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1/* A network driver using virtio.
2 *
3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19//#define DEBUG
20#include <linux/netdevice.h>
21#include <linux/etherdevice.h>
22#include <linux/ethtool.h>
23#include <linux/module.h>
24#include <linux/virtio.h>
25#include <linux/virtio_net.h>
26#include <linux/scatterlist.h>
27#include <linux/if_vlan.h>
28#include <linux/slab.h>
29
30static int napi_weight = 128;
31module_param(napi_weight, int, 0444);
32
33static int csum = 1, gso = 1;
34module_param(csum, bool, 0444);
35module_param(gso, bool, 0444);
36
37/* FIXME: MTU in config. */
38#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
39#define GOOD_COPY_LEN 128
40
41#define VIRTNET_SEND_COMMAND_SG_MAX 2
42
43struct virtnet_stats {
44 struct u64_stats_sync syncp;
45 u64 tx_bytes;
46 u64 tx_packets;
47
48 u64 rx_bytes;
49 u64 rx_packets;
50};
51
52struct virtnet_info {
53 struct virtio_device *vdev;
54 struct virtqueue *rvq, *svq, *cvq;
55 struct net_device *dev;
56 struct napi_struct napi;
57 unsigned int status;
58
59 /* Number of input buffers, and max we've ever had. */
60 unsigned int num, max;
61
62 /* I like... big packets and I cannot lie! */
63 bool big_packets;
64
65 /* Host will merge rx buffers for big packets (shake it! shake it!) */
66 bool mergeable_rx_bufs;
67
68 /* Active statistics */
69 struct virtnet_stats __percpu *stats;
70
71 /* Work struct for refilling if we run low on memory. */
72 struct delayed_work refill;
73
74 /* Chain pages by the private ptr. */
75 struct page *pages;
76
77 /* fragments + linear part + virtio header */
78 struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
79 struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
80};
81
82struct skb_vnet_hdr {
83 union {
84 struct virtio_net_hdr hdr;
85 struct virtio_net_hdr_mrg_rxbuf mhdr;
86 };
87 unsigned int num_sg;
88};
89
90struct padded_vnet_hdr {
91 struct virtio_net_hdr hdr;
92 /*
93 * virtio_net_hdr should be in a separated sg buffer because of a
94 * QEMU bug, and data sg buffer shares same page with this header sg.
95 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
96 */
97 char padding[6];
98};
99
100static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
101{
102 return (struct skb_vnet_hdr *)skb->cb;
103}
104
105/*
106 * private is used to chain pages for big packets, put the whole
107 * most recent used list in the beginning for reuse
108 */
109static void give_pages(struct virtnet_info *vi, struct page *page)
110{
111 struct page *end;
112
113 /* Find end of list, sew whole thing into vi->pages. */
114 for (end = page; end->private; end = (struct page *)end->private);
115 end->private = (unsigned long)vi->pages;
116 vi->pages = page;
117}
118
119static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
120{
121 struct page *p = vi->pages;
122
123 if (p) {
124 vi->pages = (struct page *)p->private;
125 /* clear private here, it is used to chain pages */
126 p->private = 0;
127 } else
128 p = alloc_page(gfp_mask);
129 return p;
130}
131
132static void skb_xmit_done(struct virtqueue *svq)
133{
134 struct virtnet_info *vi = svq->vdev->priv;
135
136 /* Suppress further interrupts. */
137 virtqueue_disable_cb(svq);
138
139 /* We were probably waiting for more output buffers. */
140 netif_wake_queue(vi->dev);
141}
142
143static void set_skb_frag(struct sk_buff *skb, struct page *page,
144 unsigned int offset, unsigned int *len)
145{
146 int i = skb_shinfo(skb)->nr_frags;
147 skb_frag_t *f;
148
149 f = &skb_shinfo(skb)->frags[i];
150 f->size = min((unsigned)PAGE_SIZE - offset, *len);
151 f->page_offset = offset;
152 f->page = page;
153
154 skb->data_len += f->size;
155 skb->len += f->size;
156 skb_shinfo(skb)->nr_frags++;
157 *len -= f->size;
158}
159
160static struct sk_buff *page_to_skb(struct virtnet_info *vi,
161 struct page *page, unsigned int len)
162{
163 struct sk_buff *skb;
164 struct skb_vnet_hdr *hdr;
165 unsigned int copy, hdr_len, offset;
166 char *p;
167
168 p = page_address(page);
169
170 /* copy small packet so we can reuse these pages for small data */
171 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
172 if (unlikely(!skb))
173 return NULL;
174
175 hdr = skb_vnet_hdr(skb);
176
177 if (vi->mergeable_rx_bufs) {
178 hdr_len = sizeof hdr->mhdr;
179 offset = hdr_len;
180 } else {
181 hdr_len = sizeof hdr->hdr;
182 offset = sizeof(struct padded_vnet_hdr);
183 }
184
185 memcpy(hdr, p, hdr_len);
186
187 len -= hdr_len;
188 p += offset;
189
190 copy = len;
191 if (copy > skb_tailroom(skb))
192 copy = skb_tailroom(skb);
193 memcpy(skb_put(skb, copy), p, copy);
194
195 len -= copy;
196 offset += copy;
197
198 while (len) {
199 set_skb_frag(skb, page, offset, &len);
200 page = (struct page *)page->private;
201 offset = 0;
202 }
203
204 if (page)
205 give_pages(vi, page);
206
207 return skb;
208}
209
210static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
211{
212 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
213 struct page *page;
214 int num_buf, i, len;
215
216 num_buf = hdr->mhdr.num_buffers;
217 while (--num_buf) {
218 i = skb_shinfo(skb)->nr_frags;
219 if (i >= MAX_SKB_FRAGS) {
220 pr_debug("%s: packet too long\n", skb->dev->name);
221 skb->dev->stats.rx_length_errors++;
222 return -EINVAL;
223 }
224 page = virtqueue_get_buf(vi->rvq, &len);
225 if (!page) {
226 pr_debug("%s: rx error: %d buffers missing\n",
227 skb->dev->name, hdr->mhdr.num_buffers);
228 skb->dev->stats.rx_length_errors++;
229 return -EINVAL;
230 }
231
232 if (len > PAGE_SIZE)
233 len = PAGE_SIZE;
234
235 set_skb_frag(skb, page, 0, &len);
236
237 --vi->num;
238 }
239 return 0;
240}
241
242static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
243{
244 struct virtnet_info *vi = netdev_priv(dev);
245 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
246 struct sk_buff *skb;
247 struct page *page;
248 struct skb_vnet_hdr *hdr;
249
250 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
251 pr_debug("%s: short packet %i\n", dev->name, len);
252 dev->stats.rx_length_errors++;
253 if (vi->mergeable_rx_bufs || vi->big_packets)
254 give_pages(vi, buf);
255 else
256 dev_kfree_skb(buf);
257 return;
258 }
259
260 if (!vi->mergeable_rx_bufs && !vi->big_packets) {
261 skb = buf;
262 len -= sizeof(struct virtio_net_hdr);
263 skb_trim(skb, len);
264 } else {
265 page = buf;
266 skb = page_to_skb(vi, page, len);
267 if (unlikely(!skb)) {
268 dev->stats.rx_dropped++;
269 give_pages(vi, page);
270 return;
271 }
272 if (vi->mergeable_rx_bufs)
273 if (receive_mergeable(vi, skb)) {
274 dev_kfree_skb(skb);
275 return;
276 }
277 }
278
279 hdr = skb_vnet_hdr(skb);
280 skb->truesize += skb->data_len;
281
282 u64_stats_update_begin(&stats->syncp);
283 stats->rx_bytes += skb->len;
284 stats->rx_packets++;
285 u64_stats_update_end(&stats->syncp);
286
287 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
288 pr_debug("Needs csum!\n");
289 if (!skb_partial_csum_set(skb,
290 hdr->hdr.csum_start,
291 hdr->hdr.csum_offset))
292 goto frame_err;
293 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
294 skb->ip_summed = CHECKSUM_UNNECESSARY;
295 }
296
297 skb->protocol = eth_type_trans(skb, dev);
298 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
299 ntohs(skb->protocol), skb->len, skb->pkt_type);
300
301 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
302 pr_debug("GSO!\n");
303 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
304 case VIRTIO_NET_HDR_GSO_TCPV4:
305 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
306 break;
307 case VIRTIO_NET_HDR_GSO_UDP:
308 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
309 break;
310 case VIRTIO_NET_HDR_GSO_TCPV6:
311 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
312 break;
313 default:
314 if (net_ratelimit())
315 printk(KERN_WARNING "%s: bad gso type %u.\n",
316 dev->name, hdr->hdr.gso_type);
317 goto frame_err;
318 }
319
320 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
321 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
322
323 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
324 if (skb_shinfo(skb)->gso_size == 0) {
325 if (net_ratelimit())
326 printk(KERN_WARNING "%s: zero gso size.\n",
327 dev->name);
328 goto frame_err;
329 }
330
331 /* Header must be checked, and gso_segs computed. */
332 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
333 skb_shinfo(skb)->gso_segs = 0;
334 }
335
336 netif_receive_skb(skb);
337 return;
338
339frame_err:
340 dev->stats.rx_frame_errors++;
341 dev_kfree_skb(skb);
342}
343
344static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
345{
346 struct sk_buff *skb;
347 struct skb_vnet_hdr *hdr;
348 int err;
349
350 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
351 if (unlikely(!skb))
352 return -ENOMEM;
353
354 skb_put(skb, MAX_PACKET_LEN);
355
356 hdr = skb_vnet_hdr(skb);
357 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr);
358
359 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
360
361 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp);
362 if (err < 0)
363 dev_kfree_skb(skb);
364
365 return err;
366}
367
368static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
369{
370 struct page *first, *list = NULL;
371 char *p;
372 int i, err, offset;
373
374 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
375 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
376 first = get_a_page(vi, gfp);
377 if (!first) {
378 if (list)
379 give_pages(vi, list);
380 return -ENOMEM;
381 }
382 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE);
383
384 /* chain new page in list head to match sg */
385 first->private = (unsigned long)list;
386 list = first;
387 }
388
389 first = get_a_page(vi, gfp);
390 if (!first) {
391 give_pages(vi, list);
392 return -ENOMEM;
393 }
394 p = page_address(first);
395
396 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */
397 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
398 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr));
399
400 /* vi->rx_sg[1] for data packet, from offset */
401 offset = sizeof(struct padded_vnet_hdr);
402 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset);
403
404 /* chain first in list head */
405 first->private = (unsigned long)list;
406 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
407 first, gfp);
408 if (err < 0)
409 give_pages(vi, first);
410
411 return err;
412}
413
414static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
415{
416 struct page *page;
417 int err;
418
419 page = get_a_page(vi, gfp);
420 if (!page)
421 return -ENOMEM;
422
423 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE);
424
425 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp);
426 if (err < 0)
427 give_pages(vi, page);
428
429 return err;
430}
431
432/* Returns false if we couldn't fill entirely (OOM). */
433static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
434{
435 int err;
436 bool oom;
437
438 do {
439 if (vi->mergeable_rx_bufs)
440 err = add_recvbuf_mergeable(vi, gfp);
441 else if (vi->big_packets)
442 err = add_recvbuf_big(vi, gfp);
443 else
444 err = add_recvbuf_small(vi, gfp);
445
446 oom = err == -ENOMEM;
447 if (err < 0)
448 break;
449 ++vi->num;
450 } while (err > 0);
451 if (unlikely(vi->num > vi->max))
452 vi->max = vi->num;
453 virtqueue_kick(vi->rvq);
454 return !oom;
455}
456
457static void skb_recv_done(struct virtqueue *rvq)
458{
459 struct virtnet_info *vi = rvq->vdev->priv;
460 /* Schedule NAPI, Suppress further interrupts if successful. */
461 if (napi_schedule_prep(&vi->napi)) {
462 virtqueue_disable_cb(rvq);
463 __napi_schedule(&vi->napi);
464 }
465}
466
467static void virtnet_napi_enable(struct virtnet_info *vi)
468{
469 napi_enable(&vi->napi);
470
471 /* If all buffers were filled by other side before we napi_enabled, we
472 * won't get another interrupt, so process any outstanding packets
473 * now. virtnet_poll wants re-enable the queue, so we disable here.
474 * We synchronize against interrupts via NAPI_STATE_SCHED */
475 if (napi_schedule_prep(&vi->napi)) {
476 virtqueue_disable_cb(vi->rvq);
477 __napi_schedule(&vi->napi);
478 }
479}
480
481static void refill_work(struct work_struct *work)
482{
483 struct virtnet_info *vi;
484 bool still_empty;
485
486 vi = container_of(work, struct virtnet_info, refill.work);
487 napi_disable(&vi->napi);
488 still_empty = !try_fill_recv(vi, GFP_KERNEL);
489 virtnet_napi_enable(vi);
490
491 /* In theory, this can happen: if we don't get any buffers in
492 * we will *never* try to fill again. */
493 if (still_empty)
494 schedule_delayed_work(&vi->refill, HZ/2);
495}
496
497static int virtnet_poll(struct napi_struct *napi, int budget)
498{
499 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
500 void *buf;
501 unsigned int len, received = 0;
502
503again:
504 while (received < budget &&
505 (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) {
506 receive_buf(vi->dev, buf, len);
507 --vi->num;
508 received++;
509 }
510
511 if (vi->num < vi->max / 2) {
512 if (!try_fill_recv(vi, GFP_ATOMIC))
513 schedule_delayed_work(&vi->refill, 0);
514 }
515
516 /* Out of packets? */
517 if (received < budget) {
518 napi_complete(napi);
519 if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
520 napi_schedule_prep(napi)) {
521 virtqueue_disable_cb(vi->rvq);
522 __napi_schedule(napi);
523 goto again;
524 }
525 }
526
527 return received;
528}
529
530static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
531{
532 struct sk_buff *skb;
533 unsigned int len, tot_sgs = 0;
534 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats);
535
536 while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
537 pr_debug("Sent skb %p\n", skb);
538
539 u64_stats_update_begin(&stats->syncp);
540 stats->tx_bytes += skb->len;
541 stats->tx_packets++;
542 u64_stats_update_end(&stats->syncp);
543
544 tot_sgs += skb_vnet_hdr(skb)->num_sg;
545 dev_kfree_skb_any(skb);
546 }
547 return tot_sgs;
548}
549
550static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
551{
552 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
553 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
554
555 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
556
557 if (skb->ip_summed == CHECKSUM_PARTIAL) {
558 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
559 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
560 hdr->hdr.csum_offset = skb->csum_offset;
561 } else {
562 hdr->hdr.flags = 0;
563 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
564 }
565
566 if (skb_is_gso(skb)) {
567 hdr->hdr.hdr_len = skb_headlen(skb);
568 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
569 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
570 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
571 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
572 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
573 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
574 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
575 else
576 BUG();
577 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
578 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
579 } else {
580 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
581 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
582 }
583
584 hdr->mhdr.num_buffers = 0;
585
586 /* Encode metadata header at front. */
587 if (vi->mergeable_rx_bufs)
588 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
589 else
590 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
591
592 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
593 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg,
594 0, skb);
595}
596
597static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
598{
599 struct virtnet_info *vi = netdev_priv(dev);
600 int capacity;
601
602 /* Free up any pending old buffers before queueing new ones. */
603 free_old_xmit_skbs(vi);
604
605 /* Try to transmit */
606 capacity = xmit_skb(vi, skb);
607
608 /* This can happen with OOM and indirect buffers. */
609 if (unlikely(capacity < 0)) {
610 if (net_ratelimit()) {
611 if (likely(capacity == -ENOMEM)) {
612 dev_warn(&dev->dev,
613 "TX queue failure: out of memory\n");
614 } else {
615 dev->stats.tx_fifo_errors++;
616 dev_warn(&dev->dev,
617 "Unexpected TX queue failure: %d\n",
618 capacity);
619 }
620 }
621 dev->stats.tx_dropped++;
622 kfree_skb(skb);
623 return NETDEV_TX_OK;
624 }
625 virtqueue_kick(vi->svq);
626
627 /* Don't wait up for transmitted skbs to be freed. */
628 skb_orphan(skb);
629 nf_reset(skb);
630
631 /* Apparently nice girls don't return TX_BUSY; stop the queue
632 * before it gets out of hand. Naturally, this wastes entries. */
633 if (capacity < 2+MAX_SKB_FRAGS) {
634 netif_stop_queue(dev);
635 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
636 /* More just got used, free them then recheck. */
637 capacity += free_old_xmit_skbs(vi);
638 if (capacity >= 2+MAX_SKB_FRAGS) {
639 netif_start_queue(dev);
640 virtqueue_disable_cb(vi->svq);
641 }
642 }
643 }
644
645 return NETDEV_TX_OK;
646}
647
648static int virtnet_set_mac_address(struct net_device *dev, void *p)
649{
650 struct virtnet_info *vi = netdev_priv(dev);
651 struct virtio_device *vdev = vi->vdev;
652 int ret;
653
654 ret = eth_mac_addr(dev, p);
655 if (ret)
656 return ret;
657
658 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
659 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
660 dev->dev_addr, dev->addr_len);
661
662 return 0;
663}
664
665static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
666 struct rtnl_link_stats64 *tot)
667{
668 struct virtnet_info *vi = netdev_priv(dev);
669 int cpu;
670 unsigned int start;
671
672 for_each_possible_cpu(cpu) {
673 struct virtnet_stats __percpu *stats
674 = per_cpu_ptr(vi->stats, cpu);
675 u64 tpackets, tbytes, rpackets, rbytes;
676
677 do {
678 start = u64_stats_fetch_begin(&stats->syncp);
679 tpackets = stats->tx_packets;
680 tbytes = stats->tx_bytes;
681 rpackets = stats->rx_packets;
682 rbytes = stats->rx_bytes;
683 } while (u64_stats_fetch_retry(&stats->syncp, start));
684
685 tot->rx_packets += rpackets;
686 tot->tx_packets += tpackets;
687 tot->rx_bytes += rbytes;
688 tot->tx_bytes += tbytes;
689 }
690
691 tot->tx_dropped = dev->stats.tx_dropped;
692 tot->rx_dropped = dev->stats.rx_dropped;
693 tot->rx_length_errors = dev->stats.rx_length_errors;
694 tot->rx_frame_errors = dev->stats.rx_frame_errors;
695
696 return tot;
697}
698
699#ifdef CONFIG_NET_POLL_CONTROLLER
700static void virtnet_netpoll(struct net_device *dev)
701{
702 struct virtnet_info *vi = netdev_priv(dev);
703
704 napi_schedule(&vi->napi);
705}
706#endif
707
708static int virtnet_open(struct net_device *dev)
709{
710 struct virtnet_info *vi = netdev_priv(dev);
711
712 virtnet_napi_enable(vi);
713 return 0;
714}
715
716/*
717 * Send command via the control virtqueue and check status. Commands
718 * supported by the hypervisor, as indicated by feature bits, should
719 * never fail unless improperly formated.
720 */
721static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
722 struct scatterlist *data, int out, int in)
723{
724 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
725 struct virtio_net_ctrl_hdr ctrl;
726 virtio_net_ctrl_ack status = ~0;
727 unsigned int tmp;
728 int i;
729
730 /* Caller should know better */
731 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
732 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
733
734 out++; /* Add header */
735 in++; /* Add return status */
736
737 ctrl.class = class;
738 ctrl.cmd = cmd;
739
740 sg_init_table(sg, out + in);
741
742 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
743 for_each_sg(data, s, out + in - 2, i)
744 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
745 sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
746
747 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0);
748
749 virtqueue_kick(vi->cvq);
750
751 /*
752 * Spin for a response, the kick causes an ioport write, trapping
753 * into the hypervisor, so the request should be handled immediately.
754 */
755 while (!virtqueue_get_buf(vi->cvq, &tmp))
756 cpu_relax();
757
758 return status == VIRTIO_NET_OK;
759}
760
761static int virtnet_close(struct net_device *dev)
762{
763 struct virtnet_info *vi = netdev_priv(dev);
764
765 napi_disable(&vi->napi);
766
767 return 0;
768}
769
770static void virtnet_set_rx_mode(struct net_device *dev)
771{
772 struct virtnet_info *vi = netdev_priv(dev);
773 struct scatterlist sg[2];
774 u8 promisc, allmulti;
775 struct virtio_net_ctrl_mac *mac_data;
776 struct netdev_hw_addr *ha;
777 int uc_count;
778 int mc_count;
779 void *buf;
780 int i;
781
782 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
783 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
784 return;
785
786 promisc = ((dev->flags & IFF_PROMISC) != 0);
787 allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
788
789 sg_init_one(sg, &promisc, sizeof(promisc));
790
791 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
792 VIRTIO_NET_CTRL_RX_PROMISC,
793 sg, 1, 0))
794 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
795 promisc ? "en" : "dis");
796
797 sg_init_one(sg, &allmulti, sizeof(allmulti));
798
799 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
800 VIRTIO_NET_CTRL_RX_ALLMULTI,
801 sg, 1, 0))
802 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
803 allmulti ? "en" : "dis");
804
805 uc_count = netdev_uc_count(dev);
806 mc_count = netdev_mc_count(dev);
807 /* MAC filter - use one buffer for both lists */
808 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
809 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
810 mac_data = buf;
811 if (!buf) {
812 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
813 return;
814 }
815
816 sg_init_table(sg, 2);
817
818 /* Store the unicast list and count in the front of the buffer */
819 mac_data->entries = uc_count;
820 i = 0;
821 netdev_for_each_uc_addr(ha, dev)
822 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
823
824 sg_set_buf(&sg[0], mac_data,
825 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
826
827 /* multicast list and count fill the end */
828 mac_data = (void *)&mac_data->macs[uc_count][0];
829
830 mac_data->entries = mc_count;
831 i = 0;
832 netdev_for_each_mc_addr(ha, dev)
833 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
834
835 sg_set_buf(&sg[1], mac_data,
836 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
837
838 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
839 VIRTIO_NET_CTRL_MAC_TABLE_SET,
840 sg, 2, 0))
841 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
842
843 kfree(buf);
844}
845
846static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
847{
848 struct virtnet_info *vi = netdev_priv(dev);
849 struct scatterlist sg;
850
851 sg_init_one(&sg, &vid, sizeof(vid));
852
853 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
854 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
855 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
856}
857
858static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
859{
860 struct virtnet_info *vi = netdev_priv(dev);
861 struct scatterlist sg;
862
863 sg_init_one(&sg, &vid, sizeof(vid));
864
865 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
866 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
867 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
868}
869
870static const struct ethtool_ops virtnet_ethtool_ops = {
871 .get_link = ethtool_op_get_link,
872};
873
874#define MIN_MTU 68
875#define MAX_MTU 65535
876
877static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
878{
879 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
880 return -EINVAL;
881 dev->mtu = new_mtu;
882 return 0;
883}
884
885static const struct net_device_ops virtnet_netdev = {
886 .ndo_open = virtnet_open,
887 .ndo_stop = virtnet_close,
888 .ndo_start_xmit = start_xmit,
889 .ndo_validate_addr = eth_validate_addr,
890 .ndo_set_mac_address = virtnet_set_mac_address,
891 .ndo_set_rx_mode = virtnet_set_rx_mode,
892 .ndo_change_mtu = virtnet_change_mtu,
893 .ndo_get_stats64 = virtnet_stats,
894 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
895 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
896#ifdef CONFIG_NET_POLL_CONTROLLER
897 .ndo_poll_controller = virtnet_netpoll,
898#endif
899};
900
901static void virtnet_update_status(struct virtnet_info *vi)
902{
903 u16 v;
904
905 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
906 return;
907
908 vi->vdev->config->get(vi->vdev,
909 offsetof(struct virtio_net_config, status),
910 &v, sizeof(v));
911
912 /* Ignore unknown (future) status bits */
913 v &= VIRTIO_NET_S_LINK_UP;
914
915 if (vi->status == v)
916 return;
917
918 vi->status = v;
919
920 if (vi->status & VIRTIO_NET_S_LINK_UP) {
921 netif_carrier_on(vi->dev);
922 netif_wake_queue(vi->dev);
923 } else {
924 netif_carrier_off(vi->dev);
925 netif_stop_queue(vi->dev);
926 }
927}
928
929static void virtnet_config_changed(struct virtio_device *vdev)
930{
931 struct virtnet_info *vi = vdev->priv;
932
933 virtnet_update_status(vi);
934}
935
936static int virtnet_probe(struct virtio_device *vdev)
937{
938 int err;
939 struct net_device *dev;
940 struct virtnet_info *vi;
941 struct virtqueue *vqs[3];
942 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
943 const char *names[] = { "input", "output", "control" };
944 int nvqs;
945
946 /* Allocate ourselves a network device with room for our info */
947 dev = alloc_etherdev(sizeof(struct virtnet_info));
948 if (!dev)
949 return -ENOMEM;
950
951 /* Set up network device as normal. */
952 dev->netdev_ops = &virtnet_netdev;
953 dev->features = NETIF_F_HIGHDMA;
954
955 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
956 SET_NETDEV_DEV(dev, &vdev->dev);
957
958 /* Do we support "hardware" checksums? */
959 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
960 /* This opens up the world of extra features. */
961 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
962 if (csum)
963 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
964
965 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
966 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
967 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
968 }
969 /* Individual feature bits: what can host handle? */
970 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
971 dev->hw_features |= NETIF_F_TSO;
972 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
973 dev->hw_features |= NETIF_F_TSO6;
974 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
975 dev->hw_features |= NETIF_F_TSO_ECN;
976 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
977 dev->hw_features |= NETIF_F_UFO;
978
979 if (gso)
980 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
981 /* (!csum && gso) case will be fixed by register_netdev() */
982 }
983
984 /* Configuration may specify what MAC to use. Otherwise random. */
985 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
986 vdev->config->get(vdev,
987 offsetof(struct virtio_net_config, mac),
988 dev->dev_addr, dev->addr_len);
989 } else
990 random_ether_addr(dev->dev_addr);
991
992 /* Set up our device-specific information */
993 vi = netdev_priv(dev);
994 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
995 vi->dev = dev;
996 vi->vdev = vdev;
997 vdev->priv = vi;
998 vi->pages = NULL;
999 vi->stats = alloc_percpu(struct virtnet_stats);
1000 err = -ENOMEM;
1001 if (vi->stats == NULL)
1002 goto free;
1003
1004 INIT_DELAYED_WORK(&vi->refill, refill_work);
1005 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
1006 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
1007
1008 /* If we can receive ANY GSO packets, we must allocate large ones. */
1009 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1010 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1011 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1012 vi->big_packets = true;
1013
1014 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1015 vi->mergeable_rx_bufs = true;
1016
1017 /* We expect two virtqueues, receive then send,
1018 * and optionally control. */
1019 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
1020
1021 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
1022 if (err)
1023 goto free_stats;
1024
1025 vi->rvq = vqs[0];
1026 vi->svq = vqs[1];
1027
1028 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
1029 vi->cvq = vqs[2];
1030
1031 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1032 dev->features |= NETIF_F_HW_VLAN_FILTER;
1033 }
1034
1035 err = register_netdev(dev);
1036 if (err) {
1037 pr_debug("virtio_net: registering device failed\n");
1038 goto free_vqs;
1039 }
1040
1041 /* Last of all, set up some receive buffers. */
1042 try_fill_recv(vi, GFP_KERNEL);
1043
1044 /* If we didn't even get one input buffer, we're useless. */
1045 if (vi->num == 0) {
1046 err = -ENOMEM;
1047 goto unregister;
1048 }
1049
1050 /* Assume link up if device can't report link status,
1051 otherwise get link status from config. */
1052 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1053 netif_carrier_off(dev);
1054 virtnet_update_status(vi);
1055 } else {
1056 vi->status = VIRTIO_NET_S_LINK_UP;
1057 netif_carrier_on(dev);
1058 }
1059
1060 pr_debug("virtnet: registered device %s\n", dev->name);
1061 return 0;
1062
1063unregister:
1064 unregister_netdev(dev);
1065 cancel_delayed_work_sync(&vi->refill);
1066free_vqs:
1067 vdev->config->del_vqs(vdev);
1068free_stats:
1069 free_percpu(vi->stats);
1070free:
1071 free_netdev(dev);
1072 return err;
1073}
1074
1075static void free_unused_bufs(struct virtnet_info *vi)
1076{
1077 void *buf;
1078 while (1) {
1079 buf = virtqueue_detach_unused_buf(vi->svq);
1080 if (!buf)
1081 break;
1082 dev_kfree_skb(buf);
1083 }
1084 while (1) {
1085 buf = virtqueue_detach_unused_buf(vi->rvq);
1086 if (!buf)
1087 break;
1088 if (vi->mergeable_rx_bufs || vi->big_packets)
1089 give_pages(vi, buf);
1090 else
1091 dev_kfree_skb(buf);
1092 --vi->num;
1093 }
1094 BUG_ON(vi->num != 0);
1095}
1096
1097static void __devexit virtnet_remove(struct virtio_device *vdev)
1098{
1099 struct virtnet_info *vi = vdev->priv;
1100
1101 /* Stop all the virtqueues. */
1102 vdev->config->reset(vdev);
1103
1104
1105 unregister_netdev(vi->dev);
1106 cancel_delayed_work_sync(&vi->refill);
1107
1108 /* Free unused buffers in both send and recv, if any. */
1109 free_unused_bufs(vi);
1110
1111 vdev->config->del_vqs(vi->vdev);
1112
1113 while (vi->pages)
1114 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1115
1116 free_percpu(vi->stats);
1117 free_netdev(vi->dev);
1118}
1119
1120static struct virtio_device_id id_table[] = {
1121 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1122 { 0 },
1123};
1124
1125static unsigned int features[] = {
1126 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1127 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1128 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1129 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1130 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1131 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1132 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1133};
1134
1135static struct virtio_driver virtio_net_driver = {
1136 .feature_table = features,
1137 .feature_table_size = ARRAY_SIZE(features),
1138 .driver.name = KBUILD_MODNAME,
1139 .driver.owner = THIS_MODULE,
1140 .id_table = id_table,
1141 .probe = virtnet_probe,
1142 .remove = __devexit_p(virtnet_remove),
1143 .config_changed = virtnet_config_changed,
1144};
1145
1146static int __init init(void)
1147{
1148 return register_virtio_driver(&virtio_net_driver);
1149}
1150
1151static void __exit fini(void)
1152{
1153 unregister_virtio_driver(&virtio_net_driver);
1154}
1155module_init(init);
1156module_exit(fini);
1157
1158MODULE_DEVICE_TABLE(virtio, id_table);
1159MODULE_DESCRIPTION("Virtio network driver");
1160MODULE_LICENSE("GPL");
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
26static int napi_weight = NAPI_POLL_WEIGHT;
27module_param(napi_weight, int, 0444);
28
29static bool csum = true, gso = true, napi_tx = true;
30module_param(csum, bool, 0444);
31module_param(gso, bool, 0444);
32module_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 */
54DECLARE_EWMA(pkt_len, 0, 64)
55
56#define VIRTNET_DRIVER_VERSION "1.0.0"
57
58static 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};
65
66struct virtnet_stat_desc {
67 char desc[ETH_GSTRING_LEN];
68 size_t offset;
69};
70
71struct virtnet_sq_stats {
72 struct u64_stats_sync syncp;
73 u64 packets;
74 u64 bytes;
75 u64 xdp_tx;
76 u64 xdp_tx_drops;
77 u64 kicks;
78};
79
80struct virtnet_rq_stats {
81 struct u64_stats_sync syncp;
82 u64 packets;
83 u64 bytes;
84 u64 drops;
85 u64 xdp_packets;
86 u64 xdp_tx;
87 u64 xdp_redirects;
88 u64 xdp_drops;
89 u64 kicks;
90};
91
92#define VIRTNET_SQ_STAT(m) offsetof(struct virtnet_sq_stats, m)
93#define VIRTNET_RQ_STAT(m) offsetof(struct virtnet_rq_stats, m)
94
95static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
96 { "packets", VIRTNET_SQ_STAT(packets) },
97 { "bytes", VIRTNET_SQ_STAT(bytes) },
98 { "xdp_tx", VIRTNET_SQ_STAT(xdp_tx) },
99 { "xdp_tx_drops", VIRTNET_SQ_STAT(xdp_tx_drops) },
100 { "kicks", VIRTNET_SQ_STAT(kicks) },
101};
102
103static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
104 { "packets", VIRTNET_RQ_STAT(packets) },
105 { "bytes", VIRTNET_RQ_STAT(bytes) },
106 { "drops", VIRTNET_RQ_STAT(drops) },
107 { "xdp_packets", VIRTNET_RQ_STAT(xdp_packets) },
108 { "xdp_tx", VIRTNET_RQ_STAT(xdp_tx) },
109 { "xdp_redirects", VIRTNET_RQ_STAT(xdp_redirects) },
110 { "xdp_drops", VIRTNET_RQ_STAT(xdp_drops) },
111 { "kicks", VIRTNET_RQ_STAT(kicks) },
112};
113
114#define VIRTNET_SQ_STATS_LEN ARRAY_SIZE(virtnet_sq_stats_desc)
115#define VIRTNET_RQ_STATS_LEN ARRAY_SIZE(virtnet_rq_stats_desc)
116
117/* Internal representation of a send virtqueue */
118struct send_queue {
119 /* Virtqueue associated with this send _queue */
120 struct virtqueue *vq;
121
122 /* TX: fragments + linear part + virtio header */
123 struct scatterlist sg[MAX_SKB_FRAGS + 2];
124
125 /* Name of the send queue: output.$index */
126 char name[40];
127
128 struct virtnet_sq_stats stats;
129
130 struct napi_struct napi;
131};
132
133/* Internal representation of a receive virtqueue */
134struct receive_queue {
135 /* Virtqueue associated with this receive_queue */
136 struct virtqueue *vq;
137
138 struct napi_struct napi;
139
140 struct bpf_prog __rcu *xdp_prog;
141
142 struct virtnet_rq_stats stats;
143
144 /* Chain pages by the private ptr. */
145 struct page *pages;
146
147 /* Average packet length for mergeable receive buffers. */
148 struct ewma_pkt_len mrg_avg_pkt_len;
149
150 /* Page frag for packet buffer allocation. */
151 struct page_frag alloc_frag;
152
153 /* RX: fragments + linear part + virtio header */
154 struct scatterlist sg[MAX_SKB_FRAGS + 2];
155
156 /* Min single buffer size for mergeable buffers case. */
157 unsigned int min_buf_len;
158
159 /* Name of this receive queue: input.$index */
160 char name[40];
161
162 struct xdp_rxq_info xdp_rxq;
163};
164
165/* Control VQ buffers: protected by the rtnl lock */
166struct control_buf {
167 struct virtio_net_ctrl_hdr hdr;
168 virtio_net_ctrl_ack status;
169 struct virtio_net_ctrl_mq mq;
170 u8 promisc;
171 u8 allmulti;
172 __virtio16 vid;
173 __virtio64 offloads;
174};
175
176struct virtnet_info {
177 struct virtio_device *vdev;
178 struct virtqueue *cvq;
179 struct net_device *dev;
180 struct send_queue *sq;
181 struct receive_queue *rq;
182 unsigned int status;
183
184 /* Max # of queue pairs supported by the device */
185 u16 max_queue_pairs;
186
187 /* # of queue pairs currently used by the driver */
188 u16 curr_queue_pairs;
189
190 /* # of XDP queue pairs currently used by the driver */
191 u16 xdp_queue_pairs;
192
193 /* I like... big packets and I cannot lie! */
194 bool big_packets;
195
196 /* Host will merge rx buffers for big packets (shake it! shake it!) */
197 bool mergeable_rx_bufs;
198
199 /* Has control virtqueue */
200 bool has_cvq;
201
202 /* Host can handle any s/g split between our header and packet data */
203 bool any_header_sg;
204
205 /* Packet virtio header size */
206 u8 hdr_len;
207
208 /* Work struct for refilling if we run low on memory. */
209 struct delayed_work refill;
210
211 /* Work struct for config space updates */
212 struct work_struct config_work;
213
214 /* Does the affinity hint is set for virtqueues? */
215 bool affinity_hint_set;
216
217 /* CPU hotplug instances for online & dead */
218 struct hlist_node node;
219 struct hlist_node node_dead;
220
221 struct control_buf *ctrl;
222
223 /* Ethtool settings */
224 u8 duplex;
225 u32 speed;
226
227 unsigned long guest_offloads;
228 unsigned long guest_offloads_capable;
229
230 /* failover when STANDBY feature enabled */
231 struct failover *failover;
232};
233
234struct padded_vnet_hdr {
235 struct virtio_net_hdr_mrg_rxbuf hdr;
236 /*
237 * hdr is in a separate sg buffer, and data sg buffer shares same page
238 * with this header sg. This padding makes next sg 16 byte aligned
239 * after the header.
240 */
241 char padding[4];
242};
243
244static bool is_xdp_frame(void *ptr)
245{
246 return (unsigned long)ptr & VIRTIO_XDP_FLAG;
247}
248
249static void *xdp_to_ptr(struct xdp_frame *ptr)
250{
251 return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
252}
253
254static struct xdp_frame *ptr_to_xdp(void *ptr)
255{
256 return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
257}
258
259/* Converting between virtqueue no. and kernel tx/rx queue no.
260 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
261 */
262static int vq2txq(struct virtqueue *vq)
263{
264 return (vq->index - 1) / 2;
265}
266
267static int txq2vq(int txq)
268{
269 return txq * 2 + 1;
270}
271
272static int vq2rxq(struct virtqueue *vq)
273{
274 return vq->index / 2;
275}
276
277static int rxq2vq(int rxq)
278{
279 return rxq * 2;
280}
281
282static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
283{
284 return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
285}
286
287/*
288 * private is used to chain pages for big packets, put the whole
289 * most recent used list in the beginning for reuse
290 */
291static void give_pages(struct receive_queue *rq, struct page *page)
292{
293 struct page *end;
294
295 /* Find end of list, sew whole thing into vi->rq.pages. */
296 for (end = page; end->private; end = (struct page *)end->private);
297 end->private = (unsigned long)rq->pages;
298 rq->pages = page;
299}
300
301static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
302{
303 struct page *p = rq->pages;
304
305 if (p) {
306 rq->pages = (struct page *)p->private;
307 /* clear private here, it is used to chain pages */
308 p->private = 0;
309 } else
310 p = alloc_page(gfp_mask);
311 return p;
312}
313
314static void virtqueue_napi_schedule(struct napi_struct *napi,
315 struct virtqueue *vq)
316{
317 if (napi_schedule_prep(napi)) {
318 virtqueue_disable_cb(vq);
319 __napi_schedule(napi);
320 }
321}
322
323static void virtqueue_napi_complete(struct napi_struct *napi,
324 struct virtqueue *vq, int processed)
325{
326 int opaque;
327
328 opaque = virtqueue_enable_cb_prepare(vq);
329 if (napi_complete_done(napi, processed)) {
330 if (unlikely(virtqueue_poll(vq, opaque)))
331 virtqueue_napi_schedule(napi, vq);
332 } else {
333 virtqueue_disable_cb(vq);
334 }
335}
336
337static void skb_xmit_done(struct virtqueue *vq)
338{
339 struct virtnet_info *vi = vq->vdev->priv;
340 struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
341
342 /* Suppress further interrupts. */
343 virtqueue_disable_cb(vq);
344
345 if (napi->weight)
346 virtqueue_napi_schedule(napi, vq);
347 else
348 /* We were probably waiting for more output buffers. */
349 netif_wake_subqueue(vi->dev, vq2txq(vq));
350}
351
352#define MRG_CTX_HEADER_SHIFT 22
353static void *mergeable_len_to_ctx(unsigned int truesize,
354 unsigned int headroom)
355{
356 return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
357}
358
359static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
360{
361 return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
362}
363
364static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
365{
366 return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
367}
368
369/* Called from bottom half context */
370static struct sk_buff *page_to_skb(struct virtnet_info *vi,
371 struct receive_queue *rq,
372 struct page *page, unsigned int offset,
373 unsigned int len, unsigned int truesize,
374 bool hdr_valid)
375{
376 struct sk_buff *skb;
377 struct virtio_net_hdr_mrg_rxbuf *hdr;
378 unsigned int copy, hdr_len, hdr_padded_len;
379 char *p;
380
381 p = page_address(page) + offset;
382
383 /* copy small packet so we can reuse these pages for small data */
384 skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
385 if (unlikely(!skb))
386 return NULL;
387
388 hdr = skb_vnet_hdr(skb);
389
390 hdr_len = vi->hdr_len;
391 if (vi->mergeable_rx_bufs)
392 hdr_padded_len = sizeof(*hdr);
393 else
394 hdr_padded_len = sizeof(struct padded_vnet_hdr);
395
396 if (hdr_valid)
397 memcpy(hdr, p, hdr_len);
398
399 len -= hdr_len;
400 offset += hdr_padded_len;
401 p += hdr_padded_len;
402
403 copy = len;
404 if (copy > skb_tailroom(skb))
405 copy = skb_tailroom(skb);
406 skb_put_data(skb, p, copy);
407
408 len -= copy;
409 offset += copy;
410
411 if (vi->mergeable_rx_bufs) {
412 if (len)
413 skb_add_rx_frag(skb, 0, page, offset, len, truesize);
414 else
415 put_page(page);
416 return skb;
417 }
418
419 /*
420 * Verify that we can indeed put this data into a skb.
421 * This is here to handle cases when the device erroneously
422 * tries to receive more than is possible. This is usually
423 * the case of a broken device.
424 */
425 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
426 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
427 dev_kfree_skb(skb);
428 return NULL;
429 }
430 BUG_ON(offset >= PAGE_SIZE);
431 while (len) {
432 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
433 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
434 frag_size, truesize);
435 len -= frag_size;
436 page = (struct page *)page->private;
437 offset = 0;
438 }
439
440 if (page)
441 give_pages(rq, page);
442
443 return skb;
444}
445
446static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
447 struct send_queue *sq,
448 struct xdp_frame *xdpf)
449{
450 struct virtio_net_hdr_mrg_rxbuf *hdr;
451 int err;
452
453 /* virtqueue want to use data area in-front of packet */
454 if (unlikely(xdpf->metasize > 0))
455 return -EOPNOTSUPP;
456
457 if (unlikely(xdpf->headroom < vi->hdr_len))
458 return -EOVERFLOW;
459
460 /* Make room for virtqueue hdr (also change xdpf->headroom?) */
461 xdpf->data -= vi->hdr_len;
462 /* Zero header and leave csum up to XDP layers */
463 hdr = xdpf->data;
464 memset(hdr, 0, vi->hdr_len);
465 xdpf->len += vi->hdr_len;
466
467 sg_init_one(sq->sg, xdpf->data, xdpf->len);
468
469 err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
470 GFP_ATOMIC);
471 if (unlikely(err))
472 return -ENOSPC; /* Caller handle free/refcnt */
473
474 return 0;
475}
476
477static struct send_queue *virtnet_xdp_sq(struct virtnet_info *vi)
478{
479 unsigned int qp;
480
481 qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
482 return &vi->sq[qp];
483}
484
485static int virtnet_xdp_xmit(struct net_device *dev,
486 int n, struct xdp_frame **frames, u32 flags)
487{
488 struct virtnet_info *vi = netdev_priv(dev);
489 struct receive_queue *rq = vi->rq;
490 struct bpf_prog *xdp_prog;
491 struct send_queue *sq;
492 unsigned int len;
493 int packets = 0;
494 int bytes = 0;
495 int drops = 0;
496 int kicks = 0;
497 int ret, err;
498 void *ptr;
499 int i;
500
501 /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
502 * indicate XDP resources have been successfully allocated.
503 */
504 xdp_prog = rcu_dereference(rq->xdp_prog);
505 if (!xdp_prog)
506 return -ENXIO;
507
508 sq = virtnet_xdp_sq(vi);
509
510 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
511 ret = -EINVAL;
512 drops = n;
513 goto out;
514 }
515
516 /* Free up any pending old buffers before queueing new ones. */
517 while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
518 if (likely(is_xdp_frame(ptr))) {
519 struct xdp_frame *frame = ptr_to_xdp(ptr);
520
521 bytes += frame->len;
522 xdp_return_frame(frame);
523 } else {
524 struct sk_buff *skb = ptr;
525
526 bytes += skb->len;
527 napi_consume_skb(skb, false);
528 }
529 packets++;
530 }
531
532 for (i = 0; i < n; i++) {
533 struct xdp_frame *xdpf = frames[i];
534
535 err = __virtnet_xdp_xmit_one(vi, sq, xdpf);
536 if (err) {
537 xdp_return_frame_rx_napi(xdpf);
538 drops++;
539 }
540 }
541 ret = n - drops;
542
543 if (flags & XDP_XMIT_FLUSH) {
544 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
545 kicks = 1;
546 }
547out:
548 u64_stats_update_begin(&sq->stats.syncp);
549 sq->stats.bytes += bytes;
550 sq->stats.packets += packets;
551 sq->stats.xdp_tx += n;
552 sq->stats.xdp_tx_drops += drops;
553 sq->stats.kicks += kicks;
554 u64_stats_update_end(&sq->stats.syncp);
555
556 return ret;
557}
558
559static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
560{
561 return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
562}
563
564/* We copy the packet for XDP in the following cases:
565 *
566 * 1) Packet is scattered across multiple rx buffers.
567 * 2) Headroom space is insufficient.
568 *
569 * This is inefficient but it's a temporary condition that
570 * we hit right after XDP is enabled and until queue is refilled
571 * with large buffers with sufficient headroom - so it should affect
572 * at most queue size packets.
573 * Afterwards, the conditions to enable
574 * XDP should preclude the underlying device from sending packets
575 * across multiple buffers (num_buf > 1), and we make sure buffers
576 * have enough headroom.
577 */
578static struct page *xdp_linearize_page(struct receive_queue *rq,
579 u16 *num_buf,
580 struct page *p,
581 int offset,
582 int page_off,
583 unsigned int *len)
584{
585 struct page *page = alloc_page(GFP_ATOMIC);
586
587 if (!page)
588 return NULL;
589
590 memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
591 page_off += *len;
592
593 while (--*num_buf) {
594 int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
595 unsigned int buflen;
596 void *buf;
597 int off;
598
599 buf = virtqueue_get_buf(rq->vq, &buflen);
600 if (unlikely(!buf))
601 goto err_buf;
602
603 p = virt_to_head_page(buf);
604 off = buf - page_address(p);
605
606 /* guard against a misconfigured or uncooperative backend that
607 * is sending packet larger than the MTU.
608 */
609 if ((page_off + buflen + tailroom) > PAGE_SIZE) {
610 put_page(p);
611 goto err_buf;
612 }
613
614 memcpy(page_address(page) + page_off,
615 page_address(p) + off, buflen);
616 page_off += buflen;
617 put_page(p);
618 }
619
620 /* Headroom does not contribute to packet length */
621 *len = page_off - VIRTIO_XDP_HEADROOM;
622 return page;
623err_buf:
624 __free_pages(page, 0);
625 return NULL;
626}
627
628static struct sk_buff *receive_small(struct net_device *dev,
629 struct virtnet_info *vi,
630 struct receive_queue *rq,
631 void *buf, void *ctx,
632 unsigned int len,
633 unsigned int *xdp_xmit,
634 struct virtnet_rq_stats *stats)
635{
636 struct sk_buff *skb;
637 struct bpf_prog *xdp_prog;
638 unsigned int xdp_headroom = (unsigned long)ctx;
639 unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
640 unsigned int headroom = vi->hdr_len + header_offset;
641 unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
642 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
643 struct page *page = virt_to_head_page(buf);
644 unsigned int delta = 0;
645 struct page *xdp_page;
646 int err;
647
648 len -= vi->hdr_len;
649 stats->bytes += len;
650
651 rcu_read_lock();
652 xdp_prog = rcu_dereference(rq->xdp_prog);
653 if (xdp_prog) {
654 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
655 struct xdp_frame *xdpf;
656 struct xdp_buff xdp;
657 void *orig_data;
658 u32 act;
659
660 if (unlikely(hdr->hdr.gso_type))
661 goto err_xdp;
662
663 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
664 int offset = buf - page_address(page) + header_offset;
665 unsigned int tlen = len + vi->hdr_len;
666 u16 num_buf = 1;
667
668 xdp_headroom = virtnet_get_headroom(vi);
669 header_offset = VIRTNET_RX_PAD + xdp_headroom;
670 headroom = vi->hdr_len + header_offset;
671 buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
672 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
673 xdp_page = xdp_linearize_page(rq, &num_buf, page,
674 offset, header_offset,
675 &tlen);
676 if (!xdp_page)
677 goto err_xdp;
678
679 buf = page_address(xdp_page);
680 put_page(page);
681 page = xdp_page;
682 }
683
684 xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
685 xdp.data = xdp.data_hard_start + xdp_headroom;
686 xdp_set_data_meta_invalid(&xdp);
687 xdp.data_end = xdp.data + len;
688 xdp.rxq = &rq->xdp_rxq;
689 orig_data = xdp.data;
690 act = bpf_prog_run_xdp(xdp_prog, &xdp);
691 stats->xdp_packets++;
692
693 switch (act) {
694 case XDP_PASS:
695 /* Recalculate length in case bpf program changed it */
696 delta = orig_data - xdp.data;
697 len = xdp.data_end - xdp.data;
698 break;
699 case XDP_TX:
700 stats->xdp_tx++;
701 xdpf = convert_to_xdp_frame(&xdp);
702 if (unlikely(!xdpf))
703 goto err_xdp;
704 err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
705 if (unlikely(err < 0)) {
706 trace_xdp_exception(vi->dev, xdp_prog, act);
707 goto err_xdp;
708 }
709 *xdp_xmit |= VIRTIO_XDP_TX;
710 rcu_read_unlock();
711 goto xdp_xmit;
712 case XDP_REDIRECT:
713 stats->xdp_redirects++;
714 err = xdp_do_redirect(dev, &xdp, xdp_prog);
715 if (err)
716 goto err_xdp;
717 *xdp_xmit |= VIRTIO_XDP_REDIR;
718 rcu_read_unlock();
719 goto xdp_xmit;
720 default:
721 bpf_warn_invalid_xdp_action(act);
722 /* fall through */
723 case XDP_ABORTED:
724 trace_xdp_exception(vi->dev, xdp_prog, act);
725 case XDP_DROP:
726 goto err_xdp;
727 }
728 }
729 rcu_read_unlock();
730
731 skb = build_skb(buf, buflen);
732 if (!skb) {
733 put_page(page);
734 goto err;
735 }
736 skb_reserve(skb, headroom - delta);
737 skb_put(skb, len);
738 if (!delta) {
739 buf += header_offset;
740 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
741 } /* keep zeroed vnet hdr since packet was changed by bpf */
742
743err:
744 return skb;
745
746err_xdp:
747 rcu_read_unlock();
748 stats->xdp_drops++;
749 stats->drops++;
750 put_page(page);
751xdp_xmit:
752 return NULL;
753}
754
755static struct sk_buff *receive_big(struct net_device *dev,
756 struct virtnet_info *vi,
757 struct receive_queue *rq,
758 void *buf,
759 unsigned int len,
760 struct virtnet_rq_stats *stats)
761{
762 struct page *page = buf;
763 struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len,
764 PAGE_SIZE, true);
765
766 stats->bytes += len - vi->hdr_len;
767 if (unlikely(!skb))
768 goto err;
769
770 return skb;
771
772err:
773 stats->drops++;
774 give_pages(rq, page);
775 return NULL;
776}
777
778static struct sk_buff *receive_mergeable(struct net_device *dev,
779 struct virtnet_info *vi,
780 struct receive_queue *rq,
781 void *buf,
782 void *ctx,
783 unsigned int len,
784 unsigned int *xdp_xmit,
785 struct virtnet_rq_stats *stats)
786{
787 struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
788 u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
789 struct page *page = virt_to_head_page(buf);
790 int offset = buf - page_address(page);
791 struct sk_buff *head_skb, *curr_skb;
792 struct bpf_prog *xdp_prog;
793 unsigned int truesize;
794 unsigned int headroom = mergeable_ctx_to_headroom(ctx);
795 int err;
796
797 head_skb = NULL;
798 stats->bytes += len - vi->hdr_len;
799
800 rcu_read_lock();
801 xdp_prog = rcu_dereference(rq->xdp_prog);
802 if (xdp_prog) {
803 struct xdp_frame *xdpf;
804 struct page *xdp_page;
805 struct xdp_buff xdp;
806 void *data;
807 u32 act;
808
809 /* Transient failure which in theory could occur if
810 * in-flight packets from before XDP was enabled reach
811 * the receive path after XDP is loaded.
812 */
813 if (unlikely(hdr->hdr.gso_type))
814 goto err_xdp;
815
816 /* This happens when rx buffer size is underestimated
817 * or headroom is not enough because of the buffer
818 * was refilled before XDP is set. This should only
819 * happen for the first several packets, so we don't
820 * care much about its performance.
821 */
822 if (unlikely(num_buf > 1 ||
823 headroom < virtnet_get_headroom(vi))) {
824 /* linearize data for XDP */
825 xdp_page = xdp_linearize_page(rq, &num_buf,
826 page, offset,
827 VIRTIO_XDP_HEADROOM,
828 &len);
829 if (!xdp_page)
830 goto err_xdp;
831 offset = VIRTIO_XDP_HEADROOM;
832 } else {
833 xdp_page = page;
834 }
835
836 /* Allow consuming headroom but reserve enough space to push
837 * the descriptor on if we get an XDP_TX return code.
838 */
839 data = page_address(xdp_page) + offset;
840 xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
841 xdp.data = data + vi->hdr_len;
842 xdp_set_data_meta_invalid(&xdp);
843 xdp.data_end = xdp.data + (len - vi->hdr_len);
844 xdp.rxq = &rq->xdp_rxq;
845
846 act = bpf_prog_run_xdp(xdp_prog, &xdp);
847 stats->xdp_packets++;
848
849 switch (act) {
850 case XDP_PASS:
851 /* recalculate offset to account for any header
852 * adjustments. Note other cases do not build an
853 * skb and avoid using offset
854 */
855 offset = xdp.data -
856 page_address(xdp_page) - vi->hdr_len;
857
858 /* recalculate len if xdp.data or xdp.data_end were
859 * adjusted
860 */
861 len = xdp.data_end - xdp.data + vi->hdr_len;
862 /* We can only create skb based on xdp_page. */
863 if (unlikely(xdp_page != page)) {
864 rcu_read_unlock();
865 put_page(page);
866 head_skb = page_to_skb(vi, rq, xdp_page,
867 offset, len,
868 PAGE_SIZE, false);
869 return head_skb;
870 }
871 break;
872 case XDP_TX:
873 stats->xdp_tx++;
874 xdpf = convert_to_xdp_frame(&xdp);
875 if (unlikely(!xdpf))
876 goto err_xdp;
877 err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
878 if (unlikely(err < 0)) {
879 trace_xdp_exception(vi->dev, xdp_prog, act);
880 if (unlikely(xdp_page != page))
881 put_page(xdp_page);
882 goto err_xdp;
883 }
884 *xdp_xmit |= VIRTIO_XDP_TX;
885 if (unlikely(xdp_page != page))
886 put_page(page);
887 rcu_read_unlock();
888 goto xdp_xmit;
889 case XDP_REDIRECT:
890 stats->xdp_redirects++;
891 err = xdp_do_redirect(dev, &xdp, xdp_prog);
892 if (err) {
893 if (unlikely(xdp_page != page))
894 put_page(xdp_page);
895 goto err_xdp;
896 }
897 *xdp_xmit |= VIRTIO_XDP_REDIR;
898 if (unlikely(xdp_page != page))
899 put_page(page);
900 rcu_read_unlock();
901 goto xdp_xmit;
902 default:
903 bpf_warn_invalid_xdp_action(act);
904 /* fall through */
905 case XDP_ABORTED:
906 trace_xdp_exception(vi->dev, xdp_prog, act);
907 /* fall through */
908 case XDP_DROP:
909 if (unlikely(xdp_page != page))
910 __free_pages(xdp_page, 0);
911 goto err_xdp;
912 }
913 }
914 rcu_read_unlock();
915
916 truesize = mergeable_ctx_to_truesize(ctx);
917 if (unlikely(len > truesize)) {
918 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
919 dev->name, len, (unsigned long)ctx);
920 dev->stats.rx_length_errors++;
921 goto err_skb;
922 }
923
924 head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog);
925 curr_skb = head_skb;
926
927 if (unlikely(!curr_skb))
928 goto err_skb;
929 while (--num_buf) {
930 int num_skb_frags;
931
932 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
933 if (unlikely(!buf)) {
934 pr_debug("%s: rx error: %d buffers out of %d missing\n",
935 dev->name, num_buf,
936 virtio16_to_cpu(vi->vdev,
937 hdr->num_buffers));
938 dev->stats.rx_length_errors++;
939 goto err_buf;
940 }
941
942 stats->bytes += len;
943 page = virt_to_head_page(buf);
944
945 truesize = mergeable_ctx_to_truesize(ctx);
946 if (unlikely(len > truesize)) {
947 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
948 dev->name, len, (unsigned long)ctx);
949 dev->stats.rx_length_errors++;
950 goto err_skb;
951 }
952
953 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
954 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
955 struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
956
957 if (unlikely(!nskb))
958 goto err_skb;
959 if (curr_skb == head_skb)
960 skb_shinfo(curr_skb)->frag_list = nskb;
961 else
962 curr_skb->next = nskb;
963 curr_skb = nskb;
964 head_skb->truesize += nskb->truesize;
965 num_skb_frags = 0;
966 }
967 if (curr_skb != head_skb) {
968 head_skb->data_len += len;
969 head_skb->len += len;
970 head_skb->truesize += truesize;
971 }
972 offset = buf - page_address(page);
973 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
974 put_page(page);
975 skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
976 len, truesize);
977 } else {
978 skb_add_rx_frag(curr_skb, num_skb_frags, page,
979 offset, len, truesize);
980 }
981 }
982
983 ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
984 return head_skb;
985
986err_xdp:
987 rcu_read_unlock();
988 stats->xdp_drops++;
989err_skb:
990 put_page(page);
991 while (num_buf-- > 1) {
992 buf = virtqueue_get_buf(rq->vq, &len);
993 if (unlikely(!buf)) {
994 pr_debug("%s: rx error: %d buffers missing\n",
995 dev->name, num_buf);
996 dev->stats.rx_length_errors++;
997 break;
998 }
999 stats->bytes += len;
1000 page = virt_to_head_page(buf);
1001 put_page(page);
1002 }
1003err_buf:
1004 stats->drops++;
1005 dev_kfree_skb(head_skb);
1006xdp_xmit:
1007 return NULL;
1008}
1009
1010static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1011 void *buf, unsigned int len, void **ctx,
1012 unsigned int *xdp_xmit,
1013 struct virtnet_rq_stats *stats)
1014{
1015 struct net_device *dev = vi->dev;
1016 struct sk_buff *skb;
1017 struct virtio_net_hdr_mrg_rxbuf *hdr;
1018
1019 if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1020 pr_debug("%s: short packet %i\n", dev->name, len);
1021 dev->stats.rx_length_errors++;
1022 if (vi->mergeable_rx_bufs) {
1023 put_page(virt_to_head_page(buf));
1024 } else if (vi->big_packets) {
1025 give_pages(rq, buf);
1026 } else {
1027 put_page(virt_to_head_page(buf));
1028 }
1029 return;
1030 }
1031
1032 if (vi->mergeable_rx_bufs)
1033 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1034 stats);
1035 else if (vi->big_packets)
1036 skb = receive_big(dev, vi, rq, buf, len, stats);
1037 else
1038 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1039
1040 if (unlikely(!skb))
1041 return;
1042
1043 hdr = skb_vnet_hdr(skb);
1044
1045 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1046 skb->ip_summed = CHECKSUM_UNNECESSARY;
1047
1048 if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1049 virtio_is_little_endian(vi->vdev))) {
1050 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1051 dev->name, hdr->hdr.gso_type,
1052 hdr->hdr.gso_size);
1053 goto frame_err;
1054 }
1055
1056 skb_record_rx_queue(skb, vq2rxq(rq->vq));
1057 skb->protocol = eth_type_trans(skb, dev);
1058 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1059 ntohs(skb->protocol), skb->len, skb->pkt_type);
1060
1061 napi_gro_receive(&rq->napi, skb);
1062 return;
1063
1064frame_err:
1065 dev->stats.rx_frame_errors++;
1066 dev_kfree_skb(skb);
1067}
1068
1069/* Unlike mergeable buffers, all buffers are allocated to the
1070 * same size, except for the headroom. For this reason we do
1071 * not need to use mergeable_len_to_ctx here - it is enough
1072 * to store the headroom as the context ignoring the truesize.
1073 */
1074static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1075 gfp_t gfp)
1076{
1077 struct page_frag *alloc_frag = &rq->alloc_frag;
1078 char *buf;
1079 unsigned int xdp_headroom = virtnet_get_headroom(vi);
1080 void *ctx = (void *)(unsigned long)xdp_headroom;
1081 int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1082 int err;
1083
1084 len = SKB_DATA_ALIGN(len) +
1085 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1086 if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1087 return -ENOMEM;
1088
1089 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1090 get_page(alloc_frag->page);
1091 alloc_frag->offset += len;
1092 sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1093 vi->hdr_len + GOOD_PACKET_LEN);
1094 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1095 if (err < 0)
1096 put_page(virt_to_head_page(buf));
1097 return err;
1098}
1099
1100static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1101 gfp_t gfp)
1102{
1103 struct page *first, *list = NULL;
1104 char *p;
1105 int i, err, offset;
1106
1107 sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
1108
1109 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
1110 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
1111 first = get_a_page(rq, gfp);
1112 if (!first) {
1113 if (list)
1114 give_pages(rq, list);
1115 return -ENOMEM;
1116 }
1117 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1118
1119 /* chain new page in list head to match sg */
1120 first->private = (unsigned long)list;
1121 list = first;
1122 }
1123
1124 first = get_a_page(rq, gfp);
1125 if (!first) {
1126 give_pages(rq, list);
1127 return -ENOMEM;
1128 }
1129 p = page_address(first);
1130
1131 /* rq->sg[0], rq->sg[1] share the same page */
1132 /* a separated rq->sg[0] for header - required in case !any_header_sg */
1133 sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1134
1135 /* rq->sg[1] for data packet, from offset */
1136 offset = sizeof(struct padded_vnet_hdr);
1137 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1138
1139 /* chain first in list head */
1140 first->private = (unsigned long)list;
1141 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
1142 first, gfp);
1143 if (err < 0)
1144 give_pages(rq, first);
1145
1146 return err;
1147}
1148
1149static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1150 struct ewma_pkt_len *avg_pkt_len,
1151 unsigned int room)
1152{
1153 const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1154 unsigned int len;
1155
1156 if (room)
1157 return PAGE_SIZE - room;
1158
1159 len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1160 rq->min_buf_len, PAGE_SIZE - hdr_len);
1161
1162 return ALIGN(len, L1_CACHE_BYTES);
1163}
1164
1165static int add_recvbuf_mergeable(struct virtnet_info *vi,
1166 struct receive_queue *rq, gfp_t gfp)
1167{
1168 struct page_frag *alloc_frag = &rq->alloc_frag;
1169 unsigned int headroom = virtnet_get_headroom(vi);
1170 unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1171 unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1172 char *buf;
1173 void *ctx;
1174 int err;
1175 unsigned int len, hole;
1176
1177 /* Extra tailroom is needed to satisfy XDP's assumption. This
1178 * means rx frags coalescing won't work, but consider we've
1179 * disabled GSO for XDP, it won't be a big issue.
1180 */
1181 len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1182 if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1183 return -ENOMEM;
1184
1185 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1186 buf += headroom; /* advance address leaving hole at front of pkt */
1187 get_page(alloc_frag->page);
1188 alloc_frag->offset += len + room;
1189 hole = alloc_frag->size - alloc_frag->offset;
1190 if (hole < len + room) {
1191 /* To avoid internal fragmentation, if there is very likely not
1192 * enough space for another buffer, add the remaining space to
1193 * the current buffer.
1194 */
1195 len += hole;
1196 alloc_frag->offset += hole;
1197 }
1198
1199 sg_init_one(rq->sg, buf, len);
1200 ctx = mergeable_len_to_ctx(len, headroom);
1201 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1202 if (err < 0)
1203 put_page(virt_to_head_page(buf));
1204
1205 return err;
1206}
1207
1208/*
1209 * Returns false if we couldn't fill entirely (OOM).
1210 *
1211 * Normally run in the receive path, but can also be run from ndo_open
1212 * before we're receiving packets, or from refill_work which is
1213 * careful to disable receiving (using napi_disable).
1214 */
1215static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1216 gfp_t gfp)
1217{
1218 int err;
1219 bool oom;
1220
1221 do {
1222 if (vi->mergeable_rx_bufs)
1223 err = add_recvbuf_mergeable(vi, rq, gfp);
1224 else if (vi->big_packets)
1225 err = add_recvbuf_big(vi, rq, gfp);
1226 else
1227 err = add_recvbuf_small(vi, rq, gfp);
1228
1229 oom = err == -ENOMEM;
1230 if (err)
1231 break;
1232 } while (rq->vq->num_free);
1233 if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1234 u64_stats_update_begin(&rq->stats.syncp);
1235 rq->stats.kicks++;
1236 u64_stats_update_end(&rq->stats.syncp);
1237 }
1238
1239 return !oom;
1240}
1241
1242static void skb_recv_done(struct virtqueue *rvq)
1243{
1244 struct virtnet_info *vi = rvq->vdev->priv;
1245 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1246
1247 virtqueue_napi_schedule(&rq->napi, rvq);
1248}
1249
1250static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1251{
1252 napi_enable(napi);
1253
1254 /* If all buffers were filled by other side before we napi_enabled, we
1255 * won't get another interrupt, so process any outstanding packets now.
1256 * Call local_bh_enable after to trigger softIRQ processing.
1257 */
1258 local_bh_disable();
1259 virtqueue_napi_schedule(napi, vq);
1260 local_bh_enable();
1261}
1262
1263static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1264 struct virtqueue *vq,
1265 struct napi_struct *napi)
1266{
1267 if (!napi->weight)
1268 return;
1269
1270 /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1271 * enable the feature if this is likely affine with the transmit path.
1272 */
1273 if (!vi->affinity_hint_set) {
1274 napi->weight = 0;
1275 return;
1276 }
1277
1278 return virtnet_napi_enable(vq, napi);
1279}
1280
1281static void virtnet_napi_tx_disable(struct napi_struct *napi)
1282{
1283 if (napi->weight)
1284 napi_disable(napi);
1285}
1286
1287static void refill_work(struct work_struct *work)
1288{
1289 struct virtnet_info *vi =
1290 container_of(work, struct virtnet_info, refill.work);
1291 bool still_empty;
1292 int i;
1293
1294 for (i = 0; i < vi->curr_queue_pairs; i++) {
1295 struct receive_queue *rq = &vi->rq[i];
1296
1297 napi_disable(&rq->napi);
1298 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1299 virtnet_napi_enable(rq->vq, &rq->napi);
1300
1301 /* In theory, this can happen: if we don't get any buffers in
1302 * we will *never* try to fill again.
1303 */
1304 if (still_empty)
1305 schedule_delayed_work(&vi->refill, HZ/2);
1306 }
1307}
1308
1309static int virtnet_receive(struct receive_queue *rq, int budget,
1310 unsigned int *xdp_xmit)
1311{
1312 struct virtnet_info *vi = rq->vq->vdev->priv;
1313 struct virtnet_rq_stats stats = {};
1314 unsigned int len;
1315 void *buf;
1316 int i;
1317
1318 if (!vi->big_packets || vi->mergeable_rx_bufs) {
1319 void *ctx;
1320
1321 while (stats.packets < budget &&
1322 (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1323 receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1324 stats.packets++;
1325 }
1326 } else {
1327 while (stats.packets < budget &&
1328 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1329 receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1330 stats.packets++;
1331 }
1332 }
1333
1334 if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1335 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1336 schedule_delayed_work(&vi->refill, 0);
1337 }
1338
1339 u64_stats_update_begin(&rq->stats.syncp);
1340 for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1341 size_t offset = virtnet_rq_stats_desc[i].offset;
1342 u64 *item;
1343
1344 item = (u64 *)((u8 *)&rq->stats + offset);
1345 *item += *(u64 *)((u8 *)&stats + offset);
1346 }
1347 u64_stats_update_end(&rq->stats.syncp);
1348
1349 return stats.packets;
1350}
1351
1352static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
1353{
1354 unsigned int len;
1355 unsigned int packets = 0;
1356 unsigned int bytes = 0;
1357 void *ptr;
1358
1359 while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1360 if (likely(!is_xdp_frame(ptr))) {
1361 struct sk_buff *skb = ptr;
1362
1363 pr_debug("Sent skb %p\n", skb);
1364
1365 bytes += skb->len;
1366 napi_consume_skb(skb, in_napi);
1367 } else {
1368 struct xdp_frame *frame = ptr_to_xdp(ptr);
1369
1370 bytes += frame->len;
1371 xdp_return_frame(frame);
1372 }
1373 packets++;
1374 }
1375
1376 /* Avoid overhead when no packets have been processed
1377 * happens when called speculatively from start_xmit.
1378 */
1379 if (!packets)
1380 return;
1381
1382 u64_stats_update_begin(&sq->stats.syncp);
1383 sq->stats.bytes += bytes;
1384 sq->stats.packets += packets;
1385 u64_stats_update_end(&sq->stats.syncp);
1386}
1387
1388static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
1389{
1390 if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
1391 return false;
1392 else if (q < vi->curr_queue_pairs)
1393 return true;
1394 else
1395 return false;
1396}
1397
1398static void virtnet_poll_cleantx(struct receive_queue *rq)
1399{
1400 struct virtnet_info *vi = rq->vq->vdev->priv;
1401 unsigned int index = vq2rxq(rq->vq);
1402 struct send_queue *sq = &vi->sq[index];
1403 struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1404
1405 if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1406 return;
1407
1408 if (__netif_tx_trylock(txq)) {
1409 free_old_xmit_skbs(sq, true);
1410 __netif_tx_unlock(txq);
1411 }
1412
1413 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1414 netif_tx_wake_queue(txq);
1415}
1416
1417static int virtnet_poll(struct napi_struct *napi, int budget)
1418{
1419 struct receive_queue *rq =
1420 container_of(napi, struct receive_queue, napi);
1421 struct virtnet_info *vi = rq->vq->vdev->priv;
1422 struct send_queue *sq;
1423 unsigned int received;
1424 unsigned int xdp_xmit = 0;
1425
1426 virtnet_poll_cleantx(rq);
1427
1428 received = virtnet_receive(rq, budget, &xdp_xmit);
1429
1430 /* Out of packets? */
1431 if (received < budget)
1432 virtqueue_napi_complete(napi, rq->vq, received);
1433
1434 if (xdp_xmit & VIRTIO_XDP_REDIR)
1435 xdp_do_flush_map();
1436
1437 if (xdp_xmit & VIRTIO_XDP_TX) {
1438 sq = virtnet_xdp_sq(vi);
1439 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1440 u64_stats_update_begin(&sq->stats.syncp);
1441 sq->stats.kicks++;
1442 u64_stats_update_end(&sq->stats.syncp);
1443 }
1444 }
1445
1446 return received;
1447}
1448
1449static int virtnet_open(struct net_device *dev)
1450{
1451 struct virtnet_info *vi = netdev_priv(dev);
1452 int i, err;
1453
1454 for (i = 0; i < vi->max_queue_pairs; i++) {
1455 if (i < vi->curr_queue_pairs)
1456 /* Make sure we have some buffers: if oom use wq. */
1457 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1458 schedule_delayed_work(&vi->refill, 0);
1459
1460 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i);
1461 if (err < 0)
1462 return err;
1463
1464 err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1465 MEM_TYPE_PAGE_SHARED, NULL);
1466 if (err < 0) {
1467 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1468 return err;
1469 }
1470
1471 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1472 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1473 }
1474
1475 return 0;
1476}
1477
1478static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1479{
1480 struct send_queue *sq = container_of(napi, struct send_queue, napi);
1481 struct virtnet_info *vi = sq->vq->vdev->priv;
1482 unsigned int index = vq2txq(sq->vq);
1483 struct netdev_queue *txq;
1484
1485 if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1486 /* We don't need to enable cb for XDP */
1487 napi_complete_done(napi, 0);
1488 return 0;
1489 }
1490
1491 txq = netdev_get_tx_queue(vi->dev, index);
1492 __netif_tx_lock(txq, raw_smp_processor_id());
1493 free_old_xmit_skbs(sq, true);
1494 __netif_tx_unlock(txq);
1495
1496 virtqueue_napi_complete(napi, sq->vq, 0);
1497
1498 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1499 netif_tx_wake_queue(txq);
1500
1501 return 0;
1502}
1503
1504static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1505{
1506 struct virtio_net_hdr_mrg_rxbuf *hdr;
1507 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1508 struct virtnet_info *vi = sq->vq->vdev->priv;
1509 int num_sg;
1510 unsigned hdr_len = vi->hdr_len;
1511 bool can_push;
1512
1513 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1514
1515 can_push = vi->any_header_sg &&
1516 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1517 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1518 /* Even if we can, don't push here yet as this would skew
1519 * csum_start offset below. */
1520 if (can_push)
1521 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1522 else
1523 hdr = skb_vnet_hdr(skb);
1524
1525 if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1526 virtio_is_little_endian(vi->vdev), false,
1527 0))
1528 BUG();
1529
1530 if (vi->mergeable_rx_bufs)
1531 hdr->num_buffers = 0;
1532
1533 sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1534 if (can_push) {
1535 __skb_push(skb, hdr_len);
1536 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1537 if (unlikely(num_sg < 0))
1538 return num_sg;
1539 /* Pull header back to avoid skew in tx bytes calculations. */
1540 __skb_pull(skb, hdr_len);
1541 } else {
1542 sg_set_buf(sq->sg, hdr, hdr_len);
1543 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1544 if (unlikely(num_sg < 0))
1545 return num_sg;
1546 num_sg++;
1547 }
1548 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1549}
1550
1551static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1552{
1553 struct virtnet_info *vi = netdev_priv(dev);
1554 int qnum = skb_get_queue_mapping(skb);
1555 struct send_queue *sq = &vi->sq[qnum];
1556 int err;
1557 struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1558 bool kick = !netdev_xmit_more();
1559 bool use_napi = sq->napi.weight;
1560
1561 /* Free up any pending old buffers before queueing new ones. */
1562 free_old_xmit_skbs(sq, false);
1563
1564 if (use_napi && kick)
1565 virtqueue_enable_cb_delayed(sq->vq);
1566
1567 /* timestamp packet in software */
1568 skb_tx_timestamp(skb);
1569
1570 /* Try to transmit */
1571 err = xmit_skb(sq, skb);
1572
1573 /* This should not happen! */
1574 if (unlikely(err)) {
1575 dev->stats.tx_fifo_errors++;
1576 if (net_ratelimit())
1577 dev_warn(&dev->dev,
1578 "Unexpected TXQ (%d) queue failure: %d\n",
1579 qnum, err);
1580 dev->stats.tx_dropped++;
1581 dev_kfree_skb_any(skb);
1582 return NETDEV_TX_OK;
1583 }
1584
1585 /* Don't wait up for transmitted skbs to be freed. */
1586 if (!use_napi) {
1587 skb_orphan(skb);
1588 nf_reset_ct(skb);
1589 }
1590
1591 /* If running out of space, stop queue to avoid getting packets that we
1592 * are then unable to transmit.
1593 * An alternative would be to force queuing layer to requeue the skb by
1594 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1595 * returned in a normal path of operation: it means that driver is not
1596 * maintaining the TX queue stop/start state properly, and causes
1597 * the stack to do a non-trivial amount of useless work.
1598 * Since most packets only take 1 or 2 ring slots, stopping the queue
1599 * early means 16 slots are typically wasted.
1600 */
1601 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1602 netif_stop_subqueue(dev, qnum);
1603 if (!use_napi &&
1604 unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1605 /* More just got used, free them then recheck. */
1606 free_old_xmit_skbs(sq, false);
1607 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1608 netif_start_subqueue(dev, qnum);
1609 virtqueue_disable_cb(sq->vq);
1610 }
1611 }
1612 }
1613
1614 if (kick || netif_xmit_stopped(txq)) {
1615 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1616 u64_stats_update_begin(&sq->stats.syncp);
1617 sq->stats.kicks++;
1618 u64_stats_update_end(&sq->stats.syncp);
1619 }
1620 }
1621
1622 return NETDEV_TX_OK;
1623}
1624
1625/*
1626 * Send command via the control virtqueue and check status. Commands
1627 * supported by the hypervisor, as indicated by feature bits, should
1628 * never fail unless improperly formatted.
1629 */
1630static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1631 struct scatterlist *out)
1632{
1633 struct scatterlist *sgs[4], hdr, stat;
1634 unsigned out_num = 0, tmp;
1635
1636 /* Caller should know better */
1637 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1638
1639 vi->ctrl->status = ~0;
1640 vi->ctrl->hdr.class = class;
1641 vi->ctrl->hdr.cmd = cmd;
1642 /* Add header */
1643 sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1644 sgs[out_num++] = &hdr;
1645
1646 if (out)
1647 sgs[out_num++] = out;
1648
1649 /* Add return status. */
1650 sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1651 sgs[out_num] = &stat;
1652
1653 BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1654 virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1655
1656 if (unlikely(!virtqueue_kick(vi->cvq)))
1657 return vi->ctrl->status == VIRTIO_NET_OK;
1658
1659 /* Spin for a response, the kick causes an ioport write, trapping
1660 * into the hypervisor, so the request should be handled immediately.
1661 */
1662 while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1663 !virtqueue_is_broken(vi->cvq))
1664 cpu_relax();
1665
1666 return vi->ctrl->status == VIRTIO_NET_OK;
1667}
1668
1669static int virtnet_set_mac_address(struct net_device *dev, void *p)
1670{
1671 struct virtnet_info *vi = netdev_priv(dev);
1672 struct virtio_device *vdev = vi->vdev;
1673 int ret;
1674 struct sockaddr *addr;
1675 struct scatterlist sg;
1676
1677 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
1678 return -EOPNOTSUPP;
1679
1680 addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1681 if (!addr)
1682 return -ENOMEM;
1683
1684 ret = eth_prepare_mac_addr_change(dev, addr);
1685 if (ret)
1686 goto out;
1687
1688 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1689 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1690 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1691 VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1692 dev_warn(&vdev->dev,
1693 "Failed to set mac address by vq command.\n");
1694 ret = -EINVAL;
1695 goto out;
1696 }
1697 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1698 !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1699 unsigned int i;
1700
1701 /* Naturally, this has an atomicity problem. */
1702 for (i = 0; i < dev->addr_len; i++)
1703 virtio_cwrite8(vdev,
1704 offsetof(struct virtio_net_config, mac) +
1705 i, addr->sa_data[i]);
1706 }
1707
1708 eth_commit_mac_addr_change(dev, p);
1709 ret = 0;
1710
1711out:
1712 kfree(addr);
1713 return ret;
1714}
1715
1716static void virtnet_stats(struct net_device *dev,
1717 struct rtnl_link_stats64 *tot)
1718{
1719 struct virtnet_info *vi = netdev_priv(dev);
1720 unsigned int start;
1721 int i;
1722
1723 for (i = 0; i < vi->max_queue_pairs; i++) {
1724 u64 tpackets, tbytes, rpackets, rbytes, rdrops;
1725 struct receive_queue *rq = &vi->rq[i];
1726 struct send_queue *sq = &vi->sq[i];
1727
1728 do {
1729 start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1730 tpackets = sq->stats.packets;
1731 tbytes = sq->stats.bytes;
1732 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1733
1734 do {
1735 start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1736 rpackets = rq->stats.packets;
1737 rbytes = rq->stats.bytes;
1738 rdrops = rq->stats.drops;
1739 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1740
1741 tot->rx_packets += rpackets;
1742 tot->tx_packets += tpackets;
1743 tot->rx_bytes += rbytes;
1744 tot->tx_bytes += tbytes;
1745 tot->rx_dropped += rdrops;
1746 }
1747
1748 tot->tx_dropped = dev->stats.tx_dropped;
1749 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1750 tot->rx_length_errors = dev->stats.rx_length_errors;
1751 tot->rx_frame_errors = dev->stats.rx_frame_errors;
1752}
1753
1754static void virtnet_ack_link_announce(struct virtnet_info *vi)
1755{
1756 rtnl_lock();
1757 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1758 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1759 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1760 rtnl_unlock();
1761}
1762
1763static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1764{
1765 struct scatterlist sg;
1766 struct net_device *dev = vi->dev;
1767
1768 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1769 return 0;
1770
1771 vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1772 sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
1773
1774 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1775 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1776 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1777 queue_pairs);
1778 return -EINVAL;
1779 } else {
1780 vi->curr_queue_pairs = queue_pairs;
1781 /* virtnet_open() will refill when device is going to up. */
1782 if (dev->flags & IFF_UP)
1783 schedule_delayed_work(&vi->refill, 0);
1784 }
1785
1786 return 0;
1787}
1788
1789static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1790{
1791 int err;
1792
1793 rtnl_lock();
1794 err = _virtnet_set_queues(vi, queue_pairs);
1795 rtnl_unlock();
1796 return err;
1797}
1798
1799static int virtnet_close(struct net_device *dev)
1800{
1801 struct virtnet_info *vi = netdev_priv(dev);
1802 int i;
1803
1804 /* Make sure refill_work doesn't re-enable napi! */
1805 cancel_delayed_work_sync(&vi->refill);
1806
1807 for (i = 0; i < vi->max_queue_pairs; i++) {
1808 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1809 napi_disable(&vi->rq[i].napi);
1810 virtnet_napi_tx_disable(&vi->sq[i].napi);
1811 }
1812
1813 return 0;
1814}
1815
1816static void virtnet_set_rx_mode(struct net_device *dev)
1817{
1818 struct virtnet_info *vi = netdev_priv(dev);
1819 struct scatterlist sg[2];
1820 struct virtio_net_ctrl_mac *mac_data;
1821 struct netdev_hw_addr *ha;
1822 int uc_count;
1823 int mc_count;
1824 void *buf;
1825 int i;
1826
1827 /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1828 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1829 return;
1830
1831 vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
1832 vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1833
1834 sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
1835
1836 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1837 VIRTIO_NET_CTRL_RX_PROMISC, sg))
1838 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1839 vi->ctrl->promisc ? "en" : "dis");
1840
1841 sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
1842
1843 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1844 VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1845 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1846 vi->ctrl->allmulti ? "en" : "dis");
1847
1848 uc_count = netdev_uc_count(dev);
1849 mc_count = netdev_mc_count(dev);
1850 /* MAC filter - use one buffer for both lists */
1851 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1852 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1853 mac_data = buf;
1854 if (!buf)
1855 return;
1856
1857 sg_init_table(sg, 2);
1858
1859 /* Store the unicast list and count in the front of the buffer */
1860 mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1861 i = 0;
1862 netdev_for_each_uc_addr(ha, dev)
1863 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1864
1865 sg_set_buf(&sg[0], mac_data,
1866 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1867
1868 /* multicast list and count fill the end */
1869 mac_data = (void *)&mac_data->macs[uc_count][0];
1870
1871 mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1872 i = 0;
1873 netdev_for_each_mc_addr(ha, dev)
1874 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1875
1876 sg_set_buf(&sg[1], mac_data,
1877 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1878
1879 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1880 VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1881 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1882
1883 kfree(buf);
1884}
1885
1886static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1887 __be16 proto, u16 vid)
1888{
1889 struct virtnet_info *vi = netdev_priv(dev);
1890 struct scatterlist sg;
1891
1892 vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1893 sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1894
1895 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1896 VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1897 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1898 return 0;
1899}
1900
1901static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1902 __be16 proto, u16 vid)
1903{
1904 struct virtnet_info *vi = netdev_priv(dev);
1905 struct scatterlist sg;
1906
1907 vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1908 sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1909
1910 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1911 VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1912 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1913 return 0;
1914}
1915
1916static void virtnet_clean_affinity(struct virtnet_info *vi)
1917{
1918 int i;
1919
1920 if (vi->affinity_hint_set) {
1921 for (i = 0; i < vi->max_queue_pairs; i++) {
1922 virtqueue_set_affinity(vi->rq[i].vq, NULL);
1923 virtqueue_set_affinity(vi->sq[i].vq, NULL);
1924 }
1925
1926 vi->affinity_hint_set = false;
1927 }
1928}
1929
1930static void virtnet_set_affinity(struct virtnet_info *vi)
1931{
1932 cpumask_var_t mask;
1933 int stragglers;
1934 int group_size;
1935 int i, j, cpu;
1936 int num_cpu;
1937 int stride;
1938
1939 if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
1940 virtnet_clean_affinity(vi);
1941 return;
1942 }
1943
1944 num_cpu = num_online_cpus();
1945 stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
1946 stragglers = num_cpu >= vi->curr_queue_pairs ?
1947 num_cpu % vi->curr_queue_pairs :
1948 0;
1949 cpu = cpumask_next(-1, cpu_online_mask);
1950
1951 for (i = 0; i < vi->curr_queue_pairs; i++) {
1952 group_size = stride + (i < stragglers ? 1 : 0);
1953
1954 for (j = 0; j < group_size; j++) {
1955 cpumask_set_cpu(cpu, mask);
1956 cpu = cpumask_next_wrap(cpu, cpu_online_mask,
1957 nr_cpu_ids, false);
1958 }
1959 virtqueue_set_affinity(vi->rq[i].vq, mask);
1960 virtqueue_set_affinity(vi->sq[i].vq, mask);
1961 __netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, false);
1962 cpumask_clear(mask);
1963 }
1964
1965 vi->affinity_hint_set = true;
1966 free_cpumask_var(mask);
1967}
1968
1969static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1970{
1971 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1972 node);
1973 virtnet_set_affinity(vi);
1974 return 0;
1975}
1976
1977static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1978{
1979 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1980 node_dead);
1981 virtnet_set_affinity(vi);
1982 return 0;
1983}
1984
1985static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1986{
1987 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1988 node);
1989
1990 virtnet_clean_affinity(vi);
1991 return 0;
1992}
1993
1994static enum cpuhp_state virtionet_online;
1995
1996static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1997{
1998 int ret;
1999
2000 ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2001 if (ret)
2002 return ret;
2003 ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2004 &vi->node_dead);
2005 if (!ret)
2006 return ret;
2007 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2008 return ret;
2009}
2010
2011static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2012{
2013 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2014 cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2015 &vi->node_dead);
2016}
2017
2018static void virtnet_get_ringparam(struct net_device *dev,
2019 struct ethtool_ringparam *ring)
2020{
2021 struct virtnet_info *vi = netdev_priv(dev);
2022
2023 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2024 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2025 ring->rx_pending = ring->rx_max_pending;
2026 ring->tx_pending = ring->tx_max_pending;
2027}
2028
2029
2030static void virtnet_get_drvinfo(struct net_device *dev,
2031 struct ethtool_drvinfo *info)
2032{
2033 struct virtnet_info *vi = netdev_priv(dev);
2034 struct virtio_device *vdev = vi->vdev;
2035
2036 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2037 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2038 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2039
2040}
2041
2042/* TODO: Eliminate OOO packets during switching */
2043static int virtnet_set_channels(struct net_device *dev,
2044 struct ethtool_channels *channels)
2045{
2046 struct virtnet_info *vi = netdev_priv(dev);
2047 u16 queue_pairs = channels->combined_count;
2048 int err;
2049
2050 /* We don't support separate rx/tx channels.
2051 * We don't allow setting 'other' channels.
2052 */
2053 if (channels->rx_count || channels->tx_count || channels->other_count)
2054 return -EINVAL;
2055
2056 if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2057 return -EINVAL;
2058
2059 /* For now we don't support modifying channels while XDP is loaded
2060 * also when XDP is loaded all RX queues have XDP programs so we only
2061 * need to check a single RX queue.
2062 */
2063 if (vi->rq[0].xdp_prog)
2064 return -EINVAL;
2065
2066 get_online_cpus();
2067 err = _virtnet_set_queues(vi, queue_pairs);
2068 if (!err) {
2069 netif_set_real_num_tx_queues(dev, queue_pairs);
2070 netif_set_real_num_rx_queues(dev, queue_pairs);
2071
2072 virtnet_set_affinity(vi);
2073 }
2074 put_online_cpus();
2075
2076 return err;
2077}
2078
2079static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2080{
2081 struct virtnet_info *vi = netdev_priv(dev);
2082 char *p = (char *)data;
2083 unsigned int i, j;
2084
2085 switch (stringset) {
2086 case ETH_SS_STATS:
2087 for (i = 0; i < vi->curr_queue_pairs; i++) {
2088 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2089 snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
2090 i, virtnet_rq_stats_desc[j].desc);
2091 p += ETH_GSTRING_LEN;
2092 }
2093 }
2094
2095 for (i = 0; i < vi->curr_queue_pairs; i++) {
2096 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2097 snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
2098 i, virtnet_sq_stats_desc[j].desc);
2099 p += ETH_GSTRING_LEN;
2100 }
2101 }
2102 break;
2103 }
2104}
2105
2106static int virtnet_get_sset_count(struct net_device *dev, int sset)
2107{
2108 struct virtnet_info *vi = netdev_priv(dev);
2109
2110 switch (sset) {
2111 case ETH_SS_STATS:
2112 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2113 VIRTNET_SQ_STATS_LEN);
2114 default:
2115 return -EOPNOTSUPP;
2116 }
2117}
2118
2119static void virtnet_get_ethtool_stats(struct net_device *dev,
2120 struct ethtool_stats *stats, u64 *data)
2121{
2122 struct virtnet_info *vi = netdev_priv(dev);
2123 unsigned int idx = 0, start, i, j;
2124 const u8 *stats_base;
2125 size_t offset;
2126
2127 for (i = 0; i < vi->curr_queue_pairs; i++) {
2128 struct receive_queue *rq = &vi->rq[i];
2129
2130 stats_base = (u8 *)&rq->stats;
2131 do {
2132 start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
2133 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2134 offset = virtnet_rq_stats_desc[j].offset;
2135 data[idx + j] = *(u64 *)(stats_base + offset);
2136 }
2137 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
2138 idx += VIRTNET_RQ_STATS_LEN;
2139 }
2140
2141 for (i = 0; i < vi->curr_queue_pairs; i++) {
2142 struct send_queue *sq = &vi->sq[i];
2143
2144 stats_base = (u8 *)&sq->stats;
2145 do {
2146 start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
2147 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2148 offset = virtnet_sq_stats_desc[j].offset;
2149 data[idx + j] = *(u64 *)(stats_base + offset);
2150 }
2151 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
2152 idx += VIRTNET_SQ_STATS_LEN;
2153 }
2154}
2155
2156static void virtnet_get_channels(struct net_device *dev,
2157 struct ethtool_channels *channels)
2158{
2159 struct virtnet_info *vi = netdev_priv(dev);
2160
2161 channels->combined_count = vi->curr_queue_pairs;
2162 channels->max_combined = vi->max_queue_pairs;
2163 channels->max_other = 0;
2164 channels->rx_count = 0;
2165 channels->tx_count = 0;
2166 channels->other_count = 0;
2167}
2168
2169/* Check if the user is trying to change anything besides speed/duplex */
2170static bool
2171virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
2172{
2173 struct ethtool_link_ksettings diff1 = *cmd;
2174 struct ethtool_link_ksettings diff2 = {};
2175
2176 /* cmd is always set so we need to clear it, validate the port type
2177 * and also without autonegotiation we can ignore advertising
2178 */
2179 diff1.base.speed = 0;
2180 diff2.base.port = PORT_OTHER;
2181 ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
2182 diff1.base.duplex = 0;
2183 diff1.base.cmd = 0;
2184 diff1.base.link_mode_masks_nwords = 0;
2185
2186 return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
2187 bitmap_empty(diff1.link_modes.supported,
2188 __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2189 bitmap_empty(diff1.link_modes.advertising,
2190 __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2191 bitmap_empty(diff1.link_modes.lp_advertising,
2192 __ETHTOOL_LINK_MODE_MASK_NBITS);
2193}
2194
2195static int virtnet_set_link_ksettings(struct net_device *dev,
2196 const struct ethtool_link_ksettings *cmd)
2197{
2198 struct virtnet_info *vi = netdev_priv(dev);
2199 u32 speed;
2200
2201 speed = cmd->base.speed;
2202 /* don't allow custom speed and duplex */
2203 if (!ethtool_validate_speed(speed) ||
2204 !ethtool_validate_duplex(cmd->base.duplex) ||
2205 !virtnet_validate_ethtool_cmd(cmd))
2206 return -EINVAL;
2207 vi->speed = speed;
2208 vi->duplex = cmd->base.duplex;
2209
2210 return 0;
2211}
2212
2213static int virtnet_get_link_ksettings(struct net_device *dev,
2214 struct ethtool_link_ksettings *cmd)
2215{
2216 struct virtnet_info *vi = netdev_priv(dev);
2217
2218 cmd->base.speed = vi->speed;
2219 cmd->base.duplex = vi->duplex;
2220 cmd->base.port = PORT_OTHER;
2221
2222 return 0;
2223}
2224
2225static int virtnet_set_coalesce(struct net_device *dev,
2226 struct ethtool_coalesce *ec)
2227{
2228 struct ethtool_coalesce ec_default = {
2229 .cmd = ETHTOOL_SCOALESCE,
2230 .rx_max_coalesced_frames = 1,
2231 };
2232 struct virtnet_info *vi = netdev_priv(dev);
2233 int i, napi_weight;
2234
2235 if (ec->tx_max_coalesced_frames > 1)
2236 return -EINVAL;
2237
2238 ec_default.tx_max_coalesced_frames = ec->tx_max_coalesced_frames;
2239 napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2240
2241 /* disallow changes to fields not explicitly tested above */
2242 if (memcmp(ec, &ec_default, sizeof(ec_default)))
2243 return -EINVAL;
2244
2245 if (napi_weight ^ vi->sq[0].napi.weight) {
2246 if (dev->flags & IFF_UP)
2247 return -EBUSY;
2248 for (i = 0; i < vi->max_queue_pairs; i++)
2249 vi->sq[i].napi.weight = napi_weight;
2250 }
2251
2252 return 0;
2253}
2254
2255static int virtnet_get_coalesce(struct net_device *dev,
2256 struct ethtool_coalesce *ec)
2257{
2258 struct ethtool_coalesce ec_default = {
2259 .cmd = ETHTOOL_GCOALESCE,
2260 .rx_max_coalesced_frames = 1,
2261 };
2262 struct virtnet_info *vi = netdev_priv(dev);
2263
2264 memcpy(ec, &ec_default, sizeof(ec_default));
2265
2266 if (vi->sq[0].napi.weight)
2267 ec->tx_max_coalesced_frames = 1;
2268
2269 return 0;
2270}
2271
2272static void virtnet_init_settings(struct net_device *dev)
2273{
2274 struct virtnet_info *vi = netdev_priv(dev);
2275
2276 vi->speed = SPEED_UNKNOWN;
2277 vi->duplex = DUPLEX_UNKNOWN;
2278}
2279
2280static void virtnet_update_settings(struct virtnet_info *vi)
2281{
2282 u32 speed;
2283 u8 duplex;
2284
2285 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2286 return;
2287
2288 speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
2289 speed));
2290 if (ethtool_validate_speed(speed))
2291 vi->speed = speed;
2292 duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
2293 duplex));
2294 if (ethtool_validate_duplex(duplex))
2295 vi->duplex = duplex;
2296}
2297
2298static const struct ethtool_ops virtnet_ethtool_ops = {
2299 .get_drvinfo = virtnet_get_drvinfo,
2300 .get_link = ethtool_op_get_link,
2301 .get_ringparam = virtnet_get_ringparam,
2302 .get_strings = virtnet_get_strings,
2303 .get_sset_count = virtnet_get_sset_count,
2304 .get_ethtool_stats = virtnet_get_ethtool_stats,
2305 .set_channels = virtnet_set_channels,
2306 .get_channels = virtnet_get_channels,
2307 .get_ts_info = ethtool_op_get_ts_info,
2308 .get_link_ksettings = virtnet_get_link_ksettings,
2309 .set_link_ksettings = virtnet_set_link_ksettings,
2310 .set_coalesce = virtnet_set_coalesce,
2311 .get_coalesce = virtnet_get_coalesce,
2312};
2313
2314static void virtnet_freeze_down(struct virtio_device *vdev)
2315{
2316 struct virtnet_info *vi = vdev->priv;
2317 int i;
2318
2319 /* Make sure no work handler is accessing the device */
2320 flush_work(&vi->config_work);
2321
2322 netif_tx_lock_bh(vi->dev);
2323 netif_device_detach(vi->dev);
2324 netif_tx_unlock_bh(vi->dev);
2325 cancel_delayed_work_sync(&vi->refill);
2326
2327 if (netif_running(vi->dev)) {
2328 for (i = 0; i < vi->max_queue_pairs; i++) {
2329 napi_disable(&vi->rq[i].napi);
2330 virtnet_napi_tx_disable(&vi->sq[i].napi);
2331 }
2332 }
2333}
2334
2335static int init_vqs(struct virtnet_info *vi);
2336
2337static int virtnet_restore_up(struct virtio_device *vdev)
2338{
2339 struct virtnet_info *vi = vdev->priv;
2340 int err, i;
2341
2342 err = init_vqs(vi);
2343 if (err)
2344 return err;
2345
2346 virtio_device_ready(vdev);
2347
2348 if (netif_running(vi->dev)) {
2349 for (i = 0; i < vi->curr_queue_pairs; i++)
2350 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2351 schedule_delayed_work(&vi->refill, 0);
2352
2353 for (i = 0; i < vi->max_queue_pairs; i++) {
2354 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2355 virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2356 &vi->sq[i].napi);
2357 }
2358 }
2359
2360 netif_tx_lock_bh(vi->dev);
2361 netif_device_attach(vi->dev);
2362 netif_tx_unlock_bh(vi->dev);
2363 return err;
2364}
2365
2366static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2367{
2368 struct scatterlist sg;
2369 vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
2370
2371 sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
2372
2373 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2374 VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2375 dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
2376 return -EINVAL;
2377 }
2378
2379 return 0;
2380}
2381
2382static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2383{
2384 u64 offloads = 0;
2385
2386 if (!vi->guest_offloads)
2387 return 0;
2388
2389 return virtnet_set_guest_offloads(vi, offloads);
2390}
2391
2392static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2393{
2394 u64 offloads = vi->guest_offloads;
2395
2396 if (!vi->guest_offloads)
2397 return 0;
2398
2399 return virtnet_set_guest_offloads(vi, offloads);
2400}
2401
2402static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2403 struct netlink_ext_ack *extack)
2404{
2405 unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2406 struct virtnet_info *vi = netdev_priv(dev);
2407 struct bpf_prog *old_prog;
2408 u16 xdp_qp = 0, curr_qp;
2409 int i, err;
2410
2411 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2412 && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2413 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2414 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2415 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
2416 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
2417 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO/CSUM, disable LRO/CSUM first");
2418 return -EOPNOTSUPP;
2419 }
2420
2421 if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2422 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2423 return -EINVAL;
2424 }
2425
2426 if (dev->mtu > max_sz) {
2427 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2428 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2429 return -EINVAL;
2430 }
2431
2432 curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2433 if (prog)
2434 xdp_qp = nr_cpu_ids;
2435
2436 /* XDP requires extra queues for XDP_TX */
2437 if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2438 NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
2439 netdev_warn(dev, "request %i queues but max is %i\n",
2440 curr_qp + xdp_qp, vi->max_queue_pairs);
2441 return -ENOMEM;
2442 }
2443
2444 old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
2445 if (!prog && !old_prog)
2446 return 0;
2447
2448 if (prog) {
2449 prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
2450 if (IS_ERR(prog))
2451 return PTR_ERR(prog);
2452 }
2453
2454 /* Make sure NAPI is not using any XDP TX queues for RX. */
2455 if (netif_running(dev)) {
2456 for (i = 0; i < vi->max_queue_pairs; i++) {
2457 napi_disable(&vi->rq[i].napi);
2458 virtnet_napi_tx_disable(&vi->sq[i].napi);
2459 }
2460 }
2461
2462 if (!prog) {
2463 for (i = 0; i < vi->max_queue_pairs; i++) {
2464 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2465 if (i == 0)
2466 virtnet_restore_guest_offloads(vi);
2467 }
2468 synchronize_net();
2469 }
2470
2471 err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2472 if (err)
2473 goto err;
2474 netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2475 vi->xdp_queue_pairs = xdp_qp;
2476
2477 if (prog) {
2478 for (i = 0; i < vi->max_queue_pairs; i++) {
2479 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2480 if (i == 0 && !old_prog)
2481 virtnet_clear_guest_offloads(vi);
2482 }
2483 }
2484
2485 for (i = 0; i < vi->max_queue_pairs; i++) {
2486 if (old_prog)
2487 bpf_prog_put(old_prog);
2488 if (netif_running(dev)) {
2489 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2490 virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2491 &vi->sq[i].napi);
2492 }
2493 }
2494
2495 return 0;
2496
2497err:
2498 if (!prog) {
2499 virtnet_clear_guest_offloads(vi);
2500 for (i = 0; i < vi->max_queue_pairs; i++)
2501 rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
2502 }
2503
2504 if (netif_running(dev)) {
2505 for (i = 0; i < vi->max_queue_pairs; i++) {
2506 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2507 virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2508 &vi->sq[i].napi);
2509 }
2510 }
2511 if (prog)
2512 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2513 return err;
2514}
2515
2516static u32 virtnet_xdp_query(struct net_device *dev)
2517{
2518 struct virtnet_info *vi = netdev_priv(dev);
2519 const struct bpf_prog *xdp_prog;
2520 int i;
2521
2522 for (i = 0; i < vi->max_queue_pairs; i++) {
2523 xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2524 if (xdp_prog)
2525 return xdp_prog->aux->id;
2526 }
2527 return 0;
2528}
2529
2530static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2531{
2532 switch (xdp->command) {
2533 case XDP_SETUP_PROG:
2534 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2535 case XDP_QUERY_PROG:
2536 xdp->prog_id = virtnet_xdp_query(dev);
2537 return 0;
2538 default:
2539 return -EINVAL;
2540 }
2541}
2542
2543static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
2544 size_t len)
2545{
2546 struct virtnet_info *vi = netdev_priv(dev);
2547 int ret;
2548
2549 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2550 return -EOPNOTSUPP;
2551
2552 ret = snprintf(buf, len, "sby");
2553 if (ret >= len)
2554 return -EOPNOTSUPP;
2555
2556 return 0;
2557}
2558
2559static int virtnet_set_features(struct net_device *dev,
2560 netdev_features_t features)
2561{
2562 struct virtnet_info *vi = netdev_priv(dev);
2563 u64 offloads;
2564 int err;
2565
2566 if ((dev->features ^ features) & NETIF_F_LRO) {
2567 if (vi->xdp_queue_pairs)
2568 return -EBUSY;
2569
2570 if (features & NETIF_F_LRO)
2571 offloads = vi->guest_offloads_capable;
2572 else
2573 offloads = 0;
2574
2575 err = virtnet_set_guest_offloads(vi, offloads);
2576 if (err)
2577 return err;
2578 vi->guest_offloads = offloads;
2579 }
2580
2581 return 0;
2582}
2583
2584static const struct net_device_ops virtnet_netdev = {
2585 .ndo_open = virtnet_open,
2586 .ndo_stop = virtnet_close,
2587 .ndo_start_xmit = start_xmit,
2588 .ndo_validate_addr = eth_validate_addr,
2589 .ndo_set_mac_address = virtnet_set_mac_address,
2590 .ndo_set_rx_mode = virtnet_set_rx_mode,
2591 .ndo_get_stats64 = virtnet_stats,
2592 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2593 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2594 .ndo_bpf = virtnet_xdp,
2595 .ndo_xdp_xmit = virtnet_xdp_xmit,
2596 .ndo_features_check = passthru_features_check,
2597 .ndo_get_phys_port_name = virtnet_get_phys_port_name,
2598 .ndo_set_features = virtnet_set_features,
2599};
2600
2601static void virtnet_config_changed_work(struct work_struct *work)
2602{
2603 struct virtnet_info *vi =
2604 container_of(work, struct virtnet_info, config_work);
2605 u16 v;
2606
2607 if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2608 struct virtio_net_config, status, &v) < 0)
2609 return;
2610
2611 if (v & VIRTIO_NET_S_ANNOUNCE) {
2612 netdev_notify_peers(vi->dev);
2613 virtnet_ack_link_announce(vi);
2614 }
2615
2616 /* Ignore unknown (future) status bits */
2617 v &= VIRTIO_NET_S_LINK_UP;
2618
2619 if (vi->status == v)
2620 return;
2621
2622 vi->status = v;
2623
2624 if (vi->status & VIRTIO_NET_S_LINK_UP) {
2625 virtnet_update_settings(vi);
2626 netif_carrier_on(vi->dev);
2627 netif_tx_wake_all_queues(vi->dev);
2628 } else {
2629 netif_carrier_off(vi->dev);
2630 netif_tx_stop_all_queues(vi->dev);
2631 }
2632}
2633
2634static void virtnet_config_changed(struct virtio_device *vdev)
2635{
2636 struct virtnet_info *vi = vdev->priv;
2637
2638 schedule_work(&vi->config_work);
2639}
2640
2641static void virtnet_free_queues(struct virtnet_info *vi)
2642{
2643 int i;
2644
2645 for (i = 0; i < vi->max_queue_pairs; i++) {
2646 napi_hash_del(&vi->rq[i].napi);
2647 netif_napi_del(&vi->rq[i].napi);
2648 netif_napi_del(&vi->sq[i].napi);
2649 }
2650
2651 /* We called napi_hash_del() before netif_napi_del(),
2652 * we need to respect an RCU grace period before freeing vi->rq
2653 */
2654 synchronize_net();
2655
2656 kfree(vi->rq);
2657 kfree(vi->sq);
2658 kfree(vi->ctrl);
2659}
2660
2661static void _free_receive_bufs(struct virtnet_info *vi)
2662{
2663 struct bpf_prog *old_prog;
2664 int i;
2665
2666 for (i = 0; i < vi->max_queue_pairs; i++) {
2667 while (vi->rq[i].pages)
2668 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2669
2670 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2671 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2672 if (old_prog)
2673 bpf_prog_put(old_prog);
2674 }
2675}
2676
2677static void free_receive_bufs(struct virtnet_info *vi)
2678{
2679 rtnl_lock();
2680 _free_receive_bufs(vi);
2681 rtnl_unlock();
2682}
2683
2684static void free_receive_page_frags(struct virtnet_info *vi)
2685{
2686 int i;
2687 for (i = 0; i < vi->max_queue_pairs; i++)
2688 if (vi->rq[i].alloc_frag.page)
2689 put_page(vi->rq[i].alloc_frag.page);
2690}
2691
2692static void free_unused_bufs(struct virtnet_info *vi)
2693{
2694 void *buf;
2695 int i;
2696
2697 for (i = 0; i < vi->max_queue_pairs; i++) {
2698 struct virtqueue *vq = vi->sq[i].vq;
2699 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2700 if (!is_xdp_frame(buf))
2701 dev_kfree_skb(buf);
2702 else
2703 xdp_return_frame(ptr_to_xdp(buf));
2704 }
2705 }
2706
2707 for (i = 0; i < vi->max_queue_pairs; i++) {
2708 struct virtqueue *vq = vi->rq[i].vq;
2709
2710 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2711 if (vi->mergeable_rx_bufs) {
2712 put_page(virt_to_head_page(buf));
2713 } else if (vi->big_packets) {
2714 give_pages(&vi->rq[i], buf);
2715 } else {
2716 put_page(virt_to_head_page(buf));
2717 }
2718 }
2719 }
2720}
2721
2722static void virtnet_del_vqs(struct virtnet_info *vi)
2723{
2724 struct virtio_device *vdev = vi->vdev;
2725
2726 virtnet_clean_affinity(vi);
2727
2728 vdev->config->del_vqs(vdev);
2729
2730 virtnet_free_queues(vi);
2731}
2732
2733/* How large should a single buffer be so a queue full of these can fit at
2734 * least one full packet?
2735 * Logic below assumes the mergeable buffer header is used.
2736 */
2737static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2738{
2739 const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2740 unsigned int rq_size = virtqueue_get_vring_size(vq);
2741 unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2742 unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2743 unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2744
2745 return max(max(min_buf_len, hdr_len) - hdr_len,
2746 (unsigned int)GOOD_PACKET_LEN);
2747}
2748
2749static int virtnet_find_vqs(struct virtnet_info *vi)
2750{
2751 vq_callback_t **callbacks;
2752 struct virtqueue **vqs;
2753 int ret = -ENOMEM;
2754 int i, total_vqs;
2755 const char **names;
2756 bool *ctx;
2757
2758 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2759 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2760 * possible control vq.
2761 */
2762 total_vqs = vi->max_queue_pairs * 2 +
2763 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2764
2765 /* Allocate space for find_vqs parameters */
2766 vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
2767 if (!vqs)
2768 goto err_vq;
2769 callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
2770 if (!callbacks)
2771 goto err_callback;
2772 names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
2773 if (!names)
2774 goto err_names;
2775 if (!vi->big_packets || vi->mergeable_rx_bufs) {
2776 ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
2777 if (!ctx)
2778 goto err_ctx;
2779 } else {
2780 ctx = NULL;
2781 }
2782
2783 /* Parameters for control virtqueue, if any */
2784 if (vi->has_cvq) {
2785 callbacks[total_vqs - 1] = NULL;
2786 names[total_vqs - 1] = "control";
2787 }
2788
2789 /* Allocate/initialize parameters for send/receive virtqueues */
2790 for (i = 0; i < vi->max_queue_pairs; i++) {
2791 callbacks[rxq2vq(i)] = skb_recv_done;
2792 callbacks[txq2vq(i)] = skb_xmit_done;
2793 sprintf(vi->rq[i].name, "input.%d", i);
2794 sprintf(vi->sq[i].name, "output.%d", i);
2795 names[rxq2vq(i)] = vi->rq[i].name;
2796 names[txq2vq(i)] = vi->sq[i].name;
2797 if (ctx)
2798 ctx[rxq2vq(i)] = true;
2799 }
2800
2801 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2802 names, ctx, NULL);
2803 if (ret)
2804 goto err_find;
2805
2806 if (vi->has_cvq) {
2807 vi->cvq = vqs[total_vqs - 1];
2808 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2809 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2810 }
2811
2812 for (i = 0; i < vi->max_queue_pairs; i++) {
2813 vi->rq[i].vq = vqs[rxq2vq(i)];
2814 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2815 vi->sq[i].vq = vqs[txq2vq(i)];
2816 }
2817
2818 /* run here: ret == 0. */
2819
2820
2821err_find:
2822 kfree(ctx);
2823err_ctx:
2824 kfree(names);
2825err_names:
2826 kfree(callbacks);
2827err_callback:
2828 kfree(vqs);
2829err_vq:
2830 return ret;
2831}
2832
2833static int virtnet_alloc_queues(struct virtnet_info *vi)
2834{
2835 int i;
2836
2837 vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
2838 if (!vi->ctrl)
2839 goto err_ctrl;
2840 vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
2841 if (!vi->sq)
2842 goto err_sq;
2843 vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
2844 if (!vi->rq)
2845 goto err_rq;
2846
2847 INIT_DELAYED_WORK(&vi->refill, refill_work);
2848 for (i = 0; i < vi->max_queue_pairs; i++) {
2849 vi->rq[i].pages = NULL;
2850 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2851 napi_weight);
2852 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2853 napi_tx ? napi_weight : 0);
2854
2855 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2856 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2857 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2858
2859 u64_stats_init(&vi->rq[i].stats.syncp);
2860 u64_stats_init(&vi->sq[i].stats.syncp);
2861 }
2862
2863 return 0;
2864
2865err_rq:
2866 kfree(vi->sq);
2867err_sq:
2868 kfree(vi->ctrl);
2869err_ctrl:
2870 return -ENOMEM;
2871}
2872
2873static int init_vqs(struct virtnet_info *vi)
2874{
2875 int ret;
2876
2877 /* Allocate send & receive queues */
2878 ret = virtnet_alloc_queues(vi);
2879 if (ret)
2880 goto err;
2881
2882 ret = virtnet_find_vqs(vi);
2883 if (ret)
2884 goto err_free;
2885
2886 get_online_cpus();
2887 virtnet_set_affinity(vi);
2888 put_online_cpus();
2889
2890 return 0;
2891
2892err_free:
2893 virtnet_free_queues(vi);
2894err:
2895 return ret;
2896}
2897
2898#ifdef CONFIG_SYSFS
2899static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2900 char *buf)
2901{
2902 struct virtnet_info *vi = netdev_priv(queue->dev);
2903 unsigned int queue_index = get_netdev_rx_queue_index(queue);
2904 unsigned int headroom = virtnet_get_headroom(vi);
2905 unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
2906 struct ewma_pkt_len *avg;
2907
2908 BUG_ON(queue_index >= vi->max_queue_pairs);
2909 avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2910 return sprintf(buf, "%u\n",
2911 get_mergeable_buf_len(&vi->rq[queue_index], avg,
2912 SKB_DATA_ALIGN(headroom + tailroom)));
2913}
2914
2915static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2916 __ATTR_RO(mergeable_rx_buffer_size);
2917
2918static struct attribute *virtio_net_mrg_rx_attrs[] = {
2919 &mergeable_rx_buffer_size_attribute.attr,
2920 NULL
2921};
2922
2923static const struct attribute_group virtio_net_mrg_rx_group = {
2924 .name = "virtio_net",
2925 .attrs = virtio_net_mrg_rx_attrs
2926};
2927#endif
2928
2929static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2930 unsigned int fbit,
2931 const char *fname, const char *dname)
2932{
2933 if (!virtio_has_feature(vdev, fbit))
2934 return false;
2935
2936 dev_err(&vdev->dev, "device advertises feature %s but not %s",
2937 fname, dname);
2938
2939 return true;
2940}
2941
2942#define VIRTNET_FAIL_ON(vdev, fbit, dbit) \
2943 virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2944
2945static bool virtnet_validate_features(struct virtio_device *vdev)
2946{
2947 if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2948 (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2949 "VIRTIO_NET_F_CTRL_VQ") ||
2950 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2951 "VIRTIO_NET_F_CTRL_VQ") ||
2952 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2953 "VIRTIO_NET_F_CTRL_VQ") ||
2954 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2955 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2956 "VIRTIO_NET_F_CTRL_VQ"))) {
2957 return false;
2958 }
2959
2960 return true;
2961}
2962
2963#define MIN_MTU ETH_MIN_MTU
2964#define MAX_MTU ETH_MAX_MTU
2965
2966static int virtnet_validate(struct virtio_device *vdev)
2967{
2968 if (!vdev->config->get) {
2969 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2970 __func__);
2971 return -EINVAL;
2972 }
2973
2974 if (!virtnet_validate_features(vdev))
2975 return -EINVAL;
2976
2977 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2978 int mtu = virtio_cread16(vdev,
2979 offsetof(struct virtio_net_config,
2980 mtu));
2981 if (mtu < MIN_MTU)
2982 __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2983 }
2984
2985 return 0;
2986}
2987
2988static int virtnet_probe(struct virtio_device *vdev)
2989{
2990 int i, err = -ENOMEM;
2991 struct net_device *dev;
2992 struct virtnet_info *vi;
2993 u16 max_queue_pairs;
2994 int mtu;
2995
2996 /* Find if host supports multiqueue virtio_net device */
2997 err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2998 struct virtio_net_config,
2999 max_virtqueue_pairs, &max_queue_pairs);
3000
3001 /* We need at least 2 queue's */
3002 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
3003 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
3004 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3005 max_queue_pairs = 1;
3006
3007 /* Allocate ourselves a network device with room for our info */
3008 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
3009 if (!dev)
3010 return -ENOMEM;
3011
3012 /* Set up network device as normal. */
3013 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
3014 dev->netdev_ops = &virtnet_netdev;
3015 dev->features = NETIF_F_HIGHDMA;
3016
3017 dev->ethtool_ops = &virtnet_ethtool_ops;
3018 SET_NETDEV_DEV(dev, &vdev->dev);
3019
3020 /* Do we support "hardware" checksums? */
3021 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
3022 /* This opens up the world of extra features. */
3023 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3024 if (csum)
3025 dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3026
3027 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
3028 dev->hw_features |= NETIF_F_TSO
3029 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
3030 }
3031 /* Individual feature bits: what can host handle? */
3032 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
3033 dev->hw_features |= NETIF_F_TSO;
3034 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3035 dev->hw_features |= NETIF_F_TSO6;
3036 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3037 dev->hw_features |= NETIF_F_TSO_ECN;
3038
3039 dev->features |= NETIF_F_GSO_ROBUST;
3040
3041 if (gso)
3042 dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3043 /* (!csum && gso) case will be fixed by register_netdev() */
3044 }
3045 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3046 dev->features |= NETIF_F_RXCSUM;
3047 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3048 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3049 dev->features |= NETIF_F_LRO;
3050 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3051 dev->hw_features |= NETIF_F_LRO;
3052
3053 dev->vlan_features = dev->features;
3054
3055 /* MTU range: 68 - 65535 */
3056 dev->min_mtu = MIN_MTU;
3057 dev->max_mtu = MAX_MTU;
3058
3059 /* Configuration may specify what MAC to use. Otherwise random. */
3060 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
3061 virtio_cread_bytes(vdev,
3062 offsetof(struct virtio_net_config, mac),
3063 dev->dev_addr, dev->addr_len);
3064 else
3065 eth_hw_addr_random(dev);
3066
3067 /* Set up our device-specific information */
3068 vi = netdev_priv(dev);
3069 vi->dev = dev;
3070 vi->vdev = vdev;
3071 vdev->priv = vi;
3072
3073 INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3074
3075 /* If we can receive ANY GSO packets, we must allocate large ones. */
3076 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3077 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3078 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
3079 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
3080 vi->big_packets = true;
3081
3082 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
3083 vi->mergeable_rx_bufs = true;
3084
3085 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
3086 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3087 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
3088 else
3089 vi->hdr_len = sizeof(struct virtio_net_hdr);
3090
3091 if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
3092 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3093 vi->any_header_sg = true;
3094
3095 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3096 vi->has_cvq = true;
3097
3098 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3099 mtu = virtio_cread16(vdev,
3100 offsetof(struct virtio_net_config,
3101 mtu));
3102 if (mtu < dev->min_mtu) {
3103 /* Should never trigger: MTU was previously validated
3104 * in virtnet_validate.
3105 */
3106 dev_err(&vdev->dev,
3107 "device MTU appears to have changed it is now %d < %d",
3108 mtu, dev->min_mtu);
3109 goto free;
3110 }
3111
3112 dev->mtu = mtu;
3113 dev->max_mtu = mtu;
3114
3115 /* TODO: size buffers correctly in this case. */
3116 if (dev->mtu > ETH_DATA_LEN)
3117 vi->big_packets = true;
3118 }
3119
3120 if (vi->any_header_sg)
3121 dev->needed_headroom = vi->hdr_len;
3122
3123 /* Enable multiqueue by default */
3124 if (num_online_cpus() >= max_queue_pairs)
3125 vi->curr_queue_pairs = max_queue_pairs;
3126 else
3127 vi->curr_queue_pairs = num_online_cpus();
3128 vi->max_queue_pairs = max_queue_pairs;
3129
3130 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
3131 err = init_vqs(vi);
3132 if (err)
3133 goto free;
3134
3135#ifdef CONFIG_SYSFS
3136 if (vi->mergeable_rx_bufs)
3137 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
3138#endif
3139 netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
3140 netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
3141
3142 virtnet_init_settings(dev);
3143
3144 if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3145 vi->failover = net_failover_create(vi->dev);
3146 if (IS_ERR(vi->failover)) {
3147 err = PTR_ERR(vi->failover);
3148 goto free_vqs;
3149 }
3150 }
3151
3152 err = register_netdev(dev);
3153 if (err) {
3154 pr_debug("virtio_net: registering device failed\n");
3155 goto free_failover;
3156 }
3157
3158 virtio_device_ready(vdev);
3159
3160 err = virtnet_cpu_notif_add(vi);
3161 if (err) {
3162 pr_debug("virtio_net: registering cpu notifier failed\n");
3163 goto free_unregister_netdev;
3164 }
3165
3166 virtnet_set_queues(vi, vi->curr_queue_pairs);
3167
3168 /* Assume link up if device can't report link status,
3169 otherwise get link status from config. */
3170 netif_carrier_off(dev);
3171 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
3172 schedule_work(&vi->config_work);
3173 } else {
3174 vi->status = VIRTIO_NET_S_LINK_UP;
3175 virtnet_update_settings(vi);
3176 netif_carrier_on(dev);
3177 }
3178
3179 for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
3180 if (virtio_has_feature(vi->vdev, guest_offloads[i]))
3181 set_bit(guest_offloads[i], &vi->guest_offloads);
3182 vi->guest_offloads_capable = vi->guest_offloads;
3183
3184 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
3185 dev->name, max_queue_pairs);
3186
3187 return 0;
3188
3189free_unregister_netdev:
3190 vi->vdev->config->reset(vdev);
3191
3192 unregister_netdev(dev);
3193free_failover:
3194 net_failover_destroy(vi->failover);
3195free_vqs:
3196 cancel_delayed_work_sync(&vi->refill);
3197 free_receive_page_frags(vi);
3198 virtnet_del_vqs(vi);
3199free:
3200 free_netdev(dev);
3201 return err;
3202}
3203
3204static void remove_vq_common(struct virtnet_info *vi)
3205{
3206 vi->vdev->config->reset(vi->vdev);
3207
3208 /* Free unused buffers in both send and recv, if any. */
3209 free_unused_bufs(vi);
3210
3211 free_receive_bufs(vi);
3212
3213 free_receive_page_frags(vi);
3214
3215 virtnet_del_vqs(vi);
3216}
3217
3218static void virtnet_remove(struct virtio_device *vdev)
3219{
3220 struct virtnet_info *vi = vdev->priv;
3221
3222 virtnet_cpu_notif_remove(vi);
3223
3224 /* Make sure no work handler is accessing the device. */
3225 flush_work(&vi->config_work);
3226
3227 unregister_netdev(vi->dev);
3228
3229 net_failover_destroy(vi->failover);
3230
3231 remove_vq_common(vi);
3232
3233 free_netdev(vi->dev);
3234}
3235
3236static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
3237{
3238 struct virtnet_info *vi = vdev->priv;
3239
3240 virtnet_cpu_notif_remove(vi);
3241 virtnet_freeze_down(vdev);
3242 remove_vq_common(vi);
3243
3244 return 0;
3245}
3246
3247static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
3248{
3249 struct virtnet_info *vi = vdev->priv;
3250 int err;
3251
3252 err = virtnet_restore_up(vdev);
3253 if (err)
3254 return err;
3255 virtnet_set_queues(vi, vi->curr_queue_pairs);
3256
3257 err = virtnet_cpu_notif_add(vi);
3258 if (err)
3259 return err;
3260
3261 return 0;
3262}
3263
3264static struct virtio_device_id id_table[] = {
3265 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
3266 { 0 },
3267};
3268
3269#define VIRTNET_FEATURES \
3270 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
3271 VIRTIO_NET_F_MAC, \
3272 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
3273 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
3274 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
3275 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
3276 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
3277 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
3278 VIRTIO_NET_F_CTRL_MAC_ADDR, \
3279 VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
3280 VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
3281
3282static unsigned int features[] = {
3283 VIRTNET_FEATURES,
3284};
3285
3286static unsigned int features_legacy[] = {
3287 VIRTNET_FEATURES,
3288 VIRTIO_NET_F_GSO,
3289 VIRTIO_F_ANY_LAYOUT,
3290};
3291
3292static struct virtio_driver virtio_net_driver = {
3293 .feature_table = features,
3294 .feature_table_size = ARRAY_SIZE(features),
3295 .feature_table_legacy = features_legacy,
3296 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
3297 .driver.name = KBUILD_MODNAME,
3298 .driver.owner = THIS_MODULE,
3299 .id_table = id_table,
3300 .validate = virtnet_validate,
3301 .probe = virtnet_probe,
3302 .remove = virtnet_remove,
3303 .config_changed = virtnet_config_changed,
3304#ifdef CONFIG_PM_SLEEP
3305 .freeze = virtnet_freeze,
3306 .restore = virtnet_restore,
3307#endif
3308};
3309
3310static __init int virtio_net_driver_init(void)
3311{
3312 int ret;
3313
3314 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
3315 virtnet_cpu_online,
3316 virtnet_cpu_down_prep);
3317 if (ret < 0)
3318 goto out;
3319 virtionet_online = ret;
3320 ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
3321 NULL, virtnet_cpu_dead);
3322 if (ret)
3323 goto err_dead;
3324
3325 ret = register_virtio_driver(&virtio_net_driver);
3326 if (ret)
3327 goto err_virtio;
3328 return 0;
3329err_virtio:
3330 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3331err_dead:
3332 cpuhp_remove_multi_state(virtionet_online);
3333out:
3334 return ret;
3335}
3336module_init(virtio_net_driver_init);
3337
3338static __exit void virtio_net_driver_exit(void)
3339{
3340 unregister_virtio_driver(&virtio_net_driver);
3341 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3342 cpuhp_remove_multi_state(virtionet_online);
3343}
3344module_exit(virtio_net_driver_exit);
3345
3346MODULE_DEVICE_TABLE(virtio, id_table);
3347MODULE_DESCRIPTION("Virtio network driver");
3348MODULE_LICENSE("GPL");