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

[Michael S. Tsirkin]

On Wed, Oct 19, 2022 at 05:31:48AM +0000, Eli Cohen wrote:
> > 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.

Did you mean v2?

> > 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;
>