RDMA/mlx5: Use UMEM attribute for QP doorbell record

Add an optional mlx5 driver-namespace UMEM attribute on QP
create so userspace can supply the doorbell record umem
explicitly, symmetric to the CQ side. Resolve it inside
mlx5_ib_db_map_user() and use it as a private DBR page when
present; otherwise take the existing UHW share-or-pin path
that preserves per-page DBR sharing across CQ/QP/SRQ in the
same process.

Add mlx5's first UVERBS_OBJECT_QP UAPI definition chain to
attach the new attr.

Link: https://patch.msgid.link/r/20260529134312.2836341-17-jiri@resnulli.us
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

0 files changed, 0 insertions, 0 deletions