Terribly sorry for the late reply. I'm out of work for some unexpected issues the last few weeks. > >> > So i think that checking whether EPT _and_ VPID are supported > >> > should be a precondition to enable PCID support for guests. > >> > > >> > >> Should this check be carried out on L0 too? If so, this will add one more > dependency of PCID on VPID, which doesn't exist in the manual. > > > > Actually it is not necessary because L0 cannot access data which is > > EPT-tagged (and you already require EPT). > > > > So it is fine to remove the cpu_has_hypervisor check along with > > vmx_pcid_supported(). > > > > We can hide INVPCID from the nested guest (by not exposing > IA32_EPT_VPID_CAP) but we can't avoid exposing PCID. So we have to be > sure that if a nested guest sets CR4.PCID, it should work fine. > I'll update the patch so that guest hypervisor can also expose PCID to L2 guests if it is supported. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
