drivers/net/vdev_netvsc/vdev_netvsc.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright 2017 6WIND S.A.
   3  * Copyright 2017 Mellanox Technologies, Ltd.
   4  */
   5
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <inttypes.h>
   9 #include <linux/sockios.h>
  10 #include <net/if.h>
  11 #include <net/if_arp.h>
  12 #include <netinet/ip.h>
  13 #include <stdarg.h>
  14 #include <stddef.h>
  15 #include <stdlib.h>
  16 #include <stdint.h>
  17 #include <stdio.h>
  18 #include <string.h>
  19 #include <sys/ioctl.h>
  20 #include <sys/queue.h>
  21 #include <sys/socket.h>
  22 #include <unistd.h>
  23
  24 #include <rte_alarm.h>
  25 #include <rte_bus.h>
  26 #include <rte_bus_vdev.h>
  27 #include <rte_common.h>
  28 #include <rte_config.h>
  29 #include <rte_dev.h>
  30 #include <rte_errno.h>
  31 #include <rte_ethdev.h>
  32 #include <rte_ether.h>
  33 #include <rte_hypervisor.h>
  34 #include <rte_kvargs.h>
  35 #include <rte_log.h>
  36
  37 #define VDEV_NETVSC_DRIVER net_vdev_netvsc
  38 #define VDEV_NETVSC_DRIVER_NAME RTE_STR(VDEV_NETVSC_DRIVER)
  39 #define VDEV_NETVSC_ARG_IFACE "iface"
  40 #define VDEV_NETVSC_ARG_MAC "mac"
  41 #define VDEV_NETVSC_ARG_FORCE "force"
  42 #define VDEV_NETVSC_ARG_IGNORE "ignore"
  43 #define VDEV_NETVSC_PROBE_MS 1000
  44
  45 #define NETVSC_CLASS_ID "{f8615163-df3e-46c5-913f-f2d2f965ed0e}"
  46 #define NETVSC_MAX_ROUTE_LINE_SIZE 300
  47
  48 #define DRV_LOG(level, ...) \
  49         rte_log(RTE_LOG_ ## level, \
  50                 vdev_netvsc_logtype, \
  51                 RTE_FMT(VDEV_NETVSC_DRIVER_NAME ": " \
  52                         RTE_FMT_HEAD(__VA_ARGS__,) "\n", \
  53                 RTE_FMT_TAIL(__VA_ARGS__,)))
  54
  55 /** Driver-specific log messages type. */
  56 static int vdev_netvsc_logtype;
  57
  58 /** Context structure for a vdev_netvsc instance. */
  59 struct vdev_netvsc_ctx {
  60         LIST_ENTRY(vdev_netvsc_ctx) entry; /**< Next entry in list. */
  61         unsigned int id;                   /**< Unique ID. */
  62         char name[64];                     /**< Unique name. */
  63         char devname[64];                  /**< Fail-safe instance name. */
  64         char devargs[256];                 /**< Fail-safe device arguments. */
  65         char if_name[IF_NAMESIZE];         /**< NetVSC netdevice name. */
  66         unsigned int if_index;             /**< NetVSC netdevice index. */
  67         struct ether_addr if_addr;         /**< NetVSC MAC address. */
  68         int pipe[2];                       /**< Fail-safe communication pipe. */
  69         char yield[256];                   /**< PCI sub-device arguments. */
  70 };
  71
  72 /** Context list is common to all driver instances. */
  73 static LIST_HEAD(, vdev_netvsc_ctx) vdev_netvsc_ctx_list =
  74         LIST_HEAD_INITIALIZER(vdev_netvsc_ctx_list);
  75
  76 /** Number of entries in context list. */
  77 static unsigned int vdev_netvsc_ctx_count;
  78
  79 /** Number of driver instances relying on context list. */
  80 static unsigned int vdev_netvsc_ctx_inst;
  81
  82 /**
  83  * Destroy a vdev_netvsc context instance.
  84  *
  85  * @param ctx
  86  *   Context to destroy.
  87  */
  88 static void
  89 vdev_netvsc_ctx_destroy(struct vdev_netvsc_ctx *ctx)
  90 {
  91         if (ctx->pipe[0] != -1)
  92                 close(ctx->pipe[0]);
  93         if (ctx->pipe[1] != -1)
  94                 close(ctx->pipe[1]);
  95         free(ctx);
  96 }
  97
  98 /**
  99  * Iterate over system network interfaces.
 100  *
 101  * This function runs a given callback function for each netdevice found on
 102  * the system.
 103  *
 104  * @param func
 105  *   Callback function pointer. List traversal is aborted when this function
 106  *   returns a nonzero value.
 107  * @param ...
 108  *   Variable parameter list passed as @p va_list to @p func.
 109  *
 110  * @return
 111  *   0 when the entire list is traversed successfully, a negative error code
 112  *   in case or failure, or the nonzero value returned by @p func when list
 113  *   traversal is aborted.
 114  */
 115 static int
 116 vdev_netvsc_foreach_iface(int (*func)(const struct if_nameindex *iface,
 117                                       const struct ether_addr *eth_addr,
 118                                       va_list ap), ...)
 119 {
 120         struct if_nameindex *iface = if_nameindex();
 121         int s = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
 122         unsigned int i;
 123         int ret = 0;
 124
 125         if (!iface) {
 126                 ret = -ENOBUFS;
 127                 DRV_LOG(ERR, "cannot retrieve system network interfaces");
 128                 goto error;
 129         }
 130         if (s == -1) {
 131                 ret = -errno;
 132                 DRV_LOG(ERR, "cannot open socket: %s", rte_strerror(errno));
 133                 goto error;
 134         }
 135         for (i = 0; iface[i].if_name; ++i) {
 136                 struct ifreq req;
 137                 struct ether_addr eth_addr;
 138                 va_list ap;
 139
 140                 strncpy(req.ifr_name, iface[i].if_name, sizeof(req.ifr_name));
 141                 if (ioctl(s, SIOCGIFHWADDR, &req) == -1) {
 142                         DRV_LOG(WARNING, "cannot retrieve information about"
 143                                          " interface \"%s\": %s",
 144                                          req.ifr_name, rte_strerror(errno));
 145                         continue;
 146                 }
 147                 if (req.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
 148                         DRV_LOG(DEBUG, "interface %s is non-ethernet device",
 149                                 req.ifr_name);
 150                         continue;
 151                 }
 152                 memcpy(eth_addr.addr_bytes, req.ifr_hwaddr.sa_data,
 153                        RTE_DIM(eth_addr.addr_bytes));
 154                 va_start(ap, func);
 155                 ret = func(&iface[i], &eth_addr, ap);
 156                 va_end(ap);
 157                 if (ret)
 158                         break;
 159         }
 160 error:
 161         if (s != -1)
 162                 close(s);
 163         if (iface)
 164                 if_freenameindex(iface);
 165         return ret;
 166 }
 167
 168 /**
 169  * Determine if a network interface is NetVSC.
 170  *
 171  * @param[in] iface
 172  *   Pointer to netdevice description structure (name and index).
 173  *
 174  * @return
 175  *   A nonzero value when interface is detected as NetVSC. In case of error,
 176  *   rte_errno is updated and 0 returned.
 177  */
 178 static int
 179 vdev_netvsc_iface_is_netvsc(const struct if_nameindex *iface)
 180 {
 181         static const char temp[] = "/sys/class/net/%s/device/class_id";
 182         char path[sizeof(temp) + IF_NAMESIZE];
 183         FILE *f;
 184         int ret;
 185         int len = 0;
 186
 187         ret = snprintf(path, sizeof(path), temp, iface->if_name);
 188         if (ret == -1 || (size_t)ret >= sizeof(path)) {
 189                 rte_errno = ENOBUFS;
 190                 return 0;
 191         }
 192         f = fopen(path, "r");
 193         if (!f) {
 194                 rte_errno = errno;
 195                 return 0;
 196         }
 197         ret = fscanf(f, NETVSC_CLASS_ID "%n", &len);
 198         if (ret == EOF)
 199                 rte_errno = errno;
 200         ret = len == (int)strlen(NETVSC_CLASS_ID);
 201         fclose(f);
 202         return ret;
 203 }
 204
 205 /**
 206  * Determine if a network interface has a route.
 207  *
 208  * @param[in] name
 209  *   Network device name.
 210  *
 211  * @return
 212  *   A nonzero value when interface has an route. In case of error,
 213  *   rte_errno is updated and 0 returned.
 214  */
 215 static int
 216 vdev_netvsc_has_route(const char *name)
 217 {
 218         FILE *fp;
 219         int ret = 0;
 220         char route[NETVSC_MAX_ROUTE_LINE_SIZE];
 221         char *netdev;
 222
 223         fp = fopen("/proc/net/route", "r");
 224         if (!fp) {
 225                 rte_errno = errno;
 226                 return 0;
 227         }
 228         while (fgets(route, NETVSC_MAX_ROUTE_LINE_SIZE, fp) != NULL) {
 229                 netdev = strtok(route, "\t");
 230                 if (strcmp(netdev, name) == 0) {
 231                         ret = 1;
 232                         break;
 233                 }
 234                 /* Move file pointer to the next line. */
 235                 while (strchr(route, '\n') == NULL &&
 236                        fgets(route, NETVSC_MAX_ROUTE_LINE_SIZE, fp) != NULL)
 237                         ;
 238         }
 239         fclose(fp);
 240         return ret;
 241 }
 242
 243 /**
 244  * Retrieve network interface data from sysfs symbolic link.
 245  *
 246  * @param[out] buf
 247  *   Output data buffer.
 248  * @param size
 249  *   Output buffer size.
 250  * @param[in] if_name
 251  *   Netdevice name.
 252  * @param[in] relpath
 253  *   Symbolic link path relative to netdevice sysfs entry.
 254  *
 255  * @return
 256  *   0 on success, a negative error code otherwise.
 257  */
 258 static int
 259 vdev_netvsc_sysfs_readlink(char *buf, size_t size, const char *if_name,
 260                            const char *relpath)
 261 {
 262         int ret;
 263
 264         ret = snprintf(buf, size, "/sys/class/net/%s/%s", if_name, relpath);
 265         if (ret == -1 || (size_t)ret >= size)
 266                 return -ENOBUFS;
 267         ret = readlink(buf, buf, size);
 268         if (ret == -1)
 269                 return -errno;
 270         if ((size_t)ret >= size - 1)
 271                 return -ENOBUFS;
 272         buf[ret] = '\0';
 273         return 0;
 274 }
 275
 276 /**
 277  * Probe a network interface to associate with vdev_netvsc context.
 278  *
 279  * This function determines if the network device matches the properties of
 280  * the NetVSC interface associated with the vdev_netvsc context and
 281  * communicates its bus address to the fail-safe PMD instance if so.
 282  *
 283  * It is normally used with vdev_netvsc_foreach_iface().
 284  *
 285  * @param[in] iface
 286  *   Pointer to netdevice description structure (name and index).
 287  * @param[in] eth_addr
 288  *   MAC address associated with @p iface.
 289  * @param ap
 290  *   Variable arguments list comprising:
 291  *
 292  *   - struct vdev_netvsc_ctx *ctx:
 293  *     Context to associate network interface with.
 294  *
 295  * @return
 296  *   A nonzero value when interface matches, 0 otherwise or in case of
 297  *   error.
 298  */
 299 static int
 300 vdev_netvsc_device_probe(const struct if_nameindex *iface,
 301                     const struct ether_addr *eth_addr,
 302                     va_list ap)
 303 {
 304         struct vdev_netvsc_ctx *ctx = va_arg(ap, struct vdev_netvsc_ctx *);
 305         char buf[RTE_MAX(sizeof(ctx->yield), 256u)];
 306         const char *addr;
 307         size_t len;
 308         int ret;
 309
 310         /* Skip non-matching or unwanted NetVSC interfaces. */
 311         if (ctx->if_index == iface->if_index) {
 312                 if (!strcmp(ctx->if_name, iface->if_name))
 313                         return 0;
 314                 DRV_LOG(DEBUG,
 315                         "NetVSC interface \"%s\" (index %u) renamed \"%s\"",
 316                         ctx->if_name, ctx->if_index, iface->if_name);
 317                 strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
 318                 return 0;
 319         }
 320         if (vdev_netvsc_iface_is_netvsc(iface))
 321                 return 0;
 322         if (!is_same_ether_addr(eth_addr, &ctx->if_addr))
 323                 return 0;
 324         /* Look for associated PCI device. */
 325         ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name,
 326                                          "device/subsystem");
 327         if (ret)
 328                 return 0;
 329         addr = strrchr(buf, '/');
 330         addr = addr ? addr + 1 : buf;
 331         if (strcmp(addr, "pci"))
 332                 return 0;
 333         ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name,
 334                                          "device");
 335         if (ret)
 336                 return 0;
 337         addr = strrchr(buf, '/');
 338         addr = addr ? addr + 1 : buf;
 339         len = strlen(addr);
 340         if (!len)
 341                 return 0;
 342         /* Send PCI device argument to fail-safe PMD instance. */
 343         if (strcmp(addr, ctx->yield))
 344                 DRV_LOG(DEBUG, "associating PCI device \"%s\" with NetVSC"
 345                         " interface \"%s\" (index %u)", addr, ctx->if_name,
 346                         ctx->if_index);
 347         memmove(buf, addr, len + 1);
 348         addr = buf;
 349         buf[len] = '\n';
 350         ret = write(ctx->pipe[1], addr, len + 1);
 351         buf[len] = '\0';
 352         if (ret == -1) {
 353                 if (errno == EINTR || errno == EAGAIN)
 354                         return 1;
 355                 DRV_LOG(WARNING, "cannot associate PCI device name \"%s\" with"
 356                         " interface \"%s\": %s", addr, ctx->if_name,
 357                         rte_strerror(errno));
 358                 return 1;
 359         }
 360         if ((size_t)ret != len + 1) {
 361                 /*
 362                  * Attempt to override previous partial write, no need to
 363                  * recover if that fails.
 364                  */
 365                 ret = write(ctx->pipe[1], "\n", 1);
 366                 (void)ret;
 367                 return 1;
 368         }
 369         fsync(ctx->pipe[1]);
 370         memcpy(ctx->yield, addr, len + 1);
 371         return 1;
 372 }
 373
 374 /**
 375  * Alarm callback that regularly probes system network interfaces.
 376  *
 377  * This callback runs at a frequency determined by VDEV_NETVSC_PROBE_MS as
 378  * long as an vdev_netvsc context instance exists.
 379  *
 380  * @param arg
 381  *   Ignored.
 382  */
 383 static void
 384 vdev_netvsc_alarm(__rte_unused void *arg)
 385 {
 386         struct vdev_netvsc_ctx *ctx;
 387         int ret;
 388
 389         LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry) {
 390                 ret = vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, ctx);
 391                 if (ret)
 392                         break;
 393         }
 394         if (!vdev_netvsc_ctx_count)
 395                 return;
 396         ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
 397                                 vdev_netvsc_alarm, NULL);
 398         if (ret < 0) {
 399                 DRV_LOG(ERR, "unable to reschedule alarm callback: %s",
 400                         rte_strerror(-ret));
 401         }
 402 }
 403
 404 /**
 405  * Probe a NetVSC interface to generate a vdev_netvsc context from.
 406  *
 407  * This function instantiates vdev_netvsc contexts either for all NetVSC
 408  * devices found on the system or only a subset provided as device
 409  * arguments.
 410  *
 411  * It is normally used with vdev_netvsc_foreach_iface().
 412  *
 413  * @param[in] iface
 414  *   Pointer to netdevice description structure (name and index).
 415  * @param[in] eth_addr
 416  *   MAC address associated with @p iface.
 417  * @param ap
 418  *   Variable arguments list comprising:
 419  *
 420  *   - const char *name:
 421  *     Name associated with current driver instance.
 422  *
 423  *   - struct rte_kvargs *kvargs:
 424  *     Device arguments provided to current driver instance.
 425  *
 426  *   - int force:
 427  *     Accept specified interface even if not detected as NetVSC.
 428  *
 429  *   - unsigned int specified:
 430  *     Number of specific netdevices provided as device arguments.
 431  *
 432  *   - unsigned int *matched:
 433  *     The number of specified netdevices matched by this function.
 434  *
 435  * @return
 436  *   A nonzero value when interface matches, 0 otherwise or in case of
 437  *   error.
 438  */
 439 static int
 440 vdev_netvsc_netvsc_probe(const struct if_nameindex *iface,
 441                          const struct ether_addr *eth_addr,
 442                          va_list ap)
 443 {
 444         const char *name = va_arg(ap, const char *);
 445         struct rte_kvargs *kvargs = va_arg(ap, struct rte_kvargs *);
 446         int force = va_arg(ap, int);
 447         unsigned int specified = va_arg(ap, unsigned int);
 448         unsigned int *matched = va_arg(ap, unsigned int *);
 449         unsigned int i;
 450         struct vdev_netvsc_ctx *ctx;
 451         int ret;
 452
 453         /* Probe all interfaces when none are specified. */
 454         if (specified) {
 455                 for (i = 0; i != kvargs->count; ++i) {
 456                         const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
 457
 458                         if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE)) {
 459                                 if (!strcmp(pair->value, iface->if_name))
 460                                         break;
 461                         } else if (!strcmp(pair->key, VDEV_NETVSC_ARG_MAC)) {
 462                                 struct ether_addr tmp;
 463
 464                                 if (sscanf(pair->value,
 465                                            "%" SCNx8 ":%" SCNx8 ":%" SCNx8 ":"
 466                                            "%" SCNx8 ":%" SCNx8 ":%" SCNx8,
 467                                            &tmp.addr_bytes[0],
 468                                            &tmp.addr_bytes[1],
 469                                            &tmp.addr_bytes[2],
 470                                            &tmp.addr_bytes[3],
 471                                            &tmp.addr_bytes[4],
 472                                            &tmp.addr_bytes[5]) != 6) {
 473                                         DRV_LOG(ERR,
 474                                                 "invalid MAC address format"
 475                                                 " \"%s\"",
 476                                                 pair->value);
 477                                         return -EINVAL;
 478                                 }
 479                                 if (is_same_ether_addr(eth_addr, &tmp))
 480                                         break;
 481                         }
 482                 }
 483                 if (i == kvargs->count)
 484                         return 0;
 485                 ++(*matched);
 486         }
 487         /* Weed out interfaces already handled. */
 488         LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry)
 489                 if (ctx->if_index == iface->if_index)
 490                         break;
 491         if (ctx) {
 492                 if (!specified)
 493                         return 0;
 494                 DRV_LOG(WARNING,
 495                         "interface \"%s\" (index %u) is already handled,"
 496                         " skipping",
 497                         iface->if_name, iface->if_index);
 498                 return 0;
 499         }
 500         if (!vdev_netvsc_iface_is_netvsc(iface)) {
 501                 if (!specified || !force)
 502                         return 0;
 503                 DRV_LOG(WARNING,
 504                         "using non-NetVSC interface \"%s\" (index %u)",
 505                         iface->if_name, iface->if_index);
 506         }
 507         /* Routed NetVSC should not be probed. */
 508         if (vdev_netvsc_has_route(iface->if_name)) {
 509                 if (!specified || !force)
 510                         return 0;
 511                 DRV_LOG(WARNING, "using routed NetVSC interface \"%s\""
 512                         " (index %u)", iface->if_name, iface->if_index);
 513         }
 514         /* Create interface context. */
 515         ctx = calloc(1, sizeof(*ctx));
 516         if (!ctx) {
 517                 ret = -errno;
 518                 DRV_LOG(ERR, "cannot allocate context for interface \"%s\": %s",
 519                         iface->if_name, rte_strerror(errno));
 520                 goto error;
 521         }
 522         ctx->id = vdev_netvsc_ctx_count;
 523         strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
 524         ctx->if_index = iface->if_index;
 525         ctx->if_addr = *eth_addr;
 526         ctx->pipe[0] = -1;
 527         ctx->pipe[1] = -1;
 528         ctx->yield[0] = '\0';
 529         if (pipe(ctx->pipe) == -1) {
 530                 ret = -errno;
 531                 DRV_LOG(ERR,
 532                         "cannot allocate control pipe for interface \"%s\": %s",
 533                         ctx->if_name, rte_strerror(errno));
 534                 goto error;
 535         }
 536         for (i = 0; i != RTE_DIM(ctx->pipe); ++i) {
 537                 int flf = fcntl(ctx->pipe[i], F_GETFL);
 538
 539                 if (flf != -1 &&
 540                     fcntl(ctx->pipe[i], F_SETFL, flf | O_NONBLOCK) != -1)
 541                         continue;
 542                 ret = -errno;
 543                 DRV_LOG(ERR, "cannot toggle non-blocking flag on control file"
 544                         " descriptor #%u (%d): %s", i, ctx->pipe[i],
 545                         rte_strerror(errno));
 546                 goto error;
 547         }
 548         /* Generate virtual device name and arguments. */
 549         i = 0;
 550         ret = snprintf(ctx->name, sizeof(ctx->name), "%s_id%u",
 551                        name, ctx->id);
 552         if (ret == -1 || (size_t)ret >= sizeof(ctx->name))
 553                 ++i;
 554         ret = snprintf(ctx->devname, sizeof(ctx->devname), "net_failsafe_%s",
 555                        ctx->name);
 556         if (ret == -1 || (size_t)ret >= sizeof(ctx->devname))
 557                 ++i;
 558         ret = snprintf(ctx->devargs, sizeof(ctx->devargs),
 559                        "fd(%d),dev(net_tap_%s,remote=%s)",
 560                        ctx->pipe[0], ctx->name, ctx->if_name);
 561         if (ret == -1 || (size_t)ret >= sizeof(ctx->devargs))
 562                 ++i;
 563         if (i) {
 564                 ret = -ENOBUFS;
 565                 DRV_LOG(ERR, "generated virtual device name or argument list"
 566                         " too long for interface \"%s\"", ctx->if_name);
 567                 goto error;
 568         }
 569         /* Request virtual device generation. */
 570         DRV_LOG(DEBUG, "generating virtual device \"%s\" with arguments \"%s\"",
 571                 ctx->devname, ctx->devargs);
 572         vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, ctx);
 573         ret = rte_eal_hotplug_add("vdev", ctx->devname, ctx->devargs);
 574         if (ret)
 575                 goto error;
 576         LIST_INSERT_HEAD(&vdev_netvsc_ctx_list, ctx, entry);
 577         ++vdev_netvsc_ctx_count;
 578         DRV_LOG(DEBUG, "added NetVSC interface \"%s\" to context list",
 579                 ctx->if_name);
 580         return 0;
 581 error:
 582         if (ctx)
 583                 vdev_netvsc_ctx_destroy(ctx);
 584         return ret;
 585 }
 586
 587 /**
 588  * Probe NetVSC interfaces.
 589  *
 590  * This function probes system netdevices according to the specified device
 591  * arguments and starts a periodic alarm callback to notify the resulting
 592  * fail-safe PMD instances of their sub-devices whereabouts.
 593  *
 594  * @param dev
 595  *   Virtual device context for driver instance.
 596  *
 597  * @return
 598  *    Always 0, even in case of errors.
 599  */
 600 static int
 601 vdev_netvsc_vdev_probe(struct rte_vdev_device *dev)
 602 {
 603         static const char *const vdev_netvsc_arg[] = {
 604                 VDEV_NETVSC_ARG_IFACE,
 605                 VDEV_NETVSC_ARG_MAC,
 606                 VDEV_NETVSC_ARG_FORCE,
 607                 VDEV_NETVSC_ARG_IGNORE,
 608                 NULL,
 609         };
 610         const char *name = rte_vdev_device_name(dev);
 611         const char *args = rte_vdev_device_args(dev);
 612         struct rte_kvargs *kvargs = rte_kvargs_parse(args ? args : "",
 613                                                      vdev_netvsc_arg);
 614         unsigned int specified = 0;
 615         unsigned int matched = 0;
 616         int force = 0;
 617         int ignore = 0;
 618         unsigned int i;
 619         int ret;
 620
 621         DRV_LOG(DEBUG, "invoked as \"%s\", using arguments \"%s\"", name, args);
 622         if (!kvargs) {
 623                 DRV_LOG(ERR, "cannot parse arguments list");
 624                 goto error;
 625         }
 626         for (i = 0; i != kvargs->count; ++i) {
 627                 const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
 628
 629                 if (!strcmp(pair->key, VDEV_NETVSC_ARG_FORCE))
 630                         force = !!atoi(pair->value);
 631                 else if (!strcmp(pair->key, VDEV_NETVSC_ARG_IGNORE))
 632                         ignore = !!atoi(pair->value);
 633                 else if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE) ||
 634                          !strcmp(pair->key, VDEV_NETVSC_ARG_MAC))
 635                         ++specified;
 636         }
 637         if (ignore) {
 638                 if (kvargs)
 639                         rte_kvargs_free(kvargs);
 640                 return 0;
 641         }
 642         rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
 643         /* Gather interfaces. */
 644         ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, name, kvargs,
 645                                         force, specified, &matched);
 646         if (ret < 0)
 647                 goto error;
 648         if (matched < specified)
 649                 DRV_LOG(WARNING,
 650                         "some of the specified parameters did not match"
 651                         " recognized network interfaces");
 652         ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
 653                                 vdev_netvsc_alarm, NULL);
 654         if (ret < 0) {
 655                 DRV_LOG(ERR, "unable to schedule alarm callback: %s",
 656                         rte_strerror(-ret));
 657                 goto error;
 658         }
 659 error:
 660         if (kvargs)
 661                 rte_kvargs_free(kvargs);
 662         ++vdev_netvsc_ctx_inst;
 663         return 0;
 664 }
 665
 666 /**
 667  * Remove driver instance.
 668  *
 669  * The alarm callback and underlying vdev_netvsc context instances are only
 670  * destroyed after the last PMD instance is removed.
 671  *
 672  * @param dev
 673  *   Virtual device context for driver instance.
 674  *
 675  * @return
 676  *   Always 0.
 677  */
 678 static int
 679 vdev_netvsc_vdev_remove(__rte_unused struct rte_vdev_device *dev)
 680 {
 681         if (--vdev_netvsc_ctx_inst)
 682                 return 0;
 683         rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
 684         while (!LIST_EMPTY(&vdev_netvsc_ctx_list)) {
 685                 struct vdev_netvsc_ctx *ctx = LIST_FIRST(&vdev_netvsc_ctx_list);
 686
 687                 LIST_REMOVE(ctx, entry);
 688                 --vdev_netvsc_ctx_count;
 689                 vdev_netvsc_ctx_destroy(ctx);
 690         }
 691         return 0;
 692 }
 693
 694 /** Virtual device descriptor. */
 695 static struct rte_vdev_driver vdev_netvsc_vdev = {
 696         .probe = vdev_netvsc_vdev_probe,
 697         .remove = vdev_netvsc_vdev_remove,
 698 };
 699
 700 RTE_PMD_REGISTER_VDEV(VDEV_NETVSC_DRIVER, vdev_netvsc_vdev);
 701 RTE_PMD_REGISTER_ALIAS(VDEV_NETVSC_DRIVER, eth_vdev_netvsc);
 702 RTE_PMD_REGISTER_PARAM_STRING(net_vdev_netvsc,
 703                               VDEV_NETVSC_ARG_IFACE "=<string> "
 704                               VDEV_NETVSC_ARG_MAC "=<string> "
 705                               VDEV_NETVSC_ARG_FORCE "=<int> "
 706                               VDEV_NETVSC_ARG_IGNORE "=<int>");
 707
 708 /** Initialize driver log type. */
 709 RTE_INIT(vdev_netvsc_init_log)
 710 {
 711         vdev_netvsc_logtype = rte_log_register("pmd.vdev_netvsc");
 712         if (vdev_netvsc_logtype >= 0)
 713                 rte_log_set_level(vdev_netvsc_logtype, RTE_LOG_NOTICE);
 714 }
 715
 716 /** Compare function for vdev find device operation. */
 717 static int
 718 vdev_netvsc_cmp_rte_device(const struct rte_device *dev1,
 719                            __rte_unused const void *_dev2)
 720 {
 721         return strcmp(dev1->devargs->name, VDEV_NETVSC_DRIVER_NAME);
 722 }
 723
 724 /**
 725  * A callback called by vdev bus scan function to ensure this driver probing
 726  * automatically in Hyper-V VM system unless it already exists in the
 727  * devargs list.
 728  */
 729 static void
 730 vdev_netvsc_scan_callback(__rte_unused void *arg)
 731 {
 732         struct rte_vdev_device *dev;
 733         struct rte_devargs *devargs;
 734         struct rte_bus *vbus = rte_bus_find_by_name("vdev");
 735
 736         TAILQ_FOREACH(devargs, &devargs_list, next)
 737                 if (!strcmp(devargs->name, VDEV_NETVSC_DRIVER_NAME))
 738                         return;
 739         dev = (struct rte_vdev_device *)vbus->find_device(NULL,
 740                 vdev_netvsc_cmp_rte_device, VDEV_NETVSC_DRIVER_NAME);
 741         if (dev)
 742                 return;
 743         if (rte_eal_devargs_add(RTE_DEVTYPE_VIRTUAL, VDEV_NETVSC_DRIVER_NAME))
 744                 DRV_LOG(ERR, "unable to add netvsc devargs.");
 745 }
 746
 747 /** Initialize the custom scan. */
 748 RTE_INIT(vdev_netvsc_custom_scan_add)
 749 {
 750         if (rte_hypervisor_get() == RTE_HYPERVISOR_HYPERV)
 751                 rte_vdev_add_custom_scan(vdev_netvsc_scan_callback, NULL);
 752 }