1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License, version 2, as 4 * published by the Free Software Foundation. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 * You should have received a copy of the GNU General Public License 12 * along with this program; if not, write to the Free Software 13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 14 * 15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 16 * Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com> 17 * Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com> 18 */ 19 20 #include <linux/types.h> 21 #include <linux/string.h> 22 #include <linux/kvm.h> 23 #include <linux/kvm_host.h> 24 #include <linux/highmem.h> 25 #include <linux/gfp.h> 26 #include <linux/slab.h> 27 #include <linux/sched/signal.h> 28 #include <linux/hugetlb.h> 29 #include <linux/list.h> 30 #include <linux/anon_inodes.h> 31 #include <linux/iommu.h> 32 #include <linux/file.h> 33 34 #include <asm/kvm_ppc.h> 35 #include <asm/kvm_book3s.h> 36 #include <asm/book3s/64/mmu-hash.h> 37 #include <asm/hvcall.h> 38 #include <asm/synch.h> 39 #include <asm/ppc-opcode.h> 40 #include <asm/kvm_host.h> 41 #include <asm/udbg.h> 42 #include <asm/iommu.h> 43 #include <asm/tce.h> 44 #include <asm/mmu_context.h> 45 46 static unsigned long kvmppc_tce_pages(unsigned long iommu_pages) 47 { 48 return ALIGN(iommu_pages * sizeof(u64), PAGE_SIZE) / PAGE_SIZE; 49 } 50 51 static unsigned long kvmppc_stt_pages(unsigned long tce_pages) 52 { 53 unsigned long stt_bytes = sizeof(struct kvmppc_spapr_tce_table) + 54 (tce_pages * sizeof(struct page *)); 55 56 return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE; 57 } 58 59 static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc) 60 { 61 long ret = 0; 62 63 if (!current || !current->mm) 64 return ret; /* process exited */ 65 66 down_write(¤t->mm->mmap_sem); 67 68 if (inc) { 69 unsigned long locked, lock_limit; 70 71 locked = current->mm->locked_vm + stt_pages; 72 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 73 if (locked > lock_limit && !capable(CAP_IPC_LOCK)) 74 ret = -ENOMEM; 75 else 76 current->mm->locked_vm += stt_pages; 77 } else { 78 if (WARN_ON_ONCE(stt_pages > current->mm->locked_vm)) 79 stt_pages = current->mm->locked_vm; 80 81 current->mm->locked_vm -= stt_pages; 82 } 83 84 pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid, 85 inc ? '+' : '-', 86 stt_pages << PAGE_SHIFT, 87 current->mm->locked_vm << PAGE_SHIFT, 88 rlimit(RLIMIT_MEMLOCK), 89 ret ? " - exceeded" : ""); 90 91 up_write(¤t->mm->mmap_sem); 92 93 return ret; 94 } 95 96 static void kvm_spapr_tce_iommu_table_free(struct rcu_head *head) 97 { 98 struct kvmppc_spapr_tce_iommu_table *stit = container_of(head, 99 struct kvmppc_spapr_tce_iommu_table, rcu); 100 101 iommu_tce_table_put(stit->tbl); 102 103 kfree(stit); 104 } 105 106 static void kvm_spapr_tce_liobn_put(struct kref *kref) 107 { 108 struct kvmppc_spapr_tce_iommu_table *stit = container_of(kref, 109 struct kvmppc_spapr_tce_iommu_table, kref); 110 111 list_del_rcu(&stit->next); 112 113 call_rcu(&stit->rcu, kvm_spapr_tce_iommu_table_free); 114 } 115 116 extern void kvm_spapr_tce_release_iommu_group(struct kvm *kvm, 117 struct iommu_group *grp) 118 { 119 int i; 120 struct kvmppc_spapr_tce_table *stt; 121 struct kvmppc_spapr_tce_iommu_table *stit, *tmp; 122 struct iommu_table_group *table_group = NULL; 123 124 list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) { 125 126 table_group = iommu_group_get_iommudata(grp); 127 if (WARN_ON(!table_group)) 128 continue; 129 130 list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) { 131 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { 132 if (table_group->tables[i] != stit->tbl) 133 continue; 134 135 kref_put(&stit->kref, kvm_spapr_tce_liobn_put); 136 } 137 } 138 } 139 } 140 141 extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd, 142 struct iommu_group *grp) 143 { 144 struct kvmppc_spapr_tce_table *stt = NULL; 145 bool found = false; 146 struct iommu_table *tbl = NULL; 147 struct iommu_table_group *table_group; 148 long i; 149 struct kvmppc_spapr_tce_iommu_table *stit; 150 struct fd f; 151 152 f = fdget(tablefd); 153 if (!f.file) 154 return -EBADF; 155 156 list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) { 157 if (stt == f.file->private_data) { 158 found = true; 159 break; 160 } 161 } 162 163 fdput(f); 164 165 if (!found) 166 return -EINVAL; 167 168 table_group = iommu_group_get_iommudata(grp); 169 if (WARN_ON(!table_group)) 170 return -EFAULT; 171 172 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { 173 struct iommu_table *tbltmp = table_group->tables[i]; 174 175 if (!tbltmp) 176 continue; 177 /* Make sure hardware table parameters are compatible */ 178 if ((tbltmp->it_page_shift <= stt->page_shift) && 179 (tbltmp->it_offset << tbltmp->it_page_shift == 180 stt->offset << stt->page_shift) && 181 (tbltmp->it_size << tbltmp->it_page_shift >= 182 stt->size << stt->page_shift)) { 183 /* 184 * Reference the table to avoid races with 185 * add/remove DMA windows. 186 */ 187 tbl = iommu_tce_table_get(tbltmp); 188 break; 189 } 190 } 191 if (!tbl) 192 return -EINVAL; 193 194 list_for_each_entry_rcu(stit, &stt->iommu_tables, next) { 195 if (tbl != stit->tbl) 196 continue; 197 198 if (!kref_get_unless_zero(&stit->kref)) { 199 /* stit is being destroyed */ 200 iommu_tce_table_put(tbl); 201 return -ENOTTY; 202 } 203 /* 204 * The table is already known to this KVM, we just increased 205 * its KVM reference counter and can return. 206 */ 207 return 0; 208 } 209 210 stit = kzalloc(sizeof(*stit), GFP_KERNEL); 211 if (!stit) { 212 iommu_tce_table_put(tbl); 213 return -ENOMEM; 214 } 215 216 stit->tbl = tbl; 217 kref_init(&stit->kref); 218 219 list_add_rcu(&stit->next, &stt->iommu_tables); 220 221 return 0; 222 } 223 224 static void release_spapr_tce_table(struct rcu_head *head) 225 { 226 struct kvmppc_spapr_tce_table *stt = container_of(head, 227 struct kvmppc_spapr_tce_table, rcu); 228 unsigned long i, npages = kvmppc_tce_pages(stt->size); 229 230 for (i = 0; i < npages; i++) 231 if (stt->pages[i]) 232 __free_page(stt->pages[i]); 233 234 kfree(stt); 235 } 236 237 static struct page *kvm_spapr_get_tce_page(struct kvmppc_spapr_tce_table *stt, 238 unsigned long sttpage) 239 { 240 struct page *page = stt->pages[sttpage]; 241 242 if (page) 243 return page; 244 245 mutex_lock(&stt->alloc_lock); 246 page = stt->pages[sttpage]; 247 if (!page) { 248 page = alloc_page(GFP_KERNEL | __GFP_ZERO); 249 WARN_ON_ONCE(!page); 250 if (page) 251 stt->pages[sttpage] = page; 252 } 253 mutex_unlock(&stt->alloc_lock); 254 255 return page; 256 } 257 258 static vm_fault_t kvm_spapr_tce_fault(struct vm_fault *vmf) 259 { 260 struct kvmppc_spapr_tce_table *stt = vmf->vma->vm_file->private_data; 261 struct page *page; 262 263 if (vmf->pgoff >= kvmppc_tce_pages(stt->size)) 264 return VM_FAULT_SIGBUS; 265 266 page = kvm_spapr_get_tce_page(stt, vmf->pgoff); 267 if (!page) 268 return VM_FAULT_OOM; 269 270 get_page(page); 271 vmf->page = page; 272 return 0; 273 } 274 275 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = { 276 .fault = kvm_spapr_tce_fault, 277 }; 278 279 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma) 280 { 281 vma->vm_ops = &kvm_spapr_tce_vm_ops; 282 return 0; 283 } 284 285 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp) 286 { 287 struct kvmppc_spapr_tce_table *stt = filp->private_data; 288 struct kvmppc_spapr_tce_iommu_table *stit, *tmp; 289 struct kvm *kvm = stt->kvm; 290 291 mutex_lock(&kvm->lock); 292 list_del_rcu(&stt->list); 293 mutex_unlock(&kvm->lock); 294 295 list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) { 296 WARN_ON(!kref_read(&stit->kref)); 297 while (1) { 298 if (kref_put(&stit->kref, kvm_spapr_tce_liobn_put)) 299 break; 300 } 301 } 302 303 kvm_put_kvm(stt->kvm); 304 305 kvmppc_account_memlimit( 306 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false); 307 call_rcu(&stt->rcu, release_spapr_tce_table); 308 309 return 0; 310 } 311 312 static const struct file_operations kvm_spapr_tce_fops = { 313 .mmap = kvm_spapr_tce_mmap, 314 .release = kvm_spapr_tce_release, 315 }; 316 317 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, 318 struct kvm_create_spapr_tce_64 *args) 319 { 320 struct kvmppc_spapr_tce_table *stt = NULL; 321 struct kvmppc_spapr_tce_table *siter; 322 unsigned long npages, size = args->size; 323 int ret = -ENOMEM; 324 325 if (!args->size || args->page_shift < 12 || args->page_shift > 34 || 326 (args->offset + args->size > (ULLONG_MAX >> args->page_shift))) 327 return -EINVAL; 328 329 npages = kvmppc_tce_pages(size); 330 ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true); 331 if (ret) 332 return ret; 333 334 ret = -ENOMEM; 335 stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *), 336 GFP_KERNEL); 337 if (!stt) 338 goto fail_acct; 339 340 stt->liobn = args->liobn; 341 stt->page_shift = args->page_shift; 342 stt->offset = args->offset; 343 stt->size = size; 344 stt->kvm = kvm; 345 mutex_init(&stt->alloc_lock); 346 INIT_LIST_HEAD_RCU(&stt->iommu_tables); 347 348 mutex_lock(&kvm->lock); 349 350 /* Check this LIOBN hasn't been previously allocated */ 351 ret = 0; 352 list_for_each_entry(siter, &kvm->arch.spapr_tce_tables, list) { 353 if (siter->liobn == args->liobn) { 354 ret = -EBUSY; 355 break; 356 } 357 } 358 359 kvm_get_kvm(kvm); 360 if (!ret) 361 ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops, 362 stt, O_RDWR | O_CLOEXEC); 363 364 if (ret >= 0) 365 list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables); 366 else 367 kvm_put_kvm(kvm); 368 369 mutex_unlock(&kvm->lock); 370 371 if (ret >= 0) 372 return ret; 373 374 kfree(stt); 375 fail_acct: 376 kvmppc_account_memlimit(kvmppc_stt_pages(npages), false); 377 return ret; 378 } 379 380 static long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce, 381 unsigned long *ua) 382 { 383 unsigned long gfn = tce >> PAGE_SHIFT; 384 struct kvm_memory_slot *memslot; 385 386 memslot = search_memslots(kvm_memslots(kvm), gfn); 387 if (!memslot) 388 return -EINVAL; 389 390 *ua = __gfn_to_hva_memslot(memslot, gfn) | 391 (tce & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE)); 392 393 return 0; 394 } 395 396 static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, 397 unsigned long tce) 398 { 399 unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE); 400 enum dma_data_direction dir = iommu_tce_direction(tce); 401 struct kvmppc_spapr_tce_iommu_table *stit; 402 unsigned long ua = 0; 403 404 /* Allow userspace to poison TCE table */ 405 if (dir == DMA_NONE) 406 return H_SUCCESS; 407 408 if (iommu_tce_check_gpa(stt->page_shift, gpa)) 409 return H_TOO_HARD; 410 411 if (kvmppc_tce_to_ua(stt->kvm, tce, &ua)) 412 return H_TOO_HARD; 413 414 list_for_each_entry_rcu(stit, &stt->iommu_tables, next) { 415 unsigned long hpa = 0; 416 struct mm_iommu_table_group_mem_t *mem; 417 long shift = stit->tbl->it_page_shift; 418 419 mem = mm_iommu_lookup(stt->kvm->mm, ua, 1ULL << shift); 420 if (!mem) 421 return H_TOO_HARD; 422 423 if (mm_iommu_ua_to_hpa(mem, ua, shift, &hpa)) 424 return H_TOO_HARD; 425 } 426 427 return H_SUCCESS; 428 } 429 430 /* 431 * Handles TCE requests for emulated devices. 432 * Puts guest TCE values to the table and expects user space to convert them. 433 * Cannot fail so kvmppc_tce_validate must be called before it. 434 */ 435 static void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt, 436 unsigned long idx, unsigned long tce) 437 { 438 struct page *page; 439 u64 *tbl; 440 unsigned long sttpage; 441 442 idx -= stt->offset; 443 sttpage = idx / TCES_PER_PAGE; 444 page = stt->pages[sttpage]; 445 446 if (!page) { 447 /* We allow any TCE, not just with read|write permissions */ 448 if (!tce) 449 return; 450 451 page = kvm_spapr_get_tce_page(stt, sttpage); 452 if (!page) 453 return; 454 } 455 tbl = page_to_virt(page); 456 457 tbl[idx % TCES_PER_PAGE] = tce; 458 } 459 460 static void kvmppc_clear_tce(struct mm_struct *mm, struct iommu_table *tbl, 461 unsigned long entry) 462 { 463 unsigned long hpa = 0; 464 enum dma_data_direction dir = DMA_NONE; 465 466 iommu_tce_xchg(mm, tbl, entry, &hpa, &dir); 467 } 468 469 static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm, 470 struct iommu_table *tbl, unsigned long entry) 471 { 472 struct mm_iommu_table_group_mem_t *mem = NULL; 473 const unsigned long pgsize = 1ULL << tbl->it_page_shift; 474 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry); 475 476 if (!pua) 477 return H_SUCCESS; 478 479 mem = mm_iommu_lookup(kvm->mm, be64_to_cpu(*pua), pgsize); 480 if (!mem) 481 return H_TOO_HARD; 482 483 mm_iommu_mapped_dec(mem); 484 485 *pua = cpu_to_be64(0); 486 487 return H_SUCCESS; 488 } 489 490 static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm, 491 struct iommu_table *tbl, unsigned long entry) 492 { 493 enum dma_data_direction dir = DMA_NONE; 494 unsigned long hpa = 0; 495 long ret; 496 497 if (WARN_ON_ONCE(iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir))) 498 return H_TOO_HARD; 499 500 if (dir == DMA_NONE) 501 return H_SUCCESS; 502 503 ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry); 504 if (ret != H_SUCCESS) 505 iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir); 506 507 return ret; 508 } 509 510 static long kvmppc_tce_iommu_unmap(struct kvm *kvm, 511 struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl, 512 unsigned long entry) 513 { 514 unsigned long i, ret = H_SUCCESS; 515 unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift); 516 unsigned long io_entry = entry * subpages; 517 518 for (i = 0; i < subpages; ++i) { 519 ret = kvmppc_tce_iommu_do_unmap(kvm, tbl, io_entry + i); 520 if (ret != H_SUCCESS) 521 break; 522 } 523 524 return ret; 525 } 526 527 long kvmppc_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl, 528 unsigned long entry, unsigned long ua, 529 enum dma_data_direction dir) 530 { 531 long ret; 532 unsigned long hpa; 533 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry); 534 struct mm_iommu_table_group_mem_t *mem; 535 536 if (!pua) 537 /* it_userspace allocation might be delayed */ 538 return H_TOO_HARD; 539 540 mem = mm_iommu_lookup(kvm->mm, ua, 1ULL << tbl->it_page_shift); 541 if (!mem) 542 /* This only handles v2 IOMMU type, v1 is handled via ioctl() */ 543 return H_TOO_HARD; 544 545 if (WARN_ON_ONCE(mm_iommu_ua_to_hpa(mem, ua, tbl->it_page_shift, &hpa))) 546 return H_TOO_HARD; 547 548 if (mm_iommu_mapped_inc(mem)) 549 return H_TOO_HARD; 550 551 ret = iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir); 552 if (WARN_ON_ONCE(ret)) { 553 mm_iommu_mapped_dec(mem); 554 return H_TOO_HARD; 555 } 556 557 if (dir != DMA_NONE) 558 kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry); 559 560 *pua = cpu_to_be64(ua); 561 562 return 0; 563 } 564 565 static long kvmppc_tce_iommu_map(struct kvm *kvm, 566 struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl, 567 unsigned long entry, unsigned long ua, 568 enum dma_data_direction dir) 569 { 570 unsigned long i, pgoff, ret = H_SUCCESS; 571 unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift); 572 unsigned long io_entry = entry * subpages; 573 574 for (i = 0, pgoff = 0; i < subpages; 575 ++i, pgoff += IOMMU_PAGE_SIZE(tbl)) { 576 577 ret = kvmppc_tce_iommu_do_map(kvm, tbl, 578 io_entry + i, ua + pgoff, dir); 579 if (ret != H_SUCCESS) 580 break; 581 } 582 583 return ret; 584 } 585 586 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, 587 unsigned long ioba, unsigned long tce) 588 { 589 struct kvmppc_spapr_tce_table *stt; 590 long ret, idx; 591 struct kvmppc_spapr_tce_iommu_table *stit; 592 unsigned long entry, ua = 0; 593 enum dma_data_direction dir; 594 595 /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */ 596 /* liobn, ioba, tce); */ 597 598 stt = kvmppc_find_table(vcpu->kvm, liobn); 599 if (!stt) 600 return H_TOO_HARD; 601 602 ret = kvmppc_ioba_validate(stt, ioba, 1); 603 if (ret != H_SUCCESS) 604 return ret; 605 606 idx = srcu_read_lock(&vcpu->kvm->srcu); 607 608 ret = kvmppc_tce_validate(stt, tce); 609 if (ret != H_SUCCESS) 610 goto unlock_exit; 611 612 dir = iommu_tce_direction(tce); 613 614 if ((dir != DMA_NONE) && kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) { 615 ret = H_PARAMETER; 616 goto unlock_exit; 617 } 618 619 entry = ioba >> stt->page_shift; 620 621 list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { 622 if (dir == DMA_NONE) 623 ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt, 624 stit->tbl, entry); 625 else 626 ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, stit->tbl, 627 entry, ua, dir); 628 629 if (ret != H_SUCCESS) { 630 kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry); 631 goto unlock_exit; 632 } 633 } 634 635 kvmppc_tce_put(stt, entry, tce); 636 637 unlock_exit: 638 srcu_read_unlock(&vcpu->kvm->srcu, idx); 639 640 return ret; 641 } 642 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce); 643 644 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, 645 unsigned long liobn, unsigned long ioba, 646 unsigned long tce_list, unsigned long npages) 647 { 648 struct kvmppc_spapr_tce_table *stt; 649 long i, ret = H_SUCCESS, idx; 650 unsigned long entry, ua = 0; 651 u64 __user *tces; 652 u64 tce; 653 struct kvmppc_spapr_tce_iommu_table *stit; 654 655 stt = kvmppc_find_table(vcpu->kvm, liobn); 656 if (!stt) 657 return H_TOO_HARD; 658 659 entry = ioba >> stt->page_shift; 660 /* 661 * SPAPR spec says that the maximum size of the list is 512 TCEs 662 * so the whole table fits in 4K page 663 */ 664 if (npages > 512) 665 return H_PARAMETER; 666 667 if (tce_list & (SZ_4K - 1)) 668 return H_PARAMETER; 669 670 ret = kvmppc_ioba_validate(stt, ioba, npages); 671 if (ret != H_SUCCESS) 672 return ret; 673 674 idx = srcu_read_lock(&vcpu->kvm->srcu); 675 if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua)) { 676 ret = H_TOO_HARD; 677 goto unlock_exit; 678 } 679 tces = (u64 __user *) ua; 680 681 for (i = 0; i < npages; ++i) { 682 if (get_user(tce, tces + i)) { 683 ret = H_TOO_HARD; 684 goto unlock_exit; 685 } 686 tce = be64_to_cpu(tce); 687 688 ret = kvmppc_tce_validate(stt, tce); 689 if (ret != H_SUCCESS) 690 goto unlock_exit; 691 } 692 693 for (i = 0; i < npages; ++i) { 694 /* 695 * This looks unsafe, because we validate, then regrab 696 * the TCE from userspace which could have been changed by 697 * another thread. 698 * 699 * But it actually is safe, because the relevant checks will be 700 * re-executed in the following code. If userspace tries to 701 * change this dodgily it will result in a messier failure mode 702 * but won't threaten the host. 703 */ 704 if (get_user(tce, tces + i)) { 705 ret = H_TOO_HARD; 706 goto unlock_exit; 707 } 708 tce = be64_to_cpu(tce); 709 710 if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) 711 return H_PARAMETER; 712 713 list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { 714 ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, 715 stit->tbl, entry + i, ua, 716 iommu_tce_direction(tce)); 717 718 if (ret != H_SUCCESS) { 719 kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, 720 entry); 721 goto unlock_exit; 722 } 723 } 724 725 kvmppc_tce_put(stt, entry + i, tce); 726 } 727 728 unlock_exit: 729 srcu_read_unlock(&vcpu->kvm->srcu, idx); 730 731 return ret; 732 } 733 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect); 734 735 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu, 736 unsigned long liobn, unsigned long ioba, 737 unsigned long tce_value, unsigned long npages) 738 { 739 struct kvmppc_spapr_tce_table *stt; 740 long i, ret; 741 struct kvmppc_spapr_tce_iommu_table *stit; 742 743 stt = kvmppc_find_table(vcpu->kvm, liobn); 744 if (!stt) 745 return H_TOO_HARD; 746 747 ret = kvmppc_ioba_validate(stt, ioba, npages); 748 if (ret != H_SUCCESS) 749 return ret; 750 751 /* Check permission bits only to allow userspace poison TCE for debug */ 752 if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ)) 753 return H_PARAMETER; 754 755 list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { 756 unsigned long entry = ioba >> stt->page_shift; 757 758 for (i = 0; i < npages; ++i) { 759 ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt, 760 stit->tbl, entry + i); 761 762 if (ret == H_SUCCESS) 763 continue; 764 765 if (ret == H_TOO_HARD) 766 return ret; 767 768 WARN_ON_ONCE(1); 769 kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry); 770 } 771 } 772 773 for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift)) 774 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value); 775 776 return H_SUCCESS; 777 } 778 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce); 779