Messages in this thread | | | Date | Thu, 11 Dec 2014 09:55:39 -0800 | From | John Fastabend <> | Subject | Re: [RFC PATCH net-next 1/1] net: Support for switch port configuration |
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On 12/11/2014 09:41 AM, Roopa Prabhu wrote: > 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.
I would prefer to _not_ add more attributes to ethtool. 'ethtool' is in general harder to work with then netlink for all but the most static attributes.
> > 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.
Absolutely I view this as an RFC patch noting we may/will need some extensions in the future. .We can evaluate the attributes on a case by case basis as they come in. And if they all fit in setlink/getlink that is great.
> >> >>> 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 >>> >>> >>> >
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