diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h
index 40cd3e0..d8ce629 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFECompositionState.h
@@ -40,6 +40,29 @@
 
 namespace android::compositionengine {
 
+// More complex metadata for this layer
+struct GenericLayerMetadataEntry {
+    // True if the metadata may affect the composed result.
+    // See setLayerGenericMetadata in IComposerClient.hal
+    bool mandatory;
+
+    // Byte blob or parcel
+    std::vector<uint8_t> value;
+
+    std::string dumpAsString() const;
+};
+
+inline bool operator==(const GenericLayerMetadataEntry& lhs, const GenericLayerMetadataEntry& rhs) {
+    return lhs.mandatory == rhs.mandatory && lhs.value == rhs.value;
+}
+
+// Defining PrintTo helps with Google Tests.
+inline void PrintTo(const GenericLayerMetadataEntry& v, ::std::ostream* os) {
+    *os << v.dumpAsString();
+}
+
+using GenericLayerMetadataMap = std::unordered_map<std::string, GenericLayerMetadataEntry>;
+
 /*
  * Used by LayerFE::getCompositionState
  */
@@ -115,6 +138,8 @@
     // The appId for this layer
     int appId{0};
 
+    GenericLayerMetadataMap metadata;
+
     /*
      * Per-frame content
      */
diff --git a/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp b/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp
index 3e0f803..02e3a45 100644
--- a/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/LayerFECompositionState.cpp
@@ -32,6 +32,20 @@
 
 } // namespace
 
+std::string GenericLayerMetadataEntry::dumpAsString() const {
+    using android::base::StringAppendF;
+    std::string out;
+
+    out.append("GenericLayerMetadataEntry{mandatory: ");
+    StringAppendF(&out, "%d", mandatory);
+    out.append(" value: ");
+    for (uint8_t byte : value) {
+        StringAppendF(&out, "0x08%" PRIx8 " ", byte);
+    }
+    out.append("]}");
+    return out;
+}
+
 LayerFECompositionState::~LayerFECompositionState() = default;
 
 void LayerFECompositionState::dump(std::string& out) const {
@@ -65,6 +79,17 @@
     dumpVal(out, "type", type);
     dumpVal(out, "appId", appId);
 
+    if (!metadata.empty()) {
+        out.append("\n      metadata {");
+        for (const auto& [key, entry] : metadata) {
+            out.append("\n           ");
+            out.append(key);
+            out.append("=");
+            out.append(entry.dumpAsString());
+        }
+        out.append("\n      }\n      ");
+    }
+
     dumpVal(out, "composition type", toString(compositionType), compositionType);
 
     out.append("\n      buffer: ");
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
index b538d75..3aa7956 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
@@ -406,6 +406,14 @@
         ALOGE("[%s] Failed to set info %s (%d)", getLayerFE().getDebugName(),
               to_string(error).c_str(), static_cast<int32_t>(error));
     }
+
+    for (const auto& [name, entry] : outputIndependentState.metadata) {
+        if (auto error = hwcLayer->setLayerGenericMetadata(name, entry.mandatory, entry.value);
+            error != HWC2::Error::None) {
+            ALOGE("[%s] Failed to set generic metadata %s %s (%d)", getLayerFE().getDebugName(),
+                  name.c_str(), to_string(error).c_str(), static_cast<int32_t>(error));
+        }
+    }
 }
 
 void OutputLayer::writeOutputDependentPerFrameStateToHWC(HWC2::Layer* hwcLayer) {
@@ -661,4 +669,3 @@
 
 } // namespace impl
 } // namespace android::compositionengine
-
diff --git a/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h b/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
index a51cc67..be89c1a 100644
--- a/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
+++ b/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
@@ -65,6 +65,8 @@
     MOCK_METHOD2(setInfo, Error(uint32_t, uint32_t));
 
     MOCK_METHOD1(setColorTransform, Error(const android::mat4&));
+    MOCK_METHOD3(setLayerGenericMetadata,
+                 Error(const std::string&, bool, const std::vector<uint8_t>&));
 };
 
 } // namespace mock
diff --git a/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h b/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
index 502a33f..9995ce1 100644
--- a/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
+++ b/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
@@ -36,7 +36,7 @@
     HWComposer();
     ~HWComposer() override;
 
-    MOCK_METHOD2(registerCallback, void(HWC2::ComposerCallback*, int32_t));
+    MOCK_METHOD2(setConfiguration, void(HWC2::ComposerCallback*, int32_t));
     MOCK_CONST_METHOD3(getDisplayIdentificationData,
                        bool(hwc2_display_t, uint8_t*, DisplayIdentificationData*));
     MOCK_CONST_METHOD1(hasCapability, bool(HWC2::Capability));
@@ -96,6 +96,8 @@
     MOCK_METHOD2(setAutoLowLatencyMode, status_t(DisplayId, bool));
     MOCK_METHOD2(getSupportedContentTypes, status_t(DisplayId, std::vector<HWC2::ContentType>*));
     MOCK_METHOD2(setContentType, status_t(DisplayId, HWC2::ContentType));
+    MOCK_CONST_METHOD0(getSupportedLayerGenericMetadata,
+                       const std::unordered_map<std::string, bool>&());
 
     MOCK_CONST_METHOD1(dump, void(std::string&));
     MOCK_CONST_METHOD0(getComposer, android::Hwc2::Composer*());
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
index 963062f..1b5617c 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
@@ -625,6 +625,8 @@
     static constexpr ui::Dataspace kDataspace = static_cast<ui::Dataspace>(71);
     static constexpr int kSupportedPerFrameMetadata = 101;
     static constexpr int kExpectedHwcSlot = 0;
+    static constexpr bool kLayerGenericMetadata1Mandatory = true;
+    static constexpr bool kLayerGenericMetadata2Mandatory = true;
 
     static const half4 kColor;
     static const Rect kDisplayFrame;
@@ -635,6 +637,10 @@
     static native_handle_t* kSidebandStreamHandle;
     static const sp<GraphicBuffer> kBuffer;
     static const sp<Fence> kFence;
+    static const std::string kLayerGenericMetadata1Key;
+    static const std::vector<uint8_t> kLayerGenericMetadata1Value;
+    static const std::string kLayerGenericMetadata2Key;
+    static const std::vector<uint8_t> kLayerGenericMetadata2Value;
 
     OutputLayerWriteStateToHWCTest() {
         auto& outputLayerState = mOutputLayer.editState();
@@ -669,6 +675,13 @@
     // Some tests may need to simulate unsupported HWC calls
     enum class SimulateUnsupported { None, ColorTransform };
 
+    void includeGenericLayerMetadataInState() {
+        mLayerFEState.metadata[kLayerGenericMetadata1Key] = {kLayerGenericMetadata1Mandatory,
+                                                             kLayerGenericMetadata1Value};
+        mLayerFEState.metadata[kLayerGenericMetadata2Key] = {kLayerGenericMetadata2Mandatory,
+                                                             kLayerGenericMetadata2Value};
+    }
+
     void expectGeometryCommonCalls() {
         EXPECT_CALL(*mHwcLayer, setDisplayFrame(kDisplayFrame)).WillOnce(Return(kError));
         EXPECT_CALL(*mHwcLayer, setSourceCrop(kSourceCrop)).WillOnce(Return(kError));
@@ -720,6 +733,18 @@
         EXPECT_CALL(*mHwcLayer, setBuffer(kExpectedHwcSlot, kBuffer, kFence));
     }
 
+    void expectGenericLayerMetadataCalls() {
+        // Note: Can be in any order.
+        EXPECT_CALL(*mHwcLayer,
+                    setLayerGenericMetadata(kLayerGenericMetadata1Key,
+                                            kLayerGenericMetadata1Mandatory,
+                                            kLayerGenericMetadata1Value));
+        EXPECT_CALL(*mHwcLayer,
+                    setLayerGenericMetadata(kLayerGenericMetadata2Key,
+                                            kLayerGenericMetadata2Mandatory,
+                                            kLayerGenericMetadata2Value));
+    }
+
     std::shared_ptr<HWC2::mock::Layer> mHwcLayer{std::make_shared<StrictMock<HWC2::mock::Layer>>()};
     StrictMock<mock::DisplayColorProfile> mDisplayColorProfile;
 };
@@ -739,6 +764,13 @@
         reinterpret_cast<native_handle_t*>(1031);
 const sp<GraphicBuffer> OutputLayerWriteStateToHWCTest::kBuffer;
 const sp<Fence> OutputLayerWriteStateToHWCTest::kFence;
+const std::string OutputLayerWriteStateToHWCTest::kLayerGenericMetadata1Key =
+        "com.example.metadata.1";
+const std::vector<uint8_t> OutputLayerWriteStateToHWCTest::kLayerGenericMetadata1Value{{1, 2, 3}};
+const std::string OutputLayerWriteStateToHWCTest::kLayerGenericMetadata2Key =
+        "com.example.metadata.2";
+const std::vector<uint8_t> OutputLayerWriteStateToHWCTest::kLayerGenericMetadata2Value{
+        {4, 5, 6, 7}};
 
 TEST_F(OutputLayerWriteStateToHWCTest, doesNothingIfNoFECompositionState) {
     EXPECT_CALL(*mLayerFE, getCompositionState()).WillOnce(Return(nullptr));
@@ -862,6 +894,30 @@
     mOutputLayer.writeStateToHWC(false);
 }
 
+TEST_F(OutputLayerWriteStateToHWCTest, allStateIncludesMetadataIfPresent) {
+    mLayerFEState.compositionType = Hwc2::IComposerClient::Composition::DEVICE;
+    includeGenericLayerMetadataInState();
+
+    expectGeometryCommonCalls();
+    expectPerFrameCommonCalls();
+    expectSetHdrMetadataAndBufferCalls();
+    expectGenericLayerMetadataCalls();
+    expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
+
+    mOutputLayer.writeStateToHWC(true);
+}
+
+TEST_F(OutputLayerWriteStateToHWCTest, perFrameStateDoesNotIncludeMetadataIfPresent) {
+    mLayerFEState.compositionType = Hwc2::IComposerClient::Composition::DEVICE;
+    includeGenericLayerMetadataInState();
+
+    expectPerFrameCommonCalls();
+    expectSetHdrMetadataAndBufferCalls();
+    expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
+
+    mOutputLayer.writeStateToHWC(false);
+}
+
 /*
  * OutputLayer::writeCursorPositionToHWC()
  */
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index 41e7879..e8bf2d8 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -734,12 +734,11 @@
 
 Layer::Layer(android::Hwc2::Composer& composer, const std::unordered_set<Capability>& capabilities,
              hwc2_display_t displayId, hwc2_layer_t layerId)
-  : mComposer(composer),
-    mCapabilities(capabilities),
-    mDisplayId(displayId),
-    mId(layerId),
-    mColorMatrix(android::mat4())
-{
+      : mComposer(composer),
+        mCapabilities(capabilities),
+        mDisplayId(displayId),
+        mId(layerId),
+        mColorMatrix(android::mat4()) {
     ALOGV("Created layer %" PRIu64 " on display %" PRIu64, layerId, displayId);
 }
 
@@ -979,6 +978,13 @@
     return error;
 }
 
+// Composer HAL 2.4
+Error Layer::setLayerGenericMetadata(const std::string& name, bool mandatory,
+                                     const std::vector<uint8_t>& value) {
+    auto intError = mComposer.setLayerGenericMetadata(mDisplayId, mId, name, mandatory, value);
+    return static_cast<Error>(intError);
+}
+
 } // namespace impl
 } // namespace HWC2
 
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index e7cf5ff..5804903 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -374,6 +374,10 @@
 
     // Composer HAL 2.3
     [[clang::warn_unused_result]] virtual Error setColorTransform(const android::mat4& matrix) = 0;
+
+    // Composer HAL 2.4
+    [[clang::warn_unused_result]] virtual Error setLayerGenericMetadata(
+            const std::string& name, bool mandatory, const std::vector<uint8_t>& value) = 0;
 };
 
 namespace impl {
@@ -382,8 +386,7 @@
 
 class Layer : public HWC2::Layer {
 public:
-    Layer(android::Hwc2::Composer& composer,
-          const std::unordered_set<Capability>& capabilities,
+    Layer(android::Hwc2::Composer& composer, const std::unordered_set<Capability>& capabilities,
           hwc2_display_t displayId, hwc2_layer_t layerId);
     ~Layer() override;
 
@@ -412,6 +415,10 @@
     // Composer HAL 2.3
     Error setColorTransform(const android::mat4& matrix) override;
 
+    // Composer HAL 2.4
+    Error setLayerGenericMetadata(const std::string& name, bool mandatory,
+                                  const std::vector<uint8_t>& value) override;
+
 private:
     // These are references to data owned by HWC2::Device, which will outlive
     // this HWC2::Layer, so these references are guaranteed to be valid for
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index f8d45c0..bb6f696 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -148,20 +148,20 @@
 namespace impl {
 
 HWComposer::HWComposer(std::unique_ptr<Hwc2::Composer> composer) : mComposer(std::move(composer)) {
-    loadCapabilities();
 }
 
 HWComposer::HWComposer(const std::string& composerServiceName)
       : mComposer(std::make_unique<Hwc2::impl::Composer>(composerServiceName)) {
-    loadCapabilities();
 }
 
 HWComposer::~HWComposer() {
     mDisplayData.clear();
 }
 
-void HWComposer::registerCallback(HWC2::ComposerCallback* callback,
-                                  int32_t sequenceId) {
+void HWComposer::setConfiguration(HWC2::ComposerCallback* callback, int32_t sequenceId) {
+    loadCapabilities();
+    loadLayerMetadataSupport();
+
     if (mRegisteredCallback) {
         ALOGW("Callback already registered. Ignored extra registration attempt.");
         return;
@@ -871,6 +871,10 @@
     return NO_ERROR;
 }
 
+const std::unordered_map<std::string, bool>& HWComposer::getSupportedLayerGenericMetadata() const {
+    return mSupportedLayerGenericMetadata;
+}
+
 void HWComposer::dump(std::string& result) const {
     result.append(mComposer->dumpDebugInfo());
 }
@@ -946,6 +950,22 @@
     }
 }
 
+void HWComposer::loadLayerMetadataSupport() {
+    mSupportedLayerGenericMetadata.clear();
+
+    std::vector<Hwc2::IComposerClient::LayerGenericMetadataKey> supportedMetadataKeyInfo;
+    const auto error = mComposer->getLayerGenericMetadataKeys(&supportedMetadataKeyInfo);
+    if (error != hardware::graphics::composer::V2_4::Error::NONE) {
+        ALOGE("%s: %s failed: %s (%d)", __FUNCTION__, "getLayerGenericMetadataKeys",
+              toString(error).c_str(), static_cast<int32_t>(error));
+        return;
+    }
+
+    for (const auto& [name, mandatory] : supportedMetadataKeyInfo) {
+        mSupportedLayerGenericMetadata.emplace(name, mandatory);
+    }
+}
+
 uint32_t HWComposer::getMaxVirtualDisplayCount() const {
     return mComposer->getMaxVirtualDisplayCount();
 }
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index effe43b..76e831b 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -55,11 +55,16 @@
 class Output;
 } // namespace compositionengine
 
+struct KnownHWCGenericLayerMetadata {
+    const char* name;
+    const uint32_t id;
+};
+
 class HWComposer {
 public:
     virtual ~HWComposer();
 
-    virtual void registerCallback(HWC2::ComposerCallback* callback, int32_t sequenceId) = 0;
+    virtual void setConfiguration(HWC2::ComposerCallback* callback, int32_t sequenceId) = 0;
 
     virtual bool getDisplayIdentificationData(hwc2_display_t hwcDisplayId, uint8_t* outPort,
                                               DisplayIdentificationData* outData) const = 0;
@@ -194,6 +199,8 @@
     virtual status_t getSupportedContentTypes(
             DisplayId displayId, std::vector<HWC2::ContentType>* outSupportedContentTypes) = 0;
     virtual status_t setContentType(DisplayId displayId, HWC2::ContentType contentType) = 0;
+    virtual const std::unordered_map<std::string, bool>& getSupportedLayerGenericMetadata()
+            const = 0;
 
     // for debugging ----------------------------------------------------------
     virtual void dump(std::string& out) const = 0;
@@ -217,7 +224,7 @@
 
     ~HWComposer() override;
 
-    void registerCallback(HWC2::ComposerCallback* callback, int32_t sequenceId) override;
+    void setConfiguration(HWC2::ComposerCallback* callback, int32_t sequenceId) override;
 
     bool getDisplayIdentificationData(hwc2_display_t hwcDisplayId, uint8_t* outPort,
                                       DisplayIdentificationData* outData) const override;
@@ -329,6 +336,8 @@
                                       std::vector<HWC2::ContentType>*) override;
     status_t setContentType(DisplayId displayId, HWC2::ContentType) override;
 
+    const std::unordered_map<std::string, bool>& getSupportedLayerGenericMetadata() const override;
+
     // for debugging ----------------------------------------------------------
     void dump(std::string& out) const override;
 
@@ -351,6 +360,7 @@
 
     std::optional<DisplayIdentificationInfo> onHotplugConnect(hwc2_display_t hwcDisplayId);
     void loadCapabilities();
+    void loadLayerMetadataSupport();
     uint32_t getMaxVirtualDisplayCount() const;
 
     struct DisplayData {
@@ -379,6 +389,7 @@
 
     std::unique_ptr<android::Hwc2::Composer> mComposer;
     std::unordered_set<HWC2::Capability> mCapabilities;
+    std::unordered_map<std::string, bool> mSupportedLayerGenericMetadata;
     bool mRegisteredCallback = false;
 
     std::unordered_map<hwc2_display_t, DisplayId> mPhysicalDisplayIdMap;
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index fd86da8..7271f42 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -475,6 +475,26 @@
 
     compositionState->type = type;
     compositionState->appId = appId;
+
+    compositionState->metadata.clear();
+    const auto& supportedMetadata = mFlinger->getHwComposer().getSupportedLayerGenericMetadata();
+    for (const auto& [key, mandatory] : supportedMetadata) {
+        const auto& genericLayerMetadataCompatibilityMap =
+                mFlinger->getGenericLayerMetadataKeyMap();
+        auto compatIter = genericLayerMetadataCompatibilityMap.find(key);
+        if (compatIter == std::end(genericLayerMetadataCompatibilityMap)) {
+            continue;
+        }
+        const uint32_t id = compatIter->second;
+
+        auto it = drawingState.metadata.mMap.find(id);
+        if (it == std::end(drawingState.metadata.mMap)) {
+            continue;
+        }
+
+        compositionState->metadata
+                .emplace(key, compositionengine::GenericLayerMetadataEntry{mandatory, it->second});
+    }
 }
 
 void Layer::preparePerFrameCompositionState() {
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 67c3d52..46fd893 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -57,6 +57,7 @@
 #include <gui/IDisplayEventConnection.h>
 #include <gui/IProducerListener.h>
 #include <gui/LayerDebugInfo.h>
+#include <gui/LayerMetadata.h>
 #include <gui/Surface.h>
 #include <input/IInputFlinger.h>
 #include <renderengine/RenderEngine.h>
@@ -622,7 +623,7 @@
     LOG_ALWAYS_FATAL_IF(mVrFlingerRequestsDisplay,
             "Starting with vr flinger active is not currently supported.");
     mCompositionEngine->setHwComposer(getFactory().createHWComposer(getBE().mHwcServiceName));
-    mCompositionEngine->getHwComposer().registerCallback(this, getBE().mComposerSequenceId);
+    mCompositionEngine->getHwComposer().setConfiguration(this, getBE().mComposerSequenceId);
     // Process any initial hotplug and resulting display changes.
     processDisplayHotplugEventsLocked();
     const auto display = getDefaultDisplayDeviceLocked();
@@ -1682,7 +1683,7 @@
     mCompositionEngine->setHwComposer(std::unique_ptr<HWComposer>());
     mCompositionEngine->setHwComposer(getFactory().createHWComposer(
             vrFlingerRequestsDisplay ? "vr" : getBE().mHwcServiceName));
-    getHwComposer().registerCallback(this, ++getBE().mComposerSequenceId);
+    mCompositionEngine->getHwComposer().setConfiguration(this, ++getBE().mComposerSequenceId);
 
     LOG_ALWAYS_FATAL_IF(!getHwComposer().getComposer()->isRemote(),
                         "Switched to non-remote hardware composer");
@@ -5855,6 +5856,21 @@
     return NO_ERROR;
 }
 
+const std::unordered_map<std::string, uint32_t>& SurfaceFlinger::getGenericLayerMetadataKeyMap()
+        const {
+    // TODO(b/149500060): Remove this fixed/static mapping. Please prefer taking
+    // on the work to remove the table in that bug rather than adding more to
+    // it.
+    static const std::unordered_map<std::string, uint32_t> genericLayerMetadataKeyMap{
+            // Note: METADATA_OWNER_UID and METADATA_WINDOW_TYPE are officially
+            // supported, and exposed via the
+            // IVrComposerClient::VrCommand::SET_LAYER_INFO command.
+            {"org.chromium.arc.V1_0.TaskId", METADATA_TASK_ID},
+            {"org.chromium.arc.V1_0.CursorInfo", METADATA_MOUSE_CURSOR},
+    };
+    return genericLayerMetadataKeyMap;
+}
+
 } // namespace android
 
 #if defined(__gl_h_)
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 0d43215..0144b4e 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -1153,6 +1153,15 @@
 
     std::atomic<nsecs_t> mExpectedPresentTime = 0;
 
+    /* ------------------------------------------------------------------------
+     * Generic Layer Metadata
+     */
+    const std::unordered_map<std::string, uint32_t>& getGenericLayerMetadataKeyMap() const;
+
+    /* ------------------------------------------------------------------------
+     * Misc
+     */
+
     std::mutex mActiveConfigLock;
     // This bit is set once we start setting the config. We read from this bit during the
     // process. If at the end, this bit is different than mDesiredActiveConfig, we restart
diff --git a/services/surfaceflinger/tests/unittests/Android.bp b/services/surfaceflinger/tests/unittests/Android.bp
index d046f76..1cd8731 100644
--- a/services/surfaceflinger/tests/unittests/Android.bp
+++ b/services/surfaceflinger/tests/unittests/Android.bp
@@ -42,6 +42,7 @@
         "DisplayTransactionTest.cpp",
         "EventControlThreadTest.cpp",
         "EventThreadTest.cpp",
+        "HWComposerTest.cpp",
         "OneShotTimerTest.cpp",
         "LayerHistoryTest.cpp",
         "LayerHistoryTestV2.cpp",
diff --git a/services/surfaceflinger/tests/unittests/CompositionTest.cpp b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
index 6e83166..1dfb6ba 100644
--- a/services/surfaceflinger/tests/unittests/CompositionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
@@ -116,8 +116,6 @@
 
     void setupComposer(int virtualDisplayCount) {
         mComposer = new Hwc2::mock::Composer();
-        EXPECT_CALL(*mComposer, getCapabilities())
-                .WillOnce(Return(std::vector<IComposer::Capability>()));
         EXPECT_CALL(*mComposer, getMaxVirtualDisplayCount()).WillOnce(Return(virtualDisplayCount));
         mFlinger.setupComposer(std::unique_ptr<Hwc2::Composer>(mComposer));
 
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
index dddad92..232255f 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
@@ -201,8 +201,6 @@
 
 void DisplayTransactionTest::injectMockComposer(int virtualDisplayCount) {
     mComposer = new Hwc2::mock::Composer();
-    EXPECT_CALL(*mComposer, getCapabilities())
-            .WillOnce(Return(std::vector<IComposer::Capability>()));
     EXPECT_CALL(*mComposer, getMaxVirtualDisplayCount()).WillOnce(Return(virtualDisplayCount));
     mFlinger.setupComposer(std::unique_ptr<Hwc2::Composer>(mComposer));
 
diff --git a/services/surfaceflinger/tests/unittests/HWComposerTest.cpp b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
new file mode 100644
index 0000000..c6fe205
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2020 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.
+ */
+
+// TODO(b/129481165): remove the #pragma below and fix conversion issues
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wconversion"
+
+#undef LOG_TAG
+#define LOG_TAG "LibSurfaceFlingerUnittests"
+
+#include <vector>
+
+#include <gmock/gmock.h>
+#include <gui/LayerMetadata.h>
+#include <log/log.h>
+
+#include "DisplayHardware/HWComposer.h"
+#include "mock/DisplayHardware/MockComposer.h"
+
+// TODO(b/129481165): remove the #pragma below and fix conversion issues
+#pragma clang diagnostic pop // ignored "-Wconversion"
+
+namespace android {
+namespace {
+
+using ::testing::_;
+using ::testing::DoAll;
+using ::testing::ElementsAreArray;
+using ::testing::Return;
+using ::testing::SetArgPointee;
+using ::testing::StrictMock;
+
+struct MockHWC2ComposerCallback : public HWC2::ComposerCallback {
+    ~MockHWC2ComposerCallback() = default;
+
+    MOCK_METHOD3(onHotplugReceived,
+                 void(int32_t sequenceId, hwc2_display_t display, HWC2::Connection connection));
+    MOCK_METHOD2(onRefreshReceived, void(int32_t sequenceId, hwc2_display_t display));
+    MOCK_METHOD4(onVsyncReceived,
+                 void(int32_t sequenceId, hwc2_display_t display, int64_t timestamp,
+                      std::optional<hwc2_vsync_period_t> vsyncPeriod));
+    MOCK_METHOD3(onVsyncPeriodTimingChangedReceived,
+                 void(int32_t sequenceId, hwc2_display_t display,
+                      const hwc_vsync_period_change_timeline_t& updatedTimeline));
+    MOCK_METHOD2(onSeamlessPossible, void(int32_t sequenceId, hwc2_display_t display));
+};
+
+struct HWComposerTest : public testing::Test {
+    Hwc2::mock::Composer* mHal = new StrictMock<Hwc2::mock::Composer>();
+};
+
+struct HWComposerSetConfigurationTest : public HWComposerTest {
+    StrictMock<MockHWC2ComposerCallback> mCallback;
+};
+
+TEST_F(HWComposerSetConfigurationTest, loadsLayerMetadataSupport) {
+    const std::string kMetadata1Name = "com.example.metadata.1";
+    constexpr bool kMetadata1Mandatory = false;
+    const std::string kMetadata2Name = "com.example.metadata.2";
+    constexpr bool kMetadata2Mandatory = true;
+
+    EXPECT_CALL(*mHal, getMaxVirtualDisplayCount()).WillOnce(Return(0));
+    EXPECT_CALL(*mHal, getCapabilities())
+            .WillOnce(Return(std::vector<Hwc2::IComposer::Capability>{}));
+    EXPECT_CALL(*mHal, getLayerGenericMetadataKeys(_))
+            .WillOnce(DoAll(SetArgPointee<0>(
+                                    std::vector<Hwc2::IComposerClient::LayerGenericMetadataKey>{
+                                            {kMetadata1Name, kMetadata1Mandatory},
+                                            {kMetadata2Name, kMetadata2Mandatory},
+                                    }),
+                            Return(hardware::graphics::composer::V2_4::Error::NONE)));
+    EXPECT_CALL(*mHal, registerCallback(_));
+    EXPECT_CALL(*mHal, isVsyncPeriodSwitchSupported()).WillOnce(Return(false));
+
+    impl::HWComposer hwc{std::unique_ptr<Hwc2::Composer>(mHal)};
+    hwc.setConfiguration(&mCallback, 123);
+
+    const auto& supported = hwc.getSupportedLayerGenericMetadata();
+    EXPECT_EQ(2u, supported.size());
+    EXPECT_EQ(1u, supported.count(kMetadata1Name));
+    EXPECT_EQ(kMetadata1Mandatory, supported.find(kMetadata1Name)->second);
+    EXPECT_EQ(1u, supported.count(kMetadata2Name));
+    EXPECT_EQ(kMetadata2Mandatory, supported.find(kMetadata2Name)->second);
+}
+
+TEST_F(HWComposerSetConfigurationTest, handlesUnsupportedCallToGetLayerGenericMetadataKeys) {
+    EXPECT_CALL(*mHal, getMaxVirtualDisplayCount()).WillOnce(Return(0));
+    EXPECT_CALL(*mHal, getCapabilities())
+            .WillOnce(Return(std::vector<Hwc2::IComposer::Capability>{}));
+    EXPECT_CALL(*mHal, getLayerGenericMetadataKeys(_))
+            .WillOnce(Return(hardware::graphics::composer::V2_4::Error::UNSUPPORTED));
+    EXPECT_CALL(*mHal, registerCallback(_));
+    EXPECT_CALL(*mHal, isVsyncPeriodSwitchSupported()).WillOnce(Return(false));
+
+    impl::HWComposer hwc{std::unique_ptr<Hwc2::Composer>(mHal)};
+    hwc.setConfiguration(&mCallback, 123);
+
+    const auto& supported = hwc.getSupportedLayerGenericMetadata();
+    EXPECT_EQ(0u, supported.size());
+}
+
+struct HWComposerLayerTest : public testing::Test {
+    static constexpr hwc2_display_t kDisplayId = static_cast<hwc2_display_t>(1001);
+    static constexpr hwc2_layer_t kLayerId = static_cast<hwc2_layer_t>(1002);
+
+    HWComposerLayerTest(const std::unordered_set<HWC2::Capability>& capabilities)
+          : mCapabilies(capabilities) {}
+
+    ~HWComposerLayerTest() override { EXPECT_CALL(*mHal, destroyLayer(kDisplayId, kLayerId)); }
+
+    std::unique_ptr<Hwc2::mock::Composer> mHal{new StrictMock<Hwc2::mock::Composer>()};
+    const std::unordered_set<HWC2::Capability> mCapabilies;
+    HWC2::impl::Layer mLayer{*mHal, mCapabilies, kDisplayId, kLayerId};
+};
+
+struct HWComposerLayerGenericMetadataTest : public HWComposerLayerTest {
+    static const std::string kLayerGenericMetadata1Name;
+    static constexpr bool kLayerGenericMetadata1Mandatory = false;
+    static const std::vector<uint8_t> kLayerGenericMetadata1Value;
+    static const std::string kLayerGenericMetadata2Name;
+    static constexpr bool kLayerGenericMetadata2Mandatory = true;
+    static const std::vector<uint8_t> kLayerGenericMetadata2Value;
+
+    HWComposerLayerGenericMetadataTest() : HWComposerLayerTest({}) {}
+};
+
+const std::string HWComposerLayerGenericMetadataTest::kLayerGenericMetadata1Name =
+        "com.example.metadata.1";
+
+const std::vector<uint8_t> HWComposerLayerGenericMetadataTest::kLayerGenericMetadata1Value = {1u,
+                                                                                              2u,
+                                                                                              3u};
+
+const std::string HWComposerLayerGenericMetadataTest::kLayerGenericMetadata2Name =
+        "com.example.metadata.2";
+
+const std::vector<uint8_t> HWComposerLayerGenericMetadataTest::kLayerGenericMetadata2Value = {45u,
+                                                                                              67u};
+
+TEST_F(HWComposerLayerGenericMetadataTest, forwardsSupportedMetadata) {
+    EXPECT_CALL(*mHal,
+                setLayerGenericMetadata(kDisplayId, kLayerId, kLayerGenericMetadata1Name,
+                                        kLayerGenericMetadata1Mandatory,
+                                        kLayerGenericMetadata1Value))
+            .WillOnce(Return(hardware::graphics::composer::V2_4::Error::NONE));
+    auto result = mLayer.setLayerGenericMetadata(kLayerGenericMetadata1Name,
+                                                 kLayerGenericMetadata1Mandatory,
+                                                 kLayerGenericMetadata1Value);
+    EXPECT_EQ(HWC2::Error::None, result);
+
+    EXPECT_CALL(*mHal,
+                setLayerGenericMetadata(kDisplayId, kLayerId, kLayerGenericMetadata2Name,
+                                        kLayerGenericMetadata2Mandatory,
+                                        kLayerGenericMetadata2Value))
+            .WillOnce(Return(hardware::graphics::composer::V2_4::Error::UNSUPPORTED));
+    result = mLayer.setLayerGenericMetadata(kLayerGenericMetadata2Name,
+                                            kLayerGenericMetadata2Mandatory,
+                                            kLayerGenericMetadata2Value);
+    EXPECT_EQ(HWC2::Error::Unsupported, result);
+}
+
+} // namespace
+} // namespace android
diff --git a/services/surfaceflinger/tests/unittests/RefreshRateSelectionTest.cpp b/services/surfaceflinger/tests/unittests/RefreshRateSelectionTest.cpp
index edd9de4..18b1063 100644
--- a/services/surfaceflinger/tests/unittests/RefreshRateSelectionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/RefreshRateSelectionTest.cpp
@@ -153,8 +153,6 @@
 
 void RefreshRateSelectionTest::setupComposer(int virtualDisplayCount) {
     mComposer = new Hwc2::mock::Composer();
-    EXPECT_CALL(*mComposer, getCapabilities())
-            .WillOnce(Return(std::vector<IComposer::Capability>()));
     EXPECT_CALL(*mComposer, getMaxVirtualDisplayCount()).WillOnce(Return(virtualDisplayCount));
     mFlinger.setupComposer(std::unique_ptr<Hwc2::Composer>(mComposer));