From: Zhao Liu <zhao1.liu@xxxxxxxxx>
Currently, the devices added by "-device" are linked via bus, and are
set the parent as peripheral-anon or peripheral containers of the
machine.
But this is not enough for building CPU topology hierarchies as:
1. The relationship between different CPU hierarchies is child<>
property other than link<> property, and they shouldn't be linked
using the special bus.
2. The canonical path of device is built from the child<> property, and
the well defined CPU topology hierarchies ask their canonical path to
reflect the correct topological relationship.
With these, the child<> property support is needed for QDev interface to
allow user to configure proper parent in "-device".
Introduce the "parent" option in "-device" to create the child<>
property. This option asks for the device id of the parent device.
Signed-off-by: Zhao Liu <zhao1.liu@xxxxxxxxx>
---
hw/xen/xen-legacy-backend.c | 2 +-
include/monitor/qdev.h | 3 ++-
system/qdev-monitor.c | 50 ++++++++++++++++++++++++++-----------
3 files changed, 38 insertions(+), 17 deletions(-)
diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
index 124dd5f3d687..70ad11c6287e 100644
--- a/hw/xen/xen-legacy-backend.c
+++ b/hw/xen/xen-legacy-backend.c
@@ -184,7 +184,7 @@ static struct XenLegacyDevice *xen_be_get_xendev(const char *type, int dom,
object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND);
OBJECT(xendev)->free = g_free;
qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev),
- &error_fatal);
+ NULL, &error_fatal);
qdev_realize(DEVICE(xendev), xen_sysbus, &error_fatal);
object_unref(OBJECT(xendev));
diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h
index f5fd6e6c1ffc..3d9d06158e5f 100644
--- a/include/monitor/qdev.h
+++ b/include/monitor/qdev.h
@@ -16,6 +16,7 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts, long *category,
* qdev_set_id: parent the device and set its id if provided.
* @dev: device to handle
* @id: id to be given to the device, or NULL.
+ * @parent: parent to be set for the device, or NULL.
*
* Returns: the id of the device in case of success; otherwise NULL.
*
@@ -34,6 +35,6 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts, long *category,
* returned string is owned by the corresponding child property and must
* not be freed by the caller.
*/
-const char *qdev_set_id(DeviceState *dev, char *id, Error **errp);
+const char *qdev_set_id(DeviceState *dev, char *id, char *parent, Error **errp);
#endif
diff --git a/system/qdev-monitor.c b/system/qdev-monitor.c
index 0261937b8462..8f56113eef65 100644
--- a/system/qdev-monitor.c
+++ b/system/qdev-monitor.c
@@ -587,22 +587,33 @@ static BusState *qbus_find(const char *path, Error **errp)
}
static Object *qdev_find_peripheral_parent(DeviceState *dev,
+ char *parent_id,
Error **errp)
{
Object *parent_obj, *obj = OBJECT(dev);
- parent_obj = uc_provide_default_parent(obj, errp);
- if (*errp) {
- return NULL;
- }
+ if (parent_id) {
+ parent_obj = object_resolve_path_from(qdev_get_peripheral(),
+ parent_id, NULL);
+ if (parent_obj) {
+ if (uc_check_user_parent(obj, parent_obj)) {
+ return parent_obj;
+ }
+ }
+ } else {
+ parent_obj = uc_provide_default_parent(obj, errp);
+ if (*errp) {
+ return NULL;
+ }
- if (parent_obj) {
- /*
- * Non-anonymous parents (under "/peripheral") are allowed to
- * be accessed to create child<> properties.
- */
- if (object_is_child_from(parent_obj, qdev_get_peripheral())) {
- return parent_obj;
+ if (parent_obj) {
+ /*
+ * Non-anonymous parents (under "/peripheral") are allowed to
+ * be accessed to create child<> properties.
+ */
+ if (object_is_child_from(parent_obj, qdev_get_peripheral())) {
+ return parent_obj;
+ }
}
}
@@ -628,7 +639,8 @@ static bool qdev_pre_check_device_id(char *id, Error **errp)
}
/* Takes ownership of @id, will be freed when deleting the device */
-const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
+const char *qdev_set_id(DeviceState *dev, char *id,
+ char *parent, Error **errp)
{
Object *parent_obj = NULL;
ObjectProperty *prop;
@@ -639,7 +651,7 @@ const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
uc = (UserChild *)object_dynamic_cast(OBJECT(dev), TYPE_USER_CHILD);
if (uc) {
- parent_obj = qdev_find_peripheral_parent(dev, errp);
+ parent_obj = qdev_find_peripheral_parent(dev, parent, errp);
if (*errp) {
goto err;
}
@@ -655,6 +667,11 @@ const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
goto err;
}
}
+ g_free(parent);
+ } else if (parent) {
+ error_setg(errp, "Only the device implemented user-child "
+ "interface supports `parent` option.");
+ goto err;
}
/*
@@ -684,6 +701,7 @@ const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
return prop->name;
err:
+ g_free(parent);
g_free(id);
return NULL;
}
@@ -694,7 +712,7 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts, long *category,
ERRP_GUARD();
DeviceClass *dc;
const char *driver, *path;
- char *id;
+ char *id, *parent;
DeviceState *dev = NULL;
BusState *bus = NULL;
@@ -772,12 +790,14 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts, long *category,
}
id = g_strdup(qdict_get_try_str(opts, "id"));
+ parent = g_strdup(qdict_get_try_str(opts, "parent"));
/* set properties */
dev->opts = qdict_clone_shallow(opts);
qdict_del(dev->opts, "driver");
qdict_del(dev->opts, "bus");
qdict_del(dev->opts, "id");
+ qdict_del(dev->opts, "parent");
object_set_properties_from_keyval(&dev->parent_obj, dev->opts, from_json,
errp);
@@ -789,7 +809,7 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts, long *category,
* set dev's parent and register its id.
* If it fails it means the id is already taken.
*/
- if (!qdev_set_id(dev, id, errp)) {
+ if (!qdev_set_id(dev, id, parent, errp)) {
goto err_del_dev;
}
--
2.34.1
