mlx5dv_create_cq(3) mlx5 Programmer’s Manual mlx5dv_create_cq(3)

mlx5dv_create_cq - creates a completion queue (CQ)

#include <infiniband/mlx5dv.h>
struct ibv_cq_ex *mlx5dv_create_cq(struct ibv_context *context,

struct ibv_cq_init_attr_ex *cq_attr,
struct mlx5dv_cq_init_attr *mlx5_cq_attr);

mlx5dv_create_cq() creates a completion queue (CQ) with specific driver properties.

Please see ibv_create_cq_ex(3) man page for context and cq_attr

struct mlx5dv_cq_init_attr {

uint64_t comp_mask;
uint8_t cqe_comp_res_format;
uint32_t flags;
uint16_t cqe_size; };
Bitmask specifying what fields in the structure are valid:

MLX5DV_CQ_INIT_ATTR_MASK_COMPRESSED_CQE enables creating a CQ in a mode that few CQEs may be compressed into a single CQE, valid values in cqe_comp_res_format

MLX5DV_CQ_INIT_ATTR_MASK_FLAGS valid values in flags

MLX5DV_CQ_INIT_ATTR_MASK_CQE_SIZE valid values in cqe_size

A bitwise OR of the various CQE response formats of the responder side:

MLX5DV_CQE_RES_FORMAT_HASH CQE compression with hash

MLX5DV_CQE_RES_FORMAT_CSUM CQE compression with RX checksum

MLX5DV_CQE_RES_FORMAT_CSUM_STRIDX CQE compression with stride index

A bitwise OR of the various values described below:


configure the CQE size to be 64 or 128 bytes other values will fail mlx5dv_create_cq.

mlx5dv_create_cq() returns a pointer to the created CQ, or NULL if the request fails and errno will be set.


Yonatan Cohen <>

2018-9-1 mlx5