Subject: Re: [RFC PATCH net-next 08/19] pds_core: initial VF configuration

From: Jakub Kicinski <[email-masked]>
Date: Thu, 1 Dec 2022 14:29:51 -0800

On Thu, 1 Dec 2022 11:19:51 -0800 Shannon Nelson wrote:
> > It simply does not compute for me. You're exposing a very advanced vDPA
> > interface, and yet you say you don't need any network configuration
> > beyond what Niantic had.  
> 
> Would you have the same responses if we were trying to do this same kind 
> of PF netdev on a simple Niantic-like device (simple sr-iov support, 
> little filtering capability)?

It is really hard for me to imagine someone building a Niantic-like
device today.

Recently I was thought-experiment-designing simplest Niantic-like device
for container workloads. And my conclusion was that yes, TC would
probably be the best way to control forwarding. (Sorry not really an
answer to your question, I don't know of any real Niantics of the day)

> > There are no upstream-minded users of IPUs, if it was up to me I'd flat
> > out ban them from the kernel.  
> 
> Yeah, there's a lot of hidden magic going on behind the PCI devices 
> presented to the host, and a lot of it depends on the use cases 
> attempting to be addressed by the different product vendors and their 
> various cloud and enterprise customers.  I tend to think that the most 
> friction here comes from us being more familiar and comfortable with the 
> enterprise use cases where we typically own the whole host, and not so 
> comfortable these newer cloud use cases with control and configuration 
> coming from outside the host.

I know about cloud as much as I know about enterprise, being a Meta's
employee. But those who do have public clouds seem to develop all the
meaningful tech behind closed doors, under NDAs. And at best "bless" 
us with a code dump which is under an open source license.

The community is where various developers should come together and
design together. If you do a full design internally and then come
upstream to just ship the code then it's a SW distribution channel,
not an open source project. That's what I am not comfortable with.