[PATCH 3/3] vl: plug -object back into -readconfig

[Paolo Bonzini <pbonzini@redhat.com>]

Commit bc2f4fcb1d ("qom: move user_creatable_add_opts logic to vl.c
and QAPIfy it", 2021-03-19) switched the creation of objects from
qemu_opts_foreach to a bespoke QTAILQ in preparation for supporting JSON
syntax in -object.

Unfortunately in doing so it lost support for [object] stanzas in
configuration files and also for "-set object.ID.KEY=VAL".  The latter
is hard to re-establish and probably best solved by deprecating -set.
This patch uses the infrastructure introduced by the previous two
patches in order to parse QOM objects correctly from configuration
files.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 softmmu/vl.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/softmmu/vl.c b/softmmu/vl.c
index 90e491cc0c..a8abf8e740 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1708,9 +1708,15 @@ static void object_option_foreach_add(bool (*type_opt_predicate)(const char *))
     }
 }
 
+static void object_option_add_visitor(Visitor *v)
+{
+    ObjectOption *opt = g_new0(ObjectOption, 1);
+    visit_type_ObjectOptions(v, NULL, &opt->opts, &error_fatal);
+    QTAILQ_INSERT_TAIL(&object_opts, opt, next);
+}
+
 static void object_option_parse(const char *optarg)
 {
-    ObjectOption *opt;
     QemuOpts *opts;
     const char *type;
     Visitor *v;
@@ -1738,11 +1744,8 @@ static void object_option_parse(const char *optarg)
         v = opts_visitor_new(opts);
     }
 
-    opt = g_new0(ObjectOption, 1);
-    visit_type_ObjectOptions(v, NULL, &opt->opts, &error_fatal);
+    object_option_add_visitor(v);
     visit_free(v);
-
-    QTAILQ_INSERT_TAIL(&object_opts, opt, next);
 }
 
 /*
@@ -2122,12 +2125,21 @@ static int global_init_func(void *opaque, QemuOpts *opts, Error **errp)
  */
 static bool is_qemuopts_group(const char *group)
 {
+    if (g_str_equal(group, "object")) {
+        return false;
+    }
     return true;
 }
 
 static void qemu_record_config_group(const char *group, QDict *dict, bool from_json, Error **errp)
 {
-    abort();
+    if (g_str_equal(group, "object")) {
+        Visitor *v = qobject_input_visitor_new_keyval(QOBJECT(dict));
+        object_option_add_visitor(v);
+        visit_free(v);
+    } else {
+        abort();
+    }
 }
 
 /*
-- 
2.27.0