@@ -628,8 +628,13 @@ static void virtio_balloon_free_page_done(VirtIOBalloon *s)
{
VirtIODevice *vdev = VIRTIO_DEVICE(s);
- s->free_page_report_status = FREE_PAGE_REPORT_S_DONE;
- virtio_notify_config(vdev);
+ if (s->free_page_report_status != FREE_PAGE_REPORT_S_DONE) {
+ /* See virtio_balloon_free_page_stop() */
+ qemu_mutex_lock(&s->free_page_lock);
+ s->free_page_report_status = FREE_PAGE_REPORT_S_DONE;
+ qemu_mutex_unlock(&s->free_page_lock);
+ virtio_notify_config(vdev);
+ }
}
static int
@@ -653,17 +658,26 @@ virtio_balloon_free_page_report_notify(NotifierWithReturn *n, void *data)
case PRECOPY_NOTIFY_SETUP:
precopy_enable_free_page_optimization();
break;
- case PRECOPY_NOTIFY_COMPLETE:
- case PRECOPY_NOTIFY_CLEANUP:
case PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC:
virtio_balloon_free_page_stop(dev);
break;
case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC:
if (vdev->vm_running) {
virtio_balloon_free_page_start(dev);
- } else {
- virtio_balloon_free_page_done(dev);
+ break;
}
+ /*
+ * Set S_DONE before migrating the vmstate, so the guest will reuse
+ * all hinted pages once running on the destination. Fall through.
+ */
+ case PRECOPY_NOTIFY_CLEANUP:
+ /*
+ * Especially, if something goes wrong during precopy or if migration
+ * is canceled, we have to properly communicate S_DONE to the VM.
+ */
+ virtio_balloon_free_page_done(dev);
+ break;
+ case PRECOPY_NOTIFY_COMPLETE:
break;
default:
virtio_error(vdev, "%s: %d reason unknown", __func__, pnd->reason);