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 unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set) 129 { 130 struct vfio_device *cur; 131 unsigned int open_count = 0; 132 133 lockdep_assert_held(&dev_set->lock); 134 135 list_for_each_entry(cur, &dev_set->device_list, dev_set_list) 136 open_count += cur->open_count; 137 return open_count; 138 } 139 EXPORT_SYMBOL_GPL(vfio_device_set_open_count); 140 141 /* 142 * Group objects - create, release, get, put, search 143 */ 144 static struct vfio_group * 145 __vfio_group_get_from_iommu(struct iommu_group *iommu_group) 146 { 147 struct vfio_group *group; 148 149 /* 150 * group->iommu_group from the vfio.group_list cannot be NULL 151 * under the vfio.group_lock. 152 */ 153 list_for_each_entry(group, &vfio.group_list, vfio_next) { 154 if (group->iommu_group == iommu_group) { 155 refcount_inc(&group->drivers); 156 return group; 157 } 158 } 159 return NULL; 160 } 161 162 static struct vfio_group * 163 vfio_group_get_from_iommu(struct iommu_group *iommu_group) 164 { 165 struct vfio_group *group; 166 167 mutex_lock(&vfio.group_lock); 168 group = __vfio_group_get_from_iommu(iommu_group); 169 mutex_unlock(&vfio.group_lock); 170 return group; 171 } 172 173 static void vfio_group_release(struct device *dev) 174 { 175 struct vfio_group *group = container_of(dev, struct vfio_group, dev); 176 177 mutex_destroy(&group->device_lock); 178 mutex_destroy(&group->group_lock); 179 WARN_ON(group->iommu_group); 180 ida_free(&vfio.group_ida, MINOR(group->dev.devt)); 181 kfree(group); 182 } 183 184 static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, 185 enum vfio_group_type type) 186 { 187 struct vfio_group *group; 188 int minor; 189 190 group = kzalloc(sizeof(*group), GFP_KERNEL); 191 if (!group) 192 return ERR_PTR(-ENOMEM); 193 194 minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL); 195 if (minor < 0) { 196 kfree(group); 197 return ERR_PTR(minor); 198 } 199 200 device_initialize(&group->dev); 201 group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor); 202 group->dev.class = vfio.class; 203 group->dev.release = vfio_group_release; 204 cdev_init(&group->cdev, &vfio_group_fops); 205 group->cdev.owner = THIS_MODULE; 206 207 refcount_set(&group->drivers, 1); 208 mutex_init(&group->group_lock); 209 INIT_LIST_HEAD(&group->device_list); 210 mutex_init(&group->device_lock); 211 group->iommu_group = iommu_group; 212 /* put in vfio_group_release() */ 213 iommu_group_ref_get(iommu_group); 214 group->type = type; 215 BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier); 216 217 return group; 218 } 219 220 static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, 221 enum vfio_group_type type) 222 { 223 struct vfio_group *group; 224 struct vfio_group *ret; 225 int err; 226 227 group = vfio_group_alloc(iommu_group, type); 228 if (IS_ERR(group)) 229 return group; 230 231 err = dev_set_name(&group->dev, "%s%d", 232 group->type == VFIO_NO_IOMMU ? "noiommu-" : "", 233 iommu_group_id(iommu_group)); 234 if (err) { 235 ret = ERR_PTR(err); 236 goto err_put; 237 } 238 239 mutex_lock(&vfio.group_lock); 240 241 /* Did we race creating this group? */ 242 ret = __vfio_group_get_from_iommu(iommu_group); 243 if (ret) 244 goto err_unlock; 245 246 err = cdev_device_add(&group->cdev, &group->dev); 247 if (err) { 248 ret = ERR_PTR(err); 249 goto err_unlock; 250 } 251 252 list_add(&group->vfio_next, &vfio.group_list); 253 254 mutex_unlock(&vfio.group_lock); 255 return group; 256 257 err_unlock: 258 mutex_unlock(&vfio.group_lock); 259 err_put: 260 put_device(&group->dev); 261 return ret; 262 } 263 264 static void vfio_device_remove_group(struct vfio_device *device) 265 { 266 struct vfio_group *group = device->group; 267 struct iommu_group *iommu_group; 268 269 if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) 270 iommu_group_remove_device(device->dev); 271 272 /* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */ 273 if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock)) 274 return; 275 list_del(&group->vfio_next); 276 277 /* 278 * We could concurrently probe another driver in the group that might 279 * race vfio_device_remove_group() with vfio_get_group(), so we have to 280 * ensure that the sysfs is all cleaned up under lock otherwise the 281 * cdev_device_add() will fail due to the name aready existing. 282 */ 283 cdev_device_del(&group->cdev, &group->dev); 284 285 mutex_lock(&group->group_lock); 286 /* 287 * These data structures all have paired operations that can only be 288 * undone when the caller holds a live reference on the device. Since 289 * all pairs must be undone these WARN_ON's indicate some caller did not 290 * properly hold the group reference. 291 */ 292 WARN_ON(!list_empty(&group->device_list)); 293 WARN_ON(group->notifier.head); 294 295 /* 296 * Revoke all users of group->iommu_group. At this point we know there 297 * are no devices active because we are unplugging the last one. Setting 298 * iommu_group to NULL blocks all new users. 299 */ 300 if (group->container) 301 vfio_group_detach_container(group); 302 iommu_group = group->iommu_group; 303 group->iommu_group = NULL; 304 mutex_unlock(&group->group_lock); 305 mutex_unlock(&vfio.group_lock); 306 307 iommu_group_put(iommu_group); 308 put_device(&group->dev); 309 } 310 311 /* 312 * Device objects - create, release, get, put, search 313 */ 314 /* Device reference always implies a group reference */ 315 static void vfio_device_put_registration(struct vfio_device *device) 316 { 317 if (refcount_dec_and_test(&device->refcount)) 318 complete(&device->comp); 319 } 320 321 static bool vfio_device_try_get_registration(struct vfio_device *device) 322 { 323 return refcount_inc_not_zero(&device->refcount); 324 } 325 326 static struct vfio_device *vfio_group_get_device(struct vfio_group *group, 327 struct device *dev) 328 { 329 struct vfio_device *device; 330 331 mutex_lock(&group->device_lock); 332 list_for_each_entry(device, &group->device_list, group_next) { 333 if (device->dev == dev && 334 vfio_device_try_get_registration(device)) { 335 mutex_unlock(&group->device_lock); 336 return device; 337 } 338 } 339 mutex_unlock(&group->device_lock); 340 return NULL; 341 } 342 343 /* 344 * VFIO driver API 345 */ 346 /* Release helper called by vfio_put_device() */ 347 static void vfio_device_release(struct device *dev) 348 { 349 struct vfio_device *device = 350 container_of(dev, struct vfio_device, device); 351 352 vfio_release_device_set(device); 353 ida_free(&vfio.device_ida, device->index); 354 355 /* 356 * kvfree() cannot be done here due to a life cycle mess in 357 * vfio-ccw. Before the ccw part is fixed all drivers are 358 * required to support @release and call vfio_free_device() 359 * from there. 360 */ 361 device->ops->release(device); 362 } 363 364 /* 365 * Allocate and initialize vfio_device so it can be registered to vfio 366 * core. 367 * 368 * Drivers should use the wrapper vfio_alloc_device() for allocation. 369 * @size is the size of the structure to be allocated, including any 370 * private data used by the driver. 371 * 372 * Driver may provide an @init callback to cover device private data. 373 * 374 * Use vfio_put_device() to release the structure after success return. 375 */ 376 struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, 377 const struct vfio_device_ops *ops) 378 { 379 struct vfio_device *device; 380 int ret; 381 382 if (WARN_ON(size < sizeof(struct vfio_device))) 383 return ERR_PTR(-EINVAL); 384 385 device = kvzalloc(size, GFP_KERNEL); 386 if (!device) 387 return ERR_PTR(-ENOMEM); 388 389 ret = vfio_init_device(device, dev, ops); 390 if (ret) 391 goto out_free; 392 return device; 393 394 out_free: 395 kvfree(device); 396 return ERR_PTR(ret); 397 } 398 EXPORT_SYMBOL_GPL(_vfio_alloc_device); 399 400 /* 401 * Initialize a vfio_device so it can be registered to vfio core. 402 * 403 * Only vfio-ccw driver should call this interface. 404 */ 405 int vfio_init_device(struct vfio_device *device, struct device *dev, 406 const struct vfio_device_ops *ops) 407 { 408 int ret; 409 410 ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); 411 if (ret < 0) { 412 dev_dbg(dev, "Error to alloc index\n"); 413 return ret; 414 } 415 416 device->index = ret; 417 init_completion(&device->comp); 418 device->dev = dev; 419 device->ops = ops; 420 421 if (ops->init) { 422 ret = ops->init(device); 423 if (ret) 424 goto out_uninit; 425 } 426 427 device_initialize(&device->device); 428 device->device.release = vfio_device_release; 429 device->device.class = vfio.device_class; 430 device->device.parent = device->dev; 431 return 0; 432 433 out_uninit: 434 vfio_release_device_set(device); 435 ida_free(&vfio.device_ida, device->index); 436 return ret; 437 } 438 EXPORT_SYMBOL_GPL(vfio_init_device); 439 440 /* 441 * The helper called by driver @release callback to free the device 442 * structure. Drivers which don't have private data to clean can 443 * simply use this helper as its @release. 444 */ 445 void vfio_free_device(struct vfio_device *device) 446 { 447 kvfree(device); 448 } 449 EXPORT_SYMBOL_GPL(vfio_free_device); 450 451 static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev, 452 enum vfio_group_type type) 453 { 454 struct iommu_group *iommu_group; 455 struct vfio_group *group; 456 int ret; 457 458 iommu_group = iommu_group_alloc(); 459 if (IS_ERR(iommu_group)) 460 return ERR_CAST(iommu_group); 461 462 ret = iommu_group_set_name(iommu_group, "vfio-noiommu"); 463 if (ret) 464 goto out_put_group; 465 ret = iommu_group_add_device(iommu_group, dev); 466 if (ret) 467 goto out_put_group; 468 469 group = vfio_create_group(iommu_group, type); 470 if (IS_ERR(group)) { 471 ret = PTR_ERR(group); 472 goto out_remove_device; 473 } 474 iommu_group_put(iommu_group); 475 return group; 476 477 out_remove_device: 478 iommu_group_remove_device(dev); 479 out_put_group: 480 iommu_group_put(iommu_group); 481 return ERR_PTR(ret); 482 } 483 484 static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) 485 { 486 struct iommu_group *iommu_group; 487 struct vfio_group *group; 488 489 iommu_group = iommu_group_get(dev); 490 if (!iommu_group && vfio_noiommu) { 491 /* 492 * With noiommu enabled, create an IOMMU group for devices that 493 * don't already have one, implying no IOMMU hardware/driver 494 * exists. Taint the kernel because we're about to give a DMA 495 * capable device to a user without IOMMU protection. 496 */ 497 group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU); 498 if (!IS_ERR(group)) { 499 add_taint(TAINT_USER, LOCKDEP_STILL_OK); 500 dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n"); 501 } 502 return group; 503 } 504 505 if (!iommu_group) 506 return ERR_PTR(-EINVAL); 507 508 /* 509 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to 510 * restore cache coherency. It has to be checked here because it is only 511 * valid for cases where we are using iommu groups. 512 */ 513 if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) { 514 iommu_group_put(iommu_group); 515 return ERR_PTR(-EINVAL); 516 } 517 518 group = vfio_group_get_from_iommu(iommu_group); 519 if (!group) 520 group = vfio_create_group(iommu_group, VFIO_IOMMU); 521 522 /* The vfio_group holds a reference to the iommu_group */ 523 iommu_group_put(iommu_group); 524 return group; 525 } 526 527 static int __vfio_register_dev(struct vfio_device *device, 528 struct vfio_group *group) 529 { 530 struct vfio_device *existing_device; 531 int ret; 532 533 /* 534 * In all cases group is the output of one of the group allocation 535 * functions and we have group->drivers incremented for us. 536 */ 537 if (IS_ERR(group)) 538 return PTR_ERR(group); 539 540 /* 541 * If the driver doesn't specify a set then the device is added to a 542 * singleton set just for itself. 543 */ 544 if (!device->dev_set) 545 vfio_assign_device_set(device, device); 546 547 existing_device = vfio_group_get_device(group, device->dev); 548 if (existing_device) { 549 /* 550 * group->iommu_group is non-NULL because we hold the drivers 551 * refcount. 552 */ 553 dev_WARN(device->dev, "Device already exists on group %d\n", 554 iommu_group_id(group->iommu_group)); 555 vfio_device_put_registration(existing_device); 556 ret = -EBUSY; 557 goto err_out; 558 } 559 560 /* Our reference on group is moved to the device */ 561 device->group = group; 562 563 ret = dev_set_name(&device->device, "vfio%d", device->index); 564 if (ret) 565 goto err_out; 566 567 ret = device_add(&device->device); 568 if (ret) 569 goto err_out; 570 571 /* Refcounting can't start until the driver calls register */ 572 refcount_set(&device->refcount, 1); 573 574 mutex_lock(&group->device_lock); 575 list_add(&device->group_next, &group->device_list); 576 mutex_unlock(&group->device_lock); 577 578 return 0; 579 err_out: 580 vfio_device_remove_group(device); 581 return ret; 582 } 583 584 int vfio_register_group_dev(struct vfio_device *device) 585 { 586 return __vfio_register_dev(device, 587 vfio_group_find_or_alloc(device->dev)); 588 } 589 EXPORT_SYMBOL_GPL(vfio_register_group_dev); 590 591 /* 592 * Register a virtual device without IOMMU backing. The user of this 593 * device must not be able to directly trigger unmediated DMA. 594 */ 595 int vfio_register_emulated_iommu_dev(struct vfio_device *device) 596 { 597 return __vfio_register_dev(device, 598 vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU)); 599 } 600 EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev); 601 602 static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, 603 char *buf) 604 { 605 struct vfio_device *it, *device = ERR_PTR(-ENODEV); 606 607 mutex_lock(&group->device_lock); 608 list_for_each_entry(it, &group->device_list, group_next) { 609 int ret; 610 611 if (it->ops->match) { 612 ret = it->ops->match(it, buf); 613 if (ret < 0) { 614 device = ERR_PTR(ret); 615 break; 616 } 617 } else { 618 ret = !strcmp(dev_name(it->dev), buf); 619 } 620 621 if (ret && vfio_device_try_get_registration(it)) { 622 device = it; 623 break; 624 } 625 } 626 mutex_unlock(&group->device_lock); 627 628 return device; 629 } 630 631 /* 632 * Decrement the device reference count and wait for the device to be 633 * removed. Open file descriptors for the device... */ 634 void vfio_unregister_group_dev(struct vfio_device *device) 635 { 636 struct vfio_group *group = device->group; 637 unsigned int i = 0; 638 bool interrupted = false; 639 long rc; 640 641 vfio_device_put_registration(device); 642 rc = try_wait_for_completion(&device->comp); 643 while (rc <= 0) { 644 if (device->ops->request) 645 device->ops->request(device, i++); 646 647 if (interrupted) { 648 rc = wait_for_completion_timeout(&device->comp, 649 HZ * 10); 650 } else { 651 rc = wait_for_completion_interruptible_timeout( 652 &device->comp, HZ * 10); 653 if (rc < 0) { 654 interrupted = true; 655 dev_warn(device->dev, 656 "Device is currently in use, task" 657 " \"%s\" (%d) " 658 "blocked until device is released", 659 current->comm, task_pid_nr(current)); 660 } 661 } 662 } 663 664 mutex_lock(&group->device_lock); 665 list_del(&device->group_next); 666 mutex_unlock(&group->device_lock); 667 668 /* Balances device_add in register path */ 669 device_del(&device->device); 670 671 vfio_device_remove_group(device); 672 } 673 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev); 674 675 /* 676 * VFIO Group fd, /dev/vfio/$GROUP 677 */ 678 /* 679 * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or 680 * if there was no container to unset. Since the ioctl is called on 681 * the group, we know that still exists, therefore the only valid 682 * transition here is 1->0. 683 */ 684 static int vfio_group_ioctl_unset_container(struct vfio_group *group) 685 { 686 int ret = 0; 687 688 mutex_lock(&group->group_lock); 689 if (!group->container) { 690 ret = -EINVAL; 691 goto out_unlock; 692 } 693 if (group->container_users != 1) { 694 ret = -EBUSY; 695 goto out_unlock; 696 } 697 vfio_group_detach_container(group); 698 699 out_unlock: 700 mutex_unlock(&group->group_lock); 701 return ret; 702 } 703 704 static int vfio_group_ioctl_set_container(struct vfio_group *group, 705 int __user *arg) 706 { 707 struct vfio_container *container; 708 struct fd f; 709 int ret; 710 int fd; 711 712 if (get_user(fd, arg)) 713 return -EFAULT; 714 715 f = fdget(fd); 716 if (!f.file) 717 return -EBADF; 718 719 mutex_lock(&group->group_lock); 720 if (group->container || WARN_ON(group->container_users)) { 721 ret = -EINVAL; 722 goto out_unlock; 723 } 724 if (!group->iommu_group) { 725 ret = -ENODEV; 726 goto out_unlock; 727 } 728 729 container = vfio_container_from_file(f.file); 730 ret = -EINVAL; 731 if (container) { 732 ret = vfio_container_attach_group(container, group); 733 goto out_unlock; 734 } 735 736 out_unlock: 737 mutex_unlock(&group->group_lock); 738 fdput(f); 739 return ret; 740 } 741 742 static const struct file_operations vfio_device_fops; 743 744 /* true if the vfio_device has open_device() called but not close_device() */ 745 bool vfio_assert_device_open(struct vfio_device *device) 746 { 747 return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); 748 } 749 750 static struct file *vfio_device_open(struct vfio_device *device) 751 { 752 struct file *filep; 753 int ret; 754 755 mutex_lock(&device->group->group_lock); 756 ret = vfio_device_assign_container(device); 757 mutex_unlock(&device->group->group_lock); 758 if (ret) 759 return ERR_PTR(ret); 760 761 if (!try_module_get(device->dev->driver->owner)) { 762 ret = -ENODEV; 763 goto err_unassign_container; 764 } 765 766 mutex_lock(&device->dev_set->lock); 767 device->open_count++; 768 if (device->open_count == 1) { 769 /* 770 * Here we pass the KVM pointer with the group under the read 771 * lock. If the device driver will use it, it must obtain a 772 * reference and release it during close_device. 773 */ 774 mutex_lock(&device->group->group_lock); 775 device->kvm = device->group->kvm; 776 777 if (device->ops->open_device) { 778 ret = device->ops->open_device(device); 779 if (ret) 780 goto err_undo_count; 781 } 782 vfio_device_container_register(device); 783 mutex_unlock(&device->group->group_lock); 784 } 785 mutex_unlock(&device->dev_set->lock); 786 787 /* 788 * We can't use anon_inode_getfd() because we need to modify 789 * the f_mode flags directly to allow more than just ioctls 790 */ 791 filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, 792 device, O_RDWR); 793 if (IS_ERR(filep)) { 794 ret = PTR_ERR(filep); 795 goto err_close_device; 796 } 797 798 /* 799 * TODO: add an anon_inode interface to do this. 800 * Appears to be missing by lack of need rather than 801 * explicitly prevented. Now there's need. 802 */ 803 filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE); 804 805 if (device->group->type == VFIO_NO_IOMMU) 806 dev_warn(device->dev, "vfio-noiommu device opened by user " 807 "(%s:%d)\n", current->comm, task_pid_nr(current)); 808 /* 809 * On success the ref of device is moved to the file and 810 * put in vfio_device_fops_release() 811 */ 812 return filep; 813 814 err_close_device: 815 mutex_lock(&device->dev_set->lock); 816 mutex_lock(&device->group->group_lock); 817 if (device->open_count == 1) { 818 if (device->ops->close_device) 819 device->ops->close_device(device); 820 821 vfio_device_container_unregister(device); 822 } 823 err_undo_count: 824 mutex_unlock(&device->group->group_lock); 825 device->open_count--; 826 if (device->open_count == 0 && device->kvm) 827 device->kvm = NULL; 828 mutex_unlock(&device->dev_set->lock); 829 module_put(device->dev->driver->owner); 830 err_unassign_container: 831 vfio_device_unassign_container(device); 832 return ERR_PTR(ret); 833 } 834 835 static int vfio_group_ioctl_get_device_fd(struct vfio_group *group, 836 char __user *arg) 837 { 838 struct vfio_device *device; 839 struct file *filep; 840 char *buf; 841 int fdno; 842 int ret; 843 844 buf = strndup_user(arg, PAGE_SIZE); 845 if (IS_ERR(buf)) 846 return PTR_ERR(buf); 847 848 device = vfio_device_get_from_name(group, buf); 849 kfree(buf); 850 if (IS_ERR(device)) 851 return PTR_ERR(device); 852 853 fdno = get_unused_fd_flags(O_CLOEXEC); 854 if (fdno < 0) { 855 ret = fdno; 856 goto err_put_device; 857 } 858 859 filep = vfio_device_open(device); 860 if (IS_ERR(filep)) { 861 ret = PTR_ERR(filep); 862 goto err_put_fdno; 863 } 864 865 fd_install(fdno, filep); 866 return fdno; 867 868 err_put_fdno: 869 put_unused_fd(fdno); 870 err_put_device: 871 vfio_device_put_registration(device); 872 return ret; 873 } 874 875 static int vfio_group_ioctl_get_status(struct vfio_group *group, 876 struct vfio_group_status __user *arg) 877 { 878 unsigned long minsz = offsetofend(struct vfio_group_status, flags); 879 struct vfio_group_status status; 880 881 if (copy_from_user(&status, arg, minsz)) 882 return -EFAULT; 883 884 if (status.argsz < minsz) 885 return -EINVAL; 886 887 status.flags = 0; 888 889 mutex_lock(&group->group_lock); 890 if (!group->iommu_group) { 891 mutex_unlock(&group->group_lock); 892 return -ENODEV; 893 } 894 895 if (group->container) 896 status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET | 897 VFIO_GROUP_FLAGS_VIABLE; 898 else if (!iommu_group_dma_owner_claimed(group->iommu_group)) 899 status.flags |= VFIO_GROUP_FLAGS_VIABLE; 900 mutex_unlock(&group->group_lock); 901 902 if (copy_to_user(arg, &status, minsz)) 903 return -EFAULT; 904 return 0; 905 } 906 907 static long vfio_group_fops_unl_ioctl(struct file *filep, 908 unsigned int cmd, unsigned long arg) 909 { 910 struct vfio_group *group = filep->private_data; 911 void __user *uarg = (void __user *)arg; 912 913 switch (cmd) { 914 case VFIO_GROUP_GET_DEVICE_FD: 915 return vfio_group_ioctl_get_device_fd(group, uarg); 916 case VFIO_GROUP_GET_STATUS: 917 return vfio_group_ioctl_get_status(group, uarg); 918 case VFIO_GROUP_SET_CONTAINER: 919 return vfio_group_ioctl_set_container(group, uarg); 920 case VFIO_GROUP_UNSET_CONTAINER: 921 return vfio_group_ioctl_unset_container(group); 922 default: 923 return -ENOTTY; 924 } 925 } 926 927 static int vfio_group_fops_open(struct inode *inode, struct file *filep) 928 { 929 struct vfio_group *group = 930 container_of(inode->i_cdev, struct vfio_group, cdev); 931 int ret; 932 933 mutex_lock(&group->group_lock); 934 935 /* 936 * drivers can be zero if this races with vfio_device_remove_group(), it 937 * will be stable at 0 under the group rwsem 938 */ 939 if (refcount_read(&group->drivers) == 0) { 940 ret = -ENODEV; 941 goto out_unlock; 942 } 943 944 if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) { 945 ret = -EPERM; 946 goto out_unlock; 947 } 948 949 /* 950 * Do we need multiple instances of the group open? Seems not. 951 */ 952 if (group->opened_file) { 953 ret = -EBUSY; 954 goto out_unlock; 955 } 956 group->opened_file = filep; 957 filep->private_data = group; 958 ret = 0; 959 out_unlock: 960 mutex_unlock(&group->group_lock); 961 return ret; 962 } 963 964 static int vfio_group_fops_release(struct inode *inode, struct file *filep) 965 { 966 struct vfio_group *group = filep->private_data; 967 968 filep->private_data = NULL; 969 970 mutex_lock(&group->group_lock); 971 /* 972 * Device FDs hold a group file reference, therefore the group release 973 * is only called when there are no open devices. 974 */ 975 WARN_ON(group->notifier.head); 976 if (group->container) 977 vfio_group_detach_container(group); 978 group->opened_file = NULL; 979 mutex_unlock(&group->group_lock); 980 return 0; 981 } 982 983 static const struct file_operations vfio_group_fops = { 984 .owner = THIS_MODULE, 985 .unlocked_ioctl = vfio_group_fops_unl_ioctl, 986 .compat_ioctl = compat_ptr_ioctl, 987 .open = vfio_group_fops_open, 988 .release = vfio_group_fops_release, 989 }; 990 991 /* 992 * Wrapper around pm_runtime_resume_and_get(). 993 * Return error code on failure or 0 on success. 994 */ 995 static inline int vfio_device_pm_runtime_get(struct vfio_device *device) 996 { 997 struct device *dev = device->dev; 998 999 if (dev->driver && dev->driver->pm) { 1000 int ret; 1001 1002 ret = pm_runtime_resume_and_get(dev); 1003 if (ret) { 1004 dev_info_ratelimited(dev, 1005 "vfio: runtime resume failed %d\n", ret); 1006 return -EIO; 1007 } 1008 } 1009 1010 return 0; 1011 } 1012 1013 /* 1014 * Wrapper around pm_runtime_put(). 1015 */ 1016 static inline void vfio_device_pm_runtime_put(struct vfio_device *device) 1017 { 1018 struct device *dev = device->dev; 1019 1020 if (dev->driver && dev->driver->pm) 1021 pm_runtime_put(dev); 1022 } 1023 1024 /* 1025 * VFIO Device fd 1026 */ 1027 static int vfio_device_fops_release(struct inode *inode, struct file *filep) 1028 { 1029 struct vfio_device *device = filep->private_data; 1030 1031 mutex_lock(&device->dev_set->lock); 1032 vfio_assert_device_open(device); 1033 mutex_lock(&device->group->group_lock); 1034 if (device->open_count == 1) { 1035 if (device->ops->close_device) 1036 device->ops->close_device(device); 1037 1038 vfio_device_container_unregister(device); 1039 } 1040 mutex_unlock(&device->group->group_lock); 1041 device->open_count--; 1042 if (device->open_count == 0) 1043 device->kvm = NULL; 1044 mutex_unlock(&device->dev_set->lock); 1045 1046 module_put(device->dev->driver->owner); 1047 1048 vfio_device_unassign_container(device); 1049 1050 vfio_device_put_registration(device); 1051 1052 return 0; 1053 } 1054 1055 /* 1056 * vfio_mig_get_next_state - Compute the next step in the FSM 1057 * @cur_fsm - The current state the device is in 1058 * @new_fsm - The target state to reach 1059 * @next_fsm - Pointer to the next step to get to new_fsm 1060 * 1061 * Return 0 upon success, otherwise -errno 1062 * Upon success the next step in the state progression between cur_fsm and 1063 * new_fsm will be set in next_fsm. 1064 * 1065 * This breaks down requests for combination transitions into smaller steps and 1066 * returns the next step to get to new_fsm. The function may need to be called 1067 * multiple times before reaching new_fsm. 1068 * 1069 */ 1070 int vfio_mig_get_next_state(struct vfio_device *device, 1071 enum vfio_device_mig_state cur_fsm, 1072 enum vfio_device_mig_state new_fsm, 1073 enum vfio_device_mig_state *next_fsm) 1074 { 1075 enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_RUNNING_P2P + 1 }; 1076 /* 1077 * The coding in this table requires the driver to implement the 1078 * following FSM arcs: 1079 * RESUMING -> STOP 1080 * STOP -> RESUMING 1081 * STOP -> STOP_COPY 1082 * STOP_COPY -> STOP 1083 * 1084 * If P2P is supported then the driver must also implement these FSM 1085 * arcs: 1086 * RUNNING -> RUNNING_P2P 1087 * RUNNING_P2P -> RUNNING 1088 * RUNNING_P2P -> STOP 1089 * STOP -> RUNNING_P2P 1090 * Without P2P the driver must implement: 1091 * RUNNING -> STOP 1092 * STOP -> RUNNING 1093 * 1094 * The coding will step through multiple states for some combination 1095 * transitions; if all optional features are supported, this means the 1096 * following ones: 1097 * RESUMING -> STOP -> RUNNING_P2P 1098 * RESUMING -> STOP -> RUNNING_P2P -> RUNNING 1099 * RESUMING -> STOP -> STOP_COPY 1100 * RUNNING -> RUNNING_P2P -> STOP 1101 * RUNNING -> RUNNING_P2P -> STOP -> RESUMING 1102 * RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY 1103 * RUNNING_P2P -> STOP -> RESUMING 1104 * RUNNING_P2P -> STOP -> STOP_COPY 1105 * STOP -> RUNNING_P2P -> RUNNING 1106 * STOP_COPY -> STOP -> RESUMING 1107 * STOP_COPY -> STOP -> RUNNING_P2P 1108 * STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING 1109 */ 1110 static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = { 1111 [VFIO_DEVICE_STATE_STOP] = { 1112 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1113 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P, 1114 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, 1115 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING, 1116 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, 1117 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1118 }, 1119 [VFIO_DEVICE_STATE_RUNNING] = { 1120 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P, 1121 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING, 1122 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P, 1123 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P, 1124 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, 1125 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1126 }, 1127 [VFIO_DEVICE_STATE_STOP_COPY] = { 1128 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1129 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP, 1130 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, 1131 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP, 1132 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP, 1133 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1134 }, 1135 [VFIO_DEVICE_STATE_RESUMING] = { 1136 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1137 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP, 1138 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, 1139 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING, 1140 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP, 1141 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1142 }, 1143 [VFIO_DEVICE_STATE_RUNNING_P2P] = { 1144 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP, 1145 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING, 1146 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, 1147 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP, 1148 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P, 1149 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1150 }, 1151 [VFIO_DEVICE_STATE_ERROR] = { 1152 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR, 1153 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR, 1154 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR, 1155 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR, 1156 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR, 1157 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, 1158 }, 1159 }; 1160 1161 static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = { 1162 [VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY, 1163 [VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY, 1164 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY, 1165 [VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY, 1166 [VFIO_DEVICE_STATE_RUNNING_P2P] = 1167 VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P, 1168 [VFIO_DEVICE_STATE_ERROR] = ~0U, 1169 }; 1170 1171 if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) || 1172 (state_flags_table[cur_fsm] & device->migration_flags) != 1173 state_flags_table[cur_fsm])) 1174 return -EINVAL; 1175 1176 if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) || 1177 (state_flags_table[new_fsm] & device->migration_flags) != 1178 state_flags_table[new_fsm]) 1179 return -EINVAL; 1180 1181 /* 1182 * Arcs touching optional and unsupported states are skipped over. The 1183 * driver will instead see an arc from the original state to the next 1184 * logical state, as per the above comment. 1185 */ 1186 *next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm]; 1187 while ((state_flags_table[*next_fsm] & device->migration_flags) != 1188 state_flags_table[*next_fsm]) 1189 *next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm]; 1190 1191 return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL; 1192 } 1193 EXPORT_SYMBOL_GPL(vfio_mig_get_next_state); 1194 1195 /* 1196 * Convert the drivers's struct file into a FD number and return it to userspace 1197 */ 1198 static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg, 1199 struct vfio_device_feature_mig_state *mig) 1200 { 1201 int ret; 1202 int fd; 1203 1204 fd = get_unused_fd_flags(O_CLOEXEC); 1205 if (fd < 0) { 1206 ret = fd; 1207 goto out_fput; 1208 } 1209 1210 mig->data_fd = fd; 1211 if (copy_to_user(arg, mig, sizeof(*mig))) { 1212 ret = -EFAULT; 1213 goto out_put_unused; 1214 } 1215 fd_install(fd, filp); 1216 return 0; 1217 1218 out_put_unused: 1219 put_unused_fd(fd); 1220 out_fput: 1221 fput(filp); 1222 return ret; 1223 } 1224 1225 static int 1226 vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device, 1227 u32 flags, void __user *arg, 1228 size_t argsz) 1229 { 1230 size_t minsz = 1231 offsetofend(struct vfio_device_feature_mig_state, data_fd); 1232 struct vfio_device_feature_mig_state mig; 1233 struct file *filp = NULL; 1234 int ret; 1235 1236 if (!device->mig_ops) 1237 return -ENOTTY; 1238 1239 ret = vfio_check_feature(flags, argsz, 1240 VFIO_DEVICE_FEATURE_SET | 1241 VFIO_DEVICE_FEATURE_GET, 1242 sizeof(mig)); 1243 if (ret != 1) 1244 return ret; 1245 1246 if (copy_from_user(&mig, arg, minsz)) 1247 return -EFAULT; 1248 1249 if (flags & VFIO_DEVICE_FEATURE_GET) { 1250 enum vfio_device_mig_state curr_state; 1251 1252 ret = device->mig_ops->migration_get_state(device, 1253 &curr_state); 1254 if (ret) 1255 return ret; 1256 mig.device_state = curr_state; 1257 goto out_copy; 1258 } 1259 1260 /* Handle the VFIO_DEVICE_FEATURE_SET */ 1261 filp = device->mig_ops->migration_set_state(device, mig.device_state); 1262 if (IS_ERR(filp) || !filp) 1263 goto out_copy; 1264 1265 return vfio_ioct_mig_return_fd(filp, arg, &mig); 1266 out_copy: 1267 mig.data_fd = -1; 1268 if (copy_to_user(arg, &mig, sizeof(mig))) 1269 return -EFAULT; 1270 if (IS_ERR(filp)) 1271 return PTR_ERR(filp); 1272 return 0; 1273 } 1274 1275 static int vfio_ioctl_device_feature_migration(struct vfio_device *device, 1276 u32 flags, void __user *arg, 1277 size_t argsz) 1278 { 1279 struct vfio_device_feature_migration mig = { 1280 .flags = device->migration_flags, 1281 }; 1282 int ret; 1283 1284 if (!device->mig_ops) 1285 return -ENOTTY; 1286 1287 ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET, 1288 sizeof(mig)); 1289 if (ret != 1) 1290 return ret; 1291 if (copy_to_user(arg, &mig, sizeof(mig))) 1292 return -EFAULT; 1293 return 0; 1294 } 1295 1296 /* Ranges should fit into a single kernel page */ 1297 #define LOG_MAX_RANGES \ 1298 (PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range)) 1299 1300 static int 1301 vfio_ioctl_device_feature_logging_start(struct vfio_device *device, 1302 u32 flags, void __user *arg, 1303 size_t argsz) 1304 { 1305 size_t minsz = 1306 offsetofend(struct vfio_device_feature_dma_logging_control, 1307 ranges); 1308 struct vfio_device_feature_dma_logging_range __user *ranges; 1309 struct vfio_device_feature_dma_logging_control control; 1310 struct vfio_device_feature_dma_logging_range range; 1311 struct rb_root_cached root = RB_ROOT_CACHED; 1312 struct interval_tree_node *nodes; 1313 u64 iova_end; 1314 u32 nnodes; 1315 int i, ret; 1316 1317 if (!device->log_ops) 1318 return -ENOTTY; 1319 1320 ret = vfio_check_feature(flags, argsz, 1321 VFIO_DEVICE_FEATURE_SET, 1322 sizeof(control)); 1323 if (ret != 1) 1324 return ret; 1325 1326 if (copy_from_user(&control, arg, minsz)) 1327 return -EFAULT; 1328 1329 nnodes = control.num_ranges; 1330 if (!nnodes) 1331 return -EINVAL; 1332 1333 if (nnodes > LOG_MAX_RANGES) 1334 return -E2BIG; 1335 1336 ranges = u64_to_user_ptr(control.ranges); 1337 nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node), 1338 GFP_KERNEL); 1339 if (!nodes) 1340 return -ENOMEM; 1341 1342 for (i = 0; i < nnodes; i++) { 1343 if (copy_from_user(&range, &ranges[i], sizeof(range))) { 1344 ret = -EFAULT; 1345 goto end; 1346 } 1347 if (!IS_ALIGNED(range.iova, control.page_size) || 1348 !IS_ALIGNED(range.length, control.page_size)) { 1349 ret = -EINVAL; 1350 goto end; 1351 } 1352 1353 if (check_add_overflow(range.iova, range.length, &iova_end) || 1354 iova_end > ULONG_MAX) { 1355 ret = -EOVERFLOW; 1356 goto end; 1357 } 1358 1359 nodes[i].start = range.iova; 1360 nodes[i].last = range.iova + range.length - 1; 1361 if (interval_tree_iter_first(&root, nodes[i].start, 1362 nodes[i].last)) { 1363 /* Range overlapping */ 1364 ret = -EINVAL; 1365 goto end; 1366 } 1367 interval_tree_insert(nodes + i, &root); 1368 } 1369 1370 ret = device->log_ops->log_start(device, &root, nnodes, 1371 &control.page_size); 1372 if (ret) 1373 goto end; 1374 1375 if (copy_to_user(arg, &control, sizeof(control))) { 1376 ret = -EFAULT; 1377 device->log_ops->log_stop(device); 1378 } 1379 1380 end: 1381 kfree(nodes); 1382 return ret; 1383 } 1384 1385 static int 1386 vfio_ioctl_device_feature_logging_stop(struct vfio_device *device, 1387 u32 flags, void __user *arg, 1388 size_t argsz) 1389 { 1390 int ret; 1391 1392 if (!device->log_ops) 1393 return -ENOTTY; 1394 1395 ret = vfio_check_feature(flags, argsz, 1396 VFIO_DEVICE_FEATURE_SET, 0); 1397 if (ret != 1) 1398 return ret; 1399 1400 return device->log_ops->log_stop(device); 1401 } 1402 1403 static int vfio_device_log_read_and_clear(struct iova_bitmap *iter, 1404 unsigned long iova, size_t length, 1405 void *opaque) 1406 { 1407 struct vfio_device *device = opaque; 1408 1409 return device->log_ops->log_read_and_clear(device, iova, length, iter); 1410 } 1411 1412 static int 1413 vfio_ioctl_device_feature_logging_report(struct vfio_device *device, 1414 u32 flags, void __user *arg, 1415 size_t argsz) 1416 { 1417 size_t minsz = 1418 offsetofend(struct vfio_device_feature_dma_logging_report, 1419 bitmap); 1420 struct vfio_device_feature_dma_logging_report report; 1421 struct iova_bitmap *iter; 1422 u64 iova_end; 1423 int ret; 1424 1425 if (!device->log_ops) 1426 return -ENOTTY; 1427 1428 ret = vfio_check_feature(flags, argsz, 1429 VFIO_DEVICE_FEATURE_GET, 1430 sizeof(report)); 1431 if (ret != 1) 1432 return ret; 1433 1434 if (copy_from_user(&report, arg, minsz)) 1435 return -EFAULT; 1436 1437 if (report.page_size < SZ_4K || !is_power_of_2(report.page_size)) 1438 return -EINVAL; 1439 1440 if (check_add_overflow(report.iova, report.length, &iova_end) || 1441 iova_end > ULONG_MAX) 1442 return -EOVERFLOW; 1443 1444 iter = iova_bitmap_alloc(report.iova, report.length, 1445 report.page_size, 1446 u64_to_user_ptr(report.bitmap)); 1447 if (IS_ERR(iter)) 1448 return PTR_ERR(iter); 1449 1450 ret = iova_bitmap_for_each(iter, device, 1451 vfio_device_log_read_and_clear); 1452 1453 iova_bitmap_free(iter); 1454 return ret; 1455 } 1456 1457 static int vfio_ioctl_device_feature(struct vfio_device *device, 1458 struct vfio_device_feature __user *arg) 1459 { 1460 size_t minsz = offsetofend(struct vfio_device_feature, flags); 1461 struct vfio_device_feature feature; 1462 1463 if (copy_from_user(&feature, arg, minsz)) 1464 return -EFAULT; 1465 1466 if (feature.argsz < minsz) 1467 return -EINVAL; 1468 1469 /* Check unknown flags */ 1470 if (feature.flags & 1471 ~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET | 1472 VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE)) 1473 return -EINVAL; 1474 1475 /* GET & SET are mutually exclusive except with PROBE */ 1476 if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) && 1477 (feature.flags & VFIO_DEVICE_FEATURE_SET) && 1478 (feature.flags & VFIO_DEVICE_FEATURE_GET)) 1479 return -EINVAL; 1480 1481 switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) { 1482 case VFIO_DEVICE_FEATURE_MIGRATION: 1483 return vfio_ioctl_device_feature_migration( 1484 device, feature.flags, arg->data, 1485 feature.argsz - minsz); 1486 case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE: 1487 return vfio_ioctl_device_feature_mig_device_state( 1488 device, feature.flags, arg->data, 1489 feature.argsz - minsz); 1490 case VFIO_DEVICE_FEATURE_DMA_LOGGING_START: 1491 return vfio_ioctl_device_feature_logging_start( 1492 device, feature.flags, arg->data, 1493 feature.argsz - minsz); 1494 case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP: 1495 return vfio_ioctl_device_feature_logging_stop( 1496 device, feature.flags, arg->data, 1497 feature.argsz - minsz); 1498 case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT: 1499 return vfio_ioctl_device_feature_logging_report( 1500 device, feature.flags, arg->data, 1501 feature.argsz - minsz); 1502 default: 1503 if (unlikely(!device->ops->device_feature)) 1504 return -EINVAL; 1505 return device->ops->device_feature(device, feature.flags, 1506 arg->data, 1507 feature.argsz - minsz); 1508 } 1509 } 1510 1511 static long vfio_device_fops_unl_ioctl(struct file *filep, 1512 unsigned int cmd, unsigned long arg) 1513 { 1514 struct vfio_device *device = filep->private_data; 1515 int ret; 1516 1517 ret = vfio_device_pm_runtime_get(device); 1518 if (ret) 1519 return ret; 1520 1521 switch (cmd) { 1522 case VFIO_DEVICE_FEATURE: 1523 ret = vfio_ioctl_device_feature(device, (void __user *)arg); 1524 break; 1525 1526 default: 1527 if (unlikely(!device->ops->ioctl)) 1528 ret = -EINVAL; 1529 else 1530 ret = device->ops->ioctl(device, cmd, arg); 1531 break; 1532 } 1533 1534 vfio_device_pm_runtime_put(device); 1535 return ret; 1536 } 1537 1538 static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf, 1539 size_t count, loff_t *ppos) 1540 { 1541 struct vfio_device *device = filep->private_data; 1542 1543 if (unlikely(!device->ops->read)) 1544 return -EINVAL; 1545 1546 return device->ops->read(device, buf, count, ppos); 1547 } 1548 1549 static ssize_t vfio_device_fops_write(struct file *filep, 1550 const char __user *buf, 1551 size_t count, loff_t *ppos) 1552 { 1553 struct vfio_device *device = filep->private_data; 1554 1555 if (unlikely(!device->ops->write)) 1556 return -EINVAL; 1557 1558 return device->ops->write(device, buf, count, ppos); 1559 } 1560 1561 static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma) 1562 { 1563 struct vfio_device *device = filep->private_data; 1564 1565 if (unlikely(!device->ops->mmap)) 1566 return -EINVAL; 1567 1568 return device->ops->mmap(device, vma); 1569 } 1570 1571 static const struct file_operations vfio_device_fops = { 1572 .owner = THIS_MODULE, 1573 .release = vfio_device_fops_release, 1574 .read = vfio_device_fops_read, 1575 .write = vfio_device_fops_write, 1576 .unlocked_ioctl = vfio_device_fops_unl_ioctl, 1577 .compat_ioctl = compat_ptr_ioctl, 1578 .mmap = vfio_device_fops_mmap, 1579 }; 1580 1581 /** 1582 * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file 1583 * @file: VFIO group file 1584 * 1585 * The returned iommu_group is valid as long as a ref is held on the file. This 1586 * returns a reference on the group. This function is deprecated, only the SPAPR 1587 * path in kvm should call it. 1588 */ 1589 struct iommu_group *vfio_file_iommu_group(struct file *file) 1590 { 1591 struct vfio_group *group = file->private_data; 1592 struct iommu_group *iommu_group = NULL; 1593 1594 if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU)) 1595 return NULL; 1596 1597 if (!vfio_file_is_group(file)) 1598 return NULL; 1599 1600 mutex_lock(&group->group_lock); 1601 if (group->iommu_group) { 1602 iommu_group = group->iommu_group; 1603 iommu_group_ref_get(iommu_group); 1604 } 1605 mutex_unlock(&group->group_lock); 1606 return iommu_group; 1607 } 1608 EXPORT_SYMBOL_GPL(vfio_file_iommu_group); 1609 1610 /** 1611 * vfio_file_is_group - True if the file is usable with VFIO aPIS 1612 * @file: VFIO group file 1613 */ 1614 bool vfio_file_is_group(struct file *file) 1615 { 1616 return file->f_op == &vfio_group_fops; 1617 } 1618 EXPORT_SYMBOL_GPL(vfio_file_is_group); 1619 1620 /** 1621 * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file 1622 * is always CPU cache coherent 1623 * @file: VFIO group file 1624 * 1625 * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop 1626 * bit in DMA transactions. A return of false indicates that the user has 1627 * rights to access additional instructions such as wbinvd on x86. 1628 */ 1629 bool vfio_file_enforced_coherent(struct file *file) 1630 { 1631 struct vfio_group *group = file->private_data; 1632 bool ret; 1633 1634 if (!vfio_file_is_group(file)) 1635 return true; 1636 1637 mutex_lock(&group->group_lock); 1638 if (group->container) { 1639 ret = vfio_container_ioctl_check_extension(group->container, 1640 VFIO_DMA_CC_IOMMU); 1641 } else { 1642 /* 1643 * Since the coherency state is determined only once a container 1644 * is attached the user must do so before they can prove they 1645 * have permission. 1646 */ 1647 ret = true; 1648 } 1649 mutex_unlock(&group->group_lock); 1650 return ret; 1651 } 1652 EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); 1653 1654 /** 1655 * vfio_file_set_kvm - Link a kvm with VFIO drivers 1656 * @file: VFIO group file 1657 * @kvm: KVM to link 1658 * 1659 * When a VFIO device is first opened the KVM will be available in 1660 * device->kvm if one was associated with the group. 1661 */ 1662 void vfio_file_set_kvm(struct file *file, struct kvm *kvm) 1663 { 1664 struct vfio_group *group = file->private_data; 1665 1666 if (!vfio_file_is_group(file)) 1667 return; 1668 1669 mutex_lock(&group->group_lock); 1670 group->kvm = kvm; 1671 mutex_unlock(&group->group_lock); 1672 } 1673 EXPORT_SYMBOL_GPL(vfio_file_set_kvm); 1674 1675 /** 1676 * vfio_file_has_dev - True if the VFIO file is a handle for device 1677 * @file: VFIO file to check 1678 * @device: Device that must be part of the file 1679 * 1680 * Returns true if given file has permission to manipulate the given device. 1681 */ 1682 bool vfio_file_has_dev(struct file *file, struct vfio_device *device) 1683 { 1684 struct vfio_group *group = file->private_data; 1685 1686 if (!vfio_file_is_group(file)) 1687 return false; 1688 1689 return group == device->group; 1690 } 1691 EXPORT_SYMBOL_GPL(vfio_file_has_dev); 1692 1693 /* 1694 * Sub-module support 1695 */ 1696 /* 1697 * Helper for managing a buffer of info chain capabilities, allocate or 1698 * reallocate a buffer with additional @size, filling in @id and @version 1699 * of the capability. A pointer to the new capability is returned. 1700 * 1701 * NB. The chain is based at the head of the buffer, so new entries are 1702 * added to the tail, vfio_info_cap_shift() should be called to fixup the 1703 * next offsets prior to copying to the user buffer. 1704 */ 1705 struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, 1706 size_t size, u16 id, u16 version) 1707 { 1708 void *buf; 1709 struct vfio_info_cap_header *header, *tmp; 1710 1711 buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL); 1712 if (!buf) { 1713 kfree(caps->buf); 1714 caps->buf = NULL; 1715 caps->size = 0; 1716 return ERR_PTR(-ENOMEM); 1717 } 1718 1719 caps->buf = buf; 1720 header = buf + caps->size; 1721 1722 /* Eventually copied to user buffer, zero */ 1723 memset(header, 0, size); 1724 1725 header->id = id; 1726 header->version = version; 1727 1728 /* Add to the end of the capability chain */ 1729 for (tmp = buf; tmp->next; tmp = buf + tmp->next) 1730 ; /* nothing */ 1731 1732 tmp->next = caps->size; 1733 caps->size += size; 1734 1735 return header; 1736 } 1737 EXPORT_SYMBOL_GPL(vfio_info_cap_add); 1738 1739 void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset) 1740 { 1741 struct vfio_info_cap_header *tmp; 1742 void *buf = (void *)caps->buf; 1743 1744 for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset) 1745 tmp->next += offset; 1746 } 1747 EXPORT_SYMBOL(vfio_info_cap_shift); 1748 1749 int vfio_info_add_capability(struct vfio_info_cap *caps, 1750 struct vfio_info_cap_header *cap, size_t size) 1751 { 1752 struct vfio_info_cap_header *header; 1753 1754 header = vfio_info_cap_add(caps, size, cap->id, cap->version); 1755 if (IS_ERR(header)) 1756 return PTR_ERR(header); 1757 1758 memcpy(header + 1, cap + 1, size - sizeof(*header)); 1759 1760 return 0; 1761 } 1762 EXPORT_SYMBOL(vfio_info_add_capability); 1763 1764 int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs, 1765 int max_irq_type, size_t *data_size) 1766 { 1767 unsigned long minsz; 1768 size_t size; 1769 1770 minsz = offsetofend(struct vfio_irq_set, count); 1771 1772 if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) || 1773 (hdr->count >= (U32_MAX - hdr->start)) || 1774 (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK | 1775 VFIO_IRQ_SET_ACTION_TYPE_MASK))) 1776 return -EINVAL; 1777 1778 if (data_size) 1779 *data_size = 0; 1780 1781 if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs) 1782 return -EINVAL; 1783 1784 switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) { 1785 case VFIO_IRQ_SET_DATA_NONE: 1786 size = 0; 1787 break; 1788 case VFIO_IRQ_SET_DATA_BOOL: 1789 size = sizeof(uint8_t); 1790 break; 1791 case VFIO_IRQ_SET_DATA_EVENTFD: 1792 size = sizeof(int32_t); 1793 break; 1794 default: 1795 return -EINVAL; 1796 } 1797 1798 if (size) { 1799 if (hdr->argsz - minsz < hdr->count * size) 1800 return -EINVAL; 1801 1802 if (!data_size) 1803 return -EINVAL; 1804 1805 *data_size = hdr->count * size; 1806 } 1807 1808 return 0; 1809 } 1810 EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); 1811 1812 /* 1813 * Module/class support 1814 */ 1815 static char *vfio_devnode(struct device *dev, umode_t *mode) 1816 { 1817 return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); 1818 } 1819 1820 static int __init vfio_init(void) 1821 { 1822 int ret; 1823 1824 ida_init(&vfio.group_ida); 1825 ida_init(&vfio.device_ida); 1826 mutex_init(&vfio.group_lock); 1827 INIT_LIST_HEAD(&vfio.group_list); 1828 1829 ret = vfio_container_init(); 1830 if (ret) 1831 return ret; 1832 1833 /* /dev/vfio/$GROUP */ 1834 vfio.class = class_create(THIS_MODULE, "vfio"); 1835 if (IS_ERR(vfio.class)) { 1836 ret = PTR_ERR(vfio.class); 1837 goto err_group_class; 1838 } 1839 1840 vfio.class->devnode = vfio_devnode; 1841 1842 /* /sys/class/vfio-dev/vfioX */ 1843 vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); 1844 if (IS_ERR(vfio.device_class)) { 1845 ret = PTR_ERR(vfio.device_class); 1846 goto err_dev_class; 1847 } 1848 1849 ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); 1850 if (ret) 1851 goto err_alloc_chrdev; 1852 1853 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); 1854 return 0; 1855 1856 err_alloc_chrdev: 1857 class_destroy(vfio.device_class); 1858 vfio.device_class = NULL; 1859 err_dev_class: 1860 class_destroy(vfio.class); 1861 vfio.class = NULL; 1862 err_group_class: 1863 vfio_container_cleanup(); 1864 return ret; 1865 } 1866 1867 static void __exit vfio_cleanup(void) 1868 { 1869 WARN_ON(!list_empty(&vfio.group_list)); 1870 1871 ida_destroy(&vfio.device_ida); 1872 ida_destroy(&vfio.group_ida); 1873 unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); 1874 class_destroy(vfio.device_class); 1875 vfio.device_class = NULL; 1876 class_destroy(vfio.class); 1877 vfio_container_cleanup(); 1878 vfio.class = NULL; 1879 xa_destroy(&vfio_device_set_xa); 1880 } 1881 1882 module_init(vfio_init); 1883 module_exit(vfio_cleanup); 1884 1885 MODULE_VERSION(DRIVER_VERSION); 1886 MODULE_LICENSE("GPL v2"); 1887 MODULE_AUTHOR(DRIVER_AUTHOR); 1888 MODULE_DESCRIPTION(DRIVER_DESC); 1889 MODULE_ALIAS_MISCDEV(VFIO_MINOR); 1890 MODULE_ALIAS("devname:vfio/vfio"); 1891 MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce"); 1892