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 " kernel_irqchip=on|off|split controls accelerated irqchip support (default=off)\n" 37 " vmport=on|off|auto controls emulation of vmport (default: auto)\n" 38 " kvm_shadow_mem=size of KVM shadow MMU\n" 39 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n" 40 " mem-merge=on|off controls memory merge support (default: on)\n" 41 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n" 42 " igd-passthru=on|off controls IGD GFX passthrough support (default=off)\n" 43 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n" 44 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n" 45 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n", 46 QEMU_ARCH_ALL) 47STEXI 48@item -machine [type=]@var{name}[,prop=@var{value}[,...]] 49@findex -machine 50Select the emulated machine by @var{name}. Use @code{-machine help} to list 51available machines. Supported machine properties are: 52@table @option 53@item accel=@var{accels1}[:@var{accels2}[:...]] 54This is used to enable an accelerator. Depending on the target architecture, 55kvm, xen, or tcg can be available. By default, tcg is used. If there is more 56than one accelerator specified, the next one is used if the previous one fails 57to initialize. 58@item kernel_irqchip=on|off 59Controls in-kernel irqchip support for the chosen accelerator when available. 60@item gfx_passthru=on|off 61Enables IGD GFX passthrough support for the chosen machine when available. 62@item vmport=on|off|auto 63Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the 64value based on accel. For accel=xen the default is off otherwise the default 65is on. 66@item kvm_shadow_mem=size 67Defines the size of the KVM shadow MMU. 68@item dump-guest-core=on|off 69Include guest memory in a core dump. The default is on. 70@item mem-merge=on|off 71Enables or disables memory merge support. This feature, when supported by 72the host, de-duplicates identical memory pages among VMs instances 73(enabled by default). 74@item iommu=on|off 75Enables or disables emulated Intel IOMMU (VT-d) support. The default is off. 76@item aes-key-wrap=on|off 77Enables or disables AES key wrapping support on s390-ccw hosts. This feature 78controls whether AES wrapping keys will be created to allow 79execution of AES cryptographic functions. The default is on. 80@item dea-key-wrap=on|off 81Enables or disables DEA key wrapping support on s390-ccw hosts. This feature 82controls whether DEA wrapping keys will be created to allow 83execution of DEA cryptographic functions. The default is on. 84@end table 85ETEXI 86 87HXCOMM Deprecated by -machine 88DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL) 89 90DEF("cpu", HAS_ARG, QEMU_OPTION_cpu, 91 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL) 92STEXI 93@item -cpu @var{model} 94@findex -cpu 95Select CPU model (@code{-cpu help} for list and additional feature selection) 96ETEXI 97 98DEF("smp", HAS_ARG, QEMU_OPTION_smp, 99 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n" 100 " set the number of CPUs to 'n' [default=1]\n" 101 " maxcpus= maximum number of total cpus, including\n" 102 " offline CPUs for hotplug, etc\n" 103 " cores= number of CPU cores on one socket\n" 104 " threads= number of threads on one CPU core\n" 105 " sockets= number of discrete sockets in the system\n", 106 QEMU_ARCH_ALL) 107STEXI 108@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}] 109@findex -smp 110Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255 111CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs 112to 4. 113For the PC target, the number of @var{cores} per socket, the number 114of @var{threads} per cores and the total number of @var{sockets} can be 115specified. Missing values will be computed. If any on the three values is 116given, the total number of CPUs @var{n} can be omitted. @var{maxcpus} 117specifies the maximum number of hotpluggable CPUs. 118ETEXI 119 120DEF("numa", HAS_ARG, QEMU_OPTION_numa, 121 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n" 122 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL) 123STEXI 124@item -numa node[,mem=@var{size}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 125@itemx -numa node[,memdev=@var{id}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}] 126@findex -numa 127Simulate a multi node NUMA system. If @samp{mem}, @samp{memdev} 128and @samp{cpus} are omitted, resources are split equally. Also, note 129that the -@option{numa} option doesn't allocate any of the specified 130resources. That is, it just assigns existing resources to NUMA nodes. This 131means that one still has to use the @option{-m}, @option{-smp} options 132to allocate RAM and VCPUs respectively, and possibly @option{-object} 133to specify the memory backend for the @samp{memdev} suboption. 134 135@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one 136node uses @samp{memdev}, all of them have to use it. 137ETEXI 138 139DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd, 140 "-add-fd fd=fd,set=set[,opaque=opaque]\n" 141 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL) 142STEXI 143@item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}] 144@findex -add-fd 145 146Add a file descriptor to an fd set. Valid options are: 147 148@table @option 149@item fd=@var{fd} 150This option defines the file descriptor of which a duplicate is added to fd set. 151The file descriptor cannot be stdin, stdout, or stderr. 152@item set=@var{set} 153This option defines the ID of the fd set to add the file descriptor to. 154@item opaque=@var{opaque} 155This option defines a free-form string that can be used to describe @var{fd}. 156@end table 157 158You can open an image using pre-opened file descriptors from an fd set: 159@example 160qemu-system-i386 161-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 162-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 163-drive file=/dev/fdset/2,index=0,media=disk 164@end example 165ETEXI 166 167DEF("set", HAS_ARG, QEMU_OPTION_set, 168 "-set group.id.arg=value\n" 169 " set <arg> parameter for item <id> of type <group>\n" 170 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL) 171STEXI 172@item -set @var{group}.@var{id}.@var{arg}=@var{value} 173@findex -set 174Set parameter @var{arg} for item @var{id} of type @var{group}\n" 175ETEXI 176 177DEF("global", HAS_ARG, QEMU_OPTION_global, 178 "-global driver.property=value\n" 179 "-global driver=driver,property=property,value=value\n" 180 " set a global default for a driver property\n", 181 QEMU_ARCH_ALL) 182STEXI 183@item -global @var{driver}.@var{prop}=@var{value} 184@itemx -global driver=@var{driver},property=@var{property},value=@var{value} 185@findex -global 186Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.: 187 188@example 189qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk 190@end example 191 192In particular, you can use this to set driver properties for devices which are 193created automatically by the machine model. To create a device which is not 194created automatically and set properties on it, use -@option{device}. 195 196-global @var{driver}.@var{prop}=@var{value} is shorthand for -global 197driver=@var{driver},property=@var{prop},value=@var{value}. The 198longhand syntax works even when @var{driver} contains a dot. 199ETEXI 200 201DEF("boot", HAS_ARG, QEMU_OPTION_boot, 202 "-boot [order=drives][,once=drives][,menu=on|off]\n" 203 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n" 204 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n" 205 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n" 206 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n" 207 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n", 208 QEMU_ARCH_ALL) 209STEXI 210@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] 211@findex -boot 212Specify boot order @var{drives} as a string of drive letters. Valid 213drive letters depend on the target architecture. The x86 PC uses: a, b 214(floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot 215from network adapter 1-4), hard disk boot is the default. To apply a 216particular boot order only on the first startup, specify it via 217@option{once}. 218 219Interactive boot menus/prompts can be enabled via @option{menu=on} as far 220as firmware/BIOS supports them. The default is non-interactive boot. 221 222A splash picture could be passed to bios, enabling user to show it as logo, 223when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS 224supports them. Currently Seabios for X86 system support it. 225limitation: The splash file could be a jpeg file or a BMP file in 24 BPP 226format(true color). The resolution should be supported by the SVGA mode, so 227the recommended is 320x240, 640x480, 800x640. 228 229A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms 230when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not 231reboot, qemu passes '-1' to bios by default. Currently Seabios for X86 232system support it. 233 234Do strict boot via @option{strict=on} as far as firmware/BIOS 235supports it. This only effects when boot priority is changed by 236bootindex options. The default is non-strict boot. 237 238@example 239# try to boot from network first, then from hard disk 240qemu-system-i386 -boot order=nc 241# boot from CD-ROM first, switch back to default order after reboot 242qemu-system-i386 -boot once=d 243# boot with a splash picture for 5 seconds. 244qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000 245@end example 246 247Note: The legacy format '-boot @var{drives}' is still supported but its 248use is discouraged as it may be removed from future versions. 249ETEXI 250 251DEF("m", HAS_ARG, QEMU_OPTION_m, 252 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n" 253 " configure guest RAM\n" 254 " size: initial amount of guest memory\n" 255 " slots: number of hotplug slots (default: none)\n" 256 " maxmem: maximum amount of guest memory (default: none)\n" 257 "NOTE: Some architectures might enforce a specific granularity\n", 258 QEMU_ARCH_ALL) 259STEXI 260@item -m [size=]@var{megs}[,slots=n,maxmem=size] 261@findex -m 262Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB. 263Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in 264megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem} 265could be used to set amount of hotpluggable memory slots and maximum amount of 266memory. Note that @var{maxmem} must be aligned to the page size. 267 268For example, the following command-line sets the guest startup RAM size to 2691GB, creates 3 slots to hotplug additional memory and sets the maximum 270memory the guest can reach to 4GB: 271 272@example 273qemu-system-x86_64 -m 1G,slots=3,maxmem=4G 274@end example 275 276If @var{slots} and @var{maxmem} are not specified, memory hotplug won't 277be enabled and the guest startup RAM will never increase. 278ETEXI 279 280DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath, 281 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL) 282STEXI 283@item -mem-path @var{path} 284@findex -mem-path 285Allocate guest RAM from a temporarily created file in @var{path}. 286ETEXI 287 288DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, 289 "-mem-prealloc preallocate guest memory (use with -mem-path)\n", 290 QEMU_ARCH_ALL) 291STEXI 292@item -mem-prealloc 293@findex -mem-prealloc 294Preallocate memory when using -mem-path. 295ETEXI 296 297DEF("k", HAS_ARG, QEMU_OPTION_k, 298 "-k language use keyboard layout (for example 'fr' for French)\n", 299 QEMU_ARCH_ALL) 300STEXI 301@item -k @var{language} 302@findex -k 303Use keyboard layout @var{language} (for example @code{fr} for 304French). This option is only needed where it is not easy to get raw PC 305keycodes (e.g. on Macs, with some X11 servers or with a VNC 306display). You don't normally need to use it on PC/Linux or PC/Windows 307hosts. 308 309The available layouts are: 310@example 311ar de-ch es fo fr-ca hu ja mk no pt-br sv 312da en-gb et fr fr-ch is lt nl pl ru th 313de en-us fi fr-be hr it lv nl-be pt sl tr 314@end example 315 316The default is @code{en-us}. 317ETEXI 318 319 320DEF("audio-help", 0, QEMU_OPTION_audio_help, 321 "-audio-help print list of audio drivers and their options\n", 322 QEMU_ARCH_ALL) 323STEXI 324@item -audio-help 325@findex -audio-help 326Will show the audio subsystem help: list of drivers, tunable 327parameters. 328ETEXI 329 330DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw, 331 "-soundhw c1,... enable audio support\n" 332 " and only specified sound cards (comma separated list)\n" 333 " use '-soundhw help' to get the list of supported cards\n" 334 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL) 335STEXI 336@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all 337@findex -soundhw 338Enable audio and selected sound hardware. Use 'help' to print all 339available sound hardware. 340 341@example 342qemu-system-i386 -soundhw sb16,adlib disk.img 343qemu-system-i386 -soundhw es1370 disk.img 344qemu-system-i386 -soundhw ac97 disk.img 345qemu-system-i386 -soundhw hda disk.img 346qemu-system-i386 -soundhw all disk.img 347qemu-system-i386 -soundhw help 348@end example 349 350Note that Linux's i810_audio OSS kernel (for AC97) module might 351require manually specifying clocking. 352 353@example 354modprobe i810_audio clocking=48000 355@end example 356ETEXI 357 358DEF("balloon", HAS_ARG, QEMU_OPTION_balloon, 359 "-balloon none disable balloon device\n" 360 "-balloon virtio[,addr=str]\n" 361 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL) 362STEXI 363@item -balloon none 364@findex -balloon 365Disable balloon device. 366@item -balloon virtio[,addr=@var{addr}] 367Enable virtio balloon device (default), optionally with PCI address 368@var{addr}. 369ETEXI 370 371DEF("device", HAS_ARG, QEMU_OPTION_device, 372 "-device driver[,prop[=value][,...]]\n" 373 " add device (based on driver)\n" 374 " prop=value,... sets driver properties\n" 375 " use '-device help' to print all possible drivers\n" 376 " use '-device driver,help' to print all possible properties\n", 377 QEMU_ARCH_ALL) 378STEXI 379@item -device @var{driver}[,@var{prop}[=@var{value}][,...]] 380@findex -device 381Add device @var{driver}. @var{prop}=@var{value} sets driver 382properties. Valid properties depend on the driver. To get help on 383possible drivers and properties, use @code{-device help} and 384@code{-device @var{driver},help}. 385ETEXI 386 387DEF("name", HAS_ARG, QEMU_OPTION_name, 388 "-name string1[,process=string2][,debug-threads=on|off]\n" 389 " set the name of the guest\n" 390 " string1 sets the window title and string2 the process name (on Linux)\n" 391 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n" 392 " NOTE: The thread names are for debugging and not a stable API.\n", 393 QEMU_ARCH_ALL) 394STEXI 395@item -name @var{name} 396@findex -name 397Sets the @var{name} of the guest. 398This name will be displayed in the SDL window caption. 399The @var{name} will also be used for the VNC server. 400Also optionally set the top visible process name in Linux. 401Naming of individual threads can also be enabled on Linux to aid debugging. 402ETEXI 403 404DEF("uuid", HAS_ARG, QEMU_OPTION_uuid, 405 "-uuid %08x-%04x-%04x-%04x-%012x\n" 406 " specify machine UUID\n", QEMU_ARCH_ALL) 407STEXI 408@item -uuid @var{uuid} 409@findex -uuid 410Set system UUID. 411ETEXI 412 413STEXI 414@end table 415ETEXI 416DEFHEADING() 417 418DEFHEADING(Block device options:) 419STEXI 420@table @option 421ETEXI 422 423DEF("fda", HAS_ARG, QEMU_OPTION_fda, 424 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL) 425DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL) 426STEXI 427@item -fda @var{file} 428@itemx -fdb @var{file} 429@findex -fda 430@findex -fdb 431Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). 432ETEXI 433 434DEF("hda", HAS_ARG, QEMU_OPTION_hda, 435 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) 436DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) 437DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, 438 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) 439DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) 440STEXI 441@item -hda @var{file} 442@itemx -hdb @var{file} 443@itemx -hdc @var{file} 444@itemx -hdd @var{file} 445@findex -hda 446@findex -hdb 447@findex -hdc 448@findex -hdd 449Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}). 450ETEXI 451 452DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, 453 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", 454 QEMU_ARCH_ALL) 455STEXI 456@item -cdrom @var{file} 457@findex -cdrom 458Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and 459@option{-cdrom} at the same time). You can use the host CD-ROM by 460using @file{/dev/cdrom} as filename (@pxref{host_drives}). 461ETEXI 462 463DEF("drive", HAS_ARG, QEMU_OPTION_drive, 464 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n" 465 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n" 466 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n" 467 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n" 468 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n" 469 " [,readonly=on|off][,copy-on-read=on|off]\n" 470 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n" 471 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n" 472 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n" 473 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n" 474 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n" 475 " [[,iops_size=is]]\n" 476 " [[,group=g]]\n" 477 " use 'file' as a drive image\n", QEMU_ARCH_ALL) 478STEXI 479@item -drive @var{option}[,@var{option}[,@var{option}[,...]]] 480@findex -drive 481 482Define a new drive. Valid options are: 483 484@table @option 485@item file=@var{file} 486This option defines which disk image (@pxref{disk_images}) to use with 487this drive. If the filename contains comma, you must double it 488(for instance, "file=my,,file" to use file "my,file"). 489 490Special files such as iSCSI devices can be specified using protocol 491specific URLs. See the section for "Device URL Syntax" for more information. 492@item if=@var{interface} 493This option defines on which type on interface the drive is connected. 494Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio. 495@item bus=@var{bus},unit=@var{unit} 496These options define where is connected the drive by defining the bus number and 497the unit id. 498@item index=@var{index} 499This option defines where is connected the drive by using an index in the list 500of available connectors of a given interface type. 501@item media=@var{media} 502This option defines the type of the media: disk or cdrom. 503@item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}] 504These options have the same definition as they have in @option{-hdachs}. 505@item snapshot=@var{snapshot} 506@var{snapshot} is "on" or "off" and controls snapshot mode for the given drive 507(see @option{-snapshot}). 508@item cache=@var{cache} 509@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data. 510@item aio=@var{aio} 511@var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. 512@item discard=@var{discard} 513@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. 514@item format=@var{format} 515Specify which disk @var{format} will be used rather than detecting 516the format. Can be used to specifiy format=raw to avoid interpreting 517an untrusted format header. 518@item serial=@var{serial} 519This option specifies the serial number to assign to the device. 520@item addr=@var{addr} 521Specify the controller's PCI address (if=virtio only). 522@item werror=@var{action},rerror=@var{action} 523Specify which @var{action} to take on write and read errors. Valid actions are: 524"ignore" (ignore the error and try to continue), "stop" (pause QEMU), 525"report" (report the error to the guest), "enospc" (pause QEMU only if the 526host disk is full; report the error to the guest otherwise). 527The default setting is @option{werror=enospc} and @option{rerror=report}. 528@item readonly 529Open drive @option{file} as read-only. Guest write attempts will fail. 530@item copy-on-read=@var{copy-on-read} 531@var{copy-on-read} is "on" or "off" and enables whether to copy read backing 532file sectors into the image file. 533@item detect-zeroes=@var{detect-zeroes} 534@var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic 535conversion of plain zero writes by the OS to driver specific optimized 536zero write commands. You may even choose "unmap" if @var{discard} is set 537to "unmap" to allow a zero write to be converted to an UNMAP operation. 538@end table 539 540By default, the @option{cache=writeback} mode is used. It will report data 541writes as completed as soon as the data is present in the host page cache. 542This is safe as long as your guest OS makes sure to correctly flush disk caches 543where needed. If your guest OS does not handle volatile disk write caches 544correctly and your host crashes or loses power, then the guest may experience 545data corruption. 546 547For such guests, you should consider using @option{cache=writethrough}. This 548means that the host page cache will be used to read and write data, but write 549notification will be sent to the guest only after QEMU has made sure to flush 550each write to the disk. Be aware that this has a major impact on performance. 551 552The host page cache can be avoided entirely with @option{cache=none}. This will 553attempt to do disk IO directly to the guest's memory. QEMU may still perform 554an internal copy of the data. Note that this is considered a writeback mode and 555the guest OS must handle the disk write cache correctly in order to avoid data 556corruption on host crashes. 557 558The host page cache can be avoided while only sending write notifications to 559the guest when the data has been flushed to the disk using 560@option{cache=directsync}. 561 562In case you don't care about data integrity over host failures, use 563@option{cache=unsafe}. This option tells QEMU that it never needs to write any 564data to the disk but can instead keep things in cache. If anything goes wrong, 565like your host losing power, the disk storage getting disconnected accidentally, 566etc. your image will most probably be rendered unusable. When using 567the @option{-snapshot} option, unsafe caching is always used. 568 569Copy-on-read avoids accessing the same backing file sectors repeatedly and is 570useful when the backing file is over a slow network. By default copy-on-read 571is off. 572 573Instead of @option{-cdrom} you can use: 574@example 575qemu-system-i386 -drive file=file,index=2,media=cdrom 576@end example 577 578Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can 579use: 580@example 581qemu-system-i386 -drive file=file,index=0,media=disk 582qemu-system-i386 -drive file=file,index=1,media=disk 583qemu-system-i386 -drive file=file,index=2,media=disk 584qemu-system-i386 -drive file=file,index=3,media=disk 585@end example 586 587You can open an image using pre-opened file descriptors from an fd set: 588@example 589qemu-system-i386 590-add-fd fd=3,set=2,opaque="rdwr:/path/to/file" 591-add-fd fd=4,set=2,opaque="rdonly:/path/to/file" 592-drive file=/dev/fdset/2,index=0,media=disk 593@end example 594 595You can connect a CDROM to the slave of ide0: 596@example 597qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom 598@end example 599 600If you don't specify the "file=" argument, you define an empty drive: 601@example 602qemu-system-i386 -drive if=ide,index=1,media=cdrom 603@end example 604 605You can connect a SCSI disk with unit ID 6 on the bus #0: 606@example 607qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6 608@end example 609 610Instead of @option{-fda}, @option{-fdb}, you can use: 611@example 612qemu-system-i386 -drive file=file,index=0,if=floppy 613qemu-system-i386 -drive file=file,index=1,if=floppy 614@end example 615 616By default, @var{interface} is "ide" and @var{index} is automatically 617incremented: 618@example 619qemu-system-i386 -drive file=a -drive file=b" 620@end example 621is interpreted like: 622@example 623qemu-system-i386 -hda a -hdb b 624@end example 625ETEXI 626 627DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, 628 "-mtdblock file use 'file' as on-board Flash memory image\n", 629 QEMU_ARCH_ALL) 630STEXI 631@item -mtdblock @var{file} 632@findex -mtdblock 633Use @var{file} as on-board Flash memory image. 634ETEXI 635 636DEF("sd", HAS_ARG, QEMU_OPTION_sd, 637 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL) 638STEXI 639@item -sd @var{file} 640@findex -sd 641Use @var{file} as SecureDigital card image. 642ETEXI 643 644DEF("pflash", HAS_ARG, QEMU_OPTION_pflash, 645 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL) 646STEXI 647@item -pflash @var{file} 648@findex -pflash 649Use @var{file} as a parallel flash image. 650ETEXI 651 652DEF("snapshot", 0, QEMU_OPTION_snapshot, 653 "-snapshot write to temporary files instead of disk image files\n", 654 QEMU_ARCH_ALL) 655STEXI 656@item -snapshot 657@findex -snapshot 658Write to temporary files instead of disk image files. In this case, 659the raw disk image you use is not written back. You can however force 660the write back by pressing @key{C-a s} (@pxref{disk_images}). 661ETEXI 662 663DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \ 664 "-hdachs c,h,s[,t]\n" \ 665 " force hard disk 0 physical geometry and the optional BIOS\n" \ 666 " translation (t=none or lba) (usually QEMU can guess them)\n", 667 QEMU_ARCH_ALL) 668STEXI 669@item -hdachs @var{c},@var{h},@var{s},[,@var{t}] 670@findex -hdachs 671Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <= 672@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS 673translation mode (@var{t}=none, lba or auto). Usually QEMU can guess 674all those parameters. This option is useful for old MS-DOS disk 675images. 676ETEXI 677 678DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev, 679 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n" 680 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 681 QEMU_ARCH_ALL) 682 683STEXI 684 685@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}] 686@findex -fsdev 687Define a new file system device. Valid options are: 688@table @option 689@item @var{fsdriver} 690This option specifies the fs driver backend to use. 691Currently "local", "handle" and "proxy" file system drivers are supported. 692@item id=@var{id} 693Specifies identifier for this device 694@item path=@var{path} 695Specifies the export path for the file system device. Files under 696this path will be available to the 9p client on the guest. 697@item security_model=@var{security_model} 698Specifies the security model to be used for this export path. 699Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 700In "passthrough" security model, files are stored using the same 701credentials as they are created on the guest. This requires QEMU 702to run as root. In "mapped-xattr" security model, some of the file 703attributes like uid, gid, mode bits and link target are stored as 704file attributes. For "mapped-file" these attributes are stored in the 705hidden .virtfs_metadata directory. Directories exported by this security model cannot 706interact with other unix tools. "none" security model is same as 707passthrough except the sever won't report failures if it fails to 708set file attributes like ownership. Security model is mandatory 709only for local fsdriver. Other fsdrivers (like handle, proxy) don't take 710security model as a parameter. 711@item writeout=@var{writeout} 712This is an optional argument. The only supported value is "immediate". 713This means that host page cache will be used to read and write data but 714write notification will be sent to the guest only when the data has been 715reported as written by the storage subsystem. 716@item readonly 717Enables exporting 9p share as a readonly mount for guests. By default 718read-write access is given. 719@item socket=@var{socket} 720Enables proxy filesystem driver to use passed socket file for communicating 721with virtfs-proxy-helper 722@item sock_fd=@var{sock_fd} 723Enables proxy filesystem driver to use passed socket descriptor for 724communicating with virtfs-proxy-helper. Usually a helper like libvirt 725will create socketpair and pass one of the fds as sock_fd 726@end table 727 728-fsdev option is used along with -device driver "virtio-9p-pci". 729@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag} 730Options for virtio-9p-pci driver are: 731@table @option 732@item fsdev=@var{id} 733Specifies the id value specified along with -fsdev option 734@item mount_tag=@var{mount_tag} 735Specifies the tag name to be used by the guest to mount this export point 736@end table 737 738ETEXI 739 740DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, 741 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n" 742 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n", 743 QEMU_ARCH_ALL) 744 745STEXI 746 747@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}] 748@findex -virtfs 749 750The general form of a Virtual File system pass-through options are: 751@table @option 752@item @var{fsdriver} 753This option specifies the fs driver backend to use. 754Currently "local", "handle" and "proxy" file system drivers are supported. 755@item id=@var{id} 756Specifies identifier for this device 757@item path=@var{path} 758Specifies the export path for the file system device. Files under 759this path will be available to the 9p client on the guest. 760@item security_model=@var{security_model} 761Specifies the security model to be used for this export path. 762Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none". 763In "passthrough" security model, files are stored using the same 764credentials as they are created on the guest. This requires QEMU 765to run as root. In "mapped-xattr" security model, some of the file 766attributes like uid, gid, mode bits and link target are stored as 767file attributes. For "mapped-file" these attributes are stored in the 768hidden .virtfs_metadata directory. Directories exported by this security model cannot 769interact with other unix tools. "none" security model is same as 770passthrough except the sever won't report failures if it fails to 771set file attributes like ownership. Security model is mandatory only 772for local fsdriver. Other fsdrivers (like handle, proxy) don't take security 773model as a parameter. 774@item writeout=@var{writeout} 775This is an optional argument. The only supported value is "immediate". 776This means that host page cache will be used to read and write data but 777write notification will be sent to the guest only when the data has been 778reported as written by the storage subsystem. 779@item readonly 780Enables exporting 9p share as a readonly mount for guests. By default 781read-write access is given. 782@item socket=@var{socket} 783Enables proxy filesystem driver to use passed socket file for 784communicating with virtfs-proxy-helper. Usually a helper like libvirt 785will create socketpair and pass one of the fds as sock_fd 786@item sock_fd 787Enables proxy filesystem driver to use passed 'sock_fd' as the socket 788descriptor for interfacing with virtfs-proxy-helper 789@end table 790ETEXI 791 792DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth, 793 "-virtfs_synth Create synthetic file system image\n", 794 QEMU_ARCH_ALL) 795STEXI 796@item -virtfs_synth 797@findex -virtfs_synth 798Create synthetic file system image 799ETEXI 800 801STEXI 802@end table 803ETEXI 804DEFHEADING() 805 806DEFHEADING(USB options:) 807STEXI 808@table @option 809ETEXI 810 811DEF("usb", 0, QEMU_OPTION_usb, 812 "-usb enable the USB driver (will be the default soon)\n", 813 QEMU_ARCH_ALL) 814STEXI 815@item -usb 816@findex -usb 817Enable the USB driver (will be the default soon) 818ETEXI 819 820DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice, 821 "-usbdevice name add the host or guest USB device 'name'\n", 822 QEMU_ARCH_ALL) 823STEXI 824 825@item -usbdevice @var{devname} 826@findex -usbdevice 827Add the USB device @var{devname}. @xref{usb_devices}. 828 829@table @option 830 831@item mouse 832Virtual Mouse. This will override the PS/2 mouse emulation when activated. 833 834@item tablet 835Pointer device that uses absolute coordinates (like a touchscreen). This 836means QEMU is able to report the mouse position without having to grab the 837mouse. Also overrides the PS/2 mouse emulation when activated. 838 839@item disk:[format=@var{format}]:@var{file} 840Mass storage device based on file. The optional @var{format} argument 841will be used rather than detecting the format. Can be used to specifiy 842@code{format=raw} to avoid interpreting an untrusted format header. 843 844@item host:@var{bus}.@var{addr} 845Pass through the host device identified by @var{bus}.@var{addr} (Linux only). 846 847@item host:@var{vendor_id}:@var{product_id} 848Pass through the host device identified by @var{vendor_id}:@var{product_id} 849(Linux only). 850 851@item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev} 852Serial converter to host character device @var{dev}, see @code{-serial} for the 853available devices. 854 855@item braille 856Braille device. This will use BrlAPI to display the braille output on a real 857or fake device. 858 859@item net:@var{options} 860Network adapter that supports CDC ethernet and RNDIS protocols. 861 862@end table 863ETEXI 864 865STEXI 866@end table 867ETEXI 868DEFHEADING() 869 870DEFHEADING(Display options:) 871STEXI 872@table @option 873ETEXI 874 875DEF("display", HAS_ARG, QEMU_OPTION_display, 876 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n" 877 " [,window_close=on|off]|curses|none|\n" 878 " gtk[,grab_on_hover=on|off]|\n" 879 " vnc=<display>[,<optargs>]\n" 880 " select display type\n", QEMU_ARCH_ALL) 881STEXI 882@item -display @var{type} 883@findex -display 884Select type of display to use. This option is a replacement for the 885old style -sdl/-curses/... options. Valid values for @var{type} are 886@table @option 887@item sdl 888Display video output via SDL (usually in a separate graphics 889window; see the SDL documentation for other possibilities). 890@item curses 891Display video output via curses. For graphics device models which 892support a text mode, QEMU can display this output using a 893curses/ncurses interface. Nothing is displayed when the graphics 894device is in graphical mode or if the graphics device does not support 895a text mode. Generally only the VGA device models support text mode. 896@item none 897Do not display video output. The guest will still see an emulated 898graphics card, but its output will not be displayed to the QEMU 899user. This option differs from the -nographic option in that it 900only affects what is done with video output; -nographic also changes 901the destination of the serial and parallel port data. 902@item gtk 903Display video output in a GTK window. This interface provides drop-down 904menus and other UI elements to configure and control the VM during 905runtime. 906@item vnc 907Start a VNC server on display <arg> 908@end table 909ETEXI 910 911DEF("nographic", 0, QEMU_OPTION_nographic, 912 "-nographic disable graphical output and redirect serial I/Os to console\n", 913 QEMU_ARCH_ALL) 914STEXI 915@item -nographic 916@findex -nographic 917Normally, QEMU uses SDL to display the VGA output. With this option, 918you can totally disable graphical output so that QEMU is a simple 919command line application. The emulated serial port is redirected on 920the console and muxed with the monitor (unless redirected elsewhere 921explicitly). Therefore, you can still use QEMU to debug a Linux kernel 922with a serial console. Use @key{C-a h} for help on switching between 923the console and monitor. 924ETEXI 925 926DEF("curses", 0, QEMU_OPTION_curses, 927 "-curses use a curses/ncurses interface instead of SDL\n", 928 QEMU_ARCH_ALL) 929STEXI 930@item -curses 931@findex -curses 932Normally, QEMU uses SDL to display the VGA output. With this option, 933QEMU can display the VGA output when in text mode using a 934curses/ncurses interface. Nothing is displayed in graphical mode. 935ETEXI 936 937DEF("no-frame", 0, QEMU_OPTION_no_frame, 938 "-no-frame open SDL window without a frame and window decorations\n", 939 QEMU_ARCH_ALL) 940STEXI 941@item -no-frame 942@findex -no-frame 943Do not use decorations for SDL windows and start them using the whole 944available screen space. This makes the using QEMU in a dedicated desktop 945workspace more convenient. 946ETEXI 947 948DEF("alt-grab", 0, QEMU_OPTION_alt_grab, 949 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n", 950 QEMU_ARCH_ALL) 951STEXI 952@item -alt-grab 953@findex -alt-grab 954Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also 955affects the special keys (for fullscreen, monitor-mode switching, etc). 956ETEXI 957 958DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab, 959 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n", 960 QEMU_ARCH_ALL) 961STEXI 962@item -ctrl-grab 963@findex -ctrl-grab 964Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also 965affects the special keys (for fullscreen, monitor-mode switching, etc). 966ETEXI 967 968DEF("no-quit", 0, QEMU_OPTION_no_quit, 969 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL) 970STEXI 971@item -no-quit 972@findex -no-quit 973Disable SDL window close capability. 974ETEXI 975 976DEF("sdl", 0, QEMU_OPTION_sdl, 977 "-sdl enable SDL\n", QEMU_ARCH_ALL) 978STEXI 979@item -sdl 980@findex -sdl 981Enable SDL. 982ETEXI 983 984DEF("spice", HAS_ARG, QEMU_OPTION_spice, 985 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n" 986 " [,x509-key-file=<file>][,x509-key-password=<file>]\n" 987 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n" 988 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n" 989 " [,tls-ciphers=<list>]\n" 990 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n" 991 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n" 992 " [,sasl][,password=<secret>][,disable-ticketing]\n" 993 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n" 994 " [,jpeg-wan-compression=[auto|never|always]]\n" 995 " [,zlib-glz-wan-compression=[auto|never|always]]\n" 996 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n" 997 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n" 998 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n" 999 " enable spice\n" 1000 " at least one of {port, tls-port} is mandatory\n", 1001 QEMU_ARCH_ALL) 1002STEXI 1003@item -spice @var{option}[,@var{option}[,...]] 1004@findex -spice 1005Enable the spice remote desktop protocol. Valid options are 1006 1007@table @option 1008 1009@item port=<nr> 1010Set the TCP port spice is listening on for plaintext channels. 1011 1012@item addr=<addr> 1013Set the IP address spice is listening on. Default is any address. 1014 1015@item ipv4 1016@itemx ipv6 1017@itemx unix 1018Force using the specified IP version. 1019 1020@item password=<secret> 1021Set the password you need to authenticate. 1022 1023@item sasl 1024Require that the client use SASL to authenticate with the spice. 1025The exact choice of authentication method used is controlled from the 1026system / user's SASL configuration file for the 'qemu' service. This 1027is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1028unprivileged user, an environment variable SASL_CONF_PATH can be used 1029to make it search alternate locations for the service config. 1030While some SASL auth methods can also provide data encryption (eg GSSAPI), 1031it is recommended that SASL always be combined with the 'tls' and 1032'x509' settings to enable use of SSL and server certificates. This 1033ensures a data encryption preventing compromise of authentication 1034credentials. 1035 1036@item disable-ticketing 1037Allow client connects without authentication. 1038 1039@item disable-copy-paste 1040Disable copy paste between the client and the guest. 1041 1042@item disable-agent-file-xfer 1043Disable spice-vdagent based file-xfer between the client and the guest. 1044 1045@item tls-port=<nr> 1046Set the TCP port spice is listening on for encrypted channels. 1047 1048@item x509-dir=<dir> 1049Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir 1050 1051@item x509-key-file=<file> 1052@itemx x509-key-password=<file> 1053@itemx x509-cert-file=<file> 1054@itemx x509-cacert-file=<file> 1055@itemx x509-dh-key-file=<file> 1056The x509 file names can also be configured individually. 1057 1058@item tls-ciphers=<list> 1059Specify which ciphers to use. 1060 1061@item tls-channel=[main|display|cursor|inputs|record|playback] 1062@itemx plaintext-channel=[main|display|cursor|inputs|record|playback] 1063Force specific channel to be used with or without TLS encryption. The 1064options can be specified multiple times to configure multiple 1065channels. The special name "default" can be used to set the default 1066mode. For channels which are not explicitly forced into one mode the 1067spice client is allowed to pick tls/plaintext as he pleases. 1068 1069@item image-compression=[auto_glz|auto_lz|quic|glz|lz|off] 1070Configure image compression (lossless). 1071Default is auto_glz. 1072 1073@item jpeg-wan-compression=[auto|never|always] 1074@itemx zlib-glz-wan-compression=[auto|never|always] 1075Configure wan image compression (lossy for slow links). 1076Default is auto. 1077 1078@item streaming-video=[off|all|filter] 1079Configure video stream detection. Default is filter. 1080 1081@item agent-mouse=[on|off] 1082Enable/disable passing mouse events via vdagent. Default is on. 1083 1084@item playback-compression=[on|off] 1085Enable/disable audio stream compression (using celt 0.5.1). Default is on. 1086 1087@item seamless-migration=[on|off] 1088Enable/disable spice seamless migration. Default is off. 1089 1090@end table 1091ETEXI 1092 1093DEF("portrait", 0, QEMU_OPTION_portrait, 1094 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n", 1095 QEMU_ARCH_ALL) 1096STEXI 1097@item -portrait 1098@findex -portrait 1099Rotate graphical output 90 deg left (only PXA LCD). 1100ETEXI 1101 1102DEF("rotate", HAS_ARG, QEMU_OPTION_rotate, 1103 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n", 1104 QEMU_ARCH_ALL) 1105STEXI 1106@item -rotate @var{deg} 1107@findex -rotate 1108Rotate graphical output some deg left (only PXA LCD). 1109ETEXI 1110 1111DEF("vga", HAS_ARG, QEMU_OPTION_vga, 1112 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n" 1113 " select video card type\n", QEMU_ARCH_ALL) 1114STEXI 1115@item -vga @var{type} 1116@findex -vga 1117Select type of VGA card to emulate. Valid values for @var{type} are 1118@table @option 1119@item cirrus 1120Cirrus Logic GD5446 Video card. All Windows versions starting from 1121Windows 95 should recognize and use this graphic card. For optimal 1122performances, use 16 bit color depth in the guest and the host OS. 1123(This one is the default) 1124@item std 1125Standard VGA card with Bochs VBE extensions. If your guest OS 1126supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want 1127to use high resolution modes (>= 1280x1024x16) then you should use 1128this option. 1129@item vmware 1130VMWare SVGA-II compatible adapter. Use it if you have sufficiently 1131recent XFree86/XOrg server or Windows guest with a driver for this 1132card. 1133@item qxl 1134QXL paravirtual graphic card. It is VGA compatible (including VESA 11352.0 VBE support). Works best with qxl guest drivers installed though. 1136Recommended choice when using the spice protocol. 1137@item tcx 1138(sun4m only) Sun TCX framebuffer. This is the default framebuffer for 1139sun4m machines and offers both 8-bit and 24-bit colour depths at a 1140fixed resolution of 1024x768. 1141@item cg3 1142(sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer 1143for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP) 1144resolutions aimed at people wishing to run older Solaris versions. 1145@item virtio 1146Virtio VGA card. 1147@item none 1148Disable VGA card. 1149@end table 1150ETEXI 1151 1152DEF("full-screen", 0, QEMU_OPTION_full_screen, 1153 "-full-screen start in full screen\n", QEMU_ARCH_ALL) 1154STEXI 1155@item -full-screen 1156@findex -full-screen 1157Start in full screen. 1158ETEXI 1159 1160DEF("g", 1, QEMU_OPTION_g , 1161 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n", 1162 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 1163STEXI 1164@item -g @var{width}x@var{height}[x@var{depth}] 1165@findex -g 1166Set the initial graphical resolution and depth (PPC, SPARC only). 1167ETEXI 1168 1169DEF("vnc", HAS_ARG, QEMU_OPTION_vnc , 1170 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL) 1171STEXI 1172@item -vnc @var{display}[,@var{option}[,@var{option}[,...]]] 1173@findex -vnc 1174Normally, QEMU uses SDL to display the VGA output. With this option, 1175you can have QEMU listen on VNC display @var{display} and redirect the VGA 1176display over the VNC session. It is very useful to enable the usb 1177tablet device when using this option (option @option{-usbdevice 1178tablet}). When using the VNC display, you must use the @option{-k} 1179parameter to set the keyboard layout if you are not using en-us. Valid 1180syntax for the @var{display} is 1181 1182@table @option 1183 1184@item @var{host}:@var{d} 1185 1186TCP connections will only be allowed from @var{host} on display @var{d}. 1187By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can 1188be omitted in which case the server will accept connections from any host. 1189 1190@item unix:@var{path} 1191 1192Connections will be allowed over UNIX domain sockets where @var{path} is the 1193location of a unix socket to listen for connections on. 1194 1195@item none 1196 1197VNC is initialized but not started. The monitor @code{change} command 1198can be used to later start the VNC server. 1199 1200@end table 1201 1202Following the @var{display} value there may be one or more @var{option} flags 1203separated by commas. Valid options are 1204 1205@table @option 1206 1207@item reverse 1208 1209Connect to a listening VNC client via a ``reverse'' connection. The 1210client is specified by the @var{display}. For reverse network 1211connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument 1212is a TCP port number, not a display number. 1213 1214@item websocket 1215 1216Opens an additional TCP listening port dedicated to VNC Websocket connections. 1217By definition the Websocket port is 5700+@var{display}. If @var{host} is 1218specified connections will only be allowed from this host. 1219As an alternative the Websocket port could be specified by using 1220@code{websocket}=@var{port}. 1221If no TLS credentials are provided, the websocket connection runs in 1222unencrypted mode. If TLS credentials are provided, the websocket connection 1223requires encrypted client connections. 1224 1225@item password 1226 1227Require that password based authentication is used for client connections. 1228 1229The password must be set separately using the @code{set_password} command in 1230the @ref{pcsys_monitor}. The syntax to change your password is: 1231@code{set_password <protocol> <password>} where <protocol> could be either 1232"vnc" or "spice". 1233 1234If you would like to change <protocol> password expiration, you should use 1235@code{expire_password <protocol> <expiration-time>} where expiration time could 1236be one of the following options: now, never, +seconds or UNIX time of 1237expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800 1238to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this 1239date and time). 1240 1241You can also use keywords "now" or "never" for the expiration time to 1242allow <protocol> password to expire immediately or never expire. 1243 1244@item tls-creds=@var{ID} 1245 1246Provides the ID of a set of TLS credentials to use to secure the 1247VNC server. They will apply to both the normal VNC server socket 1248and the websocket socket (if enabled). Setting TLS credentials 1249will cause the VNC server socket to enable the VeNCrypt auth 1250mechanism. The credentials should have been previously created 1251using the @option{-object tls-creds} argument. 1252 1253The @option{tls-creds} parameter obsoletes the @option{tls}, 1254@option{x509}, and @option{x509verify} options, and as such 1255it is not permitted to set both new and old type options at 1256the same time. 1257 1258@item tls 1259 1260Require that client use TLS when communicating with the VNC server. This 1261uses anonymous TLS credentials so is susceptible to a man-in-the-middle 1262attack. It is recommended that this option be combined with either the 1263@option{x509} or @option{x509verify} options. 1264 1265This option is now deprecated in favor of using the @option{tls-creds} 1266argument. 1267 1268@item x509=@var{/path/to/certificate/dir} 1269 1270Valid if @option{tls} is specified. Require that x509 credentials are used 1271for negotiating the TLS session. The server will send its x509 certificate 1272to the client. It is recommended that a password be set on the VNC server 1273to provide authentication of the client when this is used. The path following 1274this option specifies where the x509 certificates are to be loaded from. 1275See the @ref{vnc_security} section for details on generating certificates. 1276 1277This option is now deprecated in favour of using the @option{tls-creds} 1278argument. 1279 1280@item x509verify=@var{/path/to/certificate/dir} 1281 1282Valid if @option{tls} is specified. Require that x509 credentials are used 1283for negotiating the TLS session. The server will send its x509 certificate 1284to the client, and request that the client send its own x509 certificate. 1285The server will validate the client's certificate against the CA certificate, 1286and reject clients when validation fails. If the certificate authority is 1287trusted, this is a sufficient authentication mechanism. You may still wish 1288to set a password on the VNC server as a second authentication layer. The 1289path following this option specifies where the x509 certificates are to 1290be loaded from. See the @ref{vnc_security} section for details on generating 1291certificates. 1292 1293This option is now deprecated in favour of using the @option{tls-creds} 1294argument. 1295 1296@item sasl 1297 1298Require that the client use SASL to authenticate with the VNC server. 1299The exact choice of authentication method used is controlled from the 1300system / user's SASL configuration file for the 'qemu' service. This 1301is typically found in /etc/sasl2/qemu.conf. If running QEMU as an 1302unprivileged user, an environment variable SASL_CONF_PATH can be used 1303to make it search alternate locations for the service config. 1304While some SASL auth methods can also provide data encryption (eg GSSAPI), 1305it is recommended that SASL always be combined with the 'tls' and 1306'x509' settings to enable use of SSL and server certificates. This 1307ensures a data encryption preventing compromise of authentication 1308credentials. See the @ref{vnc_security} section for details on using 1309SASL authentication. 1310 1311@item acl 1312 1313Turn on access control lists for checking of the x509 client certificate 1314and SASL party. For x509 certs, the ACL check is made against the 1315certificate's distinguished name. This is something that looks like 1316@code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is 1317made against the username, which depending on the SASL plugin, may 1318include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}. 1319When the @option{acl} flag is set, the initial access list will be 1320empty, with a @code{deny} policy. Thus no one will be allowed to 1321use the VNC server until the ACLs have been loaded. This can be 1322achieved using the @code{acl} monitor command. 1323 1324@item lossy 1325 1326Enable lossy compression methods (gradient, JPEG, ...). If this 1327option is set, VNC client may receive lossy framebuffer updates 1328depending on its encoding settings. Enabling this option can save 1329a lot of bandwidth at the expense of quality. 1330 1331@item non-adaptive 1332 1333Disable adaptive encodings. Adaptive encodings are enabled by default. 1334An adaptive encoding will try to detect frequently updated screen regions, 1335and send updates in these regions using a lossy encoding (like JPEG). 1336This can be really helpful to save bandwidth when playing videos. Disabling 1337adaptive encodings restores the original static behavior of encodings 1338like Tight. 1339 1340@item share=[allow-exclusive|force-shared|ignore] 1341 1342Set display sharing policy. 'allow-exclusive' allows clients to ask 1343for exclusive access. As suggested by the rfb spec this is 1344implemented by dropping other connections. Connecting multiple 1345clients in parallel requires all clients asking for a shared session 1346(vncviewer: -shared switch). This is the default. 'force-shared' 1347disables exclusive client access. Useful for shared desktop sessions, 1348where you don't want someone forgetting specify -shared disconnect 1349everybody else. 'ignore' completely ignores the shared flag and 1350allows everybody connect unconditionally. Doesn't conform to the rfb 1351spec but is traditional QEMU behavior. 1352 1353@end table 1354ETEXI 1355 1356STEXI 1357@end table 1358ETEXI 1359ARCHHEADING(, QEMU_ARCH_I386) 1360 1361ARCHHEADING(i386 target only:, QEMU_ARCH_I386) 1362STEXI 1363@table @option 1364ETEXI 1365 1366DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack, 1367 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n", 1368 QEMU_ARCH_I386) 1369STEXI 1370@item -win2k-hack 1371@findex -win2k-hack 1372Use it when installing Windows 2000 to avoid a disk full bug. After 1373Windows 2000 is installed, you no longer need this option (this option 1374slows down the IDE transfers). 1375ETEXI 1376 1377HXCOMM Deprecated by -rtc 1378DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386) 1379 1380DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk, 1381 "-no-fd-bootchk disable boot signature checking for floppy disks\n", 1382 QEMU_ARCH_I386) 1383STEXI 1384@item -no-fd-bootchk 1385@findex -no-fd-bootchk 1386Disable boot signature checking for floppy disks in BIOS. May 1387be needed to boot from old floppy disks. 1388ETEXI 1389 1390DEF("no-acpi", 0, QEMU_OPTION_no_acpi, 1391 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1392STEXI 1393@item -no-acpi 1394@findex -no-acpi 1395Disable ACPI (Advanced Configuration and Power Interface) support. Use 1396it if your guest OS complains about ACPI problems (PC target machine 1397only). 1398ETEXI 1399 1400DEF("no-hpet", 0, QEMU_OPTION_no_hpet, 1401 "-no-hpet disable HPET\n", QEMU_ARCH_I386) 1402STEXI 1403@item -no-hpet 1404@findex -no-hpet 1405Disable HPET support. 1406ETEXI 1407 1408DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable, 1409 "-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" 1410 " ACPI table description\n", QEMU_ARCH_I386) 1411STEXI 1412@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}]...] 1413@findex -acpitable 1414Add ACPI table with specified header fields and context from specified files. 1415For file=, take whole ACPI table from the specified files, including all 1416ACPI headers (possible overridden by other options). 1417For data=, only data 1418portion of the table is used, all header information is specified in the 1419command line. 1420ETEXI 1421 1422DEF("smbios", HAS_ARG, QEMU_OPTION_smbios, 1423 "-smbios file=binary\n" 1424 " load SMBIOS entry from binary file\n" 1425 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n" 1426 " [,uefi=on|off]\n" 1427 " specify SMBIOS type 0 fields\n" 1428 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1429 " [,uuid=uuid][,sku=str][,family=str]\n" 1430 " specify SMBIOS type 1 fields\n" 1431 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n" 1432 " [,asset=str][,location=str]\n" 1433 " specify SMBIOS type 2 fields\n" 1434 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n" 1435 " [,sku=str]\n" 1436 " specify SMBIOS type 3 fields\n" 1437 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n" 1438 " [,asset=str][,part=str]\n" 1439 " specify SMBIOS type 4 fields\n" 1440 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n" 1441 " [,asset=str][,part=str][,speed=%d]\n" 1442 " specify SMBIOS type 17 fields\n", 1443 QEMU_ARCH_I386 | QEMU_ARCH_ARM) 1444STEXI 1445@item -smbios file=@var{binary} 1446@findex -smbios 1447Load SMBIOS entry from binary file. 1448 1449@item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off] 1450Specify SMBIOS type 0 fields 1451 1452@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}] 1453Specify SMBIOS type 1 fields 1454 1455@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}] 1456Specify SMBIOS type 2 fields 1457 1458@item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}] 1459Specify SMBIOS type 3 fields 1460 1461@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}] 1462Specify SMBIOS type 4 fields 1463 1464@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}] 1465Specify SMBIOS type 17 fields 1466ETEXI 1467 1468STEXI 1469@end table 1470ETEXI 1471DEFHEADING() 1472 1473DEFHEADING(Network options:) 1474STEXI 1475@table @option 1476ETEXI 1477 1478HXCOMM Legacy slirp options (now moved to -net user): 1479#ifdef CONFIG_SLIRP 1480DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL) 1481DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL) 1482DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL) 1483#ifndef _WIN32 1484DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL) 1485#endif 1486#endif 1487 1488DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, 1489#ifdef CONFIG_SLIRP 1490 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n" 1491 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n" 1492 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]" 1493#ifndef _WIN32 1494 "[,smb=dir[,smbserver=addr]]\n" 1495#endif 1496 " configure a user mode network backend with ID 'str',\n" 1497 " its DHCP server and optional services\n" 1498#endif 1499#ifdef _WIN32 1500 "-netdev tap,id=str,ifname=name\n" 1501 " configure a host TAP network backend with ID 'str'\n" 1502#else 1503 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" 1504 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" 1505 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" 1506 " configure a host TAP network backend with ID 'str'\n" 1507 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n" 1508 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n" 1509 " to deconfigure it\n" 1510 " use '[down]script=no' to disable script execution\n" 1511 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n" 1512 " configure it\n" 1513 " use 'fd=h' to connect to an already opened TAP interface\n" 1514 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n" 1515 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n" 1516 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" 1517 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" 1518 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" 1519 " use vhost=on to enable experimental in kernel accelerator\n" 1520 " (only has effect for virtio guests which use MSIX)\n" 1521 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" 1522 " use 'vhostfd=h' to connect to an already opened vhost net device\n" 1523 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" 1524 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" 1525 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n" 1526 " configure a host TAP network backend with ID 'str' that is\n" 1527 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" 1528 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n" 1529#endif 1530#ifdef __linux__ 1531 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n" 1532 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n" 1533 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n" 1534 " [,rxcookie=rxcookie][,offset=offset]\n" 1535 " configure a network backend with ID 'str' connected to\n" 1536 " an Ethernet over L2TPv3 pseudowire.\n" 1537 " Linux kernel 3.3+ as well as most routers can talk\n" 1538 " L2TPv3. This transport allows connecting a VM to a VM,\n" 1539 " VM to a router and even VM to Host. It is a nearly-universal\n" 1540 " standard (RFC3391). Note - this implementation uses static\n" 1541 " pre-configured tunnels (same as the Linux kernel).\n" 1542 " use 'src=' to specify source address\n" 1543 " use 'dst=' to specify destination address\n" 1544 " use 'udp=on' to specify udp encapsulation\n" 1545 " use 'srcport=' to specify source udp port\n" 1546 " use 'dstport=' to specify destination udp port\n" 1547 " use 'ipv6=on' to force v6\n" 1548 " L2TPv3 uses cookies to prevent misconfiguration as\n" 1549 " well as a weak security measure\n" 1550 " use 'rxcookie=0x012345678' to specify a rxcookie\n" 1551 " use 'txcookie=0x012345678' to specify a txcookie\n" 1552 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n" 1553 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n" 1554 " use 'pincounter=on' to work around broken counter handling in peer\n" 1555 " use 'offset=X' to add an extra offset between header and data\n" 1556#endif 1557 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n" 1558 " configure a network backend to connect to another network\n" 1559 " using a socket connection\n" 1560 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" 1561 " configure a network backend to connect to a multicast maddr and port\n" 1562 " use 'localaddr=addr' to specify the host address to send packets from\n" 1563 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n" 1564 " configure a network backend to connect to another network\n" 1565 " using an UDP tunnel\n" 1566#ifdef CONFIG_VDE 1567 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n" 1568 " configure a network backend to connect to port 'n' of a vde switch\n" 1569 " running on host and listening for incoming connections on 'socketpath'.\n" 1570 " Use group 'groupname' and mode 'octalmode' to change default\n" 1571 " ownership and permissions for communication port.\n" 1572#endif 1573#ifdef CONFIG_NETMAP 1574 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n" 1575 " attach to the existing netmap-enabled network interface 'name', or to a\n" 1576 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n" 1577 " netmap device, defaults to '/dev/netmap')\n" 1578#endif 1579 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" 1580 " configure a vhost-user network, backed by a chardev 'dev'\n" 1581 "-netdev hubport,id=str,hubid=n\n" 1582 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL) 1583DEF("net", HAS_ARG, QEMU_OPTION_net, 1584 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n" 1585 " old way to create a new NIC and connect it to VLAN 'n'\n" 1586 " (use the '-device devtype,netdev=str' option if possible instead)\n" 1587 "-net dump[,vlan=n][,file=f][,len=n]\n" 1588 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n" 1589 "-net none use it alone to have zero network devices. If no -net option\n" 1590 " is provided, the default is '-net nic -net user'\n" 1591 "-net [" 1592#ifdef CONFIG_SLIRP 1593 "user|" 1594#endif 1595 "tap|" 1596 "bridge|" 1597#ifdef CONFIG_VDE 1598 "vde|" 1599#endif 1600#ifdef CONFIG_NETMAP 1601 "netmap|" 1602#endif 1603 "socket][,vlan=n][,option][,option][,...]\n" 1604 " old way to initialize a host network interface\n" 1605 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL) 1606STEXI 1607@item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}] 1608@findex -net 1609Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n} 1610= 0 is the default). The NIC is an e1000 by default on the PC 1611target. Optionally, the MAC address can be changed to @var{mac}, the 1612device address set to @var{addr} (PCI cards only), 1613and a @var{name} can be assigned for use in monitor commands. 1614Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors 1615that the card should have; this option currently only affects virtio cards; set 1616@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single 1617NIC is created. QEMU can emulate several different models of network card. 1618Valid values for @var{type} are 1619@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er}, 1620@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139}, 1621@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}. 1622Not all devices are supported on all targets. Use @code{-net nic,model=help} 1623for a list of available devices for your target. 1624 1625@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...] 1626@findex -netdev 1627@item -net user[,@var{option}][,@var{option}][,...] 1628Use the user mode network stack which requires no administrator 1629privilege to run. Valid options are: 1630 1631@table @option 1632@item vlan=@var{n} 1633Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default). 1634 1635@item id=@var{id} 1636@itemx name=@var{name} 1637Assign symbolic name for use in monitor commands. 1638 1639@item net=@var{addr}[/@var{mask}] 1640Set IP network address the guest will see. Optionally specify the netmask, 1641either in the form a.b.c.d or as number of valid top-most bits. Default is 164210.0.2.0/24. 1643 1644@item host=@var{addr} 1645Specify the guest-visible address of the host. Default is the 2nd IP in the 1646guest network, i.e. x.x.x.2. 1647 1648@item restrict=on|off 1649If this option is enabled, the guest will be isolated, i.e. it will not be 1650able to contact the host and no guest IP packets will be routed over the host 1651to the outside. This option does not affect any explicitly set forwarding rules. 1652 1653@item hostname=@var{name} 1654Specifies the client hostname reported by the built-in DHCP server. 1655 1656@item dhcpstart=@var{addr} 1657Specify the first of the 16 IPs the built-in DHCP server can assign. Default 1658is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31. 1659 1660@item dns=@var{addr} 1661Specify the guest-visible address of the virtual nameserver. The address must 1662be different from the host address. Default is the 3rd IP in the guest network, 1663i.e. x.x.x.3. 1664 1665@item dnssearch=@var{domain} 1666Provides an entry for the domain-search list sent by the built-in 1667DHCP server. More than one domain suffix can be transmitted by specifying 1668this option multiple times. If supported, this will cause the guest to 1669automatically try to append the given domain suffix(es) in case a domain name 1670can not be resolved. 1671 1672Example: 1673@example 1674qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...] 1675@end example 1676 1677@item tftp=@var{dir} 1678When using the user mode network stack, activate a built-in TFTP 1679server. The files in @var{dir} will be exposed as the root of a TFTP server. 1680The TFTP client on the guest must be configured in binary mode (use the command 1681@code{bin} of the Unix TFTP client). 1682 1683@item bootfile=@var{file} 1684When using the user mode network stack, broadcast @var{file} as the BOOTP 1685filename. In conjunction with @option{tftp}, this can be used to network boot 1686a guest from a local directory. 1687 1688Example (using pxelinux): 1689@example 1690qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0 1691@end example 1692 1693@item smb=@var{dir}[,smbserver=@var{addr}] 1694When using the user mode network stack, activate a built-in SMB 1695server so that Windows OSes can access to the host files in @file{@var{dir}} 1696transparently. The IP address of the SMB server can be set to @var{addr}. By 1697default the 4th IP in the guest network is used, i.e. x.x.x.4. 1698 1699In the guest Windows OS, the line: 1700@example 170110.0.2.4 smbserver 1702@end example 1703must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me) 1704or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000). 1705 1706Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}. 1707 1708Note that a SAMBA server must be installed on the host OS. 1709QEMU was tested successfully with smbd versions from Red Hat 9, 1710Fedora Core 3 and OpenSUSE 11.x. 1711 1712@item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport} 1713Redirect incoming TCP or UDP connections to the host port @var{hostport} to 1714the guest IP address @var{guestaddr} on guest port @var{guestport}. If 1715@var{guestaddr} is not specified, its value is x.x.x.15 (default first address 1716given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can 1717be bound to a specific host interface. If no connection type is set, TCP is 1718used. This option can be given multiple times. 1719 1720For example, to redirect host X11 connection from screen 1 to guest 1721screen 0, use the following: 1722 1723@example 1724# on the host 1725qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...] 1726# this host xterm should open in the guest X11 server 1727xterm -display :1 1728@end example 1729 1730To redirect telnet connections from host port 5555 to telnet port on 1731the guest, use the following: 1732 1733@example 1734# on the host 1735qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...] 1736telnet localhost 5555 1737@end example 1738 1739Then when you use on the host @code{telnet localhost 5555}, you 1740connect to the guest telnet server. 1741 1742@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev} 1743@itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command} 1744Forward guest TCP connections to the IP address @var{server} on port @var{port} 1745to the character device @var{dev} or to a program executed by @var{cmd:command} 1746which gets spawned for each connection. This option can be given multiple times. 1747 1748You can either use a chardev directly and have that one used throughout QEMU's 1749lifetime, like in the following example: 1750 1751@example 1752# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever 1753# the guest accesses it 1754qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...] 1755@end example 1756 1757Or you can execute a command on every TCP connection established by the guest, 1758so that QEMU behaves similar to an inetd process for that virtual server: 1759 1760@example 1761# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234 1762# and connect the TCP stream to its stdin/stdout 1763qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' 1764@end example 1765 1766@end table 1767 1768Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still 1769processed and applied to -net user. Mixing them with the new configuration 1770syntax gives undefined results. Their use for new applications is discouraged 1771as they will be removed from future versions. 1772 1773@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1774@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}] 1775Connect the host TAP network interface @var{name} to VLAN @var{n}. 1776 1777Use the network script @var{file} to configure it and the network script 1778@var{dfile} to deconfigure it. If @var{name} is not provided, the OS 1779automatically provides one. The default network configure script is 1780@file{/etc/qemu-ifup} and the default network deconfigure script is 1781@file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no} 1782to disable script execution. 1783 1784If running QEMU as an unprivileged user, use the network helper 1785@var{helper} to configure the TAP interface. The default network 1786helper executable is @file{/path/to/qemu-bridge-helper}. 1787 1788@option{fd}=@var{h} can be used to specify the handle of an already 1789opened host TAP interface. 1790 1791Examples: 1792 1793@example 1794#launch a QEMU instance with the default network script 1795qemu-system-i386 linux.img -net nic -net tap 1796@end example 1797 1798@example 1799#launch a QEMU instance with two NICs, each one connected 1800#to a TAP device 1801qemu-system-i386 linux.img \ 1802 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ 1803 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 1804@end example 1805 1806@example 1807#launch a QEMU instance with the default network helper to 1808#connect a TAP device to bridge br0 1809qemu-system-i386 linux.img \ 1810 -net nic -net tap,"helper=/path/to/qemu-bridge-helper" 1811@end example 1812 1813@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}] 1814@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}] 1815Connect a host TAP network interface to a host bridge device. 1816 1817Use the network helper @var{helper} to configure the TAP interface and 1818attach it to the bridge. The default network helper executable is 1819@file{/path/to/qemu-bridge-helper} and the default bridge 1820device is @file{br0}. 1821 1822Examples: 1823 1824@example 1825#launch a QEMU instance with the default network helper to 1826#connect a TAP device to bridge br0 1827qemu-system-i386 linux.img -net bridge -net nic,model=virtio 1828@end example 1829 1830@example 1831#launch a QEMU instance with the default network helper to 1832#connect a TAP device to bridge qemubr0 1833qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio 1834@end example 1835 1836@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1837@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] 1838 1839Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual 1840machine using a TCP socket connection. If @option{listen} is 1841specified, QEMU waits for incoming connections on @var{port} 1842(@var{host} is optional). @option{connect} is used to connect to 1843another QEMU instance using the @option{listen} option. @option{fd}=@var{h} 1844specifies an already opened TCP socket. 1845 1846Example: 1847@example 1848# launch a first QEMU instance 1849qemu-system-i386 linux.img \ 1850 -net nic,macaddr=52:54:00:12:34:56 \ 1851 -net socket,listen=:1234 1852# connect the VLAN 0 of this instance to the VLAN 0 1853# of the first instance 1854qemu-system-i386 linux.img \ 1855 -net nic,macaddr=52:54:00:12:34:57 \ 1856 -net socket,connect=127.0.0.1:1234 1857@end example 1858 1859@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1860@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] 1861 1862Create a VLAN @var{n} shared with another QEMU virtual 1863machines using a UDP multicast socket, effectively making a bus for 1864every QEMU with same multicast address @var{maddr} and @var{port}. 1865NOTES: 1866@enumerate 1867@item 1868Several QEMU can be running on different hosts and share same bus (assuming 1869correct multicast setup for these hosts). 1870@item 1871mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see 1872@url{http://user-mode-linux.sf.net}. 1873@item 1874Use @option{fd=h} to specify an already opened UDP multicast socket. 1875@end enumerate 1876 1877Example: 1878@example 1879# launch one QEMU instance 1880qemu-system-i386 linux.img \ 1881 -net nic,macaddr=52:54:00:12:34:56 \ 1882 -net socket,mcast=230.0.0.1:1234 1883# launch another QEMU instance on same "bus" 1884qemu-system-i386 linux.img \ 1885 -net nic,macaddr=52:54:00:12:34:57 \ 1886 -net socket,mcast=230.0.0.1:1234 1887# launch yet another QEMU instance on same "bus" 1888qemu-system-i386 linux.img \ 1889 -net nic,macaddr=52:54:00:12:34:58 \ 1890 -net socket,mcast=230.0.0.1:1234 1891@end example 1892 1893Example (User Mode Linux compat.): 1894@example 1895# launch QEMU instance (note mcast address selected 1896# is UML's default) 1897qemu-system-i386 linux.img \ 1898 -net nic,macaddr=52:54:00:12:34:56 \ 1899 -net socket,mcast=239.192.168.1:1102 1900# launch UML 1901/path/to/linux ubd0=/path/to/root_fs eth0=mcast 1902@end example 1903 1904Example (send packets from host's 1.2.3.4): 1905@example 1906qemu-system-i386 linux.img \ 1907 -net nic,macaddr=52:54:00:12:34:56 \ 1908 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 1909@end example 1910 1911@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}] 1912@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}] 1913Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular 1914protocol to transport Ethernet (and other Layer 2) data frames between 1915two systems. It is present in routers, firewalls and the Linux kernel 1916(from version 3.3 onwards). 1917 1918This transport allows a VM to communicate to another VM, router or firewall directly. 1919 1920@item src=@var{srcaddr} 1921 source address (mandatory) 1922@item dst=@var{dstaddr} 1923 destination address (mandatory) 1924@item udp 1925 select udp encapsulation (default is ip). 1926@item srcport=@var{srcport} 1927 source udp port. 1928@item dstport=@var{dstport} 1929 destination udp port. 1930@item ipv6 1931 force v6, otherwise defaults to v4. 1932@item rxcookie=@var{rxcookie} 1933@itemx txcookie=@var{txcookie} 1934 Cookies are a weak form of security in the l2tpv3 specification. 1935Their function is mostly to prevent misconfiguration. By default they are 32 1936bit. 1937@item cookie64 1938 Set cookie size to 64 bit instead of the default 32 1939@item counter=off 1940 Force a 'cut-down' L2TPv3 with no counter as in 1941draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00 1942@item pincounter=on 1943 Work around broken counter handling in peer. This may also help on 1944networks which have packet reorder. 1945@item offset=@var{offset} 1946 Add an extra offset between header and data 1947 1948For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan 1949on the remote Linux host 1.2.3.4: 1950@example 1951# Setup tunnel on linux host using raw ip as encapsulation 1952# on 1.2.3.4 1953ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \ 1954 encap udp udp_sport 16384 udp_dport 16384 1955ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \ 1956 0xFFFFFFFF peer_session_id 0xFFFFFFFF 1957ifconfig vmtunnel0 mtu 1500 1958ifconfig vmtunnel0 up 1959brctl addif br-lan vmtunnel0 1960 1961 1962# on 4.3.2.1 1963# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter 1964 1965qemu-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 1966 1967 1968@end example 1969 1970@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 1971@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}] 1972Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and 1973listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname} 1974and MODE @var{octalmode} to change default ownership and permissions for 1975communication port. This option is only available if QEMU has been compiled 1976with vde support enabled. 1977 1978Example: 1979@example 1980# launch vde switch 1981vde_switch -F -sock /tmp/myswitch 1982# launch QEMU instance 1983qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch 1984@end example 1985 1986@item -netdev hubport,id=@var{id},hubid=@var{hubid} 1987 1988Create a hub port on QEMU "vlan" @var{hubid}. 1989 1990The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single 1991netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the 1992required hub automatically. 1993 1994@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n] 1995 1996Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should 1997be a unix domain socket backed one. The vhost-user uses a specifically defined 1998protocol to pass vhost ioctl replacement messages to an application on the other 1999end of the socket. On non-MSIX guests, the feature can be forced with 2000@var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to 2001be created for multiqueue vhost-user. 2002 2003Example: 2004@example 2005qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \ 2006 -numa node,memdev=mem \ 2007 -chardev socket,path=/path/to/socket \ 2008 -netdev type=vhost-user,id=net0,chardev=chr0 \ 2009 -device virtio-net-pci,netdev=net0 2010@end example 2011 2012@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}] 2013Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default). 2014At most @var{len} bytes (64k by default) per packet are stored. The file format is 2015libpcap, so it can be analyzed with tools such as tcpdump or Wireshark. 2016Note: For devices created with '-netdev', use '-object filter-dump,...' instead. 2017 2018@item -net none 2019Indicate that no network devices should be configured. It is used to 2020override the default configuration (@option{-net nic -net user}) which 2021is activated if no @option{-net} options are provided. 2022ETEXI 2023 2024STEXI 2025@end table 2026ETEXI 2027DEFHEADING() 2028 2029DEFHEADING(Character device options:) 2030STEXI 2031 2032The general form of a character device option is: 2033@table @option 2034ETEXI 2035 2036DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, 2037 "-chardev null,id=id[,mux=on|off]\n" 2038 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n" 2039 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (tcp)\n" 2040 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (unix)\n" 2041 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" 2042 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" 2043 "-chardev msmouse,id=id[,mux=on|off]\n" 2044 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" 2045 " [,mux=on|off]\n" 2046 "-chardev ringbuf,id=id[,size=size]\n" 2047 "-chardev file,id=id,path=path[,mux=on|off]\n" 2048 "-chardev pipe,id=id,path=path[,mux=on|off]\n" 2049#ifdef _WIN32 2050 "-chardev console,id=id[,mux=on|off]\n" 2051 "-chardev serial,id=id,path=path[,mux=on|off]\n" 2052#else 2053 "-chardev pty,id=id[,mux=on|off]\n" 2054 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n" 2055#endif 2056#ifdef CONFIG_BRLAPI 2057 "-chardev braille,id=id[,mux=on|off]\n" 2058#endif 2059#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 2060 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) 2061 "-chardev serial,id=id,path=path[,mux=on|off]\n" 2062 "-chardev tty,id=id,path=path[,mux=on|off]\n" 2063#endif 2064#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) 2065 "-chardev parallel,id=id,path=path[,mux=on|off]\n" 2066 "-chardev parport,id=id,path=path[,mux=on|off]\n" 2067#endif 2068#if defined(CONFIG_SPICE) 2069 "-chardev spicevmc,id=id,name=name[,debug=debug]\n" 2070 "-chardev spiceport,id=id,name=name[,debug=debug]\n" 2071#endif 2072 , QEMU_ARCH_ALL 2073) 2074 2075STEXI 2076@item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}] 2077@findex -chardev 2078Backend is one of: 2079@option{null}, 2080@option{socket}, 2081@option{udp}, 2082@option{msmouse}, 2083@option{vc}, 2084@option{ringbuf}, 2085@option{file}, 2086@option{pipe}, 2087@option{console}, 2088@option{serial}, 2089@option{pty}, 2090@option{stdio}, 2091@option{braille}, 2092@option{tty}, 2093@option{parallel}, 2094@option{parport}, 2095@option{spicevmc}. 2096@option{spiceport}. 2097The specific backend will determine the applicable options. 2098 2099All devices must have an id, which can be any string up to 127 characters long. 2100It is used to uniquely identify this device in other command line directives. 2101 2102A character device may be used in multiplexing mode by multiple front-ends. 2103The key sequence of @key{Control-a} and @key{c} will rotate the input focus 2104between attached front-ends. Specify @option{mux=on} to enable this mode. 2105 2106Options to each backend are described below. 2107 2108@item -chardev null ,id=@var{id} 2109A void device. This device will not emit any data, and will drop any data it 2110receives. The null backend does not take any options. 2111 2112@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] 2113 2114Create a two-way stream socket, which can be either a TCP or a unix socket. A 2115unix socket will be created if @option{path} is specified. Behaviour is 2116undefined if TCP options are specified for a unix socket. 2117 2118@option{server} specifies that the socket shall be a listening socket. 2119 2120@option{nowait} specifies that QEMU should not block waiting for a client to 2121connect to a listening socket. 2122 2123@option{telnet} specifies that traffic on the socket should interpret telnet 2124escape sequences. 2125 2126@option{reconnect} sets the timeout for reconnecting on non-server sockets when 2127the remote end goes away. qemu will delay this many seconds and then attempt 2128to reconnect. Zero disables reconnecting, and is the default. 2129 2130TCP and unix socket options are given below: 2131 2132@table @option 2133 2134@item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay] 2135 2136@option{host} for a listening socket specifies the local address to be bound. 2137For a connecting socket species the remote host to connect to. @option{host} is 2138optional for listening sockets. If not specified it defaults to @code{0.0.0.0}. 2139 2140@option{port} for a listening socket specifies the local port to be bound. For a 2141connecting socket specifies the port on the remote host to connect to. 2142@option{port} can be given as either a port number or a service name. 2143@option{port} is required. 2144 2145@option{to} is only relevant to listening sockets. If it is specified, and 2146@option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up 2147to and including @option{to} until it succeeds. @option{to} must be specified 2148as a port number. 2149 2150@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2151If neither is specified the socket may use either protocol. 2152 2153@option{nodelay} disables the Nagle algorithm. 2154 2155@item unix options: path=@var{path} 2156 2157@option{path} specifies the local path of the unix socket. @option{path} is 2158required. 2159 2160@end table 2161 2162@item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6] 2163 2164Sends all traffic from the guest to a remote host over UDP. 2165 2166@option{host} specifies the remote host to connect to. If not specified it 2167defaults to @code{localhost}. 2168 2169@option{port} specifies the port on the remote host to connect to. @option{port} 2170is required. 2171 2172@option{localaddr} specifies the local address to bind to. If not specified it 2173defaults to @code{0.0.0.0}. 2174 2175@option{localport} specifies the local port to bind to. If not specified any 2176available local port will be used. 2177 2178@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used. 2179If neither is specified the device may use either protocol. 2180 2181@item -chardev msmouse ,id=@var{id} 2182 2183Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not 2184take any options. 2185 2186@item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]] 2187 2188Connect to a QEMU text console. @option{vc} may optionally be given a specific 2189size. 2190 2191@option{width} and @option{height} specify the width and height respectively of 2192the console, in pixels. 2193 2194@option{cols} and @option{rows} specify that the console be sized to fit a text 2195console with the given dimensions. 2196 2197@item -chardev ringbuf ,id=@var{id} [,size=@var{size}] 2198 2199Create a ring buffer with fixed size @option{size}. 2200@var{size} must be a power of two, and defaults to @code{64K}). 2201 2202@item -chardev file ,id=@var{id} ,path=@var{path} 2203 2204Log all traffic received from the guest to a file. 2205 2206@option{path} specifies the path of the file to be opened. This file will be 2207created if it does not already exist, and overwritten if it does. @option{path} 2208is required. 2209 2210@item -chardev pipe ,id=@var{id} ,path=@var{path} 2211 2212Create a two-way connection to the guest. The behaviour differs slightly between 2213Windows hosts and other hosts: 2214 2215On Windows, a single duplex pipe will be created at 2216@file{\\.pipe\@option{path}}. 2217 2218On other hosts, 2 pipes will be created called @file{@option{path}.in} and 2219@file{@option{path}.out}. Data written to @file{@option{path}.in} will be 2220received by the guest. Data written by the guest can be read from 2221@file{@option{path}.out}. QEMU will not create these fifos, and requires them to 2222be present. 2223 2224@option{path} forms part of the pipe path as described above. @option{path} is 2225required. 2226 2227@item -chardev console ,id=@var{id} 2228 2229Send traffic from the guest to QEMU's standard output. @option{console} does not 2230take any options. 2231 2232@option{console} is only available on Windows hosts. 2233 2234@item -chardev serial ,id=@var{id} ,path=@option{path} 2235 2236Send traffic from the guest to a serial device on the host. 2237 2238On Unix hosts serial will actually accept any tty device, 2239not only serial lines. 2240 2241@option{path} specifies the name of the serial device to open. 2242 2243@item -chardev pty ,id=@var{id} 2244 2245Create a new pseudo-terminal on the host and connect to it. @option{pty} does 2246not take any options. 2247 2248@option{pty} is not available on Windows hosts. 2249 2250@item -chardev stdio ,id=@var{id} [,signal=on|off] 2251Connect to standard input and standard output of the QEMU process. 2252 2253@option{signal} controls if signals are enabled on the terminal, that includes 2254exiting QEMU with the key sequence @key{Control-c}. This option is enabled by 2255default, use @option{signal=off} to disable it. 2256 2257@option{stdio} is not available on Windows hosts. 2258 2259@item -chardev braille ,id=@var{id} 2260 2261Connect to a local BrlAPI server. @option{braille} does not take any options. 2262 2263@item -chardev tty ,id=@var{id} ,path=@var{path} 2264 2265@option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and 2266DragonFlyBSD hosts. It is an alias for @option{serial}. 2267 2268@option{path} specifies the path to the tty. @option{path} is required. 2269 2270@item -chardev parallel ,id=@var{id} ,path=@var{path} 2271@itemx -chardev parport ,id=@var{id} ,path=@var{path} 2272 2273@option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts. 2274 2275Connect to a local parallel port. 2276 2277@option{path} specifies the path to the parallel port device. @option{path} is 2278required. 2279 2280@item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2281 2282@option{spicevmc} is only available when spice support is built in. 2283 2284@option{debug} debug level for spicevmc 2285 2286@option{name} name of spice channel to connect to 2287 2288Connect to a spice virtual machine channel, such as vdiport. 2289 2290@item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name} 2291 2292@option{spiceport} is only available when spice support is built in. 2293 2294@option{debug} debug level for spicevmc 2295 2296@option{name} name of spice port to connect to 2297 2298Connect to a spice port, allowing a Spice client to handle the traffic 2299identified by a name (preferably a fqdn). 2300ETEXI 2301 2302STEXI 2303@end table 2304ETEXI 2305DEFHEADING() 2306 2307DEFHEADING(Device URL Syntax:) 2308STEXI 2309 2310In addition to using normal file images for the emulated storage devices, 2311QEMU can also use networked resources such as iSCSI devices. These are 2312specified using a special URL syntax. 2313 2314@table @option 2315@item iSCSI 2316iSCSI support allows QEMU to access iSCSI resources directly and use as 2317images for the guest storage. Both disk and cdrom images are supported. 2318 2319Syntax for specifying iSCSI LUNs is 2320``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>'' 2321 2322By default qemu will use the iSCSI initiator-name 2323'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command 2324line or a configuration file. 2325 2326Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect 2327stalled requests and force a reestablishment of the session. The timeout 2328is specified in seconds. The default is 0 which means no timeout. Libiscsi 23291.15.0 or greater is required for this feature. 2330 2331Example (without authentication): 2332@example 2333qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \ 2334 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \ 2335 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2336@end example 2337 2338Example (CHAP username/password via URL): 2339@example 2340qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1 2341@end example 2342 2343Example (CHAP username/password via environment variables): 2344@example 2345LIBISCSI_CHAP_USERNAME="user" \ 2346LIBISCSI_CHAP_PASSWORD="password" \ 2347qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1 2348@end example 2349 2350iSCSI support is an optional feature of QEMU and only available when 2351compiled and linked against libiscsi. 2352ETEXI 2353DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi, 2354 "-iscsi [user=user][,password=password]\n" 2355 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n" 2356 " [,initiator-name=initiator-iqn][,id=target-iqn]\n" 2357 " [,timeout=timeout]\n" 2358 " iSCSI session parameters\n", QEMU_ARCH_ALL) 2359STEXI 2360 2361iSCSI parameters such as username and password can also be specified via 2362a configuration file. See qemu-doc for more information and examples. 2363 2364@item NBD 2365QEMU supports NBD (Network Block Devices) both using TCP protocol as well 2366as Unix Domain Sockets. 2367 2368Syntax for specifying a NBD device using TCP 2369``nbd:<server-ip>:<port>[:exportname=<export>]'' 2370 2371Syntax for specifying a NBD device using Unix Domain Sockets 2372``nbd:unix:<domain-socket>[:exportname=<export>]'' 2373 2374 2375Example for TCP 2376@example 2377qemu-system-i386 --drive file=nbd:192.0.2.1:30000 2378@end example 2379 2380Example for Unix Domain Sockets 2381@example 2382qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket 2383@end example 2384 2385@item SSH 2386QEMU supports SSH (Secure Shell) access to remote disks. 2387 2388Examples: 2389@example 2390qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img 2391qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img 2392@end example 2393 2394Currently authentication must be done using ssh-agent. Other 2395authentication methods may be supported in future. 2396 2397@item Sheepdog 2398Sheepdog is a distributed storage system for QEMU. 2399QEMU supports using either local sheepdog devices or remote networked 2400devices. 2401 2402Syntax for specifying a sheepdog device 2403@example 2404sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag] 2405@end example 2406 2407Example 2408@example 2409qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine 2410@end example 2411 2412See also @url{http://http://www.osrg.net/sheepdog/}. 2413 2414@item GlusterFS 2415GlusterFS is an user space distributed file system. 2416QEMU supports the use of GlusterFS volumes for hosting VM disk images using 2417TCP, Unix Domain Sockets and RDMA transport protocols. 2418 2419Syntax for specifying a VM disk image on GlusterFS volume is 2420@example 2421gluster[+transport]://[server[:port]]/volname/image[?socket=...] 2422@end example 2423 2424 2425Example 2426@example 2427qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img 2428@end example 2429 2430See also @url{http://www.gluster.org}. 2431 2432@item HTTP/HTTPS/FTP/FTPS/TFTP 2433QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp. 2434 2435Syntax using a single filename: 2436@example 2437<protocol>://[<username>[:<password>]@@]<host>/<path> 2438@end example 2439 2440where: 2441@table @option 2442@item protocol 2443'http', 'https', 'ftp', 'ftps', or 'tftp'. 2444 2445@item username 2446Optional username for authentication to the remote server. 2447 2448@item password 2449Optional password for authentication to the remote server. 2450 2451@item host 2452Address of the remote server. 2453 2454@item path 2455Path on the remote server, including any query string. 2456@end table 2457 2458The following options are also supported: 2459@table @option 2460@item url 2461The full URL when passing options to the driver explicitly. 2462 2463@item readahead 2464The amount of data to read ahead with each range request to the remote server. 2465This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it 2466does not have a suffix, it will be assumed to be in bytes. The value must be a 2467multiple of 512 bytes. It defaults to 256k. 2468 2469@item sslverify 2470Whether to verify the remote server's certificate when connecting over SSL. It 2471can have the value 'on' or 'off'. It defaults to 'on'. 2472 2473@item cookie 2474Send this cookie (it can also be a list of cookies separated by ';') with 2475each outgoing request. Only supported when using protocols such as HTTP 2476which support cookies, otherwise ignored. 2477 2478@item timeout 2479Set the timeout in seconds of the CURL connection. This timeout is the time 2480that CURL waits for a response from the remote server to get the size of the 2481image to be downloaded. If not set, the default timeout of 5 seconds is used. 2482@end table 2483 2484Note that when passing options to qemu explicitly, @option{driver} is the value 2485of <protocol>. 2486 2487Example: boot from a remote Fedora 20 live ISO image 2488@example 2489qemu-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 2490 2491qemu-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 2492@end example 2493 2494Example: boot from a remote Fedora 20 cloud image using a local overlay for 2495writes, copy-on-read, and a readahead of 64k 2496@example 2497qemu-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 2498 2499qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on 2500@end example 2501 2502Example: boot from an image stored on a VMware vSphere server with a self-signed 2503certificate using a local overlay for writes, a readahead of 64k and a timeout 2504of 10 seconds. 2505@example 2506qemu-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 2507 2508qemu-system-x86_64 -drive file=/tmp/test.qcow2 2509@end example 2510ETEXI 2511 2512STEXI 2513@end table 2514ETEXI 2515 2516DEFHEADING(Bluetooth(R) options:) 2517STEXI 2518@table @option 2519ETEXI 2520 2521DEF("bt", HAS_ARG, QEMU_OPTION_bt, \ 2522 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \ 2523 "-bt hci,host[:id]\n" \ 2524 " use host's HCI with the given name\n" \ 2525 "-bt hci[,vlan=n]\n" \ 2526 " emulate a standard HCI in virtual scatternet 'n'\n" \ 2527 "-bt vhci[,vlan=n]\n" \ 2528 " add host computer to virtual scatternet 'n' using VHCI\n" \ 2529 "-bt device:dev[,vlan=n]\n" \ 2530 " emulate a bluetooth device 'dev' in scatternet 'n'\n", 2531 QEMU_ARCH_ALL) 2532STEXI 2533@item -bt hci[...] 2534@findex -bt 2535Defines the function of the corresponding Bluetooth HCI. -bt options 2536are matched with the HCIs present in the chosen machine type. For 2537example when emulating a machine with only one HCI built into it, only 2538the first @code{-bt hci[...]} option is valid and defines the HCI's 2539logic. The Transport Layer is decided by the machine type. Currently 2540the machines @code{n800} and @code{n810} have one HCI and all other 2541machines have none. 2542 2543@anchor{bt-hcis} 2544The following three types are recognized: 2545 2546@table @option 2547@item -bt hci,null 2548(default) The corresponding Bluetooth HCI assumes no internal logic 2549and will not respond to any HCI commands or emit events. 2550 2551@item -bt hci,host[:@var{id}] 2552(@code{bluez} only) The corresponding HCI passes commands / events 2553to / from the physical HCI identified by the name @var{id} (default: 2554@code{hci0}) on the computer running QEMU. Only available on @code{bluez} 2555capable systems like Linux. 2556 2557@item -bt hci[,vlan=@var{n}] 2558Add a virtual, standard HCI that will participate in the Bluetooth 2559scatternet @var{n} (default @code{0}). Similarly to @option{-net} 2560VLANs, devices inside a bluetooth network @var{n} can only communicate 2561with other devices in the same network (scatternet). 2562@end table 2563 2564@item -bt vhci[,vlan=@var{n}] 2565(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached 2566to the host bluetooth stack instead of to the emulated target. This 2567allows the host and target machines to participate in a common scatternet 2568and communicate. Requires the Linux @code{vhci} driver installed. Can 2569be used as following: 2570 2571@example 2572qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5 2573@end example 2574 2575@item -bt device:@var{dev}[,vlan=@var{n}] 2576Emulate a bluetooth device @var{dev} and place it in network @var{n} 2577(default @code{0}). QEMU can only emulate one type of bluetooth devices 2578currently: 2579 2580@table @option 2581@item keyboard 2582Virtual wireless keyboard implementing the HIDP bluetooth profile. 2583@end table 2584ETEXI 2585 2586STEXI 2587@end table 2588ETEXI 2589DEFHEADING() 2590 2591#ifdef CONFIG_TPM 2592DEFHEADING(TPM device options:) 2593 2594DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \ 2595 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n" 2596 " use path to provide path to a character device; default is /dev/tpm0\n" 2597 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n" 2598 " not provided it will be searched for in /sys/class/misc/tpm?/device\n", 2599 QEMU_ARCH_ALL) 2600STEXI 2601 2602The general form of a TPM device option is: 2603@table @option 2604 2605@item -tpmdev @var{backend} ,id=@var{id} [,@var{options}] 2606@findex -tpmdev 2607Backend type must be: 2608@option{passthrough}. 2609 2610The specific backend type will determine the applicable options. 2611The @code{-tpmdev} option creates the TPM backend and requires a 2612@code{-device} option that specifies the TPM frontend interface model. 2613 2614Options to each backend are described below. 2615 2616Use 'help' to print all available TPM backend types. 2617@example 2618qemu -tpmdev help 2619@end example 2620 2621@item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path} 2622 2623(Linux-host only) Enable access to the host's TPM using the passthrough 2624driver. 2625 2626@option{path} specifies the path to the host's TPM device, i.e., on 2627a Linux host this would be @code{/dev/tpm0}. 2628@option{path} is optional and by default @code{/dev/tpm0} is used. 2629 2630@option{cancel-path} specifies the path to the host TPM device's sysfs 2631entry allowing for cancellation of an ongoing TPM command. 2632@option{cancel-path} is optional and by default QEMU will search for the 2633sysfs entry to use. 2634 2635Some notes about using the host's TPM with the passthrough driver: 2636 2637The TPM device accessed by the passthrough driver must not be 2638used by any other application on the host. 2639 2640Since the host's firmware (BIOS/UEFI) has already initialized the TPM, 2641the VM's firmware (BIOS/UEFI) will not be able to initialize the 2642TPM again and may therefore not show a TPM-specific menu that would 2643otherwise allow the user to configure the TPM, e.g., allow the user to 2644enable/disable or activate/deactivate the TPM. 2645Further, if TPM ownership is released from within a VM then the host's TPM 2646will get disabled and deactivated. To enable and activate the 2647TPM again afterwards, the host has to be rebooted and the user is 2648required to enter the firmware's menu to enable and activate the TPM. 2649If the TPM is left disabled and/or deactivated most TPM commands will fail. 2650 2651To create a passthrough TPM use the following two options: 2652@example 2653-tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0 2654@end example 2655Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by 2656@code{tpmdev=tpm0} in the device option. 2657 2658@end table 2659 2660ETEXI 2661 2662DEFHEADING() 2663 2664#endif 2665 2666DEFHEADING(Linux/Multiboot boot specific:) 2667STEXI 2668 2669When using these options, you can use a given Linux or Multiboot 2670kernel without installing it in the disk image. It can be useful 2671for easier testing of various kernels. 2672 2673@table @option 2674ETEXI 2675 2676DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \ 2677 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL) 2678STEXI 2679@item -kernel @var{bzImage} 2680@findex -kernel 2681Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel 2682or in multiboot format. 2683ETEXI 2684 2685DEF("append", HAS_ARG, QEMU_OPTION_append, \ 2686 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL) 2687STEXI 2688@item -append @var{cmdline} 2689@findex -append 2690Use @var{cmdline} as kernel command line 2691ETEXI 2692 2693DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \ 2694 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL) 2695STEXI 2696@item -initrd @var{file} 2697@findex -initrd 2698Use @var{file} as initial ram disk. 2699 2700@item -initrd "@var{file1} arg=foo,@var{file2}" 2701 2702This syntax is only available with multiboot. 2703 2704Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the 2705first module. 2706ETEXI 2707 2708DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \ 2709 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL) 2710STEXI 2711@item -dtb @var{file} 2712@findex -dtb 2713Use @var{file} as a device tree binary (dtb) image and pass it to the kernel 2714on boot. 2715ETEXI 2716 2717STEXI 2718@end table 2719ETEXI 2720DEFHEADING() 2721 2722DEFHEADING(Debug/Expert options:) 2723STEXI 2724@table @option 2725ETEXI 2726 2727DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, 2728 "-fw_cfg [name=]<name>,file=<file>\n" 2729 " add named fw_cfg entry from file\n" 2730 "-fw_cfg [name=]<name>,string=<str>\n" 2731 " add named fw_cfg entry from string\n", 2732 QEMU_ARCH_ALL) 2733STEXI 2734@item -fw_cfg [name=]@var{name},file=@var{file} 2735@findex -fw_cfg 2736Add named fw_cfg entry from file. @var{name} determines the name of 2737the entry in the fw_cfg file directory exposed to the guest. 2738 2739@item -fw_cfg [name=]@var{name},string=@var{str} 2740Add named fw_cfg entry from string. 2741ETEXI 2742 2743DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ 2744 "-serial dev redirect the serial port to char device 'dev'\n", 2745 QEMU_ARCH_ALL) 2746STEXI 2747@item -serial @var{dev} 2748@findex -serial 2749Redirect the virtual serial port to host character device 2750@var{dev}. The default device is @code{vc} in graphical mode and 2751@code{stdio} in non graphical mode. 2752 2753This option can be used several times to simulate up to 4 serial 2754ports. 2755 2756Use @code{-serial none} to disable all serial ports. 2757 2758Available character devices are: 2759@table @option 2760@item vc[:@var{W}x@var{H}] 2761Virtual console. Optionally, a width and height can be given in pixel with 2762@example 2763vc:800x600 2764@end example 2765It is also possible to specify width or height in characters: 2766@example 2767vc:80Cx24C 2768@end example 2769@item pty 2770[Linux only] Pseudo TTY (a new PTY is automatically allocated) 2771@item none 2772No device is allocated. 2773@item null 2774void device 2775@item chardev:@var{id} 2776Use a named character device defined with the @code{-chardev} option. 2777@item /dev/XXX 2778[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port 2779parameters are set according to the emulated ones. 2780@item /dev/parport@var{N} 2781[Linux only, parallel port only] Use host parallel port 2782@var{N}. Currently SPP and EPP parallel port features can be used. 2783@item file:@var{filename} 2784Write output to @var{filename}. No character can be read. 2785@item stdio 2786[Unix only] standard input/output 2787@item pipe:@var{filename} 2788name pipe @var{filename} 2789@item COM@var{n} 2790[Windows only] Use host serial port @var{n} 2791@item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}] 2792This implements UDP Net Console. 2793When @var{remote_host} or @var{src_ip} are not specified 2794they default to @code{0.0.0.0}. 2795When not using a specified @var{src_port} a random port is automatically chosen. 2796 2797If you just want a simple readonly console you can use @code{netcat} or 2798@code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as: 2799@code{nc -u -l -p 4555}. Any time QEMU writes something to that port it 2800will appear in the netconsole session. 2801 2802If you plan to send characters back via netconsole or you want to stop 2803and start QEMU a lot of times, you should have QEMU use the same 2804source port each time by using something like @code{-serial 2805udp::4555@@:4556} to QEMU. Another approach is to use a patched 2806version of netcat which can listen to a TCP port and send and receive 2807characters via udp. If you have a patched version of netcat which 2808activates telnet remote echo and single char transfer, then you can 2809use the following options to step up a netcat redirector to allow 2810telnet on port 5555 to access the QEMU port. 2811@table @code 2812@item QEMU Options: 2813-serial udp::4555@@:4556 2814@item netcat options: 2815-u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T 2816@item telnet options: 2817localhost 5555 2818@end table 2819 2820@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}] 2821The TCP Net Console has two modes of operation. It can send the serial 2822I/O to a location or wait for a connection from a location. By default 2823the TCP Net Console is sent to @var{host} at the @var{port}. If you use 2824the @var{server} option QEMU will wait for a client socket application 2825to connect to the port before continuing, unless the @code{nowait} 2826option was specified. The @code{nodelay} option disables the Nagle buffering 2827algorithm. The @code{reconnect} option only applies if @var{noserver} is 2828set, if the connection goes down it will attempt to reconnect at the 2829given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only 2830one TCP connection at a time is accepted. You can use @code{telnet} to 2831connect to the corresponding character device. 2832@table @code 2833@item Example to send tcp console to 192.168.0.2 port 4444 2834-serial tcp:192.168.0.2:4444 2835@item Example to listen and wait on port 4444 for connection 2836-serial tcp::4444,server 2837@item Example to not wait and listen on ip 192.168.0.100 port 4444 2838-serial tcp:192.168.0.100:4444,server,nowait 2839@end table 2840 2841@item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay] 2842The telnet protocol is used instead of raw tcp sockets. The options 2843work the same as if you had specified @code{-serial tcp}. The 2844difference is that the port acts like a telnet server or client using 2845telnet option negotiation. This will also allow you to send the 2846MAGIC_SYSRQ sequence if you use a telnet that supports sending the break 2847sequence. Typically in unix telnet you do it with Control-] and then 2848type "send break" followed by pressing the enter key. 2849 2850@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}] 2851A unix domain socket is used instead of a tcp socket. The option works the 2852same as if you had specified @code{-serial tcp} except the unix domain socket 2853@var{path} is used for connections. 2854 2855@item mon:@var{dev_string} 2856This is a special option to allow the monitor to be multiplexed onto 2857another serial port. The monitor is accessed with key sequence of 2858@key{Control-a} and then pressing @key{c}. 2859@var{dev_string} should be any one of the serial devices specified 2860above. An example to multiplex the monitor onto a telnet server 2861listening on port 4444 would be: 2862@table @code 2863@item -serial mon:telnet::4444,server,nowait 2864@end table 2865When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate 2866QEMU any more but will be passed to the guest instead. 2867 2868@item braille 2869Braille device. This will use BrlAPI to display the braille output on a real 2870or fake device. 2871 2872@item msmouse 2873Three button serial mouse. Configure the guest to use Microsoft protocol. 2874@end table 2875ETEXI 2876 2877DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \ 2878 "-parallel dev redirect the parallel port to char device 'dev'\n", 2879 QEMU_ARCH_ALL) 2880STEXI 2881@item -parallel @var{dev} 2882@findex -parallel 2883Redirect the virtual parallel port to host device @var{dev} (same 2884devices as the serial port). On Linux hosts, @file{/dev/parportN} can 2885be used to use hardware devices connected on the corresponding host 2886parallel port. 2887 2888This option can be used several times to simulate up to 3 parallel 2889ports. 2890 2891Use @code{-parallel none} to disable all parallel ports. 2892ETEXI 2893 2894DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \ 2895 "-monitor dev redirect the monitor to char device 'dev'\n", 2896 QEMU_ARCH_ALL) 2897STEXI 2898@item -monitor @var{dev} 2899@findex -monitor 2900Redirect the monitor to host device @var{dev} (same devices as the 2901serial port). 2902The default device is @code{vc} in graphical mode and @code{stdio} in 2903non graphical mode. 2904Use @code{-monitor none} to disable the default monitor. 2905ETEXI 2906DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \ 2907 "-qmp dev like -monitor but opens in 'control' mode\n", 2908 QEMU_ARCH_ALL) 2909STEXI 2910@item -qmp @var{dev} 2911@findex -qmp 2912Like -monitor but opens in 'control' mode. 2913ETEXI 2914DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \ 2915 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n", 2916 QEMU_ARCH_ALL) 2917STEXI 2918@item -qmp-pretty @var{dev} 2919@findex -qmp-pretty 2920Like -qmp but uses pretty JSON formatting. 2921ETEXI 2922 2923DEF("mon", HAS_ARG, QEMU_OPTION_mon, \ 2924 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL) 2925STEXI 2926@item -mon [chardev=]name[,mode=readline|control][,default] 2927@findex -mon 2928Setup monitor on chardev @var{name}. 2929ETEXI 2930 2931DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \ 2932 "-debugcon dev redirect the debug console to char device 'dev'\n", 2933 QEMU_ARCH_ALL) 2934STEXI 2935@item -debugcon @var{dev} 2936@findex -debugcon 2937Redirect the debug console to host device @var{dev} (same devices as the 2938serial port). The debug console is an I/O port which is typically port 29390xe9; writing to that I/O port sends output to this device. 2940The default device is @code{vc} in graphical mode and @code{stdio} in 2941non graphical mode. 2942ETEXI 2943 2944DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \ 2945 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL) 2946STEXI 2947@item -pidfile @var{file} 2948@findex -pidfile 2949Store the QEMU process PID in @var{file}. It is useful if you launch QEMU 2950from a script. 2951ETEXI 2952 2953DEF("singlestep", 0, QEMU_OPTION_singlestep, \ 2954 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL) 2955STEXI 2956@item -singlestep 2957@findex -singlestep 2958Run the emulation in single step mode. 2959ETEXI 2960 2961DEF("S", 0, QEMU_OPTION_S, \ 2962 "-S freeze CPU at startup (use 'c' to start execution)\n", 2963 QEMU_ARCH_ALL) 2964STEXI 2965@item -S 2966@findex -S 2967Do not start CPU at startup (you must type 'c' in the monitor). 2968ETEXI 2969 2970DEF("realtime", HAS_ARG, QEMU_OPTION_realtime, 2971 "-realtime [mlock=on|off]\n" 2972 " run qemu with realtime features\n" 2973 " mlock=on|off controls mlock support (default: on)\n", 2974 QEMU_ARCH_ALL) 2975STEXI 2976@item -realtime mlock=on|off 2977@findex -realtime 2978Run qemu with realtime features. 2979mlocking qemu and guest memory can be enabled via @option{mlock=on} 2980(enabled by default). 2981ETEXI 2982 2983DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \ 2984 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL) 2985STEXI 2986@item -gdb @var{dev} 2987@findex -gdb 2988Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical 2989connections will likely be TCP-based, but also UDP, pseudo TTY, or even 2990stdio are reasonable use case. The latter is allowing to start QEMU from 2991within gdb and establish the connection via a pipe: 2992@example 2993(gdb) target remote | exec qemu-system-i386 -gdb stdio ... 2994@end example 2995ETEXI 2996 2997DEF("s", 0, QEMU_OPTION_s, \ 2998 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n", 2999 QEMU_ARCH_ALL) 3000STEXI 3001@item -s 3002@findex -s 3003Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234 3004(@pxref{gdb_usage}). 3005ETEXI 3006 3007DEF("d", HAS_ARG, QEMU_OPTION_d, \ 3008 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n", 3009 QEMU_ARCH_ALL) 3010STEXI 3011@item -d @var{item1}[,...] 3012@findex -d 3013Enable logging of specified items. Use '-d help' for a list of log items. 3014ETEXI 3015 3016DEF("D", HAS_ARG, QEMU_OPTION_D, \ 3017 "-D logfile output log to logfile (default stderr)\n", 3018 QEMU_ARCH_ALL) 3019STEXI 3020@item -D @var{logfile} 3021@findex -D 3022Output log in @var{logfile} instead of to stderr 3023ETEXI 3024 3025DEF("L", HAS_ARG, QEMU_OPTION_L, \ 3026 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n", 3027 QEMU_ARCH_ALL) 3028STEXI 3029@item -L @var{path} 3030@findex -L 3031Set the directory for the BIOS, VGA BIOS and keymaps. 3032ETEXI 3033 3034DEF("bios", HAS_ARG, QEMU_OPTION_bios, \ 3035 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL) 3036STEXI 3037@item -bios @var{file} 3038@findex -bios 3039Set the filename for the BIOS. 3040ETEXI 3041 3042DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \ 3043 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL) 3044STEXI 3045@item -enable-kvm 3046@findex -enable-kvm 3047Enable KVM full virtualization support. This option is only available 3048if KVM support is enabled when compiling. 3049ETEXI 3050 3051DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid, 3052 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL) 3053DEF("xen-create", 0, QEMU_OPTION_xen_create, 3054 "-xen-create create domain using xen hypercalls, bypassing xend\n" 3055 " warning: should not be used when xend is in use\n", 3056 QEMU_ARCH_ALL) 3057DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 3058 "-xen-attach attach to existing xen domain\n" 3059 " xend will use this when starting QEMU\n", 3060 QEMU_ARCH_ALL) 3061STEXI 3062@item -xen-domid @var{id} 3063@findex -xen-domid 3064Specify xen guest domain @var{id} (XEN only). 3065@item -xen-create 3066@findex -xen-create 3067Create domain using xen hypercalls, bypassing xend. 3068Warning: should not be used when xend is in use (XEN only). 3069@item -xen-attach 3070@findex -xen-attach 3071Attach to existing xen domain. 3072xend will use this when starting QEMU (XEN only). 3073ETEXI 3074 3075DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \ 3076 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL) 3077STEXI 3078@item -no-reboot 3079@findex -no-reboot 3080Exit instead of rebooting. 3081ETEXI 3082 3083DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \ 3084 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL) 3085STEXI 3086@item -no-shutdown 3087@findex -no-shutdown 3088Don't exit QEMU on guest shutdown, but instead only stop the emulation. 3089This allows for instance switching to monitor to commit changes to the 3090disk image. 3091ETEXI 3092 3093DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \ 3094 "-loadvm [tag|id]\n" \ 3095 " start right away with a saved state (loadvm in monitor)\n", 3096 QEMU_ARCH_ALL) 3097STEXI 3098@item -loadvm @var{file} 3099@findex -loadvm 3100Start right away with a saved state (@code{loadvm} in monitor) 3101ETEXI 3102 3103#ifndef _WIN32 3104DEF("daemonize", 0, QEMU_OPTION_daemonize, \ 3105 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL) 3106#endif 3107STEXI 3108@item -daemonize 3109@findex -daemonize 3110Daemonize the QEMU process after initialization. QEMU will not detach from 3111standard IO until it is ready to receive connections on any of its devices. 3112This option is a useful way for external programs to launch QEMU without having 3113to cope with initialization race conditions. 3114ETEXI 3115 3116DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \ 3117 "-option-rom rom load a file, rom, into the option ROM space\n", 3118 QEMU_ARCH_ALL) 3119STEXI 3120@item -option-rom @var{file} 3121@findex -option-rom 3122Load the contents of @var{file} as an option ROM. 3123This option is useful to load things like EtherBoot. 3124ETEXI 3125 3126HXCOMM Silently ignored for compatibility 3127DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) 3128 3129HXCOMM Options deprecated by -rtc 3130DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL) 3131DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL) 3132 3133DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ 3134 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \ 3135 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n", 3136 QEMU_ARCH_ALL) 3137 3138STEXI 3139 3140@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew] 3141@findex -rtc 3142Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current 3143UTC or local time, respectively. @code{localtime} is required for correct date in 3144MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the 3145format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC. 3146 3147By default the RTC is driven by the host system time. This allows using of the 3148RTC as accurate reference clock inside the guest, specifically if the host 3149time is smoothly following an accurate external reference clock, e.g. via NTP. 3150If you want to isolate the guest time from the host, you can set @option{clock} 3151to @code{rt} instead. To even prevent it from progressing during suspension, 3152you can set it to @code{vm}. 3153 3154Enable @option{driftfix} (i386 targets only) if you experience time drift problems, 3155specifically with Windows' ACPI HAL. This option will try to figure out how 3156many timer interrupts were not processed by the Windows guest and will 3157re-inject them. 3158ETEXI 3159 3160DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ 3161 "-icount [shift=N|auto][,align=on|off][,sleep=no,rr=record|replay,rrfile=<filename>]\n" \ 3162 " enable virtual instruction counter with 2^N clock ticks per\n" \ 3163 " instruction, enable aligning the host and virtual clocks\n" \ 3164 " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) 3165STEXI 3166@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}] 3167@findex -icount 3168Enable virtual instruction counter. The virtual cpu will execute one 3169instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified 3170then the virtual cpu speed will be automatically adjusted to keep virtual 3171time within a few seconds of real time. 3172 3173When the virtual cpu is sleeping, the virtual time will advance at default 3174speed unless @option{sleep=no} is specified. 3175With @option{sleep=no}, the virtual time will jump to the next timer deadline 3176instantly whenever the virtual cpu goes to sleep mode and will not advance 3177if no timer is enabled. This behavior give deterministic execution times from 3178the guest point of view. 3179 3180Note that while this option can give deterministic behavior, it does not 3181provide cycle accurate emulation. Modern CPUs contain superscalar out of 3182order cores with complex cache hierarchies. The number of instructions 3183executed often has little or no correlation with actual performance. 3184 3185@option{align=on} will activate the delay algorithm which will try 3186to synchronise the host clock and the virtual clock. The goal is to 3187have a guest running at the real frequency imposed by the shift option. 3188Whenever the guest clock is behind the host clock and if 3189@option{align=on} is specified then we print a message to the user 3190to inform about the delay. 3191Currently this option does not work when @option{shift} is @code{auto}. 3192Note: The sync algorithm will work for those shift values for which 3193the guest clock runs ahead of the host clock. Typically this happens 3194when the shift value is high (how high depends on the host machine). 3195 3196When @option{rr} option is specified deterministic record/replay is enabled. 3197Replay log is written into @var{filename} file in record mode and 3198read from this file in replay mode. 3199ETEXI 3200 3201DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ 3202 "-watchdog model\n" \ 3203 " enable virtual hardware watchdog [default=none]\n", 3204 QEMU_ARCH_ALL) 3205STEXI 3206@item -watchdog @var{model} 3207@findex -watchdog 3208Create a virtual hardware watchdog device. Once enabled (by a guest 3209action), the watchdog must be periodically polled by an agent inside 3210the guest or else the guest will be restarted. Choose a model for 3211which your guest has drivers. 3212 3213The @var{model} is the model of hardware watchdog to emulate. Use 3214@code{-watchdog help} to list available hardware models. Only one 3215watchdog can be enabled for a guest. 3216 3217The following models may be available: 3218@table @option 3219@item ib700 3220iBASE 700 is a very simple ISA watchdog with a single timer. 3221@item i6300esb 3222Intel 6300ESB I/O controller hub is a much more featureful PCI-based 3223dual-timer watchdog. 3224@item diag288 3225A virtual watchdog for s390x backed by the diagnose 288 hypercall 3226(currently KVM only). 3227@end table 3228ETEXI 3229 3230DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ 3231 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \ 3232 " action when watchdog fires [default=reset]\n", 3233 QEMU_ARCH_ALL) 3234STEXI 3235@item -watchdog-action @var{action} 3236@findex -watchdog-action 3237 3238The @var{action} controls what QEMU will do when the watchdog timer 3239expires. 3240The default is 3241@code{reset} (forcefully reset the guest). 3242Other possible actions are: 3243@code{shutdown} (attempt to gracefully shutdown the guest), 3244@code{poweroff} (forcefully poweroff the guest), 3245@code{pause} (pause the guest), 3246@code{debug} (print a debug message and continue), or 3247@code{none} (do nothing). 3248 3249Note that the @code{shutdown} action requires that the guest responds 3250to ACPI signals, which it may not be able to do in the sort of 3251situations where the watchdog would have expired, and thus 3252@code{-watchdog-action shutdown} is not recommended for production use. 3253 3254Examples: 3255 3256@table @code 3257@item -watchdog i6300esb -watchdog-action pause 3258@itemx -watchdog ib700 3259@end table 3260ETEXI 3261 3262DEF("echr", HAS_ARG, QEMU_OPTION_echr, \ 3263 "-echr chr set terminal escape character instead of ctrl-a\n", 3264 QEMU_ARCH_ALL) 3265STEXI 3266 3267@item -echr @var{numeric_ascii_value} 3268@findex -echr 3269Change the escape character used for switching to the monitor when using 3270monitor and serial sharing. The default is @code{0x01} when using the 3271@code{-nographic} option. @code{0x01} is equal to pressing 3272@code{Control-a}. You can select a different character from the ascii 3273control keys where 1 through 26 map to Control-a through Control-z. For 3274instance you could use the either of the following to change the escape 3275character to Control-t. 3276@table @code 3277@item -echr 0x14 3278@itemx -echr 20 3279@end table 3280ETEXI 3281 3282DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \ 3283 "-virtioconsole c\n" \ 3284 " set virtio console\n", QEMU_ARCH_ALL) 3285STEXI 3286@item -virtioconsole @var{c} 3287@findex -virtioconsole 3288Set virtio console. 3289 3290This option is maintained for backward compatibility. 3291 3292Please use @code{-device virtconsole} for the new way of invocation. 3293ETEXI 3294 3295DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \ 3296 "-show-cursor show cursor\n", QEMU_ARCH_ALL) 3297STEXI 3298@item -show-cursor 3299@findex -show-cursor 3300Show cursor. 3301ETEXI 3302 3303DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \ 3304 "-tb-size n set TB size\n", QEMU_ARCH_ALL) 3305STEXI 3306@item -tb-size @var{n} 3307@findex -tb-size 3308Set TB size. 3309ETEXI 3310 3311DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ 3312 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \ 3313 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \ 3314 "-incoming unix:socketpath\n" \ 3315 " prepare for incoming migration, listen on\n" \ 3316 " specified protocol and socket address\n" \ 3317 "-incoming fd:fd\n" \ 3318 "-incoming exec:cmdline\n" \ 3319 " accept incoming migration on given file descriptor\n" \ 3320 " or from given external command\n" \ 3321 "-incoming defer\n" \ 3322 " wait for the URI to be specified via migrate_incoming\n", 3323 QEMU_ARCH_ALL) 3324STEXI 3325@item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6] 3326@itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6] 3327@findex -incoming 3328Prepare for incoming migration, listen on a given tcp port. 3329 3330@item -incoming unix:@var{socketpath} 3331Prepare for incoming migration, listen on a given unix socket. 3332 3333@item -incoming fd:@var{fd} 3334Accept incoming migration from a given filedescriptor. 3335 3336@item -incoming exec:@var{cmdline} 3337Accept incoming migration as an output from specified external command. 3338 3339@item -incoming defer 3340Wait for the URI to be specified via migrate_incoming. The monitor can 3341be used to change settings (such as migration parameters) prior to issuing 3342the migrate_incoming to allow the migration to begin. 3343ETEXI 3344 3345DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \ 3346 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL) 3347STEXI 3348@item -nodefaults 3349@findex -nodefaults 3350Don't create default devices. Normally, QEMU sets the default devices like serial 3351port, parallel port, virtual console, monitor device, VGA adapter, floppy and 3352CD-ROM drive and others. The @code{-nodefaults} option will disable all those 3353default devices. 3354ETEXI 3355 3356#ifndef _WIN32 3357DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \ 3358 "-chroot dir chroot to dir just before starting the VM\n", 3359 QEMU_ARCH_ALL) 3360#endif 3361STEXI 3362@item -chroot @var{dir} 3363@findex -chroot 3364Immediately before starting guest execution, chroot to the specified 3365directory. Especially useful in combination with -runas. 3366ETEXI 3367 3368#ifndef _WIN32 3369DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ 3370 "-runas user change to user id user just before starting the VM\n", 3371 QEMU_ARCH_ALL) 3372#endif 3373STEXI 3374@item -runas @var{user} 3375@findex -runas 3376Immediately before starting guest execution, drop root privileges, switching 3377to the specified user. 3378ETEXI 3379 3380DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, 3381 "-prom-env variable=value\n" 3382 " set OpenBIOS nvram variables\n", 3383 QEMU_ARCH_PPC | QEMU_ARCH_SPARC) 3384STEXI 3385@item -prom-env @var{variable}=@var{value} 3386@findex -prom-env 3387Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only). 3388ETEXI 3389DEF("semihosting", 0, QEMU_OPTION_semihosting, 3390 "-semihosting semihosting mode\n", 3391 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3392 QEMU_ARCH_MIPS) 3393STEXI 3394@item -semihosting 3395@findex -semihosting 3396Enable semihosting mode (ARM, M68K, Xtensa, MIPS only). 3397ETEXI 3398DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config, 3399 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \ 3400 " semihosting configuration\n", 3401QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 | 3402QEMU_ARCH_MIPS) 3403STEXI 3404@item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]] 3405@findex -semihosting-config 3406Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only). 3407@table @option 3408@item target=@code{native|gdb|auto} 3409Defines where the semihosting calls will be addressed, to QEMU (@code{native}) 3410or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb} 3411during debug sessions and @code{native} otherwise. 3412@item arg=@var{str1},arg=@var{str2},... 3413Allows the user to pass input arguments, and can be used multiple times to build 3414up a list. The old-style @code{-kernel}/@code{-append} method of passing a 3415command line is still supported for backward compatibility. If both the 3416@code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are 3417specified, the former is passed to semihosting as it always takes precedence. 3418@end table 3419ETEXI 3420DEF("old-param", 0, QEMU_OPTION_old_param, 3421 "-old-param old param mode\n", QEMU_ARCH_ARM) 3422STEXI 3423@item -old-param 3424@findex -old-param (ARM) 3425Old param mode (ARM only). 3426ETEXI 3427 3428DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ 3429 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", 3430 QEMU_ARCH_ALL) 3431STEXI 3432@item -sandbox @var{arg} 3433@findex -sandbox 3434Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will 3435disable it. The default is 'off'. 3436ETEXI 3437 3438DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, 3439 "-readconfig <file>\n", QEMU_ARCH_ALL) 3440STEXI 3441@item -readconfig @var{file} 3442@findex -readconfig 3443Read device configuration from @var{file}. This approach is useful when you want to spawn 3444QEMU process with many command line options but you don't want to exceed the command line 3445character limit. 3446ETEXI 3447DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig, 3448 "-writeconfig <file>\n" 3449 " read/write config file\n", QEMU_ARCH_ALL) 3450STEXI 3451@item -writeconfig @var{file} 3452@findex -writeconfig 3453Write device configuration to @var{file}. The @var{file} can be either filename to save 3454command line and device configuration into file or dash @code{-}) character to print the 3455output to stdout. This can be later used as input file for @code{-readconfig} option. 3456ETEXI 3457DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig, 3458 "-nodefconfig\n" 3459 " do not load default config files at startup\n", 3460 QEMU_ARCH_ALL) 3461STEXI 3462@item -nodefconfig 3463@findex -nodefconfig 3464Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup. 3465The @code{-nodefconfig} option will prevent QEMU from loading any of those config files. 3466ETEXI 3467DEF("no-user-config", 0, QEMU_OPTION_nouserconfig, 3468 "-no-user-config\n" 3469 " do not load user-provided config files at startup\n", 3470 QEMU_ARCH_ALL) 3471STEXI 3472@item -no-user-config 3473@findex -no-user-config 3474The @code{-no-user-config} option makes QEMU not load any of the user-provided 3475config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config 3476files from @var{datadir}. 3477ETEXI 3478DEF("trace", HAS_ARG, QEMU_OPTION_trace, 3479 "-trace [events=<file>][,file=<file>]\n" 3480 " specify tracing options\n", 3481 QEMU_ARCH_ALL) 3482STEXI 3483HXCOMM This line is not accurate, as some sub-options are backend-specific but 3484HXCOMM HX does not support conditional compilation of text. 3485@item -trace [events=@var{file}][,file=@var{file}] 3486@findex -trace 3487 3488Specify tracing options. 3489 3490@table @option 3491@item events=@var{file} 3492Immediately enable events listed in @var{file}. 3493The file must contain one event name (as listed in the @var{trace-events} file) 3494per line. 3495This option is only available if QEMU has been compiled with 3496either @var{simple} or @var{stderr} tracing backend. 3497@item file=@var{file} 3498Log output traces to @var{file}. 3499 3500This option is only available if QEMU has been compiled with 3501the @var{simple} tracing backend. 3502@end table 3503ETEXI 3504 3505HXCOMM Internal use 3506DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL) 3507DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) 3508 3509#ifdef __linux__ 3510DEF("enable-fips", 0, QEMU_OPTION_enablefips, 3511 "-enable-fips enable FIPS 140-2 compliance\n", 3512 QEMU_ARCH_ALL) 3513#endif 3514STEXI 3515@item -enable-fips 3516@findex -enable-fips 3517Enable FIPS 140-2 compliance mode. 3518ETEXI 3519 3520HXCOMM Deprecated by -machine accel=tcg property 3521DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386) 3522 3523HXCOMM Deprecated by kvm-pit driver properties 3524DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection, 3525 "", QEMU_ARCH_I386) 3526 3527HXCOMM Deprecated (ignored) 3528DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386) 3529 3530HXCOMM Deprecated by -machine kernel_irqchip=on|off property 3531DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386) 3532 3533HXCOMM Deprecated (ignored) 3534DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL) 3535 3536DEF("msg", HAS_ARG, QEMU_OPTION_msg, 3537 "-msg timestamp[=on|off]\n" 3538 " change the format of messages\n" 3539 " on|off controls leading timestamps (default:on)\n", 3540 QEMU_ARCH_ALL) 3541STEXI 3542@item -msg timestamp[=on|off] 3543@findex -msg 3544prepend a timestamp to each log message.(default:on) 3545ETEXI 3546 3547DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate, 3548 "-dump-vmstate <file>\n" 3549 " Output vmstate information in JSON format to file.\n" 3550 " Use the scripts/vmstate-static-checker.py file to\n" 3551 " check for possible regressions in migration code\n" 3552 " by comparing two such vmstate dumps.\n", 3553 QEMU_ARCH_ALL) 3554STEXI 3555@item -dump-vmstate @var{file} 3556@findex -dump-vmstate 3557Dump json-encoded vmstate information for current machine type to file 3558in @var{file} 3559ETEXI 3560 3561DEFHEADING(Generic object creation) 3562 3563DEF("object", HAS_ARG, QEMU_OPTION_object, 3564 "-object TYPENAME[,PROP1=VALUE1,...]\n" 3565 " create a new object of type TYPENAME setting properties\n" 3566 " in the order they are specified. Note that the 'id'\n" 3567 " property must be set. These objects are placed in the\n" 3568 " '/objects' path.\n", 3569 QEMU_ARCH_ALL) 3570STEXI 3571@item -object @var{typename}[,@var{prop1}=@var{value1},...] 3572@findex -object 3573Create a new object of type @var{typename} setting properties 3574in the order they are specified. Note that the 'id' 3575property must be set. These objects are placed in the 3576'/objects' path. 3577 3578@table @option 3579 3580@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off} 3581 3582Creates a memory file backend object, which can be used to back 3583the guest RAM with huge pages. The @option{id} parameter is a 3584unique ID that will be used to reference this memory region 3585when configuring the @option{-numa} argument. The @option{size} 3586option provides the size of the memory region, and accepts 3587common suffixes, eg @option{500M}. The @option{mem-path} provides 3588the path to either a shared memory or huge page filesystem mount. 3589The @option{share} boolean option determines whether the memory 3590region is marked as private to QEMU, or shared. The latter allows 3591a co-operating external process to access the QEMU memory region. 3592 3593@item -object rng-random,id=@var{id},filename=@var{/dev/random} 3594 3595Creates a random number generator backend which obtains entropy from 3596a device on the host. The @option{id} parameter is a unique ID that 3597will be used to reference this entropy backend from the @option{virtio-rng} 3598device. The @option{filename} parameter specifies which file to obtain 3599entropy from and if omitted defaults to @option{/dev/random}. 3600 3601@item -object rng-egd,id=@var{id},chardev=@var{chardevid} 3602 3603Creates a random number generator backend which obtains entropy from 3604an external daemon running on the host. The @option{id} parameter is 3605a unique ID that will be used to reference this entropy backend from 3606the @option{virtio-rng} device. The @option{chardev} parameter is 3607the unique ID of a character device backend that provides the connection 3608to the RNG daemon. 3609 3610@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 3611 3612Creates a TLS anonymous credentials object, which can be used to provide 3613TLS support on network backends. The @option{id} parameter is a unique 3614ID which network backends will use to access the credentials. The 3615@option{endpoint} is either @option{server} or @option{client} depending 3616on whether the QEMU network backend that uses the credentials will be 3617acting as a client or as a server. If @option{verify-peer} is enabled 3618(the default) then once the handshake is completed, the peer credentials 3619will be verified, though this is a no-op for anonymous credentials. 3620 3621The @var{dir} parameter tells QEMU where to find the credential 3622files. For server endpoints, this directory may contain a file 3623@var{dh-params.pem} providing diffie-hellman parameters to use 3624for the TLS server. If the file is missing, QEMU will generate 3625a set of DH parameters at startup. This is a computationally 3626expensive operation that consumes random pool entropy, so it is 3627recommended that a persistent set of parameters be generated 3628upfront and saved. 3629 3630@item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off} 3631 3632Creates a TLS anonymous credentials object, which can be used to provide 3633TLS support on network backends. The @option{id} parameter is a unique 3634ID which network backends will use to access the credentials. The 3635@option{endpoint} is either @option{server} or @option{client} depending 3636on whether the QEMU network backend that uses the credentials will be 3637acting as a client or as a server. If @option{verify-peer} is enabled 3638(the default) then once the handshake is completed, the peer credentials 3639will be verified. With x509 certificates, this implies that the clients 3640must be provided with valid client certificates too. 3641 3642The @var{dir} parameter tells QEMU where to find the credential 3643files. For server endpoints, this directory may contain a file 3644@var{dh-params.pem} providing diffie-hellman parameters to use 3645for the TLS server. If the file is missing, QEMU will generate 3646a set of DH parameters at startup. This is a computationally 3647expensive operation that consumes random pool entropy, so it is 3648recommended that a persistent set of parameters be generated 3649upfront and saved. 3650 3651For x509 certificate credentials the directory will contain further files 3652providing the x509 certificates. The certificates must be stored 3653in PEM format, in filenames @var{ca-cert.pem}, @var{ca-crl.pem} (optional), 3654@var{server-cert.pem} (only servers), @var{server-key.pem} (only servers), 3655@var{client-cert.pem} (only clients), and @var{client-key.pem} (only clients). 3656 3657@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}] 3658 3659Interval @var{t} can't be 0, this filter batches the packet delivery: all 3660packets arriving in a given interval on netdev @var{netdevid} are delayed 3661until the end of the interval. Interval is in microseconds. 3662 3663queue @var{all|rx|tx} is an option that can be applied to any netfilter. 3664 3665@option{all}: the filter is attached both to the receive and the transmit 3666 queue of the netdev (default). 3667 3668@option{rx}: the filter is attached to the receive queue of the netdev, 3669 where it will receive packets sent to the netdev. 3670 3671@option{tx}: the filter is attached to the transmit queue of the netdev, 3672 where it will receive packets sent by the netdev. 3673 3674@item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}] 3675 3676Dump the network traffic on netdev @var{dev} to the file specified by 3677@var{filename}. At most @var{len} bytes (64k by default) per packet are stored. 3678The file format is libpcap, so it can be analyzed with tools such as tcpdump 3679or Wireshark. 3680 3681@item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 3682@item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}] 3683 3684Defines a secret to store a password, encryption key, or some other sensitive 3685data. The sensitive data can either be passed directly via the @var{data} 3686parameter, or indirectly via the @var{file} parameter. Using the @var{data} 3687parameter is insecure unless the sensitive data is encrypted. 3688 3689The sensitive data can be provided in raw format (the default), or base64. 3690When encoded as JSON, the raw format only supports valid UTF-8 characters, 3691so base64 is recommended for sending binary data. QEMU will convert from 3692which ever format is provided to the format it needs internally. eg, an 3693RBD password can be provided in raw format, even though it will be base64 3694encoded when passed onto the RBD sever. 3695 3696For added protection, it is possible to encrypt the data associated with 3697a secret using the AES-256-CBC cipher. Use of encryption is indicated 3698by providing the @var{keyid} and @var{iv} parameters. The @var{keyid} 3699parameter provides the ID of a previously defined secret that contains 3700the AES-256 decryption key. This key should be 32-bytes long and be 3701base64 encoded. The @var{iv} parameter provides the random initialization 3702vector used for encryption of this particular secret and should be a 3703base64 encrypted string of the 32-byte IV. 3704 3705The simplest (insecure) usage is to provide the secret inline 3706 3707@example 3708 3709 # $QEMU -object secret,id=sec0,data=letmein,format=raw 3710 3711@end example 3712 3713The simplest secure usage is to provide the secret via a file 3714 3715 # echo -n "letmein" > mypasswd.txt 3716 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw 3717 3718For greater security, AES-256-CBC should be used. To illustrate usage, 3719consider the openssl command line tool which can encrypt the data. Note 3720that when encrypting, the plaintext must be padded to the cipher block 3721size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm. 3722 3723First a master key needs to be created in base64 encoding: 3724 3725@example 3726 # openssl rand -base64 32 > key.b64 3727 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') 3728@end example 3729 3730Each secret to be encrypted needs to have a random initialization vector 3731generated. These do not need to be kept secret 3732 3733@example 3734 # openssl rand -base64 16 > iv.b64 3735 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') 3736@end example 3737 3738The secret to be defined can now be encrypted, in this case we're 3739telling openssl to base64 encode the result, but it could be left 3740as raw bytes if desired. 3741 3742@example 3743 # SECRET=$(echo -n "letmein" | 3744 openssl enc -aes-256-cbc -a -K $KEY -iv $IV) 3745@end example 3746 3747When launching QEMU, create a master secret pointing to @code{key.b64} 3748and specify that to be used to decrypt the user password. Pass the 3749contents of @code{iv.b64} to the second secret 3750 3751@example 3752 # $QEMU \ 3753 -object secret,id=secmaster0,format=base64,file=key.b64 \ 3754 -object secret,id=sec0,keyid=secmaster0,format=base64,\ 3755 data=$SECRET,iv=$(<iv.b64) 3756@end example 3757 3758@end table 3759 3760ETEXI 3761 3762 3763HXCOMM This is the last statement. Insert new options before this line! 3764STEXI 3765@end table 3766ETEXI 3767
