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
17struct 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/*
26 * Current version
27 *
28 * History:
29 * Beta, RC < 2008/1/22 1,0
30 * RC > 2008/1/22 2,0
31 */
32#define SYNTHHID_INPUT_VERSION_MAJOR 2
33#define SYNTHHID_INPUT_VERSION_MINOR 0
34#define SYNTHHID_INPUT_VERSION (SYNTHHID_INPUT_VERSION_MINOR | \
35 (SYNTHHID_INPUT_VERSION_MAJOR << 16))
36
37
38#pragma pack(push, 1)
39/*
40 * Message types in the synthetic input protocol
41 */
42enum synthhid_msg_type {
43 SYNTH_HID_PROTOCOL_REQUEST,
44 SYNTH_HID_PROTOCOL_RESPONSE,
45 SYNTH_HID_INITIAL_DEVICE_INFO,
46 SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
47 SYNTH_HID_INPUT_REPORT,
48 SYNTH_HID_MAX
49};
50
51/*
52 * Basic message structures.
53 */
54struct synthhid_msg_hdr {
55 enum synthhid_msg_type type;
56 u32 size;
57};
58
59union synthhid_version {
60 struct {
61 u16 minor_version;
62 u16 major_version;
63 };
64 u32 version;
65};
66
67/*
68 * Protocol messages
69 */
70struct synthhid_protocol_request {
71 struct synthhid_msg_hdr header;
72 union synthhid_version version_requested;
73};
74
75struct synthhid_protocol_response {
76 struct synthhid_msg_hdr header;
77 union synthhid_version version_requested;
78 unsigned char approved;
79};
80
81struct synthhid_device_info {
82 struct synthhid_msg_hdr header;
83 struct hv_input_dev_info hid_dev_info;
84 struct hid_descriptor hid_descriptor;
85};
86
87struct synthhid_device_info_ack {
88 struct synthhid_msg_hdr header;
89 unsigned char reserved;
90};
91
92struct synthhid_input_report {
93 struct synthhid_msg_hdr header;
94 char buffer[];
95};
96
97#pragma pack(pop)
98
99#define INPUTVSC_SEND_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024)
100#define INPUTVSC_RECV_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024)
101
102
103enum pipe_prot_msg_type {
104 PIPE_MESSAGE_INVALID,
105 PIPE_MESSAGE_DATA,
106 PIPE_MESSAGE_MAXIMUM
107};
108
109
110struct pipe_prt_msg {
111 enum pipe_prot_msg_type type;
112 u32 size;
113 char data[];
114};
115
116struct mousevsc_prt_msg {
117 enum pipe_prot_msg_type type;
118 u32 size;
119 union {
120 struct synthhid_protocol_request request;
121 struct synthhid_protocol_response response;
122 struct synthhid_device_info_ack ack;
123 };
124};
125
126/*
127 * Represents an mousevsc device
128 */
129struct mousevsc_dev {
130 struct hv_device *device;
131 bool init_complete;
132 bool connected;
133 struct mousevsc_prt_msg protocol_req;
134 struct mousevsc_prt_msg protocol_resp;
135 /* Synchronize the request/response if needed */
136 struct completion wait_event;
137 int dev_info_status;
138
139 struct hid_descriptor *hid_desc;
140 unsigned char *report_desc;
141 u32 report_desc_size;
142 struct hv_input_dev_info hid_dev_info;
143 struct hid_device *hid_device;
144 u8 input_buf[HID_MAX_BUFFER_SIZE];
145};
146
147
148static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
149{
150 struct mousevsc_dev *input_dev;
151
152 input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
153
154 if (!input_dev)
155 return NULL;
156
157 input_dev->device = device;
158 hv_set_drvdata(dev: device, data: input_dev);
159 init_completion(x: &input_dev->wait_event);
160 input_dev->init_complete = false;
161
162 return input_dev;
163}
164
165static void mousevsc_free_device(struct mousevsc_dev *device)
166{
167 kfree(objp: device->hid_desc);
168 kfree(objp: device->report_desc);
169 hv_set_drvdata(dev: device->device, NULL);
170 kfree(objp: device);
171}
172
173static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
174 struct synthhid_device_info *device_info)
175{
176 int ret = 0;
177 struct hid_descriptor *desc;
178 struct mousevsc_prt_msg ack;
179
180 input_device->dev_info_status = -ENOMEM;
181
182 input_device->hid_dev_info = device_info->hid_dev_info;
183 desc = &device_info->hid_descriptor;
184 if (desc->bLength == 0)
185 goto cleanup;
186
187 /* The pointer is not NULL when we resume from hibernation */
188 kfree(objp: input_device->hid_desc);
189 input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
190
191 if (!input_device->hid_desc)
192 goto cleanup;
193
194 input_device->report_desc_size = le16_to_cpu(
195 desc->rpt_desc.wDescriptorLength);
196 if (input_device->report_desc_size == 0) {
197 input_device->dev_info_status = -EINVAL;
198 goto cleanup;
199 }
200
201 /* The pointer is not NULL when we resume from hibernation */
202 kfree(objp: input_device->report_desc);
203 input_device->report_desc = kzalloc(input_device->report_desc_size,
204 GFP_ATOMIC);
205
206 if (!input_device->report_desc) {
207 input_device->dev_info_status = -ENOMEM;
208 goto cleanup;
209 }
210
211 memcpy(input_device->report_desc,
212 ((unsigned char *)desc) + desc->bLength,
213 le16_to_cpu(desc->rpt_desc.wDescriptorLength));
214
215 /* Send the ack */
216 memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
217
218 ack.type = PIPE_MESSAGE_DATA;
219 ack.size = sizeof(struct synthhid_device_info_ack);
220
221 ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
222 ack.ack.header.size = 1;
223 ack.ack.reserved = 0;
224
225 ret = vmbus_sendpacket(channel: input_device->device->channel,
226 buffer: &ack,
227 bufferLen: sizeof(struct pipe_prt_msg) +
228 sizeof(struct synthhid_device_info_ack),
229 requestid: (unsigned long)&ack,
230 type: VM_PKT_DATA_INBAND,
231 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
232
233 if (!ret)
234 input_device->dev_info_status = 0;
235
236cleanup:
237 complete(&input_device->wait_event);
238
239 return;
240}
241
242static void mousevsc_on_receive(struct hv_device *device,
243 struct vmpacket_descriptor *packet)
244{
245 struct pipe_prt_msg *pipe_msg;
246 struct synthhid_msg_hdr *hid_msg_hdr;
247 struct mousevsc_dev *input_dev = hv_get_drvdata(dev: device);
248 struct synthhid_input_report *input_report;
249 size_t len;
250
251 pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
252 (packet->offset8 << 3));
253
254 if (pipe_msg->type != PIPE_MESSAGE_DATA)
255 return;
256
257 hid_msg_hdr = (struct synthhid_msg_hdr *)pipe_msg->data;
258
259 switch (hid_msg_hdr->type) {
260 case SYNTH_HID_PROTOCOL_RESPONSE:
261 len = struct_size(pipe_msg, data, pipe_msg->size);
262
263 /*
264 * While it will be impossible for us to protect against
265 * malicious/buggy hypervisor/host, add a check here to
266 * ensure we don't corrupt memory.
267 */
268 if (WARN_ON(len > sizeof(struct mousevsc_prt_msg)))
269 break;
270
271 memcpy(&input_dev->protocol_resp, pipe_msg, len);
272 complete(&input_dev->wait_event);
273 break;
274
275 case SYNTH_HID_INITIAL_DEVICE_INFO:
276 WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
277
278 /*
279 * Parse out the device info into device attr,
280 * hid desc and report desc
281 */
282 mousevsc_on_receive_device_info(input_device: input_dev,
283 device_info: (struct synthhid_device_info *)pipe_msg->data);
284 break;
285 case SYNTH_HID_INPUT_REPORT:
286 input_report =
287 (struct synthhid_input_report *)pipe_msg->data;
288 if (!input_dev->init_complete)
289 break;
290
291 len = min(input_report->header.size,
292 (u32)sizeof(input_dev->input_buf));
293 memcpy(input_dev->input_buf, input_report->buffer, len);
294 hid_input_report(hid: input_dev->hid_device, type: HID_INPUT_REPORT,
295 data: input_dev->input_buf, size: len, interrupt: 1);
296
297 pm_wakeup_hard_event(dev: &input_dev->device->device);
298
299 break;
300 default:
301 pr_err("unsupported hid msg type - type %d len %d\n",
302 hid_msg_hdr->type, hid_msg_hdr->size);
303 break;
304 }
305
306}
307
308static void mousevsc_on_channel_callback(void *context)
309{
310 struct hv_device *device = context;
311 struct vmpacket_descriptor *desc;
312
313 foreach_vmbus_pkt(desc, device->channel) {
314 switch (desc->type) {
315 case VM_PKT_COMP:
316 break;
317
318 case VM_PKT_DATA_INBAND:
319 mousevsc_on_receive(device, packet: desc);
320 break;
321
322 default:
323 pr_err("Unhandled packet type %d, tid %llx len %d\n",
324 desc->type, desc->trans_id, desc->len8 * 8);
325 break;
326 }
327 }
328}
329
330static int mousevsc_connect_to_vsp(struct hv_device *device)
331{
332 int ret = 0;
333 unsigned long t;
334 struct mousevsc_dev *input_dev = hv_get_drvdata(dev: device);
335 struct mousevsc_prt_msg *request;
336 struct mousevsc_prt_msg *response;
337
338 reinit_completion(x: &input_dev->wait_event);
339
340 request = &input_dev->protocol_req;
341 memset(request, 0, sizeof(struct mousevsc_prt_msg));
342
343 request->type = PIPE_MESSAGE_DATA;
344 request->size = sizeof(struct synthhid_protocol_request);
345 request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
346 request->request.header.size = sizeof(unsigned int);
347 request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
348
349 ret = vmbus_sendpacket(channel: device->channel, buffer: request,
350 bufferLen: sizeof(struct pipe_prt_msg) +
351 sizeof(struct synthhid_protocol_request),
352 requestid: (unsigned long)request,
353 type: VM_PKT_DATA_INBAND,
354 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
355 if (ret)
356 goto cleanup;
357
358 t = wait_for_completion_timeout(x: &input_dev->wait_event, timeout: 5*HZ);
359 if (!t) {
360 ret = -ETIMEDOUT;
361 goto cleanup;
362 }
363
364 response = &input_dev->protocol_resp;
365
366 if (!response->response.approved) {
367 pr_err("synthhid protocol request failed (version %d)\n",
368 SYNTHHID_INPUT_VERSION);
369 ret = -ENODEV;
370 goto cleanup;
371 }
372
373 t = wait_for_completion_timeout(x: &input_dev->wait_event, timeout: 5*HZ);
374 if (!t) {
375 ret = -ETIMEDOUT;
376 goto cleanup;
377 }
378
379 /*
380 * We should have gotten the device attr, hid desc and report
381 * desc at this point
382 */
383 ret = input_dev->dev_info_status;
384
385cleanup:
386 return ret;
387}
388
389static int mousevsc_hid_parse(struct hid_device *hid)
390{
391 struct hv_device *dev = hid_get_drvdata(hdev: hid);
392 struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
393
394 return hid_parse_report(hid, start: input_dev->report_desc,
395 size: input_dev->report_desc_size);
396}
397
398static int mousevsc_hid_open(struct hid_device *hid)
399{
400 return 0;
401}
402
403static int mousevsc_hid_start(struct hid_device *hid)
404{
405 return 0;
406}
407
408static void mousevsc_hid_close(struct hid_device *hid)
409{
410}
411
412static void mousevsc_hid_stop(struct hid_device *hid)
413{
414}
415
416static int mousevsc_hid_raw_request(struct hid_device *hid,
417 unsigned char report_num,
418 __u8 *buf, size_t len,
419 unsigned char rtype,
420 int reqtype)
421{
422 return 0;
423}
424
425static int mousevsc_hid_probe(struct hid_device *hid_dev, const struct hid_device_id *id)
426{
427 int ret;
428
429 ret = hid_parse(hdev: hid_dev);
430 if (ret) {
431 hid_err(hid_dev, "parse failed\n");
432 return ret;
433 }
434
435 ret = hid_hw_start(hdev: hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
436 if (ret) {
437 hid_err(hid_dev, "hw start failed\n");
438 return ret;
439 }
440
441 return 0;
442}
443
444static const struct hid_ll_driver mousevsc_ll_driver = {
445 .parse = mousevsc_hid_parse,
446 .open = mousevsc_hid_open,
447 .close = mousevsc_hid_close,
448 .start = mousevsc_hid_start,
449 .stop = mousevsc_hid_stop,
450 .raw_request = mousevsc_hid_raw_request,
451};
452
453static const struct hid_device_id mousevsc_devices[] = {
454 { HID_DEVICE(BUS_VIRTUAL, HID_GROUP_ANY, 0x045E, 0x0621) },
455 { }
456};
457
458static struct hid_driver mousevsc_hid_driver = {
459 .name = "hid-hyperv",
460 .id_table = mousevsc_devices,
461 .probe = mousevsc_hid_probe,
462};
463
464static int mousevsc_probe(struct hv_device *device,
465 const struct hv_vmbus_device_id *dev_id)
466{
467 int ret;
468 struct mousevsc_dev *input_dev;
469 struct hid_device *hid_dev;
470
471 input_dev = mousevsc_alloc_device(device);
472
473 if (!input_dev)
474 return -ENOMEM;
475
476 ret = vmbus_open(channel: device->channel,
477 INPUTVSC_SEND_RING_BUFFER_SIZE,
478 INPUTVSC_RECV_RING_BUFFER_SIZE,
479 NULL,
480 userdatalen: 0,
481 onchannel_callback: mousevsc_on_channel_callback,
482 context: device
483 );
484
485 if (ret)
486 goto probe_err0;
487
488 ret = mousevsc_connect_to_vsp(device);
489
490 if (ret)
491 goto probe_err1;
492
493 /* workaround SA-167 */
494 if (input_dev->report_desc[14] == 0x25)
495 input_dev->report_desc[14] = 0x29;
496
497 hid_dev = hid_allocate_device();
498 if (IS_ERR(ptr: hid_dev)) {
499 ret = PTR_ERR(ptr: hid_dev);
500 goto probe_err1;
501 }
502
503 hid_dev->ll_driver = &mousevsc_ll_driver;
504 hid_dev->bus = BUS_VIRTUAL;
505 hid_dev->vendor = input_dev->hid_dev_info.vendor;
506 hid_dev->product = input_dev->hid_dev_info.product;
507 hid_dev->version = input_dev->hid_dev_info.version;
508 input_dev->hid_device = hid_dev;
509
510 sprintf(buf: hid_dev->name, fmt: "%s", "Microsoft Vmbus HID-compliant Mouse");
511
512 hid_set_drvdata(hdev: hid_dev, data: device);
513
514 ret = hid_add_device(hid_dev);
515 if (ret)
516 goto probe_err2;
517
518 device_init_wakeup(dev: &device->device, enable: true);
519
520 input_dev->connected = true;
521 input_dev->init_complete = true;
522
523 return ret;
524
525probe_err2:
526 hid_destroy_device(hid_dev);
527
528probe_err1:
529 vmbus_close(channel: device->channel);
530
531probe_err0:
532 mousevsc_free_device(device: input_dev);
533
534 return ret;
535}
536
537
538static void mousevsc_remove(struct hv_device *dev)
539{
540 struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
541
542 device_init_wakeup(dev: &dev->device, enable: false);
543 vmbus_close(channel: dev->channel);
544 hid_hw_stop(hdev: input_dev->hid_device);
545 hid_destroy_device(input_dev->hid_device);
546 mousevsc_free_device(device: input_dev);
547}
548
549static int mousevsc_suspend(struct hv_device *dev)
550{
551 vmbus_close(channel: dev->channel);
552
553 return 0;
554}
555
556static int mousevsc_resume(struct hv_device *dev)
557{
558 int ret;
559
560 ret = vmbus_open(channel: dev->channel,
561 INPUTVSC_SEND_RING_BUFFER_SIZE,
562 INPUTVSC_RECV_RING_BUFFER_SIZE,
563 NULL, userdatalen: 0,
564 onchannel_callback: mousevsc_on_channel_callback,
565 context: dev);
566 if (ret)
567 return ret;
568
569 ret = mousevsc_connect_to_vsp(device: dev);
570 return ret;
571}
572
573static const struct hv_vmbus_device_id id_table[] = {
574 /* Mouse guid */
575 { HV_MOUSE_GUID, },
576 { },
577};
578
579MODULE_DEVICE_TABLE(vmbus, id_table);
580
581static struct hv_driver mousevsc_drv = {
582 .name = KBUILD_MODNAME,
583 .id_table = id_table,
584 .probe = mousevsc_probe,
585 .remove = mousevsc_remove,
586 .suspend = mousevsc_suspend,
587 .resume = mousevsc_resume,
588 .driver = {
589 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
590 },
591};
592
593static int __init mousevsc_init(void)
594{
595 int ret;
596
597 ret = hid_register_driver(&mousevsc_hid_driver);
598 if (ret)
599 return ret;
600
601 ret = vmbus_driver_register(&mousevsc_drv);
602 if (ret)
603 hid_unregister_driver(&mousevsc_hid_driver);
604
605 return ret;
606}
607
608static void __exit mousevsc_exit(void)
609{
610 vmbus_driver_unregister(hv_driver: &mousevsc_drv);
611 hid_unregister_driver(&mousevsc_hid_driver);
612}
613
614MODULE_LICENSE("GPL");
615MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
616
617module_init(mousevsc_init);
618module_exit(mousevsc_exit);
619

source code of linux/drivers/hid/hid-hyperv.c