diff --git a/exec.c b/exec.c
index 140eb56..a6923ad 100644
--- a/exec.c
+++ b/exec.c
@@ -2587,6 +2587,24 @@
 }
 #endif
 
+#if !defined(CONFIG_USER_ONLY)
+
+/*
+ * A helper function for the _utterly broken_ virtio device model to find out if
+ * it's running on a big endian machine. Don't do this at home kids!
+ */
+bool virtio_is_big_endian(void);
+bool virtio_is_big_endian(void)
+{
+#if defined(TARGET_WORDS_BIGENDIAN)
+    return true;
+#else
+    return false;
+#endif
+}
+
+#endif
+
 #ifndef CONFIG_USER_ONLY
 bool cpu_physical_memory_is_io(hwaddr phys_addr)
 {