On Wed, 2017-09-27 at 13:11 +0200, Jiri Pirko wrote: > Wed, Sep 27, 2017 at 11:46:58AM CEST, pab...@redhat.com wrote: > > On Wed, 2017-09-27 at 11:17 +0200, Jiri Pirko wrote: > > > Wed, Sep 27, 2017 at 10:29:35AM CEST, pab...@redhat.com wrote: > > > > So it looks like the H/W offload hook will still be called with the > > > > same arguments in both case, and 'bad' rule will still be pushed to the > > > > H/W as the driver itself has no way to distinct between the two > > > > scenarios. > > > > > > Why "bad"? > > > > Such rule is coped differently by the SW and the HW data path. > > > > a rule like: > > > > tc filter add dev eth0 protocol ip parent ffff: flower \ > > enc_key_id 102 enc_dst_port 4789 src_ip 3.4.5.6 skip_hw \ > > action action mirred redirect eth0_vf_1 > > > > will match 0 packets, while: > > > > tc filter add dev eth0 protocol ip parent ffff: flower \ > > enc_key_id 102 enc_dst_port 4789 src_ip 3.4.5.6 skip_sw \ > > action action mirred redirect eth0_vf_1 > > > > [just flipped 'skip_sw' and 'skip_hw' ] > > will match the vxlan-tunneled packets. I understand that one of the > > design goal for the h/w offload path is being consistent with the sw > > one, but that does not hold in the above scenario. > > Sure, the consistency is important. Howcome "skip_hw" won't match and > "skip_sw" will match? What's different?
For the SW datapath, we need a metadata based/lwt tunnel to collect the tunnel information. eth0 is not a such device and does not provide the metadata. Any match on tunnel based field will fail - correctly. When the HW datapath is used, the underlaying NIC is programmed exactly as done when we replace eth0 with vxlan0. The programmed flow matches vxlan encapsulated traffic. Cheers, Paolo
