Re: [PATCH v1 0/4] mm: Implement ECC handling for pfn with no struct page

From: Jason Gunthorpe
Date: Wed Sep 20 2023 - 12:04:34 EST


On Wed, Sep 20, 2023 at 09:02:22AM -0700, Andrew Morton wrote:
> On Wed, 20 Sep 2023 19:32:06 +0530 <ankita@xxxxxxxxxx> wrote:
>
> > The kernel MM currently handles ECC errors / poison only on memory page
> > backed by struct page. As part of [1], the nvgrace-gpu-vfio-pci module
> > maps the device memory to user VA (Qemu) using remap_pfn_range without
> > being added to the kernel. These pages are not backed by struct page.
>
> Are you able to identify any other drivers which can (or will) use
> this? Or is it likely that this feature will only ever be for
> nvgrace-gpu-vfio-pci?

I think a future vfio-cxl will have a similar desire at least.

Jason