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xtensa: support DMA buffers in high memory
[cris-mirror.git] / drivers / net / virtio_net.c
blob626c27352ae243fe6364d59d5274a718475a7587
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, see <http://www.gnu.org/licenses/>.
17 */
18 //#define DEBUG
19 #include <linux/netdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/ethtool.h>
22 #include <linux/module.h>
23 #include <linux/virtio.h>
24 #include <linux/virtio_net.h>
25 #include <linux/bpf.h>
26 #include <linux/bpf_trace.h>
27 #include <linux/scatterlist.h>
28 #include <linux/if_vlan.h>
29 #include <linux/slab.h>
30 #include <linux/cpu.h>
31 #include <linux/average.h>
32 #include <linux/filter.h>
33 #include <net/route.h>
34 #include <net/xdp.h>
35
36 static int napi_weight = NAPI_POLL_WEIGHT;
37 module_param(napi_weight, int, 0444);
38
39 static bool csum = true, gso = true, napi_tx;
40 module_param(csum, bool, 0444);
41 module_param(gso, bool, 0444);
42 module_param(napi_tx, bool, 0644);
43
44 /* FIXME: MTU in config. */
45 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
46 #define GOOD_COPY_LEN 128
47
48 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
49
50 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
51 #define VIRTIO_XDP_HEADROOM 256
52
53 /* RX packet size EWMA. The average packet size is used to determine the packet
54 * buffer size when refilling RX rings. As the entire RX ring may be refilled
55 * at once, the weight is chosen so that the EWMA will be insensitive to short-
56 * term, transient changes in packet size.
57 */
58 DECLARE_EWMA(pkt_len, 0, 64)
59
60 #define VIRTNET_DRIVER_VERSION "1.0.0"
61
62 static const unsigned long guest_offloads[] = {
63 VIRTIO_NET_F_GUEST_TSO4,
64 VIRTIO_NET_F_GUEST_TSO6,
65 VIRTIO_NET_F_GUEST_ECN,
66 VIRTIO_NET_F_GUEST_UFO
67 };
68
69 struct virtnet_stat_desc {
70 char desc[ETH_GSTRING_LEN];
71 size_t offset;
72 };
73
74 struct virtnet_sq_stats {
75 struct u64_stats_sync syncp;
76 u64 packets;
77 u64 bytes;
78 };
79
80 struct virtnet_rq_stats {
81 struct u64_stats_sync syncp;
82 u64 packets;
83 u64 bytes;
84 };
85
86 #define VIRTNET_SQ_STAT(m) offsetof(struct virtnet_sq_stats, m)
87 #define VIRTNET_RQ_STAT(m) offsetof(struct virtnet_rq_stats, m)
88
89 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
90 { "packets", VIRTNET_SQ_STAT(packets) },
91 { "bytes", VIRTNET_SQ_STAT(bytes) },
92 };
93
94 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
95 { "packets", VIRTNET_RQ_STAT(packets) },
96 { "bytes", VIRTNET_RQ_STAT(bytes) },
97 };
98
99 #define VIRTNET_SQ_STATS_LEN ARRAY_SIZE(virtnet_sq_stats_desc)
100 #define VIRTNET_RQ_STATS_LEN ARRAY_SIZE(virtnet_rq_stats_desc)
101
102 /* Internal representation of a send virtqueue */
103 struct send_queue {
104 /* Virtqueue associated with this send _queue */
105 struct virtqueue *vq;
106
107 /* TX: fragments + linear part + virtio header */
108 struct scatterlist sg[MAX_SKB_FRAGS + 2];
109
110 /* Name of the send queue: output.$index */
111 char name[40];
112
113 struct virtnet_sq_stats stats;
114
115 struct napi_struct napi;
116 };
117
118 /* Internal representation of a receive virtqueue */
119 struct receive_queue {
120 /* Virtqueue associated with this receive_queue */
121 struct virtqueue *vq;
122
123 struct napi_struct napi;
124
125 struct bpf_prog __rcu *xdp_prog;
126
127 struct virtnet_rq_stats stats;
128
129 /* Chain pages by the private ptr. */
130 struct page *pages;
131
132 /* Average packet length for mergeable receive buffers. */
133 struct ewma_pkt_len mrg_avg_pkt_len;
134
135 /* Page frag for packet buffer allocation. */
136 struct page_frag alloc_frag;
137
138 /* RX: fragments + linear part + virtio header */
139 struct scatterlist sg[MAX_SKB_FRAGS + 2];
140
141 /* Min single buffer size for mergeable buffers case. */
142 unsigned int min_buf_len;
143
144 /* Name of this receive queue: input.$index */
145 char name[40];
146
147 struct xdp_rxq_info xdp_rxq;
148 };
149
150 struct virtnet_info {
151 struct virtio_device *vdev;
152 struct virtqueue *cvq;
153 struct net_device *dev;
154 struct send_queue *sq;
155 struct receive_queue *rq;
156 unsigned int status;
157
158 /* Max # of queue pairs supported by the device */
159 u16 max_queue_pairs;
160
161 /* # of queue pairs currently used by the driver */
162 u16 curr_queue_pairs;
163
164 /* # of XDP queue pairs currently used by the driver */
165 u16 xdp_queue_pairs;
166
167 /* I like... big packets and I cannot lie! */
168 bool big_packets;
169
170 /* Host will merge rx buffers for big packets (shake it! shake it!) */
171 bool mergeable_rx_bufs;
172
173 /* Has control virtqueue */
174 bool has_cvq;
175
176 /* Host can handle any s/g split between our header and packet data */
177 bool any_header_sg;
178
179 /* Packet virtio header size */
180 u8 hdr_len;
181
182 /* Work struct for refilling if we run low on memory. */
183 struct delayed_work refill;
184
185 /* Work struct for config space updates */
186 struct work_struct config_work;
187
188 /* Does the affinity hint is set for virtqueues? */
189 bool affinity_hint_set;
190
191 /* CPU hotplug instances for online & dead */
192 struct hlist_node node;
193 struct hlist_node node_dead;
194
195 /* Control VQ buffers: protected by the rtnl lock */
196 struct virtio_net_ctrl_hdr ctrl_hdr;
197 virtio_net_ctrl_ack ctrl_status;
198 struct virtio_net_ctrl_mq ctrl_mq;
199 u8 ctrl_promisc;
200 u8 ctrl_allmulti;
201 u16 ctrl_vid;
202 u64 ctrl_offloads;
203
204 /* Ethtool settings */
205 u8 duplex;
206 u32 speed;
207
208 unsigned long guest_offloads;
209 };
210
211 struct padded_vnet_hdr {
212 struct virtio_net_hdr_mrg_rxbuf hdr;
213 /*
214 * hdr is in a separate sg buffer, and data sg buffer shares same page
215 * with this header sg. This padding makes next sg 16 byte aligned
216 * after the header.
217 */
218 char padding[4];
219 };
220
221 /* Converting between virtqueue no. and kernel tx/rx queue no.
222 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
223 */
224 static int vq2txq(struct virtqueue *vq)
225 {
226 return (vq->index - 1) / 2;
227 }
228
229 static int txq2vq(int txq)
230 {
231 return txq * 2 + 1;
232 }
233
234 static int vq2rxq(struct virtqueue *vq)
235 {
236 return vq->index / 2;
237 }
238
239 static int rxq2vq(int rxq)
240 {
241 return rxq * 2;
242 }
243
244 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
245 {
246 return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
247 }
248
249 /*
250 * private is used to chain pages for big packets, put the whole
251 * most recent used list in the beginning for reuse
252 */
253 static void give_pages(struct receive_queue *rq, struct page *page)
254 {
255 struct page *end;
256
257 /* Find end of list, sew whole thing into vi->rq.pages. */
258 for (end = page; end->private; end = (struct page *)end->private);
259 end->private = (unsigned long)rq->pages;
260 rq->pages = page;
261 }
262
263 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
264 {
265 struct page *p = rq->pages;
266
267 if (p) {
268 rq->pages = (struct page *)p->private;
269 /* clear private here, it is used to chain pages */
270 p->private = 0;
271 } else
272 p = alloc_page(gfp_mask);
273 return p;
274 }
275
276 static void virtqueue_napi_schedule(struct napi_struct *napi,
277 struct virtqueue *vq)
278 {
279 if (napi_schedule_prep(napi)) {
280 virtqueue_disable_cb(vq);
281 __napi_schedule(napi);
282 }
283 }
284
285 static void virtqueue_napi_complete(struct napi_struct *napi,
286 struct virtqueue *vq, int processed)
287 {
288 int opaque;
289
290 opaque = virtqueue_enable_cb_prepare(vq);
291 if (napi_complete_done(napi, processed)) {
292 if (unlikely(virtqueue_poll(vq, opaque)))
293 virtqueue_napi_schedule(napi, vq);
294 } else {
295 virtqueue_disable_cb(vq);
296 }
297 }
298
299 static void skb_xmit_done(struct virtqueue *vq)
300 {
301 struct virtnet_info *vi = vq->vdev->priv;
302 struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
303
304 /* Suppress further interrupts. */
305 virtqueue_disable_cb(vq);
306
307 if (napi->weight)
308 virtqueue_napi_schedule(napi, vq);
309 else
310 /* We were probably waiting for more output buffers. */
311 netif_wake_subqueue(vi->dev, vq2txq(vq));
312 }
313
314 #define MRG_CTX_HEADER_SHIFT 22
315 static void *mergeable_len_to_ctx(unsigned int truesize,
316 unsigned int headroom)
317 {
318 return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
319 }
320
321 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
322 {
323 return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
324 }
325
326 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
327 {
328 return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
329 }
330
331 /* Called from bottom half context */
332 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
333 struct receive_queue *rq,
334 struct page *page, unsigned int offset,
335 unsigned int len, unsigned int truesize)
336 {
337 struct sk_buff *skb;
338 struct virtio_net_hdr_mrg_rxbuf *hdr;
339 unsigned int copy, hdr_len, hdr_padded_len;
340 char *p;
341
342 p = page_address(page) + offset;
343
344 /* copy small packet so we can reuse these pages for small data */
345 skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
346 if (unlikely(!skb))
347 return NULL;
348
349 hdr = skb_vnet_hdr(skb);
350
351 hdr_len = vi->hdr_len;
352 if (vi->mergeable_rx_bufs)
353 hdr_padded_len = sizeof(*hdr);
354 else
355 hdr_padded_len = sizeof(struct padded_vnet_hdr);
356
357 memcpy(hdr, p, hdr_len);
358
359 len -= hdr_len;
360 offset += hdr_padded_len;
361 p += hdr_padded_len;
362
363 copy = len;
364 if (copy > skb_tailroom(skb))
365 copy = skb_tailroom(skb);
366 skb_put_data(skb, p, copy);
367
368 len -= copy;
369 offset += copy;
370
371 if (vi->mergeable_rx_bufs) {
372 if (len)
373 skb_add_rx_frag(skb, 0, page, offset, len, truesize);
374 else
375 put_page(page);
376 return skb;
377 }
378
379 /*
380 * Verify that we can indeed put this data into a skb.
381 * This is here to handle cases when the device erroneously
382 * tries to receive more than is possible. This is usually
383 * the case of a broken device.
384 */
385 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
386 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
387 dev_kfree_skb(skb);
388 return NULL;
389 }
390 BUG_ON(offset >= PAGE_SIZE);
391 while (len) {
392 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
393 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
394 frag_size, truesize);
395 len -= frag_size;
396 page = (struct page *)page->private;
397 offset = 0;
398 }
399
400 if (page)
401 give_pages(rq, page);
402
403 return skb;
404 }
405
406 static void virtnet_xdp_flush(struct net_device *dev)
407 {
408 struct virtnet_info *vi = netdev_priv(dev);
409 struct send_queue *sq;
410 unsigned int qp;
411
412 qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
413 sq = &vi->sq[qp];
414
415 virtqueue_kick(sq->vq);
416 }
417
418 static bool __virtnet_xdp_xmit(struct virtnet_info *vi,
419 struct xdp_buff *xdp)
420 {
421 struct virtio_net_hdr_mrg_rxbuf *hdr;
422 unsigned int len;
423 struct send_queue *sq;
424 unsigned int qp;
425 void *xdp_sent;
426 int err;
427
428 qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
429 sq = &vi->sq[qp];
430
431 /* Free up any pending old buffers before queueing new ones. */
432 while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) {
433 struct page *sent_page = virt_to_head_page(xdp_sent);
434
435 put_page(sent_page);
436 }
437
438 xdp->data -= vi->hdr_len;
439 /* Zero header and leave csum up to XDP layers */
440 hdr = xdp->data;
441 memset(hdr, 0, vi->hdr_len);
442
443 sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data);
444
445 err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp->data, GFP_ATOMIC);
446 if (unlikely(err)) {
447 struct page *page = virt_to_head_page(xdp->data);
448
449 put_page(page);
450 return false;
451 }
452
453 return true;
454 }
455
456 static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp)
457 {
458 struct virtnet_info *vi = netdev_priv(dev);
459 bool sent = __virtnet_xdp_xmit(vi, xdp);
460
461 if (!sent)
462 return -ENOSPC;
463 return 0;
464 }
465
466 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
467 {
468 return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
469 }
470
471 /* We copy the packet for XDP in the following cases:
472 *
473 * 1) Packet is scattered across multiple rx buffers.
474 * 2) Headroom space is insufficient.
475 *
476 * This is inefficient but it's a temporary condition that
477 * we hit right after XDP is enabled and until queue is refilled
478 * with large buffers with sufficient headroom - so it should affect
479 * at most queue size packets.
480 * Afterwards, the conditions to enable
481 * XDP should preclude the underlying device from sending packets
482 * across multiple buffers (num_buf > 1), and we make sure buffers
483 * have enough headroom.
484 */
485 static struct page *xdp_linearize_page(struct receive_queue *rq,
486 u16 *num_buf,
487 struct page *p,
488 int offset,
489 int page_off,
490 unsigned int *len)
491 {
492 struct page *page = alloc_page(GFP_ATOMIC);
493
494 if (!page)
495 return NULL;
496
497 memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
498 page_off += *len;
499
500 while (--*num_buf) {
501 unsigned int buflen;
502 void *buf;
503 int off;
504
505 buf = virtqueue_get_buf(rq->vq, &buflen);
506 if (unlikely(!buf))
507 goto err_buf;
508
509 p = virt_to_head_page(buf);
510 off = buf - page_address(p);
511
512 /* guard against a misconfigured or uncooperative backend that
513 * is sending packet larger than the MTU.
514 */
515 if ((page_off + buflen) > PAGE_SIZE) {
516 put_page(p);
517 goto err_buf;
518 }
519
520 memcpy(page_address(page) + page_off,
521 page_address(p) + off, buflen);
522 page_off += buflen;
523 put_page(p);
524 }
525
526 /* Headroom does not contribute to packet length */
527 *len = page_off - VIRTIO_XDP_HEADROOM;
528 return page;
529 err_buf:
530 __free_pages(page, 0);
531 return NULL;
532 }
533
534 static struct sk_buff *receive_small(struct net_device *dev,
535 struct virtnet_info *vi,
536 struct receive_queue *rq,
537 void *buf, void *ctx,
538 unsigned int len,
539 bool *xdp_xmit)
540 {
541 struct sk_buff *skb;
542 struct bpf_prog *xdp_prog;
543 unsigned int xdp_headroom = (unsigned long)ctx;
544 unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
545 unsigned int headroom = vi->hdr_len + header_offset;
546 unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
547 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
548 struct page *page = virt_to_head_page(buf);
549 unsigned int delta = 0, err;
550 struct page *xdp_page;
551 len -= vi->hdr_len;
552
553 rcu_read_lock();
554 xdp_prog = rcu_dereference(rq->xdp_prog);
555 if (xdp_prog) {
556 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
557 struct xdp_buff xdp;
558 void *orig_data;
559 u32 act;
560
561 if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
562 goto err_xdp;
563
564 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
565 int offset = buf - page_address(page) + header_offset;
566 unsigned int tlen = len + vi->hdr_len;
567 u16 num_buf = 1;
568
569 xdp_headroom = virtnet_get_headroom(vi);
570 header_offset = VIRTNET_RX_PAD + xdp_headroom;
571 headroom = vi->hdr_len + header_offset;
572 buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
573 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
574 xdp_page = xdp_linearize_page(rq, &num_buf, page,
575 offset, header_offset,
576 &tlen);
577 if (!xdp_page)
578 goto err_xdp;
579
580 buf = page_address(xdp_page);
581 put_page(page);
582 page = xdp_page;
583 }
584
585 xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
586 xdp.data = xdp.data_hard_start + xdp_headroom;
587 xdp_set_data_meta_invalid(&xdp);
588 xdp.data_end = xdp.data + len;
589 xdp.rxq = &rq->xdp_rxq;
590 orig_data = xdp.data;
591 act = bpf_prog_run_xdp(xdp_prog, &xdp);
592
593 switch (act) {
594 case XDP_PASS:
595 /* Recalculate length in case bpf program changed it */
596 delta = orig_data - xdp.data;
597 break;
598 case XDP_TX:
599 if (unlikely(!__virtnet_xdp_xmit(vi, &xdp)))
600 trace_xdp_exception(vi->dev, xdp_prog, act);
601 else
602 *xdp_xmit = true;
603 rcu_read_unlock();
604 goto xdp_xmit;
605 case XDP_REDIRECT:
606 err = xdp_do_redirect(dev, &xdp, xdp_prog);
607 if (!err)
608 *xdp_xmit = true;
609 rcu_read_unlock();
610 goto xdp_xmit;
611 default:
612 bpf_warn_invalid_xdp_action(act);
613 case XDP_ABORTED:
614 trace_xdp_exception(vi->dev, xdp_prog, act);
615 case XDP_DROP:
616 goto err_xdp;
617 }
618 }
619 rcu_read_unlock();
620
621 skb = build_skb(buf, buflen);
622 if (!skb) {
623 put_page(page);
624 goto err;
625 }
626 skb_reserve(skb, headroom - delta);
627 skb_put(skb, len + delta);
628 if (!delta) {
629 buf += header_offset;
630 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
631 } /* keep zeroed vnet hdr since packet was changed by bpf */
632
633 err:
634 return skb;
635
636 err_xdp:
637 rcu_read_unlock();
638 dev->stats.rx_dropped++;
639 put_page(page);
640 xdp_xmit:
641 return NULL;
642 }
643
644 static struct sk_buff *receive_big(struct net_device *dev,
645 struct virtnet_info *vi,
646 struct receive_queue *rq,
647 void *buf,
648 unsigned int len)
649 {
650 struct page *page = buf;
651 struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
652
653 if (unlikely(!skb))
654 goto err;
655
656 return skb;
657
658 err:
659 dev->stats.rx_dropped++;
660 give_pages(rq, page);
661 return NULL;
662 }
663
664 static struct sk_buff *receive_mergeable(struct net_device *dev,
665 struct virtnet_info *vi,
666 struct receive_queue *rq,
667 void *buf,
668 void *ctx,
669 unsigned int len,
670 bool *xdp_xmit)
671 {
672 struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
673 u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
674 struct page *page = virt_to_head_page(buf);
675 int offset = buf - page_address(page);
676 struct sk_buff *head_skb, *curr_skb;
677 struct bpf_prog *xdp_prog;
678 unsigned int truesize;
679 unsigned int headroom = mergeable_ctx_to_headroom(ctx);
680 int err;
681
682 head_skb = NULL;
683
684 rcu_read_lock();
685 xdp_prog = rcu_dereference(rq->xdp_prog);
686 if (xdp_prog) {
687 struct page *xdp_page;
688 struct xdp_buff xdp;
689 void *data;
690 u32 act;
691
692 /* This happens when rx buffer size is underestimated */
693 if (unlikely(num_buf > 1 ||
694 headroom < virtnet_get_headroom(vi))) {
695 /* linearize data for XDP */
696 xdp_page = xdp_linearize_page(rq, &num_buf,
697 page, offset,
698 VIRTIO_XDP_HEADROOM,
699 &len);
700 if (!xdp_page)
701 goto err_xdp;
702 offset = VIRTIO_XDP_HEADROOM;
703 } else {
704 xdp_page = page;
705 }
706
707 /* Transient failure which in theory could occur if
708 * in-flight packets from before XDP was enabled reach
709 * the receive path after XDP is loaded. In practice I
710 * was not able to create this condition.
711 */
712 if (unlikely(hdr->hdr.gso_type))
713 goto err_xdp;
714
715 /* Allow consuming headroom but reserve enough space to push
716 * the descriptor on if we get an XDP_TX return code.
717 */
718 data = page_address(xdp_page) + offset;
719 xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
720 xdp.data = data + vi->hdr_len;
721 xdp_set_data_meta_invalid(&xdp);
722 xdp.data_end = xdp.data + (len - vi->hdr_len);
723 xdp.rxq = &rq->xdp_rxq;
724
725 act = bpf_prog_run_xdp(xdp_prog, &xdp);
726
727 if (act != XDP_PASS)
728 ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len);
729
730 switch (act) {
731 case XDP_PASS:
732 /* recalculate offset to account for any header
733 * adjustments. Note other cases do not build an
734 * skb and avoid using offset
735 */
736 offset = xdp.data -
737 page_address(xdp_page) - vi->hdr_len;
738
739 /* We can only create skb based on xdp_page. */
740 if (unlikely(xdp_page != page)) {
741 rcu_read_unlock();
742 put_page(page);
743 head_skb = page_to_skb(vi, rq, xdp_page,
744 offset, len, PAGE_SIZE);
745 return head_skb;
746 }
747 break;
748 case XDP_TX:
749 if (unlikely(!__virtnet_xdp_xmit(vi, &xdp)))
750 trace_xdp_exception(vi->dev, xdp_prog, act);
751 else
752 *xdp_xmit = true;
753 if (unlikely(xdp_page != page))
754 goto err_xdp;
755 rcu_read_unlock();
756 goto xdp_xmit;
757 case XDP_REDIRECT:
758 err = xdp_do_redirect(dev, &xdp, xdp_prog);
759 if (!err)
760 *xdp_xmit = true;
761 rcu_read_unlock();
762 goto xdp_xmit;
763 default:
764 bpf_warn_invalid_xdp_action(act);
765 case XDP_ABORTED:
766 trace_xdp_exception(vi->dev, xdp_prog, act);
767 case XDP_DROP:
768 if (unlikely(xdp_page != page))
769 __free_pages(xdp_page, 0);
770 goto err_xdp;
771 }
772 }
773 rcu_read_unlock();
774
775 truesize = mergeable_ctx_to_truesize(ctx);
776 if (unlikely(len > truesize)) {
777 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
778 dev->name, len, (unsigned long)ctx);
779 dev->stats.rx_length_errors++;
780 goto err_skb;
781 }
782
783 head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
784 curr_skb = head_skb;
785
786 if (unlikely(!curr_skb))
787 goto err_skb;
788 while (--num_buf) {
789 int num_skb_frags;
790
791 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
792 if (unlikely(!buf)) {
793 pr_debug("%s: rx error: %d buffers out of %d missing\n",
794 dev->name, num_buf,
795 virtio16_to_cpu(vi->vdev,
796 hdr->num_buffers));
797 dev->stats.rx_length_errors++;
798 goto err_buf;
799 }
800
801 page = virt_to_head_page(buf);
802
803 truesize = mergeable_ctx_to_truesize(ctx);
804 if (unlikely(len > truesize)) {
805 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
806 dev->name, len, (unsigned long)ctx);
807 dev->stats.rx_length_errors++;
808 goto err_skb;
809 }
810
811 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
812 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
813 struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
814
815 if (unlikely(!nskb))
816 goto err_skb;
817 if (curr_skb == head_skb)
818 skb_shinfo(curr_skb)->frag_list = nskb;
819 else
820 curr_skb->next = nskb;
821 curr_skb = nskb;
822 head_skb->truesize += nskb->truesize;
823 num_skb_frags = 0;
824 }
825 if (curr_skb != head_skb) {
826 head_skb->data_len += len;
827 head_skb->len += len;
828 head_skb->truesize += truesize;
829 }
830 offset = buf - page_address(page);
831 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
832 put_page(page);
833 skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
834 len, truesize);
835 } else {
836 skb_add_rx_frag(curr_skb, num_skb_frags, page,
837 offset, len, truesize);
838 }
839 }
840
841 ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
842 return head_skb;
843
844 err_xdp:
845 rcu_read_unlock();
846 err_skb:
847 put_page(page);
848 while (--num_buf) {
849 buf = virtqueue_get_buf(rq->vq, &len);
850 if (unlikely(!buf)) {
851 pr_debug("%s: rx error: %d buffers missing\n",
852 dev->name, num_buf);
853 dev->stats.rx_length_errors++;
854 break;
855 }
856 page = virt_to_head_page(buf);
857 put_page(page);
858 }
859 err_buf:
860 dev->stats.rx_dropped++;
861 dev_kfree_skb(head_skb);
862 xdp_xmit:
863 return NULL;
864 }
865
866 static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
867 void *buf, unsigned int len, void **ctx, bool *xdp_xmit)
868 {
869 struct net_device *dev = vi->dev;
870 struct sk_buff *skb;
871 struct virtio_net_hdr_mrg_rxbuf *hdr;
872 int ret;
873
874 if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
875 pr_debug("%s: short packet %i\n", dev->name, len);
876 dev->stats.rx_length_errors++;
877 if (vi->mergeable_rx_bufs) {
878 put_page(virt_to_head_page(buf));
879 } else if (vi->big_packets) {
880 give_pages(rq, buf);
881 } else {
882 put_page(virt_to_head_page(buf));
883 }
884 return 0;
885 }
886
887 if (vi->mergeable_rx_bufs)
888 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit);
889 else if (vi->big_packets)
890 skb = receive_big(dev, vi, rq, buf, len);
891 else
892 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit);
893
894 if (unlikely(!skb))
895 return 0;
896
897 hdr = skb_vnet_hdr(skb);
898
899 ret = skb->len;
900
901 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
902 skb->ip_summed = CHECKSUM_UNNECESSARY;
903
904 if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
905 virtio_is_little_endian(vi->vdev))) {
906 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
907 dev->name, hdr->hdr.gso_type,
908 hdr->hdr.gso_size);
909 goto frame_err;
910 }
911
912 skb->protocol = eth_type_trans(skb, dev);
913 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
914 ntohs(skb->protocol), skb->len, skb->pkt_type);
915
916 napi_gro_receive(&rq->napi, skb);
917 return ret;
918
919 frame_err:
920 dev->stats.rx_frame_errors++;
921 dev_kfree_skb(skb);
922 return 0;
923 }
924
925 /* Unlike mergeable buffers, all buffers are allocated to the
926 * same size, except for the headroom. For this reason we do
927 * not need to use mergeable_len_to_ctx here - it is enough
928 * to store the headroom as the context ignoring the truesize.
929 */
930 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
931 gfp_t gfp)
932 {
933 struct page_frag *alloc_frag = &rq->alloc_frag;
934 char *buf;
935 unsigned int xdp_headroom = virtnet_get_headroom(vi);
936 void *ctx = (void *)(unsigned long)xdp_headroom;
937 int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
938 int err;
939
940 len = SKB_DATA_ALIGN(len) +
941 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
942 if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
943 return -ENOMEM;
944
945 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
946 get_page(alloc_frag->page);
947 alloc_frag->offset += len;
948 sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
949 vi->hdr_len + GOOD_PACKET_LEN);
950 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
951 if (err < 0)
952 put_page(virt_to_head_page(buf));
953 return err;
954 }
955
956 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
957 gfp_t gfp)
958 {
959 struct page *first, *list = NULL;
960 char *p;
961 int i, err, offset;
962
963 sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
964
965 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
966 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
967 first = get_a_page(rq, gfp);
968 if (!first) {
969 if (list)
970 give_pages(rq, list);
971 return -ENOMEM;
972 }
973 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
974
975 /* chain new page in list head to match sg */
976 first->private = (unsigned long)list;
977 list = first;
978 }
979
980 first = get_a_page(rq, gfp);
981 if (!first) {
982 give_pages(rq, list);
983 return -ENOMEM;
984 }
985 p = page_address(first);
986
987 /* rq->sg[0], rq->sg[1] share the same page */
988 /* a separated rq->sg[0] for header - required in case !any_header_sg */
989 sg_set_buf(&rq->sg[0], p, vi->hdr_len);
990
991 /* rq->sg[1] for data packet, from offset */
992 offset = sizeof(struct padded_vnet_hdr);
993 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
994
995 /* chain first in list head */
996 first->private = (unsigned long)list;
997 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
998 first, gfp);
999 if (err < 0)
1000 give_pages(rq, first);
1001
1002 return err;
1003 }
1004
1005 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1006 struct ewma_pkt_len *avg_pkt_len)
1007 {
1008 const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1009 unsigned int len;
1010
1011 len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1012 rq->min_buf_len, PAGE_SIZE - hdr_len);
1013 return ALIGN(len, L1_CACHE_BYTES);
1014 }
1015
1016 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1017 struct receive_queue *rq, gfp_t gfp)
1018 {
1019 struct page_frag *alloc_frag = &rq->alloc_frag;
1020 unsigned int headroom = virtnet_get_headroom(vi);
1021 char *buf;
1022 void *ctx;
1023 int err;
1024 unsigned int len, hole;
1025
1026 len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len);
1027 if (unlikely(!skb_page_frag_refill(len + headroom, alloc_frag, gfp)))
1028 return -ENOMEM;
1029
1030 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1031 buf += headroom; /* advance address leaving hole at front of pkt */
1032 get_page(alloc_frag->page);
1033 alloc_frag->offset += len + headroom;
1034 hole = alloc_frag->size - alloc_frag->offset;
1035 if (hole < len + headroom) {
1036 /* To avoid internal fragmentation, if there is very likely not
1037 * enough space for another buffer, add the remaining space to
1038 * the current buffer.
1039 */
1040 len += hole;
1041 alloc_frag->offset += hole;
1042 }
1043
1044 sg_init_one(rq->sg, buf, len);
1045 ctx = mergeable_len_to_ctx(len, headroom);
1046 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1047 if (err < 0)
1048 put_page(virt_to_head_page(buf));
1049
1050 return err;
1051 }
1052
1053 /*
1054 * Returns false if we couldn't fill entirely (OOM).
1055 *
1056 * Normally run in the receive path, but can also be run from ndo_open
1057 * before we're receiving packets, or from refill_work which is
1058 * careful to disable receiving (using napi_disable).
1059 */
1060 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1061 gfp_t gfp)
1062 {
1063 int err;
1064 bool oom;
1065
1066 do {
1067 if (vi->mergeable_rx_bufs)
1068 err = add_recvbuf_mergeable(vi, rq, gfp);
1069 else if (vi->big_packets)
1070 err = add_recvbuf_big(vi, rq, gfp);
1071 else
1072 err = add_recvbuf_small(vi, rq, gfp);
1073
1074 oom = err == -ENOMEM;
1075 if (err)
1076 break;
1077 } while (rq->vq->num_free);
1078 virtqueue_kick(rq->vq);
1079 return !oom;
1080 }
1081
1082 static void skb_recv_done(struct virtqueue *rvq)
1083 {
1084 struct virtnet_info *vi = rvq->vdev->priv;
1085 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1086
1087 virtqueue_napi_schedule(&rq->napi, rvq);
1088 }
1089
1090 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1091 {
1092 napi_enable(napi);
1093
1094 /* If all buffers were filled by other side before we napi_enabled, we
1095 * won't get another interrupt, so process any outstanding packets now.
1096 * Call local_bh_enable after to trigger softIRQ processing.
1097 */
1098 local_bh_disable();
1099 virtqueue_napi_schedule(napi, vq);
1100 local_bh_enable();
1101 }
1102
1103 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1104 struct virtqueue *vq,
1105 struct napi_struct *napi)
1106 {
1107 if (!napi->weight)
1108 return;
1109
1110 /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1111 * enable the feature if this is likely affine with the transmit path.
1112 */
1113 if (!vi->affinity_hint_set) {
1114 napi->weight = 0;
1115 return;
1116 }
1117
1118 return virtnet_napi_enable(vq, napi);
1119 }
1120
1121 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1122 {
1123 if (napi->weight)
1124 napi_disable(napi);
1125 }
1126
1127 static void refill_work(struct work_struct *work)
1128 {
1129 struct virtnet_info *vi =
1130 container_of(work, struct virtnet_info, refill.work);
1131 bool still_empty;
1132 int i;
1133
1134 for (i = 0; i < vi->curr_queue_pairs; i++) {
1135 struct receive_queue *rq = &vi->rq[i];
1136
1137 napi_disable(&rq->napi);
1138 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1139 virtnet_napi_enable(rq->vq, &rq->napi);
1140
1141 /* In theory, this can happen: if we don't get any buffers in
1142 * we will *never* try to fill again.
1143 */
1144 if (still_empty)
1145 schedule_delayed_work(&vi->refill, HZ/2);
1146 }
1147 }
1148
1149 static int virtnet_receive(struct receive_queue *rq, int budget, bool *xdp_xmit)
1150 {
1151 struct virtnet_info *vi = rq->vq->vdev->priv;
1152 unsigned int len, received = 0, bytes = 0;
1153 void *buf;
1154
1155 if (!vi->big_packets || vi->mergeable_rx_bufs) {
1156 void *ctx;
1157
1158 while (received < budget &&
1159 (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1160 bytes += receive_buf(vi, rq, buf, len, ctx, xdp_xmit);
1161 received++;
1162 }
1163 } else {
1164 while (received < budget &&
1165 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1166 bytes += receive_buf(vi, rq, buf, len, NULL, xdp_xmit);
1167 received++;
1168 }
1169 }
1170
1171 if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
1172 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1173 schedule_delayed_work(&vi->refill, 0);
1174 }
1175
1176 u64_stats_update_begin(&rq->stats.syncp);
1177 rq->stats.bytes += bytes;
1178 rq->stats.packets += received;
1179 u64_stats_update_end(&rq->stats.syncp);
1180
1181 return received;
1182 }
1183
1184 static void free_old_xmit_skbs(struct send_queue *sq)
1185 {
1186 struct sk_buff *skb;
1187 unsigned int len;
1188 unsigned int packets = 0;
1189 unsigned int bytes = 0;
1190
1191 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1192 pr_debug("Sent skb %p\n", skb);
1193
1194 bytes += skb->len;
1195 packets++;
1196
1197 dev_consume_skb_any(skb);
1198 }
1199
1200 /* Avoid overhead when no packets have been processed
1201 * happens when called speculatively from start_xmit.
1202 */
1203 if (!packets)
1204 return;
1205
1206 u64_stats_update_begin(&sq->stats.syncp);
1207 sq->stats.bytes += bytes;
1208 sq->stats.packets += packets;
1209 u64_stats_update_end(&sq->stats.syncp);
1210 }
1211
1212 static void virtnet_poll_cleantx(struct receive_queue *rq)
1213 {
1214 struct virtnet_info *vi = rq->vq->vdev->priv;
1215 unsigned int index = vq2rxq(rq->vq);
1216 struct send_queue *sq = &vi->sq[index];
1217 struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1218
1219 if (!sq->napi.weight)
1220 return;
1221
1222 if (__netif_tx_trylock(txq)) {
1223 free_old_xmit_skbs(sq);
1224 __netif_tx_unlock(txq);
1225 }
1226
1227 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1228 netif_tx_wake_queue(txq);
1229 }
1230
1231 static int virtnet_poll(struct napi_struct *napi, int budget)
1232 {
1233 struct receive_queue *rq =
1234 container_of(napi, struct receive_queue, napi);
1235 unsigned int received;
1236 bool xdp_xmit = false;
1237
1238 virtnet_poll_cleantx(rq);
1239
1240 received = virtnet_receive(rq, budget, &xdp_xmit);
1241
1242 /* Out of packets? */
1243 if (received < budget)
1244 virtqueue_napi_complete(napi, rq->vq, received);
1245
1246 if (xdp_xmit)
1247 xdp_do_flush_map();
1248
1249 return received;
1250 }
1251
1252 static int virtnet_open(struct net_device *dev)
1253 {
1254 struct virtnet_info *vi = netdev_priv(dev);
1255 int i, err;
1256
1257 for (i = 0; i < vi->max_queue_pairs; i++) {
1258 if (i < vi->curr_queue_pairs)
1259 /* Make sure we have some buffers: if oom use wq. */
1260 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1261 schedule_delayed_work(&vi->refill, 0);
1262
1263 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i);
1264 if (err < 0)
1265 return err;
1266
1267 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1268 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1269 }
1270
1271 return 0;
1272 }
1273
1274 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1275 {
1276 struct send_queue *sq = container_of(napi, struct send_queue, napi);
1277 struct virtnet_info *vi = sq->vq->vdev->priv;
1278 struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
1279
1280 __netif_tx_lock(txq, raw_smp_processor_id());
1281 free_old_xmit_skbs(sq);
1282 __netif_tx_unlock(txq);
1283
1284 virtqueue_napi_complete(napi, sq->vq, 0);
1285
1286 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1287 netif_tx_wake_queue(txq);
1288
1289 return 0;
1290 }
1291
1292 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1293 {
1294 struct virtio_net_hdr_mrg_rxbuf *hdr;
1295 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1296 struct virtnet_info *vi = sq->vq->vdev->priv;
1297 int num_sg;
1298 unsigned hdr_len = vi->hdr_len;
1299 bool can_push;
1300
1301 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1302
1303 can_push = vi->any_header_sg &&
1304 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1305 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1306 /* Even if we can, don't push here yet as this would skew
1307 * csum_start offset below. */
1308 if (can_push)
1309 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1310 else
1311 hdr = skb_vnet_hdr(skb);
1312
1313 if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1314 virtio_is_little_endian(vi->vdev), false))
1315 BUG();
1316
1317 if (vi->mergeable_rx_bufs)
1318 hdr->num_buffers = 0;
1319
1320 sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1321 if (can_push) {
1322 __skb_push(skb, hdr_len);
1323 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1324 if (unlikely(num_sg < 0))
1325 return num_sg;
1326 /* Pull header back to avoid skew in tx bytes calculations. */
1327 __skb_pull(skb, hdr_len);
1328 } else {
1329 sg_set_buf(sq->sg, hdr, hdr_len);
1330 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1331 if (unlikely(num_sg < 0))
1332 return num_sg;
1333 num_sg++;
1334 }
1335 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1336 }
1337
1338 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1339 {
1340 struct virtnet_info *vi = netdev_priv(dev);
1341 int qnum = skb_get_queue_mapping(skb);
1342 struct send_queue *sq = &vi->sq[qnum];
1343 int err;
1344 struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1345 bool kick = !skb->xmit_more;
1346 bool use_napi = sq->napi.weight;
1347
1348 /* Free up any pending old buffers before queueing new ones. */
1349 free_old_xmit_skbs(sq);
1350
1351 if (use_napi && kick)
1352 virtqueue_enable_cb_delayed(sq->vq);
1353
1354 /* timestamp packet in software */
1355 skb_tx_timestamp(skb);
1356
1357 /* Try to transmit */
1358 err = xmit_skb(sq, skb);
1359
1360 /* This should not happen! */
1361 if (unlikely(err)) {
1362 dev->stats.tx_fifo_errors++;
1363 if (net_ratelimit())
1364 dev_warn(&dev->dev,
1365 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
1366 dev->stats.tx_dropped++;
1367 dev_kfree_skb_any(skb);
1368 return NETDEV_TX_OK;
1369 }
1370
1371 /* Don't wait up for transmitted skbs to be freed. */
1372 if (!use_napi) {
1373 skb_orphan(skb);
1374 nf_reset(skb);
1375 }
1376
1377 /* If running out of space, stop queue to avoid getting packets that we
1378 * are then unable to transmit.
1379 * An alternative would be to force queuing layer to requeue the skb by
1380 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1381 * returned in a normal path of operation: it means that driver is not
1382 * maintaining the TX queue stop/start state properly, and causes
1383 * the stack to do a non-trivial amount of useless work.
1384 * Since most packets only take 1 or 2 ring slots, stopping the queue
1385 * early means 16 slots are typically wasted.
1386 */
1387 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1388 netif_stop_subqueue(dev, qnum);
1389 if (!use_napi &&
1390 unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1391 /* More just got used, free them then recheck. */
1392 free_old_xmit_skbs(sq);
1393 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1394 netif_start_subqueue(dev, qnum);
1395 virtqueue_disable_cb(sq->vq);
1396 }
1397 }
1398 }
1399
1400 if (kick || netif_xmit_stopped(txq))
1401 virtqueue_kick(sq->vq);
1402
1403 return NETDEV_TX_OK;
1404 }
1405
1406 /*
1407 * Send command via the control virtqueue and check status. Commands
1408 * supported by the hypervisor, as indicated by feature bits, should
1409 * never fail unless improperly formatted.
1410 */
1411 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1412 struct scatterlist *out)
1413 {
1414 struct scatterlist *sgs[4], hdr, stat;
1415 unsigned out_num = 0, tmp;
1416
1417 /* Caller should know better */
1418 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1419
1420 vi->ctrl_status = ~0;
1421 vi->ctrl_hdr.class = class;
1422 vi->ctrl_hdr.cmd = cmd;
1423 /* Add header */
1424 sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
1425 sgs[out_num++] = &hdr;
1426
1427 if (out)
1428 sgs[out_num++] = out;
1429
1430 /* Add return status. */
1431 sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
1432 sgs[out_num] = &stat;
1433
1434 BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1435 virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1436
1437 if (unlikely(!virtqueue_kick(vi->cvq)))
1438 return vi->ctrl_status == VIRTIO_NET_OK;
1439
1440 /* Spin for a response, the kick causes an ioport write, trapping
1441 * into the hypervisor, so the request should be handled immediately.
1442 */
1443 while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1444 !virtqueue_is_broken(vi->cvq))
1445 cpu_relax();
1446
1447 return vi->ctrl_status == VIRTIO_NET_OK;
1448 }
1449
1450 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1451 {
1452 struct virtnet_info *vi = netdev_priv(dev);
1453 struct virtio_device *vdev = vi->vdev;
1454 int ret;
1455 struct sockaddr *addr;
1456 struct scatterlist sg;
1457
1458 addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1459 if (!addr)
1460 return -ENOMEM;
1461
1462 ret = eth_prepare_mac_addr_change(dev, addr);
1463 if (ret)
1464 goto out;
1465
1466 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1467 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1468 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1469 VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1470 dev_warn(&vdev->dev,
1471 "Failed to set mac address by vq command.\n");
1472 ret = -EINVAL;
1473 goto out;
1474 }
1475 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1476 !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1477 unsigned int i;
1478
1479 /* Naturally, this has an atomicity problem. */
1480 for (i = 0; i < dev->addr_len; i++)
1481 virtio_cwrite8(vdev,
1482 offsetof(struct virtio_net_config, mac) +
1483 i, addr->sa_data[i]);
1484 }
1485
1486 eth_commit_mac_addr_change(dev, p);
1487 ret = 0;
1488
1489 out:
1490 kfree(addr);
1491 return ret;
1492 }
1493
1494 static void virtnet_stats(struct net_device *dev,
1495 struct rtnl_link_stats64 *tot)
1496 {
1497 struct virtnet_info *vi = netdev_priv(dev);
1498 unsigned int start;
1499 int i;
1500
1501 for (i = 0; i < vi->max_queue_pairs; i++) {
1502 u64 tpackets, tbytes, rpackets, rbytes;
1503 struct receive_queue *rq = &vi->rq[i];
1504 struct send_queue *sq = &vi->sq[i];
1505
1506 do {
1507 start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1508 tpackets = sq->stats.packets;
1509 tbytes = sq->stats.bytes;
1510 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1511
1512 do {
1513 start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1514 rpackets = rq->stats.packets;
1515 rbytes = rq->stats.bytes;
1516 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1517
1518 tot->rx_packets += rpackets;
1519 tot->tx_packets += tpackets;
1520 tot->rx_bytes += rbytes;
1521 tot->tx_bytes += tbytes;
1522 }
1523
1524 tot->tx_dropped = dev->stats.tx_dropped;
1525 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1526 tot->rx_dropped = dev->stats.rx_dropped;
1527 tot->rx_length_errors = dev->stats.rx_length_errors;
1528 tot->rx_frame_errors = dev->stats.rx_frame_errors;
1529 }
1530
1531 #ifdef CONFIG_NET_POLL_CONTROLLER
1532 static void virtnet_netpoll(struct net_device *dev)
1533 {
1534 struct virtnet_info *vi = netdev_priv(dev);
1535 int i;
1536
1537 for (i = 0; i < vi->curr_queue_pairs; i++)
1538 napi_schedule(&vi->rq[i].napi);
1539 }
1540 #endif
1541
1542 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1543 {
1544 rtnl_lock();
1545 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1546 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1547 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1548 rtnl_unlock();
1549 }
1550
1551 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1552 {
1553 struct scatterlist sg;
1554 struct net_device *dev = vi->dev;
1555
1556 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1557 return 0;
1558
1559 vi->ctrl_mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1560 sg_init_one(&sg, &vi->ctrl_mq, sizeof(vi->ctrl_mq));
1561
1562 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1563 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1564 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1565 queue_pairs);
1566 return -EINVAL;
1567 } else {
1568 vi->curr_queue_pairs = queue_pairs;
1569 /* virtnet_open() will refill when device is going to up. */
1570 if (dev->flags & IFF_UP)
1571 schedule_delayed_work(&vi->refill, 0);
1572 }
1573
1574 return 0;
1575 }
1576
1577 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1578 {
1579 int err;
1580
1581 rtnl_lock();
1582 err = _virtnet_set_queues(vi, queue_pairs);
1583 rtnl_unlock();
1584 return err;
1585 }
1586
1587 static int virtnet_close(struct net_device *dev)
1588 {
1589 struct virtnet_info *vi = netdev_priv(dev);
1590 int i;
1591
1592 /* Make sure refill_work doesn't re-enable napi! */
1593 cancel_delayed_work_sync(&vi->refill);
1594
1595 for (i = 0; i < vi->max_queue_pairs; i++) {
1596 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1597 napi_disable(&vi->rq[i].napi);
1598 virtnet_napi_tx_disable(&vi->sq[i].napi);
1599 }
1600
1601 return 0;
1602 }
1603
1604 static void virtnet_set_rx_mode(struct net_device *dev)
1605 {
1606 struct virtnet_info *vi = netdev_priv(dev);
1607 struct scatterlist sg[2];
1608 struct virtio_net_ctrl_mac *mac_data;
1609 struct netdev_hw_addr *ha;
1610 int uc_count;
1611 int mc_count;
1612 void *buf;
1613 int i;
1614
1615 /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1616 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1617 return;
1618
1619 vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1620 vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1621
1622 sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1623
1624 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1625 VIRTIO_NET_CTRL_RX_PROMISC, sg))
1626 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1627 vi->ctrl_promisc ? "en" : "dis");
1628
1629 sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1630
1631 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1632 VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1633 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1634 vi->ctrl_allmulti ? "en" : "dis");
1635
1636 uc_count = netdev_uc_count(dev);
1637 mc_count = netdev_mc_count(dev);
1638 /* MAC filter - use one buffer for both lists */
1639 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1640 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1641 mac_data = buf;
1642 if (!buf)
1643 return;
1644
1645 sg_init_table(sg, 2);
1646
1647 /* Store the unicast list and count in the front of the buffer */
1648 mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1649 i = 0;
1650 netdev_for_each_uc_addr(ha, dev)
1651 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1652
1653 sg_set_buf(&sg[0], mac_data,
1654 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1655
1656 /* multicast list and count fill the end */
1657 mac_data = (void *)&mac_data->macs[uc_count][0];
1658
1659 mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1660 i = 0;
1661 netdev_for_each_mc_addr(ha, dev)
1662 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1663
1664 sg_set_buf(&sg[1], mac_data,
1665 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1666
1667 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1668 VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1669 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1670
1671 kfree(buf);
1672 }
1673
1674 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1675 __be16 proto, u16 vid)
1676 {
1677 struct virtnet_info *vi = netdev_priv(dev);
1678 struct scatterlist sg;
1679
1680 vi->ctrl_vid = vid;
1681 sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1682
1683 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1684 VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1685 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1686 return 0;
1687 }
1688
1689 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1690 __be16 proto, u16 vid)
1691 {
1692 struct virtnet_info *vi = netdev_priv(dev);
1693 struct scatterlist sg;
1694
1695 vi->ctrl_vid = vid;
1696 sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1697
1698 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1699 VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1700 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1701 return 0;
1702 }
1703
1704 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1705 {
1706 int i;
1707
1708 if (vi->affinity_hint_set) {
1709 for (i = 0; i < vi->max_queue_pairs; i++) {
1710 virtqueue_set_affinity(vi->rq[i].vq, -1);
1711 virtqueue_set_affinity(vi->sq[i].vq, -1);
1712 }
1713
1714 vi->affinity_hint_set = false;
1715 }
1716 }
1717
1718 static void virtnet_set_affinity(struct virtnet_info *vi)
1719 {
1720 int i;
1721 int cpu;
1722
1723 /* In multiqueue mode, when the number of cpu is equal to the number of
1724 * queue pairs, we let the queue pairs to be private to one cpu by
1725 * setting the affinity hint to eliminate the contention.
1726 */
1727 if (vi->curr_queue_pairs == 1 ||
1728 vi->max_queue_pairs != num_online_cpus()) {
1729 virtnet_clean_affinity(vi, -1);
1730 return;
1731 }
1732
1733 i = 0;
1734 for_each_online_cpu(cpu) {
1735 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1736 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1737 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1738 i++;
1739 }
1740
1741 vi->affinity_hint_set = true;
1742 }
1743
1744 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1745 {
1746 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1747 node);
1748 virtnet_set_affinity(vi);
1749 return 0;
1750 }
1751
1752 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1753 {
1754 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1755 node_dead);
1756 virtnet_set_affinity(vi);
1757 return 0;
1758 }
1759
1760 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1761 {
1762 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1763 node);
1764
1765 virtnet_clean_affinity(vi, cpu);
1766 return 0;
1767 }
1768
1769 static enum cpuhp_state virtionet_online;
1770
1771 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1772 {
1773 int ret;
1774
1775 ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
1776 if (ret)
1777 return ret;
1778 ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1779 &vi->node_dead);
1780 if (!ret)
1781 return ret;
1782 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1783 return ret;
1784 }
1785
1786 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
1787 {
1788 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1789 cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1790 &vi->node_dead);
1791 }
1792
1793 static void virtnet_get_ringparam(struct net_device *dev,
1794 struct ethtool_ringparam *ring)
1795 {
1796 struct virtnet_info *vi = netdev_priv(dev);
1797
1798 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1799 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1800 ring->rx_pending = ring->rx_max_pending;
1801 ring->tx_pending = ring->tx_max_pending;
1802 }
1803
1804
1805 static void virtnet_get_drvinfo(struct net_device *dev,
1806 struct ethtool_drvinfo *info)
1807 {
1808 struct virtnet_info *vi = netdev_priv(dev);
1809 struct virtio_device *vdev = vi->vdev;
1810
1811 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1812 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1813 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1814
1815 }
1816
1817 /* TODO: Eliminate OOO packets during switching */
1818 static int virtnet_set_channels(struct net_device *dev,
1819 struct ethtool_channels *channels)
1820 {
1821 struct virtnet_info *vi = netdev_priv(dev);
1822 u16 queue_pairs = channels->combined_count;
1823 int err;
1824
1825 /* We don't support separate rx/tx channels.
1826 * We don't allow setting 'other' channels.
1827 */
1828 if (channels->rx_count || channels->tx_count || channels->other_count)
1829 return -EINVAL;
1830
1831 if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1832 return -EINVAL;
1833
1834 /* For now we don't support modifying channels while XDP is loaded
1835 * also when XDP is loaded all RX queues have XDP programs so we only
1836 * need to check a single RX queue.
1837 */
1838 if (vi->rq[0].xdp_prog)
1839 return -EINVAL;
1840
1841 get_online_cpus();
1842 err = _virtnet_set_queues(vi, queue_pairs);
1843 if (!err) {
1844 netif_set_real_num_tx_queues(dev, queue_pairs);
1845 netif_set_real_num_rx_queues(dev, queue_pairs);
1846
1847 virtnet_set_affinity(vi);
1848 }
1849 put_online_cpus();
1850
1851 return err;
1852 }
1853
1854 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1855 {
1856 struct virtnet_info *vi = netdev_priv(dev);
1857 char *p = (char *)data;
1858 unsigned int i, j;
1859
1860 switch (stringset) {
1861 case ETH_SS_STATS:
1862 for (i = 0; i < vi->curr_queue_pairs; i++) {
1863 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
1864 snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
1865 i, virtnet_rq_stats_desc[j].desc);
1866 p += ETH_GSTRING_LEN;
1867 }
1868 }
1869
1870 for (i = 0; i < vi->curr_queue_pairs; i++) {
1871 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
1872 snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
1873 i, virtnet_sq_stats_desc[j].desc);
1874 p += ETH_GSTRING_LEN;
1875 }
1876 }
1877 break;
1878 }
1879 }
1880
1881 static int virtnet_get_sset_count(struct net_device *dev, int sset)
1882 {
1883 struct virtnet_info *vi = netdev_priv(dev);
1884
1885 switch (sset) {
1886 case ETH_SS_STATS:
1887 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
1888 VIRTNET_SQ_STATS_LEN);
1889 default:
1890 return -EOPNOTSUPP;
1891 }
1892 }
1893
1894 static void virtnet_get_ethtool_stats(struct net_device *dev,
1895 struct ethtool_stats *stats, u64 *data)
1896 {
1897 struct virtnet_info *vi = netdev_priv(dev);
1898 unsigned int idx = 0, start, i, j;
1899 const u8 *stats_base;
1900 size_t offset;
1901
1902 for (i = 0; i < vi->curr_queue_pairs; i++) {
1903 struct receive_queue *rq = &vi->rq[i];
1904
1905 stats_base = (u8 *)&rq->stats;
1906 do {
1907 start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1908 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
1909 offset = virtnet_rq_stats_desc[j].offset;
1910 data[idx + j] = *(u64 *)(stats_base + offset);
1911 }
1912 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1913 idx += VIRTNET_RQ_STATS_LEN;
1914 }
1915
1916 for (i = 0; i < vi->curr_queue_pairs; i++) {
1917 struct send_queue *sq = &vi->sq[i];
1918
1919 stats_base = (u8 *)&sq->stats;
1920 do {
1921 start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1922 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
1923 offset = virtnet_sq_stats_desc[j].offset;
1924 data[idx + j] = *(u64 *)(stats_base + offset);
1925 }
1926 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1927 idx += VIRTNET_SQ_STATS_LEN;
1928 }
1929 }
1930
1931 static void virtnet_get_channels(struct net_device *dev,
1932 struct ethtool_channels *channels)
1933 {
1934 struct virtnet_info *vi = netdev_priv(dev);
1935
1936 channels->combined_count = vi->curr_queue_pairs;
1937 channels->max_combined = vi->max_queue_pairs;
1938 channels->max_other = 0;
1939 channels->rx_count = 0;
1940 channels->tx_count = 0;
1941 channels->other_count = 0;
1942 }
1943
1944 /* Check if the user is trying to change anything besides speed/duplex */
1945 static bool
1946 virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
1947 {
1948 struct ethtool_link_ksettings diff1 = *cmd;
1949 struct ethtool_link_ksettings diff2 = {};
1950
1951 /* cmd is always set so we need to clear it, validate the port type
1952 * and also without autonegotiation we can ignore advertising
1953 */
1954 diff1.base.speed = 0;
1955 diff2.base.port = PORT_OTHER;
1956 ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
1957 diff1.base.duplex = 0;
1958 diff1.base.cmd = 0;
1959 diff1.base.link_mode_masks_nwords = 0;
1960
1961 return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
1962 bitmap_empty(diff1.link_modes.supported,
1963 __ETHTOOL_LINK_MODE_MASK_NBITS) &&
1964 bitmap_empty(diff1.link_modes.advertising,
1965 __ETHTOOL_LINK_MODE_MASK_NBITS) &&
1966 bitmap_empty(diff1.link_modes.lp_advertising,
1967 __ETHTOOL_LINK_MODE_MASK_NBITS);
1968 }
1969
1970 static int virtnet_set_link_ksettings(struct net_device *dev,
1971 const struct ethtool_link_ksettings *cmd)
1972 {
1973 struct virtnet_info *vi = netdev_priv(dev);
1974 u32 speed;
1975
1976 speed = cmd->base.speed;
1977 /* don't allow custom speed and duplex */
1978 if (!ethtool_validate_speed(speed) ||
1979 !ethtool_validate_duplex(cmd->base.duplex) ||
1980 !virtnet_validate_ethtool_cmd(cmd))
1981 return -EINVAL;
1982 vi->speed = speed;
1983 vi->duplex = cmd->base.duplex;
1984
1985 return 0;
1986 }
1987
1988 static int virtnet_get_link_ksettings(struct net_device *dev,
1989 struct ethtool_link_ksettings *cmd)
1990 {
1991 struct virtnet_info *vi = netdev_priv(dev);
1992
1993 cmd->base.speed = vi->speed;
1994 cmd->base.duplex = vi->duplex;
1995 cmd->base.port = PORT_OTHER;
1996
1997 return 0;
1998 }
1999
2000 static void virtnet_init_settings(struct net_device *dev)
2001 {
2002 struct virtnet_info *vi = netdev_priv(dev);
2003
2004 vi->speed = SPEED_UNKNOWN;
2005 vi->duplex = DUPLEX_UNKNOWN;
2006 }
2007
2008 static void virtnet_update_settings(struct virtnet_info *vi)
2009 {
2010 u32 speed;
2011 u8 duplex;
2012
2013 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2014 return;
2015
2016 speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
2017 speed));
2018 if (ethtool_validate_speed(speed))
2019 vi->speed = speed;
2020 duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
2021 duplex));
2022 if (ethtool_validate_duplex(duplex))
2023 vi->duplex = duplex;
2024 }
2025
2026 static const struct ethtool_ops virtnet_ethtool_ops = {
2027 .get_drvinfo = virtnet_get_drvinfo,
2028 .get_link = ethtool_op_get_link,
2029 .get_ringparam = virtnet_get_ringparam,
2030 .get_strings = virtnet_get_strings,
2031 .get_sset_count = virtnet_get_sset_count,
2032 .get_ethtool_stats = virtnet_get_ethtool_stats,
2033 .set_channels = virtnet_set_channels,
2034 .get_channels = virtnet_get_channels,
2035 .get_ts_info = ethtool_op_get_ts_info,
2036 .get_link_ksettings = virtnet_get_link_ksettings,
2037 .set_link_ksettings = virtnet_set_link_ksettings,
2038 };
2039
2040 static void virtnet_freeze_down(struct virtio_device *vdev)
2041 {
2042 struct virtnet_info *vi = vdev->priv;
2043 int i;
2044
2045 /* Make sure no work handler is accessing the device */
2046 flush_work(&vi->config_work);
2047
2048 netif_device_detach(vi->dev);
2049 netif_tx_disable(vi->dev);
2050 cancel_delayed_work_sync(&vi->refill);
2051
2052 if (netif_running(vi->dev)) {
2053 for (i = 0; i < vi->max_queue_pairs; i++) {
2054 napi_disable(&vi->rq[i].napi);
2055 virtnet_napi_tx_disable(&vi->sq[i].napi);
2056 }
2057 }
2058 }
2059
2060 static int init_vqs(struct virtnet_info *vi);
2061
2062 static int virtnet_restore_up(struct virtio_device *vdev)
2063 {
2064 struct virtnet_info *vi = vdev->priv;
2065 int err, i;
2066
2067 err = init_vqs(vi);
2068 if (err)
2069 return err;
2070
2071 virtio_device_ready(vdev);
2072
2073 if (netif_running(vi->dev)) {
2074 for (i = 0; i < vi->curr_queue_pairs; i++)
2075 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2076 schedule_delayed_work(&vi->refill, 0);
2077
2078 for (i = 0; i < vi->max_queue_pairs; i++) {
2079 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2080 virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2081 &vi->sq[i].napi);
2082 }
2083 }
2084
2085 netif_device_attach(vi->dev);
2086 return err;
2087 }
2088
2089 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2090 {
2091 struct scatterlist sg;
2092 vi->ctrl_offloads = cpu_to_virtio64(vi->vdev, offloads);
2093
2094 sg_init_one(&sg, &vi->ctrl_offloads, sizeof(vi->ctrl_offloads));
2095
2096 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2097 VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2098 dev_warn(&vi->dev->dev, "Fail to set guest offload. \n");
2099 return -EINVAL;
2100 }
2101
2102 return 0;
2103 }
2104
2105 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2106 {
2107 u64 offloads = 0;
2108
2109 if (!vi->guest_offloads)
2110 return 0;
2111
2112 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
2113 offloads = 1ULL << VIRTIO_NET_F_GUEST_CSUM;
2114
2115 return virtnet_set_guest_offloads(vi, offloads);
2116 }
2117
2118 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2119 {
2120 u64 offloads = vi->guest_offloads;
2121
2122 if (!vi->guest_offloads)
2123 return 0;
2124 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
2125 offloads |= 1ULL << VIRTIO_NET_F_GUEST_CSUM;
2126
2127 return virtnet_set_guest_offloads(vi, offloads);
2128 }
2129
2130 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2131 struct netlink_ext_ack *extack)
2132 {
2133 unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2134 struct virtnet_info *vi = netdev_priv(dev);
2135 struct bpf_prog *old_prog;
2136 u16 xdp_qp = 0, curr_qp;
2137 int i, err;
2138
2139 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2140 && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2141 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2142 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2143 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO))) {
2144 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO, disable LRO first");
2145 return -EOPNOTSUPP;
2146 }
2147
2148 if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2149 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2150 return -EINVAL;
2151 }
2152
2153 if (dev->mtu > max_sz) {
2154 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2155 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2156 return -EINVAL;
2157 }
2158
2159 curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2160 if (prog)
2161 xdp_qp = nr_cpu_ids;
2162
2163 /* XDP requires extra queues for XDP_TX */
2164 if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2165 NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
2166 netdev_warn(dev, "request %i queues but max is %i\n",
2167 curr_qp + xdp_qp, vi->max_queue_pairs);
2168 return -ENOMEM;
2169 }
2170
2171 if (prog) {
2172 prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
2173 if (IS_ERR(prog))
2174 return PTR_ERR(prog);
2175 }
2176
2177 /* Make sure NAPI is not using any XDP TX queues for RX. */
2178 for (i = 0; i < vi->max_queue_pairs; i++)
2179 napi_disable(&vi->rq[i].napi);
2180
2181 netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2182 err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2183 if (err)
2184 goto err;
2185 vi->xdp_queue_pairs = xdp_qp;
2186
2187 for (i = 0; i < vi->max_queue_pairs; i++) {
2188 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2189 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2190 if (i == 0) {
2191 if (!old_prog)
2192 virtnet_clear_guest_offloads(vi);
2193 if (!prog)
2194 virtnet_restore_guest_offloads(vi);
2195 }
2196 if (old_prog)
2197 bpf_prog_put(old_prog);
2198 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2199 }
2200
2201 return 0;
2202
2203 err:
2204 for (i = 0; i < vi->max_queue_pairs; i++)
2205 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2206 if (prog)
2207 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2208 return err;
2209 }
2210
2211 static u32 virtnet_xdp_query(struct net_device *dev)
2212 {
2213 struct virtnet_info *vi = netdev_priv(dev);
2214 const struct bpf_prog *xdp_prog;
2215 int i;
2216
2217 for (i = 0; i < vi->max_queue_pairs; i++) {
2218 xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2219 if (xdp_prog)
2220 return xdp_prog->aux->id;
2221 }
2222 return 0;
2223 }
2224
2225 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2226 {
2227 switch (xdp->command) {
2228 case XDP_SETUP_PROG:
2229 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2230 case XDP_QUERY_PROG:
2231 xdp->prog_id = virtnet_xdp_query(dev);
2232 xdp->prog_attached = !!xdp->prog_id;
2233 return 0;
2234 default:
2235 return -EINVAL;
2236 }
2237 }
2238
2239 static const struct net_device_ops virtnet_netdev = {
2240 .ndo_open = virtnet_open,
2241 .ndo_stop = virtnet_close,
2242 .ndo_start_xmit = start_xmit,
2243 .ndo_validate_addr = eth_validate_addr,
2244 .ndo_set_mac_address = virtnet_set_mac_address,
2245 .ndo_set_rx_mode = virtnet_set_rx_mode,
2246 .ndo_get_stats64 = virtnet_stats,
2247 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2248 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2249 #ifdef CONFIG_NET_POLL_CONTROLLER
2250 .ndo_poll_controller = virtnet_netpoll,
2251 #endif
2252 .ndo_bpf = virtnet_xdp,
2253 .ndo_xdp_xmit = virtnet_xdp_xmit,
2254 .ndo_xdp_flush = virtnet_xdp_flush,
2255 .ndo_features_check = passthru_features_check,
2256 };
2257
2258 static void virtnet_config_changed_work(struct work_struct *work)
2259 {
2260 struct virtnet_info *vi =
2261 container_of(work, struct virtnet_info, config_work);
2262 u16 v;
2263
2264 if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2265 struct virtio_net_config, status, &v) < 0)
2266 return;
2267
2268 if (v & VIRTIO_NET_S_ANNOUNCE) {
2269 netdev_notify_peers(vi->dev);
2270 virtnet_ack_link_announce(vi);
2271 }
2272
2273 /* Ignore unknown (future) status bits */
2274 v &= VIRTIO_NET_S_LINK_UP;
2275
2276 if (vi->status == v)
2277 return;
2278
2279 vi->status = v;
2280
2281 if (vi->status & VIRTIO_NET_S_LINK_UP) {
2282 virtnet_update_settings(vi);
2283 netif_carrier_on(vi->dev);
2284 netif_tx_wake_all_queues(vi->dev);
2285 } else {
2286 netif_carrier_off(vi->dev);
2287 netif_tx_stop_all_queues(vi->dev);
2288 }
2289 }
2290
2291 static void virtnet_config_changed(struct virtio_device *vdev)
2292 {
2293 struct virtnet_info *vi = vdev->priv;
2294
2295 schedule_work(&vi->config_work);
2296 }
2297
2298 static void virtnet_free_queues(struct virtnet_info *vi)
2299 {
2300 int i;
2301
2302 for (i = 0; i < vi->max_queue_pairs; i++) {
2303 napi_hash_del(&vi->rq[i].napi);
2304 netif_napi_del(&vi->rq[i].napi);
2305 netif_napi_del(&vi->sq[i].napi);
2306 }
2307
2308 /* We called napi_hash_del() before netif_napi_del(),
2309 * we need to respect an RCU grace period before freeing vi->rq
2310 */
2311 synchronize_net();
2312
2313 kfree(vi->rq);
2314 kfree(vi->sq);
2315 }
2316
2317 static void _free_receive_bufs(struct virtnet_info *vi)
2318 {
2319 struct bpf_prog *old_prog;
2320 int i;
2321
2322 for (i = 0; i < vi->max_queue_pairs; i++) {
2323 while (vi->rq[i].pages)
2324 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2325
2326 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2327 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2328 if (old_prog)
2329 bpf_prog_put(old_prog);
2330 }
2331 }
2332
2333 static void free_receive_bufs(struct virtnet_info *vi)
2334 {
2335 rtnl_lock();
2336 _free_receive_bufs(vi);
2337 rtnl_unlock();
2338 }
2339
2340 static void free_receive_page_frags(struct virtnet_info *vi)
2341 {
2342 int i;
2343 for (i = 0; i < vi->max_queue_pairs; i++)
2344 if (vi->rq[i].alloc_frag.page)
2345 put_page(vi->rq[i].alloc_frag.page);
2346 }
2347
2348 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
2349 {
2350 if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
2351 return false;
2352 else if (q < vi->curr_queue_pairs)
2353 return true;
2354 else
2355 return false;
2356 }
2357
2358 static void free_unused_bufs(struct virtnet_info *vi)
2359 {
2360 void *buf;
2361 int i;
2362
2363 for (i = 0; i < vi->max_queue_pairs; i++) {
2364 struct virtqueue *vq = vi->sq[i].vq;
2365 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2366 if (!is_xdp_raw_buffer_queue(vi, i))
2367 dev_kfree_skb(buf);
2368 else
2369 put_page(virt_to_head_page(buf));
2370 }
2371 }
2372
2373 for (i = 0; i < vi->max_queue_pairs; i++) {
2374 struct virtqueue *vq = vi->rq[i].vq;
2375
2376 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2377 if (vi->mergeable_rx_bufs) {
2378 put_page(virt_to_head_page(buf));
2379 } else if (vi->big_packets) {
2380 give_pages(&vi->rq[i], buf);
2381 } else {
2382 put_page(virt_to_head_page(buf));
2383 }
2384 }
2385 }
2386 }
2387
2388 static void virtnet_del_vqs(struct virtnet_info *vi)
2389 {
2390 struct virtio_device *vdev = vi->vdev;
2391
2392 virtnet_clean_affinity(vi, -1);
2393
2394 vdev->config->del_vqs(vdev);
2395
2396 virtnet_free_queues(vi);
2397 }
2398
2399 /* How large should a single buffer be so a queue full of these can fit at
2400 * least one full packet?
2401 * Logic below assumes the mergeable buffer header is used.
2402 */
2403 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2404 {
2405 const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2406 unsigned int rq_size = virtqueue_get_vring_size(vq);
2407 unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2408 unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2409 unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2410
2411 return max(max(min_buf_len, hdr_len) - hdr_len,
2412 (unsigned int)GOOD_PACKET_LEN);
2413 }
2414
2415 static int virtnet_find_vqs(struct virtnet_info *vi)
2416 {
2417 vq_callback_t **callbacks;
2418 struct virtqueue **vqs;
2419 int ret = -ENOMEM;
2420 int i, total_vqs;
2421 const char **names;
2422 bool *ctx;
2423
2424 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2425 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2426 * possible control vq.
2427 */
2428 total_vqs = vi->max_queue_pairs * 2 +
2429 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2430
2431 /* Allocate space for find_vqs parameters */
2432 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
2433 if (!vqs)
2434 goto err_vq;
2435 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
2436 if (!callbacks)
2437 goto err_callback;
2438 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
2439 if (!names)
2440 goto err_names;
2441 if (!vi->big_packets || vi->mergeable_rx_bufs) {
2442 ctx = kzalloc(total_vqs * sizeof(*ctx), GFP_KERNEL);
2443 if (!ctx)
2444 goto err_ctx;
2445 } else {
2446 ctx = NULL;
2447 }
2448
2449 /* Parameters for control virtqueue, if any */
2450 if (vi->has_cvq) {
2451 callbacks[total_vqs - 1] = NULL;
2452 names[total_vqs - 1] = "control";
2453 }
2454
2455 /* Allocate/initialize parameters for send/receive virtqueues */
2456 for (i = 0; i < vi->max_queue_pairs; i++) {
2457 callbacks[rxq2vq(i)] = skb_recv_done;
2458 callbacks[txq2vq(i)] = skb_xmit_done;
2459 sprintf(vi->rq[i].name, "input.%d", i);
2460 sprintf(vi->sq[i].name, "output.%d", i);
2461 names[rxq2vq(i)] = vi->rq[i].name;
2462 names[txq2vq(i)] = vi->sq[i].name;
2463 if (ctx)
2464 ctx[rxq2vq(i)] = true;
2465 }
2466
2467 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2468 names, ctx, NULL);
2469 if (ret)
2470 goto err_find;
2471
2472 if (vi->has_cvq) {
2473 vi->cvq = vqs[total_vqs - 1];
2474 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2475 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2476 }
2477
2478 for (i = 0; i < vi->max_queue_pairs; i++) {
2479 vi->rq[i].vq = vqs[rxq2vq(i)];
2480 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2481 vi->sq[i].vq = vqs[txq2vq(i)];
2482 }
2483
2484 kfree(names);
2485 kfree(callbacks);
2486 kfree(vqs);
2487 kfree(ctx);
2488
2489 return 0;
2490
2491 err_find:
2492 kfree(ctx);
2493 err_ctx:
2494 kfree(names);
2495 err_names:
2496 kfree(callbacks);
2497 err_callback:
2498 kfree(vqs);
2499 err_vq:
2500 return ret;
2501 }
2502
2503 static int virtnet_alloc_queues(struct virtnet_info *vi)
2504 {
2505 int i;
2506
2507 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
2508 if (!vi->sq)
2509 goto err_sq;
2510 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
2511 if (!vi->rq)
2512 goto err_rq;
2513
2514 INIT_DELAYED_WORK(&vi->refill, refill_work);
2515 for (i = 0; i < vi->max_queue_pairs; i++) {
2516 vi->rq[i].pages = NULL;
2517 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2518 napi_weight);
2519 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2520 napi_tx ? napi_weight : 0);
2521
2522 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2523 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2524 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2525
2526 u64_stats_init(&vi->rq[i].stats.syncp);
2527 u64_stats_init(&vi->sq[i].stats.syncp);
2528 }
2529
2530 return 0;
2531
2532 err_rq:
2533 kfree(vi->sq);
2534 err_sq:
2535 return -ENOMEM;
2536 }
2537
2538 static int init_vqs(struct virtnet_info *vi)
2539 {
2540 int ret;
2541
2542 /* Allocate send & receive queues */
2543 ret = virtnet_alloc_queues(vi);
2544 if (ret)
2545 goto err;
2546
2547 ret = virtnet_find_vqs(vi);
2548 if (ret)
2549 goto err_free;
2550
2551 get_online_cpus();
2552 virtnet_set_affinity(vi);
2553 put_online_cpus();
2554
2555 return 0;
2556
2557 err_free:
2558 virtnet_free_queues(vi);
2559 err:
2560 return ret;
2561 }
2562
2563 #ifdef CONFIG_SYSFS
2564 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2565 char *buf)
2566 {
2567 struct virtnet_info *vi = netdev_priv(queue->dev);
2568 unsigned int queue_index = get_netdev_rx_queue_index(queue);
2569 struct ewma_pkt_len *avg;
2570
2571 BUG_ON(queue_index >= vi->max_queue_pairs);
2572 avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2573 return sprintf(buf, "%u\n",
2574 get_mergeable_buf_len(&vi->rq[queue_index], avg));
2575 }
2576
2577 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2578 __ATTR_RO(mergeable_rx_buffer_size);
2579
2580 static struct attribute *virtio_net_mrg_rx_attrs[] = {
2581 &mergeable_rx_buffer_size_attribute.attr,
2582 NULL
2583 };
2584
2585 static const struct attribute_group virtio_net_mrg_rx_group = {
2586 .name = "virtio_net",
2587 .attrs = virtio_net_mrg_rx_attrs
2588 };
2589 #endif
2590
2591 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2592 unsigned int fbit,
2593 const char *fname, const char *dname)
2594 {
2595 if (!virtio_has_feature(vdev, fbit))
2596 return false;
2597
2598 dev_err(&vdev->dev, "device advertises feature %s but not %s",
2599 fname, dname);
2600
2601 return true;
2602 }
2603
2604 #define VIRTNET_FAIL_ON(vdev, fbit, dbit) \
2605 virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2606
2607 static bool virtnet_validate_features(struct virtio_device *vdev)
2608 {
2609 if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2610 (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2611 "VIRTIO_NET_F_CTRL_VQ") ||
2612 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2613 "VIRTIO_NET_F_CTRL_VQ") ||
2614 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2615 "VIRTIO_NET_F_CTRL_VQ") ||
2616 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2617 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2618 "VIRTIO_NET_F_CTRL_VQ"))) {
2619 return false;
2620 }
2621
2622 return true;
2623 }
2624
2625 #define MIN_MTU ETH_MIN_MTU
2626 #define MAX_MTU ETH_MAX_MTU
2627
2628 static int virtnet_validate(struct virtio_device *vdev)
2629 {
2630 if (!vdev->config->get) {
2631 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2632 __func__);
2633 return -EINVAL;
2634 }
2635
2636 if (!virtnet_validate_features(vdev))
2637 return -EINVAL;
2638
2639 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2640 int mtu = virtio_cread16(vdev,
2641 offsetof(struct virtio_net_config,
2642 mtu));
2643 if (mtu < MIN_MTU)
2644 __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2645 }
2646
2647 return 0;
2648 }
2649
2650 static int virtnet_probe(struct virtio_device *vdev)
2651 {
2652 int i, err = -ENOMEM;
2653 struct net_device *dev;
2654 struct virtnet_info *vi;
2655 u16 max_queue_pairs;
2656 int mtu;
2657
2658 /* Find if host supports multiqueue virtio_net device */
2659 err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2660 struct virtio_net_config,
2661 max_virtqueue_pairs, &max_queue_pairs);
2662
2663 /* We need at least 2 queue's */
2664 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
2665 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
2666 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2667 max_queue_pairs = 1;
2668
2669 /* Allocate ourselves a network device with room for our info */
2670 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
2671 if (!dev)
2672 return -ENOMEM;
2673
2674 /* Set up network device as normal. */
2675 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
2676 dev->netdev_ops = &virtnet_netdev;
2677 dev->features = NETIF_F_HIGHDMA;
2678
2679 dev->ethtool_ops = &virtnet_ethtool_ops;
2680 SET_NETDEV_DEV(dev, &vdev->dev);
2681
2682 /* Do we support "hardware" checksums? */
2683 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
2684 /* This opens up the world of extra features. */
2685 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2686 if (csum)
2687 dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2688
2689 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
2690 dev->hw_features |= NETIF_F_TSO
2691 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
2692 }
2693 /* Individual feature bits: what can host handle? */
2694 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
2695 dev->hw_features |= NETIF_F_TSO;
2696 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
2697 dev->hw_features |= NETIF_F_TSO6;
2698 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
2699 dev->hw_features |= NETIF_F_TSO_ECN;
2700
2701 dev->features |= NETIF_F_GSO_ROBUST;
2702
2703 if (gso)
2704 dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
2705 /* (!csum && gso) case will be fixed by register_netdev() */
2706 }
2707 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
2708 dev->features |= NETIF_F_RXCSUM;
2709
2710 dev->vlan_features = dev->features;
2711
2712 /* MTU range: 68 - 65535 */
2713 dev->min_mtu = MIN_MTU;
2714 dev->max_mtu = MAX_MTU;
2715
2716 /* Configuration may specify what MAC to use. Otherwise random. */
2717 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
2718 virtio_cread_bytes(vdev,
2719 offsetof(struct virtio_net_config, mac),
2720 dev->dev_addr, dev->addr_len);
2721 else
2722 eth_hw_addr_random(dev);
2723
2724 /* Set up our device-specific information */
2725 vi = netdev_priv(dev);
2726 vi->dev = dev;
2727 vi->vdev = vdev;
2728 vdev->priv = vi;
2729
2730 INIT_WORK(&vi->config_work, virtnet_config_changed_work);
2731
2732 /* If we can receive ANY GSO packets, we must allocate large ones. */
2733 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2734 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2735 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
2736 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
2737 vi->big_packets = true;
2738
2739 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
2740 vi->mergeable_rx_bufs = true;
2741
2742 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
2743 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2744 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2745 else
2746 vi->hdr_len = sizeof(struct virtio_net_hdr);
2747
2748 if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
2749 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2750 vi->any_header_sg = true;
2751
2752 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2753 vi->has_cvq = true;
2754
2755 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2756 mtu = virtio_cread16(vdev,
2757 offsetof(struct virtio_net_config,
2758 mtu));
2759 if (mtu < dev->min_mtu) {
2760 /* Should never trigger: MTU was previously validated
2761 * in virtnet_validate.
2762 */
2763 dev_err(&vdev->dev, "device MTU appears to have changed "
2764 "it is now %d < %d", mtu, dev->min_mtu);
2765 goto free;
2766 }
2767
2768 dev->mtu = mtu;
2769 dev->max_mtu = mtu;
2770
2771 /* TODO: size buffers correctly in this case. */
2772 if (dev->mtu > ETH_DATA_LEN)
2773 vi->big_packets = true;
2774 }
2775
2776 if (vi->any_header_sg)
2777 dev->needed_headroom = vi->hdr_len;
2778
2779 /* Enable multiqueue by default */
2780 if (num_online_cpus() >= max_queue_pairs)
2781 vi->curr_queue_pairs = max_queue_pairs;
2782 else
2783 vi->curr_queue_pairs = num_online_cpus();
2784 vi->max_queue_pairs = max_queue_pairs;
2785
2786 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
2787 err = init_vqs(vi);
2788 if (err)
2789 goto free;
2790
2791 #ifdef CONFIG_SYSFS
2792 if (vi->mergeable_rx_bufs)
2793 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
2794 #endif
2795 netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
2796 netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
2797
2798 virtnet_init_settings(dev);
2799
2800 err = register_netdev(dev);
2801 if (err) {
2802 pr_debug("virtio_net: registering device failed\n");
2803 goto free_vqs;
2804 }
2805
2806 virtio_device_ready(vdev);
2807
2808 err = virtnet_cpu_notif_add(vi);
2809 if (err) {
2810 pr_debug("virtio_net: registering cpu notifier failed\n");
2811 goto free_unregister_netdev;
2812 }
2813
2814 virtnet_set_queues(vi, vi->curr_queue_pairs);
2815
2816 /* Assume link up if device can't report link status,
2817 otherwise get link status from config. */
2818 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
2819 netif_carrier_off(dev);
2820 schedule_work(&vi->config_work);
2821 } else {
2822 vi->status = VIRTIO_NET_S_LINK_UP;
2823 virtnet_update_settings(vi);
2824 netif_carrier_on(dev);
2825 }
2826
2827 for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
2828 if (virtio_has_feature(vi->vdev, guest_offloads[i]))
2829 set_bit(guest_offloads[i], &vi->guest_offloads);
2830
2831 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
2832 dev->name, max_queue_pairs);
2833
2834 return 0;
2835
2836 free_unregister_netdev:
2837 vi->vdev->config->reset(vdev);
2838
2839 unregister_netdev(dev);
2840 free_vqs:
2841 cancel_delayed_work_sync(&vi->refill);
2842 free_receive_page_frags(vi);
2843 virtnet_del_vqs(vi);
2844 free:
2845 free_netdev(dev);
2846 return err;
2847 }
2848
2849 static void remove_vq_common(struct virtnet_info *vi)
2850 {
2851 vi->vdev->config->reset(vi->vdev);
2852
2853 /* Free unused buffers in both send and recv, if any. */
2854 free_unused_bufs(vi);
2855
2856 free_receive_bufs(vi);
2857
2858 free_receive_page_frags(vi);
2859
2860 virtnet_del_vqs(vi);
2861 }
2862
2863 static void virtnet_remove(struct virtio_device *vdev)
2864 {
2865 struct virtnet_info *vi = vdev->priv;
2866
2867 virtnet_cpu_notif_remove(vi);
2868
2869 /* Make sure no work handler is accessing the device. */
2870 flush_work(&vi->config_work);
2871
2872 unregister_netdev(vi->dev);
2873
2874 remove_vq_common(vi);
2875
2876 free_netdev(vi->dev);
2877 }
2878
2879 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
2880 {
2881 struct virtnet_info *vi = vdev->priv;
2882
2883 virtnet_cpu_notif_remove(vi);
2884 virtnet_freeze_down(vdev);
2885 remove_vq_common(vi);
2886
2887 return 0;
2888 }
2889
2890 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
2891 {
2892 struct virtnet_info *vi = vdev->priv;
2893 int err;
2894
2895 err = virtnet_restore_up(vdev);
2896 if (err)
2897 return err;
2898 virtnet_set_queues(vi, vi->curr_queue_pairs);
2899
2900 err = virtnet_cpu_notif_add(vi);
2901 if (err)
2902 return err;
2903
2904 return 0;
2905 }
2906
2907 static struct virtio_device_id id_table[] = {
2908 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2909 { 0 },
2910 };
2911
2912 #define VIRTNET_FEATURES \
2913 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
2914 VIRTIO_NET_F_MAC, \
2915 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
2916 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
2917 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
2918 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
2919 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
2920 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
2921 VIRTIO_NET_F_CTRL_MAC_ADDR, \
2922 VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
2923 VIRTIO_NET_F_SPEED_DUPLEX
2924
2925 static unsigned int features[] = {
2926 VIRTNET_FEATURES,
2927 };
2928
2929 static unsigned int features_legacy[] = {
2930 VIRTNET_FEATURES,
2931 VIRTIO_NET_F_GSO,
2932 VIRTIO_F_ANY_LAYOUT,
2933 };
2934
2935 static struct virtio_driver virtio_net_driver = {
2936 .feature_table = features,
2937 .feature_table_size = ARRAY_SIZE(features),
2938 .feature_table_legacy = features_legacy,
2939 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
2940 .driver.name = KBUILD_MODNAME,
2941 .driver.owner = THIS_MODULE,
2942 .id_table = id_table,
2943 .validate = virtnet_validate,
2944 .probe = virtnet_probe,
2945 .remove = virtnet_remove,
2946 .config_changed = virtnet_config_changed,
2947 #ifdef CONFIG_PM_SLEEP
2948 .freeze = virtnet_freeze,
2949 .restore = virtnet_restore,
2950 #endif
2951 };
2952
2953 static __init int virtio_net_driver_init(void)
2954 {
2955 int ret;
2956
2957 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
2958 virtnet_cpu_online,
2959 virtnet_cpu_down_prep);
2960 if (ret < 0)
2961 goto out;
2962 virtionet_online = ret;
2963 ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
2964 NULL, virtnet_cpu_dead);
2965 if (ret)
2966 goto err_dead;
2967
2968 ret = register_virtio_driver(&virtio_net_driver);
2969 if (ret)
2970 goto err_virtio;
2971 return 0;
2972 err_virtio:
2973 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2974 err_dead:
2975 cpuhp_remove_multi_state(virtionet_online);
2976 out:
2977 return ret;
2978 }
2979 module_init(virtio_net_driver_init);
2980
2981 static __exit void virtio_net_driver_exit(void)
2982 {
2983 unregister_virtio_driver(&virtio_net_driver);
2984 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2985 cpuhp_remove_multi_state(virtionet_online);
2986 }
2987 module_exit(virtio_net_driver_exit);
2988
2989 MODULE_DEVICE_TABLE(virtio, id_table);
2990 MODULE_DESCRIPTION("Virtio network driver");
2991 MODULE_LICENSE("GPL");
CRIS linux kernel tree