[Qemu-devel] Re: Live migration protocol, device features, ABIs and other beasts

[Juan Quintela <quintela@redhat.com>]

"Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Tue, Nov 24, 2009 at 03:21:34PM +0100, Juan Quintela wrote:

> A device already supports load for a range
> of versions between X and Y. We want to support
> saving to a range of versions.
>
> Which versions to use is a separate decision
> which should be taken on run time, not
> at startup time.

Not in the general case.

Think that v8 brings featureX to one device.  If you _know_ that you don't
want to use feature X, startup time is the proper place.  Important
thing is not the savevm format (we can do any change here), what we
really need is that the guest still runs on the destination, and for
that you can't change the hardware too much.

Later, Juan.