diff --git a/current.txt b/current.txt
index 6d1e6c6..19a3c0f 100644
--- a/current.txt
+++ b/current.txt
@@ -595,8 +595,9 @@
 4d85e814f94949dae4dc6cb82bbd7d6bb24ffafda6ddb2eac928d2a4fc2e21ce android.hardware.cas@1.2::types
 66931c2506fbb5af61f20138cb05e0a09e7bf67d6964c231d27c648933bb33ec android.hardware.drm@1.3::ICryptoFactory
 994d08ab27d613022c258a9ec48cece7adf2a305e92df5d76ef923e2c6665f64 android.hardware.drm@1.3::IDrmFactory
-1bd8028b974bf1d65cfa102196a2b008afc5d42fe73fed2cb94fa7533d07f581 android.hardware.gnss@2.1::IGnss
+3dacec7801968e1e4479724dc0180442d9e915466bff051f80996266b1a51c2c android.hardware.gnss@2.1::IGnss
 ba62e1e8993bfb9f27fa04816fa0f2241ae2d01edfa3d0c04182e2e5de80045c android.hardware.gnss@2.1::IGnssCallback
+ccdf3c0fb2c02a6d4dc57afb276c3497ae8172b80b00ebc0bf8a0238dd38b01d android.hardware.gnss@2.1::IGnssConfiguration
 5a125c49ca83629e22afc8c39e865509343bfa2c38f0baea9a186bbac103492d android.hardware.gnss@2.1::IGnssMeasurement
 0bfb291708dd4a7c6ec6b9883e2b8592357edde8d7e962ef83918e4a2154ce69 android.hardware.gnss@2.1::IGnssMeasurementCallback
 ce8dbe76eb9ee94b46ef98f725be992e760a5751073d4f4912484026541371f3 android.hardware.health@2.1::IHealth
diff --git a/gnss/2.1/Android.bp b/gnss/2.1/Android.bp
index 5d3d62d..8b0c374 100644
--- a/gnss/2.1/Android.bp
+++ b/gnss/2.1/Android.bp
@@ -11,6 +11,7 @@
         "IGnssCallback.hal",
         "IGnssMeasurement.hal",
         "IGnssMeasurementCallback.hal",
+        "IGnssConfiguration.hal",
     ],
     interfaces: [
         "android.hardware.gnss.measurement_corrections@1.0",
diff --git a/gnss/2.1/IGnss.hal b/gnss/2.1/IGnss.hal
index 812f9cc..2d63392 100644
--- a/gnss/2.1/IGnss.hal
+++ b/gnss/2.1/IGnss.hal
@@ -20,6 +20,7 @@
 
 import IGnssCallback;
 import IGnssMeasurement;
+import IGnssConfiguration;
 
 /**
  * Represents the standard GNSS (Global Navigation Satellite System) interface.
@@ -50,4 +51,15 @@
      * @return gnssMeasurementIface Handle to the IGnssMeasurement interface.
      */
     getExtensionGnssMeasurement_2_1() generates (IGnssMeasurement gnssMeasurementIface);
+
+    /**
+     * This method returns the IGnssConfiguration interface.
+     *
+     * At least one of getExtensionGnssConfiguration(), getExtensionGnssConfiguration_1_1(),
+     * getExtensionGnssConfiguration_2_0(), and getExtensionGnssConfiguration_2_1() methods must
+     * return a non-null handle, and the other methods must return nullptr.
+     *
+     * @return gnssConfigurationIface Handle to the IGnssConfiguration interface.
+     */
+    getExtensionGnssConfiguration_2_1() generates (IGnssConfiguration gnssConfigurationIface);
 };
\ No newline at end of file
diff --git a/gnss/2.1/IGnssConfiguration.hal b/gnss/2.1/IGnssConfiguration.hal
new file mode 100644
index 0000000..8360ba9
--- /dev/null
+++ b/gnss/2.1/IGnssConfiguration.hal
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+package android.hardware.gnss@2.1;
+
+import @2.0::IGnssConfiguration;
+import @2.0::GnssConstellationType;
+
+/**
+ * Extended interface for GNSS Configuration support.
+ */
+interface IGnssConfiguration extends @2.0::IGnssConfiguration {
+    /**
+     * Represents a blacklisted source, updating the GnssConstellationType to 2.0, which supports
+     * IRNSS.
+     */
+    struct BlacklistedSource {
+        /**
+         * Defines the constellation of the given satellite(s).
+         */
+        GnssConstellationType constellation;
+
+        /**
+         * Satellite (space vehicle) ID number, as defined in GnssSvInfo::svid
+         *
+         * Or 0 to blacklist all svid's for the specified constellation
+         */
+        int16_t svid;
+    };
+
+    /**
+     * Injects a vector of BlacklistedSource(s) which the HAL must not use to calculate the
+     * GNSS location output.
+     *
+     * The superset of all satellite sources provided, including wildcards, in the latest call
+     * to this method, is the set of satellites sources that must not be used in calculating
+     * location.
+     *
+     * All measurements from the specified satellites, across frequency bands, are blacklisted
+     * together.
+     *
+     * If this method is never called after the IGnssConfiguration.hal connection is made on boot,
+     * or is called with an empty vector, then no satellites are to be blacklisted as a result of
+     * this API.
+     *
+     * This blacklist must be considered as an additional source of which satellites
+     * should not be trusted for location on top of existing sources of similar information
+     * such as satellite broadcast health being unhealthy and measurement outlier removal.
+     *
+     * @param blacklist The BlacklistedSource(s) of satellites the HAL must not use.
+     *
+     * @return success Whether the HAL accepts and abides by the provided blacklist.
+     */
+    setBlacklist_2_1(vec<BlacklistedSource> blacklist) generates (bool success);
+};
\ No newline at end of file
diff --git a/gnss/2.1/default/Android.bp b/gnss/2.1/default/Android.bp
index a7cf63d..57233aa 100644
--- a/gnss/2.1/default/Android.bp
+++ b/gnss/2.1/default/Android.bp
@@ -23,6 +23,7 @@
     srcs: [
         "Gnss.cpp",
         "GnssMeasurement.cpp",
+        "GnssConfiguration.cpp",
         "service.cpp"
     ],
     shared_libs: [
diff --git a/gnss/2.1/default/Gnss.cpp b/gnss/2.1/default/Gnss.cpp
index 2771f27..384fd49 100644
--- a/gnss/2.1/default/Gnss.cpp
+++ b/gnss/2.1/default/Gnss.cpp
@@ -32,7 +32,7 @@
 
 sp<V2_1::IGnssCallback> Gnss::sGnssCallback_2_1 = nullptr;
 
-Gnss::Gnss() : mMinIntervalMs(1000) {}
+Gnss::Gnss() : mMinIntervalMs(1000), mGnssConfiguration{new GnssConfiguration()} {}
 
 Gnss::~Gnss() {
     stop();
@@ -48,7 +48,7 @@
     mIsActive = true;
     mThread = std::thread([this]() {
         while (mIsActive == true) {
-            auto svStatus = Utils::getMockSvInfoListV2_1();
+            auto svStatus = filterBlacklistedSatellitesV2_1(Utils::getMockSvInfoListV2_1());
             this->reportSvStatus(svStatus);
 
             const auto location = Utils::getMockLocationV2_0();
@@ -60,6 +60,16 @@
     return true;
 }
 
+hidl_vec<GnssSvInfo> Gnss::filterBlacklistedSatellitesV2_1(hidl_vec<GnssSvInfo> gnssSvInfoList) {
+    for (uint32_t i = 0; i < gnssSvInfoList.size(); i++) {
+        if (mGnssConfiguration->isBlacklistedV2_1(gnssSvInfoList[i])) {
+            gnssSvInfoList[i].v2_0.v1_0.svFlag &=
+                    ~static_cast<uint8_t>(V1_0::IGnssCallback::GnssSvFlags::USED_IN_FIX);
+        }
+    }
+    return gnssSvInfoList;
+}
+
 Return<bool> Gnss::stop() {
     ALOGD("stop");
     mIsActive = false;
@@ -270,6 +280,10 @@
     return new GnssMeasurement();
 }
 
+Return<sp<V2_1::IGnssConfiguration>> Gnss::getExtensionGnssConfiguration_2_1() {
+    return mGnssConfiguration;
+}
+
 void Gnss::reportSvStatus(const hidl_vec<GnssSvInfo>& svInfoList) const {
     std::unique_lock<std::mutex> lock(mMutex);
     if (sGnssCallback_2_1 == nullptr) {
diff --git a/gnss/2.1/default/Gnss.h b/gnss/2.1/default/Gnss.h
index a61f71c..674b070 100644
--- a/gnss/2.1/default/Gnss.h
+++ b/gnss/2.1/default/Gnss.h
@@ -22,6 +22,7 @@
 #include <atomic>
 #include <mutex>
 #include <thread>
+#include "GnssConfiguration.h"
 
 namespace android {
 namespace hardware {
@@ -87,6 +88,7 @@
     // Methods from V2_1::IGnss follow.
     Return<bool> setCallback_2_1(const sp<V2_1::IGnssCallback>& callback) override;
     Return<sp<V2_1::IGnssMeasurement>> getExtensionGnssMeasurement_2_1() override;
+    Return<sp<V2_1::IGnssConfiguration>> getExtensionGnssConfiguration_2_1() override;
 
   private:
     void reportLocation(const V2_0::GnssLocation&) const;
@@ -94,9 +96,11 @@
 
     static sp<V2_1::IGnssCallback> sGnssCallback_2_1;
     std::atomic<long> mMinIntervalMs;
+    sp<GnssConfiguration> mGnssConfiguration;
     std::atomic<bool> mIsActive;
     std::thread mThread;
     mutable std::mutex mMutex;
+    hidl_vec<GnssSvInfo> filterBlacklistedSatellitesV2_1(hidl_vec<GnssSvInfo> gnssSvInfoList);
 };
 
 }  // namespace implementation
diff --git a/gnss/2.1/default/GnssConfiguration.cpp b/gnss/2.1/default/GnssConfiguration.cpp
new file mode 100644
index 0000000..cd8f07f
--- /dev/null
+++ b/gnss/2.1/default/GnssConfiguration.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#define LOG_TAG "GnssConfiguration"
+
+#include "GnssConfiguration.h"
+#include <log/log.h>
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace V2_1 {
+namespace implementation {
+
+// Methods from ::android::hardware::gnss::V1_0::IGnssConfiguration follow.
+Return<bool> GnssConfiguration::setSuplEs(bool enable) {
+    ALOGD("setSuplEs enable: %d", enable);
+    // Method deprecated in 2.0 and not expected to be called by the framework.
+    return false;
+}
+
+Return<bool> GnssConfiguration::setSuplVersion(uint32_t) {
+    return true;
+}
+
+Return<bool> GnssConfiguration::setSuplMode(hidl_bitfield<SuplMode>) {
+    return true;
+}
+
+Return<bool> GnssConfiguration::setGpsLock(hidl_bitfield<GpsLock> gpsLock) {
+    ALOGD("setGpsLock gpsLock: %hhu", static_cast<GpsLock>(gpsLock));
+    // Method deprecated in 2.0 and not expected to be called by the framework.
+    return false;
+}
+
+Return<bool> GnssConfiguration::setLppProfile(hidl_bitfield<LppProfile>) {
+    return true;
+}
+
+Return<bool> GnssConfiguration::setGlonassPositioningProtocol(hidl_bitfield<GlonassPosProtocol>) {
+    return true;
+}
+
+Return<bool> GnssConfiguration::setEmergencySuplPdn(bool) {
+    return true;
+}
+
+// Methods from ::android::hardware::gnss::V1_1::IGnssConfiguration follow.
+Return<bool> GnssConfiguration::setBlacklist(
+        const hidl_vec<V1_1::IGnssConfiguration::BlacklistedSource>&) {
+    // TODO (b/122463906): Reuse 1.1 implementation.
+    return bool{};
+}
+
+// Methods from ::android::hardware::gnss::V2_0::IGnssConfiguration follow.
+Return<bool> GnssConfiguration::setEsExtensionSec(uint32_t emergencyExtensionSeconds) {
+    ALOGD("setEsExtensionSec emergencyExtensionSeconds: %d", emergencyExtensionSeconds);
+    return true;
+}
+
+// Methods from ::android::hardware::gnss::V2_1::IGnssConfiguration follow.
+Return<bool> GnssConfiguration::setBlacklist_2_1(
+        const hidl_vec<V2_1::IGnssConfiguration::BlacklistedSource>& sourceList) {
+    std::unique_lock<std::recursive_mutex> lock(mMutex);
+    mBlacklistedConstellationSet.clear();
+    mBlacklistedSourceSet.clear();
+    for (auto source : sourceList) {
+        if (source.svid == 0) {
+            // Wildcard blacklist, i.e., blacklist entire constellation.
+            mBlacklistedConstellationSet.insert(source.constellation);
+        } else {
+            mBlacklistedSourceSet.insert(source);
+        }
+    }
+    return true;
+}
+
+Return<bool> GnssConfiguration::isBlacklistedV2_1(const GnssSvInfoV2_1& gnssSvInfo) const {
+    std::unique_lock<std::recursive_mutex> lock(mMutex);
+    if (mBlacklistedConstellationSet.find(gnssSvInfo.v2_0.constellation) !=
+        mBlacklistedConstellationSet.end()) {
+        return true;
+    }
+    BlacklistedSourceV2_1 source = {.constellation = gnssSvInfo.v2_0.constellation,
+                                    .svid = gnssSvInfo.v2_0.v1_0.svid};
+    return (mBlacklistedSourceSet.find(source) != mBlacklistedSourceSet.end());
+}
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android
\ No newline at end of file
diff --git a/gnss/2.1/default/GnssConfiguration.h b/gnss/2.1/default/GnssConfiguration.h
new file mode 100644
index 0000000..662d61d
--- /dev/null
+++ b/gnss/2.1/default/GnssConfiguration.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#ifndef ANDROID_HARDWARE_GNSS_V2_1_GNSSCONFIGURATION_H
+#define ANDROID_HARDWARE_GNSS_V2_1_GNSSCONFIGURATION_H
+
+#include <android/hardware/gnss/2.1/IGnssCallback.h>
+#include <android/hardware/gnss/2.1/IGnssConfiguration.h>
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+#include <mutex>
+#include <unordered_set>
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace V2_1 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_memory;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+using BlacklistedSourceV2_1 =
+        ::android::hardware::gnss::V2_1::IGnssConfiguration::BlacklistedSource;
+using GnssConstellationTypeV2_0 = V2_0::GnssConstellationType;
+using GnssSvInfoV2_1 = V2_1::IGnssCallback::GnssSvInfo;
+
+struct BlacklistedSourceHashV2_1 {
+    inline int operator()(const BlacklistedSourceV2_1& source) const {
+        return int(source.constellation) * 1000 + int(source.svid);
+    }
+};
+
+struct BlacklistedSourceEqualV2_1 {
+    inline bool operator()(const BlacklistedSourceV2_1& s1, const BlacklistedSourceV2_1& s2) const {
+        return (s1.constellation == s2.constellation) && (s1.svid == s2.svid);
+    }
+};
+
+using BlacklistedSourceSetV2_1 =
+        std::unordered_set<BlacklistedSourceV2_1, BlacklistedSourceHashV2_1,
+                           BlacklistedSourceEqualV2_1>;
+using BlacklistedConstellationSetV2_1 = std::unordered_set<GnssConstellationTypeV2_0>;
+
+struct GnssConfiguration : public IGnssConfiguration {
+    // Methods from ::android::hardware::gnss::V1_0::IGnssConfiguration follow.
+    Return<bool> setSuplEs(bool enabled) override;
+    Return<bool> setSuplVersion(uint32_t version) override;
+    Return<bool> setSuplMode(hidl_bitfield<SuplMode> mode) override;
+    Return<bool> setGpsLock(hidl_bitfield<GpsLock> lock) override;
+    Return<bool> setLppProfile(hidl_bitfield<LppProfile> lppProfile) override;
+    Return<bool> setGlonassPositioningProtocol(hidl_bitfield<GlonassPosProtocol> protocol) override;
+    Return<bool> setEmergencySuplPdn(bool enable) override;
+
+    // Methods from ::android::hardware::gnss::V1_1::IGnssConfiguration follow.
+    Return<bool> setBlacklist(
+            const hidl_vec<V1_1::IGnssConfiguration::BlacklistedSource>& blacklist) override;
+
+    std::recursive_mutex& getMutex() const;
+
+    // Methods from ::android::hardware::gnss::V2_0::IGnssConfiguration follow.
+    Return<bool> setEsExtensionSec(uint32_t emergencyExtensionSeconds) override;
+
+    // Methods from ::android::hardware::gnss::V2_1::IGnssConfiguration follow.
+    Return<bool> setBlacklist_2_1(
+            const hidl_vec<V2_1::IGnssConfiguration::BlacklistedSource>& blacklist) override;
+
+    Return<bool> isBlacklistedV2_1(const GnssSvInfoV2_1& gnssSvInfo) const;
+
+  private:
+    mutable std::recursive_mutex mMutex;
+
+    BlacklistedSourceSetV2_1 mBlacklistedSourceSet;
+    BlacklistedConstellationSetV2_1 mBlacklistedConstellationSet;
+};
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_GNSS_V2_1_GNSSCONFIGURATION_H
\ No newline at end of file
diff --git a/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp b/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp
index ef8249b..45a3d2a 100644
--- a/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp
+++ b/gnss/2.1/vts/functional/gnss_hal_test_cases.cpp
@@ -30,6 +30,13 @@
 using IGnssMeasurement_2_0 = android::hardware::gnss::V2_0::IGnssMeasurement;
 using IGnssMeasurement_1_1 = android::hardware::gnss::V1_1::IGnssMeasurement;
 using IGnssMeasurement_1_0 = android::hardware::gnss::V1_0::IGnssMeasurement;
+using IGnssConfiguration_2_1 = android::hardware::gnss::V2_1::IGnssConfiguration;
+using IGnssConfiguration_2_0 = android::hardware::gnss::V2_0::IGnssConfiguration;
+using IGnssConfiguration_1_1 = android::hardware::gnss::V1_1::IGnssConfiguration;
+using IGnssConfiguration_1_0 = android::hardware::gnss::V1_0::IGnssConfiguration;
+
+using android::hardware::gnss::V2_0::GnssConstellationType;
+using android::hardware::gnss::V2_1::IGnssConfiguration;
 
 /*
  * SetupTeardownCreateCleanup:
@@ -61,6 +68,27 @@
 }
 
 /*
+ * TestGnssConfigurationExtension:
+ * Gets the GnssConfigurationExtension and verifies that it returns an actual extension.
+ */
+TEST_P(GnssHalTest, TestGnssConfigurationExtension) {
+    auto gnssConfiguration_2_1 = gnss_hal_->getExtensionGnssConfiguration_2_1();
+    auto gnssConfiguration_2_0 = gnss_hal_->getExtensionGnssConfiguration_2_0();
+    auto gnssConfiguration_1_1 = gnss_hal_->getExtensionGnssConfiguration_1_1();
+    auto gnssConfiguration_1_0 = gnss_hal_->getExtensionGnssConfiguration();
+    ASSERT_TRUE(gnssConfiguration_2_1.isOk() && gnssConfiguration_2_0.isOk() &&
+                gnssConfiguration_1_1.isOk() && gnssConfiguration_1_0.isOk());
+    sp<IGnssConfiguration_2_1> iGnssConfig_2_1 = gnssConfiguration_2_1;
+    sp<IGnssConfiguration_2_0> iGnssConfig_2_0 = gnssConfiguration_2_0;
+    sp<IGnssConfiguration_1_1> iGnssConfig_1_1 = gnssConfiguration_1_1;
+    sp<IGnssConfiguration_1_0> iGnssConfig_1_0 = gnssConfiguration_1_0;
+    // At least one interface is non-null.
+    int numNonNull = (int)(iGnssConfig_2_1 != nullptr) + (int)(iGnssConfig_2_0 != nullptr) +
+                     (int)(iGnssConfig_1_1 != nullptr) + (int)(iGnssConfig_1_0 != nullptr);
+    ASSERT_TRUE(numNonNull >= 1);
+}
+
+/*
  * TestGnssMeasurementFields:
  * Sets a GnssMeasurementCallback, waits for a measurement, and verifies
  * 1. basebandCN0DbHz is valid
@@ -126,3 +154,338 @@
     ASSERT_TRUE(nonZeroCn0Found);
     StopAndClearLocations();
 }
+
+/*
+ * FindStrongFrequentNonGpsSource:
+ *
+ * Search through a GnssSvStatus list for the strongest non-GPS satellite observed enough times
+ *
+ * returns the strongest source,
+ *         or a source with constellation == UNKNOWN if none are found sufficient times
+ * TODO(skz): create a template for this to reduce code duplication of v2.1 and v2.0 since both
+ * are using vectors.
+ */
+IGnssConfiguration::BlacklistedSource FindStrongFrequentNonGpsSource(
+        const std::list<hidl_vec<IGnssCallback_2_1::GnssSvInfo>> sv_info_list,
+        const int min_observations) {
+    struct ComparableBlacklistedSource {
+        IGnssConfiguration::BlacklistedSource id;
+
+        ComparableBlacklistedSource() {
+            id.constellation = GnssConstellationType::UNKNOWN;
+            id.svid = 0;
+        }
+
+        bool operator<(const ComparableBlacklistedSource& compare) const {
+            return ((id.svid < compare.id.svid) || ((id.svid == compare.id.svid) &&
+                                                    (id.constellation < compare.id.constellation)));
+        }
+    };
+
+    struct SignalCounts {
+        int observations;
+        float max_cn0_dbhz;
+    };
+
+    std::map<ComparableBlacklistedSource, SignalCounts> mapSignals;
+
+    for (const auto& sv_info_vec : sv_info_list) {
+        for (uint32_t iSv = 0; iSv < sv_info_vec.size(); iSv++) {
+            const auto& gnss_sv = sv_info_vec[iSv];
+            if ((gnss_sv.v2_0.v1_0.svFlag & IGnssCallback_1_0::GnssSvFlags::USED_IN_FIX) &&
+                (gnss_sv.v2_0.constellation != GnssConstellationType::GPS)) {
+                ComparableBlacklistedSource source;
+                source.id.svid = gnss_sv.v2_0.v1_0.svid;
+                source.id.constellation = gnss_sv.v2_0.constellation;
+
+                const auto& itSignal = mapSignals.find(source);
+                if (itSignal == mapSignals.end()) {
+                    SignalCounts counts;
+                    counts.observations = 1;
+                    counts.max_cn0_dbhz = gnss_sv.v2_0.v1_0.cN0Dbhz;
+                    mapSignals.insert(
+                            std::pair<ComparableBlacklistedSource, SignalCounts>(source, counts));
+                } else {
+                    itSignal->second.observations++;
+                    if (itSignal->second.max_cn0_dbhz < gnss_sv.v2_0.v1_0.cN0Dbhz) {
+                        itSignal->second.max_cn0_dbhz = gnss_sv.v2_0.v1_0.cN0Dbhz;
+                    }
+                }
+            }
+        }
+    }
+
+    float max_cn0_dbhz_with_sufficient_count = 0.;
+    int total_observation_count = 0;
+    int blacklisted_source_count_observation = 0;
+
+    ComparableBlacklistedSource source_to_blacklist;  // initializes to zero = UNKNOWN constellation
+    for (auto const& pairSignal : mapSignals) {
+        total_observation_count += pairSignal.second.observations;
+        if ((pairSignal.second.observations >= min_observations) &&
+            (pairSignal.second.max_cn0_dbhz > max_cn0_dbhz_with_sufficient_count)) {
+            source_to_blacklist = pairSignal.first;
+            blacklisted_source_count_observation = pairSignal.second.observations;
+            max_cn0_dbhz_with_sufficient_count = pairSignal.second.max_cn0_dbhz;
+        }
+    }
+    ALOGD("Among %d observations, chose svid %d, constellation %d, "
+          "with %d observations at %.1f max CNo",
+          total_observation_count, source_to_blacklist.id.svid,
+          (int)source_to_blacklist.id.constellation, blacklisted_source_count_observation,
+          max_cn0_dbhz_with_sufficient_count);
+
+    return source_to_blacklist.id;
+}
+
+/*
+ * BlacklistIndividualSatellites:
+ *
+ * 1) Turns on location, waits for 3 locations, ensuring they are valid, and checks corresponding
+ * GnssStatus for common satellites (strongest and one other.)
+ * 2a & b) Turns off location, and blacklists common satellites.
+ * 3) Restart location, wait for 3 locations, ensuring they are valid, and checks corresponding
+ * GnssStatus does not use those satellites.
+ * 4a & b) Turns off location, and send in empty blacklist.
+ * 5a) Restart location, wait for 3 locations, ensuring they are valid, and checks corresponding
+ * GnssStatus does re-use at least the previously strongest satellite
+ * 5b) Retry a few times, in case GNSS search strategy takes a while to reacquire even the
+ * formerly strongest satellite
+ */
+TEST_P(GnssHalTest, BlacklistIndividualSatellites) {
+    const int kLocationsToAwait = 3;
+    const int kRetriesToUnBlacklist = 10;
+
+    gnss_cb_->location_cbq_.reset();
+    StartAndCheckLocations(kLocationsToAwait);
+    int location_called_count = gnss_cb_->location_cbq_.calledCount();
+
+    // Tolerate 1 less sv status to handle edge cases in reporting.
+    int sv_info_list_cbq_size = gnss_cb_->sv_info_list_cbq_.size();
+    EXPECT_GE(sv_info_list_cbq_size + 1, kLocationsToAwait);
+    ALOGD("Observed %d GnssSvInfo, while awaiting %d Locations (%d received)",
+          sv_info_list_cbq_size, kLocationsToAwait, location_called_count);
+
+    /*
+     * Identify strongest SV seen at least kLocationsToAwait -1 times
+     * Why -1?  To avoid test flakiness in case of (plausible) slight flakiness in strongest signal
+     * observability (one epoch RF null)
+     */
+
+    const int kGnssSvInfoListTimeout = 2;
+    std::list<hidl_vec<IGnssCallback_2_1::GnssSvInfo>> sv_info_vec_list;
+    int count = gnss_cb_->sv_info_list_cbq_.retrieve(sv_info_vec_list, sv_info_list_cbq_size,
+                                                     kGnssSvInfoListTimeout);
+
+    ASSERT_EQ(count, sv_info_list_cbq_size);
+
+    IGnssConfiguration::BlacklistedSource source_to_blacklist =
+            FindStrongFrequentNonGpsSource(sv_info_vec_list, kLocationsToAwait - 1);
+
+    if (source_to_blacklist.constellation == GnssConstellationType::UNKNOWN) {
+        // Cannot find a non-GPS satellite. Let the test pass.
+        ALOGD("Cannot find a non-GPS satellite. Letting the test pass.");
+        return;
+    }
+
+    // Stop locations, blacklist the common SV
+    StopAndClearLocations();
+
+    auto gnss_configuration_hal_return = gnss_hal_->getExtensionGnssConfiguration_2_1();
+    ASSERT_TRUE(gnss_configuration_hal_return.isOk());
+    sp<IGnssConfiguration> gnss_configuration_hal = gnss_configuration_hal_return;
+    ASSERT_NE(gnss_configuration_hal, nullptr);
+
+    hidl_vec<IGnssConfiguration::BlacklistedSource> sources;
+    sources.resize(1);
+    sources[0] = source_to_blacklist;
+
+    auto result = gnss_configuration_hal->setBlacklist_2_1(sources);
+    ASSERT_TRUE(result.isOk());
+    EXPECT_TRUE(result);
+
+    // retry and ensure satellite not used
+    gnss_cb_->sv_info_list_cbq_.reset();
+
+    gnss_cb_->location_cbq_.reset();
+    StartAndCheckLocations(kLocationsToAwait);
+
+    // early exit if test is being run with insufficient signal
+    location_called_count = gnss_cb_->location_cbq_.calledCount();
+    if (location_called_count == 0) {
+        ALOGE("0 Gnss locations received - ensure sufficient signal and retry");
+    }
+    ASSERT_TRUE(location_called_count > 0);
+
+    // Tolerate 1 less sv status to handle edge cases in reporting.
+    sv_info_list_cbq_size = gnss_cb_->sv_info_list_cbq_.size();
+    EXPECT_GE(sv_info_list_cbq_size + 1, kLocationsToAwait);
+    ALOGD("Observed %d GnssSvInfo, while awaiting %d Locations (%d received)",
+          sv_info_list_cbq_size, kLocationsToAwait, location_called_count);
+    for (int i = 0; i < sv_info_list_cbq_size; ++i) {
+        hidl_vec<IGnssCallback_2_1::GnssSvInfo> sv_info_vec;
+        gnss_cb_->sv_info_list_cbq_.retrieve(sv_info_vec, kGnssSvInfoListTimeout);
+        for (uint32_t iSv = 0; iSv < sv_info_vec.size(); iSv++) {
+            const auto& gnss_sv = sv_info_vec[iSv];
+            EXPECT_FALSE((gnss_sv.v2_0.v1_0.svid == source_to_blacklist.svid) &&
+                         (gnss_sv.v2_0.constellation == source_to_blacklist.constellation) &&
+                         (gnss_sv.v2_0.v1_0.svFlag & IGnssCallback_1_0::GnssSvFlags::USED_IN_FIX));
+        }
+    }
+
+    // clear blacklist and restart - this time updating the blacklist while location is still on
+    sources.resize(0);
+
+    result = gnss_configuration_hal->setBlacklist_2_1(sources);
+    ASSERT_TRUE(result.isOk());
+    EXPECT_TRUE(result);
+
+    bool strongest_sv_is_reobserved = false;
+    // do several loops awaiting a few locations, allowing non-immediate reacquisition strategies
+    int unblacklist_loops_remaining = kRetriesToUnBlacklist;
+    while (!strongest_sv_is_reobserved && (unblacklist_loops_remaining-- > 0)) {
+        StopAndClearLocations();
+        gnss_cb_->sv_info_list_cbq_.reset();
+
+        gnss_cb_->location_cbq_.reset();
+        StartAndCheckLocations(kLocationsToAwait);
+
+        // early exit loop if test is being run with insufficient signal
+        location_called_count = gnss_cb_->location_cbq_.calledCount();
+        if (location_called_count == 0) {
+            ALOGE("0 Gnss locations received - ensure sufficient signal and retry");
+        }
+        ASSERT_TRUE(location_called_count > 0);
+
+        // Tolerate 1 less sv status to handle edge cases in reporting.
+        sv_info_list_cbq_size = gnss_cb_->sv_info_list_cbq_.size();
+        EXPECT_GE(sv_info_list_cbq_size + 1, kLocationsToAwait);
+        ALOGD("Clear blacklist, observed %d GnssSvInfo, while awaiting %d Locations"
+              ", tries remaining %d",
+              sv_info_list_cbq_size, kLocationsToAwait, unblacklist_loops_remaining);
+
+        for (int i = 0; i < sv_info_list_cbq_size; ++i) {
+            hidl_vec<IGnssCallback_2_1::GnssSvInfo> sv_info_vec;
+            gnss_cb_->sv_info_list_cbq_.retrieve(sv_info_vec, kGnssSvInfoListTimeout);
+            for (uint32_t iSv = 0; iSv < sv_info_vec.size(); iSv++) {
+                const auto& gnss_sv = sv_info_vec[iSv];
+                if ((gnss_sv.v2_0.v1_0.svid == source_to_blacklist.svid) &&
+                    (gnss_sv.v2_0.constellation == source_to_blacklist.constellation) &&
+                    (gnss_sv.v2_0.v1_0.svFlag & IGnssCallback_1_0::GnssSvFlags::USED_IN_FIX)) {
+                    strongest_sv_is_reobserved = true;
+                    break;
+                }
+            }
+            if (strongest_sv_is_reobserved) break;
+        }
+    }
+    EXPECT_TRUE(strongest_sv_is_reobserved);
+    StopAndClearLocations();
+}
+
+/*
+ * BlacklistConstellation:
+ *
+ * 1) Turns on location, waits for 3 locations, ensuring they are valid, and checks corresponding
+ * GnssStatus for any non-GPS constellations.
+ * 2a & b) Turns off location, and blacklist first non-GPS constellations.
+ * 3) Restart location, wait for 3 locations, ensuring they are valid, and checks corresponding
+ * GnssStatus does not use any constellation but GPS.
+ * 4a & b) Clean up by turning off location, and send in empty blacklist.
+ */
+TEST_P(GnssHalTest, BlacklistConstellation) {
+    const int kLocationsToAwait = 3;
+
+    gnss_cb_->location_cbq_.reset();
+    StartAndCheckLocations(kLocationsToAwait);
+    const int location_called_count = gnss_cb_->location_cbq_.calledCount();
+
+    // Tolerate 1 less sv status to handle edge cases in reporting.
+    int sv_info_list_cbq_size = gnss_cb_->sv_info_list_cbq_.size();
+    EXPECT_GE(sv_info_list_cbq_size + 1, kLocationsToAwait);
+    ALOGD("Observed %d GnssSvInfo, while awaiting %d Locations (%d received)",
+          sv_info_list_cbq_size, kLocationsToAwait, location_called_count);
+
+    // Find first non-GPS constellation to blacklist
+    const int kGnssSvInfoListTimeout = 2;
+    GnssConstellationType constellation_to_blacklist = GnssConstellationType::UNKNOWN;
+    for (int i = 0; i < sv_info_list_cbq_size; ++i) {
+        hidl_vec<IGnssCallback_2_1::GnssSvInfo> sv_info_vec;
+        gnss_cb_->sv_info_list_cbq_.retrieve(sv_info_vec, kGnssSvInfoListTimeout);
+        for (uint32_t iSv = 0; iSv < sv_info_vec.size(); iSv++) {
+            const auto& gnss_sv = sv_info_vec[iSv];
+            if ((gnss_sv.v2_0.v1_0.svFlag & IGnssCallback_1_0::GnssSvFlags::USED_IN_FIX) &&
+                (gnss_sv.v2_0.constellation != GnssConstellationType::UNKNOWN) &&
+                (gnss_sv.v2_0.constellation != GnssConstellationType::GPS)) {
+                // found a non-GPS constellation
+                constellation_to_blacklist = gnss_sv.v2_0.constellation;
+                break;
+            }
+        }
+        if (constellation_to_blacklist != GnssConstellationType::UNKNOWN) {
+            break;
+        }
+    }
+
+    // Turns off location
+    StopAndClearLocations();
+
+    if (constellation_to_blacklist == GnssConstellationType::UNKNOWN) {
+        ALOGI("No non-GPS constellations found, constellation blacklist test less effective.");
+        // Proceed functionally to blacklist something.
+        constellation_to_blacklist = GnssConstellationType::GLONASS;
+    }
+    IGnssConfiguration::BlacklistedSource source_to_blacklist_1;
+    source_to_blacklist_1.constellation = constellation_to_blacklist;
+    source_to_blacklist_1.svid = 0;  // documented wildcard for all satellites in this constellation
+
+    // IRNSS was added in 2.0. Always attempt to blacklist IRNSS to verify that the new enum is
+    // supported.
+    IGnssConfiguration::BlacklistedSource source_to_blacklist_2;
+    source_to_blacklist_2.constellation = GnssConstellationType::IRNSS;
+    source_to_blacklist_2.svid = 0;  // documented wildcard for all satellites in this constellation
+
+    auto gnss_configuration_hal_return = gnss_hal_->getExtensionGnssConfiguration_2_1();
+    ASSERT_TRUE(gnss_configuration_hal_return.isOk());
+    sp<IGnssConfiguration> gnss_configuration_hal = gnss_configuration_hal_return;
+    ASSERT_NE(gnss_configuration_hal, nullptr);
+
+    hidl_vec<IGnssConfiguration::BlacklistedSource> sources;
+    sources.resize(2);
+    sources[0] = source_to_blacklist_1;
+    sources[1] = source_to_blacklist_2;
+
+    auto result = gnss_configuration_hal->setBlacklist_2_1(sources);
+    ASSERT_TRUE(result.isOk());
+    EXPECT_TRUE(result);
+
+    // retry and ensure constellation not used
+    gnss_cb_->sv_info_list_cbq_.reset();
+
+    gnss_cb_->location_cbq_.reset();
+    StartAndCheckLocations(kLocationsToAwait);
+
+    // Tolerate 1 less sv status to handle edge cases in reporting.
+    sv_info_list_cbq_size = gnss_cb_->sv_info_list_cbq_.size();
+    EXPECT_GE(sv_info_list_cbq_size + 1, kLocationsToAwait);
+    ALOGD("Observed %d GnssSvInfo, while awaiting %d Locations", sv_info_list_cbq_size,
+          kLocationsToAwait);
+    for (int i = 0; i < sv_info_list_cbq_size; ++i) {
+        hidl_vec<IGnssCallback_2_1::GnssSvInfo> sv_info_vec;
+        gnss_cb_->sv_info_list_cbq_.retrieve(sv_info_vec, kGnssSvInfoListTimeout);
+        for (uint32_t iSv = 0; iSv < sv_info_vec.size(); iSv++) {
+            const auto& gnss_sv = sv_info_vec[iSv];
+            EXPECT_FALSE((gnss_sv.v2_0.constellation == source_to_blacklist_1.constellation) &&
+                         (gnss_sv.v2_0.v1_0.svFlag & IGnssCallback_1_0::GnssSvFlags::USED_IN_FIX));
+            EXPECT_FALSE((gnss_sv.v2_0.constellation == source_to_blacklist_2.constellation) &&
+                         (gnss_sv.v2_0.v1_0.svFlag & IGnssCallback_1_0::GnssSvFlags::USED_IN_FIX));
+        }
+    }
+
+    // clean up
+    StopAndClearLocations();
+    sources.resize(0);
+    result = gnss_configuration_hal->setBlacklist_2_1(sources);
+    ASSERT_TRUE(result.isOk());
+    EXPECT_TRUE(result);
+}
\ No newline at end of file
diff --git a/gnss/common/utils/default/Utils.cpp b/gnss/common/utils/default/Utils.cpp
index 6c6d696..ccb91b1 100644
--- a/gnss/common/utils/default/Utils.cpp
+++ b/gnss/common/utils/default/Utils.cpp
@@ -175,6 +175,11 @@
                                                         25.0, 66.0, 247.0),
                                       V2_0::GnssConstellationType::GLONASS),
                     20.0),
+            getMockSvInfoV2_1(
+                    getMockSvInfoV2_0(getMockSvInfoV1_0(3, V1_0::GnssConstellationType::UNKNOWN,
+                                                        22.0, 35.0, 112.0),
+                                      V2_0::GnssConstellationType::IRNSS),
+                    19.7),
     };
     return gnssSvInfoList;
 }