From fcd6dbac9267c1c06a205ad8bb4bd027c0ace7f7 Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@qumranet.com>
Date: Thu, 3 Apr 2008 12:02:21 +0300
Subject: [PATCH] KVM: MMU: Only mark_page_accessed() if the page was accessed
 by the guest

If the accessed bit is not set, the guest has never accessed this page
(at least through this spte), so there's no need to mark the page
accessed.  This provides more accurate data for the eviction algortithm.

Noted by Andrea Arcangeli.

Signed-off-by: Avi Kivity <avi@qumranet.com>
---
 arch/x86/kvm/mmu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1594ee06c920..5c4c16662c68 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -549,7 +549,8 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
 		return;
 	sp = page_header(__pa(spte));
 	page = spte_to_page(*spte);
-	mark_page_accessed(page);
+	if (*spte & PT_ACCESSED_MASK)
+		mark_page_accessed(page);
 	if (is_writeble_pte(*spte))
 		kvm_release_page_dirty(page);
 	else