NAME

       ibv_post_recv - post a list of work requests (WRs) to a receive queue

SYNOPSIS

       #include <infiniband/verbs.h>

       int ibv_post_recv(struct ibv_qp *qp, struct ibv_recv_wr *wr,
                         struct ibv_recv_wr **bad_wr);

DESCRIPTION

       ibv_post_recv()  posts  the  linked  list  of  work requests (WRs) starting with wr to the
       receive queue of the queue pair qp.  It stops processing WRs from this list at  the  first
       failure  (that  can  be detected immediately while requests are being posted), and returns
       this failing WR through bad_wr.

       The argument wr is an ibv_recv_wr struct, as defined in <infiniband/verbs.h>.

       struct ibv_recv_wr {
               uint64_t                wr_id;     /* User defined WR ID */
               struct ibv_recv_wr     *next;      /* Pointer to next WR in list, NULL if last WR */
               struct ibv_sge         *sg_list;   /* Pointer to the s/g array */
               int                     num_sge;   /* Size of the s/g array */
       };

       struct ibv_sge {
               uint64_t                addr;      /* Start address of the local memory buffer */
               uint32_t                length;    /* Length of the buffer */
               uint32_t                lkey;      /* Key of the local Memory Region */
       };

RETURN VALUE

       ibv_post_recv() returns 0 on success, or the value of errno on  failure  (which  indicates
       the failure reason).

NOTES

       The  buffers used by a WR can only be safely reused after WR the request is fully executed
       and a work completion has been retrieved from the corresponding completion queue (CQ).

       If the QP qp is associated with  a  shared  receive  queue,  you  must  use  the  function
       ibv_post_srq_recv(), and not ibv_post_recv(), since the QP's own receive queue will not be
       used.

       If a WR is being posted to a UD QP, the  Global  Routing  Header  (GRH)  of  the  incoming
       message  will be placed in the first 40 bytes of the buffer(s) in the scatter list.  If no
       GRH is present in the incoming message, then the first  bytes  will  be  undefined.   This
       means  that  in all cases, the actual data of the incoming message will start at an offset
       of 40 bytes into the buffer(s) in the scatter list.

SEE ALSO

       ibv_create_qp(3), ibv_post_send(3), ibv_post_srq_recv(3), ibv_poll_cq(3)

AUTHORS

       Dotan Barak <dotanba@gmail.com>