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, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 //#define DEBUG 20 #include <linux/netdevice.h> 21 #include <linux/etherdevice.h> 22 #include <linux/ethtool.h> 23 #include <linux/module.h> 24 #include <linux/virtio.h> 25 #include <linux/virtio_net.h> 26 #include <linux/scatterlist.h> 27 #include <linux/if_vlan.h> 28 #include <linux/slab.h> 29 #include <linux/cpu.h> 30 31 static int napi_weight = NAPI_POLL_WEIGHT; 32 module_param(napi_weight, int, 0444); 33 34 static bool csum = true, gso = true; 35 module_param(csum, bool, 0444); 36 module_param(gso, bool, 0444); 37 38 /* FIXME: MTU in config. */ 39 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 40 #define MERGE_BUFFER_LEN (ALIGN(GOOD_PACKET_LEN + \ 41 sizeof(struct virtio_net_hdr_mrg_rxbuf), \ 42 L1_CACHE_BYTES)) 43 #define GOOD_COPY_LEN 128 44 45 #define VIRTNET_DRIVER_VERSION "1.0.0" 46 47 struct virtnet_stats { 48 struct u64_stats_sync tx_syncp; 49 struct u64_stats_sync rx_syncp; 50 u64 tx_bytes; 51 u64 tx_packets; 52 53 u64 rx_bytes; 54 u64 rx_packets; 55 }; 56 57 /* Internal representation of a send virtqueue */ 58 struct send_queue { 59 /* Virtqueue associated with this send _queue */ 60 struct virtqueue *vq; 61 62 /* TX: fragments + linear part + virtio header */ 63 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 64 65 /* Name of the send queue: output.$index */ 66 char name[40]; 67 }; 68 69 /* Internal representation of a receive virtqueue */ 70 struct receive_queue { 71 /* Virtqueue associated with this receive_queue */ 72 struct virtqueue *vq; 73 74 struct napi_struct napi; 75 76 /* Number of input buffers, and max we've ever had. */ 77 unsigned int num, max; 78 79 /* Chain pages by the private ptr. */ 80 struct page *pages; 81 82 /* RX: fragments + linear part + virtio header */ 83 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 84 85 /* Name of this receive queue: input.$index */ 86 char name[40]; 87 }; 88 89 struct virtnet_info { 90 struct virtio_device *vdev; 91 struct virtqueue *cvq; 92 struct net_device *dev; 93 struct send_queue *sq; 94 struct receive_queue *rq; 95 unsigned int status; 96 97 /* Max # of queue pairs supported by the device */ 98 u16 max_queue_pairs; 99 100 /* # of queue pairs currently used by the driver */ 101 u16 curr_queue_pairs; 102 103 /* I like... big packets and I cannot lie! */ 104 bool big_packets; 105 106 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 107 bool mergeable_rx_bufs; 108 109 /* Has control virtqueue */ 110 bool has_cvq; 111 112 /* Host can handle any s/g split between our header and packet data */ 113 bool any_header_sg; 114 115 /* enable config space updates */ 116 bool config_enable; 117 118 /* Active statistics */ 119 struct virtnet_stats __percpu *stats; 120 121 /* Work struct for refilling if we run low on memory. */ 122 struct delayed_work refill; 123 124 /* Work struct for config space updates */ 125 struct work_struct config_work; 126 127 /* Lock for config space updates */ 128 struct mutex config_lock; 129 130 /* Page_frag for GFP_KERNEL packet buffer allocation when we run 131 * low on memory. 132 */ 133 struct page_frag alloc_frag; 134 135 /* Does the affinity hint is set for virtqueues? */ 136 bool affinity_hint_set; 137 138 /* CPU hot plug notifier */ 139 struct notifier_block nb; 140 }; 141 142 struct skb_vnet_hdr { 143 union { 144 struct virtio_net_hdr hdr; 145 struct virtio_net_hdr_mrg_rxbuf mhdr; 146 }; 147 }; 148 149 struct padded_vnet_hdr { 150 struct virtio_net_hdr hdr; 151 /* 152 * virtio_net_hdr should be in a separated sg buffer because of a 153 * QEMU bug, and data sg buffer shares same page with this header sg. 154 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 155 */ 156 char padding[6]; 157 }; 158 159 /* Converting between virtqueue no. and kernel tx/rx queue no. 160 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq 161 */ 162 static int vq2txq(struct virtqueue *vq) 163 { 164 return (vq->index - 1) / 2; 165 } 166 167 static int txq2vq(int txq) 168 { 169 return txq * 2 + 1; 170 } 171 172 static int vq2rxq(struct virtqueue *vq) 173 { 174 return vq->index / 2; 175 } 176 177 static int rxq2vq(int rxq) 178 { 179 return rxq * 2; 180 } 181 182 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 183 { 184 return (struct skb_vnet_hdr *)skb->cb; 185 } 186 187 /* 188 * private is used to chain pages for big packets, put the whole 189 * most recent used list in the beginning for reuse 190 */ 191 static void give_pages(struct receive_queue *rq, struct page *page) 192 { 193 struct page *end; 194 195 /* Find end of list, sew whole thing into vi->rq.pages. */ 196 for (end = page; end->private; end = (struct page *)end->private); 197 end->private = (unsigned long)rq->pages; 198 rq->pages = page; 199 } 200 201 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) 202 { 203 struct page *p = rq->pages; 204 205 if (p) { 206 rq->pages = (struct page *)p->private; 207 /* clear private here, it is used to chain pages */ 208 p->private = 0; 209 } else 210 p = alloc_page(gfp_mask); 211 return p; 212 } 213 214 static void skb_xmit_done(struct virtqueue *vq) 215 { 216 struct virtnet_info *vi = vq->vdev->priv; 217 218 /* Suppress further interrupts. */ 219 virtqueue_disable_cb(vq); 220 221 /* We were probably waiting for more output buffers. */ 222 netif_wake_subqueue(vi->dev, vq2txq(vq)); 223 } 224 225 /* Called from bottom half context */ 226 static struct sk_buff *page_to_skb(struct receive_queue *rq, 227 struct page *page, unsigned int offset, 228 unsigned int len, unsigned int truesize) 229 { 230 struct virtnet_info *vi = rq->vq->vdev->priv; 231 struct sk_buff *skb; 232 struct skb_vnet_hdr *hdr; 233 unsigned int copy, hdr_len, hdr_padded_len; 234 char *p; 235 236 p = page_address(page) + offset; 237 238 /* copy small packet so we can reuse these pages for small data */ 239 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 240 if (unlikely(!skb)) 241 return NULL; 242 243 hdr = skb_vnet_hdr(skb); 244 245 if (vi->mergeable_rx_bufs) { 246 hdr_len = sizeof hdr->mhdr; 247 hdr_padded_len = sizeof hdr->mhdr; 248 } else { 249 hdr_len = sizeof hdr->hdr; 250 hdr_padded_len = sizeof(struct padded_vnet_hdr); 251 } 252 253 memcpy(hdr, p, hdr_len); 254 255 len -= hdr_len; 256 offset += hdr_padded_len; 257 p += hdr_padded_len; 258 259 copy = len; 260 if (copy > skb_tailroom(skb)) 261 copy = skb_tailroom(skb); 262 memcpy(skb_put(skb, copy), p, copy); 263 264 len -= copy; 265 offset += copy; 266 267 if (vi->mergeable_rx_bufs) { 268 if (len) 269 skb_add_rx_frag(skb, 0, page, offset, len, truesize); 270 else 271 put_page(page); 272 return skb; 273 } 274 275 /* 276 * Verify that we can indeed put this data into a skb. 277 * This is here to handle cases when the device erroneously 278 * tries to receive more than is possible. This is usually 279 * the case of a broken device. 280 */ 281 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 282 net_dbg_ratelimited("%s: too much data\n", skb->dev->name); 283 dev_kfree_skb(skb); 284 return NULL; 285 } 286 BUG_ON(offset >= PAGE_SIZE); 287 while (len) { 288 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len); 289 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset, 290 frag_size, truesize); 291 len -= frag_size; 292 page = (struct page *)page->private; 293 offset = 0; 294 } 295 296 if (page) 297 give_pages(rq, page); 298 299 return skb; 300 } 301 302 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *head_skb) 303 { 304 struct skb_vnet_hdr *hdr = skb_vnet_hdr(head_skb); 305 struct sk_buff *curr_skb = head_skb; 306 char *buf; 307 struct page *page; 308 int num_buf, len, offset; 309 310 num_buf = hdr->mhdr.num_buffers; 311 while (--num_buf) { 312 int num_skb_frags = skb_shinfo(curr_skb)->nr_frags; 313 buf = virtqueue_get_buf(rq->vq, &len); 314 if (unlikely(!buf)) { 315 pr_debug("%s: rx error: %d buffers missing\n", 316 head_skb->dev->name, hdr->mhdr.num_buffers); 317 head_skb->dev->stats.rx_length_errors++; 318 return -EINVAL; 319 } 320 if (unlikely(len > MERGE_BUFFER_LEN)) { 321 pr_debug("%s: rx error: merge buffer too long\n", 322 head_skb->dev->name); 323 len = MERGE_BUFFER_LEN; 324 } 325 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) { 326 struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC); 327 if (unlikely(!nskb)) { 328 head_skb->dev->stats.rx_dropped++; 329 return -ENOMEM; 330 } 331 if (curr_skb == head_skb) 332 skb_shinfo(curr_skb)->frag_list = nskb; 333 else 334 curr_skb->next = nskb; 335 curr_skb = nskb; 336 head_skb->truesize += nskb->truesize; 337 num_skb_frags = 0; 338 } 339 if (curr_skb != head_skb) { 340 head_skb->data_len += len; 341 head_skb->len += len; 342 head_skb->truesize += MERGE_BUFFER_LEN; 343 } 344 page = virt_to_head_page(buf); 345 offset = buf - (char *)page_address(page); 346 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) { 347 put_page(page); 348 skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1, 349 len, MERGE_BUFFER_LEN); 350 } else { 351 skb_add_rx_frag(curr_skb, num_skb_frags, page, 352 offset, len, MERGE_BUFFER_LEN); 353 } 354 --rq->num; 355 } 356 return 0; 357 } 358 359 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) 360 { 361 struct virtnet_info *vi = rq->vq->vdev->priv; 362 struct net_device *dev = vi->dev; 363 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 364 struct sk_buff *skb; 365 struct page *page; 366 struct skb_vnet_hdr *hdr; 367 368 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 369 pr_debug("%s: short packet %i\n", dev->name, len); 370 dev->stats.rx_length_errors++; 371 if (vi->big_packets) 372 give_pages(rq, buf); 373 else if (vi->mergeable_rx_bufs) 374 put_page(virt_to_head_page(buf)); 375 else 376 dev_kfree_skb(buf); 377 return; 378 } 379 380 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 381 skb = buf; 382 len -= sizeof(struct virtio_net_hdr); 383 skb_trim(skb, len); 384 } else if (vi->mergeable_rx_bufs) { 385 struct page *page = virt_to_head_page(buf); 386 skb = page_to_skb(rq, page, 387 (char *)buf - (char *)page_address(page), 388 len, MERGE_BUFFER_LEN); 389 if (unlikely(!skb)) { 390 dev->stats.rx_dropped++; 391 put_page(page); 392 return; 393 } 394 if (receive_mergeable(rq, skb)) { 395 dev_kfree_skb(skb); 396 return; 397 } 398 } else { 399 page = buf; 400 skb = page_to_skb(rq, page, 0, len, PAGE_SIZE); 401 if (unlikely(!skb)) { 402 dev->stats.rx_dropped++; 403 give_pages(rq, page); 404 return; 405 } 406 } 407 408 hdr = skb_vnet_hdr(skb); 409 410 u64_stats_update_begin(&stats->rx_syncp); 411 stats->rx_bytes += skb->len; 412 stats->rx_packets++; 413 u64_stats_update_end(&stats->rx_syncp); 414 415 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 416 pr_debug("Needs csum!\n"); 417 if (!skb_partial_csum_set(skb, 418 hdr->hdr.csum_start, 419 hdr->hdr.csum_offset)) 420 goto frame_err; 421 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 422 skb->ip_summed = CHECKSUM_UNNECESSARY; 423 } 424 425 skb->protocol = eth_type_trans(skb, dev); 426 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 427 ntohs(skb->protocol), skb->len, skb->pkt_type); 428 429 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 430 pr_debug("GSO!\n"); 431 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 432 case VIRTIO_NET_HDR_GSO_TCPV4: 433 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 434 break; 435 case VIRTIO_NET_HDR_GSO_UDP: 436 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 437 break; 438 case VIRTIO_NET_HDR_GSO_TCPV6: 439 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 440 break; 441 default: 442 net_warn_ratelimited("%s: bad gso type %u.\n", 443 dev->name, hdr->hdr.gso_type); 444 goto frame_err; 445 } 446 447 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 448 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 449 450 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 451 if (skb_shinfo(skb)->gso_size == 0) { 452 net_warn_ratelimited("%s: zero gso size.\n", dev->name); 453 goto frame_err; 454 } 455 456 /* Header must be checked, and gso_segs computed. */ 457 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 458 skb_shinfo(skb)->gso_segs = 0; 459 } 460 461 netif_receive_skb(skb); 462 return; 463 464 frame_err: 465 dev->stats.rx_frame_errors++; 466 dev_kfree_skb(skb); 467 } 468 469 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) 470 { 471 struct virtnet_info *vi = rq->vq->vdev->priv; 472 struct sk_buff *skb; 473 struct skb_vnet_hdr *hdr; 474 int err; 475 476 skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp); 477 if (unlikely(!skb)) 478 return -ENOMEM; 479 480 skb_put(skb, GOOD_PACKET_LEN); 481 482 hdr = skb_vnet_hdr(skb); 483 sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); 484 485 skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); 486 487 err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp); 488 if (err < 0) 489 dev_kfree_skb(skb); 490 491 return err; 492 } 493 494 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp) 495 { 496 struct page *first, *list = NULL; 497 char *p; 498 int i, err, offset; 499 500 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ 501 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 502 first = get_a_page(rq, gfp); 503 if (!first) { 504 if (list) 505 give_pages(rq, list); 506 return -ENOMEM; 507 } 508 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE); 509 510 /* chain new page in list head to match sg */ 511 first->private = (unsigned long)list; 512 list = first; 513 } 514 515 first = get_a_page(rq, gfp); 516 if (!first) { 517 give_pages(rq, list); 518 return -ENOMEM; 519 } 520 p = page_address(first); 521 522 /* rq->sg[0], rq->sg[1] share the same page */ 523 /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */ 524 sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr)); 525 526 /* rq->sg[1] for data packet, from offset */ 527 offset = sizeof(struct padded_vnet_hdr); 528 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); 529 530 /* chain first in list head */ 531 first->private = (unsigned long)list; 532 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2, 533 first, gfp); 534 if (err < 0) 535 give_pages(rq, first); 536 537 return err; 538 } 539 540 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) 541 { 542 struct virtnet_info *vi = rq->vq->vdev->priv; 543 char *buf = NULL; 544 int err; 545 546 if (gfp & __GFP_WAIT) { 547 if (skb_page_frag_refill(MERGE_BUFFER_LEN, &vi->alloc_frag, 548 gfp)) { 549 buf = (char *)page_address(vi->alloc_frag.page) + 550 vi->alloc_frag.offset; 551 get_page(vi->alloc_frag.page); 552 vi->alloc_frag.offset += MERGE_BUFFER_LEN; 553 } 554 } else { 555 buf = netdev_alloc_frag(MERGE_BUFFER_LEN); 556 } 557 if (!buf) 558 return -ENOMEM; 559 560 sg_init_one(rq->sg, buf, MERGE_BUFFER_LEN); 561 err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, buf, gfp); 562 if (err < 0) 563 put_page(virt_to_head_page(buf)); 564 565 return err; 566 } 567 568 /* 569 * Returns false if we couldn't fill entirely (OOM). 570 * 571 * Normally run in the receive path, but can also be run from ndo_open 572 * before we're receiving packets, or from refill_work which is 573 * careful to disable receiving (using napi_disable). 574 */ 575 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) 576 { 577 struct virtnet_info *vi = rq->vq->vdev->priv; 578 int err; 579 bool oom; 580 581 do { 582 if (vi->mergeable_rx_bufs) 583 err = add_recvbuf_mergeable(rq, gfp); 584 else if (vi->big_packets) 585 err = add_recvbuf_big(rq, gfp); 586 else 587 err = add_recvbuf_small(rq, gfp); 588 589 oom = err == -ENOMEM; 590 if (err) 591 break; 592 ++rq->num; 593 } while (rq->vq->num_free); 594 if (unlikely(rq->num > rq->max)) 595 rq->max = rq->num; 596 if (unlikely(!virtqueue_kick(rq->vq))) 597 return false; 598 return !oom; 599 } 600 601 static void skb_recv_done(struct virtqueue *rvq) 602 { 603 struct virtnet_info *vi = rvq->vdev->priv; 604 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)]; 605 606 /* Schedule NAPI, Suppress further interrupts if successful. */ 607 if (napi_schedule_prep(&rq->napi)) { 608 virtqueue_disable_cb(rvq); 609 __napi_schedule(&rq->napi); 610 } 611 } 612 613 static void virtnet_napi_enable(struct receive_queue *rq) 614 { 615 napi_enable(&rq->napi); 616 617 /* If all buffers were filled by other side before we napi_enabled, we 618 * won't get another interrupt, so process any outstanding packets 619 * now. virtnet_poll wants re-enable the queue, so we disable here. 620 * We synchronize against interrupts via NAPI_STATE_SCHED */ 621 if (napi_schedule_prep(&rq->napi)) { 622 virtqueue_disable_cb(rq->vq); 623 local_bh_disable(); 624 __napi_schedule(&rq->napi); 625 local_bh_enable(); 626 } 627 } 628 629 static void refill_work(struct work_struct *work) 630 { 631 struct virtnet_info *vi = 632 container_of(work, struct virtnet_info, refill.work); 633 bool still_empty; 634 int i; 635 636 for (i = 0; i < vi->curr_queue_pairs; i++) { 637 struct receive_queue *rq = &vi->rq[i]; 638 639 napi_disable(&rq->napi); 640 still_empty = !try_fill_recv(rq, GFP_KERNEL); 641 virtnet_napi_enable(rq); 642 643 /* In theory, this can happen: if we don't get any buffers in 644 * we will *never* try to fill again. 645 */ 646 if (still_empty) 647 schedule_delayed_work(&vi->refill, HZ/2); 648 } 649 } 650 651 static int virtnet_poll(struct napi_struct *napi, int budget) 652 { 653 struct receive_queue *rq = 654 container_of(napi, struct receive_queue, napi); 655 struct virtnet_info *vi = rq->vq->vdev->priv; 656 void *buf; 657 unsigned int r, len, received = 0; 658 659 again: 660 while (received < budget && 661 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { 662 receive_buf(rq, buf, len); 663 --rq->num; 664 received++; 665 } 666 667 if (rq->num < rq->max / 2) { 668 if (!try_fill_recv(rq, GFP_ATOMIC)) 669 schedule_delayed_work(&vi->refill, 0); 670 } 671 672 /* Out of packets? */ 673 if (received < budget) { 674 r = virtqueue_enable_cb_prepare(rq->vq); 675 napi_complete(napi); 676 if (unlikely(virtqueue_poll(rq->vq, r)) && 677 napi_schedule_prep(napi)) { 678 virtqueue_disable_cb(rq->vq); 679 __napi_schedule(napi); 680 goto again; 681 } 682 } 683 684 return received; 685 } 686 687 static int virtnet_open(struct net_device *dev) 688 { 689 struct virtnet_info *vi = netdev_priv(dev); 690 int i; 691 692 for (i = 0; i < vi->max_queue_pairs; i++) { 693 if (i < vi->curr_queue_pairs) 694 /* Make sure we have some buffers: if oom use wq. */ 695 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 696 schedule_delayed_work(&vi->refill, 0); 697 virtnet_napi_enable(&vi->rq[i]); 698 } 699 700 return 0; 701 } 702 703 static void free_old_xmit_skbs(struct send_queue *sq) 704 { 705 struct sk_buff *skb; 706 unsigned int len; 707 struct virtnet_info *vi = sq->vq->vdev->priv; 708 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 709 710 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { 711 pr_debug("Sent skb %p\n", skb); 712 713 u64_stats_update_begin(&stats->tx_syncp); 714 stats->tx_bytes += skb->len; 715 stats->tx_packets++; 716 u64_stats_update_end(&stats->tx_syncp); 717 718 dev_kfree_skb_any(skb); 719 } 720 } 721 722 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) 723 { 724 struct skb_vnet_hdr *hdr; 725 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 726 struct virtnet_info *vi = sq->vq->vdev->priv; 727 unsigned num_sg; 728 unsigned hdr_len; 729 bool can_push; 730 731 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 732 if (vi->mergeable_rx_bufs) 733 hdr_len = sizeof hdr->mhdr; 734 else 735 hdr_len = sizeof hdr->hdr; 736 737 can_push = vi->any_header_sg && 738 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) && 739 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len; 740 /* Even if we can, don't push here yet as this would skew 741 * csum_start offset below. */ 742 if (can_push) 743 hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len); 744 else 745 hdr = skb_vnet_hdr(skb); 746 747 if (skb->ip_summed == CHECKSUM_PARTIAL) { 748 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 749 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 750 hdr->hdr.csum_offset = skb->csum_offset; 751 } else { 752 hdr->hdr.flags = 0; 753 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 754 } 755 756 if (skb_is_gso(skb)) { 757 hdr->hdr.hdr_len = skb_headlen(skb); 758 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 759 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 760 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 761 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 762 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 763 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 764 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 765 else 766 BUG(); 767 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 768 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 769 } else { 770 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 771 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 772 } 773 774 if (vi->mergeable_rx_bufs) 775 hdr->mhdr.num_buffers = 0; 776 777 if (can_push) { 778 __skb_push(skb, hdr_len); 779 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len); 780 /* Pull header back to avoid skew in tx bytes calculations. */ 781 __skb_pull(skb, hdr_len); 782 } else { 783 sg_set_buf(sq->sg, hdr, hdr_len); 784 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1; 785 } 786 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC); 787 } 788 789 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 790 { 791 struct virtnet_info *vi = netdev_priv(dev); 792 int qnum = skb_get_queue_mapping(skb); 793 struct send_queue *sq = &vi->sq[qnum]; 794 int err; 795 796 /* Free up any pending old buffers before queueing new ones. */ 797 free_old_xmit_skbs(sq); 798 799 /* Try to transmit */ 800 err = xmit_skb(sq, skb); 801 802 /* This should not happen! */ 803 if (unlikely(err) || unlikely(!virtqueue_kick(sq->vq))) { 804 dev->stats.tx_fifo_errors++; 805 if (net_ratelimit()) 806 dev_warn(&dev->dev, 807 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); 808 dev->stats.tx_dropped++; 809 kfree_skb(skb); 810 return NETDEV_TX_OK; 811 } 812 813 /* Don't wait up for transmitted skbs to be freed. */ 814 skb_orphan(skb); 815 nf_reset(skb); 816 817 /* Apparently nice girls don't return TX_BUSY; stop the queue 818 * before it gets out of hand. Naturally, this wastes entries. */ 819 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { 820 netif_stop_subqueue(dev, qnum); 821 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { 822 /* More just got used, free them then recheck. */ 823 free_old_xmit_skbs(sq); 824 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { 825 netif_start_subqueue(dev, qnum); 826 virtqueue_disable_cb(sq->vq); 827 } 828 } 829 } 830 831 return NETDEV_TX_OK; 832 } 833 834 /* 835 * Send command via the control virtqueue and check status. Commands 836 * supported by the hypervisor, as indicated by feature bits, should 837 * never fail unless improperly formated. 838 */ 839 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 840 struct scatterlist *out, 841 struct scatterlist *in) 842 { 843 struct scatterlist *sgs[4], hdr, stat; 844 struct virtio_net_ctrl_hdr ctrl; 845 virtio_net_ctrl_ack status = ~0; 846 unsigned out_num = 0, in_num = 0, tmp; 847 848 /* Caller should know better */ 849 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)); 850 851 ctrl.class = class; 852 ctrl.cmd = cmd; 853 /* Add header */ 854 sg_init_one(&hdr, &ctrl, sizeof(ctrl)); 855 sgs[out_num++] = &hdr; 856 857 if (out) 858 sgs[out_num++] = out; 859 if (in) 860 sgs[out_num + in_num++] = in; 861 862 /* Add return status. */ 863 sg_init_one(&stat, &status, sizeof(status)); 864 sgs[out_num + in_num++] = &stat; 865 866 BUG_ON(out_num + in_num > ARRAY_SIZE(sgs)); 867 BUG_ON(virtqueue_add_sgs(vi->cvq, sgs, out_num, in_num, vi, GFP_ATOMIC) 868 < 0); 869 870 if (unlikely(!virtqueue_kick(vi->cvq))) 871 return status == VIRTIO_NET_OK; 872 873 /* Spin for a response, the kick causes an ioport write, trapping 874 * into the hypervisor, so the request should be handled immediately. 875 */ 876 while (!virtqueue_get_buf(vi->cvq, &tmp) && 877 !virtqueue_is_broken(vi->cvq)) 878 cpu_relax(); 879 880 return status == VIRTIO_NET_OK; 881 } 882 883 static int virtnet_set_mac_address(struct net_device *dev, void *p) 884 { 885 struct virtnet_info *vi = netdev_priv(dev); 886 struct virtio_device *vdev = vi->vdev; 887 int ret; 888 struct sockaddr *addr = p; 889 struct scatterlist sg; 890 891 ret = eth_prepare_mac_addr_change(dev, p); 892 if (ret) 893 return ret; 894 895 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) { 896 sg_init_one(&sg, addr->sa_data, dev->addr_len); 897 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 898 VIRTIO_NET_CTRL_MAC_ADDR_SET, 899 &sg, NULL)) { 900 dev_warn(&vdev->dev, 901 "Failed to set mac address by vq command.\n"); 902 return -EINVAL; 903 } 904 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 905 unsigned int i; 906 907 /* Naturally, this has an atomicity problem. */ 908 for (i = 0; i < dev->addr_len; i++) 909 virtio_cwrite8(vdev, 910 offsetof(struct virtio_net_config, mac) + 911 i, addr->sa_data[i]); 912 } 913 914 eth_commit_mac_addr_change(dev, p); 915 916 return 0; 917 } 918 919 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 920 struct rtnl_link_stats64 *tot) 921 { 922 struct virtnet_info *vi = netdev_priv(dev); 923 int cpu; 924 unsigned int start; 925 926 for_each_possible_cpu(cpu) { 927 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); 928 u64 tpackets, tbytes, rpackets, rbytes; 929 930 do { 931 start = u64_stats_fetch_begin_bh(&stats->tx_syncp); 932 tpackets = stats->tx_packets; 933 tbytes = stats->tx_bytes; 934 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start)); 935 936 do { 937 start = u64_stats_fetch_begin_bh(&stats->rx_syncp); 938 rpackets = stats->rx_packets; 939 rbytes = stats->rx_bytes; 940 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start)); 941 942 tot->rx_packets += rpackets; 943 tot->tx_packets += tpackets; 944 tot->rx_bytes += rbytes; 945 tot->tx_bytes += tbytes; 946 } 947 948 tot->tx_dropped = dev->stats.tx_dropped; 949 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 950 tot->rx_dropped = dev->stats.rx_dropped; 951 tot->rx_length_errors = dev->stats.rx_length_errors; 952 tot->rx_frame_errors = dev->stats.rx_frame_errors; 953 954 return tot; 955 } 956 957 #ifdef CONFIG_NET_POLL_CONTROLLER 958 static void virtnet_netpoll(struct net_device *dev) 959 { 960 struct virtnet_info *vi = netdev_priv(dev); 961 int i; 962 963 for (i = 0; i < vi->curr_queue_pairs; i++) 964 napi_schedule(&vi->rq[i].napi); 965 } 966 #endif 967 968 static void virtnet_ack_link_announce(struct virtnet_info *vi) 969 { 970 rtnl_lock(); 971 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE, 972 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, NULL)) 973 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n"); 974 rtnl_unlock(); 975 } 976 977 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) 978 { 979 struct scatterlist sg; 980 struct virtio_net_ctrl_mq s; 981 struct net_device *dev = vi->dev; 982 983 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) 984 return 0; 985 986 s.virtqueue_pairs = queue_pairs; 987 sg_init_one(&sg, &s, sizeof(s)); 988 989 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ, 990 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, NULL)) { 991 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", 992 queue_pairs); 993 return -EINVAL; 994 } else { 995 vi->curr_queue_pairs = queue_pairs; 996 /* virtnet_open() will refill when device is going to up. */ 997 if (dev->flags & IFF_UP) 998 schedule_delayed_work(&vi->refill, 0); 999 } 1000 1001 return 0; 1002 } 1003 1004 static int virtnet_close(struct net_device *dev) 1005 { 1006 struct virtnet_info *vi = netdev_priv(dev); 1007 int i; 1008 1009 /* Make sure refill_work doesn't re-enable napi! */ 1010 cancel_delayed_work_sync(&vi->refill); 1011 1012 for (i = 0; i < vi->max_queue_pairs; i++) 1013 napi_disable(&vi->rq[i].napi); 1014 1015 return 0; 1016 } 1017 1018 static void virtnet_set_rx_mode(struct net_device *dev) 1019 { 1020 struct virtnet_info *vi = netdev_priv(dev); 1021 struct scatterlist sg[2]; 1022 u8 promisc, allmulti; 1023 struct virtio_net_ctrl_mac *mac_data; 1024 struct netdev_hw_addr *ha; 1025 int uc_count; 1026 int mc_count; 1027 void *buf; 1028 int i; 1029 1030 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 1031 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 1032 return; 1033 1034 promisc = ((dev->flags & IFF_PROMISC) != 0); 1035 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 1036 1037 sg_init_one(sg, &promisc, sizeof(promisc)); 1038 1039 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 1040 VIRTIO_NET_CTRL_RX_PROMISC, 1041 sg, NULL)) 1042 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 1043 promisc ? "en" : "dis"); 1044 1045 sg_init_one(sg, &allmulti, sizeof(allmulti)); 1046 1047 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 1048 VIRTIO_NET_CTRL_RX_ALLMULTI, 1049 sg, NULL)) 1050 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 1051 allmulti ? "en" : "dis"); 1052 1053 uc_count = netdev_uc_count(dev); 1054 mc_count = netdev_mc_count(dev); 1055 /* MAC filter - use one buffer for both lists */ 1056 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 1057 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 1058 mac_data = buf; 1059 if (!buf) 1060 return; 1061 1062 sg_init_table(sg, 2); 1063 1064 /* Store the unicast list and count in the front of the buffer */ 1065 mac_data->entries = uc_count; 1066 i = 0; 1067 netdev_for_each_uc_addr(ha, dev) 1068 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 1069 1070 sg_set_buf(&sg[0], mac_data, 1071 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 1072 1073 /* multicast list and count fill the end */ 1074 mac_data = (void *)&mac_data->macs[uc_count][0]; 1075 1076 mac_data->entries = mc_count; 1077 i = 0; 1078 netdev_for_each_mc_addr(ha, dev) 1079 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 1080 1081 sg_set_buf(&sg[1], mac_data, 1082 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 1083 1084 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 1085 VIRTIO_NET_CTRL_MAC_TABLE_SET, 1086 sg, NULL)) 1087 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 1088 1089 kfree(buf); 1090 } 1091 1092 static int virtnet_vlan_rx_add_vid(struct net_device *dev, 1093 __be16 proto, u16 vid) 1094 { 1095 struct virtnet_info *vi = netdev_priv(dev); 1096 struct scatterlist sg; 1097 1098 sg_init_one(&sg, &vid, sizeof(vid)); 1099 1100 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1101 VIRTIO_NET_CTRL_VLAN_ADD, &sg, NULL)) 1102 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 1103 return 0; 1104 } 1105 1106 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, 1107 __be16 proto, u16 vid) 1108 { 1109 struct virtnet_info *vi = netdev_priv(dev); 1110 struct scatterlist sg; 1111 1112 sg_init_one(&sg, &vid, sizeof(vid)); 1113 1114 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1115 VIRTIO_NET_CTRL_VLAN_DEL, &sg, NULL)) 1116 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 1117 return 0; 1118 } 1119 1120 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu) 1121 { 1122 int i; 1123 1124 if (vi->affinity_hint_set) { 1125 for (i = 0; i < vi->max_queue_pairs; i++) { 1126 virtqueue_set_affinity(vi->rq[i].vq, -1); 1127 virtqueue_set_affinity(vi->sq[i].vq, -1); 1128 } 1129 1130 vi->affinity_hint_set = false; 1131 } 1132 } 1133 1134 static void virtnet_set_affinity(struct virtnet_info *vi) 1135 { 1136 int i; 1137 int cpu; 1138 1139 /* In multiqueue mode, when the number of cpu is equal to the number of 1140 * queue pairs, we let the queue pairs to be private to one cpu by 1141 * setting the affinity hint to eliminate the contention. 1142 */ 1143 if (vi->curr_queue_pairs == 1 || 1144 vi->max_queue_pairs != num_online_cpus()) { 1145 virtnet_clean_affinity(vi, -1); 1146 return; 1147 } 1148 1149 i = 0; 1150 for_each_online_cpu(cpu) { 1151 virtqueue_set_affinity(vi->rq[i].vq, cpu); 1152 virtqueue_set_affinity(vi->sq[i].vq, cpu); 1153 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i); 1154 i++; 1155 } 1156 1157 vi->affinity_hint_set = true; 1158 } 1159 1160 static int virtnet_cpu_callback(struct notifier_block *nfb, 1161 unsigned long action, void *hcpu) 1162 { 1163 struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb); 1164 1165 switch(action & ~CPU_TASKS_FROZEN) { 1166 case CPU_ONLINE: 1167 case CPU_DOWN_FAILED: 1168 case CPU_DEAD: 1169 virtnet_set_affinity(vi); 1170 break; 1171 case CPU_DOWN_PREPARE: 1172 virtnet_clean_affinity(vi, (long)hcpu); 1173 break; 1174 default: 1175 break; 1176 } 1177 1178 return NOTIFY_OK; 1179 } 1180 1181 static void virtnet_get_ringparam(struct net_device *dev, 1182 struct ethtool_ringparam *ring) 1183 { 1184 struct virtnet_info *vi = netdev_priv(dev); 1185 1186 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq); 1187 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq); 1188 ring->rx_pending = ring->rx_max_pending; 1189 ring->tx_pending = ring->tx_max_pending; 1190 } 1191 1192 1193 static void virtnet_get_drvinfo(struct net_device *dev, 1194 struct ethtool_drvinfo *info) 1195 { 1196 struct virtnet_info *vi = netdev_priv(dev); 1197 struct virtio_device *vdev = vi->vdev; 1198 1199 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 1200 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 1201 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 1202 1203 } 1204 1205 /* TODO: Eliminate OOO packets during switching */ 1206 static int virtnet_set_channels(struct net_device *dev, 1207 struct ethtool_channels *channels) 1208 { 1209 struct virtnet_info *vi = netdev_priv(dev); 1210 u16 queue_pairs = channels->combined_count; 1211 int err; 1212 1213 /* We don't support separate rx/tx channels. 1214 * We don't allow setting 'other' channels. 1215 */ 1216 if (channels->rx_count || channels->tx_count || channels->other_count) 1217 return -EINVAL; 1218 1219 if (queue_pairs > vi->max_queue_pairs) 1220 return -EINVAL; 1221 1222 get_online_cpus(); 1223 err = virtnet_set_queues(vi, queue_pairs); 1224 if (!err) { 1225 netif_set_real_num_tx_queues(dev, queue_pairs); 1226 netif_set_real_num_rx_queues(dev, queue_pairs); 1227 1228 virtnet_set_affinity(vi); 1229 } 1230 put_online_cpus(); 1231 1232 return err; 1233 } 1234 1235 static void virtnet_get_channels(struct net_device *dev, 1236 struct ethtool_channels *channels) 1237 { 1238 struct virtnet_info *vi = netdev_priv(dev); 1239 1240 channels->combined_count = vi->curr_queue_pairs; 1241 channels->max_combined = vi->max_queue_pairs; 1242 channels->max_other = 0; 1243 channels->rx_count = 0; 1244 channels->tx_count = 0; 1245 channels->other_count = 0; 1246 } 1247 1248 static const struct ethtool_ops virtnet_ethtool_ops = { 1249 .get_drvinfo = virtnet_get_drvinfo, 1250 .get_link = ethtool_op_get_link, 1251 .get_ringparam = virtnet_get_ringparam, 1252 .set_channels = virtnet_set_channels, 1253 .get_channels = virtnet_get_channels, 1254 }; 1255 1256 #define MIN_MTU 68 1257 #define MAX_MTU 65535 1258 1259 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 1260 { 1261 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 1262 return -EINVAL; 1263 dev->mtu = new_mtu; 1264 return 0; 1265 } 1266 1267 static const struct net_device_ops virtnet_netdev = { 1268 .ndo_open = virtnet_open, 1269 .ndo_stop = virtnet_close, 1270 .ndo_start_xmit = start_xmit, 1271 .ndo_validate_addr = eth_validate_addr, 1272 .ndo_set_mac_address = virtnet_set_mac_address, 1273 .ndo_set_rx_mode = virtnet_set_rx_mode, 1274 .ndo_change_mtu = virtnet_change_mtu, 1275 .ndo_get_stats64 = virtnet_stats, 1276 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 1277 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 1278 #ifdef CONFIG_NET_POLL_CONTROLLER 1279 .ndo_poll_controller = virtnet_netpoll, 1280 #endif 1281 }; 1282 1283 static void virtnet_config_changed_work(struct work_struct *work) 1284 { 1285 struct virtnet_info *vi = 1286 container_of(work, struct virtnet_info, config_work); 1287 u16 v; 1288 1289 mutex_lock(&vi->config_lock); 1290 if (!vi->config_enable) 1291 goto done; 1292 1293 if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS, 1294 struct virtio_net_config, status, &v) < 0) 1295 goto done; 1296 1297 if (v & VIRTIO_NET_S_ANNOUNCE) { 1298 netdev_notify_peers(vi->dev); 1299 virtnet_ack_link_announce(vi); 1300 } 1301 1302 /* Ignore unknown (future) status bits */ 1303 v &= VIRTIO_NET_S_LINK_UP; 1304 1305 if (vi->status == v) 1306 goto done; 1307 1308 vi->status = v; 1309 1310 if (vi->status & VIRTIO_NET_S_LINK_UP) { 1311 netif_carrier_on(vi->dev); 1312 netif_tx_wake_all_queues(vi->dev); 1313 } else { 1314 netif_carrier_off(vi->dev); 1315 netif_tx_stop_all_queues(vi->dev); 1316 } 1317 done: 1318 mutex_unlock(&vi->config_lock); 1319 } 1320 1321 static void virtnet_config_changed(struct virtio_device *vdev) 1322 { 1323 struct virtnet_info *vi = vdev->priv; 1324 1325 schedule_work(&vi->config_work); 1326 } 1327 1328 static void virtnet_free_queues(struct virtnet_info *vi) 1329 { 1330 kfree(vi->rq); 1331 kfree(vi->sq); 1332 } 1333 1334 static void free_receive_bufs(struct virtnet_info *vi) 1335 { 1336 int i; 1337 1338 for (i = 0; i < vi->max_queue_pairs; i++) { 1339 while (vi->rq[i].pages) 1340 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0); 1341 } 1342 } 1343 1344 static void free_unused_bufs(struct virtnet_info *vi) 1345 { 1346 void *buf; 1347 int i; 1348 1349 for (i = 0; i < vi->max_queue_pairs; i++) { 1350 struct virtqueue *vq = vi->sq[i].vq; 1351 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) 1352 dev_kfree_skb(buf); 1353 } 1354 1355 for (i = 0; i < vi->max_queue_pairs; i++) { 1356 struct virtqueue *vq = vi->rq[i].vq; 1357 1358 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { 1359 if (vi->big_packets) 1360 give_pages(&vi->rq[i], buf); 1361 else if (vi->mergeable_rx_bufs) 1362 put_page(virt_to_head_page(buf)); 1363 else 1364 dev_kfree_skb(buf); 1365 --vi->rq[i].num; 1366 } 1367 BUG_ON(vi->rq[i].num != 0); 1368 } 1369 } 1370 1371 static void virtnet_del_vqs(struct virtnet_info *vi) 1372 { 1373 struct virtio_device *vdev = vi->vdev; 1374 1375 virtnet_clean_affinity(vi, -1); 1376 1377 vdev->config->del_vqs(vdev); 1378 1379 virtnet_free_queues(vi); 1380 } 1381 1382 static int virtnet_find_vqs(struct virtnet_info *vi) 1383 { 1384 vq_callback_t **callbacks; 1385 struct virtqueue **vqs; 1386 int ret = -ENOMEM; 1387 int i, total_vqs; 1388 const char **names; 1389 1390 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by 1391 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by 1392 * possible control vq. 1393 */ 1394 total_vqs = vi->max_queue_pairs * 2 + 1395 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); 1396 1397 /* Allocate space for find_vqs parameters */ 1398 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); 1399 if (!vqs) 1400 goto err_vq; 1401 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); 1402 if (!callbacks) 1403 goto err_callback; 1404 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); 1405 if (!names) 1406 goto err_names; 1407 1408 /* Parameters for control virtqueue, if any */ 1409 if (vi->has_cvq) { 1410 callbacks[total_vqs - 1] = NULL; 1411 names[total_vqs - 1] = "control"; 1412 } 1413 1414 /* Allocate/initialize parameters for send/receive virtqueues */ 1415 for (i = 0; i < vi->max_queue_pairs; i++) { 1416 callbacks[rxq2vq(i)] = skb_recv_done; 1417 callbacks[txq2vq(i)] = skb_xmit_done; 1418 sprintf(vi->rq[i].name, "input.%d", i); 1419 sprintf(vi->sq[i].name, "output.%d", i); 1420 names[rxq2vq(i)] = vi->rq[i].name; 1421 names[txq2vq(i)] = vi->sq[i].name; 1422 } 1423 1424 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, 1425 names); 1426 if (ret) 1427 goto err_find; 1428 1429 if (vi->has_cvq) { 1430 vi->cvq = vqs[total_vqs - 1]; 1431 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1432 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER; 1433 } 1434 1435 for (i = 0; i < vi->max_queue_pairs; i++) { 1436 vi->rq[i].vq = vqs[rxq2vq(i)]; 1437 vi->sq[i].vq = vqs[txq2vq(i)]; 1438 } 1439 1440 kfree(names); 1441 kfree(callbacks); 1442 kfree(vqs); 1443 1444 return 0; 1445 1446 err_find: 1447 kfree(names); 1448 err_names: 1449 kfree(callbacks); 1450 err_callback: 1451 kfree(vqs); 1452 err_vq: 1453 return ret; 1454 } 1455 1456 static int virtnet_alloc_queues(struct virtnet_info *vi) 1457 { 1458 int i; 1459 1460 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL); 1461 if (!vi->sq) 1462 goto err_sq; 1463 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL); 1464 if (!vi->rq) 1465 goto err_rq; 1466 1467 INIT_DELAYED_WORK(&vi->refill, refill_work); 1468 for (i = 0; i < vi->max_queue_pairs; i++) { 1469 vi->rq[i].pages = NULL; 1470 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll, 1471 napi_weight); 1472 1473 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); 1474 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); 1475 } 1476 1477 return 0; 1478 1479 err_rq: 1480 kfree(vi->sq); 1481 err_sq: 1482 return -ENOMEM; 1483 } 1484 1485 static int init_vqs(struct virtnet_info *vi) 1486 { 1487 int ret; 1488 1489 /* Allocate send & receive queues */ 1490 ret = virtnet_alloc_queues(vi); 1491 if (ret) 1492 goto err; 1493 1494 ret = virtnet_find_vqs(vi); 1495 if (ret) 1496 goto err_free; 1497 1498 get_online_cpus(); 1499 virtnet_set_affinity(vi); 1500 put_online_cpus(); 1501 1502 return 0; 1503 1504 err_free: 1505 virtnet_free_queues(vi); 1506 err: 1507 return ret; 1508 } 1509 1510 static int virtnet_probe(struct virtio_device *vdev) 1511 { 1512 int i, err; 1513 struct net_device *dev; 1514 struct virtnet_info *vi; 1515 u16 max_queue_pairs; 1516 1517 /* Find if host supports multiqueue virtio_net device */ 1518 err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ, 1519 struct virtio_net_config, 1520 max_virtqueue_pairs, &max_queue_pairs); 1521 1522 /* We need at least 2 queue's */ 1523 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN || 1524 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX || 1525 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1526 max_queue_pairs = 1; 1527 1528 /* Allocate ourselves a network device with room for our info */ 1529 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); 1530 if (!dev) 1531 return -ENOMEM; 1532 1533 /* Set up network device as normal. */ 1534 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE; 1535 dev->netdev_ops = &virtnet_netdev; 1536 dev->features = NETIF_F_HIGHDMA; 1537 1538 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 1539 SET_NETDEV_DEV(dev, &vdev->dev); 1540 1541 /* Do we support "hardware" checksums? */ 1542 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 1543 /* This opens up the world of extra features. */ 1544 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1545 if (csum) 1546 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1547 1548 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 1549 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 1550 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 1551 } 1552 /* Individual feature bits: what can host handle? */ 1553 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 1554 dev->hw_features |= NETIF_F_TSO; 1555 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 1556 dev->hw_features |= NETIF_F_TSO6; 1557 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 1558 dev->hw_features |= NETIF_F_TSO_ECN; 1559 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1560 dev->hw_features |= NETIF_F_UFO; 1561 1562 if (gso) 1563 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1564 /* (!csum && gso) case will be fixed by register_netdev() */ 1565 } 1566 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM)) 1567 dev->features |= NETIF_F_RXCSUM; 1568 1569 dev->vlan_features = dev->features; 1570 1571 /* Configuration may specify what MAC to use. Otherwise random. */ 1572 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 1573 virtio_cread_bytes(vdev, 1574 offsetof(struct virtio_net_config, mac), 1575 dev->dev_addr, dev->addr_len); 1576 else 1577 eth_hw_addr_random(dev); 1578 1579 /* Set up our device-specific information */ 1580 vi = netdev_priv(dev); 1581 vi->dev = dev; 1582 vi->vdev = vdev; 1583 vdev->priv = vi; 1584 vi->stats = alloc_percpu(struct virtnet_stats); 1585 err = -ENOMEM; 1586 if (vi->stats == NULL) 1587 goto free; 1588 1589 for_each_possible_cpu(i) { 1590 struct virtnet_stats *virtnet_stats; 1591 virtnet_stats = per_cpu_ptr(vi->stats, i); 1592 u64_stats_init(&virtnet_stats->tx_syncp); 1593 u64_stats_init(&virtnet_stats->rx_syncp); 1594 } 1595 1596 mutex_init(&vi->config_lock); 1597 vi->config_enable = true; 1598 INIT_WORK(&vi->config_work, virtnet_config_changed_work); 1599 1600 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1601 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1602 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1603 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1604 vi->big_packets = true; 1605 1606 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1607 vi->mergeable_rx_bufs = true; 1608 1609 if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) 1610 vi->any_header_sg = true; 1611 1612 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1613 vi->has_cvq = true; 1614 1615 /* Use single tx/rx queue pair as default */ 1616 vi->curr_queue_pairs = 1; 1617 vi->max_queue_pairs = max_queue_pairs; 1618 1619 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ 1620 err = init_vqs(vi); 1621 if (err) 1622 goto free_stats; 1623 1624 netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs); 1625 netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); 1626 1627 err = register_netdev(dev); 1628 if (err) { 1629 pr_debug("virtio_net: registering device failed\n"); 1630 goto free_vqs; 1631 } 1632 1633 /* Last of all, set up some receive buffers. */ 1634 for (i = 0; i < vi->curr_queue_pairs; i++) { 1635 try_fill_recv(&vi->rq[i], GFP_KERNEL); 1636 1637 /* If we didn't even get one input buffer, we're useless. */ 1638 if (vi->rq[i].num == 0) { 1639 free_unused_bufs(vi); 1640 err = -ENOMEM; 1641 goto free_recv_bufs; 1642 } 1643 } 1644 1645 vi->nb.notifier_call = &virtnet_cpu_callback; 1646 err = register_hotcpu_notifier(&vi->nb); 1647 if (err) { 1648 pr_debug("virtio_net: registering cpu notifier failed\n"); 1649 goto free_recv_bufs; 1650 } 1651 1652 /* Assume link up if device can't report link status, 1653 otherwise get link status from config. */ 1654 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1655 netif_carrier_off(dev); 1656 schedule_work(&vi->config_work); 1657 } else { 1658 vi->status = VIRTIO_NET_S_LINK_UP; 1659 netif_carrier_on(dev); 1660 } 1661 1662 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", 1663 dev->name, max_queue_pairs); 1664 1665 return 0; 1666 1667 free_recv_bufs: 1668 free_receive_bufs(vi); 1669 unregister_netdev(dev); 1670 free_vqs: 1671 cancel_delayed_work_sync(&vi->refill); 1672 virtnet_del_vqs(vi); 1673 if (vi->alloc_frag.page) 1674 put_page(vi->alloc_frag.page); 1675 free_stats: 1676 free_percpu(vi->stats); 1677 free: 1678 free_netdev(dev); 1679 return err; 1680 } 1681 1682 static void remove_vq_common(struct virtnet_info *vi) 1683 { 1684 vi->vdev->config->reset(vi->vdev); 1685 1686 /* Free unused buffers in both send and recv, if any. */ 1687 free_unused_bufs(vi); 1688 1689 free_receive_bufs(vi); 1690 1691 virtnet_del_vqs(vi); 1692 } 1693 1694 static void virtnet_remove(struct virtio_device *vdev) 1695 { 1696 struct virtnet_info *vi = vdev->priv; 1697 1698 unregister_hotcpu_notifier(&vi->nb); 1699 1700 /* Prevent config work handler from accessing the device. */ 1701 mutex_lock(&vi->config_lock); 1702 vi->config_enable = false; 1703 mutex_unlock(&vi->config_lock); 1704 1705 unregister_netdev(vi->dev); 1706 1707 remove_vq_common(vi); 1708 if (vi->alloc_frag.page) 1709 put_page(vi->alloc_frag.page); 1710 1711 flush_work(&vi->config_work); 1712 1713 free_percpu(vi->stats); 1714 free_netdev(vi->dev); 1715 } 1716 1717 #ifdef CONFIG_PM_SLEEP 1718 static int virtnet_freeze(struct virtio_device *vdev) 1719 { 1720 struct virtnet_info *vi = vdev->priv; 1721 int i; 1722 1723 unregister_hotcpu_notifier(&vi->nb); 1724 1725 /* Prevent config work handler from accessing the device */ 1726 mutex_lock(&vi->config_lock); 1727 vi->config_enable = false; 1728 mutex_unlock(&vi->config_lock); 1729 1730 netif_device_detach(vi->dev); 1731 cancel_delayed_work_sync(&vi->refill); 1732 1733 if (netif_running(vi->dev)) 1734 for (i = 0; i < vi->max_queue_pairs; i++) { 1735 napi_disable(&vi->rq[i].napi); 1736 netif_napi_del(&vi->rq[i].napi); 1737 } 1738 1739 remove_vq_common(vi); 1740 1741 flush_work(&vi->config_work); 1742 1743 return 0; 1744 } 1745 1746 static int virtnet_restore(struct virtio_device *vdev) 1747 { 1748 struct virtnet_info *vi = vdev->priv; 1749 int err, i; 1750 1751 err = init_vqs(vi); 1752 if (err) 1753 return err; 1754 1755 if (netif_running(vi->dev)) 1756 for (i = 0; i < vi->max_queue_pairs; i++) 1757 virtnet_napi_enable(&vi->rq[i]); 1758 1759 netif_device_attach(vi->dev); 1760 1761 for (i = 0; i < vi->curr_queue_pairs; i++) 1762 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 1763 schedule_delayed_work(&vi->refill, 0); 1764 1765 mutex_lock(&vi->config_lock); 1766 vi->config_enable = true; 1767 mutex_unlock(&vi->config_lock); 1768 1769 rtnl_lock(); 1770 virtnet_set_queues(vi, vi->curr_queue_pairs); 1771 rtnl_unlock(); 1772 1773 err = register_hotcpu_notifier(&vi->nb); 1774 if (err) 1775 return err; 1776 1777 return 0; 1778 } 1779 #endif 1780 1781 static struct virtio_device_id id_table[] = { 1782 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1783 { 0 }, 1784 }; 1785 1786 static unsigned int features[] = { 1787 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1788 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1789 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1790 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1791 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1792 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1793 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1794 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, 1795 VIRTIO_NET_F_CTRL_MAC_ADDR, 1796 VIRTIO_F_ANY_LAYOUT, 1797 }; 1798 1799 static struct virtio_driver virtio_net_driver = { 1800 .feature_table = features, 1801 .feature_table_size = ARRAY_SIZE(features), 1802 .driver.name = KBUILD_MODNAME, 1803 .driver.owner = THIS_MODULE, 1804 .id_table = id_table, 1805 .probe = virtnet_probe, 1806 .remove = virtnet_remove, 1807 .config_changed = virtnet_config_changed, 1808 #ifdef CONFIG_PM_SLEEP 1809 .freeze = virtnet_freeze, 1810 .restore = virtnet_restore, 1811 #endif 1812 }; 1813 1814 module_virtio_driver(virtio_net_driver); 1815 1816 MODULE_DEVICE_TABLE(virtio, id_table); 1817 MODULE_DESCRIPTION("Virtio network driver"); 1818 MODULE_LICENSE("GPL"); 1819