Re: [PATCH v6 00/12] Add driver bpf hook for early packet drop and forwarding

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 08/07/2016 5:15 AM, Brenden Blanco wrote:
> This patch set introduces new infrastructure for programmatically
> processing packets in the earliest stages of rx, as part of an effort
> others are calling eXpress Data Path (XDP) [1]. Start this effort by
> introducing a new bpf program type for early packet filtering, before
> even an skb has been allocated.
>
> Extend on this with the ability to modify packet data and send back out
> on the same port.
>
> Patch 1 introduces the new prog type and helpers for validating the bpf
>    program. A new userspace struct is defined containing only data and
>    data_end as fields, with others to follow in the future.
> In patch 2, create a new ndo to pass the fd to supported drivers.
> In patch 3, expose a new rtnl option to userspace.
> In patch 4, enable support in mlx4 driver.
> In patch 5, create a sample drop and count program. With single core,
>    achieved ~20 Mpps drop rate on a 40G ConnectX3-Pro. This includes
>    packet data access, bpf array lookup, and increment.
> In patch 6, add a page recycle facility to mlx4 rx, enabled when xdp is
>    active.
> In patch 7, add the XDP_TX type to bpf.h
> In patch 8, add helper in tx patch for writing tx_desc
> In patch 9, add support in mlx4 for packet data write and forwarding
> In patch 10, turn on packet write support in the bpf verifier
> In patch 11, add a sample program for packet write and forwarding. With
>    single core, achieved ~10 Mpps rewrite and forwarding.
> In patch 12, add prefetch to mlx4 rx to bump forwarding to 12 Mpps
In general, I need some time (2-3 days) to run regression tests over 
this updated patch-set, as it does non-trivial changes to our mlx4_en 
data-path flows.
Other specific comments will be addressed separately.

Regards,
Tariq