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 extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];
  36
  37 static pgd_t *boot_hyp_pgd;
  38 static pgd_t *hyp_pgd;
  39 static pgd_t *merged_hyp_pgd;
  40 static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
  41
  42 static unsigned long hyp_idmap_start;
  43 static unsigned long hyp_idmap_end;
  44 static phys_addr_t hyp_idmap_vector;
  45
  46 #define S2_PGD_SIZE     (PTRS_PER_S2_PGD * sizeof(pgd_t))
  47 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
  48
  49 #define KVM_S2PTE_FLAG_IS_IOMAP         (1UL << 0)
  50 #define KVM_S2_FLAG_LOGGING_ACTIVE      (1UL << 1)
  51
  52 static bool memslot_is_logging(struct kvm_memory_slot *memslot)
  53 {
  54         return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
  55 }
  56
  57 /**
  58  * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
  59  * @kvm:        pointer to kvm structure.
  60  *
  61  * Interface to HYP function to flush all VM TLB entries
  62  */
  63 void kvm_flush_remote_tlbs(struct kvm *kvm)
  64 {
  65         kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
  66 }
  67
  68 static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
  69 {
  70         kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
  71 }
  72
  73 /*
  74  * D-Cache management functions. They take the page table entries by
  75  * value, as they are flushing the cache using the kernel mapping (or
  76  * kmap on 32bit).
  77  */
  78 static void kvm_flush_dcache_pte(pte_t pte)
  79 {
  80         __kvm_flush_dcache_pte(pte);
  81 }
  82
  83 static void kvm_flush_dcache_pmd(pmd_t pmd)
  84 {
  85         __kvm_flush_dcache_pmd(pmd);
  86 }
  87
  88 static void kvm_flush_dcache_pud(pud_t pud)
  89 {
  90         __kvm_flush_dcache_pud(pud);
  91 }
  92
  93 static bool kvm_is_device_pfn(unsigned long pfn)
  94 {
  95         return !pfn_valid(pfn);
  96 }
  97
  98 /**
  99  * stage2_dissolve_pmd() - clear and flush huge PMD entry
 100  * @kvm:        pointer to kvm structure.
 101  * @addr:       IPA
 102  * @pmd:        pmd pointer for IPA
 103  *
 104  * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
 105  * pages in the range dirty.
 106  */
 107 static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
 108 {
 109         if (!pmd_thp_or_huge(*pmd))
 110                 return;
 111
 112         pmd_clear(pmd);
 113         kvm_tlb_flush_vmid_ipa(kvm, addr);
 114         put_page(virt_to_page(pmd));
 115 }
 116
 117 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
 118                                   int min, int max)
 119 {
 120         void *page;
 121
 122         BUG_ON(max > KVM_NR_MEM_OBJS);
 123         if (cache->nobjs >= min)
 124                 return 0;
 125         while (cache->nobjs < max) {
 126                 page = (void *)__get_free_page(PGALLOC_GFP);
 127                 if (!page)
 128                         return -ENOMEM;
 129                 cache->objects[cache->nobjs++] = page;
 130         }
 131         return 0;
 132 }
 133
 134 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
 135 {
 136         while (mc->nobjs)
 137                 free_page((unsigned long)mc->objects[--mc->nobjs]);
 138 }
 139
 140 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
 141 {
 142         void *p;
 143
 144         BUG_ON(!mc || !mc->nobjs);
 145         p = mc->objects[--mc->nobjs];
 146         return p;
 147 }
 148
 149 static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr)
 150 {
 151         pud_t *pud_table __maybe_unused = stage2_pud_offset(pgd, 0UL);
 152         stage2_pgd_clear(pgd);
 153         kvm_tlb_flush_vmid_ipa(kvm, addr);
 154         stage2_pud_free(pud_table);
 155         put_page(virt_to_page(pgd));
 156 }
 157
 158 static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
 159 {
 160         pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(pud, 0);
 161         VM_BUG_ON(stage2_pud_huge(*pud));
 162         stage2_pud_clear(pud);
 163         kvm_tlb_flush_vmid_ipa(kvm, addr);
 164         stage2_pmd_free(pmd_table);
 165         put_page(virt_to_page(pud));
 166 }
 167
 168 static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
 169 {
 170         pte_t *pte_table = pte_offset_kernel(pmd, 0);
 171         VM_BUG_ON(pmd_thp_or_huge(*pmd));
 172         pmd_clear(pmd);
 173         kvm_tlb_flush_vmid_ipa(kvm, addr);
 174         pte_free_kernel(NULL, pte_table);
 175         put_page(virt_to_page(pmd));
 176 }
 177
 178 /*
 179  * Unmapping vs dcache management:
 180  *
 181  * If a guest maps certain memory pages as uncached, all writes will
 182  * bypass the data cache and go directly to RAM.  However, the CPUs
 183  * can still speculate reads (not writes) and fill cache lines with
 184  * data.
 185  *
 186  * Those cache lines will be *clean* cache lines though, so a
 187  * clean+invalidate operation is equivalent to an invalidate
 188  * operation, because no cache lines are marked dirty.
 189  *
 190  * Those clean cache lines could be filled prior to an uncached write
 191  * by the guest, and the cache coherent IO subsystem would therefore
 192  * end up writing old data to disk.
 193  *
 194  * This is why right after unmapping a page/section and invalidating
 195  * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
 196  * the IO subsystem will never hit in the cache.
 197  */
 198 static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd,
 199                        phys_addr_t addr, phys_addr_t end)
 200 {
 201         phys_addr_t start_addr = addr;
 202         pte_t *pte, *start_pte;
 203
 204         start_pte = pte = pte_offset_kernel(pmd, addr);
 205         do {
 206                 if (!pte_none(*pte)) {
 207                         pte_t old_pte = *pte;
 208
 209                         kvm_set_pte(pte, __pte(0));
 210                         kvm_tlb_flush_vmid_ipa(kvm, addr);
 211
 212                         /* No need to invalidate the cache for device mappings */
 213                         if (!kvm_is_device_pfn(pte_pfn(old_pte)))
 214                                 kvm_flush_dcache_pte(old_pte);
 215
 216                         put_page(virt_to_page(pte));
 217                 }
 218         } while (pte++, addr += PAGE_SIZE, addr != end);
 219
 220         if (stage2_pte_table_empty(start_pte))
 221                 clear_stage2_pmd_entry(kvm, pmd, start_addr);
 222 }
 223
 224 static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud,
 225                        phys_addr_t addr, phys_addr_t end)
 226 {
 227         phys_addr_t next, start_addr = addr;
 228         pmd_t *pmd, *start_pmd;
 229
 230         start_pmd = pmd = stage2_pmd_offset(pud, addr);
 231         do {
 232                 next = stage2_pmd_addr_end(addr, end);
 233                 if (!pmd_none(*pmd)) {
 234                         if (pmd_thp_or_huge(*pmd)) {
 235                                 pmd_t old_pmd = *pmd;
 236
 237                                 pmd_clear(pmd);
 238                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 239
 240                                 kvm_flush_dcache_pmd(old_pmd);
 241
 242                                 put_page(virt_to_page(pmd));
 243                         } else {
 244                                 unmap_stage2_ptes(kvm, pmd, addr, next);
 245                         }
 246                 }
 247         } while (pmd++, addr = next, addr != end);
 248
 249         if (stage2_pmd_table_empty(start_pmd))
 250                 clear_stage2_pud_entry(kvm, pud, start_addr);
 251 }
 252
 253 static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd,
 254                        phys_addr_t addr, phys_addr_t end)
 255 {
 256         phys_addr_t next, start_addr = addr;
 257         pud_t *pud, *start_pud;
 258
 259         start_pud = pud = stage2_pud_offset(pgd, addr);
 260         do {
 261                 next = stage2_pud_addr_end(addr, end);
 262                 if (!stage2_pud_none(*pud)) {
 263                         if (stage2_pud_huge(*pud)) {
 264                                 pud_t old_pud = *pud;
 265
 266                                 stage2_pud_clear(pud);
 267                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 268                                 kvm_flush_dcache_pud(old_pud);
 269                                 put_page(virt_to_page(pud));
 270                         } else {
 271                                 unmap_stage2_pmds(kvm, pud, addr, next);
 272                         }
 273                 }
 274         } while (pud++, addr = next, addr != end);
 275
 276         if (stage2_pud_table_empty(start_pud))
 277                 clear_stage2_pgd_entry(kvm, pgd, start_addr);
 278 }
 279
 280 /**
 281  * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
 282  * @kvm:   The VM pointer
 283  * @start: The intermediate physical base address of the range to unmap
 284  * @size:  The size of the area to unmap
 285  *
 286  * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
 287  * be called while holding mmu_lock (unless for freeing the stage2 pgd before
 288  * destroying the VM), otherwise another faulting VCPU may come in and mess
 289  * with things behind our backs.
 290  */
 291 static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
 292 {
 293         pgd_t *pgd;
 294         phys_addr_t addr = start, end = start + size;
 295         phys_addr_t next;
 296
 297         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
 298         do {
 299                 next = stage2_pgd_addr_end(addr, end);
 300                 if (!stage2_pgd_none(*pgd))
 301                         unmap_stage2_puds(kvm, pgd, addr, next);
 302         } while (pgd++, addr = next, addr != end);
 303 }
 304
 305 static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
 306                               phys_addr_t addr, phys_addr_t end)
 307 {
 308         pte_t *pte;
 309
 310         pte = pte_offset_kernel(pmd, addr);
 311         do {
 312                 if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte)))
 313                         kvm_flush_dcache_pte(*pte);
 314         } while (pte++, addr += PAGE_SIZE, addr != end);
 315 }
 316
 317 static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
 318                               phys_addr_t addr, phys_addr_t end)
 319 {
 320         pmd_t *pmd;
 321         phys_addr_t next;
 322
 323         pmd = stage2_pmd_offset(pud, addr);
 324         do {
 325                 next = stage2_pmd_addr_end(addr, end);
 326                 if (!pmd_none(*pmd)) {
 327                         if (pmd_thp_or_huge(*pmd))
 328                                 kvm_flush_dcache_pmd(*pmd);
 329                         else
 330                                 stage2_flush_ptes(kvm, pmd, addr, next);
 331                 }
 332         } while (pmd++, addr = next, addr != end);
 333 }
 334
 335 static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd,
 336                               phys_addr_t addr, phys_addr_t end)
 337 {
 338         pud_t *pud;
 339         phys_addr_t next;
 340
 341         pud = stage2_pud_offset(pgd, addr);
 342         do {
 343                 next = stage2_pud_addr_end(addr, end);
 344                 if (!stage2_pud_none(*pud)) {
 345                         if (stage2_pud_huge(*pud))
 346                                 kvm_flush_dcache_pud(*pud);
 347                         else
 348                                 stage2_flush_pmds(kvm, pud, addr, next);
 349                 }
 350         } while (pud++, addr = next, addr != end);
 351 }
 352
 353 static void stage2_flush_memslot(struct kvm *kvm,
 354                                  struct kvm_memory_slot *memslot)
 355 {
 356         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
 357         phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
 358         phys_addr_t next;
 359         pgd_t *pgd;
 360
 361         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
 362         do {
 363                 next = stage2_pgd_addr_end(addr, end);
 364                 stage2_flush_puds(kvm, pgd, addr, next);
 365         } while (pgd++, addr = next, addr != end);
 366 }
 367
 368 /**
 369  * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
 370  * @kvm: The struct kvm pointer
 371  *
 372  * Go through the stage 2 page tables and invalidate any cache lines
 373  * backing memory already mapped to the VM.
 374  */
 375 static void stage2_flush_vm(struct kvm *kvm)
 376 {
 377         struct kvm_memslots *slots;
 378         struct kvm_memory_slot *memslot;
 379         int idx;
 380
 381         idx = srcu_read_lock(&kvm->srcu);
 382         spin_lock(&kvm->mmu_lock);
 383
 384         slots = kvm_memslots(kvm);
 385         kvm_for_each_memslot(memslot, slots)
 386                 stage2_flush_memslot(kvm, memslot);
 387
 388         spin_unlock(&kvm->mmu_lock);
 389         srcu_read_unlock(&kvm->srcu, idx);
 390 }
 391
 392 static void clear_hyp_pgd_entry(pgd_t *pgd)
 393 {
 394         pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL);
 395         pgd_clear(pgd);
 396         pud_free(NULL, pud_table);
 397         put_page(virt_to_page(pgd));
 398 }
 399
 400 static void clear_hyp_pud_entry(pud_t *pud)
 401 {
 402         pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0);
 403         VM_BUG_ON(pud_huge(*pud));
 404         pud_clear(pud);
 405         pmd_free(NULL, pmd_table);
 406         put_page(virt_to_page(pud));
 407 }
 408
 409 static void clear_hyp_pmd_entry(pmd_t *pmd)
 410 {
 411         pte_t *pte_table = pte_offset_kernel(pmd, 0);
 412         VM_BUG_ON(pmd_thp_or_huge(*pmd));
 413         pmd_clear(pmd);
 414         pte_free_kernel(NULL, pte_table);
 415         put_page(virt_to_page(pmd));
 416 }
 417
 418 static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
 419 {
 420         pte_t *pte, *start_pte;
 421
 422         start_pte = pte = pte_offset_kernel(pmd, addr);
 423         do {
 424                 if (!pte_none(*pte)) {
 425                         kvm_set_pte(pte, __pte(0));
 426                         put_page(virt_to_page(pte));
 427                 }
 428         } while (pte++, addr += PAGE_SIZE, addr != end);
 429
 430         if (hyp_pte_table_empty(start_pte))
 431                 clear_hyp_pmd_entry(pmd);
 432 }
 433
 434 static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
 435 {
 436         phys_addr_t next;
 437         pmd_t *pmd, *start_pmd;
 438
 439         start_pmd = pmd = pmd_offset(pud, addr);
 440         do {
 441                 next = pmd_addr_end(addr, end);
 442                 /* Hyp doesn't use huge pmds */
 443                 if (!pmd_none(*pmd))
 444                         unmap_hyp_ptes(pmd, addr, next);
 445         } while (pmd++, addr = next, addr != end);
 446
 447         if (hyp_pmd_table_empty(start_pmd))
 448                 clear_hyp_pud_entry(pud);
 449 }
 450
 451 static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
 452 {
 453         phys_addr_t next;
 454         pud_t *pud, *start_pud;
 455
 456         start_pud = pud = pud_offset(pgd, addr);
 457         do {
 458                 next = pud_addr_end(addr, end);
 459                 /* Hyp doesn't use huge puds */
 460                 if (!pud_none(*pud))
 461                         unmap_hyp_pmds(pud, addr, next);
 462         } while (pud++, addr = next, addr != end);
 463
 464         if (hyp_pud_table_empty(start_pud))
 465                 clear_hyp_pgd_entry(pgd);
 466 }
 467
 468 static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size)
 469 {
 470         pgd_t *pgd;
 471         phys_addr_t addr = start, end = start + size;
 472         phys_addr_t next;
 473
 474         /*
 475          * We don't unmap anything from HYP, except at the hyp tear down.
 476          * Hence, we don't have to invalidate the TLBs here.
 477          */
 478         pgd = pgdp + pgd_index(addr);
 479         do {
 480                 next = pgd_addr_end(addr, end);
 481                 if (!pgd_none(*pgd))
 482                         unmap_hyp_puds(pgd, addr, next);
 483         } while (pgd++, addr = next, addr != end);
 484 }
 485
 486 /**
 487  * free_boot_hyp_pgd - free HYP boot page tables
 488  *
 489  * Free the HYP boot page tables. The bounce page is also freed.
 490  */
 491 void free_boot_hyp_pgd(void)
 492 {
 493         mutex_lock(&kvm_hyp_pgd_mutex);
 494
 495         if (boot_hyp_pgd) {
 496                 unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
 497                 unmap_hyp_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
 498                 free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
 499                 boot_hyp_pgd = NULL;
 500         }
 501
 502         if (hyp_pgd)
 503                 unmap_hyp_range(hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
 504
 505         mutex_unlock(&kvm_hyp_pgd_mutex);
 506 }
 507
 508 /**
 509  * free_hyp_pgds - free Hyp-mode page tables
 510  *
 511  * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
 512  * therefore contains either mappings in the kernel memory area (above
 513  * PAGE_OFFSET), or device mappings in the vmalloc range (from
 514  * VMALLOC_START to VMALLOC_END).
 515  *
 516  * boot_hyp_pgd should only map two pages for the init code.
 517  */
 518 void free_hyp_pgds(void)
 519 {
 520         unsigned long addr;
 521
 522         free_boot_hyp_pgd();
 523
 524         mutex_lock(&kvm_hyp_pgd_mutex);
 525
 526         if (hyp_pgd) {
 527                 for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
 528                         unmap_hyp_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
 529                 for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
 530                         unmap_hyp_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
 531
 532                 free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
 533                 hyp_pgd = NULL;
 534         }
 535         if (merged_hyp_pgd) {
 536                 clear_page(merged_hyp_pgd);
 537                 free_page((unsigned long)merged_hyp_pgd);
 538                 merged_hyp_pgd = NULL;
 539         }
 540
 541         mutex_unlock(&kvm_hyp_pgd_mutex);
 542 }
 543
 544 static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
 545                                     unsigned long end, unsigned long pfn,
 546                                     pgprot_t prot)
 547 {
 548         pte_t *pte;
 549         unsigned long addr;
 550
 551         addr = start;
 552         do {
 553                 pte = pte_offset_kernel(pmd, addr);
 554                 kvm_set_pte(pte, pfn_pte(pfn, prot));
 555                 get_page(virt_to_page(pte));
 556                 kvm_flush_dcache_to_poc(pte, sizeof(*pte));
 557                 pfn++;
 558         } while (addr += PAGE_SIZE, addr != end);
 559 }
 560
 561 static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
 562                                    unsigned long end, unsigned long pfn,
 563                                    pgprot_t prot)
 564 {
 565         pmd_t *pmd;
 566         pte_t *pte;
 567         unsigned long addr, next;
 568
 569         addr = start;
 570         do {
 571                 pmd = pmd_offset(pud, addr);
 572
 573                 BUG_ON(pmd_sect(*pmd));
 574
 575                 if (pmd_none(*pmd)) {
 576                         pte = pte_alloc_one_kernel(NULL, addr);
 577                         if (!pte) {
 578                                 kvm_err("Cannot allocate Hyp pte\n");
 579                                 return -ENOMEM;
 580                         }
 581                         pmd_populate_kernel(NULL, pmd, pte);
 582                         get_page(virt_to_page(pmd));
 583                         kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
 584                 }
 585
 586                 next = pmd_addr_end(addr, end);
 587
 588                 create_hyp_pte_mappings(pmd, addr, next, pfn, prot);
 589                 pfn += (next - addr) >> PAGE_SHIFT;
 590         } while (addr = next, addr != end);
 591
 592         return 0;
 593 }
 594
 595 static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
 596                                    unsigned long end, unsigned long pfn,
 597                                    pgprot_t prot)
 598 {
 599         pud_t *pud;
 600         pmd_t *pmd;
 601         unsigned long addr, next;
 602         int ret;
 603
 604         addr = start;
 605         do {
 606                 pud = pud_offset(pgd, addr);
 607
 608                 if (pud_none_or_clear_bad(pud)) {
 609                         pmd = pmd_alloc_one(NULL, addr);
 610                         if (!pmd) {
 611                                 kvm_err("Cannot allocate Hyp pmd\n");
 612                                 return -ENOMEM;
 613                         }
 614                         pud_populate(NULL, pud, pmd);
 615                         get_page(virt_to_page(pud));
 616                         kvm_flush_dcache_to_poc(pud, sizeof(*pud));
 617                 }
 618
 619                 next = pud_addr_end(addr, end);
 620                 ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
 621                 if (ret)
 622                         return ret;
 623                 pfn += (next - addr) >> PAGE_SHIFT;
 624         } while (addr = next, addr != end);
 625
 626         return 0;
 627 }
 628
 629 static int __create_hyp_mappings(pgd_t *pgdp,
 630                                  unsigned long start, unsigned long end,
 631                                  unsigned long pfn, pgprot_t prot)
 632 {
 633         pgd_t *pgd;
 634         pud_t *pud;
 635         unsigned long addr, next;
 636         int err = 0;
 637
 638         mutex_lock(&kvm_hyp_pgd_mutex);
 639         addr = start & PAGE_MASK;
 640         end = PAGE_ALIGN(end);
 641         do {
 642                 pgd = pgdp + pgd_index(addr);
 643
 644                 if (pgd_none(*pgd)) {
 645                         pud = pud_alloc_one(NULL, addr);
 646                         if (!pud) {
 647                                 kvm_err("Cannot allocate Hyp pud\n");
 648                                 err = -ENOMEM;
 649                                 goto out;
 650                         }
 651                         pgd_populate(NULL, pgd, pud);
 652                         get_page(virt_to_page(pgd));
 653                         kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
 654                 }
 655
 656                 next = pgd_addr_end(addr, end);
 657                 err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
 658                 if (err)
 659                         goto out;
 660                 pfn += (next - addr) >> PAGE_SHIFT;
 661         } while (addr = next, addr != end);
 662 out:
 663         mutex_unlock(&kvm_hyp_pgd_mutex);
 664         return err;
 665 }
 666
 667 static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
 668 {
 669         if (!is_vmalloc_addr(kaddr)) {
 670                 BUG_ON(!virt_addr_valid(kaddr));
 671                 return __pa(kaddr);
 672         } else {
 673                 return page_to_phys(vmalloc_to_page(kaddr)) +
 674                        offset_in_page(kaddr);
 675         }
 676 }
 677
 678 /**
 679  * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
 680  * @from:       The virtual kernel start address of the range
 681  * @to:         The virtual kernel end address of the range (exclusive)
 682  *
 683  * The same virtual address as the kernel virtual address is also used
 684  * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
 685  * physical pages.
 686  */
 687 int create_hyp_mappings(void *from, void *to)
 688 {
 689         phys_addr_t phys_addr;
 690         unsigned long virt_addr;
 691         unsigned long start = KERN_TO_HYP((unsigned long)from);
 692         unsigned long end = KERN_TO_HYP((unsigned long)to);
 693
 694         if (is_kernel_in_hyp_mode())
 695                 return 0;
 696
 697         start = start & PAGE_MASK;
 698         end = PAGE_ALIGN(end);
 699
 700         for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
 701                 int err;
 702
 703                 phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
 704                 err = __create_hyp_mappings(hyp_pgd, virt_addr,
 705                                             virt_addr + PAGE_SIZE,
 706                                             __phys_to_pfn(phys_addr),
 707                                             PAGE_HYP);
 708                 if (err)
 709                         return err;
 710         }
 711
 712         return 0;
 713 }
 714
 715 /**
 716  * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
 717  * @from:       The kernel start VA of the range
 718  * @to:         The kernel end VA of the range (exclusive)
 719  * @phys_addr:  The physical start address which gets mapped
 720  *
 721  * The resulting HYP VA is the same as the kernel VA, modulo
 722  * HYP_PAGE_OFFSET.
 723  */
 724 int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
 725 {
 726         unsigned long start = KERN_TO_HYP((unsigned long)from);
 727         unsigned long end = KERN_TO_HYP((unsigned long)to);
 728
 729         if (is_kernel_in_hyp_mode())
 730                 return 0;
 731
 732         /* Check for a valid kernel IO mapping */
 733         if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
 734                 return -EINVAL;
 735
 736         return __create_hyp_mappings(hyp_pgd, start, end,
 737                                      __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
 738 }
 739
 740 /**
 741  * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
 742  * @kvm:        The KVM struct pointer for the VM.
 743  *
 744  * Allocates only the stage-2 HW PGD level table(s) (can support either full
 745  * 40-bit input addresses or limited to 32-bit input addresses). Clears the
 746  * allocated pages.
 747  *
 748  * Note we don't need locking here as this is only called when the VM is
 749  * created, which can only be done once.
 750  */
 751 int kvm_alloc_stage2_pgd(struct kvm *kvm)
 752 {
 753         pgd_t *pgd;
 754
 755         if (kvm->arch.pgd != NULL) {
 756                 kvm_err("kvm_arch already initialized?\n");
 757                 return -EINVAL;
 758         }
 759
 760         /* Allocate the HW PGD, making sure that each page gets its own refcount */
 761         pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO);
 762         if (!pgd)
 763                 return -ENOMEM;
 764
 765         kvm_clean_pgd(pgd);
 766         kvm->arch.pgd = pgd;
 767         return 0;
 768 }
 769
 770 static void stage2_unmap_memslot(struct kvm *kvm,
 771                                  struct kvm_memory_slot *memslot)
 772 {
 773         hva_t hva = memslot->userspace_addr;
 774         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
 775         phys_addr_t size = PAGE_SIZE * memslot->npages;
 776         hva_t reg_end = hva + size;
 777
 778         /*
 779          * A memory region could potentially cover multiple VMAs, and any holes
 780          * between them, so iterate over all of them to find out if we should
 781          * unmap any of them.
 782          *
 783          *     +--------------------------------------------+
 784          * +---------------+----------------+   +----------------+
 785          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
 786          * +---------------+----------------+   +----------------+
 787          *     |               memory region                |
 788          *     +--------------------------------------------+
 789          */
 790         do {
 791                 struct vm_area_struct *vma = find_vma(current->mm, hva);
 792                 hva_t vm_start, vm_end;
 793
 794                 if (!vma || vma->vm_start >= reg_end)
 795                         break;
 796
 797                 /*
 798                  * Take the intersection of this VMA with the memory region
 799                  */
 800                 vm_start = max(hva, vma->vm_start);
 801                 vm_end = min(reg_end, vma->vm_end);
 802
 803                 if (!(vma->vm_flags & VM_PFNMAP)) {
 804                         gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
 805                         unmap_stage2_range(kvm, gpa, vm_end - vm_start);
 806                 }
 807                 hva = vm_end;
 808         } while (hva < reg_end);
 809 }
 810
 811 /**
 812  * stage2_unmap_vm - Unmap Stage-2 RAM mappings
 813  * @kvm: The struct kvm pointer
 814  *
 815  * Go through the memregions and unmap any reguler RAM
 816  * backing memory already mapped to the VM.
 817  */
 818 void stage2_unmap_vm(struct kvm *kvm)
 819 {
 820         struct kvm_memslots *slots;
 821         struct kvm_memory_slot *memslot;
 822         int idx;
 823
 824         idx = srcu_read_lock(&kvm->srcu);
 825         spin_lock(&kvm->mmu_lock);
 826
 827         slots = kvm_memslots(kvm);
 828         kvm_for_each_memslot(memslot, slots)
 829                 stage2_unmap_memslot(kvm, memslot);
 830
 831         spin_unlock(&kvm->mmu_lock);
 832         srcu_read_unlock(&kvm->srcu, idx);
 833 }
 834
 835 /**
 836  * kvm_free_stage2_pgd - free all stage-2 tables
 837  * @kvm:        The KVM struct pointer for the VM.
 838  *
 839  * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
 840  * underlying level-2 and level-3 tables before freeing the actual level-1 table
 841  * and setting the struct pointer to NULL.
 842  *
 843  * Note we don't need locking here as this is only called when the VM is
 844  * destroyed, which can only be done once.
 845  */
 846 void kvm_free_stage2_pgd(struct kvm *kvm)
 847 {
 848         if (kvm->arch.pgd == NULL)
 849                 return;
 850
 851         unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
 852         /* Free the HW pgd, one page at a time */
 853         free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE);
 854         kvm->arch.pgd = NULL;
 855 }
 856
 857 static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 858                              phys_addr_t addr)
 859 {
 860         pgd_t *pgd;
 861         pud_t *pud;
 862
 863         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
 864         if (WARN_ON(stage2_pgd_none(*pgd))) {
 865                 if (!cache)
 866                         return NULL;
 867                 pud = mmu_memory_cache_alloc(cache);
 868                 stage2_pgd_populate(pgd, pud);
 869                 get_page(virt_to_page(pgd));
 870         }
 871
 872         return stage2_pud_offset(pgd, addr);
 873 }
 874
 875 static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 876                              phys_addr_t addr)
 877 {
 878         pud_t *pud;
 879         pmd_t *pmd;
 880
 881         pud = stage2_get_pud(kvm, cache, addr);
 882         if (stage2_pud_none(*pud)) {
 883                 if (!cache)
 884                         return NULL;
 885                 pmd = mmu_memory_cache_alloc(cache);
 886                 stage2_pud_populate(pud, pmd);
 887                 get_page(virt_to_page(pud));
 888         }
 889
 890         return stage2_pmd_offset(pud, addr);
 891 }
 892
 893 static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
 894                                *cache, phys_addr_t addr, const pmd_t *new_pmd)
 895 {
 896         pmd_t *pmd, old_pmd;
 897
 898         pmd = stage2_get_pmd(kvm, cache, addr);
 899         VM_BUG_ON(!pmd);
 900
 901         /*
 902          * Mapping in huge pages should only happen through a fault.  If a
 903          * page is merged into a transparent huge page, the individual
 904          * subpages of that huge page should be unmapped through MMU
 905          * notifiers before we get here.
 906          *
 907          * Merging of CompoundPages is not supported; they should become
 908          * splitting first, unmapped, merged, and mapped back in on-demand.
 909          */
 910         VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd));
 911
 912         old_pmd = *pmd;
 913         if (pmd_present(old_pmd)) {
 914                 pmd_clear(pmd);
 915                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 916         } else {
 917                 get_page(virt_to_page(pmd));
 918         }
 919
 920         kvm_set_pmd(pmd, *new_pmd);
 921         return 0;
 922 }
 923
 924 static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 925                           phys_addr_t addr, const pte_t *new_pte,
 926                           unsigned long flags)
 927 {
 928         pmd_t *pmd;
 929         pte_t *pte, old_pte;
 930         bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
 931         bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;
 932
 933         VM_BUG_ON(logging_active && !cache);
 934
 935         /* Create stage-2 page table mapping - Levels 0 and 1 */
 936         pmd = stage2_get_pmd(kvm, cache, addr);
 937         if (!pmd) {
 938                 /*
 939                  * Ignore calls from kvm_set_spte_hva for unallocated
 940                  * address ranges.
 941                  */
 942                 return 0;
 943         }
 944
 945         /*
 946          * While dirty page logging - dissolve huge PMD, then continue on to
 947          * allocate page.
 948          */
 949         if (logging_active)
 950                 stage2_dissolve_pmd(kvm, addr, pmd);
 951
 952         /* Create stage-2 page mappings - Level 2 */
 953         if (pmd_none(*pmd)) {
 954                 if (!cache)
 955                         return 0; /* ignore calls from kvm_set_spte_hva */
 956                 pte = mmu_memory_cache_alloc(cache);
 957                 kvm_clean_pte(pte);
 958                 pmd_populate_kernel(NULL, pmd, pte);
 959                 get_page(virt_to_page(pmd));
 960         }
 961
 962         pte = pte_offset_kernel(pmd, addr);
 963
 964         if (iomap && pte_present(*pte))
 965                 return -EFAULT;
 966
 967         /* Create 2nd stage page table mapping - Level 3 */
 968         old_pte = *pte;
 969         if (pte_present(old_pte)) {
 970                 kvm_set_pte(pte, __pte(0));
 971                 kvm_tlb_flush_vmid_ipa(kvm, addr);
 972         } else {
 973                 get_page(virt_to_page(pte));
 974         }
 975
 976         kvm_set_pte(pte, *new_pte);
 977         return 0;
 978 }
 979
 980 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 981 static int stage2_ptep_test_and_clear_young(pte_t *pte)
 982 {
 983         if (pte_young(*pte)) {
 984                 *pte = pte_mkold(*pte);
 985                 return 1;
 986         }
 987         return 0;
 988 }
 989 #else
 990 static int stage2_ptep_test_and_clear_young(pte_t *pte)
 991 {
 992         return __ptep_test_and_clear_young(pte);
 993 }
 994 #endif
 995
 996 static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
 997 {
 998         return stage2_ptep_test_and_clear_young((pte_t *)pmd);
 999 }
1000
1001 /**
1002  * kvm_phys_addr_ioremap - map a device range to guest IPA
1003  *
1004  * @kvm:        The KVM pointer
1005  * @guest_ipa:  The IPA at which to insert the mapping
1006  * @pa:         The physical address of the device
1007  * @size:       The size of the mapping
1008  */
1009 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
1010                           phys_addr_t pa, unsigned long size, bool writable)
1011 {
1012         phys_addr_t addr, end;
1013         int ret = 0;
1014         unsigned long pfn;
1015         struct kvm_mmu_memory_cache cache = { 0, };
1016
1017         end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
1018         pfn = __phys_to_pfn(pa);
1019
1020         for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
1021                 pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
1022
1023                 if (writable)
1024                         pte = kvm_s2pte_mkwrite(pte);
1025
1026                 ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
1027                                                 KVM_NR_MEM_OBJS);
1028                 if (ret)
1029                         goto out;
1030                 spin_lock(&kvm->mmu_lock);
1031                 ret = stage2_set_pte(kvm, &cache, addr, &pte,
1032                                                 KVM_S2PTE_FLAG_IS_IOMAP);
1033                 spin_unlock(&kvm->mmu_lock);
1034                 if (ret)
1035                         goto out;
1036
1037                 pfn++;
1038         }
1039
1040 out:
1041         mmu_free_memory_cache(&cache);
1042         return ret;
1043 }
1044
1045 static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
1046 {
1047         kvm_pfn_t pfn = *pfnp;
1048         gfn_t gfn = *ipap >> PAGE_SHIFT;
1049
1050         if (PageTransCompoundMap(pfn_to_page(pfn))) {
1051                 unsigned long mask;
1052                 /*
1053                  * The address we faulted on is backed by a transparent huge
1054                  * page.  However, because we map the compound huge page and
1055                  * not the individual tail page, we need to transfer the
1056                  * refcount to the head page.  We have to be careful that the
1057                  * THP doesn't start to split while we are adjusting the
1058                  * refcounts.
1059                  *
1060                  * We are sure this doesn't happen, because mmu_notifier_retry
1061                  * was successful and we are holding the mmu_lock, so if this
1062                  * THP is trying to split, it will be blocked in the mmu
1063                  * notifier before touching any of the pages, specifically
1064                  * before being able to call __split_huge_page_refcount().
1065                  *
1066                  * We can therefore safely transfer the refcount from PG_tail
1067                  * to PG_head and switch the pfn from a tail page to the head
1068                  * page accordingly.
1069                  */
1070                 mask = PTRS_PER_PMD - 1;
1071                 VM_BUG_ON((gfn & mask) != (pfn & mask));
1072                 if (pfn & mask) {
1073                         *ipap &= PMD_MASK;
1074                         kvm_release_pfn_clean(pfn);
1075                         pfn &= ~mask;
1076                         kvm_get_pfn(pfn);
1077                         *pfnp = pfn;
1078                 }
1079
1080                 return true;
1081         }
1082
1083         return false;
1084 }
1085
1086 static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
1087 {
1088         if (kvm_vcpu_trap_is_iabt(vcpu))
1089                 return false;
1090
1091         return kvm_vcpu_dabt_iswrite(vcpu);
1092 }
1093
1094 /**
1095  * stage2_wp_ptes - write protect PMD range
1096  * @pmd:        pointer to pmd entry
1097  * @addr:       range start address
1098  * @end:        range end address
1099  */
1100 static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
1101 {
1102         pte_t *pte;
1103
1104         pte = pte_offset_kernel(pmd, addr);
1105         do {
1106                 if (!pte_none(*pte)) {
1107                         if (!kvm_s2pte_readonly(pte))
1108                                 kvm_set_s2pte_readonly(pte);
1109                 }
1110         } while (pte++, addr += PAGE_SIZE, addr != end);
1111 }
1112
1113 /**
1114  * stage2_wp_pmds - write protect PUD range
1115  * @pud:        pointer to pud entry
1116  * @addr:       range start address
1117  * @end:        range end address
1118  */
1119 static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
1120 {
1121         pmd_t *pmd;
1122         phys_addr_t next;
1123
1124         pmd = stage2_pmd_offset(pud, addr);
1125
1126         do {
1127                 next = stage2_pmd_addr_end(addr, end);
1128                 if (!pmd_none(*pmd)) {
1129                         if (pmd_thp_or_huge(*pmd)) {
1130                                 if (!kvm_s2pmd_readonly(pmd))
1131                                         kvm_set_s2pmd_readonly(pmd);
1132                         } else {
1133                                 stage2_wp_ptes(pmd, addr, next);
1134                         }
1135                 }
1136         } while (pmd++, addr = next, addr != end);
1137 }
1138
1139 /**
1140   * stage2_wp_puds - write protect PGD range
1141   * @pgd:       pointer to pgd entry
1142   * @addr:      range start address
1143   * @end:       range end address
1144   *
1145   * Process PUD entries, for a huge PUD we cause a panic.
1146   */
1147 static void  stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
1148 {
1149         pud_t *pud;
1150         phys_addr_t next;
1151
1152         pud = stage2_pud_offset(pgd, addr);
1153         do {
1154                 next = stage2_pud_addr_end(addr, end);
1155                 if (!stage2_pud_none(*pud)) {
1156                         /* TODO:PUD not supported, revisit later if supported */
1157                         BUG_ON(stage2_pud_huge(*pud));
1158                         stage2_wp_pmds(pud, addr, next);
1159                 }
1160         } while (pud++, addr = next, addr != end);
1161 }
1162
1163 /**
1164  * stage2_wp_range() - write protect stage2 memory region range
1165  * @kvm:        The KVM pointer
1166  * @addr:       Start address of range
1167  * @end:        End address of range
1168  */
1169 static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
1170 {
1171         pgd_t *pgd;
1172         phys_addr_t next;
1173
1174         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
1175         do {
1176                 /*
1177                  * Release kvm_mmu_lock periodically if the memory region is
1178                  * large. Otherwise, we may see kernel panics with
1179                  * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
1180                  * CONFIG_LOCKDEP. Additionally, holding the lock too long
1181                  * will also starve other vCPUs.
1182                  */
1183                 if (need_resched() || spin_needbreak(&kvm->mmu_lock))
1184                         cond_resched_lock(&kvm->mmu_lock);
1185
1186                 next = stage2_pgd_addr_end(addr, end);
1187                 if (stage2_pgd_present(*pgd))
1188                         stage2_wp_puds(pgd, addr, next);
1189         } while (pgd++, addr = next, addr != end);
1190 }
1191
1192 /**
1193  * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1194  * @kvm:        The KVM pointer
1195  * @slot:       The memory slot to write protect
1196  *
1197  * Called to start logging dirty pages after memory region
1198  * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1199  * all present PMD and PTEs are write protected in the memory region.
1200  * Afterwards read of dirty page log can be called.
1201  *
1202  * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1203  * serializing operations for VM memory regions.
1204  */
1205 void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
1206 {
1207         struct kvm_memslots *slots = kvm_memslots(kvm);
1208         struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1209         phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
1210         phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
1211
1212         spin_lock(&kvm->mmu_lock);
1213         stage2_wp_range(kvm, start, end);
1214         spin_unlock(&kvm->mmu_lock);
1215         kvm_flush_remote_tlbs(kvm);
1216 }
1217
1218 /**
1219  * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1220  * @kvm:        The KVM pointer
1221  * @slot:       The memory slot associated with mask
1222  * @gfn_offset: The gfn offset in memory slot
1223  * @mask:       The mask of dirty pages at offset 'gfn_offset' in this memory
1224  *              slot to be write protected
1225  *
1226  * Walks bits set in mask write protects the associated pte's. Caller must
1227  * acquire kvm_mmu_lock.
1228  */
1229 static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
1230                 struct kvm_memory_slot *slot,
1231                 gfn_t gfn_offset, unsigned long mask)
1232 {
1233         phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
1234         phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
1235         phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
1236
1237         stage2_wp_range(kvm, start, end);
1238 }
1239
1240 /*
1241  * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
1242  * dirty pages.
1243  *
1244  * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
1245  * enable dirty logging for them.
1246  */
1247 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
1248                 struct kvm_memory_slot *slot,
1249                 gfn_t gfn_offset, unsigned long mask)
1250 {
1251         kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
1252 }
1253
1254 static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
1255                                       unsigned long size, bool uncached)
1256 {
1257         __coherent_cache_guest_page(vcpu, pfn, size, uncached);
1258 }
1259
1260 static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1261                           struct kvm_memory_slot *memslot, unsigned long hva,
1262                           unsigned long fault_status)
1263 {
1264         int ret;
1265         bool write_fault, writable, hugetlb = false, force_pte = false;
1266         unsigned long mmu_seq;
1267         gfn_t gfn = fault_ipa >> PAGE_SHIFT;
1268         struct kvm *kvm = vcpu->kvm;
1269         struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1270         struct vm_area_struct *vma;
1271         kvm_pfn_t pfn;
1272         pgprot_t mem_type = PAGE_S2;
1273         bool fault_ipa_uncached;
1274         bool logging_active = memslot_is_logging(memslot);
1275         unsigned long flags = 0;
1276
1277         write_fault = kvm_is_write_fault(vcpu);
1278         if (fault_status == FSC_PERM && !write_fault) {
1279                 kvm_err("Unexpected L2 read permission error\n");
1280                 return -EFAULT;
1281         }
1282
1283         /* Let's check if we will get back a huge page backed by hugetlbfs */
1284         down_read(&current->mm->mmap_sem);
1285         vma = find_vma_intersection(current->mm, hva, hva + 1);
1286         if (unlikely(!vma)) {
1287                 kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
1288                 up_read(&current->mm->mmap_sem);
1289                 return -EFAULT;
1290         }
1291
1292         if (is_vm_hugetlb_page(vma) && !logging_active) {
1293                 hugetlb = true;
1294                 gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
1295         } else {
1296                 /*
1297                  * Pages belonging to memslots that don't have the same
1298                  * alignment for userspace and IPA cannot be mapped using
1299                  * block descriptors even if the pages belong to a THP for
1300                  * the process, because the stage-2 block descriptor will
1301                  * cover more than a single THP and we loose atomicity for
1302                  * unmapping, updates, and splits of the THP or other pages
1303                  * in the stage-2 block range.
1304                  */
1305                 if ((memslot->userspace_addr & ~PMD_MASK) !=
1306                     ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
1307                         force_pte = true;
1308         }
1309         up_read(&current->mm->mmap_sem);
1310
1311         /* We need minimum second+third level pages */
1312         ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
1313                                      KVM_NR_MEM_OBJS);
1314         if (ret)
1315                 return ret;
1316
1317         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1318         /*
1319          * Ensure the read of mmu_notifier_seq happens before we call
1320          * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1321          * the page we just got a reference to gets unmapped before we have a
1322          * chance to grab the mmu_lock, which ensure that if the page gets
1323          * unmapped afterwards, the call to kvm_unmap_hva will take it away
1324          * from us again properly. This smp_rmb() interacts with the smp_wmb()
1325          * in kvm_mmu_notifier_invalidate_<page|range_end>.
1326          */
1327         smp_rmb();
1328
1329         pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
1330         if (is_error_pfn(pfn))
1331                 return -EFAULT;
1332
1333         if (kvm_is_device_pfn(pfn)) {
1334                 mem_type = PAGE_S2_DEVICE;
1335                 flags |= KVM_S2PTE_FLAG_IS_IOMAP;
1336         } else if (logging_active) {
1337                 /*
1338                  * Faults on pages in a memslot with logging enabled
1339                  * should not be mapped with huge pages (it introduces churn
1340                  * and performance degradation), so force a pte mapping.
1341                  */
1342                 force_pte = true;
1343                 flags |= KVM_S2_FLAG_LOGGING_ACTIVE;
1344
1345                 /*
1346                  * Only actually map the page as writable if this was a write
1347                  * fault.
1348                  */
1349                 if (!write_fault)
1350                         writable = false;
1351         }
1352
1353         spin_lock(&kvm->mmu_lock);
1354         if (mmu_notifier_retry(kvm, mmu_seq))
1355                 goto out_unlock;
1356
1357         if (!hugetlb && !force_pte)
1358                 hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
1359
1360         fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT;
1361
1362         if (hugetlb) {
1363                 pmd_t new_pmd = pfn_pmd(pfn, mem_type);
1364                 new_pmd = pmd_mkhuge(new_pmd);
1365                 if (writable) {
1366                         new_pmd = kvm_s2pmd_mkwrite(new_pmd);
1367                         kvm_set_pfn_dirty(pfn);
1368                 }
1369                 coherent_cache_guest_page(vcpu, pfn, PMD_SIZE, fault_ipa_uncached);
1370                 ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
1371         } else {
1372                 pte_t new_pte = pfn_pte(pfn, mem_type);
1373
1374                 if (writable) {
1375                         new_pte = kvm_s2pte_mkwrite(new_pte);
1376                         kvm_set_pfn_dirty(pfn);
1377                         mark_page_dirty(kvm, gfn);
1378                 }
1379                 coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE, fault_ipa_uncached);
1380                 ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
1381         }
1382
1383 out_unlock:
1384         spin_unlock(&kvm->mmu_lock);
1385         kvm_set_pfn_accessed(pfn);
1386         kvm_release_pfn_clean(pfn);
1387         return ret;
1388 }
1389
1390 /*
1391  * Resolve the access fault by making the page young again.
1392  * Note that because the faulting entry is guaranteed not to be
1393  * cached in the TLB, we don't need to invalidate anything.
1394  * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
1395  * so there is no need for atomic (pte|pmd)_mkyoung operations.
1396  */
1397 static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
1398 {
1399         pmd_t *pmd;
1400         pte_t *pte;
1401         kvm_pfn_t pfn;
1402         bool pfn_valid = false;
1403
1404         trace_kvm_access_fault(fault_ipa);
1405
1406         spin_lock(&vcpu->kvm->mmu_lock);
1407
1408         pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
1409         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1410                 goto out;
1411
1412         if (pmd_thp_or_huge(*pmd)) {    /* THP, HugeTLB */
1413                 *pmd = pmd_mkyoung(*pmd);
1414                 pfn = pmd_pfn(*pmd);
1415                 pfn_valid = true;
1416                 goto out;
1417         }
1418
1419         pte = pte_offset_kernel(pmd, fault_ipa);
1420         if (pte_none(*pte))             /* Nothing there either */
1421                 goto out;
1422
1423         *pte = pte_mkyoung(*pte);       /* Just a page... */
1424         pfn = pte_pfn(*pte);
1425         pfn_valid = true;
1426 out:
1427         spin_unlock(&vcpu->kvm->mmu_lock);
1428         if (pfn_valid)
1429                 kvm_set_pfn_accessed(pfn);
1430 }
1431
1432 /**
1433  * kvm_handle_guest_abort - handles all 2nd stage aborts
1434  * @vcpu:       the VCPU pointer
1435  * @run:        the kvm_run structure
1436  *
1437  * Any abort that gets to the host is almost guaranteed to be caused by a
1438  * missing second stage translation table entry, which can mean that either the
1439  * guest simply needs more memory and we must allocate an appropriate page or it
1440  * can mean that the guest tried to access I/O memory, which is emulated by user
1441  * space. The distinction is based on the IPA causing the fault and whether this
1442  * memory region has been registered as standard RAM by user space.
1443  */
1444 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
1445 {
1446         unsigned long fault_status;
1447         phys_addr_t fault_ipa;
1448         struct kvm_memory_slot *memslot;
1449         unsigned long hva;
1450         bool is_iabt, write_fault, writable;
1451         gfn_t gfn;
1452         int ret, idx;
1453
1454         is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1455         fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
1456
1457         trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
1458                               kvm_vcpu_get_hfar(vcpu), fault_ipa);
1459
1460         /* Check the stage-2 fault is trans. fault or write fault */
1461         fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
1462         if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
1463             fault_status != FSC_ACCESS) {
1464                 kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1465                         kvm_vcpu_trap_get_class(vcpu),
1466                         (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
1467                         (unsigned long)kvm_vcpu_get_hsr(vcpu));
1468                 return -EFAULT;
1469         }
1470
1471         idx = srcu_read_lock(&vcpu->kvm->srcu);
1472
1473         gfn = fault_ipa >> PAGE_SHIFT;
1474         memslot = gfn_to_memslot(vcpu->kvm, gfn);
1475         hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1476         write_fault = kvm_is_write_fault(vcpu);
1477         if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1478                 if (is_iabt) {
1479                         /* Prefetch Abort on I/O address */
1480                         kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1481                         ret = 1;
1482                         goto out_unlock;
1483                 }
1484
1485                 /*
1486                  * Check for a cache maintenance operation. Since we
1487                  * ended-up here, we know it is outside of any memory
1488                  * slot. But we can't find out if that is for a device,
1489                  * or if the guest is just being stupid. The only thing
1490                  * we know for sure is that this range cannot be cached.
1491                  *
1492                  * So let's assume that the guest is just being
1493                  * cautious, and skip the instruction.
1494                  */
1495                 if (kvm_vcpu_dabt_is_cm(vcpu)) {
1496                         kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
1497                         ret = 1;
1498                         goto out_unlock;
1499                 }
1500
1501                 /*
1502                  * The IPA is reported as [MAX:12], so we need to
1503                  * complement it with the bottom 12 bits from the
1504                  * faulting VA. This is always 12 bits, irrespective
1505                  * of the page size.
1506                  */
1507                 fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
1508                 ret = io_mem_abort(vcpu, run, fault_ipa);
1509                 goto out_unlock;
1510         }
1511
1512         /* Userspace should not be able to register out-of-bounds IPAs */
1513         VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
1514
1515         if (fault_status == FSC_ACCESS) {
1516                 handle_access_fault(vcpu, fault_ipa);
1517                 ret = 1;
1518                 goto out_unlock;
1519         }
1520
1521         ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1522         if (ret == 0)
1523                 ret = 1;
1524 out_unlock:
1525         srcu_read_unlock(&vcpu->kvm->srcu, idx);
1526         return ret;
1527 }
1528
1529 static int handle_hva_to_gpa(struct kvm *kvm,
1530                              unsigned long start,
1531                              unsigned long end,
1532                              int (*handler)(struct kvm *kvm,
1533                                             gpa_t gpa, void *data),
1534                              void *data)
1535 {
1536         struct kvm_memslots *slots;
1537         struct kvm_memory_slot *memslot;
1538         int ret = 0;
1539
1540         slots = kvm_memslots(kvm);
1541
1542         /* we only care about the pages that the guest sees */
1543         kvm_for_each_memslot(memslot, slots) {
1544                 unsigned long hva_start, hva_end;
1545                 gfn_t gfn, gfn_end;
1546
1547                 hva_start = max(start, memslot->userspace_addr);
1548                 hva_end = min(end, memslot->userspace_addr +
1549                                         (memslot->npages << PAGE_SHIFT));
1550                 if (hva_start >= hva_end)
1551                         continue;
1552
1553                 /*
1554                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
1555                  * {gfn_start, gfn_start+1, ..., gfn_end-1}.
1556                  */
1557                 gfn = hva_to_gfn_memslot(hva_start, memslot);
1558                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
1559
1560                 for (; gfn < gfn_end; ++gfn) {
1561                         gpa_t gpa = gfn << PAGE_SHIFT;
1562                         ret |= handler(kvm, gpa, data);
1563                 }
1564         }
1565
1566         return ret;
1567 }
1568
1569 static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1570 {
1571         unmap_stage2_range(kvm, gpa, PAGE_SIZE);
1572         return 0;
1573 }
1574
1575 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
1576 {
1577         unsigned long end = hva + PAGE_SIZE;
1578
1579         if (!kvm->arch.pgd)
1580                 return 0;
1581
1582         trace_kvm_unmap_hva(hva);
1583         handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
1584         return 0;
1585 }
1586
1587 int kvm_unmap_hva_range(struct kvm *kvm,
1588                         unsigned long start, unsigned long end)
1589 {
1590         if (!kvm->arch.pgd)
1591                 return 0;
1592
1593         trace_kvm_unmap_hva_range(start, end);
1594         handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
1595         return 0;
1596 }
1597
1598 static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, void *data)
1599 {
1600         pte_t *pte = (pte_t *)data;
1601
1602         /*
1603          * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
1604          * flag clear because MMU notifiers will have unmapped a huge PMD before
1605          * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
1606          * therefore stage2_set_pte() never needs to clear out a huge PMD
1607          * through this calling path.
1608          */
1609         stage2_set_pte(kvm, NULL, gpa, pte, 0);
1610         return 0;
1611 }
1612
1613
1614 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
1615 {
1616         unsigned long end = hva + PAGE_SIZE;
1617         pte_t stage2_pte;
1618
1619         if (!kvm->arch.pgd)
1620                 return;
1621
1622         trace_kvm_set_spte_hva(hva);
1623         stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
1624         handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
1625 }
1626
1627 static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1628 {
1629         pmd_t *pmd;
1630         pte_t *pte;
1631
1632         pmd = stage2_get_pmd(kvm, NULL, gpa);
1633         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1634                 return 0;
1635
1636         if (pmd_thp_or_huge(*pmd))      /* THP, HugeTLB */
1637                 return stage2_pmdp_test_and_clear_young(pmd);
1638
1639         pte = pte_offset_kernel(pmd, gpa);
1640         if (pte_none(*pte))
1641                 return 0;
1642
1643         return stage2_ptep_test_and_clear_young(pte);
1644 }
1645
1646 static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1647 {
1648         pmd_t *pmd;
1649         pte_t *pte;
1650
1651         pmd = stage2_get_pmd(kvm, NULL, gpa);
1652         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1653                 return 0;
1654
1655         if (pmd_thp_or_huge(*pmd))              /* THP, HugeTLB */
1656                 return pmd_young(*pmd);
1657
1658         pte = pte_offset_kernel(pmd, gpa);
1659         if (!pte_none(*pte))            /* Just a page... */
1660                 return pte_young(*pte);
1661
1662         return 0;
1663 }
1664
1665 int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
1666 {
1667         trace_kvm_age_hva(start, end);
1668         return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
1669 }
1670
1671 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
1672 {
1673         trace_kvm_test_age_hva(hva);
1674         return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
1675 }
1676
1677 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
1678 {
1679         mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
1680 }
1681
1682 phys_addr_t kvm_mmu_get_httbr(void)
1683 {
1684         if (__kvm_cpu_uses_extended_idmap())
1685                 return virt_to_phys(merged_hyp_pgd);
1686         else
1687                 return virt_to_phys(hyp_pgd);
1688 }
1689
1690 phys_addr_t kvm_mmu_get_boot_httbr(void)
1691 {
1692         if (__kvm_cpu_uses_extended_idmap())
1693                 return virt_to_phys(merged_hyp_pgd);
1694         else
1695                 return virt_to_phys(boot_hyp_pgd);
1696 }
1697
1698 phys_addr_t kvm_get_idmap_vector(void)
1699 {
1700         return hyp_idmap_vector;
1701 }
1702
1703 phys_addr_t kvm_get_idmap_start(void)
1704 {
1705         return hyp_idmap_start;
1706 }
1707
1708 int kvm_mmu_init(void)
1709 {
1710         int err;
1711
1712         hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
1713         hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
1714         hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
1715
1716         /*
1717          * We rely on the linker script to ensure at build time that the HYP
1718          * init code does not cross a page boundary.
1719          */
1720         BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
1721
1722         hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1723         boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1724
1725         if (!hyp_pgd || !boot_hyp_pgd) {
1726                 kvm_err("Hyp mode PGD not allocated\n");
1727                 err = -ENOMEM;
1728                 goto out;
1729         }
1730
1731         /* Create the idmap in the boot page tables */
1732         err =   __create_hyp_mappings(boot_hyp_pgd,
1733                                       hyp_idmap_start, hyp_idmap_end,
1734                                       __phys_to_pfn(hyp_idmap_start),
1735                                       PAGE_HYP);
1736
1737         if (err) {
1738                 kvm_err("Failed to idmap %lx-%lx\n",
1739                         hyp_idmap_start, hyp_idmap_end);
1740                 goto out;
1741         }
1742
1743         if (__kvm_cpu_uses_extended_idmap()) {
1744                 merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
1745                 if (!merged_hyp_pgd) {
1746                         kvm_err("Failed to allocate extra HYP pgd\n");
1747                         goto out;
1748                 }
1749                 __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd,
1750                                     hyp_idmap_start);
1751                 return 0;
1752         }
1753
1754         /* Map the very same page at the trampoline VA */
1755         err =   __create_hyp_mappings(boot_hyp_pgd,
1756                                       TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
1757                                       __phys_to_pfn(hyp_idmap_start),
1758                                       PAGE_HYP);
1759         if (err) {
1760                 kvm_err("Failed to map trampoline @%lx into boot HYP pgd\n",
1761                         TRAMPOLINE_VA);
1762                 goto out;
1763         }
1764
1765         /* Map the same page again into the runtime page tables */
1766         err =   __create_hyp_mappings(hyp_pgd,
1767                                       TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
1768                                       __phys_to_pfn(hyp_idmap_start),
1769                                       PAGE_HYP);
1770         if (err) {
1771                 kvm_err("Failed to map trampoline @%lx into runtime HYP pgd\n",
1772                         TRAMPOLINE_VA);
1773                 goto out;
1774         }
1775
1776         return 0;
1777 out:
1778         free_hyp_pgds();
1779         return err;
1780 }
1781
1782 void kvm_arch_commit_memory_region(struct kvm *kvm,
1783                                    const struct kvm_userspace_memory_region *mem,
1784                                    const struct kvm_memory_slot *old,
1785                                    const struct kvm_memory_slot *new,
1786                                    enum kvm_mr_change change)
1787 {
1788         /*
1789          * At this point memslot has been committed and there is an
1790          * allocated dirty_bitmap[], dirty pages will be be tracked while the
1791          * memory slot is write protected.
1792          */
1793         if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES)
1794                 kvm_mmu_wp_memory_region(kvm, mem->slot);
1795 }
1796
1797 int kvm_arch_prepare_memory_region(struct kvm *kvm,
1798                                    struct kvm_memory_slot *memslot,
1799                                    const struct kvm_userspace_memory_region *mem,
1800                                    enum kvm_mr_change change)
1801 {
1802         hva_t hva = mem->userspace_addr;
1803         hva_t reg_end = hva + mem->memory_size;
1804         bool writable = !(mem->flags & KVM_MEM_READONLY);
1805         int ret = 0;
1806
1807         if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
1808                         change != KVM_MR_FLAGS_ONLY)
1809                 return 0;
1810
1811         /*
1812          * Prevent userspace from creating a memory region outside of the IPA
1813          * space addressable by the KVM guest IPA space.
1814          */
1815         if (memslot->base_gfn + memslot->npages >=
1816             (KVM_PHYS_SIZE >> PAGE_SHIFT))
1817                 return -EFAULT;
1818
1819         /*
1820          * A memory region could potentially cover multiple VMAs, and any holes
1821          * between them, so iterate over all of them to find out if we can map
1822          * any of them right now.
1823          *
1824          *     +--------------------------------------------+
1825          * +---------------+----------------+   +----------------+
1826          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
1827          * +---------------+----------------+   +----------------+
1828          *     |               memory region                |
1829          *     +--------------------------------------------+
1830          */
1831         do {
1832                 struct vm_area_struct *vma = find_vma(current->mm, hva);
1833                 hva_t vm_start, vm_end;
1834
1835                 if (!vma || vma->vm_start >= reg_end)
1836                         break;
1837
1838                 /*
1839                  * Mapping a read-only VMA is only allowed if the
1840                  * memory region is configured as read-only.
1841                  */
1842                 if (writable && !(vma->vm_flags & VM_WRITE)) {
1843                         ret = -EPERM;
1844                         break;
1845                 }
1846
1847                 /*
1848                  * Take the intersection of this VMA with the memory region
1849                  */
1850                 vm_start = max(hva, vma->vm_start);
1851                 vm_end = min(reg_end, vma->vm_end);
1852
1853                 if (vma->vm_flags & VM_PFNMAP) {
1854                         gpa_t gpa = mem->guest_phys_addr +
1855                                     (vm_start - mem->userspace_addr);
1856                         phys_addr_t pa;
1857
1858                         pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
1859                         pa += vm_start - vma->vm_start;
1860
1861                         /* IO region dirty page logging not allowed */
1862                         if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES)
1863                                 return -EINVAL;
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                 return ret;
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         return ret;
1884 }
1885
1886 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
1887                            struct kvm_memory_slot *dont)
1888 {
1889 }
1890
1891 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
1892                             unsigned long npages)
1893 {
1894         /*
1895          * Readonly memslots are not incoherent with the caches by definition,
1896          * but in practice, they are used mostly to emulate ROMs or NOR flashes
1897          * that the guest may consider devices and hence map as uncached.
1898          * To prevent incoherency issues in these cases, tag all readonly
1899          * regions as incoherent.
1900          */
1901         if (slot->flags & KVM_MEM_READONLY)
1902                 slot->flags |= KVM_MEMSLOT_INCOHERENT;
1903         return 0;
1904 }
1905
1906 void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
1907 {
1908 }
1909
1910 void kvm_arch_flush_shadow_all(struct kvm *kvm)
1911 {
1912 }
1913
1914 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
1915                                    struct kvm_memory_slot *slot)
1916 {
1917         gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
1918         phys_addr_t size = slot->npages << PAGE_SHIFT;
1919
1920         spin_lock(&kvm->mmu_lock);
1921         unmap_stage2_range(kvm, gpa, size);
1922         spin_unlock(&kvm->mmu_lock);
1923 }
1924
1925 /*
1926  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1927  *
1928  * Main problems:
1929  * - S/W ops are local to a CPU (not broadcast)
1930  * - We have line migration behind our back (speculation)
1931  * - System caches don't support S/W at all (damn!)
1932  *
1933  * In the face of the above, the best we can do is to try and convert
1934  * S/W ops to VA ops. Because the guest is not allowed to infer the
1935  * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1936  * which is a rather good thing for us.
1937  *
1938  * Also, it is only used when turning caches on/off ("The expected
1939  * usage of the cache maintenance instructions that operate by set/way
1940  * is associated with the cache maintenance instructions associated
1941  * with the powerdown and powerup of caches, if this is required by
1942  * the implementation.").
1943  *
1944  * We use the following policy:
1945  *
1946  * - If we trap a S/W operation, we enable VM trapping to detect
1947  *   caches being turned on/off, and do a full clean.
1948  *
1949  * - We flush the caches on both caches being turned on and off.
1950  *
1951  * - Once the caches are enabled, we stop trapping VM ops.
1952  */
1953 void kvm_set_way_flush(struct kvm_vcpu *vcpu)
1954 {
1955         unsigned long hcr = vcpu_get_hcr(vcpu);
1956
1957         /*
1958          * If this is the first time we do a S/W operation
1959          * (i.e. HCR_TVM not set) flush the whole memory, and set the
1960          * VM trapping.
1961          *
1962          * Otherwise, rely on the VM trapping to wait for the MMU +
1963          * Caches to be turned off. At that point, we'll be able to
1964          * clean the caches again.
1965          */
1966         if (!(hcr & HCR_TVM)) {
1967                 trace_kvm_set_way_flush(*vcpu_pc(vcpu),
1968                                         vcpu_has_cache_enabled(vcpu));
1969                 stage2_flush_vm(vcpu->kvm);
1970                 vcpu_set_hcr(vcpu, hcr | HCR_TVM);
1971         }
1972 }
1973
1974 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
1975 {
1976         bool now_enabled = vcpu_has_cache_enabled(vcpu);
1977
1978         /*
1979          * If switching the MMU+caches on, need to invalidate the caches.
1980          * If switching it off, need to clean the caches.
1981          * Clean + invalidate does the trick always.
1982          */
1983         if (now_enabled != was_enabled)
1984                 stage2_flush_vm(vcpu->kvm);
1985
1986         /* Caches are now on, stop trapping VM ops (until a S/W op) */
1987         if (now_enabled)
1988                 vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);
1989
1990         trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
1991 }