drivers/vhost/vdpa.c

   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/iommu.h>
  19 #include <linux/uuid.h>
  20 #include <linux/vdpa.h>
  21 #include <linux/nospec.h>
  22 #include <linux/vhost.h>
  23 #include <linux/virtio_net.h>
  24
  25 #include "vhost.h"
  26
  27 enum {
  28         VHOST_VDPA_FEATURES =
  29                 (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
  30                 (1ULL << VIRTIO_F_ANY_LAYOUT) |
  31                 (1ULL << VIRTIO_F_VERSION_1) |
  32                 (1ULL << VIRTIO_F_IOMMU_PLATFORM) |
  33                 (1ULL << VIRTIO_F_RING_PACKED) |
  34                 (1ULL << VIRTIO_F_ORDER_PLATFORM) |
  35                 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
  36                 (1ULL << VIRTIO_RING_F_EVENT_IDX),
  37
  38         VHOST_VDPA_NET_FEATURES = VHOST_VDPA_FEATURES |
  39                 (1ULL << VIRTIO_NET_F_CSUM) |
  40                 (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
  41                 (1ULL << VIRTIO_NET_F_MTU) |
  42                 (1ULL << VIRTIO_NET_F_MAC) |
  43                 (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
  44                 (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
  45                 (1ULL << VIRTIO_NET_F_GUEST_ECN) |
  46                 (1ULL << VIRTIO_NET_F_GUEST_UFO) |
  47                 (1ULL << VIRTIO_NET_F_HOST_TSO4) |
  48                 (1ULL << VIRTIO_NET_F_HOST_TSO6) |
  49                 (1ULL << VIRTIO_NET_F_HOST_ECN) |
  50                 (1ULL << VIRTIO_NET_F_HOST_UFO) |
  51                 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
  52                 (1ULL << VIRTIO_NET_F_STATUS) |
  53                 (1ULL << VIRTIO_NET_F_SPEED_DUPLEX),
  54 };
  55
  56 /* Currently, only network backend w/o multiqueue is supported. */
  57 #define VHOST_VDPA_VQ_MAX       2
  58
  59 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
  60
  61 struct vhost_vdpa {
  62         struct vhost_dev vdev;
  63         struct iommu_domain *domain;
  64         struct vhost_virtqueue *vqs;
  65         struct completion completion;
  66         struct vdpa_device *vdpa;
  67         struct device dev;
  68         struct cdev cdev;
  69         atomic_t opened;
  70         int nvqs;
  71         int virtio_id;
  72         int minor;
  73 };
  74
  75 static DEFINE_IDA(vhost_vdpa_ida);
  76
  77 static dev_t vhost_vdpa_major;
  78
  79 static const u64 vhost_vdpa_features[] = {
  80         [VIRTIO_ID_NET] = VHOST_VDPA_NET_FEATURES,
  81 };
  82
  83 static void handle_vq_kick(struct vhost_work *work)
  84 {
  85         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
  86                                                   poll.work);
  87         struct vhost_vdpa *v = container_of(vq->dev, struct vhost_vdpa, vdev);
  88         const struct vdpa_config_ops *ops = v->vdpa->config;
  89
  90         ops->kick_vq(v->vdpa, vq - v->vqs);
  91 }
  92
  93 static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
  94 {
  95         struct vhost_virtqueue *vq = private;
  96         struct eventfd_ctx *call_ctx = vq->call_ctx;
  97
  98         if (call_ctx)
  99                 eventfd_signal(call_ctx, 1);
 100
 101         return IRQ_HANDLED;
 102 }
 103
 104 static void vhost_vdpa_reset(struct vhost_vdpa *v)
 105 {
 106         struct vdpa_device *vdpa = v->vdpa;
 107         const struct vdpa_config_ops *ops = vdpa->config;
 108
 109         ops->set_status(vdpa, 0);
 110 }
 111
 112 static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
 113 {
 114         struct vdpa_device *vdpa = v->vdpa;
 115         const struct vdpa_config_ops *ops = vdpa->config;
 116         u32 device_id;
 117
 118         device_id = ops->get_device_id(vdpa);
 119
 120         if (copy_to_user(argp, &device_id, sizeof(device_id)))
 121                 return -EFAULT;
 122
 123         return 0;
 124 }
 125
 126 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
 127 {
 128         struct vdpa_device *vdpa = v->vdpa;
 129         const struct vdpa_config_ops *ops = vdpa->config;
 130         u8 status;
 131
 132         status = ops->get_status(vdpa);
 133
 134         if (copy_to_user(statusp, &status, sizeof(status)))
 135                 return -EFAULT;
 136
 137         return 0;
 138 }
 139
 140 static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 141 {
 142         struct vdpa_device *vdpa = v->vdpa;
 143         const struct vdpa_config_ops *ops = vdpa->config;
 144         u8 status;
 145
 146         if (copy_from_user(&status, statusp, sizeof(status)))
 147                 return -EFAULT;
 148
 149         /*
 150          * Userspace shouldn't remove status bits unless reset the
 151          * status to 0.
 152          */
 153         if (status != 0 && (ops->get_status(vdpa) & ~status) != 0)
 154                 return -EINVAL;
 155
 156         ops->set_status(vdpa, status);
 157
 158         return 0;
 159 }
 160
 161 static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
 162                                       struct vhost_vdpa_config *c)
 163 {
 164         long size = 0;
 165
 166         switch (v->virtio_id) {
 167         case VIRTIO_ID_NET:
 168                 size = sizeof(struct virtio_net_config);
 169                 break;
 170         }
 171
 172         if (c->len == 0)
 173                 return -EINVAL;
 174
 175         if (c->len > size - c->off)
 176                 return -E2BIG;
 177
 178         return 0;
 179 }
 180
 181 static long vhost_vdpa_get_config(struct vhost_vdpa *v,
 182                                   struct vhost_vdpa_config __user *c)
 183 {
 184         struct vdpa_device *vdpa = v->vdpa;
 185         const struct vdpa_config_ops *ops = vdpa->config;
 186         struct vhost_vdpa_config config;
 187         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 188         u8 *buf;
 189
 190         if (copy_from_user(&config, c, size))
 191                 return -EFAULT;
 192         if (vhost_vdpa_config_validate(v, &config))
 193                 return -EINVAL;
 194         buf = kvzalloc(config.len, GFP_KERNEL);
 195         if (!buf)
 196                 return -ENOMEM;
 197
 198         ops->get_config(vdpa, config.off, buf, config.len);
 199
 200         if (copy_to_user(c->buf, buf, config.len)) {
 201                 kvfree(buf);
 202                 return -EFAULT;
 203         }
 204
 205         kvfree(buf);
 206         return 0;
 207 }
 208
 209 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
 210                                   struct vhost_vdpa_config __user *c)
 211 {
 212         struct vdpa_device *vdpa = v->vdpa;
 213         const struct vdpa_config_ops *ops = vdpa->config;
 214         struct vhost_vdpa_config config;
 215         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 216         u8 *buf;
 217
 218         if (copy_from_user(&config, c, size))
 219                 return -EFAULT;
 220         if (vhost_vdpa_config_validate(v, &config))
 221                 return -EINVAL;
 222         buf = kvzalloc(config.len, GFP_KERNEL);
 223         if (!buf)
 224                 return -ENOMEM;
 225
 226         if (copy_from_user(buf, c->buf, config.len)) {
 227                 kvfree(buf);
 228                 return -EFAULT;
 229         }
 230
 231         ops->set_config(vdpa, config.off, buf, config.len);
 232
 233         kvfree(buf);
 234         return 0;
 235 }
 236
 237 static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
 238 {
 239         struct vdpa_device *vdpa = v->vdpa;
 240         const struct vdpa_config_ops *ops = vdpa->config;
 241         u64 features;
 242
 243         features = ops->get_features(vdpa);
 244         features &= vhost_vdpa_features[v->virtio_id];
 245
 246         if (copy_to_user(featurep, &features, sizeof(features)))
 247                 return -EFAULT;
 248
 249         return 0;
 250 }
 251
 252 static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
 253 {
 254         struct vdpa_device *vdpa = v->vdpa;
 255         const struct vdpa_config_ops *ops = vdpa->config;
 256         u64 features;
 257
 258         /*
 259          * It's not allowed to change the features after they have
 260          * been negotiated.
 261          */
 262         if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK)
 263                 return -EBUSY;
 264
 265         if (copy_from_user(&features, featurep, sizeof(features)))
 266                 return -EFAULT;
 267
 268         if (features & ~vhost_vdpa_features[v->virtio_id])
 269                 return -EINVAL;
 270
 271         if (ops->set_features(vdpa, features))
 272                 return -EINVAL;
 273
 274         return 0;
 275 }
 276
 277 static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
 278 {
 279         struct vdpa_device *vdpa = v->vdpa;
 280         const struct vdpa_config_ops *ops = vdpa->config;
 281         u16 num;
 282
 283         num = ops->get_vq_num_max(vdpa);
 284
 285         if (copy_to_user(argp, &num, sizeof(num)))
 286                 return -EFAULT;
 287
 288         return 0;
 289 }
 290
 291 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 292                                    void __user *argp)
 293 {
 294         struct vdpa_device *vdpa = v->vdpa;
 295         const struct vdpa_config_ops *ops = vdpa->config;
 296         struct vdpa_callback cb;
 297         struct vhost_virtqueue *vq;
 298         struct vhost_vring_state s;
 299         u8 status;
 300         u32 idx;
 301         long r;
 302
 303         r = get_user(idx, (u32 __user *)argp);
 304         if (r < 0)
 305                 return r;
 306
 307         if (idx >= v->nvqs)
 308                 return -ENOBUFS;
 309
 310         idx = array_index_nospec(idx, v->nvqs);
 311         vq = &v->vqs[idx];
 312
 313         status = ops->get_status(vdpa);
 314
 315         if (cmd == VHOST_VDPA_SET_VRING_ENABLE) {
 316                 if (copy_from_user(&s, argp, sizeof(s)))
 317                         return -EFAULT;
 318                 ops->set_vq_ready(vdpa, idx, s.num);
 319                 return 0;
 320         }
 321
 322         if (cmd == VHOST_GET_VRING_BASE)
 323                 vq->last_avail_idx = ops->get_vq_state(v->vdpa, idx);
 324
 325         r = vhost_vring_ioctl(&v->vdev, cmd, argp);
 326         if (r)
 327                 return r;
 328
 329         switch (cmd) {
 330         case VHOST_SET_VRING_ADDR:
 331                 if (ops->set_vq_address(vdpa, idx,
 332                                         (u64)(uintptr_t)vq->desc,
 333                                         (u64)(uintptr_t)vq->avail,
 334                                         (u64)(uintptr_t)vq->used))
 335                         r = -EINVAL;
 336                 break;
 337
 338         case VHOST_SET_VRING_BASE:
 339                 if (ops->set_vq_state(vdpa, idx, vq->last_avail_idx))
 340                         r = -EINVAL;
 341                 break;
 342
 343         case VHOST_SET_VRING_CALL:
 344                 if (vq->call_ctx) {
 345                         cb.callback = vhost_vdpa_virtqueue_cb;
 346                         cb.private = vq;
 347                 } else {
 348                         cb.callback = NULL;
 349                         cb.private = NULL;
 350                 }
 351                 ops->set_vq_cb(vdpa, idx, &cb);
 352                 break;
 353
 354         case VHOST_SET_VRING_NUM:
 355                 ops->set_vq_num(vdpa, idx, vq->num);
 356                 break;
 357         }
 358
 359         return r;
 360 }
 361
 362 static long vhost_vdpa_unlocked_ioctl(struct file *filep,
 363                                       unsigned int cmd, unsigned long arg)
 364 {
 365         struct vhost_vdpa *v = filep->private_data;
 366         struct vhost_dev *d = &v->vdev;
 367         void __user *argp = (void __user *)arg;
 368         long r;
 369
 370         mutex_lock(&d->mutex);
 371
 372         switch (cmd) {
 373         case VHOST_VDPA_GET_DEVICE_ID:
 374                 r = vhost_vdpa_get_device_id(v, argp);
 375                 break;
 376         case VHOST_VDPA_GET_STATUS:
 377                 r = vhost_vdpa_get_status(v, argp);
 378                 break;
 379         case VHOST_VDPA_SET_STATUS:
 380                 r = vhost_vdpa_set_status(v, argp);
 381                 break;
 382         case VHOST_VDPA_GET_CONFIG:
 383                 r = vhost_vdpa_get_config(v, argp);
 384                 break;
 385         case VHOST_VDPA_SET_CONFIG:
 386                 r = vhost_vdpa_set_config(v, argp);
 387                 break;
 388         case VHOST_GET_FEATURES:
 389                 r = vhost_vdpa_get_features(v, argp);
 390                 break;
 391         case VHOST_SET_FEATURES:
 392                 r = vhost_vdpa_set_features(v, argp);
 393                 break;
 394         case VHOST_VDPA_GET_VRING_NUM:
 395                 r = vhost_vdpa_get_vring_num(v, argp);
 396                 break;
 397         case VHOST_SET_LOG_BASE:
 398         case VHOST_SET_LOG_FD:
 399                 r = -ENOIOCTLCMD;
 400                 break;
 401         default:
 402                 r = vhost_dev_ioctl(&v->vdev, cmd, argp);
 403                 if (r == -ENOIOCTLCMD)
 404                         r = vhost_vdpa_vring_ioctl(v, cmd, argp);
 405                 break;
 406         }
 407
 408         mutex_unlock(&d->mutex);
 409         return r;
 410 }
 411
 412 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 413 {
 414         struct vhost_dev *dev = &v->vdev;
 415         struct vhost_iotlb *iotlb = dev->iotlb;
 416         struct vhost_iotlb_map *map;
 417         struct page *page;
 418         unsigned long pfn, pinned;
 419
 420         while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
 421                 pinned = map->size >> PAGE_SHIFT;
 422                 for (pfn = map->addr >> PAGE_SHIFT;
 423                      pinned > 0; pfn++, pinned--) {
 424                         page = pfn_to_page(pfn);
 425                         if (map->perm & VHOST_ACCESS_WO)
 426                                 set_page_dirty_lock(page);
 427                         unpin_user_page(page);
 428                 }
 429                 atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm);
 430                 vhost_iotlb_map_free(iotlb, map);
 431         }
 432 }
 433
 434 static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
 435 {
 436         struct vhost_dev *dev = &v->vdev;
 437
 438         vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
 439         kfree(dev->iotlb);
 440         dev->iotlb = NULL;
 441 }
 442
 443 static int perm_to_iommu_flags(u32 perm)
 444 {
 445         int flags = 0;
 446
 447         switch (perm) {
 448         case VHOST_ACCESS_WO:
 449                 flags |= IOMMU_WRITE;
 450                 break;
 451         case VHOST_ACCESS_RO:
 452                 flags |= IOMMU_READ;
 453                 break;
 454         case VHOST_ACCESS_RW:
 455                 flags |= (IOMMU_WRITE | IOMMU_READ);
 456                 break;
 457         default:
 458                 WARN(1, "invalidate vhost IOTLB permission\n");
 459                 break;
 460         }
 461
 462         return flags | IOMMU_CACHE;
 463 }
 464
 465 static int vhost_vdpa_map(struct vhost_vdpa *v,
 466                           u64 iova, u64 size, u64 pa, u32 perm)
 467 {
 468         struct vhost_dev *dev = &v->vdev;
 469         struct vdpa_device *vdpa = v->vdpa;
 470         const struct vdpa_config_ops *ops = vdpa->config;
 471         int r = 0;
 472
 473         r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
 474                                   pa, perm);
 475         if (r)
 476                 return r;
 477
 478         if (ops->dma_map)
 479                 r = ops->dma_map(vdpa, iova, size, pa, perm);
 480         else if (ops->set_map)
 481                 r = ops->set_map(vdpa, dev->iotlb);
 482         else
 483                 r = iommu_map(v->domain, iova, pa, size,
 484                               perm_to_iommu_flags(perm));
 485
 486         return r;
 487 }
 488
 489 static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
 490 {
 491         struct vhost_dev *dev = &v->vdev;
 492         struct vdpa_device *vdpa = v->vdpa;
 493         const struct vdpa_config_ops *ops = vdpa->config;
 494
 495         vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
 496
 497         if (ops->dma_map)
 498                 ops->dma_unmap(vdpa, iova, size);
 499         else if (ops->set_map)
 500                 ops->set_map(vdpa, dev->iotlb);
 501         else
 502                 iommu_unmap(v->domain, iova, size);
 503 }
 504
 505 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 506                                            struct vhost_iotlb_msg *msg)
 507 {
 508         struct vhost_dev *dev = &v->vdev;
 509         struct vhost_iotlb *iotlb = dev->iotlb;
 510         struct page **page_list;
 511         unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
 512         unsigned int gup_flags = FOLL_LONGTERM;
 513         unsigned long npages, cur_base, map_pfn, last_pfn = 0;
 514         unsigned long locked, lock_limit, pinned, i;
 515         u64 iova = msg->iova;
 516         int ret = 0;
 517
 518         if (vhost_iotlb_itree_first(iotlb, msg->iova,
 519                                     msg->iova + msg->size - 1))
 520                 return -EEXIST;
 521
 522         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 523         if (!page_list)
 524                 return -ENOMEM;
 525
 526         if (msg->perm & VHOST_ACCESS_WO)
 527                 gup_flags |= FOLL_WRITE;
 528
 529         npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT;
 530         if (!npages)
 531                 return -EINVAL;
 532
 533         down_read(&dev->mm->mmap_sem);
 534
 535         locked = atomic64_add_return(npages, &dev->mm->pinned_vm);
 536         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 537
 538         if (locked > lock_limit) {
 539                 ret = -ENOMEM;
 540                 goto out;
 541         }
 542
 543         cur_base = msg->uaddr & PAGE_MASK;
 544         iova &= PAGE_MASK;
 545
 546         while (npages) {
 547                 pinned = min_t(unsigned long, npages, list_size);
 548                 ret = pin_user_pages(cur_base, pinned,
 549                                      gup_flags, page_list, NULL);
 550                 if (ret != pinned)
 551                         goto out;
 552
 553                 if (!last_pfn)
 554                         map_pfn = page_to_pfn(page_list[0]);
 555
 556                 for (i = 0; i < ret; i++) {
 557                         unsigned long this_pfn = page_to_pfn(page_list[i]);
 558                         u64 csize;
 559
 560                         if (last_pfn && (this_pfn != last_pfn + 1)) {
 561                                 /* Pin a contiguous chunk of memory */
 562                                 csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
 563                                 if (vhost_vdpa_map(v, iova, csize,
 564                                                    map_pfn << PAGE_SHIFT,
 565                                                    msg->perm))
 566                                         goto out;
 567                                 map_pfn = this_pfn;
 568                                 iova += csize;
 569                         }
 570
 571                         last_pfn = this_pfn;
 572                 }
 573
 574                 cur_base += ret << PAGE_SHIFT;
 575                 npages -= ret;
 576         }
 577
 578         /* Pin the rest chunk */
 579         ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
 580                              map_pfn << PAGE_SHIFT, msg->perm);
 581 out:
 582         if (ret) {
 583                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 584                 atomic64_sub(npages, &dev->mm->pinned_vm);
 585         }
 586         up_read(&dev->mm->mmap_sem);
 587         free_page((unsigned long)page_list);
 588         return ret;
 589 }
 590
 591 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
 592                                         struct vhost_iotlb_msg *msg)
 593 {
 594         struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
 595         int r = 0;
 596
 597         r = vhost_dev_check_owner(dev);
 598         if (r)
 599                 return r;
 600
 601         switch (msg->type) {
 602         case VHOST_IOTLB_UPDATE:
 603                 r = vhost_vdpa_process_iotlb_update(v, msg);
 604                 break;
 605         case VHOST_IOTLB_INVALIDATE:
 606                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 607                 break;
 608         default:
 609                 r = -EINVAL;
 610                 break;
 611         }
 612
 613         return r;
 614 }
 615
 616 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
 617                                          struct iov_iter *from)
 618 {
 619         struct file *file = iocb->ki_filp;
 620         struct vhost_vdpa *v = file->private_data;
 621         struct vhost_dev *dev = &v->vdev;
 622
 623         return vhost_chr_write_iter(dev, from);
 624 }
 625
 626 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
 627 {
 628         struct vdpa_device *vdpa = v->vdpa;
 629         const struct vdpa_config_ops *ops = vdpa->config;
 630         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 631         struct bus_type *bus;
 632         int ret;
 633
 634         /* Device want to do DMA by itself */
 635         if (ops->set_map || ops->dma_map)
 636                 return 0;
 637
 638         bus = dma_dev->bus;
 639         if (!bus)
 640                 return -EFAULT;
 641
 642         if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
 643                 return -ENOTSUPP;
 644
 645         v->domain = iommu_domain_alloc(bus);
 646         if (!v->domain)
 647                 return -EIO;
 648
 649         ret = iommu_attach_device(v->domain, dma_dev);
 650         if (ret)
 651                 goto err_attach;
 652
 653         return 0;
 654
 655 err_attach:
 656         iommu_domain_free(v->domain);
 657         return ret;
 658 }
 659
 660 static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
 661 {
 662         struct vdpa_device *vdpa = v->vdpa;
 663         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 664
 665         if (v->domain) {
 666                 iommu_detach_device(v->domain, dma_dev);
 667                 iommu_domain_free(v->domain);
 668         }
 669
 670         v->domain = NULL;
 671 }
 672
 673 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 674 {
 675         struct vhost_vdpa *v;
 676         struct vhost_dev *dev;
 677         struct vhost_virtqueue **vqs;
 678         int nvqs, i, r, opened;
 679
 680         v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
 681         if (!v)
 682                 return -ENODEV;
 683
 684         opened = atomic_cmpxchg(&v->opened, 0, 1);
 685         if (opened)
 686                 return -EBUSY;
 687
 688         nvqs = v->nvqs;
 689         vhost_vdpa_reset(v);
 690
 691         vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
 692         if (!vqs) {
 693                 r = -ENOMEM;
 694                 goto err;
 695         }
 696
 697         dev = &v->vdev;
 698         for (i = 0; i < nvqs; i++) {
 699                 vqs[i] = &v->vqs[i];
 700                 vqs[i]->handle_kick = handle_vq_kick;
 701         }
 702         vhost_dev_init(dev, vqs, nvqs, 0, 0, 0,
 703                        vhost_vdpa_process_iotlb_msg);
 704
 705         dev->iotlb = vhost_iotlb_alloc(0, 0);
 706         if (!dev->iotlb) {
 707                 r = -ENOMEM;
 708                 goto err_init_iotlb;
 709         }
 710
 711         r = vhost_vdpa_alloc_domain(v);
 712         if (r)
 713                 goto err_init_iotlb;
 714
 715         filep->private_data = v;
 716
 717         return 0;
 718
 719 err_init_iotlb:
 720         vhost_dev_cleanup(&v->vdev);
 721 err:
 722         atomic_dec(&v->opened);
 723         return r;
 724 }
 725
 726 static int vhost_vdpa_release(struct inode *inode, struct file *filep)
 727 {
 728         struct vhost_vdpa *v = filep->private_data;
 729         struct vhost_dev *d = &v->vdev;
 730
 731         mutex_lock(&d->mutex);
 732         filep->private_data = NULL;
 733         vhost_vdpa_reset(v);
 734         vhost_dev_stop(&v->vdev);
 735         vhost_vdpa_iotlb_free(v);
 736         vhost_vdpa_free_domain(v);
 737         vhost_dev_cleanup(&v->vdev);
 738         kfree(v->vdev.vqs);
 739         mutex_unlock(&d->mutex);
 740
 741         atomic_dec(&v->opened);
 742         complete(&v->completion);
 743
 744         return 0;
 745 }
 746
 747 static const struct file_operations vhost_vdpa_fops = {
 748         .owner          = THIS_MODULE,
 749         .open           = vhost_vdpa_open,
 750         .release        = vhost_vdpa_release,
 751         .write_iter     = vhost_vdpa_chr_write_iter,
 752         .unlocked_ioctl = vhost_vdpa_unlocked_ioctl,
 753         .compat_ioctl   = compat_ptr_ioctl,
 754 };
 755
 756 static void vhost_vdpa_release_dev(struct device *device)
 757 {
 758         struct vhost_vdpa *v =
 759                container_of(device, struct vhost_vdpa, dev);
 760
 761         ida_simple_remove(&vhost_vdpa_ida, v->minor);
 762         kfree(v->vqs);
 763         kfree(v);
 764 }
 765
 766 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 767 {
 768         const struct vdpa_config_ops *ops = vdpa->config;
 769         struct vhost_vdpa *v;
 770         int minor, nvqs = VHOST_VDPA_VQ_MAX;
 771         int r;
 772
 773         /* Currently, we only accept the network devices. */
 774         if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
 775                 return -ENOTSUPP;
 776
 777         v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 778         if (!v)
 779                 return -ENOMEM;
 780
 781         minor = ida_simple_get(&vhost_vdpa_ida, 0,
 782                                VHOST_VDPA_DEV_MAX, GFP_KERNEL);
 783         if (minor < 0) {
 784                 kfree(v);
 785                 return minor;
 786         }
 787
 788         atomic_set(&v->opened, 0);
 789         v->minor = minor;
 790         v->vdpa = vdpa;
 791         v->nvqs = nvqs;
 792         v->virtio_id = ops->get_device_id(vdpa);
 793
 794         device_initialize(&v->dev);
 795         v->dev.release = vhost_vdpa_release_dev;
 796         v->dev.parent = &vdpa->dev;
 797         v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
 798         v->vqs = kmalloc_array(nvqs, sizeof(struct vhost_virtqueue),
 799                                GFP_KERNEL);
 800         if (!v->vqs) {
 801                 r = -ENOMEM;
 802                 goto err;
 803         }
 804
 805         r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
 806         if (r)
 807                 goto err;
 808
 809         cdev_init(&v->cdev, &vhost_vdpa_fops);
 810         v->cdev.owner = THIS_MODULE;
 811
 812         r = cdev_device_add(&v->cdev, &v->dev);
 813         if (r)
 814                 goto err;
 815
 816         init_completion(&v->completion);
 817         vdpa_set_drvdata(vdpa, v);
 818
 819         return 0;
 820
 821 err:
 822         put_device(&v->dev);
 823         return r;
 824 }
 825
 826 static void vhost_vdpa_remove(struct vdpa_device *vdpa)
 827 {
 828         struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
 829         int opened;
 830
 831         cdev_device_del(&v->cdev, &v->dev);
 832
 833         do {
 834                 opened = atomic_cmpxchg(&v->opened, 0, 1);
 835                 if (!opened)
 836                         break;
 837                 wait_for_completion(&v->completion);
 838         } while (1);
 839
 840         put_device(&v->dev);
 841 }
 842
 843 static struct vdpa_driver vhost_vdpa_driver = {
 844         .driver = {
 845                 .name   = "vhost_vdpa",
 846         },
 847         .probe  = vhost_vdpa_probe,
 848         .remove = vhost_vdpa_remove,
 849 };
 850
 851 static int __init vhost_vdpa_init(void)
 852 {
 853         int r;
 854
 855         r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
 856                                 "vhost-vdpa");
 857         if (r)
 858                 goto err_alloc_chrdev;
 859
 860         r = vdpa_register_driver(&vhost_vdpa_driver);
 861         if (r)
 862                 goto err_vdpa_register_driver;
 863
 864         return 0;
 865
 866 err_vdpa_register_driver:
 867         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
 868 err_alloc_chrdev:
 869         return r;
 870 }
 871 module_init(vhost_vdpa_init);
 872
 873 static void __exit vhost_vdpa_exit(void)
 874 {
 875         vdpa_unregister_driver(&vhost_vdpa_driver);
 876         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
 877 }
 878 module_exit(vhost_vdpa_exit);
 879
 880 MODULE_VERSION("0.0.1");
 881 MODULE_LICENSE("GPL v2");
 882 MODULE_AUTHOR("Intel Corporation");
 883 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");