samples/vfio-mdev/mdpy.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Mediated virtual PCI display host device driver
   4  *
   5  * See mdpy-defs.h for device specs
   6  *
   7  *   (c) Gerd Hoffmann <kraxel@redhat.com>
   8  *
   9  * based on mtty driver which is:
  10  *   Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
  11  *       Author: Neo Jia <cjia@nvidia.com>
  12  *               Kirti Wankhede <kwankhede@nvidia.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  */
  18 #include <linux/init.h>
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/slab.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/cdev.h>
  24 #include <linux/vfio.h>
  25 #include <linux/iommu.h>
  26 #include <linux/sysfs.h>
  27 #include <linux/mdev.h>
  28 #include <linux/pci.h>
  29 #include <drm/drm_fourcc.h>
  30 #include "mdpy-defs.h"
  31
  32 #define MDPY_NAME               "mdpy"
  33 #define MDPY_CLASS_NAME         "mdpy"
  34
  35 #define MDPY_CONFIG_SPACE_SIZE  0xff
  36 #define MDPY_MEMORY_BAR_OFFSET  PAGE_SIZE
  37 #define MDPY_DISPLAY_REGION     16
  38
  39 #define STORE_LE16(addr, val)   (*(u16 *)addr = val)
  40 #define STORE_LE32(addr, val)   (*(u32 *)addr = val)
  41
  42
  43 MODULE_LICENSE("GPL v2");
  44
  45 #define MDPY_TYPE_1 "vga"
  46 #define MDPY_TYPE_2 "xga"
  47 #define MDPY_TYPE_3 "hd"
  48
  49 static struct mdpy_type {
  50         struct mdev_type type;
  51         u32 format;
  52         u32 bytepp;
  53         u32 width;
  54         u32 height;
  55 } mdpy_types[] = {
  56         {
  57                 .type.sysfs_name        = MDPY_TYPE_1,
  58                 .type.pretty_name       = MDPY_CLASS_NAME "-" MDPY_TYPE_1,
  59                 .format = DRM_FORMAT_XRGB8888,
  60                 .bytepp = 4,
  61                 .width  = 640,
  62                 .height = 480,
  63         }, {
  64                 .type.sysfs_name        = MDPY_TYPE_2,
  65                 .type.pretty_name       = MDPY_CLASS_NAME "-" MDPY_TYPE_2,
  66                 .format = DRM_FORMAT_XRGB8888,
  67                 .bytepp = 4,
  68                 .width  = 1024,
  69                 .height = 768,
  70         }, {
  71                 .type.sysfs_name        = MDPY_TYPE_3,
  72                 .type.pretty_name       = MDPY_CLASS_NAME "-" MDPY_TYPE_3,
  73                 .format = DRM_FORMAT_XRGB8888,
  74                 .bytepp = 4,
  75                 .width  = 1920,
  76                 .height = 1080,
  77         },
  78 };
  79
  80 static struct mdev_type *mdpy_mdev_types[] = {
  81         &mdpy_types[0].type,
  82         &mdpy_types[1].type,
  83         &mdpy_types[2].type,
  84 };
  85
  86 static dev_t            mdpy_devt;
  87 static const struct class mdpy_class = {
  88         .name = MDPY_CLASS_NAME,
  89 };
  90 static struct cdev      mdpy_cdev;
  91 static struct device    mdpy_dev;
  92 static struct mdev_parent mdpy_parent;
  93 static const struct vfio_device_ops mdpy_dev_ops;
  94
  95 /* State of each mdev device */
  96 struct mdev_state {
  97         struct vfio_device vdev;
  98         u8 *vconfig;
  99         u32 bar_mask;
 100         struct mutex ops_lock;
 101         struct mdev_device *mdev;
 102         struct vfio_device_info dev_info;
 103
 104         const struct mdpy_type *type;
 105         u32 memsize;
 106         void *memblk;
 107 };
 108
 109 static void mdpy_create_config_space(struct mdev_state *mdev_state)
 110 {
 111         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
 112                    MDPY_PCI_VENDOR_ID);
 113         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
 114                    MDPY_PCI_DEVICE_ID);
 115         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
 116                    MDPY_PCI_SUBVENDOR_ID);
 117         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
 118                    MDPY_PCI_SUBDEVICE_ID);
 119
 120         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
 121                    PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
 122         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS],
 123                    PCI_STATUS_CAP_LIST);
 124         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
 125                    PCI_CLASS_DISPLAY_OTHER);
 126         mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
 127
 128         STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
 129                    PCI_BASE_ADDRESS_SPACE_MEMORY |
 130                    PCI_BASE_ADDRESS_MEM_TYPE_32  |
 131                    PCI_BASE_ADDRESS_MEM_PREFETCH);
 132         mdev_state->bar_mask = ~(mdev_state->memsize) + 1;
 133
 134         /* vendor specific capability for the config registers */
 135         mdev_state->vconfig[PCI_CAPABILITY_LIST]       = MDPY_VENDORCAP_OFFSET;
 136         mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */
 137         mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */
 138         mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE;
 139         STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET],
 140                    mdev_state->type->format);
 141         STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET],
 142                    mdev_state->type->width);
 143         STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET],
 144                    mdev_state->type->height);
 145 }
 146
 147 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
 148                                  char *buf, u32 count)
 149 {
 150         struct device *dev = mdev_dev(mdev_state->mdev);
 151         u32 cfg_addr;
 152
 153         switch (offset) {
 154         case PCI_BASE_ADDRESS_0:
 155                 cfg_addr = *(u32 *)buf;
 156
 157                 if (cfg_addr == 0xffffffff) {
 158                         cfg_addr = (cfg_addr & mdev_state->bar_mask);
 159                 } else {
 160                         cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
 161                         if (cfg_addr)
 162                                 dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr);
 163                 }
 164
 165                 cfg_addr |= (mdev_state->vconfig[offset] &
 166                              ~PCI_BASE_ADDRESS_MEM_MASK);
 167                 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
 168                 break;
 169         }
 170 }
 171
 172 static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf,
 173                            size_t count, loff_t pos, bool is_write)
 174 {
 175         int ret = 0;
 176
 177         mutex_lock(&mdev_state->ops_lock);
 178
 179         if (pos < MDPY_CONFIG_SPACE_SIZE) {
 180                 if (is_write)
 181                         handle_pci_cfg_write(mdev_state, pos, buf, count);
 182                 else
 183                         memcpy(buf, (mdev_state->vconfig + pos), count);
 184
 185         } else if ((pos >= MDPY_MEMORY_BAR_OFFSET) &&
 186                    (pos + count <=
 187                     MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) {
 188                 pos -= MDPY_MEMORY_BAR_OFFSET;
 189                 if (is_write)
 190                         memcpy(mdev_state->memblk, buf, count);
 191                 else
 192                         memcpy(buf, mdev_state->memblk, count);
 193
 194         } else {
 195                 dev_info(mdev_state->vdev.dev,
 196                          "%s: %s @0x%llx (unhandled)\n", __func__,
 197                          is_write ? "WR" : "RD", pos);
 198                 ret = -1;
 199                 goto accessfailed;
 200         }
 201
 202         ret = count;
 203
 204
 205 accessfailed:
 206         mutex_unlock(&mdev_state->ops_lock);
 207
 208         return ret;
 209 }
 210
 211 static int mdpy_reset(struct mdev_state *mdev_state)
 212 {
 213         u32 stride, i;
 214
 215         /* initialize with gray gradient */
 216         stride = mdev_state->type->width * mdev_state->type->bytepp;
 217         for (i = 0; i < mdev_state->type->height; i++)
 218                 memset(mdev_state->memblk + i * stride,
 219                        i * 255 / mdev_state->type->height,
 220                        stride);
 221         return 0;
 222 }
 223
 224 static int mdpy_init_dev(struct vfio_device *vdev)
 225 {
 226         struct mdev_state *mdev_state =
 227                 container_of(vdev, struct mdev_state, vdev);
 228         struct mdev_device *mdev = to_mdev_device(vdev->dev);
 229         const struct mdpy_type *type =
 230                 container_of(mdev->type, struct mdpy_type, type);
 231         u32 fbsize;
 232         int ret = -ENOMEM;
 233
 234         mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL);
 235         if (!mdev_state->vconfig)
 236                 return ret;
 237
 238         fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp);
 239
 240         mdev_state->memblk = vmalloc_user(fbsize);
 241         if (!mdev_state->memblk)
 242                 goto out_vconfig;
 243
 244         mutex_init(&mdev_state->ops_lock);
 245         mdev_state->mdev = mdev;
 246         mdev_state->type = type;
 247         mdev_state->memsize = fbsize;
 248         mdpy_create_config_space(mdev_state);
 249         mdpy_reset(mdev_state);
 250
 251         dev_info(vdev->dev, "%s: %s (%dx%d)\n", __func__, type->type.pretty_name,
 252                  type->width, type->height);
 253         return 0;
 254
 255 out_vconfig:
 256         kfree(mdev_state->vconfig);
 257         return ret;
 258 }
 259
 260 static int mdpy_probe(struct mdev_device *mdev)
 261 {
 262         struct mdev_state *mdev_state;
 263         int ret;
 264
 265         mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
 266                                        &mdpy_dev_ops);
 267         if (IS_ERR(mdev_state))
 268                 return PTR_ERR(mdev_state);
 269
 270         ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
 271         if (ret)
 272                 goto err_put_vdev;
 273         dev_set_drvdata(&mdev->dev, mdev_state);
 274         return 0;
 275
 276 err_put_vdev:
 277         vfio_put_device(&mdev_state->vdev);
 278         return ret;
 279 }
 280
 281 static void mdpy_release_dev(struct vfio_device *vdev)
 282 {
 283         struct mdev_state *mdev_state =
 284                 container_of(vdev, struct mdev_state, vdev);
 285
 286         vfree(mdev_state->memblk);
 287         kfree(mdev_state->vconfig);
 288 }
 289
 290 static void mdpy_remove(struct mdev_device *mdev)
 291 {
 292         struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
 293
 294         dev_info(&mdev->dev, "%s\n", __func__);
 295
 296         vfio_unregister_group_dev(&mdev_state->vdev);
 297         vfio_put_device(&mdev_state->vdev);
 298 }
 299
 300 static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf,
 301                          size_t count, loff_t *ppos)
 302 {
 303         struct mdev_state *mdev_state =
 304                 container_of(vdev, struct mdev_state, vdev);
 305         unsigned int done = 0;
 306         int ret;
 307
 308         while (count) {
 309                 size_t filled;
 310
 311                 if (count >= 4 && !(*ppos % 4)) {
 312                         u32 val;
 313
 314                         ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
 315                                           *ppos, false);
 316                         if (ret <= 0)
 317                                 goto read_err;
 318
 319                         if (copy_to_user(buf, &val, sizeof(val)))
 320                                 goto read_err;
 321
 322                         filled = 4;
 323                 } else if (count >= 2 && !(*ppos % 2)) {
 324                         u16 val;
 325
 326                         ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
 327                                           *ppos, false);
 328                         if (ret <= 0)
 329                                 goto read_err;
 330
 331                         if (copy_to_user(buf, &val, sizeof(val)))
 332                                 goto read_err;
 333
 334                         filled = 2;
 335                 } else {
 336                         u8 val;
 337
 338                         ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
 339                                           *ppos, false);
 340                         if (ret <= 0)
 341                                 goto read_err;
 342
 343                         if (copy_to_user(buf, &val, sizeof(val)))
 344                                 goto read_err;
 345
 346                         filled = 1;
 347                 }
 348
 349                 count -= filled;
 350                 done += filled;
 351                 *ppos += filled;
 352                 buf += filled;
 353         }
 354
 355         return done;
 356
 357 read_err:
 358         return -EFAULT;
 359 }
 360
 361 static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf,
 362                           size_t count, loff_t *ppos)
 363 {
 364         struct mdev_state *mdev_state =
 365                 container_of(vdev, struct mdev_state, vdev);
 366         unsigned int done = 0;
 367         int ret;
 368
 369         while (count) {
 370                 size_t filled;
 371
 372                 if (count >= 4 && !(*ppos % 4)) {
 373                         u32 val;
 374
 375                         if (copy_from_user(&val, buf, sizeof(val)))
 376                                 goto write_err;
 377
 378                         ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
 379                                           *ppos, true);
 380                         if (ret <= 0)
 381                                 goto write_err;
 382
 383                         filled = 4;
 384                 } else if (count >= 2 && !(*ppos % 2)) {
 385                         u16 val;
 386
 387                         if (copy_from_user(&val, buf, sizeof(val)))
 388                                 goto write_err;
 389
 390                         ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
 391                                           *ppos, true);
 392                         if (ret <= 0)
 393                                 goto write_err;
 394
 395                         filled = 2;
 396                 } else {
 397                         u8 val;
 398
 399                         if (copy_from_user(&val, buf, sizeof(val)))
 400                                 goto write_err;
 401
 402                         ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
 403                                           *ppos, true);
 404                         if (ret <= 0)
 405                                 goto write_err;
 406
 407                         filled = 1;
 408                 }
 409                 count -= filled;
 410                 done += filled;
 411                 *ppos += filled;
 412                 buf += filled;
 413         }
 414
 415         return done;
 416 write_err:
 417         return -EFAULT;
 418 }
 419
 420 static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
 421 {
 422         struct mdev_state *mdev_state =
 423                 container_of(vdev, struct mdev_state, vdev);
 424
 425         if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
 426                 return -EINVAL;
 427         if (vma->vm_end < vma->vm_start)
 428                 return -EINVAL;
 429         if (vma->vm_end - vma->vm_start > mdev_state->memsize)
 430                 return -EINVAL;
 431         if ((vma->vm_flags & VM_SHARED) == 0)
 432                 return -EINVAL;
 433
 434         return remap_vmalloc_range(vma, mdev_state->memblk, 0);
 435 }
 436
 437 static int mdpy_get_region_info(struct mdev_state *mdev_state,
 438                                 struct vfio_region_info *region_info,
 439                                 u16 *cap_type_id, void **cap_type)
 440 {
 441         if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
 442             region_info->index != MDPY_DISPLAY_REGION)
 443                 return -EINVAL;
 444
 445         switch (region_info->index) {
 446         case VFIO_PCI_CONFIG_REGION_INDEX:
 447                 region_info->offset = 0;
 448                 region_info->size   = MDPY_CONFIG_SPACE_SIZE;
 449                 region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
 450                                        VFIO_REGION_INFO_FLAG_WRITE);
 451                 break;
 452         case VFIO_PCI_BAR0_REGION_INDEX:
 453         case MDPY_DISPLAY_REGION:
 454                 region_info->offset = MDPY_MEMORY_BAR_OFFSET;
 455                 region_info->size   = mdev_state->memsize;
 456                 region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
 457                                        VFIO_REGION_INFO_FLAG_WRITE |
 458                                        VFIO_REGION_INFO_FLAG_MMAP);
 459                 break;
 460         default:
 461                 region_info->size   = 0;
 462                 region_info->offset = 0;
 463                 region_info->flags  = 0;
 464         }
 465
 466         return 0;
 467 }
 468
 469 static int mdpy_get_irq_info(struct vfio_irq_info *irq_info)
 470 {
 471         irq_info->count = 0;
 472         return 0;
 473 }
 474
 475 static int mdpy_get_device_info(struct vfio_device_info *dev_info)
 476 {
 477         dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
 478         dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
 479         dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
 480         return 0;
 481 }
 482
 483 static int mdpy_query_gfx_plane(struct mdev_state *mdev_state,
 484                                 struct vfio_device_gfx_plane_info *plane)
 485 {
 486         if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
 487                 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
 488                                      VFIO_GFX_PLANE_TYPE_REGION))
 489                         return 0;
 490                 return -EINVAL;
 491         }
 492
 493         if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
 494                 return -EINVAL;
 495
 496         plane->drm_format     = mdev_state->type->format;
 497         plane->width          = mdev_state->type->width;
 498         plane->height         = mdev_state->type->height;
 499         plane->stride         = (mdev_state->type->width *
 500                                  mdev_state->type->bytepp);
 501         plane->size           = mdev_state->memsize;
 502         plane->region_index   = MDPY_DISPLAY_REGION;
 503
 504         /* unused */
 505         plane->drm_format_mod = 0;
 506         plane->x_pos          = 0;
 507         plane->y_pos          = 0;
 508         plane->x_hot          = 0;
 509         plane->y_hot          = 0;
 510
 511         return 0;
 512 }
 513
 514 static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd,
 515                        unsigned long arg)
 516 {
 517         int ret = 0;
 518         unsigned long minsz;
 519         struct mdev_state *mdev_state =
 520                 container_of(vdev, struct mdev_state, vdev);
 521
 522         switch (cmd) {
 523         case VFIO_DEVICE_GET_INFO:
 524         {
 525                 struct vfio_device_info info;
 526
 527                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 528
 529                 if (copy_from_user(&info, (void __user *)arg, minsz))
 530                         return -EFAULT;
 531
 532                 if (info.argsz < minsz)
 533                         return -EINVAL;
 534
 535                 ret = mdpy_get_device_info(&info);
 536                 if (ret)
 537                         return ret;
 538
 539                 memcpy(&mdev_state->dev_info, &info, sizeof(info));
 540
 541                 if (copy_to_user((void __user *)arg, &info, minsz))
 542                         return -EFAULT;
 543
 544                 return 0;
 545         }
 546         case VFIO_DEVICE_GET_REGION_INFO:
 547         {
 548                 struct vfio_region_info info;
 549                 u16 cap_type_id = 0;
 550                 void *cap_type = NULL;
 551
 552                 minsz = offsetofend(struct vfio_region_info, offset);
 553
 554                 if (copy_from_user(&info, (void __user *)arg, minsz))
 555                         return -EFAULT;
 556
 557                 if (info.argsz < minsz)
 558                         return -EINVAL;
 559
 560                 ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id,
 561                                            &cap_type);
 562                 if (ret)
 563                         return ret;
 564
 565                 if (copy_to_user((void __user *)arg, &info, minsz))
 566                         return -EFAULT;
 567
 568                 return 0;
 569         }
 570
 571         case VFIO_DEVICE_GET_IRQ_INFO:
 572         {
 573                 struct vfio_irq_info info;
 574
 575                 minsz = offsetofend(struct vfio_irq_info, count);
 576
 577                 if (copy_from_user(&info, (void __user *)arg, minsz))
 578                         return -EFAULT;
 579
 580                 if ((info.argsz < minsz) ||
 581                     (info.index >= mdev_state->dev_info.num_irqs))
 582                         return -EINVAL;
 583
 584                 ret = mdpy_get_irq_info(&info);
 585                 if (ret)
 586                         return ret;
 587
 588                 if (copy_to_user((void __user *)arg, &info, minsz))
 589                         return -EFAULT;
 590
 591                 return 0;
 592         }
 593
 594         case VFIO_DEVICE_QUERY_GFX_PLANE:
 595         {
 596                 struct vfio_device_gfx_plane_info plane = {};
 597
 598                 minsz = offsetofend(struct vfio_device_gfx_plane_info,
 599                                     region_index);
 600
 601                 if (copy_from_user(&plane, (void __user *)arg, minsz))
 602                         return -EFAULT;
 603
 604                 if (plane.argsz < minsz)
 605                         return -EINVAL;
 606
 607                 ret = mdpy_query_gfx_plane(mdev_state, &plane);
 608                 if (ret)
 609                         return ret;
 610
 611                 if (copy_to_user((void __user *)arg, &plane, minsz))
 612                         return -EFAULT;
 613
 614                 return 0;
 615         }
 616
 617         case VFIO_DEVICE_SET_IRQS:
 618                 return -EINVAL;
 619
 620         case VFIO_DEVICE_RESET:
 621                 return mdpy_reset(mdev_state);
 622         }
 623         return -ENOTTY;
 624 }
 625
 626 static ssize_t
 627 resolution_show(struct device *dev, struct device_attribute *attr,
 628                 char *buf)
 629 {
 630         struct mdev_state *mdev_state = dev_get_drvdata(dev);
 631
 632         return sprintf(buf, "%dx%d\n",
 633                        mdev_state->type->width,
 634                        mdev_state->type->height);
 635 }
 636 static DEVICE_ATTR_RO(resolution);
 637
 638 static struct attribute *mdev_dev_attrs[] = {
 639         &dev_attr_resolution.attr,
 640         NULL,
 641 };
 642
 643 static const struct attribute_group mdev_dev_group = {
 644         .name  = "vendor",
 645         .attrs = mdev_dev_attrs,
 646 };
 647
 648 static const struct attribute_group *mdev_dev_groups[] = {
 649         &mdev_dev_group,
 650         NULL,
 651 };
 652
 653 static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf)
 654 {
 655         struct mdpy_type *type = container_of(mtype, struct mdpy_type, type);
 656
 657         return sprintf(buf, "virtual display, %dx%d framebuffer\n",
 658                        type->width, type->height);
 659 }
 660
 661 static const struct vfio_device_ops mdpy_dev_ops = {
 662         .init = mdpy_init_dev,
 663         .release = mdpy_release_dev,
 664         .read = mdpy_read,
 665         .write = mdpy_write,
 666         .ioctl = mdpy_ioctl,
 667         .mmap = mdpy_mmap,
 668         .bind_iommufd   = vfio_iommufd_emulated_bind,
 669         .unbind_iommufd = vfio_iommufd_emulated_unbind,
 670         .attach_ioas    = vfio_iommufd_emulated_attach_ioas,
 671         .detach_ioas    = vfio_iommufd_emulated_detach_ioas,
 672 };
 673
 674 static struct mdev_driver mdpy_driver = {
 675         .device_api = VFIO_DEVICE_API_PCI_STRING,
 676         .max_instances = 4,
 677         .driver = {
 678                 .name = "mdpy",
 679                 .owner = THIS_MODULE,
 680                 .mod_name = KBUILD_MODNAME,
 681                 .dev_groups = mdev_dev_groups,
 682         },
 683         .probe = mdpy_probe,
 684         .remove = mdpy_remove,
 685         .show_description = mdpy_show_description,
 686 };
 687
 688 static const struct file_operations vd_fops = {
 689         .owner          = THIS_MODULE,
 690 };
 691
 692 static void mdpy_device_release(struct device *dev)
 693 {
 694         /* nothing */
 695 }
 696
 697 static int __init mdpy_dev_init(void)
 698 {
 699         int ret = 0;
 700
 701         ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME);
 702         if (ret < 0) {
 703                 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
 704                 return ret;
 705         }
 706         cdev_init(&mdpy_cdev, &vd_fops);
 707         cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1);
 708         pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
 709
 710         ret = mdev_register_driver(&mdpy_driver);
 711         if (ret)
 712                 goto err_cdev;
 713
 714         ret = class_register(&mdpy_class);
 715         if (ret)
 716                 goto err_driver;
 717         mdpy_dev.class = &mdpy_class;
 718         mdpy_dev.release = mdpy_device_release;
 719         dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
 720
 721         ret = device_register(&mdpy_dev);
 722         if (ret)
 723                 goto err_put;
 724
 725         ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver,
 726                                    mdpy_mdev_types,
 727                                    ARRAY_SIZE(mdpy_mdev_types));
 728         if (ret)
 729                 goto err_device;
 730
 731         return 0;
 732
 733 err_device:
 734         device_del(&mdpy_dev);
 735 err_put:
 736         put_device(&mdpy_dev);
 737         class_unregister(&mdpy_class);
 738 err_driver:
 739         mdev_unregister_driver(&mdpy_driver);
 740 err_cdev:
 741         cdev_del(&mdpy_cdev);
 742         unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
 743         return ret;
 744 }
 745
 746 static void __exit mdpy_dev_exit(void)
 747 {
 748         mdpy_dev.bus = NULL;
 749         mdev_unregister_parent(&mdpy_parent);
 750
 751         device_unregister(&mdpy_dev);
 752         mdev_unregister_driver(&mdpy_driver);
 753         cdev_del(&mdpy_cdev);
 754         unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
 755         class_unregister(&mdpy_class);
 756 }
 757
 758 module_param_named(count, mdpy_driver.max_instances, int, 0444);
 759 MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices");
 760
 761 module_init(mdpy_dev_init)
 762 module_exit(mdpy_dev_exit)