[libvirt] [Qemu-devel] [PATCH v4] Add machine parameter qemu-kvm-migration for live migrate compatibility with qemu-kvm

[Alex Bligh]

On 5 Oct 2014, at 08:00, Paolo Bonzini <pbonzini at redhat.com> wrote:

> Il 29/09/2014 09:02, Markus Armbruster ha scritto:
>>> If you were just objecting to the fact that pc-1.0 was made to
>>> be an alias of either one or the other at compile time, simply
>>> drop the second patch of the v2 patchset.
> 
> I was objecting to making pc-1.0 special.  There's nothing special in
> pc-1.0, other machine types also had differences between qemu-kvm and
> qemu.  And I do not think that upstream has any reason to make pc-1.0
> special.

OK, so in v5, pc-1.0 is unchanged, and not made special. A new machine
type is added which allows import from something (unfortunately) called
pc-1.0 in something in qemu's past, as well as some distributions.

> So, if Ubuntu is okay with breaking pc-1.0 migration from 14.04-old to
> 14.04-new, the right thing to do is simply that Ubuntu makes its pc-1.0
> machine type the qemu-kvm one.  No new machine types, no aliases, no
> anything.

That would not allow Ubuntu (or Suse - similarly affected I think)
to import pc-1.0 VMs from things actually running pc-1.0, and would
mean that newly created pc-1.0 VMs would be 'wrong', perpetuating
the problem.

-- 
Alex Bligh