xref: /freebsd/sys/dev/xen/control/control.c (revision 5ca34122ecdd5abc62bdae39663fec9ac8523d87)
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 #include <sys/sched.h>
123 #include <sys/smp.h>
124 #include <sys/eventhandler.h>
125 
126 #include <geom/geom.h>
127 
128 #include <machine/_inttypes.h>
129 #include <machine/intr_machdep.h>
130 
131 #include <vm/vm.h>
132 #include <vm/vm_extern.h>
133 #include <vm/vm_kern.h>
134 
135 #include <xen/xen-os.h>
136 #include <xen/blkif.h>
137 #include <xen/evtchn.h>
138 #include <xen/gnttab.h>
139 #include <xen/xen_intr.h>
140 
141 #include <xen/hvm.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 /*--------------------------- Forward Declarations --------------------------*/
149 /** Function signature for shutdown event handlers. */
150 typedef	void (xctrl_shutdown_handler_t)(void);
151 
152 static xctrl_shutdown_handler_t xctrl_poweroff;
153 static xctrl_shutdown_handler_t xctrl_reboot;
154 static xctrl_shutdown_handler_t xctrl_suspend;
155 static xctrl_shutdown_handler_t xctrl_crash;
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_poweroff },
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 static void
191 xctrl_suspend()
192 {
193 #ifdef SMP
194 	cpuset_t cpu_suspend_map;
195 #endif
196 	int suspend_cancelled;
197 
198 	EVENTHANDLER_INVOKE(power_suspend);
199 
200 	if (smp_started) {
201 		thread_lock(curthread);
202 		sched_bind(curthread, 0);
203 		thread_unlock(curthread);
204 	}
205 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
206 
207 	/*
208 	 * Clear our XenStore node so the toolstack knows we are
209 	 * responding to the suspend request.
210 	 */
211 	xs_write(XST_NIL, "control", "shutdown", "");
212 
213 	/*
214 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
215 	 * drivers need this.
216 	 */
217 	mtx_lock(&Giant);
218 	if (DEVICE_SUSPEND(root_bus) != 0) {
219 		mtx_unlock(&Giant);
220 		printf("%s: device_suspend failed\n", __func__);
221 		return;
222 	}
223 	mtx_unlock(&Giant);
224 
225 #ifdef SMP
226 	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
227 	if (smp_started) {
228 		/*
229 		 * Suspend other CPUs. This prevents IPIs while we
230 		 * are resuming, and will allow us to reset per-cpu
231 		 * vcpu_info on resume.
232 		 */
233 		cpu_suspend_map = all_cpus;
234 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
235 		if (!CPU_EMPTY(&cpu_suspend_map))
236 			suspend_cpus(cpu_suspend_map);
237 	}
238 #endif
239 
240 	/*
241 	 * Prevent any races with evtchn_interrupt() handler.
242 	 */
243 	disable_intr();
244 	intr_suspend();
245 	xen_hvm_suspend();
246 
247 	suspend_cancelled = HYPERVISOR_suspend(0);
248 
249 	xen_hvm_resume(suspend_cancelled != 0);
250 	intr_resume(suspend_cancelled != 0);
251 	enable_intr();
252 
253 	/*
254 	 * Reset grant table info.
255 	 */
256 	gnttab_resume(NULL);
257 
258 #ifdef SMP
259 	if (smp_started && !CPU_EMPTY(&cpu_suspend_map)) {
260 		/*
261 		 * Now that event channels have been initialized,
262 		 * resume CPUs.
263 		 */
264 		resume_cpus(cpu_suspend_map);
265 	}
266 #endif
267 
268 	/*
269 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
270 	 * similar.
271 	 */
272 	mtx_lock(&Giant);
273 	DEVICE_RESUME(root_bus);
274 	mtx_unlock(&Giant);
275 
276 	if (smp_started) {
277 		thread_lock(curthread);
278 		sched_unbind(curthread);
279 		thread_unlock(curthread);
280 	}
281 
282 	EVENTHANDLER_INVOKE(power_resume);
283 
284 	if (bootverbose)
285 		printf("System resumed after suspension\n");
286 
287 }
288 
289 static void
290 xctrl_crash()
291 {
292 	panic("Xen directed crash");
293 }
294 
295 static void
296 xen_pv_shutdown_final(void *arg, int howto)
297 {
298 	/*
299 	 * Inform the hypervisor that shutdown is complete.
300 	 * This is not necessary in HVM domains since Xen
301 	 * emulates ACPI in that mode and FreeBSD's ACPI
302 	 * support will request this transition.
303 	 */
304 	if (howto & (RB_HALT | RB_POWEROFF))
305 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
306 	else
307 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
308 }
309 
310 /*------------------------------ Event Reception -----------------------------*/
311 static void
312 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
313 {
314 	const struct xctrl_shutdown_reason *reason;
315 	const struct xctrl_shutdown_reason *last_reason;
316 	char *result;
317 	int   error;
318 	int   result_len;
319 
320 	error = xs_read(XST_NIL, "control", "shutdown",
321 			&result_len, (void **)&result);
322 	if (error != 0)
323 		return;
324 
325 	reason = xctrl_shutdown_reasons;
326 	last_reason = reason + nitems(xctrl_shutdown_reasons);
327 	while (reason < last_reason) {
328 
329 		if (!strcmp(result, reason->name)) {
330 			reason->handler();
331 			break;
332 		}
333 		reason++;
334 	}
335 
336 	free(result, M_XENSTORE);
337 }
338 
339 /*------------------ Private Device Attachment Functions  --------------------*/
340 /**
341  * \brief Identify instances of this device type in the system.
342  *
343  * \param driver  The driver performing this identify action.
344  * \param parent  The NewBus parent device for any devices this method adds.
345  */
346 static void
347 xctrl_identify(driver_t *driver __unused, device_t parent)
348 {
349 	/*
350 	 * A single device instance for our driver is always present
351 	 * in a system operating under Xen.
352 	 */
353 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
354 }
355 
356 /**
357  * \brief Probe for the existance of the Xen Control device
358  *
359  * \param dev  NewBus device_t for this Xen control instance.
360  *
361  * \return  Always returns 0 indicating success.
362  */
363 static int
364 xctrl_probe(device_t dev)
365 {
366 	device_set_desc(dev, "Xen Control Device");
367 
368 	return (0);
369 }
370 
371 /**
372  * \brief Attach the Xen control device.
373  *
374  * \param dev  NewBus device_t for this Xen control instance.
375  *
376  * \return  On success, 0. Otherwise an errno value indicating the
377  *          type of failure.
378  */
379 static int
380 xctrl_attach(device_t dev)
381 {
382 	struct xctrl_softc *xctrl;
383 
384 	xctrl = device_get_softc(dev);
385 
386 	/* Activate watch */
387 	xctrl->xctrl_watch.node = "control/shutdown";
388 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
389 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
390 	xs_register_watch(&xctrl->xctrl_watch);
391 
392 	if (xen_pv_domain())
393 		EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
394 		                      SHUTDOWN_PRI_LAST);
395 
396 	return (0);
397 }
398 
399 /**
400  * \brief Detach the Xen control device.
401  *
402  * \param dev  NewBus device_t for this Xen control device instance.
403  *
404  * \return  On success, 0. Otherwise an errno value indicating the
405  *          type of failure.
406  */
407 static int
408 xctrl_detach(device_t dev)
409 {
410 	struct xctrl_softc *xctrl;
411 
412 	xctrl = device_get_softc(dev);
413 
414 	/* Release watch */
415 	xs_unregister_watch(&xctrl->xctrl_watch);
416 
417 	return (0);
418 }
419 
420 /*-------------------- Private Device Attachment Data  -----------------------*/
421 static device_method_t xctrl_methods[] = {
422 	/* Device interface */
423 	DEVMETHOD(device_identify,	xctrl_identify),
424 	DEVMETHOD(device_probe,         xctrl_probe),
425 	DEVMETHOD(device_attach,        xctrl_attach),
426 	DEVMETHOD(device_detach,        xctrl_detach),
427 
428 	DEVMETHOD_END
429 };
430 
431 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
432 devclass_t xctrl_devclass;
433 
434 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
435