2018-07-16 10:32:25 +03:00
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@node Deprecated features
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@appendix Deprecated features
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In general features are intended to be supported indefinitely once
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introduced into QEMU. In the event that a feature needs to be removed,
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it will be listed in this appendix. The feature will remain functional
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for 2 releases prior to actual removal. Deprecated features may also
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generate warnings on the console when QEMU starts up, or if activated
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via a monitor command, however, this is not a mandatory requirement.
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Prior to the 2.10.0 release there was no official policy on how
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long features would be deprecated prior to their removal, nor
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any documented list of which features were deprecated. Thus
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any features deprecated prior to 2.10.0 will be treated as if
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they were first deprecated in the 2.10.0 release.
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What follows is a list of all features currently marked as
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deprecated.
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@section System emulator command line arguments
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2018-09-20 10:22:07 +03:00
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@subsection -machine enforce-config-section=on|off (since 3.1)
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The @option{enforce-config-section} parameter is replaced by the
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@option{-global migration.send-configuration=@var{on|off}} option.
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2018-07-16 10:32:25 +03:00
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@subsection -no-kvm (since 1.3.0)
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2019-09-04 08:27:39 +03:00
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The ``-no-kvm'' argument is now a synonym for setting ``-accel tcg''.
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2018-07-16 10:32:25 +03:00
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@subsection -usbdevice (since 2.10.0)
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The ``-usbdevice DEV'' argument is now a synonym for setting
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the ``-device usb-DEV'' argument instead. The deprecated syntax
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would automatically enable USB support on the machine type.
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If using the new syntax, USB support must be explicitly
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enabled via the ``-machine usb=on'' argument.
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@subsection -drive file=json:@{...@{'driver':'file'@}@} (since 3.0)
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The 'file' driver for drives is no longer appropriate for character or host
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devices and will only accept regular files (S_IFREG). The correct driver
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for these file types is 'host_cdrom' or 'host_device' as appropriate.
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net: Deprecate the "name" parameter of -net
In early times, network backends were specified by a "vlan" and "name"
tuple. With the introduction of netdevs, the "name" was replaced by an
"id" (which is supposed to be unique), but the "name" parameter stayed
as an alias which could be used instead of "id". Unfortunately, we miss
the duplication check for "name":
$ qemu-system-x86_64 -net user,name=n1 -net user,name=n1
... starts without an error, while "id" correctly complains:
$ qemu-system-x86_64 -net user,id=n1 -net user,id=n1
qemu-system-x86_64: -net user,id=n1: Duplicate ID 'n1' for net
Instead of trying to fix the code for the legacy "name" parameter, let's
rather get rid of this old interface and deprecate the "name" parameter
now - this will also be less confusing for the users in the long run.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2018-09-20 11:14:08 +03:00
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@subsection -net ...,name=@var{name} (since 3.1)
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The @option{name} parameter of the @option{-net} option is a synonym
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for the @option{id} parameter, which should now be used instead.
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2018-09-13 14:06:01 +03:00
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@subsection -smp (invalid topologies) (since 3.1)
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CPU topology properties should describe whole machine topology including
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possible CPUs.
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However, historically it was possible to start QEMU with an incorrect topology
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where @math{@var{n} <= @var{sockets} * @var{cores} * @var{threads} < @var{maxcpus}},
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which could lead to an incorrect topology enumeration by the guest.
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Support for invalid topologies will be removed, the user must ensure
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topologies described with -smp include all possible cpus, i.e.
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@math{@var{sockets} * @var{cores} * @var{threads} = @var{maxcpus}}.
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vnc: allow specifying a custom authorization object name
The VNC server has historically had support for ACLs to check both the
SASL username and the TLS x509 distinguished name. The VNC server was
responsible for creating the initial ACL, and the client app was then
responsible for populating it with rules using the HMP 'acl_add' command.
This is not satisfactory for a variety of reasons. There is no way to
populate the ACLs from the command line, users are forced to use the
HMP. With multiple network services all supporting TLS and ACLs now, it
is desirable to be able to define a single ACL that is referenced by all
services.
To address these limitations, two new options are added to the VNC
server CLI. The 'tls-authz' option takes the ID of a QAuthZ object to
use for checking TLS x509 distinguished names, and the 'sasl-authz'
option takes the ID of another object to use for checking SASL usernames.
In this example, we setup two authorization rules. The first allows any
client with a certificate issued by the 'RedHat' organization in the
'London' locality. The second ACL allows clients with either the
'joe@REDHAT.COM' or 'fred@REDHAT.COM' kerberos usernames. Both checks
must pass for the user to be allowed.
$QEMU -object tls-creds-x509,id=tls0,dir=/home/berrange/qemutls,\
endpoint=server,verify-peer=yes \
-object authz-simple,id=authz0,policy=deny,\
rules.0.match=O=RedHat,,L=London,rules.0.policy=allow \
-object authz-simple,id=authz1,policy=deny,\
rules.0.match=fred@REDHAT.COM,rules.0.policy=allow \
rules.0.match=joe@REDHAT.COM,rules.0.policy=allow \
-vnc 0.0.0.0:1,tls-creds=tls0,tls-authz=authz0,
sasl,sasl-authz=authz1 \
...other QEMU args...
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20190227145755.26556-2-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2019-02-27 17:57:54 +03:00
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@subsection -vnc acl (since 4.0.0)
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The @code{acl} option to the @code{-vnc} argument has been replaced
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by the @code{tls-authz} and @code{sasl-authz} options.
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2019-03-09 01:34:14 +03:00
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@subsection QEMU_AUDIO_ environment variables and -audio-help (since 4.0)
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The ``-audiodev'' argument is now the preferred way to specify audio
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backend settings instead of environment variables. To ease migration to
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the new format, the ``-audiodev-help'' option can be used to convert
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the current values of the environment variables to ``-audiodev'' options.
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2019-08-26 22:59:02 +03:00
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@subsection Creating sound card devices and vnc without audiodev= property (since 4.2)
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When not using the deprecated legacy audio config, each sound card
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should specify an @code{audiodev=} property. Additionally, when using
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vnc, you should specify an @code{audiodev=} propery if you plan to
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transmit audio through the VNC protocol.
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2019-06-13 18:34:05 +03:00
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@subsection -mon ...,control=readline,pretty=on|off (since 4.1)
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The @code{pretty=on|off} switch has no effect for HMP monitors, but is
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silently ignored. Using the switch with HMP monitors will become an
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error in the future.
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2019-04-11 20:53:45 +03:00
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@subsection -realtime (since 4.1)
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The @code{-realtime mlock=on|off} argument has been replaced by the
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@code{-overcommit mem-lock=on|off} argument.
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2019-05-30 11:33:18 +03:00
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@subsection -numa node,mem=@var{size} (since 4.1)
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The parameter @option{mem} of @option{-numa node} is used to assign a part of
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guest RAM to a NUMA node. But when using it, it's impossible to manage specified
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RAM chunk on the host side (like bind it to a host node, setting bind policy, ...),
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so guest end-ups with the fake NUMA configuration with suboptiomal performance.
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However since 2014 there is an alternative way to assign RAM to a NUMA node
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using parameter @option{memdev}, which does the same as @option{mem} and adds
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means to actualy manage node RAM on the host side. Use parameter @option{memdev}
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with @var{memory-backend-ram} backend as an replacement for parameter @option{mem}
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to achieve the same fake NUMA effect or a properly configured
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@var{memory-backend-file} backend to actually benefit from NUMA configuration.
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In future new machine versions will not accept the option but it will still
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work with old machine types. User can check QAPI schema to see if the legacy
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option is supported by looking at MachineInfo::numa-mem-supported property.
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2019-05-30 11:33:19 +03:00
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@subsection -numa node (without memory specified) (since 4.1)
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Splitting RAM by default between NUMA nodes has the same issues as @option{mem}
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parameter described above with the difference that the role of the user plays
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QEMU using implicit generic or board specific splitting rule.
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Use @option{memdev} with @var{memory-backend-ram} backend or @option{mem} (if
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it's supported by used machine type) to define mapping explictly instead.
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2019-07-16 21:47:25 +03:00
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@subsection RISC-V -bios (since 4.1)
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QEMU 4.1 introduced support for the -bios option in QEMU for RISC-V for the
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RISC-V virt machine and sifive_u machine.
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QEMU 4.1 has no changes to the default behaviour to avoid breakages. This
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default will change in a future QEMU release, so please prepare now. All users
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of the virt or sifive_u machine must change their command line usage.
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QEMU 4.1 has three options, please migrate to one of these three:
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1. ``-bios none`` - This is the current default behavior if no -bios option
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is included. QEMU will not automatically load any firmware. It is up
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to the user to load all the images they need.
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2. ``-bios default`` - In a future QEMU release this will become the default
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behaviour if no -bios option is specified. This option will load the
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default OpenSBI firmware automatically. The firmware is included with
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the QEMU release and no user interaction is required. All a user needs
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to do is specify the kernel they want to boot with the -kernel option
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3. ``-bios <file>`` - Tells QEMU to load the specified file as the firmwrae.
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2019-11-13 17:16:44 +03:00
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@subsection -tb-size option (since 5.0)
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QEMU 5.0 introduced an alternative syntax to specify the size of the translation
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block cache, @option{-accel tcg,tb-size=}. The new syntax deprecates the
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previously available @option{-tb-size} option.
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2020-01-31 14:56:03 +03:00
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@subsection -show-cursor option (since 5.0)
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Use @option{-display sdl,show-cursor=on} or
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@option{-display gtk,show-cursor=on} instead.
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2018-07-16 10:32:25 +03:00
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@section QEMU Machine Protocol (QMP) commands
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2019-10-24 14:02:23 +03:00
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@subsection change (since 2.5.0)
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Use ``blockdev-change-medium'' or ``change-vnc-password'' instead.
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@subsection migrate_set_downtime and migrate_set_speed (since 2.8.0)
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Use ``migrate-set-parameters'' instead.
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@subsection migrate-set-cache-size and query-migrate-cache-size (since 2.11.0)
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Use ``migrate-set-parameters'' and ``query-migrate-parameters'' instead.
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2019-03-12 19:05:48 +03:00
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@subsection query-block result field dirty-bitmaps[i].status (since 4.0)
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The ``status'' field of the ``BlockDirtyInfo'' structure, returned by
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the query-block command is deprecated. Two new boolean fields,
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``recording'' and ``busy'' effectively replace it.
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2019-07-29 23:35:56 +03:00
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@subsection query-block result field dirty-bitmaps (Since 4.2)
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The ``dirty-bitmaps`` field of the ``BlockInfo`` structure, returned by
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the query-block command is itself now deprecated. The ``dirty-bitmaps``
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field of the ``BlockDeviceInfo`` struct should be used instead, which is the
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type of the ``inserted`` field in query-block replies, as well as the
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type of array items in query-named-block-nodes.
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Since the ``dirty-bitmaps`` field is optionally present in both the old and
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new locations, clients must use introspection to learn where to anticipate
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the field if/when it does appear in command output.
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2018-07-16 10:32:25 +03:00
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@subsection query-cpus (since 2.12.0)
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The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.
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@subsection query-cpus-fast "arch" output member (since 3.0.0)
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The ``arch'' output member of the ``query-cpus-fast'' command is
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replaced by the ``target'' output member.
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2018-12-13 15:42:24 +03:00
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@subsection cpu-add (since 4.0)
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Use ``device_add'' for hotplugging vCPUs instead of ``cpu-add''. See
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documentation of ``query-hotpluggable-cpus'' for additional
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details.
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2019-02-14 18:22:50 +03:00
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@subsection query-events (since 4.0)
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The ``query-events'' command has been superseded by the more powerful
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and accurate ``query-qmp-schema'' command.
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2019-04-15 19:33:36 +03:00
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@subsection chardev client socket with 'wait' option (since 4.0)
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Character devices creating sockets in client mode should not specify
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the 'wait' field, which is only applicable to sockets in server mode
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2018-12-13 15:42:22 +03:00
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@section Human Monitor Protocol (HMP) commands
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2018-09-20 11:22:27 +03:00
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@subsection The hub_id parameter of 'hostfwd_add' / 'hostfwd_remove' (since 3.1)
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The @option{[hub_id name]} parameter tuple of the 'hostfwd_add' and
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'hostfwd_remove' HMP commands has been replaced by @option{netdev_id}.
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2018-12-13 15:42:23 +03:00
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@subsection cpu-add (since 4.0)
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2018-10-30 15:35:24 +03:00
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Use ``device_add'' for hotplugging vCPUs instead of ``cpu-add''. See
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documentation of ``query-hotpluggable-cpus'' for additional details.
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2019-02-27 17:57:55 +03:00
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@subsection acl_show, acl_reset, acl_policy, acl_add, acl_remove (since 4.0.0)
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The ``acl_show'', ``acl_reset'', ``acl_policy'', ``acl_add'', and
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``acl_remove'' commands are deprecated with no replacement. Authorization
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for VNC should be performed using the pluggable QAuthZ objects.
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2019-06-18 04:31:13 +03:00
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@section Guest Emulator ISAs
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@subsection RISC-V ISA privledge specification version 1.09.1 (since 4.1)
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The RISC-V ISA privledge specification version 1.09.1 has been deprecated.
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QEMU supports both the newer version 1.10.0 and the ratified version 1.11.0, these
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should be used instead of the 1.09.1 version.
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2019-04-20 05:24:09 +03:00
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@section System emulator CPUS
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@subsection RISC-V ISA CPUs (since 4.1)
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The RISC-V cpus with the ISA version in the CPU name have been depcreated. The
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four CPUs are: ``rv32gcsu-v1.9.1``, ``rv32gcsu-v1.10.0``, ``rv64gcsu-v1.9.1`` and
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``rv64gcsu-v1.10.0``. Instead the version can be specified via the CPU ``priv_spec``
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option when using the ``rv32`` or ``rv64`` CPUs.
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2019-04-20 05:24:18 +03:00
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@subsection RISC-V ISA CPUs (since 4.1)
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The RISC-V no MMU cpus have been depcreated. The two CPUs: ``rv32imacu-nommu`` and
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``rv64imacu-nommu`` should no longer be used. Instead the MMU status can be specified
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via the CPU ``mmu`` option when using the ``rv32`` or ``rv64`` CPUs.
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2019-04-20 05:24:09 +03:00
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2018-07-16 10:32:25 +03:00
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@section System emulator devices
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2019-10-10 01:43:03 +03:00
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@subsection ide-drive (since 4.2)
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The 'ide-drive' device is deprecated. Users should use 'ide-hd' or
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'ide-cd' as appropriate to get an IDE hard disk or CD-ROM as needed.
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2019-11-01 16:32:20 +03:00
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@subsection scsi-disk (since 4.2)
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The 'scsi-disk' device is deprecated. Users should use 'scsi-hd' or
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'scsi-cd' as appropriate to get a SCSI hard disk or CD-ROM as needed.
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2018-07-16 10:32:25 +03:00
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@section System emulator machines
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2020-01-24 19:38:43 +03:00
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@subsection mips r4k platform (since 5.0)
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2019-11-25 13:41:03 +03:00
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This machine type is very old and unmaintained. Users should use the 'malta'
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machine type instead.
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2019-12-09 15:52:45 +03:00
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@subsection pc-1.0, pc-1.1, pc-1.2 and pc-1.3 (since 5.0)
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2018-07-16 10:32:25 +03:00
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These machine types are very old and likely can not be used for live migration
|
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|
from old QEMU versions anymore. A newer machine type should be used instead.
|
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|
|
2019-04-20 05:24:26 +03:00
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|
|
@subsection spike_v1.9.1 and spike_v1.10 (since 4.1)
|
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|
|
The version specific Spike machines have been deprecated in favour of the
|
|
|
|
generic ``spike`` machine. If you need to specify an older version of the RISC-V
|
|
|
|
spec you can use the ``-cpu rv64gcsu,priv_spec=v1.9.1`` command line argument.
|
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|
|
2018-07-16 10:32:25 +03:00
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|
|
@section Device options
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|
2019-12-13 17:46:26 +03:00
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|
@subsection Emulated device options
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|
@subsubsection -device virtio-blk,scsi=on|off (since 5.0.0)
|
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|
The virtio-blk SCSI passthrough feature is a legacy VIRTIO feature. VIRTIO 1.0
|
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|
and later do not support it because the virtio-scsi device was introduced for
|
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|
|
full SCSI support. Use virtio-scsi instead when SCSI passthrough is required.
|
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|
Note this also applies to ``-device virtio-blk-pci,scsi=on|off'', which is an
|
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|
alias.
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|
2018-07-16 10:32:25 +03:00
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|
|
@subsection Block device options
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|
@subsubsection "backing": "" (since 2.12.0)
|
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|
In order to prevent QEMU from automatically opening an image's backing
|
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|
|
chain, use ``"backing": null'' instead.
|
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|
|
2018-09-12 01:32:33 +03:00
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|
|
@subsubsection rbd keyvalue pair encoded filenames: "" (since 3.1.0)
|
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|
Options for ``rbd'' should be specified according to its runtime options,
|
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|
|
like other block drivers. Legacy parsing of keyvalue pair encoded
|
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|
|
filenames is useful to open images with the old format for backing files;
|
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|
|
These image files should be updated to use the current format.
|
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|
|
|
|
|
|
Example of legacy encoding:
|
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|
|
@code{json:@{"file.driver":"rbd", "file.filename":"rbd:rbd/name"@}}
|
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|
|
|
|
|
|
The above, converted to the current supported format:
|
|
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|
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|
|
@code{json:@{"file.driver":"rbd", "file.pool":"rbd", "file.image":"name"@}}
|
qemu-nbd: Deprecate qemu-nbd --partition
The existing qemu-nbd --partition code claims to handle logical
partitions up to 8, since its introduction in 2008 (commit 7a5ca86).
However, the implementation is bogus (actual MBR logical partitions
form a sort of linked list, with one partition per extended table
entry, rather than four logical partitions in a single extended
table), making the code unlikely to work for anything beyond -P5 on
actual guest images. What's more, the code does not support GPT
partitions, which are becoming more popular, and maintaining device
subsetting in both NBD and the raw device is unnecessary duplication
of effort (even if it is not too difficult).
Note that obtaining the offsets of a partition (MBR or GPT) can be
learned by using 'qemu-nbd -c /dev/nbd0 file.qcow2 && sfdisk --dump
/dev/nbd0', but by the time you've done that, you might as well
just mount /dev/nbd0p1 that the kernel creates for you instead of
bothering with qemu exporting a subset. Or, keeping to just
user-space code, use nbdkit's partition filter, which has already
known both GPT and primary MBR partitions for a while, and was
just recently enhanced to support arbitrary logical MBR parititions.
Start the clock on the deprecation cycle, with examples of how
to accomplish device subsetting without using -P.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190125234837.2272-1-eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2019-01-26 02:48:37 +03:00
|
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|
|
|
|
@section Related binaries
|
|
|
|
|
2019-08-09 12:09:21 +03:00
|
|
|
@subsection qemu-img convert -n -o (since 4.2.0)
|
|
|
|
|
|
|
|
All options specified in @option{-o} are image creation options, so
|
|
|
|
they have no effect when used with @option{-n} to skip image creation.
|
|
|
|
Silently ignored options can be confusing, so this combination of
|
|
|
|
options will be made an error in future versions.
|
|
|
|
|
2019-06-28 03:28:43 +03:00
|
|
|
@section Backwards compatibility
|
|
|
|
|
|
|
|
@subsection Runnability guarantee of CPU models (since 4.1.0)
|
|
|
|
|
|
|
|
Previous versions of QEMU never changed existing CPU models in
|
|
|
|
ways that introduced additional host software or hardware
|
|
|
|
requirements to the VM. This allowed management software to
|
|
|
|
safely change the machine type of an existing VM without
|
|
|
|
introducing new requirements ("runnability guarantee"). This
|
|
|
|
prevented CPU models from being updated to include CPU
|
|
|
|
vulnerability mitigations, leaving guests vulnerable in the
|
|
|
|
default configuration.
|
|
|
|
|
|
|
|
The CPU model runnability guarantee won't apply anymore to
|
|
|
|
existing CPU models. Management software that needs runnability
|
|
|
|
guarantees must resolve the CPU model aliases using te
|
|
|
|
``alias-of'' field returned by the ``query-cpu-definitions'' QMP
|
|
|
|
command.
|
2019-10-03 02:24:11 +03:00
|
|
|
|
i386: Resolve CPU models to v1 by default
When using `query-cpu-definitions` using `-machine none`,
QEMU is resolving all CPU models to their latest versions. The
actual CPU model version being used by another machine type (e.g.
`pc-q35-4.0`) might be different.
In theory, this was OK because the correct CPU model
version is returned when using the correct `-machine` argument.
Except that in practice, this breaks libvirt expectations:
libvirt always use `-machine none` when checking if a CPU model
is runnable, because runnability is not expected to be affected
when the machine type is changed.
For example, when running on a Haswell host without TSX,
Haswell-v4 is runnable, but Haswell-v1 is not. On those hosts,
`query-cpu-definitions` says Haswell is runnable if using
`-machine none`, but Haswell is actually not runnable using any
of the `pc-*` machine types (because they resolve Haswell to
Haswell-v1). In other words, we're breaking the "runnability
guarantee" we promised to not break for a few releases (see
qemu-deprecated.texi).
To address this issue, change the default CPU model version to v1
on all machine types, so we make `query-cpu-definitions` output
when using `-machine none` match the results when using `pc-*`.
This will change in the future (the plan is to always return the
latest CPU model version if using `-machine none`), but only
after giving libvirt the opportunity to adapt.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1779078
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20191205223339.764534-1-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2019-12-06 01:33:39 +03:00
|
|
|
While those guarantees are kept, the return value of
|
|
|
|
``query-cpu-definitions'' will have existing CPU model aliases
|
|
|
|
point to a version that doesn't break runnability guarantees
|
|
|
|
(specifically, version 1 of those CPU models). In future QEMU
|
|
|
|
versions, aliases will point to newer CPU model versions
|
|
|
|
depending on the machine type, so management software must
|
|
|
|
resolve CPU model aliases before starting a virtual machine.
|
|
|
|
|
2019-10-03 02:24:11 +03:00
|
|
|
|
|
|
|
@node Recently removed features
|
|
|
|
@appendix Recently removed features
|
|
|
|
|
|
|
|
What follows is a record of recently removed, formerly deprecated
|
|
|
|
features that serves as a record for users who have encountered
|
|
|
|
trouble after a recent upgrade.
|
|
|
|
|
|
|
|
@section QEMU Machine Protocol (QMP) commands
|
|
|
|
|
|
|
|
@subsection block-dirty-bitmap-add "autoload" parameter (since 4.2.0)
|
|
|
|
|
|
|
|
The "autoload" parameter has been ignored since 2.12.0. All bitmaps
|
|
|
|
are automatically loaded from qcow2 images.
|
2020-01-23 19:46:50 +03:00
|
|
|
|
|
|
|
@section Related binaries
|
|
|
|
|
|
|
|
@subsection qemu-nbd --partition (removed in 5.0.0)
|
|
|
|
|
|
|
|
The ``qemu-nbd --partition $digit'' code (also spelled @option{-P})
|
|
|
|
could only handle MBR partitions, and never correctly handled logical
|
|
|
|
partitions beyond partition 5. Exporting a partition can still be
|
|
|
|
done by utilizing the @option{--image-opts} option with a raw blockdev
|
|
|
|
using the @code{offset} and @code{size} parameters layered on top of
|
|
|
|
any other existing blockdev. For example, if partition 1 is 100MiB
|
|
|
|
long starting at 1MiB, the old command:
|
|
|
|
|
|
|
|
@code{qemu-nbd -t -P 1 -f qcow2 file.qcow2}
|
|
|
|
|
|
|
|
can be rewritten as:
|
|
|
|
|
|
|
|
@code{qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.file.driver=file,file.file.filename=file.qcow2}
|