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.

Build options
=============

GTK 2.x
-------

Previously QEMU has supported building against both GTK 2.x and 3.x series APIs. Support for the GTK 2.x builds will be discontinued, so maintainers should switch to using GTK 3.x, which is the default.

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.

System emulator command line arguments
======================================

-no-kvm (since 1.3.0)
---------------------

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

-vnc tls (since 2.5.0)
----------------------

The ``-vnc tls'' argument is now a synonym for setting ``-object tls-creds-anon,id=tls0'' combined with ``-vnc tls-creds=tls0'

-vnc x509 (since 2.5.0)
-----------------------

The ``-vnc x509=/path/to/certs'' argument is now a synonym for setting ``-object tls-creds-x509,dir=/path/to/certs,id=tls0,verify-peer=no'' combined with ``-vnc tls-creds=tls0'

-vnc x509verify (since 2.5.0)
-----------------------------

The ``-vnc x509verify=/path/to/certs'' argument is now a synonym for setting ``-object tls-creds-x509,dir=/path/to/certs,id=tls0,verify-peer=yes'' combined with ``-vnc tls-creds=tls0'

-tftp (since 2.6.0)
-------------------

The ``-tftp /some/dir'' argument is replaced by either ``-netdev user,id=x,tftp=/some/dir '' (for pluggable NICs, accompanied with ``-device ...,netdev=x''), or ``-nic user,tftp=/some/dir'' (for embedded NICs). The new syntax allows different settings to be provided per NIC.

-bootp (since 2.6.0)
--------------------

The ``-bootp /some/file'' argument is replaced by either ``-netdev user,id=x,bootp=/some/file '' (for pluggable NICs, accompanied with ``-device ...,netdev=x''), or ``-nic user,bootp=/some/file'' (for embedded NICs). The new syntax allows different settings to be provided per NIC.

-redir (since 2.6.0)
--------------------

The ``-redir [tcp|udp]:hostport:[guestaddr]:guestport'' argument is replaced by either ``-netdev user,id=x,hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport'' (for pluggable NICs, accompanied with ``-device ...,netdev=x'') or ``-nic user,hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport'' (for embedded NICs). The new syntax allows different settings to be provided per NIC.

-smb (since 2.6.0)
------------------

The ``-smb /some/dir'' argument is replaced by either ``-netdev user,id=x,smb=/some/dir '' (for pluggable NICs, accompanied with ``-device ...,netdev=x''), or ``-nic user,smb=/some/dir'' (for embedded NICs). The new syntax allows different settings to be provided per NIC.

-drive cyls=...,heads=...,secs=...,trans=... (since 2.10.0)
-----------------------------------------------------------

The drive geometry arguments are replaced by the the geometry arguments that can be specified with the ``-device'' parameter.

-drive serial=... (since 2.10.0)
--------------------------------

The drive serial argument is replaced by the the serial argument that can be specified with the ``-device'' parameter.

-drive addr=... (since 2.10.0)
------------------------------

The drive addr argument is replaced by the the addr argument that can be specified with the ``-device'' parameter.

-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.

-nodefconfig (since 2.11.0)
---------------------------

The ``-nodefconfig`` argument is a synonym for ``-no-user-config``.

-balloon (since 2.12.0)
-----------------------

The --balloon virtio argument has been superseded by --device virtio-balloon.

-machine s390-squash-mcss=on|off (since 2.12.0)
-----------------------------------------------

The ``s390-squash-mcss=on`` property has been obsoleted by allowing the cssid to be chosen freely. Instead of squashing subchannels into the default channel subsystem image for guests that do not support multiple channel subsystems, all devices can be put into the default channel subsystem image.

-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.

-no-frame (since 2.12.0)
------------------------

The --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.

-rtc-td-hack (since 2.12.0)
---------------------------

The -rtc-td-hack option has been replaced by -rtc driftfix=slew.

-localtime (since 2.12.0)
-------------------------

The -localtime option has been replaced by -rtc base=localtime.

-startdate (since 2.12.0)
-------------------------

The -startdate option has been replaced by -rtc base=DATE.

-virtioconsole (since 3.0.0)
----------------------------

Option -virtioconsole has been replaced by -device virtconsole.

-clock (since 3.0.0)
--------------------

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

-enable-hax (since 3.0.0)
-------------------------

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

-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.

QEMU Machine Protocol (QMP) commands
====================================

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

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

query-cpus (since 2.12.0)
-------------------------

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

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.

System emulator devices
=======================

ivshmem (since 2.6.0)
---------------------

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

Page size support < 4k for embedded PowerPC CPUs (since 2.12.0)
---------------------------------------------------------------

qemu-system-ppcemb will be removed. qemu-system-ppc (or qemu-system-ppc64) should be used instead. That means that embedded 4xx PowerPC CPUs will not support page sizes < 4096 any longer.

System emulator machines
========================

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.

Device options
==============

Block device options
--------------------

"backing": "" (since 2.12.0)
............................

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

vio-spapr-device device options
-------------------------------

"irq": "" (since 3.0.0)
.......................

The ``irq'' property is obsoleted.