drivers/video/fbdev/hyperv_fb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2012, Microsoft Corporation.
   4  *
   5  * Author:
   6  *   Haiyang Zhang <haiyangz@microsoft.com>
   7  */
   8
   9 /*
  10  * Hyper-V Synthetic Video Frame Buffer Driver
  11  *
  12  * This is the driver for the Hyper-V Synthetic Video, which supports
  13  * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
  14  * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
  15  * or earlier.
  16  *
  17  * It also solves the double mouse cursor issue of the emulated video mode.
  18  *
  19  * The default screen resolution is 1152x864, which may be changed by a
  20  * kernel parameter:
  21  *     video=hyperv_fb:<width>x<height>
  22  *     For example: video=hyperv_fb:1280x1024
  23  *
  24  * Portrait orientation is also supported:
  25  *     For example: video=hyperv_fb:864x1152
  26  *
  27  * When a Windows 10 RS5+ host is used, the virtual machine screen
  28  * resolution is obtained from the host. The "video=hyperv_fb" option is
  29  * not needed, but still can be used to overwrite what the host specifies.
  30  * The VM resolution on the host could be set by executing the powershell
  31  * "set-vmvideo" command. For example
  32  *     set-vmvideo -vmname name -horizontalresolution:1920 \
  33  * -verticalresolution:1200 -resolutiontype single
  34  */
  35
  36 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  37
  38 #include <linux/module.h>
  39 #include <linux/kernel.h>
  40 #include <linux/init.h>
  41 #include <linux/completion.h>
  42 #include <linux/fb.h>
  43 #include <linux/pci.h>
  44 #include <linux/efi.h>
  45 #include <linux/console.h>
  46
  47 #include <linux/hyperv.h>
  48
  49
  50 /* Hyper-V Synthetic Video Protocol definitions and structures */
  51 #define MAX_VMBUS_PKT_SIZE 0x4000
  52
  53 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
  54 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
  55 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
  56 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
  57
  58 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
  59 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
  60
  61 #define SYNTHVID_DEPTH_WIN7 16
  62 #define SYNTHVID_DEPTH_WIN8 32
  63
  64 #define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
  65 #define SYNTHVID_WIDTH_MAX_WIN7 1600
  66 #define SYNTHVID_HEIGHT_MAX_WIN7 1200
  67
  68 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
  69
  70 #define PCI_VENDOR_ID_MICROSOFT 0x1414
  71 #define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
  72
  73
  74 enum pipe_msg_type {
  75         PIPE_MSG_INVALID,
  76         PIPE_MSG_DATA,
  77         PIPE_MSG_MAX
  78 };
  79
  80 struct pipe_msg_hdr {
  81         u32 type;
  82         u32 size; /* size of message after this field */
  83 } __packed;
  84
  85
  86 enum synthvid_msg_type {
  87         SYNTHVID_ERROR                  = 0,
  88         SYNTHVID_VERSION_REQUEST        = 1,
  89         SYNTHVID_VERSION_RESPONSE       = 2,
  90         SYNTHVID_VRAM_LOCATION          = 3,
  91         SYNTHVID_VRAM_LOCATION_ACK      = 4,
  92         SYNTHVID_SITUATION_UPDATE       = 5,
  93         SYNTHVID_SITUATION_UPDATE_ACK   = 6,
  94         SYNTHVID_POINTER_POSITION       = 7,
  95         SYNTHVID_POINTER_SHAPE          = 8,
  96         SYNTHVID_FEATURE_CHANGE         = 9,
  97         SYNTHVID_DIRT                   = 10,
  98         SYNTHVID_RESOLUTION_REQUEST     = 13,
  99         SYNTHVID_RESOLUTION_RESPONSE    = 14,
 100
 101         SYNTHVID_MAX                    = 15
 102 };
 103
 104 #define         SYNTHVID_EDID_BLOCK_SIZE        128
 105 #define         SYNTHVID_MAX_RESOLUTION_COUNT   64
 106
 107 struct hvd_screen_info {
 108         u16 width;
 109         u16 height;
 110 } __packed;
 111
 112 struct synthvid_msg_hdr {
 113         u32 type;
 114         u32 size;  /* size of this header + payload after this field*/
 115 } __packed;
 116
 117 struct synthvid_version_req {
 118         u32 version;
 119 } __packed;
 120
 121 struct synthvid_version_resp {
 122         u32 version;
 123         u8 is_accepted;
 124         u8 max_video_outputs;
 125 } __packed;
 126
 127 struct synthvid_supported_resolution_req {
 128         u8 maximum_resolution_count;
 129 } __packed;
 130
 131 struct synthvid_supported_resolution_resp {
 132         u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
 133         u8 resolution_count;
 134         u8 default_resolution_index;
 135         u8 is_standard;
 136         struct hvd_screen_info
 137                 supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
 138 } __packed;
 139
 140 struct synthvid_vram_location {
 141         u64 user_ctx;
 142         u8 is_vram_gpa_specified;
 143         u64 vram_gpa;
 144 } __packed;
 145
 146 struct synthvid_vram_location_ack {
 147         u64 user_ctx;
 148 } __packed;
 149
 150 struct video_output_situation {
 151         u8 active;
 152         u32 vram_offset;
 153         u8 depth_bits;
 154         u32 width_pixels;
 155         u32 height_pixels;
 156         u32 pitch_bytes;
 157 } __packed;
 158
 159 struct synthvid_situation_update {
 160         u64 user_ctx;
 161         u8 video_output_count;
 162         struct video_output_situation video_output[1];
 163 } __packed;
 164
 165 struct synthvid_situation_update_ack {
 166         u64 user_ctx;
 167 } __packed;
 168
 169 struct synthvid_pointer_position {
 170         u8 is_visible;
 171         u8 video_output;
 172         s32 image_x;
 173         s32 image_y;
 174 } __packed;
 175
 176
 177 #define CURSOR_MAX_X 96
 178 #define CURSOR_MAX_Y 96
 179 #define CURSOR_ARGB_PIXEL_SIZE 4
 180 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
 181 #define CURSOR_COMPLETE (-1)
 182
 183 struct synthvid_pointer_shape {
 184         u8 part_idx;
 185         u8 is_argb;
 186         u32 width; /* CURSOR_MAX_X at most */
 187         u32 height; /* CURSOR_MAX_Y at most */
 188         u32 hot_x; /* hotspot relative to upper-left of pointer image */
 189         u32 hot_y;
 190         u8 data[4];
 191 } __packed;
 192
 193 struct synthvid_feature_change {
 194         u8 is_dirt_needed;
 195         u8 is_ptr_pos_needed;
 196         u8 is_ptr_shape_needed;
 197         u8 is_situ_needed;
 198 } __packed;
 199
 200 struct rect {
 201         s32 x1, y1; /* top left corner */
 202         s32 x2, y2; /* bottom right corner, exclusive */
 203 } __packed;
 204
 205 struct synthvid_dirt {
 206         u8 video_output;
 207         u8 dirt_count;
 208         struct rect rect[1];
 209 } __packed;
 210
 211 struct synthvid_msg {
 212         struct pipe_msg_hdr pipe_hdr;
 213         struct synthvid_msg_hdr vid_hdr;
 214         union {
 215                 struct synthvid_version_req ver_req;
 216                 struct synthvid_version_resp ver_resp;
 217                 struct synthvid_vram_location vram;
 218                 struct synthvid_vram_location_ack vram_ack;
 219                 struct synthvid_situation_update situ;
 220                 struct synthvid_situation_update_ack situ_ack;
 221                 struct synthvid_pointer_position ptr_pos;
 222                 struct synthvid_pointer_shape ptr_shape;
 223                 struct synthvid_feature_change feature_chg;
 224                 struct synthvid_dirt dirt;
 225                 struct synthvid_supported_resolution_req resolution_req;
 226                 struct synthvid_supported_resolution_resp resolution_resp;
 227         };
 228 } __packed;
 229
 230
 231
 232 /* FB driver definitions and structures */
 233 #define HVFB_WIDTH 1152 /* default screen width */
 234 #define HVFB_HEIGHT 864 /* default screen height */
 235 #define HVFB_WIDTH_MIN 640
 236 #define HVFB_HEIGHT_MIN 480
 237
 238 #define RING_BUFSIZE (256 * 1024)
 239 #define VSP_TIMEOUT (10 * HZ)
 240 #define HVFB_UPDATE_DELAY (HZ / 20)
 241 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
 242
 243 struct hvfb_par {
 244         struct fb_info *info;
 245         struct resource *mem;
 246         bool fb_ready; /* fb device is ready */
 247         struct completion wait;
 248         u32 synthvid_version;
 249
 250         struct delayed_work dwork;
 251         bool update;
 252         bool update_saved; /* The value of 'update' before hibernation */
 253
 254         u32 pseudo_palette[16];
 255         u8 init_buf[MAX_VMBUS_PKT_SIZE];
 256         u8 recv_buf[MAX_VMBUS_PKT_SIZE];
 257
 258         /* If true, the VSC notifies the VSP on every framebuffer change */
 259         bool synchronous_fb;
 260
 261         struct notifier_block hvfb_panic_nb;
 262
 263         /* Memory for deferred IO and frame buffer itself */
 264         unsigned char *dio_vp;
 265         unsigned char *mmio_vp;
 266         unsigned long mmio_pp;
 267
 268         /* Dirty rectangle, protected by delayed_refresh_lock */
 269         int x1, y1, x2, y2;
 270         bool delayed_refresh;
 271         spinlock_t delayed_refresh_lock;
 272 };
 273
 274 static uint screen_width = HVFB_WIDTH;
 275 static uint screen_height = HVFB_HEIGHT;
 276 static uint screen_width_max = HVFB_WIDTH;
 277 static uint screen_height_max = HVFB_HEIGHT;
 278 static uint screen_depth;
 279 static uint screen_fb_size;
 280 static uint dio_fb_size; /* FB size for deferred IO */
 281
 282 /* Send message to Hyper-V host */
 283 static inline int synthvid_send(struct hv_device *hdev,
 284                                 struct synthvid_msg *msg)
 285 {
 286         static atomic64_t request_id = ATOMIC64_INIT(0);
 287         int ret;
 288
 289         msg->pipe_hdr.type = PIPE_MSG_DATA;
 290         msg->pipe_hdr.size = msg->vid_hdr.size;
 291
 292         ret = vmbus_sendpacket(hdev->channel, msg,
 293                                msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
 294                                atomic64_inc_return(&request_id),
 295                                VM_PKT_DATA_INBAND, 0);
 296
 297         if (ret)
 298                 pr_err("Unable to send packet via vmbus\n");
 299
 300         return ret;
 301 }
 302
 303
 304 /* Send screen resolution info to host */
 305 static int synthvid_send_situ(struct hv_device *hdev)
 306 {
 307         struct fb_info *info = hv_get_drvdata(hdev);
 308         struct synthvid_msg msg;
 309
 310         if (!info)
 311                 return -ENODEV;
 312
 313         memset(&msg, 0, sizeof(struct synthvid_msg));
 314
 315         msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
 316         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 317                 sizeof(struct synthvid_situation_update);
 318         msg.situ.user_ctx = 0;
 319         msg.situ.video_output_count = 1;
 320         msg.situ.video_output[0].active = 1;
 321         msg.situ.video_output[0].vram_offset = 0;
 322         msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
 323         msg.situ.video_output[0].width_pixels = info->var.xres;
 324         msg.situ.video_output[0].height_pixels = info->var.yres;
 325         msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
 326
 327         synthvid_send(hdev, &msg);
 328
 329         return 0;
 330 }
 331
 332 /* Send mouse pointer info to host */
 333 static int synthvid_send_ptr(struct hv_device *hdev)
 334 {
 335         struct synthvid_msg msg;
 336
 337         memset(&msg, 0, sizeof(struct synthvid_msg));
 338         msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
 339         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 340                 sizeof(struct synthvid_pointer_position);
 341         msg.ptr_pos.is_visible = 1;
 342         msg.ptr_pos.video_output = 0;
 343         msg.ptr_pos.image_x = 0;
 344         msg.ptr_pos.image_y = 0;
 345         synthvid_send(hdev, &msg);
 346
 347         memset(&msg, 0, sizeof(struct synthvid_msg));
 348         msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
 349         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 350                 sizeof(struct synthvid_pointer_shape);
 351         msg.ptr_shape.part_idx = CURSOR_COMPLETE;
 352         msg.ptr_shape.is_argb = 1;
 353         msg.ptr_shape.width = 1;
 354         msg.ptr_shape.height = 1;
 355         msg.ptr_shape.hot_x = 0;
 356         msg.ptr_shape.hot_y = 0;
 357         msg.ptr_shape.data[0] = 0;
 358         msg.ptr_shape.data[1] = 1;
 359         msg.ptr_shape.data[2] = 1;
 360         msg.ptr_shape.data[3] = 1;
 361         synthvid_send(hdev, &msg);
 362
 363         return 0;
 364 }
 365
 366 /* Send updated screen area (dirty rectangle) location to host */
 367 static int
 368 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
 369 {
 370         struct hv_device *hdev = device_to_hv_device(info->device);
 371         struct synthvid_msg msg;
 372
 373         memset(&msg, 0, sizeof(struct synthvid_msg));
 374         if (x2 == INT_MAX)
 375                 x2 = info->var.xres;
 376         if (y2 == INT_MAX)
 377                 y2 = info->var.yres;
 378
 379         msg.vid_hdr.type = SYNTHVID_DIRT;
 380         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 381                 sizeof(struct synthvid_dirt);
 382         msg.dirt.video_output = 0;
 383         msg.dirt.dirt_count = 1;
 384         msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
 385         msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
 386         msg.dirt.rect[0].x2 =
 387                 (x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
 388         msg.dirt.rect[0].y2 =
 389                 (y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
 390
 391         synthvid_send(hdev, &msg);
 392
 393         return 0;
 394 }
 395
 396 static void hvfb_docopy(struct hvfb_par *par,
 397                         unsigned long offset,
 398                         unsigned long size)
 399 {
 400         if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
 401             size == 0 || offset >= dio_fb_size)
 402                 return;
 403
 404         if (offset + size > dio_fb_size)
 405                 size = dio_fb_size - offset;
 406
 407         memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
 408 }
 409
 410 /* Deferred IO callback */
 411 static void synthvid_deferred_io(struct fb_info *p,
 412                                  struct list_head *pagelist)
 413 {
 414         struct hvfb_par *par = p->par;
 415         struct page *page;
 416         unsigned long start, end;
 417         int y1, y2, miny, maxy;
 418
 419         miny = INT_MAX;
 420         maxy = 0;
 421
 422         /*
 423          * Merge dirty pages. It is possible that last page cross
 424          * over the end of frame buffer row yres. This is taken care of
 425          * in synthvid_update function by clamping the y2
 426          * value to yres.
 427          */
 428         list_for_each_entry(page, pagelist, lru) {
 429                 start = page->index << PAGE_SHIFT;
 430                 end = start + PAGE_SIZE - 1;
 431                 y1 = start / p->fix.line_length;
 432                 y2 = end / p->fix.line_length;
 433                 miny = min_t(int, miny, y1);
 434                 maxy = max_t(int, maxy, y2);
 435
 436                 /* Copy from dio space to mmio address */
 437                 if (par->fb_ready)
 438                         hvfb_docopy(par, start, PAGE_SIZE);
 439         }
 440
 441         if (par->fb_ready && par->update)
 442                 synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
 443 }
 444
 445 static struct fb_deferred_io synthvid_defio = {
 446         .delay          = HZ / 20,
 447         .deferred_io    = synthvid_deferred_io,
 448 };
 449
 450 /*
 451  * Actions on received messages from host:
 452  * Complete the wait event.
 453  * Or, reply with screen and cursor info.
 454  */
 455 static void synthvid_recv_sub(struct hv_device *hdev)
 456 {
 457         struct fb_info *info = hv_get_drvdata(hdev);
 458         struct hvfb_par *par;
 459         struct synthvid_msg *msg;
 460
 461         if (!info)
 462                 return;
 463
 464         par = info->par;
 465         msg = (struct synthvid_msg *)par->recv_buf;
 466
 467         /* Complete the wait event */
 468         if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
 469             msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
 470             msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
 471                 memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
 472                 complete(&par->wait);
 473                 return;
 474         }
 475
 476         /* Reply with screen and cursor info */
 477         if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
 478                 if (par->fb_ready) {
 479                         synthvid_send_ptr(hdev);
 480                         synthvid_send_situ(hdev);
 481                 }
 482
 483                 par->update = msg->feature_chg.is_dirt_needed;
 484                 if (par->update)
 485                         schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
 486         }
 487 }
 488
 489 /* Receive callback for messages from the host */
 490 static void synthvid_receive(void *ctx)
 491 {
 492         struct hv_device *hdev = ctx;
 493         struct fb_info *info = hv_get_drvdata(hdev);
 494         struct hvfb_par *par;
 495         struct synthvid_msg *recv_buf;
 496         u32 bytes_recvd;
 497         u64 req_id;
 498         int ret;
 499
 500         if (!info)
 501                 return;
 502
 503         par = info->par;
 504         recv_buf = (struct synthvid_msg *)par->recv_buf;
 505
 506         do {
 507                 ret = vmbus_recvpacket(hdev->channel, recv_buf,
 508                                        MAX_VMBUS_PKT_SIZE,
 509                                        &bytes_recvd, &req_id);
 510                 if (bytes_recvd > 0 &&
 511                     recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
 512                         synthvid_recv_sub(hdev);
 513         } while (bytes_recvd > 0 && ret == 0);
 514 }
 515
 516 /* Check if the ver1 version is equal or greater than ver2 */
 517 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
 518 {
 519         if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
 520             (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
 521              SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
 522                 return true;
 523
 524         return false;
 525 }
 526
 527 /* Check synthetic video protocol version with the host */
 528 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
 529 {
 530         struct fb_info *info = hv_get_drvdata(hdev);
 531         struct hvfb_par *par = info->par;
 532         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
 533         int ret = 0;
 534         unsigned long t;
 535
 536         memset(msg, 0, sizeof(struct synthvid_msg));
 537         msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
 538         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 539                 sizeof(struct synthvid_version_req);
 540         msg->ver_req.version = ver;
 541         synthvid_send(hdev, msg);
 542
 543         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
 544         if (!t) {
 545                 pr_err("Time out on waiting version response\n");
 546                 ret = -ETIMEDOUT;
 547                 goto out;
 548         }
 549         if (!msg->ver_resp.is_accepted) {
 550                 ret = -ENODEV;
 551                 goto out;
 552         }
 553
 554         par->synthvid_version = ver;
 555         pr_info("Synthvid Version major %d, minor %d\n",
 556                 SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
 557
 558 out:
 559         return ret;
 560 }
 561
 562 /* Get current resolution from the host */
 563 static int synthvid_get_supported_resolution(struct hv_device *hdev)
 564 {
 565         struct fb_info *info = hv_get_drvdata(hdev);
 566         struct hvfb_par *par = info->par;
 567         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
 568         int ret = 0;
 569         unsigned long t;
 570         u8 index;
 571         int i;
 572
 573         memset(msg, 0, sizeof(struct synthvid_msg));
 574         msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
 575         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 576                 sizeof(struct synthvid_supported_resolution_req);
 577
 578         msg->resolution_req.maximum_resolution_count =
 579                 SYNTHVID_MAX_RESOLUTION_COUNT;
 580         synthvid_send(hdev, msg);
 581
 582         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
 583         if (!t) {
 584                 pr_err("Time out on waiting resolution response\n");
 585                         ret = -ETIMEDOUT;
 586                         goto out;
 587         }
 588
 589         if (msg->resolution_resp.resolution_count == 0) {
 590                 pr_err("No supported resolutions\n");
 591                 ret = -ENODEV;
 592                 goto out;
 593         }
 594
 595         index = msg->resolution_resp.default_resolution_index;
 596         if (index >= msg->resolution_resp.resolution_count) {
 597                 pr_err("Invalid resolution index: %d\n", index);
 598                 ret = -ENODEV;
 599                 goto out;
 600         }
 601
 602         for (i = 0; i < msg->resolution_resp.resolution_count; i++) {
 603                 screen_width_max = max_t(unsigned int, screen_width_max,
 604                     msg->resolution_resp.supported_resolution[i].width);
 605                 screen_height_max = max_t(unsigned int, screen_height_max,
 606                     msg->resolution_resp.supported_resolution[i].height);
 607         }
 608
 609         screen_width =
 610                 msg->resolution_resp.supported_resolution[index].width;
 611         screen_height =
 612                 msg->resolution_resp.supported_resolution[index].height;
 613
 614 out:
 615         return ret;
 616 }
 617
 618 /* Connect to VSP (Virtual Service Provider) on host */
 619 static int synthvid_connect_vsp(struct hv_device *hdev)
 620 {
 621         struct fb_info *info = hv_get_drvdata(hdev);
 622         struct hvfb_par *par = info->par;
 623         int ret;
 624
 625         ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
 626                          NULL, 0, synthvid_receive, hdev);
 627         if (ret) {
 628                 pr_err("Unable to open vmbus channel\n");
 629                 return ret;
 630         }
 631
 632         /* Negotiate the protocol version with host */
 633         switch (vmbus_proto_version) {
 634         case VERSION_WIN10:
 635         case VERSION_WIN10_V5:
 636                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
 637                 if (!ret)
 638                         break;
 639                 /* Fallthrough */
 640         case VERSION_WIN8:
 641         case VERSION_WIN8_1:
 642                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
 643                 if (!ret)
 644                         break;
 645                 /* Fallthrough */
 646         case VERSION_WS2008:
 647         case VERSION_WIN7:
 648                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
 649                 break;
 650         default:
 651                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
 652                 break;
 653         }
 654
 655         if (ret) {
 656                 pr_err("Synthetic video device version not accepted\n");
 657                 goto error;
 658         }
 659
 660         if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
 661                 screen_depth = SYNTHVID_DEPTH_WIN7;
 662         else
 663                 screen_depth = SYNTHVID_DEPTH_WIN8;
 664
 665         if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
 666                 ret = synthvid_get_supported_resolution(hdev);
 667                 if (ret)
 668                         pr_info("Failed to get supported resolution from host, use default\n");
 669         }
 670
 671         screen_fb_size = hdev->channel->offermsg.offer.
 672                                 mmio_megabytes * 1024 * 1024;
 673
 674         return 0;
 675
 676 error:
 677         vmbus_close(hdev->channel);
 678         return ret;
 679 }
 680
 681 /* Send VRAM and Situation messages to the host */
 682 static int synthvid_send_config(struct hv_device *hdev)
 683 {
 684         struct fb_info *info = hv_get_drvdata(hdev);
 685         struct hvfb_par *par = info->par;
 686         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
 687         int ret = 0;
 688         unsigned long t;
 689
 690         /* Send VRAM location */
 691         memset(msg, 0, sizeof(struct synthvid_msg));
 692         msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
 693         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 694                 sizeof(struct synthvid_vram_location);
 695         msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
 696         msg->vram.is_vram_gpa_specified = 1;
 697         synthvid_send(hdev, msg);
 698
 699         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
 700         if (!t) {
 701                 pr_err("Time out on waiting vram location ack\n");
 702                 ret = -ETIMEDOUT;
 703                 goto out;
 704         }
 705         if (msg->vram_ack.user_ctx != par->mmio_pp) {
 706                 pr_err("Unable to set VRAM location\n");
 707                 ret = -ENODEV;
 708                 goto out;
 709         }
 710
 711         /* Send pointer and situation update */
 712         synthvid_send_ptr(hdev);
 713         synthvid_send_situ(hdev);
 714
 715 out:
 716         return ret;
 717 }
 718
 719
 720 /*
 721  * Delayed work callback:
 722  * It is scheduled to call whenever update request is received and it has
 723  * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
 724  */
 725 static void hvfb_update_work(struct work_struct *w)
 726 {
 727         struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
 728         struct fb_info *info = par->info;
 729         unsigned long flags;
 730         int x1, x2, y1, y2;
 731         int j;
 732
 733         spin_lock_irqsave(&par->delayed_refresh_lock, flags);
 734         /* Reset the request flag */
 735         par->delayed_refresh = false;
 736
 737         /* Store the dirty rectangle to local variables */
 738         x1 = par->x1;
 739         x2 = par->x2;
 740         y1 = par->y1;
 741         y2 = par->y2;
 742
 743         /* Clear dirty rectangle */
 744         par->x1 = par->y1 = INT_MAX;
 745         par->x2 = par->y2 = 0;
 746
 747         spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
 748
 749         if (x1 > info->var.xres || x2 > info->var.xres ||
 750             y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
 751                 return;
 752
 753         /* Copy the dirty rectangle to frame buffer memory */
 754         for (j = y1; j < y2; j++) {
 755                 hvfb_docopy(par,
 756                             j * info->fix.line_length +
 757                             (x1 * screen_depth / 8),
 758                             (x2 - x1) * screen_depth / 8);
 759         }
 760
 761         /* Refresh */
 762         if (par->fb_ready && par->update)
 763                 synthvid_update(info, x1, y1, x2, y2);
 764 }
 765
 766 /*
 767  * Control the on-demand refresh frequency. It schedules a delayed
 768  * screen update if it has not yet.
 769  */
 770 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
 771                                            int x1, int y1, int w, int h)
 772 {
 773         unsigned long flags;
 774         int x2 = x1 + w;
 775         int y2 = y1 + h;
 776
 777         spin_lock_irqsave(&par->delayed_refresh_lock, flags);
 778
 779         /* Merge dirty rectangle */
 780         par->x1 = min_t(int, par->x1, x1);
 781         par->y1 = min_t(int, par->y1, y1);
 782         par->x2 = max_t(int, par->x2, x2);
 783         par->y2 = max_t(int, par->y2, y2);
 784
 785         /* Schedule a delayed screen update if not yet */
 786         if (par->delayed_refresh == false) {
 787                 schedule_delayed_work(&par->dwork,
 788                                       HVFB_ONDEMAND_THROTTLE);
 789                 par->delayed_refresh = true;
 790         }
 791
 792         spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
 793 }
 794
 795 static int hvfb_on_panic(struct notifier_block *nb,
 796                          unsigned long e, void *p)
 797 {
 798         struct hvfb_par *par;
 799         struct fb_info *info;
 800
 801         par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
 802         par->synchronous_fb = true;
 803         info = par->info;
 804         hvfb_docopy(par, 0, dio_fb_size);
 805         synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
 806
 807         return NOTIFY_DONE;
 808 }
 809
 810 /* Framebuffer operation handlers */
 811
 812 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 813 {
 814         if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
 815             var->xres > screen_width || var->yres >  screen_height ||
 816             var->bits_per_pixel != screen_depth)
 817                 return -EINVAL;
 818
 819         var->xres_virtual = var->xres;
 820         var->yres_virtual = var->yres;
 821
 822         return 0;
 823 }
 824
 825 static int hvfb_set_par(struct fb_info *info)
 826 {
 827         struct hv_device *hdev = device_to_hv_device(info->device);
 828
 829         return synthvid_send_situ(hdev);
 830 }
 831
 832
 833 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
 834 {
 835         return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
 836 }
 837
 838 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
 839                           unsigned blue, unsigned transp, struct fb_info *info)
 840 {
 841         u32 *pal = info->pseudo_palette;
 842
 843         if (regno > 15)
 844                 return -EINVAL;
 845
 846         pal[regno] = chan_to_field(red, &info->var.red)
 847                 | chan_to_field(green, &info->var.green)
 848                 | chan_to_field(blue, &info->var.blue)
 849                 | chan_to_field(transp, &info->var.transp);
 850
 851         return 0;
 852 }
 853
 854 static int hvfb_blank(int blank, struct fb_info *info)
 855 {
 856         return 1;       /* get fb_blank to set the colormap to all black */
 857 }
 858
 859 static void hvfb_cfb_fillrect(struct fb_info *p,
 860                               const struct fb_fillrect *rect)
 861 {
 862         struct hvfb_par *par = p->par;
 863
 864         cfb_fillrect(p, rect);
 865         if (par->synchronous_fb)
 866                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
 867         else
 868                 hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
 869                                                rect->width, rect->height);
 870 }
 871
 872 static void hvfb_cfb_copyarea(struct fb_info *p,
 873                               const struct fb_copyarea *area)
 874 {
 875         struct hvfb_par *par = p->par;
 876
 877         cfb_copyarea(p, area);
 878         if (par->synchronous_fb)
 879                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
 880         else
 881                 hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
 882                                                area->width, area->height);
 883 }
 884
 885 static void hvfb_cfb_imageblit(struct fb_info *p,
 886                                const struct fb_image *image)
 887 {
 888         struct hvfb_par *par = p->par;
 889
 890         cfb_imageblit(p, image);
 891         if (par->synchronous_fb)
 892                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
 893         else
 894                 hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
 895                                                image->width, image->height);
 896 }
 897
 898 static const struct fb_ops hvfb_ops = {
 899         .owner = THIS_MODULE,
 900         .fb_check_var = hvfb_check_var,
 901         .fb_set_par = hvfb_set_par,
 902         .fb_setcolreg = hvfb_setcolreg,
 903         .fb_fillrect = hvfb_cfb_fillrect,
 904         .fb_copyarea = hvfb_cfb_copyarea,
 905         .fb_imageblit = hvfb_cfb_imageblit,
 906         .fb_blank = hvfb_blank,
 907 };
 908
 909
 910 /* Get options from kernel paramenter "video=" */
 911 static void hvfb_get_option(struct fb_info *info)
 912 {
 913         struct hvfb_par *par = info->par;
 914         char *opt = NULL, *p;
 915         uint x = 0, y = 0;
 916
 917         if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
 918                 return;
 919
 920         p = strsep(&opt, "x");
 921         if (!*p || kstrtouint(p, 0, &x) ||
 922             !opt || !*opt || kstrtouint(opt, 0, &y)) {
 923                 pr_err("Screen option is invalid: skipped\n");
 924                 return;
 925         }
 926
 927         if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
 928             (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
 929             (x > screen_width_max || y > screen_height_max)) ||
 930             (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
 931              x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
 932             (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
 933              (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
 934                 pr_err("Screen resolution option is out of range: skipped\n");
 935                 return;
 936         }
 937
 938         screen_width = x;
 939         screen_height = y;
 940         return;
 941 }
 942
 943
 944 /* Get framebuffer memory from Hyper-V video pci space */
 945 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 946 {
 947         struct hvfb_par *par = info->par;
 948         struct pci_dev *pdev  = NULL;
 949         void __iomem *fb_virt;
 950         int gen2vm = efi_enabled(EFI_BOOT);
 951         resource_size_t pot_start, pot_end;
 952         int ret;
 953
 954         dio_fb_size =
 955                 screen_width * screen_height * screen_depth / 8;
 956
 957         if (gen2vm) {
 958                 pot_start = 0;
 959                 pot_end = -1;
 960         } else {
 961                 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
 962                               PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
 963                 if (!pdev) {
 964                         pr_err("Unable to find PCI Hyper-V video\n");
 965                         return -ENODEV;
 966                 }
 967
 968                 if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
 969                     pci_resource_len(pdev, 0) < screen_fb_size) {
 970                         pr_err("Resource not available or (0x%lx < 0x%lx)\n",
 971                                (unsigned long) pci_resource_len(pdev, 0),
 972                                (unsigned long) screen_fb_size);
 973                         goto err1;
 974                 }
 975
 976                 pot_end = pci_resource_end(pdev, 0);
 977                 pot_start = pot_end - screen_fb_size + 1;
 978         }
 979
 980         ret = vmbus_allocate_mmio(&par->mem, hdev, pot_start, pot_end,
 981                                   screen_fb_size, 0x100000, true);
 982         if (ret != 0) {
 983                 pr_err("Unable to allocate framebuffer memory\n");
 984                 goto err1;
 985         }
 986
 987         fb_virt = ioremap(par->mem->start, screen_fb_size);
 988         if (!fb_virt)
 989                 goto err2;
 990
 991         /* Allocate memory for deferred IO */
 992         par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
 993         if (par->dio_vp == NULL)
 994                 goto err3;
 995
 996         info->apertures = alloc_apertures(1);
 997         if (!info->apertures)
 998                 goto err4;
 999
1000         if (gen2vm) {
1001                 info->apertures->ranges[0].base = screen_info.lfb_base;
1002                 info->apertures->ranges[0].size = screen_info.lfb_size;
1003                 remove_conflicting_framebuffers(info->apertures,
1004                                                 KBUILD_MODNAME, false);
1005         } else {
1006                 info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1007                 info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1008         }
1009
1010         /* Physical address of FB device */
1011         par->mmio_pp = par->mem->start;
1012         /* Virtual address of FB device */
1013         par->mmio_vp = (unsigned char *) fb_virt;
1014
1015         info->fix.smem_start = par->mem->start;
1016         info->fix.smem_len = dio_fb_size;
1017         info->screen_base = par->dio_vp;
1018         info->screen_size = dio_fb_size;
1019
1020         if (!gen2vm)
1021                 pci_dev_put(pdev);
1022
1023         return 0;
1024
1025 err4:
1026         vfree(par->dio_vp);
1027 err3:
1028         iounmap(fb_virt);
1029 err2:
1030         vmbus_free_mmio(par->mem->start, screen_fb_size);
1031         par->mem = NULL;
1032 err1:
1033         if (!gen2vm)
1034                 pci_dev_put(pdev);
1035
1036         return -ENOMEM;
1037 }
1038
1039 /* Release the framebuffer */
1040 static void hvfb_putmem(struct fb_info *info)
1041 {
1042         struct hvfb_par *par = info->par;
1043
1044         vfree(par->dio_vp);
1045         iounmap(info->screen_base);
1046         vmbus_free_mmio(par->mem->start, screen_fb_size);
1047         par->mem = NULL;
1048 }
1049
1050
1051 static int hvfb_probe(struct hv_device *hdev,
1052                       const struct hv_vmbus_device_id *dev_id)
1053 {
1054         struct fb_info *info;
1055         struct hvfb_par *par;
1056         int ret;
1057
1058         info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1059         if (!info)
1060                 return -ENOMEM;
1061
1062         par = info->par;
1063         par->info = info;
1064         par->fb_ready = false;
1065         init_completion(&par->wait);
1066         INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1067
1068         par->delayed_refresh = false;
1069         spin_lock_init(&par->delayed_refresh_lock);
1070         par->x1 = par->y1 = INT_MAX;
1071         par->x2 = par->y2 = 0;
1072
1073         /* Connect to VSP */
1074         hv_set_drvdata(hdev, info);
1075         ret = synthvid_connect_vsp(hdev);
1076         if (ret) {
1077                 pr_err("Unable to connect to VSP\n");
1078                 goto error1;
1079         }
1080
1081         hvfb_get_option(info);
1082         pr_info("Screen resolution: %dx%d, Color depth: %d\n",
1083                 screen_width, screen_height, screen_depth);
1084
1085         ret = hvfb_getmem(hdev, info);
1086         if (ret) {
1087                 pr_err("No memory for framebuffer\n");
1088                 goto error2;
1089         }
1090
1091         /* Set up fb_info */
1092         info->flags = FBINFO_DEFAULT;
1093
1094         info->var.xres_virtual = info->var.xres = screen_width;
1095         info->var.yres_virtual = info->var.yres = screen_height;
1096         info->var.bits_per_pixel = screen_depth;
1097
1098         if (info->var.bits_per_pixel == 16) {
1099                 info->var.red = (struct fb_bitfield){11, 5, 0};
1100                 info->var.green = (struct fb_bitfield){5, 6, 0};
1101                 info->var.blue = (struct fb_bitfield){0, 5, 0};
1102                 info->var.transp = (struct fb_bitfield){0, 0, 0};
1103         } else {
1104                 info->var.red = (struct fb_bitfield){16, 8, 0};
1105                 info->var.green = (struct fb_bitfield){8, 8, 0};
1106                 info->var.blue = (struct fb_bitfield){0, 8, 0};
1107                 info->var.transp = (struct fb_bitfield){24, 8, 0};
1108         }
1109
1110         info->var.activate = FB_ACTIVATE_NOW;
1111         info->var.height = -1;
1112         info->var.width = -1;
1113         info->var.vmode = FB_VMODE_NONINTERLACED;
1114
1115         strcpy(info->fix.id, KBUILD_MODNAME);
1116         info->fix.type = FB_TYPE_PACKED_PIXELS;
1117         info->fix.visual = FB_VISUAL_TRUECOLOR;
1118         info->fix.line_length = screen_width * screen_depth / 8;
1119         info->fix.accel = FB_ACCEL_NONE;
1120
1121         info->fbops = &hvfb_ops;
1122         info->pseudo_palette = par->pseudo_palette;
1123
1124         /* Initialize deferred IO */
1125         info->fbdefio = &synthvid_defio;
1126         fb_deferred_io_init(info);
1127
1128         /* Send config to host */
1129         ret = synthvid_send_config(hdev);
1130         if (ret)
1131                 goto error;
1132
1133         ret = register_framebuffer(info);
1134         if (ret) {
1135                 pr_err("Unable to register framebuffer\n");
1136                 goto error;
1137         }
1138
1139         par->fb_ready = true;
1140
1141         par->synchronous_fb = false;
1142         par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1143         atomic_notifier_chain_register(&panic_notifier_list,
1144                                        &par->hvfb_panic_nb);
1145
1146         return 0;
1147
1148 error:
1149         fb_deferred_io_cleanup(info);
1150         hvfb_putmem(info);
1151 error2:
1152         vmbus_close(hdev->channel);
1153 error1:
1154         cancel_delayed_work_sync(&par->dwork);
1155         hv_set_drvdata(hdev, NULL);
1156         framebuffer_release(info);
1157         return ret;
1158 }
1159
1160
1161 static int hvfb_remove(struct hv_device *hdev)
1162 {
1163         struct fb_info *info = hv_get_drvdata(hdev);
1164         struct hvfb_par *par = info->par;
1165
1166         atomic_notifier_chain_unregister(&panic_notifier_list,
1167                                          &par->hvfb_panic_nb);
1168
1169         par->update = false;
1170         par->fb_ready = false;
1171
1172         fb_deferred_io_cleanup(info);
1173
1174         unregister_framebuffer(info);
1175         cancel_delayed_work_sync(&par->dwork);
1176
1177         vmbus_close(hdev->channel);
1178         hv_set_drvdata(hdev, NULL);
1179
1180         hvfb_putmem(info);
1181         framebuffer_release(info);
1182
1183         return 0;
1184 }
1185
1186 static int hvfb_suspend(struct hv_device *hdev)
1187 {
1188         struct fb_info *info = hv_get_drvdata(hdev);
1189         struct hvfb_par *par = info->par;
1190
1191         console_lock();
1192
1193         /* 1 means do suspend */
1194         fb_set_suspend(info, 1);
1195
1196         cancel_delayed_work_sync(&par->dwork);
1197
1198         par->update_saved = par->update;
1199         par->update = false;
1200         par->fb_ready = false;
1201
1202         vmbus_close(hdev->channel);
1203
1204         console_unlock();
1205
1206         return 0;
1207 }
1208
1209 static int hvfb_resume(struct hv_device *hdev)
1210 {
1211         struct fb_info *info = hv_get_drvdata(hdev);
1212         struct hvfb_par *par = info->par;
1213         int ret;
1214
1215         console_lock();
1216
1217         ret = synthvid_connect_vsp(hdev);
1218         if (ret != 0)
1219                 goto out;
1220
1221         ret = synthvid_send_config(hdev);
1222         if (ret != 0) {
1223                 vmbus_close(hdev->channel);
1224                 goto out;
1225         }
1226
1227         par->fb_ready = true;
1228         par->update = par->update_saved;
1229
1230         schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1231
1232         /* 0 means do resume */
1233         fb_set_suspend(info, 0);
1234
1235 out:
1236         console_unlock();
1237
1238         return ret;
1239 }
1240
1241
1242 static const struct pci_device_id pci_stub_id_table[] = {
1243         {
1244                 .vendor      = PCI_VENDOR_ID_MICROSOFT,
1245                 .device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1246         },
1247         { /* end of list */ }
1248 };
1249
1250 static const struct hv_vmbus_device_id id_table[] = {
1251         /* Synthetic Video Device GUID */
1252         {HV_SYNTHVID_GUID},
1253         {}
1254 };
1255
1256 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1257 MODULE_DEVICE_TABLE(vmbus, id_table);
1258
1259 static struct hv_driver hvfb_drv = {
1260         .name = KBUILD_MODNAME,
1261         .id_table = id_table,
1262         .probe = hvfb_probe,
1263         .remove = hvfb_remove,
1264         .suspend = hvfb_suspend,
1265         .resume = hvfb_resume,
1266         .driver = {
1267                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1268         },
1269 };
1270
1271 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1272                                const struct pci_device_id *ent)
1273 {
1274         return 0;
1275 }
1276
1277 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1278 {
1279 }
1280
1281 static struct pci_driver hvfb_pci_stub_driver = {
1282         .name =         KBUILD_MODNAME,
1283         .id_table =     pci_stub_id_table,
1284         .probe =        hvfb_pci_stub_probe,
1285         .remove =       hvfb_pci_stub_remove,
1286         .driver = {
1287                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1288         }
1289 };
1290
1291 static int __init hvfb_drv_init(void)
1292 {
1293         int ret;
1294
1295         ret = vmbus_driver_register(&hvfb_drv);
1296         if (ret != 0)
1297                 return ret;
1298
1299         ret = pci_register_driver(&hvfb_pci_stub_driver);
1300         if (ret != 0) {
1301                 vmbus_driver_unregister(&hvfb_drv);
1302                 return ret;
1303         }
1304
1305         return 0;
1306 }
1307
1308 static void __exit hvfb_drv_exit(void)
1309 {
1310         pci_unregister_driver(&hvfb_pci_stub_driver);
1311         vmbus_driver_unregister(&hvfb_drv);
1312 }
1313
1314 module_init(hvfb_drv_init);
1315 module_exit(hvfb_drv_exit);
1316
1317 MODULE_LICENSE("GPL");
1318 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");