KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE
if (ka->xen.hvm_config.flags & KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE)
KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE |
KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE;
if ((old_flags ^ xhc->flags) & KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE)