qemu/include/hw/hotplug.h

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/*
* Hotplug handler interface.
*
* Copyright (c) 2014 Red Hat Inc.
*
* Authors:
* Igor Mammedov <imammedo@redhat.com>,
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef HOTPLUG_H
#define HOTPLUG_H
#include "qom/object.h"
#define TYPE_HOTPLUG_HANDLER "hotplug-handler"
typedef struct HotplugHandlerClass HotplugHandlerClass;
DECLARE_CLASS_CHECKERS(HotplugHandlerClass, HOTPLUG_HANDLER,
TYPE_HOTPLUG_HANDLER)
#define HOTPLUG_HANDLER(obj) \
INTERFACE_CHECK(HotplugHandler, (obj), TYPE_HOTPLUG_HANDLER)
typedef struct HotplugHandler HotplugHandler;
/**
* hotplug_fn:
* @plug_handler: a device performing plug/uplug action
* @plugged_dev: a device that has been (un)plugged
* @errp: returns an error if this function fails
*/
typedef void (*hotplug_fn)(HotplugHandler *plug_handler,
DeviceState *plugged_dev, Error **errp);
/**
* HotplugDeviceClass:
*
* Interface to be implemented by a device performing
* hardware (un)plug functions.
*
* @parent: Opaque parent interface.
* @pre_plug: pre plug callback called at start of device.realize(true)
* @plug: plug callback called at end of device.realize(true).
* @unplug_request: unplug request callback.
* Used as a means to initiate device unplug for devices that
* require asynchronous unplug handling.
* @unplug: unplug callback.
* Used for device removal with devices that implement
* asynchronous and synchronous (surprise) removal.
pci: fix 'hotplugglable' property behavior Currently the property may flip its state during VM bring up or just doesn't work as the name implies. In particular with PCIE root port that has 'hotplug={on|off}' property, and when it's turned off, one would expect 'hotpluggable' == false for any devices attached to it. Which is not the case since qbus_is_hotpluggable() used by the property just checks for presence of any hotplug_handler set on bus. The problem is that name BusState::hotplug_handler from its inception is misnomer, as it handles not only hotplug but also in many cases coldplug as well (i.e. generic wiring interface), and it's fine to have hotplug_handler set on bus while it doesn't support hotplug (ex. pcie-slot with hotplug=off). Another case of root port flipping 'hotpluggable' state when ACPI PCI hotplug is enabled in this case root port with 'hotplug=off' starts as hotpluggable and then later on, pcihp hotplug_handler clears hotplug_handler explicitly after checking root port's 'hotplug' property. So root-port hotpluggablity check sort of works if pcihp is enabled but is broken if pcihp is disabled. One way to deal with the issue is to ask hotplug_handler if bus it controls is hotpluggable or not. To do that add is_hotpluggable_bus() hook to HotplugHandler interface and use it in 'hotpluggable' property + teach pcie-slot to actually look into 'hotplug' property state before deciding if bus is hotpluggable. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20230302161543.286002-13-imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-02 19:15:21 +03:00
* @is_hotpluggable_bus: called to check if bus/its parent allow hotplug on bus
*/
struct HotplugHandlerClass {
/* <private> */
InterfaceClass parent;
/* <public> */
hotplug_fn pre_plug;
hotplug_fn plug;
hotplug_fn unplug_request;
hotplug_fn unplug;
pci: fix 'hotplugglable' property behavior Currently the property may flip its state during VM bring up or just doesn't work as the name implies. In particular with PCIE root port that has 'hotplug={on|off}' property, and when it's turned off, one would expect 'hotpluggable' == false for any devices attached to it. Which is not the case since qbus_is_hotpluggable() used by the property just checks for presence of any hotplug_handler set on bus. The problem is that name BusState::hotplug_handler from its inception is misnomer, as it handles not only hotplug but also in many cases coldplug as well (i.e. generic wiring interface), and it's fine to have hotplug_handler set on bus while it doesn't support hotplug (ex. pcie-slot with hotplug=off). Another case of root port flipping 'hotpluggable' state when ACPI PCI hotplug is enabled in this case root port with 'hotplug=off' starts as hotpluggable and then later on, pcihp hotplug_handler clears hotplug_handler explicitly after checking root port's 'hotplug' property. So root-port hotpluggablity check sort of works if pcihp is enabled but is broken if pcihp is disabled. One way to deal with the issue is to ask hotplug_handler if bus it controls is hotpluggable or not. To do that add is_hotpluggable_bus() hook to HotplugHandler interface and use it in 'hotpluggable' property + teach pcie-slot to actually look into 'hotplug' property state before deciding if bus is hotpluggable. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20230302161543.286002-13-imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-02 19:15:21 +03:00
bool (*is_hotpluggable_bus)(HotplugHandler *plug_handler, BusState *bus);
};
/**
* hotplug_handler_plug:
*
* Call #HotplugHandlerClass.plug callback of @plug_handler.
*/
void hotplug_handler_plug(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp);
/**
* hotplug_handler_pre_plug:
*
* Call #HotplugHandlerClass.pre_plug callback of @plug_handler.
*/
void hotplug_handler_pre_plug(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp);
/**
* hotplug_handler_unplug_request:
*
* Calls #HotplugHandlerClass.unplug_request callback of @plug_handler.
*/
void hotplug_handler_unplug_request(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp);
/**
* hotplug_handler_unplug:
*
* Calls #HotplugHandlerClass.unplug callback of @plug_handler.
*/
void hotplug_handler_unplug(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp);
#endif