On Wed, 28 Feb 2018 11:26:30 +0100 David Hildenbrand <da...@redhat.com> wrote:
> Then I request the following change in KVM: > > If KVM_S390_VM_CPU_FEAT_AP is enabled in KVM, ECA.28 is _always_ set > (not just if an AP device is configured). This especially makes things a > lot easier when it comes to handling hotplugged CPUs and avoiding race > conditions when enabling these bits as mentioned in the KVM series. > > KVM_S390_VM_CPU_FEAT_AP == AP instructions available for the guest > (don't throw an operation exception). > > So this feature then really is guest ABI. The instructions are > available. If there is no device configured, bad luck. Sounds sensible from my POV.
