Re: [PATCH rdma-next 5/5] RDMA/mlx5: Expose steering anchor to userspace

[Saeed Mahameed <saeedm@nvidia.com>]

On 15 Jul 05:08, Jason Gunthorpe wrote:
>On Wed, Jul 13, 2022 at 03:31:33PM -0700, Saeed Mahameed wrote:
>> On 03 Jul 13:54, Saeed Mahameed wrote:
>> > From: Mark Bloch <mbloch@nvidia.com>
>> >
>> > Expose a steering anchor per priority to allow users to re-inject
>> > packets back into default NIC pipeline for additional processing.
>> >
>> > MLX5_IB_METHOD_STEERING_ANCHOR_CREATE returns a flow table ID which
>> > a user can use to re-inject packets at a specific priority.
>> >
>> > A FTE (flow table entry) can be created and the flow table ID
>> > used as a destination.
>> >
>> > When a packet is taken into a RDMA-controlled steering domain (like
>> > software steering) there may be a need to insert the packet back into
>> > the default NIC pipeline. This exposes a flow table ID to the user that can
>> > be used as a destination in a flow table entry.
>> >
>> > With this new method priorities that are exposed to users via
>> > MLX5_IB_METHOD_FLOW_MATCHER_CREATE can be reached from a non-zero UID.
>> >
>> > As user-created flow tables (via RDMA DEVX) are created with a non-zero UID
>> > thus it's impossible to point to a NIC core flow table (core driver flow tables
>> > are created with UID value of zero) from userspace.
>> > Create flow tables that are exposed to users with the shared UID, this
>> > allows users to point to default NIC flow tables.
>> >
>> > Steering loops are prevented at FW level as FW enforces that no flow
>> > table at level X can point to a table at level lower than X.
>> >
>> > Signed-off-by: Mark Bloch <mbloch@nvidia.com>
>> > Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
>> > Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
>> > ---
>> > drivers/infiniband/hw/mlx5/fs.c          | 138 ++++++++++++++++++++++-
>> > drivers/infiniband/hw/mlx5/mlx5_ib.h     |   6 +
>> > include/uapi/rdma/mlx5_user_ioctl_cmds.h |  17 +++
>>
>> Jason, Can you ack/nack ? This has uapi.. I need to move forward with this
>> submission.
>
>Yes, it looks fine, can you update the shared branch?
>

Applied to mlx5-next, you may pull.

>Jason