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/tlbflush.h>
  35 #include <asm/kvm_ppc.h>
  36 #include <asm/kvm_book3s.h>
  37 #include <asm/book3s/64/mmu-hash.h>
  38 #include <asm/hvcall.h>
  39 #include <asm/synch.h>
  40 #include <asm/ppc-opcode.h>
  41 #include <asm/kvm_host.h>
  42 #include <asm/udbg.h>
  43 #include <asm/iommu.h>
  44 #include <asm/tce.h>
  45 #include <asm/mmu_context.h>
  46
  47 static unsigned long kvmppc_tce_pages(unsigned long iommu_pages)
  48 {
  49         return ALIGN(iommu_pages * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
  50 }
  51
  52 static unsigned long kvmppc_stt_pages(unsigned long tce_pages)
  53 {
  54         unsigned long stt_bytes = sizeof(struct kvmppc_spapr_tce_table) +
  55                         (tce_pages * sizeof(struct page *));
  56
  57         return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE;
  58 }
  59
  60 static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc)
  61 {
  62         long ret = 0;
  63
  64         if (!current || !current->mm)
  65                 return ret; /* process exited */
  66
  67         down_write(&current->mm->mmap_sem);
  68
  69         if (inc) {
  70                 unsigned long locked, lock_limit;
  71
  72                 locked = current->mm->locked_vm + stt_pages;
  73                 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  74                 if (locked > lock_limit && !capable(CAP_IPC_LOCK))
  75                         ret = -ENOMEM;
  76                 else
  77                         current->mm->locked_vm += stt_pages;
  78         } else {
  79                 if (WARN_ON_ONCE(stt_pages > current->mm->locked_vm))
  80                         stt_pages = current->mm->locked_vm;
  81
  82                 current->mm->locked_vm -= stt_pages;
  83         }
  84
  85         pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid,
  86                         inc ? '+' : '-',
  87                         stt_pages << PAGE_SHIFT,
  88                         current->mm->locked_vm << PAGE_SHIFT,
  89                         rlimit(RLIMIT_MEMLOCK),
  90                         ret ? " - exceeded" : "");
  91
  92         up_write(&current->mm->mmap_sem);
  93
  94         return ret;
  95 }
  96
  97 static void kvm_spapr_tce_iommu_table_free(struct rcu_head *head)
  98 {
  99         struct kvmppc_spapr_tce_iommu_table *stit = container_of(head,
 100                         struct kvmppc_spapr_tce_iommu_table, rcu);
 101
 102         iommu_tce_table_put(stit->tbl);
 103
 104         kfree(stit);
 105 }
 106
 107 static void kvm_spapr_tce_liobn_put(struct kref *kref)
 108 {
 109         struct kvmppc_spapr_tce_iommu_table *stit = container_of(kref,
 110                         struct kvmppc_spapr_tce_iommu_table, kref);
 111
 112         list_del_rcu(&stit->next);
 113
 114         call_rcu(&stit->rcu, kvm_spapr_tce_iommu_table_free);
 115 }
 116
 117 extern void kvm_spapr_tce_release_iommu_group(struct kvm *kvm,
 118                 struct iommu_group *grp)
 119 {
 120         int i;
 121         struct kvmppc_spapr_tce_table *stt;
 122         struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
 123         struct iommu_table_group *table_group = NULL;
 124
 125         list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
 126
 127                 table_group = iommu_group_get_iommudata(grp);
 128                 if (WARN_ON(!table_group))
 129                         continue;
 130
 131                 list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) {
 132                         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 133                                 if (table_group->tables[i] != stit->tbl)
 134                                         continue;
 135
 136                                 kref_put(&stit->kref, kvm_spapr_tce_liobn_put);
 137                                 return;
 138                         }
 139                 }
 140         }
 141 }
 142
 143 extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
 144                 struct iommu_group *grp)
 145 {
 146         struct kvmppc_spapr_tce_table *stt = NULL;
 147         bool found = false;
 148         struct iommu_table *tbl = NULL;
 149         struct iommu_table_group *table_group;
 150         long i;
 151         struct kvmppc_spapr_tce_iommu_table *stit;
 152         struct fd f;
 153
 154         f = fdget(tablefd);
 155         if (!f.file)
 156                 return -EBADF;
 157
 158         list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
 159                 if (stt == f.file->private_data) {
 160                         found = true;
 161                         break;
 162                 }
 163         }
 164
 165         fdput(f);
 166
 167         if (!found)
 168                 return -EINVAL;
 169
 170         table_group = iommu_group_get_iommudata(grp);
 171         if (WARN_ON(!table_group))
 172                 return -EFAULT;
 173
 174         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 175                 struct iommu_table *tbltmp = table_group->tables[i];
 176
 177                 if (!tbltmp)
 178                         continue;
 179                 /*
 180                  * Make sure hardware table parameters are exactly the same;
 181                  * this is used in the TCE handlers where boundary checks
 182                  * use only the first attached table.
 183                  */
 184                 if ((tbltmp->it_page_shift == stt->page_shift) &&
 185                                 (tbltmp->it_offset == stt->offset) &&
 186                                 (tbltmp->it_size == stt->size)) {
 187                         /*
 188                          * Reference the table to avoid races with
 189                          * add/remove DMA windows.
 190                          */
 191                         tbl = iommu_tce_table_get(tbltmp);
 192                         break;
 193                 }
 194         }
 195         if (!tbl)
 196                 return -EINVAL;
 197
 198         list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
 199                 if (tbl != stit->tbl)
 200                         continue;
 201
 202                 if (!kref_get_unless_zero(&stit->kref)) {
 203                         /* stit is being destroyed */
 204                         iommu_tce_table_put(tbl);
 205                         return -ENOTTY;
 206                 }
 207                 /*
 208                  * The table is already known to this KVM, we just increased
 209                  * its KVM reference counter and can return.
 210                  */
 211                 return 0;
 212         }
 213
 214         stit = kzalloc(sizeof(*stit), GFP_KERNEL);
 215         if (!stit) {
 216                 iommu_tce_table_put(tbl);
 217                 return -ENOMEM;
 218         }
 219
 220         stit->tbl = tbl;
 221         kref_init(&stit->kref);
 222
 223         list_add_rcu(&stit->next, &stt->iommu_tables);
 224
 225         return 0;
 226 }
 227
 228 static void release_spapr_tce_table(struct rcu_head *head)
 229 {
 230         struct kvmppc_spapr_tce_table *stt = container_of(head,
 231                         struct kvmppc_spapr_tce_table, rcu);
 232         unsigned long i, npages = kvmppc_tce_pages(stt->size);
 233
 234         for (i = 0; i < npages; i++)
 235                 __free_page(stt->pages[i]);
 236
 237         kfree(stt);
 238 }
 239
 240 static int kvm_spapr_tce_fault(struct vm_fault *vmf)
 241 {
 242         struct kvmppc_spapr_tce_table *stt = vmf->vma->vm_file->private_data;
 243         struct page *page;
 244
 245         if (vmf->pgoff >= kvmppc_tce_pages(stt->size))
 246                 return VM_FAULT_SIGBUS;
 247
 248         page = stt->pages[vmf->pgoff];
 249         get_page(page);
 250         vmf->page = page;
 251         return 0;
 252 }
 253
 254 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
 255         .fault = kvm_spapr_tce_fault,
 256 };
 257
 258 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
 259 {
 260         vma->vm_ops = &kvm_spapr_tce_vm_ops;
 261         return 0;
 262 }
 263
 264 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
 265 {
 266         struct kvmppc_spapr_tce_table *stt = filp->private_data;
 267         struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
 268
 269         list_del_rcu(&stt->list);
 270
 271         list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) {
 272                 WARN_ON(!kref_read(&stit->kref));
 273                 while (1) {
 274                         if (kref_put(&stit->kref, kvm_spapr_tce_liobn_put))
 275                                 break;
 276                 }
 277         }
 278
 279         kvm_put_kvm(stt->kvm);
 280
 281         kvmppc_account_memlimit(
 282                 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false);
 283         call_rcu(&stt->rcu, release_spapr_tce_table);
 284
 285         return 0;
 286 }
 287
 288 static const struct file_operations kvm_spapr_tce_fops = {
 289         .mmap           = kvm_spapr_tce_mmap,
 290         .release        = kvm_spapr_tce_release,
 291 };
 292
 293 long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 294                                    struct kvm_create_spapr_tce_64 *args)
 295 {
 296         struct kvmppc_spapr_tce_table *stt = NULL;
 297         unsigned long npages, size;
 298         int ret = -ENOMEM;
 299         int i;
 300
 301         if (!args->size)
 302                 return -EINVAL;
 303
 304         /* Check this LIOBN hasn't been previously allocated */
 305         list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
 306                 if (stt->liobn == args->liobn)
 307                         return -EBUSY;
 308         }
 309
 310         size = _ALIGN_UP(args->size, PAGE_SIZE >> 3);
 311         npages = kvmppc_tce_pages(size);
 312         ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
 313         if (ret) {
 314                 stt = NULL;
 315                 goto fail;
 316         }
 317
 318         ret = -ENOMEM;
 319         stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 320                       GFP_KERNEL);
 321         if (!stt)
 322                 goto fail;
 323
 324         stt->liobn = args->liobn;
 325         stt->page_shift = args->page_shift;
 326         stt->offset = args->offset;
 327         stt->size = size;
 328         stt->kvm = kvm;
 329         INIT_LIST_HEAD_RCU(&stt->iommu_tables);
 330
 331         for (i = 0; i < npages; i++) {
 332                 stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
 333                 if (!stt->pages[i])
 334                         goto fail;
 335         }
 336
 337         kvm_get_kvm(kvm);
 338
 339         mutex_lock(&kvm->lock);
 340         list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
 341
 342         mutex_unlock(&kvm->lock);
 343
 344         return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 345                                 stt, O_RDWR | O_CLOEXEC);
 346
 347 fail:
 348         if (stt) {
 349                 for (i = 0; i < npages; i++)
 350                         if (stt->pages[i])
 351                                 __free_page(stt->pages[i]);
 352
 353                 kfree(stt);
 354         }
 355         return ret;
 356 }
 357
 358 static void kvmppc_clear_tce(struct iommu_table *tbl, unsigned long entry)
 359 {
 360         unsigned long hpa = 0;
 361         enum dma_data_direction dir = DMA_NONE;
 362
 363         iommu_tce_xchg(tbl, entry, &hpa, &dir);
 364 }
 365
 366 static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm,
 367                 struct iommu_table *tbl, unsigned long entry)
 368 {
 369         struct mm_iommu_table_group_mem_t *mem = NULL;
 370         const unsigned long pgsize = 1ULL << tbl->it_page_shift;
 371         unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
 372
 373         if (!pua)
 374                 /* it_userspace allocation might be delayed */
 375                 return H_TOO_HARD;
 376
 377         mem = mm_iommu_lookup(kvm->mm, *pua, pgsize);
 378         if (!mem)
 379                 return H_TOO_HARD;
 380
 381         mm_iommu_mapped_dec(mem);
 382
 383         *pua = 0;
 384
 385         return H_SUCCESS;
 386 }
 387
 388 static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
 389                 struct iommu_table *tbl, unsigned long entry)
 390 {
 391         enum dma_data_direction dir = DMA_NONE;
 392         unsigned long hpa = 0;
 393         long ret;
 394
 395         if (WARN_ON_ONCE(iommu_tce_xchg(tbl, entry, &hpa, &dir)))
 396                 return H_HARDWARE;
 397
 398         if (dir == DMA_NONE)
 399                 return H_SUCCESS;
 400
 401         ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
 402         if (ret != H_SUCCESS)
 403                 iommu_tce_xchg(tbl, entry, &hpa, &dir);
 404
 405         return ret;
 406 }
 407
 408 long kvmppc_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
 409                 unsigned long entry, unsigned long ua,
 410                 enum dma_data_direction dir)
 411 {
 412         long ret;
 413         unsigned long hpa, *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
 414         struct mm_iommu_table_group_mem_t *mem;
 415
 416         if (!pua)
 417                 /* it_userspace allocation might be delayed */
 418                 return H_TOO_HARD;
 419
 420         mem = mm_iommu_lookup(kvm->mm, ua, 1ULL << tbl->it_page_shift);
 421         if (!mem)
 422                 /* This only handles v2 IOMMU type, v1 is handled via ioctl() */
 423                 return H_TOO_HARD;
 424
 425         if (WARN_ON_ONCE(mm_iommu_ua_to_hpa(mem, ua, &hpa)))
 426                 return H_HARDWARE;
 427
 428         if (mm_iommu_mapped_inc(mem))
 429                 return H_CLOSED;
 430
 431         ret = iommu_tce_xchg(tbl, entry, &hpa, &dir);
 432         if (WARN_ON_ONCE(ret)) {
 433                 mm_iommu_mapped_dec(mem);
 434                 return H_HARDWARE;
 435         }
 436
 437         if (dir != DMA_NONE)
 438                 kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
 439
 440         *pua = ua;
 441
 442         return 0;
 443 }
 444
 445 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
 446                       unsigned long ioba, unsigned long tce)
 447 {
 448         struct kvmppc_spapr_tce_table *stt;
 449         long ret, idx;
 450         struct kvmppc_spapr_tce_iommu_table *stit;
 451         unsigned long entry, ua = 0;
 452         enum dma_data_direction dir;
 453
 454         /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
 455         /*          liobn, ioba, tce); */
 456
 457         stt = kvmppc_find_table(vcpu->kvm, liobn);
 458         if (!stt)
 459                 return H_TOO_HARD;
 460
 461         ret = kvmppc_ioba_validate(stt, ioba, 1);
 462         if (ret != H_SUCCESS)
 463                 return ret;
 464
 465         ret = kvmppc_tce_validate(stt, tce);
 466         if (ret != H_SUCCESS)
 467                 return ret;
 468
 469         dir = iommu_tce_direction(tce);
 470         if ((dir != DMA_NONE) && kvmppc_gpa_to_ua(vcpu->kvm,
 471                         tce & ~(TCE_PCI_READ | TCE_PCI_WRITE), &ua, NULL))
 472                 return H_PARAMETER;
 473
 474         entry = ioba >> stt->page_shift;
 475
 476         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 477                 if (dir == DMA_NONE) {
 478                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm,
 479                                         stit->tbl, entry);
 480                 } else {
 481                         idx = srcu_read_lock(&vcpu->kvm->srcu);
 482                         ret = kvmppc_tce_iommu_map(vcpu->kvm, stit->tbl,
 483                                         entry, ua, dir);
 484                         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 485                 }
 486
 487                 if (ret == H_SUCCESS)
 488                         continue;
 489
 490                 if (ret == H_TOO_HARD)
 491                         return ret;
 492
 493                 WARN_ON_ONCE(1);
 494                 kvmppc_clear_tce(stit->tbl, entry);
 495         }
 496
 497         kvmppc_tce_put(stt, entry, tce);
 498
 499         return H_SUCCESS;
 500 }
 501 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
 502
 503 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
 504                 unsigned long liobn, unsigned long ioba,
 505                 unsigned long tce_list, unsigned long npages)
 506 {
 507         struct kvmppc_spapr_tce_table *stt;
 508         long i, ret = H_SUCCESS, idx;
 509         unsigned long entry, ua = 0;
 510         u64 __user *tces;
 511         u64 tce;
 512         struct kvmppc_spapr_tce_iommu_table *stit;
 513
 514         stt = kvmppc_find_table(vcpu->kvm, liobn);
 515         if (!stt)
 516                 return H_TOO_HARD;
 517
 518         entry = ioba >> stt->page_shift;
 519         /*
 520          * SPAPR spec says that the maximum size of the list is 512 TCEs
 521          * so the whole table fits in 4K page
 522          */
 523         if (npages > 512)
 524                 return H_PARAMETER;
 525
 526         if (tce_list & (SZ_4K - 1))
 527                 return H_PARAMETER;
 528
 529         ret = kvmppc_ioba_validate(stt, ioba, npages);
 530         if (ret != H_SUCCESS)
 531                 return ret;
 532
 533         idx = srcu_read_lock(&vcpu->kvm->srcu);
 534         if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL)) {
 535                 ret = H_TOO_HARD;
 536                 goto unlock_exit;
 537         }
 538         tces = (u64 __user *) ua;
 539
 540         for (i = 0; i < npages; ++i) {
 541                 if (get_user(tce, tces + i)) {
 542                         ret = H_TOO_HARD;
 543                         goto unlock_exit;
 544                 }
 545                 tce = be64_to_cpu(tce);
 546
 547                 ret = kvmppc_tce_validate(stt, tce);
 548                 if (ret != H_SUCCESS)
 549                         goto unlock_exit;
 550
 551                 if (kvmppc_gpa_to_ua(vcpu->kvm,
 552                                 tce & ~(TCE_PCI_READ | TCE_PCI_WRITE),
 553                                 &ua, NULL))
 554                         return H_PARAMETER;
 555
 556                 list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 557                         ret = kvmppc_tce_iommu_map(vcpu->kvm,
 558                                         stit->tbl, entry + i, ua,
 559                                         iommu_tce_direction(tce));
 560
 561                         if (ret == H_SUCCESS)
 562                                 continue;
 563
 564                         if (ret == H_TOO_HARD)
 565                                 goto unlock_exit;
 566
 567                         WARN_ON_ONCE(1);
 568                         kvmppc_clear_tce(stit->tbl, entry);
 569                 }
 570
 571                 kvmppc_tce_put(stt, entry + i, tce);
 572         }
 573
 574 unlock_exit:
 575         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 576
 577         return ret;
 578 }
 579 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect);
 580
 581 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
 582                 unsigned long liobn, unsigned long ioba,
 583                 unsigned long tce_value, unsigned long npages)
 584 {
 585         struct kvmppc_spapr_tce_table *stt;
 586         long i, ret;
 587         struct kvmppc_spapr_tce_iommu_table *stit;
 588
 589         stt = kvmppc_find_table(vcpu->kvm, liobn);
 590         if (!stt)
 591                 return H_TOO_HARD;
 592
 593         ret = kvmppc_ioba_validate(stt, ioba, npages);
 594         if (ret != H_SUCCESS)
 595                 return ret;
 596
 597         /* Check permission bits only to allow userspace poison TCE for debug */
 598         if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
 599                 return H_PARAMETER;
 600
 601         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
 602                 unsigned long entry = ioba >> stit->tbl->it_page_shift;
 603
 604                 for (i = 0; i < npages; ++i) {
 605                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm,
 606                                         stit->tbl, entry + i);
 607
 608                         if (ret == H_SUCCESS)
 609                                 continue;
 610
 611                         if (ret == H_TOO_HARD)
 612                                 return ret;
 613
 614                         WARN_ON_ONCE(1);
 615                         kvmppc_clear_tce(stit->tbl, entry);
 616                 }
 617         }
 618
 619         for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
 620                 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
 621
 622         return H_SUCCESS;
 623 }
 624 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce);