vhost_user.c revision 809f0800
1/*-
2 *   BSD LICENSE
3 *
4 *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
5 *   All rights reserved.
6 *
7 *   Redistribution and use in source and binary forms, with or without
8 *   modification, are permitted provided that the following conditions
9 *   are met:
10 *
11 *     * Redistributions of source code must retain the above copyright
12 *       notice, this list of conditions and the following disclaimer.
13 *     * Redistributions in binary form must reproduce the above copyright
14 *       notice, this list of conditions and the following disclaimer in
15 *       the documentation and/or other materials provided with the
16 *       distribution.
17 *     * Neither the name of Intel Corporation nor the names of its
18 *       contributors may be used to endorse or promote products derived
19 *       from this software without specific prior written permission.
20 *
21 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/socket.h>
35#include <sys/types.h>
36#include <sys/stat.h>
37#include <unistd.h>
38#include <fcntl.h>
39#include <sys/un.h>
40#include <string.h>
41#include <errno.h>
42
43#include "vhost.h"
44
45static int
46vhost_user_write(int fd, void *buf, int len, int *fds, int fd_num)
47{
48	int r;
49	struct msghdr msgh;
50	struct iovec iov;
51	size_t fd_size = fd_num * sizeof(int);
52	char control[CMSG_SPACE(fd_size)];
53	struct cmsghdr *cmsg;
54
55	memset(&msgh, 0, sizeof(msgh));
56	memset(control, 0, sizeof(control));
57
58	iov.iov_base = (uint8_t *)buf;
59	iov.iov_len = len;
60
61	msgh.msg_iov = &iov;
62	msgh.msg_iovlen = 1;
63	msgh.msg_control = control;
64	msgh.msg_controllen = sizeof(control);
65
66	cmsg = CMSG_FIRSTHDR(&msgh);
67	cmsg->cmsg_len = CMSG_LEN(fd_size);
68	cmsg->cmsg_level = SOL_SOCKET;
69	cmsg->cmsg_type = SCM_RIGHTS;
70	memcpy(CMSG_DATA(cmsg), fds, fd_size);
71
72	do {
73		r = sendmsg(fd, &msgh, 0);
74	} while (r < 0 && errno == EINTR);
75
76	return r;
77}
78
79static int
80vhost_user_read(int fd, struct vhost_user_msg *msg)
81{
82	uint32_t valid_flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
83	int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
84
85	ret = recv(fd, (void *)msg, sz_hdr, 0);
86	if (ret < sz_hdr) {
87		PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
88			    ret, sz_hdr);
89		goto fail;
90	}
91
92	/* validate msg flags */
93	if (msg->flags != (valid_flags)) {
94		PMD_DRV_LOG(ERR, "Failed to recv msg: flags %x instead of %x.",
95			    msg->flags, valid_flags);
96		goto fail;
97	}
98
99	sz_payload = msg->size;
100	if (sz_payload) {
101		ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
102		if (ret < sz_payload) {
103			PMD_DRV_LOG(ERR,
104				"Failed to recv msg payload: %d instead of %d.",
105				ret, msg->size);
106			goto fail;
107		}
108	}
109
110	return 0;
111
112fail:
113	return -1;
114}
115
116struct hugepage_file_info {
117	uint64_t addr;            /**< virtual addr */
118	size_t   size;            /**< the file size */
119	char     path[PATH_MAX];  /**< path to backing file */
120};
121
122/* Two possible options:
123 * 1. Match HUGEPAGE_INFO_FMT to find the file storing struct hugepage_file
124 * array. This is simple but cannot be used in secondary process because
125 * secondary process will close and munmap that file.
126 * 2. Match HUGEFILE_FMT to find hugepage files directly.
127 *
128 * We choose option 2.
129 */
130static int
131get_hugepage_file_info(struct hugepage_file_info huges[], int max)
132{
133	int idx;
134	FILE *f;
135	char buf[BUFSIZ], *tmp, *tail;
136	char *str_underline, *str_start;
137	int huge_index;
138	uint64_t v_start, v_end;
139
140	f = fopen("/proc/self/maps", "r");
141	if (!f) {
142		PMD_DRV_LOG(ERR, "cannot open /proc/self/maps");
143		return -1;
144	}
145
146	idx = 0;
147	while (fgets(buf, sizeof(buf), f) != NULL) {
148		if (sscanf(buf, "%" PRIx64 "-%" PRIx64, &v_start, &v_end) < 2) {
149			PMD_DRV_LOG(ERR, "Failed to parse address");
150			goto error;
151		}
152
153		tmp = strchr(buf, ' ') + 1; /** skip address */
154		tmp = strchr(tmp, ' ') + 1; /** skip perm */
155		tmp = strchr(tmp, ' ') + 1; /** skip offset */
156		tmp = strchr(tmp, ' ') + 1; /** skip dev */
157		tmp = strchr(tmp, ' ') + 1; /** skip inode */
158		while (*tmp == ' ')         /** skip spaces */
159			tmp++;
160		tail = strrchr(tmp, '\n');  /** remove newline if exists */
161		if (tail)
162			*tail = '\0';
163
164		/* Match HUGEFILE_FMT, aka "%s/%smap_%d",
165		 * which is defined in eal_filesystem.h
166		 */
167		str_underline = strrchr(tmp, '_');
168		if (!str_underline)
169			continue;
170
171		str_start = str_underline - strlen("map");
172		if (str_start < tmp)
173			continue;
174
175		if (sscanf(str_start, "map_%d", &huge_index) != 1)
176			continue;
177
178		if (idx >= max) {
179			PMD_DRV_LOG(ERR, "Exceed maximum of %d", max);
180			goto error;
181		}
182		huges[idx].addr = v_start;
183		huges[idx].size = v_end - v_start;
184		strcpy(huges[idx].path, tmp);
185		idx++;
186	}
187
188	fclose(f);
189	return idx;
190
191error:
192	fclose(f);
193	return -1;
194}
195
196static int
197prepare_vhost_memory_user(struct vhost_user_msg *msg, int fds[])
198{
199	int i, num;
200	struct hugepage_file_info huges[VHOST_MEMORY_MAX_NREGIONS];
201	struct vhost_memory_region *mr;
202
203	num = get_hugepage_file_info(huges, VHOST_MEMORY_MAX_NREGIONS);
204	if (num < 0) {
205		PMD_INIT_LOG(ERR, "Failed to prepare memory for vhost-user");
206		return -1;
207	}
208
209	for (i = 0; i < num; ++i) {
210		mr = &msg->payload.memory.regions[i];
211		mr->guest_phys_addr = huges[i].addr; /* use vaddr! */
212		mr->userspace_addr = huges[i].addr;
213		mr->memory_size = huges[i].size;
214		mr->mmap_offset = 0;
215		fds[i] = open(huges[i].path, O_RDWR);
216	}
217
218	msg->payload.memory.nregions = num;
219	msg->payload.memory.padding = 0;
220
221	return 0;
222}
223
224static struct vhost_user_msg m;
225
226static const char * const vhost_msg_strings[] = {
227	[VHOST_USER_SET_OWNER] = "VHOST_USER_SET_OWNER",
228	[VHOST_USER_RESET_OWNER] = "VHOST_USER_RESET_OWNER",
229	[VHOST_USER_SET_FEATURES] = "VHOST_USER_SET_FEATURES",
230	[VHOST_USER_GET_FEATURES] = "VHOST_USER_GET_FEATURES",
231	[VHOST_USER_SET_VRING_CALL] = "VHOST_USER_SET_VRING_CALL",
232	[VHOST_USER_SET_VRING_NUM] = "VHOST_USER_SET_VRING_NUM",
233	[VHOST_USER_SET_VRING_BASE] = "VHOST_USER_SET_VRING_BASE",
234	[VHOST_USER_GET_VRING_BASE] = "VHOST_USER_GET_VRING_BASE",
235	[VHOST_USER_SET_VRING_ADDR] = "VHOST_USER_SET_VRING_ADDR",
236	[VHOST_USER_SET_VRING_KICK] = "VHOST_USER_SET_VRING_KICK",
237	[VHOST_USER_SET_MEM_TABLE] = "VHOST_USER_SET_MEM_TABLE",
238	[VHOST_USER_SET_VRING_ENABLE] = "VHOST_USER_SET_VRING_ENABLE",
239	NULL,
240};
241
242int
243vhost_user_sock(int vhostfd, enum vhost_user_request req, void *arg)
244{
245	struct vhost_user_msg msg;
246	struct vhost_vring_file *file = 0;
247	int need_reply = 0;
248	int fds[VHOST_MEMORY_MAX_NREGIONS];
249	int fd_num = 0;
250	int i, len;
251
252	RTE_SET_USED(m);
253	RTE_SET_USED(vhost_msg_strings);
254
255	PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
256
257	msg.request = req;
258	msg.flags = VHOST_USER_VERSION;
259	msg.size = 0;
260
261	switch (req) {
262	case VHOST_USER_GET_FEATURES:
263		need_reply = 1;
264		break;
265
266	case VHOST_USER_SET_FEATURES:
267	case VHOST_USER_SET_LOG_BASE:
268		msg.payload.u64 = *((__u64 *)arg);
269		msg.size = sizeof(m.payload.u64);
270		break;
271
272	case VHOST_USER_SET_OWNER:
273	case VHOST_USER_RESET_OWNER:
274		break;
275
276	case VHOST_USER_SET_MEM_TABLE:
277		if (prepare_vhost_memory_user(&msg, fds) < 0)
278			return -1;
279		fd_num = msg.payload.memory.nregions;
280		msg.size = sizeof(m.payload.memory.nregions);
281		msg.size += sizeof(m.payload.memory.padding);
282		msg.size += fd_num * sizeof(struct vhost_memory_region);
283		break;
284
285	case VHOST_USER_SET_LOG_FD:
286		fds[fd_num++] = *((int *)arg);
287		break;
288
289	case VHOST_USER_SET_VRING_NUM:
290	case VHOST_USER_SET_VRING_BASE:
291	case VHOST_USER_SET_VRING_ENABLE:
292		memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
293		msg.size = sizeof(m.payload.state);
294		break;
295
296	case VHOST_USER_GET_VRING_BASE:
297		memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
298		msg.size = sizeof(m.payload.state);
299		need_reply = 1;
300		break;
301
302	case VHOST_USER_SET_VRING_ADDR:
303		memcpy(&msg.payload.addr, arg, sizeof(msg.payload.addr));
304		msg.size = sizeof(m.payload.addr);
305		break;
306
307	case VHOST_USER_SET_VRING_KICK:
308	case VHOST_USER_SET_VRING_CALL:
309	case VHOST_USER_SET_VRING_ERR:
310		file = arg;
311		msg.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK;
312		msg.size = sizeof(m.payload.u64);
313		if (file->fd > 0)
314			fds[fd_num++] = file->fd;
315		else
316			msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
317		break;
318
319	default:
320		PMD_DRV_LOG(ERR, "trying to send unhandled msg type");
321		return -1;
322	}
323
324	len = VHOST_USER_HDR_SIZE + msg.size;
325	if (vhost_user_write(vhostfd, &msg, len, fds, fd_num) < 0) {
326		PMD_DRV_LOG(ERR, "%s failed: %s",
327			    vhost_msg_strings[req], strerror(errno));
328		return -1;
329	}
330
331	if (req == VHOST_USER_SET_MEM_TABLE)
332		for (i = 0; i < fd_num; ++i)
333			close(fds[i]);
334
335	if (need_reply) {
336		if (vhost_user_read(vhostfd, &msg) < 0) {
337			PMD_DRV_LOG(ERR, "Received msg failed: %s",
338				    strerror(errno));
339			return -1;
340		}
341
342		if (req != msg.request) {
343			PMD_DRV_LOG(ERR, "Received unexpected msg type");
344			return -1;
345		}
346
347		switch (req) {
348		case VHOST_USER_GET_FEATURES:
349			if (msg.size != sizeof(m.payload.u64)) {
350				PMD_DRV_LOG(ERR, "Received bad msg size");
351				return -1;
352			}
353			*((__u64 *)arg) = msg.payload.u64;
354			break;
355		case VHOST_USER_GET_VRING_BASE:
356			if (msg.size != sizeof(m.payload.state)) {
357				PMD_DRV_LOG(ERR, "Received bad msg size");
358				return -1;
359			}
360			memcpy(arg, &msg.payload.state,
361			       sizeof(struct vhost_vring_state));
362			break;
363		default:
364			PMD_DRV_LOG(ERR, "Received unexpected msg type");
365			return -1;
366		}
367	}
368
369	return 0;
370}
371
372/**
373 * Set up environment to talk with a vhost user backend.
374 * @param path
375 *   - The path to vhost user unix socket file.
376 *
377 * @return
378 *   - (-1) if fail to set up;
379 *   - (>=0) if successful, and it is the fd to vhostfd.
380 */
381int
382vhost_user_setup(const char *path)
383{
384	int fd;
385	int flag;
386	struct sockaddr_un un;
387
388	fd = socket(AF_UNIX, SOCK_STREAM, 0);
389	if (fd < 0) {
390		PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
391		return -1;
392	}
393
394	flag = fcntl(fd, F_GETFD);
395	fcntl(fd, F_SETFD, flag | FD_CLOEXEC);
396
397	memset(&un, 0, sizeof(un));
398	un.sun_family = AF_UNIX;
399	snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
400	if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
401		PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
402		close(fd);
403		return -1;
404	}
405
406	return fd;
407}
408
409int
410vhost_user_enable_queue_pair(int vhostfd, uint16_t pair_idx, int enable)
411{
412	int i;
413
414	for (i = 0; i < 2; ++i) {
415		struct vhost_vring_state state = {
416			.index = pair_idx * 2 + i,
417			.num   = enable,
418		};
419
420		if (vhost_user_sock(vhostfd,
421				    VHOST_USER_SET_VRING_ENABLE, &state))
422			return -1;
423	}
424
425	return 0;
426}
427