External/cloud-hypervisor
1
0
Fork 0
mirror of https://github.com/cloud-hypervisor/cloud-hypervisor.git synced 2025-02-01 17:35:19 +00:00
Code Issues Packages Projects Releases Wiki Activity

vmm: Ensure vcpu pause is synchronised

Browse Source 
The pause of vcpu is async now, which makes the vm pause is not
synchronised. As virtio device calls paused_sync wait() to make
sure device_manager pause synchronously, if we make vcpu pause
synchronously, the vm pause can be synchronously then. After
vm.pause() returns the vm is really paused now.

This patch adds a AtomicBool variable to mark vcpu paused state,
to make sure the pause of CpuManager is synchronised.

Signed-off-by: Yi Wang <foxywang@tencent.com>
This commit is contained in:
Yi Wang 2023-07-20 15:41:23 +08:00 committed by Bo Chen
parent 83c8c3c913
commit 92cf2816b0
1 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
vmm/src/cpu.rs
View File

@ -552,6 +552,7 @@ struct VcpuState {
handle: Option<thread::JoinHandle<()>>,
kill: Arc<AtomicBool>,
vcpu_run_interrupted: Arc<AtomicBool>,
paused: Arc<AtomicBool>,
}
impl VcpuState {
@ -864,6 +865,7 @@ impl CpuManager {
.vcpu_run_interrupted
.clone();
let panic_vcpu_run_interrupted = vcpu_run_interrupted.clone();
let vcpu_paused = self.vcpu_states[usize::from(vcpu_id)].paused.clone();
// Prepare the CPU set the current vCPU is expected to run onto.
let cpuset = self.affinity.get(&vcpu_id).map(|host_cpus| {
@ -970,6 +972,8 @@ impl CpuManager {
}
vcpu_run_interrupted.store(true, Ordering::SeqCst);
vcpu_paused.store(true, Ordering::SeqCst);
while vcpu_pause_signalled.load(Ordering::SeqCst) {
thread::park();
}
@ -2092,6 +2096,17 @@ impl Pausable for CpuManager {
}
}
// The vCPU thread will change its paused state before parking, wait here for each
// actived vCPU change their state to ensure they have parked.
for state in self.vcpu_states.iter() {
if state.active() {
while !state.paused.load(Ordering::SeqCst) {
// To avoid a priority inversion with the vCPU thread
thread::sleep(std::time::Duration::from_millis(1));
}
}
}
Ok(())
}
@ -2108,6 +2123,7 @@ impl Pausable for CpuManager {
// boolean. Since it'll be set to false, they will exit their pause loop
// and go back to vmx root.
for state in self.vcpu_states.iter() {
state.paused.store(false, Ordering::SeqCst);
state.unpark_thread();
}
Ok(())