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
qdev_get_dev_tree_depth(DeviceState * dev)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 */
qdev_add_vm_change_state_handler(DeviceState * dev,VMChangeStateHandler * cb,VMChangeStateHandlerWithRet * cb_ret,void * opaque)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 */
qdev_add_vm_change_state_handler_full(DeviceState * dev,VMChangeStateHandler * cb,VMChangeStateHandler * prepare_cb,VMChangeStateHandlerWithRet * cb_ret,void * opaque)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