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  VMBUS_RING_SIZE(36 * 1024)
 108 #define INPUTVSC_RECV_RING_BUFFER_SIZE  VMBUS_RING_SIZE(36 * 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         kfree(input_device->hid_desc);
 197         input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
 198
 199         if (!input_device->hid_desc)
 200                 goto cleanup;
 201
 202         input_device->report_desc_size = le16_to_cpu(
 203                                         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         kfree(input_device->report_desc);
 211         input_device->report_desc = kzalloc(input_device->report_desc_size,
 212                                           GFP_ATOMIC);
 213
 214         if (!input_device->report_desc) {
 215                 input_device->dev_info_status = -ENOMEM;
 216                 goto cleanup;
 217         }
 218
 219         memcpy(input_device->report_desc,
 220                ((unsigned char *)desc) + desc->bLength,
 221                le16_to_cpu(desc->desc[0].wDescriptorLength));
 222
 223         /* Send the ack */
 224         memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
 225
 226         ack.type = PIPE_MESSAGE_DATA;
 227         ack.size = sizeof(struct synthhid_device_info_ack);
 228
 229         ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
 230         ack.ack.header.size = 1;
 231         ack.ack.reserved = 0;
 232
 233         ret = vmbus_sendpacket(input_device->device->channel,
 234                         &ack,
 235                         sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
 236                         sizeof(struct synthhid_device_info_ack),
 237                         (unsigned long)&ack,
 238                         VM_PKT_DATA_INBAND,
 239                         VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 240
 241         if (!ret)
 242                 input_device->dev_info_status = 0;
 243
 244 cleanup:
 245         complete(&input_device->wait_event);
 246
 247         return;
 248 }
 249
 250 static void mousevsc_on_receive(struct hv_device *device,
 251                                 struct vmpacket_descriptor *packet)
 252 {
 253         struct pipe_prt_msg *pipe_msg;
 254         struct synthhid_msg *hid_msg;
 255         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 256         struct synthhid_input_report *input_report;
 257         size_t len;
 258
 259         pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
 260                                                 (packet->offset8 << 3));
 261
 262         if (pipe_msg->type != PIPE_MESSAGE_DATA)
 263                 return;
 264
 265         hid_msg = (struct synthhid_msg *)pipe_msg->data;
 266
 267         switch (hid_msg->header.type) {
 268         case SYNTH_HID_PROTOCOL_RESPONSE:
 269                 /*
 270                  * While it will be impossible for us to protect against
 271                  * malicious/buggy hypervisor/host, add a check here to
 272                  * ensure we don't corrupt memory.
 273                  */
 274                 if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
 275                         - sizeof(unsigned char))
 276                         > sizeof(struct mousevsc_prt_msg)) {
 277                         WARN_ON(1);
 278                         break;
 279                 }
 280
 281                 memcpy(&input_dev->protocol_resp, pipe_msg,
 282                        pipe_msg->size + sizeof(struct pipe_prt_msg) -
 283                        sizeof(unsigned char));
 284                 complete(&input_dev->wait_event);
 285                 break;
 286
 287         case SYNTH_HID_INITIAL_DEVICE_INFO:
 288                 WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
 289
 290                 /*
 291                  * Parse out the device info into device attr,
 292                  * hid desc and report desc
 293                  */
 294                 mousevsc_on_receive_device_info(input_dev,
 295                         (struct synthhid_device_info *)pipe_msg->data);
 296                 break;
 297         case SYNTH_HID_INPUT_REPORT:
 298                 input_report =
 299                         (struct synthhid_input_report *)pipe_msg->data;
 300                 if (!input_dev->init_complete)
 301                         break;
 302
 303                 len = min(input_report->header.size,
 304                           (u32)sizeof(input_dev->input_buf));
 305                 memcpy(input_dev->input_buf, input_report->buffer, len);
 306                 hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
 307                                  input_dev->input_buf, len, 1);
 308
 309                 pm_wakeup_hard_event(&input_dev->device->device);
 310
 311                 break;
 312         default:
 313                 pr_err("unsupported hid msg type - type %d len %d\n",
 314                        hid_msg->header.type, hid_msg->header.size);
 315                 break;
 316         }
 317
 318 }
 319
 320 static void mousevsc_on_channel_callback(void *context)
 321 {
 322         struct hv_device *device = context;
 323         struct vmpacket_descriptor *desc;
 324
 325         foreach_vmbus_pkt(desc, device->channel) {
 326                 switch (desc->type) {
 327                 case VM_PKT_COMP:
 328                         break;
 329
 330                 case VM_PKT_DATA_INBAND:
 331                         mousevsc_on_receive(device, desc);
 332                         break;
 333
 334                 default:
 335                         pr_err("Unhandled packet type %d, tid %llx len %d\n",
 336                                desc->type, desc->trans_id, desc->len8 * 8);
 337                         break;
 338                 }
 339         }
 340 }
 341
 342 static int mousevsc_connect_to_vsp(struct hv_device *device)
 343 {
 344         int ret = 0;
 345         unsigned long t;
 346         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 347         struct mousevsc_prt_msg *request;
 348         struct mousevsc_prt_msg *response;
 349
 350         reinit_completion(&input_dev->wait_event);
 351
 352         request = &input_dev->protocol_req;
 353         memset(request, 0, sizeof(struct mousevsc_prt_msg));
 354
 355         request->type = PIPE_MESSAGE_DATA;
 356         request->size = sizeof(struct synthhid_protocol_request);
 357         request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
 358         request->request.header.size = sizeof(unsigned int);
 359         request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
 360
 361         ret = vmbus_sendpacket(device->channel, request,
 362                                 sizeof(struct pipe_prt_msg) -
 363                                 sizeof(unsigned char) +
 364                                 sizeof(struct synthhid_protocol_request),
 365                                 (unsigned long)request,
 366                                 VM_PKT_DATA_INBAND,
 367                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 368         if (ret)
 369                 goto cleanup;
 370
 371         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 372         if (!t) {
 373                 ret = -ETIMEDOUT;
 374                 goto cleanup;
 375         }
 376
 377         response = &input_dev->protocol_resp;
 378
 379         if (!response->response.approved) {
 380                 pr_err("synthhid protocol request failed (version %d)\n",
 381                        SYNTHHID_INPUT_VERSION);
 382                 ret = -ENODEV;
 383                 goto cleanup;
 384         }
 385
 386         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 387         if (!t) {
 388                 ret = -ETIMEDOUT;
 389                 goto cleanup;
 390         }
 391
 392         /*
 393          * We should have gotten the device attr, hid desc and report
 394          * desc at this point
 395          */
 396         ret = input_dev->dev_info_status;
 397
 398 cleanup:
 399         return ret;
 400 }
 401
 402 static int mousevsc_hid_parse(struct hid_device *hid)
 403 {
 404         struct hv_device *dev = hid_get_drvdata(hid);
 405         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 406
 407         return hid_parse_report(hid, input_dev->report_desc,
 408                                 input_dev->report_desc_size);
 409 }
 410
 411 static int mousevsc_hid_open(struct hid_device *hid)
 412 {
 413         return 0;
 414 }
 415
 416 static int mousevsc_hid_start(struct hid_device *hid)
 417 {
 418         return 0;
 419 }
 420
 421 static void mousevsc_hid_close(struct hid_device *hid)
 422 {
 423 }
 424
 425 static void mousevsc_hid_stop(struct hid_device *hid)
 426 {
 427 }
 428
 429 static int mousevsc_hid_raw_request(struct hid_device *hid,
 430                                     unsigned char report_num,
 431                                     __u8 *buf, size_t len,
 432                                     unsigned char rtype,
 433                                     int reqtype)
 434 {
 435         return 0;
 436 }
 437
 438 static struct hid_ll_driver mousevsc_ll_driver = {
 439         .parse = mousevsc_hid_parse,
 440         .open = mousevsc_hid_open,
 441         .close = mousevsc_hid_close,
 442         .start = mousevsc_hid_start,
 443         .stop = mousevsc_hid_stop,
 444         .raw_request = mousevsc_hid_raw_request,
 445 };
 446
 447 static struct hid_driver mousevsc_hid_driver;
 448
 449 static int mousevsc_probe(struct hv_device *device,
 450                         const struct hv_vmbus_device_id *dev_id)
 451 {
 452         int ret;
 453         struct mousevsc_dev *input_dev;
 454         struct hid_device *hid_dev;
 455
 456         input_dev = mousevsc_alloc_device(device);
 457
 458         if (!input_dev)
 459                 return -ENOMEM;
 460
 461         ret = vmbus_open(device->channel,
 462                 INPUTVSC_SEND_RING_BUFFER_SIZE,
 463                 INPUTVSC_RECV_RING_BUFFER_SIZE,
 464                 NULL,
 465                 0,
 466                 mousevsc_on_channel_callback,
 467                 device
 468                 );
 469
 470         if (ret)
 471                 goto probe_err0;
 472
 473         ret = mousevsc_connect_to_vsp(device);
 474
 475         if (ret)
 476                 goto probe_err1;
 477
 478         /* workaround SA-167 */
 479         if (input_dev->report_desc[14] == 0x25)
 480                 input_dev->report_desc[14] = 0x29;
 481
 482         hid_dev = hid_allocate_device();
 483         if (IS_ERR(hid_dev)) {
 484                 ret = PTR_ERR(hid_dev);
 485                 goto probe_err1;
 486         }
 487
 488         hid_dev->ll_driver = &mousevsc_ll_driver;
 489         hid_dev->driver = &mousevsc_hid_driver;
 490         hid_dev->bus = BUS_VIRTUAL;
 491         hid_dev->vendor = input_dev->hid_dev_info.vendor;
 492         hid_dev->product = input_dev->hid_dev_info.product;
 493         hid_dev->version = input_dev->hid_dev_info.version;
 494         input_dev->hid_device = hid_dev;
 495
 496         sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
 497
 498         hid_set_drvdata(hid_dev, device);
 499
 500         ret = hid_add_device(hid_dev);
 501         if (ret)
 502                 goto probe_err1;
 503
 504
 505         ret = hid_parse(hid_dev);
 506         if (ret) {
 507                 hid_err(hid_dev, "parse failed\n");
 508                 goto probe_err2;
 509         }
 510
 511         ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
 512
 513         if (ret) {
 514                 hid_err(hid_dev, "hw start failed\n");
 515                 goto probe_err2;
 516         }
 517
 518         device_init_wakeup(&device->device, true);
 519
 520         input_dev->connected = true;
 521         input_dev->init_complete = true;
 522
 523         return ret;
 524
 525 probe_err2:
 526         hid_destroy_device(hid_dev);
 527
 528 probe_err1:
 529         vmbus_close(device->channel);
 530
 531 probe_err0:
 532         mousevsc_free_device(input_dev);
 533
 534         return ret;
 535 }
 536
 537
 538 static int mousevsc_remove(struct hv_device *dev)
 539 {
 540         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 541
 542         device_init_wakeup(&dev->device, false);
 543         vmbus_close(dev->channel);
 544         hid_hw_stop(input_dev->hid_device);
 545         hid_destroy_device(input_dev->hid_device);
 546         mousevsc_free_device(input_dev);
 547
 548         return 0;
 549 }
 550
 551 static int mousevsc_suspend(struct hv_device *dev)
 552 {
 553         vmbus_close(dev->channel);
 554
 555         return 0;
 556 }
 557
 558 static int mousevsc_resume(struct hv_device *dev)
 559 {
 560         int ret;
 561
 562         ret = vmbus_open(dev->channel,
 563                          INPUTVSC_SEND_RING_BUFFER_SIZE,
 564                          INPUTVSC_RECV_RING_BUFFER_SIZE,
 565                          NULL, 0,
 566                          mousevsc_on_channel_callback,
 567                          dev);
 568         if (ret)
 569                 return ret;
 570
 571         ret = mousevsc_connect_to_vsp(dev);
 572         return ret;
 573 }
 574
 575 static const struct hv_vmbus_device_id id_table[] = {
 576         /* Mouse guid */
 577         { HV_MOUSE_GUID, },
 578         { },
 579 };
 580
 581 MODULE_DEVICE_TABLE(vmbus, id_table);
 582
 583 static struct  hv_driver mousevsc_drv = {
 584         .name = KBUILD_MODNAME,
 585         .id_table = id_table,
 586         .probe = mousevsc_probe,
 587         .remove = mousevsc_remove,
 588         .suspend = mousevsc_suspend,
 589         .resume = mousevsc_resume,
 590         .driver = {
 591                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 592         },
 593 };
 594
 595 static int __init mousevsc_init(void)
 596 {
 597         return vmbus_driver_register(&mousevsc_drv);
 598 }
 599
 600 static void __exit mousevsc_exit(void)
 601 {
 602         vmbus_driver_unregister(&mousevsc_drv);
 603 }
 604
 605 MODULE_LICENSE("GPL");
 606 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
 607
 608 module_init(mousevsc_init);
 609 module_exit(mousevsc_exit);