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 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 " s390-squash-mcss=on|off controls support for squashing into default css (default=off)\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. Supported machine properties are: 53@table @option 54@item accel=@var{accels1}[:@var{accels2}[:...]] 55This is used to enable an accelerator. Depending on the target architecture, 56kvm, xen, hax or tcg can be available. By default, tcg is used. If there is 57more than one accelerator specified, the next one is used if the previous one 58fails to initialize. 59@item kernel_irqchip=on|off 60Controls in-kernel irqchip support for the chosen accelerator when available. 61@item gfx_passthru=on|off 62Enables IGD GFX passthrough support for the chosen machine when available. 63@item vmport=on|off|auto 64Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 65value based on accel. For accel=xen the default is off otherwise the default 66is on. 67@item kvm_shadow_mem=size 68Defines the size of the KVM shadow MMU. 69@item dump-guest-core=on|off 70Include guest memory in a core dump. The default is on. 71@item mem-merge=on|off 72Enables or disables memory merge support. This feature, when supported by 73the host, de-duplicates identical memory pages among VMs instances 74(enabled by default). 75@item aes-key-wrap=on|off 76Enables or disables AES key wrapping support on s390-ccw hosts. This feature 77controls whether AES wrapping keys will be created to allow 78execution of AES cryptographic functions. The default is on. 79@item dea-key-wrap=on|off 80Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 81controls whether DEA wrapping keys will be created to allow 82execution of DEA cryptographic functions. The default is on. 83@item nvdimm=on|off 84Enables or disables NVDIMM support. The default is off. 85@item s390-squash-mcss=on|off 86Enables or disables squashing subchannels into the default css. 87The default is off. 88@end table 89ETEXI 90 91HXCOMM Deprecated by -machine 92DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 93 94DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 95 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 96STEXI 97@item -cpu @var{model} 98@findex -cpu 99Select CPU model (@code{-cpu help} for list and additional feature selection) 100ETEXI 101 102DEF("accel", HAS_ARG, QEMU_OPTION_accel, 103 "-accel [accel=]accelerator[,thread=single|multi]\n" 104 " select accelerator (kvm, xen, hax or tcg; use 'help' for a list)\n" 105 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) 106STEXI 107@item -accel @var{name}[,prop=@var{value}[,...]] 108@findex -accel 109This is used to enable an accelerator. Depending on the target architecture, 110kvm, xen, hax or tcg can be available. By default, tcg is used. If there is 111more than one accelerator specified, the next one is used if the previous one 112fails to initialize. 113@table @option 114@item thread=single|multi 115Controls number of TCG threads. When the TCG is multi-threaded there will be one 116thread per vCPU therefor taking advantage of additional host cores. The default 117is to enable multi-threading where both the back-end and front-ends support it and 118no incompatible TCG features have been enabled (e.g. icount/replay). 119@end table 120ETEXI 121 122DEF("smp", HAS_ARG, QEMU_OPTION_smp, 123 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 124 " set the number of CPUs to 'n' [default=1]\n" 125 " maxcpus= maximum number of total cpus, including\n" 126 " offline CPUs for hotplug, etc\n" 127 " cores= number of CPU cores on one socket\n" 128 " threads= number of threads on one CPU core\n" 129 " sockets= number of discrete sockets in the system\n", 130 QEMU_ARCH_ALL) 131STEXI 132@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 133@findex -smp 134Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 135CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 136to 4. 137For the PC target, the number of @var{cores} per socket, the number 138of @var{threads} per cores and the total number of @var{sockets} can be 139specified. Missing values will be computed. If any on the three values is 140given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 141specifies the maximum number of hotpluggable CPUs. 142ETEXI 143 144DEF("numa", HAS_ARG, QEMU_OPTION_numa, 145 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 146 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n" 147 "-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL) 148STEXI 149@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 150@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}] 151@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance} 152@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] 153@findex -numa 154Define a NUMA node and assign RAM and VCPUs to it. 155Set the NUMA distance from a source node to a destination node. 156 157Legacy VCPU assignment uses @samp{cpus} option where 158@var{firstcpu} and @var{lastcpu} are CPU indexes. Each 159@samp{cpus} option represent a contiguous range of CPU indexes 160(or a single VCPU if @var{lastcpu} is omitted). A non-contiguous 161set of VCPUs can be represented by providing multiple @samp{cpus} 162options. If @samp{cpus} is omitted on all nodes, VCPUs are automatically 163split between them. 164 165For example, the following option assigns VCPUs 0, 1, 2 and 5 to 166a NUMA node: 167@example 168-numa node,cpus=0-2,cpus=5 169@end example 170 171@samp{cpu} option is a new alternative to @samp{cpus} option 172which uses @samp{socket-id|core-id|thread-id} properties to assign 173CPU objects to a @var{node} using topology layout properties of CPU. 174The set of properties is machine specific, and depends on used 175machine type/@samp{smp} options. It could be queried with 176@samp{hotpluggable-cpus} monitor command. 177@samp{node-id} property specifies @var{node} to which CPU object 178will be assigned, it's required for @var{node} to be declared 179with @samp{node} option before it's used with @samp{cpu} option. 180 181For example: 182@example 183-M pc \ 184-smp 1,sockets=2,maxcpus=2 \ 185-numa node,nodeid=0 -numa node,nodeid=1 \ 186-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 187@end example 188 189@samp{mem} assigns a given RAM amount to a node. @samp{memdev} 190assigns RAM from a given memory backend device to a node. If 191@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is 192split equally between them. 193 194@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, 195if one node uses @samp{memdev}, all of them have to use it. 196 197@var{source} and @var{destination} are NUMA node IDs. 198@var{distance} is the NUMA distance from @var{source} to @var{destination}. 199The distance from a node to itself is always 10. If any pair of nodes is 200given a distance, then all pairs must be given distances. Although, when 201distances are only given in one direction for each pair of nodes, then 202the distances in the opposite directions are assumed to be the same. If, 203however, an asymmetrical pair of distances is given for even one node 204pair, then all node pairs must be provided distance values for both 205directions, even when they are symmetrical. When a node is unreachable 206from another node, set the pair's distance to 255. 207 208Note that the -@option{numa} option doesn't allocate any of the 209specified resources, it just assigns existing resources to NUMA 210nodes. This means that one still has to use the @option{-m}, 211@option{-smp} options to allocate RAM and VCPUs respectively. 212 213ETEXI 214 215DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 216 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 217 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 218STEXI 219@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 220@findex -add-fd 221 222Add a file descriptor to an fd set. Valid options are: 223 224@table @option 225@item fd=@var{fd} 226This option defines the file descriptor of which a duplicate is added to fd set. 227The file descriptor cannot be stdin, stdout, or stderr. 228@item set=@var{set} 229This option defines the ID of the fd set to add the file descriptor to. 230@item opaque=@var{opaque} 231This option defines a free-form string that can be used to describe @var{fd}. 232@end table 233 234You can open an image using pre-opened file descriptors from an fd set: 235@example 236qemu-system-i386 237-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 238-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 239-drive file=/dev/fdset/2,index=0,media=disk 240@end example 241ETEXI 242 243DEF("set", HAS_ARG, QEMU_OPTION_set, 244 "-set group.id.arg=value\n" 245 " set <arg> parameter for item <id> of type <group>\n" 246 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 247STEXI 248@item -set @var{group}.@var{id}.@var{arg}=@var{value} 249@findex -set 250Set parameter @var{arg} for item @var{id} of type @var{group} 251ETEXI 252 253DEF("global", HAS_ARG, QEMU_OPTION_global, 254 "-global driver.property=value\n" 255 "-global driver=driver,property=property,value=value\n" 256 " set a global default for a driver property\n", 257 QEMU_ARCH_ALL) 258STEXI 259@item -global @var{driver}.@var{prop}=@var{value} 260@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 261@findex -global 262Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 263 264@example 265qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img 266@end example 267 268In particular, you can use this to set driver properties for devices which are 269created automatically by the machine model. To create a device which is not 270created automatically and set properties on it, use -@option{device}. 271 272-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 273driver=@var{driver},property=@var{prop},value=@var{value}. The 274longhand syntax works even when @var{driver} contains a dot. 275ETEXI 276 277DEF("boot", HAS_ARG, QEMU_OPTION_boot, 278 "-boot [order=drives][,once=drives][,menu=on|off]\n" 279 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 280 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 281 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 282 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 283 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 284 QEMU_ARCH_ALL) 285STEXI 286@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] 287@findex -boot 288Specify boot order @var{drives} as a string of drive letters. Valid 289drive letters depend on the target architecture. The x86 PC uses: a, b 290(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 291from network adapter 1-4), hard disk boot is the default. To apply a 292particular boot order only on the first startup, specify it via 293@option{once}. Note that the @option{order} or @option{once} parameter 294should not be used together with the @option{bootindex} property of 295devices, since the firmware implementations normally do not support both 296at the same time. 297 298Interactive boot menus/prompts can be enabled via @option{menu=on} as far 299as firmware/BIOS supports them. The default is non-interactive boot. 300 301A splash picture could be passed to bios, enabling user to show it as logo, 302when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 303supports them. Currently Seabios for X86 system support it. 304limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 305format(true color). The resolution should be supported by the SVGA mode, so 306the recommended is 320x240, 640x480, 800x640. 307 308A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 309when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 310reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 311system support it. 312 313Do strict boot via @option{strict=on} as far as firmware/BIOS 314supports it. This only effects when boot priority is changed by 315bootindex options. The default is non-strict boot. 316 317@example 318# try to boot from network first, then from hard disk 319qemu-system-i386 -boot order=nc 320# boot from CD-ROM first, switch back to default order after reboot 321qemu-system-i386 -boot once=d 322# boot with a splash picture for 5 seconds. 323qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 324@end example 325 326Note: The legacy format '-boot @var{drives}' is still supported but its 327use is discouraged as it may be removed from future versions. 328ETEXI 329 330DEF("m", HAS_ARG, QEMU_OPTION_m, 331 "-m [size=]megs[,slots=n,maxmem=size]\n" 332 " configure guest RAM\n" 333 " size: initial amount of guest memory\n" 334 " slots: number of hotplug slots (default: none)\n" 335 " maxmem: maximum amount of guest memory (default: none)\n" 336 "NOTE: Some architectures might enforce a specific granularity\n", 337 QEMU_ARCH_ALL) 338STEXI 339@item -m [size=]@var{megs}[,slots=n,maxmem=size] 340@findex -m 341Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 342Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 343megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 344could be used to set amount of hotpluggable memory slots and maximum amount of 345memory. Note that @var{maxmem} must be aligned to the page size. 346 347For example, the following command-line sets the guest startup RAM size to 3481GB, creates 3 slots to hotplug additional memory and sets the maximum 349memory the guest can reach to 4GB: 350 351@example 352qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 353@end example 354 355If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 356be enabled and the guest startup RAM will never increase. 357ETEXI 358 359DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 360 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 361STEXI 362@item -mem-path @var{path} 363@findex -mem-path 364Allocate guest RAM from a temporarily created file in @var{path}. 365ETEXI 366 367DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 368 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 369 QEMU_ARCH_ALL) 370STEXI 371@item -mem-prealloc 372@findex -mem-prealloc 373Preallocate memory when using -mem-path. 374ETEXI 375 376DEF("k", HAS_ARG, QEMU_OPTION_k, 377 "-k language use keyboard layout (for example 'fr' for French)\n", 378 QEMU_ARCH_ALL) 379STEXI 380@item -k @var{language} 381@findex -k 382Use keyboard layout @var{language} (for example @code{fr} for 383French). This option is only needed where it is not easy to get raw PC 384keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses 385display). You don't normally need to use it on PC/Linux or PC/Windows 386hosts. 387 388The available layouts are: 389@example 390ar de-ch es fo fr-ca hu ja mk no pt-br sv 391da en-gb et fr fr-ch is lt nl pl ru th 392de en-us fi fr-be hr it lv nl-be pt sl tr 393@end example 394 395The default is @code{en-us}. 396ETEXI 397 398 399DEF("audio-help", 0, QEMU_OPTION_audio_help, 400 "-audio-help print list of audio drivers and their options\n", 401 QEMU_ARCH_ALL) 402STEXI 403@item -audio-help 404@findex -audio-help 405Will show the audio subsystem help: list of drivers, tunable 406parameters. 407ETEXI 408 409DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 410 "-soundhw c1,... enable audio support\n" 411 " and only specified sound cards (comma separated list)\n" 412 " use '-soundhw help' to get the list of supported cards\n" 413 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 414STEXI 415@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 416@findex -soundhw 417Enable audio and selected sound hardware. Use 'help' to print all 418available sound hardware. 419 420@example 421qemu-system-i386 -soundhw sb16,adlib disk.img 422qemu-system-i386 -soundhw es1370 disk.img 423qemu-system-i386 -soundhw ac97 disk.img 424qemu-system-i386 -soundhw hda disk.img 425qemu-system-i386 -soundhw all disk.img 426qemu-system-i386 -soundhw help 427@end example 428 429Note that Linux's i810_audio OSS kernel (for AC97) module might 430require manually specifying clocking. 431 432@example 433modprobe i810_audio clocking=48000 434@end example 435ETEXI 436 437DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 438 "-balloon none disable balloon device\n" 439 "-balloon virtio[,addr=str]\n" 440 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL) 441STEXI 442@item -balloon none 443@findex -balloon 444Disable balloon device. 445@item -balloon virtio[,addr=@var{addr}] 446Enable virtio balloon device (default), optionally with PCI address 447@var{addr}. 448ETEXI 449 450DEF("device", HAS_ARG, QEMU_OPTION_device, 451 "-device driver[,prop[=value][,...]]\n" 452 " add device (based on driver)\n" 453 " prop=value,... sets driver properties\n" 454 " use '-device help' to print all possible drivers\n" 455 " use '-device driver,help' to print all possible properties\n", 456 QEMU_ARCH_ALL) 457STEXI 458@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 459@findex -device 460Add device @var{driver}. @var{prop}=@var{value} sets driver 461properties. Valid properties depend on the driver. To get help on 462possible drivers and properties, use @code{-device help} and 463@code{-device @var{driver},help}. 464 465Some drivers are: 466@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}] 467 468Add an IPMI BMC. This is a simulation of a hardware management 469interface processor that normally sits on a system. It provides 470a watchdog and the ability to reset and power control the system. 471You need to connect this to an IPMI interface to make it useful 472 473The IPMI slave address to use for the BMC. The default is 0x20. 474This address is the BMC's address on the I2C network of management 475controllers. If you don't know what this means, it is safe to ignore 476it. 477 478@table @option 479@item bmc=@var{id} 480The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 481@item slave_addr=@var{val} 482Define slave address to use for the BMC. The default is 0x20. 483@item sdrfile=@var{file} 484file containing raw Sensor Data Records (SDR) data. The default is none. 485@item fruareasize=@var{val} 486size of a Field Replaceable Unit (FRU) area. The default is 1024. 487@item frudatafile=@var{file} 488file containing raw Field Replaceable Unit (FRU) inventory data. The default is none. 489@end table 490 491@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}] 492 493Add a connection to an external IPMI BMC simulator. Instead of 494locally emulating the BMC like the above item, instead connect 495to an external entity that provides the IPMI services. 496 497A connection is made to an external BMC simulator. If you do this, it 498is strongly recommended that you use the "reconnect=" chardev option 499to reconnect to the simulator if the connection is lost. Note that if 500this is not used carefully, it can be a security issue, as the 501interface has the ability to send resets, NMIs, and power off the VM. 502It's best if QEMU makes a connection to an external simulator running 503on a secure port on localhost, so neither the simulator nor QEMU is 504exposed to any outside network. 505 506See the "lanserv/README.vm" file in the OpenIPMI library for more 507details on the external interface. 508 509@item -device isa-ipmi-kcs,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 510 511Add a KCS IPMI interafce on the ISA bus. This also adds a 512corresponding ACPI and SMBIOS entries, if appropriate. 513 514@table @option 515@item bmc=@var{id} 516The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above. 517@item ioport=@var{val} 518Define the I/O address of the interface. The default is 0xca0 for KCS. 519@item irq=@var{val} 520Define the interrupt to use. The default is 5. To disable interrupts, 521set this to 0. 522@end table 523 524@item -device isa-ipmi-bt,bmc=@var{id}[,ioport=@var{val}][,irq=@var{val}] 525 526Like the KCS interface, but defines a BT interface. The default port is 5270xe4 and the default interrupt is 5. 528 529ETEXI 530 531DEF("name", HAS_ARG, QEMU_OPTION_name, 532 "-name string1[,process=string2][,debug-threads=on|off]\n" 533 " set the name of the guest\n" 534 " string1 sets the window title and string2 the process name (on Linux)\n" 535 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 536 " NOTE: The thread names are for debugging and not a stable API.\n", 537 QEMU_ARCH_ALL) 538STEXI 539@item -name @var{name} 540@findex -name 541Sets the @var{name} of the guest. 542This name will be displayed in the SDL window caption. 543The @var{name} will also be used for the VNC server. 544Also optionally set the top visible process name in Linux. 545Naming of individual threads can also be enabled on Linux to aid debugging. 546ETEXI 547 548DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 549 "-uuid %08x-%04x-%04x-%04x-%012x\n" 550 " specify machine UUID\n", QEMU_ARCH_ALL) 551STEXI 552@item -uuid @var{uuid} 553@findex -uuid 554Set system UUID. 555ETEXI 556 557STEXI 558@end table 559ETEXI 560DEFHEADING() 561 562DEFHEADING(Block device options) 563STEXI 564@table @option 565ETEXI 566 567DEF("fda", HAS_ARG, QEMU_OPTION_fda, 568 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 569DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 570STEXI 571@item -fda @var{file} 572@itemx -fdb @var{file} 573@findex -fda 574@findex -fdb 575Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 576ETEXI 577 578DEF("hda", HAS_ARG, QEMU_OPTION_hda, 579 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 580DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 581DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 582 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 583DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 584STEXI 585@item -hda @var{file} 586@itemx -hdb @var{file} 587@itemx -hdc @var{file} 588@itemx -hdd @var{file} 589@findex -hda 590@findex -hdb 591@findex -hdc 592@findex -hdd 593Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 594ETEXI 595 596DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 597 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 598 QEMU_ARCH_ALL) 599STEXI 600@item -cdrom @var{file} 601@findex -cdrom 602Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 603@option{-cdrom} at the same time). You can use the host CD-ROM by 604using @file{/dev/cdrom} as filename (@pxref{host_drives}). 605ETEXI 606 607DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, 608 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n" 609 " [,cache.direct=on|off][,cache.no-flush=on|off]\n" 610 " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n" 611 " [,driver specific parameters...]\n" 612 " configure a block backend\n", QEMU_ARCH_ALL) 613STEXI 614@item -blockdev @var{option}[,@var{option}[,@var{option}[,...]]] 615@findex -blockdev 616 617Define a new block driver node. Some of the options apply to all block drivers, 618other options are only accepted for a specific block driver. See below for a 619list of generic options and options for the most common block drivers. 620 621Options that expect a reference to another node (e.g. @code{file}) can be 622given in two ways. Either you specify the node name of an already existing node 623(file=@var{node-name}), or you define a new node inline, adding options 624for the referenced node after a dot (file.filename=@var{path},file.aio=native). 625 626A block driver node created with @option{-blockdev} can be used for a guest 627device by specifying its node name for the @code{drive} property in a 628@option{-device} argument that defines a block device. 629 630@table @option 631@item Valid options for any block driver node: 632 633@table @code 634@item driver 635Specifies the block driver to use for the given node. 636@item node-name 637This defines the name of the block driver node by which it will be referenced 638later. The name must be unique, i.e. it must not match the name of a different 639block driver node, or (if you use @option{-drive} as well) the ID of a drive. 640 641If no node name is specified, it is automatically generated. The generated node 642name is not intended to be predictable and changes between QEMU invocations. 643For the top level, an explicit node name must be specified. 644@item read-only 645Open the node read-only. Guest write attempts will fail. 646@item cache.direct 647The host page cache can be avoided with @option{cache.direct=on}. This will 648attempt to do disk IO directly to the guest's memory. QEMU may still perform an 649internal copy of the data. 650@item cache.no-flush 651In case you don't care about data integrity over host failures, you can use 652@option{cache.no-flush=on}. This option tells QEMU that it never needs to write 653any data to the disk but can instead keep things in cache. If anything goes 654wrong, like your host losing power, the disk storage getting disconnected 655accidentally, etc. your image will most probably be rendered unusable. 656@item discard=@var{discard} 657@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls 658whether @code{discard} (also known as @code{trim} or @code{unmap}) requests are 659ignored or passed to the filesystem. Some machine types may not support 660discard requests. 661@item detect-zeroes=@var{detect-zeroes} 662@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 663conversion of plain zero writes by the OS to driver specific optimized 664zero write commands. You may even choose "unmap" if @var{discard} is set 665to "unmap" to allow a zero write to be converted to an @code{unmap} operation. 666@end table 667 668@item Driver-specific options for @code{file} 669 670This is the protocol-level block driver for accessing regular files. 671 672@table @code 673@item filename 674The path to the image file in the local filesystem 675@item aio 676Specifies the AIO backend (threads/native, default: threads) 677@end table 678Example: 679@example 680-blockdev driver=file,node-name=disk,filename=disk.img 681@end example 682 683@item Driver-specific options for @code{raw} 684 685This is the image format block driver for raw images. It is usually 686stacked on top of a protocol level block driver such as @code{file}. 687 688@table @code 689@item file 690Reference to or definition of the data source block driver node 691(e.g. a @code{file} driver node) 692@end table 693Example 1: 694@example 695-blockdev driver=file,node-name=disk_file,filename=disk.img 696-blockdev driver=raw,node-name=disk,file=disk_file 697@end example 698Example 2: 699@example 700-blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img 701@end example 702 703@item Driver-specific options for @code{qcow2} 704 705This is the image format block driver for qcow2 images. It is usually 706stacked on top of a protocol level block driver such as @code{file}. 707 708@table @code 709@item file 710Reference to or definition of the data source block driver node 711(e.g. a @code{file} driver node) 712 713@item backing 714Reference to or definition of the backing file block device (default is taken 715from the image file). It is allowed to pass an empty string here in order to 716disable the default backing file. 717 718@item lazy-refcounts 719Whether to enable the lazy refcounts feature (on/off; default is taken from the 720image file) 721 722@item cache-size 723The maximum total size of the L2 table and refcount block caches in bytes 724(default: 1048576 bytes or 8 clusters, whichever is larger) 725 726@item l2-cache-size 727The maximum size of the L2 table cache in bytes 728(default: 4/5 of the total cache size) 729 730@item refcount-cache-size 731The maximum size of the refcount block cache in bytes 732(default: 1/5 of the total cache size) 733 734@item cache-clean-interval 735Clean unused entries in the L2 and refcount caches. The interval is in seconds. 736The default value is 0 and it disables this feature. 737 738@item pass-discard-request 739Whether discard requests to the qcow2 device should be forwarded to the data 740source (on/off; default: on if discard=unmap is specified, off otherwise) 741 742@item pass-discard-snapshot 743Whether discard requests for the data source should be issued when a snapshot 744operation (e.g. deleting a snapshot) frees clusters in the qcow2 file (on/off; 745default: on) 746 747@item pass-discard-other 748Whether discard requests for the data source should be issued on other 749occasions where a cluster gets freed (on/off; default: off) 750 751@item overlap-check 752Which overlap checks to perform for writes to the image 753(none/constant/cached/all; default: cached). For details or finer 754granularity control refer to the QAPI documentation of @code{blockdev-add}. 755@end table 756 757Example 1: 758@example 759-blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2 760-blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216 761@end example 762Example 2: 763@example 764-blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2 765@end example 766 767@item Driver-specific options for other drivers 768Please refer to the QAPI documentation of the @code{blockdev-add} QMP command. 769 770@end table 771 772ETEXI 773 774DEF("drive", HAS_ARG, QEMU_OPTION_drive, 775 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 776 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n" 777 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 778 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n" 779 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 780 " [,readonly=on|off][,copy-on-read=on|off]\n" 781 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 782 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 783 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 784 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 785 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 786 " [[,iops_size=is]]\n" 787 " [[,group=g]]\n" 788 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 789STEXI 790@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 791@findex -drive 792 793Define a new drive. This includes creating a block driver node (the backend) as 794well as a guest device, and is mostly a shortcut for defining the corresponding 795@option{-blockdev} and @option{-device} options. 796 797@option{-drive} accepts all options that are accepted by @option{-blockdev}. In 798addition, it knows the following options: 799 800@table @option 801@item file=@var{file} 802This option defines which disk image (@pxref{disk_images}) to use with 803this drive. If the filename contains comma, you must double it 804(for instance, "file=my,,file" to use file "my,file"). 805 806Special files such as iSCSI devices can be specified using protocol 807specific URLs. See the section for "Device URL Syntax" for more information. 808@item if=@var{interface} 809This option defines on which type on interface the drive is connected. 810Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, none. 811@item bus=@var{bus},unit=@var{unit} 812These options define where is connected the drive by defining the bus number and 813the unit id. 814@item index=@var{index} 815This option defines where is connected the drive by using an index in the list 816of available connectors of a given interface type. 817@item media=@var{media} 818This option defines the type of the media: disk or cdrom. 819@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}] 820These options have the same definition as they have in @option{-hdachs}. 821@item snapshot=@var{snapshot} 822@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 823(see @option{-snapshot}). 824@item cache=@var{cache} 825@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" 826and controls how the host cache is used to access block data. This is a 827shortcut that sets the @option{cache.direct} and @option{cache.no-flush} 828options (as in @option{-blockdev}), and additionally @option{cache.writeback}, 829which provides a default for the @option{write-cache} option of block guest 830devices (as in @option{-device}). The modes correspond to the following 831settings: 832 833@c Our texi2pod.pl script doesn't support @multitable, so fall back to using 834@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage 835@c and the HTML output. 836@example 837@ │ cache.writeback cache.direct cache.no-flush 838─────────────┼───────────────────────────────────────────────── 839writeback │ on off off 840none │ on on off 841writethrough │ off off off 842directsync │ off on off 843unsafe │ on off on 844@end example 845 846The default mode is @option{cache=writeback}. 847 848@item aio=@var{aio} 849@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 850@item format=@var{format} 851Specify which disk @var{format} will be used rather than detecting 852the format. Can be used to specify format=raw to avoid interpreting 853an untrusted format header. 854@item serial=@var{serial} 855This option specifies the serial number to assign to the device. 856@item addr=@var{addr} 857Specify the controller's PCI address (if=virtio only). 858@item werror=@var{action},rerror=@var{action} 859Specify which @var{action} to take on write and read errors. Valid actions are: 860"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 861"report" (report the error to the guest), "enospc" (pause QEMU only if the 862host disk is full; report the error to the guest otherwise). 863The default setting is @option{werror=enospc} and @option{rerror=report}. 864@item copy-on-read=@var{copy-on-read} 865@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 866file sectors into the image file. 867@item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w} 868Specify bandwidth throttling limits in bytes per second, either for all request 869types or for reads or writes only. Small values can lead to timeouts or hangs 870inside the guest. A safe minimum for disks is 2 MB/s. 871@item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm} 872Specify bursts in bytes per second, either for all request types or for reads 873or writes only. Bursts allow the guest I/O to spike above the limit 874temporarily. 875@item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w} 876Specify request rate limits in requests per second, either for all request 877types or for reads or writes only. 878@item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm} 879Specify bursts in requests per second, either for all request types or for reads 880or writes only. Bursts allow the guest I/O to spike above the limit 881temporarily. 882@item iops_size=@var{is} 883Let every @var{is} bytes of a request count as a new request for iops 884throttling purposes. Use this option to prevent guests from circumventing iops 885limits by sending fewer but larger requests. 886@item group=@var{g} 887Join a throttling quota group with given name @var{g}. All drives that are 888members of the same group are accounted for together. Use this option to 889prevent guests from circumventing throttling limits by using many small disks 890instead of a single larger disk. 891@end table 892 893By default, the @option{cache.writeback=on} mode is used. It will report data 894writes as completed as soon as the data is present in the host page cache. 895This is safe as long as your guest OS makes sure to correctly flush disk caches 896where needed. If your guest OS does not handle volatile disk write caches 897correctly and your host crashes or loses power, then the guest may experience 898data corruption. 899 900For such guests, you should consider using @option{cache.writeback=off}. This 901means that the host page cache will be used to read and write data, but write 902notification will be sent to the guest only after QEMU has made sure to flush 903each write to the disk. Be aware that this has a major impact on performance. 904 905When using the @option{-snapshot} option, unsafe caching is always used. 906 907Copy-on-read avoids accessing the same backing file sectors repeatedly and is 908useful when the backing file is over a slow network. By default copy-on-read 909is off. 910 911Instead of @option{-cdrom} you can use: 912@example 913qemu-system-i386 -drive file=file,index=2,media=cdrom 914@end example 915 916Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 917use: 918@example 919qemu-system-i386 -drive file=file,index=0,media=disk 920qemu-system-i386 -drive file=file,index=1,media=disk 921qemu-system-i386 -drive file=file,index=2,media=disk 922qemu-system-i386 -drive file=file,index=3,media=disk 923@end example 924 925You can open an image using pre-opened file descriptors from an fd set: 926@example 927qemu-system-i386 928-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 929-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 930-drive file=/dev/fdset/2,index=0,media=disk 931@end example 932 933You can connect a CDROM to the slave of ide0: 934@example 935qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 936@end example 937 938If you don't specify the "file=" argument, you define an empty drive: 939@example 940qemu-system-i386 -drive if=ide,index=1,media=cdrom 941@end example 942 943Instead of @option{-fda}, @option{-fdb}, you can use: 944@example 945qemu-system-i386 -drive file=file,index=0,if=floppy 946qemu-system-i386 -drive file=file,index=1,if=floppy 947@end example 948 949By default, @var{interface} is "ide" and @var{index} is automatically 950incremented: 951@example 952qemu-system-i386 -drive file=a -drive file=b" 953@end example 954is interpreted like: 955@example 956qemu-system-i386 -hda a -hdb b 957@end example 958ETEXI 959 960DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 961 "-mtdblock file use 'file' as on-board Flash memory image\n", 962 QEMU_ARCH_ALL) 963STEXI 964@item -mtdblock @var{file} 965@findex -mtdblock 966Use @var{file} as on-board Flash memory image. 967ETEXI 968 969DEF("sd", HAS_ARG, QEMU_OPTION_sd, 970 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 971STEXI 972@item -sd @var{file} 973@findex -sd 974Use @var{file} as SecureDigital card image. 975ETEXI 976 977DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 978 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 979STEXI 980@item -pflash @var{file} 981@findex -pflash 982Use @var{file} as a parallel flash image. 983ETEXI 984 985DEF("snapshot", 0, QEMU_OPTION_snapshot, 986 "-snapshot write to temporary files instead of disk image files\n", 987 QEMU_ARCH_ALL) 988STEXI 989@item -snapshot 990@findex -snapshot 991Write to temporary files instead of disk image files. In this case, 992the raw disk image you use is not written back. You can however force 993the write back by pressing @key{C-a s} (@pxref{disk_images}). 994ETEXI 995 996DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \ 997 "-hdachs c,h,s[,t]\n" \ 998 " force hard disk 0 physical geometry and the optional BIOS\n" \ 999 " translation (t=none or lba) (usually QEMU can guess them)\n", 1000 QEMU_ARCH_ALL) 1001STEXI 1002@item -hdachs @var{c},@var{h},@var{s},[,@var{t}] 1003@findex -hdachs 1004Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <= 1005@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS 1006translation mode (@var{t}=none, lba or auto). Usually QEMU can guess 1007all those parameters. This option is deprecated, please use 1008@code{-device ide-hd,cyls=c,heads=h,secs=s,...} instead. 1009ETEXI 1010 1011DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 1012 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 1013 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n" 1014 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n" 1015 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n" 1016 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n" 1017 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n" 1018 " [[,throttling.iops-size=is]]\n", 1019 QEMU_ARCH_ALL) 1020 1021STEXI 1022 1023@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}] 1024@findex -fsdev 1025Define a new file system device. Valid options are: 1026@table @option 1027@item @var{fsdriver} 1028This option specifies the fs driver backend to use. 1029Currently "local", "handle" and "proxy" file system drivers are supported. 1030@item id=@var{id} 1031Specifies identifier for this device 1032@item path=@var{path} 1033Specifies the export path for the file system device. Files under 1034this path will be available to the 9p client on the guest. 1035@item security_model=@var{security_model} 1036Specifies the security model to be used for this export path. 1037Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1038In "passthrough" security model, files are stored using the same 1039credentials as they are created on the guest. This requires QEMU 1040to run as root. In "mapped-xattr" security model, some of the file 1041attributes like uid, gid, mode bits and link target are stored as 1042file attributes. For "mapped-file" these attributes are stored in the 1043hidden .virtfs_metadata directory. Directories exported by this security model cannot 1044interact with other unix tools. "none" security model is same as 1045passthrough except the sever won't report failures if it fails to 1046set file attributes like ownership. Security model is mandatory 1047only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 1048security model as a parameter. 1049@item writeout=@var{writeout} 1050This is an optional argument. The only supported value is "immediate". 1051This means that host page cache will be used to read and write data but 1052write notification will be sent to the guest only when the data has been 1053reported as written by the storage subsystem. 1054@item readonly 1055Enables exporting 9p share as a readonly mount for guests. By default 1056read-write access is given. 1057@item socket=@var{socket} 1058Enables proxy filesystem driver to use passed socket file for communicating 1059with virtfs-proxy-helper 1060@item sock_fd=@var{sock_fd} 1061Enables proxy filesystem driver to use passed socket descriptor for 1062communicating with virtfs-proxy-helper. Usually a helper like libvirt 1063will create socketpair and pass one of the fds as sock_fd 1064@item fmode=@var{fmode} 1065Specifies the default mode for newly created files on the host. Works only 1066with security models "mapped-xattr" and "mapped-file". 1067@item dmode=@var{dmode} 1068Specifies the default mode for newly created directories on the host. Works 1069only with security models "mapped-xattr" and "mapped-file". 1070@end table 1071 1072-fsdev option is used along with -device driver "virtio-9p-pci". 1073@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 1074Options for virtio-9p-pci driver are: 1075@table @option 1076@item fsdev=@var{id} 1077Specifies the id value specified along with -fsdev option 1078@item mount_tag=@var{mount_tag} 1079Specifies the tag name to be used by the guest to mount this export point 1080@end table 1081 1082ETEXI 1083 1084DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 1085 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 1086 " [,id=id][,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n", 1087 QEMU_ARCH_ALL) 1088 1089STEXI 1090 1091@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}] 1092@findex -virtfs 1093 1094The general form of a Virtual File system pass-through options are: 1095@table @option 1096@item @var{fsdriver} 1097This option specifies the fs driver backend to use. 1098Currently "local", "handle" and "proxy" file system drivers are supported. 1099@item id=@var{id} 1100Specifies identifier for this device 1101@item path=@var{path} 1102Specifies the export path for the file system device. Files under 1103this path will be available to the 9p client on the guest. 1104@item security_model=@var{security_model} 1105Specifies the security model to be used for this export path. 1106Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 1107In "passthrough" security model, files are stored using the same 1108credentials as they are created on the guest. This requires QEMU 1109to run as root. In "mapped-xattr" security model, some of the file 1110attributes like uid, gid, mode bits and link target are stored as 1111file attributes. For "mapped-file" these attributes are stored in the 1112hidden .virtfs_metadata directory. Directories exported by this security model cannot 1113interact with other unix tools. "none" security model is same as 1114passthrough except the sever won't report failures if it fails to 1115set file attributes like ownership. Security model is mandatory only 1116for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 1117model as a parameter. 1118@item writeout=@var{writeout} 1119This is an optional argument. The only supported value is "immediate". 1120This means that host page cache will be used to read and write data but 1121write notification will be sent to the guest only when the data has been 1122reported as written by the storage subsystem. 1123@item readonly 1124Enables exporting 9p share as a readonly mount for guests. By default 1125read-write access is given. 1126@item socket=@var{socket} 1127Enables proxy filesystem driver to use passed socket file for 1128communicating with virtfs-proxy-helper. Usually a helper like libvirt 1129will create socketpair and pass one of the fds as sock_fd 1130@item sock_fd 1131Enables proxy filesystem driver to use passed 'sock_fd' as the socket 1132descriptor for interfacing with virtfs-proxy-helper 1133@item fmode=@var{fmode} 1134Specifies the default mode for newly created files on the host. Works only 1135with security models "mapped-xattr" and "mapped-file". 1136@item dmode=@var{dmode} 1137Specifies the default mode for newly created directories on the host. Works 1138only with security models "mapped-xattr" and "mapped-file". 1139@end table 1140ETEXI 1141 1142DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 1143 "-virtfs_synth Create synthetic file system image\n", 1144 QEMU_ARCH_ALL) 1145STEXI 1146@item -virtfs_synth 1147@findex -virtfs_synth 1148Create synthetic file system image 1149ETEXI 1150 1151STEXI 1152@end table 1153ETEXI 1154DEFHEADING() 1155 1156DEFHEADING(USB options) 1157STEXI 1158@table @option 1159ETEXI 1160 1161DEF("usb", 0, QEMU_OPTION_usb, 1162 "-usb enable the USB driver (if it is not used by default yet)\n", 1163 QEMU_ARCH_ALL) 1164STEXI 1165@item -usb 1166@findex -usb 1167Enable the USB driver (if it is not used by default yet). 1168ETEXI 1169 1170DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 1171 "-usbdevice name add the host or guest USB device 'name'\n", 1172 QEMU_ARCH_ALL) 1173STEXI 1174 1175@item -usbdevice @var{devname} 1176@findex -usbdevice 1177Add the USB device @var{devname}. Note that this option is deprecated, 1178please use @code{-device usb-...} instead. @xref{usb_devices}. 1179 1180@table @option 1181 1182@item mouse 1183Virtual Mouse. This will override the PS/2 mouse emulation when activated. 1184 1185@item tablet 1186Pointer device that uses absolute coordinates (like a touchscreen). This 1187means QEMU is able to report the mouse position without having to grab the 1188mouse. Also overrides the PS/2 mouse emulation when activated. 1189 1190@item disk:[format=@var{format}]:@var{file} 1191Mass storage device based on file. The optional @var{format} argument 1192will be used rather than detecting the format. Can be used to specify 1193@code{format=raw} to avoid interpreting an untrusted format header. 1194 1195@item host:@var{bus}.@var{addr} 1196Pass through the host device identified by @var{bus}.@var{addr} (Linux only). 1197 1198@item host:@var{vendor_id}:@var{product_id} 1199Pass through the host device identified by @var{vendor_id}:@var{product_id} 1200(Linux only). 1201 1202@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev} 1203Serial converter to host character device @var{dev}, see @code{-serial} for the 1204available devices. 1205 1206@item braille 1207Braille device. This will use BrlAPI to display the braille output on a real 1208or fake device. 1209 1210@item net:@var{options} 1211Network adapter that supports CDC ethernet and RNDIS protocols. 1212 1213@end table 1214ETEXI 1215 1216STEXI 1217@end table 1218ETEXI 1219DEFHEADING() 1220 1221DEFHEADING(Display options) 1222STEXI 1223@table @option 1224ETEXI 1225 1226DEF("display", HAS_ARG, QEMU_OPTION_display, 1227 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 1228 " [,window_close=on|off][,gl=on|off]\n" 1229 "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n" 1230 "-display vnc=<display>[,<optargs>]\n" 1231 "-display curses\n" 1232 "-display none" 1233 " select display type\n" 1234 "The default display is equivalent to\n" 1235#if defined(CONFIG_GTK) 1236 "\t\"-display gtk\"\n" 1237#elif defined(CONFIG_SDL) 1238 "\t\"-display sdl\"\n" 1239#elif defined(CONFIG_COCOA) 1240 "\t\"-display cocoa\"\n" 1241#elif defined(CONFIG_VNC) 1242 "\t\"-vnc localhost:0,to=99,id=default\"\n" 1243#else 1244 "\t\"-display none\"\n" 1245#endif 1246 , QEMU_ARCH_ALL) 1247STEXI 1248@item -display @var{type} 1249@findex -display 1250Select type of display to use. This option is a replacement for the 1251old style -sdl/-curses/... options. Valid values for @var{type} are 1252@table @option 1253@item sdl 1254Display video output via SDL (usually in a separate graphics 1255window; see the SDL documentation for other possibilities). 1256@item curses 1257Display video output via curses. For graphics device models which 1258support a text mode, QEMU can display this output using a 1259curses/ncurses interface. Nothing is displayed when the graphics 1260device is in graphical mode or if the graphics device does not support 1261a text mode. Generally only the VGA device models support text mode. 1262@item none 1263Do not display video output. The guest will still see an emulated 1264graphics card, but its output will not be displayed to the QEMU 1265user. This option differs from the -nographic option in that it 1266only affects what is done with video output; -nographic also changes 1267the destination of the serial and parallel port data. 1268@item gtk 1269Display video output in a GTK window. This interface provides drop-down 1270menus and other UI elements to configure and control the VM during 1271runtime. 1272@item vnc 1273Start a VNC server on display <arg> 1274@end table 1275ETEXI 1276 1277DEF("nographic", 0, QEMU_OPTION_nographic, 1278 "-nographic disable graphical output and redirect serial I/Os to console\n", 1279 QEMU_ARCH_ALL) 1280STEXI 1281@item -nographic 1282@findex -nographic 1283Normally, if QEMU is compiled with graphical window support, it displays 1284output such as guest graphics, guest console, and the QEMU monitor in a 1285window. With this option, you can totally disable graphical output so 1286that QEMU is a simple command line application. The emulated serial port 1287is redirected on the console and muxed with the monitor (unless 1288redirected elsewhere explicitly). Therefore, you can still use QEMU to 1289debug a Linux kernel with a serial console. Use @key{C-a h} for help on 1290switching between the console and monitor. 1291ETEXI 1292 1293DEF("curses", 0, QEMU_OPTION_curses, 1294 "-curses shorthand for -display curses\n", 1295 QEMU_ARCH_ALL) 1296STEXI 1297@item -curses 1298@findex -curses 1299Normally, if QEMU is compiled with graphical window support, it displays 1300output such as guest graphics, guest console, and the QEMU monitor in a 1301window. With this option, QEMU can display the VGA output when in text 1302mode using a curses/ncurses interface. Nothing is displayed in graphical 1303mode. 1304ETEXI 1305 1306DEF("no-frame", 0, QEMU_OPTION_no_frame, 1307 "-no-frame open SDL window without a frame and window decorations\n", 1308 QEMU_ARCH_ALL) 1309STEXI 1310@item -no-frame 1311@findex -no-frame 1312Do not use decorations for SDL windows and start them using the whole 1313available screen space. This makes the using QEMU in a dedicated desktop 1314workspace more convenient. 1315ETEXI 1316 1317DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 1318 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 1319 QEMU_ARCH_ALL) 1320STEXI 1321@item -alt-grab 1322@findex -alt-grab 1323Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 1324affects the special keys (for fullscreen, monitor-mode switching, etc). 1325ETEXI 1326 1327DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 1328 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 1329 QEMU_ARCH_ALL) 1330STEXI 1331@item -ctrl-grab 1332@findex -ctrl-grab 1333Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 1334affects the special keys (for fullscreen, monitor-mode switching, etc). 1335ETEXI 1336 1337DEF("no-quit", 0, QEMU_OPTION_no_quit, 1338 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 1339STEXI 1340@item -no-quit 1341@findex -no-quit 1342Disable SDL window close capability. 1343ETEXI 1344 1345DEF("sdl", 0, QEMU_OPTION_sdl, 1346 "-sdl shorthand for -display sdl\n", QEMU_ARCH_ALL) 1347STEXI 1348@item -sdl 1349@findex -sdl 1350Enable SDL. 1351ETEXI 1352 1353DEF("spice", HAS_ARG, QEMU_OPTION_spice, 1354 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 1355 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 1356 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 1357 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 1358 " [,tls-ciphers=<list>]\n" 1359 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 1360 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 1361 " [,sasl][,password=<secret>][,disable-ticketing]\n" 1362 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 1363 " [,jpeg-wan-compression=[auto|never|always]]\n" 1364 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 1365 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 1366 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 1367 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 1368 " [,gl=[on|off]][,rendernode=<file>]\n" 1369 " enable spice\n" 1370 " at least one of {port, tls-port} is mandatory\n", 1371 QEMU_ARCH_ALL) 1372STEXI 1373@item -spice @var{option}[,@var{option}[,...]] 1374@findex -spice 1375Enable the spice remote desktop protocol. Valid options are 1376 1377@table @option 1378 1379@item port=<nr> 1380Set the TCP port spice is listening on for plaintext channels. 1381 1382@item addr=<addr> 1383Set the IP address spice is listening on. Default is any address. 1384 1385@item ipv4 1386@itemx ipv6 1387@itemx unix 1388Force using the specified IP version. 1389 1390@item password=<secret> 1391Set the password you need to authenticate. 1392 1393@item sasl 1394Require that the client use SASL to authenticate with the spice. 1395The exact choice of authentication method used is controlled from the 1396system / user's SASL configuration file for the 'qemu' service. This 1397is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1398unprivileged user, an environment variable SASL_CONF_PATH can be used 1399to make it search alternate locations for the service config. 1400While some SASL auth methods can also provide data encryption (eg GSSAPI), 1401it is recommended that SASL always be combined with the 'tls' and 1402'x509' settings to enable use of SSL and server certificates. This 1403ensures a data encryption preventing compromise of authentication 1404credentials. 1405 1406@item disable-ticketing 1407Allow client connects without authentication. 1408 1409@item disable-copy-paste 1410Disable copy paste between the client and the guest. 1411 1412@item disable-agent-file-xfer 1413Disable spice-vdagent based file-xfer between the client and the guest. 1414 1415@item tls-port=<nr> 1416Set the TCP port spice is listening on for encrypted channels. 1417 1418@item x509-dir=<dir> 1419Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1420 1421@item x509-key-file=<file> 1422@itemx x509-key-password=<file> 1423@itemx x509-cert-file=<file> 1424@itemx x509-cacert-file=<file> 1425@itemx x509-dh-key-file=<file> 1426The x509 file names can also be configured individually. 1427 1428@item tls-ciphers=<list> 1429Specify which ciphers to use. 1430 1431@item tls-channel=[main|display|cursor|inputs|record|playback] 1432@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1433Force specific channel to be used with or without TLS encryption. The 1434options can be specified multiple times to configure multiple 1435channels. The special name "default" can be used to set the default 1436mode. For channels which are not explicitly forced into one mode the 1437spice client is allowed to pick tls/plaintext as he pleases. 1438 1439@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1440Configure image compression (lossless). 1441Default is auto_glz. 1442 1443@item jpeg-wan-compression=[auto|never|always] 1444@itemx zlib-glz-wan-compression=[auto|never|always] 1445Configure wan image compression (lossy for slow links). 1446Default is auto. 1447 1448@item streaming-video=[off|all|filter] 1449Configure video stream detection. Default is off. 1450 1451@item agent-mouse=[on|off] 1452Enable/disable passing mouse events via vdagent. Default is on. 1453 1454@item playback-compression=[on|off] 1455Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1456 1457@item seamless-migration=[on|off] 1458Enable/disable spice seamless migration. Default is off. 1459 1460@item gl=[on|off] 1461Enable/disable OpenGL context. Default is off. 1462 1463@item rendernode=<file> 1464DRM render node for OpenGL rendering. If not specified, it will pick 1465the first available. (Since 2.9) 1466 1467@end table 1468ETEXI 1469 1470DEF("portrait", 0, QEMU_OPTION_portrait, 1471 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1472 QEMU_ARCH_ALL) 1473STEXI 1474@item -portrait 1475@findex -portrait 1476Rotate graphical output 90 deg left (only PXA LCD). 1477ETEXI 1478 1479DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1480 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1481 QEMU_ARCH_ALL) 1482STEXI 1483@item -rotate @var{deg} 1484@findex -rotate 1485Rotate graphical output some deg left (only PXA LCD). 1486ETEXI 1487 1488DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1489 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1490 " select video card type\n", QEMU_ARCH_ALL) 1491STEXI 1492@item -vga @var{type} 1493@findex -vga 1494Select type of VGA card to emulate. Valid values for @var{type} are 1495@table @option 1496@item cirrus 1497Cirrus Logic GD5446 Video card. All Windows versions starting from 1498Windows 95 should recognize and use this graphic card. For optimal 1499performances, use 16 bit color depth in the guest and the host OS. 1500(This card was the default before QEMU 2.2) 1501@item std 1502Standard VGA card with Bochs VBE extensions. If your guest OS 1503supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1504to use high resolution modes (>= 1280x1024x16) then you should use 1505this option. (This card is the default since QEMU 2.2) 1506@item vmware 1507VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1508recent XFree86/XOrg server or Windows guest with a driver for this 1509card. 1510@item qxl 1511QXL paravirtual graphic card. It is VGA compatible (including VESA 15122.0 VBE support). Works best with qxl guest drivers installed though. 1513Recommended choice when using the spice protocol. 1514@item tcx 1515(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1516sun4m machines and offers both 8-bit and 24-bit colour depths at a 1517fixed resolution of 1024x768. 1518@item cg3 1519(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1520for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1521resolutions aimed at people wishing to run older Solaris versions. 1522@item virtio 1523Virtio VGA card. 1524@item none 1525Disable VGA card. 1526@end table 1527ETEXI 1528 1529DEF("full-screen", 0, QEMU_OPTION_full_screen, 1530 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1531STEXI 1532@item -full-screen 1533@findex -full-screen 1534Start in full screen. 1535ETEXI 1536 1537DEF("g", 1, QEMU_OPTION_g , 1538 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1539 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1540STEXI 1541@item -g @var{width}x@var{height}[x@var{depth}] 1542@findex -g 1543Set the initial graphical resolution and depth (PPC, SPARC only). 1544ETEXI 1545 1546DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1547 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL) 1548STEXI 1549@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1550@findex -vnc 1551Normally, if QEMU is compiled with graphical window support, it displays 1552output such as guest graphics, guest console, and the QEMU monitor in a 1553window. With this option, you can have QEMU listen on VNC display 1554@var{display} and redirect the VGA display over the VNC session. It is 1555very useful to enable the usb tablet device when using this option 1556(option @option{-device usb-tablet}). When using the VNC display, you 1557must use the @option{-k} parameter to set the keyboard layout if you are 1558not using en-us. Valid syntax for the @var{display} is 1559 1560@table @option 1561 1562@item to=@var{L} 1563 1564With this option, QEMU will try next available VNC @var{display}s, until the 1565number @var{L}, if the origianlly defined "-vnc @var{display}" is not 1566available, e.g. port 5900+@var{display} is already used by another 1567application. By default, to=0. 1568 1569@item @var{host}:@var{d} 1570 1571TCP connections will only be allowed from @var{host} on display @var{d}. 1572By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1573be omitted in which case the server will accept connections from any host. 1574 1575@item unix:@var{path} 1576 1577Connections will be allowed over UNIX domain sockets where @var{path} is the 1578location of a unix socket to listen for connections on. 1579 1580@item none 1581 1582VNC is initialized but not started. The monitor @code{change} command 1583can be used to later start the VNC server. 1584 1585@end table 1586 1587Following the @var{display} value there may be one or more @var{option} flags 1588separated by commas. Valid options are 1589 1590@table @option 1591 1592@item reverse 1593 1594Connect to a listening VNC client via a ``reverse'' connection. The 1595client is specified by the @var{display}. For reverse network 1596connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1597is a TCP port number, not a display number. 1598 1599@item websocket 1600 1601Opens an additional TCP listening port dedicated to VNC Websocket connections. 1602If a bare @var{websocket} option is given, the Websocket port is 16035700+@var{display}. An alternative port can be specified with the 1604syntax @code{websocket}=@var{port}. 1605 1606If @var{host} is specified connections will only be allowed from this host. 1607It is possible to control the websocket listen address independently, using 1608the syntax @code{websocket}=@var{host}:@var{port}. 1609 1610If no TLS credentials are provided, the websocket connection runs in 1611unencrypted mode. If TLS credentials are provided, the websocket connection 1612requires encrypted client connections. 1613 1614@item password 1615 1616Require that password based authentication is used for client connections. 1617 1618The password must be set separately using the @code{set_password} command in 1619the @ref{pcsys_monitor}. The syntax to change your password is: 1620@code{set_password <protocol> <password>} where <protocol> could be either 1621"vnc" or "spice". 1622 1623If you would like to change <protocol> password expiration, you should use 1624@code{expire_password <protocol> <expiration-time>} where expiration time could 1625be one of the following options: now, never, +seconds or UNIX time of 1626expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1627to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1628date and time). 1629 1630You can also use keywords "now" or "never" for the expiration time to 1631allow <protocol> password to expire immediately or never expire. 1632 1633@item tls-creds=@var{ID} 1634 1635Provides the ID of a set of TLS credentials to use to secure the 1636VNC server. They will apply to both the normal VNC server socket 1637and the websocket socket (if enabled). Setting TLS credentials 1638will cause the VNC server socket to enable the VeNCrypt auth 1639mechanism. The credentials should have been previously created 1640using the @option{-object tls-creds} argument. 1641 1642The @option{tls-creds} parameter obsoletes the @option{tls}, 1643@option{x509}, and @option{x509verify} options, and as such 1644it is not permitted to set both new and old type options at 1645the same time. 1646 1647@item tls 1648 1649Require that client use TLS when communicating with the VNC server. This 1650uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1651attack. It is recommended that this option be combined with either the 1652@option{x509} or @option{x509verify} options. 1653 1654This option is now deprecated in favor of using the @option{tls-creds} 1655argument. 1656 1657@item x509=@var{/path/to/certificate/dir} 1658 1659Valid if @option{tls} is specified. Require that x509 credentials are used 1660for negotiating the TLS session. The server will send its x509 certificate 1661to the client. It is recommended that a password be set on the VNC server 1662to provide authentication of the client when this is used. The path following 1663this option specifies where the x509 certificates are to be loaded from. 1664See the @ref{vnc_security} section for details on generating certificates. 1665 1666This option is now deprecated in favour of using the @option{tls-creds} 1667argument. 1668 1669@item x509verify=@var{/path/to/certificate/dir} 1670 1671Valid if @option{tls} is specified. Require that x509 credentials are used 1672for negotiating the TLS session. The server will send its x509 certificate 1673to the client, and request that the client send its own x509 certificate. 1674The server will validate the client's certificate against the CA certificate, 1675and reject clients when validation fails. If the certificate authority is 1676trusted, this is a sufficient authentication mechanism. You may still wish 1677to set a password on the VNC server as a second authentication layer. The 1678path following this option specifies where the x509 certificates are to 1679be loaded from. See the @ref{vnc_security} section for details on generating 1680certificates. 1681 1682This option is now deprecated in favour of using the @option{tls-creds} 1683argument. 1684 1685@item sasl 1686 1687Require that the client use SASL to authenticate with the VNC server. 1688The exact choice of authentication method used is controlled from the 1689system / user's SASL configuration file for the 'qemu' service. This 1690is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1691unprivileged user, an environment variable SASL_CONF_PATH can be used 1692to make it search alternate locations for the service config. 1693While some SASL auth methods can also provide data encryption (eg GSSAPI), 1694it is recommended that SASL always be combined with the 'tls' and 1695'x509' settings to enable use of SSL and server certificates. This 1696ensures a data encryption preventing compromise of authentication 1697credentials. See the @ref{vnc_security} section for details on using 1698SASL authentication. 1699 1700@item acl 1701 1702Turn on access control lists for checking of the x509 client certificate 1703and SASL party. For x509 certs, the ACL check is made against the 1704certificate's distinguished name. This is something that looks like 1705@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1706made against the username, which depending on the SASL plugin, may 1707include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1708When the @option{acl} flag is set, the initial access list will be 1709empty, with a @code{deny} policy. Thus no one will be allowed to 1710use the VNC server until the ACLs have been loaded. This can be 1711achieved using the @code{acl} monitor command. 1712 1713@item lossy 1714 1715Enable lossy compression methods (gradient, JPEG, ...). If this 1716option is set, VNC client may receive lossy framebuffer updates 1717depending on its encoding settings. Enabling this option can save 1718a lot of bandwidth at the expense of quality. 1719 1720@item non-adaptive 1721 1722Disable adaptive encodings. Adaptive encodings are enabled by default. 1723An adaptive encoding will try to detect frequently updated screen regions, 1724and send updates in these regions using a lossy encoding (like JPEG). 1725This can be really helpful to save bandwidth when playing videos. Disabling 1726adaptive encodings restores the original static behavior of encodings 1727like Tight. 1728 1729@item share=[allow-exclusive|force-shared|ignore] 1730 1731Set display sharing policy. 'allow-exclusive' allows clients to ask 1732for exclusive access. As suggested by the rfb spec this is 1733implemented by dropping other connections. Connecting multiple 1734clients in parallel requires all clients asking for a shared session 1735(vncviewer: -shared switch). This is the default. 'force-shared' 1736disables exclusive client access. Useful for shared desktop sessions, 1737where you don't want someone forgetting specify -shared disconnect 1738everybody else. 'ignore' completely ignores the shared flag and 1739allows everybody connect unconditionally. Doesn't conform to the rfb 1740spec but is traditional QEMU behavior. 1741 1742@item key-delay-ms 1743 1744Set keyboard delay, for key down and key up events, in milliseconds. 1745Default is 1. Keyboards are low-bandwidth devices, so this slowdown 1746can help the device and guest to keep up and not lose events in case 1747events are arriving in bulk. Possible causes for the latter are flaky 1748network connections, or scripts for automated testing. 1749 1750@end table 1751ETEXI 1752 1753STEXI 1754@end table 1755ETEXI 1756ARCHHEADING(, QEMU_ARCH_I386) 1757 1758ARCHHEADING(i386 target only, QEMU_ARCH_I386) 1759STEXI 1760@table @option 1761ETEXI 1762 1763DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1764 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1765 QEMU_ARCH_I386) 1766STEXI 1767@item -win2k-hack 1768@findex -win2k-hack 1769Use it when installing Windows 2000 to avoid a disk full bug. After 1770Windows 2000 is installed, you no longer need this option (this option 1771slows down the IDE transfers). 1772ETEXI 1773 1774HXCOMM Deprecated by -rtc 1775DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1776 1777DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1778 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1779 QEMU_ARCH_I386) 1780STEXI 1781@item -no-fd-bootchk 1782@findex -no-fd-bootchk 1783Disable boot signature checking for floppy disks in BIOS. May 1784be needed to boot from old floppy disks. 1785ETEXI 1786 1787DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1788 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1789STEXI 1790@item -no-acpi 1791@findex -no-acpi 1792Disable ACPI (Advanced Configuration and Power Interface) support. Use 1793it if your guest OS complains about ACPI problems (PC target machine 1794only). 1795ETEXI 1796 1797DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1798 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1799STEXI 1800@item -no-hpet 1801@findex -no-hpet 1802Disable HPET support. 1803ETEXI 1804 1805DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1806 "-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" 1807 " ACPI table description\n", QEMU_ARCH_I386) 1808STEXI 1809@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}]...] 1810@findex -acpitable 1811Add ACPI table with specified header fields and context from specified files. 1812For file=, take whole ACPI table from the specified files, including all 1813ACPI headers (possible overridden by other options). 1814For data=, only data 1815portion of the table is used, all header information is specified in the 1816command line. 1817If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id 1818fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order 1819to ensure the field matches required by the Microsoft SLIC spec and the ACPI 1820spec. 1821ETEXI 1822 1823DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1824 "-smbios file=binary\n" 1825 " load SMBIOS entry from binary file\n" 1826 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1827 " [,uefi=on|off]\n" 1828 " specify SMBIOS type 0 fields\n" 1829 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1830 " [,uuid=uuid][,sku=str][,family=str]\n" 1831 " specify SMBIOS type 1 fields\n" 1832 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1833 " [,asset=str][,location=str]\n" 1834 " specify SMBIOS type 2 fields\n" 1835 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1836 " [,sku=str]\n" 1837 " specify SMBIOS type 3 fields\n" 1838 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1839 " [,asset=str][,part=str]\n" 1840 " specify SMBIOS type 4 fields\n" 1841 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1842 " [,asset=str][,part=str][,speed=%d]\n" 1843 " specify SMBIOS type 17 fields\n", 1844 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1845STEXI 1846@item -smbios file=@var{binary} 1847@findex -smbios 1848Load SMBIOS entry from binary file. 1849 1850@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1851Specify SMBIOS type 0 fields 1852 1853@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}] 1854Specify SMBIOS type 1 fields 1855 1856@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}] 1857Specify SMBIOS type 2 fields 1858 1859@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1860Specify SMBIOS type 3 fields 1861 1862@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1863Specify SMBIOS type 4 fields 1864 1865@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}] 1866Specify SMBIOS type 17 fields 1867ETEXI 1868 1869STEXI 1870@end table 1871ETEXI 1872DEFHEADING() 1873 1874DEFHEADING(Network options) 1875STEXI 1876@table @option 1877ETEXI 1878 1879HXCOMM Legacy slirp options (now moved to -net user): 1880#ifdef CONFIG_SLIRP 1881DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1882DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1883DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1884#ifndef _WIN32 1885DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1886#endif 1887#endif 1888 1889DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1890#ifdef CONFIG_SLIRP 1891 "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n" 1892 " [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n" 1893 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n" 1894 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n" 1895 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1896#ifndef _WIN32 1897 "[,smb=dir[,smbserver=addr]]\n" 1898#endif 1899 " configure a user mode network backend with ID 'str',\n" 1900 " its DHCP server and optional services\n" 1901#endif 1902#ifdef _WIN32 1903 "-netdev tap,id=str,ifname=name\n" 1904 " configure a host TAP network backend with ID 'str'\n" 1905#else 1906 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1907 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1908 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1909 " [,poll-us=n]\n" 1910 " configure a host TAP network backend with ID 'str'\n" 1911 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1912 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1913 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1914 " to deconfigure it\n" 1915 " use '[down]script=no' to disable script execution\n" 1916 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1917 " configure it\n" 1918 " use 'fd=h' to connect to an already opened TAP interface\n" 1919 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1920 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1921 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1922 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1923 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1924 " use vhost=on to enable experimental in kernel accelerator\n" 1925 " (only has effect for virtio guests which use MSIX)\n" 1926 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1927 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1928 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1929 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1930 " use 'poll-us=n' to speciy the maximum number of microseconds that could be\n" 1931 " spent on busy polling for vhost net\n" 1932 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1933 " configure a host TAP network backend with ID 'str' that is\n" 1934 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1935 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1936#endif 1937#ifdef __linux__ 1938 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1939 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1940 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1941 " [,rxcookie=rxcookie][,offset=offset]\n" 1942 " configure a network backend with ID 'str' connected to\n" 1943 " an Ethernet over L2TPv3 pseudowire.\n" 1944 " Linux kernel 3.3+ as well as most routers can talk\n" 1945 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1946 " VM to a router and even VM to Host. It is a nearly-universal\n" 1947 " standard (RFC3391). Note - this implementation uses static\n" 1948 " pre-configured tunnels (same as the Linux kernel).\n" 1949 " use 'src=' to specify source address\n" 1950 " use 'dst=' to specify destination address\n" 1951 " use 'udp=on' to specify udp encapsulation\n" 1952 " use 'srcport=' to specify source udp port\n" 1953 " use 'dstport=' to specify destination udp port\n" 1954 " use 'ipv6=on' to force v6\n" 1955 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1956 " well as a weak security measure\n" 1957 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1958 " use 'txcookie=0x012345678' to specify a txcookie\n" 1959 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1960 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1961 " use 'pincounter=on' to work around broken counter handling in peer\n" 1962 " use 'offset=X' to add an extra offset between header and data\n" 1963#endif 1964 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1965 " configure a network backend to connect to another network\n" 1966 " using a socket connection\n" 1967 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1968 " configure a network backend to connect to a multicast maddr and port\n" 1969 " use 'localaddr=addr' to specify the host address to send packets from\n" 1970 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1971 " configure a network backend to connect to another network\n" 1972 " using an UDP tunnel\n" 1973#ifdef CONFIG_VDE 1974 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1975 " configure a network backend to connect to port 'n' of a vde switch\n" 1976 " running on host and listening for incoming connections on 'socketpath'.\n" 1977 " Use group 'groupname' and mode 'octalmode' to change default\n" 1978 " ownership and permissions for communication port.\n" 1979#endif 1980#ifdef CONFIG_NETMAP 1981 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 1982 " attach to the existing netmap-enabled network interface 'name', or to a\n" 1983 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 1984 " netmap device, defaults to '/dev/netmap')\n" 1985#endif 1986 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 1987 " configure a vhost-user network, backed by a chardev 'dev'\n" 1988 "-netdev hubport,id=str,hubid=n\n" 1989 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL) 1990DEF("net", HAS_ARG, QEMU_OPTION_net, 1991 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 1992 " old way to create a new NIC and connect it to VLAN 'n'\n" 1993 " (use the '-device devtype,netdev=str' option if possible instead)\n" 1994 "-net dump[,vlan=n][,file=f][,len=n]\n" 1995 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n" 1996 "-net none use it alone to have zero network devices. If no -net option\n" 1997 " is provided, the default is '-net nic -net user'\n" 1998 "-net [" 1999#ifdef CONFIG_SLIRP 2000 "user|" 2001#endif 2002 "tap|" 2003 "bridge|" 2004#ifdef CONFIG_VDE 2005 "vde|" 2006#endif 2007#ifdef CONFIG_NETMAP 2008 "netmap|" 2009#endif 2010 "socket][,vlan=n][,option][,option][,...]\n" 2011 " old way to initialize a host network interface\n" 2012 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 2013STEXI 2014@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 2015@findex -net 2016Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n} 2017= 0 is the default). The NIC is an e1000 by default on the PC 2018target. Optionally, the MAC address can be changed to @var{mac}, the 2019device address set to @var{addr} (PCI cards only), 2020and a @var{name} can be assigned for use in monitor commands. 2021Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 2022that the card should have; this option currently only affects virtio cards; set 2023@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 2024NIC is created. QEMU can emulate several different models of network card. 2025Valid values for @var{type} are 2026@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er}, 2027@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139}, 2028@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}. 2029Not all devices are supported on all targets. Use @code{-net nic,model=help} 2030for a list of available devices for your target. 2031 2032@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 2033@findex -netdev 2034@item -net user[,@var{option}][,@var{option}][,...] 2035Use the user mode network stack which requires no administrator 2036privilege to run. Valid options are: 2037 2038@table @option 2039@item vlan=@var{n} 2040Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default). 2041 2042@item id=@var{id} 2043@itemx name=@var{name} 2044Assign symbolic name for use in monitor commands. 2045 2046@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must 2047be enabled. If neither is specified both protocols are enabled. 2048 2049@item net=@var{addr}[/@var{mask}] 2050Set IP network address the guest will see. Optionally specify the netmask, 2051either in the form a.b.c.d or as number of valid top-most bits. Default is 205210.0.2.0/24. 2053 2054@item host=@var{addr} 2055Specify the guest-visible address of the host. Default is the 2nd IP in the 2056guest network, i.e. x.x.x.2. 2057 2058@item ipv6-net=@var{addr}[/@var{int}] 2059Set IPv6 network address the guest will see (default is fec0::/64). The 2060network prefix is given in the usual hexadecimal IPv6 address 2061notation. The prefix size is optional, and is given as the number of 2062valid top-most bits (default is 64). 2063 2064@item ipv6-host=@var{addr} 2065Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in 2066the guest network, i.e. xxxx::2. 2067 2068@item restrict=on|off 2069If this option is enabled, the guest will be isolated, i.e. it will not be 2070able to contact the host and no guest IP packets will be routed over the host 2071to the outside. This option does not affect any explicitly set forwarding rules. 2072 2073@item hostname=@var{name} 2074Specifies the client hostname reported by the built-in DHCP server. 2075 2076@item dhcpstart=@var{addr} 2077Specify the first of the 16 IPs the built-in DHCP server can assign. Default 2078is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 2079 2080@item dns=@var{addr} 2081Specify the guest-visible address of the virtual nameserver. The address must 2082be different from the host address. Default is the 3rd IP in the guest network, 2083i.e. x.x.x.3. 2084 2085@item ipv6-dns=@var{addr} 2086Specify the guest-visible address of the IPv6 virtual nameserver. The address 2087must be different from the host address. Default is the 3rd IP in the guest 2088network, i.e. xxxx::3. 2089 2090@item dnssearch=@var{domain} 2091Provides an entry for the domain-search list sent by the built-in 2092DHCP server. More than one domain suffix can be transmitted by specifying 2093this option multiple times. If supported, this will cause the guest to 2094automatically try to append the given domain suffix(es) in case a domain name 2095can not be resolved. 2096 2097Example: 2098@example 2099qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...] 2100@end example 2101 2102@item tftp=@var{dir} 2103When using the user mode network stack, activate a built-in TFTP 2104server. The files in @var{dir} will be exposed as the root of a TFTP server. 2105The TFTP client on the guest must be configured in binary mode (use the command 2106@code{bin} of the Unix TFTP client). 2107 2108@item bootfile=@var{file} 2109When using the user mode network stack, broadcast @var{file} as the BOOTP 2110filename. In conjunction with @option{tftp}, this can be used to network boot 2111a guest from a local directory. 2112 2113Example (using pxelinux): 2114@example 2115qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 2116@end example 2117 2118@item smb=@var{dir}[,smbserver=@var{addr}] 2119When using the user mode network stack, activate a built-in SMB 2120server so that Windows OSes can access to the host files in @file{@var{dir}} 2121transparently. The IP address of the SMB server can be set to @var{addr}. By 2122default the 4th IP in the guest network is used, i.e. x.x.x.4. 2123 2124In the guest Windows OS, the line: 2125@example 212610.0.2.4 smbserver 2127@end example 2128must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 2129or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 2130 2131Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 2132 2133Note that a SAMBA server must be installed on the host OS. 2134QEMU was tested successfully with smbd versions from Red Hat 9, 2135Fedora Core 3 and OpenSUSE 11.x. 2136 2137@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 2138Redirect incoming TCP or UDP connections to the host port @var{hostport} to 2139the guest IP address @var{guestaddr} on guest port @var{guestport}. If 2140@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 2141given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 2142be bound to a specific host interface. If no connection type is set, TCP is 2143used. This option can be given multiple times. 2144 2145For example, to redirect host X11 connection from screen 1 to guest 2146screen 0, use the following: 2147 2148@example 2149# on the host 2150qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...] 2151# this host xterm should open in the guest X11 server 2152xterm -display :1 2153@end example 2154 2155To redirect telnet connections from host port 5555 to telnet port on 2156the guest, use the following: 2157 2158@example 2159# on the host 2160qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...] 2161telnet localhost 5555 2162@end example 2163 2164Then when you use on the host @code{telnet localhost 5555}, you 2165connect to the guest telnet server. 2166 2167@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 2168@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 2169Forward guest TCP connections to the IP address @var{server} on port @var{port} 2170to the character device @var{dev} or to a program executed by @var{cmd:command} 2171which gets spawned for each connection. This option can be given multiple times. 2172 2173You can either use a chardev directly and have that one used throughout QEMU's 2174lifetime, like in the following example: 2175 2176@example 2177# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 2178# the guest accesses it 2179qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...] 2180@end example 2181 2182Or you can execute a command on every TCP connection established by the guest, 2183so that QEMU behaves similar to an inetd process for that virtual server: 2184 2185@example 2186# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 2187# and connect the TCP stream to its stdin/stdout 2188qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 2189@end example 2190 2191@end table 2192 2193Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 2194processed and applied to -net user. Mixing them with the new configuration 2195syntax gives undefined results. Their use for new applications is discouraged 2196as they will be removed from future versions. 2197 2198@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2199@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}] 2200Connect the host TAP network interface @var{name} to VLAN @var{n}. 2201 2202Use the network script @var{file} to configure it and the network script 2203@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 2204automatically provides one. The default network configure script is 2205@file{/etc/qemu-ifup} and the default network deconfigure script is 2206@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 2207to disable script execution. 2208 2209If running QEMU as an unprivileged user, use the network helper 2210@var{helper} to configure the TAP interface and attach it to the bridge. 2211The default network helper executable is @file{/path/to/qemu-bridge-helper} 2212and the default bridge device is @file{br0}. 2213 2214@option{fd}=@var{h} can be used to specify the handle of an already 2215opened host TAP interface. 2216 2217Examples: 2218 2219@example 2220#launch a QEMU instance with the default network script 2221qemu-system-i386 linux.img -net nic -net tap 2222@end example 2223 2224@example 2225#launch a QEMU instance with two NICs, each one connected 2226#to a TAP device 2227qemu-system-i386 linux.img \ 2228 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ 2229 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 2230@end example 2231 2232@example 2233#launch a QEMU instance with the default network helper to 2234#connect a TAP device to bridge br0 2235qemu-system-i386 linux.img \ 2236 -net nic -net tap,"helper=/path/to/qemu-bridge-helper" 2237@end example 2238 2239@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 2240@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}] 2241Connect a host TAP network interface to a host bridge device. 2242 2243Use the network helper @var{helper} to configure the TAP interface and 2244attach it to the bridge. The default network helper executable is 2245@file{/path/to/qemu-bridge-helper} and the default bridge 2246device is @file{br0}. 2247 2248Examples: 2249 2250@example 2251#launch a QEMU instance with the default network helper to 2252#connect a TAP device to bridge br0 2253qemu-system-i386 linux.img -net bridge -net nic,model=virtio 2254@end example 2255 2256@example 2257#launch a QEMU instance with the default network helper to 2258#connect a TAP device to bridge qemubr0 2259qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio 2260@end example 2261 2262@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2263@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 2264 2265Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual 2266machine using a TCP socket connection. If @option{listen} is 2267specified, QEMU waits for incoming connections on @var{port} 2268(@var{host} is optional). @option{connect} is used to connect to 2269another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 2270specifies an already opened TCP socket. 2271 2272Example: 2273@example 2274# launch a first QEMU instance 2275qemu-system-i386 linux.img \ 2276 -net nic,macaddr=52:54:00:12:34:56 \ 2277 -net socket,listen=:1234 2278# connect the VLAN 0 of this instance to the VLAN 0 2279# of the first instance 2280qemu-system-i386 linux.img \ 2281 -net nic,macaddr=52:54:00:12:34:57 \ 2282 -net socket,connect=127.0.0.1:1234 2283@end example 2284 2285@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2286@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 2287 2288Create a VLAN @var{n} shared with another QEMU virtual 2289machines using a UDP multicast socket, effectively making a bus for 2290every QEMU with same multicast address @var{maddr} and @var{port}. 2291NOTES: 2292@enumerate 2293@item 2294Several QEMU can be running on different hosts and share same bus (assuming 2295correct multicast setup for these hosts). 2296@item 2297mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 2298@url{http://user-mode-linux.sf.net}. 2299@item 2300Use @option{fd=h} to specify an already opened UDP multicast socket. 2301@end enumerate 2302 2303Example: 2304@example 2305# launch one QEMU instance 2306qemu-system-i386 linux.img \ 2307 -net nic,macaddr=52:54:00:12:34:56 \ 2308 -net socket,mcast=230.0.0.1:1234 2309# launch another QEMU instance on same "bus" 2310qemu-system-i386 linux.img \ 2311 -net nic,macaddr=52:54:00:12:34:57 \ 2312 -net socket,mcast=230.0.0.1:1234 2313# launch yet another QEMU instance on same "bus" 2314qemu-system-i386 linux.img \ 2315 -net nic,macaddr=52:54:00:12:34:58 \ 2316 -net socket,mcast=230.0.0.1:1234 2317@end example 2318 2319Example (User Mode Linux compat.): 2320@example 2321# launch QEMU instance (note mcast address selected 2322# is UML's default) 2323qemu-system-i386 linux.img \ 2324 -net nic,macaddr=52:54:00:12:34:56 \ 2325 -net socket,mcast=239.192.168.1:1102 2326# launch UML 2327/path/to/linux ubd0=/path/to/root_fs eth0=mcast 2328@end example 2329 2330Example (send packets from host's 1.2.3.4): 2331@example 2332qemu-system-i386 linux.img \ 2333 -net nic,macaddr=52:54:00:12:34:56 \ 2334 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 2335@end example 2336 2337@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}] 2338@itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],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}] 2339Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular 2340protocol to transport Ethernet (and other Layer 2) data frames between 2341two systems. It is present in routers, firewalls and the Linux kernel 2342(from version 3.3 onwards). 2343 2344This transport allows a VM to communicate to another VM, router or firewall directly. 2345 2346@item src=@var{srcaddr} 2347 source address (mandatory) 2348@item dst=@var{dstaddr} 2349 destination address (mandatory) 2350@item udp 2351 select udp encapsulation (default is ip). 2352@item srcport=@var{srcport} 2353 source udp port. 2354@item dstport=@var{dstport} 2355 destination udp port. 2356@item ipv6 2357 force v6, otherwise defaults to v4. 2358@item rxcookie=@var{rxcookie} 2359@itemx txcookie=@var{txcookie} 2360 Cookies are a weak form of security in the l2tpv3 specification. 2361Their function is mostly to prevent misconfiguration. By default they are 32 2362bit. 2363@item cookie64 2364 Set cookie size to 64 bit instead of the default 32 2365@item counter=off 2366 Force a 'cut-down' L2TPv3 with no counter as in 2367draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 2368@item pincounter=on 2369 Work around broken counter handling in peer. This may also help on 2370networks which have packet reorder. 2371@item offset=@var{offset} 2372 Add an extra offset between header and data 2373 2374For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 2375on the remote Linux host 1.2.3.4: 2376@example 2377# Setup tunnel on linux host using raw ip as encapsulation 2378# on 1.2.3.4 2379ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 2380 encap udp udp_sport 16384 udp_dport 16384 2381ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 2382 0xFFFFFFFF peer_session_id 0xFFFFFFFF 2383ifconfig vmtunnel0 mtu 1500 2384ifconfig vmtunnel0 up 2385brctl addif br-lan vmtunnel0 2386 2387 2388# on 4.3.2.1 2389# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 2390 2391qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter 2392 2393 2394@end example 2395 2396@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2397@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 2398Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and 2399listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 2400and MODE @var{octalmode} to change default ownership and permissions for 2401communication port. This option is only available if QEMU has been compiled 2402with vde support enabled. 2403 2404Example: 2405@example 2406# launch vde switch 2407vde_switch -F -sock /tmp/myswitch 2408# launch QEMU instance 2409qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch 2410@end example 2411 2412@item -netdev hubport,id=@var{id},hubid=@var{hubid} 2413 2414Create a hub port on QEMU "vlan" @var{hubid}. 2415 2416The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single 2417netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the 2418required hub automatically. 2419 2420@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 2421 2422Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 2423be a unix domain socket backed one. The vhost-user uses a specifically defined 2424protocol to pass vhost ioctl replacement messages to an application on the other 2425end of the socket. On non-MSIX guests, the feature can be forced with 2426@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2427be created for multiqueue vhost-user. 2428 2429Example: 2430@example 2431qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2432 -numa node,memdev=mem \ 2433 -chardev socket,id=chr0,path=/path/to/socket \ 2434 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2435 -device virtio-net-pci,netdev=net0 2436@end example 2437 2438@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}] 2439Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default). 2440At most @var{len} bytes (64k by default) per packet are stored. The file format is 2441libpcap, so it can be analyzed with tools such as tcpdump or Wireshark. 2442Note: For devices created with '-netdev', use '-object filter-dump,...' instead. 2443 2444@item -net none 2445Indicate that no network devices should be configured. It is used to 2446override the default configuration (@option{-net nic -net user}) which 2447is activated if no @option{-net} options are provided. 2448ETEXI 2449 2450STEXI 2451@end table 2452ETEXI 2453DEFHEADING() 2454 2455DEFHEADING(Character device options) 2456STEXI 2457 2458The general form of a character device option is: 2459@table @option 2460ETEXI 2461 2462DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2463 "-chardev help\n" 2464 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2465 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2466 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off]\n" 2467 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n" 2468 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds]\n" 2469 " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n" 2470 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2471 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2472 " [,logfile=PATH][,logappend=on|off]\n" 2473 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2474 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2475 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2476 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" 2477 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2478 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2479#ifdef _WIN32 2480 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2481 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2482#else 2483 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2484 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" 2485#endif 2486#ifdef CONFIG_BRLAPI 2487 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2488#endif 2489#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2490 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2491 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2492 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2493#endif 2494#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2495 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2496 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" 2497#endif 2498#if defined(CONFIG_SPICE) 2499 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2500 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" 2501#endif 2502 , QEMU_ARCH_ALL 2503) 2504 2505STEXI 2506@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}] 2507@findex -chardev 2508Backend is one of: 2509@option{null}, 2510@option{socket}, 2511@option{udp}, 2512@option{msmouse}, 2513@option{vc}, 2514@option{ringbuf}, 2515@option{file}, 2516@option{pipe}, 2517@option{console}, 2518@option{serial}, 2519@option{pty}, 2520@option{stdio}, 2521@option{braille}, 2522@option{tty}, 2523@option{parallel}, 2524@option{parport}, 2525@option{spicevmc}. 2526@option{spiceport}. 2527The specific backend will determine the applicable options. 2528 2529Use "-chardev help" to print all available chardev backend types. 2530 2531All devices must have an id, which can be any string up to 127 characters long. 2532It is used to uniquely identify this device in other command line directives. 2533 2534A character device may be used in multiplexing mode by multiple front-ends. 2535Specify @option{mux=on} to enable this mode. 2536A multiplexer is a "1:N" device, and here the "1" end is your specified chardev 2537backend, and the "N" end is the various parts of QEMU that can talk to a chardev. 2538If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will 2539create a multiplexer with your specified ID, and you can then configure multiple 2540front ends to use that chardev ID for their input/output. Up to four different 2541front ends can be connected to a single multiplexed chardev. (Without 2542multiplexing enabled, a chardev can only be used by a single front end.) 2543For instance you could use this to allow a single stdio chardev to be used by 2544two serial ports and the QEMU monitor: 2545 2546@example 2547-chardev stdio,mux=on,id=char0 \ 2548-mon chardev=char0,mode=readline \ 2549-serial chardev:char0 \ 2550-serial chardev:char0 2551@end example 2552 2553You can have more than one multiplexer in a system configuration; for instance 2554you could have a TCP port multiplexed between UART 0 and UART 1, and stdio 2555multiplexed between the QEMU monitor and a parallel port: 2556 2557@example 2558-chardev stdio,mux=on,id=char0 \ 2559-mon chardev=char0,mode=readline \ 2560-parallel chardev:char0 \ 2561-chardev tcp,...,mux=on,id=char1 \ 2562-serial chardev:char1 \ 2563-serial chardev:char1 2564@end example 2565 2566When you're using a multiplexed character device, some escape sequences are 2567interpreted in the input. @xref{mux_keys, Keys in the character backend 2568multiplexer}. 2569 2570Note that some other command line options may implicitly create multiplexed 2571character backends; for instance @option{-serial mon:stdio} creates a 2572multiplexed stdio backend connected to the serial port and the QEMU monitor, 2573and @option{-nographic} also multiplexes the console and the monitor to 2574stdio. 2575 2576There is currently no support for multiplexing in the other direction 2577(where a single QEMU front end takes input and output from multiple chardevs). 2578 2579Every backend supports the @option{logfile} option, which supplies the path 2580to a file to record all data transmitted via the backend. The @option{logappend} 2581option controls whether the log file will be truncated or appended to when 2582opened. 2583 2584Further options to each backend are described below. 2585 2586@item -chardev null ,id=@var{id} 2587A void device. This device will not emit any data, and will drop any data it 2588receives. The null backend does not take any options. 2589 2590@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}] 2591 2592Create a two-way stream socket, which can be either a TCP or a unix socket. A 2593unix socket will be created if @option{path} is specified. Behaviour is 2594undefined if TCP options are specified for a unix socket. 2595 2596@option{server} specifies that the socket shall be a listening socket. 2597 2598@option{nowait} specifies that QEMU should not block waiting for a client to 2599connect to a listening socket. 2600 2601@option{telnet} specifies that traffic on the socket should interpret telnet 2602escape sequences. 2603 2604@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2605the remote end goes away. qemu will delay this many seconds and then attempt 2606to reconnect. Zero disables reconnecting, and is the default. 2607 2608@option{tls-creds} requests enablement of the TLS protocol for encryption, 2609and specifies the id of the TLS credentials to use for the handshake. The 2610credentials must be previously created with the @option{-object tls-creds} 2611argument. 2612 2613TCP and unix socket options are given below: 2614 2615@table @option 2616 2617@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay] 2618 2619@option{host} for a listening socket specifies the local address to be bound. 2620For a connecting socket species the remote host to connect to. @option{host} is 2621optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2622 2623@option{port} for a listening socket specifies the local port to be bound. For a 2624connecting socket specifies the port on the remote host to connect to. 2625@option{port} can be given as either a port number or a service name. 2626@option{port} is required. 2627 2628@option{to} is only relevant to listening sockets. If it is specified, and 2629@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2630to and including @option{to} until it succeeds. @option{to} must be specified 2631as a port number. 2632 2633@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2634If neither is specified the socket may use either protocol. 2635 2636@option{nodelay} disables the Nagle algorithm. 2637 2638@item unix options: path=@var{path} 2639 2640@option{path} specifies the local path of the unix socket. @option{path} is 2641required. 2642 2643@end table 2644 2645@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6] 2646 2647Sends all traffic from the guest to a remote host over UDP. 2648 2649@option{host} specifies the remote host to connect to. If not specified it 2650defaults to @code{localhost}. 2651 2652@option{port} specifies the port on the remote host to connect to. @option{port} 2653is required. 2654 2655@option{localaddr} specifies the local address to bind to. If not specified it 2656defaults to @code{0.0.0.0}. 2657 2658@option{localport} specifies the local port to bind to. If not specified any 2659available local port will be used. 2660 2661@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2662If neither is specified the device may use either protocol. 2663 2664@item -chardev msmouse ,id=@var{id} 2665 2666Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2667take any options. 2668 2669@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]] 2670 2671Connect to a QEMU text console. @option{vc} may optionally be given a specific 2672size. 2673 2674@option{width} and @option{height} specify the width and height respectively of 2675the console, in pixels. 2676 2677@option{cols} and @option{rows} specify that the console be sized to fit a text 2678console with the given dimensions. 2679 2680@item -chardev ringbuf ,id=@var{id} [,size=@var{size}] 2681 2682Create a ring buffer with fixed size @option{size}. 2683@var{size} must be a power of two and defaults to @code{64K}. 2684 2685@item -chardev file ,id=@var{id} ,path=@var{path} 2686 2687Log all traffic received from the guest to a file. 2688 2689@option{path} specifies the path of the file to be opened. This file will be 2690created if it does not already exist, and overwritten if it does. @option{path} 2691is required. 2692 2693@item -chardev pipe ,id=@var{id} ,path=@var{path} 2694 2695Create a two-way connection to the guest. The behaviour differs slightly between 2696Windows hosts and other hosts: 2697 2698On Windows, a single duplex pipe will be created at 2699@file{\\.pipe\@option{path}}. 2700 2701On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2702@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2703received by the guest. Data written by the guest can be read from 2704@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2705be present. 2706 2707@option{path} forms part of the pipe path as described above. @option{path} is 2708required. 2709 2710@item -chardev console ,id=@var{id} 2711 2712Send traffic from the guest to QEMU's standard output. @option{console} does not 2713take any options. 2714 2715@option{console} is only available on Windows hosts. 2716 2717@item -chardev serial ,id=@var{id} ,path=@option{path} 2718 2719Send traffic from the guest to a serial device on the host. 2720 2721On Unix hosts serial will actually accept any tty device, 2722not only serial lines. 2723 2724@option{path} specifies the name of the serial device to open. 2725 2726@item -chardev pty ,id=@var{id} 2727 2728Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2729not take any options. 2730 2731@option{pty} is not available on Windows hosts. 2732 2733@item -chardev stdio ,id=@var{id} [,signal=on|off] 2734Connect to standard input and standard output of the QEMU process. 2735 2736@option{signal} controls if signals are enabled on the terminal, that includes 2737exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2738default, use @option{signal=off} to disable it. 2739 2740@item -chardev braille ,id=@var{id} 2741 2742Connect to a local BrlAPI server. @option{braille} does not take any options. 2743 2744@item -chardev tty ,id=@var{id} ,path=@var{path} 2745 2746@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2747DragonFlyBSD hosts. It is an alias for @option{serial}. 2748 2749@option{path} specifies the path to the tty. @option{path} is required. 2750 2751@item -chardev parallel ,id=@var{id} ,path=@var{path} 2752@itemx -chardev parport ,id=@var{id} ,path=@var{path} 2753 2754@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2755 2756Connect to a local parallel port. 2757 2758@option{path} specifies the path to the parallel port device. @option{path} is 2759required. 2760 2761@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2762 2763@option{spicevmc} is only available when spice support is built in. 2764 2765@option{debug} debug level for spicevmc 2766 2767@option{name} name of spice channel to connect to 2768 2769Connect to a spice virtual machine channel, such as vdiport. 2770 2771@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2772 2773@option{spiceport} is only available when spice support is built in. 2774 2775@option{debug} debug level for spicevmc 2776 2777@option{name} name of spice port to connect to 2778 2779Connect to a spice port, allowing a Spice client to handle the traffic 2780identified by a name (preferably a fqdn). 2781ETEXI 2782 2783STEXI 2784@end table 2785ETEXI 2786DEFHEADING() 2787 2788DEFHEADING(Device URL Syntax) 2789STEXI 2790 2791In addition to using normal file images for the emulated storage devices, 2792QEMU can also use networked resources such as iSCSI devices. These are 2793specified using a special URL syntax. 2794 2795@table @option 2796@item iSCSI 2797iSCSI support allows QEMU to access iSCSI resources directly and use as 2798images for the guest storage. Both disk and cdrom images are supported. 2799 2800Syntax for specifying iSCSI LUNs is 2801``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>'' 2802 2803By default qemu will use the iSCSI initiator-name 2804'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command 2805line or a configuration file. 2806 2807Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect 2808stalled requests and force a reestablishment of the session. The timeout 2809is specified in seconds. The default is 0 which means no timeout. Libiscsi 28101.15.0 or greater is required for this feature. 2811 2812Example (without authentication): 2813@example 2814qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \ 2815 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \ 2816 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2817@end example 2818 2819Example (CHAP username/password via URL): 2820@example 2821qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1 2822@end example 2823 2824Example (CHAP username/password via environment variables): 2825@example 2826LIBISCSI_CHAP_USERNAME="user" \ 2827LIBISCSI_CHAP_PASSWORD="password" \ 2828qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2829@end example 2830 2831iSCSI support is an optional feature of QEMU and only available when 2832compiled and linked against libiscsi. 2833ETEXI 2834DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 2835 "-iscsi [user=user][,password=password]\n" 2836 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 2837 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2838 " [,timeout=timeout]\n" 2839 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2840STEXI 2841 2842iSCSI parameters such as username and password can also be specified via 2843a configuration file. See qemu-doc for more information and examples. 2844 2845@item NBD 2846QEMU supports NBD (Network Block Devices) both using TCP protocol as well 2847as Unix Domain Sockets. 2848 2849Syntax for specifying a NBD device using TCP 2850``nbd:<server-ip>:<port>[:exportname=<export>]'' 2851 2852Syntax for specifying a NBD device using Unix Domain Sockets 2853``nbd:unix:<domain-socket>[:exportname=<export>]'' 2854 2855 2856Example for TCP 2857@example 2858qemu-system-i386 --drive file=nbd:192.0.2.1:30000 2859@end example 2860 2861Example for Unix Domain Sockets 2862@example 2863qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket 2864@end example 2865 2866@item SSH 2867QEMU supports SSH (Secure Shell) access to remote disks. 2868 2869Examples: 2870@example 2871qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img 2872qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img 2873@end example 2874 2875Currently authentication must be done using ssh-agent. Other 2876authentication methods may be supported in future. 2877 2878@item Sheepdog 2879Sheepdog is a distributed storage system for QEMU. 2880QEMU supports using either local sheepdog devices or remote networked 2881devices. 2882 2883Syntax for specifying a sheepdog device 2884@example 2885sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag] 2886@end example 2887 2888Example 2889@example 2890qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine 2891@end example 2892 2893See also @url{https://sheepdog.github.io/sheepdog/}. 2894 2895@item GlusterFS 2896GlusterFS is a user space distributed file system. 2897QEMU supports the use of GlusterFS volumes for hosting VM disk images using 2898TCP, Unix Domain Sockets and RDMA transport protocols. 2899 2900Syntax for specifying a VM disk image on GlusterFS volume is 2901@example 2902 2903URI: 2904gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...] 2905 2906JSON: 2907'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...", 2908@ "server":[@{"type":"tcp","host":"...","port":"..."@}, 2909@ @{"type":"unix","socket":"..."@}]@}@}' 2910@end example 2911 2912 2913Example 2914@example 2915URI: 2916qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img, 2917@ file.debug=9,file.logfile=/var/log/qemu-gluster.log 2918 2919JSON: 2920qemu-system-x86_64 'json:@{"driver":"qcow2", 2921@ "file":@{"driver":"gluster", 2922@ "volume":"testvol","path":"a.img", 2923@ "debug":9,"logfile":"/var/log/qemu-gluster.log", 2924@ "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@}, 2925@ @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}' 2926qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img, 2927@ file.debug=9,file.logfile=/var/log/qemu-gluster.log, 2928@ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007, 2929@ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket 2930@end example 2931 2932See also @url{http://www.gluster.org}. 2933 2934@item HTTP/HTTPS/FTP/FTPS 2935QEMU supports read-only access to files accessed over http(s) and ftp(s). 2936 2937Syntax using a single filename: 2938@example 2939<protocol>://[<username>[:<password>]@@]<host>/<path> 2940@end example 2941 2942where: 2943@table @option 2944@item protocol 2945'http', 'https', 'ftp', or 'ftps'. 2946 2947@item username 2948Optional username for authentication to the remote server. 2949 2950@item password 2951Optional password for authentication to the remote server. 2952 2953@item host 2954Address of the remote server. 2955 2956@item path 2957Path on the remote server, including any query string. 2958@end table 2959 2960The following options are also supported: 2961@table @option 2962@item url 2963The full URL when passing options to the driver explicitly. 2964 2965@item readahead 2966The amount of data to read ahead with each range request to the remote server. 2967This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it 2968does not have a suffix, it will be assumed to be in bytes. The value must be a 2969multiple of 512 bytes. It defaults to 256k. 2970 2971@item sslverify 2972Whether to verify the remote server's certificate when connecting over SSL. It 2973can have the value 'on' or 'off'. It defaults to 'on'. 2974 2975@item cookie 2976Send this cookie (it can also be a list of cookies separated by ';') with 2977each outgoing request. Only supported when using protocols such as HTTP 2978which support cookies, otherwise ignored. 2979 2980@item timeout 2981Set the timeout in seconds of the CURL connection. This timeout is the time 2982that CURL waits for a response from the remote server to get the size of the 2983image to be downloaded. If not set, the default timeout of 5 seconds is used. 2984@end table 2985 2986Note that when passing options to qemu explicitly, @option{driver} is the value 2987of <protocol>. 2988 2989Example: boot from a remote Fedora 20 live ISO image 2990@example 2991qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly 2992 2993qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly 2994@end example 2995 2996Example: boot from a remote Fedora 20 cloud image using a local overlay for 2997writes, copy-on-read, and a readahead of 64k 2998@example 2999qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2 3000 3001qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on 3002@end example 3003 3004Example: boot from an image stored on a VMware vSphere server with a self-signed 3005certificate using a local overlay for writes, a readahead of 64k and a timeout 3006of 10 seconds. 3007@example 3008qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2 3009 3010qemu-system-x86_64 -drive file=/tmp/test.qcow2 3011@end example 3012ETEXI 3013 3014STEXI 3015@end table 3016ETEXI 3017 3018DEFHEADING(Bluetooth(R) options) 3019STEXI 3020@table @option 3021ETEXI 3022 3023DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 3024 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 3025 "-bt hci,host[:id]\n" \ 3026 " use host's HCI with the given name\n" \ 3027 "-bt hci[,vlan=n]\n" \ 3028 " emulate a standard HCI in virtual scatternet 'n'\n" \ 3029 "-bt vhci[,vlan=n]\n" \ 3030 " add host computer to virtual scatternet 'n' using VHCI\n" \ 3031 "-bt device:dev[,vlan=n]\n" \ 3032 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 3033 QEMU_ARCH_ALL) 3034STEXI 3035@item -bt hci[...] 3036@findex -bt 3037Defines the function of the corresponding Bluetooth HCI. -bt options 3038are matched with the HCIs present in the chosen machine type. For 3039example when emulating a machine with only one HCI built into it, only 3040the first @code{-bt hci[...]} option is valid and defines the HCI's 3041logic. The Transport Layer is decided by the machine type. Currently 3042the machines @code{n800} and @code{n810} have one HCI and all other 3043machines have none. 3044 3045@anchor{bt-hcis} 3046The following three types are recognized: 3047 3048@table @option 3049@item -bt hci,null 3050(default) The corresponding Bluetooth HCI assumes no internal logic 3051and will not respond to any HCI commands or emit events. 3052 3053@item -bt hci,host[:@var{id}] 3054(@code{bluez} only) The corresponding HCI passes commands / events 3055to / from the physical HCI identified by the name @var{id} (default: 3056@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 3057capable systems like Linux. 3058 3059@item -bt hci[,vlan=@var{n}] 3060Add a virtual, standard HCI that will participate in the Bluetooth 3061scatternet @var{n} (default @code{0}). Similarly to @option{-net} 3062VLANs, devices inside a bluetooth network @var{n} can only communicate 3063with other devices in the same network (scatternet). 3064@end table 3065 3066@item -bt vhci[,vlan=@var{n}] 3067(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 3068to the host bluetooth stack instead of to the emulated target. This 3069allows the host and target machines to participate in a common scatternet 3070and communicate. Requires the Linux @code{vhci} driver installed. Can 3071be used as following: 3072 3073@example 3074qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 3075@end example 3076 3077@item -bt device:@var{dev}[,vlan=@var{n}] 3078Emulate a bluetooth device @var{dev} and place it in network @var{n} 3079(default @code{0}). QEMU can only emulate one type of bluetooth devices 3080currently: 3081 3082@table @option 3083@item keyboard 3084Virtual wireless keyboard implementing the HIDP bluetooth profile. 3085@end table 3086ETEXI 3087 3088STEXI 3089@end table 3090ETEXI 3091DEFHEADING() 3092 3093#ifdef CONFIG_TPM 3094DEFHEADING(TPM device options) 3095 3096DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 3097 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 3098 " use path to provide path to a character device; default is /dev/tpm0\n" 3099 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 3100 " not provided it will be searched for in /sys/class/misc/tpm?/device\n", 3101 QEMU_ARCH_ALL) 3102STEXI 3103 3104The general form of a TPM device option is: 3105@table @option 3106 3107@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] 3108@findex -tpmdev 3109Backend type must be: 3110@option{passthrough}. 3111 3112The specific backend type will determine the applicable options. 3113The @code{-tpmdev} option creates the TPM backend and requires a 3114@code{-device} option that specifies the TPM frontend interface model. 3115 3116Options to each backend are described below. 3117 3118Use 'help' to print all available TPM backend types. 3119@example 3120qemu -tpmdev help 3121@end example 3122 3123@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path} 3124 3125(Linux-host only) Enable access to the host's TPM using the passthrough 3126driver. 3127 3128@option{path} specifies the path to the host's TPM device, i.e., on 3129a Linux host this would be @code{/dev/tpm0}. 3130@option{path} is optional and by default @code{/dev/tpm0} is used. 3131 3132@option{cancel-path} specifies the path to the host TPM device's sysfs 3133entry allowing for cancellation of an ongoing TPM command. 3134@option{cancel-path} is optional and by default QEMU will search for the 3135sysfs entry to use. 3136 3137Some notes about using the host's TPM with the passthrough driver: 3138 3139The TPM device accessed by the passthrough driver must not be 3140used by any other application on the host. 3141 3142Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 3143the VM's firmware (BIOS/UEFI) will not be able to initialize the 3144TPM again and may therefore not show a TPM-specific menu that would 3145otherwise allow the user to configure the TPM, e.g., allow the user to 3146enable/disable or activate/deactivate the TPM. 3147Further, if TPM ownership is released from within a VM then the host's TPM 3148will get disabled and deactivated. To enable and activate the 3149TPM again afterwards, the host has to be rebooted and the user is 3150required to enter the firmware's menu to enable and activate the TPM. 3151If the TPM is left disabled and/or deactivated most TPM commands will fail. 3152 3153To create a passthrough TPM use the following two options: 3154@example 3155-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 3156@end example 3157Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 3158@code{tpmdev=tpm0} in the device option. 3159 3160@end table 3161 3162ETEXI 3163 3164DEFHEADING() 3165 3166#endif 3167 3168DEFHEADING(Linux/Multiboot boot specific) 3169STEXI 3170 3171When using these options, you can use a given Linux or Multiboot 3172kernel without installing it in the disk image. It can be useful 3173for easier testing of various kernels. 3174 3175@table @option 3176ETEXI 3177 3178DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 3179 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 3180STEXI 3181@item -kernel @var{bzImage} 3182@findex -kernel 3183Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 3184or in multiboot format. 3185ETEXI 3186 3187DEF("append", HAS_ARG, QEMU_OPTION_append, \ 3188 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 3189STEXI 3190@item -append @var{cmdline} 3191@findex -append 3192Use @var{cmdline} as kernel command line 3193ETEXI 3194 3195DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 3196 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 3197STEXI 3198@item -initrd @var{file} 3199@findex -initrd 3200Use @var{file} as initial ram disk. 3201 3202@item -initrd "@var{file1} arg=foo,@var{file2}" 3203 3204This syntax is only available with multiboot. 3205 3206Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 3207first module. 3208ETEXI 3209 3210DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 3211 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 3212STEXI 3213@item -dtb @var{file} 3214@findex -dtb 3215Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 3216on boot. 3217ETEXI 3218 3219STEXI 3220@end table 3221ETEXI 3222DEFHEADING() 3223 3224DEFHEADING(Debug/Expert options) 3225STEXI 3226@table @option 3227ETEXI 3228 3229DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 3230 "-fw_cfg [name=]<name>,file=<file>\n" 3231 " add named fw_cfg entry with contents from file\n" 3232 "-fw_cfg [name=]<name>,string=<str>\n" 3233 " add named fw_cfg entry with contents from string\n", 3234 QEMU_ARCH_ALL) 3235STEXI 3236 3237@item -fw_cfg [name=]@var{name},file=@var{file} 3238@findex -fw_cfg 3239Add named fw_cfg entry with contents from file @var{file}. 3240 3241@item -fw_cfg [name=]@var{name},string=@var{str} 3242Add named fw_cfg entry with contents from string @var{str}. 3243 3244The terminating NUL character of the contents of @var{str} will not be 3245included as part of the fw_cfg item data. To insert contents with 3246embedded NUL characters, you have to use the @var{file} parameter. 3247 3248The fw_cfg entries are passed by QEMU through to the guest. 3249 3250Example: 3251@example 3252 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin 3253@end example 3254creates an fw_cfg entry named opt/com.mycompany/blob with contents 3255from ./my_blob.bin. 3256 3257ETEXI 3258 3259DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 3260 "-serial dev redirect the serial port to char device 'dev'\n", 3261 QEMU_ARCH_ALL) 3262STEXI 3263@item -serial @var{dev} 3264@findex -serial 3265Redirect the virtual serial port to host character device 3266@var{dev}. The default device is @code{vc} in graphical mode and 3267@code{stdio} in non graphical mode. 3268 3269This option can be used several times to simulate up to 4 serial 3270ports. 3271 3272Use @code{-serial none} to disable all serial ports. 3273 3274Available character devices are: 3275@table @option 3276@item vc[:@var{W}x@var{H}] 3277Virtual console. Optionally, a width and height can be given in pixel with 3278@example 3279vc:800x600 3280@end example 3281It is also possible to specify width or height in characters: 3282@example 3283vc:80Cx24C 3284@end example 3285@item pty 3286[Linux only] Pseudo TTY (a new PTY is automatically allocated) 3287@item none 3288No device is allocated. 3289@item null 3290void device 3291@item chardev:@var{id} 3292Use a named character device defined with the @code{-chardev} option. 3293@item /dev/XXX 3294[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 3295parameters are set according to the emulated ones. 3296@item /dev/parport@var{N} 3297[Linux only, parallel port only] Use host parallel port 3298@var{N}. Currently SPP and EPP parallel port features can be used. 3299@item file:@var{filename} 3300Write output to @var{filename}. No character can be read. 3301@item stdio 3302[Unix only] standard input/output 3303@item pipe:@var{filename} 3304name pipe @var{filename} 3305@item COM@var{n} 3306[Windows only] Use host serial port @var{n} 3307@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 3308This implements UDP Net Console. 3309When @var{remote_host} or @var{src_ip} are not specified 3310they default to @code{0.0.0.0}. 3311When not using a specified @var{src_port} a random port is automatically chosen. 3312 3313If you just want a simple readonly console you can use @code{netcat} or 3314@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 3315@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 3316will appear in the netconsole session. 3317 3318If you plan to send characters back via netconsole or you want to stop 3319and start QEMU a lot of times, you should have QEMU use the same 3320source port each time by using something like @code{-serial 3321udp::4555@@:4556} to QEMU. Another approach is to use a patched 3322version of netcat which can listen to a TCP port and send and receive 3323characters via udp. If you have a patched version of netcat which 3324activates telnet remote echo and single char transfer, then you can 3325use the following options to set up a netcat redirector to allow 3326telnet on port 5555 to access the QEMU port. 3327@table @code 3328@item QEMU Options: 3329-serial udp::4555@@:4556 3330@item netcat options: 3331-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 3332@item telnet options: 3333localhost 5555 3334@end table 3335 3336@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 3337The TCP Net Console has two modes of operation. It can send the serial 3338I/O to a location or wait for a connection from a location. By default 3339the TCP Net Console is sent to @var{host} at the @var{port}. If you use 3340the @var{server} option QEMU will wait for a client socket application 3341to connect to the port before continuing, unless the @code{nowait} 3342option was specified. The @code{nodelay} option disables the Nagle buffering 3343algorithm. The @code{reconnect} option only applies if @var{noserver} is 3344set, if the connection goes down it will attempt to reconnect at the 3345given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 3346one TCP connection at a time is accepted. You can use @code{telnet} to 3347connect to the corresponding character device. 3348@table @code 3349@item Example to send tcp console to 192.168.0.2 port 4444 3350-serial tcp:192.168.0.2:4444 3351@item Example to listen and wait on port 4444 for connection 3352-serial tcp::4444,server 3353@item Example to not wait and listen on ip 192.168.0.100 port 4444 3354-serial tcp:192.168.0.100:4444,server,nowait 3355@end table 3356 3357@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 3358The telnet protocol is used instead of raw tcp sockets. The options 3359work the same as if you had specified @code{-serial tcp}. The 3360difference is that the port acts like a telnet server or client using 3361telnet option negotiation. This will also allow you to send the 3362MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 3363sequence. Typically in unix telnet you do it with Control-] and then 3364type "send break" followed by pressing the enter key. 3365 3366@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 3367A unix domain socket is used instead of a tcp socket. The option works the 3368same as if you had specified @code{-serial tcp} except the unix domain socket 3369@var{path} is used for connections. 3370 3371@item mon:@var{dev_string} 3372This is a special option to allow the monitor to be multiplexed onto 3373another serial port. The monitor is accessed with key sequence of 3374@key{Control-a} and then pressing @key{c}. 3375@var{dev_string} should be any one of the serial devices specified 3376above. An example to multiplex the monitor onto a telnet server 3377listening on port 4444 would be: 3378@table @code 3379@item -serial mon:telnet::4444,server,nowait 3380@end table 3381When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 3382QEMU any more but will be passed to the guest instead. 3383 3384@item braille 3385Braille device. This will use BrlAPI to display the braille output on a real 3386or fake device. 3387 3388@item msmouse 3389Three button serial mouse. Configure the guest to use Microsoft protocol. 3390@end table 3391ETEXI 3392 3393DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 3394 "-parallel dev redirect the parallel port to char device 'dev'\n", 3395 QEMU_ARCH_ALL) 3396STEXI 3397@item -parallel @var{dev} 3398@findex -parallel 3399Redirect the virtual parallel port to host device @var{dev} (same 3400devices as the serial port). On Linux hosts, @file{/dev/parportN} can 3401be used to use hardware devices connected on the corresponding host 3402parallel port. 3403 3404This option can be used several times to simulate up to 3 parallel 3405ports. 3406 3407Use @code{-parallel none} to disable all parallel ports. 3408ETEXI 3409 3410DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 3411 "-monitor dev redirect the monitor to char device 'dev'\n", 3412 QEMU_ARCH_ALL) 3413STEXI 3414@item -monitor @var{dev} 3415@findex -monitor 3416Redirect the monitor to host device @var{dev} (same devices as the 3417serial port). 3418The default device is @code{vc} in graphical mode and @code{stdio} in 3419non graphical mode. 3420Use @code{-monitor none} to disable the default monitor. 3421ETEXI 3422DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 3423 "-qmp dev like -monitor but opens in 'control' mode\n", 3424 QEMU_ARCH_ALL) 3425STEXI 3426@item -qmp @var{dev} 3427@findex -qmp 3428Like -monitor but opens in 'control' mode. 3429ETEXI 3430DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 3431 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 3432 QEMU_ARCH_ALL) 3433STEXI 3434@item -qmp-pretty @var{dev} 3435@findex -qmp-pretty 3436Like -qmp but uses pretty JSON formatting. 3437ETEXI 3438 3439DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 3440 "-mon [chardev=]name[,mode=readline|control]\n", QEMU_ARCH_ALL) 3441STEXI 3442@item -mon [chardev=]name[,mode=readline|control] 3443@findex -mon 3444Setup monitor on chardev @var{name}. 3445ETEXI 3446 3447DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 3448 "-debugcon dev redirect the debug console to char device 'dev'\n", 3449 QEMU_ARCH_ALL) 3450STEXI 3451@item -debugcon @var{dev} 3452@findex -debugcon 3453Redirect the debug console to host device @var{dev} (same devices as the 3454serial port). The debug console is an I/O port which is typically port 34550xe9; writing to that I/O port sends output to this device. 3456The default device is @code{vc} in graphical mode and @code{stdio} in 3457non graphical mode. 3458ETEXI 3459 3460DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 3461 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 3462STEXI 3463@item -pidfile @var{file} 3464@findex -pidfile 3465Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 3466from a script. 3467ETEXI 3468 3469DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 3470 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 3471STEXI 3472@item -singlestep 3473@findex -singlestep 3474Run the emulation in single step mode. 3475ETEXI 3476 3477DEF("S", 0, QEMU_OPTION_S, \ 3478 "-S freeze CPU at startup (use 'c' to start execution)\n", 3479 QEMU_ARCH_ALL) 3480STEXI 3481@item -S 3482@findex -S 3483Do not start CPU at startup (you must type 'c' in the monitor). 3484ETEXI 3485 3486DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 3487 "-realtime [mlock=on|off]\n" 3488 " run qemu with realtime features\n" 3489 " mlock=on|off controls mlock support (default: on)\n", 3490 QEMU_ARCH_ALL) 3491STEXI 3492@item -realtime mlock=on|off 3493@findex -realtime 3494Run qemu with realtime features. 3495mlocking qemu and guest memory can be enabled via @option{mlock=on} 3496(enabled by default). 3497ETEXI 3498 3499DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 3500 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 3501STEXI 3502@item -gdb @var{dev} 3503@findex -gdb 3504Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 3505connections will likely be TCP-based, but also UDP, pseudo TTY, or even 3506stdio are reasonable use case. The latter is allowing to start QEMU from 3507within gdb and establish the connection via a pipe: 3508@example 3509(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 3510@end example 3511ETEXI 3512 3513DEF("s", 0, QEMU_OPTION_s, \ 3514 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 3515 QEMU_ARCH_ALL) 3516STEXI 3517@item -s 3518@findex -s 3519Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3520(@pxref{gdb_usage}). 3521ETEXI 3522 3523DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3524 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3525 QEMU_ARCH_ALL) 3526STEXI 3527@item -d @var{item1}[,...] 3528@findex -d 3529Enable logging of specified items. Use '-d help' for a list of log items. 3530ETEXI 3531 3532DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3533 "-D logfile output log to logfile (default stderr)\n", 3534 QEMU_ARCH_ALL) 3535STEXI 3536@item -D @var{logfile} 3537@findex -D 3538Output log in @var{logfile} instead of to stderr 3539ETEXI 3540 3541DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \ 3542 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n", 3543 QEMU_ARCH_ALL) 3544STEXI 3545@item -dfilter @var{range1}[,...] 3546@findex -dfilter 3547Filter debug output to that relevant to a range of target addresses. The filter 3548spec can be either @var{start}+@var{size}, @var{start}-@var{size} or 3549@var{start}..@var{end} where @var{start} @var{end} and @var{size} are the 3550addresses and sizes required. For example: 3551@example 3552 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000 3553@end example 3554Will dump output for any code in the 0x1000 sized block starting at 0x8000 and 3555the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized 3556block starting at 0xffffffc00005f000. 3557ETEXI 3558 3559DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3560 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3561 QEMU_ARCH_ALL) 3562STEXI 3563@item -L @var{path} 3564@findex -L 3565Set the directory for the BIOS, VGA BIOS and keymaps. 3566 3567To list all the data directories, use @code{-L help}. 3568ETEXI 3569 3570DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3571 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3572STEXI 3573@item -bios @var{file} 3574@findex -bios 3575Set the filename for the BIOS. 3576ETEXI 3577 3578DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3579 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3580STEXI 3581@item -enable-kvm 3582@findex -enable-kvm 3583Enable KVM full virtualization support. This option is only available 3584if KVM support is enabled when compiling. 3585ETEXI 3586 3587DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \ 3588 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386) 3589STEXI 3590@item -enable-hax 3591@findex -enable-hax 3592Enable HAX (Hardware-based Acceleration eXecution) support. This option 3593is only available if HAX support is enabled when compiling. HAX is only 3594applicable to MAC and Windows platform, and thus does not conflict with 3595KVM. 3596ETEXI 3597 3598DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3599 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3600DEF("xen-create", 0, QEMU_OPTION_xen_create, 3601 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3602 " warning: should not be used when xend is in use\n", 3603 QEMU_ARCH_ALL) 3604DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3605 "-xen-attach attach to existing xen domain\n" 3606 " xend will use this when starting QEMU\n", 3607 QEMU_ARCH_ALL) 3608DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict, 3609 "-xen-domid-restrict restrict set of available xen operations\n" 3610 " to specified domain id. (Does not affect\n" 3611 " xenpv machine type).\n", 3612 QEMU_ARCH_ALL) 3613STEXI 3614@item -xen-domid @var{id} 3615@findex -xen-domid 3616Specify xen guest domain @var{id} (XEN only). 3617@item -xen-create 3618@findex -xen-create 3619Create domain using xen hypercalls, bypassing xend. 3620Warning: should not be used when xend is in use (XEN only). 3621@item -xen-attach 3622@findex -xen-attach 3623Attach to existing xen domain. 3624xend will use this when starting QEMU (XEN only). 3625@findex -xen-domid-restrict 3626Restrict set of available xen operations to specified domain id (XEN only). 3627ETEXI 3628 3629DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3630 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3631STEXI 3632@item -no-reboot 3633@findex -no-reboot 3634Exit instead of rebooting. 3635ETEXI 3636 3637DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3638 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3639STEXI 3640@item -no-shutdown 3641@findex -no-shutdown 3642Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3643This allows for instance switching to monitor to commit changes to the 3644disk image. 3645ETEXI 3646 3647DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3648 "-loadvm [tag|id]\n" \ 3649 " start right away with a saved state (loadvm in monitor)\n", 3650 QEMU_ARCH_ALL) 3651STEXI 3652@item -loadvm @var{file} 3653@findex -loadvm 3654Start right away with a saved state (@code{loadvm} in monitor) 3655ETEXI 3656 3657#ifndef _WIN32 3658DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3659 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3660#endif 3661STEXI 3662@item -daemonize 3663@findex -daemonize 3664Daemonize the QEMU process after initialization. QEMU will not detach from 3665standard IO until it is ready to receive connections on any of its devices. 3666This option is a useful way for external programs to launch QEMU without having 3667to cope with initialization race conditions. 3668ETEXI 3669 3670DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3671 "-option-rom rom load a file, rom, into the option ROM space\n", 3672 QEMU_ARCH_ALL) 3673STEXI 3674@item -option-rom @var{file} 3675@findex -option-rom 3676Load the contents of @var{file} as an option ROM. 3677This option is useful to load things like EtherBoot. 3678ETEXI 3679 3680HXCOMM Silently ignored for compatibility 3681DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3682 3683HXCOMM Options deprecated by -rtc 3684DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3685DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3686 3687DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3688 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3689 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3690 QEMU_ARCH_ALL) 3691 3692STEXI 3693 3694@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3695@findex -rtc 3696Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3697UTC or local time, respectively. @code{localtime} is required for correct date in 3698MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3699format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3700 3701By default the RTC is driven by the host system time. This allows using of the 3702RTC as accurate reference clock inside the guest, specifically if the host 3703time is smoothly following an accurate external reference clock, e.g. via NTP. 3704If you want to isolate the guest time from the host, you can set @option{clock} 3705to @code{rt} instead. To even prevent it from progressing during suspension, 3706you can set it to @code{vm}. 3707 3708Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3709specifically with Windows' ACPI HAL. This option will try to figure out how 3710many timer interrupts were not processed by the Windows guest and will 3711re-inject them. 3712ETEXI 3713 3714DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3715 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ 3716 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3717 " instruction, enable aligning the host and virtual clocks\n" \ 3718 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3719STEXI 3720@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] 3721@findex -icount 3722Enable virtual instruction counter. The virtual cpu will execute one 3723instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3724then the virtual cpu speed will be automatically adjusted to keep virtual 3725time within a few seconds of real time. 3726 3727When the virtual cpu is sleeping, the virtual time will advance at default 3728speed unless @option{sleep=on|off} is specified. 3729With @option{sleep=on|off}, the virtual time will jump to the next timer deadline 3730instantly whenever the virtual cpu goes to sleep mode and will not advance 3731if no timer is enabled. This behavior give deterministic execution times from 3732the guest point of view. 3733 3734Note that while this option can give deterministic behavior, it does not 3735provide cycle accurate emulation. Modern CPUs contain superscalar out of 3736order cores with complex cache hierarchies. The number of instructions 3737executed often has little or no correlation with actual performance. 3738 3739@option{align=on} will activate the delay algorithm which will try 3740to synchronise the host clock and the virtual clock. The goal is to 3741have a guest running at the real frequency imposed by the shift option. 3742Whenever the guest clock is behind the host clock and if 3743@option{align=on} is specified then we print a message to the user 3744to inform about the delay. 3745Currently this option does not work when @option{shift} is @code{auto}. 3746Note: The sync algorithm will work for those shift values for which 3747the guest clock runs ahead of the host clock. Typically this happens 3748when the shift value is high (how high depends on the host machine). 3749 3750When @option{rr} option is specified deterministic record/replay is enabled. 3751Replay log is written into @var{filename} file in record mode and 3752read from this file in replay mode. 3753 3754Option rrsnapshot is used to create new vm snapshot named @var{snapshot} 3755at the start of execution recording. In replay mode this option is used 3756to load the initial VM state. 3757ETEXI 3758 3759DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3760 "-watchdog model\n" \ 3761 " enable virtual hardware watchdog [default=none]\n", 3762 QEMU_ARCH_ALL) 3763STEXI 3764@item -watchdog @var{model} 3765@findex -watchdog 3766Create a virtual hardware watchdog device. Once enabled (by a guest 3767action), the watchdog must be periodically polled by an agent inside 3768the guest or else the guest will be restarted. Choose a model for 3769which your guest has drivers. 3770 3771The @var{model} is the model of hardware watchdog to emulate. Use 3772@code{-watchdog help} to list available hardware models. Only one 3773watchdog can be enabled for a guest. 3774 3775The following models may be available: 3776@table @option 3777@item ib700 3778iBASE 700 is a very simple ISA watchdog with a single timer. 3779@item i6300esb 3780Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3781dual-timer watchdog. 3782@item diag288 3783A virtual watchdog for s390x backed by the diagnose 288 hypercall 3784(currently KVM only). 3785@end table 3786ETEXI 3787 3788DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3789 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \ 3790 " action when watchdog fires [default=reset]\n", 3791 QEMU_ARCH_ALL) 3792STEXI 3793@item -watchdog-action @var{action} 3794@findex -watchdog-action 3795 3796The @var{action} controls what QEMU will do when the watchdog timer 3797expires. 3798The default is 3799@code{reset} (forcefully reset the guest). 3800Other possible actions are: 3801@code{shutdown} (attempt to gracefully shutdown the guest), 3802@code{poweroff} (forcefully poweroff the guest), 3803@code{pause} (pause the guest), 3804@code{debug} (print a debug message and continue), or 3805@code{none} (do nothing). 3806 3807Note that the @code{shutdown} action requires that the guest responds 3808to ACPI signals, which it may not be able to do in the sort of 3809situations where the watchdog would have expired, and thus 3810@code{-watchdog-action shutdown} is not recommended for production use. 3811 3812Examples: 3813 3814@table @code 3815@item -watchdog i6300esb -watchdog-action pause 3816@itemx -watchdog ib700 3817@end table 3818ETEXI 3819 3820DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3821 "-echr chr set terminal escape character instead of ctrl-a\n", 3822 QEMU_ARCH_ALL) 3823STEXI 3824 3825@item -echr @var{numeric_ascii_value} 3826@findex -echr 3827Change the escape character used for switching to the monitor when using 3828monitor and serial sharing. The default is @code{0x01} when using the 3829@code{-nographic} option. @code{0x01} is equal to pressing 3830@code{Control-a}. You can select a different character from the ascii 3831control keys where 1 through 26 map to Control-a through Control-z. For 3832instance you could use the either of the following to change the escape 3833character to Control-t. 3834@table @code 3835@item -echr 0x14 3836@itemx -echr 20 3837@end table 3838ETEXI 3839 3840DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3841 "-virtioconsole c\n" \ 3842 " set virtio console\n", QEMU_ARCH_ALL) 3843STEXI 3844@item -virtioconsole @var{c} 3845@findex -virtioconsole 3846Set virtio console. 3847 3848This option is maintained for backward compatibility. 3849 3850Please use @code{-device virtconsole} for the new way of invocation. 3851ETEXI 3852 3853DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3854 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3855STEXI 3856@item -show-cursor 3857@findex -show-cursor 3858Show cursor. 3859ETEXI 3860 3861DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3862 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3863STEXI 3864@item -tb-size @var{n} 3865@findex -tb-size 3866Set TB size. 3867ETEXI 3868 3869DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3870 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3871 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3872 "-incoming unix:socketpath\n" \ 3873 " prepare for incoming migration, listen on\n" \ 3874 " specified protocol and socket address\n" \ 3875 "-incoming fd:fd\n" \ 3876 "-incoming exec:cmdline\n" \ 3877 " accept incoming migration on given file descriptor\n" \ 3878 " or from given external command\n" \ 3879 "-incoming defer\n" \ 3880 " wait for the URI to be specified via migrate_incoming\n", 3881 QEMU_ARCH_ALL) 3882STEXI 3883@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3884@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3885@findex -incoming 3886Prepare for incoming migration, listen on a given tcp port. 3887 3888@item -incoming unix:@var{socketpath} 3889Prepare for incoming migration, listen on a given unix socket. 3890 3891@item -incoming fd:@var{fd} 3892Accept incoming migration from a given filedescriptor. 3893 3894@item -incoming exec:@var{cmdline} 3895Accept incoming migration as an output from specified external command. 3896 3897@item -incoming defer 3898Wait for the URI to be specified via migrate_incoming. The monitor can 3899be used to change settings (such as migration parameters) prior to issuing 3900the migrate_incoming to allow the migration to begin. 3901ETEXI 3902 3903DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \ 3904 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL) 3905STEXI 3906@item -only-migratable 3907@findex -only-migratable 3908Only allow migratable devices. Devices will not be allowed to enter an 3909unmigratable state. 3910ETEXI 3911 3912DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3913 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3914STEXI 3915@item -nodefaults 3916@findex -nodefaults 3917Don't create default devices. Normally, QEMU sets the default devices like serial 3918port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3919CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3920default devices. 3921ETEXI 3922 3923#ifndef _WIN32 3924DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3925 "-chroot dir chroot to dir just before starting the VM\n", 3926 QEMU_ARCH_ALL) 3927#endif 3928STEXI 3929@item -chroot @var{dir} 3930@findex -chroot 3931Immediately before starting guest execution, chroot to the specified 3932directory. Especially useful in combination with -runas. 3933ETEXI 3934 3935#ifndef _WIN32 3936DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3937 "-runas user change to user id user just before starting the VM\n", 3938 QEMU_ARCH_ALL) 3939#endif 3940STEXI 3941@item -runas @var{user} 3942@findex -runas 3943Immediately before starting guest execution, drop root privileges, switching 3944to the specified user. 3945ETEXI 3946 3947DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3948 "-prom-env variable=value\n" 3949 " set OpenBIOS nvram variables\n", 3950 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3951STEXI 3952@item -prom-env @var{variable}=@var{value} 3953@findex -prom-env 3954Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3955ETEXI 3956DEF("semihosting", 0, QEMU_OPTION_semihosting, 3957 "-semihosting semihosting mode\n", 3958 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3959 QEMU_ARCH_MIPS) 3960STEXI 3961@item -semihosting 3962@findex -semihosting 3963Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 3964ETEXI 3965DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 3966 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 3967 " semihosting configuration\n", 3968QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3969QEMU_ARCH_MIPS) 3970STEXI 3971@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 3972@findex -semihosting-config 3973Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 3974@table @option 3975@item target=@code{native|gdb|auto} 3976Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 3977or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 3978during debug sessions and @code{native} otherwise. 3979@item arg=@var{str1},arg=@var{str2},... 3980Allows the user to pass input arguments, and can be used multiple times to build 3981up a list. The old-style @code{-kernel}/@code{-append} method of passing a 3982command line is still supported for backward compatibility. If both the 3983@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 3984specified, the former is passed to semihosting as it always takes precedence. 3985@end table 3986ETEXI 3987DEF("old-param", 0, QEMU_OPTION_old_param, 3988 "-old-param old param mode\n", QEMU_ARCH_ARM) 3989STEXI 3990@item -old-param 3991@findex -old-param (ARM) 3992Old param mode (ARM only). 3993ETEXI 3994 3995DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 3996 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", 3997 QEMU_ARCH_ALL) 3998STEXI 3999@item -sandbox @var{arg} 4000@findex -sandbox 4001Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 4002disable it. The default is 'off'. 4003ETEXI 4004 4005DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 4006 "-readconfig <file>\n", QEMU_ARCH_ALL) 4007STEXI 4008@item -readconfig @var{file} 4009@findex -readconfig 4010Read device configuration from @var{file}. This approach is useful when you want to spawn 4011QEMU process with many command line options but you don't want to exceed the command line 4012character limit. 4013ETEXI 4014DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 4015 "-writeconfig <file>\n" 4016 " read/write config file\n", QEMU_ARCH_ALL) 4017STEXI 4018@item -writeconfig @var{file} 4019@findex -writeconfig 4020Write device configuration to @var{file}. The @var{file} can be either filename to save 4021command line and device configuration into file or dash @code{-}) character to print the 4022output to stdout. This can be later used as input file for @code{-readconfig} option. 4023ETEXI 4024DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, 4025 "-nodefconfig\n" 4026 " do not load default config files at startup\n", 4027 QEMU_ARCH_ALL) 4028STEXI 4029@item -nodefconfig 4030@findex -nodefconfig 4031Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup. 4032The @code{-nodefconfig} option will prevent QEMU from loading any of those config files. 4033ETEXI 4034DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 4035 "-no-user-config\n" 4036 " do not load user-provided config files at startup\n", 4037 QEMU_ARCH_ALL) 4038STEXI 4039@item -no-user-config 4040@findex -no-user-config 4041The @code{-no-user-config} option makes QEMU not load any of the user-provided 4042config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config 4043files from @var{datadir}. 4044ETEXI 4045DEF("trace", HAS_ARG, QEMU_OPTION_trace, 4046 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 4047 " specify tracing options\n", 4048 QEMU_ARCH_ALL) 4049STEXI 4050HXCOMM This line is not accurate, as some sub-options are backend-specific but 4051HXCOMM HX does not support conditional compilation of text. 4052@item -trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}] 4053@findex -trace 4054@include qemu-option-trace.texi 4055ETEXI 4056 4057HXCOMM Internal use 4058DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 4059DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 4060 4061#ifdef __linux__ 4062DEF("enable-fips", 0, QEMU_OPTION_enablefips, 4063 "-enable-fips enable FIPS 140-2 compliance\n", 4064 QEMU_ARCH_ALL) 4065#endif 4066STEXI 4067@item -enable-fips 4068@findex -enable-fips 4069Enable FIPS 140-2 compliance mode. 4070ETEXI 4071 4072HXCOMM Deprecated by -machine accel=tcg property 4073DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 4074 4075HXCOMM Deprecated by kvm-pit driver properties 4076DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, 4077 "", QEMU_ARCH_I386) 4078 4079HXCOMM Deprecated (ignored) 4080DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386) 4081 4082HXCOMM Deprecated by -machine kernel_irqchip=on|off property 4083DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386) 4084 4085HXCOMM Deprecated (ignored) 4086DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL) 4087 4088DEF("msg", HAS_ARG, QEMU_OPTION_msg, 4089 "-msg timestamp[=on|off]\n" 4090 " change the format of messages\n" 4091 " on|off controls leading timestamps (default:on)\n", 4092 QEMU_ARCH_ALL) 4093STEXI 4094@item -msg timestamp[=on|off] 4095@findex -msg 4096prepend a timestamp to each log message.(default:on) 4097ETEXI 4098 4099DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 4100 "-dump-vmstate <file>\n" 4101 " Output vmstate information in JSON format to file.\n" 4102 " Use the scripts/vmstate-static-checker.py file to\n" 4103 " check for possible regressions in migration code\n" 4104 " by comparing two such vmstate dumps.\n", 4105 QEMU_ARCH_ALL) 4106STEXI 4107@item -dump-vmstate @var{file} 4108@findex -dump-vmstate 4109Dump json-encoded vmstate information for current machine type to file 4110in @var{file} 4111ETEXI 4112 4113STEXI 4114@end table 4115ETEXI 4116DEFHEADING() 4117DEFHEADING(Generic object creation) 4118STEXI 4119@table @option 4120ETEXI 4121 4122DEF("object", HAS_ARG, QEMU_OPTION_object, 4123 "-object TYPENAME[,PROP1=VALUE1,...]\n" 4124 " create a new object of type TYPENAME setting properties\n" 4125 " in the order they are specified. Note that the 'id'\n" 4126 " property must be set. These objects are placed in the\n" 4127 " '/objects' path.\n", 4128 QEMU_ARCH_ALL) 4129STEXI 4130@item -object @var{typename}[,@var{prop1}=@var{value1},...] 4131@findex -object 4132Create a new object of type @var{typename} setting properties 4133in the order they are specified. Note that the 'id' 4134property must be set. These objects are placed in the 4135'/objects' path. 4136 4137@table @option 4138 4139@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off} 4140 4141Creates a memory file backend object, which can be used to back 4142the guest RAM with huge pages. The @option{id} parameter is a 4143unique ID that will be used to reference this memory region 4144when configuring the @option{-numa} argument. The @option{size} 4145option provides the size of the memory region, and accepts 4146common suffixes, eg @option{500M}. The @option{mem-path} provides 4147the path to either a shared memory or huge page filesystem mount. 4148The @option{share} boolean option determines whether the memory 4149region is marked as private to QEMU, or shared. The latter allows 4150a co-operating external process to access the QEMU memory region. 4151 4152@item -object rng-random,id=@var{id},filename=@var{/dev/random} 4153 4154Creates a random number generator backend which obtains entropy from 4155a device on the host. The @option{id} parameter is a unique ID that 4156will be used to reference this entropy backend from the @option{virtio-rng} 4157device. The @option{filename} parameter specifies which file to obtain 4158entropy from and if omitted defaults to @option{/dev/random}. 4159 4160@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 4161 4162Creates a random number generator backend which obtains entropy from 4163an external daemon running on the host. The @option{id} parameter is 4164a unique ID that will be used to reference this entropy backend from 4165the @option{virtio-rng} device. The @option{chardev} parameter is 4166the unique ID of a character device backend that provides the connection 4167to the RNG daemon. 4168 4169@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 4170 4171Creates a TLS anonymous credentials object, which can be used to provide 4172TLS support on network backends. The @option{id} parameter is a unique 4173ID which network backends will use to access the credentials. The 4174@option{endpoint} is either @option{server} or @option{client} depending 4175on whether the QEMU network backend that uses the credentials will be 4176acting as a client or as a server. If @option{verify-peer} is enabled 4177(the default) then once the handshake is completed, the peer credentials 4178will be verified, though this is a no-op for anonymous credentials. 4179 4180The @var{dir} parameter tells QEMU where to find the credential 4181files. For server endpoints, this directory may contain a file 4182@var{dh-params.pem} providing diffie-hellman parameters to use 4183for the TLS server. If the file is missing, QEMU will generate 4184a set of DH parameters at startup. This is a computationally 4185expensive operation that consumes random pool entropy, so it is 4186recommended that a persistent set of parameters be generated 4187upfront and saved. 4188 4189@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off},passwordid=@var{id} 4190 4191Creates a TLS anonymous credentials object, which can be used to provide 4192TLS support on network backends. The @option{id} parameter is a unique 4193ID which network backends will use to access the credentials. The 4194@option{endpoint} is either @option{server} or @option{client} depending 4195on whether the QEMU network backend that uses the credentials will be 4196acting as a client or as a server. If @option{verify-peer} is enabled 4197(the default) then once the handshake is completed, the peer credentials 4198will be verified. With x509 certificates, this implies that the clients 4199must be provided with valid client certificates too. 4200 4201The @var{dir} parameter tells QEMU where to find the credential 4202files. For server endpoints, this directory may contain a file 4203@var{dh-params.pem} providing diffie-hellman parameters to use 4204for the TLS server. If the file is missing, QEMU will generate 4205a set of DH parameters at startup. This is a computationally 4206expensive operation that consumes random pool entropy, so it is 4207recommended that a persistent set of parameters be generated 4208upfront and saved. 4209 4210For x509 certificate credentials the directory will contain further files 4211providing the x509 certificates. The certificates must be stored 4212in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 4213@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 4214@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 4215 4216For the @var{server-key.pem} and @var{client-key.pem} files which 4217contain sensitive private keys, it is possible to use an encrypted 4218version by providing the @var{passwordid} parameter. This provides 4219the ID of a previously created @code{secret} object containing the 4220password for decryption. 4221 4222@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}] 4223 4224Interval @var{t} can't be 0, this filter batches the packet delivery: all 4225packets arriving in a given interval on netdev @var{netdevid} are delayed 4226until the end of the interval. Interval is in microseconds. 4227@option{status} is optional that indicate whether the netfilter is 4228on (enabled) or off (disabled), the default status for netfilter will be 'on'. 4229 4230queue @var{all|rx|tx} is an option that can be applied to any netfilter. 4231 4232@option{all}: the filter is attached both to the receive and the transmit 4233 queue of the netdev (default). 4234 4235@option{rx}: the filter is attached to the receive queue of the netdev, 4236 where it will receive packets sent to the netdev. 4237 4238@option{tx}: the filter is attached to the transmit queue of the netdev, 4239 where it will receive packets sent by the netdev. 4240 4241@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}] 4242 4243filter-mirror on netdev @var{netdevid},mirror net packet to chardev 4244@var{chardevid} 4245 4246@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid}, 4247outdev=@var{chardevid}[,queue=@var{all|rx|tx}] 4248 4249filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev 4250@var{chardevid},and redirect indev's packet to filter. 4251Create a filter-redirector we need to differ outdev id from indev id, id can not 4252be the same. we can just use indev or outdev, but at least one of indev or outdev 4253need to be specified. 4254 4255@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid}[,queue=@var{all|rx|tx}] 4256 4257Filter-rewriter is a part of COLO project.It will rewrite tcp packet to 4258secondary from primary to keep secondary tcp connection,and rewrite 4259tcp packet to primary from secondary make tcp packet can be handled by 4260client. 4261 4262usage: 4263colo secondary: 4264-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4265-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4266-object filter-rewriter,id=rew0,netdev=hn0,queue=all 4267 4268@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}] 4269 4270Dump the network traffic on netdev @var{dev} to the file specified by 4271@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 4272The file format is libpcap, so it can be analyzed with tools such as tcpdump 4273or Wireshark. 4274 4275@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid}, 4276outdev=@var{chardevid} 4277 4278Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with 4279secondary packet. If the packets are same, we will output primary 4280packet to outdev@var{chardevid}, else we will notify colo-frame 4281do checkpoint and send primary packet to outdev@var{chardevid}. 4282 4283we must use it with the help of filter-mirror and filter-redirector. 4284 4285@example 4286 4287primary: 4288-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown 4289-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66 4290-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait 4291-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait 4292-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait 4293-chardev socket,id=compare0-0,host=3.3.3.3,port=9001 4294-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait 4295-chardev socket,id=compare_out0,host=3.3.3.3,port=9005 4296-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 4297-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out 4298-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 4299-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0 4300 4301secondary: 4302-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown 4303-device e1000,netdev=hn0,mac=52:a4:00:12:78:66 4304-chardev socket,id=red0,host=3.3.3.3,port=9003 4305-chardev socket,id=red1,host=3.3.3.3,port=9004 4306-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 4307-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 4308 4309@end example 4310 4311If you want to know the detail of above command line, you can read 4312the colo-compare git log. 4313 4314@item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}] 4315 4316Creates a cryptodev backend which executes crypto opreation from 4317the QEMU cipher APIS. The @var{id} parameter is 4318a unique ID that will be used to reference this cryptodev backend from 4319the @option{virtio-crypto} device. The @var{queues} parameter is optional, 4320which specify the queue number of cryptodev backend, the default of 4321@var{queues} is 1. 4322 4323@example 4324 4325 # qemu-system-x86_64 \ 4326 [...] \ 4327 -object cryptodev-backend-builtin,id=cryptodev0 \ 4328 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \ 4329 [...] 4330@end example 4331 4332@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4333@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 4334 4335Defines a secret to store a password, encryption key, or some other sensitive 4336data. The sensitive data can either be passed directly via the @var{data} 4337parameter, or indirectly via the @var{file} parameter. Using the @var{data} 4338parameter is insecure unless the sensitive data is encrypted. 4339 4340The sensitive data can be provided in raw format (the default), or base64. 4341When encoded as JSON, the raw format only supports valid UTF-8 characters, 4342so base64 is recommended for sending binary data. QEMU will convert from 4343which ever format is provided to the format it needs internally. eg, an 4344RBD password can be provided in raw format, even though it will be base64 4345encoded when passed onto the RBD sever. 4346 4347For added protection, it is possible to encrypt the data associated with 4348a secret using the AES-256-CBC cipher. Use of encryption is indicated 4349by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 4350parameter provides the ID of a previously defined secret that contains 4351the AES-256 decryption key. This key should be 32-bytes long and be 4352base64 encoded. The @var{iv} parameter provides the random initialization 4353vector used for encryption of this particular secret and should be a 4354base64 encrypted string of the 16-byte IV. 4355 4356The simplest (insecure) usage is to provide the secret inline 4357 4358@example 4359 4360 # $QEMU -object secret,id=sec0,data=letmein,format=raw 4361 4362@end example 4363 4364The simplest secure usage is to provide the secret via a file 4365 4366 # echo -n "letmein" > mypasswd.txt 4367 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 4368 4369For greater security, AES-256-CBC should be used. To illustrate usage, 4370consider the openssl command line tool which can encrypt the data. Note 4371that when encrypting, the plaintext must be padded to the cipher block 4372size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 4373 4374First a master key needs to be created in base64 encoding: 4375 4376@example 4377 # openssl rand -base64 32 > key.b64 4378 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 4379@end example 4380 4381Each secret to be encrypted needs to have a random initialization vector 4382generated. These do not need to be kept secret 4383 4384@example 4385 # openssl rand -base64 16 > iv.b64 4386 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 4387@end example 4388 4389The secret to be defined can now be encrypted, in this case we're 4390telling openssl to base64 encode the result, but it could be left 4391as raw bytes if desired. 4392 4393@example 4394 # SECRET=$(echo -n "letmein" | 4395 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 4396@end example 4397 4398When launching QEMU, create a master secret pointing to @code{key.b64} 4399and specify that to be used to decrypt the user password. Pass the 4400contents of @code{iv.b64} to the second secret 4401 4402@example 4403 # $QEMU \ 4404 -object secret,id=secmaster0,format=base64,file=key.b64 \ 4405 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 4406 data=$SECRET,iv=$(<iv.b64) 4407@end example 4408 4409@end table 4410 4411ETEXI 4412 4413 4414HXCOMM This is the last statement. Insert new options before this line! 4415STEXI 4416@end table 4417ETEXI 4418
