Commit 707ff800 authored by Paul Durrant's avatar Paul Durrant Committed by Stefano Stabellini
Browse files

Add device listener interface 



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: default avatarPaul Durrant <paul.durrant@citrix.com>
Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 74acb997

hw/core/qdev.c

+53 −0
Original line number Diff line number Diff line
@@ -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) {

include/hw/qdev-core.h

+10 −0
Original line number Diff line number Diff line
@@ -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

include/qemu/typedefs.h

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ typedef struct BusState BusState; 
typedef struct CharDriverState CharDriverState;

typedef struct CompatProperty CompatProperty;

typedef struct DeviceState DeviceState;

typedef struct DeviceListener DeviceListener;

typedef struct DisplayChangeListener DisplayChangeListener;

typedef struct DisplayState DisplayState;

typedef struct DisplaySurface DisplaySurface;