MLX5DV(7) Miscellaneous Information Manual MLX5DV(7)
mlx5dv - Direct verbs for mlx5 devices This is low level access to mlx5 devices to perform data path operations, without general branching performed by ibv_post_send(3).
The libibverbs API is an abstract one. It is agnostic to any underlying provider specific implementation. While this abstraction has the advantage of user applications portability it has a performance penalty. For some applications optimizing performance is more important than portability. The mlx5 direct verbs API is intended for such applications. It exposes mlx5 specific low level data path (send/receive/completion) operations, allowing the application to bypass the libibverbs data path API. This interface consists from one hardware specific header file with relevant inline functions and conversion logic from ibverbs structures to mlx5 specific structures. The direct include of mlx5dv.h together with linkage to mlx5 library will allow usage of this new interface. Once an application uses the direct flow the locking scheme is fully managed by itself. There is an expectation that no mixed flows in the data path for both direct/non-direct access will be by same application.
All Mellanox NIC devices starting from Connect-IB (Connect-IB, ConnectX-4, ConnectX-4Lx, ConnectX-5, ...) implement the mlx5 API, thus using the mlx5 direct verbs does not limit the applications to a single NIC HW device thus keeping some level of portability.
ibv_post_send(3), verbs(7), mlx5dv_is_supported(3)
Leon Romanovsky <firstname.lastname@example.org>
This page is part of the rdma-core (RDMA Core Userspace Libraries and Daemons) project. Information about the project can be found at ⟨https://github.com/linux-rdma/rdma-core⟩. If you have a bug report for this manual page, send it to email@example.com. This page was obtained from the project's upstream Git repository ⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2021-08-27. (At that time, the date of the most recent commit that was found in the repository was 2021-08-18.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to firstname.lastname@example.org 1.0.0 2017-02-02 MLX5DV(7)
Pages that refer to this page: mlx5dv_get_clock_info(3), mlx5dv_init_obj(3), mlx5dv_query_device(3), mlx5dv_ts_to_ns(3)