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 <[email protected]>
   7  *         Jason Wang <[email protected]>
   8  *
   9  * Thanks Michael S. Tsirkin for the valuable comments and
  10  * suggestions.  And thanks to Cunming Liang and Zhihong Wang for all
  11  * their supports.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/cdev.h>
  17 #include <linux/device.h>
  18 #include <linux/mm.h>
  19 #include <linux/slab.h>
  20 #include <linux/iommu.h>
  21 #include <linux/uuid.h>
  22 #include <linux/vdpa.h>
  23 #include <linux/nospec.h>
  24 #include <linux/vhost.h>
  25
  26 #include "vhost.h"
  27
  28 enum {
  29         VHOST_VDPA_BACKEND_FEATURES =
  30         (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
  31         (1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
  32 };
  33
  34 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
  35
  36 struct vhost_vdpa {
  37         struct vhost_dev vdev;
  38         struct iommu_domain *domain;
  39         struct vhost_virtqueue *vqs;
  40         struct completion completion;
  41         struct vdpa_device *vdpa;
  42         struct device dev;
  43         struct cdev cdev;
  44         atomic_t opened;
  45         u32 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 int vhost_vdpa_reset(struct vhost_vdpa *v)
 123 {
 124         struct vdpa_device *vdpa = v->vdpa;
 125
 126         v->in_batch = 0;
 127
 128         return vdpa_reset(vdpa);
 129 }
 130
 131 static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
 132 {
 133         struct vdpa_device *vdpa = v->vdpa;
 134         const struct vdpa_config_ops *ops = vdpa->config;
 135         u32 device_id;
 136
 137         device_id = ops->get_device_id(vdpa);
 138
 139         if (copy_to_user(argp, &device_id, sizeof(device_id)))
 140                 return -EFAULT;
 141
 142         return 0;
 143 }
 144
 145 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
 146 {
 147         struct vdpa_device *vdpa = v->vdpa;
 148         const struct vdpa_config_ops *ops = vdpa->config;
 149         u8 status;
 150
 151         status = ops->get_status(vdpa);
 152
 153         if (copy_to_user(statusp, &status, sizeof(status)))
 154                 return -EFAULT;
 155
 156         return 0;
 157 }
 158
 159 static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 160 {
 161         struct vdpa_device *vdpa = v->vdpa;
 162         const struct vdpa_config_ops *ops = vdpa->config;
 163         u8 status, status_old;
 164         u32 nvqs = v->nvqs;
 165         int ret;
 166         u16 i;
 167
 168         if (copy_from_user(&status, statusp, sizeof(status)))
 169                 return -EFAULT;
 170
 171         status_old = ops->get_status(vdpa);
 172
 173         /*
 174          * Userspace shouldn't remove status bits unless reset the
 175          * status to 0.
 176          */
 177         if (status != 0 && (status_old & ~status) != 0)
 178                 return -EINVAL;
 179
 180         if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
 181                 for (i = 0; i < nvqs; i++)
 182                         vhost_vdpa_unsetup_vq_irq(v, i);
 183
 184         if (status == 0) {
 185                 ret = vdpa_reset(vdpa);
 186                 if (ret)
 187                         return ret;
 188         } else
 189                 vdpa_set_status(vdpa, status);
 190
 191         if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
 192                 for (i = 0; i < nvqs; i++)
 193                         vhost_vdpa_setup_vq_irq(v, i);
 194
 195         return 0;
 196 }
 197
 198 static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
 199                                       struct vhost_vdpa_config *c)
 200 {
 201         struct vdpa_device *vdpa = v->vdpa;
 202         size_t size = vdpa->config->get_config_size(vdpa);
 203
 204         if (c->len == 0 || c->off > size)
 205                 return -EINVAL;
 206
 207         if (c->len > size - c->off)
 208                 return -E2BIG;
 209
 210         return 0;
 211 }
 212
 213 static long vhost_vdpa_get_config(struct vhost_vdpa *v,
 214                                   struct vhost_vdpa_config __user *c)
 215 {
 216         struct vdpa_device *vdpa = v->vdpa;
 217         struct vhost_vdpa_config config;
 218         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 219         u8 *buf;
 220
 221         if (copy_from_user(&config, c, size))
 222                 return -EFAULT;
 223         if (vhost_vdpa_config_validate(v, &config))
 224                 return -EINVAL;
 225         buf = kvzalloc(config.len, GFP_KERNEL);
 226         if (!buf)
 227                 return -ENOMEM;
 228
 229         vdpa_get_config(vdpa, config.off, buf, config.len);
 230
 231         if (copy_to_user(c->buf, buf, config.len)) {
 232                 kvfree(buf);
 233                 return -EFAULT;
 234         }
 235
 236         kvfree(buf);
 237         return 0;
 238 }
 239
 240 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
 241                                   struct vhost_vdpa_config __user *c)
 242 {
 243         struct vdpa_device *vdpa = v->vdpa;
 244         struct vhost_vdpa_config config;
 245         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 246         u8 *buf;
 247
 248         if (copy_from_user(&config, c, size))
 249                 return -EFAULT;
 250         if (vhost_vdpa_config_validate(v, &config))
 251                 return -EINVAL;
 252
 253         buf = vmemdup_user(c->buf, config.len);
 254         if (IS_ERR(buf))
 255                 return PTR_ERR(buf);
 256
 257         vdpa_set_config(vdpa, config.off, buf, config.len);
 258
 259         kvfree(buf);
 260         return 0;
 261 }
 262
 263 static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
 264 {
 265         struct vdpa_device *vdpa = v->vdpa;
 266         const struct vdpa_config_ops *ops = vdpa->config;
 267         u64 features;
 268
 269         features = ops->get_device_features(vdpa);
 270
 271         if (copy_to_user(featurep, &features, sizeof(features)))
 272                 return -EFAULT;
 273
 274         return 0;
 275 }
 276
 277 static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
 278 {
 279         struct vdpa_device *vdpa = v->vdpa;
 280         const struct vdpa_config_ops *ops = vdpa->config;
 281         u64 features;
 282
 283         /*
 284          * It's not allowed to change the features after they have
 285          * been negotiated.
 286          */
 287         if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK)
 288                 return -EBUSY;
 289
 290         if (copy_from_user(&features, featurep, sizeof(features)))
 291                 return -EFAULT;
 292
 293         if (vdpa_set_features(vdpa, features))
 294                 return -EINVAL;
 295
 296         return 0;
 297 }
 298
 299 static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
 300 {
 301         struct vdpa_device *vdpa = v->vdpa;
 302         const struct vdpa_config_ops *ops = vdpa->config;
 303         u16 num;
 304
 305         num = ops->get_vq_num_max(vdpa);
 306
 307         if (copy_to_user(argp, &num, sizeof(num)))
 308                 return -EFAULT;
 309
 310         return 0;
 311 }
 312
 313 static void vhost_vdpa_config_put(struct vhost_vdpa *v)
 314 {
 315         if (v->config_ctx) {
 316                 eventfd_ctx_put(v->config_ctx);
 317                 v->config_ctx = NULL;
 318         }
 319 }
 320
 321 static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
 322 {
 323         struct vdpa_callback cb;
 324         int fd;
 325         struct eventfd_ctx *ctx;
 326
 327         cb.callback = vhost_vdpa_config_cb;
 328         cb.private = v;
 329         if (copy_from_user(&fd, argp, sizeof(fd)))
 330                 return  -EFAULT;
 331
 332         ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
 333         swap(ctx, v->config_ctx);
 334
 335         if (!IS_ERR_OR_NULL(ctx))
 336                 eventfd_ctx_put(ctx);
 337
 338         if (IS_ERR(v->config_ctx)) {
 339                 long ret = PTR_ERR(v->config_ctx);
 340
 341                 v->config_ctx = NULL;
 342                 return ret;
 343         }
 344
 345         v->vdpa->config->set_config_cb(v->vdpa, &cb);
 346
 347         return 0;
 348 }
 349
 350 static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
 351 {
 352         struct vhost_vdpa_iova_range range = {
 353                 .first = v->range.first,
 354                 .last = v->range.last,
 355         };
 356
 357         if (copy_to_user(argp, &range, sizeof(range)))
 358                 return -EFAULT;
 359         return 0;
 360 }
 361
 362 static long vhost_vdpa_get_config_size(struct vhost_vdpa *v, u32 __user *argp)
 363 {
 364         struct vdpa_device *vdpa = v->vdpa;
 365         const struct vdpa_config_ops *ops = vdpa->config;
 366         u32 size;
 367
 368         size = ops->get_config_size(vdpa);
 369
 370         if (copy_to_user(argp, &size, sizeof(size)))
 371                 return -EFAULT;
 372
 373         return 0;
 374 }
 375
 376 static long vhost_vdpa_get_vqs_count(struct vhost_vdpa *v, u32 __user *argp)
 377 {
 378         struct vdpa_device *vdpa = v->vdpa;
 379
 380         if (copy_to_user(argp, &vdpa->nvqs, sizeof(vdpa->nvqs)))
 381                 return -EFAULT;
 382
 383         return 0;
 384 }
 385
 386 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 387                                    void __user *argp)
 388 {
 389         struct vdpa_device *vdpa = v->vdpa;
 390         const struct vdpa_config_ops *ops = vdpa->config;
 391         struct vdpa_vq_state vq_state;
 392         struct vdpa_callback cb;
 393         struct vhost_virtqueue *vq;
 394         struct vhost_vring_state s;
 395         u32 idx;
 396         long r;
 397
 398         r = get_user(idx, (u32 __user *)argp);
 399         if (r < 0)
 400                 return r;
 401
 402         if (idx >= v->nvqs)
 403                 return -ENOBUFS;
 404
 405         idx = array_index_nospec(idx, v->nvqs);
 406         vq = &v->vqs[idx];
 407
 408         switch (cmd) {
 409         case VHOST_VDPA_SET_VRING_ENABLE:
 410                 if (copy_from_user(&s, argp, sizeof(s)))
 411                         return -EFAULT;
 412                 ops->set_vq_ready(vdpa, idx, s.num);
 413                 return 0;
 414         case VHOST_GET_VRING_BASE:
 415                 r = ops->get_vq_state(v->vdpa, idx, &vq_state);
 416                 if (r)
 417                         return r;
 418
 419                 vq->last_avail_idx = vq_state.split.avail_index;
 420                 break;
 421         }
 422
 423         r = vhost_vring_ioctl(&v->vdev, cmd, argp);
 424         if (r)
 425                 return r;
 426
 427         switch (cmd) {
 428         case VHOST_SET_VRING_ADDR:
 429                 if (ops->set_vq_address(vdpa, idx,
 430                                         (u64)(uintptr_t)vq->desc,
 431                                         (u64)(uintptr_t)vq->avail,
 432                                         (u64)(uintptr_t)vq->used))
 433                         r = -EINVAL;
 434                 break;
 435
 436         case VHOST_SET_VRING_BASE:
 437                 vq_state.split.avail_index = vq->last_avail_idx;
 438                 if (ops->set_vq_state(vdpa, idx, &vq_state))
 439                         r = -EINVAL;
 440                 break;
 441
 442         case VHOST_SET_VRING_CALL:
 443                 if (vq->call_ctx.ctx) {
 444                         cb.callback = vhost_vdpa_virtqueue_cb;
 445                         cb.private = vq;
 446                 } else {
 447                         cb.callback = NULL;
 448                         cb.private = NULL;
 449                 }
 450                 ops->set_vq_cb(vdpa, idx, &cb);
 451                 vhost_vdpa_setup_vq_irq(v, idx);
 452                 break;
 453
 454         case VHOST_SET_VRING_NUM:
 455                 ops->set_vq_num(vdpa, idx, vq->num);
 456                 break;
 457         }
 458
 459         return r;
 460 }
 461
 462 static long vhost_vdpa_unlocked_ioctl(struct file *filep,
 463                                       unsigned int cmd, unsigned long arg)
 464 {
 465         struct vhost_vdpa *v = filep->private_data;
 466         struct vhost_dev *d = &v->vdev;
 467         void __user *argp = (void __user *)arg;
 468         u64 __user *featurep = argp;
 469         u64 features;
 470         long r = 0;
 471
 472         if (cmd == VHOST_SET_BACKEND_FEATURES) {
 473                 if (copy_from_user(&features, featurep, sizeof(features)))
 474                         return -EFAULT;
 475                 if (features & ~VHOST_VDPA_BACKEND_FEATURES)
 476                         return -EOPNOTSUPP;
 477                 vhost_set_backend_features(&v->vdev, features);
 478                 return 0;
 479         }
 480
 481         mutex_lock(&d->mutex);
 482
 483         switch (cmd) {
 484         case VHOST_VDPA_GET_DEVICE_ID:
 485                 r = vhost_vdpa_get_device_id(v, argp);
 486                 break;
 487         case VHOST_VDPA_GET_STATUS:
 488                 r = vhost_vdpa_get_status(v, argp);
 489                 break;
 490         case VHOST_VDPA_SET_STATUS:
 491                 r = vhost_vdpa_set_status(v, argp);
 492                 break;
 493         case VHOST_VDPA_GET_CONFIG:
 494                 r = vhost_vdpa_get_config(v, argp);
 495                 break;
 496         case VHOST_VDPA_SET_CONFIG:
 497                 r = vhost_vdpa_set_config(v, argp);
 498                 break;
 499         case VHOST_GET_FEATURES:
 500                 r = vhost_vdpa_get_features(v, argp);
 501                 break;
 502         case VHOST_SET_FEATURES:
 503                 r = vhost_vdpa_set_features(v, argp);
 504                 break;
 505         case VHOST_VDPA_GET_VRING_NUM:
 506                 r = vhost_vdpa_get_vring_num(v, argp);
 507                 break;
 508         case VHOST_SET_LOG_BASE:
 509         case VHOST_SET_LOG_FD:
 510                 r = -ENOIOCTLCMD;
 511                 break;
 512         case VHOST_VDPA_SET_CONFIG_CALL:
 513                 r = vhost_vdpa_set_config_call(v, argp);
 514                 break;
 515         case VHOST_GET_BACKEND_FEATURES:
 516                 features = VHOST_VDPA_BACKEND_FEATURES;
 517                 if (copy_to_user(featurep, &features, sizeof(features)))
 518                         r = -EFAULT;
 519                 break;
 520         case VHOST_VDPA_GET_IOVA_RANGE:
 521                 r = vhost_vdpa_get_iova_range(v, argp);
 522                 break;
 523         case VHOST_VDPA_GET_CONFIG_SIZE:
 524                 r = vhost_vdpa_get_config_size(v, argp);
 525                 break;
 526         case VHOST_VDPA_GET_VQS_COUNT:
 527                 r = vhost_vdpa_get_vqs_count(v, argp);
 528                 break;
 529         default:
 530                 r = vhost_dev_ioctl(&v->vdev, cmd, argp);
 531                 if (r == -ENOIOCTLCMD)
 532                         r = vhost_vdpa_vring_ioctl(v, cmd, argp);
 533                 break;
 534         }
 535
 536         mutex_unlock(&d->mutex);
 537         return r;
 538 }
 539
 540 static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 541 {
 542         struct vhost_dev *dev = &v->vdev;
 543         struct vhost_iotlb *iotlb = dev->iotlb;
 544         struct vhost_iotlb_map *map;
 545         struct page *page;
 546         unsigned long pfn, pinned;
 547
 548         while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
 549                 pinned = PFN_DOWN(map->size);
 550                 for (pfn = PFN_DOWN(map->addr);
 551                      pinned > 0; pfn++, pinned--) {
 552                         page = pfn_to_page(pfn);
 553                         if (map->perm & VHOST_ACCESS_WO)
 554                                 set_page_dirty_lock(page);
 555                         unpin_user_page(page);
 556                 }
 557                 atomic64_sub(PFN_DOWN(map->size), &dev->mm->pinned_vm);
 558                 vhost_iotlb_map_free(iotlb, map);
 559         }
 560 }
 561
 562 static void vhost_vdpa_va_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 563 {
 564         struct vhost_dev *dev = &v->vdev;
 565         struct vhost_iotlb *iotlb = dev->iotlb;
 566         struct vhost_iotlb_map *map;
 567         struct vdpa_map_file *map_file;
 568
 569         while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
 570                 map_file = (struct vdpa_map_file *)map->opaque;
 571                 fput(map_file->file);
 572                 kfree(map_file);
 573                 vhost_iotlb_map_free(iotlb, map);
 574         }
 575 }
 576
 577 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 578 {
 579         struct vdpa_device *vdpa = v->vdpa;
 580
 581         if (vdpa->use_va)
 582                 return vhost_vdpa_va_unmap(v, start, last);
 583
 584         return vhost_vdpa_pa_unmap(v, start, last);
 585 }
 586
 587 static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
 588 {
 589         struct vhost_dev *dev = &v->vdev;
 590
 591         vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
 592         kfree(dev->iotlb);
 593         dev->iotlb = NULL;
 594 }
 595
 596 static int perm_to_iommu_flags(u32 perm)
 597 {
 598         int flags = 0;
 599
 600         switch (perm) {
 601         case VHOST_ACCESS_WO:
 602                 flags |= IOMMU_WRITE;
 603                 break;
 604         case VHOST_ACCESS_RO:
 605                 flags |= IOMMU_READ;
 606                 break;
 607         case VHOST_ACCESS_RW:
 608                 flags |= (IOMMU_WRITE | IOMMU_READ);
 609                 break;
 610         default:
 611                 WARN(1, "invalidate vhost IOTLB permission\n");
 612                 break;
 613         }
 614
 615         return flags | IOMMU_CACHE;
 616 }
 617
 618 static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova,
 619                           u64 size, u64 pa, u32 perm, void *opaque)
 620 {
 621         struct vhost_dev *dev = &v->vdev;
 622         struct vdpa_device *vdpa = v->vdpa;
 623         const struct vdpa_config_ops *ops = vdpa->config;
 624         int r = 0;
 625
 626         r = vhost_iotlb_add_range_ctx(dev->iotlb, iova, iova + size - 1,
 627                                       pa, perm, opaque);
 628         if (r)
 629                 return r;
 630
 631         if (ops->dma_map) {
 632                 r = ops->dma_map(vdpa, iova, size, pa, perm, opaque);
 633         } else if (ops->set_map) {
 634                 if (!v->in_batch)
 635                         r = ops->set_map(vdpa, dev->iotlb);
 636         } else {
 637                 r = iommu_map(v->domain, iova, pa, size,
 638                               perm_to_iommu_flags(perm));
 639         }
 640         if (r) {
 641                 vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
 642                 return r;
 643         }
 644
 645         if (!vdpa->use_va)
 646                 atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm);
 647
 648         return 0;
 649 }
 650
 651 static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
 652 {
 653         struct vhost_dev *dev = &v->vdev;
 654         struct vdpa_device *vdpa = v->vdpa;
 655         const struct vdpa_config_ops *ops = vdpa->config;
 656
 657         vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
 658
 659         if (ops->dma_map) {
 660                 ops->dma_unmap(vdpa, iova, size);
 661         } else if (ops->set_map) {
 662                 if (!v->in_batch)
 663                         ops->set_map(vdpa, dev->iotlb);
 664         } else {
 665                 iommu_unmap(v->domain, iova, size);
 666         }
 667 }
 668
 669 static int vhost_vdpa_va_map(struct vhost_vdpa *v,
 670                              u64 iova, u64 size, u64 uaddr, u32 perm)
 671 {
 672         struct vhost_dev *dev = &v->vdev;
 673         u64 offset, map_size, map_iova = iova;
 674         struct vdpa_map_file *map_file;
 675         struct vm_area_struct *vma;
 676         int ret = 0;
 677
 678         mmap_read_lock(dev->mm);
 679
 680         while (size) {
 681                 vma = find_vma(dev->mm, uaddr);
 682                 if (!vma) {
 683                         ret = -EINVAL;
 684                         break;
 685                 }
 686                 map_size = min(size, vma->vm_end - uaddr);
 687                 if (!(vma->vm_file && (vma->vm_flags & VM_SHARED) &&
 688                         !(vma->vm_flags & (VM_IO | VM_PFNMAP))))
 689                         goto next;
 690
 691                 map_file = kzalloc(sizeof(*map_file), GFP_KERNEL);
 692                 if (!map_file) {
 693                         ret = -ENOMEM;
 694                         break;
 695                 }
 696                 offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
 697                 map_file->offset = offset;
 698                 map_file->file = get_file(vma->vm_file);
 699                 ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
 700                                      perm, map_file);
 701                 if (ret) {
 702                         fput(map_file->file);
 703                         kfree(map_file);
 704                         break;
 705                 }
 706 next:
 707                 size -= map_size;
 708                 uaddr += map_size;
 709                 map_iova += map_size;
 710         }
 711         if (ret)
 712                 vhost_vdpa_unmap(v, iova, map_iova - iova);
 713
 714         mmap_read_unlock(dev->mm);
 715
 716         return ret;
 717 }
 718
 719 static int vhost_vdpa_pa_map(struct vhost_vdpa *v,
 720                              u64 iova, u64 size, u64 uaddr, u32 perm)
 721 {
 722         struct vhost_dev *dev = &v->vdev;
 723         struct page **page_list;
 724         unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
 725         unsigned int gup_flags = FOLL_LONGTERM;
 726         unsigned long npages, cur_base, map_pfn, last_pfn = 0;
 727         unsigned long lock_limit, sz2pin, nchunks, i;
 728         u64 start = iova;
 729         long pinned;
 730         int ret = 0;
 731
 732         /* Limit the use of memory for bookkeeping */
 733         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 734         if (!page_list)
 735                 return -ENOMEM;
 736
 737         if (perm & VHOST_ACCESS_WO)
 738                 gup_flags |= FOLL_WRITE;
 739
 740         npages = PFN_UP(size + (iova & ~PAGE_MASK));
 741         if (!npages) {
 742                 ret = -EINVAL;
 743                 goto free;
 744         }
 745
 746         mmap_read_lock(dev->mm);
 747
 748         lock_limit = PFN_DOWN(rlimit(RLIMIT_MEMLOCK));
 749         if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
 750                 ret = -ENOMEM;
 751                 goto unlock;
 752         }
 753
 754         cur_base = uaddr & PAGE_MASK;
 755         iova &= PAGE_MASK;
 756         nchunks = 0;
 757
 758         while (npages) {
 759                 sz2pin = min_t(unsigned long, npages, list_size);
 760                 pinned = pin_user_pages(cur_base, sz2pin,
 761                                         gup_flags, page_list, NULL);
 762                 if (sz2pin != pinned) {
 763                         if (pinned < 0) {
 764                                 ret = pinned;
 765                         } else {
 766                                 unpin_user_pages(page_list, pinned);
 767                                 ret = -ENOMEM;
 768                         }
 769                         goto out;
 770                 }
 771                 nchunks++;
 772
 773                 if (!last_pfn)
 774                         map_pfn = page_to_pfn(page_list[0]);
 775
 776                 for (i = 0; i < pinned; i++) {
 777                         unsigned long this_pfn = page_to_pfn(page_list[i]);
 778                         u64 csize;
 779
 780                         if (last_pfn && (this_pfn != last_pfn + 1)) {
 781                                 /* Pin a contiguous chunk of memory */
 782                                 csize = PFN_PHYS(last_pfn - map_pfn + 1);
 783                                 ret = vhost_vdpa_map(v, iova, csize,
 784                                                      PFN_PHYS(map_pfn),
 785                                                      perm, NULL);
 786                                 if (ret) {
 787                                         /*
 788                                          * Unpin the pages that are left unmapped
 789                                          * from this point on in the current
 790                                          * page_list. The remaining outstanding
 791                                          * ones which may stride across several
 792                                          * chunks will be covered in the common
 793                                          * error path subsequently.
 794                                          */
 795                                         unpin_user_pages(&page_list[i],
 796                                                          pinned - i);
 797                                         goto out;
 798                                 }
 799
 800                                 map_pfn = this_pfn;
 801                                 iova += csize;
 802                                 nchunks = 0;
 803                         }
 804
 805                         last_pfn = this_pfn;
 806                 }
 807
 808                 cur_base += PFN_PHYS(pinned);
 809                 npages -= pinned;
 810         }
 811
 812         /* Pin the rest chunk */
 813         ret = vhost_vdpa_map(v, iova, PFN_PHYS(last_pfn - map_pfn + 1),
 814                              PFN_PHYS(map_pfn), perm, NULL);
 815 out:
 816         if (ret) {
 817                 if (nchunks) {
 818                         unsigned long pfn;
 819
 820                         /*
 821                          * Unpin the outstanding pages which are yet to be
 822                          * mapped but haven't due to vdpa_map() or
 823                          * pin_user_pages() failure.
 824                          *
 825                          * Mapped pages are accounted in vdpa_map(), hence
 826                          * the corresponding unpinning will be handled by
 827                          * vdpa_unmap().
 828                          */
 829                         WARN_ON(!last_pfn);
 830                         for (pfn = map_pfn; pfn <= last_pfn; pfn++)
 831                                 unpin_user_page(pfn_to_page(pfn));
 832                 }
 833                 vhost_vdpa_unmap(v, start, size);
 834         }
 835 unlock:
 836         mmap_read_unlock(dev->mm);
 837 free:
 838         free_page((unsigned long)page_list);
 839         return ret;
 840
 841 }
 842
 843 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 844                                            struct vhost_iotlb_msg *msg)
 845 {
 846         struct vhost_dev *dev = &v->vdev;
 847         struct vdpa_device *vdpa = v->vdpa;
 848         struct vhost_iotlb *iotlb = dev->iotlb;
 849
 850         if (msg->iova < v->range.first || !msg->size ||
 851             msg->iova > U64_MAX - msg->size + 1 ||
 852             msg->iova + msg->size - 1 > v->range.last)
 853                 return -EINVAL;
 854
 855         if (vhost_iotlb_itree_first(iotlb, msg->iova,
 856                                     msg->iova + msg->size - 1))
 857                 return -EEXIST;
 858
 859         if (vdpa->use_va)
 860                 return vhost_vdpa_va_map(v, msg->iova, msg->size,
 861                                          msg->uaddr, msg->perm);
 862
 863         return vhost_vdpa_pa_map(v, msg->iova, msg->size, msg->uaddr,
 864                                  msg->perm);
 865 }
 866
 867 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
 868                                         struct vhost_iotlb_msg *msg)
 869 {
 870         struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
 871         struct vdpa_device *vdpa = v->vdpa;
 872         const struct vdpa_config_ops *ops = vdpa->config;
 873         int r = 0;
 874
 875         mutex_lock(&dev->mutex);
 876
 877         r = vhost_dev_check_owner(dev);
 878         if (r)
 879                 goto unlock;
 880
 881         switch (msg->type) {
 882         case VHOST_IOTLB_UPDATE:
 883                 r = vhost_vdpa_process_iotlb_update(v, msg);
 884                 break;
 885         case VHOST_IOTLB_INVALIDATE:
 886                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 887                 break;
 888         case VHOST_IOTLB_BATCH_BEGIN:
 889                 v->in_batch = true;
 890                 break;
 891         case VHOST_IOTLB_BATCH_END:
 892                 if (v->in_batch && ops->set_map)
 893                         ops->set_map(vdpa, dev->iotlb);
 894                 v->in_batch = false;
 895                 break;
 896         default:
 897                 r = -EINVAL;
 898                 break;
 899         }
 900 unlock:
 901         mutex_unlock(&dev->mutex);
 902
 903         return r;
 904 }
 905
 906 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
 907                                          struct iov_iter *from)
 908 {
 909         struct file *file = iocb->ki_filp;
 910         struct vhost_vdpa *v = file->private_data;
 911         struct vhost_dev *dev = &v->vdev;
 912
 913         return vhost_chr_write_iter(dev, from);
 914 }
 915
 916 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
 917 {
 918         struct vdpa_device *vdpa = v->vdpa;
 919         const struct vdpa_config_ops *ops = vdpa->config;
 920         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 921         struct bus_type *bus;
 922         int ret;
 923
 924         /* Device want to do DMA by itself */
 925         if (ops->set_map || ops->dma_map)
 926                 return 0;
 927
 928         bus = dma_dev->bus;
 929         if (!bus)
 930                 return -EFAULT;
 931
 932         if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
 933                 return -ENOTSUPP;
 934
 935         v->domain = iommu_domain_alloc(bus);
 936         if (!v->domain)
 937                 return -EIO;
 938
 939         ret = iommu_attach_device(v->domain, dma_dev);
 940         if (ret)
 941                 goto err_attach;
 942
 943         return 0;
 944
 945 err_attach:
 946         iommu_domain_free(v->domain);
 947         return ret;
 948 }
 949
 950 static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
 951 {
 952         struct vdpa_device *vdpa = v->vdpa;
 953         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 954
 955         if (v->domain) {
 956                 iommu_detach_device(v->domain, dma_dev);
 957                 iommu_domain_free(v->domain);
 958         }
 959
 960         v->domain = NULL;
 961 }
 962
 963 static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
 964 {
 965         struct vdpa_iova_range *range = &v->range;
 966         struct vdpa_device *vdpa = v->vdpa;
 967         const struct vdpa_config_ops *ops = vdpa->config;
 968
 969         if (ops->get_iova_range) {
 970                 *range = ops->get_iova_range(vdpa);
 971         } else if (v->domain && v->domain->geometry.force_aperture) {
 972                 range->first = v->domain->geometry.aperture_start;
 973                 range->last = v->domain->geometry.aperture_end;
 974         } else {
 975                 range->first = 0;
 976                 range->last = ULLONG_MAX;
 977         }
 978 }
 979
 980 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 981 {
 982         struct vhost_vdpa *v;
 983         struct vhost_dev *dev;
 984         struct vhost_virtqueue **vqs;
 985         int r, opened;
 986         u32 i, nvqs;
 987
 988         v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
 989
 990         opened = atomic_cmpxchg(&v->opened, 0, 1);
 991         if (opened)
 992                 return -EBUSY;
 993
 994         nvqs = v->nvqs;
 995         r = vhost_vdpa_reset(v);
 996         if (r)
 997                 goto err;
 998
 999         vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
1000         if (!vqs) {
1001                 r = -ENOMEM;
1002                 goto err;
1003         }
1004
1005         dev = &v->vdev;
1006         for (i = 0; i < nvqs; i++) {
1007                 vqs[i] = &v->vqs[i];
1008                 vqs[i]->handle_kick = handle_vq_kick;
1009         }
1010         vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
1011                        vhost_vdpa_process_iotlb_msg);
1012
1013         dev->iotlb = vhost_iotlb_alloc(0, 0);
1014         if (!dev->iotlb) {
1015                 r = -ENOMEM;
1016                 goto err_init_iotlb;
1017         }
1018
1019         r = vhost_vdpa_alloc_domain(v);
1020         if (r)
1021                 goto err_init_iotlb;
1022
1023         vhost_vdpa_set_iova_range(v);
1024
1025         filep->private_data = v;
1026
1027         return 0;
1028
1029 err_init_iotlb:
1030         vhost_dev_cleanup(&v->vdev);
1031         kfree(vqs);
1032 err:
1033         atomic_dec(&v->opened);
1034         return r;
1035 }
1036
1037 static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
1038 {
1039         u32 i;
1040
1041         for (i = 0; i < v->nvqs; i++)
1042                 vhost_vdpa_unsetup_vq_irq(v, i);
1043 }
1044
1045 static int vhost_vdpa_release(struct inode *inode, struct file *filep)
1046 {
1047         struct vhost_vdpa *v = filep->private_data;
1048         struct vhost_dev *d = &v->vdev;
1049
1050         mutex_lock(&d->mutex);
1051         filep->private_data = NULL;
1052         vhost_vdpa_clean_irq(v);
1053         vhost_vdpa_reset(v);
1054         vhost_dev_stop(&v->vdev);
1055         vhost_vdpa_iotlb_free(v);
1056         vhost_vdpa_free_domain(v);
1057         vhost_vdpa_config_put(v);
1058         vhost_dev_cleanup(&v->vdev);
1059         kfree(v->vdev.vqs);
1060         mutex_unlock(&d->mutex);
1061
1062         atomic_dec(&v->opened);
1063         complete(&v->completion);
1064
1065         return 0;
1066 }
1067
1068 #ifdef CONFIG_MMU
1069 static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf)
1070 {
1071         struct vhost_vdpa *v = vmf->vma->vm_file->private_data;
1072         struct vdpa_device *vdpa = v->vdpa;
1073         const struct vdpa_config_ops *ops = vdpa->config;
1074         struct vdpa_notification_area notify;
1075         struct vm_area_struct *vma = vmf->vma;
1076         u16 index = vma->vm_pgoff;
1077
1078         notify = ops->get_vq_notification(vdpa, index);
1079
1080         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1081         if (remap_pfn_range(vma, vmf->address & PAGE_MASK,
1082                             PFN_DOWN(notify.addr), PAGE_SIZE,
1083                             vma->vm_page_prot))
1084                 return VM_FAULT_SIGBUS;
1085
1086         return VM_FAULT_NOPAGE;
1087 }
1088
1089 static const struct vm_operations_struct vhost_vdpa_vm_ops = {
1090         .fault = vhost_vdpa_fault,
1091 };
1092
1093 static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma)
1094 {
1095         struct vhost_vdpa *v = vma->vm_file->private_data;
1096         struct vdpa_device *vdpa = v->vdpa;
1097         const struct vdpa_config_ops *ops = vdpa->config;
1098         struct vdpa_notification_area notify;
1099         unsigned long index = vma->vm_pgoff;
1100
1101         if (vma->vm_end - vma->vm_start != PAGE_SIZE)
1102                 return -EINVAL;
1103         if ((vma->vm_flags & VM_SHARED) == 0)
1104                 return -EINVAL;
1105         if (vma->vm_flags & VM_READ)
1106                 return -EINVAL;
1107         if (index > 65535)
1108                 return -EINVAL;
1109         if (!ops->get_vq_notification)
1110                 return -ENOTSUPP;
1111
1112         /* To be safe and easily modelled by userspace, We only
1113          * support the doorbell which sits on the page boundary and
1114          * does not share the page with other registers.
1115          */
1116         notify = ops->get_vq_notification(vdpa, index);
1117         if (notify.addr & (PAGE_SIZE - 1))
1118                 return -EINVAL;
1119         if (vma->vm_end - vma->vm_start != notify.size)
1120                 return -ENOTSUPP;
1121
1122         vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
1123         vma->vm_ops = &vhost_vdpa_vm_ops;
1124         return 0;
1125 }
1126 #endif /* CONFIG_MMU */
1127
1128 static const struct file_operations vhost_vdpa_fops = {
1129         .owner          = THIS_MODULE,
1130         .open           = vhost_vdpa_open,
1131         .release        = vhost_vdpa_release,
1132         .write_iter     = vhost_vdpa_chr_write_iter,
1133         .unlocked_ioctl = vhost_vdpa_unlocked_ioctl,
1134 #ifdef CONFIG_MMU
1135         .mmap           = vhost_vdpa_mmap,
1136 #endif /* CONFIG_MMU */
1137         .compat_ioctl   = compat_ptr_ioctl,
1138 };
1139
1140 static void vhost_vdpa_release_dev(struct device *device)
1141 {
1142         struct vhost_vdpa *v =
1143                container_of(device, struct vhost_vdpa, dev);
1144
1145         ida_simple_remove(&vhost_vdpa_ida, v->minor);
1146         kfree(v->vqs);
1147         kfree(v);
1148 }
1149
1150 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
1151 {
1152         const struct vdpa_config_ops *ops = vdpa->config;
1153         struct vhost_vdpa *v;
1154         int minor;
1155         int r;
1156
1157         v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1158         if (!v)
1159                 return -ENOMEM;
1160
1161         minor = ida_simple_get(&vhost_vdpa_ida, 0,
1162                                VHOST_VDPA_DEV_MAX, GFP_KERNEL);
1163         if (minor < 0) {
1164                 kfree(v);
1165                 return minor;
1166         }
1167
1168         atomic_set(&v->opened, 0);
1169         v->minor = minor;
1170         v->vdpa = vdpa;
1171         v->nvqs = vdpa->nvqs;
1172         v->virtio_id = ops->get_device_id(vdpa);
1173
1174         device_initialize(&v->dev);
1175         v->dev.release = vhost_vdpa_release_dev;
1176         v->dev.parent = &vdpa->dev;
1177         v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
1178         v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
1179                                GFP_KERNEL);
1180         if (!v->vqs) {
1181                 r = -ENOMEM;
1182                 goto err;
1183         }
1184
1185         r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
1186         if (r)
1187                 goto err;
1188
1189         cdev_init(&v->cdev, &vhost_vdpa_fops);
1190         v->cdev.owner = THIS_MODULE;
1191
1192         r = cdev_device_add(&v->cdev, &v->dev);
1193         if (r)
1194                 goto err;
1195
1196         init_completion(&v->completion);
1197         vdpa_set_drvdata(vdpa, v);
1198
1199         return 0;
1200
1201 err:
1202         put_device(&v->dev);
1203         return r;
1204 }
1205
1206 static void vhost_vdpa_remove(struct vdpa_device *vdpa)
1207 {
1208         struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
1209         int opened;
1210
1211         cdev_device_del(&v->cdev, &v->dev);
1212
1213         do {
1214                 opened = atomic_cmpxchg(&v->opened, 0, 1);
1215                 if (!opened)
1216                         break;
1217                 wait_for_completion(&v->completion);
1218         } while (1);
1219
1220         put_device(&v->dev);
1221 }
1222
1223 static struct vdpa_driver vhost_vdpa_driver = {
1224         .driver = {
1225                 .name   = "vhost_vdpa",
1226         },
1227         .probe  = vhost_vdpa_probe,
1228         .remove = vhost_vdpa_remove,
1229 };
1230
1231 static int __init vhost_vdpa_init(void)
1232 {
1233         int r;
1234
1235         r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
1236                                 "vhost-vdpa");
1237         if (r)
1238                 goto err_alloc_chrdev;
1239
1240         r = vdpa_register_driver(&vhost_vdpa_driver);
1241         if (r)
1242                 goto err_vdpa_register_driver;
1243
1244         return 0;
1245
1246 err_vdpa_register_driver:
1247         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1248 err_alloc_chrdev:
1249         return r;
1250 }
1251 module_init(vhost_vdpa_init);
1252
1253 static void __exit vhost_vdpa_exit(void)
1254 {
1255         vdpa_unregister_driver(&vhost_vdpa_driver);
1256         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1257 }
1258 module_exit(vhost_vdpa_exit);
1259
1260 MODULE_VERSION("0.0.1");
1261 MODULE_LICENSE("GPL v2");
1262 MODULE_AUTHOR("Intel Corporation");
1263 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");