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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. Wysocki2ed8d2b2009-03-16 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. Wysocki2ed8d2b2009-03-16 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 {
171 const char *command;
172 void (*cb)(void);
173};
174
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400175static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unused)
176{
177 switch (code) {
178 case SYS_DOWN:
179 case SYS_HALT:
180 case SYS_POWER_OFF:
181 shutting_down = SHUTDOWN_POWEROFF;
182 default:
183 break;
184 }
185 return NOTIFY_DONE;
186}
Ian Campbell55271722011-02-17 11:04:20 +0000187static void do_poweroff(void)
188{
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400189 switch (system_state) {
190 case SYSTEM_BOOTING:
191 orderly_poweroff(true);
192 break;
193 case SYSTEM_RUNNING:
194 orderly_poweroff(false);
195 break;
196 default:
197 /* Don't do it when we are halting/rebooting. */
198 pr_info("Ignoring Xen toolstack shutdown.\n");
199 break;
200 }
Ian Campbell55271722011-02-17 11:04:20 +0000201}
202
203static void do_reboot(void)
204{
205 shutting_down = SHUTDOWN_POWEROFF; /* ? */
206 ctrl_alt_del();
207}
208
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700209static void shutdown_handler(struct xenbus_watch *watch,
210 const char **vec, unsigned int len)
211{
212 char *str;
213 struct xenbus_transaction xbt;
214 int err;
Ian Campbell55271722011-02-17 11:04:20 +0000215 static struct shutdown_handler handlers[] = {
216 { "poweroff", do_poweroff },
217 { "halt", do_poweroff },
218 { "reboot", do_reboot },
Rafael J. Wysocki1f112ce2011-04-11 22:54:42 +0200219#ifdef CONFIG_HIBERNATE_CALLBACKS
Ian Campbell55271722011-02-17 11:04:20 +0000220 { "suspend", do_suspend },
221#endif
222 {NULL, NULL},
223 };
224 static struct shutdown_handler *handler;
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700225
226 if (shutting_down != SHUTDOWN_INVALID)
227 return;
228
229 again:
230 err = xenbus_transaction_start(&xbt);
231 if (err)
232 return;
233
234 str = (char *)xenbus_read(xbt, "control", "shutdown", NULL);
235 /* Ignore read errors and empty reads. */
236 if (XENBUS_IS_ERR_READ(str)) {
237 xenbus_transaction_end(xbt, 1);
238 return;
239 }
240
Ian Campbell55271722011-02-17 11:04:20 +0000241 for (handler = &handlers[0]; handler->command; handler++) {
242 if (strcmp(str, handler->command) == 0)
243 break;
244 }
245
246 /* Only acknowledge commands which we are prepared to handle. */
247 if (handler->cb)
248 xenbus_write(xbt, "control", "shutdown", "");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700249
250 err = xenbus_transaction_end(xbt, 0);
251 if (err == -EAGAIN) {
252 kfree(str);
253 goto again;
254 }
255
Ian Campbell55271722011-02-17 11:04:20 +0000256 if (handler->cb) {
257 handler->cb();
Jeremy Fitzhardinge0e913982008-05-26 23:31:27 +0100258 } else {
Joe Perches283c0972013-06-28 03:21:41 -0700259 pr_info("Ignoring shutdown request: %s\n", str);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700260 shutting_down = SHUTDOWN_INVALID;
261 }
262
263 kfree(str);
264}
265
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700266#ifdef CONFIG_MAGIC_SYSRQ
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700267static void sysrq_handler(struct xenbus_watch *watch, const char **vec,
268 unsigned int len)
269{
270 char sysrq_key = '\0';
271 struct xenbus_transaction xbt;
272 int err;
273
274 again:
275 err = xenbus_transaction_start(&xbt);
276 if (err)
277 return;
278 if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) {
Joe Perches283c0972013-06-28 03:21:41 -0700279 pr_err("Unable to read sysrq code in control/sysrq\n");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700280 xenbus_transaction_end(xbt, 1);
281 return;
282 }
283
284 if (sysrq_key != '\0')
285 xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
286
287 err = xenbus_transaction_end(xbt, 0);
288 if (err == -EAGAIN)
289 goto again;
290
291 if (sysrq_key != '\0')
Dmitry Torokhovf3353972010-08-17 21:15:47 -0700292 handle_sysrq(sysrq_key);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700293}
294
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700295static struct xenbus_watch sysrq_watch = {
296 .node = "control/sysrq",
297 .callback = sysrq_handler
298};
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700299#endif
300
301static struct xenbus_watch shutdown_watch = {
302 .node = "control/shutdown",
303 .callback = shutdown_handler
304};
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700305
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400306static struct notifier_block xen_reboot_nb = {
307 .notifier_call = poweroff_nb,
308};
309
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700310static int setup_shutdown_watcher(void)
311{
312 int err;
313
314 err = register_xenbus_watch(&shutdown_watch);
315 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -0700316 pr_err("Failed to set shutdown watcher\n");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700317 return err;
318 }
319
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400320
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700321#ifdef CONFIG_MAGIC_SYSRQ
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700322 err = register_xenbus_watch(&sysrq_watch);
323 if (err) {
Joe Perches283c0972013-06-28 03:21:41 -0700324 pr_err("Failed to set sysrq watcher\n");
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700325 return err;
326 }
Randy Dunlapf3bc3182010-05-24 14:33:41 -0700327#endif
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700328
329 return 0;
330}
331
332static int shutdown_event(struct notifier_block *notifier,
333 unsigned long event,
334 void *data)
335{
336 setup_shutdown_watcher();
337 return NOTIFY_DONE;
338}
339
Stefano Stabellini016b6f52010-05-14 12:45:07 +0100340int xen_setup_shutdown_event(void)
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700341{
342 static struct notifier_block xenstore_notifier = {
343 .notifier_call = shutdown_event
344 };
Stefano Stabellini702d4eb92010-12-02 17:54:50 +0000345
346 if (!xen_domain())
347 return -ENODEV;
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700348 register_xenstore_notifier(&xenstore_notifier);
Konrad Rzeszutek Wilkeb47f712014-04-04 14:53:41 -0400349 register_reboot_notifier(&xen_reboot_nb);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700350
351 return 0;
352}
Stefano Stabellini183d03c2010-05-17 17:08:21 +0100353EXPORT_SYMBOL_GPL(xen_setup_shutdown_event);
Jeremy Fitzhardinge3e2b8fb2007-07-17 18:37:07 -0700354
Stefano Stabellini702d4eb92010-12-02 17:54:50 +0000355subsys_initcall(xen_setup_shutdown_event);