Commit 249d4172 authored by Andreas Färber's avatar Andreas Färber Committed by Anthony Liguori
Browse files

qdev: Prepare "realized" property



Introduce the QOM realizefn suggested by Anthony.
Detailed documentation is supplied in the qdev header.

For now this implements a default DeviceClass::realize callback that
just wraps DeviceClass::init, which it deprecates.
Once all devices have been converted to DeviceClass::realize,
DeviceClass::init is to be removed.
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarAndreas Färber <afaerber@suse.de>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent 7983c8a3
......@@ -20,11 +20,59 @@ enum {
typedef int (*qdev_initfn)(DeviceState *dev);
typedef int (*qdev_event)(DeviceState *dev);
typedef void (*qdev_resetfn)(DeviceState *dev);
typedef void (*DeviceRealize)(DeviceState *dev, Error **errp);
typedef void (*DeviceUnrealize)(DeviceState *dev, Error **errp);
struct VMStateDescription;
/**
* DeviceClass:
* @props: Properties accessing state fields.
* @realize: Callback function invoked when the #DeviceState:realized
* property is changed to %true. The default invokes @init if not %NULL.
* @unrealize: Callback function invoked when the #DeviceState:realized
* property is changed to %false.
* @init: Callback function invoked when the #DeviceState::realized property
* is changed to %true. Deprecated, new types inheriting directly from
* TYPE_DEVICE should use @realize instead, new leaf types should consult
* their respective parent type.
*
* # Realization #
* Devices are constructed in two stages,
* 1) object instantiation via object_initialize() and
* 2) device realization via #DeviceState:realized property.
* The former may not fail (it might assert or exit), the latter may return
* error information to the caller and must be re-entrant.
* Trivial field initializations should go into #TypeInfo.instance_init.
* Operations depending on @props static properties should go into @realize.
* After successful realization, setting static properties will fail.
*
* As an interim step, the #DeviceState:realized property is set by deprecated
* functions qdev_init() and qdev_init_nofail().
* In the future, devices will propagate this state change to their children
* and along busses they expose.
* The point in time will be deferred to machine creation, so that values
* set in @realize will not be introspectable beforehand. Therefore devices
* must not create children during @realize; they should initialize them via
* object_initialize() in their own #TypeInfo.instance_init and forward the
* realization events appropriately.
*
* The @init callback is considered private to a particular bus implementation
* (immediate abstract child types of TYPE_DEVICE). Derived leaf types set an
* "init" callback on their parent class instead.
* Any type may override the @realize and/or @unrealize callbacks but needs
* to call (and thus save) the parent type's implementation if so desired.
* Usually this means storing the previous value of, e.g., @realized inside
* the type's class structure and overwriting it with a function that first
* invokes the stored callback, then performs any additional steps.
* If a type derived directly from TYPE_DEVICE implements @realize, it does
* not need to implement @init and therefore does not need to store and call
* #DeviceClass' default @realize callback.
*/
typedef struct DeviceClass {
/*< private >*/
ObjectClass parent_class;
/*< public >*/
const char *fw_name;
const char *desc;
......@@ -33,12 +81,14 @@ typedef struct DeviceClass {
/* callbacks */
void (*reset)(DeviceState *dev);
DeviceRealize realize;
DeviceUnrealize unrealize;
/* device state */
const struct VMStateDescription *vmsd;
/* Private to qdev / bus. */
qdev_initfn init;
qdev_initfn init; /* TODO remove, once users are converted to realize */
qdev_event unplug;
qdev_event exit;
const char *bus_type;
......
......@@ -148,37 +148,30 @@ DeviceState *qdev_try_create(BusState *bus, const char *type)
Return 0 on success. */
int qdev_init(DeviceState *dev)
{
DeviceClass *dc = DEVICE_GET_CLASS(dev);
int rc;
Error *local_err = NULL;
assert(!dev->realized);
rc = dc->init(dev);
if (rc < 0) {
object_property_set_bool(OBJECT(dev), true, "realized", &local_err);
if (local_err != NULL) {
error_free(local_err);
qdev_free(dev);
return rc;
return -1;
}
return 0;
}
if (!OBJECT(dev)->parent) {
static int unattached_count = 0;
gchar *name = g_strdup_printf("device[%d]", unattached_count++);
object_property_add_child(container_get(qdev_get_machine(),
"/unattached"),
name, OBJECT(dev), NULL);
g_free(name);
}
static void device_realize(DeviceState *dev, Error **err)
{
DeviceClass *dc = DEVICE_GET_CLASS(dev);
if (qdev_get_vmsd(dev)) {
vmstate_register_with_alias_id(dev, -1, qdev_get_vmsd(dev), dev,
dev->instance_id_alias,
dev->alias_required_for_version);
}
dev->realized = true;
if (dev->hotplugged) {
device_reset(dev);
if (dc->init) {
int rc = dc->init(dev);
if (rc < 0) {
error_setg(err, "Device initialization failed.");
return;
}
}
return 0;
}
void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
......@@ -641,6 +634,55 @@ void qdev_property_add_static(DeviceState *dev, Property *prop,
assert_no_error(local_err);
}
static bool device_get_realized(Object *obj, Error **err)
{
DeviceState *dev = DEVICE(obj);
return dev->realized;
}
static void device_set_realized(Object *obj, bool value, Error **err)
{
DeviceState *dev = DEVICE(obj);
DeviceClass *dc = DEVICE_GET_CLASS(dev);
Error *local_err = NULL;
if (value && !dev->realized) {
if (dc->realize) {
dc->realize(dev, &local_err);
}
if (!obj->parent && local_err == NULL) {
static int unattached_count;
gchar *name = g_strdup_printf("device[%d]", unattached_count++);
object_property_add_child(container_get(qdev_get_machine(),
"/unattached"),
name, obj, &local_err);
g_free(name);
}
if (qdev_get_vmsd(dev) && local_err == NULL) {
vmstate_register_with_alias_id(dev, -1, qdev_get_vmsd(dev), dev,
dev->instance_id_alias,
dev->alias_required_for_version);
}
if (dev->hotplugged && local_err == NULL) {
device_reset(dev);
}
} else if (!value && dev->realized) {
if (dc->unrealize) {
dc->unrealize(dev, &local_err);
}
}
if (local_err != NULL) {
error_propagate(err, local_err);
return;
}
dev->realized = value;
}
static void device_initfn(Object *obj)
{
DeviceState *dev = DEVICE(obj);
......@@ -655,6 +697,9 @@ static void device_initfn(Object *obj)
dev->instance_id_alias = -1;
dev->realized = false;
object_property_add_bool(obj, "realized",
device_get_realized, device_set_realized, NULL);
class = object_get_class(OBJECT(dev));
do {
for (prop = DEVICE_CLASS(class)->props; prop && prop->name; prop++) {
......@@ -714,7 +759,10 @@ static void device_unparent(Object *obj)
static void device_class_init(ObjectClass *class, void *data)
{
DeviceClass *dc = DEVICE_CLASS(class);
class->unparent = device_unparent;
dc->realize = device_realize;
}
void device_reset(DeviceState *dev)
......
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