[PATCH v3 0/2] arm64: ptdump flush fixes

[Wei-Lin Chang]

Hi,

This series fixes two problems around ptdumps:

1. note_page_flush(), which flushes out the last row of ptdumps, does
   not account for address spaces that have IA < 64. Other than making
   the last region extremely huge, the attributes of the last region
   within the address spaces appear to extend all the way to 1 << 64.

2. KVM/arm64's stage-2 ptdump missed calling note_page_flush().

To address Will's comment [1], I have created an end_address field for
struct ptdump_pg_state, and initialized it with the end address of the
ptdumps. It follows the same convention as the last range->end:
exclusive end, except for the case where the address space ends at
1 << 64. In that case it is set as ULONG_MAX.

Caching the end address avoids duplicating the range iteration in
note_page_flush(), at the cost of duplicating state in ptdump_pg_state.

Series is based on v7.2-rc5.

* Changes from v2:

  - Instead of scanning ptdump_state.range[] to find the end address,
    cache the end address in a new field end_address when we initialize
    struct ptdump_pg_state.

  - Adjust KVM's struct ptdump_pg_state initialization so it uses
    end_address instead of ptdump_state.range[].

  - Collected Reviewed-by and Tested-by from Dev, thanks!

  - v2: https://lore.kernel.org/r/20260724185431.2990395-1-weilin.chang@arm.com/

* Changes from v1:

  - Instead of manually calling note_page() for flushing, fix
    note_page_flush() so that it ends the ptdump at the end of the
    address space.

  - Changed the start address of the second marker to ULONG_MAX for KVM
    ptdump, so we don't output extra marker names, and advance past the
    end of the marker array.

  - v1: https://lore.kernel.org/r/20260717231233.2299068-1-weilin.chang@arm.com/

Thanks!

[1]: https://lore.kernel.org/r/anXFo-igVdqrCogQ@willie-the-truck/

Wei-Lin Chang (2):
  arm64: ptdump: Make note_page_flush() range aware
  KVM: arm64: ptdump: Flush the last region

 arch/arm64/include/asm/ptdump.h |  2 ++
 arch/arm64/kvm/ptdump.c         | 11 +++++++----
 arch/arm64/mm/ptdump.c          | 14 +++++++++++++-
 3 files changed, 22 insertions(+), 5 deletions(-)

-- 
2.43.0