4851 @} 4852@end example 4853 4854When checking access the object will iterate over all the rules and 4855the first rule to match will have its @option{policy} value returned 4856as the result. If no rules match, then the default @option{policy} 4857value is returned. 4858 4859The rules can either be an exact string match, or they can use the 4860simple UNIX glob pattern matching to allow wildcards to be used. 4861 4862If @option{refresh} is set to true the file will be monitored 4863and automatically reloaded whenever its content changes. 4864 4865As with the @code{authz-simple} object, the format of the identity 4866strings being matched depends on the network service, but is usually 4867a TLS x509 distinguished name, or a SASL username. 4868 4869An example authorization object to validate a SASL username 4870would look like: 4871@example 4872 # @value{qemu_system} \ 4873 ... 4874 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4875 ... 4876@end example 4877 4878@item -object authz-pam,id=@var{id},service=@var{string} 4879 4880Create an authorization object that will control access to network services. 4881 4882The @option{service} parameter provides the name of a PAM service to use 4883for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4884exist to provide the configuration for the @code{account} subsystem. 4885 4886An example authorization object to validate a TLS x509 distinguished 4887name would look like: 4888 4889@example 4890 # @value{qemu_system} \ 4891 ... 4892 -object authz-pam,id=auth0,service=qemu-vnc 4893 ... 4894@end example 4895 4896There would then be a corresponding config file for PAM at 4897@code{/etc/pam.d/qemu-vnc} that contains: 4898 4899@example 4900account requisite pam_listfile.so item=user sense=allow \ 4901 file=/etc/qemu/vnc.allow 4902@end example 4903 4904Finally the @code{/etc/qemu/vnc.allow} file would contain 4905the list of x509 distingished names that are permitted 4906access 4907 4908@example 4909CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4910@end example 4911 4912 4913@end table 4914 4915ETEXI 4916 4917 4918HXCOMM This is the last statement. Insert new options before this line! 4919STEXI 4920@end table 4921ETEXI 4922
