qemu-deprecated.texi - qemu - Git at Google

 @node Deprecated features
 @appendix Deprecated features

 In general features are intended to be supported indefinitely once
 introduced into QEMU. In the event that a feature needs to be removed,
 it will be listed in this appendix. The feature will remain functional
 for 2 releases prior to actual removal. Deprecated features may also
 generate warnings on the console when QEMU starts up, or if activated
 via a monitor command, however, this is not a mandatory requirement.

 Prior to the 2.10.0 release there was no official policy on how
 long features would be deprecated prior to their removal, nor
 any documented list of which features were deprecated. Thus
 any features deprecated prior to 2.10.0 will be treated as if
 they were first deprecated in the 2.10.0 release.

 What follows is a list of all features currently marked as
 deprecated.

 @section Build options

 @subsection SDL 1.2

 Previously QEMU has supported building against both SDL 1.2
 and 2.0 series APIs. Support for the SDL 1.2 builds will be
 discontinued, so maintainers should switch to using SDL 2.0,
 which is the default.

 @section System emulator command line arguments

 @subsection -machine enforce-config-section=on|off (since 3.1)

 The @option{enforce-config-section} parameter is replaced by the
 @option{-global migration.send-configuration=@var{on|off}} option.

 @subsection -no-kvm (since 1.3.0)

 The ``-no-kvm'' argument is now a synonym for setting
 ``-machine accel=tcg''.

 @subsection -usbdevice (since 2.10.0)

 The ``-usbdevice DEV'' argument is now a synonym for setting
 the ``-device usb-DEV'' argument instead. The deprecated syntax
 would automatically enable USB support on the machine type.
 If using the new syntax, USB support must be explicitly
 enabled via the ``-machine usb=on'' argument.

 @subsection -fsdev handle (since 2.12.0)

 The ``handle'' fsdev backend does not support symlinks and causes the 9p
 filesystem in the guest to fail a fair amount of tests from the PJD POSIX
 filesystem test suite. Also it requires the CAP_DAC_READ_SEARCH capability,
 which is not the recommended way to run QEMU. This backend should not be
 used and it will be removed with no replacement.

 @subsection -no-frame (since 2.12.0)

 The @code{--no-frame} argument works with SDL 1.2 only. The other user
 interfaces never implemented this in the first place. So this will be
 removed together with SDL 1.2 support.

 @subsection -virtioconsole (since 3.0.0)

 Option @option{-virtioconsole} has been replaced by
 @option{-device virtconsole}.

 @subsection -clock (since 3.0.0)

 The @code{-clock} option is ignored since QEMU version 1.7.0. There is no
 replacement since it is not needed anymore.

 @subsection -enable-hax (since 3.0.0)

 The @option{-enable-hax} option has been replaced by @option{-accel hax}.
 Both options have been introduced in QEMU version 2.9.0.

 @subsection -drive file=json:@{...@{'driver':'file'@}@} (since 3.0)

 The 'file' driver for drives is no longer appropriate for character or host
 devices and will only accept regular files (S_IFREG). The correct driver
 for these file types is 'host_cdrom' or 'host_device' as appropriate.

 @subsection -net ...,name=@var{name} (since 3.1)

 The @option{name} parameter of the @option{-net} option is a synonym
 for the @option{id} parameter, which should now be used instead.

 @subsection -smp (invalid topologies) (since 3.1)

 CPU topology properties should describe whole machine topology including
 possible CPUs.

 However, historically it was possible to start QEMU with an incorrect topology
 where @math{@var{n} <= @var{sockets} * @var{cores} * @var{threads} < @var{maxcpus}},
 which could lead to an incorrect topology enumeration by the guest.
 Support for invalid topologies will be removed, the user must ensure
 topologies described with -smp include all possible cpus, i.e.
   @math{@var{sockets} * @var{cores} * @var{threads} = @var{maxcpus}}.

 @section QEMU Machine Protocol (QMP) commands

 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)

 "autoload" parameter is now ignored. All bitmaps are automatically loaded
 from qcow2 images.

 @subsection query-cpus (since 2.12.0)

 The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.

 @subsection query-cpus-fast "arch" output member (since 3.0.0)

 The ``arch'' output member of the ``query-cpus-fast'' command is
 replaced by the ``target'' output member.

 @section System emulator human monitor commands

 @subsection The hub_id parameter of 'hostfwd_add' / 'hostfwd_remove' (since 3.1)

 The @option{[hub_id name]} parameter tuple of the 'hostfwd_add' and
 'hostfwd_remove' HMP commands has been replaced by @option{netdev_id}.

 @subsection cpu-add (since 3.1)

 Use ``device_add'' for hotplugging vCPUs instead of ``cpu-add''.  See
 documentation of ``query-hotpluggable-cpus'' for additional details.

 @section System emulator devices

 @subsection ivshmem (since 2.6.0)

 The ``ivshmem'' device type is replaced by either the ``ivshmem-plain''
 or ``ivshmem-doorbell`` device types.

 @subsection bluetooth (since 3.1)

 The bluetooth subsystem is unmaintained since many years and likely bitrotten
 quite a bit. It will be removed without replacement unless some users speaks
 up at the @email{qemu-devel@@nongnu.org} mailing list with information about
 their usecases.

 @section System emulator machines

 @subsection pc-0.10 and pc-0.11 (since 3.0)

 These machine types are very old and likely can not be used for live migration
 from old QEMU versions anymore. A newer machine type should be used instead.

 @subsection prep (PowerPC) (since 3.1)

 This machine type uses an unmaintained firmware, broken in lots of ways,
 and unable to start post-2004 operating systems. 40p machine type should be
 used instead.

 @section Device options

 @subsection Block device options

 @subsubsection "backing": "" (since 2.12.0)

 In order to prevent QEMU from automatically opening an image's backing
 chain, use ``"backing": null'' instead.

 @subsubsection rbd keyvalue pair encoded filenames: "" (since 3.1.0)

 Options for ``rbd'' should be specified according to its runtime options,
 like other block drivers.  Legacy parsing of keyvalue pair encoded
 filenames is useful to open images with the old format for backing files;
 These image files should be updated to use the current format.

 Example of legacy encoding:

 @code{json:@{"file.driver":"rbd", "file.filename":"rbd:rbd/name"@}}

 The above, converted to the current supported format:

 @code{json:@{"file.driver":"rbd", "file.pool":"rbd", "file.image":"name"@}}

 @subsection vio-spapr-device device options

 @subsubsection "irq": "" (since 3.0.0)

 The ``irq'' property is obsoleted.
	@node Deprecated features
	@appendix Deprecated features

	In general features are intended to be supported indefinitely once
	introduced into QEMU. In the event that a feature needs to be removed,
	it will be listed in this appendix. The feature will remain functional
	for 2 releases prior to actual removal. Deprecated features may also
	generate warnings on the console when QEMU starts up, or if activated
	via a monitor command, however, this is not a mandatory requirement.

	Prior to the 2.10.0 release there was no official policy on how
	long features would be deprecated prior to their removal, nor
	any documented list of which features were deprecated. Thus
	any features deprecated prior to 2.10.0 will be treated as if
	they were first deprecated in the 2.10.0 release.

	What follows is a list of all features currently marked as
	deprecated.

	@section Build options

	@subsection SDL 1.2

	Previously QEMU has supported building against both SDL 1.2
	and 2.0 series APIs. Support for the SDL 1.2 builds will be
	discontinued, so maintainers should switch to using SDL 2.0,
	which is the default.

	@section System emulator command line arguments

	@subsection -machine enforce-config-section=on\|off (since 3.1)

	The @option{enforce-config-section} parameter is replaced by the
	@option{-global migration.send-configuration=@var{on\|off}} option.

	@subsection -no-kvm (since 1.3.0)

	The ``-no-kvm'' argument is now a synonym for setting
	``-machine accel=tcg''.

	@subsection -usbdevice (since 2.10.0)

	The ``-usbdevice DEV'' argument is now a synonym for setting
	the ``-device usb-DEV'' argument instead. The deprecated syntax
	would automatically enable USB support on the machine type.
	If using the new syntax, USB support must be explicitly
	enabled via the ``-machine usb=on'' argument.

	@subsection -fsdev handle (since 2.12.0)

	The ``handle'' fsdev backend does not support symlinks and causes the 9p
	filesystem in the guest to fail a fair amount of tests from the PJD POSIX
	filesystem test suite. Also it requires the CAP_DAC_READ_SEARCH capability,
	which is not the recommended way to run QEMU. This backend should not be
	used and it will be removed with no replacement.

	@subsection -no-frame (since 2.12.0)

	The @code{--no-frame} argument works with SDL 1.2 only. The other user
	interfaces never implemented this in the first place. So this will be
	removed together with SDL 1.2 support.

	@subsection -virtioconsole (since 3.0.0)

	Option @option{-virtioconsole} has been replaced by
	@option{-device virtconsole}.

	@subsection -clock (since 3.0.0)

	The @code{-clock} option is ignored since QEMU version 1.7.0. There is no
	replacement since it is not needed anymore.

	@subsection -enable-hax (since 3.0.0)

	The @option{-enable-hax} option has been replaced by @option{-accel hax}.
	Both options have been introduced in QEMU version 2.9.0.

	@subsection -drive file=json:@{...@{'driver':'file'@}@} (since 3.0)

	The 'file' driver for drives is no longer appropriate for character or host
	devices and will only accept regular files (S_IFREG). The correct driver
	for these file types is 'host_cdrom' or 'host_device' as appropriate.

	@subsection -net ...,name=@var{name} (since 3.1)

	The @option{name} parameter of the @option{-net} option is a synonym
	for the @option{id} parameter, which should now be used instead.

	@subsection -smp (invalid topologies) (since 3.1)

	CPU topology properties should describe whole machine topology including
	possible CPUs.

	However, historically it was possible to start QEMU with an incorrect topology
	where @math{@var{n} <= @var{sockets} * @var{cores} * @var{threads} < @var{maxcpus}},
	which could lead to an incorrect topology enumeration by the guest.
	Support for invalid topologies will be removed, the user must ensure
	topologies described with -smp include all possible cpus, i.e.
	@math{@var{sockets} * @var{cores} * @var{threads} = @var{maxcpus}}.

	@section QEMU Machine Protocol (QMP) commands

	@subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)

	"autoload" parameter is now ignored. All bitmaps are automatically loaded
	from qcow2 images.

	@subsection query-cpus (since 2.12.0)

	The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.

	@subsection query-cpus-fast "arch" output member (since 3.0.0)

	The ``arch'' output member of the ``query-cpus-fast'' command is
	replaced by the ``target'' output member.

	@section System emulator human monitor commands

	@subsection The hub_id parameter of 'hostfwd_add' / 'hostfwd_remove' (since 3.1)

	The @option{[hub_id name]} parameter tuple of the 'hostfwd_add' and
	'hostfwd_remove' HMP commands has been replaced by @option{netdev_id}.

	@subsection cpu-add (since 3.1)

	Use ``device_add'' for hotplugging vCPUs instead of ``cpu-add''. See
	documentation of ``query-hotpluggable-cpus'' for additional details.

	@section System emulator devices

	@subsection ivshmem (since 2.6.0)

	The ``ivshmem'' device type is replaced by either the ``ivshmem-plain''
	or ``ivshmem-doorbell`` device types.

	@subsection bluetooth (since 3.1)

	The bluetooth subsystem is unmaintained since many years and likely bitrotten
	quite a bit. It will be removed without replacement unless some users speaks
	up at the @email{qemu-devel@@nongnu.org} mailing list with information about
	their usecases.

	@section System emulator machines

	@subsection pc-0.10 and pc-0.11 (since 3.0)

	These machine types are very old and likely can not be used for live migration
	from old QEMU versions anymore. A newer machine type should be used instead.

	@subsection prep (PowerPC) (since 3.1)

	This machine type uses an unmaintained firmware, broken in lots of ways,
	and unable to start post-2004 operating systems. 40p machine type should be
	used instead.

	@section Device options

	@subsection Block device options

	@subsubsection "backing": "" (since 2.12.0)

	In order to prevent QEMU from automatically opening an image's backing
	chain, use ``"backing": null'' instead.

	@subsubsection rbd keyvalue pair encoded filenames: "" (since 3.1.0)

	Options for ``rbd'' should be specified according to its runtime options,
	like other block drivers. Legacy parsing of keyvalue pair encoded
	filenames is useful to open images with the old format for backing files;
	These image files should be updated to use the current format.

	Example of legacy encoding:

	@code{json:@{"file.driver":"rbd", "file.filename":"rbd:rbd/name"@}}

	The above, converted to the current supported format:

	@code{json:@{"file.driver":"rbd", "file.pool":"rbd", "file.image":"name"@}}

	@subsection vio-spapr-device device options

	@subsubsection "irq": "" (since 3.0.0)

	The ``irq'' property is obsoleted.