From 640c14d275ef94bc41fdf3567752daa4c6807209 Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Thu, 22 Sep 2011 16:53:17 +0800
Subject: [PATCH] --- yaml --- r: 281991 b: refs/heads/master c:
 f759e2b4c728cee82e4bc1132d0e41177b79a0b1 h: refs/heads/master i:   281989:
 440a2e9512fd30551f6ee75d5e1f1b84c893a8a9   281987:
 2151d478e6d289aea02bf5ad58419eb95f32c90f   281983:
 1d8411c930149aca4fc1d632fef306d78a958265 v: v3

---
 [refs]                   |  2 +-
 trunk/arch/x86/kvm/mmu.c | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 817c256650bc..8f97659485d3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 51cfe38ea50aa631f58ed8c340ed6f0143c325a8
+refs/heads/master: f759e2b4c728cee82e4bc1132d0e41177b79a0b1
diff --git a/trunk/arch/x86/kvm/mmu.c b/trunk/arch/x86/kvm/mmu.c
index f1b36cf3e3d0..232c5a30ddc8 100644
--- a/trunk/arch/x86/kvm/mmu.c
+++ b/trunk/arch/x86/kvm/mmu.c
@@ -593,6 +593,11 @@ static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
 	return 0;
 }
 
+static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache *cache)
+{
+	return cache->nobjs;
+}
+
 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc,
 				  struct kmem_cache *cache)
 {
@@ -970,6 +975,14 @@ static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level)
 	return &linfo->rmap_pde;
 }
 
+static bool rmap_can_add(struct kvm_vcpu *vcpu)
+{
+	struct kvm_mmu_memory_cache *cache;
+
+	cache = &vcpu->arch.mmu_pte_list_desc_cache;
+	return mmu_memory_cache_free_objects(cache);
+}
+
 static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
 {
 	struct kvm_mmu_page *sp;
@@ -3586,6 +3599,12 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 		break;
 	}
 
+	/*
+	 * No need to care whether allocation memory is successful
+	 * or not since pte prefetch is skiped if it does not have
+	 * enough objects in the cache.
+	 */
+	mmu_topup_memory_caches(vcpu);
 	spin_lock(&vcpu->kvm->mmu_lock);
 	if (atomic_read(&vcpu->kvm->arch.invlpg_counter) != invlpg_counter)
 		gentry = 0;
@@ -3656,7 +3675,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 			mmu_page_zap_pte(vcpu->kvm, sp, spte);
 			if (gentry &&
 			      !((sp->role.word ^ vcpu->arch.mmu.base_role.word)
-			      & mask.word))
+			      & mask.word) && rmap_can_add(vcpu))
 				mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);
 			if (!remote_flush && need_remote_flush(entry, *spte))
 				remote_flush = true;
@@ -3717,10 +3736,6 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code,
 		goto out;
 	}
 
-	r = mmu_topup_memory_caches(vcpu);
-	if (r)
-		goto out;
-
 	er = x86_emulate_instruction(vcpu, cr2, 0, insn, insn_len);
 
 	switch (er) {