xref: /dpdk/drivers/net/vdev_netvsc/vdev_netvsc.c (revision f69ed1044230c218c9afd8f1b47b6fe6aa1eeec5)
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 <linux/netlink.h>
11 #include <linux/rtnetlink.h>
12 #include <net/if.h>
13 #include <net/if_arp.h>
14 #include <netinet/ip.h>
15 #include <stdarg.h>
16 #include <stddef.h>
17 #include <stdlib.h>
18 #include <stdint.h>
19 #include <stdio.h>
20 #include <string.h>
21 #include <sys/ioctl.h>
22 #include <sys/queue.h>
23 #include <sys/socket.h>
24 #include <unistd.h>
25 
26 #include <rte_alarm.h>
27 #include <rte_bus.h>
28 #include <rte_bus_vdev.h>
29 #include <rte_common.h>
30 #include <rte_dev.h>
31 #include <rte_errno.h>
32 #include <rte_ethdev.h>
33 #include <rte_ether.h>
34 #include <rte_hypervisor.h>
35 #include <rte_kvargs.h>
36 #include <rte_log.h>
37 #include <rte_string_fns.h>
38 
39 #define VDEV_NETVSC_DRIVER net_vdev_netvsc
40 #define VDEV_NETVSC_DRIVER_NAME RTE_STR(VDEV_NETVSC_DRIVER)
41 #define VDEV_NETVSC_DRIVER_NAME_LEN 15
42 #define VDEV_NETVSC_ARG_IFACE "iface"
43 #define VDEV_NETVSC_ARG_MAC "mac"
44 #define VDEV_NETVSC_ARG_FORCE "force"
45 #define VDEV_NETVSC_ARG_IGNORE "ignore"
46 #define VDEV_NETVSC_PROBE_MS 1000
47 
48 #define NETVSC_CLASS_ID "{f8615163-df3e-46c5-913f-f2d2f965ed0e}"
49 #define NETVSC_MAX_ROUTE_LINE_SIZE 300
50 
51 #define DRV_LOG(level, ...) \
52 	rte_log(RTE_LOG_ ## level, \
53 		vdev_netvsc_logtype, \
54 		RTE_FMT(VDEV_NETVSC_DRIVER_NAME ": " \
55 			RTE_FMT_HEAD(__VA_ARGS__,) "\n", \
56 		RTE_FMT_TAIL(__VA_ARGS__,)))
57 
58 /** Driver-specific log messages type. */
59 static int vdev_netvsc_logtype;
60 
61 /** Context structure for a vdev_netvsc instance. */
62 struct vdev_netvsc_ctx {
63 	LIST_ENTRY(vdev_netvsc_ctx) entry; /**< Next entry in list. */
64 	unsigned int id;		   /**< Unique ID. */
65 	char name[64];			   /**< Unique name. */
66 	char devname[64];		   /**< Fail-safe instance name. */
67 	char devargs[256];		   /**< Fail-safe device arguments. */
68 	char if_name[IF_NAMESIZE];	   /**< NetVSC netdevice name. */
69 	unsigned int if_index;		   /**< NetVSC netdevice index. */
70 	struct rte_ether_addr if_addr;	   /**< NetVSC MAC address. */
71 	int pipe[2];			   /**< Fail-safe communication pipe. */
72 	char yield[256];		   /**< PCI sub-device arguments. */
73 };
74 
75 /** Context list is common to all driver instances. */
76 static LIST_HEAD(, vdev_netvsc_ctx) vdev_netvsc_ctx_list =
77 	LIST_HEAD_INITIALIZER(vdev_netvsc_ctx_list);
78 
79 /** Number of entries in context list. */
80 static unsigned int vdev_netvsc_ctx_count;
81 
82 /** Number of driver instances relying on context list. */
83 static unsigned int vdev_netvsc_ctx_inst;
84 
85 /**
86  * Destroy a vdev_netvsc context instance.
87  *
88  * @param ctx
89  *   Context to destroy.
90  */
91 static void
92 vdev_netvsc_ctx_destroy(struct vdev_netvsc_ctx *ctx)
93 {
94 	if (ctx->pipe[0] != -1)
95 		close(ctx->pipe[0]);
96 	if (ctx->pipe[1] != -1)
97 		close(ctx->pipe[1]);
98 	free(ctx);
99 }
100 
101 /**
102  * Determine if a network interface is NetVSC.
103  *
104  * @param[in] iface
105  *   Pointer to netdevice description structure (name and index).
106  *
107  * @return
108  *   A nonzero value when interface is detected as NetVSC. In case of error,
109  *   rte_errno is updated and 0 returned.
110  */
111 static int
112 vdev_netvsc_iface_is_netvsc(const struct if_nameindex *iface)
113 {
114 	static const char temp[] = "/sys/class/net/%s/device/class_id";
115 	char path[sizeof(temp) + IF_NAMESIZE];
116 	FILE *f;
117 	int ret;
118 	int len = 0;
119 
120 	ret = snprintf(path, sizeof(path), temp, iface->if_name);
121 	if (ret == -1 || (size_t)ret >= sizeof(path)) {
122 		rte_errno = ENOBUFS;
123 		return 0;
124 	}
125 	f = fopen(path, "r");
126 	if (!f) {
127 		rte_errno = errno;
128 		return 0;
129 	}
130 	ret = fscanf(f, NETVSC_CLASS_ID "%n", &len);
131 	if (ret == EOF)
132 		rte_errno = errno;
133 	ret = len == (int)strlen(NETVSC_CLASS_ID);
134 	fclose(f);
135 	return ret;
136 }
137 
138 /**
139  * Iterate over system network interfaces.
140  *
141  * This function runs a given callback function for each netdevice found on
142  * the system.
143  *
144  * @param func
145  *   Callback function pointer. List traversal is aborted when this function
146  *   returns a nonzero value.
147  * @param is_netvsc
148  *   Indicates the device type to iterate - netvsc or non-netvsc.
149  * @param ...
150  *   Variable parameter list passed as @p va_list to @p func.
151  *
152  * @return
153  *   0 when the entire list is traversed successfully, a negative error code
154  *   in case or failure, or the nonzero value returned by @p func when list
155  *   traversal is aborted.
156  */
157 static int
158 vdev_netvsc_foreach_iface(int (*func)(const struct if_nameindex *iface,
159 				      const struct rte_ether_addr *eth_addr,
160 				      va_list ap), int is_netvsc, ...)
161 {
162 	struct if_nameindex *iface = if_nameindex();
163 	int s = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
164 	unsigned int i;
165 	int ret = 0;
166 
167 	if (!iface) {
168 		ret = -ENOBUFS;
169 		DRV_LOG(ERR, "cannot retrieve system network interfaces");
170 		goto error;
171 	}
172 	if (s == -1) {
173 		ret = -errno;
174 		DRV_LOG(ERR, "cannot open socket: %s", rte_strerror(errno));
175 		goto error;
176 	}
177 	for (i = 0; iface[i].if_name; ++i) {
178 		int is_netvsc_ret;
179 		struct ifreq req;
180 		struct rte_ether_addr eth_addr;
181 		va_list ap;
182 
183 		is_netvsc_ret = vdev_netvsc_iface_is_netvsc(&iface[i]) ? 1 : 0;
184 		if (is_netvsc ^ is_netvsc_ret)
185 			continue;
186 		strlcpy(req.ifr_name, iface[i].if_name, sizeof(req.ifr_name));
187 		if (ioctl(s, SIOCGIFHWADDR, &req) == -1) {
188 			DRV_LOG(WARNING, "cannot retrieve information about"
189 					 " interface \"%s\": %s",
190 					 req.ifr_name, rte_strerror(errno));
191 			continue;
192 		}
193 		if (req.ifr_hwaddr.sa_family != ARPHRD_ETHER)
194 			continue;
195 		memcpy(eth_addr.addr_bytes, req.ifr_hwaddr.sa_data,
196 		       RTE_DIM(eth_addr.addr_bytes));
197 		va_start(ap, is_netvsc);
198 		ret = func(&iface[i], &eth_addr, ap);
199 		va_end(ap);
200 		if (ret)
201 			break;
202 	}
203 error:
204 	if (s != -1)
205 		close(s);
206 	if (iface)
207 		if_freenameindex(iface);
208 	return ret;
209 }
210 
211 /**
212  * Determine if a network interface has a route.
213  *
214  * @param[in] name
215  *   Network device name.
216  * @param[in] family
217  *   Address family: AF_INET for IPv4 or AF_INET6 for IPv6.
218  *
219  * @return
220  *   1 when interface has a route, negative errno value in case of error and
221  *   0 otherwise.
222  */
223 static int
224 vdev_netvsc_has_route(const struct if_nameindex *iface,
225 		      const unsigned char family)
226 {
227 	/*
228 	 * The implementation can be simpler by getifaddrs() function usage but
229 	 * it works for IPv6 only starting from glibc 2.3.3.
230 	 */
231 	char buf[4096];
232 	int len;
233 	int ret = 0;
234 	int res;
235 	int sock;
236 	struct nlmsghdr *retmsg = (struct nlmsghdr *)buf;
237 	struct sockaddr_nl sa;
238 	struct {
239 		struct nlmsghdr nlhdr;
240 		struct ifaddrmsg addrmsg;
241 	} msg;
242 
243 	if (!iface || (family != AF_INET && family != AF_INET6)) {
244 		DRV_LOG(ERR, "%s", rte_strerror(EINVAL));
245 		return -EINVAL;
246 	}
247 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
248 	if (sock == -1) {
249 		DRV_LOG(ERR, "cannot open socket: %s", rte_strerror(errno));
250 		return -errno;
251 	}
252 	memset(&sa, 0, sizeof(sa));
253 	sa.nl_family = AF_NETLINK;
254 	sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR;
255 	res = bind(sock, (struct sockaddr *)&sa, sizeof(sa));
256 	if (res == -1) {
257 		ret = -errno;
258 		DRV_LOG(ERR, "cannot bind socket: %s", rte_strerror(errno));
259 		goto close;
260 	}
261 	memset(&msg, 0, sizeof(msg));
262 	msg.nlhdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
263 	msg.nlhdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
264 	msg.nlhdr.nlmsg_type = RTM_GETADDR;
265 	msg.nlhdr.nlmsg_pid = getpid();
266 	msg.addrmsg.ifa_family = family;
267 	msg.addrmsg.ifa_index = iface->if_index;
268 	res = send(sock, &msg, msg.nlhdr.nlmsg_len, 0);
269 	if (res == -1) {
270 		ret = -errno;
271 		DRV_LOG(ERR, "cannot send socket message: %s",
272 			rte_strerror(errno));
273 		goto close;
274 	}
275 	memset(buf, 0, sizeof(buf));
276 	len = recv(sock, buf, sizeof(buf), 0);
277 	if (len == -1) {
278 		ret = -errno;
279 		DRV_LOG(ERR, "cannot receive socket message: %s",
280 			rte_strerror(errno));
281 		goto close;
282 	}
283 	while (NLMSG_OK(retmsg, (unsigned int)len)) {
284 		struct ifaddrmsg *retaddr =
285 				(struct ifaddrmsg *)NLMSG_DATA(retmsg);
286 
287 		if (retaddr->ifa_family == family &&
288 		    retaddr->ifa_index == iface->if_index) {
289 			struct rtattr *retrta = IFA_RTA(retaddr);
290 			int attlen = IFA_PAYLOAD(retmsg);
291 
292 			while (RTA_OK(retrta, attlen)) {
293 				if (retrta->rta_type == IFA_ADDRESS) {
294 					ret = 1;
295 					DRV_LOG(DEBUG, "interface %s has IP",
296 						iface->if_name);
297 					goto close;
298 				}
299 				retrta = RTA_NEXT(retrta, attlen);
300 			}
301 		}
302 		retmsg = NLMSG_NEXT(retmsg, len);
303 	}
304 close:
305 	close(sock);
306 	return ret;
307 }
308 
309 /**
310  * Retrieve network interface data from sysfs symbolic link.
311  *
312  * @param[out] buf
313  *   Output data buffer.
314  * @param size
315  *   Output buffer size.
316  * @param[in] if_name
317  *   Netdevice name.
318  * @param[in] relpath
319  *   Symbolic link path relative to netdevice sysfs entry.
320  *
321  * @return
322  *   0 on success, a negative error code otherwise.
323  */
324 static int
325 vdev_netvsc_sysfs_readlink(char *buf, size_t size, const char *if_name,
326 			   const char *relpath)
327 {
328 	struct vdev_netvsc_ctx *ctx;
329 	char in[RTE_MAX(sizeof(ctx->yield), 256u)];
330 	int ret;
331 
332 	ret = snprintf(in, sizeof(in), "/sys/class/net/%s/%s",
333 		       if_name, relpath);
334 	if (ret == -1 || (size_t)ret >= sizeof(in))
335 		return -ENOBUFS;
336 	ret = readlink(in, buf, size);
337 	if (ret == -1)
338 		return -errno;
339 	if ((size_t)ret >= size - 1)
340 		return -ENOBUFS;
341 	buf[ret] = '\0';
342 	return 0;
343 }
344 
345 /**
346  * Probe a network interface to associate with vdev_netvsc context.
347  *
348  * This function determines if the network device matches the properties of
349  * the NetVSC interface associated with the vdev_netvsc context and
350  * communicates its bus address to the fail-safe PMD instance if so.
351  *
352  * It is normally used with vdev_netvsc_foreach_iface().
353  *
354  * @param[in] iface
355  *   Pointer to netdevice description structure (name and index).
356  * @param[in] eth_addr
357  *   MAC address associated with @p iface.
358  * @param ap
359  *   Variable arguments list comprising:
360  *
361  *   - struct vdev_netvsc_ctx *ctx:
362  *     Context to associate network interface with.
363  *
364  * @return
365  *   A nonzero value when interface matches, 0 otherwise or in case of
366  *   error.
367  */
368 static int
369 vdev_netvsc_device_probe(const struct if_nameindex *iface,
370 		    const struct rte_ether_addr *eth_addr,
371 		    va_list ap)
372 {
373 	struct vdev_netvsc_ctx *ctx = va_arg(ap, struct vdev_netvsc_ctx *);
374 	char buf[RTE_MAX(sizeof(ctx->yield), 256u)];
375 	const char *addr;
376 	size_t len;
377 	int ret;
378 
379 	/* Skip non-matching or unwanted NetVSC interfaces. */
380 	if (ctx->if_index == iface->if_index) {
381 		if (!strcmp(ctx->if_name, iface->if_name))
382 			return 0;
383 		DRV_LOG(DEBUG,
384 			"NetVSC interface \"%s\" (index %u) renamed \"%s\"",
385 			ctx->if_name, ctx->if_index, iface->if_name);
386 		strlcpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
387 		return 0;
388 	}
389 	if (!rte_is_same_ether_addr(eth_addr, &ctx->if_addr))
390 		return 0;
391 	/* Look for associated PCI device. */
392 	ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name,
393 					 "device/subsystem");
394 	if (ret)
395 		return 0;
396 	addr = strrchr(buf, '/');
397 	addr = addr ? addr + 1 : buf;
398 	if (strcmp(addr, "pci"))
399 		return 0;
400 	ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name,
401 					 "device");
402 	if (ret)
403 		return 0;
404 	addr = strrchr(buf, '/');
405 	addr = addr ? addr + 1 : buf;
406 	len = strlen(addr);
407 	if (!len)
408 		return 0;
409 	/* Send PCI device argument to fail-safe PMD instance. */
410 	if (strcmp(addr, ctx->yield))
411 		DRV_LOG(DEBUG, "associating PCI device \"%s\" with NetVSC"
412 			" interface \"%s\" (index %u)", addr, ctx->if_name,
413 			ctx->if_index);
414 	memmove(buf, addr, len + 1);
415 	addr = buf;
416 	buf[len] = '\n';
417 	ret = write(ctx->pipe[1], addr, len + 1);
418 	buf[len] = '\0';
419 	if (ret == -1) {
420 		if (errno == EINTR || errno == EAGAIN)
421 			return 1;
422 		DRV_LOG(WARNING, "cannot associate PCI device name \"%s\" with"
423 			" interface \"%s\": %s", addr, ctx->if_name,
424 			rte_strerror(errno));
425 		return 1;
426 	}
427 	if ((size_t)ret != len + 1) {
428 		/*
429 		 * Attempt to override previous partial write, no need to
430 		 * recover if that fails.
431 		 */
432 		ret = write(ctx->pipe[1], "\n", 1);
433 		(void)ret;
434 		return 1;
435 	}
436 	fsync(ctx->pipe[1]);
437 	memcpy(ctx->yield, addr, len + 1);
438 	return 1;
439 }
440 
441 /**
442  * Alarm callback that regularly probes system network interfaces.
443  *
444  * This callback runs at a frequency determined by VDEV_NETVSC_PROBE_MS as
445  * long as an vdev_netvsc context instance exists.
446  *
447  * @param arg
448  *   Ignored.
449  */
450 static void
451 vdev_netvsc_alarm(__rte_unused void *arg)
452 {
453 	struct vdev_netvsc_ctx *ctx;
454 	int ret;
455 
456 	LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry) {
457 		ret = vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0,
458 		      ctx);
459 		if (ret < 0)
460 			break;
461 	}
462 	if (!vdev_netvsc_ctx_count)
463 		return;
464 	ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
465 				vdev_netvsc_alarm, NULL);
466 	if (ret < 0) {
467 		DRV_LOG(ERR, "unable to reschedule alarm callback: %s",
468 			rte_strerror(-ret));
469 	}
470 }
471 
472 /**
473  * Probe a NetVSC interface to generate a vdev_netvsc context from.
474  *
475  * This function instantiates vdev_netvsc contexts either for all NetVSC
476  * devices found on the system or only a subset provided as device
477  * arguments.
478  *
479  * It is normally used with vdev_netvsc_foreach_iface().
480  *
481  * @param[in] iface
482  *   Pointer to netdevice description structure (name and index).
483  * @param[in] eth_addr
484  *   MAC address associated with @p iface.
485  * @param ap
486  *   Variable arguments list comprising:
487  *
488  *   - const char *name:
489  *     Name associated with current driver instance.
490  *
491  *   - struct rte_kvargs *kvargs:
492  *     Device arguments provided to current driver instance.
493  *
494  *   - int force:
495  *     Accept specified interface even if not detected as NetVSC.
496  *
497  *   - unsigned int specified:
498  *     Number of specific netdevices provided as device arguments.
499  *
500  *   - unsigned int *matched:
501  *     The number of specified netdevices matched by this function.
502  *
503  * @return
504  *   A nonzero value when interface matches, 0 otherwise or in case of
505  *   error.
506  */
507 static int
508 vdev_netvsc_netvsc_probe(const struct if_nameindex *iface,
509 			 const struct rte_ether_addr *eth_addr,
510 			 va_list ap)
511 {
512 	const char *name = va_arg(ap, const char *);
513 	struct rte_kvargs *kvargs = va_arg(ap, struct rte_kvargs *);
514 	unsigned int specified = va_arg(ap, unsigned int);
515 	unsigned int *matched = va_arg(ap, unsigned int *);
516 	unsigned int i;
517 	struct vdev_netvsc_ctx *ctx;
518 	int ret;
519 
520 	/* Probe all interfaces when none are specified. */
521 	if (specified) {
522 		for (i = 0; i != kvargs->count; ++i) {
523 			const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
524 
525 			if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE)) {
526 				if (!strcmp(pair->value, iface->if_name))
527 					break;
528 			} else if (!strcmp(pair->key, VDEV_NETVSC_ARG_MAC)) {
529 				struct rte_ether_addr tmp;
530 
531 				if (rte_ether_unformat_addr(pair->value, &tmp) != 0) {
532 					DRV_LOG(ERR,
533 						"invalid MAC address format"
534 						" \"%s\"",
535 						pair->value);
536 					return -EINVAL;
537 				}
538 				if (rte_is_same_ether_addr(eth_addr, &tmp))
539 					break;
540 			}
541 		}
542 		if (i == kvargs->count)
543 			return 0;
544 		++(*matched);
545 	}
546 	/* Weed out interfaces already handled. */
547 	LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry)
548 		if (ctx->if_index == iface->if_index)
549 			break;
550 	if (ctx) {
551 		if (!specified)
552 			return 0;
553 		DRV_LOG(WARNING,
554 			"interface \"%s\" (index %u) is already handled,"
555 			" skipping",
556 			iface->if_name, iface->if_index);
557 		return 0;
558 	}
559 	/* Routed NetVSC should not be probed. */
560 	if (vdev_netvsc_has_route(iface, AF_INET) ||
561 	    vdev_netvsc_has_route(iface, AF_INET6)) {
562 		if (!specified)
563 			return 0;
564 		DRV_LOG(WARNING, "probably using routed NetVSC interface \"%s\""
565 			" (index %u)", iface->if_name, iface->if_index);
566 	}
567 	/* Create interface context. */
568 	ctx = calloc(1, sizeof(*ctx));
569 	if (!ctx) {
570 		ret = -errno;
571 		DRV_LOG(ERR, "cannot allocate context for interface \"%s\": %s",
572 			iface->if_name, rte_strerror(errno));
573 		goto error;
574 	}
575 	ctx->id = vdev_netvsc_ctx_count;
576 	strlcpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
577 	ctx->if_index = iface->if_index;
578 	ctx->if_addr = *eth_addr;
579 	ctx->pipe[0] = -1;
580 	ctx->pipe[1] = -1;
581 	ctx->yield[0] = '\0';
582 	if (pipe(ctx->pipe) == -1) {
583 		ret = -errno;
584 		DRV_LOG(ERR,
585 			"cannot allocate control pipe for interface \"%s\": %s",
586 			ctx->if_name, rte_strerror(errno));
587 		goto error;
588 	}
589 	for (i = 0; i != RTE_DIM(ctx->pipe); ++i) {
590 		int flf = fcntl(ctx->pipe[i], F_GETFL);
591 
592 		if (flf != -1 &&
593 		    fcntl(ctx->pipe[i], F_SETFL, flf | O_NONBLOCK) != -1)
594 			continue;
595 		ret = -errno;
596 		DRV_LOG(ERR, "cannot toggle non-blocking flag on control file"
597 			" descriptor #%u (%d): %s", i, ctx->pipe[i],
598 			rte_strerror(errno));
599 		goto error;
600 	}
601 	/* Generate virtual device name and arguments. */
602 	i = 0;
603 	ret = snprintf(ctx->name, sizeof(ctx->name), "%s_id%u",
604 		       name, ctx->id);
605 	if (ret == -1 || (size_t)ret >= sizeof(ctx->name))
606 		++i;
607 	ret = snprintf(ctx->devname, sizeof(ctx->devname), "net_failsafe_vsc%u",
608 		       ctx->id);
609 	if (ret == -1 || (size_t)ret >= sizeof(ctx->devname))
610 		++i;
611 	ret = snprintf(ctx->devargs, sizeof(ctx->devargs),
612 		       "fd(%d),dev(net_tap_vsc%u,remote=%s)",
613 		       ctx->pipe[0], ctx->id, ctx->if_name);
614 	if (ret == -1 || (size_t)ret >= sizeof(ctx->devargs))
615 		++i;
616 	if (i) {
617 		ret = -ENOBUFS;
618 		DRV_LOG(ERR, "generated virtual device name or argument list"
619 			" too long for interface \"%s\"", ctx->if_name);
620 		goto error;
621 	}
622 	/* Request virtual device generation. */
623 	DRV_LOG(DEBUG, "generating virtual device \"%s\" with arguments \"%s\"",
624 		ctx->devname, ctx->devargs);
625 	vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0, ctx);
626 	ret = rte_eal_hotplug_add("vdev", ctx->devname, ctx->devargs);
627 	if (ret < 0)
628 		goto error;
629 	LIST_INSERT_HEAD(&vdev_netvsc_ctx_list, ctx, entry);
630 	++vdev_netvsc_ctx_count;
631 	DRV_LOG(DEBUG, "added NetVSC interface \"%s\" to context list",
632 		ctx->if_name);
633 	return 0;
634 error:
635 	if (ctx)
636 		vdev_netvsc_ctx_destroy(ctx);
637 	return ret;
638 }
639 
640 /**
641  * Probe NetVSC interfaces.
642  *
643  * This function probes system netdevices according to the specified device
644  * arguments and starts a periodic alarm callback to notify the resulting
645  * fail-safe PMD instances of their sub-devices whereabouts.
646  *
647  * @param dev
648  *   Virtual device context for driver instance.
649  *
650  * @return
651  *    Always 0, even in case of errors.
652  */
653 static int
654 vdev_netvsc_vdev_probe(struct rte_vdev_device *dev)
655 {
656 	static const char *const vdev_netvsc_arg[] = {
657 		VDEV_NETVSC_ARG_IFACE,
658 		VDEV_NETVSC_ARG_MAC,
659 		VDEV_NETVSC_ARG_FORCE,
660 		VDEV_NETVSC_ARG_IGNORE,
661 		NULL,
662 	};
663 	const char *name = rte_vdev_device_name(dev);
664 	const char *args = rte_vdev_device_args(dev);
665 	struct rte_kvargs *kvargs = rte_kvargs_parse(args ? args : "",
666 						     vdev_netvsc_arg);
667 	unsigned int specified = 0;
668 	unsigned int matched = 0;
669 	int force = 0;
670 	int ignore = 0;
671 	unsigned int i;
672 	int ret;
673 
674 	DRV_LOG(DEBUG, "invoked as \"%s\", using arguments \"%s\"", name, args);
675 	if (!kvargs) {
676 		DRV_LOG(ERR, "cannot parse arguments list");
677 		goto error;
678 	}
679 	for (i = 0; i != kvargs->count; ++i) {
680 		const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
681 
682 		if (!strcmp(pair->key, VDEV_NETVSC_ARG_FORCE))
683 			force = !!atoi(pair->value);
684 		else if (!strcmp(pair->key, VDEV_NETVSC_ARG_IGNORE))
685 			ignore = !!atoi(pair->value);
686 		else if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE) ||
687 			 !strcmp(pair->key, VDEV_NETVSC_ARG_MAC))
688 			++specified;
689 	}
690 	if (ignore) {
691 		if (kvargs)
692 			rte_kvargs_free(kvargs);
693 		return 0;
694 	}
695 	if (specified > 1) {
696 		DRV_LOG(ERR, "More than one way used to specify the netvsc"
697 			" device.");
698 		goto error;
699 	}
700 	rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
701 	/* Gather interfaces. */
702 	ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 1, name,
703 					kvargs, specified, &matched);
704 	if (ret < 0)
705 		goto error;
706 	if (specified && matched < specified) {
707 		if (!force) {
708 			DRV_LOG(ERR, "Cannot find the specified netvsc device");
709 			goto error;
710 		}
711 		/* Try to force probing on non-netvsc specified device. */
712 		if (vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 0, name,
713 					      kvargs, specified, &matched) < 0)
714 			goto error;
715 		if (matched < specified) {
716 			DRV_LOG(ERR, "Cannot find the specified device");
717 			goto error;
718 		}
719 		DRV_LOG(WARNING, "non-netvsc device was probed as netvsc");
720 	}
721 	ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
722 				vdev_netvsc_alarm, NULL);
723 	if (ret < 0) {
724 		DRV_LOG(ERR, "unable to schedule alarm callback: %s",
725 			rte_strerror(-ret));
726 		goto error;
727 	}
728 error:
729 	if (kvargs)
730 		rte_kvargs_free(kvargs);
731 	++vdev_netvsc_ctx_inst;
732 	return 0;
733 }
734 
735 /**
736  * Remove driver instance.
737  *
738  * The alarm callback and underlying vdev_netvsc context instances are only
739  * destroyed after the last PMD instance is removed.
740  *
741  * @param dev
742  *   Virtual device context for driver instance.
743  *
744  * @return
745  *   Always 0.
746  */
747 static int
748 vdev_netvsc_vdev_remove(__rte_unused struct rte_vdev_device *dev)
749 {
750 	if (--vdev_netvsc_ctx_inst)
751 		return 0;
752 	rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
753 	while (!LIST_EMPTY(&vdev_netvsc_ctx_list)) {
754 		struct vdev_netvsc_ctx *ctx = LIST_FIRST(&vdev_netvsc_ctx_list);
755 
756 		LIST_REMOVE(ctx, entry);
757 		--vdev_netvsc_ctx_count;
758 		vdev_netvsc_ctx_destroy(ctx);
759 	}
760 	return 0;
761 }
762 
763 /** Virtual device descriptor. */
764 static struct rte_vdev_driver vdev_netvsc_vdev = {
765 	.probe = vdev_netvsc_vdev_probe,
766 	.remove = vdev_netvsc_vdev_remove,
767 };
768 
769 RTE_PMD_REGISTER_VDEV(VDEV_NETVSC_DRIVER, vdev_netvsc_vdev);
770 RTE_PMD_REGISTER_ALIAS(VDEV_NETVSC_DRIVER, eth_vdev_netvsc);
771 RTE_PMD_REGISTER_PARAM_STRING(net_vdev_netvsc,
772 			      VDEV_NETVSC_ARG_IFACE "=<string> "
773 			      VDEV_NETVSC_ARG_MAC "=<string> "
774 			      VDEV_NETVSC_ARG_FORCE "=<int> "
775 			      VDEV_NETVSC_ARG_IGNORE "=<int>");
776 
777 /** Initialize driver log type. */
778 RTE_INIT(vdev_netvsc_init_log)
779 {
780 	vdev_netvsc_logtype = rte_log_register("pmd.net.vdev_netvsc");
781 	if (vdev_netvsc_logtype >= 0)
782 		rte_log_set_level(vdev_netvsc_logtype, RTE_LOG_NOTICE);
783 }
784 
785 /** Compare function for vdev find device operation. */
786 static int
787 vdev_netvsc_cmp_rte_device(const struct rte_device *dev1,
788 			   __rte_unused const void *_dev2)
789 {
790 	return strncmp(dev1->devargs->name, VDEV_NETVSC_DRIVER_NAME,
791 		       VDEV_NETVSC_DRIVER_NAME_LEN);
792 }
793 
794 /**
795  * A callback called by vdev bus scan function to ensure this driver probing
796  * automatically in Hyper-V VM system unless it already exists in the
797  * devargs list.
798  */
799 static void
800 vdev_netvsc_scan_callback(__rte_unused void *arg)
801 {
802 	struct rte_device *dev;
803 	struct rte_devargs *devargs;
804 	struct rte_bus *vbus = rte_bus_find_by_name("vdev");
805 
806 	RTE_EAL_DEVARGS_FOREACH("vdev", devargs)
807 		if (!strncmp(devargs->name, VDEV_NETVSC_DRIVER_NAME,
808 			     VDEV_NETVSC_DRIVER_NAME_LEN))
809 			return;
810 
811 	dev = vbus->find_device(NULL, vdev_netvsc_cmp_rte_device,
812 				VDEV_NETVSC_DRIVER_NAME);
813 	if (dev)
814 		return;
815 	if (rte_devargs_add(RTE_DEVTYPE_VIRTUAL, VDEV_NETVSC_DRIVER_NAME))
816 		DRV_LOG(ERR, "unable to add netvsc devargs.");
817 }
818 
819 /** Initialize the custom scan. */
820 RTE_INIT(vdev_netvsc_custom_scan_add)
821 {
822 	if (rte_hypervisor_get() == RTE_HYPERVISOR_HYPERV)
823 		rte_vdev_add_custom_scan(vdev_netvsc_scan_callback, NULL);
824 }
825