diff --git a/services/surfaceflinger/tests/unittests/Android.bp b/services/surfaceflinger/tests/unittests/Android.bp
index b33434e..1b25a36 100644
--- a/services/surfaceflinger/tests/unittests/Android.bp
+++ b/services/surfaceflinger/tests/unittests/Android.bp
@@ -86,6 +86,7 @@
         "TransactionApplicationTest.cpp",
         "TransactionFrameTracerTest.cpp",
         "TransactionSurfaceFrameTest.cpp",
+        "TunnelModeEnabledReporterTest.cpp",
         "StrongTypingTest.cpp",
         "VSyncDispatchTimerQueueTest.cpp",
         "VSyncDispatchRealtimeTest.cpp",
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index d004b9d..a551248 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -276,6 +276,7 @@
     static void setLayerSidebandStream(const sp<Layer>& layer,
                                        const sp<NativeHandle>& sidebandStream) {
         layer->mDrawingState.sidebandStream = sidebandStream;
+        layer->mCurrentState.sidebandStream = sidebandStream;
         layer->mSidebandStream = sidebandStream;
         layer->editCompositionState()->sidebandStream = sidebandStream;
     }
diff --git a/services/surfaceflinger/tests/unittests/TunnelModeEnabledReporterTest.cpp b/services/surfaceflinger/tests/unittests/TunnelModeEnabledReporterTest.cpp
new file mode 100644
index 0000000..d7d7ea7
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/TunnelModeEnabledReporterTest.cpp
@@ -0,0 +1,194 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "TunnelModeEnabledReporterTest"
+
+#include <android/gui/BnTunnelModeEnabledListener.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <gui/LayerMetadata.h>
+
+#include "BufferStateLayer.h"
+#include "TestableSurfaceFlinger.h"
+#include "TunnelModeEnabledReporter.h"
+#include "mock/DisplayHardware/MockComposer.h"
+#include "mock/MockEventThread.h"
+
+namespace android {
+
+using testing::_;
+using testing::Mock;
+using testing::Return;
+
+using android::Hwc2::IComposer;
+using android::Hwc2::IComposerClient;
+
+using FakeHwcDisplayInjector = TestableSurfaceFlinger::FakeHwcDisplayInjector;
+
+constexpr int DEFAULT_SIDEBAND_STREAM = 51;
+
+struct TestableTunnelModeEnabledListener : public gui::BnTunnelModeEnabledListener {
+    TestableTunnelModeEnabledListener() {}
+
+    bool mTunnelModeEnabled = false;
+
+    binder::Status onTunnelModeEnabledChanged(bool tunnelModeEnabled) override {
+        mTunnelModeEnabled = tunnelModeEnabled;
+        return binder::Status::ok();
+    }
+};
+
+class TunnelModeEnabledReporterTest : public testing::Test {
+public:
+    TunnelModeEnabledReporterTest();
+    ~TunnelModeEnabledReporterTest() override;
+
+protected:
+    static constexpr uint32_t WIDTH = 100;
+    static constexpr uint32_t HEIGHT = 100;
+    static constexpr uint32_t LAYER_FLAGS = 0;
+
+    void setupScheduler();
+    void setupComposer(uint32_t virtualDisplayCount);
+    sp<BufferStateLayer> createBufferStateLayer(LayerMetadata metadata);
+
+    TestableSurfaceFlinger mFlinger;
+    Hwc2::mock::Composer* mComposer = nullptr;
+    sp<TestableTunnelModeEnabledListener> mTunnelModeEnabledListener =
+            new TestableTunnelModeEnabledListener();
+    sp<TunnelModeEnabledReporter> mTunnelModeEnabledReporter =
+            new TunnelModeEnabledReporter(*(mFlinger.flinger()));
+};
+
+TunnelModeEnabledReporterTest::TunnelModeEnabledReporterTest() {
+    const ::testing::TestInfo* const test_info =
+            ::testing::UnitTest::GetInstance()->current_test_info();
+    ALOGD("**** Setting up for %s.%s\n", test_info->test_case_name(), test_info->name());
+    setupScheduler();
+    mFlinger.setupComposer(std::make_unique<Hwc2::mock::Composer>());
+    mTunnelModeEnabledReporter->dispatchTunnelModeEnabled(false);
+}
+
+TunnelModeEnabledReporterTest::~TunnelModeEnabledReporterTest() {
+    const ::testing::TestInfo* const test_info =
+            ::testing::UnitTest::GetInstance()->current_test_info();
+    ALOGD("**** Tearing down after %s.%s\n", test_info->test_case_name(), test_info->name());
+    mTunnelModeEnabledReporter->dispatchTunnelModeEnabled(false);
+    mTunnelModeEnabledReporter->removeListener(mTunnelModeEnabledListener);
+}
+
+sp<BufferStateLayer> TunnelModeEnabledReporterTest::createBufferStateLayer(
+        LayerMetadata metadata = {}) {
+    sp<Client> client;
+    LayerCreationArgs args(mFlinger.flinger(), client, "buffer-state-layer", WIDTH, HEIGHT,
+                           LAYER_FLAGS, metadata);
+    return new BufferStateLayer(args);
+}
+
+void TunnelModeEnabledReporterTest::setupScheduler() {
+    auto eventThread = std::make_unique<mock::EventThread>();
+    auto sfEventThread = std::make_unique<mock::EventThread>();
+
+    EXPECT_CALL(*eventThread, registerDisplayEventConnection(_));
+    EXPECT_CALL(*eventThread, createEventConnection(_, _))
+            .WillOnce(Return(new EventThreadConnection(eventThread.get(), /*callingUid=*/0,
+                                                       ResyncCallback())));
+
+    EXPECT_CALL(*sfEventThread, registerDisplayEventConnection(_));
+    EXPECT_CALL(*sfEventThread, createEventConnection(_, _))
+            .WillOnce(Return(new EventThreadConnection(sfEventThread.get(), /*callingUid=*/0,
+                                                       ResyncCallback())));
+
+    auto vsyncController = std::make_unique<mock::VsyncController>();
+    auto vsyncTracker = std::make_unique<mock::VSyncTracker>();
+
+    EXPECT_CALL(*vsyncTracker, nextAnticipatedVSyncTimeFrom(_)).WillRepeatedly(Return(0));
+    EXPECT_CALL(*vsyncTracker, currentPeriod())
+            .WillRepeatedly(Return(FakeHwcDisplayInjector::DEFAULT_VSYNC_PERIOD));
+    EXPECT_CALL(*vsyncTracker, nextAnticipatedVSyncTimeFrom(_)).WillRepeatedly(Return(0));
+    mFlinger.setupScheduler(std::move(vsyncController), std::move(vsyncTracker),
+                            std::move(eventThread), std::move(sfEventThread));
+}
+
+namespace {
+
+TEST_F(TunnelModeEnabledReporterTest, callsAddedListeners) {
+    mTunnelModeEnabledReporter->addListener(mTunnelModeEnabledListener);
+
+    bool expectedTunnelModeEnabled = false;
+    mTunnelModeEnabledReporter->dispatchTunnelModeEnabled(expectedTunnelModeEnabled);
+    EXPECT_EQ(expectedTunnelModeEnabled, mTunnelModeEnabledListener->mTunnelModeEnabled);
+
+    expectedTunnelModeEnabled = true;
+    mTunnelModeEnabledReporter->dispatchTunnelModeEnabled(expectedTunnelModeEnabled);
+    EXPECT_EQ(expectedTunnelModeEnabled, mTunnelModeEnabledListener->mTunnelModeEnabled);
+
+    mTunnelModeEnabledReporter->removeListener(mTunnelModeEnabledListener);
+
+    mTunnelModeEnabledReporter->dispatchTunnelModeEnabled(false);
+    EXPECT_EQ(expectedTunnelModeEnabled, mTunnelModeEnabledListener->mTunnelModeEnabled);
+}
+
+TEST_F(TunnelModeEnabledReporterTest, callsNewListenerImmediately) {
+    bool expectedTunnelModeEnabled = false;
+    mTunnelModeEnabledReporter->dispatchTunnelModeEnabled(expectedTunnelModeEnabled);
+
+    mTunnelModeEnabledReporter->addListener(mTunnelModeEnabledListener);
+    EXPECT_EQ(expectedTunnelModeEnabled, mTunnelModeEnabledListener->mTunnelModeEnabled);
+}
+
+TEST_F(TunnelModeEnabledReporterTest, callsNewListenerWithFreshInformation) {
+    sp<Layer> layer = createBufferStateLayer();
+    sp<NativeHandle> stream =
+            NativeHandle::create(reinterpret_cast<native_handle_t*>(DEFAULT_SIDEBAND_STREAM),
+                                 false);
+    mFlinger.setLayerSidebandStream(layer, stream);
+    mFlinger.mutableCurrentState().layersSortedByZ.add(layer);
+    mTunnelModeEnabledReporter->updateTunnelModeStatus();
+    mTunnelModeEnabledReporter->addListener(mTunnelModeEnabledListener);
+    EXPECT_EQ(true, mTunnelModeEnabledListener->mTunnelModeEnabled);
+    mTunnelModeEnabledReporter->removeListener(mTunnelModeEnabledListener);
+
+    mFlinger.mutableCurrentState().layersSortedByZ.remove(layer);
+    mTunnelModeEnabledReporter->updateTunnelModeStatus();
+    mTunnelModeEnabledReporter->addListener(mTunnelModeEnabledListener);
+    EXPECT_EQ(false, mTunnelModeEnabledListener->mTunnelModeEnabled);
+}
+
+TEST_F(TunnelModeEnabledReporterTest, layerWithSidebandStreamTriggersUpdate) {
+    mTunnelModeEnabledReporter->addListener(mTunnelModeEnabledListener);
+    EXPECT_EQ(false, mTunnelModeEnabledListener->mTunnelModeEnabled);
+
+    sp<Layer> simpleLayer = createBufferStateLayer();
+    sp<Layer> layerWithSidebandStream = createBufferStateLayer();
+    sp<NativeHandle> stream =
+            NativeHandle::create(reinterpret_cast<native_handle_t*>(DEFAULT_SIDEBAND_STREAM),
+                                 false);
+    mFlinger.setLayerSidebandStream(layerWithSidebandStream, stream);
+
+    mFlinger.mutableCurrentState().layersSortedByZ.add(simpleLayer);
+    mFlinger.mutableCurrentState().layersSortedByZ.add(layerWithSidebandStream);
+    mTunnelModeEnabledReporter->updateTunnelModeStatus();
+    EXPECT_EQ(true, mTunnelModeEnabledListener->mTunnelModeEnabled);
+
+    mFlinger.mutableCurrentState().layersSortedByZ.remove(layerWithSidebandStream);
+    mTunnelModeEnabledReporter->updateTunnelModeStatus();
+    EXPECT_EQ(false, mTunnelModeEnabledListener->mTunnelModeEnabled);
+}
+
+} // namespace
+} // namespace android