diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
index d3c6910..7150c44 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
@@ -45,5 +45,6 @@
   android.hardware.security.keymint.BeginResult begin(in android.hardware.security.keymint.KeyPurpose purpose, in byte[] keyBlob, in android.hardware.security.keymint.KeyParameter[] params, in android.hardware.security.keymint.HardwareAuthToken authToken);
   void deviceLocked(in boolean passwordOnly, in @nullable android.hardware.security.secureclock.TimeStampToken timestampToken);
   void earlyBootEnded();
+  byte[] performOperation(in byte[] request);
   const int AUTH_TOKEN_MAC_LENGTH = 32;
 }
diff --git a/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl b/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
index 6d42db2..384416e 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
@@ -760,4 +760,18 @@
      * an EARLY_BOOT_ONLY key after this method is called must fail with Error::INVALID_KEY_BLOB.
      */
     void earlyBootEnded();
+
+    /**
+     * Called by the client to perform a KeyMint operation.
+     *
+     *  This method is added primarily as a placeholder.  Details will be fleshed before the KeyMint
+     *  V1 interface is frozen.  Until then, implementations must return ErrorCode::UNIMPLEMENTED.
+     *
+     * @param request is an encrypted buffer containing a description of the operation the client
+     *        wishes to perform.  Structure, content and encryption are TBD.
+     *
+     * @return an encrypted buffer containing the result of the operation.  Structure, content and
+     *         encryption are TBD.
+     */
+    byte[] performOperation(in byte[] request);
 }
diff --git a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
index e79fe80..0aef81b 100644
--- a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
+++ b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
@@ -261,7 +261,7 @@
     ErrorCode UseRsaKey(const vector<uint8_t>& rsaKeyBlob);
     ErrorCode UseEcdsaKey(const vector<uint8_t>& ecdsaKeyBlob);
 
-  private:
+  protected:
     std::shared_ptr<IKeyMintDevice> keymint_;
     uint32_t os_version_;
     uint32_t os_patch_level_;
diff --git a/security/keymint/aidl/vts/functional/KeyMintTest.cpp b/security/keymint/aidl/vts/functional/KeyMintTest.cpp
index f8eca6b..7ecfa37 100644
--- a/security/keymint/aidl/vts/functional/KeyMintTest.cpp
+++ b/security/keymint/aidl/vts/functional/KeyMintTest.cpp
@@ -4633,7 +4633,7 @@
 
 INSTANTIATE_KEYMINT_AIDL_TEST(KeyAgreementTest);
 
-typedef KeyMintAidlTestBase EarlyBootKeyTest;
+using EarlyBootKeyTest = KeyMintAidlTestBase;
 
 TEST_P(EarlyBootKeyTest, CreateEarlyBootKeys) {
     auto [aesKeyData, hmacKeyData, rsaKeyData, ecdsaKeyData] =
@@ -4690,9 +4690,10 @@
     CheckedDeleteKey(&rsaKeyData.blob);
     CheckedDeleteKey(&ecdsaKeyData.blob);
 }
+
 INSTANTIATE_KEYMINT_AIDL_TEST(EarlyBootKeyTest);
 
-typedef KeyMintAidlTestBase UnlockedDeviceRequiredTest;
+using UnlockedDeviceRequiredTest = KeyMintAidlTestBase;
 
 // This may be a problematic test.  It can't be run repeatedly without unlocking the device in
 // between runs... and on most test devices there are no enrolled credentials so it can't be
@@ -4724,8 +4725,19 @@
     CheckedDeleteKey(&rsaKeyData.blob);
     CheckedDeleteKey(&ecdsaKeyData.blob);
 }
+
 INSTANTIATE_KEYMINT_AIDL_TEST(UnlockedDeviceRequiredTest);
 
+using PerformOperationTest = KeyMintAidlTestBase;
+
+TEST_P(PerformOperationTest, RequireUnimplemented) {
+    vector<uint8_t> response;
+    auto result = keymint_->performOperation({} /* request */, &response);
+    ASSERT_EQ(GetReturnErrorCode(result), ErrorCode::UNIMPLEMENTED);
+}
+
+INSTANTIATE_KEYMINT_AIDL_TEST(PerformOperationTest);
+
 }  // namespace aidl::android::hardware::security::keymint::test
 
 int main(int argc, char** argv) {