You can open an image using pre-opened file descriptors from an fd set:
@example
-qemu-system-i386
--add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
--add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
--drive file=/dev/fdset/2,index=0,media=disk
+@value{qemu_system} \
+ -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \
+ -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \
+ -drive file=/dev/fdset/2,index=0,media=disk
@end example
ETEXI
Set default value of @var{driver}'s property @var{prop} to @var{value}, e.g.:
@example
-qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img
+@value{qemu_system_x86} -global ide-hd.physical_block_size=4096 disk-image.img
@end example
In particular, you can use this to set driver properties for devices which are
the recommended is 320x240, 640x480, 800x640.
A timeout could be passed to bios, guest will pause for @var{rb_timeout} ms
-when boot failed, then reboot. If @var{rb_timeout} is '-1', guest will not
-reboot, qemu passes '-1' to bios by default. Currently Seabios for X86
+when boot failed, then reboot. If @option{reboot-timeout} is not set,
+guest will not reboot by default. Currently Seabios for X86
system support it.
Do strict boot via @option{strict=on} as far as firmware/BIOS
@example
# try to boot from network first, then from hard disk
-qemu-system-i386 -boot order=nc
+@value{qemu_system_x86} -boot order=nc
# boot from CD-ROM first, switch back to default order after reboot
-qemu-system-i386 -boot once=d
+@value{qemu_system_x86} -boot once=d
# boot with a splash picture for 5 seconds.
-qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000
+@value{qemu_system_x86} -boot menu=on,splash=/root/boot.bmp,splash-time=5000
@end example
Note: The legacy format '-boot @var{drives}' is still supported but its
memory the guest can reach to 4GB:
@example
-qemu-system-x86_64 -m 1G,slots=3,maxmem=4G
+@value{qemu_system} -m 1G,slots=3,maxmem=4G
@end example
If @var{slots} and @var{maxmem} are not specified, memory hotplug won't
" specifies the audio backend to use\n"
" id= identifier of the backend\n"
" timer-period= timer period in microseconds\n"
+ " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n"
" in|out.fixed-settings= use fixed settings for host audio\n"
" in|out.frequency= frequency to use with fixed settings\n"
" in|out.channels= number of channels to use with fixed settings\n"
" in|out.format= sample format to use with fixed settings\n"
" valid values: s8, s16, s32, u8, u16, u32\n"
" in|out.voices= number of voices to use\n"
- " in|out.buffer-len= length of buffer in microseconds\n"
+ " in|out.buffer-length= length of buffer in microseconds\n"
"-audiodev none,id=id,[,prop[=value][,...]]\n"
" dummy driver that discards all output\n"
#ifdef CONFIG_AUDIO_ALSA
"-audiodev alsa,id=id[,prop[=value][,...]]\n"
" in|out.dev= name of the audio device to use\n"
- " in|out.period-len= length of period in microseconds\n"
+ " in|out.period-length= length of period in microseconds\n"
" in|out.try-poll= attempt to use poll mode\n"
" threshold= threshold (in microseconds) when playback starts\n"
#endif
"-audiodev pa,id=id[,prop[=value][,...]]\n"
" server= PulseAudio server address\n"
" in|out.name= source/sink device name\n"
+ " in|out.latency= desired latency in microseconds\n"
#endif
#ifdef CONFIG_AUDIO_SDL
"-audiodev sdl,id=id[,prop[=value][,...]]\n"
-audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified
@end example
+NOTE: parameter validation is known to be incomplete, in many cases
+specifying an invalid option causes QEMU to print an error message and
+continue emulation without sound.
+
Valid global options are:
@table @option
Sets the timer @var{period} used by the audio subsystem in microseconds.
Default is 10000 (10 ms).
+@item in|out.mixing-engine=on|off
+Use QEMU's mixing engine to mix all streams inside QEMU and convert
+audio formats when not supported by the backend. When off,
+@var{fixed-settings} must be off too. Note that disabling this option
+means that the selected backend must support multiple streams and the
+audio formats used by the virtual cards, otherwise you'll get no sound.
+It's not recommended to disable this option unless you want to use 5.1
+or 7.1 audio, as mixing engine only supports mono and stereo audio.
+Default is on.
+
@item in|out.fixed-settings=on|off
Use fixed settings for host audio. When off, it will change based on
how the guest opens the sound card. In this case you must not specify
@item in|out.voices=@var{voices}
Specify the number of @var{voices} to use. Default is 1.
-@item in|out.buffer=@var{usecs}
+@item in|out.buffer-length=@var{usecs}
Sets the size of the buffer in microseconds.
@end table
Specify the ALSA @var{device} to use for input and/or output. Default
is @code{default}.
-@item in|out.period-len=@var{usecs}
+@item in|out.period-length=@var{usecs}
Sets the period length in microseconds.
@item in|out.try-poll=on|off
@item in|out.name=@var{sink}
Use the specified source/sink for recording/playback.
+@item in|out.latency=@var{usecs}
+Desired latency in microseconds. The PulseAudio server will try to honor this
+value but actual latencies may be lower or higher.
+
@end table
@item -audiodev sdl,id=@var{id}[,@var{prop}[=@var{value}][,...]]
@item -soundhw @var{card1}[,@var{card2},...] or -soundhw all
@findex -soundhw
Enable audio and selected sound hardware. Use 'help' to print all
-available sound hardware.
+available sound hardware. For example:
@example
-qemu-system-i386 -soundhw sb16,adlib disk.img
-qemu-system-i386 -soundhw es1370 disk.img
-qemu-system-i386 -soundhw ac97 disk.img
-qemu-system-i386 -soundhw hda disk.img
-qemu-system-i386 -soundhw all disk.img
-qemu-system-i386 -soundhw help
+@value{qemu_system_x86} -soundhw sb16,adlib disk.img
+@value{qemu_system_x86} -soundhw es1370 disk.img
+@value{qemu_system_x86} -soundhw ac97 disk.img
+@value{qemu_system_x86} -soundhw hda disk.img
+@value{qemu_system_x86} -soundhw all disk.img
+@value{qemu_system_x86} -soundhw help
@end example
Note that Linux's i810_audio OSS kernel (for AC97) module might
@code{-device @var{driver},help}.
Some drivers are:
-@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
+@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}]
Add an IPMI BMC. This is a simulation of a hardware management
interface processor that normally sits on a system. It provides
it.
@table @option
-@item bmc=@var{id}
-The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
+@item id=@var{id}
+The BMC id for interfaces to use this device.
@item slave_addr=@var{val}
Define slave address to use for the BMC. The default is 0x20.
@item sdrfile=@var{file}
size of a Field Replaceable Unit (FRU) area. The default is 1024.
@item frudatafile=@var{file}
file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
+@item guid=@var{uuid}
+value for the GUID for the BMC, in standard UUID format. If this is set,
+get "Get GUID" command to the BMC will return it. Otherwise "Get GUID"
+will return an error.
@end table
@item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]
DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
"-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
" [,cache.direct=on|off][,cache.no-flush=on|off]\n"
- " [,read-only=on|off][,detect-zeroes=on|off|unmap]\n"
+ " [,read-only=on|off][,auto-read-only=on|off]\n"
+ " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n"
" [,driver specific parameters...]\n"
" configure a block backend\n", QEMU_ARCH_ALL)
STEXI
For the top level, an explicit node name must be specified.
@item read-only
Open the node read-only. Guest write attempts will fail.
+
+Note that some block drivers support only read-only access, either generally or
+in certain configurations. In this case, the default value
+@option{read-only=off} does not work and the option must be specified
+explicitly.
+@item auto-read-only
+If @option{auto-read-only=on} is set, QEMU may fall back to read-only usage
+even when @option{read-only=off} is requested, or even switch between modes as
+needed, e.g. depending on whether the image file is writable or whether a
+writing user is attached to the node.
+@item force-share
+Override the image locking system of QEMU by forcing the node to utilize
+weaker shared access for permissions where it would normally request exclusive
+access. When there is the potential for multiple instances to have the same
+file open (whether this invocation of QEMU is the first or the second
+instance), both instances must permit shared access for the second instance to
+succeed at opening the file.
+
+Enabling @option{force-share=on} requires @option{read-only=on}.
@item cache.direct
The host page cache can be avoided with @option{cache.direct=on}. This will
attempt to do disk IO directly to the guest's memory. QEMU may still perform an
Instead of @option{-cdrom} you can use:
@example
-qemu-system-i386 -drive file=file,index=2,media=cdrom
+@value{qemu_system} -drive file=file,index=2,media=cdrom
@end example
Instead of @option{-hda}, @option{-hdb}, @option{-hdc}, @option{-hdd}, you can
use:
@example
-qemu-system-i386 -drive file=file,index=0,media=disk
-qemu-system-i386 -drive file=file,index=1,media=disk
-qemu-system-i386 -drive file=file,index=2,media=disk
-qemu-system-i386 -drive file=file,index=3,media=disk
+@value{qemu_system} -drive file=file,index=0,media=disk
+@value{qemu_system} -drive file=file,index=1,media=disk
+@value{qemu_system} -drive file=file,index=2,media=disk
+@value{qemu_system} -drive file=file,index=3,media=disk
@end example
You can open an image using pre-opened file descriptors from an fd set:
@example
-qemu-system-i386
--add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
--add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
--drive file=/dev/fdset/2,index=0,media=disk
+@value{qemu_system} \
+ -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \
+ -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \
+ -drive file=/dev/fdset/2,index=0,media=disk
@end example
You can connect a CDROM to the slave of ide0:
@example
-qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom
+@value{qemu_system_x86} -drive file=file,if=ide,index=1,media=cdrom
@end example
If you don't specify the "file=" argument, you define an empty drive:
@example
-qemu-system-i386 -drive if=ide,index=1,media=cdrom
+@value{qemu_system_x86} -drive if=ide,index=1,media=cdrom
@end example
Instead of @option{-fda}, @option{-fdb}, you can use:
@example
-qemu-system-i386 -drive file=file,index=0,if=floppy
-qemu-system-i386 -drive file=file,index=1,if=floppy
+@value{qemu_system_x86} -drive file=file,index=0,if=floppy
+@value{qemu_system_x86} -drive file=file,index=1,if=floppy
@end example
By default, @var{interface} is "ide" and @var{index} is automatically
incremented:
@example
-qemu-system-i386 -drive file=a -drive file=b"
+@value{qemu_system_x86} -drive file=a -drive file=b"
@end example
is interpreted like:
@example
-qemu-system-i386 -hda a -hdb b
+@value{qemu_system_x86} -hda a -hdb b
@end example
ETEXI
DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
"-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n"
- " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n"
+ " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n"
"-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n"
"-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n"
"-virtfs synth,mount_tag=tag[,id=id][,readonly]\n",
STEXI
-@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}]
+@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}][,multidevs=@var{multidevs}]
@itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly]
@itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly]
@itemx -virtfs synth,mount_tag=@var{mount_tag}
only with security models "mapped-xattr" and "mapped-file".
@item mount_tag=@var{mount_tag}
Specifies the tag name to be used by the guest to mount this export point.
+@item multidevs=@var{multidevs}
+Specifies how to deal with multiple devices being shared with a 9p export.
+Supported behaviours are either "remap", "forbid" or "warn". The latter is
+the default behaviour on which virtfs 9p expects only one device to be
+shared with the same export, and if more than one device is shared and
+accessed via the same 9p export then only a warning message is logged
+(once) by qemu on host side. In order to avoid file ID collisions on guest
+you should either create a separate virtfs export for each device to be
+shared with guests (recommended way) or you might use "remap" instead which
+allows you to share multiple devices with only one export instead, which is
+achieved by remapping the original inode numbers from host to guest in a
+way that would prevent such collisions. Remapping inodes in such use cases
+is required because the original device IDs from host are never passed and
+exposed on guest. Instead all files of an export shared with virtfs always
+share the same device id on guest. So two files with identical inode
+numbers but from actually different devices on host would otherwise cause a
+file ID collision and hence potential misbehaviours on guest. "forbid" on
+the other hand assumes like "warn" that only one device is shared by the
+same export, however it will not only log a warning message but also
+deny access to additional devices on guest. Note though that "forbid" does
+currently not block all possible file access operations (e.g. readdir()
+would still return entries from other devices).
@end table
ETEXI
-DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
- "-virtfs_synth Create synthetic file system image\n",
- QEMU_ARCH_ALL)
-STEXI
-@item -virtfs_synth
-@findex -virtfs_synth
-Create synthetic file system image. Note that this option is now deprecated.
-Please use @code{-fsdev synth} and @code{-device virtio-9p-...} instead.
-ETEXI
-
DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
"-iscsi [user=user][,password=password]\n"
" [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
ETEXI
DEF("display", HAS_ARG, QEMU_OPTION_display,
+#if defined(CONFIG_SPICE)
"-display spice-app[,gl=on|off]\n"
- "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
+#endif
+#if defined(CONFIG_SDL)
+ "-display sdl[,alt_grab=on|off][,ctrl_grab=on|off]\n"
" [,window_close=on|off][,gl=on|core|es|off]\n"
+#endif
+#if defined(CONFIG_GTK)
"-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
+#endif
+#if defined(CONFIG_VNC)
"-display vnc=<display>[,<optargs>]\n"
+#endif
+#if defined(CONFIG_CURSES)
"-display curses[,charset=<encoding>]\n"
+#endif
+#if defined(CONFIG_OPENGL)
+ "-display egl-headless[,rendernode=<file>]\n"
+#endif
"-display none\n"
- "-display egl-headless[,rendernode=<file>]"
- " select display type\n"
- "The default display is equivalent to\n"
+ " select display backend type\n"
+ " The default display is equivalent to\n "
#if defined(CONFIG_GTK)
- "\t\"-display gtk\"\n"
+ "\"-display gtk\"\n"
#elif defined(CONFIG_SDL)
- "\t\"-display sdl\"\n"
+ "\"-display sdl\"\n"
#elif defined(CONFIG_COCOA)
- "\t\"-display cocoa\"\n"
+ "\"-display cocoa\"\n"
#elif defined(CONFIG_VNC)
- "\t\"-vnc localhost:0,to=99,id=default\"\n"
+ "\"-vnc localhost:0,to=99,id=default\"\n"
#else
- "\t\"-display none\"\n"
+ "\"-display none\"\n"
#endif
, QEMU_ARCH_ALL)
STEXI
DEF("g", 1, QEMU_OPTION_g ,
"-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
- QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
+ QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K)
STEXI
@item -g @var{width}x@var{height}[x@var{depth}]
@findex -g
be used to shorten the command line length (note that the e1000 is the default
on i386, so the @option{model=e1000} parameter could even be omitted here, too):
@example
-qemu-system-i386 -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
-qemu-system-i386 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
+@value{qemu_system} -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
+@value{qemu_system} -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
@end example
@item -nic none
Example:
@example
-qemu-system-i386 -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
+@value{qemu_system} -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
@end example
@item domainname=@var{domain}
Example (using pxelinux):
@example
-qemu-system-i386 -hda linux.img -boot n -device e1000,netdev=n1 \
+@value{qemu_system} -hda linux.img -boot n -device e1000,netdev=n1 \
-netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
@end example
@example
# on the host
-qemu-system-i386 -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
+@value{qemu_system} -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
# this host xterm should open in the guest X11 server
xterm -display :1
@end example
@example
# on the host
-qemu-system-i386 -nic user,hostfwd=tcp::5555-:23
+@value{qemu_system} -nic user,hostfwd=tcp::5555-:23
telnet localhost 5555
@end example
@example
# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
# the guest accesses it
-qemu-system-i386 -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
+@value{qemu_system} -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
@end example
Or you can execute a command on every TCP connection established by the guest,
@example
# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
# and connect the TCP stream to its stdin/stdout
-qemu-system-i386 -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
+@value{qemu_system} -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
@end example
@end table
@example
#launch a QEMU instance with the default network script
-qemu-system-i386 linux.img -nic tap
+@value{qemu_system} linux.img -nic tap
@end example
@example
#launch a QEMU instance with two NICs, each one connected
#to a TAP device
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
-netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
@end example
@example
#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge br0
-qemu-system-i386 linux.img -device virtio-net-pci,netdev=n1 \
+@value{qemu_system} linux.img -device virtio-net-pci,netdev=n1 \
-netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
@end example
@example
#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge br0
-qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
+@value{qemu_system} linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
@end example
@example
#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge qemubr0
-qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
+@value{qemu_system} linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
@end example
@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
Example:
@example
# launch a first QEMU instance
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-device e1000,netdev=n1,mac=52:54:00:12:34:56 \
-netdev socket,id=n1,listen=:1234
# connect the network of this instance to the network of the first instance
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-device e1000,netdev=n2,mac=52:54:00:12:34:57 \
-netdev socket,id=n2,connect=127.0.0.1:1234
@end example
Example:
@example
# launch one QEMU instance
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-device e1000,netdev=n1,mac=52:54:00:12:34:56 \
-netdev socket,id=n1,mcast=230.0.0.1:1234
# launch another QEMU instance on same "bus"
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-device e1000,netdev=n2,mac=52:54:00:12:34:57 \
-netdev socket,id=n2,mcast=230.0.0.1:1234
# launch yet another QEMU instance on same "bus"
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-device e1000,netdev=n3,mac=52:54:00:12:34:58 \
-netdev socket,id=n3,mcast=230.0.0.1:1234
@end example
Example (User Mode Linux compat.):
@example
# launch QEMU instance (note mcast address selected is UML's default)
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-device e1000,netdev=n1,mac=52:54:00:12:34:56 \
-netdev socket,id=n1,mcast=239.192.168.1:1102
# launch UML
Example (send packets from host's 1.2.3.4):
@example
-qemu-system-i386 linux.img \
+@value{qemu_system} linux.img \
-device e1000,netdev=n1,mac=52:54:00:12:34:56 \
-netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
@end example
# on 4.3.2.1
# launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
-qemu-system-i386 linux.img -device e1000,netdev=n1 \
+@value{qemu_system} linux.img -device e1000,netdev=n1 \
-netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
@end example
# launch vde switch
vde_switch -F -sock /tmp/myswitch
# launch QEMU instance
-qemu-system-i386 linux.img -nic vde,sock=/tmp/myswitch
+@value{qemu_system} linux.img -nic vde,sock=/tmp/myswitch
@end example
@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
ETEXI
DEFHEADING()
-DEFHEADING(Bluetooth(R) options:)
-STEXI
-@table @option
-ETEXI
-
-DEF("bt", HAS_ARG, QEMU_OPTION_bt, \
- "-bt hci,null dumb bluetooth HCI - doesn't respond to commands\n" \
- "-bt hci,host[:id]\n" \
- " use host's HCI with the given name\n" \
- "-bt hci[,vlan=n]\n" \
- " emulate a standard HCI in virtual scatternet 'n'\n" \
- "-bt vhci[,vlan=n]\n" \
- " add host computer to virtual scatternet 'n' using VHCI\n" \
- "-bt device:dev[,vlan=n]\n" \
- " emulate a bluetooth device 'dev' in scatternet 'n'\n",
- QEMU_ARCH_ALL)
-STEXI
-@item -bt hci[...]
-@findex -bt
-Defines the function of the corresponding Bluetooth HCI. -bt options
-are matched with the HCIs present in the chosen machine type. For
-example when emulating a machine with only one HCI built into it, only
-the first @code{-bt hci[...]} option is valid and defines the HCI's
-logic. The Transport Layer is decided by the machine type. Currently
-the machines @code{n800} and @code{n810} have one HCI and all other
-machines have none.
-
-Note: This option and the whole bluetooth subsystem is considered as deprecated.
-If you still use it, please send a mail to @email{qemu-devel@@nongnu.org} where
-you describe your usecase.
-
-@anchor{bt-hcis}
-The following three types are recognized:
-
-@table @option
-@item -bt hci,null
-(default) The corresponding Bluetooth HCI assumes no internal logic
-and will not respond to any HCI commands or emit events.
-
-@item -bt hci,host[:@var{id}]
-(@code{bluez} only) The corresponding HCI passes commands / events
-to / from the physical HCI identified by the name @var{id} (default:
-@code{hci0}) on the computer running QEMU. Only available on @code{bluez}
-capable systems like Linux.
-
-@item -bt hci[,vlan=@var{n}]
-Add a virtual, standard HCI that will participate in the Bluetooth
-scatternet @var{n} (default @code{0}). Similarly to @option{-net}
-VLANs, devices inside a bluetooth network @var{n} can only communicate
-with other devices in the same network (scatternet).
-@end table
-
-@item -bt vhci[,vlan=@var{n}]
-(Linux-host only) Create a HCI in scatternet @var{n} (default 0) attached
-to the host bluetooth stack instead of to the emulated target. This
-allows the host and target machines to participate in a common scatternet
-and communicate. Requires the Linux @code{vhci} driver installed. Can
-be used as following:
-
-@example
-qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5
-@end example
-
-@item -bt device:@var{dev}[,vlan=@var{n}]
-Emulate a bluetooth device @var{dev} and place it in network @var{n}
-(default @code{0}). QEMU can only emulate one type of bluetooth devices
-currently:
-
-@table @option
-@item keyboard
-Virtual wireless keyboard implementing the HIDP bluetooth profile.
-@end table
-ETEXI
-
-STEXI
-@end table
-ETEXI
-DEFHEADING()
-
#ifdef CONFIG_TPM
DEFHEADING(TPM device options:)
stdio are reasonable use case. The latter is allowing to start QEMU from
within gdb and establish the connection via a pipe:
@example
-(gdb) target remote | exec qemu-system-i386 -gdb stdio ...
+(gdb) target remote | exec @value{qemu_system} -gdb stdio ...
@end example
ETEXI
@findex -trace
@include qemu-option-trace.texi
ETEXI
+DEF("plugin", HAS_ARG, QEMU_OPTION_plugin,
+ "-plugin [file=]<file>[,arg=<string>]\n"
+ " load a plugin\n",
+ QEMU_ARCH_ALL)
+STEXI
+@item -plugin file=@var{file}[,arg=@var{string}]
+@findex -plugin
+
+Load a plugin.
+
+@table @option
+@item file=@var{file}
+Load the given plugin from a shared library file.
+@item arg=@var{string}
+Argument string passed to the plugin. (Can be given multiple times.)
+@end table
+ETEXI
HXCOMM Internal use
DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
Enable FIPS 140-2 compliance mode.
ETEXI
-HXCOMM Deprecated by -machine accel=tcg property
+HXCOMM Deprecated by -accel tcg
DEF("no-kvm", 0, QEMU_OPTION_no_kvm, "", QEMU_ARCH_I386)
DEF("msg", HAS_ARG, QEMU_OPTION_msg,
"-msg timestamp[=on|off]\n"
- " change the format of messages\n"
- " on|off controls leading timestamps (default:on)\n",
+ " control error message format\n"
+ " timestamp=on enables timestamps (default: off)\n",
QEMU_ARCH_ALL)
STEXI
@item -msg timestamp[=on|off]
@findex -msg
-prepend a timestamp to each log message.(default:on)
+Control error message format.
+@table @option
+@item timestamp=on|off
+Prefix messages with a timestamp. Default is off.
+@end table
ETEXI
DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
The @option{share} boolean option is @var{on} by default with memfd.
+@item -object rng-builtin,id=@var{id}
+
+Creates a random number generator backend which obtains entropy from
+QEMU builtin functions. The @option{id} parameter is a unique ID that
+will be used to reference this entropy backend from the @option{virtio-rng}
+device. By default, the @option{virtio-rng} device uses this RNG backend.
+
@item -object rng-random,id=@var{id},filename=@var{/dev/random}
Creates a random number generator backend which obtains entropy from
@example
- # qemu-system-x86_64 \
+ # @value{qemu_system} \
[...] \
-object cryptodev-backend-builtin,id=cryptodev0 \
-device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
@example
- # qemu-system-x86_64 \
+ # @value{qemu_system} \
[...] \
-chardev socket,id=chardev0,path=/path/to/socket \
-object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \
@example
- # $QEMU -object secret,id=sec0,data=letmein,format=raw
+ # @value{qemu_system} -object secret,id=sec0,data=letmein,format=raw
@end example
The simplest secure usage is to provide the secret via a file
# printf "letmein" > mypasswd.txt
- # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw
+ # @value{qemu_system} -object secret,id=sec0,file=mypasswd.txt,format=raw
For greater security, AES-256-CBC should be used. To illustrate usage,
consider the openssl command line tool which can encrypt the data. Note
contents of @code{iv.b64} to the second secret
@example
- # $QEMU \
+ # @value{qemu_system} \
-object secret,id=secmaster0,format=base64,file=key.b64 \
-object secret,id=sec0,keyid=secmaster0,format=base64,\
data=$SECRET,iv=$(<iv.b64)
e.g to launch a SEV guest
@example
- # $QEMU \
+ # @value{qemu_system_x86} \
......
-object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \
-machine ...,memory-encryption=sev0
An example authorization object to validate a x509 distinguished name
would look like:
@example
- # $QEMU \
+ # @value{qemu_system} \
...
-object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \
...
An example authorization object to validate a SASL username
would look like:
@example
- # $QEMU \
+ # @value{qemu_system} \
...
-object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=yes
...
name would look like:
@example
- # $QEMU \
+ # @value{qemu_system} \
...
-object authz-pam,id=auth0,service=qemu-vnc
...
CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
@end example
+@item -object iothread,id=@var{id},poll-max-ns=@var{poll-max-ns},poll-grow=@var{poll-grow},poll-shrink=@var{poll-shrink}
+
+Creates a dedicated event loop thread that devices can be assigned to. This is
+known as an IOThread. By default device emulation happens in vCPU threads or
+the main event loop thread. This can become a scalability bottleneck.
+IOThreads allow device emulation and I/O to run on other host CPUs.
+
+The @option{id} parameter is a unique ID that will be used to reference this
+IOThread from @option{-device ...,iothread=@var{id}}. Multiple devices can be
+assigned to an IOThread. Note that not all devices support an
+@option{iothread} parameter.
+
+The @code{query-iothreads} QMP command lists IOThreads and reports their thread
+IDs so that the user can configure host CPU pinning/affinity.
+
+IOThreads use an adaptive polling algorithm to reduce event loop latency.
+Instead of entering a blocking system call to monitor file descriptors and then
+pay the cost of being woken up when an event occurs, the polling algorithm
+spins waiting for events for a short time. The algorithm's default parameters
+are suitable for many cases but can be adjusted based on knowledge of the
+workload and/or host device latency.
+
+The @option{poll-max-ns} parameter is the maximum number of nanoseconds to busy
+wait for events. Polling can be disabled by setting this value to 0.
+
+The @option{poll-grow} parameter is the multiplier used to increase the polling
+time when the algorithm detects it is missing events due to not polling long
+enough.
+
+The @option{poll-shrink} parameter is the divisor used to decrease the polling
+time when the algorithm detects it is spending too long polling without
+encountering events.
+
+The polling parameters can be modified at run-time using the @code{qom-set} command (where @code{iothread1} is the IOThread's @code{id}):
+
+@example
+(qemu) qom-set /objects/iothread1 poll-max-ns 100000
+@end example
@end table
projects / qemu.git / blobdiff