KVM: Advertise synchronized mmu support to userspace

Signed-off-by: Avi Kivity <avi@qumranet.com>

arch/x86/kvm/x86.c

@@ -883,6 +883,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_PIT:
 	case KVM_CAP_NOP_IO_DELAY:
 	case KVM_CAP_MP_STATE:
+	case KVM_CAP_SYNC_MMU:
 		r = 1;
 		break;
 	case KVM_CAP_COALESCED_MMIO:

include/linux/kvm.h

@@ -371,6 +371,7 @@ struct kvm_trace_rec {
 #define KVM_CAP_PV_MMU 13
 #define KVM_CAP_MP_STATE 14
 #define KVM_CAP_COALESCED_MMIO 15
+#define KVM_CAP_SYNC_MMU 16  /* Changes to host mmap are reflected in guest */
 
 /*
  * ioctls for VM fds