xref: /freebsd/sys/dev/xen/control/control.c (revision 033e1e35d38d38a582c4acc72e3745dbaf27ab53)
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 	struct thread *td;
207 	cpuset_t map;
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 	KASSERT(PCPU_GET(cpuid) == 0, ("xen_suspend: not running on cpu 0"));
216 
217 	sched_pin();
218 	map = PCPU_GET(other_cpus);
219 	sched_unpin();
220 	CPU_NAND(&map, &stopped_cpus);
221 	if (!CPU_EMPTY(&map))
222 		stop_cpus(map);
223 #endif
224 
225 	if (DEVICE_SUSPEND(root_bus) != 0) {
226 		printf("xen_suspend: device_suspend failed\n");
227 #ifdef SMP
228 		if (!CPU_EMPTY(&map))
229 			restart_cpus(map);
230 #endif
231 		return;
232 	}
233 
234 	local_irq_disable();
235 
236 	xencons_suspend();
237 	gnttab_suspend();
238 
239 	max_pfn = HYPERVISOR_shared_info->arch.max_pfn;
240 
241 	void *shared_info = HYPERVISOR_shared_info;
242 	HYPERVISOR_shared_info = NULL;
243 	pmap_kremove((vm_offset_t) shared_info);
244 	PT_UPDATES_FLUSH();
245 
246 	xen_start_info->store_mfn = MFNTOPFN(xen_start_info->store_mfn);
247 	xen_start_info->console.domU.mfn = MFNTOPFN(xen_start_info->console.domU.mfn);
248 
249 	/*
250 	 * We'll stop somewhere inside this hypercall. When it returns,
251 	 * we'll start resuming after the restore.
252 	 */
253 	start_info_mfn = VTOMFN(xen_start_info);
254 	pmap_suspend();
255 	HYPERVISOR_suspend(start_info_mfn);
256 	pmap_resume();
257 
258 	pmap_kenter_ma((vm_offset_t) shared_info, xen_start_info->shared_info);
259 	HYPERVISOR_shared_info = shared_info;
260 
261 	HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
262 		VTOMFN(xen_pfn_to_mfn_frame_list_list);
263 
264 	fpp = PAGE_SIZE/sizeof(unsigned long);
265 	for (i = 0, j = 0, k = -1; i < max_pfn; i += fpp, j++) {
266 		if ((j % fpp) == 0) {
267 			k++;
268 			xen_pfn_to_mfn_frame_list_list[k] =
269 				VTOMFN(xen_pfn_to_mfn_frame_list[k]);
270 			j = 0;
271 		}
272 		xen_pfn_to_mfn_frame_list[k][j] =
273 			VTOMFN(&xen_phys_machine[i]);
274 	}
275 	HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
276 
277 	gnttab_resume();
278 	irq_resume();
279 	local_irq_enable();
280 	xencons_resume();
281 
282 #ifdef CONFIG_SMP
283 	for_each_cpu(i)
284 		vcpu_prepare(i);
285 
286 #endif
287 	/*
288 	 * Only resume xenbus /after/ we've prepared our VCPUs; otherwise
289 	 * the VCPU hotplug callback can race with our vcpu_prepare
290 	 */
291 	DEVICE_RESUME(root_bus);
292 
293 #ifdef SMP
294 	thread_lock(curthread);
295 	sched_unbind(curthread);
296 	thread_unlock(curthread);
297 	if (!CPU_EMPTY(&map))
298 		restart_cpus(map);
299 #endif
300 }
301 
302 static void
303 xen_pv_shutdown_final(void *arg, int howto)
304 {
305 	/*
306 	 * Inform the hypervisor that shutdown is complete.
307 	 * This is not necessary in HVM domains since Xen
308 	 * emulates ACPI in that mode and FreeBSD's ACPI
309 	 * support will request this transition.
310 	 */
311 	if (howto & (RB_HALT | RB_POWEROFF))
312 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
313 	else
314 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
315 }
316 
317 #else
318 extern void xenpci_resume(void);
319 
320 /* HVM mode suspension. */
321 static void
322 xctrl_suspend()
323 {
324 	int suspend_cancelled;
325 
326 	if (DEVICE_SUSPEND(root_bus)) {
327 		printf("xen_suspend: device_suspend failed\n");
328 		return;
329 	}
330 
331 	/*
332 	 * Make sure we don't change cpus or switch to some other
333 	 * thread. for the duration.
334 	 */
335 	critical_enter();
336 
337 	/*
338 	 * Prevent any races with evtchn_interrupt() handler.
339 	 */
340 	irq_suspend();
341 	disable_intr();
342 
343 	suspend_cancelled = HYPERVISOR_suspend(0);
344 	if (!suspend_cancelled)
345 		xenpci_resume();
346 
347 	/*
348 	 * Re-enable interrupts and put the scheduler back to normal.
349 	 */
350 	enable_intr();
351 	critical_exit();
352 
353 	/*
354 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
355 	 * similar.
356 	 */
357 	if (!suspend_cancelled)
358 		DEVICE_RESUME(root_bus);
359 }
360 #endif
361 
362 static void
363 xctrl_crash()
364 {
365 	panic("Xen directed crash");
366 }
367 
368 static void
369 xctrl_halt()
370 {
371 	shutdown_nice(RB_HALT);
372 }
373 
374 /*------------------------------ Event Reception -----------------------------*/
375 static void
376 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
377 {
378 	struct xctrl_shutdown_reason *reason;
379 	struct xctrl_shutdown_reason *last_reason;
380 	char *result;
381 	int   error;
382 	int   result_len;
383 
384 	error = xs_read(XST_NIL, "control", "shutdown",
385 			&result_len, (void **)&result);
386 	if (error != 0)
387 		return;
388 
389 	reason = xctrl_shutdown_reasons;
390 	last_reason = reason + NUM_ELEMENTS(xctrl_shutdown_reasons);
391 	while (reason < last_reason) {
392 
393 		if (!strcmp(result, reason->name)) {
394 			reason->handler();
395 			break;
396 		}
397 		reason++;
398 	}
399 
400 	free(result, M_XENSTORE);
401 }
402 
403 /*------------------ Private Device Attachment Functions  --------------------*/
404 /**
405  * \brief Identify instances of this device type in the system.
406  *
407  * \param driver  The driver performing this identify action.
408  * \param parent  The NewBus parent device for any devices this method adds.
409  */
410 static void
411 xctrl_identify(driver_t *driver __unused, device_t parent)
412 {
413 	/*
414 	 * A single device instance for our driver is always present
415 	 * in a system operating under Xen.
416 	 */
417 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
418 }
419 
420 /**
421  * \brief Probe for the existance of the Xen Control device
422  *
423  * \param dev  NewBus device_t for this Xen control instance.
424  *
425  * \return  Always returns 0 indicating success.
426  */
427 static int
428 xctrl_probe(device_t dev)
429 {
430 	device_set_desc(dev, "Xen Control Device");
431 
432 	return (0);
433 }
434 
435 /**
436  * \brief Attach the Xen control device.
437  *
438  * \param dev  NewBus device_t for this Xen control instance.
439  *
440  * \return  On success, 0. Otherwise an errno value indicating the
441  *          type of failure.
442  */
443 static int
444 xctrl_attach(device_t dev)
445 {
446 	struct xctrl_softc *xctrl;
447 
448 	xctrl = device_get_softc(dev);
449 
450 	/* Activate watch */
451 	xctrl->xctrl_watch.node = "control/shutdown";
452 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
453 	xs_register_watch(&xctrl->xctrl_watch);
454 
455 #ifndef XENHVM
456 	EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
457 			      SHUTDOWN_PRI_LAST);
458 #endif
459 
460 	return (0);
461 }
462 
463 /**
464  * \brief Detach the Xen control device.
465  *
466  * \param dev  NewBus device_t for this Xen control device instance.
467  *
468  * \return  On success, 0. Otherwise an errno value indicating the
469  *          type of failure.
470  */
471 static int
472 xctrl_detach(device_t dev)
473 {
474 	struct xctrl_softc *xctrl;
475 
476 	xctrl = device_get_softc(dev);
477 
478 	/* Release watch */
479 	xs_unregister_watch(&xctrl->xctrl_watch);
480 
481 	return (0);
482 }
483 
484 /*-------------------- Private Device Attachment Data  -----------------------*/
485 static device_method_t xctrl_methods[] = {
486 	/* Device interface */
487 	DEVMETHOD(device_identify,	xctrl_identify),
488 	DEVMETHOD(device_probe,         xctrl_probe),
489 	DEVMETHOD(device_attach,        xctrl_attach),
490 	DEVMETHOD(device_detach,        xctrl_detach),
491 
492 	{ 0, 0 }
493 };
494 
495 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
496 devclass_t xctrl_devclass;
497 
498 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, 0, 0);
499