xref: /openbmc/linux/drivers/net/virtio_net.c (revision 853618d5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* A network driver using virtio.
3  *
4  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
5  */
6 //#define DEBUG
7 #include <linux/netdevice.h>
8 #include <linux/etherdevice.h>
9 #include <linux/ethtool.h>
10 #include <linux/module.h>
11 #include <linux/virtio.h>
12 #include <linux/virtio_net.h>
13 #include <linux/bpf.h>
14 #include <linux/bpf_trace.h>
15 #include <linux/scatterlist.h>
16 #include <linux/if_vlan.h>
17 #include <linux/slab.h>
18 #include <linux/cpu.h>
19 #include <linux/average.h>
20 #include <linux/filter.h>
21 #include <linux/kernel.h>
22 #include <net/route.h>
23 #include <net/xdp.h>
24 #include <net/net_failover.h>
25 
26 static int napi_weight = NAPI_POLL_WEIGHT;
27 module_param(napi_weight, int, 0444);
28 
29 static bool csum = true, gso = true, napi_tx = true;
30 module_param(csum, bool, 0444);
31 module_param(gso, bool, 0444);
32 module_param(napi_tx, bool, 0644);
33 
34 /* FIXME: MTU in config. */
35 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
36 #define GOOD_COPY_LEN	128
37 
38 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
39 
40 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
41 #define VIRTIO_XDP_HEADROOM 256
42 
43 /* Separating two types of XDP xmit */
44 #define VIRTIO_XDP_TX		BIT(0)
45 #define VIRTIO_XDP_REDIR	BIT(1)
46 
47 #define VIRTIO_XDP_FLAG	BIT(0)
48 
49 /* RX packet size EWMA. The average packet size is used to determine the packet
50  * buffer size when refilling RX rings. As the entire RX ring may be refilled
51  * at once, the weight is chosen so that the EWMA will be insensitive to short-
52  * term, transient changes in packet size.
53  */
54 DECLARE_EWMA(pkt_len, 0, 64)
55 
56 #define VIRTNET_DRIVER_VERSION "1.0.0"
57 
58 static const unsigned long guest_offloads[] = {
59 	VIRTIO_NET_F_GUEST_TSO4,
60 	VIRTIO_NET_F_GUEST_TSO6,
61 	VIRTIO_NET_F_GUEST_ECN,
62 	VIRTIO_NET_F_GUEST_UFO,
63 	VIRTIO_NET_F_GUEST_CSUM,
64 	VIRTIO_NET_F_GUEST_USO4,
65 	VIRTIO_NET_F_GUEST_USO6
66 };
67 
68 #define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
69 				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
70 				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
71 				(1ULL << VIRTIO_NET_F_GUEST_UFO)  | \
72 				(1ULL << VIRTIO_NET_F_GUEST_USO4) | \
73 				(1ULL << VIRTIO_NET_F_GUEST_USO6))
74 
75 struct virtnet_stat_desc {
76 	char desc[ETH_GSTRING_LEN];
77 	size_t offset;
78 };
79 
80 struct virtnet_sq_stats {
81 	struct u64_stats_sync syncp;
82 	u64 packets;
83 	u64 bytes;
84 	u64 xdp_tx;
85 	u64 xdp_tx_drops;
86 	u64 kicks;
87 	u64 tx_timeouts;
88 };
89 
90 struct virtnet_rq_stats {
91 	struct u64_stats_sync syncp;
92 	u64 packets;
93 	u64 bytes;
94 	u64 drops;
95 	u64 xdp_packets;
96 	u64 xdp_tx;
97 	u64 xdp_redirects;
98 	u64 xdp_drops;
99 	u64 kicks;
100 };
101 
102 #define VIRTNET_SQ_STAT(m)	offsetof(struct virtnet_sq_stats, m)
103 #define VIRTNET_RQ_STAT(m)	offsetof(struct virtnet_rq_stats, m)
104 
105 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
106 	{ "packets",		VIRTNET_SQ_STAT(packets) },
107 	{ "bytes",		VIRTNET_SQ_STAT(bytes) },
108 	{ "xdp_tx",		VIRTNET_SQ_STAT(xdp_tx) },
109 	{ "xdp_tx_drops",	VIRTNET_SQ_STAT(xdp_tx_drops) },
110 	{ "kicks",		VIRTNET_SQ_STAT(kicks) },
111 	{ "tx_timeouts",	VIRTNET_SQ_STAT(tx_timeouts) },
112 };
113 
114 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
115 	{ "packets",		VIRTNET_RQ_STAT(packets) },
116 	{ "bytes",		VIRTNET_RQ_STAT(bytes) },
117 	{ "drops",		VIRTNET_RQ_STAT(drops) },
118 	{ "xdp_packets",	VIRTNET_RQ_STAT(xdp_packets) },
119 	{ "xdp_tx",		VIRTNET_RQ_STAT(xdp_tx) },
120 	{ "xdp_redirects",	VIRTNET_RQ_STAT(xdp_redirects) },
121 	{ "xdp_drops",		VIRTNET_RQ_STAT(xdp_drops) },
122 	{ "kicks",		VIRTNET_RQ_STAT(kicks) },
123 };
124 
125 #define VIRTNET_SQ_STATS_LEN	ARRAY_SIZE(virtnet_sq_stats_desc)
126 #define VIRTNET_RQ_STATS_LEN	ARRAY_SIZE(virtnet_rq_stats_desc)
127 
128 /* Internal representation of a send virtqueue */
129 struct send_queue {
130 	/* Virtqueue associated with this send _queue */
131 	struct virtqueue *vq;
132 
133 	/* TX: fragments + linear part + virtio header */
134 	struct scatterlist sg[MAX_SKB_FRAGS + 2];
135 
136 	/* Name of the send queue: output.$index */
137 	char name[16];
138 
139 	struct virtnet_sq_stats stats;
140 
141 	struct napi_struct napi;
142 
143 	/* Record whether sq is in reset state. */
144 	bool reset;
145 };
146 
147 /* Internal representation of a receive virtqueue */
148 struct receive_queue {
149 	/* Virtqueue associated with this receive_queue */
150 	struct virtqueue *vq;
151 
152 	struct napi_struct napi;
153 
154 	struct bpf_prog __rcu *xdp_prog;
155 
156 	struct virtnet_rq_stats stats;
157 
158 	/* Chain pages by the private ptr. */
159 	struct page *pages;
160 
161 	/* Average packet length for mergeable receive buffers. */
162 	struct ewma_pkt_len mrg_avg_pkt_len;
163 
164 	/* Page frag for packet buffer allocation. */
165 	struct page_frag alloc_frag;
166 
167 	/* RX: fragments + linear part + virtio header */
168 	struct scatterlist sg[MAX_SKB_FRAGS + 2];
169 
170 	/* Min single buffer size for mergeable buffers case. */
171 	unsigned int min_buf_len;
172 
173 	/* Name of this receive queue: input.$index */
174 	char name[16];
175 
176 	struct xdp_rxq_info xdp_rxq;
177 };
178 
179 /* This structure can contain rss message with maximum settings for indirection table and keysize
180  * Note, that default structure that describes RSS configuration virtio_net_rss_config
181  * contains same info but can't handle table values.
182  * In any case, structure would be passed to virtio hw through sg_buf split by parts
183  * because table sizes may be differ according to the device configuration.
184  */
185 #define VIRTIO_NET_RSS_MAX_KEY_SIZE     40
186 #define VIRTIO_NET_RSS_MAX_TABLE_LEN    128
187 struct virtio_net_ctrl_rss {
188 	u32 hash_types;
189 	u16 indirection_table_mask;
190 	u16 unclassified_queue;
191 	u16 indirection_table[VIRTIO_NET_RSS_MAX_TABLE_LEN];
192 	u16 max_tx_vq;
193 	u8 hash_key_length;
194 	u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];
195 };
196 
197 /* Control VQ buffers: protected by the rtnl lock */
198 struct control_buf {
199 	struct virtio_net_ctrl_hdr hdr;
200 	virtio_net_ctrl_ack status;
201 	struct virtio_net_ctrl_mq mq;
202 	u8 promisc;
203 	u8 allmulti;
204 	__virtio16 vid;
205 	__virtio64 offloads;
206 	struct virtio_net_ctrl_rss rss;
207 };
208 
209 struct virtnet_info {
210 	struct virtio_device *vdev;
211 	struct virtqueue *cvq;
212 	struct net_device *dev;
213 	struct send_queue *sq;
214 	struct receive_queue *rq;
215 	unsigned int status;
216 
217 	/* Max # of queue pairs supported by the device */
218 	u16 max_queue_pairs;
219 
220 	/* # of queue pairs currently used by the driver */
221 	u16 curr_queue_pairs;
222 
223 	/* # of XDP queue pairs currently used by the driver */
224 	u16 xdp_queue_pairs;
225 
226 	/* xdp_queue_pairs may be 0, when xdp is already loaded. So add this. */
227 	bool xdp_enabled;
228 
229 	/* I like... big packets and I cannot lie! */
230 	bool big_packets;
231 
232 	/* number of sg entries allocated for big packets */
233 	unsigned int big_packets_num_skbfrags;
234 
235 	/* Host will merge rx buffers for big packets (shake it! shake it!) */
236 	bool mergeable_rx_bufs;
237 
238 	/* Host supports rss and/or hash report */
239 	bool has_rss;
240 	bool has_rss_hash_report;
241 	u8 rss_key_size;
242 	u16 rss_indir_table_size;
243 	u32 rss_hash_types_supported;
244 	u32 rss_hash_types_saved;
245 
246 	/* Has control virtqueue */
247 	bool has_cvq;
248 
249 	/* Host can handle any s/g split between our header and packet data */
250 	bool any_header_sg;
251 
252 	/* Packet virtio header size */
253 	u8 hdr_len;
254 
255 	/* Work struct for delayed refilling if we run low on memory. */
256 	struct delayed_work refill;
257 
258 	/* Is delayed refill enabled? */
259 	bool refill_enabled;
260 
261 	/* The lock to synchronize the access to refill_enabled */
262 	spinlock_t refill_lock;
263 
264 	/* Work struct for config space updates */
265 	struct work_struct config_work;
266 
267 	/* Does the affinity hint is set for virtqueues? */
268 	bool affinity_hint_set;
269 
270 	/* CPU hotplug instances for online & dead */
271 	struct hlist_node node;
272 	struct hlist_node node_dead;
273 
274 	struct control_buf *ctrl;
275 
276 	/* Ethtool settings */
277 	u8 duplex;
278 	u32 speed;
279 
280 	/* Interrupt coalescing settings */
281 	u32 tx_usecs;
282 	u32 rx_usecs;
283 	u32 tx_max_packets;
284 	u32 rx_max_packets;
285 
286 	unsigned long guest_offloads;
287 	unsigned long guest_offloads_capable;
288 
289 	/* failover when STANDBY feature enabled */
290 	struct failover *failover;
291 };
292 
293 struct padded_vnet_hdr {
294 	struct virtio_net_hdr_v1_hash hdr;
295 	/*
296 	 * hdr is in a separate sg buffer, and data sg buffer shares same page
297 	 * with this header sg. This padding makes next sg 16 byte aligned
298 	 * after the header.
299 	 */
300 	char padding[12];
301 };
302 
303 static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
304 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
305 
306 static bool is_xdp_frame(void *ptr)
307 {
308 	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
309 }
310 
311 static void *xdp_to_ptr(struct xdp_frame *ptr)
312 {
313 	return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
314 }
315 
316 static struct xdp_frame *ptr_to_xdp(void *ptr)
317 {
318 	return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
319 }
320 
321 /* Converting between virtqueue no. and kernel tx/rx queue no.
322  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
323  */
324 static int vq2txq(struct virtqueue *vq)
325 {
326 	return (vq->index - 1) / 2;
327 }
328 
329 static int txq2vq(int txq)
330 {
331 	return txq * 2 + 1;
332 }
333 
334 static int vq2rxq(struct virtqueue *vq)
335 {
336 	return vq->index / 2;
337 }
338 
339 static int rxq2vq(int rxq)
340 {
341 	return rxq * 2;
342 }
343 
344 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
345 {
346 	return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
347 }
348 
349 /*
350  * private is used to chain pages for big packets, put the whole
351  * most recent used list in the beginning for reuse
352  */
353 static void give_pages(struct receive_queue *rq, struct page *page)
354 {
355 	struct page *end;
356 
357 	/* Find end of list, sew whole thing into vi->rq.pages. */
358 	for (end = page; end->private; end = (struct page *)end->private);
359 	end->private = (unsigned long)rq->pages;
360 	rq->pages = page;
361 }
362 
363 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
364 {
365 	struct page *p = rq->pages;
366 
367 	if (p) {
368 		rq->pages = (struct page *)p->private;
369 		/* clear private here, it is used to chain pages */
370 		p->private = 0;
371 	} else
372 		p = alloc_page(gfp_mask);
373 	return p;
374 }
375 
376 static void enable_delayed_refill(struct virtnet_info *vi)
377 {
378 	spin_lock_bh(&vi->refill_lock);
379 	vi->refill_enabled = true;
380 	spin_unlock_bh(&vi->refill_lock);
381 }
382 
383 static void disable_delayed_refill(struct virtnet_info *vi)
384 {
385 	spin_lock_bh(&vi->refill_lock);
386 	vi->refill_enabled = false;
387 	spin_unlock_bh(&vi->refill_lock);
388 }
389 
390 static void virtqueue_napi_schedule(struct napi_struct *napi,
391 				    struct virtqueue *vq)
392 {
393 	if (napi_schedule_prep(napi)) {
394 		virtqueue_disable_cb(vq);
395 		__napi_schedule(napi);
396 	}
397 }
398 
399 static void virtqueue_napi_complete(struct napi_struct *napi,
400 				    struct virtqueue *vq, int processed)
401 {
402 	int opaque;
403 
404 	opaque = virtqueue_enable_cb_prepare(vq);
405 	if (napi_complete_done(napi, processed)) {
406 		if (unlikely(virtqueue_poll(vq, opaque)))
407 			virtqueue_napi_schedule(napi, vq);
408 	} else {
409 		virtqueue_disable_cb(vq);
410 	}
411 }
412 
413 static void skb_xmit_done(struct virtqueue *vq)
414 {
415 	struct virtnet_info *vi = vq->vdev->priv;
416 	struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
417 
418 	/* Suppress further interrupts. */
419 	virtqueue_disable_cb(vq);
420 
421 	if (napi->weight)
422 		virtqueue_napi_schedule(napi, vq);
423 	else
424 		/* We were probably waiting for more output buffers. */
425 		netif_wake_subqueue(vi->dev, vq2txq(vq));
426 }
427 
428 #define MRG_CTX_HEADER_SHIFT 22
429 static void *mergeable_len_to_ctx(unsigned int truesize,
430 				  unsigned int headroom)
431 {
432 	return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
433 }
434 
435 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
436 {
437 	return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
438 }
439 
440 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
441 {
442 	return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
443 }
444 
445 /* Called from bottom half context */
446 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
447 				   struct receive_queue *rq,
448 				   struct page *page, unsigned int offset,
449 				   unsigned int len, unsigned int truesize,
450 				   unsigned int headroom)
451 {
452 	struct sk_buff *skb;
453 	struct virtio_net_hdr_mrg_rxbuf *hdr;
454 	unsigned int copy, hdr_len, hdr_padded_len;
455 	struct page *page_to_free = NULL;
456 	int tailroom, shinfo_size;
457 	char *p, *hdr_p, *buf;
458 
459 	p = page_address(page) + offset;
460 	hdr_p = p;
461 
462 	hdr_len = vi->hdr_len;
463 	if (vi->mergeable_rx_bufs)
464 		hdr_padded_len = hdr_len;
465 	else
466 		hdr_padded_len = sizeof(struct padded_vnet_hdr);
467 
468 	buf = p - headroom;
469 	len -= hdr_len;
470 	offset += hdr_padded_len;
471 	p += hdr_padded_len;
472 	tailroom = truesize - headroom  - hdr_padded_len - len;
473 
474 	shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
475 
476 	/* copy small packet so we can reuse these pages */
477 	if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) {
478 		skb = build_skb(buf, truesize);
479 		if (unlikely(!skb))
480 			return NULL;
481 
482 		skb_reserve(skb, p - buf);
483 		skb_put(skb, len);
484 
485 		page = (struct page *)page->private;
486 		if (page)
487 			give_pages(rq, page);
488 		goto ok;
489 	}
490 
491 	/* copy small packet so we can reuse these pages for small data */
492 	skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
493 	if (unlikely(!skb))
494 		return NULL;
495 
496 	/* Copy all frame if it fits skb->head, otherwise
497 	 * we let virtio_net_hdr_to_skb() and GRO pull headers as needed.
498 	 */
499 	if (len <= skb_tailroom(skb))
500 		copy = len;
501 	else
502 		copy = ETH_HLEN;
503 	skb_put_data(skb, p, copy);
504 
505 	len -= copy;
506 	offset += copy;
507 
508 	if (vi->mergeable_rx_bufs) {
509 		if (len)
510 			skb_add_rx_frag(skb, 0, page, offset, len, truesize);
511 		else
512 			page_to_free = page;
513 		goto ok;
514 	}
515 
516 	/*
517 	 * Verify that we can indeed put this data into a skb.
518 	 * This is here to handle cases when the device erroneously
519 	 * tries to receive more than is possible. This is usually
520 	 * the case of a broken device.
521 	 */
522 	if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
523 		net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
524 		dev_kfree_skb(skb);
525 		return NULL;
526 	}
527 	BUG_ON(offset >= PAGE_SIZE);
528 	while (len) {
529 		unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
530 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
531 				frag_size, truesize);
532 		len -= frag_size;
533 		page = (struct page *)page->private;
534 		offset = 0;
535 	}
536 
537 	if (page)
538 		give_pages(rq, page);
539 
540 ok:
541 	hdr = skb_vnet_hdr(skb);
542 	memcpy(hdr, hdr_p, hdr_len);
543 	if (page_to_free)
544 		put_page(page_to_free);
545 
546 	return skb;
547 }
548 
549 static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
550 {
551 	unsigned int len;
552 	unsigned int packets = 0;
553 	unsigned int bytes = 0;
554 	void *ptr;
555 
556 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
557 		if (likely(!is_xdp_frame(ptr))) {
558 			struct sk_buff *skb = ptr;
559 
560 			pr_debug("Sent skb %p\n", skb);
561 
562 			bytes += skb->len;
563 			napi_consume_skb(skb, in_napi);
564 		} else {
565 			struct xdp_frame *frame = ptr_to_xdp(ptr);
566 
567 			bytes += xdp_get_frame_len(frame);
568 			xdp_return_frame(frame);
569 		}
570 		packets++;
571 	}
572 
573 	/* Avoid overhead when no packets have been processed
574 	 * happens when called speculatively from start_xmit.
575 	 */
576 	if (!packets)
577 		return;
578 
579 	u64_stats_update_begin(&sq->stats.syncp);
580 	sq->stats.bytes += bytes;
581 	sq->stats.packets += packets;
582 	u64_stats_update_end(&sq->stats.syncp);
583 }
584 
585 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
586 {
587 	if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
588 		return false;
589 	else if (q < vi->curr_queue_pairs)
590 		return true;
591 	else
592 		return false;
593 }
594 
595 static void check_sq_full_and_disable(struct virtnet_info *vi,
596 				      struct net_device *dev,
597 				      struct send_queue *sq)
598 {
599 	bool use_napi = sq->napi.weight;
600 	int qnum;
601 
602 	qnum = sq - vi->sq;
603 
604 	/* If running out of space, stop queue to avoid getting packets that we
605 	 * are then unable to transmit.
606 	 * An alternative would be to force queuing layer to requeue the skb by
607 	 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
608 	 * returned in a normal path of operation: it means that driver is not
609 	 * maintaining the TX queue stop/start state properly, and causes
610 	 * the stack to do a non-trivial amount of useless work.
611 	 * Since most packets only take 1 or 2 ring slots, stopping the queue
612 	 * early means 16 slots are typically wasted.
613 	 */
614 	if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
615 		netif_stop_subqueue(dev, qnum);
616 		if (use_napi) {
617 			if (unlikely(!virtqueue_enable_cb_delayed(sq->vq)))
618 				virtqueue_napi_schedule(&sq->napi, sq->vq);
619 		} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
620 			/* More just got used, free them then recheck. */
621 			free_old_xmit_skbs(sq, false);
622 			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
623 				netif_start_subqueue(dev, qnum);
624 				virtqueue_disable_cb(sq->vq);
625 			}
626 		}
627 	}
628 }
629 
630 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
631 				   struct send_queue *sq,
632 				   struct xdp_frame *xdpf)
633 {
634 	struct virtio_net_hdr_mrg_rxbuf *hdr;
635 	struct skb_shared_info *shinfo;
636 	u8 nr_frags = 0;
637 	int err, i;
638 
639 	if (unlikely(xdpf->headroom < vi->hdr_len))
640 		return -EOVERFLOW;
641 
642 	if (unlikely(xdp_frame_has_frags(xdpf))) {
643 		shinfo = xdp_get_shared_info_from_frame(xdpf);
644 		nr_frags = shinfo->nr_frags;
645 	}
646 
647 	/* In wrapping function virtnet_xdp_xmit(), we need to free
648 	 * up the pending old buffers, where we need to calculate the
649 	 * position of skb_shared_info in xdp_get_frame_len() and
650 	 * xdp_return_frame(), which will involve to xdpf->data and
651 	 * xdpf->headroom. Therefore, we need to update the value of
652 	 * headroom synchronously here.
653 	 */
654 	xdpf->headroom -= vi->hdr_len;
655 	xdpf->data -= vi->hdr_len;
656 	/* Zero header and leave csum up to XDP layers */
657 	hdr = xdpf->data;
658 	memset(hdr, 0, vi->hdr_len);
659 	xdpf->len   += vi->hdr_len;
660 
661 	sg_init_table(sq->sg, nr_frags + 1);
662 	sg_set_buf(sq->sg, xdpf->data, xdpf->len);
663 	for (i = 0; i < nr_frags; i++) {
664 		skb_frag_t *frag = &shinfo->frags[i];
665 
666 		sg_set_page(&sq->sg[i + 1], skb_frag_page(frag),
667 			    skb_frag_size(frag), skb_frag_off(frag));
668 	}
669 
670 	err = virtqueue_add_outbuf(sq->vq, sq->sg, nr_frags + 1,
671 				   xdp_to_ptr(xdpf), GFP_ATOMIC);
672 	if (unlikely(err))
673 		return -ENOSPC; /* Caller handle free/refcnt */
674 
675 	return 0;
676 }
677 
678 /* when vi->curr_queue_pairs > nr_cpu_ids, the txq/sq is only used for xdp tx on
679  * the current cpu, so it does not need to be locked.
680  *
681  * Here we use marco instead of inline functions because we have to deal with
682  * three issues at the same time: 1. the choice of sq. 2. judge and execute the
683  * lock/unlock of txq 3. make sparse happy. It is difficult for two inline
684  * functions to perfectly solve these three problems at the same time.
685  */
686 #define virtnet_xdp_get_sq(vi) ({                                       \
687 	int cpu = smp_processor_id();                                   \
688 	struct netdev_queue *txq;                                       \
689 	typeof(vi) v = (vi);                                            \
690 	unsigned int qp;                                                \
691 									\
692 	if (v->curr_queue_pairs > nr_cpu_ids) {                         \
693 		qp = v->curr_queue_pairs - v->xdp_queue_pairs;          \
694 		qp += cpu;                                              \
695 		txq = netdev_get_tx_queue(v->dev, qp);                  \
696 		__netif_tx_acquire(txq);                                \
697 	} else {                                                        \
698 		qp = cpu % v->curr_queue_pairs;                         \
699 		txq = netdev_get_tx_queue(v->dev, qp);                  \
700 		__netif_tx_lock(txq, cpu);                              \
701 	}                                                               \
702 	v->sq + qp;                                                     \
703 })
704 
705 #define virtnet_xdp_put_sq(vi, q) {                                     \
706 	struct netdev_queue *txq;                                       \
707 	typeof(vi) v = (vi);                                            \
708 									\
709 	txq = netdev_get_tx_queue(v->dev, (q) - v->sq);                 \
710 	if (v->curr_queue_pairs > nr_cpu_ids)                           \
711 		__netif_tx_release(txq);                                \
712 	else                                                            \
713 		__netif_tx_unlock(txq);                                 \
714 }
715 
716 static int virtnet_xdp_xmit(struct net_device *dev,
717 			    int n, struct xdp_frame **frames, u32 flags)
718 {
719 	struct virtnet_info *vi = netdev_priv(dev);
720 	struct receive_queue *rq = vi->rq;
721 	struct bpf_prog *xdp_prog;
722 	struct send_queue *sq;
723 	unsigned int len;
724 	int packets = 0;
725 	int bytes = 0;
726 	int nxmit = 0;
727 	int kicks = 0;
728 	void *ptr;
729 	int ret;
730 	int i;
731 
732 	/* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
733 	 * indicate XDP resources have been successfully allocated.
734 	 */
735 	xdp_prog = rcu_access_pointer(rq->xdp_prog);
736 	if (!xdp_prog)
737 		return -ENXIO;
738 
739 	sq = virtnet_xdp_get_sq(vi);
740 
741 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
742 		ret = -EINVAL;
743 		goto out;
744 	}
745 
746 	/* Free up any pending old buffers before queueing new ones. */
747 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
748 		if (likely(is_xdp_frame(ptr))) {
749 			struct xdp_frame *frame = ptr_to_xdp(ptr);
750 
751 			bytes += xdp_get_frame_len(frame);
752 			xdp_return_frame(frame);
753 		} else {
754 			struct sk_buff *skb = ptr;
755 
756 			bytes += skb->len;
757 			napi_consume_skb(skb, false);
758 		}
759 		packets++;
760 	}
761 
762 	for (i = 0; i < n; i++) {
763 		struct xdp_frame *xdpf = frames[i];
764 
765 		if (__virtnet_xdp_xmit_one(vi, sq, xdpf))
766 			break;
767 		nxmit++;
768 	}
769 	ret = nxmit;
770 
771 	if (!is_xdp_raw_buffer_queue(vi, sq - vi->sq))
772 		check_sq_full_and_disable(vi, dev, sq);
773 
774 	if (flags & XDP_XMIT_FLUSH) {
775 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
776 			kicks = 1;
777 	}
778 out:
779 	u64_stats_update_begin(&sq->stats.syncp);
780 	sq->stats.bytes += bytes;
781 	sq->stats.packets += packets;
782 	sq->stats.xdp_tx += n;
783 	sq->stats.xdp_tx_drops += n - nxmit;
784 	sq->stats.kicks += kicks;
785 	u64_stats_update_end(&sq->stats.syncp);
786 
787 	virtnet_xdp_put_sq(vi, sq);
788 	return ret;
789 }
790 
791 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
792 {
793 	return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0;
794 }
795 
796 /* We copy the packet for XDP in the following cases:
797  *
798  * 1) Packet is scattered across multiple rx buffers.
799  * 2) Headroom space is insufficient.
800  *
801  * This is inefficient but it's a temporary condition that
802  * we hit right after XDP is enabled and until queue is refilled
803  * with large buffers with sufficient headroom - so it should affect
804  * at most queue size packets.
805  * Afterwards, the conditions to enable
806  * XDP should preclude the underlying device from sending packets
807  * across multiple buffers (num_buf > 1), and we make sure buffers
808  * have enough headroom.
809  */
810 static struct page *xdp_linearize_page(struct receive_queue *rq,
811 				       int *num_buf,
812 				       struct page *p,
813 				       int offset,
814 				       int page_off,
815 				       unsigned int *len)
816 {
817 	int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
818 	struct page *page;
819 
820 	if (page_off + *len + tailroom > PAGE_SIZE)
821 		return NULL;
822 
823 	page = alloc_page(GFP_ATOMIC);
824 	if (!page)
825 		return NULL;
826 
827 	memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
828 	page_off += *len;
829 
830 	while (--*num_buf) {
831 		unsigned int buflen;
832 		void *buf;
833 		int off;
834 
835 		buf = virtqueue_get_buf(rq->vq, &buflen);
836 		if (unlikely(!buf))
837 			goto err_buf;
838 
839 		p = virt_to_head_page(buf);
840 		off = buf - page_address(p);
841 
842 		/* guard against a misconfigured or uncooperative backend that
843 		 * is sending packet larger than the MTU.
844 		 */
845 		if ((page_off + buflen + tailroom) > PAGE_SIZE) {
846 			put_page(p);
847 			goto err_buf;
848 		}
849 
850 		memcpy(page_address(page) + page_off,
851 		       page_address(p) + off, buflen);
852 		page_off += buflen;
853 		put_page(p);
854 	}
855 
856 	/* Headroom does not contribute to packet length */
857 	*len = page_off - VIRTIO_XDP_HEADROOM;
858 	return page;
859 err_buf:
860 	__free_pages(page, 0);
861 	return NULL;
862 }
863 
864 static struct sk_buff *receive_small(struct net_device *dev,
865 				     struct virtnet_info *vi,
866 				     struct receive_queue *rq,
867 				     void *buf, void *ctx,
868 				     unsigned int len,
869 				     unsigned int *xdp_xmit,
870 				     struct virtnet_rq_stats *stats)
871 {
872 	struct sk_buff *skb;
873 	struct bpf_prog *xdp_prog;
874 	unsigned int xdp_headroom = (unsigned long)ctx;
875 	unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
876 	unsigned int headroom = vi->hdr_len + header_offset;
877 	unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
878 			      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
879 	struct page *page = virt_to_head_page(buf);
880 	unsigned int delta = 0;
881 	struct page *xdp_page;
882 	int err;
883 	unsigned int metasize = 0;
884 
885 	len -= vi->hdr_len;
886 	stats->bytes += len;
887 
888 	if (unlikely(len > GOOD_PACKET_LEN)) {
889 		pr_debug("%s: rx error: len %u exceeds max size %d\n",
890 			 dev->name, len, GOOD_PACKET_LEN);
891 		dev->stats.rx_length_errors++;
892 		goto err;
893 	}
894 
895 	if (likely(!vi->xdp_enabled)) {
896 		xdp_prog = NULL;
897 		goto skip_xdp;
898 	}
899 
900 	rcu_read_lock();
901 	xdp_prog = rcu_dereference(rq->xdp_prog);
902 	if (xdp_prog) {
903 		struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
904 		struct xdp_frame *xdpf;
905 		struct xdp_buff xdp;
906 		void *orig_data;
907 		u32 act;
908 
909 		if (unlikely(hdr->hdr.gso_type))
910 			goto err_xdp;
911 
912 		if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
913 			int offset = buf - page_address(page) + header_offset;
914 			unsigned int tlen = len + vi->hdr_len;
915 			int num_buf = 1;
916 
917 			xdp_headroom = virtnet_get_headroom(vi);
918 			header_offset = VIRTNET_RX_PAD + xdp_headroom;
919 			headroom = vi->hdr_len + header_offset;
920 			buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
921 				 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
922 			xdp_page = xdp_linearize_page(rq, &num_buf, page,
923 						      offset, header_offset,
924 						      &tlen);
925 			if (!xdp_page)
926 				goto err_xdp;
927 
928 			buf = page_address(xdp_page);
929 			put_page(page);
930 			page = xdp_page;
931 		}
932 
933 		xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
934 		xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
935 				 xdp_headroom, len, true);
936 		orig_data = xdp.data;
937 		act = bpf_prog_run_xdp(xdp_prog, &xdp);
938 		stats->xdp_packets++;
939 
940 		switch (act) {
941 		case XDP_PASS:
942 			/* Recalculate length in case bpf program changed it */
943 			delta = orig_data - xdp.data;
944 			len = xdp.data_end - xdp.data;
945 			metasize = xdp.data - xdp.data_meta;
946 			break;
947 		case XDP_TX:
948 			stats->xdp_tx++;
949 			xdpf = xdp_convert_buff_to_frame(&xdp);
950 			if (unlikely(!xdpf))
951 				goto err_xdp;
952 			err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
953 			if (unlikely(!err)) {
954 				xdp_return_frame_rx_napi(xdpf);
955 			} else if (unlikely(err < 0)) {
956 				trace_xdp_exception(vi->dev, xdp_prog, act);
957 				goto err_xdp;
958 			}
959 			*xdp_xmit |= VIRTIO_XDP_TX;
960 			rcu_read_unlock();
961 			goto xdp_xmit;
962 		case XDP_REDIRECT:
963 			stats->xdp_redirects++;
964 			err = xdp_do_redirect(dev, &xdp, xdp_prog);
965 			if (err)
966 				goto err_xdp;
967 			*xdp_xmit |= VIRTIO_XDP_REDIR;
968 			rcu_read_unlock();
969 			goto xdp_xmit;
970 		default:
971 			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
972 			fallthrough;
973 		case XDP_ABORTED:
974 			trace_xdp_exception(vi->dev, xdp_prog, act);
975 			goto err_xdp;
976 		case XDP_DROP:
977 			goto err_xdp;
978 		}
979 	}
980 	rcu_read_unlock();
981 
982 skip_xdp:
983 	skb = build_skb(buf, buflen);
984 	if (!skb)
985 		goto err;
986 	skb_reserve(skb, headroom - delta);
987 	skb_put(skb, len);
988 	if (!xdp_prog) {
989 		buf += header_offset;
990 		memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
991 	} /* keep zeroed vnet hdr since XDP is loaded */
992 
993 	if (metasize)
994 		skb_metadata_set(skb, metasize);
995 
996 	return skb;
997 
998 err_xdp:
999 	rcu_read_unlock();
1000 	stats->xdp_drops++;
1001 err:
1002 	stats->drops++;
1003 	put_page(page);
1004 xdp_xmit:
1005 	return NULL;
1006 }
1007 
1008 static struct sk_buff *receive_big(struct net_device *dev,
1009 				   struct virtnet_info *vi,
1010 				   struct receive_queue *rq,
1011 				   void *buf,
1012 				   unsigned int len,
1013 				   struct virtnet_rq_stats *stats)
1014 {
1015 	struct page *page = buf;
1016 	struct sk_buff *skb =
1017 		page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, 0);
1018 
1019 	stats->bytes += len - vi->hdr_len;
1020 	if (unlikely(!skb))
1021 		goto err;
1022 
1023 	return skb;
1024 
1025 err:
1026 	stats->drops++;
1027 	give_pages(rq, page);
1028 	return NULL;
1029 }
1030 
1031 /* Why not use xdp_build_skb_from_frame() ?
1032  * XDP core assumes that xdp frags are PAGE_SIZE in length, while in
1033  * virtio-net there are 2 points that do not match its requirements:
1034  *  1. The size of the prefilled buffer is not fixed before xdp is set.
1035  *  2. xdp_build_skb_from_frame() does more checks that we don't need,
1036  *     like eth_type_trans() (which virtio-net does in receive_buf()).
1037  */
1038 static struct sk_buff *build_skb_from_xdp_buff(struct net_device *dev,
1039 					       struct virtnet_info *vi,
1040 					       struct xdp_buff *xdp,
1041 					       unsigned int xdp_frags_truesz)
1042 {
1043 	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
1044 	unsigned int headroom, data_len;
1045 	struct sk_buff *skb;
1046 	int metasize;
1047 	u8 nr_frags;
1048 
1049 	if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) {
1050 		pr_debug("Error building skb as missing reserved tailroom for xdp");
1051 		return NULL;
1052 	}
1053 
1054 	if (unlikely(xdp_buff_has_frags(xdp)))
1055 		nr_frags = sinfo->nr_frags;
1056 
1057 	skb = build_skb(xdp->data_hard_start, xdp->frame_sz);
1058 	if (unlikely(!skb))
1059 		return NULL;
1060 
1061 	headroom = xdp->data - xdp->data_hard_start;
1062 	data_len = xdp->data_end - xdp->data;
1063 	skb_reserve(skb, headroom);
1064 	__skb_put(skb, data_len);
1065 
1066 	metasize = xdp->data - xdp->data_meta;
1067 	metasize = metasize > 0 ? metasize : 0;
1068 	if (metasize)
1069 		skb_metadata_set(skb, metasize);
1070 
1071 	if (unlikely(xdp_buff_has_frags(xdp)))
1072 		xdp_update_skb_shared_info(skb, nr_frags,
1073 					   sinfo->xdp_frags_size,
1074 					   xdp_frags_truesz,
1075 					   xdp_buff_is_frag_pfmemalloc(xdp));
1076 
1077 	return skb;
1078 }
1079 
1080 /* TODO: build xdp in big mode */
1081 static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
1082 				      struct virtnet_info *vi,
1083 				      struct receive_queue *rq,
1084 				      struct xdp_buff *xdp,
1085 				      void *buf,
1086 				      unsigned int len,
1087 				      unsigned int frame_sz,
1088 				      int *num_buf,
1089 				      unsigned int *xdp_frags_truesize,
1090 				      struct virtnet_rq_stats *stats)
1091 {
1092 	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
1093 	unsigned int headroom, tailroom, room;
1094 	unsigned int truesize, cur_frag_size;
1095 	struct skb_shared_info *shinfo;
1096 	unsigned int xdp_frags_truesz = 0;
1097 	struct page *page;
1098 	skb_frag_t *frag;
1099 	int offset;
1100 	void *ctx;
1101 
1102 	xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
1103 	xdp_prepare_buff(xdp, buf - VIRTIO_XDP_HEADROOM,
1104 			 VIRTIO_XDP_HEADROOM + vi->hdr_len, len - vi->hdr_len, true);
1105 
1106 	if (!*num_buf)
1107 		return 0;
1108 
1109 	if (*num_buf > 1) {
1110 		/* If we want to build multi-buffer xdp, we need
1111 		 * to specify that the flags of xdp_buff have the
1112 		 * XDP_FLAGS_HAS_FRAG bit.
1113 		 */
1114 		if (!xdp_buff_has_frags(xdp))
1115 			xdp_buff_set_frags_flag(xdp);
1116 
1117 		shinfo = xdp_get_shared_info_from_buff(xdp);
1118 		shinfo->nr_frags = 0;
1119 		shinfo->xdp_frags_size = 0;
1120 	}
1121 
1122 	if (*num_buf > MAX_SKB_FRAGS + 1)
1123 		return -EINVAL;
1124 
1125 	while (--*num_buf > 0) {
1126 		buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1127 		if (unlikely(!buf)) {
1128 			pr_debug("%s: rx error: %d buffers out of %d missing\n",
1129 				 dev->name, *num_buf,
1130 				 virtio16_to_cpu(vi->vdev, hdr->num_buffers));
1131 			dev->stats.rx_length_errors++;
1132 			return -EINVAL;
1133 		}
1134 
1135 		stats->bytes += len;
1136 		page = virt_to_head_page(buf);
1137 		offset = buf - page_address(page);
1138 
1139 		truesize = mergeable_ctx_to_truesize(ctx);
1140 		headroom = mergeable_ctx_to_headroom(ctx);
1141 		tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1142 		room = SKB_DATA_ALIGN(headroom + tailroom);
1143 
1144 		cur_frag_size = truesize;
1145 		xdp_frags_truesz += cur_frag_size;
1146 		if (unlikely(len > truesize - room || cur_frag_size > PAGE_SIZE)) {
1147 			put_page(page);
1148 			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1149 				 dev->name, len, (unsigned long)(truesize - room));
1150 			dev->stats.rx_length_errors++;
1151 			return -EINVAL;
1152 		}
1153 
1154 		frag = &shinfo->frags[shinfo->nr_frags++];
1155 		__skb_frag_set_page(frag, page);
1156 		skb_frag_off_set(frag, offset);
1157 		skb_frag_size_set(frag, len);
1158 		if (page_is_pfmemalloc(page))
1159 			xdp_buff_set_frag_pfmemalloc(xdp);
1160 
1161 		shinfo->xdp_frags_size += len;
1162 	}
1163 
1164 	*xdp_frags_truesize = xdp_frags_truesz;
1165 	return 0;
1166 }
1167 
1168 static struct sk_buff *receive_mergeable(struct net_device *dev,
1169 					 struct virtnet_info *vi,
1170 					 struct receive_queue *rq,
1171 					 void *buf,
1172 					 void *ctx,
1173 					 unsigned int len,
1174 					 unsigned int *xdp_xmit,
1175 					 struct virtnet_rq_stats *stats)
1176 {
1177 	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
1178 	int num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
1179 	struct page *page = virt_to_head_page(buf);
1180 	int offset = buf - page_address(page);
1181 	struct sk_buff *head_skb, *curr_skb;
1182 	struct bpf_prog *xdp_prog;
1183 	unsigned int truesize = mergeable_ctx_to_truesize(ctx);
1184 	unsigned int headroom = mergeable_ctx_to_headroom(ctx);
1185 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1186 	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1187 	unsigned int frame_sz, xdp_room;
1188 	int err;
1189 
1190 	head_skb = NULL;
1191 	stats->bytes += len - vi->hdr_len;
1192 
1193 	if (unlikely(len > truesize - room)) {
1194 		pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1195 			 dev->name, len, (unsigned long)(truesize - room));
1196 		dev->stats.rx_length_errors++;
1197 		goto err_skb;
1198 	}
1199 
1200 	if (likely(!vi->xdp_enabled)) {
1201 		xdp_prog = NULL;
1202 		goto skip_xdp;
1203 	}
1204 
1205 	rcu_read_lock();
1206 	xdp_prog = rcu_dereference(rq->xdp_prog);
1207 	if (xdp_prog) {
1208 		unsigned int xdp_frags_truesz = 0;
1209 		struct skb_shared_info *shinfo;
1210 		struct xdp_frame *xdpf;
1211 		struct page *xdp_page;
1212 		struct xdp_buff xdp;
1213 		void *data;
1214 		u32 act;
1215 		int i;
1216 
1217 		/* Transient failure which in theory could occur if
1218 		 * in-flight packets from before XDP was enabled reach
1219 		 * the receive path after XDP is loaded.
1220 		 */
1221 		if (unlikely(hdr->hdr.gso_type))
1222 			goto err_xdp;
1223 
1224 		/* Now XDP core assumes frag size is PAGE_SIZE, but buffers
1225 		 * with headroom may add hole in truesize, which
1226 		 * make their length exceed PAGE_SIZE. So we disabled the
1227 		 * hole mechanism for xdp. See add_recvbuf_mergeable().
1228 		 */
1229 		frame_sz = truesize;
1230 
1231 		/* This happens when headroom is not enough because
1232 		 * of the buffer was prefilled before XDP is set.
1233 		 * This should only happen for the first several packets.
1234 		 * In fact, vq reset can be used here to help us clean up
1235 		 * the prefilled buffers, but many existing devices do not
1236 		 * support it, and we don't want to bother users who are
1237 		 * using xdp normally.
1238 		 */
1239 		if (!xdp_prog->aux->xdp_has_frags &&
1240 		    (num_buf > 1 || headroom < virtnet_get_headroom(vi))) {
1241 			/* linearize data for XDP */
1242 			xdp_page = xdp_linearize_page(rq, &num_buf,
1243 						      page, offset,
1244 						      VIRTIO_XDP_HEADROOM,
1245 						      &len);
1246 			frame_sz = PAGE_SIZE;
1247 
1248 			if (!xdp_page)
1249 				goto err_xdp;
1250 			offset = VIRTIO_XDP_HEADROOM;
1251 		} else if (unlikely(headroom < virtnet_get_headroom(vi))) {
1252 			xdp_room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM +
1253 						  sizeof(struct skb_shared_info));
1254 			if (len + xdp_room > PAGE_SIZE)
1255 				goto err_xdp;
1256 
1257 			xdp_page = alloc_page(GFP_ATOMIC);
1258 			if (!xdp_page)
1259 				goto err_xdp;
1260 
1261 			memcpy(page_address(xdp_page) + VIRTIO_XDP_HEADROOM,
1262 			       page_address(page) + offset, len);
1263 			frame_sz = PAGE_SIZE;
1264 			offset = VIRTIO_XDP_HEADROOM;
1265 		} else {
1266 			xdp_page = page;
1267 		}
1268 
1269 		data = page_address(xdp_page) + offset;
1270 		err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz,
1271 						 &num_buf, &xdp_frags_truesz, stats);
1272 		if (unlikely(err))
1273 			goto err_xdp_frags;
1274 
1275 		act = bpf_prog_run_xdp(xdp_prog, &xdp);
1276 		stats->xdp_packets++;
1277 
1278 		switch (act) {
1279 		case XDP_PASS:
1280 			head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
1281 			if (unlikely(!head_skb))
1282 				goto err_xdp_frags;
1283 
1284 			if (unlikely(xdp_page != page))
1285 				put_page(page);
1286 			rcu_read_unlock();
1287 			return head_skb;
1288 		case XDP_TX:
1289 			stats->xdp_tx++;
1290 			xdpf = xdp_convert_buff_to_frame(&xdp);
1291 			if (unlikely(!xdpf)) {
1292 				netdev_dbg(dev, "convert buff to frame failed for xdp\n");
1293 				goto err_xdp_frags;
1294 			}
1295 			err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
1296 			if (unlikely(!err)) {
1297 				xdp_return_frame_rx_napi(xdpf);
1298 			} else if (unlikely(err < 0)) {
1299 				trace_xdp_exception(vi->dev, xdp_prog, act);
1300 				goto err_xdp_frags;
1301 			}
1302 			*xdp_xmit |= VIRTIO_XDP_TX;
1303 			if (unlikely(xdp_page != page))
1304 				put_page(page);
1305 			rcu_read_unlock();
1306 			goto xdp_xmit;
1307 		case XDP_REDIRECT:
1308 			stats->xdp_redirects++;
1309 			err = xdp_do_redirect(dev, &xdp, xdp_prog);
1310 			if (err)
1311 				goto err_xdp_frags;
1312 			*xdp_xmit |= VIRTIO_XDP_REDIR;
1313 			if (unlikely(xdp_page != page))
1314 				put_page(page);
1315 			rcu_read_unlock();
1316 			goto xdp_xmit;
1317 		default:
1318 			bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
1319 			fallthrough;
1320 		case XDP_ABORTED:
1321 			trace_xdp_exception(vi->dev, xdp_prog, act);
1322 			fallthrough;
1323 		case XDP_DROP:
1324 			goto err_xdp_frags;
1325 		}
1326 err_xdp_frags:
1327 		if (unlikely(xdp_page != page))
1328 			__free_pages(xdp_page, 0);
1329 
1330 		if (xdp_buff_has_frags(&xdp)) {
1331 			shinfo = xdp_get_shared_info_from_buff(&xdp);
1332 			for (i = 0; i < shinfo->nr_frags; i++) {
1333 				xdp_page = skb_frag_page(&shinfo->frags[i]);
1334 				put_page(xdp_page);
1335 			}
1336 		}
1337 
1338 		goto err_xdp;
1339 	}
1340 	rcu_read_unlock();
1341 
1342 skip_xdp:
1343 	head_skb = page_to_skb(vi, rq, page, offset, len, truesize, headroom);
1344 	curr_skb = head_skb;
1345 
1346 	if (unlikely(!curr_skb))
1347 		goto err_skb;
1348 	while (--num_buf) {
1349 		int num_skb_frags;
1350 
1351 		buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1352 		if (unlikely(!buf)) {
1353 			pr_debug("%s: rx error: %d buffers out of %d missing\n",
1354 				 dev->name, num_buf,
1355 				 virtio16_to_cpu(vi->vdev,
1356 						 hdr->num_buffers));
1357 			dev->stats.rx_length_errors++;
1358 			goto err_buf;
1359 		}
1360 
1361 		stats->bytes += len;
1362 		page = virt_to_head_page(buf);
1363 
1364 		truesize = mergeable_ctx_to_truesize(ctx);
1365 		headroom = mergeable_ctx_to_headroom(ctx);
1366 		tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1367 		room = SKB_DATA_ALIGN(headroom + tailroom);
1368 		if (unlikely(len > truesize - room)) {
1369 			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1370 				 dev->name, len, (unsigned long)(truesize - room));
1371 			dev->stats.rx_length_errors++;
1372 			goto err_skb;
1373 		}
1374 
1375 		num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
1376 		if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
1377 			struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
1378 
1379 			if (unlikely(!nskb))
1380 				goto err_skb;
1381 			if (curr_skb == head_skb)
1382 				skb_shinfo(curr_skb)->frag_list = nskb;
1383 			else
1384 				curr_skb->next = nskb;
1385 			curr_skb = nskb;
1386 			head_skb->truesize += nskb->truesize;
1387 			num_skb_frags = 0;
1388 		}
1389 		if (curr_skb != head_skb) {
1390 			head_skb->data_len += len;
1391 			head_skb->len += len;
1392 			head_skb->truesize += truesize;
1393 		}
1394 		offset = buf - page_address(page);
1395 		if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
1396 			put_page(page);
1397 			skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
1398 					     len, truesize);
1399 		} else {
1400 			skb_add_rx_frag(curr_skb, num_skb_frags, page,
1401 					offset, len, truesize);
1402 		}
1403 	}
1404 
1405 	ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
1406 	return head_skb;
1407 
1408 err_xdp:
1409 	rcu_read_unlock();
1410 	stats->xdp_drops++;
1411 err_skb:
1412 	put_page(page);
1413 	while (num_buf-- > 1) {
1414 		buf = virtqueue_get_buf(rq->vq, &len);
1415 		if (unlikely(!buf)) {
1416 			pr_debug("%s: rx error: %d buffers missing\n",
1417 				 dev->name, num_buf);
1418 			dev->stats.rx_length_errors++;
1419 			break;
1420 		}
1421 		stats->bytes += len;
1422 		page = virt_to_head_page(buf);
1423 		put_page(page);
1424 	}
1425 err_buf:
1426 	stats->drops++;
1427 	dev_kfree_skb(head_skb);
1428 xdp_xmit:
1429 	return NULL;
1430 }
1431 
1432 static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
1433 				struct sk_buff *skb)
1434 {
1435 	enum pkt_hash_types rss_hash_type;
1436 
1437 	if (!hdr_hash || !skb)
1438 		return;
1439 
1440 	switch (__le16_to_cpu(hdr_hash->hash_report)) {
1441 	case VIRTIO_NET_HASH_REPORT_TCPv4:
1442 	case VIRTIO_NET_HASH_REPORT_UDPv4:
1443 	case VIRTIO_NET_HASH_REPORT_TCPv6:
1444 	case VIRTIO_NET_HASH_REPORT_UDPv6:
1445 	case VIRTIO_NET_HASH_REPORT_TCPv6_EX:
1446 	case VIRTIO_NET_HASH_REPORT_UDPv6_EX:
1447 		rss_hash_type = PKT_HASH_TYPE_L4;
1448 		break;
1449 	case VIRTIO_NET_HASH_REPORT_IPv4:
1450 	case VIRTIO_NET_HASH_REPORT_IPv6:
1451 	case VIRTIO_NET_HASH_REPORT_IPv6_EX:
1452 		rss_hash_type = PKT_HASH_TYPE_L3;
1453 		break;
1454 	case VIRTIO_NET_HASH_REPORT_NONE:
1455 	default:
1456 		rss_hash_type = PKT_HASH_TYPE_NONE;
1457 	}
1458 	skb_set_hash(skb, __le32_to_cpu(hdr_hash->hash_value), rss_hash_type);
1459 }
1460 
1461 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1462 			void *buf, unsigned int len, void **ctx,
1463 			unsigned int *xdp_xmit,
1464 			struct virtnet_rq_stats *stats)
1465 {
1466 	struct net_device *dev = vi->dev;
1467 	struct sk_buff *skb;
1468 	struct virtio_net_hdr_mrg_rxbuf *hdr;
1469 
1470 	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1471 		pr_debug("%s: short packet %i\n", dev->name, len);
1472 		dev->stats.rx_length_errors++;
1473 		virtnet_rq_free_unused_buf(rq->vq, buf);
1474 		return;
1475 	}
1476 
1477 	if (vi->mergeable_rx_bufs)
1478 		skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1479 					stats);
1480 	else if (vi->big_packets)
1481 		skb = receive_big(dev, vi, rq, buf, len, stats);
1482 	else
1483 		skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1484 
1485 	if (unlikely(!skb))
1486 		return;
1487 
1488 	hdr = skb_vnet_hdr(skb);
1489 	if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
1490 		virtio_skb_set_hash((const struct virtio_net_hdr_v1_hash *)hdr, skb);
1491 
1492 	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1493 		skb->ip_summed = CHECKSUM_UNNECESSARY;
1494 
1495 	if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1496 				  virtio_is_little_endian(vi->vdev))) {
1497 		net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1498 				     dev->name, hdr->hdr.gso_type,
1499 				     hdr->hdr.gso_size);
1500 		goto frame_err;
1501 	}
1502 
1503 	skb_record_rx_queue(skb, vq2rxq(rq->vq));
1504 	skb->protocol = eth_type_trans(skb, dev);
1505 	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1506 		 ntohs(skb->protocol), skb->len, skb->pkt_type);
1507 
1508 	napi_gro_receive(&rq->napi, skb);
1509 	return;
1510 
1511 frame_err:
1512 	dev->stats.rx_frame_errors++;
1513 	dev_kfree_skb(skb);
1514 }
1515 
1516 /* Unlike mergeable buffers, all buffers are allocated to the
1517  * same size, except for the headroom. For this reason we do
1518  * not need to use  mergeable_len_to_ctx here - it is enough
1519  * to store the headroom as the context ignoring the truesize.
1520  */
1521 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1522 			     gfp_t gfp)
1523 {
1524 	struct page_frag *alloc_frag = &rq->alloc_frag;
1525 	char *buf;
1526 	unsigned int xdp_headroom = virtnet_get_headroom(vi);
1527 	void *ctx = (void *)(unsigned long)xdp_headroom;
1528 	int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1529 	int err;
1530 
1531 	len = SKB_DATA_ALIGN(len) +
1532 	      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1533 	if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1534 		return -ENOMEM;
1535 
1536 	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1537 	get_page(alloc_frag->page);
1538 	alloc_frag->offset += len;
1539 	sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1540 		    vi->hdr_len + GOOD_PACKET_LEN);
1541 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1542 	if (err < 0)
1543 		put_page(virt_to_head_page(buf));
1544 	return err;
1545 }
1546 
1547 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1548 			   gfp_t gfp)
1549 {
1550 	struct page *first, *list = NULL;
1551 	char *p;
1552 	int i, err, offset;
1553 
1554 	sg_init_table(rq->sg, vi->big_packets_num_skbfrags + 2);
1555 
1556 	/* page in rq->sg[vi->big_packets_num_skbfrags + 1] is list tail */
1557 	for (i = vi->big_packets_num_skbfrags + 1; i > 1; --i) {
1558 		first = get_a_page(rq, gfp);
1559 		if (!first) {
1560 			if (list)
1561 				give_pages(rq, list);
1562 			return -ENOMEM;
1563 		}
1564 		sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1565 
1566 		/* chain new page in list head to match sg */
1567 		first->private = (unsigned long)list;
1568 		list = first;
1569 	}
1570 
1571 	first = get_a_page(rq, gfp);
1572 	if (!first) {
1573 		give_pages(rq, list);
1574 		return -ENOMEM;
1575 	}
1576 	p = page_address(first);
1577 
1578 	/* rq->sg[0], rq->sg[1] share the same page */
1579 	/* a separated rq->sg[0] for header - required in case !any_header_sg */
1580 	sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1581 
1582 	/* rq->sg[1] for data packet, from offset */
1583 	offset = sizeof(struct padded_vnet_hdr);
1584 	sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1585 
1586 	/* chain first in list head */
1587 	first->private = (unsigned long)list;
1588 	err = virtqueue_add_inbuf(rq->vq, rq->sg, vi->big_packets_num_skbfrags + 2,
1589 				  first, gfp);
1590 	if (err < 0)
1591 		give_pages(rq, first);
1592 
1593 	return err;
1594 }
1595 
1596 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1597 					  struct ewma_pkt_len *avg_pkt_len,
1598 					  unsigned int room)
1599 {
1600 	struct virtnet_info *vi = rq->vq->vdev->priv;
1601 	const size_t hdr_len = vi->hdr_len;
1602 	unsigned int len;
1603 
1604 	if (room)
1605 		return PAGE_SIZE - room;
1606 
1607 	len = hdr_len +	clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1608 				rq->min_buf_len, PAGE_SIZE - hdr_len);
1609 
1610 	return ALIGN(len, L1_CACHE_BYTES);
1611 }
1612 
1613 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1614 				 struct receive_queue *rq, gfp_t gfp)
1615 {
1616 	struct page_frag *alloc_frag = &rq->alloc_frag;
1617 	unsigned int headroom = virtnet_get_headroom(vi);
1618 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1619 	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1620 	char *buf;
1621 	void *ctx;
1622 	int err;
1623 	unsigned int len, hole;
1624 
1625 	/* Extra tailroom is needed to satisfy XDP's assumption. This
1626 	 * means rx frags coalescing won't work, but consider we've
1627 	 * disabled GSO for XDP, it won't be a big issue.
1628 	 */
1629 	len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1630 	if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1631 		return -ENOMEM;
1632 
1633 	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1634 	buf += headroom; /* advance address leaving hole at front of pkt */
1635 	get_page(alloc_frag->page);
1636 	alloc_frag->offset += len + room;
1637 	hole = alloc_frag->size - alloc_frag->offset;
1638 	if (hole < len + room) {
1639 		/* To avoid internal fragmentation, if there is very likely not
1640 		 * enough space for another buffer, add the remaining space to
1641 		 * the current buffer.
1642 		 * XDP core assumes that frame_size of xdp_buff and the length
1643 		 * of the frag are PAGE_SIZE, so we disable the hole mechanism.
1644 		 */
1645 		if (!headroom)
1646 			len += hole;
1647 		alloc_frag->offset += hole;
1648 	}
1649 
1650 	sg_init_one(rq->sg, buf, len);
1651 	ctx = mergeable_len_to_ctx(len + room, headroom);
1652 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1653 	if (err < 0)
1654 		put_page(virt_to_head_page(buf));
1655 
1656 	return err;
1657 }
1658 
1659 /*
1660  * Returns false if we couldn't fill entirely (OOM).
1661  *
1662  * Normally run in the receive path, but can also be run from ndo_open
1663  * before we're receiving packets, or from refill_work which is
1664  * careful to disable receiving (using napi_disable).
1665  */
1666 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1667 			  gfp_t gfp)
1668 {
1669 	int err;
1670 	bool oom;
1671 
1672 	do {
1673 		if (vi->mergeable_rx_bufs)
1674 			err = add_recvbuf_mergeable(vi, rq, gfp);
1675 		else if (vi->big_packets)
1676 			err = add_recvbuf_big(vi, rq, gfp);
1677 		else
1678 			err = add_recvbuf_small(vi, rq, gfp);
1679 
1680 		oom = err == -ENOMEM;
1681 		if (err)
1682 			break;
1683 	} while (rq->vq->num_free);
1684 	if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1685 		unsigned long flags;
1686 
1687 		flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
1688 		rq->stats.kicks++;
1689 		u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
1690 	}
1691 
1692 	return !oom;
1693 }
1694 
1695 static void skb_recv_done(struct virtqueue *rvq)
1696 {
1697 	struct virtnet_info *vi = rvq->vdev->priv;
1698 	struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1699 
1700 	virtqueue_napi_schedule(&rq->napi, rvq);
1701 }
1702 
1703 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1704 {
1705 	napi_enable(napi);
1706 
1707 	/* If all buffers were filled by other side before we napi_enabled, we
1708 	 * won't get another interrupt, so process any outstanding packets now.
1709 	 * Call local_bh_enable after to trigger softIRQ processing.
1710 	 */
1711 	local_bh_disable();
1712 	virtqueue_napi_schedule(napi, vq);
1713 	local_bh_enable();
1714 }
1715 
1716 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1717 				   struct virtqueue *vq,
1718 				   struct napi_struct *napi)
1719 {
1720 	if (!napi->weight)
1721 		return;
1722 
1723 	/* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1724 	 * enable the feature if this is likely affine with the transmit path.
1725 	 */
1726 	if (!vi->affinity_hint_set) {
1727 		napi->weight = 0;
1728 		return;
1729 	}
1730 
1731 	return virtnet_napi_enable(vq, napi);
1732 }
1733 
1734 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1735 {
1736 	if (napi->weight)
1737 		napi_disable(napi);
1738 }
1739 
1740 static void refill_work(struct work_struct *work)
1741 {
1742 	struct virtnet_info *vi =
1743 		container_of(work, struct virtnet_info, refill.work);
1744 	bool still_empty;
1745 	int i;
1746 
1747 	for (i = 0; i < vi->curr_queue_pairs; i++) {
1748 		struct receive_queue *rq = &vi->rq[i];
1749 
1750 		napi_disable(&rq->napi);
1751 		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1752 		virtnet_napi_enable(rq->vq, &rq->napi);
1753 
1754 		/* In theory, this can happen: if we don't get any buffers in
1755 		 * we will *never* try to fill again.
1756 		 */
1757 		if (still_empty)
1758 			schedule_delayed_work(&vi->refill, HZ/2);
1759 	}
1760 }
1761 
1762 static int virtnet_receive(struct receive_queue *rq, int budget,
1763 			   unsigned int *xdp_xmit)
1764 {
1765 	struct virtnet_info *vi = rq->vq->vdev->priv;
1766 	struct virtnet_rq_stats stats = {};
1767 	unsigned int len;
1768 	void *buf;
1769 	int i;
1770 
1771 	if (!vi->big_packets || vi->mergeable_rx_bufs) {
1772 		void *ctx;
1773 
1774 		while (stats.packets < budget &&
1775 		       (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1776 			receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1777 			stats.packets++;
1778 		}
1779 	} else {
1780 		while (stats.packets < budget &&
1781 		       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1782 			receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1783 			stats.packets++;
1784 		}
1785 	}
1786 
1787 	if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1788 		if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
1789 			spin_lock(&vi->refill_lock);
1790 			if (vi->refill_enabled)
1791 				schedule_delayed_work(&vi->refill, 0);
1792 			spin_unlock(&vi->refill_lock);
1793 		}
1794 	}
1795 
1796 	u64_stats_update_begin(&rq->stats.syncp);
1797 	for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1798 		size_t offset = virtnet_rq_stats_desc[i].offset;
1799 		u64 *item;
1800 
1801 		item = (u64 *)((u8 *)&rq->stats + offset);
1802 		*item += *(u64 *)((u8 *)&stats + offset);
1803 	}
1804 	u64_stats_update_end(&rq->stats.syncp);
1805 
1806 	return stats.packets;
1807 }
1808 
1809 static void virtnet_poll_cleantx(struct receive_queue *rq)
1810 {
1811 	struct virtnet_info *vi = rq->vq->vdev->priv;
1812 	unsigned int index = vq2rxq(rq->vq);
1813 	struct send_queue *sq = &vi->sq[index];
1814 	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1815 
1816 	if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1817 		return;
1818 
1819 	if (__netif_tx_trylock(txq)) {
1820 		if (sq->reset) {
1821 			__netif_tx_unlock(txq);
1822 			return;
1823 		}
1824 
1825 		do {
1826 			virtqueue_disable_cb(sq->vq);
1827 			free_old_xmit_skbs(sq, true);
1828 		} while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1829 
1830 		if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1831 			netif_tx_wake_queue(txq);
1832 
1833 		__netif_tx_unlock(txq);
1834 	}
1835 }
1836 
1837 static int virtnet_poll(struct napi_struct *napi, int budget)
1838 {
1839 	struct receive_queue *rq =
1840 		container_of(napi, struct receive_queue, napi);
1841 	struct virtnet_info *vi = rq->vq->vdev->priv;
1842 	struct send_queue *sq;
1843 	unsigned int received;
1844 	unsigned int xdp_xmit = 0;
1845 
1846 	virtnet_poll_cleantx(rq);
1847 
1848 	received = virtnet_receive(rq, budget, &xdp_xmit);
1849 
1850 	if (xdp_xmit & VIRTIO_XDP_REDIR)
1851 		xdp_do_flush();
1852 
1853 	/* Out of packets? */
1854 	if (received < budget)
1855 		virtqueue_napi_complete(napi, rq->vq, received);
1856 
1857 	if (xdp_xmit & VIRTIO_XDP_TX) {
1858 		sq = virtnet_xdp_get_sq(vi);
1859 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1860 			u64_stats_update_begin(&sq->stats.syncp);
1861 			sq->stats.kicks++;
1862 			u64_stats_update_end(&sq->stats.syncp);
1863 		}
1864 		virtnet_xdp_put_sq(vi, sq);
1865 	}
1866 
1867 	return received;
1868 }
1869 
1870 static int virtnet_open(struct net_device *dev)
1871 {
1872 	struct virtnet_info *vi = netdev_priv(dev);
1873 	int i, err;
1874 
1875 	enable_delayed_refill(vi);
1876 
1877 	for (i = 0; i < vi->max_queue_pairs; i++) {
1878 		if (i < vi->curr_queue_pairs)
1879 			/* Make sure we have some buffers: if oom use wq. */
1880 			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1881 				schedule_delayed_work(&vi->refill, 0);
1882 
1883 		err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
1884 		if (err < 0)
1885 			return err;
1886 
1887 		err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1888 						 MEM_TYPE_PAGE_SHARED, NULL);
1889 		if (err < 0) {
1890 			xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1891 			return err;
1892 		}
1893 
1894 		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1895 		virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1896 	}
1897 
1898 	return 0;
1899 }
1900 
1901 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1902 {
1903 	struct send_queue *sq = container_of(napi, struct send_queue, napi);
1904 	struct virtnet_info *vi = sq->vq->vdev->priv;
1905 	unsigned int index = vq2txq(sq->vq);
1906 	struct netdev_queue *txq;
1907 	int opaque;
1908 	bool done;
1909 
1910 	if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1911 		/* We don't need to enable cb for XDP */
1912 		napi_complete_done(napi, 0);
1913 		return 0;
1914 	}
1915 
1916 	txq = netdev_get_tx_queue(vi->dev, index);
1917 	__netif_tx_lock(txq, raw_smp_processor_id());
1918 	virtqueue_disable_cb(sq->vq);
1919 	free_old_xmit_skbs(sq, true);
1920 
1921 	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1922 		netif_tx_wake_queue(txq);
1923 
1924 	opaque = virtqueue_enable_cb_prepare(sq->vq);
1925 
1926 	done = napi_complete_done(napi, 0);
1927 
1928 	if (!done)
1929 		virtqueue_disable_cb(sq->vq);
1930 
1931 	__netif_tx_unlock(txq);
1932 
1933 	if (done) {
1934 		if (unlikely(virtqueue_poll(sq->vq, opaque))) {
1935 			if (napi_schedule_prep(napi)) {
1936 				__netif_tx_lock(txq, raw_smp_processor_id());
1937 				virtqueue_disable_cb(sq->vq);
1938 				__netif_tx_unlock(txq);
1939 				__napi_schedule(napi);
1940 			}
1941 		}
1942 	}
1943 
1944 	return 0;
1945 }
1946 
1947 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1948 {
1949 	struct virtio_net_hdr_mrg_rxbuf *hdr;
1950 	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1951 	struct virtnet_info *vi = sq->vq->vdev->priv;
1952 	int num_sg;
1953 	unsigned hdr_len = vi->hdr_len;
1954 	bool can_push;
1955 
1956 	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1957 
1958 	can_push = vi->any_header_sg &&
1959 		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1960 		!skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1961 	/* Even if we can, don't push here yet as this would skew
1962 	 * csum_start offset below. */
1963 	if (can_push)
1964 		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1965 	else
1966 		hdr = skb_vnet_hdr(skb);
1967 
1968 	if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1969 				    virtio_is_little_endian(vi->vdev), false,
1970 				    0))
1971 		return -EPROTO;
1972 
1973 	if (vi->mergeable_rx_bufs)
1974 		hdr->num_buffers = 0;
1975 
1976 	sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1977 	if (can_push) {
1978 		__skb_push(skb, hdr_len);
1979 		num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1980 		if (unlikely(num_sg < 0))
1981 			return num_sg;
1982 		/* Pull header back to avoid skew in tx bytes calculations. */
1983 		__skb_pull(skb, hdr_len);
1984 	} else {
1985 		sg_set_buf(sq->sg, hdr, hdr_len);
1986 		num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1987 		if (unlikely(num_sg < 0))
1988 			return num_sg;
1989 		num_sg++;
1990 	}
1991 	return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1992 }
1993 
1994 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1995 {
1996 	struct virtnet_info *vi = netdev_priv(dev);
1997 	int qnum = skb_get_queue_mapping(skb);
1998 	struct send_queue *sq = &vi->sq[qnum];
1999 	int err;
2000 	struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
2001 	bool kick = !netdev_xmit_more();
2002 	bool use_napi = sq->napi.weight;
2003 
2004 	/* Free up any pending old buffers before queueing new ones. */
2005 	do {
2006 		if (use_napi)
2007 			virtqueue_disable_cb(sq->vq);
2008 
2009 		free_old_xmit_skbs(sq, false);
2010 
2011 	} while (use_napi && kick &&
2012 	       unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
2013 
2014 	/* timestamp packet in software */
2015 	skb_tx_timestamp(skb);
2016 
2017 	/* Try to transmit */
2018 	err = xmit_skb(sq, skb);
2019 
2020 	/* This should not happen! */
2021 	if (unlikely(err)) {
2022 		dev->stats.tx_fifo_errors++;
2023 		if (net_ratelimit())
2024 			dev_warn(&dev->dev,
2025 				 "Unexpected TXQ (%d) queue failure: %d\n",
2026 				 qnum, err);
2027 		dev->stats.tx_dropped++;
2028 		dev_kfree_skb_any(skb);
2029 		return NETDEV_TX_OK;
2030 	}
2031 
2032 	/* Don't wait up for transmitted skbs to be freed. */
2033 	if (!use_napi) {
2034 		skb_orphan(skb);
2035 		nf_reset_ct(skb);
2036 	}
2037 
2038 	check_sq_full_and_disable(vi, dev, sq);
2039 
2040 	if (kick || netif_xmit_stopped(txq)) {
2041 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
2042 			u64_stats_update_begin(&sq->stats.syncp);
2043 			sq->stats.kicks++;
2044 			u64_stats_update_end(&sq->stats.syncp);
2045 		}
2046 	}
2047 
2048 	return NETDEV_TX_OK;
2049 }
2050 
2051 static int virtnet_rx_resize(struct virtnet_info *vi,
2052 			     struct receive_queue *rq, u32 ring_num)
2053 {
2054 	bool running = netif_running(vi->dev);
2055 	int err, qindex;
2056 
2057 	qindex = rq - vi->rq;
2058 
2059 	if (running)
2060 		napi_disable(&rq->napi);
2061 
2062 	err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
2063 	if (err)
2064 		netdev_err(vi->dev, "resize rx fail: rx queue index: %d err: %d\n", qindex, err);
2065 
2066 	if (!try_fill_recv(vi, rq, GFP_KERNEL))
2067 		schedule_delayed_work(&vi->refill, 0);
2068 
2069 	if (running)
2070 		virtnet_napi_enable(rq->vq, &rq->napi);
2071 	return err;
2072 }
2073 
2074 static int virtnet_tx_resize(struct virtnet_info *vi,
2075 			     struct send_queue *sq, u32 ring_num)
2076 {
2077 	bool running = netif_running(vi->dev);
2078 	struct netdev_queue *txq;
2079 	int err, qindex;
2080 
2081 	qindex = sq - vi->sq;
2082 
2083 	if (running)
2084 		virtnet_napi_tx_disable(&sq->napi);
2085 
2086 	txq = netdev_get_tx_queue(vi->dev, qindex);
2087 
2088 	/* 1. wait all ximt complete
2089 	 * 2. fix the race of netif_stop_subqueue() vs netif_start_subqueue()
2090 	 */
2091 	__netif_tx_lock_bh(txq);
2092 
2093 	/* Prevent rx poll from accessing sq. */
2094 	sq->reset = true;
2095 
2096 	/* Prevent the upper layer from trying to send packets. */
2097 	netif_stop_subqueue(vi->dev, qindex);
2098 
2099 	__netif_tx_unlock_bh(txq);
2100 
2101 	err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
2102 	if (err)
2103 		netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
2104 
2105 	__netif_tx_lock_bh(txq);
2106 	sq->reset = false;
2107 	netif_tx_wake_queue(txq);
2108 	__netif_tx_unlock_bh(txq);
2109 
2110 	if (running)
2111 		virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
2112 	return err;
2113 }
2114 
2115 /*
2116  * Send command via the control virtqueue and check status.  Commands
2117  * supported by the hypervisor, as indicated by feature bits, should
2118  * never fail unless improperly formatted.
2119  */
2120 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
2121 				 struct scatterlist *out)
2122 {
2123 	struct scatterlist *sgs[4], hdr, stat;
2124 	unsigned out_num = 0, tmp;
2125 	int ret;
2126 
2127 	/* Caller should know better */
2128 	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
2129 
2130 	vi->ctrl->status = ~0;
2131 	vi->ctrl->hdr.class = class;
2132 	vi->ctrl->hdr.cmd = cmd;
2133 	/* Add header */
2134 	sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
2135 	sgs[out_num++] = &hdr;
2136 
2137 	if (out)
2138 		sgs[out_num++] = out;
2139 
2140 	/* Add return status. */
2141 	sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
2142 	sgs[out_num] = &stat;
2143 
2144 	BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
2145 	ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
2146 	if (ret < 0) {
2147 		dev_warn(&vi->vdev->dev,
2148 			 "Failed to add sgs for command vq: %d\n.", ret);
2149 		return false;
2150 	}
2151 
2152 	if (unlikely(!virtqueue_kick(vi->cvq)))
2153 		return vi->ctrl->status == VIRTIO_NET_OK;
2154 
2155 	/* Spin for a response, the kick causes an ioport write, trapping
2156 	 * into the hypervisor, so the request should be handled immediately.
2157 	 */
2158 	while (!virtqueue_get_buf(vi->cvq, &tmp) &&
2159 	       !virtqueue_is_broken(vi->cvq))
2160 		cpu_relax();
2161 
2162 	return vi->ctrl->status == VIRTIO_NET_OK;
2163 }
2164 
2165 static int virtnet_set_mac_address(struct net_device *dev, void *p)
2166 {
2167 	struct virtnet_info *vi = netdev_priv(dev);
2168 	struct virtio_device *vdev = vi->vdev;
2169 	int ret;
2170 	struct sockaddr *addr;
2171 	struct scatterlist sg;
2172 
2173 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2174 		return -EOPNOTSUPP;
2175 
2176 	addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
2177 	if (!addr)
2178 		return -ENOMEM;
2179 
2180 	ret = eth_prepare_mac_addr_change(dev, addr);
2181 	if (ret)
2182 		goto out;
2183 
2184 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
2185 		sg_init_one(&sg, addr->sa_data, dev->addr_len);
2186 		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2187 					  VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
2188 			dev_warn(&vdev->dev,
2189 				 "Failed to set mac address by vq command.\n");
2190 			ret = -EINVAL;
2191 			goto out;
2192 		}
2193 	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
2194 		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
2195 		unsigned int i;
2196 
2197 		/* Naturally, this has an atomicity problem. */
2198 		for (i = 0; i < dev->addr_len; i++)
2199 			virtio_cwrite8(vdev,
2200 				       offsetof(struct virtio_net_config, mac) +
2201 				       i, addr->sa_data[i]);
2202 	}
2203 
2204 	eth_commit_mac_addr_change(dev, p);
2205 	ret = 0;
2206 
2207 out:
2208 	kfree(addr);
2209 	return ret;
2210 }
2211 
2212 static void virtnet_stats(struct net_device *dev,
2213 			  struct rtnl_link_stats64 *tot)
2214 {
2215 	struct virtnet_info *vi = netdev_priv(dev);
2216 	unsigned int start;
2217 	int i;
2218 
2219 	for (i = 0; i < vi->max_queue_pairs; i++) {
2220 		u64 tpackets, tbytes, terrors, rpackets, rbytes, rdrops;
2221 		struct receive_queue *rq = &vi->rq[i];
2222 		struct send_queue *sq = &vi->sq[i];
2223 
2224 		do {
2225 			start = u64_stats_fetch_begin(&sq->stats.syncp);
2226 			tpackets = sq->stats.packets;
2227 			tbytes   = sq->stats.bytes;
2228 			terrors  = sq->stats.tx_timeouts;
2229 		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2230 
2231 		do {
2232 			start = u64_stats_fetch_begin(&rq->stats.syncp);
2233 			rpackets = rq->stats.packets;
2234 			rbytes   = rq->stats.bytes;
2235 			rdrops   = rq->stats.drops;
2236 		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2237 
2238 		tot->rx_packets += rpackets;
2239 		tot->tx_packets += tpackets;
2240 		tot->rx_bytes   += rbytes;
2241 		tot->tx_bytes   += tbytes;
2242 		tot->rx_dropped += rdrops;
2243 		tot->tx_errors  += terrors;
2244 	}
2245 
2246 	tot->tx_dropped = dev->stats.tx_dropped;
2247 	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
2248 	tot->rx_length_errors = dev->stats.rx_length_errors;
2249 	tot->rx_frame_errors = dev->stats.rx_frame_errors;
2250 }
2251 
2252 static void virtnet_ack_link_announce(struct virtnet_info *vi)
2253 {
2254 	rtnl_lock();
2255 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
2256 				  VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
2257 		dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
2258 	rtnl_unlock();
2259 }
2260 
2261 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2262 {
2263 	struct scatterlist sg;
2264 	struct net_device *dev = vi->dev;
2265 
2266 	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
2267 		return 0;
2268 
2269 	vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
2270 	sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
2271 
2272 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2273 				  VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
2274 		dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
2275 			 queue_pairs);
2276 		return -EINVAL;
2277 	} else {
2278 		vi->curr_queue_pairs = queue_pairs;
2279 		/* virtnet_open() will refill when device is going to up. */
2280 		if (dev->flags & IFF_UP)
2281 			schedule_delayed_work(&vi->refill, 0);
2282 	}
2283 
2284 	return 0;
2285 }
2286 
2287 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2288 {
2289 	int err;
2290 
2291 	rtnl_lock();
2292 	err = _virtnet_set_queues(vi, queue_pairs);
2293 	rtnl_unlock();
2294 	return err;
2295 }
2296 
2297 static int virtnet_close(struct net_device *dev)
2298 {
2299 	struct virtnet_info *vi = netdev_priv(dev);
2300 	int i;
2301 
2302 	/* Make sure NAPI doesn't schedule refill work */
2303 	disable_delayed_refill(vi);
2304 	/* Make sure refill_work doesn't re-enable napi! */
2305 	cancel_delayed_work_sync(&vi->refill);
2306 
2307 	for (i = 0; i < vi->max_queue_pairs; i++) {
2308 		virtnet_napi_tx_disable(&vi->sq[i].napi);
2309 		napi_disable(&vi->rq[i].napi);
2310 		xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
2311 	}
2312 
2313 	return 0;
2314 }
2315 
2316 static void virtnet_set_rx_mode(struct net_device *dev)
2317 {
2318 	struct virtnet_info *vi = netdev_priv(dev);
2319 	struct scatterlist sg[2];
2320 	struct virtio_net_ctrl_mac *mac_data;
2321 	struct netdev_hw_addr *ha;
2322 	int uc_count;
2323 	int mc_count;
2324 	void *buf;
2325 	int i;
2326 
2327 	/* We can't dynamically set ndo_set_rx_mode, so return gracefully */
2328 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
2329 		return;
2330 
2331 	vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
2332 	vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
2333 
2334 	sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
2335 
2336 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2337 				  VIRTIO_NET_CTRL_RX_PROMISC, sg))
2338 		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
2339 			 vi->ctrl->promisc ? "en" : "dis");
2340 
2341 	sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
2342 
2343 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2344 				  VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
2345 		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
2346 			 vi->ctrl->allmulti ? "en" : "dis");
2347 
2348 	uc_count = netdev_uc_count(dev);
2349 	mc_count = netdev_mc_count(dev);
2350 	/* MAC filter - use one buffer for both lists */
2351 	buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
2352 		      (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
2353 	mac_data = buf;
2354 	if (!buf)
2355 		return;
2356 
2357 	sg_init_table(sg, 2);
2358 
2359 	/* Store the unicast list and count in the front of the buffer */
2360 	mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
2361 	i = 0;
2362 	netdev_for_each_uc_addr(ha, dev)
2363 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2364 
2365 	sg_set_buf(&sg[0], mac_data,
2366 		   sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
2367 
2368 	/* multicast list and count fill the end */
2369 	mac_data = (void *)&mac_data->macs[uc_count][0];
2370 
2371 	mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
2372 	i = 0;
2373 	netdev_for_each_mc_addr(ha, dev)
2374 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2375 
2376 	sg_set_buf(&sg[1], mac_data,
2377 		   sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
2378 
2379 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2380 				  VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
2381 		dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
2382 
2383 	kfree(buf);
2384 }
2385 
2386 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
2387 				   __be16 proto, u16 vid)
2388 {
2389 	struct virtnet_info *vi = netdev_priv(dev);
2390 	struct scatterlist sg;
2391 
2392 	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2393 	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2394 
2395 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2396 				  VIRTIO_NET_CTRL_VLAN_ADD, &sg))
2397 		dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
2398 	return 0;
2399 }
2400 
2401 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
2402 				    __be16 proto, u16 vid)
2403 {
2404 	struct virtnet_info *vi = netdev_priv(dev);
2405 	struct scatterlist sg;
2406 
2407 	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2408 	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2409 
2410 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2411 				  VIRTIO_NET_CTRL_VLAN_DEL, &sg))
2412 		dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
2413 	return 0;
2414 }
2415 
2416 static void virtnet_clean_affinity(struct virtnet_info *vi)
2417 {
2418 	int i;
2419 
2420 	if (vi->affinity_hint_set) {
2421 		for (i = 0; i < vi->max_queue_pairs; i++) {
2422 			virtqueue_set_affinity(vi->rq[i].vq, NULL);
2423 			virtqueue_set_affinity(vi->sq[i].vq, NULL);
2424 		}
2425 
2426 		vi->affinity_hint_set = false;
2427 	}
2428 }
2429 
2430 static void virtnet_set_affinity(struct virtnet_info *vi)
2431 {
2432 	cpumask_var_t mask;
2433 	int stragglers;
2434 	int group_size;
2435 	int i, j, cpu;
2436 	int num_cpu;
2437 	int stride;
2438 
2439 	if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
2440 		virtnet_clean_affinity(vi);
2441 		return;
2442 	}
2443 
2444 	num_cpu = num_online_cpus();
2445 	stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
2446 	stragglers = num_cpu >= vi->curr_queue_pairs ?
2447 			num_cpu % vi->curr_queue_pairs :
2448 			0;
2449 	cpu = cpumask_first(cpu_online_mask);
2450 
2451 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2452 		group_size = stride + (i < stragglers ? 1 : 0);
2453 
2454 		for (j = 0; j < group_size; j++) {
2455 			cpumask_set_cpu(cpu, mask);
2456 			cpu = cpumask_next_wrap(cpu, cpu_online_mask,
2457 						nr_cpu_ids, false);
2458 		}
2459 		virtqueue_set_affinity(vi->rq[i].vq, mask);
2460 		virtqueue_set_affinity(vi->sq[i].vq, mask);
2461 		__netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, XPS_CPUS);
2462 		cpumask_clear(mask);
2463 	}
2464 
2465 	vi->affinity_hint_set = true;
2466 	free_cpumask_var(mask);
2467 }
2468 
2469 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
2470 {
2471 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2472 						   node);
2473 	virtnet_set_affinity(vi);
2474 	return 0;
2475 }
2476 
2477 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
2478 {
2479 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2480 						   node_dead);
2481 	virtnet_set_affinity(vi);
2482 	return 0;
2483 }
2484 
2485 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
2486 {
2487 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2488 						   node);
2489 
2490 	virtnet_clean_affinity(vi);
2491 	return 0;
2492 }
2493 
2494 static enum cpuhp_state virtionet_online;
2495 
2496 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
2497 {
2498 	int ret;
2499 
2500 	ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2501 	if (ret)
2502 		return ret;
2503 	ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2504 					       &vi->node_dead);
2505 	if (!ret)
2506 		return ret;
2507 	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2508 	return ret;
2509 }
2510 
2511 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2512 {
2513 	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2514 	cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2515 					    &vi->node_dead);
2516 }
2517 
2518 static void virtnet_get_ringparam(struct net_device *dev,
2519 				  struct ethtool_ringparam *ring,
2520 				  struct kernel_ethtool_ringparam *kernel_ring,
2521 				  struct netlink_ext_ack *extack)
2522 {
2523 	struct virtnet_info *vi = netdev_priv(dev);
2524 
2525 	ring->rx_max_pending = vi->rq[0].vq->num_max;
2526 	ring->tx_max_pending = vi->sq[0].vq->num_max;
2527 	ring->rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2528 	ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2529 }
2530 
2531 static int virtnet_set_ringparam(struct net_device *dev,
2532 				 struct ethtool_ringparam *ring,
2533 				 struct kernel_ethtool_ringparam *kernel_ring,
2534 				 struct netlink_ext_ack *extack)
2535 {
2536 	struct virtnet_info *vi = netdev_priv(dev);
2537 	u32 rx_pending, tx_pending;
2538 	struct receive_queue *rq;
2539 	struct send_queue *sq;
2540 	int i, err;
2541 
2542 	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
2543 		return -EINVAL;
2544 
2545 	rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2546 	tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2547 
2548 	if (ring->rx_pending == rx_pending &&
2549 	    ring->tx_pending == tx_pending)
2550 		return 0;
2551 
2552 	if (ring->rx_pending > vi->rq[0].vq->num_max)
2553 		return -EINVAL;
2554 
2555 	if (ring->tx_pending > vi->sq[0].vq->num_max)
2556 		return -EINVAL;
2557 
2558 	for (i = 0; i < vi->max_queue_pairs; i++) {
2559 		rq = vi->rq + i;
2560 		sq = vi->sq + i;
2561 
2562 		if (ring->tx_pending != tx_pending) {
2563 			err = virtnet_tx_resize(vi, sq, ring->tx_pending);
2564 			if (err)
2565 				return err;
2566 		}
2567 
2568 		if (ring->rx_pending != rx_pending) {
2569 			err = virtnet_rx_resize(vi, rq, ring->rx_pending);
2570 			if (err)
2571 				return err;
2572 		}
2573 	}
2574 
2575 	return 0;
2576 }
2577 
2578 static bool virtnet_commit_rss_command(struct virtnet_info *vi)
2579 {
2580 	struct net_device *dev = vi->dev;
2581 	struct scatterlist sgs[4];
2582 	unsigned int sg_buf_size;
2583 
2584 	/* prepare sgs */
2585 	sg_init_table(sgs, 4);
2586 
2587 	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, indirection_table);
2588 	sg_set_buf(&sgs[0], &vi->ctrl->rss, sg_buf_size);
2589 
2590 	sg_buf_size = sizeof(uint16_t) * (vi->ctrl->rss.indirection_table_mask + 1);
2591 	sg_set_buf(&sgs[1], vi->ctrl->rss.indirection_table, sg_buf_size);
2592 
2593 	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, key)
2594 			- offsetof(struct virtio_net_ctrl_rss, max_tx_vq);
2595 	sg_set_buf(&sgs[2], &vi->ctrl->rss.max_tx_vq, sg_buf_size);
2596 
2597 	sg_buf_size = vi->rss_key_size;
2598 	sg_set_buf(&sgs[3], vi->ctrl->rss.key, sg_buf_size);
2599 
2600 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2601 				  vi->has_rss ? VIRTIO_NET_CTRL_MQ_RSS_CONFIG
2602 				  : VIRTIO_NET_CTRL_MQ_HASH_CONFIG, sgs)) {
2603 		dev_warn(&dev->dev, "VIRTIONET issue with committing RSS sgs\n");
2604 		return false;
2605 	}
2606 	return true;
2607 }
2608 
2609 static void virtnet_init_default_rss(struct virtnet_info *vi)
2610 {
2611 	u32 indir_val = 0;
2612 	int i = 0;
2613 
2614 	vi->ctrl->rss.hash_types = vi->rss_hash_types_supported;
2615 	vi->rss_hash_types_saved = vi->rss_hash_types_supported;
2616 	vi->ctrl->rss.indirection_table_mask = vi->rss_indir_table_size
2617 						? vi->rss_indir_table_size - 1 : 0;
2618 	vi->ctrl->rss.unclassified_queue = 0;
2619 
2620 	for (; i < vi->rss_indir_table_size; ++i) {
2621 		indir_val = ethtool_rxfh_indir_default(i, vi->curr_queue_pairs);
2622 		vi->ctrl->rss.indirection_table[i] = indir_val;
2623 	}
2624 
2625 	vi->ctrl->rss.max_tx_vq = vi->curr_queue_pairs;
2626 	vi->ctrl->rss.hash_key_length = vi->rss_key_size;
2627 
2628 	netdev_rss_key_fill(vi->ctrl->rss.key, vi->rss_key_size);
2629 }
2630 
2631 static void virtnet_get_hashflow(const struct virtnet_info *vi, struct ethtool_rxnfc *info)
2632 {
2633 	info->data = 0;
2634 	switch (info->flow_type) {
2635 	case TCP_V4_FLOW:
2636 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
2637 			info->data = RXH_IP_SRC | RXH_IP_DST |
2638 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2639 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2640 			info->data = RXH_IP_SRC | RXH_IP_DST;
2641 		}
2642 		break;
2643 	case TCP_V6_FLOW:
2644 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
2645 			info->data = RXH_IP_SRC | RXH_IP_DST |
2646 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2647 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2648 			info->data = RXH_IP_SRC | RXH_IP_DST;
2649 		}
2650 		break;
2651 	case UDP_V4_FLOW:
2652 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
2653 			info->data = RXH_IP_SRC | RXH_IP_DST |
2654 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2655 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2656 			info->data = RXH_IP_SRC | RXH_IP_DST;
2657 		}
2658 		break;
2659 	case UDP_V6_FLOW:
2660 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
2661 			info->data = RXH_IP_SRC | RXH_IP_DST |
2662 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2663 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2664 			info->data = RXH_IP_SRC | RXH_IP_DST;
2665 		}
2666 		break;
2667 	case IPV4_FLOW:
2668 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4)
2669 			info->data = RXH_IP_SRC | RXH_IP_DST;
2670 
2671 		break;
2672 	case IPV6_FLOW:
2673 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6)
2674 			info->data = RXH_IP_SRC | RXH_IP_DST;
2675 
2676 		break;
2677 	default:
2678 		info->data = 0;
2679 		break;
2680 	}
2681 }
2682 
2683 static bool virtnet_set_hashflow(struct virtnet_info *vi, struct ethtool_rxnfc *info)
2684 {
2685 	u32 new_hashtypes = vi->rss_hash_types_saved;
2686 	bool is_disable = info->data & RXH_DISCARD;
2687 	bool is_l4 = info->data == (RXH_IP_SRC | RXH_IP_DST | RXH_L4_B_0_1 | RXH_L4_B_2_3);
2688 
2689 	/* supports only 'sd', 'sdfn' and 'r' */
2690 	if (!((info->data == (RXH_IP_SRC | RXH_IP_DST)) | is_l4 | is_disable))
2691 		return false;
2692 
2693 	switch (info->flow_type) {
2694 	case TCP_V4_FLOW:
2695 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_TCPv4);
2696 		if (!is_disable)
2697 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2698 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv4 : 0);
2699 		break;
2700 	case UDP_V4_FLOW:
2701 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_UDPv4);
2702 		if (!is_disable)
2703 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2704 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv4 : 0);
2705 		break;
2706 	case IPV4_FLOW:
2707 		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2708 		if (!is_disable)
2709 			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2710 		break;
2711 	case TCP_V6_FLOW:
2712 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_TCPv6);
2713 		if (!is_disable)
2714 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2715 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv6 : 0);
2716 		break;
2717 	case UDP_V6_FLOW:
2718 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_UDPv6);
2719 		if (!is_disable)
2720 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2721 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv6 : 0);
2722 		break;
2723 	case IPV6_FLOW:
2724 		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2725 		if (!is_disable)
2726 			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2727 		break;
2728 	default:
2729 		/* unsupported flow */
2730 		return false;
2731 	}
2732 
2733 	/* if unsupported hashtype was set */
2734 	if (new_hashtypes != (new_hashtypes & vi->rss_hash_types_supported))
2735 		return false;
2736 
2737 	if (new_hashtypes != vi->rss_hash_types_saved) {
2738 		vi->rss_hash_types_saved = new_hashtypes;
2739 		vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
2740 		if (vi->dev->features & NETIF_F_RXHASH)
2741 			return virtnet_commit_rss_command(vi);
2742 	}
2743 
2744 	return true;
2745 }
2746 
2747 static void virtnet_get_drvinfo(struct net_device *dev,
2748 				struct ethtool_drvinfo *info)
2749 {
2750 	struct virtnet_info *vi = netdev_priv(dev);
2751 	struct virtio_device *vdev = vi->vdev;
2752 
2753 	strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2754 	strscpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2755 	strscpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2756 
2757 }
2758 
2759 /* TODO: Eliminate OOO packets during switching */
2760 static int virtnet_set_channels(struct net_device *dev,
2761 				struct ethtool_channels *channels)
2762 {
2763 	struct virtnet_info *vi = netdev_priv(dev);
2764 	u16 queue_pairs = channels->combined_count;
2765 	int err;
2766 
2767 	/* We don't support separate rx/tx channels.
2768 	 * We don't allow setting 'other' channels.
2769 	 */
2770 	if (channels->rx_count || channels->tx_count || channels->other_count)
2771 		return -EINVAL;
2772 
2773 	if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2774 		return -EINVAL;
2775 
2776 	/* For now we don't support modifying channels while XDP is loaded
2777 	 * also when XDP is loaded all RX queues have XDP programs so we only
2778 	 * need to check a single RX queue.
2779 	 */
2780 	if (vi->rq[0].xdp_prog)
2781 		return -EINVAL;
2782 
2783 	cpus_read_lock();
2784 	err = _virtnet_set_queues(vi, queue_pairs);
2785 	if (err) {
2786 		cpus_read_unlock();
2787 		goto err;
2788 	}
2789 	virtnet_set_affinity(vi);
2790 	cpus_read_unlock();
2791 
2792 	netif_set_real_num_tx_queues(dev, queue_pairs);
2793 	netif_set_real_num_rx_queues(dev, queue_pairs);
2794  err:
2795 	return err;
2796 }
2797 
2798 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2799 {
2800 	struct virtnet_info *vi = netdev_priv(dev);
2801 	unsigned int i, j;
2802 	u8 *p = data;
2803 
2804 	switch (stringset) {
2805 	case ETH_SS_STATS:
2806 		for (i = 0; i < vi->curr_queue_pairs; i++) {
2807 			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++)
2808 				ethtool_sprintf(&p, "rx_queue_%u_%s", i,
2809 						virtnet_rq_stats_desc[j].desc);
2810 		}
2811 
2812 		for (i = 0; i < vi->curr_queue_pairs; i++) {
2813 			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++)
2814 				ethtool_sprintf(&p, "tx_queue_%u_%s", i,
2815 						virtnet_sq_stats_desc[j].desc);
2816 		}
2817 		break;
2818 	}
2819 }
2820 
2821 static int virtnet_get_sset_count(struct net_device *dev, int sset)
2822 {
2823 	struct virtnet_info *vi = netdev_priv(dev);
2824 
2825 	switch (sset) {
2826 	case ETH_SS_STATS:
2827 		return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2828 					       VIRTNET_SQ_STATS_LEN);
2829 	default:
2830 		return -EOPNOTSUPP;
2831 	}
2832 }
2833 
2834 static void virtnet_get_ethtool_stats(struct net_device *dev,
2835 				      struct ethtool_stats *stats, u64 *data)
2836 {
2837 	struct virtnet_info *vi = netdev_priv(dev);
2838 	unsigned int idx = 0, start, i, j;
2839 	const u8 *stats_base;
2840 	size_t offset;
2841 
2842 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2843 		struct receive_queue *rq = &vi->rq[i];
2844 
2845 		stats_base = (u8 *)&rq->stats;
2846 		do {
2847 			start = u64_stats_fetch_begin(&rq->stats.syncp);
2848 			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2849 				offset = virtnet_rq_stats_desc[j].offset;
2850 				data[idx + j] = *(u64 *)(stats_base + offset);
2851 			}
2852 		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2853 		idx += VIRTNET_RQ_STATS_LEN;
2854 	}
2855 
2856 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2857 		struct send_queue *sq = &vi->sq[i];
2858 
2859 		stats_base = (u8 *)&sq->stats;
2860 		do {
2861 			start = u64_stats_fetch_begin(&sq->stats.syncp);
2862 			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2863 				offset = virtnet_sq_stats_desc[j].offset;
2864 				data[idx + j] = *(u64 *)(stats_base + offset);
2865 			}
2866 		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2867 		idx += VIRTNET_SQ_STATS_LEN;
2868 	}
2869 }
2870 
2871 static void virtnet_get_channels(struct net_device *dev,
2872 				 struct ethtool_channels *channels)
2873 {
2874 	struct virtnet_info *vi = netdev_priv(dev);
2875 
2876 	channels->combined_count = vi->curr_queue_pairs;
2877 	channels->max_combined = vi->max_queue_pairs;
2878 	channels->max_other = 0;
2879 	channels->rx_count = 0;
2880 	channels->tx_count = 0;
2881 	channels->other_count = 0;
2882 }
2883 
2884 static int virtnet_set_link_ksettings(struct net_device *dev,
2885 				      const struct ethtool_link_ksettings *cmd)
2886 {
2887 	struct virtnet_info *vi = netdev_priv(dev);
2888 
2889 	return ethtool_virtdev_set_link_ksettings(dev, cmd,
2890 						  &vi->speed, &vi->duplex);
2891 }
2892 
2893 static int virtnet_get_link_ksettings(struct net_device *dev,
2894 				      struct ethtool_link_ksettings *cmd)
2895 {
2896 	struct virtnet_info *vi = netdev_priv(dev);
2897 
2898 	cmd->base.speed = vi->speed;
2899 	cmd->base.duplex = vi->duplex;
2900 	cmd->base.port = PORT_OTHER;
2901 
2902 	return 0;
2903 }
2904 
2905 static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
2906 				       struct ethtool_coalesce *ec)
2907 {
2908 	struct scatterlist sgs_tx, sgs_rx;
2909 	struct virtio_net_ctrl_coal_tx coal_tx;
2910 	struct virtio_net_ctrl_coal_rx coal_rx;
2911 
2912 	coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
2913 	coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
2914 	sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
2915 
2916 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2917 				  VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
2918 				  &sgs_tx))
2919 		return -EINVAL;
2920 
2921 	/* Save parameters */
2922 	vi->tx_usecs = ec->tx_coalesce_usecs;
2923 	vi->tx_max_packets = ec->tx_max_coalesced_frames;
2924 
2925 	coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
2926 	coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
2927 	sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
2928 
2929 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2930 				  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
2931 				  &sgs_rx))
2932 		return -EINVAL;
2933 
2934 	/* Save parameters */
2935 	vi->rx_usecs = ec->rx_coalesce_usecs;
2936 	vi->rx_max_packets = ec->rx_max_coalesced_frames;
2937 
2938 	return 0;
2939 }
2940 
2941 static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
2942 {
2943 	/* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
2944 	 * feature is negotiated.
2945 	 */
2946 	if (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs)
2947 		return -EOPNOTSUPP;
2948 
2949 	if (ec->tx_max_coalesced_frames > 1 ||
2950 	    ec->rx_max_coalesced_frames != 1)
2951 		return -EINVAL;
2952 
2953 	return 0;
2954 }
2955 
2956 static int virtnet_set_coalesce(struct net_device *dev,
2957 				struct ethtool_coalesce *ec,
2958 				struct kernel_ethtool_coalesce *kernel_coal,
2959 				struct netlink_ext_ack *extack)
2960 {
2961 	struct virtnet_info *vi = netdev_priv(dev);
2962 	int ret, i, napi_weight;
2963 	bool update_napi = false;
2964 
2965 	/* Can't change NAPI weight if the link is up */
2966 	napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2967 	if (napi_weight ^ vi->sq[0].napi.weight) {
2968 		if (dev->flags & IFF_UP)
2969 			return -EBUSY;
2970 		else
2971 			update_napi = true;
2972 	}
2973 
2974 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL))
2975 		ret = virtnet_send_notf_coal_cmds(vi, ec);
2976 	else
2977 		ret = virtnet_coal_params_supported(ec);
2978 
2979 	if (ret)
2980 		return ret;
2981 
2982 	if (update_napi) {
2983 		for (i = 0; i < vi->max_queue_pairs; i++)
2984 			vi->sq[i].napi.weight = napi_weight;
2985 	}
2986 
2987 	return ret;
2988 }
2989 
2990 static int virtnet_get_coalesce(struct net_device *dev,
2991 				struct ethtool_coalesce *ec,
2992 				struct kernel_ethtool_coalesce *kernel_coal,
2993 				struct netlink_ext_ack *extack)
2994 {
2995 	struct virtnet_info *vi = netdev_priv(dev);
2996 
2997 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
2998 		ec->rx_coalesce_usecs = vi->rx_usecs;
2999 		ec->tx_coalesce_usecs = vi->tx_usecs;
3000 		ec->tx_max_coalesced_frames = vi->tx_max_packets;
3001 		ec->rx_max_coalesced_frames = vi->rx_max_packets;
3002 	} else {
3003 		ec->rx_max_coalesced_frames = 1;
3004 
3005 		if (vi->sq[0].napi.weight)
3006 			ec->tx_max_coalesced_frames = 1;
3007 	}
3008 
3009 	return 0;
3010 }
3011 
3012 static void virtnet_init_settings(struct net_device *dev)
3013 {
3014 	struct virtnet_info *vi = netdev_priv(dev);
3015 
3016 	vi->speed = SPEED_UNKNOWN;
3017 	vi->duplex = DUPLEX_UNKNOWN;
3018 }
3019 
3020 static void virtnet_update_settings(struct virtnet_info *vi)
3021 {
3022 	u32 speed;
3023 	u8 duplex;
3024 
3025 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
3026 		return;
3027 
3028 	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
3029 
3030 	if (ethtool_validate_speed(speed))
3031 		vi->speed = speed;
3032 
3033 	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
3034 
3035 	if (ethtool_validate_duplex(duplex))
3036 		vi->duplex = duplex;
3037 }
3038 
3039 static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
3040 {
3041 	return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
3042 }
3043 
3044 static u32 virtnet_get_rxfh_indir_size(struct net_device *dev)
3045 {
3046 	return ((struct virtnet_info *)netdev_priv(dev))->rss_indir_table_size;
3047 }
3048 
3049 static int virtnet_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfunc)
3050 {
3051 	struct virtnet_info *vi = netdev_priv(dev);
3052 	int i;
3053 
3054 	if (indir) {
3055 		for (i = 0; i < vi->rss_indir_table_size; ++i)
3056 			indir[i] = vi->ctrl->rss.indirection_table[i];
3057 	}
3058 
3059 	if (key)
3060 		memcpy(key, vi->ctrl->rss.key, vi->rss_key_size);
3061 
3062 	if (hfunc)
3063 		*hfunc = ETH_RSS_HASH_TOP;
3064 
3065 	return 0;
3066 }
3067 
3068 static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key, const u8 hfunc)
3069 {
3070 	struct virtnet_info *vi = netdev_priv(dev);
3071 	int i;
3072 
3073 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
3074 		return -EOPNOTSUPP;
3075 
3076 	if (indir) {
3077 		for (i = 0; i < vi->rss_indir_table_size; ++i)
3078 			vi->ctrl->rss.indirection_table[i] = indir[i];
3079 	}
3080 	if (key)
3081 		memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);
3082 
3083 	virtnet_commit_rss_command(vi);
3084 
3085 	return 0;
3086 }
3087 
3088 static int virtnet_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info, u32 *rule_locs)
3089 {
3090 	struct virtnet_info *vi = netdev_priv(dev);
3091 	int rc = 0;
3092 
3093 	switch (info->cmd) {
3094 	case ETHTOOL_GRXRINGS:
3095 		info->data = vi->curr_queue_pairs;
3096 		break;
3097 	case ETHTOOL_GRXFH:
3098 		virtnet_get_hashflow(vi, info);
3099 		break;
3100 	default:
3101 		rc = -EOPNOTSUPP;
3102 	}
3103 
3104 	return rc;
3105 }
3106 
3107 static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info)
3108 {
3109 	struct virtnet_info *vi = netdev_priv(dev);
3110 	int rc = 0;
3111 
3112 	switch (info->cmd) {
3113 	case ETHTOOL_SRXFH:
3114 		if (!virtnet_set_hashflow(vi, info))
3115 			rc = -EINVAL;
3116 
3117 		break;
3118 	default:
3119 		rc = -EOPNOTSUPP;
3120 	}
3121 
3122 	return rc;
3123 }
3124 
3125 static const struct ethtool_ops virtnet_ethtool_ops = {
3126 	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
3127 		ETHTOOL_COALESCE_USECS,
3128 	.get_drvinfo = virtnet_get_drvinfo,
3129 	.get_link = ethtool_op_get_link,
3130 	.get_ringparam = virtnet_get_ringparam,
3131 	.set_ringparam = virtnet_set_ringparam,
3132 	.get_strings = virtnet_get_strings,
3133 	.get_sset_count = virtnet_get_sset_count,
3134 	.get_ethtool_stats = virtnet_get_ethtool_stats,
3135 	.set_channels = virtnet_set_channels,
3136 	.get_channels = virtnet_get_channels,
3137 	.get_ts_info = ethtool_op_get_ts_info,
3138 	.get_link_ksettings = virtnet_get_link_ksettings,
3139 	.set_link_ksettings = virtnet_set_link_ksettings,
3140 	.set_coalesce = virtnet_set_coalesce,
3141 	.get_coalesce = virtnet_get_coalesce,
3142 	.get_rxfh_key_size = virtnet_get_rxfh_key_size,
3143 	.get_rxfh_indir_size = virtnet_get_rxfh_indir_size,
3144 	.get_rxfh = virtnet_get_rxfh,
3145 	.set_rxfh = virtnet_set_rxfh,
3146 	.get_rxnfc = virtnet_get_rxnfc,
3147 	.set_rxnfc = virtnet_set_rxnfc,
3148 };
3149 
3150 static void virtnet_freeze_down(struct virtio_device *vdev)
3151 {
3152 	struct virtnet_info *vi = vdev->priv;
3153 
3154 	/* Make sure no work handler is accessing the device */
3155 	flush_work(&vi->config_work);
3156 
3157 	netif_tx_lock_bh(vi->dev);
3158 	netif_device_detach(vi->dev);
3159 	netif_tx_unlock_bh(vi->dev);
3160 	if (netif_running(vi->dev))
3161 		virtnet_close(vi->dev);
3162 }
3163 
3164 static int init_vqs(struct virtnet_info *vi);
3165 
3166 static int virtnet_restore_up(struct virtio_device *vdev)
3167 {
3168 	struct virtnet_info *vi = vdev->priv;
3169 	int err;
3170 
3171 	err = init_vqs(vi);
3172 	if (err)
3173 		return err;
3174 
3175 	virtio_device_ready(vdev);
3176 
3177 	enable_delayed_refill(vi);
3178 
3179 	if (netif_running(vi->dev)) {
3180 		err = virtnet_open(vi->dev);
3181 		if (err)
3182 			return err;
3183 	}
3184 
3185 	netif_tx_lock_bh(vi->dev);
3186 	netif_device_attach(vi->dev);
3187 	netif_tx_unlock_bh(vi->dev);
3188 	return err;
3189 }
3190 
3191 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
3192 {
3193 	struct scatterlist sg;
3194 	vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
3195 
3196 	sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
3197 
3198 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
3199 				  VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
3200 		dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
3201 		return -EINVAL;
3202 	}
3203 
3204 	return 0;
3205 }
3206 
3207 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
3208 {
3209 	u64 offloads = 0;
3210 
3211 	if (!vi->guest_offloads)
3212 		return 0;
3213 
3214 	return virtnet_set_guest_offloads(vi, offloads);
3215 }
3216 
3217 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
3218 {
3219 	u64 offloads = vi->guest_offloads;
3220 
3221 	if (!vi->guest_offloads)
3222 		return 0;
3223 
3224 	return virtnet_set_guest_offloads(vi, offloads);
3225 }
3226 
3227 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
3228 			   struct netlink_ext_ack *extack)
3229 {
3230 	unsigned int room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM +
3231 					   sizeof(struct skb_shared_info));
3232 	unsigned int max_sz = PAGE_SIZE - room - ETH_HLEN;
3233 	struct virtnet_info *vi = netdev_priv(dev);
3234 	struct bpf_prog *old_prog;
3235 	u16 xdp_qp = 0, curr_qp;
3236 	int i, err;
3237 
3238 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
3239 	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3240 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3241 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3242 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3243 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM) ||
3244 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) ||
3245 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6))) {
3246 		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
3247 		return -EOPNOTSUPP;
3248 	}
3249 
3250 	if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
3251 		NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
3252 		return -EINVAL;
3253 	}
3254 
3255 	if (prog && !prog->aux->xdp_has_frags && dev->mtu > max_sz) {
3256 		NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP without frags");
3257 		netdev_warn(dev, "single-buffer XDP requires MTU less than %u\n", max_sz);
3258 		return -EINVAL;
3259 	}
3260 
3261 	curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
3262 	if (prog)
3263 		xdp_qp = nr_cpu_ids;
3264 
3265 	/* XDP requires extra queues for XDP_TX */
3266 	if (curr_qp + xdp_qp > vi->max_queue_pairs) {
3267 		netdev_warn_once(dev, "XDP request %i queues but max is %i. XDP_TX and XDP_REDIRECT will operate in a slower locked tx mode.\n",
3268 				 curr_qp + xdp_qp, vi->max_queue_pairs);
3269 		xdp_qp = 0;
3270 	}
3271 
3272 	old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
3273 	if (!prog && !old_prog)
3274 		return 0;
3275 
3276 	if (prog)
3277 		bpf_prog_add(prog, vi->max_queue_pairs - 1);
3278 
3279 	/* Make sure NAPI is not using any XDP TX queues for RX. */
3280 	if (netif_running(dev)) {
3281 		for (i = 0; i < vi->max_queue_pairs; i++) {
3282 			napi_disable(&vi->rq[i].napi);
3283 			virtnet_napi_tx_disable(&vi->sq[i].napi);
3284 		}
3285 	}
3286 
3287 	if (!prog) {
3288 		for (i = 0; i < vi->max_queue_pairs; i++) {
3289 			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3290 			if (i == 0)
3291 				virtnet_restore_guest_offloads(vi);
3292 		}
3293 		synchronize_net();
3294 	}
3295 
3296 	err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
3297 	if (err)
3298 		goto err;
3299 	netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
3300 	vi->xdp_queue_pairs = xdp_qp;
3301 
3302 	if (prog) {
3303 		vi->xdp_enabled = true;
3304 		for (i = 0; i < vi->max_queue_pairs; i++) {
3305 			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3306 			if (i == 0 && !old_prog)
3307 				virtnet_clear_guest_offloads(vi);
3308 		}
3309 		if (!old_prog)
3310 			xdp_features_set_redirect_target(dev, true);
3311 	} else {
3312 		xdp_features_clear_redirect_target(dev);
3313 		vi->xdp_enabled = false;
3314 	}
3315 
3316 	for (i = 0; i < vi->max_queue_pairs; i++) {
3317 		if (old_prog)
3318 			bpf_prog_put(old_prog);
3319 		if (netif_running(dev)) {
3320 			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3321 			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3322 					       &vi->sq[i].napi);
3323 		}
3324 	}
3325 
3326 	return 0;
3327 
3328 err:
3329 	if (!prog) {
3330 		virtnet_clear_guest_offloads(vi);
3331 		for (i = 0; i < vi->max_queue_pairs; i++)
3332 			rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
3333 	}
3334 
3335 	if (netif_running(dev)) {
3336 		for (i = 0; i < vi->max_queue_pairs; i++) {
3337 			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3338 			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3339 					       &vi->sq[i].napi);
3340 		}
3341 	}
3342 	if (prog)
3343 		bpf_prog_sub(prog, vi->max_queue_pairs - 1);
3344 	return err;
3345 }
3346 
3347 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
3348 {
3349 	switch (xdp->command) {
3350 	case XDP_SETUP_PROG:
3351 		return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
3352 	default:
3353 		return -EINVAL;
3354 	}
3355 }
3356 
3357 static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
3358 				      size_t len)
3359 {
3360 	struct virtnet_info *vi = netdev_priv(dev);
3361 	int ret;
3362 
3363 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
3364 		return -EOPNOTSUPP;
3365 
3366 	ret = snprintf(buf, len, "sby");
3367 	if (ret >= len)
3368 		return -EOPNOTSUPP;
3369 
3370 	return 0;
3371 }
3372 
3373 static int virtnet_set_features(struct net_device *dev,
3374 				netdev_features_t features)
3375 {
3376 	struct virtnet_info *vi = netdev_priv(dev);
3377 	u64 offloads;
3378 	int err;
3379 
3380 	if ((dev->features ^ features) & NETIF_F_GRO_HW) {
3381 		if (vi->xdp_enabled)
3382 			return -EBUSY;
3383 
3384 		if (features & NETIF_F_GRO_HW)
3385 			offloads = vi->guest_offloads_capable;
3386 		else
3387 			offloads = vi->guest_offloads_capable &
3388 				   ~GUEST_OFFLOAD_GRO_HW_MASK;
3389 
3390 		err = virtnet_set_guest_offloads(vi, offloads);
3391 		if (err)
3392 			return err;
3393 		vi->guest_offloads = offloads;
3394 	}
3395 
3396 	if ((dev->features ^ features) & NETIF_F_RXHASH) {
3397 		if (features & NETIF_F_RXHASH)
3398 			vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
3399 		else
3400 			vi->ctrl->rss.hash_types = VIRTIO_NET_HASH_REPORT_NONE;
3401 
3402 		if (!virtnet_commit_rss_command(vi))
3403 			return -EINVAL;
3404 	}
3405 
3406 	return 0;
3407 }
3408 
3409 static void virtnet_tx_timeout(struct net_device *dev, unsigned int txqueue)
3410 {
3411 	struct virtnet_info *priv = netdev_priv(dev);
3412 	struct send_queue *sq = &priv->sq[txqueue];
3413 	struct netdev_queue *txq = netdev_get_tx_queue(dev, txqueue);
3414 
3415 	u64_stats_update_begin(&sq->stats.syncp);
3416 	sq->stats.tx_timeouts++;
3417 	u64_stats_update_end(&sq->stats.syncp);
3418 
3419 	netdev_err(dev, "TX timeout on queue: %u, sq: %s, vq: 0x%x, name: %s, %u usecs ago\n",
3420 		   txqueue, sq->name, sq->vq->index, sq->vq->name,
3421 		   jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start)));
3422 }
3423 
3424 static const struct net_device_ops virtnet_netdev = {
3425 	.ndo_open            = virtnet_open,
3426 	.ndo_stop   	     = virtnet_close,
3427 	.ndo_start_xmit      = start_xmit,
3428 	.ndo_validate_addr   = eth_validate_addr,
3429 	.ndo_set_mac_address = virtnet_set_mac_address,
3430 	.ndo_set_rx_mode     = virtnet_set_rx_mode,
3431 	.ndo_get_stats64     = virtnet_stats,
3432 	.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
3433 	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
3434 	.ndo_bpf		= virtnet_xdp,
3435 	.ndo_xdp_xmit		= virtnet_xdp_xmit,
3436 	.ndo_features_check	= passthru_features_check,
3437 	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,
3438 	.ndo_set_features	= virtnet_set_features,
3439 	.ndo_tx_timeout		= virtnet_tx_timeout,
3440 };
3441 
3442 static void virtnet_config_changed_work(struct work_struct *work)
3443 {
3444 	struct virtnet_info *vi =
3445 		container_of(work, struct virtnet_info, config_work);
3446 	u16 v;
3447 
3448 	if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
3449 				 struct virtio_net_config, status, &v) < 0)
3450 		return;
3451 
3452 	if (v & VIRTIO_NET_S_ANNOUNCE) {
3453 		netdev_notify_peers(vi->dev);
3454 		virtnet_ack_link_announce(vi);
3455 	}
3456 
3457 	/* Ignore unknown (future) status bits */
3458 	v &= VIRTIO_NET_S_LINK_UP;
3459 
3460 	if (vi->status == v)
3461 		return;
3462 
3463 	vi->status = v;
3464 
3465 	if (vi->status & VIRTIO_NET_S_LINK_UP) {
3466 		virtnet_update_settings(vi);
3467 		netif_carrier_on(vi->dev);
3468 		netif_tx_wake_all_queues(vi->dev);
3469 	} else {
3470 		netif_carrier_off(vi->dev);
3471 		netif_tx_stop_all_queues(vi->dev);
3472 	}
3473 }
3474 
3475 static void virtnet_config_changed(struct virtio_device *vdev)
3476 {
3477 	struct virtnet_info *vi = vdev->priv;
3478 
3479 	schedule_work(&vi->config_work);
3480 }
3481 
3482 static void virtnet_free_queues(struct virtnet_info *vi)
3483 {
3484 	int i;
3485 
3486 	for (i = 0; i < vi->max_queue_pairs; i++) {
3487 		__netif_napi_del(&vi->rq[i].napi);
3488 		__netif_napi_del(&vi->sq[i].napi);
3489 	}
3490 
3491 	/* We called __netif_napi_del(),
3492 	 * we need to respect an RCU grace period before freeing vi->rq
3493 	 */
3494 	synchronize_net();
3495 
3496 	kfree(vi->rq);
3497 	kfree(vi->sq);
3498 	kfree(vi->ctrl);
3499 }
3500 
3501 static void _free_receive_bufs(struct virtnet_info *vi)
3502 {
3503 	struct bpf_prog *old_prog;
3504 	int i;
3505 
3506 	for (i = 0; i < vi->max_queue_pairs; i++) {
3507 		while (vi->rq[i].pages)
3508 			__free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
3509 
3510 		old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
3511 		RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
3512 		if (old_prog)
3513 			bpf_prog_put(old_prog);
3514 	}
3515 }
3516 
3517 static void free_receive_bufs(struct virtnet_info *vi)
3518 {
3519 	rtnl_lock();
3520 	_free_receive_bufs(vi);
3521 	rtnl_unlock();
3522 }
3523 
3524 static void free_receive_page_frags(struct virtnet_info *vi)
3525 {
3526 	int i;
3527 	for (i = 0; i < vi->max_queue_pairs; i++)
3528 		if (vi->rq[i].alloc_frag.page)
3529 			put_page(vi->rq[i].alloc_frag.page);
3530 }
3531 
3532 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
3533 {
3534 	if (!is_xdp_frame(buf))
3535 		dev_kfree_skb(buf);
3536 	else
3537 		xdp_return_frame(ptr_to_xdp(buf));
3538 }
3539 
3540 static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf)
3541 {
3542 	struct virtnet_info *vi = vq->vdev->priv;
3543 	int i = vq2rxq(vq);
3544 
3545 	if (vi->mergeable_rx_bufs)
3546 		put_page(virt_to_head_page(buf));
3547 	else if (vi->big_packets)
3548 		give_pages(&vi->rq[i], buf);
3549 	else
3550 		put_page(virt_to_head_page(buf));
3551 }
3552 
3553 static void free_unused_bufs(struct virtnet_info *vi)
3554 {
3555 	void *buf;
3556 	int i;
3557 
3558 	for (i = 0; i < vi->max_queue_pairs; i++) {
3559 		struct virtqueue *vq = vi->sq[i].vq;
3560 		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3561 			virtnet_sq_free_unused_buf(vq, buf);
3562 	}
3563 
3564 	for (i = 0; i < vi->max_queue_pairs; i++) {
3565 		struct virtqueue *vq = vi->rq[i].vq;
3566 		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3567 			virtnet_rq_free_unused_buf(vq, buf);
3568 	}
3569 }
3570 
3571 static void virtnet_del_vqs(struct virtnet_info *vi)
3572 {
3573 	struct virtio_device *vdev = vi->vdev;
3574 
3575 	virtnet_clean_affinity(vi);
3576 
3577 	vdev->config->del_vqs(vdev);
3578 
3579 	virtnet_free_queues(vi);
3580 }
3581 
3582 /* How large should a single buffer be so a queue full of these can fit at
3583  * least one full packet?
3584  * Logic below assumes the mergeable buffer header is used.
3585  */
3586 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
3587 {
3588 	const unsigned int hdr_len = vi->hdr_len;
3589 	unsigned int rq_size = virtqueue_get_vring_size(vq);
3590 	unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
3591 	unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
3592 	unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
3593 
3594 	return max(max(min_buf_len, hdr_len) - hdr_len,
3595 		   (unsigned int)GOOD_PACKET_LEN);
3596 }
3597 
3598 static int virtnet_find_vqs(struct virtnet_info *vi)
3599 {
3600 	vq_callback_t **callbacks;
3601 	struct virtqueue **vqs;
3602 	int ret = -ENOMEM;
3603 	int i, total_vqs;
3604 	const char **names;
3605 	bool *ctx;
3606 
3607 	/* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
3608 	 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
3609 	 * possible control vq.
3610 	 */
3611 	total_vqs = vi->max_queue_pairs * 2 +
3612 		    virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
3613 
3614 	/* Allocate space for find_vqs parameters */
3615 	vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
3616 	if (!vqs)
3617 		goto err_vq;
3618 	callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
3619 	if (!callbacks)
3620 		goto err_callback;
3621 	names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
3622 	if (!names)
3623 		goto err_names;
3624 	if (!vi->big_packets || vi->mergeable_rx_bufs) {
3625 		ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
3626 		if (!ctx)
3627 			goto err_ctx;
3628 	} else {
3629 		ctx = NULL;
3630 	}
3631 
3632 	/* Parameters for control virtqueue, if any */
3633 	if (vi->has_cvq) {
3634 		callbacks[total_vqs - 1] = NULL;
3635 		names[total_vqs - 1] = "control";
3636 	}
3637 
3638 	/* Allocate/initialize parameters for send/receive virtqueues */
3639 	for (i = 0; i < vi->max_queue_pairs; i++) {
3640 		callbacks[rxq2vq(i)] = skb_recv_done;
3641 		callbacks[txq2vq(i)] = skb_xmit_done;
3642 		sprintf(vi->rq[i].name, "input.%d", i);
3643 		sprintf(vi->sq[i].name, "output.%d", i);
3644 		names[rxq2vq(i)] = vi->rq[i].name;
3645 		names[txq2vq(i)] = vi->sq[i].name;
3646 		if (ctx)
3647 			ctx[rxq2vq(i)] = true;
3648 	}
3649 
3650 	ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
3651 				  names, ctx, NULL);
3652 	if (ret)
3653 		goto err_find;
3654 
3655 	if (vi->has_cvq) {
3656 		vi->cvq = vqs[total_vqs - 1];
3657 		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
3658 			vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
3659 	}
3660 
3661 	for (i = 0; i < vi->max_queue_pairs; i++) {
3662 		vi->rq[i].vq = vqs[rxq2vq(i)];
3663 		vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
3664 		vi->sq[i].vq = vqs[txq2vq(i)];
3665 	}
3666 
3667 	/* run here: ret == 0. */
3668 
3669 
3670 err_find:
3671 	kfree(ctx);
3672 err_ctx:
3673 	kfree(names);
3674 err_names:
3675 	kfree(callbacks);
3676 err_callback:
3677 	kfree(vqs);
3678 err_vq:
3679 	return ret;
3680 }
3681 
3682 static int virtnet_alloc_queues(struct virtnet_info *vi)
3683 {
3684 	int i;
3685 
3686 	if (vi->has_cvq) {
3687 		vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
3688 		if (!vi->ctrl)
3689 			goto err_ctrl;
3690 	} else {
3691 		vi->ctrl = NULL;
3692 	}
3693 	vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
3694 	if (!vi->sq)
3695 		goto err_sq;
3696 	vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
3697 	if (!vi->rq)
3698 		goto err_rq;
3699 
3700 	INIT_DELAYED_WORK(&vi->refill, refill_work);
3701 	for (i = 0; i < vi->max_queue_pairs; i++) {
3702 		vi->rq[i].pages = NULL;
3703 		netif_napi_add_weight(vi->dev, &vi->rq[i].napi, virtnet_poll,
3704 				      napi_weight);
3705 		netif_napi_add_tx_weight(vi->dev, &vi->sq[i].napi,
3706 					 virtnet_poll_tx,
3707 					 napi_tx ? napi_weight : 0);
3708 
3709 		sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
3710 		ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
3711 		sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
3712 
3713 		u64_stats_init(&vi->rq[i].stats.syncp);
3714 		u64_stats_init(&vi->sq[i].stats.syncp);
3715 	}
3716 
3717 	return 0;
3718 
3719 err_rq:
3720 	kfree(vi->sq);
3721 err_sq:
3722 	kfree(vi->ctrl);
3723 err_ctrl:
3724 	return -ENOMEM;
3725 }
3726 
3727 static int init_vqs(struct virtnet_info *vi)
3728 {
3729 	int ret;
3730 
3731 	/* Allocate send & receive queues */
3732 	ret = virtnet_alloc_queues(vi);
3733 	if (ret)
3734 		goto err;
3735 
3736 	ret = virtnet_find_vqs(vi);
3737 	if (ret)
3738 		goto err_free;
3739 
3740 	cpus_read_lock();
3741 	virtnet_set_affinity(vi);
3742 	cpus_read_unlock();
3743 
3744 	return 0;
3745 
3746 err_free:
3747 	virtnet_free_queues(vi);
3748 err:
3749 	return ret;
3750 }
3751 
3752 #ifdef CONFIG_SYSFS
3753 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
3754 		char *buf)
3755 {
3756 	struct virtnet_info *vi = netdev_priv(queue->dev);
3757 	unsigned int queue_index = get_netdev_rx_queue_index(queue);
3758 	unsigned int headroom = virtnet_get_headroom(vi);
3759 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
3760 	struct ewma_pkt_len *avg;
3761 
3762 	BUG_ON(queue_index >= vi->max_queue_pairs);
3763 	avg = &vi->rq[queue_index].mrg_avg_pkt_len;
3764 	return sprintf(buf, "%u\n",
3765 		       get_mergeable_buf_len(&vi->rq[queue_index], avg,
3766 				       SKB_DATA_ALIGN(headroom + tailroom)));
3767 }
3768 
3769 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
3770 	__ATTR_RO(mergeable_rx_buffer_size);
3771 
3772 static struct attribute *virtio_net_mrg_rx_attrs[] = {
3773 	&mergeable_rx_buffer_size_attribute.attr,
3774 	NULL
3775 };
3776 
3777 static const struct attribute_group virtio_net_mrg_rx_group = {
3778 	.name = "virtio_net",
3779 	.attrs = virtio_net_mrg_rx_attrs
3780 };
3781 #endif
3782 
3783 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
3784 				    unsigned int fbit,
3785 				    const char *fname, const char *dname)
3786 {
3787 	if (!virtio_has_feature(vdev, fbit))
3788 		return false;
3789 
3790 	dev_err(&vdev->dev, "device advertises feature %s but not %s",
3791 		fname, dname);
3792 
3793 	return true;
3794 }
3795 
3796 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)			\
3797 	virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
3798 
3799 static bool virtnet_validate_features(struct virtio_device *vdev)
3800 {
3801 	if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
3802 	    (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
3803 			     "VIRTIO_NET_F_CTRL_VQ") ||
3804 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
3805 			     "VIRTIO_NET_F_CTRL_VQ") ||
3806 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
3807 			     "VIRTIO_NET_F_CTRL_VQ") ||
3808 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
3809 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
3810 			     "VIRTIO_NET_F_CTRL_VQ") ||
3811 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS,
3812 			     "VIRTIO_NET_F_CTRL_VQ") ||
3813 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_HASH_REPORT,
3814 			     "VIRTIO_NET_F_CTRL_VQ") ||
3815 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_NOTF_COAL,
3816 			     "VIRTIO_NET_F_CTRL_VQ"))) {
3817 		return false;
3818 	}
3819 
3820 	return true;
3821 }
3822 
3823 #define MIN_MTU ETH_MIN_MTU
3824 #define MAX_MTU ETH_MAX_MTU
3825 
3826 static int virtnet_validate(struct virtio_device *vdev)
3827 {
3828 	if (!vdev->config->get) {
3829 		dev_err(&vdev->dev, "%s failure: config access disabled\n",
3830 			__func__);
3831 		return -EINVAL;
3832 	}
3833 
3834 	if (!virtnet_validate_features(vdev))
3835 		return -EINVAL;
3836 
3837 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3838 		int mtu = virtio_cread16(vdev,
3839 					 offsetof(struct virtio_net_config,
3840 						  mtu));
3841 		if (mtu < MIN_MTU)
3842 			__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
3843 	}
3844 
3845 	if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY) &&
3846 	    !virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
3847 		dev_warn(&vdev->dev, "device advertises feature VIRTIO_NET_F_STANDBY but not VIRTIO_NET_F_MAC, disabling standby");
3848 		__virtio_clear_bit(vdev, VIRTIO_NET_F_STANDBY);
3849 	}
3850 
3851 	return 0;
3852 }
3853 
3854 static bool virtnet_check_guest_gso(const struct virtnet_info *vi)
3855 {
3856 	return virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3857 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3858 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3859 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3860 		(virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) &&
3861 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6));
3862 }
3863 
3864 static void virtnet_set_big_packets(struct virtnet_info *vi, const int mtu)
3865 {
3866 	bool guest_gso = virtnet_check_guest_gso(vi);
3867 
3868 	/* If device can receive ANY guest GSO packets, regardless of mtu,
3869 	 * allocate packets of maximum size, otherwise limit it to only
3870 	 * mtu size worth only.
3871 	 */
3872 	if (mtu > ETH_DATA_LEN || guest_gso) {
3873 		vi->big_packets = true;
3874 		vi->big_packets_num_skbfrags = guest_gso ? MAX_SKB_FRAGS : DIV_ROUND_UP(mtu, PAGE_SIZE);
3875 	}
3876 }
3877 
3878 static int virtnet_probe(struct virtio_device *vdev)
3879 {
3880 	int i, err = -ENOMEM;
3881 	struct net_device *dev;
3882 	struct virtnet_info *vi;
3883 	u16 max_queue_pairs;
3884 	int mtu = 0;
3885 
3886 	/* Find if host supports multiqueue/rss virtio_net device */
3887 	max_queue_pairs = 1;
3888 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MQ) || virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
3889 		max_queue_pairs =
3890 		     virtio_cread16(vdev, offsetof(struct virtio_net_config, max_virtqueue_pairs));
3891 
3892 	/* We need at least 2 queue's */
3893 	if (max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
3894 	    max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
3895 	    !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3896 		max_queue_pairs = 1;
3897 
3898 	/* Allocate ourselves a network device with room for our info */
3899 	dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
3900 	if (!dev)
3901 		return -ENOMEM;
3902 
3903 	/* Set up network device as normal. */
3904 	dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE |
3905 			   IFF_TX_SKB_NO_LINEAR;
3906 	dev->netdev_ops = &virtnet_netdev;
3907 	dev->features = NETIF_F_HIGHDMA;
3908 
3909 	dev->ethtool_ops = &virtnet_ethtool_ops;
3910 	SET_NETDEV_DEV(dev, &vdev->dev);
3911 
3912 	/* Do we support "hardware" checksums? */
3913 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
3914 		/* This opens up the world of extra features. */
3915 		dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3916 		if (csum)
3917 			dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3918 
3919 		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
3920 			dev->hw_features |= NETIF_F_TSO
3921 				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
3922 		}
3923 		/* Individual feature bits: what can host handle? */
3924 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
3925 			dev->hw_features |= NETIF_F_TSO;
3926 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3927 			dev->hw_features |= NETIF_F_TSO6;
3928 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3929 			dev->hw_features |= NETIF_F_TSO_ECN;
3930 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_USO))
3931 			dev->hw_features |= NETIF_F_GSO_UDP_L4;
3932 
3933 		dev->features |= NETIF_F_GSO_ROBUST;
3934 
3935 		if (gso)
3936 			dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3937 		/* (!csum && gso) case will be fixed by register_netdev() */
3938 	}
3939 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3940 		dev->features |= NETIF_F_RXCSUM;
3941 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3942 	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3943 		dev->features |= NETIF_F_GRO_HW;
3944 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3945 		dev->hw_features |= NETIF_F_GRO_HW;
3946 
3947 	dev->vlan_features = dev->features;
3948 	dev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT;
3949 
3950 	/* MTU range: 68 - 65535 */
3951 	dev->min_mtu = MIN_MTU;
3952 	dev->max_mtu = MAX_MTU;
3953 
3954 	/* Configuration may specify what MAC to use.  Otherwise random. */
3955 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
3956 		u8 addr[ETH_ALEN];
3957 
3958 		virtio_cread_bytes(vdev,
3959 				   offsetof(struct virtio_net_config, mac),
3960 				   addr, ETH_ALEN);
3961 		eth_hw_addr_set(dev, addr);
3962 	} else {
3963 		eth_hw_addr_random(dev);
3964 		dev_info(&vdev->dev, "Assigned random MAC address %pM\n",
3965 			 dev->dev_addr);
3966 	}
3967 
3968 	/* Set up our device-specific information */
3969 	vi = netdev_priv(dev);
3970 	vi->dev = dev;
3971 	vi->vdev = vdev;
3972 	vdev->priv = vi;
3973 
3974 	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3975 	spin_lock_init(&vi->refill_lock);
3976 
3977 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) {
3978 		vi->mergeable_rx_bufs = true;
3979 		dev->xdp_features |= NETDEV_XDP_ACT_RX_SG;
3980 	}
3981 
3982 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
3983 		vi->rx_usecs = 0;
3984 		vi->tx_usecs = 0;
3985 		vi->tx_max_packets = 0;
3986 		vi->rx_max_packets = 0;
3987 	}
3988 
3989 	if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
3990 		vi->has_rss_hash_report = true;
3991 
3992 	if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
3993 		vi->has_rss = true;
3994 
3995 	if (vi->has_rss || vi->has_rss_hash_report) {
3996 		vi->rss_indir_table_size =
3997 			virtio_cread16(vdev, offsetof(struct virtio_net_config,
3998 				rss_max_indirection_table_length));
3999 		vi->rss_key_size =
4000 			virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
4001 
4002 		vi->rss_hash_types_supported =
4003 		    virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
4004 		vi->rss_hash_types_supported &=
4005 				~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
4006 				  VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
4007 				  VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);
4008 
4009 		dev->hw_features |= NETIF_F_RXHASH;
4010 	}
4011 
4012 	if (vi->has_rss_hash_report)
4013 		vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash);
4014 	else if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
4015 		 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
4016 		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
4017 	else
4018 		vi->hdr_len = sizeof(struct virtio_net_hdr);
4019 
4020 	if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
4021 	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
4022 		vi->any_header_sg = true;
4023 
4024 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
4025 		vi->has_cvq = true;
4026 
4027 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
4028 		mtu = virtio_cread16(vdev,
4029 				     offsetof(struct virtio_net_config,
4030 					      mtu));
4031 		if (mtu < dev->min_mtu) {
4032 			/* Should never trigger: MTU was previously validated
4033 			 * in virtnet_validate.
4034 			 */
4035 			dev_err(&vdev->dev,
4036 				"device MTU appears to have changed it is now %d < %d",
4037 				mtu, dev->min_mtu);
4038 			err = -EINVAL;
4039 			goto free;
4040 		}
4041 
4042 		dev->mtu = mtu;
4043 		dev->max_mtu = mtu;
4044 	}
4045 
4046 	virtnet_set_big_packets(vi, mtu);
4047 
4048 	if (vi->any_header_sg)
4049 		dev->needed_headroom = vi->hdr_len;
4050 
4051 	/* Enable multiqueue by default */
4052 	if (num_online_cpus() >= max_queue_pairs)
4053 		vi->curr_queue_pairs = max_queue_pairs;
4054 	else
4055 		vi->curr_queue_pairs = num_online_cpus();
4056 	vi->max_queue_pairs = max_queue_pairs;
4057 
4058 	/* Allocate/initialize the rx/tx queues, and invoke find_vqs */
4059 	err = init_vqs(vi);
4060 	if (err)
4061 		goto free;
4062 
4063 #ifdef CONFIG_SYSFS
4064 	if (vi->mergeable_rx_bufs)
4065 		dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
4066 #endif
4067 	netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
4068 	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
4069 
4070 	virtnet_init_settings(dev);
4071 
4072 	if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
4073 		vi->failover = net_failover_create(vi->dev);
4074 		if (IS_ERR(vi->failover)) {
4075 			err = PTR_ERR(vi->failover);
4076 			goto free_vqs;
4077 		}
4078 	}
4079 
4080 	if (vi->has_rss || vi->has_rss_hash_report)
4081 		virtnet_init_default_rss(vi);
4082 
4083 	/* serialize netdev register + virtio_device_ready() with ndo_open() */
4084 	rtnl_lock();
4085 
4086 	err = register_netdevice(dev);
4087 	if (err) {
4088 		pr_debug("virtio_net: registering device failed\n");
4089 		rtnl_unlock();
4090 		goto free_failover;
4091 	}
4092 
4093 	virtio_device_ready(vdev);
4094 
4095 	/* a random MAC address has been assigned, notify the device.
4096 	 * We don't fail probe if VIRTIO_NET_F_CTRL_MAC_ADDR is not there
4097 	 * because many devices work fine without getting MAC explicitly
4098 	 */
4099 	if (!virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
4100 	    virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
4101 		struct scatterlist sg;
4102 
4103 		sg_init_one(&sg, dev->dev_addr, dev->addr_len);
4104 		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
4105 					  VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
4106 			pr_debug("virtio_net: setting MAC address failed\n");
4107 			rtnl_unlock();
4108 			err = -EINVAL;
4109 			goto free_unregister_netdev;
4110 		}
4111 	}
4112 
4113 	rtnl_unlock();
4114 
4115 	err = virtnet_cpu_notif_add(vi);
4116 	if (err) {
4117 		pr_debug("virtio_net: registering cpu notifier failed\n");
4118 		goto free_unregister_netdev;
4119 	}
4120 
4121 	virtnet_set_queues(vi, vi->curr_queue_pairs);
4122 
4123 	/* Assume link up if device can't report link status,
4124 	   otherwise get link status from config. */
4125 	netif_carrier_off(dev);
4126 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
4127 		schedule_work(&vi->config_work);
4128 	} else {
4129 		vi->status = VIRTIO_NET_S_LINK_UP;
4130 		virtnet_update_settings(vi);
4131 		netif_carrier_on(dev);
4132 	}
4133 
4134 	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
4135 		if (virtio_has_feature(vi->vdev, guest_offloads[i]))
4136 			set_bit(guest_offloads[i], &vi->guest_offloads);
4137 	vi->guest_offloads_capable = vi->guest_offloads;
4138 
4139 	pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
4140 		 dev->name, max_queue_pairs);
4141 
4142 	return 0;
4143 
4144 free_unregister_netdev:
4145 	unregister_netdev(dev);
4146 free_failover:
4147 	net_failover_destroy(vi->failover);
4148 free_vqs:
4149 	virtio_reset_device(vdev);
4150 	cancel_delayed_work_sync(&vi->refill);
4151 	free_receive_page_frags(vi);
4152 	virtnet_del_vqs(vi);
4153 free:
4154 	free_netdev(dev);
4155 	return err;
4156 }
4157 
4158 static void remove_vq_common(struct virtnet_info *vi)
4159 {
4160 	virtio_reset_device(vi->vdev);
4161 
4162 	/* Free unused buffers in both send and recv, if any. */
4163 	free_unused_bufs(vi);
4164 
4165 	free_receive_bufs(vi);
4166 
4167 	free_receive_page_frags(vi);
4168 
4169 	virtnet_del_vqs(vi);
4170 }
4171 
4172 static void virtnet_remove(struct virtio_device *vdev)
4173 {
4174 	struct virtnet_info *vi = vdev->priv;
4175 
4176 	virtnet_cpu_notif_remove(vi);
4177 
4178 	/* Make sure no work handler is accessing the device. */
4179 	flush_work(&vi->config_work);
4180 
4181 	unregister_netdev(vi->dev);
4182 
4183 	net_failover_destroy(vi->failover);
4184 
4185 	remove_vq_common(vi);
4186 
4187 	free_netdev(vi->dev);
4188 }
4189 
4190 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
4191 {
4192 	struct virtnet_info *vi = vdev->priv;
4193 
4194 	virtnet_cpu_notif_remove(vi);
4195 	virtnet_freeze_down(vdev);
4196 	remove_vq_common(vi);
4197 
4198 	return 0;
4199 }
4200 
4201 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
4202 {
4203 	struct virtnet_info *vi = vdev->priv;
4204 	int err;
4205 
4206 	err = virtnet_restore_up(vdev);
4207 	if (err)
4208 		return err;
4209 	virtnet_set_queues(vi, vi->curr_queue_pairs);
4210 
4211 	err = virtnet_cpu_notif_add(vi);
4212 	if (err) {
4213 		virtnet_freeze_down(vdev);
4214 		remove_vq_common(vi);
4215 		return err;
4216 	}
4217 
4218 	return 0;
4219 }
4220 
4221 static struct virtio_device_id id_table[] = {
4222 	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
4223 	{ 0 },
4224 };
4225 
4226 #define VIRTNET_FEATURES \
4227 	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
4228 	VIRTIO_NET_F_MAC, \
4229 	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
4230 	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
4231 	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
4232 	VIRTIO_NET_F_HOST_USO, VIRTIO_NET_F_GUEST_USO4, VIRTIO_NET_F_GUEST_USO6, \
4233 	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
4234 	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
4235 	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
4236 	VIRTIO_NET_F_CTRL_MAC_ADDR, \
4237 	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
4238 	VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \
4239 	VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_NOTF_COAL
4240 
4241 static unsigned int features[] = {
4242 	VIRTNET_FEATURES,
4243 };
4244 
4245 static unsigned int features_legacy[] = {
4246 	VIRTNET_FEATURES,
4247 	VIRTIO_NET_F_GSO,
4248 	VIRTIO_F_ANY_LAYOUT,
4249 };
4250 
4251 static struct virtio_driver virtio_net_driver = {
4252 	.feature_table = features,
4253 	.feature_table_size = ARRAY_SIZE(features),
4254 	.feature_table_legacy = features_legacy,
4255 	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
4256 	.driver.name =	KBUILD_MODNAME,
4257 	.driver.owner =	THIS_MODULE,
4258 	.id_table =	id_table,
4259 	.validate =	virtnet_validate,
4260 	.probe =	virtnet_probe,
4261 	.remove =	virtnet_remove,
4262 	.config_changed = virtnet_config_changed,
4263 #ifdef CONFIG_PM_SLEEP
4264 	.freeze =	virtnet_freeze,
4265 	.restore =	virtnet_restore,
4266 #endif
4267 };
4268 
4269 static __init int virtio_net_driver_init(void)
4270 {
4271 	int ret;
4272 
4273 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
4274 				      virtnet_cpu_online,
4275 				      virtnet_cpu_down_prep);
4276 	if (ret < 0)
4277 		goto out;
4278 	virtionet_online = ret;
4279 	ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
4280 				      NULL, virtnet_cpu_dead);
4281 	if (ret)
4282 		goto err_dead;
4283 	ret = register_virtio_driver(&virtio_net_driver);
4284 	if (ret)
4285 		goto err_virtio;
4286 	return 0;
4287 err_virtio:
4288 	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4289 err_dead:
4290 	cpuhp_remove_multi_state(virtionet_online);
4291 out:
4292 	return ret;
4293 }
4294 module_init(virtio_net_driver_init);
4295 
4296 static __exit void virtio_net_driver_exit(void)
4297 {
4298 	unregister_virtio_driver(&virtio_net_driver);
4299 	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4300 	cpuhp_remove_multi_state(virtionet_online);
4301 }
4302 module_exit(virtio_net_driver_exit);
4303 
4304 MODULE_DEVICE_TABLE(virtio, id_table);
4305 MODULE_DESCRIPTION("Virtio network driver");
4306 MODULE_LICENSE("GPL");
4307