Re: [libvirt] [Qemu-devel] Modern CPU models cannot be used with libvirt

On 03/11/2012 04:12 PM, Anthony Liguori wrote: > This discussion isn't about whether QEMU should have a Westmere > processor definition. In fact, I think I already applied that patch. > It's a discussion about how we handle this up and down the stack. > The question is who should define and manage CPU compatibility. Right > now QEMU does to a certain degree, libvirt discards this and does it's > own thing, and VDSM/ovirt-engine assume that we're providing something > and has built a UI around it. > What I'm proposing we consider: have VDSM manage CPU definitions in > order to provide a specific user experience in ovirt-engine. > We would continue to have Westmere/etc in QEMU exposed as part of the > user configuration. But I don't think it makes a lot of sense to have > to modify QEMU any time a new CPU comes out. We have to. New features often come with new MSRs which need to be live migrated, and of course the cpu flags as well. We may push all these to qemu data files, but this is still qemu. We can't let a management tool decide that cpu feature X is safe to use on qemu version Y.