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 <[email protected]>
   8  *
   9  * based on mtty driver which is:
  10  *   Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
  11  *       Author: Neo Jia <[email protected]>
  12  *               Kirti Wankhede <[email protected]>
  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/device.h>
  21 #include <linux/kernel.h>
  22 #include <linux/slab.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/cdev.h>
  25 #include <linux/vfio.h>
  26 #include <linux/iommu.h>
  27 #include <linux/sysfs.h>
  28 #include <linux/mdev.h>
  29 #include <linux/pci.h>
  30 #include <drm/drm_fourcc.h>
  31 #include "mdpy-defs.h"
  32
  33 #define MDPY_NAME               "mdpy"
  34 #define MDPY_CLASS_NAME         "mdpy"
  35
  36 #define MDPY_CONFIG_SPACE_SIZE  0xff
  37 #define MDPY_MEMORY_BAR_OFFSET  PAGE_SIZE
  38 #define MDPY_DISPLAY_REGION     16
  39
  40 #define STORE_LE16(addr, val)   (*(u16 *)addr = val)
  41 #define STORE_LE32(addr, val)   (*(u32 *)addr = val)
  42
  43
  44 MODULE_LICENSE("GPL v2");
  45
  46 static int max_devices = 4;
  47 module_param_named(count, max_devices, int, 0444);
  48 MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices");
  49
  50
  51 #define MDPY_TYPE_1 "vga"
  52 #define MDPY_TYPE_2 "xga"
  53 #define MDPY_TYPE_3 "hd"
  54
  55 static const struct mdpy_type {
  56         const char *name;
  57         u32 format;
  58         u32 bytepp;
  59         u32 width;
  60         u32 height;
  61 } mdpy_types[] = {
  62         {
  63                 .name   = MDPY_CLASS_NAME "-" MDPY_TYPE_1,
  64                 .format = DRM_FORMAT_XRGB8888,
  65                 .bytepp = 4,
  66                 .width  = 640,
  67                 .height = 480,
  68         }, {
  69                 .name   = MDPY_CLASS_NAME "-" MDPY_TYPE_2,
  70                 .format = DRM_FORMAT_XRGB8888,
  71                 .bytepp = 4,
  72                 .width  = 1024,
  73                 .height = 768,
  74         }, {
  75                 .name   = MDPY_CLASS_NAME "-" MDPY_TYPE_3,
  76                 .format = DRM_FORMAT_XRGB8888,
  77                 .bytepp = 4,
  78                 .width  = 1920,
  79                 .height = 1080,
  80         },
  81 };
  82
  83 static dev_t            mdpy_devt;
  84 static struct class     *mdpy_class;
  85 static struct cdev      mdpy_cdev;
  86 static struct device    mdpy_dev;
  87 static u32              mdpy_count;
  88
  89 /* State of each mdev device */
  90 struct mdev_state {
  91         u8 *vconfig;
  92         u32 bar_mask;
  93         struct mutex ops_lock;
  94         struct mdev_device *mdev;
  95         struct vfio_device_info dev_info;
  96
  97         const struct mdpy_type *type;
  98         u32 memsize;
  99         void *memblk;
 100 };
 101
 102 static const struct mdpy_type *mdpy_find_type(struct kobject *kobj)
 103 {
 104         int i;
 105
 106         for (i = 0; i < ARRAY_SIZE(mdpy_types); i++)
 107                 if (strcmp(mdpy_types[i].name, kobj->name) == 0)
 108                         return mdpy_types + i;
 109         return NULL;
 110 }
 111
 112 static void mdpy_create_config_space(struct mdev_state *mdev_state)
 113 {
 114         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
 115                    MDPY_PCI_VENDOR_ID);
 116         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
 117                    MDPY_PCI_DEVICE_ID);
 118         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
 119                    MDPY_PCI_SUBVENDOR_ID);
 120         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
 121                    MDPY_PCI_SUBDEVICE_ID);
 122
 123         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
 124                    PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
 125         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS],
 126                    PCI_STATUS_CAP_LIST);
 127         STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
 128                    PCI_CLASS_DISPLAY_OTHER);
 129         mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
 130
 131         STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
 132                    PCI_BASE_ADDRESS_SPACE_MEMORY |
 133                    PCI_BASE_ADDRESS_MEM_TYPE_32  |
 134                    PCI_BASE_ADDRESS_MEM_PREFETCH);
 135         mdev_state->bar_mask = ~(mdev_state->memsize) + 1;
 136
 137         /* vendor specific capability for the config registers */
 138         mdev_state->vconfig[PCI_CAPABILITY_LIST]       = MDPY_VENDORCAP_OFFSET;
 139         mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */
 140         mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */
 141         mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE;
 142         STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET],
 143                    mdev_state->type->format);
 144         STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET],
 145                    mdev_state->type->width);
 146         STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET],
 147                    mdev_state->type->height);
 148 }
 149
 150 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
 151                                  char *buf, u32 count)
 152 {
 153         struct device *dev = mdev_dev(mdev_state->mdev);
 154         u32 cfg_addr;
 155
 156         switch (offset) {
 157         case PCI_BASE_ADDRESS_0:
 158                 cfg_addr = *(u32 *)buf;
 159
 160                 if (cfg_addr == 0xffffffff) {
 161                         cfg_addr = (cfg_addr & mdev_state->bar_mask);
 162                 } else {
 163                         cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
 164                         if (cfg_addr)
 165                                 dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr);
 166                 }
 167
 168                 cfg_addr |= (mdev_state->vconfig[offset] &
 169                              ~PCI_BASE_ADDRESS_MEM_MASK);
 170                 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
 171                 break;
 172         }
 173 }
 174
 175 static ssize_t mdev_access(struct mdev_device *mdev, char *buf, size_t count,
 176                            loff_t pos, bool is_write)
 177 {
 178         struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
 179         struct device *dev = mdev_dev(mdev);
 180         int ret = 0;
 181
 182         mutex_lock(&mdev_state->ops_lock);
 183
 184         if (pos < MDPY_CONFIG_SPACE_SIZE) {
 185                 if (is_write)
 186                         handle_pci_cfg_write(mdev_state, pos, buf, count);
 187                 else
 188                         memcpy(buf, (mdev_state->vconfig + pos), count);
 189
 190         } else if ((pos >= MDPY_MEMORY_BAR_OFFSET) &&
 191                    (pos + count <=
 192                     MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) {
 193                 pos -= MDPY_MEMORY_BAR_OFFSET;
 194                 if (is_write)
 195                         memcpy(mdev_state->memblk, buf, count);
 196                 else
 197                         memcpy(buf, mdev_state->memblk, count);
 198
 199         } else {
 200                 dev_info(dev, "%s: %s @0x%llx (unhandled)\n",
 201                          __func__, is_write ? "WR" : "RD", pos);
 202                 ret = -1;
 203                 goto accessfailed;
 204         }
 205
 206         ret = count;
 207
 208
 209 accessfailed:
 210         mutex_unlock(&mdev_state->ops_lock);
 211
 212         return ret;
 213 }
 214
 215 static int mdpy_reset(struct mdev_device *mdev)
 216 {
 217         struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
 218         u32 stride, i;
 219
 220         /* initialize with gray gradient */
 221         stride = mdev_state->type->width * mdev_state->type->bytepp;
 222         for (i = 0; i < mdev_state->type->height; i++)
 223                 memset(mdev_state->memblk + i * stride,
 224                        i * 255 / mdev_state->type->height,
 225                        stride);
 226         return 0;
 227 }
 228
 229 static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev)
 230 {
 231         const struct mdpy_type *type = mdpy_find_type(kobj);
 232         struct device *dev = mdev_dev(mdev);
 233         struct mdev_state *mdev_state;
 234         u32 fbsize;
 235
 236         if (mdpy_count >= max_devices)
 237                 return -ENOMEM;
 238
 239         mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
 240         if (mdev_state == NULL)
 241                 return -ENOMEM;
 242
 243         mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL);
 244         if (mdev_state->vconfig == NULL) {
 245                 kfree(mdev_state);
 246                 return -ENOMEM;
 247         }
 248
 249         if (!type)
 250                 type = &mdpy_types[0];
 251         fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp);
 252
 253         mdev_state->memblk = vmalloc_user(fbsize);
 254         if (!mdev_state->memblk) {
 255                 kfree(mdev_state->vconfig);
 256                 kfree(mdev_state);
 257                 return -ENOMEM;
 258         }
 259         dev_info(dev, "%s: %s (%dx%d)\n",
 260                  __func__, kobj->name, type->width, type->height);
 261
 262         mutex_init(&mdev_state->ops_lock);
 263         mdev_state->mdev = mdev;
 264         mdev_set_drvdata(mdev, mdev_state);
 265
 266         mdev_state->type    = type;
 267         mdev_state->memsize = fbsize;
 268         mdpy_create_config_space(mdev_state);
 269         mdpy_reset(mdev);
 270
 271         mdpy_count++;
 272         return 0;
 273 }
 274
 275 static int mdpy_remove(struct mdev_device *mdev)
 276 {
 277         struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
 278         struct device *dev = mdev_dev(mdev);
 279
 280         dev_info(dev, "%s\n", __func__);
 281
 282         mdev_set_drvdata(mdev, NULL);
 283         vfree(mdev_state->memblk);
 284         kfree(mdev_state->vconfig);
 285         kfree(mdev_state);
 286
 287         mdpy_count--;
 288         return 0;
 289 }
 290
 291 static ssize_t mdpy_read(struct mdev_device *mdev, char __user *buf,
 292                          size_t count, loff_t *ppos)
 293 {
 294         unsigned int done = 0;
 295         int ret;
 296
 297         while (count) {
 298                 size_t filled;
 299
 300                 if (count >= 4 && !(*ppos % 4)) {
 301                         u32 val;
 302
 303                         ret =  mdev_access(mdev, (char *)&val, sizeof(val),
 304                                            *ppos, false);
 305                         if (ret <= 0)
 306                                 goto read_err;
 307
 308                         if (copy_to_user(buf, &val, sizeof(val)))
 309                                 goto read_err;
 310
 311                         filled = 4;
 312                 } else if (count >= 2 && !(*ppos % 2)) {
 313                         u16 val;
 314
 315                         ret = mdev_access(mdev, (char *)&val, sizeof(val),
 316                                           *ppos, false);
 317                         if (ret <= 0)
 318                                 goto read_err;
 319
 320                         if (copy_to_user(buf, &val, sizeof(val)))
 321                                 goto read_err;
 322
 323                         filled = 2;
 324                 } else {
 325                         u8 val;
 326
 327                         ret = mdev_access(mdev, (char *)&val, sizeof(val),
 328                                           *ppos, false);
 329                         if (ret <= 0)
 330                                 goto read_err;
 331
 332                         if (copy_to_user(buf, &val, sizeof(val)))
 333                                 goto read_err;
 334
 335                         filled = 1;
 336                 }
 337
 338                 count -= filled;
 339                 done += filled;
 340                 *ppos += filled;
 341                 buf += filled;
 342         }
 343
 344         return done;
 345
 346 read_err:
 347         return -EFAULT;
 348 }
 349
 350 static ssize_t mdpy_write(struct mdev_device *mdev, const char __user *buf,
 351                           size_t count, loff_t *ppos)
 352 {
 353         unsigned int done = 0;
 354         int ret;
 355
 356         while (count) {
 357                 size_t filled;
 358
 359                 if (count >= 4 && !(*ppos % 4)) {
 360                         u32 val;
 361
 362                         if (copy_from_user(&val, buf, sizeof(val)))
 363                                 goto write_err;
 364
 365                         ret = mdev_access(mdev, (char *)&val, sizeof(val),
 366                                           *ppos, true);
 367                         if (ret <= 0)
 368                                 goto write_err;
 369
 370                         filled = 4;
 371                 } else if (count >= 2 && !(*ppos % 2)) {
 372                         u16 val;
 373
 374                         if (copy_from_user(&val, buf, sizeof(val)))
 375                                 goto write_err;
 376
 377                         ret = mdev_access(mdev, (char *)&val, sizeof(val),
 378                                           *ppos, true);
 379                         if (ret <= 0)
 380                                 goto write_err;
 381
 382                         filled = 2;
 383                 } else {
 384                         u8 val;
 385
 386                         if (copy_from_user(&val, buf, sizeof(val)))
 387                                 goto write_err;
 388
 389                         ret = mdev_access(mdev, (char *)&val, sizeof(val),
 390                                           *ppos, true);
 391                         if (ret <= 0)
 392                                 goto write_err;
 393
 394                         filled = 1;
 395                 }
 396                 count -= filled;
 397                 done += filled;
 398                 *ppos += filled;
 399                 buf += filled;
 400         }
 401
 402         return done;
 403 write_err:
 404         return -EFAULT;
 405 }
 406
 407 static int mdpy_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
 408 {
 409         struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
 410
 411         if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
 412                 return -EINVAL;
 413         if (vma->vm_end < vma->vm_start)
 414                 return -EINVAL;
 415         if (vma->vm_end - vma->vm_start > mdev_state->memsize)
 416                 return -EINVAL;
 417         if ((vma->vm_flags & VM_SHARED) == 0)
 418                 return -EINVAL;
 419
 420         return remap_vmalloc_range_partial(vma, vma->vm_start,
 421                                            mdev_state->memblk,
 422                                            vma->vm_end - vma->vm_start);
 423 }
 424
 425 static int mdpy_get_region_info(struct mdev_device *mdev,
 426                                 struct vfio_region_info *region_info,
 427                                 u16 *cap_type_id, void **cap_type)
 428 {
 429         struct mdev_state *mdev_state;
 430
 431         mdev_state = mdev_get_drvdata(mdev);
 432         if (!mdev_state)
 433                 return -EINVAL;
 434
 435         if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
 436             region_info->index != MDPY_DISPLAY_REGION)
 437                 return -EINVAL;
 438
 439         switch (region_info->index) {
 440         case VFIO_PCI_CONFIG_REGION_INDEX:
 441                 region_info->offset = 0;
 442                 region_info->size   = MDPY_CONFIG_SPACE_SIZE;
 443                 region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
 444                                        VFIO_REGION_INFO_FLAG_WRITE);
 445                 break;
 446         case VFIO_PCI_BAR0_REGION_INDEX:
 447         case MDPY_DISPLAY_REGION:
 448                 region_info->offset = MDPY_MEMORY_BAR_OFFSET;
 449                 region_info->size   = mdev_state->memsize;
 450                 region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
 451                                        VFIO_REGION_INFO_FLAG_WRITE |
 452                                        VFIO_REGION_INFO_FLAG_MMAP);
 453                 break;
 454         default:
 455                 region_info->size   = 0;
 456                 region_info->offset = 0;
 457                 region_info->flags  = 0;
 458         }
 459
 460         return 0;
 461 }
 462
 463 static int mdpy_get_irq_info(struct mdev_device *mdev,
 464                              struct vfio_irq_info *irq_info)
 465 {
 466         irq_info->count = 0;
 467         return 0;
 468 }
 469
 470 static int mdpy_get_device_info(struct mdev_device *mdev,
 471                                 struct vfio_device_info *dev_info)
 472 {
 473         dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
 474         dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
 475         dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
 476         return 0;
 477 }
 478
 479 static int mdpy_query_gfx_plane(struct mdev_device *mdev,
 480                                 struct vfio_device_gfx_plane_info *plane)
 481 {
 482         struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
 483
 484         if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
 485                 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
 486                                      VFIO_GFX_PLANE_TYPE_REGION))
 487                         return 0;
 488                 return -EINVAL;
 489         }
 490
 491         if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
 492                 return -EINVAL;
 493
 494         plane->drm_format     = mdev_state->type->format;
 495         plane->width          = mdev_state->type->width;
 496         plane->height         = mdev_state->type->height;
 497         plane->stride         = (mdev_state->type->width *
 498                                  mdev_state->type->bytepp);
 499         plane->size           = mdev_state->memsize;
 500         plane->region_index   = MDPY_DISPLAY_REGION;
 501
 502         /* unused */
 503         plane->drm_format_mod = 0;
 504         plane->x_pos          = 0;
 505         plane->y_pos          = 0;
 506         plane->x_hot          = 0;
 507         plane->y_hot          = 0;
 508
 509         return 0;
 510 }
 511
 512 static long mdpy_ioctl(struct mdev_device *mdev, unsigned int cmd,
 513                        unsigned long arg)
 514 {
 515         int ret = 0;
 516         unsigned long minsz;
 517         struct mdev_state *mdev_state;
 518
 519         mdev_state = mdev_get_drvdata(mdev);
 520
 521         switch (cmd) {
 522         case VFIO_DEVICE_GET_INFO:
 523         {
 524                 struct vfio_device_info info;
 525
 526                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 527
 528                 if (copy_from_user(&info, (void __user *)arg, minsz))
 529                         return -EFAULT;
 530
 531                 if (info.argsz < minsz)
 532                         return -EINVAL;
 533
 534                 ret = mdpy_get_device_info(mdev, &info);
 535                 if (ret)
 536                         return ret;
 537
 538                 memcpy(&mdev_state->dev_info, &info, sizeof(info));
 539
 540                 if (copy_to_user((void __user *)arg, &info, minsz))
 541                         return -EFAULT;
 542
 543                 return 0;
 544         }
 545         case VFIO_DEVICE_GET_REGION_INFO:
 546         {
 547                 struct vfio_region_info info;
 548                 u16 cap_type_id = 0;
 549                 void *cap_type = NULL;
 550
 551                 minsz = offsetofend(struct vfio_region_info, offset);
 552
 553                 if (copy_from_user(&info, (void __user *)arg, minsz))
 554                         return -EFAULT;
 555
 556                 if (info.argsz < minsz)
 557                         return -EINVAL;
 558
 559                 ret = mdpy_get_region_info(mdev, &info, &cap_type_id,
 560                                            &cap_type);
 561                 if (ret)
 562                         return ret;
 563
 564                 if (copy_to_user((void __user *)arg, &info, minsz))
 565                         return -EFAULT;
 566
 567                 return 0;
 568         }
 569
 570         case VFIO_DEVICE_GET_IRQ_INFO:
 571         {
 572                 struct vfio_irq_info info;
 573
 574                 minsz = offsetofend(struct vfio_irq_info, count);
 575
 576                 if (copy_from_user(&info, (void __user *)arg, minsz))
 577                         return -EFAULT;
 578
 579                 if ((info.argsz < minsz) ||
 580                     (info.index >= mdev_state->dev_info.num_irqs))
 581                         return -EINVAL;
 582
 583                 ret = mdpy_get_irq_info(mdev, &info);
 584                 if (ret)
 585                         return ret;
 586
 587                 if (copy_to_user((void __user *)arg, &info, minsz))
 588                         return -EFAULT;
 589
 590                 return 0;
 591         }
 592
 593         case VFIO_DEVICE_QUERY_GFX_PLANE:
 594         {
 595                 struct vfio_device_gfx_plane_info plane;
 596
 597                 minsz = offsetofend(struct vfio_device_gfx_plane_info,
 598                                     region_index);
 599
 600                 if (copy_from_user(&plane, (void __user *)arg, minsz))
 601                         return -EFAULT;
 602
 603                 if (plane.argsz < minsz)
 604                         return -EINVAL;
 605
 606                 ret = mdpy_query_gfx_plane(mdev, &plane);
 607                 if (ret)
 608                         return ret;
 609
 610                 if (copy_to_user((void __user *)arg, &plane, minsz))
 611                         return -EFAULT;
 612
 613                 return 0;
 614         }
 615
 616         case VFIO_DEVICE_SET_IRQS:
 617                 return -EINVAL;
 618
 619         case VFIO_DEVICE_RESET:
 620                 return mdpy_reset(mdev);
 621         }
 622         return -ENOTTY;
 623 }
 624
 625 static int mdpy_open(struct mdev_device *mdev)
 626 {
 627         if (!try_module_get(THIS_MODULE))
 628                 return -ENODEV;
 629
 630         return 0;
 631 }
 632
 633 static void mdpy_close(struct mdev_device *mdev)
 634 {
 635         module_put(THIS_MODULE);
 636 }
 637
 638 static ssize_t
 639 resolution_show(struct device *dev, struct device_attribute *attr,
 640                 char *buf)
 641 {
 642         struct mdev_device *mdev = mdev_from_dev(dev);
 643         struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
 644
 645         return sprintf(buf, "%dx%d\n",
 646                        mdev_state->type->width,
 647                        mdev_state->type->height);
 648 }
 649 static DEVICE_ATTR_RO(resolution);
 650
 651 static struct attribute *mdev_dev_attrs[] = {
 652         &dev_attr_resolution.attr,
 653         NULL,
 654 };
 655
 656 static const struct attribute_group mdev_dev_group = {
 657         .name  = "vendor",
 658         .attrs = mdev_dev_attrs,
 659 };
 660
 661 const struct attribute_group *mdev_dev_groups[] = {
 662         &mdev_dev_group,
 663         NULL,
 664 };
 665
 666 static ssize_t
 667 name_show(struct kobject *kobj, struct device *dev, char *buf)
 668 {
 669         return sprintf(buf, "%s\n", kobj->name);
 670 }
 671 MDEV_TYPE_ATTR_RO(name);
 672
 673 static ssize_t
 674 description_show(struct kobject *kobj, struct device *dev, char *buf)
 675 {
 676         const struct mdpy_type *type = mdpy_find_type(kobj);
 677
 678         return sprintf(buf, "virtual display, %dx%d framebuffer\n",
 679                        type ? type->width  : 0,
 680                        type ? type->height : 0);
 681 }
 682 MDEV_TYPE_ATTR_RO(description);
 683
 684 static ssize_t
 685 available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
 686 {
 687         return sprintf(buf, "%d\n", max_devices - mdpy_count);
 688 }
 689 MDEV_TYPE_ATTR_RO(available_instances);
 690
 691 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
 692                                char *buf)
 693 {
 694         return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
 695 }
 696 MDEV_TYPE_ATTR_RO(device_api);
 697
 698 static struct attribute *mdev_types_attrs[] = {
 699         &mdev_type_attr_name.attr,
 700         &mdev_type_attr_description.attr,
 701         &mdev_type_attr_device_api.attr,
 702         &mdev_type_attr_available_instances.attr,
 703         NULL,
 704 };
 705
 706 static struct attribute_group mdev_type_group1 = {
 707         .name  = MDPY_TYPE_1,
 708         .attrs = mdev_types_attrs,
 709 };
 710
 711 static struct attribute_group mdev_type_group2 = {
 712         .name  = MDPY_TYPE_2,
 713         .attrs = mdev_types_attrs,
 714 };
 715
 716 static struct attribute_group mdev_type_group3 = {
 717         .name  = MDPY_TYPE_3,
 718         .attrs = mdev_types_attrs,
 719 };
 720
 721 static struct attribute_group *mdev_type_groups[] = {
 722         &mdev_type_group1,
 723         &mdev_type_group2,
 724         &mdev_type_group3,
 725         NULL,
 726 };
 727
 728 static const struct mdev_parent_ops mdev_fops = {
 729         .owner                  = THIS_MODULE,
 730         .mdev_attr_groups       = mdev_dev_groups,
 731         .supported_type_groups  = mdev_type_groups,
 732         .create                 = mdpy_create,
 733         .remove                 = mdpy_remove,
 734         .open                   = mdpy_open,
 735         .release                = mdpy_close,
 736         .read                   = mdpy_read,
 737         .write                  = mdpy_write,
 738         .ioctl                  = mdpy_ioctl,
 739         .mmap                   = mdpy_mmap,
 740 };
 741
 742 static const struct file_operations vd_fops = {
 743         .owner          = THIS_MODULE,
 744 };
 745
 746 static void mdpy_device_release(struct device *dev)
 747 {
 748         /* nothing */
 749 }
 750
 751 static int __init mdpy_dev_init(void)
 752 {
 753         int ret = 0;
 754
 755         ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME);
 756         if (ret < 0) {
 757                 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
 758                 return ret;
 759         }
 760         cdev_init(&mdpy_cdev, &vd_fops);
 761         cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1);
 762         pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
 763
 764         mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME);
 765         if (IS_ERR(mdpy_class)) {
 766                 pr_err("Error: failed to register mdpy_dev class\n");
 767                 ret = PTR_ERR(mdpy_class);
 768                 goto failed1;
 769         }
 770         mdpy_dev.class = mdpy_class;
 771         mdpy_dev.release = mdpy_device_release;
 772         dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
 773
 774         ret = device_register(&mdpy_dev);
 775         if (ret)
 776                 goto failed2;
 777
 778         ret = mdev_register_device(&mdpy_dev, &mdev_fops);
 779         if (ret)
 780                 goto failed3;
 781
 782         return 0;
 783
 784 failed3:
 785         device_unregister(&mdpy_dev);
 786 failed2:
 787         class_destroy(mdpy_class);
 788 failed1:
 789         cdev_del(&mdpy_cdev);
 790         unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
 791         return ret;
 792 }
 793
 794 static void __exit mdpy_dev_exit(void)
 795 {
 796         mdpy_dev.bus = NULL;
 797         mdev_unregister_device(&mdpy_dev);
 798
 799         device_unregister(&mdpy_dev);
 800         cdev_del(&mdpy_cdev);
 801         unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
 802         class_destroy(mdpy_class);
 803         mdpy_class = NULL;
 804 }
 805
 806 module_init(mdpy_dev_init)
 807 module_exit(mdpy_dev_exit)