Re: ARM Snapshots Not Backwards-Compatible

[Dr. David Alan Gilbert]

* Peter Maydell (peter.maydell@linaro.org) wrote:
> On Wed, 3 Feb 2021 at 10:28, Dr. David Alan Gilbert <dgilbert@redhat.com> 
> wrote:
> >
> > * Philippe Mathieu-Daudé (philmd@redhat.com) wrote:
> > > Cc'ing migration team and qemu-arm@ list.
> >
> > I'll have to leave the detail of that to the ARM peole; but from a
> > migration point of view I think we do want the 64 bit ARM migrations to
> > be stable now.  Please tie incompatible changes to machine types.
> 
> That is the intention, but because there's no upstream testing
> of migration compat, we never notice if we get it wrong.
> What is x86 doing to keep cross-version migration working ?

I know there used to be some of our team running Avocado tests for
compatibility regularly, I'm not sure of the current status.
It's something we also do regularly around when we do downstream
releases, so we tend to catch them then, although even on x86 that
often turns out to be a bit late.

Avocado can take a separate qemu path for source/destination.

Dave

> thanks
> -- PMM
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK