summaryrefslogtreecommitdiffstats
path: root/include/xen/interface/io/kbdif.h
blob: b4439cf48220a731ae3a8e0b2ffa1f0939ee00fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
/*
 * kbdif.h -- Xen virtual keyboard/mouse
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
 * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
 */

#ifndef __XEN_PUBLIC_IO_KBDIF_H__
#define __XEN_PUBLIC_IO_KBDIF_H__

/*
 *****************************************************************************
 *                     Feature and Parameter Negotiation
 *****************************************************************************
 *
 * The two halves of a para-virtual driver utilize nodes within
 * XenStore to communicate capabilities and to negotiate operating parameters.
 * This section enumerates these nodes which reside in the respective front and
 * backend portions of XenStore, following XenBus convention.
 *
 * All data in XenStore is stored as strings.  Nodes specifying numeric
 * values are encoded in decimal. Integer value ranges listed below are
 * expressed as fixed sized integer types capable of storing the conversion
 * of a properly formated node string, without loss of information.
 *
 *****************************************************************************
 *                            Backend XenBus Nodes
 *****************************************************************************
 *
 *---------------------------- Features supported ----------------------------
 *
 * Capable backend advertises supported features by publishing
 * corresponding entries in XenStore and puts 1 as the value of the entry.
 * If a feature is not supported then 0 must be set or feature entry omitted.
 *
 * feature-disable-keyboard
 *      Values:         <uint>
 *
 *      If there is no need to expose a virtual keyboard device by the
 *      frontend then this must be set to 1.
 *
 * feature-disable-pointer
 *      Values:         <uint>
 *
 *      If there is no need to expose a virtual pointer device by the
 *      frontend then this must be set to 1.
 *
 * feature-abs-pointer
 *      Values:         <uint>
 *
 *      Backends, which support reporting of absolute coordinates for pointer
 *      device should set this to 1.
 *
 * feature-multi-touch
 *      Values:         <uint>
 *
 *      Backends, which support reporting of multi-touch events
 *      should set this to 1.
 *
 * feature-raw-pointer
 *      Values:        <uint>
 *
 *      Backends, which support reporting raw (unscaled) absolute coordinates
 *      for pointer devices should set this to 1. Raw (unscaled) values have
 *      a range of [0, 0x7fff].
 *
 *-----------------------  Device Instance Parameters ------------------------
 *
 * unique-id
 *      Values:         <string>
 *
 *      After device instance initialization it is assigned a unique ID,
 *      so every instance of the frontend can be identified by the backend
 *      by this ID. This can be UUID or such.
 *
 *------------------------- Pointer Device Parameters ------------------------
 *
 * width
 *      Values:         <uint>
 *
 *      Maximum X coordinate (width) to be used by the frontend
 *      while reporting input events, pixels, [0; UINT32_MAX].
 *
 * height
 *      Values:         <uint>
 *
 *      Maximum Y coordinate (height) to be used by the frontend
 *      while reporting input events, pixels, [0; UINT32_MAX].
 *
 *----------------------- Multi-touch Device Parameters ----------------------
 *
 * multi-touch-num-contacts
 *      Values:         <uint>
 *
 *      Number of simultaneous touches reported.
 *
 * multi-touch-width
 *      Values:         <uint>
 *
 *      Width of the touch area to be used by the frontend
 *      while reporting input events, pixels, [0; UINT32_MAX].
 *
 * multi-touch-height
 *      Values:         <uint>
 *
 *      Height of the touch area to be used by the frontend
 *      while reporting input events, pixels, [0; UINT32_MAX].
 *
 *****************************************************************************
 *                            Frontend XenBus Nodes
 *****************************************************************************
 *
 *------------------------------ Feature request -----------------------------
 *
 * Capable frontend requests features from backend via setting corresponding
 * entries to 1 in XenStore. Requests for features not advertised as supported
 * by the backend have no effect.
 *
 * request-abs-pointer
 *      Values:         <uint>
 *
 *      Request backend to report absolute pointer coordinates
 *      (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
 *
 * request-multi-touch
 *      Values:         <uint>
 *
 *      Request backend to report multi-touch events.
 *
 * request-raw-pointer
 *      Values:         <uint>
 *
 *      Request backend to report raw unscaled absolute pointer coordinates.
 *      This option is only valid if request-abs-pointer is also set.
 *      Raw unscaled coordinates have the range [0, 0x7fff]
 *
 *----------------------- Request Transport Parameters -----------------------
 *
 * event-channel
 *      Values:         <uint>
 *
 *      The identifier of the Xen event channel used to signal activity
 *      in the ring buffer.
 *
 * page-gref
 *      Values:         <uint>
 *
 *      The Xen grant reference granting permission for the backend to map
 *      a sole page in a single page sized event ring buffer.
 *
 * page-ref
 *      Values:         <uint>
 *
 *      OBSOLETE, not recommended for use.
 *      PFN of the shared page.
 */

/*
 * EVENT CODES.
 */

#define XENKBD_TYPE_MOTION		1
#define XENKBD_TYPE_RESERVED		2
#define XENKBD_TYPE_KEY			3
#define XENKBD_TYPE_POS			4
#define XENKBD_TYPE_MTOUCH		5

/* Multi-touch event sub-codes */

#define XENKBD_MT_EV_DOWN		0
#define XENKBD_MT_EV_UP			1
#define XENKBD_MT_EV_MOTION		2
#define XENKBD_MT_EV_SYN		3
#define XENKBD_MT_EV_SHAPE		4
#define XENKBD_MT_EV_ORIENT		5

/*
 * CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
 */

#define XENKBD_DRIVER_NAME		"vkbd"

#define XENKBD_FIELD_FEAT_DSBL_KEYBRD	"feature-disable-keyboard"
#define XENKBD_FIELD_FEAT_DSBL_POINTER	"feature-disable-pointer"
#define XENKBD_FIELD_FEAT_ABS_POINTER	"feature-abs-pointer"
#define XENKBD_FIELD_FEAT_RAW_POINTER	"feature-raw-pointer"
#define XENKBD_FIELD_FEAT_MTOUCH	"feature-multi-touch"
#define XENKBD_FIELD_REQ_ABS_POINTER	"request-abs-pointer"
#define XENKBD_FIELD_REQ_RAW_POINTER	"request-raw-pointer"
#define XENKBD_FIELD_REQ_MTOUCH		"request-multi-touch"
#define XENKBD_FIELD_RING_GREF		"page-gref"
#define XENKBD_FIELD_EVT_CHANNEL	"event-channel"
#define XENKBD_FIELD_WIDTH		"width"
#define XENKBD_FIELD_HEIGHT		"height"
#define XENKBD_FIELD_MT_WIDTH		"multi-touch-width"
#define XENKBD_FIELD_MT_HEIGHT		"multi-touch-height"
#define XENKBD_FIELD_MT_NUM_CONTACTS	"multi-touch-num-contacts"
#define XENKBD_FIELD_UNIQUE_ID		"unique-id"

/* OBSOLETE, not recommended for use */
#define XENKBD_FIELD_RING_REF		"page-ref"

/*
 *****************************************************************************
 * Description of the protocol between frontend and backend driver.
 *****************************************************************************
 *
 * The two halves of a Para-virtual driver communicate with
 * each other using a shared page and an event channel.
 * Shared page contains a ring with event structures.
 *
 * All reserved fields in the structures below must be 0.
 *
 *****************************************************************************
 *                           Backend to frontend events
 *****************************************************************************
 *
 * Frontends should ignore unknown in events.
 * All event packets have the same length (40 octets)
 * All event packets have common header:
 *
 *          0         octet
 * +-----------------+
 * |       type      |
 * +-----------------+
 * type - uint8_t, event code, XENKBD_TYPE_???
 *
 *
 * Pointer relative movement event
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MOTION  |                     reserved                     | 4
 * +----------------+----------------+----------------+----------------+
 * |                               rel_x                               | 8
 * +----------------+----------------+----------------+----------------+
 * |                               rel_y                               | 12
 * +----------------+----------------+----------------+----------------+
 * |                               rel_z                               | 16
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 20
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * rel_x - int32_t, relative X motion
 * rel_y - int32_t, relative Y motion
 * rel_z - int32_t, relative Z motion (wheel)
 */

struct xenkbd_motion {
	uint8_t type;
	int32_t rel_x;
	int32_t rel_y;
	int32_t rel_z;
};

/*
 * Key event (includes pointer buttons)
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_KEY     |     pressed    |            reserved             | 4
 * +----------------+----------------+----------------+----------------+
 * |                              keycode                              | 8
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 12
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * pressed - uint8_t, 1 if pressed; 0 otherwise
 * keycode - uint32_t, KEY_* from linux/input.h
 */

struct xenkbd_key {
	uint8_t type;
	uint8_t pressed;
	uint32_t keycode;
};

/*
 * Pointer absolute position event
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_POS     |                     reserved                     | 4
 * +----------------+----------------+----------------+----------------+
 * |                               abs_x                               | 8
 * +----------------+----------------+----------------+----------------+
 * |                               abs_y                               | 12
 * +----------------+----------------+----------------+----------------+
 * |                               rel_z                               | 16
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 20
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * abs_x - int32_t, absolute X position (in FB pixels)
 * abs_y - int32_t, absolute Y position (in FB pixels)
 * rel_z - int32_t, relative Z motion (wheel)
 */

struct xenkbd_position {
	uint8_t type;
	int32_t abs_x;
	int32_t abs_y;
	int32_t rel_z;
};

/*
 * Multi-touch event and its sub-types
 *
 * All multi-touch event packets have common header:
 *
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MTOUCH  |   event_type   |   contact_id   |    reserved    | 4
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 8
 * +----------------+----------------+----------------+----------------+
 *
 * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
 * contact_id - unt8_t, ID of the contact
 *
 * Touch interactions can consist of one or more contacts.
 * For each contact, a series of events is generated, starting
 * with a down event, followed by zero or more motion events,
 * and ending with an up event. Events relating to the same
 * contact point can be identified by the ID of the sequence: contact ID.
 * Contact ID may be reused after XENKBD_MT_EV_UP event and
 * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
 *
 * For further information please refer to documentation on Wayland [1],
 * Linux [2] and Windows [3] multi-touch support.
 *
 * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
 * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
 * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
 *
 *
 * Multi-touch down event - sent when a new touch is made: touch is assigned
 * a unique contact ID, sent with this and consequent events related
 * to this touch.
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MTOUCH  |   _MT_EV_DOWN  |   contact_id   |    reserved    | 4
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 8
 * +----------------+----------------+----------------+----------------+
 * |                               abs_x                               | 12
 * +----------------+----------------+----------------+----------------+
 * |                               abs_y                               | 16
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 20
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * abs_x - int32_t, absolute X position, in pixels
 * abs_y - int32_t, absolute Y position, in pixels
 *
 * Multi-touch contact release event
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MTOUCH  |  _MT_EV_UP     |   contact_id   |    reserved    | 4
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 8
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * Multi-touch motion event
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MTOUCH  |  _MT_EV_MOTION |   contact_id   |    reserved    | 4
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 8
 * +----------------+----------------+----------------+----------------+
 * |                               abs_x                               | 12
 * +----------------+----------------+----------------+----------------+
 * |                               abs_y                               | 16
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 20
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * abs_x - int32_t, absolute X position, in pixels,
 * abs_y - int32_t, absolute Y position, in pixels,
 *
 * Multi-touch input synchronization event - shows end of a set of events
 * which logically belong together.
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MTOUCH  |  _MT_EV_SYN    |   contact_id   |    reserved    | 4
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 8
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * Multi-touch shape event - touch point's shape has changed its shape.
 * Shape is approximated by an ellipse through the major and minor axis
 * lengths: major is the longer diameter of the ellipse and minor is the
 * shorter one. Center of the ellipse is reported via
 * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MTOUCH  |  _MT_EV_SHAPE  |   contact_id   |    reserved    | 4
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 8
 * +----------------+----------------+----------------+----------------+
 * |                               major                               | 12
 * +----------------+----------------+----------------+----------------+
 * |                               minor                               | 16
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 20
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * major - unt32_t, length of the major axis, pixels
 * minor - unt32_t, length of the minor axis, pixels
 *
 * Multi-touch orientation event - touch point's shape has changed
 * its orientation: calculated as a clockwise angle between the major axis
 * of the ellipse and positive Y axis in degrees, [-180; +180].
 *         0                1                 2               3        octet
 * +----------------+----------------+----------------+----------------+
 * |  _TYPE_MTOUCH  |  _MT_EV_ORIENT |   contact_id   |    reserved    | 4
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 8
 * +----------------+----------------+----------------+----------------+
 * |           orientation           |            reserved             | 12
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 16
 * +----------------+----------------+----------------+----------------+
 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 * +----------------+----------------+----------------+----------------+
 * |                             reserved                              | 40
 * +----------------+----------------+----------------+----------------+
 *
 * orientation - int16_t, clockwise angle of the major axis
 */

struct xenkbd_mtouch {
	uint8_t type;			/* XENKBD_TYPE_MTOUCH */
	uint8_t event_type;		/* XENKBD_MT_EV_??? */
	uint8_t contact_id;
	uint8_t reserved[5];		/* reserved for the future use */
	union {
		struct {
			int32_t abs_x;	/* absolute X position, pixels */
			int32_t abs_y;	/* absolute Y position, pixels */
		} pos;
		struct {
			uint32_t major;	/* length of the major axis, pixels */
			uint32_t minor;	/* length of the minor axis, pixels */
		} shape;
		int16_t orientation;	/* clockwise angle of the major axis */
	} u;
};

#define XENKBD_IN_EVENT_SIZE 40

union xenkbd_in_event {
	uint8_t type;
	struct xenkbd_motion motion;
	struct xenkbd_key key;
	struct xenkbd_position pos;
	struct xenkbd_mtouch mtouch;
	char pad[XENKBD_IN_EVENT_SIZE];
};

/*
 *****************************************************************************
 *                            Frontend to backend events
 *****************************************************************************
 *
 * Out events may be sent only when requested by backend, and receipt
 * of an unknown out event is an error.
 * No out events currently defined.

 * All event packets have the same length (40 octets)
 * All event packets have common header:
 *          0         octet
 * +-----------------+
 * |       type      |
 * +-----------------+
 * type - uint8_t, event code
 */

#define XENKBD_OUT_EVENT_SIZE 40

union xenkbd_out_event {
	uint8_t type;
	char pad[XENKBD_OUT_EVENT_SIZE];
};

/*
 *****************************************************************************
 *                            Shared page
 *****************************************************************************
 */

#define XENKBD_IN_RING_SIZE 2048
#define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
#define XENKBD_IN_RING_OFFS 1024
#define XENKBD_IN_RING(page) \
	((union xenkbd_in_event *)((char *)(page) + XENKBD_IN_RING_OFFS))
#define XENKBD_IN_RING_REF(page, idx) \
	(XENKBD_IN_RING((page))[(idx) % XENKBD_IN_RING_LEN])

#define XENKBD_OUT_RING_SIZE 1024
#define XENKBD_OUT_RING_LEN (XENKBD_OUT_RING_SIZE / XENKBD_OUT_EVENT_SIZE)
#define XENKBD_OUT_RING_OFFS (XENKBD_IN_RING_OFFS + XENKBD_IN_RING_SIZE)
#define XENKBD_OUT_RING(page) \
	((union xenkbd_out_event *)((char *)(page) + XENKBD_OUT_RING_OFFS))
#define XENKBD_OUT_RING_REF(page, idx) \
	(XENKBD_OUT_RING((page))[(idx) % XENKBD_OUT_RING_LEN])

struct xenkbd_page {
	uint32_t in_cons, in_prod;
	uint32_t out_cons, out_prod;
};

#endif /* __XEN_PUBLIC_IO_KBDIF_H__ */