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