netdev - Re: [PATCH net-next 8/9] eth: fbnic: Collect packet statistics for XDP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250724101822.GJ1150792@horms.kernel.org>
Date: Thu, 24 Jul 2025 11:18:22 +0100
From: Simon Horman <horms@...nel.org>
To: Mohsin Bashir <mohsin.bashr@...il.com>
Cc: netdev@...r.kernel.org, kuba@...nel.org, alexanderduyck@...com,
	andrew+netdev@...n.ch, davem@...emloft.net, edumazet@...gle.com,
	pabeni@...hat.com, vadim.fedorenko@...ux.dev, jdamato@...tly.com,
	sdf@...ichev.me, aleksander.lobakin@...el.com, ast@...nel.org,
	daniel@...earbox.net, hawk@...nel.org, john.fastabend@...il.com
Subject: Re: [PATCH net-next 8/9] eth: fbnic: Collect packet statistics for
 XDP

On Wed, Jul 23, 2025 at 07:59:25AM -0700, Mohsin Bashir wrote:
> Add support for XDP statistics collection and reporting via rtnl_link
> and netdev_queue API.
> 
> For XDP programs without frags support, fbnic requires MTU to be less
> than the HDS threshold. If an over-sized frame is received, the frame
> is dropped and recorded as rx_length_errors reported via ip stats to
> highlight that this is an error.
> 
> Signed-off-by: Jakub Kicinski <kuba@...nel.org>
> Signed-off-by: Mohsin Bashir <mohsin.bashr@...il.com>
> ---
>  .../device_drivers/ethernet/meta/fbnic.rst    | 10 +++++
>  .../net/ethernet/meta/fbnic/fbnic_netdev.c    | 30 +++++++++++++
>  drivers/net/ethernet/meta/fbnic/fbnic_txrx.c  | 44 +++++++++++++++++--
>  drivers/net/ethernet/meta/fbnic/fbnic_txrx.h  |  1 +
>  4 files changed, 82 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst b/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
> index afb8353daefd..ad5e2cba7afc 100644
> --- a/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
> +++ b/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
> @@ -160,3 +160,13 @@ behavior and potential performance bottlenecks.
>  	  credit exhaustion
>          - ``pcie_ob_rd_no_np_cred``: Read requests dropped due to non-posted
>  	  credit exhaustion
> +
> +XDP Length Error:
> +~~~~~~~~~~~~~~~~~
> +
> +For XDP programs without frags support, fbnic tries to make sure that MTU fits
> +into a single buffer. If an oversized frame is received and gets fragmented,
> +it is dropped and the following netlink counters are updated
> +   - ``rx-length``: number of frames dropped due to lack of fragmentation
> +   support in the attached XDP program
> +   - ``rx-errors``: total number of packets with errors received on the interface

Hi Mohsin,

make hmtldocs complains a bit about this:

  .../fbnic.rst:170: ERROR: Unexpected indentation. [docutils]
  .../fbnic.rst:171: WARNING: Bullet list ends without a blank line; unexpected unindent. [docutils]

Empirically, and I admit there was much trial and error involved,
I was able to address this by:
* adding a blank before the start of the list
* updating the indentation of the follow-on line of the first entry of the list

Your mileage may vary.

diff --git a/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst b/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
index ad5e2cba7afc..fb6559fa4be4 100644
--- a/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
+++ b/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
@@ -167,6 +167,7 @@ XDP Length Error:
 For XDP programs without frags support, fbnic tries to make sure that MTU fits
 into a single buffer. If an oversized frame is received and gets fragmented,
 it is dropped and the following netlink counters are updated
+
    - ``rx-length``: number of frames dropped due to lack of fragmentation
-   support in the attached XDP program
+     support in the attached XDP program
    - ``rx-errors``: total number of packets with errors received on the interface