RE: [RFC PATCH net-next 1/1] net: Support for switch port configuration

[Varlese, Marco]

> -----Original Message-----
> From: Jiri Pirko [mailto:jiri@xxxxxxxxxxx]
> Sent: Thursday, December 11, 2014 11:01 AM
> To: Varlese, Marco
> Cc: John Fastabend; netdev@xxxxxxxxxxxxxxx;
> stephen@xxxxxxxxxxxxxxxxxx; Fastabend, John R;
> roopa@xxxxxxxxxxxxxxxxxxx; sfeldma@xxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [RFC PATCH net-next 1/1] net: Support for switch port
> configuration
> 
> Thu, Dec 11, 2014 at 10:59:42AM CET, marco.varlese@xxxxxxxxx wrote:
> >> -----Original Message-----
> >> From: John Fastabend [mailto:john.fastabend@xxxxxxxxx]
> >> Sent: Wednesday, December 10, 2014 5:04 PM
> >> To: Jiri Pirko
> >> Cc: Varlese, Marco; netdev@xxxxxxxxxxxxxxx;
> >> stephen@xxxxxxxxxxxxxxxxxx; Fastabend, John R;
> >> roopa@xxxxxxxxxxxxxxxxxxx; sfeldma@xxxxxxxxx; linux-
> >> kernel@xxxxxxxxxxxxxxx
> >> 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@xxxxxxxxx wrote:
> >> >> From: Marco Varlese <marco.varlese@xxxxxxxxx>
> >> >>
> >> >> 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.
> 
> Thanks.
> 
> 

I was thinking of leaving the get side of things implemented via sysfs rather than implementing an NDO for it. Would this not be appropriate?

- - -
Marco Varlese

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