2f6fe9b6b17bba4f981e3ba6a03f519d7e9ab14e
[~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
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         /* Per-cpu variable to show the mapping from CPU to virtqueue */
128         int __percpu *vq_index;
129 };
130
131 struct skb_vnet_hdr {
132         union {
133                 struct virtio_net_hdr hdr;
134                 struct virtio_net_hdr_mrg_rxbuf mhdr;
135         };
136 };
137
138 struct padded_vnet_hdr {
139         struct virtio_net_hdr hdr;
140         /*
141          * virtio_net_hdr should be in a separated sg buffer because of a
142          * QEMU bug, and data sg buffer shares same page with this header sg.
143          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
144          */
145         char padding[6];
146 };
147
148 /* Converting between virtqueue no. and kernel tx/rx queue no.
149  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
150  */
151 static int vq2txq(struct virtqueue *vq)
152 {
153         return (virtqueue_get_queue_index(vq) - 1) / 2;
154 }
155
156 static int txq2vq(int txq)
157 {
158         return txq * 2 + 1;
159 }
160
161 static int vq2rxq(struct virtqueue *vq)
162 {
163         return virtqueue_get_queue_index(vq) / 2;
164 }
165
166 static int rxq2vq(int rxq)
167 {
168         return rxq * 2;
169 }
170
171 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
172 {
173         return (struct skb_vnet_hdr *)skb->cb;
174 }
175
176 /*
177  * private is used to chain pages for big packets, put the whole
178  * most recent used list in the beginning for reuse
179  */
180 static void give_pages(struct receive_queue *rq, struct page *page)
181 {
182         struct page *end;
183
184         /* Find end of list, sew whole thing into vi->rq.pages. */
185         for (end = page; end->private; end = (struct page *)end->private);
186         end->private = (unsigned long)rq->pages;
187         rq->pages = page;
188 }
189
190 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
191 {
192         struct page *p = rq->pages;
193
194         if (p) {
195                 rq->pages = (struct page *)p->private;
196                 /* clear private here, it is used to chain pages */
197                 p->private = 0;
198         } else
199                 p = alloc_page(gfp_mask);
200         return p;
201 }
202
203 static void skb_xmit_done(struct virtqueue *vq)
204 {
205         struct virtnet_info *vi = vq->vdev->priv;
206
207         /* Suppress further interrupts. */
208         virtqueue_disable_cb(vq);
209
210         /* We were probably waiting for more output buffers. */
211         netif_wake_subqueue(vi->dev, vq2txq(vq));
212 }
213
214 static void set_skb_frag(struct sk_buff *skb, struct page *page,
215                          unsigned int offset, unsigned int *len)
216 {
217         int size = min((unsigned)PAGE_SIZE - offset, *len);
218         int i = skb_shinfo(skb)->nr_frags;
219
220         __skb_fill_page_desc(skb, i, page, offset, size);
221
222         skb->data_len += size;
223         skb->len += size;
224         skb->truesize += PAGE_SIZE;
225         skb_shinfo(skb)->nr_frags++;
226         *len -= size;
227 }
228
229 /* Called from bottom half context */
230 static struct sk_buff *page_to_skb(struct receive_queue *rq,
231                                    struct page *page, unsigned int len)
232 {
233         struct virtnet_info *vi = rq->vq->vdev->priv;
234         struct sk_buff *skb;
235         struct skb_vnet_hdr *hdr;
236         unsigned int copy, hdr_len, offset;
237         char *p;
238
239         p = page_address(page);
240
241         /* copy small packet so we can reuse these pages for small data */
242         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
243         if (unlikely(!skb))
244                 return NULL;
245
246         hdr = skb_vnet_hdr(skb);
247
248         if (vi->mergeable_rx_bufs) {
249                 hdr_len = sizeof hdr->mhdr;
250                 offset = hdr_len;
251         } else {
252                 hdr_len = sizeof hdr->hdr;
253                 offset = sizeof(struct padded_vnet_hdr);
254         }
255
256         memcpy(hdr, p, hdr_len);
257
258         len -= hdr_len;
259         p += offset;
260
261         copy = len;
262         if (copy > skb_tailroom(skb))
263                 copy = skb_tailroom(skb);
264         memcpy(skb_put(skb, copy), p, copy);
265
266         len -= copy;
267         offset += copy;
268
269         /*
270          * Verify that we can indeed put this data into a skb.
271          * This is here to handle cases when the device erroneously
272          * tries to receive more than is possible. This is usually
273          * the case of a broken device.
274          */
275         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
276                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
277                 dev_kfree_skb(skb);
278                 return NULL;
279         }
280
281         while (len) {
282                 set_skb_frag(skb, page, offset, &len);
283                 page = (struct page *)page->private;
284                 offset = 0;
285         }
286
287         if (page)
288                 give_pages(rq, page);
289
290         return skb;
291 }
292
293 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
294 {
295         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
296         struct page *page;
297         int num_buf, i, len;
298
299         num_buf = hdr->mhdr.num_buffers;
300         while (--num_buf) {
301                 i = skb_shinfo(skb)->nr_frags;
302                 if (i >= MAX_SKB_FRAGS) {
303                         pr_debug("%s: packet too long\n", skb->dev->name);
304                         skb->dev->stats.rx_length_errors++;
305                         return -EINVAL;
306                 }
307                 page = virtqueue_get_buf(rq->vq, &len);
308                 if (!page) {
309                         pr_debug("%s: rx error: %d buffers missing\n",
310                                  skb->dev->name, hdr->mhdr.num_buffers);
311                         skb->dev->stats.rx_length_errors++;
312                         return -EINVAL;
313                 }
314
315                 if (len > PAGE_SIZE)
316                         len = PAGE_SIZE;
317
318                 set_skb_frag(skb, page, 0, &len);
319
320                 --rq->num;
321         }
322         return 0;
323 }
324
325 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
326 {
327         struct virtnet_info *vi = rq->vq->vdev->priv;
328         struct net_device *dev = vi->dev;
329         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
330         struct sk_buff *skb;
331         struct page *page;
332         struct skb_vnet_hdr *hdr;
333
334         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
335                 pr_debug("%s: short packet %i\n", dev->name, len);
336                 dev->stats.rx_length_errors++;
337                 if (vi->mergeable_rx_bufs || vi->big_packets)
338                         give_pages(rq, buf);
339                 else
340                         dev_kfree_skb(buf);
341                 return;
342         }
343
344         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
345                 skb = buf;
346                 len -= sizeof(struct virtio_net_hdr);
347                 skb_trim(skb, len);
348         } else {
349                 page = buf;
350                 skb = page_to_skb(rq, page, len);
351                 if (unlikely(!skb)) {
352                         dev->stats.rx_dropped++;
353                         give_pages(rq, page);
354                         return;
355                 }
356                 if (vi->mergeable_rx_bufs)
357                         if (receive_mergeable(rq, skb)) {
358                                 dev_kfree_skb(skb);
359                                 return;
360                         }
361         }
362
363         hdr = skb_vnet_hdr(skb);
364
365         u64_stats_update_begin(&stats->rx_syncp);
366         stats->rx_bytes += skb->len;
367         stats->rx_packets++;
368         u64_stats_update_end(&stats->rx_syncp);
369
370         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
371                 pr_debug("Needs csum!\n");
372                 if (!skb_partial_csum_set(skb,
373                                           hdr->hdr.csum_start,
374                                           hdr->hdr.csum_offset))
375                         goto frame_err;
376         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
377                 skb->ip_summed = CHECKSUM_UNNECESSARY;
378         }
379
380         skb->protocol = eth_type_trans(skb, dev);
381         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
382                  ntohs(skb->protocol), skb->len, skb->pkt_type);
383
384         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
385                 pr_debug("GSO!\n");
386                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
387                 case VIRTIO_NET_HDR_GSO_TCPV4:
388                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
389                         break;
390                 case VIRTIO_NET_HDR_GSO_UDP:
391                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
392                         break;
393                 case VIRTIO_NET_HDR_GSO_TCPV6:
394                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
395                         break;
396                 default:
397                         net_warn_ratelimited("%s: bad gso type %u.\n",
398                                              dev->name, hdr->hdr.gso_type);
399                         goto frame_err;
400                 }
401
402                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
403                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
404
405                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
406                 if (skb_shinfo(skb)->gso_size == 0) {
407                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
408                         goto frame_err;
409                 }
410
411                 /* Header must be checked, and gso_segs computed. */
412                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
413                 skb_shinfo(skb)->gso_segs = 0;
414         }
415
416         netif_receive_skb(skb);
417         return;
418
419 frame_err:
420         dev->stats.rx_frame_errors++;
421         dev_kfree_skb(skb);
422 }
423
424 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
425 {
426         struct virtnet_info *vi = rq->vq->vdev->priv;
427         struct sk_buff *skb;
428         struct skb_vnet_hdr *hdr;
429         int err;
430
431         skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
432         if (unlikely(!skb))
433                 return -ENOMEM;
434
435         skb_put(skb, MAX_PACKET_LEN);
436
437         hdr = skb_vnet_hdr(skb);
438         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
439
440         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
441
442         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp);
443         if (err < 0)
444                 dev_kfree_skb(skb);
445
446         return err;
447 }
448
449 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
450 {
451         struct page *first, *list = NULL;
452         char *p;
453         int i, err, offset;
454
455         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
456         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
457                 first = get_a_page(rq, gfp);
458                 if (!first) {
459                         if (list)
460                                 give_pages(rq, list);
461                         return -ENOMEM;
462                 }
463                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
464
465                 /* chain new page in list head to match sg */
466                 first->private = (unsigned long)list;
467                 list = first;
468         }
469
470         first = get_a_page(rq, gfp);
471         if (!first) {
472                 give_pages(rq, list);
473                 return -ENOMEM;
474         }
475         p = page_address(first);
476
477         /* rq->sg[0], rq->sg[1] share the same page */
478         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
479         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
480
481         /* rq->sg[1] for data packet, from offset */
482         offset = sizeof(struct padded_vnet_hdr);
483         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
484
485         /* chain first in list head */
486         first->private = (unsigned long)list;
487         err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2,
488                                 first, gfp);
489         if (err < 0)
490                 give_pages(rq, first);
491
492         return err;
493 }
494
495 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
496 {
497         struct page *page;
498         int err;
499
500         page = get_a_page(rq, gfp);
501         if (!page)
502                 return -ENOMEM;
503
504         sg_init_one(rq->sg, page_address(page), PAGE_SIZE);
505
506         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp);
507         if (err < 0)
508                 give_pages(rq, page);
509
510         return err;
511 }
512
513 /*
514  * Returns false if we couldn't fill entirely (OOM).
515  *
516  * Normally run in the receive path, but can also be run from ndo_open
517  * before we're receiving packets, or from refill_work which is
518  * careful to disable receiving (using napi_disable).
519  */
520 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
521 {
522         struct virtnet_info *vi = rq->vq->vdev->priv;
523         int err;
524         bool oom;
525
526         do {
527                 if (vi->mergeable_rx_bufs)
528                         err = add_recvbuf_mergeable(rq, gfp);
529                 else if (vi->big_packets)
530                         err = add_recvbuf_big(rq, gfp);
531                 else
532                         err = add_recvbuf_small(rq, gfp);
533
534                 oom = err == -ENOMEM;
535                 if (err)
536                         break;
537                 ++rq->num;
538         } while (rq->vq->num_free);
539         if (unlikely(rq->num > rq->max))
540                 rq->max = rq->num;
541         virtqueue_kick(rq->vq);
542         return !oom;
543 }
544
545 static void skb_recv_done(struct virtqueue *rvq)
546 {
547         struct virtnet_info *vi = rvq->vdev->priv;
548         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
549
550         /* Schedule NAPI, Suppress further interrupts if successful. */
551         if (napi_schedule_prep(&rq->napi)) {
552                 virtqueue_disable_cb(rvq);
553                 __napi_schedule(&rq->napi);
554         }
555 }
556
557 static void virtnet_napi_enable(struct receive_queue *rq)
558 {
559         napi_enable(&rq->napi);
560
561         /* If all buffers were filled by other side before we napi_enabled, we
562          * won't get another interrupt, so process any outstanding packets
563          * now.  virtnet_poll wants re-enable the queue, so we disable here.
564          * We synchronize against interrupts via NAPI_STATE_SCHED */
565         if (napi_schedule_prep(&rq->napi)) {
566                 virtqueue_disable_cb(rq->vq);
567                 local_bh_disable();
568                 __napi_schedule(&rq->napi);
569                 local_bh_enable();
570         }
571 }
572
573 static void refill_work(struct work_struct *work)
574 {
575         struct virtnet_info *vi =
576                 container_of(work, struct virtnet_info, refill.work);
577         bool still_empty;
578         int i;
579
580         for (i = 0; i < vi->max_queue_pairs; i++) {
581                 struct receive_queue *rq = &vi->rq[i];
582
583                 napi_disable(&rq->napi);
584                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
585                 virtnet_napi_enable(rq);
586
587                 /* In theory, this can happen: if we don't get any buffers in
588                  * we will *never* try to fill again.
589                  */
590                 if (still_empty)
591                         schedule_delayed_work(&vi->refill, HZ/2);
592         }
593 }
594
595 static int virtnet_poll(struct napi_struct *napi, int budget)
596 {
597         struct receive_queue *rq =
598                 container_of(napi, struct receive_queue, napi);
599         struct virtnet_info *vi = rq->vq->vdev->priv;
600         void *buf;
601         unsigned int len, received = 0;
602
603 again:
604         while (received < budget &&
605                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
606                 receive_buf(rq, buf, len);
607                 --rq->num;
608                 received++;
609         }
610
611         if (rq->num < rq->max / 2) {
612                 if (!try_fill_recv(rq, GFP_ATOMIC))
613                         schedule_delayed_work(&vi->refill, 0);
614         }
615
616         /* Out of packets? */
617         if (received < budget) {
618                 napi_complete(napi);
619                 if (unlikely(!virtqueue_enable_cb(rq->vq)) &&
620                     napi_schedule_prep(napi)) {
621                         virtqueue_disable_cb(rq->vq);
622                         __napi_schedule(napi);
623                         goto again;
624                 }
625         }
626
627         return received;
628 }
629
630 static int virtnet_open(struct net_device *dev)
631 {
632         struct virtnet_info *vi = netdev_priv(dev);
633         int i;
634
635         for (i = 0; i < vi->max_queue_pairs; i++) {
636                 /* Make sure we have some buffers: if oom use wq. */
637                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
638                         schedule_delayed_work(&vi->refill, 0);
639                 virtnet_napi_enable(&vi->rq[i]);
640         }
641
642         return 0;
643 }
644
645 static void free_old_xmit_skbs(struct send_queue *sq)
646 {
647         struct sk_buff *skb;
648         unsigned int len;
649         struct virtnet_info *vi = sq->vq->vdev->priv;
650         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
651
652         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
653                 pr_debug("Sent skb %p\n", skb);
654
655                 u64_stats_update_begin(&stats->tx_syncp);
656                 stats->tx_bytes += skb->len;
657                 stats->tx_packets++;
658                 u64_stats_update_end(&stats->tx_syncp);
659
660                 dev_kfree_skb_any(skb);
661         }
662 }
663
664 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
665 {
666         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
667         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
668         struct virtnet_info *vi = sq->vq->vdev->priv;
669         unsigned num_sg;
670
671         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
672
673         if (skb->ip_summed == CHECKSUM_PARTIAL) {
674                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
675                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
676                 hdr->hdr.csum_offset = skb->csum_offset;
677         } else {
678                 hdr->hdr.flags = 0;
679                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
680         }
681
682         if (skb_is_gso(skb)) {
683                 hdr->hdr.hdr_len = skb_headlen(skb);
684                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
685                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
686                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
687                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
688                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
689                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
690                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
691                 else
692                         BUG();
693                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
694                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
695         } else {
696                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
697                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
698         }
699
700         hdr->mhdr.num_buffers = 0;
701
702         /* Encode metadata header at front. */
703         if (vi->mergeable_rx_bufs)
704                 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
705         else
706                 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
707
708         num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
709         return virtqueue_add_buf(sq->vq, sq->sg, num_sg,
710                                  0, skb, GFP_ATOMIC);
711 }
712
713 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
714 {
715         struct virtnet_info *vi = netdev_priv(dev);
716         int qnum = skb_get_queue_mapping(skb);
717         struct send_queue *sq = &vi->sq[qnum];
718         int err;
719
720         /* Free up any pending old buffers before queueing new ones. */
721         free_old_xmit_skbs(sq);
722
723         /* Try to transmit */
724         err = xmit_skb(sq, skb);
725
726         /* This should not happen! */
727         if (unlikely(err)) {
728                 dev->stats.tx_fifo_errors++;
729                 if (net_ratelimit())
730                         dev_warn(&dev->dev,
731                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
732                 dev->stats.tx_dropped++;
733                 kfree_skb(skb);
734                 return NETDEV_TX_OK;
735         }
736         virtqueue_kick(sq->vq);
737
738         /* Don't wait up for transmitted skbs to be freed. */
739         skb_orphan(skb);
740         nf_reset(skb);
741
742         /* Apparently nice girls don't return TX_BUSY; stop the queue
743          * before it gets out of hand.  Naturally, this wastes entries. */
744         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
745                 netif_stop_subqueue(dev, qnum);
746                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
747                         /* More just got used, free them then recheck. */
748                         free_old_xmit_skbs(sq);
749                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
750                                 netif_start_subqueue(dev, qnum);
751                                 virtqueue_disable_cb(sq->vq);
752                         }
753                 }
754         }
755
756         return NETDEV_TX_OK;
757 }
758
759 static int virtnet_set_mac_address(struct net_device *dev, void *p)
760 {
761         struct virtnet_info *vi = netdev_priv(dev);
762         struct virtio_device *vdev = vi->vdev;
763         int ret;
764
765         ret = eth_mac_addr(dev, p);
766         if (ret)
767                 return ret;
768
769         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
770                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
771                                   dev->dev_addr, dev->addr_len);
772
773         return 0;
774 }
775
776 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
777                                                struct rtnl_link_stats64 *tot)
778 {
779         struct virtnet_info *vi = netdev_priv(dev);
780         int cpu;
781         unsigned int start;
782
783         for_each_possible_cpu(cpu) {
784                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
785                 u64 tpackets, tbytes, rpackets, rbytes;
786
787                 do {
788                         start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
789                         tpackets = stats->tx_packets;
790                         tbytes   = stats->tx_bytes;
791                 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
792
793                 do {
794                         start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
795                         rpackets = stats->rx_packets;
796                         rbytes   = stats->rx_bytes;
797                 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
798
799                 tot->rx_packets += rpackets;
800                 tot->tx_packets += tpackets;
801                 tot->rx_bytes   += rbytes;
802                 tot->tx_bytes   += tbytes;
803         }
804
805         tot->tx_dropped = dev->stats.tx_dropped;
806         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
807         tot->rx_dropped = dev->stats.rx_dropped;
808         tot->rx_length_errors = dev->stats.rx_length_errors;
809         tot->rx_frame_errors = dev->stats.rx_frame_errors;
810
811         return tot;
812 }
813
814 #ifdef CONFIG_NET_POLL_CONTROLLER
815 static void virtnet_netpoll(struct net_device *dev)
816 {
817         struct virtnet_info *vi = netdev_priv(dev);
818         int i;
819
820         for (i = 0; i < vi->curr_queue_pairs; i++)
821                 napi_schedule(&vi->rq[i].napi);
822 }
823 #endif
824
825 /*
826  * Send command via the control virtqueue and check status.  Commands
827  * supported by the hypervisor, as indicated by feature bits, should
828  * never fail unless improperly formated.
829  */
830 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
831                                  struct scatterlist *data, int out, int in)
832 {
833         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
834         struct virtio_net_ctrl_hdr ctrl;
835         virtio_net_ctrl_ack status = ~0;
836         unsigned int tmp;
837         int i;
838
839         /* Caller should know better */
840         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
841                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
842
843         out++; /* Add header */
844         in++; /* Add return status */
845
846         ctrl.class = class;
847         ctrl.cmd = cmd;
848
849         sg_init_table(sg, out + in);
850
851         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
852         for_each_sg(data, s, out + in - 2, i)
853                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
854         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
855
856         BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
857
858         virtqueue_kick(vi->cvq);
859
860         /*
861          * Spin for a response, the kick causes an ioport write, trapping
862          * into the hypervisor, so the request should be handled immediately.
863          */
864         while (!virtqueue_get_buf(vi->cvq, &tmp))
865                 cpu_relax();
866
867         return status == VIRTIO_NET_OK;
868 }
869
870 static void virtnet_ack_link_announce(struct virtnet_info *vi)
871 {
872         rtnl_lock();
873         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
874                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
875                                   0, 0))
876                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
877         rtnl_unlock();
878 }
879
880 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
881 {
882         struct scatterlist sg;
883         struct virtio_net_ctrl_mq s;
884         struct net_device *dev = vi->dev;
885
886         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
887                 return 0;
888
889         s.virtqueue_pairs = queue_pairs;
890         sg_init_one(&sg, &s, sizeof(s));
891
892         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
893                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){
894                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
895                          queue_pairs);
896                 return -EINVAL;
897         } else
898                 vi->curr_queue_pairs = queue_pairs;
899
900         return 0;
901 }
902
903 static int virtnet_close(struct net_device *dev)
904 {
905         struct virtnet_info *vi = netdev_priv(dev);
906         int i;
907
908         /* Make sure refill_work doesn't re-enable napi! */
909         cancel_delayed_work_sync(&vi->refill);
910
911         for (i = 0; i < vi->max_queue_pairs; i++)
912                 napi_disable(&vi->rq[i].napi);
913
914         return 0;
915 }
916
917 static void virtnet_set_rx_mode(struct net_device *dev)
918 {
919         struct virtnet_info *vi = netdev_priv(dev);
920         struct scatterlist sg[2];
921         u8 promisc, allmulti;
922         struct virtio_net_ctrl_mac *mac_data;
923         struct netdev_hw_addr *ha;
924         int uc_count;
925         int mc_count;
926         void *buf;
927         int i;
928
929         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
930         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
931                 return;
932
933         promisc = ((dev->flags & IFF_PROMISC) != 0);
934         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
935
936         sg_init_one(sg, &promisc, sizeof(promisc));
937
938         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
939                                   VIRTIO_NET_CTRL_RX_PROMISC,
940                                   sg, 1, 0))
941                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
942                          promisc ? "en" : "dis");
943
944         sg_init_one(sg, &allmulti, sizeof(allmulti));
945
946         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
947                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
948                                   sg, 1, 0))
949                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
950                          allmulti ? "en" : "dis");
951
952         uc_count = netdev_uc_count(dev);
953         mc_count = netdev_mc_count(dev);
954         /* MAC filter - use one buffer for both lists */
955         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
956                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
957         mac_data = buf;
958         if (!buf) {
959                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
960                 return;
961         }
962
963         sg_init_table(sg, 2);
964
965         /* Store the unicast list and count in the front of the buffer */
966         mac_data->entries = uc_count;
967         i = 0;
968         netdev_for_each_uc_addr(ha, dev)
969                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
970
971         sg_set_buf(&sg[0], mac_data,
972                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
973
974         /* multicast list and count fill the end */
975         mac_data = (void *)&mac_data->macs[uc_count][0];
976
977         mac_data->entries = mc_count;
978         i = 0;
979         netdev_for_each_mc_addr(ha, dev)
980                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
981
982         sg_set_buf(&sg[1], mac_data,
983                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
984
985         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
986                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
987                                   sg, 2, 0))
988                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
989
990         kfree(buf);
991 }
992
993 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
994 {
995         struct virtnet_info *vi = netdev_priv(dev);
996         struct scatterlist sg;
997
998         sg_init_one(&sg, &vid, sizeof(vid));
999
1000         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1001                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
1002                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1003         return 0;
1004 }
1005
1006 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
1007 {
1008         struct virtnet_info *vi = netdev_priv(dev);
1009         struct scatterlist sg;
1010
1011         sg_init_one(&sg, &vid, sizeof(vid));
1012
1013         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1014                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
1015                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1016         return 0;
1017 }
1018
1019 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1020 {
1021         int i;
1022         int cpu;
1023
1024         if (vi->affinity_hint_set) {
1025                 for (i = 0; i < vi->max_queue_pairs; i++) {
1026                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1027                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1028                 }
1029
1030                 vi->affinity_hint_set = false;
1031         }
1032
1033         i = 0;
1034         for_each_online_cpu(cpu) {
1035                 if (cpu == hcpu) {
1036                         *per_cpu_ptr(vi->vq_index, cpu) = -1;
1037                 } else {
1038                         *per_cpu_ptr(vi->vq_index, cpu) =
1039                                 ++i % vi->curr_queue_pairs;
1040                 }
1041         }
1042 }
1043
1044 static void virtnet_set_affinity(struct virtnet_info *vi)
1045 {
1046         int i;
1047         int cpu;
1048
1049         /* In multiqueue mode, when the number of cpu is equal to the number of
1050          * queue pairs, we let the queue pairs to be private to one cpu by
1051          * setting the affinity hint to eliminate the contention.
1052          */
1053         if (vi->curr_queue_pairs == 1 ||
1054             vi->max_queue_pairs != num_online_cpus()) {
1055                 virtnet_clean_affinity(vi, -1);
1056                 return;
1057         }
1058
1059         i = 0;
1060         for_each_online_cpu(cpu) {
1061                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1062                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1063                 *per_cpu_ptr(vi->vq_index, cpu) = i;
1064                 i++;
1065         }
1066
1067         vi->affinity_hint_set = true;
1068 }
1069
1070 static void virtnet_get_ringparam(struct net_device *dev,
1071                                 struct ethtool_ringparam *ring)
1072 {
1073         struct virtnet_info *vi = netdev_priv(dev);
1074
1075         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1076         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1077         ring->rx_pending = ring->rx_max_pending;
1078         ring->tx_pending = ring->tx_max_pending;
1079 }
1080
1081
1082 static void virtnet_get_drvinfo(struct net_device *dev,
1083                                 struct ethtool_drvinfo *info)
1084 {
1085         struct virtnet_info *vi = netdev_priv(dev);
1086         struct virtio_device *vdev = vi->vdev;
1087
1088         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1089         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1090         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1091
1092 }
1093
1094 /* TODO: Eliminate OOO packets during switching */
1095 static int virtnet_set_channels(struct net_device *dev,
1096                                 struct ethtool_channels *channels)
1097 {
1098         struct virtnet_info *vi = netdev_priv(dev);
1099         u16 queue_pairs = channels->combined_count;
1100         int err;
1101
1102         /* We don't support separate rx/tx channels.
1103          * We don't allow setting 'other' channels.
1104          */
1105         if (channels->rx_count || channels->tx_count || channels->other_count)
1106                 return -EINVAL;
1107
1108         if (queue_pairs > vi->max_queue_pairs)
1109                 return -EINVAL;
1110
1111         get_online_cpus();
1112         err = virtnet_set_queues(vi, queue_pairs);
1113         if (!err) {
1114                 netif_set_real_num_tx_queues(dev, queue_pairs);
1115                 netif_set_real_num_rx_queues(dev, queue_pairs);
1116
1117                 virtnet_set_affinity(vi);
1118         }
1119         put_online_cpus();
1120
1121         return err;
1122 }
1123
1124 static void virtnet_get_channels(struct net_device *dev,
1125                                  struct ethtool_channels *channels)
1126 {
1127         struct virtnet_info *vi = netdev_priv(dev);
1128
1129         channels->combined_count = vi->curr_queue_pairs;
1130         channels->max_combined = vi->max_queue_pairs;
1131         channels->max_other = 0;
1132         channels->rx_count = 0;
1133         channels->tx_count = 0;
1134         channels->other_count = 0;
1135 }
1136
1137 static const struct ethtool_ops virtnet_ethtool_ops = {
1138         .get_drvinfo = virtnet_get_drvinfo,
1139         .get_link = ethtool_op_get_link,
1140         .get_ringparam = virtnet_get_ringparam,
1141         .set_channels = virtnet_set_channels,
1142         .get_channels = virtnet_get_channels,
1143 };
1144
1145 #define MIN_MTU 68
1146 #define MAX_MTU 65535
1147
1148 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1149 {
1150         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1151                 return -EINVAL;
1152         dev->mtu = new_mtu;
1153         return 0;
1154 }
1155
1156 /* To avoid contending a lock hold by a vcpu who would exit to host, select the
1157  * txq based on the processor id.
1158  */
1159 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
1160 {
1161         int txq;
1162         struct virtnet_info *vi = netdev_priv(dev);
1163
1164         if (skb_rx_queue_recorded(skb)) {
1165                 txq = skb_get_rx_queue(skb);
1166         } else {
1167                 txq = *__this_cpu_ptr(vi->vq_index);
1168                 if (txq == -1)
1169                         txq = 0;
1170         }
1171
1172         while (unlikely(txq >= dev->real_num_tx_queues))
1173                 txq -= dev->real_num_tx_queues;
1174
1175         return txq;
1176 }
1177
1178 static const struct net_device_ops virtnet_netdev = {
1179         .ndo_open            = virtnet_open,
1180         .ndo_stop            = virtnet_close,
1181         .ndo_start_xmit      = start_xmit,
1182         .ndo_validate_addr   = eth_validate_addr,
1183         .ndo_set_mac_address = virtnet_set_mac_address,
1184         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1185         .ndo_change_mtu      = virtnet_change_mtu,
1186         .ndo_get_stats64     = virtnet_stats,
1187         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1188         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1189         .ndo_select_queue     = virtnet_select_queue,
1190 #ifdef CONFIG_NET_POLL_CONTROLLER
1191         .ndo_poll_controller = virtnet_netpoll,
1192 #endif
1193 };
1194
1195 static void virtnet_config_changed_work(struct work_struct *work)
1196 {
1197         struct virtnet_info *vi =
1198                 container_of(work, struct virtnet_info, config_work);
1199         u16 v;
1200
1201         mutex_lock(&vi->config_lock);
1202         if (!vi->config_enable)
1203                 goto done;
1204
1205         if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
1206                               offsetof(struct virtio_net_config, status),
1207                               &v) < 0)
1208                 goto done;
1209
1210         if (v & VIRTIO_NET_S_ANNOUNCE) {
1211                 netdev_notify_peers(vi->dev);
1212                 virtnet_ack_link_announce(vi);
1213         }
1214
1215         /* Ignore unknown (future) status bits */
1216         v &= VIRTIO_NET_S_LINK_UP;
1217
1218         if (vi->status == v)
1219                 goto done;
1220
1221         vi->status = v;
1222
1223         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1224                 netif_carrier_on(vi->dev);
1225                 netif_tx_wake_all_queues(vi->dev);
1226         } else {
1227                 netif_carrier_off(vi->dev);
1228                 netif_tx_stop_all_queues(vi->dev);
1229         }
1230 done:
1231         mutex_unlock(&vi->config_lock);
1232 }
1233
1234 static void virtnet_config_changed(struct virtio_device *vdev)
1235 {
1236         struct virtnet_info *vi = vdev->priv;
1237
1238         schedule_work(&vi->config_work);
1239 }
1240
1241 static void virtnet_free_queues(struct virtnet_info *vi)
1242 {
1243         kfree(vi->rq);
1244         kfree(vi->sq);
1245 }
1246
1247 static void free_receive_bufs(struct virtnet_info *vi)
1248 {
1249         int i;
1250
1251         for (i = 0; i < vi->max_queue_pairs; i++) {
1252                 while (vi->rq[i].pages)
1253                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1254         }
1255 }
1256
1257 static void free_unused_bufs(struct virtnet_info *vi)
1258 {
1259         void *buf;
1260         int i;
1261
1262         for (i = 0; i < vi->max_queue_pairs; i++) {
1263                 struct virtqueue *vq = vi->sq[i].vq;
1264                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1265                         dev_kfree_skb(buf);
1266         }
1267
1268         for (i = 0; i < vi->max_queue_pairs; i++) {
1269                 struct virtqueue *vq = vi->rq[i].vq;
1270
1271                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1272                         if (vi->mergeable_rx_bufs || vi->big_packets)
1273                                 give_pages(&vi->rq[i], buf);
1274                         else
1275                                 dev_kfree_skb(buf);
1276                         --vi->rq[i].num;
1277                 }
1278                 BUG_ON(vi->rq[i].num != 0);
1279         }
1280 }
1281
1282 static void virtnet_del_vqs(struct virtnet_info *vi)
1283 {
1284         struct virtio_device *vdev = vi->vdev;
1285
1286         virtnet_clean_affinity(vi, -1);
1287
1288         vdev->config->del_vqs(vdev);
1289
1290         virtnet_free_queues(vi);
1291 }
1292
1293 static int virtnet_find_vqs(struct virtnet_info *vi)
1294 {
1295         vq_callback_t **callbacks;
1296         struct virtqueue **vqs;
1297         int ret = -ENOMEM;
1298         int i, total_vqs;
1299         const char **names;
1300
1301         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1302          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1303          * possible control vq.
1304          */
1305         total_vqs = vi->max_queue_pairs * 2 +
1306                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1307
1308         /* Allocate space for find_vqs parameters */
1309         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1310         if (!vqs)
1311                 goto err_vq;
1312         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1313         if (!callbacks)
1314                 goto err_callback;
1315         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1316         if (!names)
1317                 goto err_names;
1318
1319         /* Parameters for control virtqueue, if any */
1320         if (vi->has_cvq) {
1321                 callbacks[total_vqs - 1] = NULL;
1322                 names[total_vqs - 1] = "control";
1323         }
1324
1325         /* Allocate/initialize parameters for send/receive virtqueues */
1326         for (i = 0; i < vi->max_queue_pairs; i++) {
1327                 callbacks[rxq2vq(i)] = skb_recv_done;
1328                 callbacks[txq2vq(i)] = skb_xmit_done;
1329                 sprintf(vi->rq[i].name, "input.%d", i);
1330                 sprintf(vi->sq[i].name, "output.%d", i);
1331                 names[rxq2vq(i)] = vi->rq[i].name;
1332                 names[txq2vq(i)] = vi->sq[i].name;
1333         }
1334
1335         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1336                                          names);
1337         if (ret)
1338                 goto err_find;
1339
1340         if (vi->has_cvq) {
1341                 vi->cvq = vqs[total_vqs - 1];
1342                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1343                         vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1344         }
1345
1346         for (i = 0; i < vi->max_queue_pairs; i++) {
1347                 vi->rq[i].vq = vqs[rxq2vq(i)];
1348                 vi->sq[i].vq = vqs[txq2vq(i)];
1349         }
1350
1351         kfree(names);
1352         kfree(callbacks);
1353         kfree(vqs);
1354
1355         return 0;
1356
1357 err_find:
1358         kfree(names);
1359 err_names:
1360         kfree(callbacks);
1361 err_callback:
1362         kfree(vqs);
1363 err_vq:
1364         return ret;
1365 }
1366
1367 static int virtnet_alloc_queues(struct virtnet_info *vi)
1368 {
1369         int i;
1370
1371         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1372         if (!vi->sq)
1373                 goto err_sq;
1374         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1375         if (!vi->rq)
1376                 goto err_rq;
1377
1378         INIT_DELAYED_WORK(&vi->refill, refill_work);
1379         for (i = 0; i < vi->max_queue_pairs; i++) {
1380                 vi->rq[i].pages = NULL;
1381                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1382                                napi_weight);
1383
1384                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1385                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1386         }
1387
1388         return 0;
1389
1390 err_rq:
1391         kfree(vi->sq);
1392 err_sq:
1393         return -ENOMEM;
1394 }
1395
1396 static int init_vqs(struct virtnet_info *vi)
1397 {
1398         int ret;
1399
1400         /* Allocate send & receive queues */
1401         ret = virtnet_alloc_queues(vi);
1402         if (ret)
1403                 goto err;
1404
1405         ret = virtnet_find_vqs(vi);
1406         if (ret)
1407                 goto err_free;
1408
1409         get_online_cpus();
1410         virtnet_set_affinity(vi);
1411         put_online_cpus();
1412
1413         return 0;
1414
1415 err_free:
1416         virtnet_free_queues(vi);
1417 err:
1418         return ret;
1419 }
1420
1421 static int virtnet_probe(struct virtio_device *vdev)
1422 {
1423         int i, err;
1424         struct net_device *dev;
1425         struct virtnet_info *vi;
1426         u16 max_queue_pairs;
1427
1428         /* Find if host supports multiqueue virtio_net device */
1429         err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
1430                                 offsetof(struct virtio_net_config,
1431                                 max_virtqueue_pairs), &max_queue_pairs);
1432
1433         /* We need at least 2 queue's */
1434         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1435             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1436             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1437                 max_queue_pairs = 1;
1438
1439         /* Allocate ourselves a network device with room for our info */
1440         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1441         if (!dev)
1442                 return -ENOMEM;
1443
1444         /* Set up network device as normal. */
1445         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1446         dev->netdev_ops = &virtnet_netdev;
1447         dev->features = NETIF_F_HIGHDMA;
1448
1449         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1450         SET_NETDEV_DEV(dev, &vdev->dev);
1451
1452         /* Do we support "hardware" checksums? */
1453         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1454                 /* This opens up the world of extra features. */
1455                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1456                 if (csum)
1457                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1458
1459                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1460                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1461                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1462                 }
1463                 /* Individual feature bits: what can host handle? */
1464                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1465                         dev->hw_features |= NETIF_F_TSO;
1466                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1467                         dev->hw_features |= NETIF_F_TSO6;
1468                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1469                         dev->hw_features |= NETIF_F_TSO_ECN;
1470                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1471                         dev->hw_features |= NETIF_F_UFO;
1472
1473                 if (gso)
1474                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1475                 /* (!csum && gso) case will be fixed by register_netdev() */
1476         }
1477
1478         /* Configuration may specify what MAC to use.  Otherwise random. */
1479         if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1480                                   offsetof(struct virtio_net_config, mac),
1481                                   dev->dev_addr, dev->addr_len) < 0)
1482                 eth_hw_addr_random(dev);
1483
1484         /* Set up our device-specific information */
1485         vi = netdev_priv(dev);
1486         vi->dev = dev;
1487         vi->vdev = vdev;
1488         vdev->priv = vi;
1489         vi->stats = alloc_percpu(struct virtnet_stats);
1490         err = -ENOMEM;
1491         if (vi->stats == NULL)
1492                 goto free;
1493
1494         vi->vq_index = alloc_percpu(int);
1495         if (vi->vq_index == NULL)
1496                 goto free_stats;
1497
1498         mutex_init(&vi->config_lock);
1499         vi->config_enable = true;
1500         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1501
1502         /* If we can receive ANY GSO packets, we must allocate large ones. */
1503         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1504             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1505             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1506                 vi->big_packets = true;
1507
1508         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1509                 vi->mergeable_rx_bufs = true;
1510
1511         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1512                 vi->has_cvq = true;
1513
1514         /* Use single tx/rx queue pair as default */
1515         vi->curr_queue_pairs = 1;
1516         vi->max_queue_pairs = max_queue_pairs;
1517
1518         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1519         err = init_vqs(vi);
1520         if (err)
1521                 goto free_index;
1522
1523         netif_set_real_num_tx_queues(dev, 1);
1524         netif_set_real_num_rx_queues(dev, 1);
1525
1526         err = register_netdev(dev);
1527         if (err) {
1528                 pr_debug("virtio_net: registering device failed\n");
1529                 goto free_vqs;
1530         }
1531
1532         /* Last of all, set up some receive buffers. */
1533         for (i = 0; i < vi->max_queue_pairs; i++) {
1534                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1535
1536                 /* If we didn't even get one input buffer, we're useless. */
1537                 if (vi->rq[i].num == 0) {
1538                         free_unused_bufs(vi);
1539                         err = -ENOMEM;
1540                         goto free_recv_bufs;
1541                 }
1542         }
1543
1544         /* Assume link up if device can't report link status,
1545            otherwise get link status from config. */
1546         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1547                 netif_carrier_off(dev);
1548                 schedule_work(&vi->config_work);
1549         } else {
1550                 vi->status = VIRTIO_NET_S_LINK_UP;
1551                 netif_carrier_on(dev);
1552         }
1553
1554         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1555                  dev->name, max_queue_pairs);
1556
1557         return 0;
1558
1559 free_recv_bufs:
1560         free_receive_bufs(vi);
1561         unregister_netdev(dev);
1562 free_vqs:
1563         cancel_delayed_work_sync(&vi->refill);
1564         virtnet_del_vqs(vi);
1565 free_index:
1566         free_percpu(vi->vq_index);
1567 free_stats:
1568         free_percpu(vi->stats);
1569 free:
1570         free_netdev(dev);
1571         return err;
1572 }
1573
1574 static void remove_vq_common(struct virtnet_info *vi)
1575 {
1576         vi->vdev->config->reset(vi->vdev);
1577
1578         /* Free unused buffers in both send and recv, if any. */
1579         free_unused_bufs(vi);
1580
1581         free_receive_bufs(vi);
1582
1583         virtnet_del_vqs(vi);
1584 }
1585
1586 static void virtnet_remove(struct virtio_device *vdev)
1587 {
1588         struct virtnet_info *vi = vdev->priv;
1589
1590         /* Prevent config work handler from accessing the device. */
1591         mutex_lock(&vi->config_lock);
1592         vi->config_enable = false;
1593         mutex_unlock(&vi->config_lock);
1594
1595         unregister_netdev(vi->dev);
1596
1597         remove_vq_common(vi);
1598
1599         flush_work(&vi->config_work);
1600
1601         free_percpu(vi->vq_index);
1602         free_percpu(vi->stats);
1603         free_netdev(vi->dev);
1604 }
1605
1606 #ifdef CONFIG_PM
1607 static int virtnet_freeze(struct virtio_device *vdev)
1608 {
1609         struct virtnet_info *vi = vdev->priv;
1610         int i;
1611
1612         /* Prevent config work handler from accessing the device */
1613         mutex_lock(&vi->config_lock);
1614         vi->config_enable = false;
1615         mutex_unlock(&vi->config_lock);
1616
1617         netif_device_detach(vi->dev);
1618         cancel_delayed_work_sync(&vi->refill);
1619
1620         if (netif_running(vi->dev))
1621                 for (i = 0; i < vi->max_queue_pairs; i++) {
1622                         napi_disable(&vi->rq[i].napi);
1623                         netif_napi_del(&vi->rq[i].napi);
1624                 }
1625
1626         remove_vq_common(vi);
1627
1628         flush_work(&vi->config_work);
1629
1630         return 0;
1631 }
1632
1633 static int virtnet_restore(struct virtio_device *vdev)
1634 {
1635         struct virtnet_info *vi = vdev->priv;
1636         int err, i;
1637
1638         err = init_vqs(vi);
1639         if (err)
1640                 return err;
1641
1642         if (netif_running(vi->dev))
1643                 for (i = 0; i < vi->max_queue_pairs; i++)
1644                         virtnet_napi_enable(&vi->rq[i]);
1645
1646         netif_device_attach(vi->dev);
1647
1648         for (i = 0; i < vi->max_queue_pairs; i++)
1649                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1650                         schedule_delayed_work(&vi->refill, 0);
1651
1652         mutex_lock(&vi->config_lock);
1653         vi->config_enable = true;
1654         mutex_unlock(&vi->config_lock);
1655
1656         virtnet_set_queues(vi, vi->curr_queue_pairs);
1657
1658         return 0;
1659 }
1660 #endif
1661
1662 static struct virtio_device_id id_table[] = {
1663         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1664         { 0 },
1665 };
1666
1667 static unsigned int features[] = {
1668         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1669         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1670         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1671         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1672         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1673         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1674         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1675         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1676 };
1677
1678 static struct virtio_driver virtio_net_driver = {
1679         .feature_table = features,
1680         .feature_table_size = ARRAY_SIZE(features),
1681         .driver.name =  KBUILD_MODNAME,
1682         .driver.owner = THIS_MODULE,
1683         .id_table =     id_table,
1684         .probe =        virtnet_probe,
1685         .remove =       virtnet_remove,
1686         .config_changed = virtnet_config_changed,
1687 #ifdef CONFIG_PM
1688         .freeze =       virtnet_freeze,
1689         .restore =      virtnet_restore,
1690 #endif
1691 };
1692
1693 static int __init init(void)
1694 {
1695         return register_virtio_driver(&virtio_net_driver);
1696 }
1697
1698 static void __exit fini(void)
1699 {
1700         unregister_virtio_driver(&virtio_net_driver);
1701 }
1702 module_init(init);
1703 module_exit(fini);
1704
1705 MODULE_DEVICE_TABLE(virtio, id_table);
1706 MODULE_DESCRIPTION("Virtio network driver");
1707 MODULE_LICENSE("GPL");