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/mm.h>
  19 #include <linux/iommu.h>
  20 #include <linux/uuid.h>
  21 #include <linux/vdpa.h>
  22 #include <linux/nospec.h>
  23 #include <linux/vhost.h>
  24 #include <linux/virtio_net.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         if (irq < 0)
 101                 return;
 102
 103         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 104         if (!vq->call_ctx.ctx)
 105                 return;
 106
 107         vq->call_ctx.producer.token = vq->call_ctx.ctx;
 108         vq->call_ctx.producer.irq = irq;
 109         ret = irq_bypass_register_producer(&vq->call_ctx.producer);
 110         if (unlikely(ret))
 111                 dev_info(&v->dev, "vq %u, irq bypass producer (token %p) registration fails, ret =  %d\n",
 112                          qid, vq->call_ctx.producer.token, ret);
 113 }
 114
 115 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
 116 {
 117         struct vhost_virtqueue *vq = &v->vqs[qid];
 118
 119         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 120 }
 121
 122 static void vhost_vdpa_reset(struct vhost_vdpa *v)
 123 {
 124         struct vdpa_device *vdpa = v->vdpa;
 125
 126         vdpa_reset(vdpa);
 127         v->in_batch = 0;
 128 }
 129
 130 static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
 131 {
 132         struct vdpa_device *vdpa = v->vdpa;
 133         const struct vdpa_config_ops *ops = vdpa->config;
 134         u32 device_id;
 135
 136         device_id = ops->get_device_id(vdpa);
 137
 138         if (copy_to_user(argp, &device_id, sizeof(device_id)))
 139                 return -EFAULT;
 140
 141         return 0;
 142 }
 143
 144 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
 145 {
 146         struct vdpa_device *vdpa = v->vdpa;
 147         const struct vdpa_config_ops *ops = vdpa->config;
 148         u8 status;
 149
 150         status = ops->get_status(vdpa);
 151
 152         if (copy_to_user(statusp, &status, sizeof(status)))
 153                 return -EFAULT;
 154
 155         return 0;
 156 }
 157
 158 static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 159 {
 160         struct vdpa_device *vdpa = v->vdpa;
 161         const struct vdpa_config_ops *ops = vdpa->config;
 162         u8 status, status_old;
 163         int nvqs = v->nvqs;
 164         u16 i;
 165
 166         if (copy_from_user(&status, statusp, sizeof(status)))
 167                 return -EFAULT;
 168
 169         status_old = ops->get_status(vdpa);
 170
 171         /*
 172          * Userspace shouldn't remove status bits unless reset the
 173          * status to 0.
 174          */
 175         if (status != 0 && (ops->get_status(vdpa) & ~status) != 0)
 176                 return -EINVAL;
 177
 178         ops->set_status(vdpa, status);
 179
 180         if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
 181                 for (i = 0; i < nvqs; i++)
 182                         vhost_vdpa_setup_vq_irq(v, i);
 183
 184         if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
 185                 for (i = 0; i < nvqs; i++)
 186                         vhost_vdpa_unsetup_vq_irq(v, i);
 187
 188         return 0;
 189 }
 190
 191 static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
 192                                       struct vhost_vdpa_config *c)
 193 {
 194         long size = 0;
 195
 196         switch (v->virtio_id) {
 197         case VIRTIO_ID_NET:
 198                 size = sizeof(struct virtio_net_config);
 199                 break;
 200         }
 201
 202         if (c->len == 0 || c->off > size)
 203                 return -EINVAL;
 204
 205         if (c->len > size - c->off)
 206                 return -E2BIG;
 207
 208         return 0;
 209 }
 210
 211 static long vhost_vdpa_get_config(struct vhost_vdpa *v,
 212                                   struct vhost_vdpa_config __user *c)
 213 {
 214         struct vdpa_device *vdpa = v->vdpa;
 215         struct vhost_vdpa_config config;
 216         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 217         u8 *buf;
 218
 219         if (copy_from_user(&config, c, size))
 220                 return -EFAULT;
 221         if (vhost_vdpa_config_validate(v, &config))
 222                 return -EINVAL;
 223         buf = kvzalloc(config.len, GFP_KERNEL);
 224         if (!buf)
 225                 return -ENOMEM;
 226
 227         vdpa_get_config(vdpa, config.off, buf, config.len);
 228
 229         if (copy_to_user(c->buf, buf, config.len)) {
 230                 kvfree(buf);
 231                 return -EFAULT;
 232         }
 233
 234         kvfree(buf);
 235         return 0;
 236 }
 237
 238 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
 239                                   struct vhost_vdpa_config __user *c)
 240 {
 241         struct vdpa_device *vdpa = v->vdpa;
 242         const struct vdpa_config_ops *ops = vdpa->config;
 243         struct vhost_vdpa_config config;
 244         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 245         u8 *buf;
 246
 247         if (copy_from_user(&config, c, size))
 248                 return -EFAULT;
 249         if (vhost_vdpa_config_validate(v, &config))
 250                 return -EINVAL;
 251         buf = kvzalloc(config.len, GFP_KERNEL);
 252         if (!buf)
 253                 return -ENOMEM;
 254
 255         if (copy_from_user(buf, c->buf, config.len)) {
 256                 kvfree(buf);
 257                 return -EFAULT;
 258         }
 259
 260         ops->set_config(vdpa, config.off, buf, config.len);
 261
 262         kvfree(buf);
 263         return 0;
 264 }
 265
 266 static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
 267 {
 268         struct vdpa_device *vdpa = v->vdpa;
 269         const struct vdpa_config_ops *ops = vdpa->config;
 270         u64 features;
 271
 272         features = ops->get_features(vdpa);
 273
 274         if (copy_to_user(featurep, &features, sizeof(features)))
 275                 return -EFAULT;
 276
 277         return 0;
 278 }
 279
 280 static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
 281 {
 282         struct vdpa_device *vdpa = v->vdpa;
 283         const struct vdpa_config_ops *ops = vdpa->config;
 284         u64 features;
 285
 286         /*
 287          * It's not allowed to change the features after they have
 288          * been negotiated.
 289          */
 290         if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK)
 291                 return -EBUSY;
 292
 293         if (copy_from_user(&features, featurep, sizeof(features)))
 294                 return -EFAULT;
 295
 296         if (vdpa_set_features(vdpa, features))
 297                 return -EINVAL;
 298
 299         return 0;
 300 }
 301
 302 static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
 303 {
 304         struct vdpa_device *vdpa = v->vdpa;
 305         const struct vdpa_config_ops *ops = vdpa->config;
 306         u16 num;
 307
 308         num = ops->get_vq_num_max(vdpa);
 309
 310         if (copy_to_user(argp, &num, sizeof(num)))
 311                 return -EFAULT;
 312
 313         return 0;
 314 }
 315
 316 static void vhost_vdpa_config_put(struct vhost_vdpa *v)
 317 {
 318         if (v->config_ctx) {
 319                 eventfd_ctx_put(v->config_ctx);
 320                 v->config_ctx = NULL;
 321         }
 322 }
 323
 324 static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
 325 {
 326         struct vdpa_callback cb;
 327         int fd;
 328         struct eventfd_ctx *ctx;
 329
 330         cb.callback = vhost_vdpa_config_cb;
 331         cb.private = v;
 332         if (copy_from_user(&fd, argp, sizeof(fd)))
 333                 return  -EFAULT;
 334
 335         ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
 336         swap(ctx, v->config_ctx);
 337
 338         if (!IS_ERR_OR_NULL(ctx))
 339                 eventfd_ctx_put(ctx);
 340
 341         if (IS_ERR(v->config_ctx)) {
 342                 long ret = PTR_ERR(v->config_ctx);
 343
 344                 v->config_ctx = NULL;
 345                 return ret;
 346         }
 347
 348         v->vdpa->config->set_config_cb(v->vdpa, &cb);
 349
 350         return 0;
 351 }
 352
 353 static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
 354 {
 355         struct vhost_vdpa_iova_range range = {
 356                 .first = v->range.first,
 357                 .last = v->range.last,
 358         };
 359
 360         if (copy_to_user(argp, &range, sizeof(range)))
 361                 return -EFAULT;
 362         return 0;
 363 }
 364
 365 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 366                                    void __user *argp)
 367 {
 368         struct vdpa_device *vdpa = v->vdpa;
 369         const struct vdpa_config_ops *ops = vdpa->config;
 370         struct vdpa_vq_state vq_state;
 371         struct vdpa_callback cb;
 372         struct vhost_virtqueue *vq;
 373         struct vhost_vring_state s;
 374         u32 idx;
 375         long r;
 376
 377         r = get_user(idx, (u32 __user *)argp);
 378         if (r < 0)
 379                 return r;
 380
 381         if (idx >= v->nvqs)
 382                 return -ENOBUFS;
 383
 384         idx = array_index_nospec(idx, v->nvqs);
 385         vq = &v->vqs[idx];
 386
 387         switch (cmd) {
 388         case VHOST_VDPA_SET_VRING_ENABLE:
 389                 if (copy_from_user(&s, argp, sizeof(s)))
 390                         return -EFAULT;
 391                 ops->set_vq_ready(vdpa, idx, s.num);
 392                 return 0;
 393         case VHOST_GET_VRING_BASE:
 394                 r = ops->get_vq_state(v->vdpa, idx, &vq_state);
 395                 if (r)
 396                         return r;
 397
 398                 vq->last_avail_idx = vq_state.avail_index;
 399                 break;
 400         }
 401
 402         r = vhost_vring_ioctl(&v->vdev, cmd, argp);
 403         if (r)
 404                 return r;
 405
 406         switch (cmd) {
 407         case VHOST_SET_VRING_ADDR:
 408                 if (ops->set_vq_address(vdpa, idx,
 409                                         (u64)(uintptr_t)vq->desc,
 410                                         (u64)(uintptr_t)vq->avail,
 411                                         (u64)(uintptr_t)vq->used))
 412                         r = -EINVAL;
 413                 break;
 414
 415         case VHOST_SET_VRING_BASE:
 416                 vq_state.avail_index = vq->last_avail_idx;
 417                 if (ops->set_vq_state(vdpa, idx, &vq_state))
 418                         r = -EINVAL;
 419                 break;
 420
 421         case VHOST_SET_VRING_CALL:
 422                 if (vq->call_ctx.ctx) {
 423                         cb.callback = vhost_vdpa_virtqueue_cb;
 424                         cb.private = vq;
 425                 } else {
 426                         cb.callback = NULL;
 427                         cb.private = NULL;
 428                 }
 429                 ops->set_vq_cb(vdpa, idx, &cb);
 430                 vhost_vdpa_setup_vq_irq(v, idx);
 431                 break;
 432
 433         case VHOST_SET_VRING_NUM:
 434                 ops->set_vq_num(vdpa, idx, vq->num);
 435                 break;
 436         }
 437
 438         return r;
 439 }
 440
 441 static long vhost_vdpa_unlocked_ioctl(struct file *filep,
 442                                       unsigned int cmd, unsigned long arg)
 443 {
 444         struct vhost_vdpa *v = filep->private_data;
 445         struct vhost_dev *d = &v->vdev;
 446         void __user *argp = (void __user *)arg;
 447         u64 __user *featurep = argp;
 448         u64 features;
 449         long r = 0;
 450
 451         if (cmd == VHOST_SET_BACKEND_FEATURES) {
 452                 if (copy_from_user(&features, featurep, sizeof(features)))
 453                         return -EFAULT;
 454                 if (features & ~VHOST_VDPA_BACKEND_FEATURES)
 455                         return -EOPNOTSUPP;
 456                 vhost_set_backend_features(&v->vdev, features);
 457                 return 0;
 458         }
 459
 460         mutex_lock(&d->mutex);
 461
 462         switch (cmd) {
 463         case VHOST_VDPA_GET_DEVICE_ID:
 464                 r = vhost_vdpa_get_device_id(v, argp);
 465                 break;
 466         case VHOST_VDPA_GET_STATUS:
 467                 r = vhost_vdpa_get_status(v, argp);
 468                 break;
 469         case VHOST_VDPA_SET_STATUS:
 470                 r = vhost_vdpa_set_status(v, argp);
 471                 break;
 472         case VHOST_VDPA_GET_CONFIG:
 473                 r = vhost_vdpa_get_config(v, argp);
 474                 break;
 475         case VHOST_VDPA_SET_CONFIG:
 476                 r = vhost_vdpa_set_config(v, argp);
 477                 break;
 478         case VHOST_GET_FEATURES:
 479                 r = vhost_vdpa_get_features(v, argp);
 480                 break;
 481         case VHOST_SET_FEATURES:
 482                 r = vhost_vdpa_set_features(v, argp);
 483                 break;
 484         case VHOST_VDPA_GET_VRING_NUM:
 485                 r = vhost_vdpa_get_vring_num(v, argp);
 486                 break;
 487         case VHOST_SET_LOG_BASE:
 488         case VHOST_SET_LOG_FD:
 489                 r = -ENOIOCTLCMD;
 490                 break;
 491         case VHOST_VDPA_SET_CONFIG_CALL:
 492                 r = vhost_vdpa_set_config_call(v, argp);
 493                 break;
 494         case VHOST_GET_BACKEND_FEATURES:
 495                 features = VHOST_VDPA_BACKEND_FEATURES;
 496                 if (copy_to_user(featurep, &features, sizeof(features)))
 497                         r = -EFAULT;
 498                 break;
 499         case VHOST_VDPA_GET_IOVA_RANGE:
 500                 r = vhost_vdpa_get_iova_range(v, argp);
 501                 break;
 502         default:
 503                 r = vhost_dev_ioctl(&v->vdev, cmd, argp);
 504                 if (r == -ENOIOCTLCMD)
 505                         r = vhost_vdpa_vring_ioctl(v, cmd, argp);
 506                 break;
 507         }
 508
 509         mutex_unlock(&d->mutex);
 510         return r;
 511 }
 512
 513 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 514 {
 515         struct vhost_dev *dev = &v->vdev;
 516         struct vhost_iotlb *iotlb = dev->iotlb;
 517         struct vhost_iotlb_map *map;
 518         struct page *page;
 519         unsigned long pfn, pinned;
 520
 521         while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
 522                 pinned = map->size >> PAGE_SHIFT;
 523                 for (pfn = map->addr >> PAGE_SHIFT;
 524                      pinned > 0; pfn++, pinned--) {
 525                         page = pfn_to_page(pfn);
 526                         if (map->perm & VHOST_ACCESS_WO)
 527                                 set_page_dirty_lock(page);
 528                         unpin_user_page(page);
 529                 }
 530                 atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm);
 531                 vhost_iotlb_map_free(iotlb, map);
 532         }
 533 }
 534
 535 static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
 536 {
 537         struct vhost_dev *dev = &v->vdev;
 538
 539         vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
 540         kfree(dev->iotlb);
 541         dev->iotlb = NULL;
 542 }
 543
 544 static int perm_to_iommu_flags(u32 perm)
 545 {
 546         int flags = 0;
 547
 548         switch (perm) {
 549         case VHOST_ACCESS_WO:
 550                 flags |= IOMMU_WRITE;
 551                 break;
 552         case VHOST_ACCESS_RO:
 553                 flags |= IOMMU_READ;
 554                 break;
 555         case VHOST_ACCESS_RW:
 556                 flags |= (IOMMU_WRITE | IOMMU_READ);
 557                 break;
 558         default:
 559                 WARN(1, "invalidate vhost IOTLB permission\n");
 560                 break;
 561         }
 562
 563         return flags | IOMMU_CACHE;
 564 }
 565
 566 static int vhost_vdpa_map(struct vhost_vdpa *v,
 567                           u64 iova, u64 size, u64 pa, u32 perm)
 568 {
 569         struct vhost_dev *dev = &v->vdev;
 570         struct vdpa_device *vdpa = v->vdpa;
 571         const struct vdpa_config_ops *ops = vdpa->config;
 572         int r = 0;
 573
 574         r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
 575                                   pa, perm);
 576         if (r)
 577                 return r;
 578
 579         if (ops->dma_map) {
 580                 r = ops->dma_map(vdpa, iova, size, pa, perm);
 581         } else if (ops->set_map) {
 582                 if (!v->in_batch)
 583                         r = ops->set_map(vdpa, dev->iotlb);
 584         } else {
 585                 r = iommu_map(v->domain, iova, pa, size,
 586                               perm_to_iommu_flags(perm));
 587         }
 588
 589         if (r)
 590                 vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
 591         else
 592                 atomic64_add(size >> PAGE_SHIFT, &dev->mm->pinned_vm);
 593
 594         return r;
 595 }
 596
 597 static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
 598 {
 599         struct vhost_dev *dev = &v->vdev;
 600         struct vdpa_device *vdpa = v->vdpa;
 601         const struct vdpa_config_ops *ops = vdpa->config;
 602
 603         vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
 604
 605         if (ops->dma_map) {
 606                 ops->dma_unmap(vdpa, iova, size);
 607         } else if (ops->set_map) {
 608                 if (!v->in_batch)
 609                         ops->set_map(vdpa, dev->iotlb);
 610         } else {
 611                 iommu_unmap(v->domain, iova, size);
 612         }
 613 }
 614
 615 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 616                                            struct vhost_iotlb_msg *msg)
 617 {
 618         struct vhost_dev *dev = &v->vdev;
 619         struct vhost_iotlb *iotlb = dev->iotlb;
 620         struct page **page_list;
 621         unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
 622         unsigned int gup_flags = FOLL_LONGTERM;
 623         unsigned long npages, cur_base, map_pfn, last_pfn = 0;
 624         unsigned long lock_limit, sz2pin, nchunks, i;
 625         u64 iova = msg->iova;
 626         long pinned;
 627         int ret = 0;
 628
 629         if (msg->iova < v->range.first || !msg->size ||
 630             msg->iova > U64_MAX - msg->size + 1 ||
 631             msg->iova + msg->size - 1 > v->range.last)
 632                 return -EINVAL;
 633
 634         if (vhost_iotlb_itree_first(iotlb, msg->iova,
 635                                     msg->iova + msg->size - 1))
 636                 return -EEXIST;
 637
 638         /* Limit the use of memory for bookkeeping */
 639         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 640         if (!page_list)
 641                 return -ENOMEM;
 642
 643         if (msg->perm & VHOST_ACCESS_WO)
 644                 gup_flags |= FOLL_WRITE;
 645
 646         npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT;
 647         if (!npages) {
 648                 ret = -EINVAL;
 649                 goto free;
 650         }
 651
 652         mmap_read_lock(dev->mm);
 653
 654         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 655         if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
 656                 ret = -ENOMEM;
 657                 goto unlock;
 658         }
 659
 660         cur_base = msg->uaddr & PAGE_MASK;
 661         iova &= PAGE_MASK;
 662         nchunks = 0;
 663
 664         while (npages) {
 665                 sz2pin = min_t(unsigned long, npages, list_size);
 666                 pinned = pin_user_pages(cur_base, sz2pin,
 667                                         gup_flags, page_list, NULL);
 668                 if (sz2pin != pinned) {
 669                         if (pinned < 0) {
 670                                 ret = pinned;
 671                         } else {
 672                                 unpin_user_pages(page_list, pinned);
 673                                 ret = -ENOMEM;
 674                         }
 675                         goto out;
 676                 }
 677                 nchunks++;
 678
 679                 if (!last_pfn)
 680                         map_pfn = page_to_pfn(page_list[0]);
 681
 682                 for (i = 0; i < pinned; i++) {
 683                         unsigned long this_pfn = page_to_pfn(page_list[i]);
 684                         u64 csize;
 685
 686                         if (last_pfn && (this_pfn != last_pfn + 1)) {
 687                                 /* Pin a contiguous chunk of memory */
 688                                 csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
 689                                 ret = vhost_vdpa_map(v, iova, csize,
 690                                                      map_pfn << PAGE_SHIFT,
 691                                                      msg->perm);
 692                                 if (ret) {
 693                                         /*
 694                                          * Unpin the pages that are left unmapped
 695                                          * from this point on in the current
 696                                          * page_list. The remaining outstanding
 697                                          * ones which may stride across several
 698                                          * chunks will be covered in the common
 699                                          * error path subsequently.
 700                                          */
 701                                         unpin_user_pages(&page_list[i],
 702                                                          pinned - i);
 703                                         goto out;
 704                                 }
 705
 706                                 map_pfn = this_pfn;
 707                                 iova += csize;
 708                                 nchunks = 0;
 709                         }
 710
 711                         last_pfn = this_pfn;
 712                 }
 713
 714                 cur_base += pinned << PAGE_SHIFT;
 715                 npages -= pinned;
 716         }
 717
 718         /* Pin the rest chunk */
 719         ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
 720                              map_pfn << PAGE_SHIFT, msg->perm);
 721 out:
 722         if (ret) {
 723                 if (nchunks) {
 724                         unsigned long pfn;
 725
 726                         /*
 727                          * Unpin the outstanding pages which are yet to be
 728                          * mapped but haven't due to vdpa_map() or
 729                          * pin_user_pages() failure.
 730                          *
 731                          * Mapped pages are accounted in vdpa_map(), hence
 732                          * the corresponding unpinning will be handled by
 733                          * vdpa_unmap().
 734                          */
 735                         WARN_ON(!last_pfn);
 736                         for (pfn = map_pfn; pfn <= last_pfn; pfn++)
 737                                 unpin_user_page(pfn_to_page(pfn));
 738                 }
 739                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 740         }
 741 unlock:
 742         mmap_read_unlock(dev->mm);
 743 free:
 744         free_page((unsigned long)page_list);
 745         return ret;
 746 }
 747
 748 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
 749                                         struct vhost_iotlb_msg *msg)
 750 {
 751         struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
 752         struct vdpa_device *vdpa = v->vdpa;
 753         const struct vdpa_config_ops *ops = vdpa->config;
 754         int r = 0;
 755
 756         mutex_lock(&dev->mutex);
 757
 758         r = vhost_dev_check_owner(dev);
 759         if (r)
 760                 goto unlock;
 761
 762         switch (msg->type) {
 763         case VHOST_IOTLB_UPDATE:
 764                 r = vhost_vdpa_process_iotlb_update(v, msg);
 765                 break;
 766         case VHOST_IOTLB_INVALIDATE:
 767                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 768                 break;
 769         case VHOST_IOTLB_BATCH_BEGIN:
 770                 v->in_batch = true;
 771                 break;
 772         case VHOST_IOTLB_BATCH_END:
 773                 if (v->in_batch && ops->set_map)
 774                         ops->set_map(vdpa, dev->iotlb);
 775                 v->in_batch = false;
 776                 break;
 777         default:
 778                 r = -EINVAL;
 779                 break;
 780         }
 781 unlock:
 782         mutex_unlock(&dev->mutex);
 783
 784         return r;
 785 }
 786
 787 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
 788                                          struct iov_iter *from)
 789 {
 790         struct file *file = iocb->ki_filp;
 791         struct vhost_vdpa *v = file->private_data;
 792         struct vhost_dev *dev = &v->vdev;
 793
 794         return vhost_chr_write_iter(dev, from);
 795 }
 796
 797 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
 798 {
 799         struct vdpa_device *vdpa = v->vdpa;
 800         const struct vdpa_config_ops *ops = vdpa->config;
 801         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 802         struct bus_type *bus;
 803         int ret;
 804
 805         /* Device want to do DMA by itself */
 806         if (ops->set_map || ops->dma_map)
 807                 return 0;
 808
 809         bus = dma_dev->bus;
 810         if (!bus)
 811                 return -EFAULT;
 812
 813         if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
 814                 return -ENOTSUPP;
 815
 816         v->domain = iommu_domain_alloc(bus);
 817         if (!v->domain)
 818                 return -EIO;
 819
 820         ret = iommu_attach_device(v->domain, dma_dev);
 821         if (ret)
 822                 goto err_attach;
 823
 824         return 0;
 825
 826 err_attach:
 827         iommu_domain_free(v->domain);
 828         return ret;
 829 }
 830
 831 static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
 832 {
 833         struct vdpa_device *vdpa = v->vdpa;
 834         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 835
 836         if (v->domain) {
 837                 iommu_detach_device(v->domain, dma_dev);
 838                 iommu_domain_free(v->domain);
 839         }
 840
 841         v->domain = NULL;
 842 }
 843
 844 static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
 845 {
 846         struct vdpa_iova_range *range = &v->range;
 847         struct iommu_domain_geometry geo;
 848         struct vdpa_device *vdpa = v->vdpa;
 849         const struct vdpa_config_ops *ops = vdpa->config;
 850
 851         if (ops->get_iova_range) {
 852                 *range = ops->get_iova_range(vdpa);
 853         } else if (v->domain &&
 854                    !iommu_domain_get_attr(v->domain,
 855                    DOMAIN_ATTR_GEOMETRY, &geo) &&
 856                    geo.force_aperture) {
 857                 range->first = geo.aperture_start;
 858                 range->last = geo.aperture_end;
 859         } else {
 860                 range->first = 0;
 861                 range->last = ULLONG_MAX;
 862         }
 863 }
 864
 865 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 866 {
 867         struct vhost_vdpa *v;
 868         struct vhost_dev *dev;
 869         struct vhost_virtqueue **vqs;
 870         int nvqs, i, r, opened;
 871
 872         v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
 873
 874         opened = atomic_cmpxchg(&v->opened, 0, 1);
 875         if (opened)
 876                 return -EBUSY;
 877
 878         nvqs = v->nvqs;
 879         vhost_vdpa_reset(v);
 880
 881         vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
 882         if (!vqs) {
 883                 r = -ENOMEM;
 884                 goto err;
 885         }
 886
 887         dev = &v->vdev;
 888         for (i = 0; i < nvqs; i++) {
 889                 vqs[i] = &v->vqs[i];
 890                 vqs[i]->handle_kick = handle_vq_kick;
 891         }
 892         vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
 893                        vhost_vdpa_process_iotlb_msg);
 894
 895         dev->iotlb = vhost_iotlb_alloc(0, 0);
 896         if (!dev->iotlb) {
 897                 r = -ENOMEM;
 898                 goto err_init_iotlb;
 899         }
 900
 901         r = vhost_vdpa_alloc_domain(v);
 902         if (r)
 903                 goto err_init_iotlb;
 904
 905         vhost_vdpa_set_iova_range(v);
 906
 907         filep->private_data = v;
 908
 909         return 0;
 910
 911 err_init_iotlb:
 912         vhost_dev_cleanup(&v->vdev);
 913         kfree(vqs);
 914 err:
 915         atomic_dec(&v->opened);
 916         return r;
 917 }
 918
 919 static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
 920 {
 921         int i;
 922
 923         for (i = 0; i < v->nvqs; i++)
 924                 vhost_vdpa_unsetup_vq_irq(v, i);
 925 }
 926
 927 static int vhost_vdpa_release(struct inode *inode, struct file *filep)
 928 {
 929         struct vhost_vdpa *v = filep->private_data;
 930         struct vhost_dev *d = &v->vdev;
 931
 932         mutex_lock(&d->mutex);
 933         filep->private_data = NULL;
 934         vhost_vdpa_reset(v);
 935         vhost_dev_stop(&v->vdev);
 936         vhost_vdpa_iotlb_free(v);
 937         vhost_vdpa_free_domain(v);
 938         vhost_vdpa_config_put(v);
 939         vhost_vdpa_clean_irq(v);
 940         vhost_dev_cleanup(&v->vdev);
 941         kfree(v->vdev.vqs);
 942         mutex_unlock(&d->mutex);
 943
 944         atomic_dec(&v->opened);
 945         complete(&v->completion);
 946
 947         return 0;
 948 }
 949
 950 #ifdef CONFIG_MMU
 951 static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf)
 952 {
 953         struct vhost_vdpa *v = vmf->vma->vm_file->private_data;
 954         struct vdpa_device *vdpa = v->vdpa;
 955         const struct vdpa_config_ops *ops = vdpa->config;
 956         struct vdpa_notification_area notify;
 957         struct vm_area_struct *vma = vmf->vma;
 958         u16 index = vma->vm_pgoff;
 959
 960         notify = ops->get_vq_notification(vdpa, index);
 961
 962         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 963         if (remap_pfn_range(vma, vmf->address & PAGE_MASK,
 964                             notify.addr >> PAGE_SHIFT, PAGE_SIZE,
 965                             vma->vm_page_prot))
 966                 return VM_FAULT_SIGBUS;
 967
 968         return VM_FAULT_NOPAGE;
 969 }
 970
 971 static const struct vm_operations_struct vhost_vdpa_vm_ops = {
 972         .fault = vhost_vdpa_fault,
 973 };
 974
 975 static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma)
 976 {
 977         struct vhost_vdpa *v = vma->vm_file->private_data;
 978         struct vdpa_device *vdpa = v->vdpa;
 979         const struct vdpa_config_ops *ops = vdpa->config;
 980         struct vdpa_notification_area notify;
 981         unsigned long index = vma->vm_pgoff;
 982
 983         if (vma->vm_end - vma->vm_start != PAGE_SIZE)
 984                 return -EINVAL;
 985         if ((vma->vm_flags & VM_SHARED) == 0)
 986                 return -EINVAL;
 987         if (vma->vm_flags & VM_READ)
 988                 return -EINVAL;
 989         if (index > 65535)
 990                 return -EINVAL;
 991         if (!ops->get_vq_notification)
 992                 return -ENOTSUPP;
 993
 994         /* To be safe and easily modelled by userspace, We only
 995          * support the doorbell which sits on the page boundary and
 996          * does not share the page with other registers.
 997          */
 998         notify = ops->get_vq_notification(vdpa, index);
 999         if (notify.addr & (PAGE_SIZE - 1))
1000                 return -EINVAL;
1001         if (vma->vm_end - vma->vm_start != notify.size)
1002                 return -ENOTSUPP;
1003
1004         vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
1005         vma->vm_ops = &vhost_vdpa_vm_ops;
1006         return 0;
1007 }
1008 #endif /* CONFIG_MMU */
1009
1010 static const struct file_operations vhost_vdpa_fops = {
1011         .owner          = THIS_MODULE,
1012         .open           = vhost_vdpa_open,
1013         .release        = vhost_vdpa_release,
1014         .write_iter     = vhost_vdpa_chr_write_iter,
1015         .unlocked_ioctl = vhost_vdpa_unlocked_ioctl,
1016 #ifdef CONFIG_MMU
1017         .mmap           = vhost_vdpa_mmap,
1018 #endif /* CONFIG_MMU */
1019         .compat_ioctl   = compat_ptr_ioctl,
1020 };
1021
1022 static void vhost_vdpa_release_dev(struct device *device)
1023 {
1024         struct vhost_vdpa *v =
1025                container_of(device, struct vhost_vdpa, dev);
1026
1027         ida_simple_remove(&vhost_vdpa_ida, v->minor);
1028         kfree(v->vqs);
1029         kfree(v);
1030 }
1031
1032 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
1033 {
1034         const struct vdpa_config_ops *ops = vdpa->config;
1035         struct vhost_vdpa *v;
1036         int minor;
1037         int r;
1038
1039         /* Currently, we only accept the network devices. */
1040         if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
1041                 return -ENOTSUPP;
1042
1043         v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1044         if (!v)
1045                 return -ENOMEM;
1046
1047         minor = ida_simple_get(&vhost_vdpa_ida, 0,
1048                                VHOST_VDPA_DEV_MAX, GFP_KERNEL);
1049         if (minor < 0) {
1050                 kfree(v);
1051                 return minor;
1052         }
1053
1054         atomic_set(&v->opened, 0);
1055         v->minor = minor;
1056         v->vdpa = vdpa;
1057         v->nvqs = vdpa->nvqs;
1058         v->virtio_id = ops->get_device_id(vdpa);
1059
1060         device_initialize(&v->dev);
1061         v->dev.release = vhost_vdpa_release_dev;
1062         v->dev.parent = &vdpa->dev;
1063         v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
1064         v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
1065                                GFP_KERNEL);
1066         if (!v->vqs) {
1067                 r = -ENOMEM;
1068                 goto err;
1069         }
1070
1071         r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
1072         if (r)
1073                 goto err;
1074
1075         cdev_init(&v->cdev, &vhost_vdpa_fops);
1076         v->cdev.owner = THIS_MODULE;
1077
1078         r = cdev_device_add(&v->cdev, &v->dev);
1079         if (r)
1080                 goto err;
1081
1082         init_completion(&v->completion);
1083         vdpa_set_drvdata(vdpa, v);
1084
1085         return 0;
1086
1087 err:
1088         put_device(&v->dev);
1089         return r;
1090 }
1091
1092 static void vhost_vdpa_remove(struct vdpa_device *vdpa)
1093 {
1094         struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
1095         int opened;
1096
1097         cdev_device_del(&v->cdev, &v->dev);
1098
1099         do {
1100                 opened = atomic_cmpxchg(&v->opened, 0, 1);
1101                 if (!opened)
1102                         break;
1103                 wait_for_completion(&v->completion);
1104         } while (1);
1105
1106         put_device(&v->dev);
1107 }
1108
1109 static struct vdpa_driver vhost_vdpa_driver = {
1110         .driver = {
1111                 .name   = "vhost_vdpa",
1112         },
1113         .probe  = vhost_vdpa_probe,
1114         .remove = vhost_vdpa_remove,
1115 };
1116
1117 static int __init vhost_vdpa_init(void)
1118 {
1119         int r;
1120
1121         r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
1122                                 "vhost-vdpa");
1123         if (r)
1124                 goto err_alloc_chrdev;
1125
1126         r = vdpa_register_driver(&vhost_vdpa_driver);
1127         if (r)
1128                 goto err_vdpa_register_driver;
1129
1130         return 0;
1131
1132 err_vdpa_register_driver:
1133         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1134 err_alloc_chrdev:
1135         return r;
1136 }
1137 module_init(vhost_vdpa_init);
1138
1139 static void __exit vhost_vdpa_exit(void)
1140 {
1141         vdpa_unregister_driver(&vhost_vdpa_driver);
1142         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1143 }
1144 module_exit(vhost_vdpa_exit);
1145
1146 MODULE_VERSION("0.0.1");
1147 MODULE_LICENSE("GPL v2");
1148 MODULE_AUTHOR("Intel Corporation");
1149 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");