Re: [PATCH v8 2/3] vfio/ism: Implement vfio_pci driver for ISM devices

[Jason Gunthorpe]

On Mon, Mar 30, 2026 at 12:39:25PM -0600, Alex Williamson wrote:
> Yes, that would be the ideal balance of enabling larger BARs while
> retaining compatibility for existing devices.  Sounds like we'll
> continue down the variant driver path for this one-off device for
> now.  It remains fairly self contained so long as we don't add more
> regions for vfio-pci-core to manage.
> 
> This could be a good project if someone is looking though, especially
> if it had a build-time config option to set the minimum region size so
> we can exercise it before we hit 1TB BARs.  Thanks,

Well, it took claude an hour to vibe code a draft from a four sentence
prompt.. I see many things that need changing/cleaning in here, but
the patch strategy and general idea looks sound.

I guess another day of effort would probably get things into something
presentable. We are not so far away - maybe the variant driver path is
not necessary?

https://github.com/jgunthorpe/linux/commits/vfio_maple_tree/

Jason