Re: [PATCH 2/2] iommu/vt-d: Fix checks in pgtable_walk()

[Baolu Lu]

On 2024/10/23 13:16, Duan, Zhenzhong wrote:
> > -----Original Message-----
> > From: Baolu Lu<baolu.lu@xxxxxxxxxxxxxxx>
> > Sent: Wednesday, October 23, 2024 12:50 PM
> > Subject: Re: [PATCH 2/2] iommu/vt-d: Fix checks in pgtable_walk()
> >
> > On 2024/10/22 17:50, Zhenzhong Duan wrote:
> > > It's not accurate to dump super page as non-present page,
> > > meanwhile bit7 in first level page table entry is PAT bit,
> > Can you please explain how the 'bit7 in first level page table entry' is
> > relevant to the changes made in this patch?
> When iterate to level 1, it is leaf page table entry, bit 7 is PAT bit instead of PS bit.
> dma_pte_superpage(pte) may return true, then " PTE not present at level 1" may
> be printed out.

I see. Thank you!

If you have a new version, can you please make it a bit clearer? My
understanding is that dma_pte_superpage(pte) should not check against
the leaf page table entries, right?

Thanks,
baolu