Root/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#include <linux/if_vlan.h>
28
29static int napi_weight = 128;
30module_param(napi_weight, int, 0444);
31
32static int csum = 1, gso = 1;
33module_param(csum, bool, 0444);
34module_param(gso, bool, 0444);
35
36/* FIXME: MTU in config. */
37#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
38#define GOOD_COPY_LEN 128
39
40#define VIRTNET_SEND_COMMAND_SG_MAX 2
41
42struct virtnet_info
43{
44    struct virtio_device *vdev;
45    struct virtqueue *rvq, *svq, *cvq;
46    struct net_device *dev;
47    struct napi_struct napi;
48    unsigned int status;
49
50    /* The skb we couldn't send because buffers were full. */
51    struct sk_buff *last_xmit_skb;
52
53    /* If we need to free in a timer, this is it. */
54    struct timer_list xmit_free_timer;
55
56    /* Number of input buffers, and max we've ever had. */
57    unsigned int num, max;
58
59    /* For cleaning up after transmission. */
60    struct tasklet_struct tasklet;
61    bool free_in_tasklet;
62
63    /* I like... big packets and I cannot lie! */
64    bool big_packets;
65
66    /* Host will merge rx buffers for big packets (shake it! shake it!) */
67    bool mergeable_rx_bufs;
68
69    /* Receive & send queues. */
70    struct sk_buff_head recv;
71    struct sk_buff_head send;
72
73    /* Work struct for refilling if we run low on memory. */
74    struct delayed_work refill;
75
76    /* Chain pages by the private ptr. */
77    struct page *pages;
78};
79
80static inline void *skb_vnet_hdr(struct sk_buff *skb)
81{
82    return (struct virtio_net_hdr *)skb->cb;
83}
84
85static void give_a_page(struct virtnet_info *vi, struct page *page)
86{
87    page->private = (unsigned long)vi->pages;
88    vi->pages = page;
89}
90
91static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb)
92{
93    unsigned int i;
94
95    for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
96        give_a_page(vi, skb_shinfo(skb)->frags[i].page);
97    skb_shinfo(skb)->nr_frags = 0;
98    skb->data_len = 0;
99}
100
101static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
102{
103    struct page *p = vi->pages;
104
105    if (p)
106        vi->pages = (struct page *)p->private;
107    else
108        p = alloc_page(gfp_mask);
109    return p;
110}
111
112static void skb_xmit_done(struct virtqueue *svq)
113{
114    struct virtnet_info *vi = svq->vdev->priv;
115
116    /* Suppress further interrupts. */
117    svq->vq_ops->disable_cb(svq);
118
119    /* We were probably waiting for more output buffers. */
120    netif_wake_queue(vi->dev);
121
122    /* Make sure we re-xmit last_xmit_skb: if there are no more packets
123     * queued, start_xmit won't be called. */
124    tasklet_schedule(&vi->tasklet);
125}
126
127static void receive_skb(struct net_device *dev, struct sk_buff *skb,
128            unsigned len)
129{
130    struct virtnet_info *vi = netdev_priv(dev);
131    struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
132    int err;
133    int i;
134
135    if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
136        pr_debug("%s: short packet %i\n", dev->name, len);
137        dev->stats.rx_length_errors++;
138        goto drop;
139    }
140
141    if (vi->mergeable_rx_bufs) {
142        struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
143        unsigned int copy;
144        char *p = page_address(skb_shinfo(skb)->frags[0].page);
145
146        if (len > PAGE_SIZE)
147            len = PAGE_SIZE;
148        len -= sizeof(struct virtio_net_hdr_mrg_rxbuf);
149
150        memcpy(hdr, p, sizeof(*mhdr));
151        p += sizeof(*mhdr);
152
153        copy = len;
154        if (copy > skb_tailroom(skb))
155            copy = skb_tailroom(skb);
156
157        memcpy(skb_put(skb, copy), p, copy);
158
159        len -= copy;
160
161        if (!len) {
162            give_a_page(vi, skb_shinfo(skb)->frags[0].page);
163            skb_shinfo(skb)->nr_frags--;
164        } else {
165            skb_shinfo(skb)->frags[0].page_offset +=
166                sizeof(*mhdr) + copy;
167            skb_shinfo(skb)->frags[0].size = len;
168            skb->data_len += len;
169            skb->len += len;
170        }
171
172        while (--mhdr->num_buffers) {
173            struct sk_buff *nskb;
174
175            i = skb_shinfo(skb)->nr_frags;
176            if (i >= MAX_SKB_FRAGS) {
177                pr_debug("%s: packet too long %d\n", dev->name,
178                     len);
179                dev->stats.rx_length_errors++;
180                goto drop;
181            }
182
183            nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
184            if (!nskb) {
185                pr_debug("%s: rx error: %d buffers missing\n",
186                     dev->name, mhdr->num_buffers);
187                dev->stats.rx_length_errors++;
188                goto drop;
189            }
190
191            __skb_unlink(nskb, &vi->recv);
192            vi->num--;
193
194            skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0];
195            skb_shinfo(nskb)->nr_frags = 0;
196            kfree_skb(nskb);
197
198            if (len > PAGE_SIZE)
199                len = PAGE_SIZE;
200
201            skb_shinfo(skb)->frags[i].size = len;
202            skb_shinfo(skb)->nr_frags++;
203            skb->data_len += len;
204            skb->len += len;
205        }
206    } else {
207        len -= sizeof(struct virtio_net_hdr);
208
209        if (len <= MAX_PACKET_LEN)
210            trim_pages(vi, skb);
211
212        err = pskb_trim(skb, len);
213        if (err) {
214            pr_debug("%s: pskb_trim failed %i %d\n", dev->name,
215                 len, err);
216            dev->stats.rx_dropped++;
217            goto drop;
218        }
219    }
220
221    skb->truesize += skb->data_len;
222    dev->stats.rx_bytes += skb->len;
223    dev->stats.rx_packets++;
224
225    if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
226        pr_debug("Needs csum!\n");
227        if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
228            goto frame_err;
229    }
230
231    skb->protocol = eth_type_trans(skb, dev);
232    pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
233         ntohs(skb->protocol), skb->len, skb->pkt_type);
234
235    if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
236        pr_debug("GSO!\n");
237        switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
238        case VIRTIO_NET_HDR_GSO_TCPV4:
239            skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
240            break;
241        case VIRTIO_NET_HDR_GSO_UDP:
242            skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
243            break;
244        case VIRTIO_NET_HDR_GSO_TCPV6:
245            skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
246            break;
247        default:
248            if (net_ratelimit())
249                printk(KERN_WARNING "%s: bad gso type %u.\n",
250                       dev->name, hdr->gso_type);
251            goto frame_err;
252        }
253
254        if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
255            skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
256
257        skb_shinfo(skb)->gso_size = hdr->gso_size;
258        if (skb_shinfo(skb)->gso_size == 0) {
259            if (net_ratelimit())
260                printk(KERN_WARNING "%s: zero gso size.\n",
261                       dev->name);
262            goto frame_err;
263        }
264
265        /* Header must be checked, and gso_segs computed. */
266        skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
267        skb_shinfo(skb)->gso_segs = 0;
268    }
269
270    netif_receive_skb(skb);
271    return;
272
273frame_err:
274    dev->stats.rx_frame_errors++;
275drop:
276    dev_kfree_skb(skb);
277}
278
279static bool try_fill_recv_maxbufs(struct virtnet_info *vi, gfp_t gfp)
280{
281    struct sk_buff *skb;
282    struct scatterlist sg[2+MAX_SKB_FRAGS];
283    int num, err, i;
284    bool oom = false;
285
286    sg_init_table(sg, 2+MAX_SKB_FRAGS);
287    for (;;) {
288        struct virtio_net_hdr *hdr;
289
290        skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN + NET_IP_ALIGN);
291        if (unlikely(!skb)) {
292            oom = true;
293            break;
294        }
295
296        skb_reserve(skb, NET_IP_ALIGN);
297        skb_put(skb, MAX_PACKET_LEN);
298
299        hdr = skb_vnet_hdr(skb);
300        sg_set_buf(sg, hdr, sizeof(*hdr));
301
302        if (vi->big_packets) {
303            for (i = 0; i < MAX_SKB_FRAGS; i++) {
304                skb_frag_t *f = &skb_shinfo(skb)->frags[i];
305                f->page = get_a_page(vi, gfp);
306                if (!f->page)
307                    break;
308
309                f->page_offset = 0;
310                f->size = PAGE_SIZE;
311
312                skb->data_len += PAGE_SIZE;
313                skb->len += PAGE_SIZE;
314
315                skb_shinfo(skb)->nr_frags++;
316            }
317        }
318
319        num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
320        skb_queue_head(&vi->recv, skb);
321
322        err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
323        if (err) {
324            skb_unlink(skb, &vi->recv);
325            trim_pages(vi, skb);
326            kfree_skb(skb);
327            break;
328        }
329        vi->num++;
330    }
331    if (unlikely(vi->num > vi->max))
332        vi->max = vi->num;
333    vi->rvq->vq_ops->kick(vi->rvq);
334    return !oom;
335}
336
337/* Returns false if we couldn't fill entirely (OOM). */
338static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
339{
340    struct sk_buff *skb;
341    struct scatterlist sg[1];
342    int err;
343    bool oom = false;
344
345    if (!vi->mergeable_rx_bufs)
346        return try_fill_recv_maxbufs(vi, gfp);
347
348    for (;;) {
349        skb_frag_t *f;
350
351        skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN);
352        if (unlikely(!skb)) {
353            oom = true;
354            break;
355        }
356
357        skb_reserve(skb, NET_IP_ALIGN);
358
359        f = &skb_shinfo(skb)->frags[0];
360        f->page = get_a_page(vi, gfp);
361        if (!f->page) {
362            oom = true;
363            kfree_skb(skb);
364            break;
365        }
366
367        f->page_offset = 0;
368        f->size = PAGE_SIZE;
369
370        skb_shinfo(skb)->nr_frags++;
371
372        sg_init_one(sg, page_address(f->page), PAGE_SIZE);
373        skb_queue_head(&vi->recv, skb);
374
375        err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb);
376        if (err) {
377            skb_unlink(skb, &vi->recv);
378            kfree_skb(skb);
379            break;
380        }
381        vi->num++;
382    }
383    if (unlikely(vi->num > vi->max))
384        vi->max = vi->num;
385    vi->rvq->vq_ops->kick(vi->rvq);
386    return !oom;
387}
388
389static void skb_recv_done(struct virtqueue *rvq)
390{
391    struct virtnet_info *vi = rvq->vdev->priv;
392    /* Schedule NAPI, Suppress further interrupts if successful. */
393    if (napi_schedule_prep(&vi->napi)) {
394        rvq->vq_ops->disable_cb(rvq);
395        __napi_schedule(&vi->napi);
396    }
397}
398
399static void refill_work(struct work_struct *work)
400{
401    struct virtnet_info *vi;
402    bool still_empty;
403
404    vi = container_of(work, struct virtnet_info, refill.work);
405    napi_disable(&vi->napi);
406    try_fill_recv(vi, GFP_KERNEL);
407    still_empty = (vi->num == 0);
408    napi_enable(&vi->napi);
409
410    /* In theory, this can happen: if we don't get any buffers in
411     * we will *never* try to fill again. */
412    if (still_empty)
413        schedule_delayed_work(&vi->refill, HZ/2);
414}
415
416static int virtnet_poll(struct napi_struct *napi, int budget)
417{
418    struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
419    struct sk_buff *skb = NULL;
420    unsigned int len, received = 0;
421
422again:
423    while (received < budget &&
424           (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
425        __skb_unlink(skb, &vi->recv);
426        receive_skb(vi->dev, skb, len);
427        vi->num--;
428        received++;
429    }
430
431    if (vi->num < vi->max / 2) {
432        if (!try_fill_recv(vi, GFP_ATOMIC))
433            schedule_delayed_work(&vi->refill, 0);
434    }
435
436    /* Out of packets? */
437    if (received < budget) {
438        napi_complete(napi);
439        if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
440            && napi_schedule_prep(napi)) {
441            vi->rvq->vq_ops->disable_cb(vi->rvq);
442            __napi_schedule(napi);
443            goto again;
444        }
445    }
446
447    return received;
448}
449
450static void free_old_xmit_skbs(struct virtnet_info *vi)
451{
452    struct sk_buff *skb;
453    unsigned int len;
454
455    while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
456        pr_debug("Sent skb %p\n", skb);
457        __skb_unlink(skb, &vi->send);
458        vi->dev->stats.tx_bytes += skb->len;
459        vi->dev->stats.tx_packets++;
460        kfree_skb(skb);
461    }
462}
463
464/* If the virtio transport doesn't always notify us when all in-flight packets
465 * are consumed, we fall back to using this function on a timer to free them. */
466static void xmit_free(unsigned long data)
467{
468    struct virtnet_info *vi = (void *)data;
469
470    netif_tx_lock(vi->dev);
471
472    free_old_xmit_skbs(vi);
473
474    if (!skb_queue_empty(&vi->send))
475        mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
476
477    netif_tx_unlock(vi->dev);
478}
479
480static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
481{
482    int num, err;
483    struct scatterlist sg[2+MAX_SKB_FRAGS];
484    struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
485    struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
486    const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
487
488    sg_init_table(sg, 2+MAX_SKB_FRAGS);
489
490    pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
491
492    if (skb->ip_summed == CHECKSUM_PARTIAL) {
493        hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
494        hdr->csum_start = skb->csum_start - skb_headroom(skb);
495        hdr->csum_offset = skb->csum_offset;
496    } else {
497        hdr->flags = 0;
498        hdr->csum_offset = hdr->csum_start = 0;
499    }
500
501    if (skb_is_gso(skb)) {
502        hdr->hdr_len = skb_headlen(skb);
503        hdr->gso_size = skb_shinfo(skb)->gso_size;
504        if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
505            hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
506        else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
507            hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
508        else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
509            hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
510        else
511            BUG();
512        if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
513            hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
514    } else {
515        hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
516        hdr->gso_size = hdr->hdr_len = 0;
517    }
518
519    mhdr->num_buffers = 0;
520
521    /* Encode metadata header at front. */
522    if (vi->mergeable_rx_bufs)
523        sg_set_buf(sg, mhdr, sizeof(*mhdr));
524    else
525        sg_set_buf(sg, hdr, sizeof(*hdr));
526
527    num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
528
529    err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
530    if (!err && !vi->free_in_tasklet)
531        mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
532
533    return err;
534}
535
536static void xmit_tasklet(unsigned long data)
537{
538    struct virtnet_info *vi = (void *)data;
539
540    netif_tx_lock_bh(vi->dev);
541    if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
542        vi->svq->vq_ops->kick(vi->svq);
543        vi->last_xmit_skb = NULL;
544    }
545    if (vi->free_in_tasklet)
546        free_old_xmit_skbs(vi);
547    netif_tx_unlock_bh(vi->dev);
548}
549
550static int start_xmit(struct sk_buff *skb, struct net_device *dev)
551{
552    struct virtnet_info *vi = netdev_priv(dev);
553
554again:
555    /* Free up any pending old buffers before queueing new ones. */
556    free_old_xmit_skbs(vi);
557
558    /* If we has a buffer left over from last time, send it now. */
559    if (unlikely(vi->last_xmit_skb) &&
560        xmit_skb(vi, vi->last_xmit_skb) != 0)
561        goto stop_queue;
562
563    vi->last_xmit_skb = NULL;
564
565    /* Put new one in send queue and do transmit */
566    if (likely(skb)) {
567        __skb_queue_head(&vi->send, skb);
568        if (xmit_skb(vi, skb) != 0) {
569            vi->last_xmit_skb = skb;
570            skb = NULL;
571            goto stop_queue;
572        }
573    }
574done:
575    vi->svq->vq_ops->kick(vi->svq);
576    return NETDEV_TX_OK;
577
578stop_queue:
579    pr_debug("%s: virtio not prepared to send\n", dev->name);
580    netif_stop_queue(dev);
581
582    /* Activate callback for using skbs: if this returns false it
583     * means some were used in the meantime. */
584    if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
585        vi->svq->vq_ops->disable_cb(vi->svq);
586        netif_start_queue(dev);
587        goto again;
588    }
589    if (skb) {
590        /* Drop this skb: we only queue one. */
591        vi->dev->stats.tx_dropped++;
592        kfree_skb(skb);
593    }
594    goto done;
595}
596
597static int virtnet_set_mac_address(struct net_device *dev, void *p)
598{
599    struct virtnet_info *vi = netdev_priv(dev);
600    struct virtio_device *vdev = vi->vdev;
601    int ret;
602
603    ret = eth_mac_addr(dev, p);
604    if (ret)
605        return ret;
606
607    if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
608        vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
609                          dev->dev_addr, dev->addr_len);
610
611    return 0;
612}
613
614#ifdef CONFIG_NET_POLL_CONTROLLER
615static void virtnet_netpoll(struct net_device *dev)
616{
617    struct virtnet_info *vi = netdev_priv(dev);
618
619    napi_schedule(&vi->napi);
620}
621#endif
622
623static int virtnet_open(struct net_device *dev)
624{
625    struct virtnet_info *vi = netdev_priv(dev);
626
627    napi_enable(&vi->napi);
628
629    /* If all buffers were filled by other side before we napi_enabled, we
630     * won't get another interrupt, so process any outstanding packets
631     * now. virtnet_poll wants re-enable the queue, so we disable here.
632     * We synchronize against interrupts via NAPI_STATE_SCHED */
633    if (napi_schedule_prep(&vi->napi)) {
634        vi->rvq->vq_ops->disable_cb(vi->rvq);
635        __napi_schedule(&vi->napi);
636    }
637    return 0;
638}
639
640/*
641 * Send command via the control virtqueue and check status. Commands
642 * supported by the hypervisor, as indicated by feature bits, should
643 * never fail unless improperly formated.
644 */
645static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
646                 struct scatterlist *data, int out, int in)
647{
648    struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
649    struct virtio_net_ctrl_hdr ctrl;
650    virtio_net_ctrl_ack status = ~0;
651    unsigned int tmp;
652    int i;
653
654    /* Caller should know better */
655    BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
656        (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
657
658    out++; /* Add header */
659    in++; /* Add return status */
660
661    ctrl.class = class;
662    ctrl.cmd = cmd;
663
664    sg_init_table(sg, out + in);
665
666    sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
667    for_each_sg(data, s, out + in - 2, i)
668        sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
669    sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
670
671    BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi));
672
673    vi->cvq->vq_ops->kick(vi->cvq);
674
675    /*
676     * Spin for a response, the kick causes an ioport write, trapping
677     * into the hypervisor, so the request should be handled immediately.
678     */
679    while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
680        cpu_relax();
681
682    return status == VIRTIO_NET_OK;
683}
684
685static int virtnet_close(struct net_device *dev)
686{
687    struct virtnet_info *vi = netdev_priv(dev);
688
689    napi_disable(&vi->napi);
690
691    return 0;
692}
693
694static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
695{
696    struct virtnet_info *vi = netdev_priv(dev);
697    struct virtio_device *vdev = vi->vdev;
698
699    if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
700        return -ENOSYS;
701
702    return ethtool_op_set_tx_hw_csum(dev, data);
703}
704
705static void virtnet_set_rx_mode(struct net_device *dev)
706{
707    struct virtnet_info *vi = netdev_priv(dev);
708    struct scatterlist sg[2];
709    u8 promisc, allmulti;
710    struct virtio_net_ctrl_mac *mac_data;
711    struct dev_addr_list *addr;
712    struct netdev_hw_addr *ha;
713    void *buf;
714    int i;
715
716    /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
717    if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
718        return;
719
720    promisc = ((dev->flags & IFF_PROMISC) != 0);
721    allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
722
723    sg_init_one(sg, &promisc, sizeof(promisc));
724
725    if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
726                  VIRTIO_NET_CTRL_RX_PROMISC,
727                  sg, 1, 0))
728        dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
729             promisc ? "en" : "dis");
730
731    sg_init_one(sg, &allmulti, sizeof(allmulti));
732
733    if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
734                  VIRTIO_NET_CTRL_RX_ALLMULTI,
735                  sg, 1, 0))
736        dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
737             allmulti ? "en" : "dis");
738
739    /* MAC filter - use one buffer for both lists */
740    mac_data = buf = kzalloc(((dev->uc.count + dev->mc_count) * ETH_ALEN) +
741                 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
742    if (!buf) {
743        dev_warn(&dev->dev, "No memory for MAC address buffer\n");
744        return;
745    }
746
747    sg_init_table(sg, 2);
748
749    /* Store the unicast list and count in the front of the buffer */
750    mac_data->entries = dev->uc.count;
751    i = 0;
752    list_for_each_entry(ha, &dev->uc.list, list)
753        memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
754
755    sg_set_buf(&sg[0], mac_data,
756           sizeof(mac_data->entries) + (dev->uc.count * ETH_ALEN));
757
758    /* multicast list and count fill the end */
759    mac_data = (void *)&mac_data->macs[dev->uc.count][0];
760
761    mac_data->entries = dev->mc_count;
762    addr = dev->mc_list;
763    for (i = 0; i < dev->mc_count; i++, addr = addr->next)
764        memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN);
765
766    sg_set_buf(&sg[1], mac_data,
767           sizeof(mac_data->entries) + (dev->mc_count * ETH_ALEN));
768
769    if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
770                  VIRTIO_NET_CTRL_MAC_TABLE_SET,
771                  sg, 2, 0))
772        dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
773
774    kfree(buf);
775}
776
777static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
778{
779    struct virtnet_info *vi = netdev_priv(dev);
780    struct scatterlist sg;
781
782    sg_init_one(&sg, &vid, sizeof(vid));
783
784    if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
785                  VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
786        dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
787}
788
789static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
790{
791    struct virtnet_info *vi = netdev_priv(dev);
792    struct scatterlist sg;
793
794    sg_init_one(&sg, &vid, sizeof(vid));
795
796    if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
797                  VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
798        dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
799}
800
801static struct ethtool_ops virtnet_ethtool_ops = {
802    .set_tx_csum = virtnet_set_tx_csum,
803    .set_sg = ethtool_op_set_sg,
804    .set_tso = ethtool_op_set_tso,
805    .get_link = ethtool_op_get_link,
806};
807
808#define MIN_MTU 68
809#define MAX_MTU 65535
810
811static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
812{
813    if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
814        return -EINVAL;
815    dev->mtu = new_mtu;
816    return 0;
817}
818
819static const struct net_device_ops virtnet_netdev = {
820    .ndo_open = virtnet_open,
821    .ndo_stop = virtnet_close,
822    .ndo_start_xmit = start_xmit,
823    .ndo_validate_addr = eth_validate_addr,
824    .ndo_set_mac_address = virtnet_set_mac_address,
825    .ndo_set_rx_mode = virtnet_set_rx_mode,
826    .ndo_change_mtu = virtnet_change_mtu,
827    .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
828    .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
829#ifdef CONFIG_NET_POLL_CONTROLLER
830    .ndo_poll_controller = virtnet_netpoll,
831#endif
832};
833
834static void virtnet_update_status(struct virtnet_info *vi)
835{
836    u16 v;
837
838    if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
839        return;
840
841    vi->vdev->config->get(vi->vdev,
842                  offsetof(struct virtio_net_config, status),
843                  &v, sizeof(v));
844
845    /* Ignore unknown (future) status bits */
846    v &= VIRTIO_NET_S_LINK_UP;
847
848    if (vi->status == v)
849        return;
850
851    vi->status = v;
852
853    if (vi->status & VIRTIO_NET_S_LINK_UP) {
854        netif_carrier_on(vi->dev);
855        netif_wake_queue(vi->dev);
856    } else {
857        netif_carrier_off(vi->dev);
858        netif_stop_queue(vi->dev);
859    }
860}
861
862static void virtnet_config_changed(struct virtio_device *vdev)
863{
864    struct virtnet_info *vi = vdev->priv;
865
866    virtnet_update_status(vi);
867}
868
869static int virtnet_probe(struct virtio_device *vdev)
870{
871    int err;
872    struct net_device *dev;
873    struct virtnet_info *vi;
874    struct virtqueue *vqs[3];
875    vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
876    const char *names[] = { "input", "output", "control" };
877    int nvqs;
878
879    /* Allocate ourselves a network device with room for our info */
880    dev = alloc_etherdev(sizeof(struct virtnet_info));
881    if (!dev)
882        return -ENOMEM;
883
884    /* Set up network device as normal. */
885    dev->netdev_ops = &virtnet_netdev;
886    dev->features = NETIF_F_HIGHDMA;
887    SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
888    SET_NETDEV_DEV(dev, &vdev->dev);
889
890    /* Do we support "hardware" checksums? */
891    if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
892        /* This opens up the world of extra features. */
893        dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
894        if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
895            dev->features |= NETIF_F_TSO | NETIF_F_UFO
896                | NETIF_F_TSO_ECN | NETIF_F_TSO6;
897        }
898        /* Individual feature bits: what can host handle? */
899        if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
900            dev->features |= NETIF_F_TSO;
901        if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
902            dev->features |= NETIF_F_TSO6;
903        if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
904            dev->features |= NETIF_F_TSO_ECN;
905        if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
906            dev->features |= NETIF_F_UFO;
907    }
908
909    /* Configuration may specify what MAC to use. Otherwise random. */
910    if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
911        vdev->config->get(vdev,
912                  offsetof(struct virtio_net_config, mac),
913                  dev->dev_addr, dev->addr_len);
914    } else
915        random_ether_addr(dev->dev_addr);
916
917    /* Set up our device-specific information */
918    vi = netdev_priv(dev);
919    netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
920    vi->dev = dev;
921    vi->vdev = vdev;
922    vdev->priv = vi;
923    vi->pages = NULL;
924    INIT_DELAYED_WORK(&vi->refill, refill_work);
925
926    /* If they give us a callback when all buffers are done, we don't need
927     * the timer. */
928    vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
929
930    /* If we can receive ANY GSO packets, we must allocate large ones. */
931    if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
932        || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
933        || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
934        vi->big_packets = true;
935
936    if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
937        vi->mergeable_rx_bufs = true;
938
939    /* We expect two virtqueues, receive then send,
940     * and optionally control. */
941    nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
942
943    err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
944    if (err)
945        goto free;
946
947    vi->rvq = vqs[0];
948    vi->svq = vqs[1];
949
950    if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
951        vi->cvq = vqs[2];
952
953        if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
954            dev->features |= NETIF_F_HW_VLAN_FILTER;
955    }
956
957    /* Initialize our empty receive and send queues. */
958    skb_queue_head_init(&vi->recv);
959    skb_queue_head_init(&vi->send);
960
961    tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
962
963    if (!vi->free_in_tasklet)
964        setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
965
966    err = register_netdev(dev);
967    if (err) {
968        pr_debug("virtio_net: registering device failed\n");
969        goto free_vqs;
970    }
971
972    /* Last of all, set up some receive buffers. */
973    try_fill_recv(vi, GFP_KERNEL);
974
975    /* If we didn't even get one input buffer, we're useless. */
976    if (vi->num == 0) {
977        err = -ENOMEM;
978        goto unregister;
979    }
980
981    vi->status = VIRTIO_NET_S_LINK_UP;
982    virtnet_update_status(vi);
983    netif_carrier_on(dev);
984
985    pr_debug("virtnet: registered device %s\n", dev->name);
986    return 0;
987
988unregister:
989    unregister_netdev(dev);
990    cancel_delayed_work_sync(&vi->refill);
991free_vqs:
992    vdev->config->del_vqs(vdev);
993free:
994    free_netdev(dev);
995    return err;
996}
997
998static void virtnet_remove(struct virtio_device *vdev)
999{
1000    struct virtnet_info *vi = vdev->priv;
1001    struct sk_buff *skb;
1002
1003    /* Stop all the virtqueues. */
1004    vdev->config->reset(vdev);
1005
1006    if (!vi->free_in_tasklet)
1007        del_timer_sync(&vi->xmit_free_timer);
1008
1009    /* Free our skbs in send and recv queues, if any. */
1010    while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
1011        kfree_skb(skb);
1012        vi->num--;
1013    }
1014    __skb_queue_purge(&vi->send);
1015
1016    BUG_ON(vi->num != 0);
1017
1018    unregister_netdev(vi->dev);
1019    cancel_delayed_work_sync(&vi->refill);
1020
1021    vdev->config->del_vqs(vi->vdev);
1022
1023    while (vi->pages)
1024        __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1025
1026    free_netdev(vi->dev);
1027}
1028
1029static struct virtio_device_id id_table[] = {
1030    { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1031    { 0 },
1032};
1033
1034static unsigned int features[] = {
1035    VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1036    VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1037    VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1038    VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1039    VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
1040    VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1041    VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1042    VIRTIO_F_NOTIFY_ON_EMPTY,
1043};
1044
1045static struct virtio_driver virtio_net = {
1046    .feature_table = features,
1047    .feature_table_size = ARRAY_SIZE(features),
1048    .driver.name = KBUILD_MODNAME,
1049    .driver.owner = THIS_MODULE,
1050    .id_table = id_table,
1051    .probe = virtnet_probe,
1052    .remove = __devexit_p(virtnet_remove),
1053    .config_changed = virtnet_config_changed,
1054};
1055
1056static int __init init(void)
1057{
1058    return register_virtio_driver(&virtio_net);
1059}
1060
1061static void __exit fini(void)
1062{
1063    unregister_virtio_driver(&virtio_net);
1064}
1065module_init(init);
1066module_exit(fini);
1067
1068MODULE_DEVICE_TABLE(virtio, id_table);
1069MODULE_DESCRIPTION("Virtio network driver");
1070MODULE_LICENSE("GPL");
1071

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