[Qemu-devel] [PATCH 4/8] vl: add -late-object to create QOM objects after machine init

[Amit Shah]

From: Anthony Liguori <aligu...@us.ibm.com>

In order to create qdev objects via -late-object, we almost always have to
specify the parent_bus which is usually created during machine init.  Until we
properly support two stage init, introduce a -late-object option that allows for
creation of objects post-machine init.

Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
---
 qemu-config.c   |   10 ++++++++++
 qemu-options.hx |   12 ++++++++++++
 vl.c            |   14 +++++++++++---
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/qemu-config.c b/qemu-config.c
index d695bdf..537acd1 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -662,6 +662,15 @@ QemuOptsList qemu_object_opts = {
     },
 };
 
+QemuOptsList qemu_late_object_opts = {
+    .name = "late-object",
+    .implied_opt_name = "qom-type",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_late_object_opts.head),
+    .desc = {
+        { }
+    },
+};
+
 static QemuOptsList *vm_config_groups[32] = {
     &qemu_drive_opts,
     &qemu_chardev_opts,
@@ -679,6 +688,7 @@ static QemuOptsList *vm_config_groups[32] = {
     &qemu_iscsi_opts,
     &qemu_sandbox_opts,
     &qemu_object_opts,
+    &qemu_late_object_opts,
     NULL,
 };
 
diff --git a/qemu-options.hx b/qemu-options.hx
index b72151e..a0fe038 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2860,6 +2860,18 @@ DEF("object", HAS_ARG, QEMU_OPTION_object,
     "                '/objects' path.\n",
     QEMU_ARCH_ALL)
 
+DEF("late-object", HAS_ARG, QEMU_OPTION_late_object,
+    "-late-object TYPENAME[,PROP1=VALUE1,...]\n"
+    "                create an new object of type TYPENAME setting 
properties\n"
+    "                in the order they are specified.  Note that the 'id'\n"
+    "                property must be set.  These objects are placed in the\n"
+    "                '/objects' path.\n"
+    "\n"
+    "                Late objects are made after machine\n"
+    "                initialization so they can refer to objects created by\n"
+    "                the machine init function.\n",
+    QEMU_ARCH_ALL)
+
 HXCOMM This is the last statement. Insert new options before this line!
 STEXI
 @end table
diff --git a/vl.c b/vl.c
index eabf47b..61b4666 100644
--- a/vl.c
+++ b/vl.c
@@ -2395,13 +2395,14 @@ static int object_create(QemuOpts *opts, void *opaque)
     }
 
     obj = object_new(type);
-    if (qemu_opt_foreach(opts, object_set_property, obj, 1) < 0) {
-        return -1;
-    }
 
     object_property_add_child(container_get(object_get_root(), "/objects"),
                               id, obj, NULL);
 
+    if (qemu_opt_foreach(opts, object_set_property, obj, 1) < 0) {
+        return -1;
+    }
+
     return 0;
 }
 
@@ -3360,6 +3361,9 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_object:
                 opts = qemu_opts_parse(qemu_find_opts("object"), optarg, 1);
                 break;
+            case QEMU_OPTION_late_object:
+                opts = qemu_opts_parse(qemu_find_opts("late-object"), optarg, 
1);
+                break;
             default:
                 os_parse_cmd_args(popt->index, optarg);
             }
@@ -3706,6 +3710,10 @@ int main(int argc, char **argv, char **envp)
 
     current_machine = machine;
 
+    if (qemu_opts_foreach(qemu_find_opts("late-object"), object_create, NULL, 
0) != 0) {
+        exit(1);
+    }
+
     /* init USB devices */
     if (usb_enabled) {
         if (foreach_device_config(DEV_USB, usb_parse) < 0)
-- 
1.7.7.6