[ovs-dev] [patch net-next v2 8/9] switchdev: introduce Netlink API

[Jiri Pirko]

Sat, Sep 20, 2014 at 01:32:30PM CEST, jhs at mojatatu.com wrote:
>On 09/20/14 07:01, Thomas Graf wrote:
>
>>Nothing speaks against having such a tc classifier. In fact, having
>>the interface consist of only an embedded Netlink attribute structure
>>would allow for such a classifier in a very straight forward way.
>>
>>That doesn't mean everybody should be forced to use the stateful
>>tc interface.
>>
>
>
>Agreed. The response was to Jiri's strange statement that now that
>he cant use OVS, there is no such api. I point to tc as very capable of
>such usage.

Jamal, would you please give us some examples on how to use tc to work
with flows? I have a feeling that you see something other people does not.
Lets get on the same page now.
Thanks.


>
>>No need for false accusations here. Nobody ever mentioned vendor SDKs.
>>
>
>I am sorry to have tied the two together. Maybe not OVS but the approach
>described is heaven for vendor SDKs.
>
>>The statement was that the requirement of deriving hardware flows from
>>software flows *in the kernel* is not flexible enough for the future
>>for reasons such as:
>>
>>1) The OVS software data path might be based on eBPF in the future and
>>    it is unclear how we could derive hardware flows from that
>>    transparently.
>>
>
>Who says you cant put BPF in hardware?
>And why is OVS defining how BPF should evolve or how it should be used?
>
>>2) Depending on hardware capabilities. Hardware flows might need to be
>>    assisted by software flow counterparts and it is believed that it
>>    is the wrong approach to push all the necessary context for the
>>    decision down into the kernel. This can be argued about and I don't
>>    feel strongly either way.
>>
>
>Pointing to the current FDB offload: You can select to bypass
>and not use s/ware.
>
>cheers,
>jamal