virtio net: Allow receiving SG packets
[safe/jmp/linux-2.6] / 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
66 static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb)
67 {
68         return (struct virtio_net_hdr *)skb->cb;
69 }
70
71 static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
72 {
73         sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
74 }
75
76 static void skb_xmit_done(struct virtqueue *svq)
77 {
78         struct virtnet_info *vi = svq->vdev->priv;
79
80         /* Suppress further interrupts. */
81         svq->vq_ops->disable_cb(svq);
82
83         /* We were probably waiting for more output buffers. */
84         netif_wake_queue(vi->dev);
85
86         /* Make sure we re-xmit last_xmit_skb: if there are no more packets
87          * queued, start_xmit won't be called. */
88         tasklet_schedule(&vi->tasklet);
89 }
90
91 static void receive_skb(struct net_device *dev, struct sk_buff *skb,
92                         unsigned len)
93 {
94         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
95         int err;
96
97         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
98                 pr_debug("%s: short packet %i\n", dev->name, len);
99                 dev->stats.rx_length_errors++;
100                 goto drop;
101         }
102         len -= sizeof(struct virtio_net_hdr);
103
104         err = pskb_trim(skb, len);
105         if (err) {
106                 pr_debug("%s: pskb_trim failed %i %d\n", dev->name, len, err);
107                 dev->stats.rx_dropped++;
108                 goto drop;
109         }
110         skb->truesize += skb->data_len;
111         dev->stats.rx_bytes += skb->len;
112         dev->stats.rx_packets++;
113
114         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
115                 pr_debug("Needs csum!\n");
116                 if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
117                         goto frame_err;
118         }
119
120         skb->protocol = eth_type_trans(skb, dev);
121         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
122                  ntohs(skb->protocol), skb->len, skb->pkt_type);
123
124         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
125                 pr_debug("GSO!\n");
126                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
127                 case VIRTIO_NET_HDR_GSO_TCPV4:
128                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
129                         break;
130                 case VIRTIO_NET_HDR_GSO_UDP:
131                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
132                         break;
133                 case VIRTIO_NET_HDR_GSO_TCPV6:
134                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
135                         break;
136                 default:
137                         if (net_ratelimit())
138                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
139                                        dev->name, hdr->gso_type);
140                         goto frame_err;
141                 }
142
143                 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
144                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
145
146                 skb_shinfo(skb)->gso_size = hdr->gso_size;
147                 if (skb_shinfo(skb)->gso_size == 0) {
148                         if (net_ratelimit())
149                                 printk(KERN_WARNING "%s: zero gso size.\n",
150                                        dev->name);
151                         goto frame_err;
152                 }
153
154                 /* Header must be checked, and gso_segs computed. */
155                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
156                 skb_shinfo(skb)->gso_segs = 0;
157         }
158
159         netif_receive_skb(skb);
160         return;
161
162 frame_err:
163         dev->stats.rx_frame_errors++;
164 drop:
165         dev_kfree_skb(skb);
166 }
167
168 static void try_fill_recv(struct virtnet_info *vi)
169 {
170         struct sk_buff *skb;
171         struct scatterlist sg[2+MAX_SKB_FRAGS];
172         int num, err, i;
173
174         sg_init_table(sg, 2+MAX_SKB_FRAGS);
175         for (;;) {
176                 skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
177                 if (unlikely(!skb))
178                         break;
179
180                 skb_put(skb, MAX_PACKET_LEN);
181                 vnet_hdr_to_sg(sg, skb);
182
183                 if (vi->big_packets) {
184                         for (i = 0; i < MAX_SKB_FRAGS; i++) {
185                                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
186                                 f->page = alloc_page(GFP_ATOMIC);
187                                 if (!f->page)
188                                         break;
189
190                                 f->page_offset = 0;
191                                 f->size = PAGE_SIZE;
192
193                                 skb->data_len += PAGE_SIZE;
194                                 skb->len += PAGE_SIZE;
195
196                                 skb_shinfo(skb)->nr_frags++;
197                         }
198                 }
199
200                 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
201                 skb_queue_head(&vi->recv, skb);
202
203                 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
204                 if (err) {
205                         skb_unlink(skb, &vi->recv);
206                         kfree_skb(skb);
207                         break;
208                 }
209                 vi->num++;
210         }
211         if (unlikely(vi->num > vi->max))
212                 vi->max = vi->num;
213         vi->rvq->vq_ops->kick(vi->rvq);
214 }
215
216 static void skb_recv_done(struct virtqueue *rvq)
217 {
218         struct virtnet_info *vi = rvq->vdev->priv;
219         /* Schedule NAPI, Suppress further interrupts if successful. */
220         if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
221                 rvq->vq_ops->disable_cb(rvq);
222                 __netif_rx_schedule(vi->dev, &vi->napi);
223         }
224 }
225
226 static int virtnet_poll(struct napi_struct *napi, int budget)
227 {
228         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
229         struct sk_buff *skb = NULL;
230         unsigned int len, received = 0;
231
232 again:
233         while (received < budget &&
234                (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
235                 __skb_unlink(skb, &vi->recv);
236                 receive_skb(vi->dev, skb, len);
237                 vi->num--;
238                 received++;
239         }
240
241         /* FIXME: If we oom and completely run out of inbufs, we need
242          * to start a timer trying to fill more. */
243         if (vi->num < vi->max / 2)
244                 try_fill_recv(vi);
245
246         /* Out of packets? */
247         if (received < budget) {
248                 netif_rx_complete(vi->dev, napi);
249                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
250                     && napi_schedule_prep(napi)) {
251                         vi->rvq->vq_ops->disable_cb(vi->rvq);
252                         __netif_rx_schedule(vi->dev, napi);
253                         goto again;
254                 }
255         }
256
257         return received;
258 }
259
260 static void free_old_xmit_skbs(struct virtnet_info *vi)
261 {
262         struct sk_buff *skb;
263         unsigned int len;
264
265         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
266                 pr_debug("Sent skb %p\n", skb);
267                 __skb_unlink(skb, &vi->send);
268                 vi->dev->stats.tx_bytes += skb->len;
269                 vi->dev->stats.tx_packets++;
270                 kfree_skb(skb);
271         }
272 }
273
274 /* If the virtio transport doesn't always notify us when all in-flight packets
275  * are consumed, we fall back to using this function on a timer to free them. */
276 static void xmit_free(unsigned long data)
277 {
278         struct virtnet_info *vi = (void *)data;
279
280         netif_tx_lock(vi->dev);
281
282         free_old_xmit_skbs(vi);
283
284         if (!skb_queue_empty(&vi->send))
285                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
286
287         netif_tx_unlock(vi->dev);
288 }
289
290 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
291 {
292         int num, err;
293         struct scatterlist sg[2+MAX_SKB_FRAGS];
294         struct virtio_net_hdr *hdr;
295         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
296
297         sg_init_table(sg, 2+MAX_SKB_FRAGS);
298
299         pr_debug("%s: xmit %p " MAC_FMT "\n", vi->dev->name, skb,
300                  dest[0], dest[1], dest[2],
301                  dest[3], dest[4], dest[5]);
302
303         /* Encode metadata header at front. */
304         hdr = skb_vnet_hdr(skb);
305         if (skb->ip_summed == CHECKSUM_PARTIAL) {
306                 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
307                 hdr->csum_start = skb->csum_start - skb_headroom(skb);
308                 hdr->csum_offset = skb->csum_offset;
309         } else {
310                 hdr->flags = 0;
311                 hdr->csum_offset = hdr->csum_start = 0;
312         }
313
314         if (skb_is_gso(skb)) {
315                 hdr->hdr_len = skb_transport_header(skb) - skb->data;
316                 hdr->gso_size = skb_shinfo(skb)->gso_size;
317                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
318                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
319                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
320                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
321                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
322                         hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
323                 else
324                         BUG();
325                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
326                         hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
327         } else {
328                 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
329                 hdr->gso_size = hdr->hdr_len = 0;
330         }
331
332         vnet_hdr_to_sg(sg, skb);
333         num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
334
335         err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
336         if (!err && !vi->free_in_tasklet)
337                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
338
339         return err;
340 }
341
342 static void xmit_tasklet(unsigned long data)
343 {
344         struct virtnet_info *vi = (void *)data;
345
346         netif_tx_lock_bh(vi->dev);
347         if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
348                 vi->svq->vq_ops->kick(vi->svq);
349                 vi->last_xmit_skb = NULL;
350         }
351         if (vi->free_in_tasklet)
352                 free_old_xmit_skbs(vi);
353         netif_tx_unlock_bh(vi->dev);
354 }
355
356 static int start_xmit(struct sk_buff *skb, struct net_device *dev)
357 {
358         struct virtnet_info *vi = netdev_priv(dev);
359
360 again:
361         /* Free up any pending old buffers before queueing new ones. */
362         free_old_xmit_skbs(vi);
363
364         /* If we has a buffer left over from last time, send it now. */
365         if (unlikely(vi->last_xmit_skb) &&
366             xmit_skb(vi, vi->last_xmit_skb) != 0)
367                 goto stop_queue;
368
369         vi->last_xmit_skb = NULL;
370
371         /* Put new one in send queue and do transmit */
372         if (likely(skb)) {
373                 __skb_queue_head(&vi->send, skb);
374                 if (xmit_skb(vi, skb) != 0) {
375                         vi->last_xmit_skb = skb;
376                         skb = NULL;
377                         goto stop_queue;
378                 }
379         }
380 done:
381         vi->svq->vq_ops->kick(vi->svq);
382         return NETDEV_TX_OK;
383
384 stop_queue:
385         pr_debug("%s: virtio not prepared to send\n", dev->name);
386         netif_stop_queue(dev);
387
388         /* Activate callback for using skbs: if this returns false it
389          * means some were used in the meantime. */
390         if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
391                 vi->svq->vq_ops->disable_cb(vi->svq);
392                 netif_start_queue(dev);
393                 goto again;
394         }
395         if (skb) {
396                 /* Drop this skb: we only queue one. */
397                 vi->dev->stats.tx_dropped++;
398                 kfree_skb(skb);
399         }
400         goto done;
401 }
402
403 #ifdef CONFIG_NET_POLL_CONTROLLER
404 static void virtnet_netpoll(struct net_device *dev)
405 {
406         struct virtnet_info *vi = netdev_priv(dev);
407
408         napi_schedule(&vi->napi);
409 }
410 #endif
411
412 static int virtnet_open(struct net_device *dev)
413 {
414         struct virtnet_info *vi = netdev_priv(dev);
415
416         napi_enable(&vi->napi);
417
418         /* If all buffers were filled by other side before we napi_enabled, we
419          * won't get another interrupt, so process any outstanding packets
420          * now.  virtnet_poll wants re-enable the queue, so we disable here.
421          * We synchronize against interrupts via NAPI_STATE_SCHED */
422         if (netif_rx_schedule_prep(dev, &vi->napi)) {
423                 vi->rvq->vq_ops->disable_cb(vi->rvq);
424                 __netif_rx_schedule(dev, &vi->napi);
425         }
426         return 0;
427 }
428
429 static int virtnet_close(struct net_device *dev)
430 {
431         struct virtnet_info *vi = netdev_priv(dev);
432
433         napi_disable(&vi->napi);
434
435         return 0;
436 }
437
438 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
439 {
440         struct virtnet_info *vi = netdev_priv(dev);
441         struct virtio_device *vdev = vi->vdev;
442
443         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
444                 return -ENOSYS;
445
446         return ethtool_op_set_tx_hw_csum(dev, data);
447 }
448
449 static struct ethtool_ops virtnet_ethtool_ops = {
450         .set_tx_csum = virtnet_set_tx_csum,
451         .set_sg = ethtool_op_set_sg,
452 };
453
454 static int virtnet_probe(struct virtio_device *vdev)
455 {
456         int err;
457         struct net_device *dev;
458         struct virtnet_info *vi;
459
460         /* Allocate ourselves a network device with room for our info */
461         dev = alloc_etherdev(sizeof(struct virtnet_info));
462         if (!dev)
463                 return -ENOMEM;
464
465         /* Set up network device as normal. */
466         dev->open = virtnet_open;
467         dev->stop = virtnet_close;
468         dev->hard_start_xmit = start_xmit;
469         dev->features = NETIF_F_HIGHDMA;
470 #ifdef CONFIG_NET_POLL_CONTROLLER
471         dev->poll_controller = virtnet_netpoll;
472 #endif
473         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
474         SET_NETDEV_DEV(dev, &vdev->dev);
475
476         /* Do we support "hardware" checksums? */
477         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
478                 /* This opens up the world of extra features. */
479                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
480                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
481                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
482                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
483                 }
484                 /* Individual feature bits: what can host handle? */
485                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
486                         dev->features |= NETIF_F_TSO;
487                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
488                         dev->features |= NETIF_F_TSO6;
489                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
490                         dev->features |= NETIF_F_TSO_ECN;
491                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
492                         dev->features |= NETIF_F_UFO;
493         }
494
495         /* Configuration may specify what MAC to use.  Otherwise random. */
496         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
497                 vdev->config->get(vdev,
498                                   offsetof(struct virtio_net_config, mac),
499                                   dev->dev_addr, dev->addr_len);
500         } else
501                 random_ether_addr(dev->dev_addr);
502
503         /* Set up our device-specific information */
504         vi = netdev_priv(dev);
505         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
506         vi->dev = dev;
507         vi->vdev = vdev;
508         vdev->priv = vi;
509
510         /* If they give us a callback when all buffers are done, we don't need
511          * the timer. */
512         vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
513
514         /* If we can receive ANY GSO packets, we must allocate large ones. */
515         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
516             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
517             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
518                 vi->big_packets = true;
519
520         /* We expect two virtqueues, receive then send. */
521         vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
522         if (IS_ERR(vi->rvq)) {
523                 err = PTR_ERR(vi->rvq);
524                 goto free;
525         }
526
527         vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
528         if (IS_ERR(vi->svq)) {
529                 err = PTR_ERR(vi->svq);
530                 goto free_recv;
531         }
532
533         /* Initialize our empty receive and send queues. */
534         skb_queue_head_init(&vi->recv);
535         skb_queue_head_init(&vi->send);
536
537         tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
538
539         if (!vi->free_in_tasklet)
540                 setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
541
542         err = register_netdev(dev);
543         if (err) {
544                 pr_debug("virtio_net: registering device failed\n");
545                 goto free_send;
546         }
547
548         /* Last of all, set up some receive buffers. */
549         try_fill_recv(vi);
550
551         /* If we didn't even get one input buffer, we're useless. */
552         if (vi->num == 0) {
553                 err = -ENOMEM;
554                 goto unregister;
555         }
556
557         pr_debug("virtnet: registered device %s\n", dev->name);
558         return 0;
559
560 unregister:
561         unregister_netdev(dev);
562 free_send:
563         vdev->config->del_vq(vi->svq);
564 free_recv:
565         vdev->config->del_vq(vi->rvq);
566 free:
567         free_netdev(dev);
568         return err;
569 }
570
571 static void virtnet_remove(struct virtio_device *vdev)
572 {
573         struct virtnet_info *vi = vdev->priv;
574         struct sk_buff *skb;
575
576         /* Stop all the virtqueues. */
577         vdev->config->reset(vdev);
578
579         if (!vi->free_in_tasklet)
580                 del_timer_sync(&vi->xmit_free_timer);
581
582         /* Free our skbs in send and recv queues, if any. */
583         while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
584                 kfree_skb(skb);
585                 vi->num--;
586         }
587         __skb_queue_purge(&vi->send);
588
589         BUG_ON(vi->num != 0);
590
591         vdev->config->del_vq(vi->svq);
592         vdev->config->del_vq(vi->rvq);
593         unregister_netdev(vi->dev);
594         free_netdev(vi->dev);
595 }
596
597 static struct virtio_device_id id_table[] = {
598         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
599         { 0 },
600 };
601
602 static unsigned int features[] = {
603         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
604         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
605         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
606         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
607         VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
608         VIRTIO_F_NOTIFY_ON_EMPTY,
609 };
610
611 static struct virtio_driver virtio_net = {
612         .feature_table = features,
613         .feature_table_size = ARRAY_SIZE(features),
614         .driver.name =  KBUILD_MODNAME,
615         .driver.owner = THIS_MODULE,
616         .id_table =     id_table,
617         .probe =        virtnet_probe,
618         .remove =       __devexit_p(virtnet_remove),
619 };
620
621 static int __init init(void)
622 {
623         return register_virtio_driver(&virtio_net);
624 }
625
626 static void __exit fini(void)
627 {
628         unregister_virtio_driver(&virtio_net);
629 }
630 module_init(init);
631 module_exit(fini);
632
633 MODULE_DEVICE_TABLE(virtio, id_table);
634 MODULE_DESCRIPTION("Virtio network driver");
635 MODULE_LICENSE("GPL");