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