xref: /openbmc/qemu/hw/watchdog/watchdog.c (revision 42f7a448)
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 #include "hw/nmi.h"
31 
32 static int watchdog_action = WDT_RESET;
33 static QLIST_HEAD(watchdog_list, WatchdogTimerModel) watchdog_list;
34 
35 void watchdog_add_model(WatchdogTimerModel *model)
36 {
37     QLIST_INSERT_HEAD(&watchdog_list, model, entry);
38 }
39 
40 /* Returns:
41  *   0 = continue
42  *   1 = exit program with error
43  *   2 = exit program without error
44  */
45 int select_watchdog(const char *p)
46 {
47     WatchdogTimerModel *model;
48     QemuOpts *opts;
49 
50     /* -watchdog ? lists available devices and exits cleanly. */
51     if (is_help_option(p)) {
52         QLIST_FOREACH(model, &watchdog_list, entry) {
53             fprintf(stderr, "\t%s\t%s\n",
54                      model->wdt_name, model->wdt_description);
55         }
56         return 2;
57     }
58 
59     QLIST_FOREACH(model, &watchdog_list, entry) {
60         if (strcasecmp(model->wdt_name, p) == 0) {
61             /* add the device */
62             opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
63                                     &error_abort);
64             qemu_opt_set(opts, "driver", p, &error_abort);
65             return 0;
66         }
67     }
68 
69     fprintf(stderr, "Unknown -watchdog device. Supported devices are:\n");
70     QLIST_FOREACH(model, &watchdog_list, entry) {
71         fprintf(stderr, "\t%s\t%s\n",
72                  model->wdt_name, model->wdt_description);
73     }
74     return 1;
75 }
76 
77 int select_watchdog_action(const char *p)
78 {
79     if (strcasecmp(p, "reset") == 0)
80         watchdog_action = WDT_RESET;
81     else if (strcasecmp(p, "shutdown") == 0)
82         watchdog_action = WDT_SHUTDOWN;
83     else if (strcasecmp(p, "poweroff") == 0)
84         watchdog_action = WDT_POWEROFF;
85     else if (strcasecmp(p, "pause") == 0)
86         watchdog_action = WDT_PAUSE;
87     else if (strcasecmp(p, "debug") == 0)
88         watchdog_action = WDT_DEBUG;
89     else if (strcasecmp(p, "none") == 0)
90         watchdog_action = WDT_NONE;
91     else if (strcasecmp(p, "inject-nmi") == 0)
92         watchdog_action = WDT_NMI;
93     else
94         return -1;
95 
96     return 0;
97 }
98 
99 int get_watchdog_action(void)
100 {
101     return watchdog_action;
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     case WDT_NMI:
143         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_INJECT_NMI,
144                                  &error_abort);
145         inject_nmi();
146         break;
147     }
148 }
149