1 /* $NetBSD: hypervisor_machdep.c,v 1.13 2009/10/23 02:32:34 snj 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 1.13 2009/10/23 02:32:34 snj 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 } 366 } 367 368 /* 369 * Generate the p2m_frame_list_list table, 370 * needed for guest save/restore 371 */ 372 static void 373 build_p2m_frame_list_list(void) 374 { 375 int fpp; /* number of page (frame) pointer per page */ 376 unsigned long max_pfn; 377 /* 378 * The p2m list is composed of three levels of indirection, 379 * each layer containing MFNs pointing to lower level pages 380 * The indirection is used to convert a given PFN to its MFN 381 * Each N level page can point to @fpp (N-1) level pages 382 * For example, for x86 32bit, we have: 383 * - PAGE_SIZE: 4096 bytes 384 * - fpp: 1024 (one L3 page can address 1024 L2 pages) 385 * A L1 page contains the list of MFN we are looking for 386 */ 387 max_pfn = xen_start_info.nr_pages; 388 fpp = PAGE_SIZE / sizeof(paddr_t); 389 390 /* we only need one L3 page */ 391 l3_p2m_page = kmem_alloc(PAGE_SIZE, KM_NOSLEEP); 392 if (l3_p2m_page == NULL) 393 panic("could not allocate memory for l3_p2m_page"); 394 395 /* 396 * Determine how many L2 pages we need for the mapping 397 * Each L2 can map a total of @fpp L1 pages 398 */ 399 l2_p2m_page_size = howmany(max_pfn, fpp); 400 401 l2_p2m_page = kmem_alloc(l2_p2m_page_size * PAGE_SIZE, KM_NOSLEEP); 402 if (l2_p2m_page == NULL) 403 panic("could not allocate memory for l2_p2m_page"); 404 405 /* We now have L3 and L2 pages ready, update L1 mapping */ 406 update_p2m_frame_list_list(); 407 408 } 409 410 /* 411 * Update the L1 p2m_frame_list_list mapping (during guest boot or resume) 412 */ 413 static void 414 update_p2m_frame_list_list(void) 415 { 416 int i; 417 int fpp; /* number of page (frame) pointer per page */ 418 unsigned long max_pfn; 419 420 max_pfn = xen_start_info.nr_pages; 421 fpp = PAGE_SIZE / sizeof(paddr_t); 422 423 for (i = 0; i < l2_p2m_page_size; i++) { 424 /* 425 * Each time we start a new L2 page, 426 * store its MFN in the L3 page 427 */ 428 if ((i % fpp) == 0) { 429 l3_p2m_page[i/fpp] = vtomfn( 430 (vaddr_t)&l2_p2m_page[i]); 431 } 432 /* 433 * we use a shortcut 434 * since @xpmap_phys_to_machine_mapping array 435 * already contains PFN to MFN mapping, we just 436 * set the l2_p2m_page MFN pointer to the MFN of the 437 * according frame of @xpmap_phys_to_machine_mapping 438 */ 439 l2_p2m_page[i] = vtomfn((vaddr_t) 440 &xpmap_phys_to_machine_mapping[i*fpp]); 441 } 442 443 HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = 444 vtomfn((vaddr_t)l3_p2m_page); 445 HYPERVISOR_shared_info->arch.max_pfn = max_pfn; 446 447 } 448