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
" 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"
"-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.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}][,...]]
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
@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
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
-@value{qemu_system} [...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:)
@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)
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,
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