Separate out run module.
There are quite a few functions related to command_run now, so it makes
sense to put them in a separate file before I add more.
Bug: 187181124
Test: mm
Change-Id: I6ffed64edbdbbbe5af90abde1e23c10a9ab79927
diff --git a/vm/src/run.rs b/vm/src/run.rs
new file mode 100644
index 0000000..4237405
--- /dev/null
+++ b/vm/src/run.rs
@@ -0,0 +1,116 @@
+// 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.
+
+//! Command to run a VM.
+
+use crate::sync::AtomicFlag;
+use android_system_virtmanager::aidl::android::system::virtmanager::IVirtManager::IVirtManager;
+use android_system_virtmanager::aidl::android::system::virtmanager::IVirtualMachine::IVirtualMachine;
+use android_system_virtmanager::aidl::android::system::virtmanager::IVirtualMachineCallback::{
+ BnVirtualMachineCallback, IVirtualMachineCallback,
+};
+use android_system_virtmanager::binder::{
+ BinderFeatures, DeathRecipient, IBinder, ParcelFileDescriptor, Strong,
+};
+use android_system_virtmanager::binder::{Interface, Result as BinderResult};
+use anyhow::{Context, Error};
+use std::fs::File;
+use std::io;
+use std::os::unix::io::{AsRawFd, FromRawFd};
+use std::path::Path;
+
+/// Run a VM from the given configuration file.
+pub fn command_run(
+ virt_manager: Strong<dyn IVirtManager>,
+ config_path: &Path,
+ 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_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);
+
+ if daemonize {
+ // Pass the VM reference back to Virt Manager and have it hold it in the background.
+ virt_manager.debugHoldVmRef(&vm).context("Failed to pass VM to Virt Manager")
+ } else {
+ // Wait until the VM or VirtManager dies. If we just returned immediately then the
+ // IVirtualMachine Binder object would be dropped and the VM would be killed.
+ wait_for_vm(vm)
+ }
+}
+
+/// Wait until the given VM or the VirtManager itself dies.
+fn wait_for_vm(vm: Strong<dyn IVirtualMachine>) -> Result<(), Error> {
+ let dead = AtomicFlag::default();
+ let callback = BnVirtualMachineCallback::new_binder(
+ VirtualMachineCallback { dead: dead.clone() },
+ BinderFeatures::default(),
+ );
+ vm.registerCallback(&callback)?;
+ let death_recipient = wait_for_death(&mut vm.as_binder(), dead.clone())?;
+ dead.wait();
+ // Ensure that death_recipient isn't dropped before we wait on the flag, as it is removed
+ // from the Binder when it's dropped.
+ drop(death_recipient);
+ Ok(())
+}
+
+/// Raise the given flag when the given Binder object dies.
+///
+/// If the returned DeathRecipient is dropped then this will no longer do anything.
+fn wait_for_death(binder: &mut impl IBinder, dead: AtomicFlag) -> Result<DeathRecipient, Error> {
+ let mut death_recipient = DeathRecipient::new(move || {
+ println!("VirtManager died");
+ dead.raise();
+ });
+ binder.link_to_death(&mut death_recipient)?;
+ Ok(death_recipient)
+}
+
+#[derive(Debug)]
+struct VirtualMachineCallback {
+ dead: AtomicFlag,
+}
+
+impl Interface for VirtualMachineCallback {}
+
+impl IVirtualMachineCallback for VirtualMachineCallback {
+ fn onDied(&self, _cid: i32) -> BinderResult<()> {
+ println!("VM died");
+ self.dead.raise();
+ Ok(())
+ }
+}
+
+/// Safely duplicate the standard output file descriptor.
+fn duplicate_stdout() -> io::Result<File> {
+ let stdout_fd = io::stdout().as_raw_fd();
+ // Safe because this just duplicates a file descriptor which we know to be valid, and we check
+ // for an error.
+ let dup_fd = unsafe { libc::dup(stdout_fd) };
+ if dup_fd < 0 {
+ Err(io::Error::last_os_error())
+ } else {
+ // Safe because we have just duplicated the file descriptor so we own it, and `from_raw_fd`
+ // takes ownership of it.
+ Ok(unsafe { File::from_raw_fd(dup_fd) })
+ }
+}