virtio: add ability to iterate over vqs

commit 24a7e4d20783c0514850f24a5c41ede46ab058f0 upstream.

For cleanup it's helpful to be able to simply scan all vqs and discard
all data. Add an iterator to do that.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index d5eb5479a4254356a39e76c805743d35458dd07b..3f8f35053260df79a7f814715d1e853fe6b349a9 100644 (file)
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -143,6 +143,9 @@ int virtio_device_freeze(struct virtio_device *dev);
 int virtio_device_restore(struct virtio_device *dev);
 #endif
 
+#define virtio_device_for_each_vq(vdev, vq) \
+       list_for_each_entry(vq, &vdev->vqs, list)
+
 /**
  * virtio_driver - operations for a virtio I/O driver
  * @driver: underlying device driver (populate name and owner).