drivers/net/virtio/virtio_user/vhost_user.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2016 Intel Corporation
   3  */
   4
   5 #include <sys/socket.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <unistd.h>
   9 #include <fcntl.h>
  10 #include <sys/un.h>
  11 #include <string.h>
  12 #include <errno.h>
  13
  14 #include "vhost.h"
  15 #include "virtio_user_dev.h"
  16
  17 /* The version of the protocol we support */
  18 #define VHOST_USER_VERSION    0x1
  19
  20 #define VHOST_MEMORY_MAX_NREGIONS 8
  21 struct vhost_memory {
  22         uint32_t nregions;
  23         uint32_t padding;
  24         struct vhost_memory_region regions[VHOST_MEMORY_MAX_NREGIONS];
  25 };
  26
  27 struct vhost_user_msg {
  28         enum vhost_user_request request;
  29
  30 #define VHOST_USER_VERSION_MASK     0x3
  31 #define VHOST_USER_REPLY_MASK       (0x1 << 2)
  32         uint32_t flags;
  33         uint32_t size; /* the following payload size */
  34         union {
  35 #define VHOST_USER_VRING_IDX_MASK   0xff
  36 #define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
  37                 uint64_t u64;
  38                 struct vhost_vring_state state;
  39                 struct vhost_vring_addr addr;
  40                 struct vhost_memory memory;
  41         } payload;
  42         int fds[VHOST_MEMORY_MAX_NREGIONS];
  43 } __attribute((packed));
  44
  45 #define VHOST_USER_HDR_SIZE offsetof(struct vhost_user_msg, payload.u64)
  46 #define VHOST_USER_PAYLOAD_SIZE \
  47         (sizeof(struct vhost_user_msg) - VHOST_USER_HDR_SIZE)
  48
  49 static int
  50 vhost_user_write(int fd, void *buf, int len, int *fds, int fd_num)
  51 {
  52         int r;
  53         struct msghdr msgh;
  54         struct iovec iov;
  55         size_t fd_size = fd_num * sizeof(int);
  56         char control[CMSG_SPACE(fd_size)];
  57         struct cmsghdr *cmsg;
  58
  59         memset(&msgh, 0, sizeof(msgh));
  60         memset(control, 0, sizeof(control));
  61
  62         iov.iov_base = (uint8_t *)buf;
  63         iov.iov_len = len;
  64
  65         msgh.msg_iov = &iov;
  66         msgh.msg_iovlen = 1;
  67         msgh.msg_control = control;
  68         msgh.msg_controllen = sizeof(control);
  69
  70         cmsg = CMSG_FIRSTHDR(&msgh);
  71         cmsg->cmsg_len = CMSG_LEN(fd_size);
  72         cmsg->cmsg_level = SOL_SOCKET;
  73         cmsg->cmsg_type = SCM_RIGHTS;
  74         memcpy(CMSG_DATA(cmsg), fds, fd_size);
  75
  76         do {
  77                 r = sendmsg(fd, &msgh, 0);
  78         } while (r < 0 && errno == EINTR);
  79
  80         return r;
  81 }
  82
  83 static int
  84 vhost_user_read(int fd, struct vhost_user_msg *msg)
  85 {
  86         uint32_t valid_flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
  87         int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
  88
  89         ret = recv(fd, (void *)msg, sz_hdr, 0);
  90         if (ret < sz_hdr) {
  91                 PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
  92                             ret, sz_hdr);
  93                 goto fail;
  94         }
  95
  96         /* validate msg flags */
  97         if (msg->flags != (valid_flags)) {
  98                 PMD_DRV_LOG(ERR, "Failed to recv msg: flags %x instead of %x.",
  99                             msg->flags, valid_flags);
 100                 goto fail;
 101         }
 102
 103         sz_payload = msg->size;
 104
 105         if ((size_t)sz_payload > sizeof(msg->payload))
 106                 goto fail;
 107
 108         if (sz_payload) {
 109                 ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
 110                 if (ret < sz_payload) {
 111                         PMD_DRV_LOG(ERR,
 112                                 "Failed to recv msg payload: %d instead of %d.",
 113                                 ret, msg->size);
 114                         goto fail;
 115                 }
 116         }
 117
 118         return 0;
 119
 120 fail:
 121         return -1;
 122 }
 123
 124 struct hugepage_file_info {
 125         uint64_t addr;            /**< virtual addr */
 126         size_t   size;            /**< the file size */
 127         char     path[PATH_MAX];  /**< path to backing file */
 128 };
 129
 130 /* Two possible options:
 131  * 1. Match HUGEPAGE_INFO_FMT to find the file storing struct hugepage_file
 132  * array. This is simple but cannot be used in secondary process because
 133  * secondary process will close and munmap that file.
 134  * 2. Match HUGEFILE_FMT to find hugepage files directly.
 135  *
 136  * We choose option 2.
 137  */
 138 static int
 139 get_hugepage_file_info(struct hugepage_file_info huges[], int max)
 140 {
 141         int idx, k, exist;
 142         FILE *f;
 143         char buf[BUFSIZ], *tmp, *tail;
 144         char *str_underline, *str_start;
 145         int huge_index;
 146         uint64_t v_start, v_end;
 147         struct stat stats;
 148
 149         f = fopen("/proc/self/maps", "r");
 150         if (!f) {
 151                 PMD_DRV_LOG(ERR, "cannot open /proc/self/maps");
 152                 return -1;
 153         }
 154
 155         idx = 0;
 156         while (fgets(buf, sizeof(buf), f) != NULL) {
 157                 if (sscanf(buf, "%" PRIx64 "-%" PRIx64, &v_start, &v_end) < 2) {
 158                         PMD_DRV_LOG(ERR, "Failed to parse address");
 159                         goto error;
 160                 }
 161
 162                 tmp = strchr(buf, ' ') + 1; /** skip address */
 163                 tmp = strchr(tmp, ' ') + 1; /** skip perm */
 164                 tmp = strchr(tmp, ' ') + 1; /** skip offset */
 165                 tmp = strchr(tmp, ' ') + 1; /** skip dev */
 166                 tmp = strchr(tmp, ' ') + 1; /** skip inode */
 167                 while (*tmp == ' ')         /** skip spaces */
 168                         tmp++;
 169                 tail = strrchr(tmp, '\n');  /** remove newline if exists */
 170                 if (tail)
 171                         *tail = '\0';
 172
 173                 /* Match HUGEFILE_FMT, aka "%s/%smap_%d",
 174                  * which is defined in eal_filesystem.h
 175                  */
 176                 str_underline = strrchr(tmp, '_');
 177                 if (!str_underline)
 178                         continue;
 179
 180                 str_start = str_underline - strlen("map");
 181                 if (str_start < tmp)
 182                         continue;
 183
 184                 if (sscanf(str_start, "map_%d", &huge_index) != 1)
 185                         continue;
 186
 187                 /* skip duplicated file which is mapped to different regions */
 188                 for (k = 0, exist = -1; k < idx; ++k) {
 189                         if (!strcmp(huges[k].path, tmp)) {
 190                                 exist = k;
 191                                 break;
 192                         }
 193                 }
 194                 if (exist >= 0)
 195                         continue;
 196
 197                 if (idx >= max) {
 198                         PMD_DRV_LOG(ERR, "Exceed maximum of %d", max);
 199                         goto error;
 200                 }
 201
 202                 huges[idx].addr = v_start;
 203                 huges[idx].size = v_end - v_start; /* To be corrected later */
 204                 snprintf(huges[idx].path, PATH_MAX, "%s", tmp);
 205                 idx++;
 206         }
 207
 208         /* correct the size for files who have many regions */
 209         for (k = 0; k < idx; ++k) {
 210                 if (stat(huges[k].path, &stats) < 0) {
 211                         PMD_DRV_LOG(ERR, "Failed to stat %s, %s\n",
 212                                     huges[k].path, strerror(errno));
 213                         continue;
 214                 }
 215                 huges[k].size = stats.st_size;
 216                 PMD_DRV_LOG(INFO, "file %s, size %zx\n",
 217                             huges[k].path, huges[k].size);
 218         }
 219
 220         fclose(f);
 221         return idx;
 222
 223 error:
 224         fclose(f);
 225         return -1;
 226 }
 227
 228 static int
 229 prepare_vhost_memory_user(struct vhost_user_msg *msg, int fds[])
 230 {
 231         int i, num;
 232         struct hugepage_file_info huges[VHOST_MEMORY_MAX_NREGIONS];
 233         struct vhost_memory_region *mr;
 234
 235         num = get_hugepage_file_info(huges, VHOST_MEMORY_MAX_NREGIONS);
 236         if (num < 0) {
 237                 PMD_INIT_LOG(ERR, "Failed to prepare memory for vhost-user");
 238                 return -1;
 239         }
 240
 241         for (i = 0; i < num; ++i) {
 242                 mr = &msg->payload.memory.regions[i];
 243                 mr->guest_phys_addr = huges[i].addr; /* use vaddr! */
 244                 mr->userspace_addr = huges[i].addr;
 245                 mr->memory_size = huges[i].size;
 246                 mr->mmap_offset = 0;
 247                 fds[i] = open(huges[i].path, O_RDWR);
 248         }
 249
 250         msg->payload.memory.nregions = num;
 251         msg->payload.memory.padding = 0;
 252
 253         return 0;
 254 }
 255
 256 static struct vhost_user_msg m;
 257
 258 const char * const vhost_msg_strings[] = {
 259         [VHOST_USER_SET_OWNER] = "VHOST_SET_OWNER",
 260         [VHOST_USER_RESET_OWNER] = "VHOST_RESET_OWNER",
 261         [VHOST_USER_SET_FEATURES] = "VHOST_SET_FEATURES",
 262         [VHOST_USER_GET_FEATURES] = "VHOST_GET_FEATURES",
 263         [VHOST_USER_SET_VRING_CALL] = "VHOST_SET_VRING_CALL",
 264         [VHOST_USER_SET_VRING_NUM] = "VHOST_SET_VRING_NUM",
 265         [VHOST_USER_SET_VRING_BASE] = "VHOST_SET_VRING_BASE",
 266         [VHOST_USER_GET_VRING_BASE] = "VHOST_GET_VRING_BASE",
 267         [VHOST_USER_SET_VRING_ADDR] = "VHOST_SET_VRING_ADDR",
 268         [VHOST_USER_SET_VRING_KICK] = "VHOST_SET_VRING_KICK",
 269         [VHOST_USER_SET_MEM_TABLE] = "VHOST_SET_MEM_TABLE",
 270         [VHOST_USER_SET_VRING_ENABLE] = "VHOST_SET_VRING_ENABLE",
 271 };
 272
 273 static int
 274 vhost_user_sock(struct virtio_user_dev *dev,
 275                 enum vhost_user_request req,
 276                 void *arg)
 277 {
 278         struct vhost_user_msg msg;
 279         struct vhost_vring_file *file = 0;
 280         int need_reply = 0;
 281         int fds[VHOST_MEMORY_MAX_NREGIONS];
 282         int fd_num = 0;
 283         int i, len;
 284         int vhostfd = dev->vhostfd;
 285
 286         RTE_SET_USED(m);
 287
 288         PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
 289
 290         if (dev->is_server && vhostfd < 0)
 291                 return -1;
 292
 293         msg.request = req;
 294         msg.flags = VHOST_USER_VERSION;
 295         msg.size = 0;
 296
 297         switch (req) {
 298         case VHOST_USER_GET_FEATURES:
 299                 need_reply = 1;
 300                 break;
 301
 302         case VHOST_USER_SET_FEATURES:
 303         case VHOST_USER_SET_LOG_BASE:
 304                 msg.payload.u64 = *((__u64 *)arg);
 305                 msg.size = sizeof(m.payload.u64);
 306                 break;
 307
 308         case VHOST_USER_SET_OWNER:
 309         case VHOST_USER_RESET_OWNER:
 310                 break;
 311
 312         case VHOST_USER_SET_MEM_TABLE:
 313                 if (prepare_vhost_memory_user(&msg, fds) < 0)
 314                         return -1;
 315                 fd_num = msg.payload.memory.nregions;
 316                 msg.size = sizeof(m.payload.memory.nregions);
 317                 msg.size += sizeof(m.payload.memory.padding);
 318                 msg.size += fd_num * sizeof(struct vhost_memory_region);
 319                 break;
 320
 321         case VHOST_USER_SET_LOG_FD:
 322                 fds[fd_num++] = *((int *)arg);
 323                 break;
 324
 325         case VHOST_USER_SET_VRING_NUM:
 326         case VHOST_USER_SET_VRING_BASE:
 327         case VHOST_USER_SET_VRING_ENABLE:
 328                 memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
 329                 msg.size = sizeof(m.payload.state);
 330                 break;
 331
 332         case VHOST_USER_GET_VRING_BASE:
 333                 memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
 334                 msg.size = sizeof(m.payload.state);
 335                 need_reply = 1;
 336                 break;
 337
 338         case VHOST_USER_SET_VRING_ADDR:
 339                 memcpy(&msg.payload.addr, arg, sizeof(msg.payload.addr));
 340                 msg.size = sizeof(m.payload.addr);
 341                 break;
 342
 343         case VHOST_USER_SET_VRING_KICK:
 344         case VHOST_USER_SET_VRING_CALL:
 345         case VHOST_USER_SET_VRING_ERR:
 346                 file = arg;
 347                 msg.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK;
 348                 msg.size = sizeof(m.payload.u64);
 349                 if (file->fd > 0)
 350                         fds[fd_num++] = file->fd;
 351                 else
 352                         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
 353                 break;
 354
 355         default:
 356                 PMD_DRV_LOG(ERR, "trying to send unhandled msg type");
 357                 return -1;
 358         }
 359
 360         len = VHOST_USER_HDR_SIZE + msg.size;
 361         if (vhost_user_write(vhostfd, &msg, len, fds, fd_num) < 0) {
 362                 PMD_DRV_LOG(ERR, "%s failed: %s",
 363                             vhost_msg_strings[req], strerror(errno));
 364                 return -1;
 365         }
 366
 367         if (req == VHOST_USER_SET_MEM_TABLE)
 368                 for (i = 0; i < fd_num; ++i)
 369                         close(fds[i]);
 370
 371         if (need_reply) {
 372                 if (vhost_user_read(vhostfd, &msg) < 0) {
 373                         PMD_DRV_LOG(ERR, "Received msg failed: %s",
 374                                     strerror(errno));
 375                         return -1;
 376                 }
 377
 378                 if (req != msg.request) {
 379                         PMD_DRV_LOG(ERR, "Received unexpected msg type");
 380                         return -1;
 381                 }
 382
 383                 switch (req) {
 384                 case VHOST_USER_GET_FEATURES:
 385                         if (msg.size != sizeof(m.payload.u64)) {
 386                                 PMD_DRV_LOG(ERR, "Received bad msg size");
 387                                 return -1;
 388                         }
 389                         *((__u64 *)arg) = msg.payload.u64;
 390                         break;
 391                 case VHOST_USER_GET_VRING_BASE:
 392                         if (msg.size != sizeof(m.payload.state)) {
 393                                 PMD_DRV_LOG(ERR, "Received bad msg size");
 394                                 return -1;
 395                         }
 396                         memcpy(arg, &msg.payload.state,
 397                                sizeof(struct vhost_vring_state));
 398                         break;
 399                 default:
 400                         PMD_DRV_LOG(ERR, "Received unexpected msg type");
 401                         return -1;
 402                 }
 403         }
 404
 405         return 0;
 406 }
 407
 408 #define MAX_VIRTIO_USER_BACKLOG 1
 409 static int
 410 virtio_user_start_server(struct virtio_user_dev *dev, struct sockaddr_un *un)
 411 {
 412         int ret;
 413         int flag;
 414         int fd = dev->listenfd;
 415
 416         ret = bind(fd, (struct sockaddr *)un, sizeof(*un));
 417         if (ret < 0) {
 418                 PMD_DRV_LOG(ERR, "failed to bind to %s: %s; remove it and try again\n",
 419                             dev->path, strerror(errno));
 420                 return -1;
 421         }
 422         ret = listen(fd, MAX_VIRTIO_USER_BACKLOG);
 423         if (ret < 0)
 424                 return -1;
 425
 426         flag = fcntl(fd, F_GETFL);
 427         fcntl(fd, F_SETFL, flag | O_NONBLOCK);
 428
 429         return 0;
 430 }
 431
 432 /**
 433  * Set up environment to talk with a vhost user backend.
 434  *
 435  * @return
 436  *   - (-1) if fail;
 437  *   - (0) if succeed.
 438  */
 439 static int
 440 vhost_user_setup(struct virtio_user_dev *dev)
 441 {
 442         int fd;
 443         int flag;
 444         struct sockaddr_un un;
 445
 446         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 447         if (fd < 0) {
 448                 PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
 449                 return -1;
 450         }
 451
 452         flag = fcntl(fd, F_GETFD);
 453         if (fcntl(fd, F_SETFD, flag | FD_CLOEXEC) < 0)
 454                 PMD_DRV_LOG(WARNING, "fcntl failed, %s", strerror(errno));
 455
 456         memset(&un, 0, sizeof(un));
 457         un.sun_family = AF_UNIX;
 458         snprintf(un.sun_path, sizeof(un.sun_path), "%s", dev->path);
 459
 460         if (dev->is_server) {
 461                 dev->listenfd = fd;
 462                 if (virtio_user_start_server(dev, &un) < 0) {
 463                         PMD_DRV_LOG(ERR, "virtio-user startup fails in server mode");
 464                         close(fd);
 465                         return -1;
 466                 }
 467                 dev->vhostfd = -1;
 468         } else {
 469                 if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
 470                         PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
 471                         close(fd);
 472                         return -1;
 473                 }
 474                 dev->vhostfd = fd;
 475         }
 476
 477         return 0;
 478 }
 479
 480 static int
 481 vhost_user_enable_queue_pair(struct virtio_user_dev *dev,
 482                              uint16_t pair_idx,
 483                              int enable)
 484 {
 485         int i;
 486
 487         for (i = 0; i < 2; ++i) {
 488                 struct vhost_vring_state state = {
 489                         .index = pair_idx * 2 + i,
 490                         .num   = enable,
 491                 };
 492
 493                 if (vhost_user_sock(dev, VHOST_USER_SET_VRING_ENABLE, &state))
 494                         return -1;
 495         }
 496
 497         return 0;
 498 }
 499
 500 struct virtio_user_backend_ops ops_user = {
 501         .setup = vhost_user_setup,
 502         .send_request = vhost_user_sock,
 503         .enable_qp = vhost_user_enable_queue_pair
 504 };