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
drivers/net/ethernet/intel/ice/ice_tc_lib.c | 1 +
drivers/net/ethernet/intel/ice/ice_vsi_vlan_lib.c | 3 ++-
drivers/net/ethernet/intel/ice/virt/virtchnl.c | 6 ++++++
include/linux/avf/virtchnl.h | 1 +
4 files changed, 10 insertions(+), 1 deletion(-)
--
2.52.0
