qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
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vm-change-state-handler.c (2091B)

      1 /*
      2  *  qdev vm change state handlers
      3  *
      4  *  This program is free software; you can redistribute it and/or modify
      5  *  it under the terms of the GNU General Public License as published by
      6  *  the Free Software Foundation; either version 2 of the License,
      7  *  or (at your option) any later version.
      8  *
      9  *  This program is distributed in the hope that it will be useful,
     10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     12  *  GNU General Public License for more details.
     13  *
     14  *  You should have received a copy of the GNU General Public License
     15  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
     16  */
     17 
     18 #include "qemu/osdep.h"
     19 #include "hw/qdev-core.h"
     20 #include "sysemu/runstate.h"
     21 
     22 static int qdev_get_dev_tree_depth(DeviceState *dev)
     23 {
     24     int depth;
     25 
     26     for (depth = 0; dev; depth++) {
     27         BusState *bus = dev->parent_bus;
     28 
     29         if (!bus) {
     30             break;
     31         }
     32 
     33         dev = bus->parent;
     34     }
     35 
     36     return depth;
     37 }
     38 
     39 /**
     40  * qdev_add_vm_change_state_handler:
     41  * @dev: the device that owns this handler
     42  * @cb: the callback function to be invoked
     43  * @opaque: user data passed to the callback function
     44  *
     45  * This function works like qemu_add_vm_change_state_handler() except callbacks
     46  * are invoked in qdev tree depth order.  Ordering is desirable when callbacks
     47  * of children depend on their parent's callback having completed first.
     48  *
     49  * For example, when qdev_add_vm_change_state_handler() is used, a host
     50  * controller's callback is invoked before the children on its bus when the VM
     51  * starts running.  The order is reversed when the VM stops running.
     52  *
     53  * Returns: an entry to be freed with qemu_del_vm_change_state_handler()
     54  */
     55 VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev,
     56                                                      VMChangeStateHandler *cb,
     57                                                      void *opaque)
     58 {
     59     int depth = qdev_get_dev_tree_depth(dev);
     60 
     61     return qemu_add_vm_change_state_handler_prio(cb, opaque, depth);
     62 }