1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * VFIO core 4 * 5 * Copyright (C) 2012 Red Hat, Inc. All rights reserved. 6 * Author: Alex Williamson <alex.williamson@redhat.com> 7 * 8 * Derived from original vfio: 9 * Copyright 2010 Cisco Systems, Inc. All rights reserved. 10 * Author: Tom Lyon, pugs@cisco.com 11 */ 12 13 #include <linux/cdev.h> 14 #include <linux/compat.h> 15 #include <linux/device.h> 16 #include <linux/file.h> 17 #include <linux/anon_inodes.h> 18 #include <linux/fs.h> 19 #include <linux/idr.h> 20 #include <linux/iommu.h> 21 #include <linux/list.h> 22 #include <linux/miscdevice.h> 23 #include <linux/module.h> 24 #include <linux/mutex.h> 25 #include <linux/pci.h> 26 #include <linux/rwsem.h> 27 #include <linux/sched.h> 28 #include <linux/slab.h> 29 #include <linux/stat.h> 30 #include <linux/string.h> 31 #include <linux/uaccess.h> 32 #include <linux/vfio.h> 33 #include <linux/wait.h> 34 #include <linux/sched/signal.h> 35 #include <linux/pm_runtime.h> 36 #include <linux/interval_tree.h> 37 #include <linux/iova_bitmap.h> 38 #include "vfio.h" 39 40 #define DRIVER_VERSION "0.3" 41 #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" 42 #define DRIVER_DESC "VFIO - User Level meta-driver" 43 44 static struct vfio { 45 struct class *class; 46 struct list_head group_list; 47 struct mutex group_lock; /* locks group_list */ 48 struct ida group_ida; 49 dev_t group_devt; 50 struct class *device_class; 51 struct ida device_ida; 52 } vfio; 53 54 static DEFINE_XARRAY(vfio_device_set_xa); 55 static const struct file_operations vfio_group_fops; 56 57 int vfio_assign_device_set(struct vfio_device *device, void *set_id) 58 { 59 unsigned long idx = (unsigned long)set_id; 60 struct vfio_device_set *new_dev_set; 61 struct vfio_device_set *dev_set; 62 63 if (WARN_ON(!set_id)) 64 return -EINVAL; 65 66 /* 67 * Atomically acquire a singleton object in the xarray for this set_id 68 */ 69 xa_lock(&vfio_device_set_xa); 70 dev_set = xa_load(&vfio_device_set_xa, idx); 71 if (dev_set) 72 goto found_get_ref; 73 xa_unlock(&vfio_device_set_xa); 74 75 new_dev_set = kzalloc(sizeof(*new_dev_set), GFP_KERNEL); 76 if (!new_dev_set) 77 return -ENOMEM; 78 mutex_init(&new_dev_set->lock); 79 INIT_LIST_HEAD(&new_dev_set->device_list); 80 new_dev_set->set_id = set_id; 81 82 xa_lock(&vfio_device_set_xa); 83 dev_set = __xa_cmpxchg(&vfio_device_set_xa, idx, NULL, new_dev_set, 84 GFP_KERNEL); 85 if (!dev_set) { 86 dev_set = new_dev_set; 87 goto found_get_ref; 88 } 89 90 kfree(new_dev_set); 91 if (xa_is_err(dev_set)) { 92 xa_unlock(&vfio_device_set_xa); 93 return xa_err(dev_set); 94 } 95 96 found_get_ref: 97 dev_set->device_count++; 98 xa_unlock(&vfio_device_set_xa); 99 mutex_lock(&dev_set->lock); 100 device->dev_set = dev_set; 101 list_add_tail(&device->dev_set_list, &dev_set->device_list); 102 mutex_unlock(&dev_set->lock); 103 return 0; 104 } 105 EXPORT_SYMBOL_GPL(vfio_assign_device_set); 106 107 static void vfio_release_device_set(struct vfio_device *device) 108 { 109 struct vfio_device_set *dev_set = device->dev_set; 110 111 if (!dev_set) 112 return; 113 114 mutex_lock(&dev_set->lock); 115 list_del(&device->dev_set_list); 116 mutex_unlock(&dev_set->lock); 117 118 xa_lock(&vfio_device_set_xa); 119 if (!--dev_set->device_count) { 120 __xa_erase(&vfio_device_set_xa, 121 (unsigned long)dev_set->set_id); 122 mutex_destroy(&dev_set->lock); 123 kfree(dev_set); 124 } 125 xa_unlock(&vfio_device_set_xa); 126 } 127 128 /* 129 * Group objects - create, release, get, put, search 130 */ 131 static struct vfio_group * 132 __vfio_group_get_from_iommu(struct iommu_group *iommu_group) 133 { 134 struct vfio_group *group; 135 136 /* 137 * group->iommu_group from the vfio.group_list cannot be NULL 138 * under the vfio.group_lock. 139 */ 140 list_for_each_entry(group, &vfio.group_list, vfio_next) { 141 if (group->iommu_group == iommu_group) { 142 refcount_inc(&group->drivers); 143 return group; 144 } 145 } 146 return NULL; 147 } 148 149 static struct vfio_group * 150 vfio_group_get_from_iommu(struct iommu_group *iommu_group) 151 { 152 struct vfio_group *group; 153 154 mutex_lock(&vfio.group_lock); 155 group = __vfio_group_get_from_iommu(iommu_group); 156 mutex_unlock(&vfio.group_lock); 157 return group; 158 } 159 160 static void vfio_group_release(struct device *dev) 161 { 162 struct vfio_group *group = container_of(dev, struct vfio_group, dev); 163 164 mutex_destroy(&group->device_lock); 165 mutex_destroy(&group->group_lock); 166 WARN_ON(group->iommu_group); 167 ida_free(&vfio.group_ida, MINOR(group->dev.devt)); 168 kfree(group); 169 } 170 171 static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, 172 enum vfio_group_type type) 173 { 174 struct vfio_group *group; 175 int minor; 176 177 group = kzalloc(sizeof(*group), GFP_KERNEL); 178 if (!group) 179 return ERR_PTR(-ENOMEM); 180 181 minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL); 182 if (minor < 0) { 183 kfree(group); 184 return ERR_PTR(minor); 185 } 186 187 device_initialize(&group->dev); 188 group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor); 189 group->dev.class = vfio.class; 190 group->dev.release = vfio_group_release; 191 cdev_init(&group->cdev, &vfio_group_fops); 192 group->cdev.owner = THIS_MODULE; 193 194 refcount_set(&group->drivers, 1); 195 mutex_init(&group->group_lock); 196 INIT_LIST_HEAD(&group->device_list); 197 mutex_init(&group->device_lock); 198 group->iommu_group = iommu_group; 199 /* put in vfio_group_release() */ 200 iommu_group_ref_get(iommu_group); 201 group->type = type; 202 BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier); 203 204 return group; 205 } 206 207 static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, 208 enum vfio_group_type type) 209 { 210 struct vfio_group *group; 211 struct vfio_group *ret; 212 int err; 213 214 group = vfio_group_alloc(iommu_group, type); 215 if (IS_ERR(group)) 216 return group; 217 218 err = dev_set_name(&group->dev, "%s%d", 219 group->type == VFIO_NO_IOMMU ? "noiommu-" : "", 220 iommu_group_id(iommu_group)); 221 if (err) { 222 ret = ERR_PTR(err); 223 goto err_put; 224 } 225 226 mutex_lock(&vfio.group_lock); 227 228 /* Did we race creating this group? */ 229 ret = __vfio_group_get_from_iommu(iommu_group); 230 if (ret) 231 goto err_unlock; 232 233 err = cdev_device_add(&group->cdev, &group->dev); 234 if (err) { 235 ret = ERR_PTR(err); 236 goto err_unlock; 237 } 238 239 list_add(&group->vfio_next, &vfio.group_list); 240 241 mutex_unlock(&vfio.group_lock); 242 return group; 243 244 err_unlock: 245 mutex_unlock(&vfio.group_lock); 246 err_put: 247 put_device(&group->dev); 248 return ret; 249 } 250 251 static void vfio_device_remove_group(struct vfio_device *device) 252 { 253 struct vfio_group *group = device->group; 254 struct iommu_group *iommu_group; 255 256 if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) 257 iommu_group_remove_device(device->dev); 258 259 /* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */ 260 if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock)) 261 return; 262 list_del(&group->vfio_next); 263 264 /* 265 * We could concurrently probe another driver in the group that might 266 * race vfio_device_remove_group() with vfio_get_group(), so we have to 267 * ensure that the sysfs is all cleaned up under lock otherwise the 268 * cdev_device_add() will fail due to the name aready existing. 269 */ 270 cdev_device_del(&group->cdev, &group->dev); 271 272 mutex_lock(&group->group_lock); 273 /* 274 * These data structures all have paired operations that can only be 275 * undone when the caller holds a live reference on the device. Since 276 * all pairs must be undone these WARN_ON's indicate some caller did not 277 * properly hold the group reference. 278 */ 279 WARN_ON(!list_empty(&group->device_list)); 280 WARN_ON(group->notifier.head); 281 282 /* 283 * Revoke all users of group->iommu_group. At this point we know there 284 * are no devices active because we are unplugging the last one. Setting 285 * iommu_group to NULL blocks all new users. 286 */ 287 if (group->container) 288 vfio_group_detach_container(group); 289 iommu_group = group->iommu_group; 290 group->iommu_group = NULL; 291 mutex_unlock(&group->group_lock); 292 mutex_unlock(&vfio.group_lock); 293 294 iommu_group_put(iommu_group); 295 put_device(&group->dev); 296 } 297 298 /* 299 * Device objects - create, release, get, put, search 300 */ 301 /* Device reference always implies a group reference */ 302 static void vfio_device_put_registration(struct vfio_device *device) 303 { 304 if (refcount_dec_and_test(&device->refcount)) 305 complete(&device->comp); 306 } 307 308 static bool vfio_device_try_get_registration(struct vfio_device *device) 309 { 310 return refcount_inc_not_zero(&device->refcount); 311 } 312 313 static struct vfio_device *vfio_group_get_device(struct vfio_group *group, 314 struct device *dev) 315 { 316 struct vfio_device *device; 317 318 mutex_lock(&group->device_lock); 319 list_for_each_entry(device, &group->device_list, group_next) { 320 if (device->dev == dev && 321 vfio_device_try_get_registration(device)) { 322 mutex_unlock(&group->device_lock); 323 return device; 324 } 325 } 326 mutex_unlock(&group->device_lock); 327 return NULL; 328 } 329 330 /* 331 * VFIO driver API 332 */ 333 /* Release helper called by vfio_put_device() */ 334 static void vfio_device_release(struct device *dev) 335 { 336 struct vfio_device *device = 337 container_of(dev, struct vfio_device, device); 338 339 vfio_release_device_set(device); 340 ida_free(&vfio.device_ida, device->index); 341 342 /* 343 * kvfree() cannot be done here due to a life cycle mess in 344 * vfio-ccw. Before the ccw part is fixed all drivers are 345 * required to support @release and call vfio_free_device() 346 * from there. 347 */ 348 device->ops->release(device); 349 } 350 351 /* 352 * Allocate and initialize vfio_device so it can be registered to vfio 353 * core. 354 * 355 * Drivers should use the wrapper vfio_alloc_device() for allocation. 356 * @size is the size of the structure to be allocated, including any 357 * private data used by the driver. 358 * 359 * Driver may provide an @init callback to cover device private data. 360 * 361 * Use vfio_put_device() to release the structure after success return. 362 */ 363 struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, 364 const struct vfio_device_ops *ops) 365 { 366 struct vfio_device *device; 367 int ret; 368 369 if (WARN_ON(size < sizeof(struct vfio_device))) 370 return ERR_PTR(-EINVAL); 371 372 device = kvzalloc(size, GFP_KERNEL); 373 if (!device) 374 return ERR_PTR(-ENOMEM); 375 376 ret = vfio_init_device(device, dev, ops); 377 if (ret) 378 goto out_free; 379 return device; 380 381 out_free: 382 kvfree(device); 383 return ERR_PTR(ret); 384 } 385 EXPORT_SYMBOL_GPL(_vfio_alloc_device); 386 387 /* 388 * Initialize a vfio_device so it can be registered to vfio core. 389 * 390 * Only vfio-ccw driver should call this interface. 391 */ 392 int vfio_init_device(struct vfio_device *device, struct device *dev, 393 const struct vfio_device_ops *ops) 394 { 395 int ret; 396 397 ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); 398 if (ret < 0) { 399 dev_dbg(dev, "Error to alloc index\n"); 400 return ret; 401 } 402 403 device->index = ret; 404 init_completion(&device->comp); 405 device->dev = dev; 406 device->ops = ops; 407 408 if (ops->init) { 409 ret = ops->init(device); 410 if (ret) 411 goto out_uninit; 412 } 413 414 device_initialize(&device->device); 415 device->device.release = vfio_device_release; 416 device->device.class = vfio.device_class; 417 device->device.parent = device->dev; 418 return 0; 419 420 out_uninit: 421 vfio_release_device_set(device); 422 ida_free(&vfio.device_ida, device->index); 423 return ret; 424 } 425 EXPORT_SYMBOL_GPL(vfio_init_device); 426 427 /* 428 * The helper called by driver @release callback to free the device 429 * structure. Drivers which don't have private data to clean can 430 * simply use this helper as its @release. 431 */ 432 void vfio_free_device(struct vfio_device *device) 433 { 434 kvfree(device); 435 } 436 EXPORT_SYMBOL_GPL(vfio_free_device); 437 438 static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev, 439 enum vfio_group_type type) 440 { 441 struct iommu_group *iommu_group; 442 struct vfio_group *group; 443 int ret; 444 445 iommu_group = iommu_group_alloc(); 446 if (IS_ERR(iommu_group)) 447 return ERR_CAST(iommu_group); 448 449 ret = iommu_group_set_name(iommu_group, "vfio-noiommu"); 450 if (ret) 451 goto out_put_group; 452 ret = iommu_group_add_device(iommu_group, dev); 453 if (ret) 454 goto out_put_group; 455 456 group = vfio_create_group(iommu_group, type); 457 if (IS_ERR(group)) { 458 ret = PTR_ERR(group); 459 goto out_remove_device; 460 } 461 iommu_group_put(iommu_group); 462 return group; 463 464 out_remove_device: 465 iommu_group_remove_device(dev); 466 out_put_group: 467 iommu_group_put(iommu_group); 468 return ERR_PTR(ret); 469 } 470 471 static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) 472 { 473 struct iommu_group *iommu_group; 474 struct vfio_group *group; 475 476 iommu_group = iommu_group_get(dev); 477 if (!iommu_group && vfio_noiommu) { 478 /* 479 * With noiommu enabled, create an IOMMU group for devices that 480 * don't already have one, implying no IOMMU hardware/driver 481 * exists. Taint the kernel because we're about to give a DMA 482 * capable device to a user without IOMMU protection. 483 */ 484 group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU); 485 if (!IS_ERR(group)) { 486 add_taint(TAINT_USER, LOCKDEP_STILL_OK); 487 dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n"); 488 } 489 return group; 490 } 491 492 if (!iommu_group) 493 return ERR_PTR(-EINVAL); 494 495 /* 496 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to 497 * restore cache coherency. It has to be checked here because it is only 498 * valid for cases where we are using iommu groups. 499 */ 500 if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) { 501 iommu_group_put(iommu_group); 502 return ERR_PTR(-EINVAL); 503 } 504 505 group = vfio_group_get_from_iommu(iommu_group); 506 if (!group) 507 group = vfio_create_group(iommu_group, VFIO_IOMMU); 508 509 /* The vfio_group holds a reference to the iommu_group */ 510 iommu_group_put(iommu_group); 511 return group; 512 } 513 514 static int __vfio_register_dev(struct vfio_device *device, 515 struct vfio_group *group) 516 { 517 struct vfio_device *existing_device; 518 int ret; 519 520 /* 521 * In all cases group is the output of one of the group allocation 522 * functions and we have group->drivers incremented for us. 523 */ 524 if (IS_ERR(group)) 525 return PTR_ERR(group); 526 527 /* 528 * If the driver doesn't specify a set then the device is added to a 529 * singleton set just for itself. 530 */ 531 if (!device->dev_set) 532 vfio_assign_device_set(device, device); 533 534 existing_device = vfio_group_get_device(group, device->dev); 535 if (existing_device) { 536 /* 537 * group->iommu_group is non-NULL because we hold the drivers 538 * refcount. 539 */ 540 dev_WARN(device->dev, "Device already exists on group %d\n", 541 iommu_group_id(group->iommu_group)); 542 vfio_device_put_registration(existing_device); 543 ret = -EBUSY; 544 goto err_out; 545 } 546 547 /* Our reference on group is moved to the device */ 548 device->group = group; 549 550 ret = dev_set_name(&device->device, "vfio%d", device->index); 551 if (ret) 552 goto err_out; 553 554 ret = device_add(&device->device); 555 if (ret) 556 goto err_out; 557 558 /* Refcounting can't start until the driver calls register */ 559 refcount_set(&device->refcount, 1); 560 561 mutex_lock(&group->device_lock); 562 list_add(&device->group_next, &group->device_list); 563 mutex_unlock(&group->device_lock); 564 565 return 0; 566 err_out: 567 vfio_device_remove_group(device); 568 return ret; 569 } 570 571 int vfio_register_group_dev(struct vfio_device *device) 572 { 573 return __vfio_register_dev(device, 574 vfio_group_find_or_alloc(device->dev)); 575 } 576 EXPORT_SYMBOL_GPL(vfio_register_group_dev); 577 578 /* 579 * Register a virtual device without IOMMU backing. The user of this 580 * device must not be able to directly trigger unmediated DMA. 581 */ 582 int vfio_register_emulated_iommu_dev(struct vfio_device *device) 583 { 584 return __vfio_register_dev(device, 585 vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU)); 586 } 587 EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev); 588 589 static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, 590 char *buf) 591 { 592 struct vfio_device *it, *device = ERR_PTR(-ENODEV); 593 594 mutex_lock(&group->device_lock); 595 list_for_each_entry(it, &group->device_list, group_next) { 596 int ret; 597 598 if (it->ops->match) { 599 ret = it->ops->match(it, buf); 600 if (ret < 0) { 601 device = ERR_PTR(ret); 602 break; 603 } 604 } else { 605 ret = !strcmp(dev_name(it->dev), buf); 606 } 607 608 if (ret && vfio_device_try_get_registration(it)) { 609 device = it; 610 break; 611 } 612 } 613 mutex_unlock(&group->device_lock); 614 615 return device; 616 } 617 618 /* 619 * Decrement the device reference count and wait for the device to be 620 * removed. Open file descriptors for the device... */ 621 void vfio_unregister_group_dev(struct vfio_device *device) 622 { 623 struct vfio_group *group = device->group; 624 unsigned int i = 0; 625 bool interrupted = false; 626 long rc; 627 628 vfio_device_put_registration(device); 629 rc = try_wait_for_completion(&device->comp); 630 while (rc <= 0) { 631 if (device->ops->request) 632 device->ops->request(device, i++); 633 634 if (interrupted) { 635 rc = wait_for_completion_timeout(&device->comp, 636 HZ * 10); 637 } else { 638 rc = wait_for_completion_interruptible_timeout( 639 &device->comp, HZ * 10); 640 if (rc < 0) { 641 interrupted = true; 642 dev_warn(device->dev, 643 "Device is currently in use, task" 644 " \"%s\" (%d) " 645 "blocked until device is released", 646 current->comm, task_pid_nr(current)); 647 } 648 } 649 } 650 651 mutex_lock(&group->device_lock); 652 list_del(&device->group_next); 653 mutex_unlock(&group->device_lock); 654 655 /* Balances device_add in register path */ 656 device_del(&device->device); 657 658 vfio_device_remove_group(device); 659 } 660 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev); 661 662 /* 663 * VFIO Group fd, /dev/vfio/$GROUP 664 */ 665 /* 666 * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or 667 * if there was no container to unset. Since the ioctl is called on 668 * the group, we know that still exists, therefore the only valid 669 * transition here is 1->0. 670 */ 671 static int vfio_group_ioctl_unset_container(struct vfio_group *group) 672 { 673 int ret = 0; 674 675 mutex_lock(&group->group_lock); 676 if (!group->container) { 677 ret = -EINVAL; 678 goto out_unlock; 679 } 680 if (group->container_users != 1) { 681 ret = -EBUSY; 682 goto out_unlock; 683 } 684 vfio_group_detach_container(group); 685 686 out_unlock: 687 mutex_unlock(&group->group_lock); 688 return ret; 689 } 690 691 static int vfio_group_ioctl_set_container(struct vfio_group *group, 692 int __user *arg) 693 { 694 struct vfio_container *container; 695 struct fd f; 696 int ret; 697 int fd; 698 699 if (get_user(fd, arg)) 700 return -EFAULT; 701 702 f = fdget(fd); 703 if (!f.file) 704 return -EBADF; 705 706 mutex_lock(&group->group_lock); 707 if (group->container || WARN_ON(group->container_users)) { 708 ret = -EINVAL; 709 goto out_unlock; 710 } 711 if (!group->iommu_group) { 712 ret = -ENODEV; 713 goto out_unlock; 714 } 715 716 container = vfio_container_from_file(f.file); 717 ret = -EINVAL; 718 if (container) { 719 ret = vfio_container_attach_group(container, group); 720 goto out_unlock; 721 } 722 723 out_unlock: 724 mutex_unlock(&group->group_lock); 725 fdput(f); 726 return ret; 727 } 728 729 static const struct file_operations vfio_device_fops; 730 731 /* true if the vfio_device has open_device() called but not close_device() */ 732 bool vfio_assert_device_open(struct vfio_device *device) 733 { 734 return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); 735 } 736 737 static struct file *vfio_device_open(struct vfio_device *device) 738 { 739 struct file *filep; 740 int ret; 741 742 mutex_lock(&device->group->group_lock); 743 ret = vfio_device_assign_container(device); 744 mutex_unlock(&device->group->group_lock); 745 if (ret) 746 return ERR_PTR(ret); 747 748 if (!try_module_get(device->dev->driver->owner)) { 749 ret = -ENODEV; 750 goto err_unassign_container; 751 } 752 753 mutex_lock(&device->dev_set->lock); 754 device->open_count++; 755 if (device->open_count == 1) { 756 /* 757 * Here we pass the KVM pointer with the group under the read 758 * lock. If the device driver will use it, it must obtain a 759 * reference and release it during close_device. 760 */ 761 mutex_lock(&device->group->group_lock); 762 device->kvm = device->group->kvm; 763 764 if (device->ops->open_device) { 765 ret = device->ops->open_device(device); 766 if (ret) 767 goto err_undo_count; 768 } 769 vfio_device_container_register(device); 770 mutex_unlock(&device->group->group_lock); 771 } 772 mutex_unlock(&device->dev_set->lock); 773 774 /* 775 * We can't use anon_inode_getfd() because we need to modify 776 * the f_mode flags directly to allow more than just ioctls 777 */ 778 filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, 779 device, O_RDWR); 780 if (IS_ERR(filep)) { 781 ret = PTR_ERR(filep); 782 goto err_close_device; 783 } 784 785 /* 786 * TODO: add an anon_inode interface to do this. 787 * Appears to be missing by lack of need rather than 788 * explicitly prevented. Now there's need. 789 */ 790 filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE); 791 792 if (device->group->type == VFIO_NO_IOMMU) 793 dev_warn(device->dev, "vfio-noiommu device opened by user " 794 "(%s:%d)\n", current->comm, task_pid_nr(current)); 795 /* 796 * On success the ref of device is moved to the file and 797 * put in vfio_device_fops_release() 798 */ 799 return filep; 800 801 err_close_device: 802 mutex_lock(&device->dev_set->lock); 803 mutex_lock(&device->group->group_lock); 804 if (device->open_count == 1 && device->ops->close_device) { 805 device->ops->close_device(device); 806 807 vfio_device_container_unregister(device); 808 } 809 err_undo_count: 810 mutex_unlock(&device->group->group_lock); 811 device->open_count--; 812 if (device->open_count == 0 && device->kvm) 813 device->kvm = NULL; 814 mutex_unlock(&device->dev_set->lock); 815 module_put(device->dev->driver->owner); 816 err_unassign_container: 817 vfio_device_unassign_container(device); 818 return ERR_PTR(ret); 819 } 820 821 static int vfio_group_ioctl_get_device_fd(struct vfio_group *group, 822 char __user *arg) 823 { 824 struct vfio_device *device; 825 struct file *filep; 826 char *buf; 827 int fdno; 828 int ret; 829 830 buf = strndup_user(arg, PAGE_SIZE); 831 if (IS_ERR(buf)) 832 return PTR_ERR(buf); 833 834 device = vfio_device_get_from_name(group, buf); 835 kfree(buf); 836 if (IS_ERR(device)) 837 return PTR_ERR(device); 838 839 fdno = get_unused_fd_flags(O_CLOEXEC); 840 if (fdno < 0) { 841 ret = fdno; 842 goto err_put_device; 843 } 844 845 filep = vfio_device_open(device); 846 if (IS_ERR(filep)) { 847 ret = PTR_ERR(filep); 848 goto err_put_fdno; 849 } 850 851 fd_install(fdno, filep); 852 return fdno; 853 854 err_put_fdno: 855 put_unused_fd(fdno); 856 err_put_device: 857 vfio_device_put_registration(device); 858 return ret; 859 } 860 861 static int vfio_group_ioctl_get_status(struct vfio_group *group, 862 struct vfio_group_status __user *arg) 863 { 864 unsigned long minsz = offsetofend(struct vfio_group_status, flags); 865 struct vfio_group_status status; 866 867 if (copy_from_user(&status, arg, minsz)) 868 return -EFAULT; 869 870 if (status.argsz < minsz) 871 return -EINVAL; 872 873 status.flags = 0; 874 875 mutex_lock(&group->group_lock); 876 if (!group->iommu_group) { 877 mutex_unlock(&group->group_lock); 878 return -ENODEV; 879 } 880 881 if (group->container) 882 status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET | 883 VFIO_GROUP_FLAGS_VIABLE; 884 else if (!iommu_group_dma_owner_claimed(group->iommu_group)) 885 status.flags |= VFIO_GROUP_FLAGS_VIABLE; 886 mutex_unlock(&group->group_lock); 887 888 if (copy_to_user(arg, &status, minsz)) 889 return -EFAULT; 890 return 0; 891 } 892 893 static long vfio_group_fops_unl_ioctl(struct file *filep, 894 unsigned int cmd, unsigned long arg) 895 { 896 struct vfio_group *group = filep->private_data; 897 void __user *uarg = (void __user *)arg; 898 899 switch (cmd) { 900 case VFIO_GROUP_GET_DEVICE_FD: 901 return vfio_group_ioctl_get_device_fd(group, uarg); 902 case VFIO_GROUP_GET_STATUS: 903 return vfio_group_ioctl_get_status(group, uarg); 904 case VFIO_GROUP_SET_CONTAINER: 905 return vfio_group_ioctl_set_container(group, uarg); 906 case VFIO_GROUP_UNSET_CONTAINER: 907 return vfio_group_ioctl_unset_container(group); 908 default: 909 return -ENOTTY; 910 } 911 } 912 913 static int vfio_group_fops_open(struct inode *inode, struct file *filep) 914 { 915 struct vfio_group *group = 916 container_of(inode->i_cdev, struct vfio_group, cdev); 917 int ret; 918 919 mutex_lock(&group->group_lock); 920 921 /* 922 * drivers can be zero if this races with vfio_device_remove_group(), it 923 * will be stable at 0 under the group rwsem 924 */ 925 if (refcount_read(&group->drivers) == 0) { 926 ret = -ENODEV; 927 goto out_unlock; 928 } 929 930 if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) { 931 ret = -EPERM; 932 goto out_unlock; 933 } 934 935 /* 936 * Do we need multiple instances of the group open? Seems not. 937 */ 938 if (group->opened_file) { 939 ret = -EBUSY; 940 goto out_unlock; 941 } 942 group->opened_file = filep; 943 filep->private_data = group; 944 ret = 0; 945 out_unlock: 946 mutex_unlock(&group->group_lock); 947 return ret; 948 } 949 950 static int vfio_group_fops_release(struct inode *inode, struct file *filep) 951 { 952 struct vfio_group *group = filep->private_data; 953 954 filep->private_data = NULL; 955 956 mutex_lock(&group->group_lock); 957 /* 958 * Device FDs hold a group file reference, therefore the group release 959 * is only called when there are no open devices. 960 */ 961 WARN_ON(group->notifier.head); 962 if (group->container) 963 vfio_group_detach_container(group); 964 group->opened_file = NULL; 965 mutex_unlock(&group->group_lock); 966 return 0; 967 } 968 969 static const struct file_operations vfio_group_fops = { 970 .owner = THIS_MODULE, 971 .unlocked_ioctl = vfio_group_fops_unl_ioctl, 972 .compat_ioctl = compat_ptr_ioctl, 973 .open = vfio_group_fops_open, 974 .release = vfio_group_fops_release, 975 }; 976 977 /* 978 * Wrapper around pm_runtime_resume_and_get(). 979 * Return error code on failure or 0 on success. 980 */ 981 static inline int vfio_device_pm_runtime_get(struct vfio_device *device) 982 { 983 struct device *dev = device->dev; 984 985 if (dev->driver && dev->driver->pm) { 986 int ret; 987 988 ret = pm_runtime_resume_and_get(dev); 989 if (ret) { 990 dev_info_ratelimited(dev, 991 "vfio: runtime resume failed %d\n", ret); 992 return -EIO; 993 } 994 } 995 996 return 0; 997 } 998 999 /* 1000 * Wrapper around pm_runtime_put(). 1001 */ 1002 static inline void vfio_device_pm_runtime_put(struct vfio_device *device) 1003 { 1004 struct device *dev = device->dev; 1005 1006 if (dev->driver && dev->driver->pm) 1007 pm_runtime_put(dev); 1008 } 1009 1010 /* 1011 * VFIO Device fd 1012 */ 1013 static int vfio_device_fops_release(struct inode *inode, struct file *filep) 1014 { 1015 struct vfio_device *device = filep->private_data; 1016 1017 mutex_lock(&device->dev_set->lock); 1018 vfio_assert_device_open(device); 1019 mutex_lock(&device->group->group_lock); 1020 if (device->open_count == 1 && device->ops->close_device) 1021 device->ops->close_device(device); 1022 1023 vfio_device_container_unregister(device); 1024 mutex_unlock(&device->group->group_lock); 1025 device->open_count--; 1026 if (device->open_count == 0) 1027 device->kvm = NULL; 1028 mutex_unlock(&device->dev_set->lock); 1029 1030 module_put(device->dev->driver->owner); 1031 1032 vfio_device_unassign_container(device); 1033 1034 vfio_device_put_registration(device); 1035 1036 return 0; 1037 } 1038 1039 /* 1040 * vfio_mig_get_next_state - Compute the next step in the FSM 1041 * @cur_fsm - The current state the device is in 1042 * @new_fsm - The target state to reach 1043 * @next_fsm - Pointer to the next step to get to new_fsm 1044 * 1045 * Return 0 upon success, otherwise -errno 1046 * Upon success the next step in the state progression between cur_fsm and 1047 * new_fsm will be set in next_fsm. 1048 * 1049 * This breaks down requests for combination transitions into smaller steps and 1050 * returns the next step to get to new_fsm. The function may need to be called 1051 * multiple times before reaching new_fsm. 1052 * 1053 */ 1054 int vfio_mig_get_next_state(struct vfio_device *device, 1055 enum vfio_device_mig_state cur_fsm, 1056 enum vfio_device_mig_state new_fsm, 1057 enum vfio_device_mig_state *next_fsm) 1058 { 1059 enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_RUNNING_P2P + 1 }; 1060 /* 1061 * The coding in this table requires the driver to implement the 1062 * following FSM arcs: 1063 * RESUMING -> STOP 1064 * STOP -> RESUMING 1065 * STOP -> STOP_COPY 1066 * STOP_COPY -> STOP 1067 * 1068 * If P2P is supported then the driver must also implement these FSM 1069 * arcs: 1070 * RUNNING -> RUNNING_P2P 1071 * RUNNING_P2P -> RUNNING 1072 * RUNNING_P2P -> STOP 1073 * STOP -> RUNNING_P2P 1074 * Without P2P the driver must implement: 1075 * RUNNING -> STOP 1076 * STOP -> RUNNING 1077 * 1078 * The coding will step through multiple states for some combination 1079 * transitions; if all optional features are supported, this means the 1080 * following ones: 1081 * RESUMING -> STOP -> RUNNING_P2P 1082 * RESUMING -> STOP -> RUNNING_P2P -> RUNNING 1083 * RESUMING -> STOP -> STOP_COPY 1084 * RUNNING -> RUNNING_P2P -> STOP 1085 * RUNNING -> RUNNING_P2P -> STOP -> RESUMING 1086 * RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY 1087 * RUNNING_P2P -> STOP -> RESUMING 1088 * RUNNING_P2P -> STOP -> STOP_COPY 1089 * STOP -> RUNNING_P2P -> RUNNING 1090 * STOP_COPY -> STOP -> RESUMING 1091 * STOP_COPY -> STOP -> RUNNING_P2P 1092 * STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING 1093 */ 1094 static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = { 1095 [VFIO_DEVICE_STATE_STOP] = { 1096 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1097 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P, 1098 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, 1099 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING, 1100 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, 1101 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1102 }, 1103 [VFIO_DEVICE_STATE_RUNNING] = { 1104 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P, 1105 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING, 1106 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P, 1107 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P, 1108 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, 1109 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1110 }, 1111 [VFIO_DEVICE_STATE_STOP_COPY] = { 1112 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1113 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP, 1114 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, 1115 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP, 1116 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP, 1117 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1118 }, 1119 [VFIO_DEVICE_STATE_RESUMING] = { 1120 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1121 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP, 1122 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, 1123 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING, 1124 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP, 1125 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1126 }, 1127 [VFIO_DEVICE_STATE_RUNNING_P2P] = { 1128 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1129 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING, 1130 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, 1131 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP, 1132 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, 1133 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1134 }, 1135 [VFIO_DEVICE_STATE_ERROR] = { 1136 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR, 1137 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR, 1138 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR, 1139 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR, 1140 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR, 1141 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1142 }, 1143 }; 1144 1145 static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = { 1146 [VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY, 1147 [VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY, 1148 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY, 1149 [VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY, 1150 [VFIO_DEVICE_STATE_RUNNING_P2P] = 1151 VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P, 1152 [VFIO_DEVICE_STATE_ERROR] = ~0U, 1153 }; 1154 1155 if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) || 1156 (state_flags_table[cur_fsm] & device->migration_flags) != 1157 state_flags_table[cur_fsm])) 1158 return -EINVAL; 1159 1160 if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) || 1161 (state_flags_table[new_fsm] & device->migration_flags) != 1162 state_flags_table[new_fsm]) 1163 return -EINVAL; 1164 1165 /* 1166 * Arcs touching optional and unsupported states are skipped over. The 1167 * driver will instead see an arc from the original state to the next 1168 * logical state, as per the above comment. 1169 */ 1170 *next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm]; 1171 while ((state_flags_table[*next_fsm] & device->migration_flags) != 1172 state_flags_table[*next_fsm]) 1173 *next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm]; 1174 1175 return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL; 1176 } 1177 EXPORT_SYMBOL_GPL(vfio_mig_get_next_state); 1178 1179 /* 1180 * Convert the drivers's struct file into a FD number and return it to userspace 1181 */ 1182 static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg, 1183 struct vfio_device_feature_mig_state *mig) 1184 { 1185 int ret; 1186 int fd; 1187 1188 fd = get_unused_fd_flags(O_CLOEXEC); 1189 if (fd < 0) { 1190 ret = fd; 1191 goto out_fput; 1192 } 1193 1194 mig->data_fd = fd; 1195 if (copy_to_user(arg, mig, sizeof(*mig))) { 1196 ret = -EFAULT; 1197 goto out_put_unused; 1198 } 1199 fd_install(fd, filp); 1200 return 0; 1201 1202 out_put_unused: 1203 put_unused_fd(fd); 1204 out_fput: 1205 fput(filp); 1206 return ret; 1207 } 1208 1209 static int 1210 vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device, 1211 u32 flags, void __user *arg, 1212 size_t argsz) 1213 { 1214 size_t minsz = 1215 offsetofend(struct vfio_device_feature_mig_state, data_fd); 1216 struct vfio_device_feature_mig_state mig; 1217 struct file *filp = NULL; 1218 int ret; 1219 1220 if (!device->mig_ops) 1221 return -ENOTTY; 1222 1223 ret = vfio_check_feature(flags, argsz, 1224 VFIO_DEVICE_FEATURE_SET | 1225 VFIO_DEVICE_FEATURE_GET, 1226 sizeof(mig)); 1227 if (ret != 1) 1228 return ret; 1229 1230 if (copy_from_user(&mig, arg, minsz)) 1231 return -EFAULT; 1232 1233 if (flags & VFIO_DEVICE_FEATURE_GET) { 1234 enum vfio_device_mig_state curr_state; 1235 1236 ret = device->mig_ops->migration_get_state(device, 1237 &curr_state); 1238 if (ret) 1239 return ret; 1240 mig.device_state = curr_state; 1241 goto out_copy; 1242 } 1243 1244 /* Handle the VFIO_DEVICE_FEATURE_SET */ 1245 filp = device->mig_ops->migration_set_state(device, mig.device_state); 1246 if (IS_ERR(filp) || !filp) 1247 goto out_copy; 1248 1249 return vfio_ioct_mig_return_fd(filp, arg, &mig); 1250 out_copy: 1251 mig.data_fd = -1; 1252 if (copy_to_user(arg, &mig, sizeof(mig))) 1253 return -EFAULT; 1254 if (IS_ERR(filp)) 1255 return PTR_ERR(filp); 1256 return 0; 1257 } 1258 1259 static int vfio_ioctl_device_feature_migration(struct vfio_device *device, 1260 u32 flags, void __user *arg, 1261 size_t argsz) 1262 { 1263 struct vfio_device_feature_migration mig = { 1264 .flags = device->migration_flags, 1265 }; 1266 int ret; 1267 1268 if (!device->mig_ops) 1269 return -ENOTTY; 1270 1271 ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET, 1272 sizeof(mig)); 1273 if (ret != 1) 1274 return ret; 1275 if (copy_to_user(arg, &mig, sizeof(mig))) 1276 return -EFAULT; 1277 return 0; 1278 } 1279 1280 /* Ranges should fit into a single kernel page */ 1281 #define LOG_MAX_RANGES \ 1282 (PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range)) 1283 1284 static int 1285 vfio_ioctl_device_feature_logging_start(struct vfio_device *device, 1286 u32 flags, void __user *arg, 1287 size_t argsz) 1288 { 1289 size_t minsz = 1290 offsetofend(struct vfio_device_feature_dma_logging_control, 1291 ranges); 1292 struct vfio_device_feature_dma_logging_range __user *ranges; 1293 struct vfio_device_feature_dma_logging_control control; 1294 struct vfio_device_feature_dma_logging_range range; 1295 struct rb_root_cached root = RB_ROOT_CACHED; 1296 struct interval_tree_node *nodes; 1297 u64 iova_end; 1298 u32 nnodes; 1299 int i, ret; 1300 1301 if (!device->log_ops) 1302 return -ENOTTY; 1303 1304 ret = vfio_check_feature(flags, argsz, 1305 VFIO_DEVICE_FEATURE_SET, 1306 sizeof(control)); 1307 if (ret != 1) 1308 return ret; 1309 1310 if (copy_from_user(&control, arg, minsz)) 1311 return -EFAULT; 1312 1313 nnodes = control.num_ranges; 1314 if (!nnodes) 1315 return -EINVAL; 1316 1317 if (nnodes > LOG_MAX_RANGES) 1318 return -E2BIG; 1319 1320 ranges = u64_to_user_ptr(control.ranges); 1321 nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node), 1322 GFP_KERNEL); 1323 if (!nodes) 1324 return -ENOMEM; 1325 1326 for (i = 0; i < nnodes; i++) { 1327 if (copy_from_user(&range, &ranges[i], sizeof(range))) { 1328 ret = -EFAULT; 1329 goto end; 1330 } 1331 if (!IS_ALIGNED(range.iova, control.page_size) || 1332 !IS_ALIGNED(range.length, control.page_size)) { 1333 ret = -EINVAL; 1334 goto end; 1335 } 1336 1337 if (check_add_overflow(range.iova, range.length, &iova_end) || 1338 iova_end > ULONG_MAX) { 1339 ret = -EOVERFLOW; 1340 goto end; 1341 } 1342 1343 nodes[i].start = range.iova; 1344 nodes[i].last = range.iova + range.length - 1; 1345 if (interval_tree_iter_first(&root, nodes[i].start, 1346 nodes[i].last)) { 1347 /* Range overlapping */ 1348 ret = -EINVAL; 1349 goto end; 1350 } 1351 interval_tree_insert(nodes + i, &root); 1352 } 1353 1354 ret = device->log_ops->log_start(device, &root, nnodes, 1355 &control.page_size); 1356 if (ret) 1357 goto end; 1358 1359 if (copy_to_user(arg, &control, sizeof(control))) { 1360 ret = -EFAULT; 1361 device->log_ops->log_stop(device); 1362 } 1363 1364 end: 1365 kfree(nodes); 1366 return ret; 1367 } 1368 1369 static int 1370 vfio_ioctl_device_feature_logging_stop(struct vfio_device *device, 1371 u32 flags, void __user *arg, 1372 size_t argsz) 1373 { 1374 int ret; 1375 1376 if (!device->log_ops) 1377 return -ENOTTY; 1378 1379 ret = vfio_check_feature(flags, argsz, 1380 VFIO_DEVICE_FEATURE_SET, 0); 1381 if (ret != 1) 1382 return ret; 1383 1384 return device->log_ops->log_stop(device); 1385 } 1386 1387 static int vfio_device_log_read_and_clear(struct iova_bitmap *iter, 1388 unsigned long iova, size_t length, 1389 void *opaque) 1390 { 1391 struct vfio_device *device = opaque; 1392 1393 return device->log_ops->log_read_and_clear(device, iova, length, iter); 1394 } 1395 1396 static int 1397 vfio_ioctl_device_feature_logging_report(struct vfio_device *device, 1398 u32 flags, void __user *arg, 1399 size_t argsz) 1400 { 1401 size_t minsz = 1402 offsetofend(struct vfio_device_feature_dma_logging_report, 1403 bitmap); 1404 struct vfio_device_feature_dma_logging_report report; 1405 struct iova_bitmap *iter; 1406 u64 iova_end; 1407 int ret; 1408 1409 if (!device->log_ops) 1410 return -ENOTTY; 1411 1412 ret = vfio_check_feature(flags, argsz, 1413 VFIO_DEVICE_FEATURE_GET, 1414 sizeof(report)); 1415 if (ret != 1) 1416 return ret; 1417 1418 if (copy_from_user(&report, arg, minsz)) 1419 return -EFAULT; 1420 1421 if (report.page_size < SZ_4K || !is_power_of_2(report.page_size)) 1422 return -EINVAL; 1423 1424 if (check_add_overflow(report.iova, report.length, &iova_end) || 1425 iova_end > ULONG_MAX) 1426 return -EOVERFLOW; 1427 1428 iter = iova_bitmap_alloc(report.iova, report.length, 1429 report.page_size, 1430 u64_to_user_ptr(report.bitmap)); 1431 if (IS_ERR(iter)) 1432 return PTR_ERR(iter); 1433 1434 ret = iova_bitmap_for_each(iter, device, 1435 vfio_device_log_read_and_clear); 1436 1437 iova_bitmap_free(iter); 1438 return ret; 1439 } 1440 1441 static int vfio_ioctl_device_feature(struct vfio_device *device, 1442 struct vfio_device_feature __user *arg) 1443 { 1444 size_t minsz = offsetofend(struct vfio_device_feature, flags); 1445 struct vfio_device_feature feature; 1446 1447 if (copy_from_user(&feature, arg, minsz)) 1448 return -EFAULT; 1449 1450 if (feature.argsz < minsz) 1451 return -EINVAL; 1452 1453 /* Check unknown flags */ 1454 if (feature.flags & 1455 ~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET | 1456 VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE)) 1457 return -EINVAL; 1458 1459 /* GET & SET are mutually exclusive except with PROBE */ 1460 if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) && 1461 (feature.flags & VFIO_DEVICE_FEATURE_SET) && 1462 (feature.flags & VFIO_DEVICE_FEATURE_GET)) 1463 return -EINVAL; 1464 1465 switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) { 1466 case VFIO_DEVICE_FEATURE_MIGRATION: 1467 return vfio_ioctl_device_feature_migration( 1468 device, feature.flags, arg->data, 1469 feature.argsz - minsz); 1470 case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE: 1471 return vfio_ioctl_device_feature_mig_device_state( 1472 device, feature.flags, arg->data, 1473 feature.argsz - minsz); 1474 case VFIO_DEVICE_FEATURE_DMA_LOGGING_START: 1475 return vfio_ioctl_device_feature_logging_start( 1476 device, feature.flags, arg->data, 1477 feature.argsz - minsz); 1478 case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP: 1479 return vfio_ioctl_device_feature_logging_stop( 1480 device, feature.flags, arg->data, 1481 feature.argsz - minsz); 1482 case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT: 1483 return vfio_ioctl_device_feature_logging_report( 1484 device, feature.flags, arg->data, 1485 feature.argsz - minsz); 1486 default: 1487 if (unlikely(!device->ops->device_feature)) 1488 return -EINVAL; 1489 return device->ops->device_feature(device, feature.flags, 1490 arg->data, 1491 feature.argsz - minsz); 1492 } 1493 } 1494 1495 static long vfio_device_fops_unl_ioctl(struct file *filep, 1496 unsigned int cmd, unsigned long arg) 1497 { 1498 struct vfio_device *device = filep->private_data; 1499 int ret; 1500 1501 ret = vfio_device_pm_runtime_get(device); 1502 if (ret) 1503 return ret; 1504 1505 switch (cmd) { 1506 case VFIO_DEVICE_FEATURE: 1507 ret = vfio_ioctl_device_feature(device, (void __user *)arg); 1508 break; 1509 1510 default: 1511 if (unlikely(!device->ops->ioctl)) 1512 ret = -EINVAL; 1513 else 1514 ret = device->ops->ioctl(device, cmd, arg); 1515 break; 1516 } 1517 1518 vfio_device_pm_runtime_put(device); 1519 return ret; 1520 } 1521 1522 static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf, 1523 size_t count, loff_t *ppos) 1524 { 1525 struct vfio_device *device = filep->private_data; 1526 1527 if (unlikely(!device->ops->read)) 1528 return -EINVAL; 1529 1530 return device->ops->read(device, buf, count, ppos); 1531 } 1532 1533 static ssize_t vfio_device_fops_write(struct file *filep, 1534 const char __user *buf, 1535 size_t count, loff_t *ppos) 1536 { 1537 struct vfio_device *device = filep->private_data; 1538 1539 if (unlikely(!device->ops->write)) 1540 return -EINVAL; 1541 1542 return device->ops->write(device, buf, count, ppos); 1543 } 1544 1545 static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma) 1546 { 1547 struct vfio_device *device = filep->private_data; 1548 1549 if (unlikely(!device->ops->mmap)) 1550 return -EINVAL; 1551 1552 return device->ops->mmap(device, vma); 1553 } 1554 1555 static const struct file_operations vfio_device_fops = { 1556 .owner = THIS_MODULE, 1557 .release = vfio_device_fops_release, 1558 .read = vfio_device_fops_read, 1559 .write = vfio_device_fops_write, 1560 .unlocked_ioctl = vfio_device_fops_unl_ioctl, 1561 .compat_ioctl = compat_ptr_ioctl, 1562 .mmap = vfio_device_fops_mmap, 1563 }; 1564 1565 /** 1566 * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file 1567 * @file: VFIO group file 1568 * 1569 * The returned iommu_group is valid as long as a ref is held on the file. This 1570 * returns a reference on the group. This function is deprecated, only the SPAPR 1571 * path in kvm should call it. 1572 */ 1573 struct iommu_group *vfio_file_iommu_group(struct file *file) 1574 { 1575 struct vfio_group *group = file->private_data; 1576 struct iommu_group *iommu_group = NULL; 1577 1578 if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU)) 1579 return NULL; 1580 1581 if (!vfio_file_is_group(file)) 1582 return NULL; 1583 1584 mutex_lock(&group->group_lock); 1585 if (group->iommu_group) { 1586 iommu_group = group->iommu_group; 1587 iommu_group_ref_get(iommu_group); 1588 } 1589 mutex_unlock(&group->group_lock); 1590 return iommu_group; 1591 } 1592 EXPORT_SYMBOL_GPL(vfio_file_iommu_group); 1593 1594 /** 1595 * vfio_file_is_group - True if the file is usable with VFIO aPIS 1596 * @file: VFIO group file 1597 */ 1598 bool vfio_file_is_group(struct file *file) 1599 { 1600 return file->f_op == &vfio_group_fops; 1601 } 1602 EXPORT_SYMBOL_GPL(vfio_file_is_group); 1603 1604 /** 1605 * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file 1606 * is always CPU cache coherent 1607 * @file: VFIO group file 1608 * 1609 * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop 1610 * bit in DMA transactions. A return of false indicates that the user has 1611 * rights to access additional instructions such as wbinvd on x86. 1612 */ 1613 bool vfio_file_enforced_coherent(struct file *file) 1614 { 1615 struct vfio_group *group = file->private_data; 1616 bool ret; 1617 1618 if (!vfio_file_is_group(file)) 1619 return true; 1620 1621 mutex_lock(&group->group_lock); 1622 if (group->container) { 1623 ret = vfio_container_ioctl_check_extension(group->container, 1624 VFIO_DMA_CC_IOMMU); 1625 } else { 1626 /* 1627 * Since the coherency state is determined only once a container 1628 * is attached the user must do so before they can prove they 1629 * have permission. 1630 */ 1631 ret = true; 1632 } 1633 mutex_unlock(&group->group_lock); 1634 return ret; 1635 } 1636 EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); 1637 1638 /** 1639 * vfio_file_set_kvm - Link a kvm with VFIO drivers 1640 * @file: VFIO group file 1641 * @kvm: KVM to link 1642 * 1643 * When a VFIO device is first opened the KVM will be available in 1644 * device->kvm if one was associated with the group. 1645 */ 1646 void vfio_file_set_kvm(struct file *file, struct kvm *kvm) 1647 { 1648 struct vfio_group *group = file->private_data; 1649 1650 if (!vfio_file_is_group(file)) 1651 return; 1652 1653 mutex_lock(&group->group_lock); 1654 group->kvm = kvm; 1655 mutex_unlock(&group->group_lock); 1656 } 1657 EXPORT_SYMBOL_GPL(vfio_file_set_kvm); 1658 1659 /** 1660 * vfio_file_has_dev - True if the VFIO file is a handle for device 1661 * @file: VFIO file to check 1662 * @device: Device that must be part of the file 1663 * 1664 * Returns true if given file has permission to manipulate the given device. 1665 */ 1666 bool vfio_file_has_dev(struct file *file, struct vfio_device *device) 1667 { 1668 struct vfio_group *group = file->private_data; 1669 1670 if (!vfio_file_is_group(file)) 1671 return false; 1672 1673 return group == device->group; 1674 } 1675 EXPORT_SYMBOL_GPL(vfio_file_has_dev); 1676 1677 /* 1678 * Sub-module support 1679 */ 1680 /* 1681 * Helper for managing a buffer of info chain capabilities, allocate or 1682 * reallocate a buffer with additional @size, filling in @id and @version 1683 * of the capability. A pointer to the new capability is returned. 1684 * 1685 * NB. The chain is based at the head of the buffer, so new entries are 1686 * added to the tail, vfio_info_cap_shift() should be called to fixup the 1687 * next offsets prior to copying to the user buffer. 1688 */ 1689 struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, 1690 size_t size, u16 id, u16 version) 1691 { 1692 void *buf; 1693 struct vfio_info_cap_header *header, *tmp; 1694 1695 buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL); 1696 if (!buf) { 1697 kfree(caps->buf); 1698 caps->buf = NULL; 1699 caps->size = 0; 1700 return ERR_PTR(-ENOMEM); 1701 } 1702 1703 caps->buf = buf; 1704 header = buf + caps->size; 1705 1706 /* Eventually copied to user buffer, zero */ 1707 memset(header, 0, size); 1708 1709 header->id = id; 1710 header->version = version; 1711 1712 /* Add to the end of the capability chain */ 1713 for (tmp = buf; tmp->next; tmp = buf + tmp->next) 1714 ; /* nothing */ 1715 1716 tmp->next = caps->size; 1717 caps->size += size; 1718 1719 return header; 1720 } 1721 EXPORT_SYMBOL_GPL(vfio_info_cap_add); 1722 1723 void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset) 1724 { 1725 struct vfio_info_cap_header *tmp; 1726 void *buf = (void *)caps->buf; 1727 1728 for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset) 1729 tmp->next += offset; 1730 } 1731 EXPORT_SYMBOL(vfio_info_cap_shift); 1732 1733 int vfio_info_add_capability(struct vfio_info_cap *caps, 1734 struct vfio_info_cap_header *cap, size_t size) 1735 { 1736 struct vfio_info_cap_header *header; 1737 1738 header = vfio_info_cap_add(caps, size, cap->id, cap->version); 1739 if (IS_ERR(header)) 1740 return PTR_ERR(header); 1741 1742 memcpy(header + 1, cap + 1, size - sizeof(*header)); 1743 1744 return 0; 1745 } 1746 EXPORT_SYMBOL(vfio_info_add_capability); 1747 1748 int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs, 1749 int max_irq_type, size_t *data_size) 1750 { 1751 unsigned long minsz; 1752 size_t size; 1753 1754 minsz = offsetofend(struct vfio_irq_set, count); 1755 1756 if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) || 1757 (hdr->count >= (U32_MAX - hdr->start)) || 1758 (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK | 1759 VFIO_IRQ_SET_ACTION_TYPE_MASK))) 1760 return -EINVAL; 1761 1762 if (data_size) 1763 *data_size = 0; 1764 1765 if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs) 1766 return -EINVAL; 1767 1768 switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) { 1769 case VFIO_IRQ_SET_DATA_NONE: 1770 size = 0; 1771 break; 1772 case VFIO_IRQ_SET_DATA_BOOL: 1773 size = sizeof(uint8_t); 1774 break; 1775 case VFIO_IRQ_SET_DATA_EVENTFD: 1776 size = sizeof(int32_t); 1777 break; 1778 default: 1779 return -EINVAL; 1780 } 1781 1782 if (size) { 1783 if (hdr->argsz - minsz < hdr->count * size) 1784 return -EINVAL; 1785 1786 if (!data_size) 1787 return -EINVAL; 1788 1789 *data_size = hdr->count * size; 1790 } 1791 1792 return 0; 1793 } 1794 EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); 1795 1796 /* 1797 * Module/class support 1798 */ 1799 static char *vfio_devnode(struct device *dev, umode_t *mode) 1800 { 1801 return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); 1802 } 1803 1804 static int __init vfio_init(void) 1805 { 1806 int ret; 1807 1808 ida_init(&vfio.group_ida); 1809 ida_init(&vfio.device_ida); 1810 mutex_init(&vfio.group_lock); 1811 INIT_LIST_HEAD(&vfio.group_list); 1812 1813 ret = vfio_container_init(); 1814 if (ret) 1815 return ret; 1816 1817 /* /dev/vfio/$GROUP */ 1818 vfio.class = class_create(THIS_MODULE, "vfio"); 1819 if (IS_ERR(vfio.class)) { 1820 ret = PTR_ERR(vfio.class); 1821 goto err_group_class; 1822 } 1823 1824 vfio.class->devnode = vfio_devnode; 1825 1826 /* /sys/class/vfio-dev/vfioX */ 1827 vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); 1828 if (IS_ERR(vfio.device_class)) { 1829 ret = PTR_ERR(vfio.device_class); 1830 goto err_dev_class; 1831 } 1832 1833 ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); 1834 if (ret) 1835 goto err_alloc_chrdev; 1836 1837 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); 1838 return 0; 1839 1840 err_alloc_chrdev: 1841 class_destroy(vfio.device_class); 1842 vfio.device_class = NULL; 1843 err_dev_class: 1844 class_destroy(vfio.class); 1845 vfio.class = NULL; 1846 err_group_class: 1847 vfio_container_cleanup(); 1848 return ret; 1849 } 1850 1851 static void __exit vfio_cleanup(void) 1852 { 1853 WARN_ON(!list_empty(&vfio.group_list)); 1854 1855 ida_destroy(&vfio.device_ida); 1856 ida_destroy(&vfio.group_ida); 1857 unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); 1858 class_destroy(vfio.device_class); 1859 vfio.device_class = NULL; 1860 class_destroy(vfio.class); 1861 vfio_container_cleanup(); 1862 vfio.class = NULL; 1863 xa_destroy(&vfio_device_set_xa); 1864 } 1865 1866 module_init(vfio_init); 1867 module_exit(vfio_cleanup); 1868 1869 MODULE_VERSION(DRIVER_VERSION); 1870 MODULE_LICENSE("GPL v2"); 1871 MODULE_AUTHOR(DRIVER_AUTHOR); 1872 MODULE_DESCRIPTION(DRIVER_DESC); 1873 MODULE_ALIAS_MISCDEV(VFIO_MINOR); 1874 MODULE_ALIAS("devname:vfio/vfio"); 1875 MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce"); 1876