xref: /dpdk/drivers/net/vdev_netvsc/vdev_netvsc.c (revision 2e4d2e563f23930b06c24b7bc543bf04321d81f7)
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_config.h>
31 #include <rte_dev.h>
32 #include <rte_errno.h>
33 #include <rte_ethdev.h>
34 #include <rte_ether.h>
35 #include <rte_hypervisor.h>
36 #include <rte_kvargs.h>
37 #include <rte_log.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_ARG_IFACE "iface"
42 #define VDEV_NETVSC_ARG_MAC "mac"
43 #define VDEV_NETVSC_ARG_FORCE "force"
44 #define VDEV_NETVSC_ARG_IGNORE "ignore"
45 #define VDEV_NETVSC_PROBE_MS 1000
46 
47 #define NETVSC_CLASS_ID "{f8615163-df3e-46c5-913f-f2d2f965ed0e}"
48 #define NETVSC_MAX_ROUTE_LINE_SIZE 300
49 
50 #define DRV_LOG(level, ...) \
51 	rte_log(RTE_LOG_ ## level, \
52 		vdev_netvsc_logtype, \
53 		RTE_FMT(VDEV_NETVSC_DRIVER_NAME ": " \
54 			RTE_FMT_HEAD(__VA_ARGS__,) "\n", \
55 		RTE_FMT_TAIL(__VA_ARGS__,)))
56 
57 /** Driver-specific log messages type. */
58 static int vdev_netvsc_logtype;
59 
60 /** Context structure for a vdev_netvsc instance. */
61 struct vdev_netvsc_ctx {
62 	LIST_ENTRY(vdev_netvsc_ctx) entry; /**< Next entry in list. */
63 	unsigned int id;		   /**< Unique ID. */
64 	char name[64];			   /**< Unique name. */
65 	char devname[64];		   /**< Fail-safe instance name. */
66 	char devargs[256];		   /**< Fail-safe device arguments. */
67 	char if_name[IF_NAMESIZE];	   /**< NetVSC netdevice name. */
68 	unsigned int if_index;		   /**< NetVSC netdevice index. */
69 	struct ether_addr if_addr;	   /**< NetVSC MAC address. */
70 	int pipe[2];			   /**< Fail-safe communication pipe. */
71 	char yield[256];		   /**< PCI sub-device arguments. */
72 };
73 
74 /** Context list is common to all driver instances. */
75 static LIST_HEAD(, vdev_netvsc_ctx) vdev_netvsc_ctx_list =
76 	LIST_HEAD_INITIALIZER(vdev_netvsc_ctx_list);
77 
78 /** Number of entries in context list. */
79 static unsigned int vdev_netvsc_ctx_count;
80 
81 /** Number of driver instances relying on context list. */
82 static unsigned int vdev_netvsc_ctx_inst;
83 
84 /**
85  * Destroy a vdev_netvsc context instance.
86  *
87  * @param ctx
88  *   Context to destroy.
89  */
90 static void
91 vdev_netvsc_ctx_destroy(struct vdev_netvsc_ctx *ctx)
92 {
93 	if (ctx->pipe[0] != -1)
94 		close(ctx->pipe[0]);
95 	if (ctx->pipe[1] != -1)
96 		close(ctx->pipe[1]);
97 	free(ctx);
98 }
99 
100 /**
101  * Determine if a network interface is NetVSC.
102  *
103  * @param[in] iface
104  *   Pointer to netdevice description structure (name and index).
105  *
106  * @return
107  *   A nonzero value when interface is detected as NetVSC. In case of error,
108  *   rte_errno is updated and 0 returned.
109  */
110 static int
111 vdev_netvsc_iface_is_netvsc(const struct if_nameindex *iface)
112 {
113 	static const char temp[] = "/sys/class/net/%s/device/class_id";
114 	char path[sizeof(temp) + IF_NAMESIZE];
115 	FILE *f;
116 	int ret;
117 	int len = 0;
118 
119 	ret = snprintf(path, sizeof(path), temp, iface->if_name);
120 	if (ret == -1 || (size_t)ret >= sizeof(path)) {
121 		rte_errno = ENOBUFS;
122 		return 0;
123 	}
124 	f = fopen(path, "r");
125 	if (!f) {
126 		rte_errno = errno;
127 		return 0;
128 	}
129 	ret = fscanf(f, NETVSC_CLASS_ID "%n", &len);
130 	if (ret == EOF)
131 		rte_errno = errno;
132 	ret = len == (int)strlen(NETVSC_CLASS_ID);
133 	fclose(f);
134 	return ret;
135 }
136 
137 /**
138  * Iterate over system network interfaces.
139  *
140  * This function runs a given callback function for each netdevice found on
141  * the system.
142  *
143  * @param func
144  *   Callback function pointer. List traversal is aborted when this function
145  *   returns a nonzero value.
146  * @param is_netvsc
147  *   Indicates the device type to iterate - netvsc or non-netvsc.
148  * @param ...
149  *   Variable parameter list passed as @p va_list to @p func.
150  *
151  * @return
152  *   0 when the entire list is traversed successfully, a negative error code
153  *   in case or failure, or the nonzero value returned by @p func when list
154  *   traversal is aborted.
155  */
156 static int
157 vdev_netvsc_foreach_iface(int (*func)(const struct if_nameindex *iface,
158 				      const struct ether_addr *eth_addr,
159 				      va_list ap), int is_netvsc, ...)
160 {
161 	struct if_nameindex *iface = if_nameindex();
162 	int s = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
163 	unsigned int i;
164 	int ret = 0;
165 
166 	if (!iface) {
167 		ret = -ENOBUFS;
168 		DRV_LOG(ERR, "cannot retrieve system network interfaces");
169 		goto error;
170 	}
171 	if (s == -1) {
172 		ret = -errno;
173 		DRV_LOG(ERR, "cannot open socket: %s", rte_strerror(errno));
174 		goto error;
175 	}
176 	for (i = 0; iface[i].if_name; ++i) {
177 		int is_netvsc_ret;
178 		struct ifreq req;
179 		struct ether_addr eth_addr;
180 		va_list ap;
181 
182 		is_netvsc_ret = vdev_netvsc_iface_is_netvsc(&iface[i]) ? 1 : 0;
183 		if (is_netvsc ^ is_netvsc_ret)
184 			continue;
185 		strncpy(req.ifr_name, iface[i].if_name, sizeof(req.ifr_name));
186 		if (ioctl(s, SIOCGIFHWADDR, &req) == -1) {
187 			DRV_LOG(WARNING, "cannot retrieve information about"
188 					 " interface \"%s\": %s",
189 					 req.ifr_name, rte_strerror(errno));
190 			continue;
191 		}
192 		if (req.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
193 			DRV_LOG(DEBUG, "interface %s is non-ethernet device",
194 				req.ifr_name);
195 			continue;
196 		}
197 		memcpy(eth_addr.addr_bytes, req.ifr_hwaddr.sa_data,
198 		       RTE_DIM(eth_addr.addr_bytes));
199 		va_start(ap, is_netvsc);
200 		ret = func(&iface[i], &eth_addr, ap);
201 		va_end(ap);
202 		if (ret)
203 			break;
204 	}
205 error:
206 	if (s != -1)
207 		close(s);
208 	if (iface)
209 		if_freenameindex(iface);
210 	return ret;
211 }
212 
213 /**
214  * Determine if a network interface has a route.
215  *
216  * @param[in] name
217  *   Network device name.
218  * @param[in] family
219  *   Address family: AF_INET for IPv4 or AF_INET6 for IPv6.
220  *
221  * @return
222  *   1 when interface has a route, negative errno value in case of error and
223  *   0 otherwise.
224  */
225 static int
226 vdev_netvsc_has_route(const struct if_nameindex *iface,
227 		      const unsigned char family)
228 {
229 	/*
230 	 * The implementation can be simpler by getifaddrs() function usage but
231 	 * it works for IPv6 only starting from glibc 2.3.3.
232 	 */
233 	char buf[4096];
234 	int len;
235 	int ret = 0;
236 	int res;
237 	int sock;
238 	struct nlmsghdr *retmsg = (struct nlmsghdr *)buf;
239 	struct sockaddr_nl sa;
240 	struct {
241 		struct nlmsghdr nlhdr;
242 		struct ifaddrmsg addrmsg;
243 	} msg;
244 
245 	if (!iface || (family != AF_INET && family != AF_INET6)) {
246 		DRV_LOG(ERR, "%s", rte_strerror(EINVAL));
247 		return -EINVAL;
248 	}
249 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
250 	if (sock == -1) {
251 		DRV_LOG(ERR, "cannot open socket: %s", rte_strerror(errno));
252 		return -errno;
253 	}
254 	memset(&sa, 0, sizeof(sa));
255 	sa.nl_family = AF_NETLINK;
256 	sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR;
257 	res = bind(sock, (struct sockaddr *)&sa, sizeof(sa));
258 	if (res == -1) {
259 		ret = -errno;
260 		DRV_LOG(ERR, "cannot bind socket: %s", rte_strerror(errno));
261 		goto close;
262 	}
263 	memset(&msg, 0, sizeof(msg));
264 	msg.nlhdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
265 	msg.nlhdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
266 	msg.nlhdr.nlmsg_type = RTM_GETADDR;
267 	msg.nlhdr.nlmsg_pid = getpid();
268 	msg.addrmsg.ifa_family = family;
269 	msg.addrmsg.ifa_index = iface->if_index;
270 	res = send(sock, &msg, msg.nlhdr.nlmsg_len, 0);
271 	if (res == -1) {
272 		ret = -errno;
273 		DRV_LOG(ERR, "cannot send socket message: %s",
274 			rte_strerror(errno));
275 		goto close;
276 	}
277 	memset(buf, 0, sizeof(buf));
278 	len = recv(sock, buf, sizeof(buf), 0);
279 	if (len == -1) {
280 		ret = -errno;
281 		DRV_LOG(ERR, "cannot receive socket message: %s",
282 			rte_strerror(errno));
283 		goto close;
284 	}
285 	while (NLMSG_OK(retmsg, (unsigned int)len)) {
286 		struct ifaddrmsg *retaddr =
287 				(struct ifaddrmsg *)NLMSG_DATA(retmsg);
288 
289 		if (retaddr->ifa_family == family &&
290 		    retaddr->ifa_index == iface->if_index) {
291 			struct rtattr *retrta = IFA_RTA(retaddr);
292 			int attlen = IFA_PAYLOAD(retmsg);
293 
294 			while (RTA_OK(retrta, attlen)) {
295 				if (retrta->rta_type == IFA_ADDRESS) {
296 					ret = 1;
297 					DRV_LOG(DEBUG, "interface %s has IP",
298 						iface->if_name);
299 					goto close;
300 				}
301 				retrta = RTA_NEXT(retrta, attlen);
302 			}
303 		}
304 		retmsg = NLMSG_NEXT(retmsg, len);
305 	}
306 close:
307 	close(sock);
308 	return ret;
309 }
310 
311 /**
312  * Retrieve network interface data from sysfs symbolic link.
313  *
314  * @param[out] buf
315  *   Output data buffer.
316  * @param size
317  *   Output buffer size.
318  * @param[in] if_name
319  *   Netdevice name.
320  * @param[in] relpath
321  *   Symbolic link path relative to netdevice sysfs entry.
322  *
323  * @return
324  *   0 on success, a negative error code otherwise.
325  */
326 static int
327 vdev_netvsc_sysfs_readlink(char *buf, size_t size, const char *if_name,
328 			   const char *relpath)
329 {
330 	struct vdev_netvsc_ctx *ctx;
331 	char in[RTE_MAX(sizeof(ctx->yield), 256u)];
332 	int ret;
333 
334 	ret = snprintf(in, sizeof(in) - 1, "/sys/class/net/%s/%s",
335 		       if_name, relpath);
336 	if (ret == -1 || (size_t)ret >= sizeof(in))
337 		return -ENOBUFS;
338 	ret = readlink(in, buf, size);
339 	if (ret == -1)
340 		return -errno;
341 	if ((size_t)ret >= size - 1)
342 		return -ENOBUFS;
343 	buf[ret] = '\0';
344 	return 0;
345 }
346 
347 /**
348  * Probe a network interface to associate with vdev_netvsc context.
349  *
350  * This function determines if the network device matches the properties of
351  * the NetVSC interface associated with the vdev_netvsc context and
352  * communicates its bus address to the fail-safe PMD instance if so.
353  *
354  * It is normally used with vdev_netvsc_foreach_iface().
355  *
356  * @param[in] iface
357  *   Pointer to netdevice description structure (name and index).
358  * @param[in] eth_addr
359  *   MAC address associated with @p iface.
360  * @param ap
361  *   Variable arguments list comprising:
362  *
363  *   - struct vdev_netvsc_ctx *ctx:
364  *     Context to associate network interface with.
365  *
366  * @return
367  *   A nonzero value when interface matches, 0 otherwise or in case of
368  *   error.
369  */
370 static int
371 vdev_netvsc_device_probe(const struct if_nameindex *iface,
372 		    const struct ether_addr *eth_addr,
373 		    va_list ap)
374 {
375 	struct vdev_netvsc_ctx *ctx = va_arg(ap, struct vdev_netvsc_ctx *);
376 	char buf[RTE_MAX(sizeof(ctx->yield), 256u)];
377 	const char *addr;
378 	size_t len;
379 	int ret;
380 
381 	/* Skip non-matching or unwanted NetVSC interfaces. */
382 	if (ctx->if_index == iface->if_index) {
383 		if (!strcmp(ctx->if_name, iface->if_name))
384 			return 0;
385 		DRV_LOG(DEBUG,
386 			"NetVSC interface \"%s\" (index %u) renamed \"%s\"",
387 			ctx->if_name, ctx->if_index, iface->if_name);
388 		strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
389 		return 0;
390 	}
391 	if (!is_same_ether_addr(eth_addr, &ctx->if_addr))
392 		return 0;
393 	/* Look for associated PCI device. */
394 	ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name,
395 					 "device/subsystem");
396 	if (ret)
397 		return 0;
398 	addr = strrchr(buf, '/');
399 	addr = addr ? addr + 1 : buf;
400 	if (strcmp(addr, "pci"))
401 		return 0;
402 	ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name,
403 					 "device");
404 	if (ret)
405 		return 0;
406 	addr = strrchr(buf, '/');
407 	addr = addr ? addr + 1 : buf;
408 	len = strlen(addr);
409 	if (!len)
410 		return 0;
411 	/* Send PCI device argument to fail-safe PMD instance. */
412 	if (strcmp(addr, ctx->yield))
413 		DRV_LOG(DEBUG, "associating PCI device \"%s\" with NetVSC"
414 			" interface \"%s\" (index %u)", addr, ctx->if_name,
415 			ctx->if_index);
416 	memmove(buf, addr, len + 1);
417 	addr = buf;
418 	buf[len] = '\n';
419 	ret = write(ctx->pipe[1], addr, len + 1);
420 	buf[len] = '\0';
421 	if (ret == -1) {
422 		if (errno == EINTR || errno == EAGAIN)
423 			return 1;
424 		DRV_LOG(WARNING, "cannot associate PCI device name \"%s\" with"
425 			" interface \"%s\": %s", addr, ctx->if_name,
426 			rte_strerror(errno));
427 		return 1;
428 	}
429 	if ((size_t)ret != len + 1) {
430 		/*
431 		 * Attempt to override previous partial write, no need to
432 		 * recover if that fails.
433 		 */
434 		ret = write(ctx->pipe[1], "\n", 1);
435 		(void)ret;
436 		return 1;
437 	}
438 	fsync(ctx->pipe[1]);
439 	memcpy(ctx->yield, addr, len + 1);
440 	return 1;
441 }
442 
443 /**
444  * Alarm callback that regularly probes system network interfaces.
445  *
446  * This callback runs at a frequency determined by VDEV_NETVSC_PROBE_MS as
447  * long as an vdev_netvsc context instance exists.
448  *
449  * @param arg
450  *   Ignored.
451  */
452 static void
453 vdev_netvsc_alarm(__rte_unused void *arg)
454 {
455 	struct vdev_netvsc_ctx *ctx;
456 	int ret;
457 
458 	LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry) {
459 		ret = vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0,
460 		      ctx);
461 		if (ret < 0)
462 			break;
463 	}
464 	if (!vdev_netvsc_ctx_count)
465 		return;
466 	ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
467 				vdev_netvsc_alarm, NULL);
468 	if (ret < 0) {
469 		DRV_LOG(ERR, "unable to reschedule alarm callback: %s",
470 			rte_strerror(-ret));
471 	}
472 }
473 
474 /**
475  * Probe a NetVSC interface to generate a vdev_netvsc context from.
476  *
477  * This function instantiates vdev_netvsc contexts either for all NetVSC
478  * devices found on the system or only a subset provided as device
479  * arguments.
480  *
481  * It is normally used with vdev_netvsc_foreach_iface().
482  *
483  * @param[in] iface
484  *   Pointer to netdevice description structure (name and index).
485  * @param[in] eth_addr
486  *   MAC address associated with @p iface.
487  * @param ap
488  *   Variable arguments list comprising:
489  *
490  *   - const char *name:
491  *     Name associated with current driver instance.
492  *
493  *   - struct rte_kvargs *kvargs:
494  *     Device arguments provided to current driver instance.
495  *
496  *   - int force:
497  *     Accept specified interface even if not detected as NetVSC.
498  *
499  *   - unsigned int specified:
500  *     Number of specific netdevices provided as device arguments.
501  *
502  *   - unsigned int *matched:
503  *     The number of specified netdevices matched by this function.
504  *
505  * @return
506  *   A nonzero value when interface matches, 0 otherwise or in case of
507  *   error.
508  */
509 static int
510 vdev_netvsc_netvsc_probe(const struct if_nameindex *iface,
511 			 const struct ether_addr *eth_addr,
512 			 va_list ap)
513 {
514 	const char *name = va_arg(ap, const char *);
515 	struct rte_kvargs *kvargs = va_arg(ap, struct rte_kvargs *);
516 	unsigned int specified = va_arg(ap, unsigned int);
517 	unsigned int *matched = va_arg(ap, unsigned int *);
518 	unsigned int i;
519 	struct vdev_netvsc_ctx *ctx;
520 	int ret;
521 
522 	/* Probe all interfaces when none are specified. */
523 	if (specified) {
524 		for (i = 0; i != kvargs->count; ++i) {
525 			const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
526 
527 			if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE)) {
528 				if (!strcmp(pair->value, iface->if_name))
529 					break;
530 			} else if (!strcmp(pair->key, VDEV_NETVSC_ARG_MAC)) {
531 				struct ether_addr tmp;
532 
533 				if (sscanf(pair->value,
534 					   "%" SCNx8 ":%" SCNx8 ":%" SCNx8 ":"
535 					   "%" SCNx8 ":%" SCNx8 ":%" SCNx8,
536 					   &tmp.addr_bytes[0],
537 					   &tmp.addr_bytes[1],
538 					   &tmp.addr_bytes[2],
539 					   &tmp.addr_bytes[3],
540 					   &tmp.addr_bytes[4],
541 					   &tmp.addr_bytes[5]) != 6) {
542 					DRV_LOG(ERR,
543 						"invalid MAC address format"
544 						" \"%s\"",
545 						pair->value);
546 					return -EINVAL;
547 				}
548 				if (is_same_ether_addr(eth_addr, &tmp))
549 					break;
550 			}
551 		}
552 		if (i == kvargs->count)
553 			return 0;
554 		++(*matched);
555 	}
556 	/* Weed out interfaces already handled. */
557 	LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry)
558 		if (ctx->if_index == iface->if_index)
559 			break;
560 	if (ctx) {
561 		if (!specified)
562 			return 0;
563 		DRV_LOG(WARNING,
564 			"interface \"%s\" (index %u) is already handled,"
565 			" skipping",
566 			iface->if_name, iface->if_index);
567 		return 0;
568 	}
569 	/* Routed NetVSC should not be probed. */
570 	if (vdev_netvsc_has_route(iface, AF_INET) ||
571 	    vdev_netvsc_has_route(iface, AF_INET6)) {
572 		if (!specified)
573 			return 0;
574 		DRV_LOG(WARNING, "probably using routed NetVSC interface \"%s\""
575 			" (index %u)", iface->if_name, iface->if_index);
576 	}
577 	/* Create interface context. */
578 	ctx = calloc(1, sizeof(*ctx));
579 	if (!ctx) {
580 		ret = -errno;
581 		DRV_LOG(ERR, "cannot allocate context for interface \"%s\": %s",
582 			iface->if_name, rte_strerror(errno));
583 		goto error;
584 	}
585 	ctx->id = vdev_netvsc_ctx_count;
586 	strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
587 	ctx->if_index = iface->if_index;
588 	ctx->if_addr = *eth_addr;
589 	ctx->pipe[0] = -1;
590 	ctx->pipe[1] = -1;
591 	ctx->yield[0] = '\0';
592 	if (pipe(ctx->pipe) == -1) {
593 		ret = -errno;
594 		DRV_LOG(ERR,
595 			"cannot allocate control pipe for interface \"%s\": %s",
596 			ctx->if_name, rte_strerror(errno));
597 		goto error;
598 	}
599 	for (i = 0; i != RTE_DIM(ctx->pipe); ++i) {
600 		int flf = fcntl(ctx->pipe[i], F_GETFL);
601 
602 		if (flf != -1 &&
603 		    fcntl(ctx->pipe[i], F_SETFL, flf | O_NONBLOCK) != -1)
604 			continue;
605 		ret = -errno;
606 		DRV_LOG(ERR, "cannot toggle non-blocking flag on control file"
607 			" descriptor #%u (%d): %s", i, ctx->pipe[i],
608 			rte_strerror(errno));
609 		goto error;
610 	}
611 	/* Generate virtual device name and arguments. */
612 	i = 0;
613 	ret = snprintf(ctx->name, sizeof(ctx->name), "%s_id%u",
614 		       name, ctx->id);
615 	if (ret == -1 || (size_t)ret >= sizeof(ctx->name))
616 		++i;
617 	ret = snprintf(ctx->devname, sizeof(ctx->devname), "net_failsafe_vsc%u",
618 		       ctx->id);
619 	if (ret == -1 || (size_t)ret >= sizeof(ctx->devname))
620 		++i;
621 	ret = snprintf(ctx->devargs, sizeof(ctx->devargs),
622 		       "fd(%d),dev(net_tap_vsc%u,remote=%s)",
623 		       ctx->pipe[0], ctx->id, ctx->if_name);
624 	if (ret == -1 || (size_t)ret >= sizeof(ctx->devargs))
625 		++i;
626 	if (i) {
627 		ret = -ENOBUFS;
628 		DRV_LOG(ERR, "generated virtual device name or argument list"
629 			" too long for interface \"%s\"", ctx->if_name);
630 		goto error;
631 	}
632 	/* Request virtual device generation. */
633 	DRV_LOG(DEBUG, "generating virtual device \"%s\" with arguments \"%s\"",
634 		ctx->devname, ctx->devargs);
635 	vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0, ctx);
636 	ret = rte_eal_hotplug_add("vdev", ctx->devname, ctx->devargs);
637 	if (ret)
638 		goto error;
639 	LIST_INSERT_HEAD(&vdev_netvsc_ctx_list, ctx, entry);
640 	++vdev_netvsc_ctx_count;
641 	DRV_LOG(DEBUG, "added NetVSC interface \"%s\" to context list",
642 		ctx->if_name);
643 	return 0;
644 error:
645 	if (ctx)
646 		vdev_netvsc_ctx_destroy(ctx);
647 	return ret;
648 }
649 
650 /**
651  * Probe NetVSC interfaces.
652  *
653  * This function probes system netdevices according to the specified device
654  * arguments and starts a periodic alarm callback to notify the resulting
655  * fail-safe PMD instances of their sub-devices whereabouts.
656  *
657  * @param dev
658  *   Virtual device context for driver instance.
659  *
660  * @return
661  *    Always 0, even in case of errors.
662  */
663 static int
664 vdev_netvsc_vdev_probe(struct rte_vdev_device *dev)
665 {
666 	static const char *const vdev_netvsc_arg[] = {
667 		VDEV_NETVSC_ARG_IFACE,
668 		VDEV_NETVSC_ARG_MAC,
669 		VDEV_NETVSC_ARG_FORCE,
670 		VDEV_NETVSC_ARG_IGNORE,
671 		NULL,
672 	};
673 	const char *name = rte_vdev_device_name(dev);
674 	const char *args = rte_vdev_device_args(dev);
675 	struct rte_kvargs *kvargs = rte_kvargs_parse(args ? args : "",
676 						     vdev_netvsc_arg);
677 	unsigned int specified = 0;
678 	unsigned int matched = 0;
679 	int force = 0;
680 	int ignore = 0;
681 	unsigned int i;
682 	int ret;
683 
684 	DRV_LOG(DEBUG, "invoked as \"%s\", using arguments \"%s\"", name, args);
685 	if (!kvargs) {
686 		DRV_LOG(ERR, "cannot parse arguments list");
687 		goto error;
688 	}
689 	for (i = 0; i != kvargs->count; ++i) {
690 		const struct rte_kvargs_pair *pair = &kvargs->pairs[i];
691 
692 		if (!strcmp(pair->key, VDEV_NETVSC_ARG_FORCE))
693 			force = !!atoi(pair->value);
694 		else if (!strcmp(pair->key, VDEV_NETVSC_ARG_IGNORE))
695 			ignore = !!atoi(pair->value);
696 		else if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE) ||
697 			 !strcmp(pair->key, VDEV_NETVSC_ARG_MAC))
698 			++specified;
699 	}
700 	if (ignore) {
701 		if (kvargs)
702 			rte_kvargs_free(kvargs);
703 		return 0;
704 	}
705 	if (specified > 1) {
706 		DRV_LOG(ERR, "More than one way used to specify the netvsc"
707 			" device.");
708 		goto error;
709 	}
710 	rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
711 	/* Gather interfaces. */
712 	ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 1, name,
713 					kvargs, specified, &matched);
714 	if (ret < 0)
715 		goto error;
716 	if (specified && matched < specified) {
717 		if (!force) {
718 			DRV_LOG(ERR, "Cannot find the specified netvsc device");
719 			goto error;
720 		}
721 		/* Try to force probing on non-netvsc specified device. */
722 		if (vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 0, name,
723 					      kvargs, specified, &matched) < 0)
724 			goto error;
725 		if (matched < specified) {
726 			DRV_LOG(ERR, "Cannot find the specified device");
727 			goto error;
728 		}
729 		DRV_LOG(WARNING, "non-netvsc device was probed as netvsc");
730 	}
731 	ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
732 				vdev_netvsc_alarm, NULL);
733 	if (ret < 0) {
734 		DRV_LOG(ERR, "unable to schedule alarm callback: %s",
735 			rte_strerror(-ret));
736 		goto error;
737 	}
738 error:
739 	if (kvargs)
740 		rte_kvargs_free(kvargs);
741 	++vdev_netvsc_ctx_inst;
742 	return 0;
743 }
744 
745 /**
746  * Remove driver instance.
747  *
748  * The alarm callback and underlying vdev_netvsc context instances are only
749  * destroyed after the last PMD instance is removed.
750  *
751  * @param dev
752  *   Virtual device context for driver instance.
753  *
754  * @return
755  *   Always 0.
756  */
757 static int
758 vdev_netvsc_vdev_remove(__rte_unused struct rte_vdev_device *dev)
759 {
760 	if (--vdev_netvsc_ctx_inst)
761 		return 0;
762 	rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
763 	while (!LIST_EMPTY(&vdev_netvsc_ctx_list)) {
764 		struct vdev_netvsc_ctx *ctx = LIST_FIRST(&vdev_netvsc_ctx_list);
765 
766 		LIST_REMOVE(ctx, entry);
767 		--vdev_netvsc_ctx_count;
768 		vdev_netvsc_ctx_destroy(ctx);
769 	}
770 	return 0;
771 }
772 
773 /** Virtual device descriptor. */
774 static struct rte_vdev_driver vdev_netvsc_vdev = {
775 	.probe = vdev_netvsc_vdev_probe,
776 	.remove = vdev_netvsc_vdev_remove,
777 };
778 
779 RTE_PMD_REGISTER_VDEV(VDEV_NETVSC_DRIVER, vdev_netvsc_vdev);
780 RTE_PMD_REGISTER_ALIAS(VDEV_NETVSC_DRIVER, eth_vdev_netvsc);
781 RTE_PMD_REGISTER_PARAM_STRING(net_vdev_netvsc,
782 			      VDEV_NETVSC_ARG_IFACE "=<string> "
783 			      VDEV_NETVSC_ARG_MAC "=<string> "
784 			      VDEV_NETVSC_ARG_FORCE "=<int> "
785 			      VDEV_NETVSC_ARG_IGNORE "=<int>");
786 
787 /** Initialize driver log type. */
788 RTE_INIT(vdev_netvsc_init_log)
789 {
790 	vdev_netvsc_logtype = rte_log_register("pmd.vdev_netvsc");
791 	if (vdev_netvsc_logtype >= 0)
792 		rte_log_set_level(vdev_netvsc_logtype, RTE_LOG_NOTICE);
793 }
794 
795 /** Compare function for vdev find device operation. */
796 static int
797 vdev_netvsc_cmp_rte_device(const struct rte_device *dev1,
798 			   __rte_unused const void *_dev2)
799 {
800 	return strcmp(dev1->devargs->name, VDEV_NETVSC_DRIVER_NAME);
801 }
802 
803 /**
804  * A callback called by vdev bus scan function to ensure this driver probing
805  * automatically in Hyper-V VM system unless it already exists in the
806  * devargs list.
807  */
808 static void
809 vdev_netvsc_scan_callback(__rte_unused void *arg)
810 {
811 	struct rte_vdev_device *dev;
812 	struct rte_devargs *devargs;
813 	struct rte_bus *vbus = rte_bus_find_by_name("vdev");
814 
815 	RTE_EAL_DEVARGS_FOREACH("vdev", devargs)
816 		if (!strcmp(devargs->name, VDEV_NETVSC_DRIVER_NAME))
817 			return;
818 	dev = (struct rte_vdev_device *)vbus->find_device(NULL,
819 		vdev_netvsc_cmp_rte_device, VDEV_NETVSC_DRIVER_NAME);
820 	if (dev)
821 		return;
822 	if (rte_devargs_add(RTE_DEVTYPE_VIRTUAL, VDEV_NETVSC_DRIVER_NAME))
823 		DRV_LOG(ERR, "unable to add netvsc devargs.");
824 }
825 
826 /** Initialize the custom scan. */
827 RTE_INIT(vdev_netvsc_custom_scan_add)
828 {
829 	if (rte_hypervisor_get() == RTE_HYPERVISOR_HYPERV)
830 		rte_vdev_add_custom_scan(vdev_netvsc_scan_callback, NULL);
831 }
832