virtio_balloon: fix towards_target when deflating balloon
[linux-2.6.git] / drivers / virtio / virtio_balloon.c
index bfef604..62eab43 100644 (file)
@@ -158,7 +158,7 @@ static inline s64 towards_target(struct virtio_balloon *vb)
        vb->vdev->config->get(vb->vdev,
                              offsetof(struct virtio_balloon_config, num_pages),
                              &v, sizeof(v));
-       return v - vb->num_pages;
+       return (s64)v - vb->num_pages;
 }
 
 static void update_balloon_size(struct virtio_balloon *vb)