xref: /freebsd/sys/dev/xen/control/control.c (revision c89f1f12b07be43df17cde53a0dcaf4f3a271eba)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND BSD-4-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  * PV suspend/resume support:
35  *
36  * Copyright (c) 2004 Christian Limpach.
37  * Copyright (c) 2004-2006,2008 Kip Macy
38  * All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  * 3. All advertising materials mentioning features or use of this software
49  *    must display the following acknowledgement:
50  *      This product includes software developed by Christian Limpach.
51  * 4. The name of the author may not be used to endorse or promote products
52  *    derived from this software without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
55  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
56  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
57  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
58  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
59  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
60  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
61  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
62  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
63  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64  */
65 
66 /*-
67  * HVM suspend/resume support:
68  *
69  * Copyright (c) 2008 Citrix Systems, Inc.
70  * All rights reserved.
71  *
72  * Redistribution and use in source and binary forms, with or without
73  * modification, are permitted provided that the following conditions
74  * are met:
75  * 1. Redistributions of source code must retain the above copyright
76  *    notice, this list of conditions and the following disclaimer.
77  * 2. Redistributions in binary form must reproduce the above copyright
78  *    notice, this list of conditions and the following disclaimer in the
79  *    documentation and/or other materials provided with the distribution.
80  *
81  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
82  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
83  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
84  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
85  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
86  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
87  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
88  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
89  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
90  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
91  * SUCH DAMAGE.
92  */
93 #include <sys/cdefs.h>
94 __FBSDID("$FreeBSD$");
95 
96 /**
97  * \file control.c
98  *
99  * \brief Device driver to repond to control domain events that impact
100  *        this VM.
101  */
102 
103 #include <sys/param.h>
104 #include <sys/systm.h>
105 #include <sys/kernel.h>
106 #include <sys/malloc.h>
107 
108 #include <sys/bio.h>
109 #include <sys/bus.h>
110 #include <sys/conf.h>
111 #include <sys/disk.h>
112 #include <sys/fcntl.h>
113 #include <sys/filedesc.h>
114 #include <sys/kdb.h>
115 #include <sys/module.h>
116 #include <sys/mount.h>
117 #include <sys/namei.h>
118 #include <sys/proc.h>
119 #include <sys/reboot.h>
120 #include <sys/rman.h>
121 #include <sys/sched.h>
122 #include <sys/taskqueue.h>
123 #include <sys/types.h>
124 #include <sys/vnode.h>
125 #include <sys/sched.h>
126 #include <sys/smp.h>
127 #include <sys/eventhandler.h>
128 #include <sys/timetc.h>
129 
130 #include <geom/geom.h>
131 
132 #include <machine/_inttypes.h>
133 #include <machine/intr_machdep.h>
134 
135 #if defined(__amd64__) || defined(__i386__)
136 #include <x86/apicvar.h>
137 #endif
138 
139 #include <vm/vm.h>
140 #include <vm/vm_extern.h>
141 #include <vm/vm_kern.h>
142 
143 #include <xen/xen-os.h>
144 #include <xen/blkif.h>
145 #include <xen/evtchn.h>
146 #include <xen/gnttab.h>
147 #include <xen/xen_intr.h>
148 
149 #include <xen/hvm.h>
150 
151 #include <xen/interface/event_channel.h>
152 #include <xen/interface/grant_table.h>
153 
154 #include <xen/xenbus/xenbusvar.h>
155 
156 bool xen_suspend_cancelled;
157 /*--------------------------- Forward Declarations --------------------------*/
158 /** Function signature for shutdown event handlers. */
159 typedef	void (xctrl_shutdown_handler_t)(void);
160 
161 static xctrl_shutdown_handler_t xctrl_poweroff;
162 static xctrl_shutdown_handler_t xctrl_reboot;
163 static xctrl_shutdown_handler_t xctrl_suspend;
164 static xctrl_shutdown_handler_t xctrl_crash;
165 
166 /*-------------------------- Private Data Structures -------------------------*/
167 /** Element type for lookup table of event name to handler. */
168 struct xctrl_shutdown_reason {
169 	const char		 *name;
170 	xctrl_shutdown_handler_t *handler;
171 };
172 
173 /** Lookup table for shutdown event name to handler. */
174 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
175 	{ "poweroff", xctrl_poweroff },
176 	{ "reboot",   xctrl_reboot   },
177 	{ "suspend",  xctrl_suspend  },
178 	{ "crash",    xctrl_crash    },
179 	{ "halt",     xctrl_poweroff },
180 };
181 
182 struct xctrl_softc {
183 	struct xs_watch    xctrl_watch;
184 };
185 
186 /*------------------------------ Event Handlers ------------------------------*/
187 static void
188 xctrl_poweroff()
189 {
190 	shutdown_nice(RB_POWEROFF|RB_HALT);
191 }
192 
193 static void
194 xctrl_reboot()
195 {
196 	shutdown_nice(0);
197 }
198 
199 static void
200 xctrl_suspend()
201 {
202 #ifdef SMP
203 	cpuset_t cpu_suspend_map;
204 #endif
205 
206 	EVENTHANDLER_INVOKE(power_suspend_early);
207 	xs_lock();
208 	stop_all_proc();
209 	xs_unlock();
210 	suspend_all_fs();
211 	EVENTHANDLER_INVOKE(power_suspend);
212 
213 #ifdef EARLY_AP_STARTUP
214 	MPASS(mp_ncpus == 1 || smp_started);
215 	thread_lock(curthread);
216 	sched_bind(curthread, 0);
217 	thread_unlock(curthread);
218 #else
219 	if (smp_started) {
220 		thread_lock(curthread);
221 		sched_bind(curthread, 0);
222 		thread_unlock(curthread);
223 	}
224 #endif
225 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
226 
227 	/*
228 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
229 	 * drivers need this.
230 	 */
231 	mtx_lock(&Giant);
232 	if (DEVICE_SUSPEND(root_bus) != 0) {
233 		mtx_unlock(&Giant);
234 		printf("%s: device_suspend failed\n", __func__);
235 		return;
236 	}
237 
238 #ifdef SMP
239 #ifdef EARLY_AP_STARTUP
240 	/*
241 	 * Suspend other CPUs. This prevents IPIs while we
242 	 * are resuming, and will allow us to reset per-cpu
243 	 * vcpu_info on resume.
244 	 */
245 	cpu_suspend_map = all_cpus;
246 	CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
247 	if (!CPU_EMPTY(&cpu_suspend_map))
248 		suspend_cpus(cpu_suspend_map);
249 #else
250 	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
251 	if (smp_started) {
252 		/*
253 		 * Suspend other CPUs. This prevents IPIs while we
254 		 * are resuming, and will allow us to reset per-cpu
255 		 * vcpu_info on resume.
256 		 */
257 		cpu_suspend_map = all_cpus;
258 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
259 		if (!CPU_EMPTY(&cpu_suspend_map))
260 			suspend_cpus(cpu_suspend_map);
261 	}
262 #endif
263 #endif
264 
265 	/*
266 	 * Prevent any races with evtchn_interrupt() handler.
267 	 */
268 	disable_intr();
269 	intr_suspend();
270 	xen_hvm_suspend();
271 
272 	xen_suspend_cancelled = !!HYPERVISOR_suspend(0);
273 
274 	if (!xen_suspend_cancelled) {
275 		xen_hvm_resume(false);
276 	}
277 	intr_resume(xen_suspend_cancelled != 0);
278 	enable_intr();
279 
280 	/*
281 	 * Reset grant table info.
282 	 */
283 	if (!xen_suspend_cancelled) {
284 		gnttab_resume(NULL);
285 	}
286 
287 #ifdef SMP
288 	if (!CPU_EMPTY(&cpu_suspend_map)) {
289 		/*
290 		 * Now that event channels have been initialized,
291 		 * resume CPUs.
292 		 */
293 		resume_cpus(cpu_suspend_map);
294 #if defined(__amd64__) || defined(__i386__)
295 		/* Send an IPI_BITMAP in case there are pending bitmap IPIs. */
296 		lapic_ipi_vectored(IPI_BITMAP_VECTOR, APIC_IPI_DEST_ALL);
297 #endif
298 	}
299 #endif
300 
301 	/*
302 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
303 	 * similar.
304 	 */
305 	DEVICE_RESUME(root_bus);
306 	mtx_unlock(&Giant);
307 
308 	/*
309 	 * Warm up timecounter again and reset system clock.
310 	 */
311 	timecounter->tc_get_timecount(timecounter);
312 	inittodr(time_second);
313 
314 #ifdef EARLY_AP_STARTUP
315 	thread_lock(curthread);
316 	sched_unbind(curthread);
317 	thread_unlock(curthread);
318 #else
319 	if (smp_started) {
320 		thread_lock(curthread);
321 		sched_unbind(curthread);
322 		thread_unlock(curthread);
323 	}
324 #endif
325 
326 	resume_all_fs();
327 	resume_all_proc();
328 
329 	EVENTHANDLER_INVOKE(power_resume);
330 
331 	if (bootverbose)
332 		printf("System resumed after suspension\n");
333 
334 }
335 
336 static void
337 xctrl_crash()
338 {
339 	panic("Xen directed crash");
340 }
341 
342 static void
343 xen_pv_shutdown_final(void *arg, int howto)
344 {
345 	/*
346 	 * Inform the hypervisor that shutdown is complete.
347 	 * This is not necessary in HVM domains since Xen
348 	 * emulates ACPI in that mode and FreeBSD's ACPI
349 	 * support will request this transition.
350 	 */
351 	if (howto & (RB_HALT | RB_POWEROFF))
352 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
353 	else
354 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
355 }
356 
357 /*------------------------------ Event Reception -----------------------------*/
358 static void
359 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
360 {
361 	const struct xctrl_shutdown_reason *reason;
362 	const struct xctrl_shutdown_reason *last_reason;
363 	char *result;
364 	int   error;
365 	int   result_len;
366 
367 	error = xs_read(XST_NIL, "control", "shutdown",
368 			&result_len, (void **)&result);
369 	if (error != 0 || result_len == 0)
370 		return;
371 
372 	/* Acknowledge the request by writing back an empty string. */
373 	error = xs_write(XST_NIL, "control", "shutdown", "");
374 	if (error != 0)
375 		printf("unable to ack shutdown request, proceeding anyway\n");
376 
377 	reason = xctrl_shutdown_reasons;
378 	last_reason = reason + nitems(xctrl_shutdown_reasons);
379 	while (reason < last_reason) {
380 		if (!strcmp(result, reason->name)) {
381 			reason->handler();
382 			break;
383 		}
384 		reason++;
385 	}
386 
387 	free(result, M_XENSTORE);
388 }
389 
390 /*------------------ Private Device Attachment Functions  --------------------*/
391 /**
392  * \brief Identify instances of this device type in the system.
393  *
394  * \param driver  The driver performing this identify action.
395  * \param parent  The NewBus parent device for any devices this method adds.
396  */
397 static void
398 xctrl_identify(driver_t *driver __unused, device_t parent)
399 {
400 	/*
401 	 * A single device instance for our driver is always present
402 	 * in a system operating under Xen.
403 	 */
404 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
405 }
406 
407 /**
408  * \brief Probe for the existence of the Xen Control device
409  *
410  * \param dev  NewBus device_t for this Xen control instance.
411  *
412  * \return  Always returns 0 indicating success.
413  */
414 static int
415 xctrl_probe(device_t dev)
416 {
417 	device_set_desc(dev, "Xen Control Device");
418 
419 	return (BUS_PROBE_NOWILDCARD);
420 }
421 
422 /**
423  * \brief Attach the Xen control device.
424  *
425  * \param dev  NewBus device_t for this Xen control instance.
426  *
427  * \return  On success, 0. Otherwise an errno value indicating the
428  *          type of failure.
429  */
430 static int
431 xctrl_attach(device_t dev)
432 {
433 	struct xctrl_softc *xctrl;
434 
435 	xctrl = device_get_softc(dev);
436 
437 	/* Activate watch */
438 	xctrl->xctrl_watch.node = "control/shutdown";
439 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
440 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
441 	/*
442 	 * We don't care about the path updated, just about the value changes
443 	 * on that single node, hence there's no need to queue more that one
444 	 * event.
445 	 */
446 	xctrl->xctrl_watch.max_pending = 1;
447 	xs_register_watch(&xctrl->xctrl_watch);
448 
449 	if (xen_pv_domain())
450 		EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
451 		                      SHUTDOWN_PRI_LAST);
452 
453 	return (0);
454 }
455 
456 /**
457  * \brief Detach the Xen control device.
458  *
459  * \param dev  NewBus device_t for this Xen control device instance.
460  *
461  * \return  On success, 0. Otherwise an errno value indicating the
462  *          type of failure.
463  */
464 static int
465 xctrl_detach(device_t dev)
466 {
467 	struct xctrl_softc *xctrl;
468 
469 	xctrl = device_get_softc(dev);
470 
471 	/* Release watch */
472 	xs_unregister_watch(&xctrl->xctrl_watch);
473 
474 	return (0);
475 }
476 
477 /*-------------------- Private Device Attachment Data  -----------------------*/
478 static device_method_t xctrl_methods[] = {
479 	/* Device interface */
480 	DEVMETHOD(device_identify,	xctrl_identify),
481 	DEVMETHOD(device_probe,         xctrl_probe),
482 	DEVMETHOD(device_attach,        xctrl_attach),
483 	DEVMETHOD(device_detach,        xctrl_detach),
484 
485 	DEVMETHOD_END
486 };
487 
488 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
489 devclass_t xctrl_devclass;
490 
491 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
492