* Peter Maydell (peter.mayd...@linaro.org) wrote: > On Wed, 3 Feb 2021 at 10:49, Dr. David Alan Gilbert <dgilb...@redhat.com> > wrote: > > > > * Peter Maydell (peter.mayd...@linaro.org) wrote: > > > On Wed, 3 Feb 2021 at 10:28, Dr. David Alan Gilbert <dgilb...@redhat.com> > > > wrote: > > > > > > > > * Philippe Mathieu-Daudé (phi...@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. > > So downstream testing only?
I thought there used to be some regular avocado testing of upstream but I'm not sure if it's all architectures and I'm not sure if it's still happening; I haven't seen any migration issues from it for a while, which makes me think it isn't. > I think that unless we either (a) start > doing migration-compat testing consistently upstream or (b) RedHat or > some other downstream start testing and reporting compat issues > to us for aarch64 as they do for x86-64, in practice we're just > not going to have working migration compat despite our best > intentions. (None of the issues Aaron raises were deliberate > compat breaks -- they're all "we made a change we didn't think > affected migration but it turns out that it does".) I'd agree; we still hit this too often on x86 as well. Dave > thanks > -- PMM > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
