mlx5dv_map_ah_to_qp(3)                                  mlx5dv_map_ah_to_qp(3)

NAME
       mlx5dv_map_ah_to_qp - Map the destination path information in address
       handle (AH) to the information extracted from the qp.

SYNOPSIS
              #include <infiniband/mlx5dv.h>

              int mlx5dv_map_ah_to_qp(struct ibv_ah *ah, uint32_t qp_num);

DESCRIPTION
       This API maps the destination path information in address handle (ah)
       to the information extracted from the qp (e.g. congestion control from
       ECE).

       This API serves as an enhancement to DC and UD QPs to achieve better
       performance by using per-address congestion control (CC) algorithms,
       enabling DC/UD QPs to use multiple CC algorithms in the same
       datacenter.

       The mapping created by this API is implicitly destroyed when the
       address handle is destroyed.  It is not affected by the destruction of
       QP qp_num.

       A duplicate mapping to the same address handle is ignored.  As this API
       is just a hint for the hardware in this case it would do nothing and
       return success regardless of the new qp_num ECE.

       The function must be called after ECE negotiation/preconfiguration was
       done by some external means.

ARGUMENTS
       ah     The target's address handle.

       qp_num The initiator QP from which congestion control information is
              extracted from its ECE.

RETURN VALUE
       Upon success, returns 0; Upon failure, the value of errno is returned.

SEE ALSO
       rdma_cm(7), rdma_get_remote_ece(3), ibv_query_ece(3), ibv_set_ece(3)

AUTHOR
       Yochai Cohen <yochai@nvidia.com>

       Patrisious Haddad <phaddad@nvidia.com>

                                                        mlx5dv_map_ah_to_qp(3)