.\" -*- nroff -*-
.\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md
.\"
.TH IBV_OPEN_QP 3 2011-08-12 libibverbs "Libibverbs Programmer's Manual"
.SH "NAME"
ibv_open_qp \- open a shareable queue pair (QP)
.SH "SYNOPSIS"
.nf
.B #include <infiniband/verbs.h>
.sp
.BI "struct ibv_qp *ibv_open_qp(struct ibv_context " "*context" ,
.BI "                           struct ibv_qp_open_attr " "*qp_open_attr" );
.fi
.SH "DESCRIPTION"
.B ibv_open_qp()
opens an existing queue pair (QP) associated with the extended protection domain
.I xrcd\fR.
The argument
.I qp_open_attr
is an ibv_qp_open_attr struct, as defined in <infiniband/verbs.h>.
.PP
.nf
struct ibv_qp_open_attr {
.in +8
uint32_t          comp_mask;  /* Identifies valid fields */
uint32_t          qp_num;     /* QP number */
struct            *ibv_xrcd;  /* XRC domain */
void             *qp_context; /* User defined opaque value */
enum ibv_qp_type  qp_type;    /* QP transport service type */
.fi
.PP
.B ibv_destroy_qp()
closes the opened QP and destroys the underlying QP if it has no
other references.
.I qp\fR.
.SH "RETURN VALUE"
.B ibv_open_qp()
returns a pointer to the opened QP, or NULL if the request fails.
Check the QP number (\fBqp_num\fR) in the returned QP.
.SH "NOTES"
.B ibv_open_qp()
will fail if a it is asked to open a QP that does not exist within
the xrcd with the specified qp_num and qp_type.
.SH "SEE ALSO"
.BR ibv_alloc_pd (3),
.BR ibv_create_qp (3),
.BR ibv_create_qp_ex (3),
.BR ibv_modify_qp (3),
.BR ibv_query_qp (3)
.SH "AUTHORS"
.TP
Sean Hefty <sean.hefty@intel.com>