Add VirtualMachineState enum rather than isRunning bool.
Keep track of payload state and enforce lifecycle expectations.
Bug: 199127239
Test: atest VirtualizationTestCases
Change-Id: I04646c96ec3c15854b6ae705e40979d0f2e29457
diff --git a/virtualizationservice/src/crosvm.rs b/virtualizationservice/src/crosvm.rs
index 5984ff0..abaa955 100644
--- a/virtualizationservice/src/crosvm.rs
+++ b/virtualizationservice/src/crosvm.rs
@@ -52,6 +52,18 @@
pub writable: bool,
}
+/// The lifecycle state which the payload in the VM has reported itself to be in.
+///
+/// Note that the order of enum variants is significant; only forward transitions are allowed by
+/// [`VmInstance::update_payload_state`].
+#[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
+pub enum PayloadState {
+ Starting,
+ Started,
+ Ready,
+ Finished,
+}
+
/// Information about a particular instance of a VM which is running.
#[derive(Debug)]
pub struct VmInstance {
@@ -76,6 +88,8 @@
pub callbacks: VirtualMachineCallbacks,
/// Input/output stream of the payload run in the VM.
pub stream: Mutex<Option<VsockStream>>,
+ /// The latest lifecycle state which the payload reported itself to be in.
+ payload_state: Mutex<PayloadState>,
}
impl VmInstance {
@@ -100,6 +114,7 @@
running: AtomicBool::new(true),
callbacks: Default::default(),
stream: Mutex::new(None),
+ payload_state: Mutex::new(PayloadState::Starting),
}
}
@@ -154,6 +169,24 @@
self.running.load(Ordering::Acquire)
}
+ /// Returns the last reported state of the VM payload.
+ pub fn payload_state(&self) -> PayloadState {
+ *self.payload_state.lock().unwrap()
+ }
+
+ /// Updates the payload state to the given value, if it is a valid state transition.
+ pub fn update_payload_state(&self, new_state: PayloadState) -> Result<(), Error> {
+ let mut state_locked = self.payload_state.lock().unwrap();
+ // Only allow forward transitions, e.g. from starting to started or finished, not back in
+ // the other direction.
+ if new_state > *state_locked {
+ *state_locked = new_state;
+ Ok(())
+ } else {
+ bail!("Invalid payload state transition from {:?} to {:?}", *state_locked, new_state)
+ }
+ }
+
/// Kill the crosvm instance.
pub fn kill(&self) {
// TODO: Talk to crosvm to shutdown cleanly.