DeviceClass::hide() is a better alternative to
DeviceListener::hide_device() that does not need listener registration
and is contained in specific devices that need the hiding capability.
Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com>
---
include/hw/qdev-core.h | 33 +++++++++++++++++++++++----------
system/qdev-monitor.c | 11 +++++++++++
2 files changed, 34 insertions(+), 10 deletions(-)
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 6befbca311..de221b6f02 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -56,16 +56,15 @@
* Hiding a device
* ---------------
*
- * To hide a device, a DeviceListener function hide_device() needs to
- * be registered. It can be used to defer adding a device and
- * therefore hide it from the guest. The handler registering to this
- * DeviceListener can save the QOpts passed to it for re-using it
- * later. It must return if it wants the device to be hidden or
- * visible. When the handler function decides the device shall be
- * visible it will be added with qdev_device_add() and realized as any
- * other device. Otherwise qdev_device_add() will return early without
- * adding the device. The guest will not see a "hidden" device until
- * it was marked visible and qdev_device_add called again.
+ * To hide a device, a DeviceClass function hide() needs to be registered. It
+ * can be used to defer adding a device and therefore hide it from the guest.
+ * The handler can save the QOpts passed to it for re-using it later. It must
+ * return if it wants the device to be hidden or visible. When the handler
+ * function decides the device shall be visible it will be added with
+ * qdev_device_add() and realized as any other device. Otherwise
+ * qdev_device_add() will return early without adding the device. The guest
+ * will not see a "hidden" device until it was marked visible and
+ * qdev_device_add called again.
*
*/
@@ -90,6 +89,8 @@ typedef enum DeviceCategory {
DEVICE_CATEGORY_MAX
} DeviceCategory;
+typedef bool (*DeviceHide)(DeviceClass *dc, const QDict *device_opts,
+ bool from_json, Error **errp);
typedef void (*DeviceRealize)(DeviceState *dev, Error **errp);
typedef void (*DeviceUnrealize)(DeviceState *dev);
typedef void (*DeviceReset)(DeviceState *dev);
@@ -151,6 +152,18 @@ struct DeviceClass {
bool hotpluggable;
/* callbacks */
+ /**
+ * @hide: informs qdev if a device should be visible or hidden.
+ *
+ * This callback is called upon init of the DeviceState.
+ * We can hide a failover device depending for example on the device
+ * opts.
+ *
+ * On errors, it returns false and errp is set. Device creation
+ * should fail in this case.
+ */
+ DeviceHide hide;
+
/**
* @reset: deprecated device reset method pointer
*
diff --git a/system/qdev-monitor.c b/system/qdev-monitor.c
index 71c00f62ee..639beabc5f 100644
--- a/system/qdev-monitor.c
+++ b/system/qdev-monitor.c
@@ -669,6 +669,17 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts,
return NULL;
}
+ if (dc->hide) {
+ if (dc->hide(dc, opts, from_json, errp)) {
+ if (bus && !qbus_is_hotpluggable(bus)) {
+ error_setg(errp, QERR_BUS_NO_HOTPLUG, bus->name);
+ }
+ return NULL;
+ } else if (*errp) {
+ return NULL;
+ }
+ }
+
if (phase_check(PHASE_MACHINE_READY) && bus && !qbus_is_hotpluggable(bus))
{
error_setg(errp, QERR_BUS_NO_HOTPLUG, bus->name);
return NULL;
--
2.43.0
