Currently, base and nb_queue in the tc_rxq and tc_txq information of queue and TC mapping on both TX and RX paths are uint8_t. The structure is as follows:
struct rte_eth_dcb_tc_queue_mapping { /** rx queues assigned to tc per Pool */ struct { uint8_t base; uint8_t nb_queue; } tc_rxq[ETH_MAX_VMDQ_POOL][ETH_DCB_NUM_TCS]; /** rx queues assigned to tc per Pool */ struct { uint8_t base; uint8_t nb_queue; } tc_txq[ETH_MAX_VMDQ_POOL][ETH_DCB_NUM_TCS]; }; However, these datas will be truncated when queue number under a TC is greater than 256. So it is necessay for data type of base and nb_queue to change from uint8_t to uint16_t.