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.