1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for Virtual PS/2 Mouse on VMware and QEMU hypervisors.
4 *
5 * Copyright (C) 2014, VMware, Inc. All Rights Reserved.
6 *
7 * Twin device code is hugely inspired by the ALPS driver.
8 * Authors:
9 * Dmitry Torokhov <dmitry.torokhov@gmail.com>
10 * Thomas Hellstrom <thellstrom@vmware.com>
11 */
12
13 #include <linux/input.h>
14 #include <linux/serio.h>
15 #include <linux/libps2.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <asm/hypervisor.h>
19 #include <asm/vmware.h>
20
21 #include "psmouse.h"
22 #include "vmmouse.h"
23
24 #define VMMOUSE_PROTO_MAGIC 0x564D5868U
25
26 /*
27 * Main commands supported by the vmmouse hypervisor port.
28 */
29 #define VMMOUSE_PROTO_CMD_GETVERSION 10
30 #define VMMOUSE_PROTO_CMD_ABSPOINTER_DATA 39
31 #define VMMOUSE_PROTO_CMD_ABSPOINTER_STATUS 40
32 #define VMMOUSE_PROTO_CMD_ABSPOINTER_COMMAND 41
33 #define VMMOUSE_PROTO_CMD_ABSPOINTER_RESTRICT 86
34
35 /*
36 * Subcommands for VMMOUSE_PROTO_CMD_ABSPOINTER_COMMAND
37 */
38 #define VMMOUSE_CMD_ENABLE 0x45414552U
39 #define VMMOUSE_CMD_DISABLE 0x000000f5U
40 #define VMMOUSE_CMD_REQUEST_RELATIVE 0x4c455252U
41 #define VMMOUSE_CMD_REQUEST_ABSOLUTE 0x53424152U
42
43 #define VMMOUSE_ERROR 0xffff0000U
44
45 #define VMMOUSE_VERSION_ID 0x3442554aU
46
47 #define VMMOUSE_RELATIVE_PACKET 0x00010000U
48
49 #define VMMOUSE_LEFT_BUTTON 0x20
50 #define VMMOUSE_RIGHT_BUTTON 0x10
51 #define VMMOUSE_MIDDLE_BUTTON 0x08
52
53 /*
54 * VMMouse Restrict command
55 */
56 #define VMMOUSE_RESTRICT_ANY 0x00
57 #define VMMOUSE_RESTRICT_CPL0 0x01
58 #define VMMOUSE_RESTRICT_IOPL 0x02
59
60 #define VMMOUSE_MAX_X 0xFFFF
61 #define VMMOUSE_MAX_Y 0xFFFF
62
63 #define VMMOUSE_VENDOR "VMware"
64 #define VMMOUSE_NAME "VMMouse"
65
66 /**
67 * struct vmmouse_data - private data structure for the vmmouse driver
68 *
69 * @abs_dev: "Absolute" device used to report absolute mouse movement.
70 * @phys: Physical path for the absolute device.
71 * @dev_name: Name attribute name for the absolute device.
72 */
73 struct vmmouse_data {
74 struct input_dev *abs_dev;
75 char phys[32];
76 char dev_name[128];
77 };
78
79 /**
80 * Hypervisor-specific bi-directional communication channel
81 * implementing the vmmouse protocol. Should never execute on
82 * bare metal hardware.
83 */
84 #define VMMOUSE_CMD(cmd, in1, out1, out2, out3, out4) \
85 ({ \
86 unsigned long __dummy1, __dummy2; \
87 __asm__ __volatile__ (VMWARE_HYPERCALL : \
88 "=a"(out1), \
89 "=b"(out2), \
90 "=c"(out3), \
91 "=d"(out4), \
92 "=S"(__dummy1), \
93 "=D"(__dummy2) : \
94 "a"(VMMOUSE_PROTO_MAGIC), \
95 "b"(in1), \
96 "c"(VMMOUSE_PROTO_CMD_##cmd), \
97 "d"(0) : \
98 "memory"); \
99 })
100
101 /**
102 * vmmouse_report_button - report button state on the correct input device
103 *
104 * @psmouse: Pointer to the psmouse struct
105 * @abs_dev: The absolute input device
106 * @rel_dev: The relative input device
107 * @pref_dev: The preferred device for reporting
108 * @code: Button code
109 * @value: Button value
110 *
111 * Report @value and @code on @pref_dev, unless the button is already
112 * pressed on the other device, in which case the state is reported on that
113 * device.
114 */
vmmouse_report_button(struct psmouse * psmouse,struct input_dev * abs_dev,struct input_dev * rel_dev,struct input_dev * pref_dev,unsigned int code,int value)115 static void vmmouse_report_button(struct psmouse *psmouse,
116 struct input_dev *abs_dev,
117 struct input_dev *rel_dev,
118 struct input_dev *pref_dev,
119 unsigned int code, int value)
120 {
121 if (test_bit(code, abs_dev->key))
122 pref_dev = abs_dev;
123 else if (test_bit(code, rel_dev->key))
124 pref_dev = rel_dev;
125
126 input_report_key(pref_dev, code, value);
127 }
128
129 /**
130 * vmmouse_report_events - process events on the vmmouse communications channel
131 *
132 * @psmouse: Pointer to the psmouse struct
133 *
134 * This function pulls events from the vmmouse communications channel and
135 * reports them on the correct (absolute or relative) input device. When the
136 * communications channel is drained, or if we've processed more than 255
137 * psmouse commands, the function returns PSMOUSE_FULL_PACKET. If there is a
138 * host- or synchronization error, the function returns PSMOUSE_BAD_DATA in
139 * the hope that the caller will reset the communications channel.
140 */
vmmouse_report_events(struct psmouse * psmouse)141 static psmouse_ret_t vmmouse_report_events(struct psmouse *psmouse)
142 {
143 struct input_dev *rel_dev = psmouse->dev;
144 struct vmmouse_data *priv = psmouse->private;
145 struct input_dev *abs_dev = priv->abs_dev;
146 struct input_dev *pref_dev;
147 u32 status, x, y, z;
148 u32 dummy1, dummy2, dummy3;
149 unsigned int queue_length;
150 unsigned int count = 255;
151
152 while (count--) {
153 /* See if we have motion data. */
154 VMMOUSE_CMD(ABSPOINTER_STATUS, 0,
155 status, dummy1, dummy2, dummy3);
156 if ((status & VMMOUSE_ERROR) == VMMOUSE_ERROR) {
157 psmouse_err(psmouse, "failed to fetch status data\n");
158 /*
159 * After a few attempts this will result in
160 * reconnect.
161 */
162 return PSMOUSE_BAD_DATA;
163 }
164
165 queue_length = status & 0xffff;
166 if (queue_length == 0)
167 break;
168
169 if (queue_length % 4) {
170 psmouse_err(psmouse, "invalid queue length\n");
171 return PSMOUSE_BAD_DATA;
172 }
173
174 /* Now get it */
175 VMMOUSE_CMD(ABSPOINTER_DATA, 4, status, x, y, z);
176
177 /*
178 * And report what we've got. Prefer to report button
179 * events on the same device where we report motion events.
180 * This doesn't work well with the mouse wheel, though. See
181 * below. Ideally we would want to report that on the
182 * preferred device as well.
183 */
184 if (status & VMMOUSE_RELATIVE_PACKET) {
185 pref_dev = rel_dev;
186 input_report_rel(rel_dev, REL_X, (s32)x);
187 input_report_rel(rel_dev, REL_Y, -(s32)y);
188 } else {
189 pref_dev = abs_dev;
190 input_report_abs(abs_dev, ABS_X, x);
191 input_report_abs(abs_dev, ABS_Y, y);
192 }
193
194 /* Xorg seems to ignore wheel events on absolute devices */
195 input_report_rel(rel_dev, REL_WHEEL, -(s8)((u8) z));
196
197 vmmouse_report_button(psmouse, abs_dev, rel_dev,
198 pref_dev, BTN_LEFT,
199 status & VMMOUSE_LEFT_BUTTON);
200 vmmouse_report_button(psmouse, abs_dev, rel_dev,
201 pref_dev, BTN_RIGHT,
202 status & VMMOUSE_RIGHT_BUTTON);
203 vmmouse_report_button(psmouse, abs_dev, rel_dev,
204 pref_dev, BTN_MIDDLE,
205 status & VMMOUSE_MIDDLE_BUTTON);
206 input_sync(abs_dev);
207 input_sync(rel_dev);
208 }
209
210 return PSMOUSE_FULL_PACKET;
211 }
212
213 /**
214 * vmmouse_process_byte - process data on the ps/2 channel
215 *
216 * @psmouse: Pointer to the psmouse struct
217 *
218 * When the ps/2 channel indicates that there is vmmouse data available,
219 * call vmmouse channel processing. Otherwise, continue to accept bytes. If
220 * there is a synchronization or communication data error, return
221 * PSMOUSE_BAD_DATA in the hope that the caller will reset the mouse.
222 */
vmmouse_process_byte(struct psmouse * psmouse)223 static psmouse_ret_t vmmouse_process_byte(struct psmouse *psmouse)
224 {
225 unsigned char *packet = psmouse->packet;
226
227 switch (psmouse->pktcnt) {
228 case 1:
229 return (packet[0] & 0x8) == 0x8 ?
230 PSMOUSE_GOOD_DATA : PSMOUSE_BAD_DATA;
231
232 case 2:
233 return PSMOUSE_GOOD_DATA;
234
235 default:
236 return vmmouse_report_events(psmouse);
237 }
238 }
239
240 /**
241 * vmmouse_disable - Disable vmmouse
242 *
243 * @psmouse: Pointer to the psmouse struct
244 *
245 * Tries to disable vmmouse mode.
246 */
vmmouse_disable(struct psmouse * psmouse)247 static void vmmouse_disable(struct psmouse *psmouse)
248 {
249 u32 status;
250 u32 dummy1, dummy2, dummy3, dummy4;
251
252 VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_DISABLE,
253 dummy1, dummy2, dummy3, dummy4);
254
255 VMMOUSE_CMD(ABSPOINTER_STATUS, 0,
256 status, dummy1, dummy2, dummy3);
257
258 if ((status & VMMOUSE_ERROR) != VMMOUSE_ERROR)
259 psmouse_warn(psmouse, "failed to disable vmmouse device\n");
260 }
261
262 /**
263 * vmmouse_enable - Enable vmmouse and request absolute mode.
264 *
265 * @psmouse: Pointer to the psmouse struct
266 *
267 * Tries to enable vmmouse mode. Performs basic checks and requests
268 * absolute vmmouse mode.
269 * Returns 0 on success, -ENODEV on failure.
270 */
vmmouse_enable(struct psmouse * psmouse)271 static int vmmouse_enable(struct psmouse *psmouse)
272 {
273 u32 status, version;
274 u32 dummy1, dummy2, dummy3, dummy4;
275
276 /*
277 * Try enabling the device. If successful, we should be able to
278 * read valid version ID back from it.
279 */
280 VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_ENABLE,
281 dummy1, dummy2, dummy3, dummy4);
282
283 /*
284 * See if version ID can be retrieved.
285 */
286 VMMOUSE_CMD(ABSPOINTER_STATUS, 0, status, dummy1, dummy2, dummy3);
287 if ((status & 0x0000ffff) == 0) {
288 psmouse_dbg(psmouse, "empty flags - assuming no device\n");
289 return -ENXIO;
290 }
291
292 VMMOUSE_CMD(ABSPOINTER_DATA, 1 /* single item */,
293 version, dummy1, dummy2, dummy3);
294 if (version != VMMOUSE_VERSION_ID) {
295 psmouse_dbg(psmouse, "Unexpected version value: %u vs %u\n",
296 (unsigned) version, VMMOUSE_VERSION_ID);
297 vmmouse_disable(psmouse);
298 return -ENXIO;
299 }
300
301 /*
302 * Restrict ioport access, if possible.
303 */
304 VMMOUSE_CMD(ABSPOINTER_RESTRICT, VMMOUSE_RESTRICT_CPL0,
305 dummy1, dummy2, dummy3, dummy4);
306
307 VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_REQUEST_ABSOLUTE,
308 dummy1, dummy2, dummy3, dummy4);
309
310 return 0;
311 }
312
313 /*
314 * Array of supported hypervisors.
315 */
316 static enum x86_hypervisor_type vmmouse_supported_hypervisors[] = {
317 X86_HYPER_VMWARE,
318 X86_HYPER_KVM,
319 };
320
321 /**
322 * vmmouse_check_hypervisor - Check if we're running on a supported hypervisor
323 */
vmmouse_check_hypervisor(void)324 static bool vmmouse_check_hypervisor(void)
325 {
326 int i;
327
328 for (i = 0; i < ARRAY_SIZE(vmmouse_supported_hypervisors); i++)
329 if (vmmouse_supported_hypervisors[i] == x86_hyper_type)
330 return true;
331
332 return false;
333 }
334
335 /**
336 * vmmouse_detect - Probe whether vmmouse is available
337 *
338 * @psmouse: Pointer to the psmouse struct
339 * @set_properties: Whether to set psmouse name and vendor
340 *
341 * Returns 0 if vmmouse channel is available. Negative error code if not.
342 */
vmmouse_detect(struct psmouse * psmouse,bool set_properties)343 int vmmouse_detect(struct psmouse *psmouse, bool set_properties)
344 {
345 u32 response, version, dummy1, dummy2;
346
347 if (!vmmouse_check_hypervisor()) {
348 psmouse_dbg(psmouse,
349 "VMMouse not running on supported hypervisor.\n");
350 return -ENXIO;
351 }
352
353 /* Check if the device is present */
354 response = ~VMMOUSE_PROTO_MAGIC;
355 VMMOUSE_CMD(GETVERSION, 0, version, response, dummy1, dummy2);
356 if (response != VMMOUSE_PROTO_MAGIC || version == 0xffffffffU)
357 return -ENXIO;
358
359 if (set_properties) {
360 psmouse->vendor = VMMOUSE_VENDOR;
361 psmouse->name = VMMOUSE_NAME;
362 psmouse->model = version;
363 }
364
365 return 0;
366 }
367
368 /**
369 * vmmouse_disconnect - Take down vmmouse driver
370 *
371 * @psmouse: Pointer to the psmouse struct
372 *
373 * Takes down vmmouse driver and frees resources set up in vmmouse_init().
374 */
vmmouse_disconnect(struct psmouse * psmouse)375 static void vmmouse_disconnect(struct psmouse *psmouse)
376 {
377 struct vmmouse_data *priv = psmouse->private;
378
379 vmmouse_disable(psmouse);
380 psmouse_reset(psmouse);
381 input_unregister_device(priv->abs_dev);
382 kfree(priv);
383 }
384
385 /**
386 * vmmouse_reconnect - Reset the ps/2 - and vmmouse connections
387 *
388 * @psmouse: Pointer to the psmouse struct
389 *
390 * Attempts to reset the mouse connections. Returns 0 on success and
391 * -1 on failure.
392 */
vmmouse_reconnect(struct psmouse * psmouse)393 static int vmmouse_reconnect(struct psmouse *psmouse)
394 {
395 int error;
396
397 psmouse_reset(psmouse);
398 vmmouse_disable(psmouse);
399 error = vmmouse_enable(psmouse);
400 if (error) {
401 psmouse_err(psmouse,
402 "Unable to re-enable mouse when reconnecting, err: %d\n",
403 error);
404 return error;
405 }
406
407 return 0;
408 }
409
410 /**
411 * vmmouse_init - Initialize the vmmouse driver
412 *
413 * @psmouse: Pointer to the psmouse struct
414 *
415 * Requests the device and tries to enable vmmouse mode.
416 * If successful, sets up the input device for relative movement events.
417 * It also allocates another input device and sets it up for absolute motion
418 * events. Returns 0 on success and -1 on failure.
419 */
vmmouse_init(struct psmouse * psmouse)420 int vmmouse_init(struct psmouse *psmouse)
421 {
422 struct vmmouse_data *priv;
423 struct input_dev *rel_dev = psmouse->dev, *abs_dev;
424 int error;
425
426 psmouse_reset(psmouse);
427 error = vmmouse_enable(psmouse);
428 if (error)
429 return error;
430
431 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
432 abs_dev = input_allocate_device();
433 if (!priv || !abs_dev) {
434 error = -ENOMEM;
435 goto init_fail;
436 }
437
438 priv->abs_dev = abs_dev;
439 psmouse->private = priv;
440
441 /* Set up and register absolute device */
442 snprintf(priv->phys, sizeof(priv->phys), "%s/input1",
443 psmouse->ps2dev.serio->phys);
444
445 /* Mimic name setup for relative device in psmouse-base.c */
446 snprintf(priv->dev_name, sizeof(priv->dev_name), "%s %s %s",
447 VMMOUSE_PSNAME, VMMOUSE_VENDOR, VMMOUSE_NAME);
448 abs_dev->phys = priv->phys;
449 abs_dev->name = priv->dev_name;
450 abs_dev->id.bustype = BUS_I8042;
451 abs_dev->id.vendor = 0x0002;
452 abs_dev->id.product = PSMOUSE_VMMOUSE;
453 abs_dev->id.version = psmouse->model;
454 abs_dev->dev.parent = &psmouse->ps2dev.serio->dev;
455
456 /* Set absolute device capabilities */
457 input_set_capability(abs_dev, EV_KEY, BTN_LEFT);
458 input_set_capability(abs_dev, EV_KEY, BTN_RIGHT);
459 input_set_capability(abs_dev, EV_KEY, BTN_MIDDLE);
460 input_set_capability(abs_dev, EV_ABS, ABS_X);
461 input_set_capability(abs_dev, EV_ABS, ABS_Y);
462 input_set_abs_params(abs_dev, ABS_X, 0, VMMOUSE_MAX_X, 0, 0);
463 input_set_abs_params(abs_dev, ABS_Y, 0, VMMOUSE_MAX_Y, 0, 0);
464
465 error = input_register_device(priv->abs_dev);
466 if (error)
467 goto init_fail;
468
469 /* Add wheel capability to the relative device */
470 input_set_capability(rel_dev, EV_REL, REL_WHEEL);
471
472 psmouse->protocol_handler = vmmouse_process_byte;
473 psmouse->disconnect = vmmouse_disconnect;
474 psmouse->reconnect = vmmouse_reconnect;
475
476 return 0;
477
478 init_fail:
479 vmmouse_disable(psmouse);
480 psmouse_reset(psmouse);
481 input_free_device(abs_dev);
482 kfree(priv);
483 psmouse->private = NULL;
484
485 return error;
486 }
487
