diff --git a/automotive/vehicle/2.0/default/Android.bp b/automotive/vehicle/2.0/default/Android.bp
index 8bf6bbe..2c3422e 100644
--- a/automotive/vehicle/2.0/default/Android.bp
+++ b/automotive/vehicle/2.0/default/Android.bp
@@ -97,6 +97,7 @@
     local_include_dirs: ["common/include/vhal_v2_0"],
     export_include_dirs: ["impl"],
     whole_static_libs: [
+        "android.hardware.automotive.vehicle@2.0-emulated-user-hal-lib",
         "android.hardware.automotive.vehicle@2.0-manager-lib",
     ],
     shared_libs: [
@@ -215,8 +216,8 @@
         "android.hardware.automotive.vehicle@2.0-libproto-native",
     ],
     data: [
-        ":vhal_test_override_json",
         ":vhal_test_json",
+        ":vhal_test_override_json",
     ],
     test_suites: ["general-tests"],
 }
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.cpp b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.cpp
index 74337b8..25a698b 100644
--- a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.cpp
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.cpp
@@ -89,11 +89,38 @@
             });
 }
 
+VehicleHal::VehiclePropValuePtr DefaultVehicleHal::getUserHalProp(
+        const VehiclePropValue& requestedPropValue, StatusCode* outStatus) {
+    auto propId = requestedPropValue.prop;
+    ALOGI("get(): getting value for prop %d from User HAL", propId);
+    const auto& ret = mEmulatedUserHal.onGetProperty(requestedPropValue);
+    VehicleHal::VehiclePropValuePtr v = nullptr;
+    if (!ret.ok()) {
+        ALOGE("get(): User HAL returned error: %s", ret.error().message().c_str());
+        *outStatus = StatusCode(ret.error().code());
+    } else {
+        auto value = ret.value().get();
+        if (value != nullptr) {
+            ALOGI("get(): User HAL returned value: %s", toString(*value).c_str());
+            v = getValuePool()->obtain(*value);
+            *outStatus = StatusCode::OK;
+        } else {
+            ALOGE("get(): User HAL returned null value");
+            *outStatus = StatusCode::INTERNAL_ERROR;
+        }
+    }
+    return addTimestamp(std::move(v));
+}
+
 VehicleHal::VehiclePropValuePtr DefaultVehicleHal::get(const VehiclePropValue& requestedPropValue,
                                                        StatusCode* outStatus) {
     auto propId = requestedPropValue.prop;
     ALOGV("get(%d)", propId);
 
+    if (mEmulatedUserHal.isSupported(propId)) {
+        return getUserHalProp(requestedPropValue, outStatus);
+    }
+
     VehiclePropValuePtr v = nullptr;
     if (propId == OBD2_FREEZE_FRAME) {
         v = getValuePool()->obtainComplex();
@@ -127,6 +154,36 @@
 }
 
 bool DefaultVehicleHal::dump(const hidl_handle& fd, const hidl_vec<hidl_string>& options) {
+    int nativeFd = fd->data[0];
+    if (nativeFd < 0) {
+        ALOGW("Invalid fd from HIDL handle: %d", nativeFd);
+        return false;
+    }
+    if (options.size() > 0) {
+        if (options[0] == "--help") {
+            std::string buffer;
+            buffer += "Emulated user hal usage:\n";
+            buffer += mEmulatedUserHal.showDumpHelp();
+            buffer += "\n";
+            buffer += "VHAL server debug usage:\n";
+            buffer += "--debughal: send debug command to VHAL server, see '--debughal --help'\n";
+            buffer += "\n";
+            dprintf(nativeFd, "%s", buffer.c_str());
+            return false;
+        } else if (options[0] == kUserHalDumpOption) {
+            dprintf(nativeFd, "%s", mEmulatedUserHal.dump("").c_str());
+            return false;
+        }
+    } else {
+        // No options, dump the emulated user hal state first and then send command to VHAL server
+        // to dump its state.
+        std::string buffer;
+        buffer += "Emulator user hal state:\n";
+        buffer += mEmulatedUserHal.dump("  ");
+        buffer += "\n";
+        dprintf(nativeFd, "%s", buffer.c_str());
+    }
+
     return mVehicleClient->dump(fd, options);
 }
 
@@ -285,6 +342,23 @@
     return StatusCode::OK;
 }
 
+StatusCode DefaultVehicleHal::setUserHalProp(const VehiclePropValue& propValue) {
+    ALOGI("onSetProperty(): property %d will be handled by UserHal", propValue.prop);
+
+    const auto& ret = mEmulatedUserHal.onSetProperty(propValue);
+    if (!ret.ok()) {
+        ALOGE("onSetProperty(): HAL returned error: %s", ret.error().message().c_str());
+        return StatusCode(ret.error().code());
+    }
+    auto updatedValue = ret.value().get();
+    if (updatedValue != nullptr) {
+        ALOGI("onSetProperty(): updating property returned by HAL: %s",
+              toString(*updatedValue).c_str());
+        onPropertyValue(*updatedValue, true);
+    }
+    return StatusCode::OK;
+}
+
 StatusCode DefaultVehicleHal::set(const VehiclePropValue& propValue) {
     if (propValue.status != VehiclePropertyStatus::AVAILABLE) {
         // Android side cannot set property status - this value is the
@@ -293,6 +367,10 @@
         return StatusCode::INVALID_ARG;
     }
 
+    if (mEmulatedUserHal.isSupported(propValue.prop)) {
+        return setUserHalProp(propValue);
+    }
+
     std::unordered_set<int32_t> powerProps(std::begin(kHvacPowerProperties),
                                            std::end(kHvacPowerProperties));
     if (powerProps.count(propValue.prop)) {
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.h b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.h
index 027dc85..7cd7ac2 100644
--- a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.h
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultVehicleHal.h
@@ -21,6 +21,7 @@
 #include <vhal_v2_0/VehicleHal.h>
 #include <vhal_v2_0/VehiclePropertyStore.h>
 
+#include "EmulatedUserHal.h"
 #include "VehicleHalClient.h"
 
 namespace android {
@@ -55,6 +56,7 @@
     VehiclePropertyStore* mPropStore;
     RecurrentTimer mRecurrentTimer;
     VehicleHalClient* mVehicleClient;
+    EmulatedUserHal mEmulatedUserHal;
 
     // The callback that would be called when a property value is updated. This function could
     // be extended to handle specific property update event.
@@ -79,6 +81,11 @@
     // Register the heart beat event to be sent every 3s. This is required to inform watch dog that
     // VHAL is alive. Subclasses should always calls this function during onCreate.
     void registerHeartBeatEvent();
+    // Get a user HAL property.
+    VehiclePropValuePtr getUserHalProp(const VehiclePropValue& requestedPropValue,
+                                       StatusCode* outStatus);
+    // Set a user HAL property.
+    StatusCode setUserHalProp(const VehiclePropValue& propValue);
     // Create a VHAL heart beat property.
     VehicleHal::VehiclePropValuePtr createVhalHeartBeatProp();
 
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/tests/DefaultVhalImpl_test.cpp b/automotive/vehicle/2.0/default/impl/vhal_v2_0/tests/DefaultVhalImpl_test.cpp
index 27c1f4d..2268df8 100644
--- a/automotive/vehicle/2.0/default/impl/vhal_v2_0/tests/DefaultVhalImpl_test.cpp
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/tests/DefaultVhalImpl_test.cpp
@@ -1047,4 +1047,220 @@
     ASSERT_EQ(StatusCode::INVALID_ARG, status);
 }
 
+TEST_F(DefaultVhalImplTest, testGetUserPropertySetOnly) {
+    VehiclePropValue value;
+    value.prop = toInt(VehicleProperty::INITIAL_USER_INFO);
+    StatusCode status;
+
+    mHal->get(value, &status);
+
+    ASSERT_EQ(StatusCode::INVALID_ARG, status);
+
+    value.prop = toInt(VehicleProperty::SWITCH_USER);
+
+    mHal->get(value, &status);
+
+    ASSERT_EQ(StatusCode::INVALID_ARG, status);
+
+    value.prop = toInt(VehicleProperty::CREATE_USER);
+
+    mHal->get(value, &status);
+
+    ASSERT_EQ(StatusCode::INVALID_ARG, status);
+
+    value.prop = toInt(VehicleProperty::REMOVE_USER);
+
+    mHal->get(value, &status);
+
+    ASSERT_EQ(StatusCode::INVALID_ARG, status);
+}
+
+TEST_F(DefaultVhalImplTest, testGetUserIdAssoc) {
+    VehiclePropValue value;
+    value.prop = toInt(VehicleProperty::USER_IDENTIFICATION_ASSOCIATION);
+    StatusCode status;
+
+    mHal->get(value, &status);
+
+    // Default returns NOT_AVAILABLE.
+    ASSERT_EQ(StatusCode::NOT_AVAILABLE, status);
+
+    // This is the same example as used in User HAL Emulation doc.
+    VehiclePropValue setValue = {
+            .prop = toInt(VehicleProperty::USER_IDENTIFICATION_ASSOCIATION),
+            .areaId = 1,
+            .value.int32Values = {666, 1, 1, 2},
+    };
+
+    status = mHal->set(setValue);
+
+    ASSERT_EQ(StatusCode::OK, status);
+
+    auto gotValue = mHal->get(value, &status);
+
+    ASSERT_EQ(StatusCode::OK, status);
+    ASSERT_EQ((size_t)4, gotValue->value.int32Values.size());
+    EXPECT_EQ(1, gotValue->areaId);
+    EXPECT_EQ(666, gotValue->value.int32Values[0]);
+    EXPECT_EQ(1, gotValue->value.int32Values[1]);
+    EXPECT_EQ(1, gotValue->value.int32Values[2]);
+    EXPECT_EQ(2, gotValue->value.int32Values[3]);
+    EXPECT_EQ(toInt(VehicleProperty::USER_IDENTIFICATION_ASSOCIATION), gotValue->prop);
+}
+
+TEST_F(DefaultVhalImplTest, testSwitchUser) {
+    // This is the same example as used in User HAL Emulation doc.
+    VehiclePropValue setValue = {
+            .prop = toInt(VehicleProperty::SWITCH_USER),
+            .areaId = 1,
+            .value.int32Values = {666, 3, 2},
+    };
+
+    auto status = mHal->set(setValue);
+
+    ASSERT_EQ(StatusCode::OK, status);
+
+    // Simulate a request from Android side.
+    setValue = {
+            .prop = toInt(VehicleProperty::SWITCH_USER),
+            .areaId = 0,
+            .value.int32Values = {666, 3},
+    };
+    // Clear existing events.
+    mEventQueue.flush();
+
+    status = mHal->set(setValue);
+
+    ASSERT_EQ(StatusCode::OK, status);
+
+    // Should generate an event for user hal response.
+    auto events = mEventQueue.flush();
+    ASSERT_EQ((size_t)1, events.size());
+    EXPECT_EQ(1, events[0]->areaId);
+    EXPECT_EQ(toInt(VehicleProperty::SWITCH_USER), events[0]->prop);
+    ASSERT_EQ((size_t)3, events[0]->value.int32Values.size());
+    EXPECT_EQ(666, events[0]->value.int32Values[0]);
+    EXPECT_EQ(3, events[0]->value.int32Values[1]);
+    EXPECT_EQ(2, events[0]->value.int32Values[2]);
+
+    // Try to get switch_user again, should return default value.
+    status = mHal->set(setValue);
+    ASSERT_EQ(StatusCode::OK, status);
+
+    events = mEventQueue.flush();
+    ASSERT_EQ((size_t)1, events.size());
+    EXPECT_EQ(0, events[0]->areaId);
+    EXPECT_EQ(toInt(VehicleProperty::SWITCH_USER), events[0]->prop);
+    ASSERT_EQ((size_t)3, events[0]->value.int32Values.size());
+    // Request ID
+    EXPECT_EQ(666, events[0]->value.int32Values[0]);
+    // VEHICLE_RESPONSE
+    EXPECT_EQ(3, events[0]->value.int32Values[1]);
+    // SUCCESS
+    EXPECT_EQ(1, events[0]->value.int32Values[2]);
+}
+
+TEST_F(DefaultVhalImplTest, testCreateUser) {
+    // This is the same example as used in User HAL Emulation doc.
+    VehiclePropValue setValue = {
+            .prop = toInt(VehicleProperty::CREATE_USER),
+            .areaId = 1,
+            .value.int32Values = {666, 2},
+    };
+
+    auto status = mHal->set(setValue);
+
+    ASSERT_EQ(StatusCode::OK, status);
+
+    // Simulate a request from Android side.
+    setValue = {
+            .prop = toInt(VehicleProperty::CREATE_USER),
+            .areaId = 0,
+            .value.int32Values = {666},
+    };
+    // Clear existing events.
+    mEventQueue.flush();
+
+    status = mHal->set(setValue);
+
+    ASSERT_EQ(StatusCode::OK, status);
+
+    // Should generate an event for user hal response.
+    auto events = mEventQueue.flush();
+    ASSERT_EQ((size_t)1, events.size());
+    EXPECT_EQ(1, events[0]->areaId);
+    EXPECT_EQ(toInt(VehicleProperty::CREATE_USER), events[0]->prop);
+    ASSERT_EQ((size_t)2, events[0]->value.int32Values.size());
+    EXPECT_EQ(666, events[0]->value.int32Values[0]);
+    EXPECT_EQ(2, events[0]->value.int32Values[1]);
+
+    // Try to get create_user again, should return default value.
+    status = mHal->set(setValue);
+    ASSERT_EQ(StatusCode::OK, status);
+
+    events = mEventQueue.flush();
+    ASSERT_EQ((size_t)1, events.size());
+    EXPECT_EQ(0, events[0]->areaId);
+    EXPECT_EQ(toInt(VehicleProperty::CREATE_USER), events[0]->prop);
+    ASSERT_EQ((size_t)2, events[0]->value.int32Values.size());
+    // Request ID
+    EXPECT_EQ(666, events[0]->value.int32Values[0]);
+    // SUCCESS
+    EXPECT_EQ(1, events[0]->value.int32Values[1]);
+}
+
+TEST_F(DefaultVhalImplTest, testInitialUserInfo) {
+    // This is the same example as used in User HAL Emulation doc.
+    VehiclePropValue setValue = {
+            .prop = toInt(VehicleProperty::INITIAL_USER_INFO),
+            .areaId = 1,
+            .value.int32Values = {666, 1, 11},
+    };
+
+    auto status = mHal->set(setValue);
+
+    ASSERT_EQ(StatusCode::OK, status);
+
+    // Simulate a request from Android side.
+    setValue = {
+            .prop = toInt(VehicleProperty::INITIAL_USER_INFO),
+            .areaId = 0,
+            .value.int32Values = {3},
+    };
+    // Clear existing events.
+    mEventQueue.flush();
+
+    status = mHal->set(setValue);
+
+    ASSERT_EQ(StatusCode::OK, status);
+
+    // Should generate an event for user hal response.
+    auto events = mEventQueue.flush();
+    ASSERT_EQ((size_t)1, events.size());
+    EXPECT_EQ(1, events[0]->areaId);
+    EXPECT_EQ(toInt(VehicleProperty::INITIAL_USER_INFO), events[0]->prop);
+    ASSERT_EQ((size_t)3, events[0]->value.int32Values.size());
+    EXPECT_EQ(3, events[0]->value.int32Values[0]);
+    EXPECT_EQ(1, events[0]->value.int32Values[1]);
+    EXPECT_EQ(11, events[0]->value.int32Values[2]);
+
+    // Try to get create_user again, should return default value.
+    status = mHal->set(setValue);
+    ASSERT_EQ(StatusCode::OK, status);
+
+    events = mEventQueue.flush();
+    ASSERT_EQ((size_t)1, events.size());
+    EXPECT_EQ(0, events[0]->areaId);
+    EXPECT_EQ(toInt(VehicleProperty::INITIAL_USER_INFO), events[0]->prop);
+    ASSERT_EQ((size_t)4, events[0]->value.int32Values.size());
+    // Request ID
+    EXPECT_EQ(3, events[0]->value.int32Values[0]);
+    // ACTION: DEFAULT
+    EXPECT_EQ(0, events[0]->value.int32Values[1]);
+    // User id: 0
+    EXPECT_EQ(0, events[0]->value.int32Values[2]);
+    // Flags: 0
+    EXPECT_EQ(0, events[0]->value.int32Values[3]);
+}
+
 }  // namespace
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/Android.bp b/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/Android.bp
new file mode 100644
index 0000000..0058d33
--- /dev/null
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/Android.bp
@@ -0,0 +1,31 @@
+// Copyright (C) 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.
+
+// Library used to emulate User HAL behavior through lshal debug requests.
+cc_library {
+    name: "android.hardware.automotive.vehicle@2.0-emulated-user-hal-lib",
+    vendor: true,
+    defaults: ["vhal_v2_0_target_defaults"],
+    srcs: ["EmulatedUserHal.cpp"],
+    shared_libs: [
+        "libbase",
+        "libutils",
+        "libcutils",
+    ],
+    local_include_dirs: ["include"],
+    export_include_dirs: ["include"],
+    whole_static_libs: [
+        "android.hardware.automotive.vehicle@2.0-user-hal-helper-lib",
+    ],
+}
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/EmulatedUserHal.cpp b/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/EmulatedUserHal.cpp
new file mode 100644
index 0000000..55dc01a
--- /dev/null
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/EmulatedUserHal.cpp
@@ -0,0 +1,353 @@
+/*
+ * Copyright (C) 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.
+ */
+#define LOG_TAG "EmulatedUserHal"
+
+#include <cutils/log.h>
+#include <utils/SystemClock.h>
+
+#include "UserHalHelper.h"
+
+#include "EmulatedUserHal.h"
+
+namespace android {
+namespace hardware {
+namespace automotive {
+namespace vehicle {
+namespace V2_0 {
+
+namespace impl {
+
+namespace {
+
+using android::base::Error;
+using android::base::Result;
+
+constexpr int32_t INITIAL_USER_INFO = static_cast<int32_t>(VehicleProperty::INITIAL_USER_INFO);
+constexpr int32_t SWITCH_USER = static_cast<int32_t>(VehicleProperty::SWITCH_USER);
+constexpr int32_t CREATE_USER = static_cast<int32_t>(VehicleProperty::CREATE_USER);
+constexpr int32_t REMOVE_USER = static_cast<int32_t>(VehicleProperty::REMOVE_USER);
+constexpr int32_t USER_IDENTIFICATION_ASSOCIATION =
+        static_cast<int32_t>(VehicleProperty::USER_IDENTIFICATION_ASSOCIATION);
+
+Result<int32_t> getRequestId(const VehiclePropValue& value) {
+    if (value.value.int32Values.size() < 1) {
+        return Error(static_cast<int>(StatusCode::INVALID_ARG))
+               << "no int32values on " << toString(value);
+    }
+    return value.value.int32Values[0];
+}
+
+Result<SwitchUserMessageType> getSwitchUserMessageType(const VehiclePropValue& value) {
+    if (value.value.int32Values.size() < 2) {
+        return Error(static_cast<int>(StatusCode::INVALID_ARG))
+               << "missing switch user message type " << toString(value);
+    }
+    return user_hal_helper::verifyAndCast<SwitchUserMessageType>(value.value.int32Values[1]);
+}
+
+}  // namespace
+
+bool EmulatedUserHal::isSupported(int32_t prop) {
+    switch (prop) {
+        case INITIAL_USER_INFO:
+        case SWITCH_USER:
+        case CREATE_USER:
+        case REMOVE_USER:
+        case USER_IDENTIFICATION_ASSOCIATION:
+            return true;
+        default:
+            return false;
+    }
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::onSetProperty(
+        const VehiclePropValue& value) {
+    ALOGV("onSetProperty(): %s", toString(value).c_str());
+
+    switch (value.prop) {
+        case INITIAL_USER_INFO:
+            return onSetInitialUserInfoResponse(value);
+        case SWITCH_USER:
+            return onSetSwitchUserResponse(value);
+        case CREATE_USER:
+            return onSetCreateUserResponse(value);
+        case REMOVE_USER:
+            ALOGI("REMOVE_USER is FYI only, nothing to do...");
+            return {};
+        case USER_IDENTIFICATION_ASSOCIATION:
+            return onSetUserIdentificationAssociation(value);
+        default:
+            return Error(static_cast<int>(StatusCode::INVALID_ARG))
+                   << "Unsupported property: " << toString(value);
+    }
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::onGetProperty(
+        const VehiclePropValue& value) {
+    ALOGV("onGetProperty(%s)", toString(value).c_str());
+    switch (value.prop) {
+        case INITIAL_USER_INFO:
+        case SWITCH_USER:
+        case CREATE_USER:
+        case REMOVE_USER:
+            ALOGE("onGetProperty(): %d is only supported on SET", value.prop);
+            return Error(static_cast<int>(StatusCode::INVALID_ARG)) << "only supported on SET";
+        case USER_IDENTIFICATION_ASSOCIATION:
+            return onGetUserIdentificationAssociation(value);
+        default:
+            ALOGE("onGetProperty(): %d is not supported", value.prop);
+            return Error(static_cast<int>(StatusCode::INVALID_ARG)) << "not supported by User HAL";
+    }
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::onGetUserIdentificationAssociation(
+        const VehiclePropValue& value) {
+    if (mSetUserIdentificationAssociationResponseFromCmd == nullptr) {
+        return defaultUserIdentificationAssociation(value);
+    }
+    ALOGI("get(USER_IDENTIFICATION_ASSOCIATION): returning %s",
+          toString(*mSetUserIdentificationAssociationResponseFromCmd).c_str());
+    auto newValue = std::unique_ptr<VehiclePropValue>(
+            new VehiclePropValue(*mSetUserIdentificationAssociationResponseFromCmd));
+    auto requestId = getRequestId(value);
+    if (requestId.ok()) {
+        // Must use the same requestId
+        newValue->value.int32Values[0] = *requestId;
+    } else {
+        ALOGE("get(USER_IDENTIFICATION_ASSOCIATION): no requestId on %s", toString(value).c_str());
+    }
+    return newValue;
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::onSetInitialUserInfoResponse(
+        const VehiclePropValue& value) {
+    auto requestId = getRequestId(value);
+    if (!requestId.ok()) {
+        ALOGE("Failed to get requestId on set(INITIAL_USER_INFO): %s",
+              requestId.error().message().c_str());
+        return requestId.error();
+    }
+
+    if (value.areaId != 0) {
+        ALOGD("set(INITIAL_USER_INFO) called from lshal; storing it: %s", toString(value).c_str());
+        mInitialUserResponseFromCmd.reset(new VehiclePropValue(value));
+        return {};
+    }
+
+    ALOGD("set(INITIAL_USER_INFO) called from Android: %s", toString(value).c_str());
+    if (mInitialUserResponseFromCmd != nullptr) {
+        ALOGI("replying INITIAL_USER_INFO with lshal value:  %s",
+              toString(*mInitialUserResponseFromCmd).c_str());
+        return sendUserHalResponse(std::move(mInitialUserResponseFromCmd), *requestId);
+    }
+
+    // Returns default response
+    auto updatedValue = user_hal_helper::toVehiclePropValue(InitialUserInfoResponse{
+            .requestId = *requestId,
+            .action = InitialUserInfoResponseAction::DEFAULT,
+    });
+    ALOGI("no lshal response; replying with InitialUserInfoResponseAction::DEFAULT: %s",
+          toString(*updatedValue).c_str());
+    return updatedValue;
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::onSetSwitchUserResponse(
+        const VehiclePropValue& value) {
+    auto requestId = getRequestId(value);
+    if (!requestId.ok()) {
+        ALOGE("Failed to get requestId on set(SWITCH_USER): %s",
+              requestId.error().message().c_str());
+        return requestId.error();
+    }
+
+    auto messageType = getSwitchUserMessageType(value);
+    if (!messageType.ok()) {
+        ALOGE("Failed to get messageType on set(SWITCH_USER): %s",
+              messageType.error().message().c_str());
+        return messageType.error();
+    }
+
+    if (value.areaId != 0) {
+        if (*messageType == SwitchUserMessageType::VEHICLE_REQUEST) {
+            // User HAL can also request a user switch, so we need to check it first
+            ALOGD("set(SWITCH_USER) called from lshal to emulate a vehicle request: %s",
+                  toString(value).c_str());
+            return std::unique_ptr<VehiclePropValue>(new VehiclePropValue(value));
+        }
+        // Otherwise, we store it
+        ALOGD("set(SWITCH_USER) called from lshal; storing it: %s", toString(value).c_str());
+        mSwitchUserResponseFromCmd.reset(new VehiclePropValue(value));
+        return {};
+    }
+    ALOGD("set(SWITCH_USER) called from Android: %s", toString(value).c_str());
+
+    if (mSwitchUserResponseFromCmd != nullptr) {
+        ALOGI("replying SWITCH_USER with lshal value:  %s",
+              toString(*mSwitchUserResponseFromCmd).c_str());
+        return sendUserHalResponse(std::move(mSwitchUserResponseFromCmd), *requestId);
+    }
+
+    if (*messageType == SwitchUserMessageType::LEGACY_ANDROID_SWITCH ||
+        *messageType == SwitchUserMessageType::ANDROID_POST_SWITCH) {
+        ALOGI("request is %s; ignoring it", toString(*messageType).c_str());
+        return {};
+    }
+
+    // Returns default response
+    auto updatedValue = user_hal_helper::toVehiclePropValue(SwitchUserResponse{
+            .requestId = *requestId,
+            .messageType = SwitchUserMessageType::VEHICLE_RESPONSE,
+            .status = SwitchUserStatus::SUCCESS,
+    });
+    ALOGI("no lshal response; replying with VEHICLE_RESPONSE / SUCCESS: %s",
+          toString(*updatedValue).c_str());
+    return updatedValue;
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::onSetCreateUserResponse(
+        const VehiclePropValue& value) {
+    auto requestId = getRequestId(value);
+    if (!requestId.ok()) {
+        ALOGE("Failed to get requestId on set(CREATE_USER): %s",
+              requestId.error().message().c_str());
+        return requestId.error();
+    }
+
+    if (value.areaId != 0) {
+        ALOGD("set(CREATE_USER) called from lshal; storing it: %s", toString(value).c_str());
+        mCreateUserResponseFromCmd.reset(new VehiclePropValue(value));
+        return {};
+    }
+    ALOGD("set(CREATE_USER) called from Android: %s", toString(value).c_str());
+
+    if (mCreateUserResponseFromCmd != nullptr) {
+        ALOGI("replying CREATE_USER with lshal value:  %s",
+              toString(*mCreateUserResponseFromCmd).c_str());
+        return sendUserHalResponse(std::move(mCreateUserResponseFromCmd), *requestId);
+    }
+
+    // Returns default response
+    auto updatedValue = user_hal_helper::toVehiclePropValue(CreateUserResponse{
+            .requestId = *requestId,
+            .status = CreateUserStatus::SUCCESS,
+    });
+    ALOGI("no lshal response; replying with SUCCESS: %s", toString(*updatedValue).c_str());
+    return updatedValue;
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::onSetUserIdentificationAssociation(
+        const VehiclePropValue& value) {
+    auto requestId = getRequestId(value);
+    if (!requestId.ok()) {
+        ALOGE("Failed to get requestId on set(USER_IDENTIFICATION_ASSOCIATION): %s",
+              requestId.error().message().c_str());
+        return requestId.error();
+    }
+
+    if (value.areaId != 0) {
+        ALOGD("set(USER_IDENTIFICATION_ASSOCIATION) called from lshal; storing it: %s",
+              toString(value).c_str());
+        mSetUserIdentificationAssociationResponseFromCmd.reset(new VehiclePropValue(value));
+        return {};
+    }
+    ALOGD("set(USER_IDENTIFICATION_ASSOCIATION) called from Android: %s", toString(value).c_str());
+
+    if (mSetUserIdentificationAssociationResponseFromCmd != nullptr) {
+        ALOGI("replying USER_IDENTIFICATION_ASSOCIATION with lshal value:  %s",
+              toString(*mSetUserIdentificationAssociationResponseFromCmd).c_str());
+        // Not moving response so it can be used on GET requests
+        auto copy = std::unique_ptr<VehiclePropValue>(
+                new VehiclePropValue(*mSetUserIdentificationAssociationResponseFromCmd));
+        return sendUserHalResponse(std::move(copy), *requestId);
+    }
+    // Returns default response
+    return defaultUserIdentificationAssociation(value);
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::defaultUserIdentificationAssociation(
+        const VehiclePropValue& request) {
+    // TODO(b/159498909): return a response with NOT_ASSOCIATED_ANY_USER for all requested types
+    ALOGE("no lshal response for %s; replying with NOT_AVAILABLE", toString(request).c_str());
+    return Error(static_cast<int>(StatusCode::NOT_AVAILABLE)) << "not set by lshal";
+}
+
+Result<std::unique_ptr<VehiclePropValue>> EmulatedUserHal::sendUserHalResponse(
+        std::unique_ptr<VehiclePropValue> response, int32_t requestId) {
+    switch (response->areaId) {
+        case 1:
+            ALOGD("returning response with right request id");
+            response->value.int32Values[0] = requestId;
+            break;
+        case 2:
+            ALOGD("returning response with wrong request id");
+            response->value.int32Values[0] = -requestId;
+            break;
+        case 3:
+            ALOGD("not generating a property change event because of lshal prop: %s",
+                  toString(*response).c_str());
+            return Error(static_cast<int>(StatusCode::NOT_AVAILABLE))
+                   << "not generating a property change event because of lshal prop: "
+                   << toString(*response);
+        default:
+            ALOGE("invalid action on lshal response: %s", toString(*response).c_str());
+            return Error(static_cast<int>(StatusCode::INTERNAL_ERROR))
+                   << "invalid action on lshal response: " << toString(*response);
+    }
+
+    ALOGD("updating property to: %s", toString(*response).c_str());
+    return response;
+}
+
+std::string EmulatedUserHal::showDumpHelp() {
+    return fmt::format("{}: dumps state used for user management\n", kUserHalDumpOption);
+}
+
+std::string EmulatedUserHal::dump(std::string indent) {
+    std::string info;
+    if (mInitialUserResponseFromCmd != nullptr) {
+        info += fmt::format("{}InitialUserInfo response: {}\n", indent.c_str(),
+                            toString(*mInitialUserResponseFromCmd).c_str());
+    } else {
+        info += fmt::format("{}No InitialUserInfo response\n", indent.c_str());
+    }
+    if (mSwitchUserResponseFromCmd != nullptr) {
+        info += fmt::format("{}SwitchUser response: {}\n", indent.c_str(),
+                            toString(*mSwitchUserResponseFromCmd).c_str());
+    } else {
+        info += fmt::format("{}No SwitchUser response\n", indent.c_str());
+    }
+    if (mCreateUserResponseFromCmd != nullptr) {
+        info += fmt::format("{}CreateUser response: {}\n", indent.c_str(),
+                            toString(*mCreateUserResponseFromCmd).c_str());
+    } else {
+        info += fmt::format("{}No CreateUser response\n", indent.c_str());
+    }
+    if (mSetUserIdentificationAssociationResponseFromCmd != nullptr) {
+        info += fmt::format("{}SetUserIdentificationAssociation response: {}\n", indent.c_str(),
+                            toString(*mSetUserIdentificationAssociationResponseFromCmd).c_str());
+    } else {
+        info += fmt::format("{}No SetUserIdentificationAssociation response\n", indent.c_str());
+    }
+    return info;
+}
+
+}  // namespace impl
+
+}  // namespace V2_0
+}  // namespace vehicle
+}  // namespace automotive
+}  // namespace hardware
+}  // namespace android
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/include/EmulatedUserHal.h b/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/include/EmulatedUserHal.h
new file mode 100644
index 0000000..46f6d0f
--- /dev/null
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/userhal/include/EmulatedUserHal.h
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 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.
+ */
+
+#ifndef android_hardware_automotive_vehicle_V2_0_impl_EmulatedUserHal_H_
+#define android_hardware_automotive_vehicle_V2_0_impl_EmulatedUserHal_H_
+
+#include <android-base/format.h>
+#include <android-base/result.h>
+
+#include <android/hardware/automotive/vehicle/2.0/types.h>
+
+namespace android {
+namespace hardware {
+namespace automotive {
+namespace vehicle {
+namespace V2_0 {
+
+namespace impl {
+
+constexpr char kUserHalDumpOption[] = "--user-hal";
+
+/**
+ * Class used to emulate a real User HAL behavior through lshal debug requests.
+ */
+class EmulatedUserHal {
+  public:
+    EmulatedUserHal() {}
+
+    ~EmulatedUserHal() = default;
+
+    /**
+     * Checks if the emulator can handle the property.
+     */
+    bool isSupported(int32_t prop);
+
+    /**
+     * Lets the emulator set the property.
+     *
+     * @return updated property and StatusCode
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> onSetProperty(
+            const VehiclePropValue& value);
+
+    /**
+     * Gets the property value from the emulator.
+     *
+     * @return property value and StatusCode
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> onGetProperty(
+            const VehiclePropValue& value);
+
+    /**
+     * Shows the User HAL emulation help.
+     */
+    std::string showDumpHelp();
+
+    /**
+     * Dump its contents.
+     */
+    std::string dump(std::string indent);
+
+  private:
+    /**
+     * INITIAL_USER_INFO is called by Android when it starts, and it's expecting a property change
+     * indicating what the initial user should be.
+     *
+     * During normal circumstances, the emulator will reply right away, passing a response if
+     * InitialUserInfoResponseAction::DEFAULT (so Android could use its own logic to decide which
+     * user to boot).
+     *
+     * But during development / testing, the behavior can be changed using lshal dump, which must
+     * use the areaId to indicate what should happen next.
+     *
+     * So, the behavior of set(INITIAL_USER_INFO) is:
+     *
+     * - if it has an areaId, store the property into mInitialUserResponseFromCmd (as it was called
+     * by lshal).
+     * - else if mInitialUserResponseFromCmd is not set, return a response with the same request id
+     * and InitialUserInfoResponseAction::DEFAULT
+     * - else the behavior is defined by the areaId on mInitialUserResponseFromCmd:
+     * - if it's 1, reply with mInitialUserResponseFromCmd and the right request id
+     * - if it's 2, reply with mInitialUserResponseFromCmd but a wrong request id (so Android can
+     * test this error scenario)
+     * - if it's 3, then don't send a property change (so Android can emulate a timeout)
+     *
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> onSetInitialUserInfoResponse(
+            const VehiclePropValue& value);
+
+    /**
+     * Used to emulate SWITCH_USER - see onSetInitialUserInfoResponse() for usage.
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> onSetSwitchUserResponse(
+            const VehiclePropValue& value);
+
+    /**
+     * Used to emulate CREATE_USER - see onSetInitialUserInfoResponse() for usage.
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> onSetCreateUserResponse(
+            const VehiclePropValue& value);
+
+    /**
+     * Used to emulate set USER_IDENTIFICATION_ASSOCIATION - see onSetInitialUserInfoResponse() for
+     * usage.
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> onSetUserIdentificationAssociation(
+            const VehiclePropValue& value);
+
+    /**
+     * Used to emulate get USER_IDENTIFICATION_ASSOCIATION - see onSetInitialUserInfoResponse() for
+     * usage.
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> onGetUserIdentificationAssociation(
+            const VehiclePropValue& value);
+
+    /**
+     * Creates a default USER_IDENTIFICATION_ASSOCIATION when it was not set by lshal.
+     */
+    android::base::Result<std::unique_ptr<VehiclePropValue>> defaultUserIdentificationAssociation(
+            const VehiclePropValue& request);
+
+    android::base::Result<std::unique_ptr<VehiclePropValue>> sendUserHalResponse(
+            std::unique_ptr<VehiclePropValue> response, int32_t requestId);
+
+    std::unique_ptr<VehiclePropValue> mInitialUserResponseFromCmd;
+    std::unique_ptr<VehiclePropValue> mSwitchUserResponseFromCmd;
+    std::unique_ptr<VehiclePropValue> mCreateUserResponseFromCmd;
+    std::unique_ptr<VehiclePropValue> mSetUserIdentificationAssociationResponseFromCmd;
+};
+
+}  // namespace impl
+
+}  // namespace V2_0
+}  // namespace vehicle
+}  // namespace automotive
+}  // namespace hardware
+}  // namespace android
+
+#endif  // android_hardware_automotive_vehicle_V2_0_impl_EmulatedUserHal_H_