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: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 589bbe7360..15a226f24a 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 f2bbaaf86a..cde3314896 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -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;