1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "VirtioGpuStream.h"
18
19 #include <cros_gralloc_handle.h>
20 #include <drm/virtgpu_drm.h>
21 #include <xf86drm.h>
22
23 #include <sys/types.h>
24 #include <sys/mman.h>
25
26 #include <errno.h>
27 #include <unistd.h>
28
29 #ifndef PAGE_SIZE
30 #define PAGE_SIZE 0x1000
31 #endif
32
33 // In a virtual machine, there should only be one GPU
34 #define RENDERNODE_MINOR 128
35
36 // Maximum size of readback / response buffer in bytes
37 #define MAX_CMDRESPBUF_SIZE (10*PAGE_SIZE)
38
39 // Attributes use to allocate our response buffer
40 // Similar to virgl's fence objects
41 #define PIPE_BUFFER 0
42 #define VIRGL_FORMAT_R8_UNORM 64
43 #define VIRGL_BIND_CUSTOM (1 << 17)
44
45 // Conservative; see virgl_winsys.h
46 #define VIRGL_MAX_CMDBUF_DWORDS (16*1024)
47 #define VIRGL_MAX_CMDBUF_SIZE (4*VIRGL_MAX_CMDBUF_DWORDS)
48
49 struct VirtioGpuCmd {
50 uint32_t op;
51 uint32_t cmdSize;
52 unsigned char buf[0];
53 } __attribute__((packed));
54
processPipeInit(HostConnectionType,renderControl_encoder_context_t * rcEnc)55 bool VirtioGpuProcessPipe::processPipeInit(HostConnectionType, renderControl_encoder_context_t *rcEnc)
56 {
57 union {
58 uint64_t proto;
59 struct {
60 int pid;
61 int tid;
62 } id;
63 } puid = {
64 .id.pid = getpid(),
65 .id.tid = gettid(),
66 };
67 rcEnc->rcSetPuid(rcEnc, puid.proto);
68 return true;
69 }
70
VirtioGpuStream(size_t bufSize)71 VirtioGpuStream::VirtioGpuStream(size_t bufSize) :
72 IOStream(0U),
73 m_fd(-1),
74 m_bufSize(bufSize),
75 m_buf(nullptr),
76 m_cmdResp_rh(0U),
77 m_cmdResp_bo(0U),
78 m_cmdResp(nullptr),
79 m_cmdRespPos(0U),
80 m_cmdPos(0U),
81 m_flushPos(0U),
82 m_allocSize(0U),
83 m_allocFlushSize(0U)
84 {
85 }
86
~VirtioGpuStream()87 VirtioGpuStream::~VirtioGpuStream()
88 {
89 if (m_cmdResp) {
90 munmap(m_cmdResp, MAX_CMDRESPBUF_SIZE);
91 }
92
93 if (m_cmdResp_bo > 0U) {
94 drm_gem_close gem_close = {
95 .handle = m_cmdResp_bo,
96 };
97 drmIoctl(m_fd, DRM_IOCTL_GEM_CLOSE, &gem_close);
98 }
99
100 if (m_fd >= 0) {
101 close(m_fd);
102 }
103
104 free(m_buf);
105 }
106
connect()107 int VirtioGpuStream::connect()
108 {
109 if (m_fd < 0) {
110 m_fd = drmOpenRender(RENDERNODE_MINOR);
111 if (m_fd < 0) {
112 ERR("%s: failed with fd %d (%s)", __func__, m_fd, strerror(errno));
113 return -1;
114 }
115 }
116
117 if (!m_cmdResp_bo) {
118 drm_virtgpu_resource_create create = {
119 .target = PIPE_BUFFER,
120 .format = VIRGL_FORMAT_R8_UNORM,
121 .bind = VIRGL_BIND_CUSTOM,
122 .width = MAX_CMDRESPBUF_SIZE,
123 .height = 1U,
124 .depth = 1U,
125 .array_size = 0U,
126 .size = MAX_CMDRESPBUF_SIZE,
127 .stride = MAX_CMDRESPBUF_SIZE,
128 };
129 int ret = drmIoctl(m_fd, DRM_IOCTL_VIRTGPU_RESOURCE_CREATE, &create);
130 if (ret) {
131 ERR("%s: failed with %d allocating command response buffer (%s)",
132 __func__, ret, strerror(errno));
133 return -1;
134 }
135 m_cmdResp_bo = create.bo_handle;
136 if (!m_cmdResp_bo) {
137 ERR("%s: no handle when allocating command response buffer",
138 __func__);
139 return -1;
140 }
141 m_cmdResp_rh = create.res_handle;
142 if (create.size != MAX_CMDRESPBUF_SIZE) {
143 ERR("%s: command response buffer wrongly sized, create.size=%zu "
144 "!= %zu", __func__,
145 static_cast<size_t>(create.size),
146 static_cast<size_t>(MAX_CMDRESPBUF_SIZE));
147 abort();
148 }
149 }
150
151 if (!m_cmdResp) {
152 drm_virtgpu_map map = {
153 .handle = m_cmdResp_bo,
154 };
155 int ret = drmIoctl(m_fd, DRM_IOCTL_VIRTGPU_MAP, &map);
156 if (ret) {
157 ERR("%s: failed with %d mapping command response buffer (%s)",
158 __func__, ret, strerror(errno));
159 return -1;
160 }
161 m_cmdResp = static_cast<VirtioGpuCmd *>(mmap64(nullptr,
162 MAX_CMDRESPBUF_SIZE,
163 PROT_READ, MAP_SHARED,
164 m_fd, map.offset));
165 if (m_cmdResp == MAP_FAILED) {
166 ERR("%s: failed with %d mmap'ing command response buffer (%s)",
167 __func__, ret, strerror(errno));
168 return -1;
169 }
170 }
171
172 return 0;
173 }
174
flush()175 int VirtioGpuStream::flush()
176 {
177 int ret = commitBuffer(m_allocSize - m_allocFlushSize);
178 if (ret)
179 return ret;
180 m_allocFlushSize = m_allocSize;
181 return 0;
182 }
183
allocBuffer(size_t minSize)184 void *VirtioGpuStream::allocBuffer(size_t minSize)
185 {
186 if (m_buf) {
187 // Try to model the alloc() calls being made by the user. They should be
188 // obeying the protocol and using alloc() for anything they don't write
189 // with writeFully(), so we can know if this alloc() is for part of a
190 // command, or not. If it is not for part of a command, we are starting
191 // a new command, and should increment m_cmdPos.
192 VirtioGpuCmd *cmd = reinterpret_cast<VirtioGpuCmd *>(&m_buf[m_cmdPos]);
193 if (m_allocSize + minSize > cmd->cmdSize) {
194 m_allocFlushSize = 0U;
195 m_allocSize = 0U;
196 // This might also be a convenient point to flush commands
197 if (m_cmdPos + cmd->cmdSize + minSize > m_bufSize) {
198 if (commitAll() < 0) {
199 ERR("%s: command flush failed", __func__);
200 m_flushPos = 0U;
201 m_bufSize = 0U;
202 m_cmdPos = 0U;
203 free(m_buf);
204 m_buf = nullptr;
205 return nullptr;
206 }
207 } else {
208 m_cmdPos += cmd->cmdSize;
209 m_flushPos = m_cmdPos;
210 }
211 }
212 }
213
214 // Update m_allocSize here, before minSize is tampered with below
215 m_allocSize += minSize;
216
217 // Make sure anything we already have written to the buffer is retained
218 minSize += m_flushPos;
219
220 size_t allocSize = (m_bufSize < minSize ? minSize : m_bufSize);
221 if (!m_buf) {
222 m_buf = static_cast<unsigned char *>(malloc(allocSize));
223 } else if (m_bufSize < allocSize) {
224 unsigned char *p = static_cast<unsigned char *>(realloc(m_buf, allocSize));
225 if (!p) {
226 free(m_buf);
227 }
228 m_buf = p;
229 }
230 if (!m_buf) {
231 ERR("%s: alloc (%zu) failed\n", __func__, allocSize);
232 m_allocFlushSize = 0U;
233 m_allocSize = 0U;
234 m_flushPos = 0U;
235 m_bufSize = 0U;
236 m_cmdPos = 0U;
237 } else {
238 m_bufSize = allocSize;
239 }
240 if (m_flushPos == 0 && m_cmdPos == 0) {
241 // During initialization, HostConnection will send an empty command
242 // packet to check the connection is good, but it doesn't obey the usual
243 // line protocol. This is a 4 byte write to [0], which is our 'op' field,
244 // and we don't have an op=0 so it's OK. We fake up a valid length, and
245 // overload this workaround by putting the res_handle for the readback
246 // buffer in the command payload, patched in just before we submit.
247 VirtioGpuCmd *cmd = reinterpret_cast<VirtioGpuCmd *>(&m_buf[m_cmdPos]);
248 cmd->op = 0U;
249 cmd->cmdSize = sizeof(*cmd) + sizeof(__u32);
250 }
251 return m_buf + m_cmdPos;
252 }
253
254 // For us, writeFully() means to write a command without any header, directly
255 // into the buffer stream. We can use the packet frame written directly to the
256 // stream to verify this write is within bounds, then update the counter.
257
writeFully(const void * buf,size_t len)258 int VirtioGpuStream::writeFully(const void *buf, size_t len)
259 {
260 if (!valid())
261 return -1;
262
263 if (!buf) {
264 if (len > 0) {
265 // If len is non-zero, buf must not be NULL. Otherwise the pipe would
266 // be in a corrupted state, which is lethal for the emulator.
267 ERR("%s: failed, buf=NULL, len %zu, lethal error, exiting",
268 __func__, len);
269 abort();
270 }
271 return 0;
272 }
273
274 VirtioGpuCmd *cmd = reinterpret_cast<VirtioGpuCmd *>(&m_buf[m_cmdPos]);
275
276 if (m_flushPos < sizeof(*cmd)) {
277 ERR("%s: writeFully len %zu would overwrite command header, "
278 "cmd_pos=%zu, flush_pos=%zu, lethal error, exiting", __func__,
279 len, m_cmdPos, m_flushPos);
280 abort();
281 }
282
283 if (m_flushPos + len > cmd->cmdSize) {
284 ERR("%s: writeFully len %zu would overflow the command bounds, "
285 "cmd_pos=%zu, flush_pos=%zu, cmdsize=%" PRIu32 ", lethal error, exiting",
286 __func__, len, m_cmdPos, m_flushPos, cmd->cmdSize);
287 abort();
288 }
289
290 if (len > VIRGL_MAX_CMDBUF_SIZE) {
291 ERR("%s: Large command (%zu bytes) exceeds virgl limits",
292 __func__, len);
293 /* Fall through */
294 }
295
296 memcpy(&m_buf[m_flushPos], buf, len);
297 commitBuffer(len);
298 m_allocSize += len;
299 return 0;
300 }
301
readFully(void * buf,size_t len)302 const unsigned char *VirtioGpuStream::readFully(void *buf, size_t len)
303 {
304 if (!valid())
305 return nullptr;
306
307 if (!buf) {
308 if (len > 0) {
309 // If len is non-zero, buf must not be NULL. Otherwise the pipe would
310 // be in a corrupted state, which is lethal for the emulator.
311 ERR("%s: failed, buf=NULL, len %zu, lethal error, exiting.",
312 __func__, len);
313 abort();
314 }
315 return nullptr;
316 }
317
318 // Read is too big for current architecture
319 if (len > MAX_CMDRESPBUF_SIZE - sizeof(*m_cmdResp)) {
320 ERR("%s: failed, read too large, len %zu, lethal error, exiting.",
321 __func__, len);
322 abort();
323 }
324
325 // Commit all outstanding write commands (if any)
326 if (commitAll() < 0) {
327 ERR("%s: command flush failed", __func__);
328 return nullptr;
329 }
330
331 if (len > 0U && m_cmdRespPos == 0U) {
332 // When we are about to read for the first time, wait for the virtqueue
333 // to drain to this command, otherwise the data could be stale
334 drm_virtgpu_3d_wait wait = {
335 .handle = m_cmdResp_bo,
336 };
337 int ret = drmIoctl(m_fd, DRM_IOCTL_VIRTGPU_WAIT, &wait);
338 if (ret) {
339 ERR("%s: failed with %d waiting for response buffer (%s)",
340 __func__, ret, strerror(errno));
341 // Fall through, hope for the best
342 }
343 }
344
345 // Most likely a protocol implementation error
346 if (m_cmdResp->cmdSize - sizeof(*m_cmdResp) < m_cmdRespPos + len) {
347 ERR("%s: failed, op %" PRIu32 ", len %zu, cmdSize %" PRIu32 ", pos %zu, lethal "
348 "error, exiting.", __func__, m_cmdResp->op, len,
349 m_cmdResp->cmdSize, m_cmdRespPos);
350 abort();
351 }
352
353 memcpy(buf, &m_cmdResp->buf[m_cmdRespPos], len);
354
355 if (m_cmdRespPos + len == m_cmdResp->cmdSize - sizeof(*m_cmdResp)) {
356 m_cmdRespPos = 0U;
357 } else {
358 m_cmdRespPos += len;
359 }
360
361 return reinterpret_cast<const unsigned char *>(buf);
362 }
363
commitBuffer(size_t size)364 int VirtioGpuStream::commitBuffer(size_t size)
365 {
366 if (m_flushPos + size > m_bufSize) {
367 ERR("%s: illegal commit size %zu, flushPos %zu, bufSize %zu",
368 __func__, size, m_flushPos, m_bufSize);
369 return -1;
370 }
371 m_flushPos += size;
372 return 0;
373 }
374
commitAll()375 int VirtioGpuStream::commitAll()
376 {
377 size_t pos = 0U, numFlushed = 0U;
378 while (pos < m_flushPos) {
379 VirtioGpuCmd *cmd = reinterpret_cast<VirtioGpuCmd *>(&m_buf[pos]);
380
381 // Should never happen
382 if (pos + cmd->cmdSize > m_bufSize) {
383 ERR("%s: failed, pos %zu, cmdSize %" PRIu32 ", bufSize %zu, lethal "
384 "error, exiting.", __func__, pos, cmd->cmdSize, m_bufSize);
385 abort();
386 }
387
388 // Saw dummy command; patch it with res handle
389 if (cmd->op == 0) {
390 *(uint32_t *)cmd->buf = m_cmdResp_rh;
391 }
392
393 // Flush a single command
394 drm_virtgpu_execbuffer execbuffer = {
395 .size = cmd->cmdSize,
396 .command = reinterpret_cast<__u64>(cmd),
397 .bo_handles = reinterpret_cast<__u64>(&m_cmdResp_bo),
398 .num_bo_handles = 1U,
399 };
400 int ret = drmIoctl(m_fd, DRM_IOCTL_VIRTGPU_EXECBUFFER, &execbuffer);
401 if (ret) {
402 ERR("%s: failed with %d executing command buffer (%s)", __func__,
403 ret, strerror(errno));
404 return -1;
405 }
406
407 pos += cmd->cmdSize;
408 numFlushed++;
409 }
410
411 if (pos > m_flushPos) {
412 ERR("%s: aliasing, flushPos %zu, pos %zu, probably ok", __func__,
413 m_flushPos, pos);
414 /* Fall through */
415 }
416
417 m_flushPos = 0U;
418 m_cmdPos = 0U;
419 return 0;
420 }
421