From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751906AbaLRXH0 (ORCPT ); Thu, 18 Dec 2014 18:07:26 -0500 Received: from ext3.cumulusnetworks.com ([198.211.106.187]:52126 "EHLO ext3.cumulusnetworks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751830AbaLRXHZ (ORCPT ); Thu, 18 Dec 2014 18:07:25 -0500 Message-ID: <54935E28.8050602@cumulusnetworks.com> Date: Thu, 18 Dec 2014 15:07:20 -0800 From: Roopa Prabhu User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: John Fastabend CC: "Varlese, Marco" , "netdev@vger.kernel.org" , Thomas Graf , Jiri Pirko , "sfeldma@gmail.com" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH net-next v2 1/1] net: Support for switch port configuration References: <5492E85C.6010802@cumulusnetworks.com> <5492EFC3.8030102@cumulusnetworks.com> <549313B8.6050102@cumulusnetworks.com> <54931969.7040209@cumulusnetworks.com> <5493293A.2000802@intel.com> In-Reply-To: <5493293A.2000802@intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/18/14, 11:21 AM, John Fastabend wrote: > On 12/18/2014 10:14 AM, Roopa Prabhu wrote: >> On 12/18/14, 10:02 AM, Varlese, Marco wrote: >>> Removed unnecessary content for ease of reading... >>> >>>>>>>>> +/* Switch Port Attributes section */ >>>>>>>>> + >>>>>>>>> +enum { >>>>>>>>> + IFLA_ATTR_UNSPEC, >>>>>>>>> + IFLA_ATTR_LEARNING, >>>>>>>> Any reason you want learning here ?. This is covered as part of >>>>>>>> the bridge setlink attributes. >>>>>>>> >>>>>>> Yes, because the user may _not_ want to go through a bridge >>>>>>> interface >>>>>> necessarily. >>>>>> But, the bridge setlink/getlink interface was changed to accommodate >>>> 'self' >>>>>> for exactly such cases. >>>>>> I kind of understand your case for the other attributes (these are >>>>>> per port settings that switch asics provide). >>>>>> >>>>>> However, i don't understand the reason to pull in bridge attributes here. >>>>>> >>>>> Maybe, I am missing something so you might help. The learning attribute - >>>> in my case - it is like all other attributes: a port attribute (as you said, port >>>> settings that the switch provides per port). >>>>> So, what I was saying is "why the user shall go through a bridge to configure >>>> the learning attribute"? From my perspective, it is as any other attribute and >>>> as such configurable on the port. >>>> >>>> Thinking about this some more, i don't see why any of these attributes >>>> (except loopback. I dont understand the loopback attribute) cant be part of >>>> the birdge port attributes. >>>> >>>> With this we will end up adding l2 attributes in two places: the general link >>>> attributes and bridge attributes. >>>> >>>> And since we have gone down the path of using ndo_bridge_setlink/getlink >>>> with 'self'....we should stick to that for all l2 attributes. >>>> >>>> The idea of overloading ndo_bridge_set/getlink, was to have the same set of >>>> attributes but support both cases where the user wants to go through the >>>> bridge driver or directly to the switch port driver. So, you are not really going >>>> through the bridge driver if you use 'self' and ndo_bridge_setlink/getlink. >>>> >>> Roopa, one of the comments I got from Thomas Graf on my v1 patch >>> was that your patch and mine were supplementary ("I think Roopa's >>> patches are supplementary. Not all switchdev users will be backed >>> with a Linux Bridge. I therefore welcome your patches very >>> much")... I also understood by others that the patch made sense for >>> the same reason. I simply do not understand why these attributes >>> (and maybe others in the future) could not be configured directly >>> on a standard port but have to go through a bridge. >>> >> ok, i am very confused in that case. The whole moving of bridge >> attributes from the bridge driver to rtnetlink.c was to make the >> bridge attributes accessible to any driver who wants to set l2/bridge >> attributes on their switch ports. So, its unclear to me why we are >> doing this parallel thing again. This move to rtnetlink.c was done >> during the recent rocker support. so, maybe scott/jiri can elaborate >> more. > > Not sure if this will add to the confusion or help. But you do not > need to have the bridge.ko loaded or netdev's attached to a bridge > to use the setlink/getlink ndo ops and netlink messages. > > This was intentionally done. Its already used with NIC devices to > configure embedded bridge settings such as VEB/VEPA. that helps my case, thanks. > > I think I'm just repeating Roopa though. >