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 65261a7244fcea2e3d0c2562e40e6ba4e5b1bc48..8ffec6d9c24086ee9e122a95f5dfda5ff1cebc00 100644 (file)
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -122,6 +122,9 @@ 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).