| 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * Copyright (C) 2012 - Virtual Open Systems and Columbia University |
| 4 | * Author: Christoffer Dall <c.dall@virtualopensystems.com> |
| 5 | */ |
| 6 | |
| 7 | #include <linux/mman.h> |
| 8 | #include <linux/kvm_host.h> |
| 9 | #include <linux/io.h> |
| 10 | #include <linux/hugetlb.h> |
| 11 | #include <linux/sched/signal.h> |
| 12 | #include <trace/events/kvm.h> |
| 13 | #include <asm/pgalloc.h> |
| 14 | #include <asm/cacheflush.h> |
| 15 | #include <asm/kvm_arm.h> |
| 16 | #include <asm/kvm_mmu.h> |
| 17 | #include <asm/kvm_pgtable.h> |
| 18 | #include <asm/kvm_ras.h> |
| 19 | #include <asm/kvm_asm.h> |
| 20 | #include <asm/kvm_emulate.h> |
| 21 | #include <asm/virt.h> |
| 22 | |
| 23 | #include "trace.h" |
| 24 | |
| 25 | static struct kvm_pgtable *hyp_pgtable; |
| 26 | static DEFINE_MUTEX(kvm_hyp_pgd_mutex); |
| 27 | |
| 28 | static unsigned long __ro_after_init hyp_idmap_start; |
| 29 | static unsigned long __ro_after_init hyp_idmap_end; |
| 30 | static phys_addr_t __ro_after_init hyp_idmap_vector; |
| 31 | |
| 32 | static unsigned long __ro_after_init io_map_base; |
| 33 | |
| 34 | static phys_addr_t __stage2_range_addr_end(phys_addr_t addr, phys_addr_t end, |
| 35 | phys_addr_t size) |
| 36 | { |
| 37 | phys_addr_t boundary = ALIGN_DOWN(addr + size, size); |
| 38 | |
| 39 | return (boundary - 1 < end - 1) ? boundary : end; |
| 40 | } |
| 41 | |
| 42 | static phys_addr_t stage2_range_addr_end(phys_addr_t addr, phys_addr_t end) |
| 43 | { |
| 44 | phys_addr_t size = kvm_granule_size(KVM_PGTABLE_MIN_BLOCK_LEVEL); |
| 45 | |
| 46 | return __stage2_range_addr_end(addr, end, size); |
| 47 | } |
| 48 | |
| 49 | /* |
| 50 | * Release kvm_mmu_lock periodically if the memory region is large. Otherwise, |
| 51 | * we may see kernel panics with CONFIG_DETECT_HUNG_TASK, |
| 52 | * CONFIG_LOCKUP_DETECTOR, CONFIG_LOCKDEP. Additionally, holding the lock too |
| 53 | * long will also starve other vCPUs. We have to also make sure that the page |
| 54 | * tables are not freed while we released the lock. |
| 55 | */ |
| 56 | static int stage2_apply_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, |
| 57 | phys_addr_t end, |
| 58 | int (*fn)(struct kvm_pgtable *, u64, u64), |
| 59 | bool resched) |
| 60 | { |
| 61 | struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); |
| 62 | int ret; |
| 63 | u64 next; |
| 64 | |
| 65 | do { |
| 66 | struct kvm_pgtable *pgt = mmu->pgt; |
| 67 | if (!pgt) |
| 68 | return -EINVAL; |
| 69 | |
| 70 | next = stage2_range_addr_end(addr, end); |
| 71 | ret = fn(pgt, addr, next - addr); |
| 72 | if (ret) |
| 73 | break; |
| 74 | |
| 75 | if (resched && next != end) |
| 76 | cond_resched_rwlock_write(&kvm->mmu_lock); |
| 77 | } while (addr = next, addr != end); |
| 78 | |
| 79 | return ret; |
| 80 | } |
| 81 | |
| 82 | #define stage2_apply_range_resched(mmu, addr, end, fn) \ |
| 83 | stage2_apply_range(mmu, addr, end, fn, true) |
| 84 | |
| 85 | /* |
| 86 | * Get the maximum number of page-tables pages needed to split a range |
| 87 | * of blocks into PAGE_SIZE PTEs. It assumes the range is already |
| 88 | * mapped at level 2, or at level 1 if allowed. |
| 89 | */ |
| 90 | static int kvm_mmu_split_nr_page_tables(u64 range) |
| 91 | { |
| 92 | int n = 0; |
| 93 | |
| 94 | if (KVM_PGTABLE_MIN_BLOCK_LEVEL < 2) |
| 95 | n += DIV_ROUND_UP(range, PUD_SIZE); |
| 96 | n += DIV_ROUND_UP(range, PMD_SIZE); |
| 97 | return n; |
| 98 | } |
| 99 | |
| 100 | static bool need_split_memcache_topup_or_resched(struct kvm *kvm) |
| 101 | { |
| 102 | struct kvm_mmu_memory_cache *cache; |
| 103 | u64 chunk_size, min; |
| 104 | |
| 105 | if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) |
| 106 | return true; |
| 107 | |
| 108 | chunk_size = kvm->arch.mmu.split_page_chunk_size; |
| 109 | min = kvm_mmu_split_nr_page_tables(chunk_size); |
| 110 | cache = &kvm->arch.mmu.split_page_cache; |
| 111 | return kvm_mmu_memory_cache_nr_free_objects(cache) < min; |
| 112 | } |
| 113 | |
| 114 | static int kvm_mmu_split_huge_pages(struct kvm *kvm, phys_addr_t addr, |
| 115 | phys_addr_t end) |
| 116 | { |
| 117 | struct kvm_mmu_memory_cache *cache; |
| 118 | struct kvm_pgtable *pgt; |
| 119 | int ret, cache_capacity; |
| 120 | u64 next, chunk_size; |
| 121 | |
| 122 | lockdep_assert_held_write(&kvm->mmu_lock); |
| 123 | |
| 124 | chunk_size = kvm->arch.mmu.split_page_chunk_size; |
| 125 | cache_capacity = kvm_mmu_split_nr_page_tables(chunk_size); |
| 126 | |
| 127 | if (chunk_size == 0) |
| 128 | return 0; |
| 129 | |
| 130 | cache = &kvm->arch.mmu.split_page_cache; |
| 131 | |
| 132 | do { |
| 133 | if (need_split_memcache_topup_or_resched(kvm)) { |
| 134 | write_unlock(&kvm->mmu_lock); |
| 135 | cond_resched(); |
| 136 | /* Eager page splitting is best-effort. */ |
| 137 | ret = __kvm_mmu_topup_memory_cache(cache, |
| 138 | cache_capacity, |
| 139 | cache_capacity); |
| 140 | write_lock(&kvm->mmu_lock); |
| 141 | if (ret) |
| 142 | break; |
| 143 | } |
| 144 | |
| 145 | pgt = kvm->arch.mmu.pgt; |
| 146 | if (!pgt) |
| 147 | return -EINVAL; |
| 148 | |
| 149 | next = __stage2_range_addr_end(addr, end, chunk_size); |
| 150 | ret = kvm_pgtable_stage2_split(pgt, addr, next - addr, cache); |
| 151 | if (ret) |
| 152 | break; |
| 153 | } while (addr = next, addr != end); |
| 154 | |
| 155 | return ret; |
| 156 | } |
| 157 | |
| 158 | static bool memslot_is_logging(struct kvm_memory_slot *memslot) |
| 159 | { |
| 160 | return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY); |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * kvm_arch_flush_remote_tlbs() - flush all VM TLB entries for v7/8 |
| 165 | * @kvm: pointer to kvm structure. |
| 166 | * |
| 167 | * Interface to HYP function to flush all VM TLB entries |
| 168 | */ |
| 169 | int kvm_arch_flush_remote_tlbs(struct kvm *kvm) |
| 170 | { |
| 171 | kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu); |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, |
| 176 | gfn_t gfn, u64 nr_pages) |
| 177 | { |
| 178 | kvm_tlb_flush_vmid_range(&kvm->arch.mmu, |
| 179 | gfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | static bool kvm_is_device_pfn(unsigned long pfn) |
| 184 | { |
| 185 | return !pfn_is_map_memory(pfn); |
| 186 | } |
| 187 | |
| 188 | static void *stage2_memcache_zalloc_page(void *arg) |
| 189 | { |
| 190 | struct kvm_mmu_memory_cache *mc = arg; |
| 191 | void *virt; |
| 192 | |
| 193 | /* Allocated with __GFP_ZERO, so no need to zero */ |
| 194 | virt = kvm_mmu_memory_cache_alloc(mc); |
| 195 | if (virt) |
| 196 | kvm_account_pgtable_pages(virt, 1); |
| 197 | return virt; |
| 198 | } |
| 199 | |
| 200 | static void *kvm_host_zalloc_pages_exact(size_t size) |
| 201 | { |
| 202 | return alloc_pages_exact(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO); |
| 203 | } |
| 204 | |
| 205 | static void *kvm_s2_zalloc_pages_exact(size_t size) |
| 206 | { |
| 207 | void *virt = kvm_host_zalloc_pages_exact(size); |
| 208 | |
| 209 | if (virt) |
| 210 | kvm_account_pgtable_pages(virt, (size >> PAGE_SHIFT)); |
| 211 | return virt; |
| 212 | } |
| 213 | |
| 214 | static void kvm_s2_free_pages_exact(void *virt, size_t size) |
| 215 | { |
| 216 | kvm_account_pgtable_pages(virt, -(size >> PAGE_SHIFT)); |
| 217 | free_pages_exact(virt, size); |
| 218 | } |
| 219 | |
| 220 | static struct kvm_pgtable_mm_ops kvm_s2_mm_ops; |
| 221 | |
| 222 | static void stage2_free_unlinked_table_rcu_cb(struct rcu_head *head) |
| 223 | { |
| 224 | struct page *page = container_of(head, struct page, rcu_head); |
| 225 | void *pgtable = page_to_virt(page); |
| 226 | s8 level = page_private(page); |
| 227 | |
| 228 | kvm_pgtable_stage2_free_unlinked(&kvm_s2_mm_ops, pgtable, level); |
| 229 | } |
| 230 | |
| 231 | static void stage2_free_unlinked_table(void *addr, s8 level) |
| 232 | { |
| 233 | struct page *page = virt_to_page(addr); |
| 234 | |
| 235 | set_page_private(page, (unsigned long)level); |
| 236 | call_rcu(&page->rcu_head, stage2_free_unlinked_table_rcu_cb); |
| 237 | } |
| 238 | |
| 239 | static void kvm_host_get_page(void *addr) |
| 240 | { |
| 241 | get_page(virt_to_page(addr)); |
| 242 | } |
| 243 | |
| 244 | static void kvm_host_put_page(void *addr) |
| 245 | { |
| 246 | put_page(virt_to_page(addr)); |
| 247 | } |
| 248 | |
| 249 | static void kvm_s2_put_page(void *addr) |
| 250 | { |
| 251 | struct page *p = virt_to_page(addr); |
| 252 | /* Dropping last refcount, the page will be freed */ |
| 253 | if (page_count(p) == 1) |
| 254 | kvm_account_pgtable_pages(addr, -1); |
| 255 | put_page(p); |
| 256 | } |
| 257 | |
| 258 | static int kvm_host_page_count(void *addr) |
| 259 | { |
| 260 | return page_count(virt_to_page(addr)); |
| 261 | } |
| 262 | |
| 263 | static phys_addr_t kvm_host_pa(void *addr) |
| 264 | { |
| 265 | return __pa(addr); |
| 266 | } |
| 267 | |
| 268 | static void *kvm_host_va(phys_addr_t phys) |
| 269 | { |
| 270 | return __va(phys); |
| 271 | } |
| 272 | |
| 273 | static void clean_dcache_guest_page(void *va, size_t size) |
| 274 | { |
| 275 | __clean_dcache_guest_page(va, size); |
| 276 | } |
| 277 | |
| 278 | static void invalidate_icache_guest_page(void *va, size_t size) |
| 279 | { |
| 280 | __invalidate_icache_guest_page(va, size); |
| 281 | } |
| 282 | |
| 283 | /* |
| 284 | * Unmapping vs dcache management: |
| 285 | * |
| 286 | * If a guest maps certain memory pages as uncached, all writes will |
| 287 | * bypass the data cache and go directly to RAM. However, the CPUs |
| 288 | * can still speculate reads (not writes) and fill cache lines with |
| 289 | * data. |
| 290 | * |
| 291 | * Those cache lines will be *clean* cache lines though, so a |
| 292 | * clean+invalidate operation is equivalent to an invalidate |
| 293 | * operation, because no cache lines are marked dirty. |
| 294 | * |
| 295 | * Those clean cache lines could be filled prior to an uncached write |
| 296 | * by the guest, and the cache coherent IO subsystem would therefore |
| 297 | * end up writing old data to disk. |
| 298 | * |
| 299 | * This is why right after unmapping a page/section and invalidating |
| 300 | * the corresponding TLBs, we flush to make sure the IO subsystem will |
| 301 | * never hit in the cache. |
| 302 | * |
| 303 | * This is all avoided on systems that have ARM64_HAS_STAGE2_FWB, as |
| 304 | * we then fully enforce cacheability of RAM, no matter what the guest |
| 305 | * does. |
| 306 | */ |
| 307 | /** |
| 308 | * __unmap_stage2_range -- Clear stage2 page table entries to unmap a range |
| 309 | * @mmu: The KVM stage-2 MMU pointer |
| 310 | * @start: The intermediate physical base address of the range to unmap |
| 311 | * @size: The size of the area to unmap |
| 312 | * @may_block: Whether or not we are permitted to block |
| 313 | * |
| 314 | * Clear a range of stage-2 mappings, lowering the various ref-counts. Must |
| 315 | * be called while holding mmu_lock (unless for freeing the stage2 pgd before |
| 316 | * destroying the VM), otherwise another faulting VCPU may come in and mess |
| 317 | * with things behind our backs. |
| 318 | */ |
| 319 | static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, |
| 320 | bool may_block) |
| 321 | { |
| 322 | struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); |
| 323 | phys_addr_t end = start + size; |
| 324 | |
| 325 | lockdep_assert_held_write(&kvm->mmu_lock); |
| 326 | WARN_ON(size & ~PAGE_MASK); |
| 327 | WARN_ON(stage2_apply_range(mmu, start, end, kvm_pgtable_stage2_unmap, |
| 328 | may_block)); |
| 329 | } |
| 330 | |
| 331 | static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) |
| 332 | { |
| 333 | __unmap_stage2_range(mmu, start, size, true); |
| 334 | } |
| 335 | |
| 336 | static void stage2_flush_memslot(struct kvm *kvm, |
| 337 | struct kvm_memory_slot *memslot) |
| 338 | { |
| 339 | phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; |
| 340 | phys_addr_t end = addr + PAGE_SIZE * memslot->npages; |
| 341 | |
| 342 | stage2_apply_range_resched(&kvm->arch.mmu, addr, end, kvm_pgtable_stage2_flush); |
| 343 | } |
| 344 | |
| 345 | /** |
| 346 | * stage2_flush_vm - Invalidate cache for pages mapped in stage 2 |
| 347 | * @kvm: The struct kvm pointer |
| 348 | * |
| 349 | * Go through the stage 2 page tables and invalidate any cache lines |
| 350 | * backing memory already mapped to the VM. |
| 351 | */ |
| 352 | static void stage2_flush_vm(struct kvm *kvm) |
| 353 | { |
| 354 | struct kvm_memslots *slots; |
| 355 | struct kvm_memory_slot *memslot; |
| 356 | int idx, bkt; |
| 357 | |
| 358 | idx = srcu_read_lock(&kvm->srcu); |
| 359 | write_lock(&kvm->mmu_lock); |
| 360 | |
| 361 | slots = kvm_memslots(kvm); |
| 362 | kvm_for_each_memslot(memslot, bkt, slots) |
| 363 | stage2_flush_memslot(kvm, memslot); |
| 364 | |
| 365 | write_unlock(&kvm->mmu_lock); |
| 366 | srcu_read_unlock(&kvm->srcu, idx); |
| 367 | } |
| 368 | |
| 369 | /** |
| 370 | * free_hyp_pgds - free Hyp-mode page tables |
| 371 | */ |
| 372 | void __init free_hyp_pgds(void) |
| 373 | { |
| 374 | mutex_lock(&kvm_hyp_pgd_mutex); |
| 375 | if (hyp_pgtable) { |
| 376 | kvm_pgtable_hyp_destroy(hyp_pgtable); |
| 377 | kfree(hyp_pgtable); |
| 378 | hyp_pgtable = NULL; |
| 379 | } |
| 380 | mutex_unlock(&kvm_hyp_pgd_mutex); |
| 381 | } |
| 382 | |
| 383 | static bool kvm_host_owns_hyp_mappings(void) |
| 384 | { |
| 385 | if (is_kernel_in_hyp_mode()) |
| 386 | return false; |
| 387 | |
| 388 | if (static_branch_likely(&kvm_protected_mode_initialized)) |
| 389 | return false; |
| 390 | |
| 391 | /* |
| 392 | * This can happen at boot time when __create_hyp_mappings() is called |
| 393 | * after the hyp protection has been enabled, but the static key has |
| 394 | * not been flipped yet. |
| 395 | */ |
| 396 | if (!hyp_pgtable && is_protected_kvm_enabled()) |
| 397 | return false; |
| 398 | |
| 399 | WARN_ON(!hyp_pgtable); |
| 400 | |
| 401 | return true; |
| 402 | } |
| 403 | |
| 404 | int __create_hyp_mappings(unsigned long start, unsigned long size, |
| 405 | unsigned long phys, enum kvm_pgtable_prot prot) |
| 406 | { |
| 407 | int err; |
| 408 | |
| 409 | if (WARN_ON(!kvm_host_owns_hyp_mappings())) |
| 410 | return -EINVAL; |
| 411 | |
| 412 | mutex_lock(&kvm_hyp_pgd_mutex); |
| 413 | err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot); |
| 414 | mutex_unlock(&kvm_hyp_pgd_mutex); |
| 415 | |
| 416 | return err; |
| 417 | } |
| 418 | |
| 419 | static phys_addr_t kvm_kaddr_to_phys(void *kaddr) |
| 420 | { |
| 421 | if (!is_vmalloc_addr(kaddr)) { |
| 422 | BUG_ON(!virt_addr_valid(kaddr)); |
| 423 | return __pa(kaddr); |
| 424 | } else { |
| 425 | return page_to_phys(vmalloc_to_page(kaddr)) + |
| 426 | offset_in_page(kaddr); |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | struct hyp_shared_pfn { |
| 431 | u64 pfn; |
| 432 | int count; |
| 433 | struct rb_node node; |
| 434 | }; |
| 435 | |
| 436 | static DEFINE_MUTEX(hyp_shared_pfns_lock); |
| 437 | static struct rb_root hyp_shared_pfns = RB_ROOT; |
| 438 | |
| 439 | static struct hyp_shared_pfn *find_shared_pfn(u64 pfn, struct rb_node ***node, |
| 440 | struct rb_node **parent) |
| 441 | { |
| 442 | struct hyp_shared_pfn *this; |
| 443 | |
| 444 | *node = &hyp_shared_pfns.rb_node; |
| 445 | *parent = NULL; |
| 446 | while (**node) { |
| 447 | this = container_of(**node, struct hyp_shared_pfn, node); |
| 448 | *parent = **node; |
| 449 | if (this->pfn < pfn) |
| 450 | *node = &((**node)->rb_left); |
| 451 | else if (this->pfn > pfn) |
| 452 | *node = &((**node)->rb_right); |
| 453 | else |
| 454 | return this; |
| 455 | } |
| 456 | |
| 457 | return NULL; |
| 458 | } |
| 459 | |
| 460 | static int share_pfn_hyp(u64 pfn) |
| 461 | { |
| 462 | struct rb_node **node, *parent; |
| 463 | struct hyp_shared_pfn *this; |
| 464 | int ret = 0; |
| 465 | |
| 466 | mutex_lock(&hyp_shared_pfns_lock); |
| 467 | this = find_shared_pfn(pfn, &node, &parent); |
| 468 | if (this) { |
| 469 | this->count++; |
| 470 | goto unlock; |
| 471 | } |
| 472 | |
| 473 | this = kzalloc(sizeof(*this), GFP_KERNEL); |
| 474 | if (!this) { |
| 475 | ret = -ENOMEM; |
| 476 | goto unlock; |
| 477 | } |
| 478 | |
| 479 | this->pfn = pfn; |
| 480 | this->count = 1; |
| 481 | rb_link_node(&this->node, parent, node); |
| 482 | rb_insert_color(&this->node, &hyp_shared_pfns); |
| 483 | ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn, 1); |
| 484 | unlock: |
| 485 | mutex_unlock(&hyp_shared_pfns_lock); |
| 486 | |
| 487 | return ret; |
| 488 | } |
| 489 | |
| 490 | static int unshare_pfn_hyp(u64 pfn) |
| 491 | { |
| 492 | struct rb_node **node, *parent; |
| 493 | struct hyp_shared_pfn *this; |
| 494 | int ret = 0; |
| 495 | |
| 496 | mutex_lock(&hyp_shared_pfns_lock); |
| 497 | this = find_shared_pfn(pfn, &node, &parent); |
| 498 | if (WARN_ON(!this)) { |
| 499 | ret = -ENOENT; |
| 500 | goto unlock; |
| 501 | } |
| 502 | |
| 503 | this->count--; |
| 504 | if (this->count) |
| 505 | goto unlock; |
| 506 | |
| 507 | rb_erase(&this->node, &hyp_shared_pfns); |
| 508 | kfree(this); |
| 509 | ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn, 1); |
| 510 | unlock: |
| 511 | mutex_unlock(&hyp_shared_pfns_lock); |
| 512 | |
| 513 | return ret; |
| 514 | } |
| 515 | |
| 516 | int kvm_share_hyp(void *from, void *to) |
| 517 | { |
| 518 | phys_addr_t start, end, cur; |
| 519 | u64 pfn; |
| 520 | int ret; |
| 521 | |
| 522 | if (is_kernel_in_hyp_mode()) |
| 523 | return 0; |
| 524 | |
| 525 | /* |
| 526 | * The share hcall maps things in the 'fixed-offset' region of the hyp |
| 527 | * VA space, so we can only share physically contiguous data-structures |
| 528 | * for now. |
| 529 | */ |
| 530 | if (is_vmalloc_or_module_addr(from) || is_vmalloc_or_module_addr(to)) |
| 531 | return -EINVAL; |
| 532 | |
| 533 | if (kvm_host_owns_hyp_mappings()) |
| 534 | return create_hyp_mappings(from, to, PAGE_HYP); |
| 535 | |
| 536 | start = ALIGN_DOWN(__pa(from), PAGE_SIZE); |
| 537 | end = PAGE_ALIGN(__pa(to)); |
| 538 | for (cur = start; cur < end; cur += PAGE_SIZE) { |
| 539 | pfn = __phys_to_pfn(cur); |
| 540 | ret = share_pfn_hyp(pfn); |
| 541 | if (ret) |
| 542 | return ret; |
| 543 | } |
| 544 | |
| 545 | return 0; |
| 546 | } |
| 547 | |
| 548 | void kvm_unshare_hyp(void *from, void *to) |
| 549 | { |
| 550 | phys_addr_t start, end, cur; |
| 551 | u64 pfn; |
| 552 | |
| 553 | if (is_kernel_in_hyp_mode() || kvm_host_owns_hyp_mappings() || !from) |
| 554 | return; |
| 555 | |
| 556 | start = ALIGN_DOWN(__pa(from), PAGE_SIZE); |
| 557 | end = PAGE_ALIGN(__pa(to)); |
| 558 | for (cur = start; cur < end; cur += PAGE_SIZE) { |
| 559 | pfn = __phys_to_pfn(cur); |
| 560 | WARN_ON(unshare_pfn_hyp(pfn)); |
| 561 | } |
| 562 | } |
| 563 | |
| 564 | /** |
| 565 | * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode |
| 566 | * @from: The virtual kernel start address of the range |
| 567 | * @to: The virtual kernel end address of the range (exclusive) |
| 568 | * @prot: The protection to be applied to this range |
| 569 | * |
| 570 | * The same virtual address as the kernel virtual address is also used |
| 571 | * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying |
| 572 | * physical pages. |
| 573 | */ |
| 574 | int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot) |
| 575 | { |
| 576 | phys_addr_t phys_addr; |
| 577 | unsigned long virt_addr; |
| 578 | unsigned long start = kern_hyp_va((unsigned long)from); |
| 579 | unsigned long end = kern_hyp_va((unsigned long)to); |
| 580 | |
| 581 | if (is_kernel_in_hyp_mode()) |
| 582 | return 0; |
| 583 | |
| 584 | if (!kvm_host_owns_hyp_mappings()) |
| 585 | return -EPERM; |
| 586 | |
| 587 | start = start & PAGE_MASK; |
| 588 | end = PAGE_ALIGN(end); |
| 589 | |
| 590 | for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { |
| 591 | int err; |
| 592 | |
| 593 | phys_addr = kvm_kaddr_to_phys(from + virt_addr - start); |
| 594 | err = __create_hyp_mappings(virt_addr, PAGE_SIZE, phys_addr, |
| 595 | prot); |
| 596 | if (err) |
| 597 | return err; |
| 598 | } |
| 599 | |
| 600 | return 0; |
| 601 | } |
| 602 | |
| 603 | static int __hyp_alloc_private_va_range(unsigned long base) |
| 604 | { |
| 605 | lockdep_assert_held(&kvm_hyp_pgd_mutex); |
| 606 | |
| 607 | if (!PAGE_ALIGNED(base)) |
| 608 | return -EINVAL; |
| 609 | |
| 610 | /* |
| 611 | * Verify that BIT(VA_BITS - 1) hasn't been flipped by |
| 612 | * allocating the new area, as it would indicate we've |
| 613 | * overflowed the idmap/IO address range. |
| 614 | */ |
| 615 | if ((base ^ io_map_base) & BIT(VA_BITS - 1)) |
| 616 | return -ENOMEM; |
| 617 | |
| 618 | io_map_base = base; |
| 619 | |
| 620 | return 0; |
| 621 | } |
| 622 | |
| 623 | /** |
| 624 | * hyp_alloc_private_va_range - Allocates a private VA range. |
| 625 | * @size: The size of the VA range to reserve. |
| 626 | * @haddr: The hypervisor virtual start address of the allocation. |
| 627 | * |
| 628 | * The private virtual address (VA) range is allocated below io_map_base |
| 629 | * and aligned based on the order of @size. |
| 630 | * |
| 631 | * Return: 0 on success or negative error code on failure. |
| 632 | */ |
| 633 | int hyp_alloc_private_va_range(size_t size, unsigned long *haddr) |
| 634 | { |
| 635 | unsigned long base; |
| 636 | int ret = 0; |
| 637 | |
| 638 | mutex_lock(&kvm_hyp_pgd_mutex); |
| 639 | |
| 640 | /* |
| 641 | * This assumes that we have enough space below the idmap |
| 642 | * page to allocate our VAs. If not, the check in |
| 643 | * __hyp_alloc_private_va_range() will kick. A potential |
| 644 | * alternative would be to detect that overflow and switch |
| 645 | * to an allocation above the idmap. |
| 646 | * |
| 647 | * The allocated size is always a multiple of PAGE_SIZE. |
| 648 | */ |
| 649 | size = PAGE_ALIGN(size); |
| 650 | base = io_map_base - size; |
| 651 | ret = __hyp_alloc_private_va_range(base); |
| 652 | |
| 653 | mutex_unlock(&kvm_hyp_pgd_mutex); |
| 654 | |
| 655 | if (!ret) |
| 656 | *haddr = base; |
| 657 | |
| 658 | return ret; |
| 659 | } |
| 660 | |
| 661 | static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, |
| 662 | unsigned long *haddr, |
| 663 | enum kvm_pgtable_prot prot) |
| 664 | { |
| 665 | unsigned long addr; |
| 666 | int ret = 0; |
| 667 | |
| 668 | if (!kvm_host_owns_hyp_mappings()) { |
| 669 | addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping, |
| 670 | phys_addr, size, prot); |
| 671 | if (IS_ERR_VALUE(addr)) |
| 672 | return addr; |
| 673 | *haddr = addr; |
| 674 | |
| 675 | return 0; |
| 676 | } |
| 677 | |
| 678 | size = PAGE_ALIGN(size + offset_in_page(phys_addr)); |
| 679 | ret = hyp_alloc_private_va_range(size, &addr); |
| 680 | if (ret) |
| 681 | return ret; |
| 682 | |
| 683 | ret = __create_hyp_mappings(addr, size, phys_addr, prot); |
| 684 | if (ret) |
| 685 | return ret; |
| 686 | |
| 687 | *haddr = addr + offset_in_page(phys_addr); |
| 688 | return ret; |
| 689 | } |
| 690 | |
| 691 | int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr) |
| 692 | { |
| 693 | unsigned long base; |
| 694 | size_t size; |
| 695 | int ret; |
| 696 | |
| 697 | mutex_lock(&kvm_hyp_pgd_mutex); |
| 698 | /* |
| 699 | * Efficient stack verification using the PAGE_SHIFT bit implies |
| 700 | * an alignment of our allocation on the order of the size. |
| 701 | */ |
| 702 | size = PAGE_SIZE * 2; |
| 703 | base = ALIGN_DOWN(io_map_base - size, size); |
| 704 | |
| 705 | ret = __hyp_alloc_private_va_range(base); |
| 706 | |
| 707 | mutex_unlock(&kvm_hyp_pgd_mutex); |
| 708 | |
| 709 | if (ret) { |
| 710 | kvm_err("Cannot allocate hyp stack guard page\n"); |
| 711 | return ret; |
| 712 | } |
| 713 | |
| 714 | /* |
| 715 | * Since the stack grows downwards, map the stack to the page |
| 716 | * at the higher address and leave the lower guard page |
| 717 | * unbacked. |
| 718 | * |
| 719 | * Any valid stack address now has the PAGE_SHIFT bit as 1 |
| 720 | * and addresses corresponding to the guard page have the |
| 721 | * PAGE_SHIFT bit as 0 - this is used for overflow detection. |
| 722 | */ |
| 723 | ret = __create_hyp_mappings(base + PAGE_SIZE, PAGE_SIZE, phys_addr, |
| 724 | PAGE_HYP); |
| 725 | if (ret) |
| 726 | kvm_err("Cannot map hyp stack\n"); |
| 727 | |
| 728 | *haddr = base + size; |
| 729 | |
| 730 | return ret; |
| 731 | } |
| 732 | |
| 733 | /** |
| 734 | * create_hyp_io_mappings - Map IO into both kernel and HYP |
| 735 | * @phys_addr: The physical start address which gets mapped |
| 736 | * @size: Size of the region being mapped |
| 737 | * @kaddr: Kernel VA for this mapping |
| 738 | * @haddr: HYP VA for this mapping |
| 739 | */ |
| 740 | int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, |
| 741 | void __iomem **kaddr, |
| 742 | void __iomem **haddr) |
| 743 | { |
| 744 | unsigned long addr; |
| 745 | int ret; |
| 746 | |
| 747 | if (is_protected_kvm_enabled()) |
| 748 | return -EPERM; |
| 749 | |
| 750 | *kaddr = ioremap(phys_addr, size); |
| 751 | if (!*kaddr) |
| 752 | return -ENOMEM; |
| 753 | |
| 754 | if (is_kernel_in_hyp_mode()) { |
| 755 | *haddr = *kaddr; |
| 756 | return 0; |
| 757 | } |
| 758 | |
| 759 | ret = __create_hyp_private_mapping(phys_addr, size, |
| 760 | &addr, PAGE_HYP_DEVICE); |
| 761 | if (ret) { |
| 762 | iounmap(*kaddr); |
| 763 | *kaddr = NULL; |
| 764 | *haddr = NULL; |
| 765 | return ret; |
| 766 | } |
| 767 | |
| 768 | *haddr = (void __iomem *)addr; |
| 769 | return 0; |
| 770 | } |
| 771 | |
| 772 | /** |
| 773 | * create_hyp_exec_mappings - Map an executable range into HYP |
| 774 | * @phys_addr: The physical start address which gets mapped |
| 775 | * @size: Size of the region being mapped |
| 776 | * @haddr: HYP VA for this mapping |
| 777 | */ |
| 778 | int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, |
| 779 | void **haddr) |
| 780 | { |
| 781 | unsigned long addr; |
| 782 | int ret; |
| 783 | |
| 784 | BUG_ON(is_kernel_in_hyp_mode()); |
| 785 | |
| 786 | ret = __create_hyp_private_mapping(phys_addr, size, |
| 787 | &addr, PAGE_HYP_EXEC); |
| 788 | if (ret) { |
| 789 | *haddr = NULL; |
| 790 | return ret; |
| 791 | } |
| 792 | |
| 793 | *haddr = (void *)addr; |
| 794 | return 0; |
| 795 | } |
| 796 | |
| 797 | static struct kvm_pgtable_mm_ops kvm_user_mm_ops = { |
| 798 | /* We shouldn't need any other callback to walk the PT */ |
| 799 | .phys_to_virt = kvm_host_va, |
| 800 | }; |
| 801 | |
| 802 | static int get_user_mapping_size(struct kvm *kvm, u64 addr) |
| 803 | { |
| 804 | struct kvm_pgtable pgt = { |
| 805 | .pgd = (kvm_pteref_t)kvm->mm->pgd, |
| 806 | .ia_bits = vabits_actual, |
| 807 | .start_level = (KVM_PGTABLE_LAST_LEVEL - |
| 808 | ARM64_HW_PGTABLE_LEVELS(pgt.ia_bits) + 1), |
| 809 | .mm_ops = &kvm_user_mm_ops, |
| 810 | }; |
| 811 | unsigned long flags; |
| 812 | kvm_pte_t pte = 0; /* Keep GCC quiet... */ |
| 813 | s8 level = S8_MAX; |
| 814 | int ret; |
| 815 | |
| 816 | /* |
| 817 | * Disable IRQs so that we hazard against a concurrent |
| 818 | * teardown of the userspace page tables (which relies on |
| 819 | * IPI-ing threads). |
| 820 | */ |
| 821 | local_irq_save(flags); |
| 822 | ret = kvm_pgtable_get_leaf(&pgt, addr, &pte, &level); |
| 823 | local_irq_restore(flags); |
| 824 | |
| 825 | if (ret) |
| 826 | return ret; |
| 827 | |
| 828 | /* |
| 829 | * Not seeing an error, but not updating level? Something went |
| 830 | * deeply wrong... |
| 831 | */ |
| 832 | if (WARN_ON(level > KVM_PGTABLE_LAST_LEVEL)) |
| 833 | return -EFAULT; |
| 834 | if (WARN_ON(level < KVM_PGTABLE_FIRST_LEVEL)) |
| 835 | return -EFAULT; |
| 836 | |
| 837 | /* Oops, the userspace PTs are gone... Replay the fault */ |
| 838 | if (!kvm_pte_valid(pte)) |
| 839 | return -EAGAIN; |
| 840 | |
| 841 | return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(level)); |
| 842 | } |
| 843 | |
| 844 | static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = { |
| 845 | .zalloc_page = stage2_memcache_zalloc_page, |
| 846 | .zalloc_pages_exact = kvm_s2_zalloc_pages_exact, |
| 847 | .free_pages_exact = kvm_s2_free_pages_exact, |
| 848 | .free_unlinked_table = stage2_free_unlinked_table, |
| 849 | .get_page = kvm_host_get_page, |
| 850 | .put_page = kvm_s2_put_page, |
| 851 | .page_count = kvm_host_page_count, |
| 852 | .phys_to_virt = kvm_host_va, |
| 853 | .virt_to_phys = kvm_host_pa, |
| 854 | .dcache_clean_inval_poc = clean_dcache_guest_page, |
| 855 | .icache_inval_pou = invalidate_icache_guest_page, |
| 856 | }; |
| 857 | |
| 858 | /** |
| 859 | * kvm_init_stage2_mmu - Initialise a S2 MMU structure |
| 860 | * @kvm: The pointer to the KVM structure |
| 861 | * @mmu: The pointer to the s2 MMU structure |
| 862 | * @type: The machine type of the virtual machine |
| 863 | * |
| 864 | * Allocates only the stage-2 HW PGD level table(s). |
| 865 | * Note we don't need locking here as this is only called when the VM is |
| 866 | * created, which can only be done once. |
| 867 | */ |
| 868 | int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type) |
| 869 | { |
| 870 | u32 kvm_ipa_limit = get_kvm_ipa_limit(); |
| 871 | int cpu, err; |
| 872 | struct kvm_pgtable *pgt; |
| 873 | u64 mmfr0, mmfr1; |
| 874 | u32 phys_shift; |
| 875 | |
| 876 | if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK) |
| 877 | return -EINVAL; |
| 878 | |
| 879 | phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type); |
| 880 | if (is_protected_kvm_enabled()) { |
| 881 | phys_shift = kvm_ipa_limit; |
| 882 | } else if (phys_shift) { |
| 883 | if (phys_shift > kvm_ipa_limit || |
| 884 | phys_shift < ARM64_MIN_PARANGE_BITS) |
| 885 | return -EINVAL; |
| 886 | } else { |
| 887 | phys_shift = KVM_PHYS_SHIFT; |
| 888 | if (phys_shift > kvm_ipa_limit) { |
| 889 | pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n", |
| 890 | current->comm); |
| 891 | return -EINVAL; |
| 892 | } |
| 893 | } |
| 894 | |
| 895 | mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); |
| 896 | mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); |
| 897 | mmu->vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift); |
| 898 | |
| 899 | if (mmu->pgt != NULL) { |
| 900 | kvm_err("kvm_arch already initialized?\n"); |
| 901 | return -EINVAL; |
| 902 | } |
| 903 | |
| 904 | pgt = kzalloc(sizeof(*pgt), GFP_KERNEL_ACCOUNT); |
| 905 | if (!pgt) |
| 906 | return -ENOMEM; |
| 907 | |
| 908 | mmu->arch = &kvm->arch; |
| 909 | err = kvm_pgtable_stage2_init(pgt, mmu, &kvm_s2_mm_ops); |
| 910 | if (err) |
| 911 | goto out_free_pgtable; |
| 912 | |
| 913 | mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran)); |
| 914 | if (!mmu->last_vcpu_ran) { |
| 915 | err = -ENOMEM; |
| 916 | goto out_destroy_pgtable; |
| 917 | } |
| 918 | |
| 919 | for_each_possible_cpu(cpu) |
| 920 | *per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1; |
| 921 | |
| 922 | /* The eager page splitting is disabled by default */ |
| 923 | mmu->split_page_chunk_size = KVM_ARM_EAGER_SPLIT_CHUNK_SIZE_DEFAULT; |
| 924 | mmu->split_page_cache.gfp_zero = __GFP_ZERO; |
| 925 | |
| 926 | mmu->pgt = pgt; |
| 927 | mmu->pgd_phys = __pa(pgt->pgd); |
| 928 | return 0; |
| 929 | |
| 930 | out_destroy_pgtable: |
| 931 | kvm_pgtable_stage2_destroy(pgt); |
| 932 | out_free_pgtable: |
| 933 | kfree(pgt); |
| 934 | return err; |
| 935 | } |
| 936 | |
| 937 | void kvm_uninit_stage2_mmu(struct kvm *kvm) |
| 938 | { |
| 939 | kvm_free_stage2_pgd(&kvm->arch.mmu); |
| 940 | kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache); |
| 941 | } |
| 942 | |
| 943 | static void stage2_unmap_memslot(struct kvm *kvm, |
| 944 | struct kvm_memory_slot *memslot) |
| 945 | { |
| 946 | hva_t hva = memslot->userspace_addr; |
| 947 | phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; |
| 948 | phys_addr_t size = PAGE_SIZE * memslot->npages; |
| 949 | hva_t reg_end = hva + size; |
| 950 | |
| 951 | /* |
| 952 | * A memory region could potentially cover multiple VMAs, and any holes |
| 953 | * between them, so iterate over all of them to find out if we should |
| 954 | * unmap any of them. |
| 955 | * |
| 956 | * +--------------------------------------------+ |
| 957 | * +---------------+----------------+ +----------------+ |
| 958 | * | : VMA 1 | VMA 2 | | VMA 3 : | |
| 959 | * +---------------+----------------+ +----------------+ |
| 960 | * | memory region | |
| 961 | * +--------------------------------------------+ |
| 962 | */ |
| 963 | do { |
| 964 | struct vm_area_struct *vma; |
| 965 | hva_t vm_start, vm_end; |
| 966 | |
| 967 | vma = find_vma_intersection(current->mm, hva, reg_end); |
| 968 | if (!vma) |
| 969 | break; |
| 970 | |
| 971 | /* |
| 972 | * Take the intersection of this VMA with the memory region |
| 973 | */ |
| 974 | vm_start = max(hva, vma->vm_start); |
| 975 | vm_end = min(reg_end, vma->vm_end); |
| 976 | |
| 977 | if (!(vma->vm_flags & VM_PFNMAP)) { |
| 978 | gpa_t gpa = addr + (vm_start - memslot->userspace_addr); |
| 979 | unmap_stage2_range(&kvm->arch.mmu, gpa, vm_end - vm_start); |
| 980 | } |
| 981 | hva = vm_end; |
| 982 | } while (hva < reg_end); |
| 983 | } |
| 984 | |
| 985 | /** |
| 986 | * stage2_unmap_vm - Unmap Stage-2 RAM mappings |
| 987 | * @kvm: The struct kvm pointer |
| 988 | * |
| 989 | * Go through the memregions and unmap any regular RAM |
| 990 | * backing memory already mapped to the VM. |
| 991 | */ |
| 992 | void stage2_unmap_vm(struct kvm *kvm) |
| 993 | { |
| 994 | struct kvm_memslots *slots; |
| 995 | struct kvm_memory_slot *memslot; |
| 996 | int idx, bkt; |
| 997 | |
| 998 | idx = srcu_read_lock(&kvm->srcu); |
| 999 | mmap_read_lock(current->mm); |
| 1000 | write_lock(&kvm->mmu_lock); |
| 1001 | |
| 1002 | slots = kvm_memslots(kvm); |
| 1003 | kvm_for_each_memslot(memslot, bkt, slots) |
| 1004 | stage2_unmap_memslot(kvm, memslot); |
| 1005 | |
| 1006 | write_unlock(&kvm->mmu_lock); |
| 1007 | mmap_read_unlock(current->mm); |
| 1008 | srcu_read_unlock(&kvm->srcu, idx); |
| 1009 | } |
| 1010 | |
| 1011 | void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu) |
| 1012 | { |
| 1013 | struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); |
| 1014 | struct kvm_pgtable *pgt = NULL; |
| 1015 | |
| 1016 | write_lock(&kvm->mmu_lock); |
| 1017 | pgt = mmu->pgt; |
| 1018 | if (pgt) { |
| 1019 | mmu->pgd_phys = 0; |
| 1020 | mmu->pgt = NULL; |
| 1021 | free_percpu(mmu->last_vcpu_ran); |
| 1022 | } |
| 1023 | write_unlock(&kvm->mmu_lock); |
| 1024 | |
| 1025 | if (pgt) { |
| 1026 | kvm_pgtable_stage2_destroy(pgt); |
| 1027 | kfree(pgt); |
| 1028 | } |
| 1029 | } |
| 1030 | |
| 1031 | static void hyp_mc_free_fn(void *addr, void *unused) |
| 1032 | { |
| 1033 | free_page((unsigned long)addr); |
| 1034 | } |
| 1035 | |
| 1036 | static void *hyp_mc_alloc_fn(void *unused) |
| 1037 | { |
| 1038 | return (void *)__get_free_page(GFP_KERNEL_ACCOUNT); |
| 1039 | } |
| 1040 | |
| 1041 | void free_hyp_memcache(struct kvm_hyp_memcache *mc) |
| 1042 | { |
| 1043 | if (is_protected_kvm_enabled()) |
| 1044 | __free_hyp_memcache(mc, hyp_mc_free_fn, |
| 1045 | kvm_host_va, NULL); |
| 1046 | } |
| 1047 | |
| 1048 | int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages) |
| 1049 | { |
| 1050 | if (!is_protected_kvm_enabled()) |
| 1051 | return 0; |
| 1052 | |
| 1053 | return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn, |
| 1054 | kvm_host_pa, NULL); |
| 1055 | } |
| 1056 | |
| 1057 | /** |
| 1058 | * kvm_phys_addr_ioremap - map a device range to guest IPA |
| 1059 | * |
| 1060 | * @kvm: The KVM pointer |
| 1061 | * @guest_ipa: The IPA at which to insert the mapping |
| 1062 | * @pa: The physical address of the device |
| 1063 | * @size: The size of the mapping |
| 1064 | * @writable: Whether or not to create a writable mapping |
| 1065 | */ |
| 1066 | int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, |
| 1067 | phys_addr_t pa, unsigned long size, bool writable) |
| 1068 | { |
| 1069 | phys_addr_t addr; |
| 1070 | int ret = 0; |
| 1071 | struct kvm_mmu_memory_cache cache = { .gfp_zero = __GFP_ZERO }; |
| 1072 | struct kvm_s2_mmu *mmu = &kvm->arch.mmu; |
| 1073 | struct kvm_pgtable *pgt = mmu->pgt; |
| 1074 | enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_DEVICE | |
| 1075 | KVM_PGTABLE_PROT_R | |
| 1076 | (writable ? KVM_PGTABLE_PROT_W : 0); |
| 1077 | |
| 1078 | if (is_protected_kvm_enabled()) |
| 1079 | return -EPERM; |
| 1080 | |
| 1081 | size += offset_in_page(guest_ipa); |
| 1082 | guest_ipa &= PAGE_MASK; |
| 1083 | |
| 1084 | for (addr = guest_ipa; addr < guest_ipa + size; addr += PAGE_SIZE) { |
| 1085 | ret = kvm_mmu_topup_memory_cache(&cache, |
| 1086 | kvm_mmu_cache_min_pages(mmu)); |
| 1087 | if (ret) |
| 1088 | break; |
| 1089 | |
| 1090 | write_lock(&kvm->mmu_lock); |
| 1091 | ret = kvm_pgtable_stage2_map(pgt, addr, PAGE_SIZE, pa, prot, |
| 1092 | &cache, 0); |
| 1093 | write_unlock(&kvm->mmu_lock); |
| 1094 | if (ret) |
| 1095 | break; |
| 1096 | |
| 1097 | pa += PAGE_SIZE; |
| 1098 | } |
| 1099 | |
| 1100 | kvm_mmu_free_memory_cache(&cache); |
| 1101 | return ret; |
| 1102 | } |
| 1103 | |
| 1104 | /** |
| 1105 | * stage2_wp_range() - write protect stage2 memory region range |
| 1106 | * @mmu: The KVM stage-2 MMU pointer |
| 1107 | * @addr: Start address of range |
| 1108 | * @end: End address of range |
| 1109 | */ |
| 1110 | static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end) |
| 1111 | { |
| 1112 | stage2_apply_range_resched(mmu, addr, end, kvm_pgtable_stage2_wrprotect); |
| 1113 | } |
| 1114 | |
| 1115 | /** |
| 1116 | * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot |
| 1117 | * @kvm: The KVM pointer |
| 1118 | * @slot: The memory slot to write protect |
| 1119 | * |
| 1120 | * Called to start logging dirty pages after memory region |
| 1121 | * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns |
| 1122 | * all present PUD, PMD and PTEs are write protected in the memory region. |
| 1123 | * Afterwards read of dirty page log can be called. |
| 1124 | * |
| 1125 | * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired, |
| 1126 | * serializing operations for VM memory regions. |
| 1127 | */ |
| 1128 | static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot) |
| 1129 | { |
| 1130 | struct kvm_memslots *slots = kvm_memslots(kvm); |
| 1131 | struct kvm_memory_slot *memslot = id_to_memslot(slots, slot); |
| 1132 | phys_addr_t start, end; |
| 1133 | |
| 1134 | if (WARN_ON_ONCE(!memslot)) |
| 1135 | return; |
| 1136 | |
| 1137 | start = memslot->base_gfn << PAGE_SHIFT; |
| 1138 | end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; |
| 1139 | |
| 1140 | write_lock(&kvm->mmu_lock); |
| 1141 | stage2_wp_range(&kvm->arch.mmu, start, end); |
| 1142 | write_unlock(&kvm->mmu_lock); |
| 1143 | kvm_flush_remote_tlbs_memslot(kvm, memslot); |
| 1144 | } |
| 1145 | |
| 1146 | /** |
| 1147 | * kvm_mmu_split_memory_region() - split the stage 2 blocks into PAGE_SIZE |
| 1148 | * pages for memory slot |
| 1149 | * @kvm: The KVM pointer |
| 1150 | * @slot: The memory slot to split |
| 1151 | * |
| 1152 | * Acquires kvm->mmu_lock. Called with kvm->slots_lock mutex acquired, |
| 1153 | * serializing operations for VM memory regions. |
| 1154 | */ |
| 1155 | static void kvm_mmu_split_memory_region(struct kvm *kvm, int slot) |
| 1156 | { |
| 1157 | struct kvm_memslots *slots; |
| 1158 | struct kvm_memory_slot *memslot; |
| 1159 | phys_addr_t start, end; |
| 1160 | |
| 1161 | lockdep_assert_held(&kvm->slots_lock); |
| 1162 | |
| 1163 | slots = kvm_memslots(kvm); |
| 1164 | memslot = id_to_memslot(slots, slot); |
| 1165 | |
| 1166 | start = memslot->base_gfn << PAGE_SHIFT; |
| 1167 | end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; |
| 1168 | |
| 1169 | write_lock(&kvm->mmu_lock); |
| 1170 | kvm_mmu_split_huge_pages(kvm, start, end); |
| 1171 | write_unlock(&kvm->mmu_lock); |
| 1172 | } |
| 1173 | |
| 1174 | /* |
| 1175 | * kvm_arch_mmu_enable_log_dirty_pt_masked() - enable dirty logging for selected pages. |
| 1176 | * @kvm: The KVM pointer |
| 1177 | * @slot: The memory slot associated with mask |
| 1178 | * @gfn_offset: The gfn offset in memory slot |
| 1179 | * @mask: The mask of pages at offset 'gfn_offset' in this memory |
| 1180 | * slot to enable dirty logging on |
| 1181 | * |
| 1182 | * Writes protect selected pages to enable dirty logging, and then |
| 1183 | * splits them to PAGE_SIZE. Caller must acquire kvm->mmu_lock. |
| 1184 | */ |
| 1185 | void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, |
| 1186 | struct kvm_memory_slot *slot, |
| 1187 | gfn_t gfn_offset, unsigned long mask) |
| 1188 | { |
| 1189 | phys_addr_t base_gfn = slot->base_gfn + gfn_offset; |
| 1190 | phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; |
| 1191 | phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; |
| 1192 | |
| 1193 | lockdep_assert_held_write(&kvm->mmu_lock); |
| 1194 | |
| 1195 | stage2_wp_range(&kvm->arch.mmu, start, end); |
| 1196 | |
| 1197 | /* |
| 1198 | * Eager-splitting is done when manual-protect is set. We |
| 1199 | * also check for initially-all-set because we can avoid |
| 1200 | * eager-splitting if initially-all-set is false. |
| 1201 | * Initially-all-set equal false implies that huge-pages were |
| 1202 | * already split when enabling dirty logging: no need to do it |
| 1203 | * again. |
| 1204 | */ |
| 1205 | if (kvm_dirty_log_manual_protect_and_init_set(kvm)) |
| 1206 | kvm_mmu_split_huge_pages(kvm, start, end); |
| 1207 | } |
| 1208 | |
| 1209 | static void kvm_send_hwpoison_signal(unsigned long address, short lsb) |
| 1210 | { |
| 1211 | send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current); |
| 1212 | } |
| 1213 | |
| 1214 | static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot, |
| 1215 | unsigned long hva, |
| 1216 | unsigned long map_size) |
| 1217 | { |
| 1218 | gpa_t gpa_start; |
| 1219 | hva_t uaddr_start, uaddr_end; |
| 1220 | size_t size; |
| 1221 | |
| 1222 | /* The memslot and the VMA are guaranteed to be aligned to PAGE_SIZE */ |
| 1223 | if (map_size == PAGE_SIZE) |
| 1224 | return true; |
| 1225 | |
| 1226 | size = memslot->npages * PAGE_SIZE; |
| 1227 | |
| 1228 | gpa_start = memslot->base_gfn << PAGE_SHIFT; |
| 1229 | |
| 1230 | uaddr_start = memslot->userspace_addr; |
| 1231 | uaddr_end = uaddr_start + size; |
| 1232 | |
| 1233 | /* |
| 1234 | * Pages belonging to memslots that don't have the same alignment |
| 1235 | * within a PMD/PUD for userspace and IPA cannot be mapped with stage-2 |
| 1236 | * PMD/PUD entries, because we'll end up mapping the wrong pages. |
| 1237 | * |
| 1238 | * Consider a layout like the following: |
| 1239 | * |
| 1240 | * memslot->userspace_addr: |
| 1241 | * +-----+--------------------+--------------------+---+ |
| 1242 | * |abcde|fgh Stage-1 block | Stage-1 block tv|xyz| |
| 1243 | * +-----+--------------------+--------------------+---+ |
| 1244 | * |
| 1245 | * memslot->base_gfn << PAGE_SHIFT: |
| 1246 | * +---+--------------------+--------------------+-----+ |
| 1247 | * |abc|def Stage-2 block | Stage-2 block |tvxyz| |
| 1248 | * +---+--------------------+--------------------+-----+ |
| 1249 | * |
| 1250 | * If we create those stage-2 blocks, we'll end up with this incorrect |
| 1251 | * mapping: |
| 1252 | * d -> f |
| 1253 | * e -> g |
| 1254 | * f -> h |
| 1255 | */ |
| 1256 | if ((gpa_start & (map_size - 1)) != (uaddr_start & (map_size - 1))) |
| 1257 | return false; |
| 1258 | |
| 1259 | /* |
| 1260 | * Next, let's make sure we're not trying to map anything not covered |
| 1261 | * by the memslot. This means we have to prohibit block size mappings |
| 1262 | * for the beginning and end of a non-block aligned and non-block sized |
| 1263 | * memory slot (illustrated by the head and tail parts of the |
| 1264 | * userspace view above containing pages 'abcde' and 'xyz', |
| 1265 | * respectively). |
| 1266 | * |
| 1267 | * Note that it doesn't matter if we do the check using the |
| 1268 | * userspace_addr or the base_gfn, as both are equally aligned (per |
| 1269 | * the check above) and equally sized. |
| 1270 | */ |
| 1271 | return (hva & ~(map_size - 1)) >= uaddr_start && |
| 1272 | (hva & ~(map_size - 1)) + map_size <= uaddr_end; |
| 1273 | } |
| 1274 | |
| 1275 | /* |
| 1276 | * Check if the given hva is backed by a transparent huge page (THP) and |
| 1277 | * whether it can be mapped using block mapping in stage2. If so, adjust |
| 1278 | * the stage2 PFN and IPA accordingly. Only PMD_SIZE THPs are currently |
| 1279 | * supported. This will need to be updated to support other THP sizes. |
| 1280 | * |
| 1281 | * Returns the size of the mapping. |
| 1282 | */ |
| 1283 | static long |
| 1284 | transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot, |
| 1285 | unsigned long hva, kvm_pfn_t *pfnp, |
| 1286 | phys_addr_t *ipap) |
| 1287 | { |
| 1288 | kvm_pfn_t pfn = *pfnp; |
| 1289 | |
| 1290 | /* |
| 1291 | * Make sure the adjustment is done only for THP pages. Also make |
| 1292 | * sure that the HVA and IPA are sufficiently aligned and that the |
| 1293 | * block map is contained within the memslot. |
| 1294 | */ |
| 1295 | if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) { |
| 1296 | int sz = get_user_mapping_size(kvm, hva); |
| 1297 | |
| 1298 | if (sz < 0) |
| 1299 | return sz; |
| 1300 | |
| 1301 | if (sz < PMD_SIZE) |
| 1302 | return PAGE_SIZE; |
| 1303 | |
| 1304 | *ipap &= PMD_MASK; |
| 1305 | pfn &= ~(PTRS_PER_PMD - 1); |
| 1306 | *pfnp = pfn; |
| 1307 | |
| 1308 | return PMD_SIZE; |
| 1309 | } |
| 1310 | |
| 1311 | /* Use page mapping if we cannot use block mapping. */ |
| 1312 | return PAGE_SIZE; |
| 1313 | } |
| 1314 | |
| 1315 | static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva) |
| 1316 | { |
| 1317 | unsigned long pa; |
| 1318 | |
| 1319 | if (is_vm_hugetlb_page(vma) && !(vma->vm_flags & VM_PFNMAP)) |
| 1320 | return huge_page_shift(hstate_vma(vma)); |
| 1321 | |
| 1322 | if (!(vma->vm_flags & VM_PFNMAP)) |
| 1323 | return PAGE_SHIFT; |
| 1324 | |
| 1325 | VM_BUG_ON(is_vm_hugetlb_page(vma)); |
| 1326 | |
| 1327 | pa = (vma->vm_pgoff << PAGE_SHIFT) + (hva - vma->vm_start); |
| 1328 | |
| 1329 | #ifndef __PAGETABLE_PMD_FOLDED |
| 1330 | if ((hva & (PUD_SIZE - 1)) == (pa & (PUD_SIZE - 1)) && |
| 1331 | ALIGN_DOWN(hva, PUD_SIZE) >= vma->vm_start && |
| 1332 | ALIGN(hva, PUD_SIZE) <= vma->vm_end) |
| 1333 | return PUD_SHIFT; |
| 1334 | #endif |
| 1335 | |
| 1336 | if ((hva & (PMD_SIZE - 1)) == (pa & (PMD_SIZE - 1)) && |
| 1337 | ALIGN_DOWN(hva, PMD_SIZE) >= vma->vm_start && |
| 1338 | ALIGN(hva, PMD_SIZE) <= vma->vm_end) |
| 1339 | return PMD_SHIFT; |
| 1340 | |
| 1341 | return PAGE_SHIFT; |
| 1342 | } |
| 1343 | |
| 1344 | /* |
| 1345 | * The page will be mapped in stage 2 as Normal Cacheable, so the VM will be |
| 1346 | * able to see the page's tags and therefore they must be initialised first. If |
| 1347 | * PG_mte_tagged is set, tags have already been initialised. |
| 1348 | * |
| 1349 | * The race in the test/set of the PG_mte_tagged flag is handled by: |
| 1350 | * - preventing VM_SHARED mappings in a memslot with MTE preventing two VMs |
| 1351 | * racing to santise the same page |
| 1352 | * - mmap_lock protects between a VM faulting a page in and the VMM performing |
| 1353 | * an mprotect() to add VM_MTE |
| 1354 | */ |
| 1355 | static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn, |
| 1356 | unsigned long size) |
| 1357 | { |
| 1358 | unsigned long i, nr_pages = size >> PAGE_SHIFT; |
| 1359 | struct page *page = pfn_to_page(pfn); |
| 1360 | |
| 1361 | if (!kvm_has_mte(kvm)) |
| 1362 | return; |
| 1363 | |
| 1364 | for (i = 0; i < nr_pages; i++, page++) { |
| 1365 | if (try_page_mte_tagging(page)) { |
| 1366 | mte_clear_page_tags(page_address(page)); |
| 1367 | set_page_mte_tagged(page); |
| 1368 | } |
| 1369 | } |
| 1370 | } |
| 1371 | |
| 1372 | static bool kvm_vma_mte_allowed(struct vm_area_struct *vma) |
| 1373 | { |
| 1374 | return vma->vm_flags & VM_MTE_ALLOWED; |
| 1375 | } |
| 1376 | |
| 1377 | static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, |
| 1378 | struct kvm_memory_slot *memslot, unsigned long hva, |
| 1379 | bool fault_is_perm) |
| 1380 | { |
| 1381 | int ret = 0; |
| 1382 | bool write_fault, writable, force_pte = false; |
| 1383 | bool exec_fault, mte_allowed; |
| 1384 | bool device = false, vfio_allow_any_uc = false; |
| 1385 | unsigned long mmu_seq; |
| 1386 | struct kvm *kvm = vcpu->kvm; |
| 1387 | struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; |
| 1388 | struct vm_area_struct *vma; |
| 1389 | short vma_shift; |
| 1390 | gfn_t gfn; |
| 1391 | kvm_pfn_t pfn; |
| 1392 | bool logging_active = memslot_is_logging(memslot); |
| 1393 | long vma_pagesize, fault_granule; |
| 1394 | enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R; |
| 1395 | struct kvm_pgtable *pgt; |
| 1396 | |
| 1397 | if (fault_is_perm) |
| 1398 | fault_granule = kvm_vcpu_trap_get_perm_fault_granule(vcpu); |
| 1399 | write_fault = kvm_is_write_fault(vcpu); |
| 1400 | exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu); |
| 1401 | VM_BUG_ON(write_fault && exec_fault); |
| 1402 | |
| 1403 | if (fault_is_perm && !write_fault && !exec_fault) { |
| 1404 | kvm_err("Unexpected L2 read permission error\n"); |
| 1405 | return -EFAULT; |
| 1406 | } |
| 1407 | |
| 1408 | /* |
| 1409 | * Permission faults just need to update the existing leaf entry, |
| 1410 | * and so normally don't require allocations from the memcache. The |
| 1411 | * only exception to this is when dirty logging is enabled at runtime |
| 1412 | * and a write fault needs to collapse a block entry into a table. |
| 1413 | */ |
| 1414 | if (!fault_is_perm || (logging_active && write_fault)) { |
| 1415 | ret = kvm_mmu_topup_memory_cache(memcache, |
| 1416 | kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu)); |
| 1417 | if (ret) |
| 1418 | return ret; |
| 1419 | } |
| 1420 | |
| 1421 | /* |
| 1422 | * Let's check if we will get back a huge page backed by hugetlbfs, or |
| 1423 | * get block mapping for device MMIO region. |
| 1424 | */ |
| 1425 | mmap_read_lock(current->mm); |
| 1426 | vma = vma_lookup(current->mm, hva); |
| 1427 | if (unlikely(!vma)) { |
| 1428 | kvm_err("Failed to find VMA for hva 0x%lx\n", hva); |
| 1429 | mmap_read_unlock(current->mm); |
| 1430 | return -EFAULT; |
| 1431 | } |
| 1432 | |
| 1433 | /* |
| 1434 | * logging_active is guaranteed to never be true for VM_PFNMAP |
| 1435 | * memslots. |
| 1436 | */ |
| 1437 | if (logging_active) { |
| 1438 | force_pte = true; |
| 1439 | vma_shift = PAGE_SHIFT; |
| 1440 | } else { |
| 1441 | vma_shift = get_vma_page_shift(vma, hva); |
| 1442 | } |
| 1443 | |
| 1444 | switch (vma_shift) { |
| 1445 | #ifndef __PAGETABLE_PMD_FOLDED |
| 1446 | case PUD_SHIFT: |
| 1447 | if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE)) |
| 1448 | break; |
| 1449 | fallthrough; |
| 1450 | #endif |
| 1451 | case CONT_PMD_SHIFT: |
| 1452 | vma_shift = PMD_SHIFT; |
| 1453 | fallthrough; |
| 1454 | case PMD_SHIFT: |
| 1455 | if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) |
| 1456 | break; |
| 1457 | fallthrough; |
| 1458 | case CONT_PTE_SHIFT: |
| 1459 | vma_shift = PAGE_SHIFT; |
| 1460 | force_pte = true; |
| 1461 | fallthrough; |
| 1462 | case PAGE_SHIFT: |
| 1463 | break; |
| 1464 | default: |
| 1465 | WARN_ONCE(1, "Unknown vma_shift %d", vma_shift); |
| 1466 | } |
| 1467 | |
| 1468 | vma_pagesize = 1UL << vma_shift; |
| 1469 | if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE) |
| 1470 | fault_ipa &= ~(vma_pagesize - 1); |
| 1471 | |
| 1472 | gfn = fault_ipa >> PAGE_SHIFT; |
| 1473 | mte_allowed = kvm_vma_mte_allowed(vma); |
| 1474 | |
| 1475 | vfio_allow_any_uc = vma->vm_flags & VM_ALLOW_ANY_UNCACHED; |
| 1476 | |
| 1477 | /* Don't use the VMA after the unlock -- it may have vanished */ |
| 1478 | vma = NULL; |
| 1479 | |
| 1480 | /* |
| 1481 | * Read mmu_invalidate_seq so that KVM can detect if the results of |
| 1482 | * vma_lookup() or __gfn_to_pfn_memslot() become stale prior to |
| 1483 | * acquiring kvm->mmu_lock. |
| 1484 | * |
| 1485 | * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs |
| 1486 | * with the smp_wmb() in kvm_mmu_invalidate_end(). |
| 1487 | */ |
| 1488 | mmu_seq = vcpu->kvm->mmu_invalidate_seq; |
| 1489 | mmap_read_unlock(current->mm); |
| 1490 | |
| 1491 | pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL, |
| 1492 | write_fault, &writable, NULL); |
| 1493 | if (pfn == KVM_PFN_ERR_HWPOISON) { |
| 1494 | kvm_send_hwpoison_signal(hva, vma_shift); |
| 1495 | return 0; |
| 1496 | } |
| 1497 | if (is_error_noslot_pfn(pfn)) |
| 1498 | return -EFAULT; |
| 1499 | |
| 1500 | if (kvm_is_device_pfn(pfn)) { |
| 1501 | /* |
| 1502 | * If the page was identified as device early by looking at |
| 1503 | * the VMA flags, vma_pagesize is already representing the |
| 1504 | * largest quantity we can map. If instead it was mapped |
| 1505 | * via gfn_to_pfn_prot(), vma_pagesize is set to PAGE_SIZE |
| 1506 | * and must not be upgraded. |
| 1507 | * |
| 1508 | * In both cases, we don't let transparent_hugepage_adjust() |
| 1509 | * change things at the last minute. |
| 1510 | */ |
| 1511 | device = true; |
| 1512 | } else if (logging_active && !write_fault) { |
| 1513 | /* |
| 1514 | * Only actually map the page as writable if this was a write |
| 1515 | * fault. |
| 1516 | */ |
| 1517 | writable = false; |
| 1518 | } |
| 1519 | |
| 1520 | if (exec_fault && device) |
| 1521 | return -ENOEXEC; |
| 1522 | |
| 1523 | read_lock(&kvm->mmu_lock); |
| 1524 | pgt = vcpu->arch.hw_mmu->pgt; |
| 1525 | if (mmu_invalidate_retry(kvm, mmu_seq)) |
| 1526 | goto out_unlock; |
| 1527 | |
| 1528 | /* |
| 1529 | * If we are not forced to use page mapping, check if we are |
| 1530 | * backed by a THP and thus use block mapping if possible. |
| 1531 | */ |
| 1532 | if (vma_pagesize == PAGE_SIZE && !(force_pte || device)) { |
| 1533 | if (fault_is_perm && fault_granule > PAGE_SIZE) |
| 1534 | vma_pagesize = fault_granule; |
| 1535 | else |
| 1536 | vma_pagesize = transparent_hugepage_adjust(kvm, memslot, |
| 1537 | hva, &pfn, |
| 1538 | &fault_ipa); |
| 1539 | |
| 1540 | if (vma_pagesize < 0) { |
| 1541 | ret = vma_pagesize; |
| 1542 | goto out_unlock; |
| 1543 | } |
| 1544 | } |
| 1545 | |
| 1546 | if (!fault_is_perm && !device && kvm_has_mte(kvm)) { |
| 1547 | /* Check the VMM hasn't introduced a new disallowed VMA */ |
| 1548 | if (mte_allowed) { |
| 1549 | sanitise_mte_tags(kvm, pfn, vma_pagesize); |
| 1550 | } else { |
| 1551 | ret = -EFAULT; |
| 1552 | goto out_unlock; |
| 1553 | } |
| 1554 | } |
| 1555 | |
| 1556 | if (writable) |
| 1557 | prot |= KVM_PGTABLE_PROT_W; |
| 1558 | |
| 1559 | if (exec_fault) |
| 1560 | prot |= KVM_PGTABLE_PROT_X; |
| 1561 | |
| 1562 | if (device) { |
| 1563 | if (vfio_allow_any_uc) |
| 1564 | prot |= KVM_PGTABLE_PROT_NORMAL_NC; |
| 1565 | else |
| 1566 | prot |= KVM_PGTABLE_PROT_DEVICE; |
| 1567 | } else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) { |
| 1568 | prot |= KVM_PGTABLE_PROT_X; |
| 1569 | } |
| 1570 | |
| 1571 | /* |
| 1572 | * Under the premise of getting a FSC_PERM fault, we just need to relax |
| 1573 | * permissions only if vma_pagesize equals fault_granule. Otherwise, |
| 1574 | * kvm_pgtable_stage2_map() should be called to change block size. |
| 1575 | */ |
| 1576 | if (fault_is_perm && vma_pagesize == fault_granule) |
| 1577 | ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot); |
| 1578 | else |
| 1579 | ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize, |
| 1580 | __pfn_to_phys(pfn), prot, |
| 1581 | memcache, |
| 1582 | KVM_PGTABLE_WALK_HANDLE_FAULT | |
| 1583 | KVM_PGTABLE_WALK_SHARED); |
| 1584 | |
| 1585 | /* Mark the page dirty only if the fault is handled successfully */ |
| 1586 | if (writable && !ret) { |
| 1587 | kvm_set_pfn_dirty(pfn); |
| 1588 | mark_page_dirty_in_slot(kvm, memslot, gfn); |
| 1589 | } |
| 1590 | |
| 1591 | out_unlock: |
| 1592 | read_unlock(&kvm->mmu_lock); |
| 1593 | kvm_release_pfn_clean(pfn); |
| 1594 | return ret != -EAGAIN ? ret : 0; |
| 1595 | } |
| 1596 | |
| 1597 | /* Resolve the access fault by making the page young again. */ |
| 1598 | static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) |
| 1599 | { |
| 1600 | kvm_pte_t pte; |
| 1601 | struct kvm_s2_mmu *mmu; |
| 1602 | |
| 1603 | trace_kvm_access_fault(fault_ipa); |
| 1604 | |
| 1605 | read_lock(&vcpu->kvm->mmu_lock); |
| 1606 | mmu = vcpu->arch.hw_mmu; |
| 1607 | pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa); |
| 1608 | read_unlock(&vcpu->kvm->mmu_lock); |
| 1609 | |
| 1610 | if (kvm_pte_valid(pte)) |
| 1611 | kvm_set_pfn_accessed(kvm_pte_to_pfn(pte)); |
| 1612 | } |
| 1613 | |
| 1614 | /** |
| 1615 | * kvm_handle_guest_abort - handles all 2nd stage aborts |
| 1616 | * @vcpu: the VCPU pointer |
| 1617 | * |
| 1618 | * Any abort that gets to the host is almost guaranteed to be caused by a |
| 1619 | * missing second stage translation table entry, which can mean that either the |
| 1620 | * guest simply needs more memory and we must allocate an appropriate page or it |
| 1621 | * can mean that the guest tried to access I/O memory, which is emulated by user |
| 1622 | * space. The distinction is based on the IPA causing the fault and whether this |
| 1623 | * memory region has been registered as standard RAM by user space. |
| 1624 | */ |
| 1625 | int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) |
| 1626 | { |
| 1627 | unsigned long esr; |
| 1628 | phys_addr_t fault_ipa; |
| 1629 | struct kvm_memory_slot *memslot; |
| 1630 | unsigned long hva; |
| 1631 | bool is_iabt, write_fault, writable; |
| 1632 | gfn_t gfn; |
| 1633 | int ret, idx; |
| 1634 | |
| 1635 | esr = kvm_vcpu_get_esr(vcpu); |
| 1636 | |
| 1637 | fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); |
| 1638 | is_iabt = kvm_vcpu_trap_is_iabt(vcpu); |
| 1639 | |
| 1640 | if (esr_fsc_is_translation_fault(esr)) { |
| 1641 | /* Beyond sanitised PARange (which is the IPA limit) */ |
| 1642 | if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit())) { |
| 1643 | kvm_inject_size_fault(vcpu); |
| 1644 | return 1; |
| 1645 | } |
| 1646 | |
| 1647 | /* Falls between the IPA range and the PARange? */ |
| 1648 | if (fault_ipa >= BIT_ULL(vcpu->arch.hw_mmu->pgt->ia_bits)) { |
| 1649 | fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); |
| 1650 | |
| 1651 | if (is_iabt) |
| 1652 | kvm_inject_pabt(vcpu, fault_ipa); |
| 1653 | else |
| 1654 | kvm_inject_dabt(vcpu, fault_ipa); |
| 1655 | return 1; |
| 1656 | } |
| 1657 | } |
| 1658 | |
| 1659 | /* Synchronous External Abort? */ |
| 1660 | if (kvm_vcpu_abt_issea(vcpu)) { |
| 1661 | /* |
| 1662 | * For RAS the host kernel may handle this abort. |
| 1663 | * There is no need to pass the error into the guest. |
| 1664 | */ |
| 1665 | if (kvm_handle_guest_sea(fault_ipa, kvm_vcpu_get_esr(vcpu))) |
| 1666 | kvm_inject_vabt(vcpu); |
| 1667 | |
| 1668 | return 1; |
| 1669 | } |
| 1670 | |
| 1671 | trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu), |
| 1672 | kvm_vcpu_get_hfar(vcpu), fault_ipa); |
| 1673 | |
| 1674 | /* Check the stage-2 fault is trans. fault or write fault */ |
| 1675 | if (!esr_fsc_is_translation_fault(esr) && |
| 1676 | !esr_fsc_is_permission_fault(esr) && |
| 1677 | !esr_fsc_is_access_flag_fault(esr)) { |
| 1678 | kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n", |
| 1679 | kvm_vcpu_trap_get_class(vcpu), |
| 1680 | (unsigned long)kvm_vcpu_trap_get_fault(vcpu), |
| 1681 | (unsigned long)kvm_vcpu_get_esr(vcpu)); |
| 1682 | return -EFAULT; |
| 1683 | } |
| 1684 | |
| 1685 | idx = srcu_read_lock(&vcpu->kvm->srcu); |
| 1686 | |
| 1687 | gfn = fault_ipa >> PAGE_SHIFT; |
| 1688 | memslot = gfn_to_memslot(vcpu->kvm, gfn); |
| 1689 | hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable); |
| 1690 | write_fault = kvm_is_write_fault(vcpu); |
| 1691 | if (kvm_is_error_hva(hva) || (write_fault && !writable)) { |
| 1692 | /* |
| 1693 | * The guest has put either its instructions or its page-tables |
| 1694 | * somewhere it shouldn't have. Userspace won't be able to do |
| 1695 | * anything about this (there's no syndrome for a start), so |
| 1696 | * re-inject the abort back into the guest. |
| 1697 | */ |
| 1698 | if (is_iabt) { |
| 1699 | ret = -ENOEXEC; |
| 1700 | goto out; |
| 1701 | } |
| 1702 | |
| 1703 | if (kvm_vcpu_abt_iss1tw(vcpu)) { |
| 1704 | kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); |
| 1705 | ret = 1; |
| 1706 | goto out_unlock; |
| 1707 | } |
| 1708 | |
| 1709 | /* |
| 1710 | * Check for a cache maintenance operation. Since we |
| 1711 | * ended-up here, we know it is outside of any memory |
| 1712 | * slot. But we can't find out if that is for a device, |
| 1713 | * or if the guest is just being stupid. The only thing |
| 1714 | * we know for sure is that this range cannot be cached. |
| 1715 | * |
| 1716 | * So let's assume that the guest is just being |
| 1717 | * cautious, and skip the instruction. |
| 1718 | */ |
| 1719 | if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) { |
| 1720 | kvm_incr_pc(vcpu); |
| 1721 | ret = 1; |
| 1722 | goto out_unlock; |
| 1723 | } |
| 1724 | |
| 1725 | /* |
| 1726 | * The IPA is reported as [MAX:12], so we need to |
| 1727 | * complement it with the bottom 12 bits from the |
| 1728 | * faulting VA. This is always 12 bits, irrespective |
| 1729 | * of the page size. |
| 1730 | */ |
| 1731 | fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1); |
| 1732 | ret = io_mem_abort(vcpu, fault_ipa); |
| 1733 | goto out_unlock; |
| 1734 | } |
| 1735 | |
| 1736 | /* Userspace should not be able to register out-of-bounds IPAs */ |
| 1737 | VM_BUG_ON(fault_ipa >= kvm_phys_size(vcpu->arch.hw_mmu)); |
| 1738 | |
| 1739 | if (esr_fsc_is_access_flag_fault(esr)) { |
| 1740 | handle_access_fault(vcpu, fault_ipa); |
| 1741 | ret = 1; |
| 1742 | goto out_unlock; |
| 1743 | } |
| 1744 | |
| 1745 | ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, |
| 1746 | esr_fsc_is_permission_fault(esr)); |
| 1747 | if (ret == 0) |
| 1748 | ret = 1; |
| 1749 | out: |
| 1750 | if (ret == -ENOEXEC) { |
| 1751 | kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); |
| 1752 | ret = 1; |
| 1753 | } |
| 1754 | out_unlock: |
| 1755 | srcu_read_unlock(&vcpu->kvm->srcu, idx); |
| 1756 | return ret; |
| 1757 | } |
| 1758 | |
| 1759 | bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) |
| 1760 | { |
| 1761 | if (!kvm->arch.mmu.pgt) |
| 1762 | return false; |
| 1763 | |
| 1764 | __unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT, |
| 1765 | (range->end - range->start) << PAGE_SHIFT, |
| 1766 | range->may_block); |
| 1767 | |
| 1768 | return false; |
| 1769 | } |
| 1770 | |
| 1771 | bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| 1772 | { |
| 1773 | kvm_pfn_t pfn = pte_pfn(range->arg.pte); |
| 1774 | |
| 1775 | if (!kvm->arch.mmu.pgt) |
| 1776 | return false; |
| 1777 | |
| 1778 | WARN_ON(range->end - range->start != 1); |
| 1779 | |
| 1780 | /* |
| 1781 | * If the page isn't tagged, defer to user_mem_abort() for sanitising |
| 1782 | * the MTE tags. The S2 pte should have been unmapped by |
| 1783 | * mmu_notifier_invalidate_range_end(). |
| 1784 | */ |
| 1785 | if (kvm_has_mte(kvm) && !page_mte_tagged(pfn_to_page(pfn))) |
| 1786 | return false; |
| 1787 | |
| 1788 | /* |
| 1789 | * We've moved a page around, probably through CoW, so let's treat |
| 1790 | * it just like a translation fault and the map handler will clean |
| 1791 | * the cache to the PoC. |
| 1792 | * |
| 1793 | * The MMU notifiers will have unmapped a huge PMD before calling |
| 1794 | * ->change_pte() (which in turn calls kvm_set_spte_gfn()) and |
| 1795 | * therefore we never need to clear out a huge PMD through this |
| 1796 | * calling path and a memcache is not required. |
| 1797 | */ |
| 1798 | kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, range->start << PAGE_SHIFT, |
| 1799 | PAGE_SIZE, __pfn_to_phys(pfn), |
| 1800 | KVM_PGTABLE_PROT_R, NULL, 0); |
| 1801 | |
| 1802 | return false; |
| 1803 | } |
| 1804 | |
| 1805 | bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| 1806 | { |
| 1807 | u64 size = (range->end - range->start) << PAGE_SHIFT; |
| 1808 | |
| 1809 | if (!kvm->arch.mmu.pgt) |
| 1810 | return false; |
| 1811 | |
| 1812 | return kvm_pgtable_stage2_test_clear_young(kvm->arch.mmu.pgt, |
| 1813 | range->start << PAGE_SHIFT, |
| 1814 | size, true); |
| 1815 | } |
| 1816 | |
| 1817 | bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| 1818 | { |
| 1819 | u64 size = (range->end - range->start) << PAGE_SHIFT; |
| 1820 | |
| 1821 | if (!kvm->arch.mmu.pgt) |
| 1822 | return false; |
| 1823 | |
| 1824 | return kvm_pgtable_stage2_test_clear_young(kvm->arch.mmu.pgt, |
| 1825 | range->start << PAGE_SHIFT, |
| 1826 | size, false); |
| 1827 | } |
| 1828 | |
| 1829 | phys_addr_t kvm_mmu_get_httbr(void) |
| 1830 | { |
| 1831 | return __pa(hyp_pgtable->pgd); |
| 1832 | } |
| 1833 | |
| 1834 | phys_addr_t kvm_get_idmap_vector(void) |
| 1835 | { |
| 1836 | return hyp_idmap_vector; |
| 1837 | } |
| 1838 | |
| 1839 | static int kvm_map_idmap_text(void) |
| 1840 | { |
| 1841 | unsigned long size = hyp_idmap_end - hyp_idmap_start; |
| 1842 | int err = __create_hyp_mappings(hyp_idmap_start, size, hyp_idmap_start, |
| 1843 | PAGE_HYP_EXEC); |
| 1844 | if (err) |
| 1845 | kvm_err("Failed to idmap %lx-%lx\n", |
| 1846 | hyp_idmap_start, hyp_idmap_end); |
| 1847 | |
| 1848 | return err; |
| 1849 | } |
| 1850 | |
| 1851 | static void *kvm_hyp_zalloc_page(void *arg) |
| 1852 | { |
| 1853 | return (void *)get_zeroed_page(GFP_KERNEL); |
| 1854 | } |
| 1855 | |
| 1856 | static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = { |
| 1857 | .zalloc_page = kvm_hyp_zalloc_page, |
| 1858 | .get_page = kvm_host_get_page, |
| 1859 | .put_page = kvm_host_put_page, |
| 1860 | .phys_to_virt = kvm_host_va, |
| 1861 | .virt_to_phys = kvm_host_pa, |
| 1862 | }; |
| 1863 | |
| 1864 | int __init kvm_mmu_init(u32 *hyp_va_bits) |
| 1865 | { |
| 1866 | int err; |
| 1867 | u32 idmap_bits; |
| 1868 | u32 kernel_bits; |
| 1869 | |
| 1870 | hyp_idmap_start = __pa_symbol(__hyp_idmap_text_start); |
| 1871 | hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE); |
| 1872 | hyp_idmap_end = __pa_symbol(__hyp_idmap_text_end); |
| 1873 | hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE); |
| 1874 | hyp_idmap_vector = __pa_symbol(__kvm_hyp_init); |
| 1875 | |
| 1876 | /* |
| 1877 | * We rely on the linker script to ensure at build time that the HYP |
| 1878 | * init code does not cross a page boundary. |
| 1879 | */ |
| 1880 | BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK); |
| 1881 | |
| 1882 | /* |
| 1883 | * The ID map is always configured for 48 bits of translation, which |
| 1884 | * may be fewer than the number of VA bits used by the regular kernel |
| 1885 | * stage 1, when VA_BITS=52. |
| 1886 | * |
| 1887 | * At EL2, there is only one TTBR register, and we can't switch between |
| 1888 | * translation tables *and* update TCR_EL2.T0SZ at the same time. Bottom |
| 1889 | * line: we need to use the extended range with *both* our translation |
| 1890 | * tables. |
| 1891 | * |
| 1892 | * So use the maximum of the idmap VA bits and the regular kernel stage |
| 1893 | * 1 VA bits to assure that the hypervisor can both ID map its code page |
| 1894 | * and map any kernel memory. |
| 1895 | */ |
| 1896 | idmap_bits = IDMAP_VA_BITS; |
| 1897 | kernel_bits = vabits_actual; |
| 1898 | *hyp_va_bits = max(idmap_bits, kernel_bits); |
| 1899 | |
| 1900 | kvm_debug("Using %u-bit virtual addresses at EL2\n", *hyp_va_bits); |
| 1901 | kvm_debug("IDMAP page: %lx\n", hyp_idmap_start); |
| 1902 | kvm_debug("HYP VA range: %lx:%lx\n", |
| 1903 | kern_hyp_va(PAGE_OFFSET), |
| 1904 | kern_hyp_va((unsigned long)high_memory - 1)); |
| 1905 | |
| 1906 | if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) && |
| 1907 | hyp_idmap_start < kern_hyp_va((unsigned long)high_memory - 1) && |
| 1908 | hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) { |
| 1909 | /* |
| 1910 | * The idmap page is intersecting with the VA space, |
| 1911 | * it is not safe to continue further. |
| 1912 | */ |
| 1913 | kvm_err("IDMAP intersecting with HYP VA, unable to continue\n"); |
| 1914 | err = -EINVAL; |
| 1915 | goto out; |
| 1916 | } |
| 1917 | |
| 1918 | hyp_pgtable = kzalloc(sizeof(*hyp_pgtable), GFP_KERNEL); |
| 1919 | if (!hyp_pgtable) { |
| 1920 | kvm_err("Hyp mode page-table not allocated\n"); |
| 1921 | err = -ENOMEM; |
| 1922 | goto out; |
| 1923 | } |
| 1924 | |
| 1925 | err = kvm_pgtable_hyp_init(hyp_pgtable, *hyp_va_bits, &kvm_hyp_mm_ops); |
| 1926 | if (err) |
| 1927 | goto out_free_pgtable; |
| 1928 | |
| 1929 | err = kvm_map_idmap_text(); |
| 1930 | if (err) |
| 1931 | goto out_destroy_pgtable; |
| 1932 | |
| 1933 | io_map_base = hyp_idmap_start; |
| 1934 | return 0; |
| 1935 | |
| 1936 | out_destroy_pgtable: |
| 1937 | kvm_pgtable_hyp_destroy(hyp_pgtable); |
| 1938 | out_free_pgtable: |
| 1939 | kfree(hyp_pgtable); |
| 1940 | hyp_pgtable = NULL; |
| 1941 | out: |
| 1942 | return err; |
| 1943 | } |
| 1944 | |
| 1945 | void kvm_arch_commit_memory_region(struct kvm *kvm, |
| 1946 | struct kvm_memory_slot *old, |
| 1947 | const struct kvm_memory_slot *new, |
| 1948 | enum kvm_mr_change change) |
| 1949 | { |
| 1950 | bool log_dirty_pages = new && new->flags & KVM_MEM_LOG_DIRTY_PAGES; |
| 1951 | |
| 1952 | /* |
| 1953 | * At this point memslot has been committed and there is an |
| 1954 | * allocated dirty_bitmap[], dirty pages will be tracked while the |
| 1955 | * memory slot is write protected. |
| 1956 | */ |
| 1957 | if (log_dirty_pages) { |
| 1958 | |
| 1959 | if (change == KVM_MR_DELETE) |
| 1960 | return; |
| 1961 | |
| 1962 | /* |
| 1963 | * Huge and normal pages are write-protected and split |
| 1964 | * on either of these two cases: |
| 1965 | * |
| 1966 | * 1. with initial-all-set: gradually with CLEAR ioctls, |
| 1967 | */ |
| 1968 | if (kvm_dirty_log_manual_protect_and_init_set(kvm)) |
| 1969 | return; |
| 1970 | /* |
| 1971 | * or |
| 1972 | * 2. without initial-all-set: all in one shot when |
| 1973 | * enabling dirty logging. |
| 1974 | */ |
| 1975 | kvm_mmu_wp_memory_region(kvm, new->id); |
| 1976 | kvm_mmu_split_memory_region(kvm, new->id); |
| 1977 | } else { |
| 1978 | /* |
| 1979 | * Free any leftovers from the eager page splitting cache. Do |
| 1980 | * this when deleting, moving, disabling dirty logging, or |
| 1981 | * creating the memslot (a nop). Doing it for deletes makes |
| 1982 | * sure we don't leak memory, and there's no need to keep the |
| 1983 | * cache around for any of the other cases. |
| 1984 | */ |
| 1985 | kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache); |
| 1986 | } |
| 1987 | } |
| 1988 | |
| 1989 | int kvm_arch_prepare_memory_region(struct kvm *kvm, |
| 1990 | const struct kvm_memory_slot *old, |
| 1991 | struct kvm_memory_slot *new, |
| 1992 | enum kvm_mr_change change) |
| 1993 | { |
| 1994 | hva_t hva, reg_end; |
| 1995 | int ret = 0; |
| 1996 | |
| 1997 | if (change != KVM_MR_CREATE && change != KVM_MR_MOVE && |
| 1998 | change != KVM_MR_FLAGS_ONLY) |
| 1999 | return 0; |
| 2000 | |
| 2001 | /* |
| 2002 | * Prevent userspace from creating a memory region outside of the IPA |
| 2003 | * space addressable by the KVM guest IPA space. |
| 2004 | */ |
| 2005 | if ((new->base_gfn + new->npages) > (kvm_phys_size(&kvm->arch.mmu) >> PAGE_SHIFT)) |
| 2006 | return -EFAULT; |
| 2007 | |
| 2008 | hva = new->userspace_addr; |
| 2009 | reg_end = hva + (new->npages << PAGE_SHIFT); |
| 2010 | |
| 2011 | mmap_read_lock(current->mm); |
| 2012 | /* |
| 2013 | * A memory region could potentially cover multiple VMAs, and any holes |
| 2014 | * between them, so iterate over all of them. |
| 2015 | * |
| 2016 | * +--------------------------------------------+ |
| 2017 | * +---------------+----------------+ +----------------+ |
| 2018 | * | : VMA 1 | VMA 2 | | VMA 3 : | |
| 2019 | * +---------------+----------------+ +----------------+ |
| 2020 | * | memory region | |
| 2021 | * +--------------------------------------------+ |
| 2022 | */ |
| 2023 | do { |
| 2024 | struct vm_area_struct *vma; |
| 2025 | |
| 2026 | vma = find_vma_intersection(current->mm, hva, reg_end); |
| 2027 | if (!vma) |
| 2028 | break; |
| 2029 | |
| 2030 | if (kvm_has_mte(kvm) && !kvm_vma_mte_allowed(vma)) { |
| 2031 | ret = -EINVAL; |
| 2032 | break; |
| 2033 | } |
| 2034 | |
| 2035 | if (vma->vm_flags & VM_PFNMAP) { |
| 2036 | /* IO region dirty page logging not allowed */ |
| 2037 | if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) { |
| 2038 | ret = -EINVAL; |
| 2039 | break; |
| 2040 | } |
| 2041 | } |
| 2042 | hva = min(reg_end, vma->vm_end); |
| 2043 | } while (hva < reg_end); |
| 2044 | |
| 2045 | mmap_read_unlock(current->mm); |
| 2046 | return ret; |
| 2047 | } |
| 2048 | |
| 2049 | void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) |
| 2050 | { |
| 2051 | } |
| 2052 | |
| 2053 | void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) |
| 2054 | { |
| 2055 | } |
| 2056 | |
| 2057 | void kvm_arch_flush_shadow_all(struct kvm *kvm) |
| 2058 | { |
| 2059 | kvm_uninit_stage2_mmu(kvm); |
| 2060 | } |
| 2061 | |
| 2062 | void kvm_arch_flush_shadow_memslot(struct kvm *kvm, |
| 2063 | struct kvm_memory_slot *slot) |
| 2064 | { |
| 2065 | gpa_t gpa = slot->base_gfn << PAGE_SHIFT; |
| 2066 | phys_addr_t size = slot->npages << PAGE_SHIFT; |
| 2067 | |
| 2068 | write_lock(&kvm->mmu_lock); |
| 2069 | unmap_stage2_range(&kvm->arch.mmu, gpa, size); |
| 2070 | write_unlock(&kvm->mmu_lock); |
| 2071 | } |
| 2072 | |
| 2073 | /* |
| 2074 | * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized). |
| 2075 | * |
| 2076 | * Main problems: |
| 2077 | * - S/W ops are local to a CPU (not broadcast) |
| 2078 | * - We have line migration behind our back (speculation) |
| 2079 | * - System caches don't support S/W at all (damn!) |
| 2080 | * |
| 2081 | * In the face of the above, the best we can do is to try and convert |
| 2082 | * S/W ops to VA ops. Because the guest is not allowed to infer the |
| 2083 | * S/W to PA mapping, it can only use S/W to nuke the whole cache, |
| 2084 | * which is a rather good thing for us. |
| 2085 | * |
| 2086 | * Also, it is only used when turning caches on/off ("The expected |
| 2087 | * usage of the cache maintenance instructions that operate by set/way |
| 2088 | * is associated with the cache maintenance instructions associated |
| 2089 | * with the powerdown and powerup of caches, if this is required by |
| 2090 | * the implementation."). |
| 2091 | * |
| 2092 | * We use the following policy: |
| 2093 | * |
| 2094 | * - If we trap a S/W operation, we enable VM trapping to detect |
| 2095 | * caches being turned on/off, and do a full clean. |
| 2096 | * |
| 2097 | * - We flush the caches on both caches being turned on and off. |
| 2098 | * |
| 2099 | * - Once the caches are enabled, we stop trapping VM ops. |
| 2100 | */ |
| 2101 | void kvm_set_way_flush(struct kvm_vcpu *vcpu) |
| 2102 | { |
| 2103 | unsigned long hcr = *vcpu_hcr(vcpu); |
| 2104 | |
| 2105 | /* |
| 2106 | * If this is the first time we do a S/W operation |
| 2107 | * (i.e. HCR_TVM not set) flush the whole memory, and set the |
| 2108 | * VM trapping. |
| 2109 | * |
| 2110 | * Otherwise, rely on the VM trapping to wait for the MMU + |
| 2111 | * Caches to be turned off. At that point, we'll be able to |
| 2112 | * clean the caches again. |
| 2113 | */ |
| 2114 | if (!(hcr & HCR_TVM)) { |
| 2115 | trace_kvm_set_way_flush(*vcpu_pc(vcpu), |
| 2116 | vcpu_has_cache_enabled(vcpu)); |
| 2117 | stage2_flush_vm(vcpu->kvm); |
| 2118 | *vcpu_hcr(vcpu) = hcr | HCR_TVM; |
| 2119 | } |
| 2120 | } |
| 2121 | |
| 2122 | void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled) |
| 2123 | { |
| 2124 | bool now_enabled = vcpu_has_cache_enabled(vcpu); |
| 2125 | |
| 2126 | /* |
| 2127 | * If switching the MMU+caches on, need to invalidate the caches. |
| 2128 | * If switching it off, need to clean the caches. |
| 2129 | * Clean + invalidate does the trick always. |
| 2130 | */ |
| 2131 | if (now_enabled != was_enabled) |
| 2132 | stage2_flush_vm(vcpu->kvm); |
| 2133 | |
| 2134 | /* Caches are now on, stop trapping VM ops (until a S/W op) */ |
| 2135 | if (now_enabled) |
| 2136 | *vcpu_hcr(vcpu) &= ~HCR_TVM; |
| 2137 | |
| 2138 | trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled); |
| 2139 | } |