xref: /openbmc/qemu/hw/watchdog/watchdog.c (revision d695918f)
1 /*
2  * Virtual hardware watchdog.
3  *
4  * Copyright (C) 2009 Red Hat Inc.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  *
19  * By Richard W.M. Jones (rjones@redhat.com).
20  */
21 
22 #include "qemu/osdep.h"
23 #include "qemu/option.h"
24 #include "qemu/config-file.h"
25 #include "qemu/queue.h"
26 #include "qapi/error.h"
27 #include "qapi/qapi-commands-run-state.h"
28 #include "qapi/qapi-events-run-state.h"
29 #include "sysemu/runstate.h"
30 #include "sysemu/watchdog.h"
31 #include "hw/nmi.h"
32 #include "qemu/help_option.h"
33 
34 static WatchdogAction watchdog_action = WATCHDOG_ACTION_RESET;
35 static QLIST_HEAD(, WatchdogTimerModel) watchdog_list;
36 
37 void watchdog_add_model(WatchdogTimerModel *model)
38 {
39     QLIST_INSERT_HEAD(&watchdog_list, model, entry);
40 }
41 
42 /* Returns:
43  *   0 = continue
44  *   1 = exit program with error
45  *   2 = exit program without error
46  */
47 int select_watchdog(const char *p)
48 {
49     WatchdogTimerModel *model;
50     QemuOpts *opts;
51 
52     /* -watchdog ? lists available devices and exits cleanly. */
53     if (is_help_option(p)) {
54         QLIST_FOREACH(model, &watchdog_list, entry) {
55             fprintf(stderr, "\t%s\t%s\n",
56                      model->wdt_name, model->wdt_description);
57         }
58         return 2;
59     }
60 
61     QLIST_FOREACH(model, &watchdog_list, entry) {
62         if (strcasecmp(model->wdt_name, p) == 0) {
63             /* add the device */
64             opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
65                                     &error_abort);
66             qemu_opt_set(opts, "driver", p, &error_abort);
67             return 0;
68         }
69     }
70 
71     fprintf(stderr, "Unknown -watchdog device. Supported devices are:\n");
72     QLIST_FOREACH(model, &watchdog_list, entry) {
73         fprintf(stderr, "\t%s\t%s\n",
74                  model->wdt_name, model->wdt_description);
75     }
76     return 1;
77 }
78 
79 WatchdogAction get_watchdog_action(void)
80 {
81     return watchdog_action;
82 }
83 
84 /* This actually performs the "action" once a watchdog has expired,
85  * ie. reboot, shutdown, exit, etc.
86  */
87 void watchdog_perform_action(void)
88 {
89     switch (watchdog_action) {
90     case WATCHDOG_ACTION_RESET:     /* same as 'system_reset' in monitor */
91         qapi_event_send_watchdog(WATCHDOG_ACTION_RESET);
92         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
93         break;
94 
95     case WATCHDOG_ACTION_SHUTDOWN:  /* same as 'system_powerdown' in monitor */
96         qapi_event_send_watchdog(WATCHDOG_ACTION_SHUTDOWN);
97         qemu_system_powerdown_request();
98         break;
99 
100     case WATCHDOG_ACTION_POWEROFF:  /* same as 'quit' command in monitor */
101         qapi_event_send_watchdog(WATCHDOG_ACTION_POWEROFF);
102         exit(0);
103 
104     case WATCHDOG_ACTION_PAUSE:     /* same as 'stop' command in monitor */
105         /* In a timer callback, when vm_stop calls qemu_clock_enable
106          * you would get a deadlock.  Bypass the problem.
107          */
108         qemu_system_vmstop_request_prepare();
109         qapi_event_send_watchdog(WATCHDOG_ACTION_PAUSE);
110         qemu_system_vmstop_request(RUN_STATE_WATCHDOG);
111         break;
112 
113     case WATCHDOG_ACTION_DEBUG:
114         qapi_event_send_watchdog(WATCHDOG_ACTION_DEBUG);
115         fprintf(stderr, "watchdog: timer fired\n");
116         break;
117 
118     case WATCHDOG_ACTION_NONE:
119         qapi_event_send_watchdog(WATCHDOG_ACTION_NONE);
120         break;
121 
122     case WATCHDOG_ACTION_INJECT_NMI:
123         qapi_event_send_watchdog(WATCHDOG_ACTION_INJECT_NMI);
124         nmi_monitor_handle(0, NULL);
125         break;
126 
127     default:
128         assert(0);
129     }
130 }
131 
132 void qmp_watchdog_set_action(WatchdogAction action, Error **errp)
133 {
134     watchdog_action = action;
135 }
136