1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* A network driver using virtio.
3 *
4 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
5 */
6 //#define DEBUG
7 #include <linux/netdevice.h>
8 #include <linux/etherdevice.h>
9 #include <linux/ethtool.h>
10 #include <linux/module.h>
11 #include <linux/virtio.h>
12 #include <linux/virtio_net.h>
13 #include <linux/bpf.h>
14 #include <linux/bpf_trace.h>
15 #include <linux/scatterlist.h>
16 #include <linux/if_vlan.h>
17 #include <linux/slab.h>
18 #include <linux/cpu.h>
19 #include <linux/average.h>
20 #include <linux/filter.h>
21 #include <linux/kernel.h>
22 #include <net/route.h>
23 #include <net/xdp.h>
24 #include <net/net_failover.h>
25
26 static int napi_weight = NAPI_POLL_WEIGHT;
27 module_param(napi_weight, int, 0444);
28
29 static bool csum = true, gso = true, napi_tx = true;
30 module_param(csum, bool, 0444);
31 module_param(gso, bool, 0444);
32 module_param(napi_tx, bool, 0644);
33
34 /* FIXME: MTU in config. */
35 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
36 #define GOOD_COPY_LEN 128
37
38 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
39
40 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
41 #define VIRTIO_XDP_HEADROOM 256
42
43 /* Separating two types of XDP xmit */
44 #define VIRTIO_XDP_TX BIT(0)
45 #define VIRTIO_XDP_REDIR BIT(1)
46
47 #define VIRTIO_XDP_FLAG BIT(0)
48
49 /* RX packet size EWMA. The average packet size is used to determine the packet
50 * buffer size when refilling RX rings. As the entire RX ring may be refilled
51 * at once, the weight is chosen so that the EWMA will be insensitive to short-
52 * term, transient changes in packet size.
53 */
54 DECLARE_EWMA(pkt_len, 0, 64)
55
56 #define VIRTNET_DRIVER_VERSION "1.0.0"
57
58 static const unsigned long guest_offloads[] = {
59 VIRTIO_NET_F_GUEST_TSO4,
60 VIRTIO_NET_F_GUEST_TSO6,
61 VIRTIO_NET_F_GUEST_ECN,
62 VIRTIO_NET_F_GUEST_UFO,
63 VIRTIO_NET_F_GUEST_CSUM
64 };
65
66 #define GUEST_OFFLOAD_LRO_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
67 (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
68 (1ULL << VIRTIO_NET_F_GUEST_ECN) | \
69 (1ULL << VIRTIO_NET_F_GUEST_UFO))
70
71 struct virtnet_stat_desc {
72 char desc[ETH_GSTRING_LEN];
73 size_t offset;
74 };
75
76 struct virtnet_sq_stats {
77 struct u64_stats_sync syncp;
78 u64 packets;
79 u64 bytes;
80 u64 xdp_tx;
81 u64 xdp_tx_drops;
82 u64 kicks;
83 };
84
85 struct virtnet_rq_stats {
86 struct u64_stats_sync syncp;
87 u64 packets;
88 u64 bytes;
89 u64 drops;
90 u64 xdp_packets;
91 u64 xdp_tx;
92 u64 xdp_redirects;
93 u64 xdp_drops;
94 u64 kicks;
95 };
96
97 #define VIRTNET_SQ_STAT(m) offsetof(struct virtnet_sq_stats, m)
98 #define VIRTNET_RQ_STAT(m) offsetof(struct virtnet_rq_stats, m)
99
100 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
101 { "packets", VIRTNET_SQ_STAT(packets) },
102 { "bytes", VIRTNET_SQ_STAT(bytes) },
103 { "xdp_tx", VIRTNET_SQ_STAT(xdp_tx) },
104 { "xdp_tx_drops", VIRTNET_SQ_STAT(xdp_tx_drops) },
105 { "kicks", VIRTNET_SQ_STAT(kicks) },
106 };
107
108 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
109 { "packets", VIRTNET_RQ_STAT(packets) },
110 { "bytes", VIRTNET_RQ_STAT(bytes) },
111 { "drops", VIRTNET_RQ_STAT(drops) },
112 { "xdp_packets", VIRTNET_RQ_STAT(xdp_packets) },
113 { "xdp_tx", VIRTNET_RQ_STAT(xdp_tx) },
114 { "xdp_redirects", VIRTNET_RQ_STAT(xdp_redirects) },
115 { "xdp_drops", VIRTNET_RQ_STAT(xdp_drops) },
116 { "kicks", VIRTNET_RQ_STAT(kicks) },
117 };
118
119 #define VIRTNET_SQ_STATS_LEN ARRAY_SIZE(virtnet_sq_stats_desc)
120 #define VIRTNET_RQ_STATS_LEN ARRAY_SIZE(virtnet_rq_stats_desc)
121
122 /* Internal representation of a send virtqueue */
123 struct send_queue {
124 /* Virtqueue associated with this send _queue */
125 struct virtqueue *vq;
126
127 /* TX: fragments + linear part + virtio header */
128 struct scatterlist sg[MAX_SKB_FRAGS + 2];
129
130 /* Name of the send queue: output.$index */
131 char name[40];
132
133 struct virtnet_sq_stats stats;
134
135 struct napi_struct napi;
136 };
137
138 /* Internal representation of a receive virtqueue */
139 struct receive_queue {
140 /* Virtqueue associated with this receive_queue */
141 struct virtqueue *vq;
142
143 struct napi_struct napi;
144
145 struct bpf_prog __rcu *xdp_prog;
146
147 struct virtnet_rq_stats stats;
148
149 /* Chain pages by the private ptr. */
150 struct page *pages;
151
152 /* Average packet length for mergeable receive buffers. */
153 struct ewma_pkt_len mrg_avg_pkt_len;
154
155 /* Page frag for packet buffer allocation. */
156 struct page_frag alloc_frag;
157
158 /* RX: fragments + linear part + virtio header */
159 struct scatterlist sg[MAX_SKB_FRAGS + 2];
160
161 /* Min single buffer size for mergeable buffers case. */
162 unsigned int min_buf_len;
163
164 /* Name of this receive queue: input.$index */
165 char name[40];
166
167 struct xdp_rxq_info xdp_rxq;
168 };
169
170 /* Control VQ buffers: protected by the rtnl lock */
171 struct control_buf {
172 struct virtio_net_ctrl_hdr hdr;
173 virtio_net_ctrl_ack status;
174 struct virtio_net_ctrl_mq mq;
175 u8 promisc;
176 u8 allmulti;
177 __virtio16 vid;
178 __virtio64 offloads;
179 };
180
181 struct virtnet_info {
182 struct virtio_device *vdev;
183 struct virtqueue *cvq;
184 struct net_device *dev;
185 struct send_queue *sq;
186 struct receive_queue *rq;
187 unsigned int status;
188
189 /* Max # of queue pairs supported by the device */
190 u16 max_queue_pairs;
191
192 /* # of queue pairs currently used by the driver */
193 u16 curr_queue_pairs;
194
195 /* # of XDP queue pairs currently used by the driver */
196 u16 xdp_queue_pairs;
197
198 /* xdp_queue_pairs may be 0, when xdp is already loaded. So add this. */
199 bool xdp_enabled;
200
201 /* I like... big packets and I cannot lie! */
202 bool big_packets;
203
204 /* Host will merge rx buffers for big packets (shake it! shake it!) */
205 bool mergeable_rx_bufs;
206
207 /* Has control virtqueue */
208 bool has_cvq;
209
210 /* Host can handle any s/g split between our header and packet data */
211 bool any_header_sg;
212
213 /* Packet virtio header size */
214 u8 hdr_len;
215
216 /* Work struct for refilling if we run low on memory. */
217 struct delayed_work refill;
218
219 /* Work struct for config space updates */
220 struct work_struct config_work;
221
222 /* Does the affinity hint is set for virtqueues? */
223 bool affinity_hint_set;
224
225 /* CPU hotplug instances for online & dead */
226 struct hlist_node node;
227 struct hlist_node node_dead;
228
229 struct control_buf *ctrl;
230
231 /* Ethtool settings */
232 u8 duplex;
233 u32 speed;
234
235 unsigned long guest_offloads;
236 unsigned long guest_offloads_capable;
237
238 /* failover when STANDBY feature enabled */
239 struct failover *failover;
240 };
241
242 struct padded_vnet_hdr {
243 struct virtio_net_hdr_mrg_rxbuf hdr;
244 /*
245 * hdr is in a separate sg buffer, and data sg buffer shares same page
246 * with this header sg. This padding makes next sg 16 byte aligned
247 * after the header.
248 */
249 char padding[4];
250 };
251
is_xdp_frame(void * ptr)252 static bool is_xdp_frame(void *ptr)
253 {
254 return (unsigned long)ptr & VIRTIO_XDP_FLAG;
255 }
256
xdp_to_ptr(struct xdp_frame * ptr)257 static void *xdp_to_ptr(struct xdp_frame *ptr)
258 {
259 return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
260 }
261
ptr_to_xdp(void * ptr)262 static struct xdp_frame *ptr_to_xdp(void *ptr)
263 {
264 return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
265 }
266
267 /* Converting between virtqueue no. and kernel tx/rx queue no.
268 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
269 */
vq2txq(struct virtqueue * vq)270 static int vq2txq(struct virtqueue *vq)
271 {
272 return (vq->index - 1) / 2;
273 }
274
txq2vq(int txq)275 static int txq2vq(int txq)
276 {
277 return txq * 2 + 1;
278 }
279
vq2rxq(struct virtqueue * vq)280 static int vq2rxq(struct virtqueue *vq)
281 {
282 return vq->index / 2;
283 }
284
rxq2vq(int rxq)285 static int rxq2vq(int rxq)
286 {
287 return rxq * 2;
288 }
289
skb_vnet_hdr(struct sk_buff * skb)290 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
291 {
292 return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
293 }
294
295 /*
296 * private is used to chain pages for big packets, put the whole
297 * most recent used list in the beginning for reuse
298 */
give_pages(struct receive_queue * rq,struct page * page)299 static void give_pages(struct receive_queue *rq, struct page *page)
300 {
301 struct page *end;
302
303 /* Find end of list, sew whole thing into vi->rq.pages. */
304 for (end = page; end->private; end = (struct page *)end->private);
305 end->private = (unsigned long)rq->pages;
306 rq->pages = page;
307 }
308
get_a_page(struct receive_queue * rq,gfp_t gfp_mask)309 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
310 {
311 struct page *p = rq->pages;
312
313 if (p) {
314 rq->pages = (struct page *)p->private;
315 /* clear private here, it is used to chain pages */
316 p->private = 0;
317 } else
318 p = alloc_page(gfp_mask);
319 return p;
320 }
321
virtqueue_napi_schedule(struct napi_struct * napi,struct virtqueue * vq)322 static void virtqueue_napi_schedule(struct napi_struct *napi,
323 struct virtqueue *vq)
324 {
325 if (napi_schedule_prep(napi)) {
326 virtqueue_disable_cb(vq);
327 __napi_schedule(napi);
328 }
329 }
330
virtqueue_napi_complete(struct napi_struct * napi,struct virtqueue * vq,int processed)331 static void virtqueue_napi_complete(struct napi_struct *napi,
332 struct virtqueue *vq, int processed)
333 {
334 int opaque;
335
336 opaque = virtqueue_enable_cb_prepare(vq);
337 if (napi_complete_done(napi, processed)) {
338 if (unlikely(virtqueue_poll(vq, opaque)))
339 virtqueue_napi_schedule(napi, vq);
340 } else {
341 virtqueue_disable_cb(vq);
342 }
343 }
344
skb_xmit_done(struct virtqueue * vq)345 static void skb_xmit_done(struct virtqueue *vq)
346 {
347 struct virtnet_info *vi = vq->vdev->priv;
348 struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
349
350 /* Suppress further interrupts. */
351 virtqueue_disable_cb(vq);
352
353 if (napi->weight)
354 virtqueue_napi_schedule(napi, vq);
355 else
356 /* We were probably waiting for more output buffers. */
357 netif_wake_subqueue(vi->dev, vq2txq(vq));
358 }
359
360 #define MRG_CTX_HEADER_SHIFT 22
mergeable_len_to_ctx(unsigned int truesize,unsigned int headroom)361 static void *mergeable_len_to_ctx(unsigned int truesize,
362 unsigned int headroom)
363 {
364 return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
365 }
366
mergeable_ctx_to_headroom(void * mrg_ctx)367 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
368 {
369 return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
370 }
371
mergeable_ctx_to_truesize(void * mrg_ctx)372 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
373 {
374 return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
375 }
376
377 /* Called from bottom half context */
page_to_skb(struct virtnet_info * vi,struct receive_queue * rq,struct page * page,unsigned int offset,unsigned int len,unsigned int truesize,bool hdr_valid,unsigned int metasize,unsigned int headroom)378 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
379 struct receive_queue *rq,
380 struct page *page, unsigned int offset,
381 unsigned int len, unsigned int truesize,
382 bool hdr_valid, unsigned int metasize,
383 unsigned int headroom)
384 {
385 struct sk_buff *skb;
386 struct virtio_net_hdr_mrg_rxbuf *hdr;
387 unsigned int copy, hdr_len, hdr_padded_len;
388 struct page *page_to_free = NULL;
389 int tailroom, shinfo_size;
390 char *p, *hdr_p, *buf;
391
392 p = page_address(page) + offset;
393 hdr_p = p;
394
395 hdr_len = vi->hdr_len;
396 if (vi->mergeable_rx_bufs)
397 hdr_padded_len = sizeof(*hdr);
398 else
399 hdr_padded_len = sizeof(struct padded_vnet_hdr);
400
401 /* If headroom is not 0, there is an offset between the beginning of the
402 * data and the allocated space, otherwise the data and the allocated
403 * space are aligned.
404 */
405 if (headroom) {
406 /* Buffers with headroom use PAGE_SIZE as alloc size,
407 * see add_recvbuf_mergeable() + get_mergeable_buf_len()
408 */
409 truesize = PAGE_SIZE;
410 tailroom = truesize - len - offset;
411 buf = page_address(page);
412 } else {
413 tailroom = truesize - len;
414 buf = p;
415 }
416
417 len -= hdr_len;
418 offset += hdr_padded_len;
419 p += hdr_padded_len;
420
421 shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
422
423 /* copy small packet so we can reuse these pages */
424 if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) {
425 skb = build_skb(buf, truesize);
426 if (unlikely(!skb))
427 return NULL;
428
429 skb_reserve(skb, p - buf);
430 skb_put(skb, len);
431 goto ok;
432 }
433
434 /* copy small packet so we can reuse these pages for small data */
435 skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
436 if (unlikely(!skb))
437 return NULL;
438
439 /* Copy all frame if it fits skb->head, otherwise
440 * we let virtio_net_hdr_to_skb() and GRO pull headers as needed.
441 */
442 if (len <= skb_tailroom(skb))
443 copy = len;
444 else
445 copy = ETH_HLEN + metasize;
446 skb_put_data(skb, p, copy);
447
448 len -= copy;
449 offset += copy;
450
451 if (vi->mergeable_rx_bufs) {
452 if (len)
453 skb_add_rx_frag(skb, 0, page, offset, len, truesize);
454 else
455 page_to_free = page;
456 goto ok;
457 }
458
459 /*
460 * Verify that we can indeed put this data into a skb.
461 * This is here to handle cases when the device erroneously
462 * tries to receive more than is possible. This is usually
463 * the case of a broken device.
464 */
465 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
466 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
467 dev_kfree_skb(skb);
468 return NULL;
469 }
470 BUG_ON(offset >= PAGE_SIZE);
471 while (len) {
472 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
473 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
474 frag_size, truesize);
475 len -= frag_size;
476 page = (struct page *)page->private;
477 offset = 0;
478 }
479
480 if (page)
481 give_pages(rq, page);
482
483 ok:
484 /* hdr_valid means no XDP, so we can copy the vnet header */
485 if (hdr_valid) {
486 hdr = skb_vnet_hdr(skb);
487 memcpy(hdr, hdr_p, hdr_len);
488 }
489 if (page_to_free)
490 put_page(page_to_free);
491
492 if (metasize) {
493 __skb_pull(skb, metasize);
494 skb_metadata_set(skb, metasize);
495 }
496
497 return skb;
498 }
499
__virtnet_xdp_xmit_one(struct virtnet_info * vi,struct send_queue * sq,struct xdp_frame * xdpf)500 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
501 struct send_queue *sq,
502 struct xdp_frame *xdpf)
503 {
504 struct virtio_net_hdr_mrg_rxbuf *hdr;
505 int err;
506
507 if (unlikely(xdpf->headroom < vi->hdr_len))
508 return -EOVERFLOW;
509
510 /* Make room for virtqueue hdr (also change xdpf->headroom?) */
511 xdpf->data -= vi->hdr_len;
512 /* Zero header and leave csum up to XDP layers */
513 hdr = xdpf->data;
514 memset(hdr, 0, vi->hdr_len);
515 xdpf->len += vi->hdr_len;
516
517 sg_init_one(sq->sg, xdpf->data, xdpf->len);
518
519 err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
520 GFP_ATOMIC);
521 if (unlikely(err))
522 return -ENOSPC; /* Caller handle free/refcnt */
523
524 return 0;
525 }
526
527 /* when vi->curr_queue_pairs > nr_cpu_ids, the txq/sq is only used for xdp tx on
528 * the current cpu, so it does not need to be locked.
529 *
530 * Here we use marco instead of inline functions because we have to deal with
531 * three issues at the same time: 1. the choice of sq. 2. judge and execute the
532 * lock/unlock of txq 3. make sparse happy. It is difficult for two inline
533 * functions to perfectly solve these three problems at the same time.
534 */
535 #define virtnet_xdp_get_sq(vi) ({ \
536 struct netdev_queue *txq; \
537 typeof(vi) v = (vi); \
538 unsigned int qp; \
539 \
540 if (v->curr_queue_pairs > nr_cpu_ids) { \
541 qp = v->curr_queue_pairs - v->xdp_queue_pairs; \
542 qp += smp_processor_id(); \
543 txq = netdev_get_tx_queue(v->dev, qp); \
544 __netif_tx_acquire(txq); \
545 } else { \
546 qp = smp_processor_id() % v->curr_queue_pairs; \
547 txq = netdev_get_tx_queue(v->dev, qp); \
548 __netif_tx_lock(txq, raw_smp_processor_id()); \
549 } \
550 v->sq + qp; \
551 })
552
553 #define virtnet_xdp_put_sq(vi, q) { \
554 struct netdev_queue *txq; \
555 typeof(vi) v = (vi); \
556 \
557 txq = netdev_get_tx_queue(v->dev, (q) - v->sq); \
558 if (v->curr_queue_pairs > nr_cpu_ids) \
559 __netif_tx_release(txq); \
560 else \
561 __netif_tx_unlock(txq); \
562 }
563
virtnet_xdp_xmit(struct net_device * dev,int n,struct xdp_frame ** frames,u32 flags)564 static int virtnet_xdp_xmit(struct net_device *dev,
565 int n, struct xdp_frame **frames, u32 flags)
566 {
567 struct virtnet_info *vi = netdev_priv(dev);
568 struct receive_queue *rq = vi->rq;
569 struct bpf_prog *xdp_prog;
570 struct send_queue *sq;
571 unsigned int len;
572 int packets = 0;
573 int bytes = 0;
574 int nxmit = 0;
575 int kicks = 0;
576 void *ptr;
577 int ret;
578 int i;
579
580 /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
581 * indicate XDP resources have been successfully allocated.
582 */
583 xdp_prog = rcu_access_pointer(rq->xdp_prog);
584 if (!xdp_prog)
585 return -ENXIO;
586
587 sq = virtnet_xdp_get_sq(vi);
588
589 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
590 ret = -EINVAL;
591 goto out;
592 }
593
594 /* Free up any pending old buffers before queueing new ones. */
595 while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
596 if (likely(is_xdp_frame(ptr))) {
597 struct xdp_frame *frame = ptr_to_xdp(ptr);
598
599 bytes += frame->len;
600 xdp_return_frame(frame);
601 } else {
602 struct sk_buff *skb = ptr;
603
604 bytes += skb->len;
605 napi_consume_skb(skb, false);
606 }
607 packets++;
608 }
609
610 for (i = 0; i < n; i++) {
611 struct xdp_frame *xdpf = frames[i];
612
613 if (__virtnet_xdp_xmit_one(vi, sq, xdpf))
614 break;
615 nxmit++;
616 }
617 ret = nxmit;
618
619 if (flags & XDP_XMIT_FLUSH) {
620 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
621 kicks = 1;
622 }
623 out:
624 u64_stats_update_begin(&sq->stats.syncp);
625 sq->stats.bytes += bytes;
626 sq->stats.packets += packets;
627 sq->stats.xdp_tx += n;
628 sq->stats.xdp_tx_drops += n - nxmit;
629 sq->stats.kicks += kicks;
630 u64_stats_update_end(&sq->stats.syncp);
631
632 virtnet_xdp_put_sq(vi, sq);
633 return ret;
634 }
635
virtnet_get_headroom(struct virtnet_info * vi)636 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
637 {
638 return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0;
639 }
640
641 /* We copy the packet for XDP in the following cases:
642 *
643 * 1) Packet is scattered across multiple rx buffers.
644 * 2) Headroom space is insufficient.
645 *
646 * This is inefficient but it's a temporary condition that
647 * we hit right after XDP is enabled and until queue is refilled
648 * with large buffers with sufficient headroom - so it should affect
649 * at most queue size packets.
650 * Afterwards, the conditions to enable
651 * XDP should preclude the underlying device from sending packets
652 * across multiple buffers (num_buf > 1), and we make sure buffers
653 * have enough headroom.
654 */
xdp_linearize_page(struct receive_queue * rq,u16 * num_buf,struct page * p,int offset,int page_off,unsigned int * len)655 static struct page *xdp_linearize_page(struct receive_queue *rq,
656 u16 *num_buf,
657 struct page *p,
658 int offset,
659 int page_off,
660 unsigned int *len)
661 {
662 struct page *page = alloc_page(GFP_ATOMIC);
663
664 if (!page)
665 return NULL;
666
667 memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
668 page_off += *len;
669
670 while (--*num_buf) {
671 int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
672 unsigned int buflen;
673 void *buf;
674 int off;
675
676 buf = virtqueue_get_buf(rq->vq, &buflen);
677 if (unlikely(!buf))
678 goto err_buf;
679
680 p = virt_to_head_page(buf);
681 off = buf - page_address(p);
682
683 /* guard against a misconfigured or uncooperative backend that
684 * is sending packet larger than the MTU.
685 */
686 if ((page_off + buflen + tailroom) > PAGE_SIZE) {
687 put_page(p);
688 goto err_buf;
689 }
690
691 memcpy(page_address(page) + page_off,
692 page_address(p) + off, buflen);
693 page_off += buflen;
694 put_page(p);
695 }
696
697 /* Headroom does not contribute to packet length */
698 *len = page_off - VIRTIO_XDP_HEADROOM;
699 return page;
700 err_buf:
701 __free_pages(page, 0);
702 return NULL;
703 }
704
receive_small(struct net_device * dev,struct virtnet_info * vi,struct receive_queue * rq,void * buf,void * ctx,unsigned int len,unsigned int * xdp_xmit,struct virtnet_rq_stats * stats)705 static struct sk_buff *receive_small(struct net_device *dev,
706 struct virtnet_info *vi,
707 struct receive_queue *rq,
708 void *buf, void *ctx,
709 unsigned int len,
710 unsigned int *xdp_xmit,
711 struct virtnet_rq_stats *stats)
712 {
713 struct sk_buff *skb;
714 struct bpf_prog *xdp_prog;
715 unsigned int xdp_headroom = (unsigned long)ctx;
716 unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
717 unsigned int headroom = vi->hdr_len + header_offset;
718 unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
719 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
720 struct page *page = virt_to_head_page(buf);
721 unsigned int delta = 0;
722 struct page *xdp_page;
723 int err;
724 unsigned int metasize = 0;
725
726 len -= vi->hdr_len;
727 stats->bytes += len;
728
729 rcu_read_lock();
730 xdp_prog = rcu_dereference(rq->xdp_prog);
731 if (xdp_prog) {
732 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
733 struct xdp_frame *xdpf;
734 struct xdp_buff xdp;
735 void *orig_data;
736 u32 act;
737
738 if (unlikely(hdr->hdr.gso_type))
739 goto err_xdp;
740
741 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
742 int offset = buf - page_address(page) + header_offset;
743 unsigned int tlen = len + vi->hdr_len;
744 u16 num_buf = 1;
745
746 xdp_headroom = virtnet_get_headroom(vi);
747 header_offset = VIRTNET_RX_PAD + xdp_headroom;
748 headroom = vi->hdr_len + header_offset;
749 buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
750 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
751 xdp_page = xdp_linearize_page(rq, &num_buf, page,
752 offset, header_offset,
753 &tlen);
754 if (!xdp_page)
755 goto err_xdp;
756
757 buf = page_address(xdp_page);
758 put_page(page);
759 page = xdp_page;
760 }
761
762 xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
763 xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
764 xdp_headroom, len, true);
765 orig_data = xdp.data;
766 act = bpf_prog_run_xdp(xdp_prog, &xdp);
767 stats->xdp_packets++;
768
769 switch (act) {
770 case XDP_PASS:
771 /* Recalculate length in case bpf program changed it */
772 delta = orig_data - xdp.data;
773 len = xdp.data_end - xdp.data;
774 metasize = xdp.data - xdp.data_meta;
775 break;
776 case XDP_TX:
777 stats->xdp_tx++;
778 xdpf = xdp_convert_buff_to_frame(&xdp);
779 if (unlikely(!xdpf))
780 goto err_xdp;
781 err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
782 if (unlikely(!err)) {
783 xdp_return_frame_rx_napi(xdpf);
784 } else if (unlikely(err < 0)) {
785 trace_xdp_exception(vi->dev, xdp_prog, act);
786 goto err_xdp;
787 }
788 *xdp_xmit |= VIRTIO_XDP_TX;
789 rcu_read_unlock();
790 goto xdp_xmit;
791 case XDP_REDIRECT:
792 stats->xdp_redirects++;
793 err = xdp_do_redirect(dev, &xdp, xdp_prog);
794 if (err)
795 goto err_xdp;
796 *xdp_xmit |= VIRTIO_XDP_REDIR;
797 rcu_read_unlock();
798 goto xdp_xmit;
799 default:
800 bpf_warn_invalid_xdp_action(act);
801 fallthrough;
802 case XDP_ABORTED:
803 trace_xdp_exception(vi->dev, xdp_prog, act);
804 goto err_xdp;
805 case XDP_DROP:
806 goto err_xdp;
807 }
808 }
809 rcu_read_unlock();
810
811 skb = build_skb(buf, buflen);
812 if (!skb) {
813 put_page(page);
814 goto err;
815 }
816 skb_reserve(skb, headroom - delta);
817 skb_put(skb, len);
818 if (!xdp_prog) {
819 buf += header_offset;
820 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
821 } /* keep zeroed vnet hdr since XDP is loaded */
822
823 if (metasize)
824 skb_metadata_set(skb, metasize);
825
826 err:
827 return skb;
828
829 err_xdp:
830 rcu_read_unlock();
831 stats->xdp_drops++;
832 stats->drops++;
833 put_page(page);
834 xdp_xmit:
835 return NULL;
836 }
837
receive_big(struct net_device * dev,struct virtnet_info * vi,struct receive_queue * rq,void * buf,unsigned int len,struct virtnet_rq_stats * stats)838 static struct sk_buff *receive_big(struct net_device *dev,
839 struct virtnet_info *vi,
840 struct receive_queue *rq,
841 void *buf,
842 unsigned int len,
843 struct virtnet_rq_stats *stats)
844 {
845 struct page *page = buf;
846 struct sk_buff *skb =
847 page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0, 0);
848
849 stats->bytes += len - vi->hdr_len;
850 if (unlikely(!skb))
851 goto err;
852
853 return skb;
854
855 err:
856 stats->drops++;
857 give_pages(rq, page);
858 return NULL;
859 }
860
receive_mergeable(struct net_device * dev,struct virtnet_info * vi,struct receive_queue * rq,void * buf,void * ctx,unsigned int len,unsigned int * xdp_xmit,struct virtnet_rq_stats * stats)861 static struct sk_buff *receive_mergeable(struct net_device *dev,
862 struct virtnet_info *vi,
863 struct receive_queue *rq,
864 void *buf,
865 void *ctx,
866 unsigned int len,
867 unsigned int *xdp_xmit,
868 struct virtnet_rq_stats *stats)
869 {
870 struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
871 u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
872 struct page *page = virt_to_head_page(buf);
873 int offset = buf - page_address(page);
874 struct sk_buff *head_skb, *curr_skb;
875 struct bpf_prog *xdp_prog;
876 unsigned int truesize = mergeable_ctx_to_truesize(ctx);
877 unsigned int headroom = mergeable_ctx_to_headroom(ctx);
878 unsigned int metasize = 0;
879 unsigned int frame_sz;
880 int err;
881
882 head_skb = NULL;
883 stats->bytes += len - vi->hdr_len;
884
885 rcu_read_lock();
886 xdp_prog = rcu_dereference(rq->xdp_prog);
887 if (xdp_prog) {
888 struct xdp_frame *xdpf;
889 struct page *xdp_page;
890 struct xdp_buff xdp;
891 void *data;
892 u32 act;
893
894 /* Transient failure which in theory could occur if
895 * in-flight packets from before XDP was enabled reach
896 * the receive path after XDP is loaded.
897 */
898 if (unlikely(hdr->hdr.gso_type))
899 goto err_xdp;
900
901 /* Buffers with headroom use PAGE_SIZE as alloc size,
902 * see add_recvbuf_mergeable() + get_mergeable_buf_len()
903 */
904 frame_sz = headroom ? PAGE_SIZE : truesize;
905
906 /* This happens when rx buffer size is underestimated
907 * or headroom is not enough because of the buffer
908 * was refilled before XDP is set. This should only
909 * happen for the first several packets, so we don't
910 * care much about its performance.
911 */
912 if (unlikely(num_buf > 1 ||
913 headroom < virtnet_get_headroom(vi))) {
914 /* linearize data for XDP */
915 xdp_page = xdp_linearize_page(rq, &num_buf,
916 page, offset,
917 VIRTIO_XDP_HEADROOM,
918 &len);
919 frame_sz = PAGE_SIZE;
920
921 if (!xdp_page)
922 goto err_xdp;
923 offset = VIRTIO_XDP_HEADROOM;
924 } else {
925 xdp_page = page;
926 }
927
928 /* Allow consuming headroom but reserve enough space to push
929 * the descriptor on if we get an XDP_TX return code.
930 */
931 data = page_address(xdp_page) + offset;
932 xdp_init_buff(&xdp, frame_sz - vi->hdr_len, &rq->xdp_rxq);
933 xdp_prepare_buff(&xdp, data - VIRTIO_XDP_HEADROOM + vi->hdr_len,
934 VIRTIO_XDP_HEADROOM, len - vi->hdr_len, true);
935
936 act = bpf_prog_run_xdp(xdp_prog, &xdp);
937 stats->xdp_packets++;
938
939 switch (act) {
940 case XDP_PASS:
941 metasize = xdp.data - xdp.data_meta;
942
943 /* recalculate offset to account for any header
944 * adjustments and minus the metasize to copy the
945 * metadata in page_to_skb(). Note other cases do not
946 * build an skb and avoid using offset
947 */
948 offset = xdp.data - page_address(xdp_page) -
949 vi->hdr_len - metasize;
950
951 /* recalculate len if xdp.data, xdp.data_end or
952 * xdp.data_meta were adjusted
953 */
954 len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
955 /* We can only create skb based on xdp_page. */
956 if (unlikely(xdp_page != page)) {
957 rcu_read_unlock();
958 put_page(page);
959 head_skb = page_to_skb(vi, rq, xdp_page, offset,
960 len, PAGE_SIZE, false,
961 metasize, headroom);
962 return head_skb;
963 }
964 break;
965 case XDP_TX:
966 stats->xdp_tx++;
967 xdpf = xdp_convert_buff_to_frame(&xdp);
968 if (unlikely(!xdpf))
969 goto err_xdp;
970 err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
971 if (unlikely(!err)) {
972 xdp_return_frame_rx_napi(xdpf);
973 } else if (unlikely(err < 0)) {
974 trace_xdp_exception(vi->dev, xdp_prog, act);
975 if (unlikely(xdp_page != page))
976 put_page(xdp_page);
977 goto err_xdp;
978 }
979 *xdp_xmit |= VIRTIO_XDP_TX;
980 if (unlikely(xdp_page != page))
981 put_page(page);
982 rcu_read_unlock();
983 goto xdp_xmit;
984 case XDP_REDIRECT:
985 stats->xdp_redirects++;
986 err = xdp_do_redirect(dev, &xdp, xdp_prog);
987 if (err) {
988 if (unlikely(xdp_page != page))
989 put_page(xdp_page);
990 goto err_xdp;
991 }
992 *xdp_xmit |= VIRTIO_XDP_REDIR;
993 if (unlikely(xdp_page != page))
994 put_page(page);
995 rcu_read_unlock();
996 goto xdp_xmit;
997 default:
998 bpf_warn_invalid_xdp_action(act);
999 fallthrough;
1000 case XDP_ABORTED:
1001 trace_xdp_exception(vi->dev, xdp_prog, act);
1002 fallthrough;
1003 case XDP_DROP:
1004 if (unlikely(xdp_page != page))
1005 __free_pages(xdp_page, 0);
1006 goto err_xdp;
1007 }
1008 }
1009 rcu_read_unlock();
1010
1011 if (unlikely(len > truesize)) {
1012 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1013 dev->name, len, (unsigned long)ctx);
1014 dev->stats.rx_length_errors++;
1015 goto err_skb;
1016 }
1017
1018 head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
1019 metasize, headroom);
1020 curr_skb = head_skb;
1021
1022 if (unlikely(!curr_skb))
1023 goto err_skb;
1024 while (--num_buf) {
1025 int num_skb_frags;
1026
1027 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1028 if (unlikely(!buf)) {
1029 pr_debug("%s: rx error: %d buffers out of %d missing\n",
1030 dev->name, num_buf,
1031 virtio16_to_cpu(vi->vdev,
1032 hdr->num_buffers));
1033 dev->stats.rx_length_errors++;
1034 goto err_buf;
1035 }
1036
1037 stats->bytes += len;
1038 page = virt_to_head_page(buf);
1039
1040 truesize = mergeable_ctx_to_truesize(ctx);
1041 if (unlikely(len > truesize)) {
1042 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1043 dev->name, len, (unsigned long)ctx);
1044 dev->stats.rx_length_errors++;
1045 goto err_skb;
1046 }
1047
1048 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
1049 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
1050 struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
1051
1052 if (unlikely(!nskb))
1053 goto err_skb;
1054 if (curr_skb == head_skb)
1055 skb_shinfo(curr_skb)->frag_list = nskb;
1056 else
1057 curr_skb->next = nskb;
1058 curr_skb = nskb;
1059 head_skb->truesize += nskb->truesize;
1060 num_skb_frags = 0;
1061 }
1062 if (curr_skb != head_skb) {
1063 head_skb->data_len += len;
1064 head_skb->len += len;
1065 head_skb->truesize += truesize;
1066 }
1067 offset = buf - page_address(page);
1068 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
1069 put_page(page);
1070 skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
1071 len, truesize);
1072 } else {
1073 skb_add_rx_frag(curr_skb, num_skb_frags, page,
1074 offset, len, truesize);
1075 }
1076 }
1077
1078 ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
1079 return head_skb;
1080
1081 err_xdp:
1082 rcu_read_unlock();
1083 stats->xdp_drops++;
1084 err_skb:
1085 put_page(page);
1086 while (num_buf-- > 1) {
1087 buf = virtqueue_get_buf(rq->vq, &len);
1088 if (unlikely(!buf)) {
1089 pr_debug("%s: rx error: %d buffers missing\n",
1090 dev->name, num_buf);
1091 dev->stats.rx_length_errors++;
1092 break;
1093 }
1094 stats->bytes += len;
1095 page = virt_to_head_page(buf);
1096 put_page(page);
1097 }
1098 err_buf:
1099 stats->drops++;
1100 dev_kfree_skb(head_skb);
1101 xdp_xmit:
1102 return NULL;
1103 }
1104
receive_buf(struct virtnet_info * vi,struct receive_queue * rq,void * buf,unsigned int len,void ** ctx,unsigned int * xdp_xmit,struct virtnet_rq_stats * stats)1105 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1106 void *buf, unsigned int len, void **ctx,
1107 unsigned int *xdp_xmit,
1108 struct virtnet_rq_stats *stats)
1109 {
1110 struct net_device *dev = vi->dev;
1111 struct sk_buff *skb;
1112 struct virtio_net_hdr_mrg_rxbuf *hdr;
1113
1114 if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1115 pr_debug("%s: short packet %i\n", dev->name, len);
1116 dev->stats.rx_length_errors++;
1117 if (vi->mergeable_rx_bufs) {
1118 put_page(virt_to_head_page(buf));
1119 } else if (vi->big_packets) {
1120 give_pages(rq, buf);
1121 } else {
1122 put_page(virt_to_head_page(buf));
1123 }
1124 return;
1125 }
1126
1127 if (vi->mergeable_rx_bufs)
1128 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1129 stats);
1130 else if (vi->big_packets)
1131 skb = receive_big(dev, vi, rq, buf, len, stats);
1132 else
1133 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1134
1135 if (unlikely(!skb))
1136 return;
1137
1138 hdr = skb_vnet_hdr(skb);
1139
1140 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1141 skb->ip_summed = CHECKSUM_UNNECESSARY;
1142
1143 if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1144 virtio_is_little_endian(vi->vdev))) {
1145 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1146 dev->name, hdr->hdr.gso_type,
1147 hdr->hdr.gso_size);
1148 goto frame_err;
1149 }
1150
1151 skb_record_rx_queue(skb, vq2rxq(rq->vq));
1152 skb->protocol = eth_type_trans(skb, dev);
1153 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1154 ntohs(skb->protocol), skb->len, skb->pkt_type);
1155
1156 napi_gro_receive(&rq->napi, skb);
1157 return;
1158
1159 frame_err:
1160 dev->stats.rx_frame_errors++;
1161 dev_kfree_skb(skb);
1162 }
1163
1164 /* Unlike mergeable buffers, all buffers are allocated to the
1165 * same size, except for the headroom. For this reason we do
1166 * not need to use mergeable_len_to_ctx here - it is enough
1167 * to store the headroom as the context ignoring the truesize.
1168 */
add_recvbuf_small(struct virtnet_info * vi,struct receive_queue * rq,gfp_t gfp)1169 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1170 gfp_t gfp)
1171 {
1172 struct page_frag *alloc_frag = &rq->alloc_frag;
1173 char *buf;
1174 unsigned int xdp_headroom = virtnet_get_headroom(vi);
1175 void *ctx = (void *)(unsigned long)xdp_headroom;
1176 int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1177 int err;
1178
1179 len = SKB_DATA_ALIGN(len) +
1180 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1181 if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1182 return -ENOMEM;
1183
1184 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1185 get_page(alloc_frag->page);
1186 alloc_frag->offset += len;
1187 sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1188 vi->hdr_len + GOOD_PACKET_LEN);
1189 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1190 if (err < 0)
1191 put_page(virt_to_head_page(buf));
1192 return err;
1193 }
1194
add_recvbuf_big(struct virtnet_info * vi,struct receive_queue * rq,gfp_t gfp)1195 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1196 gfp_t gfp)
1197 {
1198 struct page *first, *list = NULL;
1199 char *p;
1200 int i, err, offset;
1201
1202 sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
1203
1204 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
1205 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
1206 first = get_a_page(rq, gfp);
1207 if (!first) {
1208 if (list)
1209 give_pages(rq, list);
1210 return -ENOMEM;
1211 }
1212 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1213
1214 /* chain new page in list head to match sg */
1215 first->private = (unsigned long)list;
1216 list = first;
1217 }
1218
1219 first = get_a_page(rq, gfp);
1220 if (!first) {
1221 give_pages(rq, list);
1222 return -ENOMEM;
1223 }
1224 p = page_address(first);
1225
1226 /* rq->sg[0], rq->sg[1] share the same page */
1227 /* a separated rq->sg[0] for header - required in case !any_header_sg */
1228 sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1229
1230 /* rq->sg[1] for data packet, from offset */
1231 offset = sizeof(struct padded_vnet_hdr);
1232 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1233
1234 /* chain first in list head */
1235 first->private = (unsigned long)list;
1236 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
1237 first, gfp);
1238 if (err < 0)
1239 give_pages(rq, first);
1240
1241 return err;
1242 }
1243
get_mergeable_buf_len(struct receive_queue * rq,struct ewma_pkt_len * avg_pkt_len,unsigned int room)1244 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1245 struct ewma_pkt_len *avg_pkt_len,
1246 unsigned int room)
1247 {
1248 const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1249 unsigned int len;
1250
1251 if (room)
1252 return PAGE_SIZE - room;
1253
1254 len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1255 rq->min_buf_len, PAGE_SIZE - hdr_len);
1256
1257 return ALIGN(len, L1_CACHE_BYTES);
1258 }
1259
add_recvbuf_mergeable(struct virtnet_info * vi,struct receive_queue * rq,gfp_t gfp)1260 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1261 struct receive_queue *rq, gfp_t gfp)
1262 {
1263 struct page_frag *alloc_frag = &rq->alloc_frag;
1264 unsigned int headroom = virtnet_get_headroom(vi);
1265 unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1266 unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1267 char *buf;
1268 void *ctx;
1269 int err;
1270 unsigned int len, hole;
1271
1272 /* Extra tailroom is needed to satisfy XDP's assumption. This
1273 * means rx frags coalescing won't work, but consider we've
1274 * disabled GSO for XDP, it won't be a big issue.
1275 */
1276 len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1277 if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1278 return -ENOMEM;
1279
1280 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1281 buf += headroom; /* advance address leaving hole at front of pkt */
1282 get_page(alloc_frag->page);
1283 alloc_frag->offset += len + room;
1284 hole = alloc_frag->size - alloc_frag->offset;
1285 if (hole < len + room) {
1286 /* To avoid internal fragmentation, if there is very likely not
1287 * enough space for another buffer, add the remaining space to
1288 * the current buffer.
1289 */
1290 len += hole;
1291 alloc_frag->offset += hole;
1292 }
1293
1294 sg_init_one(rq->sg, buf, len);
1295 ctx = mergeable_len_to_ctx(len, headroom);
1296 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1297 if (err < 0)
1298 put_page(virt_to_head_page(buf));
1299
1300 return err;
1301 }
1302
1303 /*
1304 * Returns false if we couldn't fill entirely (OOM).
1305 *
1306 * Normally run in the receive path, but can also be run from ndo_open
1307 * before we're receiving packets, or from refill_work which is
1308 * careful to disable receiving (using napi_disable).
1309 */
try_fill_recv(struct virtnet_info * vi,struct receive_queue * rq,gfp_t gfp)1310 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1311 gfp_t gfp)
1312 {
1313 int err;
1314 bool oom;
1315
1316 do {
1317 if (vi->mergeable_rx_bufs)
1318 err = add_recvbuf_mergeable(vi, rq, gfp);
1319 else if (vi->big_packets)
1320 err = add_recvbuf_big(vi, rq, gfp);
1321 else
1322 err = add_recvbuf_small(vi, rq, gfp);
1323
1324 oom = err == -ENOMEM;
1325 if (err)
1326 break;
1327 } while (rq->vq->num_free);
1328 if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1329 unsigned long flags;
1330
1331 flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
1332 rq->stats.kicks++;
1333 u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
1334 }
1335
1336 return !oom;
1337 }
1338
skb_recv_done(struct virtqueue * rvq)1339 static void skb_recv_done(struct virtqueue *rvq)
1340 {
1341 struct virtnet_info *vi = rvq->vdev->priv;
1342 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1343
1344 virtqueue_napi_schedule(&rq->napi, rvq);
1345 }
1346
virtnet_napi_enable(struct virtqueue * vq,struct napi_struct * napi)1347 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1348 {
1349 napi_enable(napi);
1350
1351 /* If all buffers were filled by other side before we napi_enabled, we
1352 * won't get another interrupt, so process any outstanding packets now.
1353 * Call local_bh_enable after to trigger softIRQ processing.
1354 */
1355 local_bh_disable();
1356 virtqueue_napi_schedule(napi, vq);
1357 local_bh_enable();
1358 }
1359
virtnet_napi_tx_enable(struct virtnet_info * vi,struct virtqueue * vq,struct napi_struct * napi)1360 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1361 struct virtqueue *vq,
1362 struct napi_struct *napi)
1363 {
1364 if (!napi->weight)
1365 return;
1366
1367 /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1368 * enable the feature if this is likely affine with the transmit path.
1369 */
1370 if (!vi->affinity_hint_set) {
1371 napi->weight = 0;
1372 return;
1373 }
1374
1375 return virtnet_napi_enable(vq, napi);
1376 }
1377
virtnet_napi_tx_disable(struct napi_struct * napi)1378 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1379 {
1380 if (napi->weight)
1381 napi_disable(napi);
1382 }
1383
refill_work(struct work_struct * work)1384 static void refill_work(struct work_struct *work)
1385 {
1386 struct virtnet_info *vi =
1387 container_of(work, struct virtnet_info, refill.work);
1388 bool still_empty;
1389 int i;
1390
1391 for (i = 0; i < vi->curr_queue_pairs; i++) {
1392 struct receive_queue *rq = &vi->rq[i];
1393
1394 napi_disable(&rq->napi);
1395 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1396 virtnet_napi_enable(rq->vq, &rq->napi);
1397
1398 /* In theory, this can happen: if we don't get any buffers in
1399 * we will *never* try to fill again.
1400 */
1401 if (still_empty)
1402 schedule_delayed_work(&vi->refill, HZ/2);
1403 }
1404 }
1405
virtnet_receive(struct receive_queue * rq,int budget,unsigned int * xdp_xmit)1406 static int virtnet_receive(struct receive_queue *rq, int budget,
1407 unsigned int *xdp_xmit)
1408 {
1409 struct virtnet_info *vi = rq->vq->vdev->priv;
1410 struct virtnet_rq_stats stats = {};
1411 unsigned int len;
1412 void *buf;
1413 int i;
1414
1415 if (!vi->big_packets || vi->mergeable_rx_bufs) {
1416 void *ctx;
1417
1418 while (stats.packets < budget &&
1419 (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1420 receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1421 stats.packets++;
1422 }
1423 } else {
1424 while (stats.packets < budget &&
1425 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1426 receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1427 stats.packets++;
1428 }
1429 }
1430
1431 if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1432 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1433 schedule_delayed_work(&vi->refill, 0);
1434 }
1435
1436 u64_stats_update_begin(&rq->stats.syncp);
1437 for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1438 size_t offset = virtnet_rq_stats_desc[i].offset;
1439 u64 *item;
1440
1441 item = (u64 *)((u8 *)&rq->stats + offset);
1442 *item += *(u64 *)((u8 *)&stats + offset);
1443 }
1444 u64_stats_update_end(&rq->stats.syncp);
1445
1446 return stats.packets;
1447 }
1448
free_old_xmit_skbs(struct send_queue * sq,bool in_napi)1449 static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
1450 {
1451 unsigned int len;
1452 unsigned int packets = 0;
1453 unsigned int bytes = 0;
1454 void *ptr;
1455
1456 while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1457 if (likely(!is_xdp_frame(ptr))) {
1458 struct sk_buff *skb = ptr;
1459
1460 pr_debug("Sent skb %p\n", skb);
1461
1462 bytes += skb->len;
1463 napi_consume_skb(skb, in_napi);
1464 } else {
1465 struct xdp_frame *frame = ptr_to_xdp(ptr);
1466
1467 bytes += frame->len;
1468 xdp_return_frame(frame);
1469 }
1470 packets++;
1471 }
1472
1473 /* Avoid overhead when no packets have been processed
1474 * happens when called speculatively from start_xmit.
1475 */
1476 if (!packets)
1477 return;
1478
1479 u64_stats_update_begin(&sq->stats.syncp);
1480 sq->stats.bytes += bytes;
1481 sq->stats.packets += packets;
1482 u64_stats_update_end(&sq->stats.syncp);
1483 }
1484
is_xdp_raw_buffer_queue(struct virtnet_info * vi,int q)1485 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
1486 {
1487 if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
1488 return false;
1489 else if (q < vi->curr_queue_pairs)
1490 return true;
1491 else
1492 return false;
1493 }
1494
virtnet_poll_cleantx(struct receive_queue * rq)1495 static void virtnet_poll_cleantx(struct receive_queue *rq)
1496 {
1497 struct virtnet_info *vi = rq->vq->vdev->priv;
1498 unsigned int index = vq2rxq(rq->vq);
1499 struct send_queue *sq = &vi->sq[index];
1500 struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1501
1502 if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1503 return;
1504
1505 if (__netif_tx_trylock(txq)) {
1506 free_old_xmit_skbs(sq, true);
1507 __netif_tx_unlock(txq);
1508 }
1509
1510 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1511 netif_tx_wake_queue(txq);
1512 }
1513
virtnet_poll(struct napi_struct * napi,int budget)1514 static int virtnet_poll(struct napi_struct *napi, int budget)
1515 {
1516 struct receive_queue *rq =
1517 container_of(napi, struct receive_queue, napi);
1518 struct virtnet_info *vi = rq->vq->vdev->priv;
1519 struct send_queue *sq;
1520 unsigned int received;
1521 unsigned int xdp_xmit = 0;
1522
1523 virtnet_poll_cleantx(rq);
1524
1525 received = virtnet_receive(rq, budget, &xdp_xmit);
1526
1527 /* Out of packets? */
1528 if (received < budget)
1529 virtqueue_napi_complete(napi, rq->vq, received);
1530
1531 if (xdp_xmit & VIRTIO_XDP_REDIR)
1532 xdp_do_flush();
1533
1534 if (xdp_xmit & VIRTIO_XDP_TX) {
1535 sq = virtnet_xdp_get_sq(vi);
1536 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1537 u64_stats_update_begin(&sq->stats.syncp);
1538 sq->stats.kicks++;
1539 u64_stats_update_end(&sq->stats.syncp);
1540 }
1541 virtnet_xdp_put_sq(vi, sq);
1542 }
1543
1544 return received;
1545 }
1546
virtnet_open(struct net_device * dev)1547 static int virtnet_open(struct net_device *dev)
1548 {
1549 struct virtnet_info *vi = netdev_priv(dev);
1550 int i, err;
1551
1552 for (i = 0; i < vi->max_queue_pairs; i++) {
1553 if (i < vi->curr_queue_pairs)
1554 /* Make sure we have some buffers: if oom use wq. */
1555 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1556 schedule_delayed_work(&vi->refill, 0);
1557
1558 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
1559 if (err < 0)
1560 return err;
1561
1562 err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1563 MEM_TYPE_PAGE_SHARED, NULL);
1564 if (err < 0) {
1565 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1566 return err;
1567 }
1568
1569 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1570 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1571 }
1572
1573 return 0;
1574 }
1575
virtnet_poll_tx(struct napi_struct * napi,int budget)1576 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1577 {
1578 struct send_queue *sq = container_of(napi, struct send_queue, napi);
1579 struct virtnet_info *vi = sq->vq->vdev->priv;
1580 unsigned int index = vq2txq(sq->vq);
1581 struct netdev_queue *txq;
1582
1583 if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1584 /* We don't need to enable cb for XDP */
1585 napi_complete_done(napi, 0);
1586 return 0;
1587 }
1588
1589 txq = netdev_get_tx_queue(vi->dev, index);
1590 __netif_tx_lock(txq, raw_smp_processor_id());
1591 free_old_xmit_skbs(sq, true);
1592 __netif_tx_unlock(txq);
1593
1594 virtqueue_napi_complete(napi, sq->vq, 0);
1595
1596 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1597 netif_tx_wake_queue(txq);
1598
1599 return 0;
1600 }
1601
xmit_skb(struct send_queue * sq,struct sk_buff * skb)1602 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1603 {
1604 struct virtio_net_hdr_mrg_rxbuf *hdr;
1605 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1606 struct virtnet_info *vi = sq->vq->vdev->priv;
1607 int num_sg;
1608 unsigned hdr_len = vi->hdr_len;
1609 bool can_push;
1610
1611 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1612
1613 can_push = vi->any_header_sg &&
1614 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1615 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1616 /* Even if we can, don't push here yet as this would skew
1617 * csum_start offset below. */
1618 if (can_push)
1619 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1620 else
1621 hdr = skb_vnet_hdr(skb);
1622
1623 if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1624 virtio_is_little_endian(vi->vdev), false,
1625 0))
1626 BUG();
1627
1628 if (vi->mergeable_rx_bufs)
1629 hdr->num_buffers = 0;
1630
1631 sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1632 if (can_push) {
1633 __skb_push(skb, hdr_len);
1634 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1635 if (unlikely(num_sg < 0))
1636 return num_sg;
1637 /* Pull header back to avoid skew in tx bytes calculations. */
1638 __skb_pull(skb, hdr_len);
1639 } else {
1640 sg_set_buf(sq->sg, hdr, hdr_len);
1641 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1642 if (unlikely(num_sg < 0))
1643 return num_sg;
1644 num_sg++;
1645 }
1646 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1647 }
1648
start_xmit(struct sk_buff * skb,struct net_device * dev)1649 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1650 {
1651 struct virtnet_info *vi = netdev_priv(dev);
1652 int qnum = skb_get_queue_mapping(skb);
1653 struct send_queue *sq = &vi->sq[qnum];
1654 int err;
1655 struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1656 bool kick = !netdev_xmit_more();
1657 bool use_napi = sq->napi.weight;
1658
1659 /* Free up any pending old buffers before queueing new ones. */
1660 free_old_xmit_skbs(sq, false);
1661
1662 if (use_napi && kick)
1663 virtqueue_enable_cb_delayed(sq->vq);
1664
1665 /* timestamp packet in software */
1666 skb_tx_timestamp(skb);
1667
1668 /* Try to transmit */
1669 err = xmit_skb(sq, skb);
1670
1671 /* This should not happen! */
1672 if (unlikely(err)) {
1673 dev->stats.tx_fifo_errors++;
1674 if (net_ratelimit())
1675 dev_warn(&dev->dev,
1676 "Unexpected TXQ (%d) queue failure: %d\n",
1677 qnum, err);
1678 dev->stats.tx_dropped++;
1679 dev_kfree_skb_any(skb);
1680 return NETDEV_TX_OK;
1681 }
1682
1683 /* Don't wait up for transmitted skbs to be freed. */
1684 if (!use_napi) {
1685 skb_orphan(skb);
1686 nf_reset_ct(skb);
1687 }
1688
1689 /* If running out of space, stop queue to avoid getting packets that we
1690 * are then unable to transmit.
1691 * An alternative would be to force queuing layer to requeue the skb by
1692 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1693 * returned in a normal path of operation: it means that driver is not
1694 * maintaining the TX queue stop/start state properly, and causes
1695 * the stack to do a non-trivial amount of useless work.
1696 * Since most packets only take 1 or 2 ring slots, stopping the queue
1697 * early means 16 slots are typically wasted.
1698 */
1699 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1700 netif_stop_subqueue(dev, qnum);
1701 if (!use_napi &&
1702 unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1703 /* More just got used, free them then recheck. */
1704 free_old_xmit_skbs(sq, false);
1705 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1706 netif_start_subqueue(dev, qnum);
1707 virtqueue_disable_cb(sq->vq);
1708 }
1709 }
1710 }
1711
1712 if (kick || netif_xmit_stopped(txq)) {
1713 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1714 u64_stats_update_begin(&sq->stats.syncp);
1715 sq->stats.kicks++;
1716 u64_stats_update_end(&sq->stats.syncp);
1717 }
1718 }
1719
1720 return NETDEV_TX_OK;
1721 }
1722
1723 /*
1724 * Send command via the control virtqueue and check status. Commands
1725 * supported by the hypervisor, as indicated by feature bits, should
1726 * never fail unless improperly formatted.
1727 */
virtnet_send_command(struct virtnet_info * vi,u8 class,u8 cmd,struct scatterlist * out)1728 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1729 struct scatterlist *out)
1730 {
1731 struct scatterlist *sgs[4], hdr, stat;
1732 unsigned out_num = 0, tmp;
1733
1734 /* Caller should know better */
1735 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1736
1737 vi->ctrl->status = ~0;
1738 vi->ctrl->hdr.class = class;
1739 vi->ctrl->hdr.cmd = cmd;
1740 /* Add header */
1741 sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1742 sgs[out_num++] = &hdr;
1743
1744 if (out)
1745 sgs[out_num++] = out;
1746
1747 /* Add return status. */
1748 sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1749 sgs[out_num] = &stat;
1750
1751 BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1752 virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1753
1754 if (unlikely(!virtqueue_kick(vi->cvq)))
1755 return vi->ctrl->status == VIRTIO_NET_OK;
1756
1757 /* Spin for a response, the kick causes an ioport write, trapping
1758 * into the hypervisor, so the request should be handled immediately.
1759 */
1760 while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1761 !virtqueue_is_broken(vi->cvq))
1762 cpu_relax();
1763
1764 return vi->ctrl->status == VIRTIO_NET_OK;
1765 }
1766
virtnet_set_mac_address(struct net_device * dev,void * p)1767 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1768 {
1769 struct virtnet_info *vi = netdev_priv(dev);
1770 struct virtio_device *vdev = vi->vdev;
1771 int ret;
1772 struct sockaddr *addr;
1773 struct scatterlist sg;
1774
1775 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
1776 return -EOPNOTSUPP;
1777
1778 addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1779 if (!addr)
1780 return -ENOMEM;
1781
1782 ret = eth_prepare_mac_addr_change(dev, addr);
1783 if (ret)
1784 goto out;
1785
1786 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1787 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1788 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1789 VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1790 dev_warn(&vdev->dev,
1791 "Failed to set mac address by vq command.\n");
1792 ret = -EINVAL;
1793 goto out;
1794 }
1795 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1796 !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1797 unsigned int i;
1798
1799 /* Naturally, this has an atomicity problem. */
1800 for (i = 0; i < dev->addr_len; i++)
1801 virtio_cwrite8(vdev,
1802 offsetof(struct virtio_net_config, mac) +
1803 i, addr->sa_data[i]);
1804 }
1805
1806 eth_commit_mac_addr_change(dev, p);
1807 ret = 0;
1808
1809 out:
1810 kfree(addr);
1811 return ret;
1812 }
1813
virtnet_stats(struct net_device * dev,struct rtnl_link_stats64 * tot)1814 static void virtnet_stats(struct net_device *dev,
1815 struct rtnl_link_stats64 *tot)
1816 {
1817 struct virtnet_info *vi = netdev_priv(dev);
1818 unsigned int start;
1819 int i;
1820
1821 for (i = 0; i < vi->max_queue_pairs; i++) {
1822 u64 tpackets, tbytes, rpackets, rbytes, rdrops;
1823 struct receive_queue *rq = &vi->rq[i];
1824 struct send_queue *sq = &vi->sq[i];
1825
1826 do {
1827 start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1828 tpackets = sq->stats.packets;
1829 tbytes = sq->stats.bytes;
1830 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1831
1832 do {
1833 start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1834 rpackets = rq->stats.packets;
1835 rbytes = rq->stats.bytes;
1836 rdrops = rq->stats.drops;
1837 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1838
1839 tot->rx_packets += rpackets;
1840 tot->tx_packets += tpackets;
1841 tot->rx_bytes += rbytes;
1842 tot->tx_bytes += tbytes;
1843 tot->rx_dropped += rdrops;
1844 }
1845
1846 tot->tx_dropped = dev->stats.tx_dropped;
1847 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1848 tot->rx_length_errors = dev->stats.rx_length_errors;
1849 tot->rx_frame_errors = dev->stats.rx_frame_errors;
1850 }
1851
virtnet_ack_link_announce(struct virtnet_info * vi)1852 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1853 {
1854 rtnl_lock();
1855 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1856 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1857 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1858 rtnl_unlock();
1859 }
1860
_virtnet_set_queues(struct virtnet_info * vi,u16 queue_pairs)1861 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1862 {
1863 struct scatterlist sg;
1864 struct net_device *dev = vi->dev;
1865
1866 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1867 return 0;
1868
1869 vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1870 sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
1871
1872 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1873 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1874 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1875 queue_pairs);
1876 return -EINVAL;
1877 } else {
1878 vi->curr_queue_pairs = queue_pairs;
1879 /* virtnet_open() will refill when device is going to up. */
1880 if (dev->flags & IFF_UP)
1881 schedule_delayed_work(&vi->refill, 0);
1882 }
1883
1884 return 0;
1885 }
1886
virtnet_set_queues(struct virtnet_info * vi,u16 queue_pairs)1887 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1888 {
1889 int err;
1890
1891 rtnl_lock();
1892 err = _virtnet_set_queues(vi, queue_pairs);
1893 rtnl_unlock();
1894 return err;
1895 }
1896
virtnet_close(struct net_device * dev)1897 static int virtnet_close(struct net_device *dev)
1898 {
1899 struct virtnet_info *vi = netdev_priv(dev);
1900 int i;
1901
1902 /* Make sure refill_work doesn't re-enable napi! */
1903 cancel_delayed_work_sync(&vi->refill);
1904
1905 for (i = 0; i < vi->max_queue_pairs; i++) {
1906 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1907 napi_disable(&vi->rq[i].napi);
1908 virtnet_napi_tx_disable(&vi->sq[i].napi);
1909 }
1910
1911 return 0;
1912 }
1913
virtnet_set_rx_mode(struct net_device * dev)1914 static void virtnet_set_rx_mode(struct net_device *dev)
1915 {
1916 struct virtnet_info *vi = netdev_priv(dev);
1917 struct scatterlist sg[2];
1918 struct virtio_net_ctrl_mac *mac_data;
1919 struct netdev_hw_addr *ha;
1920 int uc_count;
1921 int mc_count;
1922 void *buf;
1923 int i;
1924
1925 /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1926 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1927 return;
1928
1929 vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
1930 vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1931
1932 sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
1933
1934 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1935 VIRTIO_NET_CTRL_RX_PROMISC, sg))
1936 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1937 vi->ctrl->promisc ? "en" : "dis");
1938
1939 sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
1940
1941 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1942 VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1943 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1944 vi->ctrl->allmulti ? "en" : "dis");
1945
1946 uc_count = netdev_uc_count(dev);
1947 mc_count = netdev_mc_count(dev);
1948 /* MAC filter - use one buffer for both lists */
1949 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1950 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1951 mac_data = buf;
1952 if (!buf)
1953 return;
1954
1955 sg_init_table(sg, 2);
1956
1957 /* Store the unicast list and count in the front of the buffer */
1958 mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1959 i = 0;
1960 netdev_for_each_uc_addr(ha, dev)
1961 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1962
1963 sg_set_buf(&sg[0], mac_data,
1964 sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1965
1966 /* multicast list and count fill the end */
1967 mac_data = (void *)&mac_data->macs[uc_count][0];
1968
1969 mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1970 i = 0;
1971 netdev_for_each_mc_addr(ha, dev)
1972 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1973
1974 sg_set_buf(&sg[1], mac_data,
1975 sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1976
1977 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1978 VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1979 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1980
1981 kfree(buf);
1982 }
1983
virtnet_vlan_rx_add_vid(struct net_device * dev,__be16 proto,u16 vid)1984 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1985 __be16 proto, u16 vid)
1986 {
1987 struct virtnet_info *vi = netdev_priv(dev);
1988 struct scatterlist sg;
1989
1990 vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1991 sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1992
1993 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1994 VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1995 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1996 return 0;
1997 }
1998
virtnet_vlan_rx_kill_vid(struct net_device * dev,__be16 proto,u16 vid)1999 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
2000 __be16 proto, u16 vid)
2001 {
2002 struct virtnet_info *vi = netdev_priv(dev);
2003 struct scatterlist sg;
2004
2005 vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2006 sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2007
2008 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2009 VIRTIO_NET_CTRL_VLAN_DEL, &sg))
2010 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
2011 return 0;
2012 }
2013
virtnet_clean_affinity(struct virtnet_info * vi)2014 static void virtnet_clean_affinity(struct virtnet_info *vi)
2015 {
2016 int i;
2017
2018 if (vi->affinity_hint_set) {
2019 for (i = 0; i < vi->max_queue_pairs; i++) {
2020 virtqueue_set_affinity(vi->rq[i].vq, NULL);
2021 virtqueue_set_affinity(vi->sq[i].vq, NULL);
2022 }
2023
2024 vi->affinity_hint_set = false;
2025 }
2026 }
2027
virtnet_set_affinity(struct virtnet_info * vi)2028 static void virtnet_set_affinity(struct virtnet_info *vi)
2029 {
2030 cpumask_var_t mask;
2031 int stragglers;
2032 int group_size;
2033 int i, j, cpu;
2034 int num_cpu;
2035 int stride;
2036
2037 if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
2038 virtnet_clean_affinity(vi);
2039 return;
2040 }
2041
2042 num_cpu = num_online_cpus();
2043 stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
2044 stragglers = num_cpu >= vi->curr_queue_pairs ?
2045 num_cpu % vi->curr_queue_pairs :
2046 0;
2047 cpu = cpumask_next(-1, cpu_online_mask);
2048
2049 for (i = 0; i < vi->curr_queue_pairs; i++) {
2050 group_size = stride + (i < stragglers ? 1 : 0);
2051
2052 for (j = 0; j < group_size; j++) {
2053 cpumask_set_cpu(cpu, mask);
2054 cpu = cpumask_next_wrap(cpu, cpu_online_mask,
2055 nr_cpu_ids, false);
2056 }
2057 virtqueue_set_affinity(vi->rq[i].vq, mask);
2058 virtqueue_set_affinity(vi->sq[i].vq, mask);
2059 __netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, XPS_CPUS);
2060 cpumask_clear(mask);
2061 }
2062
2063 vi->affinity_hint_set = true;
2064 free_cpumask_var(mask);
2065 }
2066
virtnet_cpu_online(unsigned int cpu,struct hlist_node * node)2067 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
2068 {
2069 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2070 node);
2071 virtnet_set_affinity(vi);
2072 return 0;
2073 }
2074
virtnet_cpu_dead(unsigned int cpu,struct hlist_node * node)2075 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
2076 {
2077 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2078 node_dead);
2079 virtnet_set_affinity(vi);
2080 return 0;
2081 }
2082
virtnet_cpu_down_prep(unsigned int cpu,struct hlist_node * node)2083 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
2084 {
2085 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2086 node);
2087
2088 virtnet_clean_affinity(vi);
2089 return 0;
2090 }
2091
2092 static enum cpuhp_state virtionet_online;
2093
virtnet_cpu_notif_add(struct virtnet_info * vi)2094 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
2095 {
2096 int ret;
2097
2098 ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2099 if (ret)
2100 return ret;
2101 ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2102 &vi->node_dead);
2103 if (!ret)
2104 return ret;
2105 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2106 return ret;
2107 }
2108
virtnet_cpu_notif_remove(struct virtnet_info * vi)2109 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2110 {
2111 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2112 cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2113 &vi->node_dead);
2114 }
2115
virtnet_get_ringparam(struct net_device * dev,struct ethtool_ringparam * ring)2116 static void virtnet_get_ringparam(struct net_device *dev,
2117 struct ethtool_ringparam *ring)
2118 {
2119 struct virtnet_info *vi = netdev_priv(dev);
2120
2121 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2122 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2123 ring->rx_pending = ring->rx_max_pending;
2124 ring->tx_pending = ring->tx_max_pending;
2125 }
2126
2127
virtnet_get_drvinfo(struct net_device * dev,struct ethtool_drvinfo * info)2128 static void virtnet_get_drvinfo(struct net_device *dev,
2129 struct ethtool_drvinfo *info)
2130 {
2131 struct virtnet_info *vi = netdev_priv(dev);
2132 struct virtio_device *vdev = vi->vdev;
2133
2134 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2135 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2136 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2137
2138 }
2139
2140 /* TODO: Eliminate OOO packets during switching */
virtnet_set_channels(struct net_device * dev,struct ethtool_channels * channels)2141 static int virtnet_set_channels(struct net_device *dev,
2142 struct ethtool_channels *channels)
2143 {
2144 struct virtnet_info *vi = netdev_priv(dev);
2145 u16 queue_pairs = channels->combined_count;
2146 int err;
2147
2148 /* We don't support separate rx/tx channels.
2149 * We don't allow setting 'other' channels.
2150 */
2151 if (channels->rx_count || channels->tx_count || channels->other_count)
2152 return -EINVAL;
2153
2154 if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2155 return -EINVAL;
2156
2157 /* For now we don't support modifying channels while XDP is loaded
2158 * also when XDP is loaded all RX queues have XDP programs so we only
2159 * need to check a single RX queue.
2160 */
2161 if (vi->rq[0].xdp_prog)
2162 return -EINVAL;
2163
2164 get_online_cpus();
2165 err = _virtnet_set_queues(vi, queue_pairs);
2166 if (err) {
2167 put_online_cpus();
2168 goto err;
2169 }
2170 virtnet_set_affinity(vi);
2171 put_online_cpus();
2172
2173 netif_set_real_num_tx_queues(dev, queue_pairs);
2174 netif_set_real_num_rx_queues(dev, queue_pairs);
2175 err:
2176 return err;
2177 }
2178
virtnet_get_strings(struct net_device * dev,u32 stringset,u8 * data)2179 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2180 {
2181 struct virtnet_info *vi = netdev_priv(dev);
2182 unsigned int i, j;
2183 u8 *p = data;
2184
2185 switch (stringset) {
2186 case ETH_SS_STATS:
2187 for (i = 0; i < vi->curr_queue_pairs; i++) {
2188 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++)
2189 ethtool_sprintf(&p, "rx_queue_%u_%s", i,
2190 virtnet_rq_stats_desc[j].desc);
2191 }
2192
2193 for (i = 0; i < vi->curr_queue_pairs; i++) {
2194 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++)
2195 ethtool_sprintf(&p, "tx_queue_%u_%s", i,
2196 virtnet_sq_stats_desc[j].desc);
2197 }
2198 break;
2199 }
2200 }
2201
virtnet_get_sset_count(struct net_device * dev,int sset)2202 static int virtnet_get_sset_count(struct net_device *dev, int sset)
2203 {
2204 struct virtnet_info *vi = netdev_priv(dev);
2205
2206 switch (sset) {
2207 case ETH_SS_STATS:
2208 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2209 VIRTNET_SQ_STATS_LEN);
2210 default:
2211 return -EOPNOTSUPP;
2212 }
2213 }
2214
virtnet_get_ethtool_stats(struct net_device * dev,struct ethtool_stats * stats,u64 * data)2215 static void virtnet_get_ethtool_stats(struct net_device *dev,
2216 struct ethtool_stats *stats, u64 *data)
2217 {
2218 struct virtnet_info *vi = netdev_priv(dev);
2219 unsigned int idx = 0, start, i, j;
2220 const u8 *stats_base;
2221 size_t offset;
2222
2223 for (i = 0; i < vi->curr_queue_pairs; i++) {
2224 struct receive_queue *rq = &vi->rq[i];
2225
2226 stats_base = (u8 *)&rq->stats;
2227 do {
2228 start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
2229 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2230 offset = virtnet_rq_stats_desc[j].offset;
2231 data[idx + j] = *(u64 *)(stats_base + offset);
2232 }
2233 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
2234 idx += VIRTNET_RQ_STATS_LEN;
2235 }
2236
2237 for (i = 0; i < vi->curr_queue_pairs; i++) {
2238 struct send_queue *sq = &vi->sq[i];
2239
2240 stats_base = (u8 *)&sq->stats;
2241 do {
2242 start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
2243 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2244 offset = virtnet_sq_stats_desc[j].offset;
2245 data[idx + j] = *(u64 *)(stats_base + offset);
2246 }
2247 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
2248 idx += VIRTNET_SQ_STATS_LEN;
2249 }
2250 }
2251
virtnet_get_channels(struct net_device * dev,struct ethtool_channels * channels)2252 static void virtnet_get_channels(struct net_device *dev,
2253 struct ethtool_channels *channels)
2254 {
2255 struct virtnet_info *vi = netdev_priv(dev);
2256
2257 channels->combined_count = vi->curr_queue_pairs;
2258 channels->max_combined = vi->max_queue_pairs;
2259 channels->max_other = 0;
2260 channels->rx_count = 0;
2261 channels->tx_count = 0;
2262 channels->other_count = 0;
2263 }
2264
virtnet_set_link_ksettings(struct net_device * dev,const struct ethtool_link_ksettings * cmd)2265 static int virtnet_set_link_ksettings(struct net_device *dev,
2266 const struct ethtool_link_ksettings *cmd)
2267 {
2268 struct virtnet_info *vi = netdev_priv(dev);
2269
2270 return ethtool_virtdev_set_link_ksettings(dev, cmd,
2271 &vi->speed, &vi->duplex);
2272 }
2273
virtnet_get_link_ksettings(struct net_device * dev,struct ethtool_link_ksettings * cmd)2274 static int virtnet_get_link_ksettings(struct net_device *dev,
2275 struct ethtool_link_ksettings *cmd)
2276 {
2277 struct virtnet_info *vi = netdev_priv(dev);
2278
2279 cmd->base.speed = vi->speed;
2280 cmd->base.duplex = vi->duplex;
2281 cmd->base.port = PORT_OTHER;
2282
2283 return 0;
2284 }
2285
virtnet_set_coalesce(struct net_device * dev,struct ethtool_coalesce * ec)2286 static int virtnet_set_coalesce(struct net_device *dev,
2287 struct ethtool_coalesce *ec)
2288 {
2289 struct virtnet_info *vi = netdev_priv(dev);
2290 int i, napi_weight;
2291
2292 if (ec->tx_max_coalesced_frames > 1 ||
2293 ec->rx_max_coalesced_frames != 1)
2294 return -EINVAL;
2295
2296 napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2297 if (napi_weight ^ vi->sq[0].napi.weight) {
2298 if (dev->flags & IFF_UP)
2299 return -EBUSY;
2300 for (i = 0; i < vi->max_queue_pairs; i++)
2301 vi->sq[i].napi.weight = napi_weight;
2302 }
2303
2304 return 0;
2305 }
2306
virtnet_get_coalesce(struct net_device * dev,struct ethtool_coalesce * ec)2307 static int virtnet_get_coalesce(struct net_device *dev,
2308 struct ethtool_coalesce *ec)
2309 {
2310 struct ethtool_coalesce ec_default = {
2311 .cmd = ETHTOOL_GCOALESCE,
2312 .rx_max_coalesced_frames = 1,
2313 };
2314 struct virtnet_info *vi = netdev_priv(dev);
2315
2316 memcpy(ec, &ec_default, sizeof(ec_default));
2317
2318 if (vi->sq[0].napi.weight)
2319 ec->tx_max_coalesced_frames = 1;
2320
2321 return 0;
2322 }
2323
virtnet_init_settings(struct net_device * dev)2324 static void virtnet_init_settings(struct net_device *dev)
2325 {
2326 struct virtnet_info *vi = netdev_priv(dev);
2327
2328 vi->speed = SPEED_UNKNOWN;
2329 vi->duplex = DUPLEX_UNKNOWN;
2330 }
2331
virtnet_update_settings(struct virtnet_info * vi)2332 static void virtnet_update_settings(struct virtnet_info *vi)
2333 {
2334 u32 speed;
2335 u8 duplex;
2336
2337 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2338 return;
2339
2340 virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
2341
2342 if (ethtool_validate_speed(speed))
2343 vi->speed = speed;
2344
2345 virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
2346
2347 if (ethtool_validate_duplex(duplex))
2348 vi->duplex = duplex;
2349 }
2350
2351 static const struct ethtool_ops virtnet_ethtool_ops = {
2352 .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES,
2353 .get_drvinfo = virtnet_get_drvinfo,
2354 .get_link = ethtool_op_get_link,
2355 .get_ringparam = virtnet_get_ringparam,
2356 .get_strings = virtnet_get_strings,
2357 .get_sset_count = virtnet_get_sset_count,
2358 .get_ethtool_stats = virtnet_get_ethtool_stats,
2359 .set_channels = virtnet_set_channels,
2360 .get_channels = virtnet_get_channels,
2361 .get_ts_info = ethtool_op_get_ts_info,
2362 .get_link_ksettings = virtnet_get_link_ksettings,
2363 .set_link_ksettings = virtnet_set_link_ksettings,
2364 .set_coalesce = virtnet_set_coalesce,
2365 .get_coalesce = virtnet_get_coalesce,
2366 };
2367
virtnet_freeze_down(struct virtio_device * vdev)2368 static void virtnet_freeze_down(struct virtio_device *vdev)
2369 {
2370 struct virtnet_info *vi = vdev->priv;
2371 int i;
2372
2373 /* Make sure no work handler is accessing the device */
2374 flush_work(&vi->config_work);
2375
2376 netif_tx_lock_bh(vi->dev);
2377 netif_device_detach(vi->dev);
2378 netif_tx_unlock_bh(vi->dev);
2379 cancel_delayed_work_sync(&vi->refill);
2380
2381 if (netif_running(vi->dev)) {
2382 for (i = 0; i < vi->max_queue_pairs; i++) {
2383 napi_disable(&vi->rq[i].napi);
2384 virtnet_napi_tx_disable(&vi->sq[i].napi);
2385 }
2386 }
2387 }
2388
2389 static int init_vqs(struct virtnet_info *vi);
2390
virtnet_restore_up(struct virtio_device * vdev)2391 static int virtnet_restore_up(struct virtio_device *vdev)
2392 {
2393 struct virtnet_info *vi = vdev->priv;
2394 int err, i;
2395
2396 err = init_vqs(vi);
2397 if (err)
2398 return err;
2399
2400 virtio_device_ready(vdev);
2401
2402 if (netif_running(vi->dev)) {
2403 for (i = 0; i < vi->curr_queue_pairs; i++)
2404 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2405 schedule_delayed_work(&vi->refill, 0);
2406
2407 for (i = 0; i < vi->max_queue_pairs; i++) {
2408 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2409 virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2410 &vi->sq[i].napi);
2411 }
2412 }
2413
2414 netif_tx_lock_bh(vi->dev);
2415 netif_device_attach(vi->dev);
2416 netif_tx_unlock_bh(vi->dev);
2417 return err;
2418 }
2419
virtnet_set_guest_offloads(struct virtnet_info * vi,u64 offloads)2420 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2421 {
2422 struct scatterlist sg;
2423 vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
2424
2425 sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
2426
2427 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2428 VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2429 dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
2430 return -EINVAL;
2431 }
2432
2433 return 0;
2434 }
2435
virtnet_clear_guest_offloads(struct virtnet_info * vi)2436 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2437 {
2438 u64 offloads = 0;
2439
2440 if (!vi->guest_offloads)
2441 return 0;
2442
2443 return virtnet_set_guest_offloads(vi, offloads);
2444 }
2445
virtnet_restore_guest_offloads(struct virtnet_info * vi)2446 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2447 {
2448 u64 offloads = vi->guest_offloads;
2449
2450 if (!vi->guest_offloads)
2451 return 0;
2452
2453 return virtnet_set_guest_offloads(vi, offloads);
2454 }
2455
virtnet_xdp_set(struct net_device * dev,struct bpf_prog * prog,struct netlink_ext_ack * extack)2456 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2457 struct netlink_ext_ack *extack)
2458 {
2459 unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2460 struct virtnet_info *vi = netdev_priv(dev);
2461 struct bpf_prog *old_prog;
2462 u16 xdp_qp = 0, curr_qp;
2463 int i, err;
2464
2465 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2466 && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2467 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2468 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2469 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
2470 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
2471 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO/CSUM, disable LRO/CSUM first");
2472 return -EOPNOTSUPP;
2473 }
2474
2475 if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2476 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2477 return -EINVAL;
2478 }
2479
2480 if (dev->mtu > max_sz) {
2481 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2482 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2483 return -EINVAL;
2484 }
2485
2486 curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2487 if (prog)
2488 xdp_qp = nr_cpu_ids;
2489
2490 /* XDP requires extra queues for XDP_TX */
2491 if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2492 netdev_warn(dev, "XDP request %i queues but max is %i. XDP_TX and XDP_REDIRECT will operate in a slower locked tx mode.\n",
2493 curr_qp + xdp_qp, vi->max_queue_pairs);
2494 xdp_qp = 0;
2495 }
2496
2497 old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
2498 if (!prog && !old_prog)
2499 return 0;
2500
2501 if (prog)
2502 bpf_prog_add(prog, vi->max_queue_pairs - 1);
2503
2504 /* Make sure NAPI is not using any XDP TX queues for RX. */
2505 if (netif_running(dev)) {
2506 for (i = 0; i < vi->max_queue_pairs; i++) {
2507 napi_disable(&vi->rq[i].napi);
2508 virtnet_napi_tx_disable(&vi->sq[i].napi);
2509 }
2510 }
2511
2512 if (!prog) {
2513 for (i = 0; i < vi->max_queue_pairs; i++) {
2514 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2515 if (i == 0)
2516 virtnet_restore_guest_offloads(vi);
2517 }
2518 synchronize_net();
2519 }
2520
2521 err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2522 if (err)
2523 goto err;
2524 netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2525 vi->xdp_queue_pairs = xdp_qp;
2526
2527 if (prog) {
2528 vi->xdp_enabled = true;
2529 for (i = 0; i < vi->max_queue_pairs; i++) {
2530 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2531 if (i == 0 && !old_prog)
2532 virtnet_clear_guest_offloads(vi);
2533 }
2534 } else {
2535 vi->xdp_enabled = false;
2536 }
2537
2538 for (i = 0; i < vi->max_queue_pairs; i++) {
2539 if (old_prog)
2540 bpf_prog_put(old_prog);
2541 if (netif_running(dev)) {
2542 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2543 virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2544 &vi->sq[i].napi);
2545 }
2546 }
2547
2548 return 0;
2549
2550 err:
2551 if (!prog) {
2552 virtnet_clear_guest_offloads(vi);
2553 for (i = 0; i < vi->max_queue_pairs; i++)
2554 rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
2555 }
2556
2557 if (netif_running(dev)) {
2558 for (i = 0; i < vi->max_queue_pairs; i++) {
2559 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2560 virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2561 &vi->sq[i].napi);
2562 }
2563 }
2564 if (prog)
2565 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2566 return err;
2567 }
2568
virtnet_xdp(struct net_device * dev,struct netdev_bpf * xdp)2569 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2570 {
2571 switch (xdp->command) {
2572 case XDP_SETUP_PROG:
2573 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2574 default:
2575 return -EINVAL;
2576 }
2577 }
2578
virtnet_get_phys_port_name(struct net_device * dev,char * buf,size_t len)2579 static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
2580 size_t len)
2581 {
2582 struct virtnet_info *vi = netdev_priv(dev);
2583 int ret;
2584
2585 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2586 return -EOPNOTSUPP;
2587
2588 ret = snprintf(buf, len, "sby");
2589 if (ret >= len)
2590 return -EOPNOTSUPP;
2591
2592 return 0;
2593 }
2594
virtnet_set_features(struct net_device * dev,netdev_features_t features)2595 static int virtnet_set_features(struct net_device *dev,
2596 netdev_features_t features)
2597 {
2598 struct virtnet_info *vi = netdev_priv(dev);
2599 u64 offloads;
2600 int err;
2601
2602 if ((dev->features ^ features) & NETIF_F_LRO) {
2603 if (vi->xdp_enabled)
2604 return -EBUSY;
2605
2606 if (features & NETIF_F_LRO)
2607 offloads = vi->guest_offloads_capable;
2608 else
2609 offloads = vi->guest_offloads_capable &
2610 ~GUEST_OFFLOAD_LRO_MASK;
2611
2612 err = virtnet_set_guest_offloads(vi, offloads);
2613 if (err)
2614 return err;
2615 vi->guest_offloads = offloads;
2616 }
2617
2618 return 0;
2619 }
2620
2621 static const struct net_device_ops virtnet_netdev = {
2622 .ndo_open = virtnet_open,
2623 .ndo_stop = virtnet_close,
2624 .ndo_start_xmit = start_xmit,
2625 .ndo_validate_addr = eth_validate_addr,
2626 .ndo_set_mac_address = virtnet_set_mac_address,
2627 .ndo_set_rx_mode = virtnet_set_rx_mode,
2628 .ndo_get_stats64 = virtnet_stats,
2629 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2630 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2631 .ndo_bpf = virtnet_xdp,
2632 .ndo_xdp_xmit = virtnet_xdp_xmit,
2633 .ndo_features_check = passthru_features_check,
2634 .ndo_get_phys_port_name = virtnet_get_phys_port_name,
2635 .ndo_set_features = virtnet_set_features,
2636 };
2637
virtnet_config_changed_work(struct work_struct * work)2638 static void virtnet_config_changed_work(struct work_struct *work)
2639 {
2640 struct virtnet_info *vi =
2641 container_of(work, struct virtnet_info, config_work);
2642 u16 v;
2643
2644 if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2645 struct virtio_net_config, status, &v) < 0)
2646 return;
2647
2648 if (v & VIRTIO_NET_S_ANNOUNCE) {
2649 netdev_notify_peers(vi->dev);
2650 virtnet_ack_link_announce(vi);
2651 }
2652
2653 /* Ignore unknown (future) status bits */
2654 v &= VIRTIO_NET_S_LINK_UP;
2655
2656 if (vi->status == v)
2657 return;
2658
2659 vi->status = v;
2660
2661 if (vi->status & VIRTIO_NET_S_LINK_UP) {
2662 virtnet_update_settings(vi);
2663 netif_carrier_on(vi->dev);
2664 netif_tx_wake_all_queues(vi->dev);
2665 } else {
2666 netif_carrier_off(vi->dev);
2667 netif_tx_stop_all_queues(vi->dev);
2668 }
2669 }
2670
virtnet_config_changed(struct virtio_device * vdev)2671 static void virtnet_config_changed(struct virtio_device *vdev)
2672 {
2673 struct virtnet_info *vi = vdev->priv;
2674
2675 schedule_work(&vi->config_work);
2676 }
2677
virtnet_free_queues(struct virtnet_info * vi)2678 static void virtnet_free_queues(struct virtnet_info *vi)
2679 {
2680 int i;
2681
2682 for (i = 0; i < vi->max_queue_pairs; i++) {
2683 __netif_napi_del(&vi->rq[i].napi);
2684 __netif_napi_del(&vi->sq[i].napi);
2685 }
2686
2687 /* We called __netif_napi_del(),
2688 * we need to respect an RCU grace period before freeing vi->rq
2689 */
2690 synchronize_net();
2691
2692 kfree(vi->rq);
2693 kfree(vi->sq);
2694 kfree(vi->ctrl);
2695 }
2696
_free_receive_bufs(struct virtnet_info * vi)2697 static void _free_receive_bufs(struct virtnet_info *vi)
2698 {
2699 struct bpf_prog *old_prog;
2700 int i;
2701
2702 for (i = 0; i < vi->max_queue_pairs; i++) {
2703 while (vi->rq[i].pages)
2704 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2705
2706 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2707 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2708 if (old_prog)
2709 bpf_prog_put(old_prog);
2710 }
2711 }
2712
free_receive_bufs(struct virtnet_info * vi)2713 static void free_receive_bufs(struct virtnet_info *vi)
2714 {
2715 rtnl_lock();
2716 _free_receive_bufs(vi);
2717 rtnl_unlock();
2718 }
2719
free_receive_page_frags(struct virtnet_info * vi)2720 static void free_receive_page_frags(struct virtnet_info *vi)
2721 {
2722 int i;
2723 for (i = 0; i < vi->max_queue_pairs; i++)
2724 if (vi->rq[i].alloc_frag.page)
2725 put_page(vi->rq[i].alloc_frag.page);
2726 }
2727
free_unused_bufs(struct virtnet_info * vi)2728 static void free_unused_bufs(struct virtnet_info *vi)
2729 {
2730 void *buf;
2731 int i;
2732
2733 for (i = 0; i < vi->max_queue_pairs; i++) {
2734 struct virtqueue *vq = vi->sq[i].vq;
2735 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2736 if (!is_xdp_frame(buf))
2737 dev_kfree_skb(buf);
2738 else
2739 xdp_return_frame(ptr_to_xdp(buf));
2740 }
2741 }
2742
2743 for (i = 0; i < vi->max_queue_pairs; i++) {
2744 struct virtqueue *vq = vi->rq[i].vq;
2745
2746 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2747 if (vi->mergeable_rx_bufs) {
2748 put_page(virt_to_head_page(buf));
2749 } else if (vi->big_packets) {
2750 give_pages(&vi->rq[i], buf);
2751 } else {
2752 put_page(virt_to_head_page(buf));
2753 }
2754 }
2755 }
2756 }
2757
virtnet_del_vqs(struct virtnet_info * vi)2758 static void virtnet_del_vqs(struct virtnet_info *vi)
2759 {
2760 struct virtio_device *vdev = vi->vdev;
2761
2762 virtnet_clean_affinity(vi);
2763
2764 vdev->config->del_vqs(vdev);
2765
2766 virtnet_free_queues(vi);
2767 }
2768
2769 /* How large should a single buffer be so a queue full of these can fit at
2770 * least one full packet?
2771 * Logic below assumes the mergeable buffer header is used.
2772 */
mergeable_min_buf_len(struct virtnet_info * vi,struct virtqueue * vq)2773 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2774 {
2775 const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2776 unsigned int rq_size = virtqueue_get_vring_size(vq);
2777 unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2778 unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2779 unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2780
2781 return max(max(min_buf_len, hdr_len) - hdr_len,
2782 (unsigned int)GOOD_PACKET_LEN);
2783 }
2784
virtnet_find_vqs(struct virtnet_info * vi)2785 static int virtnet_find_vqs(struct virtnet_info *vi)
2786 {
2787 vq_callback_t **callbacks;
2788 struct virtqueue **vqs;
2789 int ret = -ENOMEM;
2790 int i, total_vqs;
2791 const char **names;
2792 bool *ctx;
2793
2794 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2795 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2796 * possible control vq.
2797 */
2798 total_vqs = vi->max_queue_pairs * 2 +
2799 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2800
2801 /* Allocate space for find_vqs parameters */
2802 vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
2803 if (!vqs)
2804 goto err_vq;
2805 callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
2806 if (!callbacks)
2807 goto err_callback;
2808 names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
2809 if (!names)
2810 goto err_names;
2811 if (!vi->big_packets || vi->mergeable_rx_bufs) {
2812 ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
2813 if (!ctx)
2814 goto err_ctx;
2815 } else {
2816 ctx = NULL;
2817 }
2818
2819 /* Parameters for control virtqueue, if any */
2820 if (vi->has_cvq) {
2821 callbacks[total_vqs - 1] = NULL;
2822 names[total_vqs - 1] = "control";
2823 }
2824
2825 /* Allocate/initialize parameters for send/receive virtqueues */
2826 for (i = 0; i < vi->max_queue_pairs; i++) {
2827 callbacks[rxq2vq(i)] = skb_recv_done;
2828 callbacks[txq2vq(i)] = skb_xmit_done;
2829 sprintf(vi->rq[i].name, "input.%d", i);
2830 sprintf(vi->sq[i].name, "output.%d", i);
2831 names[rxq2vq(i)] = vi->rq[i].name;
2832 names[txq2vq(i)] = vi->sq[i].name;
2833 if (ctx)
2834 ctx[rxq2vq(i)] = true;
2835 }
2836
2837 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2838 names, ctx, NULL);
2839 if (ret)
2840 goto err_find;
2841
2842 if (vi->has_cvq) {
2843 vi->cvq = vqs[total_vqs - 1];
2844 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2845 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2846 }
2847
2848 for (i = 0; i < vi->max_queue_pairs; i++) {
2849 vi->rq[i].vq = vqs[rxq2vq(i)];
2850 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2851 vi->sq[i].vq = vqs[txq2vq(i)];
2852 }
2853
2854 /* run here: ret == 0. */
2855
2856
2857 err_find:
2858 kfree(ctx);
2859 err_ctx:
2860 kfree(names);
2861 err_names:
2862 kfree(callbacks);
2863 err_callback:
2864 kfree(vqs);
2865 err_vq:
2866 return ret;
2867 }
2868
virtnet_alloc_queues(struct virtnet_info * vi)2869 static int virtnet_alloc_queues(struct virtnet_info *vi)
2870 {
2871 int i;
2872
2873 if (vi->has_cvq) {
2874 vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
2875 if (!vi->ctrl)
2876 goto err_ctrl;
2877 } else {
2878 vi->ctrl = NULL;
2879 }
2880 vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
2881 if (!vi->sq)
2882 goto err_sq;
2883 vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
2884 if (!vi->rq)
2885 goto err_rq;
2886
2887 INIT_DELAYED_WORK(&vi->refill, refill_work);
2888 for (i = 0; i < vi->max_queue_pairs; i++) {
2889 vi->rq[i].pages = NULL;
2890 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2891 napi_weight);
2892 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2893 napi_tx ? napi_weight : 0);
2894
2895 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2896 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2897 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2898
2899 u64_stats_init(&vi->rq[i].stats.syncp);
2900 u64_stats_init(&vi->sq[i].stats.syncp);
2901 }
2902
2903 return 0;
2904
2905 err_rq:
2906 kfree(vi->sq);
2907 err_sq:
2908 kfree(vi->ctrl);
2909 err_ctrl:
2910 return -ENOMEM;
2911 }
2912
init_vqs(struct virtnet_info * vi)2913 static int init_vqs(struct virtnet_info *vi)
2914 {
2915 int ret;
2916
2917 /* Allocate send & receive queues */
2918 ret = virtnet_alloc_queues(vi);
2919 if (ret)
2920 goto err;
2921
2922 ret = virtnet_find_vqs(vi);
2923 if (ret)
2924 goto err_free;
2925
2926 get_online_cpus();
2927 virtnet_set_affinity(vi);
2928 put_online_cpus();
2929
2930 return 0;
2931
2932 err_free:
2933 virtnet_free_queues(vi);
2934 err:
2935 return ret;
2936 }
2937
2938 #ifdef CONFIG_SYSFS
mergeable_rx_buffer_size_show(struct netdev_rx_queue * queue,char * buf)2939 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2940 char *buf)
2941 {
2942 struct virtnet_info *vi = netdev_priv(queue->dev);
2943 unsigned int queue_index = get_netdev_rx_queue_index(queue);
2944 unsigned int headroom = virtnet_get_headroom(vi);
2945 unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
2946 struct ewma_pkt_len *avg;
2947
2948 BUG_ON(queue_index >= vi->max_queue_pairs);
2949 avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2950 return sprintf(buf, "%u\n",
2951 get_mergeable_buf_len(&vi->rq[queue_index], avg,
2952 SKB_DATA_ALIGN(headroom + tailroom)));
2953 }
2954
2955 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2956 __ATTR_RO(mergeable_rx_buffer_size);
2957
2958 static struct attribute *virtio_net_mrg_rx_attrs[] = {
2959 &mergeable_rx_buffer_size_attribute.attr,
2960 NULL
2961 };
2962
2963 static const struct attribute_group virtio_net_mrg_rx_group = {
2964 .name = "virtio_net",
2965 .attrs = virtio_net_mrg_rx_attrs
2966 };
2967 #endif
2968
virtnet_fail_on_feature(struct virtio_device * vdev,unsigned int fbit,const char * fname,const char * dname)2969 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2970 unsigned int fbit,
2971 const char *fname, const char *dname)
2972 {
2973 if (!virtio_has_feature(vdev, fbit))
2974 return false;
2975
2976 dev_err(&vdev->dev, "device advertises feature %s but not %s",
2977 fname, dname);
2978
2979 return true;
2980 }
2981
2982 #define VIRTNET_FAIL_ON(vdev, fbit, dbit) \
2983 virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2984
virtnet_validate_features(struct virtio_device * vdev)2985 static bool virtnet_validate_features(struct virtio_device *vdev)
2986 {
2987 if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2988 (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2989 "VIRTIO_NET_F_CTRL_VQ") ||
2990 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2991 "VIRTIO_NET_F_CTRL_VQ") ||
2992 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2993 "VIRTIO_NET_F_CTRL_VQ") ||
2994 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2995 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2996 "VIRTIO_NET_F_CTRL_VQ"))) {
2997 return false;
2998 }
2999
3000 return true;
3001 }
3002
3003 #define MIN_MTU ETH_MIN_MTU
3004 #define MAX_MTU ETH_MAX_MTU
3005
virtnet_validate(struct virtio_device * vdev)3006 static int virtnet_validate(struct virtio_device *vdev)
3007 {
3008 if (!vdev->config->get) {
3009 dev_err(&vdev->dev, "%s failure: config access disabled\n",
3010 __func__);
3011 return -EINVAL;
3012 }
3013
3014 if (!virtnet_validate_features(vdev))
3015 return -EINVAL;
3016
3017 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3018 int mtu = virtio_cread16(vdev,
3019 offsetof(struct virtio_net_config,
3020 mtu));
3021 if (mtu < MIN_MTU)
3022 __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
3023 }
3024
3025 return 0;
3026 }
3027
virtnet_probe(struct virtio_device * vdev)3028 static int virtnet_probe(struct virtio_device *vdev)
3029 {
3030 int i, err = -ENOMEM;
3031 struct net_device *dev;
3032 struct virtnet_info *vi;
3033 u16 max_queue_pairs;
3034 int mtu;
3035
3036 /* Find if host supports multiqueue virtio_net device */
3037 err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
3038 struct virtio_net_config,
3039 max_virtqueue_pairs, &max_queue_pairs);
3040
3041 /* We need at least 2 queue's */
3042 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
3043 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
3044 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3045 max_queue_pairs = 1;
3046
3047 /* Allocate ourselves a network device with room for our info */
3048 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
3049 if (!dev)
3050 return -ENOMEM;
3051
3052 /* Set up network device as normal. */
3053 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE |
3054 IFF_TX_SKB_NO_LINEAR;
3055 dev->netdev_ops = &virtnet_netdev;
3056 dev->features = NETIF_F_HIGHDMA;
3057
3058 dev->ethtool_ops = &virtnet_ethtool_ops;
3059 SET_NETDEV_DEV(dev, &vdev->dev);
3060
3061 /* Do we support "hardware" checksums? */
3062 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
3063 /* This opens up the world of extra features. */
3064 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3065 if (csum)
3066 dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3067
3068 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
3069 dev->hw_features |= NETIF_F_TSO
3070 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
3071 }
3072 /* Individual feature bits: what can host handle? */
3073 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
3074 dev->hw_features |= NETIF_F_TSO;
3075 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3076 dev->hw_features |= NETIF_F_TSO6;
3077 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3078 dev->hw_features |= NETIF_F_TSO_ECN;
3079
3080 dev->features |= NETIF_F_GSO_ROBUST;
3081
3082 if (gso)
3083 dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3084 /* (!csum && gso) case will be fixed by register_netdev() */
3085 }
3086 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3087 dev->features |= NETIF_F_RXCSUM;
3088 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3089 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3090 dev->features |= NETIF_F_LRO;
3091 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3092 dev->hw_features |= NETIF_F_LRO;
3093
3094 dev->vlan_features = dev->features;
3095
3096 /* MTU range: 68 - 65535 */
3097 dev->min_mtu = MIN_MTU;
3098 dev->max_mtu = MAX_MTU;
3099
3100 /* Configuration may specify what MAC to use. Otherwise random. */
3101 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
3102 virtio_cread_bytes(vdev,
3103 offsetof(struct virtio_net_config, mac),
3104 dev->dev_addr, dev->addr_len);
3105 else
3106 eth_hw_addr_random(dev);
3107
3108 /* Set up our device-specific information */
3109 vi = netdev_priv(dev);
3110 vi->dev = dev;
3111 vi->vdev = vdev;
3112 vdev->priv = vi;
3113
3114 INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3115
3116 /* If we can receive ANY GSO packets, we must allocate large ones. */
3117 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3118 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3119 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
3120 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
3121 vi->big_packets = true;
3122
3123 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
3124 vi->mergeable_rx_bufs = true;
3125
3126 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
3127 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3128 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
3129 else
3130 vi->hdr_len = sizeof(struct virtio_net_hdr);
3131
3132 if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
3133 virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3134 vi->any_header_sg = true;
3135
3136 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3137 vi->has_cvq = true;
3138
3139 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3140 mtu = virtio_cread16(vdev,
3141 offsetof(struct virtio_net_config,
3142 mtu));
3143 if (mtu < dev->min_mtu) {
3144 /* Should never trigger: MTU was previously validated
3145 * in virtnet_validate.
3146 */
3147 dev_err(&vdev->dev,
3148 "device MTU appears to have changed it is now %d < %d",
3149 mtu, dev->min_mtu);
3150 err = -EINVAL;
3151 goto free;
3152 }
3153
3154 dev->mtu = mtu;
3155 dev->max_mtu = mtu;
3156
3157 /* TODO: size buffers correctly in this case. */
3158 if (dev->mtu > ETH_DATA_LEN)
3159 vi->big_packets = true;
3160 }
3161
3162 if (vi->any_header_sg)
3163 dev->needed_headroom = vi->hdr_len;
3164
3165 /* Enable multiqueue by default */
3166 if (num_online_cpus() >= max_queue_pairs)
3167 vi->curr_queue_pairs = max_queue_pairs;
3168 else
3169 vi->curr_queue_pairs = num_online_cpus();
3170 vi->max_queue_pairs = max_queue_pairs;
3171
3172 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
3173 err = init_vqs(vi);
3174 if (err)
3175 goto free;
3176
3177 #ifdef CONFIG_SYSFS
3178 if (vi->mergeable_rx_bufs)
3179 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
3180 #endif
3181 netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
3182 netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
3183
3184 virtnet_init_settings(dev);
3185
3186 if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3187 vi->failover = net_failover_create(vi->dev);
3188 if (IS_ERR(vi->failover)) {
3189 err = PTR_ERR(vi->failover);
3190 goto free_vqs;
3191 }
3192 }
3193
3194 err = register_netdev(dev);
3195 if (err) {
3196 pr_debug("virtio_net: registering device failed\n");
3197 goto free_failover;
3198 }
3199
3200 virtio_device_ready(vdev);
3201
3202 err = virtnet_cpu_notif_add(vi);
3203 if (err) {
3204 pr_debug("virtio_net: registering cpu notifier failed\n");
3205 goto free_unregister_netdev;
3206 }
3207
3208 virtnet_set_queues(vi, vi->curr_queue_pairs);
3209
3210 /* Assume link up if device can't report link status,
3211 otherwise get link status from config. */
3212 netif_carrier_off(dev);
3213 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
3214 schedule_work(&vi->config_work);
3215 } else {
3216 vi->status = VIRTIO_NET_S_LINK_UP;
3217 virtnet_update_settings(vi);
3218 netif_carrier_on(dev);
3219 }
3220
3221 for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
3222 if (virtio_has_feature(vi->vdev, guest_offloads[i]))
3223 set_bit(guest_offloads[i], &vi->guest_offloads);
3224 vi->guest_offloads_capable = vi->guest_offloads;
3225
3226 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
3227 dev->name, max_queue_pairs);
3228
3229 return 0;
3230
3231 free_unregister_netdev:
3232 vi->vdev->config->reset(vdev);
3233
3234 unregister_netdev(dev);
3235 free_failover:
3236 net_failover_destroy(vi->failover);
3237 free_vqs:
3238 cancel_delayed_work_sync(&vi->refill);
3239 free_receive_page_frags(vi);
3240 virtnet_del_vqs(vi);
3241 free:
3242 free_netdev(dev);
3243 return err;
3244 }
3245
remove_vq_common(struct virtnet_info * vi)3246 static void remove_vq_common(struct virtnet_info *vi)
3247 {
3248 vi->vdev->config->reset(vi->vdev);
3249
3250 /* Free unused buffers in both send and recv, if any. */
3251 free_unused_bufs(vi);
3252
3253 free_receive_bufs(vi);
3254
3255 free_receive_page_frags(vi);
3256
3257 virtnet_del_vqs(vi);
3258 }
3259
virtnet_remove(struct virtio_device * vdev)3260 static void virtnet_remove(struct virtio_device *vdev)
3261 {
3262 struct virtnet_info *vi = vdev->priv;
3263
3264 virtnet_cpu_notif_remove(vi);
3265
3266 /* Make sure no work handler is accessing the device. */
3267 flush_work(&vi->config_work);
3268
3269 unregister_netdev(vi->dev);
3270
3271 net_failover_destroy(vi->failover);
3272
3273 remove_vq_common(vi);
3274
3275 free_netdev(vi->dev);
3276 }
3277
virtnet_freeze(struct virtio_device * vdev)3278 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
3279 {
3280 struct virtnet_info *vi = vdev->priv;
3281
3282 virtnet_cpu_notif_remove(vi);
3283 virtnet_freeze_down(vdev);
3284 remove_vq_common(vi);
3285
3286 return 0;
3287 }
3288
virtnet_restore(struct virtio_device * vdev)3289 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
3290 {
3291 struct virtnet_info *vi = vdev->priv;
3292 int err;
3293
3294 err = virtnet_restore_up(vdev);
3295 if (err)
3296 return err;
3297 virtnet_set_queues(vi, vi->curr_queue_pairs);
3298
3299 err = virtnet_cpu_notif_add(vi);
3300 if (err)
3301 return err;
3302
3303 return 0;
3304 }
3305
3306 static struct virtio_device_id id_table[] = {
3307 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
3308 { 0 },
3309 };
3310
3311 #define VIRTNET_FEATURES \
3312 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
3313 VIRTIO_NET_F_MAC, \
3314 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
3315 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
3316 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
3317 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
3318 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
3319 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
3320 VIRTIO_NET_F_CTRL_MAC_ADDR, \
3321 VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
3322 VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
3323
3324 static unsigned int features[] = {
3325 VIRTNET_FEATURES,
3326 };
3327
3328 static unsigned int features_legacy[] = {
3329 VIRTNET_FEATURES,
3330 VIRTIO_NET_F_GSO,
3331 VIRTIO_F_ANY_LAYOUT,
3332 };
3333
3334 static struct virtio_driver virtio_net_driver = {
3335 .feature_table = features,
3336 .feature_table_size = ARRAY_SIZE(features),
3337 .feature_table_legacy = features_legacy,
3338 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
3339 .driver.name = KBUILD_MODNAME,
3340 .driver.owner = THIS_MODULE,
3341 .id_table = id_table,
3342 .validate = virtnet_validate,
3343 .probe = virtnet_probe,
3344 .remove = virtnet_remove,
3345 .config_changed = virtnet_config_changed,
3346 #ifdef CONFIG_PM_SLEEP
3347 .freeze = virtnet_freeze,
3348 .restore = virtnet_restore,
3349 #endif
3350 };
3351
virtio_net_driver_init(void)3352 static __init int virtio_net_driver_init(void)
3353 {
3354 int ret;
3355
3356 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
3357 virtnet_cpu_online,
3358 virtnet_cpu_down_prep);
3359 if (ret < 0)
3360 goto out;
3361 virtionet_online = ret;
3362 ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
3363 NULL, virtnet_cpu_dead);
3364 if (ret)
3365 goto err_dead;
3366
3367 ret = register_virtio_driver(&virtio_net_driver);
3368 if (ret)
3369 goto err_virtio;
3370 return 0;
3371 err_virtio:
3372 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3373 err_dead:
3374 cpuhp_remove_multi_state(virtionet_online);
3375 out:
3376 return ret;
3377 }
3378 module_init(virtio_net_driver_init);
3379
virtio_net_driver_exit(void)3380 static __exit void virtio_net_driver_exit(void)
3381 {
3382 unregister_virtio_driver(&virtio_net_driver);
3383 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3384 cpuhp_remove_multi_state(virtionet_online);
3385 }
3386 module_exit(virtio_net_driver_exit);
3387
3388 MODULE_DEVICE_TABLE(virtio, id_table);
3389 MODULE_DESCRIPTION("Virtio network driver");
3390 MODULE_LICENSE("GPL");
3391