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[,prop[=value][,...]]\n" 122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 123 " tb-size=n (TCG translation block cache size)\n" 124 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 125STEXI 126@item -accel @var{name}[,prop=@var{value}[,...]] 127@findex -accel 128This is used to enable an accelerator. Depending on the target architecture, 129kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 130more than one accelerator specified, the next one is used if the previous one 131fails to initialize. 132@table @option 133@item tb-size=@var{n} 134Controls the size (in MiB) of the TCG translation block cache. 135@item thread=single|multi 136Controls number of TCG threads. When the TCG is multi-threaded there will be one 137thread per vCPU therefor taking advantage of additional host cores. The default 138is to enable multi-threading where both the back-end and front-ends support it and 139no incompatible TCG features have been enabled (e.g. icount/replay). 140@end table 141ETEXI 142 143DEF("smp", HAS_ARG, QEMU_OPTION_smp, 144 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n" 145 " set the number of CPUs to 'n' [default=1]\n" 146 " maxcpus= maximum number of total cpus, including\n" 147 " offline CPUs for hotplug, etc\n" 148 " cores= number of CPU cores on one socket (for PC, it's on one die)\n" 149 " threads= number of threads on one CPU core\n" 150 " dies= number of CPU dies on one socket (for PC only)\n" 151 " sockets= number of discrete sockets in the system\n", 152 QEMU_ARCH_ALL) 153STEXI 154@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,dies=dies][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 155@findex -smp 156Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 157CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 158to 4. 159For the PC target, the number of @var{cores} per die, the number of @var{threads} 160per cores, the number of @var{dies} per packages and the total number of 161@var{sockets} can be specified. Missing values will be computed. 162If any on the three values is given, the total number of CPUs @var{n} can be omitted. 163@var{maxcpus} specifies the maximum number of hotpluggable CPUs. 164ETEXI 165 166DEF("numa", HAS_ARG, QEMU_OPTION_numa, 167 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 168 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 169 "-numa dist,src=source,dst=destination,val=distance\n" 170 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n", 171 QEMU_ARCH_ALL) 172STEXI 173@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 174@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 175@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 176@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 177@findex -numa 178Define a NUMA node and assign RAM and VCPUs to it. 179Set the NUMA distance from a source node to a destination node. 180 181Legacy VCPU assignment uses @samp{cpus} option where 182@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 183@samp{cpus} option represent a contiguous range of CPU indexes 184(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 185set of VCPUs can be represented by providing multiple @samp{cpus} 186options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 187split between them. 188 189For example, the following option assigns VCPUs 0, 1, 2 and 5 to 190a NUMA node: 191@example 192-numa node,cpus=0-2,cpus=5 193@end example 194 195@samp{cpu} option is a new alternative to @samp{cpus} option 196which uses @samp{socket-id|core-id|thread-id} properties to assign 197CPU objects to a @var{node} using topology layout properties of CPU. 198The set of properties is machine specific, and depends on used 199machine type/@samp{smp} options. It could be queried with 200@samp{hotpluggable-cpus} monitor command. 201@samp{node-id} property specifies @var{node} to which CPU object 202will be assigned, it's required for @var{node} to be declared 203with @samp{node} option before it's used with @samp{cpu} option. 204 205For example: 206@example 207-M pc \ 208-smp 1,sockets=2,maxcpus=2 \ 209-numa node,nodeid=0 -numa node,nodeid=1 \ 210-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 211@end example 212 213@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 214assigns RAM from a given memory backend device to a node. If 215@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 216split equally between them. 217 218@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 219if one node uses @samp{memdev}, all of them have to use it. 220 221@var{source} and @var{destination} are NUMA node IDs. 222@var{distance} is the NUMA distance from @var{source} to @var{destination}. 223The distance from a node to itself is always 10. If any pair of nodes is 224given a distance, then all pairs must be given distances. Although, when 225distances are only given in one direction for each pair of nodes, then 226the distances in the opposite directions are assumed to be the same. If, 227however, an asymmetrical pair of distances is given for even one node 228pair, then all node pairs must be provided distance values for both 229directions, even when they are symmetrical. When a node is unreachable 230from another node, set the pair's distance to 255. 231 232Note that the -@option{numa} option doesn't allocate any of the 233specified resources, it just assigns existing resources to NUMA 234nodes. This means that one still has to use the @option{-m}, 235@option{-smp} options to allocate RAM and VCPUs respectively. 236 237ETEXI 238 239DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 240 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 241 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 242STEXI 243@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 244@findex -add-fd 245 246Add a file descriptor to an fd set. Valid options are: 247 248@table @option 249@item fd=@var{fd} 250This option defines the file descriptor of which a duplicate is added to fd set. 251The file descriptor cannot be stdin, stdout, or stderr. 252@item set=@var{set} 253This option defines the ID of the fd set to add the file descriptor to. 254@item opaque=@var{opaque} 255This option defines a free-form string that can be used to describe @var{fd}. 256@end table 257 258You can open an image using pre-opened file descriptors from an fd set: 259@example 260@value{qemu_system} \ 261 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 262 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 263 -drive file=/dev/fdset/2,index=0,media=disk 264@end example 265ETEXI 266 267DEF("set", HAS_ARG, QEMU_OPTION_set, 268 "-set group.id.arg=value\n" 269 " set <arg> parameter for item <id> of type <group>\n" 270 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 271STEXI 272@item -set @var{group}.@var{id}.@var{arg}=@var{value} 273@findex -set 274Set parameter @var{arg} for item @var{id} of type @var{group} 275ETEXI 276 277DEF("global", HAS_ARG, QEMU_OPTION_global, 278 "-global driver.property=value\n" 279 "-global driver=driver,property=property,value=value\n" 280 " set a global default for a driver property\n", 281 QEMU_ARCH_ALL) 282STEXI 283@item -global @var{driver}.@var{prop}=@var{value} 284@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 285@findex -global 286Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 287 288@example 289@value{qemu_system_x86} -global ide-hd.physical_block_size=4096 disk-image.img 290@end example 291 292In particular, you can use this to set driver properties for devices which are 293created automatically by the machine model. To create a device which is not 294created automatically and set properties on it, use -@option{device}. 295 296-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 297driver=@var{driver},property=@var{prop},value=@var{value}. The 298longhand syntax works even when @var{driver} contains a dot. 299ETEXI 300 301DEF("boot", HAS_ARG, QEMU_OPTION_boot, 302 "-boot [order=drives][,once=drives][,menu=on|off]\n" 303 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 304 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 305 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 306 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 307 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 308 QEMU_ARCH_ALL) 309STEXI 310@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] 311@findex -boot 312Specify boot order @var{drives} as a string of drive letters. Valid 313drive letters depend on the target architecture. The x86 PC uses: a, b 314(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 315from network adapter 1-4), hard disk boot is the default. To apply a 316particular boot order only on the first startup, specify it via 317@option{once}. Note that the @option{order} or @option{once} parameter 318should not be used together with the @option{bootindex} property of 319devices, since the firmware implementations normally do not support both 320at the same time. 321 322Interactive boot menus/prompts can be enabled via @option{menu=on} as far 323as firmware/BIOS supports them. The default is non-interactive boot. 324 325A splash picture could be passed to bios, enabling user to show it as logo, 326when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 327supports them. Currently Seabios for X86 system support it. 328limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 329format(true color). The resolution should be supported by the SVGA mode, so 330the recommended is 320x240, 640x480, 800x640. 331 332A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 333when boot failed, then reboot. If @option{reboot-timeout} is not set, 334guest will not reboot by default. Currently Seabios for X86 335system support it. 336 337Do strict boot via @option{strict=on} as far as firmware/BIOS 338supports it. This only effects when boot priority is changed by 339bootindex options. The default is non-strict boot. 340 341@example 342# try to boot from network first, then from hard disk 343@value{qemu_system_x86} -boot order=nc 344# boot from CD-ROM first, switch back to default order after reboot 345@value{qemu_system_x86} -boot once=d 346# boot with a splash picture for 5 seconds. 347@value{qemu_system_x86} -boot menu=on,splash=/root/boot.bmp,splash-time=5000 348@end example 349 350Note: The legacy format '-boot @var{drives}' is still supported but its 351use is discouraged as it may be removed from future versions. 352ETEXI 353 354DEF("m", HAS_ARG, QEMU_OPTION_m, 355 "-m [size=]megs[,slots=n,maxmem=size]\n" 356 " configure guest RAM\n" 357 " size: initial amount of guest memory\n" 358 " slots: number of hotplug slots (default: none)\n" 359 " maxmem: maximum amount of guest memory (default: none)\n" 360 "NOTE: Some architectures might enforce a specific granularity\n", 361 QEMU_ARCH_ALL) 362STEXI 363@item -m [size=]@var{megs}[,slots=n,maxmem=size] 364@findex -m 365Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 366Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 367megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 368could be used to set amount of hotpluggable memory slots and maximum amount of 369memory. Note that @var{maxmem} must be aligned to the page size. 370 371For example, the following command-line sets the guest startup RAM size to 3721GB, creates 3 slots to hotplug additional memory and sets the maximum 373memory the guest can reach to 4GB: 374 375@example 376@value{qemu_system} -m 1G,slots=3,maxmem=4G 377@end example 378 379If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 380be enabled and the guest startup RAM will never increase. 381ETEXI 382 383DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 384 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 385STEXI 386@item -mem-path @var{path} 387@findex -mem-path 388Allocate guest RAM from a temporarily created file in @var{path}. 389ETEXI 390 391DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 392 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 393 QEMU_ARCH_ALL) 394STEXI 395@item -mem-prealloc 396@findex -mem-prealloc 397Preallocate memory when using -mem-path. 398ETEXI 399 400DEF("k", HAS_ARG, QEMU_OPTION_k, 401 "-k language use keyboard layout (for example 'fr' for French)\n", 402 QEMU_ARCH_ALL) 403STEXI 404@item -k @var{language} 405@findex -k 406Use keyboard layout @var{language} (for example @code{fr} for 407French). This option is only needed where it is not easy to get raw PC 408keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 409display). You don't normally need to use it on PC/Linux or PC/Windows 410hosts. 411 412The available layouts are: 413@example 414ar de-ch es fo fr-ca hu ja mk no pt-br sv 415da en-gb et fr fr-ch is lt nl pl ru th 416de en-us fi fr-be hr it lv nl-be pt sl tr 417@end example 418 419The default is @code{en-us}. 420ETEXI 421 422 423HXCOMM Deprecated by -audiodev 424DEF("audio-help", 0, QEMU_OPTION_audio_help, 425 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 426 QEMU_ARCH_ALL) 427STEXI 428@item -audio-help 429@findex -audio-help 430Will show the -audiodev equivalent of the currently specified 431(deprecated) environment variables. 432ETEXI 433 434DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 435 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 436 " specifies the audio backend to use\n" 437 " id= identifier of the backend\n" 438 " timer-period= timer period in microseconds\n" 439 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 440 " in|out.fixed-settings= use fixed settings for host audio\n" 441 " in|out.frequency= frequency to use with fixed settings\n" 442 " in|out.channels= number of channels to use with fixed settings\n" 443 " in|out.format= sample format to use with fixed settings\n" 444 " valid values: s8, s16, s32, u8, u16, u32\n" 445 " in|out.voices= number of voices to use\n" 446 " in|out.buffer-length= length of buffer in microseconds\n" 447 "-audiodev none,id=id,[,prop[=value][,...]]\n" 448 " dummy driver that discards all output\n" 449#ifdef CONFIG_AUDIO_ALSA 450 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 451 " in|out.dev= name of the audio device to use\n" 452 " in|out.period-length= length of period in microseconds\n" 453 " in|out.try-poll= attempt to use poll mode\n" 454 " threshold= threshold (in microseconds) when playback starts\n" 455#endif 456#ifdef CONFIG_AUDIO_COREAUDIO 457 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 458 " in|out.buffer-count= number of buffers\n" 459#endif 460#ifdef CONFIG_AUDIO_DSOUND 461 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 462 " latency= add extra latency to playback in microseconds\n" 463#endif 464#ifdef CONFIG_AUDIO_OSS 465 "-audiodev oss,id=id[,prop[=value][,...]]\n" 466 " in|out.dev= path of the audio device to use\n" 467 " in|out.buffer-count= number of buffers\n" 468 " in|out.try-poll= attempt to use poll mode\n" 469 " try-mmap= try using memory mapped access\n" 470 " exclusive= open device in exclusive mode\n" 471 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 472#endif 473#ifdef CONFIG_AUDIO_PA 474 "-audiodev pa,id=id[,prop[=value][,...]]\n" 475 " server= PulseAudio server address\n" 476 " in|out.name= source/sink device name\n" 477 " in|out.latency= desired latency in microseconds\n" 478#endif 479#ifdef CONFIG_AUDIO_SDL 480 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 481#endif 482#ifdef CONFIG_SPICE 483 "-audiodev spice,id=id[,prop[=value][,...]]\n" 484#endif 485 "-audiodev wav,id=id[,prop[=value][,...]]\n" 486 " path= path of wav file to record\n", 487 QEMU_ARCH_ALL) 488STEXI 489@item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]] 490@findex -audiodev 491Adds a new audio backend @var{driver} identified by @var{id}. There are 492global and driver specific properties. Some values can be set 493differently for input and output, they're marked with @code{in|out.}. 494You can set the input's property with @code{in.@var{prop}} and the 495output's property with @code{out.@var{prop}}. For example: 496@example 497-audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 498-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 499@end example 500 501NOTE: parameter validation is known to be incomplete, in many cases 502specifying an invalid option causes QEMU to print an error message and 503continue emulation without sound. 504 505Valid global options are: 506 507@table @option 508@item id=@var{identifier} 509Identifies the audio backend. 510 511@item timer-period=@var{period} 512Sets the timer @var{period} used by the audio subsystem in microseconds. 513Default is 10000 (10 ms). 514 515@item in|out.mixing-engine=on|off 516Use QEMU's mixing engine to mix all streams inside QEMU and convert 517audio formats when not supported by the backend. When off, 518@var{fixed-settings} must be off too. Note that disabling this option 519means that the selected backend must support multiple streams and the 520audio formats used by the virtual cards, otherwise you'll get no sound. 521It's not recommended to disable this option unless you want to use 5.1 522or 7.1 audio, as mixing engine only supports mono and stereo audio. 523Default is on. 524 525@item in|out.fixed-settings=on|off 526Use fixed settings for host audio. When off, it will change based on 527how the guest opens the sound card. In this case you must not specify 528@var{frequency}, @var{channels} or @var{format}. Default is on. 529 530@item in|out.frequency=@var{frequency} 531Specify the @var{frequency} to use when using @var{fixed-settings}. 532Default is 44100Hz. 533 534@item in|out.channels=@var{channels} 535Specify the number of @var{channels} to use when using 536@var{fixed-settings}. Default is 2 (stereo). 537 538@item in|out.format=@var{format} 539Specify the sample @var{format} to use when using @var{fixed-settings}. 540Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8}, 541@code{u16}, @code{u32}. Default is @code{s16}. 542 543@item in|out.voices=@var{voices} 544Specify the number of @var{voices} to use. Default is 1. 545 546@item in|out.buffer-length=@var{usecs} 547Sets the size of the buffer in microseconds. 548 549@end table 550 551@item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]] 552Creates a dummy backend that discards all outputs. This backend has no 553backend specific properties. 554 555@item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 556Creates backend using the ALSA. This backend is only available on 557Linux. 558 559ALSA specific options are: 560 561@table @option 562 563@item in|out.dev=@var{device} 564Specify the ALSA @var{device} to use for input and/or output. Default 565is @code{default}. 566 567@item in|out.period-length=@var{usecs} 568Sets the period length in microseconds. 569 570@item in|out.try-poll=on|off 571Attempt to use poll mode with the device. Default is on. 572 573@item threshold=@var{threshold} 574Threshold (in microseconds) when playback starts. Default is 0. 575 576@end table 577 578@item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]] 579Creates a backend using Apple's Core Audio. This backend is only 580available on Mac OS and only supports playback. 581 582Core Audio specific options are: 583 584@table @option 585 586@item in|out.buffer-count=@var{count} 587Sets the @var{count} of the buffers. 588 589@end table 590 591@item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]] 592Creates a backend using Microsoft's DirectSound. This backend is only 593available on Windows and only supports playback. 594 595DirectSound specific options are: 596 597@table @option 598 599@item latency=@var{usecs} 600Add extra @var{usecs} microseconds latency to playback. Default is 60110000 (10 ms). 602 603@end table 604 605@item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]] 606Creates a backend using OSS. This backend is available on most 607Unix-like systems. 608 609OSS specific options are: 610 611@table @option 612 613@item in|out.dev=@var{device} 614Specify the file name of the OSS @var{device} to use. Default is 615@code{/dev/dsp}. 616 617@item in|out.buffer-count=@var{count} 618Sets the @var{count} of the buffers. 619 620@item in|out.try-poll=on|of 621Attempt to use poll mode with the device. Default is on. 622 623@item try-mmap=on|off 624Try using memory mapped device access. Default is off. 625 626@item exclusive=on|off 627Open the device in exclusive mode (vmix won't work in this case). 628Default is off. 629 630@item dsp-policy=@var{policy} 631Sets the timing policy (between 0 and 10, where smaller number means 632smaller latency but higher CPU usage). Use -1 to use buffer sizes 633specified by @code{buffer} and @code{buffer-count}. This option is 634ignored if you do not have OSS 4. Default is 5. 635 636@end table 637 638@item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 639Creates a backend using PulseAudio. This backend is available on most 640systems. 641 642PulseAudio specific options are: 643 644@table @option 645 646@item server=@var{server} 647Sets the PulseAudio @var{server} to connect to. 648 649@item in|out.name=@var{sink} 650Use the specified source/sink for recording/playback. 651 652@item in|out.latency=@var{usecs} 653Desired latency in microseconds. The PulseAudio server will try to honor this 654value but actual latencies may be lower or higher. 655 656@end table 657 658@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]] 659Creates a backend using SDL. This backend is available on most systems, 660but you should use your platform's native backend if possible. This 661backend has no backend specific properties. 662 663@item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]] 664Creates a backend that sends audio through SPICE. This backend requires 665@code{-spice} and automatically selected in that case, so usually you 666can ignore this option. This backend has no backend specific 667properties. 668 669@item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]] 670Creates a backend that writes audio to a WAV file. 671 672Backend specific options are: 673 674@table @option 675 676@item path=@var{path} 677Write recorded audio into the specified file. Default is 678@code{qemu.wav}. 679 680@end table 681ETEXI 682 683DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 684 "-soundhw c1,... enable audio support\n" 685 " and only specified sound cards (comma separated list)\n" 686 " use '-soundhw help' to get the list of supported cards\n" 687 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 688STEXI 689@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 690@findex -soundhw 691Enable audio and selected sound hardware. Use 'help' to print all 692available sound hardware. For example: 693 694@example 695@value{qemu_system_x86} -soundhw sb16,adlib disk.img 696@value{qemu_system_x86} -soundhw es1370 disk.img 697@value{qemu_system_x86} -soundhw ac97 disk.img 698@value{qemu_system_x86} -soundhw hda disk.img 699@value{qemu_system_x86} -soundhw all disk.img 700@value{qemu_system_x86} -soundhw help 701@end example 702 703Note that Linux's i810_audio OSS kernel (for AC97) module might 704require manually specifying clocking. 705 706@example 707modprobe i810_audio clocking=48000 708@end example 709ETEXI 710 711DEF("device", HAS_ARG, QEMU_OPTION_device, 712 "-device driver[,prop[=value][,...]]\n" 713 " add device (based on driver)\n" 714 " prop=value,... sets driver properties\n" 715 " use '-device help' to print all possible drivers\n" 716 " use '-device driver,help' to print all possible properties\n", 717 QEMU_ARCH_ALL) 718STEXI 719@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 720@findex -device 721Add device @var{driver}. @var{prop}=@var{value} sets driver 722properties. Valid properties depend on the driver. To get help on 723possible drivers and properties, use @code{-device help} and 724@code{-device @var{driver},help}. 725 726Some drivers are: 727@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}] 728 729Add an IPMI BMC. This is a simulation of a hardware management 730interface processor that normally sits on a system. It provides 731a watchdog and the ability to reset and power control the system. 732You need to connect this to an IPMI interface to make it useful 733 734The IPMI slave address to use for the BMC. The default is 0x20. 735This address is the BMC's address on the I2C network of management 736controllers. If you don't know what this means, it is safe to ignore 737it. 738 739@table @option 740@item id=@var{id} 741The BMC id for interfaces to use this device. 742@item slave_addr=@var{val} 743Define slave address to use for the BMC. The default is 0x20. 744@item sdrfile=@var{file} 745file containing raw Sensor Data Records (SDR) data. The default is none. 746@item fruareasize=@var{val} 747size of a Field Replaceable Unit (FRU) area. The default is 1024. 748@item frudatafile=@var{file} 749file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 750@item guid=@var{uuid} 751value for the GUID for the BMC, in standard UUID format. If this is set, 752get "Get GUID" command to the BMC will return it. Otherwise "Get GUID" 753will return an error. 754@end table 755 756@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 757 758Add a connection to an external IPMI BMC simulator. Instead of 759locally emulating the BMC like the above item, instead connect 760to an external entity that provides the IPMI services. 761 762A connection is made to an external BMC simulator. If you do this, it 763is strongly recommended that you use the "reconnect=" chardev option 764to reconnect to the simulator if the connection is lost. Note that if 765this is not used carefully, it can be a security issue, as the 766interface has the ability to send resets, NMIs, and power off the VM. 767It's best if QEMU makes a connection to an external simulator running 768on a secure port on localhost, so neither the simulator nor QEMU is 769exposed to any outside network. 770 771See the "lanserv/README.vm" file in the OpenIPMI library for more 772details on the external interface. 773 774@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 775 776Add a KCS IPMI interafce on the ISA bus. This also adds a 777corresponding ACPI and SMBIOS entries, if appropriate. 778 779@table @option 780@item bmc=@var{id} 781The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 782@item ioport=@var{val} 783Define the I/O address of the interface. The default is 0xca0 for KCS. 784@item irq=@var{val} 785Define the interrupt to use. The default is 5. To disable interrupts, 786set this to 0. 787@end table 788 789@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 790 791Like the KCS interface, but defines a BT interface. The default port is 7920xe4 and the default interrupt is 5. 793 794ETEXI 795 796DEF("name", HAS_ARG, QEMU_OPTION_name, 797 "-name string1[,process=string2][,debug-threads=on|off]\n" 798 " set the name of the guest\n" 799 " string1 sets the window title and string2 the process name\n" 800 " When debug-threads is enabled, individual threads are given a separate name\n" 801 " NOTE: The thread names are for debugging and not a stable API.\n", 802 QEMU_ARCH_ALL) 803STEXI 804@item -name @var{name} 805@findex -name 806Sets the @var{name} of the guest. 807This name will be displayed in the SDL window caption. 808The @var{name} will also be used for the VNC server. 809Also optionally set the top visible process name in Linux. 810Naming of individual threads can also be enabled on Linux to aid debugging. 811ETEXI 812 813DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 814 "-uuid %08x-%04x-%04x-%04x-%012x\n" 815 " specify machine UUID\n", QEMU_ARCH_ALL) 816STEXI 817@item -uuid @var{uuid} 818@findex -uuid 819Set system UUID. 820ETEXI 821 822STEXI 823@end table 824ETEXI 825DEFHEADING() 826 827DEFHEADING(Block device options:) 828STEXI 829@table @option 830ETEXI 831 832DEF("fda", HAS_ARG, QEMU_OPTION_fda, 833 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 834DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 835STEXI 836@item -fda @var{file} 837@itemx -fdb @var{file} 838@findex -fda 839@findex -fdb 840Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 841ETEXI 842 843DEF("hda", HAS_ARG, QEMU_OPTION_hda, 844 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 845DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 846DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 847 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 848DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 849STEXI 850@item -hda @var{file} 851@itemx -hdb @var{file} 852@itemx -hdc @var{file} 853@itemx -hdd @var{file} 854@findex -hda 855@findex -hdb 856@findex -hdc 857@findex -hdd 858Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 859ETEXI 860 861DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 862 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 863 QEMU_ARCH_ALL) 864STEXI 865@item -cdrom @var{file} 866@findex -cdrom 867Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 868@option{-cdrom} at the same time). You can use the host CD-ROM by 869using @file{/dev/cdrom} as filename (@pxref{host_drives}). 870ETEXI 871 872DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 873 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 874 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 875 " [,read-only=on|off][,auto-read-only=on|off]\n" 876 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 877 " [,driver specific parameters...]\n" 878 " configure a block backend\n", QEMU_ARCH_ALL) 879STEXI 880@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 881@findex -blockdev 882 883Define a new block driver node. Some of the options apply to all block drivers, 884other options are only accepted for a specific block driver. See below for a 885list of generic options and options for the most common block drivers. 886 887Options that expect a reference to another node (e.g. @code{file}) can be 888given in two ways. Either you specify the node name of an already existing node 889(file=@var{node-name}), or you define a new node inline, adding options 890for the referenced node after a dot (file.filename=@var{path},file.aio=native). 891 892A block driver node created with @option{-blockdev} can be used for a guest 893device by specifying its node name for the @code{drive} property in a 894@option{-device} argument that defines a block device. 895 896@table @option 897@item Valid options for any block driver node: 898 899@table @code 900@item driver 901Specifies the block driver to use for the given node. 902@item node-name 903This defines the name of the block driver node by which it will be referenced 904later. The name must be unique, i.e. it must not match the name of a different 905block driver node, or (if you use @option{-drive} as well) the ID of a drive. 906 907If no node name is specified, it is automatically generated. The generated node 908name is not intended to be predictable and changes between QEMU invocations. 909For the top level, an explicit node name must be specified. 910@item read-only 911Open the node read-only. Guest write attempts will fail. 912 913Note that some block drivers support only read-only access, either generally or 914in certain configurations. In this case, the default value 915@option{read-only=off} does not work and the option must be specified 916explicitly. 917@item auto-read-only 918If @option{auto-read-only=on} is set, QEMU may fall back to read-only usage 919even when @option{read-only=off} is requested, or even switch between modes as 920needed, e.g. depending on whether the image file is writable or whether a 921writing user is attached to the node. 922@item force-share 923Override the image locking system of QEMU by forcing the node to utilize 924weaker shared access for permissions where it would normally request exclusive 925access. When there is the potential for multiple instances to have the same 926file open (whether this invocation of QEMU is the first or the second 927instance), both instances must permit shared access for the second instance to 928succeed at opening the file. 929 930Enabling @option{force-share=on} requires @option{read-only=on}. 931@item cache.direct 932The host page cache can be avoided with @option{cache.direct=on}. This will 933attempt to do disk IO directly to the guest's memory. QEMU may still perform an 934internal copy of the data. 935@item cache.no-flush 936In case you don't care about data integrity over host failures, you can use 937@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 938any data to the disk but can instead keep things in cache. If anything goes 939wrong, like your host losing power, the disk storage getting disconnected 940accidentally, etc. your image will most probably be rendered unusable. 941@item discard=@var{discard} 942@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 943whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 944ignored or passed to the filesystem. Some machine types may not support 945discard requests. 946@item detect-zeroes=@var{detect-zeroes} 947@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 948conversion of plain zero writes by the OS to driver specific optimized 949zero write commands. You may even choose "unmap" if @var{discard} is set 950to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 951@end table 952 953@item Driver-specific options for @code{file} 954 955This is the protocol-level block driver for accessing regular files. 956 957@table @code 958@item filename 959The path to the image file in the local filesystem 960@item aio 961Specifies the AIO backend (threads/native, default: threads) 962@item locking 963Specifies whether the image file is protected with Linux OFD / POSIX locks. The 964default is to use the Linux Open File Descriptor API if available, otherwise no 965lock is applied. (auto/on/off, default: auto) 966@end table 967Example: 968@example 969-blockdev driver=file,node-name=disk,filename=disk.img 970@end example 971 972@item Driver-specific options for @code{raw} 973 974This is the image format block driver for raw images. It is usually 975stacked on top of a protocol level block driver such as @code{file}. 976 977@table @code 978@item file 979Reference to or definition of the data source block driver node 980(e.g. a @code{file} driver node) 981@end table 982Example 1: 983@example 984-blockdev driver=file,node-name=disk_file,filename=disk.img 985-blockdev driver=raw,node-name=disk,file=disk_file 986@end example 987Example 2: 988@example 989-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 990@end example 991 992@item Driver-specific options for @code{qcow2} 993 994This is the image format block driver for qcow2 images. It is usually 995stacked on top of a protocol level block driver such as @code{file}. 996 997@table @code 998@item file 999Reference to or definition of the data source block driver node 1000(e.g. a @code{file} driver node) 1001 1002@item backing 1003Reference to or definition of the backing file block device (default is taken 1004from the image file). It is allowed to pass @code{null} here in order to disable 1005the default backing file. 1006 1007@item lazy-refcounts 1008Whether to enable the lazy refcounts feature (on/off; default is taken from the 1009image file) 1010 1011@item cache-size 1012The maximum total size of the L2 table and refcount block caches in bytes 1013(default: the sum of l2-cache-size and refcount-cache-size) 1014 1015@item l2-cache-size 1016The maximum size of the L2 table cache in bytes 1017(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 1018non-Linux platforms; otherwise, as large as possible within the cache-size, 1019while permitting the requested or the minimal refcount cache size) 1020 1021@item refcount-cache-size 1022The maximum size of the refcount block cache in bytes 1023(default: 4 times the cluster size; or if cache-size is specified, the part of 1024it which is not used for the L2 cache) 1025 1026@item cache-clean-interval 1027Clean unused entries in the L2 and refcount caches. The interval is in seconds. 1028The default value is 600 on supporting platforms, and 0 on other platforms. 1029Setting it to 0 disables this feature. 1030 1031@item pass-discard-request 1032Whether discard requests to the qcow2 device should be forwarded to the data 1033source (on/off; default: on if discard=unmap is specified, off otherwise) 1034 1035@item pass-discard-snapshot 1036Whether discard requests for the data source should be issued when a snapshot 1037operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 1038default: on) 1039 1040@item pass-discard-other 1041Whether discard requests for the data source should be issued on other 1042occasions where a cluster gets freed (on/off; default: off) 1043 1044@item overlap-check 1045Which overlap checks to perform for writes to the image 1046(none/constant/cached/all; default: cached). For details or finer 1047granularity control refer to the QAPI documentation of @code{blockdev-add}. 1048@end table 1049 1050Example 1: 1051@example 1052-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1053-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1054@end example 1055Example 2: 1056@example 1057-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1058@end example 1059 1060@item Driver-specific options for other drivers 1061Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1062 1063@end table 1064 1065ETEXI 1066 1067DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1068 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1069 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1070 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1071 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1072 " [,readonly=on|off][,copy-on-read=on|off]\n" 1073 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1074 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1075 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1076 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1077 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1078 " [[,iops_size=is]]\n" 1079 " [[,group=g]]\n" 1080 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1081STEXI 1082@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1083@findex -drive 1084 1085Define a new drive. This includes creating a block driver node (the backend) as 1086well as a guest device, and is mostly a shortcut for defining the corresponding 1087@option{-blockdev} and @option{-device} options. 1088 1089@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1090addition, it knows the following options: 1091 1092@table @option 1093@item file=@var{file} 1094This option defines which disk image (@pxref{disk_images}) to use with 1095this drive. If the filename contains comma, you must double it 1096(for instance, "file=my,,file" to use file "my,file"). 1097 1098Special files such as iSCSI devices can be specified using protocol 1099specific URLs. See the section for "Device URL Syntax" for more information. 1100@item if=@var{interface} 1101This option defines on which type on interface the drive is connected. 1102Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1103@item bus=@var{bus},unit=@var{unit} 1104These options define where is connected the drive by defining the bus number and 1105the unit id. 1106@item index=@var{index} 1107This option defines where is connected the drive by using an index in the list 1108of available connectors of a given interface type. 1109@item media=@var{media} 1110This option defines the type of the media: disk or cdrom. 1111@item snapshot=@var{snapshot} 1112@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1113(see @option{-snapshot}). 1114@item cache=@var{cache} 1115@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1116and controls how the host cache is used to access block data. This is a 1117shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1118options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1119which provides a default for the @option{write-cache} option of block guest 1120devices (as in @option{-device}). The modes correspond to the following 1121settings: 1122 1123@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1124@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1125@c and the HTML output. 1126@example 1127@ │ cache.writeback cache.direct cache.no-flush 1128─────────────┼───────────────────────────────────────────────── 1129writeback │ on off off 1130none │ on on off 1131writethrough │ off off off 1132directsync │ off on off 1133unsafe │ on off on 1134@end example 1135 1136The default mode is @option{cache=writeback}. 1137 1138@item aio=@var{aio} 1139@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1140@item format=@var{format} 1141Specify which disk @var{format} will be used rather than detecting 1142the format. Can be used to specify format=raw to avoid interpreting 1143an untrusted format header. 1144@item werror=@var{action},rerror=@var{action} 1145Specify which @var{action} to take on write and read errors. Valid actions are: 1146"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1147"report" (report the error to the guest), "enospc" (pause QEMU only if the 1148host disk is full; report the error to the guest otherwise). 1149The default setting is @option{werror=enospc} and @option{rerror=report}. 1150@item copy-on-read=@var{copy-on-read} 1151@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1152file sectors into the image file. 1153@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1154Specify bandwidth throttling limits in bytes per second, either for all request 1155types or for reads or writes only. Small values can lead to timeouts or hangs 1156inside the guest. A safe minimum for disks is 2 MB/s. 1157@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1158Specify bursts in bytes per second, either for all request types or for reads 1159or writes only. Bursts allow the guest I/O to spike above the limit 1160temporarily. 1161@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1162Specify request rate limits in requests per second, either for all request 1163types or for reads or writes only. 1164@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1165Specify bursts in requests per second, either for all request types or for reads 1166or writes only. Bursts allow the guest I/O to spike above the limit 1167temporarily. 1168@item iops_size=@var{is} 1169Let every @var{is} bytes of a request count as a new request for iops 1170throttling purposes. Use this option to prevent guests from circumventing iops 1171limits by sending fewer but larger requests. 1172@item group=@var{g} 1173Join a throttling quota group with given name @var{g}. All drives that are 1174members of the same group are accounted for together. Use this option to 1175prevent guests from circumventing throttling limits by using many small disks 1176instead of a single larger disk. 1177@end table 1178 1179By default, the @option{cache.writeback=on} mode is used. It will report data 1180writes as completed as soon as the data is present in the host page cache. 1181This is safe as long as your guest OS makes sure to correctly flush disk caches 1182where needed. If your guest OS does not handle volatile disk write caches 1183correctly and your host crashes or loses power, then the guest may experience 1184data corruption. 1185 1186For such guests, you should consider using @option{cache.writeback=off}. This 1187means that the host page cache will be used to read and write data, but write 1188notification will be sent to the guest only after QEMU has made sure to flush 1189each write to the disk. Be aware that this has a major impact on performance. 1190 1191When using the @option{-snapshot} option, unsafe caching is always used. 1192 1193Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1194useful when the backing file is over a slow network. By default copy-on-read 1195is off. 1196 1197Instead of @option{-cdrom} you can use: 1198@example 1199@value{qemu_system} -drive file=file,index=2,media=cdrom 1200@end example 1201 1202Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1203use: 1204@example 1205@value{qemu_system} -drive file=file,index=0,media=disk 1206@value{qemu_system} -drive file=file,index=1,media=disk 1207@value{qemu_system} -drive file=file,index=2,media=disk 1208@value{qemu_system} -drive file=file,index=3,media=disk 1209@end example 1210 1211You can open an image using pre-opened file descriptors from an fd set: 1212@example 1213@value{qemu_system} \ 1214 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 1215 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 1216 -drive file=/dev/fdset/2,index=0,media=disk 1217@end example 1218 1219You can connect a CDROM to the slave of ide0: 1220@example 1221@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom 1222@end example 1223 1224If you don't specify the "file=" argument, you define an empty drive: 1225@example 1226@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom 1227@end example 1228 1229Instead of @option{-fda}, @option{-fdb}, you can use: 1230@example 1231@value{qemu_system_x86} -drive file=file,index=0,if=floppy 1232@value{qemu_system_x86} -drive file=file,index=1,if=floppy 1233@end example 1234 1235By default, @var{interface} is "ide" and @var{index} is automatically 1236incremented: 1237@example 1238@value{qemu_system_x86} -drive file=a -drive file=b" 1239@end example 1240is interpreted like: 1241@example 1242@value{qemu_system_x86} -hda a -hdb b 1243@end example 1244ETEXI 1245 1246DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1247 "-mtdblock file use 'file' as on-board Flash memory image\n", 1248 QEMU_ARCH_ALL) 1249STEXI 1250@item -mtdblock @var{file} 1251@findex -mtdblock 1252Use @var{file} as on-board Flash memory image. 1253ETEXI 1254 1255DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1256 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1257STEXI 1258@item -sd @var{file} 1259@findex -sd 1260Use @var{file} as SecureDigital card image. 1261ETEXI 1262 1263DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1264 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1265STEXI 1266@item -pflash @var{file} 1267@findex -pflash 1268Use @var{file} as a parallel flash image. 1269ETEXI 1270 1271DEF("snapshot", 0, QEMU_OPTION_snapshot, 1272 "-snapshot write to temporary files instead of disk image files\n", 1273 QEMU_ARCH_ALL) 1274STEXI 1275@item -snapshot 1276@findex -snapshot 1277Write to temporary files instead of disk image files. In this case, 1278the raw disk image you use is not written back. You can however force 1279the write back by pressing @key{C-a s} (@pxref{disk_images}). 1280ETEXI 1281 1282DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1283 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1284 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1285 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1286 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1287 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1288 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1289 " [[,throttling.iops-size=is]]\n" 1290 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1291 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1292 "-fsdev synth,id=id\n", 1293 QEMU_ARCH_ALL) 1294 1295STEXI 1296 1297@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}[,...]]] 1298@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1299@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1300@itemx -fsdev synth,id=@var{id}[,readonly] 1301@findex -fsdev 1302Define a new file system device. Valid options are: 1303@table @option 1304@item local 1305Accesses to the filesystem are done by QEMU. 1306@item proxy 1307Accesses to the filesystem are done by virtfs-proxy-helper(1). 1308@item synth 1309Synthetic filesystem, only used by QTests. 1310@item id=@var{id} 1311Specifies identifier for this device. 1312@item path=@var{path} 1313Specifies the export path for the file system device. Files under 1314this path will be available to the 9p client on the guest. 1315@item security_model=@var{security_model} 1316Specifies the security model to be used for this export path. 1317Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1318In "passthrough" security model, files are stored using the same 1319credentials as they are created on the guest. This requires QEMU 1320to run as root. In "mapped-xattr" security model, some of the file 1321attributes like uid, gid, mode bits and link target are stored as 1322file attributes. For "mapped-file" these attributes are stored in the 1323hidden .virtfs_metadata directory. Directories exported by this security model cannot 1324interact with other unix tools. "none" security model is same as 1325passthrough except the sever won't report failures if it fails to 1326set file attributes like ownership. Security model is mandatory 1327only for local fsdriver. Other fsdrivers (like proxy) don't take 1328security model as a parameter. 1329@item writeout=@var{writeout} 1330This is an optional argument. The only supported value is "immediate". 1331This means that host page cache will be used to read and write data but 1332write notification will be sent to the guest only when the data has been 1333reported as written by the storage subsystem. 1334@item readonly 1335Enables exporting 9p share as a readonly mount for guests. By default 1336read-write access is given. 1337@item socket=@var{socket} 1338Enables proxy filesystem driver to use passed socket file for communicating 1339with virtfs-proxy-helper(1). 1340@item sock_fd=@var{sock_fd} 1341Enables proxy filesystem driver to use passed socket descriptor for 1342communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1343will create socketpair and pass one of the fds as sock_fd. 1344@item fmode=@var{fmode} 1345Specifies the default mode for newly created files on the host. Works only 1346with security models "mapped-xattr" and "mapped-file". 1347@item dmode=@var{dmode} 1348Specifies the default mode for newly created directories on the host. Works 1349only with security models "mapped-xattr" and "mapped-file". 1350@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1351Specify bandwidth throttling limits in bytes per second, either for all request 1352types or for reads or writes only. 1353@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1354Specify bursts in bytes per second, either for all request types or for reads 1355or writes only. Bursts allow the guest I/O to spike above the limit 1356temporarily. 1357@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1358Specify request rate limits in requests per second, either for all request 1359types or for reads or writes only. 1360@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1361Specify bursts in requests per second, either for all request types or for reads 1362or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1363@item throttling.iops-size=@var{is} 1364Let every @var{is} bytes of a request count as a new request for iops 1365throttling purposes. 1366@end table 1367 1368-fsdev option is used along with -device driver "virtio-9p-...". 1369@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1370Options for virtio-9p-... driver are: 1371@table @option 1372@item @var{type} 1373Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1374depending on the machine type. 1375@item fsdev=@var{id} 1376Specifies the id value specified along with -fsdev option. 1377@item mount_tag=@var{mount_tag} 1378Specifies the tag name to be used by the guest to mount this export point. 1379@end table 1380 1381ETEXI 1382 1383DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1384 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1385 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1386 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1387 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1388 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1389 QEMU_ARCH_ALL) 1390 1391STEXI 1392 1393@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}][,multidevs=@var{multidevs}] 1394@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1395@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1396@itemx -virtfs synth,mount_tag=@var{mount_tag} 1397@findex -virtfs 1398 1399Define 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: 1400@table @option 1401@item local 1402Accesses to the filesystem are done by QEMU. 1403@item proxy 1404Accesses to the filesystem are done by virtfs-proxy-helper(1). 1405@item synth 1406Synthetic filesystem, only used by QTests. 1407@item id=@var{id} 1408Specifies identifier for the filesystem device 1409@item path=@var{path} 1410Specifies the export path for the file system device. Files under 1411this path will be available to the 9p client on the guest. 1412@item security_model=@var{security_model} 1413Specifies the security model to be used for this export path. 1414Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1415In "passthrough" security model, files are stored using the same 1416credentials as they are created on the guest. This requires QEMU 1417to run as root. In "mapped-xattr" security model, some of the file 1418attributes like uid, gid, mode bits and link target are stored as 1419file attributes. For "mapped-file" these attributes are stored in the 1420hidden .virtfs_metadata directory. Directories exported by this security model cannot 1421interact with other unix tools. "none" security model is same as 1422passthrough except the sever won't report failures if it fails to 1423set file attributes like ownership. Security model is mandatory only 1424for local fsdriver. Other fsdrivers (like proxy) don't take security 1425model as a parameter. 1426@item writeout=@var{writeout} 1427This is an optional argument. The only supported value is "immediate". 1428This means that host page cache will be used to read and write data but 1429write notification will be sent to the guest only when the data has been 1430reported as written by the storage subsystem. 1431@item readonly 1432Enables exporting 9p share as a readonly mount for guests. By default 1433read-write access is given. 1434@item socket=@var{socket} 1435Enables proxy filesystem driver to use passed socket file for 1436communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1437will create socketpair and pass one of the fds as sock_fd. 1438@item sock_fd 1439Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1440descriptor for interfacing with virtfs-proxy-helper(1). 1441@item fmode=@var{fmode} 1442Specifies the default mode for newly created files on the host. Works only 1443with security models "mapped-xattr" and "mapped-file". 1444@item dmode=@var{dmode} 1445Specifies the default mode for newly created directories on the host. Works 1446only with security models "mapped-xattr" and "mapped-file". 1447@item mount_tag=@var{mount_tag} 1448Specifies the tag name to be used by the guest to mount this export point. 1449@item multidevs=@var{multidevs} 1450Specifies how to deal with multiple devices being shared with a 9p export. 1451Supported behaviours are either "remap", "forbid" or "warn". The latter is 1452the default behaviour on which virtfs 9p expects only one device to be 1453shared with the same export, and if more than one device is shared and 1454accessed via the same 9p export then only a warning message is logged 1455(once) by qemu on host side. In order to avoid file ID collisions on guest 1456you should either create a separate virtfs export for each device to be 1457shared with guests (recommended way) or you might use "remap" instead which 1458allows you to share multiple devices with only one export instead, which is 1459achieved by remapping the original inode numbers from host to guest in a 1460way that would prevent such collisions. Remapping inodes in such use cases 1461is required because the original device IDs from host are never passed and 1462exposed on guest. Instead all files of an export shared with virtfs always 1463share the same device id on guest. So two files with identical inode 1464numbers but from actually different devices on host would otherwise cause a 1465file ID collision and hence potential misbehaviours on guest. "forbid" on 1466the other hand assumes like "warn" that only one device is shared by the 1467same export, however it will not only log a warning message but also 1468deny access to additional devices on guest. Note though that "forbid" does 1469currently not block all possible file access operations (e.g. readdir() 1470would still return entries from other devices). 1471@end table 1472ETEXI 1473 1474DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1475 "-iscsi [user=user][,password=password]\n" 1476 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1477 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1478 " [,timeout=timeout]\n" 1479 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1480 1481STEXI 1482@item -iscsi 1483@findex -iscsi 1484Configure iSCSI session parameters. 1485ETEXI 1486 1487STEXI 1488@end table 1489ETEXI 1490DEFHEADING() 1491 1492DEFHEADING(USB options:) 1493STEXI 1494@table @option 1495ETEXI 1496 1497DEF("usb", 0, QEMU_OPTION_usb, 1498 "-usb enable on-board USB host controller (if not enabled by default)\n", 1499 QEMU_ARCH_ALL) 1500STEXI 1501@item -usb 1502@findex -usb 1503Enable USB emulation on machine types with an on-board USB host controller (if 1504not enabled by default). Note that on-board USB host controllers may not 1505support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1506on machines with PCI. 1507ETEXI 1508 1509DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1510 "-usbdevice name add the host or guest USB device 'name'\n", 1511 QEMU_ARCH_ALL) 1512STEXI 1513 1514@item -usbdevice @var{devname} 1515@findex -usbdevice 1516Add the USB device @var{devname}. Note that this option is deprecated, 1517please use @code{-device usb-...} instead. @xref{usb_devices}. 1518 1519@table @option 1520 1521@item mouse 1522Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1523 1524@item tablet 1525Pointer device that uses absolute coordinates (like a touchscreen). This 1526means QEMU is able to report the mouse position without having to grab the 1527mouse. Also overrides the PS/2 mouse emulation when activated. 1528 1529@item braille 1530Braille device. This will use BrlAPI to display the braille output on a real 1531or fake device. 1532 1533@end table 1534ETEXI 1535 1536STEXI 1537@end table 1538ETEXI 1539DEFHEADING() 1540 1541DEFHEADING(Display options:) 1542STEXI 1543@table @option 1544ETEXI 1545 1546DEF("display", HAS_ARG, QEMU_OPTION_display, 1547#if defined(CONFIG_SPICE) 1548 "-display spice-app[,gl=on|off]\n" 1549#endif 1550#if defined(CONFIG_SDL) 1551 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n" 1552 " [,window_close=on|off][,gl=on|core|es|off]\n" 1553#endif 1554#if defined(CONFIG_GTK) 1555 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1556#endif 1557#if defined(CONFIG_VNC) 1558 "-display vnc=<display>[,<optargs>]\n" 1559#endif 1560#if defined(CONFIG_CURSES) 1561 "-display curses[,charset=<encoding>]\n" 1562#endif 1563#if defined(CONFIG_OPENGL) 1564 "-display egl-headless[,rendernode=<file>]\n" 1565#endif 1566 "-display none\n" 1567 " select display backend type\n" 1568 " The default display is equivalent to\n " 1569#if defined(CONFIG_GTK) 1570 "\"-display gtk\"\n" 1571#elif defined(CONFIG_SDL) 1572 "\"-display sdl\"\n" 1573#elif defined(CONFIG_COCOA) 1574 "\"-display cocoa\"\n" 1575#elif defined(CONFIG_VNC) 1576 "\"-vnc localhost:0,to=99,id=default\"\n" 1577#else 1578 "\"-display none\"\n" 1579#endif 1580 , QEMU_ARCH_ALL) 1581STEXI 1582@item -display @var{type} 1583@findex -display 1584Select type of display to use. This option is a replacement for the 1585old style -sdl/-curses/... options. Valid values for @var{type} are 1586@table @option 1587@item sdl 1588Display video output via SDL (usually in a separate graphics 1589window; see the SDL documentation for other possibilities). 1590@item curses 1591Display video output via curses. For graphics device models which 1592support a text mode, QEMU can display this output using a 1593curses/ncurses interface. Nothing is displayed when the graphics 1594device is in graphical mode or if the graphics device does not support 1595a text mode. Generally only the VGA device models support text mode. 1596The font charset used by the guest can be specified with the 1597@code{charset} option, for example @code{charset=CP850} for IBM CP850 1598encoding. The default is @code{CP437}. 1599@item none 1600Do not display video output. The guest will still see an emulated 1601graphics card, but its output will not be displayed to the QEMU 1602user. This option differs from the -nographic option in that it 1603only affects what is done with video output; -nographic also changes 1604the destination of the serial and parallel port data. 1605@item gtk 1606Display video output in a GTK window. This interface provides drop-down 1607menus and other UI elements to configure and control the VM during 1608runtime. 1609@item vnc 1610Start a VNC server on display <arg> 1611@item egl-headless 1612Offload all OpenGL operations to a local DRI device. For any graphical display, 1613this display needs to be paired with either VNC or SPICE displays. 1614@item spice-app 1615Start QEMU as a Spice server and launch the default Spice client 1616application. The Spice server will redirect the serial consoles and 1617QEMU monitors. (Since 4.0) 1618@end table 1619ETEXI 1620 1621DEF("nographic", 0, QEMU_OPTION_nographic, 1622 "-nographic disable graphical output and redirect serial I/Os to console\n", 1623 QEMU_ARCH_ALL) 1624STEXI 1625@item -nographic 1626@findex -nographic 1627Normally, if QEMU is compiled with graphical window support, it displays 1628output such as guest graphics, guest console, and the QEMU monitor in a 1629window. With this option, you can totally disable graphical output so 1630that QEMU is a simple command line application. The emulated serial port 1631is redirected on the console and muxed with the monitor (unless 1632redirected elsewhere explicitly). Therefore, you can still use QEMU to 1633debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1634switching between the console and monitor. 1635ETEXI 1636 1637DEF("curses", 0, QEMU_OPTION_curses, 1638 "-curses shorthand for -display curses\n", 1639 QEMU_ARCH_ALL) 1640STEXI 1641@item -curses 1642@findex -curses 1643Normally, if QEMU is compiled with graphical window support, it displays 1644output such as guest graphics, guest console, and the QEMU monitor in a 1645window. With this option, QEMU can display the VGA output when in text 1646mode using a curses/ncurses interface. Nothing is displayed in graphical 1647mode. 1648ETEXI 1649 1650DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1651 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1652 QEMU_ARCH_ALL) 1653STEXI 1654@item -alt-grab 1655@findex -alt-grab 1656Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1657affects the special keys (for fullscreen, monitor-mode switching, etc). 1658ETEXI 1659 1660DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1661 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1662 QEMU_ARCH_ALL) 1663STEXI 1664@item -ctrl-grab 1665@findex -ctrl-grab 1666Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1667affects the special keys (for fullscreen, monitor-mode switching, etc). 1668ETEXI 1669 1670DEF("no-quit", 0, QEMU_OPTION_no_quit, 1671 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1672STEXI 1673@item -no-quit 1674@findex -no-quit 1675Disable SDL window close capability. 1676ETEXI 1677 1678DEF("sdl", 0, QEMU_OPTION_sdl, 1679 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1680STEXI 1681@item -sdl 1682@findex -sdl 1683Enable SDL. 1684ETEXI 1685 1686DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1687 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1688 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1689 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1690 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1691 " [,tls-ciphers=<list>]\n" 1692 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1693 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1694 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1695 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1696 " [,jpeg-wan-compression=[auto|never|always]]\n" 1697 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1698 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1699 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1700 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1701 " [,gl=[on|off]][,rendernode=<file>]\n" 1702 " enable spice\n" 1703 " at least one of {port, tls-port} is mandatory\n", 1704 QEMU_ARCH_ALL) 1705STEXI 1706@item -spice @var{option}[,@var{option}[,...]] 1707@findex -spice 1708Enable the spice remote desktop protocol. Valid options are 1709 1710@table @option 1711 1712@item port=<nr> 1713Set the TCP port spice is listening on for plaintext channels. 1714 1715@item addr=<addr> 1716Set the IP address spice is listening on. Default is any address. 1717 1718@item ipv4 1719@itemx ipv6 1720@itemx unix 1721Force using the specified IP version. 1722 1723@item password=<secret> 1724Set the password you need to authenticate. 1725 1726@item sasl 1727Require that the client use SASL to authenticate with the spice. 1728The exact choice of authentication method used is controlled from the 1729system / user's SASL configuration file for the 'qemu' service. This 1730is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1731unprivileged user, an environment variable SASL_CONF_PATH can be used 1732to make it search alternate locations for the service config. 1733While some SASL auth methods can also provide data encryption (eg GSSAPI), 1734it is recommended that SASL always be combined with the 'tls' and 1735'x509' settings to enable use of SSL and server certificates. This 1736ensures a data encryption preventing compromise of authentication 1737credentials. 1738 1739@item disable-ticketing 1740Allow client connects without authentication. 1741 1742@item disable-copy-paste 1743Disable copy paste between the client and the guest. 1744 1745@item disable-agent-file-xfer 1746Disable spice-vdagent based file-xfer between the client and the guest. 1747 1748@item tls-port=<nr> 1749Set the TCP port spice is listening on for encrypted channels. 1750 1751@item x509-dir=<dir> 1752Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1753 1754@item x509-key-file=<file> 1755@itemx x509-key-password=<file> 1756@itemx x509-cert-file=<file> 1757@itemx x509-cacert-file=<file> 1758@itemx x509-dh-key-file=<file> 1759The x509 file names can also be configured individually. 1760 1761@item tls-ciphers=<list> 1762Specify which ciphers to use. 1763 1764@item tls-channel=[main|display|cursor|inputs|record|playback] 1765@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1766Force specific channel to be used with or without TLS encryption. The 1767options can be specified multiple times to configure multiple 1768channels. The special name "default" can be used to set the default 1769mode. For channels which are not explicitly forced into one mode the 1770spice client is allowed to pick tls/plaintext as he pleases. 1771 1772@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1773Configure image compression (lossless). 1774Default is auto_glz. 1775 1776@item jpeg-wan-compression=[auto|never|always] 1777@itemx zlib-glz-wan-compression=[auto|never|always] 1778Configure wan image compression (lossy for slow links). 1779Default is auto. 1780 1781@item streaming-video=[off|all|filter] 1782Configure video stream detection. Default is off. 1783 1784@item agent-mouse=[on|off] 1785Enable/disable passing mouse events via vdagent. Default is on. 1786 1787@item playback-compression=[on|off] 1788Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1789 1790@item seamless-migration=[on|off] 1791Enable/disable spice seamless migration. Default is off. 1792 1793@item gl=[on|off] 1794Enable/disable OpenGL context. Default is off. 1795 1796@item rendernode=<file> 1797DRM render node for OpenGL rendering. If not specified, it will pick 1798the first available. (Since 2.9) 1799 1800@end table 1801ETEXI 1802 1803DEF("portrait", 0, QEMU_OPTION_portrait, 1804 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1805 QEMU_ARCH_ALL) 1806STEXI 1807@item -portrait 1808@findex -portrait 1809Rotate graphical output 90 deg left (only PXA LCD). 1810ETEXI 1811 1812DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1813 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1814 QEMU_ARCH_ALL) 1815STEXI 1816@item -rotate @var{deg} 1817@findex -rotate 1818Rotate graphical output some deg left (only PXA LCD). 1819ETEXI 1820 1821DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1822 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1823 " select video card type\n", QEMU_ARCH_ALL) 1824STEXI 1825@item -vga @var{type} 1826@findex -vga 1827Select type of VGA card to emulate. Valid values for @var{type} are 1828@table @option 1829@item cirrus 1830Cirrus Logic GD5446 Video card. All Windows versions starting from 1831Windows 95 should recognize and use this graphic card. For optimal 1832performances, use 16 bit color depth in the guest and the host OS. 1833(This card was the default before QEMU 2.2) 1834@item std 1835Standard VGA card with Bochs VBE extensions. If your guest OS 1836supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1837to use high resolution modes (>= 1280x1024x16) then you should use 1838this option. (This card is the default since QEMU 2.2) 1839@item vmware 1840VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1841recent XFree86/XOrg server or Windows guest with a driver for this 1842card. 1843@item qxl 1844QXL paravirtual graphic card. It is VGA compatible (including VESA 18452.0 VBE support). Works best with qxl guest drivers installed though. 1846Recommended choice when using the spice protocol. 1847@item tcx 1848(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1849sun4m machines and offers both 8-bit and 24-bit colour depths at a 1850fixed resolution of 1024x768. 1851@item cg3 1852(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1853for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1854resolutions aimed at people wishing to run older Solaris versions. 1855@item virtio 1856Virtio VGA card. 1857@item none 1858Disable VGA card. 1859@end table 1860ETEXI 1861 1862DEF("full-screen", 0, QEMU_OPTION_full_screen, 1863 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1864STEXI 1865@item -full-screen 1866@findex -full-screen 1867Start in full screen. 1868ETEXI 1869 1870DEF("g", 1, QEMU_OPTION_g , 1871 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1872 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 1873STEXI 1874@item -g @var{width}x@var{height}[x@var{depth}] 1875@findex -g 1876Set the initial graphical resolution and depth (PPC, SPARC only). 1877ETEXI 1878 1879DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1880 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1881STEXI 1882@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1883@findex -vnc 1884Normally, if QEMU is compiled with graphical window support, it displays 1885output such as guest graphics, guest console, and the QEMU monitor in a 1886window. With this option, you can have QEMU listen on VNC display 1887@var{display} and redirect the VGA display over the VNC session. It is 1888very useful to enable the usb tablet device when using this option 1889(option @option{-device usb-tablet}). When using the VNC display, you 1890must use the @option{-k} parameter to set the keyboard layout if you are 1891not using en-us. Valid syntax for the @var{display} is 1892 1893@table @option 1894 1895@item to=@var{L} 1896 1897With this option, QEMU will try next available VNC @var{display}s, until the 1898number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1899available, e.g. port 5900+@var{display} is already used by another 1900application. By default, to=0. 1901 1902@item @var{host}:@var{d} 1903 1904TCP connections will only be allowed from @var{host} on display @var{d}. 1905By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1906be omitted in which case the server will accept connections from any host. 1907 1908@item unix:@var{path} 1909 1910Connections will be allowed over UNIX domain sockets where @var{path} is the 1911location of a unix socket to listen for connections on. 1912 1913@item none 1914 1915VNC is initialized but not started. The monitor @code{change} command 1916can be used to later start the VNC server. 1917 1918@end table 1919 1920Following the @var{display} value there may be one or more @var{option} flags 1921separated by commas. Valid options are 1922 1923@table @option 1924 1925@item reverse 1926 1927Connect to a listening VNC client via a ``reverse'' connection. The 1928client is specified by the @var{display}. For reverse network 1929connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1930is a TCP port number, not a display number. 1931 1932@item websocket 1933 1934Opens an additional TCP listening port dedicated to VNC Websocket connections. 1935If a bare @var{websocket} option is given, the Websocket port is 19365700+@var{display}. An alternative port can be specified with the 1937syntax @code{websocket}=@var{port}. 1938 1939If @var{host} is specified connections will only be allowed from this host. 1940It is possible to control the websocket listen address independently, using 1941the syntax @code{websocket}=@var{host}:@var{port}. 1942 1943If no TLS credentials are provided, the websocket connection runs in 1944unencrypted mode. If TLS credentials are provided, the websocket connection 1945requires encrypted client connections. 1946 1947@item password 1948 1949Require that password based authentication is used for client connections. 1950 1951The password must be set separately using the @code{set_password} command in 1952the @ref{pcsys_monitor}. The syntax to change your password is: 1953@code{set_password <protocol> <password>} where <protocol> could be either 1954"vnc" or "spice". 1955 1956If you would like to change <protocol> password expiration, you should use 1957@code{expire_password <protocol> <expiration-time>} where expiration time could 1958be one of the following options: now, never, +seconds or UNIX time of 1959expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1960to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1961date and time). 1962 1963You can also use keywords "now" or "never" for the expiration time to 1964allow <protocol> password to expire immediately or never expire. 1965 1966@item tls-creds=@var{ID} 1967 1968Provides the ID of a set of TLS credentials to use to secure the 1969VNC server. They will apply to both the normal VNC server socket 1970and the websocket socket (if enabled). Setting TLS credentials 1971will cause the VNC server socket to enable the VeNCrypt auth 1972mechanism. The credentials should have been previously created 1973using the @option{-object tls-creds} argument. 1974 1975@item tls-authz=@var{ID} 1976 1977Provides the ID of the QAuthZ authorization object against which 1978the client's x509 distinguished name will validated. This object is 1979only resolved at time of use, so can be deleted and recreated on the 1980fly while the VNC server is active. If missing, it will default 1981to denying access. 1982 1983@item sasl 1984 1985Require that the client use SASL to authenticate with the VNC server. 1986The exact choice of authentication method used is controlled from the 1987system / user's SASL configuration file for the 'qemu' service. This 1988is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1989unprivileged user, an environment variable SASL_CONF_PATH can be used 1990to make it search alternate locations for the service config. 1991While some SASL auth methods can also provide data encryption (eg GSSAPI), 1992it is recommended that SASL always be combined with the 'tls' and 1993'x509' settings to enable use of SSL and server certificates. This 1994ensures a data encryption preventing compromise of authentication 1995credentials. See the @ref{vnc_security} section for details on using 1996SASL authentication. 1997 1998@item sasl-authz=@var{ID} 1999 2000Provides the ID of the QAuthZ authorization object against which 2001the client's SASL username will validated. This object is 2002only resolved at time of use, so can be deleted and recreated on the 2003fly while the VNC server is active. If missing, it will default 2004to denying access. 2005 2006@item acl 2007 2008Legacy method for enabling authorization of clients against the 2009x509 distinguished name and SASL username. It results in the creation 2010of two @code{authz-list} objects with IDs of @code{vnc.username} and 2011@code{vnc.x509dname}. The rules for these objects must be configured 2012with the HMP ACL commands. 2013 2014This option is deprecated and should no longer be used. The new 2015@option{sasl-authz} and @option{tls-authz} options are a 2016replacement. 2017 2018@item lossy 2019 2020Enable lossy compression methods (gradient, JPEG, ...). If this 2021option is set, VNC client may receive lossy framebuffer updates 2022depending on its encoding settings. Enabling this option can save 2023a lot of bandwidth at the expense of quality. 2024 2025@item non-adaptive 2026 2027Disable adaptive encodings. Adaptive encodings are enabled by default. 2028An adaptive encoding will try to detect frequently updated screen regions, 2029and send updates in these regions using a lossy encoding (like JPEG). 2030This can be really helpful to save bandwidth when playing videos. Disabling 2031adaptive encodings restores the original static behavior of encodings 2032like Tight. 2033 2034@item share=[allow-exclusive|force-shared|ignore] 2035 2036Set display sharing policy. 'allow-exclusive' allows clients to ask 2037for exclusive access. As suggested by the rfb spec this is 2038implemented by dropping other connections. Connecting multiple 2039clients in parallel requires all clients asking for a shared session 2040(vncviewer: -shared switch). This is the default. 'force-shared' 2041disables exclusive client access. Useful for shared desktop sessions, 2042where you don't want someone forgetting specify -shared disconnect 2043everybody else. 'ignore' completely ignores the shared flag and 2044allows everybody connect unconditionally. Doesn't conform to the rfb 2045spec but is traditional QEMU behavior. 2046 2047@item key-delay-ms 2048 2049Set keyboard delay, for key down and key up events, in milliseconds. 2050Default is 10. Keyboards are low-bandwidth devices, so this slowdown 2051can help the device and guest to keep up and not lose events in case 2052events are arriving in bulk. Possible causes for the latter are flaky 2053network connections, or scripts for automated testing. 2054 2055@item audiodev=@var{audiodev} 2056 2057Use the specified @var{audiodev} when the VNC client requests audio 2058transmission. When not using an -audiodev argument, this option must 2059be omitted, otherwise is must be present and specify a valid audiodev. 2060 2061@end table 2062ETEXI 2063 2064STEXI 2065@end table 2066ETEXI 2067ARCHHEADING(, QEMU_ARCH_I386) 2068 2069ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2070STEXI 2071@table @option 2072ETEXI 2073 2074DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2075 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2076 QEMU_ARCH_I386) 2077STEXI 2078@item -win2k-hack 2079@findex -win2k-hack 2080Use it when installing Windows 2000 to avoid a disk full bug. After 2081Windows 2000 is installed, you no longer need this option (this option 2082slows down the IDE transfers). 2083ETEXI 2084 2085DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2086 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2087 QEMU_ARCH_I386) 2088STEXI 2089@item -no-fd-bootchk 2090@findex -no-fd-bootchk 2091Disable boot signature checking for floppy disks in BIOS. May 2092be needed to boot from old floppy disks. 2093ETEXI 2094 2095DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2096 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2097STEXI 2098@item -no-acpi 2099@findex -no-acpi 2100Disable ACPI (Advanced Configuration and Power Interface) support. Use 2101it if your guest OS complains about ACPI problems (PC target machine 2102only). 2103ETEXI 2104 2105DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2106 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2107STEXI 2108@item -no-hpet 2109@findex -no-hpet 2110Disable HPET support. 2111ETEXI 2112 2113DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2114 "-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" 2115 " ACPI table description\n", QEMU_ARCH_I386) 2116STEXI 2117@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}]...] 2118@findex -acpitable 2119Add ACPI table with specified header fields and context from specified files. 2120For file=, take whole ACPI table from the specified files, including all 2121ACPI headers (possible overridden by other options). 2122For data=, only data 2123portion of the table is used, all header information is specified in the 2124command line. 2125If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2126fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2127to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2128spec. 2129ETEXI 2130 2131DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2132 "-smbios file=binary\n" 2133 " load SMBIOS entry from binary file\n" 2134 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2135 " [,uefi=on|off]\n" 2136 " specify SMBIOS type 0 fields\n" 2137 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2138 " [,uuid=uuid][,sku=str][,family=str]\n" 2139 " specify SMBIOS type 1 fields\n" 2140 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2141 " [,asset=str][,location=str]\n" 2142 " specify SMBIOS type 2 fields\n" 2143 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2144 " [,sku=str]\n" 2145 " specify SMBIOS type 3 fields\n" 2146 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2147 " [,asset=str][,part=str]\n" 2148 " specify SMBIOS type 4 fields\n" 2149 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2150 " [,asset=str][,part=str][,speed=%d]\n" 2151 " specify SMBIOS type 17 fields\n", 2152 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2153STEXI 2154@item -smbios file=@var{binary} 2155@findex -smbios 2156Load SMBIOS entry from binary file. 2157 2158@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2159Specify SMBIOS type 0 fields 2160 2161@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}] 2162Specify SMBIOS type 1 fields 2163 2164@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2165Specify SMBIOS type 2 fields 2166 2167@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2168Specify SMBIOS type 3 fields 2169 2170@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2171Specify SMBIOS type 4 fields 2172 2173@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}] 2174Specify SMBIOS type 17 fields 2175ETEXI 2176 2177STEXI 2178@end table 2179ETEXI 2180DEFHEADING() 2181 2182DEFHEADING(Network options:) 2183STEXI 2184@table @option 2185ETEXI 2186 2187DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2188#ifdef CONFIG_SLIRP 2189 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2190 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2191 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2192 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2193 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2194#ifndef _WIN32 2195 "[,smb=dir[,smbserver=addr]]\n" 2196#endif 2197 " configure a user mode network backend with ID 'str',\n" 2198 " its DHCP server and optional services\n" 2199#endif 2200#ifdef _WIN32 2201 "-netdev tap,id=str,ifname=name\n" 2202 " configure a host TAP network backend with ID 'str'\n" 2203#else 2204 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2205 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2206 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2207 " [,poll-us=n]\n" 2208 " configure a host TAP network backend with ID 'str'\n" 2209 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2210 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2211 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2212 " to deconfigure it\n" 2213 " use '[down]script=no' to disable script execution\n" 2214 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2215 " configure it\n" 2216 " use 'fd=h' to connect to an already opened TAP interface\n" 2217 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2218 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2219 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2220 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2221 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2222 " use vhost=on to enable experimental in kernel accelerator\n" 2223 " (only has effect for virtio guests which use MSIX)\n" 2224 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2225 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2226 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2227 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2228 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2229 " spent on busy polling for vhost net\n" 2230 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2231 " configure a host TAP network backend with ID 'str' that is\n" 2232 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2233 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2234#endif 2235#ifdef __linux__ 2236 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2237 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2238 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2239 " [,rxcookie=rxcookie][,offset=offset]\n" 2240 " configure a network backend with ID 'str' connected to\n" 2241 " an Ethernet over L2TPv3 pseudowire.\n" 2242 " Linux kernel 3.3+ as well as most routers can talk\n" 2243 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2244 " VM to a router and even VM to Host. It is a nearly-universal\n" 2245 " standard (RFC3391). Note - this implementation uses static\n" 2246 " pre-configured tunnels (same as the Linux kernel).\n" 2247 " use 'src=' to specify source address\n" 2248 " use 'dst=' to specify destination address\n" 2249 " use 'udp=on' to specify udp encapsulation\n" 2250 " use 'srcport=' to specify source udp port\n" 2251 " use 'dstport=' to specify destination udp port\n" 2252 " use 'ipv6=on' to force v6\n" 2253 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2254 " well as a weak security measure\n" 2255 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2256 " use 'txcookie=0x012345678' to specify a txcookie\n" 2257 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2258 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2259 " use 'pincounter=on' to work around broken counter handling in peer\n" 2260 " use 'offset=X' to add an extra offset between header and data\n" 2261#endif 2262 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2263 " configure a network backend to connect to another network\n" 2264 " using a socket connection\n" 2265 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2266 " configure a network backend to connect to a multicast maddr and port\n" 2267 " use 'localaddr=addr' to specify the host address to send packets from\n" 2268 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2269 " configure a network backend to connect to another network\n" 2270 " using an UDP tunnel\n" 2271#ifdef CONFIG_VDE 2272 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2273 " configure a network backend to connect to port 'n' of a vde switch\n" 2274 " running on host and listening for incoming connections on 'socketpath'.\n" 2275 " Use group 'groupname' and mode 'octalmode' to change default\n" 2276 " ownership and permissions for communication port.\n" 2277#endif 2278#ifdef CONFIG_NETMAP 2279 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2280 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2281 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2282 " netmap device, defaults to '/dev/netmap')\n" 2283#endif 2284#ifdef CONFIG_POSIX 2285 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2286 " configure a vhost-user network, backed by a chardev 'dev'\n" 2287#endif 2288 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2289 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2290DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2291 "-nic [tap|bridge|" 2292#ifdef CONFIG_SLIRP 2293 "user|" 2294#endif 2295#ifdef __linux__ 2296 "l2tpv3|" 2297#endif 2298#ifdef CONFIG_VDE 2299 "vde|" 2300#endif 2301#ifdef CONFIG_NETMAP 2302 "netmap|" 2303#endif 2304#ifdef CONFIG_POSIX 2305 "vhost-user|" 2306#endif 2307 "socket][,option][,...][mac=macaddr]\n" 2308 " initialize an on-board / default host NIC (using MAC address\n" 2309 " macaddr) and connect it to the given host network backend\n" 2310 "-nic none use it alone to have zero network devices (the default is to\n" 2311 " provided a 'user' network connection)\n", 2312 QEMU_ARCH_ALL) 2313DEF("net", HAS_ARG, QEMU_OPTION_net, 2314 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2315 " configure or create an on-board (or machine default) NIC and\n" 2316 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2317 "-net [" 2318#ifdef CONFIG_SLIRP 2319 "user|" 2320#endif 2321 "tap|" 2322 "bridge|" 2323#ifdef CONFIG_VDE 2324 "vde|" 2325#endif 2326#ifdef CONFIG_NETMAP 2327 "netmap|" 2328#endif 2329 "socket][,option][,option][,...]\n" 2330 " old way to initialize a host network interface\n" 2331 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2332STEXI 2333@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2334@findex -nic 2335This option is a shortcut for configuring both the on-board (default) guest 2336NIC hardware and the host network backend in one go. The host backend options 2337are the same as with the corresponding @option{-netdev} options below. 2338The guest NIC model can be set with @option{model=@var{modelname}}. 2339Use @option{model=help} to list the available device types. 2340The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2341 2342The following two example do exactly the same, to show how @option{-nic} can 2343be used to shorten the command line length (note that the e1000 is the default 2344on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2345@example 2346@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2347@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2348@end example 2349 2350@item -nic none 2351Indicate that no network devices should be configured. It is used to override 2352the default configuration (default NIC with ``user'' host network backend) 2353which is activated if no other networking options are provided. 2354 2355@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2356@findex -netdev 2357Configure user mode host network backend which requires no administrator 2358privilege to run. Valid options are: 2359 2360@table @option 2361@item id=@var{id} 2362Assign symbolic name for use in monitor commands. 2363 2364@item ipv4=on|off and ipv6=on|off 2365Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2366both protocols are enabled. 2367 2368@item net=@var{addr}[/@var{mask}] 2369Set IP network address the guest will see. Optionally specify the netmask, 2370either in the form a.b.c.d or as number of valid top-most bits. Default is 237110.0.2.0/24. 2372 2373@item host=@var{addr} 2374Specify the guest-visible address of the host. Default is the 2nd IP in the 2375guest network, i.e. x.x.x.2. 2376 2377@item ipv6-net=@var{addr}[/@var{int}] 2378Set IPv6 network address the guest will see (default is fec0::/64). The 2379network prefix is given in the usual hexadecimal IPv6 address 2380notation. The prefix size is optional, and is given as the number of 2381valid top-most bits (default is 64). 2382 2383@item ipv6-host=@var{addr} 2384Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2385the guest network, i.e. xxxx::2. 2386 2387@item restrict=on|off 2388If this option is enabled, the guest will be isolated, i.e. it will not be 2389able to contact the host and no guest IP packets will be routed over the host 2390to the outside. This option does not affect any explicitly set forwarding rules. 2391 2392@item hostname=@var{name} 2393Specifies the client hostname reported by the built-in DHCP server. 2394 2395@item dhcpstart=@var{addr} 2396Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2397is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2398 2399@item dns=@var{addr} 2400Specify the guest-visible address of the virtual nameserver. The address must 2401be different from the host address. Default is the 3rd IP in the guest network, 2402i.e. x.x.x.3. 2403 2404@item ipv6-dns=@var{addr} 2405Specify the guest-visible address of the IPv6 virtual nameserver. The address 2406must be different from the host address. Default is the 3rd IP in the guest 2407network, i.e. xxxx::3. 2408 2409@item dnssearch=@var{domain} 2410Provides an entry for the domain-search list sent by the built-in 2411DHCP server. More than one domain suffix can be transmitted by specifying 2412this option multiple times. If supported, this will cause the guest to 2413automatically try to append the given domain suffix(es) in case a domain name 2414can not be resolved. 2415 2416Example: 2417@example 2418@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2419@end example 2420 2421@item domainname=@var{domain} 2422Specifies the client domain name reported by the built-in DHCP server. 2423 2424@item tftp=@var{dir} 2425When using the user mode network stack, activate a built-in TFTP 2426server. The files in @var{dir} will be exposed as the root of a TFTP server. 2427The TFTP client on the guest must be configured in binary mode (use the command 2428@code{bin} of the Unix TFTP client). 2429 2430@item tftp-server-name=@var{name} 2431In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 243266). This can be used to advise the guest to load boot files or configurations 2433from a different server than the host address. 2434 2435@item bootfile=@var{file} 2436When using the user mode network stack, broadcast @var{file} as the BOOTP 2437filename. In conjunction with @option{tftp}, this can be used to network boot 2438a guest from a local directory. 2439 2440Example (using pxelinux): 2441@example 2442@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2443 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2444@end example 2445 2446@item smb=@var{dir}[,smbserver=@var{addr}] 2447When using the user mode network stack, activate a built-in SMB 2448server so that Windows OSes can access to the host files in @file{@var{dir}} 2449transparently. The IP address of the SMB server can be set to @var{addr}. By 2450default the 4th IP in the guest network is used, i.e. x.x.x.4. 2451 2452In the guest Windows OS, the line: 2453@example 245410.0.2.4 smbserver 2455@end example 2456must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2457or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2458 2459Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2460 2461Note that a SAMBA server must be installed on the host OS. 2462 2463@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2464Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2465the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2466@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2467given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2468be bound to a specific host interface. If no connection type is set, TCP is 2469used. This option can be given multiple times. 2470 2471For example, to redirect host X11 connection from screen 1 to guest 2472screen 0, use the following: 2473 2474@example 2475# on the host 2476@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2477# this host xterm should open in the guest X11 server 2478xterm -display :1 2479@end example 2480 2481To redirect telnet connections from host port 5555 to telnet port on 2482the guest, use the following: 2483 2484@example 2485# on the host 2486@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2487telnet localhost 5555 2488@end example 2489 2490Then when you use on the host @code{telnet localhost 5555}, you 2491connect to the guest telnet server. 2492 2493@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2494@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2495Forward guest TCP connections to the IP address @var{server} on port @var{port} 2496to the character device @var{dev} or to a program executed by @var{cmd:command} 2497which gets spawned for each connection. This option can be given multiple times. 2498 2499You can either use a chardev directly and have that one used throughout QEMU's 2500lifetime, like in the following example: 2501 2502@example 2503# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2504# the guest accesses it 2505@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2506@end example 2507 2508Or you can execute a command on every TCP connection established by the guest, 2509so that QEMU behaves similar to an inetd process for that virtual server: 2510 2511@example 2512# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2513# and connect the TCP stream to its stdin/stdout 2514@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2515@end example 2516 2517@end table 2518 2519@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2520Configure a host TAP network backend with ID @var{id}. 2521 2522Use the network script @var{file} to configure it and the network script 2523@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2524automatically provides one. The default network configure script is 2525@file{/etc/qemu-ifup} and the default network deconfigure script is 2526@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2527to disable script execution. 2528 2529If running QEMU as an unprivileged user, use the network helper 2530@var{helper} to configure the TAP interface and attach it to the bridge. 2531The default network helper executable is @file{/path/to/qemu-bridge-helper} 2532and the default bridge device is @file{br0}. 2533 2534@option{fd}=@var{h} can be used to specify the handle of an already 2535opened host TAP interface. 2536 2537Examples: 2538 2539@example 2540#launch a QEMU instance with the default network script 2541@value{qemu_system} linux.img -nic tap 2542@end example 2543 2544@example 2545#launch a QEMU instance with two NICs, each one connected 2546#to a TAP device 2547@value{qemu_system} linux.img \ 2548 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2549 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2550@end example 2551 2552@example 2553#launch a QEMU instance with the default network helper to 2554#connect a TAP device to bridge br0 2555@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2556 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2557@end example 2558 2559@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2560Connect a host TAP network interface to a host bridge device. 2561 2562Use the network helper @var{helper} to configure the TAP interface and 2563attach it to the bridge. The default network helper executable is 2564@file{/path/to/qemu-bridge-helper} and the default bridge 2565device is @file{br0}. 2566 2567Examples: 2568 2569@example 2570#launch a QEMU instance with the default network helper to 2571#connect a TAP device to bridge br0 2572@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2573@end example 2574 2575@example 2576#launch a QEMU instance with the default network helper to 2577#connect a TAP device to bridge qemubr0 2578@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2579@end example 2580 2581@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2582 2583This host network backend can be used to connect the guest's network to 2584another QEMU virtual machine using a TCP socket connection. If @option{listen} 2585is specified, QEMU waits for incoming connections on @var{port} 2586(@var{host} is optional). @option{connect} is used to connect to 2587another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2588specifies an already opened TCP socket. 2589 2590Example: 2591@example 2592# launch a first QEMU instance 2593@value{qemu_system} linux.img \ 2594 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2595 -netdev socket,id=n1,listen=:1234 2596# connect the network of this instance to the network of the first instance 2597@value{qemu_system} linux.img \ 2598 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2599 -netdev socket,id=n2,connect=127.0.0.1:1234 2600@end example 2601 2602@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2603 2604Configure a socket host network backend to share the guest's network traffic 2605with another QEMU virtual machines using a UDP multicast socket, effectively 2606making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2607NOTES: 2608@enumerate 2609@item 2610Several QEMU can be running on different hosts and share same bus (assuming 2611correct multicast setup for these hosts). 2612@item 2613mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2614@url{http://user-mode-linux.sf.net}. 2615@item 2616Use @option{fd=h} to specify an already opened UDP multicast socket. 2617@end enumerate 2618 2619Example: 2620@example 2621# launch one QEMU instance 2622@value{qemu_system} linux.img \ 2623 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2624 -netdev socket,id=n1,mcast=230.0.0.1:1234 2625# launch another QEMU instance on same "bus" 2626@value{qemu_system} linux.img \ 2627 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2628 -netdev socket,id=n2,mcast=230.0.0.1:1234 2629# launch yet another QEMU instance on same "bus" 2630@value{qemu_system} linux.img \ 2631 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2632 -netdev socket,id=n3,mcast=230.0.0.1:1234 2633@end example 2634 2635Example (User Mode Linux compat.): 2636@example 2637# launch QEMU instance (note mcast address selected is UML's default) 2638@value{qemu_system} linux.img \ 2639 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2640 -netdev socket,id=n1,mcast=239.192.168.1:1102 2641# launch UML 2642/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2643@end example 2644 2645Example (send packets from host's 1.2.3.4): 2646@example 2647@value{qemu_system} linux.img \ 2648 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2649 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2650@end example 2651 2652@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}] 2653Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2654popular protocol to transport Ethernet (and other Layer 2) data frames between 2655two systems. It is present in routers, firewalls and the Linux kernel 2656(from version 3.3 onwards). 2657 2658This transport allows a VM to communicate to another VM, router or firewall directly. 2659 2660@table @option 2661@item src=@var{srcaddr} 2662 source address (mandatory) 2663@item dst=@var{dstaddr} 2664 destination address (mandatory) 2665@item udp 2666 select udp encapsulation (default is ip). 2667@item srcport=@var{srcport} 2668 source udp port. 2669@item dstport=@var{dstport} 2670 destination udp port. 2671@item ipv6 2672 force v6, otherwise defaults to v4. 2673@item rxcookie=@var{rxcookie} 2674@itemx txcookie=@var{txcookie} 2675 Cookies are a weak form of security in the l2tpv3 specification. 2676Their function is mostly to prevent misconfiguration. By default they are 32 2677bit. 2678@item cookie64 2679 Set cookie size to 64 bit instead of the default 32 2680@item counter=off 2681 Force a 'cut-down' L2TPv3 with no counter as in 2682draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2683@item pincounter=on 2684 Work around broken counter handling in peer. This may also help on 2685networks which have packet reorder. 2686@item offset=@var{offset} 2687 Add an extra offset between header and data 2688@end table 2689 2690For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2691on the remote Linux host 1.2.3.4: 2692@example 2693# Setup tunnel on linux host using raw ip as encapsulation 2694# on 1.2.3.4 2695ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2696 encap udp udp_sport 16384 udp_dport 16384 2697ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2698 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2699ifconfig vmtunnel0 mtu 1500 2700ifconfig vmtunnel0 up 2701brctl addif br-lan vmtunnel0 2702 2703 2704# on 4.3.2.1 2705# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2706 2707@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2708 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2709 2710@end example 2711 2712@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2713Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2714listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2715and MODE @var{octalmode} to change default ownership and permissions for 2716communication port. This option is only available if QEMU has been compiled 2717with vde support enabled. 2718 2719Example: 2720@example 2721# launch vde switch 2722vde_switch -F -sock /tmp/myswitch 2723# launch QEMU instance 2724@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2725@end example 2726 2727@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2728 2729Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2730be a unix domain socket backed one. The vhost-user uses a specifically defined 2731protocol to pass vhost ioctl replacement messages to an application on the other 2732end of the socket. On non-MSIX guests, the feature can be forced with 2733@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2734be created for multiqueue vhost-user. 2735 2736Example: 2737@example 2738qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2739 -numa node,memdev=mem \ 2740 -chardev socket,id=chr0,path=/path/to/socket \ 2741 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2742 -device virtio-net-pci,netdev=net0 2743@end example 2744 2745@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2746 2747Create a hub port on the emulated hub with ID @var{hubid}. 2748 2749The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2750single netdev. Alternatively, you can also connect the hubport to another 2751netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2752 2753@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2754@findex -net 2755Legacy option to configure or create an on-board (or machine default) Network 2756Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2757the default hub), or to the netdev @var{nd}. 2758The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2759can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2760only), and a @var{name} can be assigned for use in monitor commands. 2761Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2762that the card should have; this option currently only affects virtio cards; set 2763@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2764NIC is created. QEMU can emulate several different models of network card. 2765Use @code{-net nic,model=help} for a list of available devices for your target. 2766 2767@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2768Configure a host network backend (with the options corresponding to the same 2769@option{-netdev} option) and connect it to the emulated hub 0 (the default 2770hub). Use @var{name} to specify the name of the hub port. 2771ETEXI 2772 2773STEXI 2774@end table 2775ETEXI 2776DEFHEADING() 2777 2778DEFHEADING(Character device options:) 2779 2780DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2781 "-chardev help\n" 2782 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2783 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2784 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2785 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2786 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2787 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2788 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2789 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2790 " [,logfile=PATH][,logappend=on|off]\n" 2791 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2792 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2793 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2794 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2795 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2796 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2797#ifdef _WIN32 2798 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2799 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2800#else 2801 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2802 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2803#endif 2804#ifdef CONFIG_BRLAPI 2805 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2806#endif 2807#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2808 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2809 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2810 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2811#endif 2812#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2813 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2814 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2815#endif 2816#if defined(CONFIG_SPICE) 2817 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2818 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2819#endif 2820 , QEMU_ARCH_ALL 2821) 2822 2823STEXI 2824 2825The general form of a character device option is: 2826@table @option 2827@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2828@findex -chardev 2829Backend is one of: 2830@option{null}, 2831@option{socket}, 2832@option{udp}, 2833@option{msmouse}, 2834@option{vc}, 2835@option{ringbuf}, 2836@option{file}, 2837@option{pipe}, 2838@option{console}, 2839@option{serial}, 2840@option{pty}, 2841@option{stdio}, 2842@option{braille}, 2843@option{tty}, 2844@option{parallel}, 2845@option{parport}, 2846@option{spicevmc}, 2847@option{spiceport}. 2848The specific backend will determine the applicable options. 2849 2850Use @code{-chardev help} to print all available chardev backend types. 2851 2852All devices must have an id, which can be any string up to 127 characters long. 2853It is used to uniquely identify this device in other command line directives. 2854 2855A character device may be used in multiplexing mode by multiple front-ends. 2856Specify @option{mux=on} to enable this mode. 2857A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2858backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2859If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2860create a multiplexer with your specified ID, and you can then configure multiple 2861front ends to use that chardev ID for their input/output. Up to four different 2862front ends can be connected to a single multiplexed chardev. (Without 2863multiplexing enabled, a chardev can only be used by a single front end.) 2864For instance you could use this to allow a single stdio chardev to be used by 2865two serial ports and the QEMU monitor: 2866 2867@example 2868-chardev stdio,mux=on,id=char0 \ 2869-mon chardev=char0,mode=readline \ 2870-serial chardev:char0 \ 2871-serial chardev:char0 2872@end example 2873 2874You can have more than one multiplexer in a system configuration; for instance 2875you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2876multiplexed between the QEMU monitor and a parallel port: 2877 2878@example 2879-chardev stdio,mux=on,id=char0 \ 2880-mon chardev=char0,mode=readline \ 2881-parallel chardev:char0 \ 2882-chardev tcp,...,mux=on,id=char1 \ 2883-serial chardev:char1 \ 2884-serial chardev:char1 2885@end example 2886 2887When you're using a multiplexed character device, some escape sequences are 2888interpreted in the input. @xref{mux_keys, Keys in the character backend 2889multiplexer}. 2890 2891Note that some other command line options may implicitly create multiplexed 2892character backends; for instance @option{-serial mon:stdio} creates a 2893multiplexed stdio backend connected to the serial port and the QEMU monitor, 2894and @option{-nographic} also multiplexes the console and the monitor to 2895stdio. 2896 2897There is currently no support for multiplexing in the other direction 2898(where a single QEMU front end takes input and output from multiple chardevs). 2899 2900Every backend supports the @option{logfile} option, which supplies the path 2901to a file to record all data transmitted via the backend. The @option{logappend} 2902option controls whether the log file will be truncated or appended to when 2903opened. 2904 2905@end table 2906 2907The available backends are: 2908 2909@table @option 2910@item -chardev null,id=@var{id} 2911A void device. This device will not emit any data, and will drop any data it 2912receives. The null backend does not take any options. 2913 2914@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}] 2915 2916Create a two-way stream socket, which can be either a TCP or a unix socket. A 2917unix socket will be created if @option{path} is specified. Behaviour is 2918undefined if TCP options are specified for a unix socket. 2919 2920@option{server} specifies that the socket shall be a listening socket. 2921 2922@option{nowait} specifies that QEMU should not block waiting for a client to 2923connect to a listening socket. 2924 2925@option{telnet} specifies that traffic on the socket should interpret telnet 2926escape sequences. 2927 2928@option{websocket} specifies that the socket uses WebSocket protocol for 2929communication. 2930 2931@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2932the remote end goes away. qemu will delay this many seconds and then attempt 2933to reconnect. Zero disables reconnecting, and is the default. 2934 2935@option{tls-creds} requests enablement of the TLS protocol for encryption, 2936and specifies the id of the TLS credentials to use for the handshake. The 2937credentials must be previously created with the @option{-object tls-creds} 2938argument. 2939 2940@option{tls-auth} provides the ID of the QAuthZ authorization object against 2941which the client's x509 distinguished name will be validated. This object is 2942only resolved at time of use, so can be deleted and recreated on the fly 2943while the chardev server is active. If missing, it will default to denying 2944access. 2945 2946TCP and unix socket options are given below: 2947 2948@table @option 2949 2950@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2951 2952@option{host} for a listening socket specifies the local address to be bound. 2953For a connecting socket species the remote host to connect to. @option{host} is 2954optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2955 2956@option{port} for a listening socket specifies the local port to be bound. For a 2957connecting socket specifies the port on the remote host to connect to. 2958@option{port} can be given as either a port number or a service name. 2959@option{port} is required. 2960 2961@option{to} is only relevant to listening sockets. If it is specified, and 2962@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2963to and including @option{to} until it succeeds. @option{to} must be specified 2964as a port number. 2965 2966@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2967If neither is specified the socket may use either protocol. 2968 2969@option{nodelay} disables the Nagle algorithm. 2970 2971@item unix options: path=@var{path} 2972 2973@option{path} specifies the local path of the unix socket. @option{path} is 2974required. 2975 2976@end table 2977 2978@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2979 2980Sends all traffic from the guest to a remote host over UDP. 2981 2982@option{host} specifies the remote host to connect to. If not specified it 2983defaults to @code{localhost}. 2984 2985@option{port} specifies the port on the remote host to connect to. @option{port} 2986is required. 2987 2988@option{localaddr} specifies the local address to bind to. If not specified it 2989defaults to @code{0.0.0.0}. 2990 2991@option{localport} specifies the local port to bind to. If not specified any 2992available local port will be used. 2993 2994@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2995If neither is specified the device may use either protocol. 2996 2997@item -chardev msmouse,id=@var{id} 2998 2999Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 3000take any options. 3001 3002@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 3003 3004Connect to a QEMU text console. @option{vc} may optionally be given a specific 3005size. 3006 3007@option{width} and @option{height} specify the width and height respectively of 3008the console, in pixels. 3009 3010@option{cols} and @option{rows} specify that the console be sized to fit a text 3011console with the given dimensions. 3012 3013@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 3014 3015Create a ring buffer with fixed size @option{size}. 3016@var{size} must be a power of two and defaults to @code{64K}. 3017 3018@item -chardev file,id=@var{id},path=@var{path} 3019 3020Log all traffic received from the guest to a file. 3021 3022@option{path} specifies the path of the file to be opened. This file will be 3023created if it does not already exist, and overwritten if it does. @option{path} 3024is required. 3025 3026@item -chardev pipe,id=@var{id},path=@var{path} 3027 3028Create a two-way connection to the guest. The behaviour differs slightly between 3029Windows hosts and other hosts: 3030 3031On Windows, a single duplex pipe will be created at 3032@file{\\.pipe\@option{path}}. 3033 3034On other hosts, 2 pipes will be created called @file{@option{path}.in} and 3035@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 3036received by the guest. Data written by the guest can be read from 3037@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 3038be present. 3039 3040@option{path} forms part of the pipe path as described above. @option{path} is 3041required. 3042 3043@item -chardev console,id=@var{id} 3044 3045Send traffic from the guest to QEMU's standard output. @option{console} does not 3046take any options. 3047 3048@option{console} is only available on Windows hosts. 3049 3050@item -chardev serial,id=@var{id},path=@option{path} 3051 3052Send traffic from the guest to a serial device on the host. 3053 3054On Unix hosts serial will actually accept any tty device, 3055not only serial lines. 3056 3057@option{path} specifies the name of the serial device to open. 3058 3059@item -chardev pty,id=@var{id} 3060 3061Create a new pseudo-terminal on the host and connect to it. @option{pty} does 3062not take any options. 3063 3064@option{pty} is not available on Windows hosts. 3065 3066@item -chardev stdio,id=@var{id}[,signal=on|off] 3067Connect to standard input and standard output of the QEMU process. 3068 3069@option{signal} controls if signals are enabled on the terminal, that includes 3070exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3071default, use @option{signal=off} to disable it. 3072 3073@item -chardev braille,id=@var{id} 3074 3075Connect to a local BrlAPI server. @option{braille} does not take any options. 3076 3077@item -chardev tty,id=@var{id},path=@var{path} 3078 3079@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3080DragonFlyBSD hosts. It is an alias for @option{serial}. 3081 3082@option{path} specifies the path to the tty. @option{path} is required. 3083 3084@item -chardev parallel,id=@var{id},path=@var{path} 3085@itemx -chardev parport,id=@var{id},path=@var{path} 3086 3087@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3088 3089Connect to a local parallel port. 3090 3091@option{path} specifies the path to the parallel port device. @option{path} is 3092required. 3093 3094@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3095 3096@option{spicevmc} is only available when spice support is built in. 3097 3098@option{debug} debug level for spicevmc 3099 3100@option{name} name of spice channel to connect to 3101 3102Connect to a spice virtual machine channel, such as vdiport. 3103 3104@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3105 3106@option{spiceport} is only available when spice support is built in. 3107 3108@option{debug} debug level for spicevmc 3109 3110@option{name} name of spice port to connect to 3111 3112Connect to a spice port, allowing a Spice client to handle the traffic 3113identified by a name (preferably a fqdn). 3114ETEXI 3115 3116STEXI 3117@end table 3118ETEXI 3119DEFHEADING() 3120 3121#ifdef CONFIG_TPM 3122DEFHEADING(TPM device options:) 3123 3124DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3125 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3126 " use path to provide path to a character device; default is /dev/tpm0\n" 3127 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3128 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3129 "-tpmdev emulator,id=id,chardev=dev\n" 3130 " configure the TPM device using chardev backend\n", 3131 QEMU_ARCH_ALL) 3132STEXI 3133 3134The general form of a TPM device option is: 3135@table @option 3136 3137@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3138@findex -tpmdev 3139 3140The specific backend type will determine the applicable options. 3141The @code{-tpmdev} option creates the TPM backend and requires a 3142@code{-device} option that specifies the TPM frontend interface model. 3143 3144Use @code{-tpmdev help} to print all available TPM backend types. 3145 3146@end table 3147 3148The available backends are: 3149 3150@table @option 3151 3152@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3153 3154(Linux-host only) Enable access to the host's TPM using the passthrough 3155driver. 3156 3157@option{path} specifies the path to the host's TPM device, i.e., on 3158a Linux host this would be @code{/dev/tpm0}. 3159@option{path} is optional and by default @code{/dev/tpm0} is used. 3160 3161@option{cancel-path} specifies the path to the host TPM device's sysfs 3162entry allowing for cancellation of an ongoing TPM command. 3163@option{cancel-path} is optional and by default QEMU will search for the 3164sysfs entry to use. 3165 3166Some notes about using the host's TPM with the passthrough driver: 3167 3168The TPM device accessed by the passthrough driver must not be 3169used by any other application on the host. 3170 3171Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3172the VM's firmware (BIOS/UEFI) will not be able to initialize the 3173TPM again and may therefore not show a TPM-specific menu that would 3174otherwise allow the user to configure the TPM, e.g., allow the user to 3175enable/disable or activate/deactivate the TPM. 3176Further, if TPM ownership is released from within a VM then the host's TPM 3177will get disabled and deactivated. To enable and activate the 3178TPM again afterwards, the host has to be rebooted and the user is 3179required to enter the firmware's menu to enable and activate the TPM. 3180If the TPM is left disabled and/or deactivated most TPM commands will fail. 3181 3182To create a passthrough TPM use the following two options: 3183@example 3184-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3185@end example 3186Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3187@code{tpmdev=tpm0} in the device option. 3188 3189@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3190 3191(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3192chardev backend. 3193 3194@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3195 3196To create a TPM emulator backend device with chardev socket backend: 3197@example 3198 3199-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3200 3201@end example 3202 3203ETEXI 3204 3205STEXI 3206@end table 3207ETEXI 3208DEFHEADING() 3209 3210#endif 3211 3212DEFHEADING(Linux/Multiboot boot specific:) 3213STEXI 3214 3215When using these options, you can use a given Linux or Multiboot 3216kernel without installing it in the disk image. It can be useful 3217for easier testing of various kernels. 3218 3219@table @option 3220ETEXI 3221 3222DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3223 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3224STEXI 3225@item -kernel @var{bzImage} 3226@findex -kernel 3227Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3228or in multiboot format. 3229ETEXI 3230 3231DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3232 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3233STEXI 3234@item -append @var{cmdline} 3235@findex -append 3236Use @var{cmdline} as kernel command line 3237ETEXI 3238 3239DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3240 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3241STEXI 3242@item -initrd @var{file} 3243@findex -initrd 3244Use @var{file} as initial ram disk. 3245 3246@item -initrd "@var{file1} arg=foo,@var{file2}" 3247 3248This syntax is only available with multiboot. 3249 3250Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3251first module. 3252ETEXI 3253 3254DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3255 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3256STEXI 3257@item -dtb @var{file} 3258@findex -dtb 3259Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3260on boot. 3261ETEXI 3262 3263STEXI 3264@end table 3265ETEXI 3266DEFHEADING() 3267 3268DEFHEADING(Debug/Expert options:) 3269STEXI 3270@table @option 3271ETEXI 3272 3273DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3274 "-fw_cfg [name=]<name>,file=<file>\n" 3275 " add named fw_cfg entry with contents from file\n" 3276 "-fw_cfg [name=]<name>,string=<str>\n" 3277 " add named fw_cfg entry with contents from string\n", 3278 QEMU_ARCH_ALL) 3279STEXI 3280 3281@item -fw_cfg [name=]@var{name},file=@var{file} 3282@findex -fw_cfg 3283Add named fw_cfg entry with contents from file @var{file}. 3284 3285@item -fw_cfg [name=]@var{name},string=@var{str} 3286Add named fw_cfg entry with contents from string @var{str}. 3287 3288The terminating NUL character of the contents of @var{str} will not be 3289included as part of the fw_cfg item data. To insert contents with 3290embedded NUL characters, you have to use the @var{file} parameter. 3291 3292The fw_cfg entries are passed by QEMU through to the guest. 3293 3294Example: 3295@example 3296 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3297@end example 3298creates an fw_cfg entry named opt/com.mycompany/blob with contents 3299from ./my_blob.bin. 3300 3301ETEXI 3302 3303DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3304 "-serial dev redirect the serial port to char device 'dev'\n", 3305 QEMU_ARCH_ALL) 3306STEXI 3307@item -serial @var{dev} 3308@findex -serial 3309Redirect the virtual serial port to host character device 3310@var{dev}. The default device is @code{vc} in graphical mode and 3311@code{stdio} in non graphical mode. 3312 3313This option can be used several times to simulate up to 4 serial 3314ports. 3315 3316Use @code{-serial none} to disable all serial ports. 3317 3318Available character devices are: 3319@table @option 3320@item vc[:@var{W}x@var{H}] 3321Virtual console. Optionally, a width and height can be given in pixel with 3322@example 3323vc:800x600 3324@end example 3325It is also possible to specify width or height in characters: 3326@example 3327vc:80Cx24C 3328@end example 3329@item pty 3330[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3331@item none 3332No device is allocated. 3333@item null 3334void device 3335@item chardev:@var{id} 3336Use a named character device defined with the @code{-chardev} option. 3337@item /dev/XXX 3338[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3339parameters are set according to the emulated ones. 3340@item /dev/parport@var{N} 3341[Linux only, parallel port only] Use host parallel port 3342@var{N}. Currently SPP and EPP parallel port features can be used. 3343@item file:@var{filename} 3344Write output to @var{filename}. No character can be read. 3345@item stdio 3346[Unix only] standard input/output 3347@item pipe:@var{filename} 3348name pipe @var{filename} 3349@item COM@var{n} 3350[Windows only] Use host serial port @var{n} 3351@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3352This implements UDP Net Console. 3353When @var{remote_host} or @var{src_ip} are not specified 3354they default to @code{0.0.0.0}. 3355When not using a specified @var{src_port} a random port is automatically chosen. 3356 3357If you just want a simple readonly console you can use @code{netcat} or 3358@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3359@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3360will appear in the netconsole session. 3361 3362If you plan to send characters back via netconsole or you want to stop 3363and start QEMU a lot of times, you should have QEMU use the same 3364source port each time by using something like @code{-serial 3365udp::4555@@:4556} to QEMU. Another approach is to use a patched 3366version of netcat which can listen to a TCP port and send and receive 3367characters via udp. If you have a patched version of netcat which 3368activates telnet remote echo and single char transfer, then you can 3369use the following options to set up a netcat redirector to allow 3370telnet on port 5555 to access the QEMU port. 3371@table @code 3372@item QEMU Options: 3373-serial udp::4555@@:4556 3374@item netcat options: 3375-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3376@item telnet options: 3377localhost 5555 3378@end table 3379 3380@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3381The TCP Net Console has two modes of operation. It can send the serial 3382I/O to a location or wait for a connection from a location. By default 3383the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3384the @var{server} option QEMU will wait for a client socket application 3385to connect to the port before continuing, unless the @code{nowait} 3386option was specified. The @code{nodelay} option disables the Nagle buffering 3387algorithm. The @code{reconnect} option only applies if @var{noserver} is 3388set, if the connection goes down it will attempt to reconnect at the 3389given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3390one TCP connection at a time is accepted. You can use @code{telnet} to 3391connect to the corresponding character device. 3392@table @code 3393@item Example to send tcp console to 192.168.0.2 port 4444 3394-serial tcp:192.168.0.2:4444 3395@item Example to listen and wait on port 4444 for connection 3396-serial tcp::4444,server 3397@item Example to not wait and listen on ip 192.168.0.100 port 4444 3398-serial tcp:192.168.0.100:4444,server,nowait 3399@end table 3400 3401@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3402The telnet protocol is used instead of raw tcp sockets. The options 3403work the same as if you had specified @code{-serial tcp}. The 3404difference is that the port acts like a telnet server or client using 3405telnet option negotiation. This will also allow you to send the 3406MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3407sequence. Typically in unix telnet you do it with Control-] and then 3408type "send break" followed by pressing the enter key. 3409 3410@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3411The WebSocket protocol is used instead of raw tcp socket. The port acts as 3412a WebSocket server. Client mode is not supported. 3413 3414@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3415A unix domain socket is used instead of a tcp socket. The option works the 3416same as if you had specified @code{-serial tcp} except the unix domain socket 3417@var{path} is used for connections. 3418 3419@item mon:@var{dev_string} 3420This is a special option to allow the monitor to be multiplexed onto 3421another serial port. The monitor is accessed with key sequence of 3422@key{Control-a} and then pressing @key{c}. 3423@var{dev_string} should be any one of the serial devices specified 3424above. An example to multiplex the monitor onto a telnet server 3425listening on port 4444 would be: 3426@table @code 3427@item -serial mon:telnet::4444,server,nowait 3428@end table 3429When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3430QEMU any more but will be passed to the guest instead. 3431 3432@item braille 3433Braille device. This will use BrlAPI to display the braille output on a real 3434or fake device. 3435 3436@item msmouse 3437Three button serial mouse. Configure the guest to use Microsoft protocol. 3438@end table 3439ETEXI 3440 3441DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3442 "-parallel dev redirect the parallel port to char device 'dev'\n", 3443 QEMU_ARCH_ALL) 3444STEXI 3445@item -parallel @var{dev} 3446@findex -parallel 3447Redirect the virtual parallel port to host device @var{dev} (same 3448devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3449be used to use hardware devices connected on the corresponding host 3450parallel port. 3451 3452This option can be used several times to simulate up to 3 parallel 3453ports. 3454 3455Use @code{-parallel none} to disable all parallel ports. 3456ETEXI 3457 3458DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3459 "-monitor dev redirect the monitor to char device 'dev'\n", 3460 QEMU_ARCH_ALL) 3461STEXI 3462@item -monitor @var{dev} 3463@findex -monitor 3464Redirect the monitor to host device @var{dev} (same devices as the 3465serial port). 3466The default device is @code{vc} in graphical mode and @code{stdio} in 3467non graphical mode. 3468Use @code{-monitor none} to disable the default monitor. 3469ETEXI 3470DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3471 "-qmp dev like -monitor but opens in 'control' mode\n", 3472 QEMU_ARCH_ALL) 3473STEXI 3474@item -qmp @var{dev} 3475@findex -qmp 3476Like -monitor but opens in 'control' mode. 3477ETEXI 3478DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3479 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3480 QEMU_ARCH_ALL) 3481STEXI 3482@item -qmp-pretty @var{dev} 3483@findex -qmp-pretty 3484Like -qmp but uses pretty JSON formatting. 3485ETEXI 3486 3487DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3488 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3489STEXI 3490@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3491@findex -mon 3492Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3493easing human reading and debugging. 3494ETEXI 3495 3496DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3497 "-debugcon dev redirect the debug console to char device 'dev'\n", 3498 QEMU_ARCH_ALL) 3499STEXI 3500@item -debugcon @var{dev} 3501@findex -debugcon 3502Redirect the debug console to host device @var{dev} (same devices as the 3503serial port). The debug console is an I/O port which is typically port 35040xe9; writing to that I/O port sends output to this device. 3505The default device is @code{vc} in graphical mode and @code{stdio} in 3506non graphical mode. 3507ETEXI 3508 3509DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3510 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3511STEXI 3512@item -pidfile @var{file} 3513@findex -pidfile 3514Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3515from a script. 3516ETEXI 3517 3518DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3519 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3520STEXI 3521@item -singlestep 3522@findex -singlestep 3523Run the emulation in single step mode. 3524ETEXI 3525 3526DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3527 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3528 QEMU_ARCH_ALL) 3529STEXI 3530@item --preconfig 3531@findex --preconfig 3532Pause QEMU for interactive configuration before the machine is created, 3533which allows querying and configuring properties that will affect 3534machine initialization. Use QMP command 'x-exit-preconfig' to exit 3535the preconfig state and move to the next state (i.e. run guest if -S 3536isn't used or pause the second time if -S is used). This option is 3537experimental. 3538ETEXI 3539 3540DEF("S", 0, QEMU_OPTION_S, \ 3541 "-S freeze CPU at startup (use 'c' to start execution)\n", 3542 QEMU_ARCH_ALL) 3543STEXI 3544@item -S 3545@findex -S 3546Do not start CPU at startup (you must type 'c' in the monitor). 3547ETEXI 3548 3549DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3550 "-realtime [mlock=on|off]\n" 3551 " run qemu with realtime features\n" 3552 " mlock=on|off controls mlock support (default: on)\n", 3553 QEMU_ARCH_ALL) 3554STEXI 3555@item -realtime mlock=on|off 3556@findex -realtime 3557Run qemu with realtime features. 3558mlocking qemu and guest memory can be enabled via @option{mlock=on} 3559(enabled by default). 3560ETEXI 3561 3562DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3563 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3564 " run qemu with overcommit hints\n" 3565 " mem-lock=on|off controls memory lock support (default: off)\n" 3566 " cpu-pm=on|off controls cpu power management (default: off)\n", 3567 QEMU_ARCH_ALL) 3568STEXI 3569@item -overcommit mem-lock=on|off 3570@item -overcommit cpu-pm=on|off 3571@findex -overcommit 3572Run qemu with hints about host resource overcommit. The default is 3573to assume that host overcommits all resources. 3574 3575Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3576by default). This works when host memory is not overcommitted and reduces the 3577worst-case latency for guest. This is equivalent to @option{realtime}. 3578 3579Guest ability to manage power state of host cpus (increasing latency for other 3580processes on the same host cpu, but decreasing latency for guest) can be 3581enabled via @option{cpu-pm=on} (disabled by default). This works best when 3582host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3583utilization will be incorrect, not taking into account guest idle time. 3584ETEXI 3585 3586DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3587 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3588STEXI 3589@item -gdb @var{dev} 3590@findex -gdb 3591Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3592connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3593stdio are reasonable use case. The latter is allowing to start QEMU from 3594within gdb and establish the connection via a pipe: 3595@example 3596(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3597@end example 3598ETEXI 3599 3600DEF("s", 0, QEMU_OPTION_s, \ 3601 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3602 QEMU_ARCH_ALL) 3603STEXI 3604@item -s 3605@findex -s 3606Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3607(@pxref{gdb_usage}). 3608ETEXI 3609 3610DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3611 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3612 QEMU_ARCH_ALL) 3613STEXI 3614@item -d @var{item1}[,...] 3615@findex -d 3616Enable logging of specified items. Use '-d help' for a list of log items. 3617ETEXI 3618 3619DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3620 "-D logfile output log to logfile (default stderr)\n", 3621 QEMU_ARCH_ALL) 3622STEXI 3623@item -D @var{logfile} 3624@findex -D 3625Output log in @var{logfile} instead of to stderr 3626ETEXI 3627 3628DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3629 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3630 QEMU_ARCH_ALL) 3631STEXI 3632@item -dfilter @var{range1}[,...] 3633@findex -dfilter 3634Filter debug output to that relevant to a range of target addresses. The filter 3635spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3636@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3637addresses and sizes required. For example: 3638@example 3639 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3640@end example 3641Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3642the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3643block starting at 0xffffffc00005f000. 3644ETEXI 3645 3646DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3647 "-seed number seed the pseudo-random number generator\n", 3648 QEMU_ARCH_ALL) 3649STEXI 3650@item -seed @var{number} 3651@findex -seed 3652Force the guest to use a deterministic pseudo-random number generator, seeded 3653with @var{number}. This does not affect crypto routines within the host. 3654ETEXI 3655 3656DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3657 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3658 QEMU_ARCH_ALL) 3659STEXI 3660@item -L @var{path} 3661@findex -L 3662Set the directory for the BIOS, VGA BIOS and keymaps. 3663 3664To list all the data directories, use @code{-L help}. 3665ETEXI 3666 3667DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3668 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3669STEXI 3670@item -bios @var{file} 3671@findex -bios 3672Set the filename for the BIOS. 3673ETEXI 3674 3675DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3676 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3677STEXI 3678@item -enable-kvm 3679@findex -enable-kvm 3680Enable KVM full virtualization support. This option is only available 3681if KVM support is enabled when compiling. 3682ETEXI 3683 3684DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3685 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3686DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3687 "-xen-attach attach to existing xen domain\n" 3688 " libxl will use this when starting QEMU\n", 3689 QEMU_ARCH_ALL) 3690DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3691 "-xen-domid-restrict restrict set of available xen operations\n" 3692 " to specified domain id. (Does not affect\n" 3693 " xenpv machine type).\n", 3694 QEMU_ARCH_ALL) 3695STEXI 3696@item -xen-domid @var{id} 3697@findex -xen-domid 3698Specify xen guest domain @var{id} (XEN only). 3699@item -xen-attach 3700@findex -xen-attach 3701Attach to existing xen domain. 3702libxl will use this when starting QEMU (XEN only). 3703@findex -xen-domid-restrict 3704Restrict set of available xen operations to specified domain id (XEN only). 3705ETEXI 3706 3707DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3708 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3709STEXI 3710@item -no-reboot 3711@findex -no-reboot 3712Exit instead of rebooting. 3713ETEXI 3714 3715DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3716 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3717STEXI 3718@item -no-shutdown 3719@findex -no-shutdown 3720Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3721This allows for instance switching to monitor to commit changes to the 3722disk image. 3723ETEXI 3724 3725DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3726 "-loadvm [tag|id]\n" \ 3727 " start right away with a saved state (loadvm in monitor)\n", 3728 QEMU_ARCH_ALL) 3729STEXI 3730@item -loadvm @var{file} 3731@findex -loadvm 3732Start right away with a saved state (@code{loadvm} in monitor) 3733ETEXI 3734 3735#ifndef _WIN32 3736DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3737 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3738#endif 3739STEXI 3740@item -daemonize 3741@findex -daemonize 3742Daemonize the QEMU process after initialization. QEMU will not detach from 3743standard IO until it is ready to receive connections on any of its devices. 3744This option is a useful way for external programs to launch QEMU without having 3745to cope with initialization race conditions. 3746ETEXI 3747 3748DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3749 "-option-rom rom load a file, rom, into the option ROM space\n", 3750 QEMU_ARCH_ALL) 3751STEXI 3752@item -option-rom @var{file} 3753@findex -option-rom 3754Load the contents of @var{file} as an option ROM. 3755This option is useful to load things like EtherBoot. 3756ETEXI 3757 3758DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3759 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3760 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3761 QEMU_ARCH_ALL) 3762 3763STEXI 3764 3765@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3766@findex -rtc 3767Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3768UTC or local time, respectively. @code{localtime} is required for correct date in 3769MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3770format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3771 3772By default the RTC is driven by the host system time. This allows using of the 3773RTC as accurate reference clock inside the guest, specifically if the host 3774time is smoothly following an accurate external reference clock, e.g. via NTP. 3775If you want to isolate the guest time from the host, you can set @option{clock} 3776to @code{rt} instead, which provides a host monotonic clock if host support it. 3777To even prevent the RTC from progressing during suspension, you can set @option{clock} 3778to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3779icount mode in order to preserve determinism; however, note that in icount mode 3780the speed of the virtual clock is variable and can in general differ from the 3781host clock. 3782 3783Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3784specifically with Windows' ACPI HAL. This option will try to figure out how 3785many timer interrupts were not processed by the Windows guest and will 3786re-inject them. 3787ETEXI 3788 3789DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3790 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3791 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3792 " instruction, enable aligning the host and virtual clocks\n" \ 3793 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3794STEXI 3795@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3796@findex -icount 3797Enable virtual instruction counter. The virtual cpu will execute one 3798instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3799then the virtual cpu speed will be automatically adjusted to keep virtual 3800time within a few seconds of real time. 3801 3802When the virtual cpu is sleeping, the virtual time will advance at default 3803speed unless @option{sleep=on|off} is specified. 3804With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3805instantly whenever the virtual cpu goes to sleep mode and will not advance 3806if no timer is enabled. This behavior give deterministic execution times from 3807the guest point of view. 3808 3809Note that while this option can give deterministic behavior, it does not 3810provide cycle accurate emulation. Modern CPUs contain superscalar out of 3811order cores with complex cache hierarchies. The number of instructions 3812executed often has little or no correlation with actual performance. 3813 3814@option{align=on} will activate the delay algorithm which will try 3815to synchronise the host clock and the virtual clock. The goal is to 3816have a guest running at the real frequency imposed by the shift option. 3817Whenever the guest clock is behind the host clock and if 3818@option{align=on} is specified then we print a message to the user 3819to inform about the delay. 3820Currently this option does not work when @option{shift} is @code{auto}. 3821Note: The sync algorithm will work for those shift values for which 3822the guest clock runs ahead of the host clock. Typically this happens 3823when the shift value is high (how high depends on the host machine). 3824 3825When @option{rr} option is specified deterministic record/replay is enabled. 3826Replay log is written into @var{filename} file in record mode and 3827read from this file in replay mode. 3828 3829Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3830at the start of execution recording. In replay mode this option is used 3831to load the initial VM state. 3832ETEXI 3833 3834DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3835 "-watchdog model\n" \ 3836 " enable virtual hardware watchdog [default=none]\n", 3837 QEMU_ARCH_ALL) 3838STEXI 3839@item -watchdog @var{model} 3840@findex -watchdog 3841Create a virtual hardware watchdog device. Once enabled (by a guest 3842action), the watchdog must be periodically polled by an agent inside 3843the guest or else the guest will be restarted. Choose a model for 3844which your guest has drivers. 3845 3846The @var{model} is the model of hardware watchdog to emulate. Use 3847@code{-watchdog help} to list available hardware models. Only one 3848watchdog can be enabled for a guest. 3849 3850The following models may be available: 3851@table @option 3852@item ib700 3853iBASE 700 is a very simple ISA watchdog with a single timer. 3854@item i6300esb 3855Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3856dual-timer watchdog. 3857@item diag288 3858A virtual watchdog for s390x backed by the diagnose 288 hypercall 3859(currently KVM only). 3860@end table 3861ETEXI 3862 3863DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3864 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3865 " action when watchdog fires [default=reset]\n", 3866 QEMU_ARCH_ALL) 3867STEXI 3868@item -watchdog-action @var{action} 3869@findex -watchdog-action 3870 3871The @var{action} controls what QEMU will do when the watchdog timer 3872expires. 3873The default is 3874@code{reset} (forcefully reset the guest). 3875Other possible actions are: 3876@code{shutdown} (attempt to gracefully shutdown the guest), 3877@code{poweroff} (forcefully poweroff the guest), 3878@code{inject-nmi} (inject a NMI into the guest), 3879@code{pause} (pause the guest), 3880@code{debug} (print a debug message and continue), or 3881@code{none} (do nothing). 3882 3883Note that the @code{shutdown} action requires that the guest responds 3884to ACPI signals, which it may not be able to do in the sort of 3885situations where the watchdog would have expired, and thus 3886@code{-watchdog-action shutdown} is not recommended for production use. 3887 3888Examples: 3889 3890@table @code 3891@item -watchdog i6300esb -watchdog-action pause 3892@itemx -watchdog ib700 3893@end table 3894ETEXI 3895 3896DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3897 "-echr chr set terminal escape character instead of ctrl-a\n", 3898 QEMU_ARCH_ALL) 3899STEXI 3900 3901@item -echr @var{numeric_ascii_value} 3902@findex -echr 3903Change the escape character used for switching to the monitor when using 3904monitor and serial sharing. The default is @code{0x01} when using the 3905@code{-nographic} option. @code{0x01} is equal to pressing 3906@code{Control-a}. You can select a different character from the ascii 3907control keys where 1 through 26 map to Control-a through Control-z. For 3908instance you could use the either of the following to change the escape 3909character to Control-t. 3910@table @code 3911@item -echr 0x14 3912@itemx -echr 20 3913@end table 3914ETEXI 3915 3916DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3917 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3918STEXI 3919@item -show-cursor 3920@findex -show-cursor 3921Show cursor. 3922ETEXI 3923 3924DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3925 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3926STEXI 3927@item -tb-size @var{n} 3928@findex -tb-size 3929Set TCG translation block cache size. Deprecated, use @samp{-accel tcg,tb-size=@var{n}} 3930instead. 3931ETEXI 3932 3933DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3934 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3935 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3936 "-incoming unix:socketpath\n" \ 3937 " prepare for incoming migration, listen on\n" \ 3938 " specified protocol and socket address\n" \ 3939 "-incoming fd:fd\n" \ 3940 "-incoming exec:cmdline\n" \ 3941 " accept incoming migration on given file descriptor\n" \ 3942 " or from given external command\n" \ 3943 "-incoming defer\n" \ 3944 " wait for the URI to be specified via migrate_incoming\n", 3945 QEMU_ARCH_ALL) 3946STEXI 3947@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3948@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3949@findex -incoming 3950Prepare for incoming migration, listen on a given tcp port. 3951 3952@item -incoming unix:@var{socketpath} 3953Prepare for incoming migration, listen on a given unix socket. 3954 3955@item -incoming fd:@var{fd} 3956Accept incoming migration from a given filedescriptor. 3957 3958@item -incoming exec:@var{cmdline} 3959Accept incoming migration as an output from specified external command. 3960 3961@item -incoming defer 3962Wait for the URI to be specified via migrate_incoming. The monitor can 3963be used to change settings (such as migration parameters) prior to issuing 3964the migrate_incoming to allow the migration to begin. 3965ETEXI 3966 3967DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3968 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3969STEXI 3970@item -only-migratable 3971@findex -only-migratable 3972Only allow migratable devices. Devices will not be allowed to enter an 3973unmigratable state. 3974ETEXI 3975 3976DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3977 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3978STEXI 3979@item -nodefaults 3980@findex -nodefaults 3981Don't create default devices. Normally, QEMU sets the default devices like serial 3982port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3983CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3984default devices. 3985ETEXI 3986 3987#ifndef _WIN32 3988DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3989 "-chroot dir chroot to dir just before starting the VM\n", 3990 QEMU_ARCH_ALL) 3991#endif 3992STEXI 3993@item -chroot @var{dir} 3994@findex -chroot 3995Immediately before starting guest execution, chroot to the specified 3996directory. Especially useful in combination with -runas. 3997ETEXI 3998 3999#ifndef _WIN32 4000DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4001 "-runas user change to user id user just before starting the VM\n" \ 4002 " user can be numeric uid:gid instead\n", 4003 QEMU_ARCH_ALL) 4004#endif 4005STEXI 4006@item -runas @var{user} 4007@findex -runas 4008Immediately before starting guest execution, drop root privileges, switching 4009to the specified user. 4010ETEXI 4011 4012DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4013 "-prom-env variable=value\n" 4014 " set OpenBIOS nvram variables\n", 4015 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4016STEXI 4017@item -prom-env @var{variable}=@var{value} 4018@findex -prom-env 4019Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4020ETEXI 4021DEF("semihosting", 0, QEMU_OPTION_semihosting, 4022 "-semihosting semihosting mode\n", 4023 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4024 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4025STEXI 4026@item -semihosting 4027@findex -semihosting 4028Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4029ETEXI 4030DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4031 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4032 " semihosting configuration\n", 4033QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4034QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4035STEXI 4036@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4037@findex -semihosting-config 4038Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4039@table @option 4040@item target=@code{native|gdb|auto} 4041Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4042or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4043during debug sessions and @code{native} otherwise. 4044@item chardev=@var{str1} 4045Send the output to a chardev backend output for native or auto output when not in gdb 4046@item arg=@var{str1},arg=@var{str2},... 4047Allows the user to pass input arguments, and can be used multiple times to build 4048up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4049command line is still supported for backward compatibility. If both the 4050@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4051specified, the former is passed to semihosting as it always takes precedence. 4052@end table 4053ETEXI 4054DEF("old-param", 0, QEMU_OPTION_old_param, 4055 "-old-param old param mode\n", QEMU_ARCH_ARM) 4056STEXI 4057@item -old-param 4058@findex -old-param (ARM) 4059Old param mode (ARM only). 4060ETEXI 4061 4062DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4063 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4064 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4065 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4066 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4067 " by the kernel, but typically no longer used by modern\n" \ 4068 " C library implementations.\n" \ 4069 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4070 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4071 " The value 'children' will deny set*uid|gid system calls for\n" \ 4072 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4073 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4074 " blacklisting *fork and execve\n" \ 4075 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4076 QEMU_ARCH_ALL) 4077STEXI 4078@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4079@findex -sandbox 4080Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4081disable it. The default is 'off'. 4082@table @option 4083@item obsolete=@var{string} 4084Enable Obsolete system calls 4085@item elevateprivileges=@var{string} 4086Disable set*uid|gid system calls 4087@item spawn=@var{string} 4088Disable *fork and execve 4089@item resourcecontrol=@var{string} 4090Disable process affinity and schedular priority 4091@end table 4092ETEXI 4093 4094DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4095 "-readconfig <file>\n", QEMU_ARCH_ALL) 4096STEXI 4097@item -readconfig @var{file} 4098@findex -readconfig 4099Read device configuration from @var{file}. This approach is useful when you want to spawn 4100QEMU process with many command line options but you don't want to exceed the command line 4101character limit. 4102ETEXI 4103DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4104 "-writeconfig <file>\n" 4105 " read/write config file\n", QEMU_ARCH_ALL) 4106STEXI 4107@item -writeconfig @var{file} 4108@findex -writeconfig 4109Write device configuration to @var{file}. The @var{file} can be either filename to save 4110command line and device configuration into file or dash @code{-}) character to print the 4111output to stdout. This can be later used as input file for @code{-readconfig} option. 4112ETEXI 4113 4114DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4115 "-no-user-config\n" 4116 " do not load default user-provided config files at startup\n", 4117 QEMU_ARCH_ALL) 4118STEXI 4119@item -no-user-config 4120@findex -no-user-config 4121The @code{-no-user-config} option makes QEMU not load any of the user-provided 4122config files on @var{sysconfdir}. 4123ETEXI 4124 4125DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4126 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4127 " specify tracing options\n", 4128 QEMU_ARCH_ALL) 4129STEXI 4130HXCOMM This line is not accurate, as some sub-options are backend-specific but 4131HXCOMM HX does not support conditional compilation of text. 4132@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4133@findex -trace 4134@include qemu-option-trace.texi 4135ETEXI 4136DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4137 "-plugin [file=]<file>[,arg=<string>]\n" 4138 " load a plugin\n", 4139 QEMU_ARCH_ALL) 4140STEXI 4141@item -plugin file=@var{file}[,arg=@var{string}] 4142@findex -plugin 4143 4144Load a plugin. 4145 4146@table @option 4147@item file=@var{file} 4148Load the given plugin from a shared library file. 4149@item arg=@var{string} 4150Argument string passed to the plugin. (Can be given multiple times.) 4151@end table 4152ETEXI 4153 4154HXCOMM Internal use 4155DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4156DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4157 4158#ifdef __linux__ 4159DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4160 "-enable-fips enable FIPS 140-2 compliance\n", 4161 QEMU_ARCH_ALL) 4162#endif 4163STEXI 4164@item -enable-fips 4165@findex -enable-fips 4166Enable FIPS 140-2 compliance mode. 4167ETEXI 4168 4169HXCOMM Deprecated by -accel tcg 4170DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4171 4172DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4173 "-msg timestamp[=on|off]\n" 4174 " change the format of messages\n" 4175 " on|off controls leading timestamps (default:on)\n", 4176 QEMU_ARCH_ALL) 4177STEXI 4178@item -msg timestamp[=on|off] 4179@findex -msg 4180prepend a timestamp to each log message.(default:on) 4181ETEXI 4182 4183DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4184 "-dump-vmstate <file>\n" 4185 " Output vmstate information in JSON format to file.\n" 4186 " Use the scripts/vmstate-static-checker.py file to\n" 4187 " check for possible regressions in migration code\n" 4188 " by comparing two such vmstate dumps.\n", 4189 QEMU_ARCH_ALL) 4190STEXI 4191@item -dump-vmstate @var{file} 4192@findex -dump-vmstate 4193Dump json-encoded vmstate information for current machine type to file 4194in @var{file} 4195ETEXI 4196 4197DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4198 "-enable-sync-profile\n" 4199 " enable synchronization profiling\n", 4200 QEMU_ARCH_ALL) 4201STEXI 4202@item -enable-sync-profile 4203@findex -enable-sync-profile 4204Enable synchronization profiling. 4205ETEXI 4206 4207STEXI 4208@end table 4209ETEXI 4210DEFHEADING() 4211 4212DEFHEADING(Generic object creation:) 4213STEXI 4214@table @option 4215ETEXI 4216 4217DEF("object", HAS_ARG, QEMU_OPTION_object, 4218 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4219 " create a new object of type TYPENAME setting properties\n" 4220 " in the order they are specified. Note that the 'id'\n" 4221 " property must be set. These objects are placed in the\n" 4222 " '/objects' path.\n", 4223 QEMU_ARCH_ALL) 4224STEXI 4225@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4226@findex -object 4227Create a new object of type @var{typename} setting properties 4228in the order they are specified. Note that the 'id' 4229property must be set. These objects are placed in the 4230'/objects' path. 4231 4232@table @option 4233 4234@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} 4235 4236Creates a memory file backend object, which can be used to back 4237the guest RAM with huge pages. 4238 4239The @option{id} parameter is a unique ID that will be used to reference this 4240memory region when configuring the @option{-numa} argument. 4241 4242The @option{size} option provides the size of the memory region, and accepts 4243common suffixes, eg @option{500M}. 4244 4245The @option{mem-path} provides the path to either a shared memory or huge page 4246filesystem mount. 4247 4248The @option{share} boolean option determines whether the memory 4249region is marked as private to QEMU, or shared. The latter allows 4250a co-operating external process to access the QEMU memory region. 4251 4252The @option{share} is also required for pvrdma devices due to 4253limitations in the RDMA API provided by Linux. 4254 4255Setting share=on might affect the ability to configure NUMA 4256bindings for the memory backend under some circumstances, see 4257Documentation/vm/numa_memory_policy.txt on the Linux kernel 4258source tree for additional details. 4259 4260Setting the @option{discard-data} boolean option to @var{on} 4261indicates that file contents can be destroyed when QEMU exits, 4262to avoid unnecessarily flushing data to the backing file. Note 4263that @option{discard-data} is only an optimization, and QEMU 4264might not discard file contents if it aborts unexpectedly or is 4265terminated using SIGKILL. 4266 4267The @option{merge} boolean option enables memory merge, also known as 4268MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4269memory deduplication. 4270 4271Setting the @option{dump} boolean option to @var{off} excludes the memory from 4272core dumps. This feature is also known as MADV_DONTDUMP. 4273 4274The @option{prealloc} boolean option enables memory preallocation. 4275 4276The @option{host-nodes} option binds the memory range to a list of NUMA host 4277nodes. 4278 4279The @option{policy} option sets the NUMA policy to one of the following values: 4280 4281@table @option 4282@item @var{default} 4283default host policy 4284 4285@item @var{preferred} 4286prefer the given host node list for allocation 4287 4288@item @var{bind} 4289restrict memory allocation to the given host node list 4290 4291@item @var{interleave} 4292interleave memory allocations across the given host node list 4293@end table 4294 4295The @option{align} option specifies the base address alignment when 4296QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4297@option{2M}. Some backend store specified by @option{mem-path} 4298requires an alignment different than the default one used by QEMU, eg 4299the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4300such cases, users can specify the required alignment via this option. 4301 4302The @option{pmem} option specifies whether the backing file specified 4303by @option{mem-path} is in host persistent memory that can be accessed 4304using the SNIA NVM programming model (e.g. Intel NVDIMM). 4305If @option{pmem} is set to 'on', QEMU will take necessary operations to 4306guarantee the persistence of its own writes to @option{mem-path} 4307(e.g. in vNVDIMM label emulation and live migration). 4308Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4309file metadata is in sync for @option{mem-path} in case of host crash 4310or a power failure. MAP_SYNC requires support from both the host kernel 4311(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4312with DAX option. 4313 4314@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} 4315 4316Creates a memory backend object, which can be used to back the guest RAM. 4317Memory backend objects offer more control than the @option{-m} option that is 4318traditionally used to define guest RAM. Please refer to 4319@option{memory-backend-file} for a description of the options. 4320 4321@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} 4322 4323Creates an anonymous memory file backend object, which allows QEMU to 4324share the memory with an external process (e.g. when using 4325vhost-user). The memory is allocated with memfd and optional 4326sealing. (Linux only) 4327 4328The @option{seal} option creates a sealed-file, that will block 4329further resizing the memory ('on' by default). 4330 4331The @option{hugetlb} option specify the file to be created resides in 4332the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4333the @option{hugetlb} option, the @option{hugetlbsize} option specify 4334the hugetlb page size on systems that support multiple hugetlb page 4335sizes (it must be a power of 2 value supported by the system). 4336 4337In some versions of Linux, the @option{hugetlb} option is incompatible 4338with the @option{seal} option (requires at least Linux 4.16). 4339 4340Please refer to @option{memory-backend-file} for a description of the 4341other options. 4342 4343The @option{share} boolean option is @var{on} by default with memfd. 4344 4345@item -object rng-builtin,id=@var{id} 4346 4347Creates a random number generator backend which obtains entropy from 4348QEMU builtin functions. The @option{id} parameter is a unique ID that 4349will be used to reference this entropy backend from the @option{virtio-rng} 4350device. By default, the @option{virtio-rng} device uses this RNG backend. 4351 4352@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4353 4354Creates a random number generator backend which obtains entropy from 4355a device on the host. The @option{id} parameter is a unique ID that 4356will be used to reference this entropy backend from the @option{virtio-rng} 4357device. The @option{filename} parameter specifies which file to obtain 4358entropy from and if omitted defaults to @option{/dev/urandom}. 4359 4360@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4361 4362Creates a random number generator backend which obtains entropy from 4363an external daemon running on the host. The @option{id} parameter is 4364a unique ID that will be used to reference this entropy backend from 4365the @option{virtio-rng} device. The @option{chardev} parameter is 4366the unique ID of a character device backend that provides the connection 4367to the RNG daemon. 4368 4369@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4370 4371Creates a TLS anonymous credentials object, which can be used to provide 4372TLS support on network backends. The @option{id} parameter is a unique 4373ID which network backends will use to access the credentials. The 4374@option{endpoint} is either @option{server} or @option{client} depending 4375on whether the QEMU network backend that uses the credentials will be 4376acting as a client or as a server. If @option{verify-peer} is enabled 4377(the default) then once the handshake is completed, the peer credentials 4378will be verified, though this is a no-op for anonymous credentials. 4379 4380The @var{dir} parameter tells QEMU where to find the credential 4381files. For server endpoints, this directory may contain a file 4382@var{dh-params.pem} providing diffie-hellman parameters to use 4383for the TLS server. If the file is missing, QEMU will generate 4384a set of DH parameters at startup. This is a computationally 4385expensive operation that consumes random pool entropy, so it is 4386recommended that a persistent set of parameters be generated 4387upfront and saved. 4388 4389@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4390 4391Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4392TLS support on network backends. The @option{id} parameter is a unique 4393ID which network backends will use to access the credentials. The 4394@option{endpoint} is either @option{server} or @option{client} depending 4395on whether the QEMU network backend that uses the credentials will be 4396acting as a client or as a server. For clients only, @option{username} 4397is the username which will be sent to the server. If omitted 4398it defaults to ``qemu''. 4399 4400The @var{dir} parameter tells QEMU where to find the keys file. 4401It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4402pairs. This file can most easily be created using the GnuTLS 4403@code{psktool} program. 4404 4405For server endpoints, @var{dir} may also contain a file 4406@var{dh-params.pem} providing diffie-hellman parameters to use 4407for the TLS server. If the file is missing, QEMU will generate 4408a set of DH parameters at startup. This is a computationally 4409expensive operation that consumes random pool entropy, so it is 4410recommended that a persistent set of parameters be generated 4411up front and saved. 4412 4413@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} 4414 4415Creates a TLS anonymous credentials object, which can be used to provide 4416TLS support on network backends. The @option{id} parameter is a unique 4417ID which network backends will use to access the credentials. The 4418@option{endpoint} is either @option{server} or @option{client} depending 4419on whether the QEMU network backend that uses the credentials will be 4420acting as a client or as a server. If @option{verify-peer} is enabled 4421(the default) then once the handshake is completed, the peer credentials 4422will be verified. With x509 certificates, this implies that the clients 4423must be provided with valid client certificates too. 4424 4425The @var{dir} parameter tells QEMU where to find the credential 4426files. For server endpoints, this directory may contain a file 4427@var{dh-params.pem} providing diffie-hellman parameters to use 4428for the TLS server. If the file is missing, QEMU will generate 4429a set of DH parameters at startup. This is a computationally 4430expensive operation that consumes random pool entropy, so it is 4431recommended that a persistent set of parameters be generated 4432upfront and saved. 4433 4434For x509 certificate credentials the directory will contain further files 4435providing the x509 certificates. The certificates must be stored 4436in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4437@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4438@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4439 4440For the @var{server-key.pem} and @var{client-key.pem} files which 4441contain sensitive private keys, it is possible to use an encrypted 4442version by providing the @var{passwordid} parameter. This provides 4443the ID of a previously created @code{secret} object containing the 4444password for decryption. 4445 4446The @var{priority} parameter allows to override the global default 4447priority used by gnutls. This can be useful if the system administrator 4448needs to use a weaker set of crypto priorities for QEMU without 4449potentially forcing the weakness onto all applications. Or conversely 4450if one wants wants a stronger default for QEMU than for all other 4451applications, they can do this through this parameter. Its format is 4452a gnutls priority string as described at 4453@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4454 4455@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4456 4457Interval @var{t} can't be 0, this filter batches the packet delivery: all 4458packets arriving in a given interval on netdev @var{netdevid} are delayed 4459until the end of the interval. Interval is in microseconds. 4460@option{status} is optional that indicate whether the netfilter is 4461on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4462 4463queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4464 4465@option{all}: the filter is attached both to the receive and the transmit 4466 queue of the netdev (default). 4467 4468@option{rx}: the filter is attached to the receive queue of the netdev, 4469 where it will receive packets sent to the netdev. 4470 4471@option{tx}: the filter is attached to the transmit queue of the netdev, 4472 where it will receive packets sent by the netdev. 4473 4474@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4475 4476filter-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. 4477 4478@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4479 4480filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4481@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4482filter-redirector will redirect packet with vnet_hdr_len. 4483Create a filter-redirector we need to differ outdev id from indev id, id can not 4484be the same. we can just use indev or outdev, but at least one of indev or outdev 4485need to be specified. 4486 4487@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4488 4489Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4490secondary from primary to keep secondary tcp connection,and rewrite 4491tcp packet to primary from secondary make tcp packet can be handled by 4492client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4493 4494usage: 4495colo secondary: 4496-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4497-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4498-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4499 4500@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4501 4502Dump the network traffic on netdev @var{dev} to the file specified by 4503@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4504The file format is libpcap, so it can be analyzed with tools such as tcpdump 4505or Wireshark. 4506 4507@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid},iothread=@var{id}[,vnet_hdr_support][,notify_dev=@var{id}] 4508 4509Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4510secondary packet. If the packets are same, we will output primary 4511packet to outdev@var{chardevid}, else we will notify colo-frame 4512do checkpoint and send primary packet to outdev@var{chardevid}. 4513In order to improve efficiency, we need to put the task of comparison 4514in another thread. If it has the vnet_hdr_support flag, colo compare 4515will send/recv packet with vnet_hdr_len. 4516If you want to use Xen COLO, will need the notify_dev to notify Xen 4517colo-frame to do checkpoint. 4518 4519we must use it with the help of filter-mirror and filter-redirector. 4520 4521@example 4522 4523KVM COLO 4524 4525primary: 4526-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4527-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4528-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4529-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4530-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4531-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4532-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4533-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4534-object iothread,id=iothread1 4535-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4536-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4537-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4538-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4539 4540secondary: 4541-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4542-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4543-chardev socket,id=red0,host=3.3.3.3,port=9003 4544-chardev socket,id=red1,host=3.3.3.3,port=9004 4545-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4546-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4547 4548 4549Xen COLO 4550 4551primary: 4552-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4553-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4554-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4555-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4556-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4557-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4558-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4559-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4560-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4561-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4562-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4563-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4564-object iothread,id=iothread1 4565-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4566 4567secondary: 4568-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4569-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4570-chardev socket,id=red0,host=3.3.3.3,port=9003 4571-chardev socket,id=red1,host=3.3.3.3,port=9004 4572-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4573-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4574 4575@end example 4576 4577If you want to know the detail of above command line, you can read 4578the colo-compare git log. 4579 4580@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4581 4582Creates a cryptodev backend which executes crypto opreation from 4583the QEMU cipher APIS. The @var{id} parameter is 4584a unique ID that will be used to reference this cryptodev backend from 4585the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4586which specify the queue number of cryptodev backend, the default of 4587@var{queues} is 1. 4588 4589@example 4590 4591 # @value{qemu_system} \ 4592 [...] \ 4593 -object cryptodev-backend-builtin,id=cryptodev0 \ 4594 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4595 [...] 4596@end example 4597 4598@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4599 4600Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4601The @var{id} parameter is a unique ID that will be used to reference this 4602cryptodev backend from the @option{virtio-crypto} device. 4603The chardev should be a unix domain socket backed one. The vhost-user uses 4604a specifically defined protocol to pass vhost ioctl replacement messages 4605to an application on the other end of the socket. 4606The @var{queues} parameter is optional, which specify the queue number 4607of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4608 4609@example 4610 4611 # @value{qemu_system} \ 4612 [...] \ 4613 -chardev socket,id=chardev0,path=/path/to/socket \ 4614 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4615 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4616 [...] 4617@end example 4618 4619@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4620@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4621 4622Defines a secret to store a password, encryption key, or some other sensitive 4623data. The sensitive data can either be passed directly via the @var{data} 4624parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4625parameter is insecure unless the sensitive data is encrypted. 4626 4627The sensitive data can be provided in raw format (the default), or base64. 4628When encoded as JSON, the raw format only supports valid UTF-8 characters, 4629so base64 is recommended for sending binary data. QEMU will convert from 4630which ever format is provided to the format it needs internally. eg, an 4631RBD password can be provided in raw format, even though it will be base64 4632encoded when passed onto the RBD sever. 4633 4634For added protection, it is possible to encrypt the data associated with 4635a secret using the AES-256-CBC cipher. Use of encryption is indicated 4636by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4637parameter provides the ID of a previously defined secret that contains 4638the AES-256 decryption key. This key should be 32-bytes long and be 4639base64 encoded. The @var{iv} parameter provides the random initialization 4640vector used for encryption of this particular secret and should be a 4641base64 encrypted string of the 16-byte IV. 4642 4643The simplest (insecure) usage is to provide the secret inline 4644 4645@example 4646 4647 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4648 4649@end example 4650 4651The simplest secure usage is to provide the secret via a file 4652 4653 # printf "letmein" > mypasswd.txt 4654 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4655 4656For greater security, AES-256-CBC should be used. To illustrate usage, 4657consider the openssl command line tool which can encrypt the data. Note 4658that when encrypting, the plaintext must be padded to the cipher block 4659size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4660 4661First a master key needs to be created in base64 encoding: 4662 4663@example 4664 # openssl rand -base64 32 > key.b64 4665 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4666@end example 4667 4668Each secret to be encrypted needs to have a random initialization vector 4669generated. These do not need to be kept secret 4670 4671@example 4672 # openssl rand -base64 16 > iv.b64 4673 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4674@end example 4675 4676The secret to be defined can now be encrypted, in this case we're 4677telling openssl to base64 encode the result, but it could be left 4678as raw bytes if desired. 4679 4680@example 4681 # SECRET=$(printf "letmein" | 4682 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4683@end example 4684 4685When launching QEMU, create a master secret pointing to @code{key.b64} 4686and specify that to be used to decrypt the user password. Pass the 4687contents of @code{iv.b64} to the second secret 4688 4689@example 4690 # @value{qemu_system} \ 4691 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4692 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4693 data=$SECRET,iv=$(<iv.b64) 4694@end example 4695 4696@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}] 4697 4698Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4699to provide the guest memory encryption support on AMD processors. 4700 4701When memory encryption is enabled, one of the physical address bit (aka the 4702C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4703is used to provide the C-bit position. The C-bit position is Host family dependent 4704hence user must provide this value. On EPYC, the value should be 47. 4705 4706When memory encryption is enabled, we loose certain bits in physical address space. 4707The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4708physical address space. Similar to C-bit, the value is Host family dependent. 4709On EPYC, the value should be 5. 4710 4711The @option{sev-device} provides the device file to use for communicating with 4712the SEV firmware running inside AMD Secure Processor. The default device is 4713'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4714created by CCP driver. 4715 4716The @option{policy} provides the guest policy to be enforced by the SEV firmware 4717and restrict what configuration and operational commands can be performed on this 4718guest by the hypervisor. The policy should be provided by the guest owner and is 4719bound to the guest and cannot be changed throughout the lifetime of the guest. 4720The default is 0. 4721 4722If guest @option{policy} allows sharing the key with another SEV guest then 4723@option{handle} can be use to provide handle of the guest from which to share 4724the key. 4725 4726The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4727Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4728are used for establishing a cryptographic session with the guest owner to 4729negotiate keys used for attestation. The file must be encoded in base64. 4730 4731e.g to launch a SEV guest 4732@example 4733 # @value{qemu_system_x86} \ 4734 ...... 4735 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4736 -machine ...,memory-encryption=sev0 4737 ..... 4738 4739@end example 4740 4741 4742@item -object authz-simple,id=@var{id},identity=@var{string} 4743 4744Create an authorization object that will control access to network services. 4745 4746The @option{identity} parameter is identifies the user and its format 4747depends on the network service that authorization object is associated 4748with. For authorizing based on TLS x509 certificates, the identity must 4749be the x509 distinguished name. Note that care must be taken to escape 4750any commas in the distinguished name. 4751 4752An example authorization object to validate a x509 distinguished name 4753would look like: 4754@example 4755 # @value{qemu_system} \ 4756 ... 4757 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4758 ... 4759@end example 4760 4761Note the use of quotes due to the x509 distinguished name containing 4762whitespace, and escaping of ','. 4763 4764@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4765 4766Create an authorization object that will control access to network services. 4767 4768The @option{filename} parameter is the fully qualified path to a file 4769containing the access control list rules in JSON format. 4770 4771An example set of rules that match against SASL usernames might look 4772like: 4773 4774@example 4775 @{ 4776 "rules": [ 4777 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4778 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4779 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4780 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4781 ], 4782 "policy": "deny" 4783 @} 4784@end example 4785 4786When checking access the object will iterate over all the rules and 4787the first rule to match will have its @option{policy} value returned 4788as the result. If no rules match, then the default @option{policy} 4789value is returned. 4790 4791The rules can either be an exact string match, or they can use the 4792simple UNIX glob pattern matching to allow wildcards to be used. 4793 4794If @option{refresh} is set to true the file will be monitored 4795and automatically reloaded whenever its content changes. 4796 4797As with the @code{authz-simple} object, the format of the identity 4798strings being matched depends on the network service, but is usually 4799a TLS x509 distinguished name, or a SASL username. 4800 4801An example authorization object to validate a SASL username 4802would look like: 4803@example 4804 # @value{qemu_system} \ 4805 ... 4806 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4807 ... 4808@end example 4809 4810@item -object authz-pam,id=@var{id},service=@var{string} 4811 4812Create an authorization object that will control access to network services. 4813 4814The @option{service} parameter provides the name of a PAM service to use 4815for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4816exist to provide the configuration for the @code{account} subsystem. 4817 4818An example authorization object to validate a TLS x509 distinguished 4819name would look like: 4820 4821@example 4822 # @value{qemu_system} \ 4823 ... 4824 -object authz-pam,id=auth0,service=qemu-vnc 4825 ... 4826@end example 4827 4828There would then be a corresponding config file for PAM at 4829@code{/etc/pam.d/qemu-vnc} that contains: 4830 4831@example 4832account requisite pam_listfile.so item=user sense=allow \ 4833 file=/etc/qemu/vnc.allow 4834@end example 4835 4836Finally the @code{/etc/qemu/vnc.allow} file would contain 4837the list of x509 distingished names that are permitted 4838access 4839 4840@example 4841CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4842@end example 4843 4844@item -object iothread,id=@var{id},poll-max-ns=@var{poll-max-ns},poll-grow=@var{poll-grow},poll-shrink=@var{poll-shrink} 4845 4846Creates a dedicated event loop thread that devices can be assigned to. This is 4847known as an IOThread. By default device emulation happens in vCPU threads or 4848the main event loop thread. This can become a scalability bottleneck. 4849IOThreads allow device emulation and I/O to run on other host CPUs. 4850 4851The @option{id} parameter is a unique ID that will be used to reference this 4852IOThread from @option{-device ...,iothread=@var{id}}. Multiple devices can be 4853assigned to an IOThread. Note that not all devices support an 4854@option{iothread} parameter. 4855 4856The @code{query-iothreads} QMP command lists IOThreads and reports their thread 4857IDs so that the user can configure host CPU pinning/affinity. 4858 4859IOThreads use an adaptive polling algorithm to reduce event loop latency. 4860Instead of entering a blocking system call to monitor file descriptors and then 4861pay the cost of being woken up when an event occurs, the polling algorithm 4862spins waiting for events for a short time. The algorithm's default parameters 4863are suitable for many cases but can be adjusted based on knowledge of the 4864workload and/or host device latency. 4865 4866The @option{poll-max-ns} parameter is the maximum number of nanoseconds to busy 4867wait for events. Polling can be disabled by setting this value to 0. 4868 4869The @option{poll-grow} parameter is the multiplier used to increase the polling 4870time when the algorithm detects it is missing events due to not polling long 4871enough. 4872 4873The @option{poll-shrink} parameter is the divisor used to decrease the polling 4874time when the algorithm detects it is spending too long polling without 4875encountering events. 4876 4877The polling parameters can be modified at run-time using the @code{qom-set} command (where @code{iothread1} is the IOThread's @code{id}): 4878 4879@example 4880(qemu) qom-set /objects/iothread1 poll-max-ns 100000 4881@end example 4882 4883@end table 4884 4885ETEXI 4886 4887 4888HXCOMM This is the last statement. Insert new options before this line! 4889STEXI 4890@end table 4891ETEXI 4892
