[PATCH 06/15] KVM: x86/mmu: Implement PWALK_SET_ACCESSED in page walker

[Nikolas Wipper]

Implement PWALK_SET_ACCESSED in the page walker. This flag allows
controling whether the page walker will set the accessed bits after a
successful page walk in all page table levels. If the page walk is aborted
for any reason, none of the access bits are set.

Signed-off-by: Nikolas Wipper <nikwip at amazon.de>
---
 arch/x86/kvm/mmu/paging_tmpl.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index c278b83b023f..eed6e2c653ba 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -317,6 +317,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
 	const int write_fault = access & PFERR_WRITE_MASK;
 	const int user_fault  = access & PFERR_USER_MASK;
 	const int fetch_fault = access & PFERR_FETCH_MASK;
+	const int set_accessed = flags & PWALK_SET_ACCESSED;
 	u16 errcode = 0;
 	gpa_t real_gpa;
 	gfn_t gfn;
@@ -468,7 +469,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
 		accessed_dirty &= pte >>
 			(PT_GUEST_DIRTY_SHIFT - PT_GUEST_ACCESSED_SHIFT);
 
-	if (unlikely(!accessed_dirty)) {
+	if (unlikely(set_accessed && !accessed_dirty)) {
 		ret = FNAME(update_accessed_dirty_bits)(vcpu, mmu, walker, addr,
 							write_fault);
 		if (unlikely(ret < 0))
-- 
2.40.1




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