| blob | 733a1949e98a252e23b4dace3315ab3d595b300e |
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
47 QEMU_ARCH_ALL)
48 STEXI
50 @findex -machine
53 @table @option
58 to initialize.
59 @item kernel_irqchip=on|off
61 @item gfx_passthru=on|off
63 @item vmport=on|off|auto
66 is on.
67 @item kvm_shadow_mem=size
68 Defines the size of the KVM shadow MMU.
75 @item iommu=on|off
79 controls whether AES wrapping keys will be created to allow
83 controls whether DEA wrapping keys will be created to allow
85 @item nvdimm=on|off
87 @end table
88 ETEXI
90 HXCOMM Deprecated by -machine
95 STEXI
97 @findex -cpu
99 ETEXI
109 QEMU_ARCH_ALL)
110 STEXI
111 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
112 @findex -smp
120 specifies the maximum number of hotpluggable CPUs.
121 ETEXI
126 STEXI
129 @findex -numa
133 resources. That is, it just assigns existing resources to NUMA nodes. This
134 means that one still has to use the @option{-m}, @option{-smp} options
135 to allocate RAM and VCPUs respectively, and possibly @option{-object}
136 to specify the memory backend for the @samp{memdev} suboption.
138 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
139 node uses @samp{memdev}, all of them have to use it.
140 ETEXI
142 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
145 STEXI
146 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
147 @findex -add-fd
149 Add a file descriptor to an fd set. Valid options are:
151 @table @option
152 @item fd=@var{fd}
153 This option defines the file descriptor of which a duplicate is added to fd set.
154 The file descriptor cannot be stdin, stdout, or stderr.
155 @item set=@var{set}
156 This option defines the ID of the fd set to add the file descriptor to.
157 @item opaque=@var{opaque}
158 This option defines a free-form string that can be used to describe @var{fd}.
159 @end table
161 You can open an image using pre-opened file descriptors from an fd set:
162 @example
163 qemu-system-i386
164 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
165 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
166 -drive file=/dev/fdset/2,index=0,media=disk
167 @end example
168 ETEXI
170 DEF("set", HAS_ARG, QEMU_OPTION_set,
174 STEXI
175 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
176 @findex -set
178 ETEXI
180 DEF("global", HAS_ARG, QEMU_OPTION_global,
184 QEMU_ARCH_ALL)
185 STEXI
186 @item -global @var{driver}.@var{prop}=@var{value}
187 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
188 @findex -global
191 @example
192 qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk
193 @end example
196 created automatically by the machine model. To create a device which is not
202 ETEXI
211 QEMU_ARCH_ALL)
212 STEXI
213 @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]
214 @findex -boot
219 particular boot order only on the first startup, specify it via
235 system support it.
238 supports it. This only effects when boot priority is changed by
241 @example
248 @end example
251 use is discouraged as it may be removed from future versions.
252 ETEXI
261 QEMU_ARCH_ALL)
262 STEXI
264 @findex -m
268 could be used to set amount of hotpluggable memory slots and maximum amount of
275 @example
277 @end example
280 be enabled and the guest startup RAM will never increase.
281 ETEXI
283 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
285 STEXI
286 @item -mem-path @var{path}
287 @findex -mem-path
288 Allocate guest RAM from a temporarily created file in @var{path}.
289 ETEXI
291 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
293 QEMU_ARCH_ALL)
294 STEXI
295 @item -mem-prealloc
296 @findex -mem-prealloc
297 Preallocate memory when using -mem-path.
298 ETEXI
300 DEF("k", HAS_ARG, QEMU_OPTION_k,
302 QEMU_ARCH_ALL)
303 STEXI
304 @item -k @var{language}
305 @findex -k
306 Use keyboard layout @var{language} (for example @code{fr} for
307 French). This option is only needed where it is not easy to get raw PC
308 keycodes (e.g. on Macs, with some X11 servers or with a VNC
310 hosts.
312 The available layouts are:
313 @example
317 @end example
320 ETEXI
325 QEMU_ARCH_ALL)
326 STEXI
330 parameters.
331 ETEXI
338 STEXI
340 @findex -soundhw
342 available sound hardware.
344 @example
351 @end example
353 Note that Linux's i810_audio OSS kernel (for AC97) module might
354 require manually specifying clocking.
356 @example
357 modprobe i810_audio clocking=48000
358 @end example
359 ETEXI
361 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
365 STEXI
366 @item -balloon none
367 @findex -balloon
368 Disable balloon device.
369 @item -balloon virtio[,addr=@var{addr}]
370 Enable virtio balloon device (default), optionally with PCI address
371 @var{addr}.
372 ETEXI
374 DEF("device", HAS_ARG, QEMU_OPTION_device,
380 QEMU_ARCH_ALL)
381 STEXI
382 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
383 @findex -device
384 Add device @var{driver}. @var{prop}=@var{value} sets driver
385 properties. Valid properties depend on the driver. To get help on
386 possible drivers and properties, use @code{-device help} and
387 @code{-device @var{driver},help}.
389 Some drivers are:
390 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}]
392 Add an IPMI BMC. This is a simulation of a hardware management
393 interface processor that normally sits on a system. It provides
394 a watchdog and the ability to reset and power control the system.
395 You need to connect this to an IPMI interface to make it useful
397 The IPMI slave address to use for the BMC. The default is 0x20.
398 This address is the BMC's address on the I2C network of management
400 it.
402 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
404 Add a connection to an external IPMI BMC simulator. Instead of
405 locally emulating the BMC like the above item, instead connect
406 to an external entity that provides the IPMI services.
408 A connection is made to an external BMC simulator. If you do this, it
409 is strongly recommended that you use the "reconnect=" chardev option
410 to reconnect to the simulator if the connection is lost. Note that if
411 this is not used carefully, it can be a security issue, as the
412 interface has the ability to send resets, NMIs, and power off the VM.
414 on a secure port on localhost, so neither the simulator nor QEMU is
415 exposed to any outside network.
422 Add a KCS IPMI interafce on the ISA bus. This also adds a
425 @table @option
433 @end table
440 ETEXI
448 QEMU_ARCH_ALL)
449 STEXI
451 @findex -name
456 Naming of individual threads can also be enabled on Linux to aid debugging.
457 ETEXI
462 STEXI
464 @findex -uuid
465 Set system UUID.
466 ETEXI
468 STEXI
469 @end table
470 ETEXI
474 STEXI
475 @table @option
476 ETEXI
481 STEXI
484 @findex -fda
485 @findex -fdb
487 ETEXI
495 STEXI
500 @findex -hda
501 @findex -hdb
502 @findex -hdc
503 @findex -hdd
505 ETEXI
509 QEMU_ARCH_ALL)
510 STEXI
512 @findex -cdrom
516 ETEXI
533 STEXI
535 @findex -drive
539 @table @option
545 Special files such as iSCSI devices can be specified using protocol
551 These options define where is connected the drive by defining the bus number and
552 the unit id.
564 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
566 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
568 @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.
572 an untrusted format header.
574 This option specifies the serial number to assign to the device.
576 Specify the controller's PCI address (if=virtio only).
577 @item werror=@var{action},rerror=@var{action}
578 Specify which @var{action} to take on write and read errors. Valid actions are:
579 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
580 "report" (report the error to the guest), "enospc" (pause QEMU only if the
581 host disk is full; report the error to the guest otherwise).
582 The default setting is @option{werror=enospc} and @option{rerror=report}.
583 @item readonly
584 Open drive @option{file} as read-only. Guest write attempts will fail.
585 @item copy-on-read=@var{copy-on-read}
586 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
587 file sectors into the image file.
588 @item detect-zeroes=@var{detect-zeroes}
589 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
590 conversion of plain zero writes by the OS to driver specific optimized
591 zero write commands. You may even choose "unmap" if @var{discard} is set
592 to "unmap" to allow a zero write to be converted to an UNMAP operation.
593 @end table
595 By default, the @option{cache=writeback} mode is used. It will report data
596 writes as completed as soon as the data is present in the host page cache.
597 This is safe as long as your guest OS makes sure to correctly flush disk caches
598 where needed. If your guest OS does not handle volatile disk write caches
599 correctly and your host crashes or loses power, then the guest may experience
600 data corruption.
602 For such guests, you should consider using @option{cache=writethrough}. This
603 means that the host page cache will be used to read and write data, but write
604 notification will be sent to the guest only after QEMU has made sure to flush
605 each write to the disk. Be aware that this has a major impact on performance.
607 The host page cache can be avoided entirely with @option{cache=none}. This will
610 the guest OS must handle the disk write cache correctly in order to avoid data
611 corruption on host crashes.
613 The host page cache can be avoided while only sending write notifications to
614 the guest when the data has been flushed to the disk using
618 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
619 data to the disk but can instead keep things in cache. If anything goes wrong,
620 like your host losing power, the disk storage getting disconnected accidentally,
621 etc. your image will most probably be rendered unusable. When using
622 the @option{-snapshot} option, unsafe caching is always used.
624 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
625 useful when the backing file is over a slow network. By default copy-on-read
626 is off.
628 Instead of @option{-cdrom} you can use:
629 @example
630 qemu-system-i386 -drive file=file,index=2,media=cdrom
631 @end example
633 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
634 use:
635 @example
636 qemu-system-i386 -drive file=file,index=0,media=disk
637 qemu-system-i386 -drive file=file,index=1,media=disk
638 qemu-system-i386 -drive file=file,index=2,media=disk
639 qemu-system-i386 -drive file=file,index=3,media=disk
640 @end example
642 You can open an image using pre-opened file descriptors from an fd set:
643 @example
644 qemu-system-i386
645 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
646 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
647 -drive file=/dev/fdset/2,index=0,media=disk
648 @end example
650 You can connect a CDROM to the slave of ide0:
651 @example
652 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
653 @end example
656 @example
658 @end example
661 @example
663 @end example
666 @example
669 @end example
672 incremented:
673 @example
675 @end example
676 is interpreted like:
677 @example
678 qemu-system-i386 -hda a -hdb b
679 @end example
680 ETEXI
684 QEMU_ARCH_ALL)
685 STEXI
686 @item -mtdblock @var{file}
687 @findex -mtdblock
688 Use @var{file} as on-board Flash memory image.
689 ETEXI
693 STEXI
694 @item -sd @var{file}
695 @findex -sd
696 Use @var{file} as SecureDigital card image.
697 ETEXI
701 STEXI
702 @item -pflash @var{file}
703 @findex -pflash
704 Use @var{file} as a parallel flash image.
705 ETEXI
709 QEMU_ARCH_ALL)
710 STEXI
711 @item -snapshot
712 @findex -snapshot
713 Write to temporary files instead of disk image files. In this case,
714 the raw disk image you use is not written back. You can however force
715 the write back by pressing @key{C-a s} (@pxref{disk_images}).
716 ETEXI
722 QEMU_ARCH_ALL)
723 STEXI
724 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
725 @findex -hdachs
726 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
727 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
728 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
729 all those parameters. This option is useful for old MS-DOS disk
730 images.
731 ETEXI
734 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
736 QEMU_ARCH_ALL)
738 STEXI
740 @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}]
741 @findex -fsdev
742 Define a new file system device. Valid options are:
743 @table @option
744 @item @var{fsdriver}
745 This option specifies the fs driver backend to use.
747 @item id=@var{id}
748 Specifies identifier for this device
749 @item path=@var{path}
750 Specifies the export path for the file system device. Files under
751 this path will be available to the 9p client on the guest.
752 @item security_model=@var{security_model}
753 Specifies the security model to be used for this export path.
756 credentials as they are created on the guest. This requires QEMU
758 attributes like uid, gid, mode bits and link target are stored as
760 hidden .virtfs_metadata directory. Directories exported by this security model cannot
762 passthrough except the sever won't report failures if it fails to
763 set file attributes like ownership. Security model is mandatory
764 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
765 security model as a parameter.
766 @item writeout=@var{writeout}
768 This means that host page cache will be used to read and write data but
769 write notification will be sent to the guest only when the data has been
770 reported as written by the storage subsystem.
771 @item readonly
772 Enables exporting 9p share as a readonly mount for guests. By default
773 read-write access is given.
774 @item socket=@var{socket}
775 Enables proxy filesystem driver to use passed socket file for communicating
776 with virtfs-proxy-helper
777 @item sock_fd=@var{sock_fd}
778 Enables proxy filesystem driver to use passed socket descriptor for
779 communicating with virtfs-proxy-helper. Usually a helper like libvirt
780 will create socketpair and pass one of the fds as sock_fd
781 @end table
784 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
785 Options for virtio-9p-pci driver are:
786 @table @option
787 @item fsdev=@var{id}
788 Specifies the id value specified along with -fsdev option
789 @item mount_tag=@var{mount_tag}
790 Specifies the tag name to be used by the guest to mount this export point
791 @end table
793 ETEXI
796 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
798 QEMU_ARCH_ALL)
800 STEXI
802 @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}]
803 @findex -virtfs
805 The general form of a Virtual File system pass-through options are:
806 @table @option
807 @item @var{fsdriver}
808 This option specifies the fs driver backend to use.
810 @item id=@var{id}
811 Specifies identifier for this device
812 @item path=@var{path}
813 Specifies the export path for the file system device. Files under
814 this path will be available to the 9p client on the guest.
815 @item security_model=@var{security_model}
816 Specifies the security model to be used for this export path.
819 credentials as they are created on the guest. This requires QEMU
821 attributes like uid, gid, mode bits and link target are stored as
823 hidden .virtfs_metadata directory. Directories exported by this security model cannot
825 passthrough except the sever won't report failures if it fails to
826 set file attributes like ownership. Security model is mandatory only
827 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
828 model as a parameter.
829 @item writeout=@var{writeout}
831 This means that host page cache will be used to read and write data but
832 write notification will be sent to the guest only when the data has been
833 reported as written by the storage subsystem.
834 @item readonly
835 Enables exporting 9p share as a readonly mount for guests. By default
836 read-write access is given.
837 @item socket=@var{socket}
838 Enables proxy filesystem driver to use passed socket file for
839 communicating with virtfs-proxy-helper. Usually a helper like libvirt
840 will create socketpair and pass one of the fds as sock_fd
841 @item sock_fd
842 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
843 descriptor for interfacing with virtfs-proxy-helper
844 @end table
845 ETEXI
849 QEMU_ARCH_ALL)
850 STEXI
851 @item -virtfs_synth
852 @findex -virtfs_synth
853 Create synthetic file system image
854 ETEXI
856 STEXI
857 @end table
858 ETEXI
859 DEFHEADING()
861 DEFHEADING(USB options:)
862 STEXI
863 @table @option
864 ETEXI
868 QEMU_ARCH_ALL)
869 STEXI
870 @item -usb
871 @findex -usb
872 Enable the USB driver (will be the default soon)
873 ETEXI
877 QEMU_ARCH_ALL)
878 STEXI
880 @item -usbdevice @var{devname}
881 @findex -usbdevice
882 Add the USB device @var{devname}. @xref{usb_devices}.
884 @table @option
886 @item mouse
887 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
889 @item tablet
890 Pointer device that uses absolute coordinates (like a touchscreen). This
891 means QEMU is able to report the mouse position without having to grab the
892 mouse. Also overrides the PS/2 mouse emulation when activated.
894 @item disk:[format=@var{format}]:@var{file}
895 Mass storage device based on file. The optional @var{format} argument
896 will be used rather than detecting the format. Can be used to specifiy
897 @code{format=raw} to avoid interpreting an untrusted format header.
899 @item host:@var{bus}.@var{addr}
900 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
902 @item host:@var{vendor_id}:@var{product_id}
903 Pass through the host device identified by @var{vendor_id}:@var{product_id}
904 (Linux only).
906 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
907 Serial converter to host character device @var{dev}, see @code{-serial} for the
908 available devices.
910 @item braille
911 Braille device. This will use BrlAPI to display the braille output on a real
912 or fake device.
914 @item net:@var{options}
915 Network adapter that supports CDC ethernet and RNDIS protocols.
917 @end table
918 ETEXI
920 STEXI
921 @end table
922 ETEXI
923 DEFHEADING()
925 DEFHEADING(Display options:)
926 STEXI
927 @table @option
928 ETEXI
936 STEXI
937 @item -display @var{type}
938 @findex -display
939 Select type of display to use. This option is a replacement for the
940 old style -sdl/-curses/... options. Valid values for @var{type} are
941 @table @option
942 @item sdl
943 Display video output via SDL (usually in a separate graphics
944 window; see the SDL documentation for other possibilities).
945 @item curses
946 Display video output via curses. For graphics device models which
947 support a text mode, QEMU can display this output using a
948 curses/ncurses interface. Nothing is displayed when the graphics
949 device is in graphical mode or if the graphics device does not support
950 a text mode. Generally only the VGA device models support text mode.
951 @item none
952 Do not display video output. The guest will still see an emulated
953 graphics card, but its output will not be displayed to the QEMU
954 user. This option differs from the -nographic option in that it
955 only affects what is done with video output; -nographic also changes
956 the destination of the serial and parallel port data.
957 @item gtk
958 Display video output in a GTK window. This interface provides drop-down
959 menus and other UI elements to configure and control the VM during
960 runtime.
961 @item vnc
962 Start a VNC server on display <arg>
963 @end table
964 ETEXI
968 QEMU_ARCH_ALL)
969 STEXI
970 @item -nographic
971 @findex -nographic
972 Normally, QEMU uses SDL to display the VGA output. With this option,
973 you can totally disable graphical output so that QEMU is a simple
974 command line application. The emulated serial port is redirected on
975 the console and muxed with the monitor (unless redirected elsewhere
976 explicitly). Therefore, you can still use QEMU to debug a Linux kernel
977 with a serial console. Use @key{C-a h} for help on switching between
978 the console and monitor.
979 ETEXI
983 QEMU_ARCH_ALL)
984 STEXI
985 @item -curses
986 @findex -curses
987 Normally, QEMU uses SDL to display the VGA output. With this option,
988 QEMU can display the VGA output when in text mode using a
989 curses/ncurses interface. Nothing is displayed in graphical mode.
990 ETEXI
994 QEMU_ARCH_ALL)
995 STEXI
996 @item -no-frame
997 @findex -no-frame
998 Do not use decorations for SDL windows and start them using the whole
999 available screen space. This makes the using QEMU in a dedicated desktop
1000 workspace more convenient.
1001 ETEXI
1005 QEMU_ARCH_ALL)
1006 STEXI
1007 @item -alt-grab
1008 @findex -alt-grab
1009 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1010 affects the special keys (for fullscreen, monitor-mode switching, etc).
1011 ETEXI
1015 QEMU_ARCH_ALL)
1016 STEXI
1017 @item -ctrl-grab
1018 @findex -ctrl-grab
1019 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1020 affects the special keys (for fullscreen, monitor-mode switching, etc).
1021 ETEXI
1025 STEXI
1026 @item -no-quit
1027 @findex -no-quit
1028 Disable SDL window close capability.
1029 ETEXI
1033 STEXI
1034 @item -sdl
1035 @findex -sdl
1036 Enable SDL.
1037 ETEXI
1056 QEMU_ARCH_ALL)
1057 STEXI
1058 @item -spice @var{option}[,@var{option}[,...]]
1059 @findex -spice
1060 Enable the spice remote desktop protocol. Valid options are
1062 @table @option
1064 @item port=<nr>
1065 Set the TCP port spice is listening on for plaintext channels.
1067 @item addr=<addr>
1068 Set the IP address spice is listening on. Default is any address.
1070 @item ipv4
1071 @itemx ipv6
1072 @itemx unix
1073 Force using the specified IP version.
1075 @item password=<secret>
1076 Set the password you need to authenticate.
1078 @item sasl
1079 Require that the client use SASL to authenticate with the spice.
1080 The exact choice of authentication method used is controlled from the
1081 system / user's SASL configuration file for the 'qemu' service. This
1082 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1083 unprivileged user, an environment variable SASL_CONF_PATH can be used
1084 to make it search alternate locations for the service config.
1085 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1086 it is recommended that SASL always be combined with the 'tls' and
1087 'x509' settings to enable use of SSL and server certificates. This
1088 ensures a data encryption preventing compromise of authentication
1089 credentials.
1091 @item disable-ticketing
1092 Allow client connects without authentication.
1094 @item disable-copy-paste
1095 Disable copy paste between the client and the guest.
1097 @item disable-agent-file-xfer
1098 Disable spice-vdagent based file-xfer between the client and the guest.
1100 @item tls-port=<nr>
1101 Set the TCP port spice is listening on for encrypted channels.
1103 @item x509-dir=<dir>
1104 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1106 @item x509-key-file=<file>
1107 @itemx x509-key-password=<file>
1108 @itemx x509-cert-file=<file>
1109 @itemx x509-cacert-file=<file>
1110 @itemx x509-dh-key-file=<file>
1111 The x509 file names can also be configured individually.
1113 @item tls-ciphers=<list>
1114 Specify which ciphers to use.
1116 @item tls-channel=[main|display|cursor|inputs|record|playback]
1117 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1118 Force specific channel to be used with or without TLS encryption. The
1119 options can be specified multiple times to configure multiple
1121 mode. For channels which are not explicitly forced into one mode the
1122 spice client is allowed to pick tls/plaintext as he pleases.
1124 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1125 Configure image compression (lossless).
1126 Default is auto_glz.
1128 @item jpeg-wan-compression=[auto|never|always]
1129 @itemx zlib-glz-wan-compression=[auto|never|always]
1130 Configure wan image compression (lossy for slow links).
1131 Default is auto.
1133 @item streaming-video=[off|all|filter]
1134 Configure video stream detection. Default is filter.
1136 @item agent-mouse=[on|off]
1137 Enable/disable passing mouse events via vdagent. Default is on.
1139 @item playback-compression=[on|off]
1140 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1142 @item seamless-migration=[on|off]
1143 Enable/disable spice seamless migration. Default is off.
1145 @end table
1146 ETEXI
1150 QEMU_ARCH_ALL)
1151 STEXI
1152 @item -portrait
1153 @findex -portrait
1154 Rotate graphical output 90 deg left (only PXA LCD).
1155 ETEXI
1159 QEMU_ARCH_ALL)
1160 STEXI
1161 @item -rotate @var{deg}
1162 @findex -rotate
1163 Rotate graphical output some deg left (only PXA LCD).
1164 ETEXI
1169 STEXI
1170 @item -vga @var{type}
1171 @findex -vga
1172 Select type of VGA card to emulate. Valid values for @var{type} are
1173 @table @option
1174 @item cirrus
1175 Cirrus Logic GD5446 Video card. All Windows versions starting from
1176 Windows 95 should recognize and use this graphic card. For optimal
1177 performances, use 16 bit color depth in the guest and the host OS.
1178 (This one is the default)
1179 @item std
1180 Standard VGA card with Bochs VBE extensions. If your guest OS
1181 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1182 to use high resolution modes (>= 1280x1024x16) then you should use
1183 this option.
1184 @item vmware
1185 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1186 recent XFree86/XOrg server or Windows guest with a driver for this
1187 card.
1188 @item qxl
1189 QXL paravirtual graphic card. It is VGA compatible (including VESA
1190 2.0 VBE support). Works best with qxl guest drivers installed though.
1191 Recommended choice when using the spice protocol.
1192 @item tcx
1193 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1194 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1195 fixed resolution of 1024x768.
1196 @item cg3
1197 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1198 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1199 resolutions aimed at people wishing to run older Solaris versions.
1200 @item virtio
1201 Virtio VGA card.
1202 @item none
1203 Disable VGA card.
1204 @end table
1205 ETEXI
1209 STEXI
1210 @item -full-screen
1211 @findex -full-screen
1212 Start in full screen.
1213 ETEXI
1217 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1218 STEXI
1219 @item -g @var{width}x@var{height}[x@var{depth}]
1220 @findex -g
1221 Set the initial graphical resolution and depth (PPC, SPARC only).
1222 ETEXI
1226 STEXI
1227 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1228 @findex -vnc
1229 Normally, QEMU uses SDL to display the VGA output. With this option,
1230 you can have QEMU listen on VNC display @var{display} and redirect the VGA
1231 display over the VNC session. It is very useful to enable the usb
1232 tablet device when using this option (option @option{-usbdevice
1233 tablet}). When using the VNC display, you must use the @option{-k}
1234 parameter to set the keyboard layout if you are not using en-us. Valid
1235 syntax for the @var{display} is
1237 @table @option
1239 @item @var{host}:@var{d}
1241 TCP connections will only be allowed from @var{host} on display @var{d}.
1242 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1243 be omitted in which case the server will accept connections from any host.
1245 @item unix:@var{path}
1247 Connections will be allowed over UNIX domain sockets where @var{path} is the
1248 location of a unix socket to listen for connections on.
1250 @item none
1252 VNC is initialized but not started. The monitor @code{change} command
1253 can be used to later start the VNC server.
1255 @end table
1257 Following the @var{display} value there may be one or more @var{option} flags
1258 separated by commas. Valid options are
1260 @table @option
1262 @item reverse
1264 Connect to a listening VNC client via a ``reverse'' connection. The
1265 client is specified by the @var{display}. For reverse network
1266 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1267 is a TCP port number, not a display number.
1269 @item websocket
1271 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1272 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1273 specified connections will only be allowed from this host.
1274 As an alternative the Websocket port could be specified by using
1275 @code{websocket}=@var{port}.
1276 If no TLS credentials are provided, the websocket connection runs in
1277 unencrypted mode. If TLS credentials are provided, the websocket connection
1278 requires encrypted client connections.
1280 @item password
1282 Require that password based authentication is used for client connections.
1284 The password must be set separately using the @code{set_password} command in
1285 the @ref{pcsys_monitor}. The syntax to change your password is:
1286 @code{set_password <protocol> <password>} where <protocol> could be either
1289 If you would like to change <protocol> password expiration, you should use
1290 @code{expire_password <protocol> <expiration-time>} where expiration time could
1291 be one of the following options: now, never, +seconds or UNIX time of
1292 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1294 date and time).
1297 allow <protocol> password to expire immediately or never expire.
1299 @item tls-creds=@var{ID}
1301 Provides the ID of a set of TLS credentials to use to secure the
1302 VNC server. They will apply to both the normal VNC server socket
1303 and the websocket socket (if enabled). Setting TLS credentials
1304 will cause the VNC server socket to enable the VeNCrypt auth
1305 mechanism. The credentials should have been previously created
1306 using the @option{-object tls-creds} argument.
1308 The @option{tls-creds} parameter obsoletes the @option{tls},
1309 @option{x509}, and @option{x509verify} options, and as such
1310 it is not permitted to set both new and old type options at
1311 the same time.
1313 @item tls
1315 Require that client use TLS when communicating with the VNC server. This
1316 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1317 attack. It is recommended that this option be combined with either the
1318 @option{x509} or @option{x509verify} options.
1320 This option is now deprecated in favor of using the @option{tls-creds}
1321 argument.
1323 @item x509=@var{/path/to/certificate/dir}
1325 Valid if @option{tls} is specified. Require that x509 credentials are used
1326 for negotiating the TLS session. The server will send its x509 certificate
1327 to the client. It is recommended that a password be set on the VNC server
1328 to provide authentication of the client when this is used. The path following
1329 this option specifies where the x509 certificates are to be loaded from.
1330 See the @ref{vnc_security} section for details on generating certificates.
1332 This option is now deprecated in favour of using the @option{tls-creds}
1333 argument.
1335 @item x509verify=@var{/path/to/certificate/dir}
1337 Valid if @option{tls} is specified. Require that x509 credentials are used
1338 for negotiating the TLS session. The server will send its x509 certificate
1339 to the client, and request that the client send its own x509 certificate.
1340 The server will validate the client's certificate against the CA certificate,
1341 and reject clients when validation fails. If the certificate authority is
1342 trusted, this is a sufficient authentication mechanism. You may still wish
1343 to set a password on the VNC server as a second authentication layer. The
1344 path following this option specifies where the x509 certificates are to
1345 be loaded from. See the @ref{vnc_security} section for details on generating
1346 certificates.
1348 This option is now deprecated in favour of using the @option{tls-creds}
1349 argument.
1351 @item sasl
1353 Require that the client use SASL to authenticate with the VNC server.
1354 The exact choice of authentication method used is controlled from the
1355 system / user's SASL configuration file for the 'qemu' service. This
1356 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1357 unprivileged user, an environment variable SASL_CONF_PATH can be used
1358 to make it search alternate locations for the service config.
1359 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1360 it is recommended that SASL always be combined with the 'tls' and
1361 'x509' settings to enable use of SSL and server certificates. This
1362 ensures a data encryption preventing compromise of authentication
1363 credentials. See the @ref{vnc_security} section for details on using
1364 SASL authentication.
1366 @item acl
1368 Turn on access control lists for checking of the x509 client certificate
1369 and SASL party. For x509 certs, the ACL check is made against the
1370 certificate's distinguished name. This is something that looks like
1371 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1372 made against the username, which depending on the SASL plugin, may
1373 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1374 When the @option{acl} flag is set, the initial access list will be
1375 empty, with a @code{deny} policy. Thus no one will be allowed to
1376 use the VNC server until the ACLs have been loaded. This can be
1377 achieved using the @code{acl} monitor command.
1379 @item lossy
1381 Enable lossy compression methods (gradient, JPEG, ...). If this
1382 option is set, VNC client may receive lossy framebuffer updates
1383 depending on its encoding settings. Enabling this option can save
1384 a lot of bandwidth at the expense of quality.
1386 @item non-adaptive
1388 Disable adaptive encodings. Adaptive encodings are enabled by default.
1389 An adaptive encoding will try to detect frequently updated screen regions,
1390 and send updates in these regions using a lossy encoding (like JPEG).
1391 This can be really helpful to save bandwidth when playing videos. Disabling
1392 adaptive encodings restores the original static behavior of encodings
1393 like Tight.
1395 @item share=[allow-exclusive|force-shared|ignore]
1397 Set display sharing policy. 'allow-exclusive' allows clients to ask
1398 for exclusive access. As suggested by the rfb spec this is
1399 implemented by dropping other connections. Connecting multiple
1400 clients in parallel requires all clients asking for a shared session
1401 (vncviewer: -shared switch). This is the default. 'force-shared'
1402 disables exclusive client access. Useful for shared desktop sessions,
1403 where you don't want someone forgetting specify -shared disconnect
1404 everybody else. 'ignore' completely ignores the shared flag and
1405 allows everybody connect unconditionally. Doesn't conform to the rfb
1406 spec but is traditional QEMU behavior.
1408 @end table
1409 ETEXI
1411 STEXI
1412 @end table
1413 ETEXI
1414 ARCHHEADING(, QEMU_ARCH_I386)
1416 ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
1417 STEXI
1418 @table @option
1419 ETEXI
1423 QEMU_ARCH_I386)
1424 STEXI
1425 @item -win2k-hack
1426 @findex -win2k-hack
1427 Use it when installing Windows 2000 to avoid a disk full bug. After
1428 Windows 2000 is installed, you no longer need this option (this option
1429 slows down the IDE transfers).
1430 ETEXI
1432 HXCOMM Deprecated by -rtc
1437 QEMU_ARCH_I386)
1438 STEXI
1439 @item -no-fd-bootchk
1440 @findex -no-fd-bootchk
1441 Disable boot signature checking for floppy disks in BIOS. May
1442 be needed to boot from old floppy disks.
1443 ETEXI
1447 STEXI
1448 @item -no-acpi
1449 @findex -no-acpi
1450 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1451 it if your guest OS complains about ACPI problems (PC target machine
1452 only).
1453 ETEXI
1457 STEXI
1458 @item -no-hpet
1459 @findex -no-hpet
1460 Disable HPET support.
1461 ETEXI
1464 "-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"
1466 STEXI
1467 @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}]...]
1468 @findex -acpitable
1469 Add ACPI table with specified header fields and context from specified files.
1470 For file=, take whole ACPI table from the specified files, including all
1471 ACPI headers (possible overridden by other options).
1472 For data=, only data
1473 portion of the table is used, all header information is specified in the
1474 command line.
1475 ETEXI
1498 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1499 STEXI
1500 @item -smbios file=@var{binary}
1501 @findex -smbios
1502 Load SMBIOS entry from binary file.
1504 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1505 Specify SMBIOS type 0 fields
1507 @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}]
1508 Specify SMBIOS type 1 fields
1510 @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}]
1511 Specify SMBIOS type 2 fields
1513 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1514 Specify SMBIOS type 3 fields
1516 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1517 Specify SMBIOS type 4 fields
1519 @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}]
1520 Specify SMBIOS type 17 fields
1521 ETEXI
1523 STEXI
1524 @end table
1525 ETEXI
1526 DEFHEADING()
1528 DEFHEADING(Network options:)
1529 STEXI
1530 @table @option
1531 ETEXI
1533 HXCOMM Legacy slirp options (now moved to -net user):
1534 #ifdef CONFIG_SLIRP
1538 #ifndef _WIN32
1540 #endif
1541 #endif
1544 #ifdef CONFIG_SLIRP
1548 #ifndef _WIN32
1550 #endif
1553 #endif
1554 #ifdef _WIN32
1557 #else
1584 #endif
1585 #ifdef __linux__
1611 #endif
1621 #ifdef CONFIG_VDE
1627 #endif
1628 #ifdef CONFIG_NETMAP
1633 #endif
1647 #ifdef CONFIG_SLIRP
1649 #endif
1652 #ifdef CONFIG_VDE
1654 #endif
1655 #ifdef CONFIG_NETMAP
1657 #endif
1661 STEXI
1662 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1663 @findex -net
1664 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1665 = 0 is the default). The NIC is an e1000 by default on the PC
1666 target. Optionally, the MAC address can be changed to @var{mac}, the
1667 device address set to @var{addr} (PCI cards only),
1668 and a @var{name} can be assigned for use in monitor commands.
1669 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1670 that the card should have; this option currently only affects virtio cards; set
1671 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1672 NIC is created. QEMU can emulate several different models of network card.
1673 Valid values for @var{type} are
1674 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1675 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1676 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1677 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1678 for a list of available devices for your target.
1680 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1681 @findex -netdev
1682 @item -net user[,@var{option}][,@var{option}][,...]
1683 Use the user mode network stack which requires no administrator
1684 privilege to run. Valid options are:
1686 @table @option
1687 @item vlan=@var{n}
1688 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1690 @item id=@var{id}
1691 @itemx name=@var{name}
1692 Assign symbolic name for use in monitor commands.
1694 @item net=@var{addr}[/@var{mask}]
1695 Set IP network address the guest will see. Optionally specify the netmask,
1696 either in the form a.b.c.d or as number of valid top-most bits. Default is
1697 10.0.2.0/24.
1699 @item host=@var{addr}
1700 Specify the guest-visible address of the host. Default is the 2nd IP in the
1701 guest network, i.e. x.x.x.2.
1703 @item restrict=on|off
1704 If this option is enabled, the guest will be isolated, i.e. it will not be
1705 able to contact the host and no guest IP packets will be routed over the host
1706 to the outside. This option does not affect any explicitly set forwarding rules.
1708 @item hostname=@var{name}
1709 Specifies the client hostname reported by the built-in DHCP server.
1711 @item dhcpstart=@var{addr}
1712 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1713 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1715 @item dns=@var{addr}
1716 Specify the guest-visible address of the virtual nameserver. The address must
1717 be different from the host address. Default is the 3rd IP in the guest network,
1718 i.e. x.x.x.3.
1720 @item dnssearch=@var{domain}
1721 Provides an entry for the domain-search list sent by the built-in
1722 DHCP server. More than one domain suffix can be transmitted by specifying
1723 this option multiple times. If supported, this will cause the guest to
1724 automatically try to append the given domain suffix(es) in case a domain name
1725 can not be resolved.
1727 Example:
1728 @example
1729 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1730 @end example
1732 @item tftp=@var{dir}
1733 When using the user mode network stack, activate a built-in TFTP
1734 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1735 The TFTP client on the guest must be configured in binary mode (use the command
1736 @code{bin} of the Unix TFTP client).
1738 @item bootfile=@var{file}
1739 When using the user mode network stack, broadcast @var{file} as the BOOTP
1740 filename. In conjunction with @option{tftp}, this can be used to network boot
1741 a guest from a local directory.
1743 Example (using pxelinux):
1744 @example
1745 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1746 @end example
1748 @item smb=@var{dir}[,smbserver=@var{addr}]
1749 When using the user mode network stack, activate a built-in SMB
1750 server so that Windows OSes can access to the host files in @file{@var{dir}}
1751 transparently. The IP address of the SMB server can be set to @var{addr}. By
1752 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1754 In the guest Windows OS, the line:
1755 @example
1756 10.0.2.4 smbserver
1757 @end example
1758 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1759 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1763 Note that a SAMBA server must be installed on the host OS.
1764 QEMU was tested successfully with smbd versions from Red Hat 9,
1765 Fedora Core 3 and OpenSUSE 11.x.
1767 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1768 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1769 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1770 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1771 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1772 be bound to a specific host interface. If no connection type is set, TCP is
1773 used. This option can be given multiple times.
1775 For example, to redirect host X11 connection from screen 1 to guest
1776 screen 0, use the following:
1778 @example
1779 # on the host
1780 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1781 # this host xterm should open in the guest X11 server
1782 xterm -display :1
1783 @end example
1785 To redirect telnet connections from host port 5555 to telnet port on
1786 the guest, use the following:
1788 @example
1789 # on the host
1790 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1791 telnet localhost 5555
1792 @end example
1794 Then when you use on the host @code{telnet localhost 5555}, you
1795 connect to the guest telnet server.
1797 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1798 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1799 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1800 to the character device @var{dev} or to a program executed by @var{cmd:command}
1801 which gets spawned for each connection. This option can be given multiple times.
1803 You can either use a chardev directly and have that one used throughout QEMU's
1804 lifetime, like in the following example:
1806 @example
1807 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1808 # the guest accesses it
1809 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1810 @end example
1812 Or you can execute a command on every TCP connection established by the guest,
1813 so that QEMU behaves similar to an inetd process for that virtual server:
1815 @example
1817 # and connect the TCP stream to its stdin/stdout
1818 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1819 @end example
1821 @end table
1823 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1824 processed and applied to -net user. Mixing them with the new configuration
1825 syntax gives undefined results. Their use for new applications is discouraged
1826 as they will be removed from future versions.
1828 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1829 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,helper=@var{helper}]
1830 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1832 Use the network script @var{file} to configure it and the network script
1833 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1834 automatically provides one. The default network configure script is
1835 @file{/etc/qemu-ifup} and the default network deconfigure script is
1836 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1837 to disable script execution.
1839 If running QEMU as an unprivileged user, use the network helper
1840 @var{helper} to configure the TAP interface. The default network
1841 helper executable is @file{/path/to/qemu-bridge-helper}.
1843 @option{fd}=@var{h} can be used to specify the handle of an already
1844 opened host TAP interface.
1846 Examples:
1848 @example
1849 #launch a QEMU instance with the default network script
1850 qemu-system-i386 linux.img -net nic -net tap
1851 @end example
1853 @example
1854 #launch a QEMU instance with two NICs, each one connected
1855 #to a TAP device
1856 qemu-system-i386 linux.img \
1857 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1858 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1859 @end example
1861 @example
1862 #launch a QEMU instance with the default network helper to
1863 #connect a TAP device to bridge br0
1864 qemu-system-i386 linux.img \
1866 @end example
1868 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1869 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1870 Connect a host TAP network interface to a host bridge device.
1872 Use the network helper @var{helper} to configure the TAP interface and
1873 attach it to the bridge. The default network helper executable is
1874 @file{/path/to/qemu-bridge-helper} and the default bridge
1875 device is @file{br0}.
1877 Examples:
1879 @example
1880 #launch a QEMU instance with the default network helper to
1881 #connect a TAP device to bridge br0
1882 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1883 @end example
1885 @example
1886 #launch a QEMU instance with the default network helper to
1887 #connect a TAP device to bridge qemubr0
1888 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1889 @end example
1891 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1892 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1894 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1895 machine using a TCP socket connection. If @option{listen} is
1896 specified, QEMU waits for incoming connections on @var{port}
1897 (@var{host} is optional). @option{connect} is used to connect to
1898 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1899 specifies an already opened TCP socket.
1901 Example:
1902 @example
1903 # launch a first QEMU instance
1904 qemu-system-i386 linux.img \
1905 -net nic,macaddr=52:54:00:12:34:56 \
1906 -net socket,listen=:1234
1907 # connect the VLAN 0 of this instance to the VLAN 0
1908 # of the first instance
1909 qemu-system-i386 linux.img \
1910 -net nic,macaddr=52:54:00:12:34:57 \
1911 -net socket,connect=127.0.0.1:1234
1912 @end example
1914 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1915 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1917 Create a VLAN @var{n} shared with another QEMU virtual
1918 machines using a UDP multicast socket, effectively making a bus for
1919 every QEMU with same multicast address @var{maddr} and @var{port}.
1920 NOTES:
1921 @enumerate
1922 @item
1923 Several QEMU can be running on different hosts and share same bus (assuming
1924 correct multicast setup for these hosts).
1925 @item
1926 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1927 @url{http://user-mode-linux.sf.net}.
1928 @item
1929 Use @option{fd=h} to specify an already opened UDP multicast socket.
1930 @end enumerate
1932 Example:
1933 @example
1934 # launch one QEMU instance
1935 qemu-system-i386 linux.img \
1936 -net nic,macaddr=52:54:00:12:34:56 \
1937 -net socket,mcast=230.0.0.1:1234
1939 qemu-system-i386 linux.img \
1940 -net nic,macaddr=52:54:00:12:34:57 \
1941 -net socket,mcast=230.0.0.1:1234
1943 qemu-system-i386 linux.img \
1944 -net nic,macaddr=52:54:00:12:34:58 \
1945 -net socket,mcast=230.0.0.1:1234
1946 @end example
1948 Example (User Mode Linux compat.):
1949 @example
1950 # launch QEMU instance (note mcast address selected
1951 # is UML's default)
1952 qemu-system-i386 linux.img \
1953 -net nic,macaddr=52:54:00:12:34:56 \
1954 -net socket,mcast=239.192.168.1:1102
1955 # launch UML
1956 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
1957 @end example
1959 Example (send packets from host's 1.2.3.4):
1960 @example
1961 qemu-system-i386 linux.img \
1962 -net nic,macaddr=52:54:00:12:34:56 \
1963 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
1964 @end example
1966 @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}]
1967 @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}]
1968 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
1969 protocol to transport Ethernet (and other Layer 2) data frames between
1970 two systems. It is present in routers, firewalls and the Linux kernel
1971 (from version 3.3 onwards).
1973 This transport allows a VM to communicate to another VM, router or firewall directly.
1975 @item src=@var{srcaddr}
1976 source address (mandatory)
1977 @item dst=@var{dstaddr}
1978 destination address (mandatory)
1979 @item udp
1980 select udp encapsulation (default is ip).
1981 @item srcport=@var{srcport}
1982 source udp port.
1983 @item dstport=@var{dstport}
1984 destination udp port.
1985 @item ipv6
1986 force v6, otherwise defaults to v4.
1987 @item rxcookie=@var{rxcookie}
1988 @itemx txcookie=@var{txcookie}
1989 Cookies are a weak form of security in the l2tpv3 specification.
1990 Their function is mostly to prevent misconfiguration. By default they are 32
1991 bit.
1992 @item cookie64
1993 Set cookie size to 64 bit instead of the default 32
1994 @item counter=off
1995 Force a 'cut-down' L2TPv3 with no counter as in
1996 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
1997 @item pincounter=on
1998 Work around broken counter handling in peer. This may also help on
1999 networks which have packet reorder.
2000 @item offset=@var{offset}
2001 Add an extra offset between header and data
2003 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2004 on the remote Linux host 1.2.3.4:
2005 @example
2006 # Setup tunnel on linux host using raw ip as encapsulation
2007 # on 1.2.3.4
2008 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2009 encap udp udp_sport 16384 udp_dport 16384
2010 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2011 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2012 ifconfig vmtunnel0 mtu 1500
2013 ifconfig vmtunnel0 up
2014 brctl addif br-lan vmtunnel0
2017 # on 4.3.2.1
2018 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2020 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
2023 @end example
2025 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2026 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2027 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2028 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2029 and MODE @var{octalmode} to change default ownership and permissions for
2030 communication port. This option is only available if QEMU has been compiled
2031 with vde support enabled.
2033 Example:
2034 @example
2035 # launch vde switch
2036 vde_switch -F -sock /tmp/myswitch
2037 # launch QEMU instance
2038 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2039 @end example
2041 @item -netdev hubport,id=@var{id},hubid=@var{hubid}
2046 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2047 required hub automatically.
2049 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2051 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2052 be a unix domain socket backed one. The vhost-user uses a specifically defined
2053 protocol to pass vhost ioctl replacement messages to an application on the other
2054 end of the socket. On non-MSIX guests, the feature can be forced with
2055 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2056 be created for multiqueue vhost-user.
2058 Example:
2059 @example
2060 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2061 -numa node,memdev=mem \
2062 -chardev socket,path=/path/to/socket \
2063 -netdev type=vhost-user,id=net0,chardev=chr0 \
2064 -device virtio-net-pci,netdev=net0
2065 @end example
2067 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2068 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2069 At most @var{len} bytes (64k by default) per packet are stored. The file format is
2070 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2071 Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2073 @item -net none
2074 Indicate that no network devices should be configured. It is used to
2075 override the default configuration (@option{-net nic -net user}) which
2076 is activated if no @option{-net} options are provided.
2077 ETEXI
2079 STEXI
2080 @end table
2081 ETEXI
2082 DEFHEADING()
2084 DEFHEADING(Character device options:)
2085 STEXI
2087 The general form of a character device option is:
2088 @table @option
2089 ETEXI
2093 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2107 #ifdef _WIN32
2110 #else
2113 #endif
2114 #ifdef CONFIG_BRLAPI
2116 #endif
2117 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2118 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2121 #endif
2122 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2125 #endif
2126 #if defined(CONFIG_SPICE)
2129 #endif
2130 , QEMU_ARCH_ALL
2131 )
2133 STEXI
2134 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2135 @findex -chardev
2136 Backend is one of:
2137 @option{null},
2138 @option{socket},
2139 @option{udp},
2140 @option{msmouse},
2141 @option{vc},
2142 @option{ringbuf},
2143 @option{file},
2144 @option{pipe},
2145 @option{console},
2146 @option{serial},
2147 @option{pty},
2148 @option{stdio},
2149 @option{braille},
2150 @option{tty},
2151 @option{parallel},
2152 @option{parport},
2153 @option{spicevmc}.
2154 @option{spiceport}.
2155 The specific backend will determine the applicable options.
2157 All devices must have an id, which can be any string up to 127 characters long.
2158 It is used to uniquely identify this device in other command line directives.
2160 A character device may be used in multiplexing mode by multiple front-ends.
2161 The key sequence of @key{Control-a} and @key{c} will rotate the input focus
2162 between attached front-ends. Specify @option{mux=on} to enable this mode.
2164 Every backend supports the @option{logfile} option, which supplies the path
2165 to a file to record all data transmitted via the backend. The @option{logappend}
2166 option controls whether the log file will be truncated or appended to when
2167 opened.
2169 Further options to each backend are described below.
2171 @item -chardev null ,id=@var{id}
2172 A void device. This device will not emit any data, and will drop any data it
2173 receives. The null backend does not take any options.
2175 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2177 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2178 unix socket will be created if @option{path} is specified. Behaviour is
2179 undefined if TCP options are specified for a unix socket.
2181 @option{server} specifies that the socket shall be a listening socket.
2183 @option{nowait} specifies that QEMU should not block waiting for a client to
2184 connect to a listening socket.
2186 @option{telnet} specifies that traffic on the socket should interpret telnet
2187 escape sequences.
2189 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2190 the remote end goes away. qemu will delay this many seconds and then attempt
2191 to reconnect. Zero disables reconnecting, and is the default.
2193 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2194 and specifies the id of the TLS credentials to use for the handshake. The
2195 credentials must be previously created with the @option{-object tls-creds}
2196 argument.
2198 TCP and unix socket options are given below:
2200 @table @option
2202 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2204 @option{host} for a listening socket specifies the local address to be bound.
2205 For a connecting socket species the remote host to connect to. @option{host} is
2206 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2208 @option{port} for a listening socket specifies the local port to be bound. For a
2209 connecting socket specifies the port on the remote host to connect to.
2210 @option{port} can be given as either a port number or a service name.
2211 @option{port} is required.
2213 @option{to} is only relevant to listening sockets. If it is specified, and
2214 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2215 to and including @option{to} until it succeeds. @option{to} must be specified
2216 as a port number.
2218 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2219 If neither is specified the socket may use either protocol.
2221 @option{nodelay} disables the Nagle algorithm.
2223 @item unix options: path=@var{path}
2225 @option{path} specifies the local path of the unix socket. @option{path} is
2226 required.
2228 @end table
2230 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2232 Sends all traffic from the guest to a remote host over UDP.
2234 @option{host} specifies the remote host to connect to. If not specified it
2235 defaults to @code{localhost}.
2237 @option{port} specifies the port on the remote host to connect to. @option{port}
2238 is required.
2240 @option{localaddr} specifies the local address to bind to. If not specified it
2241 defaults to @code{0.0.0.0}.
2243 @option{localport} specifies the local port to bind to. If not specified any
2244 available local port will be used.
2246 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2247 If neither is specified the device may use either protocol.
2249 @item -chardev msmouse ,id=@var{id}
2251 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2252 take any options.
2254 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2256 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2257 size.
2259 @option{width} and @option{height} specify the width and height respectively of
2260 the console, in pixels.
2262 @option{cols} and @option{rows} specify that the console be sized to fit a text
2263 console with the given dimensions.
2265 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2267 Create a ring buffer with fixed size @option{size}.
2268 @var{size} must be a power of two, and defaults to @code{64K}).
2270 @item -chardev file ,id=@var{id} ,path=@var{path}
2272 Log all traffic received from the guest to a file.
2274 @option{path} specifies the path of the file to be opened. This file will be
2275 created if it does not already exist, and overwritten if it does. @option{path}
2276 is required.
2278 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2280 Create a two-way connection to the guest. The behaviour differs slightly between
2281 Windows hosts and other hosts:
2283 On Windows, a single duplex pipe will be created at
2286 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2287 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2288 received by the guest. Data written by the guest can be read from
2289 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2290 be present.
2292 @option{path} forms part of the pipe path as described above. @option{path} is
2293 required.
2295 @item -chardev console ,id=@var{id}
2297 Send traffic from the guest to QEMU's standard output. @option{console} does not
2298 take any options.
2300 @option{console} is only available on Windows hosts.
2302 @item -chardev serial ,id=@var{id} ,path=@option{path}
2304 Send traffic from the guest to a serial device on the host.
2306 On Unix hosts serial will actually accept any tty device,
2307 not only serial lines.
2309 @option{path} specifies the name of the serial device to open.
2311 @item -chardev pty ,id=@var{id}
2313 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2314 not take any options.
2316 @option{pty} is not available on Windows hosts.
2318 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2319 Connect to standard input and standard output of the QEMU process.
2321 @option{signal} controls if signals are enabled on the terminal, that includes
2322 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2323 default, use @option{signal=off} to disable it.
2325 @option{stdio} is not available on Windows hosts.
2327 @item -chardev braille ,id=@var{id}
2329 Connect to a local BrlAPI server. @option{braille} does not take any options.
2331 @item -chardev tty ,id=@var{id} ,path=@var{path}
2333 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2334 DragonFlyBSD hosts. It is an alias for @option{serial}.
2336 @option{path} specifies the path to the tty. @option{path} is required.
2338 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2339 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2341 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2343 Connect to a local parallel port.
2345 @option{path} specifies the path to the parallel port device. @option{path} is
2346 required.
2348 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2350 @option{spicevmc} is only available when spice support is built in.
2352 @option{debug} debug level for spicevmc
2354 @option{name} name of spice channel to connect to
2356 Connect to a spice virtual machine channel, such as vdiport.
2358 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2360 @option{spiceport} is only available when spice support is built in.
2362 @option{debug} debug level for spicevmc
2364 @option{name} name of spice port to connect to
2366 Connect to a spice port, allowing a Spice client to handle the traffic
2367 identified by a name (preferably a fqdn).
2368 ETEXI
2370 STEXI
2371 @end table
2372 ETEXI
2373 DEFHEADING()
2375 DEFHEADING(Device URL Syntax:)
2376 STEXI
2378 In addition to using normal file images for the emulated storage devices,
2379 QEMU can also use networked resources such as iSCSI devices. These are
2380 specified using a special URL syntax.
2382 @table @option
2383 @item iSCSI
2384 iSCSI support allows QEMU to access iSCSI resources directly and use as
2385 images for the guest storage. Both disk and cdrom images are supported.
2387 Syntax for specifying iSCSI LUNs is
2388 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2390 By default qemu will use the iSCSI initiator-name
2391 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2392 line or a configuration file.
2394 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2395 stalled requests and force a reestablishment of the session. The timeout
2396 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2397 1.15.0 or greater is required for this feature.
2399 Example (without authentication):
2400 @example
2401 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2402 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2403 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2404 @end example
2406 Example (CHAP username/password via URL):
2407 @example
2408 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2409 @end example
2411 Example (CHAP username/password via environment variables):
2412 @example
2415 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2416 @end example
2418 iSCSI support is an optional feature of QEMU and only available when
2419 compiled and linked against libiscsi.
2420 ETEXI
2427 STEXI
2429 iSCSI parameters such as username and password can also be specified via
2430 a configuration file. See qemu-doc for more information and examples.
2432 @item NBD
2433 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2434 as Unix Domain Sockets.
2436 Syntax for specifying a NBD device using TCP
2437 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2439 Syntax for specifying a NBD device using Unix Domain Sockets
2440 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2443 Example for TCP
2444 @example
2445 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2446 @end example
2448 Example for Unix Domain Sockets
2449 @example
2450 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2451 @end example
2453 @item SSH
2454 QEMU supports SSH (Secure Shell) access to remote disks.
2456 Examples:
2457 @example
2458 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2459 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2460 @end example
2462 Currently authentication must be done using ssh-agent. Other
2463 authentication methods may be supported in future.
2465 @item Sheepdog
2466 Sheepdog is a distributed storage system for QEMU.
2467 QEMU supports using either local sheepdog devices or remote networked
2468 devices.
2470 Syntax for specifying a sheepdog device
2471 @example
2472 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2473 @end example
2475 Example
2476 @example
2477 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2478 @end example
2480 See also @url{http://http://www.osrg.net/sheepdog/}.
2482 @item GlusterFS
2483 GlusterFS is an user space distributed file system.
2484 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2485 TCP, Unix Domain Sockets and RDMA transport protocols.
2487 Syntax for specifying a VM disk image on GlusterFS volume is
2488 @example
2489 gluster[+transport]://[server[:port]]/volname/image[?socket=...]
2490 @end example
2493 Example
2494 @example
2495 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img
2496 @end example
2498 See also @url{http://www.gluster.org}.
2500 @item HTTP/HTTPS/FTP/FTPS/TFTP
2501 QEMU supports read-only access to files accessed over http(s), ftp(s) and tftp.
2503 Syntax using a single filename:
2504 @example
2505 <protocol>://[<username>[:<password>]@@]<host>/<path>
2506 @end example
2508 where:
2509 @table @option
2510 @item protocol
2511 'http', 'https', 'ftp', 'ftps', or 'tftp'.
2513 @item username
2514 Optional username for authentication to the remote server.
2516 @item password
2517 Optional password for authentication to the remote server.
2519 @item host
2520 Address of the remote server.
2522 @item path
2523 Path on the remote server, including any query string.
2524 @end table
2526 The following options are also supported:
2527 @table @option
2528 @item url
2529 The full URL when passing options to the driver explicitly.
2531 @item readahead
2532 The amount of data to read ahead with each range request to the remote server.
2533 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2534 does not have a suffix, it will be assumed to be in bytes. The value must be a
2535 multiple of 512 bytes. It defaults to 256k.
2537 @item sslverify
2538 Whether to verify the remote server's certificate when connecting over SSL. It
2539 can have the value 'on' or 'off'. It defaults to 'on'.
2541 @item cookie
2542 Send this cookie (it can also be a list of cookies separated by ';') with
2543 each outgoing request. Only supported when using protocols such as HTTP
2544 which support cookies, otherwise ignored.
2546 @item timeout
2547 Set the timeout in seconds of the CURL connection. This timeout is the time
2548 that CURL waits for a response from the remote server to get the size of the
2549 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2550 @end table
2552 Note that when passing options to qemu explicitly, @option{driver} is the value
2553 of <protocol>.
2555 Example: boot from a remote Fedora 20 live ISO image
2556 @example
2557 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
2559 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
2560 @end example
2562 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2563 writes, copy-on-read, and a readahead of 64k
2564 @example
2565 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
2568 @end example
2573 @example
2574 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
2577 @end example
2578 ETEXI
2580 STEXI
2581 @end table
2582 ETEXI
2585 STEXI
2586 @table @option
2587 ETEXI
2599 QEMU_ARCH_ALL)
2600 STEXI
2602 @findex -bt
2605 example when emulating a machine with only one HCI built into it, only
2607 logic. The Transport Layer is decided by the machine type. Currently
2608 the machines @code{n800} and @code{n810} have one HCI and all other
2609 machines have none.
2611 @anchor{bt-hcis}
2612 The following three types are recognized:
2614 @table @option
2615 @item -bt hci,null
2616 (default) The corresponding Bluetooth HCI assumes no internal logic
2617 and will not respond to any HCI commands or emit events.
2619 @item -bt hci,host[:@var{id}]
2620 (@code{bluez} only) The corresponding HCI passes commands / events
2621 to / from the physical HCI identified by the name @var{id} (default:
2622 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2623 capable systems like Linux.
2625 @item -bt hci[,vlan=@var{n}]
2626 Add a virtual, standard HCI that will participate in the Bluetooth
2627 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2628 VLANs, devices inside a bluetooth network @var{n} can only communicate
2629 with other devices in the same network (scatternet).
2630 @end table
2632 @item -bt vhci[,vlan=@var{n}]
2633 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2634 to the host bluetooth stack instead of to the emulated target. This
2635 allows the host and target machines to participate in a common scatternet
2636 and communicate. Requires the Linux @code{vhci} driver installed. Can
2637 be used as following:
2639 @example
2640 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2641 @end example
2643 @item -bt device:@var{dev}[,vlan=@var{n}]
2644 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2645 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2646 currently:
2648 @table @option
2649 @item keyboard
2650 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2651 @end table
2652 ETEXI
2654 STEXI
2655 @end table
2656 ETEXI
2657 DEFHEADING()
2659 #ifdef CONFIG_TPM
2660 DEFHEADING(TPM device options:)
2662 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2667 QEMU_ARCH_ALL)
2668 STEXI
2670 The general form of a TPM device option is:
2671 @table @option
2673 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
2674 @findex -tpmdev
2675 Backend type must be:
2676 @option{passthrough}.
2678 The specific backend type will determine the applicable options.
2679 The @code{-tpmdev} option creates the TPM backend and requires a
2680 @code{-device} option that specifies the TPM frontend interface model.
2682 Options to each backend are described below.
2684 Use 'help' to print all available TPM backend types.
2685 @example
2686 qemu -tpmdev help
2687 @end example
2689 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
2691 (Linux-host only) Enable access to the host's TPM using the passthrough
2692 driver.
2694 @option{path} specifies the path to the host's TPM device, i.e., on
2695 a Linux host this would be @code{/dev/tpm0}.
2696 @option{path} is optional and by default @code{/dev/tpm0} is used.
2698 @option{cancel-path} specifies the path to the host TPM device's sysfs
2699 entry allowing for cancellation of an ongoing TPM command.
2700 @option{cancel-path} is optional and by default QEMU will search for the
2701 sysfs entry to use.
2703 Some notes about using the host's TPM with the passthrough driver:
2705 The TPM device accessed by the passthrough driver must not be
2706 used by any other application on the host.
2708 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2709 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2710 TPM again and may therefore not show a TPM-specific menu that would
2711 otherwise allow the user to configure the TPM, e.g., allow the user to
2712 enable/disable or activate/deactivate the TPM.
2713 Further, if TPM ownership is released from within a VM then the host's TPM
2714 will get disabled and deactivated. To enable and activate the
2715 TPM again afterwards, the host has to be rebooted and the user is
2716 required to enter the firmware's menu to enable and activate the TPM.
2717 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2719 To create a passthrough TPM use the following two options:
2720 @example
2721 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2722 @end example
2723 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2724 @code{tpmdev=tpm0} in the device option.
2726 @end table
2728 ETEXI
2730 DEFHEADING()
2732 #endif
2734 DEFHEADING(Linux/Multiboot boot specific:)
2735 STEXI
2737 When using these options, you can use a given Linux or Multiboot
2738 kernel without installing it in the disk image. It can be useful
2739 for easier testing of various kernels.
2741 @table @option
2742 ETEXI
2746 STEXI
2747 @item -kernel @var{bzImage}
2748 @findex -kernel
2749 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2750 or in multiboot format.
2751 ETEXI
2755 STEXI
2756 @item -append @var{cmdline}
2757 @findex -append
2758 Use @var{cmdline} as kernel command line
2759 ETEXI
2763 STEXI
2764 @item -initrd @var{file}
2765 @findex -initrd
2766 Use @var{file} as initial ram disk.
2770 This syntax is only available with multiboot.
2772 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2773 first module.
2774 ETEXI
2778 STEXI
2779 @item -dtb @var{file}
2780 @findex -dtb
2781 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2782 on boot.
2783 ETEXI
2785 STEXI
2786 @end table
2787 ETEXI
2788 DEFHEADING()
2790 DEFHEADING(Debug/Expert options:)
2791 STEXI
2792 @table @option
2793 ETEXI
2800 QEMU_ARCH_ALL)
2801 STEXI
2802 @item -fw_cfg [name=]@var{name},file=@var{file}
2803 @findex -fw_cfg
2804 Add named fw_cfg entry from file. @var{name} determines the name of
2805 the entry in the fw_cfg file directory exposed to the guest.
2807 @item -fw_cfg [name=]@var{name},string=@var{str}
2808 Add named fw_cfg entry from string.
2809 ETEXI
2813 QEMU_ARCH_ALL)
2814 STEXI
2815 @item -serial @var{dev}
2816 @findex -serial
2817 Redirect the virtual serial port to host character device
2818 @var{dev}. The default device is @code{vc} in graphical mode and
2819 @code{stdio} in non graphical mode.
2821 This option can be used several times to simulate up to 4 serial
2822 ports.
2824 Use @code{-serial none} to disable all serial ports.
2826 Available character devices are:
2827 @table @option
2828 @item vc[:@var{W}x@var{H}]
2829 Virtual console. Optionally, a width and height can be given in pixel with
2830 @example
2831 vc:800x600
2832 @end example
2833 It is also possible to specify width or height in characters:
2834 @example
2835 vc:80Cx24C
2836 @end example
2837 @item pty
2838 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
2839 @item none
2840 No device is allocated.
2841 @item null
2842 void device
2843 @item chardev:@var{id}
2844 Use a named character device defined with the @code{-chardev} option.
2845 @item /dev/XXX
2846 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2847 parameters are set according to the emulated ones.
2848 @item /dev/parport@var{N}
2849 [Linux only, parallel port only] Use host parallel port
2850 @var{N}. Currently SPP and EPP parallel port features can be used.
2851 @item file:@var{filename}
2852 Write output to @var{filename}. No character can be read.
2853 @item stdio
2854 [Unix only] standard input/output
2855 @item pipe:@var{filename}
2856 name pipe @var{filename}
2857 @item COM@var{n}
2858 [Windows only] Use host serial port @var{n}
2859 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
2860 This implements UDP Net Console.
2861 When @var{remote_host} or @var{src_ip} are not specified
2862 they default to @code{0.0.0.0}.
2863 When not using a specified @var{src_port} a random port is automatically chosen.
2865 If you just want a simple readonly console you can use @code{netcat} or
2866 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
2867 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
2868 will appear in the netconsole session.
2870 If you plan to send characters back via netconsole or you want to stop
2871 and start QEMU a lot of times, you should have QEMU use the same
2872 source port each time by using something like @code{-serial
2873 udp::4555@@:4556} to QEMU. Another approach is to use a patched
2874 version of netcat which can listen to a TCP port and send and receive
2875 characters via udp. If you have a patched version of netcat which
2876 activates telnet remote echo and single char transfer, then you can
2877 use the following options to step up a netcat redirector to allow
2878 telnet on port 5555 to access the QEMU port.
2879 @table @code
2880 @item QEMU Options:
2881 -serial udp::4555@@:4556
2882 @item netcat options:
2883 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
2884 @item telnet options:
2885 localhost 5555
2886 @end table
2888 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
2889 The TCP Net Console has two modes of operation. It can send the serial
2890 I/O to a location or wait for a connection from a location. By default
2891 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
2892 the @var{server} option QEMU will wait for a client socket application
2893 to connect to the port before continuing, unless the @code{nowait}
2894 option was specified. The @code{nodelay} option disables the Nagle buffering
2895 algorithm. The @code{reconnect} option only applies if @var{noserver} is
2896 set, if the connection goes down it will attempt to reconnect at the
2897 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
2898 one TCP connection at a time is accepted. You can use @code{telnet} to
2899 connect to the corresponding character device.
2900 @table @code
2901 @item Example to send tcp console to 192.168.0.2 port 4444
2902 -serial tcp:192.168.0.2:4444
2903 @item Example to listen and wait on port 4444 for connection
2904 -serial tcp::4444,server
2905 @item Example to not wait and listen on ip 192.168.0.100 port 4444
2906 -serial tcp:192.168.0.100:4444,server,nowait
2907 @end table
2909 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
2910 The telnet protocol is used instead of raw tcp sockets. The options
2911 work the same as if you had specified @code{-serial tcp}. The
2912 difference is that the port acts like a telnet server or client using
2913 telnet option negotiation. This will also allow you to send the
2914 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
2915 sequence. Typically in unix telnet you do it with Control-] and then
2918 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
2919 A unix domain socket is used instead of a tcp socket. The option works the
2920 same as if you had specified @code{-serial tcp} except the unix domain socket
2921 @var{path} is used for connections.
2923 @item mon:@var{dev_string}
2924 This is a special option to allow the monitor to be multiplexed onto
2925 another serial port. The monitor is accessed with key sequence of
2926 @key{Control-a} and then pressing @key{c}.
2927 @var{dev_string} should be any one of the serial devices specified
2928 above. An example to multiplex the monitor onto a telnet server
2929 listening on port 4444 would be:
2930 @table @code
2931 @item -serial mon:telnet::4444,server,nowait
2932 @end table
2933 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
2934 QEMU any more but will be passed to the guest instead.
2936 @item braille
2937 Braille device. This will use BrlAPI to display the braille output on a real
2938 or fake device.
2940 @item msmouse
2941 Three button serial mouse. Configure the guest to use Microsoft protocol.
2942 @end table
2943 ETEXI
2947 QEMU_ARCH_ALL)
2948 STEXI
2949 @item -parallel @var{dev}
2950 @findex -parallel
2951 Redirect the virtual parallel port to host device @var{dev} (same
2952 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
2953 be used to use hardware devices connected on the corresponding host
2954 parallel port.
2956 This option can be used several times to simulate up to 3 parallel
2957 ports.
2959 Use @code{-parallel none} to disable all parallel ports.
2960 ETEXI
2964 QEMU_ARCH_ALL)
2965 STEXI
2966 @item -monitor @var{dev}
2967 @findex -monitor
2968 Redirect the monitor to host device @var{dev} (same devices as the
2969 serial port).
2970 The default device is @code{vc} in graphical mode and @code{stdio} in
2971 non graphical mode.
2972 Use @code{-monitor none} to disable the default monitor.
2973 ETEXI
2976 QEMU_ARCH_ALL)
2977 STEXI
2978 @item -qmp @var{dev}
2979 @findex -qmp
2980 Like -monitor but opens in 'control' mode.
2981 ETEXI
2984 QEMU_ARCH_ALL)
2985 STEXI
2986 @item -qmp-pretty @var{dev}
2987 @findex -qmp-pretty
2988 Like -qmp but uses pretty JSON formatting.
2989 ETEXI
2993 STEXI
2994 @item -mon [chardev=]name[,mode=readline|control][,default]
2995 @findex -mon
2996 Setup monitor on chardev @var{name}.
2997 ETEXI
3001 QEMU_ARCH_ALL)
3002 STEXI
3003 @item -debugcon @var{dev}
3004 @findex -debugcon
3005 Redirect the debug console to host device @var{dev} (same devices as the
3006 serial port). The debug console is an I/O port which is typically port
3007 0xe9; writing to that I/O port sends output to this device.
3008 The default device is @code{vc} in graphical mode and @code{stdio} in
3009 non graphical mode.
3010 ETEXI
3014 STEXI
3015 @item -pidfile @var{file}
3016 @findex -pidfile
3017 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3018 from a script.
3019 ETEXI
3023 STEXI
3024 @item -singlestep
3025 @findex -singlestep
3026 Run the emulation in single step mode.
3027 ETEXI
3031 QEMU_ARCH_ALL)
3032 STEXI
3033 @item -S
3034 @findex -S
3035 Do not start CPU at startup (you must type 'c' in the monitor).
3036 ETEXI
3042 QEMU_ARCH_ALL)
3043 STEXI
3044 @item -realtime mlock=on|off
3045 @findex -realtime
3046 Run qemu with realtime features.
3047 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3048 (enabled by default).
3049 ETEXI
3053 STEXI
3054 @item -gdb @var{dev}
3055 @findex -gdb
3056 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3057 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3058 stdio are reasonable use case. The latter is allowing to start QEMU from
3059 within gdb and establish the connection via a pipe:
3060 @example
3061 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3062 @end example
3063 ETEXI
3067 QEMU_ARCH_ALL)
3068 STEXI
3069 @item -s
3070 @findex -s
3071 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3072 (@pxref{gdb_usage}).
3073 ETEXI
3077 QEMU_ARCH_ALL)
3078 STEXI
3079 @item -d @var{item1}[,...]
3080 @findex -d
3081 Enable logging of specified items. Use '-d help' for a list of log items.
3082 ETEXI
3086 QEMU_ARCH_ALL)
3087 STEXI
3088 @item -D @var{logfile}
3089 @findex -D
3090 Output log in @var{logfile} instead of to stderr
3091 ETEXI
3095 QEMU_ARCH_ALL)
3096 STEXI
3097 @item -L @var{path}
3098 @findex -L
3099 Set the directory for the BIOS, VGA BIOS and keymaps.
3100 ETEXI
3104 STEXI
3105 @item -bios @var{file}
3106 @findex -bios
3107 Set the filename for the BIOS.
3108 ETEXI
3112 STEXI
3113 @item -enable-kvm
3114 @findex -enable-kvm
3115 Enable KVM full virtualization support. This option is only available
3116 if KVM support is enabled when compiling.
3117 ETEXI
3124 QEMU_ARCH_ALL)
3128 QEMU_ARCH_ALL)
3129 STEXI
3130 @item -xen-domid @var{id}
3131 @findex -xen-domid
3132 Specify xen guest domain @var{id} (XEN only).
3133 @item -xen-create
3134 @findex -xen-create
3135 Create domain using xen hypercalls, bypassing xend.
3136 Warning: should not be used when xend is in use (XEN only).
3137 @item -xen-attach
3138 @findex -xen-attach
3139 Attach to existing xen domain.
3140 xend will use this when starting QEMU (XEN only).
3141 ETEXI
3145 STEXI
3146 @item -no-reboot
3147 @findex -no-reboot
3148 Exit instead of rebooting.
3149 ETEXI
3153 STEXI
3154 @item -no-shutdown
3155 @findex -no-shutdown
3156 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3157 This allows for instance switching to monitor to commit changes to the
3158 disk image.
3159 ETEXI
3164 QEMU_ARCH_ALL)
3165 STEXI
3166 @item -loadvm @var{file}
3167 @findex -loadvm
3168 Start right away with a saved state (@code{loadvm} in monitor)
3169 ETEXI
3171 #ifndef _WIN32
3174 #endif
3175 STEXI
3176 @item -daemonize
3177 @findex -daemonize
3178 Daemonize the QEMU process after initialization. QEMU will not detach from
3179 standard IO until it is ready to receive connections on any of its devices.
3180 This option is a useful way for external programs to launch QEMU without having
3181 to cope with initialization race conditions.
3182 ETEXI
3186 QEMU_ARCH_ALL)
3187 STEXI
3188 @item -option-rom @var{file}
3189 @findex -option-rom
3190 Load the contents of @var{file} as an option ROM.
3191 This option is useful to load things like EtherBoot.
3192 ETEXI
3194 HXCOMM Silently ignored for compatibility
3197 HXCOMM Options deprecated by -rtc
3204 QEMU_ARCH_ALL)
3206 STEXI
3208 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3209 @findex -rtc
3210 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3211 UTC or local time, respectively. @code{localtime} is required for correct date in
3212 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3213 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3215 By default the RTC is driven by the host system time. This allows using of the
3216 RTC as accurate reference clock inside the guest, specifically if the host
3217 time is smoothly following an accurate external reference clock, e.g. via NTP.
3218 If you want to isolate the guest time from the host, you can set @option{clock}
3219 to @code{rt} instead. To even prevent it from progressing during suspension,
3220 you can set it to @code{vm}.
3222 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3223 specifically with Windows' ACPI HAL. This option will try to figure out how
3224 many timer interrupts were not processed by the Windows guest and will
3225 re-inject them.
3226 ETEXI
3233 STEXI
3234 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}]
3235 @findex -icount
3236 Enable virtual instruction counter. The virtual cpu will execute one
3237 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3238 then the virtual cpu speed will be automatically adjusted to keep virtual
3239 time within a few seconds of real time.
3241 When the virtual cpu is sleeping, the virtual time will advance at default
3242 speed unless @option{sleep=no} is specified.
3243 With @option{sleep=no}, the virtual time will jump to the next timer deadline
3244 instantly whenever the virtual cpu goes to sleep mode and will not advance
3245 if no timer is enabled. This behavior give deterministic execution times from
3246 the guest point of view.
3248 Note that while this option can give deterministic behavior, it does not
3249 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3250 order cores with complex cache hierarchies. The number of instructions
3251 executed often has little or no correlation with actual performance.
3253 @option{align=on} will activate the delay algorithm which will try
3254 to synchronise the host clock and the virtual clock. The goal is to
3255 have a guest running at the real frequency imposed by the shift option.
3256 Whenever the guest clock is behind the host clock and if
3257 @option{align=on} is specified then we print a message to the user
3258 to inform about the delay.
3259 Currently this option does not work when @option{shift} is @code{auto}.
3260 Note: The sync algorithm will work for those shift values for which
3261 the guest clock runs ahead of the host clock. Typically this happens
3262 when the shift value is high (how high depends on the host machine).
3264 When @option{rr} option is specified deterministic record/replay is enabled.
3265 Replay log is written into @var{filename} file in record mode and
3266 read from this file in replay mode.
3267 ETEXI
3272 QEMU_ARCH_ALL)
3273 STEXI
3274 @item -watchdog @var{model}
3275 @findex -watchdog
3276 Create a virtual hardware watchdog device. Once enabled (by a guest
3277 action), the watchdog must be periodically polled by an agent inside
3278 the guest or else the guest will be restarted. Choose a model for
3279 which your guest has drivers.
3281 The @var{model} is the model of hardware watchdog to emulate. Use
3282 @code{-watchdog help} to list available hardware models. Only one
3283 watchdog can be enabled for a guest.
3285 The following models may be available:
3286 @table @option
3287 @item ib700
3288 iBASE 700 is a very simple ISA watchdog with a single timer.
3289 @item i6300esb
3290 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3291 dual-timer watchdog.
3292 @item diag288
3293 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3294 (currently KVM only).
3295 @end table
3296 ETEXI
3301 QEMU_ARCH_ALL)
3302 STEXI
3303 @item -watchdog-action @var{action}
3304 @findex -watchdog-action
3306 The @var{action} controls what QEMU will do when the watchdog timer
3307 expires.
3308 The default is
3309 @code{reset} (forcefully reset the guest).
3310 Other possible actions are:
3311 @code{shutdown} (attempt to gracefully shutdown the guest),
3312 @code{poweroff} (forcefully poweroff the guest),
3313 @code{pause} (pause the guest),
3314 @code{debug} (print a debug message and continue), or
3315 @code{none} (do nothing).
3317 Note that the @code{shutdown} action requires that the guest responds
3318 to ACPI signals, which it may not be able to do in the sort of
3319 situations where the watchdog would have expired, and thus
3320 @code{-watchdog-action shutdown} is not recommended for production use.
3322 Examples:
3324 @table @code
3325 @item -watchdog i6300esb -watchdog-action pause
3326 @itemx -watchdog ib700
3327 @end table
3328 ETEXI
3332 QEMU_ARCH_ALL)
3333 STEXI
3335 @item -echr @var{numeric_ascii_value}
3336 @findex -echr
3337 Change the escape character used for switching to the monitor when using
3338 monitor and serial sharing. The default is @code{0x01} when using the
3339 @code{-nographic} option. @code{0x01} is equal to pressing
3340 @code{Control-a}. You can select a different character from the ascii
3341 control keys where 1 through 26 map to Control-a through Control-z. For
3342 instance you could use the either of the following to change the escape
3343 character to Control-t.
3344 @table @code
3345 @item -echr 0x14
3346 @itemx -echr 20
3347 @end table
3348 ETEXI
3353 STEXI
3354 @item -virtioconsole @var{c}
3355 @findex -virtioconsole
3356 Set virtio console.
3358 This option is maintained for backward compatibility.
3360 Please use @code{-device virtconsole} for the new way of invocation.
3361 ETEXI
3365 STEXI
3366 @item -show-cursor
3367 @findex -show-cursor
3368 Show cursor.
3369 ETEXI
3373 STEXI
3374 @item -tb-size @var{n}
3375 @findex -tb-size
3376 Set TB size.
3377 ETEXI
3391 QEMU_ARCH_ALL)
3392 STEXI
3393 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3394 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3395 @findex -incoming
3396 Prepare for incoming migration, listen on a given tcp port.
3398 @item -incoming unix:@var{socketpath}
3399 Prepare for incoming migration, listen on a given unix socket.
3401 @item -incoming fd:@var{fd}
3402 Accept incoming migration from a given filedescriptor.
3404 @item -incoming exec:@var{cmdline}
3405 Accept incoming migration as an output from specified external command.
3407 @item -incoming defer
3408 Wait for the URI to be specified via migrate_incoming. The monitor can
3409 be used to change settings (such as migration parameters) prior to issuing
3410 the migrate_incoming to allow the migration to begin.
3411 ETEXI
3415 STEXI
3416 @item -nodefaults
3417 @findex -nodefaults
3422 ETEXI
3424 #ifndef _WIN32
3427 QEMU_ARCH_ALL)
3428 #endif
3429 STEXI
3431 @findex -chroot
3432 Immediately before starting guest execution, chroot to the specified
3434 ETEXI
3436 #ifndef _WIN32
3439 QEMU_ARCH_ALL)
3440 #endif
3441 STEXI
3443 @findex -runas
3445 to the specified user.
3446 ETEXI
3451 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3452 STEXI
3456 ETEXI
3459 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3460 QEMU_ARCH_MIPS)
3461 STEXI
3462 @item -semihosting
3463 @findex -semihosting
3465 ETEXI
3469 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3470 QEMU_ARCH_MIPS)
3471 STEXI
3475 @table @option
3481 Allows the user to pass input arguments, and can be used multiple times to build
3486 @end table
3487 ETEXI
3490 STEXI
3494 ETEXI
3498 QEMU_ARCH_ALL)
3499 STEXI
3501 @findex -sandbox
3504 ETEXI
3508 STEXI
3510 @findex -readconfig
3512 QEMU process with many command line options but you don't want to exceed the command line
3513 character limit.
3514 ETEXI
3515 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3518 STEXI
3519 @item -writeconfig @var{file}
3520 @findex -writeconfig
3521 Write device configuration to @var{file}. The @var{file} can be either filename to save
3522 command line and device configuration into file or dash @code{-}) character to print the
3523 output to stdout. This can be later used as input file for @code{-readconfig} option.
3524 ETEXI
3525 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
3528 QEMU_ARCH_ALL)
3529 STEXI
3530 @item -nodefconfig
3531 @findex -nodefconfig
3532 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
3533 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
3534 ETEXI
3535 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3538 QEMU_ARCH_ALL)
3539 STEXI
3540 @item -no-user-config
3541 @findex -no-user-config
3542 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3545 ETEXI
3549 QEMU_ARCH_ALL)
3550 STEXI
3552 HXCOMM HX does not support conditional compilation of text.
3556 Specify tracing options.
3558 @table @option
3578 This option is only available if QEMU has been compiled with
3580 @end table
3581 ETEXI
3583 HXCOMM Internal use
3587 #ifdef __linux__
3590 QEMU_ARCH_ALL)
3591 #endif
3592 STEXI
3596 ETEXI
3601 HXCOMM Deprecated by kvm-pit driver properties
3618 QEMU_ARCH_ALL)
3619 STEXI
3621 @findex -msg
3623 ETEXI
3631 QEMU_ARCH_ALL)
3632 STEXI
3637 ETEXI
3647 QEMU_ARCH_ALL)
3648 STEXI
3650 @findex -object
3656 @table @option
3658 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
3660 Creates a memory file backend object, which can be used to back
3662 unique ID that will be used to reference this memory region
3664 option provides the size of the memory region, and accepts
3666 the path to either a shared memory or huge page filesystem mount.
3673 Creates a random number generator backend which obtains entropy from
3681 Creates a random number generator backend which obtains entropy from
3683 a unique ID that will be used to reference this entropy backend from
3685 the unique ID of a character device backend that provides the connection
3686 to the RNG daemon.
3688 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
3690 Creates a TLS anonymous credentials object, which can be used to provide
3692 ID which network backends will use to access the credentials. The
3694 on whether the QEMU network backend that uses the credentials will be
3703 a set of DH parameters at startup. This is a computationally
3704 expensive operation that consumes random pool entropy, so it is
3705 recommended that a persistent set of parameters be generated
3706 upfront and saved.
3708 @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}
3710 Creates a TLS anonymous credentials object, which can be used to provide
3712 ID which network backends will use to access the credentials. The
3714 on whether the QEMU network backend that uses the credentials will be
3718 must be provided with valid client certificates too.
3724 a set of DH parameters at startup. This is a computationally
3725 expensive operation that consumes random pool entropy, so it is
3726 recommended that a persistent set of parameters be generated
3727 upfront and saved.
3729 For x509 certificate credentials the directory will contain further files
3730 providing the x509 certificates. The certificates must be stored
3741 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}]
3744 packets arriving in a given interval on netdev @var{netdevid} are delayed
3745 until the end of the interval. Interval is in microseconds.
3747 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
3749 @option{all}: the filter is attached both to the receive and the transmit
3750 queue of the netdev (default).
3752 @option{rx}: the filter is attached to the receive queue of the netdev,
3753 where it will receive packets sent to the netdev.
3755 @option{tx}: the filter is attached to the transmit queue of the netdev,
3756 where it will receive packets sent by the netdev.
3758 @item -object filter-dump,id=@var{id},netdev=@var{dev},file=@var{filename}][,maxlen=@var{len}]
3760 Dump the network traffic on netdev @var{dev} to the file specified by
3761 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
3762 The file format is libpcap, so it can be analyzed with tools such as tcpdump
3763 or Wireshark.
3765 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3766 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
3768 Defines a secret to store a password, encryption key, or some other sensitive
3769 data. The sensitive data can either be passed directly via the @var{data}
3770 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
3771 parameter is insecure unless the sensitive data is encrypted.
3773 The sensitive data can be provided in raw format (the default), or base64.
3774 When encoded as JSON, the raw format only supports valid UTF-8 characters,
3775 so base64 is recommended for sending binary data. QEMU will convert from
3776 which ever format is provided to the format it needs internally. eg, an
3777 RBD password can be provided in raw format, even though it will be base64
3778 encoded when passed onto the RBD sever.
3780 For added protection, it is possible to encrypt the data associated with
3781 a secret using the AES-256-CBC cipher. Use of encryption is indicated
3782 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
3783 parameter provides the ID of a previously defined secret that contains
3784 the AES-256 decryption key. This key should be 32-bytes long and be
3785 base64 encoded. The @var{iv} parameter provides the random initialization
3786 vector used for encryption of this particular secret and should be a
3787 base64 encrypted string of the 32-byte IV.
3789 The simplest (insecure) usage is to provide the secret inline
3791 @example
3793 # $QEMU -object secret,id=sec0,data=letmein,format=raw
3795 @end example
3797 The simplest secure usage is to provide the secret via a file
3799 # echo -n "letmein" > mypasswd.txt
3800 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
3802 For greater security, AES-256-CBC should be used. To illustrate usage,
3803 consider the openssl command line tool which can encrypt the data. Note
3804 that when encrypting, the plaintext must be padded to the cipher block
3805 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
3807 First a master key needs to be created in base64 encoding:
3809 @example
3810 # openssl rand -base64 32 > key.b64
3812 @end example
3814 Each secret to be encrypted needs to have a random initialization vector
3815 generated. These do not need to be kept secret
3817 @example
3818 # openssl rand -base64 16 > iv.b64
3820 @end example
3822 The secret to be defined can now be encrypted, in this case we're
3823 telling openssl to base64 encode the result, but it could be left
3826 @example
3829 @end example
3832 and specify that to be used to decrypt the user password. Pass the
3835 @example
3836 # $QEMU \
3840 @end example
3842 @end table
3844 ETEXI
3848 STEXI
3849 @end table
3850 ETEXI