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 return qdev_add_vm_change_state_handler_full(dev, cb, NULL, opaque); 60 } 61 62 /* 63 * Exactly like qdev_add_vm_change_state_handler() but passes a prepare_cb 64 * argument too. 65 */ 66 VMChangeStateEntry *qdev_add_vm_change_state_handler_full( 67 DeviceState *dev, VMChangeStateHandler *cb, 68 VMChangeStateHandler *prepare_cb, void *opaque) 69 { 70 int depth = qdev_get_dev_tree_depth(dev); 71 72 return qemu_add_vm_change_state_handler_prio_full(cb, prepare_cb, opaque, 73 depth); 74 } 75