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 bool csum = true, gso = true; 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 #define VIRTNET_DRIVER_VERSION "1.0.0" 43 44 struct virtnet_stats { 45 struct u64_stats_sync syncp; 46 u64 tx_bytes; 47 u64 tx_packets; 48 49 u64 rx_bytes; 50 u64 rx_packets; 51 }; 52 53 struct virtnet_info { 54 struct virtio_device *vdev; 55 struct virtqueue *rvq, *svq, *cvq; 56 struct net_device *dev; 57 struct napi_struct napi; 58 unsigned int status; 59 60 /* Number of input buffers, and max we've ever had. */ 61 unsigned int num, max; 62 63 /* I like... big packets and I cannot lie! */ 64 bool big_packets; 65 66 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 67 bool mergeable_rx_bufs; 68 69 /* Active statistics */ 70 struct virtnet_stats __percpu *stats; 71 72 /* Work struct for refilling if we run low on memory. */ 73 struct delayed_work refill; 74 75 /* Chain pages by the private ptr. */ 76 struct page *pages; 77 78 /* fragments + linear part + virtio header */ 79 struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; 80 struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; 81 }; 82 83 struct skb_vnet_hdr { 84 union { 85 struct virtio_net_hdr hdr; 86 struct virtio_net_hdr_mrg_rxbuf mhdr; 87 }; 88 unsigned int num_sg; 89 }; 90 91 struct padded_vnet_hdr { 92 struct virtio_net_hdr hdr; 93 /* 94 * virtio_net_hdr should be in a separated sg buffer because of a 95 * QEMU bug, and data sg buffer shares same page with this header sg. 96 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 97 */ 98 char padding[6]; 99 }; 100 101 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 102 { 103 return (struct skb_vnet_hdr *)skb->cb; 104 } 105 106 /* 107 * private is used to chain pages for big packets, put the whole 108 * most recent used list in the beginning for reuse 109 */ 110 static void give_pages(struct virtnet_info *vi, struct page *page) 111 { 112 struct page *end; 113 114 /* Find end of list, sew whole thing into vi->pages. */ 115 for (end = page; end->private; end = (struct page *)end->private); 116 end->private = (unsigned long)vi->pages; 117 vi->pages = page; 118 } 119 120 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 121 { 122 struct page *p = vi->pages; 123 124 if (p) { 125 vi->pages = (struct page *)p->private; 126 /* clear private here, it is used to chain pages */ 127 p->private = 0; 128 } else 129 p = alloc_page(gfp_mask); 130 return p; 131 } 132 133 static void skb_xmit_done(struct virtqueue *svq) 134 { 135 struct virtnet_info *vi = svq->vdev->priv; 136 137 /* Suppress further interrupts. */ 138 virtqueue_disable_cb(svq); 139 140 /* We were probably waiting for more output buffers. */ 141 netif_wake_queue(vi->dev); 142 } 143 144 static void set_skb_frag(struct sk_buff *skb, struct page *page, 145 unsigned int offset, unsigned int *len) 146 { 147 int size = min((unsigned)PAGE_SIZE - offset, *len); 148 int i = skb_shinfo(skb)->nr_frags; 149 150 __skb_fill_page_desc(skb, i, page, offset, size); 151 152 skb->data_len += size; 153 skb->len += size; 154 skb->truesize += PAGE_SIZE; 155 skb_shinfo(skb)->nr_frags++; 156 *len -= size; 157 } 158 159 static struct sk_buff *page_to_skb(struct virtnet_info *vi, 160 struct page *page, unsigned int len) 161 { 162 struct sk_buff *skb; 163 struct skb_vnet_hdr *hdr; 164 unsigned int copy, hdr_len, offset; 165 char *p; 166 167 p = page_address(page); 168 169 /* copy small packet so we can reuse these pages for small data */ 170 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 171 if (unlikely(!skb)) 172 return NULL; 173 174 hdr = skb_vnet_hdr(skb); 175 176 if (vi->mergeable_rx_bufs) { 177 hdr_len = sizeof hdr->mhdr; 178 offset = hdr_len; 179 } else { 180 hdr_len = sizeof hdr->hdr; 181 offset = sizeof(struct padded_vnet_hdr); 182 } 183 184 memcpy(hdr, p, hdr_len); 185 186 len -= hdr_len; 187 p += offset; 188 189 copy = len; 190 if (copy > skb_tailroom(skb)) 191 copy = skb_tailroom(skb); 192 memcpy(skb_put(skb, copy), p, copy); 193 194 len -= copy; 195 offset += copy; 196 197 /* 198 * Verify that we can indeed put this data into a skb. 199 * This is here to handle cases when the device erroneously 200 * tries to receive more than is possible. This is usually 201 * the case of a broken device. 202 */ 203 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 204 if (net_ratelimit()) 205 pr_debug("%s: too much data\n", skb->dev->name); 206 dev_kfree_skb(skb); 207 return NULL; 208 } 209 210 while (len) { 211 set_skb_frag(skb, page, offset, &len); 212 page = (struct page *)page->private; 213 offset = 0; 214 } 215 216 if (page) 217 give_pages(vi, page); 218 219 return skb; 220 } 221 222 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) 223 { 224 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 225 struct page *page; 226 int num_buf, i, len; 227 228 num_buf = hdr->mhdr.num_buffers; 229 while (--num_buf) { 230 i = skb_shinfo(skb)->nr_frags; 231 if (i >= MAX_SKB_FRAGS) { 232 pr_debug("%s: packet too long\n", skb->dev->name); 233 skb->dev->stats.rx_length_errors++; 234 return -EINVAL; 235 } 236 page = virtqueue_get_buf(vi->rvq, &len); 237 if (!page) { 238 pr_debug("%s: rx error: %d buffers missing\n", 239 skb->dev->name, hdr->mhdr.num_buffers); 240 skb->dev->stats.rx_length_errors++; 241 return -EINVAL; 242 } 243 244 if (len > PAGE_SIZE) 245 len = PAGE_SIZE; 246 247 set_skb_frag(skb, page, 0, &len); 248 249 --vi->num; 250 } 251 return 0; 252 } 253 254 static void receive_buf(struct net_device *dev, void *buf, unsigned int len) 255 { 256 struct virtnet_info *vi = netdev_priv(dev); 257 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 258 struct sk_buff *skb; 259 struct page *page; 260 struct skb_vnet_hdr *hdr; 261 262 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 263 pr_debug("%s: short packet %i\n", dev->name, len); 264 dev->stats.rx_length_errors++; 265 if (vi->mergeable_rx_bufs || vi->big_packets) 266 give_pages(vi, buf); 267 else 268 dev_kfree_skb(buf); 269 return; 270 } 271 272 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 273 skb = buf; 274 len -= sizeof(struct virtio_net_hdr); 275 skb_trim(skb, len); 276 } else { 277 page = buf; 278 skb = page_to_skb(vi, page, len); 279 if (unlikely(!skb)) { 280 dev->stats.rx_dropped++; 281 give_pages(vi, page); 282 return; 283 } 284 if (vi->mergeable_rx_bufs) 285 if (receive_mergeable(vi, skb)) { 286 dev_kfree_skb(skb); 287 return; 288 } 289 } 290 291 hdr = skb_vnet_hdr(skb); 292 293 u64_stats_update_begin(&stats->syncp); 294 stats->rx_bytes += skb->len; 295 stats->rx_packets++; 296 u64_stats_update_end(&stats->syncp); 297 298 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 299 pr_debug("Needs csum!\n"); 300 if (!skb_partial_csum_set(skb, 301 hdr->hdr.csum_start, 302 hdr->hdr.csum_offset)) 303 goto frame_err; 304 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 305 skb->ip_summed = CHECKSUM_UNNECESSARY; 306 } 307 308 skb->protocol = eth_type_trans(skb, dev); 309 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 310 ntohs(skb->protocol), skb->len, skb->pkt_type); 311 312 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 313 pr_debug("GSO!\n"); 314 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 315 case VIRTIO_NET_HDR_GSO_TCPV4: 316 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 317 break; 318 case VIRTIO_NET_HDR_GSO_UDP: 319 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 320 break; 321 case VIRTIO_NET_HDR_GSO_TCPV6: 322 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 323 break; 324 default: 325 if (net_ratelimit()) 326 printk(KERN_WARNING "%s: bad gso type %u.\n", 327 dev->name, hdr->hdr.gso_type); 328 goto frame_err; 329 } 330 331 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 332 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 333 334 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 335 if (skb_shinfo(skb)->gso_size == 0) { 336 if (net_ratelimit()) 337 printk(KERN_WARNING "%s: zero gso size.\n", 338 dev->name); 339 goto frame_err; 340 } 341 342 /* Header must be checked, and gso_segs computed. */ 343 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 344 skb_shinfo(skb)->gso_segs = 0; 345 } 346 347 netif_receive_skb(skb); 348 return; 349 350 frame_err: 351 dev->stats.rx_frame_errors++; 352 dev_kfree_skb(skb); 353 } 354 355 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) 356 { 357 struct sk_buff *skb; 358 struct skb_vnet_hdr *hdr; 359 int err; 360 361 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); 362 if (unlikely(!skb)) 363 return -ENOMEM; 364 365 skb_put(skb, MAX_PACKET_LEN); 366 367 hdr = skb_vnet_hdr(skb); 368 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); 369 370 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); 371 372 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); 373 if (err < 0) 374 dev_kfree_skb(skb); 375 376 return err; 377 } 378 379 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 380 { 381 struct page *first, *list = NULL; 382 char *p; 383 int i, err, offset; 384 385 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ 386 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 387 first = get_a_page(vi, gfp); 388 if (!first) { 389 if (list) 390 give_pages(vi, list); 391 return -ENOMEM; 392 } 393 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); 394 395 /* chain new page in list head to match sg */ 396 first->private = (unsigned long)list; 397 list = first; 398 } 399 400 first = get_a_page(vi, gfp); 401 if (!first) { 402 give_pages(vi, list); 403 return -ENOMEM; 404 } 405 p = page_address(first); 406 407 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ 408 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ 409 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); 410 411 /* vi->rx_sg[1] for data packet, from offset */ 412 offset = sizeof(struct padded_vnet_hdr); 413 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); 414 415 /* chain first in list head */ 416 first->private = (unsigned long)list; 417 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, 418 first, gfp); 419 if (err < 0) 420 give_pages(vi, first); 421 422 return err; 423 } 424 425 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 426 { 427 struct page *page; 428 int err; 429 430 page = get_a_page(vi, gfp); 431 if (!page) 432 return -ENOMEM; 433 434 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); 435 436 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp); 437 if (err < 0) 438 give_pages(vi, page); 439 440 return err; 441 } 442 443 /* Returns false if we couldn't fill entirely (OOM). */ 444 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 445 { 446 int err; 447 bool oom; 448 449 do { 450 if (vi->mergeable_rx_bufs) 451 err = add_recvbuf_mergeable(vi, gfp); 452 else if (vi->big_packets) 453 err = add_recvbuf_big(vi, gfp); 454 else 455 err = add_recvbuf_small(vi, gfp); 456 457 oom = err == -ENOMEM; 458 if (err < 0) 459 break; 460 ++vi->num; 461 } while (err > 0); 462 if (unlikely(vi->num > vi->max)) 463 vi->max = vi->num; 464 virtqueue_kick(vi->rvq); 465 return !oom; 466 } 467 468 static void skb_recv_done(struct virtqueue *rvq) 469 { 470 struct virtnet_info *vi = rvq->vdev->priv; 471 /* Schedule NAPI, Suppress further interrupts if successful. */ 472 if (napi_schedule_prep(&vi->napi)) { 473 virtqueue_disable_cb(rvq); 474 __napi_schedule(&vi->napi); 475 } 476 } 477 478 static void virtnet_napi_enable(struct virtnet_info *vi) 479 { 480 napi_enable(&vi->napi); 481 482 /* If all buffers were filled by other side before we napi_enabled, we 483 * won't get another interrupt, so process any outstanding packets 484 * now. virtnet_poll wants re-enable the queue, so we disable here. 485 * We synchronize against interrupts via NAPI_STATE_SCHED */ 486 if (napi_schedule_prep(&vi->napi)) { 487 virtqueue_disable_cb(vi->rvq); 488 __napi_schedule(&vi->napi); 489 } 490 } 491 492 static void refill_work(struct work_struct *work) 493 { 494 struct virtnet_info *vi; 495 bool still_empty; 496 497 vi = container_of(work, struct virtnet_info, refill.work); 498 napi_disable(&vi->napi); 499 still_empty = !try_fill_recv(vi, GFP_KERNEL); 500 virtnet_napi_enable(vi); 501 502 /* In theory, this can happen: if we don't get any buffers in 503 * we will *never* try to fill again. */ 504 if (still_empty) 505 schedule_delayed_work(&vi->refill, HZ/2); 506 } 507 508 static int virtnet_poll(struct napi_struct *napi, int budget) 509 { 510 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 511 void *buf; 512 unsigned int len, received = 0; 513 514 again: 515 while (received < budget && 516 (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) { 517 receive_buf(vi->dev, buf, len); 518 --vi->num; 519 received++; 520 } 521 522 if (vi->num < vi->max / 2) { 523 if (!try_fill_recv(vi, GFP_ATOMIC)) 524 schedule_delayed_work(&vi->refill, 0); 525 } 526 527 /* Out of packets? */ 528 if (received < budget) { 529 napi_complete(napi); 530 if (unlikely(!virtqueue_enable_cb(vi->rvq)) && 531 napi_schedule_prep(napi)) { 532 virtqueue_disable_cb(vi->rvq); 533 __napi_schedule(napi); 534 goto again; 535 } 536 } 537 538 return received; 539 } 540 541 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) 542 { 543 struct sk_buff *skb; 544 unsigned int len, tot_sgs = 0; 545 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 546 547 while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { 548 pr_debug("Sent skb %p\n", skb); 549 550 u64_stats_update_begin(&stats->syncp); 551 stats->tx_bytes += skb->len; 552 stats->tx_packets++; 553 u64_stats_update_end(&stats->syncp); 554 555 tot_sgs += skb_vnet_hdr(skb)->num_sg; 556 dev_kfree_skb_any(skb); 557 } 558 return tot_sgs; 559 } 560 561 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 562 { 563 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 564 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 565 566 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 567 568 if (skb->ip_summed == CHECKSUM_PARTIAL) { 569 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 570 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 571 hdr->hdr.csum_offset = skb->csum_offset; 572 } else { 573 hdr->hdr.flags = 0; 574 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 575 } 576 577 if (skb_is_gso(skb)) { 578 hdr->hdr.hdr_len = skb_headlen(skb); 579 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 580 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 581 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 582 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 583 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 584 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 585 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 586 else 587 BUG(); 588 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 589 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 590 } else { 591 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 592 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 593 } 594 595 hdr->mhdr.num_buffers = 0; 596 597 /* Encode metadata header at front. */ 598 if (vi->mergeable_rx_bufs) 599 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); 600 else 601 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); 602 603 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; 604 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, 605 0, skb); 606 } 607 608 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 609 { 610 struct virtnet_info *vi = netdev_priv(dev); 611 int capacity; 612 613 /* Free up any pending old buffers before queueing new ones. */ 614 free_old_xmit_skbs(vi); 615 616 /* Try to transmit */ 617 capacity = xmit_skb(vi, skb); 618 619 /* This can happen with OOM and indirect buffers. */ 620 if (unlikely(capacity < 0)) { 621 if (net_ratelimit()) { 622 if (likely(capacity == -ENOMEM)) { 623 dev_warn(&dev->dev, 624 "TX queue failure: out of memory\n"); 625 } else { 626 dev->stats.tx_fifo_errors++; 627 dev_warn(&dev->dev, 628 "Unexpected TX queue failure: %d\n", 629 capacity); 630 } 631 } 632 dev->stats.tx_dropped++; 633 kfree_skb(skb); 634 return NETDEV_TX_OK; 635 } 636 virtqueue_kick(vi->svq); 637 638 /* Don't wait up for transmitted skbs to be freed. */ 639 skb_orphan(skb); 640 nf_reset(skb); 641 642 /* Apparently nice girls don't return TX_BUSY; stop the queue 643 * before it gets out of hand. Naturally, this wastes entries. */ 644 if (capacity < 2+MAX_SKB_FRAGS) { 645 netif_stop_queue(dev); 646 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { 647 /* More just got used, free them then recheck. */ 648 capacity += free_old_xmit_skbs(vi); 649 if (capacity >= 2+MAX_SKB_FRAGS) { 650 netif_start_queue(dev); 651 virtqueue_disable_cb(vi->svq); 652 } 653 } 654 } 655 656 return NETDEV_TX_OK; 657 } 658 659 static int virtnet_set_mac_address(struct net_device *dev, void *p) 660 { 661 struct virtnet_info *vi = netdev_priv(dev); 662 struct virtio_device *vdev = vi->vdev; 663 int ret; 664 665 ret = eth_mac_addr(dev, p); 666 if (ret) 667 return ret; 668 669 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 670 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 671 dev->dev_addr, dev->addr_len); 672 673 return 0; 674 } 675 676 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 677 struct rtnl_link_stats64 *tot) 678 { 679 struct virtnet_info *vi = netdev_priv(dev); 680 int cpu; 681 unsigned int start; 682 683 for_each_possible_cpu(cpu) { 684 struct virtnet_stats __percpu *stats 685 = per_cpu_ptr(vi->stats, cpu); 686 u64 tpackets, tbytes, rpackets, rbytes; 687 688 do { 689 start = u64_stats_fetch_begin(&stats->syncp); 690 tpackets = stats->tx_packets; 691 tbytes = stats->tx_bytes; 692 rpackets = stats->rx_packets; 693 rbytes = stats->rx_bytes; 694 } while (u64_stats_fetch_retry(&stats->syncp, start)); 695 696 tot->rx_packets += rpackets; 697 tot->tx_packets += tpackets; 698 tot->rx_bytes += rbytes; 699 tot->tx_bytes += tbytes; 700 } 701 702 tot->tx_dropped = dev->stats.tx_dropped; 703 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 704 tot->rx_dropped = dev->stats.rx_dropped; 705 tot->rx_length_errors = dev->stats.rx_length_errors; 706 tot->rx_frame_errors = dev->stats.rx_frame_errors; 707 708 return tot; 709 } 710 711 #ifdef CONFIG_NET_POLL_CONTROLLER 712 static void virtnet_netpoll(struct net_device *dev) 713 { 714 struct virtnet_info *vi = netdev_priv(dev); 715 716 napi_schedule(&vi->napi); 717 } 718 #endif 719 720 static int virtnet_open(struct net_device *dev) 721 { 722 struct virtnet_info *vi = netdev_priv(dev); 723 724 virtnet_napi_enable(vi); 725 return 0; 726 } 727 728 /* 729 * Send command via the control virtqueue and check status. Commands 730 * supported by the hypervisor, as indicated by feature bits, should 731 * never fail unless improperly formated. 732 */ 733 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 734 struct scatterlist *data, int out, int in) 735 { 736 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 737 struct virtio_net_ctrl_hdr ctrl; 738 virtio_net_ctrl_ack status = ~0; 739 unsigned int tmp; 740 int i; 741 742 /* Caller should know better */ 743 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 744 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 745 746 out++; /* Add header */ 747 in++; /* Add return status */ 748 749 ctrl.class = class; 750 ctrl.cmd = cmd; 751 752 sg_init_table(sg, out + in); 753 754 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 755 for_each_sg(data, s, out + in - 2, i) 756 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 757 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 758 759 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0); 760 761 virtqueue_kick(vi->cvq); 762 763 /* 764 * Spin for a response, the kick causes an ioport write, trapping 765 * into the hypervisor, so the request should be handled immediately. 766 */ 767 while (!virtqueue_get_buf(vi->cvq, &tmp)) 768 cpu_relax(); 769 770 return status == VIRTIO_NET_OK; 771 } 772 773 static int virtnet_close(struct net_device *dev) 774 { 775 struct virtnet_info *vi = netdev_priv(dev); 776 777 napi_disable(&vi->napi); 778 779 return 0; 780 } 781 782 static void virtnet_set_rx_mode(struct net_device *dev) 783 { 784 struct virtnet_info *vi = netdev_priv(dev); 785 struct scatterlist sg[2]; 786 u8 promisc, allmulti; 787 struct virtio_net_ctrl_mac *mac_data; 788 struct netdev_hw_addr *ha; 789 int uc_count; 790 int mc_count; 791 void *buf; 792 int i; 793 794 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 795 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 796 return; 797 798 promisc = ((dev->flags & IFF_PROMISC) != 0); 799 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 800 801 sg_init_one(sg, &promisc, sizeof(promisc)); 802 803 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 804 VIRTIO_NET_CTRL_RX_PROMISC, 805 sg, 1, 0)) 806 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 807 promisc ? "en" : "dis"); 808 809 sg_init_one(sg, &allmulti, sizeof(allmulti)); 810 811 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 812 VIRTIO_NET_CTRL_RX_ALLMULTI, 813 sg, 1, 0)) 814 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 815 allmulti ? "en" : "dis"); 816 817 uc_count = netdev_uc_count(dev); 818 mc_count = netdev_mc_count(dev); 819 /* MAC filter - use one buffer for both lists */ 820 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 821 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 822 mac_data = buf; 823 if (!buf) { 824 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 825 return; 826 } 827 828 sg_init_table(sg, 2); 829 830 /* Store the unicast list and count in the front of the buffer */ 831 mac_data->entries = uc_count; 832 i = 0; 833 netdev_for_each_uc_addr(ha, dev) 834 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 835 836 sg_set_buf(&sg[0], mac_data, 837 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 838 839 /* multicast list and count fill the end */ 840 mac_data = (void *)&mac_data->macs[uc_count][0]; 841 842 mac_data->entries = mc_count; 843 i = 0; 844 netdev_for_each_mc_addr(ha, dev) 845 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 846 847 sg_set_buf(&sg[1], mac_data, 848 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 849 850 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 851 VIRTIO_NET_CTRL_MAC_TABLE_SET, 852 sg, 2, 0)) 853 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 854 855 kfree(buf); 856 } 857 858 static int virtnet_vlan_rx_add_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_ADD, &sg, 1, 0)) 867 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 868 return 0; 869 } 870 871 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 872 { 873 struct virtnet_info *vi = netdev_priv(dev); 874 struct scatterlist sg; 875 876 sg_init_one(&sg, &vid, sizeof(vid)); 877 878 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 879 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 880 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 881 return 0; 882 } 883 884 static void virtnet_get_ringparam(struct net_device *dev, 885 struct ethtool_ringparam *ring) 886 { 887 struct virtnet_info *vi = netdev_priv(dev); 888 889 ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq); 890 ring->tx_max_pending = virtqueue_get_vring_size(vi->svq); 891 ring->rx_pending = ring->rx_max_pending; 892 ring->tx_pending = ring->tx_max_pending; 893 894 } 895 896 897 static void virtnet_get_drvinfo(struct net_device *dev, 898 struct ethtool_drvinfo *info) 899 { 900 struct virtnet_info *vi = netdev_priv(dev); 901 struct virtio_device *vdev = vi->vdev; 902 903 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 904 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 905 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 906 907 } 908 909 static const struct ethtool_ops virtnet_ethtool_ops = { 910 .get_drvinfo = virtnet_get_drvinfo, 911 .get_link = ethtool_op_get_link, 912 .get_ringparam = virtnet_get_ringparam, 913 }; 914 915 #define MIN_MTU 68 916 #define MAX_MTU 65535 917 918 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 919 { 920 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 921 return -EINVAL; 922 dev->mtu = new_mtu; 923 return 0; 924 } 925 926 static const struct net_device_ops virtnet_netdev = { 927 .ndo_open = virtnet_open, 928 .ndo_stop = virtnet_close, 929 .ndo_start_xmit = start_xmit, 930 .ndo_validate_addr = eth_validate_addr, 931 .ndo_set_mac_address = virtnet_set_mac_address, 932 .ndo_set_rx_mode = virtnet_set_rx_mode, 933 .ndo_change_mtu = virtnet_change_mtu, 934 .ndo_get_stats64 = virtnet_stats, 935 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 936 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 937 #ifdef CONFIG_NET_POLL_CONTROLLER 938 .ndo_poll_controller = virtnet_netpoll, 939 #endif 940 }; 941 942 static void virtnet_update_status(struct virtnet_info *vi) 943 { 944 u16 v; 945 946 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS, 947 offsetof(struct virtio_net_config, status), 948 &v) < 0) 949 return; 950 951 /* Ignore unknown (future) status bits */ 952 v &= VIRTIO_NET_S_LINK_UP; 953 954 if (vi->status == v) 955 return; 956 957 vi->status = v; 958 959 if (vi->status & VIRTIO_NET_S_LINK_UP) { 960 netif_carrier_on(vi->dev); 961 netif_wake_queue(vi->dev); 962 } else { 963 netif_carrier_off(vi->dev); 964 netif_stop_queue(vi->dev); 965 } 966 } 967 968 static void virtnet_config_changed(struct virtio_device *vdev) 969 { 970 struct virtnet_info *vi = vdev->priv; 971 972 virtnet_update_status(vi); 973 } 974 975 static int virtnet_probe(struct virtio_device *vdev) 976 { 977 int err; 978 struct net_device *dev; 979 struct virtnet_info *vi; 980 struct virtqueue *vqs[3]; 981 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 982 const char *names[] = { "input", "output", "control" }; 983 int nvqs; 984 985 /* Allocate ourselves a network device with room for our info */ 986 dev = alloc_etherdev(sizeof(struct virtnet_info)); 987 if (!dev) 988 return -ENOMEM; 989 990 /* Set up network device as normal. */ 991 dev->priv_flags |= IFF_UNICAST_FLT; 992 dev->netdev_ops = &virtnet_netdev; 993 dev->features = NETIF_F_HIGHDMA; 994 995 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 996 SET_NETDEV_DEV(dev, &vdev->dev); 997 998 /* Do we support "hardware" checksums? */ 999 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 1000 /* This opens up the world of extra features. */ 1001 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1002 if (csum) 1003 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1004 1005 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 1006 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 1007 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 1008 } 1009 /* Individual feature bits: what can host handle? */ 1010 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 1011 dev->hw_features |= NETIF_F_TSO; 1012 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 1013 dev->hw_features |= NETIF_F_TSO6; 1014 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 1015 dev->hw_features |= NETIF_F_TSO_ECN; 1016 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1017 dev->hw_features |= NETIF_F_UFO; 1018 1019 if (gso) 1020 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1021 /* (!csum && gso) case will be fixed by register_netdev() */ 1022 } 1023 1024 /* Configuration may specify what MAC to use. Otherwise random. */ 1025 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC, 1026 offsetof(struct virtio_net_config, mac), 1027 dev->dev_addr, dev->addr_len) < 0) 1028 random_ether_addr(dev->dev_addr); 1029 1030 /* Set up our device-specific information */ 1031 vi = netdev_priv(dev); 1032 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 1033 vi->dev = dev; 1034 vi->vdev = vdev; 1035 vdev->priv = vi; 1036 vi->pages = NULL; 1037 vi->stats = alloc_percpu(struct virtnet_stats); 1038 err = -ENOMEM; 1039 if (vi->stats == NULL) 1040 goto free; 1041 1042 INIT_DELAYED_WORK(&vi->refill, refill_work); 1043 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); 1044 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); 1045 1046 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1047 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1048 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1049 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1050 vi->big_packets = true; 1051 1052 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1053 vi->mergeable_rx_bufs = true; 1054 1055 /* We expect two virtqueues, receive then send, 1056 * and optionally control. */ 1057 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 1058 1059 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 1060 if (err) 1061 goto free_stats; 1062 1063 vi->rvq = vqs[0]; 1064 vi->svq = vqs[1]; 1065 1066 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 1067 vi->cvq = vqs[2]; 1068 1069 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1070 dev->features |= NETIF_F_HW_VLAN_FILTER; 1071 } 1072 1073 err = register_netdev(dev); 1074 if (err) { 1075 pr_debug("virtio_net: registering device failed\n"); 1076 goto free_vqs; 1077 } 1078 1079 /* Last of all, set up some receive buffers. */ 1080 try_fill_recv(vi, GFP_KERNEL); 1081 1082 /* If we didn't even get one input buffer, we're useless. */ 1083 if (vi->num == 0) { 1084 err = -ENOMEM; 1085 goto unregister; 1086 } 1087 1088 /* Assume link up if device can't report link status, 1089 otherwise get link status from config. */ 1090 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1091 netif_carrier_off(dev); 1092 virtnet_update_status(vi); 1093 } else { 1094 vi->status = VIRTIO_NET_S_LINK_UP; 1095 netif_carrier_on(dev); 1096 } 1097 1098 pr_debug("virtnet: registered device %s\n", dev->name); 1099 return 0; 1100 1101 unregister: 1102 unregister_netdev(dev); 1103 cancel_delayed_work_sync(&vi->refill); 1104 free_vqs: 1105 vdev->config->del_vqs(vdev); 1106 free_stats: 1107 free_percpu(vi->stats); 1108 free: 1109 free_netdev(dev); 1110 return err; 1111 } 1112 1113 static void free_unused_bufs(struct virtnet_info *vi) 1114 { 1115 void *buf; 1116 while (1) { 1117 buf = virtqueue_detach_unused_buf(vi->svq); 1118 if (!buf) 1119 break; 1120 dev_kfree_skb(buf); 1121 } 1122 while (1) { 1123 buf = virtqueue_detach_unused_buf(vi->rvq); 1124 if (!buf) 1125 break; 1126 if (vi->mergeable_rx_bufs || vi->big_packets) 1127 give_pages(vi, buf); 1128 else 1129 dev_kfree_skb(buf); 1130 --vi->num; 1131 } 1132 BUG_ON(vi->num != 0); 1133 } 1134 1135 static void __devexit virtnet_remove(struct virtio_device *vdev) 1136 { 1137 struct virtnet_info *vi = vdev->priv; 1138 1139 /* Stop all the virtqueues. */ 1140 vdev->config->reset(vdev); 1141 1142 1143 unregister_netdev(vi->dev); 1144 cancel_delayed_work_sync(&vi->refill); 1145 1146 /* Free unused buffers in both send and recv, if any. */ 1147 free_unused_bufs(vi); 1148 1149 vdev->config->del_vqs(vi->vdev); 1150 1151 while (vi->pages) 1152 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1153 1154 free_percpu(vi->stats); 1155 free_netdev(vi->dev); 1156 } 1157 1158 static struct virtio_device_id id_table[] = { 1159 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1160 { 0 }, 1161 }; 1162 1163 static unsigned int features[] = { 1164 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1165 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1166 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1167 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1168 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1169 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1170 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1171 }; 1172 1173 static struct virtio_driver virtio_net_driver = { 1174 .feature_table = features, 1175 .feature_table_size = ARRAY_SIZE(features), 1176 .driver.name = KBUILD_MODNAME, 1177 .driver.owner = THIS_MODULE, 1178 .id_table = id_table, 1179 .probe = virtnet_probe, 1180 .remove = __devexit_p(virtnet_remove), 1181 .config_changed = virtnet_config_changed, 1182 }; 1183 1184 static int __init init(void) 1185 { 1186 return register_virtio_driver(&virtio_net_driver); 1187 } 1188 1189 static void __exit fini(void) 1190 { 1191 unregister_virtio_driver(&virtio_net_driver); 1192 } 1193 module_init(init); 1194 module_exit(fini); 1195 1196 MODULE_DEVICE_TABLE(virtio, id_table); 1197 MODULE_DESCRIPTION("Virtio network driver"); 1198 MODULE_LICENSE("GPL"); 1199