1HXCOMM Use DEFHEADING() to define headings in both help text and texi 2HXCOMM Text between STEXI and ETEXI are copied to texi version and 3HXCOMM discarded from C version 4HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to 5HXCOMM construct option structures, enums and help message for specified 6HXCOMM architectures. 7HXCOMM HXCOMM can be used for comments, discarded from both texi and C 8 9DEFHEADING(Standard options:) 10STEXI 11@table @option 12ETEXI 13 14DEF("help", 0, QEMU_OPTION_h, 15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL) 16STEXI 17@item -h 18@findex -h 19Display help and exit 20ETEXI 21 22DEF("version", 0, QEMU_OPTION_version, 23 "-version display version information and exit\n", QEMU_ARCH_ALL) 24STEXI 25@item -version 26@findex -version 27Display version information and exit 28ETEXI 29 30DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ 31 "-machine [type=]name[,prop[=value][,...]]\n" 32 " selects emulated machine ('-machine help' for list)\n" 33 " property accel=accel1[:accel2[:...]] selects accelerator\n" 34 " supported accelerators are kvm, xen, hax, hvf, whpx or tcg (default: tcg)\n" 35 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" 36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 37 " kvm_shadow_mem=size of KVM shadow MMU in bytes\n" 38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 39 " mem-merge=on|off controls memory merge support (default: on)\n" 40 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n" 44 " nvdimm=on|off controls NVDIMM support (default=off)\n" 45 " enforce-config-section=on|off enforce configuration section migration (default=off)\n" 46 " memory-encryption=@var{} memory encryption object to use (default=none)\n", 47 QEMU_ARCH_ALL) 48STEXI 49@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 50@findex -machine 51Select the emulated machine by @var{name}. Use @code{-machine help} to list 52available machines. 53 54For architectures which aim to support live migration compatibility 55across releases, each release will introduce a new versioned machine 56type. For example, the 2.8.0 release introduced machine types 57``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. 58 59To allow live migration of guests from QEMU version 2.8.0, to QEMU 60version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' 61and ``pc-q35-2.8'' machines too. To allow users live migrating VMs 62to skip multiple intermediate releases when upgrading, new releases 63of QEMU will support machine types from many previous versions. 64 65Supported machine properties are: 66@table @option 67@item accel=@var{accels1}[:@var{accels2}[:...]] 68This is used to enable an accelerator. Depending on the target architecture, 69kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 70more than one accelerator specified, the next one is used if the previous one 71fails to initialize. 72@item kernel_irqchip=on|off 73Controls in-kernel irqchip support for the chosen accelerator when available. 74@item gfx_passthru=on|off 75Enables IGD GFX passthrough support for the chosen machine when available. 76@item vmport=on|off|auto 77Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 78value based on accel. For accel=xen the default is off otherwise the default 79is on. 80@item kvm_shadow_mem=size 81Defines the size of the KVM shadow MMU. 82@item dump-guest-core=on|off 83Include guest memory in a core dump. The default is on. 84@item mem-merge=on|off 85Enables or disables memory merge support. This feature, when supported by 86the host, de-duplicates identical memory pages among VMs instances 87(enabled by default). 88@item aes-key-wrap=on|off 89Enables or disables AES key wrapping support on s390-ccw hosts. This feature 90controls whether AES wrapping keys will be created to allow 91execution of AES cryptographic functions. The default is on. 92@item dea-key-wrap=on|off 93Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 94controls whether DEA wrapping keys will be created to allow 95execution of DEA cryptographic functions. The default is on. 96@item nvdimm=on|off 97Enables or disables NVDIMM support. The default is off. 98@item enforce-config-section=on|off 99If @option{enforce-config-section} is set to @var{on}, force migration 100code to send configuration section even if the machine-type sets the 101@option{migration.send-configuration} property to @var{off}. 102NOTE: this parameter is deprecated. Please use @option{-global} 103@option{migration.send-configuration}=@var{on|off} instead. 104@item memory-encryption=@var{} 105Memory encryption object to use. The default is none. 106@end table 107ETEXI 108 109HXCOMM Deprecated by -machine 110DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 111 112DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 113 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 114STEXI 115@item -cpu @var{model} 116@findex -cpu 117Select CPU model (@code{-cpu help} for list and additional feature selection) 118ETEXI 119 120DEF("accel", HAS_ARG, QEMU_OPTION_accel, 121 "-accel [accel=]accelerator[,thread=single|multi]\n" 122 " select accelerator (kvm, xen, hax, hvf, whpx or tcg; use 'help' for a list)\n" 123 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 124STEXI 125@item -accel @var{name}[,prop=@var{value}[,...]] 126@findex -accel 127This is used to enable an accelerator. Depending on the target architecture, 128kvm, xen, hax, hvf, whpx or tcg can be available. By default, tcg is used. If there is 129more than one accelerator specified, the next one is used if the previous one 130fails to initialize. 131@table @option 132@item thread=single|multi 133Controls number of TCG threads. When the TCG is multi-threaded there will be one 134thread per vCPU therefor taking advantage of additional host cores. The default 135is to enable multi-threading where both the back-end and front-ends support it and 136no incompatible TCG features have been enabled (e.g. icount/replay). 137@end table 138ETEXI 139 140DEF("smp", HAS_ARG, QEMU_OPTION_smp, 141 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 142 " set the number of CPUs to 'n' [default=1]\n" 143 " maxcpus= maximum number of total cpus, including\n" 144 " offline CPUs for hotplug, etc\n" 145 " cores= number of CPU cores on one socket\n" 146 " threads= number of threads on one CPU core\n" 147 " sockets= number of discrete sockets in the system\n", 148 QEMU_ARCH_ALL) 149STEXI 150@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 151@findex -smp 152Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 153CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 154to 4. 155For the PC target, the number of @var{cores} per socket, the number 156of @var{threads} per cores and the total number of @var{sockets} can be 157specified. Missing values will be computed. If any on the three values is 158given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 159specifies the maximum number of hotpluggable CPUs. 160ETEXI 161 162DEF("numa", HAS_ARG, QEMU_OPTION_numa, 163 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 164 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 165 "-numa dist,src=source,dst=destination,val=distance\n" 166 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n", 167 QEMU_ARCH_ALL) 168STEXI 169@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 170@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 171@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 172@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 173@findex -numa 174Define a NUMA node and assign RAM and VCPUs to it. 175Set the NUMA distance from a source node to a destination node. 176 177Legacy VCPU assignment uses @samp{cpus} option where 178@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 179@samp{cpus} option represent a contiguous range of CPU indexes 180(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 181set of VCPUs can be represented by providing multiple @samp{cpus} 182options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 183split between them. 184 185For example, the following option assigns VCPUs 0, 1, 2 and 5 to 186a NUMA node: 187@example 188-numa node,cpus=0-2,cpus=5 189@end example 190 191@samp{cpu} option is a new alternative to @samp{cpus} option 192which uses @samp{socket-id|core-id|thread-id} properties to assign 193CPU objects to a @var{node} using topology layout properties of CPU. 194The set of properties is machine specific, and depends on used 195machine type/@samp{smp} options. It could be queried with 196@samp{hotpluggable-cpus} monitor command. 197@samp{node-id} property specifies @var{node} to which CPU object 198will be assigned, it's required for @var{node} to be declared 199with @samp{node} option before it's used with @samp{cpu} option. 200 201For example: 202@example 203-M pc \ 204-smp 1,sockets=2,maxcpus=2 \ 205-numa node,nodeid=0 -numa node,nodeid=1 \ 206-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 207@end example 208 209@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 210assigns RAM from a given memory backend device to a node. If 211@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 212split equally between them. 213 214@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 215if one node uses @samp{memdev}, all of them have to use it. 216 217@var{source} and @var{destination} are NUMA node IDs. 218@var{distance} is the NUMA distance from @var{source} to @var{destination}. 219The distance from a node to itself is always 10. If any pair of nodes is 220given a distance, then all pairs must be given distances. Although, when 221distances are only given in one direction for each pair of nodes, then 222the distances in the opposite directions are assumed to be the same. If, 223however, an asymmetrical pair of distances is given for even one node 224pair, then all node pairs must be provided distance values for both 225directions, even when they are symmetrical. When a node is unreachable 226from another node, set the pair's distance to 255. 227 228Note that the -@option{numa} option doesn't allocate any of the 229specified resources, it just assigns existing resources to NUMA 230nodes. This means that one still has to use the @option{-m}, 231@option{-smp} options to allocate RAM and VCPUs respectively. 232 233ETEXI 234 235DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 236 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 237 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 238STEXI 239@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 240@findex -add-fd 241 242Add a file descriptor to an fd set. Valid options are: 243 244@table @option 245@item fd=@var{fd} 246This option defines the file descriptor of which a duplicate is added to fd set. 247The file descriptor cannot be stdin, stdout, or stderr. 248@item set=@var{set} 249This option defines the ID of the fd set to add the file descriptor to. 250@item opaque=@var{opaque} 251This option defines a free-form string that can be used to describe @var{fd}. 252@end table 253 254You can open an image using pre-opened file descriptors from an fd set: 255@example 256qemu-system-i386 257-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 258-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 259-drive file=/dev/fdset/2,index=0,media=disk 260@end example 261ETEXI 262 263DEF("set", HAS_ARG, QEMU_OPTION_set, 264 "-set group.id.arg=value\n" 265 " set <arg> parameter for item <id> of type <group>\n" 266 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 267STEXI 268@item -set @var{group}.@var{id}.@var{arg}=@var{value} 269@findex -set 270Set parameter @var{arg} for item @var{id} of type @var{group} 271ETEXI 272 273DEF("global", HAS_ARG, QEMU_OPTION_global, 274 "-global driver.property=value\n" 275 "-global driver=driver,property=property,value=value\n" 276 " set a global default for a driver property\n", 277 QEMU_ARCH_ALL) 278STEXI 279@item -global @var{driver}.@var{prop}=@var{value} 280@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 281@findex -global 282Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 283 284@example 285qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img 286@end example 287 288In particular, you can use this to set driver properties for devices which are 289created automatically by the machine model. To create a device which is not 290created automatically and set properties on it, use -@option{device}. 291 292-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 293driver=@var{driver},property=@var{prop},value=@var{value}. The 294longhand syntax works even when @var{driver} contains a dot. 295ETEXI 296 297DEF("boot", HAS_ARG, QEMU_OPTION_boot, 298 "-boot [order=drives][,once=drives][,menu=on|off]\n" 299 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 300 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 301 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 302 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 303 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 304 QEMU_ARCH_ALL) 305STEXI 306@item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off] 307@findex -boot 308Specify boot order @var{drives} as a string of drive letters. Valid 309drive letters depend on the target architecture. The x86 PC uses: a, b 310(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 311from network adapter 1-4), hard disk boot is the default. To apply a 312particular boot order only on the first startup, specify it via 313@option{once}. Note that the @option{order} or @option{once} parameter 314should not be used together with the @option{bootindex} property of 315devices, since the firmware implementations normally do not support both 316at the same time. 317 318Interactive boot menus/prompts can be enabled via @option{menu=on} as far 319as firmware/BIOS supports them. The default is non-interactive boot. 320 321A splash picture could be passed to bios, enabling user to show it as logo, 322when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 323supports them. Currently Seabios for X86 system support it. 324limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 325format(true color). The resolution should be supported by the SVGA mode, so 326the recommended is 320x240, 640x480, 800x640. 327 328A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 329when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 330reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 331system support it. 332 333Do strict boot via @option{strict=on} as far as firmware/BIOS 334supports it. This only effects when boot priority is changed by 335bootindex options. The default is non-strict boot. 336 337@example 338# try to boot from network first, then from hard disk 339qemu-system-i386 -boot order=nc 340# boot from CD-ROM first, switch back to default order after reboot 341qemu-system-i386 -boot once=d 342# boot with a splash picture for 5 seconds. 343qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 344@end example 345 346Note: The legacy format '-boot @var{drives}' is still supported but its 347use is discouraged as it may be removed from future versions. 348ETEXI 349 350DEF("m", HAS_ARG, QEMU_OPTION_m, 351 "-m [size=]megs[,slots=n,maxmem=size]\n" 352 " configure guest RAM\n" 353 " size: initial amount of guest memory\n" 354 " slots: number of hotplug slots (default: none)\n" 355 " maxmem: maximum amount of guest memory (default: none)\n" 356 "NOTE: Some architectures might enforce a specific granularity\n", 357 QEMU_ARCH_ALL) 358STEXI 359@item -m [size=]@var{megs}[,slots=n,maxmem=size] 360@findex -m 361Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 362Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 363megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 364could be used to set amount of hotpluggable memory slots and maximum amount of 365memory. Note that @var{maxmem} must be aligned to the page size. 366 367For example, the following command-line sets the guest startup RAM size to 3681GB, creates 3 slots to hotplug additional memory and sets the maximum 369memory the guest can reach to 4GB: 370 371@example 372qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 373@end example 374 375If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 376be enabled and the guest startup RAM will never increase. 377ETEXI 378 379DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 380 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 381STEXI 382@item -mem-path @var{path} 383@findex -mem-path 384Allocate guest RAM from a temporarily created file in @var{path}. 385ETEXI 386 387DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 388 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 389 QEMU_ARCH_ALL) 390STEXI 391@item -mem-prealloc 392@findex -mem-prealloc 393Preallocate memory when using -mem-path. 394ETEXI 395 396DEF("k", HAS_ARG, QEMU_OPTION_k, 397 "-k language use keyboard layout (for example 'fr' for French)\n", 398 QEMU_ARCH_ALL) 399STEXI 400@item -k @var{language} 401@findex -k 402Use keyboard layout @var{language} (for example @code{fr} for 403French). This option is only needed where it is not easy to get raw PC 404keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 405display). You don't normally need to use it on PC/Linux or PC/Windows 406hosts. 407 408The available layouts are: 409@example 410ar de-ch es fo fr-ca hu ja mk no pt-br sv 411da en-gb et fr fr-ch is lt nl pl ru th 412de en-us fi fr-be hr it lv nl-be pt sl tr 413@end example 414 415The default is @code{en-us}. 416ETEXI 417 418 419DEF("audio-help", 0, QEMU_OPTION_audio_help, 420 "-audio-help print list of audio drivers and their options\n", 421 QEMU_ARCH_ALL) 422STEXI 423@item -audio-help 424@findex -audio-help 425Will show the audio subsystem help: list of drivers, tunable 426parameters. 427ETEXI 428 429DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 430 "-soundhw c1,... enable audio support\n" 431 " and only specified sound cards (comma separated list)\n" 432 " use '-soundhw help' to get the list of supported cards\n" 433 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 434STEXI 435@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 436@findex -soundhw 437Enable audio and selected sound hardware. Use 'help' to print all 438available sound hardware. 439 440@example 441qemu-system-i386 -soundhw sb16,adlib disk.img 442qemu-system-i386 -soundhw es1370 disk.img 443qemu-system-i386 -soundhw ac97 disk.img 444qemu-system-i386 -soundhw hda disk.img 445qemu-system-i386 -soundhw all disk.img 446qemu-system-i386 -soundhw help 447@end example 448 449Note that Linux's i810_audio OSS kernel (for AC97) module might 450require manually specifying clocking. 451 452@example 453modprobe i810_audio clocking=48000 454@end example 455ETEXI 456 457DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 458 "-balloon virtio[,addr=str]\n" 459 " enable virtio balloon device (deprecated)\n", QEMU_ARCH_ALL) 460STEXI 461@item -balloon virtio[,addr=@var{addr}] 462@findex -balloon 463Enable virtio balloon device, optionally with PCI address @var{addr}. This 464option is deprecated, use @option{-device virtio-balloon} instead. 465ETEXI 466 467DEF("device", HAS_ARG, QEMU_OPTION_device, 468 "-device driver[,prop[=value][,...]]\n" 469 " add device (based on driver)\n" 470 " prop=value,... sets driver properties\n" 471 " use '-device help' to print all possible drivers\n" 472 " use '-device driver,help' to print all possible properties\n", 473 QEMU_ARCH_ALL) 474STEXI 475@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 476@findex -device 477Add device @var{driver}. @var{prop}=@var{value} sets driver 478properties. Valid properties depend on the driver. To get help on 479possible drivers and properties, use @code{-device help} and 480@code{-device @var{driver},help}. 481 482Some drivers are: 483@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}] 484 485Add an IPMI BMC. This is a simulation of a hardware management 486interface processor that normally sits on a system. It provides 487a watchdog and the ability to reset and power control the system. 488You need to connect this to an IPMI interface to make it useful 489 490The IPMI slave address to use for the BMC. The default is 0x20. 491This address is the BMC's address on the I2C network of management 492controllers. If you don't know what this means, it is safe to ignore 493it. 494 495@table @option 496@item bmc=@var{id} 497The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 498@item slave_addr=@var{val} 499Define slave address to use for the BMC. The default is 0x20. 500@item sdrfile=@var{file} 501file containing raw Sensor Data Records (SDR) data. The default is none. 502@item fruareasize=@var{val} 503size of a Field Replaceable Unit (FRU) area. The default is 1024. 504@item frudatafile=@var{file} 505file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 506@end table 507 508@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 509 510Add a connection to an external IPMI BMC simulator. Instead of 511locally emulating the BMC like the above item, instead connect 512to an external entity that provides the IPMI services. 513 514A connection is made to an external BMC simulator. If you do this, it 515is strongly recommended that you use the "reconnect=" chardev option 516to reconnect to the simulator if the connection is lost. Note that if 517this is not used carefully, it can be a security issue, as the 518interface has the ability to send resets, NMIs, and power off the VM. 519It's best if QEMU makes a connection to an external simulator running 520on a secure port on localhost, so neither the simulator nor QEMU is 521exposed to any outside network. 522 523See the "lanserv/README.vm" file in the OpenIPMI library for more 524details on the external interface. 525 526@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 527 528Add a KCS IPMI interafce on the ISA bus. This also adds a 529corresponding ACPI and SMBIOS entries, if appropriate. 530 531@table @option 532@item bmc=@var{id} 533The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 534@item ioport=@var{val} 535Define the I/O address of the interface. The default is 0xca0 for KCS. 536@item irq=@var{val} 537Define the interrupt to use. The default is 5. To disable interrupts, 538set this to 0. 539@end table 540 541@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 542 543Like the KCS interface, but defines a BT interface. The default port is 5440xe4 and the default interrupt is 5. 545 546ETEXI 547 548DEF("name", HAS_ARG, QEMU_OPTION_name, 549 "-name string1[,process=string2][,debug-threads=on|off]\n" 550 " set the name of the guest\n" 551 " string1 sets the window title and string2 the process name (on Linux)\n" 552 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 553 " NOTE: The thread names are for debugging and not a stable API.\n", 554 QEMU_ARCH_ALL) 555STEXI 556@item -name @var{name} 557@findex -name 558Sets the @var{name} of the guest. 559This name will be displayed in the SDL window caption. 560The @var{name} will also be used for the VNC server. 561Also optionally set the top visible process name in Linux. 562Naming of individual threads can also be enabled on Linux to aid debugging. 563ETEXI 564 565DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 566 "-uuid %08x-%04x-%04x-%04x-%012x\n" 567 " specify machine UUID\n", QEMU_ARCH_ALL) 568STEXI 569@item -uuid @var{uuid} 570@findex -uuid 571Set system UUID. 572ETEXI 573 574STEXI 575@end table 576ETEXI 577DEFHEADING() 578 579DEFHEADING(Block device options:) 580STEXI 581@table @option 582ETEXI 583 584DEF("fda", HAS_ARG, QEMU_OPTION_fda, 585 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 586DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 587STEXI 588@item -fda @var{file} 589@itemx -fdb @var{file} 590@findex -fda 591@findex -fdb 592Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 593ETEXI 594 595DEF("hda", HAS_ARG, QEMU_OPTION_hda, 596 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 597DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 598DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 599 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 600DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 601STEXI 602@item -hda @var{file} 603@itemx -hdb @var{file} 604@itemx -hdc @var{file} 605@itemx -hdd @var{file} 606@findex -hda 607@findex -hdb 608@findex -hdc 609@findex -hdd 610Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 611ETEXI 612 613DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 614 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 615 QEMU_ARCH_ALL) 616STEXI 617@item -cdrom @var{file} 618@findex -cdrom 619Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 620@option{-cdrom} at the same time). You can use the host CD-ROM by 621using @file{/dev/cdrom} as filename (@pxref{host_drives}). 622ETEXI 623 624DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 625 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 626 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 627 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n" 628 " [,driver specific parameters...]\n" 629 " configure a block backend\n", QEMU_ARCH_ALL) 630STEXI 631@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 632@findex -blockdev 633 634Define a new block driver node. Some of the options apply to all block drivers, 635other options are only accepted for a specific block driver. See below for a 636list of generic options and options for the most common block drivers. 637 638Options that expect a reference to another node (e.g. @code{file}) can be 639given in two ways. Either you specify the node name of an already existing node 640(file=@var{node-name}), or you define a new node inline, adding options 641for the referenced node after a dot (file.filename=@var{path},file.aio=native). 642 643A block driver node created with @option{-blockdev} can be used for a guest 644device by specifying its node name for the @code{drive} property in a 645@option{-device} argument that defines a block device. 646 647@table @option 648@item Valid options for any block driver node: 649 650@table @code 651@item driver 652Specifies the block driver to use for the given node. 653@item node-name 654This defines the name of the block driver node by which it will be referenced 655later. The name must be unique, i.e. it must not match the name of a different 656block driver node, or (if you use @option{-drive} as well) the ID of a drive. 657 658If no node name is specified, it is automatically generated. The generated node 659name is not intended to be predictable and changes between QEMU invocations. 660For the top level, an explicit node name must be specified. 661@item read-only 662Open the node read-only. Guest write attempts will fail. 663@item cache.direct 664The host page cache can be avoided with @option{cache.direct=on}. This will 665attempt to do disk IO directly to the guest's memory. QEMU may still perform an 666internal copy of the data. 667@item cache.no-flush 668In case you don't care about data integrity over host failures, you can use 669@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 670any data to the disk but can instead keep things in cache. If anything goes 671wrong, like your host losing power, the disk storage getting disconnected 672accidentally, etc. your image will most probably be rendered unusable. 673@item discard=@var{discard} 674@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 675whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 676ignored or passed to the filesystem. Some machine types may not support 677discard requests. 678@item detect-zeroes=@var{detect-zeroes} 679@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 680conversion of plain zero writes by the OS to driver specific optimized 681zero write commands. You may even choose "unmap" if @var{discard} is set 682to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 683@end table 684 685@item Driver-specific options for @code{file} 686 687This is the protocol-level block driver for accessing regular files. 688 689@table @code 690@item filename 691The path to the image file in the local filesystem 692@item aio 693Specifies the AIO backend (threads/native, default: threads) 694@item locking 695Specifies whether the image file is protected with Linux OFD / POSIX locks. The 696default is to use the Linux Open File Descriptor API if available, otherwise no 697lock is applied. (auto/on/off, default: auto) 698@end table 699Example: 700@example 701-blockdev driver=file,node-name=disk,filename=disk.img 702@end example 703 704@item Driver-specific options for @code{raw} 705 706This is the image format block driver for raw images. It is usually 707stacked on top of a protocol level block driver such as @code{file}. 708 709@table @code 710@item file 711Reference to or definition of the data source block driver node 712(e.g. a @code{file} driver node) 713@end table 714Example 1: 715@example 716-blockdev driver=file,node-name=disk_file,filename=disk.img 717-blockdev driver=raw,node-name=disk,file=disk_file 718@end example 719Example 2: 720@example 721-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 722@end example 723 724@item Driver-specific options for @code{qcow2} 725 726This is the image format block driver for qcow2 images. It is usually 727stacked on top of a protocol level block driver such as @code{file}. 728 729@table @code 730@item file 731Reference to or definition of the data source block driver node 732(e.g. a @code{file} driver node) 733 734@item backing 735Reference to or definition of the backing file block device (default is taken 736from the image file). It is allowed to pass @code{null} here in order to disable 737the default backing file. 738 739@item lazy-refcounts 740Whether to enable the lazy refcounts feature (on/off; default is taken from the 741image file) 742 743@item cache-size 744The maximum total size of the L2 table and refcount block caches in bytes 745(default: 1048576 bytes or 8 clusters, whichever is larger) 746 747@item l2-cache-size 748The maximum size of the L2 table cache in bytes 749(default: 4/5 of the total cache size) 750 751@item refcount-cache-size 752The maximum size of the refcount block cache in bytes 753(default: 1/5 of the total cache size) 754 755@item cache-clean-interval 756Clean unused entries in the L2 and refcount caches. The interval is in seconds. 757The default value is 0 and it disables this feature. 758 759@item pass-discard-request 760Whether discard requests to the qcow2 device should be forwarded to the data 761source (on/off; default: on if discard=unmap is specified, off otherwise) 762 763@item pass-discard-snapshot 764Whether discard requests for the data source should be issued when a snapshot 765operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 766default: on) 767 768@item pass-discard-other 769Whether discard requests for the data source should be issued on other 770occasions where a cluster gets freed (on/off; default: off) 771 772@item overlap-check 773Which overlap checks to perform for writes to the image 774(none/constant/cached/all; default: cached). For details or finer 775granularity control refer to the QAPI documentation of @code{blockdev-add}. 776@end table 777 778Example 1: 779@example 780-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 781-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 782@end example 783Example 2: 784@example 785-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 786@end example 787 788@item Driver-specific options for other drivers 789Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 790 791@end table 792 793ETEXI 794 795DEF("drive", HAS_ARG, QEMU_OPTION_drive, 796 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 797 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 798 " [,snapshot=on|off][,rerror=ignore|stop|report]\n" 799 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 800 " [,readonly=on|off][,copy-on-read=on|off]\n" 801 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 802 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 803 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 804 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 805 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 806 " [[,iops_size=is]]\n" 807 " [[,group=g]]\n" 808 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 809STEXI 810@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 811@findex -drive 812 813Define a new drive. This includes creating a block driver node (the backend) as 814well as a guest device, and is mostly a shortcut for defining the corresponding 815@option{-blockdev} and @option{-device} options. 816 817@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 818addition, it knows the following options: 819 820@table @option 821@item file=@var{file} 822This option defines which disk image (@pxref{disk_images}) to use with 823this drive. If the filename contains comma, you must double it 824(for instance, "file=my,,file" to use file "my,file"). 825 826Special files such as iSCSI devices can be specified using protocol 827specific URLs. See the section for "Device URL Syntax" for more information. 828@item if=@var{interface} 829This option defines on which type on interface the drive is connected. 830Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 831@item bus=@var{bus},unit=@var{unit} 832These options define where is connected the drive by defining the bus number and 833the unit id. 834@item index=@var{index} 835This option defines where is connected the drive by using an index in the list 836of available connectors of a given interface type. 837@item media=@var{media} 838This option defines the type of the media: disk or cdrom. 839@item snapshot=@var{snapshot} 840@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 841(see @option{-snapshot}). 842@item cache=@var{cache} 843@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 844and controls how the host cache is used to access block data. This is a 845shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 846options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 847which provides a default for the @option{write-cache} option of block guest 848devices (as in @option{-device}). The modes correspond to the following 849settings: 850 851@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 852@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 853@c and the HTML output. 854@example 855@ │ cache.writeback cache.direct cache.no-flush 856─────────────┼───────────────────────────────────────────────── 857writeback │ on off off 858none │ on on off 859writethrough │ off off off 860directsync │ off on off 861unsafe │ on off on 862@end example 863 864The default mode is @option{cache=writeback}. 865 866@item aio=@var{aio} 867@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 868@item format=@var{format} 869Specify which disk @var{format} will be used rather than detecting 870the format. Can be used to specify format=raw to avoid interpreting 871an untrusted format header. 872@item werror=@var{action},rerror=@var{action} 873Specify which @var{action} to take on write and read errors. Valid actions are: 874"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 875"report" (report the error to the guest), "enospc" (pause QEMU only if the 876host disk is full; report the error to the guest otherwise). 877The default setting is @option{werror=enospc} and @option{rerror=report}. 878@item copy-on-read=@var{copy-on-read} 879@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 880file sectors into the image file. 881@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 882Specify bandwidth throttling limits in bytes per second, either for all request 883types or for reads or writes only. Small values can lead to timeouts or hangs 884inside the guest. A safe minimum for disks is 2 MB/s. 885@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 886Specify bursts in bytes per second, either for all request types or for reads 887or writes only. Bursts allow the guest I/O to spike above the limit 888temporarily. 889@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 890Specify request rate limits in requests per second, either for all request 891types or for reads or writes only. 892@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 893Specify bursts in requests per second, either for all request types or for reads 894or writes only. Bursts allow the guest I/O to spike above the limit 895temporarily. 896@item iops_size=@var{is} 897Let every @var{is} bytes of a request count as a new request for iops 898throttling purposes. Use this option to prevent guests from circumventing iops 899limits by sending fewer but larger requests. 900@item group=@var{g} 901Join a throttling quota group with given name @var{g}. All drives that are 902members of the same group are accounted for together. Use this option to 903prevent guests from circumventing throttling limits by using many small disks 904instead of a single larger disk. 905@end table 906 907By default, the @option{cache.writeback=on} mode is used. It will report data 908writes as completed as soon as the data is present in the host page cache. 909This is safe as long as your guest OS makes sure to correctly flush disk caches 910where needed. If your guest OS does not handle volatile disk write caches 911correctly and your host crashes or loses power, then the guest may experience 912data corruption. 913 914For such guests, you should consider using @option{cache.writeback=off}. This 915means that the host page cache will be used to read and write data, but write 916notification will be sent to the guest only after QEMU has made sure to flush 917each write to the disk. Be aware that this has a major impact on performance. 918 919When using the @option{-snapshot} option, unsafe caching is always used. 920 921Copy-on-read avoids accessing the same backing file sectors repeatedly and is 922useful when the backing file is over a slow network. By default copy-on-read 923is off. 924 925Instead of @option{-cdrom} you can use: 926@example 927qemu-system-i386 -drive file=file,index=2,media=cdrom 928@end example 929 930Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 931use: 932@example 933qemu-system-i386 -drive file=file,index=0,media=disk 934qemu-system-i386 -drive file=file,index=1,media=disk 935qemu-system-i386 -drive file=file,index=2,media=disk 936qemu-system-i386 -drive file=file,index=3,media=disk 937@end example 938 939You can open an image using pre-opened file descriptors from an fd set: 940@example 941qemu-system-i386 942-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 943-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 944-drive file=/dev/fdset/2,index=0,media=disk 945@end example 946 947You can connect a CDROM to the slave of ide0: 948@example 949qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 950@end example 951 952If you don't specify the "file=" argument, you define an empty drive: 953@example 954qemu-system-i386 -drive if=ide,index=1,media=cdrom 955@end example 956 957Instead of @option{-fda}, @option{-fdb}, you can use: 958@example 959qemu-system-i386 -drive file=file,index=0,if=floppy 960qemu-system-i386 -drive file=file,index=1,if=floppy 961@end example 962 963By default, @var{interface} is "ide" and @var{index} is automatically 964incremented: 965@example 966qemu-system-i386 -drive file=a -drive file=b" 967@end example 968is interpreted like: 969@example 970qemu-system-i386 -hda a -hdb b 971@end example 972ETEXI 973 974DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 975 "-mtdblock file use 'file' as on-board Flash memory image\n", 976 QEMU_ARCH_ALL) 977STEXI 978@item -mtdblock @var{file} 979@findex -mtdblock 980Use @var{file} as on-board Flash memory image. 981ETEXI 982 983DEF("sd", HAS_ARG, QEMU_OPTION_sd, 984 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 985STEXI 986@item -sd @var{file} 987@findex -sd 988Use @var{file} as SecureDigital card image. 989ETEXI 990 991DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 992 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 993STEXI 994@item -pflash @var{file} 995@findex -pflash 996Use @var{file} as a parallel flash image. 997ETEXI 998 999DEF("snapshot", 0, QEMU_OPTION_snapshot, 1000 "-snapshot write to temporary files instead of disk image files\n", 1001 QEMU_ARCH_ALL) 1002STEXI 1003@item -snapshot 1004@findex -snapshot 1005Write to temporary files instead of disk image files. In this case, 1006the raw disk image you use is not written back. You can however force 1007the write back by pressing @key{C-a s} (@pxref{disk_images}). 1008ETEXI 1009 1010DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1011 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 1012 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n" 1013 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1014 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1015 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1016 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1017 " [[,throttling.iops-size=is]]\n", 1018 QEMU_ARCH_ALL) 1019 1020STEXI 1021 1022@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}] 1023@findex -fsdev 1024Define a new file system device. Valid options are: 1025@table @option 1026@item @var{fsdriver} 1027This option specifies the fs driver backend to use. 1028Currently "local", "handle" and "proxy" file system drivers are supported. 1029@item id=@var{id} 1030Specifies identifier for this device 1031@item path=@var{path} 1032Specifies the export path for the file system device. Files under 1033this path will be available to the 9p client on the guest. 1034@item security_model=@var{security_model} 1035Specifies the security model to be used for this export path. 1036Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1037In "passthrough" security model, files are stored using the same 1038credentials as they are created on the guest. This requires QEMU 1039to run as root. In "mapped-xattr" security model, some of the file 1040attributes like uid, gid, mode bits and link target are stored as 1041file attributes. For "mapped-file" these attributes are stored in the 1042hidden .virtfs_metadata directory. Directories exported by this security model cannot 1043interact with other unix tools. "none" security model is same as 1044passthrough except the sever won't report failures if it fails to 1045set file attributes like ownership. Security model is mandatory 1046only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 1047security model as a parameter. 1048@item writeout=@var{writeout} 1049This is an optional argument. The only supported value is "immediate". 1050This means that host page cache will be used to read and write data but 1051write notification will be sent to the guest only when the data has been 1052reported as written by the storage subsystem. 1053@item readonly 1054Enables exporting 9p share as a readonly mount for guests. By default 1055read-write access is given. 1056@item socket=@var{socket} 1057Enables proxy filesystem driver to use passed socket file for communicating 1058with virtfs-proxy-helper 1059@item sock_fd=@var{sock_fd} 1060Enables proxy filesystem driver to use passed socket descriptor for 1061communicating with virtfs-proxy-helper. Usually a helper like libvirt 1062will create socketpair and pass one of the fds as sock_fd 1063@item fmode=@var{fmode} 1064Specifies the default mode for newly created files on the host. Works only 1065with security models "mapped-xattr" and "mapped-file". 1066@item dmode=@var{dmode} 1067Specifies the default mode for newly created directories on the host. Works 1068only with security models "mapped-xattr" and "mapped-file". 1069@end table 1070 1071-fsdev option is used along with -device driver "virtio-9p-pci". 1072@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 1073Options for virtio-9p-pci driver are: 1074@table @option 1075@item fsdev=@var{id} 1076Specifies the id value specified along with -fsdev option 1077@item mount_tag=@var{mount_tag} 1078Specifies the tag name to be used by the guest to mount this export point 1079@end table 1080 1081ETEXI 1082 1083DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1084 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 1085 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n", 1086 QEMU_ARCH_ALL) 1087 1088STEXI 1089 1090@item -virtfs @var{fsdriver}[,path=@var{path}],mount_tag=@var{mount_tag}[,security_model=@var{security_model}][,writeout=@var{writeout}][,readonly][,socket=@var{socket}|sock_fd=@var{sock_fd}][,fmode=@var{fmode}][,dmode=@var{dmode}] 1091@findex -virtfs 1092 1093The general form of a Virtual File system pass-through options are: 1094@table @option 1095@item @var{fsdriver} 1096This option specifies the fs driver backend to use. 1097Currently "local", "handle" and "proxy" file system drivers are supported. 1098@item id=@var{id} 1099Specifies identifier for this device 1100@item path=@var{path} 1101Specifies the export path for the file system device. Files under 1102this path will be available to the 9p client on the guest. 1103@item security_model=@var{security_model} 1104Specifies the security model to be used for this export path. 1105Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1106In "passthrough" security model, files are stored using the same 1107credentials as they are created on the guest. This requires QEMU 1108to run as root. In "mapped-xattr" security model, some of the file 1109attributes like uid, gid, mode bits and link target are stored as 1110file attributes. For "mapped-file" these attributes are stored in the 1111hidden .virtfs_metadata directory. Directories exported by this security model cannot 1112interact with other unix tools. "none" security model is same as 1113passthrough except the sever won't report failures if it fails to 1114set file attributes like ownership. Security model is mandatory only 1115for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 1116model as a parameter. 1117@item writeout=@var{writeout} 1118This is an optional argument. The only supported value is "immediate". 1119This means that host page cache will be used to read and write data but 1120write notification will be sent to the guest only when the data has been 1121reported as written by the storage subsystem. 1122@item readonly 1123Enables exporting 9p share as a readonly mount for guests. By default 1124read-write access is given. 1125@item socket=@var{socket} 1126Enables proxy filesystem driver to use passed socket file for 1127communicating with virtfs-proxy-helper. Usually a helper like libvirt 1128will create socketpair and pass one of the fds as sock_fd 1129@item sock_fd 1130Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1131descriptor for interfacing with virtfs-proxy-helper 1132@item fmode=@var{fmode} 1133Specifies the default mode for newly created files on the host. Works only 1134with security models "mapped-xattr" and "mapped-file". 1135@item dmode=@var{dmode} 1136Specifies the default mode for newly created directories on the host. Works 1137only with security models "mapped-xattr" and "mapped-file". 1138@end table 1139ETEXI 1140 1141DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1142 "-virtfs_synth Create synthetic file system image\n", 1143 QEMU_ARCH_ALL) 1144STEXI 1145@item -virtfs_synth 1146@findex -virtfs_synth 1147Create synthetic file system image 1148ETEXI 1149 1150DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 1151 "-iscsi [user=user][,password=password]\n" 1152 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 1153 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 1154 " [,timeout=timeout]\n" 1155 " iSCSI session parameters\n", QEMU_ARCH_ALL) 1156 1157STEXI 1158@item -iscsi 1159@findex -iscsi 1160Configure iSCSI session parameters. 1161ETEXI 1162 1163STEXI 1164@end table 1165ETEXI 1166DEFHEADING() 1167 1168DEFHEADING(USB options:) 1169STEXI 1170@table @option 1171ETEXI 1172 1173DEF("usb", 0, QEMU_OPTION_usb, 1174 "-usb enable the USB driver (if it is not used by default yet)\n", 1175 QEMU_ARCH_ALL) 1176STEXI 1177@item -usb 1178@findex -usb 1179Enable the USB driver (if it is not used by default yet). 1180ETEXI 1181 1182DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1183 "-usbdevice name add the host or guest USB device 'name'\n", 1184 QEMU_ARCH_ALL) 1185STEXI 1186 1187@item -usbdevice @var{devname} 1188@findex -usbdevice 1189Add the USB device @var{devname}. Note that this option is deprecated, 1190please use @code{-device usb-...} instead. @xref{usb_devices}. 1191 1192@table @option 1193 1194@item mouse 1195Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1196 1197@item tablet 1198Pointer device that uses absolute coordinates (like a touchscreen). This 1199means QEMU is able to report the mouse position without having to grab the 1200mouse. Also overrides the PS/2 mouse emulation when activated. 1201 1202@item braille 1203Braille device. This will use BrlAPI to display the braille output on a real 1204or fake device. 1205 1206@end table 1207ETEXI 1208 1209STEXI 1210@end table 1211ETEXI 1212DEFHEADING() 1213 1214DEFHEADING(Display options:) 1215STEXI 1216@table @option 1217ETEXI 1218 1219DEF("display", HAS_ARG, QEMU_OPTION_display, 1220 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1221 " [,window_close=on|off][,gl=on|core|es|off]\n" 1222 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1223 "-display vnc=<display>[,<optargs>]\n" 1224 "-display curses\n" 1225 "-display none" 1226 " select display type\n" 1227 "The default display is equivalent to\n" 1228#if defined(CONFIG_GTK) 1229 "\t\"-display gtk\"\n" 1230#elif defined(CONFIG_SDL) 1231 "\t\"-display sdl\"\n" 1232#elif defined(CONFIG_COCOA) 1233 "\t\"-display cocoa\"\n" 1234#elif defined(CONFIG_VNC) 1235 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1236#else 1237 "\t\"-display none\"\n" 1238#endif 1239 , QEMU_ARCH_ALL) 1240STEXI 1241@item -display @var{type} 1242@findex -display 1243Select type of display to use. This option is a replacement for the 1244old style -sdl/-curses/... options. Valid values for @var{type} are 1245@table @option 1246@item sdl 1247Display video output via SDL (usually in a separate graphics 1248window; see the SDL documentation for other possibilities). 1249@item curses 1250Display video output via curses. For graphics device models which 1251support a text mode, QEMU can display this output using a 1252curses/ncurses interface. Nothing is displayed when the graphics 1253device is in graphical mode or if the graphics device does not support 1254a text mode. Generally only the VGA device models support text mode. 1255@item none 1256Do not display video output. The guest will still see an emulated 1257graphics card, but its output will not be displayed to the QEMU 1258user. This option differs from the -nographic option in that it 1259only affects what is done with video output; -nographic also changes 1260the destination of the serial and parallel port data. 1261@item gtk 1262Display video output in a GTK window. This interface provides drop-down 1263menus and other UI elements to configure and control the VM during 1264runtime. 1265@item vnc 1266Start a VNC server on display <arg> 1267@end table 1268ETEXI 1269 1270DEF("nographic", 0, QEMU_OPTION_nographic, 1271 "-nographic disable graphical output and redirect serial I/Os to console\n", 1272 QEMU_ARCH_ALL) 1273STEXI 1274@item -nographic 1275@findex -nographic 1276Normally, if QEMU is compiled with graphical window support, it displays 1277output such as guest graphics, guest console, and the QEMU monitor in a 1278window. With this option, you can totally disable graphical output so 1279that QEMU is a simple command line application. The emulated serial port 1280is redirected on the console and muxed with the monitor (unless 1281redirected elsewhere explicitly). Therefore, you can still use QEMU to 1282debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1283switching between the console and monitor. 1284ETEXI 1285 1286DEF("curses", 0, QEMU_OPTION_curses, 1287 "-curses shorthand for -display curses\n", 1288 QEMU_ARCH_ALL) 1289STEXI 1290@item -curses 1291@findex -curses 1292Normally, if QEMU is compiled with graphical window support, it displays 1293output such as guest graphics, guest console, and the QEMU monitor in a 1294window. With this option, QEMU can display the VGA output when in text 1295mode using a curses/ncurses interface. Nothing is displayed in graphical 1296mode. 1297ETEXI 1298 1299DEF("no-frame", 0, QEMU_OPTION_no_frame, 1300 "-no-frame open SDL window without a frame and window decorations\n", 1301 QEMU_ARCH_ALL) 1302STEXI 1303@item -no-frame 1304@findex -no-frame 1305Do not use decorations for SDL windows and start them using the whole 1306available screen space. This makes the using QEMU in a dedicated desktop 1307workspace more convenient. 1308ETEXI 1309 1310DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1311 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1312 QEMU_ARCH_ALL) 1313STEXI 1314@item -alt-grab 1315@findex -alt-grab 1316Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1317affects the special keys (for fullscreen, monitor-mode switching, etc). 1318ETEXI 1319 1320DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1321 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1322 QEMU_ARCH_ALL) 1323STEXI 1324@item -ctrl-grab 1325@findex -ctrl-grab 1326Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1327affects the special keys (for fullscreen, monitor-mode switching, etc). 1328ETEXI 1329 1330DEF("no-quit", 0, QEMU_OPTION_no_quit, 1331 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1332STEXI 1333@item -no-quit 1334@findex -no-quit 1335Disable SDL window close capability. 1336ETEXI 1337 1338DEF("sdl", 0, QEMU_OPTION_sdl, 1339 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1340STEXI 1341@item -sdl 1342@findex -sdl 1343Enable SDL. 1344ETEXI 1345 1346DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1347 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1348 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1349 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1350 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1351 " [,tls-ciphers=<list>]\n" 1352 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1353 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1354 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1355 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1356 " [,jpeg-wan-compression=[auto|never|always]]\n" 1357 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1358 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1359 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1360 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1361 " [,gl=[on|off]][,rendernode=<file>]\n" 1362 " enable spice\n" 1363 " at least one of {port, tls-port} is mandatory\n", 1364 QEMU_ARCH_ALL) 1365STEXI 1366@item -spice @var{option}[,@var{option}[,...]] 1367@findex -spice 1368Enable the spice remote desktop protocol. Valid options are 1369 1370@table @option 1371 1372@item port=<nr> 1373Set the TCP port spice is listening on for plaintext channels. 1374 1375@item addr=<addr> 1376Set the IP address spice is listening on. Default is any address. 1377 1378@item ipv4 1379@itemx ipv6 1380@itemx unix 1381Force using the specified IP version. 1382 1383@item password=<secret> 1384Set the password you need to authenticate. 1385 1386@item sasl 1387Require that the client use SASL to authenticate with the spice. 1388The exact choice of authentication method used is controlled from the 1389system / user's SASL configuration file for the 'qemu' service. This 1390is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1391unprivileged user, an environment variable SASL_CONF_PATH can be used 1392to make it search alternate locations for the service config. 1393While some SASL auth methods can also provide data encryption (eg GSSAPI), 1394it is recommended that SASL always be combined with the 'tls' and 1395'x509' settings to enable use of SSL and server certificates. This 1396ensures a data encryption preventing compromise of authentication 1397credentials. 1398 1399@item disable-ticketing 1400Allow client connects without authentication. 1401 1402@item disable-copy-paste 1403Disable copy paste between the client and the guest. 1404 1405@item disable-agent-file-xfer 1406Disable spice-vdagent based file-xfer between the client and the guest. 1407 1408@item tls-port=<nr> 1409Set the TCP port spice is listening on for encrypted channels. 1410 1411@item x509-dir=<dir> 1412Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1413 1414@item x509-key-file=<file> 1415@itemx x509-key-password=<file> 1416@itemx x509-cert-file=<file> 1417@itemx x509-cacert-file=<file> 1418@itemx x509-dh-key-file=<file> 1419The x509 file names can also be configured individually. 1420 1421@item tls-ciphers=<list> 1422Specify which ciphers to use. 1423 1424@item tls-channel=[main|display|cursor|inputs|record|playback] 1425@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1426Force specific channel to be used with or without TLS encryption. The 1427options can be specified multiple times to configure multiple 1428channels. The special name "default" can be used to set the default 1429mode. For channels which are not explicitly forced into one mode the 1430spice client is allowed to pick tls/plaintext as he pleases. 1431 1432@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1433Configure image compression (lossless). 1434Default is auto_glz. 1435 1436@item jpeg-wan-compression=[auto|never|always] 1437@itemx zlib-glz-wan-compression=[auto|never|always] 1438Configure wan image compression (lossy for slow links). 1439Default is auto. 1440 1441@item streaming-video=[off|all|filter] 1442Configure video stream detection. Default is off. 1443 1444@item agent-mouse=[on|off] 1445Enable/disable passing mouse events via vdagent. Default is on. 1446 1447@item playback-compression=[on|off] 1448Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1449 1450@item seamless-migration=[on|off] 1451Enable/disable spice seamless migration. Default is off. 1452 1453@item gl=[on|off] 1454Enable/disable OpenGL context. Default is off. 1455 1456@item rendernode=<file> 1457DRM render node for OpenGL rendering. If not specified, it will pick 1458the first available. (Since 2.9) 1459 1460@end table 1461ETEXI 1462 1463DEF("portrait", 0, QEMU_OPTION_portrait, 1464 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1465 QEMU_ARCH_ALL) 1466STEXI 1467@item -portrait 1468@findex -portrait 1469Rotate graphical output 90 deg left (only PXA LCD). 1470ETEXI 1471 1472DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1473 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1474 QEMU_ARCH_ALL) 1475STEXI 1476@item -rotate @var{deg} 1477@findex -rotate 1478Rotate graphical output some deg left (only PXA LCD). 1479ETEXI 1480 1481DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1482 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1483 " select video card type\n", QEMU_ARCH_ALL) 1484STEXI 1485@item -vga @var{type} 1486@findex -vga 1487Select type of VGA card to emulate. Valid values for @var{type} are 1488@table @option 1489@item cirrus 1490Cirrus Logic GD5446 Video card. All Windows versions starting from 1491Windows 95 should recognize and use this graphic card. For optimal 1492performances, use 16 bit color depth in the guest and the host OS. 1493(This card was the default before QEMU 2.2) 1494@item std 1495Standard VGA card with Bochs VBE extensions. If your guest OS 1496supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1497to use high resolution modes (>= 1280x1024x16) then you should use 1498this option. (This card is the default since QEMU 2.2) 1499@item vmware 1500VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1501recent XFree86/XOrg server or Windows guest with a driver for this 1502card. 1503@item qxl 1504QXL paravirtual graphic card. It is VGA compatible (including VESA 15052.0 VBE support). Works best with qxl guest drivers installed though. 1506Recommended choice when using the spice protocol. 1507@item tcx 1508(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1509sun4m machines and offers both 8-bit and 24-bit colour depths at a 1510fixed resolution of 1024x768. 1511@item cg3 1512(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1513for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1514resolutions aimed at people wishing to run older Solaris versions. 1515@item virtio 1516Virtio VGA card. 1517@item none 1518Disable VGA card. 1519@end table 1520ETEXI 1521 1522DEF("full-screen", 0, QEMU_OPTION_full_screen, 1523 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1524STEXI 1525@item -full-screen 1526@findex -full-screen 1527Start in full screen. 1528ETEXI 1529 1530DEF("g", 1, QEMU_OPTION_g , 1531 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1532 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1533STEXI 1534@item -g @var{width}x@var{height}[x@var{depth}] 1535@findex -g 1536Set the initial graphical resolution and depth (PPC, SPARC only). 1537ETEXI 1538 1539DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1540 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1541STEXI 1542@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1543@findex -vnc 1544Normally, if QEMU is compiled with graphical window support, it displays 1545output such as guest graphics, guest console, and the QEMU monitor in a 1546window. With this option, you can have QEMU listen on VNC display 1547@var{display} and redirect the VGA display over the VNC session. It is 1548very useful to enable the usb tablet device when using this option 1549(option @option{-device usb-tablet}). When using the VNC display, you 1550must use the @option{-k} parameter to set the keyboard layout if you are 1551not using en-us. Valid syntax for the @var{display} is 1552 1553@table @option 1554 1555@item to=@var{L} 1556 1557With this option, QEMU will try next available VNC @var{display}s, until the 1558number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1559available, e.g. port 5900+@var{display} is already used by another 1560application. By default, to=0. 1561 1562@item @var{host}:@var{d} 1563 1564TCP connections will only be allowed from @var{host} on display @var{d}. 1565By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1566be omitted in which case the server will accept connections from any host. 1567 1568@item unix:@var{path} 1569 1570Connections will be allowed over UNIX domain sockets where @var{path} is the 1571location of a unix socket to listen for connections on. 1572 1573@item none 1574 1575VNC is initialized but not started. The monitor @code{change} command 1576can be used to later start the VNC server. 1577 1578@end table 1579 1580Following the @var{display} value there may be one or more @var{option} flags 1581separated by commas. Valid options are 1582 1583@table @option 1584 1585@item reverse 1586 1587Connect to a listening VNC client via a ``reverse'' connection. The 1588client is specified by the @var{display}. For reverse network 1589connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1590is a TCP port number, not a display number. 1591 1592@item websocket 1593 1594Opens an additional TCP listening port dedicated to VNC Websocket connections. 1595If a bare @var{websocket} option is given, the Websocket port is 15965700+@var{display}. An alternative port can be specified with the 1597syntax @code{websocket}=@var{port}. 1598 1599If @var{host} is specified connections will only be allowed from this host. 1600It is possible to control the websocket listen address independently, using 1601the syntax @code{websocket}=@var{host}:@var{port}. 1602 1603If no TLS credentials are provided, the websocket connection runs in 1604unencrypted mode. If TLS credentials are provided, the websocket connection 1605requires encrypted client connections. 1606 1607@item password 1608 1609Require that password based authentication is used for client connections. 1610 1611The password must be set separately using the @code{set_password} command in 1612the @ref{pcsys_monitor}. The syntax to change your password is: 1613@code{set_password <protocol> <password>} where <protocol> could be either 1614"vnc" or "spice". 1615 1616If you would like to change <protocol> password expiration, you should use 1617@code{expire_password <protocol> <expiration-time>} where expiration time could 1618be one of the following options: now, never, +seconds or UNIX time of 1619expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1620to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1621date and time). 1622 1623You can also use keywords "now" or "never" for the expiration time to 1624allow <protocol> password to expire immediately or never expire. 1625 1626@item tls-creds=@var{ID} 1627 1628Provides the ID of a set of TLS credentials to use to secure the 1629VNC server. They will apply to both the normal VNC server socket 1630and the websocket socket (if enabled). Setting TLS credentials 1631will cause the VNC server socket to enable the VeNCrypt auth 1632mechanism. The credentials should have been previously created 1633using the @option{-object tls-creds} argument. 1634 1635The @option{tls-creds} parameter obsoletes the @option{tls}, 1636@option{x509}, and @option{x509verify} options, and as such 1637it is not permitted to set both new and old type options at 1638the same time. 1639 1640@item tls 1641 1642Require that client use TLS when communicating with the VNC server. This 1643uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1644attack. It is recommended that this option be combined with either the 1645@option{x509} or @option{x509verify} options. 1646 1647This option is now deprecated in favor of using the @option{tls-creds} 1648argument. 1649 1650@item x509=@var{/path/to/certificate/dir} 1651 1652Valid if @option{tls} is specified. Require that x509 credentials are used 1653for negotiating the TLS session. The server will send its x509 certificate 1654to the client. It is recommended that a password be set on the VNC server 1655to provide authentication of the client when this is used. The path following 1656this option specifies where the x509 certificates are to be loaded from. 1657See the @ref{vnc_security} section for details on generating certificates. 1658 1659This option is now deprecated in favour of using the @option{tls-creds} 1660argument. 1661 1662@item x509verify=@var{/path/to/certificate/dir} 1663 1664Valid if @option{tls} is specified. Require that x509 credentials are used 1665for negotiating the TLS session. The server will send its x509 certificate 1666to the client, and request that the client send its own x509 certificate. 1667The server will validate the client's certificate against the CA certificate, 1668and reject clients when validation fails. If the certificate authority is 1669trusted, this is a sufficient authentication mechanism. You may still wish 1670to set a password on the VNC server as a second authentication layer. The 1671path following this option specifies where the x509 certificates are to 1672be loaded from. See the @ref{vnc_security} section for details on generating 1673certificates. 1674 1675This option is now deprecated in favour of using the @option{tls-creds} 1676argument. 1677 1678@item sasl 1679 1680Require that the client use SASL to authenticate with the VNC server. 1681The exact choice of authentication method used is controlled from the 1682system / user's SASL configuration file for the 'qemu' service. This 1683is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1684unprivileged user, an environment variable SASL_CONF_PATH can be used 1685to make it search alternate locations for the service config. 1686While some SASL auth methods can also provide data encryption (eg GSSAPI), 1687it is recommended that SASL always be combined with the 'tls' and 1688'x509' settings to enable use of SSL and server certificates. This 1689ensures a data encryption preventing compromise of authentication 1690credentials. See the @ref{vnc_security} section for details on using 1691SASL authentication. 1692 1693@item acl 1694 1695Turn on access control lists for checking of the x509 client certificate 1696and SASL party. For x509 certs, the ACL check is made against the 1697certificate's distinguished name. This is something that looks like 1698@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1699made against the username, which depending on the SASL plugin, may 1700include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1701When the @option{acl} flag is set, the initial access list will be 1702empty, with a @code{deny} policy. Thus no one will be allowed to 1703use the VNC server until the ACLs have been loaded. This can be 1704achieved using the @code{acl} monitor command. 1705 1706@item lossy 1707 1708Enable lossy compression methods (gradient, JPEG, ...). If this 1709option is set, VNC client may receive lossy framebuffer updates 1710depending on its encoding settings. Enabling this option can save 1711a lot of bandwidth at the expense of quality. 1712 1713@item non-adaptive 1714 1715Disable adaptive encodings. Adaptive encodings are enabled by default. 1716An adaptive encoding will try to detect frequently updated screen regions, 1717and send updates in these regions using a lossy encoding (like JPEG). 1718This can be really helpful to save bandwidth when playing videos. Disabling 1719adaptive encodings restores the original static behavior of encodings 1720like Tight. 1721 1722@item share=[allow-exclusive|force-shared|ignore] 1723 1724Set display sharing policy. 'allow-exclusive' allows clients to ask 1725for exclusive access. As suggested by the rfb spec this is 1726implemented by dropping other connections. Connecting multiple 1727clients in parallel requires all clients asking for a shared session 1728(vncviewer: -shared switch). This is the default. 'force-shared' 1729disables exclusive client access. Useful for shared desktop sessions, 1730where you don't want someone forgetting specify -shared disconnect 1731everybody else. 'ignore' completely ignores the shared flag and 1732allows everybody connect unconditionally. Doesn't conform to the rfb 1733spec but is traditional QEMU behavior. 1734 1735@item key-delay-ms 1736 1737Set keyboard delay, for key down and key up events, in milliseconds. 1738Default is 10. Keyboards are low-bandwidth devices, so this slowdown 1739can help the device and guest to keep up and not lose events in case 1740events are arriving in bulk. Possible causes for the latter are flaky 1741network connections, or scripts for automated testing. 1742 1743@end table 1744ETEXI 1745 1746STEXI 1747@end table 1748ETEXI 1749ARCHHEADING(, QEMU_ARCH_I386) 1750 1751ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1752STEXI 1753@table @option 1754ETEXI 1755 1756DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1757 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1758 QEMU_ARCH_I386) 1759STEXI 1760@item -win2k-hack 1761@findex -win2k-hack 1762Use it when installing Windows 2000 to avoid a disk full bug. After 1763Windows 2000 is installed, you no longer need this option (this option 1764slows down the IDE transfers). 1765ETEXI 1766 1767HXCOMM Deprecated by -rtc 1768DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1769 1770DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1771 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1772 QEMU_ARCH_I386) 1773STEXI 1774@item -no-fd-bootchk 1775@findex -no-fd-bootchk 1776Disable boot signature checking for floppy disks in BIOS. May 1777be needed to boot from old floppy disks. 1778ETEXI 1779 1780DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1781 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1782STEXI 1783@item -no-acpi 1784@findex -no-acpi 1785Disable ACPI (Advanced Configuration and Power Interface) support. Use 1786it if your guest OS complains about ACPI problems (PC target machine 1787only). 1788ETEXI 1789 1790DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1791 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1792STEXI 1793@item -no-hpet 1794@findex -no-hpet 1795Disable HPET support. 1796ETEXI 1797 1798DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1799 "-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" 1800 " ACPI table description\n", QEMU_ARCH_I386) 1801STEXI 1802@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}]...] 1803@findex -acpitable 1804Add ACPI table with specified header fields and context from specified files. 1805For file=, take whole ACPI table from the specified files, including all 1806ACPI headers (possible overridden by other options). 1807For data=, only data 1808portion of the table is used, all header information is specified in the 1809command line. 1810If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 1811fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 1812to ensure the field matches required by the Microsoft SLIC spec and the ACPI 1813spec. 1814ETEXI 1815 1816DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1817 "-smbios file=binary\n" 1818 " load SMBIOS entry from binary file\n" 1819 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1820 " [,uefi=on|off]\n" 1821 " specify SMBIOS type 0 fields\n" 1822 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1823 " [,uuid=uuid][,sku=str][,family=str]\n" 1824 " specify SMBIOS type 1 fields\n" 1825 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1826 " [,asset=str][,location=str]\n" 1827 " specify SMBIOS type 2 fields\n" 1828 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1829 " [,sku=str]\n" 1830 " specify SMBIOS type 3 fields\n" 1831 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1832 " [,asset=str][,part=str]\n" 1833 " specify SMBIOS type 4 fields\n" 1834 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1835 " [,asset=str][,part=str][,speed=%d]\n" 1836 " specify SMBIOS type 17 fields\n", 1837 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1838STEXI 1839@item -smbios file=@var{binary} 1840@findex -smbios 1841Load SMBIOS entry from binary file. 1842 1843@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1844Specify SMBIOS type 0 fields 1845 1846@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}] 1847Specify SMBIOS type 1 fields 1848 1849@item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}][,family=@var{str}] 1850Specify SMBIOS type 2 fields 1851 1852@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1853Specify SMBIOS type 3 fields 1854 1855@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1856Specify SMBIOS type 4 fields 1857 1858@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}] 1859Specify SMBIOS type 17 fields 1860ETEXI 1861 1862STEXI 1863@end table 1864ETEXI 1865DEFHEADING() 1866 1867DEFHEADING(Network options:) 1868STEXI 1869@table @option 1870ETEXI 1871 1872HXCOMM Legacy slirp options (now moved to -net user): 1873#ifdef CONFIG_SLIRP 1874DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1875DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1876DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1877#ifndef _WIN32 1878DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1879#endif 1880#endif 1881 1882DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1883#ifdef CONFIG_SLIRP 1884 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 1885 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 1886 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 1887 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n" 1888 " [,tftp=dir][,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1889#ifndef _WIN32 1890 "[,smb=dir[,smbserver=addr]]\n" 1891#endif 1892 " configure a user mode network backend with ID 'str',\n" 1893 " its DHCP server and optional services\n" 1894#endif 1895#ifdef _WIN32 1896 "-netdev tap,id=str,ifname=name\n" 1897 " configure a host TAP network backend with ID 'str'\n" 1898#else 1899 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1900 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1901 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1902 " [,poll-us=n]\n" 1903 " configure a host TAP network backend with ID 'str'\n" 1904 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1905 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1906 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1907 " to deconfigure it\n" 1908 " use '[down]script=no' to disable script execution\n" 1909 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1910 " configure it\n" 1911 " use 'fd=h' to connect to an already opened TAP interface\n" 1912 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1913 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1914 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1915 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1916 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1917 " use vhost=on to enable experimental in kernel accelerator\n" 1918 " (only has effect for virtio guests which use MSIX)\n" 1919 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1920 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1921 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1922 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1923 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 1924 " spent on busy polling for vhost net\n" 1925 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1926 " configure a host TAP network backend with ID 'str' that is\n" 1927 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1928 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1929#endif 1930#ifdef __linux__ 1931 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1932 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1933 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1934 " [,rxcookie=rxcookie][,offset=offset]\n" 1935 " configure a network backend with ID 'str' connected to\n" 1936 " an Ethernet over L2TPv3 pseudowire.\n" 1937 " Linux kernel 3.3+ as well as most routers can talk\n" 1938 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1939 " VM to a router and even VM to Host. It is a nearly-universal\n" 1940 " standard (RFC3391). Note - this implementation uses static\n" 1941 " pre-configured tunnels (same as the Linux kernel).\n" 1942 " use 'src=' to specify source address\n" 1943 " use 'dst=' to specify destination address\n" 1944 " use 'udp=on' to specify udp encapsulation\n" 1945 " use 'srcport=' to specify source udp port\n" 1946 " use 'dstport=' to specify destination udp port\n" 1947 " use 'ipv6=on' to force v6\n" 1948 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1949 " well as a weak security measure\n" 1950 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1951 " use 'txcookie=0x012345678' to specify a txcookie\n" 1952 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1953 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1954 " use 'pincounter=on' to work around broken counter handling in peer\n" 1955 " use 'offset=X' to add an extra offset between header and data\n" 1956#endif 1957 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1958 " configure a network backend to connect to another network\n" 1959 " using a socket connection\n" 1960 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1961 " configure a network backend to connect to a multicast maddr and port\n" 1962 " use 'localaddr=addr' to specify the host address to send packets from\n" 1963 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1964 " configure a network backend to connect to another network\n" 1965 " using an UDP tunnel\n" 1966#ifdef CONFIG_VDE 1967 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1968 " configure a network backend to connect to port 'n' of a vde switch\n" 1969 " running on host and listening for incoming connections on 'socketpath'.\n" 1970 " Use group 'groupname' and mode 'octalmode' to change default\n" 1971 " ownership and permissions for communication port.\n" 1972#endif 1973#ifdef CONFIG_NETMAP 1974 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 1975 " attach to the existing netmap-enabled network interface 'name', or to a\n" 1976 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 1977 " netmap device, defaults to '/dev/netmap')\n" 1978#endif 1979#ifdef CONFIG_POSIX 1980 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 1981 " configure a vhost-user network, backed by a chardev 'dev'\n" 1982#endif 1983 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n" 1984 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL) 1985DEF("nic", HAS_ARG, QEMU_OPTION_nic, 1986 "-nic [tap|bridge|" 1987#ifdef CONFIG_SLIRP 1988 "user|" 1989#endif 1990#ifdef __linux__ 1991 "l2tpv3|" 1992#endif 1993#ifdef CONFIG_VDE 1994 "vde|" 1995#endif 1996#ifdef CONFIG_NETMAP 1997 "netmap|" 1998#endif 1999#ifdef CONFIG_POSIX 2000 "vhost-user|" 2001#endif 2002 "socket][,option][,...][mac=macaddr]\n" 2003 " initialize an on-board / default host NIC (using MAC address\n" 2004 " macaddr) and connect it to the given host network backend\n" 2005 "-nic none use it alone to have zero network devices (the default is to\n" 2006 " provided a 'user' network connection)\n", 2007 QEMU_ARCH_ALL) 2008DEF("net", HAS_ARG, QEMU_OPTION_net, 2009 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 2010 " configure or create an on-board (or machine default) NIC and\n" 2011 " connect it to hub 0 (please use -nic unless you need a hub)\n" 2012 "-net [" 2013#ifdef CONFIG_SLIRP 2014 "user|" 2015#endif 2016 "tap|" 2017 "bridge|" 2018#ifdef CONFIG_VDE 2019 "vde|" 2020#endif 2021#ifdef CONFIG_NETMAP 2022 "netmap|" 2023#endif 2024 "socket][,option][,option][,...]\n" 2025 " old way to initialize a host network interface\n" 2026 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2027STEXI 2028@item -nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn] 2029@findex -nic 2030This option is a shortcut for configuring both the on-board (default) guest 2031NIC hardware and the host network backend in one go. The host backend options 2032are the same as with the corresponding @option{-netdev} options below. 2033The guest NIC model can be set with @option{model=@var{modelname}}. 2034Use @option{model=help} to list the available device types. 2035The hardware MAC address can be set with @option{mac=@var{macaddr}}. 2036 2037The following two example do exactly the same, to show how @option{-nic} can 2038be used to shorten the command line length (note that the e1000 is the default 2039on i386, so the @option{model=e1000} parameter could even be omitted here, too): 2040@example 2041qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32 2042qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 2043@end example 2044 2045@item -nic none 2046Indicate that no network devices should be configured. It is used to override 2047the default configuration (default NIC with ``user'' host network backend) 2048which is activated if no other networking options are provided. 2049 2050@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2051@findex -netdev 2052Configure user mode host network backend which requires no administrator 2053privilege to run. Valid options are: 2054 2055@table @option 2056@item id=@var{id} 2057Assign symbolic name for use in monitor commands. 2058 2059@item ipv4=on|off and ipv6=on|off 2060Specify that either IPv4 or IPv6 must be enabled. If neither is specified 2061both protocols are enabled. 2062 2063@item net=@var{addr}[/@var{mask}] 2064Set IP network address the guest will see. Optionally specify the netmask, 2065either in the form a.b.c.d or as number of valid top-most bits. Default is 206610.0.2.0/24. 2067 2068@item host=@var{addr} 2069Specify the guest-visible address of the host. Default is the 2nd IP in the 2070guest network, i.e. x.x.x.2. 2071 2072@item ipv6-net=@var{addr}[/@var{int}] 2073Set IPv6 network address the guest will see (default is fec0::/64). The 2074network prefix is given in the usual hexadecimal IPv6 address 2075notation. The prefix size is optional, and is given as the number of 2076valid top-most bits (default is 64). 2077 2078@item ipv6-host=@var{addr} 2079Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2080the guest network, i.e. xxxx::2. 2081 2082@item restrict=on|off 2083If this option is enabled, the guest will be isolated, i.e. it will not be 2084able to contact the host and no guest IP packets will be routed over the host 2085to the outside. This option does not affect any explicitly set forwarding rules. 2086 2087@item hostname=@var{name} 2088Specifies the client hostname reported by the built-in DHCP server. 2089 2090@item dhcpstart=@var{addr} 2091Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2092is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2093 2094@item dns=@var{addr} 2095Specify the guest-visible address of the virtual nameserver. The address must 2096be different from the host address. Default is the 3rd IP in the guest network, 2097i.e. x.x.x.3. 2098 2099@item ipv6-dns=@var{addr} 2100Specify the guest-visible address of the IPv6 virtual nameserver. The address 2101must be different from the host address. Default is the 3rd IP in the guest 2102network, i.e. xxxx::3. 2103 2104@item dnssearch=@var{domain} 2105Provides an entry for the domain-search list sent by the built-in 2106DHCP server. More than one domain suffix can be transmitted by specifying 2107this option multiple times. If supported, this will cause the guest to 2108automatically try to append the given domain suffix(es) in case a domain name 2109can not be resolved. 2110 2111Example: 2112@example 2113qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org 2114@end example 2115 2116@item domainname=@var{domain} 2117Specifies the client domain name reported by the built-in DHCP server. 2118 2119@item tftp=@var{dir} 2120When using the user mode network stack, activate a built-in TFTP 2121server. The files in @var{dir} will be exposed as the root of a TFTP server. 2122The TFTP client on the guest must be configured in binary mode (use the command 2123@code{bin} of the Unix TFTP client). 2124 2125@item bootfile=@var{file} 2126When using the user mode network stack, broadcast @var{file} as the BOOTP 2127filename. In conjunction with @option{tftp}, this can be used to network boot 2128a guest from a local directory. 2129 2130Example (using pxelinux): 2131@example 2132qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \ 2133 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2134@end example 2135 2136@item smb=@var{dir}[,smbserver=@var{addr}] 2137When using the user mode network stack, activate a built-in SMB 2138server so that Windows OSes can access to the host files in @file{@var{dir}} 2139transparently. The IP address of the SMB server can be set to @var{addr}. By 2140default the 4th IP in the guest network is used, i.e. x.x.x.4. 2141 2142In the guest Windows OS, the line: 2143@example 214410.0.2.4 smbserver 2145@end example 2146must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2147or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2148 2149Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2150 2151Note that a SAMBA server must be installed on the host OS. 2152 2153@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2154Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2155the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2156@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2157given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2158be bound to a specific host interface. If no connection type is set, TCP is 2159used. This option can be given multiple times. 2160 2161For example, to redirect host X11 connection from screen 1 to guest 2162screen 0, use the following: 2163 2164@example 2165# on the host 2166qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000 2167# this host xterm should open in the guest X11 server 2168xterm -display :1 2169@end example 2170 2171To redirect telnet connections from host port 5555 to telnet port on 2172the guest, use the following: 2173 2174@example 2175# on the host 2176qemu-system-i386 -nic user,hostfwd=tcp::5555-:23 2177telnet localhost 5555 2178@end example 2179 2180Then when you use on the host @code{telnet localhost 5555}, you 2181connect to the guest telnet server. 2182 2183@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2184@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2185Forward guest TCP connections to the IP address @var{server} on port @var{port} 2186to the character device @var{dev} or to a program executed by @var{cmd:command} 2187which gets spawned for each connection. This option can be given multiple times. 2188 2189You can either use a chardev directly and have that one used throughout QEMU's 2190lifetime, like in the following example: 2191 2192@example 2193# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2194# the guest accesses it 2195qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 2196@end example 2197 2198Or you can execute a command on every TCP connection established by the guest, 2199so that QEMU behaves similar to an inetd process for that virtual server: 2200 2201@example 2202# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2203# and connect the TCP stream to its stdin/stdout 2204qemu-system-i386 -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2205@end example 2206 2207@end table 2208 2209Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 2210processed and applied to -net user. Mixing them with the new configuration 2211syntax gives undefined results. Their use for new applications is discouraged 2212as they will be removed from future versions. 2213 2214@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2215Configure a host TAP network backend with ID @var{id}. 2216 2217Use the network script @var{file} to configure it and the network script 2218@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2219automatically provides one. The default network configure script is 2220@file{/etc/qemu-ifup} and the default network deconfigure script is 2221@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2222to disable script execution. 2223 2224If running QEMU as an unprivileged user, use the network helper 2225@var{helper} to configure the TAP interface and attach it to the bridge. 2226The default network helper executable is @file{/path/to/qemu-bridge-helper} 2227and the default bridge device is @file{br0}. 2228 2229@option{fd}=@var{h} can be used to specify the handle of an already 2230opened host TAP interface. 2231 2232Examples: 2233 2234@example 2235#launch a QEMU instance with the default network script 2236qemu-system-i386 linux.img -nic tap 2237@end example 2238 2239@example 2240#launch a QEMU instance with two NICs, each one connected 2241#to a TAP device 2242qemu-system-i386 linux.img \ 2243 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \ 2244 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1 2245@end example 2246 2247@example 2248#launch a QEMU instance with the default network helper to 2249#connect a TAP device to bridge br0 2250qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \ 2251 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper" 2252@end example 2253 2254@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2255Connect a host TAP network interface to a host bridge device. 2256 2257Use the network helper @var{helper} to configure the TAP interface and 2258attach it to the bridge. The default network helper executable is 2259@file{/path/to/qemu-bridge-helper} and the default bridge 2260device is @file{br0}. 2261 2262Examples: 2263 2264@example 2265#launch a QEMU instance with the default network helper to 2266#connect a TAP device to bridge br0 2267qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1 2268@end example 2269 2270@example 2271#launch a QEMU instance with the default network helper to 2272#connect a TAP device to bridge qemubr0 2273qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1 2274@end example 2275 2276@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2277 2278This host network backend can be used to connect the guest's network to 2279another QEMU virtual machine using a TCP socket connection. If @option{listen} 2280is specified, QEMU waits for incoming connections on @var{port} 2281(@var{host} is optional). @option{connect} is used to connect to 2282another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2283specifies an already opened TCP socket. 2284 2285Example: 2286@example 2287# launch a first QEMU instance 2288qemu-system-i386 linux.img \ 2289 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2290 -netdev socket,id=n1,listen=:1234 2291# connect the network of this instance to the network of the first instance 2292qemu-system-i386 linux.img \ 2293 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2294 -netdev socket,id=n2,connect=127.0.0.1:1234 2295@end example 2296 2297@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2298 2299Configure a socket host network backend to share the guest's network traffic 2300with another QEMU virtual machines using a UDP multicast socket, effectively 2301making a bus for every QEMU with same multicast address @var{maddr} and @var{port}. 2302NOTES: 2303@enumerate 2304@item 2305Several QEMU can be running on different hosts and share same bus (assuming 2306correct multicast setup for these hosts). 2307@item 2308mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2309@url{http://user-mode-linux.sf.net}. 2310@item 2311Use @option{fd=h} to specify an already opened UDP multicast socket. 2312@end enumerate 2313 2314Example: 2315@example 2316# launch one QEMU instance 2317qemu-system-i386 linux.img \ 2318 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2319 -netdev socket,id=n1,mcast=230.0.0.1:1234 2320# launch another QEMU instance on same "bus" 2321qemu-system-i386 linux.img \ 2322 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \ 2323 -netdev socket,id=n2,mcast=230.0.0.1:1234 2324# launch yet another QEMU instance on same "bus" 2325qemu-system-i386 linux.img \ 2326 -device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \ 2327 -netdev socket,id=n3,mcast=230.0.0.1:1234 2328@end example 2329 2330Example (User Mode Linux compat.): 2331@example 2332# launch QEMU instance (note mcast address selected is UML's default) 2333qemu-system-i386 linux.img \ 2334 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2335 -netdev socket,id=n1,mcast=239.192.168.1:1102 2336# launch UML 2337/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2338@end example 2339 2340Example (send packets from host's 1.2.3.4): 2341@example 2342qemu-system-i386 linux.img \ 2343 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \ 2344 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2345@end example 2346 2347@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}] 2348Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a 2349popular protocol to transport Ethernet (and other Layer 2) data frames between 2350two systems. It is present in routers, firewalls and the Linux kernel 2351(from version 3.3 onwards). 2352 2353This transport allows a VM to communicate to another VM, router or firewall directly. 2354 2355@table @option 2356@item src=@var{srcaddr} 2357 source address (mandatory) 2358@item dst=@var{dstaddr} 2359 destination address (mandatory) 2360@item udp 2361 select udp encapsulation (default is ip). 2362@item srcport=@var{srcport} 2363 source udp port. 2364@item dstport=@var{dstport} 2365 destination udp port. 2366@item ipv6 2367 force v6, otherwise defaults to v4. 2368@item rxcookie=@var{rxcookie} 2369@itemx txcookie=@var{txcookie} 2370 Cookies are a weak form of security in the l2tpv3 specification. 2371Their function is mostly to prevent misconfiguration. By default they are 32 2372bit. 2373@item cookie64 2374 Set cookie size to 64 bit instead of the default 32 2375@item counter=off 2376 Force a 'cut-down' L2TPv3 with no counter as in 2377draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2378@item pincounter=on 2379 Work around broken counter handling in peer. This may also help on 2380networks which have packet reorder. 2381@item offset=@var{offset} 2382 Add an extra offset between header and data 2383@end table 2384 2385For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2386on the remote Linux host 1.2.3.4: 2387@example 2388# Setup tunnel on linux host using raw ip as encapsulation 2389# on 1.2.3.4 2390ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2391 encap udp udp_sport 16384 udp_dport 16384 2392ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2393 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2394ifconfig vmtunnel0 mtu 1500 2395ifconfig vmtunnel0 up 2396brctl addif br-lan vmtunnel0 2397 2398 2399# on 4.3.2.1 2400# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2401 2402qemu-system-i386 linux.img -device e1000,netdev=n1 \ 2403 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2404 2405@end example 2406 2407@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2408Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and 2409listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2410and MODE @var{octalmode} to change default ownership and permissions for 2411communication port. This option is only available if QEMU has been compiled 2412with vde support enabled. 2413 2414Example: 2415@example 2416# launch vde switch 2417vde_switch -F -sock /tmp/myswitch 2418# launch QEMU instance 2419qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch 2420@end example 2421 2422@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2423 2424Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2425be a unix domain socket backed one. The vhost-user uses a specifically defined 2426protocol to pass vhost ioctl replacement messages to an application on the other 2427end of the socket. On non-MSIX guests, the feature can be forced with 2428@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2429be created for multiqueue vhost-user. 2430 2431Example: 2432@example 2433qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2434 -numa node,memdev=mem \ 2435 -chardev socket,id=chr0,path=/path/to/socket \ 2436 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2437 -device virtio-net-pci,netdev=net0 2438@end example 2439 2440@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}] 2441 2442Create a hub port on the emulated hub with ID @var{hubid}. 2443 2444The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a 2445single netdev. Alternatively, you can also connect the hubport to another 2446netdev with ID @var{nd} by using the @option{netdev=@var{nd}} option. 2447 2448@item -net nic[,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2449@findex -net 2450Legacy option to configure or create an on-board (or machine default) Network 2451Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. 2452the default hub), or to the netdev @var{nd}. 2453The NIC is an e1000 by default on the PC target. Optionally, the MAC address 2454can be changed to @var{mac}, the device address set to @var{addr} (PCI cards 2455only), and a @var{name} can be assigned for use in monitor commands. 2456Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2457that the card should have; this option currently only affects virtio cards; set 2458@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2459NIC is created. QEMU can emulate several different models of network card. 2460Use @code{-net nic,model=help} for a list of available devices for your target. 2461 2462@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=@var{name}] 2463Configure a host network backend (with the options corresponding to the same 2464@option{-netdev} option) and connect it to the emulated hub 0 (the default 2465hub). Use @var{name} to specify the name of the hub port. 2466ETEXI 2467 2468STEXI 2469@end table 2470ETEXI 2471DEFHEADING() 2472 2473DEFHEADING(Character device options:) 2474 2475DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2476 "-chardev help\n" 2477 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2478 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2479 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n" 2480 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n" 2481 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n" 2482 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2483 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2484 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2485 " [,logfile=PATH][,logappend=on|off]\n" 2486 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2487 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2488 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2489 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2490 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2491 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2492#ifdef _WIN32 2493 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2494 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2495#else 2496 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2497 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2498#endif 2499#ifdef CONFIG_BRLAPI 2500 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2501#endif 2502#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2503 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2504 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2505 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2506#endif 2507#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2508 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2509 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2510#endif 2511#if defined(CONFIG_SPICE) 2512 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2513 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2514#endif 2515 , QEMU_ARCH_ALL 2516) 2517 2518STEXI 2519 2520The general form of a character device option is: 2521@table @option 2522@item -chardev @var{backend},id=@var{id}[,mux=on|off][,@var{options}] 2523@findex -chardev 2524Backend is one of: 2525@option{null}, 2526@option{socket}, 2527@option{udp}, 2528@option{msmouse}, 2529@option{vc}, 2530@option{ringbuf}, 2531@option{file}, 2532@option{pipe}, 2533@option{console}, 2534@option{serial}, 2535@option{pty}, 2536@option{stdio}, 2537@option{braille}, 2538@option{tty}, 2539@option{parallel}, 2540@option{parport}, 2541@option{spicevmc}, 2542@option{spiceport}. 2543The specific backend will determine the applicable options. 2544 2545Use @code{-chardev help} to print all available chardev backend types. 2546 2547All devices must have an id, which can be any string up to 127 characters long. 2548It is used to uniquely identify this device in other command line directives. 2549 2550A character device may be used in multiplexing mode by multiple front-ends. 2551Specify @option{mux=on} to enable this mode. 2552A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2553backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2554If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2555create a multiplexer with your specified ID, and you can then configure multiple 2556front ends to use that chardev ID for their input/output. Up to four different 2557front ends can be connected to a single multiplexed chardev. (Without 2558multiplexing enabled, a chardev can only be used by a single front end.) 2559For instance you could use this to allow a single stdio chardev to be used by 2560two serial ports and the QEMU monitor: 2561 2562@example 2563-chardev stdio,mux=on,id=char0 \ 2564-mon chardev=char0,mode=readline \ 2565-serial chardev:char0 \ 2566-serial chardev:char0 2567@end example 2568 2569You can have more than one multiplexer in a system configuration; for instance 2570you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2571multiplexed between the QEMU monitor and a parallel port: 2572 2573@example 2574-chardev stdio,mux=on,id=char0 \ 2575-mon chardev=char0,mode=readline \ 2576-parallel chardev:char0 \ 2577-chardev tcp,...,mux=on,id=char1 \ 2578-serial chardev:char1 \ 2579-serial chardev:char1 2580@end example 2581 2582When you're using a multiplexed character device, some escape sequences are 2583interpreted in the input. @xref{mux_keys, Keys in the character backend 2584multiplexer}. 2585 2586Note that some other command line options may implicitly create multiplexed 2587character backends; for instance @option{-serial mon:stdio} creates a 2588multiplexed stdio backend connected to the serial port and the QEMU monitor, 2589and @option{-nographic} also multiplexes the console and the monitor to 2590stdio. 2591 2592There is currently no support for multiplexing in the other direction 2593(where a single QEMU front end takes input and output from multiple chardevs). 2594 2595Every backend supports the @option{logfile} option, which supplies the path 2596to a file to record all data transmitted via the backend. The @option{logappend} 2597option controls whether the log file will be truncated or appended to when 2598opened. 2599 2600@end table 2601 2602The available backends are: 2603 2604@table @option 2605@item -chardev null,id=@var{id} 2606A void device. This device will not emit any data, and will drop any data it 2607receives. The null backend does not take any options. 2608 2609@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix options}][,server][,nowait][,telnet][,reconnect=@var{seconds}][,tls-creds=@var{id}] 2610 2611Create a two-way stream socket, which can be either a TCP or a unix socket. A 2612unix socket will be created if @option{path} is specified. Behaviour is 2613undefined if TCP options are specified for a unix socket. 2614 2615@option{server} specifies that the socket shall be a listening socket. 2616 2617@option{nowait} specifies that QEMU should not block waiting for a client to 2618connect to a listening socket. 2619 2620@option{telnet} specifies that traffic on the socket should interpret telnet 2621escape sequences. 2622 2623@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2624the remote end goes away. qemu will delay this many seconds and then attempt 2625to reconnect. Zero disables reconnecting, and is the default. 2626 2627@option{tls-creds} requests enablement of the TLS protocol for encryption, 2628and specifies the id of the TLS credentials to use for the handshake. The 2629credentials must be previously created with the @option{-object tls-creds} 2630argument. 2631 2632TCP and unix socket options are given below: 2633 2634@table @option 2635 2636@item TCP options: port=@var{port}[,host=@var{host}][,to=@var{to}][,ipv4][,ipv6][,nodelay] 2637 2638@option{host} for a listening socket specifies the local address to be bound. 2639For a connecting socket species the remote host to connect to. @option{host} is 2640optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2641 2642@option{port} for a listening socket specifies the local port to be bound. For a 2643connecting socket specifies the port on the remote host to connect to. 2644@option{port} can be given as either a port number or a service name. 2645@option{port} is required. 2646 2647@option{to} is only relevant to listening sockets. If it is specified, and 2648@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2649to and including @option{to} until it succeeds. @option{to} must be specified 2650as a port number. 2651 2652@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2653If neither is specified the socket may use either protocol. 2654 2655@option{nodelay} disables the Nagle algorithm. 2656 2657@item unix options: path=@var{path} 2658 2659@option{path} specifies the local path of the unix socket. @option{path} is 2660required. 2661 2662@end table 2663 2664@item -chardev udp,id=@var{id}[,host=@var{host}],port=@var{port}[,localaddr=@var{localaddr}][,localport=@var{localport}][,ipv4][,ipv6] 2665 2666Sends all traffic from the guest to a remote host over UDP. 2667 2668@option{host} specifies the remote host to connect to. If not specified it 2669defaults to @code{localhost}. 2670 2671@option{port} specifies the port on the remote host to connect to. @option{port} 2672is required. 2673 2674@option{localaddr} specifies the local address to bind to. If not specified it 2675defaults to @code{0.0.0.0}. 2676 2677@option{localport} specifies the local port to bind to. If not specified any 2678available local port will be used. 2679 2680@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2681If neither is specified the device may use either protocol. 2682 2683@item -chardev msmouse,id=@var{id} 2684 2685Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2686take any options. 2687 2688@item -chardev vc,id=@var{id}[[,width=@var{width}][,height=@var{height}]][[,cols=@var{cols}][,rows=@var{rows}]] 2689 2690Connect to a QEMU text console. @option{vc} may optionally be given a specific 2691size. 2692 2693@option{width} and @option{height} specify the width and height respectively of 2694the console, in pixels. 2695 2696@option{cols} and @option{rows} specify that the console be sized to fit a text 2697console with the given dimensions. 2698 2699@item -chardev ringbuf,id=@var{id}[,size=@var{size}] 2700 2701Create a ring buffer with fixed size @option{size}. 2702@var{size} must be a power of two and defaults to @code{64K}. 2703 2704@item -chardev file,id=@var{id},path=@var{path} 2705 2706Log all traffic received from the guest to a file. 2707 2708@option{path} specifies the path of the file to be opened. This file will be 2709created if it does not already exist, and overwritten if it does. @option{path} 2710is required. 2711 2712@item -chardev pipe,id=@var{id},path=@var{path} 2713 2714Create a two-way connection to the guest. The behaviour differs slightly between 2715Windows hosts and other hosts: 2716 2717On Windows, a single duplex pipe will be created at 2718@file{\\.pipe\@option{path}}. 2719 2720On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2721@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2722received by the guest. Data written by the guest can be read from 2723@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2724be present. 2725 2726@option{path} forms part of the pipe path as described above. @option{path} is 2727required. 2728 2729@item -chardev console,id=@var{id} 2730 2731Send traffic from the guest to QEMU's standard output. @option{console} does not 2732take any options. 2733 2734@option{console} is only available on Windows hosts. 2735 2736@item -chardev serial,id=@var{id},path=@option{path} 2737 2738Send traffic from the guest to a serial device on the host. 2739 2740On Unix hosts serial will actually accept any tty device, 2741not only serial lines. 2742 2743@option{path} specifies the name of the serial device to open. 2744 2745@item -chardev pty,id=@var{id} 2746 2747Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2748not take any options. 2749 2750@option{pty} is not available on Windows hosts. 2751 2752@item -chardev stdio,id=@var{id}[,signal=on|off] 2753Connect to standard input and standard output of the QEMU process. 2754 2755@option{signal} controls if signals are enabled on the terminal, that includes 2756exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2757default, use @option{signal=off} to disable it. 2758 2759@item -chardev braille,id=@var{id} 2760 2761Connect to a local BrlAPI server. @option{braille} does not take any options. 2762 2763@item -chardev tty,id=@var{id},path=@var{path} 2764 2765@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2766DragonFlyBSD hosts. It is an alias for @option{serial}. 2767 2768@option{path} specifies the path to the tty. @option{path} is required. 2769 2770@item -chardev parallel,id=@var{id},path=@var{path} 2771@itemx -chardev parport,id=@var{id},path=@var{path} 2772 2773@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2774 2775Connect to a local parallel port. 2776 2777@option{path} specifies the path to the parallel port device. @option{path} is 2778required. 2779 2780@item -chardev spicevmc,id=@var{id},debug=@var{debug},name=@var{name} 2781 2782@option{spicevmc} is only available when spice support is built in. 2783 2784@option{debug} debug level for spicevmc 2785 2786@option{name} name of spice channel to connect to 2787 2788Connect to a spice virtual machine channel, such as vdiport. 2789 2790@item -chardev spiceport,id=@var{id},debug=@var{debug},name=@var{name} 2791 2792@option{spiceport} is only available when spice support is built in. 2793 2794@option{debug} debug level for spicevmc 2795 2796@option{name} name of spice port to connect to 2797 2798Connect to a spice port, allowing a Spice client to handle the traffic 2799identified by a name (preferably a fqdn). 2800ETEXI 2801 2802STEXI 2803@end table 2804ETEXI 2805DEFHEADING() 2806 2807DEFHEADING(Bluetooth(R) options:) 2808STEXI 2809@table @option 2810ETEXI 2811 2812DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 2813 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 2814 "-bt hci,host[:id]\n" \ 2815 " use host's HCI with the given name\n" \ 2816 "-bt hci[,vlan=n]\n" \ 2817 " emulate a standard HCI in virtual scatternet 'n'\n" \ 2818 "-bt vhci[,vlan=n]\n" \ 2819 " add host computer to virtual scatternet 'n' using VHCI\n" \ 2820 "-bt device:dev[,vlan=n]\n" \ 2821 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 2822 QEMU_ARCH_ALL) 2823STEXI 2824@item -bt hci[...] 2825@findex -bt 2826Defines the function of the corresponding Bluetooth HCI. -bt options 2827are matched with the HCIs present in the chosen machine type. For 2828example when emulating a machine with only one HCI built into it, only 2829the first @code{-bt hci[...]} option is valid and defines the HCI's 2830logic. The Transport Layer is decided by the machine type. Currently 2831the machines @code{n800} and @code{n810} have one HCI and all other 2832machines have none. 2833 2834@anchor{bt-hcis} 2835The following three types are recognized: 2836 2837@table @option 2838@item -bt hci,null 2839(default) The corresponding Bluetooth HCI assumes no internal logic 2840and will not respond to any HCI commands or emit events. 2841 2842@item -bt hci,host[:@var{id}] 2843(@code{bluez} only) The corresponding HCI passes commands / events 2844to / from the physical HCI identified by the name @var{id} (default: 2845@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 2846capable systems like Linux. 2847 2848@item -bt hci[,vlan=@var{n}] 2849Add a virtual, standard HCI that will participate in the Bluetooth 2850scatternet @var{n} (default @code{0}). Similarly to @option{-net} 2851VLANs, devices inside a bluetooth network @var{n} can only communicate 2852with other devices in the same network (scatternet). 2853@end table 2854 2855@item -bt vhci[,vlan=@var{n}] 2856(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 2857to the host bluetooth stack instead of to the emulated target. This 2858allows the host and target machines to participate in a common scatternet 2859and communicate. Requires the Linux @code{vhci} driver installed. Can 2860be used as following: 2861 2862@example 2863qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 2864@end example 2865 2866@item -bt device:@var{dev}[,vlan=@var{n}] 2867Emulate a bluetooth device @var{dev} and place it in network @var{n} 2868(default @code{0}). QEMU can only emulate one type of bluetooth devices 2869currently: 2870 2871@table @option 2872@item keyboard 2873Virtual wireless keyboard implementing the HIDP bluetooth profile. 2874@end table 2875ETEXI 2876 2877STEXI 2878@end table 2879ETEXI 2880DEFHEADING() 2881 2882#ifdef CONFIG_TPM 2883DEFHEADING(TPM device options:) 2884 2885DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 2886 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 2887 " use path to provide path to a character device; default is /dev/tpm0\n" 2888 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 2889 " not provided it will be searched for in /sys/class/misc/tpm?/device\n" 2890 "-tpmdev emulator,id=id,chardev=dev\n" 2891 " configure the TPM device using chardev backend\n", 2892 QEMU_ARCH_ALL) 2893STEXI 2894 2895The general form of a TPM device option is: 2896@table @option 2897 2898@item -tpmdev @var{backend},id=@var{id}[,@var{options}] 2899@findex -tpmdev 2900 2901The specific backend type will determine the applicable options. 2902The @code{-tpmdev} option creates the TPM backend and requires a 2903@code{-device} option that specifies the TPM frontend interface model. 2904 2905Use @code{-tpmdev help} to print all available TPM backend types. 2906 2907@end table 2908 2909The available backends are: 2910 2911@table @option 2912 2913@item -tpmdev passthrough,id=@var{id},path=@var{path},cancel-path=@var{cancel-path} 2914 2915(Linux-host only) Enable access to the host's TPM using the passthrough 2916driver. 2917 2918@option{path} specifies the path to the host's TPM device, i.e., on 2919a Linux host this would be @code{/dev/tpm0}. 2920@option{path} is optional and by default @code{/dev/tpm0} is used. 2921 2922@option{cancel-path} specifies the path to the host TPM device's sysfs 2923entry allowing for cancellation of an ongoing TPM command. 2924@option{cancel-path} is optional and by default QEMU will search for the 2925sysfs entry to use. 2926 2927Some notes about using the host's TPM with the passthrough driver: 2928 2929The TPM device accessed by the passthrough driver must not be 2930used by any other application on the host. 2931 2932Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 2933the VM's firmware (BIOS/UEFI) will not be able to initialize the 2934TPM again and may therefore not show a TPM-specific menu that would 2935otherwise allow the user to configure the TPM, e.g., allow the user to 2936enable/disable or activate/deactivate the TPM. 2937Further, if TPM ownership is released from within a VM then the host's TPM 2938will get disabled and deactivated. To enable and activate the 2939TPM again afterwards, the host has to be rebooted and the user is 2940required to enter the firmware's menu to enable and activate the TPM. 2941If the TPM is left disabled and/or deactivated most TPM commands will fail. 2942 2943To create a passthrough TPM use the following two options: 2944@example 2945-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 2946@end example 2947Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 2948@code{tpmdev=tpm0} in the device option. 2949 2950@item -tpmdev emulator,id=@var{id},chardev=@var{dev} 2951 2952(Linux-host only) Enable access to a TPM emulator using Unix domain socket based 2953chardev backend. 2954 2955@option{chardev} specifies the unique ID of a character device backend that provides connection to the software TPM server. 2956 2957To create a TPM emulator backend device with chardev socket backend: 2958@example 2959 2960-chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0 2961 2962@end example 2963 2964ETEXI 2965 2966STEXI 2967@end table 2968ETEXI 2969DEFHEADING() 2970 2971#endif 2972 2973DEFHEADING(Linux/Multiboot boot specific:) 2974STEXI 2975 2976When using these options, you can use a given Linux or Multiboot 2977kernel without installing it in the disk image. It can be useful 2978for easier testing of various kernels. 2979 2980@table @option 2981ETEXI 2982 2983DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 2984 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 2985STEXI 2986@item -kernel @var{bzImage} 2987@findex -kernel 2988Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 2989or in multiboot format. 2990ETEXI 2991 2992DEF("append", HAS_ARG, QEMU_OPTION_append, \ 2993 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 2994STEXI 2995@item -append @var{cmdline} 2996@findex -append 2997Use @var{cmdline} as kernel command line 2998ETEXI 2999 3000DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3001 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3002STEXI 3003@item -initrd @var{file} 3004@findex -initrd 3005Use @var{file} as initial ram disk. 3006 3007@item -initrd "@var{file1} arg=foo,@var{file2}" 3008 3009This syntax is only available with multiboot. 3010 3011Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3012first module. 3013ETEXI 3014 3015DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3016 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3017STEXI 3018@item -dtb @var{file} 3019@findex -dtb 3020Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3021on boot. 3022ETEXI 3023 3024STEXI 3025@end table 3026ETEXI 3027DEFHEADING() 3028 3029DEFHEADING(Debug/Expert options:) 3030STEXI 3031@table @option 3032ETEXI 3033 3034DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3035 "-fw_cfg [name=]<name>,file=<file>\n" 3036 " add named fw_cfg entry with contents from file\n" 3037 "-fw_cfg [name=]<name>,string=<str>\n" 3038 " add named fw_cfg entry with contents from string\n", 3039 QEMU_ARCH_ALL) 3040STEXI 3041 3042@item -fw_cfg [name=]@var{name},file=@var{file} 3043@findex -fw_cfg 3044Add named fw_cfg entry with contents from file @var{file}. 3045 3046@item -fw_cfg [name=]@var{name},string=@var{str} 3047Add named fw_cfg entry with contents from string @var{str}. 3048 3049The terminating NUL character of the contents of @var{str} will not be 3050included as part of the fw_cfg item data. To insert contents with 3051embedded NUL characters, you have to use the @var{file} parameter. 3052 3053The fw_cfg entries are passed by QEMU through to the guest. 3054 3055Example: 3056@example 3057 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3058@end example 3059creates an fw_cfg entry named opt/com.mycompany/blob with contents 3060from ./my_blob.bin. 3061 3062ETEXI 3063 3064DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3065 "-serial dev redirect the serial port to char device 'dev'\n", 3066 QEMU_ARCH_ALL) 3067STEXI 3068@item -serial @var{dev} 3069@findex -serial 3070Redirect the virtual serial port to host character device 3071@var{dev}. The default device is @code{vc} in graphical mode and 3072@code{stdio} in non graphical mode. 3073 3074This option can be used several times to simulate up to 4 serial 3075ports. 3076 3077Use @code{-serial none} to disable all serial ports. 3078 3079Available character devices are: 3080@table @option 3081@item vc[:@var{W}x@var{H}] 3082Virtual console. Optionally, a width and height can be given in pixel with 3083@example 3084vc:800x600 3085@end example 3086It is also possible to specify width or height in characters: 3087@example 3088vc:80Cx24C 3089@end example 3090@item pty 3091[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3092@item none 3093No device is allocated. 3094@item null 3095void device 3096@item chardev:@var{id} 3097Use a named character device defined with the @code{-chardev} option. 3098@item /dev/XXX 3099[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3100parameters are set according to the emulated ones. 3101@item /dev/parport@var{N} 3102[Linux only, parallel port only] Use host parallel port 3103@var{N}. Currently SPP and EPP parallel port features can be used. 3104@item file:@var{filename} 3105Write output to @var{filename}. No character can be read. 3106@item stdio 3107[Unix only] standard input/output 3108@item pipe:@var{filename} 3109name pipe @var{filename} 3110@item COM@var{n} 3111[Windows only] Use host serial port @var{n} 3112@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3113This implements UDP Net Console. 3114When @var{remote_host} or @var{src_ip} are not specified 3115they default to @code{0.0.0.0}. 3116When not using a specified @var{src_port} a random port is automatically chosen. 3117 3118If you just want a simple readonly console you can use @code{netcat} or 3119@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3120@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3121will appear in the netconsole session. 3122 3123If you plan to send characters back via netconsole or you want to stop 3124and start QEMU a lot of times, you should have QEMU use the same 3125source port each time by using something like @code{-serial 3126udp::4555@@:4556} to QEMU. Another approach is to use a patched 3127version of netcat which can listen to a TCP port and send and receive 3128characters via udp. If you have a patched version of netcat which 3129activates telnet remote echo and single char transfer, then you can 3130use the following options to set up a netcat redirector to allow 3131telnet on port 5555 to access the QEMU port. 3132@table @code 3133@item QEMU Options: 3134-serial udp::4555@@:4556 3135@item netcat options: 3136-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3137@item telnet options: 3138localhost 5555 3139@end table 3140 3141@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3142The TCP Net Console has two modes of operation. It can send the serial 3143I/O to a location or wait for a connection from a location. By default 3144the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3145the @var{server} option QEMU will wait for a client socket application 3146to connect to the port before continuing, unless the @code{nowait} 3147option was specified. The @code{nodelay} option disables the Nagle buffering 3148algorithm. The @code{reconnect} option only applies if @var{noserver} is 3149set, if the connection goes down it will attempt to reconnect at the 3150given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3151one TCP connection at a time is accepted. You can use @code{telnet} to 3152connect to the corresponding character device. 3153@table @code 3154@item Example to send tcp console to 192.168.0.2 port 4444 3155-serial tcp:192.168.0.2:4444 3156@item Example to listen and wait on port 4444 for connection 3157-serial tcp::4444,server 3158@item Example to not wait and listen on ip 192.168.0.100 port 4444 3159-serial tcp:192.168.0.100:4444,server,nowait 3160@end table 3161 3162@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3163The telnet protocol is used instead of raw tcp sockets. The options 3164work the same as if you had specified @code{-serial tcp}. The 3165difference is that the port acts like a telnet server or client using 3166telnet option negotiation. This will also allow you to send the 3167MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3168sequence. Typically in unix telnet you do it with Control-] and then 3169type "send break" followed by pressing the enter key. 3170 3171@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3172A unix domain socket is used instead of a tcp socket. The option works the 3173same as if you had specified @code{-serial tcp} except the unix domain socket 3174@var{path} is used for connections. 3175 3176@item mon:@var{dev_string} 3177This is a special option to allow the monitor to be multiplexed onto 3178another serial port. The monitor is accessed with key sequence of 3179@key{Control-a} and then pressing @key{c}. 3180@var{dev_string} should be any one of the serial devices specified 3181above. An example to multiplex the monitor onto a telnet server 3182listening on port 4444 would be: 3183@table @code 3184@item -serial mon:telnet::4444,server,nowait 3185@end table 3186When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3187QEMU any more but will be passed to the guest instead. 3188 3189@item braille 3190Braille device. This will use BrlAPI to display the braille output on a real 3191or fake device. 3192 3193@item msmouse 3194Three button serial mouse. Configure the guest to use Microsoft protocol. 3195@end table 3196ETEXI 3197 3198DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3199 "-parallel dev redirect the parallel port to char device 'dev'\n", 3200 QEMU_ARCH_ALL) 3201STEXI 3202@item -parallel @var{dev} 3203@findex -parallel 3204Redirect the virtual parallel port to host device @var{dev} (same 3205devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3206be used to use hardware devices connected on the corresponding host 3207parallel port. 3208 3209This option can be used several times to simulate up to 3 parallel 3210ports. 3211 3212Use @code{-parallel none} to disable all parallel ports. 3213ETEXI 3214 3215DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3216 "-monitor dev redirect the monitor to char device 'dev'\n", 3217 QEMU_ARCH_ALL) 3218STEXI 3219@item -monitor @var{dev} 3220@findex -monitor 3221Redirect the monitor to host device @var{dev} (same devices as the 3222serial port). 3223The default device is @code{vc} in graphical mode and @code{stdio} in 3224non graphical mode. 3225Use @code{-monitor none} to disable the default monitor. 3226ETEXI 3227DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3228 "-qmp dev like -monitor but opens in 'control' mode\n", 3229 QEMU_ARCH_ALL) 3230STEXI 3231@item -qmp @var{dev} 3232@findex -qmp 3233Like -monitor but opens in 'control' mode. 3234ETEXI 3235DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3236 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3237 QEMU_ARCH_ALL) 3238STEXI 3239@item -qmp-pretty @var{dev} 3240@findex -qmp-pretty 3241Like -qmp but uses pretty JSON formatting. 3242ETEXI 3243 3244DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3245 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL) 3246STEXI 3247@item -mon [chardev=]name[,mode=readline|control][,pretty[=on|off]] 3248@findex -mon 3249Setup monitor on chardev @var{name}. @code{pretty} turns on JSON pretty printing 3250easing human reading and debugging. 3251ETEXI 3252 3253DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3254 "-debugcon dev redirect the debug console to char device 'dev'\n", 3255 QEMU_ARCH_ALL) 3256STEXI 3257@item -debugcon @var{dev} 3258@findex -debugcon 3259Redirect the debug console to host device @var{dev} (same devices as the 3260serial port). The debug console is an I/O port which is typically port 32610xe9; writing to that I/O port sends output to this device. 3262The default device is @code{vc} in graphical mode and @code{stdio} in 3263non graphical mode. 3264ETEXI 3265 3266DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3267 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3268STEXI 3269@item -pidfile @var{file} 3270@findex -pidfile 3271Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3272from a script. 3273ETEXI 3274 3275DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3276 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3277STEXI 3278@item -singlestep 3279@findex -singlestep 3280Run the emulation in single step mode. 3281ETEXI 3282 3283DEF("preconfig", 0, QEMU_OPTION_preconfig, \ 3284 "--preconfig pause QEMU before machine is initialized (experimental)\n", 3285 QEMU_ARCH_ALL) 3286STEXI 3287@item --preconfig 3288@findex --preconfig 3289Pause QEMU for interactive configuration before the machine is created, 3290which allows querying and configuring properties that will affect 3291machine initialization. Use QMP command 'x-exit-preconfig' to exit 3292the preconfig state and move to the next state (i.e. run guest if -S 3293isn't used or pause the second time if -S is used). This option is 3294experimental. 3295ETEXI 3296 3297DEF("S", 0, QEMU_OPTION_S, \ 3298 "-S freeze CPU at startup (use 'c' to start execution)\n", 3299 QEMU_ARCH_ALL) 3300STEXI 3301@item -S 3302@findex -S 3303Do not start CPU at startup (you must type 'c' in the monitor). 3304ETEXI 3305 3306DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3307 "-realtime [mlock=on|off]\n" 3308 " run qemu with realtime features\n" 3309 " mlock=on|off controls mlock support (default: on)\n", 3310 QEMU_ARCH_ALL) 3311STEXI 3312@item -realtime mlock=on|off 3313@findex -realtime 3314Run qemu with realtime features. 3315mlocking qemu and guest memory can be enabled via @option{mlock=on} 3316(enabled by default). 3317ETEXI 3318 3319DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit, 3320 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n" 3321 " run qemu with overcommit hints\n" 3322 " mem-lock=on|off controls memory lock support (default: off)\n" 3323 " cpu-pm=on|off controls cpu power management (default: off)\n", 3324 QEMU_ARCH_ALL) 3325STEXI 3326@item -overcommit mem-lock=on|off 3327@item -overcommit cpu-pm=on|off 3328@findex -overcommit 3329Run qemu with hints about host resource overcommit. The default is 3330to assume that host overcommits all resources. 3331 3332Locking qemu and guest memory can be enabled via @option{mem-lock=on} (disabled 3333by default). This works when host memory is not overcommitted and reduces the 3334worst-case latency for guest. This is equivalent to @option{realtime}. 3335 3336Guest ability to manage power state of host cpus (increasing latency for other 3337processes on the same host cpu, but decreasing latency for guest) can be 3338enabled via @option{cpu-pm=on} (disabled by default). This works best when 3339host CPU is not overcommitted. When used, host estimates of CPU cycle and power 3340utilization will be incorrect, not taking into account guest idle time. 3341ETEXI 3342 3343DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3344 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3345STEXI 3346@item -gdb @var{dev} 3347@findex -gdb 3348Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3349connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3350stdio are reasonable use case. The latter is allowing to start QEMU from 3351within gdb and establish the connection via a pipe: 3352@example 3353(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3354@end example 3355ETEXI 3356 3357DEF("s", 0, QEMU_OPTION_s, \ 3358 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3359 QEMU_ARCH_ALL) 3360STEXI 3361@item -s 3362@findex -s 3363Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3364(@pxref{gdb_usage}). 3365ETEXI 3366 3367DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3368 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3369 QEMU_ARCH_ALL) 3370STEXI 3371@item -d @var{item1}[,...] 3372@findex -d 3373Enable logging of specified items. Use '-d help' for a list of log items. 3374ETEXI 3375 3376DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3377 "-D logfile output log to logfile (default stderr)\n", 3378 QEMU_ARCH_ALL) 3379STEXI 3380@item -D @var{logfile} 3381@findex -D 3382Output log in @var{logfile} instead of to stderr 3383ETEXI 3384 3385DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3386 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3387 QEMU_ARCH_ALL) 3388STEXI 3389@item -dfilter @var{range1}[,...] 3390@findex -dfilter 3391Filter debug output to that relevant to a range of target addresses. The filter 3392spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3393@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3394addresses and sizes required. For example: 3395@example 3396 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3397@end example 3398Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3399the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3400block starting at 0xffffffc00005f000. 3401ETEXI 3402 3403DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3404 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3405 QEMU_ARCH_ALL) 3406STEXI 3407@item -L @var{path} 3408@findex -L 3409Set the directory for the BIOS, VGA BIOS and keymaps. 3410 3411To list all the data directories, use @code{-L help}. 3412ETEXI 3413 3414DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3415 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3416STEXI 3417@item -bios @var{file} 3418@findex -bios 3419Set the filename for the BIOS. 3420ETEXI 3421 3422DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3423 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3424STEXI 3425@item -enable-kvm 3426@findex -enable-kvm 3427Enable KVM full virtualization support. This option is only available 3428if KVM support is enabled when compiling. 3429ETEXI 3430 3431DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \ 3432 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386) 3433STEXI 3434@item -enable-hax 3435@findex -enable-hax 3436Enable HAX (Hardware-based Acceleration eXecution) support. This option 3437is only available if HAX support is enabled when compiling. HAX is only 3438applicable to MAC and Windows platform, and thus does not conflict with 3439KVM. This option is deprecated, use @option{-accel hax} instead. 3440ETEXI 3441 3442DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3443 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3444DEF("xen-create", 0, QEMU_OPTION_xen_create, 3445 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3446 " warning: should not be used when xend is in use\n", 3447 QEMU_ARCH_ALL) 3448DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3449 "-xen-attach attach to existing xen domain\n" 3450 " xend will use this when starting QEMU\n", 3451 QEMU_ARCH_ALL) 3452DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3453 "-xen-domid-restrict restrict set of available xen operations\n" 3454 " to specified domain id. (Does not affect\n" 3455 " xenpv machine type).\n", 3456 QEMU_ARCH_ALL) 3457STEXI 3458@item -xen-domid @var{id} 3459@findex -xen-domid 3460Specify xen guest domain @var{id} (XEN only). 3461@item -xen-create 3462@findex -xen-create 3463Create domain using xen hypercalls, bypassing xend. 3464Warning: should not be used when xend is in use (XEN only). 3465@item -xen-attach 3466@findex -xen-attach 3467Attach to existing xen domain. 3468xend will use this when starting QEMU (XEN only). 3469@findex -xen-domid-restrict 3470Restrict set of available xen operations to specified domain id (XEN only). 3471ETEXI 3472 3473DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3474 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3475STEXI 3476@item -no-reboot 3477@findex -no-reboot 3478Exit instead of rebooting. 3479ETEXI 3480 3481DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3482 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3483STEXI 3484@item -no-shutdown 3485@findex -no-shutdown 3486Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3487This allows for instance switching to monitor to commit changes to the 3488disk image. 3489ETEXI 3490 3491DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3492 "-loadvm [tag|id]\n" \ 3493 " start right away with a saved state (loadvm in monitor)\n", 3494 QEMU_ARCH_ALL) 3495STEXI 3496@item -loadvm @var{file} 3497@findex -loadvm 3498Start right away with a saved state (@code{loadvm} in monitor) 3499ETEXI 3500 3501#ifndef _WIN32 3502DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3503 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3504#endif 3505STEXI 3506@item -daemonize 3507@findex -daemonize 3508Daemonize the QEMU process after initialization. QEMU will not detach from 3509standard IO until it is ready to receive connections on any of its devices. 3510This option is a useful way for external programs to launch QEMU without having 3511to cope with initialization race conditions. 3512ETEXI 3513 3514DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3515 "-option-rom rom load a file, rom, into the option ROM space\n", 3516 QEMU_ARCH_ALL) 3517STEXI 3518@item -option-rom @var{file} 3519@findex -option-rom 3520Load the contents of @var{file} as an option ROM. 3521This option is useful to load things like EtherBoot. 3522ETEXI 3523 3524HXCOMM Silently ignored for compatibility 3525DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3526 3527HXCOMM Options deprecated by -rtc 3528DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3529DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3530 3531DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3532 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3533 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3534 QEMU_ARCH_ALL) 3535 3536STEXI 3537 3538@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3539@findex -rtc 3540Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3541UTC or local time, respectively. @code{localtime} is required for correct date in 3542MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3543format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3544 3545By default the RTC is driven by the host system time. This allows using of the 3546RTC as accurate reference clock inside the guest, specifically if the host 3547time is smoothly following an accurate external reference clock, e.g. via NTP. 3548If you want to isolate the guest time from the host, you can set @option{clock} 3549to @code{rt} instead. To even prevent it from progressing during suspension, 3550you can set it to @code{vm}. 3551 3552Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3553specifically with Windows' ACPI HAL. This option will try to figure out how 3554many timer interrupts were not processed by the Windows guest and will 3555re-inject them. 3556ETEXI 3557 3558DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3559 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3560 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3561 " instruction, enable aligning the host and virtual clocks\n" \ 3562 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3563STEXI 3564@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3565@findex -icount 3566Enable virtual instruction counter. The virtual cpu will execute one 3567instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3568then the virtual cpu speed will be automatically adjusted to keep virtual 3569time within a few seconds of real time. 3570 3571When the virtual cpu is sleeping, the virtual time will advance at default 3572speed unless @option{sleep=on|off} is specified. 3573With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3574instantly whenever the virtual cpu goes to sleep mode and will not advance 3575if no timer is enabled. This behavior give deterministic execution times from 3576the guest point of view. 3577 3578Note that while this option can give deterministic behavior, it does not 3579provide cycle accurate emulation. Modern CPUs contain superscalar out of 3580order cores with complex cache hierarchies. The number of instructions 3581executed often has little or no correlation with actual performance. 3582 3583@option{align=on} will activate the delay algorithm which will try 3584to synchronise the host clock and the virtual clock. The goal is to 3585have a guest running at the real frequency imposed by the shift option. 3586Whenever the guest clock is behind the host clock and if 3587@option{align=on} is specified then we print a message to the user 3588to inform about the delay. 3589Currently this option does not work when @option{shift} is @code{auto}. 3590Note: The sync algorithm will work for those shift values for which 3591the guest clock runs ahead of the host clock. Typically this happens 3592when the shift value is high (how high depends on the host machine). 3593 3594When @option{rr} option is specified deterministic record/replay is enabled. 3595Replay log is written into @var{filename} file in record mode and 3596read from this file in replay mode. 3597 3598Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3599at the start of execution recording. In replay mode this option is used 3600to load the initial VM state. 3601ETEXI 3602 3603DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3604 "-watchdog model\n" \ 3605 " enable virtual hardware watchdog [default=none]\n", 3606 QEMU_ARCH_ALL) 3607STEXI 3608@item -watchdog @var{model} 3609@findex -watchdog 3610Create a virtual hardware watchdog device. Once enabled (by a guest 3611action), the watchdog must be periodically polled by an agent inside 3612the guest or else the guest will be restarted. Choose a model for 3613which your guest has drivers. 3614 3615The @var{model} is the model of hardware watchdog to emulate. Use 3616@code{-watchdog help} to list available hardware models. Only one 3617watchdog can be enabled for a guest. 3618 3619The following models may be available: 3620@table @option 3621@item ib700 3622iBASE 700 is a very simple ISA watchdog with a single timer. 3623@item i6300esb 3624Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3625dual-timer watchdog. 3626@item diag288 3627A virtual watchdog for s390x backed by the diagnose 288 hypercall 3628(currently KVM only). 3629@end table 3630ETEXI 3631 3632DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3633 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \ 3634 " action when watchdog fires [default=reset]\n", 3635 QEMU_ARCH_ALL) 3636STEXI 3637@item -watchdog-action @var{action} 3638@findex -watchdog-action 3639 3640The @var{action} controls what QEMU will do when the watchdog timer 3641expires. 3642The default is 3643@code{reset} (forcefully reset the guest). 3644Other possible actions are: 3645@code{shutdown} (attempt to gracefully shutdown the guest), 3646@code{poweroff} (forcefully poweroff the guest), 3647@code{inject-nmi} (inject a NMI into the guest), 3648@code{pause} (pause the guest), 3649@code{debug} (print a debug message and continue), or 3650@code{none} (do nothing). 3651 3652Note that the @code{shutdown} action requires that the guest responds 3653to ACPI signals, which it may not be able to do in the sort of 3654situations where the watchdog would have expired, and thus 3655@code{-watchdog-action shutdown} is not recommended for production use. 3656 3657Examples: 3658 3659@table @code 3660@item -watchdog i6300esb -watchdog-action pause 3661@itemx -watchdog ib700 3662@end table 3663ETEXI 3664 3665DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3666 "-echr chr set terminal escape character instead of ctrl-a\n", 3667 QEMU_ARCH_ALL) 3668STEXI 3669 3670@item -echr @var{numeric_ascii_value} 3671@findex -echr 3672Change the escape character used for switching to the monitor when using 3673monitor and serial sharing. The default is @code{0x01} when using the 3674@code{-nographic} option. @code{0x01} is equal to pressing 3675@code{Control-a}. You can select a different character from the ascii 3676control keys where 1 through 26 map to Control-a through Control-z. For 3677instance you could use the either of the following to change the escape 3678character to Control-t. 3679@table @code 3680@item -echr 0x14 3681@itemx -echr 20 3682@end table 3683ETEXI 3684 3685DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3686 "-virtioconsole c\n" \ 3687 " set virtio console\n", QEMU_ARCH_ALL) 3688STEXI 3689@item -virtioconsole @var{c} 3690@findex -virtioconsole 3691Set virtio console. 3692This option is deprecated, please use @option{-device virtconsole} instead. 3693ETEXI 3694 3695DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3696 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3697STEXI 3698@item -show-cursor 3699@findex -show-cursor 3700Show cursor. 3701ETEXI 3702 3703DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3704 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3705STEXI 3706@item -tb-size @var{n} 3707@findex -tb-size 3708Set TB size. 3709ETEXI 3710 3711DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3712 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3713 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3714 "-incoming unix:socketpath\n" \ 3715 " prepare for incoming migration, listen on\n" \ 3716 " specified protocol and socket address\n" \ 3717 "-incoming fd:fd\n" \ 3718 "-incoming exec:cmdline\n" \ 3719 " accept incoming migration on given file descriptor\n" \ 3720 " or from given external command\n" \ 3721 "-incoming defer\n" \ 3722 " wait for the URI to be specified via migrate_incoming\n", 3723 QEMU_ARCH_ALL) 3724STEXI 3725@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3726@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3727@findex -incoming 3728Prepare for incoming migration, listen on a given tcp port. 3729 3730@item -incoming unix:@var{socketpath} 3731Prepare for incoming migration, listen on a given unix socket. 3732 3733@item -incoming fd:@var{fd} 3734Accept incoming migration from a given filedescriptor. 3735 3736@item -incoming exec:@var{cmdline} 3737Accept incoming migration as an output from specified external command. 3738 3739@item -incoming defer 3740Wait for the URI to be specified via migrate_incoming. The monitor can 3741be used to change settings (such as migration parameters) prior to issuing 3742the migrate_incoming to allow the migration to begin. 3743ETEXI 3744 3745DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3746 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3747STEXI 3748@item -only-migratable 3749@findex -only-migratable 3750Only allow migratable devices. Devices will not be allowed to enter an 3751unmigratable state. 3752ETEXI 3753 3754DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3755 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3756STEXI 3757@item -nodefaults 3758@findex -nodefaults 3759Don't create default devices. Normally, QEMU sets the default devices like serial 3760port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3761CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3762default devices. 3763ETEXI 3764 3765#ifndef _WIN32 3766DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3767 "-chroot dir chroot to dir just before starting the VM\n", 3768 QEMU_ARCH_ALL) 3769#endif 3770STEXI 3771@item -chroot @var{dir} 3772@findex -chroot 3773Immediately before starting guest execution, chroot to the specified 3774directory. Especially useful in combination with -runas. 3775ETEXI 3776 3777#ifndef _WIN32 3778DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3779 "-runas user change to user id user just before starting the VM\n" \ 3780 " user can be numeric uid:gid instead\n", 3781 QEMU_ARCH_ALL) 3782#endif 3783STEXI 3784@item -runas @var{user} 3785@findex -runas 3786Immediately before starting guest execution, drop root privileges, switching 3787to the specified user. 3788ETEXI 3789 3790DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3791 "-prom-env variable=value\n" 3792 " set OpenBIOS nvram variables\n", 3793 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3794STEXI 3795@item -prom-env @var{variable}=@var{value} 3796@findex -prom-env 3797Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3798ETEXI 3799DEF("semihosting", 0, QEMU_OPTION_semihosting, 3800 "-semihosting semihosting mode\n", 3801 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3802 QEMU_ARCH_MIPS) 3803STEXI 3804@item -semihosting 3805@findex -semihosting 3806Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 3807ETEXI 3808DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 3809 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 3810 " semihosting configuration\n", 3811QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3812QEMU_ARCH_MIPS) 3813STEXI 3814@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 3815@findex -semihosting-config 3816Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 3817@table @option 3818@item target=@code{native|gdb|auto} 3819Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 3820or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 3821during debug sessions and @code{native} otherwise. 3822@item arg=@var{str1},arg=@var{str2},... 3823Allows the user to pass input arguments, and can be used multiple times to build 3824up a list. The old-style @code{-kernel}/@code{-append} method of passing a 3825command line is still supported for backward compatibility. If both the 3826@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 3827specified, the former is passed to semihosting as it always takes precedence. 3828@end table 3829ETEXI 3830DEF("old-param", 0, QEMU_OPTION_old_param, 3831 "-old-param old param mode\n", QEMU_ARCH_ARM) 3832STEXI 3833@item -old-param 3834@findex -old-param (ARM) 3835Old param mode (ARM only). 3836ETEXI 3837 3838DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 3839 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \ 3840 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \ 3841 " Enable seccomp mode 2 system call filter (default 'off').\n" \ 3842 " use 'obsolete' to allow obsolete system calls that are provided\n" \ 3843 " by the kernel, but typically no longer used by modern\n" \ 3844 " C library implementations.\n" \ 3845 " use 'elevateprivileges' to allow or deny QEMU process to elevate\n" \ 3846 " its privileges by blacklisting all set*uid|gid system calls.\n" \ 3847 " The value 'children' will deny set*uid|gid system calls for\n" \ 3848 " main QEMU process but will allow forks and execves to run unprivileged\n" \ 3849 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \ 3850 " blacklisting *fork and execve\n" \ 3851 " use 'resourcecontrol' to disable process affinity and schedular priority\n", 3852 QEMU_ARCH_ALL) 3853STEXI 3854@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}] 3855@findex -sandbox 3856Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 3857disable it. The default is 'off'. 3858@table @option 3859@item obsolete=@var{string} 3860Enable Obsolete system calls 3861@item elevateprivileges=@var{string} 3862Disable set*uid|gid system calls 3863@item spawn=@var{string} 3864Disable *fork and execve 3865@item resourcecontrol=@var{string} 3866Disable process affinity and schedular priority 3867@end table 3868ETEXI 3869 3870DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 3871 "-readconfig <file>\n", QEMU_ARCH_ALL) 3872STEXI 3873@item -readconfig @var{file} 3874@findex -readconfig 3875Read device configuration from @var{file}. This approach is useful when you want to spawn 3876QEMU process with many command line options but you don't want to exceed the command line 3877character limit. 3878ETEXI 3879DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 3880 "-writeconfig <file>\n" 3881 " read/write config file\n", QEMU_ARCH_ALL) 3882STEXI 3883@item -writeconfig @var{file} 3884@findex -writeconfig 3885Write device configuration to @var{file}. The @var{file} can be either filename to save 3886command line and device configuration into file or dash @code{-}) character to print the 3887output to stdout. This can be later used as input file for @code{-readconfig} option. 3888ETEXI 3889HXCOMM Deprecated, same as -no-user-config 3890DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, "", QEMU_ARCH_ALL) 3891DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 3892 "-no-user-config\n" 3893 " do not load default user-provided config files at startup\n", 3894 QEMU_ARCH_ALL) 3895STEXI 3896@item -no-user-config 3897@findex -no-user-config 3898The @code{-no-user-config} option makes QEMU not load any of the user-provided 3899config files on @var{sysconfdir}. 3900ETEXI 3901DEF("trace", HAS_ARG, QEMU_OPTION_trace, 3902 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 3903 " specify tracing options\n", 3904 QEMU_ARCH_ALL) 3905STEXI 3906HXCOMM This line is not accurate, as some sub-options are backend-specific but 3907HXCOMM HX does not support conditional compilation of text. 3908@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 3909@findex -trace 3910@include qemu-option-trace.texi 3911ETEXI 3912 3913HXCOMM Internal use 3914DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 3915DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 3916 3917#ifdef __linux__ 3918DEF("enable-fips", 0, QEMU_OPTION_enablefips, 3919 "-enable-fips enable FIPS 140-2 compliance\n", 3920 QEMU_ARCH_ALL) 3921#endif 3922STEXI 3923@item -enable-fips 3924@findex -enable-fips 3925Enable FIPS 140-2 compliance mode. 3926ETEXI 3927 3928HXCOMM Deprecated by -machine accel=tcg property 3929DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 3930 3931DEF("msg", HAS_ARG, QEMU_OPTION_msg, 3932 "-msg timestamp[=on|off]\n" 3933 " change the format of messages\n" 3934 " on|off controls leading timestamps (default:on)\n", 3935 QEMU_ARCH_ALL) 3936STEXI 3937@item -msg timestamp[=on|off] 3938@findex -msg 3939prepend a timestamp to each log message.(default:on) 3940ETEXI 3941 3942DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 3943 "-dump-vmstate <file>\n" 3944 " Output vmstate information in JSON format to file.\n" 3945 " Use the scripts/vmstate-static-checker.py file to\n" 3946 " check for possible regressions in migration code\n" 3947 " by comparing two such vmstate dumps.\n", 3948 QEMU_ARCH_ALL) 3949STEXI 3950@item -dump-vmstate @var{file} 3951@findex -dump-vmstate 3952Dump json-encoded vmstate information for current machine type to file 3953in @var{file} 3954ETEXI 3955 3956STEXI 3957@end table 3958ETEXI 3959DEFHEADING() 3960 3961DEFHEADING(Generic object creation:) 3962STEXI 3963@table @option 3964ETEXI 3965 3966DEF("object", HAS_ARG, QEMU_OPTION_object, 3967 "-object TYPENAME[,PROP1=VALUE1,...]\n" 3968 " create a new object of type TYPENAME setting properties\n" 3969 " in the order they are specified. Note that the 'id'\n" 3970 " property must be set. These objects are placed in the\n" 3971 " '/objects' path.\n", 3972 QEMU_ARCH_ALL) 3973STEXI 3974@item -object @var{typename}[,@var{prop1}=@var{value1},...] 3975@findex -object 3976Create a new object of type @var{typename} setting properties 3977in the order they are specified. Note that the 'id' 3978property must be set. These objects are placed in the 3979'/objects' path. 3980 3981@table @option 3982 3983@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} 3984 3985Creates a memory file backend object, which can be used to back 3986the guest RAM with huge pages. 3987 3988The @option{id} parameter is a unique ID that will be used to reference this 3989memory region when configuring the @option{-numa} argument. 3990 3991The @option{size} option provides the size of the memory region, and accepts 3992common suffixes, eg @option{500M}. 3993 3994The @option{mem-path} provides the path to either a shared memory or huge page 3995filesystem mount. 3996 3997The @option{share} boolean option determines whether the memory 3998region is marked as private to QEMU, or shared. The latter allows 3999a co-operating external process to access the QEMU memory region. 4000 4001The @option{share} is also required for pvrdma devices due to 4002limitations in the RDMA API provided by Linux. 4003 4004Setting share=on might affect the ability to configure NUMA 4005bindings for the memory backend under some circumstances, see 4006Documentation/vm/numa_memory_policy.txt on the Linux kernel 4007source tree for additional details. 4008 4009Setting the @option{discard-data} boolean option to @var{on} 4010indicates that file contents can be destroyed when QEMU exits, 4011to avoid unnecessarily flushing data to the backing file. Note 4012that @option{discard-data} is only an optimization, and QEMU 4013might not discard file contents if it aborts unexpectedly or is 4014terminated using SIGKILL. 4015 4016The @option{merge} boolean option enables memory merge, also known as 4017MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for 4018memory deduplication. 4019 4020Setting the @option{dump} boolean option to @var{off} excludes the memory from 4021core dumps. This feature is also known as MADV_DONTDUMP. 4022 4023The @option{prealloc} boolean option enables memory preallocation. 4024 4025The @option{host-nodes} option binds the memory range to a list of NUMA host 4026nodes. 4027 4028The @option{policy} option sets the NUMA policy to one of the following values: 4029 4030@table @option 4031@item @var{default} 4032default host policy 4033 4034@item @var{preferred} 4035prefer the given host node list for allocation 4036 4037@item @var{bind} 4038restrict memory allocation to the given host node list 4039 4040@item @var{interleave} 4041interleave memory allocations across the given host node list 4042@end table 4043 4044The @option{align} option specifies the base address alignment when 4045QEMU mmap(2) @option{mem-path}, and accepts common suffixes, eg 4046@option{2M}. Some backend store specified by @option{mem-path} 4047requires an alignment different than the default one used by QEMU, eg 4048the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In 4049such cases, users can specify the required alignment via this option. 4050 4051@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} 4052 4053Creates a memory backend object, which can be used to back the guest RAM. 4054Memory backend objects offer more control than the @option{-m} option that is 4055traditionally used to define guest RAM. Please refer to 4056@option{memory-backend-file} for a description of the options. 4057 4058@item -object memory-backend-memfd,id=@var{id},merge=@var{on|off},dump=@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} 4059 4060Creates an anonymous memory file backend object, which allows QEMU to 4061share the memory with an external process (e.g. when using 4062vhost-user). The memory is allocated with memfd and optional 4063sealing. (Linux only) 4064 4065The @option{seal} option creates a sealed-file, that will block 4066further resizing the memory ('on' by default). 4067 4068The @option{hugetlb} option specify the file to be created resides in 4069the hugetlbfs filesystem (since Linux 4.14). Used in conjunction with 4070the @option{hugetlb} option, the @option{hugetlbsize} option specify 4071the hugetlb page size on systems that support multiple hugetlb page 4072sizes (it must be a power of 2 value supported by the system). 4073 4074In some versions of Linux, the @option{hugetlb} option is incompatible 4075with the @option{seal} option (requires at least Linux 4.16). 4076 4077Please refer to @option{memory-backend-file} for a description of the 4078other options. 4079 4080@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4081 4082Creates a random number generator backend which obtains entropy from 4083a device on the host. The @option{id} parameter is a unique ID that 4084will be used to reference this entropy backend from the @option{virtio-rng} 4085device. The @option{filename} parameter specifies which file to obtain 4086entropy from and if omitted defaults to @option{/dev/random}. 4087 4088@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4089 4090Creates a random number generator backend which obtains entropy from 4091an external daemon running on the host. The @option{id} parameter is 4092a unique ID that will be used to reference this entropy backend from 4093the @option{virtio-rng} device. The @option{chardev} parameter is 4094the unique ID of a character device backend that provides the connection 4095to the RNG daemon. 4096 4097@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4098 4099Creates a TLS anonymous credentials object, which can be used to provide 4100TLS support on network backends. The @option{id} parameter is a unique 4101ID which network backends will use to access the credentials. The 4102@option{endpoint} is either @option{server} or @option{client} depending 4103on whether the QEMU network backend that uses the credentials will be 4104acting as a client or as a server. If @option{verify-peer} is enabled 4105(the default) then once the handshake is completed, the peer credentials 4106will be verified, though this is a no-op for anonymous credentials. 4107 4108The @var{dir} parameter tells QEMU where to find the credential 4109files. For server endpoints, this directory may contain a file 4110@var{dh-params.pem} providing diffie-hellman parameters to use 4111for the TLS server. If the file is missing, QEMU will generate 4112a set of DH parameters at startup. This is a computationally 4113expensive operation that consumes random pool entropy, so it is 4114recommended that a persistent set of parameters be generated 4115upfront and saved. 4116 4117@item -object tls-creds-psk,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/keys/dir}[,username=@var{username}] 4118 4119Creates a TLS Pre-Shared Keys (PSK) credentials object, which can be used to provide 4120TLS support on network backends. The @option{id} parameter is a unique 4121ID which network backends will use to access the credentials. The 4122@option{endpoint} is either @option{server} or @option{client} depending 4123on whether the QEMU network backend that uses the credentials will be 4124acting as a client or as a server. For clients only, @option{username} 4125is the username which will be sent to the server. If omitted 4126it defaults to ``qemu''. 4127 4128The @var{dir} parameter tells QEMU where to find the keys file. 4129It is called ``@var{dir}/keys.psk'' and contains ``username:key'' 4130pairs. This file can most easily be created using the GnuTLS 4131@code{psktool} program. 4132 4133For server endpoints, @var{dir} may also contain a file 4134@var{dh-params.pem} providing diffie-hellman parameters to use 4135for the TLS server. If the file is missing, QEMU will generate 4136a set of DH parameters at startup. This is a computationally 4137expensive operation that consumes random pool entropy, so it is 4138recommended that a persistent set of parameters be generated 4139up front and saved. 4140 4141@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} 4142 4143Creates a TLS anonymous credentials object, which can be used to provide 4144TLS support on network backends. The @option{id} parameter is a unique 4145ID which network backends will use to access the credentials. The 4146@option{endpoint} is either @option{server} or @option{client} depending 4147on whether the QEMU network backend that uses the credentials will be 4148acting as a client or as a server. If @option{verify-peer} is enabled 4149(the default) then once the handshake is completed, the peer credentials 4150will be verified. With x509 certificates, this implies that the clients 4151must be provided with valid client certificates too. 4152 4153The @var{dir} parameter tells QEMU where to find the credential 4154files. For server endpoints, this directory may contain a file 4155@var{dh-params.pem} providing diffie-hellman parameters to use 4156for the TLS server. If the file is missing, QEMU will generate 4157a set of DH parameters at startup. This is a computationally 4158expensive operation that consumes random pool entropy, so it is 4159recommended that a persistent set of parameters be generated 4160upfront and saved. 4161 4162For x509 certificate credentials the directory will contain further files 4163providing the x509 certificates. The certificates must be stored 4164in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4165@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4166@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4167 4168For the @var{server-key.pem} and @var{client-key.pem} files which 4169contain sensitive private keys, it is possible to use an encrypted 4170version by providing the @var{passwordid} parameter. This provides 4171the ID of a previously created @code{secret} object containing the 4172password for decryption. 4173 4174The @var{priority} parameter allows to override the global default 4175priority used by gnutls. This can be useful if the system administrator 4176needs to use a weaker set of crypto priorities for QEMU without 4177potentially forcing the weakness onto all applications. Or conversely 4178if one wants wants a stronger default for QEMU than for all other 4179applications, they can do this through this parameter. Its format is 4180a gnutls priority string as described at 4181@url{https://gnutls.org/manual/html_node/Priority-Strings.html}. 4182 4183@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4184 4185Interval @var{t} can't be 0, this filter batches the packet delivery: all 4186packets arriving in a given interval on netdev @var{netdevid} are delayed 4187until the end of the interval. Interval is in microseconds. 4188@option{status} is optional that indicate whether the netfilter is 4189on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4190 4191queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4192 4193@option{all}: the filter is attached both to the receive and the transmit 4194 queue of the netdev (default). 4195 4196@option{rx}: the filter is attached to the receive queue of the netdev, 4197 where it will receive packets sent to the netdev. 4198 4199@option{tx}: the filter is attached to the transmit queue of the netdev, 4200 where it will receive packets sent by the netdev. 4201 4202@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4203 4204filter-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. 4205 4206@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support] 4207 4208filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4209@var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag, 4210filter-redirector will redirect packet with vnet_hdr_len. 4211Create a filter-redirector we need to differ outdev id from indev id, id can not 4212be the same. we can just use indev or outdev, but at least one of indev or outdev 4213need to be specified. 4214 4215@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support] 4216 4217Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4218secondary from primary to keep secondary tcp connection,and rewrite 4219tcp packet to primary from secondary make tcp packet can be handled by 4220client.if it has the vnet_hdr_support flag, we can parse packet with vnet header. 4221 4222usage: 4223colo secondary: 4224-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4225-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4226-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4227 4228@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4229 4230Dump the network traffic on netdev @var{dev} to the file specified by 4231@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4232The file format is libpcap, so it can be analyzed with tools such as tcpdump 4233or Wireshark. 4234 4235@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid}[,vnet_hdr_support] 4236 4237Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4238secondary packet. If the packets are same, we will output primary 4239packet to outdev@var{chardevid}, else we will notify colo-frame 4240do checkpoint and send primary packet to outdev@var{chardevid}. 4241if it has the vnet_hdr_support flag, colo compare will send/recv packet with vnet_hdr_len. 4242 4243we must use it with the help of filter-mirror and filter-redirector. 4244 4245@example 4246 4247primary: 4248-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4249-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4250-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4251-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4252-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4253-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4254-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4255-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4256-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4257-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4258-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4259-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0 4260 4261secondary: 4262-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4263-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4264-chardev socket,id=red0,host=3.3.3.3,port=9003 4265-chardev socket,id=red1,host=3.3.3.3,port=9004 4266-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4267-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4268 4269@end example 4270 4271If you want to know the detail of above command line, you can read 4272the colo-compare git log. 4273 4274@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4275 4276Creates a cryptodev backend which executes crypto opreation from 4277the QEMU cipher APIS. The @var{id} parameter is 4278a unique ID that will be used to reference this cryptodev backend from 4279the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4280which specify the queue number of cryptodev backend, the default of 4281@var{queues} is 1. 4282 4283@example 4284 4285 # qemu-system-x86_64 \ 4286 [...] \ 4287 -object cryptodev-backend-builtin,id=cryptodev0 \ 4288 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4289 [...] 4290@end example 4291 4292@item -object cryptodev-vhost-user,id=@var{id},chardev=@var{chardevid}[,queues=@var{queues}] 4293 4294Creates a vhost-user cryptodev backend, backed by a chardev @var{chardevid}. 4295The @var{id} parameter is a unique ID that will be used to reference this 4296cryptodev backend from the @option{virtio-crypto} device. 4297The chardev should be a unix domain socket backed one. The vhost-user uses 4298a specifically defined protocol to pass vhost ioctl replacement messages 4299to an application on the other end of the socket. 4300The @var{queues} parameter is optional, which specify the queue number 4301of cryptodev backend for multiqueue vhost-user, the default of @var{queues} is 1. 4302 4303@example 4304 4305 # qemu-system-x86_64 \ 4306 [...] \ 4307 -chardev socket,id=chardev0,path=/path/to/socket \ 4308 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \ 4309 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4310 [...] 4311@end example 4312 4313@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4314@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4315 4316Defines a secret to store a password, encryption key, or some other sensitive 4317data. The sensitive data can either be passed directly via the @var{data} 4318parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4319parameter is insecure unless the sensitive data is encrypted. 4320 4321The sensitive data can be provided in raw format (the default), or base64. 4322When encoded as JSON, the raw format only supports valid UTF-8 characters, 4323so base64 is recommended for sending binary data. QEMU will convert from 4324which ever format is provided to the format it needs internally. eg, an 4325RBD password can be provided in raw format, even though it will be base64 4326encoded when passed onto the RBD sever. 4327 4328For added protection, it is possible to encrypt the data associated with 4329a secret using the AES-256-CBC cipher. Use of encryption is indicated 4330by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4331parameter provides the ID of a previously defined secret that contains 4332the AES-256 decryption key. This key should be 32-bytes long and be 4333base64 encoded. The @var{iv} parameter provides the random initialization 4334vector used for encryption of this particular secret and should be a 4335base64 encrypted string of the 16-byte IV. 4336 4337The simplest (insecure) usage is to provide the secret inline 4338 4339@example 4340 4341 # $QEMU -object secret,id=sec0,data=letmein,format=raw 4342 4343@end example 4344 4345The simplest secure usage is to provide the secret via a file 4346 4347 # printf "letmein" > mypasswd.txt 4348 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 4349 4350For greater security, AES-256-CBC should be used. To illustrate usage, 4351consider the openssl command line tool which can encrypt the data. Note 4352that when encrypting, the plaintext must be padded to the cipher block 4353size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4354 4355First a master key needs to be created in base64 encoding: 4356 4357@example 4358 # openssl rand -base64 32 > key.b64 4359 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4360@end example 4361 4362Each secret to be encrypted needs to have a random initialization vector 4363generated. These do not need to be kept secret 4364 4365@example 4366 # openssl rand -base64 16 > iv.b64 4367 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4368@end example 4369 4370The secret to be defined can now be encrypted, in this case we're 4371telling openssl to base64 encode the result, but it could be left 4372as raw bytes if desired. 4373 4374@example 4375 # SECRET=$(printf "letmein" | 4376 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4377@end example 4378 4379When launching QEMU, create a master secret pointing to @code{key.b64} 4380and specify that to be used to decrypt the user password. Pass the 4381contents of @code{iv.b64} to the second secret 4382 4383@example 4384 # $QEMU \ 4385 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4386 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4387 data=$SECRET,iv=$(<iv.b64) 4388@end example 4389 4390@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}] 4391 4392Create a Secure Encrypted Virtualization (SEV) guest object, which can be used 4393to provide the guest memory encryption support on AMD processors. 4394 4395When memory encryption is enabled, one of the physical address bit (aka the 4396C-bit) is utilized to mark if a memory page is protected. The @option{cbitpos} 4397is used to provide the C-bit position. The C-bit position is Host family dependent 4398hence user must provide this value. On EPYC, the value should be 47. 4399 4400When memory encryption is enabled, we loose certain bits in physical address space. 4401The @option{reduced-phys-bits} is used to provide the number of bits we loose in 4402physical address space. Similar to C-bit, the value is Host family dependent. 4403On EPYC, the value should be 5. 4404 4405The @option{sev-device} provides the device file to use for communicating with 4406the SEV firmware running inside AMD Secure Processor. The default device is 4407'/dev/sev'. If hardware supports memory encryption then /dev/sev devices are 4408created by CCP driver. 4409 4410The @option{policy} provides the guest policy to be enforced by the SEV firmware 4411and restrict what configuration and operational commands can be performed on this 4412guest by the hypervisor. The policy should be provided by the guest owner and is 4413bound to the guest and cannot be changed throughout the lifetime of the guest. 4414The default is 0. 4415 4416If guest @option{policy} allows sharing the key with another SEV guest then 4417@option{handle} can be use to provide handle of the guest from which to share 4418the key. 4419 4420The @option{dh-cert-file} and @option{session-file} provides the guest owner's 4421Public Diffie-Hillman key defined in SEV spec. The PDH and session parameters 4422are used for establishing a cryptographic session with the guest owner to 4423negotiate keys used for attestation. The file must be encoded in base64. 4424 4425e.g to launch a SEV guest 4426@example 4427 # $QEMU \ 4428 ...... 4429 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \ 4430 -machine ...,memory-encryption=sev0 4431 ..... 4432 4433@end example 4434@end table 4435 4436ETEXI 4437 4438 4439HXCOMM This is the last statement. Insert new options before this line! 4440STEXI 4441@end table 4442ETEXI 4443
