Method pause

vmm/src/cpu.rs:2603–2635

(&mut self)

impl Pausable for CpuManager {
    fn pause(&mut self) -> std::result::Result<(), MigratableError> {
        // Tell the vCPUs to pause themselves next time they exit
        self.vcpus_pause_signalled.store(true, Ordering::SeqCst);

        self.signal_vcpus()
            .map_err(|e| MigratableError::Pause(anyhow!("Error signalling vCPUs: {e}")))?;

        // Notify all guests (including Hyper-V / Windows) that the clock was
        // paused.  KVM_KVMCLOCK_CTRL updates internal KVM state that affects
        // both pvclock (Linux) and the Hyper-V TSC reference page, so it must
        // be called unconditionally.
        #[cfg(all(feature = "kvm", target_arch = "x86_64"))]
        for vcpu in self.vcpus.iter() {
            let vcpu = vcpu.lock().unwrap();
            vcpu.vcpu.notify_guest_clock_paused().map_err(|e| {
                MigratableError::Pause(anyhow!("Could not notify guest it has been paused {e:?}"))
            })?;
        }

        // The vCPU thread will change its paused state before parking, wait here for each
        // activated vCPU change their state to ensure they have parked.
        for state in self.vcpu_states.lock().unwrap().iter() {
            if state.active() {
                // wait for vCPU to update state
                while !state.paused.load(Ordering::SeqCst) {
                    // To avoid a priority inversion with the vCPU thread
                    thread::sleep(std::time::Duration::from_millis(1));
                }
            }
        }

        Ok(())
    }

    fn resume(&mut self) -> std::result::Result<(), MigratableError> {
        // Ensure that vCPUs keep running after being unpark() in