On Mon, Oct 21, 2024 at 12:32:21PM +0100, Steven Price wrote: > > that, we can always do it in two steps (unmap the 2M region and remap > > the borders). At some point it'd be good to have some kind of atomic > > page table updates, so we don't have this short period of time during > > which nothing is mapped (between the unmap and the remap), but that's a > > different story. > > The GPU hardware provides that. The only possible missing piece is that > the driver needs to know ahead of time that the unmap would unmap the 2M > region so it can do the correct lock before the entries are removed. It looks like we need atomic update for some confidential compute scenarios, so I am working toward that with the coming generic pt stuff. > >> If DRM does use this, I'd respin this to make it into a quirk and iommu won't > >> set it. > > You should be safe as far as Panfrost and Panthor are concerned. Great, thanks! Jason
