NAME¶
rdma_create_qp - Allocate a QP.
SYNOPSIS¶
#include <rdma/rdma_cma.h>
int rdma_create_qp (struct rdma_cm_id *id, struct
ibv_pd *pd, struct ibv_qp_init_attr
*qp_init_attr);
ARGUMENTS¶
- id
- RDMA identifier.
- pd
- Optional protection domain for the QP.
- qp_init_attr
- Initial QP attributes.
DESCRIPTION¶
Allocate a QP associated with the specified rdma_cm_id and transition it for
sending and receiving.
RETURN VALUE¶
Returns 0 on success, or -1 on error. If an error occurs, errno will be set to
indicate the failure reason.
NOTES¶
The rdma_cm_id must be bound to a local RDMA device before calling this
function, and the protection domain must be for that same device. QPs
allocated to an rdma_cm_id are automatically transitioned by the librdmacm
through their states. After being allocated, the QP will be ready to handle
posting of receives. If the QP is unconnected, it will be ready to post sends.
If a protection domain is not given - pd parameter is NULL - then the rdma_cm_id
will be created using a default protection domain. One default protection
domain is allocated per RDMA device.
The initial QP attributes are specified by the qp_init_attr parameter. The
send_cq and recv_cq fields in the ibv_qp_init_attr are optional. If a send or
receive completion queue is not specified, then a CQ will be allocated by the
rdma_cm for the QP, along with corresponding completion channels. Completion
channels and CQ data created by the rdma_cm are exposed to the user through
the rdma_cm_id structure.
The actual capabilities and properties of the created QP will be returned to the
user through the qp_init_attr parameter. An rdma_cm_id may only be associated
with a single QP.
SEE ALSO¶
rdma_bind_addr(3),
rdma_resolve_addr(3),
rdma_destroy_qp(3),
ibv_create_qp(3),
ibv_modify_qp(3)