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 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 36 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 37 " mem-merge=on|off controls memory merge support (default: on)\n" 38 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 39 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 40 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 41 " nvdimm=on|off controls NVDIMM support (default=off)\n" 42 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 43 " memory-encryption=@var{} memory encryption object to use (default=none)\n", 44 QEMU_ARCH_ALL) 45STEXI 46@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 47@findex -machine 48Select the emulated machine by @var{name}. Use @code{-machine help} to list 49available machines. 50 51For architectures which aim to support live migration compatibility 52across releases, each release will introduce a new versioned machine 53type. For example, the 2.8.0 release introduced machine types 54``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. 55 56To allow live migration of guests from QEMU version 2.8.0, to QEMU 57version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' 58and ``pc-q35-2.8'' machines too. To allow users live migrating VMs 59to skip multiple intermediate releases when upgrading, new releases 60of QEMU will support machine types from many previous versions. 61 62Supported machine properties are: 63@table @option 64@item accel=@var{accels1}[:@var{accels2}[:...]] 65This is used to enable an accelerator. Depending on the target architecture, 66kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 67more than one accelerator specified, the next one is used if the previous one 68fails to initialize. 69@item vmport=on|off|auto 70Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 71value based on accel. For accel=xen the default is off otherwise the default 72is on. 73@item dump-guest-core=on|off 74Include guest memory in a core dump. The default is on. 75@item mem-merge=on|off 76Enables or disables memory merge support. This feature, when supported by 77the host, de-duplicates identical memory pages among VMs instances 78(enabled by default). 79@item aes-key-wrap=on|off 80Enables or disables AES key wrapping support on s390-ccw hosts. This feature 81controls whether AES wrapping keys will be created to allow 82execution of AES cryptographic functions. The default is on. 83@item dea-key-wrap=on|off 84Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 85controls whether DEA wrapping keys will be created to allow 86execution of DEA cryptographic functions. The default is on. 87@item nvdimm=on|off 88Enables or disables NVDIMM support. The default is off. 89@item enforce-config-section=on|off 90If @option{enforce-config-section} is set to @var{on}, force migration 91code to send configuration section even if the machine-type sets the 92@option{migration.send-configuration} property to @var{off}. 93NOTE: this parameter is deprecated. Please use @option{-global} 94@option{migration.send-configuration}=@var{on|off} instead. 95@item memory-encryption=@var{} 96Memory encryption object to use. The default is none. 97@end table 98ETEXI 99 100HXCOMM Deprecated by -machine 101DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 102 103DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 104 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 105STEXI 106@item -cpu @var{model} 107@findex -cpu 108Select CPU model (@code{-cpu help} for list and additional feature selection) 109ETEXI 110 111DEF("accel", HAS_ARG, QEMU_OPTION_accel, 112 "-accel [accel=]accelerator[,prop[=value][,...]]\n" 113 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 114 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" 115 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" 116 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" 117 " tb-size=n (TCG translation block cache size)\n" 118 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 119STEXI 120@item -accel @var{name}[,prop=@var{value}[,...]] 121@findex -accel 122This is used to enable an accelerator. Depending on the target architecture, 123kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 124more than one accelerator specified, the next one is used if the previous one 125fails to initialize. 126@table @option 127@item igd-passthru=on|off 128When Xen is in use, this option controls whether Intel integrated graphics 129devices can be passed through to the guest (default=off) 130@item kernel-irqchip=on|off|split 131Controls KVM in-kernel irqchip support. The default is full acceleration of the 132interrupt controllers. On x86, split irqchip reduces the kernel attack 133surface, at a performance cost for non-MSI interrupts. Disabling the in-kernel 134irqchip completely is not recommended except for debugging purposes. 135@item kvm-shadow-mem=size 136Defines the size of the KVM shadow MMU. 137@item tb-size=@var{n} 138Controls the size (in MiB) of the TCG translation block cache. 139@item thread=single|multi 140Controls number of TCG threads. When the TCG is multi-threaded there will be one 141thread per vCPU therefor taking advantage of additional host cores. The default 142is to enable multi-threading where both the back-end and front-ends support it and 143no incompatible TCG features have been enabled (e.g. icount/replay). 144@end table 145ETEXI 146 147DEF("smp", HAS_ARG, QEMU_OPTION_smp, 148 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n" 149 " set the number of CPUs to 'n' [default=1]\n" 150 " maxcpus= maximum number of total cpus, including\n" 151 " offline CPUs for hotplug, etc\n" 152 " cores= number of CPU cores on one socket (for PC, it's on one die)\n" 153 " threads= number of threads on one CPU core\n" 154 " dies= number of CPU dies on one socket (for PC only)\n" 155 " sockets= number of discrete sockets in the system\n", 156 QEMU_ARCH_ALL) 157STEXI 158@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,dies=dies][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 159@findex -smp 160Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 161CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 162to 4. 163For the PC target, the number of @var{cores} per die, the number of @var{threads} 164per cores, the number of @var{dies} per packages and the total number of 165@var{sockets} can be specified. Missing values will be computed. 166If any on the three values is given, the total number of CPUs @var{n} can be omitted. 167@var{maxcpus} specifies the maximum number of hotpluggable CPUs. 168ETEXI 169 170DEF("numa", HAS_ARG, QEMU_OPTION_numa, 171 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 172 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 173 "-numa dist,src=source,dst=destination,val=distance\n" 174 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n", 175 QEMU_ARCH_ALL) 176STEXI 177@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 178@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 179@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 180@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 181@findex -numa 182Define a NUMA node and assign RAM and VCPUs to it. 183Set the NUMA distance from a source node to a destination node. 184 185Legacy VCPU assignment uses @samp{cpus} option where 186@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 187@samp{cpus} option represent a contiguous range of CPU indexes 188(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 189set of VCPUs can be represented by providing multiple @samp{cpus} 190options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 191split between them. 192 193For example, the following option assigns VCPUs 0, 1, 2 and 5 to 194a NUMA node: 195@example 196-numa node,cpus=0-2,cpus=5 197@end example 198 199@samp{cpu} option is a new alternative to @samp{cpus} option 200which uses @samp{socket-id|core-id|thread-id} properties to assign 201CPU objects to a @var{node} using topology layout properties of CPU. 202The set of properties is machine specific, and depends on used 203machine type/@samp{smp} options. It could be queried with 204@samp{hotpluggable-cpus} monitor command. 205@samp{node-id} property specifies @var{node} to which CPU object 206will be assigned, it's required for @var{node} to be declared 207with @samp{node} option before it's used with @samp{cpu} option. 208 209For example: 210@example 211-M pc \ 212-smp 1,sockets=2,maxcpus=2 \ 213-numa node,nodeid=0 -numa node,nodeid=1 \ 214-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 215@end example 216 217@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 218assigns RAM from a given memory backend device to a node. If 219@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 220split equally between them. 221 222@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 223if one node uses @samp{memdev}, all of them have to use it. 224 225@var{source} and @var{destination} are NUMA node IDs. 226@var{distance} is the NUMA distance from @var{source} to @var{destination}. 227The distance from a node to itself is always 10. If any pair of nodes is 228given a distance, then all pairs must be given distances. Although, when 229distances are only given in one direction for each pair of nodes, then 230the distances in the opposite directions are assumed to be the same. If, 231however, an asymmetrical pair of distances is given for even one node 232pair, then all node pairs must be provided distance values for both 233directions, even when they are symmetrical. When a node is unreachable 234from another node, set the pair's distance to 255. 235 236Note that the -@option{numa} option doesn't allocate any of the 237specified resources, it just assigns existing resources to NUMA 238nodes. This means that one still has to use the @option{-m}, 239@option{-smp} options to allocate RAM and VCPUs respectively. 240 241ETEXI 242 243DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 244 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 245 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 246STEXI 247@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 248@findex -add-fd 249 250Add a file descriptor to an fd set. Valid options are: 251 252@table @option 253@item fd=@var{fd} 254This option defines the file descriptor of which a duplicate is added to fd set. 255The file descriptor cannot be stdin, stdout, or stderr. 256@item set=@var{set} 257This option defines the ID of the fd set to add the file descriptor to. 258@item opaque=@var{opaque} 259This option defines a free-form string that can be used to describe @var{fd}. 260@end table 261 262You can open an image using pre-opened file descriptors from an fd set: 263@example 264@value{qemu_system} \ 265 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 266 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 267 -drive file=/dev/fdset/2,index=0,media=disk 268@end example 269ETEXI 270 271DEF("set", HAS_ARG, QEMU_OPTION_set, 272 "-set group.id.arg=value\n" 273 " set <arg> parameter for item <id> of type <group>\n" 274 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 275STEXI 276@item -set @var{group}.@var{id}.@var{arg}=@var{value} 277@findex -set 278Set parameter @var{arg} for item @var{id} of type @var{group} 279ETEXI 280 281DEF("global", HAS_ARG, QEMU_OPTION_global, 282 "-global driver.property=value\n" 283 "-global driver=driver,property=property,value=value\n" 284 " set a global default for a driver property\n", 285 QEMU_ARCH_ALL) 286STEXI 287@item -global @var{driver}.@var{prop}=@var{value} 288@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 289@findex -global 290Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 291 292@example 293@value{qemu_system_x86} -global ide-hd.physical_block_size=4096 disk-image.img 294@end example 295 296In particular, you can use this to set driver properties for devices which are 297created automatically by the machine model. To create a device which is not 298created automatically and set properties on it, use -@option{device}. 299 300-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 301driver=@var{driver},property=@var{prop},value=@var{value}. The 302longhand syntax works even when @var{driver} contains a dot. 303ETEXI 304 305DEF("boot", HAS_ARG, QEMU_OPTION_boot, 306 "-boot [order=drives][,once=drives][,menu=on|off]\n" 307 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 308 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 309 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 310 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 311 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 312 QEMU_ARCH_ALL) 313STEXI 314@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] 315@findex -boot 316Specify boot order @var{drives} as a string of drive letters. Valid 317drive letters depend on the target architecture. The x86 PC uses: a, b 318(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 319from network adapter 1-4), hard disk boot is the default. To apply a 320particular boot order only on the first startup, specify it via 321@option{once}. Note that the @option{order} or @option{once} parameter 322should not be used together with the @option{bootindex} property of 323devices, since the firmware implementations normally do not support both 324at the same time. 325 326Interactive boot menus/prompts can be enabled via @option{menu=on} as far 327as firmware/BIOS supports them. The default is non-interactive boot. 328 329A splash picture could be passed to bios, enabling user to show it as logo, 330when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 331supports them. Currently Seabios for X86 system support it. 332limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 333format(true color). The resolution should be supported by the SVGA mode, so 334the recommended is 320x240, 640x480, 800x640. 335 336A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 337when boot failed, then reboot. If @option{reboot-timeout} is not set, 338guest will not reboot by default. Currently Seabios for X86 339system support it. 340 341Do strict boot via @option{strict=on} as far as firmware/BIOS 342supports it. This only effects when boot priority is changed by 343bootindex options. The default is non-strict boot. 344 345@example 346# try to boot from network first, then from hard disk 347@value{qemu_system_x86} -boot order=nc 348# boot from CD-ROM first, switch back to default order after reboot 349@value{qemu_system_x86} -boot once=d 350# boot with a splash picture for 5 seconds. 351@value{qemu_system_x86} -boot menu=on,splash=/root/boot.bmp,splash-time=5000 352@end example 353 354Note: The legacy format '-boot @var{drives}' is still supported but its 355use is discouraged as it may be removed from future versions. 356ETEXI 357 358DEF("m", HAS_ARG, QEMU_OPTION_m, 359 "-m [size=]megs[,slots=n,maxmem=size]\n" 360 " configure guest RAM\n" 361 " size: initial amount of guest memory\n" 362 " slots: number of hotplug slots (default: none)\n" 363 " maxmem: maximum amount of guest memory (default: none)\n" 364 "NOTE: Some architectures might enforce a specific granularity\n", 365 QEMU_ARCH_ALL) 366STEXI 367@item -m [size=]@var{megs}[,slots=n,maxmem=size] 368@findex -m 369Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 370Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 371megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 372could be used to set amount of hotpluggable memory slots and maximum amount of 373memory. Note that @var{maxmem} must be aligned to the page size. 374 375For example, the following command-line sets the guest startup RAM size to 3761GB, creates 3 slots to hotplug additional memory and sets the maximum 377memory the guest can reach to 4GB: 378 379@example 380@value{qemu_system} -m 1G,slots=3,maxmem=4G 381@end example 382 383If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 384be enabled and the guest startup RAM will never increase. 385ETEXI 386 387DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 388 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 389STEXI 390@item -mem-path @var{path} 391@findex -mem-path 392Allocate guest RAM from a temporarily created file in @var{path}. 393ETEXI 394 395DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 396 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 397 QEMU_ARCH_ALL) 398STEXI 399@item -mem-prealloc 400@findex -mem-prealloc 401Preallocate memory when using -mem-path. 402ETEXI 403 404DEF("k", HAS_ARG, QEMU_OPTION_k, 405 "-k language use keyboard layout (for example 'fr' for French)\n", 406 QEMU_ARCH_ALL) 407STEXI 408@item -k @var{language} 409@findex -k 410Use keyboard layout @var{language} (for example @code{fr} for 411French). This option is only needed where it is not easy to get raw PC 412keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 413display). You don't normally need to use it on PC/Linux or PC/Windows 414hosts. 415 416The available layouts are: 417@example 418ar de-ch es fo fr-ca hu ja mk no pt-br sv 419da en-gb et fr fr-ch is lt nl pl ru th 420de en-us fi fr-be hr it lv nl-be pt sl tr 421@end example 422 423The default is @code{en-us}. 424ETEXI 425 426 427HXCOMM Deprecated by -audiodev 428DEF("audio-help", 0, QEMU_OPTION_audio_help, 429 "-audio-help show -audiodev equivalent of the currently specified audio settings\n", 430 QEMU_ARCH_ALL) 431STEXI 432@item -audio-help 433@findex -audio-help 434Will show the -audiodev equivalent of the currently specified 435(deprecated) environment variables. 436ETEXI 437 438DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, 439 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n" 440 " specifies the audio backend to use\n" 441 " id= identifier of the backend\n" 442 " timer-period= timer period in microseconds\n" 443 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n" 444 " in|out.fixed-settings= use fixed settings for host audio\n" 445 " in|out.frequency= frequency to use with fixed settings\n" 446 " in|out.channels= number of channels to use with fixed settings\n" 447 " in|out.format= sample format to use with fixed settings\n" 448 " valid values: s8, s16, s32, u8, u16, u32\n" 449 " in|out.voices= number of voices to use\n" 450 " in|out.buffer-length= length of buffer in microseconds\n" 451 "-audiodev none,id=id,[,prop[=value][,...]]\n" 452 " dummy driver that discards all output\n" 453#ifdef CONFIG_AUDIO_ALSA 454 "-audiodev alsa,id=id[,prop[=value][,...]]\n" 455 " in|out.dev= name of the audio device to use\n" 456 " in|out.period-length= length of period in microseconds\n" 457 " in|out.try-poll= attempt to use poll mode\n" 458 " threshold= threshold (in microseconds) when playback starts\n" 459#endif 460#ifdef CONFIG_AUDIO_COREAUDIO 461 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n" 462 " in|out.buffer-count= number of buffers\n" 463#endif 464#ifdef CONFIG_AUDIO_DSOUND 465 "-audiodev dsound,id=id[,prop[=value][,...]]\n" 466 " latency= add extra latency to playback in microseconds\n" 467#endif 468#ifdef CONFIG_AUDIO_OSS 469 "-audiodev oss,id=id[,prop[=value][,...]]\n" 470 " in|out.dev= path of the audio device to use\n" 471 " in|out.buffer-count= number of buffers\n" 472 " in|out.try-poll= attempt to use poll mode\n" 473 " try-mmap= try using memory mapped access\n" 474 " exclusive= open device in exclusive mode\n" 475 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n" 476#endif 477#ifdef CONFIG_AUDIO_PA 478 "-audiodev pa,id=id[,prop[=value][,...]]\n" 479 " server= PulseAudio server address\n" 480 " in|out.name= source/sink device name\n" 481 " in|out.latency= desired latency in microseconds\n" 482#endif 483#ifdef CONFIG_AUDIO_SDL 484 "-audiodev sdl,id=id[,prop[=value][,...]]\n" 485#endif 486#ifdef CONFIG_SPICE 487 "-audiodev spice,id=id[,prop[=value][,...]]\n" 488#endif 489 "-audiodev wav,id=id[,prop[=value][,...]]\n" 490 " path= path of wav file to record\n", 491 QEMU_ARCH_ALL) 492STEXI 493@item -audiodev [driver=]@var{driver},id=@var{id}[,@var{prop}[=@var{value}][,...]] 494@findex -audiodev 495Adds a new audio backend @var{driver} identified by @var{id}. There are 496global and driver specific properties. Some values can be set 497differently for input and output, they're marked with @code{in|out.}. 498You can set the input's property with @code{in.@var{prop}} and the 499output's property with @code{out.@var{prop}}. For example: 500@example 501-audiodev alsa,id=example,in.frequency=44110,out.frequency=8000 502-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified 503@end example 504 505NOTE: parameter validation is known to be incomplete, in many cases 506specifying an invalid option causes QEMU to print an error message and 507continue emulation without sound. 508 509Valid global options are: 510 511@table @option 512@item id=@var{identifier} 513Identifies the audio backend. 514 515@item timer-period=@var{period} 516Sets the timer @var{period} used by the audio subsystem in microseconds. 517Default is 10000 (10 ms). 518 519@item in|out.mixing-engine=on|off 520Use QEMU's mixing engine to mix all streams inside QEMU and convert 521audio formats when not supported by the backend. When off, 522@var{fixed-settings} must be off too. Note that disabling this option 523means that the selected backend must support multiple streams and the 524audio formats used by the virtual cards, otherwise you'll get no sound. 525It's not recommended to disable this option unless you want to use 5.1 526or 7.1 audio, as mixing engine only supports mono and stereo audio. 527Default is on. 528 529@item in|out.fixed-settings=on|off 530Use fixed settings for host audio. When off, it will change based on 531how the guest opens the sound card. In this case you must not specify 532@var{frequency}, @var{channels} or @var{format}. Default is on. 533 534@item in|out.frequency=@var{frequency} 535Specify the @var{frequency} to use when using @var{fixed-settings}. 536Default is 44100Hz. 537 538@item in|out.channels=@var{channels} 539Specify the number of @var{channels} to use when using 540@var{fixed-settings}. Default is 2 (stereo). 541 542@item in|out.format=@var{format} 543Specify the sample @var{format} to use when using @var{fixed-settings}. 544Valid values are: @code{s8}, @code{s16}, @code{s32}, @code{u8}, 545@code{u16}, @code{u32}. Default is @code{s16}. 546 547@item in|out.voices=@var{voices} 548Specify the number of @var{voices} to use. Default is 1. 549 550@item in|out.buffer-length=@var{usecs} 551Sets the size of the buffer in microseconds. 552 553@end table 554 555@item -audiodev none,id=@var{id}[,@var{prop}[=@var{value}][,...]] 556Creates a dummy backend that discards all outputs. This backend has no 557backend specific properties. 558 559@item -audiodev alsa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 560Creates backend using the ALSA. This backend is only available on 561Linux. 562 563ALSA specific options are: 564 565@table @option 566 567@item in|out.dev=@var{device} 568Specify the ALSA @var{device} to use for input and/or output. Default 569is @code{default}. 570 571@item in|out.period-length=@var{usecs} 572Sets the period length in microseconds. 573 574@item in|out.try-poll=on|off 575Attempt to use poll mode with the device. Default is on. 576 577@item threshold=@var{threshold} 578Threshold (in microseconds) when playback starts. Default is 0. 579 580@end table 581 582@item -audiodev coreaudio,id=@var{id}[,@var{prop}[=@var{value}][,...]] 583Creates a backend using Apple's Core Audio. This backend is only 584available on Mac OS and only supports playback. 585 586Core Audio specific options are: 587 588@table @option 589 590@item in|out.buffer-count=@var{count} 591Sets the @var{count} of the buffers. 592 593@end table 594 595@item -audiodev dsound,id=@var{id}[,@var{prop}[=@var{value}][,...]] 596Creates a backend using Microsoft's DirectSound. This backend is only 597available on Windows and only supports playback. 598 599DirectSound specific options are: 600 601@table @option 602 603@item latency=@var{usecs} 604Add extra @var{usecs} microseconds latency to playback. Default is 60510000 (10 ms). 606 607@end table 608 609@item -audiodev oss,id=@var{id}[,@var{prop}[=@var{value}][,...]] 610Creates a backend using OSS. This backend is available on most 611Unix-like systems. 612 613OSS specific options are: 614 615@table @option 616 617@item in|out.dev=@var{device} 618Specify the file name of the OSS @var{device} to use. Default is 619@code{/dev/dsp}. 620 621@item in|out.buffer-count=@var{count} 622Sets the @var{count} of the buffers. 623 624@item in|out.try-poll=on|of 625Attempt to use poll mode with the device. Default is on. 626 627@item try-mmap=on|off 628Try using memory mapped device access. Default is off. 629 630@item exclusive=on|off 631Open the device in exclusive mode (vmix won't work in this case). 632Default is off. 633 634@item dsp-policy=@var{policy} 635Sets the timing policy (between 0 and 10, where smaller number means 636smaller latency but higher CPU usage). Use -1 to use buffer sizes 637specified by @code{buffer} and @code{buffer-count}. This option is 638ignored if you do not have OSS 4. Default is 5. 639 640@end table 641 642@item -audiodev pa,id=@var{id}[,@var{prop}[=@var{value}][,...]] 643Creates a backend using PulseAudio. This backend is available on most 644systems. 645 646PulseAudio specific options are: 647 648@table @option 649 650@item server=@var{server} 651Sets the PulseAudio @var{server} to connect to. 652 653@item in|out.name=@var{sink} 654Use the specified source/sink for recording/playback. 655 656@item in|out.latency=@var{usecs} 657Desired latency in microseconds. The PulseAudio server will try to honor this 658value but actual latencies may be lower or higher. 659 660@end table 661 662@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]] 663Creates a backend using SDL. This backend is available on most systems, 664but you should use your platform's native backend if possible. This 665backend has no backend specific properties. 666 667@item -audiodev spice,id=@var{id}[,@var{prop}[=@var{value}][,...]] 668Creates a backend that sends audio through SPICE. This backend requires 669@code{-spice} and automatically selected in that case, so usually you 670can ignore this option. This backend has no backend specific 671properties. 672 673@item -audiodev wav,id=@var{id}[,@var{prop}[=@var{value}][,...]] 674Creates a backend that writes audio to a WAV file. 675 676Backend specific options are: 677 678@table @option 679 680@item path=@var{path} 681Write recorded audio into the specified file. Default is 682@code{qemu.wav}. 683 684@end table 685ETEXI 686 687DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 688 "-soundhw c1,... enable audio support\n" 689 " and only specified sound cards (comma separated list)\n" 690 " use '-soundhw help' to get the list of supported cards\n" 691 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 692STEXI 693@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 694@findex -soundhw 695Enable audio and selected sound hardware. Use 'help' to print all 696available sound hardware. For example: 697 698@example 699@value{qemu_system_x86} -soundhw sb16,adlib disk.img 700@value{qemu_system_x86} -soundhw es1370 disk.img 701@value{qemu_system_x86} -soundhw ac97 disk.img 702@value{qemu_system_x86} -soundhw hda disk.img 703@value{qemu_system_x86} -soundhw all disk.img 704@value{qemu_system_x86} -soundhw help 705@end example 706 707Note that Linux's i810_audio OSS kernel (for AC97) module might 708require manually specifying clocking. 709 710@example 711modprobe i810_audio clocking=48000 712@end example 713ETEXI 714 715DEF("device", HAS_ARG, QEMU_OPTION_device, 716 "-device driver[,prop[=value][,...]]\n" 717 " add device (based on driver)\n" 718 " prop=value,... sets driver properties\n" 719 " use '-device help' to print all possible drivers\n" 720 " use '-device driver,help' to print all possible properties\n", 721 QEMU_ARCH_ALL) 722STEXI 723@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 724@findex -device 725Add device @var{driver}. @var{prop}=@var{value} sets driver 726properties. Valid properties depend on the driver. To get help on 727possible drivers and properties, use @code{-device help} and 728@code{-device @var{driver},help}. 729 730Some drivers are: 731@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}] 732 733Add an IPMI BMC. This is a simulation of a hardware management 734interface processor that normally sits on a system. It provides 735a watchdog and the ability to reset and power control the system. 736You need to connect this to an IPMI interface to make it useful 737 738The IPMI slave address to use for the BMC. The default is 0x20. 739This address is the BMC's address on the I2C network of management 740controllers. If you don't know what this means, it is safe to ignore 741it. 742 743@table @option 744@item id=@var{id} 745The BMC id for interfaces to use this device. 746@item slave_addr=@var{val} 747Define slave address to use for the BMC. The default is 0x20. 748@item sdrfile=@var{file} 749file containing raw Sensor Data Records (SDR) data. The default is none. 750@item fruareasize=@var{val} 751size of a Field Replaceable Unit (FRU) area. The default is 1024. 752@item frudatafile=@var{file} 753file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 754@item guid=@var{uuid} 755value for the GUID for the BMC, in standard UUID format. If this is set, 756get "Get GUID" command to the BMC will return it. Otherwise "Get GUID" 757will return an error. 758@end table 759 760@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 761 762Add a connection to an external IPMI BMC simulator. Instead of 763locally emulating the BMC like the above item, instead connect 764to an external entity that provides the IPMI services. 765 766A connection is made to an external BMC simulator. If you do this, it 767is strongly recommended that you use the "reconnect=" chardev option 768to reconnect to the simulator if the connection is lost. Note that if 769this is not used carefully, it can be a security issue, as the 770interface has the ability to send resets, NMIs, and power off the VM. 771It's best if QEMU makes a connection to an external simulator running 772on a secure port on localhost, so neither the simulator nor QEMU is 773exposed to any outside network. 774 775See the "lanserv/README.vm" file in the OpenIPMI library for more 776details on the external interface. 777 778@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 779 780Add a KCS IPMI interafce on the ISA bus. This also adds a 781corresponding ACPI and SMBIOS entries, if appropriate. 782 783@table @option 784@item bmc=@var{id} 785The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 786@item ioport=@var{val} 787Define the I/O address of the interface. The default is 0xca0 for KCS. 788@item irq=@var{val} 789Define the interrupt to use. The default is 5. To disable interrupts, 790set this to 0. 791@end table 792 793@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 794 795Like the KCS interface, but defines a BT interface. The default port is 7960xe4 and the default interrupt is 5. 797 798ETEXI 799 800DEF("name", HAS_ARG, QEMU_OPTION_name, 801 "-name string1[,process=string2][,debug-threads=on|off]\n" 802 " set the name of the guest\n" 803 " string1 sets the window title and string2 the process name\n" 804 " When debug-threads is enabled, individual threads are given a separate name\n" 805 " NOTE: The thread names are for debugging and not a stable API.\n", 806 QEMU_ARCH_ALL) 807STEXI 808@item -name @var{name} 809@findex -name 810Sets the @var{name} of the guest. 811This name will be displayed in the SDL window caption. 812The @var{name} will also be used for the VNC server. 813Also optionally set the top visible process name in Linux. 814Naming of individual threads can also be enabled on Linux to aid debugging. 815ETEXI 816 817DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 818 "-uuid %08x-%04x-%04x-%04x-%012x\n" 819 " specify machine UUID\n", QEMU_ARCH_ALL) 820STEXI 821@item -uuid @var{uuid} 822@findex -uuid 823Set system UUID. 824ETEXI 825 826STEXI 827@end table 828ETEXI 829DEFHEADING() 830 831DEFHEADING(Block device options:) 832STEXI 833@table @option 834ETEXI 835 836DEF("fda", HAS_ARG, QEMU_OPTION_fda, 837 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 838DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 839STEXI 840@item -fda @var{file} 841@itemx -fdb @var{file} 842@findex -fda 843@findex -fdb 844Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 845ETEXI 846 847DEF("hda", HAS_ARG, QEMU_OPTION_hda, 848 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 849DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 850DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 851 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 852DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 853STEXI 854@item -hda @var{file} 855@itemx -hdb @var{file} 856@itemx -hdc @var{file} 857@itemx -hdd @var{file} 858@findex -hda 859@findex -hdb 860@findex -hdc 861@findex -hdd 862Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 863ETEXI 864 865DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 866 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 867 QEMU_ARCH_ALL) 868STEXI 869@item -cdrom @var{file} 870@findex -cdrom 871Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 872@option{-cdrom} at the same time). You can use the host CD-ROM by 873using @file{/dev/cdrom} as filename (@pxref{host_drives}). 874ETEXI 875 876DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 877 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 878 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 879 " [,read-only=on|off][,auto-read-only=on|off]\n" 880 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n" 881 " [,driver specific parameters...]\n" 882 " configure a block backend\n", QEMU_ARCH_ALL) 883STEXI 884@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 885@findex -blockdev 886 887Define a new block driver node. Some of the options apply to all block drivers, 888other options are only accepted for a specific block driver. See below for a 889list of generic options and options for the most common block drivers. 890 891Options that expect a reference to another node (e.g. @code{file}) can be 892given in two ways. Either you specify the node name of an already existing node 893(file=@var{node-name}), or you define a new node inline, adding options 894for the referenced node after a dot (file.filename=@var{path},file.aio=native). 895 896A block driver node created with @option{-blockdev} can be used for a guest 897device by specifying its node name for the @code{drive} property in a 898@option{-device} argument that defines a block device. 899 900@table @option 901@item Valid options for any block driver node: 902 903@table @code 904@item driver 905Specifies the block driver to use for the given node. 906@item node-name 907This defines the name of the block driver node by which it will be referenced 908later. The name must be unique, i.e. it must not match the name of a different 909block driver node, or (if you use @option{-drive} as well) the ID of a drive. 910 911If no node name is specified, it is automatically generated. The generated node 912name is not intended to be predictable and changes between QEMU invocations. 913For the top level, an explicit node name must be specified. 914@item read-only 915Open the node read-only. Guest write attempts will fail. 916 917Note that some block drivers support only read-only access, either generally or 918in certain configurations. In this case, the default value 919@option{read-only=off} does not work and the option must be specified 920explicitly. 921@item auto-read-only 922If @option{auto-read-only=on} is set, QEMU may fall back to read-only usage 923even when @option{read-only=off} is requested, or even switch between modes as 924needed, e.g. depending on whether the image file is writable or whether a 925writing user is attached to the node. 926@item force-share 927Override the image locking system of QEMU by forcing the node to utilize 928weaker shared access for permissions where it would normally request exclusive 929access. When there is the potential for multiple instances to have the same 930file open (whether this invocation of QEMU is the first or the second 931instance), both instances must permit shared access for the second instance to 932succeed at opening the file. 933 934Enabling @option{force-share=on} requires @option{read-only=on}. 935@item cache.direct 936The host page cache can be avoided with @option{cache.direct=on}. This will 937attempt to do disk IO directly to the guest's memory. QEMU may still perform an 938internal copy of the data. 939@item cache.no-flush 940In case you don't care about data integrity over host failures, you can use 941@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 942any data to the disk but can instead keep things in cache. If anything goes 943wrong, like your host losing power, the disk storage getting disconnected 944accidentally, etc. your image will most probably be rendered unusable. 945@item discard=@var{discard} 946@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 947whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 948ignored or passed to the filesystem. Some machine types may not support 949discard requests. 950@item detect-zeroes=@var{detect-zeroes} 951@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 952conversion of plain zero writes by the OS to driver specific optimized 953zero write commands. You may even choose "unmap" if @var{discard} is set 954to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 955@end table 956 957@item Driver-specific options for @code{file} 958 959This is the protocol-level block driver for accessing regular files. 960 961@table @code 962@item filename 963The path to the image file in the local filesystem 964@item aio 965Specifies the AIO backend (threads/native, default: threads) 966@item locking 967Specifies whether the image file is protected with Linux OFD / POSIX locks. The 968default is to use the Linux Open File Descriptor API if available, otherwise no 969lock is applied. (auto/on/off, default: auto) 970@end table 971Example: 972@example 973-blockdev driver=file,node-name=disk,filename=disk.img 974@end example 975 976@item Driver-specific options for @code{raw} 977 978This is the image format block driver for raw images. It is usually 979stacked on top of a protocol level block driver such as @code{file}. 980 981@table @code 982@item file 983Reference to or definition of the data source block driver node 984(e.g. a @code{file} driver node) 985@end table 986Example 1: 987@example 988-blockdev driver=file,node-name=disk_file,filename=disk.img 989-blockdev driver=raw,node-name=disk,file=disk_file 990@end example 991Example 2: 992@example 993-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 994@end example 995 996@item Driver-specific options for @code{qcow2} 997 998This is the image format block driver for qcow2 images. It is usually 999stacked on top of a protocol level block driver such as @code{file}. 1000 1001@table @code 1002@item file 1003Reference to or definition of the data source block driver node 1004(e.g. a @code{file} driver node) 1005 1006@item backing 1007Reference to or definition of the backing file block device (default is taken 1008from the image file). It is allowed to pass @code{null} here in order to disable 1009the default backing file. 1010 1011@item lazy-refcounts 1012Whether to enable the lazy refcounts feature (on/off; default is taken from the 1013image file) 1014 1015@item cache-size 1016The maximum total size of the L2 table and refcount block caches in bytes 1017(default: the sum of l2-cache-size and refcount-cache-size) 1018 1019@item l2-cache-size 1020The maximum size of the L2 table cache in bytes 1021(default: if cache-size is not specified - 32M on Linux platforms, and 8M on 1022non-Linux platforms; otherwise, as large as possible within the cache-size, 1023while permitting the requested or the minimal refcount cache size) 1024 1025@item refcount-cache-size 1026The maximum size of the refcount block cache in bytes 1027(default: 4 times the cluster size; or if cache-size is specified, the part of 1028it which is not used for the L2 cache) 1029 1030@item cache-clean-interval 1031Clean unused entries in the L2 and refcount caches. The interval is in seconds. 1032The default value is 600 on supporting platforms, and 0 on other platforms. 1033Setting it to 0 disables this feature. 1034 1035@item pass-discard-request 1036Whether discard requests to the qcow2 device should be forwarded to the data 1037source (on/off; default: on if discard=unmap is specified, off otherwise) 1038 1039@item pass-discard-snapshot 1040Whether discard requests for the data source should be issued when a snapshot 1041operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 1042default: on) 1043 1044@item pass-discard-other 1045Whether discard requests for the data source should be issued on other 1046occasions where a cluster gets freed (on/off; default: off) 1047 1048@item overlap-check 1049Which overlap checks to perform for writes to the image 1050(none/constant/cached/all; default: cached). For details or finer 1051granularity control refer to the QAPI documentation of @code{blockdev-add}. 1052@end table 1053 1054Example 1: 1055@example 1056-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 1057-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 1058@end example 1059Example 2: 1060@example 1061-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 1062@end example 1063 1064@item Driver-specific options for other drivers 1065Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 1066 1067@end table 1068 1069ETEXI 1070 1071DEF("drive", HAS_ARG, QEMU_OPTION_drive, 1072 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 1073 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 1074 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 1075 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 1076 " [,readonly=on|off][,copy-on-read=on|off]\n" 1077 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 1078 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 1079 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 1080 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 1081 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 1082 " [[,iops_size=is]]\n" 1083 " [[,group=g]]\n" 1084 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 1085STEXI 1086@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 1087@findex -drive 1088 1089Define a new drive. This includes creating a block driver node (the backend) as 1090well as a guest device, and is mostly a shortcut for defining the corresponding 1091@option{-blockdev} and @option{-device} options. 1092 1093@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 1094addition, it knows the following options: 1095 1096@table @option 1097@item file=@var{file} 1098This option defines which disk image (@pxref{disk_images}) to use with 1099this drive. If the filename contains comma, you must double it 1100(for instance, "file=my,,file" to use file "my,file"). 1101 1102Special files such as iSCSI devices can be specified using protocol 1103specific URLs. See the section for "Device URL Syntax" for more information. 1104@item if=@var{interface} 1105This option defines on which type on interface the drive is connected. 1106Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 1107@item bus=@var{bus},unit=@var{unit} 1108These options define where is connected the drive by defining the bus number and 1109the unit id. 1110@item index=@var{index} 1111This option defines where is connected the drive by using an index in the list 1112of available connectors of a given interface type. 1113@item media=@var{media} 1114This option defines the type of the media: disk or cdrom. 1115@item snapshot=@var{snapshot} 1116@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 1117(see @option{-snapshot}). 1118@item cache=@var{cache} 1119@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 1120and controls how the host cache is used to access block data. This is a 1121shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 1122options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 1123which provides a default for the @option{write-cache} option of block guest 1124devices (as in @option{-device}). The modes correspond to the following 1125settings: 1126 1127@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 1128@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 1129@c and the HTML output. 1130@example 1131@ │ cache.writeback cache.direct cache.no-flush 1132─────────────┼───────────────────────────────────────────────── 1133writeback │ on off off 1134none │ on on off 1135writethrough │ off off off 1136directsync │ off on off 1137unsafe │ on off on 1138@end example 1139 1140The default mode is @option{cache=writeback}. 1141 1142@item aio=@var{aio} 1143@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 1144@item format=@var{format} 1145Specify which disk @var{format} will be used rather than detecting 1146the format. Can be used to specify format=raw to avoid interpreting 1147an untrusted format header. 1148@item werror=@var{action},rerror=@var{action} 1149Specify which @var{action} to take on write and read errors. Valid actions are: 1150"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 1151"report" (report the error to the guest), "enospc" (pause QEMU only if the 1152host disk is full; report the error to the guest otherwise). 1153The default setting is @option{werror=enospc} and @option{rerror=report}. 1154@item copy-on-read=@var{copy-on-read} 1155@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 1156file sectors into the image file. 1157@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 1158Specify bandwidth throttling limits in bytes per second, either for all request 1159types or for reads or writes only. Small values can lead to timeouts or hangs 1160inside the guest. A safe minimum for disks is 2 MB/s. 1161@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 1162Specify bursts in bytes per second, either for all request types or for reads 1163or writes only. Bursts allow the guest I/O to spike above the limit 1164temporarily. 1165@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 1166Specify request rate limits in requests per second, either for all request 1167types or for reads or writes only. 1168@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 1169Specify bursts in requests per second, either for all request types or for reads 1170or writes only. Bursts allow the guest I/O to spike above the limit 1171temporarily. 1172@item iops_size=@var{is} 1173Let every @var{is} bytes of a request count as a new request for iops 1174throttling purposes. Use this option to prevent guests from circumventing iops 1175limits by sending fewer but larger requests. 1176@item group=@var{g} 1177Join a throttling quota group with given name @var{g}. All drives that are 1178members of the same group are accounted for together. Use this option to 1179prevent guests from circumventing throttling limits by using many small disks 1180instead of a single larger disk. 1181@end table 1182 1183By default, the @option{cache.writeback=on} mode is used. It will report data 1184writes as completed as soon as the data is present in the host page cache. 1185This is safe as long as your guest OS makes sure to correctly flush disk caches 1186where needed. If your guest OS does not handle volatile disk write caches 1187correctly and your host crashes or loses power, then the guest may experience 1188data corruption. 1189 1190For such guests, you should consider using @option{cache.writeback=off}. This 1191means that the host page cache will be used to read and write data, but write 1192notification will be sent to the guest only after QEMU has made sure to flush 1193each write to the disk. Be aware that this has a major impact on performance. 1194 1195When using the @option{-snapshot} option, unsafe caching is always used. 1196 1197Copy-on-read avoids accessing the same backing file sectors repeatedly and is 1198useful when the backing file is over a slow network. By default copy-on-read 1199is off. 1200 1201Instead of @option{-cdrom} you can use: 1202@example 1203@value{qemu_system} -drive file=file,index=2,media=cdrom 1204@end example 1205 1206Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 1207use: 1208@example 1209@value{qemu_system} -drive file=file,index=0,media=disk 1210@value{qemu_system} -drive file=file,index=1,media=disk 1211@value{qemu_system} -drive file=file,index=2,media=disk 1212@value{qemu_system} -drive file=file,index=3,media=disk 1213@end example 1214 1215You can open an image using pre-opened file descriptors from an fd set: 1216@example 1217@value{qemu_system} \ 1218 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \ 1219 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \ 1220 -drive file=/dev/fdset/2,index=0,media=disk 1221@end example 1222 1223You can connect a CDROM to the slave of ide0: 1224@example 1225@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom 1226@end example 1227 1228If you don't specify the "file=" argument, you define an empty drive: 1229@example 1230@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom 1231@end example 1232 1233Instead of @option{-fda}, @option{-fdb}, you can use: 1234@example 1235@value{qemu_system_x86} -drive file=file,index=0,if=floppy 1236@value{qemu_system_x86} -drive file=file,index=1,if=floppy 1237@end example 1238 1239By default, @var{interface} is "ide" and @var{index} is automatically 1240incremented: 1241@example 1242@value{qemu_system_x86} -drive file=a -drive file=b" 1243@end example 1244is interpreted like: 1245@example 1246@value{qemu_system_x86} -hda a -hdb b 1247@end example 1248ETEXI 1249 1250DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 1251 "-mtdblock file use 'file' as on-board Flash memory image\n", 1252 QEMU_ARCH_ALL) 1253STEXI 1254@item -mtdblock @var{file} 1255@findex -mtdblock 1256Use @var{file} as on-board Flash memory image. 1257ETEXI 1258 1259DEF("sd", HAS_ARG, QEMU_OPTION_sd, 1260 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 1261STEXI 1262@item -sd @var{file} 1263@findex -sd 1264Use @var{file} as SecureDigital card image. 1265ETEXI 1266 1267DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 1268 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 1269STEXI 1270@item -pflash @var{file} 1271@findex -pflash 1272Use @var{file} as a parallel flash image. 1273ETEXI 1274 1275DEF("snapshot", 0, QEMU_OPTION_snapshot, 1276 "-snapshot write to temporary files instead of disk image files\n", 1277 QEMU_ARCH_ALL) 1278STEXI 1279@item -snapshot 1280@findex -snapshot 1281Write to temporary files instead of disk image files. In this case, 1282the raw disk image you use is not written back. You can however force 1283the write back by pressing @key{C-a s} (@pxref{disk_images}). 1284ETEXI 1285 1286DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1287 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1288 " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" 1289 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1290 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1291 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1292 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1293 " [[,throttling.iops-size=is]]\n" 1294 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n" 1295 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n" 1296 "-fsdev synth,id=id\n", 1297 QEMU_ARCH_ALL) 1298 1299STEXI 1300 1301@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}[,...]]] 1302@itemx -fsdev proxy,id=@var{id},socket=@var{socket}[,writeout=@var{writeout}][,readonly] 1303@itemx -fsdev proxy,id=@var{id},sock_fd=@var{sock_fd}[,writeout=@var{writeout}][,readonly] 1304@itemx -fsdev synth,id=@var{id}[,readonly] 1305@findex -fsdev 1306Define a new file system device. Valid options are: 1307@table @option 1308@item local 1309Accesses to the filesystem are done by QEMU. 1310@item proxy 1311Accesses to the filesystem are done by virtfs-proxy-helper(1). 1312@item synth 1313Synthetic filesystem, only used by QTests. 1314@item id=@var{id} 1315Specifies identifier for this device. 1316@item path=@var{path} 1317Specifies the export path for the file system device. Files under 1318this path will be available to the 9p client on the guest. 1319@item security_model=@var{security_model} 1320Specifies the security model to be used for this export path. 1321Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1322In "passthrough" security model, files are stored using the same 1323credentials as they are created on the guest. This requires QEMU 1324to run as root. In "mapped-xattr" security model, some of the file 1325attributes like uid, gid, mode bits and link target are stored as 1326file attributes. For "mapped-file" these attributes are stored in the 1327hidden .virtfs_metadata directory. Directories exported by this security model cannot 1328interact with other unix tools. "none" security model is same as 1329passthrough except the sever won't report failures if it fails to 1330set file attributes like ownership. Security model is mandatory 1331only for local fsdriver. Other fsdrivers (like proxy) don't take 1332security model as a parameter. 1333@item writeout=@var{writeout} 1334This is an optional argument. The only supported value is "immediate". 1335This means that host page cache will be used to read and write data but 1336write notification will be sent to the guest only when the data has been 1337reported as written by the storage subsystem. 1338@item readonly 1339Enables exporting 9p share as a readonly mount for guests. By default 1340read-write access is given. 1341@item socket=@var{socket} 1342Enables proxy filesystem driver to use passed socket file for communicating 1343with virtfs-proxy-helper(1). 1344@item sock_fd=@var{sock_fd} 1345Enables proxy filesystem driver to use passed socket descriptor for 1346communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1347will create socketpair and pass one of the fds as sock_fd. 1348@item fmode=@var{fmode} 1349Specifies the default mode for newly created files on the host. Works only 1350with security models "mapped-xattr" and "mapped-file". 1351@item dmode=@var{dmode} 1352Specifies the default mode for newly created directories on the host. Works 1353only with security models "mapped-xattr" and "mapped-file". 1354@item throttling.bps-total=@var{b},throttling.bps-read=@var{r},throttling.bps-write=@var{w} 1355Specify bandwidth throttling limits in bytes per second, either for all request 1356types or for reads or writes only. 1357@item throttling.bps-total-max=@var{bm},bps-read-max=@var{rm},bps-write-max=@var{wm} 1358Specify bursts in bytes per second, either for all request types or for reads 1359or writes only. Bursts allow the guest I/O to spike above the limit 1360temporarily. 1361@item throttling.iops-total=@var{i},throttling.iops-read=@var{r}, throttling.iops-write=@var{w} 1362Specify request rate limits in requests per second, either for all request 1363types or for reads or writes only. 1364@item throttling.iops-total-max=@var{im},throttling.iops-read-max=@var{irm}, throttling.iops-write-max=@var{iwm} 1365Specify bursts in requests per second, either for all request types or for reads 1366or writes only. Bursts allow the guest I/O to spike above the limit temporarily. 1367@item throttling.iops-size=@var{is} 1368Let every @var{is} bytes of a request count as a new request for iops 1369throttling purposes. 1370@end table 1371 1372-fsdev option is used along with -device driver "virtio-9p-...". 1373@item -device virtio-9p-@var{type},fsdev=@var{id},mount_tag=@var{mount_tag} 1374Options for virtio-9p-... driver are: 1375@table @option 1376@item @var{type} 1377Specifies the variant to be used. Supported values are "pci", "ccw" or "device", 1378depending on the machine type. 1379@item fsdev=@var{id} 1380Specifies the id value specified along with -fsdev option. 1381@item mount_tag=@var{mount_tag} 1382Specifies the tag name to be used by the guest to mount this export point. 1383@end table 1384 1385ETEXI 1386 1387DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1388 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" 1389 " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" 1390 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" 1391 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" 1392 "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", 1393 QEMU_ARCH_ALL) 1394 1395STEXI 1396 1397@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}] 1398@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1399@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] 1400@itemx -virtfs synth,mount_tag=@var{mount_tag} 1401@findex -virtfs 1402 1403Define 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: 1404@table @option 1405@item local 1406Accesses to the filesystem are done by QEMU. 1407@item proxy 1408Accesses to the filesystem are done by virtfs-proxy-helper(1). 1409@item synth 1410Synthetic filesystem, only used by QTests. 1411@item id=@var{id} 1412Specifies identifier for the filesystem device 1413@item path=@var{path} 1414Specifies the export path for the file system device. Files under 1415this path will be available to the 9p client on the guest. 1416@item security_model=@var{security_model} 1417Specifies the security model to be used for this export path. 1418Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1419In "passthrough" security model, files are stored using the same 1420credentials as they are created on the guest. This requires QEMU 1421to run as root. In "mapped-xattr" security model, some of the file 1422attributes like uid, gid, mode bits and link target are stored as 1423file attributes. For "mapped-file" these attributes are stored in the 1424hidden .virtfs_metadata directory. Directories exported by this security model cannot 1425interact with other unix tools. "none" security model is same as 1426passthrough except the sever won't report failures if it fails to 1427set file attributes like ownership. Security model is mandatory only 1428for local fsdriver. Other fsdrivers (like proxy) don't take security 1429model as a parameter. 1430@item writeout=@var{writeout} 1431This is an optional argument. The only supported value is "immediate". 1432This means that host page cache will be used to read and write data but 1433write notification will be sent to the guest only when the data has been 1434reported as written by the storage subsystem. 1435@item readonly 1436Enables exporting 9p share as a readonly mount for guests. By default 1437read-write access is given. 1438@item socket=@var{socket} 1439Enables proxy filesystem driver to use passed socket file for 1440communicating with virtfs-proxy-helper(1). Usually a helper like libvirt 1441will create socketpair and pass one of the fds as sock_fd. 1442@item sock_fd 1443Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1444descriptor for interfacing with virtfs-proxy-helper(1). 1445@item fmode=@var{fmode} 1446Specifies the default mode for newly created files on the host. Works only 1447with security models "mapped-xattr" and "mapped-file". 1448@item dmode=@var{dmode} 1449Specifies the default mode for newly created directories on the host. Works 1450only with security models "mapped-xattr" and "mapped-file". 1451@item mount_tag=@var{mount_tag} 1452Specifies the tag name to be used by the guest to mount this export point. 1453@item multidevs=@var{multidevs} 1454Specifies how to deal with multiple devices being shared with a 9p export. 1455Supported behaviours are either "remap", "forbid" or "warn". The latter is 1456the default behaviour on which virtfs 9p expects only one device to be 1457shared with the same export, and if more than one device is shared and 1458accessed via the same 9p export then only a warning message is logged 1459(once) by qemu on host side. In order to avoid file ID collisions on guest 1460you should either create a separate virtfs export for each device to be 1461shared with guests (recommended way) or you might use "remap" instead which 1462allows you to share multiple devices with only one export instead, which is 1463achieved by remapping the original inode numbers from host to guest in a 1464way that would prevent such collisions. Remapping inodes in such use cases 1465is required because the original device IDs from host are never passed and 1466exposed on guest. Instead all files of an export shared with virtfs always 1467share the same device id on guest. So two files with identical inode 1468numbers but from actually different devices on host would otherwise cause a 1469file ID collision and hence potential misbehaviours on guest. "forbid" on 1470the other hand assumes like "warn" that only one device is shared by the 1471same export, however it will not only log a warning message but also 1472deny access to additional devices on guest. Note though that "forbid" does 1473currently not block all possible file access operations (e.g. readdir() 1474would still return entries from other devices). 1475@end table 1476ETEXI 1477 1478DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1479 "-iscsi [user=user][,password=password]\n" 1480 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1481 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1482 " [,timeout=timeout]\n" 1483 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1484 1485STEXI 1486@item -iscsi 1487@findex -iscsi 1488Configure iSCSI session parameters. 1489ETEXI 1490 1491STEXI 1492@end table 1493ETEXI 1494DEFHEADING() 1495 1496DEFHEADING(USB options:) 1497STEXI 1498@table @option 1499ETEXI 1500 1501DEF("usb", 0, QEMU_OPTION_usb, 1502 "-usb enable on-board USB host controller (if not enabled by default)\n", 1503 QEMU_ARCH_ALL) 1504STEXI 1505@item -usb 1506@findex -usb 1507Enable USB emulation on machine types with an on-board USB host controller (if 1508not enabled by default). Note that on-board USB host controllers may not 1509support USB 3.0. In this case @option{-device qemu-xhci} can be used instead 1510on machines with PCI. 1511ETEXI 1512 1513DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1514 "-usbdevice name add the host or guest USB device 'name'\n", 1515 QEMU_ARCH_ALL) 1516STEXI 1517 1518@item -usbdevice @var{devname} 1519@findex -usbdevice 1520Add the USB device @var{devname}. Note that this option is deprecated, 1521please use @code{-device usb-...} instead. @xref{usb_devices}. 1522 1523@table @option 1524 1525@item mouse 1526Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1527 1528@item tablet 1529Pointer device that uses absolute coordinates (like a touchscreen). This 1530means QEMU is able to report the mouse position without having to grab the 1531mouse. Also overrides the PS/2 mouse emulation when activated. 1532 1533@item braille 1534Braille device. This will use BrlAPI to display the braille output on a real 1535or fake device. 1536 1537@end table 1538ETEXI 1539 1540STEXI 1541@end table 1542ETEXI 1543DEFHEADING() 1544 1545DEFHEADING(Display options:) 1546STEXI 1547@table @option 1548ETEXI 1549 1550DEF("display", HAS_ARG, QEMU_OPTION_display, 1551#if defined(CONFIG_SPICE) 1552 "-display spice-app[,gl=on|off]\n" 1553#endif 1554#if defined(CONFIG_SDL) 1555 "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n" 1556 " [,window_close=on|off][,gl=on|core|es|off]\n" 1557#endif 1558#if defined(CONFIG_GTK) 1559 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1560#endif 1561#if defined(CONFIG_VNC) 1562 "-display vnc=<display>[,<optargs>]\n" 1563#endif 1564#if defined(CONFIG_CURSES) 1565 "-display curses[,charset=<encoding>]\n" 1566#endif 1567#if defined(CONFIG_OPENGL) 1568 "-display egl-headless[,rendernode=<file>]\n" 1569#endif 1570 "-display none\n" 1571 " select display backend type\n" 1572 " The default display is equivalent to\n " 1573#if defined(CONFIG_GTK) 1574 "\"-display gtk\"\n" 1575#elif defined(CONFIG_SDL) 1576 "\"-display sdl\"\n" 1577#elif defined(CONFIG_COCOA) 1578 "\"-display cocoa\"\n" 1579#elif defined(CONFIG_VNC) 1580 "\"-vnc localhost:0,to=99,id=default\"\n" 1581#else 1582 "\"-display none\"\n" 1583#endif 1584 , QEMU_ARCH_ALL) 1585STEXI 1586@item -display @var{type} 1587@findex -display 1588Select type of display to use. This option is a replacement for the 1589old style -sdl/-curses/... options. Valid values for @var{type} are 1590@table @option 1591@item sdl 1592Display video output via SDL (usually in a separate graphics 1593window; see the SDL documentation for other possibilities). 1594@item curses 1595Display video output via curses. For graphics device models which 1596support a text mode, QEMU can display this output using a 1597curses/ncurses interface. Nothing is displayed when the graphics 1598device is in graphical mode or if the graphics device does not support 1599a text mode. Generally only the VGA device models support text mode. 1600The font charset used by the guest can be specified with the 1601@code{charset} option, for example @code{charset=CP850} for IBM CP850 1602encoding. The default is @code{CP437}. 1603@item none 1604Do not display video output. The guest will still see an emulated 1605graphics card, but its output will not be displayed to the QEMU 1606user. This option differs from the -nographic option in that it 1607only affects what is done with video output; -nographic also changes 1608the destination of the serial and parallel port data. 1609@item gtk 1610Display video output in a GTK window. This interface provides drop-down 1611menus and other UI elements to configure and control the VM during 1612runtime. 1613@item vnc 1614Start a VNC server on display <arg> 1615@item egl-headless 1616Offload all OpenGL operations to a local DRI device. For any graphical display, 1617this display needs to be paired with either VNC or SPICE displays. 1618@item spice-app 1619Start QEMU as a Spice server and launch the default Spice client 1620application. The Spice server will redirect the serial consoles and 1621QEMU monitors. (Since 4.0) 1622@end table 1623ETEXI 1624 1625DEF("nographic", 0, QEMU_OPTION_nographic, 1626 "-nographic disable graphical output and redirect serial I/Os to console\n", 1627 QEMU_ARCH_ALL) 1628STEXI 1629@item -nographic 1630@findex -nographic 1631Normally, if QEMU is compiled with graphical window support, it displays 1632output such as guest graphics, guest console, and the QEMU monitor in a 1633window. With this option, you can totally disable graphical output so 1634that QEMU is a simple command line application. The emulated serial port 1635is redirected on the console and muxed with the monitor (unless 1636redirected elsewhere explicitly). Therefore, you can still use QEMU to 1637debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1638switching between the console and monitor. 1639ETEXI 1640 1641DEF("curses", 0, QEMU_OPTION_curses, 1642 "-curses shorthand for -display curses\n", 1643 QEMU_ARCH_ALL) 1644STEXI 1645@item -curses 1646@findex -curses 1647Normally, if QEMU is compiled with graphical window support, it displays 1648output such as guest graphics, guest console, and the QEMU monitor in a 1649window. With this option, QEMU can display the VGA output when in text 1650mode using a curses/ncurses interface. Nothing is displayed in graphical 1651mode. 1652ETEXI 1653 1654DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1655 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1656 QEMU_ARCH_ALL) 1657STEXI 1658@item -alt-grab 1659@findex -alt-grab 1660Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1661affects the special keys (for fullscreen, monitor-mode switching, etc). 1662ETEXI 1663 1664DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1665 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1666 QEMU_ARCH_ALL) 1667STEXI 1668@item -ctrl-grab 1669@findex -ctrl-grab 1670Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1671affects the special keys (for fullscreen, monitor-mode switching, etc). 1672ETEXI 1673 1674DEF("no-quit", 0, QEMU_OPTION_no_quit, 1675 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1676STEXI 1677@item -no-quit 1678@findex -no-quit 1679Disable SDL window close capability. 1680ETEXI 1681 1682DEF("sdl", 0, QEMU_OPTION_sdl, 1683 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1684STEXI 1685@item -sdl 1686@findex -sdl 1687Enable SDL. 1688ETEXI 1689 1690DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1691 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1692 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1693 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1694 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1695 " [,tls-ciphers=<list>]\n" 1696 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1697 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1698 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1699 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1700 " [,jpeg-wan-compression=[auto|never|always]]\n" 1701 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1702 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1703 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1704 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1705 " [,gl=[on|off]][,rendernode=<file>]\n" 1706 " enable spice\n" 1707 " at least one of {port, tls-port} is mandatory\n", 1708 QEMU_ARCH_ALL) 1709STEXI 1710@item -spice @var{option}[,@var{option}[,...]] 1711@findex -spice 1712Enable the spice remote desktop protocol. Valid options are 1713 1714@table @option 1715 1716@item port=<nr> 1717Set the TCP port spice is listening on for plaintext channels. 1718 1719@item addr=<addr> 1720Set the IP address spice is listening on. Default is any address. 1721 1722@item ipv4 1723@itemx ipv6 1724@itemx unix 1725Force using the specified IP version. 1726 1727@item password=<secret> 1728Set the password you need to authenticate. 1729 1730@item sasl 1731Require that the client use SASL to authenticate with the spice. 1732The exact choice of authentication method used is controlled from the 1733system / user's SASL configuration file for the 'qemu' service. This 1734is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1735unprivileged user, an environment variable SASL_CONF_PATH can be used 1736to make it search alternate locations for the service config. 1737While some SASL auth methods can also provide data encryption (eg GSSAPI), 1738it is recommended that SASL always be combined with the 'tls' and 1739'x509' settings to enable use of SSL and server certificates. This 1740ensures a data encryption preventing compromise of authentication 1741credentials. 1742 1743@item disable-ticketing 1744Allow client connects without authentication. 1745 1746@item disable-copy-paste 1747Disable copy paste between the client and the guest. 1748 1749@item disable-agent-file-xfer 1750Disable spice-vdagent based file-xfer between the client and the guest. 1751 1752@item tls-port=<nr> 1753Set the TCP port spice is listening on for encrypted channels. 1754 1755@item x509-dir=<dir> 1756Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1757 1758@item x509-key-file=<file> 1759@itemx x509-key-password=<file> 1760@itemx x509-cert-file=<file> 1761@itemx x509-cacert-file=<file> 1762@itemx x509-dh-key-file=<file> 1763The x509 file names can also be configured individually. 1764 1765@item tls-ciphers=<list> 1766Specify which ciphers to use. 1767 1768@item tls-channel=[main|display|cursor|inputs|record|playback] 1769@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1770Force specific channel to be used with or without TLS encryption. The 1771options can be specified multiple times to configure multiple 1772channels. The special name "default" can be used to set the default 1773mode. For channels which are not explicitly forced into one mode the 1774spice client is allowed to pick tls/plaintext as he pleases. 1775 1776@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1777Configure image compression (lossless). 1778Default is auto_glz. 1779 1780@item jpeg-wan-compression=[auto|never|always] 1781@itemx zlib-glz-wan-compression=[auto|never|always] 1782Configure wan image compression (lossy for slow links). 1783Default is auto. 1784 1785@item streaming-video=[off|all|filter] 1786Configure video stream detection. Default is off. 1787 1788@item agent-mouse=[on|off] 1789Enable/disable passing mouse events via vdagent. Default is on. 1790 1791@item playback-compression=[on|off] 1792Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1793 1794@item seamless-migration=[on|off] 1795Enable/disable spice seamless migration. Default is off. 1796 1797@item gl=[on|off] 1798Enable/disable OpenGL context. Default is off. 1799 1800@item rendernode=<file> 1801DRM render node for OpenGL rendering. If not specified, it will pick 1802the first available. (Since 2.9) 1803 1804@end table 1805ETEXI 1806 1807DEF("portrait", 0, QEMU_OPTION_portrait, 1808 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1809 QEMU_ARCH_ALL) 1810STEXI 1811@item -portrait 1812@findex -portrait 1813Rotate graphical output 90 deg left (only PXA LCD). 1814ETEXI 1815 1816DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1817 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1818 QEMU_ARCH_ALL) 1819STEXI 1820@item -rotate @var{deg} 1821@findex -rotate 1822Rotate graphical output some deg left (only PXA LCD). 1823ETEXI 1824 1825DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1826 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1827 " select video card type\n", QEMU_ARCH_ALL) 1828STEXI 1829@item -vga @var{type} 1830@findex -vga 1831Select type of VGA card to emulate. Valid values for @var{type} are 1832@table @option 1833@item cirrus 1834Cirrus Logic GD5446 Video card. All Windows versions starting from 1835Windows 95 should recognize and use this graphic card. For optimal 1836performances, use 16 bit color depth in the guest and the host OS. 1837(This card was the default before QEMU 2.2) 1838@item std 1839Standard VGA card with Bochs VBE extensions. If your guest OS 1840supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1841to use high resolution modes (>= 1280x1024x16) then you should use 1842this option. (This card is the default since QEMU 2.2) 1843@item vmware 1844VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1845recent XFree86/XOrg server or Windows guest with a driver for this 1846card. 1847@item qxl 1848QXL paravirtual graphic card. It is VGA compatible (including VESA 18492.0 VBE support). Works best with qxl guest drivers installed though. 1850Recommended choice when using the spice protocol. 1851@item tcx 1852(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1853sun4m machines and offers both 8-bit and 24-bit colour depths at a 1854fixed resolution of 1024x768. 1855@item cg3 1856(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1857for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1858resolutions aimed at people wishing to run older Solaris versions. 1859@item virtio 1860Virtio VGA card. 1861@item none 1862Disable VGA card. 1863@end table 1864ETEXI 1865 1866DEF("full-screen", 0, QEMU_OPTION_full_screen, 1867 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1868STEXI 1869@item -full-screen 1870@findex -full-screen 1871Start in full screen. 1872ETEXI 1873 1874DEF("g", 1, QEMU_OPTION_g , 1875 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1876 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K) 1877STEXI 1878@item -g @var{width}x@var{height}[x@var{depth}] 1879@findex -g 1880Set the initial graphical resolution and depth (PPC, SPARC only). 1881ETEXI 1882 1883DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1884 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1885STEXI 1886@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1887@findex -vnc 1888Normally, if QEMU is compiled with graphical window support, it displays 1889output such as guest graphics, guest console, and the QEMU monitor in a 1890window. With this option, you can have QEMU listen on VNC display 1891@var{display} and redirect the VGA display over the VNC session. It is 1892very useful to enable the usb tablet device when using this option 1893(option @option{-device usb-tablet}). When using the VNC display, you 1894must use the @option{-k} parameter to set the keyboard layout if you are 1895not using en-us. Valid syntax for the @var{display} is 1896 1897@table @option 1898 1899@item to=@var{L} 1900 1901With this option, QEMU will try next available VNC @var{display}s, until the 1902number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1903available, e.g. port 5900+@var{display} is already used by another 1904application. By default, to=0. 1905 1906@item @var{host}:@var{d} 1907 1908TCP connections will only be allowed from @var{host} on display @var{d}. 1909By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1910be omitted in which case the server will accept connections from any host. 1911 1912@item unix:@var{path} 1913 1914Connections will be allowed over UNIX domain sockets where @var{path} is the 1915location of a unix socket to listen for connections on. 1916 1917@item none 1918 1919VNC is initialized but not started. The monitor @code{change} command 1920can be used to later start the VNC server. 1921 1922@end table 1923 1924Following the @var{display} value there may be one or more @var{option} flags 1925separated by commas. Valid options are 1926 1927@table @option 1928 1929@item reverse 1930 1931Connect to a listening VNC client via a ``reverse'' connection. The 1932client is specified by the @var{display}. For reverse network 1933connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1934is a TCP port number, not a display number. 1935 1936@item websocket 1937 1938Opens an additional TCP listening port dedicated to VNC Websocket connections. 1939If a bare @var{websocket} option is given, the Websocket port is 19405700+@var{display}. An alternative port can be specified with the 1941syntax @code{websocket}=@var{port}. 1942 1943If @var{host} is specified connections will only be allowed from this host. 1944It is possible to control the websocket listen address independently, using 1945the syntax @code{websocket}=@var{host}:@var{port}. 1946 1947If no TLS credentials are provided, the websocket connection runs in 1948unencrypted mode. If TLS credentials are provided, the websocket connection 1949requires encrypted client connections. 1950 1951@item password 1952 1953Require that password based authentication is used for client connections. 1954 1955The password must be set separately using the @code{set_password} command in 1956the @ref{pcsys_monitor}. The syntax to change your password is: 1957@code{set_password <protocol> <password>} where <protocol> could be either 1958"vnc" or "spice". 1959 1960If you would like to change <protocol> password expiration, you should use 1961@code{expire_password <protocol> <expiration-time>} where expiration time could 1962be one of the following options: now, never, +seconds or UNIX time of 1963expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1964to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1965date and time). 1966 1967You can also use keywords "now" or "never" for the expiration time to 1968allow <protocol> password to expire immediately or never expire. 1969 1970@item tls-creds=@var{ID} 1971 1972Provides the ID of a set of TLS credentials to use to secure the 1973VNC server. They will apply to both the normal VNC server socket 1974and the websocket socket (if enabled). Setting TLS credentials 1975will cause the VNC server socket to enable the VeNCrypt auth 1976mechanism. The credentials should have been previously created 1977using the @option{-object tls-creds} argument. 1978 1979@item tls-authz=@var{ID} 1980 1981Provides the ID of the QAuthZ authorization object against which 1982the client's x509 distinguished name will validated. This object is 1983only resolved at time of use, so can be deleted and recreated on the 1984fly while the VNC server is active. If missing, it will default 1985to denying access. 1986 1987@item sasl 1988 1989Require that the client use SASL to authenticate with the VNC server. 1990The exact choice of authentication method used is controlled from the 1991system / user's SASL configuration file for the 'qemu' service. This 1992is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1993unprivileged user, an environment variable SASL_CONF_PATH can be used 1994to make it search alternate locations for the service config. 1995While some SASL auth methods can also provide data encryption (eg GSSAPI), 1996it is recommended that SASL always be combined with the 'tls' and 1997'x509' settings to enable use of SSL and server certificates. This 1998ensures a data encryption preventing compromise of authentication 1999credentials. See the @ref{vnc_security} section for details on using 2000SASL authentication. 2001 2002@item sasl-authz=@var{ID} 2003 2004Provides the ID of the QAuthZ authorization object against which 2005the client's SASL username will validated. This object is 2006only resolved at time of use, so can be deleted and recreated on the 2007fly while the VNC server is active. If missing, it will default 2008to denying access. 2009 2010@item acl 2011 2012Legacy method for enabling authorization of clients against the 2013x509 distinguished name and SASL username. It results in the creation 2014of two @code{authz-list} objects with IDs of @code{vnc.username} and 2015@code{vnc.x509dname}. The rules for these objects must be configured 2016with the HMP ACL commands. 2017 2018This option is deprecated and should no longer be used. The new 2019@option{sasl-authz} and @option{tls-authz} options are a 2020replacement. 2021 2022@item lossy 2023 2024Enable lossy compression methods (gradient, JPEG, ...). If this 2025option is set, VNC client may receive lossy framebuffer updates 2026depending on its encoding settings. Enabling this option can save 2027a lot of bandwidth at the expense of quality. 2028 2029@item non-adaptive 2030 2031Disable adaptive encodings. Adaptive encodings are enabled by default. 2032An adaptive encoding will try to detect frequently updated screen regions, 2033and send updates in these regions using a lossy encoding (like JPEG). 2034This can be really helpful to save bandwidth when playing videos. Disabling 2035adaptive encodings restores the original static behavior of encodings 2036like Tight. 2037 2038@item share=[allow-exclusive|force-shared|ignore] 2039 2040Set display sharing policy. 'allow-exclusive' allows clients to ask 2041for exclusive access. As suggested by the rfb spec this is 2042implemented by dropping other connections. Connecting multiple 2043clients in parallel requires all clients asking for a shared session 2044(vncviewer: -shared switch). This is the default. 'force-shared' 2045disables exclusive client access. Useful for shared desktop sessions, 2046where you don't want someone forgetting specify -shared disconnect 2047everybody else. 'ignore' completely ignores the shared flag and 2048allows everybody connect unconditionally. Doesn't conform to the rfb 2049spec but is traditional QEMU behavior. 2050 2051@item key-delay-ms 2052 2053Set keyboard delay, for key down and key up events, in milliseconds. 2054Default is 10. Keyboards are low-bandwidth devices, so this slowdown 2055can help the device and guest to keep up and not lose events in case 2056events are arriving in bulk. Possible causes for the latter are flaky 2057network connections, or scripts for automated testing. 2058 2059@item audiodev=@var{audiodev} 2060 2061Use the specified @var{audiodev} when the VNC client requests audio 2062transmission. When not using an -audiodev argument, this option must 2063be omitted, otherwise is must be present and specify a valid audiodev. 2064 2065@end table 2066ETEXI 2067 2068STEXI 2069@end table 2070ETEXI 2071ARCHHEADING(, QEMU_ARCH_I386) 2072 2073ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 2074STEXI 2075@table @option 2076ETEXI 2077 2078DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 2079 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 2080 QEMU_ARCH_I386) 2081STEXI 2082@item -win2k-hack 2083@findex -win2k-hack 2084Use it when installing Windows 2000 to avoid a disk full bug. After 2085Windows 2000 is installed, you no longer need this option (this option 2086slows down the IDE transfers). 2087ETEXI 2088 2089DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 2090 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 2091 QEMU_ARCH_I386) 2092STEXI 2093@item -no-fd-bootchk 2094@findex -no-fd-bootchk 2095Disable boot signature checking for floppy disks in BIOS. May 2096be needed to boot from old floppy disks. 2097ETEXI 2098 2099DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 2100 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2101STEXI 2102@item -no-acpi 2103@findex -no-acpi 2104Disable ACPI (Advanced Configuration and Power Interface) support. Use 2105it if your guest OS complains about ACPI problems (PC target machine 2106only). 2107ETEXI 2108 2109DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 2110 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 2111STEXI 2112@item -no-hpet 2113@findex -no-hpet 2114Disable HPET support. 2115ETEXI 2116 2117DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 2118 "-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" 2119 " ACPI table description\n", QEMU_ARCH_I386) 2120STEXI 2121@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}]...] 2122@findex -acpitable 2123Add ACPI table with specified header fields and context from specified files. 2124For file=, take whole ACPI table from the specified files, including all 2125ACPI headers (possible overridden by other options). 2126For data=, only data 2127portion of the table is used, all header information is specified in the 2128command line. 2129If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 2130fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 2131to ensure the field matches required by the Microsoft SLIC spec and the ACPI 2132spec. 2133ETEXI 2134 2135DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 2136 "-smbios file=binary\n" 2137 " load SMBIOS entry from binary file\n" 2138 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 2139 " [,uefi=on|off]\n" 2140 " specify SMBIOS type 0 fields\n" 2141 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2142 " [,uuid=uuid][,sku=str][,family=str]\n" 2143 " specify SMBIOS type 1 fields\n" 2144 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 2145 " [,asset=str][,location=str]\n" 2146 " specify SMBIOS type 2 fields\n" 2147 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 2148 " [,sku=str]\n" 2149 " specify SMBIOS type 3 fields\n" 2150 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 2151 " [,asset=str][,part=str]\n" 2152 " specify SMBIOS type 4 fields\n" 2153 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 2154 " [,asset=str][,part=str][,speed=%d]\n" 2155 " specify SMBIOS type 17 fields\n", 2156 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 2157STEXI 2158@item -smbios file=@var{binary} 2159@findex -smbios 2160Load SMBIOS entry from binary file. 2161 2162@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 2163Specify SMBIOS type 0 fields 2164 2165@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}] 2166Specify SMBIOS type 1 fields 2167 2168@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}] 2169Specify SMBIOS type 2 fields 2170 2171@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 2172Specify SMBIOS type 3 fields 2173 2174@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 2175Specify SMBIOS type 4 fields 2176 2177@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}] 2178Specify SMBIOS type 17 fields 2179ETEXI 2180 2181STEXI 2182@end table 2183ETEXI 2184DEFHEADING() 2185 2186DEFHEADING(Network options:) 2187STEXI 2188@table @option 2189ETEXI 2190 2191DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 2192#ifdef CONFIG_SLIRP 2193 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 2194 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 2195 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 2196 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 2197 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 2198#ifndef _WIN32 2199 "[,smb=dir[,smbserver=addr]]\n" 2200#endif 2201 " configure a user mode network backend with ID 'str',\n" 2202 " its DHCP server and optional services\n" 2203#endif 2204#ifdef _WIN32 2205 "-netdev tap,id=str,ifname=name\n" 2206 " configure a host TAP network backend with ID 'str'\n" 2207#else 2208 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 2209 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 2210 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 2211 " [,poll-us=n]\n" 2212 " configure a host TAP network backend with ID 'str'\n" 2213 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2214 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 2215 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 2216 " to deconfigure it\n" 2217 " use '[down]script=no' to disable script execution\n" 2218 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 2219 " configure it\n" 2220 " use 'fd=h' to connect to an already opened TAP interface\n" 2221 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 2222 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 2223 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 2224 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 2225 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 2226 " use vhost=on to enable experimental in kernel accelerator\n" 2227 " (only has effect for virtio guests which use MSIX)\n" 2228 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 2229 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 2230 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 2231 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 2232 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 2233 " spent on busy polling for vhost net\n" 2234 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 2235 " configure a host TAP network backend with ID 'str' that is\n" 2236 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 2237 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 2238#endif 2239#ifdef __linux__ 2240 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 2241 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 2242 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 2243 " [,rxcookie=rxcookie][,offset=offset]\n" 2244 " configure a network backend with ID 'str' connected to\n" 2245 " an Ethernet over L2TPv3 pseudowire.\n" 2246 " Linux kernel 3.3+ as well as most routers can talk\n" 2247 " L2TPv3. This transport allows connecting a VM to a VM,\n" 2248 " VM to a router and even VM to Host. It is a nearly-universal\n" 2249 " standard (RFC3391). Note - this implementation uses static\n" 2250 " pre-configured tunnels (same as the Linux kernel).\n" 2251 " use 'src=' to specify source address\n" 2252 " use 'dst=' to specify destination address\n" 2253 " use 'udp=on' to specify udp encapsulation\n" 2254 " use 'srcport=' to specify source udp port\n" 2255 " use 'dstport=' to specify destination udp port\n" 2256 " use 'ipv6=on' to force v6\n" 2257 " L2TPv3 uses cookies to prevent misconfiguration as\n" 2258 " well as a weak security measure\n" 2259 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 2260 " use 'txcookie=0x012345678' to specify a txcookie\n" 2261 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 2262 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 2263 " use 'pincounter=on' to work around broken counter handling in peer\n" 2264 " use 'offset=X' to add an extra offset between header and data\n" 2265#endif 2266 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 2267 " configure a network backend to connect to another network\n" 2268 " using a socket connection\n" 2269 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 2270 " configure a network backend to connect to a multicast maddr and port\n" 2271 " use 'localaddr=addr' to specify the host address to send packets from\n" 2272 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 2273 " configure a network backend to connect to another network\n" 2274 " using an UDP tunnel\n" 2275#ifdef CONFIG_VDE 2276 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 2277 " configure a network backend to connect to port 'n' of a vde switch\n" 2278 " running on host and listening for incoming connections on 'socketpath'.\n" 2279 " Use group 'groupname' and mode 'octalmode' to change default\n" 2280 " ownership and permissions for communication port.\n" 2281#endif 2282#ifdef CONFIG_NETMAP 2283 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 2284 " attach to the existing netmap-enabled network interface 'name', or to a\n" 2285 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 2286 " netmap device, defaults to '/dev/netmap')\n" 2287#endif 2288#ifdef CONFIG_POSIX 2289 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 2290 " configure a vhost-user network, backed by a chardev 'dev'\n" 2291#endif 2292 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 2293 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 2294DEF("nic", HAS_ARG, QEMU_OPTION_nic, 2295 "-nic [tap|bridge|" 2296#ifdef CONFIG_SLIRP 2297 "user|" 2298#endif 2299#ifdef __linux__ 2300 "l2tpv3|" 2301#endif 2302#ifdef CONFIG_VDE 2303 "vde|" 2304#endif 2305#ifdef CONFIG_NETMAP 2306 "netmap|" 2307#endif 2308#ifdef CONFIG_POSIX 2309 "vhost-user|" 2310#endif 2311 "socket][,option][,...][mac=macaddr]\n" 2312 " initialize an on-board / default host NIC (using MAC address\n" 2313 " macaddr) and connect it to the given host network backend\n" 2314 "-nic none use it alone to have zero network devices (the default is to\n" 2315 " provided a 'user' network connection)\n", 2316 QEMU_ARCH_ALL) 2317DEF("net", HAS_ARG, QEMU_OPTION_net, 2318 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2319 " configure or create an on-board (or machine default) NIC and\n" 2320 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2321 "-net [" 2322#ifdef CONFIG_SLIRP 2323 "user|" 2324#endif 2325 "tap|" 2326 "bridge|" 2327#ifdef CONFIG_VDE 2328 "vde|" 2329#endif 2330#ifdef CONFIG_NETMAP 2331 "netmap|" 2332#endif 2333 "socket][,option][,option][,...]\n" 2334 " old way to initialize a host network interface\n" 2335 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2336STEXI 2337@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2338@findex -nic 2339This option is a shortcut for configuring both the on-board (default) guest 2340NIC hardware and the host network backend in one go. The host backend options 2341are the same as with the corresponding @option{-netdev} options below. 2342The guest NIC model can be set with @option{model=@var{modelname}}. 2343Use @option{model=help} to list the available device types. 2344The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2345 2346The following two example do exactly the same, to show how @option{-nic} can 2347be used to shorten the command line length (note that the e1000 is the default 2348on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2349@example 2350@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2351@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2352@end example 2353 2354@item -nic none 2355Indicate that no network devices should be configured. It is used to override 2356the default configuration (default NIC with ``user'' host network backend) 2357which is activated if no other networking options are provided. 2358 2359@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2360@findex -netdev 2361Configure user mode host network backend which requires no administrator 2362privilege to run. Valid options are: 2363 2364@table @option 2365@item id=@var{id} 2366Assign symbolic name for use in monitor commands. 2367 2368@item ipv4=on|off and ipv6=on|off 2369Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2370both protocols are enabled. 2371 2372@item net=@var{addr}[/@var{mask}] 2373Set IP network address the guest will see. Optionally specify the netmask, 2374either in the form a.b.c.d or as number of valid top-most bits. Default is 237510.0.2.0/24. 2376 2377@item host=@var{addr} 2378Specify the guest-visible address of the host. Default is the 2nd IP in the 2379guest network, i.e. x.x.x.2. 2380 2381@item ipv6-net=@var{addr}[/@var{int}] 2382Set IPv6 network address the guest will see (default is fec0::/64). The 2383network prefix is given in the usual hexadecimal IPv6 address 2384notation. The prefix size is optional, and is given as the number of 2385valid top-most bits (default is 64). 2386 2387@item ipv6-host=@var{addr} 2388Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2389the guest network, i.e. xxxx::2. 2390 2391@item restrict=on|off 2392If this option is enabled, the guest will be isolated, i.e. it will not be 2393able to contact the host and no guest IP packets will be routed over the host 2394to the outside. This option does not affect any explicitly set forwarding rules. 2395 2396@item hostname=@var{name} 2397Specifies the client hostname reported by the built-in DHCP server. 2398 2399@item dhcpstart=@var{addr} 2400Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2401is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2402 2403@item dns=@var{addr} 2404Specify the guest-visible address of the virtual nameserver. The address must 2405be different from the host address. Default is the 3rd IP in the guest network, 2406i.e. x.x.x.3. 2407 2408@item ipv6-dns=@var{addr} 2409Specify the guest-visible address of the IPv6 virtual nameserver. The address 2410must be different from the host address. Default is the 3rd IP in the guest 2411network, i.e. xxxx::3. 2412 2413@item dnssearch=@var{domain} 2414Provides an entry for the domain-search list sent by the built-in 2415DHCP server. More than one domain suffix can be transmitted by specifying 2416this option multiple times. If supported, this will cause the guest to 2417automatically try to append the given domain suffix(es) in case a domain name 2418can not be resolved. 2419 2420Example: 2421@example 2422@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2423@end example 2424 2425@item domainname=@var{domain} 2426Specifies the client domain name reported by the built-in DHCP server. 2427 2428@item tftp=@var{dir} 2429When using the user mode network stack, activate a built-in TFTP 2430server. The files in @var{dir} will be exposed as the root of a TFTP server. 2431The TFTP client on the guest must be configured in binary mode (use the command 2432@code{bin} of the Unix TFTP client). 2433 2434@item tftp-server-name=@var{name} 2435In BOOTP reply, broadcast @var{name} as the "TFTP server name" (RFC2132 option 243666). This can be used to advise the guest to load boot files or configurations 2437from a different server than the host address. 2438 2439@item bootfile=@var{file} 2440When using the user mode network stack, broadcast @var{file} as the BOOTP 2441filename. In conjunction with @option{tftp}, this can be used to network boot 2442a guest from a local directory. 2443 2444Example (using pxelinux): 2445@example 2446@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \ 2447 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2448@end example 2449 2450@item smb=@var{dir}[,smbserver=@var{addr}] 2451When using the user mode network stack, activate a built-in SMB 2452server so that Windows OSes can access to the host files in @file{@var{dir}} 2453transparently. The IP address of the SMB server can be set to @var{addr}. By 2454default the 4th IP in the guest network is used, i.e. x.x.x.4. 2455 2456In the guest Windows OS, the line: 2457@example 245810.0.2.4 smbserver 2459@end example 2460must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2461or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2462 2463Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2464 2465Note that a SAMBA server must be installed on the host OS. 2466 2467@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2468Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2469the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2470@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2471given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2472be bound to a specific host interface. If no connection type is set, TCP is 2473used. This option can be given multiple times. 2474 2475For example, to redirect host X11 connection from screen 1 to guest 2476screen 0, use the following: 2477 2478@example 2479# on the host 2480@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2481# this host xterm should open in the guest X11 server 2482xterm -display :1 2483@end example 2484 2485To redirect telnet connections from host port 5555 to telnet port on 2486the guest, use the following: 2487 2488@example 2489# on the host 2490@value{qemu_system} -nic user,hostfwd=tcp::5555-:23 2491telnet localhost 5555 2492@end example 2493 2494Then when you use on the host @code{telnet localhost 5555}, you 2495connect to the guest telnet server. 2496 2497@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2498@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2499Forward guest TCP connections to the IP address @var{server} on port @var{port} 2500to the character device @var{dev} or to a program executed by @var{cmd:command} 2501which gets spawned for each connection. This option can be given multiple times. 2502 2503You can either use a chardev directly and have that one used throughout QEMU's 2504lifetime, like in the following example: 2505 2506@example 2507# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2508# the guest accesses it 2509@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2510@end example 2511 2512Or you can execute a command on every TCP connection established by the guest, 2513so that QEMU behaves similar to an inetd process for that virtual server: 2514 2515@example 2516# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2517# and connect the TCP stream to its stdin/stdout 2518@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2519@end example 2520 2521@end table 2522 2523@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2524Configure a host TAP network backend with ID @var{id}. 2525 2526Use the network script @var{file} to configure it and the network script 2527@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2528automatically provides one. The default network configure script is 2529@file{/etc/qemu-ifup} and the default network deconfigure script is 2530@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2531to disable script execution. 2532 2533If running QEMU as an unprivileged user, use the network helper 2534@var{helper} to configure the TAP interface and attach it to the bridge. 2535The default network helper executable is @file{/path/to/qemu-bridge-helper} 2536and the default bridge device is @file{br0}. 2537 2538@option{fd}=@var{h} can be used to specify the handle of an already 2539opened host TAP interface. 2540 2541Examples: 2542 2543@example 2544#launch a QEMU instance with the default network script 2545@value{qemu_system} linux.img -nic tap 2546@end example 2547 2548@example 2549#launch a QEMU instance with two NICs, each one connected 2550#to a TAP device 2551@value{qemu_system} linux.img \ 2552 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2553 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2554@end example 2555 2556@example 2557#launch a QEMU instance with the default network helper to 2558#connect a TAP device to bridge br0 2559@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \ 2560 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2561@end example 2562 2563@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2564Connect a host TAP network interface to a host bridge device. 2565 2566Use the network helper @var{helper} to configure the TAP interface and 2567attach it to the bridge. The default network helper executable is 2568@file{/path/to/qemu-bridge-helper} and the default bridge 2569device is @file{br0}. 2570 2571Examples: 2572 2573@example 2574#launch a QEMU instance with the default network helper to 2575#connect a TAP device to bridge br0 2576@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2577@end example 2578 2579@example 2580#launch a QEMU instance with the default network helper to 2581#connect a TAP device to bridge qemubr0 2582@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2583@end example 2584 2585@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2586 2587This host network backend can be used to connect the guest's network to 2588another QEMU virtual machine using a TCP socket connection. If @option{listen} 2589is specified, QEMU waits for incoming connections on @var{port} 2590(@var{host} is optional). @option{connect} is used to connect to 2591another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2592specifies an already opened TCP socket. 2593 2594Example: 2595@example 2596# launch a first QEMU instance 2597@value{qemu_system} linux.img \ 2598 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2599 -netdev socket,id=n1,listen=:1234 2600# connect the network of this instance to the network of the first instance 2601@value{qemu_system} linux.img \ 2602 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2603 -netdev socket,id=n2,connect=127.0.0.1:1234 2604@end example 2605 2606@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2607 2608Configure a socket host network backend to share the guest's network traffic 2609with another QEMU virtual machines using a UDP multicast socket, effectively 2610making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2611NOTES: 2612@enumerate 2613@item 2614Several QEMU can be running on different hosts and share same bus (assuming 2615correct multicast setup for these hosts). 2616@item 2617mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2618@url{http://user-mode-linux.sf.net}. 2619@item 2620Use @option{fd=h} to specify an already opened UDP multicast socket. 2621@end enumerate 2622 2623Example: 2624@example 2625# launch one QEMU instance 2626@value{qemu_system} linux.img \ 2627 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2628 -netdev socket,id=n1,mcast=230.0.0.1:1234 2629# launch another QEMU instance on same "bus" 2630@value{qemu_system} linux.img \ 2631 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2632 -netdev socket,id=n2,mcast=230.0.0.1:1234 2633# launch yet another QEMU instance on same "bus" 2634@value{qemu_system} linux.img \ 2635 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \ 2636 -netdev socket,id=n3,mcast=230.0.0.1:1234 2637@end example 2638 2639Example (User Mode Linux compat.): 2640@example 2641# launch QEMU instance (note mcast address selected is UML's default) 2642@value{qemu_system} linux.img \ 2643 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2644 -netdev socket,id=n1,mcast=239.192.168.1:1102 2645# launch UML 2646/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2647@end example 2648 2649Example (send packets from host's 1.2.3.4): 2650@example 2651@value{qemu_system} linux.img \ 2652 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2653 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2654@end example 2655 2656@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}] 2657Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2658popular protocol to transport Ethernet (and other Layer 2) data frames between 2659two systems. It is present in routers, firewalls and the Linux kernel 2660(from version 3.3 onwards). 2661 2662This transport allows a VM to communicate to another VM, router or firewall directly. 2663 2664@table @option 2665@item src=@var{srcaddr} 2666 source address (mandatory) 2667@item dst=@var{dstaddr} 2668 destination address (mandatory) 2669@item udp 2670 select udp encapsulation (default is ip). 2671@item srcport=@var{srcport} 2672 source udp port. 2673@item dstport=@var{dstport} 2674 destination udp port. 2675@item ipv6 2676 force v6, otherwise defaults to v4. 2677@item rxcookie=@var{rxcookie} 2678@itemx txcookie=@var{txcookie} 2679 Cookies are a weak form of security in the l2tpv3 specification. 2680Their function is mostly to prevent misconfiguration. By default they are 32 2681bit. 2682@item cookie64 2683 Set cookie size to 64 bit instead of the default 32 2684@item counter=off 2685 Force a 'cut-down' L2TPv3 with no counter as in 2686draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2687@item pincounter=on 2688 Work around broken counter handling in peer. This may also help on 2689networks which have packet reorder. 2690@item offset=@var{offset} 2691 Add an extra offset between header and data 2692@end table 2693 2694For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2695on the remote Linux host 1.2.3.4: 2696@example 2697# Setup tunnel on linux host using raw ip as encapsulation 2698# on 1.2.3.4 2699ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2700 encap udp udp_sport 16384 udp_dport 16384 2701ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2702 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2703ifconfig vmtunnel0 mtu 1500 2704ifconfig vmtunnel0 up 2705brctl addif br-lan vmtunnel0 2706 2707 2708# on 4.3.2.1 2709# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2710 2711@value{qemu_system} linux.img -device e1000,netdev=n1 \ 2712 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2713 2714@end example 2715 2716@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2717Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2718listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2719and MODE @var{octalmode} to change default ownership and permissions for 2720communication port. This option is only available if QEMU has been compiled 2721with vde support enabled. 2722 2723Example: 2724@example 2725# launch vde switch 2726vde_switch -F -sock /tmp/myswitch 2727# launch QEMU instance 2728@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch 2729@end example 2730 2731@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2732 2733Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2734be a unix domain socket backed one. The vhost-user uses a specifically defined 2735protocol to pass vhost ioctl replacement messages to an application on the other 2736end of the socket. On non-MSIX guests, the feature can be forced with 2737@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2738be created for multiqueue vhost-user. 2739 2740Example: 2741@example 2742qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2743 -numa node,memdev=mem \ 2744 -chardev socket,id=chr0,path=/path/to/socket \ 2745 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2746 -device virtio-net-pci,netdev=net0 2747@end example 2748 2749@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2750 2751Create a hub port on the emulated hub with ID @var{hubid}. 2752 2753The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2754single netdev. Alternatively, you can also connect the hubport to another 2755netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2756 2757@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2758@findex -net 2759Legacy option to configure or create an on-board (or machine default) Network 2760Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2761the default hub), or to the netdev @var{nd}. 2762The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2763can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2764only), and a @var{name} can be assigned for use in monitor commands. 2765Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2766that the card should have; this option currently only affects virtio cards; set 2767@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2768NIC is created. QEMU can emulate several different models of network card. 2769Use @code{-net nic,model=help} for a list of available devices for your target. 2770 2771@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2772Configure a host network backend (with the options corresponding to the same 2773@option{-netdev} option) and connect it to the emulated hub 0 (the default 2774hub). Use @var{name} to specify the name of the hub port. 2775ETEXI 2776 2777STEXI 2778@end table 2779ETEXI 2780DEFHEADING() 2781 2782DEFHEADING(Character device options:) 2783 2784DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2785 "-chardev help\n" 2786 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2787 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2788 " [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n" 2789 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" 2790 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n" 2791 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2792 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2793 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2794 " [,logfile=PATH][,logappend=on|off]\n" 2795 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2796 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2797 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2798 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2799 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2800 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2801#ifdef _WIN32 2802 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2803 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2804#else 2805 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2806 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2807#endif 2808#ifdef CONFIG_BRLAPI 2809 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2810#endif 2811#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2812 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2813 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2814 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2815#endif 2816#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2817 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2818 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2819#endif 2820#if defined(CONFIG_SPICE) 2821 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2822 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2823#endif 2824 , QEMU_ARCH_ALL 2825) 2826 2827STEXI 2828 2829The general form of a character device option is: 2830@table @option 2831@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2832@findex -chardev 2833Backend is one of: 2834@option{null}, 2835@option{socket}, 2836@option{udp}, 2837@option{msmouse}, 2838@option{vc}, 2839@option{ringbuf}, 2840@option{file}, 2841@option{pipe}, 2842@option{console}, 2843@option{serial}, 2844@option{pty}, 2845@option{stdio}, 2846@option{braille}, 2847@option{tty}, 2848@option{parallel}, 2849@option{parport}, 2850@option{spicevmc}, 2851@option{spiceport}. 2852The specific backend will determine the applicable options. 2853 2854Use @code{-chardev help} to print all available chardev backend types. 2855 2856All devices must have an id, which can be any string up to 127 characters long. 2857It is used to uniquely identify this device in other command line directives. 2858 2859A character device may be used in multiplexing mode by multiple front-ends. 2860Specify @option{mux=on} to enable this mode. 2861A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2862backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2863If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2864create a multiplexer with your specified ID, and you can then configure multiple 2865front ends to use that chardev ID for their input/output. Up to four different 2866front ends can be connected to a single multiplexed chardev. (Without 2867multiplexing enabled, a chardev can only be used by a single front end.) 2868For instance you could use this to allow a single stdio chardev to be used by 2869two serial ports and the QEMU monitor: 2870 2871@example 2872-chardev stdio,mux=on,id=char0 \ 2873-mon chardev=char0,mode=readline \ 2874-serial chardev:char0 \ 2875-serial chardev:char0 2876@end example 2877 2878You can have more than one multiplexer in a system configuration; for instance 2879you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2880multiplexed between the QEMU monitor and a parallel port: 2881 2882@example 2883-chardev stdio,mux=on,id=char0 \ 2884-mon chardev=char0,mode=readline \ 2885-parallel chardev:char0 \ 2886-chardev tcp,...,mux=on,id=char1 \ 2887-serial chardev:char1 \ 2888-serial chardev:char1 2889@end example 2890 2891When you're using a multiplexed character device, some escape sequences are 2892interpreted in the input. @xref{mux_keys, Keys in the character backend 2893multiplexer}. 2894 2895Note that some other command line options may implicitly create multiplexed 2896character backends; for instance @option{-serial mon:stdio} creates a 2897multiplexed stdio backend connected to the serial port and the QEMU monitor, 2898and @option{-nographic} also multiplexes the console and the monitor to 2899stdio. 2900 2901There is currently no support for multiplexing in the other direction 2902(where a single QEMU front end takes input and output from multiple chardevs). 2903 2904Every backend supports the @option{logfile} option, which supplies the path 2905to a file to record all data transmitted via the backend. The @option{logappend} 2906option controls whether the log file will be truncated or appended to when 2907opened. 2908 2909@end table 2910 2911The available backends are: 2912 2913@table @option 2914@item -chardev null,id=@var{id} 2915A void device. This device will not emit any data, and will drop any data it 2916receives. The null backend does not take any options. 2917 2918@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}] 2919 2920Create a two-way stream socket, which can be either a TCP or a unix socket. A 2921unix socket will be created if @option{path} is specified. Behaviour is 2922undefined if TCP options are specified for a unix socket. 2923 2924@option{server} specifies that the socket shall be a listening socket. 2925 2926@option{nowait} specifies that QEMU should not block waiting for a client to 2927connect to a listening socket. 2928 2929@option{telnet} specifies that traffic on the socket should interpret telnet 2930escape sequences. 2931 2932@option{websocket} specifies that the socket uses WebSocket protocol for 2933communication. 2934 2935@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2936the remote end goes away. qemu will delay this many seconds and then attempt 2937to reconnect. Zero disables reconnecting, and is the default. 2938 2939@option{tls-creds} requests enablement of the TLS protocol for encryption, 2940and specifies the id of the TLS credentials to use for the handshake. The 2941credentials must be previously created with the @option{-object tls-creds} 2942argument. 2943 2944@option{tls-auth} provides the ID of the QAuthZ authorization object against 2945which the client's x509 distinguished name will be validated. This object is 2946only resolved at time of use, so can be deleted and recreated on the fly 2947while the chardev server is active. If missing, it will default to denying 2948access. 2949 2950TCP and unix socket options are given below: 2951 2952@table @option 2953 2954@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2955 2956@option{host} for a listening socket specifies the local address to be bound. 2957For a connecting socket species the remote host to connect to. @option{host} is 2958optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2959 2960@option{port} for a listening socket specifies the local port to be bound. For a 2961connecting socket specifies the port on the remote host to connect to. 2962@option{port} can be given as either a port number or a service name. 2963@option{port} is required. 2964 2965@option{to} is only relevant to listening sockets. If it is specified, and 2966@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2967to and including @option{to} until it succeeds. @option{to} must be specified 2968as a port number. 2969 2970@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2971If neither is specified the socket may use either protocol. 2972 2973@option{nodelay} disables the Nagle algorithm. 2974 2975@item unix options: path=@var{path} 2976 2977@option{path} specifies the local path of the unix socket. @option{path} is 2978required. 2979 2980@end table 2981 2982@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2983 2984Sends all traffic from the guest to a remote host over UDP. 2985 2986@option{host} specifies the remote host to connect to. If not specified it 2987defaults to @code{localhost}. 2988 2989@option{port} specifies the port on the remote host to connect to. @option{port} 2990is required. 2991 2992@option{localaddr} specifies the local address to bind to. If not specified it 2993defaults to @code{0.0.0.0}. 2994 2995@option{localport} specifies the local port to bind to. If not specified any 2996available local port will be used. 2997 2998@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2999If neither is specified the device may use either protocol. 3000 3001@item -chardev msmouse,id=@var{id} 3002 3003Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 3004take any options. 3005 3006@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 3007 3008Connect to a QEMU text console. @option{vc} may optionally be given a specific 3009size. 3010 3011@option{width} and @option{height} specify the width and height respectively of 3012the console, in pixels. 3013 3014@option{cols} and @option{rows} specify that the console be sized to fit a text 3015console with the given dimensions. 3016 3017@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 3018 3019Create a ring buffer with fixed size @option{size}. 3020@var{size} must be a power of two and defaults to @code{64K}. 3021 3022@item -chardev file,id=@var{id},path=@var{path} 3023 3024Log all traffic received from the guest to a file. 3025 3026@option{path} specifies the path of the file to be opened. This file will be 3027created if it does not already exist, and overwritten if it does. @option{path} 3028is required. 3029 3030@item -chardev pipe,id=@var{id},path=@var{path} 3031 3032Create a two-way connection to the guest. The behaviour differs slightly between 3033Windows hosts and other hosts: 3034 3035On Windows, a single duplex pipe will be created at 3036@file{\\.pipe\@option{path}}. 3037 3038On other hosts, 2 pipes will be created called @file{@option{path}.in} and 3039@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 3040received by the guest. Data written by the guest can be read from 3041@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 3042be present. 3043 3044@option{path} forms part of the pipe path as described above. @option{path} is 3045required. 3046 3047@item -chardev console,id=@var{id} 3048 3049Send traffic from the guest to QEMU's standard output. @option{console} does not 3050take any options. 3051 3052@option{console} is only available on Windows hosts. 3053 3054@item -chardev serial,id=@var{id},path=@option{path} 3055 3056Send traffic from the guest to a serial device on the host. 3057 3058On Unix hosts serial will actually accept any tty device, 3059not only serial lines. 3060 3061@option{path} specifies the name of the serial device to open. 3062 3063@item -chardev pty,id=@var{id} 3064 3065Create a new pseudo-terminal on the host and connect to it. @option{pty} does 3066not take any options. 3067 3068@option{pty} is not available on Windows hosts. 3069 3070@item -chardev stdio,id=@var{id}[,signal=on|off] 3071Connect to standard input and standard output of the QEMU process. 3072 3073@option{signal} controls if signals are enabled on the terminal, that includes 3074exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 3075default, use @option{signal=off} to disable it. 3076 3077@item -chardev braille,id=@var{id} 3078 3079Connect to a local BrlAPI server. @option{braille} does not take any options. 3080 3081@item -chardev tty,id=@var{id},path=@var{path} 3082 3083@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 3084DragonFlyBSD hosts. It is an alias for @option{serial}. 3085 3086@option{path} specifies the path to the tty. @option{path} is required. 3087 3088@item -chardev parallel,id=@var{id},path=@var{path} 3089@itemx -chardev parport,id=@var{id},path=@var{path} 3090 3091@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 3092 3093Connect to a local parallel port. 3094 3095@option{path} specifies the path to the parallel port device. @option{path} is 3096required. 3097 3098@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 3099 3100@option{spicevmc} is only available when spice support is built in. 3101 3102@option{debug} debug level for spicevmc 3103 3104@option{name} name of spice channel to connect to 3105 3106Connect to a spice virtual machine channel, such as vdiport. 3107 3108@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 3109 3110@option{spiceport} is only available when spice support is built in. 3111 3112@option{debug} debug level for spicevmc 3113 3114@option{name} name of spice port to connect to 3115 3116Connect to a spice port, allowing a Spice client to handle the traffic 3117identified by a name (preferably a fqdn). 3118ETEXI 3119 3120STEXI 3121@end table 3122ETEXI 3123DEFHEADING() 3124 3125#ifdef CONFIG_TPM 3126DEFHEADING(TPM device options:) 3127 3128DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3129 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3130 " use path to provide path to a character device; default is /dev/tpm0\n" 3131 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3132 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 3133 "-tpmdev emulator,id=id,chardev=dev\n" 3134 " configure the TPM device using chardev backend\n", 3135 QEMU_ARCH_ALL) 3136STEXI 3137 3138The general form of a TPM device option is: 3139@table @option 3140 3141@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 3142@findex -tpmdev 3143 3144The specific backend type will determine the applicable options. 3145The @code{-tpmdev} option creates the TPM backend and requires a 3146@code{-device} option that specifies the TPM frontend interface model. 3147 3148Use @code{-tpmdev help} to print all available TPM backend types. 3149 3150@end table 3151 3152The available backends are: 3153 3154@table @option 3155 3156@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 3157 3158(Linux-host only) Enable access to the host's TPM using the passthrough 3159driver. 3160 3161@option{path} specifies the path to the host's TPM device, i.e., on 3162a Linux host this would be @code{/dev/tpm0}. 3163@option{path} is optional and by default @code{/dev/tpm0} is used. 3164 3165@option{cancel-path} specifies the path to the host TPM device's sysfs 3166entry allowing for cancellation of an ongoing TPM command. 3167@option{cancel-path} is optional and by default QEMU will search for the 3168sysfs entry to use. 3169 3170Some notes about using the host's TPM with the passthrough driver: 3171 3172The TPM device accessed by the passthrough driver must not be 3173used by any other application on the host. 3174 3175Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3176the VM's firmware (BIOS/UEFI) will not be able to initialize the 3177TPM again and may therefore not show a TPM-specific menu that would 3178otherwise allow the user to configure the TPM, e.g., allow the user to 3179enable/disable or activate/deactivate the TPM. 3180Further, if TPM ownership is released from within a VM then the host's TPM 3181will get disabled and deactivated. To enable and activate the 3182TPM again afterwards, the host has to be rebooted and the user is 3183required to enter the firmware's menu to enable and activate the TPM. 3184If the TPM is left disabled and/or deactivated most TPM commands will fail. 3185 3186To create a passthrough TPM use the following two options: 3187@example 3188-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3189@end example 3190Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3191@code{tpmdev=tpm0} in the device option. 3192 3193@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 3194 3195(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 3196chardev backend. 3197 3198@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 3199 3200To create a TPM emulator backend device with chardev socket backend: 3201@example 3202 3203-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 3204 3205@end example 3206 3207ETEXI 3208 3209STEXI 3210@end table 3211ETEXI 3212DEFHEADING() 3213 3214#endif 3215 3216DEFHEADING(Linux/Multiboot boot specific:) 3217STEXI 3218 3219When using these options, you can use a given Linux or Multiboot 3220kernel without installing it in the disk image. It can be useful 3221for easier testing of various kernels. 3222 3223@table @option 3224ETEXI 3225 3226DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3227 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3228STEXI 3229@item -kernel @var{bzImage} 3230@findex -kernel 3231Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3232or in multiboot format. 3233ETEXI 3234 3235DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3236 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3237STEXI 3238@item -append @var{cmdline} 3239@findex -append 3240Use @var{cmdline} as kernel command line 3241ETEXI 3242 3243DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3244 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3245STEXI 3246@item -initrd @var{file} 3247@findex -initrd 3248Use @var{file} as initial ram disk. 3249 3250@item -initrd "@var{file1} arg=foo,@var{file2}" 3251 3252This syntax is only available with multiboot. 3253 3254Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3255first module. 3256ETEXI 3257 3258DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3259 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3260STEXI 3261@item -dtb @var{file} 3262@findex -dtb 3263Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3264on boot. 3265ETEXI 3266 3267STEXI 3268@end table 3269ETEXI 3270DEFHEADING() 3271 3272DEFHEADING(Debug/Expert options:) 3273STEXI 3274@table @option 3275ETEXI 3276 3277DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3278 "-fw_cfg [name=]<name>,file=<file>\n" 3279 " add named fw_cfg entry with contents from file\n" 3280 "-fw_cfg [name=]<name>,string=<str>\n" 3281 " add named fw_cfg entry with contents from string\n", 3282 QEMU_ARCH_ALL) 3283STEXI 3284 3285@item -fw_cfg [name=]@var{name},file=@var{file} 3286@findex -fw_cfg 3287Add named fw_cfg entry with contents from file @var{file}. 3288 3289@item -fw_cfg [name=]@var{name},string=@var{str} 3290Add named fw_cfg entry with contents from string @var{str}. 3291 3292The terminating NUL character of the contents of @var{str} will not be 3293included as part of the fw_cfg item data. To insert contents with 3294embedded NUL characters, you have to use the @var{file} parameter. 3295 3296The fw_cfg entries are passed by QEMU through to the guest. 3297 3298Example: 3299@example 3300 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3301@end example 3302creates an fw_cfg entry named opt/com.mycompany/blob with contents 3303from ./my_blob.bin. 3304 3305ETEXI 3306 3307DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3308 "-serial dev redirect the serial port to char device 'dev'\n", 3309 QEMU_ARCH_ALL) 3310STEXI 3311@item -serial @var{dev} 3312@findex -serial 3313Redirect the virtual serial port to host character device 3314@var{dev}. The default device is @code{vc} in graphical mode and 3315@code{stdio} in non graphical mode. 3316 3317This option can be used several times to simulate up to 4 serial 3318ports. 3319 3320Use @code{-serial none} to disable all serial ports. 3321 3322Available character devices are: 3323@table @option 3324@item vc[:@var{W}x@var{H}] 3325Virtual console. Optionally, a width and height can be given in pixel with 3326@example 3327vc:800x600 3328@end example 3329It is also possible to specify width or height in characters: 3330@example 3331vc:80Cx24C 3332@end example 3333@item pty 3334[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3335@item none 3336No device is allocated. 3337@item null 3338void device 3339@item chardev:@var{id} 3340Use a named character device defined with the @code{-chardev} option. 3341@item /dev/XXX 3342[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3343parameters are set according to the emulated ones. 3344@item /dev/parport@var{N} 3345[Linux only, parallel port only] Use host parallel port 3346@var{N}. Currently SPP and EPP parallel port features can be used. 3347@item file:@var{filename} 3348Write output to @var{filename}. No character can be read. 3349@item stdio 3350[Unix only] standard input/output 3351@item pipe:@var{filename} 3352name pipe @var{filename} 3353@item COM@var{n} 3354[Windows only] Use host serial port @var{n} 3355@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3356This implements UDP Net Console. 3357When @var{remote_host} or @var{src_ip} are not specified 3358they default to @code{0.0.0.0}. 3359When not using a specified @var{src_port} a random port is automatically chosen. 3360 3361If you just want a simple readonly console you can use @code{netcat} or 3362@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3363@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3364will appear in the netconsole session. 3365 3366If you plan to send characters back via netconsole or you want to stop 3367and start QEMU a lot of times, you should have QEMU use the same 3368source port each time by using something like @code{-serial 3369udp::4555@@:4556} to QEMU. Another approach is to use a patched 3370version of netcat which can listen to a TCP port and send and receive 3371characters via udp. If you have a patched version of netcat which 3372activates telnet remote echo and single char transfer, then you can 3373use the following options to set up a netcat redirector to allow 3374telnet on port 5555 to access the QEMU port. 3375@table @code 3376@item QEMU Options: 3377-serial udp::4555@@:4556 3378@item netcat options: 3379-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3380@item telnet options: 3381localhost 5555 3382@end table 3383 3384@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3385The TCP Net Console has two modes of operation. It can send the serial 3386I/O to a location or wait for a connection from a location. By default 3387the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3388the @var{server} option QEMU will wait for a client socket application 3389to connect to the port before continuing, unless the @code{nowait} 3390option was specified. The @code{nodelay} option disables the Nagle buffering 3391algorithm. The @code{reconnect} option only applies if @var{noserver} is 3392set, if the connection goes down it will attempt to reconnect at the 3393given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3394one TCP connection at a time is accepted. You can use @code{telnet} to 3395connect to the corresponding character device. 3396@table @code 3397@item Example to send tcp console to 192.168.0.2 port 4444 3398-serial tcp:192.168.0.2:4444 3399@item Example to listen and wait on port 4444 for connection 3400-serial tcp::4444,server 3401@item Example to not wait and listen on ip 192.168.0.100 port 4444 3402-serial tcp:192.168.0.100:4444,server,nowait 3403@end table 3404 3405@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3406The telnet protocol is used instead of raw tcp sockets. The options 3407work the same as if you had specified @code{-serial tcp}. The 3408difference is that the port acts like a telnet server or client using 3409telnet option negotiation. This will also allow you to send the 3410MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3411sequence. Typically in unix telnet you do it with Control-] and then 3412type "send break" followed by pressing the enter key. 3413 3414@item websocket:@var{host}:@var{port},server[,nowait][,nodelay] 3415The WebSocket protocol is used instead of raw tcp socket. The port acts as 3416a WebSocket server. Client mode is not supported. 3417 3418@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3419A unix domain socket is used instead of a tcp socket. The option works the 3420same as if you had specified @code{-serial tcp} except the unix domain socket 3421@var{path} is used for connections. 3422 3423@item mon:@var{dev_string} 3424This is a special option to allow the monitor to be multiplexed onto 3425another serial port. The monitor is accessed with key sequence of 3426@key{Control-a} and then pressing @key{c}. 3427@var{dev_string} should be any one of the serial devices specified 3428above. An example to multiplex the monitor onto a telnet server 3429listening on port 4444 would be: 3430@table @code 3431@item -serial mon:telnet::4444,server,nowait 3432@end table 3433When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3434QEMU any more but will be passed to the guest instead. 3435 3436@item braille 3437Braille device. This will use BrlAPI to display the braille output on a real 3438or fake device. 3439 3440@item msmouse 3441Three button serial mouse. Configure the guest to use Microsoft protocol. 3442@end table 3443ETEXI 3444 3445DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3446 "-parallel dev redirect the parallel port to char device 'dev'\n", 3447 QEMU_ARCH_ALL) 3448STEXI 3449@item -parallel @var{dev} 3450@findex -parallel 3451Redirect the virtual parallel port to host device @var{dev} (same 3452devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3453be used to use hardware devices connected on the corresponding host 3454parallel port. 3455 3456This option can be used several times to simulate up to 3 parallel 3457ports. 3458 3459Use @code{-parallel none} to disable all parallel ports. 3460ETEXI 3461 3462DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3463 "-monitor dev redirect the monitor to char device 'dev'\n", 3464 QEMU_ARCH_ALL) 3465STEXI 3466@item -monitor @var{dev} 3467@findex -monitor 3468Redirect the monitor to host device @var{dev} (same devices as the 3469serial port). 3470The default device is @code{vc} in graphical mode and @code{stdio} in 3471non graphical mode. 3472Use @code{-monitor none} to disable the default monitor. 3473ETEXI 3474DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3475 "-qmp dev like -monitor but opens in 'control' mode\n", 3476 QEMU_ARCH_ALL) 3477STEXI 3478@item -qmp @var{dev} 3479@findex -qmp 3480Like -monitor but opens in 'control' mode. 3481ETEXI 3482DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3483 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3484 QEMU_ARCH_ALL) 3485STEXI 3486@item -qmp-pretty @var{dev} 3487@findex -qmp-pretty 3488Like -qmp but uses pretty JSON formatting. 3489ETEXI 3490 3491DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3492 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3493STEXI 3494@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3495@findex -mon 3496Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3497easing human reading and debugging. 3498ETEXI 3499 3500DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3501 "-debugcon dev redirect the debug console to char device 'dev'\n", 3502 QEMU_ARCH_ALL) 3503STEXI 3504@item -debugcon @var{dev} 3505@findex -debugcon 3506Redirect the debug console to host device @var{dev} (same devices as the 3507serial port). The debug console is an I/O port which is typically port 35080xe9; writing to that I/O port sends output to this device. 3509The default device is @code{vc} in graphical mode and @code{stdio} in 3510non graphical mode. 3511ETEXI 3512 3513DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3514 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3515STEXI 3516@item -pidfile @var{file} 3517@findex -pidfile 3518Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3519from a script. 3520ETEXI 3521 3522DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3523 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3524STEXI 3525@item -singlestep 3526@findex -singlestep 3527Run the emulation in single step mode. 3528ETEXI 3529 3530DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3531 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3532 QEMU_ARCH_ALL) 3533STEXI 3534@item --preconfig 3535@findex --preconfig 3536Pause QEMU for interactive configuration before the machine is created, 3537which allows querying and configuring properties that will affect 3538machine initialization. Use QMP command 'x-exit-preconfig' to exit 3539the preconfig state and move to the next state (i.e. run guest if -S 3540isn't used or pause the second time if -S is used). This option is 3541experimental. 3542ETEXI 3543 3544DEF("S", 0, QEMU_OPTION_S, \ 3545 "-S freeze CPU at startup (use 'c' to start execution)\n", 3546 QEMU_ARCH_ALL) 3547STEXI 3548@item -S 3549@findex -S 3550Do not start CPU at startup (you must type 'c' in the monitor). 3551ETEXI 3552 3553DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3554 "-realtime [mlock=on|off]\n" 3555 " run qemu with realtime features\n" 3556 " mlock=on|off controls mlock support (default: on)\n", 3557 QEMU_ARCH_ALL) 3558STEXI 3559@item -realtime mlock=on|off 3560@findex -realtime 3561Run qemu with realtime features. 3562mlocking qemu and guest memory can be enabled via @option{mlock=on} 3563(enabled by default). 3564ETEXI 3565 3566DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3567 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3568 " run qemu with overcommit hints\n" 3569 " mem-lock=on|off controls memory lock support (default: off)\n" 3570 " cpu-pm=on|off controls cpu power management (default: off)\n", 3571 QEMU_ARCH_ALL) 3572STEXI 3573@item -overcommit mem-lock=on|off 3574@item -overcommit cpu-pm=on|off 3575@findex -overcommit 3576Run qemu with hints about host resource overcommit. The default is 3577to assume that host overcommits all resources. 3578 3579Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3580by default). This works when host memory is not overcommitted and reduces the 3581worst-case latency for guest. This is equivalent to @option{realtime}. 3582 3583Guest ability to manage power state of host cpus (increasing latency for other 3584processes on the same host cpu, but decreasing latency for guest) can be 3585enabled via @option{cpu-pm=on} (disabled by default). This works best when 3586host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3587utilization will be incorrect, not taking into account guest idle time. 3588ETEXI 3589 3590DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3591 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3592STEXI 3593@item -gdb @var{dev} 3594@findex -gdb 3595Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3596connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3597stdio are reasonable use case. The latter is allowing to start QEMU from 3598within gdb and establish the connection via a pipe: 3599@example 3600(gdb) target remote | exec @value{qemu_system} -gdb stdio ... 3601@end example 3602ETEXI 3603 3604DEF("s", 0, QEMU_OPTION_s, \ 3605 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3606 QEMU_ARCH_ALL) 3607STEXI 3608@item -s 3609@findex -s 3610Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3611(@pxref{gdb_usage}). 3612ETEXI 3613 3614DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3615 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3616 QEMU_ARCH_ALL) 3617STEXI 3618@item -d @var{item1}[,...] 3619@findex -d 3620Enable logging of specified items. Use '-d help' for a list of log items. 3621ETEXI 3622 3623DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3624 "-D logfile output log to logfile (default stderr)\n", 3625 QEMU_ARCH_ALL) 3626STEXI 3627@item -D @var{logfile} 3628@findex -D 3629Output log in @var{logfile} instead of to stderr 3630ETEXI 3631 3632DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3633 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3634 QEMU_ARCH_ALL) 3635STEXI 3636@item -dfilter @var{range1}[,...] 3637@findex -dfilter 3638Filter debug output to that relevant to a range of target addresses. The filter 3639spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3640@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3641addresses and sizes required. For example: 3642@example 3643 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3644@end example 3645Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3646the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3647block starting at 0xffffffc00005f000. 3648ETEXI 3649 3650DEF("seed", HAS_ARG, QEMU_OPTION_seed, \ 3651 "-seed number seed the pseudo-random number generator\n", 3652 QEMU_ARCH_ALL) 3653STEXI 3654@item -seed @var{number} 3655@findex -seed 3656Force the guest to use a deterministic pseudo-random number generator, seeded 3657with @var{number}. This does not affect crypto routines within the host. 3658ETEXI 3659 3660DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3661 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3662 QEMU_ARCH_ALL) 3663STEXI 3664@item -L @var{path} 3665@findex -L 3666Set the directory for the BIOS, VGA BIOS and keymaps. 3667 3668To list all the data directories, use @code{-L help}. 3669ETEXI 3670 3671DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3672 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3673STEXI 3674@item -bios @var{file} 3675@findex -bios 3676Set the filename for the BIOS. 3677ETEXI 3678 3679DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3680 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3681STEXI 3682@item -enable-kvm 3683@findex -enable-kvm 3684Enable KVM full virtualization support. This option is only available 3685if KVM support is enabled when compiling. 3686ETEXI 3687 3688DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3689 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3690DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3691 "-xen-attach attach to existing xen domain\n" 3692 " libxl will use this when starting QEMU\n", 3693 QEMU_ARCH_ALL) 3694DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3695 "-xen-domid-restrict restrict set of available xen operations\n" 3696 " to specified domain id. (Does not affect\n" 3697 " xenpv machine type).\n", 3698 QEMU_ARCH_ALL) 3699STEXI 3700@item -xen-domid @var{id} 3701@findex -xen-domid 3702Specify xen guest domain @var{id} (XEN only). 3703@item -xen-attach 3704@findex -xen-attach 3705Attach to existing xen domain. 3706libxl will use this when starting QEMU (XEN only). 3707@findex -xen-domid-restrict 3708Restrict set of available xen operations to specified domain id (XEN only). 3709ETEXI 3710 3711DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3712 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3713STEXI 3714@item -no-reboot 3715@findex -no-reboot 3716Exit instead of rebooting. 3717ETEXI 3718 3719DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3720 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3721STEXI 3722@item -no-shutdown 3723@findex -no-shutdown 3724Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3725This allows for instance switching to monitor to commit changes to the 3726disk image. 3727ETEXI 3728 3729DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3730 "-loadvm [tag|id]\n" \ 3731 " start right away with a saved state (loadvm in monitor)\n", 3732 QEMU_ARCH_ALL) 3733STEXI 3734@item -loadvm @var{file} 3735@findex -loadvm 3736Start right away with a saved state (@code{loadvm} in monitor) 3737ETEXI 3738 3739#ifndef _WIN32 3740DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3741 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3742#endif 3743STEXI 3744@item -daemonize 3745@findex -daemonize 3746Daemonize the QEMU process after initialization. QEMU will not detach from 3747standard IO until it is ready to receive connections on any of its devices. 3748This option is a useful way for external programs to launch QEMU without having 3749to cope with initialization race conditions. 3750ETEXI 3751 3752DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3753 "-option-rom rom load a file, rom, into the option ROM space\n", 3754 QEMU_ARCH_ALL) 3755STEXI 3756@item -option-rom @var{file} 3757@findex -option-rom 3758Load the contents of @var{file} as an option ROM. 3759This option is useful to load things like EtherBoot. 3760ETEXI 3761 3762DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3763 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3764 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3765 QEMU_ARCH_ALL) 3766 3767STEXI 3768 3769@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew] 3770@findex -rtc 3771Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3772UTC or local time, respectively. @code{localtime} is required for correct date in 3773MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the 3774format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3775 3776By default the RTC is driven by the host system time. This allows using of the 3777RTC as accurate reference clock inside the guest, specifically if the host 3778time is smoothly following an accurate external reference clock, e.g. via NTP. 3779If you want to isolate the guest time from the host, you can set @option{clock} 3780to @code{rt} instead, which provides a host monotonic clock if host support it. 3781To even prevent the RTC from progressing during suspension, you can set @option{clock} 3782to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in 3783icount mode in order to preserve determinism; however, note that in icount mode 3784the speed of the virtual clock is variable and can in general differ from the 3785host clock. 3786 3787Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3788specifically with Windows' ACPI HAL. This option will try to figure out how 3789many timer interrupts were not processed by the Windows guest and will 3790re-inject them. 3791ETEXI 3792 3793DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3794 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3795 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3796 " instruction, enable aligning the host and virtual clocks\n" \ 3797 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3798STEXI 3799@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3800@findex -icount 3801Enable virtual instruction counter. The virtual cpu will execute one 3802instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3803then the virtual cpu speed will be automatically adjusted to keep virtual 3804time within a few seconds of real time. 3805 3806When the virtual cpu is sleeping, the virtual time will advance at default 3807speed unless @option{sleep=on|off} is specified. 3808With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3809instantly whenever the virtual cpu goes to sleep mode and will not advance 3810if no timer is enabled. This behavior give deterministic execution times from 3811the guest point of view. 3812 3813Note that while this option can give deterministic behavior, it does not 3814provide cycle accurate emulation. Modern CPUs contain superscalar out of 3815order cores with complex cache hierarchies. The number of instructions 3816executed often has little or no correlation with actual performance. 3817 3818@option{align=on} will activate the delay algorithm which will try 3819to synchronise the host clock and the virtual clock. The goal is to 3820have a guest running at the real frequency imposed by the shift option. 3821Whenever the guest clock is behind the host clock and if 3822@option{align=on} is specified then we print a message to the user 3823to inform about the delay. 3824Currently this option does not work when @option{shift} is @code{auto}. 3825Note: The sync algorithm will work for those shift values for which 3826the guest clock runs ahead of the host clock. Typically this happens 3827when the shift value is high (how high depends on the host machine). 3828 3829When @option{rr} option is specified deterministic record/replay is enabled. 3830Replay log is written into @var{filename} file in record mode and 3831read from this file in replay mode. 3832 3833Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3834at the start of execution recording. In replay mode this option is used 3835to load the initial VM state. 3836ETEXI 3837 3838DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3839 "-watchdog model\n" \ 3840 " enable virtual hardware watchdog [default=none]\n", 3841 QEMU_ARCH_ALL) 3842STEXI 3843@item -watchdog @var{model} 3844@findex -watchdog 3845Create a virtual hardware watchdog device. Once enabled (by a guest 3846action), the watchdog must be periodically polled by an agent inside 3847the guest or else the guest will be restarted. Choose a model for 3848which your guest has drivers. 3849 3850The @var{model} is the model of hardware watchdog to emulate. Use 3851@code{-watchdog help} to list available hardware models. Only one 3852watchdog can be enabled for a guest. 3853 3854The following models may be available: 3855@table @option 3856@item ib700 3857iBASE 700 is a very simple ISA watchdog with a single timer. 3858@item i6300esb 3859Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3860dual-timer watchdog. 3861@item diag288 3862A virtual watchdog for s390x backed by the diagnose 288 hypercall 3863(currently KVM only). 3864@end table 3865ETEXI 3866 3867DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3868 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3869 " action when watchdog fires [default=reset]\n", 3870 QEMU_ARCH_ALL) 3871STEXI 3872@item -watchdog-action @var{action} 3873@findex -watchdog-action 3874 3875The @var{action} controls what QEMU will do when the watchdog timer 3876expires. 3877The default is 3878@code{reset} (forcefully reset the guest). 3879Other possible actions are: 3880@code{shutdown} (attempt to gracefully shutdown the guest), 3881@code{poweroff} (forcefully poweroff the guest), 3882@code{inject-nmi} (inject a NMI into the guest), 3883@code{pause} (pause the guest), 3884@code{debug} (print a debug message and continue), or 3885@code{none} (do nothing). 3886 3887Note that the @code{shutdown} action requires that the guest responds 3888to ACPI signals, which it may not be able to do in the sort of 3889situations where the watchdog would have expired, and thus 3890@code{-watchdog-action shutdown} is not recommended for production use. 3891 3892Examples: 3893 3894@table @code 3895@item -watchdog i6300esb -watchdog-action pause 3896@itemx -watchdog ib700 3897@end table 3898ETEXI 3899 3900DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3901 "-echr chr set terminal escape character instead of ctrl-a\n", 3902 QEMU_ARCH_ALL) 3903STEXI 3904 3905@item -echr @var{numeric_ascii_value} 3906@findex -echr 3907Change the escape character used for switching to the monitor when using 3908monitor and serial sharing. The default is @code{0x01} when using the 3909@code{-nographic} option. @code{0x01} is equal to pressing 3910@code{Control-a}. You can select a different character from the ascii 3911control keys where 1 through 26 map to Control-a through Control-z. For 3912instance you could use the either of the following to change the escape 3913character to Control-t. 3914@table @code 3915@item -echr 0x14 3916@itemx -echr 20 3917@end table 3918ETEXI 3919 3920DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3921 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3922STEXI 3923@item -show-cursor 3924@findex -show-cursor 3925Show cursor. 3926ETEXI 3927 3928DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3929 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3930STEXI 3931@item -tb-size @var{n} 3932@findex -tb-size 3933Set TCG translation block cache size. Deprecated, use @samp{-accel tcg,tb-size=@var{n}} 3934instead. 3935ETEXI 3936 3937DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3938 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3939 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3940 "-incoming unix:socketpath\n" \ 3941 " prepare for incoming migration, listen on\n" \ 3942 " specified protocol and socket address\n" \ 3943 "-incoming fd:fd\n" \ 3944 "-incoming exec:cmdline\n" \ 3945 " accept incoming migration on given file descriptor\n" \ 3946 " or from given external command\n" \ 3947 "-incoming defer\n" \ 3948 " wait for the URI to be specified via migrate_incoming\n", 3949 QEMU_ARCH_ALL) 3950STEXI 3951@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3952@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3953@findex -incoming 3954Prepare for incoming migration, listen on a given tcp port. 3955 3956@item -incoming unix:@var{socketpath} 3957Prepare for incoming migration, listen on a given unix socket. 3958 3959@item -incoming fd:@var{fd} 3960Accept incoming migration from a given filedescriptor. 3961 3962@item -incoming exec:@var{cmdline} 3963Accept incoming migration as an output from specified external command. 3964 3965@item -incoming defer 3966Wait for the URI to be specified via migrate_incoming. The monitor can 3967be used to change settings (such as migration parameters) prior to issuing 3968the migrate_incoming to allow the migration to begin. 3969ETEXI 3970 3971DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3972 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3973STEXI 3974@item -only-migratable 3975@findex -only-migratable 3976Only allow migratable devices. Devices will not be allowed to enter an 3977unmigratable state. 3978ETEXI 3979 3980DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3981 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3982STEXI 3983@item -nodefaults 3984@findex -nodefaults 3985Don't create default devices. Normally, QEMU sets the default devices like serial 3986port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3987CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3988default devices. 3989ETEXI 3990 3991#ifndef _WIN32 3992DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3993 "-chroot dir chroot to dir just before starting the VM\n", 3994 QEMU_ARCH_ALL) 3995#endif 3996STEXI 3997@item -chroot @var{dir} 3998@findex -chroot 3999Immediately before starting guest execution, chroot to the specified 4000directory. Especially useful in combination with -runas. 4001ETEXI 4002 4003#ifndef _WIN32 4004DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 4005 "-runas user change to user id user just before starting the VM\n" \ 4006 " user can be numeric uid:gid instead\n", 4007 QEMU_ARCH_ALL) 4008#endif 4009STEXI 4010@item -runas @var{user} 4011@findex -runas 4012Immediately before starting guest execution, drop root privileges, switching 4013to the specified user. 4014ETEXI 4015 4016DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 4017 "-prom-env variable=value\n" 4018 " set OpenBIOS nvram variables\n", 4019 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 4020STEXI 4021@item -prom-env @var{variable}=@var{value} 4022@findex -prom-env 4023Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 4024ETEXI 4025DEF("semihosting", 0, QEMU_OPTION_semihosting, 4026 "-semihosting semihosting mode\n", 4027 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4028 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4029STEXI 4030@item -semihosting 4031@findex -semihosting 4032Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II only). 4033ETEXI 4034DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 4035 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]]\n" \ 4036 " semihosting configuration\n", 4037QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 4038QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2) 4039STEXI 4040@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,arg=str[,...]] 4041@findex -semihosting-config 4042Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II only). 4043@table @option 4044@item target=@code{native|gdb|auto} 4045Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 4046or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 4047during debug sessions and @code{native} otherwise. 4048@item chardev=@var{str1} 4049Send the output to a chardev backend output for native or auto output when not in gdb 4050@item arg=@var{str1},arg=@var{str2},... 4051Allows the user to pass input arguments, and can be used multiple times to build 4052up a list. The old-style @code{-kernel}/@code{-append} method of passing a 4053command line is still supported for backward compatibility. If both the 4054@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 4055specified, the former is passed to semihosting as it always takes precedence. 4056@end table 4057ETEXI 4058DEF("old-param", 0, QEMU_OPTION_old_param, 4059 "-old-param old param mode\n", QEMU_ARCH_ARM) 4060STEXI 4061@item -old-param 4062@findex -old-param (ARM) 4063Old param mode (ARM only). 4064ETEXI 4065 4066DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 4067 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 4068 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 4069 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 4070 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 4071 " by the kernel, but typically no longer used by modern\n" \ 4072 " C library implementations.\n" \ 4073 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 4074 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 4075 " The value 'children' will deny set*uid|gid system calls for\n" \ 4076 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 4077 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 4078 " blacklisting *fork and execve\n" \ 4079 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 4080 QEMU_ARCH_ALL) 4081STEXI 4082@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 4083@findex -sandbox 4084Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4085disable it. The default is 'off'. 4086@table @option 4087@item obsolete=@var{string} 4088Enable Obsolete system calls 4089@item elevateprivileges=@var{string} 4090Disable set*uid|gid system calls 4091@item spawn=@var{string} 4092Disable *fork and execve 4093@item resourcecontrol=@var{string} 4094Disable process affinity and schedular priority 4095@end table 4096ETEXI 4097 4098DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4099 "-readconfig <file>\n", QEMU_ARCH_ALL) 4100STEXI 4101@item -readconfig @var{file} 4102@findex -readconfig 4103Read device configuration from @var{file}. This approach is useful when you want to spawn 4104QEMU process with many command line options but you don't want to exceed the command line 4105character limit. 4106ETEXI 4107DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4108 "-writeconfig <file>\n" 4109 " read/write config file\n", QEMU_ARCH_ALL) 4110STEXI 4111@item -writeconfig @var{file} 4112@findex -writeconfig 4113Write device configuration to @var{file}. The @var{file} can be either filename to save 4114command line and device configuration into file or dash @code{-}) character to print the 4115output to stdout. This can be later used as input file for @code{-readconfig} option. 4116ETEXI 4117 4118DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4119 "-no-user-config\n" 4120 " do not load default user-provided config files at startup\n", 4121 QEMU_ARCH_ALL) 4122STEXI 4123@item -no-user-config 4124@findex -no-user-config 4125The @code{-no-user-config} option makes QEMU not load any of the user-provided 4126config files on @var{sysconfdir}. 4127ETEXI 4128 4129DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4130 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4131 " specify tracing options\n", 4132 QEMU_ARCH_ALL) 4133STEXI 4134HXCOMM This line is not accurate, as some sub-options are backend-specific but 4135HXCOMM HX does not support conditional compilation of text. 4136@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4137@findex -trace 4138@include qemu-option-trace.texi 4139ETEXI 4140DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, 4141 "-plugin [file=]<file>[,arg=<string>]\n" 4142 " load a plugin\n", 4143 QEMU_ARCH_ALL) 4144STEXI 4145@item -plugin file=@var{file}[,arg=@var{string}] 4146@findex -plugin 4147 4148Load a plugin. 4149 4150@table @option 4151@item file=@var{file} 4152Load the given plugin from a shared library file. 4153@item arg=@var{string} 4154Argument string passed to the plugin. (Can be given multiple times.) 4155@end table 4156ETEXI 4157 4158HXCOMM Internal use 4159DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4160DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4161 4162#ifdef __linux__ 4163DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4164 "-enable-fips enable FIPS 140-2 compliance\n", 4165 QEMU_ARCH_ALL) 4166#endif 4167STEXI 4168@item -enable-fips 4169@findex -enable-fips 4170Enable FIPS 140-2 compliance mode. 4171ETEXI 4172 4173HXCOMM Deprecated by -accel tcg 4174DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4175 4176DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4177 "-msg timestamp[=on|off]\n" 4178 " change the format of messages\n" 4179 " on|off controls leading timestamps (default:on)\n", 4180 QEMU_ARCH_ALL) 4181STEXI 4182@item -msg timestamp[=on|off] 4183@findex -msg 4184prepend a timestamp to each log message.(default:on) 4185ETEXI 4186 4187DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4188 "-dump-vmstate <file>\n" 4189 " Output vmstate information in JSON format to file.\n" 4190 " Use the scripts/vmstate-static-checker.py file to\n" 4191 " check for possible regressions in migration code\n" 4192 " by comparing two such vmstate dumps.\n", 4193 QEMU_ARCH_ALL) 4194STEXI 4195@item -dump-vmstate @var{file} 4196@findex -dump-vmstate 4197Dump json-encoded vmstate information for current machine type to file 4198in @var{file} 4199ETEXI 4200 4201DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile, 4202 "-enable-sync-profile\n" 4203 " enable synchronization profiling\n", 4204 QEMU_ARCH_ALL) 4205STEXI 4206@item -enable-sync-profile 4207@findex -enable-sync-profile 4208Enable synchronization profiling. 4209ETEXI 4210 4211STEXI 4212@end table 4213ETEXI 4214DEFHEADING() 4215 4216DEFHEADING(Generic object creation:) 4217STEXI 4218@table @option 4219ETEXI 4220 4221DEF("object", HAS_ARG, QEMU_OPTION_object, 4222 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4223 " create a new object of type TYPENAME setting properties\n" 4224 " in the order they are specified. Note that the 'id'\n" 4225 " property must be set. These objects are placed in the\n" 4226 " '/objects' path.\n", 4227 QEMU_ARCH_ALL) 4228STEXI 4229@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4230@findex -object 4231Create a new object of type @var{typename} setting properties 4232in the order they are specified. Note that the 'id' 4233property must be set. These objects are placed in the 4234'/objects' path. 4235 4236@table @option 4237 4238@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} 4239 4240Creates a memory file backend object, which can be used to back 4241the guest RAM with huge pages. 4242 4243The @option{id} parameter is a unique ID that will be used to reference this 4244memory region when configuring the @option{-numa} argument. 4245 4246The @option{size} option provides the size of the memory region, and accepts 4247common suffixes, eg @option{500M}. 4248 4249The @option{mem-path} provides the path to either a shared memory or huge page 4250filesystem mount. 4251 4252The @option{share} boolean option determines whether the memory 4253region is marked as private to QEMU, or shared. The latter allows 4254a co-operating external process to access the QEMU memory region. 4255 4256The @option{share} is also required for pvrdma devices due to 4257limitations in the RDMA API provided by Linux. 4258 4259Setting share=on might affect the ability to configure NUMA 4260bindings for the memory backend under some circumstances, see 4261Documentation/vm/numa_memory_policy.txt on the Linux kernel 4262source tree for additional details. 4263 4264Setting the @option{discard-data} boolean option to @var{on} 4265indicates that file contents can be destroyed when QEMU exits, 4266to avoid unnecessarily flushing data to the backing file. Note 4267that @option{discard-data} is only an optimization, and QEMU 4268might not discard file contents if it aborts unexpectedly or is 4269terminated using SIGKILL. 4270 4271The @option{merge} boolean option enables memory merge, also known as 4272MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4273memory deduplication. 4274 4275Setting the @option{dump} boolean option to @var{off} excludes the memory from 4276core dumps. This feature is also known as MADV_DONTDUMP. 4277 4278The @option{prealloc} boolean option enables memory preallocation. 4279 4280The @option{host-nodes} option binds the memory range to a list of NUMA host 4281nodes. 4282 4283The @option{policy} option sets the NUMA policy to one of the following values: 4284 4285@table @option 4286@item @var{default} 4287default host policy 4288 4289@item @var{preferred} 4290prefer the given host node list for allocation 4291 4292@item @var{bind} 4293restrict memory allocation to the given host node list 4294 4295@item @var{interleave} 4296interleave memory allocations across the given host node list 4297@end table 4298 4299The @option{align} option specifies the base address alignment when 4300QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4301@option{2M}. Some backend store specified by @option{mem-path} 4302requires an alignment different than the default one used by QEMU, eg 4303the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4304such cases, users can specify the required alignment via this option. 4305 4306The @option{pmem} option specifies whether the backing file specified 4307by @option{mem-path} is in host persistent memory that can be accessed 4308using the SNIA NVM programming model (e.g. Intel NVDIMM). 4309If @option{pmem} is set to 'on', QEMU will take necessary operations to 4310guarantee the persistence of its own writes to @option{mem-path} 4311(e.g. in vNVDIMM label emulation and live migration). 4312Also, we will map the backend-file with MAP_SYNC flag, which ensures the 4313file metadata is in sync for @option{mem-path} in case of host crash 4314or a power failure. MAP_SYNC requires support from both the host kernel 4315(since Linux kernel 4.15) and the filesystem of @option{mem-path} mounted 4316with DAX option. 4317 4318@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} 4319 4320Creates a memory backend object, which can be used to back the guest RAM. 4321Memory backend objects offer more control than the @option{-m} option that is 4322traditionally used to define guest RAM. Please refer to 4323@option{memory-backend-file} for a description of the options. 4324 4325@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} 4326 4327Creates an anonymous memory file backend object, which allows QEMU to 4328share the memory with an external process (e.g. when using 4329vhost-user). The memory is allocated with memfd and optional 4330sealing. (Linux only) 4331 4332The @option{seal} option creates a sealed-file, that will block 4333further resizing the memory ('on' by default). 4334 4335The @option{hugetlb} option specify the file to be created resides in 4336the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4337the @option{hugetlb} option, the @option{hugetlbsize} option specify 4338the hugetlb page size on systems that support multiple hugetlb page 4339sizes (it must be a power of 2 value supported by the system). 4340 4341In some versions of Linux, the @option{hugetlb} option is incompatible 4342with the @option{seal} option (requires at least Linux 4.16). 4343 4344Please refer to @option{memory-backend-file} for a description of the 4345other options. 4346 4347The @option{share} boolean option is @var{on} by default with memfd. 4348 4349@item -object rng-builtin,id=@var{id} 4350 4351Creates a random number generator backend which obtains entropy from 4352QEMU builtin functions. The @option{id} parameter is a unique ID that 4353will be used to reference this entropy backend from the @option{virtio-rng} 4354device. By default, the @option{virtio-rng} device uses this RNG backend. 4355 4356@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4357 4358Creates a random number generator backend which obtains entropy from 4359a device on the host. The @option{id} parameter is a unique ID that 4360will be used to reference this entropy backend from the @option{virtio-rng} 4361device. The @option{filename} parameter specifies which file to obtain 4362entropy from and if omitted defaults to @option{/dev/urandom}. 4363 4364@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4365 4366Creates a random number generator backend which obtains entropy from 4367an external daemon running on the host. The @option{id} parameter is 4368a unique ID that will be used to reference this entropy backend from 4369the @option{virtio-rng} device. The @option{chardev} parameter is 4370the unique ID of a character device backend that provides the connection 4371to the RNG daemon. 4372 4373@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4374 4375Creates a TLS anonymous credentials object, which can be used to provide 4376TLS support on network backends. The @option{id} parameter is a unique 4377ID which network backends will use to access the credentials. The 4378@option{endpoint} is either @option{server} or @option{client} depending 4379on whether the QEMU network backend that uses the credentials will be 4380acting as a client or as a server. If @option{verify-peer} is enabled 4381(the default) then once the handshake is completed, the peer credentials 4382will be verified, though this is a no-op for anonymous credentials. 4383 4384The @var{dir} parameter tells QEMU where to find the credential 4385files. For server endpoints, this directory may contain a file 4386@var{dh-params.pem} providing diffie-hellman parameters to use 4387for the TLS server. If the file is missing, QEMU will generate 4388a set of DH parameters at startup. This is a computationally 4389expensive operation that consumes random pool entropy, so it is 4390recommended that a persistent set of parameters be generated 4391upfront and saved. 4392 4393@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4394 4395Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4396TLS support on network backends. The @option{id} parameter is a unique 4397ID which network backends will use to access the credentials. The 4398@option{endpoint} is either @option{server} or @option{client} depending 4399on whether the QEMU network backend that uses the credentials will be 4400acting as a client or as a server. For clients only, @option{username} 4401is the username which will be sent to the server. If omitted 4402it defaults to ``qemu''. 4403 4404The @var{dir} parameter tells QEMU where to find the keys file. 4405It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4406pairs. This file can most easily be created using the GnuTLS 4407@code{psktool} program. 4408 4409For server endpoints, @var{dir} may also contain a file 4410@var{dh-params.pem} providing diffie-hellman parameters to use 4411for the TLS server. If the file is missing, QEMU will generate 4412a set of DH parameters at startup. This is a computationally 4413expensive operation that consumes random pool entropy, so it is 4414recommended that a persistent set of parameters be generated 4415up front and saved. 4416 4417@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} 4418 4419Creates a TLS anonymous credentials object, which can be used to provide 4420TLS support on network backends. The @option{id} parameter is a unique 4421ID which network backends will use to access the credentials. The 4422@option{endpoint} is either @option{server} or @option{client} depending 4423on whether the QEMU network backend that uses the credentials will be 4424acting as a client or as a server. If @option{verify-peer} is enabled 4425(the default) then once the handshake is completed, the peer credentials 4426will be verified. With x509 certificates, this implies that the clients 4427must be provided with valid client certificates too. 4428 4429The @var{dir} parameter tells QEMU where to find the credential 4430files. For server endpoints, this directory may contain a file 4431@var{dh-params.pem} providing diffie-hellman parameters to use 4432for the TLS server. If the file is missing, QEMU will generate 4433a set of DH parameters at startup. This is a computationally 4434expensive operation that consumes random pool entropy, so it is 4435recommended that a persistent set of parameters be generated 4436upfront and saved. 4437 4438For x509 certificate credentials the directory will contain further files 4439providing the x509 certificates. The certificates must be stored 4440in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4441@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4442@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4443 4444For the @var{server-key.pem} and @var{client-key.pem} files which 4445contain sensitive private keys, it is possible to use an encrypted 4446version by providing the @var{passwordid} parameter. This provides 4447the ID of a previously created @code{secret} object containing the 4448password for decryption. 4449 4450The @var{priority} parameter allows to override the global default 4451priority used by gnutls. This can be useful if the system administrator 4452needs to use a weaker set of crypto priorities for QEMU without 4453potentially forcing the weakness onto all applications. Or conversely 4454if one wants wants a stronger default for QEMU than for all other 4455applications, they can do this through this parameter. Its format is 4456a gnutls priority string as described at 4457@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4458 4459@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4460 4461Interval @var{t} can't be 0, this filter batches the packet delivery: all 4462packets arriving in a given interval on netdev @var{netdevid} are delayed 4463until the end of the interval. Interval is in microseconds. 4464@option{status} is optional that indicate whether the netfilter is 4465on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4466 4467queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4468 4469@option{all}: the filter is attached both to the receive and the transmit 4470 queue of the netdev (default). 4471 4472@option{rx}: the filter is attached to the receive queue of the netdev, 4473 where it will receive packets sent to the netdev. 4474 4475@option{tx}: the filter is attached to the transmit queue of the netdev, 4476 where it will receive packets sent by the netdev. 4477 4478@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4479 4480filter-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. 4481 4482@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4483 4484filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4485@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4486filter-redirector will redirect packet with vnet_hdr_len. 4487Create a filter-redirector we need to differ outdev id from indev id, id can not 4488be the same. we can just use indev or outdev, but at least one of indev or outdev 4489need to be specified. 4490 4491@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4492 4493Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4494secondary from primary to keep secondary tcp connection,and rewrite 4495tcp packet to primary from secondary make tcp packet can be handled by 4496client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4497 4498usage: 4499colo secondary: 4500-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4501-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4502-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4503 4504@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4505 4506Dump the network traffic on netdev @var{dev} to the file specified by 4507@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4508The file format is libpcap, so it can be analyzed with tools such as tcpdump 4509or Wireshark. 4510 4511@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}] 4512 4513Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4514secondary packet. If the packets are same, we will output primary 4515packet to outdev@var{chardevid}, else we will notify colo-frame 4516do checkpoint and send primary packet to outdev@var{chardevid}. 4517In order to improve efficiency, we need to put the task of comparison 4518in another thread. If it has the vnet_hdr_support flag, colo compare 4519will send/recv packet with vnet_hdr_len. 4520If you want to use Xen COLO, will need the notify_dev to notify Xen 4521colo-frame to do checkpoint. 4522 4523we must use it with the help of filter-mirror and filter-redirector. 4524 4525@example 4526 4527KVM COLO 4528 4529primary: 4530-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4531-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4532-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4533-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4534-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4535-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4536-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4537-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4538-object iothread,id=iothread1 4539-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4540-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4541-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4542-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1 4543 4544secondary: 4545-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4546-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4547-chardev socket,id=red0,host=3.3.3.3,port=9003 4548-chardev socket,id=red1,host=3.3.3.3,port=9004 4549-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4550-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4551 4552 4553Xen COLO 4554 4555primary: 4556-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4557-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4558-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4559-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4560-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4561-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4562-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4563-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4564-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait 4565-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4566-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4567-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4568-object iothread,id=iothread1 4569-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1 4570 4571secondary: 4572-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4573-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4574-chardev socket,id=red0,host=3.3.3.3,port=9003 4575-chardev socket,id=red1,host=3.3.3.3,port=9004 4576-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4577-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4578 4579@end example 4580 4581If you want to know the detail of above command line, you can read 4582the colo-compare git log. 4583 4584@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4585 4586Creates a cryptodev backend which executes crypto opreation from 4587the QEMU cipher APIS. The @var{id} parameter is 4588a unique ID that will be used to reference this cryptodev backend from 4589the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4590which specify the queue number of cryptodev backend, the default of 4591@var{queues} is 1. 4592 4593@example 4594 4595 # @value{qemu_system} \ 4596 [...] \ 4597 -object cryptodev-backend-builtin,id=cryptodev0 \ 4598 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4599 [...] 4600@end example 4601 4602@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4603 4604Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4605The @var{id} parameter is a unique ID that will be used to reference this 4606cryptodev backend from the @option{virtio-crypto} device. 4607The chardev should be a unix domain socket backed one. The vhost-user uses 4608a specifically defined protocol to pass vhost ioctl replacement messages 4609to an application on the other end of the socket. 4610The @var{queues} parameter is optional, which specify the queue number 4611of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4612 4613@example 4614 4615 # @value{qemu_system} \ 4616 [...] \ 4617 -chardev socket,id=chardev0,path=/path/to/socket \ 4618 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4619 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4620 [...] 4621@end example 4622 4623@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4624@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4625 4626Defines a secret to store a password, encryption key, or some other sensitive 4627data. The sensitive data can either be passed directly via the @var{data} 4628parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4629parameter is insecure unless the sensitive data is encrypted. 4630 4631The sensitive data can be provided in raw format (the default), or base64. 4632When encoded as JSON, the raw format only supports valid UTF-8 characters, 4633so base64 is recommended for sending binary data. QEMU will convert from 4634which ever format is provided to the format it needs internally. eg, an 4635RBD password can be provided in raw format, even though it will be base64 4636encoded when passed onto the RBD sever. 4637 4638For added protection, it is possible to encrypt the data associated with 4639a secret using the AES-256-CBC cipher. Use of encryption is indicated 4640by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4641parameter provides the ID of a previously defined secret that contains 4642the AES-256 decryption key. This key should be 32-bytes long and be 4643base64 encoded. The @var{iv} parameter provides the random initialization 4644vector used for encryption of this particular secret and should be a 4645base64 encrypted string of the 16-byte IV. 4646 4647The simplest (insecure) usage is to provide the secret inline 4648 4649@example 4650 4651 # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw 4652 4653@end example 4654 4655The simplest secure usage is to provide the secret via a file 4656 4657 # printf "letmein" > mypasswd.txt 4658 # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw 4659 4660For greater security, AES-256-CBC should be used. To illustrate usage, 4661consider the openssl command line tool which can encrypt the data. Note 4662that when encrypting, the plaintext must be padded to the cipher block 4663size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4664 4665First a master key needs to be created in base64 encoding: 4666 4667@example 4668 # openssl rand -base64 32 > key.b64 4669 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4670@end example 4671 4672Each secret to be encrypted needs to have a random initialization vector 4673generated. These do not need to be kept secret 4674 4675@example 4676 # openssl rand -base64 16 > iv.b64 4677 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4678@end example 4679 4680The secret to be defined can now be encrypted, in this case we're 4681telling openssl to base64 encode the result, but it could be left 4682as raw bytes if desired. 4683 4684@example 4685 # SECRET=$(printf "letmein" | 4686 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4687@end example 4688 4689When launching QEMU, create a master secret pointing to @code{key.b64} 4690and specify that to be used to decrypt the user password. Pass the 4691contents of @code{iv.b64} to the second secret 4692 4693@example 4694 # @value{qemu_system} \ 4695 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4696 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4697 data=$SECRET,iv=$(<iv.b64) 4698@end example 4699 4700@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}] 4701 4702Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4703to provide the guest memory encryption support on AMD processors. 4704 4705When memory encryption is enabled, one of the physical address bit (aka the 4706C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4707is used to provide the C-bit position. The C-bit position is Host family dependent 4708hence user must provide this value. On EPYC, the value should be 47. 4709 4710When memory encryption is enabled, we loose certain bits in physical address space. 4711The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4712physical address space. Similar to C-bit, the value is Host family dependent. 4713On EPYC, the value should be 5. 4714 4715The @option{sev-device} provides the device file to use for communicating with 4716the SEV firmware running inside AMD Secure Processor. The default device is 4717'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4718created by CCP driver. 4719 4720The @option{policy} provides the guest policy to be enforced by the SEV firmware 4721and restrict what configuration and operational commands can be performed on this 4722guest by the hypervisor. The policy should be provided by the guest owner and is 4723bound to the guest and cannot be changed throughout the lifetime of the guest. 4724The default is 0. 4725 4726If guest @option{policy} allows sharing the key with another SEV guest then 4727@option{handle} can be use to provide handle of the guest from which to share 4728the key. 4729 4730The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4731Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4732are used for establishing a cryptographic session with the guest owner to 4733negotiate keys used for attestation. The file must be encoded in base64. 4734 4735e.g to launch a SEV guest 4736@example 4737 # @value{qemu_system_x86} \ 4738 ...... 4739 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4740 -machine ...,memory-encryption=sev0 4741 ..... 4742 4743@end example 4744 4745 4746@item -object authz-simple,id=@var{id},identity=@var{string} 4747 4748Create an authorization object that will control access to network services. 4749 4750The @option{identity} parameter is identifies the user and its format 4751depends on the network service that authorization object is associated 4752with. For authorizing based on TLS x509 certificates, the identity must 4753be the x509 distinguished name. Note that care must be taken to escape 4754any commas in the distinguished name. 4755 4756An example authorization object to validate a x509 distinguished name 4757would look like: 4758@example 4759 # @value{qemu_system} \ 4760 ... 4761 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \ 4762 ... 4763@end example 4764 4765Note the use of quotes due to the x509 distinguished name containing 4766whitespace, and escaping of ','. 4767 4768@item -object authz-listfile,id=@var{id},filename=@var{path},refresh=@var{yes|no} 4769 4770Create an authorization object that will control access to network services. 4771 4772The @option{filename} parameter is the fully qualified path to a file 4773containing the access control list rules in JSON format. 4774 4775An example set of rules that match against SASL usernames might look 4776like: 4777 4778@example 4779 @{ 4780 "rules": [ 4781 @{ "match": "fred", "policy": "allow", "format": "exact" @}, 4782 @{ "match": "bob", "policy": "allow", "format": "exact" @}, 4783 @{ "match": "danb", "policy": "deny", "format": "glob" @}, 4784 @{ "match": "dan*", "policy": "allow", "format": "exact" @}, 4785 ], 4786 "policy": "deny" 4787 @} 4788@end example 4789 4790When checking access the object will iterate over all the rules and 4791the first rule to match will have its @option{policy} value returned 4792as the result. If no rules match, then the default @option{policy} 4793value is returned. 4794 4795The rules can either be an exact string match, or they can use the 4796simple UNIX glob pattern matching to allow wildcards to be used. 4797 4798If @option{refresh} is set to true the file will be monitored 4799and automatically reloaded whenever its content changes. 4800 4801As with the @code{authz-simple} object, the format of the identity 4802strings being matched depends on the network service, but is usually 4803a TLS x509 distinguished name, or a SASL username. 4804 4805An example authorization object to validate a SASL username 4806would look like: 4807@example 4808 # @value{qemu_system} \ 4809 ... 4810 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes 4811 ... 4812@end example 4813 4814@item -object authz-pam,id=@var{id},service=@var{string} 4815 4816Create an authorization object that will control access to network services. 4817 4818The @option{service} parameter provides the name of a PAM service to use 4819for authorization. It requires that a file @code{/etc/pam.d/@var{service}} 4820exist to provide the configuration for the @code{account} subsystem. 4821 4822An example authorization object to validate a TLS x509 distinguished 4823name would look like: 4824 4825@example 4826 # @value{qemu_system} \ 4827 ... 4828 -object authz-pam,id=auth0,service=qemu-vnc 4829 ... 4830@end example 4831 4832There would then be a corresponding config file for PAM at 4833@code{/etc/pam.d/qemu-vnc} that contains: 4834 4835@example 4836account requisite pam_listfile.so item=user sense=allow \ 4837 file=/etc/qemu/vnc.allow 4838@end example 4839 4840Finally the @code{/etc/qemu/vnc.allow} file would contain 4841the list of x509 distingished names that are permitted 4842access 4843 4844@example 4845CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB 4846@end example 4847 4848@item -object iothread,id=@var{id},poll-max-ns=@var{poll-max-ns},poll-grow=@var{poll-grow},poll-shrink=@var{poll-shrink} 4849 4850Creates a dedicated event loop thread that devices can be assigned to. This is 4851known as an IOThread. By default device emulation happens in vCPU threads or 4852the main event loop thread. This can become a scalability bottleneck. 4853IOThreads allow device emulation and I/O to run on other host CPUs. 4854 4855The @option{id} parameter is a unique ID that will be used to reference this 4856IOThread from @option{-device ...,iothread=@var{id}}. Multiple devices can be 4857assigned to an IOThread. Note that not all devices support an 4858@option{iothread} parameter. 4859 4860The @code{query-iothreads} QMP command lists IOThreads and reports their thread 4861IDs so that the user can configure host CPU pinning/affinity. 4862 4863IOThreads use an adaptive polling algorithm to reduce event loop latency. 4864Instead of entering a blocking system call to monitor file descriptors and then 4865pay the cost of being woken up when an event occurs, the polling algorithm 4866spins waiting for events for a short time. The algorithm's default parameters 4867are suitable for many cases but can be adjusted based on knowledge of the 4868workload and/or host device latency. 4869 4870The @option{poll-max-ns} parameter is the maximum number of nanoseconds to busy 4871wait for events. Polling can be disabled by setting this value to 0. 4872 4873The @option{poll-grow} parameter is the multiplier used to increase the polling 4874time when the algorithm detects it is missing events due to not polling long 4875enough. 4876 4877The @option{poll-shrink} parameter is the divisor used to decrease the polling 4878time when the algorithm detects it is spending too long polling without 4879encountering events. 4880 4881The polling parameters can be modified at run-time using the @code{qom-set} command (where @code{iothread1} is the IOThread's @code{id}): 4882 4883@example 4884(qemu) qom-set /objects/iothread1 poll-max-ns 100000 4885@end example 4886 4887@end table 4888 4889ETEXI 4890 4891 4892HXCOMM This is the last statement. Insert new options before this line! 4893STEXI 4894@end table 4895ETEXI 4896
