Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[~shefty/rdma-dev.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 #include <linux/cpu.h>
30
31 static int napi_weight = 128;
32 module_param(napi_weight, int, 0444);
33
34 static bool csum = true, gso = true;
35 module_param(csum, bool, 0444);
36 module_param(gso, bool, 0444);
37
38 /* FIXME: MTU in config. */
39 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
40 #define GOOD_COPY_LEN   128
41
42 #define VIRTNET_SEND_COMMAND_SG_MAX    2
43 #define VIRTNET_DRIVER_VERSION "1.0.0"
44
45 struct virtnet_stats {
46         struct u64_stats_sync tx_syncp;
47         struct u64_stats_sync rx_syncp;
48         u64 tx_bytes;
49         u64 tx_packets;
50
51         u64 rx_bytes;
52         u64 rx_packets;
53 };
54
55 /* Internal representation of a send virtqueue */
56 struct send_queue {
57         /* Virtqueue associated with this send _queue */
58         struct virtqueue *vq;
59
60         /* TX: fragments + linear part + virtio header */
61         struct scatterlist sg[MAX_SKB_FRAGS + 2];
62
63         /* Name of the send queue: output.$index */
64         char name[40];
65 };
66
67 /* Internal representation of a receive virtqueue */
68 struct receive_queue {
69         /* Virtqueue associated with this receive_queue */
70         struct virtqueue *vq;
71
72         struct napi_struct napi;
73
74         /* Number of input buffers, and max we've ever had. */
75         unsigned int num, max;
76
77         /* Chain pages by the private ptr. */
78         struct page *pages;
79
80         /* RX: fragments + linear part + virtio header */
81         struct scatterlist sg[MAX_SKB_FRAGS + 2];
82
83         /* Name of this receive queue: input.$index */
84         char name[40];
85 };
86
87 struct virtnet_info {
88         struct virtio_device *vdev;
89         struct virtqueue *cvq;
90         struct net_device *dev;
91         struct send_queue *sq;
92         struct receive_queue *rq;
93         unsigned int status;
94
95         /* Max # of queue pairs supported by the device */
96         u16 max_queue_pairs;
97
98         /* # of queue pairs currently used by the driver */
99         u16 curr_queue_pairs;
100
101         /* I like... big packets and I cannot lie! */
102         bool big_packets;
103
104         /* Host will merge rx buffers for big packets (shake it! shake it!) */
105         bool mergeable_rx_bufs;
106
107         /* Has control virtqueue */
108         bool has_cvq;
109
110         /* enable config space updates */
111         bool config_enable;
112
113         /* Active statistics */
114         struct virtnet_stats __percpu *stats;
115
116         /* Work struct for refilling if we run low on memory. */
117         struct delayed_work refill;
118
119         /* Work struct for config space updates */
120         struct work_struct config_work;
121
122         /* Lock for config space updates */
123         struct mutex config_lock;
124
125         /* Does the affinity hint is set for virtqueues? */
126         bool affinity_hint_set;
127
128         /* Per-cpu variable to show the mapping from CPU to virtqueue */
129         int __percpu *vq_index;
130
131         /* CPU hot plug notifier */
132         struct notifier_block nb;
133 };
134
135 struct skb_vnet_hdr {
136         union {
137                 struct virtio_net_hdr hdr;
138                 struct virtio_net_hdr_mrg_rxbuf mhdr;
139         };
140 };
141
142 struct padded_vnet_hdr {
143         struct virtio_net_hdr hdr;
144         /*
145          * virtio_net_hdr should be in a separated sg buffer because of a
146          * QEMU bug, and data sg buffer shares same page with this header sg.
147          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
148          */
149         char padding[6];
150 };
151
152 /* Converting between virtqueue no. and kernel tx/rx queue no.
153  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
154  */
155 static int vq2txq(struct virtqueue *vq)
156 {
157         return (virtqueue_get_queue_index(vq) - 1) / 2;
158 }
159
160 static int txq2vq(int txq)
161 {
162         return txq * 2 + 1;
163 }
164
165 static int vq2rxq(struct virtqueue *vq)
166 {
167         return virtqueue_get_queue_index(vq) / 2;
168 }
169
170 static int rxq2vq(int rxq)
171 {
172         return rxq * 2;
173 }
174
175 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
176 {
177         return (struct skb_vnet_hdr *)skb->cb;
178 }
179
180 /*
181  * private is used to chain pages for big packets, put the whole
182  * most recent used list in the beginning for reuse
183  */
184 static void give_pages(struct receive_queue *rq, struct page *page)
185 {
186         struct page *end;
187
188         /* Find end of list, sew whole thing into vi->rq.pages. */
189         for (end = page; end->private; end = (struct page *)end->private);
190         end->private = (unsigned long)rq->pages;
191         rq->pages = page;
192 }
193
194 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
195 {
196         struct page *p = rq->pages;
197
198         if (p) {
199                 rq->pages = (struct page *)p->private;
200                 /* clear private here, it is used to chain pages */
201                 p->private = 0;
202         } else
203                 p = alloc_page(gfp_mask);
204         return p;
205 }
206
207 static void skb_xmit_done(struct virtqueue *vq)
208 {
209         struct virtnet_info *vi = vq->vdev->priv;
210
211         /* Suppress further interrupts. */
212         virtqueue_disable_cb(vq);
213
214         /* We were probably waiting for more output buffers. */
215         netif_wake_subqueue(vi->dev, vq2txq(vq));
216 }
217
218 static void set_skb_frag(struct sk_buff *skb, struct page *page,
219                          unsigned int offset, unsigned int *len)
220 {
221         int size = min((unsigned)PAGE_SIZE - offset, *len);
222         int i = skb_shinfo(skb)->nr_frags;
223
224         __skb_fill_page_desc(skb, i, page, offset, size);
225
226         skb->data_len += size;
227         skb->len += size;
228         skb->truesize += PAGE_SIZE;
229         skb_shinfo(skb)->nr_frags++;
230         skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
231         *len -= size;
232 }
233
234 /* Called from bottom half context */
235 static struct sk_buff *page_to_skb(struct receive_queue *rq,
236                                    struct page *page, unsigned int len)
237 {
238         struct virtnet_info *vi = rq->vq->vdev->priv;
239         struct sk_buff *skb;
240         struct skb_vnet_hdr *hdr;
241         unsigned int copy, hdr_len, offset;
242         char *p;
243
244         p = page_address(page);
245
246         /* copy small packet so we can reuse these pages for small data */
247         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
248         if (unlikely(!skb))
249                 return NULL;
250
251         hdr = skb_vnet_hdr(skb);
252
253         if (vi->mergeable_rx_bufs) {
254                 hdr_len = sizeof hdr->mhdr;
255                 offset = hdr_len;
256         } else {
257                 hdr_len = sizeof hdr->hdr;
258                 offset = sizeof(struct padded_vnet_hdr);
259         }
260
261         memcpy(hdr, p, hdr_len);
262
263         len -= hdr_len;
264         p += offset;
265
266         copy = len;
267         if (copy > skb_tailroom(skb))
268                 copy = skb_tailroom(skb);
269         memcpy(skb_put(skb, copy), p, copy);
270
271         len -= copy;
272         offset += copy;
273
274         /*
275          * Verify that we can indeed put this data into a skb.
276          * This is here to handle cases when the device erroneously
277          * tries to receive more than is possible. This is usually
278          * the case of a broken device.
279          */
280         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
281                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
282                 dev_kfree_skb(skb);
283                 return NULL;
284         }
285
286         while (len) {
287                 set_skb_frag(skb, page, offset, &len);
288                 page = (struct page *)page->private;
289                 offset = 0;
290         }
291
292         if (page)
293                 give_pages(rq, page);
294
295         return skb;
296 }
297
298 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
299 {
300         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
301         struct page *page;
302         int num_buf, i, len;
303
304         num_buf = hdr->mhdr.num_buffers;
305         while (--num_buf) {
306                 i = skb_shinfo(skb)->nr_frags;
307                 if (i >= MAX_SKB_FRAGS) {
308                         pr_debug("%s: packet too long\n", skb->dev->name);
309                         skb->dev->stats.rx_length_errors++;
310                         return -EINVAL;
311                 }
312                 page = virtqueue_get_buf(rq->vq, &len);
313                 if (!page) {
314                         pr_debug("%s: rx error: %d buffers missing\n",
315                                  skb->dev->name, hdr->mhdr.num_buffers);
316                         skb->dev->stats.rx_length_errors++;
317                         return -EINVAL;
318                 }
319
320                 if (len > PAGE_SIZE)
321                         len = PAGE_SIZE;
322
323                 set_skb_frag(skb, page, 0, &len);
324
325                 --rq->num;
326         }
327         return 0;
328 }
329
330 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
331 {
332         struct virtnet_info *vi = rq->vq->vdev->priv;
333         struct net_device *dev = vi->dev;
334         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
335         struct sk_buff *skb;
336         struct page *page;
337         struct skb_vnet_hdr *hdr;
338
339         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
340                 pr_debug("%s: short packet %i\n", dev->name, len);
341                 dev->stats.rx_length_errors++;
342                 if (vi->mergeable_rx_bufs || vi->big_packets)
343                         give_pages(rq, buf);
344                 else
345                         dev_kfree_skb(buf);
346                 return;
347         }
348
349         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
350                 skb = buf;
351                 len -= sizeof(struct virtio_net_hdr);
352                 skb_trim(skb, len);
353         } else {
354                 page = buf;
355                 skb = page_to_skb(rq, page, len);
356                 if (unlikely(!skb)) {
357                         dev->stats.rx_dropped++;
358                         give_pages(rq, page);
359                         return;
360                 }
361                 if (vi->mergeable_rx_bufs)
362                         if (receive_mergeable(rq, skb)) {
363                                 dev_kfree_skb(skb);
364                                 return;
365                         }
366         }
367
368         hdr = skb_vnet_hdr(skb);
369
370         u64_stats_update_begin(&stats->rx_syncp);
371         stats->rx_bytes += skb->len;
372         stats->rx_packets++;
373         u64_stats_update_end(&stats->rx_syncp);
374
375         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
376                 pr_debug("Needs csum!\n");
377                 if (!skb_partial_csum_set(skb,
378                                           hdr->hdr.csum_start,
379                                           hdr->hdr.csum_offset))
380                         goto frame_err;
381         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
382                 skb->ip_summed = CHECKSUM_UNNECESSARY;
383         }
384
385         skb->protocol = eth_type_trans(skb, dev);
386         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
387                  ntohs(skb->protocol), skb->len, skb->pkt_type);
388
389         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
390                 pr_debug("GSO!\n");
391                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
392                 case VIRTIO_NET_HDR_GSO_TCPV4:
393                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
394                         break;
395                 case VIRTIO_NET_HDR_GSO_UDP:
396                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
397                         break;
398                 case VIRTIO_NET_HDR_GSO_TCPV6:
399                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
400                         break;
401                 default:
402                         net_warn_ratelimited("%s: bad gso type %u.\n",
403                                              dev->name, hdr->hdr.gso_type);
404                         goto frame_err;
405                 }
406
407                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
408                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
409
410                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
411                 if (skb_shinfo(skb)->gso_size == 0) {
412                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
413                         goto frame_err;
414                 }
415
416                 /* Header must be checked, and gso_segs computed. */
417                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
418                 skb_shinfo(skb)->gso_segs = 0;
419         }
420
421         netif_receive_skb(skb);
422         return;
423
424 frame_err:
425         dev->stats.rx_frame_errors++;
426         dev_kfree_skb(skb);
427 }
428
429 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
430 {
431         struct virtnet_info *vi = rq->vq->vdev->priv;
432         struct sk_buff *skb;
433         struct skb_vnet_hdr *hdr;
434         int err;
435
436         skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
437         if (unlikely(!skb))
438                 return -ENOMEM;
439
440         skb_put(skb, MAX_PACKET_LEN);
441
442         hdr = skb_vnet_hdr(skb);
443         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
444
445         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
446
447         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp);
448         if (err < 0)
449                 dev_kfree_skb(skb);
450
451         return err;
452 }
453
454 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
455 {
456         struct page *first, *list = NULL;
457         char *p;
458         int i, err, offset;
459
460         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
461         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
462                 first = get_a_page(rq, gfp);
463                 if (!first) {
464                         if (list)
465                                 give_pages(rq, list);
466                         return -ENOMEM;
467                 }
468                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
469
470                 /* chain new page in list head to match sg */
471                 first->private = (unsigned long)list;
472                 list = first;
473         }
474
475         first = get_a_page(rq, gfp);
476         if (!first) {
477                 give_pages(rq, list);
478                 return -ENOMEM;
479         }
480         p = page_address(first);
481
482         /* rq->sg[0], rq->sg[1] share the same page */
483         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
484         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
485
486         /* rq->sg[1] for data packet, from offset */
487         offset = sizeof(struct padded_vnet_hdr);
488         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
489
490         /* chain first in list head */
491         first->private = (unsigned long)list;
492         err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2,
493                                 first, gfp);
494         if (err < 0)
495                 give_pages(rq, first);
496
497         return err;
498 }
499
500 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
501 {
502         struct page *page;
503         int err;
504
505         page = get_a_page(rq, gfp);
506         if (!page)
507                 return -ENOMEM;
508
509         sg_init_one(rq->sg, page_address(page), PAGE_SIZE);
510
511         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp);
512         if (err < 0)
513                 give_pages(rq, page);
514
515         return err;
516 }
517
518 /*
519  * Returns false if we couldn't fill entirely (OOM).
520  *
521  * Normally run in the receive path, but can also be run from ndo_open
522  * before we're receiving packets, or from refill_work which is
523  * careful to disable receiving (using napi_disable).
524  */
525 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
526 {
527         struct virtnet_info *vi = rq->vq->vdev->priv;
528         int err;
529         bool oom;
530
531         do {
532                 if (vi->mergeable_rx_bufs)
533                         err = add_recvbuf_mergeable(rq, gfp);
534                 else if (vi->big_packets)
535                         err = add_recvbuf_big(rq, gfp);
536                 else
537                         err = add_recvbuf_small(rq, gfp);
538
539                 oom = err == -ENOMEM;
540                 if (err)
541                         break;
542                 ++rq->num;
543         } while (rq->vq->num_free);
544         if (unlikely(rq->num > rq->max))
545                 rq->max = rq->num;
546         virtqueue_kick(rq->vq);
547         return !oom;
548 }
549
550 static void skb_recv_done(struct virtqueue *rvq)
551 {
552         struct virtnet_info *vi = rvq->vdev->priv;
553         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
554
555         /* Schedule NAPI, Suppress further interrupts if successful. */
556         if (napi_schedule_prep(&rq->napi)) {
557                 virtqueue_disable_cb(rvq);
558                 __napi_schedule(&rq->napi);
559         }
560 }
561
562 static void virtnet_napi_enable(struct receive_queue *rq)
563 {
564         napi_enable(&rq->napi);
565
566         /* If all buffers were filled by other side before we napi_enabled, we
567          * won't get another interrupt, so process any outstanding packets
568          * now.  virtnet_poll wants re-enable the queue, so we disable here.
569          * We synchronize against interrupts via NAPI_STATE_SCHED */
570         if (napi_schedule_prep(&rq->napi)) {
571                 virtqueue_disable_cb(rq->vq);
572                 local_bh_disable();
573                 __napi_schedule(&rq->napi);
574                 local_bh_enable();
575         }
576 }
577
578 static void refill_work(struct work_struct *work)
579 {
580         struct virtnet_info *vi =
581                 container_of(work, struct virtnet_info, refill.work);
582         bool still_empty;
583         int i;
584
585         for (i = 0; i < vi->max_queue_pairs; i++) {
586                 struct receive_queue *rq = &vi->rq[i];
587
588                 napi_disable(&rq->napi);
589                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
590                 virtnet_napi_enable(rq);
591
592                 /* In theory, this can happen: if we don't get any buffers in
593                  * we will *never* try to fill again.
594                  */
595                 if (still_empty)
596                         schedule_delayed_work(&vi->refill, HZ/2);
597         }
598 }
599
600 static int virtnet_poll(struct napi_struct *napi, int budget)
601 {
602         struct receive_queue *rq =
603                 container_of(napi, struct receive_queue, napi);
604         struct virtnet_info *vi = rq->vq->vdev->priv;
605         void *buf;
606         unsigned int len, received = 0;
607
608 again:
609         while (received < budget &&
610                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
611                 receive_buf(rq, buf, len);
612                 --rq->num;
613                 received++;
614         }
615
616         if (rq->num < rq->max / 2) {
617                 if (!try_fill_recv(rq, GFP_ATOMIC))
618                         schedule_delayed_work(&vi->refill, 0);
619         }
620
621         /* Out of packets? */
622         if (received < budget) {
623                 napi_complete(napi);
624                 if (unlikely(!virtqueue_enable_cb(rq->vq)) &&
625                     napi_schedule_prep(napi)) {
626                         virtqueue_disable_cb(rq->vq);
627                         __napi_schedule(napi);
628                         goto again;
629                 }
630         }
631
632         return received;
633 }
634
635 static int virtnet_open(struct net_device *dev)
636 {
637         struct virtnet_info *vi = netdev_priv(dev);
638         int i;
639
640         for (i = 0; i < vi->max_queue_pairs; i++) {
641                 /* Make sure we have some buffers: if oom use wq. */
642                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
643                         schedule_delayed_work(&vi->refill, 0);
644                 virtnet_napi_enable(&vi->rq[i]);
645         }
646
647         return 0;
648 }
649
650 static void free_old_xmit_skbs(struct send_queue *sq)
651 {
652         struct sk_buff *skb;
653         unsigned int len;
654         struct virtnet_info *vi = sq->vq->vdev->priv;
655         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
656
657         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
658                 pr_debug("Sent skb %p\n", skb);
659
660                 u64_stats_update_begin(&stats->tx_syncp);
661                 stats->tx_bytes += skb->len;
662                 stats->tx_packets++;
663                 u64_stats_update_end(&stats->tx_syncp);
664
665                 dev_kfree_skb_any(skb);
666         }
667 }
668
669 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
670 {
671         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
672         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
673         struct virtnet_info *vi = sq->vq->vdev->priv;
674         unsigned num_sg;
675
676         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
677
678         if (skb->ip_summed == CHECKSUM_PARTIAL) {
679                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
680                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
681                 hdr->hdr.csum_offset = skb->csum_offset;
682         } else {
683                 hdr->hdr.flags = 0;
684                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
685         }
686
687         if (skb_is_gso(skb)) {
688                 hdr->hdr.hdr_len = skb_headlen(skb);
689                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
690                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
691                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
692                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
693                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
694                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
695                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
696                 else
697                         BUG();
698                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
699                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
700         } else {
701                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
702                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
703         }
704
705         hdr->mhdr.num_buffers = 0;
706
707         /* Encode metadata header at front. */
708         if (vi->mergeable_rx_bufs)
709                 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
710         else
711                 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
712
713         num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
714         return virtqueue_add_buf(sq->vq, sq->sg, num_sg,
715                                  0, skb, GFP_ATOMIC);
716 }
717
718 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
719 {
720         struct virtnet_info *vi = netdev_priv(dev);
721         int qnum = skb_get_queue_mapping(skb);
722         struct send_queue *sq = &vi->sq[qnum];
723         int err;
724
725         /* Free up any pending old buffers before queueing new ones. */
726         free_old_xmit_skbs(sq);
727
728         /* Try to transmit */
729         err = xmit_skb(sq, skb);
730
731         /* This should not happen! */
732         if (unlikely(err)) {
733                 dev->stats.tx_fifo_errors++;
734                 if (net_ratelimit())
735                         dev_warn(&dev->dev,
736                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
737                 dev->stats.tx_dropped++;
738                 kfree_skb(skb);
739                 return NETDEV_TX_OK;
740         }
741         virtqueue_kick(sq->vq);
742
743         /* Don't wait up for transmitted skbs to be freed. */
744         skb_orphan(skb);
745         nf_reset(skb);
746
747         /* Apparently nice girls don't return TX_BUSY; stop the queue
748          * before it gets out of hand.  Naturally, this wastes entries. */
749         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
750                 netif_stop_subqueue(dev, qnum);
751                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
752                         /* More just got used, free them then recheck. */
753                         free_old_xmit_skbs(sq);
754                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
755                                 netif_start_subqueue(dev, qnum);
756                                 virtqueue_disable_cb(sq->vq);
757                         }
758                 }
759         }
760
761         return NETDEV_TX_OK;
762 }
763
764 /*
765  * Send command via the control virtqueue and check status.  Commands
766  * supported by the hypervisor, as indicated by feature bits, should
767  * never fail unless improperly formated.
768  */
769 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
770                                  struct scatterlist *data, int out, int in)
771 {
772         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
773         struct virtio_net_ctrl_hdr ctrl;
774         virtio_net_ctrl_ack status = ~0;
775         unsigned int tmp;
776         int i;
777
778         /* Caller should know better */
779         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
780                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
781
782         out++; /* Add header */
783         in++; /* Add return status */
784
785         ctrl.class = class;
786         ctrl.cmd = cmd;
787
788         sg_init_table(sg, out + in);
789
790         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
791         for_each_sg(data, s, out + in - 2, i)
792                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
793         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
794
795         BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
796
797         virtqueue_kick(vi->cvq);
798
799         /* Spin for a response, the kick causes an ioport write, trapping
800          * into the hypervisor, so the request should be handled immediately.
801          */
802         while (!virtqueue_get_buf(vi->cvq, &tmp))
803                 cpu_relax();
804
805         return status == VIRTIO_NET_OK;
806 }
807
808 static int virtnet_set_mac_address(struct net_device *dev, void *p)
809 {
810         struct virtnet_info *vi = netdev_priv(dev);
811         struct virtio_device *vdev = vi->vdev;
812         int ret;
813         struct sockaddr *addr = p;
814         struct scatterlist sg;
815
816         ret = eth_prepare_mac_addr_change(dev, p);
817         if (ret)
818                 return ret;
819
820         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
821                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
822                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
823                                           VIRTIO_NET_CTRL_MAC_ADDR_SET,
824                                           &sg, 1, 0)) {
825                         dev_warn(&vdev->dev,
826                                  "Failed to set mac address by vq command.\n");
827                         return -EINVAL;
828                 }
829         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
830                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
831                                   addr->sa_data, dev->addr_len);
832         }
833
834         eth_commit_mac_addr_change(dev, p);
835
836         return 0;
837 }
838
839 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
840                                                struct rtnl_link_stats64 *tot)
841 {
842         struct virtnet_info *vi = netdev_priv(dev);
843         int cpu;
844         unsigned int start;
845
846         for_each_possible_cpu(cpu) {
847                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
848                 u64 tpackets, tbytes, rpackets, rbytes;
849
850                 do {
851                         start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
852                         tpackets = stats->tx_packets;
853                         tbytes   = stats->tx_bytes;
854                 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
855
856                 do {
857                         start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
858                         rpackets = stats->rx_packets;
859                         rbytes   = stats->rx_bytes;
860                 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
861
862                 tot->rx_packets += rpackets;
863                 tot->tx_packets += tpackets;
864                 tot->rx_bytes   += rbytes;
865                 tot->tx_bytes   += tbytes;
866         }
867
868         tot->tx_dropped = dev->stats.tx_dropped;
869         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
870         tot->rx_dropped = dev->stats.rx_dropped;
871         tot->rx_length_errors = dev->stats.rx_length_errors;
872         tot->rx_frame_errors = dev->stats.rx_frame_errors;
873
874         return tot;
875 }
876
877 #ifdef CONFIG_NET_POLL_CONTROLLER
878 static void virtnet_netpoll(struct net_device *dev)
879 {
880         struct virtnet_info *vi = netdev_priv(dev);
881         int i;
882
883         for (i = 0; i < vi->curr_queue_pairs; i++)
884                 napi_schedule(&vi->rq[i].napi);
885 }
886 #endif
887
888 static void virtnet_ack_link_announce(struct virtnet_info *vi)
889 {
890         rtnl_lock();
891         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
892                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
893                                   0, 0))
894                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
895         rtnl_unlock();
896 }
897
898 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
899 {
900         struct scatterlist sg;
901         struct virtio_net_ctrl_mq s;
902         struct net_device *dev = vi->dev;
903
904         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
905                 return 0;
906
907         s.virtqueue_pairs = queue_pairs;
908         sg_init_one(&sg, &s, sizeof(s));
909
910         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
911                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){
912                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
913                          queue_pairs);
914                 return -EINVAL;
915         } else
916                 vi->curr_queue_pairs = queue_pairs;
917
918         return 0;
919 }
920
921 static int virtnet_close(struct net_device *dev)
922 {
923         struct virtnet_info *vi = netdev_priv(dev);
924         int i;
925
926         /* Make sure refill_work doesn't re-enable napi! */
927         cancel_delayed_work_sync(&vi->refill);
928
929         for (i = 0; i < vi->max_queue_pairs; i++)
930                 napi_disable(&vi->rq[i].napi);
931
932         return 0;
933 }
934
935 static void virtnet_set_rx_mode(struct net_device *dev)
936 {
937         struct virtnet_info *vi = netdev_priv(dev);
938         struct scatterlist sg[2];
939         u8 promisc, allmulti;
940         struct virtio_net_ctrl_mac *mac_data;
941         struct netdev_hw_addr *ha;
942         int uc_count;
943         int mc_count;
944         void *buf;
945         int i;
946
947         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
948         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
949                 return;
950
951         promisc = ((dev->flags & IFF_PROMISC) != 0);
952         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
953
954         sg_init_one(sg, &promisc, sizeof(promisc));
955
956         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
957                                   VIRTIO_NET_CTRL_RX_PROMISC,
958                                   sg, 1, 0))
959                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
960                          promisc ? "en" : "dis");
961
962         sg_init_one(sg, &allmulti, sizeof(allmulti));
963
964         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
965                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
966                                   sg, 1, 0))
967                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
968                          allmulti ? "en" : "dis");
969
970         uc_count = netdev_uc_count(dev);
971         mc_count = netdev_mc_count(dev);
972         /* MAC filter - use one buffer for both lists */
973         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
974                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
975         mac_data = buf;
976         if (!buf)
977                 return;
978
979         sg_init_table(sg, 2);
980
981         /* Store the unicast list and count in the front of the buffer */
982         mac_data->entries = uc_count;
983         i = 0;
984         netdev_for_each_uc_addr(ha, dev)
985                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
986
987         sg_set_buf(&sg[0], mac_data,
988                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
989
990         /* multicast list and count fill the end */
991         mac_data = (void *)&mac_data->macs[uc_count][0];
992
993         mac_data->entries = mc_count;
994         i = 0;
995         netdev_for_each_mc_addr(ha, dev)
996                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
997
998         sg_set_buf(&sg[1], mac_data,
999                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1000
1001         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1002                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
1003                                   sg, 2, 0))
1004                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
1005
1006         kfree(buf);
1007 }
1008
1009 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
1010 {
1011         struct virtnet_info *vi = netdev_priv(dev);
1012         struct scatterlist sg;
1013
1014         sg_init_one(&sg, &vid, sizeof(vid));
1015
1016         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1017                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
1018                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1019         return 0;
1020 }
1021
1022 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
1023 {
1024         struct virtnet_info *vi = netdev_priv(dev);
1025         struct scatterlist sg;
1026
1027         sg_init_one(&sg, &vid, sizeof(vid));
1028
1029         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1030                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
1031                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1032         return 0;
1033 }
1034
1035 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1036 {
1037         int i;
1038         int cpu;
1039
1040         if (vi->affinity_hint_set) {
1041                 for (i = 0; i < vi->max_queue_pairs; i++) {
1042                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1043                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1044                 }
1045
1046                 vi->affinity_hint_set = false;
1047         }
1048
1049         i = 0;
1050         for_each_online_cpu(cpu) {
1051                 if (cpu == hcpu) {
1052                         *per_cpu_ptr(vi->vq_index, cpu) = -1;
1053                 } else {
1054                         *per_cpu_ptr(vi->vq_index, cpu) =
1055                                 ++i % vi->curr_queue_pairs;
1056                 }
1057         }
1058 }
1059
1060 static void virtnet_set_affinity(struct virtnet_info *vi)
1061 {
1062         int i;
1063         int cpu;
1064
1065         /* In multiqueue mode, when the number of cpu is equal to the number of
1066          * queue pairs, we let the queue pairs to be private to one cpu by
1067          * setting the affinity hint to eliminate the contention.
1068          */
1069         if (vi->curr_queue_pairs == 1 ||
1070             vi->max_queue_pairs != num_online_cpus()) {
1071                 virtnet_clean_affinity(vi, -1);
1072                 return;
1073         }
1074
1075         i = 0;
1076         for_each_online_cpu(cpu) {
1077                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1078                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1079                 *per_cpu_ptr(vi->vq_index, cpu) = i;
1080                 i++;
1081         }
1082
1083         vi->affinity_hint_set = true;
1084 }
1085
1086 static int virtnet_cpu_callback(struct notifier_block *nfb,
1087                                 unsigned long action, void *hcpu)
1088 {
1089         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1090
1091         switch(action & ~CPU_TASKS_FROZEN) {
1092         case CPU_ONLINE:
1093         case CPU_DOWN_FAILED:
1094         case CPU_DEAD:
1095                 virtnet_set_affinity(vi);
1096                 break;
1097         case CPU_DOWN_PREPARE:
1098                 virtnet_clean_affinity(vi, (long)hcpu);
1099                 break;
1100         default:
1101                 break;
1102         }
1103         return NOTIFY_OK;
1104 }
1105
1106 static void virtnet_get_ringparam(struct net_device *dev,
1107                                 struct ethtool_ringparam *ring)
1108 {
1109         struct virtnet_info *vi = netdev_priv(dev);
1110
1111         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1112         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1113         ring->rx_pending = ring->rx_max_pending;
1114         ring->tx_pending = ring->tx_max_pending;
1115 }
1116
1117
1118 static void virtnet_get_drvinfo(struct net_device *dev,
1119                                 struct ethtool_drvinfo *info)
1120 {
1121         struct virtnet_info *vi = netdev_priv(dev);
1122         struct virtio_device *vdev = vi->vdev;
1123
1124         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1125         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1126         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1127
1128 }
1129
1130 /* TODO: Eliminate OOO packets during switching */
1131 static int virtnet_set_channels(struct net_device *dev,
1132                                 struct ethtool_channels *channels)
1133 {
1134         struct virtnet_info *vi = netdev_priv(dev);
1135         u16 queue_pairs = channels->combined_count;
1136         int err;
1137
1138         /* We don't support separate rx/tx channels.
1139          * We don't allow setting 'other' channels.
1140          */
1141         if (channels->rx_count || channels->tx_count || channels->other_count)
1142                 return -EINVAL;
1143
1144         if (queue_pairs > vi->max_queue_pairs)
1145                 return -EINVAL;
1146
1147         get_online_cpus();
1148         err = virtnet_set_queues(vi, queue_pairs);
1149         if (!err) {
1150                 netif_set_real_num_tx_queues(dev, queue_pairs);
1151                 netif_set_real_num_rx_queues(dev, queue_pairs);
1152
1153                 virtnet_set_affinity(vi);
1154         }
1155         put_online_cpus();
1156
1157         return err;
1158 }
1159
1160 static void virtnet_get_channels(struct net_device *dev,
1161                                  struct ethtool_channels *channels)
1162 {
1163         struct virtnet_info *vi = netdev_priv(dev);
1164
1165         channels->combined_count = vi->curr_queue_pairs;
1166         channels->max_combined = vi->max_queue_pairs;
1167         channels->max_other = 0;
1168         channels->rx_count = 0;
1169         channels->tx_count = 0;
1170         channels->other_count = 0;
1171 }
1172
1173 static const struct ethtool_ops virtnet_ethtool_ops = {
1174         .get_drvinfo = virtnet_get_drvinfo,
1175         .get_link = ethtool_op_get_link,
1176         .get_ringparam = virtnet_get_ringparam,
1177         .set_channels = virtnet_set_channels,
1178         .get_channels = virtnet_get_channels,
1179 };
1180
1181 #define MIN_MTU 68
1182 #define MAX_MTU 65535
1183
1184 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1185 {
1186         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1187                 return -EINVAL;
1188         dev->mtu = new_mtu;
1189         return 0;
1190 }
1191
1192 /* To avoid contending a lock hold by a vcpu who would exit to host, select the
1193  * txq based on the processor id.
1194  */
1195 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
1196 {
1197         int txq;
1198         struct virtnet_info *vi = netdev_priv(dev);
1199
1200         if (skb_rx_queue_recorded(skb)) {
1201                 txq = skb_get_rx_queue(skb);
1202         } else {
1203                 txq = *__this_cpu_ptr(vi->vq_index);
1204                 if (txq == -1)
1205                         txq = 0;
1206         }
1207
1208         while (unlikely(txq >= dev->real_num_tx_queues))
1209                 txq -= dev->real_num_tx_queues;
1210
1211         return txq;
1212 }
1213
1214 static const struct net_device_ops virtnet_netdev = {
1215         .ndo_open            = virtnet_open,
1216         .ndo_stop            = virtnet_close,
1217         .ndo_start_xmit      = start_xmit,
1218         .ndo_validate_addr   = eth_validate_addr,
1219         .ndo_set_mac_address = virtnet_set_mac_address,
1220         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1221         .ndo_change_mtu      = virtnet_change_mtu,
1222         .ndo_get_stats64     = virtnet_stats,
1223         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1224         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1225         .ndo_select_queue     = virtnet_select_queue,
1226 #ifdef CONFIG_NET_POLL_CONTROLLER
1227         .ndo_poll_controller = virtnet_netpoll,
1228 #endif
1229 };
1230
1231 static void virtnet_config_changed_work(struct work_struct *work)
1232 {
1233         struct virtnet_info *vi =
1234                 container_of(work, struct virtnet_info, config_work);
1235         u16 v;
1236
1237         mutex_lock(&vi->config_lock);
1238         if (!vi->config_enable)
1239                 goto done;
1240
1241         if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
1242                               offsetof(struct virtio_net_config, status),
1243                               &v) < 0)
1244                 goto done;
1245
1246         if (v & VIRTIO_NET_S_ANNOUNCE) {
1247                 netdev_notify_peers(vi->dev);
1248                 virtnet_ack_link_announce(vi);
1249         }
1250
1251         /* Ignore unknown (future) status bits */
1252         v &= VIRTIO_NET_S_LINK_UP;
1253
1254         if (vi->status == v)
1255                 goto done;
1256
1257         vi->status = v;
1258
1259         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1260                 netif_carrier_on(vi->dev);
1261                 netif_tx_wake_all_queues(vi->dev);
1262         } else {
1263                 netif_carrier_off(vi->dev);
1264                 netif_tx_stop_all_queues(vi->dev);
1265         }
1266 done:
1267         mutex_unlock(&vi->config_lock);
1268 }
1269
1270 static void virtnet_config_changed(struct virtio_device *vdev)
1271 {
1272         struct virtnet_info *vi = vdev->priv;
1273
1274         schedule_work(&vi->config_work);
1275 }
1276
1277 static void virtnet_free_queues(struct virtnet_info *vi)
1278 {
1279         kfree(vi->rq);
1280         kfree(vi->sq);
1281 }
1282
1283 static void free_receive_bufs(struct virtnet_info *vi)
1284 {
1285         int i;
1286
1287         for (i = 0; i < vi->max_queue_pairs; i++) {
1288                 while (vi->rq[i].pages)
1289                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1290         }
1291 }
1292
1293 static void free_unused_bufs(struct virtnet_info *vi)
1294 {
1295         void *buf;
1296         int i;
1297
1298         for (i = 0; i < vi->max_queue_pairs; i++) {
1299                 struct virtqueue *vq = vi->sq[i].vq;
1300                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1301                         dev_kfree_skb(buf);
1302         }
1303
1304         for (i = 0; i < vi->max_queue_pairs; i++) {
1305                 struct virtqueue *vq = vi->rq[i].vq;
1306
1307                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1308                         if (vi->mergeable_rx_bufs || vi->big_packets)
1309                                 give_pages(&vi->rq[i], buf);
1310                         else
1311                                 dev_kfree_skb(buf);
1312                         --vi->rq[i].num;
1313                 }
1314                 BUG_ON(vi->rq[i].num != 0);
1315         }
1316 }
1317
1318 static void virtnet_del_vqs(struct virtnet_info *vi)
1319 {
1320         struct virtio_device *vdev = vi->vdev;
1321
1322         virtnet_clean_affinity(vi, -1);
1323
1324         vdev->config->del_vqs(vdev);
1325
1326         virtnet_free_queues(vi);
1327 }
1328
1329 static int virtnet_find_vqs(struct virtnet_info *vi)
1330 {
1331         vq_callback_t **callbacks;
1332         struct virtqueue **vqs;
1333         int ret = -ENOMEM;
1334         int i, total_vqs;
1335         const char **names;
1336
1337         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1338          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1339          * possible control vq.
1340          */
1341         total_vqs = vi->max_queue_pairs * 2 +
1342                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1343
1344         /* Allocate space for find_vqs parameters */
1345         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1346         if (!vqs)
1347                 goto err_vq;
1348         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1349         if (!callbacks)
1350                 goto err_callback;
1351         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1352         if (!names)
1353                 goto err_names;
1354
1355         /* Parameters for control virtqueue, if any */
1356         if (vi->has_cvq) {
1357                 callbacks[total_vqs - 1] = NULL;
1358                 names[total_vqs - 1] = "control";
1359         }
1360
1361         /* Allocate/initialize parameters for send/receive virtqueues */
1362         for (i = 0; i < vi->max_queue_pairs; i++) {
1363                 callbacks[rxq2vq(i)] = skb_recv_done;
1364                 callbacks[txq2vq(i)] = skb_xmit_done;
1365                 sprintf(vi->rq[i].name, "input.%d", i);
1366                 sprintf(vi->sq[i].name, "output.%d", i);
1367                 names[rxq2vq(i)] = vi->rq[i].name;
1368                 names[txq2vq(i)] = vi->sq[i].name;
1369         }
1370
1371         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1372                                          names);
1373         if (ret)
1374                 goto err_find;
1375
1376         if (vi->has_cvq) {
1377                 vi->cvq = vqs[total_vqs - 1];
1378                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1379                         vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1380         }
1381
1382         for (i = 0; i < vi->max_queue_pairs; i++) {
1383                 vi->rq[i].vq = vqs[rxq2vq(i)];
1384                 vi->sq[i].vq = vqs[txq2vq(i)];
1385         }
1386
1387         kfree(names);
1388         kfree(callbacks);
1389         kfree(vqs);
1390
1391         return 0;
1392
1393 err_find:
1394         kfree(names);
1395 err_names:
1396         kfree(callbacks);
1397 err_callback:
1398         kfree(vqs);
1399 err_vq:
1400         return ret;
1401 }
1402
1403 static int virtnet_alloc_queues(struct virtnet_info *vi)
1404 {
1405         int i;
1406
1407         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1408         if (!vi->sq)
1409                 goto err_sq;
1410         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1411         if (!vi->rq)
1412                 goto err_rq;
1413
1414         INIT_DELAYED_WORK(&vi->refill, refill_work);
1415         for (i = 0; i < vi->max_queue_pairs; i++) {
1416                 vi->rq[i].pages = NULL;
1417                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1418                                napi_weight);
1419
1420                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1421                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1422         }
1423
1424         return 0;
1425
1426 err_rq:
1427         kfree(vi->sq);
1428 err_sq:
1429         return -ENOMEM;
1430 }
1431
1432 static int init_vqs(struct virtnet_info *vi)
1433 {
1434         int ret;
1435
1436         /* Allocate send & receive queues */
1437         ret = virtnet_alloc_queues(vi);
1438         if (ret)
1439                 goto err;
1440
1441         ret = virtnet_find_vqs(vi);
1442         if (ret)
1443                 goto err_free;
1444
1445         get_online_cpus();
1446         virtnet_set_affinity(vi);
1447         put_online_cpus();
1448
1449         return 0;
1450
1451 err_free:
1452         virtnet_free_queues(vi);
1453 err:
1454         return ret;
1455 }
1456
1457 static int virtnet_probe(struct virtio_device *vdev)
1458 {
1459         int i, err;
1460         struct net_device *dev;
1461         struct virtnet_info *vi;
1462         u16 max_queue_pairs;
1463
1464         /* Find if host supports multiqueue virtio_net device */
1465         err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
1466                                 offsetof(struct virtio_net_config,
1467                                 max_virtqueue_pairs), &max_queue_pairs);
1468
1469         /* We need at least 2 queue's */
1470         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1471             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1472             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1473                 max_queue_pairs = 1;
1474
1475         /* Allocate ourselves a network device with room for our info */
1476         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1477         if (!dev)
1478                 return -ENOMEM;
1479
1480         /* Set up network device as normal. */
1481         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1482         dev->netdev_ops = &virtnet_netdev;
1483         dev->features = NETIF_F_HIGHDMA;
1484
1485         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1486         SET_NETDEV_DEV(dev, &vdev->dev);
1487
1488         /* Do we support "hardware" checksums? */
1489         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1490                 /* This opens up the world of extra features. */
1491                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1492                 if (csum)
1493                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1494
1495                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1496                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1497                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1498                 }
1499                 /* Individual feature bits: what can host handle? */
1500                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1501                         dev->hw_features |= NETIF_F_TSO;
1502                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1503                         dev->hw_features |= NETIF_F_TSO6;
1504                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1505                         dev->hw_features |= NETIF_F_TSO_ECN;
1506                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1507                         dev->hw_features |= NETIF_F_UFO;
1508
1509                 if (gso)
1510                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1511                 /* (!csum && gso) case will be fixed by register_netdev() */
1512         }
1513
1514         /* Configuration may specify what MAC to use.  Otherwise random. */
1515         if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1516                                   offsetof(struct virtio_net_config, mac),
1517                                   dev->dev_addr, dev->addr_len) < 0)
1518                 eth_hw_addr_random(dev);
1519
1520         /* Set up our device-specific information */
1521         vi = netdev_priv(dev);
1522         vi->dev = dev;
1523         vi->vdev = vdev;
1524         vdev->priv = vi;
1525         vi->stats = alloc_percpu(struct virtnet_stats);
1526         err = -ENOMEM;
1527         if (vi->stats == NULL)
1528                 goto free;
1529
1530         vi->vq_index = alloc_percpu(int);
1531         if (vi->vq_index == NULL)
1532                 goto free_stats;
1533
1534         mutex_init(&vi->config_lock);
1535         vi->config_enable = true;
1536         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1537
1538         /* If we can receive ANY GSO packets, we must allocate large ones. */
1539         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1540             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1541             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1542                 vi->big_packets = true;
1543
1544         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1545                 vi->mergeable_rx_bufs = true;
1546
1547         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1548                 vi->has_cvq = true;
1549
1550         /* Use single tx/rx queue pair as default */
1551         vi->curr_queue_pairs = 1;
1552         vi->max_queue_pairs = max_queue_pairs;
1553
1554         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1555         err = init_vqs(vi);
1556         if (err)
1557                 goto free_index;
1558
1559         netif_set_real_num_tx_queues(dev, 1);
1560         netif_set_real_num_rx_queues(dev, 1);
1561
1562         err = register_netdev(dev);
1563         if (err) {
1564                 pr_debug("virtio_net: registering device failed\n");
1565                 goto free_vqs;
1566         }
1567
1568         /* Last of all, set up some receive buffers. */
1569         for (i = 0; i < vi->max_queue_pairs; i++) {
1570                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1571
1572                 /* If we didn't even get one input buffer, we're useless. */
1573                 if (vi->rq[i].num == 0) {
1574                         free_unused_bufs(vi);
1575                         err = -ENOMEM;
1576                         goto free_recv_bufs;
1577                 }
1578         }
1579
1580         vi->nb.notifier_call = &virtnet_cpu_callback;
1581         err = register_hotcpu_notifier(&vi->nb);
1582         if (err) {
1583                 pr_debug("virtio_net: registering cpu notifier failed\n");
1584                 goto free_recv_bufs;
1585         }
1586
1587         /* Assume link up if device can't report link status,
1588            otherwise get link status from config. */
1589         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1590                 netif_carrier_off(dev);
1591                 schedule_work(&vi->config_work);
1592         } else {
1593                 vi->status = VIRTIO_NET_S_LINK_UP;
1594                 netif_carrier_on(dev);
1595         }
1596
1597         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1598                  dev->name, max_queue_pairs);
1599
1600         return 0;
1601
1602 free_recv_bufs:
1603         free_receive_bufs(vi);
1604         unregister_netdev(dev);
1605 free_vqs:
1606         cancel_delayed_work_sync(&vi->refill);
1607         virtnet_del_vqs(vi);
1608 free_index:
1609         free_percpu(vi->vq_index);
1610 free_stats:
1611         free_percpu(vi->stats);
1612 free:
1613         free_netdev(dev);
1614         return err;
1615 }
1616
1617 static void remove_vq_common(struct virtnet_info *vi)
1618 {
1619         vi->vdev->config->reset(vi->vdev);
1620
1621         /* Free unused buffers in both send and recv, if any. */
1622         free_unused_bufs(vi);
1623
1624         free_receive_bufs(vi);
1625
1626         virtnet_del_vqs(vi);
1627 }
1628
1629 static void virtnet_remove(struct virtio_device *vdev)
1630 {
1631         struct virtnet_info *vi = vdev->priv;
1632
1633         unregister_hotcpu_notifier(&vi->nb);
1634
1635         /* Prevent config work handler from accessing the device. */
1636         mutex_lock(&vi->config_lock);
1637         vi->config_enable = false;
1638         mutex_unlock(&vi->config_lock);
1639
1640         unregister_netdev(vi->dev);
1641
1642         remove_vq_common(vi);
1643
1644         flush_work(&vi->config_work);
1645
1646         free_percpu(vi->vq_index);
1647         free_percpu(vi->stats);
1648         free_netdev(vi->dev);
1649 }
1650
1651 #ifdef CONFIG_PM
1652 static int virtnet_freeze(struct virtio_device *vdev)
1653 {
1654         struct virtnet_info *vi = vdev->priv;
1655         int i;
1656
1657         /* Prevent config work handler from accessing the device */
1658         mutex_lock(&vi->config_lock);
1659         vi->config_enable = false;
1660         mutex_unlock(&vi->config_lock);
1661
1662         netif_device_detach(vi->dev);
1663         cancel_delayed_work_sync(&vi->refill);
1664
1665         if (netif_running(vi->dev))
1666                 for (i = 0; i < vi->max_queue_pairs; i++) {
1667                         napi_disable(&vi->rq[i].napi);
1668                         netif_napi_del(&vi->rq[i].napi);
1669                 }
1670
1671         remove_vq_common(vi);
1672
1673         flush_work(&vi->config_work);
1674
1675         return 0;
1676 }
1677
1678 static int virtnet_restore(struct virtio_device *vdev)
1679 {
1680         struct virtnet_info *vi = vdev->priv;
1681         int err, i;
1682
1683         err = init_vqs(vi);
1684         if (err)
1685                 return err;
1686
1687         if (netif_running(vi->dev))
1688                 for (i = 0; i < vi->max_queue_pairs; i++)
1689                         virtnet_napi_enable(&vi->rq[i]);
1690
1691         netif_device_attach(vi->dev);
1692
1693         for (i = 0; i < vi->max_queue_pairs; i++)
1694                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1695                         schedule_delayed_work(&vi->refill, 0);
1696
1697         mutex_lock(&vi->config_lock);
1698         vi->config_enable = true;
1699         mutex_unlock(&vi->config_lock);
1700
1701         virtnet_set_queues(vi, vi->curr_queue_pairs);
1702
1703         return 0;
1704 }
1705 #endif
1706
1707 static struct virtio_device_id id_table[] = {
1708         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1709         { 0 },
1710 };
1711
1712 static unsigned int features[] = {
1713         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1714         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1715         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1716         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1717         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1718         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1719         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1720         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1721         VIRTIO_NET_F_CTRL_MAC_ADDR,
1722 };
1723
1724 static struct virtio_driver virtio_net_driver = {
1725         .feature_table = features,
1726         .feature_table_size = ARRAY_SIZE(features),
1727         .driver.name =  KBUILD_MODNAME,
1728         .driver.owner = THIS_MODULE,
1729         .id_table =     id_table,
1730         .probe =        virtnet_probe,
1731         .remove =       virtnet_remove,
1732         .config_changed = virtnet_config_changed,
1733 #ifdef CONFIG_PM
1734         .freeze =       virtnet_freeze,
1735         .restore =      virtnet_restore,
1736 #endif
1737 };
1738
1739 module_virtio_driver(virtio_net_driver);
1740
1741 MODULE_DEVICE_TABLE(virtio, id_table);
1742 MODULE_DESCRIPTION("Virtio network driver");
1743 MODULE_LICENSE("GPL");