On 05/12/2014 11:50, Paul Durrant wrote:
> The Xen ioreq-server API, introduced in Xen 4.5, requires that PCI device
> models explicitly register with Xen for config space accesses. This patch
> adds a listener interface into qdev-core which can be used by the Xen
> interface code to monitor for arrival and departure of PCI devices.
>
> Signed-off-by: Paul Durrant <paul.durr...@citrix.com>
> Cc: Michael S. Tsirkin <m...@redhat.com>
> Cc: Andreas Faerber" <afaer...@suse.de>
> Cc: Paolo Bonzini <pbonz...@redhat.com>
> Cc: Peter Crosthwaite <peter.crosthwa...@xilinx.com>
> Cc: Igor Mammedov <imamm...@redhat.com>
> Cc: Markus Armbruster <arm...@redhat.com>
> Cc: Thomas Huth <th...@linux.vnet.ibm.com>
> Cc: Christian Borntraeger <borntrae...@de.ibm.com>
> ---
> hw/core/qdev.c | 53
> +++++++++++++++++++++++++++++++++++++++++++++++
> include/hw/qdev-core.h | 10 +++++++++
> include/qemu/typedefs.h | 1 +
> 3 files changed, 64 insertions(+)
>
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 35fd00d..76ff9ef 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -189,6 +189,56 @@ int qdev_init(DeviceState *dev)
> return 0;
> }
>
> +static QTAILQ_HEAD(device_listeners, DeviceListener) device_listeners
> + = QTAILQ_HEAD_INITIALIZER(device_listeners);
> +
> +enum ListenerDirection { Forward, Reverse };
> +
> +#define DEVICE_LISTENER_CALL(_callback, _direction, _args...) \
> + do { \
> + DeviceListener *_listener; \
> + \
> + switch (_direction) { \
> + case Forward: \
> + QTAILQ_FOREACH(_listener, &device_listeners, link) { \
> + if (_listener->_callback) { \
> + _listener->_callback(_listener, ##_args); \
> + } \
> + } \
> + break; \
> + case Reverse: \
> + QTAILQ_FOREACH_REVERSE(_listener, &device_listeners, \
> + device_listeners, link) { \
> + if (_listener->_callback) { \
> + _listener->_callback(_listener, ##_args); \
> + } \
> + } \
> + break; \
> + default: \
> + abort(); \
> + } \
> + } while (0)
> +
> +static int device_listener_add(DeviceState *dev, void *opaque)
> +{
> + DEVICE_LISTENER_CALL(realize, Forward, dev);
> +
> + return 0;
> +}
> +
> +void device_listener_register(DeviceListener *listener)
> +{
> + QTAILQ_INSERT_TAIL(&device_listeners, listener, link);
> +
> + qbus_walk_children(sysbus_get_default(), NULL, NULL, device_listener_add,
> + NULL, NULL);
> +}
> +
> +void device_listener_unregister(DeviceListener *listener)
> +{
> + QTAILQ_REMOVE(&device_listeners, listener, link);
> +}
> +
> static void device_realize(DeviceState *dev, Error **errp)
> {
> DeviceClass *dc = DEVICE_GET_CLASS(dev);
> @@ -994,6 +1044,8 @@ static void device_set_realized(Object *obj, bool value,
> Error **errp)
> goto fail;
> }
>
> + DEVICE_LISTENER_CALL(realize, Forward, dev);
> +
> hotplug_ctrl = qdev_get_hotplug_handler(dev);
> if (hotplug_ctrl) {
> hotplug_handler_plug(hotplug_ctrl, dev, &local_err);
> @@ -1035,6 +1087,7 @@ static void device_set_realized(Object *obj, bool
> value, Error **errp)
> dc->unrealize(dev, local_errp);
> }
> dev->pending_deleted_event = true;
> + DEVICE_LISTENER_CALL(unrealize, Reverse, dev);
> }
>
> if (local_err != NULL) {
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index 589bbe7..15a226f 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -165,6 +165,12 @@ struct DeviceState {
> int alias_required_for_version;
> };
>
> +struct DeviceListener {
> + void (*realize)(DeviceListener *listener, DeviceState *dev);
> + void (*unrealize)(DeviceListener *listener, DeviceState *dev);
> + QTAILQ_ENTRY(DeviceListener) link;
> +};
> +
> #define TYPE_BUS "bus"
> #define BUS(obj) OBJECT_CHECK(BusState, (obj), TYPE_BUS)
> #define BUS_CLASS(klass) OBJECT_CLASS_CHECK(BusClass, (klass), TYPE_BUS)
> @@ -376,4 +382,8 @@ static inline bool qbus_is_hotpluggable(BusState *bus)
> {
> return bus->hotplug_handler;
> }
> +
> +void device_listener_register(DeviceListener *listener);
> +void device_listener_unregister(DeviceListener *listener);
> +
> #endif
> diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
> index 3475177..4bb4938 100644
> --- a/include/qemu/typedefs.h
> +++ b/include/qemu/typedefs.h
> @@ -20,6 +20,7 @@ typedef struct Property Property;
> typedef struct PropertyInfo PropertyInfo;
> typedef struct CompatProperty CompatProperty;
> typedef struct DeviceState DeviceState;
> +typedef struct DeviceListener DeviceListener;
> typedef struct BusState BusState;
> typedef struct BusClass BusClass;
>
>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
Thanks!
Paolo
