xref: /linux/drivers/hid/hid-hyperv.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  *  Copyright (c) 2009, Citrix Systems, Inc.
3  *  Copyright (c) 2010, Microsoft Corporation.
4  *  Copyright (c) 2011, Novell Inc.
5  *
6  *  This program is free software; you can redistribute it and/or modify it
7  *  under the terms and conditions of the GNU General Public License,
8  *  version 2, as published by the Free Software Foundation.
9  *
10  *  This program is distributed in the hope it will be useful, but WITHOUT
11  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  *  more details.
14  */
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/device.h>
18 #include <linux/completion.h>
19 #include <linux/input.h>
20 #include <linux/hid.h>
21 #include <linux/hiddev.h>
22 #include <linux/hyperv.h>
23 
24 
25 struct hv_input_dev_info {
26 	unsigned int size;
27 	unsigned short vendor;
28 	unsigned short product;
29 	unsigned short version;
30 	unsigned short reserved[11];
31 };
32 
33 /* The maximum size of a synthetic input message. */
34 #define SYNTHHID_MAX_INPUT_REPORT_SIZE 16
35 
36 /*
37  * Current version
38  *
39  * History:
40  * Beta, RC < 2008/1/22        1,0
41  * RC > 2008/1/22              2,0
42  */
43 #define SYNTHHID_INPUT_VERSION_MAJOR	2
44 #define SYNTHHID_INPUT_VERSION_MINOR	0
45 #define SYNTHHID_INPUT_VERSION		(SYNTHHID_INPUT_VERSION_MINOR | \
46 					 (SYNTHHID_INPUT_VERSION_MAJOR << 16))
47 
48 
49 #pragma pack(push, 1)
50 /*
51  * Message types in the synthetic input protocol
52  */
53 enum synthhid_msg_type {
54 	SYNTH_HID_PROTOCOL_REQUEST,
55 	SYNTH_HID_PROTOCOL_RESPONSE,
56 	SYNTH_HID_INITIAL_DEVICE_INFO,
57 	SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
58 	SYNTH_HID_INPUT_REPORT,
59 	SYNTH_HID_MAX
60 };
61 
62 /*
63  * Basic message structures.
64  */
65 struct synthhid_msg_hdr {
66 	enum synthhid_msg_type type;
67 	u32 size;
68 };
69 
70 struct synthhid_msg {
71 	struct synthhid_msg_hdr header;
72 	char data[1]; /* Enclosed message */
73 };
74 
75 union synthhid_version {
76 	struct {
77 		u16 minor_version;
78 		u16 major_version;
79 	};
80 	u32 version;
81 };
82 
83 /*
84  * Protocol messages
85  */
86 struct synthhid_protocol_request {
87 	struct synthhid_msg_hdr header;
88 	union synthhid_version version_requested;
89 };
90 
91 struct synthhid_protocol_response {
92 	struct synthhid_msg_hdr header;
93 	union synthhid_version version_requested;
94 	unsigned char approved;
95 };
96 
97 struct synthhid_device_info {
98 	struct synthhid_msg_hdr header;
99 	struct hv_input_dev_info hid_dev_info;
100 	struct hid_descriptor hid_descriptor;
101 };
102 
103 struct synthhid_device_info_ack {
104 	struct synthhid_msg_hdr header;
105 	unsigned char reserved;
106 };
107 
108 struct synthhid_input_report {
109 	struct synthhid_msg_hdr header;
110 	char buffer[1];
111 };
112 
113 #pragma pack(pop)
114 
115 #define INPUTVSC_SEND_RING_BUFFER_SIZE		(10*PAGE_SIZE)
116 #define INPUTVSC_RECV_RING_BUFFER_SIZE		(10*PAGE_SIZE)
117 
118 
119 enum pipe_prot_msg_type {
120 	PIPE_MESSAGE_INVALID,
121 	PIPE_MESSAGE_DATA,
122 	PIPE_MESSAGE_MAXIMUM
123 };
124 
125 
126 struct pipe_prt_msg {
127 	enum pipe_prot_msg_type type;
128 	u32 size;
129 	char data[1];
130 };
131 
132 struct  mousevsc_prt_msg {
133 	enum pipe_prot_msg_type type;
134 	u32 size;
135 	union {
136 		struct synthhid_protocol_request request;
137 		struct synthhid_protocol_response response;
138 		struct synthhid_device_info_ack ack;
139 	};
140 };
141 
142 /*
143  * Represents an mousevsc device
144  */
145 struct mousevsc_dev {
146 	struct hv_device	*device;
147 	bool			init_complete;
148 	bool			connected;
149 	struct mousevsc_prt_msg	protocol_req;
150 	struct mousevsc_prt_msg	protocol_resp;
151 	/* Synchronize the request/response if needed */
152 	struct completion	wait_event;
153 	int			dev_info_status;
154 
155 	struct hid_descriptor	*hid_desc;
156 	unsigned char		*report_desc;
157 	u32			report_desc_size;
158 	struct hv_input_dev_info hid_dev_info;
159 	struct hid_device       *hid_device;
160 };
161 
162 
163 static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
164 {
165 	struct mousevsc_dev *input_dev;
166 
167 	input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
168 
169 	if (!input_dev)
170 		return NULL;
171 
172 	input_dev->device = device;
173 	hv_set_drvdata(device, input_dev);
174 	init_completion(&input_dev->wait_event);
175 	input_dev->init_complete = false;
176 
177 	return input_dev;
178 }
179 
180 static void mousevsc_free_device(struct mousevsc_dev *device)
181 {
182 	kfree(device->hid_desc);
183 	kfree(device->report_desc);
184 	hv_set_drvdata(device->device, NULL);
185 	kfree(device);
186 }
187 
188 static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
189 				struct synthhid_device_info *device_info)
190 {
191 	int ret = 0;
192 	struct hid_descriptor *desc;
193 	struct mousevsc_prt_msg ack;
194 
195 	input_device->dev_info_status = -ENOMEM;
196 
197 	input_device->hid_dev_info = device_info->hid_dev_info;
198 	desc = &device_info->hid_descriptor;
199 	if (desc->bLength == 0)
200 		goto cleanup;
201 
202 	input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
203 
204 	if (!input_device->hid_desc)
205 		goto cleanup;
206 
207 	input_device->report_desc_size = desc->desc[0].wDescriptorLength;
208 	if (input_device->report_desc_size == 0) {
209 		input_device->dev_info_status = -EINVAL;
210 		goto cleanup;
211 	}
212 
213 	input_device->report_desc = kzalloc(input_device->report_desc_size,
214 					  GFP_ATOMIC);
215 
216 	if (!input_device->report_desc) {
217 		input_device->dev_info_status = -ENOMEM;
218 		goto cleanup;
219 	}
220 
221 	memcpy(input_device->report_desc,
222 	       ((unsigned char *)desc) + desc->bLength,
223 	       desc->desc[0].wDescriptorLength);
224 
225 	/* Send the ack */
226 	memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
227 
228 	ack.type = PIPE_MESSAGE_DATA;
229 	ack.size = sizeof(struct synthhid_device_info_ack);
230 
231 	ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
232 	ack.ack.header.size = 1;
233 	ack.ack.reserved = 0;
234 
235 	ret = vmbus_sendpacket(input_device->device->channel,
236 			&ack,
237 			sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
238 			sizeof(struct synthhid_device_info_ack),
239 			(unsigned long)&ack,
240 			VM_PKT_DATA_INBAND,
241 			VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
242 
243 	if (!ret)
244 		input_device->dev_info_status = 0;
245 
246 cleanup:
247 	complete(&input_device->wait_event);
248 
249 	return;
250 }
251 
252 static void mousevsc_on_receive(struct hv_device *device,
253 				struct vmpacket_descriptor *packet)
254 {
255 	struct pipe_prt_msg *pipe_msg;
256 	struct synthhid_msg *hid_msg;
257 	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
258 	struct synthhid_input_report *input_report;
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 		hid_input_report(input_dev->hid_device,
304 				HID_INPUT_REPORT, input_report->buffer,
305 				input_report->header.size, 1);
306 		break;
307 	default:
308 		pr_err("unsupported hid msg type - type %d len %d",
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 	int 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 struct hid_ll_driver mousevsc_ll_driver = {
459 	.parse = mousevsc_hid_parse,
460 	.open = mousevsc_hid_open,
461 	.close = mousevsc_hid_close,
462 	.start = mousevsc_hid_start,
463 	.stop = mousevsc_hid_stop,
464 };
465 
466 static struct hid_driver mousevsc_hid_driver;
467 
468 static int mousevsc_probe(struct hv_device *device,
469 			const struct hv_vmbus_device_id *dev_id)
470 {
471 	int ret;
472 	struct mousevsc_dev *input_dev;
473 	struct hid_device *hid_dev;
474 
475 	input_dev = mousevsc_alloc_device(device);
476 
477 	if (!input_dev)
478 		return -ENOMEM;
479 
480 	ret = vmbus_open(device->channel,
481 		INPUTVSC_SEND_RING_BUFFER_SIZE,
482 		INPUTVSC_RECV_RING_BUFFER_SIZE,
483 		NULL,
484 		0,
485 		mousevsc_on_channel_callback,
486 		device
487 		);
488 
489 	if (ret)
490 		goto probe_err0;
491 
492 	ret = mousevsc_connect_to_vsp(device);
493 
494 	if (ret)
495 		goto probe_err1;
496 
497 	/* workaround SA-167 */
498 	if (input_dev->report_desc[14] == 0x25)
499 		input_dev->report_desc[14] = 0x29;
500 
501 	hid_dev = hid_allocate_device();
502 	if (IS_ERR(hid_dev)) {
503 		ret = PTR_ERR(hid_dev);
504 		goto probe_err1;
505 	}
506 
507 	hid_dev->ll_driver = &mousevsc_ll_driver;
508 	hid_dev->driver = &mousevsc_hid_driver;
509 	hid_dev->bus = BUS_VIRTUAL;
510 	hid_dev->vendor = input_dev->hid_dev_info.vendor;
511 	hid_dev->product = input_dev->hid_dev_info.product;
512 	hid_dev->version = input_dev->hid_dev_info.version;
513 	input_dev->hid_device = hid_dev;
514 
515 	sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
516 
517 	hid_set_drvdata(hid_dev, device);
518 
519 	ret = hid_add_device(hid_dev);
520 	if (ret)
521 		goto probe_err1;
522 
523 
524 	ret = hid_parse(hid_dev);
525 	if (ret) {
526 		hid_err(hid_dev, "parse failed\n");
527 		goto probe_err2;
528 	}
529 
530 	ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
531 
532 	if (ret) {
533 		hid_err(hid_dev, "hw start failed\n");
534 		goto probe_err2;
535 	}
536 
537 	input_dev->connected = true;
538 	input_dev->init_complete = true;
539 
540 	return ret;
541 
542 probe_err2:
543 	hid_destroy_device(hid_dev);
544 
545 probe_err1:
546 	vmbus_close(device->channel);
547 
548 probe_err0:
549 	mousevsc_free_device(input_dev);
550 
551 	return ret;
552 }
553 
554 
555 static int mousevsc_remove(struct hv_device *dev)
556 {
557 	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
558 
559 	vmbus_close(dev->channel);
560 	hid_hw_stop(input_dev->hid_device);
561 	hid_destroy_device(input_dev->hid_device);
562 	mousevsc_free_device(input_dev);
563 
564 	return 0;
565 }
566 
567 static const struct hv_vmbus_device_id id_table[] = {
568 	/* Mouse guid */
569 	{ HV_MOUSE_GUID, },
570 	{ },
571 };
572 
573 MODULE_DEVICE_TABLE(vmbus, id_table);
574 
575 static struct  hv_driver mousevsc_drv = {
576 	.name = KBUILD_MODNAME,
577 	.id_table = id_table,
578 	.probe = mousevsc_probe,
579 	.remove = mousevsc_remove,
580 };
581 
582 static int __init mousevsc_init(void)
583 {
584 	return vmbus_driver_register(&mousevsc_drv);
585 }
586 
587 static void __exit mousevsc_exit(void)
588 {
589 	vmbus_driver_unregister(&mousevsc_drv);
590 }
591 
592 MODULE_LICENSE("GPL");
593 module_init(mousevsc_init);
594 module_exit(mousevsc_exit);
595