diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0c0941d..56e45a2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -779,6 +779,7 @@
 #define HF_VINTR_MASK		(1 << 2)
 #define HF_NMI_MASK		(1 << 3)
 #define HF_IRET_MASK		(1 << 4)
+#define HF_GUEST_MASK		(1 << 5) /* VCPU is in guest-mode */
 
 /*
  * Hardware virtualization extension instructions may fault if a