[PATCH 0/4] RDMA/mlx5: Support DMABUF in umems and enable ATS

Jason Gunthorpe jgg at nvidia.com
Thu Sep 1 14:20:52 UTC 2022


This series adds support for DMABUF when creating a devx umem. devx umems
are quite similar to MR's execpt they cannot be revoked, so this uses the
dmabuf pinned memory flow. Several mlx5dv flows require umem and cannot
work with MR.

The intended use case is primarily for P2P transfers using dmabuf as a
handle to the underlying PCI BAR memory from the exporter. When a PCI
switch is present the P2P transfers can bypass the host bridge completely
and go directly through the switch. ATS allows this bypass to function in
more cases as translated TLPs issued after an ATS query allows the request
redirect setting to be bypassed in the switch.

Have mlx5 automatically use ATS in places where it makes sense.

Jason Gunthorpe (4):
  net/mlx5: Add IFC bits for mkey ATS
  RDMA/core: Add UVERBS_ATTR_RAW_FD
  RDMA/mlx5: Add support for dmabuf to devx umem
  RDMA/mlx5: Enable ATS support for MRs and umems

 drivers/infiniband/core/uverbs_ioctl.c   |  8 ++++
 drivers/infiniband/hw/mlx5/devx.c        | 55 +++++++++++++++++-------
 drivers/infiniband/hw/mlx5/mlx5_ib.h     | 36 ++++++++++++++++
 drivers/infiniband/hw/mlx5/mr.c          |  5 ++-
 include/linux/mlx5/mlx5_ifc.h            | 11 +++--
 include/rdma/uverbs_ioctl.h              | 13 ++++++
 include/uapi/rdma/mlx5_user_ioctl_cmds.h |  1 +
 7 files changed, 109 insertions(+), 20 deletions(-)


base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
-- 
2.37.2



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