[0/3] A Solution to Re-enable hugetlb vmemmap optimize on Arm

Message

Nanyong Sun Dec. 14, 2023, 7:39 a.m. UTC

HVO was previously disabled on arm64 [1] due to the lack of necessary
BBM(break-before-make) logic when changing page tables.
This set of patches fix this by adding necessary BBM sequence when
changing page table, and supporting vmemmap page fault handling to
fixup kernel address fault if vmemmap is concurrently accessed.

[1] commit 060a2c92d1b6 ("arm64: mm: hugetlb: Disable HUGETLB_PAGE_OPTIMIZE_VMEMMAP")

Nanyong Sun (3):
  mm: HVO: introduce helper function to update and flush pgtable
  arm64: mm: HVO: support BBM of vmemmap pgtable safely
  arm64: mm: Re-enable OPTIMIZE_HUGETLB_VMEMMAP

 arch/arm64/Kconfig           |  1 +
 arch/arm64/include/asm/esr.h |  4 ++
 arch/arm64/include/asm/mmu.h | 20 ++++++++
 arch/arm64/mm/fault.c        | 94 ++++++++++++++++++++++++++++++++++++
 arch/arm64/mm/mmu.c          | 28 +++++++++++
 mm/hugetlb_vmemmap.c         | 55 ++++++++++++++++-----
 6 files changed, 190 insertions(+), 12 deletions(-)