Commit e965ffa7 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Kevin Wolf
Browse files

qdev: add qdev_add_vm_change_state_handler() 



Children sometimes depend on their parent's vm change state handler
having completed.  Add a vm change state handler API for devices that
guarantees tree depth ordering.

Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 60dbc5a1

hw/core/Makefile.objs

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ common-obj-$(CONFIG_SOFTMMU) += fw-path-provider.o 
common-obj-y += irq.o

common-obj-y += hotplug.o

common-obj-$(CONFIG_SOFTMMU) += nmi.o

common-obj-$(CONFIG_SOFTMMU) += vm-change-state-handler.o



common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o

common-obj-$(CONFIG_XILINX_AXI) += stream.o

hw/core/vm-change-state-handler.c

0 → 100644
+61 −0
Original line number Diff line number Diff line 
/*

 *  qdev vm change state handlers

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License,

 *  or (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, see <http://www.gnu.org/licenses/>.

 */



#include "qemu/osdep.h"

#include "hw/qdev.h"



static int qdev_get_dev_tree_depth(DeviceState *dev)

{

    int depth;



    for (depth = 0; dev; depth++) {

        BusState *bus = dev->parent_bus;



        if (!bus) {

            break;

        }



        dev = bus->parent;

    }



    return depth;

}



/**

 * qdev_add_vm_change_state_handler:

 * @dev: the device that owns this handler

 * @cb: the callback function to be invoked

 * @opaque: user data passed to the callback function

 *

 * This function works like qemu_add_vm_change_state_handler() except callbacks

 * are invoked in qdev tree depth order.  Ordering is desirable when callbacks

 * of children depend on their parent's callback having completed first.

 *

 * For example, when qdev_add_vm_change_state_handler() is used, a host

 * controller's callback is invoked before the children on its bus when the VM

 * starts running.  The order is reversed when the VM stops running.

 *

 * Returns: an entry to be freed with qemu_del_vm_change_state_handler()

 */

VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev,

                                                     VMChangeStateHandler *cb,

                                                     void *opaque)

{

    int depth = qdev_get_dev_tree_depth(dev);



    return qemu_add_vm_change_state_handler_prio(cb, opaque, depth);

}

include/hw/qdev-core.h

+5 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include "qom/object.h"

#include "hw/irq.h"

#include "hw/hotplug.h"

#include "sysemu/sysemu.h"



enum {

    DEV_NVECTORS_UNSPECIFIED = -1,
@@ -450,4 +451,8 @@ static inline bool qbus_is_hotpluggable(BusState *bus) 
void device_listener_register(DeviceListener *listener);

void device_listener_unregister(DeviceListener *listener);



VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev,

                                                     VMChangeStateHandler *cb,

                                                     void *opaque);



#endif