-#define V9FS_RDONLY 0x00000020
-#define V9FS_PROXY_SOCK_FD 0x00000040
-#define V9FS_PROXY_SOCK_NAME 0x00000080
+/*
+ * uid/gid part of .virtfs_meatadata namespace
+ */
+#define V9FS_SM_MAPPED_FILE 0x00000020
+#define V9FS_RDONLY 0x00000040
+#define V9FS_PROXY_SOCK_FD 0x00000080
+#define V9FS_PROXY_SOCK_NAME 0x00000100
+/*
+ * multidevs option (either one of the two applies exclusively)
+ */
+#define V9FS_REMAP_INODES 0x00000200
+#define V9FS_FORBID_MULTIDEVS 0x00000400
+/*
+ * Disables certain performance warnings from being logged on host side.
+ */
+#define V9FS_NO_PERF_WARN 0x00000800