Re: [PATCH] cpu_map: Drop 'mpx' from x86 cpu models

On 2/9/24 11:52, Tim Wiederhake wrote: > The mpx feature was removed from the corresponding qemu cpu models. > With mpx in the libvirt cpu models, libvirt believes the feature > to be implicitly enabled when creating qemu VMs, while in fact it is > disabled. > > This became an issue when commit 94eacd5a5f introduced new vmx-* > features, of which some are dependent on mpx (see "feature_dependencies" > table in qemu target/i386/cpu.c), e.g. vmx-exit-clear-bndcfgs and > vmx-entry-load-bndcfgs. These features cannot be enabled by qemu > without also mpx being enabled, leading to the error message > > error: Failed to create domain from testdomain.xml > error: operation failed: guest CPU doesn't match > specification: missing features: mpx,vmx-exit-clear-bndcfgs, > vmx-entry-load-bndcfgs > > when trying to create a VM with a "host-model" cpu on a host that > does support mpx and the mentioned vmx-* features: > > <domain> > ... > <cpu mode='host-model' check='full' /> > ... > </domain> > > Resolve the issue by removing mpx from libvirt's cpu models as well. Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com&gt;