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