Re: [RFC 00/29] Introduce NVIDIA GPU Virtualization (vGPU) Support

[Danilo Krummrich <dakr@kernel.org>]

On Mon, Sep 23, 2024 at 12:01:40PM -0300, Jason Gunthorpe wrote:
> On Mon, Sep 23, 2024 at 10:49:07AM +0200, Danilo Krummrich wrote:
> > > 2. Proposal for upstream
> > > ========================
> > 
> > What is the strategy in the mid / long term with this?
> > 
> > As you know, we're trying to move to Nova and the blockers with the device /
> > driver infrastructure have been resolved and we're able to move forward. Besides
> > that, Dave made great progress on the firmware abstraction side of things.
> > 
> > Is this more of a proof of concept? Do you plan to work on Nova in general and
> > vGPU support for Nova?
> 
> This is intended to be a real product that customers would use, it is
> not a proof of concept. There is alot of demand for this kind of
> simplified virtualization infrastructure in the host side.

I see...

> The series
> here is the first attempt at making thin host infrastructure and
> Zhi/etc are doing it with an upstream-first approach.

This is great!

> 
> From the VFIO side I would like to see something like this merged in
> nearish future as it would bring a previously out of tree approach to
> be fully intree using our modern infrastructure. This is a big win for
> the VFIO world.
> 
> As a commercial product this will be backported extensively to many
> old kernels and that is harder/impossible if it isn't exclusively in
> C. So, I think nova needs to co-exist in some way.

We'll surely not support two drivers for the same thing in the long term,
neither does it make sense, nor is it sustainable.

We have a lot of good reasons why we decided to move forward with Nova as a
successor of Nouveau for GSP-based GPUs in the long term -- I also just held a
talk about this at LPC.

For the short/mid term I think it may be reasonable to start with Nouveau, but
this must be based on some agreements, for instance:

- take responsibility, e.g. commitment to help with maintainance with some of
  NVKM / NVIDIA GPU core (or whatever we want to call it) within Nouveau
- commitment to help with Nova in general and, once applicable, move the vGPU
  parts over to Nova

But I think the very last one naturally happens if we stop further support for
new HW in Nouveau at some point.

> 
> Jason
>