xref: /openbmc/linux/drivers/net/hyperv/netvsc_drv.c (revision ae88357c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2009, Microsoft Corporation.
4  *
5  * Authors:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  *   Hank Janssen  <hjanssen@microsoft.com>
8  */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/init.h>
12 #include <linux/atomic.h>
13 #include <linux/ethtool.h>
14 #include <linux/module.h>
15 #include <linux/highmem.h>
16 #include <linux/device.h>
17 #include <linux/io.h>
18 #include <linux/delay.h>
19 #include <linux/netdevice.h>
20 #include <linux/inetdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/pci.h>
23 #include <linux/skbuff.h>
24 #include <linux/if_vlan.h>
25 #include <linux/in.h>
26 #include <linux/slab.h>
27 #include <linux/rtnetlink.h>
28 #include <linux/netpoll.h>
29 #include <linux/bpf.h>
30 
31 #include <net/arp.h>
32 #include <net/route.h>
33 #include <net/sock.h>
34 #include <net/pkt_sched.h>
35 #include <net/checksum.h>
36 #include <net/ip6_checksum.h>
37 
38 #include "hyperv_net.h"
39 
40 #define RING_SIZE_MIN	64
41 
42 #define LINKCHANGE_INT (2 * HZ)
43 #define VF_TAKEOVER_INT (HZ / 10)
44 
45 static unsigned int ring_size __ro_after_init = 128;
46 module_param(ring_size, uint, 0444);
47 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
48 unsigned int netvsc_ring_bytes __ro_after_init;
49 
50 static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
51 				NETIF_MSG_LINK | NETIF_MSG_IFUP |
52 				NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
53 				NETIF_MSG_TX_ERR;
54 
55 static int debug = -1;
56 module_param(debug, int, 0444);
57 MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
58 
59 static LIST_HEAD(netvsc_dev_list);
60 
61 static void netvsc_change_rx_flags(struct net_device *net, int change)
62 {
63 	struct net_device_context *ndev_ctx = netdev_priv(net);
64 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
65 	int inc;
66 
67 	if (!vf_netdev)
68 		return;
69 
70 	if (change & IFF_PROMISC) {
71 		inc = (net->flags & IFF_PROMISC) ? 1 : -1;
72 		dev_set_promiscuity(vf_netdev, inc);
73 	}
74 
75 	if (change & IFF_ALLMULTI) {
76 		inc = (net->flags & IFF_ALLMULTI) ? 1 : -1;
77 		dev_set_allmulti(vf_netdev, inc);
78 	}
79 }
80 
81 static void netvsc_set_rx_mode(struct net_device *net)
82 {
83 	struct net_device_context *ndev_ctx = netdev_priv(net);
84 	struct net_device *vf_netdev;
85 	struct netvsc_device *nvdev;
86 
87 	rcu_read_lock();
88 	vf_netdev = rcu_dereference(ndev_ctx->vf_netdev);
89 	if (vf_netdev) {
90 		dev_uc_sync(vf_netdev, net);
91 		dev_mc_sync(vf_netdev, net);
92 	}
93 
94 	nvdev = rcu_dereference(ndev_ctx->nvdev);
95 	if (nvdev)
96 		rndis_filter_update(nvdev);
97 	rcu_read_unlock();
98 }
99 
100 static void netvsc_tx_enable(struct netvsc_device *nvscdev,
101 			     struct net_device *ndev)
102 {
103 	nvscdev->tx_disable = false;
104 	virt_wmb(); /* ensure queue wake up mechanism is on */
105 
106 	netif_tx_wake_all_queues(ndev);
107 }
108 
109 static int netvsc_open(struct net_device *net)
110 {
111 	struct net_device_context *ndev_ctx = netdev_priv(net);
112 	struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
113 	struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev);
114 	struct rndis_device *rdev;
115 	int ret = 0;
116 
117 	netif_carrier_off(net);
118 
119 	/* Open up the device */
120 	ret = rndis_filter_open(nvdev);
121 	if (ret != 0) {
122 		netdev_err(net, "unable to open device (ret %d).\n", ret);
123 		return ret;
124 	}
125 
126 	rdev = nvdev->extension;
127 	if (!rdev->link_state) {
128 		netif_carrier_on(net);
129 		netvsc_tx_enable(nvdev, net);
130 	}
131 
132 	if (vf_netdev) {
133 		/* Setting synthetic device up transparently sets
134 		 * slave as up. If open fails, then slave will be
135 		 * still be offline (and not used).
136 		 */
137 		ret = dev_open(vf_netdev, NULL);
138 		if (ret)
139 			netdev_warn(net,
140 				    "unable to open slave: %s: %d\n",
141 				    vf_netdev->name, ret);
142 	}
143 	return 0;
144 }
145 
146 static int netvsc_wait_until_empty(struct netvsc_device *nvdev)
147 {
148 	unsigned int retry = 0;
149 	int i;
150 
151 	/* Ensure pending bytes in ring are read */
152 	for (;;) {
153 		u32 aread = 0;
154 
155 		for (i = 0; i < nvdev->num_chn; i++) {
156 			struct vmbus_channel *chn
157 				= nvdev->chan_table[i].channel;
158 
159 			if (!chn)
160 				continue;
161 
162 			/* make sure receive not running now */
163 			napi_synchronize(&nvdev->chan_table[i].napi);
164 
165 			aread = hv_get_bytes_to_read(&chn->inbound);
166 			if (aread)
167 				break;
168 
169 			aread = hv_get_bytes_to_read(&chn->outbound);
170 			if (aread)
171 				break;
172 		}
173 
174 		if (aread == 0)
175 			return 0;
176 
177 		if (++retry > RETRY_MAX)
178 			return -ETIMEDOUT;
179 
180 		usleep_range(RETRY_US_LO, RETRY_US_HI);
181 	}
182 }
183 
184 static void netvsc_tx_disable(struct netvsc_device *nvscdev,
185 			      struct net_device *ndev)
186 {
187 	if (nvscdev) {
188 		nvscdev->tx_disable = true;
189 		virt_wmb(); /* ensure txq will not wake up after stop */
190 	}
191 
192 	netif_tx_disable(ndev);
193 }
194 
195 static int netvsc_close(struct net_device *net)
196 {
197 	struct net_device_context *net_device_ctx = netdev_priv(net);
198 	struct net_device *vf_netdev
199 		= rtnl_dereference(net_device_ctx->vf_netdev);
200 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
201 	int ret;
202 
203 	netvsc_tx_disable(nvdev, net);
204 
205 	/* No need to close rndis filter if it is removed already */
206 	if (!nvdev)
207 		return 0;
208 
209 	ret = rndis_filter_close(nvdev);
210 	if (ret != 0) {
211 		netdev_err(net, "unable to close device (ret %d).\n", ret);
212 		return ret;
213 	}
214 
215 	ret = netvsc_wait_until_empty(nvdev);
216 	if (ret)
217 		netdev_err(net, "Ring buffer not empty after closing rndis\n");
218 
219 	if (vf_netdev)
220 		dev_close(vf_netdev);
221 
222 	return ret;
223 }
224 
225 static inline void *init_ppi_data(struct rndis_message *msg,
226 				  u32 ppi_size, u32 pkt_type)
227 {
228 	struct rndis_packet *rndis_pkt = &msg->msg.pkt;
229 	struct rndis_per_packet_info *ppi;
230 
231 	rndis_pkt->data_offset += ppi_size;
232 	ppi = (void *)rndis_pkt + rndis_pkt->per_pkt_info_offset
233 		+ rndis_pkt->per_pkt_info_len;
234 
235 	ppi->size = ppi_size;
236 	ppi->type = pkt_type;
237 	ppi->internal = 0;
238 	ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
239 
240 	rndis_pkt->per_pkt_info_len += ppi_size;
241 
242 	return ppi + 1;
243 }
244 
245 /* Azure hosts don't support non-TCP port numbers in hashing for fragmented
246  * packets. We can use ethtool to change UDP hash level when necessary.
247  */
248 static inline u32 netvsc_get_hash(
249 	struct sk_buff *skb,
250 	const struct net_device_context *ndc)
251 {
252 	struct flow_keys flow;
253 	u32 hash, pkt_proto = 0;
254 	static u32 hashrnd __read_mostly;
255 
256 	net_get_random_once(&hashrnd, sizeof(hashrnd));
257 
258 	if (!skb_flow_dissect_flow_keys(skb, &flow, 0))
259 		return 0;
260 
261 	switch (flow.basic.ip_proto) {
262 	case IPPROTO_TCP:
263 		if (flow.basic.n_proto == htons(ETH_P_IP))
264 			pkt_proto = HV_TCP4_L4HASH;
265 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
266 			pkt_proto = HV_TCP6_L4HASH;
267 
268 		break;
269 
270 	case IPPROTO_UDP:
271 		if (flow.basic.n_proto == htons(ETH_P_IP))
272 			pkt_proto = HV_UDP4_L4HASH;
273 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
274 			pkt_proto = HV_UDP6_L4HASH;
275 
276 		break;
277 	}
278 
279 	if (pkt_proto & ndc->l4_hash) {
280 		return skb_get_hash(skb);
281 	} else {
282 		if (flow.basic.n_proto == htons(ETH_P_IP))
283 			hash = jhash2((u32 *)&flow.addrs.v4addrs, 2, hashrnd);
284 		else if (flow.basic.n_proto == htons(ETH_P_IPV6))
285 			hash = jhash2((u32 *)&flow.addrs.v6addrs, 8, hashrnd);
286 		else
287 			return 0;
288 
289 		__skb_set_sw_hash(skb, hash, false);
290 	}
291 
292 	return hash;
293 }
294 
295 static inline int netvsc_get_tx_queue(struct net_device *ndev,
296 				      struct sk_buff *skb, int old_idx)
297 {
298 	const struct net_device_context *ndc = netdev_priv(ndev);
299 	struct sock *sk = skb->sk;
300 	int q_idx;
301 
302 	q_idx = ndc->tx_table[netvsc_get_hash(skb, ndc) &
303 			      (VRSS_SEND_TAB_SIZE - 1)];
304 
305 	/* If queue index changed record the new value */
306 	if (q_idx != old_idx &&
307 	    sk && sk_fullsock(sk) && rcu_access_pointer(sk->sk_dst_cache))
308 		sk_tx_queue_set(sk, q_idx);
309 
310 	return q_idx;
311 }
312 
313 /*
314  * Select queue for transmit.
315  *
316  * If a valid queue has already been assigned, then use that.
317  * Otherwise compute tx queue based on hash and the send table.
318  *
319  * This is basically similar to default (netdev_pick_tx) with the added step
320  * of using the host send_table when no other queue has been assigned.
321  *
322  * TODO support XPS - but get_xps_queue not exported
323  */
324 static u16 netvsc_pick_tx(struct net_device *ndev, struct sk_buff *skb)
325 {
326 	int q_idx = sk_tx_queue_get(skb->sk);
327 
328 	if (q_idx < 0 || skb->ooo_okay || q_idx >= ndev->real_num_tx_queues) {
329 		/* If forwarding a packet, we use the recorded queue when
330 		 * available for better cache locality.
331 		 */
332 		if (skb_rx_queue_recorded(skb))
333 			q_idx = skb_get_rx_queue(skb);
334 		else
335 			q_idx = netvsc_get_tx_queue(ndev, skb, q_idx);
336 	}
337 
338 	return q_idx;
339 }
340 
341 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
342 			       struct net_device *sb_dev)
343 {
344 	struct net_device_context *ndc = netdev_priv(ndev);
345 	struct net_device *vf_netdev;
346 	u16 txq;
347 
348 	rcu_read_lock();
349 	vf_netdev = rcu_dereference(ndc->vf_netdev);
350 	if (vf_netdev) {
351 		const struct net_device_ops *vf_ops = vf_netdev->netdev_ops;
352 
353 		if (vf_ops->ndo_select_queue)
354 			txq = vf_ops->ndo_select_queue(vf_netdev, skb, sb_dev);
355 		else
356 			txq = netdev_pick_tx(vf_netdev, skb, NULL);
357 
358 		/* Record the queue selected by VF so that it can be
359 		 * used for common case where VF has more queues than
360 		 * the synthetic device.
361 		 */
362 		qdisc_skb_cb(skb)->slave_dev_queue_mapping = txq;
363 	} else {
364 		txq = netvsc_pick_tx(ndev, skb);
365 	}
366 	rcu_read_unlock();
367 
368 	while (txq >= ndev->real_num_tx_queues)
369 		txq -= ndev->real_num_tx_queues;
370 
371 	return txq;
372 }
373 
374 static u32 fill_pg_buf(unsigned long hvpfn, u32 offset, u32 len,
375 		       struct hv_page_buffer *pb)
376 {
377 	int j = 0;
378 
379 	hvpfn += offset >> HV_HYP_PAGE_SHIFT;
380 	offset = offset & ~HV_HYP_PAGE_MASK;
381 
382 	while (len > 0) {
383 		unsigned long bytes;
384 
385 		bytes = HV_HYP_PAGE_SIZE - offset;
386 		if (bytes > len)
387 			bytes = len;
388 		pb[j].pfn = hvpfn;
389 		pb[j].offset = offset;
390 		pb[j].len = bytes;
391 
392 		offset += bytes;
393 		len -= bytes;
394 
395 		if (offset == HV_HYP_PAGE_SIZE && len) {
396 			hvpfn++;
397 			offset = 0;
398 			j++;
399 		}
400 	}
401 
402 	return j + 1;
403 }
404 
405 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
406 			   struct hv_netvsc_packet *packet,
407 			   struct hv_page_buffer *pb)
408 {
409 	u32 slots_used = 0;
410 	char *data = skb->data;
411 	int frags = skb_shinfo(skb)->nr_frags;
412 	int i;
413 
414 	/* The packet is laid out thus:
415 	 * 1. hdr: RNDIS header and PPI
416 	 * 2. skb linear data
417 	 * 3. skb fragment data
418 	 */
419 	slots_used += fill_pg_buf(virt_to_hvpfn(hdr),
420 				  offset_in_hvpage(hdr),
421 				  len,
422 				  &pb[slots_used]);
423 
424 	packet->rmsg_size = len;
425 	packet->rmsg_pgcnt = slots_used;
426 
427 	slots_used += fill_pg_buf(virt_to_hvpfn(data),
428 				  offset_in_hvpage(data),
429 				  skb_headlen(skb),
430 				  &pb[slots_used]);
431 
432 	for (i = 0; i < frags; i++) {
433 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
434 
435 		slots_used += fill_pg_buf(page_to_hvpfn(skb_frag_page(frag)),
436 					  skb_frag_off(frag),
437 					  skb_frag_size(frag),
438 					  &pb[slots_used]);
439 	}
440 	return slots_used;
441 }
442 
443 static int count_skb_frag_slots(struct sk_buff *skb)
444 {
445 	int i, frags = skb_shinfo(skb)->nr_frags;
446 	int pages = 0;
447 
448 	for (i = 0; i < frags; i++) {
449 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
450 		unsigned long size = skb_frag_size(frag);
451 		unsigned long offset = skb_frag_off(frag);
452 
453 		/* Skip unused frames from start of page */
454 		offset &= ~HV_HYP_PAGE_MASK;
455 		pages += HVPFN_UP(offset + size);
456 	}
457 	return pages;
458 }
459 
460 static int netvsc_get_slots(struct sk_buff *skb)
461 {
462 	char *data = skb->data;
463 	unsigned int offset = offset_in_hvpage(data);
464 	unsigned int len = skb_headlen(skb);
465 	int slots;
466 	int frag_slots;
467 
468 	slots = DIV_ROUND_UP(offset + len, HV_HYP_PAGE_SIZE);
469 	frag_slots = count_skb_frag_slots(skb);
470 	return slots + frag_slots;
471 }
472 
473 static u32 net_checksum_info(struct sk_buff *skb)
474 {
475 	if (skb->protocol == htons(ETH_P_IP)) {
476 		struct iphdr *ip = ip_hdr(skb);
477 
478 		if (ip->protocol == IPPROTO_TCP)
479 			return TRANSPORT_INFO_IPV4_TCP;
480 		else if (ip->protocol == IPPROTO_UDP)
481 			return TRANSPORT_INFO_IPV4_UDP;
482 	} else {
483 		struct ipv6hdr *ip6 = ipv6_hdr(skb);
484 
485 		if (ip6->nexthdr == IPPROTO_TCP)
486 			return TRANSPORT_INFO_IPV6_TCP;
487 		else if (ip6->nexthdr == IPPROTO_UDP)
488 			return TRANSPORT_INFO_IPV6_UDP;
489 	}
490 
491 	return TRANSPORT_INFO_NOT_IP;
492 }
493 
494 /* Send skb on the slave VF device. */
495 static int netvsc_vf_xmit(struct net_device *net, struct net_device *vf_netdev,
496 			  struct sk_buff *skb)
497 {
498 	struct net_device_context *ndev_ctx = netdev_priv(net);
499 	unsigned int len = skb->len;
500 	int rc;
501 
502 	skb->dev = vf_netdev;
503 	skb_record_rx_queue(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
504 
505 	rc = dev_queue_xmit(skb);
506 	if (likely(rc == NET_XMIT_SUCCESS || rc == NET_XMIT_CN)) {
507 		struct netvsc_vf_pcpu_stats *pcpu_stats
508 			= this_cpu_ptr(ndev_ctx->vf_stats);
509 
510 		u64_stats_update_begin(&pcpu_stats->syncp);
511 		pcpu_stats->tx_packets++;
512 		pcpu_stats->tx_bytes += len;
513 		u64_stats_update_end(&pcpu_stats->syncp);
514 	} else {
515 		this_cpu_inc(ndev_ctx->vf_stats->tx_dropped);
516 	}
517 
518 	return rc;
519 }
520 
521 static int netvsc_xmit(struct sk_buff *skb, struct net_device *net, bool xdp_tx)
522 {
523 	struct net_device_context *net_device_ctx = netdev_priv(net);
524 	struct hv_netvsc_packet *packet = NULL;
525 	int ret;
526 	unsigned int num_data_pgs;
527 	struct rndis_message *rndis_msg;
528 	struct net_device *vf_netdev;
529 	u32 rndis_msg_size;
530 	u32 hash;
531 	struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT];
532 
533 	/* If VF is present and up then redirect packets to it.
534 	 * Skip the VF if it is marked down or has no carrier.
535 	 * If netpoll is in uses, then VF can not be used either.
536 	 */
537 	vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev);
538 	if (vf_netdev && netif_running(vf_netdev) &&
539 	    netif_carrier_ok(vf_netdev) && !netpoll_tx_running(net) &&
540 	    net_device_ctx->data_path_is_vf)
541 		return netvsc_vf_xmit(net, vf_netdev, skb);
542 
543 	/* We will atmost need two pages to describe the rndis
544 	 * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
545 	 * of pages in a single packet. If skb is scattered around
546 	 * more pages we try linearizing it.
547 	 */
548 
549 	num_data_pgs = netvsc_get_slots(skb) + 2;
550 
551 	if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) {
552 		++net_device_ctx->eth_stats.tx_scattered;
553 
554 		if (skb_linearize(skb))
555 			goto no_memory;
556 
557 		num_data_pgs = netvsc_get_slots(skb) + 2;
558 		if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
559 			++net_device_ctx->eth_stats.tx_too_big;
560 			goto drop;
561 		}
562 	}
563 
564 	/*
565 	 * Place the rndis header in the skb head room and
566 	 * the skb->cb will be used for hv_netvsc_packet
567 	 * structure.
568 	 */
569 	ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
570 	if (ret)
571 		goto no_memory;
572 
573 	/* Use the skb control buffer for building up the packet */
574 	BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
575 			sizeof_field(struct sk_buff, cb));
576 	packet = (struct hv_netvsc_packet *)skb->cb;
577 
578 	packet->q_idx = skb_get_queue_mapping(skb);
579 
580 	packet->total_data_buflen = skb->len;
581 	packet->total_bytes = skb->len;
582 	packet->total_packets = 1;
583 
584 	rndis_msg = (struct rndis_message *)skb->head;
585 
586 	/* Add the rndis header */
587 	rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
588 	rndis_msg->msg_len = packet->total_data_buflen;
589 
590 	rndis_msg->msg.pkt = (struct rndis_packet) {
591 		.data_offset = sizeof(struct rndis_packet),
592 		.data_len = packet->total_data_buflen,
593 		.per_pkt_info_offset = sizeof(struct rndis_packet),
594 	};
595 
596 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
597 
598 	hash = skb_get_hash_raw(skb);
599 	if (hash != 0 && net->real_num_tx_queues > 1) {
600 		u32 *hash_info;
601 
602 		rndis_msg_size += NDIS_HASH_PPI_SIZE;
603 		hash_info = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
604 					  NBL_HASH_VALUE);
605 		*hash_info = hash;
606 	}
607 
608 	/* When using AF_PACKET we need to drop VLAN header from
609 	 * the frame and update the SKB to allow the HOST OS
610 	 * to transmit the 802.1Q packet
611 	 */
612 	if (skb->protocol == htons(ETH_P_8021Q)) {
613 		u16 vlan_tci;
614 
615 		skb_reset_mac_header(skb);
616 		if (eth_type_vlan(eth_hdr(skb)->h_proto)) {
617 			if (unlikely(__skb_vlan_pop(skb, &vlan_tci) != 0)) {
618 				++net_device_ctx->eth_stats.vlan_error;
619 				goto drop;
620 			}
621 
622 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tci);
623 			/* Update the NDIS header pkt lengths */
624 			packet->total_data_buflen -= VLAN_HLEN;
625 			packet->total_bytes -= VLAN_HLEN;
626 			rndis_msg->msg_len = packet->total_data_buflen;
627 			rndis_msg->msg.pkt.data_len = packet->total_data_buflen;
628 		}
629 	}
630 
631 	if (skb_vlan_tag_present(skb)) {
632 		struct ndis_pkt_8021q_info *vlan;
633 
634 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
635 		vlan = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
636 				     IEEE_8021Q_INFO);
637 
638 		vlan->value = 0;
639 		vlan->vlanid = skb_vlan_tag_get_id(skb);
640 		vlan->cfi = skb_vlan_tag_get_cfi(skb);
641 		vlan->pri = skb_vlan_tag_get_prio(skb);
642 	}
643 
644 	if (skb_is_gso(skb)) {
645 		struct ndis_tcp_lso_info *lso_info;
646 
647 		rndis_msg_size += NDIS_LSO_PPI_SIZE;
648 		lso_info = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
649 					 TCP_LARGESEND_PKTINFO);
650 
651 		lso_info->value = 0;
652 		lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
653 		if (skb->protocol == htons(ETH_P_IP)) {
654 			lso_info->lso_v2_transmit.ip_version =
655 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
656 			ip_hdr(skb)->tot_len = 0;
657 			ip_hdr(skb)->check = 0;
658 			tcp_hdr(skb)->check =
659 				~csum_tcpudp_magic(ip_hdr(skb)->saddr,
660 						   ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
661 		} else {
662 			lso_info->lso_v2_transmit.ip_version =
663 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
664 			tcp_v6_gso_csum_prep(skb);
665 		}
666 		lso_info->lso_v2_transmit.tcp_header_offset = skb_transport_offset(skb);
667 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
668 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
669 		if (net_checksum_info(skb) & net_device_ctx->tx_checksum_mask) {
670 			struct ndis_tcp_ip_checksum_info *csum_info;
671 
672 			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
673 			csum_info = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
674 						  TCPIP_CHKSUM_PKTINFO);
675 
676 			csum_info->value = 0;
677 			csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
678 
679 			if (skb->protocol == htons(ETH_P_IP)) {
680 				csum_info->transmit.is_ipv4 = 1;
681 
682 				if (ip_hdr(skb)->protocol == IPPROTO_TCP)
683 					csum_info->transmit.tcp_checksum = 1;
684 				else
685 					csum_info->transmit.udp_checksum = 1;
686 			} else {
687 				csum_info->transmit.is_ipv6 = 1;
688 
689 				if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
690 					csum_info->transmit.tcp_checksum = 1;
691 				else
692 					csum_info->transmit.udp_checksum = 1;
693 			}
694 		} else {
695 			/* Can't do offload of this type of checksum */
696 			if (skb_checksum_help(skb))
697 				goto drop;
698 		}
699 	}
700 
701 	/* Start filling in the page buffers with the rndis hdr */
702 	rndis_msg->msg_len += rndis_msg_size;
703 	packet->total_data_buflen = rndis_msg->msg_len;
704 	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
705 					       skb, packet, pb);
706 
707 	/* timestamp packet in software */
708 	skb_tx_timestamp(skb);
709 
710 	ret = netvsc_send(net, packet, rndis_msg, pb, skb, xdp_tx);
711 	if (likely(ret == 0))
712 		return NETDEV_TX_OK;
713 
714 	if (ret == -EAGAIN) {
715 		++net_device_ctx->eth_stats.tx_busy;
716 		return NETDEV_TX_BUSY;
717 	}
718 
719 	if (ret == -ENOSPC)
720 		++net_device_ctx->eth_stats.tx_no_space;
721 
722 drop:
723 	dev_kfree_skb_any(skb);
724 	net->stats.tx_dropped++;
725 
726 	return NETDEV_TX_OK;
727 
728 no_memory:
729 	++net_device_ctx->eth_stats.tx_no_memory;
730 	goto drop;
731 }
732 
733 static netdev_tx_t netvsc_start_xmit(struct sk_buff *skb,
734 				     struct net_device *ndev)
735 {
736 	return netvsc_xmit(skb, ndev, false);
737 }
738 
739 /*
740  * netvsc_linkstatus_callback - Link up/down notification
741  */
742 void netvsc_linkstatus_callback(struct net_device *net,
743 				struct rndis_message *resp,
744 				void *data, u32 data_buflen)
745 {
746 	struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
747 	struct net_device_context *ndev_ctx = netdev_priv(net);
748 	struct netvsc_reconfig *event;
749 	unsigned long flags;
750 
751 	/* Ensure the packet is big enough to access its fields */
752 	if (resp->msg_len - RNDIS_HEADER_SIZE < sizeof(struct rndis_indicate_status)) {
753 		netdev_err(net, "invalid rndis_indicate_status packet, len: %u\n",
754 			   resp->msg_len);
755 		return;
756 	}
757 
758 	/* Copy the RNDIS indicate status into nvchan->recv_buf */
759 	memcpy(indicate, data + RNDIS_HEADER_SIZE, sizeof(*indicate));
760 
761 	/* Update the physical link speed when changing to another vSwitch */
762 	if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
763 		u32 speed;
764 
765 		/* Validate status_buf_offset and status_buflen.
766 		 *
767 		 * Certain (pre-Fe) implementations of Hyper-V's vSwitch didn't account
768 		 * for the status buffer field in resp->msg_len; perform the validation
769 		 * using data_buflen (>= resp->msg_len).
770 		 */
771 		if (indicate->status_buflen < sizeof(speed) ||
772 		    indicate->status_buf_offset < sizeof(*indicate) ||
773 		    data_buflen - RNDIS_HEADER_SIZE < indicate->status_buf_offset ||
774 		    data_buflen - RNDIS_HEADER_SIZE - indicate->status_buf_offset
775 				< indicate->status_buflen) {
776 			netdev_err(net, "invalid rndis_indicate_status packet\n");
777 			return;
778 		}
779 
780 		speed = *(u32 *)(data + RNDIS_HEADER_SIZE + indicate->status_buf_offset) / 10000;
781 		ndev_ctx->speed = speed;
782 		return;
783 	}
784 
785 	/* Handle these link change statuses below */
786 	if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
787 	    indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
788 	    indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
789 		return;
790 
791 	if (net->reg_state != NETREG_REGISTERED)
792 		return;
793 
794 	event = kzalloc(sizeof(*event), GFP_ATOMIC);
795 	if (!event)
796 		return;
797 	event->event = indicate->status;
798 
799 	spin_lock_irqsave(&ndev_ctx->lock, flags);
800 	list_add_tail(&event->list, &ndev_ctx->reconfig_events);
801 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
802 
803 	schedule_delayed_work(&ndev_ctx->dwork, 0);
804 }
805 
806 static void netvsc_xdp_xmit(struct sk_buff *skb, struct net_device *ndev)
807 {
808 	int rc;
809 
810 	skb->queue_mapping = skb_get_rx_queue(skb);
811 	__skb_push(skb, ETH_HLEN);
812 
813 	rc = netvsc_xmit(skb, ndev, true);
814 
815 	if (dev_xmit_complete(rc))
816 		return;
817 
818 	dev_kfree_skb_any(skb);
819 	ndev->stats.tx_dropped++;
820 }
821 
822 static void netvsc_comp_ipcsum(struct sk_buff *skb)
823 {
824 	struct iphdr *iph = (struct iphdr *)skb->data;
825 
826 	iph->check = 0;
827 	iph->check = ip_fast_csum(iph, iph->ihl);
828 }
829 
830 static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net,
831 					     struct netvsc_channel *nvchan,
832 					     struct xdp_buff *xdp)
833 {
834 	struct napi_struct *napi = &nvchan->napi;
835 	const struct ndis_pkt_8021q_info *vlan = &nvchan->rsc.vlan;
836 	const struct ndis_tcp_ip_checksum_info *csum_info =
837 						&nvchan->rsc.csum_info;
838 	const u32 *hash_info = &nvchan->rsc.hash_info;
839 	u8 ppi_flags = nvchan->rsc.ppi_flags;
840 	struct sk_buff *skb;
841 	void *xbuf = xdp->data_hard_start;
842 	int i;
843 
844 	if (xbuf) {
845 		unsigned int hdroom = xdp->data - xdp->data_hard_start;
846 		unsigned int xlen = xdp->data_end - xdp->data;
847 		unsigned int frag_size = xdp->frame_sz;
848 
849 		skb = build_skb(xbuf, frag_size);
850 
851 		if (!skb) {
852 			__free_page(virt_to_page(xbuf));
853 			return NULL;
854 		}
855 
856 		skb_reserve(skb, hdroom);
857 		skb_put(skb, xlen);
858 		skb->dev = napi->dev;
859 	} else {
860 		skb = napi_alloc_skb(napi, nvchan->rsc.pktlen);
861 
862 		if (!skb)
863 			return NULL;
864 
865 		/* Copy to skb. This copy is needed here since the memory
866 		 * pointed by hv_netvsc_packet cannot be deallocated.
867 		 */
868 		for (i = 0; i < nvchan->rsc.cnt; i++)
869 			skb_put_data(skb, nvchan->rsc.data[i],
870 				     nvchan->rsc.len[i]);
871 	}
872 
873 	skb->protocol = eth_type_trans(skb, net);
874 
875 	/* skb is already created with CHECKSUM_NONE */
876 	skb_checksum_none_assert(skb);
877 
878 	/* Incoming packets may have IP header checksum verified by the host.
879 	 * They may not have IP header checksum computed after coalescing.
880 	 * We compute it here if the flags are set, because on Linux, the IP
881 	 * checksum is always checked.
882 	 */
883 	if ((ppi_flags & NVSC_RSC_CSUM_INFO) && csum_info->receive.ip_checksum_value_invalid &&
884 	    csum_info->receive.ip_checksum_succeeded &&
885 	    skb->protocol == htons(ETH_P_IP)) {
886 		/* Check that there is enough space to hold the IP header. */
887 		if (skb_headlen(skb) < sizeof(struct iphdr)) {
888 			kfree_skb(skb);
889 			return NULL;
890 		}
891 		netvsc_comp_ipcsum(skb);
892 	}
893 
894 	/* Do L4 checksum offload if enabled and present. */
895 	if ((ppi_flags & NVSC_RSC_CSUM_INFO) && (net->features & NETIF_F_RXCSUM)) {
896 		if (csum_info->receive.tcp_checksum_succeeded ||
897 		    csum_info->receive.udp_checksum_succeeded)
898 			skb->ip_summed = CHECKSUM_UNNECESSARY;
899 	}
900 
901 	if ((ppi_flags & NVSC_RSC_HASH_INFO) && (net->features & NETIF_F_RXHASH))
902 		skb_set_hash(skb, *hash_info, PKT_HASH_TYPE_L4);
903 
904 	if (ppi_flags & NVSC_RSC_VLAN) {
905 		u16 vlan_tci = vlan->vlanid | (vlan->pri << VLAN_PRIO_SHIFT) |
906 			(vlan->cfi ? VLAN_CFI_MASK : 0);
907 
908 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
909 				       vlan_tci);
910 	}
911 
912 	return skb;
913 }
914 
915 /*
916  * netvsc_recv_callback -  Callback when we receive a packet from the
917  * "wire" on the specified device.
918  */
919 int netvsc_recv_callback(struct net_device *net,
920 			 struct netvsc_device *net_device,
921 			 struct netvsc_channel *nvchan)
922 {
923 	struct net_device_context *net_device_ctx = netdev_priv(net);
924 	struct vmbus_channel *channel = nvchan->channel;
925 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
926 	struct sk_buff *skb;
927 	struct netvsc_stats *rx_stats = &nvchan->rx_stats;
928 	struct xdp_buff xdp;
929 	u32 act;
930 
931 	if (net->reg_state != NETREG_REGISTERED)
932 		return NVSP_STAT_FAIL;
933 
934 	act = netvsc_run_xdp(net, nvchan, &xdp);
935 
936 	if (act != XDP_PASS && act != XDP_TX) {
937 		u64_stats_update_begin(&rx_stats->syncp);
938 		rx_stats->xdp_drop++;
939 		u64_stats_update_end(&rx_stats->syncp);
940 
941 		return NVSP_STAT_SUCCESS; /* consumed by XDP */
942 	}
943 
944 	/* Allocate a skb - TODO direct I/O to pages? */
945 	skb = netvsc_alloc_recv_skb(net, nvchan, &xdp);
946 
947 	if (unlikely(!skb)) {
948 		++net_device_ctx->eth_stats.rx_no_memory;
949 		return NVSP_STAT_FAIL;
950 	}
951 
952 	skb_record_rx_queue(skb, q_idx);
953 
954 	/*
955 	 * Even if injecting the packet, record the statistics
956 	 * on the synthetic device because modifying the VF device
957 	 * statistics will not work correctly.
958 	 */
959 	u64_stats_update_begin(&rx_stats->syncp);
960 	rx_stats->packets++;
961 	rx_stats->bytes += nvchan->rsc.pktlen;
962 
963 	if (skb->pkt_type == PACKET_BROADCAST)
964 		++rx_stats->broadcast;
965 	else if (skb->pkt_type == PACKET_MULTICAST)
966 		++rx_stats->multicast;
967 	u64_stats_update_end(&rx_stats->syncp);
968 
969 	if (act == XDP_TX) {
970 		netvsc_xdp_xmit(skb, net);
971 		return NVSP_STAT_SUCCESS;
972 	}
973 
974 	napi_gro_receive(&nvchan->napi, skb);
975 	return NVSP_STAT_SUCCESS;
976 }
977 
978 static void netvsc_get_drvinfo(struct net_device *net,
979 			       struct ethtool_drvinfo *info)
980 {
981 	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
982 	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
983 }
984 
985 static void netvsc_get_channels(struct net_device *net,
986 				struct ethtool_channels *channel)
987 {
988 	struct net_device_context *net_device_ctx = netdev_priv(net);
989 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
990 
991 	if (nvdev) {
992 		channel->max_combined	= nvdev->max_chn;
993 		channel->combined_count = nvdev->num_chn;
994 	}
995 }
996 
997 /* Alloc struct netvsc_device_info, and initialize it from either existing
998  * struct netvsc_device, or from default values.
999  */
1000 static
1001 struct netvsc_device_info *netvsc_devinfo_get(struct netvsc_device *nvdev)
1002 {
1003 	struct netvsc_device_info *dev_info;
1004 	struct bpf_prog *prog;
1005 
1006 	dev_info = kzalloc(sizeof(*dev_info), GFP_ATOMIC);
1007 
1008 	if (!dev_info)
1009 		return NULL;
1010 
1011 	if (nvdev) {
1012 		ASSERT_RTNL();
1013 
1014 		dev_info->num_chn = nvdev->num_chn;
1015 		dev_info->send_sections = nvdev->send_section_cnt;
1016 		dev_info->send_section_size = nvdev->send_section_size;
1017 		dev_info->recv_sections = nvdev->recv_section_cnt;
1018 		dev_info->recv_section_size = nvdev->recv_section_size;
1019 
1020 		memcpy(dev_info->rss_key, nvdev->extension->rss_key,
1021 		       NETVSC_HASH_KEYLEN);
1022 
1023 		prog = netvsc_xdp_get(nvdev);
1024 		if (prog) {
1025 			bpf_prog_inc(prog);
1026 			dev_info->bprog = prog;
1027 		}
1028 	} else {
1029 		dev_info->num_chn = VRSS_CHANNEL_DEFAULT;
1030 		dev_info->send_sections = NETVSC_DEFAULT_TX;
1031 		dev_info->send_section_size = NETVSC_SEND_SECTION_SIZE;
1032 		dev_info->recv_sections = NETVSC_DEFAULT_RX;
1033 		dev_info->recv_section_size = NETVSC_RECV_SECTION_SIZE;
1034 	}
1035 
1036 	return dev_info;
1037 }
1038 
1039 /* Free struct netvsc_device_info */
1040 static void netvsc_devinfo_put(struct netvsc_device_info *dev_info)
1041 {
1042 	if (dev_info->bprog) {
1043 		ASSERT_RTNL();
1044 		bpf_prog_put(dev_info->bprog);
1045 	}
1046 
1047 	kfree(dev_info);
1048 }
1049 
1050 static int netvsc_detach(struct net_device *ndev,
1051 			 struct netvsc_device *nvdev)
1052 {
1053 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1054 	struct hv_device *hdev = ndev_ctx->device_ctx;
1055 	int ret;
1056 
1057 	/* Don't try continuing to try and setup sub channels */
1058 	if (cancel_work_sync(&nvdev->subchan_work))
1059 		nvdev->num_chn = 1;
1060 
1061 	netvsc_xdp_set(ndev, NULL, NULL, nvdev);
1062 
1063 	/* If device was up (receiving) then shutdown */
1064 	if (netif_running(ndev)) {
1065 		netvsc_tx_disable(nvdev, ndev);
1066 
1067 		ret = rndis_filter_close(nvdev);
1068 		if (ret) {
1069 			netdev_err(ndev,
1070 				   "unable to close device (ret %d).\n", ret);
1071 			return ret;
1072 		}
1073 
1074 		ret = netvsc_wait_until_empty(nvdev);
1075 		if (ret) {
1076 			netdev_err(ndev,
1077 				   "Ring buffer not empty after closing rndis\n");
1078 			return ret;
1079 		}
1080 	}
1081 
1082 	netif_device_detach(ndev);
1083 
1084 	rndis_filter_device_remove(hdev, nvdev);
1085 
1086 	return 0;
1087 }
1088 
1089 static int netvsc_attach(struct net_device *ndev,
1090 			 struct netvsc_device_info *dev_info)
1091 {
1092 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1093 	struct hv_device *hdev = ndev_ctx->device_ctx;
1094 	struct netvsc_device *nvdev;
1095 	struct rndis_device *rdev;
1096 	struct bpf_prog *prog;
1097 	int ret = 0;
1098 
1099 	nvdev = rndis_filter_device_add(hdev, dev_info);
1100 	if (IS_ERR(nvdev))
1101 		return PTR_ERR(nvdev);
1102 
1103 	if (nvdev->num_chn > 1) {
1104 		ret = rndis_set_subchannel(ndev, nvdev, dev_info);
1105 
1106 		/* if unavailable, just proceed with one queue */
1107 		if (ret) {
1108 			nvdev->max_chn = 1;
1109 			nvdev->num_chn = 1;
1110 		}
1111 	}
1112 
1113 	prog = dev_info->bprog;
1114 	if (prog) {
1115 		bpf_prog_inc(prog);
1116 		ret = netvsc_xdp_set(ndev, prog, NULL, nvdev);
1117 		if (ret) {
1118 			bpf_prog_put(prog);
1119 			goto err1;
1120 		}
1121 	}
1122 
1123 	/* In any case device is now ready */
1124 	nvdev->tx_disable = false;
1125 	netif_device_attach(ndev);
1126 
1127 	/* Note: enable and attach happen when sub-channels setup */
1128 	netif_carrier_off(ndev);
1129 
1130 	if (netif_running(ndev)) {
1131 		ret = rndis_filter_open(nvdev);
1132 		if (ret)
1133 			goto err2;
1134 
1135 		rdev = nvdev->extension;
1136 		if (!rdev->link_state)
1137 			netif_carrier_on(ndev);
1138 	}
1139 
1140 	return 0;
1141 
1142 err2:
1143 	netif_device_detach(ndev);
1144 
1145 err1:
1146 	rndis_filter_device_remove(hdev, nvdev);
1147 
1148 	return ret;
1149 }
1150 
1151 static int netvsc_set_channels(struct net_device *net,
1152 			       struct ethtool_channels *channels)
1153 {
1154 	struct net_device_context *net_device_ctx = netdev_priv(net);
1155 	struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
1156 	unsigned int orig, count = channels->combined_count;
1157 	struct netvsc_device_info *device_info;
1158 	int ret;
1159 
1160 	/* We do not support separate count for rx, tx, or other */
1161 	if (count == 0 ||
1162 	    channels->rx_count || channels->tx_count || channels->other_count)
1163 		return -EINVAL;
1164 
1165 	if (!nvdev || nvdev->destroy)
1166 		return -ENODEV;
1167 
1168 	if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5)
1169 		return -EINVAL;
1170 
1171 	if (count > nvdev->max_chn)
1172 		return -EINVAL;
1173 
1174 	orig = nvdev->num_chn;
1175 
1176 	device_info = netvsc_devinfo_get(nvdev);
1177 
1178 	if (!device_info)
1179 		return -ENOMEM;
1180 
1181 	device_info->num_chn = count;
1182 
1183 	ret = netvsc_detach(net, nvdev);
1184 	if (ret)
1185 		goto out;
1186 
1187 	ret = netvsc_attach(net, device_info);
1188 	if (ret) {
1189 		device_info->num_chn = orig;
1190 		if (netvsc_attach(net, device_info))
1191 			netdev_err(net, "restoring channel setting failed\n");
1192 	}
1193 
1194 out:
1195 	netvsc_devinfo_put(device_info);
1196 	return ret;
1197 }
1198 
1199 static void netvsc_init_settings(struct net_device *dev)
1200 {
1201 	struct net_device_context *ndc = netdev_priv(dev);
1202 
1203 	ndc->l4_hash = HV_DEFAULT_L4HASH;
1204 
1205 	ndc->speed = SPEED_UNKNOWN;
1206 	ndc->duplex = DUPLEX_FULL;
1207 
1208 	dev->features = NETIF_F_LRO;
1209 }
1210 
1211 static int netvsc_get_link_ksettings(struct net_device *dev,
1212 				     struct ethtool_link_ksettings *cmd)
1213 {
1214 	struct net_device_context *ndc = netdev_priv(dev);
1215 	struct net_device *vf_netdev;
1216 
1217 	vf_netdev = rtnl_dereference(ndc->vf_netdev);
1218 
1219 	if (vf_netdev)
1220 		return __ethtool_get_link_ksettings(vf_netdev, cmd);
1221 
1222 	cmd->base.speed = ndc->speed;
1223 	cmd->base.duplex = ndc->duplex;
1224 	cmd->base.port = PORT_OTHER;
1225 
1226 	return 0;
1227 }
1228 
1229 static int netvsc_set_link_ksettings(struct net_device *dev,
1230 				     const struct ethtool_link_ksettings *cmd)
1231 {
1232 	struct net_device_context *ndc = netdev_priv(dev);
1233 	struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
1234 
1235 	if (vf_netdev) {
1236 		if (!vf_netdev->ethtool_ops->set_link_ksettings)
1237 			return -EOPNOTSUPP;
1238 
1239 		return vf_netdev->ethtool_ops->set_link_ksettings(vf_netdev,
1240 								  cmd);
1241 	}
1242 
1243 	return ethtool_virtdev_set_link_ksettings(dev, cmd,
1244 						  &ndc->speed, &ndc->duplex);
1245 }
1246 
1247 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
1248 {
1249 	struct net_device_context *ndevctx = netdev_priv(ndev);
1250 	struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
1251 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1252 	int orig_mtu = ndev->mtu;
1253 	struct netvsc_device_info *device_info;
1254 	int ret = 0;
1255 
1256 	if (!nvdev || nvdev->destroy)
1257 		return -ENODEV;
1258 
1259 	device_info = netvsc_devinfo_get(nvdev);
1260 
1261 	if (!device_info)
1262 		return -ENOMEM;
1263 
1264 	/* Change MTU of underlying VF netdev first. */
1265 	if (vf_netdev) {
1266 		ret = dev_set_mtu(vf_netdev, mtu);
1267 		if (ret)
1268 			goto out;
1269 	}
1270 
1271 	ret = netvsc_detach(ndev, nvdev);
1272 	if (ret)
1273 		goto rollback_vf;
1274 
1275 	ndev->mtu = mtu;
1276 
1277 	ret = netvsc_attach(ndev, device_info);
1278 	if (!ret)
1279 		goto out;
1280 
1281 	/* Attempt rollback to original MTU */
1282 	ndev->mtu = orig_mtu;
1283 
1284 	if (netvsc_attach(ndev, device_info))
1285 		netdev_err(ndev, "restoring mtu failed\n");
1286 rollback_vf:
1287 	if (vf_netdev)
1288 		dev_set_mtu(vf_netdev, orig_mtu);
1289 
1290 out:
1291 	netvsc_devinfo_put(device_info);
1292 	return ret;
1293 }
1294 
1295 static void netvsc_get_vf_stats(struct net_device *net,
1296 				struct netvsc_vf_pcpu_stats *tot)
1297 {
1298 	struct net_device_context *ndev_ctx = netdev_priv(net);
1299 	int i;
1300 
1301 	memset(tot, 0, sizeof(*tot));
1302 
1303 	for_each_possible_cpu(i) {
1304 		const struct netvsc_vf_pcpu_stats *stats
1305 			= per_cpu_ptr(ndev_ctx->vf_stats, i);
1306 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1307 		unsigned int start;
1308 
1309 		do {
1310 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1311 			rx_packets = stats->rx_packets;
1312 			tx_packets = stats->tx_packets;
1313 			rx_bytes = stats->rx_bytes;
1314 			tx_bytes = stats->tx_bytes;
1315 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1316 
1317 		tot->rx_packets += rx_packets;
1318 		tot->tx_packets += tx_packets;
1319 		tot->rx_bytes   += rx_bytes;
1320 		tot->tx_bytes   += tx_bytes;
1321 		tot->tx_dropped += stats->tx_dropped;
1322 	}
1323 }
1324 
1325 static void netvsc_get_pcpu_stats(struct net_device *net,
1326 				  struct netvsc_ethtool_pcpu_stats *pcpu_tot)
1327 {
1328 	struct net_device_context *ndev_ctx = netdev_priv(net);
1329 	struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
1330 	int i;
1331 
1332 	/* fetch percpu stats of vf */
1333 	for_each_possible_cpu(i) {
1334 		const struct netvsc_vf_pcpu_stats *stats =
1335 			per_cpu_ptr(ndev_ctx->vf_stats, i);
1336 		struct netvsc_ethtool_pcpu_stats *this_tot = &pcpu_tot[i];
1337 		unsigned int start;
1338 
1339 		do {
1340 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1341 			this_tot->vf_rx_packets = stats->rx_packets;
1342 			this_tot->vf_tx_packets = stats->tx_packets;
1343 			this_tot->vf_rx_bytes = stats->rx_bytes;
1344 			this_tot->vf_tx_bytes = stats->tx_bytes;
1345 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1346 		this_tot->rx_packets = this_tot->vf_rx_packets;
1347 		this_tot->tx_packets = this_tot->vf_tx_packets;
1348 		this_tot->rx_bytes   = this_tot->vf_rx_bytes;
1349 		this_tot->tx_bytes   = this_tot->vf_tx_bytes;
1350 	}
1351 
1352 	/* fetch percpu stats of netvsc */
1353 	for (i = 0; i < nvdev->num_chn; i++) {
1354 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
1355 		const struct netvsc_stats *stats;
1356 		struct netvsc_ethtool_pcpu_stats *this_tot =
1357 			&pcpu_tot[nvchan->channel->target_cpu];
1358 		u64 packets, bytes;
1359 		unsigned int start;
1360 
1361 		stats = &nvchan->tx_stats;
1362 		do {
1363 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1364 			packets = stats->packets;
1365 			bytes = stats->bytes;
1366 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1367 
1368 		this_tot->tx_bytes	+= bytes;
1369 		this_tot->tx_packets	+= packets;
1370 
1371 		stats = &nvchan->rx_stats;
1372 		do {
1373 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1374 			packets = stats->packets;
1375 			bytes = stats->bytes;
1376 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1377 
1378 		this_tot->rx_bytes	+= bytes;
1379 		this_tot->rx_packets	+= packets;
1380 	}
1381 }
1382 
1383 static void netvsc_get_stats64(struct net_device *net,
1384 			       struct rtnl_link_stats64 *t)
1385 {
1386 	struct net_device_context *ndev_ctx = netdev_priv(net);
1387 	struct netvsc_device *nvdev;
1388 	struct netvsc_vf_pcpu_stats vf_tot;
1389 	int i;
1390 
1391 	rcu_read_lock();
1392 
1393 	nvdev = rcu_dereference(ndev_ctx->nvdev);
1394 	if (!nvdev)
1395 		goto out;
1396 
1397 	netdev_stats_to_stats64(t, &net->stats);
1398 
1399 	netvsc_get_vf_stats(net, &vf_tot);
1400 	t->rx_packets += vf_tot.rx_packets;
1401 	t->tx_packets += vf_tot.tx_packets;
1402 	t->rx_bytes   += vf_tot.rx_bytes;
1403 	t->tx_bytes   += vf_tot.tx_bytes;
1404 	t->tx_dropped += vf_tot.tx_dropped;
1405 
1406 	for (i = 0; i < nvdev->num_chn; i++) {
1407 		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
1408 		const struct netvsc_stats *stats;
1409 		u64 packets, bytes, multicast;
1410 		unsigned int start;
1411 
1412 		stats = &nvchan->tx_stats;
1413 		do {
1414 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1415 			packets = stats->packets;
1416 			bytes = stats->bytes;
1417 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1418 
1419 		t->tx_bytes	+= bytes;
1420 		t->tx_packets	+= packets;
1421 
1422 		stats = &nvchan->rx_stats;
1423 		do {
1424 			start = u64_stats_fetch_begin_irq(&stats->syncp);
1425 			packets = stats->packets;
1426 			bytes = stats->bytes;
1427 			multicast = stats->multicast + stats->broadcast;
1428 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1429 
1430 		t->rx_bytes	+= bytes;
1431 		t->rx_packets	+= packets;
1432 		t->multicast	+= multicast;
1433 	}
1434 out:
1435 	rcu_read_unlock();
1436 }
1437 
1438 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
1439 {
1440 	struct net_device_context *ndc = netdev_priv(ndev);
1441 	struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
1442 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1443 	struct sockaddr *addr = p;
1444 	int err;
1445 
1446 	err = eth_prepare_mac_addr_change(ndev, p);
1447 	if (err)
1448 		return err;
1449 
1450 	if (!nvdev)
1451 		return -ENODEV;
1452 
1453 	if (vf_netdev) {
1454 		err = dev_set_mac_address(vf_netdev, addr, NULL);
1455 		if (err)
1456 			return err;
1457 	}
1458 
1459 	err = rndis_filter_set_device_mac(nvdev, addr->sa_data);
1460 	if (!err) {
1461 		eth_commit_mac_addr_change(ndev, p);
1462 	} else if (vf_netdev) {
1463 		/* rollback change on VF */
1464 		memcpy(addr->sa_data, ndev->dev_addr, ETH_ALEN);
1465 		dev_set_mac_address(vf_netdev, addr, NULL);
1466 	}
1467 
1468 	return err;
1469 }
1470 
1471 static const struct {
1472 	char name[ETH_GSTRING_LEN];
1473 	u16 offset;
1474 } netvsc_stats[] = {
1475 	{ "tx_scattered", offsetof(struct netvsc_ethtool_stats, tx_scattered) },
1476 	{ "tx_no_memory", offsetof(struct netvsc_ethtool_stats, tx_no_memory) },
1477 	{ "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
1478 	{ "tx_too_big",	  offsetof(struct netvsc_ethtool_stats, tx_too_big) },
1479 	{ "tx_busy",	  offsetof(struct netvsc_ethtool_stats, tx_busy) },
1480 	{ "tx_send_full", offsetof(struct netvsc_ethtool_stats, tx_send_full) },
1481 	{ "rx_comp_busy", offsetof(struct netvsc_ethtool_stats, rx_comp_busy) },
1482 	{ "rx_no_memory", offsetof(struct netvsc_ethtool_stats, rx_no_memory) },
1483 	{ "stop_queue", offsetof(struct netvsc_ethtool_stats, stop_queue) },
1484 	{ "wake_queue", offsetof(struct netvsc_ethtool_stats, wake_queue) },
1485 	{ "vlan_error", offsetof(struct netvsc_ethtool_stats, vlan_error) },
1486 }, pcpu_stats[] = {
1487 	{ "cpu%u_rx_packets",
1488 		offsetof(struct netvsc_ethtool_pcpu_stats, rx_packets) },
1489 	{ "cpu%u_rx_bytes",
1490 		offsetof(struct netvsc_ethtool_pcpu_stats, rx_bytes) },
1491 	{ "cpu%u_tx_packets",
1492 		offsetof(struct netvsc_ethtool_pcpu_stats, tx_packets) },
1493 	{ "cpu%u_tx_bytes",
1494 		offsetof(struct netvsc_ethtool_pcpu_stats, tx_bytes) },
1495 	{ "cpu%u_vf_rx_packets",
1496 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_packets) },
1497 	{ "cpu%u_vf_rx_bytes",
1498 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_bytes) },
1499 	{ "cpu%u_vf_tx_packets",
1500 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_packets) },
1501 	{ "cpu%u_vf_tx_bytes",
1502 		offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_bytes) },
1503 }, vf_stats[] = {
1504 	{ "vf_rx_packets", offsetof(struct netvsc_vf_pcpu_stats, rx_packets) },
1505 	{ "vf_rx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, rx_bytes) },
1506 	{ "vf_tx_packets", offsetof(struct netvsc_vf_pcpu_stats, tx_packets) },
1507 	{ "vf_tx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, tx_bytes) },
1508 	{ "vf_tx_dropped", offsetof(struct netvsc_vf_pcpu_stats, tx_dropped) },
1509 };
1510 
1511 #define NETVSC_GLOBAL_STATS_LEN	ARRAY_SIZE(netvsc_stats)
1512 #define NETVSC_VF_STATS_LEN	ARRAY_SIZE(vf_stats)
1513 
1514 /* statistics per queue (rx/tx packets/bytes) */
1515 #define NETVSC_PCPU_STATS_LEN (num_present_cpus() * ARRAY_SIZE(pcpu_stats))
1516 
1517 /* 5 statistics per queue (rx/tx packets/bytes, rx xdp_drop) */
1518 #define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 5)
1519 
1520 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
1521 {
1522 	struct net_device_context *ndc = netdev_priv(dev);
1523 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1524 
1525 	if (!nvdev)
1526 		return -ENODEV;
1527 
1528 	switch (string_set) {
1529 	case ETH_SS_STATS:
1530 		return NETVSC_GLOBAL_STATS_LEN
1531 			+ NETVSC_VF_STATS_LEN
1532 			+ NETVSC_QUEUE_STATS_LEN(nvdev)
1533 			+ NETVSC_PCPU_STATS_LEN;
1534 	default:
1535 		return -EINVAL;
1536 	}
1537 }
1538 
1539 static void netvsc_get_ethtool_stats(struct net_device *dev,
1540 				     struct ethtool_stats *stats, u64 *data)
1541 {
1542 	struct net_device_context *ndc = netdev_priv(dev);
1543 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1544 	const void *nds = &ndc->eth_stats;
1545 	const struct netvsc_stats *qstats;
1546 	struct netvsc_vf_pcpu_stats sum;
1547 	struct netvsc_ethtool_pcpu_stats *pcpu_sum;
1548 	unsigned int start;
1549 	u64 packets, bytes;
1550 	u64 xdp_drop;
1551 	int i, j, cpu;
1552 
1553 	if (!nvdev)
1554 		return;
1555 
1556 	for (i = 0; i < NETVSC_GLOBAL_STATS_LEN; i++)
1557 		data[i] = *(unsigned long *)(nds + netvsc_stats[i].offset);
1558 
1559 	netvsc_get_vf_stats(dev, &sum);
1560 	for (j = 0; j < NETVSC_VF_STATS_LEN; j++)
1561 		data[i++] = *(u64 *)((void *)&sum + vf_stats[j].offset);
1562 
1563 	for (j = 0; j < nvdev->num_chn; j++) {
1564 		qstats = &nvdev->chan_table[j].tx_stats;
1565 
1566 		do {
1567 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1568 			packets = qstats->packets;
1569 			bytes = qstats->bytes;
1570 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1571 		data[i++] = packets;
1572 		data[i++] = bytes;
1573 
1574 		qstats = &nvdev->chan_table[j].rx_stats;
1575 		do {
1576 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
1577 			packets = qstats->packets;
1578 			bytes = qstats->bytes;
1579 			xdp_drop = qstats->xdp_drop;
1580 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
1581 		data[i++] = packets;
1582 		data[i++] = bytes;
1583 		data[i++] = xdp_drop;
1584 	}
1585 
1586 	pcpu_sum = kvmalloc_array(num_possible_cpus(),
1587 				  sizeof(struct netvsc_ethtool_pcpu_stats),
1588 				  GFP_KERNEL);
1589 	netvsc_get_pcpu_stats(dev, pcpu_sum);
1590 	for_each_present_cpu(cpu) {
1591 		struct netvsc_ethtool_pcpu_stats *this_sum = &pcpu_sum[cpu];
1592 
1593 		for (j = 0; j < ARRAY_SIZE(pcpu_stats); j++)
1594 			data[i++] = *(u64 *)((void *)this_sum
1595 					     + pcpu_stats[j].offset);
1596 	}
1597 	kvfree(pcpu_sum);
1598 }
1599 
1600 static void netvsc_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1601 {
1602 	struct net_device_context *ndc = netdev_priv(dev);
1603 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1604 	u8 *p = data;
1605 	int i, cpu;
1606 
1607 	if (!nvdev)
1608 		return;
1609 
1610 	switch (stringset) {
1611 	case ETH_SS_STATS:
1612 		for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++)
1613 			ethtool_sprintf(&p, netvsc_stats[i].name);
1614 
1615 		for (i = 0; i < ARRAY_SIZE(vf_stats); i++)
1616 			ethtool_sprintf(&p, vf_stats[i].name);
1617 
1618 		for (i = 0; i < nvdev->num_chn; i++) {
1619 			ethtool_sprintf(&p, "tx_queue_%u_packets", i);
1620 			ethtool_sprintf(&p, "tx_queue_%u_bytes", i);
1621 			ethtool_sprintf(&p, "rx_queue_%u_packets", i);
1622 			ethtool_sprintf(&p, "rx_queue_%u_bytes", i);
1623 			ethtool_sprintf(&p, "rx_queue_%u_xdp_drop", i);
1624 		}
1625 
1626 		for_each_present_cpu(cpu) {
1627 			for (i = 0; i < ARRAY_SIZE(pcpu_stats); i++)
1628 				ethtool_sprintf(&p, pcpu_stats[i].name, cpu);
1629 		}
1630 
1631 		break;
1632 	}
1633 }
1634 
1635 static int
1636 netvsc_get_rss_hash_opts(struct net_device_context *ndc,
1637 			 struct ethtool_rxnfc *info)
1638 {
1639 	const u32 l4_flag = RXH_L4_B_0_1 | RXH_L4_B_2_3;
1640 
1641 	info->data = RXH_IP_SRC | RXH_IP_DST;
1642 
1643 	switch (info->flow_type) {
1644 	case TCP_V4_FLOW:
1645 		if (ndc->l4_hash & HV_TCP4_L4HASH)
1646 			info->data |= l4_flag;
1647 
1648 		break;
1649 
1650 	case TCP_V6_FLOW:
1651 		if (ndc->l4_hash & HV_TCP6_L4HASH)
1652 			info->data |= l4_flag;
1653 
1654 		break;
1655 
1656 	case UDP_V4_FLOW:
1657 		if (ndc->l4_hash & HV_UDP4_L4HASH)
1658 			info->data |= l4_flag;
1659 
1660 		break;
1661 
1662 	case UDP_V6_FLOW:
1663 		if (ndc->l4_hash & HV_UDP6_L4HASH)
1664 			info->data |= l4_flag;
1665 
1666 		break;
1667 
1668 	case IPV4_FLOW:
1669 	case IPV6_FLOW:
1670 		break;
1671 	default:
1672 		info->data = 0;
1673 		break;
1674 	}
1675 
1676 	return 0;
1677 }
1678 
1679 static int
1680 netvsc_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
1681 		 u32 *rules)
1682 {
1683 	struct net_device_context *ndc = netdev_priv(dev);
1684 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
1685 
1686 	if (!nvdev)
1687 		return -ENODEV;
1688 
1689 	switch (info->cmd) {
1690 	case ETHTOOL_GRXRINGS:
1691 		info->data = nvdev->num_chn;
1692 		return 0;
1693 
1694 	case ETHTOOL_GRXFH:
1695 		return netvsc_get_rss_hash_opts(ndc, info);
1696 	}
1697 	return -EOPNOTSUPP;
1698 }
1699 
1700 static int netvsc_set_rss_hash_opts(struct net_device_context *ndc,
1701 				    struct ethtool_rxnfc *info)
1702 {
1703 	if (info->data == (RXH_IP_SRC | RXH_IP_DST |
1704 			   RXH_L4_B_0_1 | RXH_L4_B_2_3)) {
1705 		switch (info->flow_type) {
1706 		case TCP_V4_FLOW:
1707 			ndc->l4_hash |= HV_TCP4_L4HASH;
1708 			break;
1709 
1710 		case TCP_V6_FLOW:
1711 			ndc->l4_hash |= HV_TCP6_L4HASH;
1712 			break;
1713 
1714 		case UDP_V4_FLOW:
1715 			ndc->l4_hash |= HV_UDP4_L4HASH;
1716 			break;
1717 
1718 		case UDP_V6_FLOW:
1719 			ndc->l4_hash |= HV_UDP6_L4HASH;
1720 			break;
1721 
1722 		default:
1723 			return -EOPNOTSUPP;
1724 		}
1725 
1726 		return 0;
1727 	}
1728 
1729 	if (info->data == (RXH_IP_SRC | RXH_IP_DST)) {
1730 		switch (info->flow_type) {
1731 		case TCP_V4_FLOW:
1732 			ndc->l4_hash &= ~HV_TCP4_L4HASH;
1733 			break;
1734 
1735 		case TCP_V6_FLOW:
1736 			ndc->l4_hash &= ~HV_TCP6_L4HASH;
1737 			break;
1738 
1739 		case UDP_V4_FLOW:
1740 			ndc->l4_hash &= ~HV_UDP4_L4HASH;
1741 			break;
1742 
1743 		case UDP_V6_FLOW:
1744 			ndc->l4_hash &= ~HV_UDP6_L4HASH;
1745 			break;
1746 
1747 		default:
1748 			return -EOPNOTSUPP;
1749 		}
1750 
1751 		return 0;
1752 	}
1753 
1754 	return -EOPNOTSUPP;
1755 }
1756 
1757 static int
1758 netvsc_set_rxnfc(struct net_device *ndev, struct ethtool_rxnfc *info)
1759 {
1760 	struct net_device_context *ndc = netdev_priv(ndev);
1761 
1762 	if (info->cmd == ETHTOOL_SRXFH)
1763 		return netvsc_set_rss_hash_opts(ndc, info);
1764 
1765 	return -EOPNOTSUPP;
1766 }
1767 
1768 static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
1769 {
1770 	return NETVSC_HASH_KEYLEN;
1771 }
1772 
1773 static u32 netvsc_rss_indir_size(struct net_device *dev)
1774 {
1775 	return ITAB_NUM;
1776 }
1777 
1778 static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
1779 			   u8 *hfunc)
1780 {
1781 	struct net_device_context *ndc = netdev_priv(dev);
1782 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1783 	struct rndis_device *rndis_dev;
1784 	int i;
1785 
1786 	if (!ndev)
1787 		return -ENODEV;
1788 
1789 	if (hfunc)
1790 		*hfunc = ETH_RSS_HASH_TOP;	/* Toeplitz */
1791 
1792 	rndis_dev = ndev->extension;
1793 	if (indir) {
1794 		for (i = 0; i < ITAB_NUM; i++)
1795 			indir[i] = ndc->rx_table[i];
1796 	}
1797 
1798 	if (key)
1799 		memcpy(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN);
1800 
1801 	return 0;
1802 }
1803 
1804 static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
1805 			   const u8 *key, const u8 hfunc)
1806 {
1807 	struct net_device_context *ndc = netdev_priv(dev);
1808 	struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
1809 	struct rndis_device *rndis_dev;
1810 	int i;
1811 
1812 	if (!ndev)
1813 		return -ENODEV;
1814 
1815 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
1816 		return -EOPNOTSUPP;
1817 
1818 	rndis_dev = ndev->extension;
1819 	if (indir) {
1820 		for (i = 0; i < ITAB_NUM; i++)
1821 			if (indir[i] >= ndev->num_chn)
1822 				return -EINVAL;
1823 
1824 		for (i = 0; i < ITAB_NUM; i++)
1825 			ndc->rx_table[i] = indir[i];
1826 	}
1827 
1828 	if (!key) {
1829 		if (!indir)
1830 			return 0;
1831 
1832 		key = rndis_dev->rss_key;
1833 	}
1834 
1835 	return rndis_filter_set_rss_param(rndis_dev, key);
1836 }
1837 
1838 /* Hyper-V RNDIS protocol does not have ring in the HW sense.
1839  * It does have pre-allocated receive area which is divided into sections.
1840  */
1841 static void __netvsc_get_ringparam(struct netvsc_device *nvdev,
1842 				   struct ethtool_ringparam *ring)
1843 {
1844 	u32 max_buf_size;
1845 
1846 	ring->rx_pending = nvdev->recv_section_cnt;
1847 	ring->tx_pending = nvdev->send_section_cnt;
1848 
1849 	if (nvdev->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
1850 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
1851 	else
1852 		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
1853 
1854 	ring->rx_max_pending = max_buf_size / nvdev->recv_section_size;
1855 	ring->tx_max_pending = NETVSC_SEND_BUFFER_SIZE
1856 		/ nvdev->send_section_size;
1857 }
1858 
1859 static void netvsc_get_ringparam(struct net_device *ndev,
1860 				 struct ethtool_ringparam *ring)
1861 {
1862 	struct net_device_context *ndevctx = netdev_priv(ndev);
1863 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1864 
1865 	if (!nvdev)
1866 		return;
1867 
1868 	__netvsc_get_ringparam(nvdev, ring);
1869 }
1870 
1871 static int netvsc_set_ringparam(struct net_device *ndev,
1872 				struct ethtool_ringparam *ring)
1873 {
1874 	struct net_device_context *ndevctx = netdev_priv(ndev);
1875 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1876 	struct netvsc_device_info *device_info;
1877 	struct ethtool_ringparam orig;
1878 	u32 new_tx, new_rx;
1879 	int ret = 0;
1880 
1881 	if (!nvdev || nvdev->destroy)
1882 		return -ENODEV;
1883 
1884 	memset(&orig, 0, sizeof(orig));
1885 	__netvsc_get_ringparam(nvdev, &orig);
1886 
1887 	new_tx = clamp_t(u32, ring->tx_pending,
1888 			 NETVSC_MIN_TX_SECTIONS, orig.tx_max_pending);
1889 	new_rx = clamp_t(u32, ring->rx_pending,
1890 			 NETVSC_MIN_RX_SECTIONS, orig.rx_max_pending);
1891 
1892 	if (new_tx == orig.tx_pending &&
1893 	    new_rx == orig.rx_pending)
1894 		return 0;	 /* no change */
1895 
1896 	device_info = netvsc_devinfo_get(nvdev);
1897 
1898 	if (!device_info)
1899 		return -ENOMEM;
1900 
1901 	device_info->send_sections = new_tx;
1902 	device_info->recv_sections = new_rx;
1903 
1904 	ret = netvsc_detach(ndev, nvdev);
1905 	if (ret)
1906 		goto out;
1907 
1908 	ret = netvsc_attach(ndev, device_info);
1909 	if (ret) {
1910 		device_info->send_sections = orig.tx_pending;
1911 		device_info->recv_sections = orig.rx_pending;
1912 
1913 		if (netvsc_attach(ndev, device_info))
1914 			netdev_err(ndev, "restoring ringparam failed");
1915 	}
1916 
1917 out:
1918 	netvsc_devinfo_put(device_info);
1919 	return ret;
1920 }
1921 
1922 static netdev_features_t netvsc_fix_features(struct net_device *ndev,
1923 					     netdev_features_t features)
1924 {
1925 	struct net_device_context *ndevctx = netdev_priv(ndev);
1926 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1927 
1928 	if (!nvdev || nvdev->destroy)
1929 		return features;
1930 
1931 	if ((features & NETIF_F_LRO) && netvsc_xdp_get(nvdev)) {
1932 		features ^= NETIF_F_LRO;
1933 		netdev_info(ndev, "Skip LRO - unsupported with XDP\n");
1934 	}
1935 
1936 	return features;
1937 }
1938 
1939 static int netvsc_set_features(struct net_device *ndev,
1940 			       netdev_features_t features)
1941 {
1942 	netdev_features_t change = features ^ ndev->features;
1943 	struct net_device_context *ndevctx = netdev_priv(ndev);
1944 	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
1945 	struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
1946 	struct ndis_offload_params offloads;
1947 	int ret = 0;
1948 
1949 	if (!nvdev || nvdev->destroy)
1950 		return -ENODEV;
1951 
1952 	if (!(change & NETIF_F_LRO))
1953 		goto syncvf;
1954 
1955 	memset(&offloads, 0, sizeof(struct ndis_offload_params));
1956 
1957 	if (features & NETIF_F_LRO) {
1958 		offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
1959 		offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
1960 	} else {
1961 		offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
1962 		offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
1963 	}
1964 
1965 	ret = rndis_filter_set_offload_params(ndev, nvdev, &offloads);
1966 
1967 	if (ret) {
1968 		features ^= NETIF_F_LRO;
1969 		ndev->features = features;
1970 	}
1971 
1972 syncvf:
1973 	if (!vf_netdev)
1974 		return ret;
1975 
1976 	vf_netdev->wanted_features = features;
1977 	netdev_update_features(vf_netdev);
1978 
1979 	return ret;
1980 }
1981 
1982 static int netvsc_get_regs_len(struct net_device *netdev)
1983 {
1984 	return VRSS_SEND_TAB_SIZE * sizeof(u32);
1985 }
1986 
1987 static void netvsc_get_regs(struct net_device *netdev,
1988 			    struct ethtool_regs *regs, void *p)
1989 {
1990 	struct net_device_context *ndc = netdev_priv(netdev);
1991 	u32 *regs_buff = p;
1992 
1993 	/* increase the version, if buffer format is changed. */
1994 	regs->version = 1;
1995 
1996 	memcpy(regs_buff, ndc->tx_table, VRSS_SEND_TAB_SIZE * sizeof(u32));
1997 }
1998 
1999 static u32 netvsc_get_msglevel(struct net_device *ndev)
2000 {
2001 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
2002 
2003 	return ndev_ctx->msg_enable;
2004 }
2005 
2006 static void netvsc_set_msglevel(struct net_device *ndev, u32 val)
2007 {
2008 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
2009 
2010 	ndev_ctx->msg_enable = val;
2011 }
2012 
2013 static const struct ethtool_ops ethtool_ops = {
2014 	.get_drvinfo	= netvsc_get_drvinfo,
2015 	.get_regs_len	= netvsc_get_regs_len,
2016 	.get_regs	= netvsc_get_regs,
2017 	.get_msglevel	= netvsc_get_msglevel,
2018 	.set_msglevel	= netvsc_set_msglevel,
2019 	.get_link	= ethtool_op_get_link,
2020 	.get_ethtool_stats = netvsc_get_ethtool_stats,
2021 	.get_sset_count = netvsc_get_sset_count,
2022 	.get_strings	= netvsc_get_strings,
2023 	.get_channels   = netvsc_get_channels,
2024 	.set_channels   = netvsc_set_channels,
2025 	.get_ts_info	= ethtool_op_get_ts_info,
2026 	.get_rxnfc	= netvsc_get_rxnfc,
2027 	.set_rxnfc	= netvsc_set_rxnfc,
2028 	.get_rxfh_key_size = netvsc_get_rxfh_key_size,
2029 	.get_rxfh_indir_size = netvsc_rss_indir_size,
2030 	.get_rxfh	= netvsc_get_rxfh,
2031 	.set_rxfh	= netvsc_set_rxfh,
2032 	.get_link_ksettings = netvsc_get_link_ksettings,
2033 	.set_link_ksettings = netvsc_set_link_ksettings,
2034 	.get_ringparam	= netvsc_get_ringparam,
2035 	.set_ringparam	= netvsc_set_ringparam,
2036 };
2037 
2038 static const struct net_device_ops device_ops = {
2039 	.ndo_open =			netvsc_open,
2040 	.ndo_stop =			netvsc_close,
2041 	.ndo_start_xmit =		netvsc_start_xmit,
2042 	.ndo_change_rx_flags =		netvsc_change_rx_flags,
2043 	.ndo_set_rx_mode =		netvsc_set_rx_mode,
2044 	.ndo_fix_features =		netvsc_fix_features,
2045 	.ndo_set_features =		netvsc_set_features,
2046 	.ndo_change_mtu =		netvsc_change_mtu,
2047 	.ndo_validate_addr =		eth_validate_addr,
2048 	.ndo_set_mac_address =		netvsc_set_mac_addr,
2049 	.ndo_select_queue =		netvsc_select_queue,
2050 	.ndo_get_stats64 =		netvsc_get_stats64,
2051 	.ndo_bpf =			netvsc_bpf,
2052 };
2053 
2054 /*
2055  * Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
2056  * down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
2057  * present send GARP packet to network peers with netif_notify_peers().
2058  */
2059 static void netvsc_link_change(struct work_struct *w)
2060 {
2061 	struct net_device_context *ndev_ctx =
2062 		container_of(w, struct net_device_context, dwork.work);
2063 	struct hv_device *device_obj = ndev_ctx->device_ctx;
2064 	struct net_device *net = hv_get_drvdata(device_obj);
2065 	unsigned long flags, next_reconfig, delay;
2066 	struct netvsc_reconfig *event = NULL;
2067 	struct netvsc_device *net_device;
2068 	struct rndis_device *rdev;
2069 	bool reschedule = false;
2070 
2071 	/* if changes are happening, comeback later */
2072 	if (!rtnl_trylock()) {
2073 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
2074 		return;
2075 	}
2076 
2077 	net_device = rtnl_dereference(ndev_ctx->nvdev);
2078 	if (!net_device)
2079 		goto out_unlock;
2080 
2081 	rdev = net_device->extension;
2082 
2083 	next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
2084 	if (time_is_after_jiffies(next_reconfig)) {
2085 		/* link_watch only sends one notification with current state
2086 		 * per second, avoid doing reconfig more frequently. Handle
2087 		 * wrap around.
2088 		 */
2089 		delay = next_reconfig - jiffies;
2090 		delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
2091 		schedule_delayed_work(&ndev_ctx->dwork, delay);
2092 		goto out_unlock;
2093 	}
2094 	ndev_ctx->last_reconfig = jiffies;
2095 
2096 	spin_lock_irqsave(&ndev_ctx->lock, flags);
2097 	if (!list_empty(&ndev_ctx->reconfig_events)) {
2098 		event = list_first_entry(&ndev_ctx->reconfig_events,
2099 					 struct netvsc_reconfig, list);
2100 		list_del(&event->list);
2101 		reschedule = !list_empty(&ndev_ctx->reconfig_events);
2102 	}
2103 	spin_unlock_irqrestore(&ndev_ctx->lock, flags);
2104 
2105 	if (!event)
2106 		goto out_unlock;
2107 
2108 	switch (event->event) {
2109 		/* Only the following events are possible due to the check in
2110 		 * netvsc_linkstatus_callback()
2111 		 */
2112 	case RNDIS_STATUS_MEDIA_CONNECT:
2113 		if (rdev->link_state) {
2114 			rdev->link_state = false;
2115 			netif_carrier_on(net);
2116 			netvsc_tx_enable(net_device, net);
2117 		} else {
2118 			__netdev_notify_peers(net);
2119 		}
2120 		kfree(event);
2121 		break;
2122 	case RNDIS_STATUS_MEDIA_DISCONNECT:
2123 		if (!rdev->link_state) {
2124 			rdev->link_state = true;
2125 			netif_carrier_off(net);
2126 			netvsc_tx_disable(net_device, net);
2127 		}
2128 		kfree(event);
2129 		break;
2130 	case RNDIS_STATUS_NETWORK_CHANGE:
2131 		/* Only makes sense if carrier is present */
2132 		if (!rdev->link_state) {
2133 			rdev->link_state = true;
2134 			netif_carrier_off(net);
2135 			netvsc_tx_disable(net_device, net);
2136 			event->event = RNDIS_STATUS_MEDIA_CONNECT;
2137 			spin_lock_irqsave(&ndev_ctx->lock, flags);
2138 			list_add(&event->list, &ndev_ctx->reconfig_events);
2139 			spin_unlock_irqrestore(&ndev_ctx->lock, flags);
2140 			reschedule = true;
2141 		}
2142 		break;
2143 	}
2144 
2145 	rtnl_unlock();
2146 
2147 	/* link_watch only sends one notification with current state per
2148 	 * second, handle next reconfig event in 2 seconds.
2149 	 */
2150 	if (reschedule)
2151 		schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
2152 
2153 	return;
2154 
2155 out_unlock:
2156 	rtnl_unlock();
2157 }
2158 
2159 static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
2160 {
2161 	struct net_device_context *net_device_ctx;
2162 	struct net_device *dev;
2163 
2164 	dev = netdev_master_upper_dev_get(vf_netdev);
2165 	if (!dev || dev->netdev_ops != &device_ops)
2166 		return NULL;	/* not a netvsc device */
2167 
2168 	net_device_ctx = netdev_priv(dev);
2169 	if (!rtnl_dereference(net_device_ctx->nvdev))
2170 		return NULL;	/* device is removed */
2171 
2172 	return dev;
2173 }
2174 
2175 /* Called when VF is injecting data into network stack.
2176  * Change the associated network device from VF to netvsc.
2177  * note: already called with rcu_read_lock
2178  */
2179 static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
2180 {
2181 	struct sk_buff *skb = *pskb;
2182 	struct net_device *ndev = rcu_dereference(skb->dev->rx_handler_data);
2183 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
2184 	struct netvsc_vf_pcpu_stats *pcpu_stats
2185 		 = this_cpu_ptr(ndev_ctx->vf_stats);
2186 
2187 	skb = skb_share_check(skb, GFP_ATOMIC);
2188 	if (unlikely(!skb))
2189 		return RX_HANDLER_CONSUMED;
2190 
2191 	*pskb = skb;
2192 
2193 	skb->dev = ndev;
2194 
2195 	u64_stats_update_begin(&pcpu_stats->syncp);
2196 	pcpu_stats->rx_packets++;
2197 	pcpu_stats->rx_bytes += skb->len;
2198 	u64_stats_update_end(&pcpu_stats->syncp);
2199 
2200 	return RX_HANDLER_ANOTHER;
2201 }
2202 
2203 static int netvsc_vf_join(struct net_device *vf_netdev,
2204 			  struct net_device *ndev)
2205 {
2206 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
2207 	int ret;
2208 
2209 	ret = netdev_rx_handler_register(vf_netdev,
2210 					 netvsc_vf_handle_frame, ndev);
2211 	if (ret != 0) {
2212 		netdev_err(vf_netdev,
2213 			   "can not register netvsc VF receive handler (err = %d)\n",
2214 			   ret);
2215 		goto rx_handler_failed;
2216 	}
2217 
2218 	ret = netdev_master_upper_dev_link(vf_netdev, ndev,
2219 					   NULL, NULL, NULL);
2220 	if (ret != 0) {
2221 		netdev_err(vf_netdev,
2222 			   "can not set master device %s (err = %d)\n",
2223 			   ndev->name, ret);
2224 		goto upper_link_failed;
2225 	}
2226 
2227 	/* set slave flag before open to prevent IPv6 addrconf */
2228 	vf_netdev->flags |= IFF_SLAVE;
2229 
2230 	schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
2231 
2232 	call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
2233 
2234 	netdev_info(vf_netdev, "joined to %s\n", ndev->name);
2235 	return 0;
2236 
2237 upper_link_failed:
2238 	netdev_rx_handler_unregister(vf_netdev);
2239 rx_handler_failed:
2240 	return ret;
2241 }
2242 
2243 static void __netvsc_vf_setup(struct net_device *ndev,
2244 			      struct net_device *vf_netdev)
2245 {
2246 	int ret;
2247 
2248 	/* Align MTU of VF with master */
2249 	ret = dev_set_mtu(vf_netdev, ndev->mtu);
2250 	if (ret)
2251 		netdev_warn(vf_netdev,
2252 			    "unable to change mtu to %u\n", ndev->mtu);
2253 
2254 	/* set multicast etc flags on VF */
2255 	dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE, NULL);
2256 
2257 	/* sync address list from ndev to VF */
2258 	netif_addr_lock_bh(ndev);
2259 	dev_uc_sync(vf_netdev, ndev);
2260 	dev_mc_sync(vf_netdev, ndev);
2261 	netif_addr_unlock_bh(ndev);
2262 
2263 	if (netif_running(ndev)) {
2264 		ret = dev_open(vf_netdev, NULL);
2265 		if (ret)
2266 			netdev_warn(vf_netdev,
2267 				    "unable to open: %d\n", ret);
2268 	}
2269 }
2270 
2271 /* Setup VF as slave of the synthetic device.
2272  * Runs in workqueue to avoid recursion in netlink callbacks.
2273  */
2274 static void netvsc_vf_setup(struct work_struct *w)
2275 {
2276 	struct net_device_context *ndev_ctx
2277 		= container_of(w, struct net_device_context, vf_takeover.work);
2278 	struct net_device *ndev = hv_get_drvdata(ndev_ctx->device_ctx);
2279 	struct net_device *vf_netdev;
2280 
2281 	if (!rtnl_trylock()) {
2282 		schedule_delayed_work(&ndev_ctx->vf_takeover, 0);
2283 		return;
2284 	}
2285 
2286 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
2287 	if (vf_netdev)
2288 		__netvsc_vf_setup(ndev, vf_netdev);
2289 
2290 	rtnl_unlock();
2291 }
2292 
2293 /* Find netvsc by VF serial number.
2294  * The PCI hyperv controller records the serial number as the slot kobj name.
2295  */
2296 static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
2297 {
2298 	struct device *parent = vf_netdev->dev.parent;
2299 	struct net_device_context *ndev_ctx;
2300 	struct net_device *ndev;
2301 	struct pci_dev *pdev;
2302 	u32 serial;
2303 
2304 	if (!parent || !dev_is_pci(parent))
2305 		return NULL; /* not a PCI device */
2306 
2307 	pdev = to_pci_dev(parent);
2308 	if (!pdev->slot) {
2309 		netdev_notice(vf_netdev, "no PCI slot information\n");
2310 		return NULL;
2311 	}
2312 
2313 	if (kstrtou32(pci_slot_name(pdev->slot), 10, &serial)) {
2314 		netdev_notice(vf_netdev, "Invalid vf serial:%s\n",
2315 			      pci_slot_name(pdev->slot));
2316 		return NULL;
2317 	}
2318 
2319 	list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
2320 		if (!ndev_ctx->vf_alloc)
2321 			continue;
2322 
2323 		if (ndev_ctx->vf_serial != serial)
2324 			continue;
2325 
2326 		ndev = hv_get_drvdata(ndev_ctx->device_ctx);
2327 		if (ndev->addr_len != vf_netdev->addr_len ||
2328 		    memcmp(ndev->perm_addr, vf_netdev->perm_addr,
2329 			   ndev->addr_len) != 0)
2330 			continue;
2331 
2332 		return ndev;
2333 
2334 	}
2335 
2336 	netdev_notice(vf_netdev,
2337 		      "no netdev found for vf serial:%u\n", serial);
2338 	return NULL;
2339 }
2340 
2341 static int netvsc_register_vf(struct net_device *vf_netdev)
2342 {
2343 	struct net_device_context *net_device_ctx;
2344 	struct netvsc_device *netvsc_dev;
2345 	struct bpf_prog *prog;
2346 	struct net_device *ndev;
2347 	int ret;
2348 
2349 	if (vf_netdev->addr_len != ETH_ALEN)
2350 		return NOTIFY_DONE;
2351 
2352 	ndev = get_netvsc_byslot(vf_netdev);
2353 	if (!ndev)
2354 		return NOTIFY_DONE;
2355 
2356 	net_device_ctx = netdev_priv(ndev);
2357 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
2358 	if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
2359 		return NOTIFY_DONE;
2360 
2361 	/* if synthetic interface is a different namespace,
2362 	 * then move the VF to that namespace; join will be
2363 	 * done again in that context.
2364 	 */
2365 	if (!net_eq(dev_net(ndev), dev_net(vf_netdev))) {
2366 		ret = dev_change_net_namespace(vf_netdev,
2367 					       dev_net(ndev), "eth%d");
2368 		if (ret)
2369 			netdev_err(vf_netdev,
2370 				   "could not move to same namespace as %s: %d\n",
2371 				   ndev->name, ret);
2372 		else
2373 			netdev_info(vf_netdev,
2374 				    "VF moved to namespace with: %s\n",
2375 				    ndev->name);
2376 		return NOTIFY_DONE;
2377 	}
2378 
2379 	netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
2380 
2381 	if (netvsc_vf_join(vf_netdev, ndev) != 0)
2382 		return NOTIFY_DONE;
2383 
2384 	dev_hold(vf_netdev);
2385 	rcu_assign_pointer(net_device_ctx->vf_netdev, vf_netdev);
2386 
2387 	vf_netdev->wanted_features = ndev->features;
2388 	netdev_update_features(vf_netdev);
2389 
2390 	prog = netvsc_xdp_get(netvsc_dev);
2391 	netvsc_vf_setxdp(vf_netdev, prog);
2392 
2393 	return NOTIFY_OK;
2394 }
2395 
2396 /* Change the data path when VF UP/DOWN/CHANGE are detected.
2397  *
2398  * Typically a UP or DOWN event is followed by a CHANGE event, so
2399  * net_device_ctx->data_path_is_vf is used to cache the current data path
2400  * to avoid the duplicate call of netvsc_switch_datapath() and the duplicate
2401  * message.
2402  *
2403  * During hibernation, if a VF NIC driver (e.g. mlx5) preserves the network
2404  * interface, there is only the CHANGE event and no UP or DOWN event.
2405  */
2406 static int netvsc_vf_changed(struct net_device *vf_netdev, unsigned long event)
2407 {
2408 	struct net_device_context *net_device_ctx;
2409 	struct netvsc_device *netvsc_dev;
2410 	struct net_device *ndev;
2411 	bool vf_is_up = false;
2412 	int ret;
2413 
2414 	if (event != NETDEV_GOING_DOWN)
2415 		vf_is_up = netif_running(vf_netdev);
2416 
2417 	ndev = get_netvsc_byref(vf_netdev);
2418 	if (!ndev)
2419 		return NOTIFY_DONE;
2420 
2421 	net_device_ctx = netdev_priv(ndev);
2422 	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
2423 	if (!netvsc_dev)
2424 		return NOTIFY_DONE;
2425 
2426 	if (net_device_ctx->data_path_is_vf == vf_is_up)
2427 		return NOTIFY_OK;
2428 
2429 	ret = netvsc_switch_datapath(ndev, vf_is_up);
2430 
2431 	if (ret) {
2432 		netdev_err(ndev,
2433 			   "Data path failed to switch %s VF: %s, err: %d\n",
2434 			   vf_is_up ? "to" : "from", vf_netdev->name, ret);
2435 		return NOTIFY_DONE;
2436 	} else {
2437 		netdev_info(ndev, "Data path switched %s VF: %s\n",
2438 			    vf_is_up ? "to" : "from", vf_netdev->name);
2439 	}
2440 
2441 	return NOTIFY_OK;
2442 }
2443 
2444 static int netvsc_unregister_vf(struct net_device *vf_netdev)
2445 {
2446 	struct net_device *ndev;
2447 	struct net_device_context *net_device_ctx;
2448 
2449 	ndev = get_netvsc_byref(vf_netdev);
2450 	if (!ndev)
2451 		return NOTIFY_DONE;
2452 
2453 	net_device_ctx = netdev_priv(ndev);
2454 	cancel_delayed_work_sync(&net_device_ctx->vf_takeover);
2455 
2456 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
2457 
2458 	netvsc_vf_setxdp(vf_netdev, NULL);
2459 
2460 	netdev_rx_handler_unregister(vf_netdev);
2461 	netdev_upper_dev_unlink(vf_netdev, ndev);
2462 	RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
2463 	dev_put(vf_netdev);
2464 
2465 	return NOTIFY_OK;
2466 }
2467 
2468 static int netvsc_probe(struct hv_device *dev,
2469 			const struct hv_vmbus_device_id *dev_id)
2470 {
2471 	struct net_device *net = NULL;
2472 	struct net_device_context *net_device_ctx;
2473 	struct netvsc_device_info *device_info = NULL;
2474 	struct netvsc_device *nvdev;
2475 	int ret = -ENOMEM;
2476 
2477 	net = alloc_etherdev_mq(sizeof(struct net_device_context),
2478 				VRSS_CHANNEL_MAX);
2479 	if (!net)
2480 		goto no_net;
2481 
2482 	netif_carrier_off(net);
2483 
2484 	netvsc_init_settings(net);
2485 
2486 	net_device_ctx = netdev_priv(net);
2487 	net_device_ctx->device_ctx = dev;
2488 	net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
2489 	if (netif_msg_probe(net_device_ctx))
2490 		netdev_dbg(net, "netvsc msg_enable: %d\n",
2491 			   net_device_ctx->msg_enable);
2492 
2493 	hv_set_drvdata(dev, net);
2494 
2495 	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
2496 
2497 	spin_lock_init(&net_device_ctx->lock);
2498 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
2499 	INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
2500 
2501 	net_device_ctx->vf_stats
2502 		= netdev_alloc_pcpu_stats(struct netvsc_vf_pcpu_stats);
2503 	if (!net_device_ctx->vf_stats)
2504 		goto no_stats;
2505 
2506 	net->netdev_ops = &device_ops;
2507 	net->ethtool_ops = &ethtool_ops;
2508 	SET_NETDEV_DEV(net, &dev->device);
2509 
2510 	/* We always need headroom for rndis header */
2511 	net->needed_headroom = RNDIS_AND_PPI_SIZE;
2512 
2513 	/* Initialize the number of queues to be 1, we may change it if more
2514 	 * channels are offered later.
2515 	 */
2516 	netif_set_real_num_tx_queues(net, 1);
2517 	netif_set_real_num_rx_queues(net, 1);
2518 
2519 	/* Notify the netvsc driver of the new device */
2520 	device_info = netvsc_devinfo_get(NULL);
2521 
2522 	if (!device_info) {
2523 		ret = -ENOMEM;
2524 		goto devinfo_failed;
2525 	}
2526 
2527 	nvdev = rndis_filter_device_add(dev, device_info);
2528 	if (IS_ERR(nvdev)) {
2529 		ret = PTR_ERR(nvdev);
2530 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
2531 		goto rndis_failed;
2532 	}
2533 
2534 	memcpy(net->dev_addr, device_info->mac_adr, ETH_ALEN);
2535 
2536 	/* We must get rtnl lock before scheduling nvdev->subchan_work,
2537 	 * otherwise netvsc_subchan_work() can get rtnl lock first and wait
2538 	 * all subchannels to show up, but that may not happen because
2539 	 * netvsc_probe() can't get rtnl lock and as a result vmbus_onoffer()
2540 	 * -> ... -> device_add() -> ... -> __device_attach() can't get
2541 	 * the device lock, so all the subchannels can't be processed --
2542 	 * finally netvsc_subchan_work() hangs forever.
2543 	 */
2544 	rtnl_lock();
2545 
2546 	if (nvdev->num_chn > 1)
2547 		schedule_work(&nvdev->subchan_work);
2548 
2549 	/* hw_features computed in rndis_netdev_set_hwcaps() */
2550 	net->features = net->hw_features |
2551 		NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX |
2552 		NETIF_F_HW_VLAN_CTAG_RX;
2553 	net->vlan_features = net->features;
2554 
2555 	netdev_lockdep_set_classes(net);
2556 
2557 	/* MTU range: 68 - 1500 or 65521 */
2558 	net->min_mtu = NETVSC_MTU_MIN;
2559 	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
2560 		net->max_mtu = NETVSC_MTU - ETH_HLEN;
2561 	else
2562 		net->max_mtu = ETH_DATA_LEN;
2563 
2564 	nvdev->tx_disable = false;
2565 
2566 	ret = register_netdevice(net);
2567 	if (ret != 0) {
2568 		pr_err("Unable to register netdev.\n");
2569 		goto register_failed;
2570 	}
2571 
2572 	list_add(&net_device_ctx->list, &netvsc_dev_list);
2573 	rtnl_unlock();
2574 
2575 	netvsc_devinfo_put(device_info);
2576 	return 0;
2577 
2578 register_failed:
2579 	rtnl_unlock();
2580 	rndis_filter_device_remove(dev, nvdev);
2581 rndis_failed:
2582 	netvsc_devinfo_put(device_info);
2583 devinfo_failed:
2584 	free_percpu(net_device_ctx->vf_stats);
2585 no_stats:
2586 	hv_set_drvdata(dev, NULL);
2587 	free_netdev(net);
2588 no_net:
2589 	return ret;
2590 }
2591 
2592 static int netvsc_remove(struct hv_device *dev)
2593 {
2594 	struct net_device_context *ndev_ctx;
2595 	struct net_device *vf_netdev, *net;
2596 	struct netvsc_device *nvdev;
2597 
2598 	net = hv_get_drvdata(dev);
2599 	if (net == NULL) {
2600 		dev_err(&dev->device, "No net device to remove\n");
2601 		return 0;
2602 	}
2603 
2604 	ndev_ctx = netdev_priv(net);
2605 
2606 	cancel_delayed_work_sync(&ndev_ctx->dwork);
2607 
2608 	rtnl_lock();
2609 	nvdev = rtnl_dereference(ndev_ctx->nvdev);
2610 	if (nvdev) {
2611 		cancel_work_sync(&nvdev->subchan_work);
2612 		netvsc_xdp_set(net, NULL, NULL, nvdev);
2613 	}
2614 
2615 	/*
2616 	 * Call to the vsc driver to let it know that the device is being
2617 	 * removed. Also blocks mtu and channel changes.
2618 	 */
2619 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
2620 	if (vf_netdev)
2621 		netvsc_unregister_vf(vf_netdev);
2622 
2623 	if (nvdev)
2624 		rndis_filter_device_remove(dev, nvdev);
2625 
2626 	unregister_netdevice(net);
2627 	list_del(&ndev_ctx->list);
2628 
2629 	rtnl_unlock();
2630 
2631 	hv_set_drvdata(dev, NULL);
2632 
2633 	free_percpu(ndev_ctx->vf_stats);
2634 	free_netdev(net);
2635 	return 0;
2636 }
2637 
2638 static int netvsc_suspend(struct hv_device *dev)
2639 {
2640 	struct net_device_context *ndev_ctx;
2641 	struct netvsc_device *nvdev;
2642 	struct net_device *net;
2643 	int ret;
2644 
2645 	net = hv_get_drvdata(dev);
2646 
2647 	ndev_ctx = netdev_priv(net);
2648 	cancel_delayed_work_sync(&ndev_ctx->dwork);
2649 
2650 	rtnl_lock();
2651 
2652 	nvdev = rtnl_dereference(ndev_ctx->nvdev);
2653 	if (nvdev == NULL) {
2654 		ret = -ENODEV;
2655 		goto out;
2656 	}
2657 
2658 	/* Save the current config info */
2659 	ndev_ctx->saved_netvsc_dev_info = netvsc_devinfo_get(nvdev);
2660 
2661 	ret = netvsc_detach(net, nvdev);
2662 out:
2663 	rtnl_unlock();
2664 
2665 	return ret;
2666 }
2667 
2668 static int netvsc_resume(struct hv_device *dev)
2669 {
2670 	struct net_device *net = hv_get_drvdata(dev);
2671 	struct net_device_context *net_device_ctx;
2672 	struct netvsc_device_info *device_info;
2673 	int ret;
2674 
2675 	rtnl_lock();
2676 
2677 	net_device_ctx = netdev_priv(net);
2678 
2679 	/* Reset the data path to the netvsc NIC before re-opening the vmbus
2680 	 * channel. Later netvsc_netdev_event() will switch the data path to
2681 	 * the VF upon the UP or CHANGE event.
2682 	 */
2683 	net_device_ctx->data_path_is_vf = false;
2684 	device_info = net_device_ctx->saved_netvsc_dev_info;
2685 
2686 	ret = netvsc_attach(net, device_info);
2687 
2688 	netvsc_devinfo_put(device_info);
2689 	net_device_ctx->saved_netvsc_dev_info = NULL;
2690 
2691 	rtnl_unlock();
2692 
2693 	return ret;
2694 }
2695 static const struct hv_vmbus_device_id id_table[] = {
2696 	/* Network guid */
2697 	{ HV_NIC_GUID, },
2698 	{ },
2699 };
2700 
2701 MODULE_DEVICE_TABLE(vmbus, id_table);
2702 
2703 /* The one and only one */
2704 static struct  hv_driver netvsc_drv = {
2705 	.name = KBUILD_MODNAME,
2706 	.id_table = id_table,
2707 	.probe = netvsc_probe,
2708 	.remove = netvsc_remove,
2709 	.suspend = netvsc_suspend,
2710 	.resume = netvsc_resume,
2711 	.driver = {
2712 		.probe_type = PROBE_FORCE_SYNCHRONOUS,
2713 	},
2714 };
2715 
2716 /*
2717  * On Hyper-V, every VF interface is matched with a corresponding
2718  * synthetic interface. The synthetic interface is presented first
2719  * to the guest. When the corresponding VF instance is registered,
2720  * we will take care of switching the data path.
2721  */
2722 static int netvsc_netdev_event(struct notifier_block *this,
2723 			       unsigned long event, void *ptr)
2724 {
2725 	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
2726 
2727 	/* Skip our own events */
2728 	if (event_dev->netdev_ops == &device_ops)
2729 		return NOTIFY_DONE;
2730 
2731 	/* Avoid non-Ethernet type devices */
2732 	if (event_dev->type != ARPHRD_ETHER)
2733 		return NOTIFY_DONE;
2734 
2735 	/* Avoid Vlan dev with same MAC registering as VF */
2736 	if (is_vlan_dev(event_dev))
2737 		return NOTIFY_DONE;
2738 
2739 	/* Avoid Bonding master dev with same MAC registering as VF */
2740 	if ((event_dev->priv_flags & IFF_BONDING) &&
2741 	    (event_dev->flags & IFF_MASTER))
2742 		return NOTIFY_DONE;
2743 
2744 	switch (event) {
2745 	case NETDEV_REGISTER:
2746 		return netvsc_register_vf(event_dev);
2747 	case NETDEV_UNREGISTER:
2748 		return netvsc_unregister_vf(event_dev);
2749 	case NETDEV_UP:
2750 	case NETDEV_DOWN:
2751 	case NETDEV_CHANGE:
2752 	case NETDEV_GOING_DOWN:
2753 		return netvsc_vf_changed(event_dev, event);
2754 	default:
2755 		return NOTIFY_DONE;
2756 	}
2757 }
2758 
2759 static struct notifier_block netvsc_netdev_notifier = {
2760 	.notifier_call = netvsc_netdev_event,
2761 };
2762 
2763 static void __exit netvsc_drv_exit(void)
2764 {
2765 	unregister_netdevice_notifier(&netvsc_netdev_notifier);
2766 	vmbus_driver_unregister(&netvsc_drv);
2767 }
2768 
2769 static int __init netvsc_drv_init(void)
2770 {
2771 	int ret;
2772 
2773 	if (ring_size < RING_SIZE_MIN) {
2774 		ring_size = RING_SIZE_MIN;
2775 		pr_info("Increased ring_size to %u (min allowed)\n",
2776 			ring_size);
2777 	}
2778 	netvsc_ring_bytes = ring_size * PAGE_SIZE;
2779 
2780 	ret = vmbus_driver_register(&netvsc_drv);
2781 	if (ret)
2782 		return ret;
2783 
2784 	register_netdevice_notifier(&netvsc_netdev_notifier);
2785 	return 0;
2786 }
2787 
2788 MODULE_LICENSE("GPL");
2789 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
2790 
2791 module_init(netvsc_drv_init);
2792 module_exit(netvsc_drv_exit);
2793