xref: /freebsd/sys/dev/xen/control/control.c (revision ce3adf4362fcca6a43e500b2531f0038adbfbd21)
1 /*-
2  * Copyright (c) 2010 Justin T. Gibbs, Spectra Logic Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    substantially similar to the "NO WARRANTY" disclaimer below
13  *    ("Disclaimer") and any redistribution must be conditioned upon
14  *    including a substantially similar Disclaimer requirement for further
15  *    binary redistribution.
16  *
17  * NO WARRANTY
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGES.
29  */
30 
31 /*-
32  * PV suspend/resume support:
33  *
34  * Copyright (c) 2004 Christian Limpach.
35  * Copyright (c) 2004-2006,2008 Kip Macy
36  * All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *      This product includes software developed by Christian Limpach.
49  * 4. The name of the author may not be used to endorse or promote products
50  *    derived from this software without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
53  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
54  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
55  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
56  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
57  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
58  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
59  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
60  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
61  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
62  */
63 
64 /*-
65  * HVM suspend/resume support:
66  *
67  * Copyright (c) 2008 Citrix Systems, Inc.
68  * All rights reserved.
69  *
70  * Redistribution and use in source and binary forms, with or without
71  * modification, are permitted provided that the following conditions
72  * are met:
73  * 1. Redistributions of source code must retain the above copyright
74  *    notice, this list of conditions and the following disclaimer.
75  * 2. Redistributions in binary form must reproduce the above copyright
76  *    notice, this list of conditions and the following disclaimer in the
77  *    documentation and/or other materials provided with the distribution.
78  *
79  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
80  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
81  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
82  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
83  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
84  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
85  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
86  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
87  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
88  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
89  * SUCH DAMAGE.
90  */
91 #include <sys/cdefs.h>
92 __FBSDID("$FreeBSD$");
93 
94 /**
95  * \file control.c
96  *
97  * \brief Device driver to repond to control domain events that impact
98  *        this VM.
99  */
100 
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/kernel.h>
104 #include <sys/malloc.h>
105 
106 #include <sys/bio.h>
107 #include <sys/bus.h>
108 #include <sys/conf.h>
109 #include <sys/disk.h>
110 #include <sys/fcntl.h>
111 #include <sys/filedesc.h>
112 #include <sys/kdb.h>
113 #include <sys/module.h>
114 #include <sys/namei.h>
115 #include <sys/proc.h>
116 #include <sys/reboot.h>
117 #include <sys/rman.h>
118 #include <sys/sched.h>
119 #include <sys/taskqueue.h>
120 #include <sys/types.h>
121 #include <sys/vnode.h>
122 #include <sys/sched.h>
123 #include <sys/smp.h>
124 #include <sys/eventhandler.h>
125 
126 #include <geom/geom.h>
127 
128 #include <machine/_inttypes.h>
129 #include <machine/intr_machdep.h>
130 
131 #include <vm/vm.h>
132 #include <vm/vm_extern.h>
133 #include <vm/vm_kern.h>
134 
135 #include <xen/xen-os.h>
136 #include <xen/blkif.h>
137 #include <xen/evtchn.h>
138 #include <xen/gnttab.h>
139 #include <xen/xen_intr.h>
140 
141 #ifdef XENHVM
142 #include <xen/hvm.h>
143 #endif
144 
145 #include <xen/interface/event_channel.h>
146 #include <xen/interface/grant_table.h>
147 
148 #include <xen/xenbus/xenbusvar.h>
149 
150 #include <machine/xen/xenvar.h>
151 #include <machine/xen/xenfunc.h>
152 
153 /*--------------------------- Forward Declarations --------------------------*/
154 /** Function signature for shutdown event handlers. */
155 typedef	void (xctrl_shutdown_handler_t)(void);
156 
157 static xctrl_shutdown_handler_t xctrl_poweroff;
158 static xctrl_shutdown_handler_t xctrl_reboot;
159 static xctrl_shutdown_handler_t xctrl_suspend;
160 static xctrl_shutdown_handler_t xctrl_crash;
161 static xctrl_shutdown_handler_t xctrl_halt;
162 
163 /*-------------------------- Private Data Structures -------------------------*/
164 /** Element type for lookup table of event name to handler. */
165 struct xctrl_shutdown_reason {
166 	const char		 *name;
167 	xctrl_shutdown_handler_t *handler;
168 };
169 
170 /** Lookup table for shutdown event name to handler. */
171 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
172 	{ "poweroff", xctrl_poweroff },
173 	{ "reboot",   xctrl_reboot   },
174 	{ "suspend",  xctrl_suspend  },
175 	{ "crash",    xctrl_crash    },
176 	{ "halt",     xctrl_halt     },
177 };
178 
179 struct xctrl_softc {
180 	struct xs_watch    xctrl_watch;
181 };
182 
183 /*------------------------------ Event Handlers ------------------------------*/
184 static void
185 xctrl_poweroff()
186 {
187 	shutdown_nice(RB_POWEROFF|RB_HALT);
188 }
189 
190 static void
191 xctrl_reboot()
192 {
193 	shutdown_nice(0);
194 }
195 
196 #ifndef XENHVM
197 extern void xencons_suspend(void);
198 extern void xencons_resume(void);
199 
200 /* Full PV mode suspension. */
201 static void
202 xctrl_suspend()
203 {
204 	int i, j, k, fpp, suspend_cancelled;
205 	unsigned long max_pfn, start_info_mfn;
206 
207 	EVENTHANDLER_INVOKE(power_suspend);
208 
209 #ifdef SMP
210 	struct thread *td;
211 	cpuset_t map;
212 	u_int cpuid;
213 
214 	/*
215 	 * Bind us to CPU 0 and stop any other VCPUs.
216 	 */
217 	td = curthread;
218 	thread_lock(td);
219 	sched_bind(td, 0);
220 	thread_unlock(td);
221 	cpuid = PCPU_GET(cpuid);
222 	KASSERT(cpuid == 0, ("xen_suspend: not running on cpu 0"));
223 
224 	map = all_cpus;
225 	CPU_CLR(cpuid, &map);
226 	CPU_NAND(&map, &stopped_cpus);
227 	if (!CPU_EMPTY(&map))
228 		stop_cpus(map);
229 #endif
230 
231 	/*
232 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
233 	 * drivers need this.
234 	 */
235 	mtx_lock(&Giant);
236 	if (DEVICE_SUSPEND(root_bus) != 0) {
237 		mtx_unlock(&Giant);
238 		printf("%s: device_suspend failed\n", __func__);
239 #ifdef SMP
240 		if (!CPU_EMPTY(&map))
241 			restart_cpus(map);
242 #endif
243 		return;
244 	}
245 	mtx_unlock(&Giant);
246 
247 	local_irq_disable();
248 
249 	xencons_suspend();
250 	gnttab_suspend();
251 	intr_suspend();
252 
253 	max_pfn = HYPERVISOR_shared_info->arch.max_pfn;
254 
255 	void *shared_info = HYPERVISOR_shared_info;
256 	HYPERVISOR_shared_info = NULL;
257 	pmap_kremove((vm_offset_t) shared_info);
258 	PT_UPDATES_FLUSH();
259 
260 	xen_start_info->store_mfn = MFNTOPFN(xen_start_info->store_mfn);
261 	xen_start_info->console.domU.mfn = MFNTOPFN(xen_start_info->console.domU.mfn);
262 
263 	/*
264 	 * We'll stop somewhere inside this hypercall. When it returns,
265 	 * we'll start resuming after the restore.
266 	 */
267 	start_info_mfn = VTOMFN(xen_start_info);
268 	pmap_suspend();
269 	suspend_cancelled = HYPERVISOR_suspend(start_info_mfn);
270 	pmap_resume();
271 
272 	pmap_kenter_ma((vm_offset_t) shared_info, xen_start_info->shared_info);
273 	HYPERVISOR_shared_info = shared_info;
274 
275 	HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
276 		VTOMFN(xen_pfn_to_mfn_frame_list_list);
277 
278 	fpp = PAGE_SIZE/sizeof(unsigned long);
279 	for (i = 0, j = 0, k = -1; i < max_pfn; i += fpp, j++) {
280 		if ((j % fpp) == 0) {
281 			k++;
282 			xen_pfn_to_mfn_frame_list_list[k] =
283 				VTOMFN(xen_pfn_to_mfn_frame_list[k]);
284 			j = 0;
285 		}
286 		xen_pfn_to_mfn_frame_list[k][j] =
287 			VTOMFN(&xen_phys_machine[i]);
288 	}
289 	HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
290 
291 	gnttab_resume();
292 	intr_resume(suspend_cancelled != 0);
293 	local_irq_enable();
294 	xencons_resume();
295 
296 #ifdef CONFIG_SMP
297 	for_each_cpu(i)
298 		vcpu_prepare(i);
299 
300 #endif
301 
302 	/*
303 	 * Only resume xenbus /after/ we've prepared our VCPUs; otherwise
304 	 * the VCPU hotplug callback can race with our vcpu_prepare
305 	 */
306 	mtx_lock(&Giant);
307 	DEVICE_RESUME(root_bus);
308 	mtx_unlock(&Giant);
309 
310 #ifdef SMP
311 	thread_lock(curthread);
312 	sched_unbind(curthread);
313 	thread_unlock(curthread);
314 	if (!CPU_EMPTY(&map))
315 		restart_cpus(map);
316 #endif
317 	EVENTHANDLER_INVOKE(power_resume);
318 }
319 
320 static void
321 xen_pv_shutdown_final(void *arg, int howto)
322 {
323 	/*
324 	 * Inform the hypervisor that shutdown is complete.
325 	 * This is not necessary in HVM domains since Xen
326 	 * emulates ACPI in that mode and FreeBSD's ACPI
327 	 * support will request this transition.
328 	 */
329 	if (howto & (RB_HALT | RB_POWEROFF))
330 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
331 	else
332 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
333 }
334 
335 #else
336 
337 /* HVM mode suspension. */
338 static void
339 xctrl_suspend()
340 {
341 #ifdef SMP
342 	cpuset_t cpu_suspend_map;
343 #endif
344 	int suspend_cancelled;
345 
346 	EVENTHANDLER_INVOKE(power_suspend);
347 
348 	if (smp_started) {
349 		thread_lock(curthread);
350 		sched_bind(curthread, 0);
351 		thread_unlock(curthread);
352 	}
353 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
354 
355 	/*
356 	 * Clear our XenStore node so the toolstack knows we are
357 	 * responding to the suspend request.
358 	 */
359 	xs_write(XST_NIL, "control", "shutdown", "");
360 
361 	/*
362 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
363 	 * drivers need this.
364 	 */
365 	mtx_lock(&Giant);
366 	if (DEVICE_SUSPEND(root_bus) != 0) {
367 		mtx_unlock(&Giant);
368 		printf("%s: device_suspend failed\n", __func__);
369 		return;
370 	}
371 	mtx_unlock(&Giant);
372 
373 #ifdef SMP
374 	if (smp_started) {
375 		/*
376 		 * Suspend other CPUs. This prevents IPIs while we
377 		 * are resuming, and will allow us to reset per-cpu
378 		 * vcpu_info on resume.
379 		 */
380 		cpu_suspend_map = all_cpus;
381 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
382 		if (!CPU_EMPTY(&cpu_suspend_map))
383 			suspend_cpus(cpu_suspend_map);
384 	}
385 #endif
386 
387 	/*
388 	 * Prevent any races with evtchn_interrupt() handler.
389 	 */
390 	disable_intr();
391 	intr_suspend();
392 	xen_hvm_suspend();
393 
394 	suspend_cancelled = HYPERVISOR_suspend(0);
395 
396 	xen_hvm_resume(suspend_cancelled != 0);
397 	intr_resume(suspend_cancelled != 0);
398 	enable_intr();
399 
400 	/*
401 	 * Reset grant table info.
402 	 */
403 	gnttab_resume();
404 
405 #ifdef SMP
406 	if (smp_started && !CPU_EMPTY(&cpu_suspend_map)) {
407 		/*
408 		 * Now that event channels have been initialized,
409 		 * resume CPUs.
410 		 */
411 		resume_cpus(cpu_suspend_map);
412 	}
413 #endif
414 
415 	/*
416 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
417 	 * similar.
418 	 */
419 	mtx_lock(&Giant);
420 	DEVICE_RESUME(root_bus);
421 	mtx_unlock(&Giant);
422 
423 	if (smp_started) {
424 		thread_lock(curthread);
425 		sched_unbind(curthread);
426 		thread_unlock(curthread);
427 	}
428 
429 	EVENTHANDLER_INVOKE(power_resume);
430 
431 	if (bootverbose)
432 		printf("System resumed after suspension\n");
433 
434 }
435 #endif
436 
437 static void
438 xctrl_crash()
439 {
440 	panic("Xen directed crash");
441 }
442 
443 static void
444 xctrl_halt()
445 {
446 	shutdown_nice(RB_HALT);
447 }
448 
449 /*------------------------------ Event Reception -----------------------------*/
450 static void
451 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
452 {
453 	const struct xctrl_shutdown_reason *reason;
454 	const struct xctrl_shutdown_reason *last_reason;
455 	char *result;
456 	int   error;
457 	int   result_len;
458 
459 	error = xs_read(XST_NIL, "control", "shutdown",
460 			&result_len, (void **)&result);
461 	if (error != 0)
462 		return;
463 
464 	reason = xctrl_shutdown_reasons;
465 	last_reason = reason + nitems(xctrl_shutdown_reasons);
466 	while (reason < last_reason) {
467 
468 		if (!strcmp(result, reason->name)) {
469 			reason->handler();
470 			break;
471 		}
472 		reason++;
473 	}
474 
475 	free(result, M_XENSTORE);
476 }
477 
478 /*------------------ Private Device Attachment Functions  --------------------*/
479 /**
480  * \brief Identify instances of this device type in the system.
481  *
482  * \param driver  The driver performing this identify action.
483  * \param parent  The NewBus parent device for any devices this method adds.
484  */
485 static void
486 xctrl_identify(driver_t *driver __unused, device_t parent)
487 {
488 	/*
489 	 * A single device instance for our driver is always present
490 	 * in a system operating under Xen.
491 	 */
492 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
493 }
494 
495 /**
496  * \brief Probe for the existance of the Xen Control device
497  *
498  * \param dev  NewBus device_t for this Xen control instance.
499  *
500  * \return  Always returns 0 indicating success.
501  */
502 static int
503 xctrl_probe(device_t dev)
504 {
505 	device_set_desc(dev, "Xen Control Device");
506 
507 	return (0);
508 }
509 
510 /**
511  * \brief Attach the Xen control device.
512  *
513  * \param dev  NewBus device_t for this Xen control instance.
514  *
515  * \return  On success, 0. Otherwise an errno value indicating the
516  *          type of failure.
517  */
518 static int
519 xctrl_attach(device_t dev)
520 {
521 	struct xctrl_softc *xctrl;
522 
523 	xctrl = device_get_softc(dev);
524 
525 	/* Activate watch */
526 	xctrl->xctrl_watch.node = "control/shutdown";
527 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
528 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
529 	xs_register_watch(&xctrl->xctrl_watch);
530 
531 #ifndef XENHVM
532 	EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
533 			      SHUTDOWN_PRI_LAST);
534 #endif
535 
536 	return (0);
537 }
538 
539 /**
540  * \brief Detach the Xen control device.
541  *
542  * \param dev  NewBus device_t for this Xen control device instance.
543  *
544  * \return  On success, 0. Otherwise an errno value indicating the
545  *          type of failure.
546  */
547 static int
548 xctrl_detach(device_t dev)
549 {
550 	struct xctrl_softc *xctrl;
551 
552 	xctrl = device_get_softc(dev);
553 
554 	/* Release watch */
555 	xs_unregister_watch(&xctrl->xctrl_watch);
556 
557 	return (0);
558 }
559 
560 /*-------------------- Private Device Attachment Data  -----------------------*/
561 static device_method_t xctrl_methods[] = {
562 	/* Device interface */
563 	DEVMETHOD(device_identify,	xctrl_identify),
564 	DEVMETHOD(device_probe,         xctrl_probe),
565 	DEVMETHOD(device_attach,        xctrl_attach),
566 	DEVMETHOD(device_detach,        xctrl_detach),
567 
568 	DEVMETHOD_END
569 };
570 
571 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
572 devclass_t xctrl_devclass;
573 
574 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
575