RE: [PATCH net-next] net: prestera: flower template support

[Volodymyr Mytnyk]

Hi Jamal,

>
> > From: Volodymyr Mytnyk<vmytnyk@xxxxxxxxxxx>
> > 
> > Add user template explicit support. At this moment, max TCAM rule size 
> > is utilized for all rules, doesn't matter which and how much flower 
> > matches are provided by user. It means that some of TCAM space is 
> > wasted, which impacts the number of filters that can be offloaded.
> > 
> > Introducing the template, allows to have more HW offloaded filters.
> > 
> > Example:
> >    tc qd add dev PORT clsact
> >    tc chain add dev PORT ingress protocol ip \
> >      flower dst_ip 0.0.0.0/16
> 
> "chain" or "filter"?

tc chain add ... flower [tempalte] is the command to add explicitly chain with a given template

tc filter ... is the command to add a filter itself in that chain

> 
> >    tc filter add dev PORT ingress protocol ip \
> >      flower skip_sw dst_ip 1.2.3.4/16 action drop
> 
> You are not using tc priority? Above will result in two priorities (the 0.0.0.0 entry will be more important) and in classical flower approach two  different tables.
> I am wondering how you map the table to the TCAM.
> Is the priority sorting entirely based on masks in hardware?

Kernel tc filter priority is used as a priority for HW rule (see flower implementation).

> 
> cheers,
> jamal

Regards,
  Volodymyr