timing_test: Add mov_to_ds test
diff --git a/timing_test.cc b/timing_test.cc
index 852a27c..d54849d 100644
--- a/timing_test.cc
+++ b/timing_test.cc
@@ -161,6 +161,9 @@
 				      : [limit] "=r" (limit)
 				      : [index] "r" (index) : "cc");
 		}
+	} else if (!strcmp(mode, "mov_to_ds")) {
+	        for (size_t i = 0; i < loops; ++i)
+			asm volatile ("mov %0, %%ds" : : "rm" (0));
 	} else if (!strcmp(mode, "sgdt")) {
 		struct {
 			unsigned short limit;