drivers/hid/hid-hyperv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Copyright (c) 2009, Citrix Systems, Inc.
   4  *  Copyright (c) 2010, Microsoft Corporation.
   5  *  Copyright (c) 2011, Novell Inc.
   6  */
   7 #include <linux/init.h>
   8 #include <linux/module.h>
   9 #include <linux/device.h>
  10 #include <linux/completion.h>
  11 #include <linux/input.h>
  12 #include <linux/hid.h>
  13 #include <linux/hiddev.h>
  14 #include <linux/hyperv.h>
  15
  16
  17 struct hv_input_dev_info {
  18         unsigned int size;
  19         unsigned short vendor;
  20         unsigned short product;
  21         unsigned short version;
  22         unsigned short reserved[11];
  23 };
  24
  25 /* The maximum size of a synthetic input message. */
  26 #define SYNTHHID_MAX_INPUT_REPORT_SIZE 16
  27
  28 /*
  29  * Current version
  30  *
  31  * History:
  32  * Beta, RC < 2008/1/22        1,0
  33  * RC > 2008/1/22              2,0
  34  */
  35 #define SYNTHHID_INPUT_VERSION_MAJOR    2
  36 #define SYNTHHID_INPUT_VERSION_MINOR    0
  37 #define SYNTHHID_INPUT_VERSION          (SYNTHHID_INPUT_VERSION_MINOR | \
  38                                          (SYNTHHID_INPUT_VERSION_MAJOR << 16))
  39
  40
  41 #pragma pack(push, 1)
  42 /*
  43  * Message types in the synthetic input protocol
  44  */
  45 enum synthhid_msg_type {
  46         SYNTH_HID_PROTOCOL_REQUEST,
  47         SYNTH_HID_PROTOCOL_RESPONSE,
  48         SYNTH_HID_INITIAL_DEVICE_INFO,
  49         SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
  50         SYNTH_HID_INPUT_REPORT,
  51         SYNTH_HID_MAX
  52 };
  53
  54 /*
  55  * Basic message structures.
  56  */
  57 struct synthhid_msg_hdr {
  58         enum synthhid_msg_type type;
  59         u32 size;
  60 };
  61
  62 struct synthhid_msg {
  63         struct synthhid_msg_hdr header;
  64         char data[1]; /* Enclosed message */
  65 };
  66
  67 union synthhid_version {
  68         struct {
  69                 u16 minor_version;
  70                 u16 major_version;
  71         };
  72         u32 version;
  73 };
  74
  75 /*
  76  * Protocol messages
  77  */
  78 struct synthhid_protocol_request {
  79         struct synthhid_msg_hdr header;
  80         union synthhid_version version_requested;
  81 };
  82
  83 struct synthhid_protocol_response {
  84         struct synthhid_msg_hdr header;
  85         union synthhid_version version_requested;
  86         unsigned char approved;
  87 };
  88
  89 struct synthhid_device_info {
  90         struct synthhid_msg_hdr header;
  91         struct hv_input_dev_info hid_dev_info;
  92         struct hid_descriptor hid_descriptor;
  93 };
  94
  95 struct synthhid_device_info_ack {
  96         struct synthhid_msg_hdr header;
  97         unsigned char reserved;
  98 };
  99
 100 struct synthhid_input_report {
 101         struct synthhid_msg_hdr header;
 102         char buffer[1];
 103 };
 104
 105 #pragma pack(pop)
 106
 107 #define INPUTVSC_SEND_RING_BUFFER_SIZE          (40 * 1024)
 108 #define INPUTVSC_RECV_RING_BUFFER_SIZE          (40 * 1024)
 109
 110
 111 enum pipe_prot_msg_type {
 112         PIPE_MESSAGE_INVALID,
 113         PIPE_MESSAGE_DATA,
 114         PIPE_MESSAGE_MAXIMUM
 115 };
 116
 117
 118 struct pipe_prt_msg {
 119         enum pipe_prot_msg_type type;
 120         u32 size;
 121         char data[1];
 122 };
 123
 124 struct  mousevsc_prt_msg {
 125         enum pipe_prot_msg_type type;
 126         u32 size;
 127         union {
 128                 struct synthhid_protocol_request request;
 129                 struct synthhid_protocol_response response;
 130                 struct synthhid_device_info_ack ack;
 131         };
 132 };
 133
 134 /*
 135  * Represents an mousevsc device
 136  */
 137 struct mousevsc_dev {
 138         struct hv_device        *device;
 139         bool                    init_complete;
 140         bool                    connected;
 141         struct mousevsc_prt_msg protocol_req;
 142         struct mousevsc_prt_msg protocol_resp;
 143         /* Synchronize the request/response if needed */
 144         struct completion       wait_event;
 145         int                     dev_info_status;
 146
 147         struct hid_descriptor   *hid_desc;
 148         unsigned char           *report_desc;
 149         u32                     report_desc_size;
 150         struct hv_input_dev_info hid_dev_info;
 151         struct hid_device       *hid_device;
 152         u8                      input_buf[HID_MAX_BUFFER_SIZE];
 153 };
 154
 155
 156 static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
 157 {
 158         struct mousevsc_dev *input_dev;
 159
 160         input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
 161
 162         if (!input_dev)
 163                 return NULL;
 164
 165         input_dev->device = device;
 166         hv_set_drvdata(device, input_dev);
 167         init_completion(&input_dev->wait_event);
 168         input_dev->init_complete = false;
 169
 170         return input_dev;
 171 }
 172
 173 static void mousevsc_free_device(struct mousevsc_dev *device)
 174 {
 175         kfree(device->hid_desc);
 176         kfree(device->report_desc);
 177         hv_set_drvdata(device->device, NULL);
 178         kfree(device);
 179 }
 180
 181 static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
 182                                 struct synthhid_device_info *device_info)
 183 {
 184         int ret = 0;
 185         struct hid_descriptor *desc;
 186         struct mousevsc_prt_msg ack;
 187
 188         input_device->dev_info_status = -ENOMEM;
 189
 190         input_device->hid_dev_info = device_info->hid_dev_info;
 191         desc = &device_info->hid_descriptor;
 192         if (desc->bLength == 0)
 193                 goto cleanup;
 194
 195         /* The pointer is not NULL when we resume from hibernation */
 196         if (input_device->hid_desc != NULL)
 197                 kfree(input_device->hid_desc);
 198         input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
 199
 200         if (!input_device->hid_desc)
 201                 goto cleanup;
 202
 203         input_device->report_desc_size = desc->desc[0].wDescriptorLength;
 204         if (input_device->report_desc_size == 0) {
 205                 input_device->dev_info_status = -EINVAL;
 206                 goto cleanup;
 207         }
 208
 209         /* The pointer is not NULL when we resume from hibernation */
 210         if (input_device->report_desc != NULL)
 211                 kfree(input_device->report_desc);
 212         input_device->report_desc = kzalloc(input_device->report_desc_size,
 213                                           GFP_ATOMIC);
 214
 215         if (!input_device->report_desc) {
 216                 input_device->dev_info_status = -ENOMEM;
 217                 goto cleanup;
 218         }
 219
 220         memcpy(input_device->report_desc,
 221                ((unsigned char *)desc) + desc->bLength,
 222                desc->desc[0].wDescriptorLength);
 223
 224         /* Send the ack */
 225         memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
 226
 227         ack.type = PIPE_MESSAGE_DATA;
 228         ack.size = sizeof(struct synthhid_device_info_ack);
 229
 230         ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
 231         ack.ack.header.size = 1;
 232         ack.ack.reserved = 0;
 233
 234         ret = vmbus_sendpacket(input_device->device->channel,
 235                         &ack,
 236                         sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
 237                         sizeof(struct synthhid_device_info_ack),
 238                         (unsigned long)&ack,
 239                         VM_PKT_DATA_INBAND,
 240                         VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 241
 242         if (!ret)
 243                 input_device->dev_info_status = 0;
 244
 245 cleanup:
 246         complete(&input_device->wait_event);
 247
 248         return;
 249 }
 250
 251 static void mousevsc_on_receive(struct hv_device *device,
 252                                 struct vmpacket_descriptor *packet)
 253 {
 254         struct pipe_prt_msg *pipe_msg;
 255         struct synthhid_msg *hid_msg;
 256         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 257         struct synthhid_input_report *input_report;
 258         size_t len;
 259
 260         pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
 261                                                 (packet->offset8 << 3));
 262
 263         if (pipe_msg->type != PIPE_MESSAGE_DATA)
 264                 return;
 265
 266         hid_msg = (struct synthhid_msg *)pipe_msg->data;
 267
 268         switch (hid_msg->header.type) {
 269         case SYNTH_HID_PROTOCOL_RESPONSE:
 270                 /*
 271                  * While it will be impossible for us to protect against
 272                  * malicious/buggy hypervisor/host, add a check here to
 273                  * ensure we don't corrupt memory.
 274                  */
 275                 if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
 276                         - sizeof(unsigned char))
 277                         > sizeof(struct mousevsc_prt_msg)) {
 278                         WARN_ON(1);
 279                         break;
 280                 }
 281
 282                 memcpy(&input_dev->protocol_resp, pipe_msg,
 283                        pipe_msg->size + sizeof(struct pipe_prt_msg) -
 284                        sizeof(unsigned char));
 285                 complete(&input_dev->wait_event);
 286                 break;
 287
 288         case SYNTH_HID_INITIAL_DEVICE_INFO:
 289                 WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
 290
 291                 /*
 292                  * Parse out the device info into device attr,
 293                  * hid desc and report desc
 294                  */
 295                 mousevsc_on_receive_device_info(input_dev,
 296                         (struct synthhid_device_info *)pipe_msg->data);
 297                 break;
 298         case SYNTH_HID_INPUT_REPORT:
 299                 input_report =
 300                         (struct synthhid_input_report *)pipe_msg->data;
 301                 if (!input_dev->init_complete)
 302                         break;
 303
 304                 len = min(input_report->header.size,
 305                           (u32)sizeof(input_dev->input_buf));
 306                 memcpy(input_dev->input_buf, input_report->buffer, len);
 307                 hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
 308                                  input_dev->input_buf, len, 1);
 309
 310                 pm_wakeup_hard_event(&input_dev->device->device);
 311
 312                 break;
 313         default:
 314                 pr_err("unsupported hid msg type - type %d len %d\n",
 315                        hid_msg->header.type, hid_msg->header.size);
 316                 break;
 317         }
 318
 319 }
 320
 321 static void mousevsc_on_channel_callback(void *context)
 322 {
 323         struct hv_device *device = context;
 324         struct vmpacket_descriptor *desc;
 325
 326         foreach_vmbus_pkt(desc, device->channel) {
 327                 switch (desc->type) {
 328                 case VM_PKT_COMP:
 329                         break;
 330
 331                 case VM_PKT_DATA_INBAND:
 332                         mousevsc_on_receive(device, desc);
 333                         break;
 334
 335                 default:
 336                         pr_err("Unhandled packet type %d, tid %llx len %d\n",
 337                                desc->type, desc->trans_id, desc->len8 * 8);
 338                         break;
 339                 }
 340         }
 341 }
 342
 343 static int mousevsc_connect_to_vsp(struct hv_device *device)
 344 {
 345         int ret = 0;
 346         unsigned long t;
 347         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 348         struct mousevsc_prt_msg *request;
 349         struct mousevsc_prt_msg *response;
 350
 351         reinit_completion(&input_dev->wait_event);
 352
 353         request = &input_dev->protocol_req;
 354         memset(request, 0, sizeof(struct mousevsc_prt_msg));
 355
 356         request->type = PIPE_MESSAGE_DATA;
 357         request->size = sizeof(struct synthhid_protocol_request);
 358         request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
 359         request->request.header.size = sizeof(unsigned int);
 360         request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
 361
 362         ret = vmbus_sendpacket(device->channel, request,
 363                                 sizeof(struct pipe_prt_msg) -
 364                                 sizeof(unsigned char) +
 365                                 sizeof(struct synthhid_protocol_request),
 366                                 (unsigned long)request,
 367                                 VM_PKT_DATA_INBAND,
 368                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 369         if (ret)
 370                 goto cleanup;
 371
 372         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 373         if (!t) {
 374                 ret = -ETIMEDOUT;
 375                 goto cleanup;
 376         }
 377
 378         response = &input_dev->protocol_resp;
 379
 380         if (!response->response.approved) {
 381                 pr_err("synthhid protocol request failed (version %d)\n",
 382                        SYNTHHID_INPUT_VERSION);
 383                 ret = -ENODEV;
 384                 goto cleanup;
 385         }
 386
 387         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 388         if (!t) {
 389                 ret = -ETIMEDOUT;
 390                 goto cleanup;
 391         }
 392
 393         /*
 394          * We should have gotten the device attr, hid desc and report
 395          * desc at this point
 396          */
 397         ret = input_dev->dev_info_status;
 398
 399 cleanup:
 400         return ret;
 401 }
 402
 403 static int mousevsc_hid_parse(struct hid_device *hid)
 404 {
 405         struct hv_device *dev = hid_get_drvdata(hid);
 406         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 407
 408         return hid_parse_report(hid, input_dev->report_desc,
 409                                 input_dev->report_desc_size);
 410 }
 411
 412 static int mousevsc_hid_open(struct hid_device *hid)
 413 {
 414         return 0;
 415 }
 416
 417 static int mousevsc_hid_start(struct hid_device *hid)
 418 {
 419         return 0;
 420 }
 421
 422 static void mousevsc_hid_close(struct hid_device *hid)
 423 {
 424 }
 425
 426 static void mousevsc_hid_stop(struct hid_device *hid)
 427 {
 428 }
 429
 430 static int mousevsc_hid_raw_request(struct hid_device *hid,
 431                                     unsigned char report_num,
 432                                     __u8 *buf, size_t len,
 433                                     unsigned char rtype,
 434                                     int reqtype)
 435 {
 436         return 0;
 437 }
 438
 439 static struct hid_ll_driver mousevsc_ll_driver = {
 440         .parse = mousevsc_hid_parse,
 441         .open = mousevsc_hid_open,
 442         .close = mousevsc_hid_close,
 443         .start = mousevsc_hid_start,
 444         .stop = mousevsc_hid_stop,
 445         .raw_request = mousevsc_hid_raw_request,
 446 };
 447
 448 static struct hid_driver mousevsc_hid_driver;
 449
 450 static int mousevsc_probe(struct hv_device *device,
 451                         const struct hv_vmbus_device_id *dev_id)
 452 {
 453         int ret;
 454         struct mousevsc_dev *input_dev;
 455         struct hid_device *hid_dev;
 456
 457         input_dev = mousevsc_alloc_device(device);
 458
 459         if (!input_dev)
 460                 return -ENOMEM;
 461
 462         ret = vmbus_open(device->channel,
 463                 INPUTVSC_SEND_RING_BUFFER_SIZE,
 464                 INPUTVSC_RECV_RING_BUFFER_SIZE,
 465                 NULL,
 466                 0,
 467                 mousevsc_on_channel_callback,
 468                 device
 469                 );
 470
 471         if (ret)
 472                 goto probe_err0;
 473
 474         ret = mousevsc_connect_to_vsp(device);
 475
 476         if (ret)
 477                 goto probe_err1;
 478
 479         /* workaround SA-167 */
 480         if (input_dev->report_desc[14] == 0x25)
 481                 input_dev->report_desc[14] = 0x29;
 482
 483         hid_dev = hid_allocate_device();
 484         if (IS_ERR(hid_dev)) {
 485                 ret = PTR_ERR(hid_dev);
 486                 goto probe_err1;
 487         }
 488
 489         hid_dev->ll_driver = &mousevsc_ll_driver;
 490         hid_dev->driver = &mousevsc_hid_driver;
 491         hid_dev->bus = BUS_VIRTUAL;
 492         hid_dev->vendor = input_dev->hid_dev_info.vendor;
 493         hid_dev->product = input_dev->hid_dev_info.product;
 494         hid_dev->version = input_dev->hid_dev_info.version;
 495         input_dev->hid_device = hid_dev;
 496
 497         sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
 498
 499         hid_set_drvdata(hid_dev, device);
 500
 501         ret = hid_add_device(hid_dev);
 502         if (ret)
 503                 goto probe_err1;
 504
 505
 506         ret = hid_parse(hid_dev);
 507         if (ret) {
 508                 hid_err(hid_dev, "parse failed\n");
 509                 goto probe_err2;
 510         }
 511
 512         ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
 513
 514         if (ret) {
 515                 hid_err(hid_dev, "hw start failed\n");
 516                 goto probe_err2;
 517         }
 518
 519         device_init_wakeup(&device->device, true);
 520
 521         input_dev->connected = true;
 522         input_dev->init_complete = true;
 523
 524         return ret;
 525
 526 probe_err2:
 527         hid_destroy_device(hid_dev);
 528
 529 probe_err1:
 530         vmbus_close(device->channel);
 531
 532 probe_err0:
 533         mousevsc_free_device(input_dev);
 534
 535         return ret;
 536 }
 537
 538
 539 static int mousevsc_remove(struct hv_device *dev)
 540 {
 541         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 542
 543         device_init_wakeup(&dev->device, false);
 544         vmbus_close(dev->channel);
 545         hid_hw_stop(input_dev->hid_device);
 546         hid_destroy_device(input_dev->hid_device);
 547         mousevsc_free_device(input_dev);
 548
 549         return 0;
 550 }
 551
 552 static int mousevsc_suspend(struct hv_device *dev)
 553 {
 554         vmbus_close(dev->channel);
 555
 556         return 0;
 557 }
 558
 559 static int mousevsc_resume(struct hv_device *dev)
 560 {
 561         int ret;
 562
 563         ret = vmbus_open(dev->channel,
 564                          INPUTVSC_SEND_RING_BUFFER_SIZE,
 565                          INPUTVSC_RECV_RING_BUFFER_SIZE,
 566                          NULL, 0,
 567                          mousevsc_on_channel_callback,
 568                          dev);
 569         if (ret)
 570                 return ret;
 571
 572         ret = mousevsc_connect_to_vsp(dev);
 573         return ret;
 574 }
 575
 576 static const struct hv_vmbus_device_id id_table[] = {
 577         /* Mouse guid */
 578         { HV_MOUSE_GUID, },
 579         { },
 580 };
 581
 582 MODULE_DEVICE_TABLE(vmbus, id_table);
 583
 584 static struct  hv_driver mousevsc_drv = {
 585         .name = KBUILD_MODNAME,
 586         .id_table = id_table,
 587         .probe = mousevsc_probe,
 588         .remove = mousevsc_remove,
 589         .suspend = mousevsc_suspend,
 590         .resume = mousevsc_resume,
 591         .driver = {
 592                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 593         },
 594 };
 595
 596 static int __init mousevsc_init(void)
 597 {
 598         return vmbus_driver_register(&mousevsc_drv);
 599 }
 600
 601 static void __exit mousevsc_exit(void)
 602 {
 603         vmbus_driver_unregister(&mousevsc_drv);
 604 }
 605
 606 MODULE_LICENSE("GPL");
 607 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
 608
 609 module_init(mousevsc_init);
 610 module_exit(mousevsc_exit);