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, tcg (default: tcg)\n" 35 " kernel_irqchip=on|off controls accelerated irqchip support\n" 36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 37 " kvm_shadow_mem=size of KVM shadow MMU\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 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n" 41 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 42 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 43 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 44 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n", 45 QEMU_ARCH_ALL) 46STEXI 47@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 48@findex -machine 49Select the emulated machine by @var{name}. Use @code{-machine help} to list 50available machines. Supported machine properties are: 51@table @option 52@item accel=@var{accels1}[:@var{accels2}[:...]] 53This is used to enable an accelerator. Depending on the target architecture, 54kvm, xen, or tcg can be available. By default, tcg is used. If there is more 55than one accelerator specified, the next one is used if the previous one fails 56to initialize. 57@item kernel_irqchip=on|off 58Enables in-kernel irqchip support for the chosen accelerator when available. 59@item gfx_passthru=on|off 60Enables IGD GFX passthrough support for the chosen machine when available. 61@item vmport=on|off|auto 62Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 63value based on accel. For accel=xen the default is off otherwise the default 64is on. 65@item kvm_shadow_mem=size 66Defines the size of the KVM shadow MMU. 67@item dump-guest-core=on|off 68Include guest memory in a core dump. The default is on. 69@item mem-merge=on|off 70Enables or disables memory merge support. This feature, when supported by 71the host, de-duplicates identical memory pages among VMs instances 72(enabled by default). 73@item iommu=on|off 74Enables or disables emulated Intel IOMMU (VT-d) support. The default is off. 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@end table 84ETEXI 85 86HXCOMM Deprecated by -machine 87DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 88 89DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 90 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 91STEXI 92@item -cpu @var{model} 93@findex -cpu 94Select CPU model (@code{-cpu help} for list and additional feature selection) 95ETEXI 96 97DEF("smp", HAS_ARG, QEMU_OPTION_smp, 98 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 99 " set the number of CPUs to 'n' [default=1]\n" 100 " maxcpus= maximum number of total cpus, including\n" 101 " offline CPUs for hotplug, etc\n" 102 " cores= number of CPU cores on one socket\n" 103 " threads= number of threads on one CPU core\n" 104 " sockets= number of discrete sockets in the system\n", 105 QEMU_ARCH_ALL) 106STEXI 107@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 108@findex -smp 109Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 110CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 111to 4. 112For the PC target, the number of @var{cores} per socket, the number 113of @var{threads} per cores and the total number of @var{sockets} can be 114specified. Missing values will be computed. If any on the three values is 115given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 116specifies the maximum number of hotpluggable CPUs. 117ETEXI 118 119DEF("numa", HAS_ARG, QEMU_OPTION_numa, 120 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n" 121 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL) 122STEXI 123@item -numa node[,mem=@var{size}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 124@itemx -numa node[,memdev=@var{id}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 125@findex -numa 126Simulate a multi node NUMA system. If @samp{mem}, @samp{memdev} 127and @samp{cpus} are omitted, resources are split equally. Also, note 128that the -@option{numa} option doesn't allocate any of the specified 129resources. That is, it just assigns existing resources to NUMA nodes. This 130means that one still has to use the @option{-m}, @option{-smp} options 131to allocate RAM and VCPUs respectively, and possibly @option{-object} 132to specify the memory backend for the @samp{memdev} suboption. 133 134@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one 135node uses @samp{memdev}, all of them have to use it. 136ETEXI 137 138DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 139 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 140 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 141STEXI 142@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 143@findex -add-fd 144 145Add a file descriptor to an fd set. Valid options are: 146 147@table @option 148@item fd=@var{fd} 149This option defines the file descriptor of which a duplicate is added to fd set. 150The file descriptor cannot be stdin, stdout, or stderr. 151@item set=@var{set} 152This option defines the ID of the fd set to add the file descriptor to. 153@item opaque=@var{opaque} 154This option defines a free-form string that can be used to describe @var{fd}. 155@end table 156 157You can open an image using pre-opened file descriptors from an fd set: 158@example 159qemu-system-i386 160-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 161-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 162-drive file=/dev/fdset/2,index=0,media=disk 163@end example 164ETEXI 165 166DEF("set", HAS_ARG, QEMU_OPTION_set, 167 "-set group.id.arg=value\n" 168 " set <arg> parameter for item <id> of type <group>\n" 169 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 170STEXI 171@item -set @var{group}.@var{id}.@var{arg}=@var{value} 172@findex -set 173Set parameter @var{arg} for item @var{id} of type @var{group}\n" 174ETEXI 175 176DEF("global", HAS_ARG, QEMU_OPTION_global, 177 "-global driver.property=value\n" 178 "-global driver=driver,property=property,value=value\n" 179 " set a global default for a driver property\n", 180 QEMU_ARCH_ALL) 181STEXI 182@item -global @var{driver}.@var{prop}=@var{value} 183@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 184@findex -global 185Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 186 187@example 188qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk 189@end example 190 191In particular, you can use this to set driver properties for devices which are 192created automatically by the machine model. To create a device which is not 193created automatically and set properties on it, use -@option{device}. 194 195-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 196driver=@var{driver},property=@var{prop},value=@var{value}. The 197longhand syntax works even when @var{driver} contains a dot. 198ETEXI 199 200DEF("boot", HAS_ARG, QEMU_OPTION_boot, 201 "-boot [order=drives][,once=drives][,menu=on|off]\n" 202 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 203 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 204 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 205 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 206 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 207 QEMU_ARCH_ALL) 208STEXI 209@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] 210@findex -boot 211Specify boot order @var{drives} as a string of drive letters. Valid 212drive letters depend on the target architecture. The x86 PC uses: a, b 213(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 214from network adapter 1-4), hard disk boot is the default. To apply a 215particular boot order only on the first startup, specify it via 216@option{once}. 217 218Interactive boot menus/prompts can be enabled via @option{menu=on} as far 219as firmware/BIOS supports them. The default is non-interactive boot. 220 221A splash picture could be passed to bios, enabling user to show it as logo, 222when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 223supports them. Currently Seabios for X86 system support it. 224limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 225format(true color). The resolution should be supported by the SVGA mode, so 226the recommended is 320x240, 640x480, 800x640. 227 228A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 229when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 230reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 231system support it. 232 233Do strict boot via @option{strict=on} as far as firmware/BIOS 234supports it. This only effects when boot priority is changed by 235bootindex options. The default is non-strict boot. 236 237@example 238# try to boot from network first, then from hard disk 239qemu-system-i386 -boot order=nc 240# boot from CD-ROM first, switch back to default order after reboot 241qemu-system-i386 -boot once=d 242# boot with a splash picture for 5 seconds. 243qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 244@end example 245 246Note: The legacy format '-boot @var{drives}' is still supported but its 247use is discouraged as it may be removed from future versions. 248ETEXI 249 250DEF("m", HAS_ARG, QEMU_OPTION_m, 251 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n" 252 " configure guest RAM\n" 253 " size: initial amount of guest memory\n" 254 " slots: number of hotplug slots (default: none)\n" 255 " maxmem: maximum amount of guest memory (default: none)\n" 256 "NOTE: Some architectures might enforce a specific granularity\n", 257 QEMU_ARCH_ALL) 258STEXI 259@item -m [size=]@var{megs}[,slots=n,maxmem=size] 260@findex -m 261Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 262Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 263megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 264could be used to set amount of hotpluggable memory slots and maximum amount of 265memory. Note that @var{maxmem} must be aligned to the page size. 266 267For example, the following command-line sets the guest startup RAM size to 2681GB, creates 3 slots to hotplug additional memory and sets the maximum 269memory the guest can reach to 4GB: 270 271@example 272qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 273@end example 274 275If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 276be enabled and the guest startup RAM will never increase. 277ETEXI 278 279DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 280 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 281STEXI 282@item -mem-path @var{path} 283@findex -mem-path 284Allocate guest RAM from a temporarily created file in @var{path}. 285ETEXI 286 287DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 288 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 289 QEMU_ARCH_ALL) 290STEXI 291@item -mem-prealloc 292@findex -mem-prealloc 293Preallocate memory when using -mem-path. 294ETEXI 295 296DEF("k", HAS_ARG, QEMU_OPTION_k, 297 "-k language use keyboard layout (for example 'fr' for French)\n", 298 QEMU_ARCH_ALL) 299STEXI 300@item -k @var{language} 301@findex -k 302Use keyboard layout @var{language} (for example @code{fr} for 303French). This option is only needed where it is not easy to get raw PC 304keycodes (e.g. on Macs, with some X11 servers or with a VNC 305display). You don't normally need to use it on PC/Linux or PC/Windows 306hosts. 307 308The available layouts are: 309@example 310ar de-ch es fo fr-ca hu ja mk no pt-br sv 311da en-gb et fr fr-ch is lt nl pl ru th 312de en-us fi fr-be hr it lv nl-be pt sl tr 313@end example 314 315The default is @code{en-us}. 316ETEXI 317 318 319DEF("audio-help", 0, QEMU_OPTION_audio_help, 320 "-audio-help print list of audio drivers and their options\n", 321 QEMU_ARCH_ALL) 322STEXI 323@item -audio-help 324@findex -audio-help 325Will show the audio subsystem help: list of drivers, tunable 326parameters. 327ETEXI 328 329DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 330 "-soundhw c1,... enable audio support\n" 331 " and only specified sound cards (comma separated list)\n" 332 " use '-soundhw help' to get the list of supported cards\n" 333 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 334STEXI 335@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 336@findex -soundhw 337Enable audio and selected sound hardware. Use 'help' to print all 338available sound hardware. 339 340@example 341qemu-system-i386 -soundhw sb16,adlib disk.img 342qemu-system-i386 -soundhw es1370 disk.img 343qemu-system-i386 -soundhw ac97 disk.img 344qemu-system-i386 -soundhw hda disk.img 345qemu-system-i386 -soundhw all disk.img 346qemu-system-i386 -soundhw help 347@end example 348 349Note that Linux's i810_audio OSS kernel (for AC97) module might 350require manually specifying clocking. 351 352@example 353modprobe i810_audio clocking=48000 354@end example 355ETEXI 356 357DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 358 "-balloon none disable balloon device\n" 359 "-balloon virtio[,addr=str]\n" 360 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL) 361STEXI 362@item -balloon none 363@findex -balloon 364Disable balloon device. 365@item -balloon virtio[,addr=@var{addr}] 366Enable virtio balloon device (default), optionally with PCI address 367@var{addr}. 368ETEXI 369 370DEF("device", HAS_ARG, QEMU_OPTION_device, 371 "-device driver[,prop[=value][,...]]\n" 372 " add device (based on driver)\n" 373 " prop=value,... sets driver properties\n" 374 " use '-device help' to print all possible drivers\n" 375 " use '-device driver,help' to print all possible properties\n", 376 QEMU_ARCH_ALL) 377STEXI 378@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 379@findex -device 380Add device @var{driver}. @var{prop}=@var{value} sets driver 381properties. Valid properties depend on the driver. To get help on 382possible drivers and properties, use @code{-device help} and 383@code{-device @var{driver},help}. 384ETEXI 385 386DEF("name", HAS_ARG, QEMU_OPTION_name, 387 "-name string1[,process=string2][,debug-threads=on|off]\n" 388 " set the name of the guest\n" 389 " string1 sets the window title and string2 the process name (on Linux)\n" 390 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 391 " NOTE: The thread names are for debugging and not a stable API.\n", 392 QEMU_ARCH_ALL) 393STEXI 394@item -name @var{name} 395@findex -name 396Sets the @var{name} of the guest. 397This name will be displayed in the SDL window caption. 398The @var{name} will also be used for the VNC server. 399Also optionally set the top visible process name in Linux. 400Naming of individual threads can also be enabled on Linux to aid debugging. 401ETEXI 402 403DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 404 "-uuid %08x-%04x-%04x-%04x-%012x\n" 405 " specify machine UUID\n", QEMU_ARCH_ALL) 406STEXI 407@item -uuid @var{uuid} 408@findex -uuid 409Set system UUID. 410ETEXI 411 412STEXI 413@end table 414ETEXI 415DEFHEADING() 416 417DEFHEADING(Block device options:) 418STEXI 419@table @option 420ETEXI 421 422DEF("fda", HAS_ARG, QEMU_OPTION_fda, 423 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 424DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 425STEXI 426@item -fda @var{file} 427@itemx -fdb @var{file} 428@findex -fda 429@findex -fdb 430Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 431ETEXI 432 433DEF("hda", HAS_ARG, QEMU_OPTION_hda, 434 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 435DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 436DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 437 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 438DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 439STEXI 440@item -hda @var{file} 441@itemx -hdb @var{file} 442@itemx -hdc @var{file} 443@itemx -hdd @var{file} 444@findex -hda 445@findex -hdb 446@findex -hdc 447@findex -hdd 448Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 449ETEXI 450 451DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 452 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 453 QEMU_ARCH_ALL) 454STEXI 455@item -cdrom @var{file} 456@findex -cdrom 457Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 458@option{-cdrom} at the same time). You can use the host CD-ROM by 459using @file{/dev/cdrom} as filename (@pxref{host_drives}). 460ETEXI 461 462DEF("drive", HAS_ARG, QEMU_OPTION_drive, 463 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 464 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n" 465 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 466 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n" 467 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 468 " [,readonly=on|off][,copy-on-read=on|off]\n" 469 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 470 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 471 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 472 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 473 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 474 " [[,iops_size=is]]\n" 475 " [[,group=g]]\n" 476 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 477STEXI 478@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 479@findex -drive 480 481Define a new drive. Valid options are: 482 483@table @option 484@item file=@var{file} 485This option defines which disk image (@pxref{disk_images}) to use with 486this drive. If the filename contains comma, you must double it 487(for instance, "file=my,,file" to use file "my,file"). 488 489Special files such as iSCSI devices can be specified using protocol 490specific URLs. See the section for "Device URL Syntax" for more information. 491@item if=@var{interface} 492This option defines on which type on interface the drive is connected. 493Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio. 494@item bus=@var{bus},unit=@var{unit} 495These options define where is connected the drive by defining the bus number and 496the unit id. 497@item index=@var{index} 498This option defines where is connected the drive by using an index in the list 499of available connectors of a given interface type. 500@item media=@var{media} 501This option defines the type of the media: disk or cdrom. 502@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}] 503These options have the same definition as they have in @option{-hdachs}. 504@item snapshot=@var{snapshot} 505@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 506(see @option{-snapshot}). 507@item cache=@var{cache} 508@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data. 509@item aio=@var{aio} 510@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 511@item discard=@var{discard} 512@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap}) requests are ignored or passed to the filesystem. Some machine types may not support discard requests. 513@item format=@var{format} 514Specify which disk @var{format} will be used rather than detecting 515the format. Can be used to specifiy format=raw to avoid interpreting 516an untrusted format header. 517@item serial=@var{serial} 518This option specifies the serial number to assign to the device. 519@item addr=@var{addr} 520Specify the controller's PCI address (if=virtio only). 521@item werror=@var{action},rerror=@var{action} 522Specify which @var{action} to take on write and read errors. Valid actions are: 523"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 524"report" (report the error to the guest), "enospc" (pause QEMU only if the 525host disk is full; report the error to the guest otherwise). 526The default setting is @option{werror=enospc} and @option{rerror=report}. 527@item readonly 528Open drive @option{file} as read-only. Guest write attempts will fail. 529@item copy-on-read=@var{copy-on-read} 530@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 531file sectors into the image file. 532@item detect-zeroes=@var{detect-zeroes} 533@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 534conversion of plain zero writes by the OS to driver specific optimized 535zero write commands. You may even choose "unmap" if @var{discard} is set 536to "unmap" to allow a zero write to be converted to an UNMAP operation. 537@end table 538 539By default, the @option{cache=writeback} mode is used. It will report data 540writes as completed as soon as the data is present in the host page cache. 541This is safe as long as your guest OS makes sure to correctly flush disk caches 542where needed. If your guest OS does not handle volatile disk write caches 543correctly and your host crashes or loses power, then the guest may experience 544data corruption. 545 546For such guests, you should consider using @option{cache=writethrough}. This 547means that the host page cache will be used to read and write data, but write 548notification will be sent to the guest only after QEMU has made sure to flush 549each write to the disk. Be aware that this has a major impact on performance. 550 551The host page cache can be avoided entirely with @option{cache=none}. This will 552attempt to do disk IO directly to the guest's memory. QEMU may still perform 553an internal copy of the data. Note that this is considered a writeback mode and 554the guest OS must handle the disk write cache correctly in order to avoid data 555corruption on host crashes. 556 557The host page cache can be avoided while only sending write notifications to 558the guest when the data has been flushed to the disk using 559@option{cache=directsync}. 560 561In case you don't care about data integrity over host failures, use 562@option{cache=unsafe}. This option tells QEMU that it never needs to write any 563data to the disk but can instead keep things in cache. If anything goes wrong, 564like your host losing power, the disk storage getting disconnected accidentally, 565etc. your image will most probably be rendered unusable. When using 566the @option{-snapshot} option, unsafe caching is always used. 567 568Copy-on-read avoids accessing the same backing file sectors repeatedly and is 569useful when the backing file is over a slow network. By default copy-on-read 570is off. 571 572Instead of @option{-cdrom} you can use: 573@example 574qemu-system-i386 -drive file=file,index=2,media=cdrom 575@end example 576 577Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 578use: 579@example 580qemu-system-i386 -drive file=file,index=0,media=disk 581qemu-system-i386 -drive file=file,index=1,media=disk 582qemu-system-i386 -drive file=file,index=2,media=disk 583qemu-system-i386 -drive file=file,index=3,media=disk 584@end example 585 586You can open an image using pre-opened file descriptors from an fd set: 587@example 588qemu-system-i386 589-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 590-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 591-drive file=/dev/fdset/2,index=0,media=disk 592@end example 593 594You can connect a CDROM to the slave of ide0: 595@example 596qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 597@end example 598 599If you don't specify the "file=" argument, you define an empty drive: 600@example 601qemu-system-i386 -drive if=ide,index=1,media=cdrom 602@end example 603 604You can connect a SCSI disk with unit ID 6 on the bus #0: 605@example 606qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6 607@end example 608 609Instead of @option{-fda}, @option{-fdb}, you can use: 610@example 611qemu-system-i386 -drive file=file,index=0,if=floppy 612qemu-system-i386 -drive file=file,index=1,if=floppy 613@end example 614 615By default, @var{interface} is "ide" and @var{index} is automatically 616incremented: 617@example 618qemu-system-i386 -drive file=a -drive file=b" 619@end example 620is interpreted like: 621@example 622qemu-system-i386 -hda a -hdb b 623@end example 624ETEXI 625 626DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 627 "-mtdblock file use 'file' as on-board Flash memory image\n", 628 QEMU_ARCH_ALL) 629STEXI 630@item -mtdblock @var{file} 631@findex -mtdblock 632Use @var{file} as on-board Flash memory image. 633ETEXI 634 635DEF("sd", HAS_ARG, QEMU_OPTION_sd, 636 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 637STEXI 638@item -sd @var{file} 639@findex -sd 640Use @var{file} as SecureDigital card image. 641ETEXI 642 643DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 644 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 645STEXI 646@item -pflash @var{file} 647@findex -pflash 648Use @var{file} as a parallel flash image. 649ETEXI 650 651DEF("snapshot", 0, QEMU_OPTION_snapshot, 652 "-snapshot write to temporary files instead of disk image files\n", 653 QEMU_ARCH_ALL) 654STEXI 655@item -snapshot 656@findex -snapshot 657Write to temporary files instead of disk image files. In this case, 658the raw disk image you use is not written back. You can however force 659the write back by pressing @key{C-a s} (@pxref{disk_images}). 660ETEXI 661 662DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \ 663 "-hdachs c,h,s[,t]\n" \ 664 " force hard disk 0 physical geometry and the optional BIOS\n" \ 665 " translation (t=none or lba) (usually QEMU can guess them)\n", 666 QEMU_ARCH_ALL) 667STEXI 668@item -hdachs @var{c},@var{h},@var{s},[,@var{t}] 669@findex -hdachs 670Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <= 671@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS 672translation mode (@var{t}=none, lba or auto). Usually QEMU can guess 673all those parameters. This option is useful for old MS-DOS disk 674images. 675ETEXI 676 677DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 678 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 679 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 680 QEMU_ARCH_ALL) 681 682STEXI 683 684@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}] 685@findex -fsdev 686Define a new file system device. Valid options are: 687@table @option 688@item @var{fsdriver} 689This option specifies the fs driver backend to use. 690Currently "local", "handle" and "proxy" file system drivers are supported. 691@item id=@var{id} 692Specifies identifier for this device 693@item path=@var{path} 694Specifies the export path for the file system device. Files under 695this path will be available to the 9p client on the guest. 696@item security_model=@var{security_model} 697Specifies the security model to be used for this export path. 698Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 699In "passthrough" security model, files are stored using the same 700credentials as they are created on the guest. This requires QEMU 701to run as root. In "mapped-xattr" security model, some of the file 702attributes like uid, gid, mode bits and link target are stored as 703file attributes. For "mapped-file" these attributes are stored in the 704hidden .virtfs_metadata directory. Directories exported by this security model cannot 705interact with other unix tools. "none" security model is same as 706passthrough except the sever won't report failures if it fails to 707set file attributes like ownership. Security model is mandatory 708only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 709security model as a parameter. 710@item writeout=@var{writeout} 711This is an optional argument. The only supported value is "immediate". 712This means that host page cache will be used to read and write data but 713write notification will be sent to the guest only when the data has been 714reported as written by the storage subsystem. 715@item readonly 716Enables exporting 9p share as a readonly mount for guests. By default 717read-write access is given. 718@item socket=@var{socket} 719Enables proxy filesystem driver to use passed socket file for communicating 720with virtfs-proxy-helper 721@item sock_fd=@var{sock_fd} 722Enables proxy filesystem driver to use passed socket descriptor for 723communicating with virtfs-proxy-helper. Usually a helper like libvirt 724will create socketpair and pass one of the fds as sock_fd 725@end table 726 727-fsdev option is used along with -device driver "virtio-9p-pci". 728@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 729Options for virtio-9p-pci driver are: 730@table @option 731@item fsdev=@var{id} 732Specifies the id value specified along with -fsdev option 733@item mount_tag=@var{mount_tag} 734Specifies the tag name to be used by the guest to mount this export point 735@end table 736 737ETEXI 738 739DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 740 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 741 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 742 QEMU_ARCH_ALL) 743 744STEXI 745 746@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}] 747@findex -virtfs 748 749The general form of a Virtual File system pass-through options are: 750@table @option 751@item @var{fsdriver} 752This option specifies the fs driver backend to use. 753Currently "local", "handle" and "proxy" file system drivers are supported. 754@item id=@var{id} 755Specifies identifier for this device 756@item path=@var{path} 757Specifies the export path for the file system device. Files under 758this path will be available to the 9p client on the guest. 759@item security_model=@var{security_model} 760Specifies the security model to be used for this export path. 761Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 762In "passthrough" security model, files are stored using the same 763credentials as they are created on the guest. This requires QEMU 764to run as root. In "mapped-xattr" security model, some of the file 765attributes like uid, gid, mode bits and link target are stored as 766file attributes. For "mapped-file" these attributes are stored in the 767hidden .virtfs_metadata directory. Directories exported by this security model cannot 768interact with other unix tools. "none" security model is same as 769passthrough except the sever won't report failures if it fails to 770set file attributes like ownership. Security model is mandatory only 771for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 772model as a parameter. 773@item writeout=@var{writeout} 774This is an optional argument. The only supported value is "immediate". 775This means that host page cache will be used to read and write data but 776write notification will be sent to the guest only when the data has been 777reported as written by the storage subsystem. 778@item readonly 779Enables exporting 9p share as a readonly mount for guests. By default 780read-write access is given. 781@item socket=@var{socket} 782Enables proxy filesystem driver to use passed socket file for 783communicating with virtfs-proxy-helper. Usually a helper like libvirt 784will create socketpair and pass one of the fds as sock_fd 785@item sock_fd 786Enables proxy filesystem driver to use passed 'sock_fd' as the socket 787descriptor for interfacing with virtfs-proxy-helper 788@end table 789ETEXI 790 791DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 792 "-virtfs_synth Create synthetic file system image\n", 793 QEMU_ARCH_ALL) 794STEXI 795@item -virtfs_synth 796@findex -virtfs_synth 797Create synthetic file system image 798ETEXI 799 800STEXI 801@end table 802ETEXI 803DEFHEADING() 804 805DEFHEADING(USB options:) 806STEXI 807@table @option 808ETEXI 809 810DEF("usb", 0, QEMU_OPTION_usb, 811 "-usb enable the USB driver (will be the default soon)\n", 812 QEMU_ARCH_ALL) 813STEXI 814@item -usb 815@findex -usb 816Enable the USB driver (will be the default soon) 817ETEXI 818 819DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 820 "-usbdevice name add the host or guest USB device 'name'\n", 821 QEMU_ARCH_ALL) 822STEXI 823 824@item -usbdevice @var{devname} 825@findex -usbdevice 826Add the USB device @var{devname}. @xref{usb_devices}. 827 828@table @option 829 830@item mouse 831Virtual Mouse. This will override the PS/2 mouse emulation when activated. 832 833@item tablet 834Pointer device that uses absolute coordinates (like a touchscreen). This 835means QEMU is able to report the mouse position without having to grab the 836mouse. Also overrides the PS/2 mouse emulation when activated. 837 838@item disk:[format=@var{format}]:@var{file} 839Mass storage device based on file. The optional @var{format} argument 840will be used rather than detecting the format. Can be used to specifiy 841@code{format=raw} to avoid interpreting an untrusted format header. 842 843@item host:@var{bus}.@var{addr} 844Pass through the host device identified by @var{bus}.@var{addr} (Linux only). 845 846@item host:@var{vendor_id}:@var{product_id} 847Pass through the host device identified by @var{vendor_id}:@var{product_id} 848(Linux only). 849 850@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev} 851Serial converter to host character device @var{dev}, see @code{-serial} for the 852available devices. 853 854@item braille 855Braille device. This will use BrlAPI to display the braille output on a real 856or fake device. 857 858@item net:@var{options} 859Network adapter that supports CDC ethernet and RNDIS protocols. 860 861@end table 862ETEXI 863 864STEXI 865@end table 866ETEXI 867DEFHEADING() 868 869DEFHEADING(Display options:) 870STEXI 871@table @option 872ETEXI 873 874DEF("display", HAS_ARG, QEMU_OPTION_display, 875 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 876 " [,window_close=on|off]|curses|none|\n" 877 " gtk[,grab_on_hover=on|off]|\n" 878 " vnc=<display>[,<optargs>]\n" 879 " select display type\n", QEMU_ARCH_ALL) 880STEXI 881@item -display @var{type} 882@findex -display 883Select type of display to use. This option is a replacement for the 884old style -sdl/-curses/... options. Valid values for @var{type} are 885@table @option 886@item sdl 887Display video output via SDL (usually in a separate graphics 888window; see the SDL documentation for other possibilities). 889@item curses 890Display video output via curses. For graphics device models which 891support a text mode, QEMU can display this output using a 892curses/ncurses interface. Nothing is displayed when the graphics 893device is in graphical mode or if the graphics device does not support 894a text mode. Generally only the VGA device models support text mode. 895@item none 896Do not display video output. The guest will still see an emulated 897graphics card, but its output will not be displayed to the QEMU 898user. This option differs from the -nographic option in that it 899only affects what is done with video output; -nographic also changes 900the destination of the serial and parallel port data. 901@item gtk 902Display video output in a GTK window. This interface provides drop-down 903menus and other UI elements to configure and control the VM during 904runtime. 905@item vnc 906Start a VNC server on display <arg> 907@end table 908ETEXI 909 910DEF("nographic", 0, QEMU_OPTION_nographic, 911 "-nographic disable graphical output and redirect serial I/Os to console\n", 912 QEMU_ARCH_ALL) 913STEXI 914@item -nographic 915@findex -nographic 916Normally, QEMU uses SDL to display the VGA output. With this option, 917you can totally disable graphical output so that QEMU is a simple 918command line application. The emulated serial port is redirected on 919the console and muxed with the monitor (unless redirected elsewhere 920explicitly). Therefore, you can still use QEMU to debug a Linux kernel 921with a serial console. Use @key{C-a h} for help on switching between 922the console and monitor. 923ETEXI 924 925DEF("curses", 0, QEMU_OPTION_curses, 926 "-curses use a curses/ncurses interface instead of SDL\n", 927 QEMU_ARCH_ALL) 928STEXI 929@item -curses 930@findex -curses 931Normally, QEMU uses SDL to display the VGA output. With this option, 932QEMU can display the VGA output when in text mode using a 933curses/ncurses interface. Nothing is displayed in graphical mode. 934ETEXI 935 936DEF("no-frame", 0, QEMU_OPTION_no_frame, 937 "-no-frame open SDL window without a frame and window decorations\n", 938 QEMU_ARCH_ALL) 939STEXI 940@item -no-frame 941@findex -no-frame 942Do not use decorations for SDL windows and start them using the whole 943available screen space. This makes the using QEMU in a dedicated desktop 944workspace more convenient. 945ETEXI 946 947DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 948 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 949 QEMU_ARCH_ALL) 950STEXI 951@item -alt-grab 952@findex -alt-grab 953Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 954affects the special keys (for fullscreen, monitor-mode switching, etc). 955ETEXI 956 957DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 958 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 959 QEMU_ARCH_ALL) 960STEXI 961@item -ctrl-grab 962@findex -ctrl-grab 963Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 964affects the special keys (for fullscreen, monitor-mode switching, etc). 965ETEXI 966 967DEF("no-quit", 0, QEMU_OPTION_no_quit, 968 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 969STEXI 970@item -no-quit 971@findex -no-quit 972Disable SDL window close capability. 973ETEXI 974 975DEF("sdl", 0, QEMU_OPTION_sdl, 976 "-sdl enable SDL\n", QEMU_ARCH_ALL) 977STEXI 978@item -sdl 979@findex -sdl 980Enable SDL. 981ETEXI 982 983DEF("spice", HAS_ARG, QEMU_OPTION_spice, 984 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 985 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 986 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 987 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 988 " [,tls-ciphers=<list>]\n" 989 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 990 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 991 " [,sasl][,password=<secret>][,disable-ticketing]\n" 992 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 993 " [,jpeg-wan-compression=[auto|never|always]]\n" 994 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 995 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 996 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 997 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 998 " enable spice\n" 999 " at least one of {port, tls-port} is mandatory\n", 1000 QEMU_ARCH_ALL) 1001STEXI 1002@item -spice @var{option}[,@var{option}[,...]] 1003@findex -spice 1004Enable the spice remote desktop protocol. Valid options are 1005 1006@table @option 1007 1008@item port=<nr> 1009Set the TCP port spice is listening on for plaintext channels. 1010 1011@item addr=<addr> 1012Set the IP address spice is listening on. Default is any address. 1013 1014@item ipv4 1015@itemx ipv6 1016@itemx unix 1017Force using the specified IP version. 1018 1019@item password=<secret> 1020Set the password you need to authenticate. 1021 1022@item sasl 1023Require that the client use SASL to authenticate with the spice. 1024The exact choice of authentication method used is controlled from the 1025system / user's SASL configuration file for the 'qemu' service. This 1026is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1027unprivileged user, an environment variable SASL_CONF_PATH can be used 1028to make it search alternate locations for the service config. 1029While some SASL auth methods can also provide data encryption (eg GSSAPI), 1030it is recommended that SASL always be combined with the 'tls' and 1031'x509' settings to enable use of SSL and server certificates. This 1032ensures a data encryption preventing compromise of authentication 1033credentials. 1034 1035@item disable-ticketing 1036Allow client connects without authentication. 1037 1038@item disable-copy-paste 1039Disable copy paste between the client and the guest. 1040 1041@item disable-agent-file-xfer 1042Disable spice-vdagent based file-xfer between the client and the guest. 1043 1044@item tls-port=<nr> 1045Set the TCP port spice is listening on for encrypted channels. 1046 1047@item x509-dir=<dir> 1048Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1049 1050@item x509-key-file=<file> 1051@itemx x509-key-password=<file> 1052@itemx x509-cert-file=<file> 1053@itemx x509-cacert-file=<file> 1054@itemx x509-dh-key-file=<file> 1055The x509 file names can also be configured individually. 1056 1057@item tls-ciphers=<list> 1058Specify which ciphers to use. 1059 1060@item tls-channel=[main|display|cursor|inputs|record|playback] 1061@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1062Force specific channel to be used with or without TLS encryption. The 1063options can be specified multiple times to configure multiple 1064channels. The special name "default" can be used to set the default 1065mode. For channels which are not explicitly forced into one mode the 1066spice client is allowed to pick tls/plaintext as he pleases. 1067 1068@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1069Configure image compression (lossless). 1070Default is auto_glz. 1071 1072@item jpeg-wan-compression=[auto|never|always] 1073@itemx zlib-glz-wan-compression=[auto|never|always] 1074Configure wan image compression (lossy for slow links). 1075Default is auto. 1076 1077@item streaming-video=[off|all|filter] 1078Configure video stream detection. Default is filter. 1079 1080@item agent-mouse=[on|off] 1081Enable/disable passing mouse events via vdagent. Default is on. 1082 1083@item playback-compression=[on|off] 1084Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1085 1086@item seamless-migration=[on|off] 1087Enable/disable spice seamless migration. Default is off. 1088 1089@end table 1090ETEXI 1091 1092DEF("portrait", 0, QEMU_OPTION_portrait, 1093 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1094 QEMU_ARCH_ALL) 1095STEXI 1096@item -portrait 1097@findex -portrait 1098Rotate graphical output 90 deg left (only PXA LCD). 1099ETEXI 1100 1101DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1102 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1103 QEMU_ARCH_ALL) 1104STEXI 1105@item -rotate @var{deg} 1106@findex -rotate 1107Rotate graphical output some deg left (only PXA LCD). 1108ETEXI 1109 1110DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1111 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1112 " select video card type\n", QEMU_ARCH_ALL) 1113STEXI 1114@item -vga @var{type} 1115@findex -vga 1116Select type of VGA card to emulate. Valid values for @var{type} are 1117@table @option 1118@item cirrus 1119Cirrus Logic GD5446 Video card. All Windows versions starting from 1120Windows 95 should recognize and use this graphic card. For optimal 1121performances, use 16 bit color depth in the guest and the host OS. 1122(This one is the default) 1123@item std 1124Standard VGA card with Bochs VBE extensions. If your guest OS 1125supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1126to use high resolution modes (>= 1280x1024x16) then you should use 1127this option. 1128@item vmware 1129VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1130recent XFree86/XOrg server or Windows guest with a driver for this 1131card. 1132@item qxl 1133QXL paravirtual graphic card. It is VGA compatible (including VESA 11342.0 VBE support). Works best with qxl guest drivers installed though. 1135Recommended choice when using the spice protocol. 1136@item tcx 1137(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1138sun4m machines and offers both 8-bit and 24-bit colour depths at a 1139fixed resolution of 1024x768. 1140@item cg3 1141(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1142for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1143resolutions aimed at people wishing to run older Solaris versions. 1144@item virtio 1145Virtio VGA card. 1146@item none 1147Disable VGA card. 1148@end table 1149ETEXI 1150 1151DEF("full-screen", 0, QEMU_OPTION_full_screen, 1152 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1153STEXI 1154@item -full-screen 1155@findex -full-screen 1156Start in full screen. 1157ETEXI 1158 1159DEF("g", 1, QEMU_OPTION_g , 1160 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1161 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1162STEXI 1163@item -g @var{width}x@var{height}[x@var{depth}] 1164@findex -g 1165Set the initial graphical resolution and depth (PPC, SPARC only). 1166ETEXI 1167 1168DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1169 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL) 1170STEXI 1171@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1172@findex -vnc 1173Normally, QEMU uses SDL to display the VGA output. With this option, 1174you can have QEMU listen on VNC display @var{display} and redirect the VGA 1175display over the VNC session. It is very useful to enable the usb 1176tablet device when using this option (option @option{-usbdevice 1177tablet}). When using the VNC display, you must use the @option{-k} 1178parameter to set the keyboard layout if you are not using en-us. Valid 1179syntax for the @var{display} is 1180 1181@table @option 1182 1183@item @var{host}:@var{d} 1184 1185TCP connections will only be allowed from @var{host} on display @var{d}. 1186By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1187be omitted in which case the server will accept connections from any host. 1188 1189@item unix:@var{path} 1190 1191Connections will be allowed over UNIX domain sockets where @var{path} is the 1192location of a unix socket to listen for connections on. 1193 1194@item none 1195 1196VNC is initialized but not started. The monitor @code{change} command 1197can be used to later start the VNC server. 1198 1199@end table 1200 1201Following the @var{display} value there may be one or more @var{option} flags 1202separated by commas. Valid options are 1203 1204@table @option 1205 1206@item reverse 1207 1208Connect to a listening VNC client via a ``reverse'' connection. The 1209client is specified by the @var{display}. For reverse network 1210connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1211is a TCP port number, not a display number. 1212 1213@item websocket 1214 1215Opens an additional TCP listening port dedicated to VNC Websocket connections. 1216By definition the Websocket port is 5700+@var{display}. If @var{host} is 1217specified connections will only be allowed from this host. 1218As an alternative the Websocket port could be specified by using 1219@code{websocket}=@var{port}. 1220If no TLS credentials are provided, the websocket connection runs in 1221unencrypted mode. If TLS credentials are provided, the websocket connection 1222requires encrypted client connections. 1223 1224@item password 1225 1226Require that password based authentication is used for client connections. 1227 1228The password must be set separately using the @code{set_password} command in 1229the @ref{pcsys_monitor}. The syntax to change your password is: 1230@code{set_password <protocol> <password>} where <protocol> could be either 1231"vnc" or "spice". 1232 1233If you would like to change <protocol> password expiration, you should use 1234@code{expire_password <protocol> <expiration-time>} where expiration time could 1235be one of the following options: now, never, +seconds or UNIX time of 1236expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1237to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1238date and time). 1239 1240You can also use keywords "now" or "never" for the expiration time to 1241allow <protocol> password to expire immediately or never expire. 1242 1243@item tls-creds=@var{ID} 1244 1245Provides the ID of a set of TLS credentials to use to secure the 1246VNC server. They will apply to both the normal VNC server socket 1247and the websocket socket (if enabled). Setting TLS credentials 1248will cause the VNC server socket to enable the VeNCrypt auth 1249mechanism. The credentials should have been previously created 1250using the @option{-object tls-creds} argument. 1251 1252The @option{tls-creds} parameter obsoletes the @option{tls}, 1253@option{x509}, and @option{x509verify} options, and as such 1254it is not permitted to set both new and old type options at 1255the same time. 1256 1257@item tls 1258 1259Require that client use TLS when communicating with the VNC server. This 1260uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1261attack. It is recommended that this option be combined with either the 1262@option{x509} or @option{x509verify} options. 1263 1264This option is now deprecated in favor of using the @option{tls-creds} 1265argument. 1266 1267@item x509=@var{/path/to/certificate/dir} 1268 1269Valid if @option{tls} is specified. Require that x509 credentials are used 1270for negotiating the TLS session. The server will send its x509 certificate 1271to the client. It is recommended that a password be set on the VNC server 1272to provide authentication of the client when this is used. The path following 1273this option specifies where the x509 certificates are to be loaded from. 1274See the @ref{vnc_security} section for details on generating certificates. 1275 1276This option is now deprecated in favour of using the @option{tls-creds} 1277argument. 1278 1279@item x509verify=@var{/path/to/certificate/dir} 1280 1281Valid if @option{tls} is specified. Require that x509 credentials are used 1282for negotiating the TLS session. The server will send its x509 certificate 1283to the client, and request that the client send its own x509 certificate. 1284The server will validate the client's certificate against the CA certificate, 1285and reject clients when validation fails. If the certificate authority is 1286trusted, this is a sufficient authentication mechanism. You may still wish 1287to set a password on the VNC server as a second authentication layer. The 1288path following this option specifies where the x509 certificates are to 1289be loaded from. See the @ref{vnc_security} section for details on generating 1290certificates. 1291 1292This option is now deprecated in favour of using the @option{tls-creds} 1293argument. 1294 1295@item sasl 1296 1297Require that the client use SASL to authenticate with the VNC server. 1298The exact choice of authentication method used is controlled from the 1299system / user's SASL configuration file for the 'qemu' service. This 1300is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1301unprivileged user, an environment variable SASL_CONF_PATH can be used 1302to make it search alternate locations for the service config. 1303While some SASL auth methods can also provide data encryption (eg GSSAPI), 1304it is recommended that SASL always be combined with the 'tls' and 1305'x509' settings to enable use of SSL and server certificates. This 1306ensures a data encryption preventing compromise of authentication 1307credentials. See the @ref{vnc_security} section for details on using 1308SASL authentication. 1309 1310@item acl 1311 1312Turn on access control lists for checking of the x509 client certificate 1313and SASL party. For x509 certs, the ACL check is made against the 1314certificate's distinguished name. This is something that looks like 1315@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1316made against the username, which depending on the SASL plugin, may 1317include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1318When the @option{acl} flag is set, the initial access list will be 1319empty, with a @code{deny} policy. Thus no one will be allowed to 1320use the VNC server until the ACLs have been loaded. This can be 1321achieved using the @code{acl} monitor command. 1322 1323@item lossy 1324 1325Enable lossy compression methods (gradient, JPEG, ...). If this 1326option is set, VNC client may receive lossy framebuffer updates 1327depending on its encoding settings. Enabling this option can save 1328a lot of bandwidth at the expense of quality. 1329 1330@item non-adaptive 1331 1332Disable adaptive encodings. Adaptive encodings are enabled by default. 1333An adaptive encoding will try to detect frequently updated screen regions, 1334and send updates in these regions using a lossy encoding (like JPEG). 1335This can be really helpful to save bandwidth when playing videos. Disabling 1336adaptive encodings restores the original static behavior of encodings 1337like Tight. 1338 1339@item share=[allow-exclusive|force-shared|ignore] 1340 1341Set display sharing policy. 'allow-exclusive' allows clients to ask 1342for exclusive access. As suggested by the rfb spec this is 1343implemented by dropping other connections. Connecting multiple 1344clients in parallel requires all clients asking for a shared session 1345(vncviewer: -shared switch). This is the default. 'force-shared' 1346disables exclusive client access. Useful for shared desktop sessions, 1347where you don't want someone forgetting specify -shared disconnect 1348everybody else. 'ignore' completely ignores the shared flag and 1349allows everybody connect unconditionally. Doesn't conform to the rfb 1350spec but is traditional QEMU behavior. 1351 1352@end table 1353ETEXI 1354 1355STEXI 1356@end table 1357ETEXI 1358ARCHHEADING(, QEMU_ARCH_I386) 1359 1360ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1361STEXI 1362@table @option 1363ETEXI 1364 1365DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1366 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1367 QEMU_ARCH_I386) 1368STEXI 1369@item -win2k-hack 1370@findex -win2k-hack 1371Use it when installing Windows 2000 to avoid a disk full bug. After 1372Windows 2000 is installed, you no longer need this option (this option 1373slows down the IDE transfers). 1374ETEXI 1375 1376HXCOMM Deprecated by -rtc 1377DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1378 1379DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1380 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1381 QEMU_ARCH_I386) 1382STEXI 1383@item -no-fd-bootchk 1384@findex -no-fd-bootchk 1385Disable boot signature checking for floppy disks in BIOS. May 1386be needed to boot from old floppy disks. 1387ETEXI 1388 1389DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1390 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1391STEXI 1392@item -no-acpi 1393@findex -no-acpi 1394Disable ACPI (Advanced Configuration and Power Interface) support. Use 1395it if your guest OS complains about ACPI problems (PC target machine 1396only). 1397ETEXI 1398 1399DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1400 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1401STEXI 1402@item -no-hpet 1403@findex -no-hpet 1404Disable HPET support. 1405ETEXI 1406 1407DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1408 "-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" 1409 " ACPI table description\n", QEMU_ARCH_I386) 1410STEXI 1411@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}]...] 1412@findex -acpitable 1413Add ACPI table with specified header fields and context from specified files. 1414For file=, take whole ACPI table from the specified files, including all 1415ACPI headers (possible overridden by other options). 1416For data=, only data 1417portion of the table is used, all header information is specified in the 1418command line. 1419ETEXI 1420 1421DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1422 "-smbios file=binary\n" 1423 " load SMBIOS entry from binary file\n" 1424 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1425 " [,uefi=on|off]\n" 1426 " specify SMBIOS type 0 fields\n" 1427 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1428 " [,uuid=uuid][,sku=str][,family=str]\n" 1429 " specify SMBIOS type 1 fields\n" 1430 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1431 " [,asset=str][,location=str]\n" 1432 " specify SMBIOS type 2 fields\n" 1433 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1434 " [,sku=str]\n" 1435 " specify SMBIOS type 3 fields\n" 1436 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1437 " [,asset=str][,part=str]\n" 1438 " specify SMBIOS type 4 fields\n" 1439 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1440 " [,asset=str][,part=str][,speed=%d]\n" 1441 " specify SMBIOS type 17 fields\n", 1442 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1443STEXI 1444@item -smbios file=@var{binary} 1445@findex -smbios 1446Load SMBIOS entry from binary file. 1447 1448@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1449Specify SMBIOS type 0 fields 1450 1451@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}] 1452Specify SMBIOS type 1 fields 1453 1454@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}] 1455Specify SMBIOS type 2 fields 1456 1457@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1458Specify SMBIOS type 3 fields 1459 1460@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1461Specify SMBIOS type 4 fields 1462 1463@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}] 1464Specify SMBIOS type 17 fields 1465ETEXI 1466 1467STEXI 1468@end table 1469ETEXI 1470DEFHEADING() 1471 1472DEFHEADING(Network options:) 1473STEXI 1474@table @option 1475ETEXI 1476 1477HXCOMM Legacy slirp options (now moved to -net user): 1478#ifdef CONFIG_SLIRP 1479DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1480DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1481DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1482#ifndef _WIN32 1483DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1484#endif 1485#endif 1486 1487DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1488#ifdef CONFIG_SLIRP 1489 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n" 1490 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n" 1491 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1492#ifndef _WIN32 1493 "[,smb=dir[,smbserver=addr]]\n" 1494#endif 1495 " configure a user mode network backend with ID 'str',\n" 1496 " its DHCP server and optional services\n" 1497#endif 1498#ifdef _WIN32 1499 "-netdev tap,id=str,ifname=name\n" 1500 " configure a host TAP network backend with ID 'str'\n" 1501#else 1502 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1503 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1504 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1505 " configure a host TAP network backend with ID 'str'\n" 1506 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1507 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1508 " to deconfigure it\n" 1509 " use '[down]script=no' to disable script execution\n" 1510 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1511 " configure it\n" 1512 " use 'fd=h' to connect to an already opened TAP interface\n" 1513 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1514 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1515 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1516 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1517 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1518 " use vhost=on to enable experimental in kernel accelerator\n" 1519 " (only has effect for virtio guests which use MSIX)\n" 1520 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1521 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1522 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1523 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1524 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1525 " configure a host TAP network backend with ID 'str' that is\n" 1526 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1527 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1528#endif 1529#ifdef __linux__ 1530 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1531 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1532 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1533 " [,rxcookie=rxcookie][,offset=offset]\n" 1534 " configure a network backend with ID 'str' connected to\n" 1535 " an Ethernet over L2TPv3 pseudowire.\n" 1536 " Linux kernel 3.3+ as well as most routers can talk\n" 1537 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1538 " VM to a router and even VM to Host. It is a nearly-universal\n" 1539 " standard (RFC3391). Note - this implementation uses static\n" 1540 " pre-configured tunnels (same as the Linux kernel).\n" 1541 " use 'src=' to specify source address\n" 1542 " use 'dst=' to specify destination address\n" 1543 " use 'udp=on' to specify udp encapsulation\n" 1544 " use 'srcport=' to specify source udp port\n" 1545 " use 'dstport=' to specify destination udp port\n" 1546 " use 'ipv6=on' to force v6\n" 1547 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1548 " well as a weak security measure\n" 1549 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1550 " use 'txcookie=0x012345678' to specify a txcookie\n" 1551 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1552 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1553 " use 'pincounter=on' to work around broken counter handling in peer\n" 1554 " use 'offset=X' to add an extra offset between header and data\n" 1555#endif 1556 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1557 " configure a network backend to connect to another network\n" 1558 " using a socket connection\n" 1559 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1560 " configure a network backend to connect to a multicast maddr and port\n" 1561 " use 'localaddr=addr' to specify the host address to send packets from\n" 1562 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1563 " configure a network backend to connect to another network\n" 1564 " using an UDP tunnel\n" 1565#ifdef CONFIG_VDE 1566 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1567 " configure a network backend to connect to port 'n' of a vde switch\n" 1568 " running on host and listening for incoming connections on 'socketpath'.\n" 1569 " Use group 'groupname' and mode 'octalmode' to change default\n" 1570 " ownership and permissions for communication port.\n" 1571#endif 1572#ifdef CONFIG_NETMAP 1573 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 1574 " attach to the existing netmap-enabled network interface 'name', or to a\n" 1575 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 1576 " netmap device, defaults to '/dev/netmap')\n" 1577#endif 1578 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 1579 " configure a vhost-user network, backed by a chardev 'dev'\n" 1580 "-netdev hubport,id=str,hubid=n\n" 1581 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL) 1582DEF("net", HAS_ARG, QEMU_OPTION_net, 1583 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 1584 " old way to create a new NIC and connect it to VLAN 'n'\n" 1585 " (use the '-device devtype,netdev=str' option if possible instead)\n" 1586 "-net dump[,vlan=n][,file=f][,len=n]\n" 1587 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n" 1588 "-net none use it alone to have zero network devices. If no -net option\n" 1589 " is provided, the default is '-net nic -net user'\n" 1590 "-net [" 1591#ifdef CONFIG_SLIRP 1592 "user|" 1593#endif 1594 "tap|" 1595 "bridge|" 1596#ifdef CONFIG_VDE 1597 "vde|" 1598#endif 1599#ifdef CONFIG_NETMAP 1600 "netmap|" 1601#endif 1602 "socket][,vlan=n][,option][,option][,...]\n" 1603 " old way to initialize a host network interface\n" 1604 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 1605STEXI 1606@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 1607@findex -net 1608Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n} 1609= 0 is the default). The NIC is an e1000 by default on the PC 1610target. Optionally, the MAC address can be changed to @var{mac}, the 1611device address set to @var{addr} (PCI cards only), 1612and a @var{name} can be assigned for use in monitor commands. 1613Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 1614that the card should have; this option currently only affects virtio cards; set 1615@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 1616NIC is created. QEMU can emulate several different models of network card. 1617Valid values for @var{type} are 1618@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er}, 1619@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139}, 1620@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}. 1621Not all devices are supported on all targets. Use @code{-net nic,model=help} 1622for a list of available devices for your target. 1623 1624@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 1625@findex -netdev 1626@item -net user[,@var{option}][,@var{option}][,...] 1627Use the user mode network stack which requires no administrator 1628privilege to run. Valid options are: 1629 1630@table @option 1631@item vlan=@var{n} 1632Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default). 1633 1634@item id=@var{id} 1635@itemx name=@var{name} 1636Assign symbolic name for use in monitor commands. 1637 1638@item net=@var{addr}[/@var{mask}] 1639Set IP network address the guest will see. Optionally specify the netmask, 1640either in the form a.b.c.d or as number of valid top-most bits. Default is 164110.0.2.0/24. 1642 1643@item host=@var{addr} 1644Specify the guest-visible address of the host. Default is the 2nd IP in the 1645guest network, i.e. x.x.x.2. 1646 1647@item restrict=on|off 1648If this option is enabled, the guest will be isolated, i.e. it will not be 1649able to contact the host and no guest IP packets will be routed over the host 1650to the outside. This option does not affect any explicitly set forwarding rules. 1651 1652@item hostname=@var{name} 1653Specifies the client hostname reported by the built-in DHCP server. 1654 1655@item dhcpstart=@var{addr} 1656Specify the first of the 16 IPs the built-in DHCP server can assign. Default 1657is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 1658 1659@item dns=@var{addr} 1660Specify the guest-visible address of the virtual nameserver. The address must 1661be different from the host address. Default is the 3rd IP in the guest network, 1662i.e. x.x.x.3. 1663 1664@item dnssearch=@var{domain} 1665Provides an entry for the domain-search list sent by the built-in 1666DHCP server. More than one domain suffix can be transmitted by specifying 1667this option multiple times. If supported, this will cause the guest to 1668automatically try to append the given domain suffix(es) in case a domain name 1669can not be resolved. 1670 1671Example: 1672@example 1673qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...] 1674@end example 1675 1676@item tftp=@var{dir} 1677When using the user mode network stack, activate a built-in TFTP 1678server. The files in @var{dir} will be exposed as the root of a TFTP server. 1679The TFTP client on the guest must be configured in binary mode (use the command 1680@code{bin} of the Unix TFTP client). 1681 1682@item bootfile=@var{file} 1683When using the user mode network stack, broadcast @var{file} as the BOOTP 1684filename. In conjunction with @option{tftp}, this can be used to network boot 1685a guest from a local directory. 1686 1687Example (using pxelinux): 1688@example 1689qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 1690@end example 1691 1692@item smb=@var{dir}[,smbserver=@var{addr}] 1693When using the user mode network stack, activate a built-in SMB 1694server so that Windows OSes can access to the host files in @file{@var{dir}} 1695transparently. The IP address of the SMB server can be set to @var{addr}. By 1696default the 4th IP in the guest network is used, i.e. x.x.x.4. 1697 1698In the guest Windows OS, the line: 1699@example 170010.0.2.4 smbserver 1701@end example 1702must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 1703or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 1704 1705Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 1706 1707Note that a SAMBA server must be installed on the host OS. 1708QEMU was tested successfully with smbd versions from Red Hat 9, 1709Fedora Core 3 and OpenSUSE 11.x. 1710 1711@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 1712Redirect incoming TCP or UDP connections to the host port @var{hostport} to 1713the guest IP address @var{guestaddr} on guest port @var{guestport}. If 1714@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 1715given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 1716be bound to a specific host interface. If no connection type is set, TCP is 1717used. This option can be given multiple times. 1718 1719For example, to redirect host X11 connection from screen 1 to guest 1720screen 0, use the following: 1721 1722@example 1723# on the host 1724qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...] 1725# this host xterm should open in the guest X11 server 1726xterm -display :1 1727@end example 1728 1729To redirect telnet connections from host port 5555 to telnet port on 1730the guest, use the following: 1731 1732@example 1733# on the host 1734qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...] 1735telnet localhost 5555 1736@end example 1737 1738Then when you use on the host @code{telnet localhost 5555}, you 1739connect to the guest telnet server. 1740 1741@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 1742@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 1743Forward guest TCP connections to the IP address @var{server} on port @var{port} 1744to the character device @var{dev} or to a program executed by @var{cmd:command} 1745which gets spawned for each connection. This option can be given multiple times. 1746 1747You can either use a chardev directly and have that one used throughout QEMU's 1748lifetime, like in the following example: 1749 1750@example 1751# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 1752# the guest accesses it 1753qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...] 1754@end example 1755 1756Or you can execute a command on every TCP connection established by the guest, 1757so that QEMU behaves similar to an inetd process for that virtual server: 1758 1759@example 1760# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 1761# and connect the TCP stream to its stdin/stdout 1762qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 1763@end example 1764 1765@end table 1766 1767Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 1768processed and applied to -net user. Mixing them with the new configuration 1769syntax gives undefined results. Their use for new applications is discouraged 1770as they will be removed from future versions. 1771 1772@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1773@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1774Connect the host TAP network interface @var{name} to VLAN @var{n}. 1775 1776Use the network script @var{file} to configure it and the network script 1777@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 1778automatically provides one. The default network configure script is 1779@file{/etc/qemu-ifup} and the default network deconfigure script is 1780@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 1781to disable script execution. 1782 1783If running QEMU as an unprivileged user, use the network helper 1784@var{helper} to configure the TAP interface. The default network 1785helper executable is @file{/path/to/qemu-bridge-helper}. 1786 1787@option{fd}=@var{h} can be used to specify the handle of an already 1788opened host TAP interface. 1789 1790Examples: 1791 1792@example 1793#launch a QEMU instance with the default network script 1794qemu-system-i386 linux.img -net nic -net tap 1795@end example 1796 1797@example 1798#launch a QEMU instance with two NICs, each one connected 1799#to a TAP device 1800qemu-system-i386 linux.img \ 1801 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ 1802 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 1803@end example 1804 1805@example 1806#launch a QEMU instance with the default network helper to 1807#connect a TAP device to bridge br0 1808qemu-system-i386 linux.img \ 1809 -net nic -net tap,"helper=/path/to/qemu-bridge-helper" 1810@end example 1811 1812@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 1813@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}] 1814Connect a host TAP network interface to a host bridge device. 1815 1816Use the network helper @var{helper} to configure the TAP interface and 1817attach it to the bridge. The default network helper executable is 1818@file{/path/to/qemu-bridge-helper} and the default bridge 1819device is @file{br0}. 1820 1821Examples: 1822 1823@example 1824#launch a QEMU instance with the default network helper to 1825#connect a TAP device to bridge br0 1826qemu-system-i386 linux.img -net bridge -net nic,model=virtio 1827@end example 1828 1829@example 1830#launch a QEMU instance with the default network helper to 1831#connect a TAP device to bridge qemubr0 1832qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio 1833@end example 1834 1835@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1836@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1837 1838Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual 1839machine using a TCP socket connection. If @option{listen} is 1840specified, QEMU waits for incoming connections on @var{port} 1841(@var{host} is optional). @option{connect} is used to connect to 1842another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 1843specifies an already opened TCP socket. 1844 1845Example: 1846@example 1847# launch a first QEMU instance 1848qemu-system-i386 linux.img \ 1849 -net nic,macaddr=52:54:00:12:34:56 \ 1850 -net socket,listen=:1234 1851# connect the VLAN 0 of this instance to the VLAN 0 1852# of the first instance 1853qemu-system-i386 linux.img \ 1854 -net nic,macaddr=52:54:00:12:34:57 \ 1855 -net socket,connect=127.0.0.1:1234 1856@end example 1857 1858@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1859@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1860 1861Create a VLAN @var{n} shared with another QEMU virtual 1862machines using a UDP multicast socket, effectively making a bus for 1863every QEMU with same multicast address @var{maddr} and @var{port}. 1864NOTES: 1865@enumerate 1866@item 1867Several QEMU can be running on different hosts and share same bus (assuming 1868correct multicast setup for these hosts). 1869@item 1870mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 1871@url{http://user-mode-linux.sf.net}. 1872@item 1873Use @option{fd=h} to specify an already opened UDP multicast socket. 1874@end enumerate 1875 1876Example: 1877@example 1878# launch one QEMU instance 1879qemu-system-i386 linux.img \ 1880 -net nic,macaddr=52:54:00:12:34:56 \ 1881 -net socket,mcast=230.0.0.1:1234 1882# launch another QEMU instance on same "bus" 1883qemu-system-i386 linux.img \ 1884 -net nic,macaddr=52:54:00:12:34:57 \ 1885 -net socket,mcast=230.0.0.1:1234 1886# launch yet another QEMU instance on same "bus" 1887qemu-system-i386 linux.img \ 1888 -net nic,macaddr=52:54:00:12:34:58 \ 1889 -net socket,mcast=230.0.0.1:1234 1890@end example 1891 1892Example (User Mode Linux compat.): 1893@example 1894# launch QEMU instance (note mcast address selected 1895# is UML's default) 1896qemu-system-i386 linux.img \ 1897 -net nic,macaddr=52:54:00:12:34:56 \ 1898 -net socket,mcast=239.192.168.1:1102 1899# launch UML 1900/path/to/linux ubd0=/path/to/root_fs eth0=mcast 1901@end example 1902 1903Example (send packets from host's 1.2.3.4): 1904@example 1905qemu-system-i386 linux.img \ 1906 -net nic,macaddr=52:54:00:12:34:56 \ 1907 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 1908@end example 1909 1910@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}] 1911@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}] 1912Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular 1913protocol to transport Ethernet (and other Layer 2) data frames between 1914two systems. It is present in routers, firewalls and the Linux kernel 1915(from version 3.3 onwards). 1916 1917This transport allows a VM to communicate to another VM, router or firewall directly. 1918 1919@item src=@var{srcaddr} 1920 source address (mandatory) 1921@item dst=@var{dstaddr} 1922 destination address (mandatory) 1923@item udp 1924 select udp encapsulation (default is ip). 1925@item srcport=@var{srcport} 1926 source udp port. 1927@item dstport=@var{dstport} 1928 destination udp port. 1929@item ipv6 1930 force v6, otherwise defaults to v4. 1931@item rxcookie=@var{rxcookie} 1932@itemx txcookie=@var{txcookie} 1933 Cookies are a weak form of security in the l2tpv3 specification. 1934Their function is mostly to prevent misconfiguration. By default they are 32 1935bit. 1936@item cookie64 1937 Set cookie size to 64 bit instead of the default 32 1938@item counter=off 1939 Force a 'cut-down' L2TPv3 with no counter as in 1940draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 1941@item pincounter=on 1942 Work around broken counter handling in peer. This may also help on 1943networks which have packet reorder. 1944@item offset=@var{offset} 1945 Add an extra offset between header and data 1946 1947For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 1948on the remote Linux host 1.2.3.4: 1949@example 1950# Setup tunnel on linux host using raw ip as encapsulation 1951# on 1.2.3.4 1952ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 1953 encap udp udp_sport 16384 udp_dport 16384 1954ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 1955 0xFFFFFFFF peer_session_id 0xFFFFFFFF 1956ifconfig vmtunnel0 mtu 1500 1957ifconfig vmtunnel0 up 1958brctl addif br-lan vmtunnel0 1959 1960 1961# on 4.3.2.1 1962# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 1963 1964qemu-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 1965 1966 1967@end example 1968 1969@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 1970@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 1971Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and 1972listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 1973and MODE @var{octalmode} to change default ownership and permissions for 1974communication port. This option is only available if QEMU has been compiled 1975with vde support enabled. 1976 1977Example: 1978@example 1979# launch vde switch 1980vde_switch -F -sock /tmp/myswitch 1981# launch QEMU instance 1982qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch 1983@end example 1984 1985@item -netdev hubport,id=@var{id},hubid=@var{hubid} 1986 1987Create a hub port on QEMU "vlan" @var{hubid}. 1988 1989The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single 1990netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the 1991required hub automatically. 1992 1993@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 1994 1995Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 1996be a unix domain socket backed one. The vhost-user uses a specifically defined 1997protocol to pass vhost ioctl replacement messages to an application on the other 1998end of the socket. On non-MSIX guests, the feature can be forced with 1999@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2000be created for multiqueue vhost-user. 2001 2002Example: 2003@example 2004qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2005 -numa node,memdev=mem \ 2006 -chardev socket,path=/path/to/socket \ 2007 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2008 -device virtio-net-pci,netdev=net0 2009@end example 2010 2011@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}] 2012Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default). 2013At most @var{len} bytes (64k by default) per packet are stored. The file format is 2014libpcap, so it can be analyzed with tools such as tcpdump or Wireshark. 2015Note: For devices created with '-netdev', use '-object filter-dump,...' instead. 2016 2017@item -net none 2018Indicate that no network devices should be configured. It is used to 2019override the default configuration (@option{-net nic -net user}) which 2020is activated if no @option{-net} options are provided. 2021ETEXI 2022 2023STEXI 2024@end table 2025ETEXI 2026DEFHEADING() 2027 2028DEFHEADING(Character device options:) 2029STEXI 2030 2031The general form of a character device option is: 2032@table @option 2033ETEXI 2034 2035DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2036 "-chardev null,id=id[,mux=on|off]\n" 2037 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2038 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (tcp)\n" 2039 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (unix)\n" 2040 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2041 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2042 "-chardev msmouse,id=id[,mux=on|off]\n" 2043 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2044 " [,mux=on|off]\n" 2045 "-chardev ringbuf,id=id[,size=size]\n" 2046 "-chardev file,id=id,path=path[,mux=on|off]\n" 2047 "-chardev pipe,id=id,path=path[,mux=on|off]\n" 2048#ifdef _WIN32 2049 "-chardev console,id=id[,mux=on|off]\n" 2050 "-chardev serial,id=id,path=path[,mux=on|off]\n" 2051#else 2052 "-chardev pty,id=id[,mux=on|off]\n" 2053 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n" 2054#endif 2055#ifdef CONFIG_BRLAPI 2056 "-chardev braille,id=id[,mux=on|off]\n" 2057#endif 2058#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2059 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2060 "-chardev serial,id=id,path=path[,mux=on|off]\n" 2061 "-chardev tty,id=id,path=path[,mux=on|off]\n" 2062#endif 2063#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2064 "-chardev parallel,id=id,path=path[,mux=on|off]\n" 2065 "-chardev parport,id=id,path=path[,mux=on|off]\n" 2066#endif 2067#if defined(CONFIG_SPICE) 2068 "-chardev spicevmc,id=id,name=name[,debug=debug]\n" 2069 "-chardev spiceport,id=id,name=name[,debug=debug]\n" 2070#endif 2071 , QEMU_ARCH_ALL 2072) 2073 2074STEXI 2075@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}] 2076@findex -chardev 2077Backend is one of: 2078@option{null}, 2079@option{socket}, 2080@option{udp}, 2081@option{msmouse}, 2082@option{vc}, 2083@option{ringbuf}, 2084@option{file}, 2085@option{pipe}, 2086@option{console}, 2087@option{serial}, 2088@option{pty}, 2089@option{stdio}, 2090@option{braille}, 2091@option{tty}, 2092@option{parallel}, 2093@option{parport}, 2094@option{spicevmc}. 2095@option{spiceport}. 2096The specific backend will determine the applicable options. 2097 2098All devices must have an id, which can be any string up to 127 characters long. 2099It is used to uniquely identify this device in other command line directives. 2100 2101A character device may be used in multiplexing mode by multiple front-ends. 2102The key sequence of @key{Control-a} and @key{c} will rotate the input focus 2103between attached front-ends. Specify @option{mux=on} to enable this mode. 2104 2105Options to each backend are described below. 2106 2107@item -chardev null ,id=@var{id} 2108A void device. This device will not emit any data, and will drop any data it 2109receives. The null backend does not take any options. 2110 2111@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] 2112 2113Create a two-way stream socket, which can be either a TCP or a unix socket. A 2114unix socket will be created if @option{path} is specified. Behaviour is 2115undefined if TCP options are specified for a unix socket. 2116 2117@option{server} specifies that the socket shall be a listening socket. 2118 2119@option{nowait} specifies that QEMU should not block waiting for a client to 2120connect to a listening socket. 2121 2122@option{telnet} specifies that traffic on the socket should interpret telnet 2123escape sequences. 2124 2125@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2126the remote end goes away. qemu will delay this many seconds and then attempt 2127to reconnect. Zero disables reconnecting, and is the default. 2128 2129TCP and unix socket options are given below: 2130 2131@table @option 2132 2133@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay] 2134 2135@option{host} for a listening socket specifies the local address to be bound. 2136For a connecting socket species the remote host to connect to. @option{host} is 2137optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2138 2139@option{port} for a listening socket specifies the local port to be bound. For a 2140connecting socket specifies the port on the remote host to connect to. 2141@option{port} can be given as either a port number or a service name. 2142@option{port} is required. 2143 2144@option{to} is only relevant to listening sockets. If it is specified, and 2145@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2146to and including @option{to} until it succeeds. @option{to} must be specified 2147as a port number. 2148 2149@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2150If neither is specified the socket may use either protocol. 2151 2152@option{nodelay} disables the Nagle algorithm. 2153 2154@item unix options: path=@var{path} 2155 2156@option{path} specifies the local path of the unix socket. @option{path} is 2157required. 2158 2159@end table 2160 2161@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6] 2162 2163Sends all traffic from the guest to a remote host over UDP. 2164 2165@option{host} specifies the remote host to connect to. If not specified it 2166defaults to @code{localhost}. 2167 2168@option{port} specifies the port on the remote host to connect to. @option{port} 2169is required. 2170 2171@option{localaddr} specifies the local address to bind to. If not specified it 2172defaults to @code{0.0.0.0}. 2173 2174@option{localport} specifies the local port to bind to. If not specified any 2175available local port will be used. 2176 2177@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2178If neither is specified the device may use either protocol. 2179 2180@item -chardev msmouse ,id=@var{id} 2181 2182Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2183take any options. 2184 2185@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]] 2186 2187Connect to a QEMU text console. @option{vc} may optionally be given a specific 2188size. 2189 2190@option{width} and @option{height} specify the width and height respectively of 2191the console, in pixels. 2192 2193@option{cols} and @option{rows} specify that the console be sized to fit a text 2194console with the given dimensions. 2195 2196@item -chardev ringbuf ,id=@var{id} [,size=@var{size}] 2197 2198Create a ring buffer with fixed size @option{size}. 2199@var{size} must be a power of two, and defaults to @code{64K}). 2200 2201@item -chardev file ,id=@var{id} ,path=@var{path} 2202 2203Log all traffic received from the guest to a file. 2204 2205@option{path} specifies the path of the file to be opened. This file will be 2206created if it does not already exist, and overwritten if it does. @option{path} 2207is required. 2208 2209@item -chardev pipe ,id=@var{id} ,path=@var{path} 2210 2211Create a two-way connection to the guest. The behaviour differs slightly between 2212Windows hosts and other hosts: 2213 2214On Windows, a single duplex pipe will be created at 2215@file{\\.pipe\@option{path}}. 2216 2217On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2218@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2219received by the guest. Data written by the guest can be read from 2220@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2221be present. 2222 2223@option{path} forms part of the pipe path as described above. @option{path} is 2224required. 2225 2226@item -chardev console ,id=@var{id} 2227 2228Send traffic from the guest to QEMU's standard output. @option{console} does not 2229take any options. 2230 2231@option{console} is only available on Windows hosts. 2232 2233@item -chardev serial ,id=@var{id} ,path=@option{path} 2234 2235Send traffic from the guest to a serial device on the host. 2236 2237On Unix hosts serial will actually accept any tty device, 2238not only serial lines. 2239 2240@option{path} specifies the name of the serial device to open. 2241 2242@item -chardev pty ,id=@var{id} 2243 2244Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2245not take any options. 2246 2247@option{pty} is not available on Windows hosts. 2248 2249@item -chardev stdio ,id=@var{id} [,signal=on|off] 2250Connect to standard input and standard output of the QEMU process. 2251 2252@option{signal} controls if signals are enabled on the terminal, that includes 2253exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2254default, use @option{signal=off} to disable it. 2255 2256@option{stdio} is not available on Windows hosts. 2257 2258@item -chardev braille ,id=@var{id} 2259 2260Connect to a local BrlAPI server. @option{braille} does not take any options. 2261 2262@item -chardev tty ,id=@var{id} ,path=@var{path} 2263 2264@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2265DragonFlyBSD hosts. It is an alias for @option{serial}. 2266 2267@option{path} specifies the path to the tty. @option{path} is required. 2268 2269@item -chardev parallel ,id=@var{id} ,path=@var{path} 2270@itemx -chardev parport ,id=@var{id} ,path=@var{path} 2271 2272@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2273 2274Connect to a local parallel port. 2275 2276@option{path} specifies the path to the parallel port device. @option{path} is 2277required. 2278 2279@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2280 2281@option{spicevmc} is only available when spice support is built in. 2282 2283@option{debug} debug level for spicevmc 2284 2285@option{name} name of spice channel to connect to 2286 2287Connect to a spice virtual machine channel, such as vdiport. 2288 2289@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2290 2291@option{spiceport} is only available when spice support is built in. 2292 2293@option{debug} debug level for spicevmc 2294 2295@option{name} name of spice port to connect to 2296 2297Connect to a spice port, allowing a Spice client to handle the traffic 2298identified by a name (preferably a fqdn). 2299ETEXI 2300 2301STEXI 2302@end table 2303ETEXI 2304DEFHEADING() 2305 2306DEFHEADING(Device URL Syntax:) 2307STEXI 2308 2309In addition to using normal file images for the emulated storage devices, 2310QEMU can also use networked resources such as iSCSI devices. These are 2311specified using a special URL syntax. 2312 2313@table @option 2314@item iSCSI 2315iSCSI support allows QEMU to access iSCSI resources directly and use as 2316images for the guest storage. Both disk and cdrom images are supported. 2317 2318Syntax for specifying iSCSI LUNs is 2319``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>'' 2320 2321By default qemu will use the iSCSI initiator-name 2322'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command 2323line or a configuration file. 2324 2325Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect 2326stalled requests and force a reestablishment of the session. The timeout 2327is specified in seconds. The default is 0 which means no timeout. Libiscsi 23281.15.0 or greater is required for this feature. 2329 2330Example (without authentication): 2331@example 2332qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \ 2333 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \ 2334 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2335@end example 2336 2337Example (CHAP username/password via URL): 2338@example 2339qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1 2340@end example 2341 2342Example (CHAP username/password via environment variables): 2343@example 2344LIBISCSI_CHAP_USERNAME="user" \ 2345LIBISCSI_CHAP_PASSWORD="password" \ 2346qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2347@end example 2348 2349iSCSI support is an optional feature of QEMU and only available when 2350compiled and linked against libiscsi. 2351ETEXI 2352DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 2353 "-iscsi [user=user][,password=password]\n" 2354 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 2355 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2356 " [,timeout=timeout]\n" 2357 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2358STEXI 2359 2360iSCSI parameters such as username and password can also be specified via 2361a configuration file. See qemu-doc for more information and examples. 2362 2363@item NBD 2364QEMU supports NBD (Network Block Devices) both using TCP protocol as well 2365as Unix Domain Sockets. 2366 2367Syntax for specifying a NBD device using TCP 2368``nbd:<server-ip>:<port>[:exportname=<export>]'' 2369 2370Syntax for specifying a NBD device using Unix Domain Sockets 2371``nbd:unix:<domain-socket>[:exportname=<export>]'' 2372 2373 2374Example for TCP 2375@example 2376qemu-system-i386 --drive file=nbd:192.0.2.1:30000 2377@end example 2378 2379Example for Unix Domain Sockets 2380@example 2381qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket 2382@end example 2383 2384@item SSH 2385QEMU supports SSH (Secure Shell) access to remote disks. 2386 2387Examples: 2388@example 2389qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img 2390qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img 2391@end example 2392 2393Currently authentication must be done using ssh-agent. Other 2394authentication methods may be supported in future. 2395 2396@item Sheepdog 2397Sheepdog is a distributed storage system for QEMU. 2398QEMU supports using either local sheepdog devices or remote networked 2399devices. 2400 2401Syntax for specifying a sheepdog device 2402@example 2403sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag] 2404@end example 2405 2406Example 2407@example 2408qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine 2409@end example 2410 2411See also @url{http://http://www.osrg.net/sheepdog/}. 2412 2413@item GlusterFS 2414GlusterFS is an user space distributed file system. 2415QEMU supports the use of GlusterFS volumes for hosting VM disk images using 2416TCP, Unix Domain Sockets and RDMA transport protocols. 2417 2418Syntax for specifying a VM disk image on GlusterFS volume is 2419@example 2420gluster[+transport]://[server[:port]]/volname/image[?socket=...] 2421@end example 2422 2423 2424Example 2425@example 2426qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img 2427@end example 2428 2429See also @url{http://www.gluster.org}. 2430 2431@item HTTP/HTTPS/FTP/FTPS/TFTP 2432QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp. 2433 2434Syntax using a single filename: 2435@example 2436<protocol>://[<username>[:<password>]@@]<host>/<path> 2437@end example 2438 2439where: 2440@table @option 2441@item protocol 2442'http', 'https', 'ftp', 'ftps', or 'tftp'. 2443 2444@item username 2445Optional username for authentication to the remote server. 2446 2447@item password 2448Optional password for authentication to the remote server. 2449 2450@item host 2451Address of the remote server. 2452 2453@item path 2454Path on the remote server, including any query string. 2455@end table 2456 2457The following options are also supported: 2458@table @option 2459@item url 2460The full URL when passing options to the driver explicitly. 2461 2462@item readahead 2463The amount of data to read ahead with each range request to the remote server. 2464This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it 2465does not have a suffix, it will be assumed to be in bytes. The value must be a 2466multiple of 512 bytes. It defaults to 256k. 2467 2468@item sslverify 2469Whether to verify the remote server's certificate when connecting over SSL. It 2470can have the value 'on' or 'off'. It defaults to 'on'. 2471 2472@item cookie 2473Send this cookie (it can also be a list of cookies separated by ';') with 2474each outgoing request. Only supported when using protocols such as HTTP 2475which support cookies, otherwise ignored. 2476 2477@item timeout 2478Set the timeout in seconds of the CURL connection. This timeout is the time 2479that CURL waits for a response from the remote server to get the size of the 2480image to be downloaded. If not set, the default timeout of 5 seconds is used. 2481@end table 2482 2483Note that when passing options to qemu explicitly, @option{driver} is the value 2484of <protocol>. 2485 2486Example: boot from a remote Fedora 20 live ISO image 2487@example 2488qemu-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 2489 2490qemu-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 2491@end example 2492 2493Example: boot from a remote Fedora 20 cloud image using a local overlay for 2494writes, copy-on-read, and a readahead of 64k 2495@example 2496qemu-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 2497 2498qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on 2499@end example 2500 2501Example: boot from an image stored on a VMware vSphere server with a self-signed 2502certificate using a local overlay for writes, a readahead of 64k and a timeout 2503of 10 seconds. 2504@example 2505qemu-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 2506 2507qemu-system-x86_64 -drive file=/tmp/test.qcow2 2508@end example 2509ETEXI 2510 2511STEXI 2512@end table 2513ETEXI 2514 2515DEFHEADING(Bluetooth(R) options:) 2516STEXI 2517@table @option 2518ETEXI 2519 2520DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 2521 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 2522 "-bt hci,host[:id]\n" \ 2523 " use host's HCI with the given name\n" \ 2524 "-bt hci[,vlan=n]\n" \ 2525 " emulate a standard HCI in virtual scatternet 'n'\n" \ 2526 "-bt vhci[,vlan=n]\n" \ 2527 " add host computer to virtual scatternet 'n' using VHCI\n" \ 2528 "-bt device:dev[,vlan=n]\n" \ 2529 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 2530 QEMU_ARCH_ALL) 2531STEXI 2532@item -bt hci[...] 2533@findex -bt 2534Defines the function of the corresponding Bluetooth HCI. -bt options 2535are matched with the HCIs present in the chosen machine type. For 2536example when emulating a machine with only one HCI built into it, only 2537the first @code{-bt hci[...]} option is valid and defines the HCI's 2538logic. The Transport Layer is decided by the machine type. Currently 2539the machines @code{n800} and @code{n810} have one HCI and all other 2540machines have none. 2541 2542@anchor{bt-hcis} 2543The following three types are recognized: 2544 2545@table @option 2546@item -bt hci,null 2547(default) The corresponding Bluetooth HCI assumes no internal logic 2548and will not respond to any HCI commands or emit events. 2549 2550@item -bt hci,host[:@var{id}] 2551(@code{bluez} only) The corresponding HCI passes commands / events 2552to / from the physical HCI identified by the name @var{id} (default: 2553@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 2554capable systems like Linux. 2555 2556@item -bt hci[,vlan=@var{n}] 2557Add a virtual, standard HCI that will participate in the Bluetooth 2558scatternet @var{n} (default @code{0}). Similarly to @option{-net} 2559VLANs, devices inside a bluetooth network @var{n} can only communicate 2560with other devices in the same network (scatternet). 2561@end table 2562 2563@item -bt vhci[,vlan=@var{n}] 2564(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 2565to the host bluetooth stack instead of to the emulated target. This 2566allows the host and target machines to participate in a common scatternet 2567and communicate. Requires the Linux @code{vhci} driver installed. Can 2568be used as following: 2569 2570@example 2571qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 2572@end example 2573 2574@item -bt device:@var{dev}[,vlan=@var{n}] 2575Emulate a bluetooth device @var{dev} and place it in network @var{n} 2576(default @code{0}). QEMU can only emulate one type of bluetooth devices 2577currently: 2578 2579@table @option 2580@item keyboard 2581Virtual wireless keyboard implementing the HIDP bluetooth profile. 2582@end table 2583ETEXI 2584 2585STEXI 2586@end table 2587ETEXI 2588DEFHEADING() 2589 2590#ifdef CONFIG_TPM 2591DEFHEADING(TPM device options:) 2592 2593DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 2594 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 2595 " use path to provide path to a character device; default is /dev/tpm0\n" 2596 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 2597 " not provided it will be searched for in /sys/class/misc/tpm?/device\n", 2598 QEMU_ARCH_ALL) 2599STEXI 2600 2601The general form of a TPM device option is: 2602@table @option 2603 2604@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] 2605@findex -tpmdev 2606Backend type must be: 2607@option{passthrough}. 2608 2609The specific backend type will determine the applicable options. 2610The @code{-tpmdev} option creates the TPM backend and requires a 2611@code{-device} option that specifies the TPM frontend interface model. 2612 2613Options to each backend are described below. 2614 2615Use 'help' to print all available TPM backend types. 2616@example 2617qemu -tpmdev help 2618@end example 2619 2620@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path} 2621 2622(Linux-host only) Enable access to the host's TPM using the passthrough 2623driver. 2624 2625@option{path} specifies the path to the host's TPM device, i.e., on 2626a Linux host this would be @code{/dev/tpm0}. 2627@option{path} is optional and by default @code{/dev/tpm0} is used. 2628 2629@option{cancel-path} specifies the path to the host TPM device's sysfs 2630entry allowing for cancellation of an ongoing TPM command. 2631@option{cancel-path} is optional and by default QEMU will search for the 2632sysfs entry to use. 2633 2634Some notes about using the host's TPM with the passthrough driver: 2635 2636The TPM device accessed by the passthrough driver must not be 2637used by any other application on the host. 2638 2639Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 2640the VM's firmware (BIOS/UEFI) will not be able to initialize the 2641TPM again and may therefore not show a TPM-specific menu that would 2642otherwise allow the user to configure the TPM, e.g., allow the user to 2643enable/disable or activate/deactivate the TPM. 2644Further, if TPM ownership is released from within a VM then the host's TPM 2645will get disabled and deactivated. To enable and activate the 2646TPM again afterwards, the host has to be rebooted and the user is 2647required to enter the firmware's menu to enable and activate the TPM. 2648If the TPM is left disabled and/or deactivated most TPM commands will fail. 2649 2650To create a passthrough TPM use the following two options: 2651@example 2652-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 2653@end example 2654Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 2655@code{tpmdev=tpm0} in the device option. 2656 2657@end table 2658 2659ETEXI 2660 2661DEFHEADING() 2662 2663#endif 2664 2665DEFHEADING(Linux/Multiboot boot specific:) 2666STEXI 2667 2668When using these options, you can use a given Linux or Multiboot 2669kernel without installing it in the disk image. It can be useful 2670for easier testing of various kernels. 2671 2672@table @option 2673ETEXI 2674 2675DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 2676 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 2677STEXI 2678@item -kernel @var{bzImage} 2679@findex -kernel 2680Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 2681or in multiboot format. 2682ETEXI 2683 2684DEF("append", HAS_ARG, QEMU_OPTION_append, \ 2685 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 2686STEXI 2687@item -append @var{cmdline} 2688@findex -append 2689Use @var{cmdline} as kernel command line 2690ETEXI 2691 2692DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 2693 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 2694STEXI 2695@item -initrd @var{file} 2696@findex -initrd 2697Use @var{file} as initial ram disk. 2698 2699@item -initrd "@var{file1} arg=foo,@var{file2}" 2700 2701This syntax is only available with multiboot. 2702 2703Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 2704first module. 2705ETEXI 2706 2707DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 2708 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 2709STEXI 2710@item -dtb @var{file} 2711@findex -dtb 2712Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 2713on boot. 2714ETEXI 2715 2716STEXI 2717@end table 2718ETEXI 2719DEFHEADING() 2720 2721DEFHEADING(Debug/Expert options:) 2722STEXI 2723@table @option 2724ETEXI 2725 2726DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 2727 "-fw_cfg [name=]<name>,file=<file>\n" 2728 " add named fw_cfg entry from file\n" 2729 "-fw_cfg [name=]<name>,string=<str>\n" 2730 " add named fw_cfg entry from string\n", 2731 QEMU_ARCH_ALL) 2732STEXI 2733@item -fw_cfg [name=]@var{name},file=@var{file} 2734@findex -fw_cfg 2735Add named fw_cfg entry from file. @var{name} determines the name of 2736the entry in the fw_cfg file directory exposed to the guest. 2737 2738@item -fw_cfg [name=]@var{name},string=@var{str} 2739Add named fw_cfg entry from string. 2740ETEXI 2741 2742DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 2743 "-serial dev redirect the serial port to char device 'dev'\n", 2744 QEMU_ARCH_ALL) 2745STEXI 2746@item -serial @var{dev} 2747@findex -serial 2748Redirect the virtual serial port to host character device 2749@var{dev}. The default device is @code{vc} in graphical mode and 2750@code{stdio} in non graphical mode. 2751 2752This option can be used several times to simulate up to 4 serial 2753ports. 2754 2755Use @code{-serial none} to disable all serial ports. 2756 2757Available character devices are: 2758@table @option 2759@item vc[:@var{W}x@var{H}] 2760Virtual console. Optionally, a width and height can be given in pixel with 2761@example 2762vc:800x600 2763@end example 2764It is also possible to specify width or height in characters: 2765@example 2766vc:80Cx24C 2767@end example 2768@item pty 2769[Linux only] Pseudo TTY (a new PTY is automatically allocated) 2770@item none 2771No device is allocated. 2772@item null 2773void device 2774@item chardev:@var{id} 2775Use a named character device defined with the @code{-chardev} option. 2776@item /dev/XXX 2777[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 2778parameters are set according to the emulated ones. 2779@item /dev/parport@var{N} 2780[Linux only, parallel port only] Use host parallel port 2781@var{N}. Currently SPP and EPP parallel port features can be used. 2782@item file:@var{filename} 2783Write output to @var{filename}. No character can be read. 2784@item stdio 2785[Unix only] standard input/output 2786@item pipe:@var{filename} 2787name pipe @var{filename} 2788@item COM@var{n} 2789[Windows only] Use host serial port @var{n} 2790@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 2791This implements UDP Net Console. 2792When @var{remote_host} or @var{src_ip} are not specified 2793they default to @code{0.0.0.0}. 2794When not using a specified @var{src_port} a random port is automatically chosen. 2795 2796If you just want a simple readonly console you can use @code{netcat} or 2797@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 2798@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 2799will appear in the netconsole session. 2800 2801If you plan to send characters back via netconsole or you want to stop 2802and start QEMU a lot of times, you should have QEMU use the same 2803source port each time by using something like @code{-serial 2804udp::4555@@:4556} to QEMU. Another approach is to use a patched 2805version of netcat which can listen to a TCP port and send and receive 2806characters via udp. If you have a patched version of netcat which 2807activates telnet remote echo and single char transfer, then you can 2808use the following options to step up a netcat redirector to allow 2809telnet on port 5555 to access the QEMU port. 2810@table @code 2811@item QEMU Options: 2812-serial udp::4555@@:4556 2813@item netcat options: 2814-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 2815@item telnet options: 2816localhost 5555 2817@end table 2818 2819@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 2820The TCP Net Console has two modes of operation. It can send the serial 2821I/O to a location or wait for a connection from a location. By default 2822the TCP Net Console is sent to @var{host} at the @var{port}. If you use 2823the @var{server} option QEMU will wait for a client socket application 2824to connect to the port before continuing, unless the @code{nowait} 2825option was specified. The @code{nodelay} option disables the Nagle buffering 2826algorithm. The @code{reconnect} option only applies if @var{noserver} is 2827set, if the connection goes down it will attempt to reconnect at the 2828given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 2829one TCP connection at a time is accepted. You can use @code{telnet} to 2830connect to the corresponding character device. 2831@table @code 2832@item Example to send tcp console to 192.168.0.2 port 4444 2833-serial tcp:192.168.0.2:4444 2834@item Example to listen and wait on port 4444 for connection 2835-serial tcp::4444,server 2836@item Example to not wait and listen on ip 192.168.0.100 port 4444 2837-serial tcp:192.168.0.100:4444,server,nowait 2838@end table 2839 2840@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 2841The telnet protocol is used instead of raw tcp sockets. The options 2842work the same as if you had specified @code{-serial tcp}. The 2843difference is that the port acts like a telnet server or client using 2844telnet option negotiation. This will also allow you to send the 2845MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 2846sequence. Typically in unix telnet you do it with Control-] and then 2847type "send break" followed by pressing the enter key. 2848 2849@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 2850A unix domain socket is used instead of a tcp socket. The option works the 2851same as if you had specified @code{-serial tcp} except the unix domain socket 2852@var{path} is used for connections. 2853 2854@item mon:@var{dev_string} 2855This is a special option to allow the monitor to be multiplexed onto 2856another serial port. The monitor is accessed with key sequence of 2857@key{Control-a} and then pressing @key{c}. 2858@var{dev_string} should be any one of the serial devices specified 2859above. An example to multiplex the monitor onto a telnet server 2860listening on port 4444 would be: 2861@table @code 2862@item -serial mon:telnet::4444,server,nowait 2863@end table 2864When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 2865QEMU any more but will be passed to the guest instead. 2866 2867@item braille 2868Braille device. This will use BrlAPI to display the braille output on a real 2869or fake device. 2870 2871@item msmouse 2872Three button serial mouse. Configure the guest to use Microsoft protocol. 2873@end table 2874ETEXI 2875 2876DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 2877 "-parallel dev redirect the parallel port to char device 'dev'\n", 2878 QEMU_ARCH_ALL) 2879STEXI 2880@item -parallel @var{dev} 2881@findex -parallel 2882Redirect the virtual parallel port to host device @var{dev} (same 2883devices as the serial port). On Linux hosts, @file{/dev/parportN} can 2884be used to use hardware devices connected on the corresponding host 2885parallel port. 2886 2887This option can be used several times to simulate up to 3 parallel 2888ports. 2889 2890Use @code{-parallel none} to disable all parallel ports. 2891ETEXI 2892 2893DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 2894 "-monitor dev redirect the monitor to char device 'dev'\n", 2895 QEMU_ARCH_ALL) 2896STEXI 2897@item -monitor @var{dev} 2898@findex -monitor 2899Redirect the monitor to host device @var{dev} (same devices as the 2900serial port). 2901The default device is @code{vc} in graphical mode and @code{stdio} in 2902non graphical mode. 2903Use @code{-monitor none} to disable the default monitor. 2904ETEXI 2905DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 2906 "-qmp dev like -monitor but opens in 'control' mode\n", 2907 QEMU_ARCH_ALL) 2908STEXI 2909@item -qmp @var{dev} 2910@findex -qmp 2911Like -monitor but opens in 'control' mode. 2912ETEXI 2913DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 2914 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 2915 QEMU_ARCH_ALL) 2916STEXI 2917@item -qmp-pretty @var{dev} 2918@findex -qmp-pretty 2919Like -qmp but uses pretty JSON formatting. 2920ETEXI 2921 2922DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 2923 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL) 2924STEXI 2925@item -mon [chardev=]name[,mode=readline|control][,default] 2926@findex -mon 2927Setup monitor on chardev @var{name}. 2928ETEXI 2929 2930DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 2931 "-debugcon dev redirect the debug console to char device 'dev'\n", 2932 QEMU_ARCH_ALL) 2933STEXI 2934@item -debugcon @var{dev} 2935@findex -debugcon 2936Redirect the debug console to host device @var{dev} (same devices as the 2937serial port). The debug console is an I/O port which is typically port 29380xe9; writing to that I/O port sends output to this device. 2939The default device is @code{vc} in graphical mode and @code{stdio} in 2940non graphical mode. 2941ETEXI 2942 2943DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 2944 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 2945STEXI 2946@item -pidfile @var{file} 2947@findex -pidfile 2948Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 2949from a script. 2950ETEXI 2951 2952DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 2953 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 2954STEXI 2955@item -singlestep 2956@findex -singlestep 2957Run the emulation in single step mode. 2958ETEXI 2959 2960DEF("S", 0, QEMU_OPTION_S, \ 2961 "-S freeze CPU at startup (use 'c' to start execution)\n", 2962 QEMU_ARCH_ALL) 2963STEXI 2964@item -S 2965@findex -S 2966Do not start CPU at startup (you must type 'c' in the monitor). 2967ETEXI 2968 2969DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 2970 "-realtime [mlock=on|off]\n" 2971 " run qemu with realtime features\n" 2972 " mlock=on|off controls mlock support (default: on)\n", 2973 QEMU_ARCH_ALL) 2974STEXI 2975@item -realtime mlock=on|off 2976@findex -realtime 2977Run qemu with realtime features. 2978mlocking qemu and guest memory can be enabled via @option{mlock=on} 2979(enabled by default). 2980ETEXI 2981 2982DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 2983 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 2984STEXI 2985@item -gdb @var{dev} 2986@findex -gdb 2987Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 2988connections will likely be TCP-based, but also UDP, pseudo TTY, or even 2989stdio are reasonable use case. The latter is allowing to start QEMU from 2990within gdb and establish the connection via a pipe: 2991@example 2992(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 2993@end example 2994ETEXI 2995 2996DEF("s", 0, QEMU_OPTION_s, \ 2997 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 2998 QEMU_ARCH_ALL) 2999STEXI 3000@item -s 3001@findex -s 3002Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3003(@pxref{gdb_usage}). 3004ETEXI 3005 3006DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3007 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3008 QEMU_ARCH_ALL) 3009STEXI 3010@item -d @var{item1}[,...] 3011@findex -d 3012Enable logging of specified items. Use '-d help' for a list of log items. 3013ETEXI 3014 3015DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3016 "-D logfile output log to logfile (default stderr)\n", 3017 QEMU_ARCH_ALL) 3018STEXI 3019@item -D @var{logfile} 3020@findex -D 3021Output log in @var{logfile} instead of to stderr 3022ETEXI 3023 3024DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3025 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3026 QEMU_ARCH_ALL) 3027STEXI 3028@item -L @var{path} 3029@findex -L 3030Set the directory for the BIOS, VGA BIOS and keymaps. 3031ETEXI 3032 3033DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3034 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3035STEXI 3036@item -bios @var{file} 3037@findex -bios 3038Set the filename for the BIOS. 3039ETEXI 3040 3041DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3042 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3043STEXI 3044@item -enable-kvm 3045@findex -enable-kvm 3046Enable KVM full virtualization support. This option is only available 3047if KVM support is enabled when compiling. 3048ETEXI 3049 3050DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3051 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3052DEF("xen-create", 0, QEMU_OPTION_xen_create, 3053 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3054 " warning: should not be used when xend is in use\n", 3055 QEMU_ARCH_ALL) 3056DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3057 "-xen-attach attach to existing xen domain\n" 3058 " xend will use this when starting QEMU\n", 3059 QEMU_ARCH_ALL) 3060STEXI 3061@item -xen-domid @var{id} 3062@findex -xen-domid 3063Specify xen guest domain @var{id} (XEN only). 3064@item -xen-create 3065@findex -xen-create 3066Create domain using xen hypercalls, bypassing xend. 3067Warning: should not be used when xend is in use (XEN only). 3068@item -xen-attach 3069@findex -xen-attach 3070Attach to existing xen domain. 3071xend will use this when starting QEMU (XEN only). 3072ETEXI 3073 3074DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3075 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3076STEXI 3077@item -no-reboot 3078@findex -no-reboot 3079Exit instead of rebooting. 3080ETEXI 3081 3082DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3083 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3084STEXI 3085@item -no-shutdown 3086@findex -no-shutdown 3087Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3088This allows for instance switching to monitor to commit changes to the 3089disk image. 3090ETEXI 3091 3092DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3093 "-loadvm [tag|id]\n" \ 3094 " start right away with a saved state (loadvm in monitor)\n", 3095 QEMU_ARCH_ALL) 3096STEXI 3097@item -loadvm @var{file} 3098@findex -loadvm 3099Start right away with a saved state (@code{loadvm} in monitor) 3100ETEXI 3101 3102#ifndef _WIN32 3103DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3104 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3105#endif 3106STEXI 3107@item -daemonize 3108@findex -daemonize 3109Daemonize the QEMU process after initialization. QEMU will not detach from 3110standard IO until it is ready to receive connections on any of its devices. 3111This option is a useful way for external programs to launch QEMU without having 3112to cope with initialization race conditions. 3113ETEXI 3114 3115DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3116 "-option-rom rom load a file, rom, into the option ROM space\n", 3117 QEMU_ARCH_ALL) 3118STEXI 3119@item -option-rom @var{file} 3120@findex -option-rom 3121Load the contents of @var{file} as an option ROM. 3122This option is useful to load things like EtherBoot. 3123ETEXI 3124 3125HXCOMM Silently ignored for compatibility 3126DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3127 3128HXCOMM Options deprecated by -rtc 3129DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3130DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3131 3132DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3133 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3134 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3135 QEMU_ARCH_ALL) 3136 3137STEXI 3138 3139@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3140@findex -rtc 3141Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3142UTC or local time, respectively. @code{localtime} is required for correct date in 3143MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3144format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3145 3146By default the RTC is driven by the host system time. This allows using of the 3147RTC as accurate reference clock inside the guest, specifically if the host 3148time is smoothly following an accurate external reference clock, e.g. via NTP. 3149If you want to isolate the guest time from the host, you can set @option{clock} 3150to @code{rt} instead. To even prevent it from progressing during suspension, 3151you can set it to @code{vm}. 3152 3153Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3154specifically with Windows' ACPI HAL. This option will try to figure out how 3155many timer interrupts were not processed by the Windows guest and will 3156re-inject them. 3157ETEXI 3158 3159DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3160 "-icount [shift=N|auto][,align=on|off][,sleep=no]\n" \ 3161 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3162 " instruction, enable aligning the host and virtual clocks\n" \ 3163 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3164STEXI 3165@item -icount [shift=@var{N}|auto] 3166@findex -icount 3167Enable virtual instruction counter. The virtual cpu will execute one 3168instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3169then the virtual cpu speed will be automatically adjusted to keep virtual 3170time within a few seconds of real time. 3171 3172When the virtual cpu is sleeping, the virtual time will advance at default 3173speed unless @option{sleep=no} is specified. 3174With @option{sleep=no}, the virtual time will jump to the next timer deadline 3175instantly whenever the virtual cpu goes to sleep mode and will not advance 3176if no timer is enabled. This behavior give deterministic execution times from 3177the guest point of view. 3178 3179Note that while this option can give deterministic behavior, it does not 3180provide cycle accurate emulation. Modern CPUs contain superscalar out of 3181order cores with complex cache hierarchies. The number of instructions 3182executed often has little or no correlation with actual performance. 3183 3184@option{align=on} will activate the delay algorithm which will try 3185to synchronise the host clock and the virtual clock. The goal is to 3186have a guest running at the real frequency imposed by the shift option. 3187Whenever the guest clock is behind the host clock and if 3188@option{align=on} is specified then we print a message to the user 3189to inform about the delay. 3190Currently this option does not work when @option{shift} is @code{auto}. 3191Note: The sync algorithm will work for those shift values for which 3192the guest clock runs ahead of the host clock. Typically this happens 3193when the shift value is high (how high depends on the host machine). 3194ETEXI 3195 3196DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3197 "-watchdog model\n" \ 3198 " enable virtual hardware watchdog [default=none]\n", 3199 QEMU_ARCH_ALL) 3200STEXI 3201@item -watchdog @var{model} 3202@findex -watchdog 3203Create a virtual hardware watchdog device. Once enabled (by a guest 3204action), the watchdog must be periodically polled by an agent inside 3205the guest or else the guest will be restarted. Choose a model for 3206which your guest has drivers. 3207 3208The @var{model} is the model of hardware watchdog to emulate. Use 3209@code{-watchdog help} to list available hardware models. Only one 3210watchdog can be enabled for a guest. 3211 3212The following models may be available: 3213@table @option 3214@item ib700 3215iBASE 700 is a very simple ISA watchdog with a single timer. 3216@item i6300esb 3217Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3218dual-timer watchdog. 3219@item diag288 3220A virtual watchdog for s390x backed by the diagnose 288 hypercall 3221(currently KVM only). 3222@end table 3223ETEXI 3224 3225DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3226 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \ 3227 " action when watchdog fires [default=reset]\n", 3228 QEMU_ARCH_ALL) 3229STEXI 3230@item -watchdog-action @var{action} 3231@findex -watchdog-action 3232 3233The @var{action} controls what QEMU will do when the watchdog timer 3234expires. 3235The default is 3236@code{reset} (forcefully reset the guest). 3237Other possible actions are: 3238@code{shutdown} (attempt to gracefully shutdown the guest), 3239@code{poweroff} (forcefully poweroff the guest), 3240@code{pause} (pause the guest), 3241@code{debug} (print a debug message and continue), or 3242@code{none} (do nothing). 3243 3244Note that the @code{shutdown} action requires that the guest responds 3245to ACPI signals, which it may not be able to do in the sort of 3246situations where the watchdog would have expired, and thus 3247@code{-watchdog-action shutdown} is not recommended for production use. 3248 3249Examples: 3250 3251@table @code 3252@item -watchdog i6300esb -watchdog-action pause 3253@itemx -watchdog ib700 3254@end table 3255ETEXI 3256 3257DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3258 "-echr chr set terminal escape character instead of ctrl-a\n", 3259 QEMU_ARCH_ALL) 3260STEXI 3261 3262@item -echr @var{numeric_ascii_value} 3263@findex -echr 3264Change the escape character used for switching to the monitor when using 3265monitor and serial sharing. The default is @code{0x01} when using the 3266@code{-nographic} option. @code{0x01} is equal to pressing 3267@code{Control-a}. You can select a different character from the ascii 3268control keys where 1 through 26 map to Control-a through Control-z. For 3269instance you could use the either of the following to change the escape 3270character to Control-t. 3271@table @code 3272@item -echr 0x14 3273@itemx -echr 20 3274@end table 3275ETEXI 3276 3277DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3278 "-virtioconsole c\n" \ 3279 " set virtio console\n", QEMU_ARCH_ALL) 3280STEXI 3281@item -virtioconsole @var{c} 3282@findex -virtioconsole 3283Set virtio console. 3284 3285This option is maintained for backward compatibility. 3286 3287Please use @code{-device virtconsole} for the new way of invocation. 3288ETEXI 3289 3290DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3291 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3292STEXI 3293@item -show-cursor 3294@findex -show-cursor 3295Show cursor. 3296ETEXI 3297 3298DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3299 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3300STEXI 3301@item -tb-size @var{n} 3302@findex -tb-size 3303Set TB size. 3304ETEXI 3305 3306DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3307 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3308 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3309 "-incoming unix:socketpath\n" \ 3310 " prepare for incoming migration, listen on\n" \ 3311 " specified protocol and socket address\n" \ 3312 "-incoming fd:fd\n" \ 3313 "-incoming exec:cmdline\n" \ 3314 " accept incoming migration on given file descriptor\n" \ 3315 " or from given external command\n" \ 3316 "-incoming defer\n" \ 3317 " wait for the URI to be specified via migrate_incoming\n", 3318 QEMU_ARCH_ALL) 3319STEXI 3320@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3321@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3322@findex -incoming 3323Prepare for incoming migration, listen on a given tcp port. 3324 3325@item -incoming unix:@var{socketpath} 3326Prepare for incoming migration, listen on a given unix socket. 3327 3328@item -incoming fd:@var{fd} 3329Accept incoming migration from a given filedescriptor. 3330 3331@item -incoming exec:@var{cmdline} 3332Accept incoming migration as an output from specified external command. 3333 3334@item -incoming defer 3335Wait for the URI to be specified via migrate_incoming. The monitor can 3336be used to change settings (such as migration parameters) prior to issuing 3337the migrate_incoming to allow the migration to begin. 3338ETEXI 3339 3340DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3341 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3342STEXI 3343@item -nodefaults 3344@findex -nodefaults 3345Don't create default devices. Normally, QEMU sets the default devices like serial 3346port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3347CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3348default devices. 3349ETEXI 3350 3351#ifndef _WIN32 3352DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3353 "-chroot dir chroot to dir just before starting the VM\n", 3354 QEMU_ARCH_ALL) 3355#endif 3356STEXI 3357@item -chroot @var{dir} 3358@findex -chroot 3359Immediately before starting guest execution, chroot to the specified 3360directory. Especially useful in combination with -runas. 3361ETEXI 3362 3363#ifndef _WIN32 3364DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3365 "-runas user change to user id user just before starting the VM\n", 3366 QEMU_ARCH_ALL) 3367#endif 3368STEXI 3369@item -runas @var{user} 3370@findex -runas 3371Immediately before starting guest execution, drop root privileges, switching 3372to the specified user. 3373ETEXI 3374 3375DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3376 "-prom-env variable=value\n" 3377 " set OpenBIOS nvram variables\n", 3378 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3379STEXI 3380@item -prom-env @var{variable}=@var{value} 3381@findex -prom-env 3382Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3383ETEXI 3384DEF("semihosting", 0, QEMU_OPTION_semihosting, 3385 "-semihosting semihosting mode\n", 3386 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3387 QEMU_ARCH_MIPS) 3388STEXI 3389@item -semihosting 3390@findex -semihosting 3391Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 3392ETEXI 3393DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 3394 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 3395 " semihosting configuration\n", 3396QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3397QEMU_ARCH_MIPS) 3398STEXI 3399@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 3400@findex -semihosting-config 3401Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 3402@table @option 3403@item target=@code{native|gdb|auto} 3404Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 3405or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 3406during debug sessions and @code{native} otherwise. 3407@item arg=@var{str1},arg=@var{str2},... 3408Allows the user to pass input arguments, and can be used multiple times to build 3409up a list. The old-style @code{-kernel}/@code{-append} method of passing a 3410command line is still supported for backward compatibility. If both the 3411@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 3412specified, the former is passed to semihosting as it always takes precedence. 3413@end table 3414ETEXI 3415DEF("old-param", 0, QEMU_OPTION_old_param, 3416 "-old-param old param mode\n", QEMU_ARCH_ARM) 3417STEXI 3418@item -old-param 3419@findex -old-param (ARM) 3420Old param mode (ARM only). 3421ETEXI 3422 3423DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 3424 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", 3425 QEMU_ARCH_ALL) 3426STEXI 3427@item -sandbox @var{arg} 3428@findex -sandbox 3429Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 3430disable it. The default is 'off'. 3431ETEXI 3432 3433DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 3434 "-readconfig <file>\n", QEMU_ARCH_ALL) 3435STEXI 3436@item -readconfig @var{file} 3437@findex -readconfig 3438Read device configuration from @var{file}. This approach is useful when you want to spawn 3439QEMU process with many command line options but you don't want to exceed the command line 3440character limit. 3441ETEXI 3442DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 3443 "-writeconfig <file>\n" 3444 " read/write config file\n", QEMU_ARCH_ALL) 3445STEXI 3446@item -writeconfig @var{file} 3447@findex -writeconfig 3448Write device configuration to @var{file}. The @var{file} can be either filename to save 3449command line and device configuration into file or dash @code{-}) character to print the 3450output to stdout. This can be later used as input file for @code{-readconfig} option. 3451ETEXI 3452DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, 3453 "-nodefconfig\n" 3454 " do not load default config files at startup\n", 3455 QEMU_ARCH_ALL) 3456STEXI 3457@item -nodefconfig 3458@findex -nodefconfig 3459Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup. 3460The @code{-nodefconfig} option will prevent QEMU from loading any of those config files. 3461ETEXI 3462DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 3463 "-no-user-config\n" 3464 " do not load user-provided config files at startup\n", 3465 QEMU_ARCH_ALL) 3466STEXI 3467@item -no-user-config 3468@findex -no-user-config 3469The @code{-no-user-config} option makes QEMU not load any of the user-provided 3470config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config 3471files from @var{datadir}. 3472ETEXI 3473DEF("trace", HAS_ARG, QEMU_OPTION_trace, 3474 "-trace [events=<file>][,file=<file>]\n" 3475 " specify tracing options\n", 3476 QEMU_ARCH_ALL) 3477STEXI 3478HXCOMM This line is not accurate, as some sub-options are backend-specific but 3479HXCOMM HX does not support conditional compilation of text. 3480@item -trace [events=@var{file}][,file=@var{file}] 3481@findex -trace 3482 3483Specify tracing options. 3484 3485@table @option 3486@item events=@var{file} 3487Immediately enable events listed in @var{file}. 3488The file must contain one event name (as listed in the @var{trace-events} file) 3489per line. 3490This option is only available if QEMU has been compiled with 3491either @var{simple} or @var{stderr} tracing backend. 3492@item file=@var{file} 3493Log output traces to @var{file}. 3494 3495This option is only available if QEMU has been compiled with 3496the @var{simple} tracing backend. 3497@end table 3498ETEXI 3499 3500HXCOMM Internal use 3501DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 3502DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 3503 3504#ifdef __linux__ 3505DEF("enable-fips", 0, QEMU_OPTION_enablefips, 3506 "-enable-fips enable FIPS 140-2 compliance\n", 3507 QEMU_ARCH_ALL) 3508#endif 3509STEXI 3510@item -enable-fips 3511@findex -enable-fips 3512Enable FIPS 140-2 compliance mode. 3513ETEXI 3514 3515HXCOMM Deprecated by -machine accel=tcg property 3516DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 3517 3518HXCOMM Deprecated by kvm-pit driver properties 3519DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, 3520 "", QEMU_ARCH_I386) 3521 3522HXCOMM Deprecated (ignored) 3523DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386) 3524 3525HXCOMM Deprecated by -machine kernel_irqchip=on|off property 3526DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386) 3527 3528HXCOMM Deprecated (ignored) 3529DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL) 3530 3531DEF("msg", HAS_ARG, QEMU_OPTION_msg, 3532 "-msg timestamp[=on|off]\n" 3533 " change the format of messages\n" 3534 " on|off controls leading timestamps (default:on)\n", 3535 QEMU_ARCH_ALL) 3536STEXI 3537@item -msg timestamp[=on|off] 3538@findex -msg 3539prepend a timestamp to each log message.(default:on) 3540ETEXI 3541 3542DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 3543 "-dump-vmstate <file>\n" 3544 " Output vmstate information in JSON format to file.\n" 3545 " Use the scripts/vmstate-static-checker.py file to\n" 3546 " check for possible regressions in migration code\n" 3547 " by comparing two such vmstate dumps.\n", 3548 QEMU_ARCH_ALL) 3549STEXI 3550@item -dump-vmstate @var{file} 3551@findex -dump-vmstate 3552Dump json-encoded vmstate information for current machine type to file 3553in @var{file} 3554ETEXI 3555 3556DEFHEADING(Generic object creation) 3557 3558DEF("object", HAS_ARG, QEMU_OPTION_object, 3559 "-object TYPENAME[,PROP1=VALUE1,...]\n" 3560 " create a new object of type TYPENAME setting properties\n" 3561 " in the order they are specified. Note that the 'id'\n" 3562 " property must be set. These objects are placed in the\n" 3563 " '/objects' path.\n", 3564 QEMU_ARCH_ALL) 3565STEXI 3566@item -object @var{typename}[,@var{prop1}=@var{value1},...] 3567@findex -object 3568Create a new object of type @var{typename} setting properties 3569in the order they are specified. Note that the 'id' 3570property must be set. These objects are placed in the 3571'/objects' path. 3572 3573@table @option 3574 3575@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off} 3576 3577Creates a memory file backend object, which can be used to back 3578the guest RAM with huge pages. The @option{id} parameter is a 3579unique ID that will be used to reference this memory region 3580when configuring the @option{-numa} argument. The @option{size} 3581option provides the size of the memory region, and accepts 3582common suffixes, eg @option{500M}. The @option{mem-path} provides 3583the path to either a shared memory or huge page filesystem mount. 3584The @option{share} boolean option determines whether the memory 3585region is marked as private to QEMU, or shared. The latter allows 3586a co-operating external process to access the QEMU memory region. 3587 3588@item -object rng-random,id=@var{id},filename=@var{/dev/random} 3589 3590Creates a random number generator backend which obtains entropy from 3591a device on the host. The @option{id} parameter is a unique ID that 3592will be used to reference this entropy backend from the @option{virtio-rng} 3593device. The @option{filename} parameter specifies which file to obtain 3594entropy from and if omitted defaults to @option{/dev/random}. 3595 3596@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 3597 3598Creates a random number generator backend which obtains entropy from 3599an external daemon running on the host. The @option{id} parameter is 3600a unique ID that will be used to reference this entropy backend from 3601the @option{virtio-rng} device. The @option{chardev} parameter is 3602the unique ID of a character device backend that provides the connection 3603to the RNG daemon. 3604 3605@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 3606 3607Creates a TLS anonymous credentials object, which can be used to provide 3608TLS support on network backends. The @option{id} parameter is a unique 3609ID which network backends will use to access the credentials. The 3610@option{endpoint} is either @option{server} or @option{client} depending 3611on whether the QEMU network backend that uses the credentials will be 3612acting as a client or as a server. If @option{verify-peer} is enabled 3613(the default) then once the handshake is completed, the peer credentials 3614will be verified, though this is a no-op for anonymous credentials. 3615 3616The @var{dir} parameter tells QEMU where to find the credential 3617files. For server endpoints, this directory may contain a file 3618@var{dh-params.pem} providing diffie-hellman parameters to use 3619for the TLS server. If the file is missing, QEMU will generate 3620a set of DH parameters at startup. This is a computationally 3621expensive operation that consumes random pool entropy, so it is 3622recommended that a persistent set of parameters be generated 3623upfront and saved. 3624 3625@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 3626 3627Creates a TLS anonymous credentials object, which can be used to provide 3628TLS support on network backends. The @option{id} parameter is a unique 3629ID which network backends will use to access the credentials. The 3630@option{endpoint} is either @option{server} or @option{client} depending 3631on whether the QEMU network backend that uses the credentials will be 3632acting as a client or as a server. If @option{verify-peer} is enabled 3633(the default) then once the handshake is completed, the peer credentials 3634will be verified. With x509 certificates, this implies that the clients 3635must be provided with valid client certificates too. 3636 3637The @var{dir} parameter tells QEMU where to find the credential 3638files. For server endpoints, this directory may contain a file 3639@var{dh-params.pem} providing diffie-hellman parameters to use 3640for the TLS server. If the file is missing, QEMU will generate 3641a set of DH parameters at startup. This is a computationally 3642expensive operation that consumes random pool entropy, so it is 3643recommended that a persistent set of parameters be generated 3644upfront and saved. 3645 3646For x509 certificate credentials the directory will contain further files 3647providing the x509 certificates. The certificates must be stored 3648in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 3649@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 3650@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 3651 3652@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}] 3653 3654Interval @var{t} can't be 0, this filter batches the packet delivery: all 3655packets arriving in a given interval on netdev @var{netdevid} are delayed 3656until the end of the interval. Interval is in microseconds. 3657 3658queue @var{all|rx|tx} is an option that can be applied to any netfilter. 3659 3660@option{all}: the filter is attached both to the receive and the transmit 3661 queue of the netdev (default). 3662 3663@option{rx}: the filter is attached to the receive queue of the netdev, 3664 where it will receive packets sent to the netdev. 3665 3666@option{tx}: the filter is attached to the transmit queue of the netdev, 3667 where it will receive packets sent by the netdev. 3668 3669@item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}] 3670 3671Dump the network traffic on netdev @var{dev} to the file specified by 3672@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 3673The file format is libpcap, so it can be analyzed with tools such as tcpdump 3674or Wireshark. 3675 3676@end table 3677 3678ETEXI 3679 3680 3681HXCOMM This is the last statement. Insert new options before this line! 3682STEXI 3683@end table 3684ETEXI 3685
