1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * guest access functions 4 * 5 * Copyright IBM Corp. 2014 6 * 7 */ 8 9 #include <linux/vmalloc.h> 10 #include <linux/mm_types.h> 11 #include <linux/err.h> 12 #include <linux/pgtable.h> 13 14 #include <asm/gmap.h> 15 #include "kvm-s390.h" 16 #include "gaccess.h" 17 #include <asm/switch_to.h> 18 19 union asce { 20 unsigned long val; 21 struct { 22 unsigned long origin : 52; /* Region- or Segment-Table Origin */ 23 unsigned long : 2; 24 unsigned long g : 1; /* Subspace Group Control */ 25 unsigned long p : 1; /* Private Space Control */ 26 unsigned long s : 1; /* Storage-Alteration-Event Control */ 27 unsigned long x : 1; /* Space-Switch-Event Control */ 28 unsigned long r : 1; /* Real-Space Control */ 29 unsigned long : 1; 30 unsigned long dt : 2; /* Designation-Type Control */ 31 unsigned long tl : 2; /* Region- or Segment-Table Length */ 32 }; 33 }; 34 35 enum { 36 ASCE_TYPE_SEGMENT = 0, 37 ASCE_TYPE_REGION3 = 1, 38 ASCE_TYPE_REGION2 = 2, 39 ASCE_TYPE_REGION1 = 3 40 }; 41 42 union region1_table_entry { 43 unsigned long val; 44 struct { 45 unsigned long rto: 52;/* Region-Table Origin */ 46 unsigned long : 2; 47 unsigned long p : 1; /* DAT-Protection Bit */ 48 unsigned long : 1; 49 unsigned long tf : 2; /* Region-Second-Table Offset */ 50 unsigned long i : 1; /* Region-Invalid Bit */ 51 unsigned long : 1; 52 unsigned long tt : 2; /* Table-Type Bits */ 53 unsigned long tl : 2; /* Region-Second-Table Length */ 54 }; 55 }; 56 57 union region2_table_entry { 58 unsigned long val; 59 struct { 60 unsigned long rto: 52;/* Region-Table Origin */ 61 unsigned long : 2; 62 unsigned long p : 1; /* DAT-Protection Bit */ 63 unsigned long : 1; 64 unsigned long tf : 2; /* Region-Third-Table Offset */ 65 unsigned long i : 1; /* Region-Invalid Bit */ 66 unsigned long : 1; 67 unsigned long tt : 2; /* Table-Type Bits */ 68 unsigned long tl : 2; /* Region-Third-Table Length */ 69 }; 70 }; 71 72 struct region3_table_entry_fc0 { 73 unsigned long sto: 52;/* Segment-Table Origin */ 74 unsigned long : 1; 75 unsigned long fc : 1; /* Format-Control */ 76 unsigned long p : 1; /* DAT-Protection Bit */ 77 unsigned long : 1; 78 unsigned long tf : 2; /* Segment-Table Offset */ 79 unsigned long i : 1; /* Region-Invalid Bit */ 80 unsigned long cr : 1; /* Common-Region Bit */ 81 unsigned long tt : 2; /* Table-Type Bits */ 82 unsigned long tl : 2; /* Segment-Table Length */ 83 }; 84 85 struct region3_table_entry_fc1 { 86 unsigned long rfaa : 33; /* Region-Frame Absolute Address */ 87 unsigned long : 14; 88 unsigned long av : 1; /* ACCF-Validity Control */ 89 unsigned long acc: 4; /* Access-Control Bits */ 90 unsigned long f : 1; /* Fetch-Protection Bit */ 91 unsigned long fc : 1; /* Format-Control */ 92 unsigned long p : 1; /* DAT-Protection Bit */ 93 unsigned long iep: 1; /* Instruction-Execution-Protection */ 94 unsigned long : 2; 95 unsigned long i : 1; /* Region-Invalid Bit */ 96 unsigned long cr : 1; /* Common-Region Bit */ 97 unsigned long tt : 2; /* Table-Type Bits */ 98 unsigned long : 2; 99 }; 100 101 union region3_table_entry { 102 unsigned long val; 103 struct region3_table_entry_fc0 fc0; 104 struct region3_table_entry_fc1 fc1; 105 struct { 106 unsigned long : 53; 107 unsigned long fc : 1; /* Format-Control */ 108 unsigned long : 4; 109 unsigned long i : 1; /* Region-Invalid Bit */ 110 unsigned long cr : 1; /* Common-Region Bit */ 111 unsigned long tt : 2; /* Table-Type Bits */ 112 unsigned long : 2; 113 }; 114 }; 115 116 struct segment_entry_fc0 { 117 unsigned long pto: 53;/* Page-Table Origin */ 118 unsigned long fc : 1; /* Format-Control */ 119 unsigned long p : 1; /* DAT-Protection Bit */ 120 unsigned long : 3; 121 unsigned long i : 1; /* Segment-Invalid Bit */ 122 unsigned long cs : 1; /* Common-Segment Bit */ 123 unsigned long tt : 2; /* Table-Type Bits */ 124 unsigned long : 2; 125 }; 126 127 struct segment_entry_fc1 { 128 unsigned long sfaa : 44; /* Segment-Frame Absolute Address */ 129 unsigned long : 3; 130 unsigned long av : 1; /* ACCF-Validity Control */ 131 unsigned long acc: 4; /* Access-Control Bits */ 132 unsigned long f : 1; /* Fetch-Protection Bit */ 133 unsigned long fc : 1; /* Format-Control */ 134 unsigned long p : 1; /* DAT-Protection Bit */ 135 unsigned long iep: 1; /* Instruction-Execution-Protection */ 136 unsigned long : 2; 137 unsigned long i : 1; /* Segment-Invalid Bit */ 138 unsigned long cs : 1; /* Common-Segment Bit */ 139 unsigned long tt : 2; /* Table-Type Bits */ 140 unsigned long : 2; 141 }; 142 143 union segment_table_entry { 144 unsigned long val; 145 struct segment_entry_fc0 fc0; 146 struct segment_entry_fc1 fc1; 147 struct { 148 unsigned long : 53; 149 unsigned long fc : 1; /* Format-Control */ 150 unsigned long : 4; 151 unsigned long i : 1; /* Segment-Invalid Bit */ 152 unsigned long cs : 1; /* Common-Segment Bit */ 153 unsigned long tt : 2; /* Table-Type Bits */ 154 unsigned long : 2; 155 }; 156 }; 157 158 enum { 159 TABLE_TYPE_SEGMENT = 0, 160 TABLE_TYPE_REGION3 = 1, 161 TABLE_TYPE_REGION2 = 2, 162 TABLE_TYPE_REGION1 = 3 163 }; 164 165 union page_table_entry { 166 unsigned long val; 167 struct { 168 unsigned long pfra : 52; /* Page-Frame Real Address */ 169 unsigned long z : 1; /* Zero Bit */ 170 unsigned long i : 1; /* Page-Invalid Bit */ 171 unsigned long p : 1; /* DAT-Protection Bit */ 172 unsigned long iep: 1; /* Instruction-Execution-Protection */ 173 unsigned long : 8; 174 }; 175 }; 176 177 /* 178 * vaddress union in order to easily decode a virtual address into its 179 * region first index, region second index etc. parts. 180 */ 181 union vaddress { 182 unsigned long addr; 183 struct { 184 unsigned long rfx : 11; 185 unsigned long rsx : 11; 186 unsigned long rtx : 11; 187 unsigned long sx : 11; 188 unsigned long px : 8; 189 unsigned long bx : 12; 190 }; 191 struct { 192 unsigned long rfx01 : 2; 193 unsigned long : 9; 194 unsigned long rsx01 : 2; 195 unsigned long : 9; 196 unsigned long rtx01 : 2; 197 unsigned long : 9; 198 unsigned long sx01 : 2; 199 unsigned long : 29; 200 }; 201 }; 202 203 /* 204 * raddress union which will contain the result (real or absolute address) 205 * after a page table walk. The rfaa, sfaa and pfra members are used to 206 * simply assign them the value of a region, segment or page table entry. 207 */ 208 union raddress { 209 unsigned long addr; 210 unsigned long rfaa : 33; /* Region-Frame Absolute Address */ 211 unsigned long sfaa : 44; /* Segment-Frame Absolute Address */ 212 unsigned long pfra : 52; /* Page-Frame Real Address */ 213 }; 214 215 union alet { 216 u32 val; 217 struct { 218 u32 reserved : 7; 219 u32 p : 1; 220 u32 alesn : 8; 221 u32 alen : 16; 222 }; 223 }; 224 225 union ald { 226 u32 val; 227 struct { 228 u32 : 1; 229 u32 alo : 24; 230 u32 all : 7; 231 }; 232 }; 233 234 struct ale { 235 unsigned long i : 1; /* ALEN-Invalid Bit */ 236 unsigned long : 5; 237 unsigned long fo : 1; /* Fetch-Only Bit */ 238 unsigned long p : 1; /* Private Bit */ 239 unsigned long alesn : 8; /* Access-List-Entry Sequence Number */ 240 unsigned long aleax : 16; /* Access-List-Entry Authorization Index */ 241 unsigned long : 32; 242 unsigned long : 1; 243 unsigned long asteo : 25; /* ASN-Second-Table-Entry Origin */ 244 unsigned long : 6; 245 unsigned long astesn : 32; /* ASTE Sequence Number */ 246 }; 247 248 struct aste { 249 unsigned long i : 1; /* ASX-Invalid Bit */ 250 unsigned long ato : 29; /* Authority-Table Origin */ 251 unsigned long : 1; 252 unsigned long b : 1; /* Base-Space Bit */ 253 unsigned long ax : 16; /* Authorization Index */ 254 unsigned long atl : 12; /* Authority-Table Length */ 255 unsigned long : 2; 256 unsigned long ca : 1; /* Controlled-ASN Bit */ 257 unsigned long ra : 1; /* Reusable-ASN Bit */ 258 unsigned long asce : 64; /* Address-Space-Control Element */ 259 unsigned long ald : 32; 260 unsigned long astesn : 32; 261 /* .. more fields there */ 262 }; 263 264 int ipte_lock_held(struct kvm_vcpu *vcpu) 265 { 266 if (vcpu->arch.sie_block->eca & ECA_SII) { 267 int rc; 268 269 read_lock(&vcpu->kvm->arch.sca_lock); 270 rc = kvm_s390_get_ipte_control(vcpu->kvm)->kh != 0; 271 read_unlock(&vcpu->kvm->arch.sca_lock); 272 return rc; 273 } 274 return vcpu->kvm->arch.ipte_lock_count != 0; 275 } 276 277 static void ipte_lock_simple(struct kvm_vcpu *vcpu) 278 { 279 union ipte_control old, new, *ic; 280 281 mutex_lock(&vcpu->kvm->arch.ipte_mutex); 282 vcpu->kvm->arch.ipte_lock_count++; 283 if (vcpu->kvm->arch.ipte_lock_count > 1) 284 goto out; 285 retry: 286 read_lock(&vcpu->kvm->arch.sca_lock); 287 ic = kvm_s390_get_ipte_control(vcpu->kvm); 288 do { 289 old = READ_ONCE(*ic); 290 if (old.k) { 291 read_unlock(&vcpu->kvm->arch.sca_lock); 292 cond_resched(); 293 goto retry; 294 } 295 new = old; 296 new.k = 1; 297 } while (cmpxchg(&ic->val, old.val, new.val) != old.val); 298 read_unlock(&vcpu->kvm->arch.sca_lock); 299 out: 300 mutex_unlock(&vcpu->kvm->arch.ipte_mutex); 301 } 302 303 static void ipte_unlock_simple(struct kvm_vcpu *vcpu) 304 { 305 union ipte_control old, new, *ic; 306 307 mutex_lock(&vcpu->kvm->arch.ipte_mutex); 308 vcpu->kvm->arch.ipte_lock_count--; 309 if (vcpu->kvm->arch.ipte_lock_count) 310 goto out; 311 read_lock(&vcpu->kvm->arch.sca_lock); 312 ic = kvm_s390_get_ipte_control(vcpu->kvm); 313 do { 314 old = READ_ONCE(*ic); 315 new = old; 316 new.k = 0; 317 } while (cmpxchg(&ic->val, old.val, new.val) != old.val); 318 read_unlock(&vcpu->kvm->arch.sca_lock); 319 wake_up(&vcpu->kvm->arch.ipte_wq); 320 out: 321 mutex_unlock(&vcpu->kvm->arch.ipte_mutex); 322 } 323 324 static void ipte_lock_siif(struct kvm_vcpu *vcpu) 325 { 326 union ipte_control old, new, *ic; 327 328 retry: 329 read_lock(&vcpu->kvm->arch.sca_lock); 330 ic = kvm_s390_get_ipte_control(vcpu->kvm); 331 do { 332 old = READ_ONCE(*ic); 333 if (old.kg) { 334 read_unlock(&vcpu->kvm->arch.sca_lock); 335 cond_resched(); 336 goto retry; 337 } 338 new = old; 339 new.k = 1; 340 new.kh++; 341 } while (cmpxchg(&ic->val, old.val, new.val) != old.val); 342 read_unlock(&vcpu->kvm->arch.sca_lock); 343 } 344 345 static void ipte_unlock_siif(struct kvm_vcpu *vcpu) 346 { 347 union ipte_control old, new, *ic; 348 349 read_lock(&vcpu->kvm->arch.sca_lock); 350 ic = kvm_s390_get_ipte_control(vcpu->kvm); 351 do { 352 old = READ_ONCE(*ic); 353 new = old; 354 new.kh--; 355 if (!new.kh) 356 new.k = 0; 357 } while (cmpxchg(&ic->val, old.val, new.val) != old.val); 358 read_unlock(&vcpu->kvm->arch.sca_lock); 359 if (!new.kh) 360 wake_up(&vcpu->kvm->arch.ipte_wq); 361 } 362 363 void ipte_lock(struct kvm_vcpu *vcpu) 364 { 365 if (vcpu->arch.sie_block->eca & ECA_SII) 366 ipte_lock_siif(vcpu); 367 else 368 ipte_lock_simple(vcpu); 369 } 370 371 void ipte_unlock(struct kvm_vcpu *vcpu) 372 { 373 if (vcpu->arch.sie_block->eca & ECA_SII) 374 ipte_unlock_siif(vcpu); 375 else 376 ipte_unlock_simple(vcpu); 377 } 378 379 static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce, u8 ar, 380 enum gacc_mode mode) 381 { 382 union alet alet; 383 struct ale ale; 384 struct aste aste; 385 unsigned long ald_addr, authority_table_addr; 386 union ald ald; 387 int eax, rc; 388 u8 authority_table; 389 390 if (ar >= NUM_ACRS) 391 return -EINVAL; 392 393 save_access_regs(vcpu->run->s.regs.acrs); 394 alet.val = vcpu->run->s.regs.acrs[ar]; 395 396 if (ar == 0 || alet.val == 0) { 397 asce->val = vcpu->arch.sie_block->gcr[1]; 398 return 0; 399 } else if (alet.val == 1) { 400 asce->val = vcpu->arch.sie_block->gcr[7]; 401 return 0; 402 } 403 404 if (alet.reserved) 405 return PGM_ALET_SPECIFICATION; 406 407 if (alet.p) 408 ald_addr = vcpu->arch.sie_block->gcr[5]; 409 else 410 ald_addr = vcpu->arch.sie_block->gcr[2]; 411 ald_addr &= 0x7fffffc0; 412 413 rc = read_guest_real(vcpu, ald_addr + 16, &ald.val, sizeof(union ald)); 414 if (rc) 415 return rc; 416 417 if (alet.alen / 8 > ald.all) 418 return PGM_ALEN_TRANSLATION; 419 420 if (0x7fffffff - ald.alo * 128 < alet.alen * 16) 421 return PGM_ADDRESSING; 422 423 rc = read_guest_real(vcpu, ald.alo * 128 + alet.alen * 16, &ale, 424 sizeof(struct ale)); 425 if (rc) 426 return rc; 427 428 if (ale.i == 1) 429 return PGM_ALEN_TRANSLATION; 430 if (ale.alesn != alet.alesn) 431 return PGM_ALE_SEQUENCE; 432 433 rc = read_guest_real(vcpu, ale.asteo * 64, &aste, sizeof(struct aste)); 434 if (rc) 435 return rc; 436 437 if (aste.i) 438 return PGM_ASTE_VALIDITY; 439 if (aste.astesn != ale.astesn) 440 return PGM_ASTE_SEQUENCE; 441 442 if (ale.p == 1) { 443 eax = (vcpu->arch.sie_block->gcr[8] >> 16) & 0xffff; 444 if (ale.aleax != eax) { 445 if (eax / 16 > aste.atl) 446 return PGM_EXTENDED_AUTHORITY; 447 448 authority_table_addr = aste.ato * 4 + eax / 4; 449 450 rc = read_guest_real(vcpu, authority_table_addr, 451 &authority_table, 452 sizeof(u8)); 453 if (rc) 454 return rc; 455 456 if ((authority_table & (0x40 >> ((eax & 3) * 2))) == 0) 457 return PGM_EXTENDED_AUTHORITY; 458 } 459 } 460 461 if (ale.fo == 1 && mode == GACC_STORE) 462 return PGM_PROTECTION; 463 464 asce->val = aste.asce; 465 return 0; 466 } 467 468 struct trans_exc_code_bits { 469 unsigned long addr : 52; /* Translation-exception Address */ 470 unsigned long fsi : 2; /* Access Exception Fetch/Store Indication */ 471 unsigned long : 2; 472 unsigned long b56 : 1; 473 unsigned long : 3; 474 unsigned long b60 : 1; 475 unsigned long b61 : 1; 476 unsigned long as : 2; /* ASCE Identifier */ 477 }; 478 479 enum { 480 FSI_UNKNOWN = 0, /* Unknown wether fetch or store */ 481 FSI_STORE = 1, /* Exception was due to store operation */ 482 FSI_FETCH = 2 /* Exception was due to fetch operation */ 483 }; 484 485 enum prot_type { 486 PROT_TYPE_LA = 0, 487 PROT_TYPE_KEYC = 1, 488 PROT_TYPE_ALC = 2, 489 PROT_TYPE_DAT = 3, 490 PROT_TYPE_IEP = 4, 491 }; 492 493 static int trans_exc(struct kvm_vcpu *vcpu, int code, unsigned long gva, 494 u8 ar, enum gacc_mode mode, enum prot_type prot) 495 { 496 struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm; 497 struct trans_exc_code_bits *tec; 498 499 memset(pgm, 0, sizeof(*pgm)); 500 pgm->code = code; 501 tec = (struct trans_exc_code_bits *)&pgm->trans_exc_code; 502 503 switch (code) { 504 case PGM_PROTECTION: 505 switch (prot) { 506 case PROT_TYPE_IEP: 507 tec->b61 = 1; 508 fallthrough; 509 case PROT_TYPE_LA: 510 tec->b56 = 1; 511 break; 512 case PROT_TYPE_KEYC: 513 tec->b60 = 1; 514 break; 515 case PROT_TYPE_ALC: 516 tec->b60 = 1; 517 fallthrough; 518 case PROT_TYPE_DAT: 519 tec->b61 = 1; 520 break; 521 } 522 fallthrough; 523 case PGM_ASCE_TYPE: 524 case PGM_PAGE_TRANSLATION: 525 case PGM_REGION_FIRST_TRANS: 526 case PGM_REGION_SECOND_TRANS: 527 case PGM_REGION_THIRD_TRANS: 528 case PGM_SEGMENT_TRANSLATION: 529 /* 530 * op_access_id only applies to MOVE_PAGE -> set bit 61 531 * exc_access_id has to be set to 0 for some instructions. Both 532 * cases have to be handled by the caller. 533 */ 534 tec->addr = gva >> PAGE_SHIFT; 535 tec->fsi = mode == GACC_STORE ? FSI_STORE : FSI_FETCH; 536 tec->as = psw_bits(vcpu->arch.sie_block->gpsw).as; 537 fallthrough; 538 case PGM_ALEN_TRANSLATION: 539 case PGM_ALE_SEQUENCE: 540 case PGM_ASTE_VALIDITY: 541 case PGM_ASTE_SEQUENCE: 542 case PGM_EXTENDED_AUTHORITY: 543 /* 544 * We can always store exc_access_id, as it is 545 * undefined for non-ar cases. It is undefined for 546 * most DAT protection exceptions. 547 */ 548 pgm->exc_access_id = ar; 549 break; 550 } 551 return code; 552 } 553 554 static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce, 555 unsigned long ga, u8 ar, enum gacc_mode mode) 556 { 557 int rc; 558 struct psw_bits psw = psw_bits(vcpu->arch.sie_block->gpsw); 559 560 if (!psw.dat) { 561 asce->val = 0; 562 asce->r = 1; 563 return 0; 564 } 565 566 if ((mode == GACC_IFETCH) && (psw.as != PSW_BITS_AS_HOME)) 567 psw.as = PSW_BITS_AS_PRIMARY; 568 569 switch (psw.as) { 570 case PSW_BITS_AS_PRIMARY: 571 asce->val = vcpu->arch.sie_block->gcr[1]; 572 return 0; 573 case PSW_BITS_AS_SECONDARY: 574 asce->val = vcpu->arch.sie_block->gcr[7]; 575 return 0; 576 case PSW_BITS_AS_HOME: 577 asce->val = vcpu->arch.sie_block->gcr[13]; 578 return 0; 579 case PSW_BITS_AS_ACCREG: 580 rc = ar_translation(vcpu, asce, ar, mode); 581 if (rc > 0) 582 return trans_exc(vcpu, rc, ga, ar, mode, PROT_TYPE_ALC); 583 return rc; 584 } 585 return 0; 586 } 587 588 static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val) 589 { 590 return kvm_read_guest(kvm, gpa, val, sizeof(*val)); 591 } 592 593 /** 594 * guest_translate - translate a guest virtual into a guest absolute address 595 * @vcpu: virtual cpu 596 * @gva: guest virtual address 597 * @gpa: points to where guest physical (absolute) address should be stored 598 * @asce: effective asce 599 * @mode: indicates the access mode to be used 600 * @prot: returns the type for protection exceptions 601 * 602 * Translate a guest virtual address into a guest absolute address by means 603 * of dynamic address translation as specified by the architecture. 604 * If the resulting absolute address is not available in the configuration 605 * an addressing exception is indicated and @gpa will not be changed. 606 * 607 * Returns: - zero on success; @gpa contains the resulting absolute address 608 * - a negative value if guest access failed due to e.g. broken 609 * guest mapping 610 * - a positve value if an access exception happened. In this case 611 * the returned value is the program interruption code as defined 612 * by the architecture 613 */ 614 static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, 615 unsigned long *gpa, const union asce asce, 616 enum gacc_mode mode, enum prot_type *prot) 617 { 618 union vaddress vaddr = {.addr = gva}; 619 union raddress raddr = {.addr = gva}; 620 union page_table_entry pte; 621 int dat_protection = 0; 622 int iep_protection = 0; 623 union ctlreg0 ctlreg0; 624 unsigned long ptr; 625 int edat1, edat2, iep; 626 627 ctlreg0.val = vcpu->arch.sie_block->gcr[0]; 628 edat1 = ctlreg0.edat && test_kvm_facility(vcpu->kvm, 8); 629 edat2 = edat1 && test_kvm_facility(vcpu->kvm, 78); 630 iep = ctlreg0.iep && test_kvm_facility(vcpu->kvm, 130); 631 if (asce.r) 632 goto real_address; 633 ptr = asce.origin * PAGE_SIZE; 634 switch (asce.dt) { 635 case ASCE_TYPE_REGION1: 636 if (vaddr.rfx01 > asce.tl) 637 return PGM_REGION_FIRST_TRANS; 638 ptr += vaddr.rfx * 8; 639 break; 640 case ASCE_TYPE_REGION2: 641 if (vaddr.rfx) 642 return PGM_ASCE_TYPE; 643 if (vaddr.rsx01 > asce.tl) 644 return PGM_REGION_SECOND_TRANS; 645 ptr += vaddr.rsx * 8; 646 break; 647 case ASCE_TYPE_REGION3: 648 if (vaddr.rfx || vaddr.rsx) 649 return PGM_ASCE_TYPE; 650 if (vaddr.rtx01 > asce.tl) 651 return PGM_REGION_THIRD_TRANS; 652 ptr += vaddr.rtx * 8; 653 break; 654 case ASCE_TYPE_SEGMENT: 655 if (vaddr.rfx || vaddr.rsx || vaddr.rtx) 656 return PGM_ASCE_TYPE; 657 if (vaddr.sx01 > asce.tl) 658 return PGM_SEGMENT_TRANSLATION; 659 ptr += vaddr.sx * 8; 660 break; 661 } 662 switch (asce.dt) { 663 case ASCE_TYPE_REGION1: { 664 union region1_table_entry rfte; 665 666 if (kvm_is_error_gpa(vcpu->kvm, ptr)) 667 return PGM_ADDRESSING; 668 if (deref_table(vcpu->kvm, ptr, &rfte.val)) 669 return -EFAULT; 670 if (rfte.i) 671 return PGM_REGION_FIRST_TRANS; 672 if (rfte.tt != TABLE_TYPE_REGION1) 673 return PGM_TRANSLATION_SPEC; 674 if (vaddr.rsx01 < rfte.tf || vaddr.rsx01 > rfte.tl) 675 return PGM_REGION_SECOND_TRANS; 676 if (edat1) 677 dat_protection |= rfte.p; 678 ptr = rfte.rto * PAGE_SIZE + vaddr.rsx * 8; 679 } 680 fallthrough; 681 case ASCE_TYPE_REGION2: { 682 union region2_table_entry rste; 683 684 if (kvm_is_error_gpa(vcpu->kvm, ptr)) 685 return PGM_ADDRESSING; 686 if (deref_table(vcpu->kvm, ptr, &rste.val)) 687 return -EFAULT; 688 if (rste.i) 689 return PGM_REGION_SECOND_TRANS; 690 if (rste.tt != TABLE_TYPE_REGION2) 691 return PGM_TRANSLATION_SPEC; 692 if (vaddr.rtx01 < rste.tf || vaddr.rtx01 > rste.tl) 693 return PGM_REGION_THIRD_TRANS; 694 if (edat1) 695 dat_protection |= rste.p; 696 ptr = rste.rto * PAGE_SIZE + vaddr.rtx * 8; 697 } 698 fallthrough; 699 case ASCE_TYPE_REGION3: { 700 union region3_table_entry rtte; 701 702 if (kvm_is_error_gpa(vcpu->kvm, ptr)) 703 return PGM_ADDRESSING; 704 if (deref_table(vcpu->kvm, ptr, &rtte.val)) 705 return -EFAULT; 706 if (rtte.i) 707 return PGM_REGION_THIRD_TRANS; 708 if (rtte.tt != TABLE_TYPE_REGION3) 709 return PGM_TRANSLATION_SPEC; 710 if (rtte.cr && asce.p && edat2) 711 return PGM_TRANSLATION_SPEC; 712 if (rtte.fc && edat2) { 713 dat_protection |= rtte.fc1.p; 714 iep_protection = rtte.fc1.iep; 715 raddr.rfaa = rtte.fc1.rfaa; 716 goto absolute_address; 717 } 718 if (vaddr.sx01 < rtte.fc0.tf) 719 return PGM_SEGMENT_TRANSLATION; 720 if (vaddr.sx01 > rtte.fc0.tl) 721 return PGM_SEGMENT_TRANSLATION; 722 if (edat1) 723 dat_protection |= rtte.fc0.p; 724 ptr = rtte.fc0.sto * PAGE_SIZE + vaddr.sx * 8; 725 } 726 fallthrough; 727 case ASCE_TYPE_SEGMENT: { 728 union segment_table_entry ste; 729 730 if (kvm_is_error_gpa(vcpu->kvm, ptr)) 731 return PGM_ADDRESSING; 732 if (deref_table(vcpu->kvm, ptr, &ste.val)) 733 return -EFAULT; 734 if (ste.i) 735 return PGM_SEGMENT_TRANSLATION; 736 if (ste.tt != TABLE_TYPE_SEGMENT) 737 return PGM_TRANSLATION_SPEC; 738 if (ste.cs && asce.p) 739 return PGM_TRANSLATION_SPEC; 740 if (ste.fc && edat1) { 741 dat_protection |= ste.fc1.p; 742 iep_protection = ste.fc1.iep; 743 raddr.sfaa = ste.fc1.sfaa; 744 goto absolute_address; 745 } 746 dat_protection |= ste.fc0.p; 747 ptr = ste.fc0.pto * (PAGE_SIZE / 2) + vaddr.px * 8; 748 } 749 } 750 if (kvm_is_error_gpa(vcpu->kvm, ptr)) 751 return PGM_ADDRESSING; 752 if (deref_table(vcpu->kvm, ptr, &pte.val)) 753 return -EFAULT; 754 if (pte.i) 755 return PGM_PAGE_TRANSLATION; 756 if (pte.z) 757 return PGM_TRANSLATION_SPEC; 758 dat_protection |= pte.p; 759 iep_protection = pte.iep; 760 raddr.pfra = pte.pfra; 761 real_address: 762 raddr.addr = kvm_s390_real_to_abs(vcpu, raddr.addr); 763 absolute_address: 764 if (mode == GACC_STORE && dat_protection) { 765 *prot = PROT_TYPE_DAT; 766 return PGM_PROTECTION; 767 } 768 if (mode == GACC_IFETCH && iep_protection && iep) { 769 *prot = PROT_TYPE_IEP; 770 return PGM_PROTECTION; 771 } 772 if (kvm_is_error_gpa(vcpu->kvm, raddr.addr)) 773 return PGM_ADDRESSING; 774 *gpa = raddr.addr; 775 return 0; 776 } 777 778 static inline int is_low_address(unsigned long ga) 779 { 780 /* Check for address ranges 0..511 and 4096..4607 */ 781 return (ga & ~0x11fful) == 0; 782 } 783 784 static int low_address_protection_enabled(struct kvm_vcpu *vcpu, 785 const union asce asce) 786 { 787 union ctlreg0 ctlreg0 = {.val = vcpu->arch.sie_block->gcr[0]}; 788 psw_t *psw = &vcpu->arch.sie_block->gpsw; 789 790 if (!ctlreg0.lap) 791 return 0; 792 if (psw_bits(*psw).dat && asce.p) 793 return 0; 794 return 1; 795 } 796 797 static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, 798 unsigned long *pages, unsigned long nr_pages, 799 const union asce asce, enum gacc_mode mode) 800 { 801 psw_t *psw = &vcpu->arch.sie_block->gpsw; 802 int lap_enabled, rc = 0; 803 enum prot_type prot; 804 805 lap_enabled = low_address_protection_enabled(vcpu, asce); 806 while (nr_pages) { 807 ga = kvm_s390_logical_to_effective(vcpu, ga); 808 if (mode == GACC_STORE && lap_enabled && is_low_address(ga)) 809 return trans_exc(vcpu, PGM_PROTECTION, ga, ar, mode, 810 PROT_TYPE_LA); 811 ga &= PAGE_MASK; 812 if (psw_bits(*psw).dat) { 813 rc = guest_translate(vcpu, ga, pages, asce, mode, &prot); 814 if (rc < 0) 815 return rc; 816 } else { 817 *pages = kvm_s390_real_to_abs(vcpu, ga); 818 if (kvm_is_error_gpa(vcpu->kvm, *pages)) 819 rc = PGM_ADDRESSING; 820 } 821 if (rc) 822 return trans_exc(vcpu, rc, ga, ar, mode, prot); 823 ga += PAGE_SIZE; 824 pages++; 825 nr_pages--; 826 } 827 return 0; 828 } 829 830 int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 831 unsigned long len, enum gacc_mode mode) 832 { 833 psw_t *psw = &vcpu->arch.sie_block->gpsw; 834 unsigned long _len, nr_pages, gpa, idx; 835 unsigned long pages_array[2]; 836 unsigned long *pages; 837 int need_ipte_lock; 838 union asce asce; 839 int rc; 840 841 if (!len) 842 return 0; 843 ga = kvm_s390_logical_to_effective(vcpu, ga); 844 rc = get_vcpu_asce(vcpu, &asce, ga, ar, mode); 845 if (rc) 846 return rc; 847 nr_pages = (((ga & ~PAGE_MASK) + len - 1) >> PAGE_SHIFT) + 1; 848 pages = pages_array; 849 if (nr_pages > ARRAY_SIZE(pages_array)) 850 pages = vmalloc(array_size(nr_pages, sizeof(unsigned long))); 851 if (!pages) 852 return -ENOMEM; 853 need_ipte_lock = psw_bits(*psw).dat && !asce.r; 854 if (need_ipte_lock) 855 ipte_lock(vcpu); 856 rc = guest_page_range(vcpu, ga, ar, pages, nr_pages, asce, mode); 857 for (idx = 0; idx < nr_pages && !rc; idx++) { 858 gpa = *(pages + idx) + (ga & ~PAGE_MASK); 859 _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len); 860 if (mode == GACC_STORE) 861 rc = kvm_write_guest(vcpu->kvm, gpa, data, _len); 862 else 863 rc = kvm_read_guest(vcpu->kvm, gpa, data, _len); 864 len -= _len; 865 ga += _len; 866 data += _len; 867 } 868 if (need_ipte_lock) 869 ipte_unlock(vcpu); 870 if (nr_pages > ARRAY_SIZE(pages_array)) 871 vfree(pages); 872 return rc; 873 } 874 875 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, 876 void *data, unsigned long len, enum gacc_mode mode) 877 { 878 unsigned long _len, gpa; 879 int rc = 0; 880 881 while (len && !rc) { 882 gpa = kvm_s390_real_to_abs(vcpu, gra); 883 _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len); 884 if (mode) 885 rc = write_guest_abs(vcpu, gpa, data, _len); 886 else 887 rc = read_guest_abs(vcpu, gpa, data, _len); 888 len -= _len; 889 gra += _len; 890 data += _len; 891 } 892 return rc; 893 } 894 895 /** 896 * guest_translate_address - translate guest logical into guest absolute address 897 * @vcpu: virtual cpu 898 * @gva: Guest virtual address 899 * @ar: Access register 900 * @gpa: Guest physical address 901 * @mode: Translation access mode 902 * 903 * Parameter semantics are the same as the ones from guest_translate. 904 * The memory contents at the guest address are not changed. 905 * 906 * Note: The IPTE lock is not taken during this function, so the caller 907 * has to take care of this. 908 */ 909 int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar, 910 unsigned long *gpa, enum gacc_mode mode) 911 { 912 psw_t *psw = &vcpu->arch.sie_block->gpsw; 913 enum prot_type prot; 914 union asce asce; 915 int rc; 916 917 gva = kvm_s390_logical_to_effective(vcpu, gva); 918 rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode); 919 if (rc) 920 return rc; 921 if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) { 922 if (mode == GACC_STORE) 923 return trans_exc(vcpu, PGM_PROTECTION, gva, 0, 924 mode, PROT_TYPE_LA); 925 } 926 927 if (psw_bits(*psw).dat && !asce.r) { /* Use DAT? */ 928 rc = guest_translate(vcpu, gva, gpa, asce, mode, &prot); 929 if (rc > 0) 930 return trans_exc(vcpu, rc, gva, 0, mode, prot); 931 } else { 932 *gpa = kvm_s390_real_to_abs(vcpu, gva); 933 if (kvm_is_error_gpa(vcpu->kvm, *gpa)) 934 return trans_exc(vcpu, rc, gva, PGM_ADDRESSING, mode, 0); 935 } 936 937 return rc; 938 } 939 940 /** 941 * check_gva_range - test a range of guest virtual addresses for accessibility 942 * @vcpu: virtual cpu 943 * @gva: Guest virtual address 944 * @ar: Access register 945 * @length: Length of test range 946 * @mode: Translation access mode 947 */ 948 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar, 949 unsigned long length, enum gacc_mode mode) 950 { 951 unsigned long gpa; 952 unsigned long currlen; 953 int rc = 0; 954 955 ipte_lock(vcpu); 956 while (length > 0 && !rc) { 957 currlen = min(length, PAGE_SIZE - (gva % PAGE_SIZE)); 958 rc = guest_translate_address(vcpu, gva, ar, &gpa, mode); 959 gva += currlen; 960 length -= currlen; 961 } 962 ipte_unlock(vcpu); 963 964 return rc; 965 } 966 967 /** 968 * kvm_s390_check_low_addr_prot_real - check for low-address protection 969 * @vcpu: virtual cpu 970 * @gra: Guest real address 971 * 972 * Checks whether an address is subject to low-address protection and set 973 * up vcpu->arch.pgm accordingly if necessary. 974 * 975 * Return: 0 if no protection exception, or PGM_PROTECTION if protected. 976 */ 977 int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra) 978 { 979 union ctlreg0 ctlreg0 = {.val = vcpu->arch.sie_block->gcr[0]}; 980 981 if (!ctlreg0.lap || !is_low_address(gra)) 982 return 0; 983 return trans_exc(vcpu, PGM_PROTECTION, gra, 0, GACC_STORE, PROT_TYPE_LA); 984 } 985 986 /** 987 * kvm_s390_shadow_tables - walk the guest page table and create shadow tables 988 * @sg: pointer to the shadow guest address space structure 989 * @saddr: faulting address in the shadow gmap 990 * @pgt: pointer to the beginning of the page table for the given address if 991 * successful (return value 0), or to the first invalid DAT entry in 992 * case of exceptions (return value > 0) 993 * @dat_protection: referenced memory is write protected 994 * @fake: pgt references contiguous guest memory block, not a pgtable 995 */ 996 static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, 997 unsigned long *pgt, int *dat_protection, 998 int *fake) 999 { 1000 struct gmap *parent; 1001 union asce asce; 1002 union vaddress vaddr; 1003 unsigned long ptr; 1004 int rc; 1005 1006 *fake = 0; 1007 *dat_protection = 0; 1008 parent = sg->parent; 1009 vaddr.addr = saddr; 1010 asce.val = sg->orig_asce; 1011 ptr = asce.origin * PAGE_SIZE; 1012 if (asce.r) { 1013 *fake = 1; 1014 ptr = 0; 1015 asce.dt = ASCE_TYPE_REGION1; 1016 } 1017 switch (asce.dt) { 1018 case ASCE_TYPE_REGION1: 1019 if (vaddr.rfx01 > asce.tl && !*fake) 1020 return PGM_REGION_FIRST_TRANS; 1021 break; 1022 case ASCE_TYPE_REGION2: 1023 if (vaddr.rfx) 1024 return PGM_ASCE_TYPE; 1025 if (vaddr.rsx01 > asce.tl) 1026 return PGM_REGION_SECOND_TRANS; 1027 break; 1028 case ASCE_TYPE_REGION3: 1029 if (vaddr.rfx || vaddr.rsx) 1030 return PGM_ASCE_TYPE; 1031 if (vaddr.rtx01 > asce.tl) 1032 return PGM_REGION_THIRD_TRANS; 1033 break; 1034 case ASCE_TYPE_SEGMENT: 1035 if (vaddr.rfx || vaddr.rsx || vaddr.rtx) 1036 return PGM_ASCE_TYPE; 1037 if (vaddr.sx01 > asce.tl) 1038 return PGM_SEGMENT_TRANSLATION; 1039 break; 1040 } 1041 1042 switch (asce.dt) { 1043 case ASCE_TYPE_REGION1: { 1044 union region1_table_entry rfte; 1045 1046 if (*fake) { 1047 ptr += vaddr.rfx * _REGION1_SIZE; 1048 rfte.val = ptr; 1049 goto shadow_r2t; 1050 } 1051 *pgt = ptr + vaddr.rfx * 8; 1052 rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, &rfte.val); 1053 if (rc) 1054 return rc; 1055 if (rfte.i) 1056 return PGM_REGION_FIRST_TRANS; 1057 if (rfte.tt != TABLE_TYPE_REGION1) 1058 return PGM_TRANSLATION_SPEC; 1059 if (vaddr.rsx01 < rfte.tf || vaddr.rsx01 > rfte.tl) 1060 return PGM_REGION_SECOND_TRANS; 1061 if (sg->edat_level >= 1) 1062 *dat_protection |= rfte.p; 1063 ptr = rfte.rto * PAGE_SIZE; 1064 shadow_r2t: 1065 rc = gmap_shadow_r2t(sg, saddr, rfte.val, *fake); 1066 if (rc) 1067 return rc; 1068 } 1069 fallthrough; 1070 case ASCE_TYPE_REGION2: { 1071 union region2_table_entry rste; 1072 1073 if (*fake) { 1074 ptr += vaddr.rsx * _REGION2_SIZE; 1075 rste.val = ptr; 1076 goto shadow_r3t; 1077 } 1078 *pgt = ptr + vaddr.rsx * 8; 1079 rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, &rste.val); 1080 if (rc) 1081 return rc; 1082 if (rste.i) 1083 return PGM_REGION_SECOND_TRANS; 1084 if (rste.tt != TABLE_TYPE_REGION2) 1085 return PGM_TRANSLATION_SPEC; 1086 if (vaddr.rtx01 < rste.tf || vaddr.rtx01 > rste.tl) 1087 return PGM_REGION_THIRD_TRANS; 1088 if (sg->edat_level >= 1) 1089 *dat_protection |= rste.p; 1090 ptr = rste.rto * PAGE_SIZE; 1091 shadow_r3t: 1092 rste.p |= *dat_protection; 1093 rc = gmap_shadow_r3t(sg, saddr, rste.val, *fake); 1094 if (rc) 1095 return rc; 1096 } 1097 fallthrough; 1098 case ASCE_TYPE_REGION3: { 1099 union region3_table_entry rtte; 1100 1101 if (*fake) { 1102 ptr += vaddr.rtx * _REGION3_SIZE; 1103 rtte.val = ptr; 1104 goto shadow_sgt; 1105 } 1106 *pgt = ptr + vaddr.rtx * 8; 1107 rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, &rtte.val); 1108 if (rc) 1109 return rc; 1110 if (rtte.i) 1111 return PGM_REGION_THIRD_TRANS; 1112 if (rtte.tt != TABLE_TYPE_REGION3) 1113 return PGM_TRANSLATION_SPEC; 1114 if (rtte.cr && asce.p && sg->edat_level >= 2) 1115 return PGM_TRANSLATION_SPEC; 1116 if (rtte.fc && sg->edat_level >= 2) { 1117 *dat_protection |= rtte.fc0.p; 1118 *fake = 1; 1119 ptr = rtte.fc1.rfaa * _REGION3_SIZE; 1120 rtte.val = ptr; 1121 goto shadow_sgt; 1122 } 1123 if (vaddr.sx01 < rtte.fc0.tf || vaddr.sx01 > rtte.fc0.tl) 1124 return PGM_SEGMENT_TRANSLATION; 1125 if (sg->edat_level >= 1) 1126 *dat_protection |= rtte.fc0.p; 1127 ptr = rtte.fc0.sto * PAGE_SIZE; 1128 shadow_sgt: 1129 rtte.fc0.p |= *dat_protection; 1130 rc = gmap_shadow_sgt(sg, saddr, rtte.val, *fake); 1131 if (rc) 1132 return rc; 1133 } 1134 fallthrough; 1135 case ASCE_TYPE_SEGMENT: { 1136 union segment_table_entry ste; 1137 1138 if (*fake) { 1139 ptr += vaddr.sx * _SEGMENT_SIZE; 1140 ste.val = ptr; 1141 goto shadow_pgt; 1142 } 1143 *pgt = ptr + vaddr.sx * 8; 1144 rc = gmap_read_table(parent, ptr + vaddr.sx * 8, &ste.val); 1145 if (rc) 1146 return rc; 1147 if (ste.i) 1148 return PGM_SEGMENT_TRANSLATION; 1149 if (ste.tt != TABLE_TYPE_SEGMENT) 1150 return PGM_TRANSLATION_SPEC; 1151 if (ste.cs && asce.p) 1152 return PGM_TRANSLATION_SPEC; 1153 *dat_protection |= ste.fc0.p; 1154 if (ste.fc && sg->edat_level >= 1) { 1155 *fake = 1; 1156 ptr = ste.fc1.sfaa * _SEGMENT_SIZE; 1157 ste.val = ptr; 1158 goto shadow_pgt; 1159 } 1160 ptr = ste.fc0.pto * (PAGE_SIZE / 2); 1161 shadow_pgt: 1162 ste.fc0.p |= *dat_protection; 1163 rc = gmap_shadow_pgt(sg, saddr, ste.val, *fake); 1164 if (rc) 1165 return rc; 1166 } 1167 } 1168 /* Return the parent address of the page table */ 1169 *pgt = ptr; 1170 return 0; 1171 } 1172 1173 /** 1174 * kvm_s390_shadow_fault - handle fault on a shadow page table 1175 * @vcpu: virtual cpu 1176 * @sg: pointer to the shadow guest address space structure 1177 * @saddr: faulting address in the shadow gmap 1178 * @datptr: will contain the address of the faulting DAT table entry, or of 1179 * the valid leaf, plus some flags 1180 * 1181 * Returns: - 0 if the shadow fault was successfully resolved 1182 * - > 0 (pgm exception code) on exceptions while faulting 1183 * - -EAGAIN if the caller can retry immediately 1184 * - -EFAULT when accessing invalid guest addresses 1185 * - -ENOMEM if out of memory 1186 */ 1187 int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg, 1188 unsigned long saddr, unsigned long *datptr) 1189 { 1190 union vaddress vaddr; 1191 union page_table_entry pte; 1192 unsigned long pgt = 0; 1193 int dat_protection, fake; 1194 int rc; 1195 1196 mmap_read_lock(sg->mm); 1197 /* 1198 * We don't want any guest-2 tables to change - so the parent 1199 * tables/pointers we read stay valid - unshadowing is however 1200 * always possible - only guest_table_lock protects us. 1201 */ 1202 ipte_lock(vcpu); 1203 1204 rc = gmap_shadow_pgt_lookup(sg, saddr, &pgt, &dat_protection, &fake); 1205 if (rc) 1206 rc = kvm_s390_shadow_tables(sg, saddr, &pgt, &dat_protection, 1207 &fake); 1208 1209 vaddr.addr = saddr; 1210 if (fake) { 1211 pte.val = pgt + vaddr.px * PAGE_SIZE; 1212 goto shadow_page; 1213 } 1214 1215 switch (rc) { 1216 case PGM_SEGMENT_TRANSLATION: 1217 case PGM_REGION_THIRD_TRANS: 1218 case PGM_REGION_SECOND_TRANS: 1219 case PGM_REGION_FIRST_TRANS: 1220 pgt |= PEI_NOT_PTE; 1221 break; 1222 case 0: 1223 pgt += vaddr.px * 8; 1224 rc = gmap_read_table(sg->parent, pgt, &pte.val); 1225 } 1226 if (datptr) 1227 *datptr = pgt | dat_protection * PEI_DAT_PROT; 1228 if (!rc && pte.i) 1229 rc = PGM_PAGE_TRANSLATION; 1230 if (!rc && pte.z) 1231 rc = PGM_TRANSLATION_SPEC; 1232 shadow_page: 1233 pte.p |= dat_protection; 1234 if (!rc) 1235 rc = gmap_shadow_page(sg, saddr, __pte(pte.val)); 1236 ipte_unlock(vcpu); 1237 mmap_read_unlock(sg->mm); 1238 return rc; 1239 } 1240