Erik Skultety <eskul...@redhat.com> writes: > On Fri, Aug 16, 2019 at 08:10:20AM +0200, Markus Armbruster wrote: >> Eduardo Habkost <ehabk...@redhat.com> writes: >> >> > We have this issue reported when using libvirt to hotplug CPUs: >> > https://bugzilla.redhat.com/show_bug.cgi?id=1741451 >> > >> > Basically, libvirt is not copying die-id from >> > query-hotpluggable-cpus, but die-id is now mandatory. >> >> Uh-oh, "is now mandatory": making an optional property mandatory is an >> incompatible change. When did we do that? Commit hash, please. >> >> [...] >> > > I don't even see it as being optional ever - the property wasn't even > recognized before commit 176d2cda0de introduced it as mandatory.
Compatibility break. Commit 176d2cda0de is in v4.1.0. If I had learned about it a bit earlier, I would've argued for a last minute fix or a revert. Now we have a regression in the release. Eduardo, I think this fix should go into v4.1.1. Please add cc: qemu-stable. How can we best avoid such compatibility breaks to slip in undetected? A static checker would be nice. For vmstate, we have scripts/vmstate-static-checker.py. Not sure it's used.
