virtio: update balloon size in balloon "probe"

The following commit '4739658e217a (virtio_balloon: Use a workqueue
instead of "vballoon" kthread)' has added a regression. Original code with
kthread starts the thread inside probe and checks the necessity to update
balloon inside the thread immediately.

Nowadays the code behaves differently. Work is queued only on the first
command from the host after the negotiation. Thus there is a window
especially at the guest startup or the module reloading when the balloon
size is not updated until the notification from the host.

This patch adds balloon size check at the end of the probe to match
original behaviour.

Signed-off-by: Konstantin Neumoin <kneumoin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 4e7003db12c4a4385034231d23cd1318006eca04..181793f078524ae8c06751d4b03677a132b4a7c3 100644 (file)
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -577,6 +577,8 @@ static int virtballoon_probe(struct virtio_device *vdev)
 
        virtio_device_ready(vdev);
 
+       if (towards_target(vb))
+               virtballoon_changed(vdev);
        return 0;
 
 out_del_vqs: