Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / drivers / net / virtio_net.c
blob3d2a90a626498d20c96ba7729beacec16b9b5040
1 /* A network driver using virtio.
3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
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.
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.
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
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 #include <linux/cpu.h>
31 static int napi_weight = NAPI_POLL_WEIGHT;
32 module_param(napi_weight, int, 0444);
34 static bool csum = true, gso = true;
35 module_param(csum, bool, 0444);
36 module_param(gso, bool, 0444);
38 /* FIXME: MTU in config. */
39 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
40 #define GOOD_COPY_LEN 128
42 #define VIRTNET_DRIVER_VERSION "1.0.0"
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;
50 u64 rx_bytes;
51 u64 rx_packets;
54 /* Internal representation of a send virtqueue */
55 struct send_queue {
56 /* Virtqueue associated with this send _queue */
57 struct virtqueue *vq;
59 /* TX: fragments + linear part + virtio header */
60 struct scatterlist sg[MAX_SKB_FRAGS + 2];
62 /* Name of the send queue: output.$index */
63 char name[40];
66 /* Internal representation of a receive virtqueue */
67 struct receive_queue {
68 /* Virtqueue associated with this receive_queue */
69 struct virtqueue *vq;
71 struct napi_struct napi;
73 /* Number of input buffers, and max we've ever had. */
74 unsigned int num, max;
76 /* Chain pages by the private ptr. */
77 struct page *pages;
79 /* RX: fragments + linear part + virtio header */
80 struct scatterlist sg[MAX_SKB_FRAGS + 2];
82 /* Name of this receive queue: input.$index */
83 char name[40];
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;
94 /* Max # of queue pairs supported by the device */
95 u16 max_queue_pairs;
97 /* # of queue pairs currently used by the driver */
98 u16 curr_queue_pairs;
100 /* I like... big packets and I cannot lie! */
101 bool big_packets;
103 /* Host will merge rx buffers for big packets (shake it! shake it!) */
104 bool mergeable_rx_bufs;
106 /* Has control virtqueue */
107 bool has_cvq;
109 /* enable config space updates */
110 bool config_enable;
112 /* Active statistics */
113 struct virtnet_stats __percpu *stats;
115 /* Work struct for refilling if we run low on memory. */
116 struct delayed_work refill;
118 /* Work struct for config space updates */
119 struct work_struct config_work;
121 /* Lock for config space updates */
122 struct mutex config_lock;
124 /* Does the affinity hint is set for virtqueues? */
125 bool affinity_hint_set;
127 /* Per-cpu variable to show the mapping from CPU to virtqueue */
128 int __percpu *vq_index;
130 /* CPU hot plug notifier */
131 struct notifier_block nb;
134 struct skb_vnet_hdr {
135 union {
136 struct virtio_net_hdr hdr;
137 struct virtio_net_hdr_mrg_rxbuf mhdr;
141 struct padded_vnet_hdr {
142 struct virtio_net_hdr hdr;
144 * virtio_net_hdr should be in a separated sg buffer because of a
145 * QEMU bug, and data sg buffer shares same page with this header sg.
146 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
148 char padding[6];
151 /* Converting between virtqueue no. and kernel tx/rx queue no.
152 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
154 static int vq2txq(struct virtqueue *vq)
156 return (vq->index - 1) / 2;
159 static int txq2vq(int txq)
161 return txq * 2 + 1;
164 static int vq2rxq(struct virtqueue *vq)
166 return vq->index / 2;
169 static int rxq2vq(int rxq)
171 return rxq * 2;
174 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
176 return (struct skb_vnet_hdr *)skb->cb;
180 * private is used to chain pages for big packets, put the whole
181 * most recent used list in the beginning for reuse
183 static void give_pages(struct receive_queue *rq, struct page *page)
185 struct page *end;
187 /* Find end of list, sew whole thing into vi->rq.pages. */
188 for (end = page; end->private; end = (struct page *)end->private);
189 end->private = (unsigned long)rq->pages;
190 rq->pages = page;
193 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
195 struct page *p = rq->pages;
197 if (p) {
198 rq->pages = (struct page *)p->private;
199 /* clear private here, it is used to chain pages */
200 p->private = 0;
201 } else
202 p = alloc_page(gfp_mask);
203 return p;
206 static void skb_xmit_done(struct virtqueue *vq)
208 struct virtnet_info *vi = vq->vdev->priv;
210 /* Suppress further interrupts. */
211 virtqueue_disable_cb(vq);
213 /* We were probably waiting for more output buffers. */
214 netif_wake_subqueue(vi->dev, vq2txq(vq));
217 static void set_skb_frag(struct sk_buff *skb, struct page *page,
218 unsigned int offset, unsigned int *len)
220 int size = min((unsigned)PAGE_SIZE - offset, *len);
221 int i = skb_shinfo(skb)->nr_frags;
223 __skb_fill_page_desc(skb, i, page, offset, size);
225 skb->data_len += size;
226 skb->len += size;
227 skb->truesize += PAGE_SIZE;
228 skb_shinfo(skb)->nr_frags++;
229 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
230 *len -= size;
233 /* Called from bottom half context */
234 static struct sk_buff *page_to_skb(struct receive_queue *rq,
235 struct page *page, unsigned int len)
237 struct virtnet_info *vi = rq->vq->vdev->priv;
238 struct sk_buff *skb;
239 struct skb_vnet_hdr *hdr;
240 unsigned int copy, hdr_len, offset;
241 char *p;
243 p = page_address(page);
245 /* copy small packet so we can reuse these pages for small data */
246 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
247 if (unlikely(!skb))
248 return NULL;
250 hdr = skb_vnet_hdr(skb);
252 if (vi->mergeable_rx_bufs) {
253 hdr_len = sizeof hdr->mhdr;
254 offset = hdr_len;
255 } else {
256 hdr_len = sizeof hdr->hdr;
257 offset = sizeof(struct padded_vnet_hdr);
260 memcpy(hdr, p, hdr_len);
262 len -= hdr_len;
263 p += offset;
265 copy = len;
266 if (copy > skb_tailroom(skb))
267 copy = skb_tailroom(skb);
268 memcpy(skb_put(skb, copy), p, copy);
270 len -= copy;
271 offset += copy;
274 * Verify that we can indeed put this data into a skb.
275 * This is here to handle cases when the device erroneously
276 * tries to receive more than is possible. This is usually
277 * the case of a broken device.
279 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
280 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
281 dev_kfree_skb(skb);
282 return NULL;
285 while (len) {
286 set_skb_frag(skb, page, offset, &len);
287 page = (struct page *)page->private;
288 offset = 0;
291 if (page)
292 give_pages(rq, page);
294 return skb;
297 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
299 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
300 struct page *page;
301 int num_buf, i, len;
303 num_buf = hdr->mhdr.num_buffers;
304 while (--num_buf) {
305 i = skb_shinfo(skb)->nr_frags;
306 if (i >= MAX_SKB_FRAGS) {
307 pr_debug("%s: packet too long\n", skb->dev->name);
308 skb->dev->stats.rx_length_errors++;
309 return -EINVAL;
311 page = virtqueue_get_buf(rq->vq, &len);
312 if (!page) {
313 pr_debug("%s: rx error: %d buffers missing\n",
314 skb->dev->name, hdr->mhdr.num_buffers);
315 skb->dev->stats.rx_length_errors++;
316 return -EINVAL;
319 if (len > PAGE_SIZE)
320 len = PAGE_SIZE;
322 set_skb_frag(skb, page, 0, &len);
324 --rq->num;
326 return 0;
329 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
331 struct virtnet_info *vi = rq->vq->vdev->priv;
332 struct net_device *dev = vi->dev;
333 struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
334 struct sk_buff *skb;
335 struct page *page;
336 struct skb_vnet_hdr *hdr;
338 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
339 pr_debug("%s: short packet %i\n", dev->name, len);
340 dev->stats.rx_length_errors++;
341 if (vi->mergeable_rx_bufs || vi->big_packets)
342 give_pages(rq, buf);
343 else
344 dev_kfree_skb(buf);
345 return;
348 if (!vi->mergeable_rx_bufs && !vi->big_packets) {
349 skb = buf;
350 len -= sizeof(struct virtio_net_hdr);
351 skb_trim(skb, len);
352 } else {
353 page = buf;
354 skb = page_to_skb(rq, page, len);
355 if (unlikely(!skb)) {
356 dev->stats.rx_dropped++;
357 give_pages(rq, page);
358 return;
360 if (vi->mergeable_rx_bufs)
361 if (receive_mergeable(rq, skb)) {
362 dev_kfree_skb(skb);
363 return;
367 hdr = skb_vnet_hdr(skb);
369 u64_stats_update_begin(&stats->rx_syncp);
370 stats->rx_bytes += skb->len;
371 stats->rx_packets++;
372 u64_stats_update_end(&stats->rx_syncp);
374 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
375 pr_debug("Needs csum!\n");
376 if (!skb_partial_csum_set(skb,
377 hdr->hdr.csum_start,
378 hdr->hdr.csum_offset))
379 goto frame_err;
380 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
381 skb->ip_summed = CHECKSUM_UNNECESSARY;
384 skb->protocol = eth_type_trans(skb, dev);
385 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
386 ntohs(skb->protocol), skb->len, skb->pkt_type);
388 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
389 pr_debug("GSO!\n");
390 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
391 case VIRTIO_NET_HDR_GSO_TCPV4:
392 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
393 break;
394 case VIRTIO_NET_HDR_GSO_UDP:
395 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
396 break;
397 case VIRTIO_NET_HDR_GSO_TCPV6:
398 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
399 break;
400 default:
401 net_warn_ratelimited("%s: bad gso type %u.\n",
402 dev->name, hdr->hdr.gso_type);
403 goto frame_err;
406 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
407 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
409 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
410 if (skb_shinfo(skb)->gso_size == 0) {
411 net_warn_ratelimited("%s: zero gso size.\n", dev->name);
412 goto frame_err;
415 /* Header must be checked, and gso_segs computed. */
416 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
417 skb_shinfo(skb)->gso_segs = 0;
420 netif_receive_skb(skb);
421 return;
423 frame_err:
424 dev->stats.rx_frame_errors++;
425 dev_kfree_skb(skb);
428 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
430 struct virtnet_info *vi = rq->vq->vdev->priv;
431 struct sk_buff *skb;
432 struct skb_vnet_hdr *hdr;
433 int err;
435 skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
436 if (unlikely(!skb))
437 return -ENOMEM;
439 skb_put(skb, MAX_PACKET_LEN);
441 hdr = skb_vnet_hdr(skb);
442 sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
444 skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
446 err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
447 if (err < 0)
448 dev_kfree_skb(skb);
450 return err;
453 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
455 struct page *first, *list = NULL;
456 char *p;
457 int i, err, offset;
459 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
460 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
461 first = get_a_page(rq, gfp);
462 if (!first) {
463 if (list)
464 give_pages(rq, list);
465 return -ENOMEM;
467 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
469 /* chain new page in list head to match sg */
470 first->private = (unsigned long)list;
471 list = first;
474 first = get_a_page(rq, gfp);
475 if (!first) {
476 give_pages(rq, list);
477 return -ENOMEM;
479 p = page_address(first);
481 /* rq->sg[0], rq->sg[1] share the same page */
482 /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
483 sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
485 /* rq->sg[1] for data packet, from offset */
486 offset = sizeof(struct padded_vnet_hdr);
487 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
489 /* chain first in list head */
490 first->private = (unsigned long)list;
491 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
492 first, gfp);
493 if (err < 0)
494 give_pages(rq, first);
496 return err;
499 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
501 struct page *page;
502 int err;
504 page = get_a_page(rq, gfp);
505 if (!page)
506 return -ENOMEM;
508 sg_init_one(rq->sg, page_address(page), PAGE_SIZE);
510 err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, page, gfp);
511 if (err < 0)
512 give_pages(rq, page);
514 return err;
518 * Returns false if we couldn't fill entirely (OOM).
520 * Normally run in the receive path, but can also be run from ndo_open
521 * before we're receiving packets, or from refill_work which is
522 * careful to disable receiving (using napi_disable).
524 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
526 struct virtnet_info *vi = rq->vq->vdev->priv;
527 int err;
528 bool oom;
530 do {
531 if (vi->mergeable_rx_bufs)
532 err = add_recvbuf_mergeable(rq, gfp);
533 else if (vi->big_packets)
534 err = add_recvbuf_big(rq, gfp);
535 else
536 err = add_recvbuf_small(rq, gfp);
538 oom = err == -ENOMEM;
539 if (err)
540 break;
541 ++rq->num;
542 } while (rq->vq->num_free);
543 if (unlikely(rq->num > rq->max))
544 rq->max = rq->num;
545 virtqueue_kick(rq->vq);
546 return !oom;
549 static void skb_recv_done(struct virtqueue *rvq)
551 struct virtnet_info *vi = rvq->vdev->priv;
552 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
554 /* Schedule NAPI, Suppress further interrupts if successful. */
555 if (napi_schedule_prep(&rq->napi)) {
556 virtqueue_disable_cb(rvq);
557 __napi_schedule(&rq->napi);
561 static void virtnet_napi_enable(struct receive_queue *rq)
563 napi_enable(&rq->napi);
565 /* If all buffers were filled by other side before we napi_enabled, we
566 * won't get another interrupt, so process any outstanding packets
567 * now. virtnet_poll wants re-enable the queue, so we disable here.
568 * We synchronize against interrupts via NAPI_STATE_SCHED */
569 if (napi_schedule_prep(&rq->napi)) {
570 virtqueue_disable_cb(rq->vq);
571 local_bh_disable();
572 __napi_schedule(&rq->napi);
573 local_bh_enable();
577 static void refill_work(struct work_struct *work)
579 struct virtnet_info *vi =
580 container_of(work, struct virtnet_info, refill.work);
581 bool still_empty;
582 int i;
584 for (i = 0; i < vi->curr_queue_pairs; i++) {
585 struct receive_queue *rq = &vi->rq[i];
587 napi_disable(&rq->napi);
588 still_empty = !try_fill_recv(rq, GFP_KERNEL);
589 virtnet_napi_enable(rq);
591 /* In theory, this can happen: if we don't get any buffers in
592 * we will *never* try to fill again.
594 if (still_empty)
595 schedule_delayed_work(&vi->refill, HZ/2);
599 static int virtnet_poll(struct napi_struct *napi, int budget)
601 struct receive_queue *rq =
602 container_of(napi, struct receive_queue, napi);
603 struct virtnet_info *vi = rq->vq->vdev->priv;
604 void *buf;
605 unsigned int r, len, received = 0;
607 again:
608 while (received < budget &&
609 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
610 receive_buf(rq, buf, len);
611 --rq->num;
612 received++;
615 if (rq->num < rq->max / 2) {
616 if (!try_fill_recv(rq, GFP_ATOMIC))
617 schedule_delayed_work(&vi->refill, 0);
620 /* Out of packets? */
621 if (received < budget) {
622 r = virtqueue_enable_cb_prepare(rq->vq);
623 napi_complete(napi);
624 if (unlikely(virtqueue_poll(rq->vq, r)) &&
625 napi_schedule_prep(napi)) {
626 virtqueue_disable_cb(rq->vq);
627 __napi_schedule(napi);
628 goto again;
632 return received;
635 static int virtnet_open(struct net_device *dev)
637 struct virtnet_info *vi = netdev_priv(dev);
638 int i;
640 for (i = 0; i < vi->max_queue_pairs; i++) {
641 if (i < vi->curr_queue_pairs)
642 /* Make sure we have some buffers: if oom use wq. */
643 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
644 schedule_delayed_work(&vi->refill, 0);
645 virtnet_napi_enable(&vi->rq[i]);
648 return 0;
651 static void free_old_xmit_skbs(struct send_queue *sq)
653 struct sk_buff *skb;
654 unsigned int len;
655 struct virtnet_info *vi = sq->vq->vdev->priv;
656 struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
658 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
659 pr_debug("Sent skb %p\n", skb);
661 u64_stats_update_begin(&stats->tx_syncp);
662 stats->tx_bytes += skb->len;
663 stats->tx_packets++;
664 u64_stats_update_end(&stats->tx_syncp);
666 dev_kfree_skb_any(skb);
670 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
672 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
673 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
674 struct virtnet_info *vi = sq->vq->vdev->priv;
675 unsigned num_sg;
677 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
679 if (skb->ip_summed == CHECKSUM_PARTIAL) {
680 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
681 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
682 hdr->hdr.csum_offset = skb->csum_offset;
683 } else {
684 hdr->hdr.flags = 0;
685 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
688 if (skb_is_gso(skb)) {
689 hdr->hdr.hdr_len = skb_headlen(skb);
690 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
691 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
692 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
693 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
694 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
695 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
696 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
697 else
698 BUG();
699 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
700 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
701 } else {
702 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
703 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
706 hdr->mhdr.num_buffers = 0;
708 /* Encode metadata header at front. */
709 if (vi->mergeable_rx_bufs)
710 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
711 else
712 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
714 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
715 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
718 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
720 struct virtnet_info *vi = netdev_priv(dev);
721 int qnum = skb_get_queue_mapping(skb);
722 struct send_queue *sq = &vi->sq[qnum];
723 int err;
725 /* Free up any pending old buffers before queueing new ones. */
726 free_old_xmit_skbs(sq);
728 /* Try to transmit */
729 err = xmit_skb(sq, skb);
731 /* This should not happen! */
732 if (unlikely(err)) {
733 dev->stats.tx_fifo_errors++;
734 if (net_ratelimit())
735 dev_warn(&dev->dev,
736 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
737 dev->stats.tx_dropped++;
738 kfree_skb(skb);
739 return NETDEV_TX_OK;
741 virtqueue_kick(sq->vq);
743 /* Don't wait up for transmitted skbs to be freed. */
744 skb_orphan(skb);
745 nf_reset(skb);
747 /* Apparently nice girls don't return TX_BUSY; stop the queue
748 * before it gets out of hand. Naturally, this wastes entries. */
749 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
750 netif_stop_subqueue(dev, qnum);
751 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
752 /* More just got used, free them then recheck. */
753 free_old_xmit_skbs(sq);
754 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
755 netif_start_subqueue(dev, qnum);
756 virtqueue_disable_cb(sq->vq);
761 return NETDEV_TX_OK;
765 * Send command via the control virtqueue and check status. Commands
766 * supported by the hypervisor, as indicated by feature bits, should
767 * never fail unless improperly formated.
769 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
770 struct scatterlist *out,
771 struct scatterlist *in)
773 struct scatterlist *sgs[4], hdr, stat;
774 struct virtio_net_ctrl_hdr ctrl;
775 virtio_net_ctrl_ack status = ~0;
776 unsigned out_num = 0, in_num = 0, tmp;
778 /* Caller should know better */
779 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
781 ctrl.class = class;
782 ctrl.cmd = cmd;
783 /* Add header */
784 sg_init_one(&hdr, &ctrl, sizeof(ctrl));
785 sgs[out_num++] = &hdr;
787 if (out)
788 sgs[out_num++] = out;
789 if (in)
790 sgs[out_num + in_num++] = in;
792 /* Add return status. */
793 sg_init_one(&stat, &status, sizeof(status));
794 sgs[out_num + in_num++] = &stat;
796 BUG_ON(out_num + in_num > ARRAY_SIZE(sgs));
797 BUG_ON(virtqueue_add_sgs(vi->cvq, sgs, out_num, in_num, vi, GFP_ATOMIC)
798 < 0);
800 virtqueue_kick(vi->cvq);
802 /* Spin for a response, the kick causes an ioport write, trapping
803 * into the hypervisor, so the request should be handled immediately.
805 while (!virtqueue_get_buf(vi->cvq, &tmp))
806 cpu_relax();
808 return status == VIRTIO_NET_OK;
811 static int virtnet_set_mac_address(struct net_device *dev, void *p)
813 struct virtnet_info *vi = netdev_priv(dev);
814 struct virtio_device *vdev = vi->vdev;
815 int ret;
816 struct sockaddr *addr = p;
817 struct scatterlist sg;
819 ret = eth_prepare_mac_addr_change(dev, p);
820 if (ret)
821 return ret;
823 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
824 sg_init_one(&sg, addr->sa_data, dev->addr_len);
825 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
826 VIRTIO_NET_CTRL_MAC_ADDR_SET,
827 &sg, NULL)) {
828 dev_warn(&vdev->dev,
829 "Failed to set mac address by vq command.\n");
830 return -EINVAL;
832 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
833 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
834 addr->sa_data, dev->addr_len);
837 eth_commit_mac_addr_change(dev, p);
839 return 0;
842 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
843 struct rtnl_link_stats64 *tot)
845 struct virtnet_info *vi = netdev_priv(dev);
846 int cpu;
847 unsigned int start;
849 for_each_possible_cpu(cpu) {
850 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
851 u64 tpackets, tbytes, rpackets, rbytes;
853 do {
854 start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
855 tpackets = stats->tx_packets;
856 tbytes = stats->tx_bytes;
857 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
859 do {
860 start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
861 rpackets = stats->rx_packets;
862 rbytes = stats->rx_bytes;
863 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
865 tot->rx_packets += rpackets;
866 tot->tx_packets += tpackets;
867 tot->rx_bytes += rbytes;
868 tot->tx_bytes += tbytes;
871 tot->tx_dropped = dev->stats.tx_dropped;
872 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
873 tot->rx_dropped = dev->stats.rx_dropped;
874 tot->rx_length_errors = dev->stats.rx_length_errors;
875 tot->rx_frame_errors = dev->stats.rx_frame_errors;
877 return tot;
880 #ifdef CONFIG_NET_POLL_CONTROLLER
881 static void virtnet_netpoll(struct net_device *dev)
883 struct virtnet_info *vi = netdev_priv(dev);
884 int i;
886 for (i = 0; i < vi->curr_queue_pairs; i++)
887 napi_schedule(&vi->rq[i].napi);
889 #endif
891 static void virtnet_ack_link_announce(struct virtnet_info *vi)
893 rtnl_lock();
894 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
895 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, NULL))
896 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
897 rtnl_unlock();
900 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
902 struct scatterlist sg;
903 struct virtio_net_ctrl_mq s;
904 struct net_device *dev = vi->dev;
906 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
907 return 0;
909 s.virtqueue_pairs = queue_pairs;
910 sg_init_one(&sg, &s, sizeof(s));
912 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
913 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, NULL)) {
914 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
915 queue_pairs);
916 return -EINVAL;
917 } else {
918 vi->curr_queue_pairs = queue_pairs;
919 schedule_delayed_work(&vi->refill, 0);
922 return 0;
925 static int virtnet_close(struct net_device *dev)
927 struct virtnet_info *vi = netdev_priv(dev);
928 int i;
930 /* Make sure refill_work doesn't re-enable napi! */
931 cancel_delayed_work_sync(&vi->refill);
933 for (i = 0; i < vi->max_queue_pairs; i++)
934 napi_disable(&vi->rq[i].napi);
936 return 0;
939 static void virtnet_set_rx_mode(struct net_device *dev)
941 struct virtnet_info *vi = netdev_priv(dev);
942 struct scatterlist sg[2];
943 u8 promisc, allmulti;
944 struct virtio_net_ctrl_mac *mac_data;
945 struct netdev_hw_addr *ha;
946 int uc_count;
947 int mc_count;
948 void *buf;
949 int i;
951 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
952 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
953 return;
955 promisc = ((dev->flags & IFF_PROMISC) != 0);
956 allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
958 sg_init_one(sg, &promisc, sizeof(promisc));
960 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
961 VIRTIO_NET_CTRL_RX_PROMISC,
962 sg, NULL))
963 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
964 promisc ? "en" : "dis");
966 sg_init_one(sg, &allmulti, sizeof(allmulti));
968 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
969 VIRTIO_NET_CTRL_RX_ALLMULTI,
970 sg, NULL))
971 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
972 allmulti ? "en" : "dis");
974 uc_count = netdev_uc_count(dev);
975 mc_count = netdev_mc_count(dev);
976 /* MAC filter - use one buffer for both lists */
977 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
978 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
979 mac_data = buf;
980 if (!buf)
981 return;
983 sg_init_table(sg, 2);
985 /* Store the unicast list and count in the front of the buffer */
986 mac_data->entries = uc_count;
987 i = 0;
988 netdev_for_each_uc_addr(ha, dev)
989 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
991 sg_set_buf(&sg[0], mac_data,
992 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
994 /* multicast list and count fill the end */
995 mac_data = (void *)&mac_data->macs[uc_count][0];
997 mac_data->entries = mc_count;
998 i = 0;
999 netdev_for_each_mc_addr(ha, dev)
1000 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1002 sg_set_buf(&sg[1], mac_data,
1003 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1005 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1006 VIRTIO_NET_CTRL_MAC_TABLE_SET,
1007 sg, NULL))
1008 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
1010 kfree(buf);
1013 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1014 __be16 proto, u16 vid)
1016 struct virtnet_info *vi = netdev_priv(dev);
1017 struct scatterlist sg;
1019 sg_init_one(&sg, &vid, sizeof(vid));
1021 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1022 VIRTIO_NET_CTRL_VLAN_ADD, &sg, NULL))
1023 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1024 return 0;
1027 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1028 __be16 proto, u16 vid)
1030 struct virtnet_info *vi = netdev_priv(dev);
1031 struct scatterlist sg;
1033 sg_init_one(&sg, &vid, sizeof(vid));
1035 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1036 VIRTIO_NET_CTRL_VLAN_DEL, &sg, NULL))
1037 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1038 return 0;
1041 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1043 int i;
1044 int cpu;
1046 if (vi->affinity_hint_set) {
1047 for (i = 0; i < vi->max_queue_pairs; i++) {
1048 virtqueue_set_affinity(vi->rq[i].vq, -1);
1049 virtqueue_set_affinity(vi->sq[i].vq, -1);
1052 vi->affinity_hint_set = false;
1055 i = 0;
1056 for_each_online_cpu(cpu) {
1057 if (cpu == hcpu) {
1058 *per_cpu_ptr(vi->vq_index, cpu) = -1;
1059 } else {
1060 *per_cpu_ptr(vi->vq_index, cpu) =
1061 ++i % vi->curr_queue_pairs;
1066 static void virtnet_set_affinity(struct virtnet_info *vi)
1068 int i;
1069 int cpu;
1071 /* In multiqueue mode, when the number of cpu is equal to the number of
1072 * queue pairs, we let the queue pairs to be private to one cpu by
1073 * setting the affinity hint to eliminate the contention.
1075 if (vi->curr_queue_pairs == 1 ||
1076 vi->max_queue_pairs != num_online_cpus()) {
1077 virtnet_clean_affinity(vi, -1);
1078 return;
1081 i = 0;
1082 for_each_online_cpu(cpu) {
1083 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1084 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1085 *per_cpu_ptr(vi->vq_index, cpu) = i;
1086 i++;
1089 vi->affinity_hint_set = true;
1092 static int virtnet_cpu_callback(struct notifier_block *nfb,
1093 unsigned long action, void *hcpu)
1095 struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1097 switch(action & ~CPU_TASKS_FROZEN) {
1098 case CPU_ONLINE:
1099 case CPU_DOWN_FAILED:
1100 case CPU_DEAD:
1101 virtnet_set_affinity(vi);
1102 break;
1103 case CPU_DOWN_PREPARE:
1104 virtnet_clean_affinity(vi, (long)hcpu);
1105 break;
1106 default:
1107 break;
1109 return NOTIFY_OK;
1112 static void virtnet_get_ringparam(struct net_device *dev,
1113 struct ethtool_ringparam *ring)
1115 struct virtnet_info *vi = netdev_priv(dev);
1117 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1118 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1119 ring->rx_pending = ring->rx_max_pending;
1120 ring->tx_pending = ring->tx_max_pending;
1124 static void virtnet_get_drvinfo(struct net_device *dev,
1125 struct ethtool_drvinfo *info)
1127 struct virtnet_info *vi = netdev_priv(dev);
1128 struct virtio_device *vdev = vi->vdev;
1130 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1131 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1132 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1136 /* TODO: Eliminate OOO packets during switching */
1137 static int virtnet_set_channels(struct net_device *dev,
1138 struct ethtool_channels *channels)
1140 struct virtnet_info *vi = netdev_priv(dev);
1141 u16 queue_pairs = channels->combined_count;
1142 int err;
1144 /* We don't support separate rx/tx channels.
1145 * We don't allow setting 'other' channels.
1147 if (channels->rx_count || channels->tx_count || channels->other_count)
1148 return -EINVAL;
1150 if (queue_pairs > vi->max_queue_pairs)
1151 return -EINVAL;
1153 get_online_cpus();
1154 err = virtnet_set_queues(vi, queue_pairs);
1155 if (!err) {
1156 netif_set_real_num_tx_queues(dev, queue_pairs);
1157 netif_set_real_num_rx_queues(dev, queue_pairs);
1159 virtnet_set_affinity(vi);
1161 put_online_cpus();
1163 return err;
1166 static void virtnet_get_channels(struct net_device *dev,
1167 struct ethtool_channels *channels)
1169 struct virtnet_info *vi = netdev_priv(dev);
1171 channels->combined_count = vi->curr_queue_pairs;
1172 channels->max_combined = vi->max_queue_pairs;
1173 channels->max_other = 0;
1174 channels->rx_count = 0;
1175 channels->tx_count = 0;
1176 channels->other_count = 0;
1179 static const struct ethtool_ops virtnet_ethtool_ops = {
1180 .get_drvinfo = virtnet_get_drvinfo,
1181 .get_link = ethtool_op_get_link,
1182 .get_ringparam = virtnet_get_ringparam,
1183 .set_channels = virtnet_set_channels,
1184 .get_channels = virtnet_get_channels,
1187 #define MIN_MTU 68
1188 #define MAX_MTU 65535
1190 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1192 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1193 return -EINVAL;
1194 dev->mtu = new_mtu;
1195 return 0;
1198 /* To avoid contending a lock hold by a vcpu who would exit to host, select the
1199 * txq based on the processor id.
1201 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
1203 int txq;
1204 struct virtnet_info *vi = netdev_priv(dev);
1206 if (skb_rx_queue_recorded(skb)) {
1207 txq = skb_get_rx_queue(skb);
1208 } else {
1209 txq = *__this_cpu_ptr(vi->vq_index);
1210 if (txq == -1)
1211 txq = 0;
1214 while (unlikely(txq >= dev->real_num_tx_queues))
1215 txq -= dev->real_num_tx_queues;
1217 return txq;
1220 static const struct net_device_ops virtnet_netdev = {
1221 .ndo_open = virtnet_open,
1222 .ndo_stop = virtnet_close,
1223 .ndo_start_xmit = start_xmit,
1224 .ndo_validate_addr = eth_validate_addr,
1225 .ndo_set_mac_address = virtnet_set_mac_address,
1226 .ndo_set_rx_mode = virtnet_set_rx_mode,
1227 .ndo_change_mtu = virtnet_change_mtu,
1228 .ndo_get_stats64 = virtnet_stats,
1229 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1230 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1231 .ndo_select_queue = virtnet_select_queue,
1232 #ifdef CONFIG_NET_POLL_CONTROLLER
1233 .ndo_poll_controller = virtnet_netpoll,
1234 #endif
1237 static void virtnet_config_changed_work(struct work_struct *work)
1239 struct virtnet_info *vi =
1240 container_of(work, struct virtnet_info, config_work);
1241 u16 v;
1243 mutex_lock(&vi->config_lock);
1244 if (!vi->config_enable)
1245 goto done;
1247 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
1248 offsetof(struct virtio_net_config, status),
1249 &v) < 0)
1250 goto done;
1252 if (v & VIRTIO_NET_S_ANNOUNCE) {
1253 netdev_notify_peers(vi->dev);
1254 virtnet_ack_link_announce(vi);
1257 /* Ignore unknown (future) status bits */
1258 v &= VIRTIO_NET_S_LINK_UP;
1260 if (vi->status == v)
1261 goto done;
1263 vi->status = v;
1265 if (vi->status & VIRTIO_NET_S_LINK_UP) {
1266 netif_carrier_on(vi->dev);
1267 netif_tx_wake_all_queues(vi->dev);
1268 } else {
1269 netif_carrier_off(vi->dev);
1270 netif_tx_stop_all_queues(vi->dev);
1272 done:
1273 mutex_unlock(&vi->config_lock);
1276 static void virtnet_config_changed(struct virtio_device *vdev)
1278 struct virtnet_info *vi = vdev->priv;
1280 schedule_work(&vi->config_work);
1283 static void virtnet_free_queues(struct virtnet_info *vi)
1285 kfree(vi->rq);
1286 kfree(vi->sq);
1289 static void free_receive_bufs(struct virtnet_info *vi)
1291 int i;
1293 for (i = 0; i < vi->max_queue_pairs; i++) {
1294 while (vi->rq[i].pages)
1295 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1299 static void free_unused_bufs(struct virtnet_info *vi)
1301 void *buf;
1302 int i;
1304 for (i = 0; i < vi->max_queue_pairs; i++) {
1305 struct virtqueue *vq = vi->sq[i].vq;
1306 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1307 dev_kfree_skb(buf);
1310 for (i = 0; i < vi->max_queue_pairs; i++) {
1311 struct virtqueue *vq = vi->rq[i].vq;
1313 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1314 if (vi->mergeable_rx_bufs || vi->big_packets)
1315 give_pages(&vi->rq[i], buf);
1316 else
1317 dev_kfree_skb(buf);
1318 --vi->rq[i].num;
1320 BUG_ON(vi->rq[i].num != 0);
1324 static void virtnet_del_vqs(struct virtnet_info *vi)
1326 struct virtio_device *vdev = vi->vdev;
1328 virtnet_clean_affinity(vi, -1);
1330 vdev->config->del_vqs(vdev);
1332 virtnet_free_queues(vi);
1335 static int virtnet_find_vqs(struct virtnet_info *vi)
1337 vq_callback_t **callbacks;
1338 struct virtqueue **vqs;
1339 int ret = -ENOMEM;
1340 int i, total_vqs;
1341 const char **names;
1343 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1344 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1345 * possible control vq.
1347 total_vqs = vi->max_queue_pairs * 2 +
1348 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1350 /* Allocate space for find_vqs parameters */
1351 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1352 if (!vqs)
1353 goto err_vq;
1354 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1355 if (!callbacks)
1356 goto err_callback;
1357 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1358 if (!names)
1359 goto err_names;
1361 /* Parameters for control virtqueue, if any */
1362 if (vi->has_cvq) {
1363 callbacks[total_vqs - 1] = NULL;
1364 names[total_vqs - 1] = "control";
1367 /* Allocate/initialize parameters for send/receive virtqueues */
1368 for (i = 0; i < vi->max_queue_pairs; i++) {
1369 callbacks[rxq2vq(i)] = skb_recv_done;
1370 callbacks[txq2vq(i)] = skb_xmit_done;
1371 sprintf(vi->rq[i].name, "input.%d", i);
1372 sprintf(vi->sq[i].name, "output.%d", i);
1373 names[rxq2vq(i)] = vi->rq[i].name;
1374 names[txq2vq(i)] = vi->sq[i].name;
1377 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1378 names);
1379 if (ret)
1380 goto err_find;
1382 if (vi->has_cvq) {
1383 vi->cvq = vqs[total_vqs - 1];
1384 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1385 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1388 for (i = 0; i < vi->max_queue_pairs; i++) {
1389 vi->rq[i].vq = vqs[rxq2vq(i)];
1390 vi->sq[i].vq = vqs[txq2vq(i)];
1393 kfree(names);
1394 kfree(callbacks);
1395 kfree(vqs);
1397 return 0;
1399 err_find:
1400 kfree(names);
1401 err_names:
1402 kfree(callbacks);
1403 err_callback:
1404 kfree(vqs);
1405 err_vq:
1406 return ret;
1409 static int virtnet_alloc_queues(struct virtnet_info *vi)
1411 int i;
1413 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1414 if (!vi->sq)
1415 goto err_sq;
1416 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1417 if (!vi->rq)
1418 goto err_rq;
1420 INIT_DELAYED_WORK(&vi->refill, refill_work);
1421 for (i = 0; i < vi->max_queue_pairs; i++) {
1422 vi->rq[i].pages = NULL;
1423 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1424 napi_weight);
1426 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1427 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1430 return 0;
1432 err_rq:
1433 kfree(vi->sq);
1434 err_sq:
1435 return -ENOMEM;
1438 static int init_vqs(struct virtnet_info *vi)
1440 int ret;
1442 /* Allocate send & receive queues */
1443 ret = virtnet_alloc_queues(vi);
1444 if (ret)
1445 goto err;
1447 ret = virtnet_find_vqs(vi);
1448 if (ret)
1449 goto err_free;
1451 get_online_cpus();
1452 virtnet_set_affinity(vi);
1453 put_online_cpus();
1455 return 0;
1457 err_free:
1458 virtnet_free_queues(vi);
1459 err:
1460 return ret;
1463 static int virtnet_probe(struct virtio_device *vdev)
1465 int i, err;
1466 struct net_device *dev;
1467 struct virtnet_info *vi;
1468 u16 max_queue_pairs;
1470 /* Find if host supports multiqueue virtio_net device */
1471 err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
1472 offsetof(struct virtio_net_config,
1473 max_virtqueue_pairs), &max_queue_pairs);
1475 /* We need at least 2 queue's */
1476 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1477 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1478 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1479 max_queue_pairs = 1;
1481 /* Allocate ourselves a network device with room for our info */
1482 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1483 if (!dev)
1484 return -ENOMEM;
1486 /* Set up network device as normal. */
1487 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1488 dev->netdev_ops = &virtnet_netdev;
1489 dev->features = NETIF_F_HIGHDMA;
1491 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1492 SET_NETDEV_DEV(dev, &vdev->dev);
1494 /* Do we support "hardware" checksums? */
1495 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1496 /* This opens up the world of extra features. */
1497 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1498 if (csum)
1499 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1501 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1502 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1503 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1505 /* Individual feature bits: what can host handle? */
1506 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1507 dev->hw_features |= NETIF_F_TSO;
1508 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1509 dev->hw_features |= NETIF_F_TSO6;
1510 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1511 dev->hw_features |= NETIF_F_TSO_ECN;
1512 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1513 dev->hw_features |= NETIF_F_UFO;
1515 if (gso)
1516 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1517 /* (!csum && gso) case will be fixed by register_netdev() */
1520 dev->vlan_features = dev->features;
1522 /* Configuration may specify what MAC to use. Otherwise random. */
1523 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1524 offsetof(struct virtio_net_config, mac),
1525 dev->dev_addr, dev->addr_len) < 0)
1526 eth_hw_addr_random(dev);
1528 /* Set up our device-specific information */
1529 vi = netdev_priv(dev);
1530 vi->dev = dev;
1531 vi->vdev = vdev;
1532 vdev->priv = vi;
1533 vi->stats = alloc_percpu(struct virtnet_stats);
1534 err = -ENOMEM;
1535 if (vi->stats == NULL)
1536 goto free;
1538 vi->vq_index = alloc_percpu(int);
1539 if (vi->vq_index == NULL)
1540 goto free_stats;
1542 mutex_init(&vi->config_lock);
1543 vi->config_enable = true;
1544 INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1546 /* If we can receive ANY GSO packets, we must allocate large ones. */
1547 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1548 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1549 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1550 vi->big_packets = true;
1552 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1553 vi->mergeable_rx_bufs = true;
1555 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1556 vi->has_cvq = true;
1558 /* Use single tx/rx queue pair as default */
1559 vi->curr_queue_pairs = 1;
1560 vi->max_queue_pairs = max_queue_pairs;
1562 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1563 err = init_vqs(vi);
1564 if (err)
1565 goto free_index;
1567 netif_set_real_num_tx_queues(dev, 1);
1568 netif_set_real_num_rx_queues(dev, 1);
1570 err = register_netdev(dev);
1571 if (err) {
1572 pr_debug("virtio_net: registering device failed\n");
1573 goto free_vqs;
1576 /* Last of all, set up some receive buffers. */
1577 for (i = 0; i < vi->curr_queue_pairs; i++) {
1578 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1580 /* If we didn't even get one input buffer, we're useless. */
1581 if (vi->rq[i].num == 0) {
1582 free_unused_bufs(vi);
1583 err = -ENOMEM;
1584 goto free_recv_bufs;
1588 vi->nb.notifier_call = &virtnet_cpu_callback;
1589 err = register_hotcpu_notifier(&vi->nb);
1590 if (err) {
1591 pr_debug("virtio_net: registering cpu notifier failed\n");
1592 goto free_recv_bufs;
1595 /* Assume link up if device can't report link status,
1596 otherwise get link status from config. */
1597 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1598 netif_carrier_off(dev);
1599 schedule_work(&vi->config_work);
1600 } else {
1601 vi->status = VIRTIO_NET_S_LINK_UP;
1602 netif_carrier_on(dev);
1605 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1606 dev->name, max_queue_pairs);
1608 return 0;
1610 free_recv_bufs:
1611 free_receive_bufs(vi);
1612 unregister_netdev(dev);
1613 free_vqs:
1614 cancel_delayed_work_sync(&vi->refill);
1615 virtnet_del_vqs(vi);
1616 free_index:
1617 free_percpu(vi->vq_index);
1618 free_stats:
1619 free_percpu(vi->stats);
1620 free:
1621 free_netdev(dev);
1622 return err;
1625 static void remove_vq_common(struct virtnet_info *vi)
1627 vi->vdev->config->reset(vi->vdev);
1629 /* Free unused buffers in both send and recv, if any. */
1630 free_unused_bufs(vi);
1632 free_receive_bufs(vi);
1634 virtnet_del_vqs(vi);
1637 static void virtnet_remove(struct virtio_device *vdev)
1639 struct virtnet_info *vi = vdev->priv;
1641 unregister_hotcpu_notifier(&vi->nb);
1643 /* Prevent config work handler from accessing the device. */
1644 mutex_lock(&vi->config_lock);
1645 vi->config_enable = false;
1646 mutex_unlock(&vi->config_lock);
1648 unregister_netdev(vi->dev);
1650 remove_vq_common(vi);
1652 flush_work(&vi->config_work);
1654 free_percpu(vi->vq_index);
1655 free_percpu(vi->stats);
1656 free_netdev(vi->dev);
1659 #ifdef CONFIG_PM
1660 static int virtnet_freeze(struct virtio_device *vdev)
1662 struct virtnet_info *vi = vdev->priv;
1663 int i;
1665 /* Prevent config work handler from accessing the device */
1666 mutex_lock(&vi->config_lock);
1667 vi->config_enable = false;
1668 mutex_unlock(&vi->config_lock);
1670 netif_device_detach(vi->dev);
1671 cancel_delayed_work_sync(&vi->refill);
1673 if (netif_running(vi->dev))
1674 for (i = 0; i < vi->max_queue_pairs; i++) {
1675 napi_disable(&vi->rq[i].napi);
1676 netif_napi_del(&vi->rq[i].napi);
1679 remove_vq_common(vi);
1681 flush_work(&vi->config_work);
1683 return 0;
1686 static int virtnet_restore(struct virtio_device *vdev)
1688 struct virtnet_info *vi = vdev->priv;
1689 int err, i;
1691 err = init_vqs(vi);
1692 if (err)
1693 return err;
1695 if (netif_running(vi->dev))
1696 for (i = 0; i < vi->max_queue_pairs; i++)
1697 virtnet_napi_enable(&vi->rq[i]);
1699 netif_device_attach(vi->dev);
1701 for (i = 0; i < vi->curr_queue_pairs; i++)
1702 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1703 schedule_delayed_work(&vi->refill, 0);
1705 mutex_lock(&vi->config_lock);
1706 vi->config_enable = true;
1707 mutex_unlock(&vi->config_lock);
1709 virtnet_set_queues(vi, vi->curr_queue_pairs);
1711 return 0;
1713 #endif
1715 static struct virtio_device_id id_table[] = {
1716 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1717 { 0 },
1720 static unsigned int features[] = {
1721 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1722 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1723 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1724 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1725 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1726 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1727 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1728 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1729 VIRTIO_NET_F_CTRL_MAC_ADDR,
1732 static struct virtio_driver virtio_net_driver = {
1733 .feature_table = features,
1734 .feature_table_size = ARRAY_SIZE(features),
1735 .driver.name = KBUILD_MODNAME,
1736 .driver.owner = THIS_MODULE,
1737 .id_table = id_table,
1738 .probe = virtnet_probe,
1739 .remove = virtnet_remove,
1740 .config_changed = virtnet_config_changed,
1741 #ifdef CONFIG_PM
1742 .freeze = virtnet_freeze,
1743 .restore = virtnet_restore,
1744 #endif
1747 module_virtio_driver(virtio_net_driver);
1749 MODULE_DEVICE_TABLE(virtio, id_table);
1750 MODULE_DESCRIPTION("Virtio network driver");
1751 MODULE_LICENSE("GPL");