On Mon, Jun 22, 2026 at 04:46:48PM +0200, David Hildenbrand (Arm) wrote: > On 6/22/26 15:37, Denis V. Lunev wrote: > > virtballoon_remove() stops all of the balloon's asynchronous work (the > > free page reporting worker, the inflate/deflate and stats workers, the > > OOM notifier and the free page shrinker) before tearing the device > > down. A following change needs the same teardown from a .shutdown > > handler, so move it into a virtballoon_quiesce() helper. > > > > No functional change. > > > > Signed-off-by: Denis V. Lunev <[email protected]> > > --- > > drivers/virtio/virtio_balloon.c | 27 ++++++++++++++++++++------- > > 1 file changed, 20 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/virtio/virtio_balloon.c > > b/drivers/virtio/virtio_balloon.c > > index 088b3a0e6ce6..5b02d9191ac6 100644 > > --- a/drivers/virtio/virtio_balloon.c > > +++ b/drivers/virtio/virtio_balloon.c > > @@ -1098,26 +1098,39 @@ static void remove_common(struct virtio_balloon *vb) > > vb->vdev->config->del_vqs(vb->vdev); > > } > > > > -static void virtballoon_remove(struct virtio_device *vdev) > > +/* > > + * Stop all asynchronous balloon work. The device must still be alive so > > that > > + * in-flight requests can drain via the host before it is reset or freed. > > + */ > > +static void virtballoon_quiesce(struct virtio_balloon *vb) > > { > > - struct virtio_balloon *vb = vdev->priv; > > + struct virtio_device *vdev = vb->vdev; > > > > - if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) > > + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_REPORTING)) > > page_reporting_unregister(&vb->pr_dev_info); > > Most functions here grab mutexes and can sleep. I assume that's fine in > shutdown > context. > > Nothing jumped at me > > > Sashiko asks whether ->remove (hotunplug/driver-unloading) can follow a > ->shutdown callback. I don't know, seems questionable if this could happen and > should probably be handled by the core? > > If it's possible you'd have to remember that stuff was already quiesce'ed. > Maybe > simply by checking early in virtballoon_quiesce() whether vb->stop_update == > true already. > > -- > Cheers, > > David
I don't think it can happen. -- MST
