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
  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, &error_abort);
  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 }