Re: [PATCH RFC] iommu/dma: Validate page before accessing P2PDMA state

[Jason Gunthorpe]

On Fri, Feb 27, 2026 at 02:08:42PM +0000, Pranjal Shrivastava wrote:

> The question is, are we sure to use scatterlists to represent non-paged
> memory? 

This is absolutely illegal and a driver bug to put non-struct page
memory into a scatter list. It was never an acceptable "work
around". What driver is doing this??

If you want to improve robustness add some pfn_valid/etc checks under
the CONFING DMA DEBUG and throw warns for these mistakes.

Jason