NVME_MDTS
#define NVME_MAX_IOVEC ((1 << NVME_MDTS) + 1)
#define NVME_MAX_DATA_SIZE ((1 << NVME_MDTS) * NVME_MPSMIN_BYTES)
cd->mdts = NVME_MDTS; /* max data transfer size (2^mdts * CAP.MPSMIN) */