meson: convert hw/vfio
[qemu.git] / hw / core / vm-change-state-handler.c
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 }