xref: /netbsd-src/sys/arch/xen/x86/hypervisor_machdep.c (revision 267197ec1eebfcb9810ea27a89625b6ddf68e3e7)
1 /*	$NetBSD: hypervisor_machdep.c,v 1.4 2007/12/20 23:46:11 ad Exp $	*/
2 
3 /*
4  *
5  * Copyright (c) 2004 Christian Limpach.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by Christian Limpach.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /******************************************************************************
35  * hypervisor.c
36  *
37  * Communication to/from hypervisor.
38  *
39  * Copyright (c) 2002-2004, K A Fraser
40  *
41  * Permission is hereby granted, free of charge, to any person obtaining a copy
42  * of this software and associated documentation files (the "Software"), to
43  * deal in the Software without restriction, including without limitation the
44  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
45  * sell copies of the Software, and to permit persons to whom the Software is
46  * furnished to do so, subject to the following conditions:
47  *
48  * The above copyright notice and this permission notice shall be included in
49  * all copies or substantial portions of the Software.
50  *
51  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
52  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
53  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
54  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
55  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
56  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
57  * DEALINGS IN THE SOFTWARE.
58  */
59 
60 
61 #include <sys/cdefs.h>
62 __KERNEL_RCSID(0, "$NetBSD: hypervisor_machdep.c,v 1.4 2007/12/20 23:46:11 ad Exp $");
63 
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 
67 #include <xen/xen.h>
68 #include <xen/hypervisor.h>
69 #include <xen/evtchn.h>
70 
71 #include "opt_xen.h"
72 
73 // #define PORT_DEBUG 4
74 // #define EARLY_DEBUG_EVENT
75 
76 int stipending(void);
77 int
78 stipending()
79 {
80 	uint32_t l1;
81 	unsigned long l2;
82 	unsigned int l1i, l2i, port;
83 	volatile shared_info_t *s = HYPERVISOR_shared_info;
84 	struct cpu_info *ci;
85 	int ret;
86 
87 	ret = 0;
88 	ci = curcpu();
89 
90 #if 0
91 	if (HYPERVISOR_shared_info->events)
92 		printf("stipending events %08lx mask %08lx ilevel %d\n",
93 		    HYPERVISOR_shared_info->events,
94 		    HYPERVISOR_shared_info->events_mask, ci->ci_ilevel);
95 #endif
96 
97 #ifdef EARLY_DEBUG_EVENT
98 	if (xen_atomic_test_bit(&s->evtchn_pending[0], debug_port)) {
99 		xen_debug_handler(NULL);
100 		xen_atomic_clear_bit(&s->evtchn_pending[0], debug_port);
101 	}
102 #endif
103 
104 	/*
105 	 * we're only called after STIC, so we know that we'll have to
106 	 * STI at the end
107 	 */
108 	while (s->vcpu_info[0].evtchn_upcall_pending) {
109 		cli();
110 		s->vcpu_info[0].evtchn_upcall_pending = 0;
111 		/* NB. No need for a barrier here -- XCHG is a barrier
112 		 * on x86. */
113 #ifdef XEN3
114 		l1 = xen_atomic_xchg(&s->vcpu_info[0].evtchn_pending_sel, 0);
115 #else
116 		l1 = xen_atomic_xchg(&s->evtchn_pending_sel, 0);
117 #endif
118 		while ((l1i = ffs(l1)) != 0) {
119 			l1i--;
120 			l1 &= ~(1 << l1i);
121 
122 			l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
123 			/*
124 			 * mask and clear event. More efficient than calling
125 			 * hypervisor_mask/clear_event for each event.
126 			 */
127 			xen_atomic_setbits_l(&s->evtchn_mask[l1i], l2);
128 			xen_atomic_clearbits_l(&s->evtchn_pending[l1i], l2);
129 			while ((l2i = ffs(l2)) != 0) {
130 				l2i--;
131 				l2 &= ~(1 << l2i);
132 
133 				port = (l1i << 5) + l2i;
134 				if (evtsource[port]) {
135 					hypervisor_set_ipending(
136 					    evtsource[port]->ev_imask,
137 					    l1i, l2i);
138 					evtsource[port]->ev_evcnt.ev_count++;
139 					if (ret == 0 && ci->ci_ilevel <
140 					    evtsource[port]->ev_maxlevel)
141 						ret = 1;
142 				}
143 #ifdef DOM0OPS
144 				else
145 					xenevt_event(port);
146 #endif
147 			}
148 		}
149 		sti();
150 	}
151 
152 #if 0
153 	if (ci->ci_ipending & 0x1)
154 		printf("stipending events %08lx mask %08lx ilevel %d ipending %08x\n",
155 		    HYPERVISOR_shared_info->events,
156 		    HYPERVISOR_shared_info->events_mask, ci->ci_ilevel,
157 		    ci->ci_ipending);
158 #endif
159 
160 	return (ret);
161 }
162 
163 void
164 do_hypervisor_callback(struct intrframe *regs)
165 {
166 	uint32_t l1;
167 	unsigned long l2;
168 	unsigned int l1i, l2i, port;
169 	volatile shared_info_t *s = HYPERVISOR_shared_info;
170 	struct cpu_info *ci;
171 	int level;
172 
173 	ci = curcpu();
174 	level = ci->ci_ilevel;
175 
176 	// DDD printf("do_hypervisor_callback\n");
177 
178 #ifdef EARLY_DEBUG_EVENT
179 	if (xen_atomic_test_bit(&s->evtchn_pending[0], debug_port)) {
180 		xen_debug_handler(NULL);
181 		xen_atomic_clear_bit(&s->evtchn_pending[0], debug_port);
182 	}
183 #endif
184 
185 	while (s->vcpu_info[0].evtchn_upcall_pending) {
186 		s->vcpu_info[0].evtchn_upcall_pending = 0;
187 		/* NB. No need for a barrier here -- XCHG is a barrier
188 		 * on x86. */
189 #ifdef XEN3
190 		l1 = xen_atomic_xchg(&s->vcpu_info[0].evtchn_pending_sel, 0);
191 #else
192 		l1 = xen_atomic_xchg(&s->evtchn_pending_sel, 0);
193 #endif
194 		while ((l1i = ffs(l1)) != 0) {
195 			l1i--;
196 			l1 &= ~(1 << l1i);
197 
198 			l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
199 			/*
200 			 * mask and clear the pending events.
201 			 * Doing it here for all event that will be processed
202 			 * avoids a race with stipending (which can be called
203 			 * though evtchn_do_event->splx) that could cause an event to
204 			 * be both processed and marked pending.
205 			 */
206 			xen_atomic_setbits_l(&s->evtchn_mask[l1i], l2);
207 			xen_atomic_clearbits_l(&s->evtchn_pending[l1i], l2);
208 
209 			while ((l2i = ffs(l2)) != 0) {
210 				l2i--;
211 				l2 &= ~(1 << l2i);
212 
213 				port = (l1i << 5) + l2i;
214 #ifdef PORT_DEBUG
215 				if (port == PORT_DEBUG)
216 					printf("do_hypervisor_callback event %d\n", port);
217 #endif
218 				if (evtsource[port])
219 					call_evtchn_do_event(port, regs);
220 #ifdef DOM0OPS
221 				else
222 					xenevt_event(port);
223 #endif
224 			}
225 		}
226 	}
227 
228 #ifdef DIAGNOSTIC
229 	if (level != ci->ci_ilevel)
230 		printf("hypervisor done %08x level %d/%d ipending %08x\n",
231 #ifdef XEN3
232 		    (uint)HYPERVISOR_shared_info->vcpu_info[0].evtchn_pending_sel,
233 #else
234 		    (uint)HYPERVISOR_shared_info->evtchn_pending_sel,
235 #endif
236 		    level, ci->ci_ilevel, ci->ci_ipending);
237 #endif
238 }
239 
240 void
241 hypervisor_unmask_event(unsigned int ev)
242 {
243 	volatile shared_info_t *s = HYPERVISOR_shared_info;
244 #ifdef PORT_DEBUG
245 	if (ev == PORT_DEBUG)
246 		printf("hypervisor_unmask_event %d\n", ev);
247 #endif
248 
249 	xen_atomic_clear_bit(&s->evtchn_mask[0], ev);
250 	/*
251 	 * The following is basically the equivalent of
252 	 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose the
253 	 * interrupt edge' if the channel is masked.
254 	 */
255 	if (xen_atomic_test_bit(&s->evtchn_pending[0], ev) &&
256 #ifdef XEN3
257 	    !xen_atomic_test_and_set_bit(&s->vcpu_info[0].evtchn_pending_sel, ev>>5)) {
258 #else
259 	    !xen_atomic_test_and_set_bit(&s->evtchn_pending_sel, ev>>5)) {
260 #endif
261 		xen_atomic_set_bit(&s->vcpu_info[0].evtchn_upcall_pending, 0);
262 		if (!s->vcpu_info[0].evtchn_upcall_mask)
263 			hypervisor_force_callback();
264 	}
265 }
266 
267 void
268 hypervisor_mask_event(unsigned int ev)
269 {
270 	volatile shared_info_t *s = HYPERVISOR_shared_info;
271 #ifdef PORT_DEBUG
272 	if (ev == PORT_DEBUG)
273 		printf("hypervisor_mask_event %d\n", ev);
274 #endif
275 
276 	xen_atomic_set_bit(&s->evtchn_mask[0], ev);
277 }
278 
279 void
280 hypervisor_clear_event(unsigned int ev)
281 {
282 	volatile shared_info_t *s = HYPERVISOR_shared_info;
283 #ifdef PORT_DEBUG
284 	if (ev == PORT_DEBUG)
285 		printf("hypervisor_clear_event %d\n", ev);
286 #endif
287 
288 	xen_atomic_clear_bit(&s->evtchn_pending[0], ev);
289 }
290 
291 void
292 hypervisor_enable_ipl(unsigned int ipl)
293 {
294 	u_int32_t l1, l2;
295 	int l1i, l2i;
296 	struct cpu_info *ci = curcpu();
297 
298 	/*
299 	 * enable all events for ipl. As we only set an event in ipl_evt_mask
300 	 * for its lowest IPL, and pending IPLs are processed high to low,
301 	 * we know that all callback for this event have been processed.
302 	 */
303 
304 	l1 = ci->ci_isources[ipl]->ipl_evt_mask1;
305 	ci->ci_isources[ipl]->ipl_evt_mask1 = 0;
306 	while ((l1i = ffs(l1)) != 0) {
307 		l1i--;
308 		l1 &= ~(1 << l1i);
309 		l2 = ci->ci_isources[ipl]->ipl_evt_mask2[l1i];
310 		ci->ci_isources[ipl]->ipl_evt_mask2[l1i] = 0;
311 		while ((l2i = ffs(l2)) != 0) {
312 			int evtch;
313 
314 			l2i--;
315 			l2 &= ~(1 << l2i);
316 
317 			evtch = (l1i << 5) + l2i;
318 			hypervisor_enable_event(evtch);
319 		}
320 	}
321 }
322 
323 void
324 hypervisor_set_ipending(u_int32_t iplmask, int l1, int l2)
325 {
326 	int ipl;
327 	struct cpu_info *ci = curcpu();
328 
329 	/* set pending bit for the appropriate IPLs */
330 	ci->ci_ipending |= iplmask;
331 
332 	/*
333 	 * And set event pending bit for the lowest IPL. As IPL are handled
334 	 * from high to low, this ensure that all callbacks will have been
335 	 * called when we ack the event
336 	 */
337 	ipl = ffs(iplmask);
338 	KASSERT(ipl > 0);
339 	ipl--;
340 	ci->ci_isources[ipl]->ipl_evt_mask1 |= 1 << l1;
341 	ci->ci_isources[ipl]->ipl_evt_mask2[l1] |= 1 << l2;
342 }
343