Re: [MAINTAINERS SUMMIT] Device Passthrough Considered Harmful?

Daniel Vetter
2024-08-06T07:14:24Z

On Thu, Aug 01, 2024 at 11:22:23AM -0300, Jason Gunthorpe wrote:
> On Tue, Jul 30, 2024 at 09:13:00AM +0200, Daniel Vetter wrote:
> > I think a solid consensus on the topics above would be really useful for
> > gpu/accel too. We're still busy with more pressing community/ecosystem
> > building needs, but gpu fw has become rather complex and it's not
> > stopping. And there's random other devices attached too nowadays, so fwctl
> > makes a ton of sense.
>
> Yeah, I'm pretty sure GPU is going to need fwctl too, the GPU's are
> going to have the same issues as NIC does. I see people are already
> struggling with topics like how to get debug traces out of the GPU FW.
>
> > But for me the more important stuff would be some clear guidelines like
> > what should be in other more across-devices subsystems like edac (or other
> > ras features), what should be in functional subsystems like netdev, rdma,
> > gpu/accel, ... whatever else, and what should be exposed through some
> > special purpose subsystems like hwmon.
>
> In my mind the most important part is that fwctl is not exclusive, the
> FW interface and things being manipulated must be sharable or blocked
> from fwctl. We should never get in a situation where a fwctl
> implementation becomes a reason we cannot have a functional subsystem
> interface.

Hm still not clear to me how you want to achive that, but I guess best
I'll jump over to the fwctl thread and ask about those details there.

> > We've got plenty of experience in enforcing such a community contract with
> > vendors, but the hard part is creating a clear and ideally concise
> > documentation page I can just point vendors at as the ground truth.
>
> Well, I tried with the documentation in the fwctl patch series..
>
> https://lore.kernel.org/linux-rdma/6-v2-940e479ceba9+3821-fwctl_jgg@nvidia.com/

I'll head over and drop some acks and comments.
-Sima
--
Daniel Vetter
Software Engineer, Intel Corporation