diff --git a/android/virtmgr/src/crosvm.rs b/android/virtmgr/src/crosvm.rs
index 37618c7..08a9e47 100644
--- a/android/virtmgr/src/crosvm.rs
+++ b/android/virtmgr/src/crosvm.rs
@@ -25,7 +25,6 @@
 use log::{debug, error, info};
 use semver::{Version, VersionReq};
 use nix::{fcntl::OFlag, unistd::pipe2, unistd::Uid, unistd::User};
-use nix::unistd::dup;
 use regex::{Captures, Regex};
 use rustutils::system_properties;
 use shared_child::SharedChild;
@@ -36,7 +35,6 @@
 use std::io::{self, Read};
 use std::mem;
 use std::num::{NonZeroU16, NonZeroU32};
-use std::os::fd::FromRawFd;
 use std::os::unix::io::{AsRawFd, OwnedFd};
 use std::os::unix::process::ExitStatusExt;
 use std::path::{Path, PathBuf};
@@ -59,7 +57,6 @@
 use rpcbinder::RpcServer;
 
 /// external/crosvm
-use base::AsRawDescriptor;
 use base::UnixSeqpacketListener;
 use vm_control::{BalloonControlCommand, VmRequest, VmResponse};
 
@@ -1042,14 +1039,7 @@
 
     let control_sock = UnixSeqpacketListener::bind(crosvm_control_socket_path)
         .context("failed to create control server")?;
-    command.arg("--socket").arg(add_preserved_fd(&mut preserved_fds, {
-        let dup_fd = dup(control_sock.as_raw_descriptor())?;
-        // SAFETY: UnixSeqpacketListener doesn't provide a way to convert it into a RawFd or
-        // OwnedFd. In order to provide a OwnedFd for add_preserved_fd, dup the control socket
-        // and create a OwnedFd from the duped fd. This is fine as the original fd is still
-        // closed when control_socket is dropped.
-        unsafe { OwnedFd::from_raw_fd(dup_fd) }
-    }));
+    command.arg("--socket").arg(add_preserved_fd(&mut preserved_fds, control_sock));
 
     if let Some(dt_overlay) = config.device_tree_overlay {
         command.arg("--device-tree-overlay").arg(add_preserved_fd(&mut preserved_fds, dt_overlay));
@@ -1103,9 +1093,9 @@
 
     if cfg!(network) {
         if let Some(tap) = config.tap {
-            command
-                .arg("--net")
-                .arg(format!("tap-fd={}", add_preserved_fd(&mut preserved_fds, tap)));
+            add_preserved_fd(&mut preserved_fds, tap);
+            let tap_fd = preserved_fds.last().unwrap().as_raw_fd();
+            command.arg("--net").arg(format!("tap-fd={tap_fd}"));
         }
     }
 
diff --git a/build/apex/Android.bp b/build/apex/Android.bp
index 0a2b2de..3a6ebb8 100644
--- a/build/apex/Android.bp
+++ b/build/apex/Android.bp
@@ -7,12 +7,28 @@
     "microdroid_vbmeta",
 ]
 
-apex {
+soong_config_module_type {
+    name: "virt_apex",
+    module_type: "apex",
+    config_namespace: "ANDROID",
+    bool_variables: [
+        "avf_enabled",
+    ],
+    properties: [
+        "defaults",
+    ],
+}
+
+virt_apex {
     name: "com.android.virt",
-    defaults: select(soong_config_variable("ANDROID", "avf_enabled"), {
-        "true": ["com.android.virt_avf_enabled"],
-        default: ["com.android.virt_avf_disabled"],
-    }),
+    soong_config_variables: {
+        avf_enabled: {
+            defaults: ["com.android.virt_avf_enabled"],
+            conditions_default: {
+                defaults: ["com.android.virt_avf_disabled"],
+            },
+        },
+    },
 }
 
 apex_defaults {
diff --git a/libs/framework-virtualization/Android.bp b/libs/framework-virtualization/Android.bp
index d3a2b54..d02eec6 100644
--- a/libs/framework-virtualization/Android.bp
+++ b/libs/framework-virtualization/Android.bp
@@ -9,7 +9,10 @@
 
     jarjar_rules: "jarjar-rules.txt",
 
-    srcs: ["src/**/*.java"],
+    srcs: [
+        "src/**/*.java",
+        ":avf-build-flags-java-gen",
+    ],
     static_libs: [
         "android.system.virtualizationservice-java",
         "avf_aconfig_flags_java",
@@ -53,3 +56,15 @@
         ],
     },
 }
+
+gensrcs {
+    name: "avf-build-flags-java-gen",
+    srcs: ["src/**/BuildFlags.java_template"],
+    output_extension: "java",
+    cmd: "cp $(in) $(genDir)/tmp.java && " +
+        select(release_flag("RELEASE_AVF_ENABLE_VENDOR_MODULES"), {
+            true: "sed -ie 's/@vendor_modules_enabled_placeholder/true/g'",
+            default: "sed -ie 's/@vendor_modules_enabled_placeholder/false/g'",
+        }) + " $(genDir)/tmp.java && " +
+        " cp $(genDir)/tmp.java $(out)",
+}
diff --git a/libs/framework-virtualization/src/android/system/virtualmachine/BuildFlags.java_template b/libs/framework-virtualization/src/android/system/virtualmachine/BuildFlags.java_template
new file mode 100644
index 0000000..12b249c
--- /dev/null
+++ b/libs/framework-virtualization/src/android/system/virtualmachine/BuildFlags.java_template
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2024 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.
+ */
+
+package android.system.virtualmachine;
+
+/**
+ * Exposes AVF build flags (RELEASE_AVF_*) to java.
+ *
+ * @hide
+ */
+public final class BuildFlags {
+
+    /**
+     * Value of the {@code RELEASE_AVF_ENABLE_VENDOR_MODULES} build flag.
+     */
+    public static boolean VENDOR_MODULES_ENABLED = @vendor_modules_enabled_placeholder;
+
+    private BuildFlags() {};
+}
+
diff --git a/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachineManager.java b/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachineManager.java
index 242dc91..9295c6c 100644
--- a/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachineManager.java
+++ b/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachineManager.java
@@ -371,10 +371,6 @@
     private static final List<String> SUPPORTED_OS_LIST_FROM_CFG =
             extractSupportedOSListFromConfig();
 
-    private boolean isVendorModuleEnabled() {
-        return VirtualizationService.nativeIsVendorModulesFlagEnabled();
-    }
-
     private static List<String> extractSupportedOSListFromConfig() {
         List<String> supportedOsList = new ArrayList<>();
         File directory = new File("/apex/com.android.virt/etc");
@@ -400,7 +396,7 @@
     @FlaggedApi(Flags.FLAG_AVF_V_TEST_APIS)
     @NonNull
     public List<String> getSupportedOSList() throws VirtualMachineException {
-        if (isVendorModuleEnabled()) {
+        if (BuildFlags.VENDOR_MODULES_ENABLED) {
             return SUPPORTED_OS_LIST_FROM_CFG;
         } else {
             return Arrays.asList("microdroid");
diff --git a/libs/framework-virtualization/src/android/system/virtualmachine/VirtualizationService.java b/libs/framework-virtualization/src/android/system/virtualmachine/VirtualizationService.java
index 83b64ee..57990a9 100644
--- a/libs/framework-virtualization/src/android/system/virtualmachine/VirtualizationService.java
+++ b/libs/framework-virtualization/src/android/system/virtualmachine/VirtualizationService.java
@@ -51,12 +51,6 @@
     private native boolean nativeIsOk(int clientFd);
 
     /*
-     * Retrieve boolean value whether RELEASE_AVF_ENABLE_VENDOR_MODULES build flag is enabled or
-     * not.
-     */
-    static native boolean nativeIsVendorModulesFlagEnabled();
-
-    /*
      * Spawns a new virtmgr subprocess that will host a VirtualizationService
      * AIDL service.
      */
diff --git a/libs/libsafe_ownedfd/Android.bp b/libs/libsafe_ownedfd/Android.bp
new file mode 100644
index 0000000..1f14578
--- /dev/null
+++ b/libs/libsafe_ownedfd/Android.bp
@@ -0,0 +1,37 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+rust_defaults {
+    name: "libsafe_ownedfd.defaults",
+    crate_name: "safe_ownedfd",
+    srcs: ["src/lib.rs"],
+    edition: "2021",
+    rustlibs: [
+        "libnix",
+        "libthiserror",
+    ],
+}
+
+rust_library {
+    name: "libsafe_ownedfd",
+    defaults: ["libsafe_ownedfd.defaults"],
+    apex_available: [
+        "com.android.compos",
+        "com.android.virt",
+    ],
+}
+
+rust_test {
+    name: "libsafe_ownedfd.test",
+    defaults: ["libsafe_ownedfd.defaults"],
+    rustlibs: [
+        "libanyhow",
+        "libtempfile",
+    ],
+    host_supported: true,
+    test_suites: ["general-tests"],
+    test_options: {
+        unit_test: true,
+    },
+}
diff --git a/libs/libsafe_ownedfd/src/lib.rs b/libs/libsafe_ownedfd/src/lib.rs
new file mode 100644
index 0000000..52ae180
--- /dev/null
+++ b/libs/libsafe_ownedfd/src/lib.rs
@@ -0,0 +1,127 @@
+// Copyright 2024, 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 for a safer conversion from `RawFd` to `OwnedFd`
+
+use nix::fcntl::{fcntl, FdFlag, F_DUPFD, F_GETFD, F_SETFD};
+use nix::libc;
+use nix::unistd::close;
+use std::os::fd::FromRawFd;
+use std::os::fd::OwnedFd;
+use std::os::fd::RawFd;
+use std::sync::Mutex;
+use thiserror::Error;
+
+/// Errors that can occur while taking an ownership of `RawFd`
+#[derive(Debug, PartialEq, Error)]
+pub enum Error {
+    /// RawFd is not a valid file descriptor
+    #[error("{0} is not a file descriptor")]
+    Invalid(RawFd),
+
+    /// RawFd is either stdio, stdout, or stderr
+    #[error("standard IO descriptors cannot be owned")]
+    StdioNotAllowed,
+
+    /// Generic UNIX error
+    #[error("UNIX error")]
+    Errno(#[from] nix::errno::Errno),
+}
+
+static LOCK: Mutex<()> = Mutex::new(());
+
+/// Takes the ownership of `RawFd` and converts it to `OwnedFd`. It is important to know that
+/// `RawFd` is closed when this function successfully returns. The raw file descriptor of the
+/// returned `OwnedFd` is different from `RawFd`. The returned file descriptor is CLOEXEC set.
+pub fn take_fd_ownership(raw_fd: RawFd) -> Result<OwnedFd, Error> {
+    fcntl(raw_fd, F_GETFD).map_err(|_| Error::Invalid(raw_fd))?;
+
+    if [libc::STDIN_FILENO, libc::STDOUT_FILENO, libc::STDERR_FILENO].contains(&raw_fd) {
+        return Err(Error::StdioNotAllowed);
+    }
+
+    // sync is needed otherwise we can create multiple OwnedFds out of the same RawFd
+    let lock = LOCK.lock().unwrap();
+    let new_fd = fcntl(raw_fd, F_DUPFD(raw_fd))?;
+    close(raw_fd)?;
+    drop(lock);
+
+    // This is not essential, but let's follow the common practice in the Rust ecosystem
+    fcntl(new_fd, F_SETFD(FdFlag::FD_CLOEXEC)).map_err(Error::Errno)?;
+
+    // SAFETY: In this function, we have checked that RawFd is actually an open file descriptor and
+    // this is the first time to claim its ownership because we just created it by duping.
+    Ok(unsafe { OwnedFd::from_raw_fd(new_fd) })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use anyhow::Result;
+    use nix::fcntl::{fcntl, FdFlag, F_GETFD, F_SETFD};
+    use std::os::fd::AsRawFd;
+    use std::os::fd::IntoRawFd;
+    use tempfile::tempfile;
+
+    #[test]
+    fn good_fd() -> Result<()> {
+        let raw_fd = tempfile()?.into_raw_fd();
+        assert!(take_fd_ownership(raw_fd).is_ok());
+        Ok(())
+    }
+
+    #[test]
+    fn invalid_fd() -> Result<()> {
+        let raw_fd = 12345; // randomly chosen
+        assert_eq!(take_fd_ownership(raw_fd).unwrap_err(), Error::Invalid(raw_fd));
+        Ok(())
+    }
+
+    #[test]
+    fn original_fd_closed() -> Result<()> {
+        let raw_fd = tempfile()?.into_raw_fd();
+        let owned_fd = take_fd_ownership(raw_fd)?;
+        assert_ne!(raw_fd, owned_fd.as_raw_fd());
+        assert!(fcntl(raw_fd, F_GETFD).is_err());
+        Ok(())
+    }
+
+    #[test]
+    fn cannot_use_same_rawfd_multiple_times() -> Result<()> {
+        let raw_fd = tempfile()?.into_raw_fd();
+
+        let owned_fd = take_fd_ownership(raw_fd); // once
+        let owned_fd2 = take_fd_ownership(raw_fd); // twice
+
+        assert!(owned_fd.is_ok());
+        assert!(owned_fd2.is_err());
+        Ok(())
+    }
+
+    #[test]
+    fn cloexec() -> Result<()> {
+        let raw_fd = tempfile()?.into_raw_fd();
+
+        // intentionally clear cloexec to see if it is set by take_fd_ownership
+        fcntl(raw_fd, F_SETFD(FdFlag::empty()))?;
+        let flags = fcntl(raw_fd, F_GETFD)?;
+        assert_eq!(flags, FdFlag::empty().bits());
+
+        let owned_fd = take_fd_ownership(raw_fd)?;
+        let flags = fcntl(owned_fd.as_raw_fd(), F_GETFD)?;
+        assert_eq!(flags, FdFlag::FD_CLOEXEC.bits());
+        drop(owned_fd);
+        Ok(())
+    }
+}
diff --git a/libs/libvirtualization_jni/android_system_virtualmachine_VirtualizationService.cpp b/libs/libvirtualization_jni/android_system_virtualmachine_VirtualizationService.cpp
index ced2079..0538c9e 100644
--- a/libs/libvirtualization_jni/android_system_virtualmachine_VirtualizationService.cpp
+++ b/libs/libvirtualization_jni/android_system_virtualmachine_VirtualizationService.cpp
@@ -108,9 +108,3 @@
     }
     return pfds[0].revents == 0;
 }
-
-extern "C" JNIEXPORT jboolean JNICALL
-Java_android_system_virtualmachine_VirtualizationService_nativeIsVendorModulesFlagEnabled(
-        [[maybe_unused]] JNIEnv* env, [[maybe_unused]] jobject obj) {
-    return android::virtualization::IsVendorModulesFlagEnabled();
-}
diff --git a/libs/libvmclient/src/lib.rs b/libs/libvmclient/src/lib.rs
index fe86504..7b576e6 100644
--- a/libs/libvmclient/src/lib.rs
+++ b/libs/libvmclient/src/lib.rs
@@ -45,7 +45,6 @@
 use shared_child::SharedChild;
 use std::io::{self, Read};
 use std::process::Command;
-use std::process::Stdio;
 use std::{
     fmt::{self, Debug, Formatter},
     fs::File,
@@ -91,9 +90,6 @@
         let (client_fd, server_fd) = posix_socketpair()?;
 
         let mut command = Command::new(VIRTMGR_PATH);
-        command.stdin(Stdio::null());
-        command.stdout(Stdio::null());
-        command.stderr(Stdio::null());
         // Can't use BorrowedFd as it doesn't implement Display
         command.arg("--rpc-server-fd").arg(format!("{}", server_fd.as_raw_fd()));
         command.arg("--ready-fd").arg(format!("{}", ready_fd.as_raw_fd()));