Re: [PATCH net-next v2 0/3] VGT+ support

From: Saeed Mahameed <saeedm@mellanox.com>
To: "jakub.kicinski@netronome.com" <jakub.kicinski@netronome.com>
Cc: "sbrivio@redhat.com" <sbrivio@redhat.com>,
	"nikolay@cumulusnetworks.com" <nikolay@cumulusnetworks.com>,
	"dsahern@gmail.com" <dsahern@gmail.com>,
	"sd@queasysnail.net" <sd@queasysnail.net>,
	Jiri Pirko <jiri@mellanox.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"stephen@networkplumber.org" <stephen@networkplumber.org>,
	Ariel Levkovich <lariel@mellanox.com>
Subject: Re: [PATCH net-next v2 0/3] VGT+ support
Date: Wed, 6 Nov 2019 22:21:37 +0000	[thread overview]
Message-ID: <c5bedde710b0667fd44213d8c64e65f6870a2f07.camel@mellanox.com> (raw)
In-Reply-To: <20191105173841.43836ad7@cakuba.netronome.com>

On Tue, 2019-11-05 at 17:38 -0800, Jakub Kicinski wrote:
> On Tue, 5 Nov 2019 23:48:15 +0000, Saeed Mahameed wrote:
> > On Tue, 2019-11-05 at 15:10 -0800, Jakub Kicinski wrote:
> > > But switchdev _is_ _here_. _Today_. From uAPI perspective it's
> > > done,
> > > and ready. We're missing the driver and user space parts, but no
> > > core
> > > and uAPI extensions. It's just L2 switching and there's quite a
> > > few
> > > switch drivers upstream, as I'm sure you know :/ 
> > 
> > I can say the same about netlink, it also was there, the missing
> > part
> > was the netlink ethtool connection and userspace parts .. 
> 
> uAPI is the part that matters. No driver implements all the APIs. 
> I'm telling you that the API for what you're trying to configure
> already exists, and your driver should use it. Driver's technical 
> debt is not my concern.
> 
> > Just because switchdev uAPI is powerful enough to do anything it
> > doesn't mean we are ready, you said it, user space and drivers are
> > not
> > ready, and frankly it is not on the road map, 
> 
> I bet it's not on the road map. Product marketing sees only legacy
> SR-IOV (table stakes) and OvS offload == switchdev (value add). 
> L2 switchdev will never be implemented with that mind set.
> 
> In the upstream community, however, we care about the technical
> aspects.
> 
> > and we all know that it could take years before we can sit back and
> > relax that we got our L2 switching .. 
> 
> Let's not be dramatic. It shouldn't take years to implement basic L2
> switching offload.
> 
> > Just like what is happening now with ethtool, it been years you
> > know..
> 
> Exactly my point!!! Nobody is going to lift a finger unless there is
> a
> loud and resounding "no".
> 

Ok then, "no" new uAPI, although i still think there should be some
special cases to be allowed, but ... your call.

In the meanwhile i will figure out something to be driver only as
intermediate solution until we have full l2 offload, then i can ask
every one to move to full switchdev mode with a press of a button.