ibv_create_qp(3) [debian man page]

IBV_CREATE_QP(3)					  Libibverbs Programmer's Manual					  IBV_CREATE_QP(3)

NAME

       ibv_create_qp, ibv_destroy_qp - create or destroy a queue pair (QP)

SYNOPSIS

       #include <infiniband/verbs.h>

       struct ibv_qp *ibv_create_qp(struct ibv_pd *pd,
				    struct ibv_qp_init_attr *qp_init_attr);

       int ibv_destroy_qp(struct ibv_qp *qp);

DESCRIPTION

       ibv_create_qp()	creates  a  queue  pair  (QP)  associated with the protection domain pd.  The argument qp_init_attr is an ibv_qp_init_attr
       struct, as defined in <infiniband/verbs.h>.

       struct ibv_qp_init_attr {
	       void		      *qp_context;     /* Associated context of the QP */
	       struct ibv_cq	      *send_cq;        /* CQ to be associated with the Send Queue (SQ) */
	       struct ibv_cq	      *recv_cq;        /* CQ to be associated with the Receive Queue (RQ) */
	       struct ibv_srq	      *srq;	       /* SRQ handle if QP is to be associated with an SRQ, otherwise NULL */
	       struct ibv_qp_cap       cap;	       /* QP capabilities */
	       enum ibv_qp_type        qp_type;        /* QP Transport Service Type: IBV_QPT_RC, IBV_QPT_UC, or IBV_QPT_UD */
	       int		       sq_sig_all;     /* If set, each Work Request (WR) submitted to the SQ generates a completion entry */
       };

       struct ibv_qp_cap {
	       uint32_t 	       max_send_wr;    /* Requested max number of outstanding WRs in the SQ */
	       uint32_t 	       max_recv_wr;    /* Requested max number of outstanding WRs in the RQ */
	       uint32_t 	       max_send_sge;   /* Requested max number of scatter/gather (s/g) elements in a WR in the SQ */
	       uint32_t 	       max_recv_sge;   /* Requested max number of s/g elements in a WR in the SQ */
	       uint32_t 	       max_inline_data;/* Requested max number of data (bytes) that can be posted inline to the SQ, otherwise 0 */
       };

       The function ibv_create_qp() will update the qp_init_attr->cap struct with the actual QP values of the QP that was created; the values will
       be greater than or equal to the values requested.

       ibv_destroy_qp() destroys the QP qp.

RETURN VALUE

       ibv_create_qp() returns a pointer to the created QP, or NULL if the request fails.  Check the QP number (qp_num) in the returned QP.

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

NOTES

       ibv_create_qp() will fail if a it is asked to create QP of a type other than IBV_QPT_RC or IBV_QPT_UD associated with an SRQ.

       The attributes max_recv_wr and max_recv_sge are ignored by ibv_create_qp() if the QP is to be associated with an SRQ.

       ibv_destroy_qp() fails if the QP is attached to a multicast group.

SEE ALSO

       ibv_alloc_pd(3), ibv_modify_qp(3), ibv_query_qp(3)

AUTHORS

       Dotan Barak <dotanba@gmail.com>

libibverbs							    2006-10-31							  IBV_CREATE_QP(3)

Check Out this Related Man Page

IBV_POST_SRQ_RECV(3)					  Libibverbs Programmer's Manual				      IBV_POST_SRQ_RECV(3)

NAME

       ibv_post_srq_recv - post a list of work requests (WRs) to a shared receive queue (SRQ)

SYNOPSIS

       #include <infiniband/verbs.h>

       int ibv_post_srq_recv(struct ibv_srq *srq, struct ibv_recv_wr *wr,
			     struct ibv_recv_wr **bad_wr);

DESCRIPTION

       ibv_post_srq_recv() posts the linked list of work requests (WRs) starting with wr to the shared receive queue (SRQ) srq.  It stops process-
       ing 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_srq_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 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_recv(3), ibv_poll_cq(3)

AUTHORS

       Dotan Barak <dotanba@gmail.com>

libibverbs							    2006-10-31						      IBV_POST_SRQ_RECV(3)

Linux and UNIX Man Pages

ibv_create_qp(3) [debian man page]

Check Out this Related Man Page