KVM: s390: Enable KVM_CAP_NR_MEMSLOTS on s390

Return KVM_USER_MEM_SLOTS in kvm_dev_ioctl_check_extension().
Signed-off-by: Nick Wang <jfwang@us.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

arch/s390/kvm/kvm-s390.c

@@ -149,6 +149,9 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
 		break;
+	case KVM_CAP_NR_MEMSLOTS:
+		r = KVM_USER_MEM_SLOTS;
+		break;
 	case KVM_CAP_S390_COW:
 		r = MACHINE_HAS_ESOP;
 		break;