RE: [PATCH] doc: relate bifurcated driver and flow isolated mode

[Dariusz Sosnowski <dsosnowski@nvidia.com>]

Hi Thomas,

> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Wednesday, September 14, 2022 23:30
> To: dev@dpdk.org
> Cc: Michael Savisko <michaelsav@nvidia.com>; Slava Ovsiienko
> <viacheslavo@nvidia.com>; Matan Azrad <matan@nvidia.com>; Dariusz
> Sosnowski <dsosnowski@nvidia.com>; Asaf Penso <asafp@nvidia.com>; Ori
> Kam <orika@nvidia.com>; Ferruh Yigit <ferruh.yigit@xilinx.com>; Andrew
> Rybchenko <andrew.rybchenko@oktetlabs.ru>
> Subject: [PATCH] doc: relate bifurcated driver and flow isolated mode
> 
> External email: Use caution opening links or attachments
> 
> 
> The relation between the isolated mode in ethdev flow API and bifurcated
> driver behaviour was not clearly explained.
> 
> It is made clear in the how-to guide that isolated mode is required for flow
> bifurcation to the kernel.
> On the other side, the impact of the isolated mode on a bifurcated driver is
> made more explicit.
> 
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> ---
>  doc/guides/howto/flow_bifurcation.rst | 3 ++-
>  lib/ethdev/rte_flow.h                 | 4 ++++
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/doc/guides/howto/flow_bifurcation.rst
> b/doc/guides/howto/flow_bifurcation.rst
> index 7ba66b9003..79cf4f1e64 100644
> --- a/doc/guides/howto/flow_bifurcation.rst
> +++ b/doc/guides/howto/flow_bifurcation.rst
> @@ -55,7 +55,8 @@ The full device is already shared with the kernel driver.
>  The DPDK application can setup some flow steering rules,  and let the rest go
> to the kernel stack.
>  In order to define the filters strictly with flow rules, -the
> :ref:`flow_isolated_mode` can be configured.
> +the :ref:`flow_isolated_mode` must be configured, so there is no
> +default rule routing traffic to userspace.
> 
>  There is no specific instructions to follow.
>  The recommended reading is the :doc:`../prog_guide/rte_flow` guide.
> diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h index
> a79f1e7ef0..1bac3fd9ec 100644
> --- a/lib/ethdev/rte_flow.h
> +++ b/lib/ethdev/rte_flow.h
> @@ -4254,6 +4254,10 @@ rte_flow_query(uint16_t port_id,
>   *
>   * Isolated mode guarantees that all ingress traffic comes from defined flow
>   * rules only (current and future).
> + * When enabled with a bifurcated driver,
> + * non-matched packets are routed to the kernel driver interface.
> + * When disabled (the default),
> + * there may be some default rules routing traffic to the DPDK port.
>   *
>   * Besides making ingress more deterministic, it allows PMDs to safely reuse
>   * resources otherwise assigned to handle the remaining traffic, such as
> --
> 2.36.1

Looks good to me. Thank you.

Reviewed-by: Dariusz Sosnowski <dsosnowski@nvidia.com>

Best regards,
Dariusz Sosnowski