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hypervisor_machdep.c revision 1.11.8.6
      1 /*	$NetBSD: hypervisor_machdep.c,v 1.11.8.6 2011/03/30 23:15:05 jym 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  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 /******************************************************************************
     30  * hypervisor.c
     31  *
     32  * Communication to/from hypervisor.
     33  *
     34  * Copyright (c) 2002-2004, K A Fraser
     35  *
     36  * Permission is hereby granted, free of charge, to any person obtaining a copy
     37  * of this software and associated documentation files (the "Software"), to
     38  * deal in the Software without restriction, including without limitation the
     39  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     40  * sell copies of the Software, and to permit persons to whom the Software is
     41  * furnished to do so, subject to the following conditions:
     42  *
     43  * The above copyright notice and this permission notice shall be included in
     44  * all copies or substantial portions of the Software.
     45  *
     46  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     47  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     48  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     49  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     50  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     51  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     52  * DEALINGS IN THE SOFTWARE.
     53  */
     54 
     55 
     56 #include <sys/cdefs.h>
     57 __KERNEL_RCSID(0, "$NetBSD: hypervisor_machdep.c,v 1.11.8.6 2011/03/30 23:15:05 jym Exp $");
     58 
     59 #include <sys/param.h>
     60 #include <sys/systm.h>
     61 #include <sys/kmem.h>
     62 
     63 #include <uvm/uvm_extern.h>
     64 
     65 #include <machine/vmparam.h>
     66 #include <machine/pmap.h>
     67 
     68 #include <xen/xen.h>
     69 #include <xen/hypervisor.h>
     70 #include <xen/evtchn.h>
     71 #include <xen/xenpmap.h>
     72 
     73 #include "opt_xen.h"
     74 
     75 /*
     76  * arch-dependent p2m frame lists list (L3 and L2)
     77  * used by Xen for save/restore mappings
     78  */
     79 static unsigned long * l3_p2m_page;
     80 static unsigned long * l2_p2m_page;
     81 static int l2_p2m_page_size; /* size of L2 page, in pages */
     82 
     83 static void build_p2m_frame_list_list(void);
     84 static void update_p2m_frame_list_list(void);
     85 
     86 // #define PORT_DEBUG 4
     87 // #define EARLY_DEBUG_EVENT
     88 
     89 int stipending(void);
     90 int
     91 stipending(void)
     92 {
     93 	unsigned long l1;
     94 	unsigned long l2;
     95 	unsigned int l1i, l2i, port;
     96 	volatile shared_info_t *s = HYPERVISOR_shared_info;
     97 	struct cpu_info *ci;
     98 	volatile struct vcpu_info *vci;
     99 	int ret;
    100 
    101 	ret = 0;
    102 	ci = curcpu();
    103 	vci = ci->ci_vcpu;
    104 
    105 #if 0
    106 	if (HYPERVISOR_shared_info->events)
    107 		printf("stipending events %08lx mask %08lx ilevel %d\n",
    108 		    HYPERVISOR_shared_info->events,
    109 		    HYPERVISOR_shared_info->events_mask, ci->ci_ilevel);
    110 #endif
    111 
    112 #ifdef EARLY_DEBUG_EVENT
    113 	if (xen_atomic_test_bit(&s->evtchn_pending[0], debug_port)) {
    114 		xen_debug_handler(NULL);
    115 		xen_atomic_clear_bit(&s->evtchn_pending[0], debug_port);
    116 	}
    117 #endif
    118 
    119 	/*
    120 	 * we're only called after STIC, so we know that we'll have to
    121 	 * STI at the end
    122 	 */
    123 	while (vci->evtchn_upcall_pending) {
    124 		cli();
    125 		vci->evtchn_upcall_pending = 0;
    126 		/* NB. No need for a barrier here -- XCHG is a barrier
    127 		 * on x86. */
    128 		l1 = xen_atomic_xchg(&vci->evtchn_pending_sel, 0);
    129 		while ((l1i = xen_ffs(l1)) != 0) {
    130 			l1i--;
    131 			l1 &= ~(1UL << l1i);
    132 
    133 			l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
    134 			/*
    135 			 * mask and clear event. More efficient than calling
    136 			 * hypervisor_mask/clear_event for each event.
    137 			 */
    138 			xen_atomic_setbits_l(&s->evtchn_mask[l1i], l2);
    139 			xen_atomic_clearbits_l(&s->evtchn_pending[l1i], l2);
    140 			while ((l2i = xen_ffs(l2)) != 0) {
    141 				l2i--;
    142 				l2 &= ~(1UL << l2i);
    143 
    144 				port = (l1i << LONG_SHIFT) + l2i;
    145 				if (evtsource[port]) {
    146 					hypervisor_set_ipending(
    147 					    evtsource[port]->ev_imask,
    148 					    l1i, l2i);
    149 					evtsource[port]->ev_evcnt.ev_count++;
    150 					if (ret == 0 && ci->ci_ilevel <
    151 					    evtsource[port]->ev_maxlevel)
    152 						ret = 1;
    153 				}
    154 #ifdef DOM0OPS
    155 				else  {
    156 					/* set pending event */
    157 					xenevt_setipending(l1i, l2i);
    158 				}
    159 #endif
    160 			}
    161 		}
    162 		sti();
    163 	}
    164 
    165 #if 0
    166 	if (ci->ci_ipending & 0x1)
    167 		printf("stipending events %08lx mask %08lx ilevel %d ipending %08x\n",
    168 		    HYPERVISOR_shared_info->events,
    169 		    HYPERVISOR_shared_info->events_mask, ci->ci_ilevel,
    170 		    ci->ci_ipending);
    171 #endif
    172 
    173 	return (ret);
    174 }
    175 
    176 void
    177 do_hypervisor_callback(struct intrframe *regs)
    178 {
    179 	unsigned long l1;
    180 	unsigned long l2;
    181 	unsigned int l1i, l2i, port;
    182 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    183 	struct cpu_info *ci;
    184 	volatile struct vcpu_info *vci;
    185 	int level;
    186 
    187 	ci = curcpu();
    188 	vci = ci->ci_vcpu;
    189 	level = ci->ci_ilevel;
    190 
    191 	// DDD printf("do_hypervisor_callback\n");
    192 
    193 #ifdef EARLY_DEBUG_EVENT
    194 	if (xen_atomic_test_bit(&s->evtchn_pending[0], debug_port)) {
    195 		xen_debug_handler(NULL);
    196 		xen_atomic_clear_bit(&s->evtchn_pending[0], debug_port);
    197 	}
    198 #endif
    199 
    200 	while (vci->evtchn_upcall_pending) {
    201 		vci->evtchn_upcall_pending = 0;
    202 		/* NB. No need for a barrier here -- XCHG is a barrier
    203 		 * on x86. */
    204 		l1 = xen_atomic_xchg(&vci->evtchn_pending_sel, 0);
    205 		while ((l1i = xen_ffs(l1)) != 0) {
    206 			l1i--;
    207 			l1 &= ~(1UL << l1i);
    208 
    209 			l2 = s->evtchn_pending[l1i] & ~s->evtchn_mask[l1i];
    210 			/*
    211 			 * mask and clear the pending events.
    212 			 * Doing it here for all event that will be processed
    213 			 * avoids a race with stipending (which can be called
    214 			 * though evtchn_do_event->splx) that could cause an
    215 			 * event to be both processed and marked pending.
    216 			 */
    217 			xen_atomic_setbits_l(&s->evtchn_mask[l1i], l2);
    218 			xen_atomic_clearbits_l(&s->evtchn_pending[l1i], l2);
    219 
    220 			while ((l2i = xen_ffs(l2)) != 0) {
    221 				l2i--;
    222 				l2 &= ~(1UL << l2i);
    223 
    224 				port = (l1i << LONG_SHIFT) + l2i;
    225 #ifdef PORT_DEBUG
    226 				if (port == PORT_DEBUG)
    227 					printf("do_hypervisor_callback event %d\n", port);
    228 #endif
    229 				if (evtsource[port])
    230 					call_evtchn_do_event(port, regs);
    231 #ifdef DOM0OPS
    232 				else  {
    233 					if (ci->ci_ilevel < IPL_HIGH) {
    234 						/* fast path */
    235 						int oipl = ci->ci_ilevel;
    236 						ci->ci_ilevel = IPL_HIGH;
    237 						call_xenevt_event(port);
    238 						ci->ci_ilevel = oipl;
    239 					} else {
    240 						/* set pending event */
    241 						xenevt_setipending(l1i, l2i);
    242 					}
    243 				}
    244 #endif
    245 			}
    246 		}
    247 	}
    248 
    249 #ifdef DIAGNOSTIC
    250 	if (level != ci->ci_ilevel)
    251 		printf("hypervisor done %08x level %d/%d ipending %08x\n",
    252 		    (uint)vci->evtchn_pending_sel,
    253 		    level, ci->ci_ilevel, ci->ci_ipending);
    254 #endif
    255 }
    256 
    257 void
    258 hypervisor_unmask_event(unsigned int ev)
    259 {
    260 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    261 	volatile struct vcpu_info *vci = curcpu()->ci_vcpu;
    262 
    263 #ifdef PORT_DEBUG
    264 	if (ev == PORT_DEBUG)
    265 		printf("hypervisor_unmask_event %d\n", ev);
    266 #endif
    267 
    268 	xen_atomic_clear_bit(&s->evtchn_mask[0], ev);
    269 	/*
    270 	 * The following is basically the equivalent of
    271 	 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose the
    272 	 * interrupt edge' if the channel is masked.
    273 	 */
    274 	if (xen_atomic_test_bit(&s->evtchn_pending[0], ev) &&
    275 	    !xen_atomic_test_and_set_bit(&vci->evtchn_pending_sel, ev>>LONG_SHIFT)) {
    276 		xen_atomic_set_bit(&vci->evtchn_upcall_pending, 0);
    277 		if (!vci->evtchn_upcall_mask)
    278 			hypervisor_force_callback();
    279 	}
    280 }
    281 
    282 void
    283 hypervisor_mask_event(unsigned int ev)
    284 {
    285 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    286 #ifdef PORT_DEBUG
    287 	if (ev == PORT_DEBUG)
    288 		printf("hypervisor_mask_event %d\n", ev);
    289 #endif
    290 
    291 	xen_atomic_set_bit(&s->evtchn_mask[0], ev);
    292 }
    293 
    294 void
    295 hypervisor_clear_event(unsigned int ev)
    296 {
    297 	volatile shared_info_t *s = HYPERVISOR_shared_info;
    298 #ifdef PORT_DEBUG
    299 	if (ev == PORT_DEBUG)
    300 		printf("hypervisor_clear_event %d\n", ev);
    301 #endif
    302 
    303 	xen_atomic_clear_bit(&s->evtchn_pending[0], ev);
    304 }
    305 
    306 void
    307 hypervisor_enable_ipl(unsigned int ipl)
    308 {
    309 	u_long l1, l2;
    310 	int l1i, l2i;
    311 	struct cpu_info *ci = curcpu();
    312 
    313 	/*
    314 	 * enable all events for ipl. As we only set an event in ipl_evt_mask
    315 	 * for its lowest IPL, and pending IPLs are processed high to low,
    316 	 * we know that all callback for this event have been processed.
    317 	 */
    318 
    319 	l1 = ci->ci_isources[ipl]->ipl_evt_mask1;
    320 	ci->ci_isources[ipl]->ipl_evt_mask1 = 0;
    321 	while ((l1i = xen_ffs(l1)) != 0) {
    322 		l1i--;
    323 		l1 &= ~(1UL << l1i);
    324 		l2 = ci->ci_isources[ipl]->ipl_evt_mask2[l1i];
    325 		ci->ci_isources[ipl]->ipl_evt_mask2[l1i] = 0;
    326 		while ((l2i = xen_ffs(l2)) != 0) {
    327 			int evtch;
    328 
    329 			l2i--;
    330 			l2 &= ~(1UL << l2i);
    331 
    332 			evtch = (l1i << LONG_SHIFT) + l2i;
    333 			hypervisor_enable_event(evtch);
    334 		}
    335 	}
    336 }
    337 
    338 void
    339 hypervisor_set_ipending(uint32_t iplmask, int l1, int l2)
    340 {
    341 	int ipl;
    342 	struct cpu_info *ci = curcpu();
    343 
    344 	/* set pending bit for the appropriate IPLs */
    345 	ci->ci_ipending |= iplmask;
    346 
    347 	/*
    348 	 * And set event pending bit for the lowest IPL. As IPL are handled
    349 	 * from high to low, this ensure that all callbacks will have been
    350 	 * called when we ack the event
    351 	 */
    352 	ipl = ffs(iplmask);
    353 	KASSERT(ipl > 0);
    354 	ipl--;
    355 	ci->ci_isources[ipl]->ipl_evt_mask1 |= 1UL << l1;
    356 	ci->ci_isources[ipl]->ipl_evt_mask2[l1] |= 1UL << l2;
    357 }
    358 
    359 void
    360 hypervisor_machdep_attach(void)
    361 {
    362  	/* dom0 does not require the arch-dependent P2M translation table */
    363 	if ( !xendomain_is_dom0() ) {
    364 		build_p2m_frame_list_list();
    365 		sysctl_xen_sleepstate_setup();
    366 	}
    367 }
    368 
    369 void
    370 hypervisor_machdep_resume(void)
    371 {
    372 	/* dom0 does not require the arch-dependent P2M translation table */
    373 	if ( !(xen_start_info.flags & SIF_INITDOMAIN) )
    374 		update_p2m_frame_list_list();
    375 }
    376 
    377 /*
    378  * Generate the p2m_frame_list_list table,
    379  * needed for guest save/restore
    380  */
    381 static void
    382 build_p2m_frame_list_list(void)
    383 {
    384         int fpp; /* number of page (frame) pointer per page */
    385         unsigned long max_pfn;
    386         /*
    387          * The p2m list is composed of three levels of indirection,
    388          * each layer containing MFNs pointing to lower level pages
    389          * The indirection is used to convert a given PFN to its MFN
    390          * Each N level page can point to @fpp (N-1) level pages
    391          * For example, for x86 32bit, we have:
    392          * - PAGE_SIZE: 4096 bytes
    393          * - fpp: 1024 (one L3 page can address 1024 L2 pages)
    394          * A L1 page contains the list of MFN we are looking for
    395          */
    396         max_pfn = xen_start_info.nr_pages;
    397         fpp = PAGE_SIZE / sizeof(xen_pfn_t);
    398 
    399         /* we only need one L3 page */
    400         l3_p2m_page = (vaddr_t *)uvm_km_alloc(kernel_map, PAGE_SIZE,
    401 	    PAGE_SIZE, UVM_KMF_WIRED | UVM_KMF_NOWAIT);
    402         if (l3_p2m_page == NULL)
    403                 panic("could not allocate memory for l3_p2m_page");
    404 
    405         /*
    406          * Determine how many L2 pages we need for the mapping
    407          * Each L2 can map a total of @fpp L1 pages
    408          */
    409         l2_p2m_page_size = howmany(max_pfn, fpp);
    410 
    411         l2_p2m_page = (vaddr_t *)uvm_km_alloc(kernel_map,
    412             l2_p2m_page_size * PAGE_SIZE,
    413             PAGE_SIZE, UVM_KMF_WIRED | UVM_KMF_NOWAIT);
    414         if (l2_p2m_page == NULL)
    415                 panic("could not allocate memory for l2_p2m_page");
    416 
    417         /* We now have L3 and L2 pages ready, update L1 mapping */
    418         update_p2m_frame_list_list();
    419 
    420 }
    421 
    422 /*
    423  * Update the L1 p2m_frame_list_list mapping (during guest boot or resume)
    424  */
    425 static void
    426 update_p2m_frame_list_list(void)
    427 {
    428         int i;
    429         int fpp; /* number of page (frame) pointer per page */
    430         unsigned long max_pfn;
    431 
    432         max_pfn = xen_start_info.nr_pages;
    433         fpp = PAGE_SIZE / sizeof(xen_pfn_t);
    434 
    435         for (i = 0; i < l2_p2m_page_size; i++) {
    436                 /*
    437                  * Each time we start a new L2 page,
    438                  * store its MFN in the L3 page
    439                  */
    440                 if ((i % fpp) == 0) {
    441                         l3_p2m_page[i/fpp] = vtomfn(
    442                                 (vaddr_t)&l2_p2m_page[i]);
    443                 }
    444                 /*
    445                  * we use a shortcut
    446                  * since @xpmap_phys_to_machine_mapping array
    447                  * already contains PFN to MFN mapping, we just
    448                  * set the l2_p2m_page MFN pointer to the MFN of the
    449                  * according frame of @xpmap_phys_to_machine_mapping
    450                  */
    451                 l2_p2m_page[i] = vtomfn((vaddr_t)
    452                         &xpmap_phys_to_machine_mapping[i*fpp]);
    453         }
    454 
    455         HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
    456                                         vtomfn((vaddr_t)l3_p2m_page);
    457         HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
    458 
    459 }
    460