On Fri, Oct 20, 2017 at 15:04:57 +0200, David Hildenbrand wrote: > On 20.10.2017 14:50, Jiri Denemark wrote: > > The thing is libvirt calls query-cpu-model-expansion to check what the > > host CPU is. This 'host-model' CPU is replaced with the probed CPU model > > when a domain starts. The problem described by Marc is that the probed > > CPU model cannot be used universally with all machine types. So starting > > a domain on such host with machine type s390-virtio-ccw-2.10 works, but > > a domain with machine type s390-virtio-ccw-2.9 fails to start with the > > same probed CPU model. > > > > My assumption would be that the CPU model is copied into the XML when > the domain fist starts. This is what the documentation describes. The CPU model is copied into the XML each time the domain starts. > So when upgrading QEMU, the CPU model in the XML is still the same > (z13), even though something different is now reported in the host info > after upgrading QEMU (z14). > > In this case it would continue to work. > > The problem is that the CPU model is not copied into the XML doesn't > remain there, right? It is suddenly replaced with a z14 host model. Even preserving the actual CPU model in the XML from the first start wouldn't solve the issue. You can always create a new domain with s390-virtio-ccw-2.9 machine type even on the upgraded host. Jirka -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
