virtio: Recycle unused recv buffer pages for large skbs in net driver
[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_net.h>
26 #include <linux/scatterlist.h>
27
28 static int napi_weight = 128;
29 module_param(napi_weight, int, 0444);
30
31 static int csum = 1, gso = 1;
32 module_param(csum, bool, 0444);
33 module_param(gso, bool, 0444);
34
35 /* FIXME: MTU in config. */
36 #define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
37
38 struct virtnet_info
39 {
40         struct virtio_device *vdev;
41         struct virtqueue *rvq, *svq;
42         struct net_device *dev;
43         struct napi_struct napi;
44
45         /* The skb we couldn't send because buffers were full. */
46         struct sk_buff *last_xmit_skb;
47
48         /* If we need to free in a timer, this is it. */
49         struct timer_list xmit_free_timer;
50
51         /* Number of input buffers, and max we've ever had. */
52         unsigned int num, max;
53
54         /* For cleaning up after transmission. */
55         struct tasklet_struct tasklet;
56         bool free_in_tasklet;
57
58         /* I like... big packets and I cannot lie! */
59         bool big_packets;
60
61         /* Receive & send queues. */
62         struct sk_buff_head recv;
63         struct sk_buff_head send;
64
65         /* Chain pages by the private ptr. */
66         struct page *pages;
67 };
68
69 static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb)
70 {
71         return (struct virtio_net_hdr *)skb->cb;
72 }
73
74 static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
75 {
76         sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
77 }
78
79 static void give_a_page(struct virtnet_info *vi, struct page *page)
80 {
81         page->private = (unsigned long)vi->pages;
82         vi->pages = page;
83 }
84
85 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
86 {
87         struct page *p = vi->pages;
88
89         if (p)
90                 vi->pages = (struct page *)p->private;
91         else
92                 p = alloc_page(gfp_mask);
93         return p;
94 }
95
96 static void skb_xmit_done(struct virtqueue *svq)
97 {
98         struct virtnet_info *vi = svq->vdev->priv;
99
100         /* Suppress further interrupts. */
101         svq->vq_ops->disable_cb(svq);
102
103         /* We were probably waiting for more output buffers. */
104         netif_wake_queue(vi->dev);
105
106         /* Make sure we re-xmit last_xmit_skb: if there are no more packets
107          * queued, start_xmit won't be called. */
108         tasklet_schedule(&vi->tasklet);
109 }
110
111 static void receive_skb(struct net_device *dev, struct sk_buff *skb,
112                         unsigned len)
113 {
114         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
115         int err;
116
117         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
118                 pr_debug("%s: short packet %i\n", dev->name, len);
119                 dev->stats.rx_length_errors++;
120                 goto drop;
121         }
122         len -= sizeof(struct virtio_net_hdr);
123
124         if (len <= MAX_PACKET_LEN) {
125                 unsigned int i;
126
127                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
128                         give_a_page(dev->priv, skb_shinfo(skb)->frags[i].page);
129                 skb->data_len = 0;
130                 skb_shinfo(skb)->nr_frags = 0;
131         }
132
133         err = pskb_trim(skb, len);
134         if (err) {
135                 pr_debug("%s: pskb_trim failed %i %d\n", dev->name, len, err);
136                 dev->stats.rx_dropped++;
137                 goto drop;
138         }
139         skb->truesize += skb->data_len;
140         dev->stats.rx_bytes += skb->len;
141         dev->stats.rx_packets++;
142
143         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
144                 pr_debug("Needs csum!\n");
145                 if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
146                         goto frame_err;
147         }
148
149         skb->protocol = eth_type_trans(skb, dev);
150         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
151                  ntohs(skb->protocol), skb->len, skb->pkt_type);
152
153         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
154                 pr_debug("GSO!\n");
155                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
156                 case VIRTIO_NET_HDR_GSO_TCPV4:
157                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
158                         break;
159                 case VIRTIO_NET_HDR_GSO_UDP:
160                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
161                         break;
162                 case VIRTIO_NET_HDR_GSO_TCPV6:
163                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
164                         break;
165                 default:
166                         if (net_ratelimit())
167                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
168                                        dev->name, hdr->gso_type);
169                         goto frame_err;
170                 }
171
172                 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
173                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
174
175                 skb_shinfo(skb)->gso_size = hdr->gso_size;
176                 if (skb_shinfo(skb)->gso_size == 0) {
177                         if (net_ratelimit())
178                                 printk(KERN_WARNING "%s: zero gso size.\n",
179                                        dev->name);
180                         goto frame_err;
181                 }
182
183                 /* Header must be checked, and gso_segs computed. */
184                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
185                 skb_shinfo(skb)->gso_segs = 0;
186         }
187
188         netif_receive_skb(skb);
189         return;
190
191 frame_err:
192         dev->stats.rx_frame_errors++;
193 drop:
194         dev_kfree_skb(skb);
195 }
196
197 static void try_fill_recv(struct virtnet_info *vi)
198 {
199         struct sk_buff *skb;
200         struct scatterlist sg[2+MAX_SKB_FRAGS];
201         int num, err, i;
202
203         sg_init_table(sg, 2+MAX_SKB_FRAGS);
204         for (;;) {
205                 skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
206                 if (unlikely(!skb))
207                         break;
208
209                 skb_put(skb, MAX_PACKET_LEN);
210                 vnet_hdr_to_sg(sg, skb);
211
212                 if (vi->big_packets) {
213                         for (i = 0; i < MAX_SKB_FRAGS; i++) {
214                                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
215                                 f->page = get_a_page(vi, GFP_ATOMIC);
216                                 if (!f->page)
217                                         break;
218
219                                 f->page_offset = 0;
220                                 f->size = PAGE_SIZE;
221
222                                 skb->data_len += PAGE_SIZE;
223                                 skb->len += PAGE_SIZE;
224
225                                 skb_shinfo(skb)->nr_frags++;
226                         }
227                 }
228
229                 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
230                 skb_queue_head(&vi->recv, skb);
231
232                 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
233                 if (err) {
234                         skb_unlink(skb, &vi->recv);
235                         kfree_skb(skb);
236                         break;
237                 }
238                 vi->num++;
239         }
240         if (unlikely(vi->num > vi->max))
241                 vi->max = vi->num;
242         vi->rvq->vq_ops->kick(vi->rvq);
243 }
244
245 static void skb_recv_done(struct virtqueue *rvq)
246 {
247         struct virtnet_info *vi = rvq->vdev->priv;
248         /* Schedule NAPI, Suppress further interrupts if successful. */
249         if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
250                 rvq->vq_ops->disable_cb(rvq);
251                 __netif_rx_schedule(vi->dev, &vi->napi);
252         }
253 }
254
255 static int virtnet_poll(struct napi_struct *napi, int budget)
256 {
257         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
258         struct sk_buff *skb = NULL;
259         unsigned int len, received = 0;
260
261 again:
262         while (received < budget &&
263                (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
264                 __skb_unlink(skb, &vi->recv);
265                 receive_skb(vi->dev, skb, len);
266                 vi->num--;
267                 received++;
268         }
269
270         /* FIXME: If we oom and completely run out of inbufs, we need
271          * to start a timer trying to fill more. */
272         if (vi->num < vi->max / 2)
273                 try_fill_recv(vi);
274
275         /* Out of packets? */
276         if (received < budget) {
277                 netif_rx_complete(vi->dev, napi);
278                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
279                     && napi_schedule_prep(napi)) {
280                         vi->rvq->vq_ops->disable_cb(vi->rvq);
281                         __netif_rx_schedule(vi->dev, napi);
282                         goto again;
283                 }
284         }
285
286         return received;
287 }
288
289 static void free_old_xmit_skbs(struct virtnet_info *vi)
290 {
291         struct sk_buff *skb;
292         unsigned int len;
293
294         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
295                 pr_debug("Sent skb %p\n", skb);
296                 __skb_unlink(skb, &vi->send);
297                 vi->dev->stats.tx_bytes += skb->len;
298                 vi->dev->stats.tx_packets++;
299                 kfree_skb(skb);
300         }
301 }
302
303 /* If the virtio transport doesn't always notify us when all in-flight packets
304  * are consumed, we fall back to using this function on a timer to free them. */
305 static void xmit_free(unsigned long data)
306 {
307         struct virtnet_info *vi = (void *)data;
308
309         netif_tx_lock(vi->dev);
310
311         free_old_xmit_skbs(vi);
312
313         if (!skb_queue_empty(&vi->send))
314                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
315
316         netif_tx_unlock(vi->dev);
317 }
318
319 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
320 {
321         int num, err;
322         struct scatterlist sg[2+MAX_SKB_FRAGS];
323         struct virtio_net_hdr *hdr;
324         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
325
326         sg_init_table(sg, 2+MAX_SKB_FRAGS);
327
328         pr_debug("%s: xmit %p " MAC_FMT "\n", vi->dev->name, skb,
329                  dest[0], dest[1], dest[2],
330                  dest[3], dest[4], dest[5]);
331
332         /* Encode metadata header at front. */
333         hdr = skb_vnet_hdr(skb);
334         if (skb->ip_summed == CHECKSUM_PARTIAL) {
335                 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
336                 hdr->csum_start = skb->csum_start - skb_headroom(skb);
337                 hdr->csum_offset = skb->csum_offset;
338         } else {
339                 hdr->flags = 0;
340                 hdr->csum_offset = hdr->csum_start = 0;
341         }
342
343         if (skb_is_gso(skb)) {
344                 hdr->hdr_len = skb_transport_header(skb) - skb->data;
345                 hdr->gso_size = skb_shinfo(skb)->gso_size;
346                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
347                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
348                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
349                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
350                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
351                         hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
352                 else
353                         BUG();
354                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
355                         hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
356         } else {
357                 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
358                 hdr->gso_size = hdr->hdr_len = 0;
359         }
360
361         vnet_hdr_to_sg(sg, skb);
362         num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
363
364         err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
365         if (!err && !vi->free_in_tasklet)
366                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
367
368         return err;
369 }
370
371 static void xmit_tasklet(unsigned long data)
372 {
373         struct virtnet_info *vi = (void *)data;
374
375         netif_tx_lock_bh(vi->dev);
376         if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
377                 vi->svq->vq_ops->kick(vi->svq);
378                 vi->last_xmit_skb = NULL;
379         }
380         if (vi->free_in_tasklet)
381                 free_old_xmit_skbs(vi);
382         netif_tx_unlock_bh(vi->dev);
383 }
384
385 static int start_xmit(struct sk_buff *skb, struct net_device *dev)
386 {
387         struct virtnet_info *vi = netdev_priv(dev);
388
389 again:
390         /* Free up any pending old buffers before queueing new ones. */
391         free_old_xmit_skbs(vi);
392
393         /* If we has a buffer left over from last time, send it now. */
394         if (unlikely(vi->last_xmit_skb) &&
395             xmit_skb(vi, vi->last_xmit_skb) != 0)
396                 goto stop_queue;
397
398         vi->last_xmit_skb = NULL;
399
400         /* Put new one in send queue and do transmit */
401         if (likely(skb)) {
402                 __skb_queue_head(&vi->send, skb);
403                 if (xmit_skb(vi, skb) != 0) {
404                         vi->last_xmit_skb = skb;
405                         skb = NULL;
406                         goto stop_queue;
407                 }
408         }
409 done:
410         vi->svq->vq_ops->kick(vi->svq);
411         return NETDEV_TX_OK;
412
413 stop_queue:
414         pr_debug("%s: virtio not prepared to send\n", dev->name);
415         netif_stop_queue(dev);
416
417         /* Activate callback for using skbs: if this returns false it
418          * means some were used in the meantime. */
419         if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
420                 vi->svq->vq_ops->disable_cb(vi->svq);
421                 netif_start_queue(dev);
422                 goto again;
423         }
424         if (skb) {
425                 /* Drop this skb: we only queue one. */
426                 vi->dev->stats.tx_dropped++;
427                 kfree_skb(skb);
428         }
429         goto done;
430 }
431
432 #ifdef CONFIG_NET_POLL_CONTROLLER
433 static void virtnet_netpoll(struct net_device *dev)
434 {
435         struct virtnet_info *vi = netdev_priv(dev);
436
437         napi_schedule(&vi->napi);
438 }
439 #endif
440
441 static int virtnet_open(struct net_device *dev)
442 {
443         struct virtnet_info *vi = netdev_priv(dev);
444
445         napi_enable(&vi->napi);
446
447         /* If all buffers were filled by other side before we napi_enabled, we
448          * won't get another interrupt, so process any outstanding packets
449          * now.  virtnet_poll wants re-enable the queue, so we disable here.
450          * We synchronize against interrupts via NAPI_STATE_SCHED */
451         if (netif_rx_schedule_prep(dev, &vi->napi)) {
452                 vi->rvq->vq_ops->disable_cb(vi->rvq);
453                 __netif_rx_schedule(dev, &vi->napi);
454         }
455         return 0;
456 }
457
458 static int virtnet_close(struct net_device *dev)
459 {
460         struct virtnet_info *vi = netdev_priv(dev);
461
462         napi_disable(&vi->napi);
463
464         return 0;
465 }
466
467 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
468 {
469         struct virtnet_info *vi = netdev_priv(dev);
470         struct virtio_device *vdev = vi->vdev;
471
472         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
473                 return -ENOSYS;
474
475         return ethtool_op_set_tx_hw_csum(dev, data);
476 }
477
478 static struct ethtool_ops virtnet_ethtool_ops = {
479         .set_tx_csum = virtnet_set_tx_csum,
480         .set_sg = ethtool_op_set_sg,
481 };
482
483 static int virtnet_probe(struct virtio_device *vdev)
484 {
485         int err;
486         struct net_device *dev;
487         struct virtnet_info *vi;
488
489         /* Allocate ourselves a network device with room for our info */
490         dev = alloc_etherdev(sizeof(struct virtnet_info));
491         if (!dev)
492                 return -ENOMEM;
493
494         /* Set up network device as normal. */
495         dev->open = virtnet_open;
496         dev->stop = virtnet_close;
497         dev->hard_start_xmit = start_xmit;
498         dev->features = NETIF_F_HIGHDMA;
499 #ifdef CONFIG_NET_POLL_CONTROLLER
500         dev->poll_controller = virtnet_netpoll;
501 #endif
502         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
503         SET_NETDEV_DEV(dev, &vdev->dev);
504
505         /* Do we support "hardware" checksums? */
506         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
507                 /* This opens up the world of extra features. */
508                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
509                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
510                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
511                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
512                 }
513                 /* Individual feature bits: what can host handle? */
514                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
515                         dev->features |= NETIF_F_TSO;
516                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
517                         dev->features |= NETIF_F_TSO6;
518                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
519                         dev->features |= NETIF_F_TSO_ECN;
520                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
521                         dev->features |= NETIF_F_UFO;
522         }
523
524         /* Configuration may specify what MAC to use.  Otherwise random. */
525         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
526                 vdev->config->get(vdev,
527                                   offsetof(struct virtio_net_config, mac),
528                                   dev->dev_addr, dev->addr_len);
529         } else
530                 random_ether_addr(dev->dev_addr);
531
532         /* Set up our device-specific information */
533         vi = netdev_priv(dev);
534         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
535         vi->dev = dev;
536         vi->vdev = vdev;
537         vdev->priv = vi;
538         vi->pages = NULL;
539
540         /* If they give us a callback when all buffers are done, we don't need
541          * the timer. */
542         vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
543
544         /* If we can receive ANY GSO packets, we must allocate large ones. */
545         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
546             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
547             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
548                 vi->big_packets = true;
549
550         /* We expect two virtqueues, receive then send. */
551         vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
552         if (IS_ERR(vi->rvq)) {
553                 err = PTR_ERR(vi->rvq);
554                 goto free;
555         }
556
557         vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
558         if (IS_ERR(vi->svq)) {
559                 err = PTR_ERR(vi->svq);
560                 goto free_recv;
561         }
562
563         /* Initialize our empty receive and send queues. */
564         skb_queue_head_init(&vi->recv);
565         skb_queue_head_init(&vi->send);
566
567         tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
568
569         if (!vi->free_in_tasklet)
570                 setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
571
572         err = register_netdev(dev);
573         if (err) {
574                 pr_debug("virtio_net: registering device failed\n");
575                 goto free_send;
576         }
577
578         /* Last of all, set up some receive buffers. */
579         try_fill_recv(vi);
580
581         /* If we didn't even get one input buffer, we're useless. */
582         if (vi->num == 0) {
583                 err = -ENOMEM;
584                 goto unregister;
585         }
586
587         pr_debug("virtnet: registered device %s\n", dev->name);
588         return 0;
589
590 unregister:
591         unregister_netdev(dev);
592 free_send:
593         vdev->config->del_vq(vi->svq);
594 free_recv:
595         vdev->config->del_vq(vi->rvq);
596 free:
597         free_netdev(dev);
598         return err;
599 }
600
601 static void virtnet_remove(struct virtio_device *vdev)
602 {
603         struct virtnet_info *vi = vdev->priv;
604         struct sk_buff *skb;
605
606         /* Stop all the virtqueues. */
607         vdev->config->reset(vdev);
608
609         if (!vi->free_in_tasklet)
610                 del_timer_sync(&vi->xmit_free_timer);
611
612         /* Free our skbs in send and recv queues, if any. */
613         while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
614                 kfree_skb(skb);
615                 vi->num--;
616         }
617         __skb_queue_purge(&vi->send);
618
619         BUG_ON(vi->num != 0);
620
621         vdev->config->del_vq(vi->svq);
622         vdev->config->del_vq(vi->rvq);
623         unregister_netdev(vi->dev);
624
625         while (vi->pages)
626                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
627
628         free_netdev(vi->dev);
629 }
630
631 static struct virtio_device_id id_table[] = {
632         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
633         { 0 },
634 };
635
636 static unsigned int features[] = {
637         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
638         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
639         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
640         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
641         VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
642         VIRTIO_F_NOTIFY_ON_EMPTY,
643 };
644
645 static struct virtio_driver virtio_net = {
646         .feature_table = features,
647         .feature_table_size = ARRAY_SIZE(features),
648         .driver.name =  KBUILD_MODNAME,
649         .driver.owner = THIS_MODULE,
650         .id_table =     id_table,
651         .probe =        virtnet_probe,
652         .remove =       __devexit_p(virtnet_remove),
653 };
654
655 static int __init init(void)
656 {
657         return register_virtio_driver(&virtio_net);
658 }
659
660 static void __exit fini(void)
661 {
662         unregister_virtio_driver(&virtio_net);
663 }
664 module_init(init);
665 module_exit(fini);
666
667 MODULE_DEVICE_TABLE(virtio, id_table);
668 MODULE_DESCRIPTION("Virtio network driver");
669 MODULE_LICENSE("GPL");