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 " kvm_shadow_mem=size of KVM shadow MMU\n"
37 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
38 " mem-merge=on|off controls memory merge support (default: on)\n",
41 @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
43 Select the emulated machine by @var{name}. Use @code{-machine help} to list
44 available machines. Supported machine properties are:
46 @item accel=@var{accels1}[:@var{accels2}[:...]]
47 This is used to enable an accelerator. Depending on the target architecture,
48 kvm, xen, or tcg can be available. By default, tcg is used. If there is more
49 than one accelerator specified, the next one is used if the previous one fails
51 @item kernel_irqchip=on|off
52 Enables in-kernel irqchip support for the chosen accelerator when available.
53 @item kvm_shadow_mem=size
54 Defines the size of the KVM shadow MMU.
55 @item dump-guest-core=on|off
56 Include guest memory in a core dump. The default is on.
57 @item mem-merge=on|off
58 Enables or disables memory merge support. This feature, when supported by
59 the host, de-duplicates identical memory pages among VMs instances
64 HXCOMM Deprecated by -machine
65 DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
67 DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
68 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
70 @item -cpu @var{model}
72 Select CPU model (@code{-cpu help} for list and additional feature selection)
75 DEF("smp", HAS_ARG, QEMU_OPTION_smp,
76 "-smp n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
77 " set the number of CPUs to 'n' [default=1]\n"
78 " maxcpus= maximum number of total cpus, including\n"
79 " offline CPUs for hotplug, etc\n"
80 " cores= number of CPU cores on one socket\n"
81 " threads= number of threads on one CPU core\n"
82 " sockets= number of discrete sockets in the system\n",
85 @item -smp @var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
87 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
88 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
90 For the PC target, the number of @var{cores} per socket, the number
91 of @var{threads} per cores and the total number of @var{sockets} can be
92 specified. Missing values will be computed. If any on the three values is
93 given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
94 specifies the maximum number of hotpluggable CPUs.
97 DEF("numa", HAS_ARG, QEMU_OPTION_numa,
98 "-numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]\n", QEMU_ARCH_ALL)
100 @item -numa @var{opts}
102 Simulate a multi node NUMA system. If mem and cpus are omitted, resources
106 DEF("fda", HAS_ARG, QEMU_OPTION_fda,
107 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
108 DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
110 @item -fda @var{file}
111 @item -fdb @var{file}
114 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). You can
115 use the host floppy by using @file{/dev/fd0} as filename (@pxref{host_drives}).
118 DEF("hda", HAS_ARG, QEMU_OPTION_hda,
119 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
120 DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
121 DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
122 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
123 DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
125 @item -hda @var{file}
126 @item -hdb @var{file}
127 @item -hdc @var{file}
128 @item -hdd @var{file}
133 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
136 DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
137 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
140 @item -cdrom @var{file}
142 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and
143 @option{-cdrom} at the same time). You can use the host CD-ROM by
144 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
147 DEF("drive", HAS_ARG, QEMU_OPTION_drive,
148 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
149 " [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
150 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
151 " [,serial=s][,addr=A][,id=name][,aio=threads|native]\n"
152 " [,readonly=on|off][,copy-on-read=on|off]\n"
153 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]][[,iops=i]|[[,iops_rd=r][,iops_wr=w]]\n"
154 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
156 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
159 Define a new drive. Valid options are:
162 @item file=@var{file}
163 This option defines which disk image (@pxref{disk_images}) to use with
164 this drive. If the filename contains comma, you must double it
165 (for instance, "file=my,,file" to use file "my,file").
167 Special files such as iSCSI devices can be specified using protocol
168 specific URLs. See the section for "Device URL Syntax" for more information.
169 @item if=@var{interface}
170 This option defines on which type on interface the drive is connected.
171 Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio.
172 @item bus=@var{bus},unit=@var{unit}
173 These options define where is connected the drive by defining the bus number and
175 @item index=@var{index}
176 This option defines where is connected the drive by using an index in the list
177 of available connectors of a given interface type.
178 @item media=@var{media}
179 This option defines the type of the media: disk or cdrom.
180 @item cyls=@var{c},heads=@var{h},secs=@var{s}[,trans=@var{t}]
181 These options have the same definition as they have in @option{-hdachs}.
182 @item snapshot=@var{snapshot}
183 @var{snapshot} is "on" or "off" and allows to enable snapshot for given drive (see @option{-snapshot}).
184 @item cache=@var{cache}
185 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
187 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
188 @item format=@var{format}
189 Specify which disk @var{format} will be used rather than detecting
190 the format. Can be used to specifiy format=raw to avoid interpreting
191 an untrusted format header.
192 @item serial=@var{serial}
193 This option specifies the serial number to assign to the device.
194 @item addr=@var{addr}
195 Specify the controller's PCI address (if=virtio only).
196 @item werror=@var{action},rerror=@var{action}
197 Specify which @var{action} to take on write and read errors. Valid actions are:
198 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
199 "report" (report the error to the guest), "enospc" (pause QEMU only if the
200 host disk is full; report the error to the guest otherwise).
201 The default setting is @option{werror=enospc} and @option{rerror=report}.
203 Open drive @option{file} as read-only. Guest write attempts will fail.
204 @item copy-on-read=@var{copy-on-read}
205 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
206 file sectors into the image file.
209 By default, the @option{cache=writeback} mode is used. It will report data
210 writes as completed as soon as the data is present in the host page cache.
211 This is safe as long as your guest OS makes sure to correctly flush disk caches
212 where needed. If your guest OS does not handle volatile disk write caches
213 correctly and your host crashes or loses power, then the guest may experience
216 For such guests, you should consider using @option{cache=writethrough}. This
217 means that the host page cache will be used to read and write data, but write
218 notification will be sent to the guest only after QEMU has made sure to flush
219 each write to the disk. Be aware that this has a major impact on performance.
221 The host page cache can be avoided entirely with @option{cache=none}. This will
222 attempt to do disk IO directly to the guest's memory. QEMU may still perform
223 an internal copy of the data. Note that this is considered a writeback mode and
224 the guest OS must handle the disk write cache correctly in order to avoid data
225 corruption on host crashes.
227 The host page cache can be avoided while only sending write notifications to
228 the guest when the data has been flushed to the disk using
229 @option{cache=directsync}.
231 In case you don't care about data integrity over host failures, use
232 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
233 data to the disk but can instead keep things in cache. If anything goes wrong,
234 like your host losing power, the disk storage getting disconnected accidentally,
235 etc. your image will most probably be rendered unusable. When using
236 the @option{-snapshot} option, unsafe caching is always used.
238 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
239 useful when the backing file is over a slow network. By default copy-on-read
242 Instead of @option{-cdrom} you can use:
244 qemu-system-i386 -drive file=file,index=2,media=cdrom
247 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
250 qemu-system-i386 -drive file=file,index=0,media=disk
251 qemu-system-i386 -drive file=file,index=1,media=disk
252 qemu-system-i386 -drive file=file,index=2,media=disk
253 qemu-system-i386 -drive file=file,index=3,media=disk
256 You can open an image using pre-opened file descriptors from an fd set:
259 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
260 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
261 -drive file=/dev/fdset/2,index=0,media=disk
264 You can connect a CDROM to the slave of ide0:
266 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
269 If you don't specify the "file=" argument, you define an empty drive:
271 qemu-system-i386 -drive if=ide,index=1,media=cdrom
274 You can connect a SCSI disk with unit ID 6 on the bus #0:
276 qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6
279 Instead of @option{-fda}, @option{-fdb}, you can use:
281 qemu-system-i386 -drive file=file,index=0,if=floppy
282 qemu-system-i386 -drive file=file,index=1,if=floppy
285 By default, @var{interface} is "ide" and @var{index} is automatically
288 qemu-system-i386 -drive file=a -drive file=b"
292 qemu-system-i386 -hda a -hdb b
296 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
297 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
298 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
300 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
303 Add a file descriptor to an fd set. Valid options are:
307 This option defines the file descriptor of which a duplicate is added to fd set.
308 The file descriptor cannot be stdin, stdout, or stderr.
310 This option defines the ID of the fd set to add the file descriptor to.
311 @item opaque=@var{opaque}
312 This option defines a free-form string that can be used to describe @var{fd}.
315 You can open an image using pre-opened file descriptors from an fd set:
318 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
319 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
320 -drive file=/dev/fdset/2,index=0,media=disk
324 DEF("set", HAS_ARG, QEMU_OPTION_set,
325 "-set group.id.arg=value\n"
326 " set <arg> parameter for item <id> of type <group>\n"
327 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
329 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
331 Set parameter @var{arg} for item @var{id} of type @var{group}\n"
334 DEF("global", HAS_ARG, QEMU_OPTION_global,
335 "-global driver.prop=value\n"
336 " set a global default for a driver property\n",
339 @item -global @var{driver}.@var{prop}=@var{value}
341 Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
344 qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk
347 In particular, you can use this to set driver properties for devices which are
348 created automatically by the machine model. To create a device which is not
349 created automatically and set properties on it, use -@option{device}.
352 DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
353 "-mtdblock file use 'file' as on-board Flash memory image\n",
356 @item -mtdblock @var{file}
358 Use @var{file} as on-board Flash memory image.
361 DEF("sd", HAS_ARG, QEMU_OPTION_sd,
362 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
366 Use @var{file} as SecureDigital card image.
369 DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
370 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
372 @item -pflash @var{file}
374 Use @var{file} as a parallel flash image.
377 DEF("boot", HAS_ARG, QEMU_OPTION_boot,
378 "-boot [order=drives][,once=drives][,menu=on|off]\n"
379 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time]\n"
380 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
381 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
382 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
383 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
386 @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}]
388 Specify boot order @var{drives} as a string of drive letters. Valid
389 drive letters depend on the target achitecture. The x86 PC uses: a, b
390 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p (Etherboot
391 from network adapter 1-4), hard disk boot is the default. To apply a
392 particular boot order only on the first startup, specify it via
395 Interactive boot menus/prompts can be enabled via @option{menu=on} as far
396 as firmware/BIOS supports them. The default is non-interactive boot.
398 A splash picture could be passed to bios, enabling user to show it as logo,
399 when option splash=@var{sp_name} is given and menu=on, If firmware/BIOS
400 supports them. Currently Seabios for X86 system support it.
401 limitation: The splash file could be a jpeg file or a BMP file in 24 BPP
402 format(true color). The resolution should be supported by the SVGA mode, so
403 the recommended is 320x240, 640x480, 800x640.
405 A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
406 when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
407 reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
411 # try to boot from network first, then from hard disk
412 qemu-system-i386 -boot order=nc
413 # boot from CD-ROM first, switch back to default order after reboot
414 qemu-system-i386 -boot once=d
415 # boot with a splash picture for 5 seconds.
416 qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
419 Note: The legacy format '-boot @var{drives}' is still supported but its
420 use is discouraged as it may be removed from future versions.
423 DEF("snapshot", 0, QEMU_OPTION_snapshot,
424 "-snapshot write to temporary files instead of disk image files\n",
429 Write to temporary files instead of disk image files. In this case,
430 the raw disk image you use is not written back. You can however force
431 the write back by pressing @key{C-a s} (@pxref{disk_images}).
434 DEF("m", HAS_ARG, QEMU_OPTION_m,
435 "-m megs set virtual RAM size to megs MB [default="
436 stringify(DEFAULT_RAM_SIZE) "]\n", QEMU_ARCH_ALL)
440 Set virtual RAM size to @var{megs} megabytes. Default is 128 MiB. Optionally,
441 a suffix of ``M'' or ``G'' can be used to signify a value in megabytes or
442 gigabytes respectively.
445 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
446 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
448 @item -mem-path @var{path}
450 Allocate guest RAM from a temporarily created file in @var{path}.
454 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
455 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
459 @findex -mem-prealloc
460 Preallocate memory when using -mem-path.
464 DEF("k", HAS_ARG, QEMU_OPTION_k,
465 "-k language use keyboard layout (for example 'fr' for French)\n",
468 @item -k @var{language}
470 Use keyboard layout @var{language} (for example @code{fr} for
471 French). This option is only needed where it is not easy to get raw PC
472 keycodes (e.g. on Macs, with some X11 servers or with a VNC
473 display). You don't normally need to use it on PC/Linux or PC/Windows
476 The available layouts are:
478 ar de-ch es fo fr-ca hu ja mk no pt-br sv
479 da en-gb et fr fr-ch is lt nl pl ru th
480 de en-us fi fr-be hr it lv nl-be pt sl tr
483 The default is @code{en-us}.
487 DEF("audio-help", 0, QEMU_OPTION_audio_help,
488 "-audio-help print list of audio drivers and their options\n",
493 Will show the audio subsystem help: list of drivers, tunable
497 DEF("soundhw", HAS_ARG, QEMU_OPTION_soundhw,
498 "-soundhw c1,... enable audio support\n"
499 " and only specified sound cards (comma separated list)\n"
500 " use '-soundhw help' to get the list of supported cards\n"
501 " use '-soundhw all' to enable all of them\n", QEMU_ARCH_ALL)
503 @item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
505 Enable audio and selected sound hardware. Use 'help' to print all
506 available sound hardware.
509 qemu-system-i386 -soundhw sb16,adlib disk.img
510 qemu-system-i386 -soundhw es1370 disk.img
511 qemu-system-i386 -soundhw ac97 disk.img
512 qemu-system-i386 -soundhw hda disk.img
513 qemu-system-i386 -soundhw all disk.img
514 qemu-system-i386 -soundhw help
517 Note that Linux's i810_audio OSS kernel (for AC97) module might
518 require manually specifying clocking.
521 modprobe i810_audio clocking=48000
525 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
526 "-balloon none disable balloon device\n"
527 "-balloon virtio[,addr=str]\n"
528 " enable virtio balloon device (default)\n", QEMU_ARCH_ALL)
532 Disable balloon device.
533 @item -balloon virtio[,addr=@var{addr}]
534 Enable virtio balloon device (default), optionally with PCI address
538 DEF("device", HAS_ARG, QEMU_OPTION_device,
539 "-device driver[,prop[=value][,...]]\n"
540 " add device (based on driver)\n"
541 " prop=value,... sets driver properties\n"
542 " use '-device help' to print all possible drivers\n"
543 " use '-device driver,help' to print all possible properties\n",
546 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
548 Add device @var{driver}. @var{prop}=@var{value} sets driver
549 properties. Valid properties depend on the driver. To get help on
550 possible drivers and properties, use @code{-device help} and
551 @code{-device @var{driver},help}.
554 DEF("name", HAS_ARG, QEMU_OPTION_name,
555 "-name string1[,process=string2]\n"
556 " set the name of the guest\n"
557 " string1 sets the window title and string2 the process name (on Linux)\n",
560 @item -name @var{name}
562 Sets the @var{name} of the guest.
563 This name will be displayed in the SDL window caption.
564 The @var{name} will also be used for the VNC server.
565 Also optionally set the top visible process name in Linux.
568 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
569 "-uuid %08x-%04x-%04x-%04x-%012x\n"
570 " specify machine UUID\n", QEMU_ARCH_ALL)
572 @item -uuid @var{uuid}
582 DEFHEADING(USB options:)
587 DEF("usb", 0, QEMU_OPTION_usb,
588 "-usb enable the USB driver (will be the default soon)\n",
593 Enable the USB driver (will be the default soon)
596 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
597 "-usbdevice name add the host or guest USB device 'name'\n",
601 @item -usbdevice @var{devname}
603 Add the USB device @var{devname}. @xref{usb_devices}.
608 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
611 Pointer device that uses absolute coordinates (like a touchscreen). This
612 means QEMU is able to report the mouse position without having to grab the
613 mouse. Also overrides the PS/2 mouse emulation when activated.
615 @item disk:[format=@var{format}]:@var{file}
616 Mass storage device based on file. The optional @var{format} argument
617 will be used rather than detecting the format. Can be used to specifiy
618 @code{format=raw} to avoid interpreting an untrusted format header.
620 @item host:@var{bus}.@var{addr}
621 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
623 @item host:@var{vendor_id}:@var{product_id}
624 Pass through the host device identified by @var{vendor_id}:@var{product_id}
627 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
628 Serial converter to host character device @var{dev}, see @code{-serial} for the
632 Braille device. This will use BrlAPI to display the braille output on a real
635 @item net:@var{options}
636 Network adapter that supports CDC ethernet and RNDIS protocols.
646 DEFHEADING(File system options:)
651 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
652 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
653 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
658 @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}]
660 Define a new file system device. Valid options are:
663 This option specifies the fs driver backend to use.
664 Currently "local", "handle" and "proxy" file system drivers are supported.
666 Specifies identifier for this device
667 @item path=@var{path}
668 Specifies the export path for the file system device. Files under
669 this path will be available to the 9p client on the guest.
670 @item security_model=@var{security_model}
671 Specifies the security model to be used for this export path.
672 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
673 In "passthrough" security model, files are stored using the same
674 credentials as they are created on the guest. This requires QEMU
675 to run as root. In "mapped-xattr" security model, some of the file
676 attributes like uid, gid, mode bits and link target are stored as
677 file attributes. For "mapped-file" these attributes are stored in the
678 hidden .virtfs_metadata directory. Directories exported by this security model cannot
679 interact with other unix tools. "none" security model is same as
680 passthrough except the sever won't report failures if it fails to
681 set file attributes like ownership. Security model is mandatory
682 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
683 security model as a parameter.
684 @item writeout=@var{writeout}
685 This is an optional argument. The only supported value is "immediate".
686 This means that host page cache will be used to read and write data but
687 write notification will be sent to the guest only when the data has been
688 reported as written by the storage subsystem.
690 Enables exporting 9p share as a readonly mount for guests. By default
691 read-write access is given.
692 @item socket=@var{socket}
693 Enables proxy filesystem driver to use passed socket file for communicating
694 with virtfs-proxy-helper
695 @item sock_fd=@var{sock_fd}
696 Enables proxy filesystem driver to use passed socket descriptor for
697 communicating with virtfs-proxy-helper. Usually a helper like libvirt
698 will create socketpair and pass one of the fds as sock_fd
701 -fsdev option is used along with -device driver "virtio-9p-pci".
702 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
703 Options for virtio-9p-pci driver are:
706 Specifies the id value specified along with -fsdev option
707 @item mount_tag=@var{mount_tag}
708 Specifies the tag name to be used by the guest to mount this export point
718 DEFHEADING(Virtual File system pass-through options:)
723 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
724 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
725 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
730 @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}]
733 The general form of a Virtual File system pass-through options are:
736 This option specifies the fs driver backend to use.
737 Currently "local", "handle" and "proxy" file system drivers are supported.
739 Specifies identifier for this device
740 @item path=@var{path}
741 Specifies the export path for the file system device. Files under
742 this path will be available to the 9p client on the guest.
743 @item security_model=@var{security_model}
744 Specifies the security model to be used for this export path.
745 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
746 In "passthrough" security model, files are stored using the same
747 credentials as they are created on the guest. This requires QEMU
748 to run as root. In "mapped-xattr" security model, some of the file
749 attributes like uid, gid, mode bits and link target are stored as
750 file attributes. For "mapped-file" these attributes are stored in the
751 hidden .virtfs_metadata directory. Directories exported by this security model cannot
752 interact with other unix tools. "none" security model is same as
753 passthrough except the sever won't report failures if it fails to
754 set file attributes like ownership. Security model is mandatory only
755 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
756 model as a parameter.
757 @item writeout=@var{writeout}
758 This is an optional argument. The only supported value is "immediate".
759 This means that host page cache will be used to read and write data but
760 write notification will be sent to the guest only when the data has been
761 reported as written by the storage subsystem.
763 Enables exporting 9p share as a readonly mount for guests. By default
764 read-write access is given.
765 @item socket=@var{socket}
766 Enables proxy filesystem driver to use passed socket file for
767 communicating with virtfs-proxy-helper. Usually a helper like libvirt
768 will create socketpair and pass one of the fds as sock_fd
770 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
771 descriptor for interfacing with virtfs-proxy-helper
775 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
776 "-virtfs_synth Create synthetic file system image\n",
780 @findex -virtfs_synth
781 Create synthetic file system image
789 DEFHEADING(Display options:)
794 DEF("display", HAS_ARG, QEMU_OPTION_display,
795 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
796 " [,window_close=on|off]|curses|none|\n"
797 " vnc=<display>[,<optargs>]\n"
798 " select display type\n", QEMU_ARCH_ALL)
800 @item -display @var{type}
802 Select type of display to use. This option is a replacement for the
803 old style -sdl/-curses/... options. Valid values for @var{type} are
806 Display video output via SDL (usually in a separate graphics
807 window; see the SDL documentation for other possibilities).
809 Display video output via curses. For graphics device models which
810 support a text mode, QEMU can display this output using a
811 curses/ncurses interface. Nothing is displayed when the graphics
812 device is in graphical mode or if the graphics device does not support
813 a text mode. Generally only the VGA device models support text mode.
815 Do not display video output. The guest will still see an emulated
816 graphics card, but its output will not be displayed to the QEMU
817 user. This option differs from the -nographic option in that it
818 only affects what is done with video output; -nographic also changes
819 the destination of the serial and parallel port data.
821 Start a VNC server on display <arg>
825 DEF("nographic", 0, QEMU_OPTION_nographic,
826 "-nographic disable graphical output and redirect serial I/Os to console\n",
831 Normally, QEMU uses SDL to display the VGA output. With this option,
832 you can totally disable graphical output so that QEMU is a simple
833 command line application. The emulated serial port is redirected on
834 the console. Therefore, you can still use QEMU to debug a Linux kernel
835 with a serial console.
838 DEF("curses", 0, QEMU_OPTION_curses,
839 "-curses use a curses/ncurses interface instead of SDL\n",
844 Normally, QEMU uses SDL to display the VGA output. With this option,
845 QEMU can display the VGA output when in text mode using a
846 curses/ncurses interface. Nothing is displayed in graphical mode.
849 DEF("no-frame", 0, QEMU_OPTION_no_frame,
850 "-no-frame open SDL window without a frame and window decorations\n",
855 Do not use decorations for SDL windows and start them using the whole
856 available screen space. This makes the using QEMU in a dedicated desktop
857 workspace more convenient.
860 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
861 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
866 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
867 affects the special keys (for fullscreen, monitor-mode switching, etc).
870 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
871 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
876 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
877 affects the special keys (for fullscreen, monitor-mode switching, etc).
880 DEF("no-quit", 0, QEMU_OPTION_no_quit,
881 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
885 Disable SDL window close capability.
888 DEF("sdl", 0, QEMU_OPTION_sdl,
889 "-sdl enable SDL\n", QEMU_ARCH_ALL)
896 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
897 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
898 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
899 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
900 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6]\n"
901 " [,tls-ciphers=<list>]\n"
902 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
903 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
904 " [,sasl][,password=<secret>][,disable-ticketing]\n"
905 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
906 " [,jpeg-wan-compression=[auto|never|always]]\n"
907 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
908 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
909 " [,agent-mouse=[on|off]][,playback-compression=[on|off]]\n"
910 " [,seamless-migration=[on|off]]\n"
912 " at least one of {port, tls-port} is mandatory\n",
915 @item -spice @var{option}[,@var{option}[,...]]
917 Enable the spice remote desktop protocol. Valid options are
922 Set the TCP port spice is listening on for plaintext channels.
925 Set the IP address spice is listening on. Default is any address.
929 Force using the specified IP version.
931 @item password=<secret>
932 Set the password you need to authenticate.
935 Require that the client use SASL to authenticate with the spice.
936 The exact choice of authentication method used is controlled from the
937 system / user's SASL configuration file for the 'qemu' service. This
938 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
939 unprivileged user, an environment variable SASL_CONF_PATH can be used
940 to make it search alternate locations for the service config.
941 While some SASL auth methods can also provide data encryption (eg GSSAPI),
942 it is recommended that SASL always be combined with the 'tls' and
943 'x509' settings to enable use of SSL and server certificates. This
944 ensures a data encryption preventing compromise of authentication
947 @item disable-ticketing
948 Allow client connects without authentication.
950 @item disable-copy-paste
951 Disable copy paste between the client and the guest.
954 Set the TCP port spice is listening on for encrypted channels.
957 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
959 @item x509-key-file=<file>
960 @item x509-key-password=<file>
961 @item x509-cert-file=<file>
962 @item x509-cacert-file=<file>
963 @item x509-dh-key-file=<file>
964 The x509 file names can also be configured individually.
966 @item tls-ciphers=<list>
967 Specify which ciphers to use.
969 @item tls-channel=[main|display|cursor|inputs|record|playback]
970 @item plaintext-channel=[main|display|cursor|inputs|record|playback]
971 Force specific channel to be used with or without TLS encryption. The
972 options can be specified multiple times to configure multiple
973 channels. The special name "default" can be used to set the default
974 mode. For channels which are not explicitly forced into one mode the
975 spice client is allowed to pick tls/plaintext as he pleases.
977 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
978 Configure image compression (lossless).
981 @item jpeg-wan-compression=[auto|never|always]
982 @item zlib-glz-wan-compression=[auto|never|always]
983 Configure wan image compression (lossy for slow links).
986 @item streaming-video=[off|all|filter]
987 Configure video stream detection. Default is filter.
989 @item agent-mouse=[on|off]
990 Enable/disable passing mouse events via vdagent. Default is on.
992 @item playback-compression=[on|off]
993 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
995 @item seamless-migration=[on|off]
996 Enable/disable spice seamless migration. Default is off.
1001 DEF("portrait", 0, QEMU_OPTION_portrait,
1002 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1007 Rotate graphical output 90 deg left (only PXA LCD).
1010 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1011 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1014 @item -rotate @var{deg}
1016 Rotate graphical output some deg left (only PXA LCD).
1019 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1020 "-vga [std|cirrus|vmware|qxl|xenfb|none]\n"
1021 " select video card type\n", QEMU_ARCH_ALL)
1023 @item -vga @var{type}
1025 Select type of VGA card to emulate. Valid values for @var{type} are
1028 Cirrus Logic GD5446 Video card. All Windows versions starting from
1029 Windows 95 should recognize and use this graphic card. For optimal
1030 performances, use 16 bit color depth in the guest and the host OS.
1031 (This one is the default)
1033 Standard VGA card with Bochs VBE extensions. If your guest OS
1034 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1035 to use high resolution modes (>= 1280x1024x16) then you should use
1038 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1039 recent XFree86/XOrg server or Windows guest with a driver for this
1042 QXL paravirtual graphic card. It is VGA compatible (including VESA
1043 2.0 VBE support). Works best with qxl guest drivers installed though.
1044 Recommended choice when using the spice protocol.
1050 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1051 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1054 @findex -full-screen
1055 Start in full screen.
1058 DEF("g", 1, QEMU_OPTION_g ,
1059 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1060 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1062 @item -g @var{width}x@var{height}[x@var{depth}]
1064 Set the initial graphical resolution and depth (PPC, SPARC only).
1067 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1068 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL)
1070 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1072 Normally, QEMU uses SDL to display the VGA output. With this option,
1073 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1074 display over the VNC session. It is very useful to enable the usb
1075 tablet device when using this option (option @option{-usbdevice
1076 tablet}). When using the VNC display, you must use the @option{-k}
1077 parameter to set the keyboard layout if you are not using en-us. Valid
1078 syntax for the @var{display} is
1082 @item @var{host}:@var{d}
1084 TCP connections will only be allowed from @var{host} on display @var{d}.
1085 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1086 be omitted in which case the server will accept connections from any host.
1088 @item unix:@var{path}
1090 Connections will be allowed over UNIX domain sockets where @var{path} is the
1091 location of a unix socket to listen for connections on.
1095 VNC is initialized but not started. The monitor @code{change} command
1096 can be used to later start the VNC server.
1100 Following the @var{display} value there may be one or more @var{option} flags
1101 separated by commas. Valid options are
1107 Connect to a listening VNC client via a ``reverse'' connection. The
1108 client is specified by the @var{display}. For reverse network
1109 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1110 is a TCP port number, not a display number.
1114 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1115 By defintion the Websocket port is 5700+@var{display}. If @var{host} is
1116 specified connections will only be allowed from this host.
1117 As an alternative the Websocket port could be specified by using
1118 @code{websocket}=@var{port}.
1122 Require that password based authentication is used for client connections.
1124 The password must be set separately using the @code{set_password} command in
1125 the @ref{pcsys_monitor}. The syntax to change your password is:
1126 @code{set_password <protocol> <password>} where <protocol> could be either
1129 If you would like to change <protocol> password expiration, you should use
1130 @code{expire_password <protocol> <expiration-time>} where expiration time could
1131 be one of the following options: now, never, +seconds or UNIX time of
1132 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1133 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1136 You can also use keywords "now" or "never" for the expiration time to
1137 allow <protocol> password to expire immediately or never expire.
1141 Require that client use TLS when communicating with the VNC server. This
1142 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1143 attack. It is recommended that this option be combined with either the
1144 @option{x509} or @option{x509verify} options.
1146 @item x509=@var{/path/to/certificate/dir}
1148 Valid if @option{tls} is specified. Require that x509 credentials are used
1149 for negotiating the TLS session. The server will send its x509 certificate
1150 to the client. It is recommended that a password be set on the VNC server
1151 to provide authentication of the client when this is used. The path following
1152 this option specifies where the x509 certificates are to be loaded from.
1153 See the @ref{vnc_security} section for details on generating certificates.
1155 @item x509verify=@var{/path/to/certificate/dir}
1157 Valid if @option{tls} is specified. Require that x509 credentials are used
1158 for negotiating the TLS session. The server will send its x509 certificate
1159 to the client, and request that the client send its own x509 certificate.
1160 The server will validate the client's certificate against the CA certificate,
1161 and reject clients when validation fails. If the certificate authority is
1162 trusted, this is a sufficient authentication mechanism. You may still wish
1163 to set a password on the VNC server as a second authentication layer. The
1164 path following this option specifies where the x509 certificates are to
1165 be loaded from. See the @ref{vnc_security} section for details on generating
1170 Require that the client use SASL to authenticate with the VNC server.
1171 The exact choice of authentication method used is controlled from the
1172 system / user's SASL configuration file for the 'qemu' service. This
1173 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1174 unprivileged user, an environment variable SASL_CONF_PATH can be used
1175 to make it search alternate locations for the service config.
1176 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1177 it is recommended that SASL always be combined with the 'tls' and
1178 'x509' settings to enable use of SSL and server certificates. This
1179 ensures a data encryption preventing compromise of authentication
1180 credentials. See the @ref{vnc_security} section for details on using
1181 SASL authentication.
1185 Turn on access control lists for checking of the x509 client certificate
1186 and SASL party. For x509 certs, the ACL check is made against the
1187 certificate's distinguished name. This is something that looks like
1188 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1189 made against the username, which depending on the SASL plugin, may
1190 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1191 When the @option{acl} flag is set, the initial access list will be
1192 empty, with a @code{deny} policy. Thus no one will be allowed to
1193 use the VNC server until the ACLs have been loaded. This can be
1194 achieved using the @code{acl} monitor command.
1198 Enable lossy compression methods (gradient, JPEG, ...). If this
1199 option is set, VNC client may receive lossy framebuffer updates
1200 depending on its encoding settings. Enabling this option can save
1201 a lot of bandwidth at the expense of quality.
1205 Disable adaptive encodings. Adaptive encodings are enabled by default.
1206 An adaptive encoding will try to detect frequently updated screen regions,
1207 and send updates in these regions using a lossy encoding (like JPEG).
1208 This can be really helpful to save bandwidth when playing videos. Disabling
1209 adaptive encodings allows to restore the original static behavior of encodings
1212 @item share=[allow-exclusive|force-shared|ignore]
1214 Set display sharing policy. 'allow-exclusive' allows clients to ask
1215 for exclusive access. As suggested by the rfb spec this is
1216 implemented by dropping other connections. Connecting multiple
1217 clients in parallel requires all clients asking for a shared session
1218 (vncviewer: -shared switch). This is the default. 'force-shared'
1219 disables exclusive client access. Useful for shared desktop sessions,
1220 where you don't want someone forgetting specify -shared disconnect
1221 everybody else. 'ignore' completely ignores the shared flag and
1222 allows everybody connect unconditionally. Doesn't conform to the rfb
1223 spec but is traditional QEMU behavior.
1231 ARCHHEADING(, QEMU_ARCH_I386)
1233 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1238 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1239 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1244 Use it when installing Windows 2000 to avoid a disk full bug. After
1245 Windows 2000 is installed, you no longer need this option (this option
1246 slows down the IDE transfers).
1249 HXCOMM Deprecated by -rtc
1250 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1252 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1253 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1256 @item -no-fd-bootchk
1257 @findex -no-fd-bootchk
1258 Disable boot signature checking for floppy disks in Bochs BIOS. It may
1259 be needed to boot from old floppy disks.
1260 TODO: check reference to Bochs BIOS.
1263 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1264 "-no-acpi disable ACPI\n", QEMU_ARCH_I386)
1268 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1269 it if your guest OS complains about ACPI problems (PC target machine
1273 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1274 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1278 Disable HPET support.
1281 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1282 "-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"
1283 " ACPI table description\n", QEMU_ARCH_I386)
1285 @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}]...]
1287 Add ACPI table with specified header fields and context from specified files.
1288 For file=, take whole ACPI table from the specified files, including all
1289 ACPI headers (possible overridden by other options).
1290 For data=, only data
1291 portion of the table is used, all header information is specified in the
1295 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1296 "-smbios file=binary\n"
1297 " load SMBIOS entry from binary file\n"
1298 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1299 " specify SMBIOS type 0 fields\n"
1300 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1301 " [,uuid=uuid][,sku=str][,family=str]\n"
1302 " specify SMBIOS type 1 fields\n", QEMU_ARCH_I386)
1304 @item -smbios file=@var{binary}
1306 Load SMBIOS entry from binary file.
1308 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}]
1309 Specify SMBIOS type 0 fields
1311 @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}]
1312 Specify SMBIOS type 1 fields
1320 DEFHEADING(Network options:)
1325 HXCOMM Legacy slirp options (now moved to -net user):
1327 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1328 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1329 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1331 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1335 DEF("net", HAS_ARG, QEMU_OPTION_net,
1336 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1337 " create a new Network Interface Card and connect it to VLAN 'n'\n"
1339 "-net user[,vlan=n][,name=str][,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1340 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n"
1341 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1343 "[,smb=dir[,smbserver=addr]]\n"
1345 " connect the user mode network stack to VLAN 'n', configure its\n"
1346 " DHCP server and enabled optional services\n"
1349 "-net tap[,vlan=n][,name=str],ifname=name\n"
1350 " connect the host TAP network interface to VLAN 'n'\n"
1352 "-net tap[,vlan=n][,name=str][,fd=h][,ifname=name][,script=file][,downscript=dfile][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off][,vhostfd=h][,vhostforce=on|off]\n"
1353 " connect the host TAP network interface to VLAN 'n'\n"
1354 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1355 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1356 " to deconfigure it\n"
1357 " use '[down]script=no' to disable script execution\n"
1358 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1360 " use 'fd=h' to connect to an already opened TAP interface\n"
1361 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1362 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1363 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1364 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1365 " use vhost=on to enable experimental in kernel accelerator\n"
1366 " (only has effect for virtio guests which use MSIX)\n"
1367 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1368 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1369 "-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
1370 " connects a host TAP network interface to a host bridge device 'br'\n"
1371 " (default=" DEFAULT_BRIDGE_INTERFACE ") using the program 'helper'\n"
1372 " (default=" DEFAULT_BRIDGE_HELPER ")\n"
1374 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1375 " connect the vlan 'n' to another VLAN using a socket connection\n"
1376 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1377 " connect the vlan 'n' to multicast maddr and port\n"
1378 " use 'localaddr=addr' to specify the host address to send packets from\n"
1379 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1380 " connect the vlan 'n' to another VLAN using an UDP tunnel\n"
1382 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1383 " connect the vlan 'n' to port 'n' of a vde switch running\n"
1384 " on host and listening for incoming connections on 'socketpath'.\n"
1385 " Use group 'groupname' and mode 'octalmode' to change default\n"
1386 " ownership and permissions for communication port.\n"
1388 "-net dump[,vlan=n][,file=f][,len=n]\n"
1389 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
1390 "-net none use it alone to have zero network devices. If no -net option\n"
1391 " is provided, the default is '-net nic -net user'\n", QEMU_ARCH_ALL)
1392 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1402 "socket],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1404 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1406 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1407 = 0 is the default). The NIC is an e1000 by default on the PC
1408 target. Optionally, the MAC address can be changed to @var{mac}, the
1409 device address set to @var{addr} (PCI cards only),
1410 and a @var{name} can be assigned for use in monitor commands.
1411 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1412 that the card should have; this option currently only affects virtio cards; set
1413 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1414 NIC is created. QEMU can emulate several different models of network card.
1415 Valid values for @var{type} are
1416 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1417 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1418 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1419 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1420 for a list of available devices for your target.
1422 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1424 @item -net user[,@var{option}][,@var{option}][,...]
1425 Use the user mode network stack which requires no administrator
1426 privilege to run. Valid options are:
1430 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1433 @item name=@var{name}
1434 Assign symbolic name for use in monitor commands.
1436 @item net=@var{addr}[/@var{mask}]
1437 Set IP network address the guest will see. Optionally specify the netmask,
1438 either in the form a.b.c.d or as number of valid top-most bits. Default is
1441 @item host=@var{addr}
1442 Specify the guest-visible address of the host. Default is the 2nd IP in the
1443 guest network, i.e. x.x.x.2.
1445 @item restrict=on|off
1446 If this option is enabled, the guest will be isolated, i.e. it will not be
1447 able to contact the host and no guest IP packets will be routed over the host
1448 to the outside. This option does not affect any explicitly set forwarding rules.
1450 @item hostname=@var{name}
1451 Specifies the client hostname reported by the built-in DHCP server.
1453 @item dhcpstart=@var{addr}
1454 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1455 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1457 @item dns=@var{addr}
1458 Specify the guest-visible address of the virtual nameserver. The address must
1459 be different from the host address. Default is the 3rd IP in the guest network,
1462 @item dnssearch=@var{domain}
1463 Provides an entry for the domain-search list sent by the built-in
1464 DHCP server. More than one domain suffix can be transmitted by specifying
1465 this option multiple times. If supported, this will cause the guest to
1466 automatically try to append the given domain suffix(es) in case a domain name
1467 can not be resolved.
1471 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1474 @item tftp=@var{dir}
1475 When using the user mode network stack, activate a built-in TFTP
1476 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1477 The TFTP client on the guest must be configured in binary mode (use the command
1478 @code{bin} of the Unix TFTP client).
1480 @item bootfile=@var{file}
1481 When using the user mode network stack, broadcast @var{file} as the BOOTP
1482 filename. In conjunction with @option{tftp}, this can be used to network boot
1483 a guest from a local directory.
1485 Example (using pxelinux):
1487 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1490 @item smb=@var{dir}[,smbserver=@var{addr}]
1491 When using the user mode network stack, activate a built-in SMB
1492 server so that Windows OSes can access to the host files in @file{@var{dir}}
1493 transparently. The IP address of the SMB server can be set to @var{addr}. By
1494 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1496 In the guest Windows OS, the line:
1500 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1501 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1503 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1505 Note that a SAMBA server must be installed on the host OS.
1506 QEMU was tested successfully with smbd versions from Red Hat 9,
1507 Fedora Core 3 and OpenSUSE 11.x.
1509 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1510 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1511 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1512 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1513 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1514 be bound to a specific host interface. If no connection type is set, TCP is
1515 used. This option can be given multiple times.
1517 For example, to redirect host X11 connection from screen 1 to guest
1518 screen 0, use the following:
1522 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1523 # this host xterm should open in the guest X11 server
1527 To redirect telnet connections from host port 5555 to telnet port on
1528 the guest, use the following:
1532 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1533 telnet localhost 5555
1536 Then when you use on the host @code{telnet localhost 5555}, you
1537 connect to the guest telnet server.
1539 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1540 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1541 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1542 to the character device @var{dev} or to a program executed by @var{cmd:command}
1543 which gets spawned for each connection. This option can be given multiple times.
1545 You can either use a chardev directly and have that one used throughout QEMU's
1546 lifetime, like in the following example:
1549 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1550 # the guest accesses it
1551 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1554 Or you can execute a command on every TCP connection established by the guest,
1555 so that QEMU behaves similar to an inetd process for that virtual server:
1558 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
1559 # and connect the TCP stream to its stdin/stdout
1560 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1565 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1566 processed and applied to -net user. Mixing them with the new configuration
1567 syntax gives undefined results. Their use for new applications is discouraged
1568 as they will be removed from future versions.
1570 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1571 @item -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1572 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1574 Use the network script @var{file} to configure it and the network script
1575 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1576 automatically provides one. The default network configure script is
1577 @file{/etc/qemu-ifup} and the default network deconfigure script is
1578 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1579 to disable script execution.
1581 If running QEMU as an unprivileged user, use the network helper
1582 @var{helper} to configure the TAP interface. The default network
1583 helper executable is @file{/usr/local/libexec/qemu-bridge-helper}.
1585 @option{fd}=@var{h} can be used to specify the handle of an already
1586 opened host TAP interface.
1591 #launch a QEMU instance with the default network script
1592 qemu-system-i386 linux.img -net nic -net tap
1596 #launch a QEMU instance with two NICs, each one connected
1598 qemu-system-i386 linux.img \
1599 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1600 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1604 #launch a QEMU instance with the default network helper to
1605 #connect a TAP device to bridge br0
1606 qemu-system-i386 linux.img \
1607 -net nic -net tap,"helper=/usr/local/libexec/qemu-bridge-helper"
1610 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1611 @item -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1612 Connect a host TAP network interface to a host bridge device.
1614 Use the network helper @var{helper} to configure the TAP interface and
1615 attach it to the bridge. The default network helper executable is
1616 @file{/usr/local/libexec/qemu-bridge-helper} and the default bridge
1617 device is @file{br0}.
1622 #launch a QEMU instance with the default network helper to
1623 #connect a TAP device to bridge br0
1624 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1628 #launch a QEMU instance with the default network helper to
1629 #connect a TAP device to bridge qemubr0
1630 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1633 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1634 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1636 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1637 machine using a TCP socket connection. If @option{listen} is
1638 specified, QEMU waits for incoming connections on @var{port}
1639 (@var{host} is optional). @option{connect} is used to connect to
1640 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1641 specifies an already opened TCP socket.
1645 # launch a first QEMU instance
1646 qemu-system-i386 linux.img \
1647 -net nic,macaddr=52:54:00:12:34:56 \
1648 -net socket,listen=:1234
1649 # connect the VLAN 0 of this instance to the VLAN 0
1650 # of the first instance
1651 qemu-system-i386 linux.img \
1652 -net nic,macaddr=52:54:00:12:34:57 \
1653 -net socket,connect=127.0.0.1:1234
1656 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1657 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1659 Create a VLAN @var{n} shared with another QEMU virtual
1660 machines using a UDP multicast socket, effectively making a bus for
1661 every QEMU with same multicast address @var{maddr} and @var{port}.
1665 Several QEMU can be running on different hosts and share same bus (assuming
1666 correct multicast setup for these hosts).
1668 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1669 @url{http://user-mode-linux.sf.net}.
1671 Use @option{fd=h} to specify an already opened UDP multicast socket.
1676 # launch one QEMU instance
1677 qemu-system-i386 linux.img \
1678 -net nic,macaddr=52:54:00:12:34:56 \
1679 -net socket,mcast=230.0.0.1:1234
1680 # launch another QEMU instance on same "bus"
1681 qemu-system-i386 linux.img \
1682 -net nic,macaddr=52:54:00:12:34:57 \
1683 -net socket,mcast=230.0.0.1:1234
1684 # launch yet another QEMU instance on same "bus"
1685 qemu-system-i386 linux.img \
1686 -net nic,macaddr=52:54:00:12:34:58 \
1687 -net socket,mcast=230.0.0.1:1234
1690 Example (User Mode Linux compat.):
1692 # launch QEMU instance (note mcast address selected
1694 qemu-system-i386 linux.img \
1695 -net nic,macaddr=52:54:00:12:34:56 \
1696 -net socket,mcast=239.192.168.1:1102
1698 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1701 Example (send packets from host's 1.2.3.4):
1703 qemu-system-i386 linux.img \
1704 -net nic,macaddr=52:54:00:12:34:56 \
1705 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1708 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1709 @item -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1710 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
1711 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
1712 and MODE @var{octalmode} to change default ownership and permissions for
1713 communication port. This option is only available if QEMU has been compiled
1714 with vde support enabled.
1719 vde_switch -F -sock /tmp/myswitch
1720 # launch QEMU instance
1721 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
1724 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
1725 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
1726 At most @var{len} bytes (64k by default) per packet are stored. The file format is
1727 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
1730 Indicate that no network devices should be configured. It is used to
1731 override the default configuration (@option{-net nic -net user}) which
1732 is activated if no @option{-net} options are provided.
1740 DEFHEADING(Character device options:)
1743 The general form of a character device option is:
1747 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
1748 "-chardev null,id=id[,mux=on|off]\n"
1749 "-chardev socket,id=id[,host=host],port=host[,to=to][,ipv4][,ipv6][,nodelay]\n"
1750 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1751 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1752 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1753 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1754 "-chardev msmouse,id=id[,mux=on|off]\n"
1755 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1757 "-chardev ringbuf,id=id[,size=size]\n"
1758 "-chardev file,id=id,path=path[,mux=on|off]\n"
1759 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1761 "-chardev console,id=id[,mux=on|off]\n"
1762 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1764 "-chardev pty,id=id[,mux=on|off]\n"
1765 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1767 #ifdef CONFIG_BRLAPI
1768 "-chardev braille,id=id[,mux=on|off]\n"
1770 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
1771 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
1772 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1773 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1775 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
1776 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
1777 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1779 #if defined(CONFIG_SPICE)
1780 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1781 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
1787 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
1808 The specific backend will determine the applicable options.
1810 All devices must have an id, which can be any string up to 127 characters long.
1811 It is used to uniquely identify this device in other command line directives.
1813 A character device may be used in multiplexing mode by multiple front-ends.
1814 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
1815 between attached front-ends. Specify @option{mux=on} to enable this mode.
1817 Options to each backend are described below.
1819 @item -chardev null ,id=@var{id}
1820 A void device. This device will not emit any data, and will drop any data it
1821 receives. The null backend does not take any options.
1823 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet]
1825 Create a two-way stream socket, which can be either a TCP or a unix socket. A
1826 unix socket will be created if @option{path} is specified. Behaviour is
1827 undefined if TCP options are specified for a unix socket.
1829 @option{server} specifies that the socket shall be a listening socket.
1831 @option{nowait} specifies that QEMU should not block waiting for a client to
1832 connect to a listening socket.
1834 @option{telnet} specifies that traffic on the socket should interpret telnet
1837 TCP and unix socket options are given below:
1841 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
1843 @option{host} for a listening socket specifies the local address to be bound.
1844 For a connecting socket species the remote host to connect to. @option{host} is
1845 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
1847 @option{port} for a listening socket specifies the local port to be bound. For a
1848 connecting socket specifies the port on the remote host to connect to.
1849 @option{port} can be given as either a port number or a service name.
1850 @option{port} is required.
1852 @option{to} is only relevant to listening sockets. If it is specified, and
1853 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
1854 to and including @option{to} until it succeeds. @option{to} must be specified
1857 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1858 If neither is specified the socket may use either protocol.
1860 @option{nodelay} disables the Nagle algorithm.
1862 @item unix options: path=@var{path}
1864 @option{path} specifies the local path of the unix socket. @option{path} is
1869 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
1871 Sends all traffic from the guest to a remote host over UDP.
1873 @option{host} specifies the remote host to connect to. If not specified it
1874 defaults to @code{localhost}.
1876 @option{port} specifies the port on the remote host to connect to. @option{port}
1879 @option{localaddr} specifies the local address to bind to. If not specified it
1880 defaults to @code{0.0.0.0}.
1882 @option{localport} specifies the local port to bind to. If not specified any
1883 available local port will be used.
1885 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1886 If neither is specified the device may use either protocol.
1888 @item -chardev msmouse ,id=@var{id}
1890 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
1893 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
1895 Connect to a QEMU text console. @option{vc} may optionally be given a specific
1898 @option{width} and @option{height} specify the width and height respectively of
1899 the console, in pixels.
1901 @option{cols} and @option{rows} specify that the console be sized to fit a text
1902 console with the given dimensions.
1904 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
1906 Create a ring buffer with fixed size @option{size}.
1907 @var{size} must be a power of two, and defaults to @code{64K}).
1909 @item -chardev file ,id=@var{id} ,path=@var{path}
1911 Log all traffic received from the guest to a file.
1913 @option{path} specifies the path of the file to be opened. This file will be
1914 created if it does not already exist, and overwritten if it does. @option{path}
1917 @item -chardev pipe ,id=@var{id} ,path=@var{path}
1919 Create a two-way connection to the guest. The behaviour differs slightly between
1920 Windows hosts and other hosts:
1922 On Windows, a single duplex pipe will be created at
1923 @file{\\.pipe\@option{path}}.
1925 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
1926 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
1927 received by the guest. Data written by the guest can be read from
1928 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
1931 @option{path} forms part of the pipe path as described above. @option{path} is
1934 @item -chardev console ,id=@var{id}
1936 Send traffic from the guest to QEMU's standard output. @option{console} does not
1939 @option{console} is only available on Windows hosts.
1941 @item -chardev serial ,id=@var{id} ,path=@option{path}
1943 Send traffic from the guest to a serial device on the host.
1945 On Unix hosts serial will actually accept any tty device,
1946 not only serial lines.
1948 @option{path} specifies the name of the serial device to open.
1950 @item -chardev pty ,id=@var{id}
1952 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
1953 not take any options.
1955 @option{pty} is not available on Windows hosts.
1957 @item -chardev stdio ,id=@var{id} [,signal=on|off]
1958 Connect to standard input and standard output of the QEMU process.
1960 @option{signal} controls if signals are enabled on the terminal, that includes
1961 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
1962 default, use @option{signal=off} to disable it.
1964 @option{stdio} is not available on Windows hosts.
1966 @item -chardev braille ,id=@var{id}
1968 Connect to a local BrlAPI server. @option{braille} does not take any options.
1970 @item -chardev tty ,id=@var{id} ,path=@var{path}
1972 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
1973 DragonFlyBSD hosts. It is an alias for @option{serial}.
1975 @option{path} specifies the path to the tty. @option{path} is required.
1977 @item -chardev parallel ,id=@var{id} ,path=@var{path}
1978 @item -chardev parport ,id=@var{id} ,path=@var{path}
1980 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
1982 Connect to a local parallel port.
1984 @option{path} specifies the path to the parallel port device. @option{path} is
1987 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
1989 @option{spicevmc} is only available when spice support is built in.
1991 @option{debug} debug level for spicevmc
1993 @option{name} name of spice channel to connect to
1995 Connect to a spice virtual machine channel, such as vdiport.
1997 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
1999 @option{spiceport} is only available when spice support is built in.
2001 @option{debug} debug level for spicevmc
2003 @option{name} name of spice port to connect to
2005 Connect to a spice port, allowing a Spice client to handle the traffic
2006 identified by a name (preferably a fqdn).
2014 DEFHEADING(Device URL Syntax:)
2017 In addition to using normal file images for the emulated storage devices,
2018 QEMU can also use networked resources such as iSCSI devices. These are
2019 specified using a special URL syntax.
2023 iSCSI support allows QEMU to access iSCSI resources directly and use as
2024 images for the guest storage. Both disk and cdrom images are supported.
2026 Syntax for specifying iSCSI LUNs is
2027 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2029 By default qemu will use the iSCSI initiator-name
2030 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2031 line or a configuration file.
2034 Example (without authentication):
2036 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2037 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2038 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2041 Example (CHAP username/password via URL):
2043 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2046 Example (CHAP username/password via environment variables):
2048 LIBISCSI_CHAP_USERNAME="user" \
2049 LIBISCSI_CHAP_PASSWORD="password" \
2050 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2053 iSCSI support is an optional feature of QEMU and only available when
2054 compiled and linked against libiscsi.
2056 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
2057 "-iscsi [user=user][,password=password]\n"
2058 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2059 " [,initiator-name=iqn]\n"
2060 " iSCSI session parameters\n", QEMU_ARCH_ALL)
2063 iSCSI parameters such as username and password can also be specified via
2064 a configuration file. See qemu-doc for more information and examples.
2067 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2068 as Unix Domain Sockets.
2070 Syntax for specifying a NBD device using TCP
2071 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2073 Syntax for specifying a NBD device using Unix Domain Sockets
2074 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2079 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2082 Example for Unix Domain Sockets
2084 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2088 Sheepdog is a distributed storage system for QEMU.
2089 QEMU supports using either local sheepdog devices or remote networked
2092 Syntax for specifying a sheepdog device
2094 ``sheepdog:<vdiname>''
2096 ``sheepdog:<vdiname>:<snapid>''
2098 ``sheepdog:<vdiname>:<tag>''
2100 ``sheepdog:<host>:<port>:<vdiname>''
2102 ``sheepdog:<host>:<port>:<vdiname>:<snapid>''
2104 ``sheepdog:<host>:<port>:<vdiname>:<tag>''
2109 qemu-system-i386 --drive file=sheepdog:192.0.2.1:30000:MyVirtualMachine
2112 See also @url{http://http://www.osrg.net/sheepdog/}.
2115 GlusterFS is an user space distributed file system.
2116 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2117 TCP, Unix Domain Sockets and RDMA transport protocols.
2119 Syntax for specifying a VM disk image on GlusterFS volume is
2121 gluster[+transport]://[server[:port]]/volname/image[?socket=...]
2127 qemu-system-x86_84 --drive file=gluster://192.0.2.1/testvol/a.img
2130 See also @url{http://www.gluster.org}.
2137 DEFHEADING(Bluetooth(R) options:)
2142 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2143 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2144 "-bt hci,host[:id]\n" \
2145 " use host's HCI with the given name\n" \
2146 "-bt hci[,vlan=n]\n" \
2147 " emulate a standard HCI in virtual scatternet 'n'\n" \
2148 "-bt vhci[,vlan=n]\n" \
2149 " add host computer to virtual scatternet 'n' using VHCI\n" \
2150 "-bt device:dev[,vlan=n]\n" \
2151 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2156 Defines the function of the corresponding Bluetooth HCI. -bt options
2157 are matched with the HCIs present in the chosen machine type. For
2158 example when emulating a machine with only one HCI built into it, only
2159 the first @code{-bt hci[...]} option is valid and defines the HCI's
2160 logic. The Transport Layer is decided by the machine type. Currently
2161 the machines @code{n800} and @code{n810} have one HCI and all other
2165 The following three types are recognized:
2169 (default) The corresponding Bluetooth HCI assumes no internal logic
2170 and will not respond to any HCI commands or emit events.
2172 @item -bt hci,host[:@var{id}]
2173 (@code{bluez} only) The corresponding HCI passes commands / events
2174 to / from the physical HCI identified by the name @var{id} (default:
2175 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2176 capable systems like Linux.
2178 @item -bt hci[,vlan=@var{n}]
2179 Add a virtual, standard HCI that will participate in the Bluetooth
2180 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2181 VLANs, devices inside a bluetooth network @var{n} can only communicate
2182 with other devices in the same network (scatternet).
2185 @item -bt vhci[,vlan=@var{n}]
2186 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2187 to the host bluetooth stack instead of to the emulated target. This
2188 allows the host and target machines to participate in a common scatternet
2189 and communicate. Requires the Linux @code{vhci} driver installed. Can
2190 be used as following:
2193 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2196 @item -bt device:@var{dev}[,vlan=@var{n}]
2197 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2198 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2203 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2212 DEFHEADING(Linux/Multiboot boot specific:)
2215 When using these options, you can use a given Linux or Multiboot
2216 kernel without installing it in the disk image. It can be useful
2217 for easier testing of various kernels.
2222 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2223 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2225 @item -kernel @var{bzImage}
2227 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2228 or in multiboot format.
2231 DEF("append", HAS_ARG, QEMU_OPTION_append, \
2232 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2234 @item -append @var{cmdline}
2236 Use @var{cmdline} as kernel command line
2239 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
2240 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
2242 @item -initrd @var{file}
2244 Use @var{file} as initial ram disk.
2246 @item -initrd "@var{file1} arg=foo,@var{file2}"
2248 This syntax is only available with multiboot.
2250 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2254 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
2255 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
2257 @item -dtb @var{file}
2259 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2268 DEFHEADING(Debug/Expert options:)
2273 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
2274 "-serial dev redirect the serial port to char device 'dev'\n",
2277 @item -serial @var{dev}
2279 Redirect the virtual serial port to host character device
2280 @var{dev}. The default device is @code{vc} in graphical mode and
2281 @code{stdio} in non graphical mode.
2283 This option can be used several times to simulate up to 4 serial
2286 Use @code{-serial none} to disable all serial ports.
2288 Available character devices are:
2290 @item vc[:@var{W}x@var{H}]
2291 Virtual console. Optionally, a width and height can be given in pixel with
2295 It is also possible to specify width or height in characters:
2300 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
2302 No device is allocated.
2306 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2307 parameters are set according to the emulated ones.
2308 @item /dev/parport@var{N}
2309 [Linux only, parallel port only] Use host parallel port
2310 @var{N}. Currently SPP and EPP parallel port features can be used.
2311 @item file:@var{filename}
2312 Write output to @var{filename}. No character can be read.
2314 [Unix only] standard input/output
2315 @item pipe:@var{filename}
2316 name pipe @var{filename}
2318 [Windows only] Use host serial port @var{n}
2319 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
2320 This implements UDP Net Console.
2321 When @var{remote_host} or @var{src_ip} are not specified
2322 they default to @code{0.0.0.0}.
2323 When not using a specified @var{src_port} a random port is automatically chosen.
2325 If you just want a simple readonly console you can use @code{netcat} or
2326 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
2327 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
2328 will appear in the netconsole session.
2330 If you plan to send characters back via netconsole or you want to stop
2331 and start QEMU a lot of times, you should have QEMU use the same
2332 source port each time by using something like @code{-serial
2333 udp::4555@@:4556} to QEMU. Another approach is to use a patched
2334 version of netcat which can listen to a TCP port and send and receive
2335 characters via udp. If you have a patched version of netcat which
2336 activates telnet remote echo and single char transfer, then you can
2337 use the following options to step up a netcat redirector to allow
2338 telnet on port 5555 to access the QEMU port.
2341 -serial udp::4555@@:4556
2342 @item netcat options:
2343 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
2344 @item telnet options:
2348 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay]
2349 The TCP Net Console has two modes of operation. It can send the serial
2350 I/O to a location or wait for a connection from a location. By default
2351 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
2352 the @var{server} option QEMU will wait for a client socket application
2353 to connect to the port before continuing, unless the @code{nowait}
2354 option was specified. The @code{nodelay} option disables the Nagle buffering
2355 algorithm. If @var{host} is omitted, 0.0.0.0 is assumed. Only
2356 one TCP connection at a time is accepted. You can use @code{telnet} to
2357 connect to the corresponding character device.
2359 @item Example to send tcp console to 192.168.0.2 port 4444
2360 -serial tcp:192.168.0.2:4444
2361 @item Example to listen and wait on port 4444 for connection
2362 -serial tcp::4444,server
2363 @item Example to not wait and listen on ip 192.168.0.100 port 4444
2364 -serial tcp:192.168.0.100:4444,server,nowait
2367 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
2368 The telnet protocol is used instead of raw tcp sockets. The options
2369 work the same as if you had specified @code{-serial tcp}. The
2370 difference is that the port acts like a telnet server or client using
2371 telnet option negotiation. This will also allow you to send the
2372 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
2373 sequence. Typically in unix telnet you do it with Control-] and then
2374 type "send break" followed by pressing the enter key.
2376 @item unix:@var{path}[,server][,nowait]
2377 A unix domain socket is used instead of a tcp socket. The option works the
2378 same as if you had specified @code{-serial tcp} except the unix domain socket
2379 @var{path} is used for connections.
2381 @item mon:@var{dev_string}
2382 This is a special option to allow the monitor to be multiplexed onto
2383 another serial port. The monitor is accessed with key sequence of
2384 @key{Control-a} and then pressing @key{c}. See monitor access
2385 @ref{pcsys_keys} in the -nographic section for more keys.
2386 @var{dev_string} should be any one of the serial devices specified
2387 above. An example to multiplex the monitor onto a telnet server
2388 listening on port 4444 would be:
2390 @item -serial mon:telnet::4444,server,nowait
2394 Braille device. This will use BrlAPI to display the braille output on a real
2398 Three button serial mouse. Configure the guest to use Microsoft protocol.
2402 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
2403 "-parallel dev redirect the parallel port to char device 'dev'\n",
2406 @item -parallel @var{dev}
2408 Redirect the virtual parallel port to host device @var{dev} (same
2409 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
2410 be used to use hardware devices connected on the corresponding host
2413 This option can be used several times to simulate up to 3 parallel
2416 Use @code{-parallel none} to disable all parallel ports.
2419 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
2420 "-monitor dev redirect the monitor to char device 'dev'\n",
2423 @item -monitor @var{dev}
2425 Redirect the monitor to host device @var{dev} (same devices as the
2427 The default device is @code{vc} in graphical mode and @code{stdio} in
2430 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
2431 "-qmp dev like -monitor but opens in 'control' mode\n",
2434 @item -qmp @var{dev}
2436 Like -monitor but opens in 'control' mode.
2439 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
2440 "-mon chardev=[name][,mode=readline|control][,default]\n", QEMU_ARCH_ALL)
2442 @item -mon chardev=[name][,mode=readline|control][,default]
2444 Setup monitor on chardev @var{name}.
2447 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
2448 "-debugcon dev redirect the debug console to char device 'dev'\n",
2451 @item -debugcon @var{dev}
2453 Redirect the debug console to host device @var{dev} (same devices as the
2454 serial port). The debug console is an I/O port which is typically port
2455 0xe9; writing to that I/O port sends output to this device.
2456 The default device is @code{vc} in graphical mode and @code{stdio} in
2460 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
2461 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
2463 @item -pidfile @var{file}
2465 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
2469 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
2470 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
2474 Run the emulation in single step mode.
2477 DEF("S", 0, QEMU_OPTION_S, \
2478 "-S freeze CPU at startup (use 'c' to start execution)\n",
2483 Do not start CPU at startup (you must type 'c' in the monitor).
2486 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
2487 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
2489 @item -gdb @var{dev}
2491 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
2492 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
2493 stdio are reasonable use case. The latter is allowing to start QEMU from
2494 within gdb and establish the connection via a pipe:
2496 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
2500 DEF("s", 0, QEMU_OPTION_s, \
2501 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
2506 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
2507 (@pxref{gdb_usage}).
2510 DEF("d", HAS_ARG, QEMU_OPTION_d, \
2511 "-d item1,... output log to /tmp/qemu.log (use '-d help' for a list of log items)\n",
2516 Output log in /tmp/qemu.log
2519 DEF("D", HAS_ARG, QEMU_OPTION_D, \
2520 "-D logfile output log to logfile (instead of the default /tmp/qemu.log)\n",
2523 @item -D @var{logfile}
2525 Output log in @var{logfile} instead of /tmp/qemu.log
2528 DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
2529 "-hdachs c,h,s[,t]\n" \
2530 " force hard disk 0 physical geometry and the optional BIOS\n" \
2531 " translation (t=none or lba) (usually QEMU can guess them)\n",
2534 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
2536 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
2537 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
2538 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
2539 all those parameters. This option is useful for old MS-DOS disk
2543 DEF("L", HAS_ARG, QEMU_OPTION_L, \
2544 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2549 Set the directory for the BIOS, VGA BIOS and keymaps.
2552 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
2553 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
2555 @item -bios @var{file}
2557 Set the filename for the BIOS.
2560 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
2561 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
2565 Enable KVM full virtualization support. This option is only available
2566 if KVM support is enabled when compiling.
2569 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
2570 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
2571 DEF("xen-create", 0, QEMU_OPTION_xen_create,
2572 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2573 " warning: should not be used when xend is in use\n",
2575 DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
2576 "-xen-attach attach to existing xen domain\n"
2577 " xend will use this when starting QEMU\n",
2580 @item -xen-domid @var{id}
2582 Specify xen guest domain @var{id} (XEN only).
2585 Create domain using xen hypercalls, bypassing xend.
2586 Warning: should not be used when xend is in use (XEN only).
2589 Attach to existing xen domain.
2590 xend will use this when starting QEMU (XEN only).
2593 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
2594 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
2598 Exit instead of rebooting.
2601 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
2602 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
2605 @findex -no-shutdown
2606 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
2607 This allows for instance switching to monitor to commit changes to the
2611 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2612 "-loadvm [tag|id]\n" \
2613 " start right away with a saved state (loadvm in monitor)\n",
2616 @item -loadvm @var{file}
2618 Start right away with a saved state (@code{loadvm} in monitor)
2622 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2623 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2628 Daemonize the QEMU process after initialization. QEMU will not detach from
2629 standard IO until it is ready to receive connections on any of its devices.
2630 This option is a useful way for external programs to launch QEMU without having
2631 to cope with initialization race conditions.
2634 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2635 "-option-rom rom load a file, rom, into the option ROM space\n",
2638 @item -option-rom @var{file}
2640 Load the contents of @var{file} as an option ROM.
2641 This option is useful to load things like EtherBoot.
2644 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2645 "-clock force the use of the given methods for timer alarm.\n" \
2646 " To see what timers are available use '-clock help'\n",
2649 @item -clock @var{method}
2651 Force the use of the given methods for timer alarm. To see what timers
2652 are available use @code{-clock help}.
2655 HXCOMM Options deprecated by -rtc
2656 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2657 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2659 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2660 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
2661 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
2666 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
2668 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
2669 UTC or local time, respectively. @code{localtime} is required for correct date in
2670 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
2671 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
2673 By default the RTC is driven by the host system time. This allows to use the
2674 RTC as accurate reference clock inside the guest, specifically if the host
2675 time is smoothly following an accurate external reference clock, e.g. via NTP.
2676 If you want to isolate the guest time from the host, you can set @option{clock}
2677 to @code{rt} instead. To even prevent it from progressing during suspension,
2678 you can set it to @code{vm}.
2680 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
2681 specifically with Windows' ACPI HAL. This option will try to figure out how
2682 many timer interrupts were not processed by the Windows guest and will
2686 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
2687 "-icount [N|auto]\n" \
2688 " enable virtual instruction counter with 2^N clock ticks per\n" \
2689 " instruction\n", QEMU_ARCH_ALL)
2691 @item -icount [@var{N}|auto]
2693 Enable virtual instruction counter. The virtual cpu will execute one
2694 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
2695 then the virtual cpu speed will be automatically adjusted to keep virtual
2696 time within a few seconds of real time.
2698 Note that while this option can give deterministic behavior, it does not
2699 provide cycle accurate emulation. Modern CPUs contain superscalar out of
2700 order cores with complex cache hierarchies. The number of instructions
2701 executed often has little or no correlation with actual performance.
2704 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
2705 "-watchdog i6300esb|ib700\n" \
2706 " enable virtual hardware watchdog [default=none]\n",
2709 @item -watchdog @var{model}
2711 Create a virtual hardware watchdog device. Once enabled (by a guest
2712 action), the watchdog must be periodically polled by an agent inside
2713 the guest or else the guest will be restarted.
2715 The @var{model} is the model of hardware watchdog to emulate. Choices
2716 for model are: @code{ib700} (iBASE 700) which is a very simple ISA
2717 watchdog with a single timer, or @code{i6300esb} (Intel 6300ESB I/O
2718 controller hub) which is a much more featureful PCI-based dual-timer
2719 watchdog. Choose a model for which your guest has drivers.
2721 Use @code{-watchdog help} to list available hardware models. Only one
2722 watchdog can be enabled for a guest.
2725 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
2726 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
2727 " action when watchdog fires [default=reset]\n",
2730 @item -watchdog-action @var{action}
2731 @findex -watchdog-action
2733 The @var{action} controls what QEMU will do when the watchdog timer
2736 @code{reset} (forcefully reset the guest).
2737 Other possible actions are:
2738 @code{shutdown} (attempt to gracefully shutdown the guest),
2739 @code{poweroff} (forcefully poweroff the guest),
2740 @code{pause} (pause the guest),
2741 @code{debug} (print a debug message and continue), or
2742 @code{none} (do nothing).
2744 Note that the @code{shutdown} action requires that the guest responds
2745 to ACPI signals, which it may not be able to do in the sort of
2746 situations where the watchdog would have expired, and thus
2747 @code{-watchdog-action shutdown} is not recommended for production use.
2752 @item -watchdog i6300esb -watchdog-action pause
2753 @item -watchdog ib700
2757 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
2758 "-echr chr set terminal escape character instead of ctrl-a\n",
2762 @item -echr @var{numeric_ascii_value}
2764 Change the escape character used for switching to the monitor when using
2765 monitor and serial sharing. The default is @code{0x01} when using the
2766 @code{-nographic} option. @code{0x01} is equal to pressing
2767 @code{Control-a}. You can select a different character from the ascii
2768 control keys where 1 through 26 map to Control-a through Control-z. For
2769 instance you could use the either of the following to change the escape
2770 character to Control-t.
2777 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
2778 "-virtioconsole c\n" \
2779 " set virtio console\n", QEMU_ARCH_ALL)
2781 @item -virtioconsole @var{c}
2782 @findex -virtioconsole
2785 This option is maintained for backward compatibility.
2787 Please use @code{-device virtconsole} for the new way of invocation.
2790 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
2791 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
2794 @findex -show-cursor
2798 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
2799 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
2801 @item -tb-size @var{n}
2806 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
2807 "-incoming p prepare for incoming migration, listen on port p\n",
2810 @item -incoming @var{port}
2812 Prepare for incoming migration, listen on @var{port}.
2815 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
2816 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
2820 Don't create default devices. Normally, QEMU sets the default devices like serial
2821 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
2822 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
2827 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
2828 "-chroot dir chroot to dir just before starting the VM\n",
2832 @item -chroot @var{dir}
2834 Immediately before starting guest execution, chroot to the specified
2835 directory. Especially useful in combination with -runas.
2839 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
2840 "-runas user change to user id user just before starting the VM\n",
2844 @item -runas @var{user}
2846 Immediately before starting guest execution, drop root privileges, switching
2847 to the specified user.
2850 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
2851 "-prom-env variable=value\n"
2852 " set OpenBIOS nvram variables\n",
2853 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
2855 @item -prom-env @var{variable}=@var{value}
2857 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
2859 DEF("semihosting", 0, QEMU_OPTION_semihosting,
2860 "-semihosting semihosting mode\n", QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA)
2863 @findex -semihosting
2864 Semihosting mode (ARM, M68K, Xtensa only).
2866 DEF("old-param", 0, QEMU_OPTION_old_param,
2867 "-old-param old param mode\n", QEMU_ARCH_ARM)
2870 @findex -old-param (ARM)
2871 Old param mode (ARM only).
2874 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
2875 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n",
2878 @item -sandbox @var{arg}
2880 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
2881 disable it. The default is 'off'.
2884 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
2885 "-readconfig <file>\n", QEMU_ARCH_ALL)
2887 @item -readconfig @var{file}
2889 Read device configuration from @var{file}. This approach is useful when you want to spawn
2890 QEMU process with many command line options but you don't want to exceed the command line
2893 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
2894 "-writeconfig <file>\n"
2895 " read/write config file\n", QEMU_ARCH_ALL)
2897 @item -writeconfig @var{file}
2898 @findex -writeconfig
2899 Write device configuration to @var{file}. The @var{file} can be either filename to save
2900 command line and device configuration into file or dash @code{-}) character to print the
2901 output to stdout. This can be later used as input file for @code{-readconfig} option.
2903 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
2905 " do not load default config files at startup\n",
2909 @findex -nodefconfig
2910 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
2911 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
2913 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
2915 " do not load user-provided config files at startup\n",
2918 @item -no-user-config
2919 @findex -no-user-config
2920 The @code{-no-user-config} option makes QEMU not load any of the user-provided
2921 config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config
2922 files from @var{datadir}.
2924 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
2925 "-trace [events=<file>][,file=<file>]\n"
2926 " specify tracing options\n",
2929 HXCOMM This line is not accurate, as some sub-options are backend-specific but
2930 HXCOMM HX does not support conditional compilation of text.
2931 @item -trace [events=@var{file}][,file=@var{file}]
2934 Specify tracing options.
2937 @item events=@var{file}
2938 Immediately enable events listed in @var{file}.
2939 The file must contain one event name (as listed in the @var{trace-events} file)
2941 This option is only available if QEMU has been compiled with
2942 either @var{simple} or @var{stderr} tracing backend.
2943 @item file=@var{file}
2944 Log output traces to @var{file}.
2946 This option is only available if QEMU has been compiled with
2947 the @var{simple} tracing backend.
2952 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
2953 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
2956 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
2957 "-enable-fips enable FIPS 140-2 compliance\n",
2962 @findex -enable-fips
2963 Enable FIPS 140-2 compliance mode.
2966 HXCOMM Deprecated by -machine accel=tcg property
2967 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
2969 HXCOMM Deprecated by kvm-pit driver properties
2970 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
2973 HXCOMM Deprecated (ignored)
2974 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
2976 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
2977 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
2979 HXCOMM Deprecated (ignored)
2980 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
2982 DEF("object", HAS_ARG, QEMU_OPTION_object,
2983 "-object TYPENAME[,PROP1=VALUE1,...]\n"
2984 " create an new object of type TYPENAME setting properties\n"
2985 " in the order they are specified. Note that the 'id'\n"
2986 " property must be set. These objects are placed in the\n"
2987 " '/objects' path.\n",
2990 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
2992 Create an new object of type @var{typename} setting properties
2993 in the order they are specified. Note that the 'id'
2994 property must be set. These objects are placed in the
2998 HXCOMM This is the last statement. Insert new options before this line!