1MLX5DV(7)              Miscellaneous Information Manual              MLX5DV(7)
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NAME

6       mlx5dv - Direct verbs for mlx5 devices
7       This  is  low  level access to mlx5 devices to perform data path opera‐
8       tions, without general branching performed by ibv_post_send(3).
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DESCRIPTION

12       The libibverbs API is an abstract one. It is agnostic to any underlying
13       provider specific implementation. While this abstraction has the advan‐
14       tage of user applications portability it has a performance penalty. For
15       some  applications optimizing performance is more important than porta‐
16       bility.
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18       The mlx5 direct verbs  API  is  intended  for  such  applications.   It
19       exposes  mlx5  specific  low  level data path (send/receive/completion)
20       operations, allowing the application to bypass the libibverbs data path
21       API.
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23       This  interface  consists  from  one hardware specific header file with
24       relevant inline functions and conversion logic from ibverbs  structures
25       to mlx5 specific structures.
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27       The  direct  include  of mlx5dv.h together with linkage to mlx5 library
28       will allow usage of this new interface.
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30       Once an application uses the direct flow the locking  scheme  is  fully
31       managed  by  itself. There is an expectation that no mixed flows in the
32       data path for both direct/non-direct access will be  by  same  applica‐
33       tion.
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NOTES

37       All  Mellanox  NIC  devices  starting from Connect-IB (Connect-IB, Con‐
38       nectX-4, ConnectX-4Lx, ConnectX-5, ...) implement the  mlx5  API,  thus
39       using the mlx5 direct verbs does not limit the applications to a single
40       NIC HW device thus keeping some level of portability.
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SEE ALSO

44       ibv_post_send(3), verbs(7)
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AUTHORS

48       Leon Romanovsky <leonro@mellanox.com>
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521.0.0                             2017-02-02                         MLX5DV(7)