Re: [PATCH net-next v1 0/2] virtchnl/ice: add IEEE 802.1ah (0x88E7) VLAN ethertype support

[Simon Horman <horms@kernel.org>]

On Wed, Mar 18, 2026 at 09:07:34AM +0100, Aleksandr Loktionov wrote:
> IEEE 802.1ah (Provider Backbone Bridging) defines the Backbone Service
> Tag (B-TAG) with ethertype 0x88E7. In environments that combine Provider
> Backbone Bridging with virtualisation, VFs may receive or transmit frames
> carrying a B-TAG and need to install matching VLAN filters on the PF.
> 
> The existing virtchnl VLAN v2 capability handshake (via
> VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS) has dedicated bitmask entries for
> each supported ethertype (0x8100, 0x88A8, 0x9100) but lacked one for
> 0x88E7, making it impossible for a VF driver to advertise or negotiate
> B-TAG support.
> 
> This series adds the missing capability flag and wires up the three
> software-path checks in the ice PF driver that guard VLAN filter
> installation:
> 
>   Patch 1 adds VIRTCHNL_VLAN_ETHERTYPE_88E7 = BIT(3) to the shared
>   virtchnl_vlan_support enum in include/linux/avf/virtchnl.h.
> 
>   Patch 2 updates ice's TC TPID validation, VSI VLAN filter validation,
>   and the bidirectional virtchnl VLAN v2 translation functions to
>   accept/translate ETH_P_8021AH (0x88E7).
> 
> No hardware offload changes, no datapath modifications.
> 
> Tested on E810 with an iavf VF requesting 0x88E7-tagged VLAN filters:
>   Verified that a TC flower rule matching on VLAN TPID 0x88E7 is now
>   accepted and offloaded by the driver without returning -EINVAL:
> 
>     tc qdisc add dev $VF clsact
>     tc filter add dev $VF ingress protocol 802.1Q flower \
>         vlan_ethtype 0x88e7 action pass
>     # (previously: Error: Failed to offload TC filter - vlan_type was 0)
> 
>   Also verified VF transparent passthrough of triple-tagged frames with
>   0x88E7 as middle and innermost tag using scapy on a back-to-back E810
>   pair (kernel 6.19.0-rc8+, FW 4.91, ICE Triple VLAN Comms DDP 1.3.88.88).
> 
> Aleksandr Loktionov (2):
>   virtchnl: add VIRTCHNL_VLAN_ETHERTYPE_88E7 support
>   ice: add 0x88E7 handling to SW validation paths

For the series:

Reviewed-by: Simon Horman <horms@kernel.org>