RE: [PATCH net-next] net: mana: Add support for vlan tagging

[Haiyang Zhang]

> -----Original Message-----
> From: LKML haiyangz <lkmlhyz@xxxxxxxxxxxxx> On Behalf Of Haiyang Zhang
> Sent: Wednesday, June 7, 2023 2:38 PM
> To: linux-hyperv@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; Dexuan Cui
> <decui@xxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx>; Paul Rosswurm
> <paulros@xxxxxxxxxxxxx>; olaf@xxxxxxxxx; vkuznets@xxxxxxxxxx;
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> <longli@xxxxxxxxxxxxx>; ssengar@xxxxxxxxxxxxxxxxxxx; linux-
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> Subject: [PATCH net-next] net: mana: Add support for vlan tagging
> 
> To support vlan, use MANA_LONG_PKT_FMT if vlan tag is present in TX
> skb. Then extract the vlan tag from the skb struct or the frame, and
> save it to tx_oob for the NIC to transmit.
> 
> For RX, extract the vlan tag from CQE and put it into skb.
> 
> Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 36
> +++++++++++++++++--
>  1 file changed, 34 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c
> b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index d907727c7b7a..1d76ac66908c 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -179,6 +179,31 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb,
> struct net_device *ndev)
>  		pkg.tx_oob.s_oob.short_vp_offset = txq->vp_offset;
>  	}
> 
> +	/* When using AF_PACKET we need to move VLAN header from
> +	 * the frame to the SKB struct to allow the NIC to xmit
> +	 * the 802.1Q packet.
> +	 */
> +	if (skb->protocol == htons(ETH_P_8021Q)) {
> +		u16 vlan_tci;
> +
> +		skb_reset_mac_header(skb);
> +		if (eth_type_vlan(eth_hdr(skb)->h_proto)) {
> +			if (unlikely(__skb_vlan_pop(skb, &vlan_tci)))
> +				goto tx_drop_count;
> +
> +			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
> +					       vlan_tci);
> +		}
> +	}

Not necessary to extract inband tag, because our NIC accepts inband tags too.
The change is in the next version.