RDMA: Introduce generic buffer descriptor infrastructure for umem

From: Jiri Pirko <jiri@nvidia.com>

This patchset introduces a generic buffer descriptor infrastructure
for passing memory buffers (dma-buf or user VA) to uverbs commands,
and wires it up for CQ and QP creation in the uverbs core, efa, mlx5,
bnxt_re and mlx4 drivers.

Instead of adding ad-hoc per-buffer UAPI attributes for each new buffer
type, each command declares dedicated UVERBS_ATTR_UMEM attributes that
carry one buffer descriptor each. Each descriptor specifies a buffer
type, covering both VA and dma-buf. A consumption check ensures
userspace and driver agree on which attributes are used.

The patchset:
1-2,4. Plumbing: rename ib_umem_get() to ib_umem_get_va() and re-route
   it through ib_umem_get_attr_or_va(); no behaviour change.
3. Introduces the core buffer descriptor infrastructure and UAPI.
5. Factors out CQ buffer umem processing into a helper.
6. Adds the CQ buffer UMEM attribute and driver wrappers.
7-10. Converts efa, mlx5, bnxt_re and mlx4 to use the new CQ helpers,
   with drivers taking umem ownership.
11. Removes the legacy umem field from struct ib_cq, now that all
   drivers use the new helpers.
12. Adds optional whole-QP, RQ and SQ UMEM attributes to QP creation.
13. Converts mlx5 QP creation to use the new attributes.
14-15. Adds mlx5 driver-namespace UMEM attributes for CQ and QP
   doorbell records.

---
Based on top of: jgg-for-next 9733e9f580fdda2e8c1cd349caddd93f026ab6f5

See individual patches for changelog.

v6: https://lore.kernel.org/all/20260520101129.899464-1-jiri@...
v5: https://lore.kernel.org/all/20260517063006.2200680-1-jiri...
v4: https://lore.kernel.org/all/20260507125231.2950751-1-jiri...
v3: https://lore.kernel.org/all/20260504135731.2345383-1-jiri...
v2: https://lore.kernel.org/all/20260411144915.114571-1-jiri@...
v1: https://lore.kernel.org/all/20260203085003.71184-1-jiri@r...

Note this re-works the original patchset trying to handle this:
https://lore.kernel.org/all/20260203085003.71184-1-jiri@r...
The code is so much different I'm sending this is a new patchset.

Jiri Pirko (15):
  RDMA/umem: Rename ib_umem_get() to ib_umem_get_va()
  RDMA/umem: Split ib_umem_get_va() into a thin wrapper around
    __ib_umem_get_va()
  RDMA/core: Introduce generic buffer descriptor infrastructure for umem
  RDMA/umem: Route ib_umem_get_va() through ib_umem_get_attr_or_va()
  RDMA/uverbs: Push out CQ buffer umem processing into a helper
  RDMA/uverbs: Add CQ buffer UMEM attribute and driver helpers
  RDMA/efa: Use ib_umem_get_cq_buf() for user CQ buffer
  RDMA/mlx5: Use ib_umem_get_cq_buf_or_va() for user CQ buffer
  RDMA/bnxt_re: Use ib_umem_get_cq_buf_or_va() for user CQ buffer
  RDMA/mlx4: Use ib_umem_get_cq_buf() for user CQ buffer
  RDMA/uverbs: Remove legacy umem field from struct ib_cq
  RDMA/uverbs: Use UMEM attributes for QP creation
  RDMA/mlx5: Use UMEM attributes for QP buffers in create_qp
  RDMA/mlx5: Use UMEM attribute for CQ doorbell record
  RDMA/mlx5: Use UMEM attribute for QP doorbell record

 drivers/infiniband/core/umem.c                | 336 +++++++++++++++++-
 drivers/infiniband/core/uverbs_cmd.c          |   1 -
 drivers/infiniband/core/uverbs_ioctl.c        |  25 ++
 drivers/infiniband/core/uverbs_std_types_cq.c |  73 +---
 drivers/infiniband/core/uverbs_std_types_qp.c |   6 +
 drivers/infiniband/core/verbs.c               |   7 -
 drivers/infiniband/hw/bnxt_re/ib_verbs.c      |  61 ++--
 drivers/infiniband/hw/bnxt_re/ib_verbs.h      |   1 +
 drivers/infiniband/hw/cxgb4/mem.c             |   2 +-
 drivers/infiniband/hw/efa/efa_verbs.c         |  29 +-
 drivers/infiniband/hw/erdma/erdma_verbs.c     |   6 +-
 drivers/infiniband/hw/hns/hns_roce_db.c       |   4 +-
 drivers/infiniband/hw/hns/hns_roce_mr.c       |   4 +-
 .../infiniband/hw/ionic/ionic_controlpath.c   |  10 +-
 drivers/infiniband/hw/irdma/verbs.c           |   4 +-
 drivers/infiniband/hw/mana/main.c             |   2 +-
 drivers/infiniband/hw/mana/mr.c               |   2 +-
 drivers/infiniband/hw/mlx4/cq.c               |  56 +--
 drivers/infiniband/hw/mlx4/doorbell.c         |   4 +-
 drivers/infiniband/hw/mlx4/mlx4_ib.h          |   1 +
 drivers/infiniband/hw/mlx4/mr.c               |   4 +-
 drivers/infiniband/hw/mlx4/qp.c               |   4 +-
 drivers/infiniband/hw/mlx4/srq.c              |   2 +-
 drivers/infiniband/hw/mlx5/cq.c               |  41 ++-
 drivers/infiniband/hw/mlx5/devx.c             |   2 +-
 drivers/infiniband/hw/mlx5/doorbell.c         |  93 ++++-
 drivers/infiniband/hw/mlx5/main.c             |   1 +
 drivers/infiniband/hw/mlx5/mlx5_ib.h          |   6 +-
 drivers/infiniband/hw/mlx5/mr.c               |   6 +-
 drivers/infiniband/hw/mlx5/qp.c               |  69 +++-
 drivers/infiniband/hw/mlx5/srq.c              |   4 +-
 drivers/infiniband/hw/mthca/mthca_provider.c  |   2 +-
 drivers/infiniband/hw/ocrdma/ocrdma_verbs.c   |   2 +-
 drivers/infiniband/hw/qedr/verbs.c            |  13 +-
 drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c  |   4 +-
 drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c  |   2 +-
 drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c  |  10 +-
 drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c |   2 +-
 drivers/infiniband/sw/rdmavt/mr.c             |   2 +-
 drivers/infiniband/sw/rxe/rxe_mr.c            |   2 +-
 drivers/infiniband/sw/siw/siw_mem.c           |   4 +-
 include/rdma/ib_umem.h                        |  71 +++-
 include/rdma/ib_verbs.h                       |   1 -
 include/rdma/uverbs_ioctl.h                   |  31 ++
 include/uapi/rdma/ib_user_ioctl_cmds.h        |   4 +
 include/uapi/rdma/ib_user_ioctl_verbs.h       |  27 ++
 include/uapi/rdma/mlx5_user_ioctl_cmds.h      |   5 +
 47 files changed, 783 insertions(+), 265 deletions(-)

-- 
2.54.0