diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 256c0fc92b67b858417fa00e3d3e1fe5ae0280bc..955d2eeac964db498170f3a780343d3a29240999 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -811,6 +811,9 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_VAPIC:
 		r = !kvm_x86_ops->cpu_has_accelerated_tpr();
 		break;
+	case KVM_CAP_NR_VCPUS:
+		r = KVM_MAX_VCPUS;
+		break;
 	default:
 		r = 0;
 		break;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 94540b3c6872ead08c9e8cdad355224d89b7bd96..deb9c38f98e73ee5d2884de12b13272601096b0e 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -234,6 +234,7 @@ struct kvm_vapic_addr {
 #define KVM_CAP_VAPIC 6
 #define KVM_CAP_EXT_CPUID 7
 #define KVM_CAP_CLOCKSOURCE 8
+#define KVM_CAP_NR_VCPUS 9       /* returns max vcpus per vm */
 
 /*
  * ioctls for VM fds