1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License, version 2, as 4 * published by the Free Software Foundation. 5 * 6 * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 7 */ 8 9 #include <linux/types.h> 10 #include <linux/string.h> 11 #include <linux/kvm.h> 12 #include <linux/kvm_host.h> 13 14 #include <asm/kvm_ppc.h> 15 #include <asm/kvm_book3s.h> 16 #include <asm/page.h> 17 #include <asm/mmu.h> 18 #include <asm/pgtable.h> 19 #include <asm/pgalloc.h> 20 #include <asm/pte-walk.h> 21 22 /* 23 * Supported radix tree geometry. 24 * Like p9, we support either 5 or 9 bits at the first (lowest) level, 25 * for a page size of 64k or 4k. 26 */ 27 static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 }; 28 29 int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, 30 struct kvmppc_pte *gpte, bool data, bool iswrite) 31 { 32 struct kvm *kvm = vcpu->kvm; 33 u32 pid; 34 int ret, level, ps; 35 __be64 prte, rpte; 36 unsigned long ptbl; 37 unsigned long root, pte, index; 38 unsigned long rts, bits, offset; 39 unsigned long gpa; 40 unsigned long proc_tbl_size; 41 42 /* Work out effective PID */ 43 switch (eaddr >> 62) { 44 case 0: 45 pid = vcpu->arch.pid; 46 break; 47 case 3: 48 pid = 0; 49 break; 50 default: 51 return -EINVAL; 52 } 53 proc_tbl_size = 1 << ((kvm->arch.process_table & PRTS_MASK) + 12); 54 if (pid * 16 >= proc_tbl_size) 55 return -EINVAL; 56 57 /* Read partition table to find root of tree for effective PID */ 58 ptbl = (kvm->arch.process_table & PRTB_MASK) + (pid * 16); 59 ret = kvm_read_guest(kvm, ptbl, &prte, sizeof(prte)); 60 if (ret) 61 return ret; 62 63 root = be64_to_cpu(prte); 64 rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) | 65 ((root & RTS2_MASK) >> RTS2_SHIFT); 66 bits = root & RPDS_MASK; 67 root = root & RPDB_MASK; 68 69 offset = rts + 31; 70 71 /* current implementations only support 52-bit space */ 72 if (offset != 52) 73 return -EINVAL; 74 75 for (level = 3; level >= 0; --level) { 76 if (level && bits != p9_supported_radix_bits[level]) 77 return -EINVAL; 78 if (level == 0 && !(bits == 5 || bits == 9)) 79 return -EINVAL; 80 offset -= bits; 81 index = (eaddr >> offset) & ((1UL << bits) - 1); 82 /* check that low bits of page table base are zero */ 83 if (root & ((1UL << (bits + 3)) - 1)) 84 return -EINVAL; 85 ret = kvm_read_guest(kvm, root + index * 8, 86 &rpte, sizeof(rpte)); 87 if (ret) 88 return ret; 89 pte = __be64_to_cpu(rpte); 90 if (!(pte & _PAGE_PRESENT)) 91 return -ENOENT; 92 if (pte & _PAGE_PTE) 93 break; 94 bits = pte & 0x1f; 95 root = pte & 0x0fffffffffffff00ul; 96 } 97 /* need a leaf at lowest level; 512GB pages not supported */ 98 if (level < 0 || level == 3) 99 return -EINVAL; 100 101 /* offset is now log base 2 of the page size */ 102 gpa = pte & 0x01fffffffffff000ul; 103 if (gpa & ((1ul << offset) - 1)) 104 return -EINVAL; 105 gpa += eaddr & ((1ul << offset) - 1); 106 for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps) 107 if (offset == mmu_psize_defs[ps].shift) 108 break; 109 gpte->page_size = ps; 110 111 gpte->eaddr = eaddr; 112 gpte->raddr = gpa; 113 114 /* Work out permissions */ 115 gpte->may_read = !!(pte & _PAGE_READ); 116 gpte->may_write = !!(pte & _PAGE_WRITE); 117 gpte->may_execute = !!(pte & _PAGE_EXEC); 118 if (kvmppc_get_msr(vcpu) & MSR_PR) { 119 if (pte & _PAGE_PRIVILEGED) { 120 gpte->may_read = 0; 121 gpte->may_write = 0; 122 gpte->may_execute = 0; 123 } 124 } else { 125 if (!(pte & _PAGE_PRIVILEGED)) { 126 /* Check AMR/IAMR to see if strict mode is in force */ 127 if (vcpu->arch.amr & (1ul << 62)) 128 gpte->may_read = 0; 129 if (vcpu->arch.amr & (1ul << 63)) 130 gpte->may_write = 0; 131 if (vcpu->arch.iamr & (1ul << 62)) 132 gpte->may_execute = 0; 133 } 134 } 135 136 return 0; 137 } 138 139 static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr, 140 unsigned int pshift) 141 { 142 unsigned long psize = PAGE_SIZE; 143 144 if (pshift) 145 psize = 1UL << pshift; 146 147 addr &= ~(psize - 1); 148 radix__flush_tlb_lpid_page(kvm->arch.lpid, addr, psize); 149 } 150 151 static void kvmppc_radix_flush_pwc(struct kvm *kvm) 152 { 153 radix__flush_pwc_lpid(kvm->arch.lpid); 154 } 155 156 static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep, 157 unsigned long clr, unsigned long set, 158 unsigned long addr, unsigned int shift) 159 { 160 return __radix_pte_update(ptep, clr, set); 161 } 162 163 void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr, 164 pte_t *ptep, pte_t pte) 165 { 166 radix__set_pte_at(kvm->mm, addr, ptep, pte, 0); 167 } 168 169 static struct kmem_cache *kvm_pte_cache; 170 static struct kmem_cache *kvm_pmd_cache; 171 172 static pte_t *kvmppc_pte_alloc(void) 173 { 174 return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); 175 } 176 177 static void kvmppc_pte_free(pte_t *ptep) 178 { 179 kmem_cache_free(kvm_pte_cache, ptep); 180 } 181 182 /* Like pmd_huge() and pmd_large(), but works regardless of config options */ 183 static inline int pmd_is_leaf(pmd_t pmd) 184 { 185 return !!(pmd_val(pmd) & _PAGE_PTE); 186 } 187 188 static pmd_t *kvmppc_pmd_alloc(void) 189 { 190 return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); 191 } 192 193 static void kvmppc_pmd_free(pmd_t *pmdp) 194 { 195 kmem_cache_free(kvm_pmd_cache, pmdp); 196 } 197 198 static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, 199 unsigned long gpa, unsigned int shift) 200 201 { 202 unsigned long page_size = 1ul << shift; 203 unsigned long old; 204 205 old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift); 206 kvmppc_radix_tlbie_page(kvm, gpa, shift); 207 if (old & _PAGE_DIRTY) { 208 unsigned long gfn = gpa >> PAGE_SHIFT; 209 struct kvm_memory_slot *memslot; 210 211 memslot = gfn_to_memslot(kvm, gfn); 212 if (memslot && memslot->dirty_bitmap) 213 kvmppc_update_dirty_map(memslot, gfn, page_size); 214 } 215 } 216 217 /* 218 * kvmppc_free_p?d are used to free existing page tables, and recursively 219 * descend and clear and free children. 220 * Callers are responsible for flushing the PWC. 221 * 222 * When page tables are being unmapped/freed as part of page fault path 223 * (full == false), ptes are not expected. There is code to unmap them 224 * and emit a warning if encountered, but there may already be data 225 * corruption due to the unexpected mappings. 226 */ 227 static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full) 228 { 229 if (full) { 230 memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE); 231 } else { 232 pte_t *p = pte; 233 unsigned long it; 234 235 for (it = 0; it < PTRS_PER_PTE; ++it, ++p) { 236 if (pte_val(*p) == 0) 237 continue; 238 WARN_ON_ONCE(1); 239 kvmppc_unmap_pte(kvm, p, 240 pte_pfn(*p) << PAGE_SHIFT, 241 PAGE_SHIFT); 242 } 243 } 244 245 kvmppc_pte_free(pte); 246 } 247 248 static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full) 249 { 250 unsigned long im; 251 pmd_t *p = pmd; 252 253 for (im = 0; im < PTRS_PER_PMD; ++im, ++p) { 254 if (!pmd_present(*p)) 255 continue; 256 if (pmd_is_leaf(*p)) { 257 if (full) { 258 pmd_clear(p); 259 } else { 260 WARN_ON_ONCE(1); 261 kvmppc_unmap_pte(kvm, (pte_t *)p, 262 pte_pfn(*(pte_t *)p) << PAGE_SHIFT, 263 PMD_SHIFT); 264 } 265 } else { 266 pte_t *pte; 267 268 pte = pte_offset_map(p, 0); 269 kvmppc_unmap_free_pte(kvm, pte, full); 270 pmd_clear(p); 271 } 272 } 273 kvmppc_pmd_free(pmd); 274 } 275 276 static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud) 277 { 278 unsigned long iu; 279 pud_t *p = pud; 280 281 for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) { 282 if (!pud_present(*p)) 283 continue; 284 if (pud_huge(*p)) { 285 pud_clear(p); 286 } else { 287 pmd_t *pmd; 288 289 pmd = pmd_offset(p, 0); 290 kvmppc_unmap_free_pmd(kvm, pmd, true); 291 pud_clear(p); 292 } 293 } 294 pud_free(kvm->mm, pud); 295 } 296 297 void kvmppc_free_radix(struct kvm *kvm) 298 { 299 unsigned long ig; 300 pgd_t *pgd; 301 302 if (!kvm->arch.pgtable) 303 return; 304 pgd = kvm->arch.pgtable; 305 for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) { 306 pud_t *pud; 307 308 if (!pgd_present(*pgd)) 309 continue; 310 pud = pud_offset(pgd, 0); 311 kvmppc_unmap_free_pud(kvm, pud); 312 pgd_clear(pgd); 313 } 314 pgd_free(kvm->mm, kvm->arch.pgtable); 315 kvm->arch.pgtable = NULL; 316 } 317 318 static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd, 319 unsigned long gpa) 320 { 321 pte_t *pte = pte_offset_kernel(pmd, 0); 322 323 /* 324 * Clearing the pmd entry then flushing the PWC ensures that the pte 325 * page no longer be cached by the MMU, so can be freed without 326 * flushing the PWC again. 327 */ 328 pmd_clear(pmd); 329 kvmppc_radix_flush_pwc(kvm); 330 331 kvmppc_unmap_free_pte(kvm, pte, false); 332 } 333 334 static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud, 335 unsigned long gpa) 336 { 337 pmd_t *pmd = pmd_offset(pud, 0); 338 339 /* 340 * Clearing the pud entry then flushing the PWC ensures that the pmd 341 * page and any children pte pages will no longer be cached by the MMU, 342 * so can be freed without flushing the PWC again. 343 */ 344 pud_clear(pud); 345 kvmppc_radix_flush_pwc(kvm); 346 347 kvmppc_unmap_free_pmd(kvm, pmd, false); 348 } 349 350 /* 351 * There are a number of bits which may differ between different faults to 352 * the same partition scope entry. RC bits, in the course of cleaning and 353 * aging. And the write bit can change, either the access could have been 354 * upgraded, or a read fault could happen concurrently with a write fault 355 * that sets those bits first. 356 */ 357 #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) 358 359 static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa, 360 unsigned int level, unsigned long mmu_seq) 361 { 362 pgd_t *pgd; 363 pud_t *pud, *new_pud = NULL; 364 pmd_t *pmd, *new_pmd = NULL; 365 pte_t *ptep, *new_ptep = NULL; 366 int ret; 367 368 /* Traverse the guest's 2nd-level tree, allocate new levels needed */ 369 pgd = kvm->arch.pgtable + pgd_index(gpa); 370 pud = NULL; 371 if (pgd_present(*pgd)) 372 pud = pud_offset(pgd, gpa); 373 else 374 new_pud = pud_alloc_one(kvm->mm, gpa); 375 376 pmd = NULL; 377 if (pud && pud_present(*pud) && !pud_huge(*pud)) 378 pmd = pmd_offset(pud, gpa); 379 else if (level <= 1) 380 new_pmd = kvmppc_pmd_alloc(); 381 382 if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd))) 383 new_ptep = kvmppc_pte_alloc(); 384 385 /* Check if we might have been invalidated; let the guest retry if so */ 386 spin_lock(&kvm->mmu_lock); 387 ret = -EAGAIN; 388 if (mmu_notifier_retry(kvm, mmu_seq)) 389 goto out_unlock; 390 391 /* Now traverse again under the lock and change the tree */ 392 ret = -ENOMEM; 393 if (pgd_none(*pgd)) { 394 if (!new_pud) 395 goto out_unlock; 396 pgd_populate(kvm->mm, pgd, new_pud); 397 new_pud = NULL; 398 } 399 pud = pud_offset(pgd, gpa); 400 if (pud_huge(*pud)) { 401 unsigned long hgpa = gpa & PUD_MASK; 402 403 /* Check if we raced and someone else has set the same thing */ 404 if (level == 2) { 405 if (pud_raw(*pud) == pte_raw(pte)) { 406 ret = 0; 407 goto out_unlock; 408 } 409 /* Valid 1GB page here already, add our extra bits */ 410 WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) & 411 PTE_BITS_MUST_MATCH); 412 kvmppc_radix_update_pte(kvm, (pte_t *)pud, 413 0, pte_val(pte), hgpa, PUD_SHIFT); 414 ret = 0; 415 goto out_unlock; 416 } 417 /* 418 * If we raced with another CPU which has just put 419 * a 1GB pte in after we saw a pmd page, try again. 420 */ 421 if (!new_pmd) { 422 ret = -EAGAIN; 423 goto out_unlock; 424 } 425 /* Valid 1GB page here already, remove it */ 426 kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT); 427 } 428 if (level == 2) { 429 if (!pud_none(*pud)) { 430 /* 431 * There's a page table page here, but we wanted to 432 * install a large page, so remove and free the page 433 * table page. 434 */ 435 kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa); 436 } 437 kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte); 438 ret = 0; 439 goto out_unlock; 440 } 441 if (pud_none(*pud)) { 442 if (!new_pmd) 443 goto out_unlock; 444 pud_populate(kvm->mm, pud, new_pmd); 445 new_pmd = NULL; 446 } 447 pmd = pmd_offset(pud, gpa); 448 if (pmd_is_leaf(*pmd)) { 449 unsigned long lgpa = gpa & PMD_MASK; 450 451 /* Check if we raced and someone else has set the same thing */ 452 if (level == 1) { 453 if (pmd_raw(*pmd) == pte_raw(pte)) { 454 ret = 0; 455 goto out_unlock; 456 } 457 /* Valid 2MB page here already, add our extra bits */ 458 WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) & 459 PTE_BITS_MUST_MATCH); 460 kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd), 461 0, pte_val(pte), lgpa, PMD_SHIFT); 462 ret = 0; 463 goto out_unlock; 464 } 465 466 /* 467 * If we raced with another CPU which has just put 468 * a 2MB pte in after we saw a pte page, try again. 469 */ 470 if (!new_ptep) { 471 ret = -EAGAIN; 472 goto out_unlock; 473 } 474 /* Valid 2MB page here already, remove it */ 475 kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT); 476 } 477 if (level == 1) { 478 if (!pmd_none(*pmd)) { 479 /* 480 * There's a page table page here, but we wanted to 481 * install a large page, so remove and free the page 482 * table page. 483 */ 484 kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa); 485 } 486 kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte); 487 ret = 0; 488 goto out_unlock; 489 } 490 if (pmd_none(*pmd)) { 491 if (!new_ptep) 492 goto out_unlock; 493 pmd_populate(kvm->mm, pmd, new_ptep); 494 new_ptep = NULL; 495 } 496 ptep = pte_offset_kernel(pmd, gpa); 497 if (pte_present(*ptep)) { 498 /* Check if someone else set the same thing */ 499 if (pte_raw(*ptep) == pte_raw(pte)) { 500 ret = 0; 501 goto out_unlock; 502 } 503 /* Valid page here already, add our extra bits */ 504 WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) & 505 PTE_BITS_MUST_MATCH); 506 kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0); 507 ret = 0; 508 goto out_unlock; 509 } 510 kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte); 511 ret = 0; 512 513 out_unlock: 514 spin_unlock(&kvm->mmu_lock); 515 if (new_pud) 516 pud_free(kvm->mm, new_pud); 517 if (new_pmd) 518 kvmppc_pmd_free(new_pmd); 519 if (new_ptep) 520 kvmppc_pte_free(new_ptep); 521 return ret; 522 } 523 524 int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 525 unsigned long ea, unsigned long dsisr) 526 { 527 struct kvm *kvm = vcpu->kvm; 528 unsigned long mmu_seq, pte_size; 529 unsigned long gpa, gfn, hva, pfn; 530 struct kvm_memory_slot *memslot; 531 struct page *page = NULL; 532 long ret; 533 bool writing; 534 bool upgrade_write = false; 535 bool *upgrade_p = &upgrade_write; 536 pte_t pte, *ptep; 537 unsigned long pgflags; 538 unsigned int shift, level; 539 540 /* Check for unusual errors */ 541 if (dsisr & DSISR_UNSUPP_MMU) { 542 pr_err("KVM: Got unsupported MMU fault\n"); 543 return -EFAULT; 544 } 545 if (dsisr & DSISR_BADACCESS) { 546 /* Reflect to the guest as DSI */ 547 pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr); 548 kvmppc_core_queue_data_storage(vcpu, ea, dsisr); 549 return RESUME_GUEST; 550 } 551 552 /* Translate the logical address and get the page */ 553 gpa = vcpu->arch.fault_gpa & ~0xfffUL; 554 gpa &= ~0xF000000000000000ul; 555 gfn = gpa >> PAGE_SHIFT; 556 if (!(dsisr & DSISR_PRTABLE_FAULT)) 557 gpa |= ea & 0xfff; 558 memslot = gfn_to_memslot(kvm, gfn); 559 560 /* No memslot means it's an emulated MMIO region */ 561 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) { 562 if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS | 563 DSISR_SET_RC)) { 564 /* 565 * Bad address in guest page table tree, or other 566 * unusual error - reflect it to the guest as DSI. 567 */ 568 kvmppc_core_queue_data_storage(vcpu, ea, dsisr); 569 return RESUME_GUEST; 570 } 571 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 572 dsisr & DSISR_ISSTORE); 573 } 574 575 writing = (dsisr & DSISR_ISSTORE) != 0; 576 if (memslot->flags & KVM_MEM_READONLY) { 577 if (writing) { 578 /* give the guest a DSI */ 579 dsisr = DSISR_ISSTORE | DSISR_PROTFAULT; 580 kvmppc_core_queue_data_storage(vcpu, ea, dsisr); 581 return RESUME_GUEST; 582 } 583 upgrade_p = NULL; 584 } 585 586 if (dsisr & DSISR_SET_RC) { 587 /* 588 * Need to set an R or C bit in the 2nd-level tables; 589 * since we are just helping out the hardware here, 590 * it is sufficient to do what the hardware does. 591 */ 592 pgflags = _PAGE_ACCESSED; 593 if (writing) 594 pgflags |= _PAGE_DIRTY; 595 /* 596 * We are walking the secondary page table here. We can do this 597 * without disabling irq. 598 */ 599 spin_lock(&kvm->mmu_lock); 600 ptep = __find_linux_pte(kvm->arch.pgtable, 601 gpa, NULL, &shift); 602 if (ptep && pte_present(*ptep) && 603 (!writing || pte_write(*ptep))) { 604 kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, 605 gpa, shift); 606 dsisr &= ~DSISR_SET_RC; 607 } 608 spin_unlock(&kvm->mmu_lock); 609 if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE | 610 DSISR_PROTFAULT | DSISR_SET_RC))) 611 return RESUME_GUEST; 612 } 613 614 /* used to check for invalidations in progress */ 615 mmu_seq = kvm->mmu_notifier_seq; 616 smp_rmb(); 617 618 /* 619 * Do a fast check first, since __gfn_to_pfn_memslot doesn't 620 * do it with !atomic && !async, which is how we call it. 621 * We always ask for write permission since the common case 622 * is that the page is writable. 623 */ 624 hva = gfn_to_hva_memslot(memslot, gfn); 625 if (upgrade_p && __get_user_pages_fast(hva, 1, 1, &page) == 1) { 626 pfn = page_to_pfn(page); 627 upgrade_write = true; 628 } else { 629 /* Call KVM generic code to do the slow-path check */ 630 pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, 631 writing, upgrade_p); 632 if (is_error_noslot_pfn(pfn)) 633 return -EFAULT; 634 page = NULL; 635 if (pfn_valid(pfn)) { 636 page = pfn_to_page(pfn); 637 if (PageReserved(page)) 638 page = NULL; 639 } 640 } 641 642 /* See if we can insert a 1GB or 2MB large PTE here */ 643 level = 0; 644 if (page && PageCompound(page)) { 645 pte_size = PAGE_SIZE << compound_order(compound_head(page)); 646 if (pte_size >= PUD_SIZE && 647 (gpa & (PUD_SIZE - PAGE_SIZE)) == 648 (hva & (PUD_SIZE - PAGE_SIZE))) { 649 level = 2; 650 pfn &= ~((PUD_SIZE >> PAGE_SHIFT) - 1); 651 } else if (pte_size >= PMD_SIZE && 652 (gpa & (PMD_SIZE - PAGE_SIZE)) == 653 (hva & (PMD_SIZE - PAGE_SIZE))) { 654 level = 1; 655 pfn &= ~((PMD_SIZE >> PAGE_SHIFT) - 1); 656 } 657 } 658 659 /* 660 * Compute the PTE value that we need to insert. 661 */ 662 if (page) { 663 pgflags = _PAGE_READ | _PAGE_EXEC | _PAGE_PRESENT | _PAGE_PTE | 664 _PAGE_ACCESSED; 665 if (writing || upgrade_write) 666 pgflags |= _PAGE_WRITE | _PAGE_DIRTY; 667 pte = pfn_pte(pfn, __pgprot(pgflags)); 668 } else { 669 /* 670 * Read the PTE from the process' radix tree and use that 671 * so we get the attribute bits. 672 */ 673 local_irq_disable(); 674 ptep = __find_linux_pte(vcpu->arch.pgdir, hva, NULL, &shift); 675 pte = *ptep; 676 local_irq_enable(); 677 if (shift == PUD_SHIFT && 678 (gpa & (PUD_SIZE - PAGE_SIZE)) == 679 (hva & (PUD_SIZE - PAGE_SIZE))) { 680 level = 2; 681 } else if (shift == PMD_SHIFT && 682 (gpa & (PMD_SIZE - PAGE_SIZE)) == 683 (hva & (PMD_SIZE - PAGE_SIZE))) { 684 level = 1; 685 } else if (shift && shift != PAGE_SHIFT) { 686 /* Adjust PFN */ 687 unsigned long mask = (1ul << shift) - PAGE_SIZE; 688 pte = __pte(pte_val(pte) | (hva & mask)); 689 } 690 pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED); 691 if (writing || upgrade_write) { 692 if (pte_val(pte) & _PAGE_WRITE) 693 pte = __pte(pte_val(pte) | _PAGE_DIRTY); 694 } else { 695 pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY)); 696 } 697 } 698 699 /* Allocate space in the tree and write the PTE */ 700 ret = kvmppc_create_pte(kvm, pte, gpa, level, mmu_seq); 701 702 if (page) { 703 if (!ret && (pte_val(pte) & _PAGE_WRITE)) 704 set_page_dirty_lock(page); 705 put_page(page); 706 } 707 708 if (ret == 0 || ret == -EAGAIN) 709 ret = RESUME_GUEST; 710 return ret; 711 } 712 713 /* Called with kvm->lock held */ 714 int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, 715 unsigned long gfn) 716 { 717 pte_t *ptep; 718 unsigned long gpa = gfn << PAGE_SHIFT; 719 unsigned int shift; 720 unsigned long old; 721 722 ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift); 723 if (ptep && pte_present(*ptep)) { 724 old = kvmppc_radix_update_pte(kvm, ptep, ~0UL, 0, 725 gpa, shift); 726 kvmppc_radix_tlbie_page(kvm, gpa, shift); 727 if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap) { 728 unsigned long npages = 1; 729 if (shift) 730 npages = 1ul << (shift - PAGE_SHIFT); 731 kvmppc_update_dirty_map(memslot, gfn, npages); 732 } 733 } 734 return 0; 735 } 736 737 /* Called with kvm->lock held */ 738 int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, 739 unsigned long gfn) 740 { 741 pte_t *ptep; 742 unsigned long gpa = gfn << PAGE_SHIFT; 743 unsigned int shift; 744 int ref = 0; 745 746 ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift); 747 if (ptep && pte_present(*ptep) && pte_young(*ptep)) { 748 kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0, 749 gpa, shift); 750 /* XXX need to flush tlb here? */ 751 ref = 1; 752 } 753 return ref; 754 } 755 756 /* Called with kvm->lock held */ 757 int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, 758 unsigned long gfn) 759 { 760 pte_t *ptep; 761 unsigned long gpa = gfn << PAGE_SHIFT; 762 unsigned int shift; 763 int ref = 0; 764 765 ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift); 766 if (ptep && pte_present(*ptep) && pte_young(*ptep)) 767 ref = 1; 768 return ref; 769 } 770 771 /* Returns the number of PAGE_SIZE pages that are dirty */ 772 static int kvm_radix_test_clear_dirty(struct kvm *kvm, 773 struct kvm_memory_slot *memslot, int pagenum) 774 { 775 unsigned long gfn = memslot->base_gfn + pagenum; 776 unsigned long gpa = gfn << PAGE_SHIFT; 777 pte_t *ptep; 778 unsigned int shift; 779 int ret = 0; 780 781 ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift); 782 if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) { 783 ret = 1; 784 if (shift) 785 ret = 1 << (shift - PAGE_SHIFT); 786 kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0, 787 gpa, shift); 788 kvmppc_radix_tlbie_page(kvm, gpa, shift); 789 } 790 return ret; 791 } 792 793 long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm, 794 struct kvm_memory_slot *memslot, unsigned long *map) 795 { 796 unsigned long i, j; 797 int npages; 798 799 for (i = 0; i < memslot->npages; i = j) { 800 npages = kvm_radix_test_clear_dirty(kvm, memslot, i); 801 802 /* 803 * Note that if npages > 0 then i must be a multiple of npages, 804 * since huge pages are only used to back the guest at guest 805 * real addresses that are a multiple of their size. 806 * Since we have at most one PTE covering any given guest 807 * real address, if npages > 1 we can skip to i + npages. 808 */ 809 j = i + 1; 810 if (npages) { 811 set_dirty_bits(map, i, npages); 812 j = i + npages; 813 } 814 } 815 return 0; 816 } 817 818 static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info, 819 int psize, int *indexp) 820 { 821 if (!mmu_psize_defs[psize].shift) 822 return; 823 info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift | 824 (mmu_psize_defs[psize].ap << 29); 825 ++(*indexp); 826 } 827 828 int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info) 829 { 830 int i; 831 832 if (!radix_enabled()) 833 return -EINVAL; 834 memset(info, 0, sizeof(*info)); 835 836 /* 4k page size */ 837 info->geometries[0].page_shift = 12; 838 info->geometries[0].level_bits[0] = 9; 839 for (i = 1; i < 4; ++i) 840 info->geometries[0].level_bits[i] = p9_supported_radix_bits[i]; 841 /* 64k page size */ 842 info->geometries[1].page_shift = 16; 843 for (i = 0; i < 4; ++i) 844 info->geometries[1].level_bits[i] = p9_supported_radix_bits[i]; 845 846 i = 0; 847 add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i); 848 add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i); 849 add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i); 850 add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i); 851 852 return 0; 853 } 854 855 int kvmppc_init_vm_radix(struct kvm *kvm) 856 { 857 kvm->arch.pgtable = pgd_alloc(kvm->mm); 858 if (!kvm->arch.pgtable) 859 return -ENOMEM; 860 return 0; 861 } 862 863 static void pte_ctor(void *addr) 864 { 865 memset(addr, 0, RADIX_PTE_TABLE_SIZE); 866 } 867 868 static void pmd_ctor(void *addr) 869 { 870 memset(addr, 0, RADIX_PMD_TABLE_SIZE); 871 } 872 873 int kvmppc_radix_init(void) 874 { 875 unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE; 876 877 kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor); 878 if (!kvm_pte_cache) 879 return -ENOMEM; 880 881 size = sizeof(void *) << RADIX_PMD_INDEX_SIZE; 882 883 kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor); 884 if (!kvm_pmd_cache) { 885 kmem_cache_destroy(kvm_pte_cache); 886 return -ENOMEM; 887 } 888 889 return 0; 890 } 891 892 void kvmppc_radix_exit(void) 893 { 894 kmem_cache_destroy(kvm_pte_cache); 895 kmem_cache_destroy(kvm_pmd_cache); 896 } 897