xref: /freebsd/sys/dev/xen/control/control.c (revision e8e8c939350bdf3c228a411caa9660c607c27a11)
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 #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 
160 /*-------------------------- Private Data Structures -------------------------*/
161 /** Element type for lookup table of event name to handler. */
162 struct xctrl_shutdown_reason {
163 	const char		 *name;
164 	xctrl_shutdown_handler_t *handler;
165 };
166 
167 /** Lookup table for shutdown event name to handler. */
168 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
169 	{ "poweroff", xctrl_poweroff },
170 	{ "reboot",   xctrl_reboot   },
171 	{ "suspend",  xctrl_suspend  },
172 	{ "crash",    xctrl_crash    },
173 	{ "halt",     xctrl_poweroff },
174 };
175 
176 struct xctrl_softc {
177 	struct xs_watch    xctrl_watch;
178 };
179 
180 /*------------------------------ Event Handlers ------------------------------*/
181 static void
182 xctrl_poweroff()
183 {
184 	shutdown_nice(RB_POWEROFF|RB_HALT);
185 }
186 
187 static void
188 xctrl_reboot()
189 {
190 	shutdown_nice(0);
191 }
192 
193 static void
194 xctrl_suspend()
195 {
196 #ifdef SMP
197 	cpuset_t cpu_suspend_map;
198 #endif
199 	int suspend_cancelled;
200 
201 	EVENTHANDLER_INVOKE(power_suspend);
202 
203 	if (smp_started) {
204 		thread_lock(curthread);
205 		sched_bind(curthread, 0);
206 		thread_unlock(curthread);
207 	}
208 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
209 
210 	/*
211 	 * Clear our XenStore node so the toolstack knows we are
212 	 * responding to the suspend request.
213 	 */
214 	xs_write(XST_NIL, "control", "shutdown", "");
215 
216 	/*
217 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
218 	 * drivers need this.
219 	 */
220 	mtx_lock(&Giant);
221 	if (DEVICE_SUSPEND(root_bus) != 0) {
222 		mtx_unlock(&Giant);
223 		printf("%s: device_suspend failed\n", __func__);
224 		return;
225 	}
226 	mtx_unlock(&Giant);
227 
228 #ifdef SMP
229 	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
230 	if (smp_started) {
231 		/*
232 		 * Suspend other CPUs. This prevents IPIs while we
233 		 * are resuming, and will allow us to reset per-cpu
234 		 * vcpu_info on resume.
235 		 */
236 		cpu_suspend_map = all_cpus;
237 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
238 		if (!CPU_EMPTY(&cpu_suspend_map))
239 			suspend_cpus(cpu_suspend_map);
240 	}
241 #endif
242 
243 	/*
244 	 * Prevent any races with evtchn_interrupt() handler.
245 	 */
246 	disable_intr();
247 	intr_suspend();
248 	xen_hvm_suspend();
249 
250 	suspend_cancelled = HYPERVISOR_suspend(0);
251 
252 	xen_hvm_resume(suspend_cancelled != 0);
253 	intr_resume(suspend_cancelled != 0);
254 	enable_intr();
255 
256 	/*
257 	 * Reset grant table info.
258 	 */
259 	gnttab_resume(NULL);
260 
261 #ifdef SMP
262 	if (smp_started && !CPU_EMPTY(&cpu_suspend_map)) {
263 		/*
264 		 * Now that event channels have been initialized,
265 		 * resume CPUs.
266 		 */
267 		resume_cpus(cpu_suspend_map);
268 	}
269 #endif
270 
271 	/*
272 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
273 	 * similar.
274 	 */
275 	mtx_lock(&Giant);
276 	DEVICE_RESUME(root_bus);
277 	mtx_unlock(&Giant);
278 
279 	if (smp_started) {
280 		thread_lock(curthread);
281 		sched_unbind(curthread);
282 		thread_unlock(curthread);
283 	}
284 
285 	EVENTHANDLER_INVOKE(power_resume);
286 
287 	if (bootverbose)
288 		printf("System resumed after suspension\n");
289 
290 }
291 
292 static void
293 xctrl_crash()
294 {
295 	panic("Xen directed crash");
296 }
297 
298 static void
299 xen_pv_shutdown_final(void *arg, int howto)
300 {
301 	/*
302 	 * Inform the hypervisor that shutdown is complete.
303 	 * This is not necessary in HVM domains since Xen
304 	 * emulates ACPI in that mode and FreeBSD's ACPI
305 	 * support will request this transition.
306 	 */
307 	if (howto & (RB_HALT | RB_POWEROFF))
308 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
309 	else
310 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
311 }
312 
313 /*------------------------------ Event Reception -----------------------------*/
314 static void
315 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
316 {
317 	const struct xctrl_shutdown_reason *reason;
318 	const struct xctrl_shutdown_reason *last_reason;
319 	char *result;
320 	int   error;
321 	int   result_len;
322 
323 	error = xs_read(XST_NIL, "control", "shutdown",
324 			&result_len, (void **)&result);
325 	if (error != 0)
326 		return;
327 
328 	reason = xctrl_shutdown_reasons;
329 	last_reason = reason + nitems(xctrl_shutdown_reasons);
330 	while (reason < last_reason) {
331 
332 		if (!strcmp(result, reason->name)) {
333 			reason->handler();
334 			break;
335 		}
336 		reason++;
337 	}
338 
339 	free(result, M_XENSTORE);
340 }
341 
342 /*------------------ Private Device Attachment Functions  --------------------*/
343 /**
344  * \brief Identify instances of this device type in the system.
345  *
346  * \param driver  The driver performing this identify action.
347  * \param parent  The NewBus parent device for any devices this method adds.
348  */
349 static void
350 xctrl_identify(driver_t *driver __unused, device_t parent)
351 {
352 	/*
353 	 * A single device instance for our driver is always present
354 	 * in a system operating under Xen.
355 	 */
356 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
357 }
358 
359 /**
360  * \brief Probe for the existance of the Xen Control device
361  *
362  * \param dev  NewBus device_t for this Xen control instance.
363  *
364  * \return  Always returns 0 indicating success.
365  */
366 static int
367 xctrl_probe(device_t dev)
368 {
369 	device_set_desc(dev, "Xen Control Device");
370 
371 	return (0);
372 }
373 
374 /**
375  * \brief Attach the Xen control device.
376  *
377  * \param dev  NewBus device_t for this Xen control instance.
378  *
379  * \return  On success, 0. Otherwise an errno value indicating the
380  *          type of failure.
381  */
382 static int
383 xctrl_attach(device_t dev)
384 {
385 	struct xctrl_softc *xctrl;
386 
387 	xctrl = device_get_softc(dev);
388 
389 	/* Activate watch */
390 	xctrl->xctrl_watch.node = "control/shutdown";
391 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
392 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
393 	xs_register_watch(&xctrl->xctrl_watch);
394 
395 	if (xen_pv_domain())
396 		EVENTHANDLER_REGISTER(shutdown_final, xen_pv_shutdown_final, NULL,
397 		                      SHUTDOWN_PRI_LAST);
398 
399 	return (0);
400 }
401 
402 /**
403  * \brief Detach the Xen control device.
404  *
405  * \param dev  NewBus device_t for this Xen control device instance.
406  *
407  * \return  On success, 0. Otherwise an errno value indicating the
408  *          type of failure.
409  */
410 static int
411 xctrl_detach(device_t dev)
412 {
413 	struct xctrl_softc *xctrl;
414 
415 	xctrl = device_get_softc(dev);
416 
417 	/* Release watch */
418 	xs_unregister_watch(&xctrl->xctrl_watch);
419 
420 	return (0);
421 }
422 
423 /*-------------------- Private Device Attachment Data  -----------------------*/
424 static device_method_t xctrl_methods[] = {
425 	/* Device interface */
426 	DEVMETHOD(device_identify,	xctrl_identify),
427 	DEVMETHOD(device_probe,         xctrl_probe),
428 	DEVMETHOD(device_attach,        xctrl_attach),
429 	DEVMETHOD(device_detach,        xctrl_detach),
430 
431 	DEVMETHOD_END
432 };
433 
434 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
435 devclass_t xctrl_devclass;
436 
437 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, xctrl_devclass, NULL, NULL);
438