linux-kernel - Re: [PATCH v4 3/3] vfio/type1: optimize vfio_unpin_pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250617094713.12501-1-lizhe.67@bytedance.com>
Date: Tue, 17 Jun 2025 17:47:13 +0800
From: lizhe.67@...edance.com
To: david@...hat.com
Cc: akpm@...ux-foundation.org,
	alex.williamson@...hat.com,
	kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	lizhe.67@...edance.com,
	peterx@...hat.com
Subject: Re: [PATCH v4 3/3] vfio/type1: optimize vfio_unpin_pages_remote() for large folio

On Tue, 17 Jun 2025 09:43:56 +0200, david@...hat.com wrote:
 
> > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> > index e952bf8bdfab..d7653f4c10d5 100644
> > --- a/drivers/vfio/vfio_iommu_type1.c
> > +++ b/drivers/vfio/vfio_iommu_type1.c
> > @@ -801,16 +801,43 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
> >          return pinned;
> >   }
> >   
> > +/* Returned number includes the provided current page. */
> > +static inline unsigned long folio_remaining_pages(struct folio *folio,
> > +               struct page *page, unsigned long max_pages)
> > +{
> > +       if (!folio_test_large(folio))
> > +               return 1;
> > +       return min_t(unsigned long, max_pages,
> > +                    folio_nr_pages(folio) - folio_page_idx(folio, page));
> > +}
> 
> Note that I think that should go somewhere into mm.h, and also get used 
> by GUP. So factoring it out from GUP and then using it here.

I think I need to separate this out into a distinct patch within the
patchset. Is that correct?

Thanks,
Zhe