1 /* 2 * S390x MMU related functions 3 * 4 * Copyright (c) 2011 Alexander Graf 5 * Copyright (c) 2015 Thomas Huth, IBM Corporation 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 */ 17 18 #include "qemu/osdep.h" 19 #include "qemu/error-report.h" 20 #include "exec/address-spaces.h" 21 #include "cpu.h" 22 #include "internal.h" 23 #include "kvm_s390x.h" 24 #include "sysemu/kvm.h" 25 #include "exec/exec-all.h" 26 #include "trace.h" 27 #include "hw/s390x/storage-keys.h" 28 29 /* #define DEBUG_S390 */ 30 /* #define DEBUG_S390_PTE */ 31 /* #define DEBUG_S390_STDOUT */ 32 33 #ifdef DEBUG_S390 34 #ifdef DEBUG_S390_STDOUT 35 #define DPRINTF(fmt, ...) \ 36 do { fprintf(stderr, fmt, ## __VA_ARGS__); \ 37 if (qemu_log_separate()) qemu_log(fmt, ##__VA_ARGS__); } while (0) 38 #else 39 #define DPRINTF(fmt, ...) \ 40 do { qemu_log(fmt, ## __VA_ARGS__); } while (0) 41 #endif 42 #else 43 #define DPRINTF(fmt, ...) \ 44 do { } while (0) 45 #endif 46 47 #ifdef DEBUG_S390_PTE 48 #define PTE_DPRINTF DPRINTF 49 #else 50 #define PTE_DPRINTF(fmt, ...) \ 51 do { } while (0) 52 #endif 53 54 /* Fetch/store bits in the translation exception code: */ 55 #define FS_READ 0x800 56 #define FS_WRITE 0x400 57 58 static void trigger_access_exception(CPUS390XState *env, uint32_t type, 59 uint32_t ilen, uint64_t tec) 60 { 61 S390CPU *cpu = s390_env_get_cpu(env); 62 63 if (kvm_enabled()) { 64 kvm_s390_access_exception(cpu, type, tec); 65 } else { 66 CPUState *cs = CPU(cpu); 67 if (type != PGM_ADDRESSING) { 68 stq_phys(cs->as, env->psa + offsetof(LowCore, trans_exc_code), tec); 69 } 70 trigger_pgm_exception(env, type, ilen); 71 } 72 } 73 74 static void trigger_prot_fault(CPUS390XState *env, target_ulong vaddr, 75 uint64_t asc, int rw, bool exc) 76 { 77 uint64_t tec; 78 79 tec = vaddr | (rw == MMU_DATA_STORE ? FS_WRITE : FS_READ) | 4 | asc >> 46; 80 81 DPRINTF("%s: trans_exc_code=%016" PRIx64 "\n", __func__, tec); 82 83 if (!exc) { 84 return; 85 } 86 87 trigger_access_exception(env, PGM_PROTECTION, ILEN_AUTO, tec); 88 } 89 90 static void trigger_page_fault(CPUS390XState *env, target_ulong vaddr, 91 uint32_t type, uint64_t asc, int rw, bool exc) 92 { 93 int ilen = ILEN_AUTO; 94 uint64_t tec; 95 96 tec = vaddr | (rw == MMU_DATA_STORE ? FS_WRITE : FS_READ) | asc >> 46; 97 98 DPRINTF("%s: trans_exc_code=%016" PRIx64 "\n", __func__, tec); 99 100 if (!exc) { 101 return; 102 } 103 104 /* Code accesses have an undefined ilc. */ 105 if (rw == MMU_INST_FETCH) { 106 ilen = 2; 107 } 108 109 trigger_access_exception(env, type, ilen, tec); 110 } 111 112 /* check whether the address would be proteted by Low-Address Protection */ 113 static bool is_low_address(uint64_t addr) 114 { 115 return addr <= 511 || (addr >= 4096 && addr <= 4607); 116 } 117 118 /* check whether Low-Address Protection is enabled for mmu_translate() */ 119 static bool lowprot_enabled(const CPUS390XState *env, uint64_t asc) 120 { 121 if (!(env->cregs[0] & CR0_LOWPROT)) { 122 return false; 123 } 124 if (!(env->psw.mask & PSW_MASK_DAT)) { 125 return true; 126 } 127 128 /* Check the private-space control bit */ 129 switch (asc) { 130 case PSW_ASC_PRIMARY: 131 return !(env->cregs[1] & ASCE_PRIVATE_SPACE); 132 case PSW_ASC_SECONDARY: 133 return !(env->cregs[7] & ASCE_PRIVATE_SPACE); 134 case PSW_ASC_HOME: 135 return !(env->cregs[13] & ASCE_PRIVATE_SPACE); 136 default: 137 /* We don't support access register mode */ 138 error_report("unsupported addressing mode"); 139 exit(1); 140 } 141 } 142 143 /** 144 * Translate real address to absolute (= physical) 145 * address by taking care of the prefix mapping. 146 */ 147 target_ulong mmu_real2abs(CPUS390XState *env, target_ulong raddr) 148 { 149 if (raddr < 0x2000) { 150 return raddr + env->psa; /* Map the lowcore. */ 151 } else if (raddr >= env->psa && raddr < env->psa + 0x2000) { 152 return raddr - env->psa; /* Map the 0 page. */ 153 } 154 return raddr; 155 } 156 157 /* Decode page table entry (normal 4KB page) */ 158 static int mmu_translate_pte(CPUS390XState *env, target_ulong vaddr, 159 uint64_t asc, uint64_t pt_entry, 160 target_ulong *raddr, int *flags, int rw, bool exc) 161 { 162 if (pt_entry & PAGE_INVALID) { 163 DPRINTF("%s: PTE=0x%" PRIx64 " invalid\n", __func__, pt_entry); 164 trigger_page_fault(env, vaddr, PGM_PAGE_TRANS, asc, rw, exc); 165 return -1; 166 } 167 if (pt_entry & PAGE_RES0) { 168 trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw, exc); 169 return -1; 170 } 171 if (pt_entry & PAGE_RO) { 172 *flags &= ~PAGE_WRITE; 173 } 174 175 *raddr = pt_entry & ASCE_ORIGIN; 176 177 PTE_DPRINTF("%s: PTE=0x%" PRIx64 "\n", __func__, pt_entry); 178 179 return 0; 180 } 181 182 /* Decode segment table entry */ 183 static int mmu_translate_segment(CPUS390XState *env, target_ulong vaddr, 184 uint64_t asc, uint64_t st_entry, 185 target_ulong *raddr, int *flags, int rw, 186 bool exc) 187 { 188 CPUState *cs = CPU(s390_env_get_cpu(env)); 189 uint64_t origin, offs, pt_entry; 190 191 if (st_entry & SEGMENT_ENTRY_RO) { 192 *flags &= ~PAGE_WRITE; 193 } 194 195 if ((st_entry & SEGMENT_ENTRY_FC) && (env->cregs[0] & CR0_EDAT)) { 196 /* Decode EDAT1 segment frame absolute address (1MB page) */ 197 *raddr = (st_entry & 0xfffffffffff00000ULL) | (vaddr & 0xfffff); 198 PTE_DPRINTF("%s: SEG=0x%" PRIx64 "\n", __func__, st_entry); 199 return 0; 200 } 201 202 /* Look up 4KB page entry */ 203 origin = st_entry & SEGMENT_ENTRY_ORIGIN; 204 offs = (vaddr & VADDR_PX) >> 9; 205 pt_entry = ldq_phys(cs->as, origin + offs); 206 PTE_DPRINTF("%s: 0x%" PRIx64 " + 0x%" PRIx64 " => 0x%016" PRIx64 "\n", 207 __func__, origin, offs, pt_entry); 208 return mmu_translate_pte(env, vaddr, asc, pt_entry, raddr, flags, rw, exc); 209 } 210 211 /* Decode region table entries */ 212 static int mmu_translate_region(CPUS390XState *env, target_ulong vaddr, 213 uint64_t asc, uint64_t entry, int level, 214 target_ulong *raddr, int *flags, int rw, 215 bool exc) 216 { 217 CPUState *cs = CPU(s390_env_get_cpu(env)); 218 uint64_t origin, offs, new_entry; 219 const int pchks[4] = { 220 PGM_SEGMENT_TRANS, PGM_REG_THIRD_TRANS, 221 PGM_REG_SEC_TRANS, PGM_REG_FIRST_TRANS 222 }; 223 224 PTE_DPRINTF("%s: 0x%" PRIx64 "\n", __func__, entry); 225 226 origin = entry & REGION_ENTRY_ORIGIN; 227 offs = (vaddr >> (17 + 11 * level / 4)) & 0x3ff8; 228 229 new_entry = ldq_phys(cs->as, origin + offs); 230 PTE_DPRINTF("%s: 0x%" PRIx64 " + 0x%" PRIx64 " => 0x%016" PRIx64 "\n", 231 __func__, origin, offs, new_entry); 232 233 if ((new_entry & REGION_ENTRY_INV) != 0) { 234 DPRINTF("%s: invalid region\n", __func__); 235 trigger_page_fault(env, vaddr, pchks[level / 4], asc, rw, exc); 236 return -1; 237 } 238 239 if ((new_entry & REGION_ENTRY_TYPE_MASK) != level) { 240 trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw, exc); 241 return -1; 242 } 243 244 if (level == ASCE_TYPE_SEGMENT) { 245 return mmu_translate_segment(env, vaddr, asc, new_entry, raddr, flags, 246 rw, exc); 247 } 248 249 /* Check region table offset and length */ 250 offs = (vaddr >> (28 + 11 * (level - 4) / 4)) & 3; 251 if (offs < ((new_entry & REGION_ENTRY_TF) >> 6) 252 || offs > (new_entry & REGION_ENTRY_LENGTH)) { 253 DPRINTF("%s: invalid offset or len (%lx)\n", __func__, new_entry); 254 trigger_page_fault(env, vaddr, pchks[level / 4 - 1], asc, rw, exc); 255 return -1; 256 } 257 258 if ((env->cregs[0] & CR0_EDAT) && (new_entry & REGION_ENTRY_RO)) { 259 *flags &= ~PAGE_WRITE; 260 } 261 262 /* yet another region */ 263 return mmu_translate_region(env, vaddr, asc, new_entry, level - 4, 264 raddr, flags, rw, exc); 265 } 266 267 static int mmu_translate_asce(CPUS390XState *env, target_ulong vaddr, 268 uint64_t asc, uint64_t asce, target_ulong *raddr, 269 int *flags, int rw, bool exc) 270 { 271 int level; 272 int r; 273 274 if (asce & ASCE_REAL_SPACE) { 275 /* direct mapping */ 276 *raddr = vaddr; 277 return 0; 278 } 279 280 level = asce & ASCE_TYPE_MASK; 281 switch (level) { 282 case ASCE_TYPE_REGION1: 283 if ((vaddr >> 62) > (asce & ASCE_TABLE_LENGTH)) { 284 trigger_page_fault(env, vaddr, PGM_REG_FIRST_TRANS, asc, rw, exc); 285 return -1; 286 } 287 break; 288 case ASCE_TYPE_REGION2: 289 if (vaddr & 0xffe0000000000000ULL) { 290 DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64 291 " 0xffe0000000000000ULL\n", __func__, vaddr); 292 trigger_page_fault(env, vaddr, PGM_ASCE_TYPE, asc, rw, exc); 293 return -1; 294 } 295 if ((vaddr >> 51 & 3) > (asce & ASCE_TABLE_LENGTH)) { 296 trigger_page_fault(env, vaddr, PGM_REG_SEC_TRANS, asc, rw, exc); 297 return -1; 298 } 299 break; 300 case ASCE_TYPE_REGION3: 301 if (vaddr & 0xfffffc0000000000ULL) { 302 DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64 303 " 0xfffffc0000000000ULL\n", __func__, vaddr); 304 trigger_page_fault(env, vaddr, PGM_ASCE_TYPE, asc, rw, exc); 305 return -1; 306 } 307 if ((vaddr >> 40 & 3) > (asce & ASCE_TABLE_LENGTH)) { 308 trigger_page_fault(env, vaddr, PGM_REG_THIRD_TRANS, asc, rw, exc); 309 return -1; 310 } 311 break; 312 case ASCE_TYPE_SEGMENT: 313 if (vaddr & 0xffffffff80000000ULL) { 314 DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64 315 " 0xffffffff80000000ULL\n", __func__, vaddr); 316 trigger_page_fault(env, vaddr, PGM_ASCE_TYPE, asc, rw, exc); 317 return -1; 318 } 319 if ((vaddr >> 29 & 3) > (asce & ASCE_TABLE_LENGTH)) { 320 trigger_page_fault(env, vaddr, PGM_SEGMENT_TRANS, asc, rw, exc); 321 return -1; 322 } 323 break; 324 } 325 326 r = mmu_translate_region(env, vaddr, asc, asce, level, raddr, flags, rw, 327 exc); 328 if (!r && rw == MMU_DATA_STORE && !(*flags & PAGE_WRITE)) { 329 trigger_prot_fault(env, vaddr, asc, rw, exc); 330 return -1; 331 } 332 333 return r; 334 } 335 336 /** 337 * Translate a virtual (logical) address into a physical (absolute) address. 338 * @param vaddr the virtual address 339 * @param rw 0 = read, 1 = write, 2 = code fetch 340 * @param asc address space control (one of the PSW_ASC_* modes) 341 * @param raddr the translated address is stored to this pointer 342 * @param flags the PAGE_READ/WRITE/EXEC flags are stored to this pointer 343 * @param exc true = inject a program check if a fault occurred 344 * @return 0 if the translation was successful, -1 if a fault occurred 345 */ 346 int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc, 347 target_ulong *raddr, int *flags, bool exc) 348 { 349 static S390SKeysState *ss; 350 static S390SKeysClass *skeyclass; 351 int r = -1; 352 uint8_t key; 353 354 if (unlikely(!ss)) { 355 ss = s390_get_skeys_device(); 356 skeyclass = S390_SKEYS_GET_CLASS(ss); 357 } 358 359 *flags = PAGE_READ | PAGE_WRITE | PAGE_EXEC; 360 if (is_low_address(vaddr & TARGET_PAGE_MASK) && lowprot_enabled(env, asc)) { 361 /* 362 * If any part of this page is currently protected, make sure the 363 * TLB entry will not be reused. 364 * 365 * As the protected range is always the first 512 bytes of the 366 * two first pages, we are able to catch all writes to these areas 367 * just by looking at the start address (triggering the tlb miss). 368 */ 369 *flags |= PAGE_WRITE_INV; 370 if (is_low_address(vaddr) && rw == MMU_DATA_STORE) { 371 if (exc) { 372 trigger_access_exception(env, PGM_PROTECTION, ILEN_AUTO, 0); 373 } 374 return -EACCES; 375 } 376 } 377 378 vaddr &= TARGET_PAGE_MASK; 379 380 if (!(env->psw.mask & PSW_MASK_DAT)) { 381 *raddr = vaddr; 382 r = 0; 383 goto out; 384 } 385 386 switch (asc) { 387 case PSW_ASC_PRIMARY: 388 PTE_DPRINTF("%s: asc=primary\n", __func__); 389 r = mmu_translate_asce(env, vaddr, asc, env->cregs[1], raddr, flags, 390 rw, exc); 391 break; 392 case PSW_ASC_HOME: 393 PTE_DPRINTF("%s: asc=home\n", __func__); 394 r = mmu_translate_asce(env, vaddr, asc, env->cregs[13], raddr, flags, 395 rw, exc); 396 break; 397 case PSW_ASC_SECONDARY: 398 PTE_DPRINTF("%s: asc=secondary\n", __func__); 399 /* 400 * Instruction: Primary 401 * Data: Secondary 402 */ 403 if (rw == MMU_INST_FETCH) { 404 r = mmu_translate_asce(env, vaddr, PSW_ASC_PRIMARY, env->cregs[1], 405 raddr, flags, rw, exc); 406 *flags &= ~(PAGE_READ | PAGE_WRITE); 407 } else { 408 r = mmu_translate_asce(env, vaddr, PSW_ASC_SECONDARY, env->cregs[7], 409 raddr, flags, rw, exc); 410 *flags &= ~(PAGE_EXEC); 411 } 412 break; 413 case PSW_ASC_ACCREG: 414 default: 415 hw_error("guest switched to unknown asc mode\n"); 416 break; 417 } 418 419 out: 420 /* Convert real address -> absolute address */ 421 *raddr = mmu_real2abs(env, *raddr); 422 423 if (r == 0 && *raddr < ram_size) { 424 if (skeyclass->get_skeys(ss, *raddr / TARGET_PAGE_SIZE, 1, &key)) { 425 trace_get_skeys_nonzero(r); 426 return 0; 427 } 428 429 if (*flags & PAGE_READ) { 430 key |= SK_R; 431 } 432 433 if (*flags & PAGE_WRITE) { 434 key |= SK_C; 435 } 436 437 if (skeyclass->set_skeys(ss, *raddr / TARGET_PAGE_SIZE, 1, &key)) { 438 trace_set_skeys_nonzero(r); 439 return 0; 440 } 441 } 442 443 return r; 444 } 445 446 /** 447 * translate_pages: Translate a set of consecutive logical page addresses 448 * to absolute addresses. This function is used for TCG and old KVM without 449 * the MEMOP interface. 450 */ 451 static int translate_pages(S390CPU *cpu, vaddr addr, int nr_pages, 452 target_ulong *pages, bool is_write) 453 { 454 uint64_t asc = cpu->env.psw.mask & PSW_MASK_ASC; 455 CPUS390XState *env = &cpu->env; 456 int ret, i, pflags; 457 458 for (i = 0; i < nr_pages; i++) { 459 ret = mmu_translate(env, addr, is_write, asc, &pages[i], &pflags, true); 460 if (ret) { 461 return ret; 462 } 463 if (!address_space_access_valid(&address_space_memory, pages[i], 464 TARGET_PAGE_SIZE, is_write, 465 MEMTXATTRS_UNSPECIFIED)) { 466 trigger_access_exception(env, PGM_ADDRESSING, ILEN_AUTO, 0); 467 return -EFAULT; 468 } 469 addr += TARGET_PAGE_SIZE; 470 } 471 472 return 0; 473 } 474 475 /** 476 * s390_cpu_virt_mem_rw: 477 * @laddr: the logical start address 478 * @ar: the access register number 479 * @hostbuf: buffer in host memory. NULL = do only checks w/o copying 480 * @len: length that should be transferred 481 * @is_write: true = write, false = read 482 * Returns: 0 on success, non-zero if an exception occurred 483 * 484 * Copy from/to guest memory using logical addresses. Note that we inject a 485 * program interrupt in case there is an error while accessing the memory. 486 * 487 * This function will always return (also for TCG), make sure to call 488 * s390_cpu_virt_mem_handle_exc() to properly exit the CPU loop. 489 */ 490 int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, uint8_t ar, void *hostbuf, 491 int len, bool is_write) 492 { 493 int currlen, nr_pages, i; 494 target_ulong *pages; 495 int ret; 496 497 if (kvm_enabled()) { 498 ret = kvm_s390_mem_op(cpu, laddr, ar, hostbuf, len, is_write); 499 if (ret >= 0) { 500 return ret; 501 } 502 } 503 504 nr_pages = (((laddr & ~TARGET_PAGE_MASK) + len - 1) >> TARGET_PAGE_BITS) 505 + 1; 506 pages = g_malloc(nr_pages * sizeof(*pages)); 507 508 ret = translate_pages(cpu, laddr, nr_pages, pages, is_write); 509 if (ret == 0 && hostbuf != NULL) { 510 /* Copy data by stepping through the area page by page */ 511 for (i = 0; i < nr_pages; i++) { 512 currlen = MIN(len, TARGET_PAGE_SIZE - (laddr % TARGET_PAGE_SIZE)); 513 cpu_physical_memory_rw(pages[i] | (laddr & ~TARGET_PAGE_MASK), 514 hostbuf, currlen, is_write); 515 laddr += currlen; 516 hostbuf += currlen; 517 len -= currlen; 518 } 519 } 520 521 g_free(pages); 522 return ret; 523 } 524 525 void s390_cpu_virt_mem_handle_exc(S390CPU *cpu, uintptr_t ra) 526 { 527 /* KVM will handle the interrupt automatically, TCG has to exit the TB */ 528 #ifdef CONFIG_TCG 529 if (tcg_enabled()) { 530 cpu_loop_exit_restore(CPU(cpu), ra); 531 } 532 #endif 533 } 534 535 /** 536 * Translate a real address into a physical (absolute) address. 537 * @param raddr the real address 538 * @param rw 0 = read, 1 = write, 2 = code fetch 539 * @param addr the translated address is stored to this pointer 540 * @param flags the PAGE_READ/WRITE/EXEC flags are stored to this pointer 541 * @return 0 if the translation was successful, < 0 if a fault occurred 542 */ 543 int mmu_translate_real(CPUS390XState *env, target_ulong raddr, int rw, 544 target_ulong *addr, int *flags) 545 { 546 const bool lowprot_enabled = env->cregs[0] & CR0_LOWPROT; 547 548 *flags = PAGE_READ | PAGE_WRITE | PAGE_EXEC; 549 if (is_low_address(raddr & TARGET_PAGE_MASK) && lowprot_enabled) { 550 /* see comment in mmu_translate() how this works */ 551 *flags |= PAGE_WRITE_INV; 552 if (is_low_address(raddr) && rw == MMU_DATA_STORE) { 553 trigger_access_exception(env, PGM_PROTECTION, ILEN_AUTO, 0); 554 return -EACCES; 555 } 556 } 557 558 *addr = mmu_real2abs(env, raddr & TARGET_PAGE_MASK); 559 560 /* TODO: storage key handling */ 561 return 0; 562 } 563