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/hugetlb.h>
  28 #include <linux/list.h>
  29 #include <linux/anon_inodes.h>
  30 #include <linux/iommu.h>
  31 #include <linux/file.h>
  32
  33 #include <asm/tlbflush.h>
  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                                 return;
 137                         }
 138                 }
 139         }
 140 }
 141
 142 extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
 143                 struct iommu_group *grp)
 144 {
 145         struct kvmppc_spapr_tce_table *stt = NULL;
 146         bool found = false;
 147         struct iommu_table *tbl = NULL;
 148         struct iommu_table_group *table_group;
 149         long i;
 150         struct kvmppc_spapr_tce_iommu_table *stit;
 151         struct fd f;
 152
 153         f = fdget(tablefd);
 154         if (!f.file)
 155                 return -EBADF;
 156
 157         list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
 158                 if (stt == f.file->private_data) {
 159                         found = true;
 160                         break;
 161                 }
 162         }
 163
 164         fdput(f);
 165
 166         if (!found)
 167                 return -EINVAL;
 168
 169         table_group = iommu_group_get_iommudata(grp);
 170         if (WARN_ON(!table_group))
 171                 return -EFAULT;
 172
 173         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 174                 struct iommu_table *tbltmp = table_group->tables[i];
 175
 176                 if (!tbltmp)
 177                         continue;
 178                 /*
 179                  * Make sure hardware table parameters are exactly the same;
 180                  * this is used in the TCE handlers where boundary checks
 181                  * use only the first attached table.
 182                  */
 183                 if ((tbltmp->it_page_shift == stt->page_shift) &&
 184                                 (tbltmp->it_offset == stt->offset) &&
 185                                 (tbltmp->it_size == stt->size)) {
 186                         /*
 187                          * Reference the table to avoid races with
 188                          * add/remove DMA windows.
 189                          */
 190                         tbl = iommu_tce_table_get(tbltmp);
 191                         break;
 192                 }
 193         }
 194         if (!tbl)
 195                 return -EINVAL;
 196
 197         list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
 198                 if (tbl != stit->tbl)
 199                         continue;
 200
 201                 if (!kref_get_unless_zero(&stit->kref)) {
 202                         /* stit is being destroyed */
 203                         iommu_tce_table_put(tbl);
 204                         return -ENOTTY;
 205                 }
 206                 /*
 207                  * The table is already known to this KVM, we just increased
 208                  * its KVM reference counter and can return.
 209                  */
 210                 return 0;
 211         }
 212
 213         stit = kzalloc(sizeof(*stit), GFP_KERNEL);
 214         if (!stit) {
 215                 iommu_tce_table_put(tbl);
 216                 return -ENOMEM;
 217         }
 218
 219         stit->tbl = tbl;
 220         kref_init(&stit->kref);
 221
 222         list_add_rcu(&stit->next, &stt->iommu_tables);
 223
 224         return 0;
 225 }
 226
 227 static void release_spapr_tce_table(struct rcu_head *head)
 228 {
 229         struct kvmppc_spapr_tce_table *stt = container_of(head,
 230                         struct kvmppc_spapr_tce_table, rcu);
 231         unsigned long i, npages = kvmppc_tce_pages(stt->size);
 232
 233         for (i = 0; i < npages; i++)
 234                 __free_page(stt->pages[i]);
 235
 236         kfree(stt);
 237 }
 238
 239 static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 240 {
 241         struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
 242         struct page *page;
 243
 244         if (vmf->pgoff >= kvmppc_tce_pages(stt->size))
 245                 return VM_FAULT_SIGBUS;
 246
 247         page = stt->pages[vmf->pgoff];
 248         get_page(page);
 249         vmf->page = page;
 250         return 0;
 251 }
 252
 253 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
 254         .fault = kvm_spapr_tce_fault,
 255 };
 256
 257 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
 258 {
 259         vma->vm_ops = &kvm_spapr_tce_vm_ops;
 260         return 0;
 261 }
 262
 263 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
 264 {
 265         struct kvmppc_spapr_tce_table *stt = filp->private_data;
 266         struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
 267
 268         list_del_rcu(&stt->list);
 269
 270         list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) {
 271                 while (1) {
 272                         if (kref_put(&stit->kref, kvm_spapr_tce_liobn_put))
 273                                 break;
 274                 }
 275         }
 276
 277         kvm_put_kvm(stt->kvm);
 278
 279         kvmppc_account_memlimit(
 280                 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false);
 281         call_rcu(&stt->rcu, release_spapr_tce_table);
 282
 283         return 0;
 284 }
 285
 286 static const struct file_operations kvm_spapr_tce_fops = {
 287         .mmap           = kvm_spapr_tce_mmap,
 288         .release        = kvm_spapr_tce_release,
 289 };
 290
 291 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 292                                    struct kvm_create_spapr_tce_64 *args)
 293 {
 294         struct kvmppc_spapr_tce_table *stt = NULL;
 295         unsigned long npages, size;
 296         int ret = -ENOMEM;
 297         int i;
 298
 299         if (!args->size)
 300                 return -EINVAL;
 301
 302         /* Check this LIOBN hasn't been previously allocated */
 303         list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
 304                 if (stt->liobn == args->liobn)
 305                         return -EBUSY;
 306         }
 307
 308         size = args->size;
 309         npages = kvmppc_tce_pages(size);
 310         ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
 311         if (ret) {
 312                 stt = NULL;
 313                 goto fail;
 314         }
 315
 316         ret = -ENOMEM;
 317         stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 318                       GFP_KERNEL);
 319         if (!stt)
 320                 goto fail;
 321
 322         stt->liobn = args->liobn;
 323         stt->page_shift = args->page_shift;
 324         stt->offset = args->offset;
 325         stt->size = size;
 326         stt->kvm = kvm;
 327         INIT_LIST_HEAD_RCU(&stt->iommu_tables);
 328
 329         for (i = 0; i < npages; i++) {
 330                 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
 331                 if (!stt->pages[i])
 332                         goto fail;
 333         }
 334
 335         kvm_get_kvm(kvm);
 336
 337         mutex_lock(&kvm->lock);
 338         list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
 339
 340         mutex_unlock(&kvm->lock);
 341
 342         return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 343                                 stt, O_RDWR | O_CLOEXEC);
 344
 345 fail:
 346         if (stt) {
 347                 for (i = 0; i < npages; i++)
 348                         if (stt->pages[i])
 349                                 __free_page(stt->pages[i]);
 350
 351                 kfree(stt);
 352         }
 353         return ret;
 354 }
 355
 356 static void kvmppc_clear_tce(struct iommu_table *tbl, unsigned long entry)
 357 {
 358         unsigned long hpa = 0;
 359         enum dma_data_direction dir = DMA_NONE;
 360
 361         iommu_tce_xchg(tbl, entry, &hpa, &dir);
 362 }
 363
 364 static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm,
 365                 struct iommu_table *tbl, unsigned long entry)
 366 {
 367         struct mm_iommu_table_group_mem_t *mem = NULL;
 368         const unsigned long pgsize = 1ULL << tbl->it_page_shift;
 369         unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
 370
 371         if (!pua)
 372                 /* it_userspace allocation might be delayed */
 373                 return H_TOO_HARD;
 374
 375         mem = mm_iommu_lookup(kvm->mm, *pua, pgsize);
 376         if (!mem)
 377                 return H_TOO_HARD;
 378
 379         mm_iommu_mapped_dec(mem);
 380
 381         *pua = 0;
 382
 383         return H_SUCCESS;
 384 }
 385
 386 static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
 387                 struct iommu_table *tbl, unsigned long entry)
 388 {
 389         enum dma_data_direction dir = DMA_NONE;
 390         unsigned long hpa = 0;
 391         long ret;
 392
 393         if (WARN_ON_ONCE(iommu_tce_xchg(tbl, entry, &hpa, &dir)))
 394                 return H_HARDWARE;
 395
 396         if (dir == DMA_NONE)
 397                 return H_SUCCESS;
 398
 399         ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
 400         if (ret != H_SUCCESS)
 401                 iommu_tce_xchg(tbl, entry, &hpa, &dir);
 402
 403         return ret;
 404 }
 405
 406 long kvmppc_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
 407                 unsigned long entry, unsigned long ua,
 408                 enum dma_data_direction dir)
 409 {
 410         long ret;
 411         unsigned long hpa, *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
 412         struct mm_iommu_table_group_mem_t *mem;
 413
 414         if (!pua)
 415                 /* it_userspace allocation might be delayed */
 416                 return H_TOO_HARD;
 417
 418         mem = mm_iommu_lookup(kvm->mm, ua, 1ULL << tbl->it_page_shift);
 419         if (!mem)
 420                 /* This only handles v2 IOMMU type, v1 is handled via ioctl() */
 421                 return H_TOO_HARD;
 422
 423         if (WARN_ON_ONCE(mm_iommu_ua_to_hpa(mem, ua, &hpa)))
 424                 return H_HARDWARE;
 425
 426         if (mm_iommu_mapped_inc(mem))
 427                 return H_CLOSED;
 428
 429         ret = iommu_tce_xchg(tbl, entry, &hpa, &dir);
 430         if (WARN_ON_ONCE(ret)) {
 431                 mm_iommu_mapped_dec(mem);
 432                 return H_HARDWARE;
 433         }
 434
 435         if (dir != DMA_NONE)
 436                 kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
 437
 438         *pua = ua;
 439
 440         return 0;
 441 }
 442
 443 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
 444                       unsigned long ioba, unsigned long tce)
 445 {
 446         struct kvmppc_spapr_tce_table *stt;
 447         long ret, idx;
 448         struct kvmppc_spapr_tce_iommu_table *stit;
 449         unsigned long entry, ua = 0;
 450         enum dma_data_direction dir;
 451
 452         /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
 453         /*          liobn, ioba, tce); */
 454
 455         stt = kvmppc_find_table(vcpu->kvm, liobn);
 456         if (!stt)
 457                 return H_TOO_HARD;
 458
 459         ret = kvmppc_ioba_validate(stt, ioba, 1);
 460         if (ret != H_SUCCESS)
 461                 return ret;
 462
 463         ret = kvmppc_tce_validate(stt, tce);
 464         if (ret != H_SUCCESS)
 465                 return ret;
 466
 467         dir = iommu_tce_direction(tce);
 468         if ((dir != DMA_NONE) && kvmppc_gpa_to_ua(vcpu->kvm,
 469                         tce & ~(TCE_PCI_READ | TCE_PCI_WRITE), &ua, NULL))
 470                 return H_PARAMETER;
 471
 472         entry = ioba >> stt->page_shift;
 473
 474         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 475                 if (dir == DMA_NONE) {
 476                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm,
 477                                         stit->tbl, entry);
 478                 } else {
 479                         idx = srcu_read_lock(&vcpu->kvm->srcu);
 480                         ret = kvmppc_tce_iommu_map(vcpu->kvm, stit->tbl,
 481                                         entry, ua, dir);
 482                         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 483                 }
 484
 485                 if (ret == H_SUCCESS)
 486                         continue;
 487
 488                 if (ret == H_TOO_HARD)
 489                         return ret;
 490
 491                 WARN_ON_ONCE(1);
 492                 kvmppc_clear_tce(stit->tbl, entry);
 493         }
 494
 495         kvmppc_tce_put(stt, entry, tce);
 496
 497         return H_SUCCESS;
 498 }
 499 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
 500
 501 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
 502                 unsigned long liobn, unsigned long ioba,
 503                 unsigned long tce_list, unsigned long npages)
 504 {
 505         struct kvmppc_spapr_tce_table *stt;
 506         long i, ret = H_SUCCESS, idx;
 507         unsigned long entry, ua = 0;
 508         u64 __user *tces;
 509         u64 tce;
 510         struct kvmppc_spapr_tce_iommu_table *stit;
 511
 512         stt = kvmppc_find_table(vcpu->kvm, liobn);
 513         if (!stt)
 514                 return H_TOO_HARD;
 515
 516         entry = ioba >> stt->page_shift;
 517         /*
 518          * SPAPR spec says that the maximum size of the list is 512 TCEs
 519          * so the whole table fits in 4K page
 520          */
 521         if (npages > 512)
 522                 return H_PARAMETER;
 523
 524         if (tce_list & (SZ_4K - 1))
 525                 return H_PARAMETER;
 526
 527         ret = kvmppc_ioba_validate(stt, ioba, npages);
 528         if (ret != H_SUCCESS)
 529                 return ret;
 530
 531         idx = srcu_read_lock(&vcpu->kvm->srcu);
 532         if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL)) {
 533                 ret = H_TOO_HARD;
 534                 goto unlock_exit;
 535         }
 536         tces = (u64 __user *) ua;
 537
 538         for (i = 0; i < npages; ++i) {
 539                 if (get_user(tce, tces + i)) {
 540                         ret = H_TOO_HARD;
 541                         goto unlock_exit;
 542                 }
 543                 tce = be64_to_cpu(tce);
 544
 545                 ret = kvmppc_tce_validate(stt, tce);
 546                 if (ret != H_SUCCESS)
 547                         goto unlock_exit;
 548
 549                 if (kvmppc_gpa_to_ua(vcpu->kvm,
 550                                 tce & ~(TCE_PCI_READ | TCE_PCI_WRITE),
 551                                 &ua, NULL))
 552                         return H_PARAMETER;
 553
 554                 list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 555                         ret = kvmppc_tce_iommu_map(vcpu->kvm,
 556                                         stit->tbl, entry + i, ua,
 557                                         iommu_tce_direction(tce));
 558
 559                         if (ret == H_SUCCESS)
 560                                 continue;
 561
 562                         if (ret == H_TOO_HARD)
 563                                 goto unlock_exit;
 564
 565                         WARN_ON_ONCE(1);
 566                         kvmppc_clear_tce(stit->tbl, entry);
 567                 }
 568
 569                 kvmppc_tce_put(stt, entry + i, tce);
 570         }
 571
 572 unlock_exit:
 573         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 574
 575         return ret;
 576 }
 577 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect);
 578
 579 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
 580                 unsigned long liobn, unsigned long ioba,
 581                 unsigned long tce_value, unsigned long npages)
 582 {
 583         struct kvmppc_spapr_tce_table *stt;
 584         long i, ret;
 585         struct kvmppc_spapr_tce_iommu_table *stit;
 586
 587         stt = kvmppc_find_table(vcpu->kvm, liobn);
 588         if (!stt)
 589                 return H_TOO_HARD;
 590
 591         ret = kvmppc_ioba_validate(stt, ioba, npages);
 592         if (ret != H_SUCCESS)
 593                 return ret;
 594
 595         /* Check permission bits only to allow userspace poison TCE for debug */
 596         if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
 597                 return H_PARAMETER;
 598
 599         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 600                 unsigned long entry = ioba >> stit->tbl->it_page_shift;
 601
 602                 for (i = 0; i < npages; ++i) {
 603                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm,
 604                                         stit->tbl, entry + i);
 605
 606                         if (ret == H_SUCCESS)
 607                                 continue;
 608
 609                         if (ret == H_TOO_HARD)
 610                                 return ret;
 611
 612                         WARN_ON_ONCE(1);
 613                         kvmppc_clear_tce(stit->tbl, entry);
 614                 }
 615         }
 616
 617         for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
 618                 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
 619
 620         return H_SUCCESS;
 621 }
 622 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce);