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aed06b9c S |
1 | /* |
2 | * Copyright (c) 2013, Microsoft Corporation. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms and conditions of the GNU General Public License, | |
6 | * version 2, as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | */ | |
13 | ||
14 | #include <linux/init.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/device.h> | |
17 | #include <linux/completion.h> | |
18 | #include <linux/hyperv.h> | |
19 | #include <linux/serio.h> | |
20 | #include <linux/slab.h> | |
21 | ||
22 | /* | |
23 | * Current version 1.0 | |
24 | * | |
25 | */ | |
26 | #define SYNTH_KBD_VERSION_MAJOR 1 | |
27 | #define SYNTH_KBD_VERSION_MINOR 0 | |
28 | #define SYNTH_KBD_VERSION (SYNTH_KBD_VERSION_MINOR | \ | |
29 | (SYNTH_KBD_VERSION_MAJOR << 16)) | |
30 | ||
31 | ||
32 | /* | |
33 | * Message types in the synthetic input protocol | |
34 | */ | |
35 | enum synth_kbd_msg_type { | |
36 | SYNTH_KBD_PROTOCOL_REQUEST = 1, | |
37 | SYNTH_KBD_PROTOCOL_RESPONSE = 2, | |
38 | SYNTH_KBD_EVENT = 3, | |
39 | SYNTH_KBD_LED_INDICATORS = 4, | |
40 | }; | |
41 | ||
42 | /* | |
43 | * Basic message structures. | |
44 | */ | |
45 | struct synth_kbd_msg_hdr { | |
46 | __le32 type; | |
47 | }; | |
48 | ||
49 | struct synth_kbd_msg { | |
50 | struct synth_kbd_msg_hdr header; | |
51 | char data[]; /* Enclosed message */ | |
52 | }; | |
53 | ||
54 | union synth_kbd_version { | |
55 | __le32 version; | |
56 | }; | |
57 | ||
58 | /* | |
59 | * Protocol messages | |
60 | */ | |
61 | struct synth_kbd_protocol_request { | |
62 | struct synth_kbd_msg_hdr header; | |
63 | union synth_kbd_version version_requested; | |
64 | }; | |
65 | ||
66 | #define PROTOCOL_ACCEPTED BIT(0) | |
67 | struct synth_kbd_protocol_response { | |
68 | struct synth_kbd_msg_hdr header; | |
69 | __le32 proto_status; | |
70 | }; | |
71 | ||
72 | #define IS_UNICODE BIT(0) | |
73 | #define IS_BREAK BIT(1) | |
74 | #define IS_E0 BIT(2) | |
75 | #define IS_E1 BIT(3) | |
76 | struct synth_kbd_keystroke { | |
77 | struct synth_kbd_msg_hdr header; | |
78 | __le16 make_code; | |
79 | __le16 reserved0; | |
80 | __le32 info; /* Additional information */ | |
81 | }; | |
82 | ||
83 | ||
84 | #define HK_MAXIMUM_MESSAGE_SIZE 256 | |
85 | ||
86 | #define KBD_VSC_SEND_RING_BUFFER_SIZE (10 * PAGE_SIZE) | |
87 | #define KBD_VSC_RECV_RING_BUFFER_SIZE (10 * PAGE_SIZE) | |
88 | ||
89 | #define XTKBD_EMUL0 0xe0 | |
90 | #define XTKBD_EMUL1 0xe1 | |
91 | #define XTKBD_RELEASE 0x80 | |
92 | ||
93 | ||
94 | /* | |
95 | * Represents a keyboard device | |
96 | */ | |
97 | struct hv_kbd_dev { | |
98 | struct hv_device *hv_dev; | |
99 | struct serio *hv_serio; | |
100 | struct synth_kbd_protocol_request protocol_req; | |
101 | struct synth_kbd_protocol_response protocol_resp; | |
102 | /* Synchronize the request/response if needed */ | |
103 | struct completion wait_event; | |
104 | spinlock_t lock; /* protects 'started' field */ | |
105 | bool started; | |
106 | }; | |
107 | ||
108 | static void hv_kbd_on_receive(struct hv_device *hv_dev, | |
109 | struct synth_kbd_msg *msg, u32 msg_length) | |
110 | { | |
111 | struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev); | |
112 | struct synth_kbd_keystroke *ks_msg; | |
113 | unsigned long flags; | |
114 | u32 msg_type = __le32_to_cpu(msg->header.type); | |
115 | u32 info; | |
116 | u16 scan_code; | |
117 | ||
118 | switch (msg_type) { | |
119 | case SYNTH_KBD_PROTOCOL_RESPONSE: | |
120 | /* | |
121 | * Validate the information provided by the host. | |
122 | * If the host is giving us a bogus packet, | |
123 | * drop the packet (hoping the problem | |
124 | * goes away). | |
125 | */ | |
126 | if (msg_length < sizeof(struct synth_kbd_protocol_response)) { | |
127 | dev_err(&hv_dev->device, | |
128 | "Illegal protocol response packet (len: %d)\n", | |
129 | msg_length); | |
130 | break; | |
131 | } | |
132 | ||
133 | memcpy(&kbd_dev->protocol_resp, msg, | |
134 | sizeof(struct synth_kbd_protocol_response)); | |
135 | complete(&kbd_dev->wait_event); | |
136 | break; | |
137 | ||
138 | case SYNTH_KBD_EVENT: | |
139 | /* | |
140 | * Validate the information provided by the host. | |
141 | * If the host is giving us a bogus packet, | |
142 | * drop the packet (hoping the problem | |
143 | * goes away). | |
144 | */ | |
145 | if (msg_length < sizeof(struct synth_kbd_keystroke)) { | |
146 | dev_err(&hv_dev->device, | |
147 | "Illegal keyboard event packet (len: %d)\n", | |
148 | msg_length); | |
149 | break; | |
150 | } | |
151 | ||
152 | ks_msg = (struct synth_kbd_keystroke *)msg; | |
153 | info = __le32_to_cpu(ks_msg->info); | |
154 | ||
155 | /* | |
156 | * Inject the information through the serio interrupt. | |
157 | */ | |
158 | spin_lock_irqsave(&kbd_dev->lock, flags); | |
159 | if (kbd_dev->started) { | |
160 | if (info & IS_E0) | |
161 | serio_interrupt(kbd_dev->hv_serio, | |
162 | XTKBD_EMUL0, 0); | |
163 | ||
164 | scan_code = __le16_to_cpu(ks_msg->make_code); | |
165 | if (info & IS_BREAK) | |
166 | scan_code |= XTKBD_RELEASE; | |
167 | ||
168 | serio_interrupt(kbd_dev->hv_serio, scan_code, 0); | |
169 | } | |
170 | spin_unlock_irqrestore(&kbd_dev->lock, flags); | |
171 | break; | |
172 | ||
173 | default: | |
174 | dev_err(&hv_dev->device, | |
175 | "unhandled message type %d\n", msg_type); | |
176 | } | |
177 | } | |
178 | ||
179 | static void hv_kbd_handle_received_packet(struct hv_device *hv_dev, | |
180 | struct vmpacket_descriptor *desc, | |
181 | u32 bytes_recvd, | |
182 | u64 req_id) | |
183 | { | |
184 | struct synth_kbd_msg *msg; | |
185 | u32 msg_sz; | |
186 | ||
187 | switch (desc->type) { | |
188 | case VM_PKT_COMP: | |
189 | break; | |
190 | ||
191 | case VM_PKT_DATA_INBAND: | |
192 | /* | |
193 | * We have a packet that has "inband" data. The API used | |
194 | * for retrieving the packet guarantees that the complete | |
195 | * packet is read. So, minimally, we should be able to | |
196 | * parse the payload header safely (assuming that the host | |
197 | * can be trusted. Trusting the host seems to be a | |
198 | * reasonable assumption because in a virtualized | |
199 | * environment there is not whole lot you can do if you | |
200 | * don't trust the host. | |
201 | * | |
202 | * Nonetheless, let us validate if the host can be trusted | |
203 | * (in a trivial way). The interesting aspect of this | |
204 | * validation is how do you recover if we discover that the | |
205 | * host is not to be trusted? Simply dropping the packet, I | |
206 | * don't think is an appropriate recovery. In the interest | |
207 | * of failing fast, it may be better to crash the guest. | |
208 | * For now, I will just drop the packet! | |
209 | */ | |
210 | ||
211 | msg_sz = bytes_recvd - (desc->offset8 << 3); | |
212 | if (msg_sz <= sizeof(struct synth_kbd_msg_hdr)) { | |
213 | /* | |
214 | * Drop the packet and hope | |
215 | * the problem magically goes away. | |
216 | */ | |
217 | dev_err(&hv_dev->device, | |
218 | "Illegal packet (type: %d, tid: %llx, size: %d)\n", | |
219 | desc->type, req_id, msg_sz); | |
220 | break; | |
221 | } | |
222 | ||
223 | msg = (void *)desc + (desc->offset8 << 3); | |
224 | hv_kbd_on_receive(hv_dev, msg, msg_sz); | |
225 | break; | |
226 | ||
227 | default: | |
228 | dev_err(&hv_dev->device, | |
229 | "unhandled packet type %d, tid %llx len %d\n", | |
230 | desc->type, req_id, bytes_recvd); | |
231 | break; | |
232 | } | |
233 | } | |
234 | ||
235 | static void hv_kbd_on_channel_callback(void *context) | |
236 | { | |
237 | struct hv_device *hv_dev = context; | |
238 | void *buffer; | |
239 | int bufferlen = 0x100; /* Start with sensible size */ | |
240 | u32 bytes_recvd; | |
241 | u64 req_id; | |
242 | int error; | |
243 | ||
244 | buffer = kmalloc(bufferlen, GFP_ATOMIC); | |
245 | if (!buffer) | |
246 | return; | |
247 | ||
248 | while (1) { | |
249 | error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen, | |
250 | &bytes_recvd, &req_id); | |
251 | switch (error) { | |
252 | case 0: | |
253 | if (bytes_recvd == 0) { | |
254 | kfree(buffer); | |
255 | return; | |
256 | } | |
257 | ||
258 | hv_kbd_handle_received_packet(hv_dev, buffer, | |
259 | bytes_recvd, req_id); | |
260 | break; | |
261 | ||
262 | case -ENOBUFS: | |
263 | kfree(buffer); | |
264 | /* Handle large packet */ | |
265 | bufferlen = bytes_recvd; | |
266 | buffer = kmalloc(bytes_recvd, GFP_ATOMIC); | |
267 | if (!buffer) | |
268 | return; | |
269 | break; | |
270 | } | |
271 | } | |
272 | } | |
273 | ||
274 | static int hv_kbd_connect_to_vsp(struct hv_device *hv_dev) | |
275 | { | |
276 | struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev); | |
277 | struct synth_kbd_protocol_request *request; | |
278 | struct synth_kbd_protocol_response *response; | |
279 | u32 proto_status; | |
280 | int error; | |
281 | ||
282 | request = &kbd_dev->protocol_req; | |
283 | memset(request, 0, sizeof(struct synth_kbd_protocol_request)); | |
284 | request->header.type = __cpu_to_le32(SYNTH_KBD_PROTOCOL_REQUEST); | |
285 | request->version_requested.version = __cpu_to_le32(SYNTH_KBD_VERSION); | |
286 | ||
287 | error = vmbus_sendpacket(hv_dev->channel, request, | |
288 | sizeof(struct synth_kbd_protocol_request), | |
289 | (unsigned long)request, | |
290 | VM_PKT_DATA_INBAND, | |
291 | VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); | |
292 | if (error) | |
293 | return error; | |
294 | ||
295 | if (!wait_for_completion_timeout(&kbd_dev->wait_event, 10 * HZ)) | |
296 | return -ETIMEDOUT; | |
297 | ||
298 | response = &kbd_dev->protocol_resp; | |
299 | proto_status = __le32_to_cpu(response->proto_status); | |
300 | if (!(proto_status & PROTOCOL_ACCEPTED)) { | |
301 | dev_err(&hv_dev->device, | |
302 | "synth_kbd protocol request failed (version %d)\n", | |
303 | SYNTH_KBD_VERSION); | |
304 | return -ENODEV; | |
305 | } | |
306 | ||
307 | return 0; | |
308 | } | |
309 | ||
310 | static int hv_kbd_start(struct serio *serio) | |
311 | { | |
312 | struct hv_kbd_dev *kbd_dev = serio->port_data; | |
313 | unsigned long flags; | |
314 | ||
315 | spin_lock_irqsave(&kbd_dev->lock, flags); | |
316 | kbd_dev->started = true; | |
317 | spin_unlock_irqrestore(&kbd_dev->lock, flags); | |
318 | ||
319 | return 0; | |
320 | } | |
321 | ||
322 | static void hv_kbd_stop(struct serio *serio) | |
323 | { | |
324 | struct hv_kbd_dev *kbd_dev = serio->port_data; | |
325 | unsigned long flags; | |
326 | ||
327 | spin_lock_irqsave(&kbd_dev->lock, flags); | |
328 | kbd_dev->started = false; | |
329 | spin_unlock_irqrestore(&kbd_dev->lock, flags); | |
330 | } | |
331 | ||
332 | static int hv_kbd_probe(struct hv_device *hv_dev, | |
333 | const struct hv_vmbus_device_id *dev_id) | |
334 | { | |
335 | struct hv_kbd_dev *kbd_dev; | |
336 | struct serio *hv_serio; | |
337 | int error; | |
338 | ||
339 | kbd_dev = kzalloc(sizeof(struct hv_kbd_dev), GFP_KERNEL); | |
340 | hv_serio = kzalloc(sizeof(struct serio), GFP_KERNEL); | |
341 | if (!kbd_dev || !hv_serio) { | |
342 | error = -ENOMEM; | |
343 | goto err_free_mem; | |
344 | } | |
345 | ||
346 | kbd_dev->hv_dev = hv_dev; | |
347 | kbd_dev->hv_serio = hv_serio; | |
348 | spin_lock_init(&kbd_dev->lock); | |
349 | init_completion(&kbd_dev->wait_event); | |
350 | hv_set_drvdata(hv_dev, kbd_dev); | |
351 | ||
352 | hv_serio->dev.parent = &hv_dev->device; | |
353 | hv_serio->id.type = SERIO_8042_XL; | |
354 | hv_serio->port_data = kbd_dev; | |
355 | strlcpy(hv_serio->name, dev_name(&hv_dev->device), | |
356 | sizeof(hv_serio->name)); | |
357 | strlcpy(hv_serio->phys, dev_name(&hv_dev->device), | |
358 | sizeof(hv_serio->phys)); | |
359 | ||
360 | hv_serio->start = hv_kbd_start; | |
361 | hv_serio->stop = hv_kbd_stop; | |
362 | ||
363 | error = vmbus_open(hv_dev->channel, | |
364 | KBD_VSC_SEND_RING_BUFFER_SIZE, | |
365 | KBD_VSC_RECV_RING_BUFFER_SIZE, | |
366 | NULL, 0, | |
367 | hv_kbd_on_channel_callback, | |
368 | hv_dev); | |
369 | if (error) | |
370 | goto err_free_mem; | |
371 | ||
372 | error = hv_kbd_connect_to_vsp(hv_dev); | |
373 | if (error) | |
374 | goto err_close_vmbus; | |
375 | ||
376 | serio_register_port(kbd_dev->hv_serio); | |
377 | return 0; | |
378 | ||
379 | err_close_vmbus: | |
380 | vmbus_close(hv_dev->channel); | |
381 | err_free_mem: | |
382 | kfree(hv_serio); | |
383 | kfree(kbd_dev); | |
384 | return error; | |
385 | } | |
386 | ||
387 | static int hv_kbd_remove(struct hv_device *hv_dev) | |
388 | { | |
389 | struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev); | |
390 | ||
391 | serio_unregister_port(kbd_dev->hv_serio); | |
392 | vmbus_close(hv_dev->channel); | |
393 | kfree(kbd_dev); | |
394 | ||
395 | hv_set_drvdata(hv_dev, NULL); | |
396 | ||
397 | return 0; | |
398 | } | |
399 | ||
400 | /* | |
401 | * Keyboard GUID | |
402 | * {f912ad6d-2b17-48ea-bd65-f927a61c7684} | |
403 | */ | |
404 | #define HV_KBD_GUID \ | |
405 | .guid = { \ | |
406 | 0x6d, 0xad, 0x12, 0xf9, 0x17, 0x2b, 0xea, 0x48, \ | |
407 | 0xbd, 0x65, 0xf9, 0x27, 0xa6, 0x1c, 0x76, 0x84 \ | |
408 | } | |
409 | ||
410 | static const struct hv_vmbus_device_id id_table[] = { | |
411 | /* Keyboard guid */ | |
412 | { HV_KBD_GUID, }, | |
413 | { }, | |
414 | }; | |
415 | ||
416 | MODULE_DEVICE_TABLE(vmbus, id_table); | |
417 | ||
418 | static struct hv_driver hv_kbd_drv = { | |
419 | .name = KBUILD_MODNAME, | |
420 | .id_table = id_table, | |
421 | .probe = hv_kbd_probe, | |
422 | .remove = hv_kbd_remove, | |
423 | }; | |
424 | ||
425 | static int __init hv_kbd_init(void) | |
426 | { | |
427 | return vmbus_driver_register(&hv_kbd_drv); | |
428 | } | |
429 | ||
430 | static void __exit hv_kbd_exit(void) | |
431 | { | |
432 | vmbus_driver_unregister(&hv_kbd_drv); | |
433 | } | |
434 | ||
435 | MODULE_LICENSE("GPL"); | |
436 | module_init(hv_kbd_init); | |
437 | module_exit(hv_kbd_exit); |