From 10a9467f195ae9248b877350b574be48245535a6 Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Mon, 2 Aug 2010 16:14:04 +0800
Subject: [PATCH] --- yaml --- r: 215656 b: refs/heads/master c:
 8672b7217a234c41d425a63b171af809e1169842 h: refs/heads/master v: v3

---
 [refs]                   |  2 +-
 trunk/arch/x86/kvm/mmu.c | 20 +++++++++++++++++---
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index af44c7adcf67..6f2141bdb244 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 251464c464cf7df7d6d548f1065f49a3ecd08118
+refs/heads/master: 8672b7217a234c41d425a63b171af809e1169842
diff --git a/trunk/arch/x86/kvm/mmu.c b/trunk/arch/x86/kvm/mmu.c
index e430a383ad15..c07b9a200bc8 100644
--- a/trunk/arch/x86/kvm/mmu.c
+++ b/trunk/arch/x86/kvm/mmu.c
@@ -299,6 +299,20 @@ static u64 __xchg_spte(u64 *sptep, u64 new_spte)
 #endif
 }
 
+static bool spte_has_volatile_bits(u64 spte)
+{
+	if (!shadow_accessed_mask)
+		return false;
+
+	if (!is_shadow_present_pte(spte))
+		return false;
+
+	if (spte & shadow_accessed_mask)
+		return false;
+
+	return true;
+}
+
 static void update_spte(u64 *sptep, u64 new_spte)
 {
 	u64 old_spte;
@@ -679,14 +693,14 @@ static void set_spte_track_bits(u64 *sptep, u64 new_spte)
 	pfn_t pfn;
 	u64 old_spte = *sptep;
 
-	if (!shadow_accessed_mask || !is_shadow_present_pte(old_spte) ||
-	      old_spte & shadow_accessed_mask) {
+	if (!spte_has_volatile_bits(old_spte))
 		__set_spte(sptep, new_spte);
-	} else
+	else
 		old_spte = __xchg_spte(sptep, new_spte);
 
 	if (!is_rmap_spte(old_spte))
 		return;
+
 	pfn = spte_to_pfn(old_spte);
 	if (!shadow_accessed_mask || old_spte & shadow_accessed_mask)
 		kvm_set_pfn_accessed(pfn);