On Sep 20, 2014, at 5:51 AM, Roopa Prabhu <ro...@cumulusnetworks.com> wrote:
> On 9/20/14, 1:10 AM, Scott Feldman wrote: >> On Sep 19, 2014, at 8:41 PM, Roopa Prabhu <ro...@cumulusnetworks.com> >> wrote: >> >> >>> On 9/19/14, 8:49 AM, Jiri Pirko wrote: >>> >>>> Fri, Sep 19, 2014 at 05:25:48PM CEST, j...@mojatatu.com >>>> wrote: >>>> >>>>> On 09/19/14 09:49, Jiri Pirko wrote: >>>>> >>>>>> This patch exposes switchdev API using generic Netlink. >>>>>> Example userspace utility is here: >>>>>> >>>>>> https://github.com/jpirko/switchdev >>>>>> >>>>>> >>>>>> >>>>> Is this just a temporary test tool? Otherwise i dont see reason >>>>> for its existence (or the API that it feeds on). >>>>> >>>> Please read the conversation I had with Pravin and Jesse in v1 thread. >>>> Long story short they like to have the api separated from ovs datapath >>>> so ovs daemon can use it to directly communicate with driver. Also John >>>> Fastabend requested a way to work with driver flows without using ovs -> >>>> that was the original reason I created switchdev genl api. >>>> >>>> Regarding the "sw" tool, yes it is for testing purposes now. ovs daemon >>>> will use directly switchdev genl api. >>>> >>>> I hope I cleared this out. >>>> >>> We already have all the needed rtnetlink kernel api and userspace tools >>> around it to support all >>> switching asic features. ie, the rtnetlink api is the switchdev api. We can >>> do l2, l3, acl's with it. >>> Its unclear to me why we need another new netlink api. Which will mean none >>> of the existing tools to >>> create bridges etc will work on a switchdev. >>> Which seems like going in the direction exactly opposite to what we had >>> discussed earlier. >>> >> Existing rtnetlink isn’t available to swdev without some kind of snooping >> the echoes from the various kernel components (bridge, fib, etc). With >> swdev_flow, as Jiri has defined it, there is an additional conversion needed >> to bridge the gap (bad expression, I know) between rtnetlink and swdev_flow. >> This conversion happens in the kernel components. For example, the bridge >> module, still driven from userspace by existing rtnetlink, will formulate >> the necessary swdev_flow insert/remove calls to the swdev driver such that >> HW will offload the fwd path. >> >> You have: >> user -> rtnetlink -> kernel -> netlink echo -> [some process] -> [some >> driver] -> HW >> >> >> Jiri has: >> user -> rtnetlink -> kernel -> swdev_* -> swdev driver -> HW >> >> > Keeping the goal to not change or not add a new userspace API in mind, > I have : > user -> rtnetlink -> kernel -> ndo_op -> swdev driver -> HW > Then you have the same as Jiri, for the traditional L2/L3 case. > Jiri has: > user -> genl (newapi) -> kernel -> swdev_* -> swdev driver -> HW Jiri’s genl is for userspace apps that are talking rtnetlink, like OVS. It’s not a substitute for rtnetlink, it’s an alternative. The complete picture is: user -> swdev genl ----- \ \ -------> kernel -> ndo_swdev_* -> swdev driver -> HW / / user -> rtnetlink ------ -scott _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
