On 09/20/14 at 07:32am, Jamal Hadi Salim wrote: > I am sorry to have tied the two together. Maybe not OVS but the approach > described is heaven for vendor SDKs.
I fail to see the connection. You can use switch vendor SDK no matter how we define the kernel APIs. They already exist and have been designed in a way to be completely indepenedent from the kernel. Are you referring to vendor specific decisions in user space in general? I believe that the whole point of swdev is to provide *that* level of abstraction so decisions can be made in a vendor neutral way. > >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? I don't think anybody is saying that. P4 is likely a reality soon. But we definitely want hardware offload in a BPF world even if the hardware can't do BPF yet. > And why is OVS defining how BPF should evolve or how it should be used? Not sure I understand. OVS would be a user of eBPF just like tracing, xt_BPF, socket filter, ... > >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. As I said, this can be argued about. It would require to push a lot of context into the kernel though. The FDB offload is relatively trivial in comparison to the complexity OVS user space can handle. I can't think of any reasons why to complicate the kernel further with OVS specific knowledge as long as we can guarantee the vendor abstraction. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
