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 size = min((unsigned)PAGE_SIZE - offset, *len); 147 int i = skb_shinfo(skb)->nr_frags; 148 149 __skb_fill_page_desc(skb, i, page, offset, size); 150 151 skb->data_len += size; 152 skb->len += size; 153 skb->truesize += PAGE_SIZE; 154 skb_shinfo(skb)->nr_frags++; 155 *len -= size; 156 } 157 158 static struct sk_buff *page_to_skb(struct virtnet_info *vi, 159 struct page *page, unsigned int len) 160 { 161 struct sk_buff *skb; 162 struct skb_vnet_hdr *hdr; 163 unsigned int copy, hdr_len, offset; 164 char *p; 165 166 p = page_address(page); 167 168 /* copy small packet so we can reuse these pages for small data */ 169 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 170 if (unlikely(!skb)) 171 return NULL; 172 173 hdr = skb_vnet_hdr(skb); 174 175 if (vi->mergeable_rx_bufs) { 176 hdr_len = sizeof hdr->mhdr; 177 offset = hdr_len; 178 } else { 179 hdr_len = sizeof hdr->hdr; 180 offset = sizeof(struct padded_vnet_hdr); 181 } 182 183 memcpy(hdr, p, hdr_len); 184 185 len -= hdr_len; 186 p += offset; 187 188 copy = len; 189 if (copy > skb_tailroom(skb)) 190 copy = skb_tailroom(skb); 191 memcpy(skb_put(skb, copy), p, copy); 192 193 len -= copy; 194 offset += copy; 195 196 /* 197 * Verify that we can indeed put this data into a skb. 198 * This is here to handle cases when the device erroneously 199 * tries to receive more than is possible. This is usually 200 * the case of a broken device. 201 */ 202 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 203 if (net_ratelimit()) 204 pr_debug("%s: too much data\n", skb->dev->name); 205 dev_kfree_skb(skb); 206 return NULL; 207 } 208 209 while (len) { 210 set_skb_frag(skb, page, offset, &len); 211 page = (struct page *)page->private; 212 offset = 0; 213 } 214 215 if (page) 216 give_pages(vi, page); 217 218 return skb; 219 } 220 221 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) 222 { 223 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 224 struct page *page; 225 int num_buf, i, len; 226 227 num_buf = hdr->mhdr.num_buffers; 228 while (--num_buf) { 229 i = skb_shinfo(skb)->nr_frags; 230 if (i >= MAX_SKB_FRAGS) { 231 pr_debug("%s: packet too long\n", skb->dev->name); 232 skb->dev->stats.rx_length_errors++; 233 return -EINVAL; 234 } 235 page = virtqueue_get_buf(vi->rvq, &len); 236 if (!page) { 237 pr_debug("%s: rx error: %d buffers missing\n", 238 skb->dev->name, hdr->mhdr.num_buffers); 239 skb->dev->stats.rx_length_errors++; 240 return -EINVAL; 241 } 242 243 if (len > PAGE_SIZE) 244 len = PAGE_SIZE; 245 246 set_skb_frag(skb, page, 0, &len); 247 248 --vi->num; 249 } 250 return 0; 251 } 252 253 static void receive_buf(struct net_device *dev, void *buf, unsigned int len) 254 { 255 struct virtnet_info *vi = netdev_priv(dev); 256 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 257 struct sk_buff *skb; 258 struct page *page; 259 struct skb_vnet_hdr *hdr; 260 261 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 262 pr_debug("%s: short packet %i\n", dev->name, len); 263 dev->stats.rx_length_errors++; 264 if (vi->mergeable_rx_bufs || vi->big_packets) 265 give_pages(vi, buf); 266 else 267 dev_kfree_skb(buf); 268 return; 269 } 270 271 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 272 skb = buf; 273 len -= sizeof(struct virtio_net_hdr); 274 skb_trim(skb, len); 275 } else { 276 page = buf; 277 skb = page_to_skb(vi, page, len); 278 if (unlikely(!skb)) { 279 dev->stats.rx_dropped++; 280 give_pages(vi, page); 281 return; 282 } 283 if (vi->mergeable_rx_bufs) 284 if (receive_mergeable(vi, skb)) { 285 dev_kfree_skb(skb); 286 return; 287 } 288 } 289 290 hdr = skb_vnet_hdr(skb); 291 292 u64_stats_update_begin(&stats->syncp); 293 stats->rx_bytes += skb->len; 294 stats->rx_packets++; 295 u64_stats_update_end(&stats->syncp); 296 297 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 298 pr_debug("Needs csum!\n"); 299 if (!skb_partial_csum_set(skb, 300 hdr->hdr.csum_start, 301 hdr->hdr.csum_offset)) 302 goto frame_err; 303 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 304 skb->ip_summed = CHECKSUM_UNNECESSARY; 305 } 306 307 skb->protocol = eth_type_trans(skb, dev); 308 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 309 ntohs(skb->protocol), skb->len, skb->pkt_type); 310 311 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 312 pr_debug("GSO!\n"); 313 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 314 case VIRTIO_NET_HDR_GSO_TCPV4: 315 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 316 break; 317 case VIRTIO_NET_HDR_GSO_UDP: 318 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 319 break; 320 case VIRTIO_NET_HDR_GSO_TCPV6: 321 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 322 break; 323 default: 324 if (net_ratelimit()) 325 printk(KERN_WARNING "%s: bad gso type %u.\n", 326 dev->name, hdr->hdr.gso_type); 327 goto frame_err; 328 } 329 330 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 331 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 332 333 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 334 if (skb_shinfo(skb)->gso_size == 0) { 335 if (net_ratelimit()) 336 printk(KERN_WARNING "%s: zero gso size.\n", 337 dev->name); 338 goto frame_err; 339 } 340 341 /* Header must be checked, and gso_segs computed. */ 342 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 343 skb_shinfo(skb)->gso_segs = 0; 344 } 345 346 netif_receive_skb(skb); 347 return; 348 349 frame_err: 350 dev->stats.rx_frame_errors++; 351 dev_kfree_skb(skb); 352 } 353 354 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) 355 { 356 struct sk_buff *skb; 357 struct skb_vnet_hdr *hdr; 358 int err; 359 360 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); 361 if (unlikely(!skb)) 362 return -ENOMEM; 363 364 skb_put(skb, MAX_PACKET_LEN); 365 366 hdr = skb_vnet_hdr(skb); 367 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); 368 369 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); 370 371 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); 372 if (err < 0) 373 dev_kfree_skb(skb); 374 375 return err; 376 } 377 378 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 379 { 380 struct page *first, *list = NULL; 381 char *p; 382 int i, err, offset; 383 384 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ 385 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 386 first = get_a_page(vi, gfp); 387 if (!first) { 388 if (list) 389 give_pages(vi, list); 390 return -ENOMEM; 391 } 392 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); 393 394 /* chain new page in list head to match sg */ 395 first->private = (unsigned long)list; 396 list = first; 397 } 398 399 first = get_a_page(vi, gfp); 400 if (!first) { 401 give_pages(vi, list); 402 return -ENOMEM; 403 } 404 p = page_address(first); 405 406 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ 407 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ 408 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); 409 410 /* vi->rx_sg[1] for data packet, from offset */ 411 offset = sizeof(struct padded_vnet_hdr); 412 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); 413 414 /* chain first in list head */ 415 first->private = (unsigned long)list; 416 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, 417 first, gfp); 418 if (err < 0) 419 give_pages(vi, first); 420 421 return err; 422 } 423 424 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 425 { 426 struct page *page; 427 int err; 428 429 page = get_a_page(vi, gfp); 430 if (!page) 431 return -ENOMEM; 432 433 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); 434 435 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp); 436 if (err < 0) 437 give_pages(vi, page); 438 439 return err; 440 } 441 442 /* Returns false if we couldn't fill entirely (OOM). */ 443 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 444 { 445 int err; 446 bool oom; 447 448 do { 449 if (vi->mergeable_rx_bufs) 450 err = add_recvbuf_mergeable(vi, gfp); 451 else if (vi->big_packets) 452 err = add_recvbuf_big(vi, gfp); 453 else 454 err = add_recvbuf_small(vi, gfp); 455 456 oom = err == -ENOMEM; 457 if (err < 0) 458 break; 459 ++vi->num; 460 } while (err > 0); 461 if (unlikely(vi->num > vi->max)) 462 vi->max = vi->num; 463 virtqueue_kick(vi->rvq); 464 return !oom; 465 } 466 467 static void skb_recv_done(struct virtqueue *rvq) 468 { 469 struct virtnet_info *vi = rvq->vdev->priv; 470 /* Schedule NAPI, Suppress further interrupts if successful. */ 471 if (napi_schedule_prep(&vi->napi)) { 472 virtqueue_disable_cb(rvq); 473 __napi_schedule(&vi->napi); 474 } 475 } 476 477 static void virtnet_napi_enable(struct virtnet_info *vi) 478 { 479 napi_enable(&vi->napi); 480 481 /* If all buffers were filled by other side before we napi_enabled, we 482 * won't get another interrupt, so process any outstanding packets 483 * now. virtnet_poll wants re-enable the queue, so we disable here. 484 * We synchronize against interrupts via NAPI_STATE_SCHED */ 485 if (napi_schedule_prep(&vi->napi)) { 486 virtqueue_disable_cb(vi->rvq); 487 __napi_schedule(&vi->napi); 488 } 489 } 490 491 static void refill_work(struct work_struct *work) 492 { 493 struct virtnet_info *vi; 494 bool still_empty; 495 496 vi = container_of(work, struct virtnet_info, refill.work); 497 napi_disable(&vi->napi); 498 still_empty = !try_fill_recv(vi, GFP_KERNEL); 499 virtnet_napi_enable(vi); 500 501 /* In theory, this can happen: if we don't get any buffers in 502 * we will *never* try to fill again. */ 503 if (still_empty) 504 schedule_delayed_work(&vi->refill, HZ/2); 505 } 506 507 static int virtnet_poll(struct napi_struct *napi, int budget) 508 { 509 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 510 void *buf; 511 unsigned int len, received = 0; 512 513 again: 514 while (received < budget && 515 (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) { 516 receive_buf(vi->dev, buf, len); 517 --vi->num; 518 received++; 519 } 520 521 if (vi->num < vi->max / 2) { 522 if (!try_fill_recv(vi, GFP_ATOMIC)) 523 schedule_delayed_work(&vi->refill, 0); 524 } 525 526 /* Out of packets? */ 527 if (received < budget) { 528 napi_complete(napi); 529 if (unlikely(!virtqueue_enable_cb(vi->rvq)) && 530 napi_schedule_prep(napi)) { 531 virtqueue_disable_cb(vi->rvq); 532 __napi_schedule(napi); 533 goto again; 534 } 535 } 536 537 return received; 538 } 539 540 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) 541 { 542 struct sk_buff *skb; 543 unsigned int len, tot_sgs = 0; 544 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 545 546 while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { 547 pr_debug("Sent skb %p\n", skb); 548 549 u64_stats_update_begin(&stats->syncp); 550 stats->tx_bytes += skb->len; 551 stats->tx_packets++; 552 u64_stats_update_end(&stats->syncp); 553 554 tot_sgs += skb_vnet_hdr(skb)->num_sg; 555 dev_kfree_skb_any(skb); 556 } 557 return tot_sgs; 558 } 559 560 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 561 { 562 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 563 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 564 565 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 566 567 if (skb->ip_summed == CHECKSUM_PARTIAL) { 568 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 569 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 570 hdr->hdr.csum_offset = skb->csum_offset; 571 } else { 572 hdr->hdr.flags = 0; 573 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 574 } 575 576 if (skb_is_gso(skb)) { 577 hdr->hdr.hdr_len = skb_headlen(skb); 578 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 579 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 580 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 581 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 582 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 583 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 584 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 585 else 586 BUG(); 587 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 588 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 589 } else { 590 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 591 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 592 } 593 594 hdr->mhdr.num_buffers = 0; 595 596 /* Encode metadata header at front. */ 597 if (vi->mergeable_rx_bufs) 598 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); 599 else 600 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); 601 602 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; 603 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, 604 0, skb); 605 } 606 607 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 608 { 609 struct virtnet_info *vi = netdev_priv(dev); 610 int capacity; 611 612 /* Free up any pending old buffers before queueing new ones. */ 613 free_old_xmit_skbs(vi); 614 615 /* Try to transmit */ 616 capacity = xmit_skb(vi, skb); 617 618 /* This can happen with OOM and indirect buffers. */ 619 if (unlikely(capacity < 0)) { 620 if (net_ratelimit()) { 621 if (likely(capacity == -ENOMEM)) { 622 dev_warn(&dev->dev, 623 "TX queue failure: out of memory\n"); 624 } else { 625 dev->stats.tx_fifo_errors++; 626 dev_warn(&dev->dev, 627 "Unexpected TX queue failure: %d\n", 628 capacity); 629 } 630 } 631 dev->stats.tx_dropped++; 632 kfree_skb(skb); 633 return NETDEV_TX_OK; 634 } 635 virtqueue_kick(vi->svq); 636 637 /* Don't wait up for transmitted skbs to be freed. */ 638 skb_orphan(skb); 639 nf_reset(skb); 640 641 /* Apparently nice girls don't return TX_BUSY; stop the queue 642 * before it gets out of hand. Naturally, this wastes entries. */ 643 if (capacity < 2+MAX_SKB_FRAGS) { 644 netif_stop_queue(dev); 645 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { 646 /* More just got used, free them then recheck. */ 647 capacity += free_old_xmit_skbs(vi); 648 if (capacity >= 2+MAX_SKB_FRAGS) { 649 netif_start_queue(dev); 650 virtqueue_disable_cb(vi->svq); 651 } 652 } 653 } 654 655 return NETDEV_TX_OK; 656 } 657 658 static int virtnet_set_mac_address(struct net_device *dev, void *p) 659 { 660 struct virtnet_info *vi = netdev_priv(dev); 661 struct virtio_device *vdev = vi->vdev; 662 int ret; 663 664 ret = eth_mac_addr(dev, p); 665 if (ret) 666 return ret; 667 668 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 669 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 670 dev->dev_addr, dev->addr_len); 671 672 return 0; 673 } 674 675 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 676 struct rtnl_link_stats64 *tot) 677 { 678 struct virtnet_info *vi = netdev_priv(dev); 679 int cpu; 680 unsigned int start; 681 682 for_each_possible_cpu(cpu) { 683 struct virtnet_stats __percpu *stats 684 = per_cpu_ptr(vi->stats, cpu); 685 u64 tpackets, tbytes, rpackets, rbytes; 686 687 do { 688 start = u64_stats_fetch_begin(&stats->syncp); 689 tpackets = stats->tx_packets; 690 tbytes = stats->tx_bytes; 691 rpackets = stats->rx_packets; 692 rbytes = stats->rx_bytes; 693 } while (u64_stats_fetch_retry(&stats->syncp, start)); 694 695 tot->rx_packets += rpackets; 696 tot->tx_packets += tpackets; 697 tot->rx_bytes += rbytes; 698 tot->tx_bytes += tbytes; 699 } 700 701 tot->tx_dropped = dev->stats.tx_dropped; 702 tot->rx_dropped = dev->stats.rx_dropped; 703 tot->rx_length_errors = dev->stats.rx_length_errors; 704 tot->rx_frame_errors = dev->stats.rx_frame_errors; 705 706 return tot; 707 } 708 709 #ifdef CONFIG_NET_POLL_CONTROLLER 710 static void virtnet_netpoll(struct net_device *dev) 711 { 712 struct virtnet_info *vi = netdev_priv(dev); 713 714 napi_schedule(&vi->napi); 715 } 716 #endif 717 718 static int virtnet_open(struct net_device *dev) 719 { 720 struct virtnet_info *vi = netdev_priv(dev); 721 722 virtnet_napi_enable(vi); 723 return 0; 724 } 725 726 /* 727 * Send command via the control virtqueue and check status. Commands 728 * supported by the hypervisor, as indicated by feature bits, should 729 * never fail unless improperly formated. 730 */ 731 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 732 struct scatterlist *data, int out, int in) 733 { 734 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 735 struct virtio_net_ctrl_hdr ctrl; 736 virtio_net_ctrl_ack status = ~0; 737 unsigned int tmp; 738 int i; 739 740 /* Caller should know better */ 741 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 742 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 743 744 out++; /* Add header */ 745 in++; /* Add return status */ 746 747 ctrl.class = class; 748 ctrl.cmd = cmd; 749 750 sg_init_table(sg, out + in); 751 752 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 753 for_each_sg(data, s, out + in - 2, i) 754 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 755 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 756 757 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0); 758 759 virtqueue_kick(vi->cvq); 760 761 /* 762 * Spin for a response, the kick causes an ioport write, trapping 763 * into the hypervisor, so the request should be handled immediately. 764 */ 765 while (!virtqueue_get_buf(vi->cvq, &tmp)) 766 cpu_relax(); 767 768 return status == VIRTIO_NET_OK; 769 } 770 771 static int virtnet_close(struct net_device *dev) 772 { 773 struct virtnet_info *vi = netdev_priv(dev); 774 775 napi_disable(&vi->napi); 776 777 return 0; 778 } 779 780 static void virtnet_set_rx_mode(struct net_device *dev) 781 { 782 struct virtnet_info *vi = netdev_priv(dev); 783 struct scatterlist sg[2]; 784 u8 promisc, allmulti; 785 struct virtio_net_ctrl_mac *mac_data; 786 struct netdev_hw_addr *ha; 787 int uc_count; 788 int mc_count; 789 void *buf; 790 int i; 791 792 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 793 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 794 return; 795 796 promisc = ((dev->flags & IFF_PROMISC) != 0); 797 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 798 799 sg_init_one(sg, &promisc, sizeof(promisc)); 800 801 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 802 VIRTIO_NET_CTRL_RX_PROMISC, 803 sg, 1, 0)) 804 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 805 promisc ? "en" : "dis"); 806 807 sg_init_one(sg, &allmulti, sizeof(allmulti)); 808 809 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 810 VIRTIO_NET_CTRL_RX_ALLMULTI, 811 sg, 1, 0)) 812 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 813 allmulti ? "en" : "dis"); 814 815 uc_count = netdev_uc_count(dev); 816 mc_count = netdev_mc_count(dev); 817 /* MAC filter - use one buffer for both lists */ 818 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 819 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 820 mac_data = buf; 821 if (!buf) { 822 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 823 return; 824 } 825 826 sg_init_table(sg, 2); 827 828 /* Store the unicast list and count in the front of the buffer */ 829 mac_data->entries = uc_count; 830 i = 0; 831 netdev_for_each_uc_addr(ha, dev) 832 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 833 834 sg_set_buf(&sg[0], mac_data, 835 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 836 837 /* multicast list and count fill the end */ 838 mac_data = (void *)&mac_data->macs[uc_count][0]; 839 840 mac_data->entries = mc_count; 841 i = 0; 842 netdev_for_each_mc_addr(ha, dev) 843 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 844 845 sg_set_buf(&sg[1], mac_data, 846 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 847 848 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 849 VIRTIO_NET_CTRL_MAC_TABLE_SET, 850 sg, 2, 0)) 851 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 852 853 kfree(buf); 854 } 855 856 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 857 { 858 struct virtnet_info *vi = netdev_priv(dev); 859 struct scatterlist sg; 860 861 sg_init_one(&sg, &vid, sizeof(vid)); 862 863 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 864 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 865 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 866 } 867 868 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 869 { 870 struct virtnet_info *vi = netdev_priv(dev); 871 struct scatterlist sg; 872 873 sg_init_one(&sg, &vid, sizeof(vid)); 874 875 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 876 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 877 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 878 } 879 880 static void virtnet_get_ringparam(struct net_device *dev, 881 struct ethtool_ringparam *ring) 882 { 883 struct virtnet_info *vi = netdev_priv(dev); 884 885 ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq); 886 ring->tx_max_pending = virtqueue_get_vring_size(vi->svq); 887 ring->rx_pending = ring->rx_max_pending; 888 ring->tx_pending = ring->tx_max_pending; 889 890 } 891 892 static const struct ethtool_ops virtnet_ethtool_ops = { 893 .get_link = ethtool_op_get_link, 894 .get_ringparam = virtnet_get_ringparam, 895 }; 896 897 #define MIN_MTU 68 898 #define MAX_MTU 65535 899 900 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 901 { 902 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 903 return -EINVAL; 904 dev->mtu = new_mtu; 905 return 0; 906 } 907 908 static const struct net_device_ops virtnet_netdev = { 909 .ndo_open = virtnet_open, 910 .ndo_stop = virtnet_close, 911 .ndo_start_xmit = start_xmit, 912 .ndo_validate_addr = eth_validate_addr, 913 .ndo_set_mac_address = virtnet_set_mac_address, 914 .ndo_set_rx_mode = virtnet_set_rx_mode, 915 .ndo_change_mtu = virtnet_change_mtu, 916 .ndo_get_stats64 = virtnet_stats, 917 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 918 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 919 #ifdef CONFIG_NET_POLL_CONTROLLER 920 .ndo_poll_controller = virtnet_netpoll, 921 #endif 922 }; 923 924 static void virtnet_update_status(struct virtnet_info *vi) 925 { 926 u16 v; 927 928 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 929 return; 930 931 vi->vdev->config->get(vi->vdev, 932 offsetof(struct virtio_net_config, status), 933 &v, sizeof(v)); 934 935 /* Ignore unknown (future) status bits */ 936 v &= VIRTIO_NET_S_LINK_UP; 937 938 if (vi->status == v) 939 return; 940 941 vi->status = v; 942 943 if (vi->status & VIRTIO_NET_S_LINK_UP) { 944 netif_carrier_on(vi->dev); 945 netif_wake_queue(vi->dev); 946 } else { 947 netif_carrier_off(vi->dev); 948 netif_stop_queue(vi->dev); 949 } 950 } 951 952 static void virtnet_config_changed(struct virtio_device *vdev) 953 { 954 struct virtnet_info *vi = vdev->priv; 955 956 virtnet_update_status(vi); 957 } 958 959 static int virtnet_probe(struct virtio_device *vdev) 960 { 961 int err; 962 struct net_device *dev; 963 struct virtnet_info *vi; 964 struct virtqueue *vqs[3]; 965 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 966 const char *names[] = { "input", "output", "control" }; 967 int nvqs; 968 969 /* Allocate ourselves a network device with room for our info */ 970 dev = alloc_etherdev(sizeof(struct virtnet_info)); 971 if (!dev) 972 return -ENOMEM; 973 974 /* Set up network device as normal. */ 975 dev->priv_flags |= IFF_UNICAST_FLT; 976 dev->netdev_ops = &virtnet_netdev; 977 dev->features = NETIF_F_HIGHDMA; 978 979 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 980 SET_NETDEV_DEV(dev, &vdev->dev); 981 982 /* Do we support "hardware" checksums? */ 983 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 984 /* This opens up the world of extra features. */ 985 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 986 if (csum) 987 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 988 989 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 990 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 991 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 992 } 993 /* Individual feature bits: what can host handle? */ 994 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 995 dev->hw_features |= NETIF_F_TSO; 996 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 997 dev->hw_features |= NETIF_F_TSO6; 998 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 999 dev->hw_features |= NETIF_F_TSO_ECN; 1000 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1001 dev->hw_features |= NETIF_F_UFO; 1002 1003 if (gso) 1004 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1005 /* (!csum && gso) case will be fixed by register_netdev() */ 1006 } 1007 1008 /* Configuration may specify what MAC to use. Otherwise random. */ 1009 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 1010 vdev->config->get(vdev, 1011 offsetof(struct virtio_net_config, mac), 1012 dev->dev_addr, dev->addr_len); 1013 } else 1014 random_ether_addr(dev->dev_addr); 1015 1016 /* Set up our device-specific information */ 1017 vi = netdev_priv(dev); 1018 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 1019 vi->dev = dev; 1020 vi->vdev = vdev; 1021 vdev->priv = vi; 1022 vi->pages = NULL; 1023 vi->stats = alloc_percpu(struct virtnet_stats); 1024 err = -ENOMEM; 1025 if (vi->stats == NULL) 1026 goto free; 1027 1028 INIT_DELAYED_WORK(&vi->refill, refill_work); 1029 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); 1030 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); 1031 1032 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1033 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1034 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1035 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1036 vi->big_packets = true; 1037 1038 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1039 vi->mergeable_rx_bufs = true; 1040 1041 /* We expect two virtqueues, receive then send, 1042 * and optionally control. */ 1043 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 1044 1045 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 1046 if (err) 1047 goto free_stats; 1048 1049 vi->rvq = vqs[0]; 1050 vi->svq = vqs[1]; 1051 1052 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 1053 vi->cvq = vqs[2]; 1054 1055 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1056 dev->features |= NETIF_F_HW_VLAN_FILTER; 1057 } 1058 1059 err = register_netdev(dev); 1060 if (err) { 1061 pr_debug("virtio_net: registering device failed\n"); 1062 goto free_vqs; 1063 } 1064 1065 /* Last of all, set up some receive buffers. */ 1066 try_fill_recv(vi, GFP_KERNEL); 1067 1068 /* If we didn't even get one input buffer, we're useless. */ 1069 if (vi->num == 0) { 1070 err = -ENOMEM; 1071 goto unregister; 1072 } 1073 1074 /* Assume link up if device can't report link status, 1075 otherwise get link status from config. */ 1076 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1077 netif_carrier_off(dev); 1078 virtnet_update_status(vi); 1079 } else { 1080 vi->status = VIRTIO_NET_S_LINK_UP; 1081 netif_carrier_on(dev); 1082 } 1083 1084 pr_debug("virtnet: registered device %s\n", dev->name); 1085 return 0; 1086 1087 unregister: 1088 unregister_netdev(dev); 1089 cancel_delayed_work_sync(&vi->refill); 1090 free_vqs: 1091 vdev->config->del_vqs(vdev); 1092 free_stats: 1093 free_percpu(vi->stats); 1094 free: 1095 free_netdev(dev); 1096 return err; 1097 } 1098 1099 static void free_unused_bufs(struct virtnet_info *vi) 1100 { 1101 void *buf; 1102 while (1) { 1103 buf = virtqueue_detach_unused_buf(vi->svq); 1104 if (!buf) 1105 break; 1106 dev_kfree_skb(buf); 1107 } 1108 while (1) { 1109 buf = virtqueue_detach_unused_buf(vi->rvq); 1110 if (!buf) 1111 break; 1112 if (vi->mergeable_rx_bufs || vi->big_packets) 1113 give_pages(vi, buf); 1114 else 1115 dev_kfree_skb(buf); 1116 --vi->num; 1117 } 1118 BUG_ON(vi->num != 0); 1119 } 1120 1121 static void __devexit virtnet_remove(struct virtio_device *vdev) 1122 { 1123 struct virtnet_info *vi = vdev->priv; 1124 1125 /* Stop all the virtqueues. */ 1126 vdev->config->reset(vdev); 1127 1128 1129 unregister_netdev(vi->dev); 1130 cancel_delayed_work_sync(&vi->refill); 1131 1132 /* Free unused buffers in both send and recv, if any. */ 1133 free_unused_bufs(vi); 1134 1135 vdev->config->del_vqs(vi->vdev); 1136 1137 while (vi->pages) 1138 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1139 1140 free_percpu(vi->stats); 1141 free_netdev(vi->dev); 1142 } 1143 1144 static struct virtio_device_id id_table[] = { 1145 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1146 { 0 }, 1147 }; 1148 1149 static unsigned int features[] = { 1150 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1151 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1152 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1153 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1154 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1155 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1156 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1157 }; 1158 1159 static struct virtio_driver virtio_net_driver = { 1160 .feature_table = features, 1161 .feature_table_size = ARRAY_SIZE(features), 1162 .driver.name = KBUILD_MODNAME, 1163 .driver.owner = THIS_MODULE, 1164 .id_table = id_table, 1165 .probe = virtnet_probe, 1166 .remove = __devexit_p(virtnet_remove), 1167 .config_changed = virtnet_config_changed, 1168 }; 1169 1170 static int __init init(void) 1171 { 1172 return register_virtio_driver(&virtio_net_driver); 1173 } 1174 1175 static void __exit fini(void) 1176 { 1177 unregister_virtio_driver(&virtio_net_driver); 1178 } 1179 module_init(init); 1180 module_exit(fini); 1181 1182 MODULE_DEVICE_TABLE(virtio, id_table); 1183 MODULE_DESCRIPTION("Virtio network driver"); 1184 MODULE_LICENSE("GPL"); 1185