On 19/07/2017 13:56, Thomas Huth wrote: > +@node Machine types > +@section Machine types > + > +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 a guest running on a 2.8.0 release to a > +2.9.0, the QEMU 2.9.0 version must support the ``pc-i440fx-2.8'' and > +``pc-q35-2.8''. 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. > + > +The supported lifetime for versioned machine types is 12 releases, > +which is equivalent to 4 years worth of previous QEMU releases.
I think there's still no consensus on this. The first two paragraphs should be added to the documentation for -machine in qemu-options.hx, since "-machine [type=]foo" is currently not documented at all. Paolo
