xref: /freebsd/sys/dev/xen/control/control.c (revision ca46f3289d9630a9b203379333b46f3f11363146)
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 #if defined(__amd64__) || defined(__i386__)
134 #include <machine/intr_machdep.h>
135 
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 #if !defined(__amd64__) && !defined(__i386__)
200 static void
201 xctrl_suspend()
202 {
203 	printf("WARNING: xen/control: Suspend not supported!\n");
204 }
205 #else /* __amd64__ || __i386__ */
206 static void
207 xctrl_suspend()
208 {
209 #ifdef SMP
210 	cpuset_t cpu_suspend_map;
211 #endif
212 
213 	EVENTHANDLER_INVOKE(power_suspend_early);
214 	xs_lock();
215 	stop_all_proc();
216 	xs_unlock();
217 	suspend_all_fs();
218 	EVENTHANDLER_INVOKE(power_suspend);
219 
220 #ifdef EARLY_AP_STARTUP
221 	MPASS(mp_ncpus == 1 || smp_started);
222 	thread_lock(curthread);
223 	sched_bind(curthread, 0);
224 	thread_unlock(curthread);
225 #else
226 	if (smp_started) {
227 		thread_lock(curthread);
228 		sched_bind(curthread, 0);
229 		thread_unlock(curthread);
230 	}
231 #endif
232 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
233 
234 	/*
235 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME.
236 	 */
237 	bus_topo_lock();
238 	if (DEVICE_SUSPEND(root_bus) != 0) {
239 		bus_topo_unlock();
240 		printf("%s: device_suspend failed\n", __func__);
241 		return;
242 	}
243 
244 #ifdef SMP
245 #ifdef EARLY_AP_STARTUP
246 	/*
247 	 * Suspend other CPUs. This prevents IPIs while we
248 	 * are resuming, and will allow us to reset per-cpu
249 	 * vcpu_info on resume.
250 	 */
251 	cpu_suspend_map = all_cpus;
252 	CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
253 	if (!CPU_EMPTY(&cpu_suspend_map))
254 		suspend_cpus(cpu_suspend_map);
255 #else
256 	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
257 	if (smp_started) {
258 		/*
259 		 * Suspend other CPUs. This prevents IPIs while we
260 		 * are resuming, and will allow us to reset per-cpu
261 		 * vcpu_info on resume.
262 		 */
263 		cpu_suspend_map = all_cpus;
264 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
265 		if (!CPU_EMPTY(&cpu_suspend_map))
266 			suspend_cpus(cpu_suspend_map);
267 	}
268 #endif
269 #endif
270 
271 	/*
272 	 * Prevent any races with evtchn_interrupt() handler.
273 	 */
274 	disable_intr();
275 	intr_suspend();
276 	xen_hvm_suspend();
277 
278 	xen_suspend_cancelled = !!HYPERVISOR_suspend(0);
279 
280 	if (!xen_suspend_cancelled) {
281 		xen_hvm_resume(false);
282 	}
283 	intr_resume(xen_suspend_cancelled != 0);
284 	enable_intr();
285 
286 	/*
287 	 * Reset grant table info.
288 	 */
289 	if (!xen_suspend_cancelled) {
290 		gnttab_resume(NULL);
291 	}
292 
293 #ifdef SMP
294 	if (!CPU_EMPTY(&cpu_suspend_map)) {
295 		/*
296 		 * Now that event channels have been initialized,
297 		 * resume CPUs.
298 		 */
299 		resume_cpus(cpu_suspend_map);
300 #if defined(__amd64__) || defined(__i386__)
301 		/* Send an IPI_BITMAP in case there are pending bitmap IPIs. */
302 		lapic_ipi_vectored(IPI_BITMAP_VECTOR, APIC_IPI_DEST_ALL);
303 #endif
304 	}
305 #endif
306 
307 	/*
308 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
309 	 * similar.
310 	 */
311 	DEVICE_RESUME(root_bus);
312 	bus_topo_unlock();
313 
314 	/*
315 	 * Warm up timecounter again and reset system clock.
316 	 */
317 	timecounter->tc_get_timecount(timecounter);
318 	inittodr(time_second);
319 
320 #ifdef EARLY_AP_STARTUP
321 	thread_lock(curthread);
322 	sched_unbind(curthread);
323 	thread_unlock(curthread);
324 #else
325 	if (smp_started) {
326 		thread_lock(curthread);
327 		sched_unbind(curthread);
328 		thread_unlock(curthread);
329 	}
330 #endif
331 
332 	resume_all_fs();
333 	resume_all_proc();
334 
335 	EVENTHANDLER_INVOKE(power_resume);
336 
337 	if (bootverbose)
338 		printf("System resumed after suspension\n");
339 
340 }
341 #endif /* __amd64__ || __i386__ */
342 
343 static void
344 xctrl_crash()
345 {
346 	panic("Xen directed crash");
347 }
348 
349 static void
350 shutdown_final(void *arg, int howto)
351 {
352 	/* Inform the hypervisor that shutdown is complete. */
353 	if (howto & RB_POWEROFF)
354 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
355 	else if (howto & RB_POWERCYCLE)
356 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
357 }
358 
359 /*------------------------------ Event Reception -----------------------------*/
360 static void
361 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
362 {
363 	const struct xctrl_shutdown_reason *reason;
364 	const struct xctrl_shutdown_reason *last_reason;
365 	char *result;
366 	int   error;
367 	int   result_len;
368 
369 	error = xs_read(XST_NIL, "control", "shutdown",
370 			&result_len, (void **)&result);
371 	if (error != 0 || result_len == 0)
372 		return;
373 
374 	/* Acknowledge the request by writing back an empty string. */
375 	error = xs_write(XST_NIL, "control", "shutdown", "");
376 	if (error != 0)
377 		printf("unable to ack shutdown request, proceeding anyway\n");
378 
379 	reason = xctrl_shutdown_reasons;
380 	last_reason = reason + nitems(xctrl_shutdown_reasons);
381 	while (reason < last_reason) {
382 		if (!strcmp(result, reason->name)) {
383 			reason->handler();
384 			break;
385 		}
386 		reason++;
387 	}
388 
389 	free(result, M_XENSTORE);
390 }
391 
392 /*------------------ Private Device Attachment Functions  --------------------*/
393 /**
394  * \brief Identify instances of this device type in the system.
395  *
396  * \param driver  The driver performing this identify action.
397  * \param parent  The NewBus parent device for any devices this method adds.
398  */
399 static void
400 xctrl_identify(driver_t *driver __unused, device_t parent)
401 {
402 	/*
403 	 * A single device instance for our driver is always present
404 	 * in a system operating under Xen.
405 	 */
406 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
407 }
408 
409 /**
410  * \brief Probe for the existence of the Xen Control device
411  *
412  * \param dev  NewBus device_t for this Xen control instance.
413  *
414  * \return  Always returns 0 indicating success.
415  */
416 static int
417 xctrl_probe(device_t dev)
418 {
419 	device_set_desc(dev, "Xen Control Device");
420 
421 	return (BUS_PROBE_NOWILDCARD);
422 }
423 
424 /**
425  * \brief Attach the Xen control device.
426  *
427  * \param dev  NewBus device_t for this Xen control instance.
428  *
429  * \return  On success, 0. Otherwise an errno value indicating the
430  *          type of failure.
431  */
432 static int
433 xctrl_attach(device_t dev)
434 {
435 	struct xctrl_softc *xctrl;
436 
437 	xctrl = device_get_softc(dev);
438 
439 	/* Activate watch */
440 	xctrl->xctrl_watch.node = "control/shutdown";
441 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
442 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
443 	/*
444 	 * We don't care about the path updated, just about the value changes
445 	 * on that single node, hence there's no need to queue more that one
446 	 * event.
447 	 */
448 	xctrl->xctrl_watch.max_pending = 1;
449 	xs_register_watch(&xctrl->xctrl_watch);
450 
451 	EVENTHANDLER_REGISTER(shutdown_final, shutdown_final, NULL,
452 	    SHUTDOWN_PRI_LAST);
453 
454 	return (0);
455 }
456 
457 /**
458  * \brief Detach the Xen control device.
459  *
460  * \param dev  NewBus device_t for this Xen control device instance.
461  *
462  * \return  On success, 0. Otherwise an errno value indicating the
463  *          type of failure.
464  */
465 static int
466 xctrl_detach(device_t dev)
467 {
468 	struct xctrl_softc *xctrl;
469 
470 	xctrl = device_get_softc(dev);
471 
472 	/* Release watch */
473 	xs_unregister_watch(&xctrl->xctrl_watch);
474 
475 	return (0);
476 }
477 
478 /*-------------------- Private Device Attachment Data  -----------------------*/
479 static device_method_t xctrl_methods[] = {
480 	/* Device interface */
481 	DEVMETHOD(device_identify,	xctrl_identify),
482 	DEVMETHOD(device_probe,         xctrl_probe),
483 	DEVMETHOD(device_attach,        xctrl_attach),
484 	DEVMETHOD(device_detach,        xctrl_detach),
485 
486 	DEVMETHOD_END
487 };
488 
489 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
490 devclass_t xctrl_devclass;
491 
492 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
493