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 const struct vfio_device_ops vfio_ccw_dev_ops; 21 22 static int vfio_ccw_mdev_reset(struct vfio_ccw_private *private) 23 { 24 /* 25 * If the FSM state is seen as Not Operational after closing 26 * and re-opening the mdev, return an error. 27 */ 28 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE); 29 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_OPEN); 30 if (private->state == VFIO_CCW_STATE_NOT_OPER) 31 return -EINVAL; 32 33 return 0; 34 } 35 36 static void vfio_ccw_dma_unmap(struct vfio_device *vdev, u64 iova, u64 length) 37 { 38 struct vfio_ccw_private *private = 39 container_of(vdev, struct vfio_ccw_private, vdev); 40 41 /* Drivers MUST unpin pages in response to an invalidation. */ 42 if (!cp_iova_pinned(&private->cp, iova, length)) 43 return; 44 45 vfio_ccw_mdev_reset(private); 46 } 47 48 static ssize_t name_show(struct mdev_type *mtype, 49 struct mdev_type_attribute *attr, char *buf) 50 { 51 return sprintf(buf, "I/O subchannel (Non-QDIO)\n"); 52 } 53 static MDEV_TYPE_ATTR_RO(name); 54 55 static ssize_t device_api_show(struct mdev_type *mtype, 56 struct mdev_type_attribute *attr, char *buf) 57 { 58 return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING); 59 } 60 static MDEV_TYPE_ATTR_RO(device_api); 61 62 static ssize_t available_instances_show(struct mdev_type *mtype, 63 struct mdev_type_attribute *attr, 64 char *buf) 65 { 66 struct vfio_ccw_private *private = 67 dev_get_drvdata(mtype_get_parent_dev(mtype)); 68 69 return sprintf(buf, "%d\n", atomic_read(&private->avail)); 70 } 71 static MDEV_TYPE_ATTR_RO(available_instances); 72 73 static struct attribute *mdev_types_attrs[] = { 74 &mdev_type_attr_name.attr, 75 &mdev_type_attr_device_api.attr, 76 &mdev_type_attr_available_instances.attr, 77 NULL, 78 }; 79 80 static struct attribute_group mdev_type_group = { 81 .name = "io", 82 .attrs = mdev_types_attrs, 83 }; 84 85 static struct attribute_group *mdev_type_groups[] = { 86 &mdev_type_group, 87 NULL, 88 }; 89 90 static int vfio_ccw_mdev_probe(struct mdev_device *mdev) 91 { 92 struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent); 93 int ret; 94 95 if (private->state == VFIO_CCW_STATE_NOT_OPER) 96 return -ENODEV; 97 98 if (atomic_dec_if_positive(&private->avail) < 0) 99 return -EPERM; 100 101 memset(&private->vdev, 0, sizeof(private->vdev)); 102 vfio_init_group_dev(&private->vdev, &mdev->dev, 103 &vfio_ccw_dev_ops); 104 105 VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n", 106 private->sch->schid.cssid, 107 private->sch->schid.ssid, 108 private->sch->schid.sch_no); 109 110 ret = vfio_register_emulated_iommu_dev(&private->vdev); 111 if (ret) 112 goto err_atomic; 113 dev_set_drvdata(&mdev->dev, private); 114 return 0; 115 116 err_atomic: 117 vfio_uninit_group_dev(&private->vdev); 118 atomic_inc(&private->avail); 119 return ret; 120 } 121 122 static void vfio_ccw_mdev_remove(struct mdev_device *mdev) 123 { 124 struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent); 125 126 VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: remove\n", 127 private->sch->schid.cssid, 128 private->sch->schid.ssid, 129 private->sch->schid.sch_no); 130 131 vfio_unregister_group_dev(&private->vdev); 132 133 vfio_uninit_group_dev(&private->vdev); 134 atomic_inc(&private->avail); 135 } 136 137 static int vfio_ccw_mdev_open_device(struct vfio_device *vdev) 138 { 139 struct vfio_ccw_private *private = 140 container_of(vdev, struct vfio_ccw_private, vdev); 141 int ret; 142 143 /* Device cannot simply be opened again from this state */ 144 if (private->state == VFIO_CCW_STATE_NOT_OPER) 145 return -EINVAL; 146 147 ret = vfio_ccw_register_async_dev_regions(private); 148 if (ret) 149 return ret; 150 151 ret = vfio_ccw_register_schib_dev_regions(private); 152 if (ret) 153 goto out_unregister; 154 155 ret = vfio_ccw_register_crw_dev_regions(private); 156 if (ret) 157 goto out_unregister; 158 159 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_OPEN); 160 if (private->state == VFIO_CCW_STATE_NOT_OPER) { 161 ret = -EINVAL; 162 goto out_unregister; 163 } 164 165 return ret; 166 167 out_unregister: 168 vfio_ccw_unregister_dev_regions(private); 169 return ret; 170 } 171 172 static void vfio_ccw_mdev_close_device(struct vfio_device *vdev) 173 { 174 struct vfio_ccw_private *private = 175 container_of(vdev, struct vfio_ccw_private, vdev); 176 177 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE); 178 vfio_ccw_unregister_dev_regions(private); 179 } 180 181 static ssize_t vfio_ccw_mdev_read_io_region(struct vfio_ccw_private *private, 182 char __user *buf, size_t count, 183 loff_t *ppos) 184 { 185 loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK; 186 struct ccw_io_region *region; 187 int ret; 188 189 if (pos + count > sizeof(*region)) 190 return -EINVAL; 191 192 mutex_lock(&private->io_mutex); 193 region = private->io_region; 194 if (copy_to_user(buf, (void *)region + pos, count)) 195 ret = -EFAULT; 196 else 197 ret = count; 198 mutex_unlock(&private->io_mutex); 199 return ret; 200 } 201 202 static ssize_t vfio_ccw_mdev_read(struct vfio_device *vdev, 203 char __user *buf, 204 size_t count, 205 loff_t *ppos) 206 { 207 struct vfio_ccw_private *private = 208 container_of(vdev, struct vfio_ccw_private, vdev); 209 unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos); 210 211 if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions) 212 return -EINVAL; 213 214 switch (index) { 215 case VFIO_CCW_CONFIG_REGION_INDEX: 216 return vfio_ccw_mdev_read_io_region(private, buf, count, ppos); 217 default: 218 index -= VFIO_CCW_NUM_REGIONS; 219 return private->region[index].ops->read(private, buf, count, 220 ppos); 221 } 222 223 return -EINVAL; 224 } 225 226 static ssize_t vfio_ccw_mdev_write_io_region(struct vfio_ccw_private *private, 227 const char __user *buf, 228 size_t count, loff_t *ppos) 229 { 230 loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK; 231 struct ccw_io_region *region; 232 int ret; 233 234 if (pos + count > sizeof(*region)) 235 return -EINVAL; 236 237 if (!mutex_trylock(&private->io_mutex)) 238 return -EAGAIN; 239 240 region = private->io_region; 241 if (copy_from_user((void *)region + pos, buf, count)) { 242 ret = -EFAULT; 243 goto out_unlock; 244 } 245 246 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ); 247 ret = (region->ret_code != 0) ? region->ret_code : count; 248 249 out_unlock: 250 mutex_unlock(&private->io_mutex); 251 return ret; 252 } 253 254 static ssize_t vfio_ccw_mdev_write(struct vfio_device *vdev, 255 const char __user *buf, 256 size_t count, 257 loff_t *ppos) 258 { 259 struct vfio_ccw_private *private = 260 container_of(vdev, struct vfio_ccw_private, vdev); 261 unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos); 262 263 if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions) 264 return -EINVAL; 265 266 switch (index) { 267 case VFIO_CCW_CONFIG_REGION_INDEX: 268 return vfio_ccw_mdev_write_io_region(private, buf, count, ppos); 269 default: 270 index -= VFIO_CCW_NUM_REGIONS; 271 return private->region[index].ops->write(private, buf, count, 272 ppos); 273 } 274 275 return -EINVAL; 276 } 277 278 static int vfio_ccw_mdev_get_device_info(struct vfio_ccw_private *private, 279 struct vfio_device_info *info) 280 { 281 info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET; 282 info->num_regions = VFIO_CCW_NUM_REGIONS + private->num_regions; 283 info->num_irqs = VFIO_CCW_NUM_IRQS; 284 285 return 0; 286 } 287 288 static int vfio_ccw_mdev_get_region_info(struct vfio_ccw_private *private, 289 struct vfio_region_info *info, 290 unsigned long arg) 291 { 292 int i; 293 294 switch (info->index) { 295 case VFIO_CCW_CONFIG_REGION_INDEX: 296 info->offset = 0; 297 info->size = sizeof(struct ccw_io_region); 298 info->flags = VFIO_REGION_INFO_FLAG_READ 299 | VFIO_REGION_INFO_FLAG_WRITE; 300 return 0; 301 default: /* all other regions are handled via capability chain */ 302 { 303 struct vfio_info_cap caps = { .buf = NULL, .size = 0 }; 304 struct vfio_region_info_cap_type cap_type = { 305 .header.id = VFIO_REGION_INFO_CAP_TYPE, 306 .header.version = 1 }; 307 int ret; 308 309 if (info->index >= 310 VFIO_CCW_NUM_REGIONS + private->num_regions) 311 return -EINVAL; 312 313 info->index = array_index_nospec(info->index, 314 VFIO_CCW_NUM_REGIONS + 315 private->num_regions); 316 317 i = info->index - VFIO_CCW_NUM_REGIONS; 318 319 info->offset = VFIO_CCW_INDEX_TO_OFFSET(info->index); 320 info->size = private->region[i].size; 321 info->flags = private->region[i].flags; 322 323 cap_type.type = private->region[i].type; 324 cap_type.subtype = private->region[i].subtype; 325 326 ret = vfio_info_add_capability(&caps, &cap_type.header, 327 sizeof(cap_type)); 328 if (ret) 329 return ret; 330 331 info->flags |= VFIO_REGION_INFO_FLAG_CAPS; 332 if (info->argsz < sizeof(*info) + caps.size) { 333 info->argsz = sizeof(*info) + caps.size; 334 info->cap_offset = 0; 335 } else { 336 vfio_info_cap_shift(&caps, sizeof(*info)); 337 if (copy_to_user((void __user *)arg + sizeof(*info), 338 caps.buf, caps.size)) { 339 kfree(caps.buf); 340 return -EFAULT; 341 } 342 info->cap_offset = sizeof(*info); 343 } 344 345 kfree(caps.buf); 346 347 } 348 } 349 return 0; 350 } 351 352 static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info) 353 { 354 switch (info->index) { 355 case VFIO_CCW_IO_IRQ_INDEX: 356 case VFIO_CCW_CRW_IRQ_INDEX: 357 case VFIO_CCW_REQ_IRQ_INDEX: 358 info->count = 1; 359 info->flags = VFIO_IRQ_INFO_EVENTFD; 360 break; 361 default: 362 return -EINVAL; 363 } 364 365 return 0; 366 } 367 368 static int vfio_ccw_mdev_set_irqs(struct vfio_ccw_private *private, 369 uint32_t flags, 370 uint32_t index, 371 void __user *data) 372 { 373 struct eventfd_ctx **ctx; 374 375 if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER)) 376 return -EINVAL; 377 378 switch (index) { 379 case VFIO_CCW_IO_IRQ_INDEX: 380 ctx = &private->io_trigger; 381 break; 382 case VFIO_CCW_CRW_IRQ_INDEX: 383 ctx = &private->crw_trigger; 384 break; 385 case VFIO_CCW_REQ_IRQ_INDEX: 386 ctx = &private->req_trigger; 387 break; 388 default: 389 return -EINVAL; 390 } 391 392 switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) { 393 case VFIO_IRQ_SET_DATA_NONE: 394 { 395 if (*ctx) 396 eventfd_signal(*ctx, 1); 397 return 0; 398 } 399 case VFIO_IRQ_SET_DATA_BOOL: 400 { 401 uint8_t trigger; 402 403 if (get_user(trigger, (uint8_t __user *)data)) 404 return -EFAULT; 405 406 if (trigger && *ctx) 407 eventfd_signal(*ctx, 1); 408 return 0; 409 } 410 case VFIO_IRQ_SET_DATA_EVENTFD: 411 { 412 int32_t fd; 413 414 if (get_user(fd, (int32_t __user *)data)) 415 return -EFAULT; 416 417 if (fd == -1) { 418 if (*ctx) 419 eventfd_ctx_put(*ctx); 420 *ctx = NULL; 421 } else if (fd >= 0) { 422 struct eventfd_ctx *efdctx; 423 424 efdctx = eventfd_ctx_fdget(fd); 425 if (IS_ERR(efdctx)) 426 return PTR_ERR(efdctx); 427 428 if (*ctx) 429 eventfd_ctx_put(*ctx); 430 431 *ctx = efdctx; 432 } else 433 return -EINVAL; 434 435 return 0; 436 } 437 default: 438 return -EINVAL; 439 } 440 } 441 442 int vfio_ccw_register_dev_region(struct vfio_ccw_private *private, 443 unsigned int subtype, 444 const struct vfio_ccw_regops *ops, 445 size_t size, u32 flags, void *data) 446 { 447 struct vfio_ccw_region *region; 448 449 region = krealloc(private->region, 450 (private->num_regions + 1) * sizeof(*region), 451 GFP_KERNEL); 452 if (!region) 453 return -ENOMEM; 454 455 private->region = region; 456 private->region[private->num_regions].type = VFIO_REGION_TYPE_CCW; 457 private->region[private->num_regions].subtype = subtype; 458 private->region[private->num_regions].ops = ops; 459 private->region[private->num_regions].size = size; 460 private->region[private->num_regions].flags = flags; 461 private->region[private->num_regions].data = data; 462 463 private->num_regions++; 464 465 return 0; 466 } 467 468 void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private) 469 { 470 int i; 471 472 for (i = 0; i < private->num_regions; i++) 473 private->region[i].ops->release(private, &private->region[i]); 474 private->num_regions = 0; 475 kfree(private->region); 476 private->region = NULL; 477 } 478 479 static ssize_t vfio_ccw_mdev_ioctl(struct vfio_device *vdev, 480 unsigned int cmd, 481 unsigned long arg) 482 { 483 struct vfio_ccw_private *private = 484 container_of(vdev, struct vfio_ccw_private, vdev); 485 int ret = 0; 486 unsigned long minsz; 487 488 switch (cmd) { 489 case VFIO_DEVICE_GET_INFO: 490 { 491 struct vfio_device_info info; 492 493 minsz = offsetofend(struct vfio_device_info, num_irqs); 494 495 if (copy_from_user(&info, (void __user *)arg, minsz)) 496 return -EFAULT; 497 498 if (info.argsz < minsz) 499 return -EINVAL; 500 501 ret = vfio_ccw_mdev_get_device_info(private, &info); 502 if (ret) 503 return ret; 504 505 return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0; 506 } 507 case VFIO_DEVICE_GET_REGION_INFO: 508 { 509 struct vfio_region_info info; 510 511 minsz = offsetofend(struct vfio_region_info, offset); 512 513 if (copy_from_user(&info, (void __user *)arg, minsz)) 514 return -EFAULT; 515 516 if (info.argsz < minsz) 517 return -EINVAL; 518 519 ret = vfio_ccw_mdev_get_region_info(private, &info, arg); 520 if (ret) 521 return ret; 522 523 return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0; 524 } 525 case VFIO_DEVICE_GET_IRQ_INFO: 526 { 527 struct vfio_irq_info info; 528 529 minsz = offsetofend(struct vfio_irq_info, count); 530 531 if (copy_from_user(&info, (void __user *)arg, minsz)) 532 return -EFAULT; 533 534 if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS) 535 return -EINVAL; 536 537 ret = vfio_ccw_mdev_get_irq_info(&info); 538 if (ret) 539 return ret; 540 541 if (info.count == -1) 542 return -EINVAL; 543 544 return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0; 545 } 546 case VFIO_DEVICE_SET_IRQS: 547 { 548 struct vfio_irq_set hdr; 549 size_t data_size; 550 void __user *data; 551 552 minsz = offsetofend(struct vfio_irq_set, count); 553 554 if (copy_from_user(&hdr, (void __user *)arg, minsz)) 555 return -EFAULT; 556 557 ret = vfio_set_irqs_validate_and_prepare(&hdr, 1, 558 VFIO_CCW_NUM_IRQS, 559 &data_size); 560 if (ret) 561 return ret; 562 563 data = (void __user *)(arg + minsz); 564 return vfio_ccw_mdev_set_irqs(private, hdr.flags, hdr.index, 565 data); 566 } 567 case VFIO_DEVICE_RESET: 568 return vfio_ccw_mdev_reset(private); 569 default: 570 return -ENOTTY; 571 } 572 } 573 574 /* Request removal of the device*/ 575 static void vfio_ccw_mdev_request(struct vfio_device *vdev, unsigned int count) 576 { 577 struct vfio_ccw_private *private = 578 container_of(vdev, struct vfio_ccw_private, vdev); 579 struct device *dev = vdev->dev; 580 581 if (private->req_trigger) { 582 if (!(count % 10)) 583 dev_notice_ratelimited(dev, 584 "Relaying device request to user (#%u)\n", 585 count); 586 587 eventfd_signal(private->req_trigger, 1); 588 } else if (count == 0) { 589 dev_notice(dev, 590 "No device request channel registered, blocked until released by user\n"); 591 } 592 } 593 594 static const struct vfio_device_ops vfio_ccw_dev_ops = { 595 .open_device = vfio_ccw_mdev_open_device, 596 .close_device = vfio_ccw_mdev_close_device, 597 .read = vfio_ccw_mdev_read, 598 .write = vfio_ccw_mdev_write, 599 .ioctl = vfio_ccw_mdev_ioctl, 600 .request = vfio_ccw_mdev_request, 601 .dma_unmap = vfio_ccw_dma_unmap, 602 }; 603 604 struct mdev_driver vfio_ccw_mdev_driver = { 605 .driver = { 606 .name = "vfio_ccw_mdev", 607 .owner = THIS_MODULE, 608 .mod_name = KBUILD_MODNAME, 609 }, 610 .probe = vfio_ccw_mdev_probe, 611 .remove = vfio_ccw_mdev_remove, 612 .supported_type_groups = mdev_type_groups, 613 }; 614