xref: /freebsd-13-stable/sys/dev/xen/control/control.c (revision 3bc80996974a61a4223eae4c1ccd47b6ee32a48a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause AND BSD-4-Clause
3  *
4  * Copyright (c) 2010 Justin T. Gibbs, Spectra Logic Corporation
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
14  *    substantially similar to the "NO WARRANTY" disclaimer below
15  *    ("Disclaimer") and any redistribution must be conditioned upon
16  *    including a substantially similar Disclaimer requirement for further
17  *    binary redistribution.
18  *
19  * NO WARRANTY
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
28  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGES.
31  */
32 
33 /*-
34  * PV suspend/resume support:
35  *
36  * Copyright (c) 2004 Christian Limpach.
37  * Copyright (c) 2004-2006,2008 Kip Macy
38  * All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  * 3. All advertising materials mentioning features or use of this software
49  *    must display the following acknowledgement:
50  *      This product includes software developed by Christian Limpach.
51  * 4. The name of the author may not be used to endorse or promote products
52  *    derived from this software without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
55  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
56  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
57  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
58  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
59  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
60  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
61  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
62  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
63  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64  */
65 
66 /*-
67  * HVM suspend/resume support:
68  *
69  * Copyright (c) 2008 Citrix Systems, Inc.
70  * All rights reserved.
71  *
72  * Redistribution and use in source and binary forms, with or without
73  * modification, are permitted provided that the following conditions
74  * are met:
75  * 1. Redistributions of source code must retain the above copyright
76  *    notice, this list of conditions and the following disclaimer.
77  * 2. Redistributions in binary form must reproduce the above copyright
78  *    notice, this list of conditions and the following disclaimer in the
79  *    documentation and/or other materials provided with the distribution.
80  *
81  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
82  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
83  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
84  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
85  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
86  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
87  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
88  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
89  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
90  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
91  * SUCH DAMAGE.
92  */
93 #include <sys/cdefs.h>
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/mount.h>
115 #include <sys/namei.h>
116 #include <sys/proc.h>
117 #include <sys/reboot.h>
118 #include <sys/rman.h>
119 #include <sys/sched.h>
120 #include <sys/taskqueue.h>
121 #include <sys/types.h>
122 #include <sys/vnode.h>
123 #include <sys/sched.h>
124 #include <sys/smp.h>
125 #include <sys/eventhandler.h>
126 #include <sys/timetc.h>
127 
128 #include <geom/geom.h>
129 
130 #include <machine/_inttypes.h>
131 #include <machine/intr_machdep.h>
132 
133 #include <x86/apicvar.h>
134 
135 #include <vm/vm.h>
136 #include <vm/vm_extern.h>
137 #include <vm/vm_kern.h>
138 
139 #include <xen/xen-os.h>
140 #include <xen/blkif.h>
141 #include <xen/evtchn.h>
142 #include <xen/gnttab.h>
143 #include <xen/xen_intr.h>
144 
145 #include <xen/hvm.h>
146 
147 #include <xen/interface/event_channel.h>
148 #include <xen/interface/grant_table.h>
149 
150 #include <xen/xenbus/xenbusvar.h>
151 
152 bool xen_suspend_cancelled;
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 
162 /*-------------------------- Private Data Structures -------------------------*/
163 /** Element type for lookup table of event name to handler. */
164 struct xctrl_shutdown_reason {
165 	const char		 *name;
166 	xctrl_shutdown_handler_t *handler;
167 };
168 
169 /** Lookup table for shutdown event name to handler. */
170 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
171 	{ "poweroff", xctrl_poweroff },
172 	{ "reboot",   xctrl_reboot   },
173 	{ "suspend",  xctrl_suspend  },
174 	{ "crash",    xctrl_crash    },
175 	{ "halt",     xctrl_poweroff },
176 };
177 
178 struct xctrl_softc {
179 	struct xs_watch    xctrl_watch;
180 };
181 
182 /*------------------------------ Event Handlers ------------------------------*/
183 static void
xctrl_poweroff(void)184 xctrl_poweroff(void)
185 {
186 	shutdown_nice(RB_POWEROFF|RB_HALT);
187 }
188 
189 static void
xctrl_reboot(void)190 xctrl_reboot(void)
191 {
192 	shutdown_nice(0);
193 }
194 
195 static void
xctrl_suspend(void)196 xctrl_suspend(void)
197 {
198 #ifdef SMP
199 	cpuset_t cpu_suspend_map;
200 #endif
201 
202 	EVENTHANDLER_INVOKE(power_suspend_early);
203 	xs_lock();
204 	stop_all_proc();
205 	xs_unlock();
206 	suspend_all_fs();
207 	EVENTHANDLER_INVOKE(power_suspend);
208 
209 #ifdef EARLY_AP_STARTUP
210 	MPASS(mp_ncpus == 1 || smp_started);
211 	thread_lock(curthread);
212 	sched_bind(curthread, 0);
213 	thread_unlock(curthread);
214 #else
215 	if (smp_started) {
216 		thread_lock(curthread);
217 		sched_bind(curthread, 0);
218 		thread_unlock(curthread);
219 	}
220 #endif
221 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
222 
223 	/*
224 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME.
225 	 */
226 	bus_topo_lock();
227 	if (DEVICE_SUSPEND(root_bus) != 0) {
228 		bus_topo_unlock();
229 		printf("%s: device_suspend failed\n", __func__);
230 		return;
231 	}
232 
233 #ifdef SMP
234 #ifdef EARLY_AP_STARTUP
235 	/*
236 	 * Suspend other CPUs. This prevents IPIs while we
237 	 * are resuming, and will allow us to reset per-cpu
238 	 * vcpu_info on resume.
239 	 */
240 	cpu_suspend_map = all_cpus;
241 	CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
242 	if (!CPU_EMPTY(&cpu_suspend_map))
243 		suspend_cpus(cpu_suspend_map);
244 #else
245 	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
246 	if (smp_started) {
247 		/*
248 		 * Suspend other CPUs. This prevents IPIs while we
249 		 * are resuming, and will allow us to reset per-cpu
250 		 * vcpu_info on resume.
251 		 */
252 		cpu_suspend_map = all_cpus;
253 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
254 		if (!CPU_EMPTY(&cpu_suspend_map))
255 			suspend_cpus(cpu_suspend_map);
256 	}
257 #endif
258 #endif
259 
260 	/*
261 	 * Prevent any races with evtchn_interrupt() handler.
262 	 */
263 	disable_intr();
264 	intr_suspend();
265 	xen_hvm_suspend();
266 
267 	xen_suspend_cancelled = !!HYPERVISOR_suspend(0);
268 
269 	if (!xen_suspend_cancelled) {
270 		xen_hvm_resume(false);
271 	}
272 	intr_resume(xen_suspend_cancelled != 0);
273 	enable_intr();
274 
275 	/*
276 	 * Reset grant table info.
277 	 */
278 	if (!xen_suspend_cancelled) {
279 		gnttab_resume(NULL);
280 	}
281 
282 #ifdef SMP
283 	if (!CPU_EMPTY(&cpu_suspend_map)) {
284 		/*
285 		 * Now that event channels have been initialized,
286 		 * resume CPUs.
287 		 */
288 		resume_cpus(cpu_suspend_map);
289 		/* Send an IPI_BITMAP in case there are pending bitmap IPIs. */
290 		lapic_ipi_vectored(IPI_BITMAP_VECTOR, APIC_IPI_DEST_ALL);
291 	}
292 #endif
293 
294 	/*
295 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
296 	 * similar.
297 	 */
298 	DEVICE_RESUME(root_bus);
299 	bus_topo_unlock();
300 
301 	/*
302 	 * Warm up timecounter again and reset system clock.
303 	 */
304 	timecounter->tc_get_timecount(timecounter);
305 	inittodr(time_second);
306 
307 #ifdef EARLY_AP_STARTUP
308 	thread_lock(curthread);
309 	sched_unbind(curthread);
310 	thread_unlock(curthread);
311 #else
312 	if (smp_started) {
313 		thread_lock(curthread);
314 		sched_unbind(curthread);
315 		thread_unlock(curthread);
316 	}
317 #endif
318 
319 	resume_all_fs();
320 	resume_all_proc();
321 
322 	EVENTHANDLER_INVOKE(power_resume);
323 
324 	if (bootverbose)
325 		printf("System resumed after suspension\n");
326 
327 }
328 
329 static void
xctrl_crash(void)330 xctrl_crash(void)
331 {
332 	panic("Xen directed crash");
333 }
334 
335 static void
xen_pv_shutdown_final(void * arg,int howto)336 xen_pv_shutdown_final(void *arg, int howto)
337 {
338 	/*
339 	 * Inform the hypervisor that shutdown is complete.
340 	 * This is not necessary in HVM domains since Xen
341 	 * emulates ACPI in that mode and FreeBSD's ACPI
342 	 * support will request this transition.
343 	 */
344 	if (howto & (RB_HALT | RB_POWEROFF))
345 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
346 	else
347 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
348 }
349 
350 /*------------------------------ Event Reception -----------------------------*/
351 static void
xctrl_on_watch_event(struct xs_watch * watch,const char ** vec,unsigned int len)352 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
353 {
354 	const struct xctrl_shutdown_reason *reason;
355 	const struct xctrl_shutdown_reason *last_reason;
356 	char *result;
357 	int   error;
358 	int   result_len;
359 
360 	error = xs_read(XST_NIL, "control", "shutdown",
361 			&result_len, (void **)&result);
362 	if (error != 0 || result_len == 0)
363 		return;
364 
365 	/* Acknowledge the request by writing back an empty string. */
366 	error = xs_write(XST_NIL, "control", "shutdown", "");
367 	if (error != 0)
368 		printf("unable to ack shutdown request, proceeding anyway\n");
369 
370 	reason = xctrl_shutdown_reasons;
371 	last_reason = reason + nitems(xctrl_shutdown_reasons);
372 	while (reason < last_reason) {
373 		if (!strcmp(result, reason->name)) {
374 			reason->handler();
375 			break;
376 		}
377 		reason++;
378 	}
379 
380 	free(result, M_XENSTORE);
381 }
382 
383 /*------------------ Private Device Attachment Functions  --------------------*/
384 /**
385  * \brief Identify instances of this device type in the system.
386  *
387  * \param driver  The driver performing this identify action.
388  * \param parent  The NewBus parent device for any devices this method adds.
389  */
390 static void
xctrl_identify(driver_t * driver __unused,device_t parent)391 xctrl_identify(driver_t *driver __unused, device_t parent)
392 {
393 	/*
394 	 * A single device instance for our driver is always present
395 	 * in a system operating under Xen.
396 	 */
397 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
398 }
399 
400 /**
401  * \brief Probe for the existence of the Xen Control device
402  *
403  * \param dev  NewBus device_t for this Xen control instance.
404  *
405  * \return  Always returns 0 indicating success.
406  */
407 static int
xctrl_probe(device_t dev)408 xctrl_probe(device_t dev)
409 {
410 	device_set_desc(dev, "Xen Control Device");
411 
412 	return (BUS_PROBE_NOWILDCARD);
413 }
414 
415 /**
416  * \brief Attach the Xen control device.
417  *
418  * \param dev  NewBus device_t for this Xen control instance.
419  *
420  * \return  On success, 0. Otherwise an errno value indicating the
421  *          type of failure.
422  */
423 static int
xctrl_attach(device_t dev)424 xctrl_attach(device_t dev)
425 {
426 	struct xctrl_softc *xctrl;
427 
428 	xctrl = device_get_softc(dev);
429 
430 	/* Activate watch */
431 	xctrl->xctrl_watch.node = "control/shutdown";
432 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
433 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
434 	/*
435 	 * We don't care about the path updated, just about the value changes
436 	 * on that single node, hence there's no need to queue more that one
437 	 * event.
438 	 */
439 	xctrl->xctrl_watch.max_pending = 1;
440 	xs_register_watch(&xctrl->xctrl_watch);
441 
442 	if (xen_pv_domain())
443 		EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
444 		                      SHUTDOWN_PRI_LAST);
445 
446 	return (0);
447 }
448 
449 /**
450  * \brief Detach the Xen control device.
451  *
452  * \param dev  NewBus device_t for this Xen control device instance.
453  *
454  * \return  On success, 0. Otherwise an errno value indicating the
455  *          type of failure.
456  */
457 static int
xctrl_detach(device_t dev)458 xctrl_detach(device_t dev)
459 {
460 	struct xctrl_softc *xctrl;
461 
462 	xctrl = device_get_softc(dev);
463 
464 	/* Release watch */
465 	xs_unregister_watch(&xctrl->xctrl_watch);
466 
467 	return (0);
468 }
469 
470 /*-------------------- Private Device Attachment Data  -----------------------*/
471 static device_method_t xctrl_methods[] = {
472 	/* Device interface */
473 	DEVMETHOD(device_identify,	xctrl_identify),
474 	DEVMETHOD(device_probe,         xctrl_probe),
475 	DEVMETHOD(device_attach,        xctrl_attach),
476 	DEVMETHOD(device_detach,        xctrl_detach),
477 
478 	DEVMETHOD_END
479 };
480 
481 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
482 devclass_t xctrl_devclass;
483 
484 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
485