diff --git a/include/asm-x86/msr-index.h b/include/asm-x86/msr-index.h
index a4944732be04d9fa1a75d66ab5799f8f96be6eda..4045bbe473794126150d89d82a1f664ac90a0124 100644
--- a/include/asm-x86/msr-index.h
+++ b/include/asm-x86/msr-index.h
@@ -63,6 +63,13 @@
 #define MSR_IA32_LASTINTFROMIP		0x000001dd
 #define MSR_IA32_LASTINTTOIP		0x000001de
 
+/* DEBUGCTLMSR bits (others vary by model): */
+#define _DEBUGCTLMSR_LBR	0 /* last branch recording */
+#define _DEBUGCTLMSR_BTF	1 /* single-step on branches */
+
+#define DEBUGCTLMSR_LBR		(1UL << _DEBUGCTLMSR_LBR)
+#define DEBUGCTLMSR_BTF		(1UL << _DEBUGCTLMSR_BTF)
+
 #define MSR_IA32_MC0_CTL		0x00000400
 #define MSR_IA32_MC0_STATUS		0x00000401
 #define MSR_IA32_MC0_ADDR		0x00000402