drivers/s390/cio/vfio_ccw_ops.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Physical device callbacks for vfio_ccw
   4  *
   5  * Copyright IBM Corp. 2017
   6  * Copyright Red Hat, Inc. 2019
   7  *
   8  * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
   9  *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
  10  *            Cornelia Huck <cohuck@redhat.com>
  11  */
  12
  13 #include <linux/vfio.h>
  14 #include <linux/mdev.h>
  15 #include <linux/nospec.h>
  16 #include <linux/slab.h>
  17
  18 #include "vfio_ccw_private.h"
  19
  20 static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
  21 {
  22         struct vfio_ccw_private *private;
  23         struct subchannel *sch;
  24         int ret;
  25
  26         private = dev_get_drvdata(mdev_parent_dev(mdev));
  27         sch = private->sch;
  28         /*
  29          * TODO:
  30          * In the cureent stage, some things like "no I/O running" and "no
  31          * interrupt pending" are clear, but we are not sure what other state
  32          * we need to care about.
  33          * There are still a lot more instructions need to be handled. We
  34          * should come back here later.
  35          */
  36         ret = vfio_ccw_sch_quiesce(sch);
  37         if (ret)
  38                 return ret;
  39
  40         ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
  41         if (!ret)
  42                 private->state = VFIO_CCW_STATE_IDLE;
  43
  44         return ret;
  45 }
  46
  47 static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
  48                                   unsigned long action,
  49                                   void *data)
  50 {
  51         struct vfio_ccw_private *private =
  52                 container_of(nb, struct vfio_ccw_private, nb);
  53
  54         /*
  55          * Vendor drivers MUST unpin pages in response to an
  56          * invalidation.
  57          */
  58         if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
  59                 struct vfio_iommu_type1_dma_unmap *unmap = data;
  60
  61                 if (!cp_iova_pinned(&private->cp, unmap->iova))
  62                         return NOTIFY_OK;
  63
  64                 if (vfio_ccw_mdev_reset(private->mdev))
  65                         return NOTIFY_BAD;
  66
  67                 cp_free(&private->cp);
  68                 return NOTIFY_OK;
  69         }
  70
  71         return NOTIFY_DONE;
  72 }
  73
  74 static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
  75 {
  76         return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
  77 }
  78 static MDEV_TYPE_ATTR_RO(name);
  79
  80 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
  81                                char *buf)
  82 {
  83         return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
  84 }
  85 static MDEV_TYPE_ATTR_RO(device_api);
  86
  87 static ssize_t available_instances_show(struct kobject *kobj,
  88                                         struct device *dev, char *buf)
  89 {
  90         struct vfio_ccw_private *private = dev_get_drvdata(dev);
  91
  92         return sprintf(buf, "%d\n", atomic_read(&private->avail));
  93 }
  94 static MDEV_TYPE_ATTR_RO(available_instances);
  95
  96 static struct attribute *mdev_types_attrs[] = {
  97         &mdev_type_attr_name.attr,
  98         &mdev_type_attr_device_api.attr,
  99         &mdev_type_attr_available_instances.attr,
 100         NULL,
 101 };
 102
 103 static struct attribute_group mdev_type_group = {
 104         .name  = "io",
 105         .attrs = mdev_types_attrs,
 106 };
 107
 108 static struct attribute_group *mdev_type_groups[] = {
 109         &mdev_type_group,
 110         NULL,
 111 };
 112
 113 static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
 114 {
 115         struct vfio_ccw_private *private =
 116                 dev_get_drvdata(mdev_parent_dev(mdev));
 117
 118         if (private->state == VFIO_CCW_STATE_NOT_OPER)
 119                 return -ENODEV;
 120
 121         if (atomic_dec_if_positive(&private->avail) < 0)
 122                 return -EPERM;
 123
 124         private->mdev = mdev;
 125         private->state = VFIO_CCW_STATE_IDLE;
 126
 127         VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: create\n",
 128                            mdev_uuid(mdev), private->sch->schid.cssid,
 129                            private->sch->schid.ssid,
 130                            private->sch->schid.sch_no);
 131
 132         return 0;
 133 }
 134
 135 static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
 136 {
 137         struct vfio_ccw_private *private =
 138                 dev_get_drvdata(mdev_parent_dev(mdev));
 139
 140         VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: remove\n",
 141                            mdev_uuid(mdev), private->sch->schid.cssid,
 142                            private->sch->schid.ssid,
 143                            private->sch->schid.sch_no);
 144
 145         if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
 146             (private->state != VFIO_CCW_STATE_STANDBY)) {
 147                 if (!vfio_ccw_sch_quiesce(private->sch))
 148                         private->state = VFIO_CCW_STATE_STANDBY;
 149                 /* The state will be NOT_OPER on error. */
 150         }
 151
 152         cp_free(&private->cp);
 153         private->mdev = NULL;
 154         atomic_inc(&private->avail);
 155
 156         return 0;
 157 }
 158
 159 static int vfio_ccw_mdev_open(struct mdev_device *mdev)
 160 {
 161         struct vfio_ccw_private *private =
 162                 dev_get_drvdata(mdev_parent_dev(mdev));
 163         unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
 164         int ret;
 165
 166         private->nb.notifier_call = vfio_ccw_mdev_notifier;
 167
 168         ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 169                                      &events, &private->nb);
 170         if (ret)
 171                 return ret;
 172
 173         ret = vfio_ccw_register_async_dev_regions(private);
 174         if (ret)
 175                 goto out_unregister;
 176
 177         ret = vfio_ccw_register_schib_dev_regions(private);
 178         if (ret)
 179                 goto out_unregister;
 180
 181         ret = vfio_ccw_register_crw_dev_regions(private);
 182         if (ret)
 183                 goto out_unregister;
 184
 185         return ret;
 186
 187 out_unregister:
 188         vfio_ccw_unregister_dev_regions(private);
 189         vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 190                                  &private->nb);
 191         return ret;
 192 }
 193
 194 static void vfio_ccw_mdev_release(struct mdev_device *mdev)
 195 {
 196         struct vfio_ccw_private *private =
 197                 dev_get_drvdata(mdev_parent_dev(mdev));
 198
 199         if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
 200             (private->state != VFIO_CCW_STATE_STANDBY)) {
 201                 if (!vfio_ccw_mdev_reset(mdev))
 202                         private->state = VFIO_CCW_STATE_STANDBY;
 203                 /* The state will be NOT_OPER on error. */
 204         }
 205
 206         cp_free(&private->cp);
 207         vfio_ccw_unregister_dev_regions(private);
 208         vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
 209                                  &private->nb);
 210 }
 211
 212 static ssize_t vfio_ccw_mdev_read_io_region(struct vfio_ccw_private *private,
 213                                             char __user *buf, size_t count,
 214                                             loff_t *ppos)
 215 {
 216         loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
 217         struct ccw_io_region *region;
 218         int ret;
 219
 220         if (pos + count > sizeof(*region))
 221                 return -EINVAL;
 222
 223         mutex_lock(&private->io_mutex);
 224         region = private->io_region;
 225         if (copy_to_user(buf, (void *)region + pos, count))
 226                 ret = -EFAULT;
 227         else
 228                 ret = count;
 229         mutex_unlock(&private->io_mutex);
 230         return ret;
 231 }
 232
 233 static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
 234                                   char __user *buf,
 235                                   size_t count,
 236                                   loff_t *ppos)
 237 {
 238         unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos);
 239         struct vfio_ccw_private *private;
 240
 241         private = dev_get_drvdata(mdev_parent_dev(mdev));
 242
 243         if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions)
 244                 return -EINVAL;
 245
 246         switch (index) {
 247         case VFIO_CCW_CONFIG_REGION_INDEX:
 248                 return vfio_ccw_mdev_read_io_region(private, buf, count, ppos);
 249         default:
 250                 index -= VFIO_CCW_NUM_REGIONS;
 251                 return private->region[index].ops->read(private, buf, count,
 252                                                         ppos);
 253         }
 254
 255         return -EINVAL;
 256 }
 257
 258 static ssize_t vfio_ccw_mdev_write_io_region(struct vfio_ccw_private *private,
 259                                              const char __user *buf,
 260                                              size_t count, loff_t *ppos)
 261 {
 262         loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
 263         struct ccw_io_region *region;
 264         int ret;
 265
 266         if (pos + count > sizeof(*region))
 267                 return -EINVAL;
 268
 269         if (!mutex_trylock(&private->io_mutex))
 270                 return -EAGAIN;
 271
 272         region = private->io_region;
 273         if (copy_from_user((void *)region + pos, buf, count)) {
 274                 ret = -EFAULT;
 275                 goto out_unlock;
 276         }
 277
 278         vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
 279         if (region->ret_code != 0)
 280                 private->state = VFIO_CCW_STATE_IDLE;
 281         ret = (region->ret_code != 0) ? region->ret_code : count;
 282
 283 out_unlock:
 284         mutex_unlock(&private->io_mutex);
 285         return ret;
 286 }
 287
 288 static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
 289                                    const char __user *buf,
 290                                    size_t count,
 291                                    loff_t *ppos)
 292 {
 293         unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos);
 294         struct vfio_ccw_private *private;
 295
 296         private = dev_get_drvdata(mdev_parent_dev(mdev));
 297
 298         if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions)
 299                 return -EINVAL;
 300
 301         switch (index) {
 302         case VFIO_CCW_CONFIG_REGION_INDEX:
 303                 return vfio_ccw_mdev_write_io_region(private, buf, count, ppos);
 304         default:
 305                 index -= VFIO_CCW_NUM_REGIONS;
 306                 return private->region[index].ops->write(private, buf, count,
 307                                                          ppos);
 308         }
 309
 310         return -EINVAL;
 311 }
 312
 313 static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info,
 314                                          struct mdev_device *mdev)
 315 {
 316         struct vfio_ccw_private *private;
 317
 318         private = dev_get_drvdata(mdev_parent_dev(mdev));
 319         info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
 320         info->num_regions = VFIO_CCW_NUM_REGIONS + private->num_regions;
 321         info->num_irqs = VFIO_CCW_NUM_IRQS;
 322
 323         return 0;
 324 }
 325
 326 static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
 327                                          struct mdev_device *mdev,
 328                                          unsigned long arg)
 329 {
 330         struct vfio_ccw_private *private;
 331         int i;
 332
 333         private = dev_get_drvdata(mdev_parent_dev(mdev));
 334         switch (info->index) {
 335         case VFIO_CCW_CONFIG_REGION_INDEX:
 336                 info->offset = 0;
 337                 info->size = sizeof(struct ccw_io_region);
 338                 info->flags = VFIO_REGION_INFO_FLAG_READ
 339                               | VFIO_REGION_INFO_FLAG_WRITE;
 340                 return 0;
 341         default: /* all other regions are handled via capability chain */
 342         {
 343                 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
 344                 struct vfio_region_info_cap_type cap_type = {
 345                         .header.id = VFIO_REGION_INFO_CAP_TYPE,
 346                         .header.version = 1 };
 347                 int ret;
 348
 349                 if (info->index >=
 350                     VFIO_CCW_NUM_REGIONS + private->num_regions)
 351                         return -EINVAL;
 352
 353                 info->index = array_index_nospec(info->index,
 354                                                  VFIO_CCW_NUM_REGIONS +
 355                                                  private->num_regions);
 356
 357                 i = info->index - VFIO_CCW_NUM_REGIONS;
 358
 359                 info->offset = VFIO_CCW_INDEX_TO_OFFSET(info->index);
 360                 info->size = private->region[i].size;
 361                 info->flags = private->region[i].flags;
 362
 363                 cap_type.type = private->region[i].type;
 364                 cap_type.subtype = private->region[i].subtype;
 365
 366                 ret = vfio_info_add_capability(&caps, &cap_type.header,
 367                                                sizeof(cap_type));
 368                 if (ret)
 369                         return ret;
 370
 371                 info->flags |= VFIO_REGION_INFO_FLAG_CAPS;
 372                 if (info->argsz < sizeof(*info) + caps.size) {
 373                         info->argsz = sizeof(*info) + caps.size;
 374                         info->cap_offset = 0;
 375                 } else {
 376                         vfio_info_cap_shift(&caps, sizeof(*info));
 377                         if (copy_to_user((void __user *)arg + sizeof(*info),
 378                                          caps.buf, caps.size)) {
 379                                 kfree(caps.buf);
 380                                 return -EFAULT;
 381                         }
 382                         info->cap_offset = sizeof(*info);
 383                 }
 384
 385                 kfree(caps.buf);
 386
 387         }
 388         }
 389         return 0;
 390 }
 391
 392 static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
 393 {
 394         switch (info->index) {
 395         case VFIO_CCW_IO_IRQ_INDEX:
 396         case VFIO_CCW_CRW_IRQ_INDEX:
 397         case VFIO_CCW_REQ_IRQ_INDEX:
 398                 info->count = 1;
 399                 info->flags = VFIO_IRQ_INFO_EVENTFD;
 400                 break;
 401         default:
 402                 return -EINVAL;
 403         }
 404
 405         return 0;
 406 }
 407
 408 static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
 409                                   uint32_t flags,
 410                                   uint32_t index,
 411                                   void __user *data)
 412 {
 413         struct vfio_ccw_private *private;
 414         struct eventfd_ctx **ctx;
 415
 416         if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
 417                 return -EINVAL;
 418
 419         private = dev_get_drvdata(mdev_parent_dev(mdev));
 420
 421         switch (index) {
 422         case VFIO_CCW_IO_IRQ_INDEX:
 423                 ctx = &private->io_trigger;
 424                 break;
 425         case VFIO_CCW_CRW_IRQ_INDEX:
 426                 ctx = &private->crw_trigger;
 427                 break;
 428         case VFIO_CCW_REQ_IRQ_INDEX:
 429                 ctx = &private->req_trigger;
 430                 break;
 431         default:
 432                 return -EINVAL;
 433         }
 434
 435         switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
 436         case VFIO_IRQ_SET_DATA_NONE:
 437         {
 438                 if (*ctx)
 439                         eventfd_signal(*ctx, 1);
 440                 return 0;
 441         }
 442         case VFIO_IRQ_SET_DATA_BOOL:
 443         {
 444                 uint8_t trigger;
 445
 446                 if (get_user(trigger, (uint8_t __user *)data))
 447                         return -EFAULT;
 448
 449                 if (trigger && *ctx)
 450                         eventfd_signal(*ctx, 1);
 451                 return 0;
 452         }
 453         case VFIO_IRQ_SET_DATA_EVENTFD:
 454         {
 455                 int32_t fd;
 456
 457                 if (get_user(fd, (int32_t __user *)data))
 458                         return -EFAULT;
 459
 460                 if (fd == -1) {
 461                         if (*ctx)
 462                                 eventfd_ctx_put(*ctx);
 463                         *ctx = NULL;
 464                 } else if (fd >= 0) {
 465                         struct eventfd_ctx *efdctx;
 466
 467                         efdctx = eventfd_ctx_fdget(fd);
 468                         if (IS_ERR(efdctx))
 469                                 return PTR_ERR(efdctx);
 470
 471                         if (*ctx)
 472                                 eventfd_ctx_put(*ctx);
 473
 474                         *ctx = efdctx;
 475                 } else
 476                         return -EINVAL;
 477
 478                 return 0;
 479         }
 480         default:
 481                 return -EINVAL;
 482         }
 483 }
 484
 485 int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
 486                                  unsigned int subtype,
 487                                  const struct vfio_ccw_regops *ops,
 488                                  size_t size, u32 flags, void *data)
 489 {
 490         struct vfio_ccw_region *region;
 491
 492         region = krealloc(private->region,
 493                           (private->num_regions + 1) * sizeof(*region),
 494                           GFP_KERNEL);
 495         if (!region)
 496                 return -ENOMEM;
 497
 498         private->region = region;
 499         private->region[private->num_regions].type = VFIO_REGION_TYPE_CCW;
 500         private->region[private->num_regions].subtype = subtype;
 501         private->region[private->num_regions].ops = ops;
 502         private->region[private->num_regions].size = size;
 503         private->region[private->num_regions].flags = flags;
 504         private->region[private->num_regions].data = data;
 505
 506         private->num_regions++;
 507
 508         return 0;
 509 }
 510
 511 void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private)
 512 {
 513         int i;
 514
 515         for (i = 0; i < private->num_regions; i++)
 516                 private->region[i].ops->release(private, &private->region[i]);
 517         private->num_regions = 0;
 518         kfree(private->region);
 519         private->region = NULL;
 520 }
 521
 522 static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
 523                                    unsigned int cmd,
 524                                    unsigned long arg)
 525 {
 526         int ret = 0;
 527         unsigned long minsz;
 528
 529         switch (cmd) {
 530         case VFIO_DEVICE_GET_INFO:
 531         {
 532                 struct vfio_device_info info;
 533
 534                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 535
 536                 if (copy_from_user(&info, (void __user *)arg, minsz))
 537                         return -EFAULT;
 538
 539                 if (info.argsz < minsz)
 540                         return -EINVAL;
 541
 542                 ret = vfio_ccw_mdev_get_device_info(&info, mdev);
 543                 if (ret)
 544                         return ret;
 545
 546                 return copy_to_user((void __user *)arg, &info, minsz);
 547         }
 548         case VFIO_DEVICE_GET_REGION_INFO:
 549         {
 550                 struct vfio_region_info info;
 551
 552                 minsz = offsetofend(struct vfio_region_info, offset);
 553
 554                 if (copy_from_user(&info, (void __user *)arg, minsz))
 555                         return -EFAULT;
 556
 557                 if (info.argsz < minsz)
 558                         return -EINVAL;
 559
 560                 ret = vfio_ccw_mdev_get_region_info(&info, mdev, arg);
 561                 if (ret)
 562                         return ret;
 563
 564                 return copy_to_user((void __user *)arg, &info, minsz);
 565         }
 566         case VFIO_DEVICE_GET_IRQ_INFO:
 567         {
 568                 struct vfio_irq_info info;
 569
 570                 minsz = offsetofend(struct vfio_irq_info, count);
 571
 572                 if (copy_from_user(&info, (void __user *)arg, minsz))
 573                         return -EFAULT;
 574
 575                 if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
 576                         return -EINVAL;
 577
 578                 ret = vfio_ccw_mdev_get_irq_info(&info);
 579                 if (ret)
 580                         return ret;
 581
 582                 if (info.count == -1)
 583                         return -EINVAL;
 584
 585                 return copy_to_user((void __user *)arg, &info, minsz);
 586         }
 587         case VFIO_DEVICE_SET_IRQS:
 588         {
 589                 struct vfio_irq_set hdr;
 590                 size_t data_size;
 591                 void __user *data;
 592
 593                 minsz = offsetofend(struct vfio_irq_set, count);
 594
 595                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 596                         return -EFAULT;
 597
 598                 ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
 599                                                          VFIO_CCW_NUM_IRQS,
 600                                                          &data_size);
 601                 if (ret)
 602                         return ret;
 603
 604                 data = (void __user *)(arg + minsz);
 605                 return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, hdr.index, data);
 606         }
 607         case VFIO_DEVICE_RESET:
 608                 return vfio_ccw_mdev_reset(mdev);
 609         default:
 610                 return -ENOTTY;
 611         }
 612 }
 613
 614 /* Request removal of the device*/
 615 static void vfio_ccw_mdev_request(struct mdev_device *mdev, unsigned int count)
 616 {
 617         struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev));
 618
 619         if (!private)
 620                 return;
 621
 622         if (private->req_trigger) {
 623                 if (!(count % 10))
 624                         dev_notice_ratelimited(mdev_dev(private->mdev),
 625                                                "Relaying device request to user (#%u)\n",
 626                                                count);
 627
 628                 eventfd_signal(private->req_trigger, 1);
 629         } else if (count == 0) {
 630                 dev_notice(mdev_dev(private->mdev),
 631                            "No device request channel registered, blocked until released by user\n");
 632         }
 633 }
 634
 635 static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
 636         .owner                  = THIS_MODULE,
 637         .supported_type_groups  = mdev_type_groups,
 638         .create                 = vfio_ccw_mdev_create,
 639         .remove                 = vfio_ccw_mdev_remove,
 640         .open                   = vfio_ccw_mdev_open,
 641         .release                = vfio_ccw_mdev_release,
 642         .read                   = vfio_ccw_mdev_read,
 643         .write                  = vfio_ccw_mdev_write,
 644         .ioctl                  = vfio_ccw_mdev_ioctl,
 645         .request                = vfio_ccw_mdev_request,
 646 };
 647
 648 int vfio_ccw_mdev_reg(struct subchannel *sch)
 649 {
 650         return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
 651 }
 652
 653 void vfio_ccw_mdev_unreg(struct subchannel *sch)
 654 {
 655         mdev_unregister_device(&sch->dev);
 656 }