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
547 DEF("usb", 0, QEMU_OPTION_usb,
548 "-usb enable the USB driver (will be the default soon)\n",
553 Enable the USB driver (will be the default soon)
556 DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
557 "-usbdevice name add the host or guest USB device 'name'\n",
561 @item -usbdevice @var{devname}
563 Add the USB device @var{devname}. @xref{usb_devices}.
568 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
571 Pointer device that uses absolute coordinates (like a touchscreen). This
572 means QEMU is able to report the mouse position without having to grab the
573 mouse. Also overrides the PS/2 mouse emulation when activated.
575 @item disk:[format=@var{format}]:@var{file}
576 Mass storage device based on file. The optional @var{format} argument
577 will be used rather than detecting the format. Can be used to specifiy
578 @code{format=raw} to avoid interpreting an untrusted format header.
580 @item host:@var{bus}.@var{addr}
581 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
583 @item host:@var{vendor_id}:@var{product_id}
584 Pass through the host device identified by @var{vendor_id}:@var{product_id}
587 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
588 Serial converter to host character device @var{dev}, see @code{-serial} for the
592 Braille device. This will use BrlAPI to display the braille output on a real
595 @item net:@var{options}
596 Network adapter that supports CDC ethernet and RNDIS protocols.
601 DEF("device", HAS_ARG, QEMU_OPTION_device,
602 "-device driver[,prop[=value][,...]]\n"
603 " add device (based on driver)\n"
604 " prop=value,... sets driver properties\n"
605 " use '-device help' to print all possible drivers\n"
606 " use '-device driver,help' to print all possible properties\n",
609 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
611 Add device @var{driver}. @var{prop}=@var{value} sets driver
612 properties. Valid properties depend on the driver. To get help on
613 possible drivers and properties, use @code{-device help} and
614 @code{-device @var{driver},help}.
622 DEFHEADING(File system options:)
627 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
628 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
629 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
634 @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}]
636 Define a new file system device. Valid options are:
639 This option specifies the fs driver backend to use.
640 Currently "local", "handle" and "proxy" file system drivers are supported.
642 Specifies identifier for this device
643 @item path=@var{path}
644 Specifies the export path for the file system device. Files under
645 this path will be available to the 9p client on the guest.
646 @item security_model=@var{security_model}
647 Specifies the security model to be used for this export path.
648 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
649 In "passthrough" security model, files are stored using the same
650 credentials as they are created on the guest. This requires QEMU
651 to run as root. In "mapped-xattr" security model, some of the file
652 attributes like uid, gid, mode bits and link target are stored as
653 file attributes. For "mapped-file" these attributes are stored in the
654 hidden .virtfs_metadata directory. Directories exported by this security model cannot
655 interact with other unix tools. "none" security model is same as
656 passthrough except the sever won't report failures if it fails to
657 set file attributes like ownership. Security model is mandatory
658 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
659 security model as a parameter.
660 @item writeout=@var{writeout}
661 This is an optional argument. The only supported value is "immediate".
662 This means that host page cache will be used to read and write data but
663 write notification will be sent to the guest only when the data has been
664 reported as written by the storage subsystem.
666 Enables exporting 9p share as a readonly mount for guests. By default
667 read-write access is given.
668 @item socket=@var{socket}
669 Enables proxy filesystem driver to use passed socket file for communicating
670 with virtfs-proxy-helper
671 @item sock_fd=@var{sock_fd}
672 Enables proxy filesystem driver to use passed socket descriptor for
673 communicating with virtfs-proxy-helper. Usually a helper like libvirt
674 will create socketpair and pass one of the fds as sock_fd
677 -fsdev option is used along with -device driver "virtio-9p-pci".
678 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
679 Options for virtio-9p-pci driver are:
682 Specifies the id value specified along with -fsdev option
683 @item mount_tag=@var{mount_tag}
684 Specifies the tag name to be used by the guest to mount this export point
694 DEFHEADING(Virtual File system pass-through options:)
699 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
700 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
701 " [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd]\n",
706 @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}]
709 The general form of a Virtual File system pass-through options are:
712 This option specifies the fs driver backend to use.
713 Currently "local", "handle" and "proxy" file system drivers are supported.
715 Specifies identifier for this device
716 @item path=@var{path}
717 Specifies the export path for the file system device. Files under
718 this path will be available to the 9p client on the guest.
719 @item security_model=@var{security_model}
720 Specifies the security model to be used for this export path.
721 Supported security models are "passthrough", "mapped-xattr", "mapped-file" and "none".
722 In "passthrough" security model, files are stored using the same
723 credentials as they are created on the guest. This requires QEMU
724 to run as root. In "mapped-xattr" security model, some of the file
725 attributes like uid, gid, mode bits and link target are stored as
726 file attributes. For "mapped-file" these attributes are stored in the
727 hidden .virtfs_metadata directory. Directories exported by this security model cannot
728 interact with other unix tools. "none" security model is same as
729 passthrough except the sever won't report failures if it fails to
730 set file attributes like ownership. Security model is mandatory only
731 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
732 model as a parameter.
733 @item writeout=@var{writeout}
734 This is an optional argument. The only supported value is "immediate".
735 This means that host page cache will be used to read and write data but
736 write notification will be sent to the guest only when the data has been
737 reported as written by the storage subsystem.
739 Enables exporting 9p share as a readonly mount for guests. By default
740 read-write access is given.
741 @item socket=@var{socket}
742 Enables proxy filesystem driver to use passed socket file for
743 communicating with virtfs-proxy-helper. Usually a helper like libvirt
744 will create socketpair and pass one of the fds as sock_fd
746 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
747 descriptor for interfacing with virtfs-proxy-helper
751 DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
752 "-virtfs_synth Create synthetic file system image\n",
756 @findex -virtfs_synth
757 Create synthetic file system image
762 DEF("name", HAS_ARG, QEMU_OPTION_name,
763 "-name string1[,process=string2]\n"
764 " set the name of the guest\n"
765 " string1 sets the window title and string2 the process name (on Linux)\n",
768 @item -name @var{name}
770 Sets the @var{name} of the guest.
771 This name will be displayed in the SDL window caption.
772 The @var{name} will also be used for the VNC server.
773 Also optionally set the top visible process name in Linux.
776 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
777 "-uuid %08x-%04x-%04x-%04x-%012x\n"
778 " specify machine UUID\n", QEMU_ARCH_ALL)
780 @item -uuid @var{uuid}
790 DEFHEADING(Display options:)
795 DEF("display", HAS_ARG, QEMU_OPTION_display,
796 "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
797 " [,window_close=on|off]|curses|none|\n"
798 " vnc=<display>[,<optargs>]\n"
799 " select display type\n", QEMU_ARCH_ALL)
801 @item -display @var{type}
803 Select type of display to use. This option is a replacement for the
804 old style -sdl/-curses/... options. Valid values for @var{type} are
807 Display video output via SDL (usually in a separate graphics
808 window; see the SDL documentation for other possibilities).
810 Display video output via curses. For graphics device models which
811 support a text mode, QEMU can display this output using a
812 curses/ncurses interface. Nothing is displayed when the graphics
813 device is in graphical mode or if the graphics device does not support
814 a text mode. Generally only the VGA device models support text mode.
816 Do not display video output. The guest will still see an emulated
817 graphics card, but its output will not be displayed to the QEMU
818 user. This option differs from the -nographic option in that it
819 only affects what is done with video output; -nographic also changes
820 the destination of the serial and parallel port data.
822 Start a VNC server on display <arg>
826 DEF("nographic", 0, QEMU_OPTION_nographic,
827 "-nographic disable graphical output and redirect serial I/Os to console\n",
832 Normally, QEMU uses SDL to display the VGA output. With this option,
833 you can totally disable graphical output so that QEMU is a simple
834 command line application. The emulated serial port is redirected on
835 the console. Therefore, you can still use QEMU to debug a Linux kernel
836 with a serial console.
839 DEF("curses", 0, QEMU_OPTION_curses,
840 "-curses use a curses/ncurses interface instead of SDL\n",
845 Normally, QEMU uses SDL to display the VGA output. With this option,
846 QEMU can display the VGA output when in text mode using a
847 curses/ncurses interface. Nothing is displayed in graphical mode.
850 DEF("no-frame", 0, QEMU_OPTION_no_frame,
851 "-no-frame open SDL window without a frame and window decorations\n",
856 Do not use decorations for SDL windows and start them using the whole
857 available screen space. This makes the using QEMU in a dedicated desktop
858 workspace more convenient.
861 DEF("alt-grab", 0, QEMU_OPTION_alt_grab,
862 "-alt-grab use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt)\n",
867 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
868 affects the special keys (for fullscreen, monitor-mode switching, etc).
871 DEF("ctrl-grab", 0, QEMU_OPTION_ctrl_grab,
872 "-ctrl-grab use Right-Ctrl to grab mouse (instead of Ctrl-Alt)\n",
877 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
878 affects the special keys (for fullscreen, monitor-mode switching, etc).
881 DEF("no-quit", 0, QEMU_OPTION_no_quit,
882 "-no-quit disable SDL window close capability\n", QEMU_ARCH_ALL)
886 Disable SDL window close capability.
889 DEF("sdl", 0, QEMU_OPTION_sdl,
890 "-sdl enable SDL\n", QEMU_ARCH_ALL)
897 DEF("spice", HAS_ARG, QEMU_OPTION_spice,
898 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
899 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
900 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
901 " [,x509-dh-key-file=<file>][,addr=addr][,ipv4|ipv6]\n"
902 " [,tls-ciphers=<list>]\n"
903 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
904 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
905 " [,sasl][,password=<secret>][,disable-ticketing]\n"
906 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
907 " [,jpeg-wan-compression=[auto|never|always]]\n"
908 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
909 " [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
910 " [,agent-mouse=[on|off]][,playback-compression=[on|off]]\n"
911 " [,seamless-migration=[on|off]]\n"
913 " at least one of {port, tls-port} is mandatory\n",
916 @item -spice @var{option}[,@var{option}[,...]]
918 Enable the spice remote desktop protocol. Valid options are
923 Set the TCP port spice is listening on for plaintext channels.
926 Set the IP address spice is listening on. Default is any address.
930 Force using the specified IP version.
932 @item password=<secret>
933 Set the password you need to authenticate.
936 Require that the client use SASL to authenticate with the spice.
937 The exact choice of authentication method used is controlled from the
938 system / user's SASL configuration file for the 'qemu' service. This
939 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
940 unprivileged user, an environment variable SASL_CONF_PATH can be used
941 to make it search alternate locations for the service config.
942 While some SASL auth methods can also provide data encryption (eg GSSAPI),
943 it is recommended that SASL always be combined with the 'tls' and
944 'x509' settings to enable use of SSL and server certificates. This
945 ensures a data encryption preventing compromise of authentication
948 @item disable-ticketing
949 Allow client connects without authentication.
951 @item disable-copy-paste
952 Disable copy paste between the client and the guest.
955 Set the TCP port spice is listening on for encrypted channels.
958 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
960 @item x509-key-file=<file>
961 @item x509-key-password=<file>
962 @item x509-cert-file=<file>
963 @item x509-cacert-file=<file>
964 @item x509-dh-key-file=<file>
965 The x509 file names can also be configured individually.
967 @item tls-ciphers=<list>
968 Specify which ciphers to use.
970 @item tls-channel=[main|display|cursor|inputs|record|playback]
971 @item plaintext-channel=[main|display|cursor|inputs|record|playback]
972 Force specific channel to be used with or without TLS encryption. The
973 options can be specified multiple times to configure multiple
974 channels. The special name "default" can be used to set the default
975 mode. For channels which are not explicitly forced into one mode the
976 spice client is allowed to pick tls/plaintext as he pleases.
978 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
979 Configure image compression (lossless).
982 @item jpeg-wan-compression=[auto|never|always]
983 @item zlib-glz-wan-compression=[auto|never|always]
984 Configure wan image compression (lossy for slow links).
987 @item streaming-video=[off|all|filter]
988 Configure video stream detection. Default is filter.
990 @item agent-mouse=[on|off]
991 Enable/disable passing mouse events via vdagent. Default is on.
993 @item playback-compression=[on|off]
994 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
996 @item seamless-migration=[on|off]
997 Enable/disable spice seamless migration. Default is off.
1002 DEF("portrait", 0, QEMU_OPTION_portrait,
1003 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
1008 Rotate graphical output 90 deg left (only PXA LCD).
1011 DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
1012 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
1015 @item -rotate @var{deg}
1017 Rotate graphical output some deg left (only PXA LCD).
1020 DEF("vga", HAS_ARG, QEMU_OPTION_vga,
1021 "-vga [std|cirrus|vmware|qxl|xenfb|none]\n"
1022 " select video card type\n", QEMU_ARCH_ALL)
1024 @item -vga @var{type}
1026 Select type of VGA card to emulate. Valid values for @var{type} are
1029 Cirrus Logic GD5446 Video card. All Windows versions starting from
1030 Windows 95 should recognize and use this graphic card. For optimal
1031 performances, use 16 bit color depth in the guest and the host OS.
1032 (This one is the default)
1034 Standard VGA card with Bochs VBE extensions. If your guest OS
1035 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1036 to use high resolution modes (>= 1280x1024x16) then you should use
1039 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1040 recent XFree86/XOrg server or Windows guest with a driver for this
1043 QXL paravirtual graphic card. It is VGA compatible (including VESA
1044 2.0 VBE support). Works best with qxl guest drivers installed though.
1045 Recommended choice when using the spice protocol.
1051 DEF("full-screen", 0, QEMU_OPTION_full_screen,
1052 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
1055 @findex -full-screen
1056 Start in full screen.
1059 DEF("g", 1, QEMU_OPTION_g ,
1060 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
1061 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1063 @item -g @var{width}x@var{height}[x@var{depth}]
1065 Set the initial graphical resolution and depth (PPC, SPARC only).
1068 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
1069 "-vnc display start a VNC server on display\n", QEMU_ARCH_ALL)
1071 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1073 Normally, QEMU uses SDL to display the VGA output. With this option,
1074 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1075 display over the VNC session. It is very useful to enable the usb
1076 tablet device when using this option (option @option{-usbdevice
1077 tablet}). When using the VNC display, you must use the @option{-k}
1078 parameter to set the keyboard layout if you are not using en-us. Valid
1079 syntax for the @var{display} is
1083 @item @var{host}:@var{d}
1085 TCP connections will only be allowed from @var{host} on display @var{d}.
1086 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1087 be omitted in which case the server will accept connections from any host.
1089 @item unix:@var{path}
1091 Connections will be allowed over UNIX domain sockets where @var{path} is the
1092 location of a unix socket to listen for connections on.
1096 VNC is initialized but not started. The monitor @code{change} command
1097 can be used to later start the VNC server.
1101 Following the @var{display} value there may be one or more @var{option} flags
1102 separated by commas. Valid options are
1108 Connect to a listening VNC client via a ``reverse'' connection. The
1109 client is specified by the @var{display}. For reverse network
1110 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1111 is a TCP port number, not a display number.
1115 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1116 By defintion the Websocket port is 5700+@var{display}. If @var{host} is
1117 specified connections will only be allowed from this host.
1118 As an alternative the Websocket port could be specified by using
1119 @code{websocket}=@var{port}.
1123 Require that password based authentication is used for client connections.
1125 The password must be set separately using the @code{set_password} command in
1126 the @ref{pcsys_monitor}. The syntax to change your password is:
1127 @code{set_password <protocol> <password>} where <protocol> could be either
1130 If you would like to change <protocol> password expiration, you should use
1131 @code{expire_password <protocol> <expiration-time>} where expiration time could
1132 be one of the following options: now, never, +seconds or UNIX time of
1133 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1134 to make password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
1137 You can also use keywords "now" or "never" for the expiration time to
1138 allow <protocol> password to expire immediately or never expire.
1142 Require that client use TLS when communicating with the VNC server. This
1143 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1144 attack. It is recommended that this option be combined with either the
1145 @option{x509} or @option{x509verify} options.
1147 @item x509=@var{/path/to/certificate/dir}
1149 Valid if @option{tls} is specified. Require that x509 credentials are used
1150 for negotiating the TLS session. The server will send its x509 certificate
1151 to the client. It is recommended that a password be set on the VNC server
1152 to provide authentication of the client when this is used. The path following
1153 this option specifies where the x509 certificates are to be loaded from.
1154 See the @ref{vnc_security} section for details on generating certificates.
1156 @item x509verify=@var{/path/to/certificate/dir}
1158 Valid if @option{tls} is specified. Require that x509 credentials are used
1159 for negotiating the TLS session. The server will send its x509 certificate
1160 to the client, and request that the client send its own x509 certificate.
1161 The server will validate the client's certificate against the CA certificate,
1162 and reject clients when validation fails. If the certificate authority is
1163 trusted, this is a sufficient authentication mechanism. You may still wish
1164 to set a password on the VNC server as a second authentication layer. The
1165 path following this option specifies where the x509 certificates are to
1166 be loaded from. See the @ref{vnc_security} section for details on generating
1171 Require that the client use SASL to authenticate with the VNC server.
1172 The exact choice of authentication method used is controlled from the
1173 system / user's SASL configuration file for the 'qemu' service. This
1174 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1175 unprivileged user, an environment variable SASL_CONF_PATH can be used
1176 to make it search alternate locations for the service config.
1177 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1178 it is recommended that SASL always be combined with the 'tls' and
1179 'x509' settings to enable use of SSL and server certificates. This
1180 ensures a data encryption preventing compromise of authentication
1181 credentials. See the @ref{vnc_security} section for details on using
1182 SASL authentication.
1186 Turn on access control lists for checking of the x509 client certificate
1187 and SASL party. For x509 certs, the ACL check is made against the
1188 certificate's distinguished name. This is something that looks like
1189 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1190 made against the username, which depending on the SASL plugin, may
1191 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1192 When the @option{acl} flag is set, the initial access list will be
1193 empty, with a @code{deny} policy. Thus no one will be allowed to
1194 use the VNC server until the ACLs have been loaded. This can be
1195 achieved using the @code{acl} monitor command.
1199 Enable lossy compression methods (gradient, JPEG, ...). If this
1200 option is set, VNC client may receive lossy framebuffer updates
1201 depending on its encoding settings. Enabling this option can save
1202 a lot of bandwidth at the expense of quality.
1206 Disable adaptive encodings. Adaptive encodings are enabled by default.
1207 An adaptive encoding will try to detect frequently updated screen regions,
1208 and send updates in these regions using a lossy encoding (like JPEG).
1209 This can be really helpful to save bandwidth when playing videos. Disabling
1210 adaptive encodings allows to restore the original static behavior of encodings
1213 @item share=[allow-exclusive|force-shared|ignore]
1215 Set display sharing policy. 'allow-exclusive' allows clients to ask
1216 for exclusive access. As suggested by the rfb spec this is
1217 implemented by dropping other connections. Connecting multiple
1218 clients in parallel requires all clients asking for a shared session
1219 (vncviewer: -shared switch). This is the default. 'force-shared'
1220 disables exclusive client access. Useful for shared desktop sessions,
1221 where you don't want someone forgetting specify -shared disconnect
1222 everybody else. 'ignore' completely ignores the shared flag and
1223 allows everybody connect unconditionally. Doesn't conform to the rfb
1224 spec but is traditional QEMU behavior.
1232 ARCHHEADING(, QEMU_ARCH_I386)
1234 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1239 DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
1240 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
1245 Use it when installing Windows 2000 to avoid a disk full bug. After
1246 Windows 2000 is installed, you no longer need this option (this option
1247 slows down the IDE transfers).
1250 HXCOMM Deprecated by -rtc
1251 DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "", QEMU_ARCH_I386)
1253 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
1254 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
1257 @item -no-fd-bootchk
1258 @findex -no-fd-bootchk
1259 Disable boot signature checking for floppy disks in Bochs BIOS. It may
1260 be needed to boot from old floppy disks.
1261 TODO: check reference to Bochs BIOS.
1264 DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
1265 "-no-acpi disable ACPI\n", QEMU_ARCH_I386)
1269 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1270 it if your guest OS complains about ACPI problems (PC target machine
1274 DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
1275 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
1279 Disable HPET support.
1282 DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
1283 "-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"
1284 " ACPI table description\n", QEMU_ARCH_I386)
1286 @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}]...]
1288 Add ACPI table with specified header fields and context from specified files.
1289 For file=, take whole ACPI table from the specified files, including all
1290 ACPI headers (possible overridden by other options).
1291 For data=, only data
1292 portion of the table is used, all header information is specified in the
1296 DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
1297 "-smbios file=binary\n"
1298 " load SMBIOS entry from binary file\n"
1299 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
1300 " specify SMBIOS type 0 fields\n"
1301 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
1302 " [,uuid=uuid][,sku=str][,family=str]\n"
1303 " specify SMBIOS type 1 fields\n", QEMU_ARCH_I386)
1305 @item -smbios file=@var{binary}
1307 Load SMBIOS entry from binary file.
1309 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}]
1310 Specify SMBIOS type 0 fields
1312 @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}]
1313 Specify SMBIOS type 1 fields
1321 DEFHEADING(Network options:)
1326 HXCOMM Legacy slirp options (now moved to -net user):
1328 DEF("tftp", HAS_ARG, QEMU_OPTION_tftp, "", QEMU_ARCH_ALL)
1329 DEF("bootp", HAS_ARG, QEMU_OPTION_bootp, "", QEMU_ARCH_ALL)
1330 DEF("redir", HAS_ARG, QEMU_OPTION_redir, "", QEMU_ARCH_ALL)
1332 DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
1336 DEF("net", HAS_ARG, QEMU_OPTION_net,
1337 "-net nic[,vlan=n][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
1338 " create a new Network Interface Card and connect it to VLAN 'n'\n"
1340 "-net user[,vlan=n][,name=str][,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
1341 " [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n"
1342 " [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
1344 "[,smb=dir[,smbserver=addr]]\n"
1346 " connect the user mode network stack to VLAN 'n', configure its\n"
1347 " DHCP server and enabled optional services\n"
1350 "-net tap[,vlan=n][,name=str],ifname=name\n"
1351 " connect the host TAP network interface to VLAN 'n'\n"
1353 "-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"
1354 " connect the host TAP network interface to VLAN 'n'\n"
1355 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
1356 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
1357 " to deconfigure it\n"
1358 " use '[down]script=no' to disable script execution\n"
1359 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
1361 " use 'fd=h' to connect to an already opened TAP interface\n"
1362 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
1363 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
1364 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
1365 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
1366 " use vhost=on to enable experimental in kernel accelerator\n"
1367 " (only has effect for virtio guests which use MSIX)\n"
1368 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
1369 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
1370 "-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
1371 " connects a host TAP network interface to a host bridge device 'br'\n"
1372 " (default=" DEFAULT_BRIDGE_INTERFACE ") using the program 'helper'\n"
1373 " (default=" DEFAULT_BRIDGE_HELPER ")\n"
1375 "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
1376 " connect the vlan 'n' to another VLAN using a socket connection\n"
1377 "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
1378 " connect the vlan 'n' to multicast maddr and port\n"
1379 " use 'localaddr=addr' to specify the host address to send packets from\n"
1380 "-net socket[,vlan=n][,name=str][,fd=h][,udp=host:port][,localaddr=host:port]\n"
1381 " connect the vlan 'n' to another VLAN using an UDP tunnel\n"
1383 "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
1384 " connect the vlan 'n' to port 'n' of a vde switch running\n"
1385 " on host and listening for incoming connections on 'socketpath'.\n"
1386 " Use group 'groupname' and mode 'octalmode' to change default\n"
1387 " ownership and permissions for communication port.\n"
1389 "-net dump[,vlan=n][,file=f][,len=n]\n"
1390 " dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
1391 "-net none use it alone to have zero network devices. If no -net option\n"
1392 " is provided, the default is '-net nic -net user'\n", QEMU_ARCH_ALL)
1393 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
1403 "socket],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
1405 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1407 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1408 = 0 is the default). The NIC is an e1000 by default on the PC
1409 target. Optionally, the MAC address can be changed to @var{mac}, the
1410 device address set to @var{addr} (PCI cards only),
1411 and a @var{name} can be assigned for use in monitor commands.
1412 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1413 that the card should have; this option currently only affects virtio cards; set
1414 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1415 NIC is created. QEMU can emulate several different models of network card.
1416 Valid values for @var{type} are
1417 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1418 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1419 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1420 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1421 for a list of available devices for your target.
1423 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1425 @item -net user[,@var{option}][,@var{option}][,...]
1426 Use the user mode network stack which requires no administrator
1427 privilege to run. Valid options are:
1431 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1434 @item name=@var{name}
1435 Assign symbolic name for use in monitor commands.
1437 @item net=@var{addr}[/@var{mask}]
1438 Set IP network address the guest will see. Optionally specify the netmask,
1439 either in the form a.b.c.d or as number of valid top-most bits. Default is
1442 @item host=@var{addr}
1443 Specify the guest-visible address of the host. Default is the 2nd IP in the
1444 guest network, i.e. x.x.x.2.
1446 @item restrict=on|off
1447 If this option is enabled, the guest will be isolated, i.e. it will not be
1448 able to contact the host and no guest IP packets will be routed over the host
1449 to the outside. This option does not affect any explicitly set forwarding rules.
1451 @item hostname=@var{name}
1452 Specifies the client hostname reported by the built-in DHCP server.
1454 @item dhcpstart=@var{addr}
1455 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1456 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1458 @item dns=@var{addr}
1459 Specify the guest-visible address of the virtual nameserver. The address must
1460 be different from the host address. Default is the 3rd IP in the guest network,
1463 @item dnssearch=@var{domain}
1464 Provides an entry for the domain-search list sent by the built-in
1465 DHCP server. More than one domain suffix can be transmitted by specifying
1466 this option multiple times. If supported, this will cause the guest to
1467 automatically try to append the given domain suffix(es) in case a domain name
1468 can not be resolved.
1472 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1475 @item tftp=@var{dir}
1476 When using the user mode network stack, activate a built-in TFTP
1477 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1478 The TFTP client on the guest must be configured in binary mode (use the command
1479 @code{bin} of the Unix TFTP client).
1481 @item bootfile=@var{file}
1482 When using the user mode network stack, broadcast @var{file} as the BOOTP
1483 filename. In conjunction with @option{tftp}, this can be used to network boot
1484 a guest from a local directory.
1486 Example (using pxelinux):
1488 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1491 @item smb=@var{dir}[,smbserver=@var{addr}]
1492 When using the user mode network stack, activate a built-in SMB
1493 server so that Windows OSes can access to the host files in @file{@var{dir}}
1494 transparently. The IP address of the SMB server can be set to @var{addr}. By
1495 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1497 In the guest Windows OS, the line:
1501 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1502 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1504 Then @file{@var{dir}} can be accessed in @file{\\smbserver\qemu}.
1506 Note that a SAMBA server must be installed on the host OS.
1507 QEMU was tested successfully with smbd versions from Red Hat 9,
1508 Fedora Core 3 and OpenSUSE 11.x.
1510 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1511 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1512 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1513 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1514 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1515 be bound to a specific host interface. If no connection type is set, TCP is
1516 used. This option can be given multiple times.
1518 For example, to redirect host X11 connection from screen 1 to guest
1519 screen 0, use the following:
1523 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1524 # this host xterm should open in the guest X11 server
1528 To redirect telnet connections from host port 5555 to telnet port on
1529 the guest, use the following:
1533 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1534 telnet localhost 5555
1537 Then when you use on the host @code{telnet localhost 5555}, you
1538 connect to the guest telnet server.
1540 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1541 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1542 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1543 to the character device @var{dev} or to a program executed by @var{cmd:command}
1544 which gets spawned for each connection. This option can be given multiple times.
1546 You can either use a chardev directly and have that one used throughout QEMU's
1547 lifetime, like in the following example:
1550 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1551 # the guest accesses it
1552 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1555 Or you can execute a command on every TCP connection established by the guest,
1556 so that QEMU behaves similar to an inetd process for that virtual server:
1559 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
1560 # and connect the TCP stream to its stdin/stdout
1561 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1566 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1567 processed and applied to -net user. Mixing them with the new configuration
1568 syntax gives undefined results. Their use for new applications is discouraged
1569 as they will be removed from future versions.
1571 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1572 @item -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1573 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1575 Use the network script @var{file} to configure it and the network script
1576 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1577 automatically provides one. The default network configure script is
1578 @file{/etc/qemu-ifup} and the default network deconfigure script is
1579 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1580 to disable script execution.
1582 If running QEMU as an unprivileged user, use the network helper
1583 @var{helper} to configure the TAP interface. The default network
1584 helper executable is @file{/usr/local/libexec/qemu-bridge-helper}.
1586 @option{fd}=@var{h} can be used to specify the handle of an already
1587 opened host TAP interface.
1592 #launch a QEMU instance with the default network script
1593 qemu-system-i386 linux.img -net nic -net tap
1597 #launch a QEMU instance with two NICs, each one connected
1599 qemu-system-i386 linux.img \
1600 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1601 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1605 #launch a QEMU instance with the default network helper to
1606 #connect a TAP device to bridge br0
1607 qemu-system-i386 linux.img \
1608 -net nic -net tap,"helper=/usr/local/libexec/qemu-bridge-helper"
1611 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1612 @item -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1613 Connect a host TAP network interface to a host bridge device.
1615 Use the network helper @var{helper} to configure the TAP interface and
1616 attach it to the bridge. The default network helper executable is
1617 @file{/usr/local/libexec/qemu-bridge-helper} and the default bridge
1618 device is @file{br0}.
1623 #launch a QEMU instance with the default network helper to
1624 #connect a TAP device to bridge br0
1625 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1629 #launch a QEMU instance with the default network helper to
1630 #connect a TAP device to bridge qemubr0
1631 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1634 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1635 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1637 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1638 machine using a TCP socket connection. If @option{listen} is
1639 specified, QEMU waits for incoming connections on @var{port}
1640 (@var{host} is optional). @option{connect} is used to connect to
1641 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1642 specifies an already opened TCP socket.
1646 # launch a first QEMU instance
1647 qemu-system-i386 linux.img \
1648 -net nic,macaddr=52:54:00:12:34:56 \
1649 -net socket,listen=:1234
1650 # connect the VLAN 0 of this instance to the VLAN 0
1651 # of the first instance
1652 qemu-system-i386 linux.img \
1653 -net nic,macaddr=52:54:00:12:34:57 \
1654 -net socket,connect=127.0.0.1:1234
1657 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1658 @item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1660 Create a VLAN @var{n} shared with another QEMU virtual
1661 machines using a UDP multicast socket, effectively making a bus for
1662 every QEMU with same multicast address @var{maddr} and @var{port}.
1666 Several QEMU can be running on different hosts and share same bus (assuming
1667 correct multicast setup for these hosts).
1669 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1670 @url{http://user-mode-linux.sf.net}.
1672 Use @option{fd=h} to specify an already opened UDP multicast socket.
1677 # launch one QEMU instance
1678 qemu-system-i386 linux.img \
1679 -net nic,macaddr=52:54:00:12:34:56 \
1680 -net socket,mcast=230.0.0.1:1234
1681 # launch another QEMU instance on same "bus"
1682 qemu-system-i386 linux.img \
1683 -net nic,macaddr=52:54:00:12:34:57 \
1684 -net socket,mcast=230.0.0.1:1234
1685 # launch yet another QEMU instance on same "bus"
1686 qemu-system-i386 linux.img \
1687 -net nic,macaddr=52:54:00:12:34:58 \
1688 -net socket,mcast=230.0.0.1:1234
1691 Example (User Mode Linux compat.):
1693 # launch QEMU instance (note mcast address selected
1695 qemu-system-i386 linux.img \
1696 -net nic,macaddr=52:54:00:12:34:56 \
1697 -net socket,mcast=239.192.168.1:1102
1699 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1702 Example (send packets from host's 1.2.3.4):
1704 qemu-system-i386 linux.img \
1705 -net nic,macaddr=52:54:00:12:34:56 \
1706 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1709 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1710 @item -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
1711 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
1712 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
1713 and MODE @var{octalmode} to change default ownership and permissions for
1714 communication port. This option is only available if QEMU has been compiled
1715 with vde support enabled.
1720 vde_switch -F -sock /tmp/myswitch
1721 # launch QEMU instance
1722 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
1725 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
1726 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
1727 At most @var{len} bytes (64k by default) per packet are stored. The file format is
1728 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
1731 Indicate that no network devices should be configured. It is used to
1732 override the default configuration (@option{-net nic -net user}) which
1733 is activated if no @option{-net} options are provided.
1741 DEFHEADING(Character device options:)
1744 The general form of a character device option is:
1748 DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
1749 "-chardev null,id=id[,mux=on|off]\n"
1750 "-chardev socket,id=id[,host=host],port=host[,to=to][,ipv4][,ipv6][,nodelay]\n"
1751 " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n"
1752 "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n"
1753 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
1754 " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
1755 "-chardev msmouse,id=id[,mux=on|off]\n"
1756 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
1758 "-chardev ringbuf,id=id[,size=size]\n"
1759 "-chardev file,id=id,path=path[,mux=on|off]\n"
1760 "-chardev pipe,id=id,path=path[,mux=on|off]\n"
1762 "-chardev console,id=id[,mux=on|off]\n"
1763 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1765 "-chardev pty,id=id[,mux=on|off]\n"
1766 "-chardev stdio,id=id[,mux=on|off][,signal=on|off]\n"
1768 #ifdef CONFIG_BRLAPI
1769 "-chardev braille,id=id[,mux=on|off]\n"
1771 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
1772 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
1773 "-chardev serial,id=id,path=path[,mux=on|off]\n"
1774 "-chardev tty,id=id,path=path[,mux=on|off]\n"
1776 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
1777 "-chardev parallel,id=id,path=path[,mux=on|off]\n"
1778 "-chardev parport,id=id,path=path[,mux=on|off]\n"
1780 #if defined(CONFIG_SPICE)
1781 "-chardev spicevmc,id=id,name=name[,debug=debug]\n"
1782 "-chardev spiceport,id=id,name=name[,debug=debug]\n"
1788 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
1809 The specific backend will determine the applicable options.
1811 All devices must have an id, which can be any string up to 127 characters long.
1812 It is used to uniquely identify this device in other command line directives.
1814 A character device may be used in multiplexing mode by multiple front-ends.
1815 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
1816 between attached front-ends. Specify @option{mux=on} to enable this mode.
1818 Options to each backend are described below.
1820 @item -chardev null ,id=@var{id}
1821 A void device. This device will not emit any data, and will drop any data it
1822 receives. The null backend does not take any options.
1824 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet]
1826 Create a two-way stream socket, which can be either a TCP or a unix socket. A
1827 unix socket will be created if @option{path} is specified. Behaviour is
1828 undefined if TCP options are specified for a unix socket.
1830 @option{server} specifies that the socket shall be a listening socket.
1832 @option{nowait} specifies that QEMU should not block waiting for a client to
1833 connect to a listening socket.
1835 @option{telnet} specifies that traffic on the socket should interpret telnet
1838 TCP and unix socket options are given below:
1842 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
1844 @option{host} for a listening socket specifies the local address to be bound.
1845 For a connecting socket species the remote host to connect to. @option{host} is
1846 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
1848 @option{port} for a listening socket specifies the local port to be bound. For a
1849 connecting socket specifies the port on the remote host to connect to.
1850 @option{port} can be given as either a port number or a service name.
1851 @option{port} is required.
1853 @option{to} is only relevant to listening sockets. If it is specified, and
1854 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
1855 to and including @option{to} until it succeeds. @option{to} must be specified
1858 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1859 If neither is specified the socket may use either protocol.
1861 @option{nodelay} disables the Nagle algorithm.
1863 @item unix options: path=@var{path}
1865 @option{path} specifies the local path of the unix socket. @option{path} is
1870 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
1872 Sends all traffic from the guest to a remote host over UDP.
1874 @option{host} specifies the remote host to connect to. If not specified it
1875 defaults to @code{localhost}.
1877 @option{port} specifies the port on the remote host to connect to. @option{port}
1880 @option{localaddr} specifies the local address to bind to. If not specified it
1881 defaults to @code{0.0.0.0}.
1883 @option{localport} specifies the local port to bind to. If not specified any
1884 available local port will be used.
1886 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
1887 If neither is specified the device may use either protocol.
1889 @item -chardev msmouse ,id=@var{id}
1891 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
1894 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
1896 Connect to a QEMU text console. @option{vc} may optionally be given a specific
1899 @option{width} and @option{height} specify the width and height respectively of
1900 the console, in pixels.
1902 @option{cols} and @option{rows} specify that the console be sized to fit a text
1903 console with the given dimensions.
1905 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
1907 Create a ring buffer with fixed size @option{size}.
1908 @var{size} must be a power of two, and defaults to @code{64K}).
1910 @item -chardev file ,id=@var{id} ,path=@var{path}
1912 Log all traffic received from the guest to a file.
1914 @option{path} specifies the path of the file to be opened. This file will be
1915 created if it does not already exist, and overwritten if it does. @option{path}
1918 @item -chardev pipe ,id=@var{id} ,path=@var{path}
1920 Create a two-way connection to the guest. The behaviour differs slightly between
1921 Windows hosts and other hosts:
1923 On Windows, a single duplex pipe will be created at
1924 @file{\\.pipe\@option{path}}.
1926 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
1927 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
1928 received by the guest. Data written by the guest can be read from
1929 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
1932 @option{path} forms part of the pipe path as described above. @option{path} is
1935 @item -chardev console ,id=@var{id}
1937 Send traffic from the guest to QEMU's standard output. @option{console} does not
1940 @option{console} is only available on Windows hosts.
1942 @item -chardev serial ,id=@var{id} ,path=@option{path}
1944 Send traffic from the guest to a serial device on the host.
1946 On Unix hosts serial will actually accept any tty device,
1947 not only serial lines.
1949 @option{path} specifies the name of the serial device to open.
1951 @item -chardev pty ,id=@var{id}
1953 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
1954 not take any options.
1956 @option{pty} is not available on Windows hosts.
1958 @item -chardev stdio ,id=@var{id} [,signal=on|off]
1959 Connect to standard input and standard output of the QEMU process.
1961 @option{signal} controls if signals are enabled on the terminal, that includes
1962 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
1963 default, use @option{signal=off} to disable it.
1965 @option{stdio} is not available on Windows hosts.
1967 @item -chardev braille ,id=@var{id}
1969 Connect to a local BrlAPI server. @option{braille} does not take any options.
1971 @item -chardev tty ,id=@var{id} ,path=@var{path}
1973 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
1974 DragonFlyBSD hosts. It is an alias for @option{serial}.
1976 @option{path} specifies the path to the tty. @option{path} is required.
1978 @item -chardev parallel ,id=@var{id} ,path=@var{path}
1979 @item -chardev parport ,id=@var{id} ,path=@var{path}
1981 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
1983 Connect to a local parallel port.
1985 @option{path} specifies the path to the parallel port device. @option{path} is
1988 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
1990 @option{spicevmc} is only available when spice support is built in.
1992 @option{debug} debug level for spicevmc
1994 @option{name} name of spice channel to connect to
1996 Connect to a spice virtual machine channel, such as vdiport.
1998 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2000 @option{spiceport} is only available when spice support is built in.
2002 @option{debug} debug level for spicevmc
2004 @option{name} name of spice port to connect to
2006 Connect to a spice port, allowing a Spice client to handle the traffic
2007 identified by a name (preferably a fqdn).
2015 DEFHEADING(Device URL Syntax:)
2018 In addition to using normal file images for the emulated storage devices,
2019 QEMU can also use networked resources such as iSCSI devices. These are
2020 specified using a special URL syntax.
2024 iSCSI support allows QEMU to access iSCSI resources directly and use as
2025 images for the guest storage. Both disk and cdrom images are supported.
2027 Syntax for specifying iSCSI LUNs is
2028 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2030 By default qemu will use the iSCSI initiator-name
2031 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2032 line or a configuration file.
2035 Example (without authentication):
2037 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2038 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2039 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2042 Example (CHAP username/password via URL):
2044 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2047 Example (CHAP username/password via environment variables):
2049 LIBISCSI_CHAP_USERNAME="user" \
2050 LIBISCSI_CHAP_PASSWORD="password" \
2051 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2054 iSCSI support is an optional feature of QEMU and only available when
2055 compiled and linked against libiscsi.
2057 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
2058 "-iscsi [user=user][,password=password]\n"
2059 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
2060 " [,initiator-name=iqn]\n"
2061 " iSCSI session parameters\n", QEMU_ARCH_ALL)
2064 iSCSI parameters such as username and password can also be specified via
2065 a configuration file. See qemu-doc for more information and examples.
2068 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2069 as Unix Domain Sockets.
2071 Syntax for specifying a NBD device using TCP
2072 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2074 Syntax for specifying a NBD device using Unix Domain Sockets
2075 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2080 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2083 Example for Unix Domain Sockets
2085 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2089 Sheepdog is a distributed storage system for QEMU.
2090 QEMU supports using either local sheepdog devices or remote networked
2093 Syntax for specifying a sheepdog device
2095 ``sheepdog:<vdiname>''
2097 ``sheepdog:<vdiname>:<snapid>''
2099 ``sheepdog:<vdiname>:<tag>''
2101 ``sheepdog:<host>:<port>:<vdiname>''
2103 ``sheepdog:<host>:<port>:<vdiname>:<snapid>''
2105 ``sheepdog:<host>:<port>:<vdiname>:<tag>''
2110 qemu-system-i386 --drive file=sheepdog:192.0.2.1:30000:MyVirtualMachine
2113 See also @url{http://http://www.osrg.net/sheepdog/}.
2116 GlusterFS is an user space distributed file system.
2117 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2118 TCP, Unix Domain Sockets and RDMA transport protocols.
2120 Syntax for specifying a VM disk image on GlusterFS volume is
2122 gluster[+transport]://[server[:port]]/volname/image[?socket=...]
2128 qemu-system-x86_84 --drive file=gluster://192.0.2.1/testvol/a.img
2131 See also @url{http://www.gluster.org}.
2138 DEFHEADING(Bluetooth(R) options:)
2143 DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
2144 "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
2145 "-bt hci,host[:id]\n" \
2146 " use host's HCI with the given name\n" \
2147 "-bt hci[,vlan=n]\n" \
2148 " emulate a standard HCI in virtual scatternet 'n'\n" \
2149 "-bt vhci[,vlan=n]\n" \
2150 " add host computer to virtual scatternet 'n' using VHCI\n" \
2151 "-bt device:dev[,vlan=n]\n" \
2152 " emulate a bluetooth device 'dev' in scatternet 'n'\n",
2157 Defines the function of the corresponding Bluetooth HCI. -bt options
2158 are matched with the HCIs present in the chosen machine type. For
2159 example when emulating a machine with only one HCI built into it, only
2160 the first @code{-bt hci[...]} option is valid and defines the HCI's
2161 logic. The Transport Layer is decided by the machine type. Currently
2162 the machines @code{n800} and @code{n810} have one HCI and all other
2166 The following three types are recognized:
2170 (default) The corresponding Bluetooth HCI assumes no internal logic
2171 and will not respond to any HCI commands or emit events.
2173 @item -bt hci,host[:@var{id}]
2174 (@code{bluez} only) The corresponding HCI passes commands / events
2175 to / from the physical HCI identified by the name @var{id} (default:
2176 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2177 capable systems like Linux.
2179 @item -bt hci[,vlan=@var{n}]
2180 Add a virtual, standard HCI that will participate in the Bluetooth
2181 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2182 VLANs, devices inside a bluetooth network @var{n} can only communicate
2183 with other devices in the same network (scatternet).
2186 @item -bt vhci[,vlan=@var{n}]
2187 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2188 to the host bluetooth stack instead of to the emulated target. This
2189 allows the host and target machines to participate in a common scatternet
2190 and communicate. Requires the Linux @code{vhci} driver installed. Can
2191 be used as following:
2194 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2197 @item -bt device:@var{dev}[,vlan=@var{n}]
2198 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2199 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2204 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2213 DEFHEADING(Linux/Multiboot boot specific:)
2216 When using these options, you can use a given Linux or Multiboot
2217 kernel without installing it in the disk image. It can be useful
2218 for easier testing of various kernels.
2223 DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
2224 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
2226 @item -kernel @var{bzImage}
2228 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2229 or in multiboot format.
2232 DEF("append", HAS_ARG, QEMU_OPTION_append, \
2233 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
2235 @item -append @var{cmdline}
2237 Use @var{cmdline} as kernel command line
2240 DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
2241 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
2243 @item -initrd @var{file}
2245 Use @var{file} as initial ram disk.
2247 @item -initrd "@var{file1} arg=foo,@var{file2}"
2249 This syntax is only available with multiboot.
2251 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2255 DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
2256 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
2258 @item -dtb @var{file}
2260 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2269 DEFHEADING(Debug/Expert options:)
2274 DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
2275 "-serial dev redirect the serial port to char device 'dev'\n",
2278 @item -serial @var{dev}
2280 Redirect the virtual serial port to host character device
2281 @var{dev}. The default device is @code{vc} in graphical mode and
2282 @code{stdio} in non graphical mode.
2284 This option can be used several times to simulate up to 4 serial
2287 Use @code{-serial none} to disable all serial ports.
2289 Available character devices are:
2291 @item vc[:@var{W}x@var{H}]
2292 Virtual console. Optionally, a width and height can be given in pixel with
2296 It is also possible to specify width or height in characters:
2301 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
2303 No device is allocated.
2307 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2308 parameters are set according to the emulated ones.
2309 @item /dev/parport@var{N}
2310 [Linux only, parallel port only] Use host parallel port
2311 @var{N}. Currently SPP and EPP parallel port features can be used.
2312 @item file:@var{filename}
2313 Write output to @var{filename}. No character can be read.
2315 [Unix only] standard input/output
2316 @item pipe:@var{filename}
2317 name pipe @var{filename}
2319 [Windows only] Use host serial port @var{n}
2320 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
2321 This implements UDP Net Console.
2322 When @var{remote_host} or @var{src_ip} are not specified
2323 they default to @code{0.0.0.0}.
2324 When not using a specified @var{src_port} a random port is automatically chosen.
2326 If you just want a simple readonly console you can use @code{netcat} or
2327 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
2328 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
2329 will appear in the netconsole session.
2331 If you plan to send characters back via netconsole or you want to stop
2332 and start QEMU a lot of times, you should have QEMU use the same
2333 source port each time by using something like @code{-serial
2334 udp::4555@@:4556} to QEMU. Another approach is to use a patched
2335 version of netcat which can listen to a TCP port and send and receive
2336 characters via udp. If you have a patched version of netcat which
2337 activates telnet remote echo and single char transfer, then you can
2338 use the following options to step up a netcat redirector to allow
2339 telnet on port 5555 to access the QEMU port.
2342 -serial udp::4555@@:4556
2343 @item netcat options:
2344 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
2345 @item telnet options:
2349 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay]
2350 The TCP Net Console has two modes of operation. It can send the serial
2351 I/O to a location or wait for a connection from a location. By default
2352 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
2353 the @var{server} option QEMU will wait for a client socket application
2354 to connect to the port before continuing, unless the @code{nowait}
2355 option was specified. The @code{nodelay} option disables the Nagle buffering
2356 algorithm. If @var{host} is omitted, 0.0.0.0 is assumed. Only
2357 one TCP connection at a time is accepted. You can use @code{telnet} to
2358 connect to the corresponding character device.
2360 @item Example to send tcp console to 192.168.0.2 port 4444
2361 -serial tcp:192.168.0.2:4444
2362 @item Example to listen and wait on port 4444 for connection
2363 -serial tcp::4444,server
2364 @item Example to not wait and listen on ip 192.168.0.100 port 4444
2365 -serial tcp:192.168.0.100:4444,server,nowait
2368 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
2369 The telnet protocol is used instead of raw tcp sockets. The options
2370 work the same as if you had specified @code{-serial tcp}. The
2371 difference is that the port acts like a telnet server or client using
2372 telnet option negotiation. This will also allow you to send the
2373 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
2374 sequence. Typically in unix telnet you do it with Control-] and then
2375 type "send break" followed by pressing the enter key.
2377 @item unix:@var{path}[,server][,nowait]
2378 A unix domain socket is used instead of a tcp socket. The option works the
2379 same as if you had specified @code{-serial tcp} except the unix domain socket
2380 @var{path} is used for connections.
2382 @item mon:@var{dev_string}
2383 This is a special option to allow the monitor to be multiplexed onto
2384 another serial port. The monitor is accessed with key sequence of
2385 @key{Control-a} and then pressing @key{c}. See monitor access
2386 @ref{pcsys_keys} in the -nographic section for more keys.
2387 @var{dev_string} should be any one of the serial devices specified
2388 above. An example to multiplex the monitor onto a telnet server
2389 listening on port 4444 would be:
2391 @item -serial mon:telnet::4444,server,nowait
2395 Braille device. This will use BrlAPI to display the braille output on a real
2399 Three button serial mouse. Configure the guest to use Microsoft protocol.
2403 DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
2404 "-parallel dev redirect the parallel port to char device 'dev'\n",
2407 @item -parallel @var{dev}
2409 Redirect the virtual parallel port to host device @var{dev} (same
2410 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
2411 be used to use hardware devices connected on the corresponding host
2414 This option can be used several times to simulate up to 3 parallel
2417 Use @code{-parallel none} to disable all parallel ports.
2420 DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
2421 "-monitor dev redirect the monitor to char device 'dev'\n",
2424 @item -monitor @var{dev}
2426 Redirect the monitor to host device @var{dev} (same devices as the
2428 The default device is @code{vc} in graphical mode and @code{stdio} in
2431 DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
2432 "-qmp dev like -monitor but opens in 'control' mode\n",
2435 @item -qmp @var{dev}
2437 Like -monitor but opens in 'control' mode.
2440 DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
2441 "-mon chardev=[name][,mode=readline|control][,default]\n", QEMU_ARCH_ALL)
2443 @item -mon chardev=[name][,mode=readline|control][,default]
2445 Setup monitor on chardev @var{name}.
2448 DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
2449 "-debugcon dev redirect the debug console to char device 'dev'\n",
2452 @item -debugcon @var{dev}
2454 Redirect the debug console to host device @var{dev} (same devices as the
2455 serial port). The debug console is an I/O port which is typically port
2456 0xe9; writing to that I/O port sends output to this device.
2457 The default device is @code{vc} in graphical mode and @code{stdio} in
2461 DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
2462 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
2464 @item -pidfile @var{file}
2466 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
2470 DEF("singlestep", 0, QEMU_OPTION_singlestep, \
2471 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
2475 Run the emulation in single step mode.
2478 DEF("S", 0, QEMU_OPTION_S, \
2479 "-S freeze CPU at startup (use 'c' to start execution)\n",
2484 Do not start CPU at startup (you must type 'c' in the monitor).
2487 DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
2488 "-gdb dev wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
2490 @item -gdb @var{dev}
2492 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
2493 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
2494 stdio are reasonable use case. The latter is allowing to start QEMU from
2495 within gdb and establish the connection via a pipe:
2497 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
2501 DEF("s", 0, QEMU_OPTION_s, \
2502 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
2507 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
2508 (@pxref{gdb_usage}).
2511 DEF("d", HAS_ARG, QEMU_OPTION_d, \
2512 "-d item1,... output log to /tmp/qemu.log (use '-d help' for a list of log items)\n",
2517 Output log in /tmp/qemu.log
2520 DEF("D", HAS_ARG, QEMU_OPTION_D, \
2521 "-D logfile output log to logfile (instead of the default /tmp/qemu.log)\n",
2524 @item -D @var{logfile}
2526 Output log in @var{logfile} instead of /tmp/qemu.log
2529 DEF("hdachs", HAS_ARG, QEMU_OPTION_hdachs, \
2530 "-hdachs c,h,s[,t]\n" \
2531 " force hard disk 0 physical geometry and the optional BIOS\n" \
2532 " translation (t=none or lba) (usually QEMU can guess them)\n",
2535 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
2537 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
2538 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
2539 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
2540 all those parameters. This option is useful for old MS-DOS disk
2544 DEF("L", HAS_ARG, QEMU_OPTION_L, \
2545 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
2550 Set the directory for the BIOS, VGA BIOS and keymaps.
2553 DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
2554 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
2556 @item -bios @var{file}
2558 Set the filename for the BIOS.
2561 DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
2562 "-enable-kvm enable KVM full virtualization support\n", QEMU_ARCH_ALL)
2566 Enable KVM full virtualization support. This option is only available
2567 if KVM support is enabled when compiling.
2570 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
2571 "-xen-domid id specify xen guest domain id\n", QEMU_ARCH_ALL)
2572 DEF("xen-create", 0, QEMU_OPTION_xen_create,
2573 "-xen-create create domain using xen hypercalls, bypassing xend\n"
2574 " warning: should not be used when xend is in use\n",
2576 DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
2577 "-xen-attach attach to existing xen domain\n"
2578 " xend will use this when starting QEMU\n",
2581 @item -xen-domid @var{id}
2583 Specify xen guest domain @var{id} (XEN only).
2586 Create domain using xen hypercalls, bypassing xend.
2587 Warning: should not be used when xend is in use (XEN only).
2590 Attach to existing xen domain.
2591 xend will use this when starting QEMU (XEN only).
2594 DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
2595 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
2599 Exit instead of rebooting.
2602 DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
2603 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
2606 @findex -no-shutdown
2607 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
2608 This allows for instance switching to monitor to commit changes to the
2612 DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
2613 "-loadvm [tag|id]\n" \
2614 " start right away with a saved state (loadvm in monitor)\n",
2617 @item -loadvm @var{file}
2619 Start right away with a saved state (@code{loadvm} in monitor)
2623 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
2624 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
2629 Daemonize the QEMU process after initialization. QEMU will not detach from
2630 standard IO until it is ready to receive connections on any of its devices.
2631 This option is a useful way for external programs to launch QEMU without having
2632 to cope with initialization race conditions.
2635 DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
2636 "-option-rom rom load a file, rom, into the option ROM space\n",
2639 @item -option-rom @var{file}
2641 Load the contents of @var{file} as an option ROM.
2642 This option is useful to load things like EtherBoot.
2645 DEF("clock", HAS_ARG, QEMU_OPTION_clock, \
2646 "-clock force the use of the given methods for timer alarm.\n" \
2647 " To see what timers are available use '-clock help'\n",
2650 @item -clock @var{method}
2652 Force the use of the given methods for timer alarm. To see what timers
2653 are available use @code{-clock help}.
2656 HXCOMM Options deprecated by -rtc
2657 DEF("localtime", 0, QEMU_OPTION_localtime, "", QEMU_ARCH_ALL)
2658 DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "", QEMU_ARCH_ALL)
2660 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
2661 "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
2662 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
2667 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
2669 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
2670 UTC or local time, respectively. @code{localtime} is required for correct date in
2671 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
2672 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
2674 By default the RTC is driven by the host system time. This allows to use the
2675 RTC as accurate reference clock inside the guest, specifically if the host
2676 time is smoothly following an accurate external reference clock, e.g. via NTP.
2677 If you want to isolate the guest time from the host, you can set @option{clock}
2678 to @code{rt} instead. To even prevent it from progressing during suspension,
2679 you can set it to @code{vm}.
2681 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
2682 specifically with Windows' ACPI HAL. This option will try to figure out how
2683 many timer interrupts were not processed by the Windows guest and will
2687 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
2688 "-icount [N|auto]\n" \
2689 " enable virtual instruction counter with 2^N clock ticks per\n" \
2690 " instruction\n", QEMU_ARCH_ALL)
2692 @item -icount [@var{N}|auto]
2694 Enable virtual instruction counter. The virtual cpu will execute one
2695 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
2696 then the virtual cpu speed will be automatically adjusted to keep virtual
2697 time within a few seconds of real time.
2699 Note that while this option can give deterministic behavior, it does not
2700 provide cycle accurate emulation. Modern CPUs contain superscalar out of
2701 order cores with complex cache hierarchies. The number of instructions
2702 executed often has little or no correlation with actual performance.
2705 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
2706 "-watchdog i6300esb|ib700\n" \
2707 " enable virtual hardware watchdog [default=none]\n",
2710 @item -watchdog @var{model}
2712 Create a virtual hardware watchdog device. Once enabled (by a guest
2713 action), the watchdog must be periodically polled by an agent inside
2714 the guest or else the guest will be restarted.
2716 The @var{model} is the model of hardware watchdog to emulate. Choices
2717 for model are: @code{ib700} (iBASE 700) which is a very simple ISA
2718 watchdog with a single timer, or @code{i6300esb} (Intel 6300ESB I/O
2719 controller hub) which is a much more featureful PCI-based dual-timer
2720 watchdog. Choose a model for which your guest has drivers.
2722 Use @code{-watchdog help} to list available hardware models. Only one
2723 watchdog can be enabled for a guest.
2726 DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
2727 "-watchdog-action reset|shutdown|poweroff|pause|debug|none\n" \
2728 " action when watchdog fires [default=reset]\n",
2731 @item -watchdog-action @var{action}
2732 @findex -watchdog-action
2734 The @var{action} controls what QEMU will do when the watchdog timer
2737 @code{reset} (forcefully reset the guest).
2738 Other possible actions are:
2739 @code{shutdown} (attempt to gracefully shutdown the guest),
2740 @code{poweroff} (forcefully poweroff the guest),
2741 @code{pause} (pause the guest),
2742 @code{debug} (print a debug message and continue), or
2743 @code{none} (do nothing).
2745 Note that the @code{shutdown} action requires that the guest responds
2746 to ACPI signals, which it may not be able to do in the sort of
2747 situations where the watchdog would have expired, and thus
2748 @code{-watchdog-action shutdown} is not recommended for production use.
2753 @item -watchdog i6300esb -watchdog-action pause
2754 @item -watchdog ib700
2758 DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
2759 "-echr chr set terminal escape character instead of ctrl-a\n",
2763 @item -echr @var{numeric_ascii_value}
2765 Change the escape character used for switching to the monitor when using
2766 monitor and serial sharing. The default is @code{0x01} when using the
2767 @code{-nographic} option. @code{0x01} is equal to pressing
2768 @code{Control-a}. You can select a different character from the ascii
2769 control keys where 1 through 26 map to Control-a through Control-z. For
2770 instance you could use the either of the following to change the escape
2771 character to Control-t.
2778 DEF("virtioconsole", HAS_ARG, QEMU_OPTION_virtiocon, \
2779 "-virtioconsole c\n" \
2780 " set virtio console\n", QEMU_ARCH_ALL)
2782 @item -virtioconsole @var{c}
2783 @findex -virtioconsole
2786 This option is maintained for backward compatibility.
2788 Please use @code{-device virtconsole} for the new way of invocation.
2791 DEF("show-cursor", 0, QEMU_OPTION_show_cursor, \
2792 "-show-cursor show cursor\n", QEMU_ARCH_ALL)
2795 @findex -show-cursor
2799 DEF("tb-size", HAS_ARG, QEMU_OPTION_tb_size, \
2800 "-tb-size n set TB size\n", QEMU_ARCH_ALL)
2802 @item -tb-size @var{n}
2807 DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
2808 "-incoming p prepare for incoming migration, listen on port p\n",
2811 @item -incoming @var{port}
2813 Prepare for incoming migration, listen on @var{port}.
2816 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
2817 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
2821 Don't create default devices. Normally, QEMU sets the default devices like serial
2822 port, parallel port, virtual console, monitor device, VGA adapter, floppy and
2823 CD-ROM drive and others. The @code{-nodefaults} option will disable all those
2828 DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
2829 "-chroot dir chroot to dir just before starting the VM\n",
2833 @item -chroot @var{dir}
2835 Immediately before starting guest execution, chroot to the specified
2836 directory. Especially useful in combination with -runas.
2840 DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
2841 "-runas user change to user id user just before starting the VM\n",
2845 @item -runas @var{user}
2847 Immediately before starting guest execution, drop root privileges, switching
2848 to the specified user.
2851 DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
2852 "-prom-env variable=value\n"
2853 " set OpenBIOS nvram variables\n",
2854 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
2856 @item -prom-env @var{variable}=@var{value}
2858 Set OpenBIOS nvram @var{variable} to given @var{value} (PPC, SPARC only).
2860 DEF("semihosting", 0, QEMU_OPTION_semihosting,
2861 "-semihosting semihosting mode\n", QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA)
2864 @findex -semihosting
2865 Semihosting mode (ARM, M68K, Xtensa only).
2867 DEF("old-param", 0, QEMU_OPTION_old_param,
2868 "-old-param old param mode\n", QEMU_ARCH_ARM)
2871 @findex -old-param (ARM)
2872 Old param mode (ARM only).
2875 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
2876 "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n",
2879 @item -sandbox @var{arg}
2881 Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will
2882 disable it. The default is 'off'.
2885 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
2886 "-readconfig <file>\n", QEMU_ARCH_ALL)
2888 @item -readconfig @var{file}
2890 Read device configuration from @var{file}. This approach is useful when you want to spawn
2891 QEMU process with many command line options but you don't want to exceed the command line
2894 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
2895 "-writeconfig <file>\n"
2896 " read/write config file\n", QEMU_ARCH_ALL)
2898 @item -writeconfig @var{file}
2899 @findex -writeconfig
2900 Write device configuration to @var{file}. The @var{file} can be either filename to save
2901 command line and device configuration into file or dash @code{-}) character to print the
2902 output to stdout. This can be later used as input file for @code{-readconfig} option.
2904 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
2906 " do not load default config files at startup\n",
2910 @findex -nodefconfig
2911 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
2912 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
2914 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
2916 " do not load user-provided config files at startup\n",
2919 @item -no-user-config
2920 @findex -no-user-config
2921 The @code{-no-user-config} option makes QEMU not load any of the user-provided
2922 config files on @var{sysconfdir}, but won't make it skip the QEMU-provided config
2923 files from @var{datadir}.
2925 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
2926 "-trace [events=<file>][,file=<file>]\n"
2927 " specify tracing options\n",
2930 HXCOMM This line is not accurate, as some sub-options are backend-specific but
2931 HXCOMM HX does not support conditional compilation of text.
2932 @item -trace [events=@var{file}][,file=@var{file}]
2935 Specify tracing options.
2938 @item events=@var{file}
2939 Immediately enable events listed in @var{file}.
2940 The file must contain one event name (as listed in the @var{trace-events} file)
2942 This option is only available if QEMU has been compiled with
2943 either @var{simple} or @var{stderr} tracing backend.
2944 @item file=@var{file}
2945 Log output traces to @var{file}.
2947 This option is only available if QEMU has been compiled with
2948 the @var{simple} tracing backend.
2953 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
2954 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
2957 DEF("enable-fips", 0, QEMU_OPTION_enablefips,
2958 "-enable-fips enable FIPS 140-2 compliance\n",
2963 @findex -enable-fips
2964 Enable FIPS 140-2 compliance mode.
2967 HXCOMM Deprecated by -machine accel=tcg property
2968 DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
2970 HXCOMM Deprecated by kvm-pit driver properties
2971 DEF("no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection,
2974 HXCOMM Deprecated (ignored)
2975 DEF("no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit, "", QEMU_ARCH_I386)
2977 HXCOMM Deprecated by -machine kernel_irqchip=on|off property
2978 DEF("no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip, "", QEMU_ARCH_I386)
2980 HXCOMM Deprecated (ignored)
2981 DEF("tdf", 0, QEMU_OPTION_tdf,"", QEMU_ARCH_ALL)
2983 DEF("object", HAS_ARG, QEMU_OPTION_object,
2984 "-object TYPENAME[,PROP1=VALUE1,...]\n"
2985 " create an new object of type TYPENAME setting properties\n"
2986 " in the order they are specified. Note that the 'id'\n"
2987 " property must be set. These objects are placed in the\n"
2988 " '/objects' path.\n",
2991 @item -object @var{typename}[,@var{prop1}=@var{value1},...]
2993 Create an new object of type @var{typename} setting properties
2994 in the order they are specified. Note that the 'id'
2995 property must be set. These objects are placed in the
2999 HXCOMM This is the last statement. Insert new options before this line!