Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3e2b8fbe JF |
2 | /* |
3 | * Handle extern requests for shutdown, reboot and sysrq | |
4 | */ | |
283c0972 JP |
5 | |
6 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt | |
7 | ||
3e2b8fbe JF |
8 | #include <linux/kernel.h> |
9 | #include <linux/err.h> | |
5a0e3ad6 | 10 | #include <linux/slab.h> |
3e2b8fbe JF |
11 | #include <linux/reboot.h> |
12 | #include <linux/sysrq.h> | |
0e91398f JF |
13 | #include <linux/stop_machine.h> |
14 | #include <linux/freezer.h> | |
19234c08 | 15 | #include <linux/syscore_ops.h> |
63c9744b | 16 | #include <linux/export.h> |
3e2b8fbe | 17 | |
016b6f5f | 18 | #include <xen/xen.h> |
3e2b8fbe | 19 | #include <xen/xenbus.h> |
0e91398f JF |
20 | #include <xen/grant_table.h> |
21 | #include <xen/events.h> | |
22 | #include <xen/hvc-console.h> | |
a9fd60e2 | 23 | #include <xen/page.h> |
0e91398f | 24 | #include <xen/xen-ops.h> |
3e2b8fbe | 25 | |
0e91398f | 26 | #include <asm/xen/hypercall.h> |
016b6f5f | 27 | #include <asm/xen/hypervisor.h> |
0e91398f JF |
28 | |
29 | enum shutdown_state { | |
30 | SHUTDOWN_INVALID = -1, | |
31 | SHUTDOWN_POWEROFF = 0, | |
32 | SHUTDOWN_SUSPEND = 2, | |
33 | /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only | |
34 | report a crash, not be instructed to crash! | |
35 | HALT is the same as POWEROFF, as far as we're concerned. The tools use | |
36 | the distinction when we return the reason code to them. */ | |
37 | SHUTDOWN_HALT = 4, | |
38 | }; | |
3e2b8fbe JF |
39 | |
40 | /* Ignore multiple shutdown requests. */ | |
0e91398f JF |
41 | static enum shutdown_state shutting_down = SHUTDOWN_INVALID; |
42 | ||
ceb18029 IC |
43 | struct suspend_info { |
44 | int cancelled; | |
45 | }; | |
46 | ||
cd979883 SG |
47 | static RAW_NOTIFIER_HEAD(xen_resume_notifier); |
48 | ||
49 | void xen_resume_notifier_register(struct notifier_block *nb) | |
50 | { | |
51 | raw_notifier_chain_register(&xen_resume_notifier, nb); | |
52 | } | |
53 | EXPORT_SYMBOL_GPL(xen_resume_notifier_register); | |
54 | ||
55 | void xen_resume_notifier_unregister(struct notifier_block *nb) | |
56 | { | |
57 | raw_notifier_chain_unregister(&xen_resume_notifier, nb); | |
58 | } | |
59 | EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister); | |
60 | ||
65e053a7 | 61 | #ifdef CONFIG_HIBERNATE_CALLBACKS |
016b6f5f SS |
62 | static int xen_suspend(void *data) |
63 | { | |
ceb18029 | 64 | struct suspend_info *si = data; |
359cdd3f | 65 | int err; |
0e91398f JF |
66 | |
67 | BUG_ON(!irqs_disabled()); | |
68 | ||
2e711c04 | 69 | err = syscore_suspend(); |
770824bd | 70 | if (err) { |
283c0972 | 71 | pr_err("%s: system core suspend failed: %d\n", __func__, err); |
770824bd RW |
72 | return err; |
73 | } | |
359cdd3f | 74 | |
aa8532c3 | 75 | gnttab_suspend(); |
5e25f5db | 76 | xen_manage_runstate_time(-1); |
aa8532c3 | 77 | xen_arch_pre_suspend(); |
0e91398f | 78 | |
aa8532c3 | 79 | si->cancelled = HYPERVISOR_suspend(xen_pv_domain() |
0df4f266 | 80 | ? virt_to_gfn(xen_start_info) |
aa8532c3 | 81 | : 0); |
0e91398f | 82 | |
aa8532c3 | 83 | xen_arch_post_suspend(si->cancelled); |
5e25f5db | 84 | xen_manage_runstate_time(si->cancelled ? 1 : 0); |
aa8532c3 | 85 | gnttab_resume(); |
0e91398f | 86 | |
ceb18029 | 87 | if (!si->cancelled) { |
0e91398f | 88 | xen_irq_resume(); |
ad55db9f | 89 | xen_timer_resume(); |
0e91398f JF |
90 | } |
91 | ||
19234c08 | 92 | syscore_resume(); |
1e6fcf84 | 93 | |
0e91398f JF |
94 | return 0; |
95 | } | |
96 | ||
97 | static void do_suspend(void) | |
98 | { | |
99 | int err; | |
ceb18029 | 100 | struct suspend_info si; |
0e91398f JF |
101 | |
102 | shutting_down = SHUTDOWN_SUSPEND; | |
103 | ||
0e91398f JF |
104 | err = freeze_processes(); |
105 | if (err) { | |
72978b2f | 106 | pr_err("%s: freeze processes failed %d\n", __func__, err); |
3fc1f1e2 | 107 | goto out; |
0e91398f | 108 | } |
0e91398f | 109 | |
72978b2f RL |
110 | err = freeze_kernel_threads(); |
111 | if (err) { | |
112 | pr_err("%s: freeze kernel threads failed %d\n", __func__, err); | |
113 | goto out_thaw; | |
114 | } | |
115 | ||
b3e96c0c | 116 | err = dpm_suspend_start(PMSG_FREEZE); |
0e91398f | 117 | if (err) { |
283c0972 | 118 | pr_err("%s: dpm_suspend_start %d\n", __func__, err); |
65f63384 | 119 | goto out_thaw; |
0e91398f JF |
120 | } |
121 | ||
c5cae661 IC |
122 | printk(KERN_DEBUG "suspending xenstore...\n"); |
123 | xs_suspend(); | |
124 | ||
cf579dfb | 125 | err = dpm_suspend_end(PMSG_FREEZE); |
2ed8d2b3 | 126 | if (err) { |
283c0972 | 127 | pr_err("dpm_suspend_end failed: %d\n", err); |
186bab1c | 128 | si.cancelled = 0; |
65f63384 | 129 | goto out_resume; |
2ed8d2b3 RW |
130 | } |
131 | ||
2b953a5e BO |
132 | xen_arch_suspend(); |
133 | ||
ceb18029 IC |
134 | si.cancelled = 1; |
135 | ||
b056b6a0 | 136 | err = stop_machine(xen_suspend, &si, cpumask_of(0)); |
922cc38a | 137 | |
1b647823 DV |
138 | /* Resume console as early as possible. */ |
139 | if (!si.cancelled) | |
140 | xen_console_resume(); | |
141 | ||
cd979883 SG |
142 | raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); |
143 | ||
cf579dfb | 144 | dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
922cc38a | 145 | |
0e91398f | 146 | if (err) { |
283c0972 | 147 | pr_err("failed to start xen_suspend: %d\n", err); |
ceb18029 | 148 | si.cancelled = 1; |
0e91398f JF |
149 | } |
150 | ||
2b953a5e BO |
151 | xen_arch_resume(); |
152 | ||
c5cae661 | 153 | out_resume: |
2b953a5e | 154 | if (!si.cancelled) |
de5b31bd | 155 | xs_resume(); |
2b953a5e | 156 | else |
de5b31bd | 157 | xs_suspend_cancel(); |
0e91398f | 158 | |
b3e96c0c | 159 | dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); |
0e91398f | 160 | |
65f63384 | 161 | out_thaw: |
0e91398f | 162 | thaw_processes(); |
65f63384 | 163 | out: |
0e91398f JF |
164 | shutting_down = SHUTDOWN_INVALID; |
165 | } | |
1f112cee | 166 | #endif /* CONFIG_HIBERNATE_CALLBACKS */ |
3e2b8fbe | 167 | |
55271723 | 168 | struct shutdown_handler { |
44b3c7af JG |
169 | #define SHUTDOWN_CMD_SIZE 11 |
170 | const char command[SHUTDOWN_CMD_SIZE]; | |
171 | bool flag; | |
55271723 IC |
172 | void (*cb)(void); |
173 | }; | |
174 | ||
eb47f712 KRW |
175 | static 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 | } | |
55271723 IC |
187 | static void do_poweroff(void) |
188 | { | |
eb47f712 KRW |
189 | switch (system_state) { |
190 | case SYSTEM_BOOTING: | |
69a78ff2 | 191 | case SYSTEM_SCHEDULING: |
eb47f712 KRW |
192 | orderly_poweroff(true); |
193 | break; | |
194 | case SYSTEM_RUNNING: | |
195 | orderly_poweroff(false); | |
196 | break; | |
197 | default: | |
198 | /* Don't do it when we are halting/rebooting. */ | |
199 | pr_info("Ignoring Xen toolstack shutdown.\n"); | |
200 | break; | |
201 | } | |
55271723 IC |
202 | } |
203 | ||
204 | static void do_reboot(void) | |
205 | { | |
206 | shutting_down = SHUTDOWN_POWEROFF; /* ? */ | |
207 | ctrl_alt_del(); | |
208 | } | |
209 | ||
44b3c7af JG |
210 | static struct shutdown_handler shutdown_handlers[] = { |
211 | { "poweroff", true, do_poweroff }, | |
212 | { "halt", false, do_poweroff }, | |
213 | { "reboot", true, do_reboot }, | |
214 | #ifdef CONFIG_HIBERNATE_CALLBACKS | |
215 | { "suspend", true, do_suspend }, | |
216 | #endif | |
217 | }; | |
218 | ||
3e2b8fbe | 219 | static void shutdown_handler(struct xenbus_watch *watch, |
5584ea25 | 220 | const char *path, const char *token) |
3e2b8fbe JF |
221 | { |
222 | char *str; | |
223 | struct xenbus_transaction xbt; | |
224 | int err; | |
44b3c7af | 225 | int idx; |
3e2b8fbe JF |
226 | |
227 | if (shutting_down != SHUTDOWN_INVALID) | |
228 | return; | |
229 | ||
230 | again: | |
231 | err = xenbus_transaction_start(&xbt); | |
232 | if (err) | |
233 | return; | |
234 | ||
235 | str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); | |
236 | /* Ignore read errors and empty reads. */ | |
237 | if (XENBUS_IS_ERR_READ(str)) { | |
238 | xenbus_transaction_end(xbt, 1); | |
239 | return; | |
240 | } | |
241 | ||
44b3c7af JG |
242 | for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) { |
243 | if (strcmp(str, shutdown_handlers[idx].command) == 0) | |
55271723 IC |
244 | break; |
245 | } | |
246 | ||
247 | /* Only acknowledge commands which we are prepared to handle. */ | |
44b3c7af | 248 | if (idx < ARRAY_SIZE(shutdown_handlers)) |
55271723 | 249 | xenbus_write(xbt, "control", "shutdown", ""); |
3e2b8fbe JF |
250 | |
251 | err = xenbus_transaction_end(xbt, 0); | |
252 | if (err == -EAGAIN) { | |
253 | kfree(str); | |
254 | goto again; | |
255 | } | |
256 | ||
44b3c7af JG |
257 | if (idx < ARRAY_SIZE(shutdown_handlers)) { |
258 | shutdown_handlers[idx].cb(); | |
0e91398f | 259 | } else { |
283c0972 | 260 | pr_info("Ignoring shutdown request: %s\n", str); |
3e2b8fbe JF |
261 | shutting_down = SHUTDOWN_INVALID; |
262 | } | |
263 | ||
264 | kfree(str); | |
265 | } | |
266 | ||
f3bc3189 | 267 | #ifdef CONFIG_MAGIC_SYSRQ |
5584ea25 JG |
268 | static void sysrq_handler(struct xenbus_watch *watch, const char *path, |
269 | const char *token) | |
3e2b8fbe JF |
270 | { |
271 | char sysrq_key = '\0'; | |
272 | struct xenbus_transaction xbt; | |
273 | int err; | |
274 | ||
275 | again: | |
276 | err = xenbus_transaction_start(&xbt); | |
277 | if (err) | |
278 | return; | |
4e93b648 JG |
279 | err = xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key); |
280 | if (err < 0) { | |
281 | /* | |
282 | * The Xenstore watch fires directly after registering it and | |
283 | * after a suspend/resume cycle. So ENOENT is no error but | |
87dffe86 VK |
284 | * might happen in those cases. ERANGE is observed when we get |
285 | * an empty value (''), this happens when we acknowledge the | |
286 | * request by writing '\0' below. | |
4e93b648 | 287 | */ |
87dffe86 | 288 | if (err != -ENOENT && err != -ERANGE) |
4e93b648 JG |
289 | pr_err("Error %d reading sysrq code in control/sysrq\n", |
290 | err); | |
3e2b8fbe JF |
291 | xenbus_transaction_end(xbt, 1); |
292 | return; | |
293 | } | |
294 | ||
84c029a7 ZJ |
295 | if (sysrq_key != '\0') { |
296 | err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); | |
297 | if (err) { | |
298 | pr_err("%s: Error %d writing sysrq in control/sysrq\n", | |
299 | __func__, err); | |
300 | xenbus_transaction_end(xbt, 1); | |
301 | return; | |
302 | } | |
303 | } | |
3e2b8fbe JF |
304 | |
305 | err = xenbus_transaction_end(xbt, 0); | |
306 | if (err == -EAGAIN) | |
307 | goto again; | |
308 | ||
309 | if (sysrq_key != '\0') | |
f335397d | 310 | handle_sysrq(sysrq_key); |
3e2b8fbe JF |
311 | } |
312 | ||
3e2b8fbe JF |
313 | static struct xenbus_watch sysrq_watch = { |
314 | .node = "control/sysrq", | |
315 | .callback = sysrq_handler | |
316 | }; | |
f3bc3189 RD |
317 | #endif |
318 | ||
319 | static struct xenbus_watch shutdown_watch = { | |
320 | .node = "control/shutdown", | |
321 | .callback = shutdown_handler | |
322 | }; | |
3e2b8fbe | 323 | |
eb47f712 KRW |
324 | static struct notifier_block xen_reboot_nb = { |
325 | .notifier_call = poweroff_nb, | |
326 | }; | |
327 | ||
3e2b8fbe JF |
328 | static int setup_shutdown_watcher(void) |
329 | { | |
330 | int err; | |
44b3c7af JG |
331 | int idx; |
332 | #define FEATURE_PATH_SIZE (SHUTDOWN_CMD_SIZE + sizeof("feature-")) | |
333 | char node[FEATURE_PATH_SIZE]; | |
3e2b8fbe JF |
334 | |
335 | err = register_xenbus_watch(&shutdown_watch); | |
336 | if (err) { | |
283c0972 | 337 | pr_err("Failed to set shutdown watcher\n"); |
3e2b8fbe JF |
338 | return err; |
339 | } | |
340 | ||
eb47f712 | 341 | |
f3bc3189 | 342 | #ifdef CONFIG_MAGIC_SYSRQ |
3e2b8fbe JF |
343 | err = register_xenbus_watch(&sysrq_watch); |
344 | if (err) { | |
283c0972 | 345 | pr_err("Failed to set sysrq watcher\n"); |
3e2b8fbe JF |
346 | return err; |
347 | } | |
f3bc3189 | 348 | #endif |
3e2b8fbe | 349 | |
44b3c7af JG |
350 | for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) { |
351 | if (!shutdown_handlers[idx].flag) | |
352 | continue; | |
353 | snprintf(node, FEATURE_PATH_SIZE, "feature-%s", | |
354 | shutdown_handlers[idx].command); | |
84c029a7 ZJ |
355 | err = xenbus_printf(XBT_NIL, "control", node, "%u", 1); |
356 | if (err) { | |
357 | pr_err("%s: Error %d writing %s\n", __func__, | |
358 | err, node); | |
359 | return err; | |
360 | } | |
44b3c7af JG |
361 | } |
362 | ||
3e2b8fbe JF |
363 | return 0; |
364 | } | |
365 | ||
366 | static int shutdown_event(struct notifier_block *notifier, | |
367 | unsigned long event, | |
368 | void *data) | |
369 | { | |
370 | setup_shutdown_watcher(); | |
371 | return NOTIFY_DONE; | |
372 | } | |
373 | ||
016b6f5f | 374 | int xen_setup_shutdown_event(void) |
3e2b8fbe JF |
375 | { |
376 | static struct notifier_block xenstore_notifier = { | |
377 | .notifier_call = shutdown_event | |
378 | }; | |
702d4eb9 SS |
379 | |
380 | if (!xen_domain()) | |
381 | return -ENODEV; | |
3e2b8fbe | 382 | register_xenstore_notifier(&xenstore_notifier); |
eb47f712 | 383 | register_reboot_notifier(&xen_reboot_nb); |
3e2b8fbe JF |
384 | |
385 | return 0; | |
386 | } | |
183d03cc | 387 | EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); |
3e2b8fbe | 388 | |
702d4eb9 | 389 | subsys_initcall(xen_setup_shutdown_event); |