Re: [Qemu-devel] KVM call minutes for Feb 15

[Amit Shah]

On (Tue) 15 Feb 2011 [17:13:13], Anthony Liguori wrote:
> On 02/15/2011 10:26 AM, Chris Wright wrote:
> >
> >revisit new ->  old migration
> >- Amit offers virtio-serial patches and some legwork
> 
> So, to me, migration correctness trumps compatibility.  I don't
> think compatibility is useful if it means that a guest may fail
> during migration.  We have subsections as a way to support the cases
> where it's safe to migrate to an old version only if a feature is
> not being used or a corner case is not currently happening.  This is
> the best way to approach the problem.
> 
> If a subsection won't work, that means you want to migrate when
> you're completely sure that migrating will break a guest.  That
> doesn't seem reasonable at all to me.
> 
> I think in the last discussion on Amit's patches, I had suggested
> that subsections could be used to allow migration when there wasn't
> any queued data.  I think this is the best we can do while
> preserving correctness.

The only problem is that virtio hasn't been converted over to vmstate,
which is necessary for subsections.

                Amit