diff --git a/microdroid/Android.bp b/microdroid/Android.bp
index adb9ac8..4ddc03c 100644
--- a/microdroid/Android.bp
+++ b/microdroid/Android.bp
@@ -35,7 +35,7 @@
 android_filesystem {
     name: "microdroid",
     use_avb: true,
-    avb_private_key: "microdroid.pem",
+    avb_private_key: ":avb_testkey_rsa4096",
     avb_algorithm: "SHA256_RSA4096",
     partition_name: "system",
     deps: [
@@ -103,7 +103,7 @@
             ],
         },
     },
-    avb_private_key: "microdroid.pem",
+    avb_private_key: ":avb_testkey_rsa4096",
     avb_algorithm: "SHA256_RSA4096",
     file_contexts: "microdroid_vendor_file_contexts",
 }
@@ -159,7 +159,7 @@
     header_version: "4",
     partition_name: "boot",
     use_avb: true,
-    avb_private_key: "microdroid.pem",
+    avb_private_key: ":avb_testkey_rsa4096",
 }
 
 android_filesystem {
@@ -188,7 +188,7 @@
     vendor_boot: true,
     partition_name: "vendor_boot",
     use_avb: true,
-    avb_private_key: "microdroid.pem",
+    avb_private_key: ":avb_testkey_rsa4096",
 }
 
 android_filesystem {
@@ -272,7 +272,7 @@
 vbmeta {
     name: "microdroid_vbmeta",
     partition_name: "vbmeta",
-    private_key: "microdroid.pem",
+    private_key: ":avb_testkey_rsa4096",
     partitions: [
         "microdroid_vendor",
         "microdroid_vendor_boot-5.10",
@@ -281,12 +281,12 @@
         {
             name: "vbmeta_system",
             rollback_index_location: 1,
-            private_key: "microdroid.pem",
+            private_key: ":avb_testkey_rsa4096",
         },
         {
             name: "boot",
             rollback_index_location: 2,
-            private_key: "microdroid.pem",
+            private_key: ":avb_testkey_rsa4096",
         },
     ],
 }
@@ -294,7 +294,7 @@
 vbmeta {
     name: "microdroid_vbmeta_system",
     partition_name: "vbmeta_system",
-    private_key: "microdroid.pem",
+    private_key: ":avb_testkey_rsa4096",
     partitions: [
         "microdroid",
     ],
diff --git a/microdroid/microdroid.pem b/microdroid/microdroid.pem
deleted file mode 100644
index 2c9de45..0000000
--- a/microdroid/microdroid.pem
+++ /dev/null
@@ -1,51 +0,0 @@
------BEGIN RSA PRIVATE KEY-----
-MIIJKAIBAAKCAgEAwOn8PTeXaSbNtTx0iJspX7ZJn1dUWHeDtq/r6HPTCEnFuYqV
-c4foSjbF3nIR5T5ZxLeAcTYUl2A/mieUYKG7DkySf5LGlAgWOn4/UXSl14fvESBK
-XA51w9Stg3GyWycYYVkz52mDWfkfoic2UVQJXpsTTcAFDR+u8e5oDxscgLbU7/g2
-mbOv7E4B5n6ItscmjxzRh1IvFVRlPzzyDYQ8UF3JDk0Ndoz7Pze5hF72zbkH6Dmh
-zS91xZFuIJNPjEEjr4Nli9xADhEdsRPeJoFQa+XafGabR2Z2jbVk1UqkD0yxvDhw
-jQaSQ2P6W/flzJnQgRr21FHONU9B6sh+p2ulK3Huda7JIdCExA2SsP+2PVE1Kw9G
-s+85o1/8rfa576qwSLR++ztvZwg3DF/4UQME2oqGLM9TLyj8bdN3Co4XSwsJ7pru
-1WgyQ6S8qLrGld4oxxTbQYoVIhEjUjiOHSKggflZ76Mscnh5hv6ZnuhpbV0b0zSB
-95hP/fbc7VP3ru6ArHA3HF84MQ6i60YPrB5ZpB39wbex1AynbGG0bHw9kgo7L4bF
-rE6p7T6cVazWd0LcWE+WgBHXU2dcVtMPmxUTyzhoeTSVv6eDqagTCe0q3IBZ9h4c
-5q7O6Ipbu/3ckEeRlzBFp7ymjGosqZL0siYtNSKo+FJxvEtbcEiz8xKU6ksCAwEA
-AQKCAgABk+hUN9gtK/wSt2PcmihEeCEyBGzULGYPYHD1fb0EHFZZpiCCyWHE+Z20
-rAopbdEeIsISKvcQJeFfSWOVRr1Y6JdqI7EsFMTZxZ6O8/1HPf1ejn0NM7ES4PJq
-WMu0oyU35preEabZXYg8s0VmdOF+vJXz1NY1vUSZBfIj7XzWMKidLdKEf0u5CwpI
-8E/97rMKCJpOGQX5jq8lTUJNif9USPAUBd1OUujbI4GI653pINJHu/Du1KyJ6R6V
-dZ747q90CAcUlcCQXON5R0hR2EzoFQEsc0ph0xy1G/6vH+UnmuD5QRzqils34eFy
-Txy6B6gE5kuOgPzGwtcvLGScyeyX4rjA1RS+Zst8PQG35D2WSLENbITDZ2u2n146
-C/TWWd6F/qE8cSCI8/ZQ5iEarw8Hp3sVe7KRqwG0n2ESlW/px6E9DmzbjgW/BLwB
-diBLmHVmOT5BZPqbjNiwsX/aLmf7cjtnttFuadf2roaa6jlyQzsqRyVzJKH2H9iD
-DFeakMAjngVW0XnWrpgehoG5JfWDbXWcg8Kt5ZlegSOs1KGBAj69RkotJWjQ2rlP
-TijMuHgXVUIvqQp5BIc8UnVqX3kzljLd2eVM0K6ZcPnh+yBhk/Jd88whxkONgbs4
-g8EQvov4c8UL1Sx2ZTDDCN0WK0dHG1IhtB/E014yFIq/qqQMQQKCAQEA8c6tw7o+
-36Uh1uB5oEw6zSsxY7x13cW9tis9slD4/bXiXJwTOjs1/+S+wrmJ4UoOarygFgh0
-xWc1YGs20UWBkO4T9jaZJBqESH96RvQn7ubBEHYECClPhRuwbWWc+UzHjgusmuYl
-xPtY9MgtI5AF6O2MEqzCWbLZzFhhe/V6FKKcyV3aq6vOEjCeTz0/ntfcfS08T/5l
-kayny1nlVju3eig5WK30+X66rN0+eYS1PqLInlzSpFGWMJA6s+uI+1ze506QWKFI
-vNPf4Wtm8VFksRSbrYBriKg63UsgOGfaq5zmgJ5Yst8tIheKLJE5meLjGcea8Dhe
-gz+Jtj+Es9WdVQKCAQEAzDymkIOrwh8j45zFuH+6vataWkGusloV3P6dE0V5NDPH
-Oa/EfOqZ3qQKiS8bHRcdEwRQK+TSeOWi6phDQVu2lzwBA1PySxz7T1T38RKP9myu
-yPFah6bLKntvE36fj3U7RaU2gf8GXGMuwoRWoGDQNHQ+YusKOFreht7dlclqLKKp
-Xct7lKrg3nOtJI3P/jxXZwE/+UenqS5M8QOd7X0/77d9VJBYAhUZ9A5cOuk327e+
-zxEeg23UndcqmJRj0zsxYR+d/NaDV9yf8usAHRv/S3nwVN6YkmmnVNY46ukCNlxV
-G9VZcM1PNWFu3MdGs7f8u973DXYMC3Et3JD8/XNpHwKCAQEAoN8g6dOx2raRAdUL
-9eJhSHhQ/oq2W9ofsd+ox0ZpsNleBMDtZdNYxKsZYpFvssvDNa3ST3ZGwcI9V61c
-pfO5FIPgEfEXB1cA5P6yihwLqTwp+9qYKhnZxrO6N73fplg3d0A7ED7Hp/qUnx3C
-MiOyWtoXU6FOF8EOd43hJUgWdT4OU0W2onnFuoJQAGW+Ot5f2YPL2WhliHo2k+p1
-0l4eXg3+wQnSrl5qsXDsDIqGzmocUIduuFVzN1HtTCAKXTjXL0osbFq4+q93BhCf
-RzMga1NLky2Z3SwXJXzCreQiLgRPsggm+LHT5BeHHMltafzxnAgZA3JtJqKR6wbt
-MXuPlQKCAQBRaWvL93Cj9N3NgVSfcurxaDif+ca1eYt1iFj8sZja4jjsGdBtKucj
-BKjeflSEiA4i4nlCxffQEVmbwg4tI23pYxXUScYvguH6gZhEFG4mgLQ7jVnU8PvT
-d1iToMnh2Y1C+dR8hTf34+Fj0HTngS/9eMjVjXOJe09w263gY2VbXYu9w7sDTApP
-IjVGePEMGumMOcdSiumeWsJ44EQ3wtGVsMLYzqEGU3sA+ihxoz2M6/W3fM94/HLg
-aECmiaAxN0s7t+q2Opwojd2Ea4CkGeDuKTFP41tWIZ9+BdaybSdgm/WhHq6EdJK6
-aJhUkWrxgMnR6dL5HrE2bmslnPX74eFpAoIBAE4epxTb9SstOxhwFA1Vvrz5G64k
-n61OgXj49QPpBcBOGXVH1l8L6YQJO+bCVESiACn2Q/lJ8mp6lRI2KtsemUfsa5X7
-XV1qldtTFobMmB4JZDTEM882TWainK2+yhGfEGWrdeCWDBSWqQj/VLpAUqQqdJFU
-+GRvPQV+DSk4Az7zGpyrtjpiZYbRjWHBT2FAwSRS/iqEHjKrvrCqlaq16Un0JJFb
-0ztbCC2tDaVlwpojPnPE2sgojYeGQ0ghB1os9K4RFaoW9l+Pfye5vJ9G0/wmjVhY
-HQaN/WJp8k79mXacCQAD51xtWnJePGd4D5WbA855jo0Dov/mOtwf0Ahbl6w=
------END RSA PRIVATE KEY-----
diff --git a/tests/vsock_test.cc b/tests/vsock_test.cc
index 57a03ca..0df1c5d 100644
--- a/tests/vsock_test.cc
+++ b/tests/vsock_test.cc
@@ -27,10 +27,10 @@
 #include "android-base/logging.h"
 #include "android-base/parseint.h"
 #include "android-base/unique_fd.h"
-
 #include "virt/VirtualizationTest.h"
 
 using namespace android::base;
+using namespace android::os;
 
 namespace virt {
 
@@ -58,7 +58,9 @@
     ASSERT_EQ(ret, 0) << strerror(errno);
 
     sp<IVirtualMachine> vm;
-    status = mVirtManager->startVm(String16(kVmConfigPath), std::nullopt, &vm);
+    unique_fd vm_config_fd(open(kVmConfigPath, O_RDONLY | O_CLOEXEC));
+    status =
+            mVirtManager->startVm(ParcelFileDescriptor(std::move(vm_config_fd)), std::nullopt, &vm);
     ASSERT_TRUE(status.isOk()) << "Error starting VM: " << status;
 
     int32_t cid;
diff --git a/virtmanager/aidl/android/system/virtmanager/IVirtManager.aidl b/virtmanager/aidl/android/system/virtmanager/IVirtManager.aidl
index ab03c18..c2fc719 100644
--- a/virtmanager/aidl/android/system/virtmanager/IVirtManager.aidl
+++ b/virtmanager/aidl/android/system/virtmanager/IVirtManager.aidl
@@ -23,7 +23,8 @@
      * Start the VM with the given config file, and return a handle to it. If `logFd` is provided
      * then console logs from the VM will be sent to it.
      */
-    IVirtualMachine startVm(String configPath, in @nullable ParcelFileDescriptor logFd);
+    IVirtualMachine startVm(
+            in ParcelFileDescriptor configFd, in @nullable ParcelFileDescriptor logFd);
 
     /**
      * Get a list of all currently running VMs. This method is only intended for debug purposes,
diff --git a/virtmanager/aidl/android/system/virtmanager/VirtualMachineDebugInfo.aidl b/virtmanager/aidl/android/system/virtmanager/VirtualMachineDebugInfo.aidl
index d877a56..9003bc3 100644
--- a/virtmanager/aidl/android/system/virtmanager/VirtualMachineDebugInfo.aidl
+++ b/virtmanager/aidl/android/system/virtmanager/VirtualMachineDebugInfo.aidl
@@ -19,10 +19,4 @@
 parcelable VirtualMachineDebugInfo {
     /** The CID assigned to the VM. */
     int cid;
-
-    /**
-     * The filename of the config file used to start the VM. This may have changed since it was
-     * read so it shouldn't be trusted; it is only stored for debugging purposes.
-     */
-    String configPath;
 }
diff --git a/virtmanager/src/aidl.rs b/virtmanager/src/aidl.rs
index 8c963d2..ff8ab30 100644
--- a/virtmanager/src/aidl.rs
+++ b/virtmanager/src/aidl.rs
@@ -50,7 +50,7 @@
     /// Returns a binder `IVirtualMachine` object referring to it, as a handle for the client.
     fn startVm(
         &self,
-        config_path: &str,
+        config_fd: &ParcelFileDescriptor,
         log_fd: Option<&ParcelFileDescriptor>,
     ) -> binder::Result<Strong<dyn IVirtualMachine>> {
         let state = &mut *self.state.lock().unwrap();
@@ -58,7 +58,7 @@
         let log_fd = log_fd
             .map(|fd| fd.as_ref().try_clone().map_err(|_| StatusCode::UNKNOWN_ERROR))
             .transpose()?;
-        let instance = Arc::new(start_vm(config_path, cid, log_fd)?);
+        let instance = Arc::new(start_vm(config_fd.as_ref(), cid, log_fd)?);
         // TODO(qwandor): keep track of which CIDs are currently in use so that we can reuse them.
         state.next_cid = state.next_cid.checked_add(1).ok_or(StatusCode::UNKNOWN_ERROR)?;
         state.add_vm(Arc::downgrade(&instance));
@@ -74,13 +74,8 @@
 
         let state = &mut *self.state.lock().unwrap();
         let vms = state.vms();
-        let cids = vms
-            .into_iter()
-            .map(|vm| VirtualMachineDebugInfo {
-                cid: vm.cid as i32,
-                configPath: vm.config_path.clone(),
-            })
-            .collect();
+        let cids =
+            vms.into_iter().map(|vm| VirtualMachineDebugInfo { cid: vm.cid as i32 }).collect();
         Ok(cids)
     }
 
@@ -193,13 +188,13 @@
 
 /// Start a new VM instance from the given VM config filename. This assumes the VM is not already
 /// running.
-fn start_vm(config_path: &str, cid: Cid, log_fd: Option<File>) -> binder::Result<VmInstance> {
-    let config = VmConfig::load(config_path).map_err(|e| {
-        error!("Failed to load VM config {}: {:?}", config_path, e);
+fn start_vm(config_file: &File, cid: Cid, log_fd: Option<File>) -> binder::Result<VmInstance> {
+    let config = VmConfig::load(config_file).map_err(|e| {
+        error!("Failed to load VM config from {:?}: {:?}", config_file, e);
         StatusCode::BAD_VALUE
     })?;
-    Ok(VmInstance::start(&config, cid, config_path, log_fd).map_err(|e| {
-        error!("Failed to start VM {}: {:?}", config_path, e);
+    Ok(VmInstance::start(&config, cid, log_fd).map_err(|e| {
+        error!("Failed to start VM from {:?}: {:?}", config_file, e);
         StatusCode::UNKNOWN_ERROR
     })?)
 }
diff --git a/virtmanager/src/config.rs b/virtmanager/src/config.rs
index d8cb06f..0b12c0b 100644
--- a/virtmanager/src/config.rs
+++ b/virtmanager/src/config.rs
@@ -14,7 +14,7 @@
 
 //! Function and types for VM configuration.
 
-use anyhow::{bail, Context, Error};
+use anyhow::{bail, Error};
 use serde::{Deserialize, Serialize};
 use std::fs::File;
 use std::io::BufReader;
@@ -51,8 +51,7 @@
     }
 
     /// Load the configuration for a VM from the given JSON file.
-    pub fn load(path: &str) -> Result<VmConfig, Error> {
-        let file = File::open(path).with_context(|| format!("Failed to open {}", path))?;
+    pub fn load(file: &File) -> Result<VmConfig, Error> {
         let buffered = BufReader::new(file);
         Ok(serde_json::from_reader(buffered)?)
     }
diff --git a/virtmanager/src/crosvm.rs b/virtmanager/src/crosvm.rs
index 814a1a7..c865357 100644
--- a/virtmanager/src/crosvm.rs
+++ b/virtmanager/src/crosvm.rs
@@ -30,27 +30,19 @@
     child: Child,
     /// The CID assigned to the VM for vsock communication.
     pub cid: Cid,
-    /// The filename of the config file that was used to start the VM. This may have changed since
-    /// it was read so it shouldn't be trusted; it is only stored for debugging purposes.
-    pub config_path: String,
 }
 
 impl VmInstance {
     /// Create a new `VmInstance` for the given process.
-    fn new(child: Child, cid: Cid, config_path: &str) -> VmInstance {
-        VmInstance { child, cid, config_path: config_path.to_owned() }
+    fn new(child: Child, cid: Cid) -> VmInstance {
+        VmInstance { child, cid }
     }
 
     /// Start an instance of `crosvm` to manage a new VM. The `crosvm` instance will be killed when
     /// the `VmInstance` is dropped.
-    pub fn start(
-        config: &VmConfig,
-        cid: Cid,
-        config_path: &str,
-        log_fd: Option<File>,
-    ) -> Result<VmInstance, Error> {
+    pub fn start(config: &VmConfig, cid: Cid, log_fd: Option<File>) -> Result<VmInstance, Error> {
         let child = run_vm(config, cid, log_fd)?;
-        Ok(VmInstance::new(child, cid, config_path))
+        Ok(VmInstance::new(child, cid))
     }
 }
 
diff --git a/vm/src/main.rs b/vm/src/main.rs
index 8c2a084..1f39e4a 100644
--- a/vm/src/main.rs
+++ b/vm/src/main.rs
@@ -77,9 +77,12 @@
     daemonize: bool,
 ) -> Result<(), Error> {
     let config_filename = config_path.to_str().context("Failed to parse VM config path")?;
+    let config_file = ParcelFileDescriptor::new(
+        File::open(config_filename).context("Failed to open config file")?,
+    );
     let stdout_file = ParcelFileDescriptor::new(duplicate_stdout()?);
     let stdout = if daemonize { None } else { Some(&stdout_file) };
-    let vm = virt_manager.startVm(config_filename, stdout).context("Failed to start VM")?;
+    let vm = virt_manager.startVm(&config_file, stdout).context("Failed to start VM")?;
 
     let cid = vm.getCid().context("Failed to get CID")?;
     println!("Started VM from {} with CID {}.", config_filename, cid);