+ * The user data is overwritten in the case of RTE_ETH_EVENT_VF_MBOX.
+ * This even occurs when a message from the VF is received by the PF.
+ * The user data is overwritten with struct rte_pmd_ixgbe_mb_event_param.
+ * This struct is defined in rte_pmd_ixgbe.h.
+ *