Re: [dpdk-dev] [PATCH 00/13] cxgbe: add CXGBE VF PMD and updates

[Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>]

On Wednesday, March 03/28/18, 2018 at 10:19:17 +0530, Shahaf Shuler wrote:
> Tuesday, March 27, 2018 10:02 AM, Rahul Lakkireddy:
> 
> [...]
> 
> > > >
> > > > Patch 13 adds compile time option to keep outer vlan tag in Q-in-Q
> > > > packet.
> > >
> > > We are trying to reduce the config options, is it possible to provide
> > > this functionality with a runtime option (devargs) ?
> > >
> > 
> > Thank you for pointing to this. It seems like a good option.
> > 
> > > Or there is already an offload option DEV_RX_OFFLOAD_QINQ_STRIP, I
> > > guess this is different (is it?), if so does it make sense to have
> > > another offload option to cover your case?
> > >
> > >
> > 
> > Yes, this is different. Here, its about stripping or preserving Outer-VLAN tag
> > from double-vlan in Rx. We have few customers who need this for their use-
> > case. So, adding another offload option would also help. Let us know which is
> > preferred - either one, devargs OR another offload, seems fine.
> 
> What exactly is the offload you try to expose? To strip the inner VLAN while keeping the outer one? 
> 

Sorry about that, I should have provided more details on this earlier.
Chelsio hardware supports below for double-vlans:
1) Dropping Outer VLAN in hw; inner vlan is stripped and available as
packet metadata.
2) Preserving Outer VLAN so, Outer VLAN is stripped and available as
packet metadata. Inner VLAN is available as part of packet itself.

So, the configurability here is with respect to Outer VLAN and
subsequently what is available as part of packet metadata (outer or
inner vlan).  Inner VLAN gets retained in both cases.  However, based
on how Outer VLAN is configured, Inner VLAN will be available either
as packet metadata or as part of packet itself.

We are not very sure if DEV_RX_OFFLOAD_QINQ_STRIP could be used here.
If it holds the same meaning then we will use the same.

Thanks,
Rahul