On Sat, 23 Jan 2021 17:28:02 +0200 Ido Schimmel wrote:
> > Thanks for the explanation. I feel more and more convinced now that
> > we should have TC_ACT_TRAP_MIRROR and the devlink trap should only
> > be on/off :S Current model of "if ACT_TRAP consult devlink for trap
> > configuration" is impossible to model in SW since it doesn't have a
> > equivalent of devlink traps. Or we need that equivalent..
>
> Wait, the current model is not "if ACT_TRAP consult devlink for trap
> configuration". 'ecn_mark' action is always 'trap' ('mirror' in v2) and
> can't be changed. Such packets can always be sent to the CPU, but the
> decision of whether to send them or not is based on the presence of tc
> filters attached to RED's 'mark' qevent with TC_ACT_TRAP
> (TC_ACT_TRAP_MIRROR in v2).
I see, missed that, but I think my point conceptually stands, right?
Part of forwarding behavior was (in v1) only expressed in control
plane (devlink) not dataplane (tc).
> I believe that with the proposed changes in v2 it should be perfectly
> clear that ECN marked packets are forwarded in hardware and a copy is
> sent to the CPU.
Yup, sounds good.
