v4.19.13 snapshot.
diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h
new file mode 100644
index 0000000..dc4cfc8
--- /dev/null
+++ b/arch/x86/include/asm/clocksource.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* x86-specific clocksource additions */
+
+#ifndef _ASM_X86_CLOCKSOURCE_H
+#define _ASM_X86_CLOCKSOURCE_H
+
+#define VCLOCK_NONE 0 /* No vDSO clock available. */
+#define VCLOCK_TSC 1 /* vDSO should use vread_tsc. */
+#define VCLOCK_PVCLOCK 2 /* vDSO should use vread_pvclock. */
+#define VCLOCK_HVCLOCK 3 /* vDSO should use vread_hvclock. */
+#define VCLOCK_MAX 3
+
+struct arch_clocksource_data {
+ int vclock_mode;
+};
+
+#endif /* _ASM_X86_CLOCKSOURCE_H */