qdev: Avoid using string visitor for properties

The only thing the string visitor adds compared to a keyval visitor is
list support. git grep for 'visit_start_list' and 'visit.*List' shows
that devices don't make use of this.

In a world with a QAPIfied command line interface, the keyval visitor is
used to parse the command line. In order to make sure that no devices
start using this feature that would make backwards compatibility harder,
just switch away from object_property_parse(), which internally uses the
string visitor, to a keyval visitor and object_property_set().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20211008133442.141332-8-kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

softmmu/qdev-monitor.c

@@ -28,6 +28,8 @@
 #include "qapi/qmp/dispatch.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
+#include "qapi/qmp/qstring.h"
+#include "qapi/qobject-input-visitor.h"
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
 #include "qemu/help_option.h"
@@ -198,16 +200,28 @@ static int set_property(void *opaque, const char *name, const char *value,
                         Error **errp)
 {
     Object *obj = opaque;
+    QString *val;
+    Visitor *v;
+    int ret;
 
     if (strcmp(name, "driver") == 0)
         return 0;
     if (strcmp(name, "bus") == 0)
         return 0;
 
-    if (!object_property_parse(obj, name, value, errp)) {
-        return -1;
+    val = qstring_from_str(value);
+    v = qobject_input_visitor_new_keyval(QOBJECT(val));
+
+    if (!object_property_set(obj, name, v, errp)) {
+        ret = -1;
+        goto out;
     }
-    return 0;
+
+    ret = 0;
+out:
+    visit_free(v);
+    qobject_unref(val);
+    return ret;
 }
 
 static const char *find_typename_by_alias(const char *alias)