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 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 38 " mem-merge=on|off controls memory merge support (default: on)\n" 39 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 40 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 41 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 42 " nvdimm=on|off controls NVDIMM support (default=off)\n" 43 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 44 " memory-encryption=@var{} memory encryption object to use (default=none)\n", 45 QEMU_ARCH_ALL) 46STEXI 47@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 48@findex -machine 49Select the emulated machine by @var{name}. Use @code{-machine help} to list 50available machines. 51 52For architectures which aim to support live migration compatibility 53across releases, each release will introduce a new versioned machine 54type. For example, the 2.8.0 release introduced machine types 55``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. 56 57To allow live migration of guests from QEMU version 2.8.0, to QEMU 58version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' 59and ``pc-q35-2.8'' machines too. To allow users live migrating VMs 60to skip multiple intermediate releases when upgrading, new releases 61of QEMU will support machine types from many previous versions. 62 63Supported machine properties are: 64@table @option 65@item accel=@var{accels1}[:@var{accels2}[:...]] 66This is used to enable an accelerator. Depending on the target architecture, 67kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 68more than one accelerator specified, the next one is used if the previous one 69fails to initialize. 70@item kernel_irqchip=on|off 71Controls in-kernel irqchip support for the chosen accelerator when available. 72@item vmport=on|off|auto 73Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 74value based on accel. For accel=xen the default is off otherwise the default 75is on. 76@item dump-guest-core=on|off 77Include guest memory in a core dump. The default is on. 78@item mem-merge=on|off 79Enables or disables memory merge support. This feature, when supported by 80the host, de-duplicates identical memory pages among VMs instances 81(enabled by default). 82@item aes-key-wrap=on|off 83Enables or disables AES key wrapping support on s390-ccw hosts. This feature 84controls whether AES wrapping keys will be created to allow 85execution of AES cryptographic functions. The default is on. 86@item dea-key-wrap=on|off 87Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 88controls whether DEA wrapping keys will be created to allow 89execution of DEA cryptographic functions. The default is on. 90@item nvdimm=on|off 91Enables or disables NVDIMM support. The default is off. 92@item enforce-config-section=on|off 93If @option{enforce-config-section} is set to @var{on}, force migration 94code to send configuration section even if the machine-type sets the 95@option{migration.send-configuration} property to @var{off}. 96NOTE: this parameter is deprecated. Please use @option{-global} 97@option{migration.send-configuration}=@var{on|off} instead. 98@item memory-encryption=@var{} 99Memory encryption object to use. The default is none. 100@end table 101ETEXI 102 103HXCOMM Deprecated by -machine 104DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 105 106DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 107 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 108STEXI 109@item -cpu @var{model} 110@findex -cpu 111Select CPU model (@code{-cpu help} for list and additional feature selection) 112ETEXI 113 114DEF("accel", HAS_ARG, QEMU_OPTION_accel, 115 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 116 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 117 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 118 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 119 " tb-size=n (TCG translation block cache size)\n" 120 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 121STEXI 122@item -accel @var{name}[,prop=@var{value}[,...]] 123@findex -accel 124This is used to enable an accelerator. Depending on the target architecture, 125kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 126more than one accelerator specified, the next one is used if the previous one 127fails to initialize. 128@table @option 129@item igd-passthru=on|off 130When Xen is in use, this option controls whether Intel integrated graphics 131devices can be passed through to the guest (default=off) 132@item kvm-shadow-mem=size 133Defines the size of the KVM shadow MMU. 134@item tb-size=@var{n} 135Controls the size (in MiB) of the TCG translation block cache. 136@item thread=single|multi 137Controls number of TCG threads. When the TCG is multi-threaded there will be one 138thread per vCPU therefor taking advantage of additional host cores. The default 139is to enable multi-threading where both the back-end and front-ends support it and 140no incompatible TCG features have been enabled (e.g. icount/replay). 141@end table 142ETEXI 143 144DEF("smp", HAS_ARG, QEMU_OPTION_smp, 145 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n" 146 " set the number of CPUs to 'n' [default=1]\n" 147 " maxcpus= maximum number of total cpus, including\n" 148 " offline CPUs for hotplug, etc\n" 149 " cores= number of CPU cores on one socket (for PC, it's on one die)\n" 150 " threads= number of threads on one CPU core\n" 151 " dies= number of CPU dies on one socket (for PC only)\n" 152 " sockets= number of discrete sockets in the system\n", 153 QEMU_ARCH_ALL) 154STEXI 155@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,dies=dies][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 156@findex -smp 157Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 158CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 159to 4. 160For the PC target, the number of @var{cores} per die, the number of @var{threads} 161per cores, the number of @var{dies} per packages and the total number of 162@var{sockets} can be specified. Missing values will be computed. 163If any on the three values is given, the total number of CPUs @var{n} can be omitted. 164@var{maxcpus} specifies the maximum number of hotpluggable CPUs. 165ETEXI 166 167DEF("numa", HAS_ARG, QEMU_OPTION_numa, 168 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 169 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 170 "-numa dist,src=source,dst=destination,val=distance\n" 171 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n", 172 QEMU_ARCH_ALL) 173STEXI 174@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 175@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 176@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 177@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 178@findex -numa 179Define a NUMA node and assign RAM and VCPUs to it. 180Set the NUMA distance from a source node to a destination node. 181 182Legacy VCPU assignment uses @samp{cpus} option where 183@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 184@samp{cpus} option represent a contiguous range of CPU indexes 185(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 186set of VCPUs can be represented by providing multiple @samp{cpus} 187options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 188split between them. 189 190For example, the following option assigns VCPUs 0, 1, 2 and 5 to 191a NUMA node: 192@example 193-numa node,cpus=0-2,cpus=5 194@end example 195 196@samp{cpu} option is a new alternative to @samp{cpus} option 197which uses @samp{socket-id|core-id|thread-id} properties to assign 198CPU objects to a @var{node} using topology layout properties of CPU. 199The set of properties is machine specific, and depends on used 200machine type/@samp{smp} options. It could be queried with 201@samp{hotpluggable-cpus} monitor command. 202@samp{node-id} property specifies @var{node} to which CPU object 203will be assigned, it's required for @var{node} to be declared 204with @samp{node} option before it's used with @samp{cpu} option. 205 206For example: 207@example 208-M pc \ 209-smp 1,sockets=2,maxcpus=2 \ 210-numa node,nodeid=0 -numa node,nodeid=1 \ 211-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 212@end example 213 214@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 215assigns RAM from a given memory backend device to a node. If 216@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 217split equally between them. 218 219@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 220if one node uses @samp{memdev}, all of them have to use it. 221 222@var{source} and @var{destination} are NUMA node IDs. 223@var{distance} is the NUMA distance from @var{source} to @var{destination}. 224The distance from a node to itself is always 10. If any pair of nodes is 225given a distance, then all pairs must be given distances. Although, when 226distances are only given in one direction for each pair of nodes, then 227the distances in the opposite directions are assumed to be the same. If, 228however, an asymmetrical pair of distances is given for even one node 229pair, then all node pairs must be provided distance values for both 230directions, even when they are symmetrical. When a node is unreachable 231from another node, set the pair's distance to 255. 232 233Note that the -@option{numa} option doesn't allocate any of the 234specified resources, it just assigns existing resources to NUMA 235nodes. This means that one still has to use the @option{-m}, 236@option{-smp} options to allocate RAM and VCPUs respectively. 237 238ETEXI 239 240DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 241 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 242 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 243STEXI 244@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 245@findex -add-fd 246 247Add a file descriptor to an fd set. Valid options are: 248 249@table @option 250@item fd=@var{fd} 251This option defines the file descriptor of which a duplicate is added to fd set. 252The file descriptor cannot be stdin, stdout, or stderr. 253@item set=@var{set} 254This option defines the ID of the fd set to add the file descriptor to. 255@item opaque=@var{opaque} 256This option defines a free-form string that can be used to describe @var{fd}. 257@end table 258 259You can open an image using pre-opened file descriptors from an fd set: 260@example 261@value{qemu_system} \ 262 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 263 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 264 -drive file=/dev/fdset/2,index=0,media=disk 265@end example 266ETEXI 267 268DEF("set", HAS_ARG, QEMU_OPTION_set, 269 "-set group.id.arg=value\n" 270 " set <arg> parameter for item <id> of type <group>\n" 271 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 272STEXI 273@item -set @var{group}.@var{id}.@var{arg}=@var{value} 274@findex -set 275Set parameter @var{arg} for item @var{id} of type @var{group} 276ETEXI 277 278DEF("global", HAS_ARG, QEMU_OPTION_global, 279 "-global driver.property=value\n" 280 "-global driver=driver,property=property,value=value\n" 281 " set a global default for a driver property\n", 282 QEMU_ARCH_ALL) 283STEXI 284@item -global @var{driver}.@var{prop}=@var{value} 285@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 286@findex -global 287Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 288 289@example 290@value{qemu_system_x86} -global ide-hd.physical_block_size=4096 disk-image.img 291@end example 292 293In particular, you can use this to set driver properties for devices which are 294created automatically by the machine model. To create a device which is not 295created automatically and set properties on it, use -@option{device}. 296 297-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 298driver=@var{driver},property=@var{prop},value=@var{value}. The 299longhand syntax works even when @var{driver} contains a dot. 300ETEXI 301 302DEF("boot", HAS_ARG, QEMU_OPTION_boot, 303 "-boot [order=drives][,once=drives][,menu=on|off]\n" 304 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 305 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 306 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 307 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 308 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 309 QEMU_ARCH_ALL) 310STEXI 311@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] 312@findex -boot 313Specify boot order @var{drives} as a string of drive letters. Valid 314drive letters depend on the target architecture. The x86 PC uses: a, b 315(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 316from network adapter 1-4), hard disk boot is the default. To apply a 317particular boot order only on the first startup, specify it via 318@option{once}. Note that the @option{order} or @option{once} parameter 319should not be used together with the @option{bootindex} property of 320devices, since the firmware implementations normally do not support both 321at the same time. 322 323Interactive boot menus/prompts can be enabled via @option{menu=on} as far 324as firmware/BIOS supports them. The default is non-interactive boot. 325 326A splash picture could be passed to bios, enabling user to show it as logo, 327when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 328supports them. Currently Seabios for X86 system support it. 329limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 330format(true color). The resolution should be supported by the SVGA mode, so 331the recommended is 320x240, 640x480, 800x640. 332 333A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 334when boot failed, then reboot. If @option{reboot-timeout} is not set, 335guest will not reboot by default. Currently Seabios for X86 336system support it. 337 338Do strict boot via @option{strict=on} as far as firmware/BIOS 339supports it. This only effects when boot priority is changed by 340bootindex options. The default is non-strict boot. 341 342@example 343# try to boot from network first, then from hard disk 344@value{qemu_system_x86} -boot order=nc 345# boot from CD-ROM first, switch back to default order after reboot 346@value{qemu_system_x86} -boot once=d 347# boot with a splash picture for 5 seconds. 348@value{qemu_system_x86} -boot menu=on,splash=/root/boot.bmp,splash-time=5000 349@end example 350 351Note: The legacy format '-boot @var{drives}' is still supported but its 352use is discouraged as it may be removed from future versions. 353ETEXI 354 355DEF("m", HAS_ARG, QEMU_OPTION_m, 356 "-m [size=]megs[,slots=n,maxmem=size]\n" 357 " configure guest RAM\n" 358 " size: initial amount of guest memory\n" 359 " slots: number of hotplug slots (default: none)\n" 360 " maxmem: maximum amount of guest memory (default: none)\n" 361 "NOTE: Some architectures might enforce a specific granularity\n", 362 QEMU_ARCH_ALL) 363STEXI 364@item -m [size=]@var{megs}[,slots=n,maxmem=size] 365@findex -m 366Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 367Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 368megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 369could be used to set amount of hotpluggable memory slots and maximum amount of 370memory. Note that @var{maxmem} must be aligned to the page size. 371 372For example, the following command-line sets the guest startup RAM size to 3731GB, creates 3 slots to hotplug additional memory and sets the maximum 374memory the guest can reach to 4GB: 375 376@example 377@value{qemu_system} -m 1G,slots=3,maxmem=4G 378@end example 379 380If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 381be enabled and the guest startup RAM will never increase. 382ETEXI 383 384DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 385 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 386STEXI 387@item -mem-path @var{path} 388@findex -mem-path 389Allocate guest RAM from a temporarily created file in @var{path}. 390ETEXI 391 392DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 393 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 394 QEMU_ARCH_ALL) 395STEXI 396@item -mem-prealloc 397@findex -mem-prealloc 398Preallocate memory when using -mem-path. 399ETEXI 400 401DEF("k", HAS_ARG, QEMU_OPTION_k, 402 "-k language use keyboard layout (for example 'fr' for French)\n", 403 QEMU_ARCH_ALL) 404STEXI 405@item -k @var{language} 406@findex -k 407Use keyboard layout @var{language} (for example @code{fr} for 408French). This option is only needed where it is not easy to get raw PC 409keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 410display). You don't normally need to use it on PC/Linux or PC/Windows 411hosts. 412 413The available layouts are: 414@example 415ar de-ch es fo fr-ca hu ja mk no pt-br sv 416da en-gb et fr fr-ch is lt nl pl ru th 417de en-us fi fr-be hr it lv nl-be pt sl tr 418@end example 419 420The default is @code{en-us}. 421ETEXI 422 423 424HXCOMM Deprecated by -audiodev 425DEF("audio-help", 0, QEMU_OPTION_audio_help, 426 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 427 QEMU_ARCH_ALL) 428STEXI 429@item -audio-help 430@findex -audio-help 431Will show the -audiodev equivalent of the currently specified 432(deprecated) environment variables. 433ETEXI 434 435DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 436 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 437 " specifies the audio backend to use\n" 438 " id= identifier of the backend\n" 439 " timer-period= timer period in microseconds\n" 440 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 441 " in|out.fixed-settings= use fixed settings for host audio\n" 442 " in|out.frequency= frequency to use with fixed settings\n" 443 " in|out.channels= number of channels to use with fixed settings\n" 444 " in|out.format= sample format to use with fixed settings\n" 445 " valid values: s8, s16, s32, u8, u16, u32\n" 446 " in|out.voices= number of voices to use\n" 447 " in|out.buffer-length= length of buffer in microseconds\n" 448 "-audiodev none,id=id,[,prop[=value][,...]]\n" 449 " dummy driver that discards all output\n" 450#ifdef CONFIG_AUDIO_ALSA 451 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 452 " in|out.dev= name of the audio device to use\n" 453 " in|out.period-length= length of period in microseconds\n" 454 " in|out.try-poll= attempt to use poll mode\n" 455 " threshold= threshold (in microseconds) when playback starts\n" 456#endif 457#ifdef CONFIG_AUDIO_COREAUDIO 458 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 459 " in|out.buffer-count= number of buffers\n" 460#endif 461#ifdef CONFIG_AUDIO_DSOUND 462 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 463 " latency= add extra latency to playback in microseconds\n" 464#endif 465#ifdef CONFIG_AUDIO_OSS 466 "-audiodev oss,id=id[,prop[=value][,...]]\n" 467 " in|out.dev= path of the audio device to use\n" 468 " in|out.buffer-count= number of buffers\n" 469 " in|out.try-poll= attempt to use poll mode\n" 470 " try-mmap= try using memory mapped access\n" 471 " exclusive= open device in exclusive mode\n" 472 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 473#endif 474#ifdef CONFIG_AUDIO_PA 475 "-audiodev pa,id=id[,prop[=value][,...]]\n" 476 " server= PulseAudio server address\n" 477 " in|out.name= source/sink device name\n" 478 " in|out.latency= desired latency in microseconds\n" 479#endif 480#ifdef CONFIG_AUDIO_SDL 481 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 482#endif 483#ifdef CONFIG_SPICE 484 "-audiodev spice,id=id[,prop[=value][,...]]\n" 485#endif 486 "-audiodev wav,id=id[,prop[=value][,...]]\n" 487 " path= path of wav file to record\n", 488 QEMU_ARCH_ALL) 489STEXI 490@item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]] 491@findex -audiodev 492Adds a new audio backend @var{driver} identified by @var{id}. There are 493global and driver specific properties. Some values can be set 494differently for input and output, they're marked with @code{in|out.}. 495You can set the input's property with @code{in.@var{prop}} and the 496output's property with @code{out.@var{prop}}. For example: 497@example 498-audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 499-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 500@end example 501 502NOTE: parameter validation is known to be incomplete, in many cases 503specifying an invalid option causes QEMU to print an error message and 504continue emulation without sound. 505 506Valid global options are: 507 508@table @option 509@item id=@var{identifier} 510Identifies the audio backend. 511 512@item timer-period=@var{period} 513Sets the timer @var{period} used by the audio subsystem in microseconds. 514Default is 10000 (10 ms). 515 516@item in|out.mixing-engine=on|off 517Use QEMU's mixing engine to mix all streams inside QEMU and convert 518audio formats when not supported by the backend. When off, 519@var{fixed-settings} must be off too. Note that disabling this option 520means that the selected backend must support multiple streams and the 521audio formats used by the virtual cards, otherwise you'll get no sound. 522It's not recommended to disable this option unless you want to use 5.1 523or 7.1 audio, as mixing engine only supports mono and stereo audio. 524Default is on. 525 526@item in|out.fixed-settings=on|off 527Use fixed settings for host audio. When off, it will change based on 528how the guest opens the sound card. In this case you must not specify 529@var{frequency}, @var{channels} or @var{format}. Default is on. 530 531@item in|out.frequency=@var{frequency} 532Specify the @var{frequency} to use when using @var{fixed-settings}. 533Default is 44100Hz. 534 535@item in|out.channels=@var{channels} 536Specify the number of @var{channels} to use when using 537@var{fixed-settings}. Default is 2 (stereo). 538 539@item in|out.format=@var{format} 540Specify the sample @var{format} to use when using @var{fixed-settings}. 541Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8}, 542@code{u16}, @code{u32}. Default is @code{s16}. 543 544@item in|out.voices=@var{voices} 545Specify the number of @var{voices} to use. Default is 1. 546 547@item in|out.buffer-length=@var{usecs} 548Sets the size of the buffer in microseconds. 549 550@end table 551 552@item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]] 553Creates a dummy backend that discards all outputs. This backend has no 554backend specific properties. 555 556@item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 557Creates backend using the ALSA. This backend is only available on 558Linux. 559 560ALSA specific options are: 561 562@table @option 563 564@item in|out.dev=@var{device} 565Specify the ALSA @var{device} to use for input and/or output. Default 566is @code{default}. 567 568@item in|out.period-length=@var{usecs} 569Sets the period length in microseconds. 570 571@item in|out.try-poll=on|off 572Attempt to use poll mode with the device. Default is on. 573 574@item threshold=@var{threshold} 575Threshold (in microseconds) when playback starts. Default is 0. 576 577@end table 578 579@item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]] 580Creates a backend using Apple's Core Audio. This backend is only 581available on Mac OS and only supports playback. 582 583Core Audio specific options are: 584 585@table @option 586 587@item in|out.buffer-count=@var{count} 588Sets the @var{count} of the buffers. 589 590@end table 591 592@item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]] 593Creates a backend using Microsoft's DirectSound. This backend is only 594available on Windows and only supports playback. 595 596DirectSound specific options are: 597 598@table @option 599 600@item latency=@var{usecs} 601Add extra @var{usecs} microseconds latency to playback. Default is 60210000 (10 ms). 603 604@end table 605 606@item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]] 607Creates a backend using OSS. This backend is available on most 608Unix-like systems. 609 610OSS specific options are: 611 612@table @option 613 614@item in|out.dev=@var{device} 615Specify the file name of the OSS @var{device} to use. Default is 616@code{/dev/dsp}. 617 618@item in|out.buffer-count=@var{count} 619Sets the @var{count} of the buffers. 620 621@item in|out.try-poll=on|of 622Attempt to use poll mode with the device. Default is on. 623 624@item try-mmap=on|off 625Try using memory mapped device access. Default is off. 626 627@item exclusive=on|off 628Open the device in exclusive mode (vmix won't work in this case). 629Default is off. 630 631@item dsp-policy=@var{policy} 632Sets the timing policy (between 0 and 10, where smaller number means 633smaller latency but higher CPU usage). Use -1 to use buffer sizes 634specified by @code{buffer} and @code{buffer-count}. This option is 635ignored if you do not have OSS 4. Default is 5. 636 637@end table 638 639@item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 640Creates a backend using PulseAudio. This backend is available on most 641systems. 642 643PulseAudio specific options are: 644 645@table @option 646 647@item server=@var{server} 648Sets the PulseAudio @var{server} to connect to. 649 650@item in|out.name=@var{sink} 651Use the specified source/sink for recording/playback. 652 653@item in|out.latency=@var{usecs} 654Desired latency in microseconds. The PulseAudio server will try to honor this 655value but actual latencies may be lower or higher. 656 657@end table 658 659@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]] 660Creates a backend using SDL. This backend is available on most systems, 661but you should use your platform's native backend if possible. This 662backend has no backend specific properties. 663 664@item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]] 665Creates a backend that sends audio through SPICE. This backend requires 666@code{-spice} and automatically selected in that case, so usually you 667can ignore this option. This backend has no backend specific 668properties. 669 670@item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]] 671Creates a backend that writes audio to a WAV file. 672 673Backend specific options are: 674 675@table @option 676 677@item path=@var{path} 678Write recorded audio into the specified file. Default is 679@code{qemu.wav}. 680 681@end table 682ETEXI 683 684DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 685 "-soundhw c1,... enable audio support\n" 686 " and only specified sound cards (comma separated list)\n" 687 " use '-soundhw help' to get the list of supported cards\n" 688 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 689STEXI 690@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 691@findex -soundhw 692Enable audio and selected sound hardware. Use 'help' to print all 693available sound hardware. For example: 694 695@example 696@value{qemu_system_x86} -soundhw sb16,adlib disk.img 697@value{qemu_system_x86} -soundhw es1370 disk.img 698@value{qemu_system_x86} -soundhw ac97 disk.img 699@value{qemu_system_x86} -soundhw hda disk.img 700@value{qemu_system_x86} -soundhw all disk.img 701@value{qemu_system_x86} -soundhw help 702@end example 703 704Note that Linux's i810_audio OSS kernel (for AC97) module might 705require manually specifying clocking. 706 707@example 708modprobe i810_audio clocking=48000 709@end example 710ETEXI 711 712DEF("device", HAS_ARG, QEMU_OPTION_device, 713 "-device driver[,prop[=value][,...]]\n" 714 " add device (based on driver)\n" 715 " prop=value,... sets driver properties\n" 716 " use '-device help' to print all possible drivers\n" 717 " use '-device driver,help' to print all possible properties\n", 718 QEMU_ARCH_ALL) 719STEXI 720@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 721@findex -device 722Add device @var{driver}. @var{prop}=@var{value} sets driver 723properties. Valid properties depend on the driver. To get help on 724possible drivers and properties, use @code{-device help} and 725@code{-device @var{driver},help}. 726 727Some drivers are: 728@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}] 729 730Add an IPMI BMC. This is a simulation of a hardware management 731interface processor that normally sits on a system. It provides 732a watchdog and the ability to reset and power control the system. 733You need to connect this to an IPMI interface to make it useful 734 735The IPMI slave address to use for the BMC. The default is 0x20. 736This address is the BMC's address on the I2C network of management 737controllers. If you don't know what this means, it is safe to ignore 738it. 739 740@table @option 741@item id=@var{id} 742The BMC id for interfaces to use this device. 743@item slave_addr=@var{val} 744Define slave address to use for the BMC. The default is 0x20. 745@item sdrfile=@var{file} 746file containing raw Sensor Data Records (SDR) data. The default is none. 747@item fruareasize=@var{val} 748size of a Field Replaceable Unit (FRU) area. The default is 1024. 749@item frudatafile=@var{file} 750file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 751@item guid=@var{uuid} 752value for the GUID for the BMC, in standard UUID format. If this is set, 753get "Get GUID" command to the BMC will return it. Otherwise "Get GUID" 754will return an error. 755@end table 756 757@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 758 759Add a connection to an external IPMI BMC simulator. Instead of 760locally emulating the BMC like the above item, instead connect 761to an external entity that provides the IPMI services. 762 763A connection is made to an external BMC simulator. If you do this, it 764is strongly recommended that you use the "reconnect=" chardev option 765to reconnect to the simulator if the connection is lost. Note that if 766this is not used carefully, it can be a security issue, as the 767interface has the ability to send resets, NMIs, and power off the VM. 768It's best if QEMU makes a connection to an external simulator running 769on a secure port on localhost, so neither the simulator nor QEMU is 770exposed to any outside network. 771 772See the "lanserv/README.vm" file in the OpenIPMI library for more 773details on the external interface. 774 775@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 776 777Add a KCS IPMI interafce on the ISA bus. This also adds a 778corresponding ACPI and SMBIOS entries, if appropriate. 779 780@table @option 781@item bmc=@var{id} 782The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 783@item ioport=@var{val} 784Define the I/O address of the interface. The default is 0xca0 for KCS. 785@item irq=@var{val} 786Define the interrupt to use. The default is 5. To disable interrupts, 787set this to 0. 788@end table 789 790@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 791 792Like the KCS interface, but defines a BT interface. The default port is 7930xe4 and the default interrupt is 5. 794 795ETEXI 796 797DEF("name", HAS_ARG, QEMU_OPTION_name, 798 "-name string1[,process=string2][,debug-threads=on|off]\n" 799 " set the name of the guest\n" 800 " string1 sets the window title and string2 the process name\n" 801 " When debug-threads is enabled, individual threads are given a separate name\n" 802 " NOTE: The thread names are for debugging and not a stable API.\n", 803 QEMU_ARCH_ALL) 804STEXI 805@item -name @var{name} 806@findex -name 807Sets the @var{name} of the guest. 808This name will be displayed in the SDL window caption. 809The @var{name} will also be used for the VNC server. 810Also optionally set the top visible process name in Linux. 811Naming of individual threads can also be enabled on Linux to aid debugging. 812ETEXI 813 814DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 815 "-uuid %08x-%04x-%04x-%04x-%012x\n" 816 " specify machine UUID\n", QEMU_ARCH_ALL) 817STEXI 818@item -uuid @var{uuid} 819@findex -uuid 820Set system UUID. 821ETEXI 822 823STEXI 824@end table 825ETEXI 826DEFHEADING() 827 828DEFHEADING(Block device options:) 829STEXI 830@table @option 831ETEXI 832 833DEF("fda", HAS_ARG, QEMU_OPTION_fda, 834 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 835DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 836STEXI 837@item -fda @var{file} 838@itemx -fdb @var{file} 839@findex -fda 840@findex -fdb 841Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 842ETEXI 843 844DEF("hda", HAS_ARG, QEMU_OPTION_hda, 845 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 846DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 847DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 848 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 849DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 850STEXI 851@item -hda @var{file} 852@itemx -hdb @var{file} 853@itemx -hdc @var{file} 854@itemx -hdd @var{file} 855@findex -hda 856@findex -hdb 857@findex -hdc 858@findex -hdd 859Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 860ETEXI 861 862DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 863 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 864 QEMU_ARCH_ALL) 865STEXI 866@item -cdrom @var{file} 867@findex -cdrom 868Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 869@option{-cdrom} at the same time). You can use the host CD-ROM by 870using @file{/dev/cdrom} as filename (@pxref{host_drives}). 871ETEXI 872 873DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 874 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 875 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 876 " [,read-only=on|off][,auto-read-only=on|off]\n" 877 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 878 " [,driver specific parameters...]\n" 879 " configure a block backend\n", QEMU_ARCH_ALL) 880STEXI 881@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 882@findex -blockdev 883 884Define a new block driver node. Some of the options apply to all block drivers, 885other options are only accepted for a specific block driver. See below for a 886list of generic options and options for the most common block drivers. 887 888Options that expect a reference to another node (e.g. @code{file}) can be 889given in two ways. Either you specify the node name of an already existing node 890(file=@var{node-name}), or you define a new node inline, adding options 891for the referenced node after a dot (file.filename=@var{path},file.aio=native). 892 893A block driver node created with @option{-blockdev} can be used for a guest 894device by specifying its node name for the @code{drive} property in a 895@option{-device} argument that defines a block device. 896 897@table @option 898@item Valid options for any block driver node: 899 900@table @code 901@item driver 902Specifies the block driver to use for the given node. 903@item node-name 904This defines the name of the block driver node by which it will be referenced 905later. The name must be unique, i.e. it must not match the name of a different 906block driver node, or (if you use @option{-drive} as well) the ID of a drive. 907 908If no node name is specified, it is automatically generated. The generated node 909name is not intended to be predictable and changes between QEMU invocations. 910For the top level, an explicit node name must be specified. 911@item read-only 912Open the node read-only. Guest write attempts will fail. 913 914Note that some block drivers support only read-only access, either generally or 915in certain configurations. In this case, the default value 916@option{read-only=off} does not work and the option must be specified 917explicitly. 918@item auto-read-only 919If @option{auto-read-only=on} is set, QEMU may fall back to read-only usage 920even when @option{read-only=off} is requested, or even switch between modes as 921needed, e.g. depending on whether the image file is writable or whether a 922writing user is attached to the node. 923@item force-share 924Override the image locking system of QEMU by forcing the node to utilize 925weaker shared access for permissions where it would normally request exclusive 926access. When there is the potential for multiple instances to have the same 927file open (whether this invocation of QEMU is the first or the second 928instance), both instances must permit shared access for the second instance to 929succeed at opening the file. 930 931Enabling @option{force-share=on} requires @option{read-only=on}. 932@item cache.direct 933The host page cache can be avoided with @option{cache.direct=on}. This will 934attempt to do disk IO directly to the guest's memory. QEMU may still perform an 935internal copy of the data. 936@item cache.no-flush 937In case you don't care about data integrity over host failures, you can use 938@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 939any data to the disk but can instead keep things in cache. If anything goes 940wrong, like your host losing power, the disk storage getting disconnected 941accidentally, etc. your image will most probably be rendered unusable. 942@item discard=@var{discard} 943@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 944whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 945ignored or passed to the filesystem. Some machine types may not support 946discard requests. 947@item detect-zeroes=@var{detect-zeroes} 948@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 949conversion of plain zero writes by the OS to driver specific optimized 950zero write commands. You may even choose "unmap" if @var{discard} is set 951to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 952@end table 953 954@item Driver-specific options for @code{file} 955 956This is the protocol-level block driver for accessing regular files. 957 958@table @code 959@item filename 960The path to the image file in the local filesystem 961@item aio 962Specifies the AIO backend (threads/native, default: threads) 963@item locking 964Specifies whether the image file is protected with Linux OFD / POSIX locks. The 965default is to use the Linux Open File Descriptor API if available, otherwise no 966lock is applied. (auto/on/off, default: auto) 967@end table 968Example: 969@example 970-blockdev driver=file,node-name=disk,filename=disk.img 971@end example 972 973@item Driver-specific options for @code{raw} 974 975This is the image format block driver for raw images. It is usually 976stacked on top of a protocol level block driver such as @code{file}. 977 978@table @code 979@item file 980Reference to or definition of the data source block driver node 981(e.g. a @code{file} driver node) 982@end table 983Example 1: 984@example 985-blockdev driver=file,node-name=disk_file,filename=disk.img 986-blockdev driver=raw,node-name=disk,file=disk_file 987@end example 988Example 2: 989@example 990-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 991@end example 992 993@item Driver-specific options for @code{qcow2} 994 995This is the image format block driver for qcow2 images. It is usually 996stacked on top of a protocol level block driver such as @code{file}. 997 998@table @code 999@item file 1000Reference to or definition of the data source block driver node 1001(e.g. a @code{file} driver node) 1002 1003@item backing 1004Reference to or definition of the backing file block device (default is taken 1005from the image file). It is allowed to pass @code{null} here in order to disable 1006the default backing file. 1007 1008@item lazy-refcounts 1009Whether to enable the lazy refcounts feature (on/off; default is taken from the 1010image file) 1011 1012@item cache-size 1013The maximum total size of the L2 table and refcount block caches in bytes 1014(default: the sum of l2-cache-size and refcount-cache-size) 1015 1016@item l2-cache-size 1017The maximum size of the L2 table cache in bytes 1018(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 1019non-Linux platforms; otherwise, as large as possible within the cache-size, 1020while permitting the requested or the minimal refcount cache size) 1021 1022@item refcount-cache-size 1023The maximum size of the refcount block cache in bytes 1024(default: 4 times the cluster size; or if cache-size is specified, the part of 1025it which is not used for the L2 cache) 1026 1027@item cache-clean-interval 1028Clean unused entries in the L2 and refcount caches. The interval is in seconds. 1029The default value is 600 on supporting platforms, and 0 on other platforms. 1030Setting it to 0 disables this feature. 1031 1032@item pass-discard-request 1033Whether discard requests to the qcow2 device should be forwarded to the data 1034source (on/off; default: on if discard=unmap is specified, off otherwise) 1035 1036@item pass-discard-snapshot 1037Whether discard requests for the data source should be issued when a snapshot 1038operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 1039default: on) 1040 1041@item pass-discard-other 1042Whether discard requests for the data source should be issued on other 1043occasions where a cluster gets freed (on/off; default: off) 1044 1045@item overlap-check 1046Which overlap checks to perform for writes to the image 1047(none/constant/cached/all; default: cached). For details or finer 1048granularity control refer to the QAPI documentation of @code{blockdev-add}. 1049@end table 1050 1051Example 1: 1052@example 1053-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1054-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1055@end example 1056Example 2: 1057@example 1058-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1059@end example 1060 1061@item Driver-specific options for other drivers 1062Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1063 1064@end table 1065 1066ETEXI 1067 1068DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1069 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1070 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1071 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1072 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1073 " [,readonly=on|off][,copy-on-read=on|off]\n" 1074 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1075 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1076 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1077 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1078 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1079 " [[,iops_size=is]]\n" 1080 " [[,group=g]]\n" 1081 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1082STEXI 1083@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1084@findex -drive 1085 1086Define a new drive. This includes creating a block driver node (the backend) as 1087well as a guest device, and is mostly a shortcut for defining the corresponding 1088@option{-blockdev} and @option{-device} options. 1089 1090@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1091addition, it knows the following options: 1092 1093@table @option 1094@item file=@var{file} 1095This option defines which disk image (@pxref{disk_images}) to use with 1096this drive. If the filename contains comma, you must double it 1097(for instance, "file=my,,file" to use file "my,file"). 1098 1099Special files such as iSCSI devices can be specified using protocol 1100specific URLs. See the section for "Device URL Syntax" for more information. 1101@item if=@var{interface} 1102This option defines on which type on interface the drive is connected. 1103Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1104@item bus=@var{bus},unit=@var{unit} 1105These options define where is connected the drive by defining the bus number and 1106the unit id. 1107@item index=@var{index} 1108This option defines where is connected the drive by using an index in the list 1109of available connectors of a given interface type. 1110@item media=@var{media} 1111This option defines the type of the media: disk or cdrom. 1112@item snapshot=@var{snapshot} 1113@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1114(see @option{-snapshot}). 1115@item cache=@var{cache} 1116@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1117and controls how the host cache is used to access block data. This is a 1118shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1119options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1120which provides a default for the @option{write-cache} option of block guest 1121devices (as in @option{-device}). The modes correspond to the following 1122settings: 1123 1124@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1125@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1126@c and the HTML output. 1127@example 1128@ │ cache.writeback cache.direct cache.no-flush 1129─────────────┼───────────────────────────────────────────────── 1130writeback │ on off off 1131none │ on on off 1132writethrough │ off off off 1133directsync │ off on off 1134unsafe │ on off on 1135@end example 1136 1137The default mode is @option{cache=writeback}. 1138 1139@item aio=@var{aio} 1140@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1141@item format=@var{format} 1142Specify which disk @var{format} will be used rather than detecting 1143the format. Can be used to specify format=raw to avoid interpreting 1144an untrusted format header. 1145@item werror=@var{action},rerror=@var{action} 1146Specify which @var{action} to take on write and read errors. Valid actions are: 1147"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1148"report" (report the error to the guest), "enospc" (pause QEMU only if the 1149host disk is full; report the error to the guest otherwise). 1150The default setting is @option{werror=enospc} and @option{rerror=report}. 1151@item copy-on-read=@var{copy-on-read} 1152@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1153file sectors into the image file. 1154@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1155Specify bandwidth throttling limits in bytes per second, either for all request 1156types or for reads or writes only. Small values can lead to timeouts or hangs 1157inside the guest. A safe minimum for disks is 2 MB/s. 1158@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1159Specify bursts in bytes per second, either for all request types or for reads 1160or writes only. Bursts allow the guest I/O to spike above the limit 1161temporarily. 1162@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1163Specify request rate limits in requests per second, either for all request 1164types or for reads or writes only. 1165@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1166Specify bursts in requests per second, either for all request types or for reads 1167or writes only. Bursts allow the guest I/O to spike above the limit 1168temporarily. 1169@item iops_size=@var{is} 1170Let every @var{is} bytes of a request count as a new request for iops 1171throttling purposes. Use this option to prevent guests from circumventing iops 1172limits by sending fewer but larger requests. 1173@item group=@var{g} 1174Join a throttling quota group with given name @var{g}. All drives that are 1175members of the same group are accounted for together. Use this option to 1176prevent guests from circumventing throttling limits by using many small disks 1177instead of a single larger disk. 1178@end table 1179 1180By default, the @option{cache.writeback=on} mode is used. It will report data 1181writes as completed as soon as the data is present in the host page cache. 1182This is safe as long as your guest OS makes sure to correctly flush disk caches 1183where needed. If your guest OS does not handle volatile disk write caches 1184correctly and your host crashes or loses power, then the guest may experience 1185data corruption. 1186 1187For such guests, you should consider using @option{cache.writeback=off}. This 1188means that the host page cache will be used to read and write data, but write 1189notification will be sent to the guest only after QEMU has made sure to flush 1190each write to the disk. Be aware that this has a major impact on performance. 1191 1192When using the @option{-snapshot} option, unsafe caching is always used. 1193 1194Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1195useful when the backing file is over a slow network. By default copy-on-read 1196is off. 1197 1198Instead of @option{-cdrom} you can use: 1199@example 1200@value{qemu_system} -drive file=file,index=2,media=cdrom 1201@end example 1202 1203Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1204use: 1205@example 1206@value{qemu_system} -drive file=file,index=0,media=disk 1207@value{qemu_system} -drive file=file,index=1,media=disk 1208@value{qemu_system} -drive file=file,index=2,media=disk 1209@value{qemu_system} -drive file=file,index=3,media=disk 1210@end example 1211 1212You can open an image using pre-opened file descriptors from an fd set: 1213@example 1214@value{qemu_system} \ 1215 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 1216 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 1217 -drive file=/dev/fdset/2,index=0,media=disk 1218@end example 1219 1220You can connect a CDROM to the slave of ide0: 1221@example 1222@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom 1223@end example 1224 1225If you don't specify the "file=" argument, you define an empty drive: 1226@example 1227@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom 1228@end example 1229 1230Instead of @option{-fda}, @option{-fdb}, you can use: 1231@example 1232@value{qemu_system_x86} -drive file=file,index=0,if=floppy 1233@value{qemu_system_x86} -drive file=file,index=1,if=floppy 1234@end example 1235 1236By default, @var{interface} is "ide" and @var{index} is automatically 1237incremented: 1238@example 1239@value{qemu_system_x86} -drive file=a -drive file=b" 1240@end example 1241is interpreted like: 1242@example 1243@value{qemu_system_x86} -hda a -hdb b 1244@end example 1245ETEXI 1246 1247DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1248 "-mtdblock file use 'file' as on-board Flash memory image\n", 1249 QEMU_ARCH_ALL) 1250STEXI 1251@item -mtdblock @var{file} 1252@findex -mtdblock 1253Use @var{file} as on-board Flash memory image. 1254ETEXI 1255 1256DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1257 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1258STEXI 1259@item -sd @var{file} 1260@findex -sd 1261Use @var{file} as SecureDigital card image. 1262ETEXI 1263 1264DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1265 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1266STEXI 1267@item -pflash @var{file} 1268@findex -pflash 1269Use @var{file} as a parallel flash image. 1270ETEXI 1271 1272DEF("snapshot", 0, QEMU_OPTION_snapshot, 1273 "-snapshot write to temporary files instead of disk image files\n", 1274 QEMU_ARCH_ALL) 1275STEXI 1276@item -snapshot 1277@findex -snapshot 1278Write to temporary files instead of disk image files. In this case, 1279the raw disk image you use is not written back. You can however force 1280the write back by pressing @key{C-a s} (@pxref{disk_images}). 1281ETEXI 1282 1283DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1284 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1285 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1286 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1287 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1288 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1289 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1290 " [[,throttling.iops-size=is]]\n" 1291 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1292 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1293 "-fsdev synth,id=id\n", 1294 QEMU_ARCH_ALL) 1295 1296STEXI 1297 1298@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}[,...]]] 1299@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1300@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1301@itemx -fsdev synth,id=@var{id}[,readonly] 1302@findex -fsdev 1303Define a new file system device. Valid options are: 1304@table @option 1305@item local 1306Accesses to the filesystem are done by QEMU. 1307@item proxy 1308Accesses to the filesystem are done by virtfs-proxy-helper(1). 1309@item synth 1310Synthetic filesystem, only used by QTests. 1311@item id=@var{id} 1312Specifies identifier for this device. 1313@item path=@var{path} 1314Specifies the export path for the file system device. Files under 1315this path will be available to the 9p client on the guest. 1316@item security_model=@var{security_model} 1317Specifies the security model to be used for this export path. 1318Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1319In "passthrough" security model, files are stored using the same 1320credentials as they are created on the guest. This requires QEMU 1321to run as root. In "mapped-xattr" security model, some of the file 1322attributes like uid, gid, mode bits and link target are stored as 1323file attributes. For "mapped-file" these attributes are stored in the 1324hidden .virtfs_metadata directory. Directories exported by this security model cannot 1325interact with other unix tools. "none" security model is same as 1326passthrough except the sever won't report failures if it fails to 1327set file attributes like ownership. Security model is mandatory 1328only for local fsdriver. Other fsdrivers (like proxy) don't take 1329security model as a parameter. 1330@item writeout=@var{writeout} 1331This is an optional argument. The only supported value is "immediate". 1332This means that host page cache will be used to read and write data but 1333write notification will be sent to the guest only when the data has been 1334reported as written by the storage subsystem. 1335@item readonly 1336Enables exporting 9p share as a readonly mount for guests. By default 1337read-write access is given. 1338@item socket=@var{socket} 1339Enables proxy filesystem driver to use passed socket file for communicating 1340with virtfs-proxy-helper(1). 1341@item sock_fd=@var{sock_fd} 1342Enables proxy filesystem driver to use passed socket descriptor for 1343communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1344will create socketpair and pass one of the fds as sock_fd. 1345@item fmode=@var{fmode} 1346Specifies the default mode for newly created files on the host. Works only 1347with security models "mapped-xattr" and "mapped-file". 1348@item dmode=@var{dmode} 1349Specifies the default mode for newly created directories on the host. Works 1350only with security models "mapped-xattr" and "mapped-file". 1351@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1352Specify bandwidth throttling limits in bytes per second, either for all request 1353types or for reads or writes only. 1354@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1355Specify bursts in bytes per second, either for all request types or for reads 1356or writes only. Bursts allow the guest I/O to spike above the limit 1357temporarily. 1358@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1359Specify request rate limits in requests per second, either for all request 1360types or for reads or writes only. 1361@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1362Specify bursts in requests per second, either for all request types or for reads 1363or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1364@item throttling.iops-size=@var{is} 1365Let every @var{is} bytes of a request count as a new request for iops 1366throttling purposes. 1367@end table 1368 1369-fsdev option is used along with -device driver "virtio-9p-...". 1370@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1371Options for virtio-9p-... driver are: 1372@table @option 1373@item @var{type} 1374Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1375depending on the machine type. 1376@item fsdev=@var{id} 1377Specifies the id value specified along with -fsdev option. 1378@item mount_tag=@var{mount_tag} 1379Specifies the tag name to be used by the guest to mount this export point. 1380@end table 1381 1382ETEXI 1383 1384DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1385 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1386 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1387 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1388 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1389 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1390 QEMU_ARCH_ALL) 1391 1392STEXI 1393 1394@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}] 1395@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1396@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1397@itemx -virtfs synth,mount_tag=@var{mount_tag} 1398@findex -virtfs 1399 1400Define 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: 1401@table @option 1402@item local 1403Accesses to the filesystem are done by QEMU. 1404@item proxy 1405Accesses to the filesystem are done by virtfs-proxy-helper(1). 1406@item synth 1407Synthetic filesystem, only used by QTests. 1408@item id=@var{id} 1409Specifies identifier for the filesystem device 1410@item path=@var{path} 1411Specifies the export path for the file system device. Files under 1412this path will be available to the 9p client on the guest. 1413@item security_model=@var{security_model} 1414Specifies the security model to be used for this export path. 1415Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1416In "passthrough" security model, files are stored using the same 1417credentials as they are created on the guest. This requires QEMU 1418to run as root. In "mapped-xattr" security model, some of the file 1419attributes like uid, gid, mode bits and link target are stored as 1420file attributes. For "mapped-file" these attributes are stored in the 1421hidden .virtfs_metadata directory. Directories exported by this security model cannot 1422interact with other unix tools. "none" security model is same as 1423passthrough except the sever won't report failures if it fails to 1424set file attributes like ownership. Security model is mandatory only 1425for local fsdriver. Other fsdrivers (like proxy) don't take security 1426model as a parameter. 1427@item writeout=@var{writeout} 1428This is an optional argument. The only supported value is "immediate". 1429This means that host page cache will be used to read and write data but 1430write notification will be sent to the guest only when the data has been 1431reported as written by the storage subsystem. 1432@item readonly 1433Enables exporting 9p share as a readonly mount for guests. By default 1434read-write access is given. 1435@item socket=@var{socket} 1436Enables proxy filesystem driver to use passed socket file for 1437communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1438will create socketpair and pass one of the fds as sock_fd. 1439@item sock_fd 1440Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1441descriptor for interfacing with virtfs-proxy-helper(1). 1442@item fmode=@var{fmode} 1443Specifies the default mode for newly created files on the host. Works only 1444with security models "mapped-xattr" and "mapped-file". 1445@item dmode=@var{dmode} 1446Specifies the default mode for newly created directories on the host. Works 1447only with security models "mapped-xattr" and "mapped-file". 1448@item mount_tag=@var{mount_tag} 1449Specifies the tag name to be used by the guest to mount this export point. 1450@item multidevs=@var{multidevs} 1451Specifies how to deal with multiple devices being shared with a 9p export. 1452Supported behaviours are either "remap", "forbid" or "warn". The latter is 1453the default behaviour on which virtfs 9p expects only one device to be 1454shared with the same export, and if more than one device is shared and 1455accessed via the same 9p export then only a warning message is logged 1456(once) by qemu on host side. In order to avoid file ID collisions on guest 1457you should either create a separate virtfs export for each device to be 1458shared with guests (recommended way) or you might use "remap" instead which 1459allows you to share multiple devices with only one export instead, which is 1460achieved by remapping the original inode numbers from host to guest in a 1461way that would prevent such collisions. Remapping inodes in such use cases 1462is required because the original device IDs from host are never passed and 1463exposed on guest. Instead all files of an export shared with virtfs always 1464share the same device id on guest. So two files with identical inode 1465numbers but from actually different devices on host would otherwise cause a 1466file ID collision and hence potential misbehaviours on guest. "forbid" on 1467the other hand assumes like "warn" that only one device is shared by the 1468same export, however it will not only log a warning message but also 1469deny access to additional devices on guest. Note though that "forbid" does 1470currently not block all possible file access operations (e.g. readdir() 1471would still return entries from other devices). 1472@end table 1473ETEXI 1474 1475DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1476 "-iscsi [user=user][,password=password]\n" 1477 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1478 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1479 " [,timeout=timeout]\n" 1480 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1481 1482STEXI 1483@item -iscsi 1484@findex -iscsi 1485Configure iSCSI session parameters. 1486ETEXI 1487 1488STEXI 1489@end table 1490ETEXI 1491DEFHEADING() 1492 1493DEFHEADING(USB options:) 1494STEXI 1495@table @option 1496ETEXI 1497 1498DEF("usb", 0, QEMU_OPTION_usb, 1499 "-usb enable on-board USB host controller (if not enabled by default)\n", 1500 QEMU_ARCH_ALL) 1501STEXI 1502@item -usb 1503@findex -usb 1504Enable USB emulation on machine types with an on-board USB host controller (if 1505not enabled by default). Note that on-board USB host controllers may not 1506support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1507on machines with PCI. 1508ETEXI 1509 1510DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1511 "-usbdevice name add the host or guest USB device 'name'\n", 1512 QEMU_ARCH_ALL) 1513STEXI 1514 1515@item -usbdevice @var{devname} 1516@findex -usbdevice 1517Add the USB device @var{devname}. Note that this option is deprecated, 1518please use @code{-device usb-...} instead. @xref{usb_devices}. 1519 1520@table @option 1521 1522@item mouse 1523Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1524 1525@item tablet 1526Pointer device that uses absolute coordinates (like a touchscreen). This 1527means QEMU is able to report the mouse position without having to grab the 1528mouse. Also overrides the PS/2 mouse emulation when activated. 1529 1530@item braille 1531Braille device. This will use BrlAPI to display the braille output on a real 1532or fake device. 1533 1534@end table 1535ETEXI 1536 1537STEXI 1538@end table 1539ETEXI 1540DEFHEADING() 1541 1542DEFHEADING(Display options:) 1543STEXI 1544@table @option 1545ETEXI 1546 1547DEF("display", HAS_ARG, QEMU_OPTION_display, 1548#if defined(CONFIG_SPICE) 1549 "-display spice-app[,gl=on|off]\n" 1550#endif 1551#if defined(CONFIG_SDL) 1552 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n" 1553 " [,window_close=on|off][,gl=on|core|es|off]\n" 1554#endif 1555#if defined(CONFIG_GTK) 1556 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1557#endif 1558#if defined(CONFIG_VNC) 1559 "-display vnc=<display>[,<optargs>]\n" 1560#endif 1561#if defined(CONFIG_CURSES) 1562 "-display curses[,charset=<encoding>]\n" 1563#endif 1564#if defined(CONFIG_OPENGL) 1565 "-display egl-headless[,rendernode=<file>]\n" 1566#endif 1567 "-display none\n" 1568 " select display backend type\n" 1569 " The default display is equivalent to\n " 1570#if defined(CONFIG_GTK) 1571 "\"-display gtk\"\n" 1572#elif defined(CONFIG_SDL) 1573 "\"-display sdl\"\n" 1574#elif defined(CONFIG_COCOA) 1575 "\"-display cocoa\"\n" 1576#elif defined(CONFIG_VNC) 1577 "\"-vnc localhost:0,to=99,id=default\"\n" 1578#else 1579 "\"-display none\"\n" 1580#endif 1581 , QEMU_ARCH_ALL) 1582STEXI 1583@item -display @var{type} 1584@findex -display 1585Select type of display to use. This option is a replacement for the 1586old style -sdl/-curses/... options. Valid values for @var{type} are 1587@table @option 1588@item sdl 1589Display video output via SDL (usually in a separate graphics 1590window; see the SDL documentation for other possibilities). 1591@item curses 1592Display video output via curses. For graphics device models which 1593support a text mode, QEMU can display this output using a 1594curses/ncurses interface. Nothing is displayed when the graphics 1595device is in graphical mode or if the graphics device does not support 1596a text mode. Generally only the VGA device models support text mode. 1597The font charset used by the guest can be specified with the 1598@code{charset} option, for example @code{charset=CP850} for IBM CP850 1599encoding. The default is @code{CP437}. 1600@item none 1601Do not display video output. The guest will still see an emulated 1602graphics card, but its output will not be displayed to the QEMU 1603user. This option differs from the -nographic option in that it 1604only affects what is done with video output; -nographic also changes 1605the destination of the serial and parallel port data. 1606@item gtk 1607Display video output in a GTK window. This interface provides drop-down 1608menus and other UI elements to configure and control the VM during 1609runtime. 1610@item vnc 1611Start a VNC server on display <arg> 1612@item egl-headless 1613Offload all OpenGL operations to a local DRI device. For any graphical display, 1614this display needs to be paired with either VNC or SPICE displays. 1615@item spice-app 1616Start QEMU as a Spice server and launch the default Spice client 1617application. The Spice server will redirect the serial consoles and 1618QEMU monitors. (Since 4.0) 1619@end table 1620ETEXI 1621 1622DEF("nographic", 0, QEMU_OPTION_nographic, 1623 "-nographic disable graphical output and redirect serial I/Os to console\n", 1624 QEMU_ARCH_ALL) 1625STEXI 1626@item -nographic 1627@findex -nographic 1628Normally, if QEMU is compiled with graphical window support, it displays 1629output such as guest graphics, guest console, and the QEMU monitor in a 1630window. With this option, you can totally disable graphical output so 1631that QEMU is a simple command line application. The emulated serial port 1632is redirected on the console and muxed with the monitor (unless 1633redirected elsewhere explicitly). Therefore, you can still use QEMU to 1634debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1635switching between the console and monitor. 1636ETEXI 1637 1638DEF("curses", 0, QEMU_OPTION_curses, 1639 "-curses shorthand for -display curses\n", 1640 QEMU_ARCH_ALL) 1641STEXI 1642@item -curses 1643@findex -curses 1644Normally, if QEMU is compiled with graphical window support, it displays 1645output such as guest graphics, guest console, and the QEMU monitor in a 1646window. With this option, QEMU can display the VGA output when in text 1647mode using a curses/ncurses interface. Nothing is displayed in graphical 1648mode. 1649ETEXI 1650 1651DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1652 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1653 QEMU_ARCH_ALL) 1654STEXI 1655@item -alt-grab 1656@findex -alt-grab 1657Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1658affects the special keys (for fullscreen, monitor-mode switching, etc). 1659ETEXI 1660 1661DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1662 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1663 QEMU_ARCH_ALL) 1664STEXI 1665@item -ctrl-grab 1666@findex -ctrl-grab 1667Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1668affects the special keys (for fullscreen, monitor-mode switching, etc). 1669ETEXI 1670 1671DEF("no-quit", 0, QEMU_OPTION_no_quit, 1672 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1673STEXI 1674@item -no-quit 1675@findex -no-quit 1676Disable SDL window close capability. 1677ETEXI 1678 1679DEF("sdl", 0, QEMU_OPTION_sdl, 1680 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1681STEXI 1682@item -sdl 1683@findex -sdl 1684Enable SDL. 1685ETEXI 1686 1687DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1688 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1689 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1690 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1691 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1692 " [,tls-ciphers=<list>]\n" 1693 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1694 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1695 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1696 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1697 " [,jpeg-wan-compression=[auto|never|always]]\n" 1698 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1699 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1700 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1701 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1702 " [,gl=[on|off]][,rendernode=<file>]\n" 1703 " enable spice\n" 1704 " at least one of {port, tls-port} is mandatory\n", 1705 QEMU_ARCH_ALL) 1706STEXI 1707@item -spice @var{option}[,@var{option}[,...]] 1708@findex -spice 1709Enable the spice remote desktop protocol. Valid options are 1710 1711@table @option 1712 1713@item port=<nr> 1714Set the TCP port spice is listening on for plaintext channels. 1715 1716@item addr=<addr> 1717Set the IP address spice is listening on. Default is any address. 1718 1719@item ipv4 1720@itemx ipv6 1721@itemx unix 1722Force using the specified IP version. 1723 1724@item password=<secret> 1725Set the password you need to authenticate. 1726 1727@item sasl 1728Require that the client use SASL to authenticate with the spice. 1729The exact choice of authentication method used is controlled from the 1730system / user's SASL configuration file for the 'qemu' service. This 1731is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1732unprivileged user, an environment variable SASL_CONF_PATH can be used 1733to make it search alternate locations for the service config. 1734While some SASL auth methods can also provide data encryption (eg GSSAPI), 1735it is recommended that SASL always be combined with the 'tls' and 1736'x509' settings to enable use of SSL and server certificates. This 1737ensures a data encryption preventing compromise of authentication 1738credentials. 1739 1740@item disable-ticketing 1741Allow client connects without authentication. 1742 1743@item disable-copy-paste 1744Disable copy paste between the client and the guest. 1745 1746@item disable-agent-file-xfer 1747Disable spice-vdagent based file-xfer between the client and the guest. 1748 1749@item tls-port=<nr> 1750Set the TCP port spice is listening on for encrypted channels. 1751 1752@item x509-dir=<dir> 1753Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1754 1755@item x509-key-file=<file> 1756@itemx x509-key-password=<file> 1757@itemx x509-cert-file=<file> 1758@itemx x509-cacert-file=<file> 1759@itemx x509-dh-key-file=<file> 1760The x509 file names can also be configured individually. 1761 1762@item tls-ciphers=<list> 1763Specify which ciphers to use. 1764 1765@item tls-channel=[main|display|cursor|inputs|record|playback] 1766@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1767Force specific channel to be used with or without TLS encryption. The 1768options can be specified multiple times to configure multiple 1769channels. The special name "default" can be used to set the default 1770mode. For channels which are not explicitly forced into one mode the 1771spice client is allowed to pick tls/plaintext as he pleases. 1772 1773@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1774Configure image compression (lossless). 1775Default is auto_glz. 1776 1777@item jpeg-wan-compression=[auto|never|always] 1778@itemx zlib-glz-wan-compression=[auto|never|always] 1779Configure wan image compression (lossy for slow links). 1780Default is auto. 1781 1782@item streaming-video=[off|all|filter] 1783Configure video stream detection. Default is off. 1784 1785@item agent-mouse=[on|off] 1786Enable/disable passing mouse events via vdagent. Default is on. 1787 1788@item playback-compression=[on|off] 1789Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1790 1791@item seamless-migration=[on|off] 1792Enable/disable spice seamless migration. Default is off. 1793 1794@item gl=[on|off] 1795Enable/disable OpenGL context. Default is off. 1796 1797@item rendernode=<file> 1798DRM render node for OpenGL rendering. If not specified, it will pick 1799the first available. (Since 2.9) 1800 1801@end table 1802ETEXI 1803 1804DEF("portrait", 0, QEMU_OPTION_portrait, 1805 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1806 QEMU_ARCH_ALL) 1807STEXI 1808@item -portrait 1809@findex -portrait 1810Rotate graphical output 90 deg left (only PXA LCD). 1811ETEXI 1812 1813DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1814 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1815 QEMU_ARCH_ALL) 1816STEXI 1817@item -rotate @var{deg} 1818@findex -rotate 1819Rotate graphical output some deg left (only PXA LCD). 1820ETEXI 1821 1822DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1823 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1824 " select video card type\n", QEMU_ARCH_ALL) 1825STEXI 1826@item -vga @var{type} 1827@findex -vga 1828Select type of VGA card to emulate. Valid values for @var{type} are 1829@table @option 1830@item cirrus 1831Cirrus Logic GD5446 Video card. All Windows versions starting from 1832Windows 95 should recognize and use this graphic card. For optimal 1833performances, use 16 bit color depth in the guest and the host OS. 1834(This card was the default before QEMU 2.2) 1835@item std 1836Standard VGA card with Bochs VBE extensions. If your guest OS 1837supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1838to use high resolution modes (>= 1280x1024x16) then you should use 1839this option. (This card is the default since QEMU 2.2) 1840@item vmware 1841VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1842recent XFree86/XOrg server or Windows guest with a driver for this 1843card. 1844@item qxl 1845QXL paravirtual graphic card. It is VGA compatible (including VESA 18462.0 VBE support). Works best with qxl guest drivers installed though. 1847Recommended choice when using the spice protocol. 1848@item tcx 1849(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1850sun4m machines and offers both 8-bit and 24-bit colour depths at a 1851fixed resolution of 1024x768. 1852@item cg3 1853(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1854for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1855resolutions aimed at people wishing to run older Solaris versions. 1856@item virtio 1857Virtio VGA card. 1858@item none 1859Disable VGA card. 1860@end table 1861ETEXI 1862 1863DEF("full-screen", 0, QEMU_OPTION_full_screen, 1864 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1865STEXI 1866@item -full-screen 1867@findex -full-screen 1868Start in full screen. 1869ETEXI 1870 1871DEF("g", 1, QEMU_OPTION_g , 1872 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1873 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 1874STEXI 1875@item -g @var{width}x@var{height}[x@var{depth}] 1876@findex -g 1877Set the initial graphical resolution and depth (PPC, SPARC only). 1878ETEXI 1879 1880DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1881 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1882STEXI 1883@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1884@findex -vnc 1885Normally, if QEMU is compiled with graphical window support, it displays 1886output such as guest graphics, guest console, and the QEMU monitor in a 1887window. With this option, you can have QEMU listen on VNC display 1888@var{display} and redirect the VGA display over the VNC session. It is 1889very useful to enable the usb tablet device when using this option 1890(option @option{-device usb-tablet}). When using the VNC display, you 1891must use the @option{-k} parameter to set the keyboard layout if you are 1892not using en-us. Valid syntax for the @var{display} is 1893 1894@table @option 1895 1896@item to=@var{L} 1897 1898With this option, QEMU will try next available VNC @var{display}s, until the 1899number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1900available, e.g. port 5900+@var{display} is already used by another 1901application. By default, to=0. 1902 1903@item @var{host}:@var{d} 1904 1905TCP connections will only be allowed from @var{host} on display @var{d}. 1906By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1907be omitted in which case the server will accept connections from any host. 1908 1909@item unix:@var{path} 1910 1911Connections will be allowed over UNIX domain sockets where @var{path} is the 1912location of a unix socket to listen for connections on. 1913 1914@item none 1915 1916VNC is initialized but not started. The monitor @code{change} command 1917can be used to later start the VNC server. 1918 1919@end table 1920 1921Following the @var{display} value there may be one or more @var{option} flags 1922separated by commas. Valid options are 1923 1924@table @option 1925 1926@item reverse 1927 1928Connect to a listening VNC client via a ``reverse'' connection. The 1929client is specified by the @var{display}. For reverse network 1930connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1931is a TCP port number, not a display number. 1932 1933@item websocket 1934 1935Opens an additional TCP listening port dedicated to VNC Websocket connections. 1936If a bare @var{websocket} option is given, the Websocket port is 19375700+@var{display}. An alternative port can be specified with the 1938syntax @code{websocket}=@var{port}. 1939 1940If @var{host} is specified connections will only be allowed from this host. 1941It is possible to control the websocket listen address independently, using 1942the syntax @code{websocket}=@var{host}:@var{port}. 1943 1944If no TLS credentials are provided, the websocket connection runs in 1945unencrypted mode. If TLS credentials are provided, the websocket connection 1946requires encrypted client connections. 1947 1948@item password 1949 1950Require that password based authentication is used for client connections. 1951 1952The password must be set separately using the @code{set_password} command in 1953the @ref{pcsys_monitor}. The syntax to change your password is: 1954@code{set_password <protocol> <password>} where <protocol> could be either 1955"vnc" or "spice". 1956 1957If you would like to change <protocol> password expiration, you should use 1958@code{expire_password <protocol> <expiration-time>} where expiration time could 1959be one of the following options: now, never, +seconds or UNIX time of 1960expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1961to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1962date and time). 1963 1964You can also use keywords "now" or "never" for the expiration time to 1965allow <protocol> password to expire immediately or never expire. 1966 1967@item tls-creds=@var{ID} 1968 1969Provides the ID of a set of TLS credentials to use to secure the 1970VNC server. They will apply to both the normal VNC server socket 1971and the websocket socket (if enabled). Setting TLS credentials 1972will cause the VNC server socket to enable the VeNCrypt auth 1973mechanism. The credentials should have been previously created 1974using the @option{-object tls-creds} argument. 1975 1976@item tls-authz=@var{ID} 1977 1978Provides the ID of the QAuthZ authorization object against which 1979the client's x509 distinguished name will validated. This object is 1980only resolved at time of use, so can be deleted and recreated on the 1981fly while the VNC server is active. If missing, it will default 1982to denying access. 1983 1984@item sasl 1985 1986Require that the client use SASL to authenticate with the VNC server. 1987The exact choice of authentication method used is controlled from the 1988system / user's SASL configuration file for the 'qemu' service. This 1989is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1990unprivileged user, an environment variable SASL_CONF_PATH can be used 1991to make it search alternate locations for the service config. 1992While some SASL auth methods can also provide data encryption (eg GSSAPI), 1993it is recommended that SASL always be combined with the 'tls' and 1994'x509' settings to enable use of SSL and server certificates. This 1995ensures a data encryption preventing compromise of authentication 1996credentials. See the @ref{vnc_security} section for details on using 1997SASL authentication. 1998 1999@item sasl-authz=@var{ID} 2000 2001Provides the ID of the QAuthZ authorization object against which 2002the client's SASL username will validated. This object is 2003only resolved at time of use, so can be deleted and recreated on the 2004fly while the VNC server is active. If missing, it will default 2005to denying access. 2006 2007@item acl 2008 2009Legacy method for enabling authorization of clients against the 2010x509 distinguished name and SASL username. It results in the creation 2011of two @code{authz-list} objects with IDs of @code{vnc.username} and 2012@code{vnc.x509dname}. The rules for these objects must be configured 2013with the HMP ACL commands. 2014 2015This option is deprecated and should no longer be used. The new 2016@option{sasl-authz} and @option{tls-authz} options are a 2017replacement. 2018 2019@item lossy 2020 2021Enable lossy compression methods (gradient, JPEG, ...). If this 2022option is set, VNC client may receive lossy framebuffer updates 2023depending on its encoding settings. Enabling this option can save 2024a lot of bandwidth at the expense of quality. 2025 2026@item non-adaptive 2027 2028Disable adaptive encodings. Adaptive encodings are enabled by default. 2029An adaptive encoding will try to detect frequently updated screen regions, 2030and send updates in these regions using a lossy encoding (like JPEG). 2031This can be really helpful to save bandwidth when playing videos. Disabling 2032adaptive encodings restores the original static behavior of encodings 2033like Tight. 2034 2035@item share=[allow-exclusive|force-shared|ignore] 2036 2037Set display sharing policy. 'allow-exclusive' allows clients to ask 2038for exclusive access. As suggested by the rfb spec this is 2039implemented by dropping other connections. Connecting multiple 2040clients in parallel requires all clients asking for a shared session 2041(vncviewer: -shared switch). This is the default. 'force-shared' 2042disables exclusive client access. Useful for shared desktop sessions, 2043where you don't want someone forgetting specify -shared disconnect 2044everybody else. 'ignore' completely ignores the shared flag and 2045allows everybody connect unconditionally. Doesn't conform to the rfb 2046spec but is traditional QEMU behavior. 2047 2048@item key-delay-ms 2049 2050Set keyboard delay, for key down and key up events, in milliseconds. 2051Default is 10. Keyboards are low-bandwidth devices, so this slowdown 2052can help the device and guest to keep up and not lose events in case 2053events are arriving in bulk. Possible causes for the latter are flaky 2054network connections, or scripts for automated testing. 2055 2056@item audiodev=@var{audiodev} 2057 2058Use the specified @var{audiodev} when the VNC client requests audio 2059transmission. When not using an -audiodev argument, this option must 2060be omitted, otherwise is must be present and specify a valid audiodev. 2061 2062@end table 2063ETEXI 2064 2065STEXI 2066@end table 2067ETEXI 2068ARCHHEADING(, QEMU_ARCH_I386) 2069 2070ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2071STEXI 2072@table @option 2073ETEXI 2074 2075DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2076 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2077 QEMU_ARCH_I386) 2078STEXI 2079@item -win2k-hack 2080@findex -win2k-hack 2081Use it when installing Windows 2000 to avoid a disk full bug. After 2082Windows 2000 is installed, you no longer need this option (this option 2083slows down the IDE transfers). 2084ETEXI 2085 2086DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2087 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2088 QEMU_ARCH_I386) 2089STEXI 2090@item -no-fd-bootchk 2091@findex -no-fd-bootchk 2092Disable boot signature checking for floppy disks in BIOS. May 2093be needed to boot from old floppy disks. 2094ETEXI 2095 2096DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2097 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2098STEXI 2099@item -no-acpi 2100@findex -no-acpi 2101Disable ACPI (Advanced Configuration and Power Interface) support. Use 2102it if your guest OS complains about ACPI problems (PC target machine 2103only). 2104ETEXI 2105 2106DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2107 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2108STEXI 2109@item -no-hpet 2110@findex -no-hpet 2111Disable HPET support. 2112ETEXI 2113 2114DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2115 "-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" 2116 " ACPI table description\n", QEMU_ARCH_I386) 2117STEXI 2118@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}]...] 2119@findex -acpitable 2120Add ACPI table with specified header fields and context from specified files. 2121For file=, take whole ACPI table from the specified files, including all 2122ACPI headers (possible overridden by other options). 2123For data=, only data 2124portion of the table is used, all header information is specified in the 2125command line. 2126If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2127fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2128to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2129spec. 2130ETEXI 2131 2132DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2133 "-smbios file=binary\n" 2134 " load SMBIOS entry from binary file\n" 2135 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2136 " [,uefi=on|off]\n" 2137 " specify SMBIOS type 0 fields\n" 2138 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2139 " [,uuid=uuid][,sku=str][,family=str]\n" 2140 " specify SMBIOS type 1 fields\n" 2141 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2142 " [,asset=str][,location=str]\n" 2143 " specify SMBIOS type 2 fields\n" 2144 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2145 " [,sku=str]\n" 2146 " specify SMBIOS type 3 fields\n" 2147 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2148 " [,asset=str][,part=str]\n" 2149 " specify SMBIOS type 4 fields\n" 2150 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2151 " [,asset=str][,part=str][,speed=%d]\n" 2152 " specify SMBIOS type 17 fields\n", 2153 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2154STEXI 2155@item -smbios file=@var{binary} 2156@findex -smbios 2157Load SMBIOS entry from binary file. 2158 2159@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2160Specify SMBIOS type 0 fields 2161 2162@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}] 2163Specify SMBIOS type 1 fields 2164 2165@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2166Specify SMBIOS type 2 fields 2167 2168@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2169Specify SMBIOS type 3 fields 2170 2171@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2172Specify SMBIOS type 4 fields 2173 2174@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}] 2175Specify SMBIOS type 17 fields 2176ETEXI 2177 2178STEXI 2179@end table 2180ETEXI 2181DEFHEADING() 2182 2183DEFHEADING(Network options:) 2184STEXI 2185@table @option 2186ETEXI 2187 2188DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2189#ifdef CONFIG_SLIRP 2190 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2191 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2192 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2193 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2194 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2195#ifndef _WIN32 2196 "[,smb=dir[,smbserver=addr]]\n" 2197#endif 2198 " configure a user mode network backend with ID 'str',\n" 2199 " its DHCP server and optional services\n" 2200#endif 2201#ifdef _WIN32 2202 "-netdev tap,id=str,ifname=name\n" 2203 " configure a host TAP network backend with ID 'str'\n" 2204#else 2205 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2206 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2207 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2208 " [,poll-us=n]\n" 2209 " configure a host TAP network backend with ID 'str'\n" 2210 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2211 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2212 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2213 " to deconfigure it\n" 2214 " use '[down]script=no' to disable script execution\n" 2215 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2216 " configure it\n" 2217 " use 'fd=h' to connect to an already opened TAP interface\n" 2218 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2219 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2220 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2221 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2222 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2223 " use vhost=on to enable experimental in kernel accelerator\n" 2224 " (only has effect for virtio guests which use MSIX)\n" 2225 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2226 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2227 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2228 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2229 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2230 " spent on busy polling for vhost net\n" 2231 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2232 " configure a host TAP network backend with ID 'str' that is\n" 2233 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2234 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2235#endif 2236#ifdef __linux__ 2237 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2238 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2239 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2240 " [,rxcookie=rxcookie][,offset=offset]\n" 2241 " configure a network backend with ID 'str' connected to\n" 2242 " an Ethernet over L2TPv3 pseudowire.\n" 2243 " Linux kernel 3.3+ as well as most routers can talk\n" 2244 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2245 " VM to a router and even VM to Host. It is a nearly-universal\n" 2246 " standard (RFC3391). Note - this implementation uses static\n" 2247 " pre-configured tunnels (same as the Linux kernel).\n" 2248 " use 'src=' to specify source address\n" 2249 " use 'dst=' to specify destination address\n" 2250 " use 'udp=on' to specify udp encapsulation\n" 2251 " use 'srcport=' to specify source udp port\n" 2252 " use 'dstport=' to specify destination udp port\n" 2253 " use 'ipv6=on' to force v6\n" 2254 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2255 " well as a weak security measure\n" 2256 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2257 " use 'txcookie=0x012345678' to specify a txcookie\n" 2258 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2259 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2260 " use 'pincounter=on' to work around broken counter handling in peer\n" 2261 " use 'offset=X' to add an extra offset between header and data\n" 2262#endif 2263 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2264 " configure a network backend to connect to another network\n" 2265 " using a socket connection\n" 2266 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2267 " configure a network backend to connect to a multicast maddr and port\n" 2268 " use 'localaddr=addr' to specify the host address to send packets from\n" 2269 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2270 " configure a network backend to connect to another network\n" 2271 " using an UDP tunnel\n" 2272#ifdef CONFIG_VDE 2273 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2274 " configure a network backend to connect to port 'n' of a vde switch\n" 2275 " running on host and listening for incoming connections on 'socketpath'.\n" 2276 " Use group 'groupname' and mode 'octalmode' to change default\n" 2277 " ownership and permissions for communication port.\n" 2278#endif 2279#ifdef CONFIG_NETMAP 2280 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2281 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2282 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2283 " netmap device, defaults to '/dev/netmap')\n" 2284#endif 2285#ifdef CONFIG_POSIX 2286 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2287 " configure a vhost-user network, backed by a chardev 'dev'\n" 2288#endif 2289 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2290 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2291DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2292 "-nic [tap|bridge|" 2293#ifdef CONFIG_SLIRP 2294 "user|" 2295#endif 2296#ifdef __linux__ 2297 "l2tpv3|" 2298#endif 2299#ifdef CONFIG_VDE 2300 "vde|" 2301#endif 2302#ifdef CONFIG_NETMAP 2303 "netmap|" 2304#endif 2305#ifdef CONFIG_POSIX 2306 "vhost-user|" 2307#endif 2308 "socket][,option][,...][mac=macaddr]\n" 2309 " initialize an on-board / default host NIC (using MAC address\n" 2310 " macaddr) and connect it to the given host network backend\n" 2311 "-nic none use it alone to have zero network devices (the default is to\n" 2312 " provided a 'user' network connection)\n", 2313 QEMU_ARCH_ALL) 2314DEF("net", HAS_ARG, QEMU_OPTION_net, 2315 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2316 " configure or create an on-board (or machine default) NIC and\n" 2317 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2318 "-net [" 2319#ifdef CONFIG_SLIRP 2320 "user|" 2321#endif 2322 "tap|" 2323 "bridge|" 2324#ifdef CONFIG_VDE 2325 "vde|" 2326#endif 2327#ifdef CONFIG_NETMAP 2328 "netmap|" 2329#endif 2330 "socket][,option][,option][,...]\n" 2331 " old way to initialize a host network interface\n" 2332 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2333STEXI 2334@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2335@findex -nic 2336This option is a shortcut for configuring both the on-board (default) guest 2337NIC hardware and the host network backend in one go. The host backend options 2338are the same as with the corresponding @option{-netdev} options below. 2339The guest NIC model can be set with @option{model=@var{modelname}}. 2340Use @option{model=help} to list the available device types. 2341The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2342 2343The following two example do exactly the same, to show how @option{-nic} can 2344be used to shorten the command line length (note that the e1000 is the default 2345on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2346@example 2347@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2348@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2349@end example 2350 2351@item -nic none 2352Indicate that no network devices should be configured. It is used to override 2353the default configuration (default NIC with ``user'' host network backend) 2354which is activated if no other networking options are provided. 2355 2356@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2357@findex -netdev 2358Configure user mode host network backend which requires no administrator 2359privilege to run. Valid options are: 2360 2361@table @option 2362@item id=@var{id} 2363Assign symbolic name for use in monitor commands. 2364 2365@item ipv4=on|off and ipv6=on|off 2366Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2367both protocols are enabled. 2368 2369@item net=@var{addr}[/@var{mask}] 2370Set IP network address the guest will see. Optionally specify the netmask, 2371either in the form a.b.c.d or as number of valid top-most bits. Default is 237210.0.2.0/24. 2373 2374@item host=@var{addr} 2375Specify the guest-visible address of the host. Default is the 2nd IP in the 2376guest network, i.e. x.x.x.2. 2377 2378@item ipv6-net=@var{addr}[/@var{int}] 2379Set IPv6 network address the guest will see (default is fec0::/64). The 2380network prefix is given in the usual hexadecimal IPv6 address 2381notation. The prefix size is optional, and is given as the number of 2382valid top-most bits (default is 64). 2383 2384@item ipv6-host=@var{addr} 2385Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2386the guest network, i.e. xxxx::2. 2387 2388@item restrict=on|off 2389If this option is enabled, the guest will be isolated, i.e. it will not be 2390able to contact the host and no guest IP packets will be routed over the host 2391to the outside. This option does not affect any explicitly set forwarding rules. 2392 2393@item hostname=@var{name} 2394Specifies the client hostname reported by the built-in DHCP server. 2395 2396@item dhcpstart=@var{addr} 2397Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2398is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2399 2400@item dns=@var{addr} 2401Specify the guest-visible address of the virtual nameserver. The address must 2402be different from the host address. Default is the 3rd IP in the guest network, 2403i.e. x.x.x.3. 2404 2405@item ipv6-dns=@var{addr} 2406Specify the guest-visible address of the IPv6 virtual nameserver. The address 2407must be different from the host address. Default is the 3rd IP in the guest 2408network, i.e. xxxx::3. 2409 2410@item dnssearch=@var{domain} 2411Provides an entry for the domain-search list sent by the built-in 2412DHCP server. More than one domain suffix can be transmitted by specifying 2413this option multiple times. If supported, this will cause the guest to 2414automatically try to append the given domain suffix(es) in case a domain name 2415can not be resolved. 2416 2417Example: 2418@example 2419@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2420@end example 2421 2422@item domainname=@var{domain} 2423Specifies the client domain name reported by the built-in DHCP server. 2424 2425@item tftp=@var{dir} 2426When using the user mode network stack, activate a built-in TFTP 2427server. The files in @var{dir} will be exposed as the root of a TFTP server. 2428The TFTP client on the guest must be configured in binary mode (use the command 2429@code{bin} of the Unix TFTP client). 2430 2431@item tftp-server-name=@var{name} 2432In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 243366). This can be used to advise the guest to load boot files or configurations 2434from a different server than the host address. 2435 2436@item bootfile=@var{file} 2437When using the user mode network stack, broadcast @var{file} as the BOOTP 2438filename. In conjunction with @option{tftp}, this can be used to network boot 2439a guest from a local directory. 2440 2441Example (using pxelinux): 2442@example 2443@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2444 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2445@end example 2446 2447@item smb=@var{dir}[,smbserver=@var{addr}] 2448When using the user mode network stack, activate a built-in SMB 2449server so that Windows OSes can access to the host files in @file{@var{dir}} 2450transparently. The IP address of the SMB server can be set to @var{addr}. By 2451default the 4th IP in the guest network is used, i.e. x.x.x.4. 2452 2453In the guest Windows OS, the line: 2454@example 245510.0.2.4 smbserver 2456@end example 2457must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2458or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2459 2460Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2461 2462Note that a SAMBA server must be installed on the host OS. 2463 2464@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2465Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2466the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2467@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2468given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2469be bound to a specific host interface. If no connection type is set, TCP is 2470used. This option can be given multiple times. 2471 2472For example, to redirect host X11 connection from screen 1 to guest 2473screen 0, use the following: 2474 2475@example 2476# on the host 2477@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2478# this host xterm should open in the guest X11 server 2479xterm -display :1 2480@end example 2481 2482To redirect telnet connections from host port 5555 to telnet port on 2483the guest, use the following: 2484 2485@example 2486# on the host 2487@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2488telnet localhost 5555 2489@end example 2490 2491Then when you use on the host @code{telnet localhost 5555}, you 2492connect to the guest telnet server. 2493 2494@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2495@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2496Forward guest TCP connections to the IP address @var{server} on port @var{port} 2497to the character device @var{dev} or to a program executed by @var{cmd:command} 2498which gets spawned for each connection. This option can be given multiple times. 2499 2500You can either use a chardev directly and have that one used throughout QEMU's 2501lifetime, like in the following example: 2502 2503@example 2504# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2505# the guest accesses it 2506@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2507@end example 2508 2509Or you can execute a command on every TCP connection established by the guest, 2510so that QEMU behaves similar to an inetd process for that virtual server: 2511 2512@example 2513# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2514# and connect the TCP stream to its stdin/stdout 2515@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2516@end example 2517 2518@end table 2519 2520@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2521Configure a host TAP network backend with ID @var{id}. 2522 2523Use the network script @var{file} to configure it and the network script 2524@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2525automatically provides one. The default network configure script is 2526@file{/etc/qemu-ifup} and the default network deconfigure script is 2527@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2528to disable script execution. 2529 2530If running QEMU as an unprivileged user, use the network helper 2531@var{helper} to configure the TAP interface and attach it to the bridge. 2532The default network helper executable is @file{/path/to/qemu-bridge-helper} 2533and the default bridge device is @file{br0}. 2534 2535@option{fd}=@var{h} can be used to specify the handle of an already 2536opened host TAP interface. 2537 2538Examples: 2539 2540@example 2541#launch a QEMU instance with the default network script 2542@value{qemu_system} linux.img -nic tap 2543@end example 2544 2545@example 2546#launch a QEMU instance with two NICs, each one connected 2547#to a TAP device 2548@value{qemu_system} linux.img \ 2549 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2550 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2551@end example 2552 2553@example 2554#launch a QEMU instance with the default network helper to 2555#connect a TAP device to bridge br0 2556@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2557 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2558@end example 2559 2560@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2561Connect a host TAP network interface to a host bridge device. 2562 2563Use the network helper @var{helper} to configure the TAP interface and 2564attach it to the bridge. The default network helper executable is 2565@file{/path/to/qemu-bridge-helper} and the default bridge 2566device is @file{br0}. 2567 2568Examples: 2569 2570@example 2571#launch a QEMU instance with the default network helper to 2572#connect a TAP device to bridge br0 2573@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2574@end example 2575 2576@example 2577#launch a QEMU instance with the default network helper to 2578#connect a TAP device to bridge qemubr0 2579@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2580@end example 2581 2582@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2583 2584This host network backend can be used to connect the guest's network to 2585another QEMU virtual machine using a TCP socket connection. If @option{listen} 2586is specified, QEMU waits for incoming connections on @var{port} 2587(@var{host} is optional). @option{connect} is used to connect to 2588another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2589specifies an already opened TCP socket. 2590 2591Example: 2592@example 2593# launch a first QEMU instance 2594@value{qemu_system} linux.img \ 2595 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2596 -netdev socket,id=n1,listen=:1234 2597# connect the network of this instance to the network of the first instance 2598@value{qemu_system} linux.img \ 2599 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2600 -netdev socket,id=n2,connect=127.0.0.1:1234 2601@end example 2602 2603@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2604 2605Configure a socket host network backend to share the guest's network traffic 2606with another QEMU virtual machines using a UDP multicast socket, effectively 2607making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2608NOTES: 2609@enumerate 2610@item 2611Several QEMU can be running on different hosts and share same bus (assuming 2612correct multicast setup for these hosts). 2613@item 2614mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2615@url{http://user-mode-linux.sf.net}. 2616@item 2617Use @option{fd=h} to specify an already opened UDP multicast socket. 2618@end enumerate 2619 2620Example: 2621@example 2622# launch one QEMU instance 2623@value{qemu_system} linux.img \ 2624 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2625 -netdev socket,id=n1,mcast=230.0.0.1:1234 2626# launch another QEMU instance on same "bus" 2627@value{qemu_system} linux.img \ 2628 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2629 -netdev socket,id=n2,mcast=230.0.0.1:1234 2630# launch yet another QEMU instance on same "bus" 2631@value{qemu_system} linux.img \ 2632 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2633 -netdev socket,id=n3,mcast=230.0.0.1:1234 2634@end example 2635 2636Example (User Mode Linux compat.): 2637@example 2638# launch QEMU instance (note mcast address selected is UML's default) 2639@value{qemu_system} linux.img \ 2640 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2641 -netdev socket,id=n1,mcast=239.192.168.1:1102 2642# launch UML 2643/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2644@end example 2645 2646Example (send packets from host's 1.2.3.4): 2647@example 2648@value{qemu_system} linux.img \ 2649 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2650 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2651@end example 2652 2653@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}] 2654Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2655popular protocol to transport Ethernet (and other Layer 2) data frames between 2656two systems. It is present in routers, firewalls and the Linux kernel 2657(from version 3.3 onwards). 2658 2659This transport allows a VM to communicate to another VM, router or firewall directly. 2660 2661@table @option 2662@item src=@var{srcaddr} 2663 source address (mandatory) 2664@item dst=@var{dstaddr} 2665 destination address (mandatory) 2666@item udp 2667 select udp encapsulation (default is ip). 2668@item srcport=@var{srcport} 2669 source udp port. 2670@item dstport=@var{dstport} 2671 destination udp port. 2672@item ipv6 2673 force v6, otherwise defaults to v4. 2674@item rxcookie=@var{rxcookie} 2675@itemx txcookie=@var{txcookie} 2676 Cookies are a weak form of security in the l2tpv3 specification. 2677Their function is mostly to prevent misconfiguration. By default they are 32 2678bit. 2679@item cookie64 2680 Set cookie size to 64 bit instead of the default 32 2681@item counter=off 2682 Force a 'cut-down' L2TPv3 with no counter as in 2683draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2684@item pincounter=on 2685 Work around broken counter handling in peer. This may also help on 2686networks which have packet reorder. 2687@item offset=@var{offset} 2688 Add an extra offset between header and data 2689@end table 2690 2691For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2692on the remote Linux host 1.2.3.4: 2693@example 2694# Setup tunnel on linux host using raw ip as encapsulation 2695# on 1.2.3.4 2696ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2697 encap udp udp_sport 16384 udp_dport 16384 2698ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2699 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2700ifconfig vmtunnel0 mtu 1500 2701ifconfig vmtunnel0 up 2702brctl addif br-lan vmtunnel0 2703 2704 2705# on 4.3.2.1 2706# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2707 2708@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2709 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2710 2711@end example 2712 2713@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2714Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2715listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2716and MODE @var{octalmode} to change default ownership and permissions for 2717communication port. This option is only available if QEMU has been compiled 2718with vde support enabled. 2719 2720Example: 2721@example 2722# launch vde switch 2723vde_switch -F -sock /tmp/myswitch 2724# launch QEMU instance 2725@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2726@end example 2727 2728@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2729 2730Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2731be a unix domain socket backed one. The vhost-user uses a specifically defined 2732protocol to pass vhost ioctl replacement messages to an application on the other 2733end of the socket. On non-MSIX guests, the feature can be forced with 2734@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2735be created for multiqueue vhost-user. 2736 2737Example: 2738@example 2739qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2740 -numa node,memdev=mem \ 2741 -chardev socket,id=chr0,path=/path/to/socket \ 2742 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2743 -device virtio-net-pci,netdev=net0 2744@end example 2745 2746@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2747 2748Create a hub port on the emulated hub with ID @var{hubid}. 2749 2750The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2751single netdev. Alternatively, you can also connect the hubport to another 2752netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2753 2754@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2755@findex -net 2756Legacy option to configure or create an on-board (or machine default) Network 2757Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2758the default hub), or to the netdev @var{nd}. 2759The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2760can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2761only), and a @var{name} can be assigned for use in monitor commands. 2762Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2763that the card should have; this option currently only affects virtio cards; set 2764@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2765NIC is created. QEMU can emulate several different models of network card. 2766Use @code{-net nic,model=help} for a list of available devices for your target. 2767 2768@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2769Configure a host network backend (with the options corresponding to the same 2770@option{-netdev} option) and connect it to the emulated hub 0 (the default 2771hub). Use @var{name} to specify the name of the hub port. 2772ETEXI 2773 2774STEXI 2775@end table 2776ETEXI 2777DEFHEADING() 2778 2779DEFHEADING(Character device options:) 2780 2781DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2782 "-chardev help\n" 2783 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2784 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2785 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2786 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2787 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2788 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2789 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2790 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2791 " [,logfile=PATH][,logappend=on|off]\n" 2792 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2793 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2794 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2795 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2796 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2797 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2798#ifdef _WIN32 2799 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2800 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2801#else 2802 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2803 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2804#endif 2805#ifdef CONFIG_BRLAPI 2806 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2807#endif 2808#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2809 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2810 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2811 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2812#endif 2813#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2814 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2815 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2816#endif 2817#if defined(CONFIG_SPICE) 2818 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2819 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2820#endif 2821 , QEMU_ARCH_ALL 2822) 2823 2824STEXI 2825 2826The general form of a character device option is: 2827@table @option 2828@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2829@findex -chardev 2830Backend is one of: 2831@option{null}, 2832@option{socket}, 2833@option{udp}, 2834@option{msmouse}, 2835@option{vc}, 2836@option{ringbuf}, 2837@option{file}, 2838@option{pipe}, 2839@option{console}, 2840@option{serial}, 2841@option{pty}, 2842@option{stdio}, 2843@option{braille}, 2844@option{tty}, 2845@option{parallel}, 2846@option{parport}, 2847@option{spicevmc}, 2848@option{spiceport}. 2849The specific backend will determine the applicable options. 2850 2851Use @code{-chardev help} to print all available chardev backend types. 2852 2853All devices must have an id, which can be any string up to 127 characters long. 2854It is used to uniquely identify this device in other command line directives. 2855 2856A character device may be used in multiplexing mode by multiple front-ends. 2857Specify @option{mux=on} to enable this mode. 2858A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2859backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2860If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2861create a multiplexer with your specified ID, and you can then configure multiple 2862front ends to use that chardev ID for their input/output. Up to four different 2863front ends can be connected to a single multiplexed chardev. (Without 2864multiplexing enabled, a chardev can only be used by a single front end.) 2865For instance you could use this to allow a single stdio chardev to be used by 2866two serial ports and the QEMU monitor: 2867 2868@example 2869-chardev stdio,mux=on,id=char0 \ 2870-mon chardev=char0,mode=readline \ 2871-serial chardev:char0 \ 2872-serial chardev:char0 2873@end example 2874 2875You can have more than one multiplexer in a system configuration; for instance 2876you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2877multiplexed between the QEMU monitor and a parallel port: 2878 2879@example 2880-chardev stdio,mux=on,id=char0 \ 2881-mon chardev=char0,mode=readline \ 2882-parallel chardev:char0 \ 2883-chardev tcp,...,mux=on,id=char1 \ 2884-serial chardev:char1 \ 2885-serial chardev:char1 2886@end example 2887 2888When you're using a multiplexed character device, some escape sequences are 2889interpreted in the input. @xref{mux_keys, Keys in the character backend 2890multiplexer}. 2891 2892Note that some other command line options may implicitly create multiplexed 2893character backends; for instance @option{-serial mon:stdio} creates a 2894multiplexed stdio backend connected to the serial port and the QEMU monitor, 2895and @option{-nographic} also multiplexes the console and the monitor to 2896stdio. 2897 2898There is currently no support for multiplexing in the other direction 2899(where a single QEMU front end takes input and output from multiple chardevs). 2900 2901Every backend supports the @option{logfile} option, which supplies the path 2902to a file to record all data transmitted via the backend. The @option{logappend} 2903option controls whether the log file will be truncated or appended to when 2904opened. 2905 2906@end table 2907 2908The available backends are: 2909 2910@table @option 2911@item -chardev null,id=@var{id} 2912A void device. This device will not emit any data, and will drop any data it 2913receives. The null backend does not take any options. 2914 2915@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}] 2916 2917Create a two-way stream socket, which can be either a TCP or a unix socket. A 2918unix socket will be created if @option{path} is specified. Behaviour is 2919undefined if TCP options are specified for a unix socket. 2920 2921@option{server} specifies that the socket shall be a listening socket. 2922 2923@option{nowait} specifies that QEMU should not block waiting for a client to 2924connect to a listening socket. 2925 2926@option{telnet} specifies that traffic on the socket should interpret telnet 2927escape sequences. 2928 2929@option{websocket} specifies that the socket uses WebSocket protocol for 2930communication. 2931 2932@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2933the remote end goes away. qemu will delay this many seconds and then attempt 2934to reconnect. Zero disables reconnecting, and is the default. 2935 2936@option{tls-creds} requests enablement of the TLS protocol for encryption, 2937and specifies the id of the TLS credentials to use for the handshake. The 2938credentials must be previously created with the @option{-object tls-creds} 2939argument. 2940 2941@option{tls-auth} provides the ID of the QAuthZ authorization object against 2942which the client's x509 distinguished name will be validated. This object is 2943only resolved at time of use, so can be deleted and recreated on the fly 2944while the chardev server is active. If missing, it will default to denying 2945access. 2946 2947TCP and unix socket options are given below: 2948 2949@table @option 2950 2951@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2952 2953@option{host} for a listening socket specifies the local address to be bound. 2954For a connecting socket species the remote host to connect to. @option{host} is 2955optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2956 2957@option{port} for a listening socket specifies the local port to be bound. For a 2958connecting socket specifies the port on the remote host to connect to. 2959@option{port} can be given as either a port number or a service name. 2960@option{port} is required. 2961 2962@option{to} is only relevant to listening sockets. If it is specified, and 2963@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2964to and including @option{to} until it succeeds. @option{to} must be specified 2965as a port number. 2966 2967@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2968If neither is specified the socket may use either protocol. 2969 2970@option{nodelay} disables the Nagle algorithm. 2971 2972@item unix options: path=@var{path} 2973 2974@option{path} specifies the local path of the unix socket. @option{path} is 2975required. 2976 2977@end table 2978 2979@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2980 2981Sends all traffic from the guest to a remote host over UDP. 2982 2983@option{host} specifies the remote host to connect to. If not specified it 2984defaults to @code{localhost}. 2985 2986@option{port} specifies the port on the remote host to connect to. @option{port} 2987is required. 2988 2989@option{localaddr} specifies the local address to bind to. If not specified it 2990defaults to @code{0.0.0.0}. 2991 2992@option{localport} specifies the local port to bind to. If not specified any 2993available local port will be used. 2994 2995@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2996If neither is specified the device may use either protocol. 2997 2998@item -chardev msmouse,id=@var{id} 2999 3000Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 3001take any options. 3002 3003@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 3004 3005Connect to a QEMU text console. @option{vc} may optionally be given a specific 3006size. 3007 3008@option{width} and @option{height} specify the width and height respectively of 3009the console, in pixels. 3010 3011@option{cols} and @option{rows} specify that the console be sized to fit a text 3012console with the given dimensions. 3013 3014@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 3015 3016Create a ring buffer with fixed size @option{size}. 3017@var{size} must be a power of two and defaults to @code{64K}. 3018 3019@item -chardev file,id=@var{id},path=@var{path} 3020 3021Log all traffic received from the guest to a file. 3022 3023@option{path} specifies the path of the file to be opened. This file will be 3024created if it does not already exist, and overwritten if it does. @option{path} 3025is required. 3026 3027@item -chardev pipe,id=@var{id},path=@var{path} 3028 3029Create a two-way connection to the guest. The behaviour differs slightly between 3030Windows hosts and other hosts: 3031 3032On Windows, a single duplex pipe will be created at 3033@file{\\.pipe\@option{path}}. 3034 3035On other hosts, 2 pipes will be created called @file{@option{path}.in} and 3036@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 3037received by the guest. Data written by the guest can be read from 3038@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 3039be present. 3040 3041@option{path} forms part of the pipe path as described above. @option{path} is 3042required. 3043 3044@item -chardev console,id=@var{id} 3045 3046Send traffic from the guest to QEMU's standard output. @option{console} does not 3047take any options. 3048 3049@option{console} is only available on Windows hosts. 3050 3051@item -chardev serial,id=@var{id},path=@option{path} 3052 3053Send traffic from the guest to a serial device on the host. 3054 3055On Unix hosts serial will actually accept any tty device, 3056not only serial lines. 3057 3058@option{path} specifies the name of the serial device to open. 3059 3060@item -chardev pty,id=@var{id} 3061 3062Create a new pseudo-terminal on the host and connect to it. @option{pty} does 3063not take any options. 3064 3065@option{pty} is not available on Windows hosts. 3066 3067@item -chardev stdio,id=@var{id}[,signal=on|off] 3068Connect to standard input and standard output of the QEMU process. 3069 3070@option{signal} controls if signals are enabled on the terminal, that includes 3071exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3072default, use @option{signal=off} to disable it. 3073 3074@item -chardev braille,id=@var{id} 3075 3076Connect to a local BrlAPI server. @option{braille} does not take any options. 3077 3078@item -chardev tty,id=@var{id},path=@var{path} 3079 3080@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3081DragonFlyBSD hosts. It is an alias for @option{serial}. 3082 3083@option{path} specifies the path to the tty. @option{path} is required. 3084 3085@item -chardev parallel,id=@var{id},path=@var{path} 3086@itemx -chardev parport,id=@var{id},path=@var{path} 3087 3088@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3089 3090Connect to a local parallel port. 3091 3092@option{path} specifies the path to the parallel port device. @option{path} is 3093required. 3094 3095@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3096 3097@option{spicevmc} is only available when spice support is built in. 3098 3099@option{debug} debug level for spicevmc 3100 3101@option{name} name of spice channel to connect to 3102 3103Connect to a spice virtual machine channel, such as vdiport. 3104 3105@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3106 3107@option{spiceport} is only available when spice support is built in. 3108 3109@option{debug} debug level for spicevmc 3110 3111@option{name} name of spice port to connect to 3112 3113Connect to a spice port, allowing a Spice client to handle the traffic 3114identified by a name (preferably a fqdn). 3115ETEXI 3116 3117STEXI 3118@end table 3119ETEXI 3120DEFHEADING() 3121 3122#ifdef CONFIG_TPM 3123DEFHEADING(TPM device options:) 3124 3125DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3126 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3127 " use path to provide path to a character device; default is /dev/tpm0\n" 3128 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3129 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3130 "-tpmdev emulator,id=id,chardev=dev\n" 3131 " configure the TPM device using chardev backend\n", 3132 QEMU_ARCH_ALL) 3133STEXI 3134 3135The general form of a TPM device option is: 3136@table @option 3137 3138@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3139@findex -tpmdev 3140 3141The specific backend type will determine the applicable options. 3142The @code{-tpmdev} option creates the TPM backend and requires a 3143@code{-device} option that specifies the TPM frontend interface model. 3144 3145Use @code{-tpmdev help} to print all available TPM backend types. 3146 3147@end table 3148 3149The available backends are: 3150 3151@table @option 3152 3153@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3154 3155(Linux-host only) Enable access to the host's TPM using the passthrough 3156driver. 3157 3158@option{path} specifies the path to the host's TPM device, i.e., on 3159a Linux host this would be @code{/dev/tpm0}. 3160@option{path} is optional and by default @code{/dev/tpm0} is used. 3161 3162@option{cancel-path} specifies the path to the host TPM device's sysfs 3163entry allowing for cancellation of an ongoing TPM command. 3164@option{cancel-path} is optional and by default QEMU will search for the 3165sysfs entry to use. 3166 3167Some notes about using the host's TPM with the passthrough driver: 3168 3169The TPM device accessed by the passthrough driver must not be 3170used by any other application on the host. 3171 3172Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3173the VM's firmware (BIOS/UEFI) will not be able to initialize the 3174TPM again and may therefore not show a TPM-specific menu that would 3175otherwise allow the user to configure the TPM, e.g., allow the user to 3176enable/disable or activate/deactivate the TPM. 3177Further, if TPM ownership is released from within a VM then the host's TPM 3178will get disabled and deactivated. To enable and activate the 3179TPM again afterwards, the host has to be rebooted and the user is 3180required to enter the firmware's menu to enable and activate the TPM. 3181If the TPM is left disabled and/or deactivated most TPM commands will fail. 3182 3183To create a passthrough TPM use the following two options: 3184@example 3185-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3186@end example 3187Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3188@code{tpmdev=tpm0} in the device option. 3189 3190@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3191 3192(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3193chardev backend. 3194 3195@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3196 3197To create a TPM emulator backend device with chardev socket backend: 3198@example 3199 3200-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3201 3202@end example 3203 3204ETEXI 3205 3206STEXI 3207@end table 3208ETEXI 3209DEFHEADING() 3210 3211#endif 3212 3213DEFHEADING(Linux/Multiboot boot specific:) 3214STEXI 3215 3216When using these options, you can use a given Linux or Multiboot 3217kernel without installing it in the disk image. It can be useful 3218for easier testing of various kernels. 3219 3220@table @option 3221ETEXI 3222 3223DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3224 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3225STEXI 3226@item -kernel @var{bzImage} 3227@findex -kernel 3228Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3229or in multiboot format. 3230ETEXI 3231 3232DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3233 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3234STEXI 3235@item -append @var{cmdline} 3236@findex -append 3237Use @var{cmdline} as kernel command line 3238ETEXI 3239 3240DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3241 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3242STEXI 3243@item -initrd @var{file} 3244@findex -initrd 3245Use @var{file} as initial ram disk. 3246 3247@item -initrd "@var{file1} arg=foo,@var{file2}" 3248 3249This syntax is only available with multiboot. 3250 3251Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3252first module. 3253ETEXI 3254 3255DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3256 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3257STEXI 3258@item -dtb @var{file} 3259@findex -dtb 3260Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3261on boot. 3262ETEXI 3263 3264STEXI 3265@end table 3266ETEXI 3267DEFHEADING() 3268 3269DEFHEADING(Debug/Expert options:) 3270STEXI 3271@table @option 3272ETEXI 3273 3274DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3275 "-fw_cfg [name=]<name>,file=<file>\n" 3276 " add named fw_cfg entry with contents from file\n" 3277 "-fw_cfg [name=]<name>,string=<str>\n" 3278 " add named fw_cfg entry with contents from string\n", 3279 QEMU_ARCH_ALL) 3280STEXI 3281 3282@item -fw_cfg [name=]@var{name},file=@var{file} 3283@findex -fw_cfg 3284Add named fw_cfg entry with contents from file @var{file}. 3285 3286@item -fw_cfg [name=]@var{name},string=@var{str} 3287Add named fw_cfg entry with contents from string @var{str}. 3288 3289The terminating NUL character of the contents of @var{str} will not be 3290included as part of the fw_cfg item data. To insert contents with 3291embedded NUL characters, you have to use the @var{file} parameter. 3292 3293The fw_cfg entries are passed by QEMU through to the guest. 3294 3295Example: 3296@example 3297 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3298@end example 3299creates an fw_cfg entry named opt/com.mycompany/blob with contents 3300from ./my_blob.bin. 3301 3302ETEXI 3303 3304DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3305 "-serial dev redirect the serial port to char device 'dev'\n", 3306 QEMU_ARCH_ALL) 3307STEXI 3308@item -serial @var{dev} 3309@findex -serial 3310Redirect the virtual serial port to host character device 3311@var{dev}. The default device is @code{vc} in graphical mode and 3312@code{stdio} in non graphical mode. 3313 3314This option can be used several times to simulate up to 4 serial 3315ports. 3316 3317Use @code{-serial none} to disable all serial ports. 3318 3319Available character devices are: 3320@table @option 3321@item vc[:@var{W}x@var{H}] 3322Virtual console. Optionally, a width and height can be given in pixel with 3323@example 3324vc:800x600 3325@end example 3326It is also possible to specify width or height in characters: 3327@example 3328vc:80Cx24C 3329@end example 3330@item pty 3331[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3332@item none 3333No device is allocated. 3334@item null 3335void device 3336@item chardev:@var{id} 3337Use a named character device defined with the @code{-chardev} option. 3338@item /dev/XXX 3339[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3340parameters are set according to the emulated ones. 3341@item /dev/parport@var{N} 3342[Linux only, parallel port only] Use host parallel port 3343@var{N}. Currently SPP and EPP parallel port features can be used. 3344@item file:@var{filename} 3345Write output to @var{filename}. No character can be read. 3346@item stdio 3347[Unix only] standard input/output 3348@item pipe:@var{filename} 3349name pipe @var{filename} 3350@item COM@var{n} 3351[Windows only] Use host serial port @var{n} 3352@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3353This implements UDP Net Console. 3354When @var{remote_host} or @var{src_ip} are not specified 3355they default to @code{0.0.0.0}. 3356When not using a specified @var{src_port} a random port is automatically chosen. 3357 3358If you just want a simple readonly console you can use @code{netcat} or 3359@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3360@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3361will appear in the netconsole session. 3362 3363If you plan to send characters back via netconsole or you want to stop 3364and start QEMU a lot of times, you should have QEMU use the same 3365source port each time by using something like @code{-serial 3366udp::4555@@:4556} to QEMU. Another approach is to use a patched 3367version of netcat which can listen to a TCP port and send and receive 3368characters via udp. If you have a patched version of netcat which 3369activates telnet remote echo and single char transfer, then you can 3370use the following options to set up a netcat redirector to allow 3371telnet on port 5555 to access the QEMU port. 3372@table @code 3373@item QEMU Options: 3374-serial udp::4555@@:4556 3375@item netcat options: 3376-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3377@item telnet options: 3378localhost 5555 3379@end table 3380 3381@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3382The TCP Net Console has two modes of operation. It can send the serial 3383I/O to a location or wait for a connection from a location. By default 3384the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3385the @var{server} option QEMU will wait for a client socket application 3386to connect to the port before continuing, unless the @code{nowait} 3387option was specified. The @code{nodelay} option disables the Nagle buffering 3388algorithm. The @code{reconnect} option only applies if @var{noserver} is 3389set, if the connection goes down it will attempt to reconnect at the 3390given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3391one TCP connection at a time is accepted. You can use @code{telnet} to 3392connect to the corresponding character device. 3393@table @code 3394@item Example to send tcp console to 192.168.0.2 port 4444 3395-serial tcp:192.168.0.2:4444 3396@item Example to listen and wait on port 4444 for connection 3397-serial tcp::4444,server 3398@item Example to not wait and listen on ip 192.168.0.100 port 4444 3399-serial tcp:192.168.0.100:4444,server,nowait 3400@end table 3401 3402@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3403The telnet protocol is used instead of raw tcp sockets. The options 3404work the same as if you had specified @code{-serial tcp}. The 3405difference is that the port acts like a telnet server or client using 3406telnet option negotiation. This will also allow you to send the 3407MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3408sequence. Typically in unix telnet you do it with Control-] and then 3409type "send break" followed by pressing the enter key. 3410 3411@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3412The WebSocket protocol is used instead of raw tcp socket. The port acts as 3413a WebSocket server. Client mode is not supported. 3414 3415@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3416A unix domain socket is used instead of a tcp socket. The option works the 3417same as if you had specified @code{-serial tcp} except the unix domain socket 3418@var{path} is used for connections. 3419 3420@item mon:@var{dev_string} 3421This is a special option to allow the monitor to be multiplexed onto 3422another serial port. The monitor is accessed with key sequence of 3423@key{Control-a} and then pressing @key{c}. 3424@var{dev_string} should be any one of the serial devices specified 3425above. An example to multiplex the monitor onto a telnet server 3426listening on port 4444 would be: 3427@table @code 3428@item -serial mon:telnet::4444,server,nowait 3429@end table 3430When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3431QEMU any more but will be passed to the guest instead. 3432 3433@item braille 3434Braille device. This will use BrlAPI to display the braille output on a real 3435or fake device. 3436 3437@item msmouse 3438Three button serial mouse. Configure the guest to use Microsoft protocol. 3439@end table 3440ETEXI 3441 3442DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3443 "-parallel dev redirect the parallel port to char device 'dev'\n", 3444 QEMU_ARCH_ALL) 3445STEXI 3446@item -parallel @var{dev} 3447@findex -parallel 3448Redirect the virtual parallel port to host device @var{dev} (same 3449devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3450be used to use hardware devices connected on the corresponding host 3451parallel port. 3452 3453This option can be used several times to simulate up to 3 parallel 3454ports. 3455 3456Use @code{-parallel none} to disable all parallel ports. 3457ETEXI 3458 3459DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3460 "-monitor dev redirect the monitor to char device 'dev'\n", 3461 QEMU_ARCH_ALL) 3462STEXI 3463@item -monitor @var{dev} 3464@findex -monitor 3465Redirect the monitor to host device @var{dev} (same devices as the 3466serial port). 3467The default device is @code{vc} in graphical mode and @code{stdio} in 3468non graphical mode. 3469Use @code{-monitor none} to disable the default monitor. 3470ETEXI 3471DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3472 "-qmp dev like -monitor but opens in 'control' mode\n", 3473 QEMU_ARCH_ALL) 3474STEXI 3475@item -qmp @var{dev} 3476@findex -qmp 3477Like -monitor but opens in 'control' mode. 3478ETEXI 3479DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3480 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3481 QEMU_ARCH_ALL) 3482STEXI 3483@item -qmp-pretty @var{dev} 3484@findex -qmp-pretty 3485Like -qmp but uses pretty JSON formatting. 3486ETEXI 3487 3488DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3489 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3490STEXI 3491@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3492@findex -mon 3493Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3494easing human reading and debugging. 3495ETEXI 3496 3497DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3498 "-debugcon dev redirect the debug console to char device 'dev'\n", 3499 QEMU_ARCH_ALL) 3500STEXI 3501@item -debugcon @var{dev} 3502@findex -debugcon 3503Redirect the debug console to host device @var{dev} (same devices as the 3504serial port). The debug console is an I/O port which is typically port 35050xe9; writing to that I/O port sends output to this device. 3506The default device is @code{vc} in graphical mode and @code{stdio} in 3507non graphical mode. 3508ETEXI 3509 3510DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3511 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3512STEXI 3513@item -pidfile @var{file} 3514@findex -pidfile 3515Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3516from a script. 3517ETEXI 3518 3519DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3520 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3521STEXI 3522@item -singlestep 3523@findex -singlestep 3524Run the emulation in single step mode. 3525ETEXI 3526 3527DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3528 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3529 QEMU_ARCH_ALL) 3530STEXI 3531@item --preconfig 3532@findex --preconfig 3533Pause QEMU for interactive configuration before the machine is created, 3534which allows querying and configuring properties that will affect 3535machine initialization. Use QMP command 'x-exit-preconfig' to exit 3536the preconfig state and move to the next state (i.e. run guest if -S 3537isn't used or pause the second time if -S is used). This option is 3538experimental. 3539ETEXI 3540 3541DEF("S", 0, QEMU_OPTION_S, \ 3542 "-S freeze CPU at startup (use 'c' to start execution)\n", 3543 QEMU_ARCH_ALL) 3544STEXI 3545@item -S 3546@findex -S 3547Do not start CPU at startup (you must type 'c' in the monitor). 3548ETEXI 3549 3550DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3551 "-realtime [mlock=on|off]\n" 3552 " run qemu with realtime features\n" 3553 " mlock=on|off controls mlock support (default: on)\n", 3554 QEMU_ARCH_ALL) 3555STEXI 3556@item -realtime mlock=on|off 3557@findex -realtime 3558Run qemu with realtime features. 3559mlocking qemu and guest memory can be enabled via @option{mlock=on} 3560(enabled by default). 3561ETEXI 3562 3563DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3564 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3565 " run qemu with overcommit hints\n" 3566 " mem-lock=on|off controls memory lock support (default: off)\n" 3567 " cpu-pm=on|off controls cpu power management (default: off)\n", 3568 QEMU_ARCH_ALL) 3569STEXI 3570@item -overcommit mem-lock=on|off 3571@item -overcommit cpu-pm=on|off 3572@findex -overcommit 3573Run qemu with hints about host resource overcommit. The default is 3574to assume that host overcommits all resources. 3575 3576Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3577by default). This works when host memory is not overcommitted and reduces the 3578worst-case latency for guest. This is equivalent to @option{realtime}. 3579 3580Guest ability to manage power state of host cpus (increasing latency for other 3581processes on the same host cpu, but decreasing latency for guest) can be 3582enabled via @option{cpu-pm=on} (disabled by default). This works best when 3583host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3584utilization will be incorrect, not taking into account guest idle time. 3585ETEXI 3586 3587DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3588 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3589STEXI 3590@item -gdb @var{dev} 3591@findex -gdb 3592Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3593connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3594stdio are reasonable use case. The latter is allowing to start QEMU from 3595within gdb and establish the connection via a pipe: 3596@example 3597(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3598@end example 3599ETEXI 3600 3601DEF("s", 0, QEMU_OPTION_s, \ 3602 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3603 QEMU_ARCH_ALL) 3604STEXI 3605@item -s 3606@findex -s 3607Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3608(@pxref{gdb_usage}). 3609ETEXI 3610 3611DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3612 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3613 QEMU_ARCH_ALL) 3614STEXI 3615@item -d @var{item1}[,...] 3616@findex -d 3617Enable logging of specified items. Use '-d help' for a list of log items. 3618ETEXI 3619 3620DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3621 "-D logfile output log to logfile (default stderr)\n", 3622 QEMU_ARCH_ALL) 3623STEXI 3624@item -D @var{logfile} 3625@findex -D 3626Output log in @var{logfile} instead of to stderr 3627ETEXI 3628 3629DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3630 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3631 QEMU_ARCH_ALL) 3632STEXI 3633@item -dfilter @var{range1}[,...] 3634@findex -dfilter 3635Filter debug output to that relevant to a range of target addresses. The filter 3636spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3637@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3638addresses and sizes required. For example: 3639@example 3640 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3641@end example 3642Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3643the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3644block starting at 0xffffffc00005f000. 3645ETEXI 3646 3647DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3648 "-seed number seed the pseudo-random number generator\n", 3649 QEMU_ARCH_ALL) 3650STEXI 3651@item -seed @var{number} 3652@findex -seed 3653Force the guest to use a deterministic pseudo-random number generator, seeded 3654with @var{number}. This does not affect crypto routines within the host. 3655ETEXI 3656 3657DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3658 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3659 QEMU_ARCH_ALL) 3660STEXI 3661@item -L @var{path} 3662@findex -L 3663Set the directory for the BIOS, VGA BIOS and keymaps. 3664 3665To list all the data directories, use @code{-L help}. 3666ETEXI 3667 3668DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3669 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3670STEXI 3671@item -bios @var{file} 3672@findex -bios 3673Set the filename for the BIOS. 3674ETEXI 3675 3676DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3677 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3678STEXI 3679@item -enable-kvm 3680@findex -enable-kvm 3681Enable KVM full virtualization support. This option is only available 3682if KVM support is enabled when compiling. 3683ETEXI 3684 3685DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3686 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3687DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3688 "-xen-attach attach to existing xen domain\n" 3689 " libxl will use this when starting QEMU\n", 3690 QEMU_ARCH_ALL) 3691DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3692 "-xen-domid-restrict restrict set of available xen operations\n" 3693 " to specified domain id. (Does not affect\n" 3694 " xenpv machine type).\n", 3695 QEMU_ARCH_ALL) 3696STEXI 3697@item -xen-domid @var{id} 3698@findex -xen-domid 3699Specify xen guest domain @var{id} (XEN only). 3700@item -xen-attach 3701@findex -xen-attach 3702Attach to existing xen domain. 3703libxl will use this when starting QEMU (XEN only). 3704@findex -xen-domid-restrict 3705Restrict set of available xen operations to specified domain id (XEN only). 3706ETEXI 3707 3708DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3709 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3710STEXI 3711@item -no-reboot 3712@findex -no-reboot 3713Exit instead of rebooting. 3714ETEXI 3715 3716DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3717 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3718STEXI 3719@item -no-shutdown 3720@findex -no-shutdown 3721Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3722This allows for instance switching to monitor to commit changes to the 3723disk image. 3724ETEXI 3725 3726DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3727 "-loadvm [tag|id]\n" \ 3728 " start right away with a saved state (loadvm in monitor)\n", 3729 QEMU_ARCH_ALL) 3730STEXI 3731@item -loadvm @var{file} 3732@findex -loadvm 3733Start right away with a saved state (@code{loadvm} in monitor) 3734ETEXI 3735 3736#ifndef _WIN32 3737DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3738 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3739#endif 3740STEXI 3741@item -daemonize 3742@findex -daemonize 3743Daemonize the QEMU process after initialization. QEMU will not detach from 3744standard IO until it is ready to receive connections on any of its devices. 3745This option is a useful way for external programs to launch QEMU without having 3746to cope with initialization race conditions. 3747ETEXI 3748 3749DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3750 "-option-rom rom load a file, rom, into the option ROM space\n", 3751 QEMU_ARCH_ALL) 3752STEXI 3753@item -option-rom @var{file} 3754@findex -option-rom 3755Load the contents of @var{file} as an option ROM. 3756This option is useful to load things like EtherBoot. 3757ETEXI 3758 3759DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3760 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3761 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3762 QEMU_ARCH_ALL) 3763 3764STEXI 3765 3766@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3767@findex -rtc 3768Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3769UTC or local time, respectively. @code{localtime} is required for correct date in 3770MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3771format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3772 3773By default the RTC is driven by the host system time. This allows using of the 3774RTC as accurate reference clock inside the guest, specifically if the host 3775time is smoothly following an accurate external reference clock, e.g. via NTP. 3776If you want to isolate the guest time from the host, you can set @option{clock} 3777to @code{rt} instead, which provides a host monotonic clock if host support it. 3778To even prevent the RTC from progressing during suspension, you can set @option{clock} 3779to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3780icount mode in order to preserve determinism; however, note that in icount mode 3781the speed of the virtual clock is variable and can in general differ from the 3782host clock. 3783 3784Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3785specifically with Windows' ACPI HAL. This option will try to figure out how 3786many timer interrupts were not processed by the Windows guest and will 3787re-inject them. 3788ETEXI 3789 3790DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3791 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3792 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3793 " instruction, enable aligning the host and virtual clocks\n" \ 3794 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3795STEXI 3796@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3797@findex -icount 3798Enable virtual instruction counter. The virtual cpu will execute one 3799instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3800then the virtual cpu speed will be automatically adjusted to keep virtual 3801time within a few seconds of real time. 3802 3803When the virtual cpu is sleeping, the virtual time will advance at default 3804speed unless @option{sleep=on|off} is specified. 3805With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3806instantly whenever the virtual cpu goes to sleep mode and will not advance 3807if no timer is enabled. This behavior give deterministic execution times from 3808the guest point of view. 3809 3810Note that while this option can give deterministic behavior, it does not 3811provide cycle accurate emulation. Modern CPUs contain superscalar out of 3812order cores with complex cache hierarchies. The number of instructions 3813executed often has little or no correlation with actual performance. 3814 3815@option{align=on} will activate the delay algorithm which will try 3816to synchronise the host clock and the virtual clock. The goal is to 3817have a guest running at the real frequency imposed by the shift option. 3818Whenever the guest clock is behind the host clock and if 3819@option{align=on} is specified then we print a message to the user 3820to inform about the delay. 3821Currently this option does not work when @option{shift} is @code{auto}. 3822Note: The sync algorithm will work for those shift values for which 3823the guest clock runs ahead of the host clock. Typically this happens 3824when the shift value is high (how high depends on the host machine). 3825 3826When @option{rr} option is specified deterministic record/replay is enabled. 3827Replay log is written into @var{filename} file in record mode and 3828read from this file in replay mode. 3829 3830Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3831at the start of execution recording. In replay mode this option is used 3832to load the initial VM state. 3833ETEXI 3834 3835DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3836 "-watchdog model\n" \ 3837 " enable virtual hardware watchdog [default=none]\n", 3838 QEMU_ARCH_ALL) 3839STEXI 3840@item -watchdog @var{model} 3841@findex -watchdog 3842Create a virtual hardware watchdog device. Once enabled (by a guest 3843action), the watchdog must be periodically polled by an agent inside 3844the guest or else the guest will be restarted. Choose a model for 3845which your guest has drivers. 3846 3847The @var{model} is the model of hardware watchdog to emulate. Use 3848@code{-watchdog help} to list available hardware models. Only one 3849watchdog can be enabled for a guest. 3850 3851The following models may be available: 3852@table @option 3853@item ib700 3854iBASE 700 is a very simple ISA watchdog with a single timer. 3855@item i6300esb 3856Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3857dual-timer watchdog. 3858@item diag288 3859A virtual watchdog for s390x backed by the diagnose 288 hypercall 3860(currently KVM only). 3861@end table 3862ETEXI 3863 3864DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3865 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3866 " action when watchdog fires [default=reset]\n", 3867 QEMU_ARCH_ALL) 3868STEXI 3869@item -watchdog-action @var{action} 3870@findex -watchdog-action 3871 3872The @var{action} controls what QEMU will do when the watchdog timer 3873expires. 3874The default is 3875@code{reset} (forcefully reset the guest). 3876Other possible actions are: 3877@code{shutdown} (attempt to gracefully shutdown the guest), 3878@code{poweroff} (forcefully poweroff the guest), 3879@code{inject-nmi} (inject a NMI into the guest), 3880@code{pause} (pause the guest), 3881@code{debug} (print a debug message and continue), or 3882@code{none} (do nothing). 3883 3884Note that the @code{shutdown} action requires that the guest responds 3885to ACPI signals, which it may not be able to do in the sort of 3886situations where the watchdog would have expired, and thus 3887@code{-watchdog-action shutdown} is not recommended for production use. 3888 3889Examples: 3890 3891@table @code 3892@item -watchdog i6300esb -watchdog-action pause 3893@itemx -watchdog ib700 3894@end table 3895ETEXI 3896 3897DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3898 "-echr chr set terminal escape character instead of ctrl-a\n", 3899 QEMU_ARCH_ALL) 3900STEXI 3901 3902@item -echr @var{numeric_ascii_value} 3903@findex -echr 3904Change the escape character used for switching to the monitor when using 3905monitor and serial sharing. The default is @code{0x01} when using the 3906@code{-nographic} option. @code{0x01} is equal to pressing 3907@code{Control-a}. You can select a different character from the ascii 3908control keys where 1 through 26 map to Control-a through Control-z. For 3909instance you could use the either of the following to change the escape 3910character to Control-t. 3911@table @code 3912@item -echr 0x14 3913@itemx -echr 20 3914@end table 3915ETEXI 3916 3917DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3918 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3919STEXI 3920@item -show-cursor 3921@findex -show-cursor 3922Show cursor. 3923ETEXI 3924 3925DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3926 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3927STEXI 3928@item -tb-size @var{n} 3929@findex -tb-size 3930Set TCG translation block cache size. Deprecated, use @samp{-accel tcg,tb-size=@var{n}} 3931instead. 3932ETEXI 3933 3934DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3935 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3936 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3937 "-incoming unix:socketpath\n" \ 3938 " prepare for incoming migration, listen on\n" \ 3939 " specified protocol and socket address\n" \ 3940 "-incoming fd:fd\n" \ 3941 "-incoming exec:cmdline\n" \ 3942 " accept incoming migration on given file descriptor\n" \ 3943 " or from given external command\n" \ 3944 "-incoming defer\n" \ 3945 " wait for the URI to be specified via migrate_incoming\n", 3946 QEMU_ARCH_ALL) 3947STEXI 3948@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3949@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3950@findex -incoming 3951Prepare for incoming migration, listen on a given tcp port. 3952 3953@item -incoming unix:@var{socketpath} 3954Prepare for incoming migration, listen on a given unix socket. 3955 3956@item -incoming fd:@var{fd} 3957Accept incoming migration from a given filedescriptor. 3958 3959@item -incoming exec:@var{cmdline} 3960Accept incoming migration as an output from specified external command. 3961 3962@item -incoming defer 3963Wait for the URI to be specified via migrate_incoming. The monitor can 3964be used to change settings (such as migration parameters) prior to issuing 3965the migrate_incoming to allow the migration to begin. 3966ETEXI 3967 3968DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3969 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3970STEXI 3971@item -only-migratable 3972@findex -only-migratable 3973Only allow migratable devices. Devices will not be allowed to enter an 3974unmigratable state. 3975ETEXI 3976 3977DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3978 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3979STEXI 3980@item -nodefaults 3981@findex -nodefaults 3982Don't create default devices. Normally, QEMU sets the default devices like serial 3983port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3984CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3985default devices. 3986ETEXI 3987 3988#ifndef _WIN32 3989DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3990 "-chroot dir chroot to dir just before starting the VM\n", 3991 QEMU_ARCH_ALL) 3992#endif 3993STEXI 3994@item -chroot @var{dir} 3995@findex -chroot 3996Immediately before starting guest execution, chroot to the specified 3997directory. Especially useful in combination with -runas. 3998ETEXI 3999 4000#ifndef _WIN32 4001DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4002 "-runas user change to user id user just before starting the VM\n" \ 4003 " user can be numeric uid:gid instead\n", 4004 QEMU_ARCH_ALL) 4005#endif 4006STEXI 4007@item -runas @var{user} 4008@findex -runas 4009Immediately before starting guest execution, drop root privileges, switching 4010to the specified user. 4011ETEXI 4012 4013DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4014 "-prom-env variable=value\n" 4015 " set OpenBIOS nvram variables\n", 4016 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4017STEXI 4018@item -prom-env @var{variable}=@var{value} 4019@findex -prom-env 4020Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4021ETEXI 4022DEF("semihosting", 0, QEMU_OPTION_semihosting, 4023 "-semihosting semihosting mode\n", 4024 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4025 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4026STEXI 4027@item -semihosting 4028@findex -semihosting 4029Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4030ETEXI 4031DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4032 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4033 " semihosting configuration\n", 4034QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4035QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4036STEXI 4037@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4038@findex -semihosting-config 4039Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4040@table @option 4041@item target=@code{native|gdb|auto} 4042Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4043or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4044during debug sessions and @code{native} otherwise. 4045@item chardev=@var{str1} 4046Send the output to a chardev backend output for native or auto output when not in gdb 4047@item arg=@var{str1},arg=@var{str2},... 4048Allows the user to pass input arguments, and can be used multiple times to build 4049up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4050command line is still supported for backward compatibility. If both the 4051@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4052specified, the former is passed to semihosting as it always takes precedence. 4053@end table 4054ETEXI 4055DEF("old-param", 0, QEMU_OPTION_old_param, 4056 "-old-param old param mode\n", QEMU_ARCH_ARM) 4057STEXI 4058@item -old-param 4059@findex -old-param (ARM) 4060Old param mode (ARM only). 4061ETEXI 4062 4063DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4064 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4065 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4066 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4067 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4068 " by the kernel, but typically no longer used by modern\n" \ 4069 " C library implementations.\n" \ 4070 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4071 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4072 " The value 'children' will deny set*uid|gid system calls for\n" \ 4073 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4074 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4075 " blacklisting *fork and execve\n" \ 4076 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4077 QEMU_ARCH_ALL) 4078STEXI 4079@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4080@findex -sandbox 4081Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4082disable it. The default is 'off'. 4083@table @option 4084@item obsolete=@var{string} 4085Enable Obsolete system calls 4086@item elevateprivileges=@var{string} 4087Disable set*uid|gid system calls 4088@item spawn=@var{string} 4089Disable *fork and execve 4090@item resourcecontrol=@var{string} 4091Disable process affinity and schedular priority 4092@end table 4093ETEXI 4094 4095DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4096 "-readconfig <file>\n", QEMU_ARCH_ALL) 4097STEXI 4098@item -readconfig @var{file} 4099@findex -readconfig 4100Read device configuration from @var{file}. This approach is useful when you want to spawn 4101QEMU process with many command line options but you don't want to exceed the command line 4102character limit. 4103ETEXI 4104DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4105 "-writeconfig <file>\n" 4106 " read/write config file\n", QEMU_ARCH_ALL) 4107STEXI 4108@item -writeconfig @var{file} 4109@findex -writeconfig 4110Write device configuration to @var{file}. The @var{file} can be either filename to save 4111command line and device configuration into file or dash @code{-}) character to print the 4112output to stdout. This can be later used as input file for @code{-readconfig} option. 4113ETEXI 4114 4115DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4116 "-no-user-config\n" 4117 " do not load default user-provided config files at startup\n", 4118 QEMU_ARCH_ALL) 4119STEXI 4120@item -no-user-config 4121@findex -no-user-config 4122The @code{-no-user-config} option makes QEMU not load any of the user-provided 4123config files on @var{sysconfdir}. 4124ETEXI 4125 4126DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4127 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4128 " specify tracing options\n", 4129 QEMU_ARCH_ALL) 4130STEXI 4131HXCOMM This line is not accurate, as some sub-options are backend-specific but 4132HXCOMM HX does not support conditional compilation of text. 4133@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4134@findex -trace 4135@include qemu-option-trace.texi 4136ETEXI 4137DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4138 "-plugin [file=]<file>[,arg=<string>]\n" 4139 " load a plugin\n", 4140 QEMU_ARCH_ALL) 4141STEXI 4142@item -plugin file=@var{file}[,arg=@var{string}] 4143@findex -plugin 4144 4145Load a plugin. 4146 4147@table @option 4148@item file=@var{file} 4149Load the given plugin from a shared library file. 4150@item arg=@var{string} 4151Argument string passed to the plugin. (Can be given multiple times.) 4152@end table 4153ETEXI 4154 4155HXCOMM Internal use 4156DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4157DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4158 4159#ifdef __linux__ 4160DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4161 "-enable-fips enable FIPS 140-2 compliance\n", 4162 QEMU_ARCH_ALL) 4163#endif 4164STEXI 4165@item -enable-fips 4166@findex -enable-fips 4167Enable FIPS 140-2 compliance mode. 4168ETEXI 4169 4170HXCOMM Deprecated by -accel tcg 4171DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4172 4173DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4174 "-msg timestamp[=on|off]\n" 4175 " change the format of messages\n" 4176 " on|off controls leading timestamps (default:on)\n", 4177 QEMU_ARCH_ALL) 4178STEXI 4179@item -msg timestamp[=on|off] 4180@findex -msg 4181prepend a timestamp to each log message.(default:on) 4182ETEXI 4183 4184DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4185 "-dump-vmstate <file>\n" 4186 " Output vmstate information in JSON format to file.\n" 4187 " Use the scripts/vmstate-static-checker.py file to\n" 4188 " check for possible regressions in migration code\n" 4189 " by comparing two such vmstate dumps.\n", 4190 QEMU_ARCH_ALL) 4191STEXI 4192@item -dump-vmstate @var{file} 4193@findex -dump-vmstate 4194Dump json-encoded vmstate information for current machine type to file 4195in @var{file} 4196ETEXI 4197 4198DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4199 "-enable-sync-profile\n" 4200 " enable synchronization profiling\n", 4201 QEMU_ARCH_ALL) 4202STEXI 4203@item -enable-sync-profile 4204@findex -enable-sync-profile 4205Enable synchronization profiling. 4206ETEXI 4207 4208STEXI 4209@end table 4210ETEXI 4211DEFHEADING() 4212 4213DEFHEADING(Generic object creation:) 4214STEXI 4215@table @option 4216ETEXI 4217 4218DEF("object", HAS_ARG, QEMU_OPTION_object, 4219 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4220 " create a new object of type TYPENAME setting properties\n" 4221 " in the order they are specified. Note that the 'id'\n" 4222 " property must be set. These objects are placed in the\n" 4223 " '/objects' path.\n", 4224 QEMU_ARCH_ALL) 4225STEXI 4226@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4227@findex -object 4228Create a new object of type @var{typename} setting properties 4229in the order they are specified. Note that the 'id' 4230property must be set. These objects are placed in the 4231'/objects' path. 4232 4233@table @option 4234 4235@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} 4236 4237Creates a memory file backend object, which can be used to back 4238the guest RAM with huge pages. 4239 4240The @option{id} parameter is a unique ID that will be used to reference this 4241memory region when configuring the @option{-numa} argument. 4242 4243The @option{size} option provides the size of the memory region, and accepts 4244common suffixes, eg @option{500M}. 4245 4246The @option{mem-path} provides the path to either a shared memory or huge page 4247filesystem mount. 4248 4249The @option{share} boolean option determines whether the memory 4250region is marked as private to QEMU, or shared. The latter allows 4251a co-operating external process to access the QEMU memory region. 4252 4253The @option{share} is also required for pvrdma devices due to 4254limitations in the RDMA API provided by Linux. 4255 4256Setting share=on might affect the ability to configure NUMA 4257bindings for the memory backend under some circumstances, see 4258Documentation/vm/numa_memory_policy.txt on the Linux kernel 4259source tree for additional details. 4260 4261Setting the @option{discard-data} boolean option to @var{on} 4262indicates that file contents can be destroyed when QEMU exits, 4263to avoid unnecessarily flushing data to the backing file. Note 4264that @option{discard-data} is only an optimization, and QEMU 4265might not discard file contents if it aborts unexpectedly or is 4266terminated using SIGKILL. 4267 4268The @option{merge} boolean option enables memory merge, also known as 4269MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4270memory deduplication. 4271 4272Setting the @option{dump} boolean option to @var{off} excludes the memory from 4273core dumps. This feature is also known as MADV_DONTDUMP. 4274 4275The @option{prealloc} boolean option enables memory preallocation. 4276 4277The @option{host-nodes} option binds the memory range to a list of NUMA host 4278nodes. 4279 4280The @option{policy} option sets the NUMA policy to one of the following values: 4281 4282@table @option 4283@item @var{default} 4284default host policy 4285 4286@item @var{preferred} 4287prefer the given host node list for allocation 4288 4289@item @var{bind} 4290restrict memory allocation to the given host node list 4291 4292@item @var{interleave} 4293interleave memory allocations across the given host node list 4294@end table 4295 4296The @option{align} option specifies the base address alignment when 4297QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4298@option{2M}. Some backend store specified by @option{mem-path} 4299requires an alignment different than the default one used by QEMU, eg 4300the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4301such cases, users can specify the required alignment via this option. 4302 4303The @option{pmem} option specifies whether the backing file specified 4304by @option{mem-path} is in host persistent memory that can be accessed 4305using the SNIA NVM programming model (e.g. Intel NVDIMM). 4306If @option{pmem} is set to 'on', QEMU will take necessary operations to 4307guarantee the persistence of its own writes to @option{mem-path} 4308(e.g. in vNVDIMM label emulation and live migration). 4309Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4310file metadata is in sync for @option{mem-path} in case of host crash 4311or a power failure. MAP_SYNC requires support from both the host kernel 4312(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4313with DAX option. 4314 4315@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} 4316 4317Creates a memory backend object, which can be used to back the guest RAM. 4318Memory backend objects offer more control than the @option{-m} option that is 4319traditionally used to define guest RAM. Please refer to 4320@option{memory-backend-file} for a description of the options. 4321 4322@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} 4323 4324Creates an anonymous memory file backend object, which allows QEMU to 4325share the memory with an external process (e.g. when using 4326vhost-user). The memory is allocated with memfd and optional 4327sealing. (Linux only) 4328 4329The @option{seal} option creates a sealed-file, that will block 4330further resizing the memory ('on' by default). 4331 4332The @option{hugetlb} option specify the file to be created resides in 4333the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4334the @option{hugetlb} option, the @option{hugetlbsize} option specify 4335the hugetlb page size on systems that support multiple hugetlb page 4336sizes (it must be a power of 2 value supported by the system). 4337 4338In some versions of Linux, the @option{hugetlb} option is incompatible 4339with the @option{seal} option (requires at least Linux 4.16). 4340 4341Please refer to @option{memory-backend-file} for a description of the 4342other options. 4343 4344The @option{share} boolean option is @var{on} by default with memfd. 4345 4346@item -object rng-builtin,id=@var{id} 4347 4348Creates a random number generator backend which obtains entropy from 4349QEMU builtin functions. The @option{id} parameter is a unique ID that 4350will be used to reference this entropy backend from the @option{virtio-rng} 4351device. By default, the @option{virtio-rng} device uses this RNG backend. 4352 4353@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4354 4355Creates a random number generator backend which obtains entropy from 4356a device on the host. The @option{id} parameter is a unique ID that 4357will be used to reference this entropy backend from the @option{virtio-rng} 4358device. The @option{filename} parameter specifies which file to obtain 4359entropy from and if omitted defaults to @option{/dev/urandom}. 4360 4361@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4362 4363Creates a random number generator backend which obtains entropy from 4364an external daemon running on the host. The @option{id} parameter is 4365a unique ID that will be used to reference this entropy backend from 4366the @option{virtio-rng} device. The @option{chardev} parameter is 4367the unique ID of a character device backend that provides the connection 4368to the RNG daemon. 4369 4370@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4371 4372Creates a TLS anonymous credentials object, which can be used to provide 4373TLS support on network backends. The @option{id} parameter is a unique 4374ID which network backends will use to access the credentials. The 4375@option{endpoint} is either @option{server} or @option{client} depending 4376on whether the QEMU network backend that uses the credentials will be 4377acting as a client or as a server. If @option{verify-peer} is enabled 4378(the default) then once the handshake is completed, the peer credentials 4379will be verified, though this is a no-op for anonymous credentials. 4380 4381The @var{dir} parameter tells QEMU where to find the credential 4382files. For server endpoints, this directory may contain a file 4383@var{dh-params.pem} providing diffie-hellman parameters to use 4384for the TLS server. If the file is missing, QEMU will generate 4385a set of DH parameters at startup. This is a computationally 4386expensive operation that consumes random pool entropy, so it is 4387recommended that a persistent set of parameters be generated 4388upfront and saved. 4389 4390@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4391 4392Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4393TLS support on network backends. The @option{id} parameter is a unique 4394ID which network backends will use to access the credentials. The 4395@option{endpoint} is either @option{server} or @option{client} depending 4396on whether the QEMU network backend that uses the credentials will be 4397acting as a client or as a server. For clients only, @option{username} 4398is the username which will be sent to the server. If omitted 4399it defaults to ``qemu''. 4400 4401The @var{dir} parameter tells QEMU where to find the keys file. 4402It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4403pairs. This file can most easily be created using the GnuTLS 4404@code{psktool} program. 4405 4406For server endpoints, @var{dir} may also contain a file 4407@var{dh-params.pem} providing diffie-hellman parameters to use 4408for the TLS server. If the file is missing, QEMU will generate 4409a set of DH parameters at startup. This is a computationally 4410expensive operation that consumes random pool entropy, so it is 4411recommended that a persistent set of parameters be generated 4412up front and saved. 4413 4414@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} 4415 4416Creates a TLS anonymous credentials object, which can be used to provide 4417TLS support on network backends. The @option{id} parameter is a unique 4418ID which network backends will use to access the credentials. The 4419@option{endpoint} is either @option{server} or @option{client} depending 4420on whether the QEMU network backend that uses the credentials will be 4421acting as a client or as a server. If @option{verify-peer} is enabled 4422(the default) then once the handshake is completed, the peer credentials 4423will be verified. With x509 certificates, this implies that the clients 4424must be provided with valid client certificates too. 4425 4426The @var{dir} parameter tells QEMU where to find the credential 4427files. For server endpoints, this directory may contain a file 4428@var{dh-params.pem} providing diffie-hellman parameters to use 4429for the TLS server. If the file is missing, QEMU will generate 4430a set of DH parameters at startup. This is a computationally 4431expensive operation that consumes random pool entropy, so it is 4432recommended that a persistent set of parameters be generated 4433upfront and saved. 4434 4435For x509 certificate credentials the directory will contain further files 4436providing the x509 certificates. The certificates must be stored 4437in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4438@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4439@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4440 4441For the @var{server-key.pem} and @var{client-key.pem} files which 4442contain sensitive private keys, it is possible to use an encrypted 4443version by providing the @var{passwordid} parameter. This provides 4444the ID of a previously created @code{secret} object containing the 4445password for decryption. 4446 4447The @var{priority} parameter allows to override the global default 4448priority used by gnutls. This can be useful if the system administrator 4449needs to use a weaker set of crypto priorities for QEMU without 4450potentially forcing the weakness onto all applications. Or conversely 4451if one wants wants a stronger default for QEMU than for all other 4452applications, they can do this through this parameter. Its format is 4453a gnutls priority string as described at 4454@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4455 4456@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4457 4458Interval @var{t} can't be 0, this filter batches the packet delivery: all 4459packets arriving in a given interval on netdev @var{netdevid} are delayed 4460until the end of the interval. Interval is in microseconds. 4461@option{status} is optional that indicate whether the netfilter is 4462on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4463 4464queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4465 4466@option{all}: the filter is attached both to the receive and the transmit 4467 queue of the netdev (default). 4468 4469@option{rx}: the filter is attached to the receive queue of the netdev, 4470 where it will receive packets sent to the netdev. 4471 4472@option{tx}: the filter is attached to the transmit queue of the netdev, 4473 where it will receive packets sent by the netdev. 4474 4475@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4476 4477filter-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. 4478 4479@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4480 4481filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4482@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4483filter-redirector will redirect packet with vnet_hdr_len. 4484Create a filter-redirector we need to differ outdev id from indev id, id can not 4485be the same. we can just use indev or outdev, but at least one of indev or outdev 4486need to be specified. 4487 4488@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4489 4490Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4491secondary from primary to keep secondary tcp connection,and rewrite 4492tcp packet to primary from secondary make tcp packet can be handled by 4493client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4494 4495usage: 4496colo secondary: 4497-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4498-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4499-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4500 4501@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4502 4503Dump the network traffic on netdev @var{dev} to the file specified by 4504@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4505The file format is libpcap, so it can be analyzed with tools such as tcpdump 4506or Wireshark. 4507 4508@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}] 4509 4510Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4511secondary packet. If the packets are same, we will output primary 4512packet to outdev@var{chardevid}, else we will notify colo-frame 4513do checkpoint and send primary packet to outdev@var{chardevid}. 4514In order to improve efficiency, we need to put the task of comparison 4515in another thread. If it has the vnet_hdr_support flag, colo compare 4516will send/recv packet with vnet_hdr_len. 4517If you want to use Xen COLO, will need the notify_dev to notify Xen 4518colo-frame to do checkpoint. 4519 4520we must use it with the help of filter-mirror and filter-redirector. 4521 4522@example 4523 4524KVM COLO 4525 4526primary: 4527-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4528-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4529-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4530-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4531-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4532-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4533-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4534-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4535-object iothread,id=iothread1 4536-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4537-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4538-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4539-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4540 4541secondary: 4542-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4543-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4544-chardev socket,id=red0,host=3.3.3.3,port=9003 4545-chardev socket,id=red1,host=3.3.3.3,port=9004 4546-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4547-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4548 4549 4550Xen COLO 4551 4552primary: 4553-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4554-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4555-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4556-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4557-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4558-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4559-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4560-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4561-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4562-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4563-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4564-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4565-object iothread,id=iothread1 4566-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4567 4568secondary: 4569-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4570-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4571-chardev socket,id=red0,host=3.3.3.3,port=9003 4572-chardev socket,id=red1,host=3.3.3.3,port=9004 4573-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4574-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4575 4576@end example 4577 4578If you want to know the detail of above command line, you can read 4579the colo-compare git log. 4580 4581@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4582 4583Creates a cryptodev backend which executes crypto opreation from 4584the QEMU cipher APIS. The @var{id} parameter is 4585a unique ID that will be used to reference this cryptodev backend from 4586the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4587which specify the queue number of cryptodev backend, the default of 4588@var{queues} is 1. 4589 4590@example 4591 4592 # @value{qemu_system} \ 4593 [...] \ 4594 -object cryptodev-backend-builtin,id=cryptodev0 \ 4595 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4596 [...] 4597@end example 4598 4599@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4600 4601Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4602The @var{id} parameter is a unique ID that will be used to reference this 4603cryptodev backend from the @option{virtio-crypto} device. 4604The chardev should be a unix domain socket backed one. The vhost-user uses 4605a specifically defined protocol to pass vhost ioctl replacement messages 4606to an application on the other end of the socket. 4607The @var{queues} parameter is optional, which specify the queue number 4608of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4609 4610@example 4611 4612 # @value{qemu_system} \ 4613 [...] \ 4614 -chardev socket,id=chardev0,path=/path/to/socket \ 4615 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4616 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4617 [...] 4618@end example 4619 4620@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4621@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4622 4623Defines a secret to store a password, encryption key, or some other sensitive 4624data. The sensitive data can either be passed directly via the @var{data} 4625parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4626parameter is insecure unless the sensitive data is encrypted. 4627 4628The sensitive data can be provided in raw format (the default), or base64. 4629When encoded as JSON, the raw format only supports valid UTF-8 characters, 4630so base64 is recommended for sending binary data. QEMU will convert from 4631which ever format is provided to the format it needs internally. eg, an 4632RBD password can be provided in raw format, even though it will be base64 4633encoded when passed onto the RBD sever. 4634 4635For added protection, it is possible to encrypt the data associated with 4636a secret using the AES-256-CBC cipher. Use of encryption is indicated 4637by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4638parameter provides the ID of a previously defined secret that contains 4639the AES-256 decryption key. This key should be 32-bytes long and be 4640base64 encoded. The @var{iv} parameter provides the random initialization 4641vector used for encryption of this particular secret and should be a 4642base64 encrypted string of the 16-byte IV. 4643 4644The simplest (insecure) usage is to provide the secret inline 4645 4646@example 4647 4648 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4649 4650@end example 4651 4652The simplest secure usage is to provide the secret via a file 4653 4654 # printf "letmein" > mypasswd.txt 4655 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4656 4657For greater security, AES-256-CBC should be used. To illustrate usage, 4658consider the openssl command line tool which can encrypt the data. Note 4659that when encrypting, the plaintext must be padded to the cipher block 4660size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4661 4662First a master key needs to be created in base64 encoding: 4663 4664@example 4665 # openssl rand -base64 32 > key.b64 4666 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4667@end example 4668 4669Each secret to be encrypted needs to have a random initialization vector 4670generated. These do not need to be kept secret 4671 4672@example 4673 # openssl rand -base64 16 > iv.b64 4674 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4675@end example 4676 4677The secret to be defined can now be encrypted, in this case we're 4678telling openssl to base64 encode the result, but it could be left 4679as raw bytes if desired. 4680 4681@example 4682 # SECRET=$(printf "letmein" | 4683 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4684@end example 4685 4686When launching QEMU, create a master secret pointing to @code{key.b64} 4687and specify that to be used to decrypt the user password. Pass the 4688contents of @code{iv.b64} to the second secret 4689 4690@example 4691 # @value{qemu_system} \ 4692 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4693 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4694 data=$SECRET,iv=$(<iv.b64) 4695@end example 4696 4697@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}] 4698 4699Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4700to provide the guest memory encryption support on AMD processors. 4701 4702When memory encryption is enabled, one of the physical address bit (aka the 4703C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4704is used to provide the C-bit position. The C-bit position is Host family dependent 4705hence user must provide this value. On EPYC, the value should be 47. 4706 4707When memory encryption is enabled, we loose certain bits in physical address space. 4708The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4709physical address space. Similar to C-bit, the value is Host family dependent. 4710On EPYC, the value should be 5. 4711 4712The @option{sev-device} provides the device file to use for communicating with 4713the SEV firmware running inside AMD Secure Processor. The default device is 4714'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4715created by CCP driver. 4716 4717The @option{policy} provides the guest policy to be enforced by the SEV firmware 4718and restrict what configuration and operational commands can be performed on this 4719guest by the hypervisor. The policy should be provided by the guest owner and is 4720bound to the guest and cannot be changed throughout the lifetime of the guest. 4721The default is 0. 4722 4723If guest @option{policy} allows sharing the key with another SEV guest then 4724@option{handle} can be use to provide handle of the guest from which to share 4725the key. 4726 4727The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4728Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4729are used for establishing a cryptographic session with the guest owner to 4730negotiate keys used for attestation. The file must be encoded in base64. 4731 4732e.g to launch a SEV guest 4733@example 4734 # @value{qemu_system_x86} \ 4735 ...... 4736 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4737 -machine ...,memory-encryption=sev0 4738 ..... 4739 4740@end example 4741 4742 4743@item -object authz-simple,id=@var{id},identity=@var{string} 4744 4745Create an authorization object that will control access to network services. 4746 4747The @option{identity} parameter is identifies the user and its format 4748depends on the network service that authorization object is associated 4749with. For authorizing based on TLS x509 certificates, the identity must 4750be the x509 distinguished name. Note that care must be taken to escape 4751any commas in the distinguished name. 4752 4753An example authorization object to validate a x509 distinguished name 4754would look like: 4755@example 4756 # @value{qemu_system} \ 4757 ... 4758 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4759 ... 4760@end example 4761 4762Note the use of quotes due to the x509 distinguished name containing 4763whitespace, and escaping of ','. 4764 4765@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4766 4767Create an authorization object that will control access to network services. 4768 4769The @option{filename} parameter is the fully qualified path to a file 4770containing the access control list rules in JSON format. 4771 4772An example set of rules that match against SASL usernames might look 4773like: 4774 4775@example 4776 @{ 4777 "rules": [ 4778 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4779 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4780 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4781 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4782 ], 4783 "policy": "deny" 4784 @} 4785@end example 4786 4787When checking access the object will iterate over all the rules and 4788the first rule to match will have its @option{policy} value returned 4789as the result. If no rules match, then the default @option{policy} 4790value is returned. 4791 4792The rules can either be an exact string match, or they can use the 4793simple UNIX glob pattern matching to allow wildcards to be used. 4794 4795If @option{refresh} is set to true the file will be monitored 4796and automatically reloaded whenever its content changes. 4797 4798As with the @code{authz-simple} object, the format of the identity 4799strings being matched depends on the network service, but is usually 4800a TLS x509 distinguished name, or a SASL username. 4801 4802An example authorization object to validate a SASL username 4803would look like: 4804@example 4805 # @value{qemu_system} \ 4806 ... 4807 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4808 ... 4809@end example 4810 4811@item -object authz-pam,id=@var{id},service=@var{string} 4812 4813Create an authorization object that will control access to network services. 4814 4815The @option{service} parameter provides the name of a PAM service to use 4816for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4817exist to provide the configuration for the @code{account} subsystem. 4818 4819An example authorization object to validate a TLS x509 distinguished 4820name would look like: 4821 4822@example 4823 # @value{qemu_system} \ 4824 ... 4825 -object authz-pam,id=auth0,service=qemu-vnc 4826 ... 4827@end example 4828 4829There would then be a corresponding config file for PAM at 4830@code{/etc/pam.d/qemu-vnc} that contains: 4831 4832@example 4833account requisite pam_listfile.so item=user sense=allow \ 4834 file=/etc/qemu/vnc.allow 4835@end example 4836 4837Finally the @code{/etc/qemu/vnc.allow} file would contain 4838the list of x509 distingished names that are permitted 4839access 4840 4841@example 4842CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4843@end example 4844 4845@item -object iothread,id=@var{id},poll-max-ns=@var{poll-max-ns},poll-grow=@var{poll-grow},poll-shrink=@var{poll-shrink} 4846 4847Creates a dedicated event loop thread that devices can be assigned to. This is 4848known as an IOThread. By default device emulation happens in vCPU threads or 4849the main event loop thread. This can become a scalability bottleneck. 4850IOThreads allow device emulation and I/O to run on other host CPUs. 4851 4852The @option{id} parameter is a unique ID that will be used to reference this 4853IOThread from @option{-device ...,iothread=@var{id}}. Multiple devices can be 4854assigned to an IOThread. Note that not all devices support an 4855@option{iothread} parameter. 4856 4857The @code{query-iothreads} QMP command lists IOThreads and reports their thread 4858IDs so that the user can configure host CPU pinning/affinity. 4859 4860IOThreads use an adaptive polling algorithm to reduce event loop latency. 4861Instead of entering a blocking system call to monitor file descriptors and then 4862pay the cost of being woken up when an event occurs, the polling algorithm 4863spins waiting for events for a short time. The algorithm's default parameters 4864are suitable for many cases but can be adjusted based on knowledge of the 4865workload and/or host device latency. 4866 4867The @option{poll-max-ns} parameter is the maximum number of nanoseconds to busy 4868wait for events. Polling can be disabled by setting this value to 0. 4869 4870The @option{poll-grow} parameter is the multiplier used to increase the polling 4871time when the algorithm detects it is missing events due to not polling long 4872enough. 4873 4874The @option{poll-shrink} parameter is the divisor used to decrease the polling 4875time when the algorithm detects it is spending too long polling without 4876encountering events. 4877 4878The polling parameters can be modified at run-time using the @code{qom-set} command (where @code{iothread1} is the IOThread's @code{id}): 4879 4880@example 4881(qemu) qom-set /objects/iothread1 poll-max-ns 100000 4882@end example 4883 4884@end table 4885 4886ETEXI 4887 4888 4889HXCOMM This is the last statement. Insert new options before this line! 4890STEXI 4891@end table 4892ETEXI 4893
