Nouveau - Oct 2025 - [PATCH 0/2] rust: pci: expose is_virtfn() and reject VFs in nova-core

On 2.10.2025 14.58, Jason Gunthorpe wrote:
> On Wed, Oct 01, 2025 at 09:13:33PM +0000, Zhi Wang wrote:
> 
>> Right, I also mentioned the same use cases of NIC/GPU in another reply
>> to Danilo. But what I get is NVIDIA doesn't use bare metal VF to
support
>> linux container, 
> 
> I don't think it matter what "NVIDIA" does - this is the
upstream
> architecture it should be followed unless there is some significant
> reason.
> 
Hmm. Can you elaborate why?

From the device vendor's stance, they know what is the best approach
to offer the better the user experience according to their device
characteristic. VF on bare metal is not the only approach for supporting
*container*. Some devices are using it because they have to rely on it
to deliver the user experience. It is mandatory for them because they
have to, not because of the architecture.

I am not sure why do the device vendor has to be forced on supporting
"VF on bare metal" if they have already offered the user a solution
via
other approach?

In fact, all the CSP I know, who are using GPU containers (not VM-based
containers) widely on cloud gaming, ML, they are using PF driver because
they are expecting high-density containers way more than amount of VFs the
GPU can offer.

I don't see the point of "VF on bare metal" is mandatory for GPU
containers,
at least, not right now.

Z.
> Jason

On Thu, Oct 02, 2025 at 12:59:59PM +0000, Zhi Wang
wrote:
> On 2.10.2025 14.58, Jason Gunthorpe wrote:
> > On Wed, Oct 01, 2025 at 09:13:33PM +0000, Zhi Wang wrote:
> > 
> >> Right, I also mentioned the same use cases of NIC/GPU in another
reply
> >> to Danilo. But what I get is NVIDIA doesn't use bare metal VF
to support
> >> linux container, 
> > 
> > I don't think it matter what "NVIDIA" does - this is the
upstream
> > architecture it should be followed unless there is some significant
> > reason.
> 
> Hmm. Can you elaborate why?
> 
> From the device vendor's stance, they know what is the best approach
> to offer the better the user experience according to their device
> characteristic.
You can easially push the code to nova core not vfio and make it work
generically, some significant reason is needed beyond "the vendor
doesn't want to".

Jason