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