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