1 files changed, 39 insertions, 0 deletions
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 4a90549ad8..ad6c8fd537 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -36,7 +36,46 @@ void machine_set_cpu_numa_node(MachineState *machine,
                                const CpuInstanceProperties *props,
                                Error **errp);
 
+/**
+ * machine_class_allow_dynamic_sysbus_dev: Add type to list of valid devices
+ * @mc: Machine class
+ * @type: type to allow (should be a subtype of TYPE_SYS_BUS_DEVICE)
+ *
+ * Add the QOM type @type to the list of devices of which are subtypes
+ * of TYPE_SYS_BUS_DEVICE but which are still permitted to be dynamically
+ * created (eg by the user on the command line with -device).
+ * By default if the user tries to create any devices on the command line
+ * that are subtypes of TYPE_SYS_BUS_DEVICE they will get an error message;
+ * for the special cases which are permitted for this machine model, the
+ * machine model class init code must call this function to add them
+ * to the list of specifically permitted devices.
+ */
 void machine_class_allow_dynamic_sysbus_dev(MachineClass *mc, const char *type);
+
+/**
+ * device_is_dynamic_sysbus: test whether device is a dynamic sysbus device
+ * @mc: Machine class
+ * @dev: device to check
+ *
+ * Returns: true if @dev is a sysbus device on the machine's list
+ * of dynamically pluggable sysbus devices; otherwise false.
+ *
+ * This function checks whether @dev is a valid dynamic sysbus device,
+ * by first confirming that it is a sysbus device and then checking it
+ * against the list of permitted dynamic sysbus devices which has been
+ * set up by the machine using machine_class_allow_dynamic_sysbus_dev().
+ *
+ * It is valid to call this with something that is not a subclass of
+ * TYPE_SYS_BUS_DEVICE; the function will return false in this case.
+ * This allows hotplug callback functions to be written as:
+ *     if (device_is_dynamic_sysbus(mc, dev)) {
+ *         handle dynamic sysbus case;
+ *     } else if (some other kind of hotplug) {
+ *         handle that;
+ *     }
+ */
+bool device_is_dynamic_sysbus(MachineClass *mc, DeviceState *dev);
+
 /*
  * Checks that backend isn't used, preps it for exclusive usage and
  * returns migratable MemoryRegion provided by backend.