virtio: add virtio IDs file
[linux-2.6.git] / drivers / net / virtio_net.c
1 /* A simple 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_ids.h>
26 #include <linux/virtio_net.h>
27 #include <linux/scatterlist.h>
28 #include <linux/if_vlan.h>
29
30 static int napi_weight = 128;
31 module_param(napi_weight, int, 0444);
32
33 static int csum = 1, gso = 1;
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
43 struct virtnet_info
44 {
45         struct virtio_device *vdev;
46         struct virtqueue *rvq, *svq, *cvq;
47         struct net_device *dev;
48         struct napi_struct napi;
49         unsigned int status;
50
51         /* The skb we couldn't send because buffers were full. */
52         struct sk_buff *last_xmit_skb;
53
54         /* If we need to free in a timer, this is it. */
55         struct timer_list xmit_free_timer;
56
57         /* Number of input buffers, and max we've ever had. */
58         unsigned int num, max;
59
60         /* For cleaning up after transmission. */
61         struct tasklet_struct tasklet;
62         bool free_in_tasklet;
63
64         /* I like... big packets and I cannot lie! */
65         bool big_packets;
66
67         /* Host will merge rx buffers for big packets (shake it! shake it!) */
68         bool mergeable_rx_bufs;
69
70         /* Receive & send queues. */
71         struct sk_buff_head recv;
72         struct sk_buff_head send;
73
74         /* Work struct for refilling if we run low on memory. */
75         struct delayed_work refill;
76
77         /* Chain pages by the private ptr. */
78         struct page *pages;
79 };
80
81 static inline void *skb_vnet_hdr(struct sk_buff *skb)
82 {
83         return (struct virtio_net_hdr *)skb->cb;
84 }
85
86 static void give_a_page(struct virtnet_info *vi, struct page *page)
87 {
88         page->private = (unsigned long)vi->pages;
89         vi->pages = page;
90 }
91
92 static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb)
93 {
94         unsigned int i;
95
96         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
97                 give_a_page(vi, skb_shinfo(skb)->frags[i].page);
98         skb_shinfo(skb)->nr_frags = 0;
99         skb->data_len = 0;
100 }
101
102 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
103 {
104         struct page *p = vi->pages;
105
106         if (p)
107                 vi->pages = (struct page *)p->private;
108         else
109                 p = alloc_page(gfp_mask);
110         return p;
111 }
112
113 static void skb_xmit_done(struct virtqueue *svq)
114 {
115         struct virtnet_info *vi = svq->vdev->priv;
116
117         /* Suppress further interrupts. */
118         svq->vq_ops->disable_cb(svq);
119
120         /* We were probably waiting for more output buffers. */
121         netif_wake_queue(vi->dev);
122
123         /* Make sure we re-xmit last_xmit_skb: if there are no more packets
124          * queued, start_xmit won't be called. */
125         tasklet_schedule(&vi->tasklet);
126 }
127
128 static void receive_skb(struct net_device *dev, struct sk_buff *skb,
129                         unsigned len)
130 {
131         struct virtnet_info *vi = netdev_priv(dev);
132         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
133         int err;
134         int i;
135
136         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
137                 pr_debug("%s: short packet %i\n", dev->name, len);
138                 dev->stats.rx_length_errors++;
139                 goto drop;
140         }
141
142         if (vi->mergeable_rx_bufs) {
143                 struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
144                 unsigned int copy;
145                 char *p = page_address(skb_shinfo(skb)->frags[0].page);
146
147                 if (len > PAGE_SIZE)
148                         len = PAGE_SIZE;
149                 len -= sizeof(struct virtio_net_hdr_mrg_rxbuf);
150
151                 memcpy(hdr, p, sizeof(*mhdr));
152                 p += sizeof(*mhdr);
153
154                 copy = len;
155                 if (copy > skb_tailroom(skb))
156                         copy = skb_tailroom(skb);
157
158                 memcpy(skb_put(skb, copy), p, copy);
159
160                 len -= copy;
161
162                 if (!len) {
163                         give_a_page(vi, skb_shinfo(skb)->frags[0].page);
164                         skb_shinfo(skb)->nr_frags--;
165                 } else {
166                         skb_shinfo(skb)->frags[0].page_offset +=
167                                 sizeof(*mhdr) + copy;
168                         skb_shinfo(skb)->frags[0].size = len;
169                         skb->data_len += len;
170                         skb->len += len;
171                 }
172
173                 while (--mhdr->num_buffers) {
174                         struct sk_buff *nskb;
175
176                         i = skb_shinfo(skb)->nr_frags;
177                         if (i >= MAX_SKB_FRAGS) {
178                                 pr_debug("%s: packet too long %d\n", dev->name,
179                                          len);
180                                 dev->stats.rx_length_errors++;
181                                 goto drop;
182                         }
183
184                         nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
185                         if (!nskb) {
186                                 pr_debug("%s: rx error: %d buffers missing\n",
187                                          dev->name, mhdr->num_buffers);
188                                 dev->stats.rx_length_errors++;
189                                 goto drop;
190                         }
191
192                         __skb_unlink(nskb, &vi->recv);
193                         vi->num--;
194
195                         skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0];
196                         skb_shinfo(nskb)->nr_frags = 0;
197                         kfree_skb(nskb);
198
199                         if (len > PAGE_SIZE)
200                                 len = PAGE_SIZE;
201
202                         skb_shinfo(skb)->frags[i].size = len;
203                         skb_shinfo(skb)->nr_frags++;
204                         skb->data_len += len;
205                         skb->len += len;
206                 }
207         } else {
208                 len -= sizeof(struct virtio_net_hdr);
209
210                 if (len <= MAX_PACKET_LEN)
211                         trim_pages(vi, skb);
212
213                 err = pskb_trim(skb, len);
214                 if (err) {
215                         pr_debug("%s: pskb_trim failed %i %d\n", dev->name,
216                                  len, err);
217                         dev->stats.rx_dropped++;
218                         goto drop;
219                 }
220         }
221
222         skb->truesize += skb->data_len;
223         dev->stats.rx_bytes += skb->len;
224         dev->stats.rx_packets++;
225
226         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
227                 pr_debug("Needs csum!\n");
228                 if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
229                         goto frame_err;
230         }
231
232         skb->protocol = eth_type_trans(skb, dev);
233         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
234                  ntohs(skb->protocol), skb->len, skb->pkt_type);
235
236         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
237                 pr_debug("GSO!\n");
238                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
239                 case VIRTIO_NET_HDR_GSO_TCPV4:
240                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
241                         break;
242                 case VIRTIO_NET_HDR_GSO_UDP:
243                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
244                         break;
245                 case VIRTIO_NET_HDR_GSO_TCPV6:
246                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
247                         break;
248                 default:
249                         if (net_ratelimit())
250                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
251                                        dev->name, hdr->gso_type);
252                         goto frame_err;
253                 }
254
255                 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
256                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
257
258                 skb_shinfo(skb)->gso_size = hdr->gso_size;
259                 if (skb_shinfo(skb)->gso_size == 0) {
260                         if (net_ratelimit())
261                                 printk(KERN_WARNING "%s: zero gso size.\n",
262                                        dev->name);
263                         goto frame_err;
264                 }
265
266                 /* Header must be checked, and gso_segs computed. */
267                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
268                 skb_shinfo(skb)->gso_segs = 0;
269         }
270
271         netif_receive_skb(skb);
272         return;
273
274 frame_err:
275         dev->stats.rx_frame_errors++;
276 drop:
277         dev_kfree_skb(skb);
278 }
279
280 static bool try_fill_recv_maxbufs(struct virtnet_info *vi, gfp_t gfp)
281 {
282         struct sk_buff *skb;
283         struct scatterlist sg[2+MAX_SKB_FRAGS];
284         int num, err, i;
285         bool oom = false;
286
287         sg_init_table(sg, 2+MAX_SKB_FRAGS);
288         for (;;) {
289                 struct virtio_net_hdr *hdr;
290
291                 skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN + NET_IP_ALIGN);
292                 if (unlikely(!skb)) {
293                         oom = true;
294                         break;
295                 }
296
297                 skb_reserve(skb, NET_IP_ALIGN);
298                 skb_put(skb, MAX_PACKET_LEN);
299
300                 hdr = skb_vnet_hdr(skb);
301                 sg_set_buf(sg, hdr, sizeof(*hdr));
302
303                 if (vi->big_packets) {
304                         for (i = 0; i < MAX_SKB_FRAGS; i++) {
305                                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
306                                 f->page = get_a_page(vi, gfp);
307                                 if (!f->page)
308                                         break;
309
310                                 f->page_offset = 0;
311                                 f->size = PAGE_SIZE;
312
313                                 skb->data_len += PAGE_SIZE;
314                                 skb->len += PAGE_SIZE;
315
316                                 skb_shinfo(skb)->nr_frags++;
317                         }
318                 }
319
320                 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
321                 skb_queue_head(&vi->recv, skb);
322
323                 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
324                 if (err < 0) {
325                         skb_unlink(skb, &vi->recv);
326                         trim_pages(vi, skb);
327                         kfree_skb(skb);
328                         break;
329                 }
330                 vi->num++;
331         }
332         if (unlikely(vi->num > vi->max))
333                 vi->max = vi->num;
334         vi->rvq->vq_ops->kick(vi->rvq);
335         return !oom;
336 }
337
338 /* Returns false if we couldn't fill entirely (OOM). */
339 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
340 {
341         struct sk_buff *skb;
342         struct scatterlist sg[1];
343         int err;
344         bool oom = false;
345
346         if (!vi->mergeable_rx_bufs)
347                 return try_fill_recv_maxbufs(vi, gfp);
348
349         for (;;) {
350                 skb_frag_t *f;
351
352                 skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN);
353                 if (unlikely(!skb)) {
354                         oom = true;
355                         break;
356                 }
357
358                 skb_reserve(skb, NET_IP_ALIGN);
359
360                 f = &skb_shinfo(skb)->frags[0];
361                 f->page = get_a_page(vi, gfp);
362                 if (!f->page) {
363                         oom = true;
364                         kfree_skb(skb);
365                         break;
366                 }
367
368                 f->page_offset = 0;
369                 f->size = PAGE_SIZE;
370
371                 skb_shinfo(skb)->nr_frags++;
372
373                 sg_init_one(sg, page_address(f->page), PAGE_SIZE);
374                 skb_queue_head(&vi->recv, skb);
375
376                 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb);
377                 if (err < 0) {
378                         skb_unlink(skb, &vi->recv);
379                         kfree_skb(skb);
380                         break;
381                 }
382                 vi->num++;
383         }
384         if (unlikely(vi->num > vi->max))
385                 vi->max = vi->num;
386         vi->rvq->vq_ops->kick(vi->rvq);
387         return !oom;
388 }
389
390 static void skb_recv_done(struct virtqueue *rvq)
391 {
392         struct virtnet_info *vi = rvq->vdev->priv;
393         /* Schedule NAPI, Suppress further interrupts if successful. */
394         if (napi_schedule_prep(&vi->napi)) {
395                 rvq->vq_ops->disable_cb(rvq);
396                 __napi_schedule(&vi->napi);
397         }
398 }
399
400 static void refill_work(struct work_struct *work)
401 {
402         struct virtnet_info *vi;
403         bool still_empty;
404
405         vi = container_of(work, struct virtnet_info, refill.work);
406         napi_disable(&vi->napi);
407         try_fill_recv(vi, GFP_KERNEL);
408         still_empty = (vi->num == 0);
409         napi_enable(&vi->napi);
410
411         /* In theory, this can happen: if we don't get any buffers in
412          * we will *never* try to fill again. */
413         if (still_empty)
414                 schedule_delayed_work(&vi->refill, HZ/2);
415 }
416
417 static int virtnet_poll(struct napi_struct *napi, int budget)
418 {
419         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
420         struct sk_buff *skb = NULL;
421         unsigned int len, received = 0;
422
423 again:
424         while (received < budget &&
425                (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
426                 __skb_unlink(skb, &vi->recv);
427                 receive_skb(vi->dev, skb, len);
428                 vi->num--;
429                 received++;
430         }
431
432         if (vi->num < vi->max / 2) {
433                 if (!try_fill_recv(vi, GFP_ATOMIC))
434                         schedule_delayed_work(&vi->refill, 0);
435         }
436
437         /* Out of packets? */
438         if (received < budget) {
439                 napi_complete(napi);
440                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
441                     && napi_schedule_prep(napi)) {
442                         vi->rvq->vq_ops->disable_cb(vi->rvq);
443                         __napi_schedule(napi);
444                         goto again;
445                 }
446         }
447
448         return received;
449 }
450
451 static void free_old_xmit_skbs(struct virtnet_info *vi)
452 {
453         struct sk_buff *skb;
454         unsigned int len;
455
456         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
457                 pr_debug("Sent skb %p\n", skb);
458                 __skb_unlink(skb, &vi->send);
459                 vi->dev->stats.tx_bytes += skb->len;
460                 vi->dev->stats.tx_packets++;
461                 kfree_skb(skb);
462         }
463 }
464
465 /* If the virtio transport doesn't always notify us when all in-flight packets
466  * are consumed, we fall back to using this function on a timer to free them. */
467 static void xmit_free(unsigned long data)
468 {
469         struct virtnet_info *vi = (void *)data;
470
471         netif_tx_lock(vi->dev);
472
473         free_old_xmit_skbs(vi);
474
475         if (!skb_queue_empty(&vi->send))
476                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
477
478         netif_tx_unlock(vi->dev);
479 }
480
481 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
482 {
483         int num, err;
484         struct scatterlist sg[2+MAX_SKB_FRAGS];
485         struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
486         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
487         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
488
489         sg_init_table(sg, 2+MAX_SKB_FRAGS);
490
491         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
492
493         if (skb->ip_summed == CHECKSUM_PARTIAL) {
494                 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
495                 hdr->csum_start = skb->csum_start - skb_headroom(skb);
496                 hdr->csum_offset = skb->csum_offset;
497         } else {
498                 hdr->flags = 0;
499                 hdr->csum_offset = hdr->csum_start = 0;
500         }
501
502         if (skb_is_gso(skb)) {
503                 hdr->hdr_len = skb_headlen(skb);
504                 hdr->gso_size = skb_shinfo(skb)->gso_size;
505                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
506                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
507                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
508                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
509                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
510                         hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
511                 else
512                         BUG();
513                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
514                         hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
515         } else {
516                 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
517                 hdr->gso_size = hdr->hdr_len = 0;
518         }
519
520         mhdr->num_buffers = 0;
521
522         /* Encode metadata header at front. */
523         if (vi->mergeable_rx_bufs)
524                 sg_set_buf(sg, mhdr, sizeof(*mhdr));
525         else
526                 sg_set_buf(sg, hdr, sizeof(*hdr));
527
528         num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
529
530         err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
531         if (err >= 0 && !vi->free_in_tasklet)
532                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
533
534         return err;
535 }
536
537 static void xmit_tasklet(unsigned long data)
538 {
539         struct virtnet_info *vi = (void *)data;
540
541         netif_tx_lock_bh(vi->dev);
542         if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) >= 0) {
543                 vi->svq->vq_ops->kick(vi->svq);
544                 vi->last_xmit_skb = NULL;
545         }
546         if (vi->free_in_tasklet)
547                 free_old_xmit_skbs(vi);
548         netif_tx_unlock_bh(vi->dev);
549 }
550
551 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
552 {
553         struct virtnet_info *vi = netdev_priv(dev);
554
555 again:
556         /* Free up any pending old buffers before queueing new ones. */
557         free_old_xmit_skbs(vi);
558
559         /* If we has a buffer left over from last time, send it now. */
560         if (unlikely(vi->last_xmit_skb) &&
561             xmit_skb(vi, vi->last_xmit_skb) < 0)
562                 goto stop_queue;
563
564         vi->last_xmit_skb = NULL;
565
566         /* Put new one in send queue and do transmit */
567         if (likely(skb)) {
568                 __skb_queue_head(&vi->send, skb);
569                 if (xmit_skb(vi, skb) < 0) {
570                         vi->last_xmit_skb = skb;
571                         skb = NULL;
572                         goto stop_queue;
573                 }
574         }
575 done:
576         vi->svq->vq_ops->kick(vi->svq);
577         return NETDEV_TX_OK;
578
579 stop_queue:
580         pr_debug("%s: virtio not prepared to send\n", dev->name);
581         netif_stop_queue(dev);
582
583         /* Activate callback for using skbs: if this returns false it
584          * means some were used in the meantime. */
585         if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
586                 vi->svq->vq_ops->disable_cb(vi->svq);
587                 netif_start_queue(dev);
588                 goto again;
589         }
590         if (skb) {
591                 /* Drop this skb: we only queue one. */
592                 vi->dev->stats.tx_dropped++;
593                 kfree_skb(skb);
594         }
595         goto done;
596 }
597
598 static int virtnet_set_mac_address(struct net_device *dev, void *p)
599 {
600         struct virtnet_info *vi = netdev_priv(dev);
601         struct virtio_device *vdev = vi->vdev;
602         int ret;
603
604         ret = eth_mac_addr(dev, p);
605         if (ret)
606                 return ret;
607
608         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
609                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
610                                   dev->dev_addr, dev->addr_len);
611
612         return 0;
613 }
614
615 #ifdef CONFIG_NET_POLL_CONTROLLER
616 static void virtnet_netpoll(struct net_device *dev)
617 {
618         struct virtnet_info *vi = netdev_priv(dev);
619
620         napi_schedule(&vi->napi);
621 }
622 #endif
623
624 static int virtnet_open(struct net_device *dev)
625 {
626         struct virtnet_info *vi = netdev_priv(dev);
627
628         napi_enable(&vi->napi);
629
630         /* If all buffers were filled by other side before we napi_enabled, we
631          * won't get another interrupt, so process any outstanding packets
632          * now.  virtnet_poll wants re-enable the queue, so we disable here.
633          * We synchronize against interrupts via NAPI_STATE_SCHED */
634         if (napi_schedule_prep(&vi->napi)) {
635                 vi->rvq->vq_ops->disable_cb(vi->rvq);
636                 __napi_schedule(&vi->napi);
637         }
638         return 0;
639 }
640
641 /*
642  * Send command via the control virtqueue and check status.  Commands
643  * supported by the hypervisor, as indicated by feature bits, should
644  * never fail unless improperly formated.
645  */
646 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
647                                  struct scatterlist *data, int out, int in)
648 {
649         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
650         struct virtio_net_ctrl_hdr ctrl;
651         virtio_net_ctrl_ack status = ~0;
652         unsigned int tmp;
653         int i;
654
655         /* Caller should know better */
656         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
657                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
658
659         out++; /* Add header */
660         in++; /* Add return status */
661
662         ctrl.class = class;
663         ctrl.cmd = cmd;
664
665         sg_init_table(sg, out + in);
666
667         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
668         for_each_sg(data, s, out + in - 2, i)
669                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
670         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
671
672         BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0);
673
674         vi->cvq->vq_ops->kick(vi->cvq);
675
676         /*
677          * Spin for a response, the kick causes an ioport write, trapping
678          * into the hypervisor, so the request should be handled immediately.
679          */
680         while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
681                 cpu_relax();
682
683         return status == VIRTIO_NET_OK;
684 }
685
686 static int virtnet_close(struct net_device *dev)
687 {
688         struct virtnet_info *vi = netdev_priv(dev);
689
690         napi_disable(&vi->napi);
691
692         return 0;
693 }
694
695 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
696 {
697         struct virtnet_info *vi = netdev_priv(dev);
698         struct virtio_device *vdev = vi->vdev;
699
700         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
701                 return -ENOSYS;
702
703         return ethtool_op_set_tx_hw_csum(dev, data);
704 }
705
706 static void virtnet_set_rx_mode(struct net_device *dev)
707 {
708         struct virtnet_info *vi = netdev_priv(dev);
709         struct scatterlist sg[2];
710         u8 promisc, allmulti;
711         struct virtio_net_ctrl_mac *mac_data;
712         struct dev_addr_list *addr;
713         struct netdev_hw_addr *ha;
714         void *buf;
715         int i;
716
717         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
718         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
719                 return;
720
721         promisc = ((dev->flags & IFF_PROMISC) != 0);
722         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
723
724         sg_init_one(sg, &promisc, sizeof(promisc));
725
726         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
727                                   VIRTIO_NET_CTRL_RX_PROMISC,
728                                   sg, 1, 0))
729                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
730                          promisc ? "en" : "dis");
731
732         sg_init_one(sg, &allmulti, sizeof(allmulti));
733
734         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
735                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
736                                   sg, 1, 0))
737                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
738                          allmulti ? "en" : "dis");
739
740         /* MAC filter - use one buffer for both lists */
741         mac_data = buf = kzalloc(((dev->uc.count + dev->mc_count) * ETH_ALEN) +
742                                  (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
743         if (!buf) {
744                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
745                 return;
746         }
747
748         sg_init_table(sg, 2);
749
750         /* Store the unicast list and count in the front of the buffer */
751         mac_data->entries = dev->uc.count;
752         i = 0;
753         list_for_each_entry(ha, &dev->uc.list, list)
754                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
755
756         sg_set_buf(&sg[0], mac_data,
757                    sizeof(mac_data->entries) + (dev->uc.count * ETH_ALEN));
758
759         /* multicast list and count fill the end */
760         mac_data = (void *)&mac_data->macs[dev->uc.count][0];
761
762         mac_data->entries = dev->mc_count;
763         addr = dev->mc_list;
764         for (i = 0; i < dev->mc_count; i++, addr = addr->next)
765                 memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN);
766
767         sg_set_buf(&sg[1], mac_data,
768                    sizeof(mac_data->entries) + (dev->mc_count * ETH_ALEN));
769
770         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
771                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
772                                   sg, 2, 0))
773                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
774
775         kfree(buf);
776 }
777
778 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
779 {
780         struct virtnet_info *vi = netdev_priv(dev);
781         struct scatterlist sg;
782
783         sg_init_one(&sg, &vid, sizeof(vid));
784
785         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
786                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
787                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
788 }
789
790 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
791 {
792         struct virtnet_info *vi = netdev_priv(dev);
793         struct scatterlist sg;
794
795         sg_init_one(&sg, &vid, sizeof(vid));
796
797         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
798                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
799                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
800 }
801
802 static const struct ethtool_ops virtnet_ethtool_ops = {
803         .set_tx_csum = virtnet_set_tx_csum,
804         .set_sg = ethtool_op_set_sg,
805         .set_tso = ethtool_op_set_tso,
806         .set_ufo = ethtool_op_set_ufo,
807         .get_link = ethtool_op_get_link,
808 };
809
810 #define MIN_MTU 68
811 #define MAX_MTU 65535
812
813 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
814 {
815         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
816                 return -EINVAL;
817         dev->mtu = new_mtu;
818         return 0;
819 }
820
821 static const struct net_device_ops virtnet_netdev = {
822         .ndo_open            = virtnet_open,
823         .ndo_stop            = virtnet_close,
824         .ndo_start_xmit      = start_xmit,
825         .ndo_validate_addr   = eth_validate_addr,
826         .ndo_set_mac_address = virtnet_set_mac_address,
827         .ndo_set_rx_mode     = virtnet_set_rx_mode,
828         .ndo_change_mtu      = virtnet_change_mtu,
829         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
830         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
831 #ifdef CONFIG_NET_POLL_CONTROLLER
832         .ndo_poll_controller = virtnet_netpoll,
833 #endif
834 };
835
836 static void virtnet_update_status(struct virtnet_info *vi)
837 {
838         u16 v;
839
840         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
841                 return;
842
843         vi->vdev->config->get(vi->vdev,
844                               offsetof(struct virtio_net_config, status),
845                               &v, sizeof(v));
846
847         /* Ignore unknown (future) status bits */
848         v &= VIRTIO_NET_S_LINK_UP;
849
850         if (vi->status == v)
851                 return;
852
853         vi->status = v;
854
855         if (vi->status & VIRTIO_NET_S_LINK_UP) {
856                 netif_carrier_on(vi->dev);
857                 netif_wake_queue(vi->dev);
858         } else {
859                 netif_carrier_off(vi->dev);
860                 netif_stop_queue(vi->dev);
861         }
862 }
863
864 static void virtnet_config_changed(struct virtio_device *vdev)
865 {
866         struct virtnet_info *vi = vdev->priv;
867
868         virtnet_update_status(vi);
869 }
870
871 static int virtnet_probe(struct virtio_device *vdev)
872 {
873         int err;
874         struct net_device *dev;
875         struct virtnet_info *vi;
876         struct virtqueue *vqs[3];
877         vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
878         const char *names[] = { "input", "output", "control" };
879         int nvqs;
880
881         /* Allocate ourselves a network device with room for our info */
882         dev = alloc_etherdev(sizeof(struct virtnet_info));
883         if (!dev)
884                 return -ENOMEM;
885
886         /* Set up network device as normal. */
887         dev->netdev_ops = &virtnet_netdev;
888         dev->features = NETIF_F_HIGHDMA;
889         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
890         SET_NETDEV_DEV(dev, &vdev->dev);
891
892         /* Do we support "hardware" checksums? */
893         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
894                 /* This opens up the world of extra features. */
895                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
896                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
897                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
898                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
899                 }
900                 /* Individual feature bits: what can host handle? */
901                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
902                         dev->features |= NETIF_F_TSO;
903                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
904                         dev->features |= NETIF_F_TSO6;
905                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
906                         dev->features |= NETIF_F_TSO_ECN;
907                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
908                         dev->features |= NETIF_F_UFO;
909         }
910
911         /* Configuration may specify what MAC to use.  Otherwise random. */
912         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
913                 vdev->config->get(vdev,
914                                   offsetof(struct virtio_net_config, mac),
915                                   dev->dev_addr, dev->addr_len);
916         } else
917                 random_ether_addr(dev->dev_addr);
918
919         /* Set up our device-specific information */
920         vi = netdev_priv(dev);
921         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
922         vi->dev = dev;
923         vi->vdev = vdev;
924         vdev->priv = vi;
925         vi->pages = NULL;
926         INIT_DELAYED_WORK(&vi->refill, refill_work);
927
928         /* If they give us a callback when all buffers are done, we don't need
929          * the timer. */
930         vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
931
932         /* If we can receive ANY GSO packets, we must allocate large ones. */
933         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
934             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
935             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
936                 vi->big_packets = true;
937
938         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
939                 vi->mergeable_rx_bufs = true;
940
941         /* We expect two virtqueues, receive then send,
942          * and optionally control. */
943         nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
944
945         err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
946         if (err)
947                 goto free;
948
949         vi->rvq = vqs[0];
950         vi->svq = vqs[1];
951
952         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
953                 vi->cvq = vqs[2];
954
955                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
956                         dev->features |= NETIF_F_HW_VLAN_FILTER;
957         }
958
959         /* Initialize our empty receive and send queues. */
960         skb_queue_head_init(&vi->recv);
961         skb_queue_head_init(&vi->send);
962
963         tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
964
965         if (!vi->free_in_tasklet)
966                 setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
967
968         err = register_netdev(dev);
969         if (err) {
970                 pr_debug("virtio_net: registering device failed\n");
971                 goto free_vqs;
972         }
973
974         /* Last of all, set up some receive buffers. */
975         try_fill_recv(vi, GFP_KERNEL);
976
977         /* If we didn't even get one input buffer, we're useless. */
978         if (vi->num == 0) {
979                 err = -ENOMEM;
980                 goto unregister;
981         }
982
983         vi->status = VIRTIO_NET_S_LINK_UP;
984         virtnet_update_status(vi);
985         netif_carrier_on(dev);
986
987         pr_debug("virtnet: registered device %s\n", dev->name);
988         return 0;
989
990 unregister:
991         unregister_netdev(dev);
992         cancel_delayed_work_sync(&vi->refill);
993 free_vqs:
994         vdev->config->del_vqs(vdev);
995 free:
996         free_netdev(dev);
997         return err;
998 }
999
1000 static void virtnet_remove(struct virtio_device *vdev)
1001 {
1002         struct virtnet_info *vi = vdev->priv;
1003         struct sk_buff *skb;
1004
1005         /* Stop all the virtqueues. */
1006         vdev->config->reset(vdev);
1007
1008         if (!vi->free_in_tasklet)
1009                 del_timer_sync(&vi->xmit_free_timer);
1010
1011         /* Free our skbs in send and recv queues, if any. */
1012         while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
1013                 kfree_skb(skb);
1014                 vi->num--;
1015         }
1016         __skb_queue_purge(&vi->send);
1017
1018         BUG_ON(vi->num != 0);
1019
1020         unregister_netdev(vi->dev);
1021         cancel_delayed_work_sync(&vi->refill);
1022
1023         vdev->config->del_vqs(vi->vdev);
1024
1025         while (vi->pages)
1026                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1027
1028         free_netdev(vi->dev);
1029 }
1030
1031 static struct virtio_device_id id_table[] = {
1032         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1033         { 0 },
1034 };
1035
1036 static unsigned int features[] = {
1037         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1038         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1039         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1040         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1041         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1042         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1043         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1044         VIRTIO_F_NOTIFY_ON_EMPTY,
1045 };
1046
1047 static struct virtio_driver virtio_net = {
1048         .feature_table = features,
1049         .feature_table_size = ARRAY_SIZE(features),
1050         .driver.name =  KBUILD_MODNAME,
1051         .driver.owner = THIS_MODULE,
1052         .id_table =     id_table,
1053         .probe =        virtnet_probe,
1054         .remove =       __devexit_p(virtnet_remove),
1055         .config_changed = virtnet_config_changed,
1056 };
1057
1058 static int __init init(void)
1059 {
1060         return register_virtio_driver(&virtio_net);
1061 }
1062
1063 static void __exit fini(void)
1064 {
1065         unregister_virtio_driver(&virtio_net);
1066 }
1067 module_init(init);
1068 module_exit(fini);
1069
1070 MODULE_DEVICE_TABLE(virtio, id_table);
1071 MODULE_DESCRIPTION("Virtio network driver");
1072 MODULE_LICENSE("GPL");