KVM: X86: Zap the invalid list after remote tlb flushing

In mmu_sync_children(), it can zap the invalid list after remote tlb flushing.
Emptifying the invalid list ASAP might help reduce a remote tlb flushing
in some cases.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210918005636.3675-8-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -2035,7 +2035,7 @@ static int mmu_sync_children(struct kvm_vcpu *vcpu,
 			protected |= rmap_write_protect(vcpu, sp->gfn);
 
 		if (protected) {
-			kvm_flush_remote_tlbs(vcpu->kvm);
+			kvm_mmu_remote_flush_or_zap(vcpu->kvm, &invalid_list, true);
 			flush = false;
 		}