Re: [PATCH net-next] bnxt_en: Allow ntuple filters for drops

[Michael Chan <michael.chan@broadcom.com>]

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On Wed, Jan 28, 2026 at 2:27 PM Joe Damato <joe@dama.to> wrote:
>
> It appears that in commit 7efd79c0e689 ("bnxt_en: Add drop action
> support for ntuple"), bnxt gained support for ntuple filters for packet
> drops.
>
> However, support for this does not seem to work in recent kernels or
> against net-next:
>
>   % sudo ethtool -U eth0 flow-type udp4 src-ip 1.1.1.1 action -1
>     rmgr: Cannot insert RX class rule: Operation not supported
>     Cannot insert classification rule
>
> The issue is that the existing code uses ethtool_get_flow_spec_ring_vf,
> which will return a non-zero value if the ring_cookie is set to
> RX_CLS_FLOW_DISC, which then causes bnxt_add_ntuple_cls_rule to return
> -EOPNOTSUPP because it thinks the user is trying to set an ntuple filter
> for a vf.
>
> Fix this by first checking that the ring_cookie is not RX_CLS_FLOW_DISC.

Please add the Fixes tag.  It looks like the drop action never worked
properly because of the vf check.

> ---
>  drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> index 6b15fedbb16f..fd32231bf8e0 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> @@ -1353,10 +1353,12 @@ static int bnxt_add_ntuple_cls_rule(struct bnxt *bp,
>         if (!bp->vnic_info)
>                 return -EAGAIN;
>
> -       vf = ethtool_get_flow_spec_ring_vf(fs->ring_cookie);
> -       ring = ethtool_get_flow_spec_ring(fs->ring_cookie);
> -       if ((fs->flow_type & (FLOW_MAC_EXT | FLOW_EXT)) || vf)
> -               return -EOPNOTSUPP;
> +       if (fs->ring_cookie != RX_CLS_FLOW_DISC) {
> +               vf = ethtool_get_flow_spec_ring_vf(fs->ring_cookie);
> +               ring = ethtool_get_flow_spec_ring(fs->ring_cookie);
> +               if ((fs->flow_type & (FLOW_MAC_EXT | FLOW_EXT)) || vf)

I think the FLOW_MAC_EXT and FLOW_EXT checks should be done unconditionally.

Alternatively, we can also change ethtool_get_flow_spec_ring_vf() to
check that the cookie is not RX_CLS_FLOW_DISC or RX_CLS_FLOW_WAKE.

Thanks.

> +                       return -EOPNOTSUPP;
> +       }

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