1/*
2 * Driver for Virtual PS/2 Mouse on VMware and QEMU hypervisors.
3 *
4 * Copyright (C) 2014, VMware, Inc. All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * Twin device code is hugely inspired by the ALPS driver.
11 * Authors:
12 * Dmitry Torokhov <dmitry.torokhov@gmail.com>
13 * Thomas Hellstrom <thellstrom@vmware.com>
14 */
15
16#include <linux/input.h>
17#include <linux/serio.h>
18#include <linux/libps2.h>
19#include <linux/slab.h>
20#include <linux/module.h>
21#include <asm/hypervisor.h>
22
23#include "psmouse.h"
24#include "vmmouse.h"
25
26#define VMMOUSE_PROTO_MAGIC 0x564D5868U
27#define VMMOUSE_PROTO_PORT 0x5658
28
29/*
30 * Main commands supported by the vmmouse hypervisor port.
31 */
32#define VMMOUSE_PROTO_CMD_GETVERSION 10
33#define VMMOUSE_PROTO_CMD_ABSPOINTER_DATA 39
34#define VMMOUSE_PROTO_CMD_ABSPOINTER_STATUS 40
35#define VMMOUSE_PROTO_CMD_ABSPOINTER_COMMAND 41
36#define VMMOUSE_PROTO_CMD_ABSPOINTER_RESTRICT 86
37
38/*
39 * Subcommands for VMMOUSE_PROTO_CMD_ABSPOINTER_COMMAND
40 */
41#define VMMOUSE_CMD_ENABLE 0x45414552U
42#define VMMOUSE_CMD_DISABLE 0x000000f5U
43#define VMMOUSE_CMD_REQUEST_RELATIVE 0x4c455252U
44#define VMMOUSE_CMD_REQUEST_ABSOLUTE 0x53424152U
45
46#define VMMOUSE_ERROR 0xffff0000U
47
48#define VMMOUSE_VERSION_ID 0x3442554aU
49
50#define VMMOUSE_RELATIVE_PACKET 0x00010000U
51
52#define VMMOUSE_LEFT_BUTTON 0x20
53#define VMMOUSE_RIGHT_BUTTON 0x10
54#define VMMOUSE_MIDDLE_BUTTON 0x08
55
56/*
57 * VMMouse Restrict command
58 */
59#define VMMOUSE_RESTRICT_ANY 0x00
60#define VMMOUSE_RESTRICT_CPL0 0x01
61#define VMMOUSE_RESTRICT_IOPL 0x02
62
63#define VMMOUSE_MAX_X 0xFFFF
64#define VMMOUSE_MAX_Y 0xFFFF
65
66#define VMMOUSE_VENDOR "VMware"
67#define VMMOUSE_NAME "VMMouse"
68
69/**
70 * struct vmmouse_data - private data structure for the vmmouse driver
71 *
72 * @abs_dev: "Absolute" device used to report absolute mouse movement.
73 * @phys: Physical path for the absolute device.
74 * @dev_name: Name attribute name for the absolute device.
75 */
76struct vmmouse_data {
77 struct input_dev *abs_dev;
78 char phys[32];
79 char dev_name[128];
80};
81
82/**
83 * Hypervisor-specific bi-directional communication channel
84 * implementing the vmmouse protocol. Should never execute on
85 * bare metal hardware.
86 */
87#define VMMOUSE_CMD(cmd, in1, out1, out2, out3, out4) \
88({ \
89 unsigned long __dummy1, __dummy2; \
90 __asm__ __volatile__ ("inl %%dx" : \
91 "=a"(out1), \
92 "=b"(out2), \
93 "=c"(out3), \
94 "=d"(out4), \
95 "=S"(__dummy1), \
96 "=D"(__dummy2) : \
97 "a"(VMMOUSE_PROTO_MAGIC), \
98 "b"(in1), \
99 "c"(VMMOUSE_PROTO_CMD_##cmd), \
100 "d"(VMMOUSE_PROTO_PORT) : \
101 "memory"); \
102})
103
104/**
105 * vmmouse_report_button - report button state on the correct input device
106 *
107 * @psmouse: Pointer to the psmouse struct
108 * @abs_dev: The absolute input device
109 * @rel_dev: The relative input device
110 * @pref_dev: The preferred device for reporting
111 * @code: Button code
112 * @value: Button value
113 *
114 * Report @value and @code on @pref_dev, unless the button is already
115 * pressed on the other device, in which case the state is reported on that
116 * device.
117 */
118static void vmmouse_report_button(struct psmouse *psmouse,
119 struct input_dev *abs_dev,
120 struct input_dev *rel_dev,
121 struct input_dev *pref_dev,
122 unsigned int code, int value)
123{
124 if (test_bit(code, abs_dev->key))
125 pref_dev = abs_dev;
126 else if (test_bit(code, rel_dev->key))
127 pref_dev = rel_dev;
128
129 input_report_key(pref_dev, code, value);
130}
131
132/**
133 * vmmouse_report_events - process events on the vmmouse communications channel
134 *
135 * @psmouse: Pointer to the psmouse struct
136 *
137 * This function pulls events from the vmmouse communications channel and
138 * reports them on the correct (absolute or relative) input device. When the
139 * communications channel is drained, or if we've processed more than 255
140 * psmouse commands, the function returns PSMOUSE_FULL_PACKET. If there is a
141 * host- or synchronization error, the function returns PSMOUSE_BAD_DATA in
142 * the hope that the caller will reset the communications channel.
143 */
144static psmouse_ret_t vmmouse_report_events(struct psmouse *psmouse)
145{
146 struct input_dev *rel_dev = psmouse->dev;
147 struct vmmouse_data *priv = psmouse->private;
148 struct input_dev *abs_dev = priv->abs_dev;
149 struct input_dev *pref_dev;
150 u32 status, x, y, z;
151 u32 dummy1, dummy2, dummy3;
152 unsigned int queue_length;
153 unsigned int count = 255;
154
155 while (count--) {
156 /* See if we have motion data. */
157 VMMOUSE_CMD(ABSPOINTER_STATUS, 0,
158 status, dummy1, dummy2, dummy3);
159 if ((status & VMMOUSE_ERROR) == VMMOUSE_ERROR) {
160 psmouse_err(psmouse, "failed to fetch status data\n");
161 /*
162 * After a few attempts this will result in
163 * reconnect.
164 */
165 return PSMOUSE_BAD_DATA;
166 }
167
168 queue_length = status & 0xffff;
169 if (queue_length == 0)
170 break;
171
172 if (queue_length % 4) {
173 psmouse_err(psmouse, "invalid queue length\n");
174 return PSMOUSE_BAD_DATA;
175 }
176
177 /* Now get it */
178 VMMOUSE_CMD(ABSPOINTER_DATA, 4, status, x, y, z);
179
180 /*
181 * And report what we've got. Prefer to report button
182 * events on the same device where we report motion events.
183 * This doesn't work well with the mouse wheel, though. See
184 * below. Ideally we would want to report that on the
185 * preferred device as well.
186 */
187 if (status & VMMOUSE_RELATIVE_PACKET) {
188 pref_dev = rel_dev;
189 input_report_rel(rel_dev, REL_X, (s32)x);
190 input_report_rel(rel_dev, REL_Y, -(s32)y);
191 } else {
192 pref_dev = abs_dev;
193 input_report_abs(abs_dev, ABS_X, x);
194 input_report_abs(abs_dev, ABS_Y, y);
195 }
196
197 /* Xorg seems to ignore wheel events on absolute devices */
198 input_report_rel(rel_dev, REL_WHEEL, -(s8)((u8) z));
199
200 vmmouse_report_button(psmouse, abs_dev, rel_dev,
201 pref_dev, BTN_LEFT,
202 status & VMMOUSE_LEFT_BUTTON);
203 vmmouse_report_button(psmouse, abs_dev, rel_dev,
204 pref_dev, BTN_RIGHT,
205 status & VMMOUSE_RIGHT_BUTTON);
206 vmmouse_report_button(psmouse, abs_dev, rel_dev,
207 pref_dev, BTN_MIDDLE,
208 status & VMMOUSE_MIDDLE_BUTTON);
209 input_sync(abs_dev);
210 input_sync(rel_dev);
211 }
212
213 return PSMOUSE_FULL_PACKET;
214}
215
216/**
217 * vmmouse_process_byte - process data on the ps/2 channel
218 *
219 * @psmouse: Pointer to the psmouse struct
220 *
221 * When the ps/2 channel indicates that there is vmmouse data available,
222 * call vmmouse channel processing. Otherwise, continue to accept bytes. If
223 * there is a synchronization or communication data error, return
224 * PSMOUSE_BAD_DATA in the hope that the caller will reset the mouse.
225 */
226static psmouse_ret_t vmmouse_process_byte(struct psmouse *psmouse)
227{
228 unsigned char *packet = psmouse->packet;
229
230 switch (psmouse->pktcnt) {
231 case 1:
232 return (packet[0] & 0x8) == 0x8 ?
233 PSMOUSE_GOOD_DATA : PSMOUSE_BAD_DATA;
234
235 case 2:
236 return PSMOUSE_GOOD_DATA;
237
238 default:
239 return vmmouse_report_events(psmouse);
240 }
241}
242
243/**
244 * vmmouse_disable - Disable vmmouse
245 *
246 * @psmouse: Pointer to the psmouse struct
247 *
248 * Tries to disable vmmouse mode.
249 */
250static void vmmouse_disable(struct psmouse *psmouse)
251{
252 u32 status;
253 u32 dummy1, dummy2, dummy3, dummy4;
254
255 VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_DISABLE,
256 dummy1, dummy2, dummy3, dummy4);
257
258 VMMOUSE_CMD(ABSPOINTER_STATUS, 0,
259 status, dummy1, dummy2, dummy3);
260
261 if ((status & VMMOUSE_ERROR) != VMMOUSE_ERROR)
262 psmouse_warn(psmouse, "failed to disable vmmouse device\n");
263}
264
265/**
266 * vmmouse_enable - Enable vmmouse and request absolute mode.
267 *
268 * @psmouse: Pointer to the psmouse struct
269 *
270 * Tries to enable vmmouse mode. Performs basic checks and requests
271 * absolute vmmouse mode.
272 * Returns 0 on success, -ENODEV on failure.
273 */
274static int vmmouse_enable(struct psmouse *psmouse)
275{
276 u32 status, version;
277 u32 dummy1, dummy2, dummy3, dummy4;
278
279 /*
280 * Try enabling the device. If successful, we should be able to
281 * read valid version ID back from it.
282 */
283 VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_ENABLE,
284 dummy1, dummy2, dummy3, dummy4);
285
286 /*
287 * See if version ID can be retrieved.
288 */
289 VMMOUSE_CMD(ABSPOINTER_STATUS, 0, status, dummy1, dummy2, dummy3);
290 if ((status & 0x0000ffff) == 0) {
291 psmouse_dbg(psmouse, "empty flags - assuming no device\n");
292 return -ENXIO;
293 }
294
295 VMMOUSE_CMD(ABSPOINTER_DATA, 1 /* single item */,
296 version, dummy1, dummy2, dummy3);
297 if (version != VMMOUSE_VERSION_ID) {
298 psmouse_dbg(psmouse, "Unexpected version value: %u vs %u\n",
299 (unsigned) version, VMMOUSE_VERSION_ID);
300 vmmouse_disable(psmouse);
301 return -ENXIO;
302 }
303
304 /*
305 * Restrict ioport access, if possible.
306 */
307 VMMOUSE_CMD(ABSPOINTER_RESTRICT, VMMOUSE_RESTRICT_CPL0,
308 dummy1, dummy2, dummy3, dummy4);
309
310 VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_REQUEST_ABSOLUTE,
311 dummy1, dummy2, dummy3, dummy4);
312
313 return 0;
314}
315
316/*
317 * Array of supported hypervisors.
318 */
319static enum x86_hypervisor_type vmmouse_supported_hypervisors[] = {
320 X86_HYPER_VMWARE,
321 X86_HYPER_KVM,
322};
323
324/**
325 * vmmouse_check_hypervisor - Check if we're running on a supported hypervisor
326 */
327static bool vmmouse_check_hypervisor(void)
328{
329 int i;
330
331 for (i = 0; i < ARRAY_SIZE(vmmouse_supported_hypervisors); i++)
332 if (vmmouse_supported_hypervisors[i] == x86_hyper_type)
333 return true;
334
335 return false;
336}
337
338/**
339 * vmmouse_detect - Probe whether vmmouse is available
340 *
341 * @psmouse: Pointer to the psmouse struct
342 * @set_properties: Whether to set psmouse name and vendor
343 *
344 * Returns 0 if vmmouse channel is available. Negative error code if not.
345 */
346int vmmouse_detect(struct psmouse *psmouse, bool set_properties)
347{
348 u32 response, version, dummy1, dummy2;
349
350 if (!vmmouse_check_hypervisor()) {
351 psmouse_dbg(psmouse,
352 "VMMouse not running on supported hypervisor.\n");
353 return -ENXIO;
354 }
355
356 /* Check if the device is present */
357 response = ~VMMOUSE_PROTO_MAGIC;
358 VMMOUSE_CMD(GETVERSION, 0, version, response, dummy1, dummy2);
359 if (response != VMMOUSE_PROTO_MAGIC || version == 0xffffffffU)
360 return -ENXIO;
361
362 if (set_properties) {
363 psmouse->vendor = VMMOUSE_VENDOR;
364 psmouse->name = VMMOUSE_NAME;
365 psmouse->model = version;
366 }
367
368 return 0;
369}
370
371/**
372 * vmmouse_disconnect - Take down vmmouse driver
373 *
374 * @psmouse: Pointer to the psmouse struct
375 *
376 * Takes down vmmouse driver and frees resources set up in vmmouse_init().
377 */
378static void vmmouse_disconnect(struct psmouse *psmouse)
379{
380 struct vmmouse_data *priv = psmouse->private;
381
382 vmmouse_disable(psmouse);
383 psmouse_reset(psmouse);
384 input_unregister_device(priv->abs_dev);
385 kfree(priv);
386}
387
388/**
389 * vmmouse_reconnect - Reset the ps/2 - and vmmouse connections
390 *
391 * @psmouse: Pointer to the psmouse struct
392 *
393 * Attempts to reset the mouse connections. Returns 0 on success and
394 * -1 on failure.
395 */
396static int vmmouse_reconnect(struct psmouse *psmouse)
397{
398 int error;
399
400 psmouse_reset(psmouse);
401 vmmouse_disable(psmouse);
402 error = vmmouse_enable(psmouse);
403 if (error) {
404 psmouse_err(psmouse,
405 "Unable to re-enable mouse when reconnecting, err: %d\n",
406 error);
407 return error;
408 }
409
410 return 0;
411}
412
413/**
414 * vmmouse_init - Initialize the vmmouse driver
415 *
416 * @psmouse: Pointer to the psmouse struct
417 *
418 * Requests the device and tries to enable vmmouse mode.
419 * If successful, sets up the input device for relative movement events.
420 * It also allocates another input device and sets it up for absolute motion
421 * events. Returns 0 on success and -1 on failure.
422 */
423int vmmouse_init(struct psmouse *psmouse)
424{
425 struct vmmouse_data *priv;
426 struct input_dev *rel_dev = psmouse->dev, *abs_dev;
427 int error;
428
429 psmouse_reset(psmouse);
430 error = vmmouse_enable(psmouse);
431 if (error)
432 return error;
433
434 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
435 abs_dev = input_allocate_device();
436 if (!priv || !abs_dev) {
437 error = -ENOMEM;
438 goto init_fail;
439 }
440
441 priv->abs_dev = abs_dev;
442 psmouse->private = priv;
443
444 /* Set up and register absolute device */
445 snprintf(priv->phys, sizeof(priv->phys), "%s/input1",
446 psmouse->ps2dev.serio->phys);
447
448 /* Mimic name setup for relative device in psmouse-base.c */
449 snprintf(priv->dev_name, sizeof(priv->dev_name), "%s %s %s",
450 VMMOUSE_PSNAME, VMMOUSE_VENDOR, VMMOUSE_NAME);
451 abs_dev->phys = priv->phys;
452 abs_dev->name = priv->dev_name;
453 abs_dev->id.bustype = BUS_I8042;
454 abs_dev->id.vendor = 0x0002;
455 abs_dev->id.product = PSMOUSE_VMMOUSE;
456 abs_dev->id.version = psmouse->model;
457 abs_dev->dev.parent = &psmouse->ps2dev.serio->dev;
458
459 /* Set absolute device capabilities */
460 input_set_capability(abs_dev, EV_KEY, BTN_LEFT);
461 input_set_capability(abs_dev, EV_KEY, BTN_RIGHT);
462 input_set_capability(abs_dev, EV_KEY, BTN_MIDDLE);
463 input_set_capability(abs_dev, EV_ABS, ABS_X);
464 input_set_capability(abs_dev, EV_ABS, ABS_Y);
465 input_set_abs_params(abs_dev, ABS_X, 0, VMMOUSE_MAX_X, 0, 0);
466 input_set_abs_params(abs_dev, ABS_Y, 0, VMMOUSE_MAX_Y, 0, 0);
467
468 error = input_register_device(priv->abs_dev);
469 if (error)
470 goto init_fail;
471
472 /* Add wheel capability to the relative device */
473 input_set_capability(rel_dev, EV_REL, REL_WHEEL);
474
475 psmouse->protocol_handler = vmmouse_process_byte;
476 psmouse->disconnect = vmmouse_disconnect;
477 psmouse->reconnect = vmmouse_reconnect;
478
479 return 0;
480
481init_fail:
482 vmmouse_disable(psmouse);
483 psmouse_reset(psmouse);
484 input_free_device(abs_dev);
485 kfree(priv);
486 psmouse->private = NULL;
487
488 return error;
489}
490