1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2018-2020 Intel Corporation. 4 * Copyright (C) 2020 Red Hat, Inc. 5 * 6 * Author: Tiwei Bie <tiwei.bie@intel.com> 7 * Jason Wang <jasowang@redhat.com> 8 * 9 * Thanks Michael S. Tsirkin for the valuable comments and 10 * suggestions. And thanks to Cunming Liang and Zhihong Wang for all 11 * their supports. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/cdev.h> 17 #include <linux/device.h> 18 #include <linux/mm.h> 19 #include <linux/slab.h> 20 #include <linux/iommu.h> 21 #include <linux/uuid.h> 22 #include <linux/vdpa.h> 23 #include <linux/nospec.h> 24 #include <linux/vhost.h> 25 26 #include "vhost.h" 27 28 enum { 29 VHOST_VDPA_BACKEND_FEATURES = 30 (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) | 31 (1ULL << VHOST_BACKEND_F_IOTLB_BATCH), 32 }; 33 34 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS) 35 36 struct vhost_vdpa { 37 struct vhost_dev vdev; 38 struct iommu_domain *domain; 39 struct vhost_virtqueue *vqs; 40 struct completion completion; 41 struct vdpa_device *vdpa; 42 struct device dev; 43 struct cdev cdev; 44 atomic_t opened; 45 int nvqs; 46 int virtio_id; 47 int minor; 48 struct eventfd_ctx *config_ctx; 49 int in_batch; 50 struct vdpa_iova_range range; 51 }; 52 53 static DEFINE_IDA(vhost_vdpa_ida); 54 55 static dev_t vhost_vdpa_major; 56 57 static void handle_vq_kick(struct vhost_work *work) 58 { 59 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, 60 poll.work); 61 struct vhost_vdpa *v = container_of(vq->dev, struct vhost_vdpa, vdev); 62 const struct vdpa_config_ops *ops = v->vdpa->config; 63 64 ops->kick_vq(v->vdpa, vq - v->vqs); 65 } 66 67 static irqreturn_t vhost_vdpa_virtqueue_cb(void *private) 68 { 69 struct vhost_virtqueue *vq = private; 70 struct eventfd_ctx *call_ctx = vq->call_ctx.ctx; 71 72 if (call_ctx) 73 eventfd_signal(call_ctx, 1); 74 75 return IRQ_HANDLED; 76 } 77 78 static irqreturn_t vhost_vdpa_config_cb(void *private) 79 { 80 struct vhost_vdpa *v = private; 81 struct eventfd_ctx *config_ctx = v->config_ctx; 82 83 if (config_ctx) 84 eventfd_signal(config_ctx, 1); 85 86 return IRQ_HANDLED; 87 } 88 89 static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid) 90 { 91 struct vhost_virtqueue *vq = &v->vqs[qid]; 92 const struct vdpa_config_ops *ops = v->vdpa->config; 93 struct vdpa_device *vdpa = v->vdpa; 94 int ret, irq; 95 96 if (!ops->get_vq_irq) 97 return; 98 99 irq = ops->get_vq_irq(vdpa, qid); 100 irq_bypass_unregister_producer(&vq->call_ctx.producer); 101 if (!vq->call_ctx.ctx || irq < 0) 102 return; 103 104 vq->call_ctx.producer.token = vq->call_ctx.ctx; 105 vq->call_ctx.producer.irq = irq; 106 ret = irq_bypass_register_producer(&vq->call_ctx.producer); 107 if (unlikely(ret)) 108 dev_info(&v->dev, "vq %u, irq bypass producer (token %p) registration fails, ret = %d\n", 109 qid, vq->call_ctx.producer.token, ret); 110 } 111 112 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid) 113 { 114 struct vhost_virtqueue *vq = &v->vqs[qid]; 115 116 irq_bypass_unregister_producer(&vq->call_ctx.producer); 117 } 118 119 static void vhost_vdpa_reset(struct vhost_vdpa *v) 120 { 121 struct vdpa_device *vdpa = v->vdpa; 122 123 vdpa_reset(vdpa); 124 v->in_batch = 0; 125 } 126 127 static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp) 128 { 129 struct vdpa_device *vdpa = v->vdpa; 130 const struct vdpa_config_ops *ops = vdpa->config; 131 u32 device_id; 132 133 device_id = ops->get_device_id(vdpa); 134 135 if (copy_to_user(argp, &device_id, sizeof(device_id))) 136 return -EFAULT; 137 138 return 0; 139 } 140 141 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp) 142 { 143 struct vdpa_device *vdpa = v->vdpa; 144 const struct vdpa_config_ops *ops = vdpa->config; 145 u8 status; 146 147 status = ops->get_status(vdpa); 148 149 if (copy_to_user(statusp, &status, sizeof(status))) 150 return -EFAULT; 151 152 return 0; 153 } 154 155 static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp) 156 { 157 struct vdpa_device *vdpa = v->vdpa; 158 const struct vdpa_config_ops *ops = vdpa->config; 159 u8 status, status_old; 160 int nvqs = v->nvqs; 161 u16 i; 162 163 if (copy_from_user(&status, statusp, sizeof(status))) 164 return -EFAULT; 165 166 status_old = ops->get_status(vdpa); 167 168 /* 169 * Userspace shouldn't remove status bits unless reset the 170 * status to 0. 171 */ 172 if (status != 0 && (ops->get_status(vdpa) & ~status) != 0) 173 return -EINVAL; 174 175 ops->set_status(vdpa, status); 176 177 if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK)) 178 for (i = 0; i < nvqs; i++) 179 vhost_vdpa_setup_vq_irq(v, i); 180 181 if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK)) 182 for (i = 0; i < nvqs; i++) 183 vhost_vdpa_unsetup_vq_irq(v, i); 184 185 return 0; 186 } 187 188 static int vhost_vdpa_config_validate(struct vhost_vdpa *v, 189 struct vhost_vdpa_config *c) 190 { 191 struct vdpa_device *vdpa = v->vdpa; 192 long size = vdpa->config->get_config_size(vdpa); 193 194 if (c->len == 0) 195 return -EINVAL; 196 197 if (c->len > size - c->off) 198 return -E2BIG; 199 200 return 0; 201 } 202 203 static long vhost_vdpa_get_config(struct vhost_vdpa *v, 204 struct vhost_vdpa_config __user *c) 205 { 206 struct vdpa_device *vdpa = v->vdpa; 207 struct vhost_vdpa_config config; 208 unsigned long size = offsetof(struct vhost_vdpa_config, buf); 209 u8 *buf; 210 211 if (copy_from_user(&config, c, size)) 212 return -EFAULT; 213 if (vhost_vdpa_config_validate(v, &config)) 214 return -EINVAL; 215 buf = kvzalloc(config.len, GFP_KERNEL); 216 if (!buf) 217 return -ENOMEM; 218 219 vdpa_get_config(vdpa, config.off, buf, config.len); 220 221 if (copy_to_user(c->buf, buf, config.len)) { 222 kvfree(buf); 223 return -EFAULT; 224 } 225 226 kvfree(buf); 227 return 0; 228 } 229 230 static long vhost_vdpa_set_config(struct vhost_vdpa *v, 231 struct vhost_vdpa_config __user *c) 232 { 233 struct vdpa_device *vdpa = v->vdpa; 234 const struct vdpa_config_ops *ops = vdpa->config; 235 struct vhost_vdpa_config config; 236 unsigned long size = offsetof(struct vhost_vdpa_config, buf); 237 u8 *buf; 238 239 if (copy_from_user(&config, c, size)) 240 return -EFAULT; 241 if (vhost_vdpa_config_validate(v, &config)) 242 return -EINVAL; 243 244 buf = vmemdup_user(c->buf, config.len); 245 if (IS_ERR(buf)) 246 return PTR_ERR(buf); 247 248 ops->set_config(vdpa, config.off, buf, config.len); 249 250 kvfree(buf); 251 return 0; 252 } 253 254 static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep) 255 { 256 struct vdpa_device *vdpa = v->vdpa; 257 const struct vdpa_config_ops *ops = vdpa->config; 258 u64 features; 259 260 features = ops->get_features(vdpa); 261 262 if (copy_to_user(featurep, &features, sizeof(features))) 263 return -EFAULT; 264 265 return 0; 266 } 267 268 static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep) 269 { 270 struct vdpa_device *vdpa = v->vdpa; 271 const struct vdpa_config_ops *ops = vdpa->config; 272 u64 features; 273 274 /* 275 * It's not allowed to change the features after they have 276 * been negotiated. 277 */ 278 if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK) 279 return -EBUSY; 280 281 if (copy_from_user(&features, featurep, sizeof(features))) 282 return -EFAULT; 283 284 if (vdpa_set_features(vdpa, features)) 285 return -EINVAL; 286 287 return 0; 288 } 289 290 static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp) 291 { 292 struct vdpa_device *vdpa = v->vdpa; 293 const struct vdpa_config_ops *ops = vdpa->config; 294 u16 num; 295 296 num = ops->get_vq_num_max(vdpa); 297 298 if (copy_to_user(argp, &num, sizeof(num))) 299 return -EFAULT; 300 301 return 0; 302 } 303 304 static void vhost_vdpa_config_put(struct vhost_vdpa *v) 305 { 306 if (v->config_ctx) { 307 eventfd_ctx_put(v->config_ctx); 308 v->config_ctx = NULL; 309 } 310 } 311 312 static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp) 313 { 314 struct vdpa_callback cb; 315 int fd; 316 struct eventfd_ctx *ctx; 317 318 cb.callback = vhost_vdpa_config_cb; 319 cb.private = v->vdpa; 320 if (copy_from_user(&fd, argp, sizeof(fd))) 321 return -EFAULT; 322 323 ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd); 324 swap(ctx, v->config_ctx); 325 326 if (!IS_ERR_OR_NULL(ctx)) 327 eventfd_ctx_put(ctx); 328 329 if (IS_ERR(v->config_ctx)) { 330 long ret = PTR_ERR(v->config_ctx); 331 332 v->config_ctx = NULL; 333 return ret; 334 } 335 336 v->vdpa->config->set_config_cb(v->vdpa, &cb); 337 338 return 0; 339 } 340 341 static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp) 342 { 343 struct vhost_vdpa_iova_range range = { 344 .first = v->range.first, 345 .last = v->range.last, 346 }; 347 348 if (copy_to_user(argp, &range, sizeof(range))) 349 return -EFAULT; 350 return 0; 351 } 352 353 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, 354 void __user *argp) 355 { 356 struct vdpa_device *vdpa = v->vdpa; 357 const struct vdpa_config_ops *ops = vdpa->config; 358 struct vdpa_vq_state vq_state; 359 struct vdpa_callback cb; 360 struct vhost_virtqueue *vq; 361 struct vhost_vring_state s; 362 u32 idx; 363 long r; 364 365 r = get_user(idx, (u32 __user *)argp); 366 if (r < 0) 367 return r; 368 369 if (idx >= v->nvqs) 370 return -ENOBUFS; 371 372 idx = array_index_nospec(idx, v->nvqs); 373 vq = &v->vqs[idx]; 374 375 switch (cmd) { 376 case VHOST_VDPA_SET_VRING_ENABLE: 377 if (copy_from_user(&s, argp, sizeof(s))) 378 return -EFAULT; 379 ops->set_vq_ready(vdpa, idx, s.num); 380 return 0; 381 case VHOST_GET_VRING_BASE: 382 r = ops->get_vq_state(v->vdpa, idx, &vq_state); 383 if (r) 384 return r; 385 386 vq->last_avail_idx = vq_state.split.avail_index; 387 break; 388 } 389 390 r = vhost_vring_ioctl(&v->vdev, cmd, argp); 391 if (r) 392 return r; 393 394 switch (cmd) { 395 case VHOST_SET_VRING_ADDR: 396 if (ops->set_vq_address(vdpa, idx, 397 (u64)(uintptr_t)vq->desc, 398 (u64)(uintptr_t)vq->avail, 399 (u64)(uintptr_t)vq->used)) 400 r = -EINVAL; 401 break; 402 403 case VHOST_SET_VRING_BASE: 404 vq_state.split.avail_index = vq->last_avail_idx; 405 if (ops->set_vq_state(vdpa, idx, &vq_state)) 406 r = -EINVAL; 407 break; 408 409 case VHOST_SET_VRING_CALL: 410 if (vq->call_ctx.ctx) { 411 cb.callback = vhost_vdpa_virtqueue_cb; 412 cb.private = vq; 413 } else { 414 cb.callback = NULL; 415 cb.private = NULL; 416 } 417 ops->set_vq_cb(vdpa, idx, &cb); 418 vhost_vdpa_setup_vq_irq(v, idx); 419 break; 420 421 case VHOST_SET_VRING_NUM: 422 ops->set_vq_num(vdpa, idx, vq->num); 423 break; 424 } 425 426 return r; 427 } 428 429 static long vhost_vdpa_unlocked_ioctl(struct file *filep, 430 unsigned int cmd, unsigned long arg) 431 { 432 struct vhost_vdpa *v = filep->private_data; 433 struct vhost_dev *d = &v->vdev; 434 void __user *argp = (void __user *)arg; 435 u64 __user *featurep = argp; 436 u64 features; 437 long r = 0; 438 439 if (cmd == VHOST_SET_BACKEND_FEATURES) { 440 if (copy_from_user(&features, featurep, sizeof(features))) 441 return -EFAULT; 442 if (features & ~VHOST_VDPA_BACKEND_FEATURES) 443 return -EOPNOTSUPP; 444 vhost_set_backend_features(&v->vdev, features); 445 return 0; 446 } 447 448 mutex_lock(&d->mutex); 449 450 switch (cmd) { 451 case VHOST_VDPA_GET_DEVICE_ID: 452 r = vhost_vdpa_get_device_id(v, argp); 453 break; 454 case VHOST_VDPA_GET_STATUS: 455 r = vhost_vdpa_get_status(v, argp); 456 break; 457 case VHOST_VDPA_SET_STATUS: 458 r = vhost_vdpa_set_status(v, argp); 459 break; 460 case VHOST_VDPA_GET_CONFIG: 461 r = vhost_vdpa_get_config(v, argp); 462 break; 463 case VHOST_VDPA_SET_CONFIG: 464 r = vhost_vdpa_set_config(v, argp); 465 break; 466 case VHOST_GET_FEATURES: 467 r = vhost_vdpa_get_features(v, argp); 468 break; 469 case VHOST_SET_FEATURES: 470 r = vhost_vdpa_set_features(v, argp); 471 break; 472 case VHOST_VDPA_GET_VRING_NUM: 473 r = vhost_vdpa_get_vring_num(v, argp); 474 break; 475 case VHOST_SET_LOG_BASE: 476 case VHOST_SET_LOG_FD: 477 r = -ENOIOCTLCMD; 478 break; 479 case VHOST_VDPA_SET_CONFIG_CALL: 480 r = vhost_vdpa_set_config_call(v, argp); 481 break; 482 case VHOST_GET_BACKEND_FEATURES: 483 features = VHOST_VDPA_BACKEND_FEATURES; 484 if (copy_to_user(featurep, &features, sizeof(features))) 485 r = -EFAULT; 486 break; 487 case VHOST_VDPA_GET_IOVA_RANGE: 488 r = vhost_vdpa_get_iova_range(v, argp); 489 break; 490 default: 491 r = vhost_dev_ioctl(&v->vdev, cmd, argp); 492 if (r == -ENOIOCTLCMD) 493 r = vhost_vdpa_vring_ioctl(v, cmd, argp); 494 break; 495 } 496 497 mutex_unlock(&d->mutex); 498 return r; 499 } 500 501 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last) 502 { 503 struct vhost_dev *dev = &v->vdev; 504 struct vhost_iotlb *iotlb = dev->iotlb; 505 struct vhost_iotlb_map *map; 506 struct page *page; 507 unsigned long pfn, pinned; 508 509 while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) { 510 pinned = map->size >> PAGE_SHIFT; 511 for (pfn = map->addr >> PAGE_SHIFT; 512 pinned > 0; pfn++, pinned--) { 513 page = pfn_to_page(pfn); 514 if (map->perm & VHOST_ACCESS_WO) 515 set_page_dirty_lock(page); 516 unpin_user_page(page); 517 } 518 atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm); 519 vhost_iotlb_map_free(iotlb, map); 520 } 521 } 522 523 static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v) 524 { 525 struct vhost_dev *dev = &v->vdev; 526 527 vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1); 528 kfree(dev->iotlb); 529 dev->iotlb = NULL; 530 } 531 532 static int perm_to_iommu_flags(u32 perm) 533 { 534 int flags = 0; 535 536 switch (perm) { 537 case VHOST_ACCESS_WO: 538 flags |= IOMMU_WRITE; 539 break; 540 case VHOST_ACCESS_RO: 541 flags |= IOMMU_READ; 542 break; 543 case VHOST_ACCESS_RW: 544 flags |= (IOMMU_WRITE | IOMMU_READ); 545 break; 546 default: 547 WARN(1, "invalidate vhost IOTLB permission\n"); 548 break; 549 } 550 551 return flags | IOMMU_CACHE; 552 } 553 554 static int vhost_vdpa_map(struct vhost_vdpa *v, 555 u64 iova, u64 size, u64 pa, u32 perm) 556 { 557 struct vhost_dev *dev = &v->vdev; 558 struct vdpa_device *vdpa = v->vdpa; 559 const struct vdpa_config_ops *ops = vdpa->config; 560 int r = 0; 561 562 r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1, 563 pa, perm); 564 if (r) 565 return r; 566 567 if (ops->dma_map) { 568 r = ops->dma_map(vdpa, iova, size, pa, perm); 569 } else if (ops->set_map) { 570 if (!v->in_batch) 571 r = ops->set_map(vdpa, dev->iotlb); 572 } else { 573 r = iommu_map(v->domain, iova, pa, size, 574 perm_to_iommu_flags(perm)); 575 } 576 577 if (r) 578 vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1); 579 else 580 atomic64_add(size >> PAGE_SHIFT, &dev->mm->pinned_vm); 581 582 return r; 583 } 584 585 static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size) 586 { 587 struct vhost_dev *dev = &v->vdev; 588 struct vdpa_device *vdpa = v->vdpa; 589 const struct vdpa_config_ops *ops = vdpa->config; 590 591 vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1); 592 593 if (ops->dma_map) { 594 ops->dma_unmap(vdpa, iova, size); 595 } else if (ops->set_map) { 596 if (!v->in_batch) 597 ops->set_map(vdpa, dev->iotlb); 598 } else { 599 iommu_unmap(v->domain, iova, size); 600 } 601 } 602 603 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v, 604 struct vhost_iotlb_msg *msg) 605 { 606 struct vhost_dev *dev = &v->vdev; 607 struct vhost_iotlb *iotlb = dev->iotlb; 608 struct page **page_list; 609 unsigned long list_size = PAGE_SIZE / sizeof(struct page *); 610 unsigned int gup_flags = FOLL_LONGTERM; 611 unsigned long npages, cur_base, map_pfn, last_pfn = 0; 612 unsigned long lock_limit, sz2pin, nchunks, i; 613 u64 iova = msg->iova; 614 long pinned; 615 int ret = 0; 616 617 if (msg->iova < v->range.first || 618 msg->iova + msg->size - 1 > v->range.last) 619 return -EINVAL; 620 621 if (vhost_iotlb_itree_first(iotlb, msg->iova, 622 msg->iova + msg->size - 1)) 623 return -EEXIST; 624 625 /* Limit the use of memory for bookkeeping */ 626 page_list = (struct page **) __get_free_page(GFP_KERNEL); 627 if (!page_list) 628 return -ENOMEM; 629 630 if (msg->perm & VHOST_ACCESS_WO) 631 gup_flags |= FOLL_WRITE; 632 633 npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT; 634 if (!npages) { 635 ret = -EINVAL; 636 goto free; 637 } 638 639 mmap_read_lock(dev->mm); 640 641 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 642 if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) { 643 ret = -ENOMEM; 644 goto unlock; 645 } 646 647 cur_base = msg->uaddr & PAGE_MASK; 648 iova &= PAGE_MASK; 649 nchunks = 0; 650 651 while (npages) { 652 sz2pin = min_t(unsigned long, npages, list_size); 653 pinned = pin_user_pages(cur_base, sz2pin, 654 gup_flags, page_list, NULL); 655 if (sz2pin != pinned) { 656 if (pinned < 0) { 657 ret = pinned; 658 } else { 659 unpin_user_pages(page_list, pinned); 660 ret = -ENOMEM; 661 } 662 goto out; 663 } 664 nchunks++; 665 666 if (!last_pfn) 667 map_pfn = page_to_pfn(page_list[0]); 668 669 for (i = 0; i < pinned; i++) { 670 unsigned long this_pfn = page_to_pfn(page_list[i]); 671 u64 csize; 672 673 if (last_pfn && (this_pfn != last_pfn + 1)) { 674 /* Pin a contiguous chunk of memory */ 675 csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT; 676 ret = vhost_vdpa_map(v, iova, csize, 677 map_pfn << PAGE_SHIFT, 678 msg->perm); 679 if (ret) { 680 /* 681 * Unpin the pages that are left unmapped 682 * from this point on in the current 683 * page_list. The remaining outstanding 684 * ones which may stride across several 685 * chunks will be covered in the common 686 * error path subsequently. 687 */ 688 unpin_user_pages(&page_list[i], 689 pinned - i); 690 goto out; 691 } 692 693 map_pfn = this_pfn; 694 iova += csize; 695 nchunks = 0; 696 } 697 698 last_pfn = this_pfn; 699 } 700 701 cur_base += pinned << PAGE_SHIFT; 702 npages -= pinned; 703 } 704 705 /* Pin the rest chunk */ 706 ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT, 707 map_pfn << PAGE_SHIFT, msg->perm); 708 out: 709 if (ret) { 710 if (nchunks) { 711 unsigned long pfn; 712 713 /* 714 * Unpin the outstanding pages which are yet to be 715 * mapped but haven't due to vdpa_map() or 716 * pin_user_pages() failure. 717 * 718 * Mapped pages are accounted in vdpa_map(), hence 719 * the corresponding unpinning will be handled by 720 * vdpa_unmap(). 721 */ 722 WARN_ON(!last_pfn); 723 for (pfn = map_pfn; pfn <= last_pfn; pfn++) 724 unpin_user_page(pfn_to_page(pfn)); 725 } 726 vhost_vdpa_unmap(v, msg->iova, msg->size); 727 } 728 unlock: 729 mmap_read_unlock(dev->mm); 730 free: 731 free_page((unsigned long)page_list); 732 return ret; 733 } 734 735 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, 736 struct vhost_iotlb_msg *msg) 737 { 738 struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev); 739 struct vdpa_device *vdpa = v->vdpa; 740 const struct vdpa_config_ops *ops = vdpa->config; 741 int r = 0; 742 743 mutex_lock(&dev->mutex); 744 745 r = vhost_dev_check_owner(dev); 746 if (r) 747 goto unlock; 748 749 switch (msg->type) { 750 case VHOST_IOTLB_UPDATE: 751 r = vhost_vdpa_process_iotlb_update(v, msg); 752 break; 753 case VHOST_IOTLB_INVALIDATE: 754 vhost_vdpa_unmap(v, msg->iova, msg->size); 755 break; 756 case VHOST_IOTLB_BATCH_BEGIN: 757 v->in_batch = true; 758 break; 759 case VHOST_IOTLB_BATCH_END: 760 if (v->in_batch && ops->set_map) 761 ops->set_map(vdpa, dev->iotlb); 762 v->in_batch = false; 763 break; 764 default: 765 r = -EINVAL; 766 break; 767 } 768 unlock: 769 mutex_unlock(&dev->mutex); 770 771 return r; 772 } 773 774 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb, 775 struct iov_iter *from) 776 { 777 struct file *file = iocb->ki_filp; 778 struct vhost_vdpa *v = file->private_data; 779 struct vhost_dev *dev = &v->vdev; 780 781 return vhost_chr_write_iter(dev, from); 782 } 783 784 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v) 785 { 786 struct vdpa_device *vdpa = v->vdpa; 787 const struct vdpa_config_ops *ops = vdpa->config; 788 struct device *dma_dev = vdpa_get_dma_dev(vdpa); 789 struct bus_type *bus; 790 int ret; 791 792 /* Device want to do DMA by itself */ 793 if (ops->set_map || ops->dma_map) 794 return 0; 795 796 bus = dma_dev->bus; 797 if (!bus) 798 return -EFAULT; 799 800 if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY)) 801 return -ENOTSUPP; 802 803 v->domain = iommu_domain_alloc(bus); 804 if (!v->domain) 805 return -EIO; 806 807 ret = iommu_attach_device(v->domain, dma_dev); 808 if (ret) 809 goto err_attach; 810 811 return 0; 812 813 err_attach: 814 iommu_domain_free(v->domain); 815 return ret; 816 } 817 818 static void vhost_vdpa_free_domain(struct vhost_vdpa *v) 819 { 820 struct vdpa_device *vdpa = v->vdpa; 821 struct device *dma_dev = vdpa_get_dma_dev(vdpa); 822 823 if (v->domain) { 824 iommu_detach_device(v->domain, dma_dev); 825 iommu_domain_free(v->domain); 826 } 827 828 v->domain = NULL; 829 } 830 831 static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v) 832 { 833 struct vdpa_iova_range *range = &v->range; 834 struct vdpa_device *vdpa = v->vdpa; 835 const struct vdpa_config_ops *ops = vdpa->config; 836 837 if (ops->get_iova_range) { 838 *range = ops->get_iova_range(vdpa); 839 } else if (v->domain && v->domain->geometry.force_aperture) { 840 range->first = v->domain->geometry.aperture_start; 841 range->last = v->domain->geometry.aperture_end; 842 } else { 843 range->first = 0; 844 range->last = ULLONG_MAX; 845 } 846 } 847 848 static int vhost_vdpa_open(struct inode *inode, struct file *filep) 849 { 850 struct vhost_vdpa *v; 851 struct vhost_dev *dev; 852 struct vhost_virtqueue **vqs; 853 int nvqs, i, r, opened; 854 855 v = container_of(inode->i_cdev, struct vhost_vdpa, cdev); 856 857 opened = atomic_cmpxchg(&v->opened, 0, 1); 858 if (opened) 859 return -EBUSY; 860 861 nvqs = v->nvqs; 862 vhost_vdpa_reset(v); 863 864 vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL); 865 if (!vqs) { 866 r = -ENOMEM; 867 goto err; 868 } 869 870 dev = &v->vdev; 871 for (i = 0; i < nvqs; i++) { 872 vqs[i] = &v->vqs[i]; 873 vqs[i]->handle_kick = handle_vq_kick; 874 } 875 vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false, 876 vhost_vdpa_process_iotlb_msg); 877 878 dev->iotlb = vhost_iotlb_alloc(0, 0); 879 if (!dev->iotlb) { 880 r = -ENOMEM; 881 goto err_init_iotlb; 882 } 883 884 r = vhost_vdpa_alloc_domain(v); 885 if (r) 886 goto err_init_iotlb; 887 888 vhost_vdpa_set_iova_range(v); 889 890 filep->private_data = v; 891 892 return 0; 893 894 err_init_iotlb: 895 vhost_dev_cleanup(&v->vdev); 896 kfree(vqs); 897 err: 898 atomic_dec(&v->opened); 899 return r; 900 } 901 902 static void vhost_vdpa_clean_irq(struct vhost_vdpa *v) 903 { 904 int i; 905 906 for (i = 0; i < v->nvqs; i++) 907 vhost_vdpa_unsetup_vq_irq(v, i); 908 } 909 910 static int vhost_vdpa_release(struct inode *inode, struct file *filep) 911 { 912 struct vhost_vdpa *v = filep->private_data; 913 struct vhost_dev *d = &v->vdev; 914 915 mutex_lock(&d->mutex); 916 filep->private_data = NULL; 917 vhost_vdpa_reset(v); 918 vhost_dev_stop(&v->vdev); 919 vhost_vdpa_iotlb_free(v); 920 vhost_vdpa_free_domain(v); 921 vhost_vdpa_config_put(v); 922 vhost_vdpa_clean_irq(v); 923 vhost_dev_cleanup(&v->vdev); 924 kfree(v->vdev.vqs); 925 mutex_unlock(&d->mutex); 926 927 atomic_dec(&v->opened); 928 complete(&v->completion); 929 930 return 0; 931 } 932 933 #ifdef CONFIG_MMU 934 static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf) 935 { 936 struct vhost_vdpa *v = vmf->vma->vm_file->private_data; 937 struct vdpa_device *vdpa = v->vdpa; 938 const struct vdpa_config_ops *ops = vdpa->config; 939 struct vdpa_notification_area notify; 940 struct vm_area_struct *vma = vmf->vma; 941 u16 index = vma->vm_pgoff; 942 943 notify = ops->get_vq_notification(vdpa, index); 944 945 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 946 if (remap_pfn_range(vma, vmf->address & PAGE_MASK, 947 notify.addr >> PAGE_SHIFT, PAGE_SIZE, 948 vma->vm_page_prot)) 949 return VM_FAULT_SIGBUS; 950 951 return VM_FAULT_NOPAGE; 952 } 953 954 static const struct vm_operations_struct vhost_vdpa_vm_ops = { 955 .fault = vhost_vdpa_fault, 956 }; 957 958 static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma) 959 { 960 struct vhost_vdpa *v = vma->vm_file->private_data; 961 struct vdpa_device *vdpa = v->vdpa; 962 const struct vdpa_config_ops *ops = vdpa->config; 963 struct vdpa_notification_area notify; 964 unsigned long index = vma->vm_pgoff; 965 966 if (vma->vm_end - vma->vm_start != PAGE_SIZE) 967 return -EINVAL; 968 if ((vma->vm_flags & VM_SHARED) == 0) 969 return -EINVAL; 970 if (vma->vm_flags & VM_READ) 971 return -EINVAL; 972 if (index > 65535) 973 return -EINVAL; 974 if (!ops->get_vq_notification) 975 return -ENOTSUPP; 976 977 /* To be safe and easily modelled by userspace, We only 978 * support the doorbell which sits on the page boundary and 979 * does not share the page with other registers. 980 */ 981 notify = ops->get_vq_notification(vdpa, index); 982 if (notify.addr & (PAGE_SIZE - 1)) 983 return -EINVAL; 984 if (vma->vm_end - vma->vm_start != notify.size) 985 return -ENOTSUPP; 986 987 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 988 vma->vm_ops = &vhost_vdpa_vm_ops; 989 return 0; 990 } 991 #endif /* CONFIG_MMU */ 992 993 static const struct file_operations vhost_vdpa_fops = { 994 .owner = THIS_MODULE, 995 .open = vhost_vdpa_open, 996 .release = vhost_vdpa_release, 997 .write_iter = vhost_vdpa_chr_write_iter, 998 .unlocked_ioctl = vhost_vdpa_unlocked_ioctl, 999 #ifdef CONFIG_MMU 1000 .mmap = vhost_vdpa_mmap, 1001 #endif /* CONFIG_MMU */ 1002 .compat_ioctl = compat_ptr_ioctl, 1003 }; 1004 1005 static void vhost_vdpa_release_dev(struct device *device) 1006 { 1007 struct vhost_vdpa *v = 1008 container_of(device, struct vhost_vdpa, dev); 1009 1010 ida_simple_remove(&vhost_vdpa_ida, v->minor); 1011 kfree(v->vqs); 1012 kfree(v); 1013 } 1014 1015 static int vhost_vdpa_probe(struct vdpa_device *vdpa) 1016 { 1017 const struct vdpa_config_ops *ops = vdpa->config; 1018 struct vhost_vdpa *v; 1019 int minor; 1020 int r; 1021 1022 v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL); 1023 if (!v) 1024 return -ENOMEM; 1025 1026 minor = ida_simple_get(&vhost_vdpa_ida, 0, 1027 VHOST_VDPA_DEV_MAX, GFP_KERNEL); 1028 if (minor < 0) { 1029 kfree(v); 1030 return minor; 1031 } 1032 1033 atomic_set(&v->opened, 0); 1034 v->minor = minor; 1035 v->vdpa = vdpa; 1036 v->nvqs = vdpa->nvqs; 1037 v->virtio_id = ops->get_device_id(vdpa); 1038 1039 device_initialize(&v->dev); 1040 v->dev.release = vhost_vdpa_release_dev; 1041 v->dev.parent = &vdpa->dev; 1042 v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor); 1043 v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue), 1044 GFP_KERNEL); 1045 if (!v->vqs) { 1046 r = -ENOMEM; 1047 goto err; 1048 } 1049 1050 r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor); 1051 if (r) 1052 goto err; 1053 1054 cdev_init(&v->cdev, &vhost_vdpa_fops); 1055 v->cdev.owner = THIS_MODULE; 1056 1057 r = cdev_device_add(&v->cdev, &v->dev); 1058 if (r) 1059 goto err; 1060 1061 init_completion(&v->completion); 1062 vdpa_set_drvdata(vdpa, v); 1063 1064 return 0; 1065 1066 err: 1067 put_device(&v->dev); 1068 return r; 1069 } 1070 1071 static void vhost_vdpa_remove(struct vdpa_device *vdpa) 1072 { 1073 struct vhost_vdpa *v = vdpa_get_drvdata(vdpa); 1074 int opened; 1075 1076 cdev_device_del(&v->cdev, &v->dev); 1077 1078 do { 1079 opened = atomic_cmpxchg(&v->opened, 0, 1); 1080 if (!opened) 1081 break; 1082 wait_for_completion(&v->completion); 1083 } while (1); 1084 1085 put_device(&v->dev); 1086 } 1087 1088 static struct vdpa_driver vhost_vdpa_driver = { 1089 .driver = { 1090 .name = "vhost_vdpa", 1091 }, 1092 .probe = vhost_vdpa_probe, 1093 .remove = vhost_vdpa_remove, 1094 }; 1095 1096 static int __init vhost_vdpa_init(void) 1097 { 1098 int r; 1099 1100 r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX, 1101 "vhost-vdpa"); 1102 if (r) 1103 goto err_alloc_chrdev; 1104 1105 r = vdpa_register_driver(&vhost_vdpa_driver); 1106 if (r) 1107 goto err_vdpa_register_driver; 1108 1109 return 0; 1110 1111 err_vdpa_register_driver: 1112 unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX); 1113 err_alloc_chrdev: 1114 return r; 1115 } 1116 module_init(vhost_vdpa_init); 1117 1118 static void __exit vhost_vdpa_exit(void) 1119 { 1120 vdpa_unregister_driver(&vhost_vdpa_driver); 1121 unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX); 1122 } 1123 module_exit(vhost_vdpa_exit); 1124 1125 MODULE_VERSION("0.0.1"); 1126 MODULE_LICENSE("GPL v2"); 1127 MODULE_AUTHOR("Intel Corporation"); 1128 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio"); 1129