xref: /freebsd/sys/dev/xen/control/control.c (revision 3c91c65a2b999a8d27e99bcc6493de7cf812c948)
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 
123 #ifndef XENHVM
124 #include <sys/sched.h>
125 #include <sys/smp.h>
126 #endif
127 
128 #include <geom/geom.h>
129 
130 #include <machine/_inttypes.h>
131 #include <machine/xen/xen-os.h>
132 
133 #include <vm/vm.h>
134 #include <vm/vm_extern.h>
135 #include <vm/vm_kern.h>
136 
137 #include <xen/blkif.h>
138 #include <xen/evtchn.h>
139 #include <xen/gnttab.h>
140 #include <xen/xen_intr.h>
141 
142 #include <xen/interface/event_channel.h>
143 #include <xen/interface/grant_table.h>
144 
145 #include <xen/xenbus/xenbusvar.h>
146 
147 /*--------------------------- Forward Declarations --------------------------*/
148 /** Function signature for shutdown event handlers. */
149 typedef	void (xctrl_shutdown_handler_t)(void);
150 
151 static xctrl_shutdown_handler_t xctrl_poweroff;
152 static xctrl_shutdown_handler_t xctrl_reboot;
153 static xctrl_shutdown_handler_t xctrl_suspend;
154 static xctrl_shutdown_handler_t xctrl_crash;
155 static xctrl_shutdown_handler_t xctrl_halt;
156 
157 /*-------------------------- Private Data Structures -------------------------*/
158 /** Element type for lookup table of event name to handler. */
159 struct xctrl_shutdown_reason {
160 	const char		 *name;
161 	xctrl_shutdown_handler_t *handler;
162 };
163 
164 /** Lookup table for shutdown event name to handler. */
165 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
166 	{ "poweroff", xctrl_poweroff },
167 	{ "reboot",   xctrl_reboot   },
168 	{ "suspend",  xctrl_suspend  },
169 	{ "crash",    xctrl_crash    },
170 	{ "halt",     xctrl_halt     },
171 };
172 
173 struct xctrl_softc {
174 	struct xs_watch    xctrl_watch;
175 };
176 
177 /*------------------------------ Event Handlers ------------------------------*/
178 static void
179 xctrl_poweroff()
180 {
181 	shutdown_nice(RB_POWEROFF|RB_HALT);
182 }
183 
184 static void
185 xctrl_reboot()
186 {
187 	shutdown_nice(0);
188 }
189 
190 #ifndef XENHVM
191 extern void xencons_suspend(void);
192 extern void xencons_resume(void);
193 
194 /* Full PV mode suspension. */
195 static void
196 xctrl_suspend()
197 {
198 	int i, j, k, fpp;
199 	unsigned long max_pfn, start_info_mfn;
200 
201 	EVENTHANDLER_INVOKE(power_suspend);
202 
203 #ifdef SMP
204 	struct thread *td;
205 	cpuset_t map;
206 	u_int cpuid;
207 
208 	/*
209 	 * Bind us to CPU 0 and stop any other VCPUs.
210 	 */
211 	td = curthread;
212 	thread_lock(td);
213 	sched_bind(td, 0);
214 	thread_unlock(td);
215 	cpuid = PCPU_GET(cpuid);
216 	KASSERT(cpuid == 0, ("xen_suspend: not running on cpu 0"));
217 
218 	map = all_cpus;
219 	CPU_CLR(cpuid, &map);
220 	CPU_NAND(&map, &stopped_cpus);
221 	if (!CPU_EMPTY(&map))
222 		stop_cpus(map);
223 #endif
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 #ifdef SMP
234 		if (!CPU_EMPTY(&map))
235 			restart_cpus(map);
236 #endif
237 		return;
238 	}
239 	mtx_unlock(&Giant);
240 
241 	local_irq_disable();
242 
243 	xencons_suspend();
244 	gnttab_suspend();
245 
246 	max_pfn = HYPERVISOR_shared_info->arch.max_pfn;
247 
248 	void *shared_info = HYPERVISOR_shared_info;
249 	HYPERVISOR_shared_info = NULL;
250 	pmap_kremove((vm_offset_t) shared_info);
251 	PT_UPDATES_FLUSH();
252 
253 	xen_start_info->store_mfn = MFNTOPFN(xen_start_info->store_mfn);
254 	xen_start_info->console.domU.mfn = MFNTOPFN(xen_start_info->console.domU.mfn);
255 
256 	/*
257 	 * We'll stop somewhere inside this hypercall. When it returns,
258 	 * we'll start resuming after the restore.
259 	 */
260 	start_info_mfn = VTOMFN(xen_start_info);
261 	pmap_suspend();
262 	HYPERVISOR_suspend(start_info_mfn);
263 	pmap_resume();
264 
265 	pmap_kenter_ma((vm_offset_t) shared_info, xen_start_info->shared_info);
266 	HYPERVISOR_shared_info = shared_info;
267 
268 	HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
269 		VTOMFN(xen_pfn_to_mfn_frame_list_list);
270 
271 	fpp = PAGE_SIZE/sizeof(unsigned long);
272 	for (i = 0, j = 0, k = -1; i < max_pfn; i += fpp, j++) {
273 		if ((j % fpp) == 0) {
274 			k++;
275 			xen_pfn_to_mfn_frame_list_list[k] =
276 				VTOMFN(xen_pfn_to_mfn_frame_list[k]);
277 			j = 0;
278 		}
279 		xen_pfn_to_mfn_frame_list[k][j] =
280 			VTOMFN(&xen_phys_machine[i]);
281 	}
282 	HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
283 
284 	gnttab_resume();
285 	irq_resume();
286 	local_irq_enable();
287 	xencons_resume();
288 
289 #ifdef CONFIG_SMP
290 	for_each_cpu(i)
291 		vcpu_prepare(i);
292 
293 #endif
294 
295 	/*
296 	 * Only resume xenbus /after/ we've prepared our VCPUs; otherwise
297 	 * the VCPU hotplug callback can race with our vcpu_prepare
298 	 */
299 	mtx_lock(&Giant);
300 	DEVICE_RESUME(root_bus);
301 	mtx_unlock(&Giant);
302 
303 #ifdef SMP
304 	thread_lock(curthread);
305 	sched_unbind(curthread);
306 	thread_unlock(curthread);
307 	if (!CPU_EMPTY(&map))
308 		restart_cpus(map);
309 #endif
310 	EVENTHANDLER_INVOKE(power_resume);
311 }
312 
313 static void
314 xen_pv_shutdown_final(void *arg, int howto)
315 {
316 	/*
317 	 * Inform the hypervisor that shutdown is complete.
318 	 * This is not necessary in HVM domains since Xen
319 	 * emulates ACPI in that mode and FreeBSD's ACPI
320 	 * support will request this transition.
321 	 */
322 	if (howto & (RB_HALT | RB_POWEROFF))
323 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
324 	else
325 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
326 }
327 
328 #else
329 extern void xenpci_resume(void);
330 
331 /* HVM mode suspension. */
332 static void
333 xctrl_suspend()
334 {
335 	int suspend_cancelled;
336 
337 	EVENTHANDLER_INVOKE(power_suspend);
338 
339 	/*
340 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
341 	 * drivers need this.
342 	 */
343 	mtx_lock(&Giant);
344 	if (DEVICE_SUSPEND(root_bus) != 0) {
345 		mtx_unlock(&Giant);
346 		printf("%s: device_suspend failed\n", __func__);
347 		return;
348 	}
349 	mtx_unlock(&Giant);
350 
351 	/*
352 	 * Prevent any races with evtchn_interrupt() handler.
353 	 */
354 	disable_intr();
355 	irq_suspend();
356 
357 	suspend_cancelled = HYPERVISOR_suspend(0);
358 	if (suspend_cancelled)
359 		irq_resume();
360 	else
361 		xenpci_resume();
362 
363 	/*
364 	 * Re-enable interrupts and put the scheduler back to normal.
365 	 */
366 	enable_intr();
367 
368 	/*
369 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
370 	 * similar.
371 	 */
372 	mtx_lock(&Giant);
373 	if (!suspend_cancelled)
374 		DEVICE_RESUME(root_bus);
375 	mtx_unlock(&Giant);
376 
377 	EVENTHANDLER_INVOKE(power_resume);
378 }
379 #endif
380 
381 static void
382 xctrl_crash()
383 {
384 	panic("Xen directed crash");
385 }
386 
387 static void
388 xctrl_halt()
389 {
390 	shutdown_nice(RB_HALT);
391 }
392 
393 /*------------------------------ Event Reception -----------------------------*/
394 static void
395 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
396 {
397 	const struct xctrl_shutdown_reason *reason;
398 	const struct xctrl_shutdown_reason *last_reason;
399 	char *result;
400 	int   error;
401 	int   result_len;
402 
403 	error = xs_read(XST_NIL, "control", "shutdown",
404 			&result_len, (void **)&result);
405 	if (error != 0)
406 		return;
407 
408 	reason = xctrl_shutdown_reasons;
409 	last_reason = reason + nitems(xctrl_shutdown_reasons);
410 	while (reason < last_reason) {
411 
412 		if (!strcmp(result, reason->name)) {
413 			reason->handler();
414 			break;
415 		}
416 		reason++;
417 	}
418 
419 	free(result, M_XENSTORE);
420 }
421 
422 /*------------------ Private Device Attachment Functions  --------------------*/
423 /**
424  * \brief Identify instances of this device type in the system.
425  *
426  * \param driver  The driver performing this identify action.
427  * \param parent  The NewBus parent device for any devices this method adds.
428  */
429 static void
430 xctrl_identify(driver_t *driver __unused, device_t parent)
431 {
432 	/*
433 	 * A single device instance for our driver is always present
434 	 * in a system operating under Xen.
435 	 */
436 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
437 }
438 
439 /**
440  * \brief Probe for the existance of the Xen Control device
441  *
442  * \param dev  NewBus device_t for this Xen control instance.
443  *
444  * \return  Always returns 0 indicating success.
445  */
446 static int
447 xctrl_probe(device_t dev)
448 {
449 	device_set_desc(dev, "Xen Control Device");
450 
451 	return (0);
452 }
453 
454 /**
455  * \brief Attach the Xen control device.
456  *
457  * \param dev  NewBus device_t for this Xen control instance.
458  *
459  * \return  On success, 0. Otherwise an errno value indicating the
460  *          type of failure.
461  */
462 static int
463 xctrl_attach(device_t dev)
464 {
465 	struct xctrl_softc *xctrl;
466 
467 	xctrl = device_get_softc(dev);
468 
469 	/* Activate watch */
470 	xctrl->xctrl_watch.node = "control/shutdown";
471 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
472 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
473 	xs_register_watch(&xctrl->xctrl_watch);
474 
475 #ifndef XENHVM
476 	EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
477 			      SHUTDOWN_PRI_LAST);
478 #endif
479 
480 	return (0);
481 }
482 
483 /**
484  * \brief Detach the Xen control device.
485  *
486  * \param dev  NewBus device_t for this Xen control device instance.
487  *
488  * \return  On success, 0. Otherwise an errno value indicating the
489  *          type of failure.
490  */
491 static int
492 xctrl_detach(device_t dev)
493 {
494 	struct xctrl_softc *xctrl;
495 
496 	xctrl = device_get_softc(dev);
497 
498 	/* Release watch */
499 	xs_unregister_watch(&xctrl->xctrl_watch);
500 
501 	return (0);
502 }
503 
504 /*-------------------- Private Device Attachment Data  -----------------------*/
505 static device_method_t xctrl_methods[] = {
506 	/* Device interface */
507 	DEVMETHOD(device_identify,	xctrl_identify),
508 	DEVMETHOD(device_probe,         xctrl_probe),
509 	DEVMETHOD(device_attach,        xctrl_attach),
510 	DEVMETHOD(device_detach,        xctrl_detach),
511 
512 	DEVMETHOD_END
513 };
514 
515 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
516 devclass_t xctrl_devclass;
517 
518 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
519