| blob | ad2f8fc873d242f292f4b010623e851ae6edae87 |
2 HXCOMM Text between STEXI and ETEXI are copied to texi version and
3 HXCOMM discarded from C version
6 HXCOMM architectures.
10 STEXI
11 @table @option
12 ETEXI
16 STEXI
17 @item -h
18 @findex -h
19 Display help and exit
20 ETEXI
24 STEXI
25 @item -version
26 @findex -version
27 Display version information and exit
28 ETEXI
46 QEMU_ARCH_ALL)
47 STEXI
49 @findex -machine
52 @table @option
57 to initialize.
58 @item kernel_irqchip=on|off
60 @item gfx_passthru=on|off
62 @item vmport=on|off|auto
65 is on.
66 @item kvm_shadow_mem=size
67 Defines the size of the KVM shadow MMU.
76 controls whether AES wrapping keys will be created to allow
80 controls whether DEA wrapping keys will be created to allow
82 @item nvdimm=on|off
84 @end table
85 ETEXI
87 HXCOMM Deprecated by -machine
92 STEXI
94 @findex -cpu
96 ETEXI
106 QEMU_ARCH_ALL)
107 STEXI
108 @item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
109 @findex -smp
117 specifies the maximum number of hotpluggable CPUs.
118 ETEXI
123 STEXI
126 @findex -numa
130 resources. That is, it just assigns existing resources to NUMA nodes. This
131 means that one still has to use the @option{-m}, @option{-smp} options
132 to allocate RAM and VCPUs respectively, and possibly @option{-object}
133 to specify the memory backend for the @samp{memdev} suboption.
135 @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore, if one
136 node uses @samp{memdev}, all of them have to use it.
137 ETEXI
139 DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
142 STEXI
143 @item -add-fd fd=@var{fd},set=@var{set}[,opaque=@var{opaque}]
144 @findex -add-fd
146 Add a file descriptor to an fd set. Valid options are:
148 @table @option
149 @item fd=@var{fd}
150 This option defines the file descriptor of which a duplicate is added to fd set.
151 The file descriptor cannot be stdin, stdout, or stderr.
152 @item set=@var{set}
153 This option defines the ID of the fd set to add the file descriptor to.
154 @item opaque=@var{opaque}
155 This option defines a free-form string that can be used to describe @var{fd}.
156 @end table
158 You can open an image using pre-opened file descriptors from an fd set:
159 @example
160 qemu-system-i386
161 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
162 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
163 -drive file=/dev/fdset/2,index=0,media=disk
164 @end example
165 ETEXI
167 DEF("set", HAS_ARG, QEMU_OPTION_set,
171 STEXI
172 @item -set @var{group}.@var{id}.@var{arg}=@var{value}
173 @findex -set
174 Set parameter @var{arg} for item @var{id} of type @var{group}
175 ETEXI
177 DEF("global", HAS_ARG, QEMU_OPTION_global,
181 QEMU_ARCH_ALL)
182 STEXI
183 @item -global @var{driver}.@var{prop}=@var{value}
184 @itemx -global driver=@var{driver},property=@var{property},value=@var{value}
185 @findex -global
188 @example
189 qemu-system-i386 -global ide-drive.physical_block_size=4096 -drive file=file,if=ide,index=0,media=disk
190 @end example
193 created automatically by the machine model. To create a device which is not
199 ETEXI
208 QEMU_ARCH_ALL)
209 STEXI
210 @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]
211 @findex -boot
216 particular boot order only on the first startup, specify it via
232 system support it.
235 supports it. This only effects when boot priority is changed by
238 @example
245 @end example
248 use is discouraged as it may be removed from future versions.
249 ETEXI
258 QEMU_ARCH_ALL)
259 STEXI
261 @findex -m
265 could be used to set amount of hotpluggable memory slots and maximum amount of
272 @example
274 @end example
277 be enabled and the guest startup RAM will never increase.
278 ETEXI
280 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
282 STEXI
283 @item -mem-path @var{path}
284 @findex -mem-path
285 Allocate guest RAM from a temporarily created file in @var{path}.
286 ETEXI
288 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
290 QEMU_ARCH_ALL)
291 STEXI
292 @item -mem-prealloc
293 @findex -mem-prealloc
294 Preallocate memory when using -mem-path.
295 ETEXI
297 DEF("k", HAS_ARG, QEMU_OPTION_k,
299 QEMU_ARCH_ALL)
300 STEXI
301 @item -k @var{language}
302 @findex -k
303 Use keyboard layout @var{language} (for example @code{fr} for
304 French). This option is only needed where it is not easy to get raw PC
305 keycodes (e.g. on Macs, with some X11 servers or with a VNC or curses
307 hosts.
309 The available layouts are:
310 @example
314 @end example
317 ETEXI
322 QEMU_ARCH_ALL)
323 STEXI
327 parameters.
328 ETEXI
335 STEXI
337 @findex -soundhw
339 available sound hardware.
341 @example
348 @end example
350 Note that Linux's i810_audio OSS kernel (for AC97) module might
351 require manually specifying clocking.
353 @example
354 modprobe i810_audio clocking=48000
355 @end example
356 ETEXI
358 DEF("balloon", HAS_ARG, QEMU_OPTION_balloon,
362 STEXI
363 @item -balloon none
364 @findex -balloon
365 Disable balloon device.
366 @item -balloon virtio[,addr=@var{addr}]
367 Enable virtio balloon device (default), optionally with PCI address
368 @var{addr}.
369 ETEXI
371 DEF("device", HAS_ARG, QEMU_OPTION_device,
377 QEMU_ARCH_ALL)
378 STEXI
379 @item -device @var{driver}[,@var{prop}[=@var{value}][,...]]
380 @findex -device
381 Add device @var{driver}. @var{prop}=@var{value} sets driver
382 properties. Valid properties depend on the driver. To get help on
383 possible drivers and properties, use @code{-device help} and
384 @code{-device @var{driver},help}.
386 Some drivers are:
387 @item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}]
389 Add an IPMI BMC. This is a simulation of a hardware management
390 interface processor that normally sits on a system. It provides
391 a watchdog and the ability to reset and power control the system.
392 You need to connect this to an IPMI interface to make it useful
394 The IPMI slave address to use for the BMC. The default is 0x20.
395 This address is the BMC's address on the I2C network of management
397 it.
399 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
401 Add a connection to an external IPMI BMC simulator. Instead of
402 locally emulating the BMC like the above item, instead connect
403 to an external entity that provides the IPMI services.
405 A connection is made to an external BMC simulator. If you do this, it
406 is strongly recommended that you use the "reconnect=" chardev option
407 to reconnect to the simulator if the connection is lost. Note that if
408 this is not used carefully, it can be a security issue, as the
409 interface has the ability to send resets, NMIs, and power off the VM.
411 on a secure port on localhost, so neither the simulator nor QEMU is
412 exposed to any outside network.
419 Add a KCS IPMI interafce on the ISA bus. This also adds a
422 @table @option
430 @end table
437 ETEXI
445 QEMU_ARCH_ALL)
446 STEXI
448 @findex -name
453 Naming of individual threads can also be enabled on Linux to aid debugging.
454 ETEXI
459 STEXI
461 @findex -uuid
462 Set system UUID.
463 ETEXI
465 STEXI
466 @end table
467 ETEXI
471 STEXI
472 @table @option
473 ETEXI
478 STEXI
481 @findex -fda
482 @findex -fdb
484 ETEXI
492 STEXI
497 @findex -hda
498 @findex -hdb
499 @findex -hdc
500 @findex -hdd
502 ETEXI
506 QEMU_ARCH_ALL)
507 STEXI
509 @findex -cdrom
513 ETEXI
530 STEXI
532 @findex -drive
536 @table @option
542 Special files such as iSCSI devices can be specified using protocol
548 These options define where is connected the drive by defining the bus number and
549 the unit id.
561 @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
563 @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO.
565 @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.
569 an untrusted format header.
571 This option specifies the serial number to assign to the device.
573 Specify the controller's PCI address (if=virtio only).
574 @item werror=@var{action},rerror=@var{action}
575 Specify which @var{action} to take on write and read errors. Valid actions are:
576 "ignore" (ignore the error and try to continue), "stop" (pause QEMU),
577 "report" (report the error to the guest), "enospc" (pause QEMU only if the
578 host disk is full; report the error to the guest otherwise).
579 The default setting is @option{werror=enospc} and @option{rerror=report}.
580 @item readonly
581 Open drive @option{file} as read-only. Guest write attempts will fail.
582 @item copy-on-read=@var{copy-on-read}
583 @var{copy-on-read} is "on" or "off" and enables whether to copy read backing
584 file sectors into the image file.
585 @item detect-zeroes=@var{detect-zeroes}
586 @var{detect-zeroes} is "off", "on" or "unmap" and enables the automatic
587 conversion of plain zero writes by the OS to driver specific optimized
588 zero write commands. You may even choose "unmap" if @var{discard} is set
589 to "unmap" to allow a zero write to be converted to an UNMAP operation.
590 @end table
592 By default, the @option{cache=writeback} mode is used. It will report data
593 writes as completed as soon as the data is present in the host page cache.
594 This is safe as long as your guest OS makes sure to correctly flush disk caches
595 where needed. If your guest OS does not handle volatile disk write caches
596 correctly and your host crashes or loses power, then the guest may experience
597 data corruption.
599 For such guests, you should consider using @option{cache=writethrough}. This
600 means that the host page cache will be used to read and write data, but write
601 notification will be sent to the guest only after QEMU has made sure to flush
602 each write to the disk. Be aware that this has a major impact on performance.
604 The host page cache can be avoided entirely with @option{cache=none}. This will
607 the guest OS must handle the disk write cache correctly in order to avoid data
608 corruption on host crashes.
610 The host page cache can be avoided while only sending write notifications to
611 the guest when the data has been flushed to the disk using
615 @option{cache=unsafe}. This option tells QEMU that it never needs to write any
616 data to the disk but can instead keep things in cache. If anything goes wrong,
617 like your host losing power, the disk storage getting disconnected accidentally,
618 etc. your image will most probably be rendered unusable. When using
619 the @option{-snapshot} option, unsafe caching is always used.
621 Copy-on-read avoids accessing the same backing file sectors repeatedly and is
622 useful when the backing file is over a slow network. By default copy-on-read
623 is off.
625 Instead of @option{-cdrom} you can use:
626 @example
627 qemu-system-i386 -drive file=file,index=2,media=cdrom
628 @end example
630 Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
631 use:
632 @example
633 qemu-system-i386 -drive file=file,index=0,media=disk
634 qemu-system-i386 -drive file=file,index=1,media=disk
635 qemu-system-i386 -drive file=file,index=2,media=disk
636 qemu-system-i386 -drive file=file,index=3,media=disk
637 @end example
639 You can open an image using pre-opened file descriptors from an fd set:
640 @example
641 qemu-system-i386
642 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
643 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
644 -drive file=/dev/fdset/2,index=0,media=disk
645 @end example
647 You can connect a CDROM to the slave of ide0:
648 @example
649 qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
650 @end example
653 @example
655 @end example
658 @example
660 @end example
663 @example
666 @end example
669 incremented:
670 @example
672 @end example
673 is interpreted like:
674 @example
675 qemu-system-i386 -hda a -hdb b
676 @end example
677 ETEXI
681 QEMU_ARCH_ALL)
682 STEXI
683 @item -mtdblock @var{file}
684 @findex -mtdblock
685 Use @var{file} as on-board Flash memory image.
686 ETEXI
690 STEXI
691 @item -sd @var{file}
692 @findex -sd
693 Use @var{file} as SecureDigital card image.
694 ETEXI
698 STEXI
699 @item -pflash @var{file}
700 @findex -pflash
701 Use @var{file} as a parallel flash image.
702 ETEXI
706 QEMU_ARCH_ALL)
707 STEXI
708 @item -snapshot
709 @findex -snapshot
710 Write to temporary files instead of disk image files. In this case,
711 the raw disk image you use is not written back. You can however force
712 the write back by pressing @key{C-a s} (@pxref{disk_images}).
713 ETEXI
719 QEMU_ARCH_ALL)
720 STEXI
721 @item -hdachs @var{c},@var{h},@var{s},[,@var{t}]
722 @findex -hdachs
723 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
724 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
725 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
726 all those parameters. This option is useful for old MS-DOS disk
727 images.
728 ETEXI
731 "-fsdev fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
733 QEMU_ARCH_ALL)
735 STEXI
737 @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}]
738 @findex -fsdev
739 Define a new file system device. Valid options are:
740 @table @option
741 @item @var{fsdriver}
742 This option specifies the fs driver backend to use.
744 @item id=@var{id}
745 Specifies identifier for this device
746 @item path=@var{path}
747 Specifies the export path for the file system device. Files under
748 this path will be available to the 9p client on the guest.
749 @item security_model=@var{security_model}
750 Specifies the security model to be used for this export path.
753 credentials as they are created on the guest. This requires QEMU
755 attributes like uid, gid, mode bits and link target are stored as
757 hidden .virtfs_metadata directory. Directories exported by this security model cannot
759 passthrough except the sever won't report failures if it fails to
760 set file attributes like ownership. Security model is mandatory
761 only for local fsdriver. Other fsdrivers (like handle, proxy) don't take
762 security model as a parameter.
763 @item writeout=@var{writeout}
765 This means that host page cache will be used to read and write data but
766 write notification will be sent to the guest only when the data has been
767 reported as written by the storage subsystem.
768 @item readonly
769 Enables exporting 9p share as a readonly mount for guests. By default
770 read-write access is given.
771 @item socket=@var{socket}
772 Enables proxy filesystem driver to use passed socket file for communicating
773 with virtfs-proxy-helper
774 @item sock_fd=@var{sock_fd}
775 Enables proxy filesystem driver to use passed socket descriptor for
776 communicating with virtfs-proxy-helper. Usually a helper like libvirt
777 will create socketpair and pass one of the fds as sock_fd
778 @end table
781 @item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
782 Options for virtio-9p-pci driver are:
783 @table @option
784 @item fsdev=@var{id}
785 Specifies the id value specified along with -fsdev option
786 @item mount_tag=@var{mount_tag}
787 Specifies the tag name to be used by the guest to mount this export point
788 @end table
790 ETEXI
793 "-virtfs local,path=path,mount_tag=tag,security_model=[mapped-xattr|mapped-file|passthrough|none]\n"
795 QEMU_ARCH_ALL)
797 STEXI
799 @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}]
800 @findex -virtfs
802 The general form of a Virtual File system pass-through options are:
803 @table @option
804 @item @var{fsdriver}
805 This option specifies the fs driver backend to use.
807 @item id=@var{id}
808 Specifies identifier for this device
809 @item path=@var{path}
810 Specifies the export path for the file system device. Files under
811 this path will be available to the 9p client on the guest.
812 @item security_model=@var{security_model}
813 Specifies the security model to be used for this export path.
816 credentials as they are created on the guest. This requires QEMU
818 attributes like uid, gid, mode bits and link target are stored as
820 hidden .virtfs_metadata directory. Directories exported by this security model cannot
822 passthrough except the sever won't report failures if it fails to
823 set file attributes like ownership. Security model is mandatory only
824 for local fsdriver. Other fsdrivers (like handle, proxy) don't take security
825 model as a parameter.
826 @item writeout=@var{writeout}
828 This means that host page cache will be used to read and write data but
829 write notification will be sent to the guest only when the data has been
830 reported as written by the storage subsystem.
831 @item readonly
832 Enables exporting 9p share as a readonly mount for guests. By default
833 read-write access is given.
834 @item socket=@var{socket}
835 Enables proxy filesystem driver to use passed socket file for
836 communicating with virtfs-proxy-helper. Usually a helper like libvirt
837 will create socketpair and pass one of the fds as sock_fd
838 @item sock_fd
839 Enables proxy filesystem driver to use passed 'sock_fd' as the socket
840 descriptor for interfacing with virtfs-proxy-helper
841 @end table
842 ETEXI
846 QEMU_ARCH_ALL)
847 STEXI
848 @item -virtfs_synth
849 @findex -virtfs_synth
850 Create synthetic file system image
851 ETEXI
853 STEXI
854 @end table
855 ETEXI
856 DEFHEADING()
858 DEFHEADING(USB options)
859 STEXI
860 @table @option
861 ETEXI
865 QEMU_ARCH_ALL)
866 STEXI
867 @item -usb
868 @findex -usb
869 Enable the USB driver (will be the default soon)
870 ETEXI
874 QEMU_ARCH_ALL)
875 STEXI
877 @item -usbdevice @var{devname}
878 @findex -usbdevice
879 Add the USB device @var{devname}. @xref{usb_devices}.
881 @table @option
883 @item mouse
884 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
886 @item tablet
887 Pointer device that uses absolute coordinates (like a touchscreen). This
888 means QEMU is able to report the mouse position without having to grab the
889 mouse. Also overrides the PS/2 mouse emulation when activated.
891 @item disk:[format=@var{format}]:@var{file}
892 Mass storage device based on file. The optional @var{format} argument
893 will be used rather than detecting the format. Can be used to specify
894 @code{format=raw} to avoid interpreting an untrusted format header.
896 @item host:@var{bus}.@var{addr}
897 Pass through the host device identified by @var{bus}.@var{addr} (Linux only).
899 @item host:@var{vendor_id}:@var{product_id}
900 Pass through the host device identified by @var{vendor_id}:@var{product_id}
901 (Linux only).
903 @item serial:[vendorid=@var{vendor_id}][,productid=@var{product_id}]:@var{dev}
904 Serial converter to host character device @var{dev}, see @code{-serial} for the
905 available devices.
907 @item braille
908 Braille device. This will use BrlAPI to display the braille output on a real
909 or fake device.
911 @item net:@var{options}
912 Network adapter that supports CDC ethernet and RNDIS protocols.
914 @end table
915 ETEXI
917 STEXI
918 @end table
919 ETEXI
920 DEFHEADING()
922 DEFHEADING(Display options)
923 STEXI
924 @table @option
925 ETEXI
936 #if defined(CONFIG_GTK)
938 #elif defined(CONFIG_SDL)
940 #elif defined(CONFIG_COCOA)
942 #elif defined(CONFIG_VNC)
944 #else
946 #endif
947 , QEMU_ARCH_ALL)
948 STEXI
949 @item -display @var{type}
950 @findex -display
951 Select type of display to use. This option is a replacement for the
952 old style -sdl/-curses/... options. Valid values for @var{type} are
953 @table @option
954 @item sdl
955 Display video output via SDL (usually in a separate graphics
956 window; see the SDL documentation for other possibilities).
957 @item curses
958 Display video output via curses. For graphics device models which
959 support a text mode, QEMU can display this output using a
960 curses/ncurses interface. Nothing is displayed when the graphics
961 device is in graphical mode or if the graphics device does not support
962 a text mode. Generally only the VGA device models support text mode.
963 @item none
964 Do not display video output. The guest will still see an emulated
965 graphics card, but its output will not be displayed to the QEMU
966 user. This option differs from the -nographic option in that it
967 only affects what is done with video output; -nographic also changes
968 the destination of the serial and parallel port data.
969 @item gtk
970 Display video output in a GTK window. This interface provides drop-down
971 menus and other UI elements to configure and control the VM during
972 runtime.
973 @item vnc
974 Start a VNC server on display <arg>
975 @end table
976 ETEXI
980 QEMU_ARCH_ALL)
981 STEXI
982 @item -nographic
983 @findex -nographic
984 Normally, if QEMU is compiled with graphical window support, it displays
985 output such as guest graphics, guest console, and the QEMU monitor in a
986 window. With this option, you can totally disable graphical output so
987 that QEMU is a simple command line application. The emulated serial port
988 is redirected on the console and muxed with the monitor (unless
989 redirected elsewhere explicitly). Therefore, you can still use QEMU to
990 debug a Linux kernel with a serial console. Use @key{C-a h} for help on
991 switching between the console and monitor.
992 ETEXI
996 QEMU_ARCH_ALL)
997 STEXI
998 @item -curses
999 @findex -curses
1000 Normally, if QEMU is compiled with graphical window support, it displays
1001 output such as guest graphics, guest console, and the QEMU monitor in a
1002 window. With this option, QEMU can display the VGA output when in text
1003 mode using a curses/ncurses interface. Nothing is displayed in graphical
1004 mode.
1005 ETEXI
1009 QEMU_ARCH_ALL)
1010 STEXI
1011 @item -no-frame
1012 @findex -no-frame
1013 Do not use decorations for SDL windows and start them using the whole
1014 available screen space. This makes the using QEMU in a dedicated desktop
1015 workspace more convenient.
1016 ETEXI
1020 QEMU_ARCH_ALL)
1021 STEXI
1022 @item -alt-grab
1023 @findex -alt-grab
1024 Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also
1025 affects the special keys (for fullscreen, monitor-mode switching, etc).
1026 ETEXI
1030 QEMU_ARCH_ALL)
1031 STEXI
1032 @item -ctrl-grab
1033 @findex -ctrl-grab
1034 Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also
1035 affects the special keys (for fullscreen, monitor-mode switching, etc).
1036 ETEXI
1040 STEXI
1041 @item -no-quit
1042 @findex -no-quit
1043 Disable SDL window close capability.
1044 ETEXI
1048 STEXI
1049 @item -sdl
1050 @findex -sdl
1051 Enable SDL.
1052 ETEXI
1072 QEMU_ARCH_ALL)
1073 STEXI
1074 @item -spice @var{option}[,@var{option}[,...]]
1075 @findex -spice
1076 Enable the spice remote desktop protocol. Valid options are
1078 @table @option
1080 @item port=<nr>
1081 Set the TCP port spice is listening on for plaintext channels.
1083 @item addr=<addr>
1084 Set the IP address spice is listening on. Default is any address.
1086 @item ipv4
1087 @itemx ipv6
1088 @itemx unix
1089 Force using the specified IP version.
1091 @item password=<secret>
1092 Set the password you need to authenticate.
1094 @item sasl
1095 Require that the client use SASL to authenticate with the spice.
1096 The exact choice of authentication method used is controlled from the
1097 system / user's SASL configuration file for the 'qemu' service. This
1098 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1099 unprivileged user, an environment variable SASL_CONF_PATH can be used
1100 to make it search alternate locations for the service config.
1101 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1102 it is recommended that SASL always be combined with the 'tls' and
1103 'x509' settings to enable use of SSL and server certificates. This
1104 ensures a data encryption preventing compromise of authentication
1105 credentials.
1107 @item disable-ticketing
1108 Allow client connects without authentication.
1110 @item disable-copy-paste
1111 Disable copy paste between the client and the guest.
1113 @item disable-agent-file-xfer
1114 Disable spice-vdagent based file-xfer between the client and the guest.
1116 @item tls-port=<nr>
1117 Set the TCP port spice is listening on for encrypted channels.
1119 @item x509-dir=<dir>
1120 Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir
1122 @item x509-key-file=<file>
1123 @itemx x509-key-password=<file>
1124 @itemx x509-cert-file=<file>
1125 @itemx x509-cacert-file=<file>
1126 @itemx x509-dh-key-file=<file>
1127 The x509 file names can also be configured individually.
1129 @item tls-ciphers=<list>
1130 Specify which ciphers to use.
1132 @item tls-channel=[main|display|cursor|inputs|record|playback]
1133 @itemx plaintext-channel=[main|display|cursor|inputs|record|playback]
1134 Force specific channel to be used with or without TLS encryption. The
1135 options can be specified multiple times to configure multiple
1137 mode. For channels which are not explicitly forced into one mode the
1138 spice client is allowed to pick tls/plaintext as he pleases.
1140 @item image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
1141 Configure image compression (lossless).
1142 Default is auto_glz.
1144 @item jpeg-wan-compression=[auto|never|always]
1145 @itemx zlib-glz-wan-compression=[auto|never|always]
1146 Configure wan image compression (lossy for slow links).
1147 Default is auto.
1149 @item streaming-video=[off|all|filter]
1150 Configure video stream detection. Default is off.
1152 @item agent-mouse=[on|off]
1153 Enable/disable passing mouse events via vdagent. Default is on.
1155 @item playback-compression=[on|off]
1156 Enable/disable audio stream compression (using celt 0.5.1). Default is on.
1158 @item seamless-migration=[on|off]
1159 Enable/disable spice seamless migration. Default is off.
1161 @item gl=[on|off]
1162 Enable/disable OpenGL context. Default is off.
1164 @end table
1165 ETEXI
1169 QEMU_ARCH_ALL)
1170 STEXI
1171 @item -portrait
1172 @findex -portrait
1173 Rotate graphical output 90 deg left (only PXA LCD).
1174 ETEXI
1178 QEMU_ARCH_ALL)
1179 STEXI
1180 @item -rotate @var{deg}
1181 @findex -rotate
1182 Rotate graphical output some deg left (only PXA LCD).
1183 ETEXI
1188 STEXI
1189 @item -vga @var{type}
1190 @findex -vga
1191 Select type of VGA card to emulate. Valid values for @var{type} are
1192 @table @option
1193 @item cirrus
1194 Cirrus Logic GD5446 Video card. All Windows versions starting from
1195 Windows 95 should recognize and use this graphic card. For optimal
1196 performances, use 16 bit color depth in the guest and the host OS.
1197 (This one is the default)
1198 @item std
1199 Standard VGA card with Bochs VBE extensions. If your guest OS
1200 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if you want
1201 to use high resolution modes (>= 1280x1024x16) then you should use
1202 this option.
1203 @item vmware
1204 VMWare SVGA-II compatible adapter. Use it if you have sufficiently
1205 recent XFree86/XOrg server or Windows guest with a driver for this
1206 card.
1207 @item qxl
1208 QXL paravirtual graphic card. It is VGA compatible (including VESA
1209 2.0 VBE support). Works best with qxl guest drivers installed though.
1210 Recommended choice when using the spice protocol.
1211 @item tcx
1212 (sun4m only) Sun TCX framebuffer. This is the default framebuffer for
1213 sun4m machines and offers both 8-bit and 24-bit colour depths at a
1214 fixed resolution of 1024x768.
1215 @item cg3
1216 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit framebuffer
1217 for sun4m machines available in both 1024x768 (OpenBIOS) and 1152x900 (OBP)
1218 resolutions aimed at people wishing to run older Solaris versions.
1219 @item virtio
1220 Virtio VGA card.
1221 @item none
1222 Disable VGA card.
1223 @end table
1224 ETEXI
1228 STEXI
1229 @item -full-screen
1230 @findex -full-screen
1231 Start in full screen.
1232 ETEXI
1236 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
1237 STEXI
1238 @item -g @var{width}x@var{height}[x@var{depth}]
1239 @findex -g
1240 Set the initial graphical resolution and depth (PPC, SPARC only).
1241 ETEXI
1245 STEXI
1246 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
1247 @findex -vnc
1248 Normally, if QEMU is compiled with graphical window support, it displays
1249 output such as guest graphics, guest console, and the QEMU monitor in a
1250 window. With this option, you can have QEMU listen on VNC display
1251 @var{display} and redirect the VGA display over the VNC session. It is
1252 very useful to enable the usb tablet device when using this option
1253 (option @option{-usbdevice tablet}). When using the VNC display, you
1254 must use the @option{-k} parameter to set the keyboard layout if you are
1255 not using en-us. Valid syntax for the @var{display} is
1257 @table @option
1259 @item to=@var{L}
1261 With this option, QEMU will try next available VNC @var{display}s, until the
1263 available, e.g. port 5900+@var{display} is already used by another
1264 application. By default, to=0.
1266 @item @var{host}:@var{d}
1268 TCP connections will only be allowed from @var{host} on display @var{d}.
1269 By convention the TCP port is 5900+@var{d}. Optionally, @var{host} can
1270 be omitted in which case the server will accept connections from any host.
1272 @item unix:@var{path}
1274 Connections will be allowed over UNIX domain sockets where @var{path} is the
1275 location of a unix socket to listen for connections on.
1277 @item none
1279 VNC is initialized but not started. The monitor @code{change} command
1280 can be used to later start the VNC server.
1282 @end table
1284 Following the @var{display} value there may be one or more @var{option} flags
1285 separated by commas. Valid options are
1287 @table @option
1289 @item reverse
1291 Connect to a listening VNC client via a ``reverse'' connection. The
1292 client is specified by the @var{display}. For reverse network
1293 connections (@var{host}:@var{d},@code{reverse}), the @var{d} argument
1294 is a TCP port number, not a display number.
1296 @item websocket
1298 Opens an additional TCP listening port dedicated to VNC Websocket connections.
1299 By definition the Websocket port is 5700+@var{display}. If @var{host} is
1300 specified connections will only be allowed from this host.
1301 As an alternative the Websocket port could be specified by using
1302 @code{websocket}=@var{port}.
1303 If no TLS credentials are provided, the websocket connection runs in
1304 unencrypted mode. If TLS credentials are provided, the websocket connection
1305 requires encrypted client connections.
1307 @item password
1309 Require that password based authentication is used for client connections.
1311 The password must be set separately using the @code{set_password} command in
1312 the @ref{pcsys_monitor}. The syntax to change your password is:
1313 @code{set_password <protocol> <password>} where <protocol> could be either
1316 If you would like to change <protocol> password expiration, you should use
1317 @code{expire_password <protocol> <expiration-time>} where expiration time could
1318 be one of the following options: now, never, +seconds or UNIX time of
1319 expiration, e.g. +60 to make password expire in 60 seconds, or 1335196800
1321 date and time).
1324 allow <protocol> password to expire immediately or never expire.
1326 @item tls-creds=@var{ID}
1328 Provides the ID of a set of TLS credentials to use to secure the
1329 VNC server. They will apply to both the normal VNC server socket
1330 and the websocket socket (if enabled). Setting TLS credentials
1331 will cause the VNC server socket to enable the VeNCrypt auth
1332 mechanism. The credentials should have been previously created
1333 using the @option{-object tls-creds} argument.
1335 The @option{tls-creds} parameter obsoletes the @option{tls},
1336 @option{x509}, and @option{x509verify} options, and as such
1337 it is not permitted to set both new and old type options at
1338 the same time.
1340 @item tls
1342 Require that client use TLS when communicating with the VNC server. This
1343 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
1344 attack. It is recommended that this option be combined with either the
1345 @option{x509} or @option{x509verify} options.
1347 This option is now deprecated in favor of using the @option{tls-creds}
1348 argument.
1350 @item x509=@var{/path/to/certificate/dir}
1352 Valid if @option{tls} is specified. Require that x509 credentials are used
1353 for negotiating the TLS session. The server will send its x509 certificate
1354 to the client. It is recommended that a password be set on the VNC server
1355 to provide authentication of the client when this is used. The path following
1356 this option specifies where the x509 certificates are to be loaded from.
1357 See the @ref{vnc_security} section for details on generating certificates.
1359 This option is now deprecated in favour of using the @option{tls-creds}
1360 argument.
1362 @item x509verify=@var{/path/to/certificate/dir}
1364 Valid if @option{tls} is specified. Require that x509 credentials are used
1365 for negotiating the TLS session. The server will send its x509 certificate
1366 to the client, and request that the client send its own x509 certificate.
1367 The server will validate the client's certificate against the CA certificate,
1368 and reject clients when validation fails. If the certificate authority is
1369 trusted, this is a sufficient authentication mechanism. You may still wish
1370 to set a password on the VNC server as a second authentication layer. The
1371 path following this option specifies where the x509 certificates are to
1372 be loaded from. See the @ref{vnc_security} section for details on generating
1373 certificates.
1375 This option is now deprecated in favour of using the @option{tls-creds}
1376 argument.
1378 @item sasl
1380 Require that the client use SASL to authenticate with the VNC server.
1381 The exact choice of authentication method used is controlled from the
1382 system / user's SASL configuration file for the 'qemu' service. This
1383 is typically found in /etc/sasl2/qemu.conf. If running QEMU as an
1384 unprivileged user, an environment variable SASL_CONF_PATH can be used
1385 to make it search alternate locations for the service config.
1386 While some SASL auth methods can also provide data encryption (eg GSSAPI),
1387 it is recommended that SASL always be combined with the 'tls' and
1388 'x509' settings to enable use of SSL and server certificates. This
1389 ensures a data encryption preventing compromise of authentication
1390 credentials. See the @ref{vnc_security} section for details on using
1391 SASL authentication.
1393 @item acl
1395 Turn on access control lists for checking of the x509 client certificate
1396 and SASL party. For x509 certs, the ACL check is made against the
1397 certificate's distinguished name. This is something that looks like
1398 @code{C=GB,O=ACME,L=Boston,CN=bob}. For SASL party, the ACL check is
1399 made against the username, which depending on the SASL plugin, may
1400 include a realm component, eg @code{bob} or @code{bob@@EXAMPLE.COM}.
1401 When the @option{acl} flag is set, the initial access list will be
1402 empty, with a @code{deny} policy. Thus no one will be allowed to
1403 use the VNC server until the ACLs have been loaded. This can be
1404 achieved using the @code{acl} monitor command.
1406 @item lossy
1408 Enable lossy compression methods (gradient, JPEG, ...). If this
1409 option is set, VNC client may receive lossy framebuffer updates
1410 depending on its encoding settings. Enabling this option can save
1411 a lot of bandwidth at the expense of quality.
1413 @item non-adaptive
1415 Disable adaptive encodings. Adaptive encodings are enabled by default.
1416 An adaptive encoding will try to detect frequently updated screen regions,
1417 and send updates in these regions using a lossy encoding (like JPEG).
1418 This can be really helpful to save bandwidth when playing videos. Disabling
1419 adaptive encodings restores the original static behavior of encodings
1420 like Tight.
1422 @item share=[allow-exclusive|force-shared|ignore]
1424 Set display sharing policy. 'allow-exclusive' allows clients to ask
1425 for exclusive access. As suggested by the rfb spec this is
1426 implemented by dropping other connections. Connecting multiple
1427 clients in parallel requires all clients asking for a shared session
1428 (vncviewer: -shared switch). This is the default. 'force-shared'
1429 disables exclusive client access. Useful for shared desktop sessions,
1430 where you don't want someone forgetting specify -shared disconnect
1431 everybody else. 'ignore' completely ignores the shared flag and
1432 allows everybody connect unconditionally. Doesn't conform to the rfb
1433 spec but is traditional QEMU behavior.
1435 @item key-delay-ms
1437 Set keyboard delay, for key down and key up events, in milliseconds.
1438 Default is 1. Keyboards are low-bandwidth devices, so this slowdown
1439 can help the device and guest to keep up and not lose events in case
1440 events are arriving in bulk. Possible causes for the latter are flaky
1441 network connections, or scripts for automated testing.
1443 @end table
1444 ETEXI
1446 STEXI
1447 @end table
1448 ETEXI
1449 ARCHHEADING(, QEMU_ARCH_I386)
1451 ARCHHEADING(i386 target only, QEMU_ARCH_I386)
1452 STEXI
1453 @table @option
1454 ETEXI
1458 QEMU_ARCH_I386)
1459 STEXI
1460 @item -win2k-hack
1461 @findex -win2k-hack
1462 Use it when installing Windows 2000 to avoid a disk full bug. After
1463 Windows 2000 is installed, you no longer need this option (this option
1464 slows down the IDE transfers).
1465 ETEXI
1467 HXCOMM Deprecated by -rtc
1472 QEMU_ARCH_I386)
1473 STEXI
1474 @item -no-fd-bootchk
1475 @findex -no-fd-bootchk
1476 Disable boot signature checking for floppy disks in BIOS. May
1477 be needed to boot from old floppy disks.
1478 ETEXI
1482 STEXI
1483 @item -no-acpi
1484 @findex -no-acpi
1485 Disable ACPI (Advanced Configuration and Power Interface) support. Use
1486 it if your guest OS complains about ACPI problems (PC target machine
1487 only).
1488 ETEXI
1492 STEXI
1493 @item -no-hpet
1494 @findex -no-hpet
1495 Disable HPET support.
1496 ETEXI
1499 "-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"
1501 STEXI
1502 @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}]...]
1503 @findex -acpitable
1504 Add ACPI table with specified header fields and context from specified files.
1505 For file=, take whole ACPI table from the specified files, including all
1506 ACPI headers (possible overridden by other options).
1507 For data=, only data
1508 portion of the table is used, all header information is specified in the
1509 command line.
1510 If a SLIC table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
1511 fields will override the same in the RSDT and the FADT (a.k.a. FACP), in order
1512 to ensure the field matches required by the Microsoft SLIC spec and the ACPI
1513 spec.
1514 ETEXI
1537 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
1538 STEXI
1539 @item -smbios file=@var{binary}
1540 @findex -smbios
1541 Load SMBIOS entry from binary file.
1543 @item -smbios type=0[,vendor=@var{str}][,version=@var{str}][,date=@var{str}][,release=@var{%d.%d}][,uefi=on|off]
1544 Specify SMBIOS type 0 fields
1546 @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}]
1547 Specify SMBIOS type 1 fields
1549 @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}]
1550 Specify SMBIOS type 2 fields
1552 @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
1553 Specify SMBIOS type 3 fields
1555 @item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
1556 Specify SMBIOS type 4 fields
1558 @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}]
1559 Specify SMBIOS type 17 fields
1560 ETEXI
1562 STEXI
1563 @end table
1564 ETEXI
1565 DEFHEADING()
1567 DEFHEADING(Network options)
1568 STEXI
1569 @table @option
1570 ETEXI
1572 HXCOMM Legacy slirp options (now moved to -net user):
1573 #ifdef CONFIG_SLIRP
1577 #ifndef _WIN32
1579 #endif
1580 #endif
1583 #ifdef CONFIG_SLIRP
1589 #ifndef _WIN32
1591 #endif
1594 #endif
1595 #ifdef _WIN32
1598 #else
1629 #endif
1630 #ifdef __linux__
1656 #endif
1666 #ifdef CONFIG_VDE
1672 #endif
1673 #ifdef CONFIG_NETMAP
1678 #endif
1692 #ifdef CONFIG_SLIRP
1694 #endif
1697 #ifdef CONFIG_VDE
1699 #endif
1700 #ifdef CONFIG_NETMAP
1702 #endif
1706 STEXI
1707 @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
1708 @findex -net
1709 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
1710 = 0 is the default). The NIC is an e1000 by default on the PC
1711 target. Optionally, the MAC address can be changed to @var{mac}, the
1712 device address set to @var{addr} (PCI cards only),
1713 and a @var{name} can be assigned for use in monitor commands.
1714 Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
1715 that the card should have; this option currently only affects virtio cards; set
1716 @var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
1717 NIC is created. QEMU can emulate several different models of network card.
1718 Valid values for @var{type} are
1719 @code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
1720 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
1721 @code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
1722 Not all devices are supported on all targets. Use @code{-net nic,model=help}
1723 for a list of available devices for your target.
1725 @item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
1726 @findex -netdev
1727 @item -net user[,@var{option}][,@var{option}][,...]
1728 Use the user mode network stack which requires no administrator
1729 privilege to run. Valid options are:
1731 @table @option
1732 @item vlan=@var{n}
1733 Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
1735 @item id=@var{id}
1736 @itemx name=@var{name}
1737 Assign symbolic name for use in monitor commands.
1739 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
1740 be enabled. If neither is specified both protocols are enabled.
1742 @item net=@var{addr}[/@var{mask}]
1743 Set IP network address the guest will see. Optionally specify the netmask,
1744 either in the form a.b.c.d or as number of valid top-most bits. Default is
1745 10.0.2.0/24.
1747 @item host=@var{addr}
1748 Specify the guest-visible address of the host. Default is the 2nd IP in the
1749 guest network, i.e. x.x.x.2.
1751 @item ipv6-net=@var{addr}[/@var{int}]
1752 Set IPv6 network address the guest will see (default is fec0::/64). The
1753 network prefix is given in the usual hexadecimal IPv6 address
1754 notation. The prefix size is optional, and is given as the number of
1755 valid top-most bits (default is 64).
1757 @item ipv6-host=@var{addr}
1758 Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 in
1759 the guest network, i.e. xxxx::2.
1761 @item restrict=on|off
1762 If this option is enabled, the guest will be isolated, i.e. it will not be
1763 able to contact the host and no guest IP packets will be routed over the host
1764 to the outside. This option does not affect any explicitly set forwarding rules.
1766 @item hostname=@var{name}
1767 Specifies the client hostname reported by the built-in DHCP server.
1769 @item dhcpstart=@var{addr}
1770 Specify the first of the 16 IPs the built-in DHCP server can assign. Default
1771 is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
1773 @item dns=@var{addr}
1774 Specify the guest-visible address of the virtual nameserver. The address must
1775 be different from the host address. Default is the 3rd IP in the guest network,
1776 i.e. x.x.x.3.
1778 @item ipv6-dns=@var{addr}
1779 Specify the guest-visible address of the IPv6 virtual nameserver. The address
1780 must be different from the host address. Default is the 3rd IP in the guest
1781 network, i.e. xxxx::3.
1783 @item dnssearch=@var{domain}
1784 Provides an entry for the domain-search list sent by the built-in
1785 DHCP server. More than one domain suffix can be transmitted by specifying
1786 this option multiple times. If supported, this will cause the guest to
1787 automatically try to append the given domain suffix(es) in case a domain name
1788 can not be resolved.
1790 Example:
1791 @example
1792 qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
1793 @end example
1795 @item tftp=@var{dir}
1796 When using the user mode network stack, activate a built-in TFTP
1797 server. The files in @var{dir} will be exposed as the root of a TFTP server.
1798 The TFTP client on the guest must be configured in binary mode (use the command
1799 @code{bin} of the Unix TFTP client).
1801 @item bootfile=@var{file}
1802 When using the user mode network stack, broadcast @var{file} as the BOOTP
1803 filename. In conjunction with @option{tftp}, this can be used to network boot
1804 a guest from a local directory.
1806 Example (using pxelinux):
1807 @example
1808 qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
1809 @end example
1811 @item smb=@var{dir}[,smbserver=@var{addr}]
1812 When using the user mode network stack, activate a built-in SMB
1813 server so that Windows OSes can access to the host files in @file{@var{dir}}
1814 transparently. The IP address of the SMB server can be set to @var{addr}. By
1815 default the 4th IP in the guest network is used, i.e. x.x.x.4.
1817 In the guest Windows OS, the line:
1818 @example
1819 10.0.2.4 smbserver
1820 @end example
1821 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
1822 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
1826 Note that a SAMBA server must be installed on the host OS.
1827 QEMU was tested successfully with smbd versions from Red Hat 9,
1828 Fedora Core 3 and OpenSUSE 11.x.
1830 @item hostfwd=[tcp|udp]:[@var{hostaddr}]:@var{hostport}-[@var{guestaddr}]:@var{guestport}
1831 Redirect incoming TCP or UDP connections to the host port @var{hostport} to
1832 the guest IP address @var{guestaddr} on guest port @var{guestport}. If
1833 @var{guestaddr} is not specified, its value is x.x.x.15 (default first address
1834 given by the built-in DHCP server). By specifying @var{hostaddr}, the rule can
1835 be bound to a specific host interface. If no connection type is set, TCP is
1836 used. This option can be given multiple times.
1838 For example, to redirect host X11 connection from screen 1 to guest
1839 screen 0, use the following:
1841 @example
1842 # on the host
1843 qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
1844 # this host xterm should open in the guest X11 server
1845 xterm -display :1
1846 @end example
1848 To redirect telnet connections from host port 5555 to telnet port on
1849 the guest, use the following:
1851 @example
1852 # on the host
1853 qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
1854 telnet localhost 5555
1855 @end example
1857 Then when you use on the host @code{telnet localhost 5555}, you
1858 connect to the guest telnet server.
1860 @item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
1861 @itemx guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
1862 Forward guest TCP connections to the IP address @var{server} on port @var{port}
1863 to the character device @var{dev} or to a program executed by @var{cmd:command}
1864 which gets spawned for each connection. This option can be given multiple times.
1866 You can either use a chardev directly and have that one used throughout QEMU's
1867 lifetime, like in the following example:
1869 @example
1870 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
1871 # the guest accesses it
1872 qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
1873 @end example
1875 Or you can execute a command on every TCP connection established by the guest,
1876 so that QEMU behaves similar to an inetd process for that virtual server:
1878 @example
1880 # and connect the TCP stream to its stdin/stdout
1881 qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
1882 @end example
1884 @end table
1886 Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still
1887 processed and applied to -net user. Mixing them with the new configuration
1888 syntax gives undefined results. Their use for new applications is discouraged
1889 as they will be removed from future versions.
1891 @item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
1892 @itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
1893 Connect the host TAP network interface @var{name} to VLAN @var{n}.
1895 Use the network script @var{file} to configure it and the network script
1896 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
1897 automatically provides one. The default network configure script is
1898 @file{/etc/qemu-ifup} and the default network deconfigure script is
1899 @file{/etc/qemu-ifdown}. Use @option{script=no} or @option{downscript=no}
1900 to disable script execution.
1902 If running QEMU as an unprivileged user, use the network helper
1903 @var{helper} to configure the TAP interface and attach it to the bridge.
1904 The default network helper executable is @file{/path/to/qemu-bridge-helper}
1905 and the default bridge device is @file{br0}.
1907 @option{fd}=@var{h} can be used to specify the handle of an already
1908 opened host TAP interface.
1910 Examples:
1912 @example
1913 #launch a QEMU instance with the default network script
1914 qemu-system-i386 linux.img -net nic -net tap
1915 @end example
1917 @example
1918 #launch a QEMU instance with two NICs, each one connected
1919 #to a TAP device
1920 qemu-system-i386 linux.img \
1921 -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
1922 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
1923 @end example
1925 @example
1926 #launch a QEMU instance with the default network helper to
1927 #connect a TAP device to bridge br0
1928 qemu-system-i386 linux.img \
1930 @end example
1932 @item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
1933 @itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
1934 Connect a host TAP network interface to a host bridge device.
1936 Use the network helper @var{helper} to configure the TAP interface and
1937 attach it to the bridge. The default network helper executable is
1938 @file{/path/to/qemu-bridge-helper} and the default bridge
1939 device is @file{br0}.
1941 Examples:
1943 @example
1944 #launch a QEMU instance with the default network helper to
1945 #connect a TAP device to bridge br0
1946 qemu-system-i386 linux.img -net bridge -net nic,model=virtio
1947 @end example
1949 @example
1950 #launch a QEMU instance with the default network helper to
1951 #connect a TAP device to bridge qemubr0
1952 qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
1953 @end example
1955 @item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1956 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
1958 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
1959 machine using a TCP socket connection. If @option{listen} is
1960 specified, QEMU waits for incoming connections on @var{port}
1961 (@var{host} is optional). @option{connect} is used to connect to
1962 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
1963 specifies an already opened TCP socket.
1965 Example:
1966 @example
1967 # launch a first QEMU instance
1968 qemu-system-i386 linux.img \
1969 -net nic,macaddr=52:54:00:12:34:56 \
1970 -net socket,listen=:1234
1971 # connect the VLAN 0 of this instance to the VLAN 0
1972 # of the first instance
1973 qemu-system-i386 linux.img \
1974 -net nic,macaddr=52:54:00:12:34:57 \
1975 -net socket,connect=127.0.0.1:1234
1976 @end example
1978 @item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1979 @itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
1981 Create a VLAN @var{n} shared with another QEMU virtual
1982 machines using a UDP multicast socket, effectively making a bus for
1983 every QEMU with same multicast address @var{maddr} and @var{port}.
1984 NOTES:
1985 @enumerate
1986 @item
1987 Several QEMU can be running on different hosts and share same bus (assuming
1988 correct multicast setup for these hosts).
1989 @item
1990 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
1991 @url{http://user-mode-linux.sf.net}.
1992 @item
1993 Use @option{fd=h} to specify an already opened UDP multicast socket.
1994 @end enumerate
1996 Example:
1997 @example
1998 # launch one QEMU instance
1999 qemu-system-i386 linux.img \
2000 -net nic,macaddr=52:54:00:12:34:56 \
2001 -net socket,mcast=230.0.0.1:1234
2003 qemu-system-i386 linux.img \
2004 -net nic,macaddr=52:54:00:12:34:57 \
2005 -net socket,mcast=230.0.0.1:1234
2007 qemu-system-i386 linux.img \
2008 -net nic,macaddr=52:54:00:12:34:58 \
2009 -net socket,mcast=230.0.0.1:1234
2010 @end example
2012 Example (User Mode Linux compat.):
2013 @example
2014 # launch QEMU instance (note mcast address selected
2015 # is UML's default)
2016 qemu-system-i386 linux.img \
2017 -net nic,macaddr=52:54:00:12:34:56 \
2018 -net socket,mcast=239.192.168.1:1102
2019 # launch UML
2020 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
2021 @end example
2023 Example (send packets from host's 1.2.3.4):
2024 @example
2025 qemu-system-i386 linux.img \
2026 -net nic,macaddr=52:54:00:12:34:56 \
2027 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
2028 @end example
2030 @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}]
2031 @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}]
2032 Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
2033 protocol to transport Ethernet (and other Layer 2) data frames between
2034 two systems. It is present in routers, firewalls and the Linux kernel
2035 (from version 3.3 onwards).
2037 This transport allows a VM to communicate to another VM, router or firewall directly.
2039 @item src=@var{srcaddr}
2040 source address (mandatory)
2041 @item dst=@var{dstaddr}
2042 destination address (mandatory)
2043 @item udp
2044 select udp encapsulation (default is ip).
2045 @item srcport=@var{srcport}
2046 source udp port.
2047 @item dstport=@var{dstport}
2048 destination udp port.
2049 @item ipv6
2050 force v6, otherwise defaults to v4.
2051 @item rxcookie=@var{rxcookie}
2052 @itemx txcookie=@var{txcookie}
2053 Cookies are a weak form of security in the l2tpv3 specification.
2054 Their function is mostly to prevent misconfiguration. By default they are 32
2055 bit.
2056 @item cookie64
2057 Set cookie size to 64 bit instead of the default 32
2058 @item counter=off
2059 Force a 'cut-down' L2TPv3 with no counter as in
2060 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
2061 @item pincounter=on
2062 Work around broken counter handling in peer. This may also help on
2063 networks which have packet reorder.
2064 @item offset=@var{offset}
2065 Add an extra offset between header and data
2067 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to the bridge br-lan
2068 on the remote Linux host 1.2.3.4:
2069 @example
2070 # Setup tunnel on linux host using raw ip as encapsulation
2071 # on 1.2.3.4
2072 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
2073 encap udp udp_sport 16384 udp_dport 16384
2074 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
2075 0xFFFFFFFF peer_session_id 0xFFFFFFFF
2076 ifconfig vmtunnel0 mtu 1500
2077 ifconfig vmtunnel0 up
2078 brctl addif br-lan vmtunnel0
2081 # on 4.3.2.1
2082 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
2084 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
2087 @end example
2089 @item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2090 @itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
2091 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
2092 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
2093 and MODE @var{octalmode} to change default ownership and permissions for
2094 communication port. This option is only available if QEMU has been compiled
2095 with vde support enabled.
2097 Example:
2098 @example
2099 # launch vde switch
2100 vde_switch -F -sock /tmp/myswitch
2101 # launch QEMU instance
2102 qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
2103 @end example
2105 @item -netdev hubport,id=@var{id},hubid=@var{hubid}
2110 netdev. @code{-net} and @code{-device} with parameter @option{vlan} create the
2111 required hub automatically.
2113 @item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
2115 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
2116 be a unix domain socket backed one. The vhost-user uses a specifically defined
2117 protocol to pass vhost ioctl replacement messages to an application on the other
2118 end of the socket. On non-MSIX guests, the feature can be forced with
2119 @var{vhostforce}. Use 'queues=@var{n}' to specify the number of queues to
2120 be created for multiqueue vhost-user.
2122 Example:
2123 @example
2124 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
2125 -numa node,memdev=mem \
2126 -chardev socket,path=/path/to/socket \
2127 -netdev type=vhost-user,id=net0,chardev=chr0 \
2128 -device virtio-net-pci,netdev=net0
2129 @end example
2131 @item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
2132 Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
2133 At most @var{len} bytes (64k by default) per packet are stored. The file format is
2134 libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
2135 Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
2137 @item -net none
2138 Indicate that no network devices should be configured. It is used to
2139 override the default configuration (@option{-net nic -net user}) which
2140 is activated if no @option{-net} options are provided.
2141 ETEXI
2143 STEXI
2144 @end table
2145 ETEXI
2146 DEFHEADING()
2148 DEFHEADING(Character device options)
2149 STEXI
2151 The general form of a character device option is:
2152 @table @option
2153 ETEXI
2158 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
2172 #ifdef _WIN32
2175 #else
2178 #endif
2179 #ifdef CONFIG_BRLAPI
2181 #endif
2182 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
2183 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
2186 #endif
2187 #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
2190 #endif
2191 #if defined(CONFIG_SPICE)
2194 #endif
2195 , QEMU_ARCH_ALL
2196 )
2198 STEXI
2199 @item -chardev @var{backend} ,id=@var{id} [,mux=on|off] [,@var{options}]
2200 @findex -chardev
2201 Backend is one of:
2202 @option{null},
2203 @option{socket},
2204 @option{udp},
2205 @option{msmouse},
2206 @option{vc},
2207 @option{ringbuf},
2208 @option{file},
2209 @option{pipe},
2210 @option{console},
2211 @option{serial},
2212 @option{pty},
2213 @option{stdio},
2214 @option{braille},
2215 @option{tty},
2216 @option{parallel},
2217 @option{parport},
2218 @option{spicevmc}.
2219 @option{spiceport}.
2220 The specific backend will determine the applicable options.
2224 All devices must have an id, which can be any string up to 127 characters long.
2225 It is used to uniquely identify this device in other command line directives.
2227 A character device may be used in multiplexing mode by multiple front-ends.
2228 Specify @option{mux=on} to enable this mode.
2231 If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
2232 create a multiplexer with your specified ID, and you can then configure multiple
2233 front ends to use that chardev ID for their input/output. Up to four different
2234 front ends can be connected to a single multiplexed chardev. (Without
2235 multiplexing enabled, a chardev can only be used by a single front end.)
2236 For instance you could use this to allow a single stdio chardev to be used by
2237 two serial ports and the QEMU monitor:
2239 @example
2240 -chardev stdio,mux=on,id=char0 \
2241 -mon chardev=char0,mode=readline \
2242 -serial chardev:char0 \
2243 -serial chardev:char0
2244 @end example
2246 You can have more than one multiplexer in a system configuration; for instance
2247 you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
2248 multiplexed between the QEMU monitor and a parallel port:
2250 @example
2251 -chardev stdio,mux=on,id=char0 \
2252 -mon chardev=char0,mode=readline \
2253 -parallel chardev:char0 \
2254 -chardev tcp,...,mux=on,id=char1 \
2255 -serial chardev:char1 \
2256 -serial chardev:char1
2257 @end example
2259 When you're using a multiplexed character device, some escape sequences are
2260 interpreted in the input. @xref{mux_keys, Keys in the character backend
2261 multiplexer}.
2263 Note that some other command line options may implicitly create multiplexed
2264 character backends; for instance @option{-serial mon:stdio} creates a
2265 multiplexed stdio backend connected to the serial port and the QEMU monitor,
2266 and @option{-nographic} also multiplexes the console and the monitor to
2267 stdio.
2269 There is currently no support for multiplexing in the other direction
2270 (where a single QEMU front end takes input and output from multiple chardevs).
2272 Every backend supports the @option{logfile} option, which supplies the path
2273 to a file to record all data transmitted via the backend. The @option{logappend}
2274 option controls whether the log file will be truncated or appended to when
2275 opened.
2277 Further options to each backend are described below.
2279 @item -chardev null ,id=@var{id}
2280 A void device. This device will not emit any data, and will drop any data it
2281 receives. The null backend does not take any options.
2283 @item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,reconnect=@var{seconds}] [,tls-creds=@var{id}]
2285 Create a two-way stream socket, which can be either a TCP or a unix socket. A
2286 unix socket will be created if @option{path} is specified. Behaviour is
2287 undefined if TCP options are specified for a unix socket.
2289 @option{server} specifies that the socket shall be a listening socket.
2291 @option{nowait} specifies that QEMU should not block waiting for a client to
2292 connect to a listening socket.
2294 @option{telnet} specifies that traffic on the socket should interpret telnet
2295 escape sequences.
2297 @option{reconnect} sets the timeout for reconnecting on non-server sockets when
2298 the remote end goes away. qemu will delay this many seconds and then attempt
2299 to reconnect. Zero disables reconnecting, and is the default.
2301 @option{tls-creds} requests enablement of the TLS protocol for encryption,
2302 and specifies the id of the TLS credentials to use for the handshake. The
2303 credentials must be previously created with the @option{-object tls-creds}
2304 argument.
2306 TCP and unix socket options are given below:
2308 @table @option
2310 @item TCP options: port=@var{port} [,host=@var{host}] [,to=@var{to}] [,ipv4] [,ipv6] [,nodelay]
2312 @option{host} for a listening socket specifies the local address to be bound.
2313 For a connecting socket species the remote host to connect to. @option{host} is
2314 optional for listening sockets. If not specified it defaults to @code{0.0.0.0}.
2316 @option{port} for a listening socket specifies the local port to be bound. For a
2317 connecting socket specifies the port on the remote host to connect to.
2318 @option{port} can be given as either a port number or a service name.
2319 @option{port} is required.
2321 @option{to} is only relevant to listening sockets. If it is specified, and
2322 @option{port} cannot be bound, QEMU will attempt to bind to subsequent ports up
2323 to and including @option{to} until it succeeds. @option{to} must be specified
2324 as a port number.
2326 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2327 If neither is specified the socket may use either protocol.
2329 @option{nodelay} disables the Nagle algorithm.
2331 @item unix options: path=@var{path}
2333 @option{path} specifies the local path of the unix socket. @option{path} is
2334 required.
2336 @end table
2338 @item -chardev udp ,id=@var{id} [,host=@var{host}] ,port=@var{port} [,localaddr=@var{localaddr}] [,localport=@var{localport}] [,ipv4] [,ipv6]
2340 Sends all traffic from the guest to a remote host over UDP.
2342 @option{host} specifies the remote host to connect to. If not specified it
2343 defaults to @code{localhost}.
2345 @option{port} specifies the port on the remote host to connect to. @option{port}
2346 is required.
2348 @option{localaddr} specifies the local address to bind to. If not specified it
2349 defaults to @code{0.0.0.0}.
2351 @option{localport} specifies the local port to bind to. If not specified any
2352 available local port will be used.
2354 @option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must be used.
2355 If neither is specified the device may use either protocol.
2357 @item -chardev msmouse ,id=@var{id}
2359 Forward QEMU's emulated msmouse events to the guest. @option{msmouse} does not
2360 take any options.
2362 @item -chardev vc ,id=@var{id} [[,width=@var{width}] [,height=@var{height}]] [[,cols=@var{cols}] [,rows=@var{rows}]]
2364 Connect to a QEMU text console. @option{vc} may optionally be given a specific
2365 size.
2367 @option{width} and @option{height} specify the width and height respectively of
2368 the console, in pixels.
2370 @option{cols} and @option{rows} specify that the console be sized to fit a text
2371 console with the given dimensions.
2373 @item -chardev ringbuf ,id=@var{id} [,size=@var{size}]
2375 Create a ring buffer with fixed size @option{size}.
2376 @var{size} must be a power of two and defaults to @code{64K}.
2378 @item -chardev file ,id=@var{id} ,path=@var{path}
2380 Log all traffic received from the guest to a file.
2382 @option{path} specifies the path of the file to be opened. This file will be
2383 created if it does not already exist, and overwritten if it does. @option{path}
2384 is required.
2386 @item -chardev pipe ,id=@var{id} ,path=@var{path}
2388 Create a two-way connection to the guest. The behaviour differs slightly between
2389 Windows hosts and other hosts:
2391 On Windows, a single duplex pipe will be created at
2394 On other hosts, 2 pipes will be created called @file{@option{path}.in} and
2395 @file{@option{path}.out}. Data written to @file{@option{path}.in} will be
2396 received by the guest. Data written by the guest can be read from
2397 @file{@option{path}.out}. QEMU will not create these fifos, and requires them to
2398 be present.
2400 @option{path} forms part of the pipe path as described above. @option{path} is
2401 required.
2403 @item -chardev console ,id=@var{id}
2405 Send traffic from the guest to QEMU's standard output. @option{console} does not
2406 take any options.
2408 @option{console} is only available on Windows hosts.
2410 @item -chardev serial ,id=@var{id} ,path=@option{path}
2412 Send traffic from the guest to a serial device on the host.
2414 On Unix hosts serial will actually accept any tty device,
2415 not only serial lines.
2417 @option{path} specifies the name of the serial device to open.
2419 @item -chardev pty ,id=@var{id}
2421 Create a new pseudo-terminal on the host and connect to it. @option{pty} does
2422 not take any options.
2424 @option{pty} is not available on Windows hosts.
2426 @item -chardev stdio ,id=@var{id} [,signal=on|off]
2427 Connect to standard input and standard output of the QEMU process.
2429 @option{signal} controls if signals are enabled on the terminal, that includes
2430 exiting QEMU with the key sequence @key{Control-c}. This option is enabled by
2431 default, use @option{signal=off} to disable it.
2433 @item -chardev braille ,id=@var{id}
2435 Connect to a local BrlAPI server. @option{braille} does not take any options.
2437 @item -chardev tty ,id=@var{id} ,path=@var{path}
2439 @option{tty} is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
2440 DragonFlyBSD hosts. It is an alias for @option{serial}.
2442 @option{path} specifies the path to the tty. @option{path} is required.
2444 @item -chardev parallel ,id=@var{id} ,path=@var{path}
2445 @itemx -chardev parport ,id=@var{id} ,path=@var{path}
2447 @option{parallel} is only available on Linux, FreeBSD and DragonFlyBSD hosts.
2449 Connect to a local parallel port.
2451 @option{path} specifies the path to the parallel port device. @option{path} is
2452 required.
2454 @item -chardev spicevmc ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2456 @option{spicevmc} is only available when spice support is built in.
2458 @option{debug} debug level for spicevmc
2460 @option{name} name of spice channel to connect to
2462 Connect to a spice virtual machine channel, such as vdiport.
2464 @item -chardev spiceport ,id=@var{id} ,debug=@var{debug}, name=@var{name}
2466 @option{spiceport} is only available when spice support is built in.
2468 @option{debug} debug level for spicevmc
2470 @option{name} name of spice port to connect to
2472 Connect to a spice port, allowing a Spice client to handle the traffic
2473 identified by a name (preferably a fqdn).
2474 ETEXI
2476 STEXI
2477 @end table
2478 ETEXI
2479 DEFHEADING()
2481 DEFHEADING(Device URL Syntax)
2482 STEXI
2484 In addition to using normal file images for the emulated storage devices,
2485 QEMU can also use networked resources such as iSCSI devices. These are
2486 specified using a special URL syntax.
2488 @table @option
2489 @item iSCSI
2490 iSCSI support allows QEMU to access iSCSI resources directly and use as
2491 images for the guest storage. Both disk and cdrom images are supported.
2493 Syntax for specifying iSCSI LUNs is
2494 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
2496 By default qemu will use the iSCSI initiator-name
2497 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
2498 line or a configuration file.
2500 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
2501 stalled requests and force a reestablishment of the session. The timeout
2502 is specified in seconds. The default is 0 which means no timeout. Libiscsi
2503 1.15.0 or greater is required for this feature.
2505 Example (without authentication):
2506 @example
2507 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
2508 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
2509 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2510 @end example
2512 Example (CHAP username/password via URL):
2513 @example
2514 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
2515 @end example
2517 Example (CHAP username/password via environment variables):
2518 @example
2521 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
2522 @end example
2524 iSCSI support is an optional feature of QEMU and only available when
2525 compiled and linked against libiscsi.
2526 ETEXI
2533 STEXI
2535 iSCSI parameters such as username and password can also be specified via
2536 a configuration file. See qemu-doc for more information and examples.
2538 @item NBD
2539 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
2540 as Unix Domain Sockets.
2542 Syntax for specifying a NBD device using TCP
2543 ``nbd:<server-ip>:<port>[:exportname=<export>]''
2545 Syntax for specifying a NBD device using Unix Domain Sockets
2546 ``nbd:unix:<domain-socket>[:exportname=<export>]''
2549 Example for TCP
2550 @example
2551 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
2552 @end example
2554 Example for Unix Domain Sockets
2555 @example
2556 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
2557 @end example
2559 @item SSH
2560 QEMU supports SSH (Secure Shell) access to remote disks.
2562 Examples:
2563 @example
2564 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
2565 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
2566 @end example
2568 Currently authentication must be done using ssh-agent. Other
2569 authentication methods may be supported in future.
2571 @item Sheepdog
2572 Sheepdog is a distributed storage system for QEMU.
2573 QEMU supports using either local sheepdog devices or remote networked
2574 devices.
2576 Syntax for specifying a sheepdog device
2577 @example
2578 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
2579 @end example
2581 Example
2582 @example
2583 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
2584 @end example
2586 See also @url{http://http://www.osrg.net/sheepdog/}.
2588 @item GlusterFS
2589 GlusterFS is a user space distributed file system.
2590 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
2591 TCP, Unix Domain Sockets and RDMA transport protocols.
2593 Syntax for specifying a VM disk image on GlusterFS volume is
2594 @example
2596 URI:
2597 gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
2599 JSON:
2600 'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
2603 @end example
2606 Example
2607 @example
2608 URI:
2609 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
2610 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log
2612 JSON:
2619 qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
2620 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log,
2621 @ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
2622 @ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
2623 @end example
2625 See also @url{http://www.gluster.org}.
2627 @item HTTP/HTTPS/FTP/FTPS
2628 QEMU supports read-only access to files accessed over http(s) and ftp(s).
2630 Syntax using a single filename:
2631 @example
2632 <protocol>://[<username>[:<password>]@@]<host>/<path>
2633 @end example
2635 where:
2636 @table @option
2637 @item protocol
2638 'http', 'https', 'ftp', or 'ftps'.
2640 @item username
2641 Optional username for authentication to the remote server.
2643 @item password
2644 Optional password for authentication to the remote server.
2646 @item host
2647 Address of the remote server.
2649 @item path
2650 Path on the remote server, including any query string.
2651 @end table
2653 The following options are also supported:
2654 @table @option
2655 @item url
2656 The full URL when passing options to the driver explicitly.
2658 @item readahead
2659 The amount of data to read ahead with each range request to the remote server.
2660 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
2661 does not have a suffix, it will be assumed to be in bytes. The value must be a
2662 multiple of 512 bytes. It defaults to 256k.
2664 @item sslverify
2665 Whether to verify the remote server's certificate when connecting over SSL. It
2666 can have the value 'on' or 'off'. It defaults to 'on'.
2668 @item cookie
2669 Send this cookie (it can also be a list of cookies separated by ';') with
2670 each outgoing request. Only supported when using protocols such as HTTP
2671 which support cookies, otherwise ignored.
2673 @item timeout
2674 Set the timeout in seconds of the CURL connection. This timeout is the time
2675 that CURL waits for a response from the remote server to get the size of the
2676 image to be downloaded. If not set, the default timeout of 5 seconds is used.
2677 @end table
2679 Note that when passing options to qemu explicitly, @option{driver} is the value
2680 of <protocol>.
2682 Example: boot from a remote Fedora 20 live ISO image
2683 @example
2684 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
2686 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
2687 @end example
2689 Example: boot from a remote Fedora 20 cloud image using a local overlay for
2690 writes, copy-on-read, and a readahead of 64k
2691 @example
2692 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
2695 @end example
2700 @example
2701 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
2704 @end example
2705 ETEXI
2707 STEXI
2708 @end table
2709 ETEXI
2712 STEXI
2713 @table @option
2714 ETEXI
2726 QEMU_ARCH_ALL)
2727 STEXI
2729 @findex -bt
2732 example when emulating a machine with only one HCI built into it, only
2734 logic. The Transport Layer is decided by the machine type. Currently
2735 the machines @code{n800} and @code{n810} have one HCI and all other
2736 machines have none.
2738 @anchor{bt-hcis}
2739 The following three types are recognized:
2741 @table @option
2742 @item -bt hci,null
2743 (default) The corresponding Bluetooth HCI assumes no internal logic
2744 and will not respond to any HCI commands or emit events.
2746 @item -bt hci,host[:@var{id}]
2747 (@code{bluez} only) The corresponding HCI passes commands / events
2748 to / from the physical HCI identified by the name @var{id} (default:
2749 @code{hci0}) on the computer running QEMU. Only available on @code{bluez}
2750 capable systems like Linux.
2752 @item -bt hci[,vlan=@var{n}]
2753 Add a virtual, standard HCI that will participate in the Bluetooth
2754 scatternet @var{n} (default @code{0}). Similarly to @option{-net}
2755 VLANs, devices inside a bluetooth network @var{n} can only communicate
2756 with other devices in the same network (scatternet).
2757 @end table
2759 @item -bt vhci[,vlan=@var{n}]
2760 (Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
2761 to the host bluetooth stack instead of to the emulated target. This
2762 allows the host and target machines to participate in a common scatternet
2763 and communicate. Requires the Linux @code{vhci} driver installed. Can
2764 be used as following:
2766 @example
2767 qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
2768 @end example
2770 @item -bt device:@var{dev}[,vlan=@var{n}]
2771 Emulate a bluetooth device @var{dev} and place it in network @var{n}
2772 (default @code{0}). QEMU can only emulate one type of bluetooth devices
2773 currently:
2775 @table @option
2776 @item keyboard
2777 Virtual wireless keyboard implementing the HIDP bluetooth profile.
2778 @end table
2779 ETEXI
2781 STEXI
2782 @end table
2783 ETEXI
2784 DEFHEADING()
2786 #ifdef CONFIG_TPM
2787 DEFHEADING(TPM device options)
2789 DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
2794 QEMU_ARCH_ALL)
2795 STEXI
2797 The general form of a TPM device option is:
2798 @table @option
2800 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
2801 @findex -tpmdev
2802 Backend type must be:
2803 @option{passthrough}.
2805 The specific backend type will determine the applicable options.
2806 The @code{-tpmdev} option creates the TPM backend and requires a
2807 @code{-device} option that specifies the TPM frontend interface model.
2809 Options to each backend are described below.
2811 Use 'help' to print all available TPM backend types.
2812 @example
2813 qemu -tpmdev help
2814 @end example
2816 @item -tpmdev passthrough, id=@var{id}, path=@var{path}, cancel-path=@var{cancel-path}
2818 (Linux-host only) Enable access to the host's TPM using the passthrough
2819 driver.
2821 @option{path} specifies the path to the host's TPM device, i.e., on
2822 a Linux host this would be @code{/dev/tpm0}.
2823 @option{path} is optional and by default @code{/dev/tpm0} is used.
2825 @option{cancel-path} specifies the path to the host TPM device's sysfs
2826 entry allowing for cancellation of an ongoing TPM command.
2827 @option{cancel-path} is optional and by default QEMU will search for the
2828 sysfs entry to use.
2830 Some notes about using the host's TPM with the passthrough driver:
2832 The TPM device accessed by the passthrough driver must not be
2833 used by any other application on the host.
2835 Since the host's firmware (BIOS/UEFI) has already initialized the TPM,
2836 the VM's firmware (BIOS/UEFI) will not be able to initialize the
2837 TPM again and may therefore not show a TPM-specific menu that would
2838 otherwise allow the user to configure the TPM, e.g., allow the user to
2839 enable/disable or activate/deactivate the TPM.
2840 Further, if TPM ownership is released from within a VM then the host's TPM
2841 will get disabled and deactivated. To enable and activate the
2842 TPM again afterwards, the host has to be rebooted and the user is
2843 required to enter the firmware's menu to enable and activate the TPM.
2844 If the TPM is left disabled and/or deactivated most TPM commands will fail.
2846 To create a passthrough TPM use the following two options:
2847 @example
2848 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
2849 @end example
2850 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
2851 @code{tpmdev=tpm0} in the device option.
2853 @end table
2855 ETEXI
2857 DEFHEADING()
2859 #endif
2861 DEFHEADING(Linux/Multiboot boot specific)
2862 STEXI
2864 When using these options, you can use a given Linux or Multiboot
2865 kernel without installing it in the disk image. It can be useful
2866 for easier testing of various kernels.
2868 @table @option
2869 ETEXI
2873 STEXI
2874 @item -kernel @var{bzImage}
2875 @findex -kernel
2876 Use @var{bzImage} as kernel image. The kernel can be either a Linux kernel
2877 or in multiboot format.
2878 ETEXI
2882 STEXI
2883 @item -append @var{cmdline}
2884 @findex -append
2885 Use @var{cmdline} as kernel command line
2886 ETEXI
2890 STEXI
2891 @item -initrd @var{file}
2892 @findex -initrd
2893 Use @var{file} as initial ram disk.
2897 This syntax is only available with multiboot.
2899 Use @var{file1} and @var{file2} as modules and pass arg=foo as parameter to the
2900 first module.
2901 ETEXI
2905 STEXI
2906 @item -dtb @var{file}
2907 @findex -dtb
2908 Use @var{file} as a device tree binary (dtb) image and pass it to the kernel
2909 on boot.
2910 ETEXI
2912 STEXI
2913 @end table
2914 ETEXI
2915 DEFHEADING()
2917 DEFHEADING(Debug/Expert options)
2918 STEXI
2919 @table @option
2920 ETEXI
2927 QEMU_ARCH_ALL)
2928 STEXI
2930 @item -fw_cfg [name=]@var{name},file=@var{file}
2931 @findex -fw_cfg
2932 Add named fw_cfg entry with contents from file @var{file}.
2934 @item -fw_cfg [name=]@var{name},string=@var{str}
2935 Add named fw_cfg entry with contents from string @var{str}.
2937 The terminating NUL character of the contents of @var{str} will not be
2938 included as part of the fw_cfg item data. To insert contents with
2939 embedded NUL characters, you have to use the @var{file} parameter.
2941 The fw_cfg entries are passed by QEMU through to the guest.
2943 Example:
2944 @example
2945 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
2946 @end example
2947 creates an fw_cfg entry named opt/com.mycompany/blob with contents
2948 from ./my_blob.bin.
2950 ETEXI
2954 QEMU_ARCH_ALL)
2955 STEXI
2956 @item -serial @var{dev}
2957 @findex -serial
2958 Redirect the virtual serial port to host character device
2959 @var{dev}. The default device is @code{vc} in graphical mode and
2960 @code{stdio} in non graphical mode.
2962 This option can be used several times to simulate up to 4 serial
2963 ports.
2965 Use @code{-serial none} to disable all serial ports.
2967 Available character devices are:
2968 @table @option
2969 @item vc[:@var{W}x@var{H}]
2970 Virtual console. Optionally, a width and height can be given in pixel with
2971 @example
2972 vc:800x600
2973 @end example
2974 It is also possible to specify width or height in characters:
2975 @example
2976 vc:80Cx24C
2977 @end example
2978 @item pty
2979 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
2980 @item none
2981 No device is allocated.
2982 @item null
2983 void device
2984 @item chardev:@var{id}
2985 Use a named character device defined with the @code{-chardev} option.
2986 @item /dev/XXX
2987 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
2988 parameters are set according to the emulated ones.
2989 @item /dev/parport@var{N}
2990 [Linux only, parallel port only] Use host parallel port
2991 @var{N}. Currently SPP and EPP parallel port features can be used.
2992 @item file:@var{filename}
2993 Write output to @var{filename}. No character can be read.
2994 @item stdio
2995 [Unix only] standard input/output
2996 @item pipe:@var{filename}
2997 name pipe @var{filename}
2998 @item COM@var{n}
2999 [Windows only] Use host serial port @var{n}
3000 @item udp:[@var{remote_host}]:@var{remote_port}[@@[@var{src_ip}]:@var{src_port}]
3001 This implements UDP Net Console.
3002 When @var{remote_host} or @var{src_ip} are not specified
3003 they default to @code{0.0.0.0}.
3004 When not using a specified @var{src_port} a random port is automatically chosen.
3006 If you just want a simple readonly console you can use @code{netcat} or
3007 @code{nc}, by starting QEMU with: @code{-serial udp::4555} and nc as:
3008 @code{nc -u -l -p 4555}. Any time QEMU writes something to that port it
3009 will appear in the netconsole session.
3011 If you plan to send characters back via netconsole or you want to stop
3012 and start QEMU a lot of times, you should have QEMU use the same
3013 source port each time by using something like @code{-serial
3014 udp::4555@@:4556} to QEMU. Another approach is to use a patched
3015 version of netcat which can listen to a TCP port and send and receive
3016 characters via udp. If you have a patched version of netcat which
3017 activates telnet remote echo and single char transfer, then you can
3018 use the following options to set up a netcat redirector to allow
3019 telnet on port 5555 to access the QEMU port.
3020 @table @code
3021 @item QEMU Options:
3022 -serial udp::4555@@:4556
3023 @item netcat options:
3024 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
3025 @item telnet options:
3026 localhost 5555
3027 @end table
3029 @item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
3030 The TCP Net Console has two modes of operation. It can send the serial
3031 I/O to a location or wait for a connection from a location. By default
3032 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
3033 the @var{server} option QEMU will wait for a client socket application
3034 to connect to the port before continuing, unless the @code{nowait}
3035 option was specified. The @code{nodelay} option disables the Nagle buffering
3036 algorithm. The @code{reconnect} option only applies if @var{noserver} is
3037 set, if the connection goes down it will attempt to reconnect at the
3038 given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only
3039 one TCP connection at a time is accepted. You can use @code{telnet} to
3040 connect to the corresponding character device.
3041 @table @code
3042 @item Example to send tcp console to 192.168.0.2 port 4444
3043 -serial tcp:192.168.0.2:4444
3044 @item Example to listen and wait on port 4444 for connection
3045 -serial tcp::4444,server
3046 @item Example to not wait and listen on ip 192.168.0.100 port 4444
3047 -serial tcp:192.168.0.100:4444,server,nowait
3048 @end table
3050 @item telnet:@var{host}:@var{port}[,server][,nowait][,nodelay]
3051 The telnet protocol is used instead of raw tcp sockets. The options
3052 work the same as if you had specified @code{-serial tcp}. The
3053 difference is that the port acts like a telnet server or client using
3054 telnet option negotiation. This will also allow you to send the
3055 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
3056 sequence. Typically in unix telnet you do it with Control-] and then
3059 @item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
3060 A unix domain socket is used instead of a tcp socket. The option works the
3061 same as if you had specified @code{-serial tcp} except the unix domain socket
3062 @var{path} is used for connections.
3064 @item mon:@var{dev_string}
3065 This is a special option to allow the monitor to be multiplexed onto
3066 another serial port. The monitor is accessed with key sequence of
3067 @key{Control-a} and then pressing @key{c}.
3068 @var{dev_string} should be any one of the serial devices specified
3069 above. An example to multiplex the monitor onto a telnet server
3070 listening on port 4444 would be:
3071 @table @code
3072 @item -serial mon:telnet::4444,server,nowait
3073 @end table
3074 When the monitor is multiplexed to stdio in this way, Ctrl+C will not terminate
3075 QEMU any more but will be passed to the guest instead.
3077 @item braille
3078 Braille device. This will use BrlAPI to display the braille output on a real
3079 or fake device.
3081 @item msmouse
3082 Three button serial mouse. Configure the guest to use Microsoft protocol.
3083 @end table
3084 ETEXI
3088 QEMU_ARCH_ALL)
3089 STEXI
3090 @item -parallel @var{dev}
3091 @findex -parallel
3092 Redirect the virtual parallel port to host device @var{dev} (same
3093 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
3094 be used to use hardware devices connected on the corresponding host
3095 parallel port.
3097 This option can be used several times to simulate up to 3 parallel
3098 ports.
3100 Use @code{-parallel none} to disable all parallel ports.
3101 ETEXI
3105 QEMU_ARCH_ALL)
3106 STEXI
3107 @item -monitor @var{dev}
3108 @findex -monitor
3109 Redirect the monitor to host device @var{dev} (same devices as the
3110 serial port).
3111 The default device is @code{vc} in graphical mode and @code{stdio} in
3112 non graphical mode.
3113 Use @code{-monitor none} to disable the default monitor.
3114 ETEXI
3117 QEMU_ARCH_ALL)
3118 STEXI
3119 @item -qmp @var{dev}
3120 @findex -qmp
3121 Like -monitor but opens in 'control' mode.
3122 ETEXI
3125 QEMU_ARCH_ALL)
3126 STEXI
3127 @item -qmp-pretty @var{dev}
3128 @findex -qmp-pretty
3129 Like -qmp but uses pretty JSON formatting.
3130 ETEXI
3134 STEXI
3135 @item -mon [chardev=]name[,mode=readline|control]
3136 @findex -mon
3137 Setup monitor on chardev @var{name}.
3138 ETEXI
3142 QEMU_ARCH_ALL)
3143 STEXI
3144 @item -debugcon @var{dev}
3145 @findex -debugcon
3146 Redirect the debug console to host device @var{dev} (same devices as the
3147 serial port). The debug console is an I/O port which is typically port
3148 0xe9; writing to that I/O port sends output to this device.
3149 The default device is @code{vc} in graphical mode and @code{stdio} in
3150 non graphical mode.
3151 ETEXI
3155 STEXI
3156 @item -pidfile @var{file}
3157 @findex -pidfile
3158 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
3159 from a script.
3160 ETEXI
3164 STEXI
3165 @item -singlestep
3166 @findex -singlestep
3167 Run the emulation in single step mode.
3168 ETEXI
3172 QEMU_ARCH_ALL)
3173 STEXI
3174 @item -S
3175 @findex -S
3176 Do not start CPU at startup (you must type 'c' in the monitor).
3177 ETEXI
3183 QEMU_ARCH_ALL)
3184 STEXI
3185 @item -realtime mlock=on|off
3186 @findex -realtime
3187 Run qemu with realtime features.
3188 mlocking qemu and guest memory can be enabled via @option{mlock=on}
3189 (enabled by default).
3190 ETEXI
3194 STEXI
3195 @item -gdb @var{dev}
3196 @findex -gdb
3197 Wait for gdb connection on device @var{dev} (@pxref{gdb_usage}). Typical
3198 connections will likely be TCP-based, but also UDP, pseudo TTY, or even
3199 stdio are reasonable use case. The latter is allowing to start QEMU from
3200 within gdb and establish the connection via a pipe:
3201 @example
3202 (gdb) target remote | exec qemu-system-i386 -gdb stdio ...
3203 @end example
3204 ETEXI
3208 QEMU_ARCH_ALL)
3209 STEXI
3210 @item -s
3211 @findex -s
3212 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
3213 (@pxref{gdb_usage}).
3214 ETEXI
3218 QEMU_ARCH_ALL)
3219 STEXI
3220 @item -d @var{item1}[,...]
3221 @findex -d
3222 Enable logging of specified items. Use '-d help' for a list of log items.
3223 ETEXI
3227 QEMU_ARCH_ALL)
3228 STEXI
3229 @item -D @var{logfile}
3230 @findex -D
3231 Output log in @var{logfile} instead of to stderr
3232 ETEXI
3235 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
3236 QEMU_ARCH_ALL)
3237 STEXI
3238 @item -dfilter @var{range1}[,...]
3239 @findex -dfilter
3240 Filter debug output to that relevant to a range of target addresses. The filter
3241 spec can be either @var{start}+@var{size}, @var{start}-@var{size} or
3242 @var{start}..@var{end} where @var{start} @var{end} and @var{size} are the
3243 addresses and sizes required. For example:
3244 @example
3245 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
3246 @end example
3247 Will dump output for any code in the 0x1000 sized block starting at 0x8000 and
3248 the 0x200 sized block starting at 0xffffffc000080000 and another 0x1000 sized
3249 block starting at 0xffffffc00005f000.
3250 ETEXI
3254 QEMU_ARCH_ALL)
3255 STEXI
3256 @item -L @var{path}
3257 @findex -L
3258 Set the directory for the BIOS, VGA BIOS and keymaps.
3260 To list all the data directories, use @code{-L help}.
3261 ETEXI
3265 STEXI
3266 @item -bios @var{file}
3267 @findex -bios
3268 Set the filename for the BIOS.
3269 ETEXI
3273 STEXI
3274 @item -enable-kvm
3275 @findex -enable-kvm
3276 Enable KVM full virtualization support. This option is only available
3277 if KVM support is enabled when compiling.
3278 ETEXI
3282 STEXI
3283 @item -enable-hax
3284 @findex -enable-hax
3285 Enable HAX (Hardware-based Acceleration eXecution) support. This option
3286 is only available if HAX support is enabled when compiling. HAX is only
3287 applicable to MAC and Windows platform, and thus does not conflict with
3288 KVM.
3289 ETEXI
3296 QEMU_ARCH_ALL)
3300 QEMU_ARCH_ALL)
3301 STEXI
3302 @item -xen-domid @var{id}
3303 @findex -xen-domid
3304 Specify xen guest domain @var{id} (XEN only).
3305 @item -xen-create
3306 @findex -xen-create
3307 Create domain using xen hypercalls, bypassing xend.
3308 Warning: should not be used when xend is in use (XEN only).
3309 @item -xen-attach
3310 @findex -xen-attach
3311 Attach to existing xen domain.
3312 xend will use this when starting QEMU (XEN only).
3313 ETEXI
3317 STEXI
3318 @item -no-reboot
3319 @findex -no-reboot
3320 Exit instead of rebooting.
3321 ETEXI
3325 STEXI
3326 @item -no-shutdown
3327 @findex -no-shutdown
3328 Don't exit QEMU on guest shutdown, but instead only stop the emulation.
3329 This allows for instance switching to monitor to commit changes to the
3330 disk image.
3331 ETEXI
3336 QEMU_ARCH_ALL)
3337 STEXI
3338 @item -loadvm @var{file}
3339 @findex -loadvm
3340 Start right away with a saved state (@code{loadvm} in monitor)
3341 ETEXI
3343 #ifndef _WIN32
3346 #endif
3347 STEXI
3348 @item -daemonize
3349 @findex -daemonize
3350 Daemonize the QEMU process after initialization. QEMU will not detach from
3351 standard IO until it is ready to receive connections on any of its devices.
3352 This option is a useful way for external programs to launch QEMU without having
3353 to cope with initialization race conditions.
3354 ETEXI
3358 QEMU_ARCH_ALL)
3359 STEXI
3360 @item -option-rom @var{file}
3361 @findex -option-rom
3362 Load the contents of @var{file} as an option ROM.
3363 This option is useful to load things like EtherBoot.
3364 ETEXI
3366 HXCOMM Silently ignored for compatibility
3369 HXCOMM Options deprecated by -rtc
3376 QEMU_ARCH_ALL)
3378 STEXI
3380 @item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
3381 @findex -rtc
3382 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
3383 UTC or local time, respectively. @code{localtime} is required for correct date in
3384 MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
3385 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
3387 By default the RTC is driven by the host system time. This allows using of the
3388 RTC as accurate reference clock inside the guest, specifically if the host
3389 time is smoothly following an accurate external reference clock, e.g. via NTP.
3390 If you want to isolate the guest time from the host, you can set @option{clock}
3391 to @code{rt} instead. To even prevent it from progressing during suspension,
3392 you can set it to @code{vm}.
3394 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
3395 specifically with Windows' ACPI HAL. This option will try to figure out how
3396 many timer interrupts were not processed by the Windows guest and will
3397 re-inject them.
3398 ETEXI
3401 "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
3405 STEXI
3406 @item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}]
3407 @findex -icount
3408 Enable virtual instruction counter. The virtual cpu will execute one
3409 instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified
3410 then the virtual cpu speed will be automatically adjusted to keep virtual
3411 time within a few seconds of real time.
3413 When the virtual cpu is sleeping, the virtual time will advance at default
3414 speed unless @option{sleep=on|off} is specified.
3415 With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
3416 instantly whenever the virtual cpu goes to sleep mode and will not advance
3417 if no timer is enabled. This behavior give deterministic execution times from
3418 the guest point of view.
3420 Note that while this option can give deterministic behavior, it does not
3421 provide cycle accurate emulation. Modern CPUs contain superscalar out of
3422 order cores with complex cache hierarchies. The number of instructions
3423 executed often has little or no correlation with actual performance.
3425 @option{align=on} will activate the delay algorithm which will try
3426 to synchronise the host clock and the virtual clock. The goal is to
3427 have a guest running at the real frequency imposed by the shift option.
3428 Whenever the guest clock is behind the host clock and if
3429 @option{align=on} is specified then we print a message to the user
3430 to inform about the delay.
3431 Currently this option does not work when @option{shift} is @code{auto}.
3432 Note: The sync algorithm will work for those shift values for which
3433 the guest clock runs ahead of the host clock. Typically this happens
3434 when the shift value is high (how high depends on the host machine).
3436 When @option{rr} option is specified deterministic record/replay is enabled.
3437 Replay log is written into @var{filename} file in record mode and
3438 read from this file in replay mode.
3440 Option rrsnapshot is used to create new vm snapshot named @var{snapshot}
3441 at the start of execution recording. In replay mode this option is used
3442 to load the initial VM state.
3443 ETEXI
3448 QEMU_ARCH_ALL)
3449 STEXI
3450 @item -watchdog @var{model}
3451 @findex -watchdog
3452 Create a virtual hardware watchdog device. Once enabled (by a guest
3453 action), the watchdog must be periodically polled by an agent inside
3454 the guest or else the guest will be restarted. Choose a model for
3455 which your guest has drivers.
3457 The @var{model} is the model of hardware watchdog to emulate. Use
3458 @code{-watchdog help} to list available hardware models. Only one
3459 watchdog can be enabled for a guest.
3461 The following models may be available:
3462 @table @option
3463 @item ib700
3464 iBASE 700 is a very simple ISA watchdog with a single timer.
3465 @item i6300esb
3466 Intel 6300ESB I/O controller hub is a much more featureful PCI-based
3467 dual-timer watchdog.
3468 @item diag288
3469 A virtual watchdog for s390x backed by the diagnose 288 hypercall
3470 (currently KVM only).
3471 @end table
3472 ETEXI
3477 QEMU_ARCH_ALL)
3478 STEXI
3479 @item -watchdog-action @var{action}
3480 @findex -watchdog-action
3482 The @var{action} controls what QEMU will do when the watchdog timer
3483 expires.
3484 The default is
3485 @code{reset} (forcefully reset the guest).
3486 Other possible actions are:
3487 @code{shutdown} (attempt to gracefully shutdown the guest),
3488 @code{poweroff} (forcefully poweroff the guest),
3489 @code{pause} (pause the guest),
3490 @code{debug} (print a debug message and continue), or
3491 @code{none} (do nothing).
3493 Note that the @code{shutdown} action requires that the guest responds
3494 to ACPI signals, which it may not be able to do in the sort of
3495 situations where the watchdog would have expired, and thus
3496 @code{-watchdog-action shutdown} is not recommended for production use.
3498 Examples:
3500 @table @code
3501 @item -watchdog i6300esb -watchdog-action pause
3502 @itemx -watchdog ib700
3503 @end table
3504 ETEXI
3508 QEMU_ARCH_ALL)
3509 STEXI
3511 @item -echr @var{numeric_ascii_value}
3512 @findex -echr
3513 Change the escape character used for switching to the monitor when using
3514 monitor and serial sharing. The default is @code{0x01} when using the
3515 @code{-nographic} option. @code{0x01} is equal to pressing
3516 @code{Control-a}. You can select a different character from the ascii
3517 control keys where 1 through 26 map to Control-a through Control-z. For
3518 instance you could use the either of the following to change the escape
3519 character to Control-t.
3520 @table @code
3521 @item -echr 0x14
3522 @itemx -echr 20
3523 @end table
3524 ETEXI
3529 STEXI
3530 @item -virtioconsole @var{c}
3531 @findex -virtioconsole
3532 Set virtio console.
3534 This option is maintained for backward compatibility.
3536 Please use @code{-device virtconsole} for the new way of invocation.
3537 ETEXI
3541 STEXI
3542 @item -show-cursor
3543 @findex -show-cursor
3544 Show cursor.
3545 ETEXI
3549 STEXI
3550 @item -tb-size @var{n}
3551 @findex -tb-size
3552 Set TB size.
3553 ETEXI
3567 QEMU_ARCH_ALL)
3568 STEXI
3569 @item -incoming tcp:[@var{host}]:@var{port}[,to=@var{maxport}][,ipv4][,ipv6]
3570 @itemx -incoming rdma:@var{host}:@var{port}[,ipv4][,ipv6]
3571 @findex -incoming
3572 Prepare for incoming migration, listen on a given tcp port.
3574 @item -incoming unix:@var{socketpath}
3575 Prepare for incoming migration, listen on a given unix socket.
3577 @item -incoming fd:@var{fd}
3578 Accept incoming migration from a given filedescriptor.
3580 @item -incoming exec:@var{cmdline}
3581 Accept incoming migration as an output from specified external command.
3583 @item -incoming defer
3584 Wait for the URI to be specified via migrate_incoming. The monitor can
3585 be used to change settings (such as migration parameters) prior to issuing
3586 the migrate_incoming to allow the migration to begin.
3587 ETEXI
3591 STEXI
3592 @item -only-migratable
3593 @findex -only-migratable
3594 Only allow migratable devices. Devices will not be allowed to enter an
3595 unmigratable state.
3596 ETEXI
3600 STEXI
3601 @item -nodefaults
3602 @findex -nodefaults
3607 ETEXI
3609 #ifndef _WIN32
3612 QEMU_ARCH_ALL)
3613 #endif
3614 STEXI
3616 @findex -chroot
3617 Immediately before starting guest execution, chroot to the specified
3619 ETEXI
3621 #ifndef _WIN32
3624 QEMU_ARCH_ALL)
3625 #endif
3626 STEXI
3628 @findex -runas
3630 to the specified user.
3631 ETEXI
3636 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
3637 STEXI
3641 ETEXI
3644 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3645 QEMU_ARCH_MIPS)
3646 STEXI
3647 @item -semihosting
3648 @findex -semihosting
3650 ETEXI
3654 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA | QEMU_ARCH_LM32 |
3655 QEMU_ARCH_MIPS)
3656 STEXI
3660 @table @option
3666 Allows the user to pass input arguments, and can be used multiple times to build
3671 @end table
3672 ETEXI
3675 STEXI
3679 ETEXI
3683 QEMU_ARCH_ALL)
3684 STEXI
3686 @findex -sandbox
3689 ETEXI
3693 STEXI
3695 @findex -readconfig
3697 QEMU process with many command line options but you don't want to exceed the command line
3698 character limit.
3699 ETEXI
3700 DEF("writeconfig", HAS_ARG, QEMU_OPTION_writeconfig,
3703 STEXI
3704 @item -writeconfig @var{file}
3705 @findex -writeconfig
3706 Write device configuration to @var{file}. The @var{file} can be either filename to save
3707 command line and device configuration into file or dash @code{-}) character to print the
3708 output to stdout. This can be later used as input file for @code{-readconfig} option.
3709 ETEXI
3710 DEF("nodefconfig", 0, QEMU_OPTION_nodefconfig,
3713 QEMU_ARCH_ALL)
3714 STEXI
3715 @item -nodefconfig
3716 @findex -nodefconfig
3717 Normally QEMU loads configuration files from @var{sysconfdir} and @var{datadir} at startup.
3718 The @code{-nodefconfig} option will prevent QEMU from loading any of those config files.
3719 ETEXI
3720 DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
3723 QEMU_ARCH_ALL)
3724 STEXI
3725 @item -no-user-config
3726 @findex -no-user-config
3727 The @code{-no-user-config} option makes QEMU not load any of the user-provided
3730 ETEXI
3734 QEMU_ARCH_ALL)
3735 STEXI
3737 HXCOMM HX does not support conditional compilation of text.
3741 ETEXI
3743 HXCOMM Internal use
3747 #ifdef __linux__
3750 QEMU_ARCH_ALL)
3751 #endif
3752 STEXI
3756 ETEXI
3761 HXCOMM Deprecated by kvm-pit driver properties
3778 QEMU_ARCH_ALL)
3779 STEXI
3781 @findex -msg
3783 ETEXI
3791 QEMU_ARCH_ALL)
3792 STEXI
3797 ETEXI
3799 STEXI
3800 @end table
3801 ETEXI
3804 STEXI
3805 @table @option
3806 ETEXI
3814 QEMU_ARCH_ALL)
3815 STEXI
3817 @findex -object
3823 @table @option
3825 @item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
3827 Creates a memory file backend object, which can be used to back
3829 unique ID that will be used to reference this memory region
3831 option provides the size of the memory region, and accepts
3833 the path to either a shared memory or huge page filesystem mount.
3840 Creates a random number generator backend which obtains entropy from
3848 Creates a random number generator backend which obtains entropy from
3850 a unique ID that will be used to reference this entropy backend from
3852 the unique ID of a character device backend that provides the connection
3853 to the RNG daemon.
3855 @item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
3857 Creates a TLS anonymous credentials object, which can be used to provide
3859 ID which network backends will use to access the credentials. The
3861 on whether the QEMU network backend that uses the credentials will be
3870 a set of DH parameters at startup. This is a computationally
3871 expensive operation that consumes random pool entropy, so it is
3872 recommended that a persistent set of parameters be generated
3873 upfront and saved.
3875 @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}
3877 Creates a TLS anonymous credentials object, which can be used to provide
3879 ID which network backends will use to access the credentials. The
3881 on whether the QEMU network backend that uses the credentials will be
3885 must be provided with valid client certificates too.
3891 a set of DH parameters at startup. This is a computationally
3892 expensive operation that consumes random pool entropy, so it is
3893 recommended that a persistent set of parameters be generated
3894 upfront and saved.
3896 For x509 certificate credentials the directory will contain further files
3897 providing the x509 certificates. The certificates must be stored
3908 @item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
3911 packets arriving in a given interval on netdev @var{netdevid} are delayed
3912 until the end of the interval. Interval is in microseconds.
3913 @option{status} is optional that indicate whether the netfilter is
3916 queue @var{all|rx|tx} is an option that can be applied to any netfilter.
3918 @option{all}: the filter is attached both to the receive and the transmit
3919 queue of the netdev (default).
3921 @option{rx}: the filter is attached to the receive queue of the netdev,
3922 where it will receive packets sent to the netdev.
3924 @option{tx}: the filter is attached to the transmit queue of the netdev,
3925 where it will receive packets sent by the netdev.
3927 @item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
3929 filter-mirror on netdev @var{netdevid},mirror net packet to chardev
3930 @var{chardevid}
3932 @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},
3933 outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
3935 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
3937 Create a filter-redirector we need to differ outdev id from indev id, id can not
3938 be the same. we can just use indev or outdev, but at least one of indev or outdev
3939 need to be specified.
3941 @item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},rewriter-mode=@var{mode}[,queue=@var{all|rx|tx}]
3943 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
3944 secondary from primary to keep secondary tcp connection,and rewrite
3945 tcp packet to primary from secondary make tcp packet can be handled by
3946 client.
3948 usage:
3949 colo secondary:
3950 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
3951 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
3952 -object filter-rewriter,id=rew0,netdev=hn0,queue=all
3954 @item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
3956 Dump the network traffic on netdev @var{dev} to the file specified by
3957 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
3958 The file format is libpcap, so it can be analyzed with tools such as tcpdump
3959 or Wireshark.
3961 @item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},
3962 outdev=@var{chardevid}
3964 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
3965 secondary packet. If the packets are same, we will output primary
3966 packet to outdev@var{chardevid}, else we will notify colo-frame
3967 do checkpoint and send primary packet to outdev@var{chardevid}.
3969 we must use it with the help of filter-mirror and filter-redirector.
3971 @example
3973 primary:
3974 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
3975 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
3976 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
3977 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
3978 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
3979 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
3980 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
3981 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
3982 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
3983 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
3984 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
3985 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
3987 secondary:
3988 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
3989 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
3990 -chardev socket,id=red0,host=3.3.3.3,port=9003
3991 -chardev socket,id=red1,host=3.3.3.3,port=9004
3992 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
3993 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
3995 @end example
3997 If you want to know the detail of above command line, you can read
3998 the colo-compare git log.
4000 @item -object cryptodev-backend-builtin,id=@var{id}[,queues=@var{queues}]
4002 Creates a cryptodev backend which executes crypto opreation from
4003 the QEMU cipher APIS. The @var{id} parameter is
4004 a unique ID that will be used to reference this cryptodev backend from
4005 the @option{virtio-crypto} device. The @var{queues} parameter is optional,
4006 which specify the queue number of cryptodev backend, the default of
4007 @var{queues} is 1.
4009 @example
4011 # qemu-system-x86_64 \
4012 [...] \
4013 -object cryptodev-backend-builtin,id=cryptodev0 \
4014 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
4015 [...]
4016 @end example
4018 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4019 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
4021 Defines a secret to store a password, encryption key, or some other sensitive
4022 data. The sensitive data can either be passed directly via the @var{data}
4023 parameter, or indirectly via the @var{file} parameter. Using the @var{data}
4024 parameter is insecure unless the sensitive data is encrypted.
4026 The sensitive data can be provided in raw format (the default), or base64.
4027 When encoded as JSON, the raw format only supports valid UTF-8 characters,
4028 so base64 is recommended for sending binary data. QEMU will convert from
4029 which ever format is provided to the format it needs internally. eg, an
4030 RBD password can be provided in raw format, even though it will be base64
4031 encoded when passed onto the RBD sever.
4033 For added protection, it is possible to encrypt the data associated with
4034 a secret using the AES-256-CBC cipher. Use of encryption is indicated
4035 by providing the @var{keyid} and @var{iv} parameters. The @var{keyid}
4036 parameter provides the ID of a previously defined secret that contains
4037 the AES-256 decryption key. This key should be 32-bytes long and be
4038 base64 encoded. The @var{iv} parameter provides the random initialization
4039 vector used for encryption of this particular secret and should be a
4040 base64 encrypted string of the 16-byte IV.
4042 The simplest (insecure) usage is to provide the secret inline
4044 @example
4046 # $QEMU -object secret,id=sec0,data=letmein,format=raw
4048 @end example
4050 The simplest secure usage is to provide the secret via a file
4052 # echo -n "letmein" > mypasswd.txt
4053 # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
4055 For greater security, AES-256-CBC should be used. To illustrate usage,
4056 consider the openssl command line tool which can encrypt the data. Note
4057 that when encrypting, the plaintext must be padded to the cipher block
4058 size (32 bytes) using the standard PKCS#5/6 compatible padding algorithm.
4060 First a master key needs to be created in base64 encoding:
4062 @example
4063 # openssl rand -base64 32 > key.b64
4065 @end example
4067 Each secret to be encrypted needs to have a random initialization vector
4068 generated. These do not need to be kept secret
4070 @example
4071 # openssl rand -base64 16 > iv.b64
4073 @end example
4075 The secret to be defined can now be encrypted, in this case we're
4076 telling openssl to base64 encode the result, but it could be left
4079 @example
4082 @end example
4085 and specify that to be used to decrypt the user password. Pass the
4088 @example
4089 # $QEMU \
4093 @end example
4095 @end table
4097 ETEXI
4101 STEXI
4102 @end table
4103 ETEXI