[v4,0/4] hugetlb: Disable huge pmd unshare for uffd-wp

Message

Peter Xu Feb. 18, 2021, 11:06 p.m. UTC

v4:
- fix build for sparc by removing extra line in patch 1 [Mike]
- pick Mike's r-b for patch 4

v3:
- patch 4:
  - fix build failure for !CMA and/or !HUGETLBFS [Axel]
  - Fix mmu notifier range to use start/end [Mike]
- add more r-bs

v2:
- patch 4: move hugetlb_unshare_all_pmds() into mm/hugetlb.c, so it can be used
  even outside userfaultfd.c

This series tries to disable huge pmd unshare of hugetlbfs backed memory for
uffd-wp.  Although uffd-wp of hugetlbfs is still during rfc stage, the idea of
this series may be needed for multiple tasks (Axel's uffd minor fault series,
and Mike's soft dirty series), so I picked it out from the larger series.

References works:

Uffd shmem+hugetlbfs rfc:
https://lore.kernel.org/lkml/[e-mail]/

Uffd minor mode for hugetlbfs:
https://lore.kernel.org/lkml/[e-mail]/

Soft dirty for hugetlbfs:
https://lore.kernel.org/lkml/[e-mail]/

Please review, thanks.

Peter Xu (4):
  hugetlb: Pass vma into huge_pte_alloc() and huge_pmd_share()
  hugetlb/userfaultfd: Forbid huge pmd sharing when uffd enabled
  mm/hugetlb: Move flush_hugetlb_tlb_range() into hugetlb.h
  hugetlb/userfaultfd: Unshare all pmds for hugetlbfs when register wp

 arch/arm64/mm/hugetlbpage.c   |  7 ++-
 arch/ia64/mm/hugetlbpage.c    |  3 +-
 arch/mips/mm/hugetlbpage.c    |  4 +-
 arch/parisc/mm/hugetlbpage.c  |  2 +-
 arch/powerpc/mm/hugetlbpage.c |  3 +-
 arch/s390/mm/hugetlbpage.c    |  2 +-
 arch/sh/mm/hugetlbpage.c      |  2 +-
 arch/sparc/mm/hugetlbpage.c   |  2 +-
 fs/userfaultfd.c              |  4 ++
 include/linux/hugetlb.h       | 18 ++++++-
 include/linux/userfaultfd_k.h |  9 ++++
 mm/hugetlb.c                  | 94 +++++++++++++++++++++++++++--------
 mm/userfaultfd.c              |  2 +-
 13 files changed, 116 insertions(+), 36 deletions(-)

Comments

Peter Xu March 1, 2021, 2:20 p.m. UTC | #1

On Thu, Feb 18, 2021 at 06:06:29PM -0500, Peter Xu wrote:
> v4:
> - fix build for sparc by removing extra line in patch 1 [Mike]
> - pick Mike's r-b for patch 4
> 
> v3:
> - patch 4:
>   - fix build failure for !CMA and/or !HUGETLBFS [Axel]
>   - Fix mmu notifier range to use start/end [Mike]
> - add more r-bs
> 
> v2:
> - patch 4: move hugetlb_unshare_all_pmds() into mm/hugetlb.c, so it can be used
>   even outside userfaultfd.c
> 
> This series tries to disable huge pmd unshare of hugetlbfs backed memory for
> uffd-wp.  Although uffd-wp of hugetlbfs is still during rfc stage, the idea of
> this series may be needed for multiple tasks (Axel's uffd minor fault series,
> and Mike's soft dirty series), so I picked it out from the larger series.
> 
> References works:
> 
> Uffd shmem+hugetlbfs rfc:
> https://lore.kernel.org/lkml/[e-mail]/
> 
> Uffd minor mode for hugetlbfs:
> https://lore.kernel.org/lkml/[e-mail]/
> 
> Soft dirty for hugetlbfs:
> https://lore.kernel.org/lkml/[e-mail]/

Andrew/Mike,

Do you have any further comment on this series?

Thanks,