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

Jason Gunthorpe jgg at nvidia.com
Mon Sep 26 17:51:27 UTC 2022


On Thu, Sep 01, 2022 at 11:20:52AM -0300, Jason Gunthorpe wrote:
> 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(-)

Applied to for-next, thanks

Jason


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