Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/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, see <http://www.gnu.org/licenses/>.
 17  */
 18 //#define DEBUG
 19 #include <linux/netdevice.h>
 20 #include <linux/etherdevice.h>
 21 #include <linux/ethtool.h>
 22 #include <linux/module.h>
 23 #include <linux/virtio.h>
 24 #include <linux/virtio_net.h>
 25 #include <linux/scatterlist.h>
 26 #include <linux/if_vlan.h>
 27 #include <linux/slab.h>
 28 #include <linux/cpu.h>
 29 #include <linux/average.h>
 30 
 31 static int napi_weight = NAPI_POLL_WEIGHT;
 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 GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
 40 #define GOOD_COPY_LEN   128
 41 
 42 /* Weight used for the RX packet size EWMA. The average packet size is used to
 43  * determine the packet buffer size when refilling RX rings. As the entire RX
 44  * ring may be refilled at once, the weight is chosen so that the EWMA will be
 45  * insensitive to short-term, transient changes in packet size.
 46  */
 47 #define RECEIVE_AVG_WEIGHT 64
 48 
 49 /* Minimum alignment for mergeable packet buffers. */
 50 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
 51 
 52 #define VIRTNET_DRIVER_VERSION "1.0.0"
 53 
 54 struct virtnet_stats {
 55         struct u64_stats_sync tx_syncp;
 56         struct u64_stats_sync rx_syncp;
 57         u64 tx_bytes;
 58         u64 tx_packets;
 59 
 60         u64 rx_bytes;
 61         u64 rx_packets;
 62 };
 63 
 64 /* Internal representation of a send virtqueue */
 65 struct send_queue {
 66         /* Virtqueue associated with this send _queue */
 67         struct virtqueue *vq;
 68 
 69         /* TX: fragments + linear part + virtio header */
 70         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 71 
 72         /* Name of the send queue: output.$index */
 73         char name[40];
 74 };
 75 
 76 /* Internal representation of a receive virtqueue */
 77 struct receive_queue {
 78         /* Virtqueue associated with this receive_queue */
 79         struct virtqueue *vq;
 80 
 81         struct napi_struct napi;
 82 
 83         /* Chain pages by the private ptr. */
 84         struct page *pages;
 85 
 86         /* Average packet length for mergeable receive buffers. */
 87         struct ewma mrg_avg_pkt_len;
 88 
 89         /* Page frag for packet buffer allocation. */
 90         struct page_frag alloc_frag;
 91 
 92         /* RX: fragments + linear part + virtio header */
 93         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 94 
 95         /* Name of this receive queue: input.$index */
 96         char name[40];
 97 };
 98 
 99 struct virtnet_info {
100         struct virtio_device *vdev;
101         struct virtqueue *cvq;
102         struct net_device *dev;
103         struct send_queue *sq;
104         struct receive_queue *rq;
105         unsigned int status;
106 
107         /* Max # of queue pairs supported by the device */
108         u16 max_queue_pairs;
109 
110         /* # of queue pairs currently used by the driver */
111         u16 curr_queue_pairs;
112 
113         /* I like... big packets and I cannot lie! */
114         bool big_packets;
115 
116         /* Host will merge rx buffers for big packets (shake it! shake it!) */
117         bool mergeable_rx_bufs;
118 
119         /* Has control virtqueue */
120         bool has_cvq;
121 
122         /* Host can handle any s/g split between our header and packet data */
123         bool any_header_sg;
124 
125         /* enable config space updates */
126         bool config_enable;
127 
128         /* Active statistics */
129         struct virtnet_stats __percpu *stats;
130 
131         /* Work struct for refilling if we run low on memory. */
132         struct delayed_work refill;
133 
134         /* Work struct for config space updates */
135         struct work_struct config_work;
136 
137         /* Lock for config space updates */
138         struct mutex config_lock;
139 
140         /* Does the affinity hint is set for virtqueues? */
141         bool affinity_hint_set;
142 
143         /* CPU hot plug notifier */
144         struct notifier_block nb;
145 };
146 
147 struct skb_vnet_hdr {
148         union {
149                 struct virtio_net_hdr hdr;
150                 struct virtio_net_hdr_mrg_rxbuf mhdr;
151         };
152 };
153 
154 struct padded_vnet_hdr {
155         struct virtio_net_hdr hdr;
156         /*
157          * virtio_net_hdr should be in a separated sg buffer because of a
158          * QEMU bug, and data sg buffer shares same page with this header sg.
159          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
160          */
161         char padding[6];
162 };
163 
164 /* Converting between virtqueue no. and kernel tx/rx queue no.
165  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
166  */
167 static int vq2txq(struct virtqueue *vq)
168 {
169         return (vq->index - 1) / 2;
170 }
171 
172 static int txq2vq(int txq)
173 {
174         return txq * 2 + 1;
175 }
176 
177 static int vq2rxq(struct virtqueue *vq)
178 {
179         return vq->index / 2;
180 }
181 
182 static int rxq2vq(int rxq)
183 {
184         return rxq * 2;
185 }
186 
187 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
188 {
189         return (struct skb_vnet_hdr *)skb->cb;
190 }
191 
192 /*
193  * private is used to chain pages for big packets, put the whole
194  * most recent used list in the beginning for reuse
195  */
196 static void give_pages(struct receive_queue *rq, struct page *page)
197 {
198         struct page *end;
199 
200         /* Find end of list, sew whole thing into vi->rq.pages. */
201         for (end = page; end->private; end = (struct page *)end->private);
202         end->private = (unsigned long)rq->pages;
203         rq->pages = page;
204 }
205 
206 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
207 {
208         struct page *p = rq->pages;
209 
210         if (p) {
211                 rq->pages = (struct page *)p->private;
212                 /* clear private here, it is used to chain pages */
213                 p->private = 0;
214         } else
215                 p = alloc_page(gfp_mask);
216         return p;
217 }
218 
219 static void skb_xmit_done(struct virtqueue *vq)
220 {
221         struct virtnet_info *vi = vq->vdev->priv;
222 
223         /* Suppress further interrupts. */
224         virtqueue_disable_cb(vq);
225 
226         /* We were probably waiting for more output buffers. */
227         netif_wake_subqueue(vi->dev, vq2txq(vq));
228 }
229 
230 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
231 {
232         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
233         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
234 }
235 
236 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
237 {
238         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
239 
240 }
241 
242 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
243 {
244         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
245         return (unsigned long)buf | (size - 1);
246 }
247 
248 /* Called from bottom half context */
249 static struct sk_buff *page_to_skb(struct receive_queue *rq,
250                                    struct page *page, unsigned int offset,
251                                    unsigned int len, unsigned int truesize)
252 {
253         struct virtnet_info *vi = rq->vq->vdev->priv;
254         struct sk_buff *skb;
255         struct skb_vnet_hdr *hdr;
256         unsigned int copy, hdr_len, hdr_padded_len;
257         char *p;
258 
259         p = page_address(page) + offset;
260 
261         /* copy small packet so we can reuse these pages for small data */
262         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
263         if (unlikely(!skb))
264                 return NULL;
265 
266         hdr = skb_vnet_hdr(skb);
267 
268         if (vi->mergeable_rx_bufs) {
269                 hdr_len = sizeof hdr->mhdr;
270                 hdr_padded_len = sizeof hdr->mhdr;
271         } else {
272                 hdr_len = sizeof hdr->hdr;
273                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
274         }
275 
276         memcpy(hdr, p, hdr_len);
277 
278         len -= hdr_len;
279         offset += hdr_padded_len;
280         p += hdr_padded_len;
281 
282         copy = len;
283         if (copy > skb_tailroom(skb))
284                 copy = skb_tailroom(skb);
285         memcpy(skb_put(skb, copy), p, copy);
286 
287         len -= copy;
288         offset += copy;
289 
290         if (vi->mergeable_rx_bufs) {
291                 if (len)
292                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
293                 else
294                         put_page(page);
295                 return skb;
296         }
297 
298         /*
299          * Verify that we can indeed put this data into a skb.
300          * This is here to handle cases when the device erroneously
301          * tries to receive more than is possible. This is usually
302          * the case of a broken device.
303          */
304         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
305                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
306                 dev_kfree_skb(skb);
307                 return NULL;
308         }
309         BUG_ON(offset >= PAGE_SIZE);
310         while (len) {
311                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
312                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
313                                 frag_size, truesize);
314                 len -= frag_size;
315                 page = (struct page *)page->private;
316                 offset = 0;
317         }
318 
319         if (page)
320                 give_pages(rq, page);
321 
322         return skb;
323 }
324 
325 static struct sk_buff *receive_small(void *buf, unsigned int len)
326 {
327         struct sk_buff * skb = buf;
328 
329         len -= sizeof(struct virtio_net_hdr);
330         skb_trim(skb, len);
331 
332         return skb;
333 }
334 
335 static struct sk_buff *receive_big(struct net_device *dev,
336                                    struct receive_queue *rq,
337                                    void *buf,
338                                    unsigned int len)
339 {
340         struct page *page = buf;
341         struct sk_buff *skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
342 
343         if (unlikely(!skb))
344                 goto err;
345 
346         return skb;
347 
348 err:
349         dev->stats.rx_dropped++;
350         give_pages(rq, page);
351         return NULL;
352 }
353 
354 static struct sk_buff *receive_mergeable(struct net_device *dev,
355                                          struct receive_queue *rq,
356                                          unsigned long ctx,
357                                          unsigned int len)
358 {
359         void *buf = mergeable_ctx_to_buf_address(ctx);
360         struct skb_vnet_hdr *hdr = buf;
361         int num_buf = hdr->mhdr.num_buffers;
362         struct page *page = virt_to_head_page(buf);
363         int offset = buf - page_address(page);
364         unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
365 
366         struct sk_buff *head_skb = page_to_skb(rq, page, offset, len, truesize);
367         struct sk_buff *curr_skb = head_skb;
368 
369         if (unlikely(!curr_skb))
370                 goto err_skb;
371         while (--num_buf) {
372                 int num_skb_frags;
373 
374                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
375                 if (unlikely(!ctx)) {
376                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
377                                  dev->name, num_buf, hdr->mhdr.num_buffers);
378                         dev->stats.rx_length_errors++;
379                         goto err_buf;
380                 }
381 
382                 buf = mergeable_ctx_to_buf_address(ctx);
383                 page = virt_to_head_page(buf);
384 
385                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
386                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
387                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
388 
389                         if (unlikely(!nskb))
390                                 goto err_skb;
391                         if (curr_skb == head_skb)
392                                 skb_shinfo(curr_skb)->frag_list = nskb;
393                         else
394                                 curr_skb->next = nskb;
395                         curr_skb = nskb;
396                         head_skb->truesize += nskb->truesize;
397                         num_skb_frags = 0;
398                 }
399                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
400                 if (curr_skb != head_skb) {
401                         head_skb->data_len += len;
402                         head_skb->len += len;
403                         head_skb->truesize += truesize;
404                 }
405                 offset = buf - page_address(page);
406                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
407                         put_page(page);
408                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
409                                              len, truesize);
410                 } else {
411                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
412                                         offset, len, truesize);
413                 }
414         }
415 
416         ewma_add(&rq->mrg_avg_pkt_len, head_skb->len);
417         return head_skb;
418 
419 err_skb:
420         put_page(page);
421         while (--num_buf) {
422                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
423                 if (unlikely(!ctx)) {
424                         pr_debug("%s: rx error: %d buffers missing\n",
425                                  dev->name, num_buf);
426                         dev->stats.rx_length_errors++;
427                         break;
428                 }
429                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
430                 put_page(page);
431         }
432 err_buf:
433         dev->stats.rx_dropped++;
434         dev_kfree_skb(head_skb);
435         return NULL;
436 }
437 
438 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
439 {
440         struct virtnet_info *vi = rq->vq->vdev->priv;
441         struct net_device *dev = vi->dev;
442         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
443         struct sk_buff *skb;
444         struct skb_vnet_hdr *hdr;
445 
446         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
447                 pr_debug("%s: short packet %i\n", dev->name, len);
448                 dev->stats.rx_length_errors++;
449                 if (vi->mergeable_rx_bufs) {
450                         unsigned long ctx = (unsigned long)buf;
451                         void *base = mergeable_ctx_to_buf_address(ctx);
452                         put_page(virt_to_head_page(base));
453                 } else if (vi->big_packets) {
454                         give_pages(rq, buf);
455                 } else {
456                         dev_kfree_skb(buf);
457                 }
458                 return;
459         }
460 
461         if (vi->mergeable_rx_bufs)
462                 skb = receive_mergeable(dev, rq, (unsigned long)buf, len);
463         else if (vi->big_packets)
464                 skb = receive_big(dev, rq, buf, len);
465         else
466                 skb = receive_small(buf, len);
467 
468         if (unlikely(!skb))
469                 return;
470 
471         hdr = skb_vnet_hdr(skb);
472 
473         u64_stats_update_begin(&stats->rx_syncp);
474         stats->rx_bytes += skb->len;
475         stats->rx_packets++;
476         u64_stats_update_end(&stats->rx_syncp);
477 
478         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
479                 pr_debug("Needs csum!\n");
480                 if (!skb_partial_csum_set(skb,
481                                           hdr->hdr.csum_start,
482                                           hdr->hdr.csum_offset))
483                         goto frame_err;
484         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
485                 skb->ip_summed = CHECKSUM_UNNECESSARY;
486         }
487 
488         skb->protocol = eth_type_trans(skb, dev);
489         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
490                  ntohs(skb->protocol), skb->len, skb->pkt_type);
491 
492         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
493                 pr_debug("GSO!\n");
494                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
495                 case VIRTIO_NET_HDR_GSO_TCPV4:
496                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
497                         break;
498                 case VIRTIO_NET_HDR_GSO_UDP:
499                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
500                         break;
501                 case VIRTIO_NET_HDR_GSO_TCPV6:
502                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
503                         break;
504                 default:
505                         net_warn_ratelimited("%s: bad gso type %u.\n",
506                                              dev->name, hdr->hdr.gso_type);
507                         goto frame_err;
508                 }
509 
510                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
511                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
512 
513                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
514                 if (skb_shinfo(skb)->gso_size == 0) {
515                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
516                         goto frame_err;
517                 }
518 
519                 /* Header must be checked, and gso_segs computed. */
520                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
521                 skb_shinfo(skb)->gso_segs = 0;
522         }
523 
524         netif_receive_skb(skb);
525         return;
526 
527 frame_err:
528         dev->stats.rx_frame_errors++;
529         dev_kfree_skb(skb);
530 }
531 
532 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
533 {
534         struct virtnet_info *vi = rq->vq->vdev->priv;
535         struct sk_buff *skb;
536         struct skb_vnet_hdr *hdr;
537         int err;
538 
539         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
540         if (unlikely(!skb))
541                 return -ENOMEM;
542 
543         skb_put(skb, GOOD_PACKET_LEN);
544 
545         hdr = skb_vnet_hdr(skb);
546         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
547 
548         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
549 
550         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
551         if (err < 0)
552                 dev_kfree_skb(skb);
553 
554         return err;
555 }
556 
557 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
558 {
559         struct page *first, *list = NULL;
560         char *p;
561         int i, err, offset;
562 
563         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
564         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
565                 first = get_a_page(rq, gfp);
566                 if (!first) {
567                         if (list)
568                                 give_pages(rq, list);
569                         return -ENOMEM;
570                 }
571                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
572 
573                 /* chain new page in list head to match sg */
574                 first->private = (unsigned long)list;
575                 list = first;
576         }
577 
578         first = get_a_page(rq, gfp);
579         if (!first) {
580                 give_pages(rq, list);
581                 return -ENOMEM;
582         }
583         p = page_address(first);
584 
585         /* rq->sg[0], rq->sg[1] share the same page */
586         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
587         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
588 
589         /* rq->sg[1] for data packet, from offset */
590         offset = sizeof(struct padded_vnet_hdr);
591         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
592 
593         /* chain first in list head */
594         first->private = (unsigned long)list;
595         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
596                                   first, gfp);
597         if (err < 0)
598                 give_pages(rq, first);
599 
600         return err;
601 }
602 
603 static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len)
604 {
605         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
606         unsigned int len;
607 
608         len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len),
609                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
610         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
611 }
612 
613 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
614 {
615         struct page_frag *alloc_frag = &rq->alloc_frag;
616         char *buf;
617         unsigned long ctx;
618         int err;
619         unsigned int len, hole;
620 
621         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
622         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
623                 return -ENOMEM;
624 
625         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
626         ctx = mergeable_buf_to_ctx(buf, len);
627         get_page(alloc_frag->page);
628         alloc_frag->offset += len;
629         hole = alloc_frag->size - alloc_frag->offset;
630         if (hole < len) {
631                 /* To avoid internal fragmentation, if there is very likely not
632                  * enough space for another buffer, add the remaining space to
633                  * the current buffer. This extra space is not included in
634                  * the truesize stored in ctx.
635                  */
636                 len += hole;
637                 alloc_frag->offset += hole;
638         }
639 
640         sg_init_one(rq->sg, buf, len);
641         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
642         if (err < 0)
643                 put_page(virt_to_head_page(buf));
644 
645         return err;
646 }
647 
648 /*
649  * Returns false if we couldn't fill entirely (OOM).
650  *
651  * Normally run in the receive path, but can also be run from ndo_open
652  * before we're receiving packets, or from refill_work which is
653  * careful to disable receiving (using napi_disable).
654  */
655 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
656 {
657         struct virtnet_info *vi = rq->vq->vdev->priv;
658         int err;
659         bool oom;
660 
661         gfp |= __GFP_COLD;
662         do {
663                 if (vi->mergeable_rx_bufs)
664                         err = add_recvbuf_mergeable(rq, gfp);
665                 else if (vi->big_packets)
666                         err = add_recvbuf_big(rq, gfp);
667                 else
668                         err = add_recvbuf_small(rq, gfp);
669 
670                 oom = err == -ENOMEM;
671                 if (err)
672                         break;
673         } while (rq->vq->num_free);
674         virtqueue_kick(rq->vq);
675         return !oom;
676 }
677 
678 static void skb_recv_done(struct virtqueue *rvq)
679 {
680         struct virtnet_info *vi = rvq->vdev->priv;
681         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
682 
683         /* Schedule NAPI, Suppress further interrupts if successful. */
684         if (napi_schedule_prep(&rq->napi)) {
685                 virtqueue_disable_cb(rvq);
686                 __napi_schedule(&rq->napi);
687         }
688 }
689 
690 static void virtnet_napi_enable(struct receive_queue *rq)
691 {
692         napi_enable(&rq->napi);
693 
694         /* If all buffers were filled by other side before we napi_enabled, we
695          * won't get another interrupt, so process any outstanding packets
696          * now.  virtnet_poll wants re-enable the queue, so we disable here.
697          * We synchronize against interrupts via NAPI_STATE_SCHED */
698         if (napi_schedule_prep(&rq->napi)) {
699                 virtqueue_disable_cb(rq->vq);
700                 local_bh_disable();
701                 __napi_schedule(&rq->napi);
702                 local_bh_enable();
703         }
704 }
705 
706 static void refill_work(struct work_struct *work)
707 {
708         struct virtnet_info *vi =
709                 container_of(work, struct virtnet_info, refill.work);
710         bool still_empty;
711         int i;
712 
713         for (i = 0; i < vi->curr_queue_pairs; i++) {
714                 struct receive_queue *rq = &vi->rq[i];
715 
716                 napi_disable(&rq->napi);
717                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
718                 virtnet_napi_enable(rq);
719 
720                 /* In theory, this can happen: if we don't get any buffers in
721                  * we will *never* try to fill again.
722                  */
723                 if (still_empty)
724                         schedule_delayed_work(&vi->refill, HZ/2);
725         }
726 }
727 
728 static int virtnet_poll(struct napi_struct *napi, int budget)
729 {
730         struct receive_queue *rq =
731                 container_of(napi, struct receive_queue, napi);
732         struct virtnet_info *vi = rq->vq->vdev->priv;
733         void *buf;
734         unsigned int r, len, received = 0;
735 
736 again:
737         while (received < budget &&
738                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
739                 receive_buf(rq, buf, len);
740                 received++;
741         }
742 
743         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
744                 if (!try_fill_recv(rq, GFP_ATOMIC))
745                         schedule_delayed_work(&vi->refill, 0);
746         }
747 
748         /* Out of packets? */
749         if (received < budget) {
750                 r = virtqueue_enable_cb_prepare(rq->vq);
751                 napi_complete(napi);
752                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
753                     napi_schedule_prep(napi)) {
754                         virtqueue_disable_cb(rq->vq);
755                         __napi_schedule(napi);
756                         goto again;
757                 }
758         }
759 
760         return received;
761 }
762 
763 static int virtnet_open(struct net_device *dev)
764 {
765         struct virtnet_info *vi = netdev_priv(dev);
766         int i;
767 
768         for (i = 0; i < vi->max_queue_pairs; i++) {
769                 if (i < vi->curr_queue_pairs)
770                         /* Make sure we have some buffers: if oom use wq. */
771                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
772                                 schedule_delayed_work(&vi->refill, 0);
773                 virtnet_napi_enable(&vi->rq[i]);
774         }
775 
776         return 0;
777 }
778 
779 static void free_old_xmit_skbs(struct send_queue *sq)
780 {
781         struct sk_buff *skb;
782         unsigned int len;
783         struct virtnet_info *vi = sq->vq->vdev->priv;
784         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
785 
786         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
787                 pr_debug("Sent skb %p\n", skb);
788 
789                 u64_stats_update_begin(&stats->tx_syncp);
790                 stats->tx_bytes += skb->len;
791                 stats->tx_packets++;
792                 u64_stats_update_end(&stats->tx_syncp);
793 
794                 dev_kfree_skb_any(skb);
795         }
796 }
797 
798 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
799 {
800         struct skb_vnet_hdr *hdr;
801         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
802         struct virtnet_info *vi = sq->vq->vdev->priv;
803         unsigned num_sg;
804         unsigned hdr_len;
805         bool can_push;
806 
807         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
808         if (vi->mergeable_rx_bufs)
809                 hdr_len = sizeof hdr->mhdr;
810         else
811                 hdr_len = sizeof hdr->hdr;
812 
813         can_push = vi->any_header_sg &&
814                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
815                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
816         /* Even if we can, don't push here yet as this would skew
817          * csum_start offset below. */
818         if (can_push)
819                 hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
820         else
821                 hdr = skb_vnet_hdr(skb);
822 
823         if (skb->ip_summed == CHECKSUM_PARTIAL) {
824                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
825                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
826                 hdr->hdr.csum_offset = skb->csum_offset;
827         } else {
828                 hdr->hdr.flags = 0;
829                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
830         }
831 
832         if (skb_is_gso(skb)) {
833                 hdr->hdr.hdr_len = skb_headlen(skb);
834                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
835                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
836                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
837                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
838                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
839                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
840                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
841                 else
842                         BUG();
843                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
844                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
845         } else {
846                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
847                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
848         }
849 
850         if (vi->mergeable_rx_bufs)
851                 hdr->mhdr.num_buffers = 0;
852 
853         if (can_push) {
854                 __skb_push(skb, hdr_len);
855                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
856                 /* Pull header back to avoid skew in tx bytes calculations. */
857                 __skb_pull(skb, hdr_len);
858         } else {
859                 sg_set_buf(sq->sg, hdr, hdr_len);
860                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
861         }
862         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
863 }
864 
865 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
866 {
867         struct virtnet_info *vi = netdev_priv(dev);
868         int qnum = skb_get_queue_mapping(skb);
869         struct send_queue *sq = &vi->sq[qnum];
870         int err;
871 
872         /* Free up any pending old buffers before queueing new ones. */
873         free_old_xmit_skbs(sq);
874 
875         /* Try to transmit */
876         err = xmit_skb(sq, skb);
877 
878         /* This should not happen! */
879         if (unlikely(err)) {
880                 dev->stats.tx_fifo_errors++;
881                 if (net_ratelimit())
882                         dev_warn(&dev->dev,
883                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
884                 dev->stats.tx_dropped++;
885                 dev_kfree_skb_any(skb);
886                 return NETDEV_TX_OK;
887         }
888         virtqueue_kick(sq->vq);
889 
890         /* Don't wait up for transmitted skbs to be freed. */
891         skb_orphan(skb);
892         nf_reset(skb);
893 
894         /* Apparently nice girls don't return TX_BUSY; stop the queue
895          * before it gets out of hand.  Naturally, this wastes entries. */
896         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
897                 netif_stop_subqueue(dev, qnum);
898                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
899                         /* More just got used, free them then recheck. */
900                         free_old_xmit_skbs(sq);
901                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
902                                 netif_start_subqueue(dev, qnum);
903                                 virtqueue_disable_cb(sq->vq);
904                         }
905                 }
906         }
907 
908         return NETDEV_TX_OK;
909 }
910 
911 /*
912  * Send command via the control virtqueue and check status.  Commands
913  * supported by the hypervisor, as indicated by feature bits, should
914  * never fail unless improperly formatted.
915  */
916 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
917                                  struct scatterlist *out)
918 {
919         struct scatterlist *sgs[4], hdr, stat;
920         struct virtio_net_ctrl_hdr ctrl;
921         virtio_net_ctrl_ack status = ~0;
922         unsigned out_num = 0, tmp;
923 
924         /* Caller should know better */
925         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
926 
927         ctrl.class = class;
928         ctrl.cmd = cmd;
929         /* Add header */
930         sg_init_one(&hdr, &ctrl, sizeof(ctrl));
931         sgs[out_num++] = &hdr;
932 
933         if (out)
934                 sgs[out_num++] = out;
935 
936         /* Add return status. */
937         sg_init_one(&stat, &status, sizeof(status));
938         sgs[out_num] = &stat;
939 
940         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
941         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
942 
943         if (unlikely(!virtqueue_kick(vi->cvq)))
944                 return status == VIRTIO_NET_OK;
945 
946         /* Spin for a response, the kick causes an ioport write, trapping
947          * into the hypervisor, so the request should be handled immediately.
948          */
949         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
950                !virtqueue_is_broken(vi->cvq))
951                 cpu_relax();
952 
953         return status == VIRTIO_NET_OK;
954 }
955 
956 static int virtnet_set_mac_address(struct net_device *dev, void *p)
957 {
958         struct virtnet_info *vi = netdev_priv(dev);
959         struct virtio_device *vdev = vi->vdev;
960         int ret;
961         struct sockaddr *addr = p;
962         struct scatterlist sg;
963 
964         ret = eth_prepare_mac_addr_change(dev, p);
965         if (ret)
966                 return ret;
967 
968         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
969                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
970                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
971                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
972                         dev_warn(&vdev->dev,
973                                  "Failed to set mac address by vq command.\n");
974                         return -EINVAL;
975                 }
976         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
977                 unsigned int i;
978 
979                 /* Naturally, this has an atomicity problem. */
980                 for (i = 0; i < dev->addr_len; i++)
981                         virtio_cwrite8(vdev,
982                                        offsetof(struct virtio_net_config, mac) +
983                                        i, addr->sa_data[i]);
984         }
985 
986         eth_commit_mac_addr_change(dev, p);
987 
988         return 0;
989 }
990 
991 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
992                                                struct rtnl_link_stats64 *tot)
993 {
994         struct virtnet_info *vi = netdev_priv(dev);
995         int cpu;
996         unsigned int start;
997 
998         for_each_possible_cpu(cpu) {
999                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1000                 u64 tpackets, tbytes, rpackets, rbytes;
1001 
1002                 do {
1003                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1004                         tpackets = stats->tx_packets;
1005                         tbytes   = stats->tx_bytes;
1006                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1007 
1008                 do {
1009                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1010                         rpackets = stats->rx_packets;
1011                         rbytes   = stats->rx_bytes;
1012                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1013 
1014                 tot->rx_packets += rpackets;
1015                 tot->tx_packets += tpackets;
1016                 tot->rx_bytes   += rbytes;
1017                 tot->tx_bytes   += tbytes;
1018         }
1019 
1020         tot->tx_dropped = dev->stats.tx_dropped;
1021         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1022         tot->rx_dropped = dev->stats.rx_dropped;
1023         tot->rx_length_errors = dev->stats.rx_length_errors;
1024         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1025 
1026         return tot;
1027 }
1028 
1029 #ifdef CONFIG_NET_POLL_CONTROLLER
1030 static void virtnet_netpoll(struct net_device *dev)
1031 {
1032         struct virtnet_info *vi = netdev_priv(dev);
1033         int i;
1034 
1035         for (i = 0; i < vi->curr_queue_pairs; i++)
1036                 napi_schedule(&vi->rq[i].napi);
1037 }
1038 #endif
1039 
1040 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1041 {
1042         rtnl_lock();
1043         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1044                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1045                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1046         rtnl_unlock();
1047 }
1048 
1049 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1050 {
1051         struct scatterlist sg;
1052         struct virtio_net_ctrl_mq s;
1053         struct net_device *dev = vi->dev;
1054 
1055         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1056                 return 0;
1057 
1058         s.virtqueue_pairs = queue_pairs;
1059         sg_init_one(&sg, &s, sizeof(s));
1060 
1061         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1062                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1063                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1064                          queue_pairs);
1065                 return -EINVAL;
1066         } else {
1067                 vi->curr_queue_pairs = queue_pairs;
1068                 /* virtnet_open() will refill when device is going to up. */
1069                 if (dev->flags & IFF_UP)
1070                         schedule_delayed_work(&vi->refill, 0);
1071         }
1072 
1073         return 0;
1074 }
1075 
1076 static int virtnet_close(struct net_device *dev)
1077 {
1078         struct virtnet_info *vi = netdev_priv(dev);
1079         int i;
1080 
1081         /* Make sure refill_work doesn't re-enable napi! */
1082         cancel_delayed_work_sync(&vi->refill);
1083 
1084         for (i = 0; i < vi->max_queue_pairs; i++)
1085                 napi_disable(&vi->rq[i].napi);
1086 
1087         return 0;
1088 }
1089 
1090 static void virtnet_set_rx_mode(struct net_device *dev)
1091 {
1092         struct virtnet_info *vi = netdev_priv(dev);
1093         struct scatterlist sg[2];
1094         u8 promisc, allmulti;
1095         struct virtio_net_ctrl_mac *mac_data;
1096         struct netdev_hw_addr *ha;
1097         int uc_count;
1098         int mc_count;
1099         void *buf;
1100         int i;
1101 
1102         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1103         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1104                 return;
1105 
1106         promisc = ((dev->flags & IFF_PROMISC) != 0);
1107         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1108 
1109         sg_init_one(sg, &promisc, sizeof(promisc));
1110 
1111         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1112                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1113                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1114                          promisc ? "en" : "dis");
1115 
1116         sg_init_one(sg, &allmulti, sizeof(allmulti));
1117 
1118         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1119                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1120                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1121                          allmulti ? "en" : "dis");
1122 
1123         uc_count = netdev_uc_count(dev);
1124         mc_count = netdev_mc_count(dev);
1125         /* MAC filter - use one buffer for both lists */
1126         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1127                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1128         mac_data = buf;
1129         if (!buf)
1130                 return;
1131 
1132         sg_init_table(sg, 2);
1133 
1134         /* Store the unicast list and count in the front of the buffer */
1135         mac_data->entries = uc_count;
1136         i = 0;
1137         netdev_for_each_uc_addr(ha, dev)
1138                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1139 
1140         sg_set_buf(&sg[0], mac_data,
1141                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1142 
1143         /* multicast list and count fill the end */
1144         mac_data = (void *)&mac_data->macs[uc_count][0];
1145 
1146         mac_data->entries = mc_count;
1147         i = 0;
1148         netdev_for_each_mc_addr(ha, dev)
1149                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1150 
1151         sg_set_buf(&sg[1], mac_data,
1152                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1153 
1154         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1155                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1156                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1157 
1158         kfree(buf);
1159 }
1160 
1161 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1162                                    __be16 proto, u16 vid)
1163 {
1164         struct virtnet_info *vi = netdev_priv(dev);
1165         struct scatterlist sg;
1166 
1167         sg_init_one(&sg, &vid, sizeof(vid));
1168 
1169         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1170                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1171                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1172         return 0;
1173 }
1174 
1175 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1176                                     __be16 proto, u16 vid)
1177 {
1178         struct virtnet_info *vi = netdev_priv(dev);
1179         struct scatterlist sg;
1180 
1181         sg_init_one(&sg, &vid, sizeof(vid));
1182 
1183         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1184                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1185                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1186         return 0;
1187 }
1188 
1189 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1190 {
1191         int i;
1192 
1193         if (vi->affinity_hint_set) {
1194                 for (i = 0; i < vi->max_queue_pairs; i++) {
1195                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1196                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1197                 }
1198 
1199                 vi->affinity_hint_set = false;
1200         }
1201 }
1202 
1203 static void virtnet_set_affinity(struct virtnet_info *vi)
1204 {
1205         int i;
1206         int cpu;
1207 
1208         /* In multiqueue mode, when the number of cpu is equal to the number of
1209          * queue pairs, we let the queue pairs to be private to one cpu by
1210          * setting the affinity hint to eliminate the contention.
1211          */
1212         if (vi->curr_queue_pairs == 1 ||
1213             vi->max_queue_pairs != num_online_cpus()) {
1214                 virtnet_clean_affinity(vi, -1);
1215                 return;
1216         }
1217 
1218         i = 0;
1219         for_each_online_cpu(cpu) {
1220                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1221                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1222                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1223                 i++;
1224         }
1225 
1226         vi->affinity_hint_set = true;
1227 }
1228 
1229 static int virtnet_cpu_callback(struct notifier_block *nfb,
1230                                 unsigned long action, void *hcpu)
1231 {
1232         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1233 
1234         switch(action & ~CPU_TASKS_FROZEN) {
1235         case CPU_ONLINE:
1236         case CPU_DOWN_FAILED:
1237         case CPU_DEAD:
1238                 virtnet_set_affinity(vi);
1239                 break;
1240         case CPU_DOWN_PREPARE:
1241                 virtnet_clean_affinity(vi, (long)hcpu);
1242                 break;
1243         default:
1244                 break;
1245         }
1246 
1247         return NOTIFY_OK;
1248 }
1249 
1250 static void virtnet_get_ringparam(struct net_device *dev,
1251                                 struct ethtool_ringparam *ring)
1252 {
1253         struct virtnet_info *vi = netdev_priv(dev);
1254 
1255         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1256         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1257         ring->rx_pending = ring->rx_max_pending;
1258         ring->tx_pending = ring->tx_max_pending;
1259 }
1260 
1261 
1262 static void virtnet_get_drvinfo(struct net_device *dev,
1263                                 struct ethtool_drvinfo *info)
1264 {
1265         struct virtnet_info *vi = netdev_priv(dev);
1266         struct virtio_device *vdev = vi->vdev;
1267 
1268         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1269         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1270         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1271 
1272 }
1273 
1274 /* TODO: Eliminate OOO packets during switching */
1275 static int virtnet_set_channels(struct net_device *dev,
1276                                 struct ethtool_channels *channels)
1277 {
1278         struct virtnet_info *vi = netdev_priv(dev);
1279         u16 queue_pairs = channels->combined_count;
1280         int err;
1281 
1282         /* We don't support separate rx/tx channels.
1283          * We don't allow setting 'other' channels.
1284          */
1285         if (channels->rx_count || channels->tx_count || channels->other_count)
1286                 return -EINVAL;
1287 
1288         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1289                 return -EINVAL;
1290 
1291         get_online_cpus();
1292         err = virtnet_set_queues(vi, queue_pairs);
1293         if (!err) {
1294                 netif_set_real_num_tx_queues(dev, queue_pairs);
1295                 netif_set_real_num_rx_queues(dev, queue_pairs);
1296 
1297                 virtnet_set_affinity(vi);
1298         }
1299         put_online_cpus();
1300 
1301         return err;
1302 }
1303 
1304 static void virtnet_get_channels(struct net_device *dev,
1305                                  struct ethtool_channels *channels)
1306 {
1307         struct virtnet_info *vi = netdev_priv(dev);
1308 
1309         channels->combined_count = vi->curr_queue_pairs;
1310         channels->max_combined = vi->max_queue_pairs;
1311         channels->max_other = 0;
1312         channels->rx_count = 0;
1313         channels->tx_count = 0;
1314         channels->other_count = 0;
1315 }
1316 
1317 static const struct ethtool_ops virtnet_ethtool_ops = {
1318         .get_drvinfo = virtnet_get_drvinfo,
1319         .get_link = ethtool_op_get_link,
1320         .get_ringparam = virtnet_get_ringparam,
1321         .set_channels = virtnet_set_channels,
1322         .get_channels = virtnet_get_channels,
1323 };
1324 
1325 #define MIN_MTU 68
1326 #define MAX_MTU 65535
1327 
1328 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1329 {
1330         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1331                 return -EINVAL;
1332         dev->mtu = new_mtu;
1333         return 0;
1334 }
1335 
1336 static const struct net_device_ops virtnet_netdev = {
1337         .ndo_open            = virtnet_open,
1338         .ndo_stop            = virtnet_close,
1339         .ndo_start_xmit      = start_xmit,
1340         .ndo_validate_addr   = eth_validate_addr,
1341         .ndo_set_mac_address = virtnet_set_mac_address,
1342         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1343         .ndo_change_mtu      = virtnet_change_mtu,
1344         .ndo_get_stats64     = virtnet_stats,
1345         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1346         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1347 #ifdef CONFIG_NET_POLL_CONTROLLER
1348         .ndo_poll_controller = virtnet_netpoll,
1349 #endif
1350 };
1351 
1352 static void virtnet_config_changed_work(struct work_struct *work)
1353 {
1354         struct virtnet_info *vi =
1355                 container_of(work, struct virtnet_info, config_work);
1356         u16 v;
1357 
1358         mutex_lock(&vi->config_lock);
1359         if (!vi->config_enable)
1360                 goto done;
1361 
1362         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1363                                  struct virtio_net_config, status, &v) < 0)
1364                 goto done;
1365 
1366         if (v & VIRTIO_NET_S_ANNOUNCE) {
1367                 netdev_notify_peers(vi->dev);
1368                 virtnet_ack_link_announce(vi);
1369         }
1370 
1371         /* Ignore unknown (future) status bits */
1372         v &= VIRTIO_NET_S_LINK_UP;
1373 
1374         if (vi->status == v)
1375                 goto done;
1376 
1377         vi->status = v;
1378 
1379         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1380                 netif_carrier_on(vi->dev);
1381                 netif_tx_wake_all_queues(vi->dev);
1382         } else {
1383                 netif_carrier_off(vi->dev);
1384                 netif_tx_stop_all_queues(vi->dev);
1385         }
1386 done:
1387         mutex_unlock(&vi->config_lock);
1388 }
1389 
1390 static void virtnet_config_changed(struct virtio_device *vdev)
1391 {
1392         struct virtnet_info *vi = vdev->priv;
1393 
1394         schedule_work(&vi->config_work);
1395 }
1396 
1397 static void virtnet_free_queues(struct virtnet_info *vi)
1398 {
1399         int i;
1400 
1401         for (i = 0; i < vi->max_queue_pairs; i++)
1402                 netif_napi_del(&vi->rq[i].napi);
1403 
1404         kfree(vi->rq);
1405         kfree(vi->sq);
1406 }
1407 
1408 static void free_receive_bufs(struct virtnet_info *vi)
1409 {
1410         int i;
1411 
1412         for (i = 0; i < vi->max_queue_pairs; i++) {
1413                 while (vi->rq[i].pages)
1414                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1415         }
1416 }
1417 
1418 static void free_receive_page_frags(struct virtnet_info *vi)
1419 {
1420         int i;
1421         for (i = 0; i < vi->max_queue_pairs; i++)
1422                 if (vi->rq[i].alloc_frag.page)
1423                         put_page(vi->rq[i].alloc_frag.page);
1424 }
1425 
1426 static void free_unused_bufs(struct virtnet_info *vi)
1427 {
1428         void *buf;
1429         int i;
1430 
1431         for (i = 0; i < vi->max_queue_pairs; i++) {
1432                 struct virtqueue *vq = vi->sq[i].vq;
1433                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1434                         dev_kfree_skb(buf);
1435         }
1436 
1437         for (i = 0; i < vi->max_queue_pairs; i++) {
1438                 struct virtqueue *vq = vi->rq[i].vq;
1439 
1440                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1441                         if (vi->mergeable_rx_bufs) {
1442                                 unsigned long ctx = (unsigned long)buf;
1443                                 void *base = mergeable_ctx_to_buf_address(ctx);
1444                                 put_page(virt_to_head_page(base));
1445                         } else if (vi->big_packets) {
1446                                 give_pages(&vi->rq[i], buf);
1447                         } else {
1448                                 dev_kfree_skb(buf);
1449                         }
1450                 }
1451         }
1452 }
1453 
1454 static void virtnet_del_vqs(struct virtnet_info *vi)
1455 {
1456         struct virtio_device *vdev = vi->vdev;
1457 
1458         virtnet_clean_affinity(vi, -1);
1459 
1460         vdev->config->del_vqs(vdev);
1461 
1462         virtnet_free_queues(vi);
1463 }
1464 
1465 static int virtnet_find_vqs(struct virtnet_info *vi)
1466 {
1467         vq_callback_t **callbacks;
1468         struct virtqueue **vqs;
1469         int ret = -ENOMEM;
1470         int i, total_vqs;
1471         const char **names;
1472 
1473         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1474          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1475          * possible control vq.
1476          */
1477         total_vqs = vi->max_queue_pairs * 2 +
1478                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1479 
1480         /* Allocate space for find_vqs parameters */
1481         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1482         if (!vqs)
1483                 goto err_vq;
1484         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1485         if (!callbacks)
1486                 goto err_callback;
1487         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1488         if (!names)
1489                 goto err_names;
1490 
1491         /* Parameters for control virtqueue, if any */
1492         if (vi->has_cvq) {
1493                 callbacks[total_vqs - 1] = NULL;
1494                 names[total_vqs - 1] = "control";
1495         }
1496 
1497         /* Allocate/initialize parameters for send/receive virtqueues */
1498         for (i = 0; i < vi->max_queue_pairs; i++) {
1499                 callbacks[rxq2vq(i)] = skb_recv_done;
1500                 callbacks[txq2vq(i)] = skb_xmit_done;
1501                 sprintf(vi->rq[i].name, "input.%d", i);
1502                 sprintf(vi->sq[i].name, "output.%d", i);
1503                 names[rxq2vq(i)] = vi->rq[i].name;
1504                 names[txq2vq(i)] = vi->sq[i].name;
1505         }
1506 
1507         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1508                                          names);
1509         if (ret)
1510                 goto err_find;
1511 
1512         if (vi->has_cvq) {
1513                 vi->cvq = vqs[total_vqs - 1];
1514                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1515                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1516         }
1517 
1518         for (i = 0; i < vi->max_queue_pairs; i++) {
1519                 vi->rq[i].vq = vqs[rxq2vq(i)];
1520                 vi->sq[i].vq = vqs[txq2vq(i)];
1521         }
1522 
1523         kfree(names);
1524         kfree(callbacks);
1525         kfree(vqs);
1526 
1527         return 0;
1528 
1529 err_find:
1530         kfree(names);
1531 err_names:
1532         kfree(callbacks);
1533 err_callback:
1534         kfree(vqs);
1535 err_vq:
1536         return ret;
1537 }
1538 
1539 static int virtnet_alloc_queues(struct virtnet_info *vi)
1540 {
1541         int i;
1542 
1543         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1544         if (!vi->sq)
1545                 goto err_sq;
1546         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1547         if (!vi->rq)
1548                 goto err_rq;
1549 
1550         INIT_DELAYED_WORK(&vi->refill, refill_work);
1551         for (i = 0; i < vi->max_queue_pairs; i++) {
1552                 vi->rq[i].pages = NULL;
1553                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1554                                napi_weight);
1555 
1556                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1557                 ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT);
1558                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1559         }
1560 
1561         return 0;
1562 
1563 err_rq:
1564         kfree(vi->sq);
1565 err_sq:
1566         return -ENOMEM;
1567 }
1568 
1569 static int init_vqs(struct virtnet_info *vi)
1570 {
1571         int ret;
1572 
1573         /* Allocate send & receive queues */
1574         ret = virtnet_alloc_queues(vi);
1575         if (ret)
1576                 goto err;
1577 
1578         ret = virtnet_find_vqs(vi);
1579         if (ret)
1580                 goto err_free;
1581 
1582         get_online_cpus();
1583         virtnet_set_affinity(vi);
1584         put_online_cpus();
1585 
1586         return 0;
1587 
1588 err_free:
1589         virtnet_free_queues(vi);
1590 err:
1591         return ret;
1592 }
1593 
1594 #ifdef CONFIG_SYSFS
1595 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1596                 struct rx_queue_attribute *attribute, char *buf)
1597 {
1598         struct virtnet_info *vi = netdev_priv(queue->dev);
1599         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1600         struct ewma *avg;
1601 
1602         BUG_ON(queue_index >= vi->max_queue_pairs);
1603         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1604         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1605 }
1606 
1607 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1608         __ATTR_RO(mergeable_rx_buffer_size);
1609 
1610 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1611         &mergeable_rx_buffer_size_attribute.attr,
1612         NULL
1613 };
1614 
1615 static const struct attribute_group virtio_net_mrg_rx_group = {
1616         .name = "virtio_net",
1617         .attrs = virtio_net_mrg_rx_attrs
1618 };
1619 #endif
1620 
1621 static int virtnet_probe(struct virtio_device *vdev)
1622 {
1623         int i, err;
1624         struct net_device *dev;
1625         struct virtnet_info *vi;
1626         u16 max_queue_pairs;
1627 
1628         /* Find if host supports multiqueue virtio_net device */
1629         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1630                                    struct virtio_net_config,
1631                                    max_virtqueue_pairs, &max_queue_pairs);
1632 
1633         /* We need at least 2 queue's */
1634         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1635             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1636             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1637                 max_queue_pairs = 1;
1638 
1639         /* Allocate ourselves a network device with room for our info */
1640         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1641         if (!dev)
1642                 return -ENOMEM;
1643 
1644         /* Set up network device as normal. */
1645         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1646         dev->netdev_ops = &virtnet_netdev;
1647         dev->features = NETIF_F_HIGHDMA;
1648 
1649         dev->ethtool_ops = &virtnet_ethtool_ops;
1650         SET_NETDEV_DEV(dev, &vdev->dev);
1651 
1652         /* Do we support "hardware" checksums? */
1653         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1654                 /* This opens up the world of extra features. */
1655                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1656                 if (csum)
1657                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1658 
1659                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1660                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1661                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1662                 }
1663                 /* Individual feature bits: what can host handle? */
1664                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1665                         dev->hw_features |= NETIF_F_TSO;
1666                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1667                         dev->hw_features |= NETIF_F_TSO6;
1668                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1669                         dev->hw_features |= NETIF_F_TSO_ECN;
1670                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1671                         dev->hw_features |= NETIF_F_UFO;
1672 
1673                 if (gso)
1674                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1675                 /* (!csum && gso) case will be fixed by register_netdev() */
1676         }
1677         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1678                 dev->features |= NETIF_F_RXCSUM;
1679 
1680         dev->vlan_features = dev->features;
1681 
1682         /* Configuration may specify what MAC to use.  Otherwise random. */
1683         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1684                 virtio_cread_bytes(vdev,
1685                                    offsetof(struct virtio_net_config, mac),
1686                                    dev->dev_addr, dev->addr_len);
1687         else
1688                 eth_hw_addr_random(dev);
1689 
1690         /* Set up our device-specific information */
1691         vi = netdev_priv(dev);
1692         vi->dev = dev;
1693         vi->vdev = vdev;
1694         vdev->priv = vi;
1695         vi->stats = alloc_percpu(struct virtnet_stats);
1696         err = -ENOMEM;
1697         if (vi->stats == NULL)
1698                 goto free;
1699 
1700         for_each_possible_cpu(i) {
1701                 struct virtnet_stats *virtnet_stats;
1702                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1703                 u64_stats_init(&virtnet_stats->tx_syncp);
1704                 u64_stats_init(&virtnet_stats->rx_syncp);
1705         }
1706 
1707         mutex_init(&vi->config_lock);
1708         vi->config_enable = true;
1709         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1710 
1711         /* If we can receive ANY GSO packets, we must allocate large ones. */
1712         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1713             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1714             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1715             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1716                 vi->big_packets = true;
1717 
1718         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1719                 vi->mergeable_rx_bufs = true;
1720 
1721         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
1722                 vi->any_header_sg = true;
1723 
1724         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1725                 vi->has_cvq = true;
1726 
1727         if (vi->any_header_sg) {
1728                 if (vi->mergeable_rx_bufs)
1729                         dev->needed_headroom = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1730                 else
1731                         dev->needed_headroom = sizeof(struct virtio_net_hdr);
1732         }
1733 
1734         /* Use single tx/rx queue pair as default */
1735         vi->curr_queue_pairs = 1;
1736         vi->max_queue_pairs = max_queue_pairs;
1737 
1738         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1739         err = init_vqs(vi);
1740         if (err)
1741                 goto free_stats;
1742 
1743 #ifdef CONFIG_SYSFS
1744         if (vi->mergeable_rx_bufs)
1745                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1746 #endif
1747         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1748         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1749 
1750         err = register_netdev(dev);
1751         if (err) {
1752                 pr_debug("virtio_net: registering device failed\n");
1753                 goto free_vqs;
1754         }
1755 
1756         /* Last of all, set up some receive buffers. */
1757         for (i = 0; i < vi->curr_queue_pairs; i++) {
1758                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1759 
1760                 /* If we didn't even get one input buffer, we're useless. */
1761                 if (vi->rq[i].vq->num_free ==
1762                     virtqueue_get_vring_size(vi->rq[i].vq)) {
1763                         free_unused_bufs(vi);
1764                         err = -ENOMEM;
1765                         goto free_recv_bufs;
1766                 }
1767         }
1768 
1769         vi->nb.notifier_call = &virtnet_cpu_callback;
1770         err = register_hotcpu_notifier(&vi->nb);
1771         if (err) {
1772                 pr_debug("virtio_net: registering cpu notifier failed\n");
1773                 goto free_recv_bufs;
1774         }
1775 
1776         /* Assume link up if device can't report link status,
1777            otherwise get link status from config. */
1778         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1779                 netif_carrier_off(dev);
1780                 schedule_work(&vi->config_work);
1781         } else {
1782                 vi->status = VIRTIO_NET_S_LINK_UP;
1783                 netif_carrier_on(dev);
1784         }
1785 
1786         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1787                  dev->name, max_queue_pairs);
1788 
1789         return 0;
1790 
1791 free_recv_bufs:
1792         free_receive_bufs(vi);
1793         unregister_netdev(dev);
1794 free_vqs:
1795         cancel_delayed_work_sync(&vi->refill);
1796         free_receive_page_frags(vi);
1797         virtnet_del_vqs(vi);
1798 free_stats:
1799         free_percpu(vi->stats);
1800 free:
1801         free_netdev(dev);
1802         return err;
1803 }
1804 
1805 static void remove_vq_common(struct virtnet_info *vi)
1806 {
1807         vi->vdev->config->reset(vi->vdev);
1808 
1809         /* Free unused buffers in both send and recv, if any. */
1810         free_unused_bufs(vi);
1811 
1812         free_receive_bufs(vi);
1813 
1814         free_receive_page_frags(vi);
1815 
1816         virtnet_del_vqs(vi);
1817 }
1818 
1819 static void virtnet_remove(struct virtio_device *vdev)
1820 {
1821         struct virtnet_info *vi = vdev->priv;
1822 
1823         unregister_hotcpu_notifier(&vi->nb);
1824 
1825         /* Prevent config work handler from accessing the device. */
1826         mutex_lock(&vi->config_lock);
1827         vi->config_enable = false;
1828         mutex_unlock(&vi->config_lock);
1829 
1830         unregister_netdev(vi->dev);
1831 
1832         remove_vq_common(vi);
1833 
1834         flush_work(&vi->config_work);
1835 
1836         free_percpu(vi->stats);
1837         free_netdev(vi->dev);
1838 }
1839 
1840 #ifdef CONFIG_PM_SLEEP
1841 static int virtnet_freeze(struct virtio_device *vdev)
1842 {
1843         struct virtnet_info *vi = vdev->priv;
1844         int i;
1845 
1846         unregister_hotcpu_notifier(&vi->nb);
1847 
1848         /* Prevent config work handler from accessing the device */
1849         mutex_lock(&vi->config_lock);
1850         vi->config_enable = false;
1851         mutex_unlock(&vi->config_lock);
1852 
1853         netif_device_detach(vi->dev);
1854         cancel_delayed_work_sync(&vi->refill);
1855 
1856         if (netif_running(vi->dev))
1857                 for (i = 0; i < vi->max_queue_pairs; i++) {
1858                         napi_disable(&vi->rq[i].napi);
1859                         netif_napi_del(&vi->rq[i].napi);
1860                 }
1861 
1862         remove_vq_common(vi);
1863 
1864         flush_work(&vi->config_work);
1865 
1866         return 0;
1867 }
1868 
1869 static int virtnet_restore(struct virtio_device *vdev)
1870 {
1871         struct virtnet_info *vi = vdev->priv;
1872         int err, i;
1873 
1874         err = init_vqs(vi);
1875         if (err)
1876                 return err;
1877 
1878         if (netif_running(vi->dev)) {
1879                 for (i = 0; i < vi->curr_queue_pairs; i++)
1880                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1881                                 schedule_delayed_work(&vi->refill, 0);
1882 
1883                 for (i = 0; i < vi->max_queue_pairs; i++)
1884                         virtnet_napi_enable(&vi->rq[i]);
1885         }
1886 
1887         netif_device_attach(vi->dev);
1888 
1889         mutex_lock(&vi->config_lock);
1890         vi->config_enable = true;
1891         mutex_unlock(&vi->config_lock);
1892 
1893         rtnl_lock();
1894         virtnet_set_queues(vi, vi->curr_queue_pairs);
1895         rtnl_unlock();
1896 
1897         err = register_hotcpu_notifier(&vi->nb);
1898         if (err)
1899                 return err;
1900 
1901         return 0;
1902 }
1903 #endif
1904 
1905 static struct virtio_device_id id_table[] = {
1906         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1907         { 0 },
1908 };
1909 
1910 static unsigned int features[] = {
1911         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1912         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1913         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1914         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1915         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1916         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1917         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1918         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1919         VIRTIO_NET_F_CTRL_MAC_ADDR,
1920         VIRTIO_F_ANY_LAYOUT,
1921 };
1922 
1923 static struct virtio_driver virtio_net_driver = {
1924         .feature_table = features,
1925         .feature_table_size = ARRAY_SIZE(features),
1926         .driver.name =  KBUILD_MODNAME,
1927         .driver.owner = THIS_MODULE,
1928         .id_table =     id_table,
1929         .probe =        virtnet_probe,
1930         .remove =       virtnet_remove,
1931         .config_changed = virtnet_config_changed,
1932 #ifdef CONFIG_PM_SLEEP
1933         .freeze =       virtnet_freeze,
1934         .restore =      virtnet_restore,
1935 #endif
1936 };
1937 
1938 module_virtio_driver(virtio_net_driver);
1939 
1940 MODULE_DEVICE_TABLE(virtio, id_table);
1941 MODULE_DESCRIPTION("Virtio network driver");
1942 MODULE_LICENSE("GPL");
1943 

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