diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index ae4b211..f36e6e0 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1942,7 +1942,8 @@ static int userfaultfd_move(struct userfaultfd_ctx *ctx,
 		return ret;
 
 	if (uffdio_move.mode & ~(UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES|
-				  UFFDIO_MOVE_MODE_DONTWAKE))
+				  UFFDIO_MOVE_MODE_DONTWAKE|
+				  UFFDIO_MOVE_MODE_CONFIRM_FIXED))
 		return -EINVAL;
 
 	if (mmget_not_zero(mm)) {
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 2be5c88..ffdbefb 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -325,6 +325,13 @@ struct uffdio_move {
 	 */
 #define UFFDIO_MOVE_MODE_DONTWAKE		((__u64)1<<0)
 #define UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES	((__u64)1<<1)
+	/*
+	 * To confirm if the ioctl has fixes to avoid panic when src folio is
+	 * in swap-cache. Also, to avoid livelock when multiple threads try
+	 * to move same src folio. It's a KMI workaround and cannot be relied
+	 * upon by userspace.
+	 */
+#define UFFDIO_MOVE_MODE_CONFIRM_FIXED		((__u64)1<<63)
 	__u64 mode;
 	/*
 	 * "move" is written by the ioctl and must be at the end: the