On Thu, 2019-10-03 at 16:00 +0200, Jiri Denemark wrote:
When starting a domain without a CPU model specified in the domain XML, QEMU will choose a default one. Which is fine unless the domain gets migrated to another host because libvirt doesn't perform any CPU ABI checks and the virtual CPU provided by QEMU on the destination host can differ from the one on the source host.
With QEMU 4.2.0 we can probe for the default CPU model used by QEMU for a particular machine type and store it in the domain XML. This way the chosen CPU model is more visible to users and libvirt will make sure the guest will see the exact same CPU after migration.
https://bugzilla.redhat.com/show_bug.cgi?id=1598151 https://bugzilla.redhat.com/show_bug.cgi?id=1598162
Also, this is definitely a user-visible change significant enough to be documented in the release notes, so please provide a patch that does so :) -- Andrea Bolognani / Red Hat / Virtualization