UBLK_QID_BITS
#define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1)
#define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS)
#define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS)