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

[Zhi Wang <zhiw@nvidia.com>]

On 7.10.2025 13.14, Danilo Krummrich wrote:
> On Tue Oct 7, 2025 at 8:51 AM CEST, Zhi Wang wrote:
>> From the device vendor’s perspective, we have no support or use case for
>> a bare-metal VF model, not now and not in the foreseeable future.
> 
> Who is we? I think there'd be a ton of users that do see such use-cases.
> 
> What does "no support" mean? Are there technical limitation that prevent an> implementation (I haven't seen any so far)?
> 
>> Even
>> hypothetically, such support would not come from nova-core.ko, since
>> that would defeat the purpose of maintaining a trimmed-down kernel
>> module where minimizing the attack surface and preserving strict
>> security boundaries are primary design goals.
> 
> I wouldn't say the *primary* design goal is to be as trimmed-down as possible.
> 
> The primary design goals are rather proper firmware abstraction, addressing
> design incompatibilities with modern graphics and compute APIs, memory safety
> concerns and general maintainability.
> 
> It does make sense to not run the vGPU use-case on top of all the additional DRM
> stuff that will go into nova-drm, since this is clearly not needed in the vGPU
> use-case. But, it doesn't mean that we have to keep everything out of nova-core
> for this purpose.
> 
> I think the bare-metal VF model is a very interesting use-case and if it is
> technically feasable we should support it. And I think it should be in
> nova-core. The difference between nova-core running on a bare metal VF and
> nova-core running on the same VF in a VM shouldn't be that different anyways,
> no?

@Neo. Can you shed some light here?