virtio_net: multiqueue support
[deliverable/linux.git] / drivers / net / virtio_net.c
1 /* A network driver using virtio.
2 *
3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 //#define DEBUG
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/ethtool.h>
23 #include <linux/module.h>
24 #include <linux/virtio.h>
25 #include <linux/virtio_net.h>
26 #include <linux/scatterlist.h>
27 #include <linux/if_vlan.h>
28 #include <linux/slab.h>
29
30 static int napi_weight = 128;
31 module_param(napi_weight, int, 0444);
32
33 static bool csum = true, gso = true;
34 module_param(csum, bool, 0444);
35 module_param(gso, bool, 0444);
36
37 /* FIXME: MTU in config. */
38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
39 #define GOOD_COPY_LEN 128
40
41 #define VIRTNET_SEND_COMMAND_SG_MAX 2
42 #define VIRTNET_DRIVER_VERSION "1.0.0"
43
44 struct virtnet_stats {
45 struct u64_stats_sync tx_syncp;
46 struct u64_stats_sync rx_syncp;
47 u64 tx_bytes;
48 u64 tx_packets;
49
50 u64 rx_bytes;
51 u64 rx_packets;
52 };
53
54 /* Internal representation of a send virtqueue */
55 struct send_queue {
56 /* Virtqueue associated with this send _queue */
57 struct virtqueue *vq;
58
59 /* TX: fragments + linear part + virtio header */
60 struct scatterlist sg[MAX_SKB_FRAGS + 2];
61
62 /* Name of the send queue: output.$index */
63 char name[40];
64 };
65
66 /* Internal representation of a receive virtqueue */
67 struct receive_queue {
68 /* Virtqueue associated with this receive_queue */
69 struct virtqueue *vq;
70
71 struct napi_struct napi;
72
73 /* Number of input buffers, and max we've ever had. */
74 unsigned int num, max;
75
76 /* Chain pages by the private ptr. */
77 struct page *pages;
78
79 /* RX: fragments + linear part + virtio header */
80 struct scatterlist sg[MAX_SKB_FRAGS + 2];
81
82 /* Name of this receive queue: input.$index */
83 char name[40];
84 };
85
86 struct virtnet_info {
87 struct virtio_device *vdev;
88 struct virtqueue *cvq;
89 struct net_device *dev;
90 struct send_queue *sq;
91 struct receive_queue *rq;
92 unsigned int status;
93
94 /* Max # of queue pairs supported by the device */
95 u16 max_queue_pairs;
96
97 /* # of queue pairs currently used by the driver */
98 u16 curr_queue_pairs;
99
100 /* I like... big packets and I cannot lie! */
101 bool big_packets;
102
103 /* Host will merge rx buffers for big packets (shake it! shake it!) */
104 bool mergeable_rx_bufs;
105
106 /* Has control virtqueue */
107 bool has_cvq;
108
109 /* enable config space updates */
110 bool config_enable;
111
112 /* Active statistics */
113 struct virtnet_stats __percpu *stats;
114
115 /* Work struct for refilling if we run low on memory. */
116 struct delayed_work refill;
117
118 /* Work struct for config space updates */
119 struct work_struct config_work;
120
121 /* Lock for config space updates */
122 struct mutex config_lock;
123
124 /* Does the affinity hint is set for virtqueues? */
125 bool affinity_hint_set;
126 };
127
128 struct skb_vnet_hdr {
129 union {
130 struct virtio_net_hdr hdr;
131 struct virtio_net_hdr_mrg_rxbuf mhdr;
132 };
133 unsigned int num_sg;
134 };
135
136 struct padded_vnet_hdr {
137 struct virtio_net_hdr hdr;
138 /*
139 * virtio_net_hdr should be in a separated sg buffer because of a
140 * QEMU bug, and data sg buffer shares same page with this header sg.
141 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
142 */
143 char padding[6];
144 };
145
146 /* Converting between virtqueue no. and kernel tx/rx queue no.
147 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
148 */
149 static int vq2txq(struct virtqueue *vq)
150 {
151 return (virtqueue_get_queue_index(vq) - 1) / 2;
152 }
153
154 static int txq2vq(int txq)
155 {
156 return txq * 2 + 1;
157 }
158
159 static int vq2rxq(struct virtqueue *vq)
160 {
161 return virtqueue_get_queue_index(vq) / 2;
162 }
163
164 static int rxq2vq(int rxq)
165 {
166 return rxq * 2;
167 }
168
169 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
170 {
171 return (struct skb_vnet_hdr *)skb->cb;
172 }
173
174 /*
175 * private is used to chain pages for big packets, put the whole
176 * most recent used list in the beginning for reuse
177 */
178 static void give_pages(struct receive_queue *rq, struct page *page)
179 {
180 struct page *end;
181
182 /* Find end of list, sew whole thing into vi->rq.pages. */
183 for (end = page; end->private; end = (struct page *)end->private);
184 end->private = (unsigned long)rq->pages;
185 rq->pages = page;
186 }
187
188 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
189 {
190 struct page *p = rq->pages;
191
192 if (p) {
193 rq->pages = (struct page *)p->private;
194 /* clear private here, it is used to chain pages */
195 p->private = 0;
196 } else
197 p = alloc_page(gfp_mask);
198 return p;
199 }
200
201 static void skb_xmit_done(struct virtqueue *vq)
202 {
203 struct virtnet_info *vi = vq->vdev->priv;
204
205 /* Suppress further interrupts. */
206 virtqueue_disable_cb(vq);
207
208 /* We were probably waiting for more output buffers. */
209 netif_wake_subqueue(vi->dev, vq2txq(vq));
210 }
211
212 static void set_skb_frag(struct sk_buff *skb, struct page *page,
213 unsigned int offset, unsigned int *len)
214 {
215 int size = min((unsigned)PAGE_SIZE - offset, *len);
216 int i = skb_shinfo(skb)->nr_frags;
217
218 __skb_fill_page_desc(skb, i, page, offset, size);
219
220 skb->data_len += size;
221 skb->len += size;
222 skb->truesize += PAGE_SIZE;
223 skb_shinfo(skb)->nr_frags++;
224 *len -= size;
225 }
226
227 /* Called from bottom half context */
228 static struct sk_buff *page_to_skb(struct receive_queue *rq,
229 struct page *page, unsigned int len)
230 {
231 struct virtnet_info *vi = rq->vq->vdev->priv;
232 struct sk_buff *skb;
233 struct skb_vnet_hdr *hdr;
234 unsigned int copy, hdr_len, offset;
235 char *p;
236
237 p = page_address(page);
238
239 /* copy small packet so we can reuse these pages for small data */
240 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
241 if (unlikely(!skb))
242 return NULL;
243
244 hdr = skb_vnet_hdr(skb);
245
246 if (vi->mergeable_rx_bufs) {
247 hdr_len = sizeof hdr->mhdr;
248 offset = hdr_len;
249 } else {
250 hdr_len = sizeof hdr->hdr;
251 offset = sizeof(struct padded_vnet_hdr);
252 }
253
254 memcpy(hdr, p, hdr_len);
255
256 len -= hdr_len;
257 p += offset;
258
259 copy = len;
260 if (copy > skb_tailroom(skb))
261 copy = skb_tailroom(skb);
262 memcpy(skb_put(skb, copy), p, copy);
263
264 len -= copy;
265 offset += copy;
266
267 /*
268 * Verify that we can indeed put this data into a skb.
269 * This is here to handle cases when the device erroneously
270 * tries to receive more than is possible. This is usually
271 * the case of a broken device.
272 */
273 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
274 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
275 dev_kfree_skb(skb);
276 return NULL;
277 }
278
279 while (len) {
280 set_skb_frag(skb, page, offset, &len);
281 page = (struct page *)page->private;
282 offset = 0;
283 }
284
285 if (page)
286 give_pages(rq, page);
287
288 return skb;
289 }
290
291 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
292 {
293 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
294 struct page *page;
295 int num_buf, i, len;
296
297 num_buf = hdr->mhdr.num_buffers;
298 while (--num_buf) {
299 i = skb_shinfo(skb)->nr_frags;
300 if (i >= MAX_SKB_FRAGS) {
301 pr_debug("%s: packet too long\n", skb->dev->name);
302 skb->dev->stats.rx_length_errors++;
303 return -EINVAL;
304 }
305 page = virtqueue_get_buf(rq->vq, &len);
306 if (!page) {
307 pr_debug("%s: rx error: %d buffers missing\n",
308 skb->dev->name, hdr->mhdr.num_buffers);
309 skb->dev->stats.rx_length_errors++;
310 return -EINVAL;
311 }
312
313 if (len > PAGE_SIZE)
314 len = PAGE_SIZE;
315
316 set_skb_frag(skb, page, 0, &len);
317
318 --rq->num;
319 }
320 return 0;
321 }
322
323 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
324 {
325 struct virtnet_info *vi = rq->vq->vdev->priv;
326 struct net_device *dev = vi->dev;
327 struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
328 struct sk_buff *skb;
329 struct page *page;
330 struct skb_vnet_hdr *hdr;
331
332 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
333 pr_debug("%s: short packet %i\n", dev->name, len);
334 dev->stats.rx_length_errors++;
335 if (vi->mergeable_rx_bufs || vi->big_packets)
336 give_pages(rq, buf);
337 else
338 dev_kfree_skb(buf);
339 return;
340 }
341
342 if (!vi->mergeable_rx_bufs && !vi->big_packets) {
343 skb = buf;
344 len -= sizeof(struct virtio_net_hdr);
345 skb_trim(skb, len);
346 } else {
347 page = buf;
348 skb = page_to_skb(rq, page, len);
349 if (unlikely(!skb)) {
350 dev->stats.rx_dropped++;
351 give_pages(rq, page);
352 return;
353 }
354 if (vi->mergeable_rx_bufs)
355 if (receive_mergeable(rq, skb)) {
356 dev_kfree_skb(skb);
357 return;
358 }
359 }
360
361 hdr = skb_vnet_hdr(skb);
362
363 u64_stats_update_begin(&stats->rx_syncp);
364 stats->rx_bytes += skb->len;
365 stats->rx_packets++;
366 u64_stats_update_end(&stats->rx_syncp);
367
368 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
369 pr_debug("Needs csum!\n");
370 if (!skb_partial_csum_set(skb,
371 hdr->hdr.csum_start,
372 hdr->hdr.csum_offset))
373 goto frame_err;
374 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
375 skb->ip_summed = CHECKSUM_UNNECESSARY;
376 }
377
378 skb->protocol = eth_type_trans(skb, dev);
379 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
380 ntohs(skb->protocol), skb->len, skb->pkt_type);
381
382 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
383 pr_debug("GSO!\n");
384 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
385 case VIRTIO_NET_HDR_GSO_TCPV4:
386 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
387 break;
388 case VIRTIO_NET_HDR_GSO_UDP:
389 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
390 break;
391 case VIRTIO_NET_HDR_GSO_TCPV6:
392 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
393 break;
394 default:
395 net_warn_ratelimited("%s: bad gso type %u.\n",
396 dev->name, hdr->hdr.gso_type);
397 goto frame_err;
398 }
399
400 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
401 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
402
403 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
404 if (skb_shinfo(skb)->gso_size == 0) {
405 net_warn_ratelimited("%s: zero gso size.\n", dev->name);
406 goto frame_err;
407 }
408
409 /* Header must be checked, and gso_segs computed. */
410 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
411 skb_shinfo(skb)->gso_segs = 0;
412 }
413
414 netif_receive_skb(skb);
415 return;
416
417 frame_err:
418 dev->stats.rx_frame_errors++;
419 dev_kfree_skb(skb);
420 }
421
422 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
423 {
424 struct virtnet_info *vi = rq->vq->vdev->priv;
425 struct sk_buff *skb;
426 struct skb_vnet_hdr *hdr;
427 int err;
428
429 skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
430 if (unlikely(!skb))
431 return -ENOMEM;
432
433 skb_put(skb, MAX_PACKET_LEN);
434
435 hdr = skb_vnet_hdr(skb);
436 sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
437
438 skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
439
440 err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp);
441 if (err < 0)
442 dev_kfree_skb(skb);
443
444 return err;
445 }
446
447 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
448 {
449 struct page *first, *list = NULL;
450 char *p;
451 int i, err, offset;
452
453 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
454 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
455 first = get_a_page(rq, gfp);
456 if (!first) {
457 if (list)
458 give_pages(rq, list);
459 return -ENOMEM;
460 }
461 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
462
463 /* chain new page in list head to match sg */
464 first->private = (unsigned long)list;
465 list = first;
466 }
467
468 first = get_a_page(rq, gfp);
469 if (!first) {
470 give_pages(rq, list);
471 return -ENOMEM;
472 }
473 p = page_address(first);
474
475 /* rq->sg[0], rq->sg[1] share the same page */
476 /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
477 sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
478
479 /* rq->sg[1] for data packet, from offset */
480 offset = sizeof(struct padded_vnet_hdr);
481 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
482
483 /* chain first in list head */
484 first->private = (unsigned long)list;
485 err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2,
486 first, gfp);
487 if (err < 0)
488 give_pages(rq, first);
489
490 return err;
491 }
492
493 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
494 {
495 struct page *page;
496 int err;
497
498 page = get_a_page(rq, gfp);
499 if (!page)
500 return -ENOMEM;
501
502 sg_init_one(rq->sg, page_address(page), PAGE_SIZE);
503
504 err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp);
505 if (err < 0)
506 give_pages(rq, page);
507
508 return err;
509 }
510
511 /*
512 * Returns false if we couldn't fill entirely (OOM).
513 *
514 * Normally run in the receive path, but can also be run from ndo_open
515 * before we're receiving packets, or from refill_work which is
516 * careful to disable receiving (using napi_disable).
517 */
518 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
519 {
520 struct virtnet_info *vi = rq->vq->vdev->priv;
521 int err;
522 bool oom;
523
524 do {
525 if (vi->mergeable_rx_bufs)
526 err = add_recvbuf_mergeable(rq, gfp);
527 else if (vi->big_packets)
528 err = add_recvbuf_big(rq, gfp);
529 else
530 err = add_recvbuf_small(rq, gfp);
531
532 oom = err == -ENOMEM;
533 if (err < 0)
534 break;
535 ++rq->num;
536 } while (err > 0);
537 if (unlikely(rq->num > rq->max))
538 rq->max = rq->num;
539 virtqueue_kick(rq->vq);
540 return !oom;
541 }
542
543 static void skb_recv_done(struct virtqueue *rvq)
544 {
545 struct virtnet_info *vi = rvq->vdev->priv;
546 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
547
548 /* Schedule NAPI, Suppress further interrupts if successful. */
549 if (napi_schedule_prep(&rq->napi)) {
550 virtqueue_disable_cb(rvq);
551 __napi_schedule(&rq->napi);
552 }
553 }
554
555 static void virtnet_napi_enable(struct receive_queue *rq)
556 {
557 napi_enable(&rq->napi);
558
559 /* If all buffers were filled by other side before we napi_enabled, we
560 * won't get another interrupt, so process any outstanding packets
561 * now. virtnet_poll wants re-enable the queue, so we disable here.
562 * We synchronize against interrupts via NAPI_STATE_SCHED */
563 if (napi_schedule_prep(&rq->napi)) {
564 virtqueue_disable_cb(rq->vq);
565 local_bh_disable();
566 __napi_schedule(&rq->napi);
567 local_bh_enable();
568 }
569 }
570
571 static void refill_work(struct work_struct *work)
572 {
573 struct virtnet_info *vi =
574 container_of(work, struct virtnet_info, refill.work);
575 bool still_empty;
576 int i;
577
578 for (i = 0; i < vi->max_queue_pairs; i++) {
579 struct receive_queue *rq = &vi->rq[i];
580
581 napi_disable(&rq->napi);
582 still_empty = !try_fill_recv(rq, GFP_KERNEL);
583 virtnet_napi_enable(rq);
584
585 /* In theory, this can happen: if we don't get any buffers in
586 * we will *never* try to fill again.
587 */
588 if (still_empty)
589 schedule_delayed_work(&vi->refill, HZ/2);
590 }
591 }
592
593 static int virtnet_poll(struct napi_struct *napi, int budget)
594 {
595 struct receive_queue *rq =
596 container_of(napi, struct receive_queue, napi);
597 struct virtnet_info *vi = rq->vq->vdev->priv;
598 void *buf;
599 unsigned int len, received = 0;
600
601 again:
602 while (received < budget &&
603 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
604 receive_buf(rq, buf, len);
605 --rq->num;
606 received++;
607 }
608
609 if (rq->num < rq->max / 2) {
610 if (!try_fill_recv(rq, GFP_ATOMIC))
611 schedule_delayed_work(&vi->refill, 0);
612 }
613
614 /* Out of packets? */
615 if (received < budget) {
616 napi_complete(napi);
617 if (unlikely(!virtqueue_enable_cb(rq->vq)) &&
618 napi_schedule_prep(napi)) {
619 virtqueue_disable_cb(rq->vq);
620 __napi_schedule(napi);
621 goto again;
622 }
623 }
624
625 return received;
626 }
627
628 static int virtnet_open(struct net_device *dev)
629 {
630 struct virtnet_info *vi = netdev_priv(dev);
631 int i;
632
633 for (i = 0; i < vi->max_queue_pairs; i++) {
634 /* Make sure we have some buffers: if oom use wq. */
635 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
636 schedule_delayed_work(&vi->refill, 0);
637 virtnet_napi_enable(&vi->rq[i]);
638 }
639
640 return 0;
641 }
642
643 static unsigned int free_old_xmit_skbs(struct send_queue *sq)
644 {
645 struct sk_buff *skb;
646 unsigned int len, tot_sgs = 0;
647 struct virtnet_info *vi = sq->vq->vdev->priv;
648 struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
649
650 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
651 pr_debug("Sent skb %p\n", skb);
652
653 u64_stats_update_begin(&stats->tx_syncp);
654 stats->tx_bytes += skb->len;
655 stats->tx_packets++;
656 u64_stats_update_end(&stats->tx_syncp);
657
658 tot_sgs += skb_vnet_hdr(skb)->num_sg;
659 dev_kfree_skb_any(skb);
660 }
661 return tot_sgs;
662 }
663
664 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
665 {
666 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
667 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
668 struct virtnet_info *vi = sq->vq->vdev->priv;
669
670 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
671
672 if (skb->ip_summed == CHECKSUM_PARTIAL) {
673 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
674 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
675 hdr->hdr.csum_offset = skb->csum_offset;
676 } else {
677 hdr->hdr.flags = 0;
678 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
679 }
680
681 if (skb_is_gso(skb)) {
682 hdr->hdr.hdr_len = skb_headlen(skb);
683 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
684 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
685 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
686 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
687 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
688 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
689 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
690 else
691 BUG();
692 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
693 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
694 } else {
695 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
696 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
697 }
698
699 hdr->mhdr.num_buffers = 0;
700
701 /* Encode metadata header at front. */
702 if (vi->mergeable_rx_bufs)
703 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
704 else
705 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
706
707 hdr->num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
708 return virtqueue_add_buf(sq->vq, sq->sg, hdr->num_sg,
709 0, skb, GFP_ATOMIC);
710 }
711
712 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
713 {
714 struct virtnet_info *vi = netdev_priv(dev);
715 int qnum = skb_get_queue_mapping(skb);
716 struct send_queue *sq = &vi->sq[qnum];
717 int capacity;
718
719 /* Free up any pending old buffers before queueing new ones. */
720 free_old_xmit_skbs(sq);
721
722 /* Try to transmit */
723 capacity = xmit_skb(sq, skb);
724
725 /* This can happen with OOM and indirect buffers. */
726 if (unlikely(capacity < 0)) {
727 if (likely(capacity == -ENOMEM)) {
728 if (net_ratelimit())
729 dev_warn(&dev->dev,
730 "TXQ (%d) failure: out of memory\n",
731 qnum);
732 } else {
733 dev->stats.tx_fifo_errors++;
734 if (net_ratelimit())
735 dev_warn(&dev->dev,
736 "Unexpected TXQ (%d) failure: %d\n",
737 qnum, capacity);
738 }
739 dev->stats.tx_dropped++;
740 kfree_skb(skb);
741 return NETDEV_TX_OK;
742 }
743 virtqueue_kick(sq->vq);
744
745 /* Don't wait up for transmitted skbs to be freed. */
746 skb_orphan(skb);
747 nf_reset(skb);
748
749 /* Apparently nice girls don't return TX_BUSY; stop the queue
750 * before it gets out of hand. Naturally, this wastes entries. */
751 if (capacity < 2+MAX_SKB_FRAGS) {
752 netif_stop_subqueue(dev, qnum);
753 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
754 /* More just got used, free them then recheck. */
755 capacity += free_old_xmit_skbs(sq);
756 if (capacity >= 2+MAX_SKB_FRAGS) {
757 netif_start_subqueue(dev, qnum);
758 virtqueue_disable_cb(sq->vq);
759 }
760 }
761 }
762
763 return NETDEV_TX_OK;
764 }
765
766 static int virtnet_set_mac_address(struct net_device *dev, void *p)
767 {
768 struct virtnet_info *vi = netdev_priv(dev);
769 struct virtio_device *vdev = vi->vdev;
770 int ret;
771
772 ret = eth_mac_addr(dev, p);
773 if (ret)
774 return ret;
775
776 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
777 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
778 dev->dev_addr, dev->addr_len);
779
780 return 0;
781 }
782
783 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
784 struct rtnl_link_stats64 *tot)
785 {
786 struct virtnet_info *vi = netdev_priv(dev);
787 int cpu;
788 unsigned int start;
789
790 for_each_possible_cpu(cpu) {
791 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
792 u64 tpackets, tbytes, rpackets, rbytes;
793
794 do {
795 start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
796 tpackets = stats->tx_packets;
797 tbytes = stats->tx_bytes;
798 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
799
800 do {
801 start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
802 rpackets = stats->rx_packets;
803 rbytes = stats->rx_bytes;
804 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
805
806 tot->rx_packets += rpackets;
807 tot->tx_packets += tpackets;
808 tot->rx_bytes += rbytes;
809 tot->tx_bytes += tbytes;
810 }
811
812 tot->tx_dropped = dev->stats.tx_dropped;
813 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
814 tot->rx_dropped = dev->stats.rx_dropped;
815 tot->rx_length_errors = dev->stats.rx_length_errors;
816 tot->rx_frame_errors = dev->stats.rx_frame_errors;
817
818 return tot;
819 }
820
821 #ifdef CONFIG_NET_POLL_CONTROLLER
822 static void virtnet_netpoll(struct net_device *dev)
823 {
824 struct virtnet_info *vi = netdev_priv(dev);
825 int i;
826
827 for (i = 0; i < vi->curr_queue_pairs; i++)
828 napi_schedule(&vi->rq[i].napi);
829 }
830 #endif
831
832 /*
833 * Send command via the control virtqueue and check status. Commands
834 * supported by the hypervisor, as indicated by feature bits, should
835 * never fail unless improperly formated.
836 */
837 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
838 struct scatterlist *data, int out, int in)
839 {
840 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
841 struct virtio_net_ctrl_hdr ctrl;
842 virtio_net_ctrl_ack status = ~0;
843 unsigned int tmp;
844 int i;
845
846 /* Caller should know better */
847 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
848 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
849
850 out++; /* Add header */
851 in++; /* Add return status */
852
853 ctrl.class = class;
854 ctrl.cmd = cmd;
855
856 sg_init_table(sg, out + in);
857
858 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
859 for_each_sg(data, s, out + in - 2, i)
860 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
861 sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
862
863 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
864
865 virtqueue_kick(vi->cvq);
866
867 /*
868 * Spin for a response, the kick causes an ioport write, trapping
869 * into the hypervisor, so the request should be handled immediately.
870 */
871 while (!virtqueue_get_buf(vi->cvq, &tmp))
872 cpu_relax();
873
874 return status == VIRTIO_NET_OK;
875 }
876
877 static void virtnet_ack_link_announce(struct virtnet_info *vi)
878 {
879 rtnl_lock();
880 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
881 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
882 0, 0))
883 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
884 rtnl_unlock();
885 }
886
887 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
888 {
889 struct scatterlist sg;
890 struct virtio_net_ctrl_mq s;
891 struct net_device *dev = vi->dev;
892
893 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
894 return 0;
895
896 s.virtqueue_pairs = queue_pairs;
897 sg_init_one(&sg, &s, sizeof(s));
898
899 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
900 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){
901 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
902 queue_pairs);
903 return -EINVAL;
904 } else
905 vi->curr_queue_pairs = queue_pairs;
906
907 return 0;
908 }
909
910 static int virtnet_close(struct net_device *dev)
911 {
912 struct virtnet_info *vi = netdev_priv(dev);
913 int i;
914
915 /* Make sure refill_work doesn't re-enable napi! */
916 cancel_delayed_work_sync(&vi->refill);
917
918 for (i = 0; i < vi->max_queue_pairs; i++)
919 napi_disable(&vi->rq[i].napi);
920
921 return 0;
922 }
923
924 static void virtnet_set_rx_mode(struct net_device *dev)
925 {
926 struct virtnet_info *vi = netdev_priv(dev);
927 struct scatterlist sg[2];
928 u8 promisc, allmulti;
929 struct virtio_net_ctrl_mac *mac_data;
930 struct netdev_hw_addr *ha;
931 int uc_count;
932 int mc_count;
933 void *buf;
934 int i;
935
936 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
937 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
938 return;
939
940 promisc = ((dev->flags & IFF_PROMISC) != 0);
941 allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
942
943 sg_init_one(sg, &promisc, sizeof(promisc));
944
945 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
946 VIRTIO_NET_CTRL_RX_PROMISC,
947 sg, 1, 0))
948 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
949 promisc ? "en" : "dis");
950
951 sg_init_one(sg, &allmulti, sizeof(allmulti));
952
953 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
954 VIRTIO_NET_CTRL_RX_ALLMULTI,
955 sg, 1, 0))
956 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
957 allmulti ? "en" : "dis");
958
959 uc_count = netdev_uc_count(dev);
960 mc_count = netdev_mc_count(dev);
961 /* MAC filter - use one buffer for both lists */
962 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
963 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
964 mac_data = buf;
965 if (!buf) {
966 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
967 return;
968 }
969
970 sg_init_table(sg, 2);
971
972 /* Store the unicast list and count in the front of the buffer */
973 mac_data->entries = uc_count;
974 i = 0;
975 netdev_for_each_uc_addr(ha, dev)
976 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
977
978 sg_set_buf(&sg[0], mac_data,
979 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
980
981 /* multicast list and count fill the end */
982 mac_data = (void *)&mac_data->macs[uc_count][0];
983
984 mac_data->entries = mc_count;
985 i = 0;
986 netdev_for_each_mc_addr(ha, dev)
987 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
988
989 sg_set_buf(&sg[1], mac_data,
990 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
991
992 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
993 VIRTIO_NET_CTRL_MAC_TABLE_SET,
994 sg, 2, 0))
995 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
996
997 kfree(buf);
998 }
999
1000 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
1001 {
1002 struct virtnet_info *vi = netdev_priv(dev);
1003 struct scatterlist sg;
1004
1005 sg_init_one(&sg, &vid, sizeof(vid));
1006
1007 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1008 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
1009 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1010 return 0;
1011 }
1012
1013 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
1014 {
1015 struct virtnet_info *vi = netdev_priv(dev);
1016 struct scatterlist sg;
1017
1018 sg_init_one(&sg, &vid, sizeof(vid));
1019
1020 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1021 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
1022 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1023 return 0;
1024 }
1025
1026 static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
1027 {
1028 int i;
1029
1030 /* In multiqueue mode, when the number of cpu is equal to the number of
1031 * queue pairs, we let the queue pairs to be private to one cpu by
1032 * setting the affinity hint to eliminate the contention.
1033 */
1034 if ((vi->curr_queue_pairs == 1 ||
1035 vi->max_queue_pairs != num_online_cpus()) && set) {
1036 if (vi->affinity_hint_set)
1037 set = false;
1038 else
1039 return;
1040 }
1041
1042 for (i = 0; i < vi->max_queue_pairs; i++) {
1043 int cpu = set ? i : -1;
1044 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1045 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1046 }
1047
1048 if (set)
1049 vi->affinity_hint_set = true;
1050 else
1051 vi->affinity_hint_set = false;
1052 }
1053
1054 static void virtnet_get_ringparam(struct net_device *dev,
1055 struct ethtool_ringparam *ring)
1056 {
1057 struct virtnet_info *vi = netdev_priv(dev);
1058
1059 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1060 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1061 ring->rx_pending = ring->rx_max_pending;
1062 ring->tx_pending = ring->tx_max_pending;
1063 }
1064
1065
1066 static void virtnet_get_drvinfo(struct net_device *dev,
1067 struct ethtool_drvinfo *info)
1068 {
1069 struct virtnet_info *vi = netdev_priv(dev);
1070 struct virtio_device *vdev = vi->vdev;
1071
1072 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1073 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1074 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1075
1076 }
1077
1078 static const struct ethtool_ops virtnet_ethtool_ops = {
1079 .get_drvinfo = virtnet_get_drvinfo,
1080 .get_link = ethtool_op_get_link,
1081 .get_ringparam = virtnet_get_ringparam,
1082 };
1083
1084 #define MIN_MTU 68
1085 #define MAX_MTU 65535
1086
1087 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1088 {
1089 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1090 return -EINVAL;
1091 dev->mtu = new_mtu;
1092 return 0;
1093 }
1094
1095 /* To avoid contending a lock hold by a vcpu who would exit to host, select the
1096 * txq based on the processor id.
1097 * TODO: handle cpu hotplug.
1098 */
1099 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
1100 {
1101 int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) :
1102 smp_processor_id();
1103
1104 while (unlikely(txq >= dev->real_num_tx_queues))
1105 txq -= dev->real_num_tx_queues;
1106
1107 return txq;
1108 }
1109
1110 static const struct net_device_ops virtnet_netdev = {
1111 .ndo_open = virtnet_open,
1112 .ndo_stop = virtnet_close,
1113 .ndo_start_xmit = start_xmit,
1114 .ndo_validate_addr = eth_validate_addr,
1115 .ndo_set_mac_address = virtnet_set_mac_address,
1116 .ndo_set_rx_mode = virtnet_set_rx_mode,
1117 .ndo_change_mtu = virtnet_change_mtu,
1118 .ndo_get_stats64 = virtnet_stats,
1119 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1120 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1121 .ndo_select_queue = virtnet_select_queue,
1122 #ifdef CONFIG_NET_POLL_CONTROLLER
1123 .ndo_poll_controller = virtnet_netpoll,
1124 #endif
1125 };
1126
1127 static void virtnet_config_changed_work(struct work_struct *work)
1128 {
1129 struct virtnet_info *vi =
1130 container_of(work, struct virtnet_info, config_work);
1131 u16 v;
1132
1133 mutex_lock(&vi->config_lock);
1134 if (!vi->config_enable)
1135 goto done;
1136
1137 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
1138 offsetof(struct virtio_net_config, status),
1139 &v) < 0)
1140 goto done;
1141
1142 if (v & VIRTIO_NET_S_ANNOUNCE) {
1143 netdev_notify_peers(vi->dev);
1144 virtnet_ack_link_announce(vi);
1145 }
1146
1147 /* Ignore unknown (future) status bits */
1148 v &= VIRTIO_NET_S_LINK_UP;
1149
1150 if (vi->status == v)
1151 goto done;
1152
1153 vi->status = v;
1154
1155 if (vi->status & VIRTIO_NET_S_LINK_UP) {
1156 netif_carrier_on(vi->dev);
1157 netif_tx_wake_all_queues(vi->dev);
1158 } else {
1159 netif_carrier_off(vi->dev);
1160 netif_tx_stop_all_queues(vi->dev);
1161 }
1162 done:
1163 mutex_unlock(&vi->config_lock);
1164 }
1165
1166 static void virtnet_config_changed(struct virtio_device *vdev)
1167 {
1168 struct virtnet_info *vi = vdev->priv;
1169
1170 schedule_work(&vi->config_work);
1171 }
1172
1173 static void virtnet_free_queues(struct virtnet_info *vi)
1174 {
1175 kfree(vi->rq);
1176 kfree(vi->sq);
1177 }
1178
1179 static void free_receive_bufs(struct virtnet_info *vi)
1180 {
1181 int i;
1182
1183 for (i = 0; i < vi->max_queue_pairs; i++) {
1184 while (vi->rq[i].pages)
1185 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1186 }
1187 }
1188
1189 static void free_unused_bufs(struct virtnet_info *vi)
1190 {
1191 void *buf;
1192 int i;
1193
1194 for (i = 0; i < vi->max_queue_pairs; i++) {
1195 struct virtqueue *vq = vi->sq[i].vq;
1196 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1197 dev_kfree_skb(buf);
1198 }
1199
1200 for (i = 0; i < vi->max_queue_pairs; i++) {
1201 struct virtqueue *vq = vi->rq[i].vq;
1202
1203 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1204 if (vi->mergeable_rx_bufs || vi->big_packets)
1205 give_pages(&vi->rq[i], buf);
1206 else
1207 dev_kfree_skb(buf);
1208 --vi->rq[i].num;
1209 }
1210 BUG_ON(vi->rq[i].num != 0);
1211 }
1212 }
1213
1214 static void virtnet_del_vqs(struct virtnet_info *vi)
1215 {
1216 struct virtio_device *vdev = vi->vdev;
1217
1218 virtnet_set_affinity(vi, false);
1219
1220 vdev->config->del_vqs(vdev);
1221
1222 virtnet_free_queues(vi);
1223 }
1224
1225 static int virtnet_find_vqs(struct virtnet_info *vi)
1226 {
1227 vq_callback_t **callbacks;
1228 struct virtqueue **vqs;
1229 int ret = -ENOMEM;
1230 int i, total_vqs;
1231 const char **names;
1232
1233 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1234 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1235 * possible control vq.
1236 */
1237 total_vqs = vi->max_queue_pairs * 2 +
1238 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1239
1240 /* Allocate space for find_vqs parameters */
1241 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1242 if (!vqs)
1243 goto err_vq;
1244 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1245 if (!callbacks)
1246 goto err_callback;
1247 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1248 if (!names)
1249 goto err_names;
1250
1251 /* Parameters for control virtqueue, if any */
1252 if (vi->has_cvq) {
1253 callbacks[total_vqs - 1] = NULL;
1254 names[total_vqs - 1] = "control";
1255 }
1256
1257 /* Allocate/initialize parameters for send/receive virtqueues */
1258 for (i = 0; i < vi->max_queue_pairs; i++) {
1259 callbacks[rxq2vq(i)] = skb_recv_done;
1260 callbacks[txq2vq(i)] = skb_xmit_done;
1261 sprintf(vi->rq[i].name, "input.%d", i);
1262 sprintf(vi->sq[i].name, "output.%d", i);
1263 names[rxq2vq(i)] = vi->rq[i].name;
1264 names[txq2vq(i)] = vi->sq[i].name;
1265 }
1266
1267 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1268 names);
1269 if (ret)
1270 goto err_find;
1271
1272 if (vi->has_cvq) {
1273 vi->cvq = vqs[total_vqs - 1];
1274 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1275 vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1276 }
1277
1278 for (i = 0; i < vi->max_queue_pairs; i++) {
1279 vi->rq[i].vq = vqs[rxq2vq(i)];
1280 vi->sq[i].vq = vqs[txq2vq(i)];
1281 }
1282
1283 kfree(names);
1284 kfree(callbacks);
1285 kfree(vqs);
1286
1287 return 0;
1288
1289 err_find:
1290 kfree(names);
1291 err_names:
1292 kfree(callbacks);
1293 err_callback:
1294 kfree(vqs);
1295 err_vq:
1296 return ret;
1297 }
1298
1299 static int virtnet_alloc_queues(struct virtnet_info *vi)
1300 {
1301 int i;
1302
1303 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1304 if (!vi->sq)
1305 goto err_sq;
1306 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1307 if (!vi->sq)
1308 goto err_rq;
1309
1310 INIT_DELAYED_WORK(&vi->refill, refill_work);
1311 for (i = 0; i < vi->max_queue_pairs; i++) {
1312 vi->rq[i].pages = NULL;
1313 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1314 napi_weight);
1315
1316 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1317 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1318 }
1319
1320 return 0;
1321
1322 err_rq:
1323 kfree(vi->sq);
1324 err_sq:
1325 return -ENOMEM;
1326 }
1327
1328 static int init_vqs(struct virtnet_info *vi)
1329 {
1330 int ret;
1331
1332 /* Allocate send & receive queues */
1333 ret = virtnet_alloc_queues(vi);
1334 if (ret)
1335 goto err;
1336
1337 ret = virtnet_find_vqs(vi);
1338 if (ret)
1339 goto err_free;
1340
1341 virtnet_set_affinity(vi, true);
1342 return 0;
1343
1344 err_free:
1345 virtnet_free_queues(vi);
1346 err:
1347 return ret;
1348 }
1349
1350 static int virtnet_probe(struct virtio_device *vdev)
1351 {
1352 int i, err;
1353 struct net_device *dev;
1354 struct virtnet_info *vi;
1355 u16 max_queue_pairs;
1356
1357 /* Find if host supports multiqueue virtio_net device */
1358 err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
1359 offsetof(struct virtio_net_config,
1360 max_virtqueue_pairs), &max_queue_pairs);
1361
1362 /* We need at least 2 queue's */
1363 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1364 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1365 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1366 max_queue_pairs = 1;
1367
1368 /* Allocate ourselves a network device with room for our info */
1369 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1370 if (!dev)
1371 return -ENOMEM;
1372
1373 /* Set up network device as normal. */
1374 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1375 dev->netdev_ops = &virtnet_netdev;
1376 dev->features = NETIF_F_HIGHDMA;
1377
1378 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1379 SET_NETDEV_DEV(dev, &vdev->dev);
1380
1381 /* Do we support "hardware" checksums? */
1382 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1383 /* This opens up the world of extra features. */
1384 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1385 if (csum)
1386 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1387
1388 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1389 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1390 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1391 }
1392 /* Individual feature bits: what can host handle? */
1393 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1394 dev->hw_features |= NETIF_F_TSO;
1395 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1396 dev->hw_features |= NETIF_F_TSO6;
1397 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1398 dev->hw_features |= NETIF_F_TSO_ECN;
1399 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1400 dev->hw_features |= NETIF_F_UFO;
1401
1402 if (gso)
1403 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1404 /* (!csum && gso) case will be fixed by register_netdev() */
1405 }
1406
1407 /* Configuration may specify what MAC to use. Otherwise random. */
1408 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1409 offsetof(struct virtio_net_config, mac),
1410 dev->dev_addr, dev->addr_len) < 0)
1411 eth_hw_addr_random(dev);
1412
1413 /* Set up our device-specific information */
1414 vi = netdev_priv(dev);
1415 vi->dev = dev;
1416 vi->vdev = vdev;
1417 vdev->priv = vi;
1418 vi->stats = alloc_percpu(struct virtnet_stats);
1419 err = -ENOMEM;
1420 if (vi->stats == NULL)
1421 goto free;
1422
1423 mutex_init(&vi->config_lock);
1424 vi->config_enable = true;
1425 INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1426
1427 /* If we can receive ANY GSO packets, we must allocate large ones. */
1428 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1429 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1430 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1431 vi->big_packets = true;
1432
1433 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1434 vi->mergeable_rx_bufs = true;
1435
1436 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1437 vi->has_cvq = true;
1438
1439 /* Use single tx/rx queue pair as default */
1440 vi->curr_queue_pairs = 1;
1441 vi->max_queue_pairs = max_queue_pairs;
1442
1443 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1444 err = init_vqs(vi);
1445 if (err)
1446 goto free_stats;
1447
1448 netif_set_real_num_tx_queues(dev, 1);
1449 netif_set_real_num_rx_queues(dev, 1);
1450
1451 err = register_netdev(dev);
1452 if (err) {
1453 pr_debug("virtio_net: registering device failed\n");
1454 goto free_vqs;
1455 }
1456
1457 /* Last of all, set up some receive buffers. */
1458 for (i = 0; i < vi->max_queue_pairs; i++) {
1459 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1460
1461 /* If we didn't even get one input buffer, we're useless. */
1462 if (vi->rq[i].num == 0) {
1463 free_unused_bufs(vi);
1464 err = -ENOMEM;
1465 goto free_recv_bufs;
1466 }
1467 }
1468
1469 /* Assume link up if device can't report link status,
1470 otherwise get link status from config. */
1471 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1472 netif_carrier_off(dev);
1473 schedule_work(&vi->config_work);
1474 } else {
1475 vi->status = VIRTIO_NET_S_LINK_UP;
1476 netif_carrier_on(dev);
1477 }
1478
1479 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1480 dev->name, max_queue_pairs);
1481
1482 return 0;
1483
1484 free_recv_bufs:
1485 free_receive_bufs(vi);
1486 unregister_netdev(dev);
1487 free_vqs:
1488 cancel_delayed_work_sync(&vi->refill);
1489 virtnet_del_vqs(vi);
1490 free_stats:
1491 free_percpu(vi->stats);
1492 free:
1493 free_netdev(dev);
1494 return err;
1495 }
1496
1497 static void remove_vq_common(struct virtnet_info *vi)
1498 {
1499 vi->vdev->config->reset(vi->vdev);
1500
1501 /* Free unused buffers in both send and recv, if any. */
1502 free_unused_bufs(vi);
1503
1504 free_receive_bufs(vi);
1505
1506 virtnet_del_vqs(vi);
1507 }
1508
1509 static void virtnet_remove(struct virtio_device *vdev)
1510 {
1511 struct virtnet_info *vi = vdev->priv;
1512
1513 /* Prevent config work handler from accessing the device. */
1514 mutex_lock(&vi->config_lock);
1515 vi->config_enable = false;
1516 mutex_unlock(&vi->config_lock);
1517
1518 unregister_netdev(vi->dev);
1519
1520 remove_vq_common(vi);
1521
1522 flush_work(&vi->config_work);
1523
1524 free_percpu(vi->stats);
1525 free_netdev(vi->dev);
1526 }
1527
1528 #ifdef CONFIG_PM
1529 static int virtnet_freeze(struct virtio_device *vdev)
1530 {
1531 struct virtnet_info *vi = vdev->priv;
1532 int i;
1533
1534 /* Prevent config work handler from accessing the device */
1535 mutex_lock(&vi->config_lock);
1536 vi->config_enable = false;
1537 mutex_unlock(&vi->config_lock);
1538
1539 netif_device_detach(vi->dev);
1540 cancel_delayed_work_sync(&vi->refill);
1541
1542 if (netif_running(vi->dev))
1543 for (i = 0; i < vi->max_queue_pairs; i++) {
1544 napi_disable(&vi->rq[i].napi);
1545 netif_napi_del(&vi->rq[i].napi);
1546 }
1547
1548 remove_vq_common(vi);
1549
1550 flush_work(&vi->config_work);
1551
1552 return 0;
1553 }
1554
1555 static int virtnet_restore(struct virtio_device *vdev)
1556 {
1557 struct virtnet_info *vi = vdev->priv;
1558 int err, i;
1559
1560 err = init_vqs(vi);
1561 if (err)
1562 return err;
1563
1564 if (netif_running(vi->dev))
1565 for (i = 0; i < vi->max_queue_pairs; i++)
1566 virtnet_napi_enable(&vi->rq[i]);
1567
1568 netif_device_attach(vi->dev);
1569
1570 for (i = 0; i < vi->max_queue_pairs; i++)
1571 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1572 schedule_delayed_work(&vi->refill, 0);
1573
1574 mutex_lock(&vi->config_lock);
1575 vi->config_enable = true;
1576 mutex_unlock(&vi->config_lock);
1577
1578 virtnet_set_queues(vi, vi->curr_queue_pairs);
1579
1580 return 0;
1581 }
1582 #endif
1583
1584 static struct virtio_device_id id_table[] = {
1585 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1586 { 0 },
1587 };
1588
1589 static unsigned int features[] = {
1590 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1591 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1592 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1593 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1594 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1595 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1596 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1597 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1598 };
1599
1600 static struct virtio_driver virtio_net_driver = {
1601 .feature_table = features,
1602 .feature_table_size = ARRAY_SIZE(features),
1603 .driver.name = KBUILD_MODNAME,
1604 .driver.owner = THIS_MODULE,
1605 .id_table = id_table,
1606 .probe = virtnet_probe,
1607 .remove = virtnet_remove,
1608 .config_changed = virtnet_config_changed,
1609 #ifdef CONFIG_PM
1610 .freeze = virtnet_freeze,
1611 .restore = virtnet_restore,
1612 #endif
1613 };
1614
1615 static int __init init(void)
1616 {
1617 return register_virtio_driver(&virtio_net_driver);
1618 }
1619
1620 static void __exit fini(void)
1621 {
1622 unregister_virtio_driver(&virtio_net_driver);
1623 }
1624 module_init(init);
1625 module_exit(fini);
1626
1627 MODULE_DEVICE_TABLE(virtio, id_table);
1628 MODULE_DESCRIPTION("Virtio network driver");
1629 MODULE_LICENSE("GPL");
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