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