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 = desc->desc[0].wDescriptorLength;
 203         if (input_device->report_desc_size == 0) {
 204                 input_device->dev_info_status = -EINVAL;
 205                 goto cleanup;
 206         }
 207
 208         /* The pointer is not NULL when we resume from hibernation */
 209         kfree(input_device->report_desc);
 210         input_device->report_desc = kzalloc(input_device->report_desc_size,
 211                                           GFP_ATOMIC);
 212
 213         if (!input_device->report_desc) {
 214                 input_device->dev_info_status = -ENOMEM;
 215                 goto cleanup;
 216         }
 217
 218         memcpy(input_device->report_desc,
 219                ((unsigned char *)desc) + desc->bLength,
 220                desc->desc[0].wDescriptorLength);
 221
 222         /* Send the ack */
 223         memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
 224
 225         ack.type = PIPE_MESSAGE_DATA;
 226         ack.size = sizeof(struct synthhid_device_info_ack);
 227
 228         ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
 229         ack.ack.header.size = 1;
 230         ack.ack.reserved = 0;
 231
 232         ret = vmbus_sendpacket(input_device->device->channel,
 233                         &ack,
 234                         sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
 235                         sizeof(struct synthhid_device_info_ack),
 236                         (unsigned long)&ack,
 237                         VM_PKT_DATA_INBAND,
 238                         VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 239
 240         if (!ret)
 241                 input_device->dev_info_status = 0;
 242
 243 cleanup:
 244         complete(&input_device->wait_event);
 245
 246         return;
 247 }
 248
 249 static void mousevsc_on_receive(struct hv_device *device,
 250                                 struct vmpacket_descriptor *packet)
 251 {
 252         struct pipe_prt_msg *pipe_msg;
 253         struct synthhid_msg *hid_msg;
 254         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 255         struct synthhid_input_report *input_report;
 256         size_t len;
 257
 258         pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
 259                                                 (packet->offset8 << 3));
 260
 261         if (pipe_msg->type != PIPE_MESSAGE_DATA)
 262                 return;
 263
 264         hid_msg = (struct synthhid_msg *)pipe_msg->data;
 265
 266         switch (hid_msg->header.type) {
 267         case SYNTH_HID_PROTOCOL_RESPONSE:
 268                 /*
 269                  * While it will be impossible for us to protect against
 270                  * malicious/buggy hypervisor/host, add a check here to
 271                  * ensure we don't corrupt memory.
 272                  */
 273                 if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
 274                         - sizeof(unsigned char))
 275                         > sizeof(struct mousevsc_prt_msg)) {
 276                         WARN_ON(1);
 277                         break;
 278                 }
 279
 280                 memcpy(&input_dev->protocol_resp, pipe_msg,
 281                        pipe_msg->size + sizeof(struct pipe_prt_msg) -
 282                        sizeof(unsigned char));
 283                 complete(&input_dev->wait_event);
 284                 break;
 285
 286         case SYNTH_HID_INITIAL_DEVICE_INFO:
 287                 WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
 288
 289                 /*
 290                  * Parse out the device info into device attr,
 291                  * hid desc and report desc
 292                  */
 293                 mousevsc_on_receive_device_info(input_dev,
 294                         (struct synthhid_device_info *)pipe_msg->data);
 295                 break;
 296         case SYNTH_HID_INPUT_REPORT:
 297                 input_report =
 298                         (struct synthhid_input_report *)pipe_msg->data;
 299                 if (!input_dev->init_complete)
 300                         break;
 301
 302                 len = min(input_report->header.size,
 303                           (u32)sizeof(input_dev->input_buf));
 304                 memcpy(input_dev->input_buf, input_report->buffer, len);
 305                 hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
 306                                  input_dev->input_buf, len, 1);
 307
 308                 pm_wakeup_hard_event(&input_dev->device->device);
 309
 310                 break;
 311         default:
 312                 pr_err("unsupported hid msg type - type %d len %d\n",
 313                        hid_msg->header.type, hid_msg->header.size);
 314                 break;
 315         }
 316
 317 }
 318
 319 static void mousevsc_on_channel_callback(void *context)
 320 {
 321         struct hv_device *device = context;
 322         struct vmpacket_descriptor *desc;
 323
 324         foreach_vmbus_pkt(desc, device->channel) {
 325                 switch (desc->type) {
 326                 case VM_PKT_COMP:
 327                         break;
 328
 329                 case VM_PKT_DATA_INBAND:
 330                         mousevsc_on_receive(device, desc);
 331                         break;
 332
 333                 default:
 334                         pr_err("Unhandled packet type %d, tid %llx len %d\n",
 335                                desc->type, desc->trans_id, desc->len8 * 8);
 336                         break;
 337                 }
 338         }
 339 }
 340
 341 static int mousevsc_connect_to_vsp(struct hv_device *device)
 342 {
 343         int ret = 0;
 344         unsigned long t;
 345         struct mousevsc_dev *input_dev = hv_get_drvdata(device);
 346         struct mousevsc_prt_msg *request;
 347         struct mousevsc_prt_msg *response;
 348
 349         reinit_completion(&input_dev->wait_event);
 350
 351         request = &input_dev->protocol_req;
 352         memset(request, 0, sizeof(struct mousevsc_prt_msg));
 353
 354         request->type = PIPE_MESSAGE_DATA;
 355         request->size = sizeof(struct synthhid_protocol_request);
 356         request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
 357         request->request.header.size = sizeof(unsigned int);
 358         request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
 359
 360         ret = vmbus_sendpacket(device->channel, request,
 361                                 sizeof(struct pipe_prt_msg) -
 362                                 sizeof(unsigned char) +
 363                                 sizeof(struct synthhid_protocol_request),
 364                                 (unsigned long)request,
 365                                 VM_PKT_DATA_INBAND,
 366                                 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 367         if (ret)
 368                 goto cleanup;
 369
 370         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 371         if (!t) {
 372                 ret = -ETIMEDOUT;
 373                 goto cleanup;
 374         }
 375
 376         response = &input_dev->protocol_resp;
 377
 378         if (!response->response.approved) {
 379                 pr_err("synthhid protocol request failed (version %d)\n",
 380                        SYNTHHID_INPUT_VERSION);
 381                 ret = -ENODEV;
 382                 goto cleanup;
 383         }
 384
 385         t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
 386         if (!t) {
 387                 ret = -ETIMEDOUT;
 388                 goto cleanup;
 389         }
 390
 391         /*
 392          * We should have gotten the device attr, hid desc and report
 393          * desc at this point
 394          */
 395         ret = input_dev->dev_info_status;
 396
 397 cleanup:
 398         return ret;
 399 }
 400
 401 static int mousevsc_hid_parse(struct hid_device *hid)
 402 {
 403         struct hv_device *dev = hid_get_drvdata(hid);
 404         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 405
 406         return hid_parse_report(hid, input_dev->report_desc,
 407                                 input_dev->report_desc_size);
 408 }
 409
 410 static int mousevsc_hid_open(struct hid_device *hid)
 411 {
 412         return 0;
 413 }
 414
 415 static int mousevsc_hid_start(struct hid_device *hid)
 416 {
 417         return 0;
 418 }
 419
 420 static void mousevsc_hid_close(struct hid_device *hid)
 421 {
 422 }
 423
 424 static void mousevsc_hid_stop(struct hid_device *hid)
 425 {
 426 }
 427
 428 static int mousevsc_hid_raw_request(struct hid_device *hid,
 429                                     unsigned char report_num,
 430                                     __u8 *buf, size_t len,
 431                                     unsigned char rtype,
 432                                     int reqtype)
 433 {
 434         return 0;
 435 }
 436
 437 static struct hid_ll_driver mousevsc_ll_driver = {
 438         .parse = mousevsc_hid_parse,
 439         .open = mousevsc_hid_open,
 440         .close = mousevsc_hid_close,
 441         .start = mousevsc_hid_start,
 442         .stop = mousevsc_hid_stop,
 443         .raw_request = mousevsc_hid_raw_request,
 444 };
 445
 446 static struct hid_driver mousevsc_hid_driver;
 447
 448 static int mousevsc_probe(struct hv_device *device,
 449                         const struct hv_vmbus_device_id *dev_id)
 450 {
 451         int ret;
 452         struct mousevsc_dev *input_dev;
 453         struct hid_device *hid_dev;
 454
 455         input_dev = mousevsc_alloc_device(device);
 456
 457         if (!input_dev)
 458                 return -ENOMEM;
 459
 460         ret = vmbus_open(device->channel,
 461                 INPUTVSC_SEND_RING_BUFFER_SIZE,
 462                 INPUTVSC_RECV_RING_BUFFER_SIZE,
 463                 NULL,
 464                 0,
 465                 mousevsc_on_channel_callback,
 466                 device
 467                 );
 468
 469         if (ret)
 470                 goto probe_err0;
 471
 472         ret = mousevsc_connect_to_vsp(device);
 473
 474         if (ret)
 475                 goto probe_err1;
 476
 477         /* workaround SA-167 */
 478         if (input_dev->report_desc[14] == 0x25)
 479                 input_dev->report_desc[14] = 0x29;
 480
 481         hid_dev = hid_allocate_device();
 482         if (IS_ERR(hid_dev)) {
 483                 ret = PTR_ERR(hid_dev);
 484                 goto probe_err1;
 485         }
 486
 487         hid_dev->ll_driver = &mousevsc_ll_driver;
 488         hid_dev->driver = &mousevsc_hid_driver;
 489         hid_dev->bus = BUS_VIRTUAL;
 490         hid_dev->vendor = input_dev->hid_dev_info.vendor;
 491         hid_dev->product = input_dev->hid_dev_info.product;
 492         hid_dev->version = input_dev->hid_dev_info.version;
 493         input_dev->hid_device = hid_dev;
 494
 495         sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
 496
 497         hid_set_drvdata(hid_dev, device);
 498
 499         ret = hid_add_device(hid_dev);
 500         if (ret)
 501                 goto probe_err1;
 502
 503
 504         ret = hid_parse(hid_dev);
 505         if (ret) {
 506                 hid_err(hid_dev, "parse failed\n");
 507                 goto probe_err2;
 508         }
 509
 510         ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
 511
 512         if (ret) {
 513                 hid_err(hid_dev, "hw start failed\n");
 514                 goto probe_err2;
 515         }
 516
 517         device_init_wakeup(&device->device, true);
 518
 519         input_dev->connected = true;
 520         input_dev->init_complete = true;
 521
 522         return ret;
 523
 524 probe_err2:
 525         hid_destroy_device(hid_dev);
 526
 527 probe_err1:
 528         vmbus_close(device->channel);
 529
 530 probe_err0:
 531         mousevsc_free_device(input_dev);
 532
 533         return ret;
 534 }
 535
 536
 537 static int mousevsc_remove(struct hv_device *dev)
 538 {
 539         struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 540
 541         device_init_wakeup(&dev->device, false);
 542         vmbus_close(dev->channel);
 543         hid_hw_stop(input_dev->hid_device);
 544         hid_destroy_device(input_dev->hid_device);
 545         mousevsc_free_device(input_dev);
 546
 547         return 0;
 548 }
 549
 550 static int mousevsc_suspend(struct hv_device *dev)
 551 {
 552         vmbus_close(dev->channel);
 553
 554         return 0;
 555 }
 556
 557 static int mousevsc_resume(struct hv_device *dev)
 558 {
 559         int ret;
 560
 561         ret = vmbus_open(dev->channel,
 562                          INPUTVSC_SEND_RING_BUFFER_SIZE,
 563                          INPUTVSC_RECV_RING_BUFFER_SIZE,
 564                          NULL, 0,
 565                          mousevsc_on_channel_callback,
 566                          dev);
 567         if (ret)
 568                 return ret;
 569
 570         ret = mousevsc_connect_to_vsp(dev);
 571         return ret;
 572 }
 573
 574 static const struct hv_vmbus_device_id id_table[] = {
 575         /* Mouse guid */
 576         { HV_MOUSE_GUID, },
 577         { },
 578 };
 579
 580 MODULE_DEVICE_TABLE(vmbus, id_table);
 581
 582 static struct  hv_driver mousevsc_drv = {
 583         .name = KBUILD_MODNAME,
 584         .id_table = id_table,
 585         .probe = mousevsc_probe,
 586         .remove = mousevsc_remove,
 587         .suspend = mousevsc_suspend,
 588         .resume = mousevsc_resume,
 589         .driver = {
 590                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 591         },
 592 };
 593
 594 static int __init mousevsc_init(void)
 595 {
 596         return vmbus_driver_register(&mousevsc_drv);
 597 }
 598
 599 static void __exit mousevsc_exit(void)
 600 {
 601         vmbus_driver_unregister(&mousevsc_drv);
 602 }
 603
 604 MODULE_LICENSE("GPL");
 605 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
 606
 607 module_init(mousevsc_init);
 608 module_exit(mousevsc_exit);