hw/watchdog/watchdog.c

   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 /* Possible values for action parameter. */
  33 #define WDT_RESET        1      /* Hard reset. */
  34 #define WDT_SHUTDOWN     2      /* Shutdown. */
  35 #define WDT_POWEROFF     3      /* Quit. */
  36 #define WDT_PAUSE        4      /* Pause. */
  37 #define WDT_DEBUG        5      /* Prints a message and continues running. */
  38 #define WDT_NONE         6      /* Do nothing. */
  39 #define WDT_NMI          7      /* Inject nmi into the guest */
  40
  41 static int watchdog_action = WDT_RESET;
  42 static QLIST_HEAD(watchdog_list, WatchdogTimerModel) watchdog_list;
  43
  44 void watchdog_add_model(WatchdogTimerModel *model)
  45 {
  46     QLIST_INSERT_HEAD(&watchdog_list, model, entry);
  47 }
  48
  49 /* Returns:
  50  *   0 = continue
  51  *   1 = exit program with error
  52  *   2 = exit program without error
  53  */
  54 int select_watchdog(const char *p)
  55 {
  56     WatchdogTimerModel *model;
  57     QemuOpts *opts;
  58
  59     /* -watchdog ? lists available devices and exits cleanly. */
  60     if (is_help_option(p)) {
  61         QLIST_FOREACH(model, &watchdog_list, entry) {
  62             fprintf(stderr, "\t%s\t%s\n",
  63                      model->wdt_name, model->wdt_description);
  64         }
  65         return 2;
  66     }
  67
  68     QLIST_FOREACH(model, &watchdog_list, entry) {
  69         if (strcasecmp(model->wdt_name, p) == 0) {
  70             /* add the device */
  71             opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
  72                                     &error_abort);
  73             qemu_opt_set(opts, "driver", p, &error_abort);
  74             return 0;
  75         }
  76     }
  77
  78     fprintf(stderr, "Unknown -watchdog device. Supported devices are:\n");
  79     QLIST_FOREACH(model, &watchdog_list, entry) {
  80         fprintf(stderr, "\t%s\t%s\n",
  81                  model->wdt_name, model->wdt_description);
  82     }
  83     return 1;
  84 }
  85
  86 int select_watchdog_action(const char *p)
  87 {
  88     if (strcasecmp(p, "reset") == 0)
  89         watchdog_action = WDT_RESET;
  90     else if (strcasecmp(p, "shutdown") == 0)
  91         watchdog_action = WDT_SHUTDOWN;
  92     else if (strcasecmp(p, "poweroff") == 0)
  93         watchdog_action = WDT_POWEROFF;
  94     else if (strcasecmp(p, "pause") == 0)
  95         watchdog_action = WDT_PAUSE;
  96     else if (strcasecmp(p, "debug") == 0)
  97         watchdog_action = WDT_DEBUG;
  98     else if (strcasecmp(p, "none") == 0)
  99         watchdog_action = WDT_NONE;
 100     else if (strcasecmp(p, "inject-nmi") == 0)
 101         watchdog_action = WDT_NMI;
 102     else
 103         return -1;
 104
 105     return 0;
 106 }
 107
 108 /* This actually performs the "action" once a watchdog has expired,
 109  * ie. reboot, shutdown, exit, etc.
 110  */
 111 void watchdog_perform_action(void)
 112 {
 113     switch (watchdog_action) {
 114     case WDT_RESET:             /* same as 'system_reset' in monitor */
 115         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_RESET, &error_abort);
 116         qemu_system_reset_request();
 117         break;
 118
 119     case WDT_SHUTDOWN:          /* same as 'system_powerdown' in monitor */
 120         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_SHUTDOWN, &error_abort);
 121         qemu_system_powerdown_request();
 122         break;
 123
 124     case WDT_POWEROFF:          /* same as 'quit' command in monitor */
 125         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_POWEROFF, &error_abort);
 126         exit(0);
 127
 128     case WDT_PAUSE:             /* same as 'stop' command in monitor */
 129         /* In a timer callback, when vm_stop calls qemu_clock_enable
 130          * you would get a deadlock.  Bypass the problem.
 131          */
 132         qemu_system_vmstop_request_prepare();
 133         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_PAUSE, &error_abort);
 134         qemu_system_vmstop_request(RUN_STATE_WATCHDOG);
 135         break;
 136
 137     case WDT_DEBUG:
 138         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_DEBUG, &error_abort);
 139         fprintf(stderr, "watchdog: timer fired\n");
 140         break;
 141
 142     case WDT_NONE:
 143         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_NONE, &error_abort);
 144         break;
 145
 146     case WDT_NMI:
 147         qapi_event_send_watchdog(WATCHDOG_EXPIRATION_ACTION_INJECT_NMI,
 148                                  &error_abort);
 149         inject_nmi();
 150         break;
 151     }
 152 }