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hypervisor_machdep.c revision 1.9
      1 /*	$NetBSD: hypervisor_machdep.c,v 1.9 2008/07/01 18:49:21 bouyer 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 1.9 2008/07/01 18:49:21 bouyer 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(void)
     79 {
     80 	unsigned long 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 	volatile struct vcpu_info *vci;
     86 	int ret;
     87 
     88 	ret = 0;
     89 	ci = curcpu();
     90 	vci = ci->ci_vcpu;
     91 
     92 #if 0
     93 	if (HYPERVISOR_shared_info->events)
     94 		printf("stipending events %08lx mask %08lx ilevel %d\n",
     95 		    HYPERVISOR_shared_info->events,
     96 		    HYPERVISOR_shared_info->events_mask, ci->ci_ilevel);
     97 #endif
     98 
     99 #ifdef EARLY_DEBUG_EVENT
    100 	if (xen_atomic_test_bit(&s->evtchn_pending[0], debug_port)) {
    101 		xen_debug_handler(NULL);
    102 		xen_atomic_clear_bit(&s->evtchn_pending[0], debug_port);
    103 	}
    104 #endif
    105 
    106 	/*
    107 	 * we're only called after STIC, so we know that we'll have to
    108 	 * STI at the end
    109 	 */
    110 	while (vci->evtchn_upcall_pending) {
    111 		cli();
    112 		vci->evtchn_upcall_pending = 0;
    113 		/* NB. No need for a barrier here -- XCHG is a barrier
    114 		 * on x86. */
    115 #ifdef XEN3
    116 		l1 = xen_atomic_xchg(&vci->evtchn_pending_sel, 0);
    117 #else
    118 		l1 = xen_atomic_xchg(&s->evtchn_pending_sel, 0);
    119 #endif
    120 		while ((l1i = xen_ffs(l1)) != 0) {
    121 			l1i--;
    122 			l1 &= ~(1UL << l1i);
    123 
    124 			l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
    125 			/*
    126 			 * mask and clear event. More efficient than calling
    127 			 * hypervisor_mask/clear_event for each event.
    128 			 */
    129 			xen_atomic_setbits_l(&s->evtchn_mask[l1i], l2);
    130 			xen_atomic_clearbits_l(&s->evtchn_pending[l1i], l2);
    131 			while ((l2i = xen_ffs(l2)) != 0) {
    132 				l2i--;
    133 				l2 &= ~(1UL << l2i);
    134 
    135 				port = (l1i << LONG_SHIFT) + l2i;
    136 				if (evtsource[port]) {
    137 					hypervisor_set_ipending(
    138 					    evtsource[port]->ev_imask,
    139 					    l1i, l2i);
    140 					evtsource[port]->ev_evcnt.ev_count++;
    141 					if (ret == 0 && ci->ci_ilevel <
    142 					    evtsource[port]->ev_maxlevel)
    143 						ret = 1;
    144 				}
    145 #ifdef DOM0OPS
    146 				else  {
    147 					/* set pending event */
    148 					xenevt_setipending(l1i, l2i);
    149 				}
    150 #endif
    151 			}
    152 		}
    153 		sti();
    154 	}
    155 
    156 #if 0
    157 	if (ci->ci_ipending & 0x1)
    158 		printf("stipending events %08lx mask %08lx ilevel %d ipending %08x\n",
    159 		    HYPERVISOR_shared_info->events,
    160 		    HYPERVISOR_shared_info->events_mask, ci->ci_ilevel,
    161 		    ci->ci_ipending);
    162 #endif
    163 
    164 	return (ret);
    165 }
    166 
    167 void
    168 do_hypervisor_callback(struct intrframe *regs)
    169 {
    170 	unsigned long l1;
    171 	unsigned long l2;
    172 	unsigned int l1i, l2i, port;
    173 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    174 	struct cpu_info *ci;
    175 	volatile struct vcpu_info *vci;
    176 	int level;
    177 
    178 	ci = curcpu();
    179 	vci = ci->ci_vcpu;
    180 	level = ci->ci_ilevel;
    181 
    182 	// DDD printf("do_hypervisor_callback\n");
    183 
    184 #ifdef EARLY_DEBUG_EVENT
    185 	if (xen_atomic_test_bit(&s->evtchn_pending[0], debug_port)) {
    186 		xen_debug_handler(NULL);
    187 		xen_atomic_clear_bit(&s->evtchn_pending[0], debug_port);
    188 	}
    189 #endif
    190 
    191 	while (vci->evtchn_upcall_pending) {
    192 		vci->evtchn_upcall_pending = 0;
    193 		/* NB. No need for a barrier here -- XCHG is a barrier
    194 		 * on x86. */
    195 #ifdef XEN3
    196 		l1 = xen_atomic_xchg(&vci->evtchn_pending_sel, 0);
    197 #else
    198 		l1 = xen_atomic_xchg(&s->evtchn_pending_sel, 0);
    199 #endif
    200 		while ((l1i = xen_ffs(l1)) != 0) {
    201 			l1i--;
    202 			l1 &= ~(1UL << l1i);
    203 
    204 			l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
    205 			/*
    206 			 * mask and clear the pending events.
    207 			 * Doing it here for all event that will be processed
    208 			 * avoids a race with stipending (which can be called
    209 			 * though evtchn_do_event->splx) that could cause an
    210 			 * event to be both processed and marked pending.
    211 			 */
    212 			xen_atomic_setbits_l(&s->evtchn_mask[l1i], l2);
    213 			xen_atomic_clearbits_l(&s->evtchn_pending[l1i], l2);
    214 
    215 			while ((l2i = xen_ffs(l2)) != 0) {
    216 				l2i--;
    217 				l2 &= ~(1UL << l2i);
    218 
    219 				port = (l1i << LONG_SHIFT) + l2i;
    220 #ifdef PORT_DEBUG
    221 				if (port == PORT_DEBUG)
    222 					printf("do_hypervisor_callback event %d\n", port);
    223 #endif
    224 				if (evtsource[port])
    225 					call_evtchn_do_event(port, regs);
    226 #ifdef DOM0OPS
    227 				else  {
    228 					if (ci->ci_ilevel < IPL_HIGH) {
    229 						/* fast path */
    230 						int oipl = ci->ci_ilevel;
    231 						ci->ci_ilevel = IPL_HIGH;
    232 						call_xenevt_event(port);
    233 						ci->ci_ilevel = oipl;
    234 					} else {
    235 						/* set pending event */
    236 						xenevt_setipending(l1i, l2i);
    237 					}
    238 				}
    239 #endif
    240 			}
    241 		}
    242 	}
    243 
    244 #ifdef DIAGNOSTIC
    245 	if (level != ci->ci_ilevel)
    246 		printf("hypervisor done %08x level %d/%d ipending %08x\n",
    247 #ifdef XEN3
    248 		    (uint)vci->evtchn_pending_sel,
    249 #else
    250 		    (uint)HYPERVISOR_shared_info->evtchn_pending_sel,
    251 #endif
    252 		    level, ci->ci_ilevel, ci->ci_ipending);
    253 #endif
    254 }
    255 
    256 void
    257 hypervisor_unmask_event(unsigned int ev)
    258 {
    259 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    260 	volatile struct vcpu_info *vci = curcpu()->ci_vcpu;
    261 
    262 #ifdef PORT_DEBUG
    263 	if (ev == PORT_DEBUG)
    264 		printf("hypervisor_unmask_event %d\n", ev);
    265 #endif
    266 
    267 	xen_atomic_clear_bit(&s->evtchn_mask[0], ev);
    268 	/*
    269 	 * The following is basically the equivalent of
    270 	 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose the
    271 	 * interrupt edge' if the channel is masked.
    272 	 */
    273 	if (xen_atomic_test_bit(&s->evtchn_pending[0], ev) &&
    274 #ifdef XEN3
    275 	    !xen_atomic_test_and_set_bit(&vci->evtchn_pending_sel, ev>>LONG_SHIFT)) {
    276 #else
    277 	    !xen_atomic_test_and_set_bit(&s->evtchn_pending_sel, ev>>LONG_SHIFT)) {
    278 #endif
    279 		xen_atomic_set_bit(&vci->evtchn_upcall_pending, 0);
    280 		if (!vci->evtchn_upcall_mask)
    281 			hypervisor_force_callback();
    282 	}
    283 }
    284 
    285 void
    286 hypervisor_mask_event(unsigned int ev)
    287 {
    288 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    289 #ifdef PORT_DEBUG
    290 	if (ev == PORT_DEBUG)
    291 		printf("hypervisor_mask_event %d\n", ev);
    292 #endif
    293 
    294 	xen_atomic_set_bit(&s->evtchn_mask[0], ev);
    295 }
    296 
    297 void
    298 hypervisor_clear_event(unsigned int ev)
    299 {
    300 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    301 #ifdef PORT_DEBUG
    302 	if (ev == PORT_DEBUG)
    303 		printf("hypervisor_clear_event %d\n", ev);
    304 #endif
    305 
    306 	xen_atomic_clear_bit(&s->evtchn_pending[0], ev);
    307 }
    308 
    309 void
    310 hypervisor_enable_ipl(unsigned int ipl)
    311 {
    312 	u_long l1, l2;
    313 	int l1i, l2i;
    314 	struct cpu_info *ci = curcpu();
    315 
    316 	/*
    317 	 * enable all events for ipl. As we only set an event in ipl_evt_mask
    318 	 * for its lowest IPL, and pending IPLs are processed high to low,
    319 	 * we know that all callback for this event have been processed.
    320 	 */
    321 
    322 	l1 = ci->ci_isources[ipl]->ipl_evt_mask1;
    323 	ci->ci_isources[ipl]->ipl_evt_mask1 = 0;
    324 	while ((l1i = xen_ffs(l1)) != 0) {
    325 		l1i--;
    326 		l1 &= ~(1UL << l1i);
    327 		l2 = ci->ci_isources[ipl]->ipl_evt_mask2[l1i];
    328 		ci->ci_isources[ipl]->ipl_evt_mask2[l1i] = 0;
    329 		while ((l2i = xen_ffs(l2)) != 0) {
    330 			int evtch;
    331 
    332 			l2i--;
    333 			l2 &= ~(1UL << l2i);
    334 
    335 			evtch = (l1i << LONG_SHIFT) + l2i;
    336 			hypervisor_enable_event(evtch);
    337 		}
    338 	}
    339 }
    340 
    341 void
    342 hypervisor_set_ipending(uint32_t iplmask, int l1, int l2)
    343 {
    344 	int ipl;
    345 	struct cpu_info *ci = curcpu();
    346 
    347 	/* set pending bit for the appropriate IPLs */
    348 	ci->ci_ipending |= iplmask;
    349 
    350 	/*
    351 	 * And set event pending bit for the lowest IPL. As IPL are handled
    352 	 * from high to low, this ensure that all callbacks will have been
    353 	 * called when we ack the event
    354 	 */
    355 	ipl = ffs(iplmask);
    356 	KASSERT(ipl > 0);
    357 	ipl--;
    358 	ci->ci_isources[ipl]->ipl_evt_mask1 |= 1UL << l1;
    359 	ci->ci_isources[ipl]->ipl_evt_mask2[l1] |= 1UL << l2;
    360 }
    361