arch/arm/kvm/mmu.c

   1 /*
   2  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
   3  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  */
  18
  19 #include <linux/mman.h>
  20 #include <linux/kvm_host.h>
  21 #include <linux/io.h>
  22 #include <linux/hugetlb.h>
  23 #include <trace/events/kvm.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/cacheflush.h>
  26 #include <asm/kvm_arm.h>
  27 #include <asm/kvm_mmu.h>
  28 #include <asm/kvm_mmio.h>
  29 #include <asm/kvm_asm.h>
  30 #include <asm/kvm_emulate.h>
  31 #include <asm/virt.h>
  32
  33 #include "trace.h"
  34
  35 static pgd_t *boot_hyp_pgd;
  36 static pgd_t *hyp_pgd;
  37 static pgd_t *merged_hyp_pgd;
  38 static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
  39
  40 static unsigned long hyp_idmap_start;
  41 static unsigned long hyp_idmap_end;
  42 static phys_addr_t hyp_idmap_vector;
  43
  44 #define S2_PGD_SIZE     (PTRS_PER_S2_PGD * sizeof(pgd_t))
  45 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
  46
  47 #define KVM_S2PTE_FLAG_IS_IOMAP         (1UL << 0)
  48 #define KVM_S2_FLAG_LOGGING_ACTIVE      (1UL << 1)
  49
  50 static bool memslot_is_logging(struct kvm_memory_slot *memslot)
  51 {
  52         return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
  53 }
  54
  55 /**
  56  * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
  57  * @kvm:        pointer to kvm structure.
  58  *
  59  * Interface to HYP function to flush all VM TLB entries
  60  */
  61 void kvm_flush_remote_tlbs(struct kvm *kvm)
  62 {
  63         kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
  64 }
  65
  66 static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
  67 {
  68         kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
  69 }
  70
  71 /*
  72  * D-Cache management functions. They take the page table entries by
  73  * value, as they are flushing the cache using the kernel mapping (or
  74  * kmap on 32bit).
  75  */
  76 static void kvm_flush_dcache_pte(pte_t pte)
  77 {
  78         __kvm_flush_dcache_pte(pte);
  79 }
  80
  81 static void kvm_flush_dcache_pmd(pmd_t pmd)
  82 {
  83         __kvm_flush_dcache_pmd(pmd);
  84 }
  85
  86 static void kvm_flush_dcache_pud(pud_t pud)
  87 {
  88         __kvm_flush_dcache_pud(pud);
  89 }
  90
  91 static bool kvm_is_device_pfn(unsigned long pfn)
  92 {
  93         return !pfn_valid(pfn);
  94 }
  95
  96 /**
  97  * stage2_dissolve_pmd() - clear and flush huge PMD entry
  98  * @kvm:        pointer to kvm structure.
  99  * @addr:       IPA
 100  * @pmd:        pmd pointer for IPA
 101  *
 102  * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
 103  * pages in the range dirty.
 104  */
 105 static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
 106 {
 107         if (!pmd_thp_or_huge(*pmd))
 108                 return;
 109
 110         pmd_clear(pmd);
 111         kvm_tlb_flush_vmid_ipa(kvm, addr);
 112         put_page(virt_to_page(pmd));
 113 }
 114
 115 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
 116                                   int min, int max)
 117 {
 118         void *page;
 119
 120         BUG_ON(max > KVM_NR_MEM_OBJS);
 121         if (cache->nobjs >= min)
 122                 return 0;
 123         while (cache->nobjs < max) {
 124                 page = (void *)__get_free_page(PGALLOC_GFP);
 125                 if (!page)
 126                         return -ENOMEM;
 127                 cache->objects[cache->nobjs++] = page;
 128         }
 129         return 0;
 130 }
 131
 132 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
 133 {
 134         while (mc->nobjs)
 135                 free_page((unsigned long)mc->objects[--mc->nobjs]);
 136 }
 137
 138 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
 139 {
 140         void *p;
 141
 142         BUG_ON(!mc || !mc->nobjs);
 143         p = mc->objects[--mc->nobjs];
 144         return p;
 145 }
 146
 147 static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr)
 148 {
 149         pud_t *pud_table __maybe_unused = stage2_pud_offset(pgd, 0UL);
 150         stage2_pgd_clear(pgd);
 151         kvm_tlb_flush_vmid_ipa(kvm, addr);
 152         stage2_pud_free(pud_table);
 153         put_page(virt_to_page(pgd));
 154 }
 155
 156 static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
 157 {
 158         pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(pud, 0);
 159         VM_BUG_ON(stage2_pud_huge(*pud));
 160         stage2_pud_clear(pud);
 161         kvm_tlb_flush_vmid_ipa(kvm, addr);
 162         stage2_pmd_free(pmd_table);
 163         put_page(virt_to_page(pud));
 164 }
 165
 166 static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
 167 {
 168         pte_t *pte_table = pte_offset_kernel(pmd, 0);
 169         VM_BUG_ON(pmd_thp_or_huge(*pmd));
 170         pmd_clear(pmd);
 171         kvm_tlb_flush_vmid_ipa(kvm, addr);
 172         pte_free_kernel(NULL, pte_table);
 173         put_page(virt_to_page(pmd));
 174 }
 175
 176 /*
 177  * Unmapping vs dcache management:
 178  *
 179  * If a guest maps certain memory pages as uncached, all writes will
 180  * bypass the data cache and go directly to RAM.  However, the CPUs
 181  * can still speculate reads (not writes) and fill cache lines with
 182  * data.
 183  *
 184  * Those cache lines will be *clean* cache lines though, so a
 185  * clean+invalidate operation is equivalent to an invalidate
 186  * operation, because no cache lines are marked dirty.
 187  *
 188  * Those clean cache lines could be filled prior to an uncached write
 189  * by the guest, and the cache coherent IO subsystem would therefore
 190  * end up writing old data to disk.
 191  *
 192  * This is why right after unmapping a page/section and invalidating
 193  * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
 194  * the IO subsystem will never hit in the cache.
 195  */
 196 static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd,
 197                        phys_addr_t addr, phys_addr_t end)
 198 {
 199         phys_addr_t start_addr = addr;
 200         pte_t *pte, *start_pte;
 201
 202         start_pte = pte = pte_offset_kernel(pmd, addr);
 203         do {
 204                 if (!pte_none(*pte)) {
 205                         pte_t old_pte = *pte;
 206
 207                         kvm_set_pte(pte, __pte(0));
 208                         kvm_tlb_flush_vmid_ipa(kvm, addr);
 209
 210                         /* No need to invalidate the cache for device mappings */
 211                         if (!kvm_is_device_pfn(pte_pfn(old_pte)))
 212                                 kvm_flush_dcache_pte(old_pte);
 213
 214                         put_page(virt_to_page(pte));
 215                 }
 216         } while (pte++, addr += PAGE_SIZE, addr != end);
 217
 218         if (stage2_pte_table_empty(start_pte))
 219                 clear_stage2_pmd_entry(kvm, pmd, start_addr);
 220 }
 221
 222 static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud,
 223                        phys_addr_t addr, phys_addr_t end)
 224 {
 225         phys_addr_t next, start_addr = addr;
 226         pmd_t *pmd, *start_pmd;
 227
 228         start_pmd = pmd = stage2_pmd_offset(pud, addr);
 229         do {
 230                 next = stage2_pmd_addr_end(addr, end);
 231                 if (!pmd_none(*pmd)) {
 232                         if (pmd_thp_or_huge(*pmd)) {
 233                                 pmd_t old_pmd = *pmd;
 234
 235                                 pmd_clear(pmd);
 236                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 237
 238                                 kvm_flush_dcache_pmd(old_pmd);
 239
 240                                 put_page(virt_to_page(pmd));
 241                         } else {
 242                                 unmap_stage2_ptes(kvm, pmd, addr, next);
 243                         }
 244                 }
 245         } while (pmd++, addr = next, addr != end);
 246
 247         if (stage2_pmd_table_empty(start_pmd))
 248                 clear_stage2_pud_entry(kvm, pud, start_addr);
 249 }
 250
 251 static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd,
 252                        phys_addr_t addr, phys_addr_t end)
 253 {
 254         phys_addr_t next, start_addr = addr;
 255         pud_t *pud, *start_pud;
 256
 257         start_pud = pud = stage2_pud_offset(pgd, addr);
 258         do {
 259                 next = stage2_pud_addr_end(addr, end);
 260                 if (!stage2_pud_none(*pud)) {
 261                         if (stage2_pud_huge(*pud)) {
 262                                 pud_t old_pud = *pud;
 263
 264                                 stage2_pud_clear(pud);
 265                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 266                                 kvm_flush_dcache_pud(old_pud);
 267                                 put_page(virt_to_page(pud));
 268                         } else {
 269                                 unmap_stage2_pmds(kvm, pud, addr, next);
 270                         }
 271                 }
 272         } while (pud++, addr = next, addr != end);
 273
 274         if (stage2_pud_table_empty(start_pud))
 275                 clear_stage2_pgd_entry(kvm, pgd, start_addr);
 276 }
 277
 278 /**
 279  * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
 280  * @kvm:   The VM pointer
 281  * @start: The intermediate physical base address of the range to unmap
 282  * @size:  The size of the area to unmap
 283  *
 284  * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
 285  * be called while holding mmu_lock (unless for freeing the stage2 pgd before
 286  * destroying the VM), otherwise another faulting VCPU may come in and mess
 287  * with things behind our backs.
 288  */
 289 static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
 290 {
 291         pgd_t *pgd;
 292         phys_addr_t addr = start, end = start + size;
 293         phys_addr_t next;
 294
 295         assert_spin_locked(&kvm->mmu_lock);
 296         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
 297         do {
 298                 next = stage2_pgd_addr_end(addr, end);
 299                 if (!stage2_pgd_none(*pgd))
 300                         unmap_stage2_puds(kvm, pgd, addr, next);
 301                 /*
 302                  * If the range is too large, release the kvm->mmu_lock
 303                  * to prevent starvation and lockup detector warnings.
 304                  */
 305                 if (next != end)
 306                         cond_resched_lock(&kvm->mmu_lock);
 307         } while (pgd++, addr = next, addr != end);
 308 }
 309
 310 static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
 311                               phys_addr_t addr, phys_addr_t end)
 312 {
 313         pte_t *pte;
 314
 315         pte = pte_offset_kernel(pmd, addr);
 316         do {
 317                 if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte)))
 318                         kvm_flush_dcache_pte(*pte);
 319         } while (pte++, addr += PAGE_SIZE, addr != end);
 320 }
 321
 322 static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
 323                               phys_addr_t addr, phys_addr_t end)
 324 {
 325         pmd_t *pmd;
 326         phys_addr_t next;
 327
 328         pmd = stage2_pmd_offset(pud, addr);
 329         do {
 330                 next = stage2_pmd_addr_end(addr, end);
 331                 if (!pmd_none(*pmd)) {
 332                         if (pmd_thp_or_huge(*pmd))
 333                                 kvm_flush_dcache_pmd(*pmd);
 334                         else
 335                                 stage2_flush_ptes(kvm, pmd, addr, next);
 336                 }
 337         } while (pmd++, addr = next, addr != end);
 338 }
 339
 340 static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd,
 341                               phys_addr_t addr, phys_addr_t end)
 342 {
 343         pud_t *pud;
 344         phys_addr_t next;
 345
 346         pud = stage2_pud_offset(pgd, addr);
 347         do {
 348                 next = stage2_pud_addr_end(addr, end);
 349                 if (!stage2_pud_none(*pud)) {
 350                         if (stage2_pud_huge(*pud))
 351                                 kvm_flush_dcache_pud(*pud);
 352                         else
 353                                 stage2_flush_pmds(kvm, pud, addr, next);
 354                 }
 355         } while (pud++, addr = next, addr != end);
 356 }
 357
 358 static void stage2_flush_memslot(struct kvm *kvm,
 359                                  struct kvm_memory_slot *memslot)
 360 {
 361         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
 362         phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
 363         phys_addr_t next;
 364         pgd_t *pgd;
 365
 366         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
 367         do {
 368                 next = stage2_pgd_addr_end(addr, end);
 369                 stage2_flush_puds(kvm, pgd, addr, next);
 370         } while (pgd++, addr = next, addr != end);
 371 }
 372
 373 /**
 374  * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
 375  * @kvm: The struct kvm pointer
 376  *
 377  * Go through the stage 2 page tables and invalidate any cache lines
 378  * backing memory already mapped to the VM.
 379  */
 380 static void stage2_flush_vm(struct kvm *kvm)
 381 {
 382         struct kvm_memslots *slots;
 383         struct kvm_memory_slot *memslot;
 384         int idx;
 385
 386         idx = srcu_read_lock(&kvm->srcu);
 387         spin_lock(&kvm->mmu_lock);
 388
 389         slots = kvm_memslots(kvm);
 390         kvm_for_each_memslot(memslot, slots)
 391                 stage2_flush_memslot(kvm, memslot);
 392
 393         spin_unlock(&kvm->mmu_lock);
 394         srcu_read_unlock(&kvm->srcu, idx);
 395 }
 396
 397 static void clear_hyp_pgd_entry(pgd_t *pgd)
 398 {
 399         pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL);
 400         pgd_clear(pgd);
 401         pud_free(NULL, pud_table);
 402         put_page(virt_to_page(pgd));
 403 }
 404
 405 static void clear_hyp_pud_entry(pud_t *pud)
 406 {
 407         pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0);
 408         VM_BUG_ON(pud_huge(*pud));
 409         pud_clear(pud);
 410         pmd_free(NULL, pmd_table);
 411         put_page(virt_to_page(pud));
 412 }
 413
 414 static void clear_hyp_pmd_entry(pmd_t *pmd)
 415 {
 416         pte_t *pte_table = pte_offset_kernel(pmd, 0);
 417         VM_BUG_ON(pmd_thp_or_huge(*pmd));
 418         pmd_clear(pmd);
 419         pte_free_kernel(NULL, pte_table);
 420         put_page(virt_to_page(pmd));
 421 }
 422
 423 static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
 424 {
 425         pte_t *pte, *start_pte;
 426
 427         start_pte = pte = pte_offset_kernel(pmd, addr);
 428         do {
 429                 if (!pte_none(*pte)) {
 430                         kvm_set_pte(pte, __pte(0));
 431                         put_page(virt_to_page(pte));
 432                 }
 433         } while (pte++, addr += PAGE_SIZE, addr != end);
 434
 435         if (hyp_pte_table_empty(start_pte))
 436                 clear_hyp_pmd_entry(pmd);
 437 }
 438
 439 static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
 440 {
 441         phys_addr_t next;
 442         pmd_t *pmd, *start_pmd;
 443
 444         start_pmd = pmd = pmd_offset(pud, addr);
 445         do {
 446                 next = pmd_addr_end(addr, end);
 447                 /* Hyp doesn't use huge pmds */
 448                 if (!pmd_none(*pmd))
 449                         unmap_hyp_ptes(pmd, addr, next);
 450         } while (pmd++, addr = next, addr != end);
 451
 452         if (hyp_pmd_table_empty(start_pmd))
 453                 clear_hyp_pud_entry(pud);
 454 }
 455
 456 static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
 457 {
 458         phys_addr_t next;
 459         pud_t *pud, *start_pud;
 460
 461         start_pud = pud = pud_offset(pgd, addr);
 462         do {
 463                 next = pud_addr_end(addr, end);
 464                 /* Hyp doesn't use huge puds */
 465                 if (!pud_none(*pud))
 466                         unmap_hyp_pmds(pud, addr, next);
 467         } while (pud++, addr = next, addr != end);
 468
 469         if (hyp_pud_table_empty(start_pud))
 470                 clear_hyp_pgd_entry(pgd);
 471 }
 472
 473 static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size)
 474 {
 475         pgd_t *pgd;
 476         phys_addr_t addr = start, end = start + size;
 477         phys_addr_t next;
 478
 479         /*
 480          * We don't unmap anything from HYP, except at the hyp tear down.
 481          * Hence, we don't have to invalidate the TLBs here.
 482          */
 483         pgd = pgdp + pgd_index(addr);
 484         do {
 485                 next = pgd_addr_end(addr, end);
 486                 if (!pgd_none(*pgd))
 487                         unmap_hyp_puds(pgd, addr, next);
 488         } while (pgd++, addr = next, addr != end);
 489 }
 490
 491 /**
 492  * free_hyp_pgds - free Hyp-mode page tables
 493  *
 494  * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
 495  * therefore contains either mappings in the kernel memory area (above
 496  * PAGE_OFFSET), or device mappings in the vmalloc range (from
 497  * VMALLOC_START to VMALLOC_END).
 498  *
 499  * boot_hyp_pgd should only map two pages for the init code.
 500  */
 501 void free_hyp_pgds(void)
 502 {
 503         unsigned long addr;
 504
 505         mutex_lock(&kvm_hyp_pgd_mutex);
 506
 507         if (boot_hyp_pgd) {
 508                 unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
 509                 free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
 510                 boot_hyp_pgd = NULL;
 511         }
 512
 513         if (hyp_pgd) {
 514                 unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE);
 515                 for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
 516                         unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
 517                 for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
 518                         unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
 519
 520                 free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
 521                 hyp_pgd = NULL;
 522         }
 523         if (merged_hyp_pgd) {
 524                 clear_page(merged_hyp_pgd);
 525                 free_page((unsigned long)merged_hyp_pgd);
 526                 merged_hyp_pgd = NULL;
 527         }
 528
 529         mutex_unlock(&kvm_hyp_pgd_mutex);
 530 }
 531
 532 static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
 533                                     unsigned long end, unsigned long pfn,
 534                                     pgprot_t prot)
 535 {
 536         pte_t *pte;
 537         unsigned long addr;
 538
 539         addr = start;
 540         do {
 541                 pte = pte_offset_kernel(pmd, addr);
 542                 kvm_set_pte(pte, pfn_pte(pfn, prot));
 543                 get_page(virt_to_page(pte));
 544                 kvm_flush_dcache_to_poc(pte, sizeof(*pte));
 545                 pfn++;
 546         } while (addr += PAGE_SIZE, addr != end);
 547 }
 548
 549 static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
 550                                    unsigned long end, unsigned long pfn,
 551                                    pgprot_t prot)
 552 {
 553         pmd_t *pmd;
 554         pte_t *pte;
 555         unsigned long addr, next;
 556
 557         addr = start;
 558         do {
 559                 pmd = pmd_offset(pud, addr);
 560
 561                 BUG_ON(pmd_sect(*pmd));
 562
 563                 if (pmd_none(*pmd)) {
 564                         pte = pte_alloc_one_kernel(NULL, addr);
 565                         if (!pte) {
 566                                 kvm_err("Cannot allocate Hyp pte\n");
 567                                 return -ENOMEM;
 568                         }
 569                         pmd_populate_kernel(NULL, pmd, pte);
 570                         get_page(virt_to_page(pmd));
 571                         kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
 572                 }
 573
 574                 next = pmd_addr_end(addr, end);
 575
 576                 create_hyp_pte_mappings(pmd, addr, next, pfn, prot);
 577                 pfn += (next - addr) >> PAGE_SHIFT;
 578         } while (addr = next, addr != end);
 579
 580         return 0;
 581 }
 582
 583 static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
 584                                    unsigned long end, unsigned long pfn,
 585                                    pgprot_t prot)
 586 {
 587         pud_t *pud;
 588         pmd_t *pmd;
 589         unsigned long addr, next;
 590         int ret;
 591
 592         addr = start;
 593         do {
 594                 pud = pud_offset(pgd, addr);
 595
 596                 if (pud_none_or_clear_bad(pud)) {
 597                         pmd = pmd_alloc_one(NULL, addr);
 598                         if (!pmd) {
 599                                 kvm_err("Cannot allocate Hyp pmd\n");
 600                                 return -ENOMEM;
 601                         }
 602                         pud_populate(NULL, pud, pmd);
 603                         get_page(virt_to_page(pud));
 604                         kvm_flush_dcache_to_poc(pud, sizeof(*pud));
 605                 }
 606
 607                 next = pud_addr_end(addr, end);
 608                 ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
 609                 if (ret)
 610                         return ret;
 611                 pfn += (next - addr) >> PAGE_SHIFT;
 612         } while (addr = next, addr != end);
 613
 614         return 0;
 615 }
 616
 617 static int __create_hyp_mappings(pgd_t *pgdp,
 618                                  unsigned long start, unsigned long end,
 619                                  unsigned long pfn, pgprot_t prot)
 620 {
 621         pgd_t *pgd;
 622         pud_t *pud;
 623         unsigned long addr, next;
 624         int err = 0;
 625
 626         mutex_lock(&kvm_hyp_pgd_mutex);
 627         addr = start & PAGE_MASK;
 628         end = PAGE_ALIGN(end);
 629         do {
 630                 pgd = pgdp + pgd_index(addr);
 631
 632                 if (pgd_none(*pgd)) {
 633                         pud = pud_alloc_one(NULL, addr);
 634                         if (!pud) {
 635                                 kvm_err("Cannot allocate Hyp pud\n");
 636                                 err = -ENOMEM;
 637                                 goto out;
 638                         }
 639                         pgd_populate(NULL, pgd, pud);
 640                         get_page(virt_to_page(pgd));
 641                         kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
 642                 }
 643
 644                 next = pgd_addr_end(addr, end);
 645                 err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
 646                 if (err)
 647                         goto out;
 648                 pfn += (next - addr) >> PAGE_SHIFT;
 649         } while (addr = next, addr != end);
 650 out:
 651         mutex_unlock(&kvm_hyp_pgd_mutex);
 652         return err;
 653 }
 654
 655 static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
 656 {
 657         if (!is_vmalloc_addr(kaddr)) {
 658                 BUG_ON(!virt_addr_valid(kaddr));
 659                 return __pa(kaddr);
 660         } else {
 661                 return page_to_phys(vmalloc_to_page(kaddr)) +
 662                        offset_in_page(kaddr);
 663         }
 664 }
 665
 666 /**
 667  * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
 668  * @from:       The virtual kernel start address of the range
 669  * @to:         The virtual kernel end address of the range (exclusive)
 670  * @prot:       The protection to be applied to this range
 671  *
 672  * The same virtual address as the kernel virtual address is also used
 673  * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
 674  * physical pages.
 675  */
 676 int create_hyp_mappings(void *from, void *to, pgprot_t prot)
 677 {
 678         phys_addr_t phys_addr;
 679         unsigned long virt_addr;
 680         unsigned long start = kern_hyp_va((unsigned long)from);
 681         unsigned long end = kern_hyp_va((unsigned long)to);
 682
 683         if (is_kernel_in_hyp_mode())
 684                 return 0;
 685
 686         start = start & PAGE_MASK;
 687         end = PAGE_ALIGN(end);
 688
 689         for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
 690                 int err;
 691
 692                 phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
 693                 err = __create_hyp_mappings(hyp_pgd, virt_addr,
 694                                             virt_addr + PAGE_SIZE,
 695                                             __phys_to_pfn(phys_addr),
 696                                             prot);
 697                 if (err)
 698                         return err;
 699         }
 700
 701         return 0;
 702 }
 703
 704 /**
 705  * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
 706  * @from:       The kernel start VA of the range
 707  * @to:         The kernel end VA of the range (exclusive)
 708  * @phys_addr:  The physical start address which gets mapped
 709  *
 710  * The resulting HYP VA is the same as the kernel VA, modulo
 711  * HYP_PAGE_OFFSET.
 712  */
 713 int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
 714 {
 715         unsigned long start = kern_hyp_va((unsigned long)from);
 716         unsigned long end = kern_hyp_va((unsigned long)to);
 717
 718         if (is_kernel_in_hyp_mode())
 719                 return 0;
 720
 721         /* Check for a valid kernel IO mapping */
 722         if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
 723                 return -EINVAL;
 724
 725         return __create_hyp_mappings(hyp_pgd, start, end,
 726                                      __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
 727 }
 728
 729 /**
 730  * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
 731  * @kvm:        The KVM struct pointer for the VM.
 732  *
 733  * Allocates only the stage-2 HW PGD level table(s) (can support either full
 734  * 40-bit input addresses or limited to 32-bit input addresses). Clears the
 735  * allocated pages.
 736  *
 737  * Note we don't need locking here as this is only called when the VM is
 738  * created, which can only be done once.
 739  */
 740 int kvm_alloc_stage2_pgd(struct kvm *kvm)
 741 {
 742         pgd_t *pgd;
 743
 744         if (kvm->arch.pgd != NULL) {
 745                 kvm_err("kvm_arch already initialized?\n");
 746                 return -EINVAL;
 747         }
 748
 749         /* Allocate the HW PGD, making sure that each page gets its own refcount */
 750         pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO);
 751         if (!pgd)
 752                 return -ENOMEM;
 753
 754         kvm->arch.pgd = pgd;
 755         return 0;
 756 }
 757
 758 static void stage2_unmap_memslot(struct kvm *kvm,
 759                                  struct kvm_memory_slot *memslot)
 760 {
 761         hva_t hva = memslot->userspace_addr;
 762         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
 763         phys_addr_t size = PAGE_SIZE * memslot->npages;
 764         hva_t reg_end = hva + size;
 765
 766         /*
 767          * A memory region could potentially cover multiple VMAs, and any holes
 768          * between them, so iterate over all of them to find out if we should
 769          * unmap any of them.
 770          *
 771          *     +--------------------------------------------+
 772          * +---------------+----------------+   +----------------+
 773          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
 774          * +---------------+----------------+   +----------------+
 775          *     |               memory region                |
 776          *     +--------------------------------------------+
 777          */
 778         do {
 779                 struct vm_area_struct *vma = find_vma(current->mm, hva);
 780                 hva_t vm_start, vm_end;
 781
 782                 if (!vma || vma->vm_start >= reg_end)
 783                         break;
 784
 785                 /*
 786                  * Take the intersection of this VMA with the memory region
 787                  */
 788                 vm_start = max(hva, vma->vm_start);
 789                 vm_end = min(reg_end, vma->vm_end);
 790
 791                 if (!(vma->vm_flags & VM_PFNMAP)) {
 792                         gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
 793                         unmap_stage2_range(kvm, gpa, vm_end - vm_start);
 794                 }
 795                 hva = vm_end;
 796         } while (hva < reg_end);
 797 }
 798
 799 /**
 800  * stage2_unmap_vm - Unmap Stage-2 RAM mappings
 801  * @kvm: The struct kvm pointer
 802  *
 803  * Go through the memregions and unmap any reguler RAM
 804  * backing memory already mapped to the VM.
 805  */
 806 void stage2_unmap_vm(struct kvm *kvm)
 807 {
 808         struct kvm_memslots *slots;
 809         struct kvm_memory_slot *memslot;
 810         int idx;
 811
 812         idx = srcu_read_lock(&kvm->srcu);
 813         down_read(&current->mm->mmap_sem);
 814         spin_lock(&kvm->mmu_lock);
 815
 816         slots = kvm_memslots(kvm);
 817         kvm_for_each_memslot(memslot, slots)
 818                 stage2_unmap_memslot(kvm, memslot);
 819
 820         spin_unlock(&kvm->mmu_lock);
 821         up_read(&current->mm->mmap_sem);
 822         srcu_read_unlock(&kvm->srcu, idx);
 823 }
 824
 825 /**
 826  * kvm_free_stage2_pgd - free all stage-2 tables
 827  * @kvm:        The KVM struct pointer for the VM.
 828  *
 829  * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
 830  * underlying level-2 and level-3 tables before freeing the actual level-1 table
 831  * and setting the struct pointer to NULL.
 832  *
 833  * Note we don't need locking here as this is only called when the VM is
 834  * destroyed, which can only be done once.
 835  */
 836 void kvm_free_stage2_pgd(struct kvm *kvm)
 837 {
 838         if (kvm->arch.pgd == NULL)
 839                 return;
 840
 841         spin_lock(&kvm->mmu_lock);
 842         unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
 843         spin_unlock(&kvm->mmu_lock);
 844
 845         /* Free the HW pgd, one page at a time */
 846         free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE);
 847         kvm->arch.pgd = NULL;
 848 }
 849
 850 static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 851                              phys_addr_t addr)
 852 {
 853         pgd_t *pgd;
 854         pud_t *pud;
 855
 856         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
 857         if (WARN_ON(stage2_pgd_none(*pgd))) {
 858                 if (!cache)
 859                         return NULL;
 860                 pud = mmu_memory_cache_alloc(cache);
 861                 stage2_pgd_populate(pgd, pud);
 862                 get_page(virt_to_page(pgd));
 863         }
 864
 865         return stage2_pud_offset(pgd, addr);
 866 }
 867
 868 static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 869                              phys_addr_t addr)
 870 {
 871         pud_t *pud;
 872         pmd_t *pmd;
 873
 874         pud = stage2_get_pud(kvm, cache, addr);
 875         if (stage2_pud_none(*pud)) {
 876                 if (!cache)
 877                         return NULL;
 878                 pmd = mmu_memory_cache_alloc(cache);
 879                 stage2_pud_populate(pud, pmd);
 880                 get_page(virt_to_page(pud));
 881         }
 882
 883         return stage2_pmd_offset(pud, addr);
 884 }
 885
 886 static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
 887                                *cache, phys_addr_t addr, const pmd_t *new_pmd)
 888 {
 889         pmd_t *pmd, old_pmd;
 890
 891         pmd = stage2_get_pmd(kvm, cache, addr);
 892         VM_BUG_ON(!pmd);
 893
 894         /*
 895          * Mapping in huge pages should only happen through a fault.  If a
 896          * page is merged into a transparent huge page, the individual
 897          * subpages of that huge page should be unmapped through MMU
 898          * notifiers before we get here.
 899          *
 900          * Merging of CompoundPages is not supported; they should become
 901          * splitting first, unmapped, merged, and mapped back in on-demand.
 902          */
 903         VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd));
 904
 905         old_pmd = *pmd;
 906         if (pmd_present(old_pmd)) {
 907                 pmd_clear(pmd);
 908                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 909         } else {
 910                 get_page(virt_to_page(pmd));
 911         }
 912
 913         kvm_set_pmd(pmd, *new_pmd);
 914         return 0;
 915 }
 916
 917 static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 918                           phys_addr_t addr, const pte_t *new_pte,
 919                           unsigned long flags)
 920 {
 921         pmd_t *pmd;
 922         pte_t *pte, old_pte;
 923         bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
 924         bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;
 925
 926         VM_BUG_ON(logging_active && !cache);
 927
 928         /* Create stage-2 page table mapping - Levels 0 and 1 */
 929         pmd = stage2_get_pmd(kvm, cache, addr);
 930         if (!pmd) {
 931                 /*
 932                  * Ignore calls from kvm_set_spte_hva for unallocated
 933                  * address ranges.
 934                  */
 935                 return 0;
 936         }
 937
 938         /*
 939          * While dirty page logging - dissolve huge PMD, then continue on to
 940          * allocate page.
 941          */
 942         if (logging_active)
 943                 stage2_dissolve_pmd(kvm, addr, pmd);
 944
 945         /* Create stage-2 page mappings - Level 2 */
 946         if (pmd_none(*pmd)) {
 947                 if (!cache)
 948                         return 0; /* ignore calls from kvm_set_spte_hva */
 949                 pte = mmu_memory_cache_alloc(cache);
 950                 pmd_populate_kernel(NULL, pmd, pte);
 951                 get_page(virt_to_page(pmd));
 952         }
 953
 954         pte = pte_offset_kernel(pmd, addr);
 955
 956         if (iomap && pte_present(*pte))
 957                 return -EFAULT;
 958
 959         /* Create 2nd stage page table mapping - Level 3 */
 960         old_pte = *pte;
 961         if (pte_present(old_pte)) {
 962                 kvm_set_pte(pte, __pte(0));
 963                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 964         } else {
 965                 get_page(virt_to_page(pte));
 966         }
 967
 968         kvm_set_pte(pte, *new_pte);
 969         return 0;
 970 }
 971
 972 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 973 static int stage2_ptep_test_and_clear_young(pte_t *pte)
 974 {
 975         if (pte_young(*pte)) {
 976                 *pte = pte_mkold(*pte);
 977                 return 1;
 978         }
 979         return 0;
 980 }
 981 #else
 982 static int stage2_ptep_test_and_clear_young(pte_t *pte)
 983 {
 984         return __ptep_test_and_clear_young(pte);
 985 }
 986 #endif
 987
 988 static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
 989 {
 990         return stage2_ptep_test_and_clear_young((pte_t *)pmd);
 991 }
 992
 993 /**
 994  * kvm_phys_addr_ioremap - map a device range to guest IPA
 995  *
 996  * @kvm:        The KVM pointer
 997  * @guest_ipa:  The IPA at which to insert the mapping
 998  * @pa:         The physical address of the device
 999  * @size:       The size of the mapping
1000  */
1001 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
1002                           phys_addr_t pa, unsigned long size, bool writable)
1003 {
1004         phys_addr_t addr, end;
1005         int ret = 0;
1006         unsigned long pfn;
1007         struct kvm_mmu_memory_cache cache = { 0, };
1008
1009         end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
1010         pfn = __phys_to_pfn(pa);
1011
1012         for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
1013                 pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
1014
1015                 if (writable)
1016                         pte = kvm_s2pte_mkwrite(pte);
1017
1018                 ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
1019                                                 KVM_NR_MEM_OBJS);
1020                 if (ret)
1021                         goto out;
1022                 spin_lock(&kvm->mmu_lock);
1023                 ret = stage2_set_pte(kvm, &cache, addr, &pte,
1024                                                 KVM_S2PTE_FLAG_IS_IOMAP);
1025                 spin_unlock(&kvm->mmu_lock);
1026                 if (ret)
1027                         goto out;
1028
1029                 pfn++;
1030         }
1031
1032 out:
1033         mmu_free_memory_cache(&cache);
1034         return ret;
1035 }
1036
1037 static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
1038 {
1039         kvm_pfn_t pfn = *pfnp;
1040         gfn_t gfn = *ipap >> PAGE_SHIFT;
1041
1042         if (PageTransCompoundMap(pfn_to_page(pfn))) {
1043                 unsigned long mask;
1044                 /*
1045                  * The address we faulted on is backed by a transparent huge
1046                  * page.  However, because we map the compound huge page and
1047                  * not the individual tail page, we need to transfer the
1048                  * refcount to the head page.  We have to be careful that the
1049                  * THP doesn't start to split while we are adjusting the
1050                  * refcounts.
1051                  *
1052                  * We are sure this doesn't happen, because mmu_notifier_retry
1053                  * was successful and we are holding the mmu_lock, so if this
1054                  * THP is trying to split, it will be blocked in the mmu
1055                  * notifier before touching any of the pages, specifically
1056                  * before being able to call __split_huge_page_refcount().
1057                  *
1058                  * We can therefore safely transfer the refcount from PG_tail
1059                  * to PG_head and switch the pfn from a tail page to the head
1060                  * page accordingly.
1061                  */
1062                 mask = PTRS_PER_PMD - 1;
1063                 VM_BUG_ON((gfn & mask) != (pfn & mask));
1064                 if (pfn & mask) {
1065                         *ipap &= PMD_MASK;
1066                         kvm_release_pfn_clean(pfn);
1067                         pfn &= ~mask;
1068                         kvm_get_pfn(pfn);
1069                         *pfnp = pfn;
1070                 }
1071
1072                 return true;
1073         }
1074
1075         return false;
1076 }
1077
1078 static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
1079 {
1080         if (kvm_vcpu_trap_is_iabt(vcpu))
1081                 return false;
1082
1083         return kvm_vcpu_dabt_iswrite(vcpu);
1084 }
1085
1086 /**
1087  * stage2_wp_ptes - write protect PMD range
1088  * @pmd:        pointer to pmd entry
1089  * @addr:       range start address
1090  * @end:        range end address
1091  */
1092 static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
1093 {
1094         pte_t *pte;
1095
1096         pte = pte_offset_kernel(pmd, addr);
1097         do {
1098                 if (!pte_none(*pte)) {
1099                         if (!kvm_s2pte_readonly(pte))
1100                                 kvm_set_s2pte_readonly(pte);
1101                 }
1102         } while (pte++, addr += PAGE_SIZE, addr != end);
1103 }
1104
1105 /**
1106  * stage2_wp_pmds - write protect PUD range
1107  * @pud:        pointer to pud entry
1108  * @addr:       range start address
1109  * @end:        range end address
1110  */
1111 static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
1112 {
1113         pmd_t *pmd;
1114         phys_addr_t next;
1115
1116         pmd = stage2_pmd_offset(pud, addr);
1117
1118         do {
1119                 next = stage2_pmd_addr_end(addr, end);
1120                 if (!pmd_none(*pmd)) {
1121                         if (pmd_thp_or_huge(*pmd)) {
1122                                 if (!kvm_s2pmd_readonly(pmd))
1123                                         kvm_set_s2pmd_readonly(pmd);
1124                         } else {
1125                                 stage2_wp_ptes(pmd, addr, next);
1126                         }
1127                 }
1128         } while (pmd++, addr = next, addr != end);
1129 }
1130
1131 /**
1132   * stage2_wp_puds - write protect PGD range
1133   * @pgd:       pointer to pgd entry
1134   * @addr:      range start address
1135   * @end:       range end address
1136   *
1137   * Process PUD entries, for a huge PUD we cause a panic.
1138   */
1139 static void  stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
1140 {
1141         pud_t *pud;
1142         phys_addr_t next;
1143
1144         pud = stage2_pud_offset(pgd, addr);
1145         do {
1146                 next = stage2_pud_addr_end(addr, end);
1147                 if (!stage2_pud_none(*pud)) {
1148                         /* TODO:PUD not supported, revisit later if supported */
1149                         BUG_ON(stage2_pud_huge(*pud));
1150                         stage2_wp_pmds(pud, addr, next);
1151                 }
1152         } while (pud++, addr = next, addr != end);
1153 }
1154
1155 /**
1156  * stage2_wp_range() - write protect stage2 memory region range
1157  * @kvm:        The KVM pointer
1158  * @addr:       Start address of range
1159  * @end:        End address of range
1160  */
1161 static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
1162 {
1163         pgd_t *pgd;
1164         phys_addr_t next;
1165
1166         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
1167         do {
1168                 /*
1169                  * Release kvm_mmu_lock periodically if the memory region is
1170                  * large. Otherwise, we may see kernel panics with
1171                  * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
1172                  * CONFIG_LOCKDEP. Additionally, holding the lock too long
1173                  * will also starve other vCPUs.
1174                  */
1175                 if (need_resched() || spin_needbreak(&kvm->mmu_lock))
1176                         cond_resched_lock(&kvm->mmu_lock);
1177
1178                 next = stage2_pgd_addr_end(addr, end);
1179                 if (stage2_pgd_present(*pgd))
1180                         stage2_wp_puds(pgd, addr, next);
1181         } while (pgd++, addr = next, addr != end);
1182 }
1183
1184 /**
1185  * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1186  * @kvm:        The KVM pointer
1187  * @slot:       The memory slot to write protect
1188  *
1189  * Called to start logging dirty pages after memory region
1190  * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1191  * all present PMD and PTEs are write protected in the memory region.
1192  * Afterwards read of dirty page log can be called.
1193  *
1194  * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1195  * serializing operations for VM memory regions.
1196  */
1197 void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
1198 {
1199         struct kvm_memslots *slots = kvm_memslots(kvm);
1200         struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1201         phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
1202         phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
1203
1204         spin_lock(&kvm->mmu_lock);
1205         stage2_wp_range(kvm, start, end);
1206         spin_unlock(&kvm->mmu_lock);
1207         kvm_flush_remote_tlbs(kvm);
1208 }
1209
1210 /**
1211  * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1212  * @kvm:        The KVM pointer
1213  * @slot:       The memory slot associated with mask
1214  * @gfn_offset: The gfn offset in memory slot
1215  * @mask:       The mask of dirty pages at offset 'gfn_offset' in this memory
1216  *              slot to be write protected
1217  *
1218  * Walks bits set in mask write protects the associated pte's. Caller must
1219  * acquire kvm_mmu_lock.
1220  */
1221 static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
1222                 struct kvm_memory_slot *slot,
1223                 gfn_t gfn_offset, unsigned long mask)
1224 {
1225         phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
1226         phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
1227         phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
1228
1229         stage2_wp_range(kvm, start, end);
1230 }
1231
1232 /*
1233  * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
1234  * dirty pages.
1235  *
1236  * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
1237  * enable dirty logging for them.
1238  */
1239 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
1240                 struct kvm_memory_slot *slot,
1241                 gfn_t gfn_offset, unsigned long mask)
1242 {
1243         kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
1244 }
1245
1246 static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
1247                                       unsigned long size)
1248 {
1249         __coherent_cache_guest_page(vcpu, pfn, size);
1250 }
1251
1252 static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1253                           struct kvm_memory_slot *memslot, unsigned long hva,
1254                           unsigned long fault_status)
1255 {
1256         int ret;
1257         bool write_fault, writable, hugetlb = false, force_pte = false;
1258         unsigned long mmu_seq;
1259         gfn_t gfn = fault_ipa >> PAGE_SHIFT;
1260         struct kvm *kvm = vcpu->kvm;
1261         struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1262         struct vm_area_struct *vma;
1263         kvm_pfn_t pfn;
1264         pgprot_t mem_type = PAGE_S2;
1265         bool logging_active = memslot_is_logging(memslot);
1266         unsigned long flags = 0;
1267
1268         write_fault = kvm_is_write_fault(vcpu);
1269         if (fault_status == FSC_PERM && !write_fault) {
1270                 kvm_err("Unexpected L2 read permission error\n");
1271                 return -EFAULT;
1272         }
1273
1274         /* Let's check if we will get back a huge page backed by hugetlbfs */
1275         down_read(&current->mm->mmap_sem);
1276         vma = find_vma_intersection(current->mm, hva, hva + 1);
1277         if (unlikely(!vma)) {
1278                 kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
1279                 up_read(&current->mm->mmap_sem);
1280                 return -EFAULT;
1281         }
1282
1283         if (is_vm_hugetlb_page(vma) && !logging_active) {
1284                 hugetlb = true;
1285                 gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
1286         } else {
1287                 /*
1288                  * Pages belonging to memslots that don't have the same
1289                  * alignment for userspace and IPA cannot be mapped using
1290                  * block descriptors even if the pages belong to a THP for
1291                  * the process, because the stage-2 block descriptor will
1292                  * cover more than a single THP and we loose atomicity for
1293                  * unmapping, updates, and splits of the THP or other pages
1294                  * in the stage-2 block range.
1295                  */
1296                 if ((memslot->userspace_addr & ~PMD_MASK) !=
1297                     ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
1298                         force_pte = true;
1299         }
1300         up_read(&current->mm->mmap_sem);
1301
1302         /* We need minimum second+third level pages */
1303         ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
1304                                      KVM_NR_MEM_OBJS);
1305         if (ret)
1306                 return ret;
1307
1308         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1309         /*
1310          * Ensure the read of mmu_notifier_seq happens before we call
1311          * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1312          * the page we just got a reference to gets unmapped before we have a
1313          * chance to grab the mmu_lock, which ensure that if the page gets
1314          * unmapped afterwards, the call to kvm_unmap_hva will take it away
1315          * from us again properly. This smp_rmb() interacts with the smp_wmb()
1316          * in kvm_mmu_notifier_invalidate_<page|range_end>.
1317          */
1318         smp_rmb();
1319
1320         pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
1321         if (is_error_noslot_pfn(pfn))
1322                 return -EFAULT;
1323
1324         if (kvm_is_device_pfn(pfn)) {
1325                 mem_type = PAGE_S2_DEVICE;
1326                 flags |= KVM_S2PTE_FLAG_IS_IOMAP;
1327         } else if (logging_active) {
1328                 /*
1329                  * Faults on pages in a memslot with logging enabled
1330                  * should not be mapped with huge pages (it introduces churn
1331                  * and performance degradation), so force a pte mapping.
1332                  */
1333                 force_pte = true;
1334                 flags |= KVM_S2_FLAG_LOGGING_ACTIVE;
1335
1336                 /*
1337                  * Only actually map the page as writable if this was a write
1338                  * fault.
1339                  */
1340                 if (!write_fault)
1341                         writable = false;
1342         }
1343
1344         spin_lock(&kvm->mmu_lock);
1345         if (mmu_notifier_retry(kvm, mmu_seq))
1346                 goto out_unlock;
1347
1348         if (!hugetlb && !force_pte)
1349                 hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
1350
1351         if (hugetlb) {
1352                 pmd_t new_pmd = pfn_pmd(pfn, mem_type);
1353                 new_pmd = pmd_mkhuge(new_pmd);
1354                 if (writable) {
1355                         new_pmd = kvm_s2pmd_mkwrite(new_pmd);
1356                         kvm_set_pfn_dirty(pfn);
1357                 }
1358                 coherent_cache_guest_page(vcpu, pfn, PMD_SIZE);
1359                 ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
1360         } else {
1361                 pte_t new_pte = pfn_pte(pfn, mem_type);
1362
1363                 if (writable) {
1364                         new_pte = kvm_s2pte_mkwrite(new_pte);
1365                         kvm_set_pfn_dirty(pfn);
1366                         mark_page_dirty(kvm, gfn);
1367                 }
1368                 coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE);
1369                 ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
1370         }
1371
1372 out_unlock:
1373         spin_unlock(&kvm->mmu_lock);
1374         kvm_set_pfn_accessed(pfn);
1375         kvm_release_pfn_clean(pfn);
1376         return ret;
1377 }
1378
1379 /*
1380  * Resolve the access fault by making the page young again.
1381  * Note that because the faulting entry is guaranteed not to be
1382  * cached in the TLB, we don't need to invalidate anything.
1383  * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
1384  * so there is no need for atomic (pte|pmd)_mkyoung operations.
1385  */
1386 static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
1387 {
1388         pmd_t *pmd;
1389         pte_t *pte;
1390         kvm_pfn_t pfn;
1391         bool pfn_valid = false;
1392
1393         trace_kvm_access_fault(fault_ipa);
1394
1395         spin_lock(&vcpu->kvm->mmu_lock);
1396
1397         pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
1398         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1399                 goto out;
1400
1401         if (pmd_thp_or_huge(*pmd)) {    /* THP, HugeTLB */
1402                 *pmd = pmd_mkyoung(*pmd);
1403                 pfn = pmd_pfn(*pmd);
1404                 pfn_valid = true;
1405                 goto out;
1406         }
1407
1408         pte = pte_offset_kernel(pmd, fault_ipa);
1409         if (pte_none(*pte))             /* Nothing there either */
1410                 goto out;
1411
1412         *pte = pte_mkyoung(*pte);       /* Just a page... */
1413         pfn = pte_pfn(*pte);
1414         pfn_valid = true;
1415 out:
1416         spin_unlock(&vcpu->kvm->mmu_lock);
1417         if (pfn_valid)
1418                 kvm_set_pfn_accessed(pfn);
1419 }
1420
1421 /**
1422  * kvm_handle_guest_abort - handles all 2nd stage aborts
1423  * @vcpu:       the VCPU pointer
1424  * @run:        the kvm_run structure
1425  *
1426  * Any abort that gets to the host is almost guaranteed to be caused by a
1427  * missing second stage translation table entry, which can mean that either the
1428  * guest simply needs more memory and we must allocate an appropriate page or it
1429  * can mean that the guest tried to access I/O memory, which is emulated by user
1430  * space. The distinction is based on the IPA causing the fault and whether this
1431  * memory region has been registered as standard RAM by user space.
1432  */
1433 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
1434 {
1435         unsigned long fault_status;
1436         phys_addr_t fault_ipa;
1437         struct kvm_memory_slot *memslot;
1438         unsigned long hva;
1439         bool is_iabt, write_fault, writable;
1440         gfn_t gfn;
1441         int ret, idx;
1442
1443         is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1444         if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
1445                 kvm_inject_vabt(vcpu);
1446                 return 1;
1447         }
1448
1449         fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
1450
1451         trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
1452                               kvm_vcpu_get_hfar(vcpu), fault_ipa);
1453
1454         /* Check the stage-2 fault is trans. fault or write fault */
1455         fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
1456         if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
1457             fault_status != FSC_ACCESS) {
1458                 kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1459                         kvm_vcpu_trap_get_class(vcpu),
1460                         (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
1461                         (unsigned long)kvm_vcpu_get_hsr(vcpu));
1462                 return -EFAULT;
1463         }
1464
1465         idx = srcu_read_lock(&vcpu->kvm->srcu);
1466
1467         gfn = fault_ipa >> PAGE_SHIFT;
1468         memslot = gfn_to_memslot(vcpu->kvm, gfn);
1469         hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1470         write_fault = kvm_is_write_fault(vcpu);
1471         if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1472                 if (is_iabt) {
1473                         /* Prefetch Abort on I/O address */
1474                         kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1475                         ret = 1;
1476                         goto out_unlock;
1477                 }
1478
1479                 /*
1480                  * Check for a cache maintenance operation. Since we
1481                  * ended-up here, we know it is outside of any memory
1482                  * slot. But we can't find out if that is for a device,
1483                  * or if the guest is just being stupid. The only thing
1484                  * we know for sure is that this range cannot be cached.
1485                  *
1486                  * So let's assume that the guest is just being
1487                  * cautious, and skip the instruction.
1488                  */
1489                 if (kvm_vcpu_dabt_is_cm(vcpu)) {
1490                         kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
1491                         ret = 1;
1492                         goto out_unlock;
1493                 }
1494
1495                 /*
1496                  * The IPA is reported as [MAX:12], so we need to
1497                  * complement it with the bottom 12 bits from the
1498                  * faulting VA. This is always 12 bits, irrespective
1499                  * of the page size.
1500                  */
1501                 fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
1502                 ret = io_mem_abort(vcpu, run, fault_ipa);
1503                 goto out_unlock;
1504         }
1505
1506         /* Userspace should not be able to register out-of-bounds IPAs */
1507         VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
1508
1509         if (fault_status == FSC_ACCESS) {
1510                 handle_access_fault(vcpu, fault_ipa);
1511                 ret = 1;
1512                 goto out_unlock;
1513         }
1514
1515         ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1516         if (ret == 0)
1517                 ret = 1;
1518 out_unlock:
1519         srcu_read_unlock(&vcpu->kvm->srcu, idx);
1520         return ret;
1521 }
1522
1523 static int handle_hva_to_gpa(struct kvm *kvm,
1524                              unsigned long start,
1525                              unsigned long end,
1526                              int (*handler)(struct kvm *kvm,
1527                                             gpa_t gpa, void *data),
1528                              void *data)
1529 {
1530         struct kvm_memslots *slots;
1531         struct kvm_memory_slot *memslot;
1532         int ret = 0;
1533
1534         slots = kvm_memslots(kvm);
1535
1536         /* we only care about the pages that the guest sees */
1537         kvm_for_each_memslot(memslot, slots) {
1538                 unsigned long hva_start, hva_end;
1539                 gfn_t gfn, gfn_end;
1540
1541                 hva_start = max(start, memslot->userspace_addr);
1542                 hva_end = min(end, memslot->userspace_addr +
1543                                         (memslot->npages << PAGE_SHIFT));
1544                 if (hva_start >= hva_end)
1545                         continue;
1546
1547                 /*
1548                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
1549                  * {gfn_start, gfn_start+1, ..., gfn_end-1}.
1550                  */
1551                 gfn = hva_to_gfn_memslot(hva_start, memslot);
1552                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
1553
1554                 for (; gfn < gfn_end; ++gfn) {
1555                         gpa_t gpa = gfn << PAGE_SHIFT;
1556                         ret |= handler(kvm, gpa, data);
1557                 }
1558         }
1559
1560         return ret;
1561 }
1562
1563 static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1564 {
1565         unmap_stage2_range(kvm, gpa, PAGE_SIZE);
1566         return 0;
1567 }
1568
1569 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
1570 {
1571         unsigned long end = hva + PAGE_SIZE;
1572
1573         if (!kvm->arch.pgd)
1574                 return 0;
1575
1576         trace_kvm_unmap_hva(hva);
1577         handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
1578         return 0;
1579 }
1580
1581 int kvm_unmap_hva_range(struct kvm *kvm,
1582                         unsigned long start, unsigned long end)
1583 {
1584         if (!kvm->arch.pgd)
1585                 return 0;
1586
1587         trace_kvm_unmap_hva_range(start, end);
1588         handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
1589         return 0;
1590 }
1591
1592 static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, void *data)
1593 {
1594         pte_t *pte = (pte_t *)data;
1595
1596         /*
1597          * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
1598          * flag clear because MMU notifiers will have unmapped a huge PMD before
1599          * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
1600          * therefore stage2_set_pte() never needs to clear out a huge PMD
1601          * through this calling path.
1602          */
1603         stage2_set_pte(kvm, NULL, gpa, pte, 0);
1604         return 0;
1605 }
1606
1607
1608 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
1609 {
1610         unsigned long end = hva + PAGE_SIZE;
1611         pte_t stage2_pte;
1612
1613         if (!kvm->arch.pgd)
1614                 return;
1615
1616         trace_kvm_set_spte_hva(hva);
1617         stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
1618         handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
1619 }
1620
1621 static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1622 {
1623         pmd_t *pmd;
1624         pte_t *pte;
1625
1626         pmd = stage2_get_pmd(kvm, NULL, gpa);
1627         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1628                 return 0;
1629
1630         if (pmd_thp_or_huge(*pmd))      /* THP, HugeTLB */
1631                 return stage2_pmdp_test_and_clear_young(pmd);
1632
1633         pte = pte_offset_kernel(pmd, gpa);
1634         if (pte_none(*pte))
1635                 return 0;
1636
1637         return stage2_ptep_test_and_clear_young(pte);
1638 }
1639
1640 static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1641 {
1642         pmd_t *pmd;
1643         pte_t *pte;
1644
1645         pmd = stage2_get_pmd(kvm, NULL, gpa);
1646         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1647                 return 0;
1648
1649         if (pmd_thp_or_huge(*pmd))              /* THP, HugeTLB */
1650                 return pmd_young(*pmd);
1651
1652         pte = pte_offset_kernel(pmd, gpa);
1653         if (!pte_none(*pte))            /* Just a page... */
1654                 return pte_young(*pte);
1655
1656         return 0;
1657 }
1658
1659 int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
1660 {
1661         trace_kvm_age_hva(start, end);
1662         return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
1663 }
1664
1665 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
1666 {
1667         trace_kvm_test_age_hva(hva);
1668         return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
1669 }
1670
1671 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
1672 {
1673         mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
1674 }
1675
1676 phys_addr_t kvm_mmu_get_httbr(void)
1677 {
1678         if (__kvm_cpu_uses_extended_idmap())
1679                 return virt_to_phys(merged_hyp_pgd);
1680         else
1681                 return virt_to_phys(hyp_pgd);
1682 }
1683
1684 phys_addr_t kvm_get_idmap_vector(void)
1685 {
1686         return hyp_idmap_vector;
1687 }
1688
1689 phys_addr_t kvm_get_idmap_start(void)
1690 {
1691         return hyp_idmap_start;
1692 }
1693
1694 static int kvm_map_idmap_text(pgd_t *pgd)
1695 {
1696         int err;
1697
1698         /* Create the idmap in the boot page tables */
1699         err =   __create_hyp_mappings(pgd,
1700                                       hyp_idmap_start, hyp_idmap_end,
1701                                       __phys_to_pfn(hyp_idmap_start),
1702                                       PAGE_HYP_EXEC);
1703         if (err)
1704                 kvm_err("Failed to idmap %lx-%lx\n",
1705                         hyp_idmap_start, hyp_idmap_end);
1706
1707         return err;
1708 }
1709
1710 int kvm_mmu_init(void)
1711 {
1712         int err;
1713
1714         hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
1715         hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
1716         hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
1717
1718         /*
1719          * We rely on the linker script to ensure at build time that the HYP
1720          * init code does not cross a page boundary.
1721          */
1722         BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
1723
1724         kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
1725         kvm_info("HYP VA range: %lx:%lx\n",
1726                  kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
1727
1728         if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
1729             hyp_idmap_start <  kern_hyp_va(~0UL) &&
1730             hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
1731                 /*
1732                  * The idmap page is intersecting with the VA space,
1733                  * it is not safe to continue further.
1734                  */
1735                 kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
1736                 err = -EINVAL;
1737                 goto out;
1738         }
1739
1740         hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1741         if (!hyp_pgd) {
1742                 kvm_err("Hyp mode PGD not allocated\n");
1743                 err = -ENOMEM;
1744                 goto out;
1745         }
1746
1747         if (__kvm_cpu_uses_extended_idmap()) {
1748                 boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1749                                                          hyp_pgd_order);
1750                 if (!boot_hyp_pgd) {
1751                         kvm_err("Hyp boot PGD not allocated\n");
1752                         err = -ENOMEM;
1753                         goto out;
1754                 }
1755
1756                 err = kvm_map_idmap_text(boot_hyp_pgd);
1757                 if (err)
1758                         goto out;
1759
1760                 merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
1761                 if (!merged_hyp_pgd) {
1762                         kvm_err("Failed to allocate extra HYP pgd\n");
1763                         goto out;
1764                 }
1765                 __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd,
1766                                     hyp_idmap_start);
1767         } else {
1768                 err = kvm_map_idmap_text(hyp_pgd);
1769                 if (err)
1770                         goto out;
1771         }
1772
1773         return 0;
1774 out:
1775         free_hyp_pgds();
1776         return err;
1777 }
1778
1779 void kvm_arch_commit_memory_region(struct kvm *kvm,
1780                                    const struct kvm_userspace_memory_region *mem,
1781                                    const struct kvm_memory_slot *old,
1782                                    const struct kvm_memory_slot *new,
1783                                    enum kvm_mr_change change)
1784 {
1785         /*
1786          * At this point memslot has been committed and there is an
1787          * allocated dirty_bitmap[], dirty pages will be be tracked while the
1788          * memory slot is write protected.
1789          */
1790         if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES)
1791                 kvm_mmu_wp_memory_region(kvm, mem->slot);
1792 }
1793
1794 int kvm_arch_prepare_memory_region(struct kvm *kvm,
1795                                    struct kvm_memory_slot *memslot,
1796                                    const struct kvm_userspace_memory_region *mem,
1797                                    enum kvm_mr_change change)
1798 {
1799         hva_t hva = mem->userspace_addr;
1800         hva_t reg_end = hva + mem->memory_size;
1801         bool writable = !(mem->flags & KVM_MEM_READONLY);
1802         int ret = 0;
1803
1804         if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
1805                         change != KVM_MR_FLAGS_ONLY)
1806                 return 0;
1807
1808         /*
1809          * Prevent userspace from creating a memory region outside of the IPA
1810          * space addressable by the KVM guest IPA space.
1811          */
1812         if (memslot->base_gfn + memslot->npages >=
1813             (KVM_PHYS_SIZE >> PAGE_SHIFT))
1814                 return -EFAULT;
1815
1816         down_read(&current->mm->mmap_sem);
1817         /*
1818          * A memory region could potentially cover multiple VMAs, and any holes
1819          * between them, so iterate over all of them to find out if we can map
1820          * any of them right now.
1821          *
1822          *     +--------------------------------------------+
1823          * +---------------+----------------+   +----------------+
1824          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
1825          * +---------------+----------------+   +----------------+
1826          *     |               memory region                |
1827          *     +--------------------------------------------+
1828          */
1829         do {
1830                 struct vm_area_struct *vma = find_vma(current->mm, hva);
1831                 hva_t vm_start, vm_end;
1832
1833                 if (!vma || vma->vm_start >= reg_end)
1834                         break;
1835
1836                 /*
1837                  * Mapping a read-only VMA is only allowed if the
1838                  * memory region is configured as read-only.
1839                  */
1840                 if (writable && !(vma->vm_flags & VM_WRITE)) {
1841                         ret = -EPERM;
1842                         break;
1843                 }
1844
1845                 /*
1846                  * Take the intersection of this VMA with the memory region
1847                  */
1848                 vm_start = max(hva, vma->vm_start);
1849                 vm_end = min(reg_end, vma->vm_end);
1850
1851                 if (vma->vm_flags & VM_PFNMAP) {
1852                         gpa_t gpa = mem->guest_phys_addr +
1853                                     (vm_start - mem->userspace_addr);
1854                         phys_addr_t pa;
1855
1856                         pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
1857                         pa += vm_start - vma->vm_start;
1858
1859                         /* IO region dirty page logging not allowed */
1860                         if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
1861                                 ret = -EINVAL;
1862                                 goto out;
1863                         }
1864
1865                         ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
1866                                                     vm_end - vm_start,
1867                                                     writable);
1868                         if (ret)
1869                                 break;
1870                 }
1871                 hva = vm_end;
1872         } while (hva < reg_end);
1873
1874         if (change == KVM_MR_FLAGS_ONLY)
1875                 goto out;
1876
1877         spin_lock(&kvm->mmu_lock);
1878         if (ret)
1879                 unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
1880         else
1881                 stage2_flush_memslot(kvm, memslot);
1882         spin_unlock(&kvm->mmu_lock);
1883 out:
1884         up_read(&current->mm->mmap_sem);
1885         return ret;
1886 }
1887
1888 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
1889                            struct kvm_memory_slot *dont)
1890 {
1891 }
1892
1893 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
1894                             unsigned long npages)
1895 {
1896         return 0;
1897 }
1898
1899 void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
1900 {
1901 }
1902
1903 void kvm_arch_flush_shadow_all(struct kvm *kvm)
1904 {
1905         kvm_free_stage2_pgd(kvm);
1906 }
1907
1908 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
1909                                    struct kvm_memory_slot *slot)
1910 {
1911         gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
1912         phys_addr_t size = slot->npages << PAGE_SHIFT;
1913
1914         spin_lock(&kvm->mmu_lock);
1915         unmap_stage2_range(kvm, gpa, size);
1916         spin_unlock(&kvm->mmu_lock);
1917 }
1918
1919 /*
1920  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1921  *
1922  * Main problems:
1923  * - S/W ops are local to a CPU (not broadcast)
1924  * - We have line migration behind our back (speculation)
1925  * - System caches don't support S/W at all (damn!)
1926  *
1927  * In the face of the above, the best we can do is to try and convert
1928  * S/W ops to VA ops. Because the guest is not allowed to infer the
1929  * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1930  * which is a rather good thing for us.
1931  *
1932  * Also, it is only used when turning caches on/off ("The expected
1933  * usage of the cache maintenance instructions that operate by set/way
1934  * is associated with the cache maintenance instructions associated
1935  * with the powerdown and powerup of caches, if this is required by
1936  * the implementation.").
1937  *
1938  * We use the following policy:
1939  *
1940  * - If we trap a S/W operation, we enable VM trapping to detect
1941  *   caches being turned on/off, and do a full clean.
1942  *
1943  * - We flush the caches on both caches being turned on and off.
1944  *
1945  * - Once the caches are enabled, we stop trapping VM ops.
1946  */
1947 void kvm_set_way_flush(struct kvm_vcpu *vcpu)
1948 {
1949         unsigned long hcr = vcpu_get_hcr(vcpu);
1950
1951         /*
1952          * If this is the first time we do a S/W operation
1953          * (i.e. HCR_TVM not set) flush the whole memory, and set the
1954          * VM trapping.
1955          *
1956          * Otherwise, rely on the VM trapping to wait for the MMU +
1957          * Caches to be turned off. At that point, we'll be able to
1958          * clean the caches again.
1959          */
1960         if (!(hcr & HCR_TVM)) {
1961                 trace_kvm_set_way_flush(*vcpu_pc(vcpu),
1962                                         vcpu_has_cache_enabled(vcpu));
1963                 stage2_flush_vm(vcpu->kvm);
1964                 vcpu_set_hcr(vcpu, hcr | HCR_TVM);
1965         }
1966 }
1967
1968 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
1969 {
1970         bool now_enabled = vcpu_has_cache_enabled(vcpu);
1971
1972         /*
1973          * If switching the MMU+caches on, need to invalidate the caches.
1974          * If switching it off, need to clean the caches.
1975          * Clean + invalidate does the trick always.
1976          */
1977         if (now_enabled != was_enabled)
1978                 stage2_flush_vm(vcpu->kvm);
1979
1980         /* Caches are now on, stop trapping VM ops (until a S/W op) */
1981         if (now_enabled)
1982                 vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);
1983
1984         trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
1985 }