Index: /trunk/include/VBox/VMMDev.h
===================================================================
--- /trunk/include/VBox/VMMDev.h	(revision 50510)
+++ /trunk/include/VBox/VMMDev.h	(revision 50511)
@@ -509,4 +509,6 @@
  * not. */
 #define VMMDEV_GUEST_SUPPORTS_GRAPHICS                      RT_BIT_32(2)
+/** The mask of valid events, for sanity checking. */
+#define VMMDEV_GUEST_CAPABILITIES                           UINT32_C(0x00000007)
 /** @} */