Add ethtool -g support to virtio_net

Add support for reporting ring sizes via ethtool -g to the virtio_net
driver.

Signed-off-by: Rick Jones <rick.jones2@hp.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 68b91368..4acf888 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -529,4 +529,14 @@
 }
 EXPORT_SYMBOL_GPL(vring_transport_features);
 
+/* return the size of the vring within the virtqueue */
+unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
+{
+
+	struct vring_virtqueue *vq = to_vvq(_vq);
+
+	return vq->vring.num;
+}
+EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
+
 MODULE_LICENSE("GPL");