From: Lan Tianyu <Tianyu.Lan@microsoft.com>
Date: Thu, 6 Dec 2018 13:21:11 +0000 (+0800)
Subject: KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=0cf853c5e238edf503ebda2fe541e6f4a3d5bd40;p=openwrt%2Fstaging%2Fblogic.git

KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()

This patch is to move tlb flush in kvm_set_pte_rmapp() to
kvm_mmu_notifier_change_pte() in order to avoid redundant tlb flush.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index dd71864ded39..5a046f93a41a 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1776,10 +1776,7 @@ restart:
 		}
 	}
 
-	if (need_flush)
-		kvm_flush_remote_tlbs(kvm);
-
-	return 0;
+	return need_flush;
 }
 
 struct slot_rmap_walk_iterator {
@@ -1915,8 +1912,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)
 
 int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
 {
-	kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
-	return 0;
+	return kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
 }
 
 static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f90ceab3840e..cf7cc0554094 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -354,7 +354,10 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
 	idx = srcu_read_lock(&kvm->srcu);
 	spin_lock(&kvm->mmu_lock);
 	kvm->mmu_notifier_seq++;
-	kvm_set_spte_hva(kvm, address, pte);
+
+	if (kvm_set_spte_hva(kvm, address, pte))
+		kvm_flush_remote_tlbs(kvm);
+
 	spin_unlock(&kvm->mmu_lock);
 	srcu_read_unlock(&kvm->srcu, idx);
 }