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][,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\n" 146 " threads= number of threads on one CPU core\n" 147 " sockets= number of discrete sockets in the system\n", 148 QEMU_ARCH_ALL) 149STEXI 150@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 151@findex -smp 152Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 153CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 154to 4. 155For the PC target, the number of @var{cores} per socket, the number 156of @var{threads} per cores and the total number of @var{sockets} can be 157specified. Missing values will be computed. If any on the three values is 158given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 159specifies the maximum number of hotpluggable CPUs. 160ETEXI 161 162DEF("numa", HAS_ARG, QEMU_OPTION_numa, 163 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 164 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 165 "-numa dist,src=source,dst=destination,val=distance\n" 166 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n", 167 QEMU_ARCH_ALL) 168STEXI 169@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 170@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 171@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 172@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 173@findex -numa 174Define a NUMA node and assign RAM and VCPUs to it. 175Set the NUMA distance from a source node to a destination node. 176 177Legacy VCPU assignment uses @samp{cpus} option where 178@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 179@samp{cpus} option represent a contiguous range of CPU indexes 180(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 181set of VCPUs can be represented by providing multiple @samp{cpus} 182options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 183split between them. 184 185For example, the following option assigns VCPUs 0, 1, 2 and 5 to 186a NUMA node: 187@example 188-numa node,cpus=0-2,cpus=5 189@end example 190 191@samp{cpu} option is a new alternative to @samp{cpus} option 192which uses @samp{socket-id|core-id|thread-id} properties to assign 193CPU objects to a @var{node} using topology layout properties of CPU. 194The set of properties is machine specific, and depends on used 195machine type/@samp{smp} options. It could be queried with 196@samp{hotpluggable-cpus} monitor command. 197@samp{node-id} property specifies @var{node} to which CPU object 198will be assigned, it's required for @var{node} to be declared 199with @samp{node} option before it's used with @samp{cpu} option. 200 201For example: 202@example 203-M pc \ 204-smp 1,sockets=2,maxcpus=2 \ 205-numa node,nodeid=0 -numa node,nodeid=1 \ 206-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 207@end example 208 209@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 210assigns RAM from a given memory backend device to a node. If 211@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 212split equally between them. 213 214@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 215if one node uses @samp{memdev}, all of them have to use it. 216 217@var{source} and @var{destination} are NUMA node IDs. 218@var{distance} is the NUMA distance from @var{source} to @var{destination}. 219The distance from a node to itself is always 10. If any pair of nodes is 220given a distance, then all pairs must be given distances. Although, when 221distances are only given in one direction for each pair of nodes, then 222the distances in the opposite directions are assumed to be the same. If, 223however, an asymmetrical pair of distances is given for even one node 224pair, then all node pairs must be provided distance values for both 225directions, even when they are symmetrical. When a node is unreachable 226from another node, set the pair's distance to 255. 227 228Note that the -@option{numa} option doesn't allocate any of the 229specified resources, it just assigns existing resources to NUMA 230nodes. This means that one still has to use the @option{-m}, 231@option{-smp} options to allocate RAM and VCPUs respectively. 232 233ETEXI 234 235DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 236 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 237 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 238STEXI 239@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 240@findex -add-fd 241 242Add a file descriptor to an fd set. Valid options are: 243 244@table @option 245@item fd=@var{fd} 246This option defines the file descriptor of which a duplicate is added to fd set. 247The file descriptor cannot be stdin, stdout, or stderr. 248@item set=@var{set} 249This option defines the ID of the fd set to add the file descriptor to. 250@item opaque=@var{opaque} 251This option defines a free-form string that can be used to describe @var{fd}. 252@end table 253 254You can open an image using pre-opened file descriptors from an fd set: 255@example 256qemu-system-i386 257-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 258-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 259-drive file=/dev/fdset/2,index=0,media=disk 260@end example 261ETEXI 262 263DEF("set", HAS_ARG, QEMU_OPTION_set, 264 "-set group.id.arg=value\n" 265 " set <arg> parameter for item <id> of type <group>\n" 266 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 267STEXI 268@item -set @var{group}.@var{id}.@var{arg}=@var{value} 269@findex -set 270Set parameter @var{arg} for item @var{id} of type @var{group} 271ETEXI 272 273DEF("global", HAS_ARG, QEMU_OPTION_global, 274 "-global driver.property=value\n" 275 "-global driver=driver,property=property,value=value\n" 276 " set a global default for a driver property\n", 277 QEMU_ARCH_ALL) 278STEXI 279@item -global @var{driver}.@var{prop}=@var{value} 280@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 281@findex -global 282Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 283 284@example 285qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img 286@end example 287 288In particular, you can use this to set driver properties for devices which are 289created automatically by the machine model. To create a device which is not 290created automatically and set properties on it, use -@option{device}. 291 292-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 293driver=@var{driver},property=@var{prop},value=@var{value}. The 294longhand syntax works even when @var{driver} contains a dot. 295ETEXI 296 297DEF("boot", HAS_ARG, QEMU_OPTION_boot, 298 "-boot [order=drives][,once=drives][,menu=on|off]\n" 299 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 300 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 301 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 302 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 303 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 304 QEMU_ARCH_ALL) 305STEXI 306@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] 307@findex -boot 308Specify boot order @var{drives} as a string of drive letters. Valid 309drive letters depend on the target architecture. The x86 PC uses: a, b 310(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 311from network adapter 1-4), hard disk boot is the default. To apply a 312particular boot order only on the first startup, specify it via 313@option{once}. Note that the @option{order} or @option{once} parameter 314should not be used together with the @option{bootindex} property of 315devices, since the firmware implementations normally do not support both 316at the same time. 317 318Interactive boot menus/prompts can be enabled via @option{menu=on} as far 319as firmware/BIOS supports them. The default is non-interactive boot. 320 321A splash picture could be passed to bios, enabling user to show it as logo, 322when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 323supports them. Currently Seabios for X86 system support it. 324limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 325format(true color). The resolution should be supported by the SVGA mode, so 326the recommended is 320x240, 640x480, 800x640. 327 328A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 329when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 330reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 331system support it. 332 333Do strict boot via @option{strict=on} as far as firmware/BIOS 334supports it. This only effects when boot priority is changed by 335bootindex options. The default is non-strict boot. 336 337@example 338# try to boot from network first, then from hard disk 339qemu-system-i386 -boot order=nc 340# boot from CD-ROM first, switch back to default order after reboot 341qemu-system-i386 -boot once=d 342# boot with a splash picture for 5 seconds. 343qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 344@end example 345 346Note: The legacy format '-boot @var{drives}' is still supported but its 347use is discouraged as it may be removed from future versions. 348ETEXI 349 350DEF("m", HAS_ARG, QEMU_OPTION_m, 351 "-m [size=]megs[,slots=n,maxmem=size]\n" 352 " configure guest RAM\n" 353 " size: initial amount of guest memory\n" 354 " slots: number of hotplug slots (default: none)\n" 355 " maxmem: maximum amount of guest memory (default: none)\n" 356 "NOTE: Some architectures might enforce a specific granularity\n", 357 QEMU_ARCH_ALL) 358STEXI 359@item -m [size=]@var{megs}[,slots=n,maxmem=size] 360@findex -m 361Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 362Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 363megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 364could be used to set amount of hotpluggable memory slots and maximum amount of 365memory. Note that @var{maxmem} must be aligned to the page size. 366 367For example, the following command-line sets the guest startup RAM size to 3681GB, creates 3 slots to hotplug additional memory and sets the maximum 369memory the guest can reach to 4GB: 370 371@example 372qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 373@end example 374 375If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 376be enabled and the guest startup RAM will never increase. 377ETEXI 378 379DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 380 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 381STEXI 382@item -mem-path @var{path} 383@findex -mem-path 384Allocate guest RAM from a temporarily created file in @var{path}. 385ETEXI 386 387DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 388 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 389 QEMU_ARCH_ALL) 390STEXI 391@item -mem-prealloc 392@findex -mem-prealloc 393Preallocate memory when using -mem-path. 394ETEXI 395 396DEF("k", HAS_ARG, QEMU_OPTION_k, 397 "-k language use keyboard layout (for example 'fr' for French)\n", 398 QEMU_ARCH_ALL) 399STEXI 400@item -k @var{language} 401@findex -k 402Use keyboard layout @var{language} (for example @code{fr} for 403French). This option is only needed where it is not easy to get raw PC 404keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 405display). You don't normally need to use it on PC/Linux or PC/Windows 406hosts. 407 408The available layouts are: 409@example 410ar de-ch es fo fr-ca hu ja mk no pt-br sv 411da en-gb et fr fr-ch is lt nl pl ru th 412de en-us fi fr-be hr it lv nl-be pt sl tr 413@end example 414 415The default is @code{en-us}. 416ETEXI 417 418 419HXCOMM Deprecated by -audiodev 420DEF("audio-help", 0, QEMU_OPTION_audio_help, 421 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 422 QEMU_ARCH_ALL) 423STEXI 424@item -audio-help 425@findex -audio-help 426Will show the -audiodev equivalent of the currently specified 427(deprecated) environment variables. 428ETEXI 429 430DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 431 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 432 " specifies the audio backend to use\n" 433 " id= identifier of the backend\n" 434 " timer-period= timer period in microseconds\n" 435 " in|out.fixed-settings= use fixed settings for host audio\n" 436 " in|out.frequency= frequency to use with fixed settings\n" 437 " in|out.channels= number of channels to use with fixed settings\n" 438 " in|out.format= sample format to use with fixed settings\n" 439 " valid values: s8, s16, s32, u8, u16, u32\n" 440 " in|out.voices= number of voices to use\n" 441 " in|out.buffer-len= length of buffer in microseconds\n" 442 "-audiodev none,id=id,[,prop[=value][,...]]\n" 443 " dummy driver that discards all output\n" 444#ifdef CONFIG_AUDIO_ALSA 445 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 446 " in|out.dev= name of the audio device to use\n" 447 " in|out.period-len= length of period in microseconds\n" 448 " in|out.try-poll= attempt to use poll mode\n" 449 " threshold= threshold (in microseconds) when playback starts\n" 450#endif 451#ifdef CONFIG_AUDIO_COREAUDIO 452 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 453 " in|out.buffer-count= number of buffers\n" 454#endif 455#ifdef CONFIG_AUDIO_DSOUND 456 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 457 " latency= add extra latency to playback in microseconds\n" 458#endif 459#ifdef CONFIG_AUDIO_OSS 460 "-audiodev oss,id=id[,prop[=value][,...]]\n" 461 " in|out.dev= path of the audio device to use\n" 462 " in|out.buffer-count= number of buffers\n" 463 " in|out.try-poll= attempt to use poll mode\n" 464 " try-mmap= try using memory mapped access\n" 465 " exclusive= open device in exclusive mode\n" 466 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 467#endif 468#ifdef CONFIG_AUDIO_PA 469 "-audiodev pa,id=id[,prop[=value][,...]]\n" 470 " server= PulseAudio server address\n" 471 " in|out.name= source/sink device name\n" 472#endif 473#ifdef CONFIG_AUDIO_SDL 474 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 475#endif 476#ifdef CONFIG_SPICE 477 "-audiodev spice,id=id[,prop[=value][,...]]\n" 478#endif 479 "-audiodev wav,id=id[,prop[=value][,...]]\n" 480 " path= path of wav file to record\n", 481 QEMU_ARCH_ALL) 482STEXI 483@item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]] 484@findex -audiodev 485Adds a new audio backend @var{driver} identified by @var{id}. There are 486global and driver specific properties. Some values can be set 487differently for input and output, they're marked with @code{in|out.}. 488You can set the input's property with @code{in.@var{prop}} and the 489output's property with @code{out.@var{prop}}. For example: 490@example 491-audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 492-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 493@end example 494 495Valid global options are: 496 497@table @option 498@item id=@var{identifier} 499Identifies the audio backend. 500 501@item timer-period=@var{period} 502Sets the timer @var{period} used by the audio subsystem in microseconds. 503Default is 10000 (10 ms). 504 505@item in|out.fixed-settings=on|off 506Use fixed settings for host audio. When off, it will change based on 507how the guest opens the sound card. In this case you must not specify 508@var{frequency}, @var{channels} or @var{format}. Default is on. 509 510@item in|out.frequency=@var{frequency} 511Specify the @var{frequency} to use when using @var{fixed-settings}. 512Default is 44100Hz. 513 514@item in|out.channels=@var{channels} 515Specify the number of @var{channels} to use when using 516@var{fixed-settings}. Default is 2 (stereo). 517 518@item in|out.format=@var{format} 519Specify the sample @var{format} to use when using @var{fixed-settings}. 520Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8}, 521@code{u16}, @code{u32}. Default is @code{s16}. 522 523@item in|out.voices=@var{voices} 524Specify the number of @var{voices} to use. Default is 1. 525 526@item in|out.buffer=@var{usecs} 527Sets the size of the buffer in microseconds. 528 529@end table 530 531@item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]] 532Creates a dummy backend that discards all outputs. This backend has no 533backend specific properties. 534 535@item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 536Creates backend using the ALSA. This backend is only available on 537Linux. 538 539ALSA specific options are: 540 541@table @option 542 543@item in|out.dev=@var{device} 544Specify the ALSA @var{device} to use for input and/or output. Default 545is @code{default}. 546 547@item in|out.period-len=@var{usecs} 548Sets the period length in microseconds. 549 550@item in|out.try-poll=on|off 551Attempt to use poll mode with the device. Default is on. 552 553@item threshold=@var{threshold} 554Threshold (in microseconds) when playback starts. Default is 0. 555 556@end table 557 558@item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]] 559Creates a backend using Apple's Core Audio. This backend is only 560available on Mac OS and only supports playback. 561 562Core Audio specific options are: 563 564@table @option 565 566@item in|out.buffer-count=@var{count} 567Sets the @var{count} of the buffers. 568 569@end table 570 571@item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]] 572Creates a backend using Microsoft's DirectSound. This backend is only 573available on Windows and only supports playback. 574 575DirectSound specific options are: 576 577@table @option 578 579@item latency=@var{usecs} 580Add extra @var{usecs} microseconds latency to playback. Default is 58110000 (10 ms). 582 583@end table 584 585@item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]] 586Creates a backend using OSS. This backend is available on most 587Unix-like systems. 588 589OSS specific options are: 590 591@table @option 592 593@item in|out.dev=@var{device} 594Specify the file name of the OSS @var{device} to use. Default is 595@code{/dev/dsp}. 596 597@item in|out.buffer-count=@var{count} 598Sets the @var{count} of the buffers. 599 600@item in|out.try-poll=on|of 601Attempt to use poll mode with the device. Default is on. 602 603@item try-mmap=on|off 604Try using memory mapped device access. Default is off. 605 606@item exclusive=on|off 607Open the device in exclusive mode (vmix won't work in this case). 608Default is off. 609 610@item dsp-policy=@var{policy} 611Sets the timing policy (between 0 and 10, where smaller number means 612smaller latency but higher CPU usage). Use -1 to use buffer sizes 613specified by @code{buffer} and @code{buffer-count}. This option is 614ignored if you do not have OSS 4. Default is 5. 615 616@end table 617 618@item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 619Creates a backend using PulseAudio. This backend is available on most 620systems. 621 622PulseAudio specific options are: 623 624@table @option 625 626@item server=@var{server} 627Sets the PulseAudio @var{server} to connect to. 628 629@item in|out.name=@var{sink} 630Use the specified source/sink for recording/playback. 631 632@end table 633 634@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]] 635Creates a backend using SDL. This backend is available on most systems, 636but you should use your platform's native backend if possible. This 637backend has no backend specific properties. 638 639@item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]] 640Creates a backend that sends audio through SPICE. This backend requires 641@code{-spice} and automatically selected in that case, so usually you 642can ignore this option. This backend has no backend specific 643properties. 644 645@item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]] 646Creates a backend that writes audio to a WAV file. 647 648Backend specific options are: 649 650@table @option 651 652@item path=@var{path} 653Write recorded audio into the specified file. Default is 654@code{qemu.wav}. 655 656@end table 657ETEXI 658 659DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 660 "-soundhw c1,... enable audio support\n" 661 " and only specified sound cards (comma separated list)\n" 662 " use '-soundhw help' to get the list of supported cards\n" 663 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 664STEXI 665@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 666@findex -soundhw 667Enable audio and selected sound hardware. Use 'help' to print all 668available sound hardware. 669 670@example 671qemu-system-i386 -soundhw sb16,adlib disk.img 672qemu-system-i386 -soundhw es1370 disk.img 673qemu-system-i386 -soundhw ac97 disk.img 674qemu-system-i386 -soundhw hda disk.img 675qemu-system-i386 -soundhw all disk.img 676qemu-system-i386 -soundhw help 677@end example 678 679Note that Linux's i810_audio OSS kernel (for AC97) module might 680require manually specifying clocking. 681 682@example 683modprobe i810_audio clocking=48000 684@end example 685ETEXI 686 687DEF("device", HAS_ARG, QEMU_OPTION_device, 688 "-device driver[,prop[=value][,...]]\n" 689 " add device (based on driver)\n" 690 " prop=value,... sets driver properties\n" 691 " use '-device help' to print all possible drivers\n" 692 " use '-device driver,help' to print all possible properties\n", 693 QEMU_ARCH_ALL) 694STEXI 695@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 696@findex -device 697Add device @var{driver}. @var{prop}=@var{value} sets driver 698properties. Valid properties depend on the driver. To get help on 699possible drivers and properties, use @code{-device help} and 700@code{-device @var{driver},help}. 701 702Some drivers are: 703@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}] 704 705Add an IPMI BMC. This is a simulation of a hardware management 706interface processor that normally sits on a system. It provides 707a watchdog and the ability to reset and power control the system. 708You need to connect this to an IPMI interface to make it useful 709 710The IPMI slave address to use for the BMC. The default is 0x20. 711This address is the BMC's address on the I2C network of management 712controllers. If you don't know what this means, it is safe to ignore 713it. 714 715@table @option 716@item bmc=@var{id} 717The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 718@item slave_addr=@var{val} 719Define slave address to use for the BMC. The default is 0x20. 720@item sdrfile=@var{file} 721file containing raw Sensor Data Records (SDR) data. The default is none. 722@item fruareasize=@var{val} 723size of a Field Replaceable Unit (FRU) area. The default is 1024. 724@item frudatafile=@var{file} 725file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 726@end table 727 728@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 729 730Add a connection to an external IPMI BMC simulator. Instead of 731locally emulating the BMC like the above item, instead connect 732to an external entity that provides the IPMI services. 733 734A connection is made to an external BMC simulator. If you do this, it 735is strongly recommended that you use the "reconnect=" chardev option 736to reconnect to the simulator if the connection is lost. Note that if 737this is not used carefully, it can be a security issue, as the 738interface has the ability to send resets, NMIs, and power off the VM. 739It's best if QEMU makes a connection to an external simulator running 740on a secure port on localhost, so neither the simulator nor QEMU is 741exposed to any outside network. 742 743See the "lanserv/README.vm" file in the OpenIPMI library for more 744details on the external interface. 745 746@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 747 748Add a KCS IPMI interafce on the ISA bus. This also adds a 749corresponding ACPI and SMBIOS entries, if appropriate. 750 751@table @option 752@item bmc=@var{id} 753The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 754@item ioport=@var{val} 755Define the I/O address of the interface. The default is 0xca0 for KCS. 756@item irq=@var{val} 757Define the interrupt to use. The default is 5. To disable interrupts, 758set this to 0. 759@end table 760 761@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 762 763Like the KCS interface, but defines a BT interface. The default port is 7640xe4 and the default interrupt is 5. 765 766ETEXI 767 768DEF("name", HAS_ARG, QEMU_OPTION_name, 769 "-name string1[,process=string2][,debug-threads=on|off]\n" 770 " set the name of the guest\n" 771 " string1 sets the window title and string2 the process name\n" 772 " When debug-threads is enabled, individual threads are given a separate name\n" 773 " NOTE: The thread names are for debugging and not a stable API.\n", 774 QEMU_ARCH_ALL) 775STEXI 776@item -name @var{name} 777@findex -name 778Sets the @var{name} of the guest. 779This name will be displayed in the SDL window caption. 780The @var{name} will also be used for the VNC server. 781Also optionally set the top visible process name in Linux. 782Naming of individual threads can also be enabled on Linux to aid debugging. 783ETEXI 784 785DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 786 "-uuid %08x-%04x-%04x-%04x-%012x\n" 787 " specify machine UUID\n", QEMU_ARCH_ALL) 788STEXI 789@item -uuid @var{uuid} 790@findex -uuid 791Set system UUID. 792ETEXI 793 794STEXI 795@end table 796ETEXI 797DEFHEADING() 798 799DEFHEADING(Block device options:) 800STEXI 801@table @option 802ETEXI 803 804DEF("fda", HAS_ARG, QEMU_OPTION_fda, 805 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 806DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 807STEXI 808@item -fda @var{file} 809@itemx -fdb @var{file} 810@findex -fda 811@findex -fdb 812Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 813ETEXI 814 815DEF("hda", HAS_ARG, QEMU_OPTION_hda, 816 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 817DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 818DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 819 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 820DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 821STEXI 822@item -hda @var{file} 823@itemx -hdb @var{file} 824@itemx -hdc @var{file} 825@itemx -hdd @var{file} 826@findex -hda 827@findex -hdb 828@findex -hdc 829@findex -hdd 830Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 831ETEXI 832 833DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 834 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 835 QEMU_ARCH_ALL) 836STEXI 837@item -cdrom @var{file} 838@findex -cdrom 839Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 840@option{-cdrom} at the same time). You can use the host CD-ROM by 841using @file{/dev/cdrom} as filename (@pxref{host_drives}). 842ETEXI 843 844DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 845 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 846 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 847 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n" 848 " [,driver specific parameters...]\n" 849 " configure a block backend\n", QEMU_ARCH_ALL) 850STEXI 851@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 852@findex -blockdev 853 854Define a new block driver node. Some of the options apply to all block drivers, 855other options are only accepted for a specific block driver. See below for a 856list of generic options and options for the most common block drivers. 857 858Options that expect a reference to another node (e.g. @code{file}) can be 859given in two ways. Either you specify the node name of an already existing node 860(file=@var{node-name}), or you define a new node inline, adding options 861for the referenced node after a dot (file.filename=@var{path},file.aio=native). 862 863A block driver node created with @option{-blockdev} can be used for a guest 864device by specifying its node name for the @code{drive} property in a 865@option{-device} argument that defines a block device. 866 867@table @option 868@item Valid options for any block driver node: 869 870@table @code 871@item driver 872Specifies the block driver to use for the given node. 873@item node-name 874This defines the name of the block driver node by which it will be referenced 875later. The name must be unique, i.e. it must not match the name of a different 876block driver node, or (if you use @option{-drive} as well) the ID of a drive. 877 878If no node name is specified, it is automatically generated. The generated node 879name is not intended to be predictable and changes between QEMU invocations. 880For the top level, an explicit node name must be specified. 881@item read-only 882Open the node read-only. Guest write attempts will fail. 883@item cache.direct 884The host page cache can be avoided with @option{cache.direct=on}. This will 885attempt to do disk IO directly to the guest's memory. QEMU may still perform an 886internal copy of the data. 887@item cache.no-flush 888In case you don't care about data integrity over host failures, you can use 889@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 890any data to the disk but can instead keep things in cache. If anything goes 891wrong, like your host losing power, the disk storage getting disconnected 892accidentally, etc. your image will most probably be rendered unusable. 893@item discard=@var{discard} 894@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 895whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 896ignored or passed to the filesystem. Some machine types may not support 897discard requests. 898@item detect-zeroes=@var{detect-zeroes} 899@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 900conversion of plain zero writes by the OS to driver specific optimized 901zero write commands. You may even choose "unmap" if @var{discard} is set 902to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 903@end table 904 905@item Driver-specific options for @code{file} 906 907This is the protocol-level block driver for accessing regular files. 908 909@table @code 910@item filename 911The path to the image file in the local filesystem 912@item aio 913Specifies the AIO backend (threads/native, default: threads) 914@item locking 915Specifies whether the image file is protected with Linux OFD / POSIX locks. The 916default is to use the Linux Open File Descriptor API if available, otherwise no 917lock is applied. (auto/on/off, default: auto) 918@end table 919Example: 920@example 921-blockdev driver=file,node-name=disk,filename=disk.img 922@end example 923 924@item Driver-specific options for @code{raw} 925 926This is the image format block driver for raw images. It is usually 927stacked on top of a protocol level block driver such as @code{file}. 928 929@table @code 930@item file 931Reference to or definition of the data source block driver node 932(e.g. a @code{file} driver node) 933@end table 934Example 1: 935@example 936-blockdev driver=file,node-name=disk_file,filename=disk.img 937-blockdev driver=raw,node-name=disk,file=disk_file 938@end example 939Example 2: 940@example 941-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 942@end example 943 944@item Driver-specific options for @code{qcow2} 945 946This is the image format block driver for qcow2 images. It is usually 947stacked on top of a protocol level block driver such as @code{file}. 948 949@table @code 950@item file 951Reference to or definition of the data source block driver node 952(e.g. a @code{file} driver node) 953 954@item backing 955Reference to or definition of the backing file block device (default is taken 956from the image file). It is allowed to pass @code{null} here in order to disable 957the default backing file. 958 959@item lazy-refcounts 960Whether to enable the lazy refcounts feature (on/off; default is taken from the 961image file) 962 963@item cache-size 964The maximum total size of the L2 table and refcount block caches in bytes 965(default: the sum of l2-cache-size and refcount-cache-size) 966 967@item l2-cache-size 968The maximum size of the L2 table cache in bytes 969(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 970non-Linux platforms; otherwise, as large as possible within the cache-size, 971while permitting the requested or the minimal refcount cache size) 972 973@item refcount-cache-size 974The maximum size of the refcount block cache in bytes 975(default: 4 times the cluster size; or if cache-size is specified, the part of 976it which is not used for the L2 cache) 977 978@item cache-clean-interval 979Clean unused entries in the L2 and refcount caches. The interval is in seconds. 980The default value is 600 on supporting platforms, and 0 on other platforms. 981Setting it to 0 disables this feature. 982 983@item pass-discard-request 984Whether discard requests to the qcow2 device should be forwarded to the data 985source (on/off; default: on if discard=unmap is specified, off otherwise) 986 987@item pass-discard-snapshot 988Whether discard requests for the data source should be issued when a snapshot 989operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 990default: on) 991 992@item pass-discard-other 993Whether discard requests for the data source should be issued on other 994occasions where a cluster gets freed (on/off; default: off) 995 996@item overlap-check 997Which overlap checks to perform for writes to the image 998(none/constant/cached/all; default: cached). For details or finer 999granularity control refer to the QAPI documentation of @code{blockdev-add}. 1000@end table 1001 1002Example 1: 1003@example 1004-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1005-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1006@end example 1007Example 2: 1008@example 1009-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1010@end example 1011 1012@item Driver-specific options for other drivers 1013Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1014 1015@end table 1016 1017ETEXI 1018 1019DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1020 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1021 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1022 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1023 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1024 " [,readonly=on|off][,copy-on-read=on|off]\n" 1025 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1026 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1027 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1028 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1029 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1030 " [[,iops_size=is]]\n" 1031 " [[,group=g]]\n" 1032 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1033STEXI 1034@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1035@findex -drive 1036 1037Define a new drive. This includes creating a block driver node (the backend) as 1038well as a guest device, and is mostly a shortcut for defining the corresponding 1039@option{-blockdev} and @option{-device} options. 1040 1041@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1042addition, it knows the following options: 1043 1044@table @option 1045@item file=@var{file} 1046This option defines which disk image (@pxref{disk_images}) to use with 1047this drive. If the filename contains comma, you must double it 1048(for instance, "file=my,,file" to use file "my,file"). 1049 1050Special files such as iSCSI devices can be specified using protocol 1051specific URLs. See the section for "Device URL Syntax" for more information. 1052@item if=@var{interface} 1053This option defines on which type on interface the drive is connected. 1054Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1055@item bus=@var{bus},unit=@var{unit} 1056These options define where is connected the drive by defining the bus number and 1057the unit id. 1058@item index=@var{index} 1059This option defines where is connected the drive by using an index in the list 1060of available connectors of a given interface type. 1061@item media=@var{media} 1062This option defines the type of the media: disk or cdrom. 1063@item snapshot=@var{snapshot} 1064@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1065(see @option{-snapshot}). 1066@item cache=@var{cache} 1067@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1068and controls how the host cache is used to access block data. This is a 1069shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1070options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1071which provides a default for the @option{write-cache} option of block guest 1072devices (as in @option{-device}). The modes correspond to the following 1073settings: 1074 1075@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1076@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1077@c and the HTML output. 1078@example 1079@ │ cache.writeback cache.direct cache.no-flush 1080─────────────┼───────────────────────────────────────────────── 1081writeback │ on off off 1082none │ on on off 1083writethrough │ off off off 1084directsync │ off on off 1085unsafe │ on off on 1086@end example 1087 1088The default mode is @option{cache=writeback}. 1089 1090@item aio=@var{aio} 1091@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1092@item format=@var{format} 1093Specify which disk @var{format} will be used rather than detecting 1094the format. Can be used to specify format=raw to avoid interpreting 1095an untrusted format header. 1096@item werror=@var{action},rerror=@var{action} 1097Specify which @var{action} to take on write and read errors. Valid actions are: 1098"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1099"report" (report the error to the guest), "enospc" (pause QEMU only if the 1100host disk is full; report the error to the guest otherwise). 1101The default setting is @option{werror=enospc} and @option{rerror=report}. 1102@item copy-on-read=@var{copy-on-read} 1103@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1104file sectors into the image file. 1105@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1106Specify bandwidth throttling limits in bytes per second, either for all request 1107types or for reads or writes only. Small values can lead to timeouts or hangs 1108inside the guest. A safe minimum for disks is 2 MB/s. 1109@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1110Specify bursts in bytes per second, either for all request types or for reads 1111or writes only. Bursts allow the guest I/O to spike above the limit 1112temporarily. 1113@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1114Specify request rate limits in requests per second, either for all request 1115types or for reads or writes only. 1116@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1117Specify bursts in requests per second, either for all request types or for reads 1118or writes only. Bursts allow the guest I/O to spike above the limit 1119temporarily. 1120@item iops_size=@var{is} 1121Let every @var{is} bytes of a request count as a new request for iops 1122throttling purposes. Use this option to prevent guests from circumventing iops 1123limits by sending fewer but larger requests. 1124@item group=@var{g} 1125Join a throttling quota group with given name @var{g}. All drives that are 1126members of the same group are accounted for together. Use this option to 1127prevent guests from circumventing throttling limits by using many small disks 1128instead of a single larger disk. 1129@end table 1130 1131By default, the @option{cache.writeback=on} mode is used. It will report data 1132writes as completed as soon as the data is present in the host page cache. 1133This is safe as long as your guest OS makes sure to correctly flush disk caches 1134where needed. If your guest OS does not handle volatile disk write caches 1135correctly and your host crashes or loses power, then the guest may experience 1136data corruption. 1137 1138For such guests, you should consider using @option{cache.writeback=off}. This 1139means that the host page cache will be used to read and write data, but write 1140notification will be sent to the guest only after QEMU has made sure to flush 1141each write to the disk. Be aware that this has a major impact on performance. 1142 1143When using the @option{-snapshot} option, unsafe caching is always used. 1144 1145Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1146useful when the backing file is over a slow network. By default copy-on-read 1147is off. 1148 1149Instead of @option{-cdrom} you can use: 1150@example 1151qemu-system-i386 -drive file=file,index=2,media=cdrom 1152@end example 1153 1154Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1155use: 1156@example 1157qemu-system-i386 -drive file=file,index=0,media=disk 1158qemu-system-i386 -drive file=file,index=1,media=disk 1159qemu-system-i386 -drive file=file,index=2,media=disk 1160qemu-system-i386 -drive file=file,index=3,media=disk 1161@end example 1162 1163You can open an image using pre-opened file descriptors from an fd set: 1164@example 1165qemu-system-i386 1166-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 1167-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 1168-drive file=/dev/fdset/2,index=0,media=disk 1169@end example 1170 1171You can connect a CDROM to the slave of ide0: 1172@example 1173qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 1174@end example 1175 1176If you don't specify the "file=" argument, you define an empty drive: 1177@example 1178qemu-system-i386 -drive if=ide,index=1,media=cdrom 1179@end example 1180 1181Instead of @option{-fda}, @option{-fdb}, you can use: 1182@example 1183qemu-system-i386 -drive file=file,index=0,if=floppy 1184qemu-system-i386 -drive file=file,index=1,if=floppy 1185@end example 1186 1187By default, @var{interface} is "ide" and @var{index} is automatically 1188incremented: 1189@example 1190qemu-system-i386 -drive file=a -drive file=b" 1191@end example 1192is interpreted like: 1193@example 1194qemu-system-i386 -hda a -hdb b 1195@end example 1196ETEXI 1197 1198DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1199 "-mtdblock file use 'file' as on-board Flash memory image\n", 1200 QEMU_ARCH_ALL) 1201STEXI 1202@item -mtdblock @var{file} 1203@findex -mtdblock 1204Use @var{file} as on-board Flash memory image. 1205ETEXI 1206 1207DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1208 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1209STEXI 1210@item -sd @var{file} 1211@findex -sd 1212Use @var{file} as SecureDigital card image. 1213ETEXI 1214 1215DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1216 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1217STEXI 1218@item -pflash @var{file} 1219@findex -pflash 1220Use @var{file} as a parallel flash image. 1221ETEXI 1222 1223DEF("snapshot", 0, QEMU_OPTION_snapshot, 1224 "-snapshot write to temporary files instead of disk image files\n", 1225 QEMU_ARCH_ALL) 1226STEXI 1227@item -snapshot 1228@findex -snapshot 1229Write to temporary files instead of disk image files. In this case, 1230the raw disk image you use is not written back. You can however force 1231the write back by pressing @key{C-a s} (@pxref{disk_images}). 1232ETEXI 1233 1234DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1235 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1236 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1237 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1238 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1239 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1240 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1241 " [[,throttling.iops-size=is]]\n" 1242 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1243 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1244 "-fsdev synth,id=id\n", 1245 QEMU_ARCH_ALL) 1246 1247STEXI 1248 1249@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}[,...]]] 1250@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1251@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1252@itemx -fsdev synth,id=@var{id}[,readonly] 1253@findex -fsdev 1254Define a new file system device. Valid options are: 1255@table @option 1256@item local 1257Accesses to the filesystem are done by QEMU. 1258@item proxy 1259Accesses to the filesystem are done by virtfs-proxy-helper(1). 1260@item synth 1261Synthetic filesystem, only used by QTests. 1262@item id=@var{id} 1263Specifies identifier for this device. 1264@item path=@var{path} 1265Specifies the export path for the file system device. Files under 1266this path will be available to the 9p client on the guest. 1267@item security_model=@var{security_model} 1268Specifies the security model to be used for this export path. 1269Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1270In "passthrough" security model, files are stored using the same 1271credentials as they are created on the guest. This requires QEMU 1272to run as root. In "mapped-xattr" security model, some of the file 1273attributes like uid, gid, mode bits and link target are stored as 1274file attributes. For "mapped-file" these attributes are stored in the 1275hidden .virtfs_metadata directory. Directories exported by this security model cannot 1276interact with other unix tools. "none" security model is same as 1277passthrough except the sever won't report failures if it fails to 1278set file attributes like ownership. Security model is mandatory 1279only for local fsdriver. Other fsdrivers (like proxy) don't take 1280security model as a parameter. 1281@item writeout=@var{writeout} 1282This is an optional argument. The only supported value is "immediate". 1283This means that host page cache will be used to read and write data but 1284write notification will be sent to the guest only when the data has been 1285reported as written by the storage subsystem. 1286@item readonly 1287Enables exporting 9p share as a readonly mount for guests. By default 1288read-write access is given. 1289@item socket=@var{socket} 1290Enables proxy filesystem driver to use passed socket file for communicating 1291with virtfs-proxy-helper(1). 1292@item sock_fd=@var{sock_fd} 1293Enables proxy filesystem driver to use passed socket descriptor for 1294communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1295will create socketpair and pass one of the fds as sock_fd. 1296@item fmode=@var{fmode} 1297Specifies the default mode for newly created files on the host. Works only 1298with security models "mapped-xattr" and "mapped-file". 1299@item dmode=@var{dmode} 1300Specifies the default mode for newly created directories on the host. Works 1301only with security models "mapped-xattr" and "mapped-file". 1302@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1303Specify bandwidth throttling limits in bytes per second, either for all request 1304types or for reads or writes only. 1305@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1306Specify bursts in bytes per second, either for all request types or for reads 1307or writes only. Bursts allow the guest I/O to spike above the limit 1308temporarily. 1309@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1310Specify request rate limits in requests per second, either for all request 1311types or for reads or writes only. 1312@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1313Specify bursts in requests per second, either for all request types or for reads 1314or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1315@item throttling.iops-size=@var{is} 1316Let every @var{is} bytes of a request count as a new request for iops 1317throttling purposes. 1318@end table 1319 1320-fsdev option is used along with -device driver "virtio-9p-...". 1321@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1322Options for virtio-9p-... driver are: 1323@table @option 1324@item @var{type} 1325Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1326depending on the machine type. 1327@item fsdev=@var{id} 1328Specifies the id value specified along with -fsdev option. 1329@item mount_tag=@var{mount_tag} 1330Specifies the tag name to be used by the guest to mount this export point. 1331@end table 1332 1333ETEXI 1334 1335DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1336 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1337 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1338 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1339 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1340 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1341 QEMU_ARCH_ALL) 1342 1343STEXI 1344 1345@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}] 1346@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1347@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1348@itemx -virtfs synth,mount_tag=@var{mount_tag} 1349@findex -virtfs 1350 1351Define 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: 1352@table @option 1353@item local 1354Accesses to the filesystem are done by QEMU. 1355@item proxy 1356Accesses to the filesystem are done by virtfs-proxy-helper(1). 1357@item synth 1358Synthetic filesystem, only used by QTests. 1359@item id=@var{id} 1360Specifies identifier for the filesystem device 1361@item path=@var{path} 1362Specifies the export path for the file system device. Files under 1363this path will be available to the 9p client on the guest. 1364@item security_model=@var{security_model} 1365Specifies the security model to be used for this export path. 1366Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1367In "passthrough" security model, files are stored using the same 1368credentials as they are created on the guest. This requires QEMU 1369to run as root. In "mapped-xattr" security model, some of the file 1370attributes like uid, gid, mode bits and link target are stored as 1371file attributes. For "mapped-file" these attributes are stored in the 1372hidden .virtfs_metadata directory. Directories exported by this security model cannot 1373interact with other unix tools. "none" security model is same as 1374passthrough except the sever won't report failures if it fails to 1375set file attributes like ownership. Security model is mandatory only 1376for local fsdriver. Other fsdrivers (like proxy) don't take security 1377model as a parameter. 1378@item writeout=@var{writeout} 1379This is an optional argument. The only supported value is "immediate". 1380This means that host page cache will be used to read and write data but 1381write notification will be sent to the guest only when the data has been 1382reported as written by the storage subsystem. 1383@item readonly 1384Enables exporting 9p share as a readonly mount for guests. By default 1385read-write access is given. 1386@item socket=@var{socket} 1387Enables proxy filesystem driver to use passed socket file for 1388communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1389will create socketpair and pass one of the fds as sock_fd. 1390@item sock_fd 1391Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1392descriptor for interfacing with virtfs-proxy-helper(1). 1393@item fmode=@var{fmode} 1394Specifies the default mode for newly created files on the host. Works only 1395with security models "mapped-xattr" and "mapped-file". 1396@item dmode=@var{dmode} 1397Specifies the default mode for newly created directories on the host. Works 1398only with security models "mapped-xattr" and "mapped-file". 1399@item mount_tag=@var{mount_tag} 1400Specifies the tag name to be used by the guest to mount this export point. 1401@end table 1402ETEXI 1403 1404DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1405 "-virtfs_synth Create synthetic file system image\n", 1406 QEMU_ARCH_ALL) 1407STEXI 1408@item -virtfs_synth 1409@findex -virtfs_synth 1410Create synthetic file system image. Note that this option is now deprecated. 1411Please use @code{-fsdev synth} and @code{-device virtio-9p-...} instead. 1412ETEXI 1413 1414DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1415 "-iscsi [user=user][,password=password]\n" 1416 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1417 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1418 " [,timeout=timeout]\n" 1419 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1420 1421STEXI 1422@item -iscsi 1423@findex -iscsi 1424Configure iSCSI session parameters. 1425ETEXI 1426 1427STEXI 1428@end table 1429ETEXI 1430DEFHEADING() 1431 1432DEFHEADING(USB options:) 1433STEXI 1434@table @option 1435ETEXI 1436 1437DEF("usb", 0, QEMU_OPTION_usb, 1438 "-usb enable the USB driver (if it is not used by default yet)\n", 1439 QEMU_ARCH_ALL) 1440STEXI 1441@item -usb 1442@findex -usb 1443Enable the USB driver (if it is not used by default yet). 1444ETEXI 1445 1446DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1447 "-usbdevice name add the host or guest USB device 'name'\n", 1448 QEMU_ARCH_ALL) 1449STEXI 1450 1451@item -usbdevice @var{devname} 1452@findex -usbdevice 1453Add the USB device @var{devname}. Note that this option is deprecated, 1454please use @code{-device usb-...} instead. @xref{usb_devices}. 1455 1456@table @option 1457 1458@item mouse 1459Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1460 1461@item tablet 1462Pointer device that uses absolute coordinates (like a touchscreen). This 1463means QEMU is able to report the mouse position without having to grab the 1464mouse. Also overrides the PS/2 mouse emulation when activated. 1465 1466@item braille 1467Braille device. This will use BrlAPI to display the braille output on a real 1468or fake device. 1469 1470@end table 1471ETEXI 1472 1473STEXI 1474@end table 1475ETEXI 1476DEFHEADING() 1477 1478DEFHEADING(Display options:) 1479STEXI 1480@table @option 1481ETEXI 1482 1483DEF("display", HAS_ARG, QEMU_OPTION_display, 1484 "-display spice-app[,gl=on|off]\n" 1485 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1486 " [,window_close=on|off][,gl=on|core|es|off]\n" 1487 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1488 "-display vnc=<display>[,<optargs>]\n" 1489 "-display curses[,charset=<encoding>]\n" 1490 "-display none\n" 1491 "-display egl-headless[,rendernode=<file>]" 1492 " select display type\n" 1493 "The default display is equivalent to\n" 1494#if defined(CONFIG_GTK) 1495 "\t\"-display gtk\"\n" 1496#elif defined(CONFIG_SDL) 1497 "\t\"-display sdl\"\n" 1498#elif defined(CONFIG_COCOA) 1499 "\t\"-display cocoa\"\n" 1500#elif defined(CONFIG_VNC) 1501 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1502#else 1503 "\t\"-display none\"\n" 1504#endif 1505 , QEMU_ARCH_ALL) 1506STEXI 1507@item -display @var{type} 1508@findex -display 1509Select type of display to use. This option is a replacement for the 1510old style -sdl/-curses/... options. Valid values for @var{type} are 1511@table @option 1512@item sdl 1513Display video output via SDL (usually in a separate graphics 1514window; see the SDL documentation for other possibilities). 1515@item curses 1516Display video output via curses. For graphics device models which 1517support a text mode, QEMU can display this output using a 1518curses/ncurses interface. Nothing is displayed when the graphics 1519device is in graphical mode or if the graphics device does not support 1520a text mode. Generally only the VGA device models support text mode. 1521The font charset used by the guest can be specified with the 1522@code{charset} option, for example @code{charset=CP850} for IBM CP850 1523encoding. The default is @code{CP437}. 1524@item none 1525Do not display video output. The guest will still see an emulated 1526graphics card, but its output will not be displayed to the QEMU 1527user. This option differs from the -nographic option in that it 1528only affects what is done with video output; -nographic also changes 1529the destination of the serial and parallel port data. 1530@item gtk 1531Display video output in a GTK window. This interface provides drop-down 1532menus and other UI elements to configure and control the VM during 1533runtime. 1534@item vnc 1535Start a VNC server on display <arg> 1536@item egl-headless 1537Offload all OpenGL operations to a local DRI device. For any graphical display, 1538this display needs to be paired with either VNC or SPICE displays. 1539@item spice-app 1540Start QEMU as a Spice server and launch the default Spice client 1541application. The Spice server will redirect the serial consoles and 1542QEMU monitors. (Since 4.0) 1543@end table 1544ETEXI 1545 1546DEF("nographic", 0, QEMU_OPTION_nographic, 1547 "-nographic disable graphical output and redirect serial I/Os to console\n", 1548 QEMU_ARCH_ALL) 1549STEXI 1550@item -nographic 1551@findex -nographic 1552Normally, if QEMU is compiled with graphical window support, it displays 1553output such as guest graphics, guest console, and the QEMU monitor in a 1554window. With this option, you can totally disable graphical output so 1555that QEMU is a simple command line application. The emulated serial port 1556is redirected on the console and muxed with the monitor (unless 1557redirected elsewhere explicitly). Therefore, you can still use QEMU to 1558debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1559switching between the console and monitor. 1560ETEXI 1561 1562DEF("curses", 0, QEMU_OPTION_curses, 1563 "-curses shorthand for -display curses\n", 1564 QEMU_ARCH_ALL) 1565STEXI 1566@item -curses 1567@findex -curses 1568Normally, if QEMU is compiled with graphical window support, it displays 1569output such as guest graphics, guest console, and the QEMU monitor in a 1570window. With this option, QEMU can display the VGA output when in text 1571mode using a curses/ncurses interface. Nothing is displayed in graphical 1572mode. 1573ETEXI 1574 1575DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1576 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1577 QEMU_ARCH_ALL) 1578STEXI 1579@item -alt-grab 1580@findex -alt-grab 1581Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1582affects the special keys (for fullscreen, monitor-mode switching, etc). 1583ETEXI 1584 1585DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1586 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1587 QEMU_ARCH_ALL) 1588STEXI 1589@item -ctrl-grab 1590@findex -ctrl-grab 1591Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1592affects the special keys (for fullscreen, monitor-mode switching, etc). 1593ETEXI 1594 1595DEF("no-quit", 0, QEMU_OPTION_no_quit, 1596 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1597STEXI 1598@item -no-quit 1599@findex -no-quit 1600Disable SDL window close capability. 1601ETEXI 1602 1603DEF("sdl", 0, QEMU_OPTION_sdl, 1604 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1605STEXI 1606@item -sdl 1607@findex -sdl 1608Enable SDL. 1609ETEXI 1610 1611DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1612 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1613 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1614 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1615 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1616 " [,tls-ciphers=<list>]\n" 1617 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1618 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1619 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1620 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1621 " [,jpeg-wan-compression=[auto|never|always]]\n" 1622 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1623 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1624 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1625 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1626 " [,gl=[on|off]][,rendernode=<file>]\n" 1627 " enable spice\n" 1628 " at least one of {port, tls-port} is mandatory\n", 1629 QEMU_ARCH_ALL) 1630STEXI 1631@item -spice @var{option}[,@var{option}[,...]] 1632@findex -spice 1633Enable the spice remote desktop protocol. Valid options are 1634 1635@table @option 1636 1637@item port=<nr> 1638Set the TCP port spice is listening on for plaintext channels. 1639 1640@item addr=<addr> 1641Set the IP address spice is listening on. Default is any address. 1642 1643@item ipv4 1644@itemx ipv6 1645@itemx unix 1646Force using the specified IP version. 1647 1648@item password=<secret> 1649Set the password you need to authenticate. 1650 1651@item sasl 1652Require that the client use SASL to authenticate with the spice. 1653The exact choice of authentication method used is controlled from the 1654system / user's SASL configuration file for the 'qemu' service. This 1655is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1656unprivileged user, an environment variable SASL_CONF_PATH can be used 1657to make it search alternate locations for the service config. 1658While some SASL auth methods can also provide data encryption (eg GSSAPI), 1659it is recommended that SASL always be combined with the 'tls' and 1660'x509' settings to enable use of SSL and server certificates. This 1661ensures a data encryption preventing compromise of authentication 1662credentials. 1663 1664@item disable-ticketing 1665Allow client connects without authentication. 1666 1667@item disable-copy-paste 1668Disable copy paste between the client and the guest. 1669 1670@item disable-agent-file-xfer 1671Disable spice-vdagent based file-xfer between the client and the guest. 1672 1673@item tls-port=<nr> 1674Set the TCP port spice is listening on for encrypted channels. 1675 1676@item x509-dir=<dir> 1677Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1678 1679@item x509-key-file=<file> 1680@itemx x509-key-password=<file> 1681@itemx x509-cert-file=<file> 1682@itemx x509-cacert-file=<file> 1683@itemx x509-dh-key-file=<file> 1684The x509 file names can also be configured individually. 1685 1686@item tls-ciphers=<list> 1687Specify which ciphers to use. 1688 1689@item tls-channel=[main|display|cursor|inputs|record|playback] 1690@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1691Force specific channel to be used with or without TLS encryption. The 1692options can be specified multiple times to configure multiple 1693channels. The special name "default" can be used to set the default 1694mode. For channels which are not explicitly forced into one mode the 1695spice client is allowed to pick tls/plaintext as he pleases. 1696 1697@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1698Configure image compression (lossless). 1699Default is auto_glz. 1700 1701@item jpeg-wan-compression=[auto|never|always] 1702@itemx zlib-glz-wan-compression=[auto|never|always] 1703Configure wan image compression (lossy for slow links). 1704Default is auto. 1705 1706@item streaming-video=[off|all|filter] 1707Configure video stream detection. Default is off. 1708 1709@item agent-mouse=[on|off] 1710Enable/disable passing mouse events via vdagent. Default is on. 1711 1712@item playback-compression=[on|off] 1713Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1714 1715@item seamless-migration=[on|off] 1716Enable/disable spice seamless migration. Default is off. 1717 1718@item gl=[on|off] 1719Enable/disable OpenGL context. Default is off. 1720 1721@item rendernode=<file> 1722DRM render node for OpenGL rendering. If not specified, it will pick 1723the first available. (Since 2.9) 1724 1725@end table 1726ETEXI 1727 1728DEF("portrait", 0, QEMU_OPTION_portrait, 1729 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1730 QEMU_ARCH_ALL) 1731STEXI 1732@item -portrait 1733@findex -portrait 1734Rotate graphical output 90 deg left (only PXA LCD). 1735ETEXI 1736 1737DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1738 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1739 QEMU_ARCH_ALL) 1740STEXI 1741@item -rotate @var{deg} 1742@findex -rotate 1743Rotate graphical output some deg left (only PXA LCD). 1744ETEXI 1745 1746DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1747 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1748 " select video card type\n", QEMU_ARCH_ALL) 1749STEXI 1750@item -vga @var{type} 1751@findex -vga 1752Select type of VGA card to emulate. Valid values for @var{type} are 1753@table @option 1754@item cirrus 1755Cirrus Logic GD5446 Video card. All Windows versions starting from 1756Windows 95 should recognize and use this graphic card. For optimal 1757performances, use 16 bit color depth in the guest and the host OS. 1758(This card was the default before QEMU 2.2) 1759@item std 1760Standard VGA card with Bochs VBE extensions. If your guest OS 1761supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1762to use high resolution modes (>= 1280x1024x16) then you should use 1763this option. (This card is the default since QEMU 2.2) 1764@item vmware 1765VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1766recent XFree86/XOrg server or Windows guest with a driver for this 1767card. 1768@item qxl 1769QXL paravirtual graphic card. It is VGA compatible (including VESA 17702.0 VBE support). Works best with qxl guest drivers installed though. 1771Recommended choice when using the spice protocol. 1772@item tcx 1773(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1774sun4m machines and offers both 8-bit and 24-bit colour depths at a 1775fixed resolution of 1024x768. 1776@item cg3 1777(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1778for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1779resolutions aimed at people wishing to run older Solaris versions. 1780@item virtio 1781Virtio VGA card. 1782@item none 1783Disable VGA card. 1784@end table 1785ETEXI 1786 1787DEF("full-screen", 0, QEMU_OPTION_full_screen, 1788 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1789STEXI 1790@item -full-screen 1791@findex -full-screen 1792Start in full screen. 1793ETEXI 1794 1795DEF("g", 1, QEMU_OPTION_g , 1796 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1797 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1798STEXI 1799@item -g @var{width}x@var{height}[x@var{depth}] 1800@findex -g 1801Set the initial graphical resolution and depth (PPC, SPARC only). 1802ETEXI 1803 1804DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1805 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1806STEXI 1807@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1808@findex -vnc 1809Normally, if QEMU is compiled with graphical window support, it displays 1810output such as guest graphics, guest console, and the QEMU monitor in a 1811window. With this option, you can have QEMU listen on VNC display 1812@var{display} and redirect the VGA display over the VNC session. It is 1813very useful to enable the usb tablet device when using this option 1814(option @option{-device usb-tablet}). When using the VNC display, you 1815must use the @option{-k} parameter to set the keyboard layout if you are 1816not using en-us. Valid syntax for the @var{display} is 1817 1818@table @option 1819 1820@item to=@var{L} 1821 1822With this option, QEMU will try next available VNC @var{display}s, until the 1823number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1824available, e.g. port 5900+@var{display} is already used by another 1825application. By default, to=0. 1826 1827@item @var{host}:@var{d} 1828 1829TCP connections will only be allowed from @var{host} on display @var{d}. 1830By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1831be omitted in which case the server will accept connections from any host. 1832 1833@item unix:@var{path} 1834 1835Connections will be allowed over UNIX domain sockets where @var{path} is the 1836location of a unix socket to listen for connections on. 1837 1838@item none 1839 1840VNC is initialized but not started. The monitor @code{change} command 1841can be used to later start the VNC server. 1842 1843@end table 1844 1845Following the @var{display} value there may be one or more @var{option} flags 1846separated by commas. Valid options are 1847 1848@table @option 1849 1850@item reverse 1851 1852Connect to a listening VNC client via a ``reverse'' connection. The 1853client is specified by the @var{display}. For reverse network 1854connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1855is a TCP port number, not a display number. 1856 1857@item websocket 1858 1859Opens an additional TCP listening port dedicated to VNC Websocket connections. 1860If a bare @var{websocket} option is given, the Websocket port is 18615700+@var{display}. An alternative port can be specified with the 1862syntax @code{websocket}=@var{port}. 1863 1864If @var{host} is specified connections will only be allowed from this host. 1865It is possible to control the websocket listen address independently, using 1866the syntax @code{websocket}=@var{host}:@var{port}. 1867 1868If no TLS credentials are provided, the websocket connection runs in 1869unencrypted mode. If TLS credentials are provided, the websocket connection 1870requires encrypted client connections. 1871 1872@item password 1873 1874Require that password based authentication is used for client connections. 1875 1876The password must be set separately using the @code{set_password} command in 1877the @ref{pcsys_monitor}. The syntax to change your password is: 1878@code{set_password <protocol> <password>} where <protocol> could be either 1879"vnc" or "spice". 1880 1881If you would like to change <protocol> password expiration, you should use 1882@code{expire_password <protocol> <expiration-time>} where expiration time could 1883be one of the following options: now, never, +seconds or UNIX time of 1884expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1885to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1886date and time). 1887 1888You can also use keywords "now" or "never" for the expiration time to 1889allow <protocol> password to expire immediately or never expire. 1890 1891@item tls-creds=@var{ID} 1892 1893Provides the ID of a set of TLS credentials to use to secure the 1894VNC server. They will apply to both the normal VNC server socket 1895and the websocket socket (if enabled). Setting TLS credentials 1896will cause the VNC server socket to enable the VeNCrypt auth 1897mechanism. The credentials should have been previously created 1898using the @option{-object tls-creds} argument. 1899 1900@item tls-authz=@var{ID} 1901 1902Provides the ID of the QAuthZ authorization object against which 1903the client's x509 distinguished name will validated. This object is 1904only resolved at time of use, so can be deleted and recreated on the 1905fly while the VNC server is active. If missing, it will default 1906to denying access. 1907 1908@item sasl 1909 1910Require that the client use SASL to authenticate with the VNC server. 1911The exact choice of authentication method used is controlled from the 1912system / user's SASL configuration file for the 'qemu' service. This 1913is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1914unprivileged user, an environment variable SASL_CONF_PATH can be used 1915to make it search alternate locations for the service config. 1916While some SASL auth methods can also provide data encryption (eg GSSAPI), 1917it is recommended that SASL always be combined with the 'tls' and 1918'x509' settings to enable use of SSL and server certificates. This 1919ensures a data encryption preventing compromise of authentication 1920credentials. See the @ref{vnc_security} section for details on using 1921SASL authentication. 1922 1923@item sasl-authz=@var{ID} 1924 1925Provides the ID of the QAuthZ authorization object against which 1926the client's SASL username will validated. This object is 1927only resolved at time of use, so can be deleted and recreated on the 1928fly while the VNC server is active. If missing, it will default 1929to denying access. 1930 1931@item acl 1932 1933Legacy method for enabling authorization of clients against the 1934x509 distinguished name and SASL username. It results in the creation 1935of two @code{authz-list} objects with IDs of @code{vnc.username} and 1936@code{vnc.x509dname}. The rules for these objects must be configured 1937with the HMP ACL commands. 1938 1939This option is deprecated and should no longer be used. The new 1940@option{sasl-authz} and @option{tls-authz} options are a 1941replacement. 1942 1943@item lossy 1944 1945Enable lossy compression methods (gradient, JPEG, ...). If this 1946option is set, VNC client may receive lossy framebuffer updates 1947depending on its encoding settings. Enabling this option can save 1948a lot of bandwidth at the expense of quality. 1949 1950@item non-adaptive 1951 1952Disable adaptive encodings. Adaptive encodings are enabled by default. 1953An adaptive encoding will try to detect frequently updated screen regions, 1954and send updates in these regions using a lossy encoding (like JPEG). 1955This can be really helpful to save bandwidth when playing videos. Disabling 1956adaptive encodings restores the original static behavior of encodings 1957like Tight. 1958 1959@item share=[allow-exclusive|force-shared|ignore] 1960 1961Set display sharing policy. 'allow-exclusive' allows clients to ask 1962for exclusive access. As suggested by the rfb spec this is 1963implemented by dropping other connections. Connecting multiple 1964clients in parallel requires all clients asking for a shared session 1965(vncviewer: -shared switch). This is the default. 'force-shared' 1966disables exclusive client access. Useful for shared desktop sessions, 1967where you don't want someone forgetting specify -shared disconnect 1968everybody else. 'ignore' completely ignores the shared flag and 1969allows everybody connect unconditionally. Doesn't conform to the rfb 1970spec but is traditional QEMU behavior. 1971 1972@item key-delay-ms 1973 1974Set keyboard delay, for key down and key up events, in milliseconds. 1975Default is 10. Keyboards are low-bandwidth devices, so this slowdown 1976can help the device and guest to keep up and not lose events in case 1977events are arriving in bulk. Possible causes for the latter are flaky 1978network connections, or scripts for automated testing. 1979 1980@end table 1981ETEXI 1982 1983STEXI 1984@end table 1985ETEXI 1986ARCHHEADING(, QEMU_ARCH_I386) 1987 1988ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1989STEXI 1990@table @option 1991ETEXI 1992 1993DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1994 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1995 QEMU_ARCH_I386) 1996STEXI 1997@item -win2k-hack 1998@findex -win2k-hack 1999Use it when installing Windows 2000 to avoid a disk full bug. After 2000Windows 2000 is installed, you no longer need this option (this option 2001slows down the IDE transfers). 2002ETEXI 2003 2004DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2005 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2006 QEMU_ARCH_I386) 2007STEXI 2008@item -no-fd-bootchk 2009@findex -no-fd-bootchk 2010Disable boot signature checking for floppy disks in BIOS. May 2011be needed to boot from old floppy disks. 2012ETEXI 2013 2014DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2015 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2016STEXI 2017@item -no-acpi 2018@findex -no-acpi 2019Disable ACPI (Advanced Configuration and Power Interface) support. Use 2020it if your guest OS complains about ACPI problems (PC target machine 2021only). 2022ETEXI 2023 2024DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2025 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2026STEXI 2027@item -no-hpet 2028@findex -no-hpet 2029Disable HPET support. 2030ETEXI 2031 2032DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2033 "-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" 2034 " ACPI table description\n", QEMU_ARCH_I386) 2035STEXI 2036@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}]...] 2037@findex -acpitable 2038Add ACPI table with specified header fields and context from specified files. 2039For file=, take whole ACPI table from the specified files, including all 2040ACPI headers (possible overridden by other options). 2041For data=, only data 2042portion of the table is used, all header information is specified in the 2043command line. 2044If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2045fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2046to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2047spec. 2048ETEXI 2049 2050DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2051 "-smbios file=binary\n" 2052 " load SMBIOS entry from binary file\n" 2053 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2054 " [,uefi=on|off]\n" 2055 " specify SMBIOS type 0 fields\n" 2056 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2057 " [,uuid=uuid][,sku=str][,family=str]\n" 2058 " specify SMBIOS type 1 fields\n" 2059 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2060 " [,asset=str][,location=str]\n" 2061 " specify SMBIOS type 2 fields\n" 2062 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2063 " [,sku=str]\n" 2064 " specify SMBIOS type 3 fields\n" 2065 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2066 " [,asset=str][,part=str]\n" 2067 " specify SMBIOS type 4 fields\n" 2068 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2069 " [,asset=str][,part=str][,speed=%d]\n" 2070 " specify SMBIOS type 17 fields\n", 2071 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2072STEXI 2073@item -smbios file=@var{binary} 2074@findex -smbios 2075Load SMBIOS entry from binary file. 2076 2077@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2078Specify SMBIOS type 0 fields 2079 2080@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}] 2081Specify SMBIOS type 1 fields 2082 2083@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}][,family=@var{str}] 2084Specify SMBIOS type 2 fields 2085 2086@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2087Specify SMBIOS type 3 fields 2088 2089@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2090Specify SMBIOS type 4 fields 2091 2092@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}] 2093Specify SMBIOS type 17 fields 2094ETEXI 2095 2096STEXI 2097@end table 2098ETEXI 2099DEFHEADING() 2100 2101DEFHEADING(Network options:) 2102STEXI 2103@table @option 2104ETEXI 2105 2106DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2107#ifdef CONFIG_SLIRP 2108 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2109 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2110 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2111 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2112 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2113#ifndef _WIN32 2114 "[,smb=dir[,smbserver=addr]]\n" 2115#endif 2116 " configure a user mode network backend with ID 'str',\n" 2117 " its DHCP server and optional services\n" 2118#endif 2119#ifdef _WIN32 2120 "-netdev tap,id=str,ifname=name\n" 2121 " configure a host TAP network backend with ID 'str'\n" 2122#else 2123 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2124 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2125 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2126 " [,poll-us=n]\n" 2127 " configure a host TAP network backend with ID 'str'\n" 2128 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2129 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2130 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2131 " to deconfigure it\n" 2132 " use '[down]script=no' to disable script execution\n" 2133 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2134 " configure it\n" 2135 " use 'fd=h' to connect to an already opened TAP interface\n" 2136 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2137 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2138 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2139 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2140 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2141 " use vhost=on to enable experimental in kernel accelerator\n" 2142 " (only has effect for virtio guests which use MSIX)\n" 2143 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2144 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2145 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2146 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2147 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2148 " spent on busy polling for vhost net\n" 2149 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2150 " configure a host TAP network backend with ID 'str' that is\n" 2151 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2152 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2153#endif 2154#ifdef __linux__ 2155 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2156 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2157 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2158 " [,rxcookie=rxcookie][,offset=offset]\n" 2159 " configure a network backend with ID 'str' connected to\n" 2160 " an Ethernet over L2TPv3 pseudowire.\n" 2161 " Linux kernel 3.3+ as well as most routers can talk\n" 2162 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2163 " VM to a router and even VM to Host. It is a nearly-universal\n" 2164 " standard (RFC3391). Note - this implementation uses static\n" 2165 " pre-configured tunnels (same as the Linux kernel).\n" 2166 " use 'src=' to specify source address\n" 2167 " use 'dst=' to specify destination address\n" 2168 " use 'udp=on' to specify udp encapsulation\n" 2169 " use 'srcport=' to specify source udp port\n" 2170 " use 'dstport=' to specify destination udp port\n" 2171 " use 'ipv6=on' to force v6\n" 2172 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2173 " well as a weak security measure\n" 2174 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2175 " use 'txcookie=0x012345678' to specify a txcookie\n" 2176 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2177 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2178 " use 'pincounter=on' to work around broken counter handling in peer\n" 2179 " use 'offset=X' to add an extra offset between header and data\n" 2180#endif 2181 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2182 " configure a network backend to connect to another network\n" 2183 " using a socket connection\n" 2184 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2185 " configure a network backend to connect to a multicast maddr and port\n" 2186 " use 'localaddr=addr' to specify the host address to send packets from\n" 2187 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2188 " configure a network backend to connect to another network\n" 2189 " using an UDP tunnel\n" 2190#ifdef CONFIG_VDE 2191 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2192 " configure a network backend to connect to port 'n' of a vde switch\n" 2193 " running on host and listening for incoming connections on 'socketpath'.\n" 2194 " Use group 'groupname' and mode 'octalmode' to change default\n" 2195 " ownership and permissions for communication port.\n" 2196#endif 2197#ifdef CONFIG_NETMAP 2198 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2199 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2200 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2201 " netmap device, defaults to '/dev/netmap')\n" 2202#endif 2203#ifdef CONFIG_POSIX 2204 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2205 " configure a vhost-user network, backed by a chardev 'dev'\n" 2206#endif 2207 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2208 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2209DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2210 "-nic [tap|bridge|" 2211#ifdef CONFIG_SLIRP 2212 "user|" 2213#endif 2214#ifdef __linux__ 2215 "l2tpv3|" 2216#endif 2217#ifdef CONFIG_VDE 2218 "vde|" 2219#endif 2220#ifdef CONFIG_NETMAP 2221 "netmap|" 2222#endif 2223#ifdef CONFIG_POSIX 2224 "vhost-user|" 2225#endif 2226 "socket][,option][,...][mac=macaddr]\n" 2227 " initialize an on-board / default host NIC (using MAC address\n" 2228 " macaddr) and connect it to the given host network backend\n" 2229 "-nic none use it alone to have zero network devices (the default is to\n" 2230 " provided a 'user' network connection)\n", 2231 QEMU_ARCH_ALL) 2232DEF("net", HAS_ARG, QEMU_OPTION_net, 2233 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2234 " configure or create an on-board (or machine default) NIC and\n" 2235 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2236 "-net [" 2237#ifdef CONFIG_SLIRP 2238 "user|" 2239#endif 2240 "tap|" 2241 "bridge|" 2242#ifdef CONFIG_VDE 2243 "vde|" 2244#endif 2245#ifdef CONFIG_NETMAP 2246 "netmap|" 2247#endif 2248 "socket][,option][,option][,...]\n" 2249 " old way to initialize a host network interface\n" 2250 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2251STEXI 2252@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2253@findex -nic 2254This option is a shortcut for configuring both the on-board (default) guest 2255NIC hardware and the host network backend in one go. The host backend options 2256are the same as with the corresponding @option{-netdev} options below. 2257The guest NIC model can be set with @option{model=@var{modelname}}. 2258Use @option{model=help} to list the available device types. 2259The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2260 2261The following two example do exactly the same, to show how @option{-nic} can 2262be used to shorten the command line length (note that the e1000 is the default 2263on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2264@example 2265qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2266qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2267@end example 2268 2269@item -nic none 2270Indicate that no network devices should be configured. It is used to override 2271the default configuration (default NIC with ``user'' host network backend) 2272which is activated if no other networking options are provided. 2273 2274@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2275@findex -netdev 2276Configure user mode host network backend which requires no administrator 2277privilege to run. Valid options are: 2278 2279@table @option 2280@item id=@var{id} 2281Assign symbolic name for use in monitor commands. 2282 2283@item ipv4=on|off and ipv6=on|off 2284Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2285both protocols are enabled. 2286 2287@item net=@var{addr}[/@var{mask}] 2288Set IP network address the guest will see. Optionally specify the netmask, 2289either in the form a.b.c.d or as number of valid top-most bits. Default is 229010.0.2.0/24. 2291 2292@item host=@var{addr} 2293Specify the guest-visible address of the host. Default is the 2nd IP in the 2294guest network, i.e. x.x.x.2. 2295 2296@item ipv6-net=@var{addr}[/@var{int}] 2297Set IPv6 network address the guest will see (default is fec0::/64). The 2298network prefix is given in the usual hexadecimal IPv6 address 2299notation. The prefix size is optional, and is given as the number of 2300valid top-most bits (default is 64). 2301 2302@item ipv6-host=@var{addr} 2303Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2304the guest network, i.e. xxxx::2. 2305 2306@item restrict=on|off 2307If this option is enabled, the guest will be isolated, i.e. it will not be 2308able to contact the host and no guest IP packets will be routed over the host 2309to the outside. This option does not affect any explicitly set forwarding rules. 2310 2311@item hostname=@var{name} 2312Specifies the client hostname reported by the built-in DHCP server. 2313 2314@item dhcpstart=@var{addr} 2315Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2316is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2317 2318@item dns=@var{addr} 2319Specify the guest-visible address of the virtual nameserver. The address must 2320be different from the host address. Default is the 3rd IP in the guest network, 2321i.e. x.x.x.3. 2322 2323@item ipv6-dns=@var{addr} 2324Specify the guest-visible address of the IPv6 virtual nameserver. The address 2325must be different from the host address. Default is the 3rd IP in the guest 2326network, i.e. xxxx::3. 2327 2328@item dnssearch=@var{domain} 2329Provides an entry for the domain-search list sent by the built-in 2330DHCP server. More than one domain suffix can be transmitted by specifying 2331this option multiple times. If supported, this will cause the guest to 2332automatically try to append the given domain suffix(es) in case a domain name 2333can not be resolved. 2334 2335Example: 2336@example 2337qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2338@end example 2339 2340@item domainname=@var{domain} 2341Specifies the client domain name reported by the built-in DHCP server. 2342 2343@item tftp=@var{dir} 2344When using the user mode network stack, activate a built-in TFTP 2345server. The files in @var{dir} will be exposed as the root of a TFTP server. 2346The TFTP client on the guest must be configured in binary mode (use the command 2347@code{bin} of the Unix TFTP client). 2348 2349@item tftp-server-name=@var{name} 2350In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 235166). This can be used to advise the guest to load boot files or configurations 2352from a different server than the host address. 2353 2354@item bootfile=@var{file} 2355When using the user mode network stack, broadcast @var{file} as the BOOTP 2356filename. In conjunction with @option{tftp}, this can be used to network boot 2357a guest from a local directory. 2358 2359Example (using pxelinux): 2360@example 2361qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \ 2362 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2363@end example 2364 2365@item smb=@var{dir}[,smbserver=@var{addr}] 2366When using the user mode network stack, activate a built-in SMB 2367server so that Windows OSes can access to the host files in @file{@var{dir}} 2368transparently. The IP address of the SMB server can be set to @var{addr}. By 2369default the 4th IP in the guest network is used, i.e. x.x.x.4. 2370 2371In the guest Windows OS, the line: 2372@example 237310.0.2.4 smbserver 2374@end example 2375must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2376or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2377 2378Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2379 2380Note that a SAMBA server must be installed on the host OS. 2381 2382@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2383Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2384the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2385@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2386given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2387be bound to a specific host interface. If no connection type is set, TCP is 2388used. This option can be given multiple times. 2389 2390For example, to redirect host X11 connection from screen 1 to guest 2391screen 0, use the following: 2392 2393@example 2394# on the host 2395qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2396# this host xterm should open in the guest X11 server 2397xterm -display :1 2398@end example 2399 2400To redirect telnet connections from host port 5555 to telnet port on 2401the guest, use the following: 2402 2403@example 2404# on the host 2405qemu-system-i386 -nic user,hostfwd=tcp::5555-:23 2406telnet localhost 5555 2407@end example 2408 2409Then when you use on the host @code{telnet localhost 5555}, you 2410connect to the guest telnet server. 2411 2412@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2413@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2414Forward guest TCP connections to the IP address @var{server} on port @var{port} 2415to the character device @var{dev} or to a program executed by @var{cmd:command} 2416which gets spawned for each connection. This option can be given multiple times. 2417 2418You can either use a chardev directly and have that one used throughout QEMU's 2419lifetime, like in the following example: 2420 2421@example 2422# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2423# the guest accesses it 2424qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2425@end example 2426 2427Or you can execute a command on every TCP connection established by the guest, 2428so that QEMU behaves similar to an inetd process for that virtual server: 2429 2430@example 2431# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2432# and connect the TCP stream to its stdin/stdout 2433qemu-system-i386 -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2434@end example 2435 2436@end table 2437 2438@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2439Configure a host TAP network backend with ID @var{id}. 2440 2441Use the network script @var{file} to configure it and the network script 2442@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2443automatically provides one. The default network configure script is 2444@file{/etc/qemu-ifup} and the default network deconfigure script is 2445@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2446to disable script execution. 2447 2448If running QEMU as an unprivileged user, use the network helper 2449@var{helper} to configure the TAP interface and attach it to the bridge. 2450The default network helper executable is @file{/path/to/qemu-bridge-helper} 2451and the default bridge device is @file{br0}. 2452 2453@option{fd}=@var{h} can be used to specify the handle of an already 2454opened host TAP interface. 2455 2456Examples: 2457 2458@example 2459#launch a QEMU instance with the default network script 2460qemu-system-i386 linux.img -nic tap 2461@end example 2462 2463@example 2464#launch a QEMU instance with two NICs, each one connected 2465#to a TAP device 2466qemu-system-i386 linux.img \ 2467 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2468 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2469@end example 2470 2471@example 2472#launch a QEMU instance with the default network helper to 2473#connect a TAP device to bridge br0 2474qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \ 2475 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2476@end example 2477 2478@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2479Connect a host TAP network interface to a host bridge device. 2480 2481Use the network helper @var{helper} to configure the TAP interface and 2482attach it to the bridge. The default network helper executable is 2483@file{/path/to/qemu-bridge-helper} and the default bridge 2484device is @file{br0}. 2485 2486Examples: 2487 2488@example 2489#launch a QEMU instance with the default network helper to 2490#connect a TAP device to bridge br0 2491qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2492@end example 2493 2494@example 2495#launch a QEMU instance with the default network helper to 2496#connect a TAP device to bridge qemubr0 2497qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2498@end example 2499 2500@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2501 2502This host network backend can be used to connect the guest's network to 2503another QEMU virtual machine using a TCP socket connection. If @option{listen} 2504is specified, QEMU waits for incoming connections on @var{port} 2505(@var{host} is optional). @option{connect} is used to connect to 2506another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2507specifies an already opened TCP socket. 2508 2509Example: 2510@example 2511# launch a first QEMU instance 2512qemu-system-i386 linux.img \ 2513 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2514 -netdev socket,id=n1,listen=:1234 2515# connect the network of this instance to the network of the first instance 2516qemu-system-i386 linux.img \ 2517 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2518 -netdev socket,id=n2,connect=127.0.0.1:1234 2519@end example 2520 2521@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2522 2523Configure a socket host network backend to share the guest's network traffic 2524with another QEMU virtual machines using a UDP multicast socket, effectively 2525making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2526NOTES: 2527@enumerate 2528@item 2529Several QEMU can be running on different hosts and share same bus (assuming 2530correct multicast setup for these hosts). 2531@item 2532mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2533@url{http://user-mode-linux.sf.net}. 2534@item 2535Use @option{fd=h} to specify an already opened UDP multicast socket. 2536@end enumerate 2537 2538Example: 2539@example 2540# launch one QEMU instance 2541qemu-system-i386 linux.img \ 2542 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2543 -netdev socket,id=n1,mcast=230.0.0.1:1234 2544# launch another QEMU instance on same "bus" 2545qemu-system-i386 linux.img \ 2546 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2547 -netdev socket,id=n2,mcast=230.0.0.1:1234 2548# launch yet another QEMU instance on same "bus" 2549qemu-system-i386 linux.img \ 2550 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2551 -netdev socket,id=n3,mcast=230.0.0.1:1234 2552@end example 2553 2554Example (User Mode Linux compat.): 2555@example 2556# launch QEMU instance (note mcast address selected is UML's default) 2557qemu-system-i386 linux.img \ 2558 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2559 -netdev socket,id=n1,mcast=239.192.168.1:1102 2560# launch UML 2561/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2562@end example 2563 2564Example (send packets from host's 1.2.3.4): 2565@example 2566qemu-system-i386 linux.img \ 2567 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2568 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2569@end example 2570 2571@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}] 2572Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2573popular protocol to transport Ethernet (and other Layer 2) data frames between 2574two systems. It is present in routers, firewalls and the Linux kernel 2575(from version 3.3 onwards). 2576 2577This transport allows a VM to communicate to another VM, router or firewall directly. 2578 2579@table @option 2580@item src=@var{srcaddr} 2581 source address (mandatory) 2582@item dst=@var{dstaddr} 2583 destination address (mandatory) 2584@item udp 2585 select udp encapsulation (default is ip). 2586@item srcport=@var{srcport} 2587 source udp port. 2588@item dstport=@var{dstport} 2589 destination udp port. 2590@item ipv6 2591 force v6, otherwise defaults to v4. 2592@item rxcookie=@var{rxcookie} 2593@itemx txcookie=@var{txcookie} 2594 Cookies are a weak form of security in the l2tpv3 specification. 2595Their function is mostly to prevent misconfiguration. By default they are 32 2596bit. 2597@item cookie64 2598 Set cookie size to 64 bit instead of the default 32 2599@item counter=off 2600 Force a 'cut-down' L2TPv3 with no counter as in 2601draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2602@item pincounter=on 2603 Work around broken counter handling in peer. This may also help on 2604networks which have packet reorder. 2605@item offset=@var{offset} 2606 Add an extra offset between header and data 2607@end table 2608 2609For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2610on the remote Linux host 1.2.3.4: 2611@example 2612# Setup tunnel on linux host using raw ip as encapsulation 2613# on 1.2.3.4 2614ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2615 encap udp udp_sport 16384 udp_dport 16384 2616ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2617 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2618ifconfig vmtunnel0 mtu 1500 2619ifconfig vmtunnel0 up 2620brctl addif br-lan vmtunnel0 2621 2622 2623# on 4.3.2.1 2624# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2625 2626qemu-system-i386 linux.img -device e1000,netdev=n1 \ 2627 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2628 2629@end example 2630 2631@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2632Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2633listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2634and MODE @var{octalmode} to change default ownership and permissions for 2635communication port. This option is only available if QEMU has been compiled 2636with vde support enabled. 2637 2638Example: 2639@example 2640# launch vde switch 2641vde_switch -F -sock /tmp/myswitch 2642# launch QEMU instance 2643qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch 2644@end example 2645 2646@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2647 2648Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2649be a unix domain socket backed one. The vhost-user uses a specifically defined 2650protocol to pass vhost ioctl replacement messages to an application on the other 2651end of the socket. On non-MSIX guests, the feature can be forced with 2652@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2653be created for multiqueue vhost-user. 2654 2655Example: 2656@example 2657qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2658 -numa node,memdev=mem \ 2659 -chardev socket,id=chr0,path=/path/to/socket \ 2660 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2661 -device virtio-net-pci,netdev=net0 2662@end example 2663 2664@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2665 2666Create a hub port on the emulated hub with ID @var{hubid}. 2667 2668The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2669single netdev. Alternatively, you can also connect the hubport to another 2670netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2671 2672@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2673@findex -net 2674Legacy option to configure or create an on-board (or machine default) Network 2675Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2676the default hub), or to the netdev @var{nd}. 2677The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2678can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2679only), and a @var{name} can be assigned for use in monitor commands. 2680Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2681that the card should have; this option currently only affects virtio cards; set 2682@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2683NIC is created. QEMU can emulate several different models of network card. 2684Use @code{-net nic,model=help} for a list of available devices for your target. 2685 2686@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2687Configure a host network backend (with the options corresponding to the same 2688@option{-netdev} option) and connect it to the emulated hub 0 (the default 2689hub). Use @var{name} to specify the name of the hub port. 2690ETEXI 2691 2692STEXI 2693@end table 2694ETEXI 2695DEFHEADING() 2696 2697DEFHEADING(Character device options:) 2698 2699DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2700 "-chardev help\n" 2701 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2702 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2703 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2704 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2705 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2706 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2707 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2708 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2709 " [,logfile=PATH][,logappend=on|off]\n" 2710 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2711 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2712 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2713 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2714 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2715 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2716#ifdef _WIN32 2717 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2718 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2719#else 2720 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2721 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2722#endif 2723#ifdef CONFIG_BRLAPI 2724 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2725#endif 2726#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2727 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2728 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2729 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2730#endif 2731#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2732 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2733 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2734#endif 2735#if defined(CONFIG_SPICE) 2736 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2737 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2738#endif 2739 , QEMU_ARCH_ALL 2740) 2741 2742STEXI 2743 2744The general form of a character device option is: 2745@table @option 2746@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2747@findex -chardev 2748Backend is one of: 2749@option{null}, 2750@option{socket}, 2751@option{udp}, 2752@option{msmouse}, 2753@option{vc}, 2754@option{ringbuf}, 2755@option{file}, 2756@option{pipe}, 2757@option{console}, 2758@option{serial}, 2759@option{pty}, 2760@option{stdio}, 2761@option{braille}, 2762@option{tty}, 2763@option{parallel}, 2764@option{parport}, 2765@option{spicevmc}, 2766@option{spiceport}. 2767The specific backend will determine the applicable options. 2768 2769Use @code{-chardev help} to print all available chardev backend types. 2770 2771All devices must have an id, which can be any string up to 127 characters long. 2772It is used to uniquely identify this device in other command line directives. 2773 2774A character device may be used in multiplexing mode by multiple front-ends. 2775Specify @option{mux=on} to enable this mode. 2776A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2777backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2778If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2779create a multiplexer with your specified ID, and you can then configure multiple 2780front ends to use that chardev ID for their input/output. Up to four different 2781front ends can be connected to a single multiplexed chardev. (Without 2782multiplexing enabled, a chardev can only be used by a single front end.) 2783For instance you could use this to allow a single stdio chardev to be used by 2784two serial ports and the QEMU monitor: 2785 2786@example 2787-chardev stdio,mux=on,id=char0 \ 2788-mon chardev=char0,mode=readline \ 2789-serial chardev:char0 \ 2790-serial chardev:char0 2791@end example 2792 2793You can have more than one multiplexer in a system configuration; for instance 2794you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2795multiplexed between the QEMU monitor and a parallel port: 2796 2797@example 2798-chardev stdio,mux=on,id=char0 \ 2799-mon chardev=char0,mode=readline \ 2800-parallel chardev:char0 \ 2801-chardev tcp,...,mux=on,id=char1 \ 2802-serial chardev:char1 \ 2803-serial chardev:char1 2804@end example 2805 2806When you're using a multiplexed character device, some escape sequences are 2807interpreted in the input. @xref{mux_keys, Keys in the character backend 2808multiplexer}. 2809 2810Note that some other command line options may implicitly create multiplexed 2811character backends; for instance @option{-serial mon:stdio} creates a 2812multiplexed stdio backend connected to the serial port and the QEMU monitor, 2813and @option{-nographic} also multiplexes the console and the monitor to 2814stdio. 2815 2816There is currently no support for multiplexing in the other direction 2817(where a single QEMU front end takes input and output from multiple chardevs). 2818 2819Every backend supports the @option{logfile} option, which supplies the path 2820to a file to record all data transmitted via the backend. The @option{logappend} 2821option controls whether the log file will be truncated or appended to when 2822opened. 2823 2824@end table 2825 2826The available backends are: 2827 2828@table @option 2829@item -chardev null,id=@var{id} 2830A void device. This device will not emit any data, and will drop any data it 2831receives. The null backend does not take any options. 2832 2833@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}] 2834 2835Create a two-way stream socket, which can be either a TCP or a unix socket. A 2836unix socket will be created if @option{path} is specified. Behaviour is 2837undefined if TCP options are specified for a unix socket. 2838 2839@option{server} specifies that the socket shall be a listening socket. 2840 2841@option{nowait} specifies that QEMU should not block waiting for a client to 2842connect to a listening socket. 2843 2844@option{telnet} specifies that traffic on the socket should interpret telnet 2845escape sequences. 2846 2847@option{websocket} specifies that the socket uses WebSocket protocol for 2848communication. 2849 2850@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2851the remote end goes away. qemu will delay this many seconds and then attempt 2852to reconnect. Zero disables reconnecting, and is the default. 2853 2854@option{tls-creds} requests enablement of the TLS protocol for encryption, 2855and specifies the id of the TLS credentials to use for the handshake. The 2856credentials must be previously created with the @option{-object tls-creds} 2857argument. 2858 2859@option{tls-auth} provides the ID of the QAuthZ authorization object against 2860which the client's x509 distinguished name will be validated. This object is 2861only resolved at time of use, so can be deleted and recreated on the fly 2862while the chardev server is active. If missing, it will default to denying 2863access. 2864 2865TCP and unix socket options are given below: 2866 2867@table @option 2868 2869@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2870 2871@option{host} for a listening socket specifies the local address to be bound. 2872For a connecting socket species the remote host to connect to. @option{host} is 2873optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2874 2875@option{port} for a listening socket specifies the local port to be bound. For a 2876connecting socket specifies the port on the remote host to connect to. 2877@option{port} can be given as either a port number or a service name. 2878@option{port} is required. 2879 2880@option{to} is only relevant to listening sockets. If it is specified, and 2881@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2882to and including @option{to} until it succeeds. @option{to} must be specified 2883as a port number. 2884 2885@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2886If neither is specified the socket may use either protocol. 2887 2888@option{nodelay} disables the Nagle algorithm. 2889 2890@item unix options: path=@var{path} 2891 2892@option{path} specifies the local path of the unix socket. @option{path} is 2893required. 2894 2895@end table 2896 2897@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2898 2899Sends all traffic from the guest to a remote host over UDP. 2900 2901@option{host} specifies the remote host to connect to. If not specified it 2902defaults to @code{localhost}. 2903 2904@option{port} specifies the port on the remote host to connect to. @option{port} 2905is required. 2906 2907@option{localaddr} specifies the local address to bind to. If not specified it 2908defaults to @code{0.0.0.0}. 2909 2910@option{localport} specifies the local port to bind to. If not specified any 2911available local port will be used. 2912 2913@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2914If neither is specified the device may use either protocol. 2915 2916@item -chardev msmouse,id=@var{id} 2917 2918Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2919take any options. 2920 2921@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 2922 2923Connect to a QEMU text console. @option{vc} may optionally be given a specific 2924size. 2925 2926@option{width} and @option{height} specify the width and height respectively of 2927the console, in pixels. 2928 2929@option{cols} and @option{rows} specify that the console be sized to fit a text 2930console with the given dimensions. 2931 2932@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 2933 2934Create a ring buffer with fixed size @option{size}. 2935@var{size} must be a power of two and defaults to @code{64K}. 2936 2937@item -chardev file,id=@var{id},path=@var{path} 2938 2939Log all traffic received from the guest to a file. 2940 2941@option{path} specifies the path of the file to be opened. This file will be 2942created if it does not already exist, and overwritten if it does. @option{path} 2943is required. 2944 2945@item -chardev pipe,id=@var{id},path=@var{path} 2946 2947Create a two-way connection to the guest. The behaviour differs slightly between 2948Windows hosts and other hosts: 2949 2950On Windows, a single duplex pipe will be created at 2951@file{\\.pipe\@option{path}}. 2952 2953On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2954@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2955received by the guest. Data written by the guest can be read from 2956@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2957be present. 2958 2959@option{path} forms part of the pipe path as described above. @option{path} is 2960required. 2961 2962@item -chardev console,id=@var{id} 2963 2964Send traffic from the guest to QEMU's standard output. @option{console} does not 2965take any options. 2966 2967@option{console} is only available on Windows hosts. 2968 2969@item -chardev serial,id=@var{id},path=@option{path} 2970 2971Send traffic from the guest to a serial device on the host. 2972 2973On Unix hosts serial will actually accept any tty device, 2974not only serial lines. 2975 2976@option{path} specifies the name of the serial device to open. 2977 2978@item -chardev pty,id=@var{id} 2979 2980Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2981not take any options. 2982 2983@option{pty} is not available on Windows hosts. 2984 2985@item -chardev stdio,id=@var{id}[,signal=on|off] 2986Connect to standard input and standard output of the QEMU process. 2987 2988@option{signal} controls if signals are enabled on the terminal, that includes 2989exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2990default, use @option{signal=off} to disable it. 2991 2992@item -chardev braille,id=@var{id} 2993 2994Connect to a local BrlAPI server. @option{braille} does not take any options. 2995 2996@item -chardev tty,id=@var{id},path=@var{path} 2997 2998@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2999DragonFlyBSD hosts. It is an alias for @option{serial}. 3000 3001@option{path} specifies the path to the tty. @option{path} is required. 3002 3003@item -chardev parallel,id=@var{id},path=@var{path} 3004@itemx -chardev parport,id=@var{id},path=@var{path} 3005 3006@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3007 3008Connect to a local parallel port. 3009 3010@option{path} specifies the path to the parallel port device. @option{path} is 3011required. 3012 3013@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3014 3015@option{spicevmc} is only available when spice support is built in. 3016 3017@option{debug} debug level for spicevmc 3018 3019@option{name} name of spice channel to connect to 3020 3021Connect to a spice virtual machine channel, such as vdiport. 3022 3023@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3024 3025@option{spiceport} is only available when spice support is built in. 3026 3027@option{debug} debug level for spicevmc 3028 3029@option{name} name of spice port to connect to 3030 3031Connect to a spice port, allowing a Spice client to handle the traffic 3032identified by a name (preferably a fqdn). 3033ETEXI 3034 3035STEXI 3036@end table 3037ETEXI 3038DEFHEADING() 3039 3040DEFHEADING(Bluetooth(R) options:) 3041STEXI 3042@table @option 3043ETEXI 3044 3045DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3046 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3047 "-bt hci,host[:id]\n" \ 3048 " use host's HCI with the given name\n" \ 3049 "-bt hci[,vlan=n]\n" \ 3050 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3051 "-bt vhci[,vlan=n]\n" \ 3052 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3053 "-bt device:dev[,vlan=n]\n" \ 3054 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3055 QEMU_ARCH_ALL) 3056STEXI 3057@item -bt hci[...] 3058@findex -bt 3059Defines the function of the corresponding Bluetooth HCI. -bt options 3060are matched with the HCIs present in the chosen machine type. For 3061example when emulating a machine with only one HCI built into it, only 3062the first @code{-bt hci[...]} option is valid and defines the HCI's 3063logic. The Transport Layer is decided by the machine type. Currently 3064the machines @code{n800} and @code{n810} have one HCI and all other 3065machines have none. 3066 3067Note: This option and the whole bluetooth subsystem is considered as deprecated. 3068If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where 3069you describe your usecase. 3070 3071@anchor{bt-hcis} 3072The following three types are recognized: 3073 3074@table @option 3075@item -bt hci,null 3076(default) The corresponding Bluetooth HCI assumes no internal logic 3077and will not respond to any HCI commands or emit events. 3078 3079@item -bt hci,host[:@var{id}] 3080(@code{bluez} only) The corresponding HCI passes commands / events 3081to / from the physical HCI identified by the name @var{id} (default: 3082@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3083capable systems like Linux. 3084 3085@item -bt hci[,vlan=@var{n}] 3086Add a virtual, standard HCI that will participate in the Bluetooth 3087scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3088VLANs, devices inside a bluetooth network @var{n} can only communicate 3089with other devices in the same network (scatternet). 3090@end table 3091 3092@item -bt vhci[,vlan=@var{n}] 3093(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3094to the host bluetooth stack instead of to the emulated target. This 3095allows the host and target machines to participate in a common scatternet 3096and communicate. Requires the Linux @code{vhci} driver installed. Can 3097be used as following: 3098 3099@example 3100qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3101@end example 3102 3103@item -bt device:@var{dev}[,vlan=@var{n}] 3104Emulate a bluetooth device @var{dev} and place it in network @var{n} 3105(default @code{0}). QEMU can only emulate one type of bluetooth devices 3106currently: 3107 3108@table @option 3109@item keyboard 3110Virtual wireless keyboard implementing the HIDP bluetooth profile. 3111@end table 3112ETEXI 3113 3114STEXI 3115@end table 3116ETEXI 3117DEFHEADING() 3118 3119#ifdef CONFIG_TPM 3120DEFHEADING(TPM device options:) 3121 3122DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3123 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3124 " use path to provide path to a character device; default is /dev/tpm0\n" 3125 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3126 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3127 "-tpmdev emulator,id=id,chardev=dev\n" 3128 " configure the TPM device using chardev backend\n", 3129 QEMU_ARCH_ALL) 3130STEXI 3131 3132The general form of a TPM device option is: 3133@table @option 3134 3135@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3136@findex -tpmdev 3137 3138The specific backend type will determine the applicable options. 3139The @code{-tpmdev} option creates the TPM backend and requires a 3140@code{-device} option that specifies the TPM frontend interface model. 3141 3142Use @code{-tpmdev help} to print all available TPM backend types. 3143 3144@end table 3145 3146The available backends are: 3147 3148@table @option 3149 3150@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3151 3152(Linux-host only) Enable access to the host's TPM using the passthrough 3153driver. 3154 3155@option{path} specifies the path to the host's TPM device, i.e., on 3156a Linux host this would be @code{/dev/tpm0}. 3157@option{path} is optional and by default @code{/dev/tpm0} is used. 3158 3159@option{cancel-path} specifies the path to the host TPM device's sysfs 3160entry allowing for cancellation of an ongoing TPM command. 3161@option{cancel-path} is optional and by default QEMU will search for the 3162sysfs entry to use. 3163 3164Some notes about using the host's TPM with the passthrough driver: 3165 3166The TPM device accessed by the passthrough driver must not be 3167used by any other application on the host. 3168 3169Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3170the VM's firmware (BIOS/UEFI) will not be able to initialize the 3171TPM again and may therefore not show a TPM-specific menu that would 3172otherwise allow the user to configure the TPM, e.g., allow the user to 3173enable/disable or activate/deactivate the TPM. 3174Further, if TPM ownership is released from within a VM then the host's TPM 3175will get disabled and deactivated. To enable and activate the 3176TPM again afterwards, the host has to be rebooted and the user is 3177required to enter the firmware's menu to enable and activate the TPM. 3178If the TPM is left disabled and/or deactivated most TPM commands will fail. 3179 3180To create a passthrough TPM use the following two options: 3181@example 3182-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3183@end example 3184Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3185@code{tpmdev=tpm0} in the device option. 3186 3187@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3188 3189(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3190chardev backend. 3191 3192@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3193 3194To create a TPM emulator backend device with chardev socket backend: 3195@example 3196 3197-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3198 3199@end example 3200 3201ETEXI 3202 3203STEXI 3204@end table 3205ETEXI 3206DEFHEADING() 3207 3208#endif 3209 3210DEFHEADING(Linux/Multiboot boot specific:) 3211STEXI 3212 3213When using these options, you can use a given Linux or Multiboot 3214kernel without installing it in the disk image. It can be useful 3215for easier testing of various kernels. 3216 3217@table @option 3218ETEXI 3219 3220DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3221 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3222STEXI 3223@item -kernel @var{bzImage} 3224@findex -kernel 3225Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3226or in multiboot format. 3227ETEXI 3228 3229DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3230 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3231STEXI 3232@item -append @var{cmdline} 3233@findex -append 3234Use @var{cmdline} as kernel command line 3235ETEXI 3236 3237DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3238 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3239STEXI 3240@item -initrd @var{file} 3241@findex -initrd 3242Use @var{file} as initial ram disk. 3243 3244@item -initrd "@var{file1} arg=foo,@var{file2}" 3245 3246This syntax is only available with multiboot. 3247 3248Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3249first module. 3250ETEXI 3251 3252DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3253 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3254STEXI 3255@item -dtb @var{file} 3256@findex -dtb 3257Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3258on boot. 3259ETEXI 3260 3261STEXI 3262@end table 3263ETEXI 3264DEFHEADING() 3265 3266DEFHEADING(Debug/Expert options:) 3267STEXI 3268@table @option 3269ETEXI 3270 3271DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3272 "-fw_cfg [name=]<name>,file=<file>\n" 3273 " add named fw_cfg entry with contents from file\n" 3274 "-fw_cfg [name=]<name>,string=<str>\n" 3275 " add named fw_cfg entry with contents from string\n", 3276 QEMU_ARCH_ALL) 3277STEXI 3278 3279@item -fw_cfg [name=]@var{name},file=@var{file} 3280@findex -fw_cfg 3281Add named fw_cfg entry with contents from file @var{file}. 3282 3283@item -fw_cfg [name=]@var{name},string=@var{str} 3284Add named fw_cfg entry with contents from string @var{str}. 3285 3286The terminating NUL character of the contents of @var{str} will not be 3287included as part of the fw_cfg item data. To insert contents with 3288embedded NUL characters, you have to use the @var{file} parameter. 3289 3290The fw_cfg entries are passed by QEMU through to the guest. 3291 3292Example: 3293@example 3294 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3295@end example 3296creates an fw_cfg entry named opt/com.mycompany/blob with contents 3297from ./my_blob.bin. 3298 3299ETEXI 3300 3301DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3302 "-serial dev redirect the serial port to char device 'dev'\n", 3303 QEMU_ARCH_ALL) 3304STEXI 3305@item -serial @var{dev} 3306@findex -serial 3307Redirect the virtual serial port to host character device 3308@var{dev}. The default device is @code{vc} in graphical mode and 3309@code{stdio} in non graphical mode. 3310 3311This option can be used several times to simulate up to 4 serial 3312ports. 3313 3314Use @code{-serial none} to disable all serial ports. 3315 3316Available character devices are: 3317@table @option 3318@item vc[:@var{W}x@var{H}] 3319Virtual console. Optionally, a width and height can be given in pixel with 3320@example 3321vc:800x600 3322@end example 3323It is also possible to specify width or height in characters: 3324@example 3325vc:80Cx24C 3326@end example 3327@item pty 3328[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3329@item none 3330No device is allocated. 3331@item null 3332void device 3333@item chardev:@var{id} 3334Use a named character device defined with the @code{-chardev} option. 3335@item /dev/XXX 3336[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3337parameters are set according to the emulated ones. 3338@item /dev/parport@var{N} 3339[Linux only, parallel port only] Use host parallel port 3340@var{N}. Currently SPP and EPP parallel port features can be used. 3341@item file:@var{filename} 3342Write output to @var{filename}. No character can be read. 3343@item stdio 3344[Unix only] standard input/output 3345@item pipe:@var{filename} 3346name pipe @var{filename} 3347@item COM@var{n} 3348[Windows only] Use host serial port @var{n} 3349@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3350This implements UDP Net Console. 3351When @var{remote_host} or @var{src_ip} are not specified 3352they default to @code{0.0.0.0}. 3353When not using a specified @var{src_port} a random port is automatically chosen. 3354 3355If you just want a simple readonly console you can use @code{netcat} or 3356@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3357@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3358will appear in the netconsole session. 3359 3360If you plan to send characters back via netconsole or you want to stop 3361and start QEMU a lot of times, you should have QEMU use the same 3362source port each time by using something like @code{-serial 3363udp::4555@@:4556} to QEMU. Another approach is to use a patched 3364version of netcat which can listen to a TCP port and send and receive 3365characters via udp. If you have a patched version of netcat which 3366activates telnet remote echo and single char transfer, then you can 3367use the following options to set up a netcat redirector to allow 3368telnet on port 5555 to access the QEMU port. 3369@table @code 3370@item QEMU Options: 3371-serial udp::4555@@:4556 3372@item netcat options: 3373-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3374@item telnet options: 3375localhost 5555 3376@end table 3377 3378@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3379The TCP Net Console has two modes of operation. It can send the serial 3380I/O to a location or wait for a connection from a location. By default 3381the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3382the @var{server} option QEMU will wait for a client socket application 3383to connect to the port before continuing, unless the @code{nowait} 3384option was specified. The @code{nodelay} option disables the Nagle buffering 3385algorithm. The @code{reconnect} option only applies if @var{noserver} is 3386set, if the connection goes down it will attempt to reconnect at the 3387given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3388one TCP connection at a time is accepted. You can use @code{telnet} to 3389connect to the corresponding character device. 3390@table @code 3391@item Example to send tcp console to 192.168.0.2 port 4444 3392-serial tcp:192.168.0.2:4444 3393@item Example to listen and wait on port 4444 for connection 3394-serial tcp::4444,server 3395@item Example to not wait and listen on ip 192.168.0.100 port 4444 3396-serial tcp:192.168.0.100:4444,server,nowait 3397@end table 3398 3399@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3400The telnet protocol is used instead of raw tcp sockets. The options 3401work the same as if you had specified @code{-serial tcp}. The 3402difference is that the port acts like a telnet server or client using 3403telnet option negotiation. This will also allow you to send the 3404MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3405sequence. Typically in unix telnet you do it with Control-] and then 3406type "send break" followed by pressing the enter key. 3407 3408@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3409The WebSocket protocol is used instead of raw tcp socket. The port acts as 3410a WebSocket server. Client mode is not supported. 3411 3412@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3413A unix domain socket is used instead of a tcp socket. The option works the 3414same as if you had specified @code{-serial tcp} except the unix domain socket 3415@var{path} is used for connections. 3416 3417@item mon:@var{dev_string} 3418This is a special option to allow the monitor to be multiplexed onto 3419another serial port. The monitor is accessed with key sequence of 3420@key{Control-a} and then pressing @key{c}. 3421@var{dev_string} should be any one of the serial devices specified 3422above. An example to multiplex the monitor onto a telnet server 3423listening on port 4444 would be: 3424@table @code 3425@item -serial mon:telnet::4444,server,nowait 3426@end table 3427When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3428QEMU any more but will be passed to the guest instead. 3429 3430@item braille 3431Braille device. This will use BrlAPI to display the braille output on a real 3432or fake device. 3433 3434@item msmouse 3435Three button serial mouse. Configure the guest to use Microsoft protocol. 3436@end table 3437ETEXI 3438 3439DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3440 "-parallel dev redirect the parallel port to char device 'dev'\n", 3441 QEMU_ARCH_ALL) 3442STEXI 3443@item -parallel @var{dev} 3444@findex -parallel 3445Redirect the virtual parallel port to host device @var{dev} (same 3446devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3447be used to use hardware devices connected on the corresponding host 3448parallel port. 3449 3450This option can be used several times to simulate up to 3 parallel 3451ports. 3452 3453Use @code{-parallel none} to disable all parallel ports. 3454ETEXI 3455 3456DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3457 "-monitor dev redirect the monitor to char device 'dev'\n", 3458 QEMU_ARCH_ALL) 3459STEXI 3460@item -monitor @var{dev} 3461@findex -monitor 3462Redirect the monitor to host device @var{dev} (same devices as the 3463serial port). 3464The default device is @code{vc} in graphical mode and @code{stdio} in 3465non graphical mode. 3466Use @code{-monitor none} to disable the default monitor. 3467ETEXI 3468DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3469 "-qmp dev like -monitor but opens in 'control' mode\n", 3470 QEMU_ARCH_ALL) 3471STEXI 3472@item -qmp @var{dev} 3473@findex -qmp 3474Like -monitor but opens in 'control' mode. 3475ETEXI 3476DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3477 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3478 QEMU_ARCH_ALL) 3479STEXI 3480@item -qmp-pretty @var{dev} 3481@findex -qmp-pretty 3482Like -qmp but uses pretty JSON formatting. 3483ETEXI 3484 3485DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3486 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3487STEXI 3488@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3489@findex -mon 3490Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3491easing human reading and debugging. 3492ETEXI 3493 3494DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3495 "-debugcon dev redirect the debug console to char device 'dev'\n", 3496 QEMU_ARCH_ALL) 3497STEXI 3498@item -debugcon @var{dev} 3499@findex -debugcon 3500Redirect the debug console to host device @var{dev} (same devices as the 3501serial port). The debug console is an I/O port which is typically port 35020xe9; writing to that I/O port sends output to this device. 3503The default device is @code{vc} in graphical mode and @code{stdio} in 3504non graphical mode. 3505ETEXI 3506 3507DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3508 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3509STEXI 3510@item -pidfile @var{file} 3511@findex -pidfile 3512Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3513from a script. 3514ETEXI 3515 3516DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3517 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3518STEXI 3519@item -singlestep 3520@findex -singlestep 3521Run the emulation in single step mode. 3522ETEXI 3523 3524DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3525 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3526 QEMU_ARCH_ALL) 3527STEXI 3528@item --preconfig 3529@findex --preconfig 3530Pause QEMU for interactive configuration before the machine is created, 3531which allows querying and configuring properties that will affect 3532machine initialization. Use QMP command 'x-exit-preconfig' to exit 3533the preconfig state and move to the next state (i.e. run guest if -S 3534isn't used or pause the second time if -S is used). This option is 3535experimental. 3536ETEXI 3537 3538DEF("S", 0, QEMU_OPTION_S, \ 3539 "-S freeze CPU at startup (use 'c' to start execution)\n", 3540 QEMU_ARCH_ALL) 3541STEXI 3542@item -S 3543@findex -S 3544Do not start CPU at startup (you must type 'c' in the monitor). 3545ETEXI 3546 3547DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3548 "-realtime [mlock=on|off]\n" 3549 " run qemu with realtime features\n" 3550 " mlock=on|off controls mlock support (default: on)\n", 3551 QEMU_ARCH_ALL) 3552STEXI 3553@item -realtime mlock=on|off 3554@findex -realtime 3555Run qemu with realtime features. 3556mlocking qemu and guest memory can be enabled via @option{mlock=on} 3557(enabled by default). 3558ETEXI 3559 3560DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3561 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3562 " run qemu with overcommit hints\n" 3563 " mem-lock=on|off controls memory lock support (default: off)\n" 3564 " cpu-pm=on|off controls cpu power management (default: off)\n", 3565 QEMU_ARCH_ALL) 3566STEXI 3567@item -overcommit mem-lock=on|off 3568@item -overcommit cpu-pm=on|off 3569@findex -overcommit 3570Run qemu with hints about host resource overcommit. The default is 3571to assume that host overcommits all resources. 3572 3573Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3574by default). This works when host memory is not overcommitted and reduces the 3575worst-case latency for guest. This is equivalent to @option{realtime}. 3576 3577Guest ability to manage power state of host cpus (increasing latency for other 3578processes on the same host cpu, but decreasing latency for guest) can be 3579enabled via @option{cpu-pm=on} (disabled by default). This works best when 3580host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3581utilization will be incorrect, not taking into account guest idle time. 3582ETEXI 3583 3584DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3585 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3586STEXI 3587@item -gdb @var{dev} 3588@findex -gdb 3589Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3590connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3591stdio are reasonable use case. The latter is allowing to start QEMU from 3592within gdb and establish the connection via a pipe: 3593@example 3594(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3595@end example 3596ETEXI 3597 3598DEF("s", 0, QEMU_OPTION_s, \ 3599 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3600 QEMU_ARCH_ALL) 3601STEXI 3602@item -s 3603@findex -s 3604Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3605(@pxref{gdb_usage}). 3606ETEXI 3607 3608DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3609 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3610 QEMU_ARCH_ALL) 3611STEXI 3612@item -d @var{item1}[,...] 3613@findex -d 3614Enable logging of specified items. Use '-d help' for a list of log items. 3615ETEXI 3616 3617DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3618 "-D logfile output log to logfile (default stderr)\n", 3619 QEMU_ARCH_ALL) 3620STEXI 3621@item -D @var{logfile} 3622@findex -D 3623Output log in @var{logfile} instead of to stderr 3624ETEXI 3625 3626DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3627 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3628 QEMU_ARCH_ALL) 3629STEXI 3630@item -dfilter @var{range1}[,...] 3631@findex -dfilter 3632Filter debug output to that relevant to a range of target addresses. The filter 3633spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3634@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3635addresses and sizes required. For example: 3636@example 3637 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3638@end example 3639Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3640the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3641block starting at 0xffffffc00005f000. 3642ETEXI 3643 3644DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3645 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3646 QEMU_ARCH_ALL) 3647STEXI 3648@item -L @var{path} 3649@findex -L 3650Set the directory for the BIOS, VGA BIOS and keymaps. 3651 3652To list all the data directories, use @code{-L help}. 3653ETEXI 3654 3655DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3656 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3657STEXI 3658@item -bios @var{file} 3659@findex -bios 3660Set the filename for the BIOS. 3661ETEXI 3662 3663DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3664 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3665STEXI 3666@item -enable-kvm 3667@findex -enable-kvm 3668Enable KVM full virtualization support. This option is only available 3669if KVM support is enabled when compiling. 3670ETEXI 3671 3672DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3673 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3674DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3675 "-xen-attach attach to existing xen domain\n" 3676 " libxl will use this when starting QEMU\n", 3677 QEMU_ARCH_ALL) 3678DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3679 "-xen-domid-restrict restrict set of available xen operations\n" 3680 " to specified domain id. (Does not affect\n" 3681 " xenpv machine type).\n", 3682 QEMU_ARCH_ALL) 3683STEXI 3684@item -xen-domid @var{id} 3685@findex -xen-domid 3686Specify xen guest domain @var{id} (XEN only). 3687@item -xen-attach 3688@findex -xen-attach 3689Attach to existing xen domain. 3690libxl will use this when starting QEMU (XEN only). 3691@findex -xen-domid-restrict 3692Restrict set of available xen operations to specified domain id (XEN only). 3693ETEXI 3694 3695DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3696 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3697STEXI 3698@item -no-reboot 3699@findex -no-reboot 3700Exit instead of rebooting. 3701ETEXI 3702 3703DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3704 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3705STEXI 3706@item -no-shutdown 3707@findex -no-shutdown 3708Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3709This allows for instance switching to monitor to commit changes to the 3710disk image. 3711ETEXI 3712 3713DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3714 "-loadvm [tag|id]\n" \ 3715 " start right away with a saved state (loadvm in monitor)\n", 3716 QEMU_ARCH_ALL) 3717STEXI 3718@item -loadvm @var{file} 3719@findex -loadvm 3720Start right away with a saved state (@code{loadvm} in monitor) 3721ETEXI 3722 3723#ifndef _WIN32 3724DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3725 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3726#endif 3727STEXI 3728@item -daemonize 3729@findex -daemonize 3730Daemonize the QEMU process after initialization. QEMU will not detach from 3731standard IO until it is ready to receive connections on any of its devices. 3732This option is a useful way for external programs to launch QEMU without having 3733to cope with initialization race conditions. 3734ETEXI 3735 3736DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3737 "-option-rom rom load a file, rom, into the option ROM space\n", 3738 QEMU_ARCH_ALL) 3739STEXI 3740@item -option-rom @var{file} 3741@findex -option-rom 3742Load the contents of @var{file} as an option ROM. 3743This option is useful to load things like EtherBoot. 3744ETEXI 3745 3746DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3747 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3748 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3749 QEMU_ARCH_ALL) 3750 3751STEXI 3752 3753@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3754@findex -rtc 3755Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3756UTC or local time, respectively. @code{localtime} is required for correct date in 3757MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3758format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3759 3760By default the RTC is driven by the host system time. This allows using of the 3761RTC as accurate reference clock inside the guest, specifically if the host 3762time is smoothly following an accurate external reference clock, e.g. via NTP. 3763If you want to isolate the guest time from the host, you can set @option{clock} 3764to @code{rt} instead, which provides a host monotonic clock if host support it. 3765To even prevent the RTC from progressing during suspension, you can set @option{clock} 3766to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3767icount mode in order to preserve determinism; however, note that in icount mode 3768the speed of the virtual clock is variable and can in general differ from the 3769host clock. 3770 3771Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3772specifically with Windows' ACPI HAL. This option will try to figure out how 3773many timer interrupts were not processed by the Windows guest and will 3774re-inject them. 3775ETEXI 3776 3777DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3778 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3779 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3780 " instruction, enable aligning the host and virtual clocks\n" \ 3781 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3782STEXI 3783@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3784@findex -icount 3785Enable virtual instruction counter. The virtual cpu will execute one 3786instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3787then the virtual cpu speed will be automatically adjusted to keep virtual 3788time within a few seconds of real time. 3789 3790When the virtual cpu is sleeping, the virtual time will advance at default 3791speed unless @option{sleep=on|off} is specified. 3792With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3793instantly whenever the virtual cpu goes to sleep mode and will not advance 3794if no timer is enabled. This behavior give deterministic execution times from 3795the guest point of view. 3796 3797Note that while this option can give deterministic behavior, it does not 3798provide cycle accurate emulation. Modern CPUs contain superscalar out of 3799order cores with complex cache hierarchies. The number of instructions 3800executed often has little or no correlation with actual performance. 3801 3802@option{align=on} will activate the delay algorithm which will try 3803to synchronise the host clock and the virtual clock. The goal is to 3804have a guest running at the real frequency imposed by the shift option. 3805Whenever the guest clock is behind the host clock and if 3806@option{align=on} is specified then we print a message to the user 3807to inform about the delay. 3808Currently this option does not work when @option{shift} is @code{auto}. 3809Note: The sync algorithm will work for those shift values for which 3810the guest clock runs ahead of the host clock. Typically this happens 3811when the shift value is high (how high depends on the host machine). 3812 3813When @option{rr} option is specified deterministic record/replay is enabled. 3814Replay log is written into @var{filename} file in record mode and 3815read from this file in replay mode. 3816 3817Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3818at the start of execution recording. In replay mode this option is used 3819to load the initial VM state. 3820ETEXI 3821 3822DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3823 "-watchdog model\n" \ 3824 " enable virtual hardware watchdog [default=none]\n", 3825 QEMU_ARCH_ALL) 3826STEXI 3827@item -watchdog @var{model} 3828@findex -watchdog 3829Create a virtual hardware watchdog device. Once enabled (by a guest 3830action), the watchdog must be periodically polled by an agent inside 3831the guest or else the guest will be restarted. Choose a model for 3832which your guest has drivers. 3833 3834The @var{model} is the model of hardware watchdog to emulate. Use 3835@code{-watchdog help} to list available hardware models. Only one 3836watchdog can be enabled for a guest. 3837 3838The following models may be available: 3839@table @option 3840@item ib700 3841iBASE 700 is a very simple ISA watchdog with a single timer. 3842@item i6300esb 3843Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3844dual-timer watchdog. 3845@item diag288 3846A virtual watchdog for s390x backed by the diagnose 288 hypercall 3847(currently KVM only). 3848@end table 3849ETEXI 3850 3851DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3852 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3853 " action when watchdog fires [default=reset]\n", 3854 QEMU_ARCH_ALL) 3855STEXI 3856@item -watchdog-action @var{action} 3857@findex -watchdog-action 3858 3859The @var{action} controls what QEMU will do when the watchdog timer 3860expires. 3861The default is 3862@code{reset} (forcefully reset the guest). 3863Other possible actions are: 3864@code{shutdown} (attempt to gracefully shutdown the guest), 3865@code{poweroff} (forcefully poweroff the guest), 3866@code{inject-nmi} (inject a NMI into the guest), 3867@code{pause} (pause the guest), 3868@code{debug} (print a debug message and continue), or 3869@code{none} (do nothing). 3870 3871Note that the @code{shutdown} action requires that the guest responds 3872to ACPI signals, which it may not be able to do in the sort of 3873situations where the watchdog would have expired, and thus 3874@code{-watchdog-action shutdown} is not recommended for production use. 3875 3876Examples: 3877 3878@table @code 3879@item -watchdog i6300esb -watchdog-action pause 3880@itemx -watchdog ib700 3881@end table 3882ETEXI 3883 3884DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3885 "-echr chr set terminal escape character instead of ctrl-a\n", 3886 QEMU_ARCH_ALL) 3887STEXI 3888 3889@item -echr @var{numeric_ascii_value} 3890@findex -echr 3891Change the escape character used for switching to the monitor when using 3892monitor and serial sharing. The default is @code{0x01} when using the 3893@code{-nographic} option. @code{0x01} is equal to pressing 3894@code{Control-a}. You can select a different character from the ascii 3895control keys where 1 through 26 map to Control-a through Control-z. For 3896instance you could use the either of the following to change the escape 3897character to Control-t. 3898@table @code 3899@item -echr 0x14 3900@itemx -echr 20 3901@end table 3902ETEXI 3903 3904DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3905 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3906STEXI 3907@item -show-cursor 3908@findex -show-cursor 3909Show cursor. 3910ETEXI 3911 3912DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3913 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3914STEXI 3915@item -tb-size @var{n} 3916@findex -tb-size 3917Set TB size. 3918ETEXI 3919 3920DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3921 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3922 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3923 "-incoming unix:socketpath\n" \ 3924 " prepare for incoming migration, listen on\n" \ 3925 " specified protocol and socket address\n" \ 3926 "-incoming fd:fd\n" \ 3927 "-incoming exec:cmdline\n" \ 3928 " accept incoming migration on given file descriptor\n" \ 3929 " or from given external command\n" \ 3930 "-incoming defer\n" \ 3931 " wait for the URI to be specified via migrate_incoming\n", 3932 QEMU_ARCH_ALL) 3933STEXI 3934@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3935@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3936@findex -incoming 3937Prepare for incoming migration, listen on a given tcp port. 3938 3939@item -incoming unix:@var{socketpath} 3940Prepare for incoming migration, listen on a given unix socket. 3941 3942@item -incoming fd:@var{fd} 3943Accept incoming migration from a given filedescriptor. 3944 3945@item -incoming exec:@var{cmdline} 3946Accept incoming migration as an output from specified external command. 3947 3948@item -incoming defer 3949Wait for the URI to be specified via migrate_incoming. The monitor can 3950be used to change settings (such as migration parameters) prior to issuing 3951the migrate_incoming to allow the migration to begin. 3952ETEXI 3953 3954DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3955 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3956STEXI 3957@item -only-migratable 3958@findex -only-migratable 3959Only allow migratable devices. Devices will not be allowed to enter an 3960unmigratable state. 3961ETEXI 3962 3963DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3964 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3965STEXI 3966@item -nodefaults 3967@findex -nodefaults 3968Don't create default devices. Normally, QEMU sets the default devices like serial 3969port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3970CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3971default devices. 3972ETEXI 3973 3974#ifndef _WIN32 3975DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3976 "-chroot dir chroot to dir just before starting the VM\n", 3977 QEMU_ARCH_ALL) 3978#endif 3979STEXI 3980@item -chroot @var{dir} 3981@findex -chroot 3982Immediately before starting guest execution, chroot to the specified 3983directory. Especially useful in combination with -runas. 3984ETEXI 3985 3986#ifndef _WIN32 3987DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3988 "-runas user change to user id user just before starting the VM\n" \ 3989 " user can be numeric uid:gid instead\n", 3990 QEMU_ARCH_ALL) 3991#endif 3992STEXI 3993@item -runas @var{user} 3994@findex -runas 3995Immediately before starting guest execution, drop root privileges, switching 3996to the specified user. 3997ETEXI 3998 3999DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4000 "-prom-env variable=value\n" 4001 " set OpenBIOS nvram variables\n", 4002 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4003STEXI 4004@item -prom-env @var{variable}=@var{value} 4005@findex -prom-env 4006Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4007ETEXI 4008DEF("semihosting", 0, QEMU_OPTION_semihosting, 4009 "-semihosting semihosting mode\n", 4010 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4011 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4012STEXI 4013@item -semihosting 4014@findex -semihosting 4015Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4016ETEXI 4017DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4018 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 4019 " semihosting configuration\n", 4020QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4021QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4022STEXI 4023@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 4024@findex -semihosting-config 4025Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4026@table @option 4027@item target=@code{native|gdb|auto} 4028Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4029or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4030during debug sessions and @code{native} otherwise. 4031@item arg=@var{str1},arg=@var{str2},... 4032Allows the user to pass input arguments, and can be used multiple times to build 4033up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4034command line is still supported for backward compatibility. If both the 4035@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4036specified, the former is passed to semihosting as it always takes precedence. 4037@end table 4038ETEXI 4039DEF("old-param", 0, QEMU_OPTION_old_param, 4040 "-old-param old param mode\n", QEMU_ARCH_ARM) 4041STEXI 4042@item -old-param 4043@findex -old-param (ARM) 4044Old param mode (ARM only). 4045ETEXI 4046 4047DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4048 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4049 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4050 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4051 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4052 " by the kernel, but typically no longer used by modern\n" \ 4053 " C library implementations.\n" \ 4054 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4055 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4056 " The value 'children' will deny set*uid|gid system calls for\n" \ 4057 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4058 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4059 " blacklisting *fork and execve\n" \ 4060 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4061 QEMU_ARCH_ALL) 4062STEXI 4063@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4064@findex -sandbox 4065Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4066disable it. The default is 'off'. 4067@table @option 4068@item obsolete=@var{string} 4069Enable Obsolete system calls 4070@item elevateprivileges=@var{string} 4071Disable set*uid|gid system calls 4072@item spawn=@var{string} 4073Disable *fork and execve 4074@item resourcecontrol=@var{string} 4075Disable process affinity and schedular priority 4076@end table 4077ETEXI 4078 4079DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4080 "-readconfig <file>\n", QEMU_ARCH_ALL) 4081STEXI 4082@item -readconfig @var{file} 4083@findex -readconfig 4084Read device configuration from @var{file}. This approach is useful when you want to spawn 4085QEMU process with many command line options but you don't want to exceed the command line 4086character limit. 4087ETEXI 4088DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4089 "-writeconfig <file>\n" 4090 " read/write config file\n", QEMU_ARCH_ALL) 4091STEXI 4092@item -writeconfig @var{file} 4093@findex -writeconfig 4094Write device configuration to @var{file}. The @var{file} can be either filename to save 4095command line and device configuration into file or dash @code{-}) character to print the 4096output to stdout. This can be later used as input file for @code{-readconfig} option. 4097ETEXI 4098 4099DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4100 "-no-user-config\n" 4101 " do not load default user-provided config files at startup\n", 4102 QEMU_ARCH_ALL) 4103STEXI 4104@item -no-user-config 4105@findex -no-user-config 4106The @code{-no-user-config} option makes QEMU not load any of the user-provided 4107config files on @var{sysconfdir}. 4108ETEXI 4109 4110DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4111 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4112 " specify tracing options\n", 4113 QEMU_ARCH_ALL) 4114STEXI 4115HXCOMM This line is not accurate, as some sub-options are backend-specific but 4116HXCOMM HX does not support conditional compilation of text. 4117@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4118@findex -trace 4119@include qemu-option-trace.texi 4120ETEXI 4121 4122HXCOMM Internal use 4123DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4124DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4125 4126#ifdef __linux__ 4127DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4128 "-enable-fips enable FIPS 140-2 compliance\n", 4129 QEMU_ARCH_ALL) 4130#endif 4131STEXI 4132@item -enable-fips 4133@findex -enable-fips 4134Enable FIPS 140-2 compliance mode. 4135ETEXI 4136 4137HXCOMM Deprecated by -machine accel=tcg property 4138DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4139 4140DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4141 "-msg timestamp[=on|off]\n" 4142 " change the format of messages\n" 4143 " on|off controls leading timestamps (default:on)\n", 4144 QEMU_ARCH_ALL) 4145STEXI 4146@item -msg timestamp[=on|off] 4147@findex -msg 4148prepend a timestamp to each log message.(default:on) 4149ETEXI 4150 4151DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4152 "-dump-vmstate <file>\n" 4153 " Output vmstate information in JSON format to file.\n" 4154 " Use the scripts/vmstate-static-checker.py file to\n" 4155 " check for possible regressions in migration code\n" 4156 " by comparing two such vmstate dumps.\n", 4157 QEMU_ARCH_ALL) 4158STEXI 4159@item -dump-vmstate @var{file} 4160@findex -dump-vmstate 4161Dump json-encoded vmstate information for current machine type to file 4162in @var{file} 4163ETEXI 4164 4165DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4166 "-enable-sync-profile\n" 4167 " enable synchronization profiling\n", 4168 QEMU_ARCH_ALL) 4169STEXI 4170@item -enable-sync-profile 4171@findex -enable-sync-profile 4172Enable synchronization profiling. 4173ETEXI 4174 4175STEXI 4176@end table 4177ETEXI 4178DEFHEADING() 4179 4180DEFHEADING(Generic object creation:) 4181STEXI 4182@table @option 4183ETEXI 4184 4185DEF("object", HAS_ARG, QEMU_OPTION_object, 4186 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4187 " create a new object of type TYPENAME setting properties\n" 4188 " in the order they are specified. Note that the 'id'\n" 4189 " property must be set. These objects are placed in the\n" 4190 " '/objects' path.\n", 4191 QEMU_ARCH_ALL) 4192STEXI 4193@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4194@findex -object 4195Create a new object of type @var{typename} setting properties 4196in the order they are specified. Note that the 'id' 4197property must be set. These objects are placed in the 4198'/objects' path. 4199 4200@table @option 4201 4202@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} 4203 4204Creates a memory file backend object, which can be used to back 4205the guest RAM with huge pages. 4206 4207The @option{id} parameter is a unique ID that will be used to reference this 4208memory region when configuring the @option{-numa} argument. 4209 4210The @option{size} option provides the size of the memory region, and accepts 4211common suffixes, eg @option{500M}. 4212 4213The @option{mem-path} provides the path to either a shared memory or huge page 4214filesystem mount. 4215 4216The @option{share} boolean option determines whether the memory 4217region is marked as private to QEMU, or shared. The latter allows 4218a co-operating external process to access the QEMU memory region. 4219 4220The @option{share} is also required for pvrdma devices due to 4221limitations in the RDMA API provided by Linux. 4222 4223Setting share=on might affect the ability to configure NUMA 4224bindings for the memory backend under some circumstances, see 4225Documentation/vm/numa_memory_policy.txt on the Linux kernel 4226source tree for additional details. 4227 4228Setting the @option{discard-data} boolean option to @var{on} 4229indicates that file contents can be destroyed when QEMU exits, 4230to avoid unnecessarily flushing data to the backing file. Note 4231that @option{discard-data} is only an optimization, and QEMU 4232might not discard file contents if it aborts unexpectedly or is 4233terminated using SIGKILL. 4234 4235The @option{merge} boolean option enables memory merge, also known as 4236MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4237memory deduplication. 4238 4239Setting the @option{dump} boolean option to @var{off} excludes the memory from 4240core dumps. This feature is also known as MADV_DONTDUMP. 4241 4242The @option{prealloc} boolean option enables memory preallocation. 4243 4244The @option{host-nodes} option binds the memory range to a list of NUMA host 4245nodes. 4246 4247The @option{policy} option sets the NUMA policy to one of the following values: 4248 4249@table @option 4250@item @var{default} 4251default host policy 4252 4253@item @var{preferred} 4254prefer the given host node list for allocation 4255 4256@item @var{bind} 4257restrict memory allocation to the given host node list 4258 4259@item @var{interleave} 4260interleave memory allocations across the given host node list 4261@end table 4262 4263The @option{align} option specifies the base address alignment when 4264QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4265@option{2M}. Some backend store specified by @option{mem-path} 4266requires an alignment different than the default one used by QEMU, eg 4267the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4268such cases, users can specify the required alignment via this option. 4269 4270The @option{pmem} option specifies whether the backing file specified 4271by @option{mem-path} is in host persistent memory that can be accessed 4272using the SNIA NVM programming model (e.g. Intel NVDIMM). 4273If @option{pmem} is set to 'on', QEMU will take necessary operations to 4274guarantee the persistence of its own writes to @option{mem-path} 4275(e.g. in vNVDIMM label emulation and live migration). 4276Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4277file metadata is in sync for @option{mem-path} in case of host crash 4278or a power failure. MAP_SYNC requires support from both the host kernel 4279(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4280with DAX option. 4281 4282@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} 4283 4284Creates a memory backend object, which can be used to back the guest RAM. 4285Memory backend objects offer more control than the @option{-m} option that is 4286traditionally used to define guest RAM. Please refer to 4287@option{memory-backend-file} for a description of the options. 4288 4289@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} 4290 4291Creates an anonymous memory file backend object, which allows QEMU to 4292share the memory with an external process (e.g. when using 4293vhost-user). The memory is allocated with memfd and optional 4294sealing. (Linux only) 4295 4296The @option{seal} option creates a sealed-file, that will block 4297further resizing the memory ('on' by default). 4298 4299The @option{hugetlb} option specify the file to be created resides in 4300the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4301the @option{hugetlb} option, the @option{hugetlbsize} option specify 4302the hugetlb page size on systems that support multiple hugetlb page 4303sizes (it must be a power of 2 value supported by the system). 4304 4305In some versions of Linux, the @option{hugetlb} option is incompatible 4306with the @option{seal} option (requires at least Linux 4.16). 4307 4308Please refer to @option{memory-backend-file} for a description of the 4309other options. 4310 4311The @option{share} boolean option is @var{on} by default with memfd. 4312 4313@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4314 4315Creates a random number generator backend which obtains entropy from 4316a device on the host. The @option{id} parameter is a unique ID that 4317will be used to reference this entropy backend from the @option{virtio-rng} 4318device. The @option{filename} parameter specifies which file to obtain 4319entropy from and if omitted defaults to @option{/dev/random}. 4320 4321@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4322 4323Creates a random number generator backend which obtains entropy from 4324an external daemon running on the host. The @option{id} parameter is 4325a unique ID that will be used to reference this entropy backend from 4326the @option{virtio-rng} device. The @option{chardev} parameter is 4327the unique ID of a character device backend that provides the connection 4328to the RNG daemon. 4329 4330@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4331 4332Creates a TLS anonymous credentials object, which can be used to provide 4333TLS support on network backends. The @option{id} parameter is a unique 4334ID which network backends will use to access the credentials. The 4335@option{endpoint} is either @option{server} or @option{client} depending 4336on whether the QEMU network backend that uses the credentials will be 4337acting as a client or as a server. If @option{verify-peer} is enabled 4338(the default) then once the handshake is completed, the peer credentials 4339will be verified, though this is a no-op for anonymous credentials. 4340 4341The @var{dir} parameter tells QEMU where to find the credential 4342files. For server endpoints, this directory may contain a file 4343@var{dh-params.pem} providing diffie-hellman parameters to use 4344for the TLS server. If the file is missing, QEMU will generate 4345a set of DH parameters at startup. This is a computationally 4346expensive operation that consumes random pool entropy, so it is 4347recommended that a persistent set of parameters be generated 4348upfront and saved. 4349 4350@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4351 4352Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4353TLS support on network backends. The @option{id} parameter is a unique 4354ID which network backends will use to access the credentials. The 4355@option{endpoint} is either @option{server} or @option{client} depending 4356on whether the QEMU network backend that uses the credentials will be 4357acting as a client or as a server. For clients only, @option{username} 4358is the username which will be sent to the server. If omitted 4359it defaults to ``qemu''. 4360 4361The @var{dir} parameter tells QEMU where to find the keys file. 4362It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4363pairs. This file can most easily be created using the GnuTLS 4364@code{psktool} program. 4365 4366For server endpoints, @var{dir} may also contain a file 4367@var{dh-params.pem} providing diffie-hellman parameters to use 4368for the TLS server. If the file is missing, QEMU will generate 4369a set of DH parameters at startup. This is a computationally 4370expensive operation that consumes random pool entropy, so it is 4371recommended that a persistent set of parameters be generated 4372up front and saved. 4373 4374@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} 4375 4376Creates a TLS anonymous credentials object, which can be used to provide 4377TLS support on network backends. The @option{id} parameter is a unique 4378ID which network backends will use to access the credentials. The 4379@option{endpoint} is either @option{server} or @option{client} depending 4380on whether the QEMU network backend that uses the credentials will be 4381acting as a client or as a server. If @option{verify-peer} is enabled 4382(the default) then once the handshake is completed, the peer credentials 4383will be verified. With x509 certificates, this implies that the clients 4384must be provided with valid client certificates too. 4385 4386The @var{dir} parameter tells QEMU where to find the credential 4387files. For server endpoints, this directory may contain a file 4388@var{dh-params.pem} providing diffie-hellman parameters to use 4389for the TLS server. If the file is missing, QEMU will generate 4390a set of DH parameters at startup. This is a computationally 4391expensive operation that consumes random pool entropy, so it is 4392recommended that a persistent set of parameters be generated 4393upfront and saved. 4394 4395For x509 certificate credentials the directory will contain further files 4396providing the x509 certificates. The certificates must be stored 4397in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4398@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4399@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4400 4401For the @var{server-key.pem} and @var{client-key.pem} files which 4402contain sensitive private keys, it is possible to use an encrypted 4403version by providing the @var{passwordid} parameter. This provides 4404the ID of a previously created @code{secret} object containing the 4405password for decryption. 4406 4407The @var{priority} parameter allows to override the global default 4408priority used by gnutls. This can be useful if the system administrator 4409needs to use a weaker set of crypto priorities for QEMU without 4410potentially forcing the weakness onto all applications. Or conversely 4411if one wants wants a stronger default for QEMU than for all other 4412applications, they can do this through this parameter. Its format is 4413a gnutls priority string as described at 4414@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4415 4416@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4417 4418Interval @var{t} can't be 0, this filter batches the packet delivery: all 4419packets arriving in a given interval on netdev @var{netdevid} are delayed 4420until the end of the interval. Interval is in microseconds. 4421@option{status} is optional that indicate whether the netfilter is 4422on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4423 4424queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4425 4426@option{all}: the filter is attached both to the receive and the transmit 4427 queue of the netdev (default). 4428 4429@option{rx}: the filter is attached to the receive queue of the netdev, 4430 where it will receive packets sent to the netdev. 4431 4432@option{tx}: the filter is attached to the transmit queue of the netdev, 4433 where it will receive packets sent by the netdev. 4434 4435@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4436 4437filter-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. 4438 4439@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4440 4441filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4442@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4443filter-redirector will redirect packet with vnet_hdr_len. 4444Create a filter-redirector we need to differ outdev id from indev id, id can not 4445be the same. we can just use indev or outdev, but at least one of indev or outdev 4446need to be specified. 4447 4448@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4449 4450Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4451secondary from primary to keep secondary tcp connection,and rewrite 4452tcp packet to primary from secondary make tcp packet can be handled by 4453client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4454 4455usage: 4456colo secondary: 4457-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4458-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4459-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4460 4461@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4462 4463Dump the network traffic on netdev @var{dev} to the file specified by 4464@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4465The file format is libpcap, so it can be analyzed with tools such as tcpdump 4466or Wireshark. 4467 4468@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid},iothread=@var{id}[,vnet_hdr_support] 4469 4470Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4471secondary packet. If the packets are same, we will output primary 4472packet to outdev@var{chardevid}, else we will notify colo-frame 4473do checkpoint and send primary packet to outdev@var{chardevid}. 4474In order to improve efficiency, we need to put the task of comparison 4475in another thread. If it has the vnet_hdr_support flag, colo compare 4476will send/recv packet with vnet_hdr_len. 4477 4478we must use it with the help of filter-mirror and filter-redirector. 4479 4480@example 4481 4482primary: 4483-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4484-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4485-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4486-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4487-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4488-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4489-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4490-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4491-object iothread,id=iothread1 4492-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4493-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4494-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4495-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4496 4497secondary: 4498-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4499-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4500-chardev socket,id=red0,host=3.3.3.3,port=9003 4501-chardev socket,id=red1,host=3.3.3.3,port=9004 4502-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4503-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4504 4505@end example 4506 4507If you want to know the detail of above command line, you can read 4508the colo-compare git log. 4509 4510@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4511 4512Creates a cryptodev backend which executes crypto opreation from 4513the QEMU cipher APIS. The @var{id} parameter is 4514a unique ID that will be used to reference this cryptodev backend from 4515the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4516which specify the queue number of cryptodev backend, the default of 4517@var{queues} is 1. 4518 4519@example 4520 4521 # qemu-system-x86_64 \ 4522 [...] \ 4523 -object cryptodev-backend-builtin,id=cryptodev0 \ 4524 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4525 [...] 4526@end example 4527 4528@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4529 4530Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4531The @var{id} parameter is a unique ID that will be used to reference this 4532cryptodev backend from the @option{virtio-crypto} device. 4533The chardev should be a unix domain socket backed one. The vhost-user uses 4534a specifically defined protocol to pass vhost ioctl replacement messages 4535to an application on the other end of the socket. 4536The @var{queues} parameter is optional, which specify the queue number 4537of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4538 4539@example 4540 4541 # qemu-system-x86_64 \ 4542 [...] \ 4543 -chardev socket,id=chardev0,path=/path/to/socket \ 4544 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4545 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4546 [...] 4547@end example 4548 4549@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4550@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4551 4552Defines a secret to store a password, encryption key, or some other sensitive 4553data. The sensitive data can either be passed directly via the @var{data} 4554parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4555parameter is insecure unless the sensitive data is encrypted. 4556 4557The sensitive data can be provided in raw format (the default), or base64. 4558When encoded as JSON, the raw format only supports valid UTF-8 characters, 4559so base64 is recommended for sending binary data. QEMU will convert from 4560which ever format is provided to the format it needs internally. eg, an 4561RBD password can be provided in raw format, even though it will be base64 4562encoded when passed onto the RBD sever. 4563 4564For added protection, it is possible to encrypt the data associated with 4565a secret using the AES-256-CBC cipher. Use of encryption is indicated 4566by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4567parameter provides the ID of a previously defined secret that contains 4568the AES-256 decryption key. This key should be 32-bytes long and be 4569base64 encoded. The @var{iv} parameter provides the random initialization 4570vector used for encryption of this particular secret and should be a 4571base64 encrypted string of the 16-byte IV. 4572 4573The simplest (insecure) usage is to provide the secret inline 4574 4575@example 4576 4577 # $QEMU -object secret,id=sec0,data=letmein,format=raw 4578 4579@end example 4580 4581The simplest secure usage is to provide the secret via a file 4582 4583 # printf "letmein" > mypasswd.txt 4584 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 4585 4586For greater security, AES-256-CBC should be used. To illustrate usage, 4587consider the openssl command line tool which can encrypt the data. Note 4588that when encrypting, the plaintext must be padded to the cipher block 4589size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4590 4591First a master key needs to be created in base64 encoding: 4592 4593@example 4594 # openssl rand -base64 32 > key.b64 4595 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4596@end example 4597 4598Each secret to be encrypted needs to have a random initialization vector 4599generated. These do not need to be kept secret 4600 4601@example 4602 # openssl rand -base64 16 > iv.b64 4603 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4604@end example 4605 4606The secret to be defined can now be encrypted, in this case we're 4607telling openssl to base64 encode the result, but it could be left 4608as raw bytes if desired. 4609 4610@example 4611 # SECRET=$(printf "letmein" | 4612 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4613@end example 4614 4615When launching QEMU, create a master secret pointing to @code{key.b64} 4616and specify that to be used to decrypt the user password. Pass the 4617contents of @code{iv.b64} to the second secret 4618 4619@example 4620 # $QEMU \ 4621 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4622 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4623 data=$SECRET,iv=$(<iv.b64) 4624@end example 4625 4626@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}] 4627 4628Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4629to provide the guest memory encryption support on AMD processors. 4630 4631When memory encryption is enabled, one of the physical address bit (aka the 4632C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4633is used to provide the C-bit position. The C-bit position is Host family dependent 4634hence user must provide this value. On EPYC, the value should be 47. 4635 4636When memory encryption is enabled, we loose certain bits in physical address space. 4637The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4638physical address space. Similar to C-bit, the value is Host family dependent. 4639On EPYC, the value should be 5. 4640 4641The @option{sev-device} provides the device file to use for communicating with 4642the SEV firmware running inside AMD Secure Processor. The default device is 4643'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4644created by CCP driver. 4645 4646The @option{policy} provides the guest policy to be enforced by the SEV firmware 4647and restrict what configuration and operational commands can be performed on this 4648guest by the hypervisor. The policy should be provided by the guest owner and is 4649bound to the guest and cannot be changed throughout the lifetime of the guest. 4650The default is 0. 4651 4652If guest @option{policy} allows sharing the key with another SEV guest then 4653@option{handle} can be use to provide handle of the guest from which to share 4654the key. 4655 4656The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4657Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4658are used for establishing a cryptographic session with the guest owner to 4659negotiate keys used for attestation. The file must be encoded in base64. 4660 4661e.g to launch a SEV guest 4662@example 4663 # $QEMU \ 4664 ...... 4665 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4666 -machine ...,memory-encryption=sev0 4667 ..... 4668 4669@end example 4670 4671 4672@item -object authz-simple,id=@var{id},identity=@var{string} 4673 4674Create an authorization object that will control access to network services. 4675 4676The @option{identity} parameter is identifies the user and its format 4677depends on the network service that authorization object is associated 4678with. For authorizing based on TLS x509 certificates, the identity must 4679be the x509 distinguished name. Note that care must be taken to escape 4680any commas in the distinguished name. 4681 4682An example authorization object to validate a x509 distinguished name 4683would look like: 4684@example 4685 # $QEMU \ 4686 ... 4687 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4688 ... 4689@end example 4690 4691Note the use of quotes due to the x509 distinguished name containing 4692whitespace, and escaping of ','. 4693 4694@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4695 4696Create an authorization object that will control access to network services. 4697 4698The @option{filename} parameter is the fully qualified path to a file 4699containing the access control list rules in JSON format. 4700 4701An example set of rules that match against SASL usernames might look 4702like: 4703 4704@example 4705 @{ 4706 "rules": [ 4707 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4708 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4709 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4710 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4711 ], 4712 "policy": "deny" 4713 @} 4714@end example 4715 4716When checking access the object will iterate over all the rules and 4717the first rule to match will have its @option{policy} value returned 4718as the result. If no rules match, then the default @option{policy} 4719value is returned. 4720 4721The rules can either be an exact string match, or they can use the 4722simple UNIX glob pattern matching to allow wildcards to be used. 4723 4724If @option{refresh} is set to true the file will be monitored 4725and automatically reloaded whenever its content changes. 4726 4727As with the @code{authz-simple} object, the format of the identity 4728strings being matched depends on the network service, but is usually 4729a TLS x509 distinguished name, or a SASL username. 4730 4731An example authorization object to validate a SASL username 4732would look like: 4733@example 4734 # $QEMU \ 4735 ... 4736 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4737 ... 4738@end example 4739 4740@item -object authz-pam,id=@var{id},service=@var{string} 4741 4742Create an authorization object that will control access to network services. 4743 4744The @option{service} parameter provides the name of a PAM service to use 4745for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4746exist to provide the configuration for the @code{account} subsystem. 4747 4748An example authorization object to validate a TLS x509 distinguished 4749name would look like: 4750 4751@example 4752 # $QEMU \ 4753 ... 4754 -object authz-pam,id=auth0,service=qemu-vnc 4755 ... 4756@end example 4757 4758There would then be a corresponding config file for PAM at 4759@code{/etc/pam.d/qemu-vnc} that contains: 4760 4761@example 4762account requisite pam_listfile.so item=user sense=allow \ 4763 file=/etc/qemu/vnc.allow 4764@end example 4765 4766Finally the @code{/etc/qemu/vnc.allow} file would contain 4767the list of x509 distingished names that are permitted 4768access 4769 4770@example 4771CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4772@end example 4773 4774 4775@end table 4776 4777ETEXI 4778 4779 4780HXCOMM This is the last statement. Insert new options before this line! 4781STEXI 4782@end table 4783ETEXI 4784
