1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2010 Justin T. Gibbs, Spectra Logic Corporation
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions, and the following disclaimer,
12 * without modification.
13 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
14 * substantially similar to the "NO WARRANTY" disclaimer below
15 * ("Disclaimer") and any redistribution must be conditioned upon
16 * including a substantially similar Disclaimer requirement for further
17 * binary redistribution.
18 *
19 * NO WARRANTY
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
28 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGES.
31 */
32
33 /*-
34 * HVM suspend/resume support:
35 *
36 * Copyright (c) 2008 Citrix Systems, Inc.
37 * All rights reserved.
38 *
39 * Redistribution and use in source and binary forms, with or without
40 * modification, are permitted provided that the following conditions
41 * are met:
42 * 1. Redistributions of source code must retain the above copyright
43 * notice, this list of conditions and the following disclaimer.
44 * 2. Redistributions in binary form must reproduce the above copyright
45 * notice, this list of conditions and the following disclaimer in the
46 * documentation and/or other materials provided with the distribution.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 */
60 #include <sys/cdefs.h>
61 /**
62 * \file control.c
63 *
64 * \brief Device driver to repond to control domain events that impact
65 * this VM.
66 */
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/kernel.h>
71 #include <sys/malloc.h>
72
73 #include <sys/bio.h>
74 #include <sys/bus.h>
75 #include <sys/conf.h>
76 #include <sys/disk.h>
77 #include <sys/fcntl.h>
78 #include <sys/filedesc.h>
79 #include <sys/kdb.h>
80 #include <sys/module.h>
81 #include <sys/mount.h>
82 #include <sys/namei.h>
83 #include <sys/proc.h>
84 #include <sys/reboot.h>
85 #include <sys/rman.h>
86 #include <sys/sched.h>
87 #include <sys/taskqueue.h>
88 #include <sys/types.h>
89 #include <sys/vnode.h>
90 #include <sys/sched.h>
91 #include <sys/smp.h>
92 #include <sys/eventhandler.h>
93 #include <sys/timetc.h>
94
95 #include <geom/geom.h>
96
97 #include <machine/_inttypes.h>
98 #if defined(__amd64__) || defined(__i386__)
99 #include <machine/intr_machdep.h>
100
101 #include <x86/apicvar.h>
102 #endif
103
104 #include <vm/vm.h>
105 #include <vm/vm_extern.h>
106 #include <vm/vm_kern.h>
107
108 #include <xen/xen-os.h>
109 #include <xen/blkif.h>
110 #include <xen/evtchn.h>
111 #include <xen/gnttab.h>
112 #include <xen/xen_intr.h>
113
114 #include <xen/hvm.h>
115
116 #include <contrib/xen/event_channel.h>
117 #include <contrib/xen/grant_table.h>
118
119 #include <xen/xenbus/xenbusvar.h>
120
121 bool xen_suspend_cancelled;
122 /*--------------------------- Forward Declarations --------------------------*/
123 /** Function signature for shutdown event handlers. */
124 typedef void (xctrl_shutdown_handler_t)(void);
125
126 static xctrl_shutdown_handler_t xctrl_poweroff;
127 static xctrl_shutdown_handler_t xctrl_reboot;
128 static xctrl_shutdown_handler_t xctrl_suspend;
129 static xctrl_shutdown_handler_t xctrl_crash;
130
131 /*-------------------------- Private Data Structures -------------------------*/
132 /** Element type for lookup table of event name to handler. */
133 struct xctrl_shutdown_reason {
134 const char *name;
135 xctrl_shutdown_handler_t *handler;
136 };
137
138 /** Lookup table for shutdown event name to handler. */
139 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
140 { "poweroff", xctrl_poweroff },
141 { "reboot", xctrl_reboot },
142 { "suspend", xctrl_suspend },
143 { "crash", xctrl_crash },
144 { "halt", xctrl_poweroff },
145 };
146
147 struct xctrl_softc {
148 struct xs_watch xctrl_watch;
149 };
150
151 /*------------------------------ Event Handlers ------------------------------*/
152 static void
xctrl_poweroff(void)153 xctrl_poweroff(void)
154 {
155 shutdown_nice(RB_POWEROFF|RB_HALT);
156 }
157
158 static void
xctrl_reboot(void)159 xctrl_reboot(void)
160 {
161 shutdown_nice(0);
162 }
163
164 #if !defined(__amd64__) && !defined(__i386__)
165 static void
xctrl_suspend(void)166 xctrl_suspend(void)
167 {
168 printf("WARNING: xen/control: Suspend not supported!\n");
169 }
170 #else /* __amd64__ || __i386__ */
171 static void
xctrl_suspend(void)172 xctrl_suspend(void)
173 {
174 #ifdef SMP
175 cpuset_t cpu_suspend_map;
176 #endif
177
178 EVENTHANDLER_INVOKE(power_suspend_early);
179 xs_lock();
180 stop_all_proc();
181 xs_unlock();
182 suspend_all_fs();
183 EVENTHANDLER_INVOKE(power_suspend);
184
185 #ifdef EARLY_AP_STARTUP
186 MPASS(mp_ncpus == 1 || smp_started);
187 thread_lock(curthread);
188 sched_bind(curthread, 0);
189 thread_unlock(curthread);
190 #else
191 if (smp_started) {
192 thread_lock(curthread);
193 sched_bind(curthread, 0);
194 thread_unlock(curthread);
195 }
196 #endif
197 KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
198
199 /*
200 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME.
201 */
202 bus_topo_lock();
203 if (DEVICE_SUSPEND(root_bus) != 0) {
204 bus_topo_unlock();
205 printf("%s: device_suspend failed\n", __func__);
206 return;
207 }
208
209 #ifdef SMP
210 #ifdef EARLY_AP_STARTUP
211 /*
212 * Suspend other CPUs. This prevents IPIs while we
213 * are resuming, and will allow us to reset per-cpu
214 * vcpu_info on resume.
215 */
216 cpu_suspend_map = all_cpus;
217 CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
218 if (!CPU_EMPTY(&cpu_suspend_map))
219 suspend_cpus(cpu_suspend_map);
220 #else
221 CPU_ZERO(&cpu_suspend_map); /* silence gcc */
222 if (smp_started) {
223 /*
224 * Suspend other CPUs. This prevents IPIs while we
225 * are resuming, and will allow us to reset per-cpu
226 * vcpu_info on resume.
227 */
228 cpu_suspend_map = all_cpus;
229 CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
230 if (!CPU_EMPTY(&cpu_suspend_map))
231 suspend_cpus(cpu_suspend_map);
232 }
233 #endif
234 #endif
235
236 /*
237 * Prevent any races with evtchn_interrupt() handler.
238 */
239 disable_intr();
240 intr_suspend();
241 xen_hvm_suspend();
242
243 xen_suspend_cancelled = !!HYPERVISOR_suspend(0);
244
245 if (!xen_suspend_cancelled) {
246 xen_hvm_resume(false);
247 }
248 intr_resume(xen_suspend_cancelled != 0);
249 enable_intr();
250
251 /*
252 * Reset grant table info.
253 */
254 if (!xen_suspend_cancelled) {
255 gnttab_resume(NULL);
256 }
257
258 #ifdef SMP
259 if (!CPU_EMPTY(&cpu_suspend_map)) {
260 /*
261 * Now that event channels have been initialized,
262 * resume CPUs.
263 */
264 resume_cpus(cpu_suspend_map);
265 #if defined(__amd64__) || defined(__i386__)
266 /* Send an IPI_BITMAP in case there are pending bitmap IPIs. */
267 lapic_ipi_vectored(IPI_BITMAP_VECTOR, APIC_IPI_DEST_ALL);
268 #endif
269 }
270 #endif
271
272 /*
273 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
274 * similar.
275 */
276 DEVICE_RESUME(root_bus);
277 bus_topo_unlock();
278
279 /*
280 * Warm up timecounter again and reset system clock.
281 */
282 timecounter->tc_get_timecount(timecounter);
283 inittodr(time_second);
284
285 #ifdef EARLY_AP_STARTUP
286 thread_lock(curthread);
287 sched_unbind(curthread);
288 thread_unlock(curthread);
289 #else
290 if (smp_started) {
291 thread_lock(curthread);
292 sched_unbind(curthread);
293 thread_unlock(curthread);
294 }
295 #endif
296
297 resume_all_fs();
298 resume_all_proc();
299
300 EVENTHANDLER_INVOKE(power_resume);
301
302 if (bootverbose)
303 printf("System resumed after suspension\n");
304
305 }
306 #endif /* __amd64__ || __i386__ */
307
308 static void
xctrl_crash(void)309 xctrl_crash(void)
310 {
311 panic("Xen directed crash");
312 }
313
314 static void
xctrl_shutdown_final(void * arg,int howto)315 xctrl_shutdown_final(void *arg, int howto)
316 {
317 /*
318 * Inform the hypervisor that shutdown is complete, and specify the
319 * nature of the shutdown. RB_HALT is not handled by this function.
320 */
321 if (KERNEL_PANICKED())
322 HYPERVISOR_shutdown(SHUTDOWN_crash);
323 else if ((howto & RB_POWEROFF) != 0)
324 HYPERVISOR_shutdown(SHUTDOWN_poweroff);
325 else if ((howto & RB_HALT) == 0)
326 /* RB_POWERCYCLE or regular reset. */
327 HYPERVISOR_shutdown(SHUTDOWN_reboot);
328 }
329
330 /*------------------------------ Event Reception -----------------------------*/
331 static void
xctrl_on_watch_event(struct xs_watch * watch,const char ** vec,unsigned int len)332 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
333 {
334 const struct xctrl_shutdown_reason *reason;
335 const struct xctrl_shutdown_reason *last_reason;
336 char *result;
337 int error;
338 int result_len;
339
340 error = xs_read(XST_NIL, "control", "shutdown",
341 &result_len, (void **)&result);
342 if (error != 0 || result_len == 0)
343 return;
344
345 /* Acknowledge the request by writing back an empty string. */
346 error = xs_write(XST_NIL, "control", "shutdown", "");
347 if (error != 0)
348 printf("unable to ack shutdown request, proceeding anyway\n");
349
350 reason = xctrl_shutdown_reasons;
351 last_reason = reason + nitems(xctrl_shutdown_reasons);
352 while (reason < last_reason) {
353 if (!strcmp(result, reason->name)) {
354 reason->handler();
355 break;
356 }
357 reason++;
358 }
359
360 free(result, M_XENSTORE);
361 }
362
363 /*------------------ Private Device Attachment Functions --------------------*/
364
365 static void
notify_support(void)366 notify_support(void)
367 {
368 /*
369 * Notify kernel is ready to handle "control/shutdown" events. Ignore
370 * errors if the nodes haven't been created by the toolstack, as the
371 * parent "control" directory should be read-only for the guest.
372 */
373 xs_write(XST_NIL, "control", "feature-poweroff", "1");
374 xs_write(XST_NIL, "control", "feature-reboot", "1");
375 xs_write(XST_NIL, "control", "feature-suspend", "1");
376 }
377
378 /**
379 * \brief Identify instances of this device type in the system.
380 *
381 * \param driver The driver performing this identify action.
382 * \param parent The NewBus parent device for any devices this method adds.
383 */
384 static void
xctrl_identify(driver_t * driver,device_t parent)385 xctrl_identify(driver_t *driver, device_t parent)
386 {
387 /*
388 * A single device instance for our driver is always present
389 * in a system operating under Xen.
390 */
391 BUS_ADD_CHILD(parent, 0, driver->name, 0);
392 }
393
394 /**
395 * \brief Probe for the existence of the Xen Control device
396 *
397 * \param dev NewBus device_t for this Xen control instance.
398 *
399 * \return Always returns 0 indicating success.
400 */
401 static int
xctrl_probe(device_t dev)402 xctrl_probe(device_t dev)
403 {
404 device_set_desc(dev, "Xen Control Device");
405
406 return (BUS_PROBE_NOWILDCARD);
407 }
408
409 /**
410 * \brief Attach the Xen control device.
411 *
412 * \param dev NewBus device_t for this Xen control instance.
413 *
414 * \return On success, 0. Otherwise an errno value indicating the
415 * type of failure.
416 */
417 static int
xctrl_attach(device_t dev)418 xctrl_attach(device_t dev)
419 {
420 struct xctrl_softc *xctrl;
421
422 xctrl = device_get_softc(dev);
423
424 /* Activate watch */
425 xctrl->xctrl_watch.node = "control/shutdown";
426 xctrl->xctrl_watch.callback = xctrl_on_watch_event;
427 xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
428 /*
429 * We don't care about the path updated, just about the value changes
430 * on that single node, hence there's no need to queue more that one
431 * event.
432 */
433 xctrl->xctrl_watch.max_pending = 1;
434 xs_register_watch(&xctrl->xctrl_watch);
435
436 EVENTHANDLER_REGISTER(shutdown_final, xctrl_shutdown_final, NULL,
437 SHUTDOWN_PRI_LAST);
438
439 notify_support();
440
441 return (0);
442 }
443
444 /**
445 * \brief Detach the Xen control device.
446 *
447 * \param dev NewBus device_t for this Xen control device instance.
448 *
449 * \return On success, 0. Otherwise an errno value indicating the
450 * type of failure.
451 */
452 static int
xctrl_detach(device_t dev)453 xctrl_detach(device_t dev)
454 {
455 struct xctrl_softc *xctrl;
456
457 xctrl = device_get_softc(dev);
458
459 /* Release watch */
460 xs_unregister_watch(&xctrl->xctrl_watch);
461
462 return (0);
463 }
464
465 static int
xctrl_resume(device_t dev)466 xctrl_resume(device_t dev)
467 {
468 notify_support();
469
470 return (0);
471 }
472
473 /*-------------------- Private Device Attachment Data -----------------------*/
474 static device_method_t xctrl_methods[] = {
475 /* Device interface */
476 DEVMETHOD(device_identify, xctrl_identify),
477 DEVMETHOD(device_probe, xctrl_probe),
478 DEVMETHOD(device_attach, xctrl_attach),
479 DEVMETHOD(device_detach, xctrl_detach),
480 DEVMETHOD(device_resume, xctrl_resume),
481
482 DEVMETHOD_END
483 };
484
485 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
486
487 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, NULL, NULL);
488