libxl_qmp: Introduce libxl__qmp_set_global_dirty_log.

This function will enable or disable the global dirty log on QEMU,
used during a migration.

Backport of xen-unstable patch:
: HG changeset patch
: User Anthony PERARD <anthony.perard@citrix.com>
: Date 1349693135 -3600
: Node ID d4aec9eff7e6d15c2805957af620c82555553b3e
: Parent  f3890916496445c97d6778d6c986b0270ff707f2
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

tools/libxl/libxl_internal.h

@@ -1400,6 +1400,8 @@ _hidden int libxl__qmp_stop(libxl__gc *gc, int domid);
 _hidden int libxl__qmp_resume(libxl__gc *gc, int domid);
 /* Save current QEMU state into fd. */
 _hidden int libxl__qmp_save(libxl__gc *gc, int domid, const char *filename);
+/* Set dirty bitmap logging status */
+_hidden int libxl__qmp_set_global_dirty_log(libxl__gc *gc, int domid, bool enable);
 /* close and free the QMP handler */
 _hidden void libxl__qmp_close(libxl__qmp_handler *qmp);
 /* remove the socket file, if the file has already been removed,

tools/libxl/libxl_qmp.c

@@ -658,7 +658,6 @@ static void qmp_parameters_add_string(libxl__gc *gc,
     qmp_parameters_common_add(gc, param, name, obj);
 }
 
-#if 0
 static void qmp_parameters_add_bool(libxl__gc *gc,
                                     libxl__json_object **param,
                                     const char *name, bool b)
@@ -669,7 +668,6 @@ static void qmp_parameters_add_bool(libxl__gc *gc,
     obj->u.b = b;
     qmp_parameters_common_add(gc, param, name, obj);
 }
-#endif
 
 #define QMP_PARAMETERS_SPRINTF(args, name, format, ...) \
     qmp_parameters_add_string(gc, args, name, \
@@ -905,6 +903,16 @@ int libxl__qmp_resume(libxl__gc *gc, int domid)
     return qmp_run_command(gc, domid, "cont", NULL, NULL, NULL);
 }
 
+int libxl__qmp_set_global_dirty_log(libxl__gc *gc, int domid, bool enable)
+{
+    libxl__json_object *args = NULL;
+
+    qmp_parameters_add_bool(gc, &args, "enable", enable);
+
+    return qmp_run_command(gc, domid, "xen-set-global-dirty-log", args,
+                           NULL, NULL);
+}
+
 int libxl__qmp_initializations(libxl__gc *gc, uint32_t domid,
                                const libxl_domain_config *guest_config)
 {