qapi: add QMP input visitor

A type of Visiter class that is used to walk a qobject's
structure and assign each entry to the corresponding native C type.
Command marshaling function will use this to pull out QMP command
parameters recieved over the wire and pass them as native arguments
to the corresponding C functions.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
diff --git a/qapi/qmp-input-visitor.h b/qapi/qmp-input-visitor.h
new file mode 100644
index 0000000..3f798f0
--- /dev/null
+++ b/qapi/qmp-input-visitor.h
@@ -0,0 +1,27 @@
+/*
+ * Input Visitor
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef QMP_INPUT_VISITOR_H
+#define QMP_INPUT_VISITOR_H
+
+#include "qapi-visit-core.h"
+#include "qobject.h"
+
+typedef struct QmpInputVisitor QmpInputVisitor;
+
+QmpInputVisitor *qmp_input_visitor_new(QObject *obj);
+void qmp_input_visitor_cleanup(QmpInputVisitor *v);
+
+Visitor *qmp_input_get_visitor(QmpInputVisitor *v);
+
+#endif