diff --git a/virtualizationmanager/src/aidl.rs b/virtualizationmanager/src/aidl.rs
index 602c670..ca23305 100644
--- a/virtualizationmanager/src/aidl.rs
+++ b/virtualizationmanager/src/aidl.rs
@@ -19,9 +19,9 @@
 use crate::composite::make_composite_image;
 use crate::crosvm::{CrosvmConfig, DiskFile, PayloadState, VmContext, VmInstance, VmState};
 use crate::debug_config::DebugConfig;
+use crate::dt_overlay::{create_device_tree_overlay, DtAddition, VM_REFERENCE_DT_ON_HOST_PATH, VM_DT_OVERLAY_MAX_SIZE, VM_DT_OVERLAY_PATH};
 use crate::payload::{add_microdroid_payload_images, add_microdroid_system_images, add_microdroid_vendor_image};
 use crate::selinux::{getfilecon, SeContext};
-use crate::reference_dt;
 use android_os_permissions_aidl::aidl::android::os::IPermissionController;
 use android_system_virtualizationcommon::aidl::android::system::virtualizationcommon::{
     Certificate::Certificate,
@@ -68,6 +68,7 @@
     Status, StatusCode, Strong,
     IntoBinderResult,
 };
+use cstr::cstr;
 use disk::QcowFile;
 use glob::glob;
 use lazy_static::lazy_static;
@@ -79,6 +80,7 @@
 use semver::VersionReq;
 use std::collections::HashSet;
 use std::convert::TryInto;
+use std::fs;
 use std::ffi::CStr;
 use std::fs::{canonicalize, read_dir, remove_file, File, OpenOptions};
 use std::io::{BufRead, BufReader, Error, ErrorKind, Seek, SeekFrom, Write};
@@ -376,13 +378,35 @@
             check_gdb_allowed(config)?;
         }
 
-        let reference_dt = reference_dt::parse_reference_dt(&temporary_directory)
-            .context("Failed to create VM reference DT")
-            .or_service_specific_exception(-1)?;
-        if reference_dt.is_none() {
-            warn!("VM reference DT doesn't exist");
+        // Currently, VirtMgr adds the host copy of reference DT & an untrusted prop (instance-id)
+        let mut dt_additions = Vec::with_capacity(2);
+        let host_ref_dt = Path::new(VM_REFERENCE_DT_ON_HOST_PATH);
+        if host_ref_dt.exists()
+            && read_dir(host_ref_dt).or_service_specific_exception(-1)?.next().is_some()
+        {
+            dt_additions.push(DtAddition::FromPath(host_ref_dt));
+        } else {
+            warn!("VM reference DT doesn't exist in host DT");
         }
 
+        if cfg!(llpvm_changes) {
+            // TODO(b/291213394): Replace this with a per-VM instance Id.
+            let instance_id = b"sixtyfourbyteslonghardcoded_indeed_sixtyfourbyteslonghardcoded_h";
+            dt_additions.push(DtAddition::AvfUntrustedProp(cstr!("instance-id"), &instance_id[..]));
+        }
+
+        let device_tree_overlay = if !dt_additions.is_empty() {
+            let dt_output = temporary_directory.join(VM_DT_OVERLAY_PATH);
+            let mut data = [0_u8; VM_DT_OVERLAY_MAX_SIZE];
+            let fdt = create_device_tree_overlay(&mut data, &dt_additions)
+                .map_err(|e| anyhow!("Failed to create DT overlay, {e:?}"))
+                .or_service_specific_exception(-1)?;
+            fs::write(&dt_output, fdt.as_slice()).or_service_specific_exception(-1)?;
+            Some(File::open(dt_output).or_service_specific_exception(-1)?)
+        } else {
+            None
+        };
+
         let debug_level = match config {
             VirtualMachineConfig::AppConfig(config) => config.debugLevel,
             _ => DebugLevel::NONE,
@@ -531,7 +555,7 @@
             gdb_port,
             vfio_devices,
             dtbo,
-            reference_dt,
+            device_tree_overlay,
         };
         let instance = Arc::new(
             VmInstance::new(
diff --git a/virtualizationmanager/src/crosvm.rs b/virtualizationmanager/src/crosvm.rs
index 84c60bd..2c23441 100644
--- a/virtualizationmanager/src/crosvm.rs
+++ b/virtualizationmanager/src/crosvm.rs
@@ -118,7 +118,7 @@
     pub gdb_port: Option<NonZeroU16>,
     pub vfio_devices: Vec<VfioDevice>,
     pub dtbo: Option<File>,
-    pub reference_dt: Option<File>,
+    pub device_tree_overlay: Option<File>,
 }
 
 /// A disk image to pass to crosvm for a VM.
@@ -896,10 +896,8 @@
         .arg("--socket")
         .arg(add_preserved_fd(&mut preserved_fds, &control_server_socket.as_raw_descriptor()));
 
-    if let Some(reference_dt) = &config.reference_dt {
-        command
-            .arg("--device-tree-overlay")
-            .arg(add_preserved_fd(&mut preserved_fds, reference_dt));
+    if let Some(dt_overlay) = &config.device_tree_overlay {
+        command.arg("--device-tree-overlay").arg(add_preserved_fd(&mut preserved_fds, dt_overlay));
     }
 
     append_platform_devices(&mut command, &mut preserved_fds, &config)?;
diff --git a/virtualizationmanager/src/dt_overlay.rs b/virtualizationmanager/src/dt_overlay.rs
new file mode 100644
index 0000000..c2d3c07
--- /dev/null
+++ b/virtualizationmanager/src/dt_overlay.rs
@@ -0,0 +1,133 @@
+// 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.
+
+//! This module support creating AFV related overlays, that can then be appended to DT by VM.
+
+use anyhow::{anyhow, Result};
+use cstr::cstr;
+use fsfdt::FsFdt;
+use libfdt::Fdt;
+use std::ffi::CStr;
+use std::path::Path;
+
+pub(crate) const AVF_NODE_NAME: &CStr = cstr!("avf");
+pub(crate) const UNTRUSTED_NODE_NAME: &CStr = cstr!("untrusted");
+pub(crate) const VM_REFERENCE_DT_ON_HOST_PATH: &str = "/proc/device-tree/avf/reference";
+pub(crate) const VM_DT_OVERLAY_PATH: &str = "vm_dt_overlay.dtbo";
+pub(crate) const VM_DT_OVERLAY_MAX_SIZE: usize = 2000;
+
+/// Provide ways to modify the device tree.
+#[derive(PartialEq, Eq)]
+pub(crate) enum DtAddition<'a> {
+    /// Include the device tree at given path.
+    FromPath(&'a Path),
+    /// Include a property in /avf/untrusted node. This node is used to specify host provided
+    /// properties such as `instance-id`.
+    /// pVM firmware does minimal validation of properties in this node.
+    AvfUntrustedProp(&'a CStr, &'a [u8]),
+}
+
+/// Given a list of `dt_additions`, return a Device tree overlay containing those!
+/// Example: with `create_device_tree_overlay(_, DtAddition::AvfUntrustedProp("instance-id", _))`
+/// ```
+///   {
+///     fragment@0 {
+///         target-path = "/";
+///         __overlay__ {
+///             avf {
+///                 untrusted { instance-id = [0x01 0x23 .. ] }
+///               }
+///             };
+///         };
+///     };
+/// };
+/// ```
+pub(crate) fn create_device_tree_overlay<'a>(
+    buffer: &'a mut [u8],
+    dt_additions: &[DtAddition],
+) -> Result<&'a mut Fdt> {
+    if dt_additions.is_empty() {
+        return Err(anyhow!("Expected non empty list of device tree additions"));
+    }
+
+    let (additional_properties, additional_paths): (Vec<_>, _) =
+        dt_additions.iter().partition(|o| matches!(o, DtAddition::AvfUntrustedProp(_, _)));
+
+    let fdt =
+        Fdt::create_empty_tree(buffer).map_err(|e| anyhow!("Failed to create empty Fdt: {e:?}"))?;
+    let mut root = fdt.root_mut().map_err(|e| anyhow!("Failed to get root: {e:?}"))?;
+    let mut node =
+        root.add_subnode(cstr!("fragment@0")).map_err(|e| anyhow!("Failed to fragment: {e:?}"))?;
+    node.setprop(cstr!("target-path"), b"/\0")
+        .map_err(|e| anyhow!("Failed to set target-path: {e:?}"))?;
+    let mut node = node
+        .add_subnode(cstr!("__overlay__"))
+        .map_err(|e| anyhow!("Failed to __overlay__ node: {e:?}"))?;
+
+    if !additional_properties.is_empty() {
+        let mut node = node
+            .add_subnode(AVF_NODE_NAME)
+            .map_err(|e| anyhow!("Failed to add avf node: {e:?}"))?;
+        let mut node = node
+            .add_subnode(UNTRUSTED_NODE_NAME)
+            .map_err(|e| anyhow!("Failed to add /avf/untrusted node: {e:?}"))?;
+        for prop in additional_properties {
+            if let DtAddition::AvfUntrustedProp(name, value) = prop {
+                node.setprop(name, value).map_err(|e| anyhow!("Failed to set property: {e:?}"))?;
+            }
+        }
+    }
+
+    for path in additional_paths {
+        if let DtAddition::FromPath(path) = path {
+            fdt.append(cstr!("/fragment@0/__overlay__"), path)?;
+        }
+    }
+    fdt.pack().map_err(|e| anyhow!("Failed to pack DT overlay, {e:?}"))?;
+
+    Ok(fdt)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn empty_overlays_not_allowed() {
+        let mut buffer = vec![0_u8; VM_DT_OVERLAY_MAX_SIZE];
+        let res = create_device_tree_overlay(&mut buffer, &[]);
+        assert!(res.is_err());
+    }
+
+    #[test]
+    fn untrusted_prop_test() {
+        let mut buffer = vec![0_u8; VM_DT_OVERLAY_MAX_SIZE];
+        let prop_name = cstr!("XOXO");
+        let prop_val_input = b"OXOX";
+        let fdt = create_device_tree_overlay(
+            &mut buffer,
+            &[DtAddition::AvfUntrustedProp(prop_name, prop_val_input)],
+        )
+        .unwrap();
+
+        let prop_value_dt = fdt
+            .node(cstr!("/fragment@0/__overlay__/avf/untrusted"))
+            .unwrap()
+            .expect("/avf/untrusted node doesn't exist")
+            .getprop(prop_name)
+            .unwrap()
+            .expect("Prop not found!");
+        assert_eq!(prop_value_dt, prop_val_input, "Unexpected property value");
+    }
+}
diff --git a/virtualizationmanager/src/main.rs b/virtualizationmanager/src/main.rs
index 2e542c3..b2a734a 100644
--- a/virtualizationmanager/src/main.rs
+++ b/virtualizationmanager/src/main.rs
@@ -19,8 +19,8 @@
 mod composite;
 mod crosvm;
 mod debug_config;
+mod dt_overlay;
 mod payload;
-mod reference_dt;
 mod selinux;
 
 use crate::aidl::{GLOBAL_SERVICE, VirtualizationService};
diff --git a/virtualizationmanager/src/reference_dt.rs b/virtualizationmanager/src/reference_dt.rs
deleted file mode 100644
index 797ee3c..0000000
--- a/virtualizationmanager/src/reference_dt.rs
+++ /dev/null
@@ -1,93 +0,0 @@
-// 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.
-
-//! Functions for VM reference DT
-
-use anyhow::{anyhow, Result};
-use cstr::cstr;
-use fsfdt::FsFdt;
-use libfdt::Fdt;
-use std::fs;
-use std::fs::File;
-use std::path::Path;
-
-const VM_REFERENCE_DT_ON_HOST_PATH: &str = "/proc/device-tree/avf/reference";
-const VM_REFERENCE_DT_NAME: &str = "vm_reference_dt.dtbo";
-const VM_REFERENCE_DT_MAX_SIZE: usize = 2000;
-
-// Parses to VM reference if exists.
-// TODO(b/318431695): Allow to parse from custom VM reference DT
-pub(crate) fn parse_reference_dt(out_dir: &Path) -> Result<Option<File>> {
-    parse_reference_dt_internal(
-        Path::new(VM_REFERENCE_DT_ON_HOST_PATH),
-        &out_dir.join(VM_REFERENCE_DT_NAME),
-    )
-}
-
-fn parse_reference_dt_internal(dir_path: &Path, fdt_path: &Path) -> Result<Option<File>> {
-    if !dir_path.exists() || fs::read_dir(dir_path)?.next().is_none() {
-        return Ok(None);
-    }
-
-    let mut data = vec![0_u8; VM_REFERENCE_DT_MAX_SIZE];
-
-    let fdt = Fdt::create_empty_tree(&mut data)
-        .map_err(|e| anyhow!("Failed to create an empty DT, {e:?}"))?;
-    let mut root = fdt.root_mut().map_err(|e| anyhow!("Failed to find the DT root, {e:?}"))?;
-    let mut fragment = root
-        .add_subnode(cstr!("fragment@0"))
-        .map_err(|e| anyhow!("Failed to create the fragment@0, {e:?}"))?;
-    fragment
-        .setprop(cstr!("target-path"), b"/\0")
-        .map_err(|e| anyhow!("Failed to set target-path, {e:?}"))?;
-    fragment
-        .add_subnode(cstr!("__overlay__"))
-        .map_err(|e| anyhow!("Failed to create the __overlay__, {e:?}"))?;
-
-    fdt.append(cstr!("/fragment@0/__overlay__"), dir_path)?;
-
-    fdt.pack().map_err(|e| anyhow!("Failed to pack VM reference DT, {e:?}"))?;
-    fs::write(fdt_path, fdt.as_slice())?;
-
-    Ok(Some(File::open(fdt_path)?))
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_parse_reference_dt_from_empty_dir() {
-        let empty_dir = tempfile::TempDir::new().unwrap();
-        let test_dir = tempfile::TempDir::new().unwrap();
-
-        let empty_dir_path = empty_dir.path();
-        let fdt_path = test_dir.path().join("test.dtb");
-
-        let fdt_file = parse_reference_dt_internal(empty_dir_path, &fdt_path).unwrap();
-
-        assert!(fdt_file.is_none());
-    }
-
-    #[test]
-    fn test_parse_reference_dt_from_empty_reference() {
-        let fdt_file = parse_reference_dt_internal(
-            Path::new("/this/path/would/not/exists"),
-            Path::new("test.dtb"),
-        )
-        .unwrap();
-
-        assert!(fdt_file.is_none());
-    }
-}