i386: Fix pkg_id offset for EPYC cpu models
[qemu.git] / contrib / ivshmem-server / ivshmem-server.c
1 /*
2 * Copyright 6WIND S.A., 2014
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2 or
5 * (at your option) any later version. See the COPYING file in the
6 * top-level directory.
7 */
8 #include "qemu/osdep.h"
9 #include "qemu/host-utils.h"
10 #include "qemu/sockets.h"
11
12 #include <sys/socket.h>
13 #include <sys/un.h>
14
15 #include "ivshmem-server.h"
16
17 /* log a message on stdout if verbose=1 */
18 #define IVSHMEM_SERVER_DEBUG(server, fmt, ...) do { \
19 if ((server)->verbose) { \
20 printf(fmt, ## __VA_ARGS__); \
21 } \
22 } while (0)
23
24 /** maximum size of a huge page, used by ivshmem_server_ftruncate() */
25 #define IVSHMEM_SERVER_MAX_HUGEPAGE_SIZE (1024 * 1024 * 1024)
26
27 /** default listen backlog (number of sockets not accepted) */
28 #define IVSHMEM_SERVER_LISTEN_BACKLOG 10
29
30 /* send message to a client unix socket */
31 static int
32 ivshmem_server_send_one_msg(int sock_fd, int64_t peer_id, int fd)
33 {
34 int ret;
35 struct msghdr msg;
36 struct iovec iov[1];
37 union {
38 struct cmsghdr cmsg;
39 char control[CMSG_SPACE(sizeof(int))];
40 } msg_control;
41 struct cmsghdr *cmsg;
42
43 peer_id = GINT64_TO_LE(peer_id);
44 iov[0].iov_base = &peer_id;
45 iov[0].iov_len = sizeof(peer_id);
46
47 memset(&msg, 0, sizeof(msg));
48 msg.msg_iov = iov;
49 msg.msg_iovlen = 1;
50
51 /* if fd is specified, add it in a cmsg */
52 if (fd >= 0) {
53 memset(&msg_control, 0, sizeof(msg_control));
54 msg.msg_control = &msg_control;
55 msg.msg_controllen = sizeof(msg_control);
56 cmsg = CMSG_FIRSTHDR(&msg);
57 cmsg->cmsg_level = SOL_SOCKET;
58 cmsg->cmsg_type = SCM_RIGHTS;
59 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
60 memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));
61 }
62
63 ret = sendmsg(sock_fd, &msg, 0);
64 if (ret <= 0) {
65 return -1;
66 }
67
68 return 0;
69 }
70
71 /* free a peer when the server advertises a disconnection or when the
72 * server is freed */
73 static void
74 ivshmem_server_free_peer(IvshmemServer *server, IvshmemServerPeer *peer)
75 {
76 unsigned vector;
77 IvshmemServerPeer *other_peer;
78
79 IVSHMEM_SERVER_DEBUG(server, "free peer %" PRId64 "\n", peer->id);
80 close(peer->sock_fd);
81 QTAILQ_REMOVE(&server->peer_list, peer, next);
82
83 /* advertise the deletion to other peers */
84 QTAILQ_FOREACH(other_peer, &server->peer_list, next) {
85 ivshmem_server_send_one_msg(other_peer->sock_fd, peer->id, -1);
86 }
87
88 for (vector = 0; vector < peer->vectors_count; vector++) {
89 event_notifier_cleanup(&peer->vectors[vector]);
90 }
91
92 g_free(peer);
93 }
94
95 /* send the peer id and the shm_fd just after a new client connection */
96 static int
97 ivshmem_server_send_initial_info(IvshmemServer *server, IvshmemServerPeer *peer)
98 {
99 int ret;
100
101 /* send our protocol version first */
102 ret = ivshmem_server_send_one_msg(peer->sock_fd, IVSHMEM_PROTOCOL_VERSION,
103 -1);
104 if (ret < 0) {
105 IVSHMEM_SERVER_DEBUG(server, "cannot send version: %s\n",
106 strerror(errno));
107 return -1;
108 }
109
110 /* send the peer id to the client */
111 ret = ivshmem_server_send_one_msg(peer->sock_fd, peer->id, -1);
112 if (ret < 0) {
113 IVSHMEM_SERVER_DEBUG(server, "cannot send peer id: %s\n",
114 strerror(errno));
115 return -1;
116 }
117
118 /* send the shm_fd */
119 ret = ivshmem_server_send_one_msg(peer->sock_fd, -1, server->shm_fd);
120 if (ret < 0) {
121 IVSHMEM_SERVER_DEBUG(server, "cannot send shm fd: %s\n",
122 strerror(errno));
123 return -1;
124 }
125
126 return 0;
127 }
128
129 /* handle message on listening unix socket (new client connection) */
130 static int
131 ivshmem_server_handle_new_conn(IvshmemServer *server)
132 {
133 IvshmemServerPeer *peer, *other_peer;
134 struct sockaddr_un unaddr;
135 socklen_t unaddr_len;
136 int newfd;
137 unsigned i;
138
139 /* accept the incoming connection */
140 unaddr_len = sizeof(unaddr);
141 newfd = qemu_accept(server->sock_fd,
142 (struct sockaddr *)&unaddr, &unaddr_len);
143
144 if (newfd < 0) {
145 IVSHMEM_SERVER_DEBUG(server, "cannot accept() %s\n", strerror(errno));
146 return -1;
147 }
148
149 qemu_set_nonblock(newfd);
150 IVSHMEM_SERVER_DEBUG(server, "accept()=%d\n", newfd);
151
152 /* allocate new structure for this peer */
153 peer = g_malloc0(sizeof(*peer));
154 peer->sock_fd = newfd;
155
156 /* get an unused peer id */
157 /* XXX: this could use id allocation such as Linux IDA, or simply
158 * a free-list */
159 for (i = 0; i < G_MAXUINT16; i++) {
160 if (ivshmem_server_search_peer(server, server->cur_id) == NULL) {
161 break;
162 }
163 server->cur_id++;
164 }
165 if (i == G_MAXUINT16) {
166 IVSHMEM_SERVER_DEBUG(server, "cannot allocate new client id\n");
167 close(newfd);
168 g_free(peer);
169 return -1;
170 }
171 peer->id = server->cur_id++;
172
173 /* create eventfd, one per vector */
174 peer->vectors_count = server->n_vectors;
175 for (i = 0; i < peer->vectors_count; i++) {
176 if (event_notifier_init(&peer->vectors[i], FALSE) < 0) {
177 IVSHMEM_SERVER_DEBUG(server, "cannot create eventfd\n");
178 goto fail;
179 }
180 }
181
182 /* send peer id and shm fd */
183 if (ivshmem_server_send_initial_info(server, peer) < 0) {
184 IVSHMEM_SERVER_DEBUG(server, "cannot send initial info\n");
185 goto fail;
186 }
187
188 /* advertise the new peer to others */
189 QTAILQ_FOREACH(other_peer, &server->peer_list, next) {
190 for (i = 0; i < peer->vectors_count; i++) {
191 ivshmem_server_send_one_msg(other_peer->sock_fd, peer->id,
192 peer->vectors[i].wfd);
193 }
194 }
195
196 /* advertise the other peers to the new one */
197 QTAILQ_FOREACH(other_peer, &server->peer_list, next) {
198 for (i = 0; i < peer->vectors_count; i++) {
199 ivshmem_server_send_one_msg(peer->sock_fd, other_peer->id,
200 other_peer->vectors[i].wfd);
201 }
202 }
203
204 /* advertise the new peer to itself */
205 for (i = 0; i < peer->vectors_count; i++) {
206 ivshmem_server_send_one_msg(peer->sock_fd, peer->id,
207 event_notifier_get_fd(&peer->vectors[i]));
208 }
209
210 QTAILQ_INSERT_TAIL(&server->peer_list, peer, next);
211 IVSHMEM_SERVER_DEBUG(server, "new peer id = %" PRId64 "\n",
212 peer->id);
213 return 0;
214
215 fail:
216 while (i--) {
217 event_notifier_cleanup(&peer->vectors[i]);
218 }
219 close(newfd);
220 g_free(peer);
221 return -1;
222 }
223
224 /* Try to ftruncate a file to next power of 2 of shmsize.
225 * If it fails; all power of 2 above shmsize are tested until
226 * we reach the maximum huge page size. This is useful
227 * if the shm file is in a hugetlbfs that cannot be truncated to the
228 * shm_size value. */
229 static int
230 ivshmem_server_ftruncate(int fd, unsigned shmsize)
231 {
232 int ret;
233 struct stat mapstat;
234
235 /* align shmsize to next power of 2 */
236 shmsize = pow2ceil(shmsize);
237
238 if (fstat(fd, &mapstat) != -1 && mapstat.st_size == shmsize) {
239 return 0;
240 }
241
242 while (shmsize <= IVSHMEM_SERVER_MAX_HUGEPAGE_SIZE) {
243 ret = ftruncate(fd, shmsize);
244 if (ret == 0) {
245 return ret;
246 }
247 shmsize *= 2;
248 }
249
250 return -1;
251 }
252
253 /* Init a new ivshmem server */
254 int
255 ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path,
256 const char *shm_path, bool use_shm_open,
257 size_t shm_size, unsigned n_vectors,
258 bool verbose)
259 {
260 int ret;
261
262 memset(server, 0, sizeof(*server));
263 server->verbose = verbose;
264
265 ret = snprintf(server->unix_sock_path, sizeof(server->unix_sock_path),
266 "%s", unix_sock_path);
267 if (ret < 0 || ret >= sizeof(server->unix_sock_path)) {
268 IVSHMEM_SERVER_DEBUG(server, "could not copy unix socket path\n");
269 return -1;
270 }
271 ret = snprintf(server->shm_path, sizeof(server->shm_path),
272 "%s", shm_path);
273 if (ret < 0 || ret >= sizeof(server->shm_path)) {
274 IVSHMEM_SERVER_DEBUG(server, "could not copy shm path\n");
275 return -1;
276 }
277
278 server->use_shm_open = use_shm_open;
279 server->shm_size = shm_size;
280 server->n_vectors = n_vectors;
281
282 QTAILQ_INIT(&server->peer_list);
283
284 return 0;
285 }
286
287 /* open shm, create and bind to the unix socket */
288 int
289 ivshmem_server_start(IvshmemServer *server)
290 {
291 struct sockaddr_un sun;
292 int shm_fd, sock_fd, ret;
293
294 /* open shm file */
295 if (server->use_shm_open) {
296 IVSHMEM_SERVER_DEBUG(server, "Using POSIX shared memory: %s\n",
297 server->shm_path);
298 shm_fd = shm_open(server->shm_path, O_CREAT | O_RDWR, S_IRWXU);
299 } else {
300 gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX", server->shm_path);
301 IVSHMEM_SERVER_DEBUG(server, "Using file-backed shared memory: %s\n",
302 server->shm_path);
303 shm_fd = mkstemp(filename);
304 unlink(filename);
305 g_free(filename);
306 }
307
308 if (shm_fd < 0) {
309 fprintf(stderr, "cannot open shm file %s: %s\n", server->shm_path,
310 strerror(errno));
311 return -1;
312 }
313 if (ivshmem_server_ftruncate(shm_fd, server->shm_size) < 0) {
314 fprintf(stderr, "ftruncate(%s) failed: %s\n", server->shm_path,
315 strerror(errno));
316 goto err_close_shm;
317 }
318
319 IVSHMEM_SERVER_DEBUG(server, "create & bind socket %s\n",
320 server->unix_sock_path);
321
322 /* create the unix listening socket */
323 sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
324 if (sock_fd < 0) {
325 IVSHMEM_SERVER_DEBUG(server, "cannot create socket: %s\n",
326 strerror(errno));
327 goto err_close_shm;
328 }
329
330 sun.sun_family = AF_UNIX;
331 ret = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s",
332 server->unix_sock_path);
333 if (ret < 0 || ret >= sizeof(sun.sun_path)) {
334 IVSHMEM_SERVER_DEBUG(server, "could not copy unix socket path\n");
335 goto err_close_sock;
336 }
337 if (bind(sock_fd, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
338 IVSHMEM_SERVER_DEBUG(server, "cannot connect to %s: %s\n", sun.sun_path,
339 strerror(errno));
340 goto err_close_sock;
341 }
342
343 if (listen(sock_fd, IVSHMEM_SERVER_LISTEN_BACKLOG) < 0) {
344 IVSHMEM_SERVER_DEBUG(server, "listen() failed: %s\n", strerror(errno));
345 goto err_close_sock;
346 }
347
348 server->sock_fd = sock_fd;
349 server->shm_fd = shm_fd;
350
351 return 0;
352
353 err_close_sock:
354 close(sock_fd);
355 err_close_shm:
356 if (server->use_shm_open) {
357 shm_unlink(server->shm_path);
358 }
359 close(shm_fd);
360 return -1;
361 }
362
363 /* close connections to clients, the unix socket and the shm fd */
364 void
365 ivshmem_server_close(IvshmemServer *server)
366 {
367 IvshmemServerPeer *peer, *npeer;
368
369 IVSHMEM_SERVER_DEBUG(server, "close server\n");
370
371 QTAILQ_FOREACH_SAFE(peer, &server->peer_list, next, npeer) {
372 ivshmem_server_free_peer(server, peer);
373 }
374
375 unlink(server->unix_sock_path);
376 if (server->use_shm_open) {
377 shm_unlink(server->shm_path);
378 }
379 close(server->sock_fd);
380 close(server->shm_fd);
381 server->sock_fd = -1;
382 server->shm_fd = -1;
383 }
384
385 /* get the fd_set according to the unix socket and the peer list */
386 void
387 ivshmem_server_get_fds(const IvshmemServer *server, fd_set *fds, int *maxfd)
388 {
389 IvshmemServerPeer *peer;
390
391 if (server->sock_fd == -1) {
392 return;
393 }
394
395 FD_SET(server->sock_fd, fds);
396 if (server->sock_fd >= *maxfd) {
397 *maxfd = server->sock_fd + 1;
398 }
399
400 QTAILQ_FOREACH(peer, &server->peer_list, next) {
401 FD_SET(peer->sock_fd, fds);
402 if (peer->sock_fd >= *maxfd) {
403 *maxfd = peer->sock_fd + 1;
404 }
405 }
406 }
407
408 /* process incoming messages on the sockets in fd_set */
409 int
410 ivshmem_server_handle_fds(IvshmemServer *server, fd_set *fds, int maxfd)
411 {
412 IvshmemServerPeer *peer, *peer_next;
413
414 if (server->sock_fd < maxfd && FD_ISSET(server->sock_fd, fds) &&
415 ivshmem_server_handle_new_conn(server) < 0 && errno != EINTR) {
416 IVSHMEM_SERVER_DEBUG(server, "ivshmem_server_handle_new_conn() "
417 "failed\n");
418 return -1;
419 }
420
421 QTAILQ_FOREACH_SAFE(peer, &server->peer_list, next, peer_next) {
422 /* any message from a peer socket result in a close() */
423 IVSHMEM_SERVER_DEBUG(server, "peer->sock_fd=%d\n", peer->sock_fd);
424 if (peer->sock_fd < maxfd && FD_ISSET(peer->sock_fd, fds)) {
425 ivshmem_server_free_peer(server, peer);
426 }
427 }
428
429 return 0;
430 }
431
432 /* lookup peer from its id */
433 IvshmemServerPeer *
434 ivshmem_server_search_peer(IvshmemServer *server, int64_t peer_id)
435 {
436 IvshmemServerPeer *peer;
437
438 QTAILQ_FOREACH(peer, &server->peer_list, next) {
439 if (peer->id == peer_id) {
440 return peer;
441 }
442 }
443 return NULL;
444 }
445
446 /* dump our info, the list of peers their vectors on stdout */
447 void
448 ivshmem_server_dump(const IvshmemServer *server)
449 {
450 const IvshmemServerPeer *peer;
451 unsigned vector;
452
453 /* dump peers */
454 QTAILQ_FOREACH(peer, &server->peer_list, next) {
455 printf("peer_id = %" PRId64 "\n", peer->id);
456
457 for (vector = 0; vector < peer->vectors_count; vector++) {
458 printf(" vector %d is enabled (fd=%d)\n", vector,
459 event_notifier_get_fd(&peer->vectors[vector]));
460 }
461 }
462 }