diff --git a/automotive/vehicle/aidl/impl/default_config/JsonConfigLoader/Android.bp b/automotive/vehicle/aidl/impl/default_config/JsonConfigLoader/Android.bp
index 0a33e5b..28c95ce 100644
--- a/automotive/vehicle/aidl/impl/default_config/JsonConfigLoader/Android.bp
+++ b/automotive/vehicle/aidl/impl/default_config/JsonConfigLoader/Android.bp
@@ -49,6 +49,7 @@
     ],
     cflags: ["-DENABLE_VEHICLE_HAL_TEST_PROPERTIES"],
     shared_libs: ["libjsoncpp"],
+    host_supported: true,
 }
 
 cc_library_headers {
diff --git a/automotive/vehicle/aidl/impl/fake_impl/GeneratorHub/Android.bp b/automotive/vehicle/aidl/impl/fake_impl/GeneratorHub/Android.bp
index ab223d3..a250a47 100644
--- a/automotive/vehicle/aidl/impl/fake_impl/GeneratorHub/Android.bp
+++ b/automotive/vehicle/aidl/impl/fake_impl/GeneratorHub/Android.bp
@@ -32,4 +32,5 @@
     shared_libs: [
         "libjsoncpp",
     ],
+    host_supported: true,
 }
diff --git a/automotive/vehicle/aidl/impl/fake_impl/hardware/Android.bp b/automotive/vehicle/aidl/impl/fake_impl/hardware/Android.bp
index 5fc07c9..6030e15 100644
--- a/automotive/vehicle/aidl/impl/fake_impl/hardware/Android.bp
+++ b/automotive/vehicle/aidl/impl/fake_impl/hardware/Android.bp
@@ -37,6 +37,7 @@
     whole_static_libs: [
         "wakeup_client_protos",
     ],
+    host_supported: true,
 }
 
 cc_defaults {
diff --git a/automotive/vehicle/aidl/impl/fake_impl/hardware/include/FakeVehicleHardware.h b/automotive/vehicle/aidl/impl/fake_impl/hardware/include/FakeVehicleHardware.h
index cd39df1..583e40b 100644
--- a/automotive/vehicle/aidl/impl/fake_impl/hardware/include/FakeVehicleHardware.h
+++ b/automotive/vehicle/aidl/impl/fake_impl/hardware/include/FakeVehicleHardware.h
@@ -206,7 +206,7 @@
             EXCLUDES(mLock);
     // Load the config files in format '*.json' from the directory and parse the config files
     // into a map from property ID to ConfigDeclarations.
-    void loadPropConfigsFromDir(const std::string& dirPath,
+    bool loadPropConfigsFromDir(const std::string& dirPath,
                                 std::unordered_map<int32_t, ConfigDeclaration>* configs);
     // Function to be called when a value change event comes from vehicle bus. In our fake
     // implementation, this function is only called during "--inject-event" dump command.
diff --git a/automotive/vehicle/aidl/impl/fake_impl/hardware/src/FakeVehicleHardware.cpp b/automotive/vehicle/aidl/impl/fake_impl/hardware/src/FakeVehicleHardware.cpp
index c4bcdb3..9b880cd 100644
--- a/automotive/vehicle/aidl/impl/fake_impl/hardware/src/FakeVehicleHardware.cpp
+++ b/automotive/vehicle/aidl/impl/fake_impl/hardware/src/FakeVehicleHardware.cpp
@@ -363,7 +363,12 @@
 
 std::unordered_map<int32_t, ConfigDeclaration> FakeVehicleHardware::loadConfigDeclarations() {
     std::unordered_map<int32_t, ConfigDeclaration> configsByPropId;
-    loadPropConfigsFromDir(mDefaultConfigDir, &configsByPropId);
+    bool defaultConfigLoaded = loadPropConfigsFromDir(mDefaultConfigDir, &configsByPropId);
+    if (!defaultConfigLoaded) {
+        // This cannot work without a valid default config.
+        ALOGE("Failed to load default config, exiting");
+        exit(1);
+    }
     if (UseOverrideConfigDir()) {
         loadPropConfigsFromDir(mOverrideConfigDir, &configsByPropId);
     }
@@ -2378,30 +2383,35 @@
     (*mOnPropertyChangeCallback)(std::move(subscribedUpdatedValues));
 }
 
-void FakeVehicleHardware::loadPropConfigsFromDir(
+bool FakeVehicleHardware::loadPropConfigsFromDir(
         const std::string& dirPath,
         std::unordered_map<int32_t, ConfigDeclaration>* configsByPropId) {
     ALOGI("loading properties from %s", dirPath.c_str());
-    if (auto dir = opendir(dirPath.c_str()); dir != NULL) {
-        std::regex regJson(".*[.]json", std::regex::icase);
-        while (auto f = readdir(dir)) {
-            if (!std::regex_match(f->d_name, regJson)) {
-                continue;
-            }
-            std::string filePath = dirPath + "/" + std::string(f->d_name);
-            ALOGI("loading properties from %s", filePath.c_str());
-            auto result = mLoader.loadPropConfig(filePath);
-            if (!result.ok()) {
-                ALOGE("failed to load config file: %s, error: %s", filePath.c_str(),
-                      result.error().message().c_str());
-                continue;
-            }
-            for (auto& [propId, configDeclaration] : result.value()) {
-                (*configsByPropId)[propId] = std::move(configDeclaration);
-            }
-        }
-        closedir(dir);
+    auto dir = opendir(dirPath.c_str());
+    if (dir == nullptr) {
+        ALOGE("Failed to open config directory: %s", dirPath.c_str());
+        return false;
     }
+
+    std::regex regJson(".*[.]json", std::regex::icase);
+    while (auto f = readdir(dir)) {
+        if (!std::regex_match(f->d_name, regJson)) {
+            continue;
+        }
+        std::string filePath = dirPath + "/" + std::string(f->d_name);
+        ALOGI("loading properties from %s", filePath.c_str());
+        auto result = mLoader.loadPropConfig(filePath);
+        if (!result.ok()) {
+            ALOGE("failed to load config file: %s, error: %s", filePath.c_str(),
+                  result.error().message().c_str());
+            continue;
+        }
+        for (auto& [propId, configDeclaration] : result.value()) {
+            (*configsByPropId)[propId] = std::move(configDeclaration);
+        }
+    }
+    closedir(dir);
+    return true;
 }
 
 Result<float> FakeVehicleHardware::safelyParseFloat(int index, const std::string& s) {
diff --git a/automotive/vehicle/aidl/impl/fake_impl/obd2frame/Android.bp b/automotive/vehicle/aidl/impl/fake_impl/obd2frame/Android.bp
index c1cee84..8fc7341 100644
--- a/automotive/vehicle/aidl/impl/fake_impl/obd2frame/Android.bp
+++ b/automotive/vehicle/aidl/impl/fake_impl/obd2frame/Android.bp
@@ -29,4 +29,5 @@
         "VehicleHalUtils",
     ],
     export_static_lib_headers: ["VehicleHalUtils"],
+    host_supported: true,
 }
diff --git a/automotive/vehicle/aidl/impl/fake_impl/userhal/Android.bp b/automotive/vehicle/aidl/impl/fake_impl/userhal/Android.bp
index 2e95531..181fd10 100644
--- a/automotive/vehicle/aidl/impl/fake_impl/userhal/Android.bp
+++ b/automotive/vehicle/aidl/impl/fake_impl/userhal/Android.bp
@@ -29,4 +29,5 @@
         "VehicleHalUtils",
     ],
     export_static_lib_headers: ["VehicleHalUtils"],
+    host_supported: true,
 }
diff --git a/automotive/vehicle/aidl/impl/grpc/Android.bp b/automotive/vehicle/aidl/impl/grpc/Android.bp
index e5106f8..fd1d1ca 100644
--- a/automotive/vehicle/aidl/impl/grpc/Android.bp
+++ b/automotive/vehicle/aidl/impl/grpc/Android.bp
@@ -127,4 +127,5 @@
     cflags: [
         "-Wno-unused-parameter",
     ],
+    host_supported: true,
 }
diff --git a/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/Android.bp b/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/Android.bp
index 52ef7be..d10aa3e 100644
--- a/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/Android.bp
+++ b/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/Android.bp
@@ -39,6 +39,7 @@
     ],
     defaults: ["VehicleHalDefaults"],
     export_static_lib_headers: ["VehicleHalUtils"],
+    host_supported: true,
 }
 
 cc_test {
diff --git a/automotive/vehicle/aidl/impl/hardware/Android.bp b/automotive/vehicle/aidl/impl/hardware/Android.bp
index edb0f29..52fd5e4 100644
--- a/automotive/vehicle/aidl/impl/hardware/Android.bp
+++ b/automotive/vehicle/aidl/impl/hardware/Android.bp
@@ -30,4 +30,5 @@
     export_header_lib_headers: [
         "VehicleHalUtilHeaders",
     ],
+    host_supported: true,
 }
diff --git a/automotive/vehicle/aidl/impl/utils/common/Android.bp b/automotive/vehicle/aidl/impl/utils/common/Android.bp
index e5d9346..5cd07b4 100644
--- a/automotive/vehicle/aidl/impl/utils/common/Android.bp
+++ b/automotive/vehicle/aidl/impl/utils/common/Android.bp
@@ -25,10 +25,12 @@
     local_include_dirs: ["include"],
     export_include_dirs: ["include"],
     defaults: ["VehicleHalDefaults"],
+    host_supported: true,
 }
 
 cc_library_headers {
     name: "VehicleHalUtilHeaders",
     export_include_dirs: ["include"],
     vendor: true,
+    host_supported: true,
 }
diff --git a/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp b/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp
index 97efdf6..a7caeb1 100644
--- a/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp
+++ b/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp
@@ -172,9 +172,7 @@
     }
 
     if (onValuesChangeCallback == nullptr && onValueChangeCallback == nullptr) {
-        ALOGW("No callback registered, ignoring property update for propId: %" PRId32
-              ", area ID: %" PRId32,
-              propId, areaId);
+        // No callback registered.
         return {};
     }