RE: [PATCH 1/4] vdpa/mlx5: Fix rule forwarding VLAN to TIR

[Eli Cohen]

> From: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
> Sent: Tuesday, 18 October 2022 22:21
> To: Eli Cohen <elic@xxxxxxxxxx>; mst@xxxxxxxxxx; jasowang@xxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
> Cc: eperezma@xxxxxxxxxx; lulu@xxxxxxxxxx
> Subject: Re: [PATCH 1/4] vdpa/mlx5: Fix rule forwarding VLAN to TIR
> 
> Hi Eli,
> 
> It's not for this patch but something related, so just a friendly
> heads-up. I haven't validated the VLAN tagging behavior yet for mlx5
> vdpa, but from my quick read of the code it doesn't seem it
> differentiates the case with and without VIRTIO_NET_F_CTRL_VLAN, to be
> compatible/compliant with what's been implemented in QEMU software (a
> spec addendum was filed as requested by Michael):
> 
> https://github.com/oasis-tcs/virtio-spec/issues/147
> 
> - when VIRTIO_NET_F_CTRL_VLAN is negotiated, the device starts with
> all VLANs filtered (meaning only untagged traffic can be received,
> and traffic with VLAN tag will be dropped).
> 
> - when VIRTIO_NET_F_CTRL_VLAN is not negotiated, all traffic including
> untagged and tagged can be received.
> 
> Can you please help check if we need further fix in terms of VLAN tagging?
> 

Sure. It's broken today. I will fix this to conform to the above requirements and send V1.

> Thanks,
> -Siwei
> 
> 
> On 10/18/2022 4:12 AM, Eli Cohen wrote:
> > Set the VLAN id to the header values field instead of overwriting the
> > headers criteria field.
> >
> > Before this fix, VLAN filtering would not really work and tagged packets
> > would be forwarded unfiltered to the TIR.
> >
> > Fixes: baf2ad3f6a98 ("vdpa/mlx5: Add RX MAC VLAN filter support")
> >
> > Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
> Reviewed-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
> 
> > ---
> >   drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index 90913365def4..dd29fdfc24ed 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -1472,7 +1472,7 @@ static int mlx5_vdpa_add_mac_vlan_rules(struct
> mlx5_vdpa_net *ndev, u8 *mac,
> >   	if (tagged) {
> >   		MLX5_SET(fte_match_set_lyr_2_4, headers_v, cvlan_tag, 1);
> >   		MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, headers_c,
> first_vid);
> > -		MLX5_SET(fte_match_set_lyr_2_4, headers_c, first_vid, vid);
> > +		MLX5_SET(fte_match_set_lyr_2_4, headers_v, first_vid, vid);
> >   	}
> >   	flow_act.action = MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;
> >   	dest.type = MLX5_FLOW_DESTINATION_TYPE_TIR;