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2 HXCOMM Text between STEXI and ETEXI are copied to texi version and
3 HXCOMM discarded from C version
6 HXCOMM architectures.
10 STEXI
11 @table @option
12 ETEXI
16 STEXI
17 @item -h
18 @findex -h
19 Display help and exit
20 ETEXI
24 STEXI
25 @item -version
26 @findex -version
27 Display version information and exit
28 ETEXI
46 QEMU_ARCH_ALL)
47 STEXI
49 @findex -machine
52 @table @option
57 to initialize.
58 @item kernel_irqchip=on|off
60 @item gfx_passthru=on|off
62 @item vmport=on|off|auto
65 is on.
66 @item kvm_shadow_mem=size
67 Defines the size of the KVM shadow MMU.
76 controls whether AES wrapping keys will be created to allow
80 controls whether DEA wrapping keys will be created to allow
82 @item nvdimm=on|off
84 @end table
85 ETEXI
87 HXCOMM Deprecated by -machine
92 STEXI
94 @findex -cpu
96 ETEXI
102 STEXI
104 @findex -accel
108 to initialize.
109 @table @option
110 @item thread=single|multi
115 @end table
116 ETEXI
126 QEMU_ARCH_ALL)
127 STEXI
128 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
129 @findex -smp
137 specifies the maximum number of hotpluggable CPUs.
138 ETEXI
143 STEXI
146 @findex -numa
147 Define a NUMA node and assign RAM and VCPUs to it.
154 split between them.
157 a NUMA node:
158 @example
160 @end example
163 assigns RAM from a given memory backend device to a node. If
165 split equally between them.
171 specified resources, it just assigns existing resources to NUMA
172 nodes. This means that one still has to use the @option{-m},
173 @option{-smp} options to allocate RAM and VCPUs respectively.
175 ETEXI
177 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
180 STEXI
181 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
182 @findex -add-fd
184 Add a file descriptor to an fd set. Valid options are:
186 @table @option
187 @item fd=@var{fd}
188 This option defines the file descriptor of which a duplicate is added to fd set.
189 The file descriptor cannot be stdin, stdout, or stderr.
190 @item set=@var{set}
191 This option defines the ID of the fd set to add the file descriptor to.
192 @item opaque=@var{opaque}
193 This option defines a free-form string that can be used to describe @var{fd}.
194 @end table
196 You can open an image using pre-opened file descriptors from an fd set:
197 @example
198 qemu-system-i386
199 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
200 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
201 -drive file=/dev/fdset/2,index=0,media=disk
202 @end example
203 ETEXI
205 DEF("set", HAS_ARG, QEMU_OPTION_set,
209 STEXI
210 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
211 @findex -set
212 Set parameter @var{arg} for item @var{id} of type @var{group}
213 ETEXI
215 DEF("global", HAS_ARG, QEMU_OPTION_global,
219 QEMU_ARCH_ALL)
220 STEXI
221 @item -global @var{driver}.@var{prop}=@var{value}
222 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
223 @findex -global
226 @example
227 qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk
228 @end example
231 created automatically by the machine model. To create a device which is not
237 ETEXI
246 QEMU_ARCH_ALL)
247 STEXI
248 @item -boot [order=@var{drives}][,once=@var{drives}][,menu=on|off][,splash=@var{sp_name}][,splash-time=@var{sp_time}][,reboot-timeout=@var{rb_timeout}][,strict=on|off]
249 @findex -boot
254 particular boot order only on the first startup, specify it via
258 at the same time.
273 system support it.
276 supports it. This only effects when boot priority is changed by
279 @example
286 @end example
289 use is discouraged as it may be removed from future versions.
290 ETEXI
299 QEMU_ARCH_ALL)
300 STEXI
302 @findex -m
306 could be used to set amount of hotpluggable memory slots and maximum amount of
313 @example
315 @end example
318 be enabled and the guest startup RAM will never increase.
319 ETEXI
321 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
323 STEXI
324 @item -mem-path @var{path}
325 @findex -mem-path
326 Allocate guest RAM from a temporarily created file in @var{path}.
327 ETEXI
329 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
331 QEMU_ARCH_ALL)
332 STEXI
333 @item -mem-prealloc
334 @findex -mem-prealloc
335 Preallocate memory when using -mem-path.
336 ETEXI
338 DEF("k", HAS_ARG, QEMU_OPTION_k,
340 QEMU_ARCH_ALL)
341 STEXI
342 @item -k @var{language}
343 @findex -k
344 Use keyboard layout @var{language} (for example @code{fr} for
345 French). This option is only needed where it is not easy to get raw PC
346 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
348 hosts.
350 The available layouts are:
351 @example
355 @end example
358 ETEXI
363 QEMU_ARCH_ALL)
364 STEXI
368 parameters.
369 ETEXI
376 STEXI
378 @findex -soundhw
380 available sound hardware.
382 @example
389 @end example
391 Note that Linux's i810_audio OSS kernel (for AC97) module might
392 require manually specifying clocking.
394 @example
395 modprobe i810_audio clocking=48000
396 @end example
397 ETEXI
399 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
403 STEXI
404 @item -balloon none
405 @findex -balloon
406 Disable balloon device.
407 @item -balloon virtio[,addr=@var{addr}]
408 Enable virtio balloon device (default), optionally with PCI address
409 @var{addr}.
410 ETEXI
412 DEF("device", HAS_ARG, QEMU_OPTION_device,
418 QEMU_ARCH_ALL)
419 STEXI
420 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
421 @findex -device
422 Add device @var{driver}. @var{prop}=@var{value} sets driver
423 properties. Valid properties depend on the driver. To get help on
424 possible drivers and properties, use @code{-device help} and
425 @code{-device @var{driver},help}.
427 Some drivers are:
428 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
430 Add an IPMI BMC. This is a simulation of a hardware management
431 interface processor that normally sits on a system. It provides
432 a watchdog and the ability to reset and power control the system.
433 You need to connect this to an IPMI interface to make it useful
435 The IPMI slave address to use for the BMC. The default is 0x20.
436 This address is the BMC's address on the I2C network of management
438 it.
440 @table @option
441 @item bmc=@var{id}
442 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
443 @item slave_addr=@var{val}
444 Define slave address to use for the BMC. The default is 0x20.
445 @item sdrfile=@var{file}
446 file containing raw Sensor Data Records (SDR) data. The default is none.
447 @item fruareasize=@var{val}
448 size of a Field Replaceable Unit (FRU) area. The default is 1024.
449 @item frudatafile=@var{file}
450 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
451 @end table
453 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
455 Add a connection to an external IPMI BMC simulator. Instead of
456 locally emulating the BMC like the above item, instead connect
457 to an external entity that provides the IPMI services.
459 A connection is made to an external BMC simulator. If you do this, it
460 is strongly recommended that you use the "reconnect=" chardev option
461 to reconnect to the simulator if the connection is lost. Note that if
462 this is not used carefully, it can be a security issue, as the
463 interface has the ability to send resets, NMIs, and power off the VM.
465 on a secure port on localhost, so neither the simulator nor QEMU is
466 exposed to any outside network.
473 Add a KCS IPMI interafce on the ISA bus. This also adds a
476 @table @option
484 @end table
491 ETEXI
499 QEMU_ARCH_ALL)
500 STEXI
502 @findex -name
507 Naming of individual threads can also be enabled on Linux to aid debugging.
508 ETEXI
513 STEXI
515 @findex -uuid
516 Set system UUID.
517 ETEXI
519 STEXI
520 @end table
521 ETEXI
525 STEXI
526 @table @option
527 ETEXI
532 STEXI
535 @findex -fda
536 @findex -fdb
538 ETEXI
546 STEXI
551 @findex -hda
552 @findex -hdb
553 @findex -hdc
554 @findex -hdd
556 ETEXI
560 QEMU_ARCH_ALL)
561 STEXI
563 @findex -cdrom
567 ETEXI
591 STEXI
593 @findex -drive
597 @table @option
603 Special files such as iSCSI devices can be specified using protocol
609 These options define where is connected the drive by defining the bus number and
610 the unit id.
622 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
624 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
626 @var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap}) requests are ignored or passed to the filesystem. Some machine types may not support discard requests.
630 an untrusted format header.
632 This option specifies the serial number to assign to the device.
634 Specify the controller's PCI address (if=virtio only).
635 @item werror=@var{action},rerror=@var{action}
636 Specify which @var{action} to take on write and read errors. Valid actions are:
637 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
638 "report" (report the error to the guest), "enospc" (pause QEMU only if the
639 host disk is full; report the error to the guest otherwise).
640 The default setting is @option{werror=enospc} and @option{rerror=report}.
641 @item readonly
642 Open drive @option{file} as read-only. Guest write attempts will fail.
643 @item copy-on-read=@var{copy-on-read}
644 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
645 file sectors into the image file.
646 @item detect-zeroes=@var{detect-zeroes}
647 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
648 conversion of plain zero writes by the OS to driver specific optimized
649 zero write commands. You may even choose "unmap" if @var{discard} is set
650 to "unmap" to allow a zero write to be converted to an UNMAP operation.
651 @item bps=@var{b},bps_rd=@var{r},bps_wr=@var{w}
652 Specify bandwidth throttling limits in bytes per second, either for all request
653 types or for reads or writes only. Small values can lead to timeouts or hangs
654 inside the guest. A safe minimum for disks is 2 MB/s.
655 @item bps_max=@var{bm},bps_rd_max=@var{rm},bps_wr_max=@var{wm}
656 Specify bursts in bytes per second, either for all request types or for reads
657 or writes only. Bursts allow the guest I/O to spike above the limit
658 temporarily.
659 @item iops=@var{i},iops_rd=@var{r},iops_wr=@var{w}
660 Specify request rate limits in requests per second, either for all request
661 types or for reads or writes only.
662 @item iops_max=@var{bm},iops_rd_max=@var{rm},iops_wr_max=@var{wm}
663 Specify bursts in requests per second, either for all request types or for reads
664 or writes only. Bursts allow the guest I/O to spike above the limit
665 temporarily.
666 @item iops_size=@var{is}
667 Let every @var{is} bytes of a request count as a new request for iops
668 throttling purposes. Use this option to prevent guests from circumventing iops
669 limits by sending fewer but larger requests.
670 @item group=@var{g}
671 Join a throttling quota group with given name @var{g}. All drives that are
672 members of the same group are accounted for together. Use this option to
673 prevent guests from circumventing throttling limits by using many small disks
674 instead of a single larger disk.
675 @end table
677 By default, the @option{cache=writeback} mode is used. It will report data
678 writes as completed as soon as the data is present in the host page cache.
679 This is safe as long as your guest OS makes sure to correctly flush disk caches
680 where needed. If your guest OS does not handle volatile disk write caches
681 correctly and your host crashes or loses power, then the guest may experience
682 data corruption.
684 For such guests, you should consider using @option{cache=writethrough}. This
685 means that the host page cache will be used to read and write data, but write
686 notification will be sent to the guest only after QEMU has made sure to flush
687 each write to the disk. Be aware that this has a major impact on performance.
689 The host page cache can be avoided entirely with @option{cache=none}. This will
692 the guest OS must handle the disk write cache correctly in order to avoid data
693 corruption on host crashes.
695 The host page cache can be avoided while only sending write notifications to
696 the guest when the data has been flushed to the disk using
700 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
701 data to the disk but can instead keep things in cache. If anything goes wrong,
702 like your host losing power, the disk storage getting disconnected accidentally,
703 etc. your image will most probably be rendered unusable. When using
704 the @option{-snapshot} option, unsafe caching is always used.
706 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
707 useful when the backing file is over a slow network. By default copy-on-read
708 is off.
710 Instead of @option{-cdrom} you can use:
711 @example
712 qemu-system-i386 -drive file=file,index=2,media=cdrom
713 @end example
715 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
716 use:
717 @example
718 qemu-system-i386 -drive file=file,index=0,media=disk
719 qemu-system-i386 -drive file=file,index=1,media=disk
720 qemu-system-i386 -drive file=file,index=2,media=disk
721 qemu-system-i386 -drive file=file,index=3,media=disk
722 @end example
724 You can open an image using pre-opened file descriptors from an fd set:
725 @example
726 qemu-system-i386
727 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
728 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
729 -drive file=/dev/fdset/2,index=0,media=disk
730 @end example
732 You can connect a CDROM to the slave of ide0:
733 @example
734 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
735 @end example
738 @example
740 @end example
743 @example
746 @end example
749 incremented:
750 @example
752 @end example
753 is interpreted like:
754 @example
755 qemu-system-i386 -hda a -hdb b
756 @end example
757 ETEXI
761 QEMU_ARCH_ALL)
762 STEXI
763 @item -mtdblock @var{file}
764 @findex -mtdblock
765 Use @var{file} as on-board Flash memory image.
766 ETEXI
770 STEXI
771 @item -sd @var{file}
772 @findex -sd
773 Use @var{file} as SecureDigital card image.
774 ETEXI
778 STEXI
779 @item -pflash @var{file}
780 @findex -pflash
781 Use @var{file} as a parallel flash image.
782 ETEXI
786 QEMU_ARCH_ALL)
787 STEXI
788 @item -snapshot
789 @findex -snapshot
790 Write to temporary files instead of disk image files. In this case,
791 the raw disk image you use is not written back. You can however force
792 the write back by pressing @key{C-a s} (@pxref{disk_images}).
793 ETEXI
799 QEMU_ARCH_ALL)
800 STEXI
801 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
802 @findex -hdachs
803 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
804 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
805 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
806 all those parameters. This option is useful for old MS-DOS disk
807 images.
808 ETEXI
811 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
815 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
816 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
818 QEMU_ARCH_ALL)
820 STEXI
822 @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}]
823 @findex -fsdev
824 Define a new file system device. Valid options are:
825 @table @option
826 @item @var{fsdriver}
827 This option specifies the fs driver backend to use.
829 @item id=@var{id}
830 Specifies identifier for this device
831 @item path=@var{path}
832 Specifies the export path for the file system device. Files under
833 this path will be available to the 9p client on the guest.
834 @item security_model=@var{security_model}
835 Specifies the security model to be used for this export path.
838 credentials as they are created on the guest. This requires QEMU
840 attributes like uid, gid, mode bits and link target are stored as
842 hidden .virtfs_metadata directory. Directories exported by this security model cannot
844 passthrough except the sever won't report failures if it fails to
845 set file attributes like ownership. Security model is mandatory
846 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
847 security model as a parameter.
848 @item writeout=@var{writeout}
850 This means that host page cache will be used to read and write data but
851 write notification will be sent to the guest only when the data has been
852 reported as written by the storage subsystem.
853 @item readonly
854 Enables exporting 9p share as a readonly mount for guests. By default
855 read-write access is given.
856 @item socket=@var{socket}
857 Enables proxy filesystem driver to use passed socket file for communicating
858 with virtfs-proxy-helper
859 @item sock_fd=@var{sock_fd}
860 Enables proxy filesystem driver to use passed socket descriptor for
861 communicating with virtfs-proxy-helper. Usually a helper like libvirt
862 will create socketpair and pass one of the fds as sock_fd
863 @end table
866 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
867 Options for virtio-9p-pci driver are:
868 @table @option
869 @item fsdev=@var{id}
870 Specifies the id value specified along with -fsdev option
871 @item mount_tag=@var{mount_tag}
872 Specifies the tag name to be used by the guest to mount this export point
873 @end table
875 ETEXI
878 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
880 QEMU_ARCH_ALL)
882 STEXI
884 @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}]
885 @findex -virtfs
887 The general form of a Virtual File system pass-through options are:
888 @table @option
889 @item @var{fsdriver}
890 This option specifies the fs driver backend to use.
892 @item id=@var{id}
893 Specifies identifier for this device
894 @item path=@var{path}
895 Specifies the export path for the file system device. Files under
896 this path will be available to the 9p client on the guest.
897 @item security_model=@var{security_model}
898 Specifies the security model to be used for this export path.
901 credentials as they are created on the guest. This requires QEMU
903 attributes like uid, gid, mode bits and link target are stored as
905 hidden .virtfs_metadata directory. Directories exported by this security model cannot
907 passthrough except the sever won't report failures if it fails to
908 set file attributes like ownership. Security model is mandatory only
909 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
910 model as a parameter.
911 @item writeout=@var{writeout}
913 This means that host page cache will be used to read and write data but
914 write notification will be sent to the guest only when the data has been
915 reported as written by the storage subsystem.
916 @item readonly
917 Enables exporting 9p share as a readonly mount for guests. By default
918 read-write access is given.
919 @item socket=@var{socket}
920 Enables proxy filesystem driver to use passed socket file for
921 communicating with virtfs-proxy-helper. Usually a helper like libvirt
922 will create socketpair and pass one of the fds as sock_fd
923 @item sock_fd
924 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
925 descriptor for interfacing with virtfs-proxy-helper
926 @end table
927 ETEXI
931 QEMU_ARCH_ALL)
932 STEXI
933 @item -virtfs_synth
934 @findex -virtfs_synth
935 Create synthetic file system image
936 ETEXI
938 STEXI
939 @end table
940 ETEXI
941 DEFHEADING()
943 DEFHEADING(USB options)
944 STEXI
945 @table @option
946 ETEXI
950 QEMU_ARCH_ALL)
951 STEXI
952 @item -usb
953 @findex -usb
954 Enable the USB driver (will be the default soon)
955 ETEXI
959 QEMU_ARCH_ALL)
960 STEXI
962 @item -usbdevice @var{devname}
963 @findex -usbdevice
964 Add the USB device @var{devname}. @xref{usb_devices}.
966 @table @option
968 @item mouse
969 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
971 @item tablet
972 Pointer device that uses absolute coordinates (like a touchscreen). This
973 means QEMU is able to report the mouse position without having to grab the
974 mouse. Also overrides the PS/2 mouse emulation when activated.
976 @item disk:[format=@var{format}]:@var{file}
977 Mass storage device based on file. The optional @var{format} argument
978 will be used rather than detecting the format. Can be used to specify
979 @code{format=raw} to avoid interpreting an untrusted format header.
981 @item host:@var{bus}.@var{addr}
982 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
984 @item host:@var{vendor_id}:@var{product_id}
985 Pass through the host device identified by @var{vendor_id}:@var{product_id}
986 (Linux only).
988 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
989 Serial converter to host character device @var{dev}, see @code{-serial} for the
990 available devices.
992 @item braille
993 Braille device. This will use BrlAPI to display the braille output on a real
994 or fake device.
996 @item net:@var{options}
997 Network adapter that supports CDC ethernet and RNDIS protocols.
999 @end table
1000 ETEXI
1002 STEXI
1003 @end table
1004 ETEXI
1005 DEFHEADING()
1007 DEFHEADING(Display options)
1008 STEXI
1009 @table @option
1010 ETEXI
1021 #if defined(CONFIG_GTK)
1023 #elif defined(CONFIG_SDL)
1025 #elif defined(CONFIG_COCOA)
1027 #elif defined(CONFIG_VNC)
1029 #else
1031 #endif
1032 , QEMU_ARCH_ALL)
1033 STEXI
1034 @item -display @var{type}
1035 @findex -display
1036 Select type of display to use. This option is a replacement for the
1037 old style -sdl/-curses/... options. Valid values for @var{type} are
1038 @table @option
1039 @item sdl
1040 Display video output via SDL (usually in a separate graphics
1041 window; see the SDL documentation for other possibilities).
1042 @item curses
1043 Display video output via curses. For graphics device models which
1044 support a text mode, QEMU can display this output using a
1045 curses/ncurses interface. Nothing is displayed when the graphics
1046 device is in graphical mode or if the graphics device does not support
1047 a text mode. Generally only the VGA device models support text mode.
1048 @item none
1049 Do not display video output. The guest will still see an emulated
1050 graphics card, but its output will not be displayed to the QEMU
1051 user. This option differs from the -nographic option in that it
1052 only affects what is done with video output; -nographic also changes
1053 the destination of the serial and parallel port data.
1054 @item gtk
1055 Display video output in a GTK window. This interface provides drop-down
1056 menus and other UI elements to configure and control the VM during
1057 runtime.
1058 @item vnc
1059 Start a VNC server on display <arg>
1060 @end table
1061 ETEXI
1065 QEMU_ARCH_ALL)
1066 STEXI
1067 @item -nographic
1068 @findex -nographic
1069 Normally, if QEMU is compiled with graphical window support, it displays
1070 output such as guest graphics, guest console, and the QEMU monitor in a
1071 window. With this option, you can totally disable graphical output so
1072 that QEMU is a simple command line application. The emulated serial port
1073 is redirected on the console and muxed with the monitor (unless
1074 redirected elsewhere explicitly). Therefore, you can still use QEMU to
1075 debug a Linux kernel with a serial console. Use @key{C-a h} for help on
1076 switching between the console and monitor.
1077 ETEXI
1081 QEMU_ARCH_ALL)
1082 STEXI
1083 @item -curses
1084 @findex -curses
1085 Normally, if QEMU is compiled with graphical window support, it displays
1086 output such as guest graphics, guest console, and the QEMU monitor in a
1087 window. With this option, QEMU can display the VGA output when in text
1088 mode using a curses/ncurses interface. Nothing is displayed in graphical
1089 mode.
1090 ETEXI
1094 QEMU_ARCH_ALL)
1095 STEXI
1096 @item -no-frame
1097 @findex -no-frame
1098 Do not use decorations for SDL windows and start them using the whole
1099 available screen space. This makes the using QEMU in a dedicated desktop
1100 workspace more convenient.
1101 ETEXI
1105 QEMU_ARCH_ALL)
1106 STEXI
1107 @item -alt-grab
1108 @findex -alt-grab
1109 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1110 affects the special keys (for fullscreen, monitor-mode switching, etc).
1111 ETEXI
1115 QEMU_ARCH_ALL)
1116 STEXI
1117 @item -ctrl-grab
1118 @findex -ctrl-grab
1119 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1120 affects the special keys (for fullscreen, monitor-mode switching, etc).
1121 ETEXI
1125 STEXI
1126 @item -no-quit
1127 @findex -no-quit
1128 Disable SDL window close capability.
1129 ETEXI
1133 STEXI
1134 @item -sdl
1135 @findex -sdl
1136 Enable SDL.
1137 ETEXI
1157 QEMU_ARCH_ALL)
1158 STEXI
1159 @item -spice @var{option}[,@var{option}[,...]]
1160 @findex -spice
1161 Enable the spice remote desktop protocol. Valid options are
1163 @table @option
1165 @item port=<nr>
1166 Set the TCP port spice is listening on for plaintext channels.
1168 @item addr=<addr>
1169 Set the IP address spice is listening on. Default is any address.
1171 @item ipv4
1172 @itemx ipv6
1173 @itemx unix
1174 Force using the specified IP version.
1176 @item password=<secret>
1177 Set the password you need to authenticate.
1179 @item sasl
1180 Require that the client use SASL to authenticate with the spice.
1181 The exact choice of authentication method used is controlled from the
1182 system / user's SASL configuration file for the 'qemu' service. This
1183 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1184 unprivileged user, an environment variable SASL_CONF_PATH can be used
1185 to make it search alternate locations for the service config.
1186 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1187 it is recommended that SASL always be combined with the 'tls' and
1188 'x509' settings to enable use of SSL and server certificates. This
1189 ensures a data encryption preventing compromise of authentication
1190 credentials.
1192 @item disable-ticketing
1193 Allow client connects without authentication.
1195 @item disable-copy-paste
1196 Disable copy paste between the client and the guest.
1198 @item disable-agent-file-xfer
1199 Disable spice-vdagent based file-xfer between the client and the guest.
1201 @item tls-port=<nr>
1202 Set the TCP port spice is listening on for encrypted channels.
1204 @item x509-dir=<dir>
1205 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1207 @item x509-key-file=<file>
1208 @itemx x509-key-password=<file>
1209 @itemx x509-cert-file=<file>
1210 @itemx x509-cacert-file=<file>
1211 @itemx x509-dh-key-file=<file>
1212 The x509 file names can also be configured individually.
1214 @item tls-ciphers=<list>
1215 Specify which ciphers to use.
1217 @item tls-channel=[main|display|cursor|inputs|record|playback]
1218 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1219 Force specific channel to be used with or without TLS encryption. The
1220 options can be specified multiple times to configure multiple
1222 mode. For channels which are not explicitly forced into one mode the
1223 spice client is allowed to pick tls/plaintext as he pleases.
1225 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1226 Configure image compression (lossless).
1227 Default is auto_glz.
1229 @item jpeg-wan-compression=[auto|never|always]
1230 @itemx zlib-glz-wan-compression=[auto|never|always]
1231 Configure wan image compression (lossy for slow links).
1232 Default is auto.
1234 @item streaming-video=[off|all|filter]
1235 Configure video stream detection. Default is off.
1237 @item agent-mouse=[on|off]
1238 Enable/disable passing mouse events via vdagent. Default is on.
1240 @item playback-compression=[on|off]
1241 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1243 @item seamless-migration=[on|off]
1244 Enable/disable spice seamless migration. Default is off.
1246 @item gl=[on|off]
1247 Enable/disable OpenGL context. Default is off.
1249 @item rendernode=<file>
1250 DRM render node for OpenGL rendering. If not specified, it will pick
1251 the first available. (Since 2.9)
1253 @end table
1254 ETEXI
1258 QEMU_ARCH_ALL)
1259 STEXI
1260 @item -portrait
1261 @findex -portrait
1262 Rotate graphical output 90 deg left (only PXA LCD).
1263 ETEXI
1267 QEMU_ARCH_ALL)
1268 STEXI
1269 @item -rotate @var{deg}
1270 @findex -rotate
1271 Rotate graphical output some deg left (only PXA LCD).
1272 ETEXI
1277 STEXI
1278 @item -vga @var{type}
1279 @findex -vga
1280 Select type of VGA card to emulate. Valid values for @var{type} are
1281 @table @option
1282 @item cirrus
1283 Cirrus Logic GD5446 Video card. All Windows versions starting from
1284 Windows 95 should recognize and use this graphic card. For optimal
1285 performances, use 16 bit color depth in the guest and the host OS.
1286 (This card was the default before QEMU 2.2)
1287 @item std
1288 Standard VGA card with Bochs VBE extensions. If your guest OS
1289 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1290 to use high resolution modes (>= 1280x1024x16) then you should use
1291 this option. (This card is the default since QEMU 2.2)
1292 @item vmware
1293 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1294 recent XFree86/XOrg server or Windows guest with a driver for this
1295 card.
1296 @item qxl
1297 QXL paravirtual graphic card. It is VGA compatible (including VESA
1298 2.0 VBE support). Works best with qxl guest drivers installed though.
1299 Recommended choice when using the spice protocol.
1300 @item tcx
1301 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1302 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1303 fixed resolution of 1024x768.
1304 @item cg3
1305 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1306 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1307 resolutions aimed at people wishing to run older Solaris versions.
1308 @item virtio
1309 Virtio VGA card.
1310 @item none
1311 Disable VGA card.
1312 @end table
1313 ETEXI
1317 STEXI
1318 @item -full-screen
1319 @findex -full-screen
1320 Start in full screen.
1321 ETEXI
1325 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1326 STEXI
1327 @item -g @var{width}x@var{height}[x@var{depth}]
1328 @findex -g
1329 Set the initial graphical resolution and depth (PPC, SPARC only).
1330 ETEXI
1334 STEXI
1335 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1336 @findex -vnc
1337 Normally, if QEMU is compiled with graphical window support, it displays
1338 output such as guest graphics, guest console, and the QEMU monitor in a
1339 window. With this option, you can have QEMU listen on VNC display
1340 @var{display} and redirect the VGA display over the VNC session. It is
1341 very useful to enable the usb tablet device when using this option
1342 (option @option{-usbdevice tablet}). When using the VNC display, you
1343 must use the @option{-k} parameter to set the keyboard layout if you are
1344 not using en-us. Valid syntax for the @var{display} is
1346 @table @option
1348 @item to=@var{L}
1350 With this option, QEMU will try next available VNC @var{display}s, until the
1352 available, e.g. port 5900+@var{display} is already used by another
1353 application. By default, to=0.
1355 @item @var{host}:@var{d}
1357 TCP connections will only be allowed from @var{host} on display @var{d}.
1358 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1359 be omitted in which case the server will accept connections from any host.
1361 @item unix:@var{path}
1363 Connections will be allowed over UNIX domain sockets where @var{path} is the
1364 location of a unix socket to listen for connections on.
1366 @item none
1368 VNC is initialized but not started. The monitor @code{change} command
1369 can be used to later start the VNC server.
1371 @end table
1373 Following the @var{display} value there may be one or more @var{option} flags
1374 separated by commas. Valid options are
1376 @table @option
1378 @item reverse
1380 Connect to a listening VNC client via a ``reverse'' connection. The
1381 client is specified by the @var{display}. For reverse network
1382 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1383 is a TCP port number, not a display number.
1385 @item websocket
1387 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1388 If a bare @var{websocket} option is given, the Websocket port is
1389 5700+@var{display}. An alternative port can be specified with the
1390 syntax @code{websocket}=@var{port}.
1392 If @var{host} is specified connections will only be allowed from this host.
1393 It is possible to control the websocket listen address independently, using
1394 the syntax @code{websocket}=@var{host}:@var{port}.
1396 If no TLS credentials are provided, the websocket connection runs in
1397 unencrypted mode. If TLS credentials are provided, the websocket connection
1398 requires encrypted client connections.
1400 @item password
1402 Require that password based authentication is used for client connections.
1404 The password must be set separately using the @code{set_password} command in
1405 the @ref{pcsys_monitor}. The syntax to change your password is:
1406 @code{set_password <protocol> <password>} where <protocol> could be either
1409 If you would like to change <protocol> password expiration, you should use
1410 @code{expire_password <protocol> <expiration-time>} where expiration time could
1411 be one of the following options: now, never, +seconds or UNIX time of
1412 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1414 date and time).
1417 allow <protocol> password to expire immediately or never expire.
1419 @item tls-creds=@var{ID}
1421 Provides the ID of a set of TLS credentials to use to secure the
1422 VNC server. They will apply to both the normal VNC server socket
1423 and the websocket socket (if enabled). Setting TLS credentials
1424 will cause the VNC server socket to enable the VeNCrypt auth
1425 mechanism. The credentials should have been previously created
1426 using the @option{-object tls-creds} argument.
1428 The @option{tls-creds} parameter obsoletes the @option{tls},
1429 @option{x509}, and @option{x509verify} options, and as such
1430 it is not permitted to set both new and old type options at
1431 the same time.
1433 @item tls
1435 Require that client use TLS when communicating with the VNC server. This
1436 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1437 attack. It is recommended that this option be combined with either the
1438 @option{x509} or @option{x509verify} options.
1440 This option is now deprecated in favor of using the @option{tls-creds}
1441 argument.
1443 @item x509=@var{/path/to/certificate/dir}
1445 Valid if @option{tls} is specified. Require that x509 credentials are used
1446 for negotiating the TLS session. The server will send its x509 certificate
1447 to the client. It is recommended that a password be set on the VNC server
1448 to provide authentication of the client when this is used. The path following
1449 this option specifies where the x509 certificates are to be loaded from.
1450 See the @ref{vnc_security} section for details on generating certificates.
1452 This option is now deprecated in favour of using the @option{tls-creds}
1453 argument.
1455 @item x509verify=@var{/path/to/certificate/dir}
1457 Valid if @option{tls} is specified. Require that x509 credentials are used
1458 for negotiating the TLS session. The server will send its x509 certificate
1459 to the client, and request that the client send its own x509 certificate.
1460 The server will validate the client's certificate against the CA certificate,
1461 and reject clients when validation fails. If the certificate authority is
1462 trusted, this is a sufficient authentication mechanism. You may still wish
1463 to set a password on the VNC server as a second authentication layer. The
1464 path following this option specifies where the x509 certificates are to
1465 be loaded from. See the @ref{vnc_security} section for details on generating
1466 certificates.
1468 This option is now deprecated in favour of using the @option{tls-creds}
1469 argument.
1471 @item sasl
1473 Require that the client use SASL to authenticate with the VNC server.
1474 The exact choice of authentication method used is controlled from the
1475 system / user's SASL configuration file for the 'qemu' service. This
1476 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1477 unprivileged user, an environment variable SASL_CONF_PATH can be used
1478 to make it search alternate locations for the service config.
1479 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1480 it is recommended that SASL always be combined with the 'tls' and
1481 'x509' settings to enable use of SSL and server certificates. This
1482 ensures a data encryption preventing compromise of authentication
1483 credentials. See the @ref{vnc_security} section for details on using
1484 SASL authentication.
1486 @item acl
1488 Turn on access control lists for checking of the x509 client certificate
1489 and SASL party. For x509 certs, the ACL check is made against the
1490 certificate's distinguished name. This is something that looks like
1491 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1492 made against the username, which depending on the SASL plugin, may
1493 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1494 When the @option{acl} flag is set, the initial access list will be
1495 empty, with a @code{deny} policy. Thus no one will be allowed to
1496 use the VNC server until the ACLs have been loaded. This can be
1497 achieved using the @code{acl} monitor command.
1499 @item lossy
1501 Enable lossy compression methods (gradient, JPEG, ...). If this
1502 option is set, VNC client may receive lossy framebuffer updates
1503 depending on its encoding settings. Enabling this option can save
1504 a lot of bandwidth at the expense of quality.
1506 @item non-adaptive
1508 Disable adaptive encodings. Adaptive encodings are enabled by default.
1509 An adaptive encoding will try to detect frequently updated screen regions,
1510 and send updates in these regions using a lossy encoding (like JPEG).
1511 This can be really helpful to save bandwidth when playing videos. Disabling
1512 adaptive encodings restores the original static behavior of encodings
1513 like Tight.
1515 @item share=[allow-exclusive|force-shared|ignore]
1517 Set display sharing policy. 'allow-exclusive' allows clients to ask
1518 for exclusive access. As suggested by the rfb spec this is
1519 implemented by dropping other connections. Connecting multiple
1520 clients in parallel requires all clients asking for a shared session
1521 (vncviewer: -shared switch). This is the default. 'force-shared'
1522 disables exclusive client access. Useful for shared desktop sessions,
1523 where you don't want someone forgetting specify -shared disconnect
1524 everybody else. 'ignore' completely ignores the shared flag and
1525 allows everybody connect unconditionally. Doesn't conform to the rfb
1526 spec but is traditional QEMU behavior.
1528 @item key-delay-ms
1530 Set keyboard delay, for key down and key up events, in milliseconds.
1531 Default is 1. Keyboards are low-bandwidth devices, so this slowdown
1532 can help the device and guest to keep up and not lose events in case
1533 events are arriving in bulk. Possible causes for the latter are flaky
1534 network connections, or scripts for automated testing.
1536 @end table
1537 ETEXI
1539 STEXI
1540 @end table
1541 ETEXI
1542 ARCHHEADING(, QEMU_ARCH_I386)
1544 ARCHHEADING(i386 target only, QEMU_ARCH_I386)
1545 STEXI
1546 @table @option
1547 ETEXI
1551 QEMU_ARCH_I386)
1552 STEXI
1553 @item -win2k-hack
1554 @findex -win2k-hack
1555 Use it when installing Windows 2000 to avoid a disk full bug. After
1556 Windows 2000 is installed, you no longer need this option (this option
1557 slows down the IDE transfers).
1558 ETEXI
1560 HXCOMM Deprecated by -rtc
1565 QEMU_ARCH_I386)
1566 STEXI
1567 @item -no-fd-bootchk
1568 @findex -no-fd-bootchk
1569 Disable boot signature checking for floppy disks in BIOS. May
1570 be needed to boot from old floppy disks.
1571 ETEXI
1575 STEXI
1576 @item -no-acpi
1577 @findex -no-acpi
1578 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1579 it if your guest OS complains about ACPI problems (PC target machine
1580 only).
1581 ETEXI
1585 STEXI
1586 @item -no-hpet
1587 @findex -no-hpet
1588 Disable HPET support.
1589 ETEXI
1592 "-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"
1594 STEXI
1595 @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}]...]
1596 @findex -acpitable
1597 Add ACPI table with specified header fields and context from specified files.
1598 For file=, take whole ACPI table from the specified files, including all
1599 ACPI headers (possible overridden by other options).
1600 For data=, only data
1601 portion of the table is used, all header information is specified in the
1602 command line.
1603 If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1604 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1605 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1606 spec.
1607 ETEXI
1630 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1631 STEXI
1632 @item -smbios file=@var{binary}
1633 @findex -smbios
1634 Load SMBIOS entry from binary file.
1636 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1637 Specify SMBIOS type 0 fields
1639 @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}]
1640 Specify SMBIOS type 1 fields
1642 @item -smbios type=2[,manufacturer=@var{str}][,product=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,location=@var{str}][,family=@var{str}]
1643 Specify SMBIOS type 2 fields
1645 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1646 Specify SMBIOS type 3 fields
1648 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1649 Specify SMBIOS type 4 fields
1651 @item -smbios type=17[,loc_pfx=@var{str}][,bank=@var{str}][,manufacturer=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,speed=@var{%d}]
1652 Specify SMBIOS type 17 fields
1653 ETEXI
1655 STEXI
1656 @end table
1657 ETEXI
1658 DEFHEADING()
1660 DEFHEADING(Network options)
1661 STEXI
1662 @table @option
1663 ETEXI
1665 HXCOMM Legacy slirp options (now moved to -net user):
1666 #ifdef CONFIG_SLIRP
1670 #ifndef _WIN32
1672 #endif
1673 #endif
1676 #ifdef CONFIG_SLIRP
1682 #ifndef _WIN32
1684 #endif
1687 #endif
1688 #ifdef _WIN32
1691 #else
1722 #endif
1723 #ifdef __linux__
1749 #endif
1759 #ifdef CONFIG_VDE
1765 #endif
1766 #ifdef CONFIG_NETMAP
1771 #endif
1785 #ifdef CONFIG_SLIRP
1787 #endif
1790 #ifdef CONFIG_VDE
1792 #endif
1793 #ifdef CONFIG_NETMAP
1795 #endif
1799 STEXI
1800 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1801 @findex -net
1802 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1803 = 0 is the default). The NIC is an e1000 by default on the PC
1804 target. Optionally, the MAC address can be changed to @var{mac}, the
1805 device address set to @var{addr} (PCI cards only),
1806 and a @var{name} can be assigned for use in monitor commands.
1807 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1808 that the card should have; this option currently only affects virtio cards; set
1809 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1810 NIC is created. QEMU can emulate several different models of network card.
1811 Valid values for @var{type} are
1812 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1813 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1814 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1815 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1816 for a list of available devices for your target.
1818 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1819 @findex -netdev
1820 @item -net user[,@var{option}][,@var{option}][,...]
1821 Use the user mode network stack which requires no administrator
1822 privilege to run. Valid options are:
1824 @table @option
1825 @item vlan=@var{n}
1826 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1828 @item id=@var{id}
1829 @itemx name=@var{name}
1830 Assign symbolic name for use in monitor commands.
1832 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
1833 be enabled. If neither is specified both protocols are enabled.
1835 @item net=@var{addr}[/@var{mask}]
1836 Set IP network address the guest will see. Optionally specify the netmask,
1837 either in the form a.b.c.d or as number of valid top-most bits. Default is
1838 10.0.2.0/24.
1840 @item host=@var{addr}
1841 Specify the guest-visible address of the host. Default is the 2nd IP in the
1842 guest network, i.e. x.x.x.2.
1844 @item ipv6-net=@var{addr}[/@var{int}]
1845 Set IPv6 network address the guest will see (default is fec0::/64). The
1846 network prefix is given in the usual hexadecimal IPv6 address
1847 notation. The prefix size is optional, and is given as the number of
1848 valid top-most bits (default is 64).
1850 @item ipv6-host=@var{addr}
1851 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
1852 the guest network, i.e. xxxx::2.
1854 @item restrict=on|off
1855 If this option is enabled, the guest will be isolated, i.e. it will not be
1856 able to contact the host and no guest IP packets will be routed over the host
1857 to the outside. This option does not affect any explicitly set forwarding rules.
1859 @item hostname=@var{name}
1860 Specifies the client hostname reported by the built-in DHCP server.
1862 @item dhcpstart=@var{addr}
1863 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1864 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1866 @item dns=@var{addr}
1867 Specify the guest-visible address of the virtual nameserver. The address must
1868 be different from the host address. Default is the 3rd IP in the guest network,
1869 i.e. x.x.x.3.
1871 @item ipv6-dns=@var{addr}
1872 Specify the guest-visible address of the IPv6 virtual nameserver. The address
1873 must be different from the host address. Default is the 3rd IP in the guest
1874 network, i.e. xxxx::3.
1876 @item dnssearch=@var{domain}
1877 Provides an entry for the domain-search list sent by the built-in
1878 DHCP server. More than one domain suffix can be transmitted by specifying
1879 this option multiple times. If supported, this will cause the guest to
1880 automatically try to append the given domain suffix(es) in case a domain name
1881 can not be resolved.
1883 Example:
1884 @example
1885 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1886 @end example
1888 @item tftp=@var{dir}
1889 When using the user mode network stack, activate a built-in TFTP
1890 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1891 The TFTP client on the guest must be configured in binary mode (use the command
1892 @code{bin} of the Unix TFTP client).
1894 @item bootfile=@var{file}
1895 When using the user mode network stack, broadcast @var{file} as the BOOTP
1896 filename. In conjunction with @option{tftp}, this can be used to network boot
1897 a guest from a local directory.
1899 Example (using pxelinux):
1900 @example
1901 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1902 @end example
1904 @item smb=@var{dir}[,smbserver=@var{addr}]
1905 When using the user mode network stack, activate a built-in SMB
1906 server so that Windows OSes can access to the host files in @file{@var{dir}}
1907 transparently. The IP address of the SMB server can be set to @var{addr}. By
1908 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1910 In the guest Windows OS, the line:
1911 @example
1912 10.0.2.4 smbserver
1913 @end example
1914 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1915 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1919 Note that a SAMBA server must be installed on the host OS.
1920 QEMU was tested successfully with smbd versions from Red Hat 9,
1921 Fedora Core 3 and OpenSUSE 11.x.
1923 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1924 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1925 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1926 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1927 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1928 be bound to a specific host interface. If no connection type is set, TCP is
1929 used. This option can be given multiple times.
1931 For example, to redirect host X11 connection from screen 1 to guest
1932 screen 0, use the following:
1934 @example
1935 # on the host
1936 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1937 # this host xterm should open in the guest X11 server
1938 xterm -display :1
1939 @end example
1941 To redirect telnet connections from host port 5555 to telnet port on
1942 the guest, use the following:
1944 @example
1945 # on the host
1946 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1947 telnet localhost 5555
1948 @end example
1950 Then when you use on the host @code{telnet localhost 5555}, you
1951 connect to the guest telnet server.
1953 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1954 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1955 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1956 to the character device @var{dev} or to a program executed by @var{cmd:command}
1957 which gets spawned for each connection. This option can be given multiple times.
1959 You can either use a chardev directly and have that one used throughout QEMU's
1960 lifetime, like in the following example:
1962 @example
1963 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1964 # the guest accesses it
1965 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1966 @end example
1968 Or you can execute a command on every TCP connection established by the guest,
1969 so that QEMU behaves similar to an inetd process for that virtual server:
1971 @example
1973 # and connect the TCP stream to its stdin/stdout
1974 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1975 @end example
1977 @end table
1979 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1980 processed and applied to -net user. Mixing them with the new configuration
1981 syntax gives undefined results. Their use for new applications is discouraged
1982 as they will be removed from future versions.
1984 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
1985 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
1986 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1988 Use the network script @var{file} to configure it and the network script
1989 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1990 automatically provides one. The default network configure script is
1991 @file{/etc/qemu-ifup} and the default network deconfigure script is
1992 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1993 to disable script execution.
1995 If running QEMU as an unprivileged user, use the network helper
1996 @var{helper} to configure the TAP interface and attach it to the bridge.
1997 The default network helper executable is @file{/path/to/qemu-bridge-helper}
1998 and the default bridge device is @file{br0}.
2000 @option{fd}=@var{h} can be used to specify the handle of an already
2001 opened host TAP interface.
2003 Examples:
2005 @example
2006 #launch a QEMU instance with the default network script
2007 qemu-system-i386 linux.img -net nic -net tap
2008 @end example
2010 @example
2011 #launch a QEMU instance with two NICs, each one connected
2012 #to a TAP device
2013 qemu-system-i386 linux.img \
2014 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
2015 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
2016 @end example
2018 @example
2019 #launch a QEMU instance with the default network helper to
2020 #connect a TAP device to bridge br0
2021 qemu-system-i386 linux.img \
2023 @end example
2025 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
2026 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
2027 Connect a host TAP network interface to a host bridge device.
2029 Use the network helper @var{helper} to configure the TAP interface and
2030 attach it to the bridge. The default network helper executable is
2031 @file{/path/to/qemu-bridge-helper} and the default bridge
2032 device is @file{br0}.
2034 Examples:
2036 @example
2037 #launch a QEMU instance with the default network helper to
2038 #connect a TAP device to bridge br0
2039 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
2040 @end example
2042 @example
2043 #launch a QEMU instance with the default network helper to
2044 #connect a TAP device to bridge qemubr0
2045 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
2046 @end example
2048 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2049 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
2051 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
2052 machine using a TCP socket connection. If @option{listen} is
2053 specified, QEMU waits for incoming connections on @var{port}
2054 (@var{host} is optional). @option{connect} is used to connect to
2055 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
2056 specifies an already opened TCP socket.
2058 Example:
2059 @example
2060 # launch a first QEMU instance
2061 qemu-system-i386 linux.img \
2062 -net nic,macaddr=52:54:00:12:34:56 \
2063 -net socket,listen=:1234
2064 # connect the VLAN 0 of this instance to the VLAN 0
2065 # of the first instance
2066 qemu-system-i386 linux.img \
2067 -net nic,macaddr=52:54:00:12:34:57 \
2068 -net socket,connect=127.0.0.1:1234
2069 @end example
2071 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2072 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
2074 Create a VLAN @var{n} shared with another QEMU virtual
2075 machines using a UDP multicast socket, effectively making a bus for
2076 every QEMU with same multicast address @var{maddr} and @var{port}.
2077 NOTES:
2078 @enumerate
2079 @item
2080 Several QEMU can be running on different hosts and share same bus (assuming
2081 correct multicast setup for these hosts).
2082 @item
2083 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
2084 @url{http://user-mode-linux.sf.net}.
2085 @item
2086 Use @option{fd=h} to specify an already opened UDP multicast socket.
2087 @end enumerate
2089 Example:
2090 @example
2091 # launch one QEMU instance
2092 qemu-system-i386 linux.img \
2093 -net nic,macaddr=52:54:00:12:34:56 \
2094 -net socket,mcast=230.0.0.1:1234
2096 qemu-system-i386 linux.img \
2097 -net nic,macaddr=52:54:00:12:34:57 \
2098 -net socket,mcast=230.0.0.1:1234
2100 qemu-system-i386 linux.img \
2101 -net nic,macaddr=52:54:00:12:34:58 \
2102 -net socket,mcast=230.0.0.1:1234
2103 @end example
2105 Example (User Mode Linux compat.):
2106 @example
2107 # launch QEMU instance (note mcast address selected
2108 # is UML's default)
2109 qemu-system-i386 linux.img \
2110 -net nic,macaddr=52:54:00:12:34:56 \
2111 -net socket,mcast=239.192.168.1:1102
2112 # launch UML
2113 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2114 @end example
2116 Example (send packets from host's 1.2.3.4):
2117 @example
2118 qemu-system-i386 linux.img \
2119 -net nic,macaddr=52:54:00:12:34:56 \
2120 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2121 @end example
2123 @item -netdev l2tpv3,id=@var{id},src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
2124 @itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
2125 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2126 protocol to transport Ethernet (and other Layer 2) data frames between
2127 two systems. It is present in routers, firewalls and the Linux kernel
2128 (from version 3.3 onwards).
2130 This transport allows a VM to communicate to another VM, router or firewall directly.
2132 @item src=@var{srcaddr}
2133 source address (mandatory)
2134 @item dst=@var{dstaddr}
2135 destination address (mandatory)
2136 @item udp
2137 select udp encapsulation (default is ip).
2138 @item srcport=@var{srcport}
2139 source udp port.
2140 @item dstport=@var{dstport}
2141 destination udp port.
2142 @item ipv6
2143 force v6, otherwise defaults to v4.
2144 @item rxcookie=@var{rxcookie}
2145 @itemx txcookie=@var{txcookie}
2146 Cookies are a weak form of security in the l2tpv3 specification.
2147 Their function is mostly to prevent misconfiguration. By default they are 32
2148 bit.
2149 @item cookie64
2150 Set cookie size to 64 bit instead of the default 32
2151 @item counter=off
2152 Force a 'cut-down' L2TPv3 with no counter as in
2153 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2154 @item pincounter=on
2155 Work around broken counter handling in peer. This may also help on
2156 networks which have packet reorder.
2157 @item offset=@var{offset}
2158 Add an extra offset between header and data
2160 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2161 on the remote Linux host 1.2.3.4:
2162 @example
2163 # Setup tunnel on linux host using raw ip as encapsulation
2164 # on 1.2.3.4
2165 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2166 encap udp udp_sport 16384 udp_dport 16384
2167 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2168 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2169 ifconfig vmtunnel0 mtu 1500
2170 ifconfig vmtunnel0 up
2171 brctl addif br-lan vmtunnel0
2174 # on 4.3.2.1
2175 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2177 qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
2180 @end example
2182 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2183 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2184 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2185 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2186 and MODE @var{octalmode} to change default ownership and permissions for
2187 communication port. This option is only available if QEMU has been compiled
2188 with vde support enabled.
2190 Example:
2191 @example
2192 # launch vde switch
2193 vde_switch -F -sock /tmp/myswitch
2194 # launch QEMU instance
2195 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2196 @end example
2198 @item -netdev hubport,id=@var{id},hubid=@var{hubid}
2203 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2204 required hub automatically.
2206 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2208 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2209 be a unix domain socket backed one. The vhost-user uses a specifically defined
2210 protocol to pass vhost ioctl replacement messages to an application on the other
2211 end of the socket. On non-MSIX guests, the feature can be forced with
2212 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2213 be created for multiqueue vhost-user.
2215 Example:
2216 @example
2217 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2218 -numa node,memdev=mem \
2219 -chardev socket,id=chr0,path=/path/to/socket \
2220 -netdev type=vhost-user,id=net0,chardev=chr0 \
2221 -device virtio-net-pci,netdev=net0
2222 @end example
2224 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2225 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2226 At most @var{len} bytes (64k by default) per packet are stored. The file format is
2227 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2228 Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2230 @item -net none
2231 Indicate that no network devices should be configured. It is used to
2232 override the default configuration (@option{-net nic -net user}) which
2233 is activated if no @option{-net} options are provided.
2234 ETEXI
2236 STEXI
2237 @end table
2238 ETEXI
2239 DEFHEADING()
2241 DEFHEADING(Character device options)
2242 STEXI
2244 The general form of a character device option is:
2245 @table @option
2246 ETEXI
2251 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2265 #ifdef _WIN32
2268 #else
2271 #endif
2272 #ifdef CONFIG_BRLAPI
2274 #endif
2275 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2276 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2279 #endif
2280 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2283 #endif
2284 #if defined(CONFIG_SPICE)
2287 #endif
2288 , QEMU_ARCH_ALL
2289 )
2291 STEXI
2292 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2293 @findex -chardev
2294 Backend is one of:
2295 @option{null},
2296 @option{socket},
2297 @option{udp},
2298 @option{msmouse},
2299 @option{vc},
2300 @option{ringbuf},
2301 @option{file},
2302 @option{pipe},
2303 @option{console},
2304 @option{serial},
2305 @option{pty},
2306 @option{stdio},
2307 @option{braille},
2308 @option{tty},
2309 @option{parallel},
2310 @option{parport},
2311 @option{spicevmc}.
2312 @option{spiceport}.
2313 The specific backend will determine the applicable options.
2317 All devices must have an id, which can be any string up to 127 characters long.
2318 It is used to uniquely identify this device in other command line directives.
2320 A character device may be used in multiplexing mode by multiple front-ends.
2321 Specify @option{mux=on} to enable this mode.
2324 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2325 create a multiplexer with your specified ID, and you can then configure multiple
2326 front ends to use that chardev ID for their input/output. Up to four different
2327 front ends can be connected to a single multiplexed chardev. (Without
2328 multiplexing enabled, a chardev can only be used by a single front end.)
2329 For instance you could use this to allow a single stdio chardev to be used by
2330 two serial ports and the QEMU monitor:
2332 @example
2333 -chardev stdio,mux=on,id=char0 \
2334 -mon chardev=char0,mode=readline \
2335 -serial chardev:char0 \
2336 -serial chardev:char0
2337 @end example
2339 You can have more than one multiplexer in a system configuration; for instance
2340 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2341 multiplexed between the QEMU monitor and a parallel port:
2343 @example
2344 -chardev stdio,mux=on,id=char0 \
2345 -mon chardev=char0,mode=readline \
2346 -parallel chardev:char0 \
2347 -chardev tcp,...,mux=on,id=char1 \
2348 -serial chardev:char1 \
2349 -serial chardev:char1
2350 @end example
2352 When you're using a multiplexed character device, some escape sequences are
2353 interpreted in the input. @xref{mux_keys, Keys in the character backend
2354 multiplexer}.
2356 Note that some other command line options may implicitly create multiplexed
2357 character backends; for instance @option{-serial mon:stdio} creates a
2358 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2359 and @option{-nographic} also multiplexes the console and the monitor to
2360 stdio.
2362 There is currently no support for multiplexing in the other direction
2363 (where a single QEMU front end takes input and output from multiple chardevs).
2365 Every backend supports the @option{logfile} option, which supplies the path
2366 to a file to record all data transmitted via the backend. The @option{logappend}
2367 option controls whether the log file will be truncated or appended to when
2368 opened.
2370 Further options to each backend are described below.
2372 @item -chardev null ,id=@var{id}
2373 A void device. This device will not emit any data, and will drop any data it
2374 receives. The null backend does not take any options.
2376 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2378 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2379 unix socket will be created if @option{path} is specified. Behaviour is
2380 undefined if TCP options are specified for a unix socket.
2382 @option{server} specifies that the socket shall be a listening socket.
2384 @option{nowait} specifies that QEMU should not block waiting for a client to
2385 connect to a listening socket.
2387 @option{telnet} specifies that traffic on the socket should interpret telnet
2388 escape sequences.
2390 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2391 the remote end goes away. qemu will delay this many seconds and then attempt
2392 to reconnect. Zero disables reconnecting, and is the default.
2394 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2395 and specifies the id of the TLS credentials to use for the handshake. The
2396 credentials must be previously created with the @option{-object tls-creds}
2397 argument.
2399 TCP and unix socket options are given below:
2401 @table @option
2403 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2405 @option{host} for a listening socket specifies the local address to be bound.
2406 For a connecting socket species the remote host to connect to. @option{host} is
2407 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2409 @option{port} for a listening socket specifies the local port to be bound. For a
2410 connecting socket specifies the port on the remote host to connect to.
2411 @option{port} can be given as either a port number or a service name.
2412 @option{port} is required.
2414 @option{to} is only relevant to listening sockets. If it is specified, and
2415 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2416 to and including @option{to} until it succeeds. @option{to} must be specified
2417 as a port number.
2419 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2420 If neither is specified the socket may use either protocol.
2422 @option{nodelay} disables the Nagle algorithm.
2424 @item unix options: path=@var{path}
2426 @option{path} specifies the local path of the unix socket. @option{path} is
2427 required.
2429 @end table
2431 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2433 Sends all traffic from the guest to a remote host over UDP.
2435 @option{host} specifies the remote host to connect to. If not specified it
2436 defaults to @code{localhost}.
2438 @option{port} specifies the port on the remote host to connect to. @option{port}
2439 is required.
2441 @option{localaddr} specifies the local address to bind to. If not specified it
2442 defaults to @code{0.0.0.0}.
2444 @option{localport} specifies the local port to bind to. If not specified any
2445 available local port will be used.
2447 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2448 If neither is specified the device may use either protocol.
2450 @item -chardev msmouse ,id=@var{id}
2452 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2453 take any options.
2455 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2457 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2458 size.
2460 @option{width} and @option{height} specify the width and height respectively of
2461 the console, in pixels.
2463 @option{cols} and @option{rows} specify that the console be sized to fit a text
2464 console with the given dimensions.
2466 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2468 Create a ring buffer with fixed size @option{size}.
2469 @var{size} must be a power of two and defaults to @code{64K}.
2471 @item -chardev file ,id=@var{id} ,path=@var{path}
2473 Log all traffic received from the guest to a file.
2475 @option{path} specifies the path of the file to be opened. This file will be
2476 created if it does not already exist, and overwritten if it does. @option{path}
2477 is required.
2479 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2481 Create a two-way connection to the guest. The behaviour differs slightly between
2482 Windows hosts and other hosts:
2484 On Windows, a single duplex pipe will be created at
2487 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2488 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2489 received by the guest. Data written by the guest can be read from
2490 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2491 be present.
2493 @option{path} forms part of the pipe path as described above. @option{path} is
2494 required.
2496 @item -chardev console ,id=@var{id}
2498 Send traffic from the guest to QEMU's standard output. @option{console} does not
2499 take any options.
2501 @option{console} is only available on Windows hosts.
2503 @item -chardev serial ,id=@var{id} ,path=@option{path}
2505 Send traffic from the guest to a serial device on the host.
2507 On Unix hosts serial will actually accept any tty device,
2508 not only serial lines.
2510 @option{path} specifies the name of the serial device to open.
2512 @item -chardev pty ,id=@var{id}
2514 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2515 not take any options.
2517 @option{pty} is not available on Windows hosts.
2519 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2520 Connect to standard input and standard output of the QEMU process.
2522 @option{signal} controls if signals are enabled on the terminal, that includes
2523 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2524 default, use @option{signal=off} to disable it.
2526 @item -chardev braille ,id=@var{id}
2528 Connect to a local BrlAPI server. @option{braille} does not take any options.
2530 @item -chardev tty ,id=@var{id} ,path=@var{path}
2532 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2533 DragonFlyBSD hosts. It is an alias for @option{serial}.
2535 @option{path} specifies the path to the tty. @option{path} is required.
2537 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2538 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2540 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2542 Connect to a local parallel port.
2544 @option{path} specifies the path to the parallel port device. @option{path} is
2545 required.
2547 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2549 @option{spicevmc} is only available when spice support is built in.
2551 @option{debug} debug level for spicevmc
2553 @option{name} name of spice channel to connect to
2555 Connect to a spice virtual machine channel, such as vdiport.
2557 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2559 @option{spiceport} is only available when spice support is built in.
2561 @option{debug} debug level for spicevmc
2563 @option{name} name of spice port to connect to
2565 Connect to a spice port, allowing a Spice client to handle the traffic
2566 identified by a name (preferably a fqdn).
2567 ETEXI
2569 STEXI
2570 @end table
2571 ETEXI
2572 DEFHEADING()
2574 DEFHEADING(Device URL Syntax)
2575 STEXI
2577 In addition to using normal file images for the emulated storage devices,
2578 QEMU can also use networked resources such as iSCSI devices. These are
2579 specified using a special URL syntax.
2581 @table @option
2582 @item iSCSI
2583 iSCSI support allows QEMU to access iSCSI resources directly and use as
2584 images for the guest storage. Both disk and cdrom images are supported.
2586 Syntax for specifying iSCSI LUNs is
2587 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2589 By default qemu will use the iSCSI initiator-name
2590 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2591 line or a configuration file.
2593 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2594 stalled requests and force a reestablishment of the session. The timeout
2595 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2596 1.15.0 or greater is required for this feature.
2598 Example (without authentication):
2599 @example
2600 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2601 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2602 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2603 @end example
2605 Example (CHAP username/password via URL):
2606 @example
2607 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2608 @end example
2610 Example (CHAP username/password via environment variables):
2611 @example
2614 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2615 @end example
2617 iSCSI support is an optional feature of QEMU and only available when
2618 compiled and linked against libiscsi.
2619 ETEXI
2626 STEXI
2628 iSCSI parameters such as username and password can also be specified via
2629 a configuration file. See qemu-doc for more information and examples.
2631 @item NBD
2632 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2633 as Unix Domain Sockets.
2635 Syntax for specifying a NBD device using TCP
2636 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2638 Syntax for specifying a NBD device using Unix Domain Sockets
2639 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2642 Example for TCP
2643 @example
2644 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2645 @end example
2647 Example for Unix Domain Sockets
2648 @example
2649 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2650 @end example
2652 @item SSH
2653 QEMU supports SSH (Secure Shell) access to remote disks.
2655 Examples:
2656 @example
2657 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2658 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2659 @end example
2661 Currently authentication must be done using ssh-agent. Other
2662 authentication methods may be supported in future.
2664 @item Sheepdog
2665 Sheepdog is a distributed storage system for QEMU.
2666 QEMU supports using either local sheepdog devices or remote networked
2667 devices.
2669 Syntax for specifying a sheepdog device
2670 @example
2671 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2672 @end example
2674 Example
2675 @example
2676 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2677 @end example
2679 See also @url{https://sheepdog.github.io/sheepdog/}.
2681 @item GlusterFS
2682 GlusterFS is a user space distributed file system.
2683 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2684 TCP, Unix Domain Sockets and RDMA transport protocols.
2686 Syntax for specifying a VM disk image on GlusterFS volume is
2687 @example
2689 URI:
2690 gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
2692 JSON:
2693 'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
2696 @end example
2699 Example
2700 @example
2701 URI:
2702 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
2703 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log
2705 JSON:
2712 qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
2713 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log,
2714 @ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
2715 @ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
2716 @end example
2718 See also @url{http://www.gluster.org}.
2720 @item HTTP/HTTPS/FTP/FTPS
2721 QEMU supports read-only access to files accessed over http(s) and ftp(s).
2723 Syntax using a single filename:
2724 @example
2725 <protocol>://[<username>[:<password>]@@]<host>/<path>
2726 @end example
2728 where:
2729 @table @option
2730 @item protocol
2731 'http', 'https', 'ftp', or 'ftps'.
2733 @item username
2734 Optional username for authentication to the remote server.
2736 @item password
2737 Optional password for authentication to the remote server.
2739 @item host
2740 Address of the remote server.
2742 @item path
2743 Path on the remote server, including any query string.
2744 @end table
2746 The following options are also supported:
2747 @table @option
2748 @item url
2749 The full URL when passing options to the driver explicitly.
2751 @item readahead
2752 The amount of data to read ahead with each range request to the remote server.
2753 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2754 does not have a suffix, it will be assumed to be in bytes. The value must be a
2755 multiple of 512 bytes. It defaults to 256k.
2757 @item sslverify
2758 Whether to verify the remote server's certificate when connecting over SSL. It
2759 can have the value 'on' or 'off'. It defaults to 'on'.
2761 @item cookie
2762 Send this cookie (it can also be a list of cookies separated by ';') with
2763 each outgoing request. Only supported when using protocols such as HTTP
2764 which support cookies, otherwise ignored.
2766 @item timeout
2767 Set the timeout in seconds of the CURL connection. This timeout is the time
2768 that CURL waits for a response from the remote server to get the size of the
2769 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2770 @end table
2772 Note that when passing options to qemu explicitly, @option{driver} is the value
2773 of <protocol>.
2775 Example: boot from a remote Fedora 20 live ISO image
2776 @example
2777 qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2779 qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
2780 @end example
2782 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2783 writes, copy-on-read, and a readahead of 64k
2784 @example
2785 qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"@}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
2788 @end example
2793 @example
2794 qemu-img create -f qcow2 -o backing_file='json:@{"file.driver":"https",, "file.url":"https://user:password@@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10@}' /tmp/test.qcow2
2797 @end example
2798 ETEXI
2800 STEXI
2801 @end table
2802 ETEXI
2805 STEXI
2806 @table @option
2807 ETEXI
2819 QEMU_ARCH_ALL)
2820 STEXI
2822 @findex -bt
2825 example when emulating a machine with only one HCI built into it, only
2827 logic. The Transport Layer is decided by the machine type. Currently
2828 the machines @code{n800} and @code{n810} have one HCI and all other
2829 machines have none.
2831 @anchor{bt-hcis}
2832 The following three types are recognized:
2834 @table @option
2835 @item -bt hci,null
2836 (default) The corresponding Bluetooth HCI assumes no internal logic
2837 and will not respond to any HCI commands or emit events.
2839 @item -bt hci,host[:@var{id}]
2840 (@code{bluez} only) The corresponding HCI passes commands / events
2841 to / from the physical HCI identified by the name @var{id} (default:
2842 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2843 capable systems like Linux.
2845 @item -bt hci[,vlan=@var{n}]
2846 Add a virtual, standard HCI that will participate in the Bluetooth
2847 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2848 VLANs, devices inside a bluetooth network @var{n} can only communicate
2849 with other devices in the same network (scatternet).
2850 @end table
2852 @item -bt vhci[,vlan=@var{n}]
2853 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2854 to the host bluetooth stack instead of to the emulated target. This
2855 allows the host and target machines to participate in a common scatternet
2856 and communicate. Requires the Linux @code{vhci} driver installed. Can
2857 be used as following:
2859 @example
2860 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2861 @end example
2863 @item -bt device:@var{dev}[,vlan=@var{n}]
2864 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2865 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2866 currently:
2868 @table @option
2869 @item keyboard
2870 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2871 @end table
2872 ETEXI
2874 STEXI
2875 @end table
2876 ETEXI
2877 DEFHEADING()
2879 #ifdef CONFIG_TPM
2880 DEFHEADING(TPM device options)
2882 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2887 QEMU_ARCH_ALL)
2888 STEXI
2890 The general form of a TPM device option is:
2891 @table @option
2893 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
2894 @findex -tpmdev
2895 Backend type must be:
2896 @option{passthrough}.
2898 The specific backend type will determine the applicable options.
2899 The @code{-tpmdev} option creates the TPM backend and requires a
2900 @code{-device} option that specifies the TPM frontend interface model.
2902 Options to each backend are described below.
2904 Use 'help' to print all available TPM backend types.
2905 @example
2906 qemu -tpmdev help
2907 @end example
2909 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
2911 (Linux-host only) Enable access to the host's TPM using the passthrough
2912 driver.
2914 @option{path} specifies the path to the host's TPM device, i.e., on
2915 a Linux host this would be @code{/dev/tpm0}.
2916 @option{path} is optional and by default @code{/dev/tpm0} is used.
2918 @option{cancel-path} specifies the path to the host TPM device's sysfs
2919 entry allowing for cancellation of an ongoing TPM command.
2920 @option{cancel-path} is optional and by default QEMU will search for the
2921 sysfs entry to use.
2923 Some notes about using the host's TPM with the passthrough driver:
2925 The TPM device accessed by the passthrough driver must not be
2926 used by any other application on the host.
2928 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2929 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2930 TPM again and may therefore not show a TPM-specific menu that would
2931 otherwise allow the user to configure the TPM, e.g., allow the user to
2932 enable/disable or activate/deactivate the TPM.
2933 Further, if TPM ownership is released from within a VM then the host's TPM
2934 will get disabled and deactivated. To enable and activate the
2935 TPM again afterwards, the host has to be rebooted and the user is
2936 required to enter the firmware's menu to enable and activate the TPM.
2937 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2939 To create a passthrough TPM use the following two options:
2940 @example
2941 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2942 @end example
2943 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2944 @code{tpmdev=tpm0} in the device option.
2946 @end table
2948 ETEXI
2950 DEFHEADING()
2952 #endif
2954 DEFHEADING(Linux/Multiboot boot specific)
2955 STEXI
2957 When using these options, you can use a given Linux or Multiboot
2958 kernel without installing it in the disk image. It can be useful
2959 for easier testing of various kernels.
2961 @table @option
2962 ETEXI
2966 STEXI
2967 @item -kernel @var{bzImage}
2968 @findex -kernel
2969 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2970 or in multiboot format.
2971 ETEXI
2975 STEXI
2976 @item -append @var{cmdline}
2977 @findex -append
2978 Use @var{cmdline} as kernel command line
2979 ETEXI
2983 STEXI
2984 @item -initrd @var{file}
2985 @findex -initrd
2986 Use @var{file} as initial ram disk.
2990 This syntax is only available with multiboot.
2992 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2993 first module.
2994 ETEXI
2998 STEXI
2999 @item -dtb @var{file}
3000 @findex -dtb
3001 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
3002 on boot.
3003 ETEXI
3005 STEXI
3006 @end table
3007 ETEXI
3008 DEFHEADING()
3010 DEFHEADING(Debug/Expert options)
3011 STEXI
3012 @table @option
3013 ETEXI
3020 QEMU_ARCH_ALL)
3021 STEXI
3023 @item -fw_cfg [name=]@var{name},file=@var{file}
3024 @findex -fw_cfg
3025 Add named fw_cfg entry with contents from file @var{file}.
3027 @item -fw_cfg [name=]@var{name},string=@var{str}
3028 Add named fw_cfg entry with contents from string @var{str}.
3030 The terminating NUL character of the contents of @var{str} will not be
3031 included as part of the fw_cfg item data. To insert contents with
3032 embedded NUL characters, you have to use the @var{file} parameter.
3034 The fw_cfg entries are passed by QEMU through to the guest.
3036 Example:
3037 @example
3038 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3039 @end example
3040 creates an fw_cfg entry named opt/com.mycompany/blob with contents
3041 from ./my_blob.bin.
3043 ETEXI
3047 QEMU_ARCH_ALL)
3048 STEXI
3049 @item -serial @var{dev}
3050 @findex -serial
3051 Redirect the virtual serial port to host character device
3052 @var{dev}. The default device is @code{vc} in graphical mode and
3053 @code{stdio} in non graphical mode.
3055 This option can be used several times to simulate up to 4 serial
3056 ports.
3058 Use @code{-serial none} to disable all serial ports.
3060 Available character devices are:
3061 @table @option
3062 @item vc[:@var{W}x@var{H}]
3063 Virtual console. Optionally, a width and height can be given in pixel with
3064 @example
3065 vc:800x600
3066 @end example
3067 It is also possible to specify width or height in characters:
3068 @example
3069 vc:80Cx24C
3070 @end example
3071 @item pty
3072 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3073 @item none
3074 No device is allocated.
3075 @item null
3076 void device
3077 @item chardev:@var{id}
3078 Use a named character device defined with the @code{-chardev} option.
3079 @item /dev/XXX
3080 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
3081 parameters are set according to the emulated ones.
3082 @item /dev/parport@var{N}
3083 [Linux only, parallel port only] Use host parallel port
3084 @var{N}. Currently SPP and EPP parallel port features can be used.
3085 @item file:@var{filename}
3086 Write output to @var{filename}. No character can be read.
3087 @item stdio
3088 [Unix only] standard input/output
3089 @item pipe:@var{filename}
3090 name pipe @var{filename}
3091 @item COM@var{n}
3092 [Windows only] Use host serial port @var{n}
3093 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3094 This implements UDP Net Console.
3095 When @var{remote_host} or @var{src_ip} are not specified
3096 they default to @code{0.0.0.0}.
3097 When not using a specified @var{src_port} a random port is automatically chosen.
3099 If you just want a simple readonly console you can use @code{netcat} or
3100 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3101 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3102 will appear in the netconsole session.
3104 If you plan to send characters back via netconsole or you want to stop
3105 and start QEMU a lot of times, you should have QEMU use the same
3106 source port each time by using something like @code{-serial
3107 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3108 version of netcat which can listen to a TCP port and send and receive
3109 characters via udp. If you have a patched version of netcat which
3110 activates telnet remote echo and single char transfer, then you can
3111 use the following options to set up a netcat redirector to allow
3112 telnet on port 5555 to access the QEMU port.
3113 @table @code
3114 @item QEMU Options:
3115 -serial udp::4555@@:4556
3116 @item netcat options:
3117 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3118 @item telnet options:
3119 localhost 5555
3120 @end table
3122 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3123 The TCP Net Console has two modes of operation. It can send the serial
3124 I/O to a location or wait for a connection from a location. By default
3125 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3126 the @var{server} option QEMU will wait for a client socket application
3127 to connect to the port before continuing, unless the @code{nowait}
3128 option was specified. The @code{nodelay} option disables the Nagle buffering
3129 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3130 set, if the connection goes down it will attempt to reconnect at the
3131 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3132 one TCP connection at a time is accepted. You can use @code{telnet} to
3133 connect to the corresponding character device.
3134 @table @code
3135 @item Example to send tcp console to 192.168.0.2 port 4444
3136 -serial tcp:192.168.0.2:4444
3137 @item Example to listen and wait on port 4444 for connection
3138 -serial tcp::4444,server
3139 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3140 -serial tcp:192.168.0.100:4444,server,nowait
3141 @end table
3143 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3144 The telnet protocol is used instead of raw tcp sockets. The options
3145 work the same as if you had specified @code{-serial tcp}. The
3146 difference is that the port acts like a telnet server or client using
3147 telnet option negotiation. This will also allow you to send the
3148 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3149 sequence. Typically in unix telnet you do it with Control-] and then
3152 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3153 A unix domain socket is used instead of a tcp socket. The option works the
3154 same as if you had specified @code{-serial tcp} except the unix domain socket
3155 @var{path} is used for connections.
3157 @item mon:@var{dev_string}
3158 This is a special option to allow the monitor to be multiplexed onto
3159 another serial port. The monitor is accessed with key sequence of
3160 @key{Control-a} and then pressing @key{c}.
3161 @var{dev_string} should be any one of the serial devices specified
3162 above. An example to multiplex the monitor onto a telnet server
3163 listening on port 4444 would be:
3164 @table @code
3165 @item -serial mon:telnet::4444,server,nowait
3166 @end table
3167 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3168 QEMU any more but will be passed to the guest instead.
3170 @item braille
3171 Braille device. This will use BrlAPI to display the braille output on a real
3172 or fake device.
3174 @item msmouse
3175 Three button serial mouse. Configure the guest to use Microsoft protocol.
3176 @end table
3177 ETEXI
3181 QEMU_ARCH_ALL)
3182 STEXI
3183 @item -parallel @var{dev}
3184 @findex -parallel
3185 Redirect the virtual parallel port to host device @var{dev} (same
3186 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3187 be used to use hardware devices connected on the corresponding host
3188 parallel port.
3190 This option can be used several times to simulate up to 3 parallel
3191 ports.
3193 Use @code{-parallel none} to disable all parallel ports.
3194 ETEXI
3198 QEMU_ARCH_ALL)
3199 STEXI
3200 @item -monitor @var{dev}
3201 @findex -monitor
3202 Redirect the monitor to host device @var{dev} (same devices as the
3203 serial port).
3204 The default device is @code{vc} in graphical mode and @code{stdio} in
3205 non graphical mode.
3206 Use @code{-monitor none} to disable the default monitor.
3207 ETEXI
3210 QEMU_ARCH_ALL)
3211 STEXI
3212 @item -qmp @var{dev}
3213 @findex -qmp
3214 Like -monitor but opens in 'control' mode.
3215 ETEXI
3218 QEMU_ARCH_ALL)
3219 STEXI
3220 @item -qmp-pretty @var{dev}
3221 @findex -qmp-pretty
3222 Like -qmp but uses pretty JSON formatting.
3223 ETEXI
3227 STEXI
3228 @item -mon [chardev=]name[,mode=readline|control]
3229 @findex -mon
3230 Setup monitor on chardev @var{name}.
3231 ETEXI
3235 QEMU_ARCH_ALL)
3236 STEXI
3237 @item -debugcon @var{dev}
3238 @findex -debugcon
3239 Redirect the debug console to host device @var{dev} (same devices as the
3240 serial port). The debug console is an I/O port which is typically port
3241 0xe9; writing to that I/O port sends output to this device.
3242 The default device is @code{vc} in graphical mode and @code{stdio} in
3243 non graphical mode.
3244 ETEXI
3248 STEXI
3249 @item -pidfile @var{file}
3250 @findex -pidfile
3251 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3252 from a script.
3253 ETEXI
3257 STEXI
3258 @item -singlestep
3259 @findex -singlestep
3260 Run the emulation in single step mode.
3261 ETEXI
3265 QEMU_ARCH_ALL)
3266 STEXI
3267 @item -S
3268 @findex -S
3269 Do not start CPU at startup (you must type 'c' in the monitor).
3270 ETEXI
3276 QEMU_ARCH_ALL)
3277 STEXI
3278 @item -realtime mlock=on|off
3279 @findex -realtime
3280 Run qemu with realtime features.
3281 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3282 (enabled by default).
3283 ETEXI
3287 STEXI
3288 @item -gdb @var{dev}
3289 @findex -gdb
3290 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3291 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3292 stdio are reasonable use case. The latter is allowing to start QEMU from
3293 within gdb and establish the connection via a pipe:
3294 @example
3295 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3296 @end example
3297 ETEXI
3301 QEMU_ARCH_ALL)
3302 STEXI
3303 @item -s
3304 @findex -s
3305 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3306 (@pxref{gdb_usage}).
3307 ETEXI
3311 QEMU_ARCH_ALL)
3312 STEXI
3313 @item -d @var{item1}[,...]
3314 @findex -d
3315 Enable logging of specified items. Use '-d help' for a list of log items.
3316 ETEXI
3320 QEMU_ARCH_ALL)
3321 STEXI
3322 @item -D @var{logfile}
3323 @findex -D
3324 Output log in @var{logfile} instead of to stderr
3325 ETEXI
3328 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3329 QEMU_ARCH_ALL)
3330 STEXI
3331 @item -dfilter @var{range1}[,...]
3332 @findex -dfilter
3333 Filter debug output to that relevant to a range of target addresses. The filter
3334 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3335 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3336 addresses and sizes required. For example:
3337 @example
3338 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3339 @end example
3340 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3341 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3342 block starting at 0xffffffc00005f000.
3343 ETEXI
3347 QEMU_ARCH_ALL)
3348 STEXI
3349 @item -L @var{path}
3350 @findex -L
3351 Set the directory for the BIOS, VGA BIOS and keymaps.
3353 To list all the data directories, use @code{-L help}.
3354 ETEXI
3358 STEXI
3359 @item -bios @var{file}
3360 @findex -bios
3361 Set the filename for the BIOS.
3362 ETEXI
3366 STEXI
3367 @item -enable-kvm
3368 @findex -enable-kvm
3369 Enable KVM full virtualization support. This option is only available
3370 if KVM support is enabled when compiling.
3371 ETEXI
3375 STEXI
3376 @item -enable-hax
3377 @findex -enable-hax
3378 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3379 is only available if HAX support is enabled when compiling. HAX is only
3380 applicable to MAC and Windows platform, and thus does not conflict with
3381 KVM.
3382 ETEXI
3389 QEMU_ARCH_ALL)
3393 QEMU_ARCH_ALL)
3398 QEMU_ARCH_ALL)
3399 STEXI
3400 @item -xen-domid @var{id}
3401 @findex -xen-domid
3402 Specify xen guest domain @var{id} (XEN only).
3403 @item -xen-create
3404 @findex -xen-create
3405 Create domain using xen hypercalls, bypassing xend.
3406 Warning: should not be used when xend is in use (XEN only).
3407 @item -xen-attach
3408 @findex -xen-attach
3409 Attach to existing xen domain.
3410 xend will use this when starting QEMU (XEN only).
3411 @findex -xen-domid-restrict
3412 Restrict set of available xen operations to specified domain id (XEN only).
3413 ETEXI
3417 STEXI
3418 @item -no-reboot
3419 @findex -no-reboot
3420 Exit instead of rebooting.
3421 ETEXI
3425 STEXI
3426 @item -no-shutdown
3427 @findex -no-shutdown
3428 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3429 This allows for instance switching to monitor to commit changes to the
3430 disk image.
3431 ETEXI
3436 QEMU_ARCH_ALL)
3437 STEXI
3438 @item -loadvm @var{file}
3439 @findex -loadvm
3440 Start right away with a saved state (@code{loadvm} in monitor)
3441 ETEXI
3443 #ifndef _WIN32
3446 #endif
3447 STEXI
3448 @item -daemonize
3449 @findex -daemonize
3450 Daemonize the QEMU process after initialization. QEMU will not detach from
3451 standard IO until it is ready to receive connections on any of its devices.
3452 This option is a useful way for external programs to launch QEMU without having
3453 to cope with initialization race conditions.
3454 ETEXI
3458 QEMU_ARCH_ALL)
3459 STEXI
3460 @item -option-rom @var{file}
3461 @findex -option-rom
3462 Load the contents of @var{file} as an option ROM.
3463 This option is useful to load things like EtherBoot.
3464 ETEXI
3466 HXCOMM Silently ignored for compatibility
3469 HXCOMM Options deprecated by -rtc
3476 QEMU_ARCH_ALL)
3478 STEXI
3480 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3481 @findex -rtc
3482 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3483 UTC or local time, respectively. @code{localtime} is required for correct date in
3484 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3485 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3487 By default the RTC is driven by the host system time. This allows using of the
3488 RTC as accurate reference clock inside the guest, specifically if the host
3489 time is smoothly following an accurate external reference clock, e.g. via NTP.
3490 If you want to isolate the guest time from the host, you can set @option{clock}
3491 to @code{rt} instead. To even prevent it from progressing during suspension,
3492 you can set it to @code{vm}.
3494 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3495 specifically with Windows' ACPI HAL. This option will try to figure out how
3496 many timer interrupts were not processed by the Windows guest and will
3497 re-inject them.
3498 ETEXI
3501 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3505 STEXI
3506 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3507 @findex -icount
3508 Enable virtual instruction counter. The virtual cpu will execute one
3509 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3510 then the virtual cpu speed will be automatically adjusted to keep virtual
3511 time within a few seconds of real time.
3513 When the virtual cpu is sleeping, the virtual time will advance at default
3514 speed unless @option{sleep=on|off} is specified.
3515 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3516 instantly whenever the virtual cpu goes to sleep mode and will not advance
3517 if no timer is enabled. This behavior give deterministic execution times from
3518 the guest point of view.
3520 Note that while this option can give deterministic behavior, it does not
3521 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3522 order cores with complex cache hierarchies. The number of instructions
3523 executed often has little or no correlation with actual performance.
3525 @option{align=on} will activate the delay algorithm which will try
3526 to synchronise the host clock and the virtual clock. The goal is to
3527 have a guest running at the real frequency imposed by the shift option.
3528 Whenever the guest clock is behind the host clock and if
3529 @option{align=on} is specified then we print a message to the user
3530 to inform about the delay.
3531 Currently this option does not work when @option{shift} is @code{auto}.
3532 Note: The sync algorithm will work for those shift values for which
3533 the guest clock runs ahead of the host clock. Typically this happens
3534 when the shift value is high (how high depends on the host machine).
3536 When @option{rr} option is specified deterministic record/replay is enabled.
3537 Replay log is written into @var{filename} file in record mode and
3538 read from this file in replay mode.
3540 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3541 at the start of execution recording. In replay mode this option is used
3542 to load the initial VM state.
3543 ETEXI
3548 QEMU_ARCH_ALL)
3549 STEXI
3550 @item -watchdog @var{model}
3551 @findex -watchdog
3552 Create a virtual hardware watchdog device. Once enabled (by a guest
3553 action), the watchdog must be periodically polled by an agent inside
3554 the guest or else the guest will be restarted. Choose a model for
3555 which your guest has drivers.
3557 The @var{model} is the model of hardware watchdog to emulate. Use
3558 @code{-watchdog help} to list available hardware models. Only one
3559 watchdog can be enabled for a guest.
3561 The following models may be available:
3562 @table @option
3563 @item ib700
3564 iBASE 700 is a very simple ISA watchdog with a single timer.
3565 @item i6300esb
3566 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3567 dual-timer watchdog.
3568 @item diag288
3569 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3570 (currently KVM only).
3571 @end table
3572 ETEXI
3577 QEMU_ARCH_ALL)
3578 STEXI
3579 @item -watchdog-action @var{action}
3580 @findex -watchdog-action
3582 The @var{action} controls what QEMU will do when the watchdog timer
3583 expires.
3584 The default is
3585 @code{reset} (forcefully reset the guest).
3586 Other possible actions are:
3587 @code{shutdown} (attempt to gracefully shutdown the guest),
3588 @code{poweroff} (forcefully poweroff the guest),
3589 @code{pause} (pause the guest),
3590 @code{debug} (print a debug message and continue), or
3591 @code{none} (do nothing).
3593 Note that the @code{shutdown} action requires that the guest responds
3594 to ACPI signals, which it may not be able to do in the sort of
3595 situations where the watchdog would have expired, and thus
3596 @code{-watchdog-action shutdown} is not recommended for production use.
3598 Examples:
3600 @table @code
3601 @item -watchdog i6300esb -watchdog-action pause
3602 @itemx -watchdog ib700
3603 @end table
3604 ETEXI
3608 QEMU_ARCH_ALL)
3609 STEXI
3611 @item -echr @var{numeric_ascii_value}
3612 @findex -echr
3613 Change the escape character used for switching to the monitor when using
3614 monitor and serial sharing. The default is @code{0x01} when using the
3615 @code{-nographic} option. @code{0x01} is equal to pressing
3616 @code{Control-a}. You can select a different character from the ascii
3617 control keys where 1 through 26 map to Control-a through Control-z. For
3618 instance you could use the either of the following to change the escape
3619 character to Control-t.
3620 @table @code
3621 @item -echr 0x14
3622 @itemx -echr 20
3623 @end table
3624 ETEXI
3629 STEXI
3630 @item -virtioconsole @var{c}
3631 @findex -virtioconsole
3632 Set virtio console.
3634 This option is maintained for backward compatibility.
3636 Please use @code{-device virtconsole} for the new way of invocation.
3637 ETEXI
3641 STEXI
3642 @item -show-cursor
3643 @findex -show-cursor
3644 Show cursor.
3645 ETEXI
3649 STEXI
3650 @item -tb-size @var{n}
3651 @findex -tb-size
3652 Set TB size.
3653 ETEXI
3667 QEMU_ARCH_ALL)
3668 STEXI
3669 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3670 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3671 @findex -incoming
3672 Prepare for incoming migration, listen on a given tcp port.
3674 @item -incoming unix:@var{socketpath}
3675 Prepare for incoming migration, listen on a given unix socket.
3677 @item -incoming fd:@var{fd}
3678 Accept incoming migration from a given filedescriptor.
3680 @item -incoming exec:@var{cmdline}
3681 Accept incoming migration as an output from specified external command.
3683 @item -incoming defer
3684 Wait for the URI to be specified via migrate_incoming. The monitor can
3685 be used to change settings (such as migration parameters) prior to issuing
3686 the migrate_incoming to allow the migration to begin.
3687 ETEXI
3691 STEXI
3692 @item -only-migratable
3693 @findex -only-migratable
3694 Only allow migratable devices. Devices will not be allowed to enter an
3695 unmigratable state.
3696 ETEXI
3700 STEXI
3701 @item -nodefaults
3702 @findex -nodefaults
3707 ETEXI
3709 #ifndef _WIN32
3712 QEMU_ARCH_ALL)
3713 #endif
3714 STEXI
3716 @findex -chroot
3717 Immediately before starting guest execution, chroot to the specified
3719 ETEXI
3721 #ifndef _WIN32
3724 QEMU_ARCH_ALL)
3725 #endif
3726 STEXI
3728 @findex -runas
3730 to the specified user.
3731 ETEXI
3736 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3737 STEXI
3741 ETEXI
3744 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3745 QEMU_ARCH_MIPS)
3746 STEXI
3747 @item -semihosting
3748 @findex -semihosting
3750 ETEXI
3754 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3755 QEMU_ARCH_MIPS)
3756 STEXI
3760 @table @option
3766 Allows the user to pass input arguments, and can be used multiple times to build
3771 @end table
3772 ETEXI
3775 STEXI
3779 ETEXI
3783 QEMU_ARCH_ALL)
3784 STEXI
3786 @findex -sandbox
3789 ETEXI
3793 STEXI
3795 @findex -readconfig
3797 QEMU process with many command line options but you don't want to exceed the command line
3798 character limit.
3799 ETEXI
3800 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3803 STEXI
3804 @item -writeconfig @var{file}
3805 @findex -writeconfig
3806 Write device configuration to @var{file}. The @var{file} can be either filename to save
3807 command line and device configuration into file or dash @code{-}) character to print the
3808 output to stdout. This can be later used as input file for @code{-readconfig} option.
3809 ETEXI
3810 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
3813 QEMU_ARCH_ALL)
3814 STEXI
3815 @item -nodefconfig
3816 @findex -nodefconfig
3817 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
3818 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
3819 ETEXI
3820 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3823 QEMU_ARCH_ALL)
3824 STEXI
3825 @item -no-user-config
3826 @findex -no-user-config
3827 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3830 ETEXI
3834 QEMU_ARCH_ALL)
3835 STEXI
3837 HXCOMM HX does not support conditional compilation of text.
3841 ETEXI
3843 HXCOMM Internal use
3847 #ifdef __linux__
3850 QEMU_ARCH_ALL)
3851 #endif
3852 STEXI
3856 ETEXI
3861 HXCOMM Deprecated by kvm-pit driver properties
3878 QEMU_ARCH_ALL)
3879 STEXI
3881 @findex -msg
3883 ETEXI
3891 QEMU_ARCH_ALL)
3892 STEXI
3897 ETEXI
3899 STEXI
3900 @end table
3901 ETEXI
3904 STEXI
3905 @table @option
3906 ETEXI
3914 QEMU_ARCH_ALL)
3915 STEXI
3917 @findex -object
3923 @table @option
3925 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
3927 Creates a memory file backend object, which can be used to back
3929 unique ID that will be used to reference this memory region
3931 option provides the size of the memory region, and accepts
3933 the path to either a shared memory or huge page filesystem mount.
3940 Creates a random number generator backend which obtains entropy from
3948 Creates a random number generator backend which obtains entropy from
3950 a unique ID that will be used to reference this entropy backend from
3952 the unique ID of a character device backend that provides the connection
3953 to the RNG daemon.
3955 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
3957 Creates a TLS anonymous credentials object, which can be used to provide
3959 ID which network backends will use to access the credentials. The
3961 on whether the QEMU network backend that uses the credentials will be
3970 a set of DH parameters at startup. This is a computationally
3971 expensive operation that consumes random pool entropy, so it is
3972 recommended that a persistent set of parameters be generated
3973 upfront and saved.
3975 @item -object tls-creds-x509,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off},passwordid=@var{id}
3977 Creates a TLS anonymous credentials object, which can be used to provide
3979 ID which network backends will use to access the credentials. The
3981 on whether the QEMU network backend that uses the credentials will be
3985 must be provided with valid client certificates too.
3991 a set of DH parameters at startup. This is a computationally
3992 expensive operation that consumes random pool entropy, so it is
3993 recommended that a persistent set of parameters be generated
3994 upfront and saved.
3996 For x509 certificate credentials the directory will contain further files
3997 providing the x509 certificates. The certificates must be stored
4008 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
4011 packets arriving in a given interval on netdev @var{netdevid} are delayed
4012 until the end of the interval. Interval is in microseconds.
4013 @option{status} is optional that indicate whether the netfilter is
4016 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
4018 @option{all}: the filter is attached both to the receive and the transmit
4019 queue of the netdev (default).
4021 @option{rx}: the filter is attached to the receive queue of the netdev,
4022 where it will receive packets sent to the netdev.
4024 @option{tx}: the filter is attached to the transmit queue of the netdev,
4025 where it will receive packets sent by the netdev.
4027 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
4029 filter-mirror on netdev @var{netdevid},mirror net packet to chardev
4030 @var{chardevid}
4032 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},
4033 outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
4035 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
4037 Create a filter-redirector we need to differ outdev id from indev id, id can not
4038 be the same. we can just use indev or outdev, but at least one of indev or outdev
4039 need to be specified.
4041 @item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},rewriter-mode=@var{mode}[,queue=@var{all|rx|tx}]
4043 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
4044 secondary from primary to keep secondary tcp connection,and rewrite
4045 tcp packet to primary from secondary make tcp packet can be handled by
4046 client.
4048 usage:
4049 colo secondary:
4050 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4051 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4052 -object filter-rewriter,id=rew0,netdev=hn0,queue=all
4054 @item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
4056 Dump the network traffic on netdev @var{dev} to the file specified by
4057 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
4058 The file format is libpcap, so it can be analyzed with tools such as tcpdump
4059 or Wireshark.
4061 @item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},
4062 outdev=@var{chardevid}
4064 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
4065 secondary packet. If the packets are same, we will output primary
4066 packet to outdev@var{chardevid}, else we will notify colo-frame
4067 do checkpoint and send primary packet to outdev@var{chardevid}.
4069 we must use it with the help of filter-mirror and filter-redirector.
4071 @example
4073 primary:
4074 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
4075 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
4076 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
4077 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
4078 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
4079 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
4080 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
4081 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
4082 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
4083 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
4084 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
4085 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
4087 secondary:
4088 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
4089 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
4090 -chardev socket,id=red0,host=3.3.3.3,port=9003
4091 -chardev socket,id=red1,host=3.3.3.3,port=9004
4092 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
4093 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
4095 @end example
4097 If you want to know the detail of above command line, you can read
4098 the colo-compare git log.
4100 @item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4102 Creates a cryptodev backend which executes crypto opreation from
4103 the QEMU cipher APIS. The @var{id} parameter is
4104 a unique ID that will be used to reference this cryptodev backend from
4105 the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4106 which specify the queue number of cryptodev backend, the default of
4107 @var{queues} is 1.
4109 @example
4111 # qemu-system-x86_64 \
4112 [...] \
4113 -object cryptodev-backend-builtin,id=cryptodev0 \
4114 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4115 [...]
4116 @end example
4118 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4119 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4121 Defines a secret to store a password, encryption key, or some other sensitive
4122 data. The sensitive data can either be passed directly via the @var{data}
4123 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4124 parameter is insecure unless the sensitive data is encrypted.
4126 The sensitive data can be provided in raw format (the default), or base64.
4127 When encoded as JSON, the raw format only supports valid UTF-8 characters,
4128 so base64 is recommended for sending binary data. QEMU will convert from
4129 which ever format is provided to the format it needs internally. eg, an
4130 RBD password can be provided in raw format, even though it will be base64
4131 encoded when passed onto the RBD sever.
4133 For added protection, it is possible to encrypt the data associated with
4134 a secret using the AES-256-CBC cipher. Use of encryption is indicated
4135 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4136 parameter provides the ID of a previously defined secret that contains
4137 the AES-256 decryption key. This key should be 32-bytes long and be
4138 base64 encoded. The @var{iv} parameter provides the random initialization
4139 vector used for encryption of this particular secret and should be a
4140 base64 encrypted string of the 16-byte IV.
4142 The simplest (insecure) usage is to provide the secret inline
4144 @example
4146 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4148 @end example
4150 The simplest secure usage is to provide the secret via a file
4152 # echo -n "letmein" > mypasswd.txt
4153 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4155 For greater security, AES-256-CBC should be used. To illustrate usage,
4156 consider the openssl command line tool which can encrypt the data. Note
4157 that when encrypting, the plaintext must be padded to the cipher block
4158 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4160 First a master key needs to be created in base64 encoding:
4162 @example
4163 # openssl rand -base64 32 > key.b64
4165 @end example
4167 Each secret to be encrypted needs to have a random initialization vector
4168 generated. These do not need to be kept secret
4170 @example
4171 # openssl rand -base64 16 > iv.b64
4173 @end example
4175 The secret to be defined can now be encrypted, in this case we're
4176 telling openssl to base64 encode the result, but it could be left
4179 @example
4182 @end example
4185 and specify that to be used to decrypt the user password. Pass the
4188 @example
4189 # $QEMU \
4193 @end example
4195 @end table
4197 ETEXI
4201 STEXI
4202 @end table
4203 ETEXI