xref: /freebsd/sys/dev/xen/control/control.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
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 #include <x86/apicvar.h>
136 
137 #include <vm/vm.h>
138 #include <vm/vm_extern.h>
139 #include <vm/vm_kern.h>
140 
141 #include <xen/xen-os.h>
142 #include <xen/blkif.h>
143 #include <xen/evtchn.h>
144 #include <xen/gnttab.h>
145 #include <xen/xen_intr.h>
146 
147 #include <xen/hvm.h>
148 
149 #include <xen/interface/event_channel.h>
150 #include <xen/interface/grant_table.h>
151 
152 #include <xen/xenbus/xenbusvar.h>
153 
154 bool xen_suspend_cancelled;
155 /*--------------------------- Forward Declarations --------------------------*/
156 /** Function signature for shutdown event handlers. */
157 typedef	void (xctrl_shutdown_handler_t)(void);
158 
159 static xctrl_shutdown_handler_t xctrl_poweroff;
160 static xctrl_shutdown_handler_t xctrl_reboot;
161 static xctrl_shutdown_handler_t xctrl_suspend;
162 static xctrl_shutdown_handler_t xctrl_crash;
163 
164 /*-------------------------- Private Data Structures -------------------------*/
165 /** Element type for lookup table of event name to handler. */
166 struct xctrl_shutdown_reason {
167 	const char		 *name;
168 	xctrl_shutdown_handler_t *handler;
169 };
170 
171 /** Lookup table for shutdown event name to handler. */
172 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
173 	{ "poweroff", xctrl_poweroff },
174 	{ "reboot",   xctrl_reboot   },
175 	{ "suspend",  xctrl_suspend  },
176 	{ "crash",    xctrl_crash    },
177 	{ "halt",     xctrl_poweroff },
178 };
179 
180 struct xctrl_softc {
181 	struct xs_watch    xctrl_watch;
182 };
183 
184 /*------------------------------ Event Handlers ------------------------------*/
185 static void
186 xctrl_poweroff()
187 {
188 	shutdown_nice(RB_POWEROFF|RB_HALT);
189 }
190 
191 static void
192 xctrl_reboot()
193 {
194 	shutdown_nice(0);
195 }
196 
197 static void
198 xctrl_suspend()
199 {
200 #ifdef SMP
201 	cpuset_t cpu_suspend_map;
202 #endif
203 
204 	EVENTHANDLER_INVOKE(power_suspend_early);
205 	xs_lock();
206 	stop_all_proc();
207 	xs_unlock();
208 	suspend_all_fs();
209 	EVENTHANDLER_INVOKE(power_suspend);
210 
211 #ifdef EARLY_AP_STARTUP
212 	MPASS(mp_ncpus == 1 || smp_started);
213 	thread_lock(curthread);
214 	sched_bind(curthread, 0);
215 	thread_unlock(curthread);
216 #else
217 	if (smp_started) {
218 		thread_lock(curthread);
219 		sched_bind(curthread, 0);
220 		thread_unlock(curthread);
221 	}
222 #endif
223 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
224 
225 	/*
226 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
227 	 * drivers need this.
228 	 */
229 	mtx_lock(&Giant);
230 	if (DEVICE_SUSPEND(root_bus) != 0) {
231 		mtx_unlock(&Giant);
232 		printf("%s: device_suspend failed\n", __func__);
233 		return;
234 	}
235 
236 #ifdef SMP
237 #ifdef EARLY_AP_STARTUP
238 	/*
239 	 * Suspend other CPUs. This prevents IPIs while we
240 	 * are resuming, and will allow us to reset per-cpu
241 	 * vcpu_info on resume.
242 	 */
243 	cpu_suspend_map = all_cpus;
244 	CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
245 	if (!CPU_EMPTY(&cpu_suspend_map))
246 		suspend_cpus(cpu_suspend_map);
247 #else
248 	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
249 	if (smp_started) {
250 		/*
251 		 * Suspend other CPUs. This prevents IPIs while we
252 		 * are resuming, and will allow us to reset per-cpu
253 		 * vcpu_info on resume.
254 		 */
255 		cpu_suspend_map = all_cpus;
256 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
257 		if (!CPU_EMPTY(&cpu_suspend_map))
258 			suspend_cpus(cpu_suspend_map);
259 	}
260 #endif
261 #endif
262 
263 	/*
264 	 * Prevent any races with evtchn_interrupt() handler.
265 	 */
266 	disable_intr();
267 	intr_suspend();
268 	xen_hvm_suspend();
269 
270 	xen_suspend_cancelled = !!HYPERVISOR_suspend(0);
271 
272 	if (!xen_suspend_cancelled) {
273 		xen_hvm_resume(false);
274 	}
275 	intr_resume(xen_suspend_cancelled != 0);
276 	enable_intr();
277 
278 	/*
279 	 * Reset grant table info.
280 	 */
281 	if (!xen_suspend_cancelled) {
282 		gnttab_resume(NULL);
283 	}
284 
285 #ifdef SMP
286 	if (!CPU_EMPTY(&cpu_suspend_map)) {
287 		/*
288 		 * Now that event channels have been initialized,
289 		 * resume CPUs.
290 		 */
291 		resume_cpus(cpu_suspend_map);
292 		/* Send an IPI_BITMAP in case there are pending bitmap IPIs. */
293 		lapic_ipi_vectored(IPI_BITMAP_VECTOR, APIC_IPI_DEST_ALL);
294 	}
295 #endif
296 
297 	/*
298 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
299 	 * similar.
300 	 */
301 	DEVICE_RESUME(root_bus);
302 	mtx_unlock(&Giant);
303 
304 	/*
305 	 * Warm up timecounter again and reset system clock.
306 	 */
307 	timecounter->tc_get_timecount(timecounter);
308 	inittodr(time_second);
309 
310 #ifdef EARLY_AP_STARTUP
311 	thread_lock(curthread);
312 	sched_unbind(curthread);
313 	thread_unlock(curthread);
314 #else
315 	if (smp_started) {
316 		thread_lock(curthread);
317 		sched_unbind(curthread);
318 		thread_unlock(curthread);
319 	}
320 #endif
321 
322 	resume_all_fs();
323 	resume_all_proc();
324 
325 	EVENTHANDLER_INVOKE(power_resume);
326 
327 	if (bootverbose)
328 		printf("System resumed after suspension\n");
329 
330 }
331 
332 static void
333 xctrl_crash()
334 {
335 	panic("Xen directed crash");
336 }
337 
338 static void
339 xen_pv_shutdown_final(void *arg, int howto)
340 {
341 	/*
342 	 * Inform the hypervisor that shutdown is complete.
343 	 * This is not necessary in HVM domains since Xen
344 	 * emulates ACPI in that mode and FreeBSD's ACPI
345 	 * support will request this transition.
346 	 */
347 	if (howto & (RB_HALT | RB_POWEROFF))
348 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
349 	else
350 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
351 }
352 
353 /*------------------------------ Event Reception -----------------------------*/
354 static void
355 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
356 {
357 	const struct xctrl_shutdown_reason *reason;
358 	const struct xctrl_shutdown_reason *last_reason;
359 	char *result;
360 	int   error;
361 	int   result_len;
362 
363 	error = xs_read(XST_NIL, "control", "shutdown",
364 			&result_len, (void **)&result);
365 	if (error != 0 || result_len == 0)
366 		return;
367 
368 	/* Acknowledge the request by writing back an empty string. */
369 	error = xs_write(XST_NIL, "control", "shutdown", "");
370 	if (error != 0)
371 		printf("unable to ack shutdown request, proceeding anyway\n");
372 
373 	reason = xctrl_shutdown_reasons;
374 	last_reason = reason + nitems(xctrl_shutdown_reasons);
375 	while (reason < last_reason) {
376 		if (!strcmp(result, reason->name)) {
377 			reason->handler();
378 			break;
379 		}
380 		reason++;
381 	}
382 
383 	free(result, M_XENSTORE);
384 }
385 
386 /*------------------ Private Device Attachment Functions  --------------------*/
387 /**
388  * \brief Identify instances of this device type in the system.
389  *
390  * \param driver  The driver performing this identify action.
391  * \param parent  The NewBus parent device for any devices this method adds.
392  */
393 static void
394 xctrl_identify(driver_t *driver __unused, device_t parent)
395 {
396 	/*
397 	 * A single device instance for our driver is always present
398 	 * in a system operating under Xen.
399 	 */
400 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
401 }
402 
403 /**
404  * \brief Probe for the existence of the Xen Control device
405  *
406  * \param dev  NewBus device_t for this Xen control instance.
407  *
408  * \return  Always returns 0 indicating success.
409  */
410 static int
411 xctrl_probe(device_t dev)
412 {
413 	device_set_desc(dev, "Xen Control Device");
414 
415 	return (BUS_PROBE_NOWILDCARD);
416 }
417 
418 /**
419  * \brief Attach the Xen control device.
420  *
421  * \param dev  NewBus device_t for this Xen control instance.
422  *
423  * \return  On success, 0. Otherwise an errno value indicating the
424  *          type of failure.
425  */
426 static int
427 xctrl_attach(device_t dev)
428 {
429 	struct xctrl_softc *xctrl;
430 
431 	xctrl = device_get_softc(dev);
432 
433 	/* Activate watch */
434 	xctrl->xctrl_watch.node = "control/shutdown";
435 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
436 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
437 	/*
438 	 * We don't care about the path updated, just about the value changes
439 	 * on that single node, hence there's no need to queue more that one
440 	 * event.
441 	 */
442 	xctrl->xctrl_watch.max_pending = 1;
443 	xs_register_watch(&xctrl->xctrl_watch);
444 
445 	if (xen_pv_domain())
446 		EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
447 		                      SHUTDOWN_PRI_LAST);
448 
449 	return (0);
450 }
451 
452 /**
453  * \brief Detach the Xen control device.
454  *
455  * \param dev  NewBus device_t for this Xen control device instance.
456  *
457  * \return  On success, 0. Otherwise an errno value indicating the
458  *          type of failure.
459  */
460 static int
461 xctrl_detach(device_t dev)
462 {
463 	struct xctrl_softc *xctrl;
464 
465 	xctrl = device_get_softc(dev);
466 
467 	/* Release watch */
468 	xs_unregister_watch(&xctrl->xctrl_watch);
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 
481 	DEVMETHOD_END
482 };
483 
484 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
485 devclass_t xctrl_devclass;
486 
487 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
488