From 383fc794e9cbbc9d135436b7b7287a047a84c283 Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Fri, 16 Jul 2010 11:30:18 +0800
Subject: [PATCH] --- yaml --- r: 202426 b: refs/heads/master c:
 9a3aad70572c3f4d55e7f09ac4eb313d41d0a484 h: refs/heads/master v: v3

---
 [refs]                   | 2 +-
 trunk/arch/x86/kvm/mmu.c | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index e2356fde1e91..f054d7029195 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e4b502ead259fcf70839414abb7c8cdc3b523f01
+refs/heads/master: 9a3aad70572c3f4d55e7f09ac4eb313d41d0a484
diff --git a/trunk/arch/x86/kvm/mmu.c b/trunk/arch/x86/kvm/mmu.c
index e4b862eb8885..0dcc95e09876 100644
--- a/trunk/arch/x86/kvm/mmu.c
+++ b/trunk/arch/x86/kvm/mmu.c
@@ -682,9 +682,14 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
 static void set_spte_track_bits(u64 *sptep, u64 new_spte)
 {
 	pfn_t pfn;
-	u64 old_spte;
+	u64 old_spte = *sptep;
+
+	if (!shadow_accessed_mask || !is_shadow_present_pte(old_spte) ||
+	      old_spte & shadow_accessed_mask) {
+		__set_spte(sptep, new_spte);
+	} else
+		old_spte = __xchg_spte(sptep, new_spte);
 
-	old_spte = __xchg_spte(sptep, new_spte);
 	if (!is_rmap_spte(old_spte))
 		return;
 	pfn = spte_to_pfn(old_spte);