xref: /openbmc/qemu/hw/watchdog/watchdog.c (revision 49ab747f)
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-common.h"
23 #include "qemu/option.h"
24 #include "qemu/config-file.h"
25 #include "qemu/queue.h"
26 #include "qapi/qmp/types.h"
27 #include "monitor/monitor.h"
28 #include "sysemu/sysemu.h"
29 #include "sysemu/watchdog.h"
30 
31 /* Possible values for action parameter. */
32 #define WDT_RESET        1	/* Hard reset. */
33 #define WDT_SHUTDOWN     2	/* Shutdown. */
34 #define WDT_POWEROFF     3	/* Quit. */
35 #define WDT_PAUSE        4	/* Pause. */
36 #define WDT_DEBUG        5	/* Prints a message and continues running. */
37 #define WDT_NONE         6	/* Do nothing. */
38 
39 static int watchdog_action = WDT_RESET;
40 static QLIST_HEAD(watchdog_list, WatchdogTimerModel) watchdog_list;
41 
42 void watchdog_add_model(WatchdogTimerModel *model)
43 {
44     QLIST_INSERT_HEAD(&watchdog_list, model, entry);
45 }
46 
47 /* Returns:
48  *   0 = continue
49  *   1 = exit program with error
50  *   2 = exit program without error
51  */
52 int select_watchdog(const char *p)
53 {
54     WatchdogTimerModel *model;
55     QemuOpts *opts;
56 
57     /* -watchdog ? lists available devices and exits cleanly. */
58     if (is_help_option(p)) {
59         QLIST_FOREACH(model, &watchdog_list, entry) {
60             fprintf(stderr, "\t%s\t%s\n",
61                      model->wdt_name, model->wdt_description);
62         }
63         return 2;
64     }
65 
66     QLIST_FOREACH(model, &watchdog_list, entry) {
67         if (strcasecmp(model->wdt_name, p) == 0) {
68             /* add the device */
69             opts = qemu_opts_create_nofail(qemu_find_opts("device"));
70             qemu_opt_set(opts, "driver", p);
71             return 0;
72         }
73     }
74 
75     fprintf(stderr, "Unknown -watchdog device. Supported devices are:\n");
76     QLIST_FOREACH(model, &watchdog_list, entry) {
77         fprintf(stderr, "\t%s\t%s\n",
78                  model->wdt_name, model->wdt_description);
79     }
80     return 1;
81 }
82 
83 int select_watchdog_action(const char *p)
84 {
85     if (strcasecmp(p, "reset") == 0)
86         watchdog_action = WDT_RESET;
87     else if (strcasecmp(p, "shutdown") == 0)
88         watchdog_action = WDT_SHUTDOWN;
89     else if (strcasecmp(p, "poweroff") == 0)
90         watchdog_action = WDT_POWEROFF;
91     else if (strcasecmp(p, "pause") == 0)
92         watchdog_action = WDT_PAUSE;
93     else if (strcasecmp(p, "debug") == 0)
94         watchdog_action = WDT_DEBUG;
95     else if (strcasecmp(p, "none") == 0)
96         watchdog_action = WDT_NONE;
97     else
98         return -1;
99 
100     return 0;
101 }
102 
103 static void watchdog_mon_event(const char *action)
104 {
105     QObject *data;
106 
107     data = qobject_from_jsonf("{ 'action': %s }", action);
108     monitor_protocol_event(QEVENT_WATCHDOG, data);
109     qobject_decref(data);
110 }
111 
112 /* This actually performs the "action" once a watchdog has expired,
113  * ie. reboot, shutdown, exit, etc.
114  */
115 void watchdog_perform_action(void)
116 {
117     switch(watchdog_action) {
118     case WDT_RESET:             /* same as 'system_reset' in monitor */
119         watchdog_mon_event("reset");
120         qemu_system_reset_request();
121         break;
122 
123     case WDT_SHUTDOWN:          /* same as 'system_powerdown' in monitor */
124         watchdog_mon_event("shutdown");
125         qemu_system_powerdown_request();
126         break;
127 
128     case WDT_POWEROFF:          /* same as 'quit' command in monitor */
129         watchdog_mon_event("poweroff");
130         exit(0);
131         break;
132 
133     case WDT_PAUSE:             /* same as 'stop' command in monitor */
134         watchdog_mon_event("pause");
135         vm_stop(RUN_STATE_WATCHDOG);
136         break;
137 
138     case WDT_DEBUG:
139         watchdog_mon_event("debug");
140         fprintf(stderr, "watchdog: timer fired\n");
141         break;
142 
143     case WDT_NONE:
144         watchdog_mon_event("none");
145         break;
146     }
147 }
148