Reimplement qemu_register_reset() via qemu_register_resettable(). We define a new LegacyReset object which implements Resettable and defines its reset hold phase method to call a QEMUResetHandler function. When qemu_register_reset() is called, we create a new LegacyReset object and add it to the simulation_reset ResettableContainer. When qemu_unregister_reset() is called, we find the LegacyReset object in the container and remove it. This implementation of qemu_unregister_reset() means we'll end up scanning the ResetContainer's list of child objects twice, once to find the LegacyReset object, and once in g_ptr_array_remove(). In theory we could avoid this by having the ResettableContainer interface include a resettable_container_remove_with_equal_func() that took a callback method so that we could use g_ptr_array_find_with_equal_func() and g_ptr_array_remove_index(). But we don't expect qemu_unregister_reset() to be called frequently or in hot paths, and we expect the simulation_reset container to usually not have many children. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Message-id: 20240220160622.114437-9-peter.maydell@linaro.org Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
		
			
				
	
	
		
			127 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  Reset handlers.
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 *
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 * Copyright (c) 2003-2008 Fabrice Bellard
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 * Copyright (c) 2016 Red Hat, Inc.
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 * Copyright (c) 2024 Linaro, Ltd.
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
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 * of this software and associated documentation files (the "Software"), to deal
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 * in the Software without restriction, including without limitation the rights
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 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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 * copies of the Software, and to permit persons to whom the Software is
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 * furnished to do so, subject to the following conditions:
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 *
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 * The above copyright notice and this permission notice shall be included in
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 * all copies or substantial portions of the Software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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 * THE SOFTWARE.
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 */
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#ifndef QEMU_SYSEMU_RESET_H
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#define QEMU_SYSEMU_RESET_H
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#include "qapi/qapi-events-run-state.h"
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typedef void QEMUResetHandler(void *opaque);
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/**
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 * qemu_register_resettable: Register an object to be reset
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 * @obj: object to be reset: it must implement the Resettable interface
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 *
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 * Register @obj on the list of objects which will be reset when the
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 * simulation is reset. These objects will be reset in the order
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 * they were added, using the three-phase Resettable protocol,
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 * so first all objects go through the enter phase, then all objects
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 * go through the hold phase, and then finally all go through the
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 * exit phase.
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 *
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 * It is not permitted to register or unregister reset functions or
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 * resettable objects from within any of the reset phase methods of @obj.
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 *
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 * We assume that the caller holds the BQL.
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 */
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void qemu_register_resettable(Object *obj);
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/**
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 * qemu_unregister_resettable: Unregister an object to be reset
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 * @obj: object to unregister
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 *
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 * Remove @obj from the list of objects which are reset when the
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 * simulation is reset. It must have been previously added to
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 * the list via qemu_register_resettable().
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 *
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 * We assume that the caller holds the BQL.
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 */
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void qemu_unregister_resettable(Object *obj);
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/**
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 * qemu_register_reset: Register a callback for system reset
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 * @func: function to call
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 * @opaque: opaque data to pass to @func
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 *
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 * Register @func on the list of functions which are called when the
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 * entire system is reset. Functions registered with this API and
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 * Resettable objects registered with qemu_register_resettable() are
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 * handled together, in the order in which they were registered.
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 * Functions registered with this API are called in the 'hold' phase
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 * of the 3-phase reset.
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 *
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 * In general this function should not be used in new code where possible;
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 * for instance, device model reset is better accomplished using the
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 * methods on DeviceState.
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 *
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 * It is not permitted to register or unregister reset functions or
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 * resettable objects from within the @func callback.
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 *
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 * We assume that the caller holds the BQL.
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 */
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void qemu_register_reset(QEMUResetHandler *func, void *opaque);
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/**
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 * qemu_register_reset_nosnapshotload: Register a callback for system reset
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 * @func: function to call
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 * @opaque: opaque data to pass to @func
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 *
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 * This is the same as qemu_register_reset(), except that @func is
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 * not called if the reason that the system is being reset is to
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 * put it into a clean state prior to loading a snapshot (i.e. for
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 * SHUTDOWN_CAUSE_SNAPSHOT_LOAD).
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 */
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void qemu_register_reset_nosnapshotload(QEMUResetHandler *func, void *opaque);
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/**
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 * qemu_unregister_reset: Unregister a system reset callback
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 * @func: function registered with qemu_register_reset()
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 * @opaque: the same opaque data that was passed to qemu_register_reset()
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 *
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 * Undo the effects of a qemu_register_reset(). The @func and @opaque
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 * must both match the arguments originally used with qemu_register_reset().
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 *
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 * We assume that the caller holds the BQL.
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 */
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void qemu_unregister_reset(QEMUResetHandler *func, void *opaque);
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/**
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 * qemu_devices_reset: Perform a complete system reset
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 * @reason: reason for the reset
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 *
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 * This function performs the low-level work needed to do a complete reset
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 * of the system (calling all the callbacks registered with
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 * qemu_register_reset() and resetting all the Resettable objects registered
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 * with qemu_register_resettable()). It should only be called by the code in a
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 * MachineClass reset method.
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 *
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 * If you want to trigger a system reset from, for instance, a device
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 * model, don't use this function. Use qemu_system_reset_request().
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 */
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void qemu_devices_reset(ShutdownCause reason);
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#endif
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