xref: /linux/drivers/hid/hid-hyperv.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 	u8			input_buf[HID_MAX_BUFFER_SIZE];
161 };
162 
163 
164 static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
165 {
166 	struct mousevsc_dev *input_dev;
167 
168 	input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
169 
170 	if (!input_dev)
171 		return NULL;
172 
173 	input_dev->device = device;
174 	hv_set_drvdata(device, input_dev);
175 	init_completion(&input_dev->wait_event);
176 	input_dev->init_complete = false;
177 
178 	return input_dev;
179 }
180 
181 static void mousevsc_free_device(struct mousevsc_dev *device)
182 {
183 	kfree(device->hid_desc);
184 	kfree(device->report_desc);
185 	hv_set_drvdata(device->device, NULL);
186 	kfree(device);
187 }
188 
189 static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
190 				struct synthhid_device_info *device_info)
191 {
192 	int ret = 0;
193 	struct hid_descriptor *desc;
194 	struct mousevsc_prt_msg ack;
195 
196 	input_device->dev_info_status = -ENOMEM;
197 
198 	input_device->hid_dev_info = device_info->hid_dev_info;
199 	desc = &device_info->hid_descriptor;
200 	if (desc->bLength == 0)
201 		goto cleanup;
202 
203 	input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
204 
205 	if (!input_device->hid_desc)
206 		goto cleanup;
207 
208 	input_device->report_desc_size = desc->desc[0].wDescriptorLength;
209 	if (input_device->report_desc_size == 0) {
210 		input_device->dev_info_status = -EINVAL;
211 		goto cleanup;
212 	}
213 
214 	input_device->report_desc = kzalloc(input_device->report_desc_size,
215 					  GFP_ATOMIC);
216 
217 	if (!input_device->report_desc) {
218 		input_device->dev_info_status = -ENOMEM;
219 		goto cleanup;
220 	}
221 
222 	memcpy(input_device->report_desc,
223 	       ((unsigned char *)desc) + desc->bLength,
224 	       desc->desc[0].wDescriptorLength);
225 
226 	/* Send the ack */
227 	memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
228 
229 	ack.type = PIPE_MESSAGE_DATA;
230 	ack.size = sizeof(struct synthhid_device_info_ack);
231 
232 	ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
233 	ack.ack.header.size = 1;
234 	ack.ack.reserved = 0;
235 
236 	ret = vmbus_sendpacket(input_device->device->channel,
237 			&ack,
238 			sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
239 			sizeof(struct synthhid_device_info_ack),
240 			(unsigned long)&ack,
241 			VM_PKT_DATA_INBAND,
242 			VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
243 
244 	if (!ret)
245 		input_device->dev_info_status = 0;
246 
247 cleanup:
248 	complete(&input_device->wait_event);
249 
250 	return;
251 }
252 
253 static void mousevsc_on_receive(struct hv_device *device,
254 				struct vmpacket_descriptor *packet)
255 {
256 	struct pipe_prt_msg *pipe_msg;
257 	struct synthhid_msg *hid_msg;
258 	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
259 	struct synthhid_input_report *input_report;
260 	size_t len;
261 
262 	pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
263 						(packet->offset8 << 3));
264 
265 	if (pipe_msg->type != PIPE_MESSAGE_DATA)
266 		return;
267 
268 	hid_msg = (struct synthhid_msg *)pipe_msg->data;
269 
270 	switch (hid_msg->header.type) {
271 	case SYNTH_HID_PROTOCOL_RESPONSE:
272 		/*
273 		 * While it will be impossible for us to protect against
274 		 * malicious/buggy hypervisor/host, add a check here to
275 		 * ensure we don't corrupt memory.
276 		 */
277 		if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
278 			- sizeof(unsigned char))
279 			> sizeof(struct mousevsc_prt_msg)) {
280 			WARN_ON(1);
281 			break;
282 		}
283 
284 		memcpy(&input_dev->protocol_resp, pipe_msg,
285 		       pipe_msg->size + sizeof(struct pipe_prt_msg) -
286 		       sizeof(unsigned char));
287 		complete(&input_dev->wait_event);
288 		break;
289 
290 	case SYNTH_HID_INITIAL_DEVICE_INFO:
291 		WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
292 
293 		/*
294 		 * Parse out the device info into device attr,
295 		 * hid desc and report desc
296 		 */
297 		mousevsc_on_receive_device_info(input_dev,
298 			(struct synthhid_device_info *)pipe_msg->data);
299 		break;
300 	case SYNTH_HID_INPUT_REPORT:
301 		input_report =
302 			(struct synthhid_input_report *)pipe_msg->data;
303 		if (!input_dev->init_complete)
304 			break;
305 
306 		len = min(input_report->header.size,
307 			  (u32)sizeof(input_dev->input_buf));
308 		memcpy(input_dev->input_buf, input_report->buffer, len);
309 		hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
310 				 input_dev->input_buf, len, 1);
311 
312 		pm_wakeup_event(&input_dev->device->device, 0);
313 
314 		break;
315 	default:
316 		pr_err("unsupported hid msg type - type %d len %d",
317 		       hid_msg->header.type, hid_msg->header.size);
318 		break;
319 	}
320 
321 }
322 
323 static void mousevsc_on_channel_callback(void *context)
324 {
325 	const int packet_size = 0x100;
326 	int ret;
327 	struct hv_device *device = context;
328 	u32 bytes_recvd;
329 	u64 req_id;
330 	struct vmpacket_descriptor *desc;
331 	unsigned char	*buffer;
332 	int	bufferlen = packet_size;
333 
334 	buffer = kmalloc(bufferlen, GFP_ATOMIC);
335 	if (!buffer)
336 		return;
337 
338 	do {
339 		ret = vmbus_recvpacket_raw(device->channel, buffer,
340 					bufferlen, &bytes_recvd, &req_id);
341 
342 		switch (ret) {
343 		case 0:
344 			if (bytes_recvd <= 0) {
345 				kfree(buffer);
346 				return;
347 			}
348 			desc = (struct vmpacket_descriptor *)buffer;
349 
350 			switch (desc->type) {
351 			case VM_PKT_COMP:
352 				break;
353 
354 			case VM_PKT_DATA_INBAND:
355 				mousevsc_on_receive(device, desc);
356 				break;
357 
358 			default:
359 				pr_err("unhandled packet type %d, tid %llx len %d\n",
360 					desc->type, req_id, bytes_recvd);
361 				break;
362 			}
363 
364 			break;
365 
366 		case -ENOBUFS:
367 			kfree(buffer);
368 			/* Handle large packet */
369 			bufferlen = bytes_recvd;
370 			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
371 
372 			if (!buffer)
373 				return;
374 
375 			break;
376 		}
377 	} while (1);
378 
379 }
380 
381 static int mousevsc_connect_to_vsp(struct hv_device *device)
382 {
383 	int ret = 0;
384 	int t;
385 	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
386 	struct mousevsc_prt_msg *request;
387 	struct mousevsc_prt_msg *response;
388 
389 	request = &input_dev->protocol_req;
390 	memset(request, 0, sizeof(struct mousevsc_prt_msg));
391 
392 	request->type = PIPE_MESSAGE_DATA;
393 	request->size = sizeof(struct synthhid_protocol_request);
394 	request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
395 	request->request.header.size = sizeof(unsigned int);
396 	request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
397 
398 	ret = vmbus_sendpacket(device->channel, request,
399 				sizeof(struct pipe_prt_msg) -
400 				sizeof(unsigned char) +
401 				sizeof(struct synthhid_protocol_request),
402 				(unsigned long)request,
403 				VM_PKT_DATA_INBAND,
404 				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
405 	if (ret)
406 		goto cleanup;
407 
408 	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
409 	if (!t) {
410 		ret = -ETIMEDOUT;
411 		goto cleanup;
412 	}
413 
414 	response = &input_dev->protocol_resp;
415 
416 	if (!response->response.approved) {
417 		pr_err("synthhid protocol request failed (version %d)\n",
418 		       SYNTHHID_INPUT_VERSION);
419 		ret = -ENODEV;
420 		goto cleanup;
421 	}
422 
423 	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
424 	if (!t) {
425 		ret = -ETIMEDOUT;
426 		goto cleanup;
427 	}
428 
429 	/*
430 	 * We should have gotten the device attr, hid desc and report
431 	 * desc at this point
432 	 */
433 	ret = input_dev->dev_info_status;
434 
435 cleanup:
436 	return ret;
437 }
438 
439 static int mousevsc_hid_parse(struct hid_device *hid)
440 {
441 	struct hv_device *dev = hid_get_drvdata(hid);
442 	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
443 
444 	return hid_parse_report(hid, input_dev->report_desc,
445 				input_dev->report_desc_size);
446 }
447 
448 static int mousevsc_hid_open(struct hid_device *hid)
449 {
450 	return 0;
451 }
452 
453 static int mousevsc_hid_start(struct hid_device *hid)
454 {
455 	return 0;
456 }
457 
458 static void mousevsc_hid_close(struct hid_device *hid)
459 {
460 }
461 
462 static void mousevsc_hid_stop(struct hid_device *hid)
463 {
464 }
465 
466 static int mousevsc_hid_raw_request(struct hid_device *hid,
467 				    unsigned char report_num,
468 				    __u8 *buf, size_t len,
469 				    unsigned char rtype,
470 				    int reqtype)
471 {
472 	return 0;
473 }
474 
475 static struct hid_ll_driver mousevsc_ll_driver = {
476 	.parse = mousevsc_hid_parse,
477 	.open = mousevsc_hid_open,
478 	.close = mousevsc_hid_close,
479 	.start = mousevsc_hid_start,
480 	.stop = mousevsc_hid_stop,
481 	.raw_request = mousevsc_hid_raw_request,
482 };
483 
484 static struct hid_driver mousevsc_hid_driver;
485 
486 static int mousevsc_probe(struct hv_device *device,
487 			const struct hv_vmbus_device_id *dev_id)
488 {
489 	int ret;
490 	struct mousevsc_dev *input_dev;
491 	struct hid_device *hid_dev;
492 
493 	input_dev = mousevsc_alloc_device(device);
494 
495 	if (!input_dev)
496 		return -ENOMEM;
497 
498 	ret = vmbus_open(device->channel,
499 		INPUTVSC_SEND_RING_BUFFER_SIZE,
500 		INPUTVSC_RECV_RING_BUFFER_SIZE,
501 		NULL,
502 		0,
503 		mousevsc_on_channel_callback,
504 		device
505 		);
506 
507 	if (ret)
508 		goto probe_err0;
509 
510 	ret = mousevsc_connect_to_vsp(device);
511 
512 	if (ret)
513 		goto probe_err1;
514 
515 	/* workaround SA-167 */
516 	if (input_dev->report_desc[14] == 0x25)
517 		input_dev->report_desc[14] = 0x29;
518 
519 	hid_dev = hid_allocate_device();
520 	if (IS_ERR(hid_dev)) {
521 		ret = PTR_ERR(hid_dev);
522 		goto probe_err1;
523 	}
524 
525 	hid_dev->ll_driver = &mousevsc_ll_driver;
526 	hid_dev->driver = &mousevsc_hid_driver;
527 	hid_dev->bus = BUS_VIRTUAL;
528 	hid_dev->vendor = input_dev->hid_dev_info.vendor;
529 	hid_dev->product = input_dev->hid_dev_info.product;
530 	hid_dev->version = input_dev->hid_dev_info.version;
531 	input_dev->hid_device = hid_dev;
532 
533 	sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
534 
535 	hid_set_drvdata(hid_dev, device);
536 
537 	ret = hid_add_device(hid_dev);
538 	if (ret)
539 		goto probe_err1;
540 
541 
542 	ret = hid_parse(hid_dev);
543 	if (ret) {
544 		hid_err(hid_dev, "parse failed\n");
545 		goto probe_err2;
546 	}
547 
548 	ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
549 
550 	if (ret) {
551 		hid_err(hid_dev, "hw start failed\n");
552 		goto probe_err2;
553 	}
554 
555 	device_init_wakeup(&device->device, true);
556 
557 	input_dev->connected = true;
558 	input_dev->init_complete = true;
559 
560 	return ret;
561 
562 probe_err2:
563 	hid_destroy_device(hid_dev);
564 
565 probe_err1:
566 	vmbus_close(device->channel);
567 
568 probe_err0:
569 	mousevsc_free_device(input_dev);
570 
571 	return ret;
572 }
573 
574 
575 static int mousevsc_remove(struct hv_device *dev)
576 {
577 	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
578 
579 	device_init_wakeup(&dev->device, false);
580 	vmbus_close(dev->channel);
581 	hid_hw_stop(input_dev->hid_device);
582 	hid_destroy_device(input_dev->hid_device);
583 	mousevsc_free_device(input_dev);
584 
585 	return 0;
586 }
587 
588 static const struct hv_vmbus_device_id id_table[] = {
589 	/* Mouse guid */
590 	{ HV_MOUSE_GUID, },
591 	{ },
592 };
593 
594 MODULE_DEVICE_TABLE(vmbus, id_table);
595 
596 static struct  hv_driver mousevsc_drv = {
597 	.name = KBUILD_MODNAME,
598 	.id_table = id_table,
599 	.probe = mousevsc_probe,
600 	.remove = mousevsc_remove,
601 };
602 
603 static int __init mousevsc_init(void)
604 {
605 	return vmbus_driver_register(&mousevsc_drv);
606 }
607 
608 static void __exit mousevsc_exit(void)
609 {
610 	vmbus_driver_unregister(&mousevsc_drv);
611 }
612 
613 MODULE_LICENSE("GPL");
614 module_init(mousevsc_init);
615 module_exit(mousevsc_exit);
616