1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
3 */
4
5 #include <glob.h>
6 #include <stdio.h>
7 #include <unistd.h>
8 #include <limits.h>
9 #include <fcntl.h>
10 #include <string.h>
11 #include <errno.h>
12 #include <poll.h>
13
14
15 #include <rte_log.h>
16 #include <rte_power.h>
17
18 #include "guest_channel.h"
19
20 #define RTE_LOGTYPE_GUEST_CHANNEL RTE_LOGTYPE_USER1
21
22 /* Timeout for incoming message in milliseconds. */
23 #define TIMEOUT 10
24
25 static int global_fds[RTE_MAX_LCORE] = { [0 ... RTE_MAX_LCORE-1] = -1 };
26
27 int
guest_channel_host_check_exists(const char * path)28 guest_channel_host_check_exists(const char *path)
29 {
30 char glob_path[PATH_MAX];
31 glob_t g;
32 int ret;
33
34 /* we cannot know in advance which cores have VM channels, so glob */
35 snprintf(glob_path, PATH_MAX, "%s.*", path);
36
37 ret = glob(glob_path, GLOB_NOSORT, NULL, &g);
38 if (ret != 0) {
39 /* couldn't read anything */
40 ret = 0;
41 goto out;
42 }
43
44 /* do we have at least one match? */
45 ret = g.gl_pathc > 0;
46
47 out:
48 globfree(&g);
49 return ret;
50 }
51
52 int
guest_channel_host_connect(const char * path,unsigned int lcore_id)53 guest_channel_host_connect(const char *path, unsigned int lcore_id)
54 {
55 int flags, ret;
56 struct rte_power_channel_packet pkt;
57 char fd_path[PATH_MAX];
58 int fd = -1;
59
60 if (lcore_id >= RTE_MAX_LCORE) {
61 RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is out of range 0...%d\n",
62 lcore_id, RTE_MAX_LCORE-1);
63 return -1;
64 }
65 /* check if path is already open */
66 if (global_fds[lcore_id] != -1) {
67 RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is already open with fd %d\n",
68 lcore_id, global_fds[lcore_id]);
69 return -1;
70 }
71
72 snprintf(fd_path, PATH_MAX, "%s.%u", path, lcore_id);
73 RTE_LOG(INFO, GUEST_CHANNEL, "Opening channel '%s' for lcore %u\n",
74 fd_path, lcore_id);
75 fd = open(fd_path, O_RDWR);
76 if (fd < 0) {
77 RTE_LOG(ERR, GUEST_CHANNEL, "Unable to to connect to '%s' with error "
78 "%s\n", fd_path, strerror(errno));
79 return -1;
80 }
81
82 flags = fcntl(fd, F_GETFL, 0);
83 if (flags < 0) {
84 RTE_LOG(ERR, GUEST_CHANNEL, "Failed on fcntl get flags for file %s\n",
85 fd_path);
86 goto error;
87 }
88
89 flags |= O_NONBLOCK;
90 if (fcntl(fd, F_SETFL, flags) < 0) {
91 RTE_LOG(ERR, GUEST_CHANNEL, "Failed on setting non-blocking mode for "
92 "file %s", fd_path);
93 goto error;
94 }
95 /* QEMU needs a delay after connection */
96 sleep(1);
97
98 /* Send a test packet, this command is ignored by the host, but a successful
99 * send indicates that the host endpoint is monitoring.
100 */
101 pkt.command = RTE_POWER_CPU_POWER_CONNECT;
102 global_fds[lcore_id] = fd;
103 ret = guest_channel_send_msg(&pkt, lcore_id);
104 if (ret != 0) {
105 RTE_LOG(ERR, GUEST_CHANNEL,
106 "Error on channel '%s' communications test: %s\n",
107 fd_path, ret > 0 ? strerror(ret) :
108 "channel not connected");
109 goto error;
110 }
111 RTE_LOG(INFO, GUEST_CHANNEL, "Channel '%s' is now connected\n", fd_path);
112 return 0;
113 error:
114 close(fd);
115 global_fds[lcore_id] = -1;
116 return -1;
117 }
118
119 int
guest_channel_send_msg(struct rte_power_channel_packet * pkt,unsigned int lcore_id)120 guest_channel_send_msg(struct rte_power_channel_packet *pkt,
121 unsigned int lcore_id)
122 {
123 int ret, buffer_len = sizeof(*pkt);
124 void *buffer = pkt;
125
126 if (lcore_id >= RTE_MAX_LCORE) {
127 RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is out of range 0...%d\n",
128 lcore_id, RTE_MAX_LCORE-1);
129 return -1;
130 }
131
132 if (global_fds[lcore_id] < 0) {
133 RTE_LOG(ERR, GUEST_CHANNEL, "Channel is not connected\n");
134 return -1;
135 }
136 while (buffer_len > 0) {
137 ret = write(global_fds[lcore_id], buffer, buffer_len);
138 if (ret == buffer_len)
139 return 0;
140 if (ret == -1) {
141 if (errno == EINTR)
142 continue;
143 return errno;
144 }
145 buffer = (char *)buffer + ret;
146 buffer_len -= ret;
147 }
148 return 0;
149 }
150
rte_power_guest_channel_send_msg(struct rte_power_channel_packet * pkt,unsigned int lcore_id)151 int rte_power_guest_channel_send_msg(struct rte_power_channel_packet *pkt,
152 unsigned int lcore_id)
153 {
154 return guest_channel_send_msg(pkt, lcore_id);
155 }
156
power_guest_channel_read_msg(void * pkt,size_t pkt_len,unsigned int lcore_id)157 int power_guest_channel_read_msg(void *pkt,
158 size_t pkt_len,
159 unsigned int lcore_id)
160 {
161 int ret;
162 struct pollfd fds;
163
164 if (pkt_len == 0 || pkt == NULL)
165 return -1;
166
167 if (lcore_id >= RTE_MAX_LCORE) {
168 RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is out of range 0...%d\n",
169 lcore_id, RTE_MAX_LCORE-1);
170 return -1;
171 }
172
173 if (global_fds[lcore_id] < 0) {
174 RTE_LOG(ERR, GUEST_CHANNEL, "Channel is not connected\n");
175 return -1;
176 }
177
178 fds.fd = global_fds[lcore_id];
179 fds.events = POLLIN;
180
181 ret = poll(&fds, 1, TIMEOUT);
182 if (ret == 0) {
183 RTE_LOG(DEBUG, GUEST_CHANNEL, "Timeout occurred during poll function.\n");
184 return -1;
185 } else if (ret < 0) {
186 RTE_LOG(ERR, GUEST_CHANNEL, "Error occurred during poll function: %s\n",
187 strerror(errno));
188 return -1;
189 }
190
191 while (pkt_len > 0) {
192 ret = read(global_fds[lcore_id],
193 pkt, pkt_len);
194
195 if (ret < 0) {
196 if (errno == EINTR)
197 continue;
198 return -1;
199 }
200
201 if (ret == 0) {
202 RTE_LOG(ERR, GUEST_CHANNEL, "Expected more data, but connection has been closed.\n");
203 return -1;
204 }
205 pkt = (char *)pkt + ret;
206 pkt_len -= ret;
207 }
208
209 return 0;
210 }
211
rte_power_guest_channel_receive_msg(void * pkt,size_t pkt_len,unsigned int lcore_id)212 int rte_power_guest_channel_receive_msg(void *pkt,
213 size_t pkt_len,
214 unsigned int lcore_id)
215 {
216 return power_guest_channel_read_msg(pkt, pkt_len, lcore_id);
217 }
218
219 void
guest_channel_host_disconnect(unsigned int lcore_id)220 guest_channel_host_disconnect(unsigned int lcore_id)
221 {
222 if (lcore_id >= RTE_MAX_LCORE) {
223 RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is out of range 0...%d\n",
224 lcore_id, RTE_MAX_LCORE-1);
225 return;
226 }
227 if (global_fds[lcore_id] < 0)
228 return;
229 close(global_fds[lcore_id]);
230 global_fds[lcore_id] = -1;
231 }
232