1 /* A simple 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 29 static int napi_weight = 128; 30 module_param(napi_weight, int, 0444); 31 32 static int csum = 1, gso = 1; 33 module_param(csum, bool, 0444); 34 module_param(gso, bool, 0444); 35 36 /* FIXME: MTU in config. */ 37 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 38 #define GOOD_COPY_LEN 128 39 40 #define VIRTNET_SEND_COMMAND_SG_MAX 2 41 42 struct virtnet_info 43 { 44 struct virtio_device *vdev; 45 struct virtqueue *rvq, *svq, *cvq; 46 struct net_device *dev; 47 struct napi_struct napi; 48 unsigned int status; 49 50 /* The skb we couldn't send because buffers were full. */ 51 struct sk_buff *last_xmit_skb; 52 53 /* If we need to free in a timer, this is it. */ 54 struct timer_list xmit_free_timer; 55 56 /* Number of input buffers, and max we've ever had. */ 57 unsigned int num, max; 58 59 /* For cleaning up after transmission. */ 60 struct tasklet_struct tasklet; 61 bool free_in_tasklet; 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 /* Receive & send queues. */ 70 struct sk_buff_head recv; 71 struct sk_buff_head send; 72 73 /* Work struct for refilling if we run low on memory. */ 74 struct delayed_work refill; 75 76 /* Chain pages by the private ptr. */ 77 struct page *pages; 78 }; 79 80 static inline void *skb_vnet_hdr(struct sk_buff *skb) 81 { 82 return (struct virtio_net_hdr *)skb->cb; 83 } 84 85 static void give_a_page(struct virtnet_info *vi, struct page *page) 86 { 87 page->private = (unsigned long)vi->pages; 88 vi->pages = page; 89 } 90 91 static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb) 92 { 93 unsigned int i; 94 95 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) 96 give_a_page(vi, skb_shinfo(skb)->frags[i].page); 97 skb_shinfo(skb)->nr_frags = 0; 98 skb->data_len = 0; 99 } 100 101 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 102 { 103 struct page *p = vi->pages; 104 105 if (p) 106 vi->pages = (struct page *)p->private; 107 else 108 p = alloc_page(gfp_mask); 109 return p; 110 } 111 112 static void skb_xmit_done(struct virtqueue *svq) 113 { 114 struct virtnet_info *vi = svq->vdev->priv; 115 116 /* Suppress further interrupts. */ 117 svq->vq_ops->disable_cb(svq); 118 119 /* We were probably waiting for more output buffers. */ 120 netif_wake_queue(vi->dev); 121 122 /* Make sure we re-xmit last_xmit_skb: if there are no more packets 123 * queued, start_xmit won't be called. */ 124 tasklet_schedule(&vi->tasklet); 125 } 126 127 static void receive_skb(struct net_device *dev, struct sk_buff *skb, 128 unsigned len) 129 { 130 struct virtnet_info *vi = netdev_priv(dev); 131 struct virtio_net_hdr *hdr = skb_vnet_hdr(skb); 132 int err; 133 int i; 134 135 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 136 pr_debug("%s: short packet %i\n", dev->name, len); 137 dev->stats.rx_length_errors++; 138 goto drop; 139 } 140 141 if (vi->mergeable_rx_bufs) { 142 struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb); 143 unsigned int copy; 144 char *p = page_address(skb_shinfo(skb)->frags[0].page); 145 146 if (len > PAGE_SIZE) 147 len = PAGE_SIZE; 148 len -= sizeof(struct virtio_net_hdr_mrg_rxbuf); 149 150 memcpy(hdr, p, sizeof(*mhdr)); 151 p += sizeof(*mhdr); 152 153 copy = len; 154 if (copy > skb_tailroom(skb)) 155 copy = skb_tailroom(skb); 156 157 memcpy(skb_put(skb, copy), p, copy); 158 159 len -= copy; 160 161 if (!len) { 162 give_a_page(vi, skb_shinfo(skb)->frags[0].page); 163 skb_shinfo(skb)->nr_frags--; 164 } else { 165 skb_shinfo(skb)->frags[0].page_offset += 166 sizeof(*mhdr) + copy; 167 skb_shinfo(skb)->frags[0].size = len; 168 skb->data_len += len; 169 skb->len += len; 170 } 171 172 while (--mhdr->num_buffers) { 173 struct sk_buff *nskb; 174 175 i = skb_shinfo(skb)->nr_frags; 176 if (i >= MAX_SKB_FRAGS) { 177 pr_debug("%s: packet too long %d\n", dev->name, 178 len); 179 dev->stats.rx_length_errors++; 180 goto drop; 181 } 182 183 nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len); 184 if (!nskb) { 185 pr_debug("%s: rx error: %d buffers missing\n", 186 dev->name, mhdr->num_buffers); 187 dev->stats.rx_length_errors++; 188 goto drop; 189 } 190 191 __skb_unlink(nskb, &vi->recv); 192 vi->num--; 193 194 skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0]; 195 skb_shinfo(nskb)->nr_frags = 0; 196 kfree_skb(nskb); 197 198 if (len > PAGE_SIZE) 199 len = PAGE_SIZE; 200 201 skb_shinfo(skb)->frags[i].size = len; 202 skb_shinfo(skb)->nr_frags++; 203 skb->data_len += len; 204 skb->len += len; 205 } 206 } else { 207 len -= sizeof(struct virtio_net_hdr); 208 209 if (len <= MAX_PACKET_LEN) 210 trim_pages(vi, skb); 211 212 err = pskb_trim(skb, len); 213 if (err) { 214 pr_debug("%s: pskb_trim failed %i %d\n", dev->name, 215 len, err); 216 dev->stats.rx_dropped++; 217 goto drop; 218 } 219 } 220 221 skb->truesize += skb->data_len; 222 dev->stats.rx_bytes += skb->len; 223 dev->stats.rx_packets++; 224 225 if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 226 pr_debug("Needs csum!\n"); 227 if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset)) 228 goto frame_err; 229 } 230 231 skb->protocol = eth_type_trans(skb, dev); 232 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 233 ntohs(skb->protocol), skb->len, skb->pkt_type); 234 235 if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { 236 pr_debug("GSO!\n"); 237 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 238 case VIRTIO_NET_HDR_GSO_TCPV4: 239 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 240 break; 241 case VIRTIO_NET_HDR_GSO_UDP: 242 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 243 break; 244 case VIRTIO_NET_HDR_GSO_TCPV6: 245 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 246 break; 247 default: 248 if (net_ratelimit()) 249 printk(KERN_WARNING "%s: bad gso type %u.\n", 250 dev->name, hdr->gso_type); 251 goto frame_err; 252 } 253 254 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) 255 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 256 257 skb_shinfo(skb)->gso_size = hdr->gso_size; 258 if (skb_shinfo(skb)->gso_size == 0) { 259 if (net_ratelimit()) 260 printk(KERN_WARNING "%s: zero gso size.\n", 261 dev->name); 262 goto frame_err; 263 } 264 265 /* Header must be checked, and gso_segs computed. */ 266 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 267 skb_shinfo(skb)->gso_segs = 0; 268 } 269 270 netif_receive_skb(skb); 271 return; 272 273 frame_err: 274 dev->stats.rx_frame_errors++; 275 drop: 276 dev_kfree_skb(skb); 277 } 278 279 static bool try_fill_recv_maxbufs(struct virtnet_info *vi, gfp_t gfp) 280 { 281 struct sk_buff *skb; 282 struct scatterlist sg[2+MAX_SKB_FRAGS]; 283 int num, err, i; 284 bool oom = false; 285 286 sg_init_table(sg, 2+MAX_SKB_FRAGS); 287 for (;;) { 288 struct virtio_net_hdr *hdr; 289 290 skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN + NET_IP_ALIGN); 291 if (unlikely(!skb)) { 292 oom = true; 293 break; 294 } 295 296 skb_reserve(skb, NET_IP_ALIGN); 297 skb_put(skb, MAX_PACKET_LEN); 298 299 hdr = skb_vnet_hdr(skb); 300 sg_set_buf(sg, hdr, sizeof(*hdr)); 301 302 if (vi->big_packets) { 303 for (i = 0; i < MAX_SKB_FRAGS; i++) { 304 skb_frag_t *f = &skb_shinfo(skb)->frags[i]; 305 f->page = get_a_page(vi, gfp); 306 if (!f->page) 307 break; 308 309 f->page_offset = 0; 310 f->size = PAGE_SIZE; 311 312 skb->data_len += PAGE_SIZE; 313 skb->len += PAGE_SIZE; 314 315 skb_shinfo(skb)->nr_frags++; 316 } 317 } 318 319 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; 320 skb_queue_head(&vi->recv, skb); 321 322 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb); 323 if (err) { 324 skb_unlink(skb, &vi->recv); 325 trim_pages(vi, skb); 326 kfree_skb(skb); 327 break; 328 } 329 vi->num++; 330 } 331 if (unlikely(vi->num > vi->max)) 332 vi->max = vi->num; 333 vi->rvq->vq_ops->kick(vi->rvq); 334 return !oom; 335 } 336 337 /* Returns false if we couldn't fill entirely (OOM). */ 338 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 339 { 340 struct sk_buff *skb; 341 struct scatterlist sg[1]; 342 int err; 343 bool oom = false; 344 345 if (!vi->mergeable_rx_bufs) 346 return try_fill_recv_maxbufs(vi, gfp); 347 348 for (;;) { 349 skb_frag_t *f; 350 351 skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN); 352 if (unlikely(!skb)) { 353 oom = true; 354 break; 355 } 356 357 skb_reserve(skb, NET_IP_ALIGN); 358 359 f = &skb_shinfo(skb)->frags[0]; 360 f->page = get_a_page(vi, gfp); 361 if (!f->page) { 362 oom = true; 363 kfree_skb(skb); 364 break; 365 } 366 367 f->page_offset = 0; 368 f->size = PAGE_SIZE; 369 370 skb_shinfo(skb)->nr_frags++; 371 372 sg_init_one(sg, page_address(f->page), PAGE_SIZE); 373 skb_queue_head(&vi->recv, skb); 374 375 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb); 376 if (err) { 377 skb_unlink(skb, &vi->recv); 378 kfree_skb(skb); 379 break; 380 } 381 vi->num++; 382 } 383 if (unlikely(vi->num > vi->max)) 384 vi->max = vi->num; 385 vi->rvq->vq_ops->kick(vi->rvq); 386 return !oom; 387 } 388 389 static void skb_recv_done(struct virtqueue *rvq) 390 { 391 struct virtnet_info *vi = rvq->vdev->priv; 392 /* Schedule NAPI, Suppress further interrupts if successful. */ 393 if (napi_schedule_prep(&vi->napi)) { 394 rvq->vq_ops->disable_cb(rvq); 395 __napi_schedule(&vi->napi); 396 } 397 } 398 399 static void refill_work(struct work_struct *work) 400 { 401 struct virtnet_info *vi; 402 bool still_empty; 403 404 vi = container_of(work, struct virtnet_info, refill.work); 405 napi_disable(&vi->napi); 406 try_fill_recv(vi, GFP_KERNEL); 407 still_empty = (vi->num == 0); 408 napi_enable(&vi->napi); 409 410 /* In theory, this can happen: if we don't get any buffers in 411 * we will *never* try to fill again. */ 412 if (still_empty) 413 schedule_delayed_work(&vi->refill, HZ/2); 414 } 415 416 static int virtnet_poll(struct napi_struct *napi, int budget) 417 { 418 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 419 struct sk_buff *skb = NULL; 420 unsigned int len, received = 0; 421 422 again: 423 while (received < budget && 424 (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) { 425 __skb_unlink(skb, &vi->recv); 426 receive_skb(vi->dev, skb, len); 427 vi->num--; 428 received++; 429 } 430 431 if (vi->num < vi->max / 2) { 432 if (!try_fill_recv(vi, GFP_ATOMIC)) 433 schedule_delayed_work(&vi->refill, 0); 434 } 435 436 /* Out of packets? */ 437 if (received < budget) { 438 napi_complete(napi); 439 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) 440 && napi_schedule_prep(napi)) { 441 vi->rvq->vq_ops->disable_cb(vi->rvq); 442 __napi_schedule(napi); 443 goto again; 444 } 445 } 446 447 return received; 448 } 449 450 static void free_old_xmit_skbs(struct virtnet_info *vi) 451 { 452 struct sk_buff *skb; 453 unsigned int len; 454 455 while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) { 456 pr_debug("Sent skb %p\n", skb); 457 __skb_unlink(skb, &vi->send); 458 vi->dev->stats.tx_bytes += skb->len; 459 vi->dev->stats.tx_packets++; 460 kfree_skb(skb); 461 } 462 } 463 464 /* If the virtio transport doesn't always notify us when all in-flight packets 465 * are consumed, we fall back to using this function on a timer to free them. */ 466 static void xmit_free(unsigned long data) 467 { 468 struct virtnet_info *vi = (void *)data; 469 470 netif_tx_lock(vi->dev); 471 472 free_old_xmit_skbs(vi); 473 474 if (!skb_queue_empty(&vi->send)) 475 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10)); 476 477 netif_tx_unlock(vi->dev); 478 } 479 480 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 481 { 482 int num, err; 483 struct scatterlist sg[2+MAX_SKB_FRAGS]; 484 struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb); 485 struct virtio_net_hdr *hdr = skb_vnet_hdr(skb); 486 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 487 488 sg_init_table(sg, 2+MAX_SKB_FRAGS); 489 490 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 491 492 if (skb->ip_summed == CHECKSUM_PARTIAL) { 493 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 494 hdr->csum_start = skb->csum_start - skb_headroom(skb); 495 hdr->csum_offset = skb->csum_offset; 496 } else { 497 hdr->flags = 0; 498 hdr->csum_offset = hdr->csum_start = 0; 499 } 500 501 if (skb_is_gso(skb)) { 502 hdr->hdr_len = skb_headlen(skb); 503 hdr->gso_size = skb_shinfo(skb)->gso_size; 504 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 505 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 506 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 507 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 508 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 509 hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP; 510 else 511 BUG(); 512 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 513 hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; 514 } else { 515 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; 516 hdr->gso_size = hdr->hdr_len = 0; 517 } 518 519 mhdr->num_buffers = 0; 520 521 /* Encode metadata header at front. */ 522 if (vi->mergeable_rx_bufs) 523 sg_set_buf(sg, mhdr, sizeof(*mhdr)); 524 else 525 sg_set_buf(sg, hdr, sizeof(*hdr)); 526 527 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; 528 529 err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb); 530 if (!err && !vi->free_in_tasklet) 531 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10)); 532 533 return err; 534 } 535 536 static void xmit_tasklet(unsigned long data) 537 { 538 struct virtnet_info *vi = (void *)data; 539 540 netif_tx_lock_bh(vi->dev); 541 if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) { 542 vi->svq->vq_ops->kick(vi->svq); 543 vi->last_xmit_skb = NULL; 544 } 545 if (vi->free_in_tasklet) 546 free_old_xmit_skbs(vi); 547 netif_tx_unlock_bh(vi->dev); 548 } 549 550 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 551 { 552 struct virtnet_info *vi = netdev_priv(dev); 553 554 again: 555 /* Free up any pending old buffers before queueing new ones. */ 556 free_old_xmit_skbs(vi); 557 558 /* If we has a buffer left over from last time, send it now. */ 559 if (unlikely(vi->last_xmit_skb) && 560 xmit_skb(vi, vi->last_xmit_skb) != 0) 561 goto stop_queue; 562 563 vi->last_xmit_skb = NULL; 564 565 /* Put new one in send queue and do transmit */ 566 if (likely(skb)) { 567 __skb_queue_head(&vi->send, skb); 568 if (xmit_skb(vi, skb) != 0) { 569 vi->last_xmit_skb = skb; 570 skb = NULL; 571 goto stop_queue; 572 } 573 } 574 done: 575 vi->svq->vq_ops->kick(vi->svq); 576 return NETDEV_TX_OK; 577 578 stop_queue: 579 pr_debug("%s: virtio not prepared to send\n", dev->name); 580 netif_stop_queue(dev); 581 582 /* Activate callback for using skbs: if this returns false it 583 * means some were used in the meantime. */ 584 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { 585 vi->svq->vq_ops->disable_cb(vi->svq); 586 netif_start_queue(dev); 587 goto again; 588 } 589 if (skb) { 590 /* Drop this skb: we only queue one. */ 591 vi->dev->stats.tx_dropped++; 592 kfree_skb(skb); 593 } 594 goto done; 595 } 596 597 static int virtnet_set_mac_address(struct net_device *dev, void *p) 598 { 599 struct virtnet_info *vi = netdev_priv(dev); 600 struct virtio_device *vdev = vi->vdev; 601 int ret; 602 603 ret = eth_mac_addr(dev, p); 604 if (ret) 605 return ret; 606 607 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 608 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 609 dev->dev_addr, dev->addr_len); 610 611 return 0; 612 } 613 614 #ifdef CONFIG_NET_POLL_CONTROLLER 615 static void virtnet_netpoll(struct net_device *dev) 616 { 617 struct virtnet_info *vi = netdev_priv(dev); 618 619 napi_schedule(&vi->napi); 620 } 621 #endif 622 623 static int virtnet_open(struct net_device *dev) 624 { 625 struct virtnet_info *vi = netdev_priv(dev); 626 627 napi_enable(&vi->napi); 628 629 /* If all buffers were filled by other side before we napi_enabled, we 630 * won't get another interrupt, so process any outstanding packets 631 * now. virtnet_poll wants re-enable the queue, so we disable here. 632 * We synchronize against interrupts via NAPI_STATE_SCHED */ 633 if (napi_schedule_prep(&vi->napi)) { 634 vi->rvq->vq_ops->disable_cb(vi->rvq); 635 __napi_schedule(&vi->napi); 636 } 637 return 0; 638 } 639 640 /* 641 * Send command via the control virtqueue and check status. Commands 642 * supported by the hypervisor, as indicated by feature bits, should 643 * never fail unless improperly formated. 644 */ 645 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 646 struct scatterlist *data, int out, int in) 647 { 648 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 649 struct virtio_net_ctrl_hdr ctrl; 650 virtio_net_ctrl_ack status = ~0; 651 unsigned int tmp; 652 int i; 653 654 /* Caller should know better */ 655 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 656 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 657 658 out++; /* Add header */ 659 in++; /* Add return status */ 660 661 ctrl.class = class; 662 ctrl.cmd = cmd; 663 664 sg_init_table(sg, out + in); 665 666 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 667 for_each_sg(data, s, out + in - 2, i) 668 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 669 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 670 671 BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi)); 672 673 vi->cvq->vq_ops->kick(vi->cvq); 674 675 /* 676 * Spin for a response, the kick causes an ioport write, trapping 677 * into the hypervisor, so the request should be handled immediately. 678 */ 679 while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp)) 680 cpu_relax(); 681 682 return status == VIRTIO_NET_OK; 683 } 684 685 static int virtnet_close(struct net_device *dev) 686 { 687 struct virtnet_info *vi = netdev_priv(dev); 688 689 napi_disable(&vi->napi); 690 691 return 0; 692 } 693 694 static int virtnet_set_tx_csum(struct net_device *dev, u32 data) 695 { 696 struct virtnet_info *vi = netdev_priv(dev); 697 struct virtio_device *vdev = vi->vdev; 698 699 if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) 700 return -ENOSYS; 701 702 return ethtool_op_set_tx_hw_csum(dev, data); 703 } 704 705 static void virtnet_set_rx_mode(struct net_device *dev) 706 { 707 struct virtnet_info *vi = netdev_priv(dev); 708 struct scatterlist sg[2]; 709 u8 promisc, allmulti; 710 struct virtio_net_ctrl_mac *mac_data; 711 struct dev_addr_list *addr; 712 struct netdev_hw_addr *ha; 713 void *buf; 714 int i; 715 716 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 717 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 718 return; 719 720 promisc = ((dev->flags & IFF_PROMISC) != 0); 721 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 722 723 sg_init_one(sg, &promisc, sizeof(promisc)); 724 725 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 726 VIRTIO_NET_CTRL_RX_PROMISC, 727 sg, 1, 0)) 728 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 729 promisc ? "en" : "dis"); 730 731 sg_init_one(sg, &allmulti, sizeof(allmulti)); 732 733 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 734 VIRTIO_NET_CTRL_RX_ALLMULTI, 735 sg, 1, 0)) 736 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 737 allmulti ? "en" : "dis"); 738 739 /* MAC filter - use one buffer for both lists */ 740 mac_data = buf = kzalloc(((dev->uc.count + dev->mc_count) * ETH_ALEN) + 741 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 742 if (!buf) { 743 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 744 return; 745 } 746 747 sg_init_table(sg, 2); 748 749 /* Store the unicast list and count in the front of the buffer */ 750 mac_data->entries = dev->uc.count; 751 i = 0; 752 list_for_each_entry(ha, &dev->uc.list, list) 753 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 754 755 sg_set_buf(&sg[0], mac_data, 756 sizeof(mac_data->entries) + (dev->uc.count * ETH_ALEN)); 757 758 /* multicast list and count fill the end */ 759 mac_data = (void *)&mac_data->macs[dev->uc.count][0]; 760 761 mac_data->entries = dev->mc_count; 762 addr = dev->mc_list; 763 for (i = 0; i < dev->mc_count; i++, addr = addr->next) 764 memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN); 765 766 sg_set_buf(&sg[1], mac_data, 767 sizeof(mac_data->entries) + (dev->mc_count * ETH_ALEN)); 768 769 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 770 VIRTIO_NET_CTRL_MAC_TABLE_SET, 771 sg, 2, 0)) 772 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 773 774 kfree(buf); 775 } 776 777 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 778 { 779 struct virtnet_info *vi = netdev_priv(dev); 780 struct scatterlist sg; 781 782 sg_init_one(&sg, &vid, sizeof(vid)); 783 784 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 785 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 786 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 787 } 788 789 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 790 { 791 struct virtnet_info *vi = netdev_priv(dev); 792 struct scatterlist sg; 793 794 sg_init_one(&sg, &vid, sizeof(vid)); 795 796 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 797 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 798 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 799 } 800 801 static const struct ethtool_ops virtnet_ethtool_ops = { 802 .set_tx_csum = virtnet_set_tx_csum, 803 .set_sg = ethtool_op_set_sg, 804 .set_tso = ethtool_op_set_tso, 805 .set_ufo = ethtool_op_set_ufo, 806 .get_link = ethtool_op_get_link, 807 }; 808 809 #define MIN_MTU 68 810 #define MAX_MTU 65535 811 812 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 813 { 814 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 815 return -EINVAL; 816 dev->mtu = new_mtu; 817 return 0; 818 } 819 820 static const struct net_device_ops virtnet_netdev = { 821 .ndo_open = virtnet_open, 822 .ndo_stop = virtnet_close, 823 .ndo_start_xmit = start_xmit, 824 .ndo_validate_addr = eth_validate_addr, 825 .ndo_set_mac_address = virtnet_set_mac_address, 826 .ndo_set_rx_mode = virtnet_set_rx_mode, 827 .ndo_change_mtu = virtnet_change_mtu, 828 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 829 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 830 #ifdef CONFIG_NET_POLL_CONTROLLER 831 .ndo_poll_controller = virtnet_netpoll, 832 #endif 833 }; 834 835 static void virtnet_update_status(struct virtnet_info *vi) 836 { 837 u16 v; 838 839 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 840 return; 841 842 vi->vdev->config->get(vi->vdev, 843 offsetof(struct virtio_net_config, status), 844 &v, sizeof(v)); 845 846 /* Ignore unknown (future) status bits */ 847 v &= VIRTIO_NET_S_LINK_UP; 848 849 if (vi->status == v) 850 return; 851 852 vi->status = v; 853 854 if (vi->status & VIRTIO_NET_S_LINK_UP) { 855 netif_carrier_on(vi->dev); 856 netif_wake_queue(vi->dev); 857 } else { 858 netif_carrier_off(vi->dev); 859 netif_stop_queue(vi->dev); 860 } 861 } 862 863 static void virtnet_config_changed(struct virtio_device *vdev) 864 { 865 struct virtnet_info *vi = vdev->priv; 866 867 virtnet_update_status(vi); 868 } 869 870 static int virtnet_probe(struct virtio_device *vdev) 871 { 872 int err; 873 struct net_device *dev; 874 struct virtnet_info *vi; 875 struct virtqueue *vqs[3]; 876 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 877 const char *names[] = { "input", "output", "control" }; 878 int nvqs; 879 880 /* Allocate ourselves a network device with room for our info */ 881 dev = alloc_etherdev(sizeof(struct virtnet_info)); 882 if (!dev) 883 return -ENOMEM; 884 885 /* Set up network device as normal. */ 886 dev->netdev_ops = &virtnet_netdev; 887 dev->features = NETIF_F_HIGHDMA; 888 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 889 SET_NETDEV_DEV(dev, &vdev->dev); 890 891 /* Do we support "hardware" checksums? */ 892 if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 893 /* This opens up the world of extra features. */ 894 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 895 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 896 dev->features |= NETIF_F_TSO | NETIF_F_UFO 897 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 898 } 899 /* Individual feature bits: what can host handle? */ 900 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 901 dev->features |= NETIF_F_TSO; 902 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 903 dev->features |= NETIF_F_TSO6; 904 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 905 dev->features |= NETIF_F_TSO_ECN; 906 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 907 dev->features |= NETIF_F_UFO; 908 } 909 910 /* Configuration may specify what MAC to use. Otherwise random. */ 911 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 912 vdev->config->get(vdev, 913 offsetof(struct virtio_net_config, mac), 914 dev->dev_addr, dev->addr_len); 915 } else 916 random_ether_addr(dev->dev_addr); 917 918 /* Set up our device-specific information */ 919 vi = netdev_priv(dev); 920 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 921 vi->dev = dev; 922 vi->vdev = vdev; 923 vdev->priv = vi; 924 vi->pages = NULL; 925 INIT_DELAYED_WORK(&vi->refill, refill_work); 926 927 /* If they give us a callback when all buffers are done, we don't need 928 * the timer. */ 929 vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY); 930 931 /* If we can receive ANY GSO packets, we must allocate large ones. */ 932 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) 933 || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) 934 || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 935 vi->big_packets = true; 936 937 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 938 vi->mergeable_rx_bufs = true; 939 940 /* We expect two virtqueues, receive then send, 941 * and optionally control. */ 942 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 943 944 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 945 if (err) 946 goto free; 947 948 vi->rvq = vqs[0]; 949 vi->svq = vqs[1]; 950 951 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 952 vi->cvq = vqs[2]; 953 954 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 955 dev->features |= NETIF_F_HW_VLAN_FILTER; 956 } 957 958 /* Initialize our empty receive and send queues. */ 959 skb_queue_head_init(&vi->recv); 960 skb_queue_head_init(&vi->send); 961 962 tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi); 963 964 if (!vi->free_in_tasklet) 965 setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi); 966 967 err = register_netdev(dev); 968 if (err) { 969 pr_debug("virtio_net: registering device failed\n"); 970 goto free_vqs; 971 } 972 973 /* Last of all, set up some receive buffers. */ 974 try_fill_recv(vi, GFP_KERNEL); 975 976 /* If we didn't even get one input buffer, we're useless. */ 977 if (vi->num == 0) { 978 err = -ENOMEM; 979 goto unregister; 980 } 981 982 vi->status = VIRTIO_NET_S_LINK_UP; 983 virtnet_update_status(vi); 984 netif_carrier_on(dev); 985 986 pr_debug("virtnet: registered device %s\n", dev->name); 987 return 0; 988 989 unregister: 990 unregister_netdev(dev); 991 cancel_delayed_work_sync(&vi->refill); 992 free_vqs: 993 vdev->config->del_vqs(vdev); 994 free: 995 free_netdev(dev); 996 return err; 997 } 998 999 static void virtnet_remove(struct virtio_device *vdev) 1000 { 1001 struct virtnet_info *vi = vdev->priv; 1002 struct sk_buff *skb; 1003 1004 /* Stop all the virtqueues. */ 1005 vdev->config->reset(vdev); 1006 1007 if (!vi->free_in_tasklet) 1008 del_timer_sync(&vi->xmit_free_timer); 1009 1010 /* Free our skbs in send and recv queues, if any. */ 1011 while ((skb = __skb_dequeue(&vi->recv)) != NULL) { 1012 kfree_skb(skb); 1013 vi->num--; 1014 } 1015 __skb_queue_purge(&vi->send); 1016 1017 BUG_ON(vi->num != 0); 1018 1019 unregister_netdev(vi->dev); 1020 cancel_delayed_work_sync(&vi->refill); 1021 1022 vdev->config->del_vqs(vi->vdev); 1023 1024 while (vi->pages) 1025 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1026 1027 free_netdev(vi->dev); 1028 } 1029 1030 static struct virtio_device_id id_table[] = { 1031 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1032 { 0 }, 1033 }; 1034 1035 static unsigned int features[] = { 1036 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1037 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1038 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1039 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1040 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1041 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1042 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1043 VIRTIO_F_NOTIFY_ON_EMPTY, 1044 }; 1045 1046 static struct virtio_driver virtio_net = { 1047 .feature_table = features, 1048 .feature_table_size = ARRAY_SIZE(features), 1049 .driver.name = KBUILD_MODNAME, 1050 .driver.owner = THIS_MODULE, 1051 .id_table = id_table, 1052 .probe = virtnet_probe, 1053 .remove = __devexit_p(virtnet_remove), 1054 .config_changed = virtnet_config_changed, 1055 }; 1056 1057 static int __init init(void) 1058 { 1059 return register_virtio_driver(&virtio_net); 1060 } 1061 1062 static void __exit fini(void) 1063 { 1064 unregister_virtio_driver(&virtio_net); 1065 } 1066 module_init(init); 1067 module_exit(fini); 1068 1069 MODULE_DEVICE_TABLE(virtio, id_table); 1070 MODULE_DESCRIPTION("Virtio network driver"); 1071 MODULE_LICENSE("GPL"); 1072