diff --git a/[refs] b/[refs]
index bee78f22b414..45efa1d0c46b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: cd0608e71e9757f4dae35bcfb4e88f4d1a03a8ab
+refs/heads/master: 1a7bbda5b1ab0e02622761305a32dc38735b90b2
diff --git a/trunk/arch/x86/xen/enlighten.c b/trunk/arch/x86/xen/enlighten.c
index 668bbfee0cce..4466feb4c69b 100644
--- a/trunk/arch/x86/xen/enlighten.c
+++ b/trunk/arch/x86/xen/enlighten.c
@@ -987,7 +987,16 @@ static void xen_write_cr4(unsigned long cr4)
 
 	native_write_cr4(cr4);
 }
-
+#ifdef CONFIG_X86_64
+static inline unsigned long xen_read_cr8(void)
+{
+	return 0;
+}
+static inline void xen_write_cr8(unsigned long val)
+{
+	BUG_ON(val);
+}
+#endif
 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
 {
 	int ret;
@@ -1156,6 +1165,11 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
 	.read_cr4_safe = native_read_cr4_safe,
 	.write_cr4 = xen_write_cr4,
 
+#ifdef CONFIG_X86_64
+	.read_cr8 = xen_read_cr8,
+	.write_cr8 = xen_write_cr8,
+#endif
+
 	.wbinvd = native_wbinvd,
 
 	.read_msr = native_read_msr_safe,