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