diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index a7d9091..c8fb043 100644
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -45,6 +45,19 @@
 	atomic64_set(&last_value, 0);
 }
 
+u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src)
+{
+	unsigned version;
+	cycle_t ret;
+	u8 flags;
+
+	do {
+		version = __pvclock_read_cycles(src, &ret, &flags);
+	} while ((src->version & 1) || version != src->version);
+
+	return flags & valid_flags;
+}
+
 cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
 {
 	unsigned version;