Messages in this thread | | | Date | Mon, 15 Dec 2014 08:18:44 -0800 | From | Roopa Prabhu <> | Subject | Re: [RFC PATCH net-next 1/1] net: Support for switch port configuration |
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On 12/15/14, 1:39 AM, Varlese, Marco wrote: >> -----Original Message----- >> From: Roopa Prabhu [mailto:roopa@cumulusnetworks.com] >> Sent: Saturday, December 13, 2014 7:06 AM >> To: Varlese, Marco >> Cc: Jiri Pirko; John Fastabend; netdev@vger.kernel.org; >> stephen@networkplumber.org; Fastabend, John R; sfeldma@gmail.com; >> linux-kernel@vger.kernel.org >> Subject: Re: [RFC PATCH net-next 1/1] net: Support for switch port >> configuration >> >> On 12/12/14, 1:19 AM, Varlese, Marco wrote: >>>> -----Original Message----- >>>> From: Roopa Prabhu [mailto:roopa@cumulusnetworks.com] >>>> Sent: Thursday, December 11, 2014 5:41 PM >>>> To: Jiri Pirko >>>> Cc: Varlese, Marco; John Fastabend; netdev@vger.kernel.org; >>>> stephen@networkplumber.org; Fastabend, John R; sfeldma@gmail.com; >>>> linux-kernel@vger.kernel.org >>>> Subject: Re: [RFC PATCH net-next 1/1] net: Support for switch port >>>> configuration >>>> >>>> On 12/11/14, 8:56 AM, Jiri Pirko wrote: >>>>> Thu, Dec 11, 2014 at 05:37:46PM CET, roopa@cumulusnetworks.com >> wrote: >>>>>> On 12/11/14, 3:01 AM, Jiri Pirko wrote: >>>>>>> Thu, Dec 11, 2014 at 10:59:42AM CET, marco.varlese@intel.com wrote: >>>>>>>>> -----Original Message----- >>>>>>>>> From: John Fastabend [mailto:john.fastabend@gmail.com] >>>>>>>>> Sent: Wednesday, December 10, 2014 5:04 PM >>>>>>>>> To: Jiri Pirko >>>>>>>>> Cc: Varlese, Marco; netdev@vger.kernel.org; >>>>>>>>> stephen@networkplumber.org; Fastabend, John R; >>>>>>>>> roopa@cumulusnetworks.com; sfeldma@gmail.com; linux- >>>>>>>>> kernel@vger.kernel.org >>>>>>>>> Subject: Re: [RFC PATCH net-next 1/1] net: Support for switch >>>>>>>>> port configuration >>>>>>>>> >>>>>>>>> On 12/10/2014 08:50 AM, Jiri Pirko wrote: >>>>>>>>>> Wed, Dec 10, 2014 at 05:23:40PM CET, marco.varlese@intel.com >>>> wrote: >>>>>>>>>>> From: Marco Varlese <marco.varlese@intel.com> >>>>>>>>>>> >>>>>>>>>>> Switch hardware offers a list of attributes that are >>>>>>>>>>> configurable on a per port basis. >>>>>>>>>>> This patch provides a mechanism to configure switch ports by >>>>>>>>>>> adding an NDO for setting specific values to specific attributes. >>>>>>>>>>> There will be a separate patch that extends iproute2 to call >>>>>>>>>>> the new NDO. >>>>>>>>>> What are these attributes? Can you give some examples. I'm >>>>>>>>>> asking because there is a plan to pass generic attributes to >>>>>>>>>> switch ports replacing current specific >>>>>>>>>> ndo_switch_port_stp_update. In this case, bridge is setting that >> attribute. >>>>>>>>>> Is there need to set something directly from userspace or does >>>>>>>>>> it make rather sense to use involved bridge/ovs/bond ? I think >>>>>>>>>> that both will be needed. >>>>>>>>> +1 >>>>>>>>> >>>>>>>>> I think for many attributes it would be best to have both. The >>>>>>>>> in kernel callers and netlink userspace can use the same driver >> ndo_ops. >>>>>>>>> But then we don't _require_ any specific bridge/ovs/etc module. >>>>>>>>> And we may have some attributes that are not specific to any >>>>>>>>> existing software module. I'm guessing Marco has some examples >>>>>>>>> of >>>> these. >>>>>>>>> [...] >>>>>>>>> >>>>>>>>> >>>>>>>>> -- >>>>>>>>> John Fastabend Intel Corporation >>>>>>>> We do have a need to configure the attributes directly from >>>>>>>> user-space >>>> and I have identified the tool to do that in iproute2. >>>>>>>> An example of attributes are: >>>>>>>> * enabling/disabling of learning of source addresses on a given >>>>>>>> port (you can imagine the attribute called LEARNING for example); >>>>>>>> * internal loopback control (i.e. LOOPBACK) which will control >>>>>>>> how the flow of traffic behaves from the switch fabric towards an >>>>>>>> egress port; >>>>>>>> * flooding for broadcast/multicast/unicast type of packets (i.e. >>>>>>>> BFLOODING, MFLOODING, UFLOODING); >>>>>>>> >>>>>>>> Some attributes would be of the type enabled/disabled while other >>>>>>>> will >>>> allow specific values to allow the user to configure different >>>> behaviours of that feature on that particular port on that platform. >>>>>>>> One thing to mention - as John stated as well - there might be >>>>>>>> some >>>> attributes that are not specific to any software module but rather >>>> have to do with the actual hardware/platform to configure. >>>>>>>> I hope this clarifies some points. >>>>>>> It does. Makes sense. We need to expose this attr set/get for both >>>>>>> in-kernel and userspace use cases. >>>>>>> >>>>>>> Please adjust you patch for this. Also, as a second patch, it >>>>>>> would be great if you can convert ndo_switch_port_stp_update to >>>>>>> this new >>>> ndo. >>>>>> Why are we exposing generic switch attribute get/set from userspace >>>>>> ?. We already have specific attributes for learning/flooding which >>>>>> can be extended further. >>>>> Yes, but that is for PF_BRIDGE and bridge specific attributes. There >>>>> might be another generic attrs, no? >>>> I cant think of any. And plus, the whole point of switchdev l2 >>>> offloads was to map these to existing bridge attributes. And we >>>> already have a match for some of the attributes that marco wants. >>>> >>>> If there is a need for such attributes, i don't see why it is needed >>>> for switch devices only. >>>> It is needed for any hw (nics etc). And, a precedence to this is to >>>> do it via ethtool. >>>> >>>> Having said that, am sure we will find a need for this in the future. >>>> And having a netlink attribute always helps. >>>> >>>> Today, it seems like these can be mapped to existing attributes that >>>> are settable via ndo_bridge_setlink/getlink. >>>> >>>>>> And for in kernel api....i had a sample patch in my RFC series >>>>>> (Which i was going to resubmit, until it was decided that we will >>>>>> use existing api around >>>>>> ndo_bridge_setlink/ndo_bridge_getlink): >>>>>> http://www.spinics.net/lists/netdev/msg305473.html >>>>> Yes, this might become handy for other generic non-bridge attrs. >>>>> >>>>>> Thanks, >>>>>> Roopa >>>>>> >>>>>> >>>>>> >>> The list I provided is only a subset of the attributes we will need to be >> exposed. I do have more and I'm sure that more will come in the future. As I >> mentioned in few posts earlier, some attributes are generic and some are >> not. >>> I did not consider ethtool for few reasons but the main one is that I was >> under the impression that netlink was preferred in many circumstances over >> the ethotool_ops. >> That is correct. I don't think anybody hinted that you should extend ethtool. >>> Plus, all the cases I have identified so far are going to nicely fit into the >> setlink set of operations. >> Would be better if you submitted your iproute2 patch with this patch. >> >> I do plan to resubmit my generic ndo patch soon. >> >> Thanks, >> Roopa > I honestly do not understand what extra "help" the iproute2 would have brought to this RFC: that patch simply adds a new section for the iproute2 help and a new args parser for the input. From an infrastructure perspective is leveraging what netlink messages are using RTM_SETLINK hence hooking up eventually in the do_setlink(). Sure, obviously contains all the attributes I have in mind but from an infrastructure patch perspective I don't think that you would have gained much in seeing it. correct. But you mentioned iproute2 changes in your patch comment. And since i was not getting a clear understanding of what these attributes were...from your current patch..., i thought your iproute2 patch might shed some light on how you plan to handle these attributes.
> > Anyway, good to know you're reworking you generic patch. I'll keep an eye out for your new NDO. > > > Thanks, > Marco >
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