NAME

       mlx5dv_reserved_qpn_alloc - Allocate a reserved QP number from device

       mlx5dv_reserved_qpn_dealloc - Release the reserved QP number

SYNOPSIS

              #include <infiniband/mlx5dv.h>

              int mlx5dv_reserved_qpn_alloc(struct ibv_context *ctx, uint32_t *qpn);

              int mlx5dv_reserved_qpn_dealloc(struct ibv_context *ctx, uint32_t qpn);

DESCRIPTION

       When  work  with  RDMA_CM  RDMA_TCP_PS  +  external  QP support, a client node needs GUID level unique QP
       numbers to comply with the CM’s timewait logic.

       If a real unique QP is not allocated, a device global QPN value is required and can be allocated via this
       interface.

       The mlx5 DCI QP is such an example, which could connect to the remote DCT’s multiple times as long as the
       application provides unique QPN for each new RDMA_CM connection.

       These 2 APIs provide the allocation/deallocation of a unique QP number from/to device.  This qpn  can  be
       used  with  DC  QPN  in  RDMA_CM  connection establishment, which will comply with the CM timewait kernel
       logic.

ARGUMENTS

       ctx    The device context to issue the action on.

       qpn    The allocated QP number (for alloc API), or the QP number to be deallocated (for dealloc API).

RETURN VALUE

       0 on success; EOPNOTSUPP if not supported, or other errno value on other failures.

AUTHOR

       Mark Zhang <markzhang@nvidia.com>

       Alex Rosenbaum <alexr@nvidia.com>