xref: /qemu/hw/watchdog/watchdog.c (revision d072cdf3)
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 "sysemu/sysemu.h"
28 #include "sysemu/watchdog.h"
29 #include "qapi-event.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(qemu_find_opts("device"), NULL, 0,
70                                     &error_abort);
71             qemu_opt_set(opts, "driver", p);
72             return 0;
73         }
74     }
75 
76     fprintf(stderr, "Unknown -watchdog device. Supported devices are:\n");
77     QLIST_FOREACH(model, &watchdog_list, entry) {
78         fprintf(stderr, "\t%s\t%s\n",
79                  model->wdt_name, model->wdt_description);
80     }
81     return 1;
82 }
83 
84 int select_watchdog_action(const char *p)
85 {
86     if (strcasecmp(p, "reset") == 0)
87         watchdog_action = WDT_RESET;
88     else if (strcasecmp(p, "shutdown") == 0)
89         watchdog_action = WDT_SHUTDOWN;
90     else if (strcasecmp(p, "poweroff") == 0)
91         watchdog_action = WDT_POWEROFF;
92     else if (strcasecmp(p, "pause") == 0)
93         watchdog_action = WDT_PAUSE;
94     else if (strcasecmp(p, "debug") == 0)
95         watchdog_action = WDT_DEBUG;
96     else if (strcasecmp(p, "none") == 0)
97         watchdog_action = WDT_NONE;
98     else
99         return -1;
100 
101     return 0;
102 }
103 
104 /* This actually performs the "action" once a watchdog has expired,
105  * ie. reboot, shutdown, exit, etc.
106  */
107 void watchdog_perform_action(void)
108 {
109     switch (watchdog_action) {
110     case WDT_RESET:             /* same as 'system_reset' in monitor */
111         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_RESET, &error_abort);
112         qemu_system_reset_request();
113         break;
114 
115     case WDT_SHUTDOWN:          /* same as 'system_powerdown' in monitor */
116         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_SHUTDOWN, &error_abort);
117         qemu_system_powerdown_request();
118         break;
119 
120     case WDT_POWEROFF:          /* same as 'quit' command in monitor */
121         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_POWEROFF, &error_abort);
122         exit(0);
123 
124     case WDT_PAUSE:             /* same as 'stop' command in monitor */
125         /* In a timer callback, when vm_stop calls qemu_clock_enable
126          * you would get a deadlock.  Bypass the problem.
127          */
128         qemu_system_vmstop_request_prepare();
129         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_PAUSE, &error_abort);
130         qemu_system_vmstop_request(RUN_STATE_WATCHDOG);
131         break;
132 
133     case WDT_DEBUG:
134         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_DEBUG, &error_abort);
135         fprintf(stderr, "watchdog: timer fired\n");
136         break;
137 
138     case WDT_NONE:
139         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_NONE, &error_abort);
140         break;
141     }
142 }
143