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, IBV_QPT_UD, IBV_QPT_RAW_PACKET or IBV_QPT_DRIVER */
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.
IBV_QPT_DRIVER does not represent a specific service and is used for vendor specific QP logic.
See Also
Referenced By
ibv_alloc_pd(3), ibv_attach_mcast(3), ibv_create_cq(3), ibv_create_cq_ex(3), ibv_modify_qp(3), ibv_modify_qp_rate_limit(3), ibv_open_qp(3), ibv_post_recv(3), ibv_post_send(3), ibv_post_srq_recv(3), ibv_query_port(3), ibv_query_qp(3), rdma_create_qp(3), rdma_destroy_qp(3).
The man page ibv_destroy_qp(3) is an alias of ibv_create_qp(3).