1 HXCOMM Use DEFHEADING() to define headings in both help text and texi
2 HXCOMM Text between STEXI and ETEXI are copied to texi version and
3 HXCOMM discarded from C version
4 HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to
5 HXCOMM construct option structures, enums and help message for specified
7 HXCOMM HXCOMM can be used for comments, discarded from both texi and C
9 DEFHEADING(Standard options:)
14 DEF("help", 0, QEMU_OPTION_h,
15 "-h or -help display this help and exit\n", QEMU_ARCH_ALL)
22 DEF("version", 0, QEMU_OPTION_version,
23 "-version display version information and exit\n", QEMU_ARCH_ALL)
27 Display version information and exit
30 DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
31 "-machine [type=]name[,prop[=value][,...]]\n"
32 " selects emulated machine ('-machine help' for list)\n"
33 " property accel=accel1[:accel2[:...]] selects accelerator\n"
34 " supported accelerators are kvm, xen, tcg (default: tcg)\n"
35 " kernel_irqchip=on|off controls accelerated irqchip support\n"
36 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
37 " kvm_shadow_mem=size of KVM shadow MMU\n"
38 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
39 " mem-merge=on|off controls memory merge support (default: on)\n"
40 " iommu=on|off controls emulated Intel IOMMU (VT-d) support (default=off)\n"
41 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
42 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
43 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n",
46 @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
48 Select the emulated machine by @var{name}. Use @code{-machine help} to list
49 available machines. Supported machine properties are:
51 @item accel=@var{accels1}[:@var{accels2}[:...]]
52 This is used to enable an accelerator. Depending on the target architecture,
53 kvm, xen, or tcg can be available. By default, tcg is used. If there is more
54 than one accelerator specified, the next one is used if the previous one fails
56 @item kernel_irqchip=on|off
57 Enables in-kernel irqchip support for the chosen accelerator when available.
58 @item vmport=on|off|auto
59 Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
60 value based on accel. For accel=xen the default is off otherwise the default
62 @item kvm_shadow_mem=size
63 Defines the size of the KVM shadow MMU.
64 @item dump-guest-core=on|off
65 Include guest memory in a core dump. The default is on.
66 @item mem-merge=on|off
67 Enables or disables memory merge support. This feature, when supported by
68 the host, de-duplicates identical memory pages among VMs instances
71 Enables or disables emulated Intel IOMMU (VT-d) support. The default is off.
72 @item aes-key-wrap=on|off
73 Enables or disables AES key wrapping support on s390-ccw hosts. This feature
74 controls whether AES wrapping keys will be created to allow
75 execution of AES cryptographic functions. The default is on.
76 @item dea-key-wrap=on|off
77 Enables or disables DEA key wrapping support on s390-ccw hosts. This feature
78 controls whether DEA wrapping keys will be created to allow
79 execution of DEA cryptographic functions. The default is on.
83 HXCOMM Deprecated by -machine
84 DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
86 DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
87 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
89 @item -cpu @var{model}
91 Select CPU model (@code{-cpu help} for list and additional feature selection)
94 DEF("smp", HAS_ARG, QEMU_OPTION_smp,
95 "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
96 " set the number of CPUs to 'n' [default=1]\n"
97 " maxcpus= maximum number of total cpus, including\n"
98 " offline CPUs for hotplug, etc\n"
99 " cores= number of CPU cores on one socket\n"
100 " threads= number of threads on one CPU core\n"
101 " sockets= number of discrete sockets in the system\n",
104 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
106 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
107 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
109 For the PC target, the number of @var{cores} per socket, the number
110 of @var{threads} per cores and the total number of @var{sockets} can be
111 specified. Missing values will be computed. If any on the three values is
112 given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
113 specifies the maximum number of hotpluggable CPUs.
116 DEF("numa", HAS_ARG, QEMU_OPTION_numa,
117 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n"
118 "-numa node[,memdev=id][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL)
120 @item -numa node[,mem=@var{size}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}]
121 @itemx -numa node[,memdev=@var{id}][,cpus=@var{cpu[-cpu]}][,nodeid=@var{node}]
123 Simulate a multi node NUMA system. If @samp{mem}, @samp{memdev}
124 and @samp{cpus} are omitted, resources are split equally. Also, note
125 that the -@option{numa} option doesn't allocate any of the specified
126 resources. That is, it just assigns existing resources to NUMA nodes. This
127 means that one still has to use the @option{-m}, @option{-smp} options
128 to allocate RAM and VCPUs respectively, and possibly @option{-object}
129 to specify the memory backend for the @samp{memdev} suboption.
131 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
132 node uses @samp{memdev}, all of them have to use it.
135 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
136 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
137 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
139 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
142 Add a file descriptor to an fd set. Valid options are:
146 This option defines the file descriptor of which a duplicate is added to fd set.
147 The file descriptor cannot be stdin, stdout, or stderr.
149 This option defines the ID of the fd set to add the file descriptor to.
150 @item opaque=@var{opaque}
151 This option defines a free-form string that can be used to describe @var{fd}.
154 You can open an image using pre-opened file descriptors from an fd set:
157 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
158 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
159 -drive file=/dev/fdset/2,index=0,media=disk
163 DEF("set", HAS_ARG, QEMU_OPTION_set,
164 "-set group.id.arg=value\n"
165 " set <arg> parameter for item <id> of type <group>\n"
166 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
168 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
170 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
173 DEF("global", HAS_ARG, QEMU_OPTION_global,
174 "-global driver.property=value\n"
175 "-global driver=driver,property=property,value=value\n"
176 " set a global default for a driver property\n",
179 @item -global @var{driver}.@var{prop}=@var{value}
180 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
182 Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
185 qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk
188 In particular, you can use this to set driver properties for devices which are
189 created automatically by the machine model. To create a device which is not
190 created automatically and set properties on it, use -@option{device}.
192 -global @var{driver}.@var{prop}=@var{value} is shorthand for -global
193 driver=@var{driver},property=@var{prop},value=@var{value}. The
194 longhand syntax works even when @var{driver} contains a dot.
197 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
198 "-boot [order=drives][,once=drives][,menu=on|off]\n"
199 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
200 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
201 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
202 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
203 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
206 @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]
208 Specify boot order @var{drives} as a string of drive letters. Valid
209 drive letters depend on the target architecture. The x86 PC uses: a, b
210 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
211 from network adapter 1-4), hard disk boot is the default. To apply a
212 particular boot order only on the first startup, specify it via
215 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
216 as firmware/BIOS supports them. The default is non-interactive boot.
218 A splash picture could be passed to bios, enabling user to show it as logo,
219 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
220 supports them. Currently Seabios for X86 system support it.
221 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
222 format(true color). The resolution should be supported by the SVGA mode, so
223 the recommended is 320x240, 640x480, 800x640.
225 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
226 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
227 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
230 Do strict boot via @option{strict=on} as far as firmware/BIOS
231 supports it. This only effects when boot priority is changed by
232 bootindex options. The default is non-strict boot.
235 # try to boot from network first, then from hard disk
236 qemu-system-i386 -boot order=nc
237 # boot from CD-ROM first, switch back to default order after reboot
238 qemu-system-i386 -boot once=d
239 # boot with a splash picture for 5 seconds.
240 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
243 Note: The legacy format '-boot @var{drives}' is still supported but its
244 use is discouraged as it may be removed from future versions.
247 DEF("m", HAS_ARG, QEMU_OPTION_m,
248 "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
249 " configure guest RAM\n"
250 " size: initial amount of guest memory\n"
251 " slots: number of hotplug slots (default: none)\n"
252 " maxmem: maximum amount of guest memory (default: none)\n"
253 "NOTE: Some architectures might enforce a specific granularity\n",
256 @item -m [size=]@var{megs}[,slots=n,maxmem=size]
258 Sets guest startup RAM size to @var{megs} megabytes. Default is 128 MiB.
259 Optionally, a suffix of ``M'' or ``G'' can be used to signify a value in
260 megabytes or gigabytes respectively. Optional pair @var{slots}, @var{maxmem}
261 could be used to set amount of hotpluggable memory slots and maximum amount of
262 memory. Note that @var{maxmem} must be aligned to the page size.
264 For example, the following command-line sets the guest startup RAM size to
265 1GB, creates 3 slots to hotplug additional memory and sets the maximum
266 memory the guest can reach to 4GB:
269 qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
272 If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
273 be enabled and the guest startup RAM will never increase.
276 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
277 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
279 @item -mem-path @var{path}
281 Allocate guest RAM from a temporarily created file in @var{path}.
284 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
285 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
289 @findex -mem-prealloc
290 Preallocate memory when using -mem-path.
293 DEF("k", HAS_ARG, QEMU_OPTION_k,
294 "-k language use keyboard layout (for example 'fr' for French)\n",
297 @item -k @var{language}
299 Use keyboard layout @var{language} (for example @code{fr} for
300 French). This option is only needed where it is not easy to get raw PC
301 keycodes (e.g. on Macs, with some X11 servers or with a VNC
302 display). You don't normally need to use it on PC/Linux or PC/Windows
305 The available layouts are:
307 ar de-ch es fo fr-ca hu ja mk no pt-br sv
308 da en-gb et fr fr-ch is lt nl pl ru th
309 de en-us fi fr-be hr it lv nl-be pt sl tr
312 The default is @code{en-us}.
316 DEF("audio-help", 0, QEMU_OPTION_audio_help,
317 "-audio-help print list of audio drivers and their options\n",
322 Will show the audio subsystem help: list of drivers, tunable
326 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
327 "-soundhw c1,... enable audio support\n"
328 " and only specified sound cards (comma separated list)\n"
329 " use '-soundhw help' to get the list of supported cards\n"
330 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
332 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
334 Enable audio and selected sound hardware. Use 'help' to print all
335 available sound hardware.
338 qemu-system-i386 -soundhw sb16,adlib disk.img
339 qemu-system-i386 -soundhw es1370 disk.img
340 qemu-system-i386 -soundhw ac97 disk.img
341 qemu-system-i386 -soundhw hda disk.img
342 qemu-system-i386 -soundhw all disk.img
343 qemu-system-i386 -soundhw help
346 Note that Linux's i810_audio OSS kernel (for AC97) module might
347 require manually specifying clocking.
350 modprobe i810_audio clocking=48000
354 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
355 "-balloon none disable balloon device\n"
356 "-balloon virtio[,addr=str]\n"
357 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
361 Disable balloon device.
362 @item -balloon virtio[,addr=@var{addr}]
363 Enable virtio balloon device (default), optionally with PCI address
367 DEF("device", HAS_ARG, QEMU_OPTION_device,
368 "-device driver[,prop[=value][,...]]\n"
369 " add device (based on driver)\n"
370 " prop=value,... sets driver properties\n"
371 " use '-device help' to print all possible drivers\n"
372 " use '-device driver,help' to print all possible properties\n",
375 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
377 Add device @var{driver}. @var{prop}=@var{value} sets driver
378 properties. Valid properties depend on the driver. To get help on
379 possible drivers and properties, use @code{-device help} and
380 @code{-device @var{driver},help}.
383 DEF("name", HAS_ARG, QEMU_OPTION_name,
384 "-name string1[,process=string2][,debug-threads=on|off]\n"
385 " set the name of the guest\n"
386 " string1 sets the window title and string2 the process name (on Linux)\n"
387 " When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
388 " NOTE: The thread names are for debugging and not a stable API.\n",
391 @item -name @var{name}
393 Sets the @var{name} of the guest.
394 This name will be displayed in the SDL window caption.
395 The @var{name} will also be used for the VNC server.
396 Also optionally set the top visible process name in Linux.
397 Naming of individual threads can also be enabled on Linux to aid debugging.
400 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
401 "-uuid %08x-%04x-%04x-%04x-%012x\n"
402 " specify machine UUID\n", QEMU_ARCH_ALL)
404 @item -uuid @var{uuid}
414 DEFHEADING(Block device options:)
419 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
420 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
421 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
423 @item -fda @var{file}
424 @itemx -fdb @var{file}
427 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}).
430 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
431 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
432 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
433 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
434 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
435 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
437 @item -hda @var{file}
438 @itemx -hdb @var{file}
439 @itemx -hdc @var{file}
440 @itemx -hdd @var{file}
445 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
448 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
449 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
452 @item -cdrom @var{file}
454 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
455 @option{-cdrom} at the same time). You can use the host CD-ROM by
456 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
459 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
460 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
461 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
462 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
463 " [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
464 " [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
465 " [,readonly=on|off][,copy-on-read=on|off]\n"
466 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
467 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
468 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
469 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
470 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
471 " [[,iops_size=is]]\n"
473 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
475 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
478 Define a new drive. Valid options are:
481 @item file=@var{file}
482 This option defines which disk image (@pxref{disk_images}) to use with
483 this drive. If the filename contains comma, you must double it
484 (for instance, "file=my,,file" to use file "my,file").
486 Special files such as iSCSI devices can be specified using protocol
487 specific URLs. See the section for "Device URL Syntax" for more information.
488 @item if=@var{interface}
489 This option defines on which type on interface the drive is connected.
490 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio.
491 @item bus=@var{bus},unit=@var{unit}
492 These options define where is connected the drive by defining the bus number and
494 @item index=@var{index}
495 This option defines where is connected the drive by using an index in the list
496 of available connectors of a given interface type.
497 @item media=@var{media}
498 This option defines the type of the media: disk or cdrom.
499 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
500 These options have the same definition as they have in @option{-hdachs}.
501 @item snapshot=@var{snapshot}
502 @var{snapshot} is "on" or "off" and controls snapshot mode for the given drive
503 (see @option{-snapshot}).
504 @item cache=@var{cache}
505 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
507 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
508 @item discard=@var{discard}
509 @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.
510 @item format=@var{format}
511 Specify which disk @var{format} will be used rather than detecting
512 the format. Can be used to specifiy format=raw to avoid interpreting
513 an untrusted format header.
514 @item serial=@var{serial}
515 This option specifies the serial number to assign to the device.
516 @item addr=@var{addr}
517 Specify the controller's PCI address (if=virtio only).
518 @item werror=@var{action},rerror=@var{action}
519 Specify which @var{action} to take on write and read errors. Valid actions are:
520 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
521 "report" (report the error to the guest), "enospc" (pause QEMU only if the
522 host disk is full; report the error to the guest otherwise).
523 The default setting is @option{werror=enospc} and @option{rerror=report}.
525 Open drive @option{file} as read-only. Guest write attempts will fail.
526 @item copy-on-read=@var{copy-on-read}
527 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
528 file sectors into the image file.
529 @item detect-zeroes=@var{detect-zeroes}
530 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
531 conversion of plain zero writes by the OS to driver specific optimized
532 zero write commands. You may even choose "unmap" if @var{discard} is set
533 to "unmap" to allow a zero write to be converted to an UNMAP operation.
536 By default, the @option{cache=writeback} mode is used. It will report data
537 writes as completed as soon as the data is present in the host page cache.
538 This is safe as long as your guest OS makes sure to correctly flush disk caches
539 where needed. If your guest OS does not handle volatile disk write caches
540 correctly and your host crashes or loses power, then the guest may experience
543 For such guests, you should consider using @option{cache=writethrough}. This
544 means that the host page cache will be used to read and write data, but write
545 notification will be sent to the guest only after QEMU has made sure to flush
546 each write to the disk. Be aware that this has a major impact on performance.
548 The host page cache can be avoided entirely with @option{cache=none}. This will
549 attempt to do disk IO directly to the guest's memory. QEMU may still perform
550 an internal copy of the data. Note that this is considered a writeback mode and
551 the guest OS must handle the disk write cache correctly in order to avoid data
552 corruption on host crashes.
554 The host page cache can be avoided while only sending write notifications to
555 the guest when the data has been flushed to the disk using
556 @option{cache=directsync}.
558 In case you don't care about data integrity over host failures, use
559 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
560 data to the disk but can instead keep things in cache. If anything goes wrong,
561 like your host losing power, the disk storage getting disconnected accidentally,
562 etc. your image will most probably be rendered unusable. When using
563 the @option{-snapshot} option, unsafe caching is always used.
565 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
566 useful when the backing file is over a slow network. By default copy-on-read
569 Instead of @option{-cdrom} you can use:
571 qemu-system-i386 -drive file=file,index=2,media=cdrom
574 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
577 qemu-system-i386 -drive file=file,index=0,media=disk
578 qemu-system-i386 -drive file=file,index=1,media=disk
579 qemu-system-i386 -drive file=file,index=2,media=disk
580 qemu-system-i386 -drive file=file,index=3,media=disk
583 You can open an image using pre-opened file descriptors from an fd set:
586 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
587 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
588 -drive file=/dev/fdset/2,index=0,media=disk
591 You can connect a CDROM to the slave of ide0:
593 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
596 If you don't specify the "file=" argument, you define an empty drive:
598 qemu-system-i386 -drive if=ide,index=1,media=cdrom
601 You can connect a SCSI disk with unit ID 6 on the bus #0:
603 qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6
606 Instead of @option{-fda}, @option{-fdb}, you can use:
608 qemu-system-i386 -drive file=file,index=0,if=floppy
609 qemu-system-i386 -drive file=file,index=1,if=floppy
612 By default, @var{interface} is "ide" and @var{index} is automatically
615 qemu-system-i386 -drive file=a -drive file=b"
619 qemu-system-i386 -hda a -hdb b
623 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
624 "-mtdblock file use 'file' as on-board Flash memory image\n",
627 @item -mtdblock @var{file}
629 Use @var{file} as on-board Flash memory image.
632 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
633 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
637 Use @var{file} as SecureDigital card image.
640 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
641 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
643 @item -pflash @var{file}
645 Use @var{file} as a parallel flash image.
648 DEF("snapshot", 0, QEMU_OPTION_snapshot,
649 "-snapshot write to temporary files instead of disk image files\n",
654 Write to temporary files instead of disk image files. In this case,
655 the raw disk image you use is not written back. You can however force
656 the write back by pressing @key{C-a s} (@pxref{disk_images}).
659 DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
660 "-hdachs c,h,s[,t]\n" \
661 " force hard disk 0 physical geometry and the optional BIOS\n" \
662 " translation (t=none or lba) (usually QEMU can guess them)\n",
665 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
667 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
668 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
669 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
670 all those parameters. This option is useful for old MS-DOS disk
674 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
675 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
676 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
681 @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}]
683 Define a new file system device. Valid options are:
686 This option specifies the fs driver backend to use.
687 Currently "local", "handle" and "proxy" file system drivers are supported.
689 Specifies identifier for this device
690 @item path=@var{path}
691 Specifies the export path for the file system device. Files under
692 this path will be available to the 9p client on the guest.
693 @item security_model=@var{security_model}
694 Specifies the security model to be used for this export path.
695 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
696 In "passthrough" security model, files are stored using the same
697 credentials as they are created on the guest. This requires QEMU
698 to run as root. In "mapped-xattr" security model, some of the file
699 attributes like uid, gid, mode bits and link target are stored as
700 file attributes. For "mapped-file" these attributes are stored in the
701 hidden .virtfs_metadata directory. Directories exported by this security model cannot
702 interact with other unix tools. "none" security model is same as
703 passthrough except the sever won't report failures if it fails to
704 set file attributes like ownership. Security model is mandatory
705 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
706 security model as a parameter.
707 @item writeout=@var{writeout}
708 This is an optional argument. The only supported value is "immediate".
709 This means that host page cache will be used to read and write data but
710 write notification will be sent to the guest only when the data has been
711 reported as written by the storage subsystem.
713 Enables exporting 9p share as a readonly mount for guests. By default
714 read-write access is given.
715 @item socket=@var{socket}
716 Enables proxy filesystem driver to use passed socket file for communicating
717 with virtfs-proxy-helper
718 @item sock_fd=@var{sock_fd}
719 Enables proxy filesystem driver to use passed socket descriptor for
720 communicating with virtfs-proxy-helper. Usually a helper like libvirt
721 will create socketpair and pass one of the fds as sock_fd
724 -fsdev option is used along with -device driver "virtio-9p-pci".
725 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
726 Options for virtio-9p-pci driver are:
729 Specifies the id value specified along with -fsdev option
730 @item mount_tag=@var{mount_tag}
731 Specifies the tag name to be used by the guest to mount this export point
736 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
737 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
738 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
743 @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}]
746 The general form of a Virtual File system pass-through options are:
749 This option specifies the fs driver backend to use.
750 Currently "local", "handle" and "proxy" file system drivers are supported.
752 Specifies identifier for this device
753 @item path=@var{path}
754 Specifies the export path for the file system device. Files under
755 this path will be available to the 9p client on the guest.
756 @item security_model=@var{security_model}
757 Specifies the security model to be used for this export path.
758 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
759 In "passthrough" security model, files are stored using the same
760 credentials as they are created on the guest. This requires QEMU
761 to run as root. In "mapped-xattr" security model, some of the file
762 attributes like uid, gid, mode bits and link target are stored as
763 file attributes. For "mapped-file" these attributes are stored in the
764 hidden .virtfs_metadata directory. Directories exported by this security model cannot
765 interact with other unix tools. "none" security model is same as
766 passthrough except the sever won't report failures if it fails to
767 set file attributes like ownership. Security model is mandatory only
768 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
769 model as a parameter.
770 @item writeout=@var{writeout}
771 This is an optional argument. The only supported value is "immediate".
772 This means that host page cache will be used to read and write data but
773 write notification will be sent to the guest only when the data has been
774 reported as written by the storage subsystem.
776 Enables exporting 9p share as a readonly mount for guests. By default
777 read-write access is given.
778 @item socket=@var{socket}
779 Enables proxy filesystem driver to use passed socket file for
780 communicating with virtfs-proxy-helper. Usually a helper like libvirt
781 will create socketpair and pass one of the fds as sock_fd
783 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
784 descriptor for interfacing with virtfs-proxy-helper
788 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
789 "-virtfs_synth Create synthetic file system image\n",
793 @findex -virtfs_synth
794 Create synthetic file system image
802 DEFHEADING(USB options:)
807 DEF("usb", 0, QEMU_OPTION_usb,
808 "-usb enable the USB driver (will be the default soon)\n",
813 Enable the USB driver (will be the default soon)
816 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
817 "-usbdevice name add the host or guest USB device 'name'\n",
821 @item -usbdevice @var{devname}
823 Add the USB device @var{devname}. @xref{usb_devices}.
828 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
831 Pointer device that uses absolute coordinates (like a touchscreen). This
832 means QEMU is able to report the mouse position without having to grab the
833 mouse. Also overrides the PS/2 mouse emulation when activated.
835 @item disk:[format=@var{format}]:@var{file}
836 Mass storage device based on file. The optional @var{format} argument
837 will be used rather than detecting the format. Can be used to specifiy
838 @code{format=raw} to avoid interpreting an untrusted format header.
840 @item host:@var{bus}.@var{addr}
841 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
843 @item host:@var{vendor_id}:@var{product_id}
844 Pass through the host device identified by @var{vendor_id}:@var{product_id}
847 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
848 Serial converter to host character device @var{dev}, see @code{-serial} for the
852 Braille device. This will use BrlAPI to display the braille output on a real
855 @item net:@var{options}
856 Network adapter that supports CDC ethernet and RNDIS protocols.
866 DEFHEADING(Display options:)
871 DEF("display", HAS_ARG, QEMU_OPTION_display,
872 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
873 " [,window_close=on|off]|curses|none|\n"
874 " gtk[,grab_on_hover=on|off]|\n"
875 " vnc=<display>[,<optargs>]\n"
876 " select display type\n", QEMU_ARCH_ALL)
878 @item -display @var{type}
880 Select type of display to use. This option is a replacement for the
881 old style -sdl/-curses/... options. Valid values for @var{type} are
884 Display video output via SDL (usually in a separate graphics
885 window; see the SDL documentation for other possibilities).
887 Display video output via curses. For graphics device models which
888 support a text mode, QEMU can display this output using a
889 curses/ncurses interface. Nothing is displayed when the graphics
890 device is in graphical mode or if the graphics device does not support
891 a text mode. Generally only the VGA device models support text mode.
893 Do not display video output. The guest will still see an emulated
894 graphics card, but its output will not be displayed to the QEMU
895 user. This option differs from the -nographic option in that it
896 only affects what is done with video output; -nographic also changes
897 the destination of the serial and parallel port data.
899 Display video output in a GTK window. This interface provides drop-down
900 menus and other UI elements to configure and control the VM during
903 Start a VNC server on display <arg>
907 DEF("nographic", 0, QEMU_OPTION_nographic,
908 "-nographic disable graphical output and redirect serial I/Os to console\n",
913 Normally, QEMU uses SDL to display the VGA output. With this option,
914 you can totally disable graphical output so that QEMU is a simple
915 command line application. The emulated serial port is redirected on
916 the console and muxed with the monitor (unless redirected elsewhere
917 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
918 with a serial console. Use @key{C-a h} for help on switching between
919 the console and monitor.
922 DEF("curses", 0, QEMU_OPTION_curses,
923 "-curses use a curses/ncurses interface instead of SDL\n",
928 Normally, QEMU uses SDL to display the VGA output. With this option,
929 QEMU can display the VGA output when in text mode using a
930 curses/ncurses interface. Nothing is displayed in graphical mode.
933 DEF("no-frame", 0, QEMU_OPTION_no_frame,
934 "-no-frame open SDL window without a frame and window decorations\n",
939 Do not use decorations for SDL windows and start them using the whole
940 available screen space. This makes the using QEMU in a dedicated desktop
941 workspace more convenient.
944 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
945 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
950 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
951 affects the special keys (for fullscreen, monitor-mode switching, etc).
954 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
955 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
960 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
961 affects the special keys (for fullscreen, monitor-mode switching, etc).
964 DEF("no-quit", 0, QEMU_OPTION_no_quit,
965 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
969 Disable SDL window close capability.
972 DEF("sdl", 0, QEMU_OPTION_sdl,
973 "-sdl enable SDL\n", QEMU_ARCH_ALL)
980 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
981 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
982 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
983 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
984 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6|unix]\n"
985 " [,tls-ciphers=<list>]\n"
986 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
987 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
988 " [,sasl][,password=<secret>][,disable-ticketing]\n"
989 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
990 " [,jpeg-wan-compression=[auto|never|always]]\n"
991 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
992 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
993 " [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
994 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
996 " at least one of {port, tls-port} is mandatory\n",
999 @item -spice @var{option}[,@var{option}[,...]]
1001 Enable the spice remote desktop protocol. Valid options are
1006 Set the TCP port spice is listening on for plaintext channels.
1009 Set the IP address spice is listening on. Default is any address.
1014 Force using the specified IP version.
1016 @item password=<secret>
1017 Set the password you need to authenticate.
1020 Require that the client use SASL to authenticate with the spice.
1021 The exact choice of authentication method used is controlled from the
1022 system / user's SASL configuration file for the 'qemu' service. This
1023 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1024 unprivileged user, an environment variable SASL_CONF_PATH can be used
1025 to make it search alternate locations for the service config.
1026 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1027 it is recommended that SASL always be combined with the 'tls' and
1028 'x509' settings to enable use of SSL and server certificates. This
1029 ensures a data encryption preventing compromise of authentication
1032 @item disable-ticketing
1033 Allow client connects without authentication.
1035 @item disable-copy-paste
1036 Disable copy paste between the client and the guest.
1038 @item disable-agent-file-xfer
1039 Disable spice-vdagent based file-xfer between the client and the guest.
1042 Set the TCP port spice is listening on for encrypted channels.
1044 @item x509-dir=<dir>
1045 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1047 @item x509-key-file=<file>
1048 @itemx x509-key-password=<file>
1049 @itemx x509-cert-file=<file>
1050 @itemx x509-cacert-file=<file>
1051 @itemx x509-dh-key-file=<file>
1052 The x509 file names can also be configured individually.
1054 @item tls-ciphers=<list>
1055 Specify which ciphers to use.
1057 @item tls-channel=[main|display|cursor|inputs|record|playback]
1058 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1059 Force specific channel to be used with or without TLS encryption. The
1060 options can be specified multiple times to configure multiple
1061 channels. The special name "default" can be used to set the default
1062 mode. For channels which are not explicitly forced into one mode the
1063 spice client is allowed to pick tls/plaintext as he pleases.
1065 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1066 Configure image compression (lossless).
1067 Default is auto_glz.
1069 @item jpeg-wan-compression=[auto|never|always]
1070 @itemx zlib-glz-wan-compression=[auto|never|always]
1071 Configure wan image compression (lossy for slow links).
1074 @item streaming-video=[off|all|filter]
1075 Configure video stream detection. Default is filter.
1077 @item agent-mouse=[on|off]
1078 Enable/disable passing mouse events via vdagent. Default is on.
1080 @item playback-compression=[on|off]
1081 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1083 @item seamless-migration=[on|off]
1084 Enable/disable spice seamless migration. Default is off.
1089 DEF("portrait", 0, QEMU_OPTION_portrait,
1090 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1095 Rotate graphical output 90 deg left (only PXA LCD).
1098 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1099 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1102 @item -rotate @var{deg}
1104 Rotate graphical output some deg left (only PXA LCD).
1107 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1108 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
1109 " select video card type\n", QEMU_ARCH_ALL)
1111 @item -vga @var{type}
1113 Select type of VGA card to emulate. Valid values for @var{type} are
1116 Cirrus Logic GD5446 Video card. All Windows versions starting from
1117 Windows 95 should recognize and use this graphic card. For optimal
1118 performances, use 16 bit color depth in the guest and the host OS.
1119 (This one is the default)
1121 Standard VGA card with Bochs VBE extensions. If your guest OS
1122 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1123 to use high resolution modes (>= 1280x1024x16) then you should use
1126 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1127 recent XFree86/XOrg server or Windows guest with a driver for this
1130 QXL paravirtual graphic card. It is VGA compatible (including VESA
1131 2.0 VBE support). Works best with qxl guest drivers installed though.
1132 Recommended choice when using the spice protocol.
1134 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1135 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1136 fixed resolution of 1024x768.
1138 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1139 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1140 resolutions aimed at people wishing to run older Solaris versions.
1148 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1149 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1152 @findex -full-screen
1153 Start in full screen.
1156 DEF("g", 1, QEMU_OPTION_g ,
1157 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1158 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1160 @item -g @var{width}x@var{height}[x@var{depth}]
1162 Set the initial graphical resolution and depth (PPC, SPARC only).
1165 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1166 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL)
1168 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1170 Normally, QEMU uses SDL to display the VGA output. With this option,
1171 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1172 display over the VNC session. It is very useful to enable the usb
1173 tablet device when using this option (option @option{-usbdevice
1174 tablet}). When using the VNC display, you must use the @option{-k}
1175 parameter to set the keyboard layout if you are not using en-us. Valid
1176 syntax for the @var{display} is
1180 @item @var{host}:@var{d}
1182 TCP connections will only be allowed from @var{host} on display @var{d}.
1183 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1184 be omitted in which case the server will accept connections from any host.
1186 @item unix:@var{path}
1188 Connections will be allowed over UNIX domain sockets where @var{path} is the
1189 location of a unix socket to listen for connections on.
1193 VNC is initialized but not started. The monitor @code{change} command
1194 can be used to later start the VNC server.
1198 Following the @var{display} value there may be one or more @var{option} flags
1199 separated by commas. Valid options are
1205 Connect to a listening VNC client via a ``reverse'' connection. The
1206 client is specified by the @var{display}. For reverse network
1207 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1208 is a TCP port number, not a display number.
1212 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1213 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1214 specified connections will only be allowed from this host.
1215 As an alternative the Websocket port could be specified by using
1216 @code{websocket}=@var{port}.
1217 TLS encryption for the Websocket connection is supported if the required
1218 certificates are specified with the VNC option @option{x509}.
1222 Require that password based authentication is used for client connections.
1224 The password must be set separately using the @code{set_password} command in
1225 the @ref{pcsys_monitor}. The syntax to change your password is:
1226 @code{set_password <protocol> <password>} where <protocol> could be either
1229 If you would like to change <protocol> password expiration, you should use
1230 @code{expire_password <protocol> <expiration-time>} where expiration time could
1231 be one of the following options: now, never, +seconds or UNIX time of
1232 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1233 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1236 You can also use keywords "now" or "never" for the expiration time to
1237 allow <protocol> password to expire immediately or never expire.
1241 Require that client use TLS when communicating with the VNC server. This
1242 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1243 attack. It is recommended that this option be combined with either the
1244 @option{x509} or @option{x509verify} options.
1246 @item x509=@var{/path/to/certificate/dir}
1248 Valid if @option{tls} is specified. Require that x509 credentials are used
1249 for negotiating the TLS session. The server will send its x509 certificate
1250 to the client. It is recommended that a password be set on the VNC server
1251 to provide authentication of the client when this is used. The path following
1252 this option specifies where the x509 certificates are to be loaded from.
1253 See the @ref{vnc_security} section for details on generating certificates.
1255 @item x509verify=@var{/path/to/certificate/dir}
1257 Valid if @option{tls} is specified. Require that x509 credentials are used
1258 for negotiating the TLS session. The server will send its x509 certificate
1259 to the client, and request that the client send its own x509 certificate.
1260 The server will validate the client's certificate against the CA certificate,
1261 and reject clients when validation fails. If the certificate authority is
1262 trusted, this is a sufficient authentication mechanism. You may still wish
1263 to set a password on the VNC server as a second authentication layer. The
1264 path following this option specifies where the x509 certificates are to
1265 be loaded from. See the @ref{vnc_security} section for details on generating
1270 Require that the client use SASL to authenticate with the VNC server.
1271 The exact choice of authentication method used is controlled from the
1272 system / user's SASL configuration file for the 'qemu' service. This
1273 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1274 unprivileged user, an environment variable SASL_CONF_PATH can be used
1275 to make it search alternate locations for the service config.
1276 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1277 it is recommended that SASL always be combined with the 'tls' and
1278 'x509' settings to enable use of SSL and server certificates. This
1279 ensures a data encryption preventing compromise of authentication
1280 credentials. See the @ref{vnc_security} section for details on using
1281 SASL authentication.
1285 Turn on access control lists for checking of the x509 client certificate
1286 and SASL party. For x509 certs, the ACL check is made against the
1287 certificate's distinguished name. This is something that looks like
1288 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1289 made against the username, which depending on the SASL plugin, may
1290 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1291 When the @option{acl} flag is set, the initial access list will be
1292 empty, with a @code{deny} policy. Thus no one will be allowed to
1293 use the VNC server until the ACLs have been loaded. This can be
1294 achieved using the @code{acl} monitor command.
1298 Enable lossy compression methods (gradient, JPEG, ...). If this
1299 option is set, VNC client may receive lossy framebuffer updates
1300 depending on its encoding settings. Enabling this option can save
1301 a lot of bandwidth at the expense of quality.
1305 Disable adaptive encodings. Adaptive encodings are enabled by default.
1306 An adaptive encoding will try to detect frequently updated screen regions,
1307 and send updates in these regions using a lossy encoding (like JPEG).
1308 This can be really helpful to save bandwidth when playing videos. Disabling
1309 adaptive encodings restores the original static behavior of encodings
1312 @item share=[allow-exclusive|force-shared|ignore]
1314 Set display sharing policy. 'allow-exclusive' allows clients to ask
1315 for exclusive access. As suggested by the rfb spec this is
1316 implemented by dropping other connections. Connecting multiple
1317 clients in parallel requires all clients asking for a shared session
1318 (vncviewer: -shared switch). This is the default. 'force-shared'
1319 disables exclusive client access. Useful for shared desktop sessions,
1320 where you don't want someone forgetting specify -shared disconnect
1321 everybody else. 'ignore' completely ignores the shared flag and
1322 allows everybody connect unconditionally. Doesn't conform to the rfb
1323 spec but is traditional QEMU behavior.
1331 ARCHHEADING(, QEMU_ARCH_I386)
1333 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1338 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1339 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1344 Use it when installing Windows 2000 to avoid a disk full bug. After
1345 Windows 2000 is installed, you no longer need this option (this option
1346 slows down the IDE transfers).
1349 HXCOMM Deprecated by -rtc
1350 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1352 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1353 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1356 @item -no-fd-bootchk
1357 @findex -no-fd-bootchk
1358 Disable boot signature checking for floppy disks in BIOS. May
1359 be needed to boot from old floppy disks.
1362 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1363 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1367 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1368 it if your guest OS complains about ACPI problems (PC target machine
1372 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1373 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1377 Disable HPET support.
1380 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1381 "-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"
1382 " ACPI table description\n", QEMU_ARCH_I386)
1384 @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}]...]
1386 Add ACPI table with specified header fields and context from specified files.
1387 For file=, take whole ACPI table from the specified files, including all
1388 ACPI headers (possible overridden by other options).
1389 For data=, only data
1390 portion of the table is used, all header information is specified in the
1394 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1395 "-smbios file=binary\n"
1396 " load SMBIOS entry from binary file\n"
1397 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1399 " specify SMBIOS type 0 fields\n"
1400 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1401 " [,uuid=uuid][,sku=str][,family=str]\n"
1402 " specify SMBIOS type 1 fields\n"
1403 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1404 " [,asset=str][,location=str]\n"
1405 " specify SMBIOS type 2 fields\n"
1406 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
1408 " specify SMBIOS type 3 fields\n"
1409 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
1410 " [,asset=str][,part=str]\n"
1411 " specify SMBIOS type 4 fields\n"
1412 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
1413 " [,asset=str][,part=str][,speed=%d]\n"
1414 " specify SMBIOS type 17 fields\n",
1417 @item -smbios file=@var{binary}
1419 Load SMBIOS entry from binary file.
1421 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1422 Specify SMBIOS type 0 fields
1424 @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}]
1425 Specify SMBIOS type 1 fields
1427 @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}]
1428 Specify SMBIOS type 2 fields
1430 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1431 Specify SMBIOS type 3 fields
1433 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1434 Specify SMBIOS type 4 fields
1436 @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}]
1437 Specify SMBIOS type 17 fields
1445 DEFHEADING(Network options:)
1450 HXCOMM Legacy slirp options (now moved to -net user):
1452 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1453 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1454 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1456 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1460 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1462 "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1463 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n"
1464 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1466 "[,smb=dir[,smbserver=addr]]\n"
1468 " configure a user mode network backend with ID 'str',\n"
1469 " its DHCP server and optional services\n"
1472 "-netdev tap,id=str,ifname=name\n"
1473 " configure a host TAP network backend with ID 'str'\n"
1475 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
1476 " [,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
1477 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
1478 " configure a host TAP network backend with ID 'str'\n"
1479 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1480 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1481 " to deconfigure it\n"
1482 " use '[down]script=no' to disable script execution\n"
1483 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1485 " use 'fd=h' to connect to an already opened TAP interface\n"
1486 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
1487 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1488 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1489 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1490 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1491 " use vhost=on to enable experimental in kernel accelerator\n"
1492 " (only has effect for virtio guests which use MSIX)\n"
1493 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1494 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1495 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
1496 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
1497 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
1498 " configure a host TAP network backend with ID 'str' that is\n"
1499 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
1500 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
1503 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
1504 " [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
1505 " [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
1506 " [,rxcookie=rxcookie][,offset=offset]\n"
1507 " configure a network backend with ID 'str' connected to\n"
1508 " an Ethernet over L2TPv3 pseudowire.\n"
1509 " Linux kernel 3.3+ as well as most routers can talk\n"
1510 " L2TPv3. This transport allows connecting a VM to a VM,\n"
1511 " VM to a router and even VM to Host. It is a nearly-universal\n"
1512 " standard (RFC3391). Note - this implementation uses static\n"
1513 " pre-configured tunnels (same as the Linux kernel).\n"
1514 " use 'src=' to specify source address\n"
1515 " use 'dst=' to specify destination address\n"
1516 " use 'udp=on' to specify udp encapsulation\n"
1517 " use 'srcport=' to specify source udp port\n"
1518 " use 'dstport=' to specify destination udp port\n"
1519 " use 'ipv6=on' to force v6\n"
1520 " L2TPv3 uses cookies to prevent misconfiguration as\n"
1521 " well as a weak security measure\n"
1522 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
1523 " use 'txcookie=0x012345678' to specify a txcookie\n"
1524 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
1525 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
1526 " use 'pincounter=on' to work around broken counter handling in peer\n"
1527 " use 'offset=X' to add an extra offset between header and data\n"
1529 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
1530 " configure a network backend to connect to another network\n"
1531 " using a socket connection\n"
1532 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1533 " configure a network backend to connect to a multicast maddr and port\n"
1534 " use 'localaddr=addr' to specify the host address to send packets from\n"
1535 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
1536 " configure a network backend to connect to another network\n"
1537 " using an UDP tunnel\n"
1539 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1540 " configure a network backend to connect to port 'n' of a vde switch\n"
1541 " running on host and listening for incoming connections on 'socketpath'.\n"
1542 " Use group 'groupname' and mode 'octalmode' to change default\n"
1543 " ownership and permissions for communication port.\n"
1545 #ifdef CONFIG_NETMAP
1546 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
1547 " attach to the existing netmap-enabled network interface 'name', or to a\n"
1548 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
1549 " netmap device, defaults to '/dev/netmap')\n"
1551 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
1552 " configure a vhost-user network, backed by a chardev 'dev'\n"
1553 "-netdev hubport,id=str,hubid=n\n"
1554 " configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
1555 DEF("net", HAS_ARG, QEMU_OPTION_net,
1556 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1557 " old way to create a new NIC and connect it to VLAN 'n'\n"
1558 " (use the '-device devtype,netdev=str' option if possible instead)\n"
1559 "-net dump[,vlan=n][,file=f][,len=n]\n"
1560 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
1561 "-net none use it alone to have zero network devices. If no -net option\n"
1562 " is provided, the default is '-net nic -net user'\n"
1572 #ifdef CONFIG_NETMAP
1575 "socket][,vlan=n][,option][,option][,...]\n"
1576 " old way to initialize a host network interface\n"
1577 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
1579 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1581 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1582 = 0 is the default). The NIC is an e1000 by default on the PC
1583 target. Optionally, the MAC address can be changed to @var{mac}, the
1584 device address set to @var{addr} (PCI cards only),
1585 and a @var{name} can be assigned for use in monitor commands.
1586 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1587 that the card should have; this option currently only affects virtio cards; set
1588 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1589 NIC is created. QEMU can emulate several different models of network card.
1590 Valid values for @var{type} are
1591 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1592 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1593 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1594 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1595 for a list of available devices for your target.
1597 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1599 @item -net user[,@var{option}][,@var{option}][,...]
1600 Use the user mode network stack which requires no administrator
1601 privilege to run. Valid options are:
1605 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1608 @itemx name=@var{name}
1609 Assign symbolic name for use in monitor commands.
1611 @item net=@var{addr}[/@var{mask}]
1612 Set IP network address the guest will see. Optionally specify the netmask,
1613 either in the form a.b.c.d or as number of valid top-most bits. Default is
1616 @item host=@var{addr}
1617 Specify the guest-visible address of the host. Default is the 2nd IP in the
1618 guest network, i.e. x.x.x.2.
1620 @item restrict=on|off
1621 If this option is enabled, the guest will be isolated, i.e. it will not be
1622 able to contact the host and no guest IP packets will be routed over the host
1623 to the outside. This option does not affect any explicitly set forwarding rules.
1625 @item hostname=@var{name}
1626 Specifies the client hostname reported by the built-in DHCP server.
1628 @item dhcpstart=@var{addr}
1629 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1630 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1632 @item dns=@var{addr}
1633 Specify the guest-visible address of the virtual nameserver. The address must
1634 be different from the host address. Default is the 3rd IP in the guest network,
1637 @item dnssearch=@var{domain}
1638 Provides an entry for the domain-search list sent by the built-in
1639 DHCP server. More than one domain suffix can be transmitted by specifying
1640 this option multiple times. If supported, this will cause the guest to
1641 automatically try to append the given domain suffix(es) in case a domain name
1642 can not be resolved.
1646 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1649 @item tftp=@var{dir}
1650 When using the user mode network stack, activate a built-in TFTP
1651 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1652 The TFTP client on the guest must be configured in binary mode (use the command
1653 @code{bin} of the Unix TFTP client).
1655 @item bootfile=@var{file}
1656 When using the user mode network stack, broadcast @var{file} as the BOOTP
1657 filename. In conjunction with @option{tftp}, this can be used to network boot
1658 a guest from a local directory.
1660 Example (using pxelinux):
1662 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1665 @item smb=@var{dir}[,smbserver=@var{addr}]
1666 When using the user mode network stack, activate a built-in SMB
1667 server so that Windows OSes can access to the host files in @file{@var{dir}}
1668 transparently. The IP address of the SMB server can be set to @var{addr}. By
1669 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1671 In the guest Windows OS, the line:
1675 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1676 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1678 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1680 Note that a SAMBA server must be installed on the host OS.
1681 QEMU was tested successfully with smbd versions from Red Hat 9,
1682 Fedora Core 3 and OpenSUSE 11.x.
1684 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1685 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1686 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1687 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1688 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1689 be bound to a specific host interface. If no connection type is set, TCP is
1690 used. This option can be given multiple times.
1692 For example, to redirect host X11 connection from screen 1 to guest
1693 screen 0, use the following:
1697 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1698 # this host xterm should open in the guest X11 server
1702 To redirect telnet connections from host port 5555 to telnet port on
1703 the guest, use the following:
1707 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1708 telnet localhost 5555
1711 Then when you use on the host @code{telnet localhost 5555}, you
1712 connect to the guest telnet server.
1714 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1715 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1716 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1717 to the character device @var{dev} or to a program executed by @var{cmd:command}
1718 which gets spawned for each connection. This option can be given multiple times.
1720 You can either use a chardev directly and have that one used throughout QEMU's
1721 lifetime, like in the following example:
1724 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1725 # the guest accesses it
1726 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1729 Or you can execute a command on every TCP connection established by the guest,
1730 so that QEMU behaves similar to an inetd process for that virtual server:
1733 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
1734 # and connect the TCP stream to its stdin/stdout
1735 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1740 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1741 processed and applied to -net user. Mixing them with the new configuration
1742 syntax gives undefined results. Their use for new applications is discouraged
1743 as they will be removed from future versions.
1745 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1746 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1747 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1749 Use the network script @var{file} to configure it and the network script
1750 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1751 automatically provides one. The default network configure script is
1752 @file{/etc/qemu-ifup} and the default network deconfigure script is
1753 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1754 to disable script execution.
1756 If running QEMU as an unprivileged user, use the network helper
1757 @var{helper} to configure the TAP interface. The default network
1758 helper executable is @file{/path/to/qemu-bridge-helper}.
1760 @option{fd}=@var{h} can be used to specify the handle of an already
1761 opened host TAP interface.
1766 #launch a QEMU instance with the default network script
1767 qemu-system-i386 linux.img -net nic -net tap
1771 #launch a QEMU instance with two NICs, each one connected
1773 qemu-system-i386 linux.img \
1774 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1775 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1779 #launch a QEMU instance with the default network helper to
1780 #connect a TAP device to bridge br0
1781 qemu-system-i386 linux.img \
1782 -net nic -net tap,"helper=/path/to/qemu-bridge-helper"
1785 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1786 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1787 Connect a host TAP network interface to a host bridge device.
1789 Use the network helper @var{helper} to configure the TAP interface and
1790 attach it to the bridge. The default network helper executable is
1791 @file{/path/to/qemu-bridge-helper} and the default bridge
1792 device is @file{br0}.
1797 #launch a QEMU instance with the default network helper to
1798 #connect a TAP device to bridge br0
1799 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1803 #launch a QEMU instance with the default network helper to
1804 #connect a TAP device to bridge qemubr0
1805 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1808 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1809 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1811 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1812 machine using a TCP socket connection. If @option{listen} is
1813 specified, QEMU waits for incoming connections on @var{port}
1814 (@var{host} is optional). @option{connect} is used to connect to
1815 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1816 specifies an already opened TCP socket.
1820 # launch a first QEMU instance
1821 qemu-system-i386 linux.img \
1822 -net nic,macaddr=52:54:00:12:34:56 \
1823 -net socket,listen=:1234
1824 # connect the VLAN 0 of this instance to the VLAN 0
1825 # of the first instance
1826 qemu-system-i386 linux.img \
1827 -net nic,macaddr=52:54:00:12:34:57 \
1828 -net socket,connect=127.0.0.1:1234
1831 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1832 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1834 Create a VLAN @var{n} shared with another QEMU virtual
1835 machines using a UDP multicast socket, effectively making a bus for
1836 every QEMU with same multicast address @var{maddr} and @var{port}.
1840 Several QEMU can be running on different hosts and share same bus (assuming
1841 correct multicast setup for these hosts).
1843 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1844 @url{http://user-mode-linux.sf.net}.
1846 Use @option{fd=h} to specify an already opened UDP multicast socket.
1851 # launch one QEMU instance
1852 qemu-system-i386 linux.img \
1853 -net nic,macaddr=52:54:00:12:34:56 \
1854 -net socket,mcast=230.0.0.1:1234
1855 # launch another QEMU instance on same "bus"
1856 qemu-system-i386 linux.img \
1857 -net nic,macaddr=52:54:00:12:34:57 \
1858 -net socket,mcast=230.0.0.1:1234
1859 # launch yet another QEMU instance on same "bus"
1860 qemu-system-i386 linux.img \
1861 -net nic,macaddr=52:54:00:12:34:58 \
1862 -net socket,mcast=230.0.0.1:1234
1865 Example (User Mode Linux compat.):
1867 # launch QEMU instance (note mcast address selected
1869 qemu-system-i386 linux.img \
1870 -net nic,macaddr=52:54:00:12:34:56 \
1871 -net socket,mcast=239.192.168.1:1102
1873 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1876 Example (send packets from host's 1.2.3.4):
1878 qemu-system-i386 linux.img \
1879 -net nic,macaddr=52:54:00:12:34:56 \
1880 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1883 @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}]
1884 @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}]
1885 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
1886 protocol to transport Ethernet (and other Layer 2) data frames between
1887 two systems. It is present in routers, firewalls and the Linux kernel
1888 (from version 3.3 onwards).
1890 This transport allows a VM to communicate to another VM, router or firewall directly.
1892 @item src=@var{srcaddr}
1893 source address (mandatory)
1894 @item dst=@var{dstaddr}
1895 destination address (mandatory)
1897 select udp encapsulation (default is ip).
1898 @item srcport=@var{srcport}
1900 @item dstport=@var{dstport}
1901 destination udp port.
1903 force v6, otherwise defaults to v4.
1904 @item rxcookie=@var{rxcookie}
1905 @itemx txcookie=@var{txcookie}
1906 Cookies are a weak form of security in the l2tpv3 specification.
1907 Their function is mostly to prevent misconfiguration. By default they are 32
1910 Set cookie size to 64 bit instead of the default 32
1912 Force a 'cut-down' L2TPv3 with no counter as in
1913 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
1915 Work around broken counter handling in peer. This may also help on
1916 networks which have packet reorder.
1917 @item offset=@var{offset}
1918 Add an extra offset between header and data
1920 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
1921 on the remote Linux host 1.2.3.4:
1923 # Setup tunnel on linux host using raw ip as encapsulation
1925 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
1926 encap udp udp_sport 16384 udp_dport 16384
1927 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
1928 0xFFFFFFFF peer_session_id 0xFFFFFFFF
1929 ifconfig vmtunnel0 mtu 1500
1930 ifconfig vmtunnel0 up
1931 brctl addif br-lan vmtunnel0
1935 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
1937 qemu-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
1942 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1943 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1944 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
1945 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
1946 and MODE @var{octalmode} to change default ownership and permissions for
1947 communication port. This option is only available if QEMU has been compiled
1948 with vde support enabled.
1953 vde_switch -F -sock /tmp/myswitch
1954 # launch QEMU instance
1955 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
1958 @item -netdev hubport,id=@var{id},hubid=@var{hubid}
1960 Create a hub port on QEMU "vlan" @var{hubid}.
1962 The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single
1963 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
1964 required hub automatically.
1966 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off]
1968 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
1969 be a unix domain socket backed one. The vhost-user uses a specifically defined
1970 protocol to pass vhost ioctl replacement messages to an application on the other
1971 end of the socket. On non-MSIX guests, the feature can be forced with
1976 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
1977 -numa node,memdev=mem \
1978 -chardev socket,path=/path/to/socket \
1979 -netdev type=vhost-user,id=net0,chardev=chr0 \
1980 -device virtio-net-pci,netdev=net0
1983 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
1984 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
1985 At most @var{len} bytes (64k by default) per packet are stored. The file format is
1986 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
1989 Indicate that no network devices should be configured. It is used to
1990 override the default configuration (@option{-net nic -net user}) which
1991 is activated if no @option{-net} options are provided.
1999 DEFHEADING(Character device options:)
2002 The general form of a character device option is:
2006 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
2007 "-chardev null,id=id[,mux=on|off]\n"
2008 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2009 " [,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (tcp)\n"
2010 "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,reconnect=seconds][,mux=on|off] (unix)\n"
2011 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
2012 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
2013 "-chardev msmouse,id=id[,mux=on|off]\n"
2014 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
2016 "-chardev ringbuf,id=id[,size=size]\n"
2017 "-chardev file,id=id,path=path[,mux=on|off]\n"
2018 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
2020 "-chardev console,id=id[,mux=on|off]\n"
2021 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2023 "-chardev pty,id=id[,mux=on|off]\n"
2024 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
2026 #ifdef CONFIG_BRLAPI
2027 "-chardev braille,id=id[,mux=on|off]\n"
2029 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2030 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2031 "-chardev serial,id=id,path=path[,mux=on|off]\n"
2032 "-chardev tty,id=id,path=path[,mux=on|off]\n"
2034 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2035 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
2036 "-chardev parport,id=id,path=path[,mux=on|off]\n"
2038 #if defined(CONFIG_SPICE)
2039 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
2040 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
2046 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2067 The specific backend will determine the applicable options.
2069 All devices must have an id, which can be any string up to 127 characters long.
2070 It is used to uniquely identify this device in other command line directives.
2072 A character device may be used in multiplexing mode by multiple front-ends.
2073 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
2074 between attached front-ends. Specify @option{mux=on} to enable this mode.
2076 Options to each backend are described below.
2078 @item -chardev null ,id=@var{id}
2079 A void device. This device will not emit any data, and will drop any data it
2080 receives. The null backend does not take any options.
2082 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}]
2084 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2085 unix socket will be created if @option{path} is specified. Behaviour is
2086 undefined if TCP options are specified for a unix socket.
2088 @option{server} specifies that the socket shall be a listening socket.
2090 @option{nowait} specifies that QEMU should not block waiting for a client to
2091 connect to a listening socket.
2093 @option{telnet} specifies that traffic on the socket should interpret telnet
2096 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2097 the remote end goes away. qemu will delay this many seconds and then attempt
2098 to reconnect. Zero disables reconnecting, and is the default.
2100 TCP and unix socket options are given below:
2104 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2106 @option{host} for a listening socket specifies the local address to be bound.
2107 For a connecting socket species the remote host to connect to. @option{host} is
2108 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2110 @option{port} for a listening socket specifies the local port to be bound. For a
2111 connecting socket specifies the port on the remote host to connect to.
2112 @option{port} can be given as either a port number or a service name.
2113 @option{port} is required.
2115 @option{to} is only relevant to listening sockets. If it is specified, and
2116 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2117 to and including @option{to} until it succeeds. @option{to} must be specified
2120 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2121 If neither is specified the socket may use either protocol.
2123 @option{nodelay} disables the Nagle algorithm.
2125 @item unix options: path=@var{path}
2127 @option{path} specifies the local path of the unix socket. @option{path} is
2132 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2134 Sends all traffic from the guest to a remote host over UDP.
2136 @option{host} specifies the remote host to connect to. If not specified it
2137 defaults to @code{localhost}.
2139 @option{port} specifies the port on the remote host to connect to. @option{port}
2142 @option{localaddr} specifies the local address to bind to. If not specified it
2143 defaults to @code{0.0.0.0}.
2145 @option{localport} specifies the local port to bind to. If not specified any
2146 available local port will be used.
2148 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2149 If neither is specified the device may use either protocol.
2151 @item -chardev msmouse ,id=@var{id}
2153 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2156 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2158 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2161 @option{width} and @option{height} specify the width and height respectively of
2162 the console, in pixels.
2164 @option{cols} and @option{rows} specify that the console be sized to fit a text
2165 console with the given dimensions.
2167 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2169 Create a ring buffer with fixed size @option{size}.
2170 @var{size} must be a power of two, and defaults to @code{64K}).
2172 @item -chardev file ,id=@var{id} ,path=@var{path}
2174 Log all traffic received from the guest to a file.
2176 @option{path} specifies the path of the file to be opened. This file will be
2177 created if it does not already exist, and overwritten if it does. @option{path}
2180 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2182 Create a two-way connection to the guest. The behaviour differs slightly between
2183 Windows hosts and other hosts:
2185 On Windows, a single duplex pipe will be created at
2186 @file{\\.pipe\@option{path}}.
2188 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2189 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2190 received by the guest. Data written by the guest can be read from
2191 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2194 @option{path} forms part of the pipe path as described above. @option{path} is
2197 @item -chardev console ,id=@var{id}
2199 Send traffic from the guest to QEMU's standard output. @option{console} does not
2202 @option{console} is only available on Windows hosts.
2204 @item -chardev serial ,id=@var{id} ,path=@option{path}
2206 Send traffic from the guest to a serial device on the host.
2208 On Unix hosts serial will actually accept any tty device,
2209 not only serial lines.
2211 @option{path} specifies the name of the serial device to open.
2213 @item -chardev pty ,id=@var{id}
2215 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2216 not take any options.
2218 @option{pty} is not available on Windows hosts.
2220 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2221 Connect to standard input and standard output of the QEMU process.
2223 @option{signal} controls if signals are enabled on the terminal, that includes
2224 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2225 default, use @option{signal=off} to disable it.
2227 @option{stdio} is not available on Windows hosts.
2229 @item -chardev braille ,id=@var{id}
2231 Connect to a local BrlAPI server. @option{braille} does not take any options.
2233 @item -chardev tty ,id=@var{id} ,path=@var{path}
2235 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2236 DragonFlyBSD hosts. It is an alias for @option{serial}.
2238 @option{path} specifies the path to the tty. @option{path} is required.
2240 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2241 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2243 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2245 Connect to a local parallel port.
2247 @option{path} specifies the path to the parallel port device. @option{path} is
2250 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2252 @option{spicevmc} is only available when spice support is built in.
2254 @option{debug} debug level for spicevmc
2256 @option{name} name of spice channel to connect to
2258 Connect to a spice virtual machine channel, such as vdiport.
2260 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2262 @option{spiceport} is only available when spice support is built in.
2264 @option{debug} debug level for spicevmc
2266 @option{name} name of spice port to connect to
2268 Connect to a spice port, allowing a Spice client to handle the traffic
2269 identified by a name (preferably a fqdn).
2277 DEFHEADING(Device URL Syntax:)
2280 In addition to using normal file images for the emulated storage devices,
2281 QEMU can also use networked resources such as iSCSI devices. These are
2282 specified using a special URL syntax.
2286 iSCSI support allows QEMU to access iSCSI resources directly and use as
2287 images for the guest storage. Both disk and cdrom images are supported.
2289 Syntax for specifying iSCSI LUNs is
2290 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2292 By default qemu will use the iSCSI initiator-name
2293 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2294 line or a configuration file.
2296 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2297 stalled requests and force a reestablishment of the session. The timeout
2298 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2299 1.15.0 or greater is required for this feature.
2301 Example (without authentication):
2303 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2304 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2305 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2308 Example (CHAP username/password via URL):
2310 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2313 Example (CHAP username/password via environment variables):
2315 LIBISCSI_CHAP_USERNAME="user" \
2316 LIBISCSI_CHAP_PASSWORD="password" \
2317 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2320 iSCSI support is an optional feature of QEMU and only available when
2321 compiled and linked against libiscsi.
2323 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
2324 "-iscsi [user=user][,password=password]\n"
2325 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2326 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
2327 " [,timeout=timeout]\n"
2328 " iSCSI session parameters\n", QEMU_ARCH_ALL)
2331 iSCSI parameters such as username and password can also be specified via
2332 a configuration file. See qemu-doc for more information and examples.
2335 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2336 as Unix Domain Sockets.
2338 Syntax for specifying a NBD device using TCP
2339 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2341 Syntax for specifying a NBD device using Unix Domain Sockets
2342 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2347 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2350 Example for Unix Domain Sockets
2352 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2356 QEMU supports SSH (Secure Shell) access to remote disks.
2360 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2361 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2364 Currently authentication must be done using ssh-agent. Other
2365 authentication methods may be supported in future.
2368 Sheepdog is a distributed storage system for QEMU.
2369 QEMU supports using either local sheepdog devices or remote networked
2372 Syntax for specifying a sheepdog device
2374 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2379 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2382 See also @url{http://http://www.osrg.net/sheepdog/}.
2385 GlusterFS is an user space distributed file system.
2386 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2387 TCP, Unix Domain Sockets and RDMA transport protocols.
2389 Syntax for specifying a VM disk image on GlusterFS volume is
2391 gluster[+transport]://[server[:port]]/volname/image[?socket=...]
2397 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img
2400 See also @url{http://www.gluster.org}.
2402 @item HTTP/HTTPS/FTP/FTPS/TFTP
2403 QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp.
2405 Syntax using a single filename:
2407 <protocol>://[<username>[:<password>]@@]<host>/<path>
2413 'http', 'https', 'ftp', 'ftps', or 'tftp'.
2416 Optional username for authentication to the remote server.
2419 Optional password for authentication to the remote server.
2422 Address of the remote server.
2425 Path on the remote server, including any query string.
2428 The following options are also supported:
2431 The full URL when passing options to the driver explicitly.
2434 The amount of data to read ahead with each range request to the remote server.
2435 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2436 does not have a suffix, it will be assumed to be in bytes. The value must be a
2437 multiple of 512 bytes. It defaults to 256k.
2440 Whether to verify the remote server's certificate when connecting over SSL. It
2441 can have the value 'on' or 'off'. It defaults to 'on'.
2444 Send this cookie (it can also be a list of cookies separated by ';') with
2445 each outgoing request. Only supported when using protocols such as HTTP
2446 which support cookies, otherwise ignored.
2449 Set the timeout in seconds of the CURL connection. This timeout is the time
2450 that CURL waits for a response from the remote server to get the size of the
2451 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2454 Note that when passing options to qemu explicitly, @option{driver} is the value
2457 Example: boot from a remote Fedora 20 live ISO image
2459 qemu-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
2461 qemu-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
2464 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2465 writes, copy-on-read, and a readahead of 64k
2467 qemu-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
2469 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
2472 Example: boot from an image stored on a VMware vSphere server with a self-signed
2473 certificate using a local overlay for writes, a readahead of 64k and a timeout
2476 qemu-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
2478 qemu-system-x86_64 -drive file=/tmp/test.qcow2
2486 DEFHEADING(Bluetooth(R) options:)
2491 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2492 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2493 "-bt hci,host[:id]\n" \
2494 " use host's HCI with the given name\n" \
2495 "-bt hci[,vlan=n]\n" \
2496 " emulate a standard HCI in virtual scatternet 'n'\n" \
2497 "-bt vhci[,vlan=n]\n" \
2498 " add host computer to virtual scatternet 'n' using VHCI\n" \
2499 "-bt device:dev[,vlan=n]\n" \
2500 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2505 Defines the function of the corresponding Bluetooth HCI. -bt options
2506 are matched with the HCIs present in the chosen machine type. For
2507 example when emulating a machine with only one HCI built into it, only
2508 the first @code{-bt hci[...]} option is valid and defines the HCI's
2509 logic. The Transport Layer is decided by the machine type. Currently
2510 the machines @code{n800} and @code{n810} have one HCI and all other
2514 The following three types are recognized:
2518 (default) The corresponding Bluetooth HCI assumes no internal logic
2519 and will not respond to any HCI commands or emit events.
2521 @item -bt hci,host[:@var{id}]
2522 (@code{bluez} only) The corresponding HCI passes commands / events
2523 to / from the physical HCI identified by the name @var{id} (default:
2524 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2525 capable systems like Linux.
2527 @item -bt hci[,vlan=@var{n}]
2528 Add a virtual, standard HCI that will participate in the Bluetooth
2529 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2530 VLANs, devices inside a bluetooth network @var{n} can only communicate
2531 with other devices in the same network (scatternet).
2534 @item -bt vhci[,vlan=@var{n}]
2535 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2536 to the host bluetooth stack instead of to the emulated target. This
2537 allows the host and target machines to participate in a common scatternet
2538 and communicate. Requires the Linux @code{vhci} driver installed. Can
2539 be used as following:
2542 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2545 @item -bt device:@var{dev}[,vlan=@var{n}]
2546 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2547 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2552 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2562 DEFHEADING(TPM device options:)
2564 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2565 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
2566 " use path to provide path to a character device; default is /dev/tpm0\n"
2567 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
2568 " not provided it will be searched for in /sys/class/misc/tpm?/device\n",
2572 The general form of a TPM device option is:
2575 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
2577 Backend type must be:
2578 @option{passthrough}.
2580 The specific backend type will determine the applicable options.
2581 The @code{-tpmdev} option creates the TPM backend and requires a
2582 @code{-device} option that specifies the TPM frontend interface model.
2584 Options to each backend are described below.
2586 Use 'help' to print all available TPM backend types.
2591 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
2593 (Linux-host only) Enable access to the host's TPM using the passthrough
2596 @option{path} specifies the path to the host's TPM device, i.e., on
2597 a Linux host this would be @code{/dev/tpm0}.
2598 @option{path} is optional and by default @code{/dev/tpm0} is used.
2600 @option{cancel-path} specifies the path to the host TPM device's sysfs
2601 entry allowing for cancellation of an ongoing TPM command.
2602 @option{cancel-path} is optional and by default QEMU will search for the
2605 Some notes about using the host's TPM with the passthrough driver:
2607 The TPM device accessed by the passthrough driver must not be
2608 used by any other application on the host.
2610 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2611 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2612 TPM again and may therefore not show a TPM-specific menu that would
2613 otherwise allow the user to configure the TPM, e.g., allow the user to
2614 enable/disable or activate/deactivate the TPM.
2615 Further, if TPM ownership is released from within a VM then the host's TPM
2616 will get disabled and deactivated. To enable and activate the
2617 TPM again afterwards, the host has to be rebooted and the user is
2618 required to enter the firmware's menu to enable and activate the TPM.
2619 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2621 To create a passthrough TPM use the following two options:
2623 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2625 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2626 @code{tpmdev=tpm0} in the device option.
2636 DEFHEADING(Linux/Multiboot boot specific:)
2639 When using these options, you can use a given Linux or Multiboot
2640 kernel without installing it in the disk image. It can be useful
2641 for easier testing of various kernels.
2646 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2647 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2649 @item -kernel @var{bzImage}
2651 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2652 or in multiboot format.
2655 DEF("append", HAS_ARG, QEMU_OPTION_append, \
2656 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2658 @item -append @var{cmdline}
2660 Use @var{cmdline} as kernel command line
2663 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
2664 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
2666 @item -initrd @var{file}
2668 Use @var{file} as initial ram disk.
2670 @item -initrd "@var{file1} arg=foo,@var{file2}"
2672 This syntax is only available with multiboot.
2674 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2678 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
2679 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
2681 @item -dtb @var{file}
2683 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2692 DEFHEADING(Debug/Expert options:)
2697 DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
2698 "-fw_cfg [name=]<name>,file=<file>\n"
2699 " add named fw_cfg entry from file\n",
2702 @item -fw_cfg [name=]@var{name},file=@var{file}
2704 Add named fw_cfg entry from file. @var{name} determines the name of
2705 the entry in the fw_cfg file directory exposed to the guest.
2708 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
2709 "-serial dev redirect the serial port to char device 'dev'\n",
2712 @item -serial @var{dev}
2714 Redirect the virtual serial port to host character device
2715 @var{dev}. The default device is @code{vc} in graphical mode and
2716 @code{stdio} in non graphical mode.
2718 This option can be used several times to simulate up to 4 serial
2721 Use @code{-serial none} to disable all serial ports.
2723 Available character devices are:
2725 @item vc[:@var{W}x@var{H}]
2726 Virtual console. Optionally, a width and height can be given in pixel with
2730 It is also possible to specify width or height in characters:
2735 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
2737 No device is allocated.
2740 @item chardev:@var{id}
2741 Use a named character device defined with the @code{-chardev} option.
2743 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2744 parameters are set according to the emulated ones.
2745 @item /dev/parport@var{N}
2746 [Linux only, parallel port only] Use host parallel port
2747 @var{N}. Currently SPP and EPP parallel port features can be used.
2748 @item file:@var{filename}
2749 Write output to @var{filename}. No character can be read.
2751 [Unix only] standard input/output
2752 @item pipe:@var{filename}
2753 name pipe @var{filename}
2755 [Windows only] Use host serial port @var{n}
2756 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
2757 This implements UDP Net Console.
2758 When @var{remote_host} or @var{src_ip} are not specified
2759 they default to @code{0.0.0.0}.
2760 When not using a specified @var{src_port} a random port is automatically chosen.
2762 If you just want a simple readonly console you can use @code{netcat} or
2763 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
2764 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
2765 will appear in the netconsole session.
2767 If you plan to send characters back via netconsole or you want to stop
2768 and start QEMU a lot of times, you should have QEMU use the same
2769 source port each time by using something like @code{-serial
2770 udp::4555@@:4556} to QEMU. Another approach is to use a patched
2771 version of netcat which can listen to a TCP port and send and receive
2772 characters via udp. If you have a patched version of netcat which
2773 activates telnet remote echo and single char transfer, then you can
2774 use the following options to step up a netcat redirector to allow
2775 telnet on port 5555 to access the QEMU port.
2778 -serial udp::4555@@:4556
2779 @item netcat options:
2780 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
2781 @item telnet options:
2785 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
2786 The TCP Net Console has two modes of operation. It can send the serial
2787 I/O to a location or wait for a connection from a location. By default
2788 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
2789 the @var{server} option QEMU will wait for a client socket application
2790 to connect to the port before continuing, unless the @code{nowait}
2791 option was specified. The @code{nodelay} option disables the Nagle buffering
2792 algorithm. The @code{reconnect} option only applies if @var{noserver} is
2793 set, if the connection goes down it will attempt to reconnect at the
2794 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
2795 one TCP connection at a time is accepted. You can use @code{telnet} to
2796 connect to the corresponding character device.
2798 @item Example to send tcp console to 192.168.0.2 port 4444
2799 -serial tcp:192.168.0.2:4444
2800 @item Example to listen and wait on port 4444 for connection
2801 -serial tcp::4444,server
2802 @item Example to not wait and listen on ip 192.168.0.100 port 4444
2803 -serial tcp:192.168.0.100:4444,server,nowait
2806 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
2807 The telnet protocol is used instead of raw tcp sockets. The options
2808 work the same as if you had specified @code{-serial tcp}. The
2809 difference is that the port acts like a telnet server or client using
2810 telnet option negotiation. This will also allow you to send the
2811 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
2812 sequence. Typically in unix telnet you do it with Control-] and then
2813 type "send break" followed by pressing the enter key.
2815 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
2816 A unix domain socket is used instead of a tcp socket. The option works the
2817 same as if you had specified @code{-serial tcp} except the unix domain socket
2818 @var{path} is used for connections.
2820 @item mon:@var{dev_string}
2821 This is a special option to allow the monitor to be multiplexed onto
2822 another serial port. The monitor is accessed with key sequence of
2823 @key{Control-a} and then pressing @key{c}.
2824 @var{dev_string} should be any one of the serial devices specified
2825 above. An example to multiplex the monitor onto a telnet server
2826 listening on port 4444 would be:
2828 @item -serial mon:telnet::4444,server,nowait
2830 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
2831 QEMU any more but will be passed to the guest instead.
2834 Braille device. This will use BrlAPI to display the braille output on a real
2838 Three button serial mouse. Configure the guest to use Microsoft protocol.
2842 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
2843 "-parallel dev redirect the parallel port to char device 'dev'\n",
2846 @item -parallel @var{dev}
2848 Redirect the virtual parallel port to host device @var{dev} (same
2849 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
2850 be used to use hardware devices connected on the corresponding host
2853 This option can be used several times to simulate up to 3 parallel
2856 Use @code{-parallel none} to disable all parallel ports.
2859 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
2860 "-monitor dev redirect the monitor to char device 'dev'\n",
2863 @item -monitor @var{dev}
2865 Redirect the monitor to host device @var{dev} (same devices as the
2867 The default device is @code{vc} in graphical mode and @code{stdio} in
2869 Use @code{-monitor none} to disable the default monitor.
2871 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
2872 "-qmp dev like -monitor but opens in 'control' mode\n",
2875 @item -qmp @var{dev}
2877 Like -monitor but opens in 'control' mode.
2879 DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
2880 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
2883 @item -qmp-pretty @var{dev}
2885 Like -qmp but uses pretty JSON formatting.
2888 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
2889 "-mon [chardev=]name[,mode=readline|control][,default]\n", QEMU_ARCH_ALL)
2891 @item -mon [chardev=]name[,mode=readline|control][,default]
2893 Setup monitor on chardev @var{name}.
2896 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
2897 "-debugcon dev redirect the debug console to char device 'dev'\n",
2900 @item -debugcon @var{dev}
2902 Redirect the debug console to host device @var{dev} (same devices as the
2903 serial port). The debug console is an I/O port which is typically port
2904 0xe9; writing to that I/O port sends output to this device.
2905 The default device is @code{vc} in graphical mode and @code{stdio} in
2909 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
2910 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
2912 @item -pidfile @var{file}
2914 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
2918 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
2919 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
2923 Run the emulation in single step mode.
2926 DEF("S", 0, QEMU_OPTION_S, \
2927 "-S freeze CPU at startup (use 'c' to start execution)\n",
2932 Do not start CPU at startup (you must type 'c' in the monitor).
2935 DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
2936 "-realtime [mlock=on|off]\n"
2937 " run qemu with realtime features\n"
2938 " mlock=on|off controls mlock support (default: on)\n",
2941 @item -realtime mlock=on|off
2943 Run qemu with realtime features.
2944 mlocking qemu and guest memory can be enabled via @option{mlock=on}
2945 (enabled by default).
2948 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
2949 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
2951 @item -gdb @var{dev}
2953 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
2954 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
2955 stdio are reasonable use case. The latter is allowing to start QEMU from
2956 within gdb and establish the connection via a pipe:
2958 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
2962 DEF("s", 0, QEMU_OPTION_s, \
2963 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
2968 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
2969 (@pxref{gdb_usage}).
2972 DEF("d", HAS_ARG, QEMU_OPTION_d, \
2973 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
2976 @item -d @var{item1}[,...]
2978 Enable logging of specified items. Use '-d help' for a list of log items.
2981 DEF("D", HAS_ARG, QEMU_OPTION_D, \
2982 "-D logfile output log to logfile (default stderr)\n",
2985 @item -D @var{logfile}
2987 Output log in @var{logfile} instead of to stderr
2990 DEF("L", HAS_ARG, QEMU_OPTION_L, \
2991 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2996 Set the directory for the BIOS, VGA BIOS and keymaps.
2999 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3000 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3002 @item -bios @var{file}
3004 Set the filename for the BIOS.
3007 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
3008 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
3012 Enable KVM full virtualization support. This option is only available
3013 if KVM support is enabled when compiling.
3016 DEF("enable-yagl", 0, QEMU_OPTION_enable_yagl, \
3017 "-enable-yagl enable OpenGLES passthrough support\n", QEMU_ARCH_ALL)
3020 @findex -enable-yagl
3021 Enable EGL and OpenGLES passthrough support. This option requires special
3022 libEGL, libGLES_CM and libGLESv2 to be installed on the guest OS. Corresponding
3023 EGL and openGLES calls on target system are translated to host openGL calls.
3026 DEF("enable-vigs", 0, QEMU_OPTION_enable_vigs, \
3027 "-enable-vigs enable VIGS support\n", QEMU_ARCH_ALL)
3030 @findex -enable-vigs
3031 Enables VIGS support.
3034 DEF("vigs-backend", HAS_ARG, QEMU_OPTION_vigs_backend,
3035 "-vigs-backend gl Select VIGS backend, default is gl\n", QEMU_ARCH_ALL)
3037 @item -vigs-backend @var{backend}
3038 @findex -vigs-backend
3039 Use @var{backend} as VIGS backend.
3042 DEF("enable-hax", 0, QEMU_OPTION_enable_hax, \
3043 "-enable-hax enable HAX virtualization support\n", QEMU_ARCH_I386)
3047 Enable HAX (Hardware-based Acceleration eXecution) support. When HAX support detected, emulator will enable it by default. This option will disable the default action
3048 HAX is only supported in MAC and Windows platform and is not conflict with KVM.
3051 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
3052 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
3053 DEF("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",
3057 DEF("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",
3062 @item -xen-domid @var{id}
3064 Specify xen guest domain @var{id} (XEN only).
3067 Create domain using xen hypercalls, bypassing xend.
3068 Warning: should not be used when xend is in use (XEN only).
3071 Attach to existing xen domain.
3072 xend will use this when starting QEMU (XEN only).
3075 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
3076 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
3080 Exit instead of rebooting.
3083 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
3084 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
3087 @findex -no-shutdown
3088 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3089 This allows for instance switching to monitor to commit changes to the
3093 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
3094 "-loadvm [tag|id]\n" \
3095 " start right away with a saved state (loadvm in monitor)\n",
3098 @item -loadvm @var{file}
3100 Start right away with a saved state (@code{loadvm} in monitor)
3104 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
3105 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
3110 Daemonize the QEMU process after initialization. QEMU will not detach from
3111 standard IO until it is ready to receive connections on any of its devices.
3112 This option is a useful way for external programs to launch QEMU without having
3113 to cope with initialization race conditions.
3116 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
3117 "-option-rom rom load a file, rom, into the option ROM space\n",
3120 @item -option-rom @var{file}
3122 Load the contents of @var{file} as an option ROM.
3123 This option is useful to load things like EtherBoot.
3126 HXCOMM Silently ignored for compatibility
3127 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
3129 HXCOMM Options deprecated by -rtc
3130 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
3131 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
3133 DEF("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",
3140 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3142 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3143 UTC or local time, respectively. @code{localtime} is required for correct date in
3144 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3145 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3147 By default the RTC is driven by the host system time. This allows using of the
3148 RTC as accurate reference clock inside the guest, specifically if the host
3149 time is smoothly following an accurate external reference clock, e.g. via NTP.
3150 If you want to isolate the guest time from the host, you can set @option{clock}
3151 to @code{rt} instead. To even prevent it from progressing during suspension,
3152 you can set it to @code{vm}.
3154 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3155 specifically with Windows' ACPI HAL. This option will try to figure out how
3156 many timer interrupts were not processed by the Windows guest and will
3160 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
3161 "-icount [shift=N|auto][,align=on|off][,sleep=no]\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)
3166 @item -icount [shift=@var{N}|auto]
3168 Enable virtual instruction counter. The virtual cpu will execute one
3169 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3170 then the virtual cpu speed will be automatically adjusted to keep virtual
3171 time within a few seconds of real time.
3173 When the virtual cpu is sleeping, the virtual time will advance at default
3174 speed unless @option{sleep=no} is specified.
3175 With @option{sleep=no}, the virtual time will jump to the next timer deadline
3176 instantly whenever the virtual cpu goes to sleep mode and will not advance
3177 if no timer is enabled. This behavior give deterministic execution times from
3178 the guest point of view.
3180 Note that while this option can give deterministic behavior, it does not
3181 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3182 order cores with complex cache hierarchies. The number of instructions
3183 executed often has little or no correlation with actual performance.
3185 @option{align=on} will activate the delay algorithm which will try to
3186 to synchronise the host clock and the virtual clock. The goal is to
3187 have a guest running at the real frequency imposed by the shift option.
3188 Whenever the guest clock is behind the host clock and if
3189 @option{align=on} is specified then we print a message to the user
3190 to inform about the delay.
3191 Currently this option does not work when @option{shift} is @code{auto}.
3192 Note: The sync algorithm will work for those shift values for which
3193 the guest clock runs ahead of the host clock. Typically this happens
3194 when the shift value is high (how high depends on the host machine).
3197 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
3198 "-watchdog model\n" \
3199 " enable virtual hardware watchdog [default=none]\n",
3202 @item -watchdog @var{model}
3204 Create a virtual hardware watchdog device. Once enabled (by a guest
3205 action), the watchdog must be periodically polled by an agent inside
3206 the guest or else the guest will be restarted. Choose a model for
3207 which your guest has drivers.
3209 The @var{model} is the model of hardware watchdog to emulate. Use
3210 @code{-watchdog help} to list available hardware models. Only one
3211 watchdog can be enabled for a guest.
3213 The following models may be available:
3216 iBASE 700 is a very simple ISA watchdog with a single timer.
3218 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3219 dual-timer watchdog.
3221 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3222 (currently KVM only).
3226 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
3227 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
3228 " action when watchdog fires [default=reset]\n",
3231 @item -watchdog-action @var{action}
3232 @findex -watchdog-action
3234 The @var{action} controls what QEMU will do when the watchdog timer
3237 @code{reset} (forcefully reset the guest).
3238 Other possible actions are:
3239 @code{shutdown} (attempt to gracefully shutdown the guest),
3240 @code{poweroff} (forcefully poweroff the guest),
3241 @code{pause} (pause the guest),
3242 @code{debug} (print a debug message and continue), or
3243 @code{none} (do nothing).
3245 Note that the @code{shutdown} action requires that the guest responds
3246 to ACPI signals, which it may not be able to do in the sort of
3247 situations where the watchdog would have expired, and thus
3248 @code{-watchdog-action shutdown} is not recommended for production use.
3253 @item -watchdog i6300esb -watchdog-action pause
3254 @itemx -watchdog ib700
3258 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
3259 "-echr chr set terminal escape character instead of ctrl-a\n",
3263 @item -echr @var{numeric_ascii_value}
3265 Change the escape character used for switching to the monitor when using
3266 monitor and serial sharing. The default is @code{0x01} when using the
3267 @code{-nographic} option. @code{0x01} is equal to pressing
3268 @code{Control-a}. You can select a different character from the ascii
3269 control keys where 1 through 26 map to Control-a through Control-z. For
3270 instance you could use the either of the following to change the escape
3271 character to Control-t.
3278 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
3279 "-virtioconsole c\n" \
3280 " set virtio console\n", QEMU_ARCH_ALL)
3282 @item -virtioconsole @var{c}
3283 @findex -virtioconsole
3286 This option is maintained for backward compatibility.
3288 Please use @code{-device virtconsole} for the new way of invocation.
3291 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
3292 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
3295 @findex -show-cursor
3299 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
3300 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
3302 @item -tb-size @var{n}
3307 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
3308 "-incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]\n" \
3309 "-incoming rdma:host:port[,ipv4][,ipv6]\n" \
3310 "-incoming unix:socketpath\n" \
3311 " prepare for incoming migration, listen on\n" \
3312 " specified protocol and socket address\n" \
3313 "-incoming fd:fd\n" \
3314 "-incoming exec:cmdline\n" \
3315 " accept incoming migration on given file descriptor\n" \
3316 " or from given external command\n" \
3317 "-incoming defer\n" \
3318 " wait for the URI to be specified via migrate_incoming\n",
3321 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3322 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3324 Prepare for incoming migration, listen on a given tcp port.
3326 @item -incoming unix:@var{socketpath}
3327 Prepare for incoming migration, listen on a given unix socket.
3329 @item -incoming fd:@var{fd}
3330 Accept incoming migration from a given filedescriptor.
3332 @item -incoming exec:@var{cmdline}
3333 Accept incoming migration as an output from specified external command.
3335 @item -incoming defer
3336 Wait for the URI to be specified via migrate_incoming. The monitor can
3337 be used to change settings (such as migration parameters) prior to issuing
3338 the migrate_incoming to allow the migration to begin.
3341 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
3342 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
3346 Don't create default devices. Normally, QEMU sets the default devices like serial
3347 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
3348 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
3353 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
3354 "-chroot dir chroot to dir just before starting the VM\n",
3358 @item -chroot @var{dir}
3360 Immediately before starting guest execution, chroot to the specified
3361 directory. Especially useful in combination with -runas.
3365 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
3366 "-runas user change to user id user just before starting the VM\n",
3370 @item -runas @var{user}
3372 Immediately before starting guest execution, drop root privileges, switching
3373 to the specified user.
3376 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
3377 "-prom-env variable=value\n"
3378 " set OpenBIOS nvram variables\n",
3379 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3381 @item -prom-env @var{variable}=@var{value}
3383 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
3385 DEF("semihosting", 0, QEMU_OPTION_semihosting,
3386 "-semihosting semihosting mode\n",
3387 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3391 @findex -semihosting
3392 Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).
3394 DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
3395 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]\n" \
3396 " semihosting configuration\n",
3397 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3400 @item -semihosting-config [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
3401 @findex -semihosting-config
3402 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).
3404 @item target=@code{native|gdb|auto}
3405 Defines where the semihosting calls will be addressed, to QEMU (@code{native})
3406 or to GDB (@code{gdb}). The default is @code{auto}, which means @code{gdb}
3407 during debug sessions and @code{native} otherwise.
3408 @item arg=@var{str1},arg=@var{str2},...
3409 Allows the user to pass input arguments, and can be used multiple times to build
3410 up a list. The old-style @code{-kernel}/@code{-append} method of passing a
3411 command line is still supported for backward compatibility. If both the
3412 @code{--semihosting-config arg} and the @code{-kernel}/@code{-append} are
3413 specified, the former is passed to semihosting as it always takes precedence.
3416 DEF("old-param", 0, QEMU_OPTION_old_param,
3417 "-old-param old param mode\n", QEMU_ARCH_ARM)
3420 @findex -old-param (ARM)
3421 Old param mode (ARM only).
3424 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
3425 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n",
3428 @item -sandbox @var{arg}
3430 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
3431 disable it. The default is 'off'.
3434 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
3435 "-readconfig <file>\n", QEMU_ARCH_ALL)
3437 @item -readconfig @var{file}
3439 Read device configuration from @var{file}. This approach is useful when you want to spawn
3440 QEMU process with many command line options but you don't want to exceed the command line
3443 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3444 "-writeconfig <file>\n"
3445 " read/write config file\n", QEMU_ARCH_ALL)
3447 @item -writeconfig @var{file}
3448 @findex -writeconfig
3449 Write device configuration to @var{file}. The @var{file} can be either filename to save
3450 command line and device configuration into file or dash @code{-}) character to print the
3451 output to stdout. This can be later used as input file for @code{-readconfig} option.
3453 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
3455 " do not load default config files at startup\n",
3459 @findex -nodefconfig
3460 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
3461 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
3463 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3465 " do not load user-provided config files at startup\n",
3468 @item -no-user-config
3469 @findex -no-user-config
3470 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3471 config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config
3472 files from @var{datadir}.
3474 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
3475 "-trace [events=<file>][,file=<file>]\n"
3476 " specify tracing options\n",
3479 HXCOMM This line is not accurate, as some sub-options are backend-specific but
3480 HXCOMM HX does not support conditional compilation of text.
3481 @item -trace [events=@var{file}][,file=@var{file}]
3484 Specify tracing options.
3487 @item events=@var{file}
3488 Immediately enable events listed in @var{file}.
3489 The file must contain one event name (as listed in the @var{trace-events} file)
3491 This option is only available if QEMU has been compiled with
3492 either @var{simple} or @var{stderr} tracing backend.
3493 @item file=@var{file}
3494 Log output traces to @var{file}.
3496 This option is only available if QEMU has been compiled with
3497 the @var{simple} tracing backend.
3501 DEF("disable-skin", 0, QEMU_OPTION_disable_skin, \
3503 " do not start with java skin process\n",
3507 @findex -disable-skin
3510 DEF("enable-suspend", 0, QEMU_OPTION_enable_suspend, "", QEMU_ARCH_ALL)
3512 @item -enable-suspend
3513 @findex -enable-suspend
3514 Enable suspend power state. Default is disable.
3518 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
3519 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
3522 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
3523 "-enable-fips enable FIPS 140-2 compliance\n",
3528 @findex -enable-fips
3529 Enable FIPS 140-2 compliance mode.
3532 HXCOMM Deprecated by -machine accel=tcg property
3533 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
3535 HXCOMM Deprecated by kvm-pit driver properties
3536 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
3539 HXCOMM Deprecated (ignored)
3540 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
3542 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
3543 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
3545 HXCOMM Deprecated (ignored)
3546 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
3548 DEF("msg", HAS_ARG, QEMU_OPTION_msg,
3549 "-msg timestamp[=on|off]\n"
3550 " change the format of messages\n"
3551 " on|off controls leading timestamps (default:on)\n",
3554 @item -msg timestamp[=on|off]
3556 prepend a timestamp to each log message.(default:on)
3559 DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
3560 "-dump-vmstate <file>\n"
3561 " Output vmstate information in JSON format to file.\n"
3562 " Use the scripts/vmstate-static-checker.py file to\n"
3563 " check for possible regressions in migration code\n"
3564 " by comparing two such vmstate dumps.",
3567 @item -dump-vmstate @var{file}
3568 @findex -dump-vmstate
3569 Dump json-encoded vmstate information for current machine type to file
3573 DEFHEADING(Generic object creation)
3575 DEF("object", HAS_ARG, QEMU_OPTION_object,
3576 "-object TYPENAME[,PROP1=VALUE1,...]\n"
3577 " create a new object of type TYPENAME setting properties\n"
3578 " in the order they are specified. Note that the 'id'\n"
3579 " property must be set. These objects are placed in the\n"
3580 " '/objects' path.\n",
3583 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
3585 Create a new object of type @var{typename} setting properties
3586 in the order they are specified. Note that the 'id'
3587 property must be set. These objects are placed in the
3592 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
3594 Creates a memory file backend object, which can be used to back
3595 the guest RAM with huge pages. The @option{id} parameter is a
3596 unique ID that will be used to reference this memory region
3597 when configuring the @option{-numa} argument. The @option{size}
3598 option provides the size of the memory region, and accepts
3599 common suffixes, eg @option{500M}. The @option{mem-path} provides
3600 the path to either a shared memory or huge page filesystem mount.
3601 The @option{share} boolean option determines whether the memory
3602 region is marked as private to QEMU, or shared. The latter allows
3603 a co-operating external process to access the QEMU memory region.
3605 @item -object rng-random,id=@var{id},filename=@var{/dev/random}
3607 Creates a random number generator backend which obtains entropy from
3608 a device on the host. The @option{id} parameter is a unique ID that
3609 will be used to reference this entropy backend from the @option{virtio-rng}
3610 device. The @option{filename} parameter specifies which file to obtain
3611 entropy from and if omitted defaults to @option{/dev/random}.
3613 @item -object rng-egd,id=@var{id},chardev=@var{chardevid}
3615 Creates a random number generator backend which obtains entropy from
3616 an external daemon running on the host. The @option{id} parameter is
3617 a unique ID that will be used to reference this entropy backend from
3618 the @option{virtio-rng} device. The @option{chardev} parameter is
3619 the unique ID of a character device backend that provides the connection
3627 HXCOMM This is the last statement. Insert new options before this line!