diff --git a/tests/benchmark/Android.bp b/tests/benchmark/Android.bp
index f1aebd2..acd0f09 100644
--- a/tests/benchmark/Android.bp
+++ b/tests/benchmark/Android.bp
@@ -19,6 +19,7 @@
     libs: ["android.system.virtualmachine"],
     jni_libs: [
         "MicrodroidBenchmarkNativeLib",
+        "MicrodroidIdleNativeLib",
         "libiovsock_host_jni",
     ],
     platform_apis: true,
@@ -27,6 +28,14 @@
 }
 
 cc_library_shared {
+    name: "MicrodroidIdleNativeLib",
+    srcs: ["src/native/idlebinary.cpp"],
+    shared_libs: [
+        "libbase",
+    ],
+}
+
+cc_library_shared {
     name: "MicrodroidBenchmarkNativeLib",
     srcs: ["src/native/benchmarkbinary.cpp"],
     static_libs: ["libiobenchmark"],
diff --git a/tests/benchmark/assets/vm_config.json b/tests/benchmark/assets/vm_config.json
index e8f43e0..5a604a9 100644
--- a/tests/benchmark/assets/vm_config.json
+++ b/tests/benchmark/assets/vm_config.json
@@ -4,10 +4,7 @@
   },
   "task": {
     "type": "microdroid_launcher",
-    "command": "MicrodroidBenchmarkNativeLib.so",
-    "args": [
-      "no_io"
-    ]
+    "command": "MicrodroidIdleNativeLib.so"
   },
   "export_tombstones": true
 }
diff --git a/tests/benchmark/assets/vm_config_io.json b/tests/benchmark/assets/vm_config_io.json
index 1a5a9e5..66046ba 100644
--- a/tests/benchmark/assets/vm_config_io.json
+++ b/tests/benchmark/assets/vm_config_io.json
@@ -4,10 +4,7 @@
   },
   "task": {
     "type": "microdroid_launcher",
-    "command": "MicrodroidBenchmarkNativeLib.so",
-    "args": [
-      "io"
-    ]
+    "command": "MicrodroidBenchmarkNativeLib.so"
   },
   "apexes": [
     {
diff --git a/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java b/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
index e0e2274..b1a1160 100644
--- a/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
+++ b/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
@@ -406,7 +406,11 @@
             new Thread(() -> sendRate.set(runVsockClientAndSendData(vm))).start();
             benchmarkService.runVsockServerAndReceiveData(serverFd, NUM_BYTES_TO_TRANSFER);
 
-            mReadRates.add(sendRate.get());
+            Double rate = sendRate.get();
+            if (rate == null) {
+                throw new IllegalStateException("runVsockClientAndSendData() failed");
+            }
+            mReadRates.add(rate);
         }
 
         private double runVsockClientAndSendData(VirtualMachine vm) {
diff --git a/tests/benchmark/src/native/benchmarkbinary.cpp b/tests/benchmark/src/native/benchmarkbinary.cpp
index 58b4cf0..8694ef9 100644
--- a/tests/benchmark/src/native/benchmarkbinary.cpp
+++ b/tests/benchmark/src/native/benchmarkbinary.cpp
@@ -182,17 +182,10 @@
 }
 } // Anonymous namespace
 
-extern "C" int android_native_main([[maybe_unused]] int argc, char* argv[]) {
-    if (strcmp(argv[1], "no_io") == 0) {
-        // do nothing for now; just leave it alive. good night.
-        for (;;) {
-            sleep(1000);
-        }
-    } else if (strcmp(argv[1], "io") == 0) {
-        if (auto res = run_io_benchmark_tests(); !res.ok()) {
-            LOG(ERROR) << "IO benchmark test failed: " << res.error() << "\n";
-            return EXIT_FAILURE;
-        }
+extern "C" int android_native_main(int /* argc */, char* /* argv */[]) {
+    if (auto res = run_io_benchmark_tests(); !res.ok()) {
+        LOG(ERROR) << "IO benchmark test failed: " << res.error() << "\n";
+        return EXIT_FAILURE;
     }
     return EXIT_SUCCESS;
 }
diff --git a/tests/benchmark/src/native/idlebinary.cpp b/tests/benchmark/src/native/idlebinary.cpp
new file mode 100644
index 0000000..a74e7bf
--- /dev/null
+++ b/tests/benchmark/src/native/idlebinary.cpp
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+#include <unistd.h>
+
+extern "C" int android_native_main(int /* argc */, char* /* argv */[]) {
+    // do nothing; just leave it alive. good night.
+    for (;;) {
+        sleep(1000);
+    }
+}
diff --git a/tests/testapk/Android.bp b/tests/testapk/Android.bp
index 47116eb..4dff0a2 100644
--- a/tests/testapk/Android.bp
+++ b/tests/testapk/Android.bp
@@ -20,7 +20,10 @@
         "compatibility-common-util-devicesidelib",
     ],
     libs: ["android.system.virtualmachine"],
-    jni_libs: ["MicrodroidTestNativeLib"],
+    jni_libs: [
+        "MicrodroidTestNativeLib",
+        "MicrodroidTestNativeCrashLib",
+    ],
     platform_apis: true,
     use_embedded_native_libs: true,
     // We only support 64-bit ABI, but CTS demands all APKs to be multi-ABI.
@@ -48,6 +51,11 @@
 }
 
 cc_library_shared {
+    name: "MicrodroidTestNativeCrashLib",
+    srcs: ["src/native/crashbinary.cpp"],
+}
+
+cc_library_shared {
     name: "MicrodroidTestNativeLibSub",
     srcs: ["src/native/testlib.cpp"],
 }
diff --git a/tests/testapk/assets/vm_config.json b/tests/testapk/assets/vm_config.json
index da420ff..d12eb5c 100644
--- a/tests/testapk/assets/vm_config.json
+++ b/tests/testapk/assets/vm_config.json
@@ -4,11 +4,7 @@
   },
   "task": {
     "type": "microdroid_launcher",
-    "command": "MicrodroidTestNativeLib.so",
-    "args": [
-      "hello",
-      "microdroid"
-    ]
+    "command": "MicrodroidTestNativeLib.so"
   },
   "export_tombstones": true
 }
diff --git a/tests/testapk/assets/vm_config_apex.json b/tests/testapk/assets/vm_config_apex.json
index 0f100aa..c00787f 100644
--- a/tests/testapk/assets/vm_config_apex.json
+++ b/tests/testapk/assets/vm_config_apex.json
@@ -4,11 +4,7 @@
   },
   "task": {
     "type": "microdroid_launcher",
-    "command": "MicrodroidTestNativeLib.so",
-    "args": [
-      "hello",
-      "microdroid"
-    ]
+    "command": "MicrodroidTestNativeLib.so"
   },
   "apexes": [
     {
diff --git a/tests/testapk/assets/vm_config_crash.json b/tests/testapk/assets/vm_config_crash.json
index 282f25c..2951fdf 100644
--- a/tests/testapk/assets/vm_config_crash.json
+++ b/tests/testapk/assets/vm_config_crash.json
@@ -4,10 +4,7 @@
     },
     "task": {
       "type": "microdroid_launcher",
-      "command": "MicrodroidTestNativeLib.so",
-      "args": [
-        "crash"
-      ]
+      "command": "MicrodroidTestNativeCrashLib.so"
     },
     "export_tombstones": true
   }
diff --git a/tests/testapk/assets/vm_config_crash_no_tombstone.json b/tests/testapk/assets/vm_config_crash_no_tombstone.json
index be0983d..583f87b 100644
--- a/tests/testapk/assets/vm_config_crash_no_tombstone.json
+++ b/tests/testapk/assets/vm_config_crash_no_tombstone.json
@@ -4,10 +4,7 @@
     },
     "task": {
       "type": "microdroid_launcher",
-      "command": "MicrodroidTestNativeLib.so",
-      "args": [
-        "crash"
-      ]
+      "command": "MicrodroidTestNativeCrashLib.so"
     },
     "export_tombstones": false
   }
diff --git a/tests/testapk/assets/vm_config_extra_apk.json b/tests/testapk/assets/vm_config_extra_apk.json
index d7d3dd7..b45e57d 100644
--- a/tests/testapk/assets/vm_config_extra_apk.json
+++ b/tests/testapk/assets/vm_config_extra_apk.json
@@ -4,11 +4,7 @@
   },
   "task": {
     "type": "microdroid_launcher",
-    "command": "MicrodroidTestNativeLib.so",
-    "args": [
-      "hello",
-      "microdroid"
-    ]
+    "command": "MicrodroidTestNativeLib.so"
   },
   "extra_apks": [
     {
diff --git a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
index b0ec359..3681348 100644
--- a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
+++ b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
@@ -122,7 +122,8 @@
     @Test
     public void bootFailsWhenLowMem() throws Exception {
         for (int memMib : new int[]{ 10, 20, 40 }) {
-            VirtualMachineConfig lowMemConfig = mInner.newVmConfigBuilder("assets/vm_config.json")
+            VirtualMachineConfig lowMemConfig = mInner.newVmConfigBuilder()
+                    .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
                     .setMemoryMib(memMib)
                     .setDebugLevel(DEBUG_LEVEL_NONE)
                     .build();
@@ -157,8 +158,10 @@
     public void changingDebugLevelInvalidatesVmIdentity() throws Exception {
         assumeSupportedKernel();
 
-        VirtualMachineConfig.Builder builder = mInner.newVmConfigBuilder("assets/vm_config.json");
-        VirtualMachineConfig normalConfig = builder.setDebugLevel(DEBUG_LEVEL_NONE).build();
+        VirtualMachineConfig.Builder builder = mInner.newVmConfigBuilder()
+                .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                .setDebugLevel(DEBUG_LEVEL_NONE);
+        VirtualMachineConfig normalConfig = builder.build();
         mInner.forceCreateNewVirtualMachine("test_vm", normalConfig);
         assertThat(tryBootVm(TAG, "test_vm").payloadStarted).isTrue();
 
@@ -219,7 +222,8 @@
     public void instancesOfSameVmHaveDifferentCdis() throws Exception {
         assumeSupportedKernel();
 
-        VirtualMachineConfig normalConfig = mInner.newVmConfigBuilder("assets/vm_config.json")
+        VirtualMachineConfig normalConfig = mInner.newVmConfigBuilder()
+                .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
                 .setDebugLevel(DEBUG_LEVEL_FULL)
                 .build();
         mInner.forceCreateNewVirtualMachine("test_vm_a", normalConfig);
@@ -243,7 +247,8 @@
     public void sameInstanceKeepsSameCdis() throws Exception {
         assumeSupportedKernel();
 
-        VirtualMachineConfig normalConfig = mInner.newVmConfigBuilder("assets/vm_config.json")
+        VirtualMachineConfig normalConfig = mInner.newVmConfigBuilder()
+                .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
                 .setDebugLevel(DEBUG_LEVEL_FULL)
                 .build();
         mInner.forceCreateNewVirtualMachine("test_vm", normalConfig);
@@ -264,7 +269,8 @@
     public void bccIsSuperficiallyWellFormed() throws Exception {
         assumeSupportedKernel();
 
-        VirtualMachineConfig normalConfig = mInner.newVmConfigBuilder("assets/vm_config.json")
+        VirtualMachineConfig normalConfig = mInner.newVmConfigBuilder()
+                .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
                 .setDebugLevel(DEBUG_LEVEL_FULL)
                 .build();
         VirtualMachine vm = mInner.forceCreateNewVirtualMachine("bcc_vm", normalConfig);
@@ -338,7 +344,8 @@
     }
 
     private RandomAccessFile prepareInstanceImage(String vmName) throws Exception {
-        VirtualMachineConfig config = mInner.newVmConfigBuilder("assets/vm_config.json")
+        VirtualMachineConfig config = mInner.newVmConfigBuilder()
+                .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
                 .setDebugLevel(DEBUG_LEVEL_FULL)
                 .build();
 
@@ -411,14 +418,16 @@
 
     @Test
     public void sameInstancesShareTheSameVmObject() throws Exception {
-        VirtualMachineConfig.Builder builder =
-                mInner.newVmConfigBuilder("assets/vm_config.json");
-        VirtualMachineConfig normalConfig = builder.setDebugLevel(DEBUG_LEVEL_NONE).build();
-        VirtualMachine vm = mInner.forceCreateNewVirtualMachine("test_vm", normalConfig);
+        VirtualMachineConfig config = mInner.newVmConfigBuilder()
+                .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                .setDebugLevel(DEBUG_LEVEL_NONE)
+                .build();
+
+        VirtualMachine vm = mInner.forceCreateNewVirtualMachine("test_vm", config);
         VirtualMachine vm2 = mInner.getVirtualMachineManager().get("test_vm");
         assertThat(vm).isEqualTo(vm2);
 
-        VirtualMachine newVm = mInner.forceCreateNewVirtualMachine("test_vm", normalConfig);
+        VirtualMachine newVm = mInner.forceCreateNewVirtualMachine("test_vm", config);
         VirtualMachine newVm2 = mInner.getVirtualMachineManager().get("test_vm");
         assertThat(newVm).isEqualTo(newVm2);
 
diff --git a/tests/testapk/src/native/crashbinary.cpp b/tests/testapk/src/native/crashbinary.cpp
new file mode 100644
index 0000000..9f80fd0
--- /dev/null
+++ b/tests/testapk/src/native/crashbinary.cpp
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2022 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.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+// A VM payload that crashes as soon as it starts, to allow us to exercise that error path.
+extern "C" int android_native_main(int /* argc */, char* /* argv */[]) {
+    printf("test crash!!!!\n");
+    abort();
+}
diff --git a/tests/testapk/src/native/testbinary.cpp b/tests/testapk/src/native/testbinary.cpp
index c8d07a3..422afca 100644
--- a/tests/testapk/src/native/testbinary.cpp
+++ b/tests/testapk/src/native/testbinary.cpp
@@ -181,11 +181,6 @@
     setvbuf(stdout, nullptr, _IONBF, 0);
     setvbuf(stderr, nullptr, _IONBF, 0);
 
-    if (argc >= 2 && strcmp(argv[1], "crash") == 0) {
-        printf("test crash!!!!\n");
-        abort();
-    }
-
     printf("Hello Microdroid ");
     for (int i = 0; i < argc; i++) {
         printf("%s", argv[i]);