[PATCHv2 00/10] Boot-time switching between 4- and 5-level paging

[Kirill A. Shutemov]

[ This patchset is on top my previous 5-level paging patchset[1] ]

The basic idea is to implement the same logic as pgtable-nop4d.h provides,
but at runtime.

Runtime folding is only implemented for CONFIG_X86_5LEVEL=y case. With the
option disabled, we do compile-time folding as before..

Initially, I tried to fold pgd instread. I've got to shell, but it
required a lot of hacks as kernel threats pgd in a special way.

Comparing to RFC patchset, I've dealt with hacks and performance should be
fine now.

Please review and consider applying.

[1] http://lkml.kernel.org/r/20170716225954.74185-1-kirill.shutemov@xxxxxxxxxxxxxxx

Kirill A. Shutemov (10):
  x86/kasan: Use the same shadow offset for 4- and 5-level paging
  x86/xen: Provide pre-built page tables only for XEN_PV and XEN_PVH
  x86/boot/compressed/64: Detect and handle 5-level paging at boot-time
  x86/mm: Make virtual memory layout movable for CONFIG_X86_5LEVEL
  x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable
  x86/mm: Handle boot-time paging mode switching at early boot
  x86/mm: Fold p4d page table layer at runtime
  x86/mm: Replace compile-time checks for 5-level with runtime-time
  x86/mm: Allow to boot without la57 if CONFIG_X86_5LEVEL=y
  x86/mm: Offset boot-time paging mode switching cost

 Documentation/x86/x86_64/5level-paging.txt |  9 +--
 arch/x86/Kconfig                           |  5 +-
 arch/x86/boot/compressed/head_64.S         | 24 ++++++++
 arch/x86/boot/compressed/kaslr.c           | 14 +++++
 arch/x86/boot/compressed/misc.h            |  5 ++
 arch/x86/entry/entry_64.S                  | 12 ++++
 arch/x86/include/asm/kaslr.h               |  4 --
 arch/x86/include/asm/page_64.h             |  4 ++
 arch/x86/include/asm/page_64_types.h       | 15 ++---
 arch/x86/include/asm/paravirt.h            |  8 +--
 arch/x86/include/asm/pgalloc.h             |  5 +-
 arch/x86/include/asm/pgtable.h             | 10 +++-
 arch/x86/include/asm/pgtable_32.h          |  2 +
 arch/x86/include/asm/pgtable_32_types.h    |  2 +
 arch/x86/include/asm/pgtable_64_types.h    | 53 ++++++++++++-----
 arch/x86/include/asm/pgtable_types.h       | 67 +++++----------------
 arch/x86/include/asm/processor.h           |  2 +-
 arch/x86/include/asm/required-features.h   |  8 +--
 arch/x86/include/asm/sparsemem.h           | 12 ++--
 arch/x86/kernel/Makefile                   |  3 +-
 arch/x86/kernel/head64.c                   | 71 +++++++++++++++++++---
 arch/x86/kernel/head_64.S                  | 29 +++++----
 arch/x86/mm/dump_pagetables.c              | 20 ++++---
 arch/x86/mm/fault.c                        |  2 +-
 arch/x86/mm/ident_map.c                    |  2 +-
 arch/x86/mm/init_64.c                      | 32 +++++-----
 arch/x86/mm/kasan_init_64.c                | 94 +++++++++++++++++++++++-------
 arch/x86/mm/kaslr.c                        | 27 ++++-----
 arch/x86/platform/efi/efi_64.c             |  6 +-
 arch/x86/power/hibernate_64.c              |  6 +-
 arch/x86/xen/mmu_pv.c                      |  2 +-
 include/asm-generic/5level-fixup.h         |  1 +
 include/asm-generic/pgtable-nop4d.h        |  1 +
 include/linux/kasan.h                      |  2 +-
 mm/kasan/kasan_init.c                      |  2 +-
 35 files changed, 363 insertions(+), 198 deletions(-)

-- 
2.11.0