Subject: Re: [PATCH net 3/3] iavf: do not track VLAN 0 filters

From: Leon Romanovsky <[email-masked]>
Date: Wed, 15 Mar 2023 10:48:56 +0200

On Tue, Mar 14, 2023 at 10:44:23AM -0700, Tony Nguyen wrote:
> From: Ahmed Zaki <[email-masked]>
> 
> When an interface with the maximum number of VLAN filters is brought up,
> a spurious error is logged:
> 
>     [257.483082] 8021q: adding VLAN 0 to HW filter on device enp0s3
>     [257.483094] iavf 0000:00:03.0 enp0s3: Max allowed VLAN filters 8. Remove existing VLANs or disable filtering via Ethtool if supported.
> 
> The VF driver complains that it cannot add the VLAN 0 filter.
> 
> On the other hand, the PF driver always adds VLAN 0 filter on VF
> initialization. The VF does not need to ask the PF for that filter at
> all.
> 
> Fix the error by not tracking VLAN 0 filters altogether. With that, the
> check added by commit 0e710a3ffd0c ("iavf: Fix VF driver counting VLAN 0
> filters") in iavf_virtchnl.c is useless and might be confusing if left as
> it suggests that we track VLAN 0.
> 
> Fixes: 0e710a3ffd0c ("iavf: Fix VF driver counting VLAN 0 filters")
> Signed-off-by: Ahmed Zaki <[email-masked]>
> Reviewed-by: Michal Kubiak <[email-masked]>
> Tested-by: Rafal Romanowski <[email-masked]>
> Signed-off-by: Tony Nguyen <[email-masked]>
> ---
>  drivers/net/ethernet/intel/iavf/iavf_main.c     | 4 ++++
>  drivers/net/ethernet/intel/iavf/iavf_virtchnl.c | 2 --
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
> index 3273aeb8fa67..eb8f944276ff 100644
> --- a/drivers/net/ethernet/intel/iavf/iavf_main.c
> +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
> @@ -893,6 +893,10 @@ static int iavf_vlan_rx_add_vid(struct net_device *netdev,
>  {
>  	struct iavf_adapter *adapter = netdev_priv(netdev);
>  
> +	/* Do not track VLAN 0 filter, always added by the PF on VF init */
> +	if (!vid)
> +		return 0;

I would expect similar check in iavf_vlan_rx_kill_vid(),

Thanks

> +
>  	if (!VLAN_FILTERING_ALLOWED(adapter))
>  		return -EIO;
>  
> diff --git a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
> index 6d23338604bb..4e17d006c52d 100644
> --- a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
> +++ b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
> @@ -2446,8 +2446,6 @@ void iavf_virtchnl_completion(struct iavf_adapter *adapter,
>  		list_for_each_entry(f, &adapter->vlan_filter_list, list) {
>  			if (f->is_new_vlan) {
>  				f->is_new_vlan = false;
> -				if (!f->vlan.vid)
> -					continue;
>  				if (f->vlan.tpid == ETH_P_8021Q)
>  					set_bit(f->vlan.vid,
>  						adapter->vsi.active_cvlans);
> -- 
> 2.38.1
>