Re: live migration between qemu-kvm 1.0 and 0.15

[Markus Armbruster <armbru@redhat.com>]

Anthony Liguori <anthony@codemonkey.ws> writes:

> So, since we're approaching 1.1, we should really discuss release
> criteria for 1.1 with respect to live migration.  I'd prefer to avoid
> surprises in this release.
>
> My expectation is that migration works from:
>
> qemu-1.0 -M 1.0     =>    qemu-1.1 -M 1.1
> qemu-1.1 -M 1.0     <=    qemu-1.1 -M 1.0
>
> I would expect that migration works from:
>
> qemu-0.15 -M 0.15   =>   qemu-1.1 -M 0.15
>
> I'm okay if this fails gracefully:
>
> qemu-1.1 -M 0.15    <=   qemu-0.15 -M 0.15

Until we have tools to mechanically verify migratability, such
expecations will remain just that: expectations :)

Vmstate describes the migration format (sort of), vmstate is data,
computers can process data, so at least some mechanical verification
should be possible, shouldn't it?  And even something that can only
disprove migratability, but not prove it, could be incredibly useful.