diff --git a/drivers/vhost/test.h b/drivers/vhost/test.h
new file mode 100644
index 0000000..1fef5df
--- /dev/null
+++ b/drivers/vhost/test.h
@@ -0,0 +1,7 @@
+#ifndef LINUX_VHOST_TEST_H
+#define LINUX_VHOST_TEST_H
+
+/* Start a given test on the virtio null device. 0 stops all tests. */
+#define VHOST_TEST_RUN _IOW(VHOST_VIRTIO, 0x31, int)
+
+#endif