diff --git a/sys/amd64/include/cpufunc.h b/sys/amd64/include/cpufunc.h
index c81092dfaf7..34ee7739340 100644
--- a/sys/amd64/include/cpufunc.h
+++ b/sys/amd64/include/cpufunc.h
@@ -651,6 +651,38 @@ load_gs(u_short sel)
 }
 #endif
 
+static __inline uint64_t
+rdfsbase(void)
+{
+	uint64_t x;
+
+	__asm __volatile("rdfsbase %0" : "=r" (x));
+	return (x);
+}
+
+static __inline void
+wrfsbase(uint64_t x)
+{
+
+	__asm __volatile("wrfsbase %0" : : "r" (x));
+}
+
+static __inline uint64_t
+rdgsbase(void)
+{
+	uint64_t x;
+
+	__asm __volatile("rdgsbase %0" : "=r" (x));
+	return (x);
+}
+
+static __inline void
+wrgsbase(uint64_t x)
+{
+
+	__asm __volatile("wrgsbase %0" : : "r" (x));
+}
+
 static __inline void
 bare_lgdt(struct region_descriptor *addr)
 {