Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-3.10.git] / drivers / net / virtio_net.c
1 /* A 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 #include <linux/slab.h>
29
30 static int napi_weight = 128;
31 module_param(napi_weight, int, 0444);
32
33 static bool csum = true, gso = true;
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 #define VIRTNET_DRIVER_VERSION "1.0.0"
43
44 struct virtnet_stats {
45         struct u64_stats_sync tx_syncp;
46         struct u64_stats_sync rx_syncp;
47         u64 tx_bytes;
48         u64 tx_packets;
49
50         u64 rx_bytes;
51         u64 rx_packets;
52 };
53
54 /* Internal representation of a send virtqueue */
55 struct send_queue {
56         /* Virtqueue associated with this send _queue */
57         struct virtqueue *vq;
58
59         /* TX: fragments + linear part + virtio header */
60         struct scatterlist sg[MAX_SKB_FRAGS + 2];
61
62         /* Name of the send queue: output.$index */
63         char name[40];
64 };
65
66 /* Internal representation of a receive virtqueue */
67 struct receive_queue {
68         /* Virtqueue associated with this receive_queue */
69         struct virtqueue *vq;
70
71         struct napi_struct napi;
72
73         /* Number of input buffers, and max we've ever had. */
74         unsigned int num, max;
75
76         /* Chain pages by the private ptr. */
77         struct page *pages;
78
79         /* RX: fragments + linear part + virtio header */
80         struct scatterlist sg[MAX_SKB_FRAGS + 2];
81
82         /* Name of this receive queue: input.$index */
83         char name[40];
84 };
85
86 struct virtnet_info {
87         struct virtio_device *vdev;
88         struct virtqueue *cvq;
89         struct net_device *dev;
90         struct send_queue *sq;
91         struct receive_queue *rq;
92         unsigned int status;
93
94         /* Max # of queue pairs supported by the device */
95         u16 max_queue_pairs;
96
97         /* # of queue pairs currently used by the driver */
98         u16 curr_queue_pairs;
99
100         /* I like... big packets and I cannot lie! */
101         bool big_packets;
102
103         /* Host will merge rx buffers for big packets (shake it! shake it!) */
104         bool mergeable_rx_bufs;
105
106         /* Has control virtqueue */
107         bool has_cvq;
108
109         /* enable config space updates */
110         bool config_enable;
111
112         /* Active statistics */
113         struct virtnet_stats __percpu *stats;
114
115         /* Work struct for refilling if we run low on memory. */
116         struct delayed_work refill;
117
118         /* Work struct for config space updates */
119         struct work_struct config_work;
120
121         /* Lock for config space updates */
122         struct mutex config_lock;
123
124         /* Does the affinity hint is set for virtqueues? */
125         bool affinity_hint_set;
126 };
127
128 struct skb_vnet_hdr {
129         union {
130                 struct virtio_net_hdr hdr;
131                 struct virtio_net_hdr_mrg_rxbuf mhdr;
132         };
133 };
134
135 struct padded_vnet_hdr {
136         struct virtio_net_hdr hdr;
137         /*
138          * virtio_net_hdr should be in a separated sg buffer because of a
139          * QEMU bug, and data sg buffer shares same page with this header sg.
140          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
141          */
142         char padding[6];
143 };
144
145 /* Converting between virtqueue no. and kernel tx/rx queue no.
146  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
147  */
148 static int vq2txq(struct virtqueue *vq)
149 {
150         return (virtqueue_get_queue_index(vq) - 1) / 2;
151 }
152
153 static int txq2vq(int txq)
154 {
155         return txq * 2 + 1;
156 }
157
158 static int vq2rxq(struct virtqueue *vq)
159 {
160         return virtqueue_get_queue_index(vq) / 2;
161 }
162
163 static int rxq2vq(int rxq)
164 {
165         return rxq * 2;
166 }
167
168 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
169 {
170         return (struct skb_vnet_hdr *)skb->cb;
171 }
172
173 /*
174  * private is used to chain pages for big packets, put the whole
175  * most recent used list in the beginning for reuse
176  */
177 static void give_pages(struct receive_queue *rq, struct page *page)
178 {
179         struct page *end;
180
181         /* Find end of list, sew whole thing into vi->rq.pages. */
182         for (end = page; end->private; end = (struct page *)end->private);
183         end->private = (unsigned long)rq->pages;
184         rq->pages = page;
185 }
186
187 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
188 {
189         struct page *p = rq->pages;
190
191         if (p) {
192                 rq->pages = (struct page *)p->private;
193                 /* clear private here, it is used to chain pages */
194                 p->private = 0;
195         } else
196                 p = alloc_page(gfp_mask);
197         return p;
198 }
199
200 static void skb_xmit_done(struct virtqueue *vq)
201 {
202         struct virtnet_info *vi = vq->vdev->priv;
203
204         /* Suppress further interrupts. */
205         virtqueue_disable_cb(vq);
206
207         /* We were probably waiting for more output buffers. */
208         netif_wake_subqueue(vi->dev, vq2txq(vq));
209 }
210
211 static void set_skb_frag(struct sk_buff *skb, struct page *page,
212                          unsigned int offset, unsigned int *len)
213 {
214         int size = min((unsigned)PAGE_SIZE - offset, *len);
215         int i = skb_shinfo(skb)->nr_frags;
216
217         __skb_fill_page_desc(skb, i, page, offset, size);
218
219         skb->data_len += size;
220         skb->len += size;
221         skb->truesize += PAGE_SIZE;
222         skb_shinfo(skb)->nr_frags++;
223         *len -= size;
224 }
225
226 /* Called from bottom half context */
227 static struct sk_buff *page_to_skb(struct receive_queue *rq,
228                                    struct page *page, unsigned int len)
229 {
230         struct virtnet_info *vi = rq->vq->vdev->priv;
231         struct sk_buff *skb;
232         struct skb_vnet_hdr *hdr;
233         unsigned int copy, hdr_len, offset;
234         char *p;
235
236         p = page_address(page);
237
238         /* copy small packet so we can reuse these pages for small data */
239         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
240         if (unlikely(!skb))
241                 return NULL;
242
243         hdr = skb_vnet_hdr(skb);
244
245         if (vi->mergeable_rx_bufs) {
246                 hdr_len = sizeof hdr->mhdr;
247                 offset = hdr_len;
248         } else {
249                 hdr_len = sizeof hdr->hdr;
250                 offset = sizeof(struct padded_vnet_hdr);
251         }
252
253         memcpy(hdr, p, hdr_len);
254
255         len -= hdr_len;
256         p += offset;
257
258         copy = len;
259         if (copy > skb_tailroom(skb))
260                 copy = skb_tailroom(skb);
261         memcpy(skb_put(skb, copy), p, copy);
262
263         len -= copy;
264         offset += copy;
265
266         /*
267          * Verify that we can indeed put this data into a skb.
268          * This is here to handle cases when the device erroneously
269          * tries to receive more than is possible. This is usually
270          * the case of a broken device.
271          */
272         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
273                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
274                 dev_kfree_skb(skb);
275                 return NULL;
276         }
277
278         while (len) {
279                 set_skb_frag(skb, page, offset, &len);
280                 page = (struct page *)page->private;
281                 offset = 0;
282         }
283
284         if (page)
285                 give_pages(rq, page);
286
287         return skb;
288 }
289
290 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
291 {
292         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
293         struct page *page;
294         int num_buf, i, len;
295
296         num_buf = hdr->mhdr.num_buffers;
297         while (--num_buf) {
298                 i = skb_shinfo(skb)->nr_frags;
299                 if (i >= MAX_SKB_FRAGS) {
300                         pr_debug("%s: packet too long\n", skb->dev->name);
301                         skb->dev->stats.rx_length_errors++;
302                         return -EINVAL;
303                 }
304                 page = virtqueue_get_buf(rq->vq, &len);
305                 if (!page) {
306                         pr_debug("%s: rx error: %d buffers missing\n",
307                                  skb->dev->name, hdr->mhdr.num_buffers);
308                         skb->dev->stats.rx_length_errors++;
309                         return -EINVAL;
310                 }
311
312                 if (len > PAGE_SIZE)
313                         len = PAGE_SIZE;
314
315                 set_skb_frag(skb, page, 0, &len);
316
317                 --rq->num;
318         }
319         return 0;
320 }
321
322 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
323 {
324         struct virtnet_info *vi = rq->vq->vdev->priv;
325         struct net_device *dev = vi->dev;
326         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
327         struct sk_buff *skb;
328         struct page *page;
329         struct skb_vnet_hdr *hdr;
330
331         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
332                 pr_debug("%s: short packet %i\n", dev->name, len);
333                 dev->stats.rx_length_errors++;
334                 if (vi->mergeable_rx_bufs || vi->big_packets)
335                         give_pages(rq, buf);
336                 else
337                         dev_kfree_skb(buf);
338                 return;
339         }
340
341         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
342                 skb = buf;
343                 len -= sizeof(struct virtio_net_hdr);
344                 skb_trim(skb, len);
345         } else {
346                 page = buf;
347                 skb = page_to_skb(rq, page, len);
348                 if (unlikely(!skb)) {
349                         dev->stats.rx_dropped++;
350                         give_pages(rq, page);
351                         return;
352                 }
353                 if (vi->mergeable_rx_bufs)
354                         if (receive_mergeable(rq, skb)) {
355                                 dev_kfree_skb(skb);
356                                 return;
357                         }
358         }
359
360         hdr = skb_vnet_hdr(skb);
361
362         u64_stats_update_begin(&stats->rx_syncp);
363         stats->rx_bytes += skb->len;
364         stats->rx_packets++;
365         u64_stats_update_end(&stats->rx_syncp);
366
367         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
368                 pr_debug("Needs csum!\n");
369                 if (!skb_partial_csum_set(skb,
370                                           hdr->hdr.csum_start,
371                                           hdr->hdr.csum_offset))
372                         goto frame_err;
373         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
374                 skb->ip_summed = CHECKSUM_UNNECESSARY;
375         }
376
377         skb->protocol = eth_type_trans(skb, dev);
378         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
379                  ntohs(skb->protocol), skb->len, skb->pkt_type);
380
381         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
382                 pr_debug("GSO!\n");
383                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
384                 case VIRTIO_NET_HDR_GSO_TCPV4:
385                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
386                         break;
387                 case VIRTIO_NET_HDR_GSO_UDP:
388                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
389                         break;
390                 case VIRTIO_NET_HDR_GSO_TCPV6:
391                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
392                         break;
393                 default:
394                         net_warn_ratelimited("%s: bad gso type %u.\n",
395                                              dev->name, hdr->hdr.gso_type);
396                         goto frame_err;
397                 }
398
399                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
400                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
401
402                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
403                 if (skb_shinfo(skb)->gso_size == 0) {
404                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
405                         goto frame_err;
406                 }
407
408                 /* Header must be checked, and gso_segs computed. */
409                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
410                 skb_shinfo(skb)->gso_segs = 0;
411         }
412
413         netif_receive_skb(skb);
414         return;
415
416 frame_err:
417         dev->stats.rx_frame_errors++;
418         dev_kfree_skb(skb);
419 }
420
421 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
422 {
423         struct virtnet_info *vi = rq->vq->vdev->priv;
424         struct sk_buff *skb;
425         struct skb_vnet_hdr *hdr;
426         int err;
427
428         skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
429         if (unlikely(!skb))
430                 return -ENOMEM;
431
432         skb_put(skb, MAX_PACKET_LEN);
433
434         hdr = skb_vnet_hdr(skb);
435         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
436
437         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
438
439         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp);
440         if (err < 0)
441                 dev_kfree_skb(skb);
442
443         return err;
444 }
445
446 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
447 {
448         struct page *first, *list = NULL;
449         char *p;
450         int i, err, offset;
451
452         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
453         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
454                 first = get_a_page(rq, gfp);
455                 if (!first) {
456                         if (list)
457                                 give_pages(rq, list);
458                         return -ENOMEM;
459                 }
460                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
461
462                 /* chain new page in list head to match sg */
463                 first->private = (unsigned long)list;
464                 list = first;
465         }
466
467         first = get_a_page(rq, gfp);
468         if (!first) {
469                 give_pages(rq, list);
470                 return -ENOMEM;
471         }
472         p = page_address(first);
473
474         /* rq->sg[0], rq->sg[1] share the same page */
475         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
476         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
477
478         /* rq->sg[1] for data packet, from offset */
479         offset = sizeof(struct padded_vnet_hdr);
480         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
481
482         /* chain first in list head */
483         first->private = (unsigned long)list;
484         err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2,
485                                 first, gfp);
486         if (err < 0)
487                 give_pages(rq, first);
488
489         return err;
490 }
491
492 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
493 {
494         struct page *page;
495         int err;
496
497         page = get_a_page(rq, gfp);
498         if (!page)
499                 return -ENOMEM;
500
501         sg_init_one(rq->sg, page_address(page), PAGE_SIZE);
502
503         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp);
504         if (err < 0)
505                 give_pages(rq, page);
506
507         return err;
508 }
509
510 /*
511  * Returns false if we couldn't fill entirely (OOM).
512  *
513  * Normally run in the receive path, but can also be run from ndo_open
514  * before we're receiving packets, or from refill_work which is
515  * careful to disable receiving (using napi_disable).
516  */
517 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
518 {
519         struct virtnet_info *vi = rq->vq->vdev->priv;
520         int err;
521         bool oom;
522
523         do {
524                 if (vi->mergeable_rx_bufs)
525                         err = add_recvbuf_mergeable(rq, gfp);
526                 else if (vi->big_packets)
527                         err = add_recvbuf_big(rq, gfp);
528                 else
529                         err = add_recvbuf_small(rq, gfp);
530
531                 oom = err == -ENOMEM;
532                 if (err)
533                         break;
534                 ++rq->num;
535         } while (rq->vq->num_free);
536         if (unlikely(rq->num > rq->max))
537                 rq->max = rq->num;
538         virtqueue_kick(rq->vq);
539         return !oom;
540 }
541
542 static void skb_recv_done(struct virtqueue *rvq)
543 {
544         struct virtnet_info *vi = rvq->vdev->priv;
545         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
546
547         /* Schedule NAPI, Suppress further interrupts if successful. */
548         if (napi_schedule_prep(&rq->napi)) {
549                 virtqueue_disable_cb(rvq);
550                 __napi_schedule(&rq->napi);
551         }
552 }
553
554 static void virtnet_napi_enable(struct receive_queue *rq)
555 {
556         napi_enable(&rq->napi);
557
558         /* If all buffers were filled by other side before we napi_enabled, we
559          * won't get another interrupt, so process any outstanding packets
560          * now.  virtnet_poll wants re-enable the queue, so we disable here.
561          * We synchronize against interrupts via NAPI_STATE_SCHED */
562         if (napi_schedule_prep(&rq->napi)) {
563                 virtqueue_disable_cb(rq->vq);
564                 local_bh_disable();
565                 __napi_schedule(&rq->napi);
566                 local_bh_enable();
567         }
568 }
569
570 static void refill_work(struct work_struct *work)
571 {
572         struct virtnet_info *vi =
573                 container_of(work, struct virtnet_info, refill.work);
574         bool still_empty;
575         int i;
576
577         for (i = 0; i < vi->max_queue_pairs; i++) {
578                 struct receive_queue *rq = &vi->rq[i];
579
580                 napi_disable(&rq->napi);
581                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
582                 virtnet_napi_enable(rq);
583
584                 /* In theory, this can happen: if we don't get any buffers in
585                  * we will *never* try to fill again.
586                  */
587                 if (still_empty)
588                         schedule_delayed_work(&vi->refill, HZ/2);
589         }
590 }
591
592 static int virtnet_poll(struct napi_struct *napi, int budget)
593 {
594         struct receive_queue *rq =
595                 container_of(napi, struct receive_queue, napi);
596         struct virtnet_info *vi = rq->vq->vdev->priv;
597         void *buf;
598         unsigned int len, received = 0;
599
600 again:
601         while (received < budget &&
602                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
603                 receive_buf(rq, buf, len);
604                 --rq->num;
605                 received++;
606         }
607
608         if (rq->num < rq->max / 2) {
609                 if (!try_fill_recv(rq, GFP_ATOMIC))
610                         schedule_delayed_work(&vi->refill, 0);
611         }
612
613         /* Out of packets? */
614         if (received < budget) {
615                 napi_complete(napi);
616                 if (unlikely(!virtqueue_enable_cb(rq->vq)) &&
617                     napi_schedule_prep(napi)) {
618                         virtqueue_disable_cb(rq->vq);
619                         __napi_schedule(napi);
620                         goto again;
621                 }
622         }
623
624         return received;
625 }
626
627 static int virtnet_open(struct net_device *dev)
628 {
629         struct virtnet_info *vi = netdev_priv(dev);
630         int i;
631
632         for (i = 0; i < vi->max_queue_pairs; i++) {
633                 /* Make sure we have some buffers: if oom use wq. */
634                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
635                         schedule_delayed_work(&vi->refill, 0);
636                 virtnet_napi_enable(&vi->rq[i]);
637         }
638
639         return 0;
640 }
641
642 static void free_old_xmit_skbs(struct send_queue *sq)
643 {
644         struct sk_buff *skb;
645         unsigned int len;
646         struct virtnet_info *vi = sq->vq->vdev->priv;
647         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
648
649         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
650                 pr_debug("Sent skb %p\n", skb);
651
652                 u64_stats_update_begin(&stats->tx_syncp);
653                 stats->tx_bytes += skb->len;
654                 stats->tx_packets++;
655                 u64_stats_update_end(&stats->tx_syncp);
656
657                 dev_kfree_skb_any(skb);
658         }
659 }
660
661 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
662 {
663         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
664         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
665         struct virtnet_info *vi = sq->vq->vdev->priv;
666         unsigned num_sg;
667
668         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
669
670         if (skb->ip_summed == CHECKSUM_PARTIAL) {
671                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
672                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
673                 hdr->hdr.csum_offset = skb->csum_offset;
674         } else {
675                 hdr->hdr.flags = 0;
676                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
677         }
678
679         if (skb_is_gso(skb)) {
680                 hdr->hdr.hdr_len = skb_headlen(skb);
681                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
682                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
683                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
684                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
685                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
686                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
687                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
688                 else
689                         BUG();
690                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
691                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
692         } else {
693                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
694                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
695         }
696
697         hdr->mhdr.num_buffers = 0;
698
699         /* Encode metadata header at front. */
700         if (vi->mergeable_rx_bufs)
701                 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
702         else
703                 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
704
705         num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
706         return virtqueue_add_buf(sq->vq, sq->sg, num_sg,
707                                  0, skb, GFP_ATOMIC);
708 }
709
710 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
711 {
712         struct virtnet_info *vi = netdev_priv(dev);
713         int qnum = skb_get_queue_mapping(skb);
714         struct send_queue *sq = &vi->sq[qnum];
715         int err;
716
717         /* Free up any pending old buffers before queueing new ones. */
718         free_old_xmit_skbs(sq);
719
720         /* Try to transmit */
721         err = xmit_skb(sq, skb);
722
723         /* This should not happen! */
724         if (unlikely(err)) {
725                 dev->stats.tx_fifo_errors++;
726                 if (net_ratelimit())
727                         dev_warn(&dev->dev,
728                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
729                 dev->stats.tx_dropped++;
730                 kfree_skb(skb);
731                 return NETDEV_TX_OK;
732         }
733         virtqueue_kick(sq->vq);
734
735         /* Don't wait up for transmitted skbs to be freed. */
736         skb_orphan(skb);
737         nf_reset(skb);
738
739         /* Apparently nice girls don't return TX_BUSY; stop the queue
740          * before it gets out of hand.  Naturally, this wastes entries. */
741         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
742                 netif_stop_subqueue(dev, qnum);
743                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
744                         /* More just got used, free them then recheck. */
745                         free_old_xmit_skbs(sq);
746                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
747                                 netif_start_subqueue(dev, qnum);
748                                 virtqueue_disable_cb(sq->vq);
749                         }
750                 }
751         }
752
753         return NETDEV_TX_OK;
754 }
755
756 static int virtnet_set_mac_address(struct net_device *dev, void *p)
757 {
758         struct virtnet_info *vi = netdev_priv(dev);
759         struct virtio_device *vdev = vi->vdev;
760         int ret;
761
762         ret = eth_mac_addr(dev, p);
763         if (ret)
764                 return ret;
765
766         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
767                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
768                                   dev->dev_addr, dev->addr_len);
769
770         return 0;
771 }
772
773 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
774                                                struct rtnl_link_stats64 *tot)
775 {
776         struct virtnet_info *vi = netdev_priv(dev);
777         int cpu;
778         unsigned int start;
779
780         for_each_possible_cpu(cpu) {
781                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
782                 u64 tpackets, tbytes, rpackets, rbytes;
783
784                 do {
785                         start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
786                         tpackets = stats->tx_packets;
787                         tbytes   = stats->tx_bytes;
788                 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
789
790                 do {
791                         start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
792                         rpackets = stats->rx_packets;
793                         rbytes   = stats->rx_bytes;
794                 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
795
796                 tot->rx_packets += rpackets;
797                 tot->tx_packets += tpackets;
798                 tot->rx_bytes   += rbytes;
799                 tot->tx_bytes   += tbytes;
800         }
801
802         tot->tx_dropped = dev->stats.tx_dropped;
803         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
804         tot->rx_dropped = dev->stats.rx_dropped;
805         tot->rx_length_errors = dev->stats.rx_length_errors;
806         tot->rx_frame_errors = dev->stats.rx_frame_errors;
807
808         return tot;
809 }
810
811 #ifdef CONFIG_NET_POLL_CONTROLLER
812 static void virtnet_netpoll(struct net_device *dev)
813 {
814         struct virtnet_info *vi = netdev_priv(dev);
815         int i;
816
817         for (i = 0; i < vi->curr_queue_pairs; i++)
818                 napi_schedule(&vi->rq[i].napi);
819 }
820 #endif
821
822 /*
823  * Send command via the control virtqueue and check status.  Commands
824  * supported by the hypervisor, as indicated by feature bits, should
825  * never fail unless improperly formated.
826  */
827 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
828                                  struct scatterlist *data, int out, int in)
829 {
830         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
831         struct virtio_net_ctrl_hdr ctrl;
832         virtio_net_ctrl_ack status = ~0;
833         unsigned int tmp;
834         int i;
835
836         /* Caller should know better */
837         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
838                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
839
840         out++; /* Add header */
841         in++; /* Add return status */
842
843         ctrl.class = class;
844         ctrl.cmd = cmd;
845
846         sg_init_table(sg, out + in);
847
848         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
849         for_each_sg(data, s, out + in - 2, i)
850                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
851         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
852
853         BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
854
855         virtqueue_kick(vi->cvq);
856
857         /*
858          * Spin for a response, the kick causes an ioport write, trapping
859          * into the hypervisor, so the request should be handled immediately.
860          */
861         while (!virtqueue_get_buf(vi->cvq, &tmp))
862                 cpu_relax();
863
864         return status == VIRTIO_NET_OK;
865 }
866
867 static void virtnet_ack_link_announce(struct virtnet_info *vi)
868 {
869         rtnl_lock();
870         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
871                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
872                                   0, 0))
873                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
874         rtnl_unlock();
875 }
876
877 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
878 {
879         struct scatterlist sg;
880         struct virtio_net_ctrl_mq s;
881         struct net_device *dev = vi->dev;
882
883         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
884                 return 0;
885
886         s.virtqueue_pairs = queue_pairs;
887         sg_init_one(&sg, &s, sizeof(s));
888
889         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
890                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){
891                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
892                          queue_pairs);
893                 return -EINVAL;
894         } else
895                 vi->curr_queue_pairs = queue_pairs;
896
897         return 0;
898 }
899
900 static int virtnet_close(struct net_device *dev)
901 {
902         struct virtnet_info *vi = netdev_priv(dev);
903         int i;
904
905         /* Make sure refill_work doesn't re-enable napi! */
906         cancel_delayed_work_sync(&vi->refill);
907
908         for (i = 0; i < vi->max_queue_pairs; i++)
909                 napi_disable(&vi->rq[i].napi);
910
911         return 0;
912 }
913
914 static void virtnet_set_rx_mode(struct net_device *dev)
915 {
916         struct virtnet_info *vi = netdev_priv(dev);
917         struct scatterlist sg[2];
918         u8 promisc, allmulti;
919         struct virtio_net_ctrl_mac *mac_data;
920         struct netdev_hw_addr *ha;
921         int uc_count;
922         int mc_count;
923         void *buf;
924         int i;
925
926         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
927         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
928                 return;
929
930         promisc = ((dev->flags & IFF_PROMISC) != 0);
931         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
932
933         sg_init_one(sg, &promisc, sizeof(promisc));
934
935         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
936                                   VIRTIO_NET_CTRL_RX_PROMISC,
937                                   sg, 1, 0))
938                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
939                          promisc ? "en" : "dis");
940
941         sg_init_one(sg, &allmulti, sizeof(allmulti));
942
943         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
944                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
945                                   sg, 1, 0))
946                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
947                          allmulti ? "en" : "dis");
948
949         uc_count = netdev_uc_count(dev);
950         mc_count = netdev_mc_count(dev);
951         /* MAC filter - use one buffer for both lists */
952         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
953                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
954         mac_data = buf;
955         if (!buf) {
956                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
957                 return;
958         }
959
960         sg_init_table(sg, 2);
961
962         /* Store the unicast list and count in the front of the buffer */
963         mac_data->entries = uc_count;
964         i = 0;
965         netdev_for_each_uc_addr(ha, dev)
966                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
967
968         sg_set_buf(&sg[0], mac_data,
969                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
970
971         /* multicast list and count fill the end */
972         mac_data = (void *)&mac_data->macs[uc_count][0];
973
974         mac_data->entries = mc_count;
975         i = 0;
976         netdev_for_each_mc_addr(ha, dev)
977                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
978
979         sg_set_buf(&sg[1], mac_data,
980                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
981
982         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
983                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
984                                   sg, 2, 0))
985                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
986
987         kfree(buf);
988 }
989
990 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
991 {
992         struct virtnet_info *vi = netdev_priv(dev);
993         struct scatterlist sg;
994
995         sg_init_one(&sg, &vid, sizeof(vid));
996
997         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
998                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
999                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1000         return 0;
1001 }
1002
1003 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
1004 {
1005         struct virtnet_info *vi = netdev_priv(dev);
1006         struct scatterlist sg;
1007
1008         sg_init_one(&sg, &vid, sizeof(vid));
1009
1010         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1011                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
1012                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1013         return 0;
1014 }
1015
1016 static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
1017 {
1018         int i;
1019
1020         /* In multiqueue mode, when the number of cpu is equal to the number of
1021          * queue pairs, we let the queue pairs to be private to one cpu by
1022          * setting the affinity hint to eliminate the contention.
1023          */
1024         if ((vi->curr_queue_pairs == 1 ||
1025              vi->max_queue_pairs != num_online_cpus()) && set) {
1026                 if (vi->affinity_hint_set)
1027                         set = false;
1028                 else
1029                         return;
1030         }
1031
1032         for (i = 0; i < vi->max_queue_pairs; i++) {
1033                 int cpu = set ? i : -1;
1034                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1035                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1036         }
1037
1038         if (set)
1039                 vi->affinity_hint_set = true;
1040         else
1041                 vi->affinity_hint_set = false;
1042 }
1043
1044 static void virtnet_get_ringparam(struct net_device *dev,
1045                                 struct ethtool_ringparam *ring)
1046 {
1047         struct virtnet_info *vi = netdev_priv(dev);
1048
1049         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1050         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1051         ring->rx_pending = ring->rx_max_pending;
1052         ring->tx_pending = ring->tx_max_pending;
1053 }
1054
1055
1056 static void virtnet_get_drvinfo(struct net_device *dev,
1057                                 struct ethtool_drvinfo *info)
1058 {
1059         struct virtnet_info *vi = netdev_priv(dev);
1060         struct virtio_device *vdev = vi->vdev;
1061
1062         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1063         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1064         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1065
1066 }
1067
1068 /* TODO: Eliminate OOO packets during switching */
1069 static int virtnet_set_channels(struct net_device *dev,
1070                                 struct ethtool_channels *channels)
1071 {
1072         struct virtnet_info *vi = netdev_priv(dev);
1073         u16 queue_pairs = channels->combined_count;
1074         int err;
1075
1076         /* We don't support separate rx/tx channels.
1077          * We don't allow setting 'other' channels.
1078          */
1079         if (channels->rx_count || channels->tx_count || channels->other_count)
1080                 return -EINVAL;
1081
1082         if (queue_pairs > vi->max_queue_pairs)
1083                 return -EINVAL;
1084
1085         err = virtnet_set_queues(vi, queue_pairs);
1086         if (!err) {
1087                 netif_set_real_num_tx_queues(dev, queue_pairs);
1088                 netif_set_real_num_rx_queues(dev, queue_pairs);
1089
1090                 virtnet_set_affinity(vi, true);
1091         }
1092
1093         return err;
1094 }
1095
1096 static void virtnet_get_channels(struct net_device *dev,
1097                                  struct ethtool_channels *channels)
1098 {
1099         struct virtnet_info *vi = netdev_priv(dev);
1100
1101         channels->combined_count = vi->curr_queue_pairs;
1102         channels->max_combined = vi->max_queue_pairs;
1103         channels->max_other = 0;
1104         channels->rx_count = 0;
1105         channels->tx_count = 0;
1106         channels->other_count = 0;
1107 }
1108
1109 static const struct ethtool_ops virtnet_ethtool_ops = {
1110         .get_drvinfo = virtnet_get_drvinfo,
1111         .get_link = ethtool_op_get_link,
1112         .get_ringparam = virtnet_get_ringparam,
1113         .set_channels = virtnet_set_channels,
1114         .get_channels = virtnet_get_channels,
1115 };
1116
1117 #define MIN_MTU 68
1118 #define MAX_MTU 65535
1119
1120 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1121 {
1122         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1123                 return -EINVAL;
1124         dev->mtu = new_mtu;
1125         return 0;
1126 }
1127
1128 /* To avoid contending a lock hold by a vcpu who would exit to host, select the
1129  * txq based on the processor id.
1130  * TODO: handle cpu hotplug.
1131  */
1132 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
1133 {
1134         int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) :
1135                   smp_processor_id();
1136
1137         while (unlikely(txq >= dev->real_num_tx_queues))
1138                 txq -= dev->real_num_tx_queues;
1139
1140         return txq;
1141 }
1142
1143 static const struct net_device_ops virtnet_netdev = {
1144         .ndo_open            = virtnet_open,
1145         .ndo_stop            = virtnet_close,
1146         .ndo_start_xmit      = start_xmit,
1147         .ndo_validate_addr   = eth_validate_addr,
1148         .ndo_set_mac_address = virtnet_set_mac_address,
1149         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1150         .ndo_change_mtu      = virtnet_change_mtu,
1151         .ndo_get_stats64     = virtnet_stats,
1152         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1153         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1154         .ndo_select_queue     = virtnet_select_queue,
1155 #ifdef CONFIG_NET_POLL_CONTROLLER
1156         .ndo_poll_controller = virtnet_netpoll,
1157 #endif
1158 };
1159
1160 static void virtnet_config_changed_work(struct work_struct *work)
1161 {
1162         struct virtnet_info *vi =
1163                 container_of(work, struct virtnet_info, config_work);
1164         u16 v;
1165
1166         mutex_lock(&vi->config_lock);
1167         if (!vi->config_enable)
1168                 goto done;
1169
1170         if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
1171                               offsetof(struct virtio_net_config, status),
1172                               &v) < 0)
1173                 goto done;
1174
1175         if (v & VIRTIO_NET_S_ANNOUNCE) {
1176                 netdev_notify_peers(vi->dev);
1177                 virtnet_ack_link_announce(vi);
1178         }
1179
1180         /* Ignore unknown (future) status bits */
1181         v &= VIRTIO_NET_S_LINK_UP;
1182
1183         if (vi->status == v)
1184                 goto done;
1185
1186         vi->status = v;
1187
1188         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1189                 netif_carrier_on(vi->dev);
1190                 netif_tx_wake_all_queues(vi->dev);
1191         } else {
1192                 netif_carrier_off(vi->dev);
1193                 netif_tx_stop_all_queues(vi->dev);
1194         }
1195 done:
1196         mutex_unlock(&vi->config_lock);
1197 }
1198
1199 static void virtnet_config_changed(struct virtio_device *vdev)
1200 {
1201         struct virtnet_info *vi = vdev->priv;
1202
1203         schedule_work(&vi->config_work);
1204 }
1205
1206 static void virtnet_free_queues(struct virtnet_info *vi)
1207 {
1208         kfree(vi->rq);
1209         kfree(vi->sq);
1210 }
1211
1212 static void free_receive_bufs(struct virtnet_info *vi)
1213 {
1214         int i;
1215
1216         for (i = 0; i < vi->max_queue_pairs; i++) {
1217                 while (vi->rq[i].pages)
1218                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1219         }
1220 }
1221
1222 static void free_unused_bufs(struct virtnet_info *vi)
1223 {
1224         void *buf;
1225         int i;
1226
1227         for (i = 0; i < vi->max_queue_pairs; i++) {
1228                 struct virtqueue *vq = vi->sq[i].vq;
1229                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1230                         dev_kfree_skb(buf);
1231         }
1232
1233         for (i = 0; i < vi->max_queue_pairs; i++) {
1234                 struct virtqueue *vq = vi->rq[i].vq;
1235
1236                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1237                         if (vi->mergeable_rx_bufs || vi->big_packets)
1238                                 give_pages(&vi->rq[i], buf);
1239                         else
1240                                 dev_kfree_skb(buf);
1241                         --vi->rq[i].num;
1242                 }
1243                 BUG_ON(vi->rq[i].num != 0);
1244         }
1245 }
1246
1247 static void virtnet_del_vqs(struct virtnet_info *vi)
1248 {
1249         struct virtio_device *vdev = vi->vdev;
1250
1251         virtnet_set_affinity(vi, false);
1252
1253         vdev->config->del_vqs(vdev);
1254
1255         virtnet_free_queues(vi);
1256 }
1257
1258 static int virtnet_find_vqs(struct virtnet_info *vi)
1259 {
1260         vq_callback_t **callbacks;
1261         struct virtqueue **vqs;
1262         int ret = -ENOMEM;
1263         int i, total_vqs;
1264         const char **names;
1265
1266         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1267          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1268          * possible control vq.
1269          */
1270         total_vqs = vi->max_queue_pairs * 2 +
1271                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1272
1273         /* Allocate space for find_vqs parameters */
1274         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1275         if (!vqs)
1276                 goto err_vq;
1277         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1278         if (!callbacks)
1279                 goto err_callback;
1280         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1281         if (!names)
1282                 goto err_names;
1283
1284         /* Parameters for control virtqueue, if any */
1285         if (vi->has_cvq) {
1286                 callbacks[total_vqs - 1] = NULL;
1287                 names[total_vqs - 1] = "control";
1288         }
1289
1290         /* Allocate/initialize parameters for send/receive virtqueues */
1291         for (i = 0; i < vi->max_queue_pairs; i++) {
1292                 callbacks[rxq2vq(i)] = skb_recv_done;
1293                 callbacks[txq2vq(i)] = skb_xmit_done;
1294                 sprintf(vi->rq[i].name, "input.%d", i);
1295                 sprintf(vi->sq[i].name, "output.%d", i);
1296                 names[rxq2vq(i)] = vi->rq[i].name;
1297                 names[txq2vq(i)] = vi->sq[i].name;
1298         }
1299
1300         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1301                                          names);
1302         if (ret)
1303                 goto err_find;
1304
1305         if (vi->has_cvq) {
1306                 vi->cvq = vqs[total_vqs - 1];
1307                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1308                         vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1309         }
1310
1311         for (i = 0; i < vi->max_queue_pairs; i++) {
1312                 vi->rq[i].vq = vqs[rxq2vq(i)];
1313                 vi->sq[i].vq = vqs[txq2vq(i)];
1314         }
1315
1316         kfree(names);
1317         kfree(callbacks);
1318         kfree(vqs);
1319
1320         return 0;
1321
1322 err_find:
1323         kfree(names);
1324 err_names:
1325         kfree(callbacks);
1326 err_callback:
1327         kfree(vqs);
1328 err_vq:
1329         return ret;
1330 }
1331
1332 static int virtnet_alloc_queues(struct virtnet_info *vi)
1333 {
1334         int i;
1335
1336         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1337         if (!vi->sq)
1338                 goto err_sq;
1339         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1340         if (!vi->rq)
1341                 goto err_rq;
1342
1343         INIT_DELAYED_WORK(&vi->refill, refill_work);
1344         for (i = 0; i < vi->max_queue_pairs; i++) {
1345                 vi->rq[i].pages = NULL;
1346                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1347                                napi_weight);
1348
1349                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1350                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1351         }
1352
1353         return 0;
1354
1355 err_rq:
1356         kfree(vi->sq);
1357 err_sq:
1358         return -ENOMEM;
1359 }
1360
1361 static int init_vqs(struct virtnet_info *vi)
1362 {
1363         int ret;
1364
1365         /* Allocate send & receive queues */
1366         ret = virtnet_alloc_queues(vi);
1367         if (ret)
1368                 goto err;
1369
1370         ret = virtnet_find_vqs(vi);
1371         if (ret)
1372                 goto err_free;
1373
1374         virtnet_set_affinity(vi, true);
1375         return 0;
1376
1377 err_free:
1378         virtnet_free_queues(vi);
1379 err:
1380         return ret;
1381 }
1382
1383 static int virtnet_probe(struct virtio_device *vdev)
1384 {
1385         int i, err;
1386         struct net_device *dev;
1387         struct virtnet_info *vi;
1388         u16 max_queue_pairs;
1389
1390         /* Find if host supports multiqueue virtio_net device */
1391         err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
1392                                 offsetof(struct virtio_net_config,
1393                                 max_virtqueue_pairs), &max_queue_pairs);
1394
1395         /* We need at least 2 queue's */
1396         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1397             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1398             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1399                 max_queue_pairs = 1;
1400
1401         /* Allocate ourselves a network device with room for our info */
1402         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1403         if (!dev)
1404                 return -ENOMEM;
1405
1406         /* Set up network device as normal. */
1407         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1408         dev->netdev_ops = &virtnet_netdev;
1409         dev->features = NETIF_F_HIGHDMA;
1410
1411         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1412         SET_NETDEV_DEV(dev, &vdev->dev);
1413
1414         /* Do we support "hardware" checksums? */
1415         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1416                 /* This opens up the world of extra features. */
1417                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1418                 if (csum)
1419                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1420
1421                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1422                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1423                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1424                 }
1425                 /* Individual feature bits: what can host handle? */
1426                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1427                         dev->hw_features |= NETIF_F_TSO;
1428                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1429                         dev->hw_features |= NETIF_F_TSO6;
1430                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1431                         dev->hw_features |= NETIF_F_TSO_ECN;
1432                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1433                         dev->hw_features |= NETIF_F_UFO;
1434
1435                 if (gso)
1436                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1437                 /* (!csum && gso) case will be fixed by register_netdev() */
1438         }
1439
1440         /* Configuration may specify what MAC to use.  Otherwise random. */
1441         if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1442                                   offsetof(struct virtio_net_config, mac),
1443                                   dev->dev_addr, dev->addr_len) < 0)
1444                 eth_hw_addr_random(dev);
1445
1446         /* Set up our device-specific information */
1447         vi = netdev_priv(dev);
1448         vi->dev = dev;
1449         vi->vdev = vdev;
1450         vdev->priv = vi;
1451         vi->stats = alloc_percpu(struct virtnet_stats);
1452         err = -ENOMEM;
1453         if (vi->stats == NULL)
1454                 goto free;
1455
1456         mutex_init(&vi->config_lock);
1457         vi->config_enable = true;
1458         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1459
1460         /* If we can receive ANY GSO packets, we must allocate large ones. */
1461         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1462             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1463             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1464                 vi->big_packets = true;
1465
1466         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1467                 vi->mergeable_rx_bufs = true;
1468
1469         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1470                 vi->has_cvq = true;
1471
1472         /* Use single tx/rx queue pair as default */
1473         vi->curr_queue_pairs = 1;
1474         vi->max_queue_pairs = max_queue_pairs;
1475
1476         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1477         err = init_vqs(vi);
1478         if (err)
1479                 goto free_stats;
1480
1481         netif_set_real_num_tx_queues(dev, 1);
1482         netif_set_real_num_rx_queues(dev, 1);
1483
1484         err = register_netdev(dev);
1485         if (err) {
1486                 pr_debug("virtio_net: registering device failed\n");
1487                 goto free_vqs;
1488         }
1489
1490         /* Last of all, set up some receive buffers. */
1491         for (i = 0; i < vi->max_queue_pairs; i++) {
1492                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1493
1494                 /* If we didn't even get one input buffer, we're useless. */
1495                 if (vi->rq[i].num == 0) {
1496                         free_unused_bufs(vi);
1497                         err = -ENOMEM;
1498                         goto free_recv_bufs;
1499                 }
1500         }
1501
1502         /* Assume link up if device can't report link status,
1503            otherwise get link status from config. */
1504         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1505                 netif_carrier_off(dev);
1506                 schedule_work(&vi->config_work);
1507         } else {
1508                 vi->status = VIRTIO_NET_S_LINK_UP;
1509                 netif_carrier_on(dev);
1510         }
1511
1512         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1513                  dev->name, max_queue_pairs);
1514
1515         return 0;
1516
1517 free_recv_bufs:
1518         free_receive_bufs(vi);
1519         unregister_netdev(dev);
1520 free_vqs:
1521         cancel_delayed_work_sync(&vi->refill);
1522         virtnet_del_vqs(vi);
1523 free_stats:
1524         free_percpu(vi->stats);
1525 free:
1526         free_netdev(dev);
1527         return err;
1528 }
1529
1530 static void remove_vq_common(struct virtnet_info *vi)
1531 {
1532         vi->vdev->config->reset(vi->vdev);
1533
1534         /* Free unused buffers in both send and recv, if any. */
1535         free_unused_bufs(vi);
1536
1537         free_receive_bufs(vi);
1538
1539         virtnet_del_vqs(vi);
1540 }
1541
1542 static void virtnet_remove(struct virtio_device *vdev)
1543 {
1544         struct virtnet_info *vi = vdev->priv;
1545
1546         /* Prevent config work handler from accessing the device. */
1547         mutex_lock(&vi->config_lock);
1548         vi->config_enable = false;
1549         mutex_unlock(&vi->config_lock);
1550
1551         unregister_netdev(vi->dev);
1552
1553         remove_vq_common(vi);
1554
1555         flush_work(&vi->config_work);
1556
1557         free_percpu(vi->stats);
1558         free_netdev(vi->dev);
1559 }
1560
1561 #ifdef CONFIG_PM
1562 static int virtnet_freeze(struct virtio_device *vdev)
1563 {
1564         struct virtnet_info *vi = vdev->priv;
1565         int i;
1566
1567         /* Prevent config work handler from accessing the device */
1568         mutex_lock(&vi->config_lock);
1569         vi->config_enable = false;
1570         mutex_unlock(&vi->config_lock);
1571
1572         netif_device_detach(vi->dev);
1573         cancel_delayed_work_sync(&vi->refill);
1574
1575         if (netif_running(vi->dev))
1576                 for (i = 0; i < vi->max_queue_pairs; i++) {
1577                         napi_disable(&vi->rq[i].napi);
1578                         netif_napi_del(&vi->rq[i].napi);
1579                 }
1580
1581         remove_vq_common(vi);
1582
1583         flush_work(&vi->config_work);
1584
1585         return 0;
1586 }
1587
1588 static int virtnet_restore(struct virtio_device *vdev)
1589 {
1590         struct virtnet_info *vi = vdev->priv;
1591         int err, i;
1592
1593         err = init_vqs(vi);
1594         if (err)
1595                 return err;
1596
1597         if (netif_running(vi->dev))
1598                 for (i = 0; i < vi->max_queue_pairs; i++)
1599                         virtnet_napi_enable(&vi->rq[i]);
1600
1601         netif_device_attach(vi->dev);
1602
1603         for (i = 0; i < vi->max_queue_pairs; i++)
1604                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1605                         schedule_delayed_work(&vi->refill, 0);
1606
1607         mutex_lock(&vi->config_lock);
1608         vi->config_enable = true;
1609         mutex_unlock(&vi->config_lock);
1610
1611         virtnet_set_queues(vi, vi->curr_queue_pairs);
1612
1613         return 0;
1614 }
1615 #endif
1616
1617 static struct virtio_device_id id_table[] = {
1618         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1619         { 0 },
1620 };
1621
1622 static unsigned int features[] = {
1623         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1624         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1625         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1626         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1627         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1628         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1629         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1630         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1631 };
1632
1633 static struct virtio_driver virtio_net_driver = {
1634         .feature_table = features,
1635         .feature_table_size = ARRAY_SIZE(features),
1636         .driver.name =  KBUILD_MODNAME,
1637         .driver.owner = THIS_MODULE,
1638         .id_table =     id_table,
1639         .probe =        virtnet_probe,
1640         .remove =       virtnet_remove,
1641         .config_changed = virtnet_config_changed,
1642 #ifdef CONFIG_PM
1643         .freeze =       virtnet_freeze,
1644         .restore =      virtnet_restore,
1645 #endif
1646 };
1647
1648 static int __init init(void)
1649 {
1650         return register_virtio_driver(&virtio_net_driver);
1651 }
1652
1653 static void __exit fini(void)
1654 {
1655         unregister_virtio_driver(&virtio_net_driver);
1656 }
1657 module_init(init);
1658 module_exit(fini);
1659
1660 MODULE_DEVICE_TABLE(virtio, id_table);
1661 MODULE_DESCRIPTION("Virtio network driver");
1662 MODULE_LICENSE("GPL");