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 "system/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 * @cb_ret: the callback function with return value to be invoked 44 * @opaque: user data passed to the callback function 45 * 46 * This function works like qemu_add_vm_change_state_handler() except callbacks 47 * are invoked in qdev tree depth order. Ordering is desirable when callbacks 48 * of children depend on their parent's callback having completed first. 49 * 50 * For example, when qdev_add_vm_change_state_handler() is used, a host 51 * controller's callback is invoked before the children on its bus when the VM 52 * starts running. The order is reversed when the VM stops running. 53 * 54 * Note that the parameter `cb` and `cb_ret` are mutually exclusive. 55 * 56 * Returns: an entry to be freed with qemu_del_vm_change_state_handler() 57 */ 58 VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev, 59 VMChangeStateHandler *cb, 60 VMChangeStateHandlerWithRet *cb_ret, 61 void *opaque) 62 { 63 assert(!cb || !cb_ret); 64 return qdev_add_vm_change_state_handler_full(dev, cb, NULL, cb_ret, opaque); 65 } 66 67 /* 68 * Exactly like qdev_add_vm_change_state_handler() but passes a prepare_cb 69 * and the cb_ret arguments too. 70 */ 71 VMChangeStateEntry *qdev_add_vm_change_state_handler_full( 72 DeviceState *dev, VMChangeStateHandler *cb, VMChangeStateHandler *prepare_cb, 73 VMChangeStateHandlerWithRet *cb_ret, void *opaque) 74 { 75 int depth = qdev_get_dev_tree_depth(dev); 76 77 assert(!cb || !cb_ret); 78 return qemu_add_vm_change_state_handler_prio_full(cb, prepare_cb, cb_ret, 79 opaque, depth); 80 } 81