RISCV_IOMMU_CQH
q->head_off = (uint32_t)base - RISCV_IOMMU_CQB + RISCV_IOMMU_CQH;
#define QUEUE_HEAD(q) ((q)->csr + RISCV_IOMMU_CQH - RISCV_IOMMU_CQB)