virtio-net: do not reset during XDP set
[sfrench/cifs-2.6.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, 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/bpf.h>
26 #include <linux/bpf_trace.h>
27 #include <linux/scatterlist.h>
28 #include <linux/if_vlan.h>
29 #include <linux/slab.h>
30 #include <linux/cpu.h>
31 #include <linux/average.h>
32 #include <net/route.h>
33
34 static int napi_weight = NAPI_POLL_WEIGHT;
35 module_param(napi_weight, int, 0444);
36
37 static bool csum = true, gso = true, napi_tx;
38 module_param(csum, bool, 0444);
39 module_param(gso, bool, 0444);
40 module_param(napi_tx, bool, 0644);
41
42 /* FIXME: MTU in config. */
43 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
44 #define GOOD_COPY_LEN   128
45
46 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
47
48 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
49 #define VIRTIO_XDP_HEADROOM 256
50
51 /* RX packet size EWMA. The average packet size is used to determine the packet
52  * buffer size when refilling RX rings. As the entire RX ring may be refilled
53  * at once, the weight is chosen so that the EWMA will be insensitive to short-
54  * term, transient changes in packet size.
55  */
56 DECLARE_EWMA(pkt_len, 0, 64)
57
58 #define VIRTNET_DRIVER_VERSION "1.0.0"
59
60 struct virtnet_stats {
61         struct u64_stats_sync tx_syncp;
62         struct u64_stats_sync rx_syncp;
63         u64 tx_bytes;
64         u64 tx_packets;
65
66         u64 rx_bytes;
67         u64 rx_packets;
68 };
69
70 /* Internal representation of a send virtqueue */
71 struct send_queue {
72         /* Virtqueue associated with this send _queue */
73         struct virtqueue *vq;
74
75         /* TX: fragments + linear part + virtio header */
76         struct scatterlist sg[MAX_SKB_FRAGS + 2];
77
78         /* Name of the send queue: output.$index */
79         char name[40];
80
81         struct napi_struct napi;
82 };
83
84 /* Internal representation of a receive virtqueue */
85 struct receive_queue {
86         /* Virtqueue associated with this receive_queue */
87         struct virtqueue *vq;
88
89         struct napi_struct napi;
90
91         struct bpf_prog __rcu *xdp_prog;
92
93         /* Chain pages by the private ptr. */
94         struct page *pages;
95
96         /* Average packet length for mergeable receive buffers. */
97         struct ewma_pkt_len mrg_avg_pkt_len;
98
99         /* Page frag for packet buffer allocation. */
100         struct page_frag alloc_frag;
101
102         /* RX: fragments + linear part + virtio header */
103         struct scatterlist sg[MAX_SKB_FRAGS + 2];
104
105         /* Min single buffer size for mergeable buffers case. */
106         unsigned int min_buf_len;
107
108         /* Name of this receive queue: input.$index */
109         char name[40];
110 };
111
112 struct virtnet_info {
113         struct virtio_device *vdev;
114         struct virtqueue *cvq;
115         struct net_device *dev;
116         struct send_queue *sq;
117         struct receive_queue *rq;
118         unsigned int status;
119
120         /* Max # of queue pairs supported by the device */
121         u16 max_queue_pairs;
122
123         /* # of queue pairs currently used by the driver */
124         u16 curr_queue_pairs;
125
126         /* # of XDP queue pairs currently used by the driver */
127         u16 xdp_queue_pairs;
128
129         /* I like... big packets and I cannot lie! */
130         bool big_packets;
131
132         /* Host will merge rx buffers for big packets (shake it! shake it!) */
133         bool mergeable_rx_bufs;
134
135         /* Has control virtqueue */
136         bool has_cvq;
137
138         /* Host can handle any s/g split between our header and packet data */
139         bool any_header_sg;
140
141         /* Packet virtio header size */
142         u8 hdr_len;
143
144         /* Active statistics */
145         struct virtnet_stats __percpu *stats;
146
147         /* Work struct for refilling if we run low on memory. */
148         struct delayed_work refill;
149
150         /* Work struct for config space updates */
151         struct work_struct config_work;
152
153         /* Does the affinity hint is set for virtqueues? */
154         bool affinity_hint_set;
155
156         /* CPU hotplug instances for online & dead */
157         struct hlist_node node;
158         struct hlist_node node_dead;
159
160         /* Control VQ buffers: protected by the rtnl lock */
161         struct virtio_net_ctrl_hdr ctrl_hdr;
162         virtio_net_ctrl_ack ctrl_status;
163         struct virtio_net_ctrl_mq ctrl_mq;
164         u8 ctrl_promisc;
165         u8 ctrl_allmulti;
166         u16 ctrl_vid;
167
168         /* Ethtool settings */
169         u8 duplex;
170         u32 speed;
171 };
172
173 struct padded_vnet_hdr {
174         struct virtio_net_hdr_mrg_rxbuf hdr;
175         /*
176          * hdr is in a separate sg buffer, and data sg buffer shares same page
177          * with this header sg. This padding makes next sg 16 byte aligned
178          * after the header.
179          */
180         char padding[4];
181 };
182
183 /* Converting between virtqueue no. and kernel tx/rx queue no.
184  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
185  */
186 static int vq2txq(struct virtqueue *vq)
187 {
188         return (vq->index - 1) / 2;
189 }
190
191 static int txq2vq(int txq)
192 {
193         return txq * 2 + 1;
194 }
195
196 static int vq2rxq(struct virtqueue *vq)
197 {
198         return vq->index / 2;
199 }
200
201 static int rxq2vq(int rxq)
202 {
203         return rxq * 2;
204 }
205
206 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
207 {
208         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
209 }
210
211 /*
212  * private is used to chain pages for big packets, put the whole
213  * most recent used list in the beginning for reuse
214  */
215 static void give_pages(struct receive_queue *rq, struct page *page)
216 {
217         struct page *end;
218
219         /* Find end of list, sew whole thing into vi->rq.pages. */
220         for (end = page; end->private; end = (struct page *)end->private);
221         end->private = (unsigned long)rq->pages;
222         rq->pages = page;
223 }
224
225 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
226 {
227         struct page *p = rq->pages;
228
229         if (p) {
230                 rq->pages = (struct page *)p->private;
231                 /* clear private here, it is used to chain pages */
232                 p->private = 0;
233         } else
234                 p = alloc_page(gfp_mask);
235         return p;
236 }
237
238 static void virtqueue_napi_schedule(struct napi_struct *napi,
239                                     struct virtqueue *vq)
240 {
241         if (napi_schedule_prep(napi)) {
242                 virtqueue_disable_cb(vq);
243                 __napi_schedule(napi);
244         }
245 }
246
247 static void virtqueue_napi_complete(struct napi_struct *napi,
248                                     struct virtqueue *vq, int processed)
249 {
250         int opaque;
251
252         opaque = virtqueue_enable_cb_prepare(vq);
253         if (napi_complete_done(napi, processed) &&
254             unlikely(virtqueue_poll(vq, opaque)))
255                 virtqueue_napi_schedule(napi, vq);
256 }
257
258 static void skb_xmit_done(struct virtqueue *vq)
259 {
260         struct virtnet_info *vi = vq->vdev->priv;
261         struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
262
263         /* Suppress further interrupts. */
264         virtqueue_disable_cb(vq);
265
266         if (napi->weight)
267                 virtqueue_napi_schedule(napi, vq);
268         else
269                 /* We were probably waiting for more output buffers. */
270                 netif_wake_subqueue(vi->dev, vq2txq(vq));
271 }
272
273 #define MRG_CTX_HEADER_SHIFT 22
274 static void *mergeable_len_to_ctx(unsigned int truesize,
275                                   unsigned int headroom)
276 {
277         return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
278 }
279
280 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
281 {
282         return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
283 }
284
285 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
286 {
287         return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
288 }
289
290 /* Called from bottom half context */
291 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
292                                    struct receive_queue *rq,
293                                    struct page *page, unsigned int offset,
294                                    unsigned int len, unsigned int truesize)
295 {
296         struct sk_buff *skb;
297         struct virtio_net_hdr_mrg_rxbuf *hdr;
298         unsigned int copy, hdr_len, hdr_padded_len;
299         char *p;
300
301         p = page_address(page) + offset;
302
303         /* copy small packet so we can reuse these pages for small data */
304         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
305         if (unlikely(!skb))
306                 return NULL;
307
308         hdr = skb_vnet_hdr(skb);
309
310         hdr_len = vi->hdr_len;
311         if (vi->mergeable_rx_bufs)
312                 hdr_padded_len = sizeof *hdr;
313         else
314                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
315
316         memcpy(hdr, p, hdr_len);
317
318         len -= hdr_len;
319         offset += hdr_padded_len;
320         p += hdr_padded_len;
321
322         copy = len;
323         if (copy > skb_tailroom(skb))
324                 copy = skb_tailroom(skb);
325         skb_put_data(skb, p, copy);
326
327         len -= copy;
328         offset += copy;
329
330         if (vi->mergeable_rx_bufs) {
331                 if (len)
332                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
333                 else
334                         put_page(page);
335                 return skb;
336         }
337
338         /*
339          * Verify that we can indeed put this data into a skb.
340          * This is here to handle cases when the device erroneously
341          * tries to receive more than is possible. This is usually
342          * the case of a broken device.
343          */
344         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
345                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
346                 dev_kfree_skb(skb);
347                 return NULL;
348         }
349         BUG_ON(offset >= PAGE_SIZE);
350         while (len) {
351                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
352                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
353                                 frag_size, truesize);
354                 len -= frag_size;
355                 page = (struct page *)page->private;
356                 offset = 0;
357         }
358
359         if (page)
360                 give_pages(rq, page);
361
362         return skb;
363 }
364
365 static bool virtnet_xdp_xmit(struct virtnet_info *vi,
366                              struct receive_queue *rq,
367                              struct xdp_buff *xdp)
368 {
369         struct virtio_net_hdr_mrg_rxbuf *hdr;
370         unsigned int len;
371         struct send_queue *sq;
372         unsigned int qp;
373         void *xdp_sent;
374         int err;
375
376         qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
377         sq = &vi->sq[qp];
378
379         /* Free up any pending old buffers before queueing new ones. */
380         while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) {
381                 struct page *sent_page = virt_to_head_page(xdp_sent);
382
383                 put_page(sent_page);
384         }
385
386         xdp->data -= vi->hdr_len;
387         /* Zero header and leave csum up to XDP layers */
388         hdr = xdp->data;
389         memset(hdr, 0, vi->hdr_len);
390
391         sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data);
392
393         err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp->data, GFP_ATOMIC);
394         if (unlikely(err)) {
395                 struct page *page = virt_to_head_page(xdp->data);
396
397                 put_page(page);
398                 return false;
399         }
400
401         virtqueue_kick(sq->vq);
402         return true;
403 }
404
405 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
406 {
407         return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
408 }
409
410 /* We copy the packet for XDP in the following cases:
411  *
412  * 1) Packet is scattered across multiple rx buffers.
413  * 2) Headroom space is insufficient.
414  *
415  * This is inefficient but it's a temporary condition that
416  * we hit right after XDP is enabled and until queue is refilled
417  * with large buffers with sufficient headroom - so it should affect
418  * at most queue size packets.
419  * Afterwards, the conditions to enable
420  * XDP should preclude the underlying device from sending packets
421  * across multiple buffers (num_buf > 1), and we make sure buffers
422  * have enough headroom.
423  */
424 static struct page *xdp_linearize_page(struct receive_queue *rq,
425                                        u16 *num_buf,
426                                        struct page *p,
427                                        int offset,
428                                        int page_off,
429                                        unsigned int *len)
430 {
431         struct page *page = alloc_page(GFP_ATOMIC);
432
433         if (!page)
434                 return NULL;
435
436         memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
437         page_off += *len;
438
439         while (--*num_buf) {
440                 unsigned int buflen;
441                 void *buf;
442                 int off;
443
444                 buf = virtqueue_get_buf(rq->vq, &buflen);
445                 if (unlikely(!buf))
446                         goto err_buf;
447
448                 p = virt_to_head_page(buf);
449                 off = buf - page_address(p);
450
451                 /* guard against a misconfigured or uncooperative backend that
452                  * is sending packet larger than the MTU.
453                  */
454                 if ((page_off + buflen) > PAGE_SIZE) {
455                         put_page(p);
456                         goto err_buf;
457                 }
458
459                 memcpy(page_address(page) + page_off,
460                        page_address(p) + off, buflen);
461                 page_off += buflen;
462                 put_page(p);
463         }
464
465         /* Headroom does not contribute to packet length */
466         *len = page_off - VIRTIO_XDP_HEADROOM;
467         return page;
468 err_buf:
469         __free_pages(page, 0);
470         return NULL;
471 }
472
473 static struct sk_buff *receive_small(struct net_device *dev,
474                                      struct virtnet_info *vi,
475                                      struct receive_queue *rq,
476                                      void *buf, void *ctx,
477                                      unsigned int len)
478 {
479         struct sk_buff *skb;
480         struct bpf_prog *xdp_prog;
481         unsigned int xdp_headroom = (unsigned long)ctx;
482         unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
483         unsigned int headroom = vi->hdr_len + header_offset;
484         unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
485                               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
486         struct page *page = virt_to_head_page(buf);
487         unsigned int delta = 0;
488         struct page *xdp_page;
489         len -= vi->hdr_len;
490
491         rcu_read_lock();
492         xdp_prog = rcu_dereference(rq->xdp_prog);
493         if (xdp_prog) {
494                 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
495                 struct xdp_buff xdp;
496                 void *orig_data;
497                 u32 act;
498
499                 if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
500                         goto err_xdp;
501
502                 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
503                         int offset = buf - page_address(page) + header_offset;
504                         unsigned int tlen = len + vi->hdr_len;
505                         u16 num_buf = 1;
506
507                         xdp_headroom = virtnet_get_headroom(vi);
508                         header_offset = VIRTNET_RX_PAD + xdp_headroom;
509                         headroom = vi->hdr_len + header_offset;
510                         buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
511                                  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
512                         xdp_page = xdp_linearize_page(rq, &num_buf, page,
513                                                       offset, header_offset,
514                                                       &tlen);
515                         if (!xdp_page)
516                                 goto err_xdp;
517
518                         buf = page_address(xdp_page);
519                         put_page(page);
520                         page = xdp_page;
521                 }
522
523                 xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
524                 xdp.data = xdp.data_hard_start + xdp_headroom;
525                 xdp.data_end = xdp.data + len;
526                 orig_data = xdp.data;
527                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
528
529                 switch (act) {
530                 case XDP_PASS:
531                         /* Recalculate length in case bpf program changed it */
532                         delta = orig_data - xdp.data;
533                         break;
534                 case XDP_TX:
535                         if (unlikely(!virtnet_xdp_xmit(vi, rq, &xdp)))
536                                 trace_xdp_exception(vi->dev, xdp_prog, act);
537                         rcu_read_unlock();
538                         goto xdp_xmit;
539                 default:
540                         bpf_warn_invalid_xdp_action(act);
541                 case XDP_ABORTED:
542                         trace_xdp_exception(vi->dev, xdp_prog, act);
543                 case XDP_DROP:
544                         goto err_xdp;
545                 }
546         }
547         rcu_read_unlock();
548
549         skb = build_skb(buf, buflen);
550         if (!skb) {
551                 put_page(page);
552                 goto err;
553         }
554         skb_reserve(skb, headroom - delta);
555         skb_put(skb, len + delta);
556         if (!delta) {
557                 buf += header_offset;
558                 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
559         } /* keep zeroed vnet hdr since packet was changed by bpf */
560
561 err:
562         return skb;
563
564 err_xdp:
565         rcu_read_unlock();
566         dev->stats.rx_dropped++;
567         put_page(page);
568 xdp_xmit:
569         return NULL;
570 }
571
572 static struct sk_buff *receive_big(struct net_device *dev,
573                                    struct virtnet_info *vi,
574                                    struct receive_queue *rq,
575                                    void *buf,
576                                    unsigned int len)
577 {
578         struct page *page = buf;
579         struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
580
581         if (unlikely(!skb))
582                 goto err;
583
584         return skb;
585
586 err:
587         dev->stats.rx_dropped++;
588         give_pages(rq, page);
589         return NULL;
590 }
591
592 static struct sk_buff *receive_mergeable(struct net_device *dev,
593                                          struct virtnet_info *vi,
594                                          struct receive_queue *rq,
595                                          void *buf,
596                                          void *ctx,
597                                          unsigned int len)
598 {
599         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
600         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
601         struct page *page = virt_to_head_page(buf);
602         int offset = buf - page_address(page);
603         struct sk_buff *head_skb, *curr_skb;
604         struct bpf_prog *xdp_prog;
605         unsigned int truesize;
606         unsigned int headroom = mergeable_ctx_to_headroom(ctx);
607
608         head_skb = NULL;
609
610         rcu_read_lock();
611         xdp_prog = rcu_dereference(rq->xdp_prog);
612         if (xdp_prog) {
613                 struct page *xdp_page;
614                 struct xdp_buff xdp;
615                 void *data;
616                 u32 act;
617
618                 /* This happens when rx buffer size is underestimated */
619                 if (unlikely(num_buf > 1 ||
620                              headroom < virtnet_get_headroom(vi))) {
621                         /* linearize data for XDP */
622                         xdp_page = xdp_linearize_page(rq, &num_buf,
623                                                       page, offset,
624                                                       VIRTIO_XDP_HEADROOM,
625                                                       &len);
626                         if (!xdp_page)
627                                 goto err_xdp;
628                         offset = VIRTIO_XDP_HEADROOM;
629                 } else {
630                         xdp_page = page;
631                 }
632
633                 /* Transient failure which in theory could occur if
634                  * in-flight packets from before XDP was enabled reach
635                  * the receive path after XDP is loaded. In practice I
636                  * was not able to create this condition.
637                  */
638                 if (unlikely(hdr->hdr.gso_type))
639                         goto err_xdp;
640
641                 /* Allow consuming headroom but reserve enough space to push
642                  * the descriptor on if we get an XDP_TX return code.
643                  */
644                 data = page_address(xdp_page) + offset;
645                 xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
646                 xdp.data = data + vi->hdr_len;
647                 xdp.data_end = xdp.data + (len - vi->hdr_len);
648                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
649
650                 switch (act) {
651                 case XDP_PASS:
652                         /* recalculate offset to account for any header
653                          * adjustments. Note other cases do not build an
654                          * skb and avoid using offset
655                          */
656                         offset = xdp.data -
657                                         page_address(xdp_page) - vi->hdr_len;
658
659                         /* We can only create skb based on xdp_page. */
660                         if (unlikely(xdp_page != page)) {
661                                 rcu_read_unlock();
662                                 put_page(page);
663                                 head_skb = page_to_skb(vi, rq, xdp_page,
664                                                        offset, len, PAGE_SIZE);
665                                 ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len);
666                                 return head_skb;
667                         }
668                         break;
669                 case XDP_TX:
670                         if (unlikely(!virtnet_xdp_xmit(vi, rq, &xdp)))
671                                 trace_xdp_exception(vi->dev, xdp_prog, act);
672                         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len);
673                         if (unlikely(xdp_page != page))
674                                 goto err_xdp;
675                         rcu_read_unlock();
676                         goto xdp_xmit;
677                 default:
678                         bpf_warn_invalid_xdp_action(act);
679                 case XDP_ABORTED:
680                         trace_xdp_exception(vi->dev, xdp_prog, act);
681                 case XDP_DROP:
682                         if (unlikely(xdp_page != page))
683                                 __free_pages(xdp_page, 0);
684                         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len);
685                         goto err_xdp;
686                 }
687         }
688         rcu_read_unlock();
689
690         truesize = mergeable_ctx_to_truesize(ctx);
691         if (unlikely(len > truesize)) {
692                 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
693                          dev->name, len, (unsigned long)ctx);
694                 dev->stats.rx_length_errors++;
695                 goto err_skb;
696         }
697
698         head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
699         curr_skb = head_skb;
700
701         if (unlikely(!curr_skb))
702                 goto err_skb;
703         while (--num_buf) {
704                 int num_skb_frags;
705
706                 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
707                 if (unlikely(!ctx)) {
708                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
709                                  dev->name, num_buf,
710                                  virtio16_to_cpu(vi->vdev,
711                                                  hdr->num_buffers));
712                         dev->stats.rx_length_errors++;
713                         goto err_buf;
714                 }
715
716                 page = virt_to_head_page(buf);
717
718                 truesize = mergeable_ctx_to_truesize(ctx);
719                 if (unlikely(len > truesize)) {
720                         pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
721                                  dev->name, len, (unsigned long)ctx);
722                         dev->stats.rx_length_errors++;
723                         goto err_skb;
724                 }
725
726                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
727                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
728                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
729
730                         if (unlikely(!nskb))
731                                 goto err_skb;
732                         if (curr_skb == head_skb)
733                                 skb_shinfo(curr_skb)->frag_list = nskb;
734                         else
735                                 curr_skb->next = nskb;
736                         curr_skb = nskb;
737                         head_skb->truesize += nskb->truesize;
738                         num_skb_frags = 0;
739                 }
740                 if (curr_skb != head_skb) {
741                         head_skb->data_len += len;
742                         head_skb->len += len;
743                         head_skb->truesize += truesize;
744                 }
745                 offset = buf - page_address(page);
746                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
747                         put_page(page);
748                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
749                                              len, truesize);
750                 } else {
751                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
752                                         offset, len, truesize);
753                 }
754         }
755
756         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
757         return head_skb;
758
759 err_xdp:
760         rcu_read_unlock();
761 err_skb:
762         put_page(page);
763         while (--num_buf) {
764                 buf = virtqueue_get_buf(rq->vq, &len);
765                 if (unlikely(!buf)) {
766                         pr_debug("%s: rx error: %d buffers missing\n",
767                                  dev->name, num_buf);
768                         dev->stats.rx_length_errors++;
769                         break;
770                 }
771                 page = virt_to_head_page(buf);
772                 put_page(page);
773         }
774 err_buf:
775         dev->stats.rx_dropped++;
776         dev_kfree_skb(head_skb);
777 xdp_xmit:
778         return NULL;
779 }
780
781 static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
782                        void *buf, unsigned int len, void **ctx)
783 {
784         struct net_device *dev = vi->dev;
785         struct sk_buff *skb;
786         struct virtio_net_hdr_mrg_rxbuf *hdr;
787         int ret;
788
789         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
790                 pr_debug("%s: short packet %i\n", dev->name, len);
791                 dev->stats.rx_length_errors++;
792                 if (vi->mergeable_rx_bufs) {
793                         put_page(virt_to_head_page(buf));
794                 } else if (vi->big_packets) {
795                         give_pages(rq, buf);
796                 } else {
797                         put_page(virt_to_head_page(buf));
798                 }
799                 return 0;
800         }
801
802         if (vi->mergeable_rx_bufs)
803                 skb = receive_mergeable(dev, vi, rq, buf, ctx, len);
804         else if (vi->big_packets)
805                 skb = receive_big(dev, vi, rq, buf, len);
806         else
807                 skb = receive_small(dev, vi, rq, buf, ctx, len);
808
809         if (unlikely(!skb))
810                 return 0;
811
812         hdr = skb_vnet_hdr(skb);
813
814         ret = skb->len;
815
816         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
817                 skb->ip_summed = CHECKSUM_UNNECESSARY;
818
819         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
820                                   virtio_is_little_endian(vi->vdev))) {
821                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
822                                      dev->name, hdr->hdr.gso_type,
823                                      hdr->hdr.gso_size);
824                 goto frame_err;
825         }
826
827         skb->protocol = eth_type_trans(skb, dev);
828         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
829                  ntohs(skb->protocol), skb->len, skb->pkt_type);
830
831         napi_gro_receive(&rq->napi, skb);
832         return ret;
833
834 frame_err:
835         dev->stats.rx_frame_errors++;
836         dev_kfree_skb(skb);
837         return 0;
838 }
839
840 /* Unlike mergeable buffers, all buffers are allocated to the
841  * same size, except for the headroom. For this reason we do
842  * not need to use  mergeable_len_to_ctx here - it is enough
843  * to store the headroom as the context ignoring the truesize.
844  */
845 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
846                              gfp_t gfp)
847 {
848         struct page_frag *alloc_frag = &rq->alloc_frag;
849         char *buf;
850         unsigned int xdp_headroom = virtnet_get_headroom(vi);
851         void *ctx = (void *)(unsigned long)xdp_headroom;
852         int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
853         int err;
854
855         len = SKB_DATA_ALIGN(len) +
856               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
857         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
858                 return -ENOMEM;
859
860         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
861         get_page(alloc_frag->page);
862         alloc_frag->offset += len;
863         sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
864                     vi->hdr_len + GOOD_PACKET_LEN);
865         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
866         if (err < 0)
867                 put_page(virt_to_head_page(buf));
868         return err;
869 }
870
871 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
872                            gfp_t gfp)
873 {
874         struct page *first, *list = NULL;
875         char *p;
876         int i, err, offset;
877
878         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
879
880         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
881         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
882                 first = get_a_page(rq, gfp);
883                 if (!first) {
884                         if (list)
885                                 give_pages(rq, list);
886                         return -ENOMEM;
887                 }
888                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
889
890                 /* chain new page in list head to match sg */
891                 first->private = (unsigned long)list;
892                 list = first;
893         }
894
895         first = get_a_page(rq, gfp);
896         if (!first) {
897                 give_pages(rq, list);
898                 return -ENOMEM;
899         }
900         p = page_address(first);
901
902         /* rq->sg[0], rq->sg[1] share the same page */
903         /* a separated rq->sg[0] for header - required in case !any_header_sg */
904         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
905
906         /* rq->sg[1] for data packet, from offset */
907         offset = sizeof(struct padded_vnet_hdr);
908         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
909
910         /* chain first in list head */
911         first->private = (unsigned long)list;
912         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
913                                   first, gfp);
914         if (err < 0)
915                 give_pages(rq, first);
916
917         return err;
918 }
919
920 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
921                                           struct ewma_pkt_len *avg_pkt_len)
922 {
923         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
924         unsigned int len;
925
926         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
927                                 rq->min_buf_len, PAGE_SIZE - hdr_len);
928         return ALIGN(len, L1_CACHE_BYTES);
929 }
930
931 static int add_recvbuf_mergeable(struct virtnet_info *vi,
932                                  struct receive_queue *rq, gfp_t gfp)
933 {
934         struct page_frag *alloc_frag = &rq->alloc_frag;
935         unsigned int headroom = virtnet_get_headroom(vi);
936         char *buf;
937         void *ctx;
938         int err;
939         unsigned int len, hole;
940
941         len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len);
942         if (unlikely(!skb_page_frag_refill(len + headroom, alloc_frag, gfp)))
943                 return -ENOMEM;
944
945         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
946         buf += headroom; /* advance address leaving hole at front of pkt */
947         ctx = mergeable_len_to_ctx(len, headroom);
948         get_page(alloc_frag->page);
949         alloc_frag->offset += len + headroom;
950         hole = alloc_frag->size - alloc_frag->offset;
951         if (hole < len + headroom) {
952                 /* To avoid internal fragmentation, if there is very likely not
953                  * enough space for another buffer, add the remaining space to
954                  * the current buffer. This extra space is not included in
955                  * the truesize stored in ctx.
956                  */
957                 len += hole;
958                 alloc_frag->offset += hole;
959         }
960
961         sg_init_one(rq->sg, buf, len);
962         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
963         if (err < 0)
964                 put_page(virt_to_head_page(buf));
965
966         return err;
967 }
968
969 /*
970  * Returns false if we couldn't fill entirely (OOM).
971  *
972  * Normally run in the receive path, but can also be run from ndo_open
973  * before we're receiving packets, or from refill_work which is
974  * careful to disable receiving (using napi_disable).
975  */
976 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
977                           gfp_t gfp)
978 {
979         int err;
980         bool oom;
981
982         gfp |= __GFP_COLD;
983         do {
984                 if (vi->mergeable_rx_bufs)
985                         err = add_recvbuf_mergeable(vi, rq, gfp);
986                 else if (vi->big_packets)
987                         err = add_recvbuf_big(vi, rq, gfp);
988                 else
989                         err = add_recvbuf_small(vi, rq, gfp);
990
991                 oom = err == -ENOMEM;
992                 if (err)
993                         break;
994         } while (rq->vq->num_free);
995         virtqueue_kick(rq->vq);
996         return !oom;
997 }
998
999 static void skb_recv_done(struct virtqueue *rvq)
1000 {
1001         struct virtnet_info *vi = rvq->vdev->priv;
1002         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1003
1004         virtqueue_napi_schedule(&rq->napi, rvq);
1005 }
1006
1007 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1008 {
1009         napi_enable(napi);
1010
1011         /* If all buffers were filled by other side before we napi_enabled, we
1012          * won't get another interrupt, so process any outstanding packets now.
1013          * Call local_bh_enable after to trigger softIRQ processing.
1014          */
1015         local_bh_disable();
1016         virtqueue_napi_schedule(napi, vq);
1017         local_bh_enable();
1018 }
1019
1020 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1021                                    struct virtqueue *vq,
1022                                    struct napi_struct *napi)
1023 {
1024         if (!napi->weight)
1025                 return;
1026
1027         /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1028          * enable the feature if this is likely affine with the transmit path.
1029          */
1030         if (!vi->affinity_hint_set) {
1031                 napi->weight = 0;
1032                 return;
1033         }
1034
1035         return virtnet_napi_enable(vq, napi);
1036 }
1037
1038 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1039 {
1040         if (napi->weight)
1041                 napi_disable(napi);
1042 }
1043
1044 static void refill_work(struct work_struct *work)
1045 {
1046         struct virtnet_info *vi =
1047                 container_of(work, struct virtnet_info, refill.work);
1048         bool still_empty;
1049         int i;
1050
1051         for (i = 0; i < vi->curr_queue_pairs; i++) {
1052                 struct receive_queue *rq = &vi->rq[i];
1053
1054                 napi_disable(&rq->napi);
1055                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1056                 virtnet_napi_enable(rq->vq, &rq->napi);
1057
1058                 /* In theory, this can happen: if we don't get any buffers in
1059                  * we will *never* try to fill again.
1060                  */
1061                 if (still_empty)
1062                         schedule_delayed_work(&vi->refill, HZ/2);
1063         }
1064 }
1065
1066 static int virtnet_receive(struct receive_queue *rq, int budget)
1067 {
1068         struct virtnet_info *vi = rq->vq->vdev->priv;
1069         unsigned int len, received = 0, bytes = 0;
1070         void *buf;
1071         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
1072
1073         if (!vi->big_packets || vi->mergeable_rx_bufs) {
1074                 void *ctx;
1075
1076                 while (received < budget &&
1077                        (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1078                         bytes += receive_buf(vi, rq, buf, len, ctx);
1079                         received++;
1080                 }
1081         } else {
1082                 while (received < budget &&
1083                        (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1084                         bytes += receive_buf(vi, rq, buf, len, NULL);
1085                         received++;
1086                 }
1087         }
1088
1089         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
1090                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1091                         schedule_delayed_work(&vi->refill, 0);
1092         }
1093
1094         u64_stats_update_begin(&stats->rx_syncp);
1095         stats->rx_bytes += bytes;
1096         stats->rx_packets += received;
1097         u64_stats_update_end(&stats->rx_syncp);
1098
1099         return received;
1100 }
1101
1102 static void free_old_xmit_skbs(struct send_queue *sq)
1103 {
1104         struct sk_buff *skb;
1105         unsigned int len;
1106         struct virtnet_info *vi = sq->vq->vdev->priv;
1107         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
1108         unsigned int packets = 0;
1109         unsigned int bytes = 0;
1110
1111         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1112                 pr_debug("Sent skb %p\n", skb);
1113
1114                 bytes += skb->len;
1115                 packets++;
1116
1117                 dev_kfree_skb_any(skb);
1118         }
1119
1120         /* Avoid overhead when no packets have been processed
1121          * happens when called speculatively from start_xmit.
1122          */
1123         if (!packets)
1124                 return;
1125
1126         u64_stats_update_begin(&stats->tx_syncp);
1127         stats->tx_bytes += bytes;
1128         stats->tx_packets += packets;
1129         u64_stats_update_end(&stats->tx_syncp);
1130 }
1131
1132 static void virtnet_poll_cleantx(struct receive_queue *rq)
1133 {
1134         struct virtnet_info *vi = rq->vq->vdev->priv;
1135         unsigned int index = vq2rxq(rq->vq);
1136         struct send_queue *sq = &vi->sq[index];
1137         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1138
1139         if (!sq->napi.weight)
1140                 return;
1141
1142         if (__netif_tx_trylock(txq)) {
1143                 free_old_xmit_skbs(sq);
1144                 __netif_tx_unlock(txq);
1145         }
1146
1147         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1148                 netif_tx_wake_queue(txq);
1149 }
1150
1151 static int virtnet_poll(struct napi_struct *napi, int budget)
1152 {
1153         struct receive_queue *rq =
1154                 container_of(napi, struct receive_queue, napi);
1155         unsigned int received;
1156
1157         virtnet_poll_cleantx(rq);
1158
1159         received = virtnet_receive(rq, budget);
1160
1161         /* Out of packets? */
1162         if (received < budget)
1163                 virtqueue_napi_complete(napi, rq->vq, received);
1164
1165         return received;
1166 }
1167
1168 static int virtnet_open(struct net_device *dev)
1169 {
1170         struct virtnet_info *vi = netdev_priv(dev);
1171         int i;
1172
1173         for (i = 0; i < vi->max_queue_pairs; i++) {
1174                 if (i < vi->curr_queue_pairs)
1175                         /* Make sure we have some buffers: if oom use wq. */
1176                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1177                                 schedule_delayed_work(&vi->refill, 0);
1178                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1179                 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1180         }
1181
1182         return 0;
1183 }
1184
1185 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1186 {
1187         struct send_queue *sq = container_of(napi, struct send_queue, napi);
1188         struct virtnet_info *vi = sq->vq->vdev->priv;
1189         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
1190
1191         __netif_tx_lock(txq, raw_smp_processor_id());
1192         free_old_xmit_skbs(sq);
1193         __netif_tx_unlock(txq);
1194
1195         virtqueue_napi_complete(napi, sq->vq, 0);
1196
1197         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1198                 netif_tx_wake_queue(txq);
1199
1200         return 0;
1201 }
1202
1203 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1204 {
1205         struct virtio_net_hdr_mrg_rxbuf *hdr;
1206         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1207         struct virtnet_info *vi = sq->vq->vdev->priv;
1208         int num_sg;
1209         unsigned hdr_len = vi->hdr_len;
1210         bool can_push;
1211
1212         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1213
1214         can_push = vi->any_header_sg &&
1215                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1216                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1217         /* Even if we can, don't push here yet as this would skew
1218          * csum_start offset below. */
1219         if (can_push)
1220                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1221         else
1222                 hdr = skb_vnet_hdr(skb);
1223
1224         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1225                                     virtio_is_little_endian(vi->vdev), false))
1226                 BUG();
1227
1228         if (vi->mergeable_rx_bufs)
1229                 hdr->num_buffers = 0;
1230
1231         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1232         if (can_push) {
1233                 __skb_push(skb, hdr_len);
1234                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1235                 if (unlikely(num_sg < 0))
1236                         return num_sg;
1237                 /* Pull header back to avoid skew in tx bytes calculations. */
1238                 __skb_pull(skb, hdr_len);
1239         } else {
1240                 sg_set_buf(sq->sg, hdr, hdr_len);
1241                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1242                 if (unlikely(num_sg < 0))
1243                         return num_sg;
1244                 num_sg++;
1245         }
1246         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1247 }
1248
1249 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1250 {
1251         struct virtnet_info *vi = netdev_priv(dev);
1252         int qnum = skb_get_queue_mapping(skb);
1253         struct send_queue *sq = &vi->sq[qnum];
1254         int err;
1255         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1256         bool kick = !skb->xmit_more;
1257         bool use_napi = sq->napi.weight;
1258
1259         /* Free up any pending old buffers before queueing new ones. */
1260         free_old_xmit_skbs(sq);
1261
1262         if (use_napi && kick)
1263                 virtqueue_enable_cb_delayed(sq->vq);
1264
1265         /* timestamp packet in software */
1266         skb_tx_timestamp(skb);
1267
1268         /* Try to transmit */
1269         err = xmit_skb(sq, skb);
1270
1271         /* This should not happen! */
1272         if (unlikely(err)) {
1273                 dev->stats.tx_fifo_errors++;
1274                 if (net_ratelimit())
1275                         dev_warn(&dev->dev,
1276                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
1277                 dev->stats.tx_dropped++;
1278                 dev_kfree_skb_any(skb);
1279                 return NETDEV_TX_OK;
1280         }
1281
1282         /* Don't wait up for transmitted skbs to be freed. */
1283         if (!use_napi) {
1284                 skb_orphan(skb);
1285                 nf_reset(skb);
1286         }
1287
1288         /* If running out of space, stop queue to avoid getting packets that we
1289          * are then unable to transmit.
1290          * An alternative would be to force queuing layer to requeue the skb by
1291          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1292          * returned in a normal path of operation: it means that driver is not
1293          * maintaining the TX queue stop/start state properly, and causes
1294          * the stack to do a non-trivial amount of useless work.
1295          * Since most packets only take 1 or 2 ring slots, stopping the queue
1296          * early means 16 slots are typically wasted.
1297          */
1298         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1299                 netif_stop_subqueue(dev, qnum);
1300                 if (!use_napi &&
1301                     unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1302                         /* More just got used, free them then recheck. */
1303                         free_old_xmit_skbs(sq);
1304                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1305                                 netif_start_subqueue(dev, qnum);
1306                                 virtqueue_disable_cb(sq->vq);
1307                         }
1308                 }
1309         }
1310
1311         if (kick || netif_xmit_stopped(txq))
1312                 virtqueue_kick(sq->vq);
1313
1314         return NETDEV_TX_OK;
1315 }
1316
1317 /*
1318  * Send command via the control virtqueue and check status.  Commands
1319  * supported by the hypervisor, as indicated by feature bits, should
1320  * never fail unless improperly formatted.
1321  */
1322 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1323                                  struct scatterlist *out)
1324 {
1325         struct scatterlist *sgs[4], hdr, stat;
1326         unsigned out_num = 0, tmp;
1327
1328         /* Caller should know better */
1329         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1330
1331         vi->ctrl_status = ~0;
1332         vi->ctrl_hdr.class = class;
1333         vi->ctrl_hdr.cmd = cmd;
1334         /* Add header */
1335         sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
1336         sgs[out_num++] = &hdr;
1337
1338         if (out)
1339                 sgs[out_num++] = out;
1340
1341         /* Add return status. */
1342         sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
1343         sgs[out_num] = &stat;
1344
1345         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1346         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1347
1348         if (unlikely(!virtqueue_kick(vi->cvq)))
1349                 return vi->ctrl_status == VIRTIO_NET_OK;
1350
1351         /* Spin for a response, the kick causes an ioport write, trapping
1352          * into the hypervisor, so the request should be handled immediately.
1353          */
1354         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1355                !virtqueue_is_broken(vi->cvq))
1356                 cpu_relax();
1357
1358         return vi->ctrl_status == VIRTIO_NET_OK;
1359 }
1360
1361 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1362 {
1363         struct virtnet_info *vi = netdev_priv(dev);
1364         struct virtio_device *vdev = vi->vdev;
1365         int ret;
1366         struct sockaddr *addr;
1367         struct scatterlist sg;
1368
1369         addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1370         if (!addr)
1371                 return -ENOMEM;
1372
1373         ret = eth_prepare_mac_addr_change(dev, addr);
1374         if (ret)
1375                 goto out;
1376
1377         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1378                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1379                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1380                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1381                         dev_warn(&vdev->dev,
1382                                  "Failed to set mac address by vq command.\n");
1383                         ret = -EINVAL;
1384                         goto out;
1385                 }
1386         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1387                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1388                 unsigned int i;
1389
1390                 /* Naturally, this has an atomicity problem. */
1391                 for (i = 0; i < dev->addr_len; i++)
1392                         virtio_cwrite8(vdev,
1393                                        offsetof(struct virtio_net_config, mac) +
1394                                        i, addr->sa_data[i]);
1395         }
1396
1397         eth_commit_mac_addr_change(dev, p);
1398         ret = 0;
1399
1400 out:
1401         kfree(addr);
1402         return ret;
1403 }
1404
1405 static void virtnet_stats(struct net_device *dev,
1406                           struct rtnl_link_stats64 *tot)
1407 {
1408         struct virtnet_info *vi = netdev_priv(dev);
1409         int cpu;
1410         unsigned int start;
1411
1412         for_each_possible_cpu(cpu) {
1413                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1414                 u64 tpackets, tbytes, rpackets, rbytes;
1415
1416                 do {
1417                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1418                         tpackets = stats->tx_packets;
1419                         tbytes   = stats->tx_bytes;
1420                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1421
1422                 do {
1423                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1424                         rpackets = stats->rx_packets;
1425                         rbytes   = stats->rx_bytes;
1426                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1427
1428                 tot->rx_packets += rpackets;
1429                 tot->tx_packets += tpackets;
1430                 tot->rx_bytes   += rbytes;
1431                 tot->tx_bytes   += tbytes;
1432         }
1433
1434         tot->tx_dropped = dev->stats.tx_dropped;
1435         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1436         tot->rx_dropped = dev->stats.rx_dropped;
1437         tot->rx_length_errors = dev->stats.rx_length_errors;
1438         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1439 }
1440
1441 #ifdef CONFIG_NET_POLL_CONTROLLER
1442 static void virtnet_netpoll(struct net_device *dev)
1443 {
1444         struct virtnet_info *vi = netdev_priv(dev);
1445         int i;
1446
1447         for (i = 0; i < vi->curr_queue_pairs; i++)
1448                 napi_schedule(&vi->rq[i].napi);
1449 }
1450 #endif
1451
1452 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1453 {
1454         rtnl_lock();
1455         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1456                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1457                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1458         rtnl_unlock();
1459 }
1460
1461 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1462 {
1463         struct scatterlist sg;
1464         struct net_device *dev = vi->dev;
1465
1466         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1467                 return 0;
1468
1469         vi->ctrl_mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1470         sg_init_one(&sg, &vi->ctrl_mq, sizeof(vi->ctrl_mq));
1471
1472         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1473                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1474                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1475                          queue_pairs);
1476                 return -EINVAL;
1477         } else {
1478                 vi->curr_queue_pairs = queue_pairs;
1479                 /* virtnet_open() will refill when device is going to up. */
1480                 if (dev->flags & IFF_UP)
1481                         schedule_delayed_work(&vi->refill, 0);
1482         }
1483
1484         return 0;
1485 }
1486
1487 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1488 {
1489         int err;
1490
1491         rtnl_lock();
1492         err = _virtnet_set_queues(vi, queue_pairs);
1493         rtnl_unlock();
1494         return err;
1495 }
1496
1497 static int virtnet_close(struct net_device *dev)
1498 {
1499         struct virtnet_info *vi = netdev_priv(dev);
1500         int i;
1501
1502         /* Make sure refill_work doesn't re-enable napi! */
1503         cancel_delayed_work_sync(&vi->refill);
1504
1505         for (i = 0; i < vi->max_queue_pairs; i++) {
1506                 napi_disable(&vi->rq[i].napi);
1507                 virtnet_napi_tx_disable(&vi->sq[i].napi);
1508         }
1509
1510         return 0;
1511 }
1512
1513 static void virtnet_set_rx_mode(struct net_device *dev)
1514 {
1515         struct virtnet_info *vi = netdev_priv(dev);
1516         struct scatterlist sg[2];
1517         struct virtio_net_ctrl_mac *mac_data;
1518         struct netdev_hw_addr *ha;
1519         int uc_count;
1520         int mc_count;
1521         void *buf;
1522         int i;
1523
1524         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1525         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1526                 return;
1527
1528         vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1529         vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1530
1531         sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1532
1533         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1534                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1535                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1536                          vi->ctrl_promisc ? "en" : "dis");
1537
1538         sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1539
1540         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1541                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1542                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1543                          vi->ctrl_allmulti ? "en" : "dis");
1544
1545         uc_count = netdev_uc_count(dev);
1546         mc_count = netdev_mc_count(dev);
1547         /* MAC filter - use one buffer for both lists */
1548         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1549                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1550         mac_data = buf;
1551         if (!buf)
1552                 return;
1553
1554         sg_init_table(sg, 2);
1555
1556         /* Store the unicast list and count in the front of the buffer */
1557         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1558         i = 0;
1559         netdev_for_each_uc_addr(ha, dev)
1560                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1561
1562         sg_set_buf(&sg[0], mac_data,
1563                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1564
1565         /* multicast list and count fill the end */
1566         mac_data = (void *)&mac_data->macs[uc_count][0];
1567
1568         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1569         i = 0;
1570         netdev_for_each_mc_addr(ha, dev)
1571                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1572
1573         sg_set_buf(&sg[1], mac_data,
1574                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1575
1576         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1577                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1578                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1579
1580         kfree(buf);
1581 }
1582
1583 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1584                                    __be16 proto, u16 vid)
1585 {
1586         struct virtnet_info *vi = netdev_priv(dev);
1587         struct scatterlist sg;
1588
1589         vi->ctrl_vid = vid;
1590         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1591
1592         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1593                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1594                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1595         return 0;
1596 }
1597
1598 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1599                                     __be16 proto, u16 vid)
1600 {
1601         struct virtnet_info *vi = netdev_priv(dev);
1602         struct scatterlist sg;
1603
1604         vi->ctrl_vid = vid;
1605         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1606
1607         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1608                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1609                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1610         return 0;
1611 }
1612
1613 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1614 {
1615         int i;
1616
1617         if (vi->affinity_hint_set) {
1618                 for (i = 0; i < vi->max_queue_pairs; i++) {
1619                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1620                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1621                 }
1622
1623                 vi->affinity_hint_set = false;
1624         }
1625 }
1626
1627 static void virtnet_set_affinity(struct virtnet_info *vi)
1628 {
1629         int i;
1630         int cpu;
1631
1632         /* In multiqueue mode, when the number of cpu is equal to the number of
1633          * queue pairs, we let the queue pairs to be private to one cpu by
1634          * setting the affinity hint to eliminate the contention.
1635          */
1636         if (vi->curr_queue_pairs == 1 ||
1637             vi->max_queue_pairs != num_online_cpus()) {
1638                 virtnet_clean_affinity(vi, -1);
1639                 return;
1640         }
1641
1642         i = 0;
1643         for_each_online_cpu(cpu) {
1644                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1645                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1646                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1647                 i++;
1648         }
1649
1650         vi->affinity_hint_set = true;
1651 }
1652
1653 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1654 {
1655         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1656                                                    node);
1657         virtnet_set_affinity(vi);
1658         return 0;
1659 }
1660
1661 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1662 {
1663         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1664                                                    node_dead);
1665         virtnet_set_affinity(vi);
1666         return 0;
1667 }
1668
1669 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1670 {
1671         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1672                                                    node);
1673
1674         virtnet_clean_affinity(vi, cpu);
1675         return 0;
1676 }
1677
1678 static enum cpuhp_state virtionet_online;
1679
1680 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1681 {
1682         int ret;
1683
1684         ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
1685         if (ret)
1686                 return ret;
1687         ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1688                                                &vi->node_dead);
1689         if (!ret)
1690                 return ret;
1691         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1692         return ret;
1693 }
1694
1695 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
1696 {
1697         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1698         cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1699                                             &vi->node_dead);
1700 }
1701
1702 static void virtnet_get_ringparam(struct net_device *dev,
1703                                 struct ethtool_ringparam *ring)
1704 {
1705         struct virtnet_info *vi = netdev_priv(dev);
1706
1707         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1708         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1709         ring->rx_pending = ring->rx_max_pending;
1710         ring->tx_pending = ring->tx_max_pending;
1711 }
1712
1713
1714 static void virtnet_get_drvinfo(struct net_device *dev,
1715                                 struct ethtool_drvinfo *info)
1716 {
1717         struct virtnet_info *vi = netdev_priv(dev);
1718         struct virtio_device *vdev = vi->vdev;
1719
1720         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1721         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1722         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1723
1724 }
1725
1726 /* TODO: Eliminate OOO packets during switching */
1727 static int virtnet_set_channels(struct net_device *dev,
1728                                 struct ethtool_channels *channels)
1729 {
1730         struct virtnet_info *vi = netdev_priv(dev);
1731         u16 queue_pairs = channels->combined_count;
1732         int err;
1733
1734         /* We don't support separate rx/tx channels.
1735          * We don't allow setting 'other' channels.
1736          */
1737         if (channels->rx_count || channels->tx_count || channels->other_count)
1738                 return -EINVAL;
1739
1740         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1741                 return -EINVAL;
1742
1743         /* For now we don't support modifying channels while XDP is loaded
1744          * also when XDP is loaded all RX queues have XDP programs so we only
1745          * need to check a single RX queue.
1746          */
1747         if (vi->rq[0].xdp_prog)
1748                 return -EINVAL;
1749
1750         get_online_cpus();
1751         err = _virtnet_set_queues(vi, queue_pairs);
1752         if (!err) {
1753                 netif_set_real_num_tx_queues(dev, queue_pairs);
1754                 netif_set_real_num_rx_queues(dev, queue_pairs);
1755
1756                 virtnet_set_affinity(vi);
1757         }
1758         put_online_cpus();
1759
1760         return err;
1761 }
1762
1763 static void virtnet_get_channels(struct net_device *dev,
1764                                  struct ethtool_channels *channels)
1765 {
1766         struct virtnet_info *vi = netdev_priv(dev);
1767
1768         channels->combined_count = vi->curr_queue_pairs;
1769         channels->max_combined = vi->max_queue_pairs;
1770         channels->max_other = 0;
1771         channels->rx_count = 0;
1772         channels->tx_count = 0;
1773         channels->other_count = 0;
1774 }
1775
1776 /* Check if the user is trying to change anything besides speed/duplex */
1777 static bool
1778 virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
1779 {
1780         struct ethtool_link_ksettings diff1 = *cmd;
1781         struct ethtool_link_ksettings diff2 = {};
1782
1783         /* cmd is always set so we need to clear it, validate the port type
1784          * and also without autonegotiation we can ignore advertising
1785          */
1786         diff1.base.speed = 0;
1787         diff2.base.port = PORT_OTHER;
1788         ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
1789         diff1.base.duplex = 0;
1790         diff1.base.cmd = 0;
1791         diff1.base.link_mode_masks_nwords = 0;
1792
1793         return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
1794                 bitmap_empty(diff1.link_modes.supported,
1795                              __ETHTOOL_LINK_MODE_MASK_NBITS) &&
1796                 bitmap_empty(diff1.link_modes.advertising,
1797                              __ETHTOOL_LINK_MODE_MASK_NBITS) &&
1798                 bitmap_empty(diff1.link_modes.lp_advertising,
1799                              __ETHTOOL_LINK_MODE_MASK_NBITS);
1800 }
1801
1802 static int virtnet_set_link_ksettings(struct net_device *dev,
1803                                       const struct ethtool_link_ksettings *cmd)
1804 {
1805         struct virtnet_info *vi = netdev_priv(dev);
1806         u32 speed;
1807
1808         speed = cmd->base.speed;
1809         /* don't allow custom speed and duplex */
1810         if (!ethtool_validate_speed(speed) ||
1811             !ethtool_validate_duplex(cmd->base.duplex) ||
1812             !virtnet_validate_ethtool_cmd(cmd))
1813                 return -EINVAL;
1814         vi->speed = speed;
1815         vi->duplex = cmd->base.duplex;
1816
1817         return 0;
1818 }
1819
1820 static int virtnet_get_link_ksettings(struct net_device *dev,
1821                                       struct ethtool_link_ksettings *cmd)
1822 {
1823         struct virtnet_info *vi = netdev_priv(dev);
1824
1825         cmd->base.speed = vi->speed;
1826         cmd->base.duplex = vi->duplex;
1827         cmd->base.port = PORT_OTHER;
1828
1829         return 0;
1830 }
1831
1832 static void virtnet_init_settings(struct net_device *dev)
1833 {
1834         struct virtnet_info *vi = netdev_priv(dev);
1835
1836         vi->speed = SPEED_UNKNOWN;
1837         vi->duplex = DUPLEX_UNKNOWN;
1838 }
1839
1840 static const struct ethtool_ops virtnet_ethtool_ops = {
1841         .get_drvinfo = virtnet_get_drvinfo,
1842         .get_link = ethtool_op_get_link,
1843         .get_ringparam = virtnet_get_ringparam,
1844         .set_channels = virtnet_set_channels,
1845         .get_channels = virtnet_get_channels,
1846         .get_ts_info = ethtool_op_get_ts_info,
1847         .get_link_ksettings = virtnet_get_link_ksettings,
1848         .set_link_ksettings = virtnet_set_link_ksettings,
1849 };
1850
1851 static void virtnet_freeze_down(struct virtio_device *vdev)
1852 {
1853         struct virtnet_info *vi = vdev->priv;
1854         int i;
1855
1856         /* Make sure no work handler is accessing the device */
1857         flush_work(&vi->config_work);
1858
1859         netif_device_detach(vi->dev);
1860         netif_tx_disable(vi->dev);
1861         cancel_delayed_work_sync(&vi->refill);
1862
1863         if (netif_running(vi->dev)) {
1864                 for (i = 0; i < vi->max_queue_pairs; i++) {
1865                         napi_disable(&vi->rq[i].napi);
1866                         virtnet_napi_tx_disable(&vi->sq[i].napi);
1867                 }
1868         }
1869 }
1870
1871 static int init_vqs(struct virtnet_info *vi);
1872
1873 static int virtnet_restore_up(struct virtio_device *vdev)
1874 {
1875         struct virtnet_info *vi = vdev->priv;
1876         int err, i;
1877
1878         err = init_vqs(vi);
1879         if (err)
1880                 return err;
1881
1882         virtio_device_ready(vdev);
1883
1884         if (netif_running(vi->dev)) {
1885                 for (i = 0; i < vi->curr_queue_pairs; i++)
1886                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1887                                 schedule_delayed_work(&vi->refill, 0);
1888
1889                 for (i = 0; i < vi->max_queue_pairs; i++) {
1890                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1891                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
1892                                                &vi->sq[i].napi);
1893                 }
1894         }
1895
1896         netif_device_attach(vi->dev);
1897         return err;
1898 }
1899
1900 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1901                            struct netlink_ext_ack *extack)
1902 {
1903         unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
1904         struct virtnet_info *vi = netdev_priv(dev);
1905         struct bpf_prog *old_prog;
1906         u16 xdp_qp = 0, curr_qp;
1907         int i, err;
1908
1909         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1910             virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1911             virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
1912             virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO)) {
1913                 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO, disable LRO first");
1914                 return -EOPNOTSUPP;
1915         }
1916
1917         if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
1918                 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
1919                 return -EINVAL;
1920         }
1921
1922         if (dev->mtu > max_sz) {
1923                 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
1924                 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
1925                 return -EINVAL;
1926         }
1927
1928         curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
1929         if (prog)
1930                 xdp_qp = nr_cpu_ids;
1931
1932         /* XDP requires extra queues for XDP_TX */
1933         if (curr_qp + xdp_qp > vi->max_queue_pairs) {
1934                 NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
1935                 netdev_warn(dev, "request %i queues but max is %i\n",
1936                             curr_qp + xdp_qp, vi->max_queue_pairs);
1937                 return -ENOMEM;
1938         }
1939
1940         if (prog) {
1941                 prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
1942                 if (IS_ERR(prog))
1943                         return PTR_ERR(prog);
1944         }
1945
1946         /* Make sure NAPI is not using any XDP TX queues for RX. */
1947         for (i = 0; i < vi->max_queue_pairs; i++)
1948                 napi_disable(&vi->rq[i].napi);
1949
1950         netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
1951         err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
1952         if (err)
1953                 goto err;
1954         vi->xdp_queue_pairs = xdp_qp;
1955
1956         for (i = 0; i < vi->max_queue_pairs; i++) {
1957                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
1958                 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
1959                 if (old_prog)
1960                         bpf_prog_put(old_prog);
1961                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1962         }
1963
1964         return 0;
1965
1966 err:
1967         for (i = 0; i < vi->max_queue_pairs; i++)
1968                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1969         if (prog)
1970                 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
1971         return err;
1972 }
1973
1974 static u32 virtnet_xdp_query(struct net_device *dev)
1975 {
1976         struct virtnet_info *vi = netdev_priv(dev);
1977         const struct bpf_prog *xdp_prog;
1978         int i;
1979
1980         for (i = 0; i < vi->max_queue_pairs; i++) {
1981                 xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
1982                 if (xdp_prog)
1983                         return xdp_prog->aux->id;
1984         }
1985         return 0;
1986 }
1987
1988 static int virtnet_xdp(struct net_device *dev, struct netdev_xdp *xdp)
1989 {
1990         switch (xdp->command) {
1991         case XDP_SETUP_PROG:
1992                 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
1993         case XDP_QUERY_PROG:
1994                 xdp->prog_id = virtnet_xdp_query(dev);
1995                 xdp->prog_attached = !!xdp->prog_id;
1996                 return 0;
1997         default:
1998                 return -EINVAL;
1999         }
2000 }
2001
2002 static const struct net_device_ops virtnet_netdev = {
2003         .ndo_open            = virtnet_open,
2004         .ndo_stop            = virtnet_close,
2005         .ndo_start_xmit      = start_xmit,
2006         .ndo_validate_addr   = eth_validate_addr,
2007         .ndo_set_mac_address = virtnet_set_mac_address,
2008         .ndo_set_rx_mode     = virtnet_set_rx_mode,
2009         .ndo_get_stats64     = virtnet_stats,
2010         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2011         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2012 #ifdef CONFIG_NET_POLL_CONTROLLER
2013         .ndo_poll_controller = virtnet_netpoll,
2014 #endif
2015         .ndo_xdp                = virtnet_xdp,
2016         .ndo_features_check     = passthru_features_check,
2017 };
2018
2019 static void virtnet_config_changed_work(struct work_struct *work)
2020 {
2021         struct virtnet_info *vi =
2022                 container_of(work, struct virtnet_info, config_work);
2023         u16 v;
2024
2025         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2026                                  struct virtio_net_config, status, &v) < 0)
2027                 return;
2028
2029         if (v & VIRTIO_NET_S_ANNOUNCE) {
2030                 netdev_notify_peers(vi->dev);
2031                 virtnet_ack_link_announce(vi);
2032         }
2033
2034         /* Ignore unknown (future) status bits */
2035         v &= VIRTIO_NET_S_LINK_UP;
2036
2037         if (vi->status == v)
2038                 return;
2039
2040         vi->status = v;
2041
2042         if (vi->status & VIRTIO_NET_S_LINK_UP) {
2043                 netif_carrier_on(vi->dev);
2044                 netif_tx_wake_all_queues(vi->dev);
2045         } else {
2046                 netif_carrier_off(vi->dev);
2047                 netif_tx_stop_all_queues(vi->dev);
2048         }
2049 }
2050
2051 static void virtnet_config_changed(struct virtio_device *vdev)
2052 {
2053         struct virtnet_info *vi = vdev->priv;
2054
2055         schedule_work(&vi->config_work);
2056 }
2057
2058 static void virtnet_free_queues(struct virtnet_info *vi)
2059 {
2060         int i;
2061
2062         for (i = 0; i < vi->max_queue_pairs; i++) {
2063                 napi_hash_del(&vi->rq[i].napi);
2064                 netif_napi_del(&vi->rq[i].napi);
2065                 netif_napi_del(&vi->sq[i].napi);
2066         }
2067
2068         /* We called napi_hash_del() before netif_napi_del(),
2069          * we need to respect an RCU grace period before freeing vi->rq
2070          */
2071         synchronize_net();
2072
2073         kfree(vi->rq);
2074         kfree(vi->sq);
2075 }
2076
2077 static void _free_receive_bufs(struct virtnet_info *vi)
2078 {
2079         struct bpf_prog *old_prog;
2080         int i;
2081
2082         for (i = 0; i < vi->max_queue_pairs; i++) {
2083                 while (vi->rq[i].pages)
2084                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2085
2086                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2087                 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2088                 if (old_prog)
2089                         bpf_prog_put(old_prog);
2090         }
2091 }
2092
2093 static void free_receive_bufs(struct virtnet_info *vi)
2094 {
2095         rtnl_lock();
2096         _free_receive_bufs(vi);
2097         rtnl_unlock();
2098 }
2099
2100 static void free_receive_page_frags(struct virtnet_info *vi)
2101 {
2102         int i;
2103         for (i = 0; i < vi->max_queue_pairs; i++)
2104                 if (vi->rq[i].alloc_frag.page)
2105                         put_page(vi->rq[i].alloc_frag.page);
2106 }
2107
2108 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
2109 {
2110         if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
2111                 return false;
2112         else if (q < vi->curr_queue_pairs)
2113                 return true;
2114         else
2115                 return false;
2116 }
2117
2118 static void free_unused_bufs(struct virtnet_info *vi)
2119 {
2120         void *buf;
2121         int i;
2122
2123         for (i = 0; i < vi->max_queue_pairs; i++) {
2124                 struct virtqueue *vq = vi->sq[i].vq;
2125                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2126                         if (!is_xdp_raw_buffer_queue(vi, i))
2127                                 dev_kfree_skb(buf);
2128                         else
2129                                 put_page(virt_to_head_page(buf));
2130                 }
2131         }
2132
2133         for (i = 0; i < vi->max_queue_pairs; i++) {
2134                 struct virtqueue *vq = vi->rq[i].vq;
2135
2136                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2137                         if (vi->mergeable_rx_bufs) {
2138                                 put_page(virt_to_head_page(buf));
2139                         } else if (vi->big_packets) {
2140                                 give_pages(&vi->rq[i], buf);
2141                         } else {
2142                                 put_page(virt_to_head_page(buf));
2143                         }
2144                 }
2145         }
2146 }
2147
2148 static void virtnet_del_vqs(struct virtnet_info *vi)
2149 {
2150         struct virtio_device *vdev = vi->vdev;
2151
2152         virtnet_clean_affinity(vi, -1);
2153
2154         vdev->config->del_vqs(vdev);
2155
2156         virtnet_free_queues(vi);
2157 }
2158
2159 /* How large should a single buffer be so a queue full of these can fit at
2160  * least one full packet?
2161  * Logic below assumes the mergeable buffer header is used.
2162  */
2163 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2164 {
2165         const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2166         unsigned int rq_size = virtqueue_get_vring_size(vq);
2167         unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2168         unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2169         unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2170
2171         return max(max(min_buf_len, hdr_len) - hdr_len,
2172                    (unsigned int)GOOD_PACKET_LEN);
2173 }
2174
2175 static int virtnet_find_vqs(struct virtnet_info *vi)
2176 {
2177         vq_callback_t **callbacks;
2178         struct virtqueue **vqs;
2179         int ret = -ENOMEM;
2180         int i, total_vqs;
2181         const char **names;
2182         bool *ctx;
2183
2184         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2185          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2186          * possible control vq.
2187          */
2188         total_vqs = vi->max_queue_pairs * 2 +
2189                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2190
2191         /* Allocate space for find_vqs parameters */
2192         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
2193         if (!vqs)
2194                 goto err_vq;
2195         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
2196         if (!callbacks)
2197                 goto err_callback;
2198         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
2199         if (!names)
2200                 goto err_names;
2201         if (!vi->big_packets || vi->mergeable_rx_bufs) {
2202                 ctx = kzalloc(total_vqs * sizeof(*ctx), GFP_KERNEL);
2203                 if (!ctx)
2204                         goto err_ctx;
2205         } else {
2206                 ctx = NULL;
2207         }
2208
2209         /* Parameters for control virtqueue, if any */
2210         if (vi->has_cvq) {
2211                 callbacks[total_vqs - 1] = NULL;
2212                 names[total_vqs - 1] = "control";
2213         }
2214
2215         /* Allocate/initialize parameters for send/receive virtqueues */
2216         for (i = 0; i < vi->max_queue_pairs; i++) {
2217                 callbacks[rxq2vq(i)] = skb_recv_done;
2218                 callbacks[txq2vq(i)] = skb_xmit_done;
2219                 sprintf(vi->rq[i].name, "input.%d", i);
2220                 sprintf(vi->sq[i].name, "output.%d", i);
2221                 names[rxq2vq(i)] = vi->rq[i].name;
2222                 names[txq2vq(i)] = vi->sq[i].name;
2223                 if (ctx)
2224                         ctx[rxq2vq(i)] = true;
2225         }
2226
2227         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2228                                          names, ctx, NULL);
2229         if (ret)
2230                 goto err_find;
2231
2232         if (vi->has_cvq) {
2233                 vi->cvq = vqs[total_vqs - 1];
2234                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2235                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2236         }
2237
2238         for (i = 0; i < vi->max_queue_pairs; i++) {
2239                 vi->rq[i].vq = vqs[rxq2vq(i)];
2240                 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2241                 vi->sq[i].vq = vqs[txq2vq(i)];
2242         }
2243
2244         kfree(names);
2245         kfree(callbacks);
2246         kfree(vqs);
2247         kfree(ctx);
2248
2249         return 0;
2250
2251 err_find:
2252         kfree(ctx);
2253 err_ctx:
2254         kfree(names);
2255 err_names:
2256         kfree(callbacks);
2257 err_callback:
2258         kfree(vqs);
2259 err_vq:
2260         return ret;
2261 }
2262
2263 static int virtnet_alloc_queues(struct virtnet_info *vi)
2264 {
2265         int i;
2266
2267         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
2268         if (!vi->sq)
2269                 goto err_sq;
2270         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
2271         if (!vi->rq)
2272                 goto err_rq;
2273
2274         INIT_DELAYED_WORK(&vi->refill, refill_work);
2275         for (i = 0; i < vi->max_queue_pairs; i++) {
2276                 vi->rq[i].pages = NULL;
2277                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2278                                napi_weight);
2279                 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2280                                   napi_tx ? napi_weight : 0);
2281
2282                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2283                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2284                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2285         }
2286
2287         return 0;
2288
2289 err_rq:
2290         kfree(vi->sq);
2291 err_sq:
2292         return -ENOMEM;
2293 }
2294
2295 static int init_vqs(struct virtnet_info *vi)
2296 {
2297         int ret;
2298
2299         /* Allocate send & receive queues */
2300         ret = virtnet_alloc_queues(vi);
2301         if (ret)
2302                 goto err;
2303
2304         ret = virtnet_find_vqs(vi);
2305         if (ret)
2306                 goto err_free;
2307
2308         get_online_cpus();
2309         virtnet_set_affinity(vi);
2310         put_online_cpus();
2311
2312         return 0;
2313
2314 err_free:
2315         virtnet_free_queues(vi);
2316 err:
2317         return ret;
2318 }
2319
2320 #ifdef CONFIG_SYSFS
2321 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2322                 struct rx_queue_attribute *attribute, char *buf)
2323 {
2324         struct virtnet_info *vi = netdev_priv(queue->dev);
2325         unsigned int queue_index = get_netdev_rx_queue_index(queue);
2326         struct ewma_pkt_len *avg;
2327
2328         BUG_ON(queue_index >= vi->max_queue_pairs);
2329         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2330         return sprintf(buf, "%u\n",
2331                        get_mergeable_buf_len(&vi->rq[queue_index], avg));
2332 }
2333
2334 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2335         __ATTR_RO(mergeable_rx_buffer_size);
2336
2337 static struct attribute *virtio_net_mrg_rx_attrs[] = {
2338         &mergeable_rx_buffer_size_attribute.attr,
2339         NULL
2340 };
2341
2342 static const struct attribute_group virtio_net_mrg_rx_group = {
2343         .name = "virtio_net",
2344         .attrs = virtio_net_mrg_rx_attrs
2345 };
2346 #endif
2347
2348 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2349                                     unsigned int fbit,
2350                                     const char *fname, const char *dname)
2351 {
2352         if (!virtio_has_feature(vdev, fbit))
2353                 return false;
2354
2355         dev_err(&vdev->dev, "device advertises feature %s but not %s",
2356                 fname, dname);
2357
2358         return true;
2359 }
2360
2361 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
2362         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2363
2364 static bool virtnet_validate_features(struct virtio_device *vdev)
2365 {
2366         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2367             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2368                              "VIRTIO_NET_F_CTRL_VQ") ||
2369              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2370                              "VIRTIO_NET_F_CTRL_VQ") ||
2371              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2372                              "VIRTIO_NET_F_CTRL_VQ") ||
2373              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2374              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2375                              "VIRTIO_NET_F_CTRL_VQ"))) {
2376                 return false;
2377         }
2378
2379         return true;
2380 }
2381
2382 #define MIN_MTU ETH_MIN_MTU
2383 #define MAX_MTU ETH_MAX_MTU
2384
2385 static int virtnet_validate(struct virtio_device *vdev)
2386 {
2387         if (!vdev->config->get) {
2388                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2389                         __func__);
2390                 return -EINVAL;
2391         }
2392
2393         if (!virtnet_validate_features(vdev))
2394                 return -EINVAL;
2395
2396         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2397                 int mtu = virtio_cread16(vdev,
2398                                          offsetof(struct virtio_net_config,
2399                                                   mtu));
2400                 if (mtu < MIN_MTU)
2401                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2402         }
2403
2404         return 0;
2405 }
2406
2407 static int virtnet_probe(struct virtio_device *vdev)
2408 {
2409         int i, err;
2410         struct net_device *dev;
2411         struct virtnet_info *vi;
2412         u16 max_queue_pairs;
2413         int mtu;
2414
2415         /* Find if host supports multiqueue virtio_net device */
2416         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2417                                    struct virtio_net_config,
2418                                    max_virtqueue_pairs, &max_queue_pairs);
2419
2420         /* We need at least 2 queue's */
2421         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
2422             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
2423             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2424                 max_queue_pairs = 1;
2425
2426         /* Allocate ourselves a network device with room for our info */
2427         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
2428         if (!dev)
2429                 return -ENOMEM;
2430
2431         /* Set up network device as normal. */
2432         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
2433         dev->netdev_ops = &virtnet_netdev;
2434         dev->features = NETIF_F_HIGHDMA;
2435
2436         dev->ethtool_ops = &virtnet_ethtool_ops;
2437         SET_NETDEV_DEV(dev, &vdev->dev);
2438
2439         /* Do we support "hardware" checksums? */
2440         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
2441                 /* This opens up the world of extra features. */
2442                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2443                 if (csum)
2444                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2445
2446                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
2447                         dev->hw_features |= NETIF_F_TSO
2448                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
2449                 }
2450                 /* Individual feature bits: what can host handle? */
2451                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
2452                         dev->hw_features |= NETIF_F_TSO;
2453                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
2454                         dev->hw_features |= NETIF_F_TSO6;
2455                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
2456                         dev->hw_features |= NETIF_F_TSO_ECN;
2457
2458                 dev->features |= NETIF_F_GSO_ROBUST;
2459
2460                 if (gso)
2461                         dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
2462                 /* (!csum && gso) case will be fixed by register_netdev() */
2463         }
2464         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
2465                 dev->features |= NETIF_F_RXCSUM;
2466
2467         dev->vlan_features = dev->features;
2468
2469         /* MTU range: 68 - 65535 */
2470         dev->min_mtu = MIN_MTU;
2471         dev->max_mtu = MAX_MTU;
2472
2473         /* Configuration may specify what MAC to use.  Otherwise random. */
2474         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
2475                 virtio_cread_bytes(vdev,
2476                                    offsetof(struct virtio_net_config, mac),
2477                                    dev->dev_addr, dev->addr_len);
2478         else
2479                 eth_hw_addr_random(dev);
2480
2481         /* Set up our device-specific information */
2482         vi = netdev_priv(dev);
2483         vi->dev = dev;
2484         vi->vdev = vdev;
2485         vdev->priv = vi;
2486         vi->stats = alloc_percpu(struct virtnet_stats);
2487         err = -ENOMEM;
2488         if (vi->stats == NULL)
2489                 goto free;
2490
2491         for_each_possible_cpu(i) {
2492                 struct virtnet_stats *virtnet_stats;
2493                 virtnet_stats = per_cpu_ptr(vi->stats, i);
2494                 u64_stats_init(&virtnet_stats->tx_syncp);
2495                 u64_stats_init(&virtnet_stats->rx_syncp);
2496         }
2497
2498         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
2499
2500         /* If we can receive ANY GSO packets, we must allocate large ones. */
2501         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2502             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2503             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
2504             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
2505                 vi->big_packets = true;
2506
2507         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
2508                 vi->mergeable_rx_bufs = true;
2509
2510         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
2511             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2512                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2513         else
2514                 vi->hdr_len = sizeof(struct virtio_net_hdr);
2515
2516         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
2517             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2518                 vi->any_header_sg = true;
2519
2520         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2521                 vi->has_cvq = true;
2522
2523         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2524                 mtu = virtio_cread16(vdev,
2525                                      offsetof(struct virtio_net_config,
2526                                               mtu));
2527                 if (mtu < dev->min_mtu) {
2528                         /* Should never trigger: MTU was previously validated
2529                          * in virtnet_validate.
2530                          */
2531                         dev_err(&vdev->dev, "device MTU appears to have changed "
2532                                 "it is now %d < %d", mtu, dev->min_mtu);
2533                         goto free_stats;
2534                 }
2535
2536                 dev->mtu = mtu;
2537                 dev->max_mtu = mtu;
2538
2539                 /* TODO: size buffers correctly in this case. */
2540                 if (dev->mtu > ETH_DATA_LEN)
2541                         vi->big_packets = true;
2542         }
2543
2544         if (vi->any_header_sg)
2545                 dev->needed_headroom = vi->hdr_len;
2546
2547         /* Enable multiqueue by default */
2548         if (num_online_cpus() >= max_queue_pairs)
2549                 vi->curr_queue_pairs = max_queue_pairs;
2550         else
2551                 vi->curr_queue_pairs = num_online_cpus();
2552         vi->max_queue_pairs = max_queue_pairs;
2553
2554         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
2555         err = init_vqs(vi);
2556         if (err)
2557                 goto free_stats;
2558
2559 #ifdef CONFIG_SYSFS
2560         if (vi->mergeable_rx_bufs)
2561                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
2562 #endif
2563         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
2564         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
2565
2566         virtnet_init_settings(dev);
2567
2568         err = register_netdev(dev);
2569         if (err) {
2570                 pr_debug("virtio_net: registering device failed\n");
2571                 goto free_vqs;
2572         }
2573
2574         virtio_device_ready(vdev);
2575
2576         err = virtnet_cpu_notif_add(vi);
2577         if (err) {
2578                 pr_debug("virtio_net: registering cpu notifier failed\n");
2579                 goto free_unregister_netdev;
2580         }
2581
2582         virtnet_set_queues(vi, vi->curr_queue_pairs);
2583
2584         /* Assume link up if device can't report link status,
2585            otherwise get link status from config. */
2586         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
2587                 netif_carrier_off(dev);
2588                 schedule_work(&vi->config_work);
2589         } else {
2590                 vi->status = VIRTIO_NET_S_LINK_UP;
2591                 netif_carrier_on(dev);
2592         }
2593
2594         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
2595                  dev->name, max_queue_pairs);
2596
2597         return 0;
2598
2599 free_unregister_netdev:
2600         vi->vdev->config->reset(vdev);
2601
2602         unregister_netdev(dev);
2603 free_vqs:
2604         cancel_delayed_work_sync(&vi->refill);
2605         free_receive_page_frags(vi);
2606         virtnet_del_vqs(vi);
2607 free_stats:
2608         free_percpu(vi->stats);
2609 free:
2610         free_netdev(dev);
2611         return err;
2612 }
2613
2614 static void remove_vq_common(struct virtnet_info *vi)
2615 {
2616         vi->vdev->config->reset(vi->vdev);
2617
2618         /* Free unused buffers in both send and recv, if any. */
2619         free_unused_bufs(vi);
2620
2621         free_receive_bufs(vi);
2622
2623         free_receive_page_frags(vi);
2624
2625         virtnet_del_vqs(vi);
2626 }
2627
2628 static void virtnet_remove(struct virtio_device *vdev)
2629 {
2630         struct virtnet_info *vi = vdev->priv;
2631
2632         virtnet_cpu_notif_remove(vi);
2633
2634         /* Make sure no work handler is accessing the device. */
2635         flush_work(&vi->config_work);
2636
2637         unregister_netdev(vi->dev);
2638
2639         remove_vq_common(vi);
2640
2641         free_percpu(vi->stats);
2642         free_netdev(vi->dev);
2643 }
2644
2645 #ifdef CONFIG_PM_SLEEP
2646 static int virtnet_freeze(struct virtio_device *vdev)
2647 {
2648         struct virtnet_info *vi = vdev->priv;
2649
2650         virtnet_cpu_notif_remove(vi);
2651         virtnet_freeze_down(vdev);
2652         remove_vq_common(vi);
2653
2654         return 0;
2655 }
2656
2657 static int virtnet_restore(struct virtio_device *vdev)
2658 {
2659         struct virtnet_info *vi = vdev->priv;
2660         int err;
2661
2662         err = virtnet_restore_up(vdev);
2663         if (err)
2664                 return err;
2665         virtnet_set_queues(vi, vi->curr_queue_pairs);
2666
2667         err = virtnet_cpu_notif_add(vi);
2668         if (err)
2669                 return err;
2670
2671         return 0;
2672 }
2673 #endif
2674
2675 static struct virtio_device_id id_table[] = {
2676         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2677         { 0 },
2678 };
2679
2680 #define VIRTNET_FEATURES \
2681         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
2682         VIRTIO_NET_F_MAC, \
2683         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
2684         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
2685         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
2686         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
2687         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
2688         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
2689         VIRTIO_NET_F_CTRL_MAC_ADDR, \
2690         VIRTIO_NET_F_MTU
2691
2692 static unsigned int features[] = {
2693         VIRTNET_FEATURES,
2694 };
2695
2696 static unsigned int features_legacy[] = {
2697         VIRTNET_FEATURES,
2698         VIRTIO_NET_F_GSO,
2699         VIRTIO_F_ANY_LAYOUT,
2700 };
2701
2702 static struct virtio_driver virtio_net_driver = {
2703         .feature_table = features,
2704         .feature_table_size = ARRAY_SIZE(features),
2705         .feature_table_legacy = features_legacy,
2706         .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
2707         .driver.name =  KBUILD_MODNAME,
2708         .driver.owner = THIS_MODULE,
2709         .id_table =     id_table,
2710         .validate =     virtnet_validate,
2711         .probe =        virtnet_probe,
2712         .remove =       virtnet_remove,
2713         .config_changed = virtnet_config_changed,
2714 #ifdef CONFIG_PM_SLEEP
2715         .freeze =       virtnet_freeze,
2716         .restore =      virtnet_restore,
2717 #endif
2718 };
2719
2720 static __init int virtio_net_driver_init(void)
2721 {
2722         int ret;
2723
2724         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
2725                                       virtnet_cpu_online,
2726                                       virtnet_cpu_down_prep);
2727         if (ret < 0)
2728                 goto out;
2729         virtionet_online = ret;
2730         ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
2731                                       NULL, virtnet_cpu_dead);
2732         if (ret)
2733                 goto err_dead;
2734
2735         ret = register_virtio_driver(&virtio_net_driver);
2736         if (ret)
2737                 goto err_virtio;
2738         return 0;
2739 err_virtio:
2740         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2741 err_dead:
2742         cpuhp_remove_multi_state(virtionet_online);
2743 out:
2744         return ret;
2745 }
2746 module_init(virtio_net_driver_init);
2747
2748 static __exit void virtio_net_driver_exit(void)
2749 {
2750         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2751         cpuhp_remove_multi_state(virtionet_online);
2752         unregister_virtio_driver(&virtio_net_driver);
2753 }
2754 module_exit(virtio_net_driver_exit);
2755
2756 MODULE_DEVICE_TABLE(virtio, id_table);
2757 MODULE_DESCRIPTION("Virtio network driver");
2758 MODULE_LICENSE("GPL");