diff --git a/vmconfig/src/lib.rs b/vmconfig/src/lib.rs
new file mode 100644
index 0000000..c9385f3
--- /dev/null
+++ b/vmconfig/src/lib.rs
@@ -0,0 +1,175 @@
+// Copyright 2021, 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.
+
+//! Struct for VM configuration with JSON (de)serialization and AIDL parcelables
+
+use android_system_virtualizationservice::{
+    aidl::android::system::virtualizationservice::DiskImage::DiskImage as AidlDiskImage,
+    aidl::android::system::virtualizationservice::Partition::Partition as AidlPartition,
+    aidl::android::system::virtualizationservice::VirtualMachineConfig::VirtualMachineConfig,
+    binder::ParcelFileDescriptor,
+};
+
+use anyhow::{bail, Context, Error, Result};
+use serde::{Deserialize, Serialize};
+use std::fs::{File, OpenOptions};
+use std::io::BufReader;
+use std::path::{Path, PathBuf};
+
+/// Configuration for a particular VM to be started.
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+pub struct VmConfig {
+    /// The filename of the kernel image, if any.
+    pub kernel: Option<PathBuf>,
+    /// The filename of the initial ramdisk for the kernel, if any.
+    pub initrd: Option<PathBuf>,
+    /// Parameters to pass to the kernel. As far as the VMM and boot protocol are concerned this is
+    /// just a string, but typically it will contain multiple parameters separated by spaces.
+    pub params: Option<String>,
+    /// The bootloader to use. If this is supplied then the kernel and initrd must not be supplied;
+    /// the bootloader is instead responsibly for loading the kernel from one of the disks.
+    pub bootloader: Option<PathBuf>,
+    /// Disk images to be made available to the VM.
+    #[serde(default)]
+    pub disks: Vec<DiskImage>,
+    /// Whether the VM should be a protected VM.
+    #[serde(default)]
+    pub protected: bool,
+}
+
+impl VmConfig {
+    /// Ensure that the configuration has a valid combination of fields set, or return an error if
+    /// not.
+    pub fn validate(&self) -> Result<(), Error> {
+        if self.bootloader.is_none() && self.kernel.is_none() {
+            bail!("VM must have either a bootloader or a kernel image.");
+        }
+        if self.bootloader.is_some() && (self.kernel.is_some() || self.initrd.is_some()) {
+            bail!("Can't have both bootloader and kernel/initrd image.");
+        }
+        for disk in &self.disks {
+            if disk.image.is_none() == disk.partitions.is_empty() {
+                bail!("Exactly one of image and partitions must be specified. (Was {:?}.)", disk);
+            }
+        }
+        Ok(())
+    }
+
+    /// Load the configuration for a VM from the given JSON file, and check that it is valid.
+    pub fn load(file: &File) -> Result<VmConfig, Error> {
+        let buffered = BufReader::new(file);
+        let config: VmConfig = serde_json::from_reader(buffered)?;
+        config.validate()?;
+        Ok(config)
+    }
+
+    /// Convert the `VmConfig` to a [`VirtualMachineConfig`] which can be passed to the Virt
+    /// Manager.
+    pub fn to_parcelable(&self) -> Result<VirtualMachineConfig, Error> {
+        Ok(VirtualMachineConfig {
+            kernel: maybe_open_parcel_file(&self.kernel, false)?,
+            initrd: maybe_open_parcel_file(&self.initrd, false)?,
+            params: self.params.clone(),
+            bootloader: maybe_open_parcel_file(&self.bootloader, false)?,
+            disks: self.disks.iter().map(DiskImage::to_parcelable).collect::<Result<_, Error>>()?,
+            protected_vm: self.protected,
+        })
+    }
+}
+
+/// A disk image to be made available to the VM.
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+pub struct DiskImage {
+    /// The filename of the disk image, if it already exists. Exactly one of this and `partitions`
+    /// must be specified.
+    #[serde(default)]
+    pub image: Option<PathBuf>,
+    /// A set of partitions to be assembled into a composite image.
+    #[serde(default)]
+    pub partitions: Vec<Partition>,
+    /// Whether this disk should be writable by the VM.
+    pub writable: bool,
+}
+
+impl DiskImage {
+    fn to_parcelable(&self) -> Result<AidlDiskImage, Error> {
+        let partitions =
+            self.partitions.iter().map(Partition::to_parcelable).collect::<Result<_>>()?;
+        Ok(AidlDiskImage {
+            image: maybe_open_parcel_file(&self.image, self.writable)?,
+            writable: self.writable,
+            partitions,
+        })
+    }
+}
+
+/// A partition to be assembled into a composite image.
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+pub struct Partition {
+    /// A label for the partition.
+    pub label: String,
+    /// The filename of the partition image.
+    #[serde(default)]
+    pub path: Option<PathBuf>,
+    /// The filename of the partition image.
+    #[serde(default)]
+    pub paths: Vec<PathBuf>,
+    /// Whether the partition should be writable.
+    #[serde(default)]
+    pub writable: bool,
+}
+
+impl Partition {
+    fn to_parcelable(&self) -> Result<AidlPartition> {
+        if !self.paths.is_empty() {
+            if self.path.is_some() {
+                bail!("Partition {} contains both path/paths", &self.label);
+            }
+            let images = self
+                .paths
+                .iter()
+                .map(|path| open_parcel_file(&path, self.writable))
+                .collect::<Result<Vec<_>, _>>()?;
+            Ok(AidlPartition { images, writable: self.writable, label: self.label.to_owned() })
+        } else {
+            let path = self.path.as_ref().ok_or_else(|| {
+                Error::msg(format!("Partition {} doesn't set path/paths", &self.label))
+            })?;
+            Ok(AidlPartition {
+                images: vec![open_parcel_file(&path, self.writable)?],
+                writable: self.writable,
+                label: self.label.to_owned(),
+            })
+        }
+    }
+}
+
+/// Try to open the given file and wrap it in a [`ParcelFileDescriptor`].
+fn open_parcel_file(filename: &Path, writable: bool) -> Result<ParcelFileDescriptor> {
+    Ok(ParcelFileDescriptor::new(
+        OpenOptions::new()
+            .read(true)
+            .write(writable)
+            .open(filename)
+            .with_context(|| format!("Failed to open {:?}", filename))?,
+    ))
+}
+
+/// If the given filename is `Some`, try to open it and wrap it in a [`ParcelFileDescriptor`].
+fn maybe_open_parcel_file(
+    filename: &Option<PathBuf>,
+    writable: bool,
+) -> Result<Option<ParcelFileDescriptor>> {
+    filename.as_deref().map(|filename| open_parcel_file(filename, writable)).transpose()
+}