xref: /freebsd/sys/dev/xen/control/control.c (revision 3fc9e2c36555140de248a0b4def91bbfa44d7c2c)
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/intr_machdep.h>
132 
133 #include <vm/vm.h>
134 #include <vm/vm_extern.h>
135 #include <vm/vm_kern.h>
136 
137 #include <xen/xen-os.h>
138 #include <xen/blkif.h>
139 #include <xen/evtchn.h>
140 #include <xen/gnttab.h>
141 #include <xen/xen_intr.h>
142 
143 #include <xen/interface/event_channel.h>
144 #include <xen/interface/grant_table.h>
145 
146 #include <xen/xenbus/xenbusvar.h>
147 
148 #include <machine/xen/xenvar.h>
149 #include <machine/xen/xenfunc.h>
150 
151 /*--------------------------- Forward Declarations --------------------------*/
152 /** Function signature for shutdown event handlers. */
153 typedef	void (xctrl_shutdown_handler_t)(void);
154 
155 static xctrl_shutdown_handler_t xctrl_poweroff;
156 static xctrl_shutdown_handler_t xctrl_reboot;
157 static xctrl_shutdown_handler_t xctrl_suspend;
158 static xctrl_shutdown_handler_t xctrl_crash;
159 static xctrl_shutdown_handler_t xctrl_halt;
160 
161 /*-------------------------- Private Data Structures -------------------------*/
162 /** Element type for lookup table of event name to handler. */
163 struct xctrl_shutdown_reason {
164 	const char		 *name;
165 	xctrl_shutdown_handler_t *handler;
166 };
167 
168 /** Lookup table for shutdown event name to handler. */
169 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
170 	{ "poweroff", xctrl_poweroff },
171 	{ "reboot",   xctrl_reboot   },
172 	{ "suspend",  xctrl_suspend  },
173 	{ "crash",    xctrl_crash    },
174 	{ "halt",     xctrl_halt     },
175 };
176 
177 struct xctrl_softc {
178 	struct xs_watch    xctrl_watch;
179 };
180 
181 /*------------------------------ Event Handlers ------------------------------*/
182 static void
183 xctrl_poweroff()
184 {
185 	shutdown_nice(RB_POWEROFF|RB_HALT);
186 }
187 
188 static void
189 xctrl_reboot()
190 {
191 	shutdown_nice(0);
192 }
193 
194 #ifndef XENHVM
195 extern void xencons_suspend(void);
196 extern void xencons_resume(void);
197 
198 /* Full PV mode suspension. */
199 static void
200 xctrl_suspend()
201 {
202 	int i, j, k, fpp;
203 	unsigned long max_pfn, start_info_mfn;
204 
205 	EVENTHANDLER_INVOKE(power_suspend);
206 
207 #ifdef SMP
208 	struct thread *td;
209 	cpuset_t map;
210 	u_int cpuid;
211 
212 	/*
213 	 * Bind us to CPU 0 and stop any other VCPUs.
214 	 */
215 	td = curthread;
216 	thread_lock(td);
217 	sched_bind(td, 0);
218 	thread_unlock(td);
219 	cpuid = PCPU_GET(cpuid);
220 	KASSERT(cpuid == 0, ("xen_suspend: not running on cpu 0"));
221 
222 	map = all_cpus;
223 	CPU_CLR(cpuid, &map);
224 	CPU_NAND(&map, &stopped_cpus);
225 	if (!CPU_EMPTY(&map))
226 		stop_cpus(map);
227 #endif
228 
229 	/*
230 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
231 	 * drivers need this.
232 	 */
233 	mtx_lock(&Giant);
234 	if (DEVICE_SUSPEND(root_bus) != 0) {
235 		mtx_unlock(&Giant);
236 		printf("%s: device_suspend failed\n", __func__);
237 #ifdef SMP
238 		if (!CPU_EMPTY(&map))
239 			restart_cpus(map);
240 #endif
241 		return;
242 	}
243 	mtx_unlock(&Giant);
244 
245 	local_irq_disable();
246 
247 	xencons_suspend();
248 	gnttab_suspend();
249 	intr_suspend();
250 
251 	max_pfn = HYPERVISOR_shared_info->arch.max_pfn;
252 
253 	void *shared_info = HYPERVISOR_shared_info;
254 	HYPERVISOR_shared_info = NULL;
255 	pmap_kremove((vm_offset_t) shared_info);
256 	PT_UPDATES_FLUSH();
257 
258 	xen_start_info->store_mfn = MFNTOPFN(xen_start_info->store_mfn);
259 	xen_start_info->console.domU.mfn = MFNTOPFN(xen_start_info->console.domU.mfn);
260 
261 	/*
262 	 * We'll stop somewhere inside this hypercall. When it returns,
263 	 * we'll start resuming after the restore.
264 	 */
265 	start_info_mfn = VTOMFN(xen_start_info);
266 	pmap_suspend();
267 	HYPERVISOR_suspend(start_info_mfn);
268 	pmap_resume();
269 
270 	pmap_kenter_ma((vm_offset_t) shared_info, xen_start_info->shared_info);
271 	HYPERVISOR_shared_info = shared_info;
272 
273 	HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
274 		VTOMFN(xen_pfn_to_mfn_frame_list_list);
275 
276 	fpp = PAGE_SIZE/sizeof(unsigned long);
277 	for (i = 0, j = 0, k = -1; i < max_pfn; i += fpp, j++) {
278 		if ((j % fpp) == 0) {
279 			k++;
280 			xen_pfn_to_mfn_frame_list_list[k] =
281 				VTOMFN(xen_pfn_to_mfn_frame_list[k]);
282 			j = 0;
283 		}
284 		xen_pfn_to_mfn_frame_list[k][j] =
285 			VTOMFN(&xen_phys_machine[i]);
286 	}
287 	HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
288 
289 	gnttab_resume();
290 	intr_resume();
291 	local_irq_enable();
292 	xencons_resume();
293 
294 #ifdef CONFIG_SMP
295 	for_each_cpu(i)
296 		vcpu_prepare(i);
297 
298 #endif
299 
300 	/*
301 	 * Only resume xenbus /after/ we've prepared our VCPUs; otherwise
302 	 * the VCPU hotplug callback can race with our vcpu_prepare
303 	 */
304 	mtx_lock(&Giant);
305 	DEVICE_RESUME(root_bus);
306 	mtx_unlock(&Giant);
307 
308 #ifdef SMP
309 	thread_lock(curthread);
310 	sched_unbind(curthread);
311 	thread_unlock(curthread);
312 	if (!CPU_EMPTY(&map))
313 		restart_cpus(map);
314 #endif
315 	EVENTHANDLER_INVOKE(power_resume);
316 }
317 
318 static void
319 xen_pv_shutdown_final(void *arg, int howto)
320 {
321 	/*
322 	 * Inform the hypervisor that shutdown is complete.
323 	 * This is not necessary in HVM domains since Xen
324 	 * emulates ACPI in that mode and FreeBSD's ACPI
325 	 * support will request this transition.
326 	 */
327 	if (howto & (RB_HALT | RB_POWEROFF))
328 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
329 	else
330 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
331 }
332 
333 #else
334 extern void xenpci_resume(void);
335 
336 /* HVM mode suspension. */
337 static void
338 xctrl_suspend()
339 {
340 	int suspend_cancelled;
341 
342 	EVENTHANDLER_INVOKE(power_suspend);
343 
344 	/*
345 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
346 	 * drivers need this.
347 	 */
348 	mtx_lock(&Giant);
349 	if (DEVICE_SUSPEND(root_bus) != 0) {
350 		mtx_unlock(&Giant);
351 		printf("%s: device_suspend failed\n", __func__);
352 		return;
353 	}
354 	mtx_unlock(&Giant);
355 
356 	/*
357 	 * Prevent any races with evtchn_interrupt() handler.
358 	 */
359 	disable_intr();
360 	intr_suspend();
361 
362 	suspend_cancelled = HYPERVISOR_suspend(0);
363 
364 	intr_resume();
365 
366 	/*
367 	 * Re-enable interrupts and put the scheduler back to normal.
368 	 */
369 	enable_intr();
370 
371 	/*
372 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
373 	 * similar.
374 	 */
375 	mtx_lock(&Giant);
376 	if (!suspend_cancelled)
377 		DEVICE_RESUME(root_bus);
378 	mtx_unlock(&Giant);
379 
380 	EVENTHANDLER_INVOKE(power_resume);
381 }
382 #endif
383 
384 static void
385 xctrl_crash()
386 {
387 	panic("Xen directed crash");
388 }
389 
390 static void
391 xctrl_halt()
392 {
393 	shutdown_nice(RB_HALT);
394 }
395 
396 /*------------------------------ Event Reception -----------------------------*/
397 static void
398 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
399 {
400 	const struct xctrl_shutdown_reason *reason;
401 	const struct xctrl_shutdown_reason *last_reason;
402 	char *result;
403 	int   error;
404 	int   result_len;
405 
406 	error = xs_read(XST_NIL, "control", "shutdown",
407 			&result_len, (void **)&result);
408 	if (error != 0)
409 		return;
410 
411 	reason = xctrl_shutdown_reasons;
412 	last_reason = reason + nitems(xctrl_shutdown_reasons);
413 	while (reason < last_reason) {
414 
415 		if (!strcmp(result, reason->name)) {
416 			reason->handler();
417 			break;
418 		}
419 		reason++;
420 	}
421 
422 	free(result, M_XENSTORE);
423 }
424 
425 /*------------------ Private Device Attachment Functions  --------------------*/
426 /**
427  * \brief Identify instances of this device type in the system.
428  *
429  * \param driver  The driver performing this identify action.
430  * \param parent  The NewBus parent device for any devices this method adds.
431  */
432 static void
433 xctrl_identify(driver_t *driver __unused, device_t parent)
434 {
435 	/*
436 	 * A single device instance for our driver is always present
437 	 * in a system operating under Xen.
438 	 */
439 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
440 }
441 
442 /**
443  * \brief Probe for the existance of the Xen Control device
444  *
445  * \param dev  NewBus device_t for this Xen control instance.
446  *
447  * \return  Always returns 0 indicating success.
448  */
449 static int
450 xctrl_probe(device_t dev)
451 {
452 	device_set_desc(dev, "Xen Control Device");
453 
454 	return (0);
455 }
456 
457 /**
458  * \brief Attach the Xen control device.
459  *
460  * \param dev  NewBus device_t for this Xen control instance.
461  *
462  * \return  On success, 0. Otherwise an errno value indicating the
463  *          type of failure.
464  */
465 static int
466 xctrl_attach(device_t dev)
467 {
468 	struct xctrl_softc *xctrl;
469 
470 	xctrl = device_get_softc(dev);
471 
472 	/* Activate watch */
473 	xctrl->xctrl_watch.node = "control/shutdown";
474 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
475 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
476 	xs_register_watch(&xctrl->xctrl_watch);
477 
478 #ifndef XENHVM
479 	EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
480 			      SHUTDOWN_PRI_LAST);
481 #endif
482 
483 	return (0);
484 }
485 
486 /**
487  * \brief Detach the Xen control device.
488  *
489  * \param dev  NewBus device_t for this Xen control device instance.
490  *
491  * \return  On success, 0. Otherwise an errno value indicating the
492  *          type of failure.
493  */
494 static int
495 xctrl_detach(device_t dev)
496 {
497 	struct xctrl_softc *xctrl;
498 
499 	xctrl = device_get_softc(dev);
500 
501 	/* Release watch */
502 	xs_unregister_watch(&xctrl->xctrl_watch);
503 
504 	return (0);
505 }
506 
507 /*-------------------- Private Device Attachment Data  -----------------------*/
508 static device_method_t xctrl_methods[] = {
509 	/* Device interface */
510 	DEVMETHOD(device_identify,	xctrl_identify),
511 	DEVMETHOD(device_probe,         xctrl_probe),
512 	DEVMETHOD(device_attach,        xctrl_attach),
513 	DEVMETHOD(device_detach,        xctrl_detach),
514 
515 	DEVMETHOD_END
516 };
517 
518 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
519 devclass_t xctrl_devclass;
520 
521 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
522