xref: /openbmc/linux/drivers/net/virtio_net.c (revision bb2c1e9e)
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 	VIRTIO_NET_F_GUEST_HDRLEN
67 };
68 
69 #define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
70 				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
71 				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
72 				(1ULL << VIRTIO_NET_F_GUEST_UFO)  | \
73 				(1ULL << VIRTIO_NET_F_GUEST_USO4) | \
74 				(1ULL << VIRTIO_NET_F_GUEST_USO6))
75 
76 struct virtnet_stat_desc {
77 	char desc[ETH_GSTRING_LEN];
78 	size_t offset;
79 };
80 
81 struct virtnet_sq_stats {
82 	struct u64_stats_sync syncp;
83 	u64 packets;
84 	u64 bytes;
85 	u64 xdp_tx;
86 	u64 xdp_tx_drops;
87 	u64 kicks;
88 	u64 tx_timeouts;
89 };
90 
91 struct virtnet_rq_stats {
92 	struct u64_stats_sync syncp;
93 	u64 packets;
94 	u64 bytes;
95 	u64 drops;
96 	u64 xdp_packets;
97 	u64 xdp_tx;
98 	u64 xdp_redirects;
99 	u64 xdp_drops;
100 	u64 kicks;
101 };
102 
103 #define VIRTNET_SQ_STAT(m)	offsetof(struct virtnet_sq_stats, m)
104 #define VIRTNET_RQ_STAT(m)	offsetof(struct virtnet_rq_stats, m)
105 
106 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
107 	{ "packets",		VIRTNET_SQ_STAT(packets) },
108 	{ "bytes",		VIRTNET_SQ_STAT(bytes) },
109 	{ "xdp_tx",		VIRTNET_SQ_STAT(xdp_tx) },
110 	{ "xdp_tx_drops",	VIRTNET_SQ_STAT(xdp_tx_drops) },
111 	{ "kicks",		VIRTNET_SQ_STAT(kicks) },
112 	{ "tx_timeouts",	VIRTNET_SQ_STAT(tx_timeouts) },
113 };
114 
115 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
116 	{ "packets",		VIRTNET_RQ_STAT(packets) },
117 	{ "bytes",		VIRTNET_RQ_STAT(bytes) },
118 	{ "drops",		VIRTNET_RQ_STAT(drops) },
119 	{ "xdp_packets",	VIRTNET_RQ_STAT(xdp_packets) },
120 	{ "xdp_tx",		VIRTNET_RQ_STAT(xdp_tx) },
121 	{ "xdp_redirects",	VIRTNET_RQ_STAT(xdp_redirects) },
122 	{ "xdp_drops",		VIRTNET_RQ_STAT(xdp_drops) },
123 	{ "kicks",		VIRTNET_RQ_STAT(kicks) },
124 };
125 
126 #define VIRTNET_SQ_STATS_LEN	ARRAY_SIZE(virtnet_sq_stats_desc)
127 #define VIRTNET_RQ_STATS_LEN	ARRAY_SIZE(virtnet_rq_stats_desc)
128 
129 /* Internal representation of a send virtqueue */
130 struct send_queue {
131 	/* Virtqueue associated with this send _queue */
132 	struct virtqueue *vq;
133 
134 	/* TX: fragments + linear part + virtio header */
135 	struct scatterlist sg[MAX_SKB_FRAGS + 2];
136 
137 	/* Name of the send queue: output.$index */
138 	char name[16];
139 
140 	struct virtnet_sq_stats stats;
141 
142 	struct napi_struct napi;
143 
144 	/* Record whether sq is in reset state. */
145 	bool reset;
146 };
147 
148 /* Internal representation of a receive virtqueue */
149 struct receive_queue {
150 	/* Virtqueue associated with this receive_queue */
151 	struct virtqueue *vq;
152 
153 	struct napi_struct napi;
154 
155 	struct bpf_prog __rcu *xdp_prog;
156 
157 	struct virtnet_rq_stats stats;
158 
159 	/* Chain pages by the private ptr. */
160 	struct page *pages;
161 
162 	/* Average packet length for mergeable receive buffers. */
163 	struct ewma_pkt_len mrg_avg_pkt_len;
164 
165 	/* Page frag for packet buffer allocation. */
166 	struct page_frag alloc_frag;
167 
168 	/* RX: fragments + linear part + virtio header */
169 	struct scatterlist sg[MAX_SKB_FRAGS + 2];
170 
171 	/* Min single buffer size for mergeable buffers case. */
172 	unsigned int min_buf_len;
173 
174 	/* Name of this receive queue: input.$index */
175 	char name[16];
176 
177 	struct xdp_rxq_info xdp_rxq;
178 };
179 
180 /* This structure can contain rss message with maximum settings for indirection table and keysize
181  * Note, that default structure that describes RSS configuration virtio_net_rss_config
182  * contains same info but can't handle table values.
183  * In any case, structure would be passed to virtio hw through sg_buf split by parts
184  * because table sizes may be differ according to the device configuration.
185  */
186 #define VIRTIO_NET_RSS_MAX_KEY_SIZE     40
187 #define VIRTIO_NET_RSS_MAX_TABLE_LEN    128
188 struct virtio_net_ctrl_rss {
189 	u32 hash_types;
190 	u16 indirection_table_mask;
191 	u16 unclassified_queue;
192 	u16 indirection_table[VIRTIO_NET_RSS_MAX_TABLE_LEN];
193 	u16 max_tx_vq;
194 	u8 hash_key_length;
195 	u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];
196 };
197 
198 /* Control VQ buffers: protected by the rtnl lock */
199 struct control_buf {
200 	struct virtio_net_ctrl_hdr hdr;
201 	virtio_net_ctrl_ack status;
202 	struct virtio_net_ctrl_mq mq;
203 	u8 promisc;
204 	u8 allmulti;
205 	__virtio16 vid;
206 	__virtio64 offloads;
207 	struct virtio_net_ctrl_rss rss;
208 };
209 
210 struct virtnet_info {
211 	struct virtio_device *vdev;
212 	struct virtqueue *cvq;
213 	struct net_device *dev;
214 	struct send_queue *sq;
215 	struct receive_queue *rq;
216 	unsigned int status;
217 
218 	/* Max # of queue pairs supported by the device */
219 	u16 max_queue_pairs;
220 
221 	/* # of queue pairs currently used by the driver */
222 	u16 curr_queue_pairs;
223 
224 	/* # of XDP queue pairs currently used by the driver */
225 	u16 xdp_queue_pairs;
226 
227 	/* xdp_queue_pairs may be 0, when xdp is already loaded. So add this. */
228 	bool xdp_enabled;
229 
230 	/* I like... big packets and I cannot lie! */
231 	bool big_packets;
232 
233 	/* number of sg entries allocated for big packets */
234 	unsigned int big_packets_num_skbfrags;
235 
236 	/* Host will merge rx buffers for big packets (shake it! shake it!) */
237 	bool mergeable_rx_bufs;
238 
239 	/* Host supports rss and/or hash report */
240 	bool has_rss;
241 	bool has_rss_hash_report;
242 	u8 rss_key_size;
243 	u16 rss_indir_table_size;
244 	u32 rss_hash_types_supported;
245 	u32 rss_hash_types_saved;
246 
247 	/* Has control virtqueue */
248 	bool has_cvq;
249 
250 	/* Host can handle any s/g split between our header and packet data */
251 	bool any_header_sg;
252 
253 	/* Packet virtio header size */
254 	u8 hdr_len;
255 
256 	/* Work struct for delayed refilling if we run low on memory. */
257 	struct delayed_work refill;
258 
259 	/* Is delayed refill enabled? */
260 	bool refill_enabled;
261 
262 	/* The lock to synchronize the access to refill_enabled */
263 	spinlock_t refill_lock;
264 
265 	/* Work struct for config space updates */
266 	struct work_struct config_work;
267 
268 	/* Does the affinity hint is set for virtqueues? */
269 	bool affinity_hint_set;
270 
271 	/* CPU hotplug instances for online & dead */
272 	struct hlist_node node;
273 	struct hlist_node node_dead;
274 
275 	struct control_buf *ctrl;
276 
277 	/* Ethtool settings */
278 	u8 duplex;
279 	u32 speed;
280 
281 	/* Interrupt coalescing settings */
282 	u32 tx_usecs;
283 	u32 rx_usecs;
284 	u32 tx_max_packets;
285 	u32 rx_max_packets;
286 
287 	unsigned long guest_offloads;
288 	unsigned long guest_offloads_capable;
289 
290 	/* failover when STANDBY feature enabled */
291 	struct failover *failover;
292 };
293 
294 struct padded_vnet_hdr {
295 	struct virtio_net_hdr_v1_hash hdr;
296 	/*
297 	 * hdr is in a separate sg buffer, and data sg buffer shares same page
298 	 * with this header sg. This padding makes next sg 16 byte aligned
299 	 * after the header.
300 	 */
301 	char padding[12];
302 };
303 
304 static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
305 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
306 
307 static bool is_xdp_frame(void *ptr)
308 {
309 	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
310 }
311 
312 static void *xdp_to_ptr(struct xdp_frame *ptr)
313 {
314 	return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
315 }
316 
317 static struct xdp_frame *ptr_to_xdp(void *ptr)
318 {
319 	return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
320 }
321 
322 /* Converting between virtqueue no. and kernel tx/rx queue no.
323  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
324  */
325 static int vq2txq(struct virtqueue *vq)
326 {
327 	return (vq->index - 1) / 2;
328 }
329 
330 static int txq2vq(int txq)
331 {
332 	return txq * 2 + 1;
333 }
334 
335 static int vq2rxq(struct virtqueue *vq)
336 {
337 	return vq->index / 2;
338 }
339 
340 static int rxq2vq(int rxq)
341 {
342 	return rxq * 2;
343 }
344 
345 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
346 {
347 	return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
348 }
349 
350 /*
351  * private is used to chain pages for big packets, put the whole
352  * most recent used list in the beginning for reuse
353  */
354 static void give_pages(struct receive_queue *rq, struct page *page)
355 {
356 	struct page *end;
357 
358 	/* Find end of list, sew whole thing into vi->rq.pages. */
359 	for (end = page; end->private; end = (struct page *)end->private);
360 	end->private = (unsigned long)rq->pages;
361 	rq->pages = page;
362 }
363 
364 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
365 {
366 	struct page *p = rq->pages;
367 
368 	if (p) {
369 		rq->pages = (struct page *)p->private;
370 		/* clear private here, it is used to chain pages */
371 		p->private = 0;
372 	} else
373 		p = alloc_page(gfp_mask);
374 	return p;
375 }
376 
377 static void enable_delayed_refill(struct virtnet_info *vi)
378 {
379 	spin_lock_bh(&vi->refill_lock);
380 	vi->refill_enabled = true;
381 	spin_unlock_bh(&vi->refill_lock);
382 }
383 
384 static void disable_delayed_refill(struct virtnet_info *vi)
385 {
386 	spin_lock_bh(&vi->refill_lock);
387 	vi->refill_enabled = false;
388 	spin_unlock_bh(&vi->refill_lock);
389 }
390 
391 static void virtqueue_napi_schedule(struct napi_struct *napi,
392 				    struct virtqueue *vq)
393 {
394 	if (napi_schedule_prep(napi)) {
395 		virtqueue_disable_cb(vq);
396 		__napi_schedule(napi);
397 	}
398 }
399 
400 static void virtqueue_napi_complete(struct napi_struct *napi,
401 				    struct virtqueue *vq, int processed)
402 {
403 	int opaque;
404 
405 	opaque = virtqueue_enable_cb_prepare(vq);
406 	if (napi_complete_done(napi, processed)) {
407 		if (unlikely(virtqueue_poll(vq, opaque)))
408 			virtqueue_napi_schedule(napi, vq);
409 	} else {
410 		virtqueue_disable_cb(vq);
411 	}
412 }
413 
414 static void skb_xmit_done(struct virtqueue *vq)
415 {
416 	struct virtnet_info *vi = vq->vdev->priv;
417 	struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
418 
419 	/* Suppress further interrupts. */
420 	virtqueue_disable_cb(vq);
421 
422 	if (napi->weight)
423 		virtqueue_napi_schedule(napi, vq);
424 	else
425 		/* We were probably waiting for more output buffers. */
426 		netif_wake_subqueue(vi->dev, vq2txq(vq));
427 }
428 
429 #define MRG_CTX_HEADER_SHIFT 22
430 static void *mergeable_len_to_ctx(unsigned int truesize,
431 				  unsigned int headroom)
432 {
433 	return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
434 }
435 
436 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
437 {
438 	return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
439 }
440 
441 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
442 {
443 	return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
444 }
445 
446 /* Called from bottom half context */
447 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
448 				   struct receive_queue *rq,
449 				   struct page *page, unsigned int offset,
450 				   unsigned int len, unsigned int truesize,
451 				   unsigned int headroom)
452 {
453 	struct sk_buff *skb;
454 	struct virtio_net_hdr_mrg_rxbuf *hdr;
455 	unsigned int copy, hdr_len, hdr_padded_len;
456 	struct page *page_to_free = NULL;
457 	int tailroom, shinfo_size;
458 	char *p, *hdr_p, *buf;
459 
460 	p = page_address(page) + offset;
461 	hdr_p = p;
462 
463 	hdr_len = vi->hdr_len;
464 	if (vi->mergeable_rx_bufs)
465 		hdr_padded_len = hdr_len;
466 	else
467 		hdr_padded_len = sizeof(struct padded_vnet_hdr);
468 
469 	buf = p - headroom;
470 	len -= hdr_len;
471 	offset += hdr_padded_len;
472 	p += hdr_padded_len;
473 	tailroom = truesize - headroom  - hdr_padded_len - len;
474 
475 	shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
476 
477 	/* copy small packet so we can reuse these pages */
478 	if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) {
479 		skb = build_skb(buf, truesize);
480 		if (unlikely(!skb))
481 			return NULL;
482 
483 		skb_reserve(skb, p - buf);
484 		skb_put(skb, len);
485 
486 		page = (struct page *)page->private;
487 		if (page)
488 			give_pages(rq, page);
489 		goto ok;
490 	}
491 
492 	/* copy small packet so we can reuse these pages for small data */
493 	skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
494 	if (unlikely(!skb))
495 		return NULL;
496 
497 	/* Copy all frame if it fits skb->head, otherwise
498 	 * we let virtio_net_hdr_to_skb() and GRO pull headers as needed.
499 	 */
500 	if (len <= skb_tailroom(skb))
501 		copy = len;
502 	else
503 		copy = ETH_HLEN;
504 	skb_put_data(skb, p, copy);
505 
506 	len -= copy;
507 	offset += copy;
508 
509 	if (vi->mergeable_rx_bufs) {
510 		if (len)
511 			skb_add_rx_frag(skb, 0, page, offset, len, truesize);
512 		else
513 			page_to_free = page;
514 		goto ok;
515 	}
516 
517 	/*
518 	 * Verify that we can indeed put this data into a skb.
519 	 * This is here to handle cases when the device erroneously
520 	 * tries to receive more than is possible. This is usually
521 	 * the case of a broken device.
522 	 */
523 	if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
524 		net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
525 		dev_kfree_skb(skb);
526 		return NULL;
527 	}
528 	BUG_ON(offset >= PAGE_SIZE);
529 	while (len) {
530 		unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
531 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
532 				frag_size, truesize);
533 		len -= frag_size;
534 		page = (struct page *)page->private;
535 		offset = 0;
536 	}
537 
538 	if (page)
539 		give_pages(rq, page);
540 
541 ok:
542 	hdr = skb_vnet_hdr(skb);
543 	memcpy(hdr, hdr_p, hdr_len);
544 	if (page_to_free)
545 		put_page(page_to_free);
546 
547 	return skb;
548 }
549 
550 static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
551 {
552 	unsigned int len;
553 	unsigned int packets = 0;
554 	unsigned int bytes = 0;
555 	void *ptr;
556 
557 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
558 		if (likely(!is_xdp_frame(ptr))) {
559 			struct sk_buff *skb = ptr;
560 
561 			pr_debug("Sent skb %p\n", skb);
562 
563 			bytes += skb->len;
564 			napi_consume_skb(skb, in_napi);
565 		} else {
566 			struct xdp_frame *frame = ptr_to_xdp(ptr);
567 
568 			bytes += xdp_get_frame_len(frame);
569 			xdp_return_frame(frame);
570 		}
571 		packets++;
572 	}
573 
574 	/* Avoid overhead when no packets have been processed
575 	 * happens when called speculatively from start_xmit.
576 	 */
577 	if (!packets)
578 		return;
579 
580 	u64_stats_update_begin(&sq->stats.syncp);
581 	sq->stats.bytes += bytes;
582 	sq->stats.packets += packets;
583 	u64_stats_update_end(&sq->stats.syncp);
584 }
585 
586 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
587 {
588 	if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
589 		return false;
590 	else if (q < vi->curr_queue_pairs)
591 		return true;
592 	else
593 		return false;
594 }
595 
596 static void check_sq_full_and_disable(struct virtnet_info *vi,
597 				      struct net_device *dev,
598 				      struct send_queue *sq)
599 {
600 	bool use_napi = sq->napi.weight;
601 	int qnum;
602 
603 	qnum = sq - vi->sq;
604 
605 	/* If running out of space, stop queue to avoid getting packets that we
606 	 * are then unable to transmit.
607 	 * An alternative would be to force queuing layer to requeue the skb by
608 	 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
609 	 * returned in a normal path of operation: it means that driver is not
610 	 * maintaining the TX queue stop/start state properly, and causes
611 	 * the stack to do a non-trivial amount of useless work.
612 	 * Since most packets only take 1 or 2 ring slots, stopping the queue
613 	 * early means 16 slots are typically wasted.
614 	 */
615 	if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
616 		netif_stop_subqueue(dev, qnum);
617 		if (use_napi) {
618 			if (unlikely(!virtqueue_enable_cb_delayed(sq->vq)))
619 				virtqueue_napi_schedule(&sq->napi, sq->vq);
620 		} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
621 			/* More just got used, free them then recheck. */
622 			free_old_xmit_skbs(sq, false);
623 			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
624 				netif_start_subqueue(dev, qnum);
625 				virtqueue_disable_cb(sq->vq);
626 			}
627 		}
628 	}
629 }
630 
631 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
632 				   struct send_queue *sq,
633 				   struct xdp_frame *xdpf)
634 {
635 	struct virtio_net_hdr_mrg_rxbuf *hdr;
636 	struct skb_shared_info *shinfo;
637 	u8 nr_frags = 0;
638 	int err, i;
639 
640 	if (unlikely(xdpf->headroom < vi->hdr_len))
641 		return -EOVERFLOW;
642 
643 	if (unlikely(xdp_frame_has_frags(xdpf))) {
644 		shinfo = xdp_get_shared_info_from_frame(xdpf);
645 		nr_frags = shinfo->nr_frags;
646 	}
647 
648 	/* In wrapping function virtnet_xdp_xmit(), we need to free
649 	 * up the pending old buffers, where we need to calculate the
650 	 * position of skb_shared_info in xdp_get_frame_len() and
651 	 * xdp_return_frame(), which will involve to xdpf->data and
652 	 * xdpf->headroom. Therefore, we need to update the value of
653 	 * headroom synchronously here.
654 	 */
655 	xdpf->headroom -= vi->hdr_len;
656 	xdpf->data -= vi->hdr_len;
657 	/* Zero header and leave csum up to XDP layers */
658 	hdr = xdpf->data;
659 	memset(hdr, 0, vi->hdr_len);
660 	xdpf->len   += vi->hdr_len;
661 
662 	sg_init_table(sq->sg, nr_frags + 1);
663 	sg_set_buf(sq->sg, xdpf->data, xdpf->len);
664 	for (i = 0; i < nr_frags; i++) {
665 		skb_frag_t *frag = &shinfo->frags[i];
666 
667 		sg_set_page(&sq->sg[i + 1], skb_frag_page(frag),
668 			    skb_frag_size(frag), skb_frag_off(frag));
669 	}
670 
671 	err = virtqueue_add_outbuf(sq->vq, sq->sg, nr_frags + 1,
672 				   xdp_to_ptr(xdpf), GFP_ATOMIC);
673 	if (unlikely(err))
674 		return -ENOSPC; /* Caller handle free/refcnt */
675 
676 	return 0;
677 }
678 
679 /* when vi->curr_queue_pairs > nr_cpu_ids, the txq/sq is only used for xdp tx on
680  * the current cpu, so it does not need to be locked.
681  *
682  * Here we use marco instead of inline functions because we have to deal with
683  * three issues at the same time: 1. the choice of sq. 2. judge and execute the
684  * lock/unlock of txq 3. make sparse happy. It is difficult for two inline
685  * functions to perfectly solve these three problems at the same time.
686  */
687 #define virtnet_xdp_get_sq(vi) ({                                       \
688 	int cpu = smp_processor_id();                                   \
689 	struct netdev_queue *txq;                                       \
690 	typeof(vi) v = (vi);                                            \
691 	unsigned int qp;                                                \
692 									\
693 	if (v->curr_queue_pairs > nr_cpu_ids) {                         \
694 		qp = v->curr_queue_pairs - v->xdp_queue_pairs;          \
695 		qp += cpu;                                              \
696 		txq = netdev_get_tx_queue(v->dev, qp);                  \
697 		__netif_tx_acquire(txq);                                \
698 	} else {                                                        \
699 		qp = cpu % v->curr_queue_pairs;                         \
700 		txq = netdev_get_tx_queue(v->dev, qp);                  \
701 		__netif_tx_lock(txq, cpu);                              \
702 	}                                                               \
703 	v->sq + qp;                                                     \
704 })
705 
706 #define virtnet_xdp_put_sq(vi, q) {                                     \
707 	struct netdev_queue *txq;                                       \
708 	typeof(vi) v = (vi);                                            \
709 									\
710 	txq = netdev_get_tx_queue(v->dev, (q) - v->sq);                 \
711 	if (v->curr_queue_pairs > nr_cpu_ids)                           \
712 		__netif_tx_release(txq);                                \
713 	else                                                            \
714 		__netif_tx_unlock(txq);                                 \
715 }
716 
717 static int virtnet_xdp_xmit(struct net_device *dev,
718 			    int n, struct xdp_frame **frames, u32 flags)
719 {
720 	struct virtnet_info *vi = netdev_priv(dev);
721 	struct receive_queue *rq = vi->rq;
722 	struct bpf_prog *xdp_prog;
723 	struct send_queue *sq;
724 	unsigned int len;
725 	int packets = 0;
726 	int bytes = 0;
727 	int nxmit = 0;
728 	int kicks = 0;
729 	void *ptr;
730 	int ret;
731 	int i;
732 
733 	/* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
734 	 * indicate XDP resources have been successfully allocated.
735 	 */
736 	xdp_prog = rcu_access_pointer(rq->xdp_prog);
737 	if (!xdp_prog)
738 		return -ENXIO;
739 
740 	sq = virtnet_xdp_get_sq(vi);
741 
742 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
743 		ret = -EINVAL;
744 		goto out;
745 	}
746 
747 	/* Free up any pending old buffers before queueing new ones. */
748 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
749 		if (likely(is_xdp_frame(ptr))) {
750 			struct xdp_frame *frame = ptr_to_xdp(ptr);
751 
752 			bytes += xdp_get_frame_len(frame);
753 			xdp_return_frame(frame);
754 		} else {
755 			struct sk_buff *skb = ptr;
756 
757 			bytes += skb->len;
758 			napi_consume_skb(skb, false);
759 		}
760 		packets++;
761 	}
762 
763 	for (i = 0; i < n; i++) {
764 		struct xdp_frame *xdpf = frames[i];
765 
766 		if (__virtnet_xdp_xmit_one(vi, sq, xdpf))
767 			break;
768 		nxmit++;
769 	}
770 	ret = nxmit;
771 
772 	if (!is_xdp_raw_buffer_queue(vi, sq - vi->sq))
773 		check_sq_full_and_disable(vi, dev, sq);
774 
775 	if (flags & XDP_XMIT_FLUSH) {
776 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
777 			kicks = 1;
778 	}
779 out:
780 	u64_stats_update_begin(&sq->stats.syncp);
781 	sq->stats.bytes += bytes;
782 	sq->stats.packets += packets;
783 	sq->stats.xdp_tx += n;
784 	sq->stats.xdp_tx_drops += n - nxmit;
785 	sq->stats.kicks += kicks;
786 	u64_stats_update_end(&sq->stats.syncp);
787 
788 	virtnet_xdp_put_sq(vi, sq);
789 	return ret;
790 }
791 
792 static void put_xdp_frags(struct xdp_buff *xdp)
793 {
794 	struct skb_shared_info *shinfo;
795 	struct page *xdp_page;
796 	int i;
797 
798 	if (xdp_buff_has_frags(xdp)) {
799 		shinfo = xdp_get_shared_info_from_buff(xdp);
800 		for (i = 0; i < shinfo->nr_frags; i++) {
801 			xdp_page = skb_frag_page(&shinfo->frags[i]);
802 			put_page(xdp_page);
803 		}
804 	}
805 }
806 
807 static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
808 			       struct net_device *dev,
809 			       unsigned int *xdp_xmit,
810 			       struct virtnet_rq_stats *stats)
811 {
812 	struct xdp_frame *xdpf;
813 	int err;
814 	u32 act;
815 
816 	act = bpf_prog_run_xdp(xdp_prog, xdp);
817 	stats->xdp_packets++;
818 
819 	switch (act) {
820 	case XDP_PASS:
821 		return act;
822 
823 	case XDP_TX:
824 		stats->xdp_tx++;
825 		xdpf = xdp_convert_buff_to_frame(xdp);
826 		if (unlikely(!xdpf)) {
827 			netdev_dbg(dev, "convert buff to frame failed for xdp\n");
828 			return XDP_DROP;
829 		}
830 
831 		err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
832 		if (unlikely(!err)) {
833 			xdp_return_frame_rx_napi(xdpf);
834 		} else if (unlikely(err < 0)) {
835 			trace_xdp_exception(dev, xdp_prog, act);
836 			return XDP_DROP;
837 		}
838 		*xdp_xmit |= VIRTIO_XDP_TX;
839 		return act;
840 
841 	case XDP_REDIRECT:
842 		stats->xdp_redirects++;
843 		err = xdp_do_redirect(dev, xdp, xdp_prog);
844 		if (err)
845 			return XDP_DROP;
846 
847 		*xdp_xmit |= VIRTIO_XDP_REDIR;
848 		return act;
849 
850 	default:
851 		bpf_warn_invalid_xdp_action(dev, xdp_prog, act);
852 		fallthrough;
853 	case XDP_ABORTED:
854 		trace_xdp_exception(dev, xdp_prog, act);
855 		fallthrough;
856 	case XDP_DROP:
857 		return XDP_DROP;
858 	}
859 }
860 
861 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
862 {
863 	return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0;
864 }
865 
866 /* We copy the packet for XDP in the following cases:
867  *
868  * 1) Packet is scattered across multiple rx buffers.
869  * 2) Headroom space is insufficient.
870  *
871  * This is inefficient but it's a temporary condition that
872  * we hit right after XDP is enabled and until queue is refilled
873  * with large buffers with sufficient headroom - so it should affect
874  * at most queue size packets.
875  * Afterwards, the conditions to enable
876  * XDP should preclude the underlying device from sending packets
877  * across multiple buffers (num_buf > 1), and we make sure buffers
878  * have enough headroom.
879  */
880 static struct page *xdp_linearize_page(struct receive_queue *rq,
881 				       int *num_buf,
882 				       struct page *p,
883 				       int offset,
884 				       int page_off,
885 				       unsigned int *len)
886 {
887 	int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
888 	struct page *page;
889 
890 	if (page_off + *len + tailroom > PAGE_SIZE)
891 		return NULL;
892 
893 	page = alloc_page(GFP_ATOMIC);
894 	if (!page)
895 		return NULL;
896 
897 	memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
898 	page_off += *len;
899 
900 	while (--*num_buf) {
901 		unsigned int buflen;
902 		void *buf;
903 		int off;
904 
905 		buf = virtqueue_get_buf(rq->vq, &buflen);
906 		if (unlikely(!buf))
907 			goto err_buf;
908 
909 		p = virt_to_head_page(buf);
910 		off = buf - page_address(p);
911 
912 		/* guard against a misconfigured or uncooperative backend that
913 		 * is sending packet larger than the MTU.
914 		 */
915 		if ((page_off + buflen + tailroom) > PAGE_SIZE) {
916 			put_page(p);
917 			goto err_buf;
918 		}
919 
920 		memcpy(page_address(page) + page_off,
921 		       page_address(p) + off, buflen);
922 		page_off += buflen;
923 		put_page(p);
924 	}
925 
926 	/* Headroom does not contribute to packet length */
927 	*len = page_off - VIRTIO_XDP_HEADROOM;
928 	return page;
929 err_buf:
930 	__free_pages(page, 0);
931 	return NULL;
932 }
933 
934 static struct sk_buff *receive_small(struct net_device *dev,
935 				     struct virtnet_info *vi,
936 				     struct receive_queue *rq,
937 				     void *buf, void *ctx,
938 				     unsigned int len,
939 				     unsigned int *xdp_xmit,
940 				     struct virtnet_rq_stats *stats)
941 {
942 	struct sk_buff *skb;
943 	struct bpf_prog *xdp_prog;
944 	unsigned int xdp_headroom = (unsigned long)ctx;
945 	unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
946 	unsigned int headroom = vi->hdr_len + header_offset;
947 	unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
948 			      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
949 	struct page *page = virt_to_head_page(buf);
950 	unsigned int delta = 0;
951 	struct page *xdp_page;
952 	unsigned int metasize = 0;
953 
954 	len -= vi->hdr_len;
955 	stats->bytes += len;
956 
957 	if (unlikely(len > GOOD_PACKET_LEN)) {
958 		pr_debug("%s: rx error: len %u exceeds max size %d\n",
959 			 dev->name, len, GOOD_PACKET_LEN);
960 		dev->stats.rx_length_errors++;
961 		goto err;
962 	}
963 
964 	if (likely(!vi->xdp_enabled)) {
965 		xdp_prog = NULL;
966 		goto skip_xdp;
967 	}
968 
969 	rcu_read_lock();
970 	xdp_prog = rcu_dereference(rq->xdp_prog);
971 	if (xdp_prog) {
972 		struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
973 		struct xdp_buff xdp;
974 		void *orig_data;
975 		u32 act;
976 
977 		if (unlikely(hdr->hdr.gso_type))
978 			goto err_xdp;
979 
980 		if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
981 			int offset = buf - page_address(page) + header_offset;
982 			unsigned int tlen = len + vi->hdr_len;
983 			int num_buf = 1;
984 
985 			xdp_headroom = virtnet_get_headroom(vi);
986 			header_offset = VIRTNET_RX_PAD + xdp_headroom;
987 			headroom = vi->hdr_len + header_offset;
988 			buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
989 				 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
990 			xdp_page = xdp_linearize_page(rq, &num_buf, page,
991 						      offset, header_offset,
992 						      &tlen);
993 			if (!xdp_page)
994 				goto err_xdp;
995 
996 			buf = page_address(xdp_page);
997 			put_page(page);
998 			page = xdp_page;
999 		}
1000 
1001 		xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
1002 		xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
1003 				 xdp_headroom, len, true);
1004 		orig_data = xdp.data;
1005 
1006 		act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats);
1007 
1008 		switch (act) {
1009 		case XDP_PASS:
1010 			/* Recalculate length in case bpf program changed it */
1011 			delta = orig_data - xdp.data;
1012 			len = xdp.data_end - xdp.data;
1013 			metasize = xdp.data - xdp.data_meta;
1014 			break;
1015 		case XDP_TX:
1016 		case XDP_REDIRECT:
1017 			rcu_read_unlock();
1018 			goto xdp_xmit;
1019 		default:
1020 			goto err_xdp;
1021 		}
1022 	}
1023 	rcu_read_unlock();
1024 
1025 skip_xdp:
1026 	skb = build_skb(buf, buflen);
1027 	if (!skb)
1028 		goto err;
1029 	skb_reserve(skb, headroom - delta);
1030 	skb_put(skb, len);
1031 	if (!xdp_prog) {
1032 		buf += header_offset;
1033 		memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
1034 	} /* keep zeroed vnet hdr since XDP is loaded */
1035 
1036 	if (metasize)
1037 		skb_metadata_set(skb, metasize);
1038 
1039 	return skb;
1040 
1041 err_xdp:
1042 	rcu_read_unlock();
1043 	stats->xdp_drops++;
1044 err:
1045 	stats->drops++;
1046 	put_page(page);
1047 xdp_xmit:
1048 	return NULL;
1049 }
1050 
1051 static struct sk_buff *receive_big(struct net_device *dev,
1052 				   struct virtnet_info *vi,
1053 				   struct receive_queue *rq,
1054 				   void *buf,
1055 				   unsigned int len,
1056 				   struct virtnet_rq_stats *stats)
1057 {
1058 	struct page *page = buf;
1059 	struct sk_buff *skb =
1060 		page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, 0);
1061 
1062 	stats->bytes += len - vi->hdr_len;
1063 	if (unlikely(!skb))
1064 		goto err;
1065 
1066 	return skb;
1067 
1068 err:
1069 	stats->drops++;
1070 	give_pages(rq, page);
1071 	return NULL;
1072 }
1073 
1074 /* Why not use xdp_build_skb_from_frame() ?
1075  * XDP core assumes that xdp frags are PAGE_SIZE in length, while in
1076  * virtio-net there are 2 points that do not match its requirements:
1077  *  1. The size of the prefilled buffer is not fixed before xdp is set.
1078  *  2. xdp_build_skb_from_frame() does more checks that we don't need,
1079  *     like eth_type_trans() (which virtio-net does in receive_buf()).
1080  */
1081 static struct sk_buff *build_skb_from_xdp_buff(struct net_device *dev,
1082 					       struct virtnet_info *vi,
1083 					       struct xdp_buff *xdp,
1084 					       unsigned int xdp_frags_truesz)
1085 {
1086 	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
1087 	unsigned int headroom, data_len;
1088 	struct sk_buff *skb;
1089 	int metasize;
1090 	u8 nr_frags;
1091 
1092 	if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) {
1093 		pr_debug("Error building skb as missing reserved tailroom for xdp");
1094 		return NULL;
1095 	}
1096 
1097 	if (unlikely(xdp_buff_has_frags(xdp)))
1098 		nr_frags = sinfo->nr_frags;
1099 
1100 	skb = build_skb(xdp->data_hard_start, xdp->frame_sz);
1101 	if (unlikely(!skb))
1102 		return NULL;
1103 
1104 	headroom = xdp->data - xdp->data_hard_start;
1105 	data_len = xdp->data_end - xdp->data;
1106 	skb_reserve(skb, headroom);
1107 	__skb_put(skb, data_len);
1108 
1109 	metasize = xdp->data - xdp->data_meta;
1110 	metasize = metasize > 0 ? metasize : 0;
1111 	if (metasize)
1112 		skb_metadata_set(skb, metasize);
1113 
1114 	if (unlikely(xdp_buff_has_frags(xdp)))
1115 		xdp_update_skb_shared_info(skb, nr_frags,
1116 					   sinfo->xdp_frags_size,
1117 					   xdp_frags_truesz,
1118 					   xdp_buff_is_frag_pfmemalloc(xdp));
1119 
1120 	return skb;
1121 }
1122 
1123 /* TODO: build xdp in big mode */
1124 static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
1125 				      struct virtnet_info *vi,
1126 				      struct receive_queue *rq,
1127 				      struct xdp_buff *xdp,
1128 				      void *buf,
1129 				      unsigned int len,
1130 				      unsigned int frame_sz,
1131 				      int *num_buf,
1132 				      unsigned int *xdp_frags_truesize,
1133 				      struct virtnet_rq_stats *stats)
1134 {
1135 	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
1136 	unsigned int headroom, tailroom, room;
1137 	unsigned int truesize, cur_frag_size;
1138 	struct skb_shared_info *shinfo;
1139 	unsigned int xdp_frags_truesz = 0;
1140 	struct page *page;
1141 	skb_frag_t *frag;
1142 	int offset;
1143 	void *ctx;
1144 
1145 	xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
1146 	xdp_prepare_buff(xdp, buf - VIRTIO_XDP_HEADROOM,
1147 			 VIRTIO_XDP_HEADROOM + vi->hdr_len, len - vi->hdr_len, true);
1148 
1149 	if (!*num_buf)
1150 		return 0;
1151 
1152 	if (*num_buf > 1) {
1153 		/* If we want to build multi-buffer xdp, we need
1154 		 * to specify that the flags of xdp_buff have the
1155 		 * XDP_FLAGS_HAS_FRAG bit.
1156 		 */
1157 		if (!xdp_buff_has_frags(xdp))
1158 			xdp_buff_set_frags_flag(xdp);
1159 
1160 		shinfo = xdp_get_shared_info_from_buff(xdp);
1161 		shinfo->nr_frags = 0;
1162 		shinfo->xdp_frags_size = 0;
1163 	}
1164 
1165 	if (*num_buf > MAX_SKB_FRAGS + 1)
1166 		return -EINVAL;
1167 
1168 	while (--*num_buf > 0) {
1169 		buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1170 		if (unlikely(!buf)) {
1171 			pr_debug("%s: rx error: %d buffers out of %d missing\n",
1172 				 dev->name, *num_buf,
1173 				 virtio16_to_cpu(vi->vdev, hdr->num_buffers));
1174 			dev->stats.rx_length_errors++;
1175 			return -EINVAL;
1176 		}
1177 
1178 		stats->bytes += len;
1179 		page = virt_to_head_page(buf);
1180 		offset = buf - page_address(page);
1181 
1182 		truesize = mergeable_ctx_to_truesize(ctx);
1183 		headroom = mergeable_ctx_to_headroom(ctx);
1184 		tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1185 		room = SKB_DATA_ALIGN(headroom + tailroom);
1186 
1187 		cur_frag_size = truesize;
1188 		xdp_frags_truesz += cur_frag_size;
1189 		if (unlikely(len > truesize - room || cur_frag_size > PAGE_SIZE)) {
1190 			put_page(page);
1191 			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1192 				 dev->name, len, (unsigned long)(truesize - room));
1193 			dev->stats.rx_length_errors++;
1194 			return -EINVAL;
1195 		}
1196 
1197 		frag = &shinfo->frags[shinfo->nr_frags++];
1198 		__skb_frag_set_page(frag, page);
1199 		skb_frag_off_set(frag, offset);
1200 		skb_frag_size_set(frag, len);
1201 		if (page_is_pfmemalloc(page))
1202 			xdp_buff_set_frag_pfmemalloc(xdp);
1203 
1204 		shinfo->xdp_frags_size += len;
1205 	}
1206 
1207 	*xdp_frags_truesize = xdp_frags_truesz;
1208 	return 0;
1209 }
1210 
1211 static void *mergeable_xdp_get_buf(struct virtnet_info *vi,
1212 				   struct receive_queue *rq,
1213 				   struct bpf_prog *xdp_prog,
1214 				   void *ctx,
1215 				   unsigned int *frame_sz,
1216 				   int *num_buf,
1217 				   struct page **page,
1218 				   int offset,
1219 				   unsigned int *len,
1220 				   struct virtio_net_hdr_mrg_rxbuf *hdr)
1221 {
1222 	unsigned int truesize = mergeable_ctx_to_truesize(ctx);
1223 	unsigned int headroom = mergeable_ctx_to_headroom(ctx);
1224 	struct page *xdp_page;
1225 	unsigned int xdp_room;
1226 
1227 	/* Transient failure which in theory could occur if
1228 	 * in-flight packets from before XDP was enabled reach
1229 	 * the receive path after XDP is loaded.
1230 	 */
1231 	if (unlikely(hdr->hdr.gso_type))
1232 		return NULL;
1233 
1234 	/* Now XDP core assumes frag size is PAGE_SIZE, but buffers
1235 	 * with headroom may add hole in truesize, which
1236 	 * make their length exceed PAGE_SIZE. So we disabled the
1237 	 * hole mechanism for xdp. See add_recvbuf_mergeable().
1238 	 */
1239 	*frame_sz = truesize;
1240 
1241 	if (likely(headroom >= virtnet_get_headroom(vi) &&
1242 		   (*num_buf == 1 || xdp_prog->aux->xdp_has_frags))) {
1243 		return page_address(*page) + offset;
1244 	}
1245 
1246 	/* This happens when headroom is not enough because
1247 	 * of the buffer was prefilled before XDP is set.
1248 	 * This should only happen for the first several packets.
1249 	 * In fact, vq reset can be used here to help us clean up
1250 	 * the prefilled buffers, but many existing devices do not
1251 	 * support it, and we don't want to bother users who are
1252 	 * using xdp normally.
1253 	 */
1254 	if (!xdp_prog->aux->xdp_has_frags) {
1255 		/* linearize data for XDP */
1256 		xdp_page = xdp_linearize_page(rq, num_buf,
1257 					      *page, offset,
1258 					      VIRTIO_XDP_HEADROOM,
1259 					      len);
1260 		if (!xdp_page)
1261 			return NULL;
1262 	} else {
1263 		xdp_room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM +
1264 					  sizeof(struct skb_shared_info));
1265 		if (*len + xdp_room > PAGE_SIZE)
1266 			return NULL;
1267 
1268 		xdp_page = alloc_page(GFP_ATOMIC);
1269 		if (!xdp_page)
1270 			return NULL;
1271 
1272 		memcpy(page_address(xdp_page) + VIRTIO_XDP_HEADROOM,
1273 		       page_address(*page) + offset, *len);
1274 	}
1275 
1276 	*frame_sz = PAGE_SIZE;
1277 
1278 	put_page(*page);
1279 
1280 	*page = xdp_page;
1281 
1282 	return page_address(*page) + VIRTIO_XDP_HEADROOM;
1283 }
1284 
1285 static struct sk_buff *receive_mergeable(struct net_device *dev,
1286 					 struct virtnet_info *vi,
1287 					 struct receive_queue *rq,
1288 					 void *buf,
1289 					 void *ctx,
1290 					 unsigned int len,
1291 					 unsigned int *xdp_xmit,
1292 					 struct virtnet_rq_stats *stats)
1293 {
1294 	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
1295 	int num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
1296 	struct page *page = virt_to_head_page(buf);
1297 	int offset = buf - page_address(page);
1298 	struct sk_buff *head_skb, *curr_skb;
1299 	struct bpf_prog *xdp_prog;
1300 	unsigned int truesize = mergeable_ctx_to_truesize(ctx);
1301 	unsigned int headroom = mergeable_ctx_to_headroom(ctx);
1302 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1303 	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1304 	unsigned int frame_sz;
1305 	int err;
1306 
1307 	head_skb = NULL;
1308 	stats->bytes += len - vi->hdr_len;
1309 
1310 	if (unlikely(len > truesize - room)) {
1311 		pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1312 			 dev->name, len, (unsigned long)(truesize - room));
1313 		dev->stats.rx_length_errors++;
1314 		goto err_skb;
1315 	}
1316 
1317 	if (likely(!vi->xdp_enabled)) {
1318 		xdp_prog = NULL;
1319 		goto skip_xdp;
1320 	}
1321 
1322 	rcu_read_lock();
1323 	xdp_prog = rcu_dereference(rq->xdp_prog);
1324 	if (xdp_prog) {
1325 		unsigned int xdp_frags_truesz = 0;
1326 		struct xdp_buff xdp;
1327 		void *data;
1328 		u32 act;
1329 
1330 		data = mergeable_xdp_get_buf(vi, rq, xdp_prog, ctx, &frame_sz,
1331 					     &num_buf, &page, offset, &len, hdr);
1332 		if (unlikely(!data))
1333 			goto err_xdp;
1334 
1335 		err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz,
1336 						 &num_buf, &xdp_frags_truesz, stats);
1337 		if (unlikely(err))
1338 			goto err_xdp_frags;
1339 
1340 		act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats);
1341 
1342 		switch (act) {
1343 		case XDP_PASS:
1344 			head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
1345 			if (unlikely(!head_skb))
1346 				goto err_xdp_frags;
1347 
1348 			rcu_read_unlock();
1349 			return head_skb;
1350 		case XDP_TX:
1351 		case XDP_REDIRECT:
1352 			rcu_read_unlock();
1353 			goto xdp_xmit;
1354 		default:
1355 			break;
1356 		}
1357 err_xdp_frags:
1358 		put_xdp_frags(&xdp);
1359 		goto err_xdp;
1360 	}
1361 	rcu_read_unlock();
1362 
1363 skip_xdp:
1364 	head_skb = page_to_skb(vi, rq, page, offset, len, truesize, headroom);
1365 	curr_skb = head_skb;
1366 
1367 	if (unlikely(!curr_skb))
1368 		goto err_skb;
1369 	while (--num_buf) {
1370 		int num_skb_frags;
1371 
1372 		buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1373 		if (unlikely(!buf)) {
1374 			pr_debug("%s: rx error: %d buffers out of %d missing\n",
1375 				 dev->name, num_buf,
1376 				 virtio16_to_cpu(vi->vdev,
1377 						 hdr->num_buffers));
1378 			dev->stats.rx_length_errors++;
1379 			goto err_buf;
1380 		}
1381 
1382 		stats->bytes += len;
1383 		page = virt_to_head_page(buf);
1384 
1385 		truesize = mergeable_ctx_to_truesize(ctx);
1386 		headroom = mergeable_ctx_to_headroom(ctx);
1387 		tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1388 		room = SKB_DATA_ALIGN(headroom + tailroom);
1389 		if (unlikely(len > truesize - room)) {
1390 			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1391 				 dev->name, len, (unsigned long)(truesize - room));
1392 			dev->stats.rx_length_errors++;
1393 			goto err_skb;
1394 		}
1395 
1396 		num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
1397 		if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
1398 			struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
1399 
1400 			if (unlikely(!nskb))
1401 				goto err_skb;
1402 			if (curr_skb == head_skb)
1403 				skb_shinfo(curr_skb)->frag_list = nskb;
1404 			else
1405 				curr_skb->next = nskb;
1406 			curr_skb = nskb;
1407 			head_skb->truesize += nskb->truesize;
1408 			num_skb_frags = 0;
1409 		}
1410 		if (curr_skb != head_skb) {
1411 			head_skb->data_len += len;
1412 			head_skb->len += len;
1413 			head_skb->truesize += truesize;
1414 		}
1415 		offset = buf - page_address(page);
1416 		if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
1417 			put_page(page);
1418 			skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
1419 					     len, truesize);
1420 		} else {
1421 			skb_add_rx_frag(curr_skb, num_skb_frags, page,
1422 					offset, len, truesize);
1423 		}
1424 	}
1425 
1426 	ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
1427 	return head_skb;
1428 
1429 err_xdp:
1430 	rcu_read_unlock();
1431 	stats->xdp_drops++;
1432 err_skb:
1433 	put_page(page);
1434 	while (num_buf-- > 1) {
1435 		buf = virtqueue_get_buf(rq->vq, &len);
1436 		if (unlikely(!buf)) {
1437 			pr_debug("%s: rx error: %d buffers missing\n",
1438 				 dev->name, num_buf);
1439 			dev->stats.rx_length_errors++;
1440 			break;
1441 		}
1442 		stats->bytes += len;
1443 		page = virt_to_head_page(buf);
1444 		put_page(page);
1445 	}
1446 err_buf:
1447 	stats->drops++;
1448 	dev_kfree_skb(head_skb);
1449 xdp_xmit:
1450 	return NULL;
1451 }
1452 
1453 static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
1454 				struct sk_buff *skb)
1455 {
1456 	enum pkt_hash_types rss_hash_type;
1457 
1458 	if (!hdr_hash || !skb)
1459 		return;
1460 
1461 	switch (__le16_to_cpu(hdr_hash->hash_report)) {
1462 	case VIRTIO_NET_HASH_REPORT_TCPv4:
1463 	case VIRTIO_NET_HASH_REPORT_UDPv4:
1464 	case VIRTIO_NET_HASH_REPORT_TCPv6:
1465 	case VIRTIO_NET_HASH_REPORT_UDPv6:
1466 	case VIRTIO_NET_HASH_REPORT_TCPv6_EX:
1467 	case VIRTIO_NET_HASH_REPORT_UDPv6_EX:
1468 		rss_hash_type = PKT_HASH_TYPE_L4;
1469 		break;
1470 	case VIRTIO_NET_HASH_REPORT_IPv4:
1471 	case VIRTIO_NET_HASH_REPORT_IPv6:
1472 	case VIRTIO_NET_HASH_REPORT_IPv6_EX:
1473 		rss_hash_type = PKT_HASH_TYPE_L3;
1474 		break;
1475 	case VIRTIO_NET_HASH_REPORT_NONE:
1476 	default:
1477 		rss_hash_type = PKT_HASH_TYPE_NONE;
1478 	}
1479 	skb_set_hash(skb, __le32_to_cpu(hdr_hash->hash_value), rss_hash_type);
1480 }
1481 
1482 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1483 			void *buf, unsigned int len, void **ctx,
1484 			unsigned int *xdp_xmit,
1485 			struct virtnet_rq_stats *stats)
1486 {
1487 	struct net_device *dev = vi->dev;
1488 	struct sk_buff *skb;
1489 	struct virtio_net_hdr_mrg_rxbuf *hdr;
1490 
1491 	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1492 		pr_debug("%s: short packet %i\n", dev->name, len);
1493 		dev->stats.rx_length_errors++;
1494 		virtnet_rq_free_unused_buf(rq->vq, buf);
1495 		return;
1496 	}
1497 
1498 	if (vi->mergeable_rx_bufs)
1499 		skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1500 					stats);
1501 	else if (vi->big_packets)
1502 		skb = receive_big(dev, vi, rq, buf, len, stats);
1503 	else
1504 		skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1505 
1506 	if (unlikely(!skb))
1507 		return;
1508 
1509 	hdr = skb_vnet_hdr(skb);
1510 	if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
1511 		virtio_skb_set_hash((const struct virtio_net_hdr_v1_hash *)hdr, skb);
1512 
1513 	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1514 		skb->ip_summed = CHECKSUM_UNNECESSARY;
1515 
1516 	if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1517 				  virtio_is_little_endian(vi->vdev))) {
1518 		net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1519 				     dev->name, hdr->hdr.gso_type,
1520 				     hdr->hdr.gso_size);
1521 		goto frame_err;
1522 	}
1523 
1524 	skb_record_rx_queue(skb, vq2rxq(rq->vq));
1525 	skb->protocol = eth_type_trans(skb, dev);
1526 	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1527 		 ntohs(skb->protocol), skb->len, skb->pkt_type);
1528 
1529 	napi_gro_receive(&rq->napi, skb);
1530 	return;
1531 
1532 frame_err:
1533 	dev->stats.rx_frame_errors++;
1534 	dev_kfree_skb(skb);
1535 }
1536 
1537 /* Unlike mergeable buffers, all buffers are allocated to the
1538  * same size, except for the headroom. For this reason we do
1539  * not need to use  mergeable_len_to_ctx here - it is enough
1540  * to store the headroom as the context ignoring the truesize.
1541  */
1542 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1543 			     gfp_t gfp)
1544 {
1545 	struct page_frag *alloc_frag = &rq->alloc_frag;
1546 	char *buf;
1547 	unsigned int xdp_headroom = virtnet_get_headroom(vi);
1548 	void *ctx = (void *)(unsigned long)xdp_headroom;
1549 	int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1550 	int err;
1551 
1552 	len = SKB_DATA_ALIGN(len) +
1553 	      SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1554 	if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1555 		return -ENOMEM;
1556 
1557 	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1558 	get_page(alloc_frag->page);
1559 	alloc_frag->offset += len;
1560 	sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1561 		    vi->hdr_len + GOOD_PACKET_LEN);
1562 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1563 	if (err < 0)
1564 		put_page(virt_to_head_page(buf));
1565 	return err;
1566 }
1567 
1568 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1569 			   gfp_t gfp)
1570 {
1571 	struct page *first, *list = NULL;
1572 	char *p;
1573 	int i, err, offset;
1574 
1575 	sg_init_table(rq->sg, vi->big_packets_num_skbfrags + 2);
1576 
1577 	/* page in rq->sg[vi->big_packets_num_skbfrags + 1] is list tail */
1578 	for (i = vi->big_packets_num_skbfrags + 1; i > 1; --i) {
1579 		first = get_a_page(rq, gfp);
1580 		if (!first) {
1581 			if (list)
1582 				give_pages(rq, list);
1583 			return -ENOMEM;
1584 		}
1585 		sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1586 
1587 		/* chain new page in list head to match sg */
1588 		first->private = (unsigned long)list;
1589 		list = first;
1590 	}
1591 
1592 	first = get_a_page(rq, gfp);
1593 	if (!first) {
1594 		give_pages(rq, list);
1595 		return -ENOMEM;
1596 	}
1597 	p = page_address(first);
1598 
1599 	/* rq->sg[0], rq->sg[1] share the same page */
1600 	/* a separated rq->sg[0] for header - required in case !any_header_sg */
1601 	sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1602 
1603 	/* rq->sg[1] for data packet, from offset */
1604 	offset = sizeof(struct padded_vnet_hdr);
1605 	sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1606 
1607 	/* chain first in list head */
1608 	first->private = (unsigned long)list;
1609 	err = virtqueue_add_inbuf(rq->vq, rq->sg, vi->big_packets_num_skbfrags + 2,
1610 				  first, gfp);
1611 	if (err < 0)
1612 		give_pages(rq, first);
1613 
1614 	return err;
1615 }
1616 
1617 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1618 					  struct ewma_pkt_len *avg_pkt_len,
1619 					  unsigned int room)
1620 {
1621 	struct virtnet_info *vi = rq->vq->vdev->priv;
1622 	const size_t hdr_len = vi->hdr_len;
1623 	unsigned int len;
1624 
1625 	if (room)
1626 		return PAGE_SIZE - room;
1627 
1628 	len = hdr_len +	clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1629 				rq->min_buf_len, PAGE_SIZE - hdr_len);
1630 
1631 	return ALIGN(len, L1_CACHE_BYTES);
1632 }
1633 
1634 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1635 				 struct receive_queue *rq, gfp_t gfp)
1636 {
1637 	struct page_frag *alloc_frag = &rq->alloc_frag;
1638 	unsigned int headroom = virtnet_get_headroom(vi);
1639 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1640 	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1641 	char *buf;
1642 	void *ctx;
1643 	int err;
1644 	unsigned int len, hole;
1645 
1646 	/* Extra tailroom is needed to satisfy XDP's assumption. This
1647 	 * means rx frags coalescing won't work, but consider we've
1648 	 * disabled GSO for XDP, it won't be a big issue.
1649 	 */
1650 	len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1651 	if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1652 		return -ENOMEM;
1653 
1654 	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1655 	buf += headroom; /* advance address leaving hole at front of pkt */
1656 	get_page(alloc_frag->page);
1657 	alloc_frag->offset += len + room;
1658 	hole = alloc_frag->size - alloc_frag->offset;
1659 	if (hole < len + room) {
1660 		/* To avoid internal fragmentation, if there is very likely not
1661 		 * enough space for another buffer, add the remaining space to
1662 		 * the current buffer.
1663 		 * XDP core assumes that frame_size of xdp_buff and the length
1664 		 * of the frag are PAGE_SIZE, so we disable the hole mechanism.
1665 		 */
1666 		if (!headroom)
1667 			len += hole;
1668 		alloc_frag->offset += hole;
1669 	}
1670 
1671 	sg_init_one(rq->sg, buf, len);
1672 	ctx = mergeable_len_to_ctx(len + room, headroom);
1673 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1674 	if (err < 0)
1675 		put_page(virt_to_head_page(buf));
1676 
1677 	return err;
1678 }
1679 
1680 /*
1681  * Returns false if we couldn't fill entirely (OOM).
1682  *
1683  * Normally run in the receive path, but can also be run from ndo_open
1684  * before we're receiving packets, or from refill_work which is
1685  * careful to disable receiving (using napi_disable).
1686  */
1687 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1688 			  gfp_t gfp)
1689 {
1690 	int err;
1691 	bool oom;
1692 
1693 	do {
1694 		if (vi->mergeable_rx_bufs)
1695 			err = add_recvbuf_mergeable(vi, rq, gfp);
1696 		else if (vi->big_packets)
1697 			err = add_recvbuf_big(vi, rq, gfp);
1698 		else
1699 			err = add_recvbuf_small(vi, rq, gfp);
1700 
1701 		oom = err == -ENOMEM;
1702 		if (err)
1703 			break;
1704 	} while (rq->vq->num_free);
1705 	if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1706 		unsigned long flags;
1707 
1708 		flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
1709 		rq->stats.kicks++;
1710 		u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
1711 	}
1712 
1713 	return !oom;
1714 }
1715 
1716 static void skb_recv_done(struct virtqueue *rvq)
1717 {
1718 	struct virtnet_info *vi = rvq->vdev->priv;
1719 	struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1720 
1721 	virtqueue_napi_schedule(&rq->napi, rvq);
1722 }
1723 
1724 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1725 {
1726 	napi_enable(napi);
1727 
1728 	/* If all buffers were filled by other side before we napi_enabled, we
1729 	 * won't get another interrupt, so process any outstanding packets now.
1730 	 * Call local_bh_enable after to trigger softIRQ processing.
1731 	 */
1732 	local_bh_disable();
1733 	virtqueue_napi_schedule(napi, vq);
1734 	local_bh_enable();
1735 }
1736 
1737 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1738 				   struct virtqueue *vq,
1739 				   struct napi_struct *napi)
1740 {
1741 	if (!napi->weight)
1742 		return;
1743 
1744 	/* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1745 	 * enable the feature if this is likely affine with the transmit path.
1746 	 */
1747 	if (!vi->affinity_hint_set) {
1748 		napi->weight = 0;
1749 		return;
1750 	}
1751 
1752 	return virtnet_napi_enable(vq, napi);
1753 }
1754 
1755 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1756 {
1757 	if (napi->weight)
1758 		napi_disable(napi);
1759 }
1760 
1761 static void refill_work(struct work_struct *work)
1762 {
1763 	struct virtnet_info *vi =
1764 		container_of(work, struct virtnet_info, refill.work);
1765 	bool still_empty;
1766 	int i;
1767 
1768 	for (i = 0; i < vi->curr_queue_pairs; i++) {
1769 		struct receive_queue *rq = &vi->rq[i];
1770 
1771 		napi_disable(&rq->napi);
1772 		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1773 		virtnet_napi_enable(rq->vq, &rq->napi);
1774 
1775 		/* In theory, this can happen: if we don't get any buffers in
1776 		 * we will *never* try to fill again.
1777 		 */
1778 		if (still_empty)
1779 			schedule_delayed_work(&vi->refill, HZ/2);
1780 	}
1781 }
1782 
1783 static int virtnet_receive(struct receive_queue *rq, int budget,
1784 			   unsigned int *xdp_xmit)
1785 {
1786 	struct virtnet_info *vi = rq->vq->vdev->priv;
1787 	struct virtnet_rq_stats stats = {};
1788 	unsigned int len;
1789 	void *buf;
1790 	int i;
1791 
1792 	if (!vi->big_packets || vi->mergeable_rx_bufs) {
1793 		void *ctx;
1794 
1795 		while (stats.packets < budget &&
1796 		       (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1797 			receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1798 			stats.packets++;
1799 		}
1800 	} else {
1801 		while (stats.packets < budget &&
1802 		       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1803 			receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1804 			stats.packets++;
1805 		}
1806 	}
1807 
1808 	if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1809 		if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
1810 			spin_lock(&vi->refill_lock);
1811 			if (vi->refill_enabled)
1812 				schedule_delayed_work(&vi->refill, 0);
1813 			spin_unlock(&vi->refill_lock);
1814 		}
1815 	}
1816 
1817 	u64_stats_update_begin(&rq->stats.syncp);
1818 	for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1819 		size_t offset = virtnet_rq_stats_desc[i].offset;
1820 		u64 *item;
1821 
1822 		item = (u64 *)((u8 *)&rq->stats + offset);
1823 		*item += *(u64 *)((u8 *)&stats + offset);
1824 	}
1825 	u64_stats_update_end(&rq->stats.syncp);
1826 
1827 	return stats.packets;
1828 }
1829 
1830 static void virtnet_poll_cleantx(struct receive_queue *rq)
1831 {
1832 	struct virtnet_info *vi = rq->vq->vdev->priv;
1833 	unsigned int index = vq2rxq(rq->vq);
1834 	struct send_queue *sq = &vi->sq[index];
1835 	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1836 
1837 	if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1838 		return;
1839 
1840 	if (__netif_tx_trylock(txq)) {
1841 		if (sq->reset) {
1842 			__netif_tx_unlock(txq);
1843 			return;
1844 		}
1845 
1846 		do {
1847 			virtqueue_disable_cb(sq->vq);
1848 			free_old_xmit_skbs(sq, true);
1849 		} while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1850 
1851 		if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1852 			netif_tx_wake_queue(txq);
1853 
1854 		__netif_tx_unlock(txq);
1855 	}
1856 }
1857 
1858 static int virtnet_poll(struct napi_struct *napi, int budget)
1859 {
1860 	struct receive_queue *rq =
1861 		container_of(napi, struct receive_queue, napi);
1862 	struct virtnet_info *vi = rq->vq->vdev->priv;
1863 	struct send_queue *sq;
1864 	unsigned int received;
1865 	unsigned int xdp_xmit = 0;
1866 
1867 	virtnet_poll_cleantx(rq);
1868 
1869 	received = virtnet_receive(rq, budget, &xdp_xmit);
1870 
1871 	if (xdp_xmit & VIRTIO_XDP_REDIR)
1872 		xdp_do_flush();
1873 
1874 	/* Out of packets? */
1875 	if (received < budget)
1876 		virtqueue_napi_complete(napi, rq->vq, received);
1877 
1878 	if (xdp_xmit & VIRTIO_XDP_TX) {
1879 		sq = virtnet_xdp_get_sq(vi);
1880 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1881 			u64_stats_update_begin(&sq->stats.syncp);
1882 			sq->stats.kicks++;
1883 			u64_stats_update_end(&sq->stats.syncp);
1884 		}
1885 		virtnet_xdp_put_sq(vi, sq);
1886 	}
1887 
1888 	return received;
1889 }
1890 
1891 static int virtnet_open(struct net_device *dev)
1892 {
1893 	struct virtnet_info *vi = netdev_priv(dev);
1894 	int i, err;
1895 
1896 	enable_delayed_refill(vi);
1897 
1898 	for (i = 0; i < vi->max_queue_pairs; i++) {
1899 		if (i < vi->curr_queue_pairs)
1900 			/* Make sure we have some buffers: if oom use wq. */
1901 			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1902 				schedule_delayed_work(&vi->refill, 0);
1903 
1904 		err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
1905 		if (err < 0)
1906 			return err;
1907 
1908 		err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1909 						 MEM_TYPE_PAGE_SHARED, NULL);
1910 		if (err < 0) {
1911 			xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1912 			return err;
1913 		}
1914 
1915 		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1916 		virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1917 	}
1918 
1919 	return 0;
1920 }
1921 
1922 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1923 {
1924 	struct send_queue *sq = container_of(napi, struct send_queue, napi);
1925 	struct virtnet_info *vi = sq->vq->vdev->priv;
1926 	unsigned int index = vq2txq(sq->vq);
1927 	struct netdev_queue *txq;
1928 	int opaque;
1929 	bool done;
1930 
1931 	if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1932 		/* We don't need to enable cb for XDP */
1933 		napi_complete_done(napi, 0);
1934 		return 0;
1935 	}
1936 
1937 	txq = netdev_get_tx_queue(vi->dev, index);
1938 	__netif_tx_lock(txq, raw_smp_processor_id());
1939 	virtqueue_disable_cb(sq->vq);
1940 	free_old_xmit_skbs(sq, true);
1941 
1942 	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1943 		netif_tx_wake_queue(txq);
1944 
1945 	opaque = virtqueue_enable_cb_prepare(sq->vq);
1946 
1947 	done = napi_complete_done(napi, 0);
1948 
1949 	if (!done)
1950 		virtqueue_disable_cb(sq->vq);
1951 
1952 	__netif_tx_unlock(txq);
1953 
1954 	if (done) {
1955 		if (unlikely(virtqueue_poll(sq->vq, opaque))) {
1956 			if (napi_schedule_prep(napi)) {
1957 				__netif_tx_lock(txq, raw_smp_processor_id());
1958 				virtqueue_disable_cb(sq->vq);
1959 				__netif_tx_unlock(txq);
1960 				__napi_schedule(napi);
1961 			}
1962 		}
1963 	}
1964 
1965 	return 0;
1966 }
1967 
1968 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1969 {
1970 	struct virtio_net_hdr_mrg_rxbuf *hdr;
1971 	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1972 	struct virtnet_info *vi = sq->vq->vdev->priv;
1973 	int num_sg;
1974 	unsigned hdr_len = vi->hdr_len;
1975 	bool can_push;
1976 
1977 	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1978 
1979 	can_push = vi->any_header_sg &&
1980 		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1981 		!skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1982 	/* Even if we can, don't push here yet as this would skew
1983 	 * csum_start offset below. */
1984 	if (can_push)
1985 		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1986 	else
1987 		hdr = skb_vnet_hdr(skb);
1988 
1989 	if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1990 				    virtio_is_little_endian(vi->vdev), false,
1991 				    0))
1992 		return -EPROTO;
1993 
1994 	if (vi->mergeable_rx_bufs)
1995 		hdr->num_buffers = 0;
1996 
1997 	sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1998 	if (can_push) {
1999 		__skb_push(skb, hdr_len);
2000 		num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
2001 		if (unlikely(num_sg < 0))
2002 			return num_sg;
2003 		/* Pull header back to avoid skew in tx bytes calculations. */
2004 		__skb_pull(skb, hdr_len);
2005 	} else {
2006 		sg_set_buf(sq->sg, hdr, hdr_len);
2007 		num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
2008 		if (unlikely(num_sg < 0))
2009 			return num_sg;
2010 		num_sg++;
2011 	}
2012 	return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
2013 }
2014 
2015 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
2016 {
2017 	struct virtnet_info *vi = netdev_priv(dev);
2018 	int qnum = skb_get_queue_mapping(skb);
2019 	struct send_queue *sq = &vi->sq[qnum];
2020 	int err;
2021 	struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
2022 	bool kick = !netdev_xmit_more();
2023 	bool use_napi = sq->napi.weight;
2024 
2025 	/* Free up any pending old buffers before queueing new ones. */
2026 	do {
2027 		if (use_napi)
2028 			virtqueue_disable_cb(sq->vq);
2029 
2030 		free_old_xmit_skbs(sq, false);
2031 
2032 	} while (use_napi && kick &&
2033 	       unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
2034 
2035 	/* timestamp packet in software */
2036 	skb_tx_timestamp(skb);
2037 
2038 	/* Try to transmit */
2039 	err = xmit_skb(sq, skb);
2040 
2041 	/* This should not happen! */
2042 	if (unlikely(err)) {
2043 		dev->stats.tx_fifo_errors++;
2044 		if (net_ratelimit())
2045 			dev_warn(&dev->dev,
2046 				 "Unexpected TXQ (%d) queue failure: %d\n",
2047 				 qnum, err);
2048 		dev->stats.tx_dropped++;
2049 		dev_kfree_skb_any(skb);
2050 		return NETDEV_TX_OK;
2051 	}
2052 
2053 	/* Don't wait up for transmitted skbs to be freed. */
2054 	if (!use_napi) {
2055 		skb_orphan(skb);
2056 		nf_reset_ct(skb);
2057 	}
2058 
2059 	check_sq_full_and_disable(vi, dev, sq);
2060 
2061 	if (kick || netif_xmit_stopped(txq)) {
2062 		if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
2063 			u64_stats_update_begin(&sq->stats.syncp);
2064 			sq->stats.kicks++;
2065 			u64_stats_update_end(&sq->stats.syncp);
2066 		}
2067 	}
2068 
2069 	return NETDEV_TX_OK;
2070 }
2071 
2072 static int virtnet_rx_resize(struct virtnet_info *vi,
2073 			     struct receive_queue *rq, u32 ring_num)
2074 {
2075 	bool running = netif_running(vi->dev);
2076 	int err, qindex;
2077 
2078 	qindex = rq - vi->rq;
2079 
2080 	if (running)
2081 		napi_disable(&rq->napi);
2082 
2083 	err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
2084 	if (err)
2085 		netdev_err(vi->dev, "resize rx fail: rx queue index: %d err: %d\n", qindex, err);
2086 
2087 	if (!try_fill_recv(vi, rq, GFP_KERNEL))
2088 		schedule_delayed_work(&vi->refill, 0);
2089 
2090 	if (running)
2091 		virtnet_napi_enable(rq->vq, &rq->napi);
2092 	return err;
2093 }
2094 
2095 static int virtnet_tx_resize(struct virtnet_info *vi,
2096 			     struct send_queue *sq, u32 ring_num)
2097 {
2098 	bool running = netif_running(vi->dev);
2099 	struct netdev_queue *txq;
2100 	int err, qindex;
2101 
2102 	qindex = sq - vi->sq;
2103 
2104 	if (running)
2105 		virtnet_napi_tx_disable(&sq->napi);
2106 
2107 	txq = netdev_get_tx_queue(vi->dev, qindex);
2108 
2109 	/* 1. wait all ximt complete
2110 	 * 2. fix the race of netif_stop_subqueue() vs netif_start_subqueue()
2111 	 */
2112 	__netif_tx_lock_bh(txq);
2113 
2114 	/* Prevent rx poll from accessing sq. */
2115 	sq->reset = true;
2116 
2117 	/* Prevent the upper layer from trying to send packets. */
2118 	netif_stop_subqueue(vi->dev, qindex);
2119 
2120 	__netif_tx_unlock_bh(txq);
2121 
2122 	err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
2123 	if (err)
2124 		netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
2125 
2126 	__netif_tx_lock_bh(txq);
2127 	sq->reset = false;
2128 	netif_tx_wake_queue(txq);
2129 	__netif_tx_unlock_bh(txq);
2130 
2131 	if (running)
2132 		virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
2133 	return err;
2134 }
2135 
2136 /*
2137  * Send command via the control virtqueue and check status.  Commands
2138  * supported by the hypervisor, as indicated by feature bits, should
2139  * never fail unless improperly formatted.
2140  */
2141 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
2142 				 struct scatterlist *out)
2143 {
2144 	struct scatterlist *sgs[4], hdr, stat;
2145 	unsigned out_num = 0, tmp;
2146 	int ret;
2147 
2148 	/* Caller should know better */
2149 	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
2150 
2151 	vi->ctrl->status = ~0;
2152 	vi->ctrl->hdr.class = class;
2153 	vi->ctrl->hdr.cmd = cmd;
2154 	/* Add header */
2155 	sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
2156 	sgs[out_num++] = &hdr;
2157 
2158 	if (out)
2159 		sgs[out_num++] = out;
2160 
2161 	/* Add return status. */
2162 	sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
2163 	sgs[out_num] = &stat;
2164 
2165 	BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
2166 	ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
2167 	if (ret < 0) {
2168 		dev_warn(&vi->vdev->dev,
2169 			 "Failed to add sgs for command vq: %d\n.", ret);
2170 		return false;
2171 	}
2172 
2173 	if (unlikely(!virtqueue_kick(vi->cvq)))
2174 		return vi->ctrl->status == VIRTIO_NET_OK;
2175 
2176 	/* Spin for a response, the kick causes an ioport write, trapping
2177 	 * into the hypervisor, so the request should be handled immediately.
2178 	 */
2179 	while (!virtqueue_get_buf(vi->cvq, &tmp) &&
2180 	       !virtqueue_is_broken(vi->cvq))
2181 		cpu_relax();
2182 
2183 	return vi->ctrl->status == VIRTIO_NET_OK;
2184 }
2185 
2186 static int virtnet_set_mac_address(struct net_device *dev, void *p)
2187 {
2188 	struct virtnet_info *vi = netdev_priv(dev);
2189 	struct virtio_device *vdev = vi->vdev;
2190 	int ret;
2191 	struct sockaddr *addr;
2192 	struct scatterlist sg;
2193 
2194 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2195 		return -EOPNOTSUPP;
2196 
2197 	addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
2198 	if (!addr)
2199 		return -ENOMEM;
2200 
2201 	ret = eth_prepare_mac_addr_change(dev, addr);
2202 	if (ret)
2203 		goto out;
2204 
2205 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
2206 		sg_init_one(&sg, addr->sa_data, dev->addr_len);
2207 		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2208 					  VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
2209 			dev_warn(&vdev->dev,
2210 				 "Failed to set mac address by vq command.\n");
2211 			ret = -EINVAL;
2212 			goto out;
2213 		}
2214 	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
2215 		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
2216 		unsigned int i;
2217 
2218 		/* Naturally, this has an atomicity problem. */
2219 		for (i = 0; i < dev->addr_len; i++)
2220 			virtio_cwrite8(vdev,
2221 				       offsetof(struct virtio_net_config, mac) +
2222 				       i, addr->sa_data[i]);
2223 	}
2224 
2225 	eth_commit_mac_addr_change(dev, p);
2226 	ret = 0;
2227 
2228 out:
2229 	kfree(addr);
2230 	return ret;
2231 }
2232 
2233 static void virtnet_stats(struct net_device *dev,
2234 			  struct rtnl_link_stats64 *tot)
2235 {
2236 	struct virtnet_info *vi = netdev_priv(dev);
2237 	unsigned int start;
2238 	int i;
2239 
2240 	for (i = 0; i < vi->max_queue_pairs; i++) {
2241 		u64 tpackets, tbytes, terrors, rpackets, rbytes, rdrops;
2242 		struct receive_queue *rq = &vi->rq[i];
2243 		struct send_queue *sq = &vi->sq[i];
2244 
2245 		do {
2246 			start = u64_stats_fetch_begin(&sq->stats.syncp);
2247 			tpackets = sq->stats.packets;
2248 			tbytes   = sq->stats.bytes;
2249 			terrors  = sq->stats.tx_timeouts;
2250 		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2251 
2252 		do {
2253 			start = u64_stats_fetch_begin(&rq->stats.syncp);
2254 			rpackets = rq->stats.packets;
2255 			rbytes   = rq->stats.bytes;
2256 			rdrops   = rq->stats.drops;
2257 		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2258 
2259 		tot->rx_packets += rpackets;
2260 		tot->tx_packets += tpackets;
2261 		tot->rx_bytes   += rbytes;
2262 		tot->tx_bytes   += tbytes;
2263 		tot->rx_dropped += rdrops;
2264 		tot->tx_errors  += terrors;
2265 	}
2266 
2267 	tot->tx_dropped = dev->stats.tx_dropped;
2268 	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
2269 	tot->rx_length_errors = dev->stats.rx_length_errors;
2270 	tot->rx_frame_errors = dev->stats.rx_frame_errors;
2271 }
2272 
2273 static void virtnet_ack_link_announce(struct virtnet_info *vi)
2274 {
2275 	rtnl_lock();
2276 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
2277 				  VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
2278 		dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
2279 	rtnl_unlock();
2280 }
2281 
2282 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2283 {
2284 	struct scatterlist sg;
2285 	struct net_device *dev = vi->dev;
2286 
2287 	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
2288 		return 0;
2289 
2290 	vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
2291 	sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
2292 
2293 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2294 				  VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
2295 		dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
2296 			 queue_pairs);
2297 		return -EINVAL;
2298 	} else {
2299 		vi->curr_queue_pairs = queue_pairs;
2300 		/* virtnet_open() will refill when device is going to up. */
2301 		if (dev->flags & IFF_UP)
2302 			schedule_delayed_work(&vi->refill, 0);
2303 	}
2304 
2305 	return 0;
2306 }
2307 
2308 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
2309 {
2310 	int err;
2311 
2312 	rtnl_lock();
2313 	err = _virtnet_set_queues(vi, queue_pairs);
2314 	rtnl_unlock();
2315 	return err;
2316 }
2317 
2318 static int virtnet_close(struct net_device *dev)
2319 {
2320 	struct virtnet_info *vi = netdev_priv(dev);
2321 	int i;
2322 
2323 	/* Make sure NAPI doesn't schedule refill work */
2324 	disable_delayed_refill(vi);
2325 	/* Make sure refill_work doesn't re-enable napi! */
2326 	cancel_delayed_work_sync(&vi->refill);
2327 
2328 	for (i = 0; i < vi->max_queue_pairs; i++) {
2329 		virtnet_napi_tx_disable(&vi->sq[i].napi);
2330 		napi_disable(&vi->rq[i].napi);
2331 		xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
2332 	}
2333 
2334 	return 0;
2335 }
2336 
2337 static void virtnet_set_rx_mode(struct net_device *dev)
2338 {
2339 	struct virtnet_info *vi = netdev_priv(dev);
2340 	struct scatterlist sg[2];
2341 	struct virtio_net_ctrl_mac *mac_data;
2342 	struct netdev_hw_addr *ha;
2343 	int uc_count;
2344 	int mc_count;
2345 	void *buf;
2346 	int i;
2347 
2348 	/* We can't dynamically set ndo_set_rx_mode, so return gracefully */
2349 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
2350 		return;
2351 
2352 	vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
2353 	vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
2354 
2355 	sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
2356 
2357 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2358 				  VIRTIO_NET_CTRL_RX_PROMISC, sg))
2359 		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
2360 			 vi->ctrl->promisc ? "en" : "dis");
2361 
2362 	sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
2363 
2364 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
2365 				  VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
2366 		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
2367 			 vi->ctrl->allmulti ? "en" : "dis");
2368 
2369 	uc_count = netdev_uc_count(dev);
2370 	mc_count = netdev_mc_count(dev);
2371 	/* MAC filter - use one buffer for both lists */
2372 	buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
2373 		      (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
2374 	mac_data = buf;
2375 	if (!buf)
2376 		return;
2377 
2378 	sg_init_table(sg, 2);
2379 
2380 	/* Store the unicast list and count in the front of the buffer */
2381 	mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
2382 	i = 0;
2383 	netdev_for_each_uc_addr(ha, dev)
2384 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2385 
2386 	sg_set_buf(&sg[0], mac_data,
2387 		   sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
2388 
2389 	/* multicast list and count fill the end */
2390 	mac_data = (void *)&mac_data->macs[uc_count][0];
2391 
2392 	mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
2393 	i = 0;
2394 	netdev_for_each_mc_addr(ha, dev)
2395 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2396 
2397 	sg_set_buf(&sg[1], mac_data,
2398 		   sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
2399 
2400 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2401 				  VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
2402 		dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
2403 
2404 	kfree(buf);
2405 }
2406 
2407 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
2408 				   __be16 proto, u16 vid)
2409 {
2410 	struct virtnet_info *vi = netdev_priv(dev);
2411 	struct scatterlist sg;
2412 
2413 	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2414 	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2415 
2416 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2417 				  VIRTIO_NET_CTRL_VLAN_ADD, &sg))
2418 		dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
2419 	return 0;
2420 }
2421 
2422 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
2423 				    __be16 proto, u16 vid)
2424 {
2425 	struct virtnet_info *vi = netdev_priv(dev);
2426 	struct scatterlist sg;
2427 
2428 	vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2429 	sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2430 
2431 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2432 				  VIRTIO_NET_CTRL_VLAN_DEL, &sg))
2433 		dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
2434 	return 0;
2435 }
2436 
2437 static void virtnet_clean_affinity(struct virtnet_info *vi)
2438 {
2439 	int i;
2440 
2441 	if (vi->affinity_hint_set) {
2442 		for (i = 0; i < vi->max_queue_pairs; i++) {
2443 			virtqueue_set_affinity(vi->rq[i].vq, NULL);
2444 			virtqueue_set_affinity(vi->sq[i].vq, NULL);
2445 		}
2446 
2447 		vi->affinity_hint_set = false;
2448 	}
2449 }
2450 
2451 static void virtnet_set_affinity(struct virtnet_info *vi)
2452 {
2453 	cpumask_var_t mask;
2454 	int stragglers;
2455 	int group_size;
2456 	int i, j, cpu;
2457 	int num_cpu;
2458 	int stride;
2459 
2460 	if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
2461 		virtnet_clean_affinity(vi);
2462 		return;
2463 	}
2464 
2465 	num_cpu = num_online_cpus();
2466 	stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
2467 	stragglers = num_cpu >= vi->curr_queue_pairs ?
2468 			num_cpu % vi->curr_queue_pairs :
2469 			0;
2470 	cpu = cpumask_first(cpu_online_mask);
2471 
2472 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2473 		group_size = stride + (i < stragglers ? 1 : 0);
2474 
2475 		for (j = 0; j < group_size; j++) {
2476 			cpumask_set_cpu(cpu, mask);
2477 			cpu = cpumask_next_wrap(cpu, cpu_online_mask,
2478 						nr_cpu_ids, false);
2479 		}
2480 		virtqueue_set_affinity(vi->rq[i].vq, mask);
2481 		virtqueue_set_affinity(vi->sq[i].vq, mask);
2482 		__netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, XPS_CPUS);
2483 		cpumask_clear(mask);
2484 	}
2485 
2486 	vi->affinity_hint_set = true;
2487 	free_cpumask_var(mask);
2488 }
2489 
2490 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
2491 {
2492 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2493 						   node);
2494 	virtnet_set_affinity(vi);
2495 	return 0;
2496 }
2497 
2498 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
2499 {
2500 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2501 						   node_dead);
2502 	virtnet_set_affinity(vi);
2503 	return 0;
2504 }
2505 
2506 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
2507 {
2508 	struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2509 						   node);
2510 
2511 	virtnet_clean_affinity(vi);
2512 	return 0;
2513 }
2514 
2515 static enum cpuhp_state virtionet_online;
2516 
2517 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
2518 {
2519 	int ret;
2520 
2521 	ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2522 	if (ret)
2523 		return ret;
2524 	ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2525 					       &vi->node_dead);
2526 	if (!ret)
2527 		return ret;
2528 	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2529 	return ret;
2530 }
2531 
2532 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2533 {
2534 	cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2535 	cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2536 					    &vi->node_dead);
2537 }
2538 
2539 static void virtnet_get_ringparam(struct net_device *dev,
2540 				  struct ethtool_ringparam *ring,
2541 				  struct kernel_ethtool_ringparam *kernel_ring,
2542 				  struct netlink_ext_ack *extack)
2543 {
2544 	struct virtnet_info *vi = netdev_priv(dev);
2545 
2546 	ring->rx_max_pending = vi->rq[0].vq->num_max;
2547 	ring->tx_max_pending = vi->sq[0].vq->num_max;
2548 	ring->rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2549 	ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2550 }
2551 
2552 static int virtnet_set_ringparam(struct net_device *dev,
2553 				 struct ethtool_ringparam *ring,
2554 				 struct kernel_ethtool_ringparam *kernel_ring,
2555 				 struct netlink_ext_ack *extack)
2556 {
2557 	struct virtnet_info *vi = netdev_priv(dev);
2558 	u32 rx_pending, tx_pending;
2559 	struct receive_queue *rq;
2560 	struct send_queue *sq;
2561 	int i, err;
2562 
2563 	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
2564 		return -EINVAL;
2565 
2566 	rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2567 	tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2568 
2569 	if (ring->rx_pending == rx_pending &&
2570 	    ring->tx_pending == tx_pending)
2571 		return 0;
2572 
2573 	if (ring->rx_pending > vi->rq[0].vq->num_max)
2574 		return -EINVAL;
2575 
2576 	if (ring->tx_pending > vi->sq[0].vq->num_max)
2577 		return -EINVAL;
2578 
2579 	for (i = 0; i < vi->max_queue_pairs; i++) {
2580 		rq = vi->rq + i;
2581 		sq = vi->sq + i;
2582 
2583 		if (ring->tx_pending != tx_pending) {
2584 			err = virtnet_tx_resize(vi, sq, ring->tx_pending);
2585 			if (err)
2586 				return err;
2587 		}
2588 
2589 		if (ring->rx_pending != rx_pending) {
2590 			err = virtnet_rx_resize(vi, rq, ring->rx_pending);
2591 			if (err)
2592 				return err;
2593 		}
2594 	}
2595 
2596 	return 0;
2597 }
2598 
2599 static bool virtnet_commit_rss_command(struct virtnet_info *vi)
2600 {
2601 	struct net_device *dev = vi->dev;
2602 	struct scatterlist sgs[4];
2603 	unsigned int sg_buf_size;
2604 
2605 	/* prepare sgs */
2606 	sg_init_table(sgs, 4);
2607 
2608 	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, indirection_table);
2609 	sg_set_buf(&sgs[0], &vi->ctrl->rss, sg_buf_size);
2610 
2611 	sg_buf_size = sizeof(uint16_t) * (vi->ctrl->rss.indirection_table_mask + 1);
2612 	sg_set_buf(&sgs[1], vi->ctrl->rss.indirection_table, sg_buf_size);
2613 
2614 	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, key)
2615 			- offsetof(struct virtio_net_ctrl_rss, max_tx_vq);
2616 	sg_set_buf(&sgs[2], &vi->ctrl->rss.max_tx_vq, sg_buf_size);
2617 
2618 	sg_buf_size = vi->rss_key_size;
2619 	sg_set_buf(&sgs[3], vi->ctrl->rss.key, sg_buf_size);
2620 
2621 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
2622 				  vi->has_rss ? VIRTIO_NET_CTRL_MQ_RSS_CONFIG
2623 				  : VIRTIO_NET_CTRL_MQ_HASH_CONFIG, sgs)) {
2624 		dev_warn(&dev->dev, "VIRTIONET issue with committing RSS sgs\n");
2625 		return false;
2626 	}
2627 	return true;
2628 }
2629 
2630 static void virtnet_init_default_rss(struct virtnet_info *vi)
2631 {
2632 	u32 indir_val = 0;
2633 	int i = 0;
2634 
2635 	vi->ctrl->rss.hash_types = vi->rss_hash_types_supported;
2636 	vi->rss_hash_types_saved = vi->rss_hash_types_supported;
2637 	vi->ctrl->rss.indirection_table_mask = vi->rss_indir_table_size
2638 						? vi->rss_indir_table_size - 1 : 0;
2639 	vi->ctrl->rss.unclassified_queue = 0;
2640 
2641 	for (; i < vi->rss_indir_table_size; ++i) {
2642 		indir_val = ethtool_rxfh_indir_default(i, vi->curr_queue_pairs);
2643 		vi->ctrl->rss.indirection_table[i] = indir_val;
2644 	}
2645 
2646 	vi->ctrl->rss.max_tx_vq = vi->curr_queue_pairs;
2647 	vi->ctrl->rss.hash_key_length = vi->rss_key_size;
2648 
2649 	netdev_rss_key_fill(vi->ctrl->rss.key, vi->rss_key_size);
2650 }
2651 
2652 static void virtnet_get_hashflow(const struct virtnet_info *vi, struct ethtool_rxnfc *info)
2653 {
2654 	info->data = 0;
2655 	switch (info->flow_type) {
2656 	case TCP_V4_FLOW:
2657 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
2658 			info->data = RXH_IP_SRC | RXH_IP_DST |
2659 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2660 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2661 			info->data = RXH_IP_SRC | RXH_IP_DST;
2662 		}
2663 		break;
2664 	case TCP_V6_FLOW:
2665 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
2666 			info->data = RXH_IP_SRC | RXH_IP_DST |
2667 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2668 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2669 			info->data = RXH_IP_SRC | RXH_IP_DST;
2670 		}
2671 		break;
2672 	case UDP_V4_FLOW:
2673 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
2674 			info->data = RXH_IP_SRC | RXH_IP_DST |
2675 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2676 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
2677 			info->data = RXH_IP_SRC | RXH_IP_DST;
2678 		}
2679 		break;
2680 	case UDP_V6_FLOW:
2681 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
2682 			info->data = RXH_IP_SRC | RXH_IP_DST |
2683 						 RXH_L4_B_0_1 | RXH_L4_B_2_3;
2684 		} else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
2685 			info->data = RXH_IP_SRC | RXH_IP_DST;
2686 		}
2687 		break;
2688 	case IPV4_FLOW:
2689 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4)
2690 			info->data = RXH_IP_SRC | RXH_IP_DST;
2691 
2692 		break;
2693 	case IPV6_FLOW:
2694 		if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6)
2695 			info->data = RXH_IP_SRC | RXH_IP_DST;
2696 
2697 		break;
2698 	default:
2699 		info->data = 0;
2700 		break;
2701 	}
2702 }
2703 
2704 static bool virtnet_set_hashflow(struct virtnet_info *vi, struct ethtool_rxnfc *info)
2705 {
2706 	u32 new_hashtypes = vi->rss_hash_types_saved;
2707 	bool is_disable = info->data & RXH_DISCARD;
2708 	bool is_l4 = info->data == (RXH_IP_SRC | RXH_IP_DST | RXH_L4_B_0_1 | RXH_L4_B_2_3);
2709 
2710 	/* supports only 'sd', 'sdfn' and 'r' */
2711 	if (!((info->data == (RXH_IP_SRC | RXH_IP_DST)) | is_l4 | is_disable))
2712 		return false;
2713 
2714 	switch (info->flow_type) {
2715 	case TCP_V4_FLOW:
2716 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_TCPv4);
2717 		if (!is_disable)
2718 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2719 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv4 : 0);
2720 		break;
2721 	case UDP_V4_FLOW:
2722 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_UDPv4);
2723 		if (!is_disable)
2724 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4
2725 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv4 : 0);
2726 		break;
2727 	case IPV4_FLOW:
2728 		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2729 		if (!is_disable)
2730 			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv4;
2731 		break;
2732 	case TCP_V6_FLOW:
2733 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_TCPv6);
2734 		if (!is_disable)
2735 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2736 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_TCPv6 : 0);
2737 		break;
2738 	case UDP_V6_FLOW:
2739 		new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv6 | VIRTIO_NET_RSS_HASH_TYPE_UDPv6);
2740 		if (!is_disable)
2741 			new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6
2742 				| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv6 : 0);
2743 		break;
2744 	case IPV6_FLOW:
2745 		new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2746 		if (!is_disable)
2747 			new_hashtypes = VIRTIO_NET_RSS_HASH_TYPE_IPv6;
2748 		break;
2749 	default:
2750 		/* unsupported flow */
2751 		return false;
2752 	}
2753 
2754 	/* if unsupported hashtype was set */
2755 	if (new_hashtypes != (new_hashtypes & vi->rss_hash_types_supported))
2756 		return false;
2757 
2758 	if (new_hashtypes != vi->rss_hash_types_saved) {
2759 		vi->rss_hash_types_saved = new_hashtypes;
2760 		vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
2761 		if (vi->dev->features & NETIF_F_RXHASH)
2762 			return virtnet_commit_rss_command(vi);
2763 	}
2764 
2765 	return true;
2766 }
2767 
2768 static void virtnet_get_drvinfo(struct net_device *dev,
2769 				struct ethtool_drvinfo *info)
2770 {
2771 	struct virtnet_info *vi = netdev_priv(dev);
2772 	struct virtio_device *vdev = vi->vdev;
2773 
2774 	strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2775 	strscpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2776 	strscpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2777 
2778 }
2779 
2780 /* TODO: Eliminate OOO packets during switching */
2781 static int virtnet_set_channels(struct net_device *dev,
2782 				struct ethtool_channels *channels)
2783 {
2784 	struct virtnet_info *vi = netdev_priv(dev);
2785 	u16 queue_pairs = channels->combined_count;
2786 	int err;
2787 
2788 	/* We don't support separate rx/tx channels.
2789 	 * We don't allow setting 'other' channels.
2790 	 */
2791 	if (channels->rx_count || channels->tx_count || channels->other_count)
2792 		return -EINVAL;
2793 
2794 	if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2795 		return -EINVAL;
2796 
2797 	/* For now we don't support modifying channels while XDP is loaded
2798 	 * also when XDP is loaded all RX queues have XDP programs so we only
2799 	 * need to check a single RX queue.
2800 	 */
2801 	if (vi->rq[0].xdp_prog)
2802 		return -EINVAL;
2803 
2804 	cpus_read_lock();
2805 	err = _virtnet_set_queues(vi, queue_pairs);
2806 	if (err) {
2807 		cpus_read_unlock();
2808 		goto err;
2809 	}
2810 	virtnet_set_affinity(vi);
2811 	cpus_read_unlock();
2812 
2813 	netif_set_real_num_tx_queues(dev, queue_pairs);
2814 	netif_set_real_num_rx_queues(dev, queue_pairs);
2815  err:
2816 	return err;
2817 }
2818 
2819 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2820 {
2821 	struct virtnet_info *vi = netdev_priv(dev);
2822 	unsigned int i, j;
2823 	u8 *p = data;
2824 
2825 	switch (stringset) {
2826 	case ETH_SS_STATS:
2827 		for (i = 0; i < vi->curr_queue_pairs; i++) {
2828 			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++)
2829 				ethtool_sprintf(&p, "rx_queue_%u_%s", i,
2830 						virtnet_rq_stats_desc[j].desc);
2831 		}
2832 
2833 		for (i = 0; i < vi->curr_queue_pairs; i++) {
2834 			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++)
2835 				ethtool_sprintf(&p, "tx_queue_%u_%s", i,
2836 						virtnet_sq_stats_desc[j].desc);
2837 		}
2838 		break;
2839 	}
2840 }
2841 
2842 static int virtnet_get_sset_count(struct net_device *dev, int sset)
2843 {
2844 	struct virtnet_info *vi = netdev_priv(dev);
2845 
2846 	switch (sset) {
2847 	case ETH_SS_STATS:
2848 		return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2849 					       VIRTNET_SQ_STATS_LEN);
2850 	default:
2851 		return -EOPNOTSUPP;
2852 	}
2853 }
2854 
2855 static void virtnet_get_ethtool_stats(struct net_device *dev,
2856 				      struct ethtool_stats *stats, u64 *data)
2857 {
2858 	struct virtnet_info *vi = netdev_priv(dev);
2859 	unsigned int idx = 0, start, i, j;
2860 	const u8 *stats_base;
2861 	size_t offset;
2862 
2863 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2864 		struct receive_queue *rq = &vi->rq[i];
2865 
2866 		stats_base = (u8 *)&rq->stats;
2867 		do {
2868 			start = u64_stats_fetch_begin(&rq->stats.syncp);
2869 			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2870 				offset = virtnet_rq_stats_desc[j].offset;
2871 				data[idx + j] = *(u64 *)(stats_base + offset);
2872 			}
2873 		} while (u64_stats_fetch_retry(&rq->stats.syncp, start));
2874 		idx += VIRTNET_RQ_STATS_LEN;
2875 	}
2876 
2877 	for (i = 0; i < vi->curr_queue_pairs; i++) {
2878 		struct send_queue *sq = &vi->sq[i];
2879 
2880 		stats_base = (u8 *)&sq->stats;
2881 		do {
2882 			start = u64_stats_fetch_begin(&sq->stats.syncp);
2883 			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2884 				offset = virtnet_sq_stats_desc[j].offset;
2885 				data[idx + j] = *(u64 *)(stats_base + offset);
2886 			}
2887 		} while (u64_stats_fetch_retry(&sq->stats.syncp, start));
2888 		idx += VIRTNET_SQ_STATS_LEN;
2889 	}
2890 }
2891 
2892 static void virtnet_get_channels(struct net_device *dev,
2893 				 struct ethtool_channels *channels)
2894 {
2895 	struct virtnet_info *vi = netdev_priv(dev);
2896 
2897 	channels->combined_count = vi->curr_queue_pairs;
2898 	channels->max_combined = vi->max_queue_pairs;
2899 	channels->max_other = 0;
2900 	channels->rx_count = 0;
2901 	channels->tx_count = 0;
2902 	channels->other_count = 0;
2903 }
2904 
2905 static int virtnet_set_link_ksettings(struct net_device *dev,
2906 				      const struct ethtool_link_ksettings *cmd)
2907 {
2908 	struct virtnet_info *vi = netdev_priv(dev);
2909 
2910 	return ethtool_virtdev_set_link_ksettings(dev, cmd,
2911 						  &vi->speed, &vi->duplex);
2912 }
2913 
2914 static int virtnet_get_link_ksettings(struct net_device *dev,
2915 				      struct ethtool_link_ksettings *cmd)
2916 {
2917 	struct virtnet_info *vi = netdev_priv(dev);
2918 
2919 	cmd->base.speed = vi->speed;
2920 	cmd->base.duplex = vi->duplex;
2921 	cmd->base.port = PORT_OTHER;
2922 
2923 	return 0;
2924 }
2925 
2926 static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
2927 				       struct ethtool_coalesce *ec)
2928 {
2929 	struct scatterlist sgs_tx, sgs_rx;
2930 	struct virtio_net_ctrl_coal_tx coal_tx;
2931 	struct virtio_net_ctrl_coal_rx coal_rx;
2932 
2933 	coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
2934 	coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
2935 	sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
2936 
2937 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2938 				  VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
2939 				  &sgs_tx))
2940 		return -EINVAL;
2941 
2942 	/* Save parameters */
2943 	vi->tx_usecs = ec->tx_coalesce_usecs;
2944 	vi->tx_max_packets = ec->tx_max_coalesced_frames;
2945 
2946 	coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
2947 	coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
2948 	sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
2949 
2950 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
2951 				  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
2952 				  &sgs_rx))
2953 		return -EINVAL;
2954 
2955 	/* Save parameters */
2956 	vi->rx_usecs = ec->rx_coalesce_usecs;
2957 	vi->rx_max_packets = ec->rx_max_coalesced_frames;
2958 
2959 	return 0;
2960 }
2961 
2962 static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
2963 {
2964 	/* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
2965 	 * feature is negotiated.
2966 	 */
2967 	if (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs)
2968 		return -EOPNOTSUPP;
2969 
2970 	if (ec->tx_max_coalesced_frames > 1 ||
2971 	    ec->rx_max_coalesced_frames != 1)
2972 		return -EINVAL;
2973 
2974 	return 0;
2975 }
2976 
2977 static int virtnet_set_coalesce(struct net_device *dev,
2978 				struct ethtool_coalesce *ec,
2979 				struct kernel_ethtool_coalesce *kernel_coal,
2980 				struct netlink_ext_ack *extack)
2981 {
2982 	struct virtnet_info *vi = netdev_priv(dev);
2983 	int ret, i, napi_weight;
2984 	bool update_napi = false;
2985 
2986 	/* Can't change NAPI weight if the link is up */
2987 	napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2988 	if (napi_weight ^ vi->sq[0].napi.weight) {
2989 		if (dev->flags & IFF_UP)
2990 			return -EBUSY;
2991 		else
2992 			update_napi = true;
2993 	}
2994 
2995 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL))
2996 		ret = virtnet_send_notf_coal_cmds(vi, ec);
2997 	else
2998 		ret = virtnet_coal_params_supported(ec);
2999 
3000 	if (ret)
3001 		return ret;
3002 
3003 	if (update_napi) {
3004 		for (i = 0; i < vi->max_queue_pairs; i++)
3005 			vi->sq[i].napi.weight = napi_weight;
3006 	}
3007 
3008 	return ret;
3009 }
3010 
3011 static int virtnet_get_coalesce(struct net_device *dev,
3012 				struct ethtool_coalesce *ec,
3013 				struct kernel_ethtool_coalesce *kernel_coal,
3014 				struct netlink_ext_ack *extack)
3015 {
3016 	struct virtnet_info *vi = netdev_priv(dev);
3017 
3018 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
3019 		ec->rx_coalesce_usecs = vi->rx_usecs;
3020 		ec->tx_coalesce_usecs = vi->tx_usecs;
3021 		ec->tx_max_coalesced_frames = vi->tx_max_packets;
3022 		ec->rx_max_coalesced_frames = vi->rx_max_packets;
3023 	} else {
3024 		ec->rx_max_coalesced_frames = 1;
3025 
3026 		if (vi->sq[0].napi.weight)
3027 			ec->tx_max_coalesced_frames = 1;
3028 	}
3029 
3030 	return 0;
3031 }
3032 
3033 static void virtnet_init_settings(struct net_device *dev)
3034 {
3035 	struct virtnet_info *vi = netdev_priv(dev);
3036 
3037 	vi->speed = SPEED_UNKNOWN;
3038 	vi->duplex = DUPLEX_UNKNOWN;
3039 }
3040 
3041 static void virtnet_update_settings(struct virtnet_info *vi)
3042 {
3043 	u32 speed;
3044 	u8 duplex;
3045 
3046 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
3047 		return;
3048 
3049 	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
3050 
3051 	if (ethtool_validate_speed(speed))
3052 		vi->speed = speed;
3053 
3054 	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
3055 
3056 	if (ethtool_validate_duplex(duplex))
3057 		vi->duplex = duplex;
3058 }
3059 
3060 static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
3061 {
3062 	return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
3063 }
3064 
3065 static u32 virtnet_get_rxfh_indir_size(struct net_device *dev)
3066 {
3067 	return ((struct virtnet_info *)netdev_priv(dev))->rss_indir_table_size;
3068 }
3069 
3070 static int virtnet_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfunc)
3071 {
3072 	struct virtnet_info *vi = netdev_priv(dev);
3073 	int i;
3074 
3075 	if (indir) {
3076 		for (i = 0; i < vi->rss_indir_table_size; ++i)
3077 			indir[i] = vi->ctrl->rss.indirection_table[i];
3078 	}
3079 
3080 	if (key)
3081 		memcpy(key, vi->ctrl->rss.key, vi->rss_key_size);
3082 
3083 	if (hfunc)
3084 		*hfunc = ETH_RSS_HASH_TOP;
3085 
3086 	return 0;
3087 }
3088 
3089 static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key, const u8 hfunc)
3090 {
3091 	struct virtnet_info *vi = netdev_priv(dev);
3092 	int i;
3093 
3094 	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
3095 		return -EOPNOTSUPP;
3096 
3097 	if (indir) {
3098 		for (i = 0; i < vi->rss_indir_table_size; ++i)
3099 			vi->ctrl->rss.indirection_table[i] = indir[i];
3100 	}
3101 	if (key)
3102 		memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);
3103 
3104 	virtnet_commit_rss_command(vi);
3105 
3106 	return 0;
3107 }
3108 
3109 static int virtnet_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info, u32 *rule_locs)
3110 {
3111 	struct virtnet_info *vi = netdev_priv(dev);
3112 	int rc = 0;
3113 
3114 	switch (info->cmd) {
3115 	case ETHTOOL_GRXRINGS:
3116 		info->data = vi->curr_queue_pairs;
3117 		break;
3118 	case ETHTOOL_GRXFH:
3119 		virtnet_get_hashflow(vi, info);
3120 		break;
3121 	default:
3122 		rc = -EOPNOTSUPP;
3123 	}
3124 
3125 	return rc;
3126 }
3127 
3128 static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info)
3129 {
3130 	struct virtnet_info *vi = netdev_priv(dev);
3131 	int rc = 0;
3132 
3133 	switch (info->cmd) {
3134 	case ETHTOOL_SRXFH:
3135 		if (!virtnet_set_hashflow(vi, info))
3136 			rc = -EINVAL;
3137 
3138 		break;
3139 	default:
3140 		rc = -EOPNOTSUPP;
3141 	}
3142 
3143 	return rc;
3144 }
3145 
3146 static const struct ethtool_ops virtnet_ethtool_ops = {
3147 	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
3148 		ETHTOOL_COALESCE_USECS,
3149 	.get_drvinfo = virtnet_get_drvinfo,
3150 	.get_link = ethtool_op_get_link,
3151 	.get_ringparam = virtnet_get_ringparam,
3152 	.set_ringparam = virtnet_set_ringparam,
3153 	.get_strings = virtnet_get_strings,
3154 	.get_sset_count = virtnet_get_sset_count,
3155 	.get_ethtool_stats = virtnet_get_ethtool_stats,
3156 	.set_channels = virtnet_set_channels,
3157 	.get_channels = virtnet_get_channels,
3158 	.get_ts_info = ethtool_op_get_ts_info,
3159 	.get_link_ksettings = virtnet_get_link_ksettings,
3160 	.set_link_ksettings = virtnet_set_link_ksettings,
3161 	.set_coalesce = virtnet_set_coalesce,
3162 	.get_coalesce = virtnet_get_coalesce,
3163 	.get_rxfh_key_size = virtnet_get_rxfh_key_size,
3164 	.get_rxfh_indir_size = virtnet_get_rxfh_indir_size,
3165 	.get_rxfh = virtnet_get_rxfh,
3166 	.set_rxfh = virtnet_set_rxfh,
3167 	.get_rxnfc = virtnet_get_rxnfc,
3168 	.set_rxnfc = virtnet_set_rxnfc,
3169 };
3170 
3171 static void virtnet_freeze_down(struct virtio_device *vdev)
3172 {
3173 	struct virtnet_info *vi = vdev->priv;
3174 
3175 	/* Make sure no work handler is accessing the device */
3176 	flush_work(&vi->config_work);
3177 
3178 	netif_tx_lock_bh(vi->dev);
3179 	netif_device_detach(vi->dev);
3180 	netif_tx_unlock_bh(vi->dev);
3181 	if (netif_running(vi->dev))
3182 		virtnet_close(vi->dev);
3183 }
3184 
3185 static int init_vqs(struct virtnet_info *vi);
3186 
3187 static int virtnet_restore_up(struct virtio_device *vdev)
3188 {
3189 	struct virtnet_info *vi = vdev->priv;
3190 	int err;
3191 
3192 	err = init_vqs(vi);
3193 	if (err)
3194 		return err;
3195 
3196 	virtio_device_ready(vdev);
3197 
3198 	enable_delayed_refill(vi);
3199 
3200 	if (netif_running(vi->dev)) {
3201 		err = virtnet_open(vi->dev);
3202 		if (err)
3203 			return err;
3204 	}
3205 
3206 	netif_tx_lock_bh(vi->dev);
3207 	netif_device_attach(vi->dev);
3208 	netif_tx_unlock_bh(vi->dev);
3209 	return err;
3210 }
3211 
3212 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
3213 {
3214 	struct scatterlist sg;
3215 	vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
3216 
3217 	sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
3218 
3219 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
3220 				  VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
3221 		dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
3222 		return -EINVAL;
3223 	}
3224 
3225 	return 0;
3226 }
3227 
3228 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
3229 {
3230 	u64 offloads = 0;
3231 
3232 	if (!vi->guest_offloads)
3233 		return 0;
3234 
3235 	return virtnet_set_guest_offloads(vi, offloads);
3236 }
3237 
3238 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
3239 {
3240 	u64 offloads = vi->guest_offloads;
3241 
3242 	if (!vi->guest_offloads)
3243 		return 0;
3244 
3245 	return virtnet_set_guest_offloads(vi, offloads);
3246 }
3247 
3248 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
3249 			   struct netlink_ext_ack *extack)
3250 {
3251 	unsigned int room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM +
3252 					   sizeof(struct skb_shared_info));
3253 	unsigned int max_sz = PAGE_SIZE - room - ETH_HLEN;
3254 	struct virtnet_info *vi = netdev_priv(dev);
3255 	struct bpf_prog *old_prog;
3256 	u16 xdp_qp = 0, curr_qp;
3257 	int i, err;
3258 
3259 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
3260 	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3261 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3262 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3263 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3264 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM) ||
3265 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) ||
3266 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6))) {
3267 		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
3268 		return -EOPNOTSUPP;
3269 	}
3270 
3271 	if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
3272 		NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
3273 		return -EINVAL;
3274 	}
3275 
3276 	if (prog && !prog->aux->xdp_has_frags && dev->mtu > max_sz) {
3277 		NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP without frags");
3278 		netdev_warn(dev, "single-buffer XDP requires MTU less than %u\n", max_sz);
3279 		return -EINVAL;
3280 	}
3281 
3282 	curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
3283 	if (prog)
3284 		xdp_qp = nr_cpu_ids;
3285 
3286 	/* XDP requires extra queues for XDP_TX */
3287 	if (curr_qp + xdp_qp > vi->max_queue_pairs) {
3288 		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",
3289 				 curr_qp + xdp_qp, vi->max_queue_pairs);
3290 		xdp_qp = 0;
3291 	}
3292 
3293 	old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
3294 	if (!prog && !old_prog)
3295 		return 0;
3296 
3297 	if (prog)
3298 		bpf_prog_add(prog, vi->max_queue_pairs - 1);
3299 
3300 	/* Make sure NAPI is not using any XDP TX queues for RX. */
3301 	if (netif_running(dev)) {
3302 		for (i = 0; i < vi->max_queue_pairs; i++) {
3303 			napi_disable(&vi->rq[i].napi);
3304 			virtnet_napi_tx_disable(&vi->sq[i].napi);
3305 		}
3306 	}
3307 
3308 	if (!prog) {
3309 		for (i = 0; i < vi->max_queue_pairs; i++) {
3310 			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3311 			if (i == 0)
3312 				virtnet_restore_guest_offloads(vi);
3313 		}
3314 		synchronize_net();
3315 	}
3316 
3317 	err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
3318 	if (err)
3319 		goto err;
3320 	netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
3321 	vi->xdp_queue_pairs = xdp_qp;
3322 
3323 	if (prog) {
3324 		vi->xdp_enabled = true;
3325 		for (i = 0; i < vi->max_queue_pairs; i++) {
3326 			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
3327 			if (i == 0 && !old_prog)
3328 				virtnet_clear_guest_offloads(vi);
3329 		}
3330 		if (!old_prog)
3331 			xdp_features_set_redirect_target(dev, true);
3332 	} else {
3333 		xdp_features_clear_redirect_target(dev);
3334 		vi->xdp_enabled = false;
3335 	}
3336 
3337 	for (i = 0; i < vi->max_queue_pairs; i++) {
3338 		if (old_prog)
3339 			bpf_prog_put(old_prog);
3340 		if (netif_running(dev)) {
3341 			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3342 			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3343 					       &vi->sq[i].napi);
3344 		}
3345 	}
3346 
3347 	return 0;
3348 
3349 err:
3350 	if (!prog) {
3351 		virtnet_clear_guest_offloads(vi);
3352 		for (i = 0; i < vi->max_queue_pairs; i++)
3353 			rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
3354 	}
3355 
3356 	if (netif_running(dev)) {
3357 		for (i = 0; i < vi->max_queue_pairs; i++) {
3358 			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
3359 			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
3360 					       &vi->sq[i].napi);
3361 		}
3362 	}
3363 	if (prog)
3364 		bpf_prog_sub(prog, vi->max_queue_pairs - 1);
3365 	return err;
3366 }
3367 
3368 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
3369 {
3370 	switch (xdp->command) {
3371 	case XDP_SETUP_PROG:
3372 		return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
3373 	default:
3374 		return -EINVAL;
3375 	}
3376 }
3377 
3378 static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
3379 				      size_t len)
3380 {
3381 	struct virtnet_info *vi = netdev_priv(dev);
3382 	int ret;
3383 
3384 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
3385 		return -EOPNOTSUPP;
3386 
3387 	ret = snprintf(buf, len, "sby");
3388 	if (ret >= len)
3389 		return -EOPNOTSUPP;
3390 
3391 	return 0;
3392 }
3393 
3394 static int virtnet_set_features(struct net_device *dev,
3395 				netdev_features_t features)
3396 {
3397 	struct virtnet_info *vi = netdev_priv(dev);
3398 	u64 offloads;
3399 	int err;
3400 
3401 	if ((dev->features ^ features) & NETIF_F_GRO_HW) {
3402 		if (vi->xdp_enabled)
3403 			return -EBUSY;
3404 
3405 		if (features & NETIF_F_GRO_HW)
3406 			offloads = vi->guest_offloads_capable;
3407 		else
3408 			offloads = vi->guest_offloads_capable &
3409 				   ~GUEST_OFFLOAD_GRO_HW_MASK;
3410 
3411 		err = virtnet_set_guest_offloads(vi, offloads);
3412 		if (err)
3413 			return err;
3414 		vi->guest_offloads = offloads;
3415 	}
3416 
3417 	if ((dev->features ^ features) & NETIF_F_RXHASH) {
3418 		if (features & NETIF_F_RXHASH)
3419 			vi->ctrl->rss.hash_types = vi->rss_hash_types_saved;
3420 		else
3421 			vi->ctrl->rss.hash_types = VIRTIO_NET_HASH_REPORT_NONE;
3422 
3423 		if (!virtnet_commit_rss_command(vi))
3424 			return -EINVAL;
3425 	}
3426 
3427 	return 0;
3428 }
3429 
3430 static void virtnet_tx_timeout(struct net_device *dev, unsigned int txqueue)
3431 {
3432 	struct virtnet_info *priv = netdev_priv(dev);
3433 	struct send_queue *sq = &priv->sq[txqueue];
3434 	struct netdev_queue *txq = netdev_get_tx_queue(dev, txqueue);
3435 
3436 	u64_stats_update_begin(&sq->stats.syncp);
3437 	sq->stats.tx_timeouts++;
3438 	u64_stats_update_end(&sq->stats.syncp);
3439 
3440 	netdev_err(dev, "TX timeout on queue: %u, sq: %s, vq: 0x%x, name: %s, %u usecs ago\n",
3441 		   txqueue, sq->name, sq->vq->index, sq->vq->name,
3442 		   jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start)));
3443 }
3444 
3445 static const struct net_device_ops virtnet_netdev = {
3446 	.ndo_open            = virtnet_open,
3447 	.ndo_stop   	     = virtnet_close,
3448 	.ndo_start_xmit      = start_xmit,
3449 	.ndo_validate_addr   = eth_validate_addr,
3450 	.ndo_set_mac_address = virtnet_set_mac_address,
3451 	.ndo_set_rx_mode     = virtnet_set_rx_mode,
3452 	.ndo_get_stats64     = virtnet_stats,
3453 	.ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
3454 	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
3455 	.ndo_bpf		= virtnet_xdp,
3456 	.ndo_xdp_xmit		= virtnet_xdp_xmit,
3457 	.ndo_features_check	= passthru_features_check,
3458 	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,
3459 	.ndo_set_features	= virtnet_set_features,
3460 	.ndo_tx_timeout		= virtnet_tx_timeout,
3461 };
3462 
3463 static void virtnet_config_changed_work(struct work_struct *work)
3464 {
3465 	struct virtnet_info *vi =
3466 		container_of(work, struct virtnet_info, config_work);
3467 	u16 v;
3468 
3469 	if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
3470 				 struct virtio_net_config, status, &v) < 0)
3471 		return;
3472 
3473 	if (v & VIRTIO_NET_S_ANNOUNCE) {
3474 		netdev_notify_peers(vi->dev);
3475 		virtnet_ack_link_announce(vi);
3476 	}
3477 
3478 	/* Ignore unknown (future) status bits */
3479 	v &= VIRTIO_NET_S_LINK_UP;
3480 
3481 	if (vi->status == v)
3482 		return;
3483 
3484 	vi->status = v;
3485 
3486 	if (vi->status & VIRTIO_NET_S_LINK_UP) {
3487 		virtnet_update_settings(vi);
3488 		netif_carrier_on(vi->dev);
3489 		netif_tx_wake_all_queues(vi->dev);
3490 	} else {
3491 		netif_carrier_off(vi->dev);
3492 		netif_tx_stop_all_queues(vi->dev);
3493 	}
3494 }
3495 
3496 static void virtnet_config_changed(struct virtio_device *vdev)
3497 {
3498 	struct virtnet_info *vi = vdev->priv;
3499 
3500 	schedule_work(&vi->config_work);
3501 }
3502 
3503 static void virtnet_free_queues(struct virtnet_info *vi)
3504 {
3505 	int i;
3506 
3507 	for (i = 0; i < vi->max_queue_pairs; i++) {
3508 		__netif_napi_del(&vi->rq[i].napi);
3509 		__netif_napi_del(&vi->sq[i].napi);
3510 	}
3511 
3512 	/* We called __netif_napi_del(),
3513 	 * we need to respect an RCU grace period before freeing vi->rq
3514 	 */
3515 	synchronize_net();
3516 
3517 	kfree(vi->rq);
3518 	kfree(vi->sq);
3519 	kfree(vi->ctrl);
3520 }
3521 
3522 static void _free_receive_bufs(struct virtnet_info *vi)
3523 {
3524 	struct bpf_prog *old_prog;
3525 	int i;
3526 
3527 	for (i = 0; i < vi->max_queue_pairs; i++) {
3528 		while (vi->rq[i].pages)
3529 			__free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
3530 
3531 		old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
3532 		RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
3533 		if (old_prog)
3534 			bpf_prog_put(old_prog);
3535 	}
3536 }
3537 
3538 static void free_receive_bufs(struct virtnet_info *vi)
3539 {
3540 	rtnl_lock();
3541 	_free_receive_bufs(vi);
3542 	rtnl_unlock();
3543 }
3544 
3545 static void free_receive_page_frags(struct virtnet_info *vi)
3546 {
3547 	int i;
3548 	for (i = 0; i < vi->max_queue_pairs; i++)
3549 		if (vi->rq[i].alloc_frag.page)
3550 			put_page(vi->rq[i].alloc_frag.page);
3551 }
3552 
3553 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
3554 {
3555 	if (!is_xdp_frame(buf))
3556 		dev_kfree_skb(buf);
3557 	else
3558 		xdp_return_frame(ptr_to_xdp(buf));
3559 }
3560 
3561 static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf)
3562 {
3563 	struct virtnet_info *vi = vq->vdev->priv;
3564 	int i = vq2rxq(vq);
3565 
3566 	if (vi->mergeable_rx_bufs)
3567 		put_page(virt_to_head_page(buf));
3568 	else if (vi->big_packets)
3569 		give_pages(&vi->rq[i], buf);
3570 	else
3571 		put_page(virt_to_head_page(buf));
3572 }
3573 
3574 static void free_unused_bufs(struct virtnet_info *vi)
3575 {
3576 	void *buf;
3577 	int i;
3578 
3579 	for (i = 0; i < vi->max_queue_pairs; i++) {
3580 		struct virtqueue *vq = vi->sq[i].vq;
3581 		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3582 			virtnet_sq_free_unused_buf(vq, buf);
3583 		cond_resched();
3584 	}
3585 
3586 	for (i = 0; i < vi->max_queue_pairs; i++) {
3587 		struct virtqueue *vq = vi->rq[i].vq;
3588 		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
3589 			virtnet_rq_free_unused_buf(vq, buf);
3590 		cond_resched();
3591 	}
3592 }
3593 
3594 static void virtnet_del_vqs(struct virtnet_info *vi)
3595 {
3596 	struct virtio_device *vdev = vi->vdev;
3597 
3598 	virtnet_clean_affinity(vi);
3599 
3600 	vdev->config->del_vqs(vdev);
3601 
3602 	virtnet_free_queues(vi);
3603 }
3604 
3605 /* How large should a single buffer be so a queue full of these can fit at
3606  * least one full packet?
3607  * Logic below assumes the mergeable buffer header is used.
3608  */
3609 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
3610 {
3611 	const unsigned int hdr_len = vi->hdr_len;
3612 	unsigned int rq_size = virtqueue_get_vring_size(vq);
3613 	unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
3614 	unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
3615 	unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
3616 
3617 	return max(max(min_buf_len, hdr_len) - hdr_len,
3618 		   (unsigned int)GOOD_PACKET_LEN);
3619 }
3620 
3621 static int virtnet_find_vqs(struct virtnet_info *vi)
3622 {
3623 	vq_callback_t **callbacks;
3624 	struct virtqueue **vqs;
3625 	int ret = -ENOMEM;
3626 	int i, total_vqs;
3627 	const char **names;
3628 	bool *ctx;
3629 
3630 	/* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
3631 	 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
3632 	 * possible control vq.
3633 	 */
3634 	total_vqs = vi->max_queue_pairs * 2 +
3635 		    virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
3636 
3637 	/* Allocate space for find_vqs parameters */
3638 	vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
3639 	if (!vqs)
3640 		goto err_vq;
3641 	callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
3642 	if (!callbacks)
3643 		goto err_callback;
3644 	names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
3645 	if (!names)
3646 		goto err_names;
3647 	if (!vi->big_packets || vi->mergeable_rx_bufs) {
3648 		ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
3649 		if (!ctx)
3650 			goto err_ctx;
3651 	} else {
3652 		ctx = NULL;
3653 	}
3654 
3655 	/* Parameters for control virtqueue, if any */
3656 	if (vi->has_cvq) {
3657 		callbacks[total_vqs - 1] = NULL;
3658 		names[total_vqs - 1] = "control";
3659 	}
3660 
3661 	/* Allocate/initialize parameters for send/receive virtqueues */
3662 	for (i = 0; i < vi->max_queue_pairs; i++) {
3663 		callbacks[rxq2vq(i)] = skb_recv_done;
3664 		callbacks[txq2vq(i)] = skb_xmit_done;
3665 		sprintf(vi->rq[i].name, "input.%d", i);
3666 		sprintf(vi->sq[i].name, "output.%d", i);
3667 		names[rxq2vq(i)] = vi->rq[i].name;
3668 		names[txq2vq(i)] = vi->sq[i].name;
3669 		if (ctx)
3670 			ctx[rxq2vq(i)] = true;
3671 	}
3672 
3673 	ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
3674 				  names, ctx, NULL);
3675 	if (ret)
3676 		goto err_find;
3677 
3678 	if (vi->has_cvq) {
3679 		vi->cvq = vqs[total_vqs - 1];
3680 		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
3681 			vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
3682 	}
3683 
3684 	for (i = 0; i < vi->max_queue_pairs; i++) {
3685 		vi->rq[i].vq = vqs[rxq2vq(i)];
3686 		vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
3687 		vi->sq[i].vq = vqs[txq2vq(i)];
3688 	}
3689 
3690 	/* run here: ret == 0. */
3691 
3692 
3693 err_find:
3694 	kfree(ctx);
3695 err_ctx:
3696 	kfree(names);
3697 err_names:
3698 	kfree(callbacks);
3699 err_callback:
3700 	kfree(vqs);
3701 err_vq:
3702 	return ret;
3703 }
3704 
3705 static int virtnet_alloc_queues(struct virtnet_info *vi)
3706 {
3707 	int i;
3708 
3709 	if (vi->has_cvq) {
3710 		vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
3711 		if (!vi->ctrl)
3712 			goto err_ctrl;
3713 	} else {
3714 		vi->ctrl = NULL;
3715 	}
3716 	vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
3717 	if (!vi->sq)
3718 		goto err_sq;
3719 	vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
3720 	if (!vi->rq)
3721 		goto err_rq;
3722 
3723 	INIT_DELAYED_WORK(&vi->refill, refill_work);
3724 	for (i = 0; i < vi->max_queue_pairs; i++) {
3725 		vi->rq[i].pages = NULL;
3726 		netif_napi_add_weight(vi->dev, &vi->rq[i].napi, virtnet_poll,
3727 				      napi_weight);
3728 		netif_napi_add_tx_weight(vi->dev, &vi->sq[i].napi,
3729 					 virtnet_poll_tx,
3730 					 napi_tx ? napi_weight : 0);
3731 
3732 		sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
3733 		ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
3734 		sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
3735 
3736 		u64_stats_init(&vi->rq[i].stats.syncp);
3737 		u64_stats_init(&vi->sq[i].stats.syncp);
3738 	}
3739 
3740 	return 0;
3741 
3742 err_rq:
3743 	kfree(vi->sq);
3744 err_sq:
3745 	kfree(vi->ctrl);
3746 err_ctrl:
3747 	return -ENOMEM;
3748 }
3749 
3750 static int init_vqs(struct virtnet_info *vi)
3751 {
3752 	int ret;
3753 
3754 	/* Allocate send & receive queues */
3755 	ret = virtnet_alloc_queues(vi);
3756 	if (ret)
3757 		goto err;
3758 
3759 	ret = virtnet_find_vqs(vi);
3760 	if (ret)
3761 		goto err_free;
3762 
3763 	cpus_read_lock();
3764 	virtnet_set_affinity(vi);
3765 	cpus_read_unlock();
3766 
3767 	return 0;
3768 
3769 err_free:
3770 	virtnet_free_queues(vi);
3771 err:
3772 	return ret;
3773 }
3774 
3775 #ifdef CONFIG_SYSFS
3776 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
3777 		char *buf)
3778 {
3779 	struct virtnet_info *vi = netdev_priv(queue->dev);
3780 	unsigned int queue_index = get_netdev_rx_queue_index(queue);
3781 	unsigned int headroom = virtnet_get_headroom(vi);
3782 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
3783 	struct ewma_pkt_len *avg;
3784 
3785 	BUG_ON(queue_index >= vi->max_queue_pairs);
3786 	avg = &vi->rq[queue_index].mrg_avg_pkt_len;
3787 	return sprintf(buf, "%u\n",
3788 		       get_mergeable_buf_len(&vi->rq[queue_index], avg,
3789 				       SKB_DATA_ALIGN(headroom + tailroom)));
3790 }
3791 
3792 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
3793 	__ATTR_RO(mergeable_rx_buffer_size);
3794 
3795 static struct attribute *virtio_net_mrg_rx_attrs[] = {
3796 	&mergeable_rx_buffer_size_attribute.attr,
3797 	NULL
3798 };
3799 
3800 static const struct attribute_group virtio_net_mrg_rx_group = {
3801 	.name = "virtio_net",
3802 	.attrs = virtio_net_mrg_rx_attrs
3803 };
3804 #endif
3805 
3806 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
3807 				    unsigned int fbit,
3808 				    const char *fname, const char *dname)
3809 {
3810 	if (!virtio_has_feature(vdev, fbit))
3811 		return false;
3812 
3813 	dev_err(&vdev->dev, "device advertises feature %s but not %s",
3814 		fname, dname);
3815 
3816 	return true;
3817 }
3818 
3819 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)			\
3820 	virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
3821 
3822 static bool virtnet_validate_features(struct virtio_device *vdev)
3823 {
3824 	if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
3825 	    (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
3826 			     "VIRTIO_NET_F_CTRL_VQ") ||
3827 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
3828 			     "VIRTIO_NET_F_CTRL_VQ") ||
3829 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
3830 			     "VIRTIO_NET_F_CTRL_VQ") ||
3831 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
3832 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
3833 			     "VIRTIO_NET_F_CTRL_VQ") ||
3834 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS,
3835 			     "VIRTIO_NET_F_CTRL_VQ") ||
3836 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_HASH_REPORT,
3837 			     "VIRTIO_NET_F_CTRL_VQ") ||
3838 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_NOTF_COAL,
3839 			     "VIRTIO_NET_F_CTRL_VQ"))) {
3840 		return false;
3841 	}
3842 
3843 	return true;
3844 }
3845 
3846 #define MIN_MTU ETH_MIN_MTU
3847 #define MAX_MTU ETH_MAX_MTU
3848 
3849 static int virtnet_validate(struct virtio_device *vdev)
3850 {
3851 	if (!vdev->config->get) {
3852 		dev_err(&vdev->dev, "%s failure: config access disabled\n",
3853 			__func__);
3854 		return -EINVAL;
3855 	}
3856 
3857 	if (!virtnet_validate_features(vdev))
3858 		return -EINVAL;
3859 
3860 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3861 		int mtu = virtio_cread16(vdev,
3862 					 offsetof(struct virtio_net_config,
3863 						  mtu));
3864 		if (mtu < MIN_MTU)
3865 			__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
3866 	}
3867 
3868 	if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY) &&
3869 	    !virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
3870 		dev_warn(&vdev->dev, "device advertises feature VIRTIO_NET_F_STANDBY but not VIRTIO_NET_F_MAC, disabling standby");
3871 		__virtio_clear_bit(vdev, VIRTIO_NET_F_STANDBY);
3872 	}
3873 
3874 	return 0;
3875 }
3876 
3877 static bool virtnet_check_guest_gso(const struct virtnet_info *vi)
3878 {
3879 	return virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3880 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3881 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
3882 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
3883 		(virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) &&
3884 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6));
3885 }
3886 
3887 static void virtnet_set_big_packets(struct virtnet_info *vi, const int mtu)
3888 {
3889 	bool guest_gso = virtnet_check_guest_gso(vi);
3890 
3891 	/* If device can receive ANY guest GSO packets, regardless of mtu,
3892 	 * allocate packets of maximum size, otherwise limit it to only
3893 	 * mtu size worth only.
3894 	 */
3895 	if (mtu > ETH_DATA_LEN || guest_gso) {
3896 		vi->big_packets = true;
3897 		vi->big_packets_num_skbfrags = guest_gso ? MAX_SKB_FRAGS : DIV_ROUND_UP(mtu, PAGE_SIZE);
3898 	}
3899 }
3900 
3901 static int virtnet_probe(struct virtio_device *vdev)
3902 {
3903 	int i, err = -ENOMEM;
3904 	struct net_device *dev;
3905 	struct virtnet_info *vi;
3906 	u16 max_queue_pairs;
3907 	int mtu = 0;
3908 
3909 	/* Find if host supports multiqueue/rss virtio_net device */
3910 	max_queue_pairs = 1;
3911 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MQ) || virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
3912 		max_queue_pairs =
3913 		     virtio_cread16(vdev, offsetof(struct virtio_net_config, max_virtqueue_pairs));
3914 
3915 	/* We need at least 2 queue's */
3916 	if (max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
3917 	    max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
3918 	    !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3919 		max_queue_pairs = 1;
3920 
3921 	/* Allocate ourselves a network device with room for our info */
3922 	dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
3923 	if (!dev)
3924 		return -ENOMEM;
3925 
3926 	/* Set up network device as normal. */
3927 	dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE |
3928 			   IFF_TX_SKB_NO_LINEAR;
3929 	dev->netdev_ops = &virtnet_netdev;
3930 	dev->features = NETIF_F_HIGHDMA;
3931 
3932 	dev->ethtool_ops = &virtnet_ethtool_ops;
3933 	SET_NETDEV_DEV(dev, &vdev->dev);
3934 
3935 	/* Do we support "hardware" checksums? */
3936 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
3937 		/* This opens up the world of extra features. */
3938 		dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3939 		if (csum)
3940 			dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3941 
3942 		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
3943 			dev->hw_features |= NETIF_F_TSO
3944 				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
3945 		}
3946 		/* Individual feature bits: what can host handle? */
3947 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
3948 			dev->hw_features |= NETIF_F_TSO;
3949 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3950 			dev->hw_features |= NETIF_F_TSO6;
3951 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3952 			dev->hw_features |= NETIF_F_TSO_ECN;
3953 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_USO))
3954 			dev->hw_features |= NETIF_F_GSO_UDP_L4;
3955 
3956 		dev->features |= NETIF_F_GSO_ROBUST;
3957 
3958 		if (gso)
3959 			dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3960 		/* (!csum && gso) case will be fixed by register_netdev() */
3961 	}
3962 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3963 		dev->features |= NETIF_F_RXCSUM;
3964 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3965 	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3966 		dev->features |= NETIF_F_GRO_HW;
3967 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3968 		dev->hw_features |= NETIF_F_GRO_HW;
3969 
3970 	dev->vlan_features = dev->features;
3971 	dev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT;
3972 
3973 	/* MTU range: 68 - 65535 */
3974 	dev->min_mtu = MIN_MTU;
3975 	dev->max_mtu = MAX_MTU;
3976 
3977 	/* Configuration may specify what MAC to use.  Otherwise random. */
3978 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
3979 		u8 addr[ETH_ALEN];
3980 
3981 		virtio_cread_bytes(vdev,
3982 				   offsetof(struct virtio_net_config, mac),
3983 				   addr, ETH_ALEN);
3984 		eth_hw_addr_set(dev, addr);
3985 	} else {
3986 		eth_hw_addr_random(dev);
3987 		dev_info(&vdev->dev, "Assigned random MAC address %pM\n",
3988 			 dev->dev_addr);
3989 	}
3990 
3991 	/* Set up our device-specific information */
3992 	vi = netdev_priv(dev);
3993 	vi->dev = dev;
3994 	vi->vdev = vdev;
3995 	vdev->priv = vi;
3996 
3997 	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3998 	spin_lock_init(&vi->refill_lock);
3999 
4000 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) {
4001 		vi->mergeable_rx_bufs = true;
4002 		dev->xdp_features |= NETDEV_XDP_ACT_RX_SG;
4003 	}
4004 
4005 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) {
4006 		vi->rx_usecs = 0;
4007 		vi->tx_usecs = 0;
4008 		vi->tx_max_packets = 0;
4009 		vi->rx_max_packets = 0;
4010 	}
4011 
4012 	if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
4013 		vi->has_rss_hash_report = true;
4014 
4015 	if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
4016 		vi->has_rss = true;
4017 
4018 	if (vi->has_rss || vi->has_rss_hash_report) {
4019 		vi->rss_indir_table_size =
4020 			virtio_cread16(vdev, offsetof(struct virtio_net_config,
4021 				rss_max_indirection_table_length));
4022 		vi->rss_key_size =
4023 			virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
4024 
4025 		vi->rss_hash_types_supported =
4026 		    virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
4027 		vi->rss_hash_types_supported &=
4028 				~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
4029 				  VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
4030 				  VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);
4031 
4032 		dev->hw_features |= NETIF_F_RXHASH;
4033 	}
4034 
4035 	if (vi->has_rss_hash_report)
4036 		vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash);
4037 	else if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
4038 		 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
4039 		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
4040 	else
4041 		vi->hdr_len = sizeof(struct virtio_net_hdr);
4042 
4043 	if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
4044 	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
4045 		vi->any_header_sg = true;
4046 
4047 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
4048 		vi->has_cvq = true;
4049 
4050 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
4051 		mtu = virtio_cread16(vdev,
4052 				     offsetof(struct virtio_net_config,
4053 					      mtu));
4054 		if (mtu < dev->min_mtu) {
4055 			/* Should never trigger: MTU was previously validated
4056 			 * in virtnet_validate.
4057 			 */
4058 			dev_err(&vdev->dev,
4059 				"device MTU appears to have changed it is now %d < %d",
4060 				mtu, dev->min_mtu);
4061 			err = -EINVAL;
4062 			goto free;
4063 		}
4064 
4065 		dev->mtu = mtu;
4066 		dev->max_mtu = mtu;
4067 	}
4068 
4069 	virtnet_set_big_packets(vi, mtu);
4070 
4071 	if (vi->any_header_sg)
4072 		dev->needed_headroom = vi->hdr_len;
4073 
4074 	/* Enable multiqueue by default */
4075 	if (num_online_cpus() >= max_queue_pairs)
4076 		vi->curr_queue_pairs = max_queue_pairs;
4077 	else
4078 		vi->curr_queue_pairs = num_online_cpus();
4079 	vi->max_queue_pairs = max_queue_pairs;
4080 
4081 	/* Allocate/initialize the rx/tx queues, and invoke find_vqs */
4082 	err = init_vqs(vi);
4083 	if (err)
4084 		goto free;
4085 
4086 #ifdef CONFIG_SYSFS
4087 	if (vi->mergeable_rx_bufs)
4088 		dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
4089 #endif
4090 	netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
4091 	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
4092 
4093 	virtnet_init_settings(dev);
4094 
4095 	if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
4096 		vi->failover = net_failover_create(vi->dev);
4097 		if (IS_ERR(vi->failover)) {
4098 			err = PTR_ERR(vi->failover);
4099 			goto free_vqs;
4100 		}
4101 	}
4102 
4103 	if (vi->has_rss || vi->has_rss_hash_report)
4104 		virtnet_init_default_rss(vi);
4105 
4106 	/* serialize netdev register + virtio_device_ready() with ndo_open() */
4107 	rtnl_lock();
4108 
4109 	err = register_netdevice(dev);
4110 	if (err) {
4111 		pr_debug("virtio_net: registering device failed\n");
4112 		rtnl_unlock();
4113 		goto free_failover;
4114 	}
4115 
4116 	virtio_device_ready(vdev);
4117 
4118 	/* a random MAC address has been assigned, notify the device.
4119 	 * We don't fail probe if VIRTIO_NET_F_CTRL_MAC_ADDR is not there
4120 	 * because many devices work fine without getting MAC explicitly
4121 	 */
4122 	if (!virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
4123 	    virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
4124 		struct scatterlist sg;
4125 
4126 		sg_init_one(&sg, dev->dev_addr, dev->addr_len);
4127 		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
4128 					  VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
4129 			pr_debug("virtio_net: setting MAC address failed\n");
4130 			rtnl_unlock();
4131 			err = -EINVAL;
4132 			goto free_unregister_netdev;
4133 		}
4134 	}
4135 
4136 	rtnl_unlock();
4137 
4138 	err = virtnet_cpu_notif_add(vi);
4139 	if (err) {
4140 		pr_debug("virtio_net: registering cpu notifier failed\n");
4141 		goto free_unregister_netdev;
4142 	}
4143 
4144 	virtnet_set_queues(vi, vi->curr_queue_pairs);
4145 
4146 	/* Assume link up if device can't report link status,
4147 	   otherwise get link status from config. */
4148 	netif_carrier_off(dev);
4149 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
4150 		schedule_work(&vi->config_work);
4151 	} else {
4152 		vi->status = VIRTIO_NET_S_LINK_UP;
4153 		virtnet_update_settings(vi);
4154 		netif_carrier_on(dev);
4155 	}
4156 
4157 	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
4158 		if (virtio_has_feature(vi->vdev, guest_offloads[i]))
4159 			set_bit(guest_offloads[i], &vi->guest_offloads);
4160 	vi->guest_offloads_capable = vi->guest_offloads;
4161 
4162 	pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
4163 		 dev->name, max_queue_pairs);
4164 
4165 	return 0;
4166 
4167 free_unregister_netdev:
4168 	unregister_netdev(dev);
4169 free_failover:
4170 	net_failover_destroy(vi->failover);
4171 free_vqs:
4172 	virtio_reset_device(vdev);
4173 	cancel_delayed_work_sync(&vi->refill);
4174 	free_receive_page_frags(vi);
4175 	virtnet_del_vqs(vi);
4176 free:
4177 	free_netdev(dev);
4178 	return err;
4179 }
4180 
4181 static void remove_vq_common(struct virtnet_info *vi)
4182 {
4183 	virtio_reset_device(vi->vdev);
4184 
4185 	/* Free unused buffers in both send and recv, if any. */
4186 	free_unused_bufs(vi);
4187 
4188 	free_receive_bufs(vi);
4189 
4190 	free_receive_page_frags(vi);
4191 
4192 	virtnet_del_vqs(vi);
4193 }
4194 
4195 static void virtnet_remove(struct virtio_device *vdev)
4196 {
4197 	struct virtnet_info *vi = vdev->priv;
4198 
4199 	virtnet_cpu_notif_remove(vi);
4200 
4201 	/* Make sure no work handler is accessing the device. */
4202 	flush_work(&vi->config_work);
4203 
4204 	unregister_netdev(vi->dev);
4205 
4206 	net_failover_destroy(vi->failover);
4207 
4208 	remove_vq_common(vi);
4209 
4210 	free_netdev(vi->dev);
4211 }
4212 
4213 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
4214 {
4215 	struct virtnet_info *vi = vdev->priv;
4216 
4217 	virtnet_cpu_notif_remove(vi);
4218 	virtnet_freeze_down(vdev);
4219 	remove_vq_common(vi);
4220 
4221 	return 0;
4222 }
4223 
4224 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
4225 {
4226 	struct virtnet_info *vi = vdev->priv;
4227 	int err;
4228 
4229 	err = virtnet_restore_up(vdev);
4230 	if (err)
4231 		return err;
4232 	virtnet_set_queues(vi, vi->curr_queue_pairs);
4233 
4234 	err = virtnet_cpu_notif_add(vi);
4235 	if (err) {
4236 		virtnet_freeze_down(vdev);
4237 		remove_vq_common(vi);
4238 		return err;
4239 	}
4240 
4241 	return 0;
4242 }
4243 
4244 static struct virtio_device_id id_table[] = {
4245 	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
4246 	{ 0 },
4247 };
4248 
4249 #define VIRTNET_FEATURES \
4250 	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
4251 	VIRTIO_NET_F_MAC, \
4252 	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
4253 	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
4254 	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
4255 	VIRTIO_NET_F_HOST_USO, VIRTIO_NET_F_GUEST_USO4, VIRTIO_NET_F_GUEST_USO6, \
4256 	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
4257 	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
4258 	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
4259 	VIRTIO_NET_F_CTRL_MAC_ADDR, \
4260 	VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
4261 	VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \
4262 	VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_NOTF_COAL, \
4263 	VIRTIO_NET_F_GUEST_HDRLEN
4264 
4265 static unsigned int features[] = {
4266 	VIRTNET_FEATURES,
4267 };
4268 
4269 static unsigned int features_legacy[] = {
4270 	VIRTNET_FEATURES,
4271 	VIRTIO_NET_F_GSO,
4272 	VIRTIO_F_ANY_LAYOUT,
4273 };
4274 
4275 static struct virtio_driver virtio_net_driver = {
4276 	.feature_table = features,
4277 	.feature_table_size = ARRAY_SIZE(features),
4278 	.feature_table_legacy = features_legacy,
4279 	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
4280 	.driver.name =	KBUILD_MODNAME,
4281 	.driver.owner =	THIS_MODULE,
4282 	.id_table =	id_table,
4283 	.validate =	virtnet_validate,
4284 	.probe =	virtnet_probe,
4285 	.remove =	virtnet_remove,
4286 	.config_changed = virtnet_config_changed,
4287 #ifdef CONFIG_PM_SLEEP
4288 	.freeze =	virtnet_freeze,
4289 	.restore =	virtnet_restore,
4290 #endif
4291 };
4292 
4293 static __init int virtio_net_driver_init(void)
4294 {
4295 	int ret;
4296 
4297 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
4298 				      virtnet_cpu_online,
4299 				      virtnet_cpu_down_prep);
4300 	if (ret < 0)
4301 		goto out;
4302 	virtionet_online = ret;
4303 	ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
4304 				      NULL, virtnet_cpu_dead);
4305 	if (ret)
4306 		goto err_dead;
4307 	ret = register_virtio_driver(&virtio_net_driver);
4308 	if (ret)
4309 		goto err_virtio;
4310 	return 0;
4311 err_virtio:
4312 	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4313 err_dead:
4314 	cpuhp_remove_multi_state(virtionet_online);
4315 out:
4316 	return ret;
4317 }
4318 module_init(virtio_net_driver_init);
4319 
4320 static __exit void virtio_net_driver_exit(void)
4321 {
4322 	unregister_virtio_driver(&virtio_net_driver);
4323 	cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
4324 	cpuhp_remove_multi_state(virtionet_online);
4325 }
4326 module_exit(virtio_net_driver_exit);
4327 
4328 MODULE_DEVICE_TABLE(virtio, id_table);
4329 MODULE_DESCRIPTION("Virtio network driver");
4330 MODULE_LICENSE("GPL");
4331