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 | } |
63 | |