On Wed, Jan 04, 2023 at 11:55:01AM -0700, Lena Voytek wrote: > Hello, > > On Thu, 2022-12-08 at 11:16 +0100, Kashyap Chamarthy wrote: > > On Wed, Dec 07, 2022 at 10:23:17AM -0700, Lena Voytek wrote: > > > Hello all, > > > > > > Over the past few months there have been a few more reports of > > > users unable > > > to use Openstack Nova on their Icelake CPU. Updating virsh > > > capabilities to > > > properly display that mpx is unavailable fixes it. Is there an > > > ideal way to > > > update this change such that it gets accepted into libvirt? > > > > I'm just curious if you tried deploying instances by explicitly > > disbaling the "mpx" flag on the compute nodes: > > > > > > cpu_mode = custom > > cpu_models = Icelake-Server > > cpu_model_extra_flags = -mpx > > > > Unfortunately this does not work for Openstack Nova users because virsh > detects the processor as Broadwell-noTSX-IBRS rather than Icelake- > Server. It depends on virsh to provide the correct processor > information to assert that the guest is compatible with the host - > https://github.com/openstack/nova/blob/8a476061c5e034016668cd9e5a20c4430ef6b68d/nova/virt/libvirt/driver.py#L987 That nova code is incorrect. It is comparing a host CPU to a guest CPUI. Nova needs to use the new CPU APIs, to validate whether the configured guest CPU is compatible with KVM guests. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|