[PATCH net-next v1] iou-zcrx: update documentation

[PATCH net-next v1] iou-zcrx: update documentation

[David Wei]

Update io_uring zc rx documentation with:

* Current supported NICs with minimum FW reqs
* Mellanox needs HW GRO explicitly enabled

Signed-off-by: David Wei <dw@davidwei.uk>
---
 Documentation/networking/iou-zcrx.rst | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/networking/iou-zcrx.rst b/Documentation/networking/iou-zcrx.rst
index 0127319b30bb..bfc08154e697 100644
--- a/Documentation/networking/iou-zcrx.rst
+++ b/Documentation/networking/iou-zcrx.rst
@@ -41,6 +41,16 @@ RSS
 In addition to flow steering above, RSS is required to steer all other non-zero
 copy flows away from queues that are configured for io_uring ZC Rx.
 
+Supported NICs
+==============
+
+Zero copy Rx currently support two NIC families:
+
+* Broadcom Thor (BCM95750x) family
+  * Minimum FW is 232
+* Mellanox ConnectX-7 (MT2910) family
+  * Minimum FW is 28.42
+
 Usage
 =====
 
@@ -57,6 +67,10 @@ Enable header/data split::
 
   ethtool -G eth0 tcp-data-split on
 
+Enable HW GRO (for Mellanox NICs)::
+
+  ethtool -K eth0 rx-gro-hw on
+
 Carve out half of the HW Rx queues for zero copy using RSS::
 
   ethtool -X eth0 equal 1
-- 
2.47.3

Re: [PATCH net-next v1] iou-zcrx: update documentation

[Jakub Kicinski]

On Tue, 19 Aug 2025 13:56:32 -0700 David Wei wrote:
> +Zero copy Rx currently support two NIC families:
> +
> +* Broadcom Thor (BCM95750x) family
> +  * Minimum FW is 232
> +* Mellanox ConnectX-7 (MT2910) family
> +  * Minimum FW is 28.42

The sub-bullets don't get rendered correctly it seems. HTML output
looks like this:

 * Broadcom Thor (BCM95750x) family * Minimum FW is 232
 ^                                  ^
  real bullet point                  just a * character

In general looks useful, I think we have a similar list of XDP features
somewhere. When you repost - could you CC the respective driver
maintainers? I suspect Micheal may tell us that Thor2 is also covered..
Also I think we should say "nVidia" now?
-- 
pw-bot: cr

Re: [PATCH net-next v1] iou-zcrx: update documentation

[Jamal Hadi Salim]

On Tue, Aug 19, 2025 at 4:57 PM David Wei <dw@davidwei.uk> wrote:
>
> Update io_uring zc rx documentation with:
>
> * Current supported NICs with minimum FW reqs
> * Mellanox needs HW GRO explicitly enabled
>
> Signed-off-by: David Wei <dw@davidwei.uk>
> ---
>  Documentation/networking/iou-zcrx.rst | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/Documentation/networking/iou-zcrx.rst b/Documentation/networking/iou-zcrx.rst
> index 0127319b30bb..bfc08154e697 100644
> --- a/Documentation/networking/iou-zcrx.rst
> +++ b/Documentation/networking/iou-zcrx.rst
> @@ -41,6 +41,16 @@ RSS
>  In addition to flow steering above, RSS is required to steer all other non-zero
>  copy flows away from queues that are configured for io_uring ZC Rx.
>
> +Supported NICs
> +==============
> +
> +Zero copy Rx currently support two NIC families:
> +
> +* Broadcom Thor (BCM95750x) family
> +  * Minimum FW is 232
> +* Mellanox ConnectX-7 (MT2910) family
> +  * Minimum FW is 28.42
> +

you missed the intel dpu/idpf - see:
https://netdevconf.info/0x19/docs/netdev-0x19-paper13-talk-slides/TheBattleOfTheZCs.pdf

cheers,
jamal

>  Usage
>  =====
>
> @@ -57,6 +67,10 @@ Enable header/data split::
>
>    ethtool -G eth0 tcp-data-split on
>
> +Enable HW GRO (for Mellanox NICs)::
> +
> +  ethtool -K eth0 rx-gro-hw on
> +
>  Carve out half of the HW Rx queues for zero copy using RSS::
>
>    ethtool -X eth0 equal 1
> --
> 2.47.3
>
>

Re: [PATCH net-next v1] iou-zcrx: update documentation

[Jakub Kicinski]

On Thu, 21 Aug 2025 00:34:34 -0400 Jamal Hadi Salim wrote:
> > +Zero copy Rx currently support two NIC families:
> > +
> > +* Broadcom Thor (BCM95750x) family
> > +  * Minimum FW is 232
> > +* Mellanox ConnectX-7 (MT2910) family
> > +  * Minimum FW is 28.42
> > +  
> 
> you missed the intel dpu/idpf 

I think you were using an out of tree driver?

But keep an eye out for GVE, there's a patch to support ZC there.

Re: [PATCH net-next v1] iou-zcrx: update documentation

[Jamal Hadi Salim]

On Thu, Aug 21, 2025 at 10:21 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Thu, 21 Aug 2025 00:34:34 -0400 Jamal Hadi Salim wrote:
> > > +Zero copy Rx currently support two NIC families:
> > > +
> > > +* Broadcom Thor (BCM95750x) family
> > > +  * Minimum FW is 232
> > > +* Mellanox ConnectX-7 (MT2910) family
> > > +  * Minimum FW is 28.42
> > > +
> >
> > you missed the intel dpu/idpf
>
> I think you were using an out of tree driver?
>

Ouch, yes - it was out of tree with a few bug fixes..

cheers,
jamal
> But keep an eye out for GVE, there's a patch to support ZC there.