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 <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>

arch/x86/kvm/mmu.c

···
 		}
 	}
 
-	if (need_flush)
-		kvm_flush_remote_tlbs(kvm);
-
-	return 0;
+	return need_flush;
 }
 
 struct slot_rmap_walk_iterator {
···
 
 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,

virt/kvm/kvm_main.c

···
 	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);
 }