Merge branch kvm-arm64/mte-map-shared into kvmarm-master/next

* kvm-arm64/mte-map-shared:
  : .
  : Update the MTE support to allow the VMM to use shared mappings
  : to back the memslots exposed to MTE-enabled guests.
  :
  : Patches courtesy of Catalin Marinas and Peter Collingbourne.
  : .
  : Fix a number of issues with MTE, such as races on the tags
  : being initialised vs the PG_mte_tagged flag as well as the
  : lack of support for VM_SHARED when KVM is involved.
  :
  : Patches from Catalin Marinas and Peter Collingbourne.
  : .
  Documentation: document the ABI changes for KVM_CAP_ARM_MTE
  KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
  KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
  arm64: mte: Lock a page for MTE tag initialisation
  mm: Add PG_arch_3 page flag
  KVM: arm64: Simplify the sanitise_mte_tags() logic
  arm64: mte: Fix/clarify the PG_mte_tagged semantics
  mm: Do not enable PG_arch_2 for all 64-bit architectures

Signed-off-by: Marc Zyngier <maz@kernel.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 3e9cf9826417..0b1c102b89c9 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -937,6 +937,8 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
 
 void tag_clear_highpage(struct page *page)
 {
+	/* Newly allocated page, shouldn't have been tagged yet */
+	WARN_ON_ONCE(!try_page_mte_tagging(page));
 	mte_zero_clear_page_tags(page_address(page));
-	set_bit(PG_mte_tagged, &page->flags);
+	set_page_mte_tagged(page);
 }