[ovs-dev] [PATCH branch-2.13] netdev-offload-dpdk: Support vxlan encap offload with load actions

[Ilya Maximets]

On 10/20/20 10:51 AM, Sriharsha Basavapatna wrote:
> On Mon, Oct 19, 2020 at 7:59 PM Ilya Maximets <i.maximets at ovn.org> wrote:
>>
>> On 10/18/20 9:10 AM, Eli Britstein wrote:
>>> Struct match has the tunnel values/masks in
>>> match->flow.tunnel/match->wc.masks.tunnel.
>>> Load actions such as load:0xa566c10->NXM_NX_TUN_IPV4_DST[],
>>> load:0xbba->NXM_NX_TUN_ID[] are utilizing the tunnel masks fields, but
>>> those should not be used for matching.
>>> Offloading fails if masks is not clear. Fix it by checking if tunnel is
>>> present.
>>>
>>> Signed-off-by: Eli Britstein <elibr at nvidia.com>
>>> ---
>>
>> Thanks, Eli.
>>
>> Harsha, Emma, could you, please, review/test this version?
>>
>> Best regards, Ilya Maximets.
> 
> Reviewed this change. Do we even need this backported to 2.13, since
> we don't support clone/tnl-push actions with offload ?

I think we could have metadata partially set even if we're not performing
clone/tnl-push actions.  Maybe something like this:

  table=0,in_port=1,ip,actions=load:0xbba->NXM_NX_TUN_ID[],goto_table(1)
  table=1,ip,nw_src=192.168.0.1,actions=load:0xa566c10->NXM_NX_TUN_IPV4_DST[],<out to tunnel>
  table=1,ip,nw_src=192.168.0.2,actions=drop

In this scenario packet that goes to 'drop' action might have tun_id set
in the metadata and we will not offload it.  I didn't test that though.
Does that make sense?

> 
> Thanks,
> -Harsha
>>
>>>  lib/netdev-offload-dpdk.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/lib/netdev-offload-dpdk.c b/lib/netdev-offload-dpdk.c
>>> index 4538baf5e..c68d539ea 100644
>>> --- a/lib/netdev-offload-dpdk.c
>>> +++ b/lib/netdev-offload-dpdk.c
>>> @@ -1092,7 +1092,8 @@ netdev_offload_dpdk_validate_flow(const struct match *match)
>>>      /* Create a wc-zeroed version of flow. */
>>>      match_init(&match_zero_wc, &match->flow, &match->wc);
>>>
>>> -    if (!is_all_zeros(&match_zero_wc.flow.tunnel,
>>> +    if (flow_tnl_dst_is_set(&match->flow.tunnel) &&
>>> +        !is_all_zeros(&match_zero_wc.flow.tunnel,
>>>                        sizeof match_zero_wc.flow.tunnel)) {
>>>          goto err;
>>>      }
>>>
>>