lib/power/guest_channel.c

   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
  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
  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
 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
 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
 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
 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
 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 }