[PATCH v4 0/2] kvm: Use huge pages for DAX-backed files

From: Barret Rhoden
Date: Wed Dec 11 2019 - 16:32:24 EST

This patchset allows KVM to map huge pages for DAX-backed files.

I held previous versions in limbo while people were sorting out whether
or not DAX pages were going to remain PageReserved and how that relates
to KVM.

Now that that is sorted out (DAX pages are PageReserved, but they are
not kvm_is_reserved_pfn(), and DAX pages are considered on a
case-by-case basis for KVM), I can repost this.

v3 -> v4:
v3: https://lore.kernel.org/lkml/20190404202345.133553-1-brho@xxxxxxxxxx/
- Rebased onto linus/master

v2 -> v3:
v2: https://lore.kernel.org/lkml/20181114215155.259978-1-brho@xxxxxxxxxx/
- Updated Acks/Reviewed-by
- Rebased onto linux-next

v1 -> v2:
- Updated Acks/Reviewed-by
- Minor touchups
- Added patch to remove redundant PageReserved() check
- Rebased onto linux-next

RFC/discussion thread:

Barret Rhoden (2):
mm: make dev_pagemap_mapping_shift() externally visible
kvm: Use huge pages for DAX-backed files

arch/x86/kvm/mmu/mmu.c | 36 ++++++++++++++++++++++++++++++++----
include/linux/mm.h | 3 +++
mm/memory-failure.c | 38 +++-----------------------------------
mm/util.c | 34 ++++++++++++++++++++++++++++++++++
4 files changed, 72 insertions(+), 39 deletions(-)