KVM/MMU: Flush tlb directly in kvm_set_pte_rmapp()

This patch is to flush tlb directly in kvm_set_pte_rmapp()
function when Hyper-V remote TLB flush is available, returning 0
so that kvm_mmu_notifier_change_pte() does not flush again.

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

arch/x86/kvm/mmu.c

@@ -1776,6 +1776,11 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
 		}
 	}
 
+	if (need_flush && kvm_available_flush_tlb_with_range()) {
+		kvm_flush_remote_tlbs_with_address(kvm, gfn, 1);
+		return 0;
+	}
+
 	return need_flush;
 }