drivers/net/virtio/virtio_user/vhost_user.c

   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
  45 static int
  46 vhost_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
  79 static int
  80 vhost_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
 101         if ((size_t)sz_payload > sizeof(msg->payload))
 102                 goto fail;
 103
 104         if (sz_payload) {
 105                 ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
 106                 if (ret < sz_payload) {
 107                         PMD_DRV_LOG(ERR,
 108                                 "Failed to recv msg payload: %d instead of %d.",
 109                                 ret, msg->size);
 110                         goto fail;
 111                 }
 112         }
 113
 114         return 0;
 115
 116 fail:
 117         return -1;
 118 }
 119
 120 struct hugepage_file_info {
 121         uint64_t addr;            /**< virtual addr */
 122         size_t   size;            /**< the file size */
 123         char     path[PATH_MAX];  /**< path to backing file */
 124 };
 125
 126 /* Two possible options:
 127  * 1. Match HUGEPAGE_INFO_FMT to find the file storing struct hugepage_file
 128  * array. This is simple but cannot be used in secondary process because
 129  * secondary process will close and munmap that file.
 130  * 2. Match HUGEFILE_FMT to find hugepage files directly.
 131  *
 132  * We choose option 2.
 133  */
 134 static int
 135 get_hugepage_file_info(struct hugepage_file_info huges[], int max)
 136 {
 137         int idx;
 138         FILE *f;
 139         char buf[BUFSIZ], *tmp, *tail;
 140         char *str_underline, *str_start;
 141         int huge_index;
 142         uint64_t v_start, v_end;
 143
 144         f = fopen("/proc/self/maps", "r");
 145         if (!f) {
 146                 PMD_DRV_LOG(ERR, "cannot open /proc/self/maps");
 147                 return -1;
 148         }
 149
 150         idx = 0;
 151         while (fgets(buf, sizeof(buf), f) != NULL) {
 152                 if (sscanf(buf, "%" PRIx64 "-%" PRIx64, &v_start, &v_end) < 2) {
 153                         PMD_DRV_LOG(ERR, "Failed to parse address");
 154                         goto error;
 155                 }
 156
 157                 tmp = strchr(buf, ' ') + 1; /** skip address */
 158                 tmp = strchr(tmp, ' ') + 1; /** skip perm */
 159                 tmp = strchr(tmp, ' ') + 1; /** skip offset */
 160                 tmp = strchr(tmp, ' ') + 1; /** skip dev */
 161                 tmp = strchr(tmp, ' ') + 1; /** skip inode */
 162                 while (*tmp == ' ')         /** skip spaces */
 163                         tmp++;
 164                 tail = strrchr(tmp, '\n');  /** remove newline if exists */
 165                 if (tail)
 166                         *tail = '\0';
 167
 168                 /* Match HUGEFILE_FMT, aka "%s/%smap_%d",
 169                  * which is defined in eal_filesystem.h
 170                  */
 171                 str_underline = strrchr(tmp, '_');
 172                 if (!str_underline)
 173                         continue;
 174
 175                 str_start = str_underline - strlen("map");
 176                 if (str_start < tmp)
 177                         continue;
 178
 179                 if (sscanf(str_start, "map_%d", &huge_index) != 1)
 180                         continue;
 181
 182                 if (idx >= max) {
 183                         PMD_DRV_LOG(ERR, "Exceed maximum of %d", max);
 184                         goto error;
 185                 }
 186                 huges[idx].addr = v_start;
 187                 huges[idx].size = v_end - v_start;
 188                 snprintf(huges[idx].path, PATH_MAX, "%s", tmp);
 189                 idx++;
 190         }
 191
 192         fclose(f);
 193         return idx;
 194
 195 error:
 196         fclose(f);
 197         return -1;
 198 }
 199
 200 static int
 201 prepare_vhost_memory_user(struct vhost_user_msg *msg, int fds[])
 202 {
 203         int i, num;
 204         struct hugepage_file_info huges[VHOST_MEMORY_MAX_NREGIONS];
 205         struct vhost_memory_region *mr;
 206
 207         num = get_hugepage_file_info(huges, VHOST_MEMORY_MAX_NREGIONS);
 208         if (num < 0) {
 209                 PMD_INIT_LOG(ERR, "Failed to prepare memory for vhost-user");
 210                 return -1;
 211         }
 212
 213         for (i = 0; i < num; ++i) {
 214                 mr = &msg->payload.memory.regions[i];
 215                 mr->guest_phys_addr = huges[i].addr; /* use vaddr! */
 216                 mr->userspace_addr = huges[i].addr;
 217                 mr->memory_size = huges[i].size;
 218                 mr->mmap_offset = 0;
 219                 fds[i] = open(huges[i].path, O_RDWR);
 220         }
 221
 222         msg->payload.memory.nregions = num;
 223         msg->payload.memory.padding = 0;
 224
 225         return 0;
 226 }
 227
 228 static struct vhost_user_msg m;
 229
 230 static const char * const vhost_msg_strings[] = {
 231         [VHOST_USER_SET_OWNER] = "VHOST_USER_SET_OWNER",
 232         [VHOST_USER_RESET_OWNER] = "VHOST_USER_RESET_OWNER",
 233         [VHOST_USER_SET_FEATURES] = "VHOST_USER_SET_FEATURES",
 234         [VHOST_USER_GET_FEATURES] = "VHOST_USER_GET_FEATURES",
 235         [VHOST_USER_SET_VRING_CALL] = "VHOST_USER_SET_VRING_CALL",
 236         [VHOST_USER_SET_VRING_NUM] = "VHOST_USER_SET_VRING_NUM",
 237         [VHOST_USER_SET_VRING_BASE] = "VHOST_USER_SET_VRING_BASE",
 238         [VHOST_USER_GET_VRING_BASE] = "VHOST_USER_GET_VRING_BASE",
 239         [VHOST_USER_SET_VRING_ADDR] = "VHOST_USER_SET_VRING_ADDR",
 240         [VHOST_USER_SET_VRING_KICK] = "VHOST_USER_SET_VRING_KICK",
 241         [VHOST_USER_SET_MEM_TABLE] = "VHOST_USER_SET_MEM_TABLE",
 242         [VHOST_USER_SET_VRING_ENABLE] = "VHOST_USER_SET_VRING_ENABLE",
 243         NULL,
 244 };
 245
 246 int
 247 vhost_user_sock(int vhostfd, enum vhost_user_request req, void *arg)
 248 {
 249         struct vhost_user_msg msg;
 250         struct vhost_vring_file *file = 0;
 251         int need_reply = 0;
 252         int fds[VHOST_MEMORY_MAX_NREGIONS];
 253         int fd_num = 0;
 254         int i, len;
 255
 256         RTE_SET_USED(m);
 257         RTE_SET_USED(vhost_msg_strings);
 258
 259         PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
 260
 261         msg.request = req;
 262         msg.flags = VHOST_USER_VERSION;
 263         msg.size = 0;
 264
 265         switch (req) {
 266         case VHOST_USER_GET_FEATURES:
 267                 need_reply = 1;
 268                 break;
 269
 270         case VHOST_USER_SET_FEATURES:
 271         case VHOST_USER_SET_LOG_BASE:
 272                 msg.payload.u64 = *((__u64 *)arg);
 273                 msg.size = sizeof(m.payload.u64);
 274                 break;
 275
 276         case VHOST_USER_SET_OWNER:
 277         case VHOST_USER_RESET_OWNER:
 278                 break;
 279
 280         case VHOST_USER_SET_MEM_TABLE:
 281                 if (prepare_vhost_memory_user(&msg, fds) < 0)
 282                         return -1;
 283                 fd_num = msg.payload.memory.nregions;
 284                 msg.size = sizeof(m.payload.memory.nregions);
 285                 msg.size += sizeof(m.payload.memory.padding);
 286                 msg.size += fd_num * sizeof(struct vhost_memory_region);
 287                 break;
 288
 289         case VHOST_USER_SET_LOG_FD:
 290                 fds[fd_num++] = *((int *)arg);
 291                 break;
 292
 293         case VHOST_USER_SET_VRING_NUM:
 294         case VHOST_USER_SET_VRING_BASE:
 295         case VHOST_USER_SET_VRING_ENABLE:
 296                 memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
 297                 msg.size = sizeof(m.payload.state);
 298                 break;
 299
 300         case VHOST_USER_GET_VRING_BASE:
 301                 memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
 302                 msg.size = sizeof(m.payload.state);
 303                 need_reply = 1;
 304                 break;
 305
 306         case VHOST_USER_SET_VRING_ADDR:
 307                 memcpy(&msg.payload.addr, arg, sizeof(msg.payload.addr));
 308                 msg.size = sizeof(m.payload.addr);
 309                 break;
 310
 311         case VHOST_USER_SET_VRING_KICK:
 312         case VHOST_USER_SET_VRING_CALL:
 313         case VHOST_USER_SET_VRING_ERR:
 314                 file = arg;
 315                 msg.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK;
 316                 msg.size = sizeof(m.payload.u64);
 317                 if (file->fd > 0)
 318                         fds[fd_num++] = file->fd;
 319                 else
 320                         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
 321                 break;
 322
 323         default:
 324                 PMD_DRV_LOG(ERR, "trying to send unhandled msg type");
 325                 return -1;
 326         }
 327
 328         len = VHOST_USER_HDR_SIZE + msg.size;
 329         if (vhost_user_write(vhostfd, &msg, len, fds, fd_num) < 0) {
 330                 PMD_DRV_LOG(ERR, "%s failed: %s",
 331                             vhost_msg_strings[req], strerror(errno));
 332                 return -1;
 333         }
 334
 335         if (req == VHOST_USER_SET_MEM_TABLE)
 336                 for (i = 0; i < fd_num; ++i)
 337                         close(fds[i]);
 338
 339         if (need_reply) {
 340                 if (vhost_user_read(vhostfd, &msg) < 0) {
 341                         PMD_DRV_LOG(ERR, "Received msg failed: %s",
 342                                     strerror(errno));
 343                         return -1;
 344                 }
 345
 346                 if (req != msg.request) {
 347                         PMD_DRV_LOG(ERR, "Received unexpected msg type");
 348                         return -1;
 349                 }
 350
 351                 switch (req) {
 352                 case VHOST_USER_GET_FEATURES:
 353                         if (msg.size != sizeof(m.payload.u64)) {
 354                                 PMD_DRV_LOG(ERR, "Received bad msg size");
 355                                 return -1;
 356                         }
 357                         *((__u64 *)arg) = msg.payload.u64;
 358                         break;
 359                 case VHOST_USER_GET_VRING_BASE:
 360                         if (msg.size != sizeof(m.payload.state)) {
 361                                 PMD_DRV_LOG(ERR, "Received bad msg size");
 362                                 return -1;
 363                         }
 364                         memcpy(arg, &msg.payload.state,
 365                                sizeof(struct vhost_vring_state));
 366                         break;
 367                 default:
 368                         PMD_DRV_LOG(ERR, "Received unexpected msg type");
 369                         return -1;
 370                 }
 371         }
 372
 373         return 0;
 374 }
 375
 376 /**
 377  * Set up environment to talk with a vhost user backend.
 378  * @param path
 379  *   - The path to vhost user unix socket file.
 380  *
 381  * @return
 382  *   - (-1) if fail to set up;
 383  *   - (>=0) if successful, and it is the fd to vhostfd.
 384  */
 385 int
 386 vhost_user_setup(const char *path)
 387 {
 388         int fd;
 389         int flag;
 390         struct sockaddr_un un;
 391
 392         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 393         if (fd < 0) {
 394                 PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
 395                 return -1;
 396         }
 397
 398         flag = fcntl(fd, F_GETFD);
 399         if (fcntl(fd, F_SETFD, flag | FD_CLOEXEC) < 0)
 400                 PMD_DRV_LOG(WARNING, "fcntl failed, %s", strerror(errno));
 401
 402         memset(&un, 0, sizeof(un));
 403         un.sun_family = AF_UNIX;
 404         snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
 405         if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
 406                 PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
 407                 close(fd);
 408                 return -1;
 409         }
 410
 411         return fd;
 412 }
 413
 414 int
 415 vhost_user_enable_queue_pair(int vhostfd, uint16_t pair_idx, int enable)
 416 {
 417         int i;
 418
 419         for (i = 0; i < 2; ++i) {
 420                 struct vhost_vring_state state = {
 421                         .index = pair_idx * 2 + i,
 422                         .num   = enable,
 423                 };
 424
 425                 if (vhost_user_sock(vhostfd,
 426                                     VHOST_USER_SET_VRING_ENABLE, &state))
 427                         return -1;
 428         }
 429
 430         return 0;
 431 }