xref: /freebsd/sys/dev/xen/control/control.c (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992)
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/taskqueue.h>
119 #include <sys/types.h>
120 #include <sys/vnode.h>
121 
122 #ifndef XENHVM
123 #include <sys/sched.h>
124 #include <sys/smp.h>
125 #endif
126 
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 #define NUM_ELEMENTS(x) (sizeof(x) / sizeof(*(x)))
148 
149 /*--------------------------- Forward Declarations --------------------------*/
150 /** Function signature for shutdown event handlers. */
151 typedef	void (xctrl_shutdown_handler_t)(void);
152 
153 static xctrl_shutdown_handler_t xctrl_poweroff;
154 static xctrl_shutdown_handler_t xctrl_reboot;
155 static xctrl_shutdown_handler_t xctrl_suspend;
156 static xctrl_shutdown_handler_t xctrl_crash;
157 static xctrl_shutdown_handler_t xctrl_halt;
158 
159 /*-------------------------- Private Data Structures -------------------------*/
160 /** Element type for lookup table of event name to handler. */
161 struct xctrl_shutdown_reason {
162 	const char		 *name;
163 	xctrl_shutdown_handler_t *handler;
164 };
165 
166 /** Lookup table for shutdown event name to handler. */
167 static struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
168 	{ "poweroff", xctrl_poweroff },
169 	{ "reboot",   xctrl_reboot   },
170 	{ "suspend",  xctrl_suspend  },
171 	{ "crash",    xctrl_crash    },
172 	{ "halt",     xctrl_halt     },
173 };
174 
175 struct xctrl_softc {
176 
177 	/** Must be first */
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 #ifdef SMP
206 	cpumask_t map;
207 	/*
208 	 * Bind us to CPU 0 and stop any other VCPUs.
209 	 */
210 	thread_lock(curthread);
211 	sched_bind(curthread, 0);
212 	thread_unlock(curthread);
213 	KASSERT(PCPU_GET(cpuid) == 0, ("xen_suspend: not running on cpu 0"));
214 
215 	map = PCPU_GET(other_cpus) & ~stopped_cpus;
216 	if (map)
217 		stop_cpus(map);
218 #endif
219 
220 	if (DEVICE_SUSPEND(root_bus) != 0) {
221 		printf("xen_suspend: device_suspend failed\n");
222 #ifdef SMP
223 		if (map)
224 			restart_cpus(map);
225 #endif
226 		return;
227 	}
228 
229 	local_irq_disable();
230 
231 	xencons_suspend();
232 	gnttab_suspend();
233 
234 	max_pfn = HYPERVISOR_shared_info->arch.max_pfn;
235 
236 	void *shared_info = HYPERVISOR_shared_info;
237 	HYPERVISOR_shared_info = NULL;
238 	pmap_kremove((vm_offset_t) shared_info);
239 	PT_UPDATES_FLUSH();
240 
241 	xen_start_info->store_mfn = MFNTOPFN(xen_start_info->store_mfn);
242 	xen_start_info->console.domU.mfn = MFNTOPFN(xen_start_info->console.domU.mfn);
243 
244 	/*
245 	 * We'll stop somewhere inside this hypercall. When it returns,
246 	 * we'll start resuming after the restore.
247 	 */
248 	start_info_mfn = VTOMFN(xen_start_info);
249 	pmap_suspend();
250 	HYPERVISOR_suspend(start_info_mfn);
251 	pmap_resume();
252 
253 	pmap_kenter_ma((vm_offset_t) shared_info, xen_start_info->shared_info);
254 	HYPERVISOR_shared_info = shared_info;
255 
256 	HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
257 		VTOMFN(xen_pfn_to_mfn_frame_list_list);
258 
259 	fpp = PAGE_SIZE/sizeof(unsigned long);
260 	for (i = 0, j = 0, k = -1; i < max_pfn; i += fpp, j++) {
261 		if ((j % fpp) == 0) {
262 			k++;
263 			xen_pfn_to_mfn_frame_list_list[k] =
264 				VTOMFN(xen_pfn_to_mfn_frame_list[k]);
265 			j = 0;
266 		}
267 		xen_pfn_to_mfn_frame_list[k][j] =
268 			VTOMFN(&xen_phys_machine[i]);
269 	}
270 	HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
271 
272 	gnttab_resume();
273 	irq_resume();
274 	local_irq_enable();
275 	xencons_resume();
276 
277 #ifdef CONFIG_SMP
278 	for_each_cpu(i)
279 		vcpu_prepare(i);
280 
281 #endif
282 	/*
283 	 * Only resume xenbus /after/ we've prepared our VCPUs; otherwise
284 	 * the VCPU hotplug callback can race with our vcpu_prepare
285 	 */
286 	DEVICE_RESUME(root_bus);
287 
288 #ifdef SMP
289 	thread_lock(curthread);
290 	sched_unbind(curthread);
291 	thread_unlock(curthread);
292 	if (map)
293 		restart_cpus(map);
294 #endif
295 }
296 
297 static void
298 xen_pv_shutdown_final(void *arg, int howto)
299 {
300 	/*
301 	 * Inform the hypervisor that shutdown is complete.
302 	 * This is not necessary in HVM domains since Xen
303 	 * emulates ACPI in that mode and FreeBSD's ACPI
304 	 * support will request this transition.
305 	 */
306 	if (howto & (RB_HALT | RB_POWEROFF))
307 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
308 	else
309 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
310 }
311 
312 #else
313 extern void xenpci_resume(void);
314 
315 /* HVM mode suspension. */
316 static void
317 xctrl_suspend()
318 {
319 	int suspend_cancelled;
320 
321 	if (DEVICE_SUSPEND(root_bus)) {
322 		printf("xen_suspend: device_suspend failed\n");
323 		return;
324 	}
325 
326 	/*
327 	 * Make sure we don't change cpus or switch to some other
328 	 * thread. for the duration.
329 	 */
330 	critical_enter();
331 
332 	/*
333 	 * Prevent any races with evtchn_interrupt() handler.
334 	 */
335 	irq_suspend();
336 	disable_intr();
337 
338 	suspend_cancelled = HYPERVISOR_suspend(0);
339 	if (!suspend_cancelled)
340 		xenpci_resume();
341 
342 	/*
343 	 * Re-enable interrupts and put the scheduler back to normal.
344 	 */
345 	enable_intr();
346 	critical_exit();
347 
348 	/*
349 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
350 	 * similar.
351 	 */
352 	if (!suspend_cancelled)
353 		DEVICE_RESUME(root_bus);
354 }
355 #endif
356 
357 static void
358 xctrl_crash()
359 {
360 	panic("Xen directed crash");
361 }
362 
363 static void
364 xctrl_halt()
365 {
366 	shutdown_nice(RB_HALT);
367 }
368 
369 /*------------------------------ Event Reception -----------------------------*/
370 static void
371 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
372 {
373 	struct xctrl_shutdown_reason *reason;
374 	struct xctrl_shutdown_reason *last_reason;
375 	char *result;
376 	int   error;
377 	int   result_len;
378 
379 	error = xs_read(XST_NIL, "control", "shutdown",
380 			&result_len, (void **)&result);
381 	if (error != 0)
382 		return;
383 
384 	reason = xctrl_shutdown_reasons;
385 	last_reason = reason + NUM_ELEMENTS(xctrl_shutdown_reasons);
386 	while (reason < last_reason) {
387 
388 		if (!strcmp(result, reason->name)) {
389 			reason->handler();
390 			break;
391 		}
392 		reason++;
393 	}
394 
395 	free(result, M_XENSTORE);
396 }
397 
398 /*------------------ Private Device Attachment Functions  --------------------*/
399 /**
400  * \brief Identify instances of this device type in the system.
401  *
402  * \param driver  The driver performing this identify action.
403  * \param parent  The NewBus parent device for any devices this method adds.
404  */
405 static void
406 xctrl_identify(driver_t *driver __unused, device_t parent)
407 {
408 	/*
409 	 * A single device instance for our driver is always present
410 	 * in a system operating under Xen.
411 	 */
412 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
413 }
414 
415 /**
416  * \brief Probe for the existance of the Xen Control device
417  *
418  * \param dev  NewBus device_t for this Xen control instance.
419  *
420  * \return  Always returns 0 indicating success.
421  */
422 static int
423 xctrl_probe(device_t dev)
424 {
425 	device_set_desc(dev, "Xen Control Device");
426 
427 	return (0);
428 }
429 
430 /**
431  * \brief Attach the Xen control device.
432  *
433  * \param dev  NewBus device_t for this Xen control instance.
434  *
435  * \return  On success, 0. Otherwise an errno value indicating the
436  *          type of failure.
437  */
438 static int
439 xctrl_attach(device_t dev)
440 {
441 	struct xctrl_softc *xctrl;
442 
443 	xctrl = device_get_softc(dev);
444 
445 	/* Activate watch */
446 	xctrl->xctrl_watch.node = "control/shutdown";
447 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
448 	xs_register_watch(&xctrl->xctrl_watch);
449 
450 #ifndef XENHVM
451 	EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
452 			      SHUTDOWN_PRI_LAST);
453 #endif
454 
455 	return (0);
456 }
457 
458 /**
459  * \brief Detach the Xen control device.
460  *
461  * \param dev  NewBus device_t for this Xen control device instance.
462  *
463  * \return  On success, 0. Otherwise an errno value indicating the
464  *          type of failure.
465  */
466 static int
467 xctrl_detach(device_t dev)
468 {
469 	struct xctrl_softc *xctrl;
470 
471 	xctrl = device_get_softc(dev);
472 
473 	/* Release watch */
474 	xs_unregister_watch(&xctrl->xctrl_watch);
475 
476 	return (0);
477 }
478 
479 /*-------------------- Private Device Attachment Data  -----------------------*/
480 static device_method_t xctrl_methods[] = {
481 	/* Device interface */
482 	DEVMETHOD(device_identify,	xctrl_identify),
483 	DEVMETHOD(device_probe,         xctrl_probe),
484 	DEVMETHOD(device_attach,        xctrl_attach),
485 	DEVMETHOD(device_detach,        xctrl_detach),
486 
487 	{ 0, 0 }
488 };
489 
490 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
491 devclass_t xctrl_devclass;
492 
493 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, 0, 0);
494