drivers/vdpa/vdpa_sim/vdpa_sim.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VDPA device simulator core.
   4  *
   5  * Copyright (c) 2020, Red Hat Inc. All rights reserved.
   6  *     Author: Jason Wang <jasowang@redhat.com>
   7  *
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/device.h>
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/sched.h>
  16 #include <linux/dma-map-ops.h>
  17 #include <linux/vringh.h>
  18 #include <linux/vdpa.h>
  19 #include <linux/vhost_iotlb.h>
  20
  21 #include "vdpa_sim.h"
  22
  23 #define DRV_VERSION  "0.1"
  24 #define DRV_AUTHOR   "Jason Wang <jasowang@redhat.com>"
  25 #define DRV_DESC     "vDPA Device Simulator core"
  26 #define DRV_LICENSE  "GPL v2"
  27
  28 static int batch_mapping = 1;
  29 module_param(batch_mapping, int, 0444);
  30 MODULE_PARM_DESC(batch_mapping, "Batched mapping 1 -Enable; 0 - Disable");
  31
  32 static int max_iotlb_entries = 2048;
  33 module_param(max_iotlb_entries, int, 0444);
  34 MODULE_PARM_DESC(max_iotlb_entries,
  35                  "Maximum number of iotlb entries. 0 means unlimited. (default: 2048)");
  36
  37 #define VDPASIM_QUEUE_ALIGN PAGE_SIZE
  38 #define VDPASIM_QUEUE_MAX 256
  39 #define VDPASIM_VENDOR_ID 0
  40
  41 static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
  42 {
  43         return container_of(vdpa, struct vdpasim, vdpa);
  44 }
  45
  46 static struct vdpasim *dev_to_sim(struct device *dev)
  47 {
  48         struct vdpa_device *vdpa = dev_to_vdpa(dev);
  49
  50         return vdpa_to_sim(vdpa);
  51 }
  52
  53 static void vdpasim_vq_notify(struct vringh *vring)
  54 {
  55         struct vdpasim_virtqueue *vq =
  56                 container_of(vring, struct vdpasim_virtqueue, vring);
  57
  58         if (!vq->cb)
  59                 return;
  60
  61         vq->cb(vq->private);
  62 }
  63
  64 static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
  65 {
  66         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
  67
  68         vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
  69                           VDPASIM_QUEUE_MAX, false,
  70                           (struct vring_desc *)(uintptr_t)vq->desc_addr,
  71                           (struct vring_avail *)
  72                           (uintptr_t)vq->driver_addr,
  73                           (struct vring_used *)
  74                           (uintptr_t)vq->device_addr);
  75
  76         vq->vring.notify = vdpasim_vq_notify;
  77 }
  78
  79 static void vdpasim_vq_reset(struct vdpasim *vdpasim,
  80                              struct vdpasim_virtqueue *vq)
  81 {
  82         vq->ready = false;
  83         vq->desc_addr = 0;
  84         vq->driver_addr = 0;
  85         vq->device_addr = 0;
  86         vq->cb = NULL;
  87         vq->private = NULL;
  88         vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
  89                           VDPASIM_QUEUE_MAX, false, NULL, NULL, NULL);
  90
  91         vq->vring.notify = NULL;
  92 }
  93
  94 static void vdpasim_reset(struct vdpasim *vdpasim)
  95 {
  96         int i;
  97
  98         for (i = 0; i < vdpasim->dev_attr.nvqs; i++)
  99                 vdpasim_vq_reset(vdpasim, &vdpasim->vqs[i]);
 100
 101         spin_lock(&vdpasim->iommu_lock);
 102         vhost_iotlb_reset(vdpasim->iommu);
 103         spin_unlock(&vdpasim->iommu_lock);
 104
 105         vdpasim->features = 0;
 106         vdpasim->status = 0;
 107         ++vdpasim->generation;
 108 }
 109
 110 static int dir_to_perm(enum dma_data_direction dir)
 111 {
 112         int perm = -EFAULT;
 113
 114         switch (dir) {
 115         case DMA_FROM_DEVICE:
 116                 perm = VHOST_MAP_WO;
 117                 break;
 118         case DMA_TO_DEVICE:
 119                 perm = VHOST_MAP_RO;
 120                 break;
 121         case DMA_BIDIRECTIONAL:
 122                 perm = VHOST_MAP_RW;
 123                 break;
 124         default:
 125                 break;
 126         }
 127
 128         return perm;
 129 }
 130
 131 static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
 132                                    unsigned long offset, size_t size,
 133                                    enum dma_data_direction dir,
 134                                    unsigned long attrs)
 135 {
 136         struct vdpasim *vdpasim = dev_to_sim(dev);
 137         struct vhost_iotlb *iommu = vdpasim->iommu;
 138         u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset;
 139         int ret, perm = dir_to_perm(dir);
 140
 141         if (perm < 0)
 142                 return DMA_MAPPING_ERROR;
 143
 144         /* For simplicity, use identical mapping to avoid e.g iova
 145          * allocator.
 146          */
 147         spin_lock(&vdpasim->iommu_lock);
 148         ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
 149                                     pa, dir_to_perm(dir));
 150         spin_unlock(&vdpasim->iommu_lock);
 151         if (ret)
 152                 return DMA_MAPPING_ERROR;
 153
 154         return (dma_addr_t)(pa);
 155 }
 156
 157 static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr,
 158                                size_t size, enum dma_data_direction dir,
 159                                unsigned long attrs)
 160 {
 161         struct vdpasim *vdpasim = dev_to_sim(dev);
 162         struct vhost_iotlb *iommu = vdpasim->iommu;
 163
 164         spin_lock(&vdpasim->iommu_lock);
 165         vhost_iotlb_del_range(iommu, (u64)dma_addr,
 166                               (u64)dma_addr + size - 1);
 167         spin_unlock(&vdpasim->iommu_lock);
 168 }
 169
 170 static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
 171                                     dma_addr_t *dma_addr, gfp_t flag,
 172                                     unsigned long attrs)
 173 {
 174         struct vdpasim *vdpasim = dev_to_sim(dev);
 175         struct vhost_iotlb *iommu = vdpasim->iommu;
 176         void *addr = kmalloc(size, flag);
 177         int ret;
 178
 179         spin_lock(&vdpasim->iommu_lock);
 180         if (!addr) {
 181                 *dma_addr = DMA_MAPPING_ERROR;
 182         } else {
 183                 u64 pa = virt_to_phys(addr);
 184
 185                 ret = vhost_iotlb_add_range(iommu, (u64)pa,
 186                                             (u64)pa + size - 1,
 187                                             pa, VHOST_MAP_RW);
 188                 if (ret) {
 189                         *dma_addr = DMA_MAPPING_ERROR;
 190                         kfree(addr);
 191                         addr = NULL;
 192                 } else
 193                         *dma_addr = (dma_addr_t)pa;
 194         }
 195         spin_unlock(&vdpasim->iommu_lock);
 196
 197         return addr;
 198 }
 199
 200 static void vdpasim_free_coherent(struct device *dev, size_t size,
 201                                   void *vaddr, dma_addr_t dma_addr,
 202                                   unsigned long attrs)
 203 {
 204         struct vdpasim *vdpasim = dev_to_sim(dev);
 205         struct vhost_iotlb *iommu = vdpasim->iommu;
 206
 207         spin_lock(&vdpasim->iommu_lock);
 208         vhost_iotlb_del_range(iommu, (u64)dma_addr,
 209                               (u64)dma_addr + size - 1);
 210         spin_unlock(&vdpasim->iommu_lock);
 211
 212         kfree(phys_to_virt((uintptr_t)dma_addr));
 213 }
 214
 215 static const struct dma_map_ops vdpasim_dma_ops = {
 216         .map_page = vdpasim_map_page,
 217         .unmap_page = vdpasim_unmap_page,
 218         .alloc = vdpasim_alloc_coherent,
 219         .free = vdpasim_free_coherent,
 220 };
 221
 222 static const struct vdpa_config_ops vdpasim_config_ops;
 223 static const struct vdpa_config_ops vdpasim_batch_config_ops;
 224
 225 struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
 226 {
 227         const struct vdpa_config_ops *ops;
 228         struct vdpasim *vdpasim;
 229         struct device *dev;
 230         int i, ret = -ENOMEM;
 231
 232         if (batch_mapping)
 233                 ops = &vdpasim_batch_config_ops;
 234         else
 235                 ops = &vdpasim_config_ops;
 236
 237         vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
 238                                     dev_attr->nvqs);
 239         if (!vdpasim)
 240                 goto err_alloc;
 241
 242         vdpasim->dev_attr = *dev_attr;
 243         INIT_WORK(&vdpasim->work, dev_attr->work_fn);
 244         spin_lock_init(&vdpasim->lock);
 245         spin_lock_init(&vdpasim->iommu_lock);
 246
 247         dev = &vdpasim->vdpa.dev;
 248         dev->dma_mask = &dev->coherent_dma_mask;
 249         if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)))
 250                 goto err_iommu;
 251         set_dma_ops(dev, &vdpasim_dma_ops);
 252
 253         vdpasim->config = kzalloc(dev_attr->config_size, GFP_KERNEL);
 254         if (!vdpasim->config)
 255                 goto err_iommu;
 256
 257         vdpasim->vqs = kcalloc(dev_attr->nvqs, sizeof(struct vdpasim_virtqueue),
 258                                GFP_KERNEL);
 259         if (!vdpasim->vqs)
 260                 goto err_iommu;
 261
 262         vdpasim->iommu = vhost_iotlb_alloc(max_iotlb_entries, 0);
 263         if (!vdpasim->iommu)
 264                 goto err_iommu;
 265
 266         vdpasim->buffer = kvmalloc(dev_attr->buffer_size, GFP_KERNEL);
 267         if (!vdpasim->buffer)
 268                 goto err_iommu;
 269
 270         for (i = 0; i < dev_attr->nvqs; i++)
 271                 vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu);
 272
 273         vdpasim->vdpa.dma_dev = dev;
 274
 275         return vdpasim;
 276
 277 err_iommu:
 278         put_device(dev);
 279 err_alloc:
 280         return ERR_PTR(ret);
 281 }
 282 EXPORT_SYMBOL_GPL(vdpasim_create);
 283
 284 static int vdpasim_set_vq_address(struct vdpa_device *vdpa, u16 idx,
 285                                   u64 desc_area, u64 driver_area,
 286                                   u64 device_area)
 287 {
 288         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 289         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 290
 291         vq->desc_addr = desc_area;
 292         vq->driver_addr = driver_area;
 293         vq->device_addr = device_area;
 294
 295         return 0;
 296 }
 297
 298 static void vdpasim_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num)
 299 {
 300         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 301         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 302
 303         vq->num = num;
 304 }
 305
 306 static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
 307 {
 308         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 309         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 310
 311         if (vq->ready)
 312                 schedule_work(&vdpasim->work);
 313 }
 314
 315 static void vdpasim_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
 316                               struct vdpa_callback *cb)
 317 {
 318         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 319         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 320
 321         vq->cb = cb->callback;
 322         vq->private = cb->private;
 323 }
 324
 325 static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready)
 326 {
 327         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 328         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 329
 330         spin_lock(&vdpasim->lock);
 331         vq->ready = ready;
 332         if (vq->ready)
 333                 vdpasim_queue_ready(vdpasim, idx);
 334         spin_unlock(&vdpasim->lock);
 335 }
 336
 337 static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx)
 338 {
 339         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 340         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 341
 342         return vq->ready;
 343 }
 344
 345 static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx,
 346                                 const struct vdpa_vq_state *state)
 347 {
 348         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 349         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 350         struct vringh *vrh = &vq->vring;
 351
 352         spin_lock(&vdpasim->lock);
 353         vrh->last_avail_idx = state->avail_index;
 354         spin_unlock(&vdpasim->lock);
 355
 356         return 0;
 357 }
 358
 359 static int vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx,
 360                                 struct vdpa_vq_state *state)
 361 {
 362         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 363         struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 364         struct vringh *vrh = &vq->vring;
 365
 366         state->avail_index = vrh->last_avail_idx;
 367         return 0;
 368 }
 369
 370 static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
 371 {
 372         return VDPASIM_QUEUE_ALIGN;
 373 }
 374
 375 static u64 vdpasim_get_features(struct vdpa_device *vdpa)
 376 {
 377         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 378
 379         return vdpasim->dev_attr.supported_features;
 380 }
 381
 382 static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
 383 {
 384         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 385
 386         /* DMA mapping must be done by driver */
 387         if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
 388                 return -EINVAL;
 389
 390         vdpasim->features = features & vdpasim->dev_attr.supported_features;
 391
 392         return 0;
 393 }
 394
 395 static void vdpasim_set_config_cb(struct vdpa_device *vdpa,
 396                                   struct vdpa_callback *cb)
 397 {
 398         /* We don't support config interrupt */
 399 }
 400
 401 static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa)
 402 {
 403         return VDPASIM_QUEUE_MAX;
 404 }
 405
 406 static u32 vdpasim_get_device_id(struct vdpa_device *vdpa)
 407 {
 408         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 409
 410         return vdpasim->dev_attr.id;
 411 }
 412
 413 static u32 vdpasim_get_vendor_id(struct vdpa_device *vdpa)
 414 {
 415         return VDPASIM_VENDOR_ID;
 416 }
 417
 418 static u8 vdpasim_get_status(struct vdpa_device *vdpa)
 419 {
 420         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 421         u8 status;
 422
 423         spin_lock(&vdpasim->lock);
 424         status = vdpasim->status;
 425         spin_unlock(&vdpasim->lock);
 426
 427         return status;
 428 }
 429
 430 static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
 431 {
 432         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 433
 434         spin_lock(&vdpasim->lock);
 435         vdpasim->status = status;
 436         if (status == 0)
 437                 vdpasim_reset(vdpasim);
 438         spin_unlock(&vdpasim->lock);
 439 }
 440
 441 static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
 442                              void *buf, unsigned int len)
 443 {
 444         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 445
 446         if (offset + len > vdpasim->dev_attr.config_size)
 447                 return;
 448
 449         if (vdpasim->dev_attr.get_config)
 450                 vdpasim->dev_attr.get_config(vdpasim, vdpasim->config);
 451
 452         memcpy(buf, vdpasim->config + offset, len);
 453 }
 454
 455 static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,
 456                              const void *buf, unsigned int len)
 457 {
 458         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 459
 460         if (offset + len > vdpasim->dev_attr.config_size)
 461                 return;
 462
 463         memcpy(vdpasim->config + offset, buf, len);
 464
 465         if (vdpasim->dev_attr.set_config)
 466                 vdpasim->dev_attr.set_config(vdpasim, vdpasim->config);
 467 }
 468
 469 static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
 470 {
 471         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 472
 473         return vdpasim->generation;
 474 }
 475
 476 static struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
 477 {
 478         struct vdpa_iova_range range = {
 479                 .first = 0ULL,
 480                 .last = ULLONG_MAX,
 481         };
 482
 483         return range;
 484 }
 485
 486 static int vdpasim_set_map(struct vdpa_device *vdpa,
 487                            struct vhost_iotlb *iotlb)
 488 {
 489         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 490         struct vhost_iotlb_map *map;
 491         u64 start = 0ULL, last = 0ULL - 1;
 492         int ret;
 493
 494         spin_lock(&vdpasim->iommu_lock);
 495         vhost_iotlb_reset(vdpasim->iommu);
 496
 497         for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
 498              map = vhost_iotlb_itree_next(map, start, last)) {
 499                 ret = vhost_iotlb_add_range(vdpasim->iommu, map->start,
 500                                             map->last, map->addr, map->perm);
 501                 if (ret)
 502                         goto err;
 503         }
 504         spin_unlock(&vdpasim->iommu_lock);
 505         return 0;
 506
 507 err:
 508         vhost_iotlb_reset(vdpasim->iommu);
 509         spin_unlock(&vdpasim->iommu_lock);
 510         return ret;
 511 }
 512
 513 static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
 514                            u64 pa, u32 perm)
 515 {
 516         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 517         int ret;
 518
 519         spin_lock(&vdpasim->iommu_lock);
 520         ret = vhost_iotlb_add_range(vdpasim->iommu, iova, iova + size - 1, pa,
 521                                     perm);
 522         spin_unlock(&vdpasim->iommu_lock);
 523
 524         return ret;
 525 }
 526
 527 static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size)
 528 {
 529         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 530
 531         spin_lock(&vdpasim->iommu_lock);
 532         vhost_iotlb_del_range(vdpasim->iommu, iova, iova + size - 1);
 533         spin_unlock(&vdpasim->iommu_lock);
 534
 535         return 0;
 536 }
 537
 538 static void vdpasim_free(struct vdpa_device *vdpa)
 539 {
 540         struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 541
 542         cancel_work_sync(&vdpasim->work);
 543         kvfree(vdpasim->buffer);
 544         if (vdpasim->iommu)
 545                 vhost_iotlb_free(vdpasim->iommu);
 546         kfree(vdpasim->vqs);
 547         kfree(vdpasim->config);
 548 }
 549
 550 static const struct vdpa_config_ops vdpasim_config_ops = {
 551         .set_vq_address         = vdpasim_set_vq_address,
 552         .set_vq_num             = vdpasim_set_vq_num,
 553         .kick_vq                = vdpasim_kick_vq,
 554         .set_vq_cb              = vdpasim_set_vq_cb,
 555         .set_vq_ready           = vdpasim_set_vq_ready,
 556         .get_vq_ready           = vdpasim_get_vq_ready,
 557         .set_vq_state           = vdpasim_set_vq_state,
 558         .get_vq_state           = vdpasim_get_vq_state,
 559         .get_vq_align           = vdpasim_get_vq_align,
 560         .get_features           = vdpasim_get_features,
 561         .set_features           = vdpasim_set_features,
 562         .set_config_cb          = vdpasim_set_config_cb,
 563         .get_vq_num_max         = vdpasim_get_vq_num_max,
 564         .get_device_id          = vdpasim_get_device_id,
 565         .get_vendor_id          = vdpasim_get_vendor_id,
 566         .get_status             = vdpasim_get_status,
 567         .set_status             = vdpasim_set_status,
 568         .get_config             = vdpasim_get_config,
 569         .set_config             = vdpasim_set_config,
 570         .get_generation         = vdpasim_get_generation,
 571         .get_iova_range         = vdpasim_get_iova_range,
 572         .dma_map                = vdpasim_dma_map,
 573         .dma_unmap              = vdpasim_dma_unmap,
 574         .free                   = vdpasim_free,
 575 };
 576
 577 static const struct vdpa_config_ops vdpasim_batch_config_ops = {
 578         .set_vq_address         = vdpasim_set_vq_address,
 579         .set_vq_num             = vdpasim_set_vq_num,
 580         .kick_vq                = vdpasim_kick_vq,
 581         .set_vq_cb              = vdpasim_set_vq_cb,
 582         .set_vq_ready           = vdpasim_set_vq_ready,
 583         .get_vq_ready           = vdpasim_get_vq_ready,
 584         .set_vq_state           = vdpasim_set_vq_state,
 585         .get_vq_state           = vdpasim_get_vq_state,
 586         .get_vq_align           = vdpasim_get_vq_align,
 587         .get_features           = vdpasim_get_features,
 588         .set_features           = vdpasim_set_features,
 589         .set_config_cb          = vdpasim_set_config_cb,
 590         .get_vq_num_max         = vdpasim_get_vq_num_max,
 591         .get_device_id          = vdpasim_get_device_id,
 592         .get_vendor_id          = vdpasim_get_vendor_id,
 593         .get_status             = vdpasim_get_status,
 594         .set_status             = vdpasim_set_status,
 595         .get_config             = vdpasim_get_config,
 596         .set_config             = vdpasim_set_config,
 597         .get_generation         = vdpasim_get_generation,
 598         .get_iova_range         = vdpasim_get_iova_range,
 599         .set_map                = vdpasim_set_map,
 600         .free                   = vdpasim_free,
 601 };
 602
 603 MODULE_VERSION(DRV_VERSION);
 604 MODULE_LICENSE(DRV_LICENSE);
 605 MODULE_AUTHOR(DRV_AUTHOR);
 606 MODULE_DESCRIPTION(DRV_DESC);