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          (10*PAGE_SIZE)
 108 #define INPUTVSC_RECV_RING_BUFFER_SIZE          (10*PAGE_SIZE)
 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         input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
 196
 197         if (!input_device->hid_desc)
 198                 goto cleanup;
 199
 200         input_device->report_desc_size = desc->desc[0].wDescriptorLength;
 201         if (input_device->report_desc_size == 0) {
 202                 input_device->dev_info_status = -EINVAL;
 203                 goto cleanup;
 204         }
 205
 206         input_device->report_desc = kzalloc(input_device->report_desc_size,
 207                                           GFP_ATOMIC);
 208
 209         if (!input_device->report_desc) {
 210                 input_device->dev_info_status = -ENOMEM;
 211                 goto cleanup;
 212         }
 213
 214         memcpy(input_device->report_desc,
 215                ((unsigned char *)desc) + desc->bLength,
 216                desc->desc[0].wDescriptorLength);
 217
 218         /* Send the ack */
 219         memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
 220
 221         ack.type = PIPE_MESSAGE_DATA;
 222         ack.size = sizeof(struct synthhid_device_info_ack);
 223
 224         ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
 225         ack.ack.header.size = 1;
 226         ack.ack.reserved = 0;
 227
 228         ret = vmbus_sendpacket(input_device->device->channel,
 229                         &ack,
 230                         sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
 231                         sizeof(struct synthhid_device_info_ack),
 232                         (unsigned long)&ack,
 233                         VM_PKT_DATA_INBAND,
 234                         VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 235
 236         if (!ret)
 237                 input_device->dev_info_status = 0;
 238
 239 cleanup:
 240         complete(&input_device->wait_event);
 241
 242         return;
 243 }
 244
 245 static void mousevsc_on_receive(struct hv_device *device,
 246                                 struct vmpacket_descriptor *packet)
 247 {
 248         struct pipe_prt_msg *pipe_msg;
 249         struct synthhid_msg *hid_msg;
 250         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 251         struct synthhid_input_report *input_report;
 252         size_t len;
 253
 254         pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
 255                                                 (packet->offset8 << 3));
 256
 257         if (pipe_msg->type != PIPE_MESSAGE_DATA)
 258                 return;
 259
 260         hid_msg = (struct synthhid_msg *)pipe_msg->data;
 261
 262         switch (hid_msg->header.type) {
 263         case SYNTH_HID_PROTOCOL_RESPONSE:
 264                 /*
 265                  * While it will be impossible for us to protect against
 266                  * malicious/buggy hypervisor/host, add a check here to
 267                  * ensure we don't corrupt memory.
 268                  */
 269                 if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
 270                         - sizeof(unsigned char))
 271                         > sizeof(struct mousevsc_prt_msg)) {
 272                         WARN_ON(1);
 273                         break;
 274                 }
 275
 276                 memcpy(&input_dev->protocol_resp, pipe_msg,
 277                        pipe_msg->size + sizeof(struct pipe_prt_msg) -
 278                        sizeof(unsigned char));
 279                 complete(&input_dev->wait_event);
 280                 break;
 281
 282         case SYNTH_HID_INITIAL_DEVICE_INFO:
 283                 WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
 284
 285                 /*
 286                  * Parse out the device info into device attr,
 287                  * hid desc and report desc
 288                  */
 289                 mousevsc_on_receive_device_info(input_dev,
 290                         (struct synthhid_device_info *)pipe_msg->data);
 291                 break;
 292         case SYNTH_HID_INPUT_REPORT:
 293                 input_report =
 294                         (struct synthhid_input_report *)pipe_msg->data;
 295                 if (!input_dev->init_complete)
 296                         break;
 297
 298                 len = min(input_report->header.size,
 299                           (u32)sizeof(input_dev->input_buf));
 300                 memcpy(input_dev->input_buf, input_report->buffer, len);
 301                 hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
 302                                  input_dev->input_buf, len, 1);
 303
 304                 pm_wakeup_hard_event(&input_dev->device->device);
 305
 306                 break;
 307         default:
 308                 pr_err("unsupported hid msg type - type %d len %d\n",
 309                        hid_msg->header.type, hid_msg->header.size);
 310                 break;
 311         }
 312
 313 }
 314
 315 static void mousevsc_on_channel_callback(void *context)
 316 {
 317         const int packet_size = 0x100;
 318         int ret;
 319         struct hv_device *device = context;
 320         u32 bytes_recvd;
 321         u64 req_id;
 322         struct vmpacket_descriptor *desc;
 323         unsigned char   *buffer;
 324         int     bufferlen = packet_size;
 325
 326         buffer = kmalloc(bufferlen, GFP_ATOMIC);
 327         if (!buffer)
 328                 return;
 329
 330         do {
 331                 ret = vmbus_recvpacket_raw(device->channel, buffer,
 332                                         bufferlen, &bytes_recvd, &req_id);
 333
 334                 switch (ret) {
 335                 case 0:
 336                         if (bytes_recvd <= 0) {
 337                                 kfree(buffer);
 338                                 return;
 339                         }
 340                         desc = (struct vmpacket_descriptor *)buffer;
 341
 342                         switch (desc->type) {
 343                         case VM_PKT_COMP:
 344                                 break;
 345
 346                         case VM_PKT_DATA_INBAND:
 347                                 mousevsc_on_receive(device, desc);
 348                                 break;
 349
 350                         default:
 351                                 pr_err("unhandled packet type %d, tid %llx len %d\n",
 352                                         desc->type, req_id, bytes_recvd);
 353                                 break;
 354                         }
 355
 356                         break;
 357
 358                 case -ENOBUFS:
 359                         kfree(buffer);
 360                         /* Handle large packet */
 361                         bufferlen = bytes_recvd;
 362                         buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 363
 364                         if (!buffer)
 365                                 return;
 366
 367                         break;
 368                 }
 369         } while (1);
 370
 371 }
 372
 373 static int mousevsc_connect_to_vsp(struct hv_device *device)
 374 {
 375         int ret = 0;
 376         unsigned long t;
 377         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 378         struct mousevsc_prt_msg *request;
 379         struct mousevsc_prt_msg *response;
 380
 381         request = &input_dev->protocol_req;
 382         memset(request, 0, sizeof(struct mousevsc_prt_msg));
 383
 384         request->type = PIPE_MESSAGE_DATA;
 385         request->size = sizeof(struct synthhid_protocol_request);
 386         request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
 387         request->request.header.size = sizeof(unsigned int);
 388         request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
 389
 390         ret = vmbus_sendpacket(device->channel, request,
 391                                 sizeof(struct pipe_prt_msg) -
 392                                 sizeof(unsigned char) +
 393                                 sizeof(struct synthhid_protocol_request),
 394                                 (unsigned long)request,
 395                                 VM_PKT_DATA_INBAND,
 396                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 397         if (ret)
 398                 goto cleanup;
 399
 400         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 401         if (!t) {
 402                 ret = -ETIMEDOUT;
 403                 goto cleanup;
 404         }
 405
 406         response = &input_dev->protocol_resp;
 407
 408         if (!response->response.approved) {
 409                 pr_err("synthhid protocol request failed (version %d)\n",
 410                        SYNTHHID_INPUT_VERSION);
 411                 ret = -ENODEV;
 412                 goto cleanup;
 413         }
 414
 415         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 416         if (!t) {
 417                 ret = -ETIMEDOUT;
 418                 goto cleanup;
 419         }
 420
 421         /*
 422          * We should have gotten the device attr, hid desc and report
 423          * desc at this point
 424          */
 425         ret = input_dev->dev_info_status;
 426
 427 cleanup:
 428         return ret;
 429 }
 430
 431 static int mousevsc_hid_parse(struct hid_device *hid)
 432 {
 433         struct hv_device *dev = hid_get_drvdata(hid);
 434         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 435
 436         return hid_parse_report(hid, input_dev->report_desc,
 437                                 input_dev->report_desc_size);
 438 }
 439
 440 static int mousevsc_hid_open(struct hid_device *hid)
 441 {
 442         return 0;
 443 }
 444
 445 static int mousevsc_hid_start(struct hid_device *hid)
 446 {
 447         return 0;
 448 }
 449
 450 static void mousevsc_hid_close(struct hid_device *hid)
 451 {
 452 }
 453
 454 static void mousevsc_hid_stop(struct hid_device *hid)
 455 {
 456 }
 457
 458 static int mousevsc_hid_raw_request(struct hid_device *hid,
 459                                     unsigned char report_num,
 460                                     __u8 *buf, size_t len,
 461                                     unsigned char rtype,
 462                                     int reqtype)
 463 {
 464         return 0;
 465 }
 466
 467 static struct hid_ll_driver mousevsc_ll_driver = {
 468         .parse = mousevsc_hid_parse,
 469         .open = mousevsc_hid_open,
 470         .close = mousevsc_hid_close,
 471         .start = mousevsc_hid_start,
 472         .stop = mousevsc_hid_stop,
 473         .raw_request = mousevsc_hid_raw_request,
 474 };
 475
 476 static struct hid_driver mousevsc_hid_driver;
 477
 478 static int mousevsc_probe(struct hv_device *device,
 479                         const struct hv_vmbus_device_id *dev_id)
 480 {
 481         int ret;
 482         struct mousevsc_dev *input_dev;
 483         struct hid_device *hid_dev;
 484
 485         input_dev = mousevsc_alloc_device(device);
 486
 487         if (!input_dev)
 488                 return -ENOMEM;
 489
 490         ret = vmbus_open(device->channel,
 491                 INPUTVSC_SEND_RING_BUFFER_SIZE,
 492                 INPUTVSC_RECV_RING_BUFFER_SIZE,
 493                 NULL,
 494                 0,
 495                 mousevsc_on_channel_callback,
 496                 device
 497                 );
 498
 499         if (ret)
 500                 goto probe_err0;
 501
 502         ret = mousevsc_connect_to_vsp(device);
 503
 504         if (ret)
 505                 goto probe_err1;
 506
 507         /* workaround SA-167 */
 508         if (input_dev->report_desc[14] == 0x25)
 509                 input_dev->report_desc[14] = 0x29;
 510
 511         hid_dev = hid_allocate_device();
 512         if (IS_ERR(hid_dev)) {
 513                 ret = PTR_ERR(hid_dev);
 514                 goto probe_err1;
 515         }
 516
 517         hid_dev->ll_driver = &mousevsc_ll_driver;
 518         hid_dev->driver = &mousevsc_hid_driver;
 519         hid_dev->bus = BUS_VIRTUAL;
 520         hid_dev->vendor = input_dev->hid_dev_info.vendor;
 521         hid_dev->product = input_dev->hid_dev_info.product;
 522         hid_dev->version = input_dev->hid_dev_info.version;
 523         input_dev->hid_device = hid_dev;
 524
 525         sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
 526
 527         hid_set_drvdata(hid_dev, device);
 528
 529         ret = hid_add_device(hid_dev);
 530         if (ret)
 531                 goto probe_err1;
 532
 533
 534         ret = hid_parse(hid_dev);
 535         if (ret) {
 536                 hid_err(hid_dev, "parse failed\n");
 537                 goto probe_err2;
 538         }
 539
 540         ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
 541
 542         if (ret) {
 543                 hid_err(hid_dev, "hw start failed\n");
 544                 goto probe_err2;
 545         }
 546
 547         device_init_wakeup(&device->device, true);
 548
 549         input_dev->connected = true;
 550         input_dev->init_complete = true;
 551
 552         return ret;
 553
 554 probe_err2:
 555         hid_destroy_device(hid_dev);
 556
 557 probe_err1:
 558         vmbus_close(device->channel);
 559
 560 probe_err0:
 561         mousevsc_free_device(input_dev);
 562
 563         return ret;
 564 }
 565
 566
 567 static int mousevsc_remove(struct hv_device *dev)
 568 {
 569         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 570
 571         device_init_wakeup(&dev->device, false);
 572         vmbus_close(dev->channel);
 573         hid_hw_stop(input_dev->hid_device);
 574         hid_destroy_device(input_dev->hid_device);
 575         mousevsc_free_device(input_dev);
 576
 577         return 0;
 578 }
 579
 580 static const struct hv_vmbus_device_id id_table[] = {
 581         /* Mouse guid */
 582         { HV_MOUSE_GUID, },
 583         { },
 584 };
 585
 586 MODULE_DEVICE_TABLE(vmbus, id_table);
 587
 588 static struct  hv_driver mousevsc_drv = {
 589         .name = KBUILD_MODNAME,
 590         .id_table = id_table,
 591         .probe = mousevsc_probe,
 592         .remove = mousevsc_remove,
 593         .driver = {
 594                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 595         },
 596 };
 597
 598 static int __init mousevsc_init(void)
 599 {
 600         return vmbus_driver_register(&mousevsc_drv);
 601 }
 602
 603 static void __exit mousevsc_exit(void)
 604 {
 605         vmbus_driver_unregister(&mousevsc_drv);
 606 }
 607
 608 MODULE_LICENSE("GPL");
 609 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
 610
 611 module_init(mousevsc_init);
 612 module_exit(mousevsc_exit);