1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2017 - Columbia University and Linaro Ltd. 4 * Author: Jintack Lim <jintack.lim@linaro.org> 5 */ 6 7 #include <linux/bitfield.h> 8 #include <linux/kvm.h> 9 #include <linux/kvm_host.h> 10 11 #include <asm/fixmap.h> 12 #include <asm/kvm_arm.h> 13 #include <asm/kvm_emulate.h> 14 #include <asm/kvm_mmu.h> 15 #include <asm/kvm_nested.h> 16 #include <asm/sysreg.h> 17 18 #include "sys_regs.h" 19 20 struct vncr_tlb { 21 /* The guest's VNCR_EL2 */ 22 u64 gva; 23 struct s1_walk_info wi; 24 struct s1_walk_result wr; 25 26 u64 hpa; 27 28 /* -1 when not mapped on a CPU */ 29 int cpu; 30 31 /* 32 * true if the TLB is valid. Can only be changed with the 33 * mmu_lock held. 34 */ 35 bool valid; 36 }; 37 38 /* 39 * Ratio of live shadow S2 MMU per vcpu. This is a trade-off between 40 * memory usage and potential number of different sets of S2 PTs in 41 * the guests. Running out of S2 MMUs only affects performance (we 42 * will invalidate them more often). 43 */ 44 #define S2_MMU_PER_VCPU 2 45 46 void kvm_init_nested(struct kvm *kvm) 47 { 48 kvm->arch.nested_mmus = NULL; 49 kvm->arch.nested_mmus_size = 0; 50 atomic_set(&kvm->arch.vncr_map_count, 0); 51 } 52 53 static int init_nested_s2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu) 54 { 55 /* 56 * We only initialise the IPA range on the canonical MMU, which 57 * defines the contract between KVM and userspace on where the 58 * "hardware" is in the IPA space. This affects the validity of MMIO 59 * exits forwarded to userspace, for example. 60 * 61 * For nested S2s, we use the PARange as exposed to the guest, as it 62 * is allowed to use it at will to expose whatever memory map it 63 * wants to its own guests as it would be on real HW. 64 */ 65 return kvm_init_stage2_mmu(kvm, mmu, kvm_get_pa_bits(kvm)); 66 } 67 68 int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu) 69 { 70 struct kvm *kvm = vcpu->kvm; 71 struct kvm_s2_mmu *tmp; 72 int num_mmus, ret = 0; 73 74 if (test_bit(KVM_ARM_VCPU_HAS_EL2_E2H0, kvm->arch.vcpu_features) && 75 !cpus_have_final_cap(ARM64_HAS_HCR_NV1)) 76 return -EINVAL; 77 78 if (!vcpu->arch.ctxt.vncr_array) 79 vcpu->arch.ctxt.vncr_array = (u64 *)__get_free_page(GFP_KERNEL_ACCOUNT | 80 __GFP_ZERO); 81 82 if (!vcpu->arch.ctxt.vncr_array) 83 return -ENOMEM; 84 85 /* 86 * Let's treat memory allocation failures as benign: If we fail to 87 * allocate anything, return an error and keep the allocated array 88 * alive. Userspace may try to recover by intializing the vcpu 89 * again, and there is no reason to affect the whole VM for this. 90 */ 91 num_mmus = atomic_read(&kvm->online_vcpus) * S2_MMU_PER_VCPU; 92 tmp = kvrealloc(kvm->arch.nested_mmus, 93 size_mul(sizeof(*kvm->arch.nested_mmus), num_mmus), 94 GFP_KERNEL_ACCOUNT | __GFP_ZERO); 95 if (!tmp) 96 return -ENOMEM; 97 98 swap(kvm->arch.nested_mmus, tmp); 99 100 /* 101 * If we went through a realocation, adjust the MMU back-pointers in 102 * the previously initialised kvm_pgtable structures. 103 */ 104 if (kvm->arch.nested_mmus != tmp) 105 for (int i = 0; i < kvm->arch.nested_mmus_size; i++) 106 kvm->arch.nested_mmus[i].pgt->mmu = &kvm->arch.nested_mmus[i]; 107 108 for (int i = kvm->arch.nested_mmus_size; !ret && i < num_mmus; i++) 109 ret = init_nested_s2_mmu(kvm, &kvm->arch.nested_mmus[i]); 110 111 if (ret) { 112 for (int i = kvm->arch.nested_mmus_size; i < num_mmus; i++) 113 kvm_free_stage2_pgd(&kvm->arch.nested_mmus[i]); 114 115 free_page((unsigned long)vcpu->arch.ctxt.vncr_array); 116 vcpu->arch.ctxt.vncr_array = NULL; 117 118 return ret; 119 } 120 121 kvm->arch.nested_mmus_size = num_mmus; 122 123 return 0; 124 } 125 126 struct s2_walk_info { 127 int (*read_desc)(phys_addr_t pa, u64 *desc, void *data); 128 void *data; 129 u64 baddr; 130 unsigned int max_oa_bits; 131 unsigned int pgshift; 132 unsigned int sl; 133 unsigned int t0sz; 134 bool be; 135 }; 136 137 static u32 compute_fsc(int level, u32 fsc) 138 { 139 return fsc | (level & 0x3); 140 } 141 142 static int esr_s2_fault(struct kvm_vcpu *vcpu, int level, u32 fsc) 143 { 144 u32 esr; 145 146 esr = kvm_vcpu_get_esr(vcpu) & ~ESR_ELx_FSC; 147 esr |= compute_fsc(level, fsc); 148 return esr; 149 } 150 151 static int get_ia_size(struct s2_walk_info *wi) 152 { 153 return 64 - wi->t0sz; 154 } 155 156 static int check_base_s2_limits(struct s2_walk_info *wi, 157 int level, int input_size, int stride) 158 { 159 int start_size, ia_size; 160 161 ia_size = get_ia_size(wi); 162 163 /* Check translation limits */ 164 switch (BIT(wi->pgshift)) { 165 case SZ_64K: 166 if (level == 0 || (level == 1 && ia_size <= 42)) 167 return -EFAULT; 168 break; 169 case SZ_16K: 170 if (level == 0 || (level == 1 && ia_size <= 40)) 171 return -EFAULT; 172 break; 173 case SZ_4K: 174 if (level < 0 || (level == 0 && ia_size <= 42)) 175 return -EFAULT; 176 break; 177 } 178 179 /* Check input size limits */ 180 if (input_size > ia_size) 181 return -EFAULT; 182 183 /* Check number of entries in starting level table */ 184 start_size = input_size - ((3 - level) * stride + wi->pgshift); 185 if (start_size < 1 || start_size > stride + 4) 186 return -EFAULT; 187 188 return 0; 189 } 190 191 /* Check if output is within boundaries */ 192 static int check_output_size(struct s2_walk_info *wi, phys_addr_t output) 193 { 194 unsigned int output_size = wi->max_oa_bits; 195 196 if (output_size != 48 && (output & GENMASK_ULL(47, output_size))) 197 return -1; 198 199 return 0; 200 } 201 202 /* 203 * This is essentially a C-version of the pseudo code from the ARM ARM 204 * AArch64.TranslationTableWalk function. I strongly recommend looking at 205 * that pseudocode in trying to understand this. 206 * 207 * Must be called with the kvm->srcu read lock held 208 */ 209 static int walk_nested_s2_pgd(phys_addr_t ipa, 210 struct s2_walk_info *wi, struct kvm_s2_trans *out) 211 { 212 int first_block_level, level, stride, input_size, base_lower_bound; 213 phys_addr_t base_addr; 214 unsigned int addr_top, addr_bottom; 215 u64 desc; /* page table entry */ 216 int ret; 217 phys_addr_t paddr; 218 219 switch (BIT(wi->pgshift)) { 220 default: 221 case SZ_64K: 222 case SZ_16K: 223 level = 3 - wi->sl; 224 first_block_level = 2; 225 break; 226 case SZ_4K: 227 level = 2 - wi->sl; 228 first_block_level = 1; 229 break; 230 } 231 232 stride = wi->pgshift - 3; 233 input_size = get_ia_size(wi); 234 if (input_size > 48 || input_size < 25) 235 return -EFAULT; 236 237 ret = check_base_s2_limits(wi, level, input_size, stride); 238 if (WARN_ON(ret)) 239 return ret; 240 241 base_lower_bound = 3 + input_size - ((3 - level) * stride + 242 wi->pgshift); 243 base_addr = wi->baddr & GENMASK_ULL(47, base_lower_bound); 244 245 if (check_output_size(wi, base_addr)) { 246 out->esr = compute_fsc(level, ESR_ELx_FSC_ADDRSZ); 247 return 1; 248 } 249 250 addr_top = input_size - 1; 251 252 while (1) { 253 phys_addr_t index; 254 255 addr_bottom = (3 - level) * stride + wi->pgshift; 256 index = (ipa & GENMASK_ULL(addr_top, addr_bottom)) 257 >> (addr_bottom - 3); 258 259 paddr = base_addr | index; 260 ret = wi->read_desc(paddr, &desc, wi->data); 261 if (ret < 0) 262 return ret; 263 264 /* 265 * Handle reversedescriptors if endianness differs between the 266 * host and the guest hypervisor. 267 */ 268 if (wi->be) 269 desc = be64_to_cpu((__force __be64)desc); 270 else 271 desc = le64_to_cpu((__force __le64)desc); 272 273 /* Check for valid descriptor at this point */ 274 if (!(desc & 1) || ((desc & 3) == 1 && level == 3)) { 275 out->esr = compute_fsc(level, ESR_ELx_FSC_FAULT); 276 out->desc = desc; 277 return 1; 278 } 279 280 /* We're at the final level or block translation level */ 281 if ((desc & 3) == 1 || level == 3) 282 break; 283 284 if (check_output_size(wi, desc)) { 285 out->esr = compute_fsc(level, ESR_ELx_FSC_ADDRSZ); 286 out->desc = desc; 287 return 1; 288 } 289 290 base_addr = desc & GENMASK_ULL(47, wi->pgshift); 291 292 level += 1; 293 addr_top = addr_bottom - 1; 294 } 295 296 if (level < first_block_level) { 297 out->esr = compute_fsc(level, ESR_ELx_FSC_FAULT); 298 out->desc = desc; 299 return 1; 300 } 301 302 if (check_output_size(wi, desc)) { 303 out->esr = compute_fsc(level, ESR_ELx_FSC_ADDRSZ); 304 out->desc = desc; 305 return 1; 306 } 307 308 if (!(desc & BIT(10))) { 309 out->esr = compute_fsc(level, ESR_ELx_FSC_ACCESS); 310 out->desc = desc; 311 return 1; 312 } 313 314 addr_bottom += contiguous_bit_shift(desc, wi, level); 315 316 /* Calculate and return the result */ 317 paddr = (desc & GENMASK_ULL(47, addr_bottom)) | 318 (ipa & GENMASK_ULL(addr_bottom - 1, 0)); 319 out->output = paddr; 320 out->block_size = 1UL << ((3 - level) * stride + wi->pgshift); 321 out->readable = desc & (0b01 << 6); 322 out->writable = desc & (0b10 << 6); 323 out->level = level; 324 out->desc = desc; 325 return 0; 326 } 327 328 static int read_guest_s2_desc(phys_addr_t pa, u64 *desc, void *data) 329 { 330 struct kvm_vcpu *vcpu = data; 331 332 return kvm_read_guest(vcpu->kvm, pa, desc, sizeof(*desc)); 333 } 334 335 static void vtcr_to_walk_info(u64 vtcr, struct s2_walk_info *wi) 336 { 337 wi->t0sz = vtcr & TCR_EL2_T0SZ_MASK; 338 339 switch (vtcr & VTCR_EL2_TG0_MASK) { 340 case VTCR_EL2_TG0_4K: 341 wi->pgshift = 12; break; 342 case VTCR_EL2_TG0_16K: 343 wi->pgshift = 14; break; 344 case VTCR_EL2_TG0_64K: 345 default: /* IMPDEF: treat any other value as 64k */ 346 wi->pgshift = 16; break; 347 } 348 349 wi->sl = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); 350 /* Global limit for now, should eventually be per-VM */ 351 wi->max_oa_bits = min(get_kvm_ipa_limit(), 352 ps_to_output_size(FIELD_GET(VTCR_EL2_PS_MASK, vtcr))); 353 } 354 355 int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa, 356 struct kvm_s2_trans *result) 357 { 358 u64 vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2); 359 struct s2_walk_info wi; 360 int ret; 361 362 result->esr = 0; 363 364 if (!vcpu_has_nv(vcpu)) 365 return 0; 366 367 wi.read_desc = read_guest_s2_desc; 368 wi.data = vcpu; 369 wi.baddr = vcpu_read_sys_reg(vcpu, VTTBR_EL2); 370 371 vtcr_to_walk_info(vtcr, &wi); 372 373 wi.be = vcpu_read_sys_reg(vcpu, SCTLR_EL2) & SCTLR_ELx_EE; 374 375 ret = walk_nested_s2_pgd(gipa, &wi, result); 376 if (ret) 377 result->esr |= (kvm_vcpu_get_esr(vcpu) & ~ESR_ELx_FSC); 378 379 return ret; 380 } 381 382 static unsigned int ttl_to_size(u8 ttl) 383 { 384 int level = ttl & 3; 385 int gran = (ttl >> 2) & 3; 386 unsigned int max_size = 0; 387 388 switch (gran) { 389 case TLBI_TTL_TG_4K: 390 switch (level) { 391 case 0: 392 break; 393 case 1: 394 max_size = SZ_1G; 395 break; 396 case 2: 397 max_size = SZ_2M; 398 break; 399 case 3: 400 max_size = SZ_4K; 401 break; 402 } 403 break; 404 case TLBI_TTL_TG_16K: 405 switch (level) { 406 case 0: 407 case 1: 408 break; 409 case 2: 410 max_size = SZ_32M; 411 break; 412 case 3: 413 max_size = SZ_16K; 414 break; 415 } 416 break; 417 case TLBI_TTL_TG_64K: 418 switch (level) { 419 case 0: 420 case 1: 421 /* No 52bit IPA support */ 422 break; 423 case 2: 424 max_size = SZ_512M; 425 break; 426 case 3: 427 max_size = SZ_64K; 428 break; 429 } 430 break; 431 default: /* No size information */ 432 break; 433 } 434 435 return max_size; 436 } 437 438 static u8 pgshift_level_to_ttl(u16 shift, u8 level) 439 { 440 u8 ttl; 441 442 switch(shift) { 443 case 12: 444 ttl = TLBI_TTL_TG_4K; 445 break; 446 case 14: 447 ttl = TLBI_TTL_TG_16K; 448 break; 449 case 16: 450 ttl = TLBI_TTL_TG_64K; 451 break; 452 default: 453 BUG(); 454 } 455 456 ttl <<= 2; 457 ttl |= level & 3; 458 459 return ttl; 460 } 461 462 /* 463 * Compute the equivalent of the TTL field by parsing the shadow PT. The 464 * granule size is extracted from the cached VTCR_EL2.TG0 while the level is 465 * retrieved from first entry carrying the level as a tag. 466 */ 467 static u8 get_guest_mapping_ttl(struct kvm_s2_mmu *mmu, u64 addr) 468 { 469 u64 tmp, sz = 0, vtcr = mmu->tlb_vtcr; 470 kvm_pte_t pte; 471 u8 ttl, level; 472 473 lockdep_assert_held_write(&kvm_s2_mmu_to_kvm(mmu)->mmu_lock); 474 475 switch (vtcr & VTCR_EL2_TG0_MASK) { 476 case VTCR_EL2_TG0_4K: 477 ttl = (TLBI_TTL_TG_4K << 2); 478 break; 479 case VTCR_EL2_TG0_16K: 480 ttl = (TLBI_TTL_TG_16K << 2); 481 break; 482 case VTCR_EL2_TG0_64K: 483 default: /* IMPDEF: treat any other value as 64k */ 484 ttl = (TLBI_TTL_TG_64K << 2); 485 break; 486 } 487 488 tmp = addr; 489 490 again: 491 /* Iteratively compute the block sizes for a particular granule size */ 492 switch (vtcr & VTCR_EL2_TG0_MASK) { 493 case VTCR_EL2_TG0_4K: 494 if (sz < SZ_4K) sz = SZ_4K; 495 else if (sz < SZ_2M) sz = SZ_2M; 496 else if (sz < SZ_1G) sz = SZ_1G; 497 else sz = 0; 498 break; 499 case VTCR_EL2_TG0_16K: 500 if (sz < SZ_16K) sz = SZ_16K; 501 else if (sz < SZ_32M) sz = SZ_32M; 502 else sz = 0; 503 break; 504 case VTCR_EL2_TG0_64K: 505 default: /* IMPDEF: treat any other value as 64k */ 506 if (sz < SZ_64K) sz = SZ_64K; 507 else if (sz < SZ_512M) sz = SZ_512M; 508 else sz = 0; 509 break; 510 } 511 512 if (sz == 0) 513 return 0; 514 515 tmp &= ~(sz - 1); 516 if (kvm_pgtable_get_leaf(mmu->pgt, tmp, &pte, NULL)) 517 goto again; 518 if (!(pte & PTE_VALID)) 519 goto again; 520 level = FIELD_GET(KVM_NV_GUEST_MAP_SZ, pte); 521 if (!level) 522 goto again; 523 524 ttl |= level; 525 526 /* 527 * We now have found some level information in the shadow S2. Check 528 * that the resulting range is actually including the original IPA. 529 */ 530 sz = ttl_to_size(ttl); 531 if (addr < (tmp + sz)) 532 return ttl; 533 534 return 0; 535 } 536 537 unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val) 538 { 539 struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); 540 unsigned long max_size; 541 u8 ttl; 542 543 ttl = FIELD_GET(TLBI_TTL_MASK, val); 544 545 if (!ttl || !kvm_has_feat(kvm, ID_AA64MMFR2_EL1, TTL, IMP)) { 546 /* No TTL, check the shadow S2 for a hint */ 547 u64 addr = (val & GENMASK_ULL(35, 0)) << 12; 548 ttl = get_guest_mapping_ttl(mmu, addr); 549 } 550 551 max_size = ttl_to_size(ttl); 552 553 if (!max_size) { 554 /* Compute the maximum extent of the invalidation */ 555 switch (mmu->tlb_vtcr & VTCR_EL2_TG0_MASK) { 556 case VTCR_EL2_TG0_4K: 557 max_size = SZ_1G; 558 break; 559 case VTCR_EL2_TG0_16K: 560 max_size = SZ_32M; 561 break; 562 case VTCR_EL2_TG0_64K: 563 default: /* IMPDEF: treat any other value as 64k */ 564 /* 565 * No, we do not support 52bit IPA in nested yet. Once 566 * we do, this should be 4TB. 567 */ 568 max_size = SZ_512M; 569 break; 570 } 571 } 572 573 WARN_ON(!max_size); 574 return max_size; 575 } 576 577 /* 578 * We can have multiple *different* MMU contexts with the same VMID: 579 * 580 * - S2 being enabled or not, hence differing by the HCR_EL2.VM bit 581 * 582 * - Multiple vcpus using private S2s (huh huh...), hence differing by the 583 * VBBTR_EL2.BADDR address 584 * 585 * - A combination of the above... 586 * 587 * We can always identify which MMU context to pick at run-time. However, 588 * TLB invalidation involving a VMID must take action on all the TLBs using 589 * this particular VMID. This translates into applying the same invalidation 590 * operation to all the contexts that are using this VMID. Moar phun! 591 */ 592 void kvm_s2_mmu_iterate_by_vmid(struct kvm *kvm, u16 vmid, 593 const union tlbi_info *info, 594 void (*tlbi_callback)(struct kvm_s2_mmu *, 595 const union tlbi_info *)) 596 { 597 write_lock(&kvm->mmu_lock); 598 599 for (int i = 0; i < kvm->arch.nested_mmus_size; i++) { 600 struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; 601 602 if (!kvm_s2_mmu_valid(mmu)) 603 continue; 604 605 if (vmid == get_vmid(mmu->tlb_vttbr)) 606 tlbi_callback(mmu, info); 607 } 608 609 write_unlock(&kvm->mmu_lock); 610 } 611 612 struct kvm_s2_mmu *lookup_s2_mmu(struct kvm_vcpu *vcpu) 613 { 614 struct kvm *kvm = vcpu->kvm; 615 bool nested_stage2_enabled; 616 u64 vttbr, vtcr, hcr; 617 618 lockdep_assert_held_write(&kvm->mmu_lock); 619 620 vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2); 621 vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2); 622 hcr = vcpu_read_sys_reg(vcpu, HCR_EL2); 623 624 nested_stage2_enabled = hcr & HCR_VM; 625 626 /* Don't consider the CnP bit for the vttbr match */ 627 vttbr &= ~VTTBR_CNP_BIT; 628 629 /* 630 * Two possibilities when looking up a S2 MMU context: 631 * 632 * - either S2 is enabled in the guest, and we need a context that is 633 * S2-enabled and matches the full VTTBR (VMID+BADDR) and VTCR, 634 * which makes it safe from a TLB conflict perspective (a broken 635 * guest won't be able to generate them), 636 * 637 * - or S2 is disabled, and we need a context that is S2-disabled 638 * and matches the VMID only, as all TLBs are tagged by VMID even 639 * if S2 translation is disabled. 640 */ 641 for (int i = 0; i < kvm->arch.nested_mmus_size; i++) { 642 struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; 643 644 if (!kvm_s2_mmu_valid(mmu)) 645 continue; 646 647 if (nested_stage2_enabled && 648 mmu->nested_stage2_enabled && 649 vttbr == mmu->tlb_vttbr && 650 vtcr == mmu->tlb_vtcr) 651 return mmu; 652 653 if (!nested_stage2_enabled && 654 !mmu->nested_stage2_enabled && 655 get_vmid(vttbr) == get_vmid(mmu->tlb_vttbr)) 656 return mmu; 657 } 658 return NULL; 659 } 660 661 static struct kvm_s2_mmu *get_s2_mmu_nested(struct kvm_vcpu *vcpu) 662 { 663 struct kvm *kvm = vcpu->kvm; 664 struct kvm_s2_mmu *s2_mmu; 665 int i; 666 667 lockdep_assert_held_write(&vcpu->kvm->mmu_lock); 668 669 s2_mmu = lookup_s2_mmu(vcpu); 670 if (s2_mmu) 671 goto out; 672 673 /* 674 * Make sure we don't always search from the same point, or we 675 * will always reuse a potentially active context, leaving 676 * free contexts unused. 677 */ 678 for (i = kvm->arch.nested_mmus_next; 679 i < (kvm->arch.nested_mmus_size + kvm->arch.nested_mmus_next); 680 i++) { 681 s2_mmu = &kvm->arch.nested_mmus[i % kvm->arch.nested_mmus_size]; 682 683 if (atomic_read(&s2_mmu->refcnt) == 0) 684 break; 685 } 686 BUG_ON(atomic_read(&s2_mmu->refcnt)); /* We have struct MMUs to spare */ 687 688 /* Set the scene for the next search */ 689 kvm->arch.nested_mmus_next = (i + 1) % kvm->arch.nested_mmus_size; 690 691 /* Make sure we don't forget to do the laundry */ 692 if (kvm_s2_mmu_valid(s2_mmu)) 693 s2_mmu->pending_unmap = true; 694 695 /* 696 * The virtual VMID (modulo CnP) will be used as a key when matching 697 * an existing kvm_s2_mmu. 698 * 699 * We cache VTCR at allocation time, once and for all. It'd be great 700 * if the guest didn't screw that one up, as this is not very 701 * forgiving... 702 */ 703 s2_mmu->tlb_vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2) & ~VTTBR_CNP_BIT; 704 s2_mmu->tlb_vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2); 705 s2_mmu->nested_stage2_enabled = vcpu_read_sys_reg(vcpu, HCR_EL2) & HCR_VM; 706 707 out: 708 atomic_inc(&s2_mmu->refcnt); 709 710 /* 711 * Set the vCPU request to perform an unmap, even if the pending unmap 712 * originates from another vCPU. This guarantees that the MMU has been 713 * completely unmapped before any vCPU actually uses it, and allows 714 * multiple vCPUs to lend a hand with completing the unmap. 715 */ 716 if (s2_mmu->pending_unmap) 717 kvm_make_request(KVM_REQ_NESTED_S2_UNMAP, vcpu); 718 719 return s2_mmu; 720 } 721 722 void kvm_init_nested_s2_mmu(struct kvm_s2_mmu *mmu) 723 { 724 /* CnP being set denotes an invalid entry */ 725 mmu->tlb_vttbr = VTTBR_CNP_BIT; 726 mmu->nested_stage2_enabled = false; 727 atomic_set(&mmu->refcnt, 0); 728 } 729 730 void kvm_vcpu_load_hw_mmu(struct kvm_vcpu *vcpu) 731 { 732 /* 733 * If the vCPU kept its reference on the MMU after the last put, 734 * keep rolling with it. 735 */ 736 if (is_hyp_ctxt(vcpu)) { 737 if (!vcpu->arch.hw_mmu) 738 vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu; 739 } else { 740 if (!vcpu->arch.hw_mmu) { 741 scoped_guard(write_lock, &vcpu->kvm->mmu_lock) 742 vcpu->arch.hw_mmu = get_s2_mmu_nested(vcpu); 743 } 744 745 if (__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_NV) 746 kvm_make_request(KVM_REQ_MAP_L1_VNCR_EL2, vcpu); 747 } 748 } 749 750 void kvm_vcpu_put_hw_mmu(struct kvm_vcpu *vcpu) 751 { 752 /* Unconditionally drop the VNCR mapping if we have one */ 753 if (host_data_test_flag(L1_VNCR_MAPPED)) { 754 BUG_ON(vcpu->arch.vncr_tlb->cpu != smp_processor_id()); 755 BUG_ON(is_hyp_ctxt(vcpu)); 756 757 clear_fixmap(vncr_fixmap(vcpu->arch.vncr_tlb->cpu)); 758 vcpu->arch.vncr_tlb->cpu = -1; 759 host_data_clear_flag(L1_VNCR_MAPPED); 760 atomic_dec(&vcpu->kvm->arch.vncr_map_count); 761 } 762 763 /* 764 * Keep a reference on the associated stage-2 MMU if the vCPU is 765 * scheduling out and not in WFI emulation, suggesting it is likely to 766 * reuse the MMU sometime soon. 767 */ 768 if (vcpu->scheduled_out && !vcpu_get_flag(vcpu, IN_WFI)) 769 return; 770 771 if (kvm_is_nested_s2_mmu(vcpu->kvm, vcpu->arch.hw_mmu)) 772 atomic_dec(&vcpu->arch.hw_mmu->refcnt); 773 774 vcpu->arch.hw_mmu = NULL; 775 } 776 777 /* 778 * Returns non-zero if permission fault is handled by injecting it to the next 779 * level hypervisor. 780 */ 781 int kvm_s2_handle_perm_fault(struct kvm_vcpu *vcpu, struct kvm_s2_trans *trans) 782 { 783 bool forward_fault = false; 784 785 trans->esr = 0; 786 787 if (!kvm_vcpu_trap_is_permission_fault(vcpu)) 788 return 0; 789 790 if (kvm_vcpu_trap_is_iabt(vcpu)) { 791 forward_fault = !kvm_s2_trans_executable(trans); 792 } else { 793 bool write_fault = kvm_is_write_fault(vcpu); 794 795 forward_fault = ((write_fault && !trans->writable) || 796 (!write_fault && !trans->readable)); 797 } 798 799 if (forward_fault) 800 trans->esr = esr_s2_fault(vcpu, trans->level, ESR_ELx_FSC_PERM); 801 802 return forward_fault; 803 } 804 805 int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2) 806 { 807 vcpu_write_sys_reg(vcpu, vcpu->arch.fault.far_el2, FAR_EL2); 808 vcpu_write_sys_reg(vcpu, vcpu->arch.fault.hpfar_el2, HPFAR_EL2); 809 810 return kvm_inject_nested_sync(vcpu, esr_el2); 811 } 812 813 static void invalidate_vncr(struct vncr_tlb *vt) 814 { 815 vt->valid = false; 816 if (vt->cpu != -1) 817 clear_fixmap(vncr_fixmap(vt->cpu)); 818 } 819 820 static void kvm_invalidate_vncr_ipa(struct kvm *kvm, u64 start, u64 end) 821 { 822 struct kvm_vcpu *vcpu; 823 unsigned long i; 824 825 lockdep_assert_held_write(&kvm->mmu_lock); 826 827 if (!kvm_has_feat(kvm, ID_AA64MMFR4_EL1, NV_frac, NV2_ONLY)) 828 return; 829 830 kvm_for_each_vcpu(i, vcpu, kvm) { 831 struct vncr_tlb *vt = vcpu->arch.vncr_tlb; 832 u64 ipa_start, ipa_end, ipa_size; 833 834 /* 835 * Careful here: We end-up here from an MMU notifier, 836 * and this can race against a vcpu not being onlined 837 * yet, without the pseudo-TLB being allocated. 838 * 839 * Skip those, as they obviously don't participate in 840 * the invalidation at this stage. 841 */ 842 if (!vt) 843 continue; 844 845 if (!vt->valid) 846 continue; 847 848 ipa_size = ttl_to_size(pgshift_level_to_ttl(vt->wi.pgshift, 849 vt->wr.level)); 850 ipa_start = vt->wr.pa & (ipa_size - 1); 851 ipa_end = ipa_start + ipa_size; 852 853 if (ipa_end <= start || ipa_start >= end) 854 continue; 855 856 invalidate_vncr(vt); 857 } 858 } 859 860 struct s1e2_tlbi_scope { 861 enum { 862 TLBI_ALL, 863 TLBI_VA, 864 TLBI_VAA, 865 TLBI_ASID, 866 } type; 867 868 u16 asid; 869 u64 va; 870 u64 size; 871 }; 872 873 static void invalidate_vncr_va(struct kvm *kvm, 874 struct s1e2_tlbi_scope *scope) 875 { 876 struct kvm_vcpu *vcpu; 877 unsigned long i; 878 879 lockdep_assert_held_write(&kvm->mmu_lock); 880 881 kvm_for_each_vcpu(i, vcpu, kvm) { 882 struct vncr_tlb *vt = vcpu->arch.vncr_tlb; 883 u64 va_start, va_end, va_size; 884 885 if (!vt->valid) 886 continue; 887 888 va_size = ttl_to_size(pgshift_level_to_ttl(vt->wi.pgshift, 889 vt->wr.level)); 890 va_start = vt->gva & (va_size - 1); 891 va_end = va_start + va_size; 892 893 switch (scope->type) { 894 case TLBI_ALL: 895 break; 896 897 case TLBI_VA: 898 if (va_end <= scope->va || 899 va_start >= (scope->va + scope->size)) 900 continue; 901 if (vt->wr.nG && vt->wr.asid != scope->asid) 902 continue; 903 break; 904 905 case TLBI_VAA: 906 if (va_end <= scope->va || 907 va_start >= (scope->va + scope->size)) 908 continue; 909 break; 910 911 case TLBI_ASID: 912 if (!vt->wr.nG || vt->wr.asid != scope->asid) 913 continue; 914 break; 915 } 916 917 invalidate_vncr(vt); 918 } 919 } 920 921 #define tlbi_va_s1_to_va(v) (u64)sign_extend64((v) << 12, 48) 922 923 static void compute_s1_tlbi_range(struct kvm_vcpu *vcpu, u32 inst, u64 val, 924 struct s1e2_tlbi_scope *scope) 925 { 926 switch (inst) { 927 case OP_TLBI_ALLE2: 928 case OP_TLBI_ALLE2IS: 929 case OP_TLBI_ALLE2OS: 930 case OP_TLBI_VMALLE1: 931 case OP_TLBI_VMALLE1IS: 932 case OP_TLBI_VMALLE1OS: 933 case OP_TLBI_ALLE2NXS: 934 case OP_TLBI_ALLE2ISNXS: 935 case OP_TLBI_ALLE2OSNXS: 936 case OP_TLBI_VMALLE1NXS: 937 case OP_TLBI_VMALLE1ISNXS: 938 case OP_TLBI_VMALLE1OSNXS: 939 scope->type = TLBI_ALL; 940 break; 941 case OP_TLBI_VAE2: 942 case OP_TLBI_VAE2IS: 943 case OP_TLBI_VAE2OS: 944 case OP_TLBI_VAE1: 945 case OP_TLBI_VAE1IS: 946 case OP_TLBI_VAE1OS: 947 case OP_TLBI_VAE2NXS: 948 case OP_TLBI_VAE2ISNXS: 949 case OP_TLBI_VAE2OSNXS: 950 case OP_TLBI_VAE1NXS: 951 case OP_TLBI_VAE1ISNXS: 952 case OP_TLBI_VAE1OSNXS: 953 case OP_TLBI_VALE2: 954 case OP_TLBI_VALE2IS: 955 case OP_TLBI_VALE2OS: 956 case OP_TLBI_VALE1: 957 case OP_TLBI_VALE1IS: 958 case OP_TLBI_VALE1OS: 959 case OP_TLBI_VALE2NXS: 960 case OP_TLBI_VALE2ISNXS: 961 case OP_TLBI_VALE2OSNXS: 962 case OP_TLBI_VALE1NXS: 963 case OP_TLBI_VALE1ISNXS: 964 case OP_TLBI_VALE1OSNXS: 965 scope->type = TLBI_VA; 966 scope->size = ttl_to_size(FIELD_GET(TLBI_TTL_MASK, val)); 967 if (!scope->size) 968 scope->size = SZ_1G; 969 scope->va = tlbi_va_s1_to_va(val) & ~(scope->size - 1); 970 scope->asid = FIELD_GET(TLBIR_ASID_MASK, val); 971 break; 972 case OP_TLBI_ASIDE1: 973 case OP_TLBI_ASIDE1IS: 974 case OP_TLBI_ASIDE1OS: 975 case OP_TLBI_ASIDE1NXS: 976 case OP_TLBI_ASIDE1ISNXS: 977 case OP_TLBI_ASIDE1OSNXS: 978 scope->type = TLBI_ASID; 979 scope->asid = FIELD_GET(TLBIR_ASID_MASK, val); 980 break; 981 case OP_TLBI_VAAE1: 982 case OP_TLBI_VAAE1IS: 983 case OP_TLBI_VAAE1OS: 984 case OP_TLBI_VAAE1NXS: 985 case OP_TLBI_VAAE1ISNXS: 986 case OP_TLBI_VAAE1OSNXS: 987 case OP_TLBI_VAALE1: 988 case OP_TLBI_VAALE1IS: 989 case OP_TLBI_VAALE1OS: 990 case OP_TLBI_VAALE1NXS: 991 case OP_TLBI_VAALE1ISNXS: 992 case OP_TLBI_VAALE1OSNXS: 993 scope->type = TLBI_VAA; 994 scope->size = ttl_to_size(FIELD_GET(TLBI_TTL_MASK, val)); 995 if (!scope->size) 996 scope->size = SZ_1G; 997 scope->va = tlbi_va_s1_to_va(val) & ~(scope->size - 1); 998 break; 999 case OP_TLBI_RVAE2: 1000 case OP_TLBI_RVAE2IS: 1001 case OP_TLBI_RVAE2OS: 1002 case OP_TLBI_RVAE1: 1003 case OP_TLBI_RVAE1IS: 1004 case OP_TLBI_RVAE1OS: 1005 case OP_TLBI_RVAE2NXS: 1006 case OP_TLBI_RVAE2ISNXS: 1007 case OP_TLBI_RVAE2OSNXS: 1008 case OP_TLBI_RVAE1NXS: 1009 case OP_TLBI_RVAE1ISNXS: 1010 case OP_TLBI_RVAE1OSNXS: 1011 case OP_TLBI_RVALE2: 1012 case OP_TLBI_RVALE2IS: 1013 case OP_TLBI_RVALE2OS: 1014 case OP_TLBI_RVALE1: 1015 case OP_TLBI_RVALE1IS: 1016 case OP_TLBI_RVALE1OS: 1017 case OP_TLBI_RVALE2NXS: 1018 case OP_TLBI_RVALE2ISNXS: 1019 case OP_TLBI_RVALE2OSNXS: 1020 case OP_TLBI_RVALE1NXS: 1021 case OP_TLBI_RVALE1ISNXS: 1022 case OP_TLBI_RVALE1OSNXS: 1023 scope->type = TLBI_VA; 1024 scope->va = decode_range_tlbi(val, &scope->size, &scope->asid); 1025 break; 1026 case OP_TLBI_RVAAE1: 1027 case OP_TLBI_RVAAE1IS: 1028 case OP_TLBI_RVAAE1OS: 1029 case OP_TLBI_RVAAE1NXS: 1030 case OP_TLBI_RVAAE1ISNXS: 1031 case OP_TLBI_RVAAE1OSNXS: 1032 case OP_TLBI_RVAALE1: 1033 case OP_TLBI_RVAALE1IS: 1034 case OP_TLBI_RVAALE1OS: 1035 case OP_TLBI_RVAALE1NXS: 1036 case OP_TLBI_RVAALE1ISNXS: 1037 case OP_TLBI_RVAALE1OSNXS: 1038 scope->type = TLBI_VAA; 1039 scope->va = decode_range_tlbi(val, &scope->size, NULL); 1040 break; 1041 } 1042 } 1043 1044 void kvm_handle_s1e2_tlbi(struct kvm_vcpu *vcpu, u32 inst, u64 val) 1045 { 1046 struct s1e2_tlbi_scope scope = {}; 1047 1048 compute_s1_tlbi_range(vcpu, inst, val, &scope); 1049 1050 guard(write_lock)(&vcpu->kvm->mmu_lock); 1051 invalidate_vncr_va(vcpu->kvm, &scope); 1052 } 1053 1054 void kvm_nested_s2_wp(struct kvm *kvm) 1055 { 1056 int i; 1057 1058 lockdep_assert_held_write(&kvm->mmu_lock); 1059 1060 for (i = 0; i < kvm->arch.nested_mmus_size; i++) { 1061 struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; 1062 1063 if (kvm_s2_mmu_valid(mmu)) 1064 kvm_stage2_wp_range(mmu, 0, kvm_phys_size(mmu)); 1065 } 1066 1067 kvm_invalidate_vncr_ipa(kvm, 0, BIT(kvm->arch.mmu.pgt->ia_bits)); 1068 } 1069 1070 void kvm_nested_s2_unmap(struct kvm *kvm, bool may_block) 1071 { 1072 int i; 1073 1074 lockdep_assert_held_write(&kvm->mmu_lock); 1075 1076 for (i = 0; i < kvm->arch.nested_mmus_size; i++) { 1077 struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; 1078 1079 if (kvm_s2_mmu_valid(mmu)) 1080 kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu), may_block); 1081 } 1082 1083 kvm_invalidate_vncr_ipa(kvm, 0, BIT(kvm->arch.mmu.pgt->ia_bits)); 1084 } 1085 1086 void kvm_nested_s2_flush(struct kvm *kvm) 1087 { 1088 int i; 1089 1090 lockdep_assert_held_write(&kvm->mmu_lock); 1091 1092 for (i = 0; i < kvm->arch.nested_mmus_size; i++) { 1093 struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; 1094 1095 if (kvm_s2_mmu_valid(mmu)) 1096 kvm_stage2_flush_range(mmu, 0, kvm_phys_size(mmu)); 1097 } 1098 } 1099 1100 void kvm_arch_flush_shadow_all(struct kvm *kvm) 1101 { 1102 int i; 1103 1104 for (i = 0; i < kvm->arch.nested_mmus_size; i++) { 1105 struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; 1106 1107 if (!WARN_ON(atomic_read(&mmu->refcnt))) 1108 kvm_free_stage2_pgd(mmu); 1109 } 1110 kvfree(kvm->arch.nested_mmus); 1111 kvm->arch.nested_mmus = NULL; 1112 kvm->arch.nested_mmus_size = 0; 1113 kvm_uninit_stage2_mmu(kvm); 1114 } 1115 1116 /* 1117 * Dealing with VNCR_EL2 exposed by the *guest* is a complicated matter: 1118 * 1119 * - We introduce an internal representation of a vcpu-private TLB, 1120 * representing the mapping between the guest VA contained in VNCR_EL2, 1121 * the IPA the guest's EL2 PTs point to, and the actual PA this lives at. 1122 * 1123 * - On translation fault from a nested VNCR access, we create such a TLB. 1124 * If there is no mapping to describe, the guest inherits the fault. 1125 * Crucially, no actual mapping is done at this stage. 1126 * 1127 * - On vcpu_load() in a non-HYP context with HCR_EL2.NV==1, if the above 1128 * TLB exists, we map it in the fixmap for this CPU, and run with it. We 1129 * have to respect the permissions dictated by the guest, but not the 1130 * memory type (FWB is a must). 1131 * 1132 * - Note that we usually don't do a vcpu_load() on the back of a fault 1133 * (unless we are preempted), so the resolution of a translation fault 1134 * must go via a request that will map the VNCR page in the fixmap. 1135 * vcpu_load() might as well use the same mechanism. 1136 * 1137 * - On vcpu_put() in a non-HYP context with HCR_EL2.NV==1, if the TLB was 1138 * mapped, we unmap it. Yes it is that simple. The TLB still exists 1139 * though, and may be reused at a later load. 1140 * 1141 * - On permission fault, we simply forward the fault to the guest's EL2. 1142 * Get out of my way. 1143 * 1144 * - On any TLBI for the EL2&0 translation regime, we must find any TLB that 1145 * intersects with the TLBI request, invalidate it, and unmap the page 1146 * from the fixmap. Because we need to look at all the vcpu-private TLBs, 1147 * this requires some wide-ranging locking to ensure that nothing races 1148 * against it. This may require some refcounting to avoid the search when 1149 * no such TLB is present. 1150 * 1151 * - On MMU notifiers, we must invalidate our TLB in a similar way, but 1152 * looking at the IPA instead. The funny part is that there may not be a 1153 * stage-2 mapping for this page if L1 hasn't accessed it using LD/ST 1154 * instructions. 1155 */ 1156 1157 int kvm_vcpu_allocate_vncr_tlb(struct kvm_vcpu *vcpu) 1158 { 1159 if (!kvm_has_feat(vcpu->kvm, ID_AA64MMFR4_EL1, NV_frac, NV2_ONLY)) 1160 return 0; 1161 1162 vcpu->arch.vncr_tlb = kzalloc(sizeof(*vcpu->arch.vncr_tlb), 1163 GFP_KERNEL_ACCOUNT); 1164 if (!vcpu->arch.vncr_tlb) 1165 return -ENOMEM; 1166 1167 return 0; 1168 } 1169 1170 static u64 read_vncr_el2(struct kvm_vcpu *vcpu) 1171 { 1172 return (u64)sign_extend64(__vcpu_sys_reg(vcpu, VNCR_EL2), 48); 1173 } 1174 1175 static int kvm_translate_vncr(struct kvm_vcpu *vcpu) 1176 { 1177 bool write_fault, writable; 1178 unsigned long mmu_seq; 1179 struct vncr_tlb *vt; 1180 struct page *page; 1181 u64 va, pfn, gfn; 1182 int ret; 1183 1184 vt = vcpu->arch.vncr_tlb; 1185 1186 /* 1187 * If we're about to walk the EL2 S1 PTs, we must invalidate the 1188 * current TLB, as it could be sampled from another vcpu doing a 1189 * TLBI *IS. A real CPU wouldn't do that, but we only keep a single 1190 * translation, so not much of a choice. 1191 * 1192 * We also prepare the next walk wilst we're at it. 1193 */ 1194 scoped_guard(write_lock, &vcpu->kvm->mmu_lock) { 1195 invalidate_vncr(vt); 1196 1197 vt->wi = (struct s1_walk_info) { 1198 .regime = TR_EL20, 1199 .as_el0 = false, 1200 .pan = false, 1201 }; 1202 vt->wr = (struct s1_walk_result){}; 1203 } 1204 1205 guard(srcu)(&vcpu->kvm->srcu); 1206 1207 va = read_vncr_el2(vcpu); 1208 1209 ret = __kvm_translate_va(vcpu, &vt->wi, &vt->wr, va); 1210 if (ret) 1211 return ret; 1212 1213 write_fault = kvm_is_write_fault(vcpu); 1214 1215 mmu_seq = vcpu->kvm->mmu_invalidate_seq; 1216 smp_rmb(); 1217 1218 gfn = vt->wr.pa >> PAGE_SHIFT; 1219 pfn = kvm_faultin_pfn(vcpu, gfn, write_fault, &writable, &page); 1220 if (is_error_noslot_pfn(pfn) || (write_fault && !writable)) 1221 return -EFAULT; 1222 1223 scoped_guard(write_lock, &vcpu->kvm->mmu_lock) { 1224 if (mmu_invalidate_retry(vcpu->kvm, mmu_seq)) 1225 return -EAGAIN; 1226 1227 vt->gva = va; 1228 vt->hpa = pfn << PAGE_SHIFT; 1229 vt->valid = true; 1230 vt->cpu = -1; 1231 1232 kvm_make_request(KVM_REQ_MAP_L1_VNCR_EL2, vcpu); 1233 kvm_release_faultin_page(vcpu->kvm, page, false, vt->wr.pw); 1234 } 1235 1236 if (vt->wr.pw) 1237 mark_page_dirty(vcpu->kvm, gfn); 1238 1239 return 0; 1240 } 1241 1242 static void inject_vncr_perm(struct kvm_vcpu *vcpu) 1243 { 1244 struct vncr_tlb *vt = vcpu->arch.vncr_tlb; 1245 u64 esr = kvm_vcpu_get_esr(vcpu); 1246 1247 /* Adjust the fault level to reflect that of the guest's */ 1248 esr &= ~ESR_ELx_FSC; 1249 esr |= FIELD_PREP(ESR_ELx_FSC, 1250 ESR_ELx_FSC_PERM_L(vt->wr.level)); 1251 1252 kvm_inject_nested_sync(vcpu, esr); 1253 } 1254 1255 static bool kvm_vncr_tlb_lookup(struct kvm_vcpu *vcpu) 1256 { 1257 struct vncr_tlb *vt = vcpu->arch.vncr_tlb; 1258 1259 lockdep_assert_held_read(&vcpu->kvm->mmu_lock); 1260 1261 if (!vt->valid) 1262 return false; 1263 1264 if (read_vncr_el2(vcpu) != vt->gva) 1265 return false; 1266 1267 if (vt->wr.nG) { 1268 u64 tcr = vcpu_read_sys_reg(vcpu, TCR_EL2); 1269 u64 ttbr = ((tcr & TCR_A1) ? 1270 vcpu_read_sys_reg(vcpu, TTBR1_EL2) : 1271 vcpu_read_sys_reg(vcpu, TTBR0_EL2)); 1272 u16 asid; 1273 1274 asid = FIELD_GET(TTBR_ASID_MASK, ttbr); 1275 if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) || 1276 !(tcr & TCR_ASID16)) 1277 asid &= GENMASK(7, 0); 1278 1279 return asid != vt->wr.asid; 1280 } 1281 1282 return true; 1283 } 1284 1285 int kvm_handle_vncr_abort(struct kvm_vcpu *vcpu) 1286 { 1287 struct vncr_tlb *vt = vcpu->arch.vncr_tlb; 1288 u64 esr = kvm_vcpu_get_esr(vcpu); 1289 1290 BUG_ON(!(esr & ESR_ELx_VNCR_SHIFT)); 1291 1292 if (esr_fsc_is_permission_fault(esr)) { 1293 inject_vncr_perm(vcpu); 1294 } else if (esr_fsc_is_translation_fault(esr)) { 1295 bool valid; 1296 int ret; 1297 1298 scoped_guard(read_lock, &vcpu->kvm->mmu_lock) 1299 valid = kvm_vncr_tlb_lookup(vcpu); 1300 1301 if (!valid) 1302 ret = kvm_translate_vncr(vcpu); 1303 else 1304 ret = -EPERM; 1305 1306 switch (ret) { 1307 case -EAGAIN: 1308 case -ENOMEM: 1309 /* Let's try again... */ 1310 break; 1311 case -EFAULT: 1312 case -EINVAL: 1313 case -ENOENT: 1314 case -EACCES: 1315 /* 1316 * Translation failed, inject the corresponding 1317 * exception back to EL2. 1318 */ 1319 BUG_ON(!vt->wr.failed); 1320 1321 esr &= ~ESR_ELx_FSC; 1322 esr |= FIELD_PREP(ESR_ELx_FSC, vt->wr.fst); 1323 1324 kvm_inject_nested_sync(vcpu, esr); 1325 break; 1326 case -EPERM: 1327 /* Hack to deal with POE until we get kernel support */ 1328 inject_vncr_perm(vcpu); 1329 break; 1330 case 0: 1331 break; 1332 } 1333 } else { 1334 WARN_ONCE(1, "Unhandled VNCR abort, ESR=%llx\n", esr); 1335 } 1336 1337 return 1; 1338 } 1339 1340 static void kvm_map_l1_vncr(struct kvm_vcpu *vcpu) 1341 { 1342 struct vncr_tlb *vt = vcpu->arch.vncr_tlb; 1343 pgprot_t prot; 1344 1345 guard(preempt)(); 1346 guard(read_lock)(&vcpu->kvm->mmu_lock); 1347 1348 /* 1349 * The request to map VNCR may have raced against some other 1350 * event, such as an interrupt, and may not be valid anymore. 1351 */ 1352 if (is_hyp_ctxt(vcpu)) 1353 return; 1354 1355 /* 1356 * Check that the pseudo-TLB is valid and that VNCR_EL2 still 1357 * contains the expected value. If it doesn't, we simply bail out 1358 * without a mapping -- a transformed MSR/MRS will generate the 1359 * fault and allows us to populate the pseudo-TLB. 1360 */ 1361 if (!vt->valid) 1362 return; 1363 1364 if (read_vncr_el2(vcpu) != vt->gva) 1365 return; 1366 1367 if (vt->wr.nG) { 1368 u64 tcr = vcpu_read_sys_reg(vcpu, TCR_EL2); 1369 u64 ttbr = ((tcr & TCR_A1) ? 1370 vcpu_read_sys_reg(vcpu, TTBR1_EL2) : 1371 vcpu_read_sys_reg(vcpu, TTBR0_EL2)); 1372 u16 asid; 1373 1374 asid = FIELD_GET(TTBR_ASID_MASK, ttbr); 1375 if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) || 1376 !(tcr & TCR_ASID16)) 1377 asid &= GENMASK(7, 0); 1378 1379 if (asid != vt->wr.asid) 1380 return; 1381 } 1382 1383 vt->cpu = smp_processor_id(); 1384 1385 if (vt->wr.pw && vt->wr.pr) 1386 prot = PAGE_KERNEL; 1387 else if (vt->wr.pr) 1388 prot = PAGE_KERNEL_RO; 1389 else 1390 prot = PAGE_NONE; 1391 1392 /* 1393 * We can't map write-only (or no permission at all) in the kernel, 1394 * but the guest can do it if using POE, so we'll have to turn a 1395 * translation fault into a permission fault at runtime. 1396 * FIXME: WO doesn't work at all, need POE support in the kernel. 1397 */ 1398 if (pgprot_val(prot) != pgprot_val(PAGE_NONE)) { 1399 __set_fixmap(vncr_fixmap(vt->cpu), vt->hpa, prot); 1400 host_data_set_flag(L1_VNCR_MAPPED); 1401 atomic_inc(&vcpu->kvm->arch.vncr_map_count); 1402 } 1403 } 1404 1405 #define has_tgran_2(__r, __sz) \ 1406 ({ \ 1407 u64 _s1, _s2, _mmfr0 = __r; \ 1408 \ 1409 _s2 = SYS_FIELD_GET(ID_AA64MMFR0_EL1, \ 1410 TGRAN##__sz##_2, _mmfr0); \ 1411 \ 1412 _s1 = SYS_FIELD_GET(ID_AA64MMFR0_EL1, \ 1413 TGRAN##__sz, _mmfr0); \ 1414 \ 1415 ((_s2 != ID_AA64MMFR0_EL1_TGRAN##__sz##_2_NI && \ 1416 _s2 != ID_AA64MMFR0_EL1_TGRAN##__sz##_2_TGRAN##__sz) || \ 1417 (_s2 == ID_AA64MMFR0_EL1_TGRAN##__sz##_2_TGRAN##__sz && \ 1418 _s1 != ID_AA64MMFR0_EL1_TGRAN##__sz##_NI)); \ 1419 }) 1420 /* 1421 * Our emulated CPU doesn't support all the possible features. For the 1422 * sake of simplicity (and probably mental sanity), wipe out a number 1423 * of feature bits we don't intend to support for the time being. 1424 * This list should get updated as new features get added to the NV 1425 * support, and new extension to the architecture. 1426 */ 1427 u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val) 1428 { 1429 u64 orig_val = val; 1430 1431 switch (reg) { 1432 case SYS_ID_AA64ISAR0_EL1: 1433 /* Support everything but TME */ 1434 val &= ~ID_AA64ISAR0_EL1_TME; 1435 break; 1436 1437 case SYS_ID_AA64ISAR1_EL1: 1438 /* Support everything but LS64 and Spec Invalidation */ 1439 val &= ~(ID_AA64ISAR1_EL1_LS64 | 1440 ID_AA64ISAR1_EL1_SPECRES); 1441 break; 1442 1443 case SYS_ID_AA64PFR0_EL1: 1444 /* No RME, AMU, MPAM, or S-EL2 */ 1445 val &= ~(ID_AA64PFR0_EL1_RME | 1446 ID_AA64PFR0_EL1_AMU | 1447 ID_AA64PFR0_EL1_MPAM | 1448 ID_AA64PFR0_EL1_SEL2 | 1449 ID_AA64PFR0_EL1_EL3 | 1450 ID_AA64PFR0_EL1_EL2 | 1451 ID_AA64PFR0_EL1_EL1 | 1452 ID_AA64PFR0_EL1_EL0); 1453 /* 64bit only at any EL */ 1454 val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, EL0, IMP); 1455 val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, EL1, IMP); 1456 val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, EL2, IMP); 1457 val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, EL3, IMP); 1458 break; 1459 1460 case SYS_ID_AA64PFR1_EL1: 1461 /* Only support BTI, SSBS, CSV2_frac */ 1462 val &= (ID_AA64PFR1_EL1_BT | 1463 ID_AA64PFR1_EL1_SSBS | 1464 ID_AA64PFR1_EL1_CSV2_frac); 1465 break; 1466 1467 case SYS_ID_AA64MMFR0_EL1: 1468 /* Hide ExS, Secure Memory */ 1469 val &= ~(ID_AA64MMFR0_EL1_EXS | 1470 ID_AA64MMFR0_EL1_TGRAN4_2 | 1471 ID_AA64MMFR0_EL1_TGRAN16_2 | 1472 ID_AA64MMFR0_EL1_TGRAN64_2 | 1473 ID_AA64MMFR0_EL1_SNSMEM); 1474 1475 /* Hide CNTPOFF if present */ 1476 val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64MMFR0_EL1, ECV, IMP); 1477 1478 /* Disallow unsupported S2 page sizes */ 1479 switch (PAGE_SIZE) { 1480 case SZ_64K: 1481 val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN16_2, NI); 1482 fallthrough; 1483 case SZ_16K: 1484 val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN4_2, NI); 1485 fallthrough; 1486 case SZ_4K: 1487 /* Support everything */ 1488 break; 1489 } 1490 1491 /* 1492 * Since we can't support a guest S2 page size smaller 1493 * than the host's own page size (due to KVM only 1494 * populating its own S2 using the kernel's page 1495 * size), advertise the limitation using FEAT_GTG. 1496 */ 1497 switch (PAGE_SIZE) { 1498 case SZ_4K: 1499 if (has_tgran_2(orig_val, 4)) 1500 val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN4_2, IMP); 1501 fallthrough; 1502 case SZ_16K: 1503 if (has_tgran_2(orig_val, 16)) 1504 val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN16_2, IMP); 1505 fallthrough; 1506 case SZ_64K: 1507 if (has_tgran_2(orig_val, 64)) 1508 val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN64_2, IMP); 1509 break; 1510 } 1511 1512 /* Cap PARange to 48bits */ 1513 val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64MMFR0_EL1, PARANGE, 48); 1514 break; 1515 1516 case SYS_ID_AA64MMFR1_EL1: 1517 val &= (ID_AA64MMFR1_EL1_HCX | 1518 ID_AA64MMFR1_EL1_PAN | 1519 ID_AA64MMFR1_EL1_LO | 1520 ID_AA64MMFR1_EL1_HPDS | 1521 ID_AA64MMFR1_EL1_VH | 1522 ID_AA64MMFR1_EL1_VMIDBits); 1523 /* FEAT_E2H0 implies no VHE */ 1524 if (test_bit(KVM_ARM_VCPU_HAS_EL2_E2H0, kvm->arch.vcpu_features)) 1525 val &= ~ID_AA64MMFR1_EL1_VH; 1526 break; 1527 1528 case SYS_ID_AA64MMFR2_EL1: 1529 val &= ~(ID_AA64MMFR2_EL1_BBM | 1530 ID_AA64MMFR2_EL1_TTL | 1531 GENMASK_ULL(47, 44) | 1532 ID_AA64MMFR2_EL1_ST | 1533 ID_AA64MMFR2_EL1_CCIDX | 1534 ID_AA64MMFR2_EL1_VARange); 1535 1536 /* Force TTL support */ 1537 val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR2_EL1, TTL, IMP); 1538 break; 1539 1540 case SYS_ID_AA64MMFR4_EL1: 1541 /* 1542 * You get EITHER 1543 * 1544 * - FEAT_VHE without FEAT_E2H0 1545 * - FEAT_NV limited to FEAT_NV2 1546 * - HCR_EL2.NV1 being RES0 1547 * 1548 * OR 1549 * 1550 * - FEAT_E2H0 without FEAT_VHE nor FEAT_NV 1551 * 1552 * Life is too short for anything else. 1553 */ 1554 if (test_bit(KVM_ARM_VCPU_HAS_EL2_E2H0, kvm->arch.vcpu_features)) { 1555 val = 0; 1556 } else { 1557 val = SYS_FIELD_PREP_ENUM(ID_AA64MMFR4_EL1, NV_frac, NV2_ONLY); 1558 val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR4_EL1, E2H0, NI_NV1); 1559 } 1560 break; 1561 1562 case SYS_ID_AA64DFR0_EL1: 1563 /* Only limited support for PMU, Debug, BPs, WPs, and HPMN0 */ 1564 val &= (ID_AA64DFR0_EL1_PMUVer | 1565 ID_AA64DFR0_EL1_WRPs | 1566 ID_AA64DFR0_EL1_BRPs | 1567 ID_AA64DFR0_EL1_DebugVer| 1568 ID_AA64DFR0_EL1_HPMN0); 1569 1570 /* Cap Debug to ARMv8.1 */ 1571 val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64DFR0_EL1, DebugVer, VHE); 1572 break; 1573 } 1574 1575 return val; 1576 } 1577 1578 u64 kvm_vcpu_apply_reg_masks(const struct kvm_vcpu *vcpu, 1579 enum vcpu_sysreg sr, u64 v) 1580 { 1581 struct kvm_sysreg_masks *masks; 1582 1583 masks = vcpu->kvm->arch.sysreg_masks; 1584 1585 if (masks) { 1586 sr -= __SANITISED_REG_START__; 1587 1588 v &= ~masks->mask[sr].res0; 1589 v |= masks->mask[sr].res1; 1590 } 1591 1592 return v; 1593 } 1594 1595 static __always_inline void set_sysreg_masks(struct kvm *kvm, int sr, u64 res0, u64 res1) 1596 { 1597 int i = sr - __SANITISED_REG_START__; 1598 1599 BUILD_BUG_ON(!__builtin_constant_p(sr)); 1600 BUILD_BUG_ON(sr < __SANITISED_REG_START__); 1601 BUILD_BUG_ON(sr >= NR_SYS_REGS); 1602 1603 kvm->arch.sysreg_masks->mask[i].res0 = res0; 1604 kvm->arch.sysreg_masks->mask[i].res1 = res1; 1605 } 1606 1607 int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu) 1608 { 1609 struct kvm *kvm = vcpu->kvm; 1610 u64 res0, res1; 1611 1612 lockdep_assert_held(&kvm->arch.config_lock); 1613 1614 if (kvm->arch.sysreg_masks) 1615 goto out; 1616 1617 kvm->arch.sysreg_masks = kzalloc(sizeof(*(kvm->arch.sysreg_masks)), 1618 GFP_KERNEL_ACCOUNT); 1619 if (!kvm->arch.sysreg_masks) 1620 return -ENOMEM; 1621 1622 /* VTTBR_EL2 */ 1623 res0 = res1 = 0; 1624 if (!kvm_has_feat_enum(kvm, ID_AA64MMFR1_EL1, VMIDBits, 16)) 1625 res0 |= GENMASK(63, 56); 1626 if (!kvm_has_feat(kvm, ID_AA64MMFR2_EL1, CnP, IMP)) 1627 res0 |= VTTBR_CNP_BIT; 1628 set_sysreg_masks(kvm, VTTBR_EL2, res0, res1); 1629 1630 /* VTCR_EL2 */ 1631 res0 = GENMASK(63, 32) | GENMASK(30, 20); 1632 res1 = BIT(31); 1633 set_sysreg_masks(kvm, VTCR_EL2, res0, res1); 1634 1635 /* VMPIDR_EL2 */ 1636 res0 = GENMASK(63, 40) | GENMASK(30, 24); 1637 res1 = BIT(31); 1638 set_sysreg_masks(kvm, VMPIDR_EL2, res0, res1); 1639 1640 /* HCR_EL2 */ 1641 get_reg_fixed_bits(kvm, HCR_EL2, &res0, &res1); 1642 set_sysreg_masks(kvm, HCR_EL2, res0, res1); 1643 1644 /* HCRX_EL2 */ 1645 get_reg_fixed_bits(kvm, HCRX_EL2, &res0, &res1); 1646 set_sysreg_masks(kvm, HCRX_EL2, res0, res1); 1647 1648 /* HFG[RW]TR_EL2 */ 1649 get_reg_fixed_bits(kvm, HFGRTR_EL2, &res0, &res1); 1650 set_sysreg_masks(kvm, HFGRTR_EL2, res0, res1); 1651 get_reg_fixed_bits(kvm, HFGWTR_EL2, &res0, &res1); 1652 set_sysreg_masks(kvm, HFGWTR_EL2, res0, res1); 1653 1654 /* HDFG[RW]TR_EL2 */ 1655 get_reg_fixed_bits(kvm, HDFGRTR_EL2, &res0, &res1); 1656 set_sysreg_masks(kvm, HDFGRTR_EL2, res0, res1); 1657 get_reg_fixed_bits(kvm, HDFGWTR_EL2, &res0, &res1); 1658 set_sysreg_masks(kvm, HDFGWTR_EL2, res0, res1); 1659 1660 /* HFGITR_EL2 */ 1661 get_reg_fixed_bits(kvm, HFGITR_EL2, &res0, &res1); 1662 set_sysreg_masks(kvm, HFGITR_EL2, res0, res1); 1663 1664 /* HAFGRTR_EL2 - not a lot to see here */ 1665 get_reg_fixed_bits(kvm, HAFGRTR_EL2, &res0, &res1); 1666 set_sysreg_masks(kvm, HAFGRTR_EL2, res0, res1); 1667 1668 /* HFG[RW]TR2_EL2 */ 1669 get_reg_fixed_bits(kvm, HFGRTR2_EL2, &res0, &res1); 1670 set_sysreg_masks(kvm, HFGRTR2_EL2, res0, res1); 1671 get_reg_fixed_bits(kvm, HFGWTR2_EL2, &res0, &res1); 1672 set_sysreg_masks(kvm, HFGWTR2_EL2, res0, res1); 1673 1674 /* HDFG[RW]TR2_EL2 */ 1675 get_reg_fixed_bits(kvm, HDFGRTR2_EL2, &res0, &res1); 1676 set_sysreg_masks(kvm, HDFGRTR2_EL2, res0, res1); 1677 get_reg_fixed_bits(kvm, HDFGWTR2_EL2, &res0, &res1); 1678 set_sysreg_masks(kvm, HDFGWTR2_EL2, res0, res1); 1679 1680 /* HFGITR2_EL2 */ 1681 get_reg_fixed_bits(kvm, HFGITR2_EL2, &res0, &res1); 1682 set_sysreg_masks(kvm, HFGITR2_EL2, res0, res1); 1683 1684 /* TCR2_EL2 */ 1685 get_reg_fixed_bits(kvm, TCR2_EL2, &res0, &res1); 1686 set_sysreg_masks(kvm, TCR2_EL2, res0, res1); 1687 1688 /* SCTLR_EL1 */ 1689 get_reg_fixed_bits(kvm, SCTLR_EL1, &res0, &res1); 1690 set_sysreg_masks(kvm, SCTLR_EL1, res0, res1); 1691 1692 /* SCTLR2_ELx */ 1693 get_reg_fixed_bits(kvm, SCTLR2_EL1, &res0, &res1); 1694 set_sysreg_masks(kvm, SCTLR2_EL1, res0, res1); 1695 get_reg_fixed_bits(kvm, SCTLR2_EL2, &res0, &res1); 1696 set_sysreg_masks(kvm, SCTLR2_EL2, res0, res1); 1697 1698 /* MDCR_EL2 */ 1699 get_reg_fixed_bits(kvm, MDCR_EL2, &res0, &res1); 1700 set_sysreg_masks(kvm, MDCR_EL2, res0, res1); 1701 1702 /* CNTHCTL_EL2 */ 1703 res0 = GENMASK(63, 20); 1704 res1 = 0; 1705 if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, RME, IMP)) 1706 res0 |= CNTHCTL_CNTPMASK | CNTHCTL_CNTVMASK; 1707 if (!kvm_has_feat(kvm, ID_AA64MMFR0_EL1, ECV, CNTPOFF)) { 1708 res0 |= CNTHCTL_ECV; 1709 if (!kvm_has_feat(kvm, ID_AA64MMFR0_EL1, ECV, IMP)) 1710 res0 |= (CNTHCTL_EL1TVT | CNTHCTL_EL1TVCT | 1711 CNTHCTL_EL1NVPCT | CNTHCTL_EL1NVVCT); 1712 } 1713 if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, VH, IMP)) 1714 res0 |= GENMASK(11, 8); 1715 set_sysreg_masks(kvm, CNTHCTL_EL2, res0, res1); 1716 1717 /* ICH_HCR_EL2 */ 1718 res0 = ICH_HCR_EL2_RES0; 1719 res1 = ICH_HCR_EL2_RES1; 1720 if (!(kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_EL2_TDS)) 1721 res0 |= ICH_HCR_EL2_TDIR; 1722 /* No GICv4 is presented to the guest */ 1723 res0 |= ICH_HCR_EL2_DVIM | ICH_HCR_EL2_vSGIEOICount; 1724 set_sysreg_masks(kvm, ICH_HCR_EL2, res0, res1); 1725 1726 /* VNCR_EL2 */ 1727 set_sysreg_masks(kvm, VNCR_EL2, VNCR_EL2_RES0, VNCR_EL2_RES1); 1728 1729 out: 1730 for (enum vcpu_sysreg sr = __SANITISED_REG_START__; sr < NR_SYS_REGS; sr++) 1731 __vcpu_rmw_sys_reg(vcpu, sr, |=, 0); 1732 1733 return 0; 1734 } 1735 1736 void check_nested_vcpu_requests(struct kvm_vcpu *vcpu) 1737 { 1738 if (kvm_check_request(KVM_REQ_NESTED_S2_UNMAP, vcpu)) { 1739 struct kvm_s2_mmu *mmu = vcpu->arch.hw_mmu; 1740 1741 write_lock(&vcpu->kvm->mmu_lock); 1742 if (mmu->pending_unmap) { 1743 kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu), true); 1744 mmu->pending_unmap = false; 1745 } 1746 write_unlock(&vcpu->kvm->mmu_lock); 1747 } 1748 1749 if (kvm_check_request(KVM_REQ_MAP_L1_VNCR_EL2, vcpu)) 1750 kvm_map_l1_vncr(vcpu); 1751 1752 /* Must be last, as may switch context! */ 1753 if (kvm_check_request(KVM_REQ_GUEST_HYP_IRQ_PENDING, vcpu)) 1754 kvm_inject_nested_irq(vcpu); 1755 } 1756 1757 /* 1758 * One of the many architectural bugs in FEAT_NV2 is that the guest hypervisor 1759 * can write to HCR_EL2 behind our back, potentially changing the exception 1760 * routing / masking for even the host context. 1761 * 1762 * What follows is some slop to (1) react to exception routing / masking and (2) 1763 * preserve the pending SError state across translation regimes. 1764 */ 1765 void kvm_nested_flush_hwstate(struct kvm_vcpu *vcpu) 1766 { 1767 if (!vcpu_has_nv(vcpu)) 1768 return; 1769 1770 if (unlikely(vcpu_test_and_clear_flag(vcpu, NESTED_SERROR_PENDING))) 1771 kvm_inject_serror_esr(vcpu, vcpu_get_vsesr(vcpu)); 1772 } 1773 1774 void kvm_nested_sync_hwstate(struct kvm_vcpu *vcpu) 1775 { 1776 unsigned long *hcr = vcpu_hcr(vcpu); 1777 1778 if (!vcpu_has_nv(vcpu)) 1779 return; 1780 1781 /* 1782 * We previously decided that an SError was deliverable to the guest. 1783 * Reap the pending state from HCR_EL2 and... 1784 */ 1785 if (unlikely(__test_and_clear_bit(__ffs(HCR_VSE), hcr))) 1786 vcpu_set_flag(vcpu, NESTED_SERROR_PENDING); 1787 1788 /* 1789 * Re-attempt SError injection in case the deliverability has changed, 1790 * which is necessary to faithfully emulate WFI the case of a pending 1791 * SError being a wakeup condition. 1792 */ 1793 if (unlikely(vcpu_test_and_clear_flag(vcpu, NESTED_SERROR_PENDING))) 1794 kvm_inject_serror_esr(vcpu, vcpu_get_vsesr(vcpu)); 1795 } 1796