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 #include <linux/kernel.h>
  26
  27 #include "vhost.h"
  28
  29 enum {
  30         VHOST_VDPA_BACKEND_FEATURES =
  31         (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
  32         (1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
  33 };
  34
  35 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
  36
  37 struct vhost_vdpa {
  38         struct vhost_dev vdev;
  39         struct iommu_domain *domain;
  40         struct vhost_virtqueue *vqs;
  41         struct completion completion;
  42         struct vdpa_device *vdpa;
  43         struct device dev;
  44         struct cdev cdev;
  45         atomic_t opened;
  46         int nvqs;
  47         int virtio_id;
  48         int minor;
  49         struct eventfd_ctx *config_ctx;
  50         int in_batch;
  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         spin_lock(&vq->call_ctx.ctx_lock);
 101         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 102         if (!vq->call_ctx.ctx || irq < 0) {
 103                 spin_unlock(&vq->call_ctx.ctx_lock);
 104                 return;
 105         }
 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         spin_unlock(&vq->call_ctx.ctx_lock);
 111 }
 112
 113 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
 114 {
 115         struct vhost_virtqueue *vq = &v->vqs[qid];
 116
 117         spin_lock(&vq->call_ctx.ctx_lock);
 118         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 119         spin_unlock(&vq->call_ctx.ctx_lock);
 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)
 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 }
 321
 322 static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
 323 {
 324         struct vdpa_callback cb;
 325         int fd;
 326         struct eventfd_ctx *ctx;
 327
 328         cb.callback = vhost_vdpa_config_cb;
 329         cb.private = v->vdpa;
 330         if (copy_from_user(&fd, argp, sizeof(fd)))
 331                 return  -EFAULT;
 332
 333         ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
 334         swap(ctx, v->config_ctx);
 335
 336         if (!IS_ERR_OR_NULL(ctx))
 337                 eventfd_ctx_put(ctx);
 338
 339         if (IS_ERR(v->config_ctx))
 340                 return PTR_ERR(v->config_ctx);
 341
 342         v->vdpa->config->set_config_cb(v->vdpa, &cb);
 343
 344         return 0;
 345 }
 346
 347 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 348                                    void __user *argp)
 349 {
 350         struct vdpa_device *vdpa = v->vdpa;
 351         const struct vdpa_config_ops *ops = vdpa->config;
 352         struct vdpa_vq_state vq_state;
 353         struct vdpa_callback cb;
 354         struct vhost_virtqueue *vq;
 355         struct vhost_vring_state s;
 356         u64 __user *featurep = argp;
 357         u64 features;
 358         u32 idx;
 359         long r;
 360
 361         r = get_user(idx, (u32 __user *)argp);
 362         if (r < 0)
 363                 return r;
 364
 365         if (idx >= v->nvqs)
 366                 return -ENOBUFS;
 367
 368         idx = array_index_nospec(idx, v->nvqs);
 369         vq = &v->vqs[idx];
 370
 371         switch (cmd) {
 372         case VHOST_VDPA_SET_VRING_ENABLE:
 373                 if (copy_from_user(&s, argp, sizeof(s)))
 374                         return -EFAULT;
 375                 ops->set_vq_ready(vdpa, idx, s.num);
 376                 return 0;
 377         case VHOST_GET_VRING_BASE:
 378                 r = ops->get_vq_state(v->vdpa, idx, &vq_state);
 379                 if (r)
 380                         return r;
 381
 382                 vq->last_avail_idx = vq_state.avail_index;
 383                 break;
 384         case VHOST_GET_BACKEND_FEATURES:
 385                 features = VHOST_VDPA_BACKEND_FEATURES;
 386                 if (copy_to_user(featurep, &features, sizeof(features)))
 387                         return -EFAULT;
 388                 return 0;
 389         case VHOST_SET_BACKEND_FEATURES:
 390                 if (copy_from_user(&features, featurep, sizeof(features)))
 391                         return -EFAULT;
 392                 if (features & ~VHOST_VDPA_BACKEND_FEATURES)
 393                         return -EOPNOTSUPP;
 394                 vhost_set_backend_features(&v->vdev, features);
 395                 return 0;
 396         }
 397
 398         r = vhost_vring_ioctl(&v->vdev, cmd, argp);
 399         if (r)
 400                 return r;
 401
 402         switch (cmd) {
 403         case VHOST_SET_VRING_ADDR:
 404                 if (ops->set_vq_address(vdpa, idx,
 405                                         (u64)(uintptr_t)vq->desc,
 406                                         (u64)(uintptr_t)vq->avail,
 407                                         (u64)(uintptr_t)vq->used))
 408                         r = -EINVAL;
 409                 break;
 410
 411         case VHOST_SET_VRING_BASE:
 412                 vq_state.avail_index = vq->last_avail_idx;
 413                 if (ops->set_vq_state(vdpa, idx, &vq_state))
 414                         r = -EINVAL;
 415                 break;
 416
 417         case VHOST_SET_VRING_CALL:
 418                 if (vq->call_ctx.ctx) {
 419                         cb.callback = vhost_vdpa_virtqueue_cb;
 420                         cb.private = vq;
 421                 } else {
 422                         cb.callback = NULL;
 423                         cb.private = NULL;
 424                 }
 425                 ops->set_vq_cb(vdpa, idx, &cb);
 426                 vhost_vdpa_setup_vq_irq(v, idx);
 427                 break;
 428
 429         case VHOST_SET_VRING_NUM:
 430                 ops->set_vq_num(vdpa, idx, vq->num);
 431                 break;
 432         }
 433
 434         return r;
 435 }
 436
 437 static long vhost_vdpa_unlocked_ioctl(struct file *filep,
 438                                       unsigned int cmd, unsigned long arg)
 439 {
 440         struct vhost_vdpa *v = filep->private_data;
 441         struct vhost_dev *d = &v->vdev;
 442         void __user *argp = (void __user *)arg;
 443         long r;
 444
 445         mutex_lock(&d->mutex);
 446
 447         switch (cmd) {
 448         case VHOST_VDPA_GET_DEVICE_ID:
 449                 r = vhost_vdpa_get_device_id(v, argp);
 450                 break;
 451         case VHOST_VDPA_GET_STATUS:
 452                 r = vhost_vdpa_get_status(v, argp);
 453                 break;
 454         case VHOST_VDPA_SET_STATUS:
 455                 r = vhost_vdpa_set_status(v, argp);
 456                 break;
 457         case VHOST_VDPA_GET_CONFIG:
 458                 r = vhost_vdpa_get_config(v, argp);
 459                 break;
 460         case VHOST_VDPA_SET_CONFIG:
 461                 r = vhost_vdpa_set_config(v, argp);
 462                 break;
 463         case VHOST_GET_FEATURES:
 464                 r = vhost_vdpa_get_features(v, argp);
 465                 break;
 466         case VHOST_SET_FEATURES:
 467                 r = vhost_vdpa_set_features(v, argp);
 468                 break;
 469         case VHOST_VDPA_GET_VRING_NUM:
 470                 r = vhost_vdpa_get_vring_num(v, argp);
 471                 break;
 472         case VHOST_SET_LOG_BASE:
 473         case VHOST_SET_LOG_FD:
 474                 r = -ENOIOCTLCMD;
 475                 break;
 476         case VHOST_VDPA_SET_CONFIG_CALL:
 477                 r = vhost_vdpa_set_config_call(v, argp);
 478                 break;
 479         default:
 480                 r = vhost_dev_ioctl(&v->vdev, cmd, argp);
 481                 if (r == -ENOIOCTLCMD)
 482                         r = vhost_vdpa_vring_ioctl(v, cmd, argp);
 483                 break;
 484         }
 485
 486         mutex_unlock(&d->mutex);
 487         return r;
 488 }
 489
 490 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 491 {
 492         struct vhost_dev *dev = &v->vdev;
 493         struct vhost_iotlb *iotlb = dev->iotlb;
 494         struct vhost_iotlb_map *map;
 495         struct page *page;
 496         unsigned long pfn, pinned;
 497
 498         while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
 499                 pinned = map->size >> PAGE_SHIFT;
 500                 for (pfn = map->addr >> PAGE_SHIFT;
 501                      pinned > 0; pfn++, pinned--) {
 502                         page = pfn_to_page(pfn);
 503                         if (map->perm & VHOST_ACCESS_WO)
 504                                 set_page_dirty_lock(page);
 505                         unpin_user_page(page);
 506                 }
 507                 atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm);
 508                 vhost_iotlb_map_free(iotlb, map);
 509         }
 510 }
 511
 512 static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
 513 {
 514         struct vhost_dev *dev = &v->vdev;
 515
 516         vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
 517         kfree(dev->iotlb);
 518         dev->iotlb = NULL;
 519 }
 520
 521 static int perm_to_iommu_flags(u32 perm)
 522 {
 523         int flags = 0;
 524
 525         switch (perm) {
 526         case VHOST_ACCESS_WO:
 527                 flags |= IOMMU_WRITE;
 528                 break;
 529         case VHOST_ACCESS_RO:
 530                 flags |= IOMMU_READ;
 531                 break;
 532         case VHOST_ACCESS_RW:
 533                 flags |= (IOMMU_WRITE | IOMMU_READ);
 534                 break;
 535         default:
 536                 WARN(1, "invalidate vhost IOTLB permission\n");
 537                 break;
 538         }
 539
 540         return flags | IOMMU_CACHE;
 541 }
 542
 543 static int vhost_vdpa_map(struct vhost_vdpa *v,
 544                           u64 iova, u64 size, u64 pa, u32 perm)
 545 {
 546         struct vhost_dev *dev = &v->vdev;
 547         struct vdpa_device *vdpa = v->vdpa;
 548         const struct vdpa_config_ops *ops = vdpa->config;
 549         int r = 0;
 550
 551         r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
 552                                   pa, perm);
 553         if (r)
 554                 return r;
 555
 556         if (ops->dma_map) {
 557                 r = ops->dma_map(vdpa, iova, size, pa, perm);
 558         } else if (ops->set_map) {
 559                 if (!v->in_batch)
 560                         r = ops->set_map(vdpa, dev->iotlb);
 561         } else {
 562                 r = iommu_map(v->domain, iova, pa, size,
 563                               perm_to_iommu_flags(perm));
 564         }
 565
 566         return r;
 567 }
 568
 569 static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
 570 {
 571         struct vhost_dev *dev = &v->vdev;
 572         struct vdpa_device *vdpa = v->vdpa;
 573         const struct vdpa_config_ops *ops = vdpa->config;
 574
 575         vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
 576
 577         if (ops->dma_map) {
 578                 ops->dma_unmap(vdpa, iova, size);
 579         } else if (ops->set_map) {
 580                 if (!v->in_batch)
 581                         ops->set_map(vdpa, dev->iotlb);
 582         } else {
 583                 iommu_unmap(v->domain, iova, size);
 584         }
 585 }
 586
 587 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 588                                            struct vhost_iotlb_msg *msg)
 589 {
 590         struct vhost_dev *dev = &v->vdev;
 591         struct vhost_iotlb *iotlb = dev->iotlb;
 592         struct page **page_list;
 593         unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
 594         unsigned int gup_flags = FOLL_LONGTERM;
 595         unsigned long npages, cur_base, map_pfn, last_pfn = 0;
 596         unsigned long locked, lock_limit, pinned, i;
 597         u64 iova = msg->iova;
 598         int ret = 0;
 599
 600         if (vhost_iotlb_itree_first(iotlb, msg->iova,
 601                                     msg->iova + msg->size - 1))
 602                 return -EEXIST;
 603
 604         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 605         if (!page_list)
 606                 return -ENOMEM;
 607
 608         if (msg->perm & VHOST_ACCESS_WO)
 609                 gup_flags |= FOLL_WRITE;
 610
 611         npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT;
 612         if (!npages)
 613                 return -EINVAL;
 614
 615         mmap_read_lock(dev->mm);
 616
 617         locked = atomic64_add_return(npages, &dev->mm->pinned_vm);
 618         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 619
 620         if (locked > lock_limit) {
 621                 ret = -ENOMEM;
 622                 goto out;
 623         }
 624
 625         cur_base = msg->uaddr & PAGE_MASK;
 626         iova &= PAGE_MASK;
 627
 628         while (npages) {
 629                 pinned = min_t(unsigned long, npages, list_size);
 630                 ret = pin_user_pages(cur_base, pinned,
 631                                      gup_flags, page_list, NULL);
 632                 if (ret != pinned)
 633                         goto out;
 634
 635                 if (!last_pfn)
 636                         map_pfn = page_to_pfn(page_list[0]);
 637
 638                 for (i = 0; i < ret; i++) {
 639                         unsigned long this_pfn = page_to_pfn(page_list[i]);
 640                         u64 csize;
 641
 642                         if (last_pfn && (this_pfn != last_pfn + 1)) {
 643                                 /* Pin a contiguous chunk of memory */
 644                                 csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
 645                                 if (vhost_vdpa_map(v, iova, csize,
 646                                                    map_pfn << PAGE_SHIFT,
 647                                                    msg->perm))
 648                                         goto out;
 649                                 map_pfn = this_pfn;
 650                                 iova += csize;
 651                         }
 652
 653                         last_pfn = this_pfn;
 654                 }
 655
 656                 cur_base += ret << PAGE_SHIFT;
 657                 npages -= ret;
 658         }
 659
 660         /* Pin the rest chunk */
 661         ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
 662                              map_pfn << PAGE_SHIFT, msg->perm);
 663 out:
 664         if (ret) {
 665                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 666                 atomic64_sub(npages, &dev->mm->pinned_vm);
 667         }
 668         mmap_read_unlock(dev->mm);
 669         free_page((unsigned long)page_list);
 670         return ret;
 671 }
 672
 673 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
 674                                         struct vhost_iotlb_msg *msg)
 675 {
 676         struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
 677         struct vdpa_device *vdpa = v->vdpa;
 678         const struct vdpa_config_ops *ops = vdpa->config;
 679         int r = 0;
 680
 681         r = vhost_dev_check_owner(dev);
 682         if (r)
 683                 return r;
 684
 685         switch (msg->type) {
 686         case VHOST_IOTLB_UPDATE:
 687                 r = vhost_vdpa_process_iotlb_update(v, msg);
 688                 break;
 689         case VHOST_IOTLB_INVALIDATE:
 690                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 691                 break;
 692         case VHOST_IOTLB_BATCH_BEGIN:
 693                 v->in_batch = true;
 694                 break;
 695         case VHOST_IOTLB_BATCH_END:
 696                 if (v->in_batch && ops->set_map)
 697                         ops->set_map(vdpa, dev->iotlb);
 698                 v->in_batch = false;
 699                 break;
 700         default:
 701                 r = -EINVAL;
 702                 break;
 703         }
 704
 705         return r;
 706 }
 707
 708 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
 709                                          struct iov_iter *from)
 710 {
 711         struct file *file = iocb->ki_filp;
 712         struct vhost_vdpa *v = file->private_data;
 713         struct vhost_dev *dev = &v->vdev;
 714
 715         return vhost_chr_write_iter(dev, from);
 716 }
 717
 718 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
 719 {
 720         struct vdpa_device *vdpa = v->vdpa;
 721         const struct vdpa_config_ops *ops = vdpa->config;
 722         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 723         struct bus_type *bus;
 724         int ret;
 725
 726         /* Device want to do DMA by itself */
 727         if (ops->set_map || ops->dma_map)
 728                 return 0;
 729
 730         bus = dma_dev->bus;
 731         if (!bus)
 732                 return -EFAULT;
 733
 734         if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
 735                 return -ENOTSUPP;
 736
 737         v->domain = iommu_domain_alloc(bus);
 738         if (!v->domain)
 739                 return -EIO;
 740
 741         ret = iommu_attach_device(v->domain, dma_dev);
 742         if (ret)
 743                 goto err_attach;
 744
 745         return 0;
 746
 747 err_attach:
 748         iommu_domain_free(v->domain);
 749         return ret;
 750 }
 751
 752 static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
 753 {
 754         struct vdpa_device *vdpa = v->vdpa;
 755         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 756
 757         if (v->domain) {
 758                 iommu_detach_device(v->domain, dma_dev);
 759                 iommu_domain_free(v->domain);
 760         }
 761
 762         v->domain = NULL;
 763 }
 764
 765 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 766 {
 767         struct vhost_vdpa *v;
 768         struct vhost_dev *dev;
 769         struct vhost_virtqueue **vqs;
 770         int nvqs, i, r, opened;
 771
 772         v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
 773
 774         opened = atomic_cmpxchg(&v->opened, 0, 1);
 775         if (opened)
 776                 return -EBUSY;
 777
 778         nvqs = v->nvqs;
 779         vhost_vdpa_reset(v);
 780
 781         vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
 782         if (!vqs) {
 783                 r = -ENOMEM;
 784                 goto err;
 785         }
 786
 787         dev = &v->vdev;
 788         for (i = 0; i < nvqs; i++) {
 789                 vqs[i] = &v->vqs[i];
 790                 vqs[i]->handle_kick = handle_vq_kick;
 791         }
 792         vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
 793                        vhost_vdpa_process_iotlb_msg);
 794
 795         dev->iotlb = vhost_iotlb_alloc(0, 0);
 796         if (!dev->iotlb) {
 797                 r = -ENOMEM;
 798                 goto err_init_iotlb;
 799         }
 800
 801         r = vhost_vdpa_alloc_domain(v);
 802         if (r)
 803                 goto err_init_iotlb;
 804
 805         filep->private_data = v;
 806
 807         return 0;
 808
 809 err_init_iotlb:
 810         vhost_dev_cleanup(&v->vdev);
 811 err:
 812         atomic_dec(&v->opened);
 813         return r;
 814 }
 815
 816 static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
 817 {
 818         struct vhost_virtqueue *vq;
 819         int i;
 820
 821         for (i = 0; i < v->nvqs; i++) {
 822                 vq = &v->vqs[i];
 823                 if (vq->call_ctx.producer.irq)
 824                         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 825         }
 826 }
 827
 828 static int vhost_vdpa_release(struct inode *inode, struct file *filep)
 829 {
 830         struct vhost_vdpa *v = filep->private_data;
 831         struct vhost_dev *d = &v->vdev;
 832
 833         mutex_lock(&d->mutex);
 834         filep->private_data = NULL;
 835         vhost_vdpa_reset(v);
 836         vhost_dev_stop(&v->vdev);
 837         vhost_vdpa_iotlb_free(v);
 838         vhost_vdpa_free_domain(v);
 839         vhost_vdpa_config_put(v);
 840         vhost_vdpa_clean_irq(v);
 841         vhost_dev_cleanup(&v->vdev);
 842         kfree(v->vdev.vqs);
 843         mutex_unlock(&d->mutex);
 844
 845         atomic_dec(&v->opened);
 846         complete(&v->completion);
 847
 848         return 0;
 849 }
 850
 851 #ifdef CONFIG_MMU
 852 static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf)
 853 {
 854         struct vhost_vdpa *v = vmf->vma->vm_file->private_data;
 855         struct vdpa_device *vdpa = v->vdpa;
 856         const struct vdpa_config_ops *ops = vdpa->config;
 857         struct vdpa_notification_area notify;
 858         struct vm_area_struct *vma = vmf->vma;
 859         u16 index = vma->vm_pgoff;
 860
 861         notify = ops->get_vq_notification(vdpa, index);
 862
 863         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 864         if (remap_pfn_range(vma, vmf->address & PAGE_MASK,
 865                             notify.addr >> PAGE_SHIFT, PAGE_SIZE,
 866                             vma->vm_page_prot))
 867                 return VM_FAULT_SIGBUS;
 868
 869         return VM_FAULT_NOPAGE;
 870 }
 871
 872 static const struct vm_operations_struct vhost_vdpa_vm_ops = {
 873         .fault = vhost_vdpa_fault,
 874 };
 875
 876 static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma)
 877 {
 878         struct vhost_vdpa *v = vma->vm_file->private_data;
 879         struct vdpa_device *vdpa = v->vdpa;
 880         const struct vdpa_config_ops *ops = vdpa->config;
 881         struct vdpa_notification_area notify;
 882         unsigned long index = vma->vm_pgoff;
 883
 884         if (vma->vm_end - vma->vm_start != PAGE_SIZE)
 885                 return -EINVAL;
 886         if ((vma->vm_flags & VM_SHARED) == 0)
 887                 return -EINVAL;
 888         if (vma->vm_flags & VM_READ)
 889                 return -EINVAL;
 890         if (index > 65535)
 891                 return -EINVAL;
 892         if (!ops->get_vq_notification)
 893                 return -ENOTSUPP;
 894
 895         /* To be safe and easily modelled by userspace, We only
 896          * support the doorbell which sits on the page boundary and
 897          * does not share the page with other registers.
 898          */
 899         notify = ops->get_vq_notification(vdpa, index);
 900         if (notify.addr & (PAGE_SIZE - 1))
 901                 return -EINVAL;
 902         if (vma->vm_end - vma->vm_start != notify.size)
 903                 return -ENOTSUPP;
 904
 905         vma->vm_ops = &vhost_vdpa_vm_ops;
 906         return 0;
 907 }
 908 #endif /* CONFIG_MMU */
 909
 910 static const struct file_operations vhost_vdpa_fops = {
 911         .owner          = THIS_MODULE,
 912         .open           = vhost_vdpa_open,
 913         .release        = vhost_vdpa_release,
 914         .write_iter     = vhost_vdpa_chr_write_iter,
 915         .unlocked_ioctl = vhost_vdpa_unlocked_ioctl,
 916 #ifdef CONFIG_MMU
 917         .mmap           = vhost_vdpa_mmap,
 918 #endif /* CONFIG_MMU */
 919         .compat_ioctl   = compat_ptr_ioctl,
 920 };
 921
 922 static void vhost_vdpa_release_dev(struct device *device)
 923 {
 924         struct vhost_vdpa *v =
 925                container_of(device, struct vhost_vdpa, dev);
 926
 927         ida_simple_remove(&vhost_vdpa_ida, v->minor);
 928         kfree(v->vqs);
 929         kfree(v);
 930 }
 931
 932 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 933 {
 934         const struct vdpa_config_ops *ops = vdpa->config;
 935         struct vhost_vdpa *v;
 936         int minor;
 937         int r;
 938
 939         /* Currently, we only accept the network devices. */
 940         if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
 941                 return -ENOTSUPP;
 942
 943         v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 944         if (!v)
 945                 return -ENOMEM;
 946
 947         minor = ida_simple_get(&vhost_vdpa_ida, 0,
 948                                VHOST_VDPA_DEV_MAX, GFP_KERNEL);
 949         if (minor < 0) {
 950                 kfree(v);
 951                 return minor;
 952         }
 953
 954         atomic_set(&v->opened, 0);
 955         v->minor = minor;
 956         v->vdpa = vdpa;
 957         v->nvqs = vdpa->nvqs;
 958         v->virtio_id = ops->get_device_id(vdpa);
 959
 960         device_initialize(&v->dev);
 961         v->dev.release = vhost_vdpa_release_dev;
 962         v->dev.parent = &vdpa->dev;
 963         v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
 964         v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
 965                                GFP_KERNEL);
 966         if (!v->vqs) {
 967                 r = -ENOMEM;
 968                 goto err;
 969         }
 970
 971         r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
 972         if (r)
 973                 goto err;
 974
 975         cdev_init(&v->cdev, &vhost_vdpa_fops);
 976         v->cdev.owner = THIS_MODULE;
 977
 978         r = cdev_device_add(&v->cdev, &v->dev);
 979         if (r)
 980                 goto err;
 981
 982         init_completion(&v->completion);
 983         vdpa_set_drvdata(vdpa, v);
 984
 985         return 0;
 986
 987 err:
 988         put_device(&v->dev);
 989         return r;
 990 }
 991
 992 static void vhost_vdpa_remove(struct vdpa_device *vdpa)
 993 {
 994         struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
 995         int opened;
 996
 997         cdev_device_del(&v->cdev, &v->dev);
 998
 999         do {
1000                 opened = atomic_cmpxchg(&v->opened, 0, 1);
1001                 if (!opened)
1002                         break;
1003                 wait_for_completion(&v->completion);
1004         } while (1);
1005
1006         put_device(&v->dev);
1007 }
1008
1009 static struct vdpa_driver vhost_vdpa_driver = {
1010         .driver = {
1011                 .name   = "vhost_vdpa",
1012         },
1013         .probe  = vhost_vdpa_probe,
1014         .remove = vhost_vdpa_remove,
1015 };
1016
1017 static int __init vhost_vdpa_init(void)
1018 {
1019         int r;
1020
1021         r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
1022                                 "vhost-vdpa");
1023         if (r)
1024                 goto err_alloc_chrdev;
1025
1026         r = vdpa_register_driver(&vhost_vdpa_driver);
1027         if (r)
1028                 goto err_vdpa_register_driver;
1029
1030         return 0;
1031
1032 err_vdpa_register_driver:
1033         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1034 err_alloc_chrdev:
1035         return r;
1036 }
1037 module_init(vhost_vdpa_init);
1038
1039 static void __exit vhost_vdpa_exit(void)
1040 {
1041         vdpa_unregister_driver(&vhost_vdpa_driver);
1042         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1043 }
1044 module_exit(vhost_vdpa_exit);
1045
1046 MODULE_VERSION("0.0.1");
1047 MODULE_LICENSE("GPL v2");
1048 MODULE_AUTHOR("Intel Corporation");
1049 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");