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qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
1 QEMU Barrier Client
2
3
4* About
5
6 Barrier is a KVM (Keyboard-Video-Mouse) software forked from Symless's
7 synergy 1.9 codebase.
8
9 See https://github.com/debauchee/barrier
10
11* QEMU usage
12
13 Generally, mouse and keyboard are grabbed through the QEMU video
14 interface emulation.
15
16 But when we want to use a video graphic adapter via a PCI passthrough
17 there is no way to provide the keyboard and mouse inputs to the VM
18 except by plugging a second set of mouse and keyboard to the host
19 or by installing a KVM software in the guest OS.
20
21 The QEMU Barrier client avoids this by implementing directly the Barrier
22 protocol into QEMU.
23
24 This protocol is enabled by adding an input-barrier object to QEMU.
25
26 Syntax: input-barrier,id=<object-id>,name=<guest display name>
27 [,server=<barrier server address>][,port=<barrier server port>]
28 [,x-origin=<x-origin>][,y-origin=<y-origin>]
29 [,width=<width>][,height=<height>]
30
31 The object can be added on the QEMU command line, for instance with:
32
33 ... -object input-barrier,id=barrier0,name=VM-1 ...
34
35 where VM-1 is the name the display configured int the Barrier server
36 on the host providing the mouse and the keyboard events.
37
38 by default <barrier server address> is "localhost", port is 24800,
39 <x-origin> and <y-origin> are set to 0, <width> and <height> to
40 1920 and 1080.
41
42 If Barrier server is stopped QEMU needs to be reconnected manually,
43 by removing and re-adding the input-barrier object, for instance
44 with the help of the HMP monitor:
45
46 (qemu) object_del barrier0
47 (qemu) object_add input-barrier,id=barrier0,name=VM-1
48
49* Message format
50
51 Message format between the server and client is in two parts:
52
53 1- the payload length is a 32bit integer in network endianness,
54 2- the payload
55
56 The payload starts with a 4byte string (without NUL) which is the
57 command. The first command between the server and the client
58 is the only command not encoded on 4 bytes ("Barrier").
59 The remaining part of the payload is decoded according to the command.
60
61* Protocol Description (from barrier/src/lib/barrier/protocol_types.h)
62
63 - barrierCmdHello "Barrier"
64
65 Direction: server -> client
66 Parameters: { int16_t minor, int16_t major }
67 Description:
68
69 Say hello to client
70 minor = protocol major version number supported by server
71 major = protocol minor version number supported by server
72
73 - barrierCmdHelloBack "Barrier"
74
75 Direction: client ->server
76 Parameters: { int16_t minor, int16_t major, char *name}
77 Description:
78
79 Respond to hello from server
80 minor = protocol major version number supported by client
81 major = protocol minor version number supported by client
82 name = client name
83
84 - barrierCmdDInfo "DINF"
85
86 Direction: client ->server
87 Parameters: { int16_t x_origin, int16_t y_origin, int16_t width, int16_t height, int16_t x, int16_t y}
88 Description:
89
90 The client screen must send this message in response to the
91 barrierCmdQInfo message. It must also send this message when the
92 screen's resolution changes. In this case, the client screen should
93 ignore any barrierCmdDMouseMove messages until it receives a
94 barrierCmdCInfoAck in order to prevent attempts to move the mouse off
95 the new screen area.
96
97 - barrierCmdCNoop "CNOP"
98
99 Direction: client -> server
100 Parameters: None
101 Description:
102
103 No operation
104
105 - barrierCmdCClose "CBYE"
106
107 Direction: server -> client
108 Parameters: None
109 Description:
110
111 Close connection
112
113 - barrierCmdCEnter "CINN"
114
115 Direction: server -> client
116 Parameters: { int16_t x, int16_t y, int32_t seq, int16_t modifier }
117 Description:
118
119 Enter screen.
120 x,y = entering screen absolute coordinates
121 seq = sequence number, which is used to order messages between
122 screens. the secondary screen must return this number
123 with some messages
124 modifier = modifier key mask. this will have bits set for each
125 toggle modifier key that is activated on entry to the
126 screen. the secondary screen should adjust its toggle
127 modifiers to reflect that state.
128
129 - barrierCmdCLeave "COUT"
130
131 Direction: server -> client
132 Parameters: None
133 Description:
134
135 Leaving screen. the secondary screen should send clipboard data in
136 response to this message for those clipboards that it has grabbed
137 (i.e. has sent a barrierCmdCClipboard for and has not received a
138 barrierCmdCClipboard for with a greater sequence number) and that
139 were grabbed or have changed since the last leave.
140
141 - barrierCmdCClipboard "CCLP"
142
143 Direction: server -> client
144 Parameters: { int8_t id, int32_t seq }
145 Description:
146
147 Grab clipboard. Sent by screen when some other app on that screen
148 grabs a clipboard.
149 id = the clipboard identifier
150 seq = sequence number. Client must use the sequence number passed in
151 the most recent barrierCmdCEnter. the server always sends 0.
152
153 - barrierCmdCScreenSaver "CSEC"
154
155 Direction: server -> client
156 Parameters: { int8_t started }
157 Description:
158
159 Screensaver change.
160 started = Screensaver on primary has started (1) or closed (0)
161
162 - barrierCmdCResetOptions "CROP"
163
164 Direction: server -> client
165 Parameters: None
166 Description:
167
168 Reset options. Client should reset all of its options to their
169 defaults.
170
171 - barrierCmdCInfoAck "CIAK"
172
173 Direction: server -> client
174 Parameters: None
175 Description:
176
177 Resolution change acknowledgment. Sent by server in response to a
178 client screen's barrierCmdDInfo. This is sent for every
179 barrierCmdDInfo, whether or not the server had sent a barrierCmdQInfo.
180
181 - barrierCmdCKeepAlive "CALV"
182
183 Direction: server -> client
184 Parameters: None
185 Description:
186
187 Keep connection alive. Sent by the server periodically to verify
188 that connections are still up and running. clients must reply in
189 kind on receipt. if the server gets an error sending the message or
190 does not receive a reply within a reasonable time then the server
191 disconnects the client. if the client doesn't receive these (or any
192 message) periodically then it should disconnect from the server. the
193 appropriate interval is defined by an option.
194
195 - barrierCmdDKeyDown "DKDN"
196
197 Direction: server -> client
198 Parameters: { int16_t keyid, int16_t modifier [,int16_t button] }
199 Description:
200
201 Key pressed.
202 keyid = X11 key id
203 modified = modified mask
204 button = X11 Xkb keycode (optional)
205
206 - barrierCmdDKeyRepeat "DKRP"
207
208 Direction: server -> client
209 Parameters: { int16_t keyid, int16_t modifier, int16_t repeat [,int16_t button] }
210 Description:
211
212 Key auto-repeat.
213 keyid = X11 key id
214 modified = modified mask
215 repeat = number of repeats
216 button = X11 Xkb keycode (optional)
217
218 - barrierCmdDKeyUp "DKUP"
219
220 Direction: server -> client
221 Parameters: { int16_t keyid, int16_t modifier [,int16_t button] }
222 Description:
223
224 Key released.
225 keyid = X11 key id
226 modified = modified mask
227 button = X11 Xkb keycode (optional)
228
229 - barrierCmdDMouseDown "DMDN"
230
231 Direction: server -> client
232 Parameters: { int8_t button }
233 Description:
234
235 Mouse button pressed.
236 button = button id
237
238 - barrierCmdDMouseUp "DMUP"
239
240 Direction: server -> client
241 Parameters: { int8_t button }
242 Description:
243
244 Mouse button release.
245 button = button id
246
247 - barrierCmdDMouseMove "DMMV"
248
249 Direction: server -> client
250 Parameters: { int16_t x, int16_t y }
251 Description:
252
253 Absolute mouse moved.
254 x,y = absolute screen coordinates
255
256 - barrierCmdDMouseRelMove "DMRM"
257
258 Direction: server -> client
259 Parameters: { int16_t x, int16_t y }
260 Description:
261
262 Relative mouse moved.
263 x,y = r relative screen coordinates
264
265 - barrierCmdDMouseWheel "DMWM"
266
267 Direction: server -> client
268 Parameters: { int16_t x , int16_t y } or { int16_t y }
269 Description:
270
271 Mouse scroll. The delta should be +120 for one tick forward (away
272 from the user) or right and -120 for one tick backward (toward the
273 user) or left.
274 x = x delta
275 y = y delta
276
277 - barrierCmdDClipboard "DCLP"
278
279 Direction: server -> client
280 Parameters: { int8_t id, int32_t seq, int8_t mark, char *data }
281 Description:
282
283 Clipboard data.
284 id = clipboard id
285 seq = sequence number. The sequence number is 0 when sent by the
286 server. Client screens should use the/ sequence number from
287 the most recent barrierCmdCEnter.
288
289 - barrierCmdDSetOptions "DSOP"
290
291 Direction: server -> client
292 Parameters: { int32 t nb, { int32_t id, int32_t val }[] }
293 Description:
294
295 Set options. Client should set the given option/value pairs.
296 nb = numbers of { id, val } entries
297 id = option id
298 val = option new value
299
300 - barrierCmdDFileTransfer "DFTR"
301
302 Direction: server -> client
303 Parameters: { int8_t mark, char *content }
304 Description:
305
306 Transfer file data.
307 mark = 0 means the content followed is the file size
308 1 means the content followed is the chunk data
309 2 means the file transfer is finished
310
311 - barrierCmdDDragInfo "DDRG" int16_t char *
312
313 Direction: server -> client
314 Parameters: { int16_t nb, char *content }
315 Description:
316
317 Drag information.
318 nb = number of dragging objects
319 content = object's directory
320
321 - barrierCmdQInfo "QINF"
322
323 Direction: server -> client
324 Parameters: None
325 Description:
326
327 Query screen info
328 Client should reply with a barrierCmdDInfo
329
330 - barrierCmdEIncompatible "EICV"
331
332 Direction: server -> client
333 Parameters: { int16_t nb, major *minor }
334 Description:
335
336 Incompatible version.
337 major = major version
338 minor = minor version
339
340 - barrierCmdEBusy "EBSY"
341
342 Direction: server -> client
343 Parameters: None
344 Description:
345
346 Name provided when connecting is already in use.
347
348 - barrierCmdEUnknown "EUNK"
349
350 Direction: server -> client
351 Parameters: None
352 Description:
353
354 Unknown client. Name provided when connecting is not in primary's
355 screen configuration map.
356
357 - barrierCmdEBad "EBAD"
358
359 Direction: server -> client
360 Parameters: None
361 Description:
362
363 Protocol violation. Server should disconnect after sending this
364 message.
365
366* TO DO
367
368 - Enable SSL
369 - Manage SetOptions/ResetOptions commands
370