qemu-options: document existance of versioned machine types

The -machine docs did not explain what the versioned machine
types are for, nor that they'll be maintained across
releases.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <20170725141041.1195-1-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Daniel P. Berrange 2017-07-25 15:10:41 +01:00 committed by Paolo Bonzini
parent 393c13b940
commit 8bfce83a3b

View File

@ -49,7 +49,20 @@ STEXI
@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
@findex -machine
Select the emulated machine by @var{name}. Use @code{-machine help} to list
available machines. Supported machine properties are:
available machines.
For architectures which aim to support live migration compatibility
across releases, each release will introduce a new versioned machine
type. For example, the 2.8.0 release introduced machine types
``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures.
To allow live migration of guests from QEMU version 2.8.0, to QEMU
version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8''
and ``pc-q35-2.8'' machines too. To allow users live migrating VMs
to skip multiple intermediate releases when upgrading, new releases
of QEMU will support machine types from many previous versions.
Supported machine properties are:
@table @option
@item accel=@var{accels1}[:@var{accels2}[:...]]
This is used to enable an accelerator. Depending on the target architecture,