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 30 static int napi_weight = 128; 31 module_param(napi_weight, int, 0444); 32 33 static int csum = 1, gso = 1; 34 module_param(csum, bool, 0444); 35 module_param(gso, bool, 0444); 36 37 /* FIXME: MTU in config. */ 38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 39 #define GOOD_COPY_LEN 128 40 41 #define VIRTNET_SEND_COMMAND_SG_MAX 2 42 43 struct virtnet_stats { 44 struct u64_stats_sync syncp; 45 u64 tx_bytes; 46 u64 tx_packets; 47 48 u64 rx_bytes; 49 u64 rx_packets; 50 }; 51 52 struct virtnet_info { 53 struct virtio_device *vdev; 54 struct virtqueue *rvq, *svq, *cvq; 55 struct net_device *dev; 56 struct napi_struct napi; 57 unsigned int status; 58 59 /* Number of input buffers, and max we've ever had. */ 60 unsigned int num, max; 61 62 /* I like... big packets and I cannot lie! */ 63 bool big_packets; 64 65 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 66 bool mergeable_rx_bufs; 67 68 /* Active statistics */ 69 struct virtnet_stats __percpu *stats; 70 71 /* Work struct for refilling if we run low on memory. */ 72 struct delayed_work refill; 73 74 /* Chain pages by the private ptr. */ 75 struct page *pages; 76 77 /* fragments + linear part + virtio header */ 78 struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; 79 struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; 80 }; 81 82 struct skb_vnet_hdr { 83 union { 84 struct virtio_net_hdr hdr; 85 struct virtio_net_hdr_mrg_rxbuf mhdr; 86 }; 87 unsigned int num_sg; 88 }; 89 90 struct padded_vnet_hdr { 91 struct virtio_net_hdr hdr; 92 /* 93 * virtio_net_hdr should be in a separated sg buffer because of a 94 * QEMU bug, and data sg buffer shares same page with this header sg. 95 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 96 */ 97 char padding[6]; 98 }; 99 100 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 101 { 102 return (struct skb_vnet_hdr *)skb->cb; 103 } 104 105 /* 106 * private is used to chain pages for big packets, put the whole 107 * most recent used list in the beginning for reuse 108 */ 109 static void give_pages(struct virtnet_info *vi, struct page *page) 110 { 111 struct page *end; 112 113 /* Find end of list, sew whole thing into vi->pages. */ 114 for (end = page; end->private; end = (struct page *)end->private); 115 end->private = (unsigned long)vi->pages; 116 vi->pages = page; 117 } 118 119 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 120 { 121 struct page *p = vi->pages; 122 123 if (p) { 124 vi->pages = (struct page *)p->private; 125 /* clear private here, it is used to chain pages */ 126 p->private = 0; 127 } else 128 p = alloc_page(gfp_mask); 129 return p; 130 } 131 132 static void skb_xmit_done(struct virtqueue *svq) 133 { 134 struct virtnet_info *vi = svq->vdev->priv; 135 136 /* Suppress further interrupts. */ 137 virtqueue_disable_cb(svq); 138 139 /* We were probably waiting for more output buffers. */ 140 netif_wake_queue(vi->dev); 141 } 142 143 static void set_skb_frag(struct sk_buff *skb, struct page *page, 144 unsigned int offset, unsigned int *len) 145 { 146 int i = skb_shinfo(skb)->nr_frags; 147 skb_frag_t *f; 148 149 f = &skb_shinfo(skb)->frags[i]; 150 f->size = min((unsigned)PAGE_SIZE - offset, *len); 151 f->page_offset = offset; 152 f->page = page; 153 154 skb->data_len += f->size; 155 skb->len += f->size; 156 skb_shinfo(skb)->nr_frags++; 157 *len -= f->size; 158 } 159 160 static struct sk_buff *page_to_skb(struct virtnet_info *vi, 161 struct page *page, unsigned int len) 162 { 163 struct sk_buff *skb; 164 struct skb_vnet_hdr *hdr; 165 unsigned int copy, hdr_len, offset; 166 char *p; 167 168 p = page_address(page); 169 170 /* copy small packet so we can reuse these pages for small data */ 171 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 172 if (unlikely(!skb)) 173 return NULL; 174 175 hdr = skb_vnet_hdr(skb); 176 177 if (vi->mergeable_rx_bufs) { 178 hdr_len = sizeof hdr->mhdr; 179 offset = hdr_len; 180 } else { 181 hdr_len = sizeof hdr->hdr; 182 offset = sizeof(struct padded_vnet_hdr); 183 } 184 185 memcpy(hdr, p, hdr_len); 186 187 len -= hdr_len; 188 p += offset; 189 190 copy = len; 191 if (copy > skb_tailroom(skb)) 192 copy = skb_tailroom(skb); 193 memcpy(skb_put(skb, copy), p, copy); 194 195 len -= copy; 196 offset += copy; 197 198 while (len) { 199 set_skb_frag(skb, page, offset, &len); 200 page = (struct page *)page->private; 201 offset = 0; 202 } 203 204 if (page) 205 give_pages(vi, page); 206 207 return skb; 208 } 209 210 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) 211 { 212 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 213 struct page *page; 214 int num_buf, i, len; 215 216 num_buf = hdr->mhdr.num_buffers; 217 while (--num_buf) { 218 i = skb_shinfo(skb)->nr_frags; 219 if (i >= MAX_SKB_FRAGS) { 220 pr_debug("%s: packet too long\n", skb->dev->name); 221 skb->dev->stats.rx_length_errors++; 222 return -EINVAL; 223 } 224 page = virtqueue_get_buf(vi->rvq, &len); 225 if (!page) { 226 pr_debug("%s: rx error: %d buffers missing\n", 227 skb->dev->name, hdr->mhdr.num_buffers); 228 skb->dev->stats.rx_length_errors++; 229 return -EINVAL; 230 } 231 232 if (len > PAGE_SIZE) 233 len = PAGE_SIZE; 234 235 set_skb_frag(skb, page, 0, &len); 236 237 --vi->num; 238 } 239 return 0; 240 } 241 242 static void receive_buf(struct net_device *dev, void *buf, unsigned int len) 243 { 244 struct virtnet_info *vi = netdev_priv(dev); 245 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 246 struct sk_buff *skb; 247 struct page *page; 248 struct skb_vnet_hdr *hdr; 249 250 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 251 pr_debug("%s: short packet %i\n", dev->name, len); 252 dev->stats.rx_length_errors++; 253 if (vi->mergeable_rx_bufs || vi->big_packets) 254 give_pages(vi, buf); 255 else 256 dev_kfree_skb(buf); 257 return; 258 } 259 260 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 261 skb = buf; 262 len -= sizeof(struct virtio_net_hdr); 263 skb_trim(skb, len); 264 } else { 265 page = buf; 266 skb = page_to_skb(vi, page, len); 267 if (unlikely(!skb)) { 268 dev->stats.rx_dropped++; 269 give_pages(vi, page); 270 return; 271 } 272 if (vi->mergeable_rx_bufs) 273 if (receive_mergeable(vi, skb)) { 274 dev_kfree_skb(skb); 275 return; 276 } 277 } 278 279 hdr = skb_vnet_hdr(skb); 280 skb->truesize += skb->data_len; 281 282 u64_stats_update_begin(&stats->syncp); 283 stats->rx_bytes += skb->len; 284 stats->rx_packets++; 285 u64_stats_update_end(&stats->syncp); 286 287 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 288 pr_debug("Needs csum!\n"); 289 if (!skb_partial_csum_set(skb, 290 hdr->hdr.csum_start, 291 hdr->hdr.csum_offset)) 292 goto frame_err; 293 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 294 skb->ip_summed = CHECKSUM_UNNECESSARY; 295 } 296 297 skb->protocol = eth_type_trans(skb, dev); 298 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 299 ntohs(skb->protocol), skb->len, skb->pkt_type); 300 301 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 302 pr_debug("GSO!\n"); 303 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 304 case VIRTIO_NET_HDR_GSO_TCPV4: 305 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 306 break; 307 case VIRTIO_NET_HDR_GSO_UDP: 308 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 309 break; 310 case VIRTIO_NET_HDR_GSO_TCPV6: 311 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 312 break; 313 default: 314 if (net_ratelimit()) 315 printk(KERN_WARNING "%s: bad gso type %u.\n", 316 dev->name, hdr->hdr.gso_type); 317 goto frame_err; 318 } 319 320 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 321 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 322 323 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 324 if (skb_shinfo(skb)->gso_size == 0) { 325 if (net_ratelimit()) 326 printk(KERN_WARNING "%s: zero gso size.\n", 327 dev->name); 328 goto frame_err; 329 } 330 331 /* Header must be checked, and gso_segs computed. */ 332 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 333 skb_shinfo(skb)->gso_segs = 0; 334 } 335 336 netif_receive_skb(skb); 337 return; 338 339 frame_err: 340 dev->stats.rx_frame_errors++; 341 dev_kfree_skb(skb); 342 } 343 344 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) 345 { 346 struct sk_buff *skb; 347 struct skb_vnet_hdr *hdr; 348 int err; 349 350 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); 351 if (unlikely(!skb)) 352 return -ENOMEM; 353 354 skb_put(skb, MAX_PACKET_LEN); 355 356 hdr = skb_vnet_hdr(skb); 357 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); 358 359 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); 360 361 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); 362 if (err < 0) 363 dev_kfree_skb(skb); 364 365 return err; 366 } 367 368 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 369 { 370 struct page *first, *list = NULL; 371 char *p; 372 int i, err, offset; 373 374 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ 375 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 376 first = get_a_page(vi, gfp); 377 if (!first) { 378 if (list) 379 give_pages(vi, list); 380 return -ENOMEM; 381 } 382 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); 383 384 /* chain new page in list head to match sg */ 385 first->private = (unsigned long)list; 386 list = first; 387 } 388 389 first = get_a_page(vi, gfp); 390 if (!first) { 391 give_pages(vi, list); 392 return -ENOMEM; 393 } 394 p = page_address(first); 395 396 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ 397 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ 398 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); 399 400 /* vi->rx_sg[1] for data packet, from offset */ 401 offset = sizeof(struct padded_vnet_hdr); 402 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); 403 404 /* chain first in list head */ 405 first->private = (unsigned long)list; 406 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, 407 first, gfp); 408 if (err < 0) 409 give_pages(vi, first); 410 411 return err; 412 } 413 414 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 415 { 416 struct page *page; 417 int err; 418 419 page = get_a_page(vi, gfp); 420 if (!page) 421 return -ENOMEM; 422 423 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); 424 425 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp); 426 if (err < 0) 427 give_pages(vi, page); 428 429 return err; 430 } 431 432 /* Returns false if we couldn't fill entirely (OOM). */ 433 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 434 { 435 int err; 436 bool oom; 437 438 do { 439 if (vi->mergeable_rx_bufs) 440 err = add_recvbuf_mergeable(vi, gfp); 441 else if (vi->big_packets) 442 err = add_recvbuf_big(vi, gfp); 443 else 444 err = add_recvbuf_small(vi, gfp); 445 446 oom = err == -ENOMEM; 447 if (err < 0) 448 break; 449 ++vi->num; 450 } while (err > 0); 451 if (unlikely(vi->num > vi->max)) 452 vi->max = vi->num; 453 virtqueue_kick(vi->rvq); 454 return !oom; 455 } 456 457 static void skb_recv_done(struct virtqueue *rvq) 458 { 459 struct virtnet_info *vi = rvq->vdev->priv; 460 /* Schedule NAPI, Suppress further interrupts if successful. */ 461 if (napi_schedule_prep(&vi->napi)) { 462 virtqueue_disable_cb(rvq); 463 __napi_schedule(&vi->napi); 464 } 465 } 466 467 static void virtnet_napi_enable(struct virtnet_info *vi) 468 { 469 napi_enable(&vi->napi); 470 471 /* If all buffers were filled by other side before we napi_enabled, we 472 * won't get another interrupt, so process any outstanding packets 473 * now. virtnet_poll wants re-enable the queue, so we disable here. 474 * We synchronize against interrupts via NAPI_STATE_SCHED */ 475 if (napi_schedule_prep(&vi->napi)) { 476 virtqueue_disable_cb(vi->rvq); 477 __napi_schedule(&vi->napi); 478 } 479 } 480 481 static void refill_work(struct work_struct *work) 482 { 483 struct virtnet_info *vi; 484 bool still_empty; 485 486 vi = container_of(work, struct virtnet_info, refill.work); 487 napi_disable(&vi->napi); 488 still_empty = !try_fill_recv(vi, GFP_KERNEL); 489 virtnet_napi_enable(vi); 490 491 /* In theory, this can happen: if we don't get any buffers in 492 * we will *never* try to fill again. */ 493 if (still_empty) 494 schedule_delayed_work(&vi->refill, HZ/2); 495 } 496 497 static int virtnet_poll(struct napi_struct *napi, int budget) 498 { 499 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 500 void *buf; 501 unsigned int len, received = 0; 502 503 again: 504 while (received < budget && 505 (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) { 506 receive_buf(vi->dev, buf, len); 507 --vi->num; 508 received++; 509 } 510 511 if (vi->num < vi->max / 2) { 512 if (!try_fill_recv(vi, GFP_ATOMIC)) 513 schedule_delayed_work(&vi->refill, 0); 514 } 515 516 /* Out of packets? */ 517 if (received < budget) { 518 napi_complete(napi); 519 if (unlikely(!virtqueue_enable_cb(vi->rvq)) && 520 napi_schedule_prep(napi)) { 521 virtqueue_disable_cb(vi->rvq); 522 __napi_schedule(napi); 523 goto again; 524 } 525 } 526 527 return received; 528 } 529 530 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) 531 { 532 struct sk_buff *skb; 533 unsigned int len, tot_sgs = 0; 534 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 535 536 while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { 537 pr_debug("Sent skb %p\n", skb); 538 539 u64_stats_update_begin(&stats->syncp); 540 stats->tx_bytes += skb->len; 541 stats->tx_packets++; 542 u64_stats_update_end(&stats->syncp); 543 544 tot_sgs += skb_vnet_hdr(skb)->num_sg; 545 dev_kfree_skb_any(skb); 546 } 547 return tot_sgs; 548 } 549 550 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 551 { 552 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 553 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 554 555 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 556 557 if (skb->ip_summed == CHECKSUM_PARTIAL) { 558 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 559 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 560 hdr->hdr.csum_offset = skb->csum_offset; 561 } else { 562 hdr->hdr.flags = 0; 563 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 564 } 565 566 if (skb_is_gso(skb)) { 567 hdr->hdr.hdr_len = skb_headlen(skb); 568 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 569 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 570 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 571 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 572 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 573 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 574 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 575 else 576 BUG(); 577 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 578 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 579 } else { 580 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 581 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 582 } 583 584 hdr->mhdr.num_buffers = 0; 585 586 /* Encode metadata header at front. */ 587 if (vi->mergeable_rx_bufs) 588 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); 589 else 590 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); 591 592 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; 593 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, 594 0, skb); 595 } 596 597 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 598 { 599 struct virtnet_info *vi = netdev_priv(dev); 600 int capacity; 601 602 /* Free up any pending old buffers before queueing new ones. */ 603 free_old_xmit_skbs(vi); 604 605 /* Try to transmit */ 606 capacity = xmit_skb(vi, skb); 607 608 /* This can happen with OOM and indirect buffers. */ 609 if (unlikely(capacity < 0)) { 610 if (net_ratelimit()) { 611 if (likely(capacity == -ENOMEM)) { 612 dev_warn(&dev->dev, 613 "TX queue failure: out of memory\n"); 614 } else { 615 dev->stats.tx_fifo_errors++; 616 dev_warn(&dev->dev, 617 "Unexpected TX queue failure: %d\n", 618 capacity); 619 } 620 } 621 dev->stats.tx_dropped++; 622 kfree_skb(skb); 623 return NETDEV_TX_OK; 624 } 625 virtqueue_kick(vi->svq); 626 627 /* Don't wait up for transmitted skbs to be freed. */ 628 skb_orphan(skb); 629 nf_reset(skb); 630 631 /* Apparently nice girls don't return TX_BUSY; stop the queue 632 * before it gets out of hand. Naturally, this wastes entries. */ 633 if (capacity < 2+MAX_SKB_FRAGS) { 634 netif_stop_queue(dev); 635 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { 636 /* More just got used, free them then recheck. */ 637 capacity += free_old_xmit_skbs(vi); 638 if (capacity >= 2+MAX_SKB_FRAGS) { 639 netif_start_queue(dev); 640 virtqueue_disable_cb(vi->svq); 641 } 642 } 643 } 644 645 return NETDEV_TX_OK; 646 } 647 648 static int virtnet_set_mac_address(struct net_device *dev, void *p) 649 { 650 struct virtnet_info *vi = netdev_priv(dev); 651 struct virtio_device *vdev = vi->vdev; 652 int ret; 653 654 ret = eth_mac_addr(dev, p); 655 if (ret) 656 return ret; 657 658 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 659 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 660 dev->dev_addr, dev->addr_len); 661 662 return 0; 663 } 664 665 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 666 struct rtnl_link_stats64 *tot) 667 { 668 struct virtnet_info *vi = netdev_priv(dev); 669 int cpu; 670 unsigned int start; 671 672 for_each_possible_cpu(cpu) { 673 struct virtnet_stats __percpu *stats 674 = per_cpu_ptr(vi->stats, cpu); 675 u64 tpackets, tbytes, rpackets, rbytes; 676 677 do { 678 start = u64_stats_fetch_begin(&stats->syncp); 679 tpackets = stats->tx_packets; 680 tbytes = stats->tx_bytes; 681 rpackets = stats->rx_packets; 682 rbytes = stats->rx_bytes; 683 } while (u64_stats_fetch_retry(&stats->syncp, start)); 684 685 tot->rx_packets += rpackets; 686 tot->tx_packets += tpackets; 687 tot->rx_bytes += rbytes; 688 tot->tx_bytes += tbytes; 689 } 690 691 tot->tx_dropped = dev->stats.tx_dropped; 692 tot->rx_dropped = dev->stats.rx_dropped; 693 tot->rx_length_errors = dev->stats.rx_length_errors; 694 tot->rx_frame_errors = dev->stats.rx_frame_errors; 695 696 return tot; 697 } 698 699 #ifdef CONFIG_NET_POLL_CONTROLLER 700 static void virtnet_netpoll(struct net_device *dev) 701 { 702 struct virtnet_info *vi = netdev_priv(dev); 703 704 napi_schedule(&vi->napi); 705 } 706 #endif 707 708 static int virtnet_open(struct net_device *dev) 709 { 710 struct virtnet_info *vi = netdev_priv(dev); 711 712 virtnet_napi_enable(vi); 713 return 0; 714 } 715 716 /* 717 * Send command via the control virtqueue and check status. Commands 718 * supported by the hypervisor, as indicated by feature bits, should 719 * never fail unless improperly formated. 720 */ 721 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 722 struct scatterlist *data, int out, int in) 723 { 724 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 725 struct virtio_net_ctrl_hdr ctrl; 726 virtio_net_ctrl_ack status = ~0; 727 unsigned int tmp; 728 int i; 729 730 /* Caller should know better */ 731 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 732 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 733 734 out++; /* Add header */ 735 in++; /* Add return status */ 736 737 ctrl.class = class; 738 ctrl.cmd = cmd; 739 740 sg_init_table(sg, out + in); 741 742 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 743 for_each_sg(data, s, out + in - 2, i) 744 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 745 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 746 747 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0); 748 749 virtqueue_kick(vi->cvq); 750 751 /* 752 * Spin for a response, the kick causes an ioport write, trapping 753 * into the hypervisor, so the request should be handled immediately. 754 */ 755 while (!virtqueue_get_buf(vi->cvq, &tmp)) 756 cpu_relax(); 757 758 return status == VIRTIO_NET_OK; 759 } 760 761 static int virtnet_close(struct net_device *dev) 762 { 763 struct virtnet_info *vi = netdev_priv(dev); 764 765 napi_disable(&vi->napi); 766 767 return 0; 768 } 769 770 static void virtnet_set_rx_mode(struct net_device *dev) 771 { 772 struct virtnet_info *vi = netdev_priv(dev); 773 struct scatterlist sg[2]; 774 u8 promisc, allmulti; 775 struct virtio_net_ctrl_mac *mac_data; 776 struct netdev_hw_addr *ha; 777 int uc_count; 778 int mc_count; 779 void *buf; 780 int i; 781 782 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 783 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 784 return; 785 786 promisc = ((dev->flags & IFF_PROMISC) != 0); 787 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 788 789 sg_init_one(sg, &promisc, sizeof(promisc)); 790 791 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 792 VIRTIO_NET_CTRL_RX_PROMISC, 793 sg, 1, 0)) 794 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 795 promisc ? "en" : "dis"); 796 797 sg_init_one(sg, &allmulti, sizeof(allmulti)); 798 799 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 800 VIRTIO_NET_CTRL_RX_ALLMULTI, 801 sg, 1, 0)) 802 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 803 allmulti ? "en" : "dis"); 804 805 uc_count = netdev_uc_count(dev); 806 mc_count = netdev_mc_count(dev); 807 /* MAC filter - use one buffer for both lists */ 808 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 809 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 810 mac_data = buf; 811 if (!buf) { 812 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 813 return; 814 } 815 816 sg_init_table(sg, 2); 817 818 /* Store the unicast list and count in the front of the buffer */ 819 mac_data->entries = uc_count; 820 i = 0; 821 netdev_for_each_uc_addr(ha, dev) 822 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 823 824 sg_set_buf(&sg[0], mac_data, 825 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 826 827 /* multicast list and count fill the end */ 828 mac_data = (void *)&mac_data->macs[uc_count][0]; 829 830 mac_data->entries = mc_count; 831 i = 0; 832 netdev_for_each_mc_addr(ha, dev) 833 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 834 835 sg_set_buf(&sg[1], mac_data, 836 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 837 838 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 839 VIRTIO_NET_CTRL_MAC_TABLE_SET, 840 sg, 2, 0)) 841 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 842 843 kfree(buf); 844 } 845 846 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 847 { 848 struct virtnet_info *vi = netdev_priv(dev); 849 struct scatterlist sg; 850 851 sg_init_one(&sg, &vid, sizeof(vid)); 852 853 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 854 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 855 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 856 } 857 858 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 859 { 860 struct virtnet_info *vi = netdev_priv(dev); 861 struct scatterlist sg; 862 863 sg_init_one(&sg, &vid, sizeof(vid)); 864 865 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 866 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 867 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 868 } 869 870 static const struct ethtool_ops virtnet_ethtool_ops = { 871 .get_link = ethtool_op_get_link, 872 }; 873 874 #define MIN_MTU 68 875 #define MAX_MTU 65535 876 877 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 878 { 879 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 880 return -EINVAL; 881 dev->mtu = new_mtu; 882 return 0; 883 } 884 885 static const struct net_device_ops virtnet_netdev = { 886 .ndo_open = virtnet_open, 887 .ndo_stop = virtnet_close, 888 .ndo_start_xmit = start_xmit, 889 .ndo_validate_addr = eth_validate_addr, 890 .ndo_set_mac_address = virtnet_set_mac_address, 891 .ndo_set_rx_mode = virtnet_set_rx_mode, 892 .ndo_change_mtu = virtnet_change_mtu, 893 .ndo_get_stats64 = virtnet_stats, 894 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 895 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 896 #ifdef CONFIG_NET_POLL_CONTROLLER 897 .ndo_poll_controller = virtnet_netpoll, 898 #endif 899 }; 900 901 static void virtnet_update_status(struct virtnet_info *vi) 902 { 903 u16 v; 904 905 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 906 return; 907 908 vi->vdev->config->get(vi->vdev, 909 offsetof(struct virtio_net_config, status), 910 &v, sizeof(v)); 911 912 /* Ignore unknown (future) status bits */ 913 v &= VIRTIO_NET_S_LINK_UP; 914 915 if (vi->status == v) 916 return; 917 918 vi->status = v; 919 920 if (vi->status & VIRTIO_NET_S_LINK_UP) { 921 netif_carrier_on(vi->dev); 922 netif_wake_queue(vi->dev); 923 } else { 924 netif_carrier_off(vi->dev); 925 netif_stop_queue(vi->dev); 926 } 927 } 928 929 static void virtnet_config_changed(struct virtio_device *vdev) 930 { 931 struct virtnet_info *vi = vdev->priv; 932 933 virtnet_update_status(vi); 934 } 935 936 static int virtnet_probe(struct virtio_device *vdev) 937 { 938 int err; 939 struct net_device *dev; 940 struct virtnet_info *vi; 941 struct virtqueue *vqs[3]; 942 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 943 const char *names[] = { "input", "output", "control" }; 944 int nvqs; 945 946 /* Allocate ourselves a network device with room for our info */ 947 dev = alloc_etherdev(sizeof(struct virtnet_info)); 948 if (!dev) 949 return -ENOMEM; 950 951 /* Set up network device as normal. */ 952 dev->netdev_ops = &virtnet_netdev; 953 dev->features = NETIF_F_HIGHDMA; 954 955 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 956 SET_NETDEV_DEV(dev, &vdev->dev); 957 958 /* Do we support "hardware" checksums? */ 959 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 960 /* This opens up the world of extra features. */ 961 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 962 if (csum) 963 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 964 965 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 966 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 967 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 968 } 969 /* Individual feature bits: what can host handle? */ 970 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 971 dev->hw_features |= NETIF_F_TSO; 972 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 973 dev->hw_features |= NETIF_F_TSO6; 974 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 975 dev->hw_features |= NETIF_F_TSO_ECN; 976 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 977 dev->hw_features |= NETIF_F_UFO; 978 979 if (gso) 980 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 981 /* (!csum && gso) case will be fixed by register_netdev() */ 982 } 983 984 /* Configuration may specify what MAC to use. Otherwise random. */ 985 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 986 vdev->config->get(vdev, 987 offsetof(struct virtio_net_config, mac), 988 dev->dev_addr, dev->addr_len); 989 } else 990 random_ether_addr(dev->dev_addr); 991 992 /* Set up our device-specific information */ 993 vi = netdev_priv(dev); 994 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 995 vi->dev = dev; 996 vi->vdev = vdev; 997 vdev->priv = vi; 998 vi->pages = NULL; 999 vi->stats = alloc_percpu(struct virtnet_stats); 1000 err = -ENOMEM; 1001 if (vi->stats == NULL) 1002 goto free; 1003 1004 INIT_DELAYED_WORK(&vi->refill, refill_work); 1005 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); 1006 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); 1007 1008 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1009 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1010 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1011 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1012 vi->big_packets = true; 1013 1014 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1015 vi->mergeable_rx_bufs = true; 1016 1017 /* We expect two virtqueues, receive then send, 1018 * and optionally control. */ 1019 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 1020 1021 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 1022 if (err) 1023 goto free_stats; 1024 1025 vi->rvq = vqs[0]; 1026 vi->svq = vqs[1]; 1027 1028 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 1029 vi->cvq = vqs[2]; 1030 1031 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1032 dev->features |= NETIF_F_HW_VLAN_FILTER; 1033 } 1034 1035 err = register_netdev(dev); 1036 if (err) { 1037 pr_debug("virtio_net: registering device failed\n"); 1038 goto free_vqs; 1039 } 1040 1041 /* Last of all, set up some receive buffers. */ 1042 try_fill_recv(vi, GFP_KERNEL); 1043 1044 /* If we didn't even get one input buffer, we're useless. */ 1045 if (vi->num == 0) { 1046 err = -ENOMEM; 1047 goto unregister; 1048 } 1049 1050 /* Assume link up if device can't report link status, 1051 otherwise get link status from config. */ 1052 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1053 netif_carrier_off(dev); 1054 virtnet_update_status(vi); 1055 } else { 1056 vi->status = VIRTIO_NET_S_LINK_UP; 1057 netif_carrier_on(dev); 1058 } 1059 1060 pr_debug("virtnet: registered device %s\n", dev->name); 1061 return 0; 1062 1063 unregister: 1064 unregister_netdev(dev); 1065 cancel_delayed_work_sync(&vi->refill); 1066 free_vqs: 1067 vdev->config->del_vqs(vdev); 1068 free_stats: 1069 free_percpu(vi->stats); 1070 free: 1071 free_netdev(dev); 1072 return err; 1073 } 1074 1075 static void free_unused_bufs(struct virtnet_info *vi) 1076 { 1077 void *buf; 1078 while (1) { 1079 buf = virtqueue_detach_unused_buf(vi->svq); 1080 if (!buf) 1081 break; 1082 dev_kfree_skb(buf); 1083 } 1084 while (1) { 1085 buf = virtqueue_detach_unused_buf(vi->rvq); 1086 if (!buf) 1087 break; 1088 if (vi->mergeable_rx_bufs || vi->big_packets) 1089 give_pages(vi, buf); 1090 else 1091 dev_kfree_skb(buf); 1092 --vi->num; 1093 } 1094 BUG_ON(vi->num != 0); 1095 } 1096 1097 static void __devexit virtnet_remove(struct virtio_device *vdev) 1098 { 1099 struct virtnet_info *vi = vdev->priv; 1100 1101 /* Stop all the virtqueues. */ 1102 vdev->config->reset(vdev); 1103 1104 1105 unregister_netdev(vi->dev); 1106 cancel_delayed_work_sync(&vi->refill); 1107 1108 /* Free unused buffers in both send and recv, if any. */ 1109 free_unused_bufs(vi); 1110 1111 vdev->config->del_vqs(vi->vdev); 1112 1113 while (vi->pages) 1114 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1115 1116 free_percpu(vi->stats); 1117 free_netdev(vi->dev); 1118 } 1119 1120 static struct virtio_device_id id_table[] = { 1121 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1122 { 0 }, 1123 }; 1124 1125 static unsigned int features[] = { 1126 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1127 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1128 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1129 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1130 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1131 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1132 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1133 }; 1134 1135 static struct virtio_driver virtio_net_driver = { 1136 .feature_table = features, 1137 .feature_table_size = ARRAY_SIZE(features), 1138 .driver.name = KBUILD_MODNAME, 1139 .driver.owner = THIS_MODULE, 1140 .id_table = id_table, 1141 .probe = virtnet_probe, 1142 .remove = __devexit_p(virtnet_remove), 1143 .config_changed = virtnet_config_changed, 1144 }; 1145 1146 static int __init init(void) 1147 { 1148 return register_virtio_driver(&virtio_net_driver); 1149 } 1150 1151 static void __exit fini(void) 1152 { 1153 unregister_virtio_driver(&virtio_net_driver); 1154 } 1155 module_init(init); 1156 module_exit(fini); 1157 1158 MODULE_DEVICE_TABLE(virtio, id_table); 1159 MODULE_DESCRIPTION("Virtio network driver"); 1160 MODULE_LICENSE("GPL"); 1161