1 /* A network driver using virtio. 2 * 3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, see <http://www.gnu.org/licenses/>. 17 */ 18 //#define DEBUG 19 #include <linux/netdevice.h> 20 #include <linux/etherdevice.h> 21 #include <linux/ethtool.h> 22 #include <linux/module.h> 23 #include <linux/virtio.h> 24 #include <linux/virtio_net.h> 25 #include <linux/bpf.h> 26 #include <linux/bpf_trace.h> 27 #include <linux/scatterlist.h> 28 #include <linux/if_vlan.h> 29 #include <linux/slab.h> 30 #include <linux/cpu.h> 31 #include <linux/average.h> 32 #include <linux/filter.h> 33 #include <net/route.h> 34 #include <net/xdp.h> 35 36 static int napi_weight = NAPI_POLL_WEIGHT; 37 module_param(napi_weight, int, 0444); 38 39 static bool csum = true, gso = true, napi_tx; 40 module_param(csum, bool, 0444); 41 module_param(gso, bool, 0444); 42 module_param(napi_tx, bool, 0644); 43 44 /* FIXME: MTU in config. */ 45 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 46 #define GOOD_COPY_LEN 128 47 48 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD) 49 50 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */ 51 #define VIRTIO_XDP_HEADROOM 256 52 53 /* RX packet size EWMA. The average packet size is used to determine the packet 54 * buffer size when refilling RX rings. As the entire RX ring may be refilled 55 * at once, the weight is chosen so that the EWMA will be insensitive to short- 56 * term, transient changes in packet size. 57 */ 58 DECLARE_EWMA(pkt_len, 0, 64) 59 60 #define VIRTNET_DRIVER_VERSION "1.0.0" 61 62 static const unsigned long guest_offloads[] = { 63 VIRTIO_NET_F_GUEST_TSO4, 64 VIRTIO_NET_F_GUEST_TSO6, 65 VIRTIO_NET_F_GUEST_ECN, 66 VIRTIO_NET_F_GUEST_UFO 67 }; 68 69 struct virtnet_stat_desc { 70 char desc[ETH_GSTRING_LEN]; 71 size_t offset; 72 }; 73 74 struct virtnet_sq_stats { 75 struct u64_stats_sync syncp; 76 u64 packets; 77 u64 bytes; 78 }; 79 80 struct virtnet_rq_stats { 81 struct u64_stats_sync syncp; 82 u64 packets; 83 u64 bytes; 84 }; 85 86 #define VIRTNET_SQ_STAT(m) offsetof(struct virtnet_sq_stats, m) 87 #define VIRTNET_RQ_STAT(m) offsetof(struct virtnet_rq_stats, m) 88 89 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = { 90 { "packets", VIRTNET_SQ_STAT(packets) }, 91 { "bytes", VIRTNET_SQ_STAT(bytes) }, 92 }; 93 94 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = { 95 { "packets", VIRTNET_RQ_STAT(packets) }, 96 { "bytes", VIRTNET_RQ_STAT(bytes) }, 97 }; 98 99 #define VIRTNET_SQ_STATS_LEN ARRAY_SIZE(virtnet_sq_stats_desc) 100 #define VIRTNET_RQ_STATS_LEN ARRAY_SIZE(virtnet_rq_stats_desc) 101 102 /* Internal representation of a send virtqueue */ 103 struct send_queue { 104 /* Virtqueue associated with this send _queue */ 105 struct virtqueue *vq; 106 107 /* TX: fragments + linear part + virtio header */ 108 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 109 110 /* Name of the send queue: output.$index */ 111 char name[40]; 112 113 struct virtnet_sq_stats stats; 114 115 struct napi_struct napi; 116 }; 117 118 /* Internal representation of a receive virtqueue */ 119 struct receive_queue { 120 /* Virtqueue associated with this receive_queue */ 121 struct virtqueue *vq; 122 123 struct napi_struct napi; 124 125 struct bpf_prog __rcu *xdp_prog; 126 127 struct virtnet_rq_stats stats; 128 129 /* Chain pages by the private ptr. */ 130 struct page *pages; 131 132 /* Average packet length for mergeable receive buffers. */ 133 struct ewma_pkt_len mrg_avg_pkt_len; 134 135 /* Page frag for packet buffer allocation. */ 136 struct page_frag alloc_frag; 137 138 /* RX: fragments + linear part + virtio header */ 139 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 140 141 /* Min single buffer size for mergeable buffers case. */ 142 unsigned int min_buf_len; 143 144 /* Name of this receive queue: input.$index */ 145 char name[40]; 146 147 struct xdp_rxq_info xdp_rxq; 148 }; 149 150 struct virtnet_info { 151 struct virtio_device *vdev; 152 struct virtqueue *cvq; 153 struct net_device *dev; 154 struct send_queue *sq; 155 struct receive_queue *rq; 156 unsigned int status; 157 158 /* Max # of queue pairs supported by the device */ 159 u16 max_queue_pairs; 160 161 /* # of queue pairs currently used by the driver */ 162 u16 curr_queue_pairs; 163 164 /* # of XDP queue pairs currently used by the driver */ 165 u16 xdp_queue_pairs; 166 167 /* I like... big packets and I cannot lie! */ 168 bool big_packets; 169 170 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 171 bool mergeable_rx_bufs; 172 173 /* Has control virtqueue */ 174 bool has_cvq; 175 176 /* Host can handle any s/g split between our header and packet data */ 177 bool any_header_sg; 178 179 /* Packet virtio header size */ 180 u8 hdr_len; 181 182 /* Work struct for refilling if we run low on memory. */ 183 struct delayed_work refill; 184 185 /* Work struct for config space updates */ 186 struct work_struct config_work; 187 188 /* Does the affinity hint is set for virtqueues? */ 189 bool affinity_hint_set; 190 191 /* CPU hotplug instances for online & dead */ 192 struct hlist_node node; 193 struct hlist_node node_dead; 194 195 /* Control VQ buffers: protected by the rtnl lock */ 196 struct virtio_net_ctrl_hdr ctrl_hdr; 197 virtio_net_ctrl_ack ctrl_status; 198 struct virtio_net_ctrl_mq ctrl_mq; 199 u8 ctrl_promisc; 200 u8 ctrl_allmulti; 201 u16 ctrl_vid; 202 u64 ctrl_offloads; 203 204 /* Ethtool settings */ 205 u8 duplex; 206 u32 speed; 207 208 unsigned long guest_offloads; 209 }; 210 211 struct padded_vnet_hdr { 212 struct virtio_net_hdr_mrg_rxbuf hdr; 213 /* 214 * hdr is in a separate sg buffer, and data sg buffer shares same page 215 * with this header sg. This padding makes next sg 16 byte aligned 216 * after the header. 217 */ 218 char padding[4]; 219 }; 220 221 /* Converting between virtqueue no. and kernel tx/rx queue no. 222 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq 223 */ 224 static int vq2txq(struct virtqueue *vq) 225 { 226 return (vq->index - 1) / 2; 227 } 228 229 static int txq2vq(int txq) 230 { 231 return txq * 2 + 1; 232 } 233 234 static int vq2rxq(struct virtqueue *vq) 235 { 236 return vq->index / 2; 237 } 238 239 static int rxq2vq(int rxq) 240 { 241 return rxq * 2; 242 } 243 244 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb) 245 { 246 return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb; 247 } 248 249 /* 250 * private is used to chain pages for big packets, put the whole 251 * most recent used list in the beginning for reuse 252 */ 253 static void give_pages(struct receive_queue *rq, struct page *page) 254 { 255 struct page *end; 256 257 /* Find end of list, sew whole thing into vi->rq.pages. */ 258 for (end = page; end->private; end = (struct page *)end->private); 259 end->private = (unsigned long)rq->pages; 260 rq->pages = page; 261 } 262 263 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) 264 { 265 struct page *p = rq->pages; 266 267 if (p) { 268 rq->pages = (struct page *)p->private; 269 /* clear private here, it is used to chain pages */ 270 p->private = 0; 271 } else 272 p = alloc_page(gfp_mask); 273 return p; 274 } 275 276 static void virtqueue_napi_schedule(struct napi_struct *napi, 277 struct virtqueue *vq) 278 { 279 if (napi_schedule_prep(napi)) { 280 virtqueue_disable_cb(vq); 281 __napi_schedule(napi); 282 } 283 } 284 285 static void virtqueue_napi_complete(struct napi_struct *napi, 286 struct virtqueue *vq, int processed) 287 { 288 int opaque; 289 290 opaque = virtqueue_enable_cb_prepare(vq); 291 if (napi_complete_done(napi, processed)) { 292 if (unlikely(virtqueue_poll(vq, opaque))) 293 virtqueue_napi_schedule(napi, vq); 294 } else { 295 virtqueue_disable_cb(vq); 296 } 297 } 298 299 static void skb_xmit_done(struct virtqueue *vq) 300 { 301 struct virtnet_info *vi = vq->vdev->priv; 302 struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi; 303 304 /* Suppress further interrupts. */ 305 virtqueue_disable_cb(vq); 306 307 if (napi->weight) 308 virtqueue_napi_schedule(napi, vq); 309 else 310 /* We were probably waiting for more output buffers. */ 311 netif_wake_subqueue(vi->dev, vq2txq(vq)); 312 } 313 314 #define MRG_CTX_HEADER_SHIFT 22 315 static void *mergeable_len_to_ctx(unsigned int truesize, 316 unsigned int headroom) 317 { 318 return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize); 319 } 320 321 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx) 322 { 323 return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT; 324 } 325 326 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx) 327 { 328 return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1); 329 } 330 331 /* Called from bottom half context */ 332 static struct sk_buff *page_to_skb(struct virtnet_info *vi, 333 struct receive_queue *rq, 334 struct page *page, unsigned int offset, 335 unsigned int len, unsigned int truesize) 336 { 337 struct sk_buff *skb; 338 struct virtio_net_hdr_mrg_rxbuf *hdr; 339 unsigned int copy, hdr_len, hdr_padded_len; 340 char *p; 341 342 p = page_address(page) + offset; 343 344 /* copy small packet so we can reuse these pages for small data */ 345 skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN); 346 if (unlikely(!skb)) 347 return NULL; 348 349 hdr = skb_vnet_hdr(skb); 350 351 hdr_len = vi->hdr_len; 352 if (vi->mergeable_rx_bufs) 353 hdr_padded_len = sizeof(*hdr); 354 else 355 hdr_padded_len = sizeof(struct padded_vnet_hdr); 356 357 memcpy(hdr, p, hdr_len); 358 359 len -= hdr_len; 360 offset += hdr_padded_len; 361 p += hdr_padded_len; 362 363 copy = len; 364 if (copy > skb_tailroom(skb)) 365 copy = skb_tailroom(skb); 366 skb_put_data(skb, p, copy); 367 368 len -= copy; 369 offset += copy; 370 371 if (vi->mergeable_rx_bufs) { 372 if (len) 373 skb_add_rx_frag(skb, 0, page, offset, len, truesize); 374 else 375 put_page(page); 376 return skb; 377 } 378 379 /* 380 * Verify that we can indeed put this data into a skb. 381 * This is here to handle cases when the device erroneously 382 * tries to receive more than is possible. This is usually 383 * the case of a broken device. 384 */ 385 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 386 net_dbg_ratelimited("%s: too much data\n", skb->dev->name); 387 dev_kfree_skb(skb); 388 return NULL; 389 } 390 BUG_ON(offset >= PAGE_SIZE); 391 while (len) { 392 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len); 393 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset, 394 frag_size, truesize); 395 len -= frag_size; 396 page = (struct page *)page->private; 397 offset = 0; 398 } 399 400 if (page) 401 give_pages(rq, page); 402 403 return skb; 404 } 405 406 static void virtnet_xdp_flush(struct net_device *dev) 407 { 408 struct virtnet_info *vi = netdev_priv(dev); 409 struct send_queue *sq; 410 unsigned int qp; 411 412 qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id(); 413 sq = &vi->sq[qp]; 414 415 virtqueue_kick(sq->vq); 416 } 417 418 static int __virtnet_xdp_xmit(struct virtnet_info *vi, 419 struct xdp_buff *xdp) 420 { 421 struct virtio_net_hdr_mrg_rxbuf *hdr; 422 struct xdp_frame *xdpf, *xdpf_sent; 423 struct send_queue *sq; 424 unsigned int len; 425 unsigned int qp; 426 int err; 427 428 qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id(); 429 sq = &vi->sq[qp]; 430 431 /* Free up any pending old buffers before queueing new ones. */ 432 while ((xdpf_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) 433 xdp_return_frame(xdpf_sent->data, &xdpf_sent->mem); 434 435 xdpf = convert_to_xdp_frame(xdp); 436 if (unlikely(!xdpf)) 437 return -EOVERFLOW; 438 439 /* virtqueue want to use data area in-front of packet */ 440 if (unlikely(xdpf->metasize > 0)) 441 return -EOPNOTSUPP; 442 443 if (unlikely(xdpf->headroom < vi->hdr_len)) 444 return -EOVERFLOW; 445 446 /* Make room for virtqueue hdr (also change xdpf->headroom?) */ 447 xdpf->data -= vi->hdr_len; 448 /* Zero header and leave csum up to XDP layers */ 449 hdr = xdpf->data; 450 memset(hdr, 0, vi->hdr_len); 451 xdpf->len += vi->hdr_len; 452 453 sg_init_one(sq->sg, xdpf->data, xdpf->len); 454 455 err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdpf, GFP_ATOMIC); 456 if (unlikely(err)) 457 return -ENOSPC; /* Caller handle free/refcnt */ 458 459 return 0; 460 } 461 462 static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp) 463 { 464 struct virtnet_info *vi = netdev_priv(dev); 465 struct receive_queue *rq = vi->rq; 466 struct bpf_prog *xdp_prog; 467 468 /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this 469 * indicate XDP resources have been successfully allocated. 470 */ 471 xdp_prog = rcu_dereference(rq->xdp_prog); 472 if (!xdp_prog) 473 return -ENXIO; 474 475 return __virtnet_xdp_xmit(vi, xdp); 476 } 477 478 static unsigned int virtnet_get_headroom(struct virtnet_info *vi) 479 { 480 return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0; 481 } 482 483 /* We copy the packet for XDP in the following cases: 484 * 485 * 1) Packet is scattered across multiple rx buffers. 486 * 2) Headroom space is insufficient. 487 * 488 * This is inefficient but it's a temporary condition that 489 * we hit right after XDP is enabled and until queue is refilled 490 * with large buffers with sufficient headroom - so it should affect 491 * at most queue size packets. 492 * Afterwards, the conditions to enable 493 * XDP should preclude the underlying device from sending packets 494 * across multiple buffers (num_buf > 1), and we make sure buffers 495 * have enough headroom. 496 */ 497 static struct page *xdp_linearize_page(struct receive_queue *rq, 498 u16 *num_buf, 499 struct page *p, 500 int offset, 501 int page_off, 502 unsigned int *len) 503 { 504 struct page *page = alloc_page(GFP_ATOMIC); 505 506 if (!page) 507 return NULL; 508 509 memcpy(page_address(page) + page_off, page_address(p) + offset, *len); 510 page_off += *len; 511 512 while (--*num_buf) { 513 int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 514 unsigned int buflen; 515 void *buf; 516 int off; 517 518 buf = virtqueue_get_buf(rq->vq, &buflen); 519 if (unlikely(!buf)) 520 goto err_buf; 521 522 p = virt_to_head_page(buf); 523 off = buf - page_address(p); 524 525 /* guard against a misconfigured or uncooperative backend that 526 * is sending packet larger than the MTU. 527 */ 528 if ((page_off + buflen + tailroom) > PAGE_SIZE) { 529 put_page(p); 530 goto err_buf; 531 } 532 533 memcpy(page_address(page) + page_off, 534 page_address(p) + off, buflen); 535 page_off += buflen; 536 put_page(p); 537 } 538 539 /* Headroom does not contribute to packet length */ 540 *len = page_off - VIRTIO_XDP_HEADROOM; 541 return page; 542 err_buf: 543 __free_pages(page, 0); 544 return NULL; 545 } 546 547 static struct sk_buff *receive_small(struct net_device *dev, 548 struct virtnet_info *vi, 549 struct receive_queue *rq, 550 void *buf, void *ctx, 551 unsigned int len, 552 bool *xdp_xmit) 553 { 554 struct sk_buff *skb; 555 struct bpf_prog *xdp_prog; 556 unsigned int xdp_headroom = (unsigned long)ctx; 557 unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom; 558 unsigned int headroom = vi->hdr_len + header_offset; 559 unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + 560 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 561 struct page *page = virt_to_head_page(buf); 562 unsigned int delta = 0; 563 struct page *xdp_page; 564 int err; 565 566 len -= vi->hdr_len; 567 568 rcu_read_lock(); 569 xdp_prog = rcu_dereference(rq->xdp_prog); 570 if (xdp_prog) { 571 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; 572 struct xdp_buff xdp; 573 void *orig_data; 574 u32 act; 575 576 if (unlikely(hdr->hdr.gso_type)) 577 goto err_xdp; 578 579 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) { 580 int offset = buf - page_address(page) + header_offset; 581 unsigned int tlen = len + vi->hdr_len; 582 u16 num_buf = 1; 583 584 xdp_headroom = virtnet_get_headroom(vi); 585 header_offset = VIRTNET_RX_PAD + xdp_headroom; 586 headroom = vi->hdr_len + header_offset; 587 buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + 588 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 589 xdp_page = xdp_linearize_page(rq, &num_buf, page, 590 offset, header_offset, 591 &tlen); 592 if (!xdp_page) 593 goto err_xdp; 594 595 buf = page_address(xdp_page); 596 put_page(page); 597 page = xdp_page; 598 } 599 600 xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len; 601 xdp.data = xdp.data_hard_start + xdp_headroom; 602 xdp_set_data_meta_invalid(&xdp); 603 xdp.data_end = xdp.data + len; 604 xdp.rxq = &rq->xdp_rxq; 605 orig_data = xdp.data; 606 act = bpf_prog_run_xdp(xdp_prog, &xdp); 607 608 switch (act) { 609 case XDP_PASS: 610 /* Recalculate length in case bpf program changed it */ 611 delta = orig_data - xdp.data; 612 break; 613 case XDP_TX: 614 err = __virtnet_xdp_xmit(vi, &xdp); 615 if (unlikely(err)) { 616 trace_xdp_exception(vi->dev, xdp_prog, act); 617 goto err_xdp; 618 } 619 *xdp_xmit = true; 620 rcu_read_unlock(); 621 goto xdp_xmit; 622 case XDP_REDIRECT: 623 err = xdp_do_redirect(dev, &xdp, xdp_prog); 624 if (err) 625 goto err_xdp; 626 *xdp_xmit = true; 627 rcu_read_unlock(); 628 goto xdp_xmit; 629 default: 630 bpf_warn_invalid_xdp_action(act); 631 case XDP_ABORTED: 632 trace_xdp_exception(vi->dev, xdp_prog, act); 633 case XDP_DROP: 634 goto err_xdp; 635 } 636 } 637 rcu_read_unlock(); 638 639 skb = build_skb(buf, buflen); 640 if (!skb) { 641 put_page(page); 642 goto err; 643 } 644 skb_reserve(skb, headroom - delta); 645 skb_put(skb, len + delta); 646 if (!delta) { 647 buf += header_offset; 648 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); 649 } /* keep zeroed vnet hdr since packet was changed by bpf */ 650 651 err: 652 return skb; 653 654 err_xdp: 655 rcu_read_unlock(); 656 dev->stats.rx_dropped++; 657 put_page(page); 658 xdp_xmit: 659 return NULL; 660 } 661 662 static struct sk_buff *receive_big(struct net_device *dev, 663 struct virtnet_info *vi, 664 struct receive_queue *rq, 665 void *buf, 666 unsigned int len) 667 { 668 struct page *page = buf; 669 struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE); 670 671 if (unlikely(!skb)) 672 goto err; 673 674 return skb; 675 676 err: 677 dev->stats.rx_dropped++; 678 give_pages(rq, page); 679 return NULL; 680 } 681 682 static struct sk_buff *receive_mergeable(struct net_device *dev, 683 struct virtnet_info *vi, 684 struct receive_queue *rq, 685 void *buf, 686 void *ctx, 687 unsigned int len, 688 bool *xdp_xmit) 689 { 690 struct virtio_net_hdr_mrg_rxbuf *hdr = buf; 691 u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers); 692 struct page *page = virt_to_head_page(buf); 693 int offset = buf - page_address(page); 694 struct sk_buff *head_skb, *curr_skb; 695 struct bpf_prog *xdp_prog; 696 unsigned int truesize; 697 unsigned int headroom = mergeable_ctx_to_headroom(ctx); 698 int err; 699 700 head_skb = NULL; 701 702 rcu_read_lock(); 703 xdp_prog = rcu_dereference(rq->xdp_prog); 704 if (xdp_prog) { 705 struct page *xdp_page; 706 struct xdp_buff xdp; 707 void *data; 708 u32 act; 709 710 /* This happens when rx buffer size is underestimated 711 * or headroom is not enough because of the buffer 712 * was refilled before XDP is set. This should only 713 * happen for the first several packets, so we don't 714 * care much about its performance. 715 */ 716 if (unlikely(num_buf > 1 || 717 headroom < virtnet_get_headroom(vi))) { 718 /* linearize data for XDP */ 719 xdp_page = xdp_linearize_page(rq, &num_buf, 720 page, offset, 721 VIRTIO_XDP_HEADROOM, 722 &len); 723 if (!xdp_page) 724 goto err_xdp; 725 offset = VIRTIO_XDP_HEADROOM; 726 } else { 727 xdp_page = page; 728 } 729 730 /* Transient failure which in theory could occur if 731 * in-flight packets from before XDP was enabled reach 732 * the receive path after XDP is loaded. In practice I 733 * was not able to create this condition. 734 */ 735 if (unlikely(hdr->hdr.gso_type)) 736 goto err_xdp; 737 738 /* Allow consuming headroom but reserve enough space to push 739 * the descriptor on if we get an XDP_TX return code. 740 */ 741 data = page_address(xdp_page) + offset; 742 xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len; 743 xdp.data = data + vi->hdr_len; 744 xdp_set_data_meta_invalid(&xdp); 745 xdp.data_end = xdp.data + (len - vi->hdr_len); 746 xdp.rxq = &rq->xdp_rxq; 747 748 act = bpf_prog_run_xdp(xdp_prog, &xdp); 749 750 switch (act) { 751 case XDP_PASS: 752 /* recalculate offset to account for any header 753 * adjustments. Note other cases do not build an 754 * skb and avoid using offset 755 */ 756 offset = xdp.data - 757 page_address(xdp_page) - vi->hdr_len; 758 759 /* We can only create skb based on xdp_page. */ 760 if (unlikely(xdp_page != page)) { 761 rcu_read_unlock(); 762 put_page(page); 763 head_skb = page_to_skb(vi, rq, xdp_page, 764 offset, len, PAGE_SIZE); 765 return head_skb; 766 } 767 break; 768 case XDP_TX: 769 err = __virtnet_xdp_xmit(vi, &xdp); 770 if (unlikely(err)) { 771 trace_xdp_exception(vi->dev, xdp_prog, act); 772 if (unlikely(xdp_page != page)) 773 put_page(xdp_page); 774 goto err_xdp; 775 } 776 *xdp_xmit = true; 777 if (unlikely(xdp_page != page)) 778 goto err_xdp; 779 rcu_read_unlock(); 780 goto xdp_xmit; 781 case XDP_REDIRECT: 782 err = xdp_do_redirect(dev, &xdp, xdp_prog); 783 if (err) { 784 if (unlikely(xdp_page != page)) 785 put_page(xdp_page); 786 goto err_xdp; 787 } 788 *xdp_xmit = true; 789 if (unlikely(xdp_page != page)) 790 goto err_xdp; 791 rcu_read_unlock(); 792 goto xdp_xmit; 793 default: 794 bpf_warn_invalid_xdp_action(act); 795 case XDP_ABORTED: 796 trace_xdp_exception(vi->dev, xdp_prog, act); 797 case XDP_DROP: 798 if (unlikely(xdp_page != page)) 799 __free_pages(xdp_page, 0); 800 goto err_xdp; 801 } 802 } 803 rcu_read_unlock(); 804 805 truesize = mergeable_ctx_to_truesize(ctx); 806 if (unlikely(len > truesize)) { 807 pr_debug("%s: rx error: len %u exceeds truesize %lu\n", 808 dev->name, len, (unsigned long)ctx); 809 dev->stats.rx_length_errors++; 810 goto err_skb; 811 } 812 813 head_skb = page_to_skb(vi, rq, page, offset, len, truesize); 814 curr_skb = head_skb; 815 816 if (unlikely(!curr_skb)) 817 goto err_skb; 818 while (--num_buf) { 819 int num_skb_frags; 820 821 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx); 822 if (unlikely(!buf)) { 823 pr_debug("%s: rx error: %d buffers out of %d missing\n", 824 dev->name, num_buf, 825 virtio16_to_cpu(vi->vdev, 826 hdr->num_buffers)); 827 dev->stats.rx_length_errors++; 828 goto err_buf; 829 } 830 831 page = virt_to_head_page(buf); 832 833 truesize = mergeable_ctx_to_truesize(ctx); 834 if (unlikely(len > truesize)) { 835 pr_debug("%s: rx error: len %u exceeds truesize %lu\n", 836 dev->name, len, (unsigned long)ctx); 837 dev->stats.rx_length_errors++; 838 goto err_skb; 839 } 840 841 num_skb_frags = skb_shinfo(curr_skb)->nr_frags; 842 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) { 843 struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC); 844 845 if (unlikely(!nskb)) 846 goto err_skb; 847 if (curr_skb == head_skb) 848 skb_shinfo(curr_skb)->frag_list = nskb; 849 else 850 curr_skb->next = nskb; 851 curr_skb = nskb; 852 head_skb->truesize += nskb->truesize; 853 num_skb_frags = 0; 854 } 855 if (curr_skb != head_skb) { 856 head_skb->data_len += len; 857 head_skb->len += len; 858 head_skb->truesize += truesize; 859 } 860 offset = buf - page_address(page); 861 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) { 862 put_page(page); 863 skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1, 864 len, truesize); 865 } else { 866 skb_add_rx_frag(curr_skb, num_skb_frags, page, 867 offset, len, truesize); 868 } 869 } 870 871 ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len); 872 return head_skb; 873 874 err_xdp: 875 rcu_read_unlock(); 876 err_skb: 877 put_page(page); 878 while (--num_buf) { 879 buf = virtqueue_get_buf(rq->vq, &len); 880 if (unlikely(!buf)) { 881 pr_debug("%s: rx error: %d buffers missing\n", 882 dev->name, num_buf); 883 dev->stats.rx_length_errors++; 884 break; 885 } 886 page = virt_to_head_page(buf); 887 put_page(page); 888 } 889 err_buf: 890 dev->stats.rx_dropped++; 891 dev_kfree_skb(head_skb); 892 xdp_xmit: 893 return NULL; 894 } 895 896 static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq, 897 void *buf, unsigned int len, void **ctx, bool *xdp_xmit) 898 { 899 struct net_device *dev = vi->dev; 900 struct sk_buff *skb; 901 struct virtio_net_hdr_mrg_rxbuf *hdr; 902 int ret; 903 904 if (unlikely(len < vi->hdr_len + ETH_HLEN)) { 905 pr_debug("%s: short packet %i\n", dev->name, len); 906 dev->stats.rx_length_errors++; 907 if (vi->mergeable_rx_bufs) { 908 put_page(virt_to_head_page(buf)); 909 } else if (vi->big_packets) { 910 give_pages(rq, buf); 911 } else { 912 put_page(virt_to_head_page(buf)); 913 } 914 return 0; 915 } 916 917 if (vi->mergeable_rx_bufs) 918 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit); 919 else if (vi->big_packets) 920 skb = receive_big(dev, vi, rq, buf, len); 921 else 922 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit); 923 924 if (unlikely(!skb)) 925 return 0; 926 927 hdr = skb_vnet_hdr(skb); 928 929 ret = skb->len; 930 931 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) 932 skb->ip_summed = CHECKSUM_UNNECESSARY; 933 934 if (virtio_net_hdr_to_skb(skb, &hdr->hdr, 935 virtio_is_little_endian(vi->vdev))) { 936 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n", 937 dev->name, hdr->hdr.gso_type, 938 hdr->hdr.gso_size); 939 goto frame_err; 940 } 941 942 skb->protocol = eth_type_trans(skb, dev); 943 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 944 ntohs(skb->protocol), skb->len, skb->pkt_type); 945 946 napi_gro_receive(&rq->napi, skb); 947 return ret; 948 949 frame_err: 950 dev->stats.rx_frame_errors++; 951 dev_kfree_skb(skb); 952 return 0; 953 } 954 955 /* Unlike mergeable buffers, all buffers are allocated to the 956 * same size, except for the headroom. For this reason we do 957 * not need to use mergeable_len_to_ctx here - it is enough 958 * to store the headroom as the context ignoring the truesize. 959 */ 960 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, 961 gfp_t gfp) 962 { 963 struct page_frag *alloc_frag = &rq->alloc_frag; 964 char *buf; 965 unsigned int xdp_headroom = virtnet_get_headroom(vi); 966 void *ctx = (void *)(unsigned long)xdp_headroom; 967 int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom; 968 int err; 969 970 len = SKB_DATA_ALIGN(len) + 971 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 972 if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp))) 973 return -ENOMEM; 974 975 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset; 976 get_page(alloc_frag->page); 977 alloc_frag->offset += len; 978 sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom, 979 vi->hdr_len + GOOD_PACKET_LEN); 980 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); 981 if (err < 0) 982 put_page(virt_to_head_page(buf)); 983 return err; 984 } 985 986 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq, 987 gfp_t gfp) 988 { 989 struct page *first, *list = NULL; 990 char *p; 991 int i, err, offset; 992 993 sg_init_table(rq->sg, MAX_SKB_FRAGS + 2); 994 995 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ 996 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 997 first = get_a_page(rq, gfp); 998 if (!first) { 999 if (list) 1000 give_pages(rq, list); 1001 return -ENOMEM; 1002 } 1003 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE); 1004 1005 /* chain new page in list head to match sg */ 1006 first->private = (unsigned long)list; 1007 list = first; 1008 } 1009 1010 first = get_a_page(rq, gfp); 1011 if (!first) { 1012 give_pages(rq, list); 1013 return -ENOMEM; 1014 } 1015 p = page_address(first); 1016 1017 /* rq->sg[0], rq->sg[1] share the same page */ 1018 /* a separated rq->sg[0] for header - required in case !any_header_sg */ 1019 sg_set_buf(&rq->sg[0], p, vi->hdr_len); 1020 1021 /* rq->sg[1] for data packet, from offset */ 1022 offset = sizeof(struct padded_vnet_hdr); 1023 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); 1024 1025 /* chain first in list head */ 1026 first->private = (unsigned long)list; 1027 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2, 1028 first, gfp); 1029 if (err < 0) 1030 give_pages(rq, first); 1031 1032 return err; 1033 } 1034 1035 static unsigned int get_mergeable_buf_len(struct receive_queue *rq, 1036 struct ewma_pkt_len *avg_pkt_len, 1037 unsigned int room) 1038 { 1039 const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); 1040 unsigned int len; 1041 1042 if (room) 1043 return PAGE_SIZE - room; 1044 1045 len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len), 1046 rq->min_buf_len, PAGE_SIZE - hdr_len); 1047 1048 return ALIGN(len, L1_CACHE_BYTES); 1049 } 1050 1051 static int add_recvbuf_mergeable(struct virtnet_info *vi, 1052 struct receive_queue *rq, gfp_t gfp) 1053 { 1054 struct page_frag *alloc_frag = &rq->alloc_frag; 1055 unsigned int headroom = virtnet_get_headroom(vi); 1056 unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0; 1057 unsigned int room = SKB_DATA_ALIGN(headroom + tailroom); 1058 char *buf; 1059 void *ctx; 1060 int err; 1061 unsigned int len, hole; 1062 1063 /* Extra tailroom is needed to satisfy XDP's assumption. This 1064 * means rx frags coalescing won't work, but consider we've 1065 * disabled GSO for XDP, it won't be a big issue. 1066 */ 1067 len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room); 1068 if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp))) 1069 return -ENOMEM; 1070 1071 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset; 1072 buf += headroom; /* advance address leaving hole at front of pkt */ 1073 get_page(alloc_frag->page); 1074 alloc_frag->offset += len + room; 1075 hole = alloc_frag->size - alloc_frag->offset; 1076 if (hole < len + room) { 1077 /* To avoid internal fragmentation, if there is very likely not 1078 * enough space for another buffer, add the remaining space to 1079 * the current buffer. 1080 */ 1081 len += hole; 1082 alloc_frag->offset += hole; 1083 } 1084 1085 sg_init_one(rq->sg, buf, len); 1086 ctx = mergeable_len_to_ctx(len, headroom); 1087 err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); 1088 if (err < 0) 1089 put_page(virt_to_head_page(buf)); 1090 1091 return err; 1092 } 1093 1094 /* 1095 * Returns false if we couldn't fill entirely (OOM). 1096 * 1097 * Normally run in the receive path, but can also be run from ndo_open 1098 * before we're receiving packets, or from refill_work which is 1099 * careful to disable receiving (using napi_disable). 1100 */ 1101 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq, 1102 gfp_t gfp) 1103 { 1104 int err; 1105 bool oom; 1106 1107 do { 1108 if (vi->mergeable_rx_bufs) 1109 err = add_recvbuf_mergeable(vi, rq, gfp); 1110 else if (vi->big_packets) 1111 err = add_recvbuf_big(vi, rq, gfp); 1112 else 1113 err = add_recvbuf_small(vi, rq, gfp); 1114 1115 oom = err == -ENOMEM; 1116 if (err) 1117 break; 1118 } while (rq->vq->num_free); 1119 virtqueue_kick(rq->vq); 1120 return !oom; 1121 } 1122 1123 static void skb_recv_done(struct virtqueue *rvq) 1124 { 1125 struct virtnet_info *vi = rvq->vdev->priv; 1126 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)]; 1127 1128 virtqueue_napi_schedule(&rq->napi, rvq); 1129 } 1130 1131 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi) 1132 { 1133 napi_enable(napi); 1134 1135 /* If all buffers were filled by other side before we napi_enabled, we 1136 * won't get another interrupt, so process any outstanding packets now. 1137 * Call local_bh_enable after to trigger softIRQ processing. 1138 */ 1139 local_bh_disable(); 1140 virtqueue_napi_schedule(napi, vq); 1141 local_bh_enable(); 1142 } 1143 1144 static void virtnet_napi_tx_enable(struct virtnet_info *vi, 1145 struct virtqueue *vq, 1146 struct napi_struct *napi) 1147 { 1148 if (!napi->weight) 1149 return; 1150 1151 /* Tx napi touches cachelines on the cpu handling tx interrupts. Only 1152 * enable the feature if this is likely affine with the transmit path. 1153 */ 1154 if (!vi->affinity_hint_set) { 1155 napi->weight = 0; 1156 return; 1157 } 1158 1159 return virtnet_napi_enable(vq, napi); 1160 } 1161 1162 static void virtnet_napi_tx_disable(struct napi_struct *napi) 1163 { 1164 if (napi->weight) 1165 napi_disable(napi); 1166 } 1167 1168 static void refill_work(struct work_struct *work) 1169 { 1170 struct virtnet_info *vi = 1171 container_of(work, struct virtnet_info, refill.work); 1172 bool still_empty; 1173 int i; 1174 1175 for (i = 0; i < vi->curr_queue_pairs; i++) { 1176 struct receive_queue *rq = &vi->rq[i]; 1177 1178 napi_disable(&rq->napi); 1179 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL); 1180 virtnet_napi_enable(rq->vq, &rq->napi); 1181 1182 /* In theory, this can happen: if we don't get any buffers in 1183 * we will *never* try to fill again. 1184 */ 1185 if (still_empty) 1186 schedule_delayed_work(&vi->refill, HZ/2); 1187 } 1188 } 1189 1190 static int virtnet_receive(struct receive_queue *rq, int budget, bool *xdp_xmit) 1191 { 1192 struct virtnet_info *vi = rq->vq->vdev->priv; 1193 unsigned int len, received = 0, bytes = 0; 1194 void *buf; 1195 1196 if (!vi->big_packets || vi->mergeable_rx_bufs) { 1197 void *ctx; 1198 1199 while (received < budget && 1200 (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) { 1201 bytes += receive_buf(vi, rq, buf, len, ctx, xdp_xmit); 1202 received++; 1203 } 1204 } else { 1205 while (received < budget && 1206 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { 1207 bytes += receive_buf(vi, rq, buf, len, NULL, xdp_xmit); 1208 received++; 1209 } 1210 } 1211 1212 if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) { 1213 if (!try_fill_recv(vi, rq, GFP_ATOMIC)) 1214 schedule_delayed_work(&vi->refill, 0); 1215 } 1216 1217 u64_stats_update_begin(&rq->stats.syncp); 1218 rq->stats.bytes += bytes; 1219 rq->stats.packets += received; 1220 u64_stats_update_end(&rq->stats.syncp); 1221 1222 return received; 1223 } 1224 1225 static void free_old_xmit_skbs(struct send_queue *sq) 1226 { 1227 struct sk_buff *skb; 1228 unsigned int len; 1229 unsigned int packets = 0; 1230 unsigned int bytes = 0; 1231 1232 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { 1233 pr_debug("Sent skb %p\n", skb); 1234 1235 bytes += skb->len; 1236 packets++; 1237 1238 dev_consume_skb_any(skb); 1239 } 1240 1241 /* Avoid overhead when no packets have been processed 1242 * happens when called speculatively from start_xmit. 1243 */ 1244 if (!packets) 1245 return; 1246 1247 u64_stats_update_begin(&sq->stats.syncp); 1248 sq->stats.bytes += bytes; 1249 sq->stats.packets += packets; 1250 u64_stats_update_end(&sq->stats.syncp); 1251 } 1252 1253 static void virtnet_poll_cleantx(struct receive_queue *rq) 1254 { 1255 struct virtnet_info *vi = rq->vq->vdev->priv; 1256 unsigned int index = vq2rxq(rq->vq); 1257 struct send_queue *sq = &vi->sq[index]; 1258 struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index); 1259 1260 if (!sq->napi.weight) 1261 return; 1262 1263 if (__netif_tx_trylock(txq)) { 1264 free_old_xmit_skbs(sq); 1265 __netif_tx_unlock(txq); 1266 } 1267 1268 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) 1269 netif_tx_wake_queue(txq); 1270 } 1271 1272 static int virtnet_poll(struct napi_struct *napi, int budget) 1273 { 1274 struct receive_queue *rq = 1275 container_of(napi, struct receive_queue, napi); 1276 unsigned int received; 1277 bool xdp_xmit = false; 1278 1279 virtnet_poll_cleantx(rq); 1280 1281 received = virtnet_receive(rq, budget, &xdp_xmit); 1282 1283 /* Out of packets? */ 1284 if (received < budget) 1285 virtqueue_napi_complete(napi, rq->vq, received); 1286 1287 if (xdp_xmit) 1288 xdp_do_flush_map(); 1289 1290 return received; 1291 } 1292 1293 static int virtnet_open(struct net_device *dev) 1294 { 1295 struct virtnet_info *vi = netdev_priv(dev); 1296 int i, err; 1297 1298 for (i = 0; i < vi->max_queue_pairs; i++) { 1299 if (i < vi->curr_queue_pairs) 1300 /* Make sure we have some buffers: if oom use wq. */ 1301 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL)) 1302 schedule_delayed_work(&vi->refill, 0); 1303 1304 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i); 1305 if (err < 0) 1306 return err; 1307 1308 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); 1309 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi); 1310 } 1311 1312 return 0; 1313 } 1314 1315 static int virtnet_poll_tx(struct napi_struct *napi, int budget) 1316 { 1317 struct send_queue *sq = container_of(napi, struct send_queue, napi); 1318 struct virtnet_info *vi = sq->vq->vdev->priv; 1319 struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq)); 1320 1321 __netif_tx_lock(txq, raw_smp_processor_id()); 1322 free_old_xmit_skbs(sq); 1323 __netif_tx_unlock(txq); 1324 1325 virtqueue_napi_complete(napi, sq->vq, 0); 1326 1327 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) 1328 netif_tx_wake_queue(txq); 1329 1330 return 0; 1331 } 1332 1333 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) 1334 { 1335 struct virtio_net_hdr_mrg_rxbuf *hdr; 1336 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 1337 struct virtnet_info *vi = sq->vq->vdev->priv; 1338 int num_sg; 1339 unsigned hdr_len = vi->hdr_len; 1340 bool can_push; 1341 1342 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 1343 1344 can_push = vi->any_header_sg && 1345 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) && 1346 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len; 1347 /* Even if we can, don't push here yet as this would skew 1348 * csum_start offset below. */ 1349 if (can_push) 1350 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len); 1351 else 1352 hdr = skb_vnet_hdr(skb); 1353 1354 if (virtio_net_hdr_from_skb(skb, &hdr->hdr, 1355 virtio_is_little_endian(vi->vdev), false)) 1356 BUG(); 1357 1358 if (vi->mergeable_rx_bufs) 1359 hdr->num_buffers = 0; 1360 1361 sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2)); 1362 if (can_push) { 1363 __skb_push(skb, hdr_len); 1364 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len); 1365 if (unlikely(num_sg < 0)) 1366 return num_sg; 1367 /* Pull header back to avoid skew in tx bytes calculations. */ 1368 __skb_pull(skb, hdr_len); 1369 } else { 1370 sg_set_buf(sq->sg, hdr, hdr_len); 1371 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len); 1372 if (unlikely(num_sg < 0)) 1373 return num_sg; 1374 num_sg++; 1375 } 1376 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC); 1377 } 1378 1379 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 1380 { 1381 struct virtnet_info *vi = netdev_priv(dev); 1382 int qnum = skb_get_queue_mapping(skb); 1383 struct send_queue *sq = &vi->sq[qnum]; 1384 int err; 1385 struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum); 1386 bool kick = !skb->xmit_more; 1387 bool use_napi = sq->napi.weight; 1388 1389 /* Free up any pending old buffers before queueing new ones. */ 1390 free_old_xmit_skbs(sq); 1391 1392 if (use_napi && kick) 1393 virtqueue_enable_cb_delayed(sq->vq); 1394 1395 /* timestamp packet in software */ 1396 skb_tx_timestamp(skb); 1397 1398 /* Try to transmit */ 1399 err = xmit_skb(sq, skb); 1400 1401 /* This should not happen! */ 1402 if (unlikely(err)) { 1403 dev->stats.tx_fifo_errors++; 1404 if (net_ratelimit()) 1405 dev_warn(&dev->dev, 1406 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); 1407 dev->stats.tx_dropped++; 1408 dev_kfree_skb_any(skb); 1409 return NETDEV_TX_OK; 1410 } 1411 1412 /* Don't wait up for transmitted skbs to be freed. */ 1413 if (!use_napi) { 1414 skb_orphan(skb); 1415 nf_reset(skb); 1416 } 1417 1418 /* If running out of space, stop queue to avoid getting packets that we 1419 * are then unable to transmit. 1420 * An alternative would be to force queuing layer to requeue the skb by 1421 * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be 1422 * returned in a normal path of operation: it means that driver is not 1423 * maintaining the TX queue stop/start state properly, and causes 1424 * the stack to do a non-trivial amount of useless work. 1425 * Since most packets only take 1 or 2 ring slots, stopping the queue 1426 * early means 16 slots are typically wasted. 1427 */ 1428 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { 1429 netif_stop_subqueue(dev, qnum); 1430 if (!use_napi && 1431 unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { 1432 /* More just got used, free them then recheck. */ 1433 free_old_xmit_skbs(sq); 1434 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { 1435 netif_start_subqueue(dev, qnum); 1436 virtqueue_disable_cb(sq->vq); 1437 } 1438 } 1439 } 1440 1441 if (kick || netif_xmit_stopped(txq)) 1442 virtqueue_kick(sq->vq); 1443 1444 return NETDEV_TX_OK; 1445 } 1446 1447 /* 1448 * Send command via the control virtqueue and check status. Commands 1449 * supported by the hypervisor, as indicated by feature bits, should 1450 * never fail unless improperly formatted. 1451 */ 1452 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 1453 struct scatterlist *out) 1454 { 1455 struct scatterlist *sgs[4], hdr, stat; 1456 unsigned out_num = 0, tmp; 1457 1458 /* Caller should know better */ 1459 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)); 1460 1461 vi->ctrl_status = ~0; 1462 vi->ctrl_hdr.class = class; 1463 vi->ctrl_hdr.cmd = cmd; 1464 /* Add header */ 1465 sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr)); 1466 sgs[out_num++] = &hdr; 1467 1468 if (out) 1469 sgs[out_num++] = out; 1470 1471 /* Add return status. */ 1472 sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status)); 1473 sgs[out_num] = &stat; 1474 1475 BUG_ON(out_num + 1 > ARRAY_SIZE(sgs)); 1476 virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC); 1477 1478 if (unlikely(!virtqueue_kick(vi->cvq))) 1479 return vi->ctrl_status == VIRTIO_NET_OK; 1480 1481 /* Spin for a response, the kick causes an ioport write, trapping 1482 * into the hypervisor, so the request should be handled immediately. 1483 */ 1484 while (!virtqueue_get_buf(vi->cvq, &tmp) && 1485 !virtqueue_is_broken(vi->cvq)) 1486 cpu_relax(); 1487 1488 return vi->ctrl_status == VIRTIO_NET_OK; 1489 } 1490 1491 static int virtnet_set_mac_address(struct net_device *dev, void *p) 1492 { 1493 struct virtnet_info *vi = netdev_priv(dev); 1494 struct virtio_device *vdev = vi->vdev; 1495 int ret; 1496 struct sockaddr *addr; 1497 struct scatterlist sg; 1498 1499 addr = kmemdup(p, sizeof(*addr), GFP_KERNEL); 1500 if (!addr) 1501 return -ENOMEM; 1502 1503 ret = eth_prepare_mac_addr_change(dev, addr); 1504 if (ret) 1505 goto out; 1506 1507 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) { 1508 sg_init_one(&sg, addr->sa_data, dev->addr_len); 1509 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 1510 VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) { 1511 dev_warn(&vdev->dev, 1512 "Failed to set mac address by vq command.\n"); 1513 ret = -EINVAL; 1514 goto out; 1515 } 1516 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) && 1517 !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1518 unsigned int i; 1519 1520 /* Naturally, this has an atomicity problem. */ 1521 for (i = 0; i < dev->addr_len; i++) 1522 virtio_cwrite8(vdev, 1523 offsetof(struct virtio_net_config, mac) + 1524 i, addr->sa_data[i]); 1525 } 1526 1527 eth_commit_mac_addr_change(dev, p); 1528 ret = 0; 1529 1530 out: 1531 kfree(addr); 1532 return ret; 1533 } 1534 1535 static void virtnet_stats(struct net_device *dev, 1536 struct rtnl_link_stats64 *tot) 1537 { 1538 struct virtnet_info *vi = netdev_priv(dev); 1539 unsigned int start; 1540 int i; 1541 1542 for (i = 0; i < vi->max_queue_pairs; i++) { 1543 u64 tpackets, tbytes, rpackets, rbytes; 1544 struct receive_queue *rq = &vi->rq[i]; 1545 struct send_queue *sq = &vi->sq[i]; 1546 1547 do { 1548 start = u64_stats_fetch_begin_irq(&sq->stats.syncp); 1549 tpackets = sq->stats.packets; 1550 tbytes = sq->stats.bytes; 1551 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start)); 1552 1553 do { 1554 start = u64_stats_fetch_begin_irq(&rq->stats.syncp); 1555 rpackets = rq->stats.packets; 1556 rbytes = rq->stats.bytes; 1557 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start)); 1558 1559 tot->rx_packets += rpackets; 1560 tot->tx_packets += tpackets; 1561 tot->rx_bytes += rbytes; 1562 tot->tx_bytes += tbytes; 1563 } 1564 1565 tot->tx_dropped = dev->stats.tx_dropped; 1566 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 1567 tot->rx_dropped = dev->stats.rx_dropped; 1568 tot->rx_length_errors = dev->stats.rx_length_errors; 1569 tot->rx_frame_errors = dev->stats.rx_frame_errors; 1570 } 1571 1572 #ifdef CONFIG_NET_POLL_CONTROLLER 1573 static void virtnet_netpoll(struct net_device *dev) 1574 { 1575 struct virtnet_info *vi = netdev_priv(dev); 1576 int i; 1577 1578 for (i = 0; i < vi->curr_queue_pairs; i++) 1579 napi_schedule(&vi->rq[i].napi); 1580 } 1581 #endif 1582 1583 static void virtnet_ack_link_announce(struct virtnet_info *vi) 1584 { 1585 rtnl_lock(); 1586 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE, 1587 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL)) 1588 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n"); 1589 rtnl_unlock(); 1590 } 1591 1592 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) 1593 { 1594 struct scatterlist sg; 1595 struct net_device *dev = vi->dev; 1596 1597 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) 1598 return 0; 1599 1600 vi->ctrl_mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs); 1601 sg_init_one(&sg, &vi->ctrl_mq, sizeof(vi->ctrl_mq)); 1602 1603 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ, 1604 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) { 1605 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", 1606 queue_pairs); 1607 return -EINVAL; 1608 } else { 1609 vi->curr_queue_pairs = queue_pairs; 1610 /* virtnet_open() will refill when device is going to up. */ 1611 if (dev->flags & IFF_UP) 1612 schedule_delayed_work(&vi->refill, 0); 1613 } 1614 1615 return 0; 1616 } 1617 1618 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) 1619 { 1620 int err; 1621 1622 rtnl_lock(); 1623 err = _virtnet_set_queues(vi, queue_pairs); 1624 rtnl_unlock(); 1625 return err; 1626 } 1627 1628 static int virtnet_close(struct net_device *dev) 1629 { 1630 struct virtnet_info *vi = netdev_priv(dev); 1631 int i; 1632 1633 /* Make sure refill_work doesn't re-enable napi! */ 1634 cancel_delayed_work_sync(&vi->refill); 1635 1636 for (i = 0; i < vi->max_queue_pairs; i++) { 1637 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq); 1638 napi_disable(&vi->rq[i].napi); 1639 virtnet_napi_tx_disable(&vi->sq[i].napi); 1640 } 1641 1642 return 0; 1643 } 1644 1645 static void virtnet_set_rx_mode(struct net_device *dev) 1646 { 1647 struct virtnet_info *vi = netdev_priv(dev); 1648 struct scatterlist sg[2]; 1649 struct virtio_net_ctrl_mac *mac_data; 1650 struct netdev_hw_addr *ha; 1651 int uc_count; 1652 int mc_count; 1653 void *buf; 1654 int i; 1655 1656 /* We can't dynamically set ndo_set_rx_mode, so return gracefully */ 1657 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 1658 return; 1659 1660 vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0); 1661 vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 1662 1663 sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc)); 1664 1665 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 1666 VIRTIO_NET_CTRL_RX_PROMISC, sg)) 1667 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 1668 vi->ctrl_promisc ? "en" : "dis"); 1669 1670 sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti)); 1671 1672 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 1673 VIRTIO_NET_CTRL_RX_ALLMULTI, sg)) 1674 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 1675 vi->ctrl_allmulti ? "en" : "dis"); 1676 1677 uc_count = netdev_uc_count(dev); 1678 mc_count = netdev_mc_count(dev); 1679 /* MAC filter - use one buffer for both lists */ 1680 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 1681 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 1682 mac_data = buf; 1683 if (!buf) 1684 return; 1685 1686 sg_init_table(sg, 2); 1687 1688 /* Store the unicast list and count in the front of the buffer */ 1689 mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count); 1690 i = 0; 1691 netdev_for_each_uc_addr(ha, dev) 1692 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 1693 1694 sg_set_buf(&sg[0], mac_data, 1695 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 1696 1697 /* multicast list and count fill the end */ 1698 mac_data = (void *)&mac_data->macs[uc_count][0]; 1699 1700 mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count); 1701 i = 0; 1702 netdev_for_each_mc_addr(ha, dev) 1703 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 1704 1705 sg_set_buf(&sg[1], mac_data, 1706 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 1707 1708 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 1709 VIRTIO_NET_CTRL_MAC_TABLE_SET, sg)) 1710 dev_warn(&dev->dev, "Failed to set MAC filter table.\n"); 1711 1712 kfree(buf); 1713 } 1714 1715 static int virtnet_vlan_rx_add_vid(struct net_device *dev, 1716 __be16 proto, u16 vid) 1717 { 1718 struct virtnet_info *vi = netdev_priv(dev); 1719 struct scatterlist sg; 1720 1721 vi->ctrl_vid = vid; 1722 sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid)); 1723 1724 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1725 VIRTIO_NET_CTRL_VLAN_ADD, &sg)) 1726 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 1727 return 0; 1728 } 1729 1730 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, 1731 __be16 proto, u16 vid) 1732 { 1733 struct virtnet_info *vi = netdev_priv(dev); 1734 struct scatterlist sg; 1735 1736 vi->ctrl_vid = vid; 1737 sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid)); 1738 1739 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1740 VIRTIO_NET_CTRL_VLAN_DEL, &sg)) 1741 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 1742 return 0; 1743 } 1744 1745 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu) 1746 { 1747 int i; 1748 1749 if (vi->affinity_hint_set) { 1750 for (i = 0; i < vi->max_queue_pairs; i++) { 1751 virtqueue_set_affinity(vi->rq[i].vq, -1); 1752 virtqueue_set_affinity(vi->sq[i].vq, -1); 1753 } 1754 1755 vi->affinity_hint_set = false; 1756 } 1757 } 1758 1759 static void virtnet_set_affinity(struct virtnet_info *vi) 1760 { 1761 int i; 1762 int cpu; 1763 1764 /* In multiqueue mode, when the number of cpu is equal to the number of 1765 * queue pairs, we let the queue pairs to be private to one cpu by 1766 * setting the affinity hint to eliminate the contention. 1767 */ 1768 if (vi->curr_queue_pairs == 1 || 1769 vi->max_queue_pairs != num_online_cpus()) { 1770 virtnet_clean_affinity(vi, -1); 1771 return; 1772 } 1773 1774 i = 0; 1775 for_each_online_cpu(cpu) { 1776 virtqueue_set_affinity(vi->rq[i].vq, cpu); 1777 virtqueue_set_affinity(vi->sq[i].vq, cpu); 1778 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i); 1779 i++; 1780 } 1781 1782 vi->affinity_hint_set = true; 1783 } 1784 1785 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node) 1786 { 1787 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info, 1788 node); 1789 virtnet_set_affinity(vi); 1790 return 0; 1791 } 1792 1793 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node) 1794 { 1795 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info, 1796 node_dead); 1797 virtnet_set_affinity(vi); 1798 return 0; 1799 } 1800 1801 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node) 1802 { 1803 struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info, 1804 node); 1805 1806 virtnet_clean_affinity(vi, cpu); 1807 return 0; 1808 } 1809 1810 static enum cpuhp_state virtionet_online; 1811 1812 static int virtnet_cpu_notif_add(struct virtnet_info *vi) 1813 { 1814 int ret; 1815 1816 ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node); 1817 if (ret) 1818 return ret; 1819 ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD, 1820 &vi->node_dead); 1821 if (!ret) 1822 return ret; 1823 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node); 1824 return ret; 1825 } 1826 1827 static void virtnet_cpu_notif_remove(struct virtnet_info *vi) 1828 { 1829 cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node); 1830 cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD, 1831 &vi->node_dead); 1832 } 1833 1834 static void virtnet_get_ringparam(struct net_device *dev, 1835 struct ethtool_ringparam *ring) 1836 { 1837 struct virtnet_info *vi = netdev_priv(dev); 1838 1839 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq); 1840 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq); 1841 ring->rx_pending = ring->rx_max_pending; 1842 ring->tx_pending = ring->tx_max_pending; 1843 } 1844 1845 1846 static void virtnet_get_drvinfo(struct net_device *dev, 1847 struct ethtool_drvinfo *info) 1848 { 1849 struct virtnet_info *vi = netdev_priv(dev); 1850 struct virtio_device *vdev = vi->vdev; 1851 1852 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 1853 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 1854 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 1855 1856 } 1857 1858 /* TODO: Eliminate OOO packets during switching */ 1859 static int virtnet_set_channels(struct net_device *dev, 1860 struct ethtool_channels *channels) 1861 { 1862 struct virtnet_info *vi = netdev_priv(dev); 1863 u16 queue_pairs = channels->combined_count; 1864 int err; 1865 1866 /* We don't support separate rx/tx channels. 1867 * We don't allow setting 'other' channels. 1868 */ 1869 if (channels->rx_count || channels->tx_count || channels->other_count) 1870 return -EINVAL; 1871 1872 if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0) 1873 return -EINVAL; 1874 1875 /* For now we don't support modifying channels while XDP is loaded 1876 * also when XDP is loaded all RX queues have XDP programs so we only 1877 * need to check a single RX queue. 1878 */ 1879 if (vi->rq[0].xdp_prog) 1880 return -EINVAL; 1881 1882 get_online_cpus(); 1883 err = _virtnet_set_queues(vi, queue_pairs); 1884 if (!err) { 1885 netif_set_real_num_tx_queues(dev, queue_pairs); 1886 netif_set_real_num_rx_queues(dev, queue_pairs); 1887 1888 virtnet_set_affinity(vi); 1889 } 1890 put_online_cpus(); 1891 1892 return err; 1893 } 1894 1895 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data) 1896 { 1897 struct virtnet_info *vi = netdev_priv(dev); 1898 char *p = (char *)data; 1899 unsigned int i, j; 1900 1901 switch (stringset) { 1902 case ETH_SS_STATS: 1903 for (i = 0; i < vi->curr_queue_pairs; i++) { 1904 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) { 1905 snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s", 1906 i, virtnet_rq_stats_desc[j].desc); 1907 p += ETH_GSTRING_LEN; 1908 } 1909 } 1910 1911 for (i = 0; i < vi->curr_queue_pairs; i++) { 1912 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) { 1913 snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s", 1914 i, virtnet_sq_stats_desc[j].desc); 1915 p += ETH_GSTRING_LEN; 1916 } 1917 } 1918 break; 1919 } 1920 } 1921 1922 static int virtnet_get_sset_count(struct net_device *dev, int sset) 1923 { 1924 struct virtnet_info *vi = netdev_priv(dev); 1925 1926 switch (sset) { 1927 case ETH_SS_STATS: 1928 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN + 1929 VIRTNET_SQ_STATS_LEN); 1930 default: 1931 return -EOPNOTSUPP; 1932 } 1933 } 1934 1935 static void virtnet_get_ethtool_stats(struct net_device *dev, 1936 struct ethtool_stats *stats, u64 *data) 1937 { 1938 struct virtnet_info *vi = netdev_priv(dev); 1939 unsigned int idx = 0, start, i, j; 1940 const u8 *stats_base; 1941 size_t offset; 1942 1943 for (i = 0; i < vi->curr_queue_pairs; i++) { 1944 struct receive_queue *rq = &vi->rq[i]; 1945 1946 stats_base = (u8 *)&rq->stats; 1947 do { 1948 start = u64_stats_fetch_begin_irq(&rq->stats.syncp); 1949 for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) { 1950 offset = virtnet_rq_stats_desc[j].offset; 1951 data[idx + j] = *(u64 *)(stats_base + offset); 1952 } 1953 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start)); 1954 idx += VIRTNET_RQ_STATS_LEN; 1955 } 1956 1957 for (i = 0; i < vi->curr_queue_pairs; i++) { 1958 struct send_queue *sq = &vi->sq[i]; 1959 1960 stats_base = (u8 *)&sq->stats; 1961 do { 1962 start = u64_stats_fetch_begin_irq(&sq->stats.syncp); 1963 for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) { 1964 offset = virtnet_sq_stats_desc[j].offset; 1965 data[idx + j] = *(u64 *)(stats_base + offset); 1966 } 1967 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start)); 1968 idx += VIRTNET_SQ_STATS_LEN; 1969 } 1970 } 1971 1972 static void virtnet_get_channels(struct net_device *dev, 1973 struct ethtool_channels *channels) 1974 { 1975 struct virtnet_info *vi = netdev_priv(dev); 1976 1977 channels->combined_count = vi->curr_queue_pairs; 1978 channels->max_combined = vi->max_queue_pairs; 1979 channels->max_other = 0; 1980 channels->rx_count = 0; 1981 channels->tx_count = 0; 1982 channels->other_count = 0; 1983 } 1984 1985 /* Check if the user is trying to change anything besides speed/duplex */ 1986 static bool 1987 virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd) 1988 { 1989 struct ethtool_link_ksettings diff1 = *cmd; 1990 struct ethtool_link_ksettings diff2 = {}; 1991 1992 /* cmd is always set so we need to clear it, validate the port type 1993 * and also without autonegotiation we can ignore advertising 1994 */ 1995 diff1.base.speed = 0; 1996 diff2.base.port = PORT_OTHER; 1997 ethtool_link_ksettings_zero_link_mode(&diff1, advertising); 1998 diff1.base.duplex = 0; 1999 diff1.base.cmd = 0; 2000 diff1.base.link_mode_masks_nwords = 0; 2001 2002 return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) && 2003 bitmap_empty(diff1.link_modes.supported, 2004 __ETHTOOL_LINK_MODE_MASK_NBITS) && 2005 bitmap_empty(diff1.link_modes.advertising, 2006 __ETHTOOL_LINK_MODE_MASK_NBITS) && 2007 bitmap_empty(diff1.link_modes.lp_advertising, 2008 __ETHTOOL_LINK_MODE_MASK_NBITS); 2009 } 2010 2011 static int virtnet_set_link_ksettings(struct net_device *dev, 2012 const struct ethtool_link_ksettings *cmd) 2013 { 2014 struct virtnet_info *vi = netdev_priv(dev); 2015 u32 speed; 2016 2017 speed = cmd->base.speed; 2018 /* don't allow custom speed and duplex */ 2019 if (!ethtool_validate_speed(speed) || 2020 !ethtool_validate_duplex(cmd->base.duplex) || 2021 !virtnet_validate_ethtool_cmd(cmd)) 2022 return -EINVAL; 2023 vi->speed = speed; 2024 vi->duplex = cmd->base.duplex; 2025 2026 return 0; 2027 } 2028 2029 static int virtnet_get_link_ksettings(struct net_device *dev, 2030 struct ethtool_link_ksettings *cmd) 2031 { 2032 struct virtnet_info *vi = netdev_priv(dev); 2033 2034 cmd->base.speed = vi->speed; 2035 cmd->base.duplex = vi->duplex; 2036 cmd->base.port = PORT_OTHER; 2037 2038 return 0; 2039 } 2040 2041 static void virtnet_init_settings(struct net_device *dev) 2042 { 2043 struct virtnet_info *vi = netdev_priv(dev); 2044 2045 vi->speed = SPEED_UNKNOWN; 2046 vi->duplex = DUPLEX_UNKNOWN; 2047 } 2048 2049 static void virtnet_update_settings(struct virtnet_info *vi) 2050 { 2051 u32 speed; 2052 u8 duplex; 2053 2054 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) 2055 return; 2056 2057 speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config, 2058 speed)); 2059 if (ethtool_validate_speed(speed)) 2060 vi->speed = speed; 2061 duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config, 2062 duplex)); 2063 if (ethtool_validate_duplex(duplex)) 2064 vi->duplex = duplex; 2065 } 2066 2067 static const struct ethtool_ops virtnet_ethtool_ops = { 2068 .get_drvinfo = virtnet_get_drvinfo, 2069 .get_link = ethtool_op_get_link, 2070 .get_ringparam = virtnet_get_ringparam, 2071 .get_strings = virtnet_get_strings, 2072 .get_sset_count = virtnet_get_sset_count, 2073 .get_ethtool_stats = virtnet_get_ethtool_stats, 2074 .set_channels = virtnet_set_channels, 2075 .get_channels = virtnet_get_channels, 2076 .get_ts_info = ethtool_op_get_ts_info, 2077 .get_link_ksettings = virtnet_get_link_ksettings, 2078 .set_link_ksettings = virtnet_set_link_ksettings, 2079 }; 2080 2081 static void virtnet_freeze_down(struct virtio_device *vdev) 2082 { 2083 struct virtnet_info *vi = vdev->priv; 2084 int i; 2085 2086 /* Make sure no work handler is accessing the device */ 2087 flush_work(&vi->config_work); 2088 2089 netif_device_detach(vi->dev); 2090 netif_tx_disable(vi->dev); 2091 cancel_delayed_work_sync(&vi->refill); 2092 2093 if (netif_running(vi->dev)) { 2094 for (i = 0; i < vi->max_queue_pairs; i++) { 2095 napi_disable(&vi->rq[i].napi); 2096 virtnet_napi_tx_disable(&vi->sq[i].napi); 2097 } 2098 } 2099 } 2100 2101 static int init_vqs(struct virtnet_info *vi); 2102 2103 static int virtnet_restore_up(struct virtio_device *vdev) 2104 { 2105 struct virtnet_info *vi = vdev->priv; 2106 int err, i; 2107 2108 err = init_vqs(vi); 2109 if (err) 2110 return err; 2111 2112 virtio_device_ready(vdev); 2113 2114 if (netif_running(vi->dev)) { 2115 for (i = 0; i < vi->curr_queue_pairs; i++) 2116 if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL)) 2117 schedule_delayed_work(&vi->refill, 0); 2118 2119 for (i = 0; i < vi->max_queue_pairs; i++) { 2120 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); 2121 virtnet_napi_tx_enable(vi, vi->sq[i].vq, 2122 &vi->sq[i].napi); 2123 } 2124 } 2125 2126 netif_device_attach(vi->dev); 2127 return err; 2128 } 2129 2130 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads) 2131 { 2132 struct scatterlist sg; 2133 vi->ctrl_offloads = cpu_to_virtio64(vi->vdev, offloads); 2134 2135 sg_init_one(&sg, &vi->ctrl_offloads, sizeof(vi->ctrl_offloads)); 2136 2137 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS, 2138 VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) { 2139 dev_warn(&vi->dev->dev, "Fail to set guest offload. \n"); 2140 return -EINVAL; 2141 } 2142 2143 return 0; 2144 } 2145 2146 static int virtnet_clear_guest_offloads(struct virtnet_info *vi) 2147 { 2148 u64 offloads = 0; 2149 2150 if (!vi->guest_offloads) 2151 return 0; 2152 2153 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM)) 2154 offloads = 1ULL << VIRTIO_NET_F_GUEST_CSUM; 2155 2156 return virtnet_set_guest_offloads(vi, offloads); 2157 } 2158 2159 static int virtnet_restore_guest_offloads(struct virtnet_info *vi) 2160 { 2161 u64 offloads = vi->guest_offloads; 2162 2163 if (!vi->guest_offloads) 2164 return 0; 2165 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM)) 2166 offloads |= 1ULL << VIRTIO_NET_F_GUEST_CSUM; 2167 2168 return virtnet_set_guest_offloads(vi, offloads); 2169 } 2170 2171 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog, 2172 struct netlink_ext_ack *extack) 2173 { 2174 unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr); 2175 struct virtnet_info *vi = netdev_priv(dev); 2176 struct bpf_prog *old_prog; 2177 u16 xdp_qp = 0, curr_qp; 2178 int i, err; 2179 2180 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) 2181 && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) || 2182 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) || 2183 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) || 2184 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO))) { 2185 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO, disable LRO first"); 2186 return -EOPNOTSUPP; 2187 } 2188 2189 if (vi->mergeable_rx_bufs && !vi->any_header_sg) { 2190 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required"); 2191 return -EINVAL; 2192 } 2193 2194 if (dev->mtu > max_sz) { 2195 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP"); 2196 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz); 2197 return -EINVAL; 2198 } 2199 2200 curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs; 2201 if (prog) 2202 xdp_qp = nr_cpu_ids; 2203 2204 /* XDP requires extra queues for XDP_TX */ 2205 if (curr_qp + xdp_qp > vi->max_queue_pairs) { 2206 NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available"); 2207 netdev_warn(dev, "request %i queues but max is %i\n", 2208 curr_qp + xdp_qp, vi->max_queue_pairs); 2209 return -ENOMEM; 2210 } 2211 2212 if (prog) { 2213 prog = bpf_prog_add(prog, vi->max_queue_pairs - 1); 2214 if (IS_ERR(prog)) 2215 return PTR_ERR(prog); 2216 } 2217 2218 /* Make sure NAPI is not using any XDP TX queues for RX. */ 2219 if (netif_running(dev)) 2220 for (i = 0; i < vi->max_queue_pairs; i++) 2221 napi_disable(&vi->rq[i].napi); 2222 2223 netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp); 2224 err = _virtnet_set_queues(vi, curr_qp + xdp_qp); 2225 if (err) 2226 goto err; 2227 vi->xdp_queue_pairs = xdp_qp; 2228 2229 for (i = 0; i < vi->max_queue_pairs; i++) { 2230 old_prog = rtnl_dereference(vi->rq[i].xdp_prog); 2231 rcu_assign_pointer(vi->rq[i].xdp_prog, prog); 2232 if (i == 0) { 2233 if (!old_prog) 2234 virtnet_clear_guest_offloads(vi); 2235 if (!prog) 2236 virtnet_restore_guest_offloads(vi); 2237 } 2238 if (old_prog) 2239 bpf_prog_put(old_prog); 2240 if (netif_running(dev)) 2241 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); 2242 } 2243 2244 return 0; 2245 2246 err: 2247 for (i = 0; i < vi->max_queue_pairs; i++) 2248 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); 2249 if (prog) 2250 bpf_prog_sub(prog, vi->max_queue_pairs - 1); 2251 return err; 2252 } 2253 2254 static u32 virtnet_xdp_query(struct net_device *dev) 2255 { 2256 struct virtnet_info *vi = netdev_priv(dev); 2257 const struct bpf_prog *xdp_prog; 2258 int i; 2259 2260 for (i = 0; i < vi->max_queue_pairs; i++) { 2261 xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog); 2262 if (xdp_prog) 2263 return xdp_prog->aux->id; 2264 } 2265 return 0; 2266 } 2267 2268 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp) 2269 { 2270 switch (xdp->command) { 2271 case XDP_SETUP_PROG: 2272 return virtnet_xdp_set(dev, xdp->prog, xdp->extack); 2273 case XDP_QUERY_PROG: 2274 xdp->prog_id = virtnet_xdp_query(dev); 2275 xdp->prog_attached = !!xdp->prog_id; 2276 return 0; 2277 default: 2278 return -EINVAL; 2279 } 2280 } 2281 2282 static const struct net_device_ops virtnet_netdev = { 2283 .ndo_open = virtnet_open, 2284 .ndo_stop = virtnet_close, 2285 .ndo_start_xmit = start_xmit, 2286 .ndo_validate_addr = eth_validate_addr, 2287 .ndo_set_mac_address = virtnet_set_mac_address, 2288 .ndo_set_rx_mode = virtnet_set_rx_mode, 2289 .ndo_get_stats64 = virtnet_stats, 2290 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 2291 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 2292 #ifdef CONFIG_NET_POLL_CONTROLLER 2293 .ndo_poll_controller = virtnet_netpoll, 2294 #endif 2295 .ndo_bpf = virtnet_xdp, 2296 .ndo_xdp_xmit = virtnet_xdp_xmit, 2297 .ndo_xdp_flush = virtnet_xdp_flush, 2298 .ndo_features_check = passthru_features_check, 2299 }; 2300 2301 static void virtnet_config_changed_work(struct work_struct *work) 2302 { 2303 struct virtnet_info *vi = 2304 container_of(work, struct virtnet_info, config_work); 2305 u16 v; 2306 2307 if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS, 2308 struct virtio_net_config, status, &v) < 0) 2309 return; 2310 2311 if (v & VIRTIO_NET_S_ANNOUNCE) { 2312 netdev_notify_peers(vi->dev); 2313 virtnet_ack_link_announce(vi); 2314 } 2315 2316 /* Ignore unknown (future) status bits */ 2317 v &= VIRTIO_NET_S_LINK_UP; 2318 2319 if (vi->status == v) 2320 return; 2321 2322 vi->status = v; 2323 2324 if (vi->status & VIRTIO_NET_S_LINK_UP) { 2325 virtnet_update_settings(vi); 2326 netif_carrier_on(vi->dev); 2327 netif_tx_wake_all_queues(vi->dev); 2328 } else { 2329 netif_carrier_off(vi->dev); 2330 netif_tx_stop_all_queues(vi->dev); 2331 } 2332 } 2333 2334 static void virtnet_config_changed(struct virtio_device *vdev) 2335 { 2336 struct virtnet_info *vi = vdev->priv; 2337 2338 schedule_work(&vi->config_work); 2339 } 2340 2341 static void virtnet_free_queues(struct virtnet_info *vi) 2342 { 2343 int i; 2344 2345 for (i = 0; i < vi->max_queue_pairs; i++) { 2346 napi_hash_del(&vi->rq[i].napi); 2347 netif_napi_del(&vi->rq[i].napi); 2348 netif_napi_del(&vi->sq[i].napi); 2349 } 2350 2351 /* We called napi_hash_del() before netif_napi_del(), 2352 * we need to respect an RCU grace period before freeing vi->rq 2353 */ 2354 synchronize_net(); 2355 2356 kfree(vi->rq); 2357 kfree(vi->sq); 2358 } 2359 2360 static void _free_receive_bufs(struct virtnet_info *vi) 2361 { 2362 struct bpf_prog *old_prog; 2363 int i; 2364 2365 for (i = 0; i < vi->max_queue_pairs; i++) { 2366 while (vi->rq[i].pages) 2367 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0); 2368 2369 old_prog = rtnl_dereference(vi->rq[i].xdp_prog); 2370 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL); 2371 if (old_prog) 2372 bpf_prog_put(old_prog); 2373 } 2374 } 2375 2376 static void free_receive_bufs(struct virtnet_info *vi) 2377 { 2378 rtnl_lock(); 2379 _free_receive_bufs(vi); 2380 rtnl_unlock(); 2381 } 2382 2383 static void free_receive_page_frags(struct virtnet_info *vi) 2384 { 2385 int i; 2386 for (i = 0; i < vi->max_queue_pairs; i++) 2387 if (vi->rq[i].alloc_frag.page) 2388 put_page(vi->rq[i].alloc_frag.page); 2389 } 2390 2391 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q) 2392 { 2393 if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs)) 2394 return false; 2395 else if (q < vi->curr_queue_pairs) 2396 return true; 2397 else 2398 return false; 2399 } 2400 2401 static void free_unused_bufs(struct virtnet_info *vi) 2402 { 2403 void *buf; 2404 int i; 2405 2406 for (i = 0; i < vi->max_queue_pairs; i++) { 2407 struct virtqueue *vq = vi->sq[i].vq; 2408 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { 2409 if (!is_xdp_raw_buffer_queue(vi, i)) 2410 dev_kfree_skb(buf); 2411 else 2412 put_page(virt_to_head_page(buf)); 2413 } 2414 } 2415 2416 for (i = 0; i < vi->max_queue_pairs; i++) { 2417 struct virtqueue *vq = vi->rq[i].vq; 2418 2419 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { 2420 if (vi->mergeable_rx_bufs) { 2421 put_page(virt_to_head_page(buf)); 2422 } else if (vi->big_packets) { 2423 give_pages(&vi->rq[i], buf); 2424 } else { 2425 put_page(virt_to_head_page(buf)); 2426 } 2427 } 2428 } 2429 } 2430 2431 static void virtnet_del_vqs(struct virtnet_info *vi) 2432 { 2433 struct virtio_device *vdev = vi->vdev; 2434 2435 virtnet_clean_affinity(vi, -1); 2436 2437 vdev->config->del_vqs(vdev); 2438 2439 virtnet_free_queues(vi); 2440 } 2441 2442 /* How large should a single buffer be so a queue full of these can fit at 2443 * least one full packet? 2444 * Logic below assumes the mergeable buffer header is used. 2445 */ 2446 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq) 2447 { 2448 const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); 2449 unsigned int rq_size = virtqueue_get_vring_size(vq); 2450 unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu; 2451 unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len; 2452 unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size); 2453 2454 return max(max(min_buf_len, hdr_len) - hdr_len, 2455 (unsigned int)GOOD_PACKET_LEN); 2456 } 2457 2458 static int virtnet_find_vqs(struct virtnet_info *vi) 2459 { 2460 vq_callback_t **callbacks; 2461 struct virtqueue **vqs; 2462 int ret = -ENOMEM; 2463 int i, total_vqs; 2464 const char **names; 2465 bool *ctx; 2466 2467 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by 2468 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by 2469 * possible control vq. 2470 */ 2471 total_vqs = vi->max_queue_pairs * 2 + 2472 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); 2473 2474 /* Allocate space for find_vqs parameters */ 2475 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); 2476 if (!vqs) 2477 goto err_vq; 2478 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); 2479 if (!callbacks) 2480 goto err_callback; 2481 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); 2482 if (!names) 2483 goto err_names; 2484 if (!vi->big_packets || vi->mergeable_rx_bufs) { 2485 ctx = kzalloc(total_vqs * sizeof(*ctx), GFP_KERNEL); 2486 if (!ctx) 2487 goto err_ctx; 2488 } else { 2489 ctx = NULL; 2490 } 2491 2492 /* Parameters for control virtqueue, if any */ 2493 if (vi->has_cvq) { 2494 callbacks[total_vqs - 1] = NULL; 2495 names[total_vqs - 1] = "control"; 2496 } 2497 2498 /* Allocate/initialize parameters for send/receive virtqueues */ 2499 for (i = 0; i < vi->max_queue_pairs; i++) { 2500 callbacks[rxq2vq(i)] = skb_recv_done; 2501 callbacks[txq2vq(i)] = skb_xmit_done; 2502 sprintf(vi->rq[i].name, "input.%d", i); 2503 sprintf(vi->sq[i].name, "output.%d", i); 2504 names[rxq2vq(i)] = vi->rq[i].name; 2505 names[txq2vq(i)] = vi->sq[i].name; 2506 if (ctx) 2507 ctx[rxq2vq(i)] = true; 2508 } 2509 2510 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, 2511 names, ctx, NULL); 2512 if (ret) 2513 goto err_find; 2514 2515 if (vi->has_cvq) { 2516 vi->cvq = vqs[total_vqs - 1]; 2517 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 2518 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER; 2519 } 2520 2521 for (i = 0; i < vi->max_queue_pairs; i++) { 2522 vi->rq[i].vq = vqs[rxq2vq(i)]; 2523 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq); 2524 vi->sq[i].vq = vqs[txq2vq(i)]; 2525 } 2526 2527 kfree(names); 2528 kfree(callbacks); 2529 kfree(vqs); 2530 kfree(ctx); 2531 2532 return 0; 2533 2534 err_find: 2535 kfree(ctx); 2536 err_ctx: 2537 kfree(names); 2538 err_names: 2539 kfree(callbacks); 2540 err_callback: 2541 kfree(vqs); 2542 err_vq: 2543 return ret; 2544 } 2545 2546 static int virtnet_alloc_queues(struct virtnet_info *vi) 2547 { 2548 int i; 2549 2550 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL); 2551 if (!vi->sq) 2552 goto err_sq; 2553 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL); 2554 if (!vi->rq) 2555 goto err_rq; 2556 2557 INIT_DELAYED_WORK(&vi->refill, refill_work); 2558 for (i = 0; i < vi->max_queue_pairs; i++) { 2559 vi->rq[i].pages = NULL; 2560 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll, 2561 napi_weight); 2562 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx, 2563 napi_tx ? napi_weight : 0); 2564 2565 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); 2566 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len); 2567 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); 2568 2569 u64_stats_init(&vi->rq[i].stats.syncp); 2570 u64_stats_init(&vi->sq[i].stats.syncp); 2571 } 2572 2573 return 0; 2574 2575 err_rq: 2576 kfree(vi->sq); 2577 err_sq: 2578 return -ENOMEM; 2579 } 2580 2581 static int init_vqs(struct virtnet_info *vi) 2582 { 2583 int ret; 2584 2585 /* Allocate send & receive queues */ 2586 ret = virtnet_alloc_queues(vi); 2587 if (ret) 2588 goto err; 2589 2590 ret = virtnet_find_vqs(vi); 2591 if (ret) 2592 goto err_free; 2593 2594 get_online_cpus(); 2595 virtnet_set_affinity(vi); 2596 put_online_cpus(); 2597 2598 return 0; 2599 2600 err_free: 2601 virtnet_free_queues(vi); 2602 err: 2603 return ret; 2604 } 2605 2606 #ifdef CONFIG_SYSFS 2607 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue, 2608 char *buf) 2609 { 2610 struct virtnet_info *vi = netdev_priv(queue->dev); 2611 unsigned int queue_index = get_netdev_rx_queue_index(queue); 2612 unsigned int headroom = virtnet_get_headroom(vi); 2613 unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0; 2614 struct ewma_pkt_len *avg; 2615 2616 BUG_ON(queue_index >= vi->max_queue_pairs); 2617 avg = &vi->rq[queue_index].mrg_avg_pkt_len; 2618 return sprintf(buf, "%u\n", 2619 get_mergeable_buf_len(&vi->rq[queue_index], avg, 2620 SKB_DATA_ALIGN(headroom + tailroom))); 2621 } 2622 2623 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute = 2624 __ATTR_RO(mergeable_rx_buffer_size); 2625 2626 static struct attribute *virtio_net_mrg_rx_attrs[] = { 2627 &mergeable_rx_buffer_size_attribute.attr, 2628 NULL 2629 }; 2630 2631 static const struct attribute_group virtio_net_mrg_rx_group = { 2632 .name = "virtio_net", 2633 .attrs = virtio_net_mrg_rx_attrs 2634 }; 2635 #endif 2636 2637 static bool virtnet_fail_on_feature(struct virtio_device *vdev, 2638 unsigned int fbit, 2639 const char *fname, const char *dname) 2640 { 2641 if (!virtio_has_feature(vdev, fbit)) 2642 return false; 2643 2644 dev_err(&vdev->dev, "device advertises feature %s but not %s", 2645 fname, dname); 2646 2647 return true; 2648 } 2649 2650 #define VIRTNET_FAIL_ON(vdev, fbit, dbit) \ 2651 virtnet_fail_on_feature(vdev, fbit, #fbit, dbit) 2652 2653 static bool virtnet_validate_features(struct virtio_device *vdev) 2654 { 2655 if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) && 2656 (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX, 2657 "VIRTIO_NET_F_CTRL_VQ") || 2658 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN, 2659 "VIRTIO_NET_F_CTRL_VQ") || 2660 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE, 2661 "VIRTIO_NET_F_CTRL_VQ") || 2662 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") || 2663 VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR, 2664 "VIRTIO_NET_F_CTRL_VQ"))) { 2665 return false; 2666 } 2667 2668 return true; 2669 } 2670 2671 #define MIN_MTU ETH_MIN_MTU 2672 #define MAX_MTU ETH_MAX_MTU 2673 2674 static int virtnet_validate(struct virtio_device *vdev) 2675 { 2676 if (!vdev->config->get) { 2677 dev_err(&vdev->dev, "%s failure: config access disabled\n", 2678 __func__); 2679 return -EINVAL; 2680 } 2681 2682 if (!virtnet_validate_features(vdev)) 2683 return -EINVAL; 2684 2685 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { 2686 int mtu = virtio_cread16(vdev, 2687 offsetof(struct virtio_net_config, 2688 mtu)); 2689 if (mtu < MIN_MTU) 2690 __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU); 2691 } 2692 2693 return 0; 2694 } 2695 2696 static int virtnet_probe(struct virtio_device *vdev) 2697 { 2698 int i, err = -ENOMEM; 2699 struct net_device *dev; 2700 struct virtnet_info *vi; 2701 u16 max_queue_pairs; 2702 int mtu; 2703 2704 /* Find if host supports multiqueue virtio_net device */ 2705 err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ, 2706 struct virtio_net_config, 2707 max_virtqueue_pairs, &max_queue_pairs); 2708 2709 /* We need at least 2 queue's */ 2710 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN || 2711 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX || 2712 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 2713 max_queue_pairs = 1; 2714 2715 /* Allocate ourselves a network device with room for our info */ 2716 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); 2717 if (!dev) 2718 return -ENOMEM; 2719 2720 /* Set up network device as normal. */ 2721 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE; 2722 dev->netdev_ops = &virtnet_netdev; 2723 dev->features = NETIF_F_HIGHDMA; 2724 2725 dev->ethtool_ops = &virtnet_ethtool_ops; 2726 SET_NETDEV_DEV(dev, &vdev->dev); 2727 2728 /* Do we support "hardware" checksums? */ 2729 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 2730 /* This opens up the world of extra features. */ 2731 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG; 2732 if (csum) 2733 dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG; 2734 2735 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 2736 dev->hw_features |= NETIF_F_TSO 2737 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 2738 } 2739 /* Individual feature bits: what can host handle? */ 2740 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 2741 dev->hw_features |= NETIF_F_TSO; 2742 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 2743 dev->hw_features |= NETIF_F_TSO6; 2744 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 2745 dev->hw_features |= NETIF_F_TSO_ECN; 2746 2747 dev->features |= NETIF_F_GSO_ROBUST; 2748 2749 if (gso) 2750 dev->features |= dev->hw_features & NETIF_F_ALL_TSO; 2751 /* (!csum && gso) case will be fixed by register_netdev() */ 2752 } 2753 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM)) 2754 dev->features |= NETIF_F_RXCSUM; 2755 2756 dev->vlan_features = dev->features; 2757 2758 /* MTU range: 68 - 65535 */ 2759 dev->min_mtu = MIN_MTU; 2760 dev->max_mtu = MAX_MTU; 2761 2762 /* Configuration may specify what MAC to use. Otherwise random. */ 2763 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 2764 virtio_cread_bytes(vdev, 2765 offsetof(struct virtio_net_config, mac), 2766 dev->dev_addr, dev->addr_len); 2767 else 2768 eth_hw_addr_random(dev); 2769 2770 /* Set up our device-specific information */ 2771 vi = netdev_priv(dev); 2772 vi->dev = dev; 2773 vi->vdev = vdev; 2774 vdev->priv = vi; 2775 2776 INIT_WORK(&vi->config_work, virtnet_config_changed_work); 2777 2778 /* If we can receive ANY GSO packets, we must allocate large ones. */ 2779 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 2780 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 2781 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) || 2782 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO)) 2783 vi->big_packets = true; 2784 2785 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 2786 vi->mergeable_rx_bufs = true; 2787 2788 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) || 2789 virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) 2790 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); 2791 else 2792 vi->hdr_len = sizeof(struct virtio_net_hdr); 2793 2794 if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) || 2795 virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) 2796 vi->any_header_sg = true; 2797 2798 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 2799 vi->has_cvq = true; 2800 2801 if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { 2802 mtu = virtio_cread16(vdev, 2803 offsetof(struct virtio_net_config, 2804 mtu)); 2805 if (mtu < dev->min_mtu) { 2806 /* Should never trigger: MTU was previously validated 2807 * in virtnet_validate. 2808 */ 2809 dev_err(&vdev->dev, "device MTU appears to have changed " 2810 "it is now %d < %d", mtu, dev->min_mtu); 2811 goto free; 2812 } 2813 2814 dev->mtu = mtu; 2815 dev->max_mtu = mtu; 2816 2817 /* TODO: size buffers correctly in this case. */ 2818 if (dev->mtu > ETH_DATA_LEN) 2819 vi->big_packets = true; 2820 } 2821 2822 if (vi->any_header_sg) 2823 dev->needed_headroom = vi->hdr_len; 2824 2825 /* Enable multiqueue by default */ 2826 if (num_online_cpus() >= max_queue_pairs) 2827 vi->curr_queue_pairs = max_queue_pairs; 2828 else 2829 vi->curr_queue_pairs = num_online_cpus(); 2830 vi->max_queue_pairs = max_queue_pairs; 2831 2832 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ 2833 err = init_vqs(vi); 2834 if (err) 2835 goto free; 2836 2837 #ifdef CONFIG_SYSFS 2838 if (vi->mergeable_rx_bufs) 2839 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group; 2840 #endif 2841 netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs); 2842 netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); 2843 2844 virtnet_init_settings(dev); 2845 2846 err = register_netdev(dev); 2847 if (err) { 2848 pr_debug("virtio_net: registering device failed\n"); 2849 goto free_vqs; 2850 } 2851 2852 virtio_device_ready(vdev); 2853 2854 err = virtnet_cpu_notif_add(vi); 2855 if (err) { 2856 pr_debug("virtio_net: registering cpu notifier failed\n"); 2857 goto free_unregister_netdev; 2858 } 2859 2860 virtnet_set_queues(vi, vi->curr_queue_pairs); 2861 2862 /* Assume link up if device can't report link status, 2863 otherwise get link status from config. */ 2864 netif_carrier_off(dev); 2865 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 2866 schedule_work(&vi->config_work); 2867 } else { 2868 vi->status = VIRTIO_NET_S_LINK_UP; 2869 virtnet_update_settings(vi); 2870 netif_carrier_on(dev); 2871 } 2872 2873 for (i = 0; i < ARRAY_SIZE(guest_offloads); i++) 2874 if (virtio_has_feature(vi->vdev, guest_offloads[i])) 2875 set_bit(guest_offloads[i], &vi->guest_offloads); 2876 2877 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", 2878 dev->name, max_queue_pairs); 2879 2880 return 0; 2881 2882 free_unregister_netdev: 2883 vi->vdev->config->reset(vdev); 2884 2885 unregister_netdev(dev); 2886 free_vqs: 2887 cancel_delayed_work_sync(&vi->refill); 2888 free_receive_page_frags(vi); 2889 virtnet_del_vqs(vi); 2890 free: 2891 free_netdev(dev); 2892 return err; 2893 } 2894 2895 static void remove_vq_common(struct virtnet_info *vi) 2896 { 2897 vi->vdev->config->reset(vi->vdev); 2898 2899 /* Free unused buffers in both send and recv, if any. */ 2900 free_unused_bufs(vi); 2901 2902 free_receive_bufs(vi); 2903 2904 free_receive_page_frags(vi); 2905 2906 virtnet_del_vqs(vi); 2907 } 2908 2909 static void virtnet_remove(struct virtio_device *vdev) 2910 { 2911 struct virtnet_info *vi = vdev->priv; 2912 2913 virtnet_cpu_notif_remove(vi); 2914 2915 /* Make sure no work handler is accessing the device. */ 2916 flush_work(&vi->config_work); 2917 2918 unregister_netdev(vi->dev); 2919 2920 remove_vq_common(vi); 2921 2922 free_netdev(vi->dev); 2923 } 2924 2925 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev) 2926 { 2927 struct virtnet_info *vi = vdev->priv; 2928 2929 virtnet_cpu_notif_remove(vi); 2930 virtnet_freeze_down(vdev); 2931 remove_vq_common(vi); 2932 2933 return 0; 2934 } 2935 2936 static __maybe_unused int virtnet_restore(struct virtio_device *vdev) 2937 { 2938 struct virtnet_info *vi = vdev->priv; 2939 int err; 2940 2941 err = virtnet_restore_up(vdev); 2942 if (err) 2943 return err; 2944 virtnet_set_queues(vi, vi->curr_queue_pairs); 2945 2946 err = virtnet_cpu_notif_add(vi); 2947 if (err) 2948 return err; 2949 2950 return 0; 2951 } 2952 2953 static struct virtio_device_id id_table[] = { 2954 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 2955 { 0 }, 2956 }; 2957 2958 #define VIRTNET_FEATURES \ 2959 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \ 2960 VIRTIO_NET_F_MAC, \ 2961 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \ 2962 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \ 2963 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \ 2964 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \ 2965 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \ 2966 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \ 2967 VIRTIO_NET_F_CTRL_MAC_ADDR, \ 2968 VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \ 2969 VIRTIO_NET_F_SPEED_DUPLEX 2970 2971 static unsigned int features[] = { 2972 VIRTNET_FEATURES, 2973 }; 2974 2975 static unsigned int features_legacy[] = { 2976 VIRTNET_FEATURES, 2977 VIRTIO_NET_F_GSO, 2978 VIRTIO_F_ANY_LAYOUT, 2979 }; 2980 2981 static struct virtio_driver virtio_net_driver = { 2982 .feature_table = features, 2983 .feature_table_size = ARRAY_SIZE(features), 2984 .feature_table_legacy = features_legacy, 2985 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 2986 .driver.name = KBUILD_MODNAME, 2987 .driver.owner = THIS_MODULE, 2988 .id_table = id_table, 2989 .validate = virtnet_validate, 2990 .probe = virtnet_probe, 2991 .remove = virtnet_remove, 2992 .config_changed = virtnet_config_changed, 2993 #ifdef CONFIG_PM_SLEEP 2994 .freeze = virtnet_freeze, 2995 .restore = virtnet_restore, 2996 #endif 2997 }; 2998 2999 static __init int virtio_net_driver_init(void) 3000 { 3001 int ret; 3002 3003 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online", 3004 virtnet_cpu_online, 3005 virtnet_cpu_down_prep); 3006 if (ret < 0) 3007 goto out; 3008 virtionet_online = ret; 3009 ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead", 3010 NULL, virtnet_cpu_dead); 3011 if (ret) 3012 goto err_dead; 3013 3014 ret = register_virtio_driver(&virtio_net_driver); 3015 if (ret) 3016 goto err_virtio; 3017 return 0; 3018 err_virtio: 3019 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD); 3020 err_dead: 3021 cpuhp_remove_multi_state(virtionet_online); 3022 out: 3023 return ret; 3024 } 3025 module_init(virtio_net_driver_init); 3026 3027 static __exit void virtio_net_driver_exit(void) 3028 { 3029 unregister_virtio_driver(&virtio_net_driver); 3030 cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD); 3031 cpuhp_remove_multi_state(virtionet_online); 3032 } 3033 module_exit(virtio_net_driver_exit); 3034 3035 MODULE_DEVICE_TABLE(virtio, id_table); 3036 MODULE_DESCRIPTION("Virtio network driver"); 3037 MODULE_LICENSE("GPL"); 3038