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Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -07001/*
2 * Handle extern requests for shutdown, reboot and sysrq
3 */
Joe Perches283c0972013-06-28 03:21:41 -07004
5#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
6
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -07007#include <linux/kernel.h>
8#include <linux/err.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/slab.h>
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -070010#include <linux/reboot.h>
11#include <linux/sysrq.h>
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010012#include <linux/stop_machine.h>
13#include <linux/freezer.h>
Rafael J. Wysocki19234c02011-04-20 00:36:11 +020014#include <linux/syscore_ops.h>
Paul Gortmaker63c97442011-07-10 13:22:07 -040015#include <linux/export.h>
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -070016
Stefano Stabellini016b6f52010-05-14 12:45:07 +010017#include <xen/xen.h>
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -070018#include <xen/xenbus.h>
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010019#include <xen/grant_table.h>
20#include <xen/events.h>
21#include <xen/hvc-console.h>
Julien Gralla9fd60e2015-06-17 15:28:02 +010022#include <xen/page.h>
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010023#include <xen/xen-ops.h>
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -070024
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010025#include <asm/xen/hypercall.h>
Stefano Stabellini016b6f52010-05-14 12:45:07 +010026#include <asm/xen/hypervisor.h>
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010027
28enum shutdown_state {
29 SHUTDOWN_INVALID = -1,
30 SHUTDOWN_POWEROFF = 0,
31 SHUTDOWN_SUSPEND = 2,
32 /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only
33 report a crash, not be instructed to crash!
34 HALT is the same as POWEROFF, as far as we're concerned. The tools use
35 the distinction when we return the reason code to them. */
36 SHUTDOWN_HALT = 4,
37};
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -070038
39/* Ignore multiple shutdown requests. */
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010040static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
41
Ian Campbellceb18022011-02-17 11:04:20 +000042struct suspend_info {
43 int cancelled;
44};
45
Stanislaw Gruszkacd979882014-02-26 11:30:30 +010046static RAW_NOTIFIER_HEAD(xen_resume_notifier);
47
48void xen_resume_notifier_register(struct notifier_block *nb)
49{
50 raw_notifier_chain_register(&xen_resume_notifier, nb);
51}
52EXPORT_SYMBOL_GPL(xen_resume_notifier_register);
53
54void xen_resume_notifier_unregister(struct notifier_block *nb)
55{
56 raw_notifier_chain_unregister(&xen_resume_notifier, nb);
57}
58EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister);
59
Stefano Stabellini65e053a2013-06-27 14:28:38 +010060#ifdef CONFIG_HIBERNATE_CALLBACKS
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010061static int xen_suspend(void *data)
62{
Ian Campbellceb18022011-02-17 11:04:20 +000063 struct suspend_info *si = data;
Jeremy Fitzhardinge359cdd32008-05-26 23:31:28 +010064 int err;
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010065
66 BUG_ON(!irqs_disabled());
67
Rafael J. Wysocki2e711c02011-04-26 19:15:07 +020068 err = syscore_suspend();
Rafael J. Wysocki770824b2009-02-22 18:38:50 +010069 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -070070 pr_err("%s: system core suspend failed: %d\n", __func__, err);
Rafael J. Wysocki770824b2009-02-22 18:38:50 +010071 return err;
72 }
Jeremy Fitzhardinge359cdd32008-05-26 23:31:28 +010073
David Vrabelaa8532c2014-05-08 11:09:23 +010074 gnttab_suspend();
75 xen_arch_pre_suspend();
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010076
77 /*
78 * This hypercall returns 1 if suspend was cancelled
79 * or the domain was merely checkpointed, and 0 if it
80 * is resuming in a new domain.
81 */
David Vrabelaa8532c2014-05-08 11:09:23 +010082 si->cancelled = HYPERVISOR_suspend(xen_pv_domain()
Julien Grall0df4f262015-08-07 17:34:37 +010083 ? virt_to_gfn(xen_start_info)
David Vrabelaa8532c2014-05-08 11:09:23 +010084 : 0);
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010085
David Vrabelaa8532c2014-05-08 11:09:23 +010086 xen_arch_post_suspend(si->cancelled);
87 gnttab_resume();
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010088
Ian Campbellceb18022011-02-17 11:04:20 +000089 if (!si->cancelled) {
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010090 xen_irq_resume();
Isaku Yamahataad55db92008-07-08 15:06:32 -070091 xen_timer_resume();
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010092 }
93
Rafael J. Wysocki19234c02011-04-20 00:36:11 +020094 syscore_resume();
Ian Campbell1e6fcf82009-03-25 17:46:42 +000095
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +010096 return 0;
97}
98
99static void do_suspend(void)
100{
101 int err;
Ian Campbellceb18022011-02-17 11:04:20 +0000102 struct suspend_info si;
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100103
104 shutting_down = SHUTDOWN_SUSPEND;
105
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100106 err = freeze_processes();
107 if (err) {
Ross Lagerwall72978b22015-01-19 13:19:38 +0000108 pr_err("%s: freeze processes failed %d\n", __func__, err);
Tejun Heo3fc1f1e2010-05-06 18:49:20 +0200109 goto out;
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100110 }
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100111
Ross Lagerwall72978b22015-01-19 13:19:38 +0000112 err = freeze_kernel_threads();
113 if (err) {
114 pr_err("%s: freeze kernel threads failed %d\n", __func__, err);
115 goto out_thaw;
116 }
117
Shriram Rajagopalanb3e96c02011-02-22 14:59:06 -0800118 err = dpm_suspend_start(PMSG_FREEZE);
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100119 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -0700120 pr_err("%s: dpm_suspend_start %d\n", __func__, err);
Ian Campbell65f63382009-12-01 11:47:14 +0000121 goto out_thaw;
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100122 }
123
Ian Campbellc5cae662009-12-17 13:57:09 +0000124 printk(KERN_DEBUG "suspending xenstore...\n");
125 xs_suspend();
126
Rafael J. Wysockicf579df2012-01-29 20:38:29 +0100127 err = dpm_suspend_end(PMSG_FREEZE);
Rafael J. Wysocki2ed8d2b32009-03-16 22:34:06 +0100128 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -0700129 pr_err("dpm_suspend_end failed: %d\n", err);
Konrad Rzeszutek Wilk186bab12012-04-17 14:35:49 -0400130 si.cancelled = 0;
Ian Campbell65f63382009-12-01 11:47:14 +0000131 goto out_resume;
Rafael J. Wysocki2ed8d2b32009-03-16 22:34:06 +0100132 }
133
Boris Ostrovsky2b953a52015-04-28 18:46:20 -0400134 xen_arch_suspend();
135
Ian Campbellceb18022011-02-17 11:04:20 +0000136 si.cancelled = 1;
137
Ian Campbellb056b6a2011-02-17 11:04:20 +0000138 err = stop_machine(xen_suspend, &si, cpumask_of(0));
Jeremy Fitzhardinge922cc38a2009-11-24 09:58:49 -0800139
David Vrabel1b647822014-07-02 17:25:23 +0100140 /* Resume console as early as possible. */
141 if (!si.cancelled)
142 xen_console_resume();
143
Stanislaw Gruszkacd979882014-02-26 11:30:30 +0100144 raw_notifier_call_chain(&xen_resume_notifier, 0, NULL);
145
Rafael J. Wysockicf579df2012-01-29 20:38:29 +0100146 dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
Jeremy Fitzhardinge922cc38a2009-11-24 09:58:49 -0800147
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100148 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -0700149 pr_err("failed to start xen_suspend: %d\n", err);
Ian Campbellceb18022011-02-17 11:04:20 +0000150 si.cancelled = 1;
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100151 }
152
Boris Ostrovsky2b953a52015-04-28 18:46:20 -0400153 xen_arch_resume();
154
Ian Campbellc5cae662009-12-17 13:57:09 +0000155out_resume:
Boris Ostrovsky2b953a52015-04-28 18:46:20 -0400156 if (!si.cancelled)
Ian Campbellde5b31b2009-02-09 12:05:50 -0800157 xs_resume();
Boris Ostrovsky2b953a52015-04-28 18:46:20 -0400158 else
Ian Campbellde5b31b2009-02-09 12:05:50 -0800159 xs_suspend_cancel();
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100160
Shriram Rajagopalanb3e96c02011-02-22 14:59:06 -0800161 dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100162
Ian Campbell65f63382009-12-01 11:47:14 +0000163out_thaw:
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100164 thaw_processes();
Ian Campbell65f63382009-12-01 11:47:14 +0000165out:
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100166 shutting_down = SHUTDOWN_INVALID;
167}
Rafael J. Wysocki1f112ce2011-04-11 22:54:42 +0200168#endif /* CONFIG_HIBERNATE_CALLBACKS */
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700169
Ian Campbell55271722011-02-17 11:04:20 +0000170struct shutdown_handler {
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200171#define SHUTDOWN_CMD_SIZE 11
172 const char command[SHUTDOWN_CMD_SIZE];
173 bool flag;
Ian Campbell55271722011-02-17 11:04:20 +0000174 void (*cb)(void);
175};
176
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400177static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unused)
178{
179 switch (code) {
180 case SYS_DOWN:
181 case SYS_HALT:
182 case SYS_POWER_OFF:
183 shutting_down = SHUTDOWN_POWEROFF;
184 default:
185 break;
186 }
187 return NOTIFY_DONE;
188}
Ian Campbell55271722011-02-17 11:04:20 +0000189static void do_poweroff(void)
190{
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400191 switch (system_state) {
192 case SYSTEM_BOOTING:
193 orderly_poweroff(true);
194 break;
195 case SYSTEM_RUNNING:
196 orderly_poweroff(false);
197 break;
198 default:
199 /* Don't do it when we are halting/rebooting. */
200 pr_info("Ignoring Xen toolstack shutdown.\n");
201 break;
202 }
Ian Campbell55271722011-02-17 11:04:20 +0000203}
204
205static void do_reboot(void)
206{
207 shutting_down = SHUTDOWN_POWEROFF; /* ? */
208 ctrl_alt_del();
209}
210
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200211static struct shutdown_handler shutdown_handlers[] = {
212 { "poweroff", true, do_poweroff },
213 { "halt", false, do_poweroff },
214 { "reboot", true, do_reboot },
215#ifdef CONFIG_HIBERNATE_CALLBACKS
216 { "suspend", true, do_suspend },
217#endif
218};
219
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700220static void shutdown_handler(struct xenbus_watch *watch,
Juergen Gross5584ea22017-02-09 14:39:57 +0100221 const char *path, const char *token)
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700222{
223 char *str;
224 struct xenbus_transaction xbt;
225 int err;
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200226 int idx;
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700227
228 if (shutting_down != SHUTDOWN_INVALID)
229 return;
230
231 again:
232 err = xenbus_transaction_start(&xbt);
233 if (err)
234 return;
235
236 str = (char *)xenbus_read(xbt, "control", "shutdown", NULL);
237 /* Ignore read errors and empty reads. */
238 if (XENBUS_IS_ERR_READ(str)) {
239 xenbus_transaction_end(xbt, 1);
240 return;
241 }
242
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200243 for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) {
244 if (strcmp(str, shutdown_handlers[idx].command) == 0)
Ian Campbell55271722011-02-17 11:04:20 +0000245 break;
246 }
247
248 /* Only acknowledge commands which we are prepared to handle. */
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200249 if (idx < ARRAY_SIZE(shutdown_handlers))
Ian Campbell55271722011-02-17 11:04:20 +0000250 xenbus_write(xbt, "control", "shutdown", "");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700251
252 err = xenbus_transaction_end(xbt, 0);
253 if (err == -EAGAIN) {
254 kfree(str);
255 goto again;
256 }
257
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200258 if (idx < ARRAY_SIZE(shutdown_handlers)) {
259 shutdown_handlers[idx].cb();
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100260 } else {
Joe Perches283c0972013-06-28 03:21:41 -0700261 pr_info("Ignoring shutdown request: %s\n", str);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700262 shutting_down = SHUTDOWN_INVALID;
263 }
264
265 kfree(str);
266}
267
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700268#ifdef CONFIG_MAGIC_SYSRQ
Juergen Gross5584ea22017-02-09 14:39:57 +0100269static void sysrq_handler(struct xenbus_watch *watch, const char *path,
270 const char *token)
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700271{
272 char sysrq_key = '\0';
273 struct xenbus_transaction xbt;
274 int err;
275
276 again:
277 err = xenbus_transaction_start(&xbt);
278 if (err)
279 return;
Jan Beulich4fed1b12017-02-03 01:54:05 -0700280 if (xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key) < 0) {
Joe Perches283c0972013-06-28 03:21:41 -0700281 pr_err("Unable to read sysrq code in control/sysrq\n");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700282 xenbus_transaction_end(xbt, 1);
283 return;
284 }
285
286 if (sysrq_key != '\0')
287 xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
288
289 err = xenbus_transaction_end(xbt, 0);
290 if (err == -EAGAIN)
291 goto again;
292
293 if (sysrq_key != '\0')
Dmitry Torokhovf3353972010-08-17 21:15:47 -0700294 handle_sysrq(sysrq_key);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700295}
296
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700297static struct xenbus_watch sysrq_watch = {
298 .node = "control/sysrq",
299 .callback = sysrq_handler
300};
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700301#endif
302
303static struct xenbus_watch shutdown_watch = {
304 .node = "control/shutdown",
305 .callback = shutdown_handler
306};
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700307
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400308static struct notifier_block xen_reboot_nb = {
309 .notifier_call = poweroff_nb,
310};
311
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700312static int setup_shutdown_watcher(void)
313{
314 int err;
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200315 int idx;
316#define FEATURE_PATH_SIZE (SHUTDOWN_CMD_SIZE + sizeof("feature-"))
317 char node[FEATURE_PATH_SIZE];
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700318
319 err = register_xenbus_watch(&shutdown_watch);
320 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -0700321 pr_err("Failed to set shutdown watcher\n");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700322 return err;
323 }
324
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400325
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700326#ifdef CONFIG_MAGIC_SYSRQ
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700327 err = register_xenbus_watch(&sysrq_watch);
328 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -0700329 pr_err("Failed to set sysrq watcher\n");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700330 return err;
331 }
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700332#endif
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700333
Juergen Gross44b3c7a2016-10-11 13:34:16 +0200334 for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) {
335 if (!shutdown_handlers[idx].flag)
336 continue;
337 snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
338 shutdown_handlers[idx].command);
339 xenbus_printf(XBT_NIL, "control", node, "%u", 1);
340 }
341
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700342 return 0;
343}
344
345static int shutdown_event(struct notifier_block *notifier,
346 unsigned long event,
347 void *data)
348{
349 setup_shutdown_watcher();
350 return NOTIFY_DONE;
351}
352
Stefano Stabellini016b6f52010-05-14 12:45:07 +0100353int xen_setup_shutdown_event(void)
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700354{
355 static struct notifier_block xenstore_notifier = {
356 .notifier_call = shutdown_event
357 };
Stefano Stabellini702d4eb92010-12-02 17:54:50 +0000358
359 if (!xen_domain())
360 return -ENODEV;
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700361 register_xenstore_notifier(&xenstore_notifier);
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400362 register_reboot_notifier(&xen_reboot_nb);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700363
364 return 0;
365}
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100366EXPORT_SYMBOL_GPL(xen_setup_shutdown_event);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700367
Stefano Stabellini702d4eb92010-12-02 17:54:50 +0000368subsys_initcall(xen_setup_shutdown_event);