> >> What may be needed is making sure X86_FEATURE_SME is not set for PV >> guests. > > And that may be something that Xen will need to control through either > CPUID or MSR support for the PV guests. Only on newer versions of Xen. On earlier versions (2-3 years old) leaf 0x80000007 is passed to the guest unchanged. And so is MSR_K8_SYSCFG. -boris