arch/powerpc/kvm/book3s_64_vio.c

   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(&current->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(&current->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                 __free_page(stt->pages[i]);
 232
 233         kfree(stt);
 234 }
 235
 236 static vm_fault_t kvm_spapr_tce_fault(struct vm_fault *vmf)
 237 {
 238         struct kvmppc_spapr_tce_table *stt = vmf->vma->vm_file->private_data;
 239         struct page *page;
 240
 241         if (vmf->pgoff >= kvmppc_tce_pages(stt->size))
 242                 return VM_FAULT_SIGBUS;
 243
 244         page = stt->pages[vmf->pgoff];
 245         get_page(page);
 246         vmf->page = page;
 247         return 0;
 248 }
 249
 250 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
 251         .fault = kvm_spapr_tce_fault,
 252 };
 253
 254 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
 255 {
 256         vma->vm_ops = &kvm_spapr_tce_vm_ops;
 257         return 0;
 258 }
 259
 260 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
 261 {
 262         struct kvmppc_spapr_tce_table *stt = filp->private_data;
 263         struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
 264         struct kvm *kvm = stt->kvm;
 265
 266         mutex_lock(&kvm->lock);
 267         list_del_rcu(&stt->list);
 268         mutex_unlock(&kvm->lock);
 269
 270         list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) {
 271                 WARN_ON(!kref_read(&stit->kref));
 272                 while (1) {
 273                         if (kref_put(&stit->kref, kvm_spapr_tce_liobn_put))
 274                                 break;
 275                 }
 276         }
 277
 278         kvm_put_kvm(stt->kvm);
 279
 280         kvmppc_account_memlimit(
 281                 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false);
 282         call_rcu(&stt->rcu, release_spapr_tce_table);
 283
 284         return 0;
 285 }
 286
 287 static const struct file_operations kvm_spapr_tce_fops = {
 288         .mmap           = kvm_spapr_tce_mmap,
 289         .release        = kvm_spapr_tce_release,
 290 };
 291
 292 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 293                                    struct kvm_create_spapr_tce_64 *args)
 294 {
 295         struct kvmppc_spapr_tce_table *stt = NULL;
 296         struct kvmppc_spapr_tce_table *siter;
 297         unsigned long npages, size = args->size;
 298         int ret = -ENOMEM;
 299         int i;
 300
 301         if (!args->size || args->page_shift < 12 || args->page_shift > 34 ||
 302                 (args->offset + args->size > (ULLONG_MAX >> args->page_shift)))
 303                 return -EINVAL;
 304
 305         npages = kvmppc_tce_pages(size);
 306         ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
 307         if (ret)
 308                 return ret;
 309
 310         ret = -ENOMEM;
 311         stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 312                       GFP_KERNEL);
 313         if (!stt)
 314                 goto fail_acct;
 315
 316         stt->liobn = args->liobn;
 317         stt->page_shift = args->page_shift;
 318         stt->offset = args->offset;
 319         stt->size = size;
 320         stt->kvm = kvm;
 321         INIT_LIST_HEAD_RCU(&stt->iommu_tables);
 322
 323         for (i = 0; i < npages; i++) {
 324                 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
 325                 if (!stt->pages[i])
 326                         goto fail;
 327         }
 328
 329         mutex_lock(&kvm->lock);
 330
 331         /* Check this LIOBN hasn't been previously allocated */
 332         ret = 0;
 333         list_for_each_entry(siter, &kvm->arch.spapr_tce_tables, list) {
 334                 if (siter->liobn == args->liobn) {
 335                         ret = -EBUSY;
 336                         break;
 337                 }
 338         }
 339
 340         kvm_get_kvm(kvm);
 341         if (!ret)
 342                 ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 343                                        stt, O_RDWR | O_CLOEXEC);
 344
 345         if (ret >= 0)
 346                 list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
 347         else
 348                 kvm_put_kvm(kvm);
 349
 350         mutex_unlock(&kvm->lock);
 351
 352         if (ret >= 0)
 353                 return ret;
 354
 355  fail:
 356         for (i = 0; i < npages; i++)
 357                 if (stt->pages[i])
 358                         __free_page(stt->pages[i]);
 359
 360         kfree(stt);
 361  fail_acct:
 362         kvmppc_account_memlimit(kvmppc_stt_pages(npages), false);
 363         return ret;
 364 }
 365
 366 static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt,
 367                 unsigned long tce)
 368 {
 369         unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
 370         enum dma_data_direction dir = iommu_tce_direction(tce);
 371         struct kvmppc_spapr_tce_iommu_table *stit;
 372         unsigned long ua = 0;
 373
 374         /* Allow userspace to poison TCE table */
 375         if (dir == DMA_NONE)
 376                 return H_SUCCESS;
 377
 378         if (iommu_tce_check_gpa(stt->page_shift, gpa))
 379                 return H_TOO_HARD;
 380
 381         if (kvmppc_tce_to_ua(stt->kvm, tce, &ua, NULL))
 382                 return H_TOO_HARD;
 383
 384         list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
 385                 unsigned long hpa = 0;
 386                 struct mm_iommu_table_group_mem_t *mem;
 387                 long shift = stit->tbl->it_page_shift;
 388
 389                 mem = mm_iommu_lookup(stt->kvm->mm, ua, 1ULL << shift);
 390                 if (!mem)
 391                         return H_TOO_HARD;
 392
 393                 if (mm_iommu_ua_to_hpa(mem, ua, shift, &hpa))
 394                         return H_TOO_HARD;
 395         }
 396
 397         return H_SUCCESS;
 398 }
 399
 400 static void kvmppc_clear_tce(struct mm_struct *mm, struct iommu_table *tbl,
 401                 unsigned long entry)
 402 {
 403         unsigned long hpa = 0;
 404         enum dma_data_direction dir = DMA_NONE;
 405
 406         iommu_tce_xchg(mm, tbl, entry, &hpa, &dir);
 407 }
 408
 409 static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm,
 410                 struct iommu_table *tbl, unsigned long entry)
 411 {
 412         struct mm_iommu_table_group_mem_t *mem = NULL;
 413         const unsigned long pgsize = 1ULL << tbl->it_page_shift;
 414         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
 415
 416         if (!pua)
 417                 return H_SUCCESS;
 418
 419         mem = mm_iommu_lookup(kvm->mm, be64_to_cpu(*pua), pgsize);
 420         if (!mem)
 421                 return H_TOO_HARD;
 422
 423         mm_iommu_mapped_dec(mem);
 424
 425         *pua = cpu_to_be64(0);
 426
 427         return H_SUCCESS;
 428 }
 429
 430 static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm,
 431                 struct iommu_table *tbl, unsigned long entry)
 432 {
 433         enum dma_data_direction dir = DMA_NONE;
 434         unsigned long hpa = 0;
 435         long ret;
 436
 437         if (WARN_ON_ONCE(iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir)))
 438                 return H_TOO_HARD;
 439
 440         if (dir == DMA_NONE)
 441                 return H_SUCCESS;
 442
 443         ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
 444         if (ret != H_SUCCESS)
 445                 iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir);
 446
 447         return ret;
 448 }
 449
 450 static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
 451                 struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
 452                 unsigned long entry)
 453 {
 454         unsigned long i, ret = H_SUCCESS;
 455         unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
 456         unsigned long io_entry = entry * subpages;
 457
 458         for (i = 0; i < subpages; ++i) {
 459                 ret = kvmppc_tce_iommu_do_unmap(kvm, tbl, io_entry + i);
 460                 if (ret != H_SUCCESS)
 461                         break;
 462         }
 463
 464         return ret;
 465 }
 466
 467 long kvmppc_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl,
 468                 unsigned long entry, unsigned long ua,
 469                 enum dma_data_direction dir)
 470 {
 471         long ret;
 472         unsigned long hpa;
 473         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
 474         struct mm_iommu_table_group_mem_t *mem;
 475
 476         if (!pua)
 477                 /* it_userspace allocation might be delayed */
 478                 return H_TOO_HARD;
 479
 480         mem = mm_iommu_lookup(kvm->mm, ua, 1ULL << tbl->it_page_shift);
 481         if (!mem)
 482                 /* This only handles v2 IOMMU type, v1 is handled via ioctl() */
 483                 return H_TOO_HARD;
 484
 485         if (WARN_ON_ONCE(mm_iommu_ua_to_hpa(mem, ua, tbl->it_page_shift, &hpa)))
 486                 return H_TOO_HARD;
 487
 488         if (mm_iommu_mapped_inc(mem))
 489                 return H_TOO_HARD;
 490
 491         ret = iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir);
 492         if (WARN_ON_ONCE(ret)) {
 493                 mm_iommu_mapped_dec(mem);
 494                 return H_TOO_HARD;
 495         }
 496
 497         if (dir != DMA_NONE)
 498                 kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
 499
 500         *pua = cpu_to_be64(ua);
 501
 502         return 0;
 503 }
 504
 505 static long kvmppc_tce_iommu_map(struct kvm *kvm,
 506                 struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
 507                 unsigned long entry, unsigned long ua,
 508                 enum dma_data_direction dir)
 509 {
 510         unsigned long i, pgoff, ret = H_SUCCESS;
 511         unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
 512         unsigned long io_entry = entry * subpages;
 513
 514         for (i = 0, pgoff = 0; i < subpages;
 515                         ++i, pgoff += IOMMU_PAGE_SIZE(tbl)) {
 516
 517                 ret = kvmppc_tce_iommu_do_map(kvm, tbl,
 518                                 io_entry + i, ua + pgoff, dir);
 519                 if (ret != H_SUCCESS)
 520                         break;
 521         }
 522
 523         return ret;
 524 }
 525
 526 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
 527                       unsigned long ioba, unsigned long tce)
 528 {
 529         struct kvmppc_spapr_tce_table *stt;
 530         long ret, idx;
 531         struct kvmppc_spapr_tce_iommu_table *stit;
 532         unsigned long entry, ua = 0;
 533         enum dma_data_direction dir;
 534
 535         /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
 536         /*          liobn, ioba, tce); */
 537
 538         stt = kvmppc_find_table(vcpu->kvm, liobn);
 539         if (!stt)
 540                 return H_TOO_HARD;
 541
 542         ret = kvmppc_ioba_validate(stt, ioba, 1);
 543         if (ret != H_SUCCESS)
 544                 return ret;
 545
 546         idx = srcu_read_lock(&vcpu->kvm->srcu);
 547
 548         ret = kvmppc_tce_validate(stt, tce);
 549         if (ret != H_SUCCESS)
 550                 goto unlock_exit;
 551
 552         dir = iommu_tce_direction(tce);
 553
 554         if ((dir != DMA_NONE) && kvmppc_tce_to_ua(vcpu->kvm, tce, &ua, NULL)) {
 555                 ret = H_PARAMETER;
 556                 goto unlock_exit;
 557         }
 558
 559         entry = ioba >> stt->page_shift;
 560
 561         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 562                 if (dir == DMA_NONE)
 563                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt,
 564                                         stit->tbl, entry);
 565                 else
 566                         ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, stit->tbl,
 567                                         entry, ua, dir);
 568
 569                 if (ret != H_SUCCESS) {
 570                         kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry);
 571                         goto unlock_exit;
 572                 }
 573         }
 574
 575         kvmppc_tce_put(stt, entry, tce);
 576
 577 unlock_exit:
 578         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 579
 580         return ret;
 581 }
 582 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
 583
 584 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
 585                 unsigned long liobn, unsigned long ioba,
 586                 unsigned long tce_list, unsigned long npages)
 587 {
 588         struct kvmppc_spapr_tce_table *stt;
 589         long i, ret = H_SUCCESS, idx;
 590         unsigned long entry, ua = 0;
 591         u64 __user *tces;
 592         u64 tce;
 593         struct kvmppc_spapr_tce_iommu_table *stit;
 594
 595         stt = kvmppc_find_table(vcpu->kvm, liobn);
 596         if (!stt)
 597                 return H_TOO_HARD;
 598
 599         entry = ioba >> stt->page_shift;
 600         /*
 601          * SPAPR spec says that the maximum size of the list is 512 TCEs
 602          * so the whole table fits in 4K page
 603          */
 604         if (npages > 512)
 605                 return H_PARAMETER;
 606
 607         if (tce_list & (SZ_4K - 1))
 608                 return H_PARAMETER;
 609
 610         ret = kvmppc_ioba_validate(stt, ioba, npages);
 611         if (ret != H_SUCCESS)
 612                 return ret;
 613
 614         idx = srcu_read_lock(&vcpu->kvm->srcu);
 615         if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua, NULL)) {
 616                 ret = H_TOO_HARD;
 617                 goto unlock_exit;
 618         }
 619         tces = (u64 __user *) ua;
 620
 621         for (i = 0; i < npages; ++i) {
 622                 if (get_user(tce, tces + i)) {
 623                         ret = H_TOO_HARD;
 624                         goto unlock_exit;
 625                 }
 626                 tce = be64_to_cpu(tce);
 627
 628                 ret = kvmppc_tce_validate(stt, tce);
 629                 if (ret != H_SUCCESS)
 630                         goto unlock_exit;
 631         }
 632
 633         for (i = 0; i < npages; ++i) {
 634                 /*
 635                  * This looks unsafe, because we validate, then regrab
 636                  * the TCE from userspace which could have been changed by
 637                  * another thread.
 638                  *
 639                  * But it actually is safe, because the relevant checks will be
 640                  * re-executed in the following code.  If userspace tries to
 641                  * change this dodgily it will result in a messier failure mode
 642                  * but won't threaten the host.
 643                  */
 644                 if (get_user(tce, tces + i)) {
 645                         ret = H_TOO_HARD;
 646                         goto unlock_exit;
 647                 }
 648                 tce = be64_to_cpu(tce);
 649
 650                 if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua, NULL))
 651                         return H_PARAMETER;
 652
 653                 list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 654                         ret = kvmppc_tce_iommu_map(vcpu->kvm, stt,
 655                                         stit->tbl, entry + i, ua,
 656                                         iommu_tce_direction(tce));
 657
 658                         if (ret != H_SUCCESS) {
 659                                 kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl,
 660                                                 entry);
 661                                 goto unlock_exit;
 662                         }
 663                 }
 664
 665                 kvmppc_tce_put(stt, entry + i, tce);
 666         }
 667
 668 unlock_exit:
 669         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 670
 671         return ret;
 672 }
 673 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect);
 674
 675 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
 676                 unsigned long liobn, unsigned long ioba,
 677                 unsigned long tce_value, unsigned long npages)
 678 {
 679         struct kvmppc_spapr_tce_table *stt;
 680         long i, ret;
 681         struct kvmppc_spapr_tce_iommu_table *stit;
 682
 683         stt = kvmppc_find_table(vcpu->kvm, liobn);
 684         if (!stt)
 685                 return H_TOO_HARD;
 686
 687         ret = kvmppc_ioba_validate(stt, ioba, npages);
 688         if (ret != H_SUCCESS)
 689                 return ret;
 690
 691         /* Check permission bits only to allow userspace poison TCE for debug */
 692         if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
 693                 return H_PARAMETER;
 694
 695         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 696                 unsigned long entry = ioba >> stt->page_shift;
 697
 698                 for (i = 0; i < npages; ++i) {
 699                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt,
 700                                         stit->tbl, entry + i);
 701
 702                         if (ret == H_SUCCESS)
 703                                 continue;
 704
 705                         if (ret == H_TOO_HARD)
 706                                 return ret;
 707
 708                         WARN_ON_ONCE(1);
 709                         kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry);
 710                 }
 711         }
 712
 713         for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
 714                 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
 715
 716         return H_SUCCESS;
 717 }
 718 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce);