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 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 /* Number of input buffers, and max we've ever had. */ 51 unsigned int num, max; 52 53 /* I like... big packets and I cannot lie! */ 54 bool big_packets; 55 56 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 57 bool mergeable_rx_bufs; 58 59 /* Work struct for refilling if we run low on memory. */ 60 struct delayed_work refill; 61 62 /* Chain pages by the private ptr. */ 63 struct page *pages; 64 }; 65 66 struct skb_vnet_hdr { 67 union { 68 struct virtio_net_hdr hdr; 69 struct virtio_net_hdr_mrg_rxbuf mhdr; 70 }; 71 unsigned int num_sg; 72 }; 73 74 struct padded_vnet_hdr { 75 struct virtio_net_hdr hdr; 76 /* 77 * virtio_net_hdr should be in a separated sg buffer because of a 78 * QEMU bug, and data sg buffer shares same page with this header sg. 79 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 80 */ 81 char padding[6]; 82 }; 83 84 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 85 { 86 return (struct skb_vnet_hdr *)skb->cb; 87 } 88 89 /* 90 * private is used to chain pages for big packets, put the whole 91 * most recent used list in the beginning for reuse 92 */ 93 static void give_pages(struct virtnet_info *vi, struct page *page) 94 { 95 struct page *end; 96 97 /* Find end of list, sew whole thing into vi->pages. */ 98 for (end = page; end->private; end = (struct page *)end->private); 99 end->private = (unsigned long)vi->pages; 100 vi->pages = page; 101 } 102 103 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 104 { 105 struct page *p = vi->pages; 106 107 if (p) { 108 vi->pages = (struct page *)p->private; 109 /* clear private here, it is used to chain pages */ 110 p->private = 0; 111 } else 112 p = alloc_page(gfp_mask); 113 return p; 114 } 115 116 static void skb_xmit_done(struct virtqueue *svq) 117 { 118 struct virtnet_info *vi = svq->vdev->priv; 119 120 /* Suppress further interrupts. */ 121 svq->vq_ops->disable_cb(svq); 122 123 /* We were probably waiting for more output buffers. */ 124 netif_wake_queue(vi->dev); 125 } 126 127 static void set_skb_frag(struct sk_buff *skb, struct page *page, 128 unsigned int offset, unsigned int *len) 129 { 130 int i = skb_shinfo(skb)->nr_frags; 131 skb_frag_t *f; 132 133 f = &skb_shinfo(skb)->frags[i]; 134 f->size = min((unsigned)PAGE_SIZE - offset, *len); 135 f->page_offset = offset; 136 f->page = page; 137 138 skb->data_len += f->size; 139 skb->len += f->size; 140 skb_shinfo(skb)->nr_frags++; 141 *len -= f->size; 142 } 143 144 static struct sk_buff *page_to_skb(struct virtnet_info *vi, 145 struct page *page, unsigned int len) 146 { 147 struct sk_buff *skb; 148 struct skb_vnet_hdr *hdr; 149 unsigned int copy, hdr_len, offset; 150 char *p; 151 152 p = page_address(page); 153 154 /* copy small packet so we can reuse these pages for small data */ 155 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 156 if (unlikely(!skb)) 157 return NULL; 158 159 hdr = skb_vnet_hdr(skb); 160 161 if (vi->mergeable_rx_bufs) { 162 hdr_len = sizeof hdr->mhdr; 163 offset = hdr_len; 164 } else { 165 hdr_len = sizeof hdr->hdr; 166 offset = sizeof(struct padded_vnet_hdr); 167 } 168 169 memcpy(hdr, p, hdr_len); 170 171 len -= hdr_len; 172 p += offset; 173 174 copy = len; 175 if (copy > skb_tailroom(skb)) 176 copy = skb_tailroom(skb); 177 memcpy(skb_put(skb, copy), p, copy); 178 179 len -= copy; 180 offset += copy; 181 182 while (len) { 183 set_skb_frag(skb, page, offset, &len); 184 page = (struct page *)page->private; 185 offset = 0; 186 } 187 188 if (page) 189 give_pages(vi, page); 190 191 return skb; 192 } 193 194 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) 195 { 196 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 197 struct page *page; 198 int num_buf, i, len; 199 200 num_buf = hdr->mhdr.num_buffers; 201 while (--num_buf) { 202 i = skb_shinfo(skb)->nr_frags; 203 if (i >= MAX_SKB_FRAGS) { 204 pr_debug("%s: packet too long\n", skb->dev->name); 205 skb->dev->stats.rx_length_errors++; 206 return -EINVAL; 207 } 208 209 page = vi->rvq->vq_ops->get_buf(vi->rvq, &len); 210 if (!page) { 211 pr_debug("%s: rx error: %d buffers missing\n", 212 skb->dev->name, hdr->mhdr.num_buffers); 213 skb->dev->stats.rx_length_errors++; 214 return -EINVAL; 215 } 216 if (len > PAGE_SIZE) 217 len = PAGE_SIZE; 218 219 set_skb_frag(skb, page, 0, &len); 220 221 --vi->num; 222 } 223 return 0; 224 } 225 226 static void receive_buf(struct net_device *dev, void *buf, unsigned int len) 227 { 228 struct virtnet_info *vi = netdev_priv(dev); 229 struct sk_buff *skb; 230 struct page *page; 231 struct skb_vnet_hdr *hdr; 232 233 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 234 pr_debug("%s: short packet %i\n", dev->name, len); 235 dev->stats.rx_length_errors++; 236 if (vi->mergeable_rx_bufs || vi->big_packets) 237 give_pages(vi, buf); 238 else 239 dev_kfree_skb(buf); 240 return; 241 } 242 243 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 244 skb = buf; 245 len -= sizeof(struct virtio_net_hdr); 246 skb_trim(skb, len); 247 } else { 248 page = buf; 249 skb = page_to_skb(vi, page, len); 250 if (unlikely(!skb)) { 251 dev->stats.rx_dropped++; 252 give_pages(vi, page); 253 return; 254 } 255 if (vi->mergeable_rx_bufs) 256 if (receive_mergeable(vi, skb)) { 257 dev_kfree_skb(skb); 258 return; 259 } 260 } 261 262 hdr = skb_vnet_hdr(skb); 263 skb->truesize += skb->data_len; 264 dev->stats.rx_bytes += skb->len; 265 dev->stats.rx_packets++; 266 267 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 268 pr_debug("Needs csum!\n"); 269 if (!skb_partial_csum_set(skb, 270 hdr->hdr.csum_start, 271 hdr->hdr.csum_offset)) 272 goto frame_err; 273 } 274 275 skb->protocol = eth_type_trans(skb, dev); 276 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 277 ntohs(skb->protocol), skb->len, skb->pkt_type); 278 279 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 280 pr_debug("GSO!\n"); 281 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 282 case VIRTIO_NET_HDR_GSO_TCPV4: 283 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 284 break; 285 case VIRTIO_NET_HDR_GSO_UDP: 286 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 287 break; 288 case VIRTIO_NET_HDR_GSO_TCPV6: 289 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 290 break; 291 default: 292 if (net_ratelimit()) 293 printk(KERN_WARNING "%s: bad gso type %u.\n", 294 dev->name, hdr->hdr.gso_type); 295 goto frame_err; 296 } 297 298 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 299 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 300 301 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 302 if (skb_shinfo(skb)->gso_size == 0) { 303 if (net_ratelimit()) 304 printk(KERN_WARNING "%s: zero gso size.\n", 305 dev->name); 306 goto frame_err; 307 } 308 309 /* Header must be checked, and gso_segs computed. */ 310 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 311 skb_shinfo(skb)->gso_segs = 0; 312 } 313 314 netif_receive_skb(skb); 315 return; 316 317 frame_err: 318 dev->stats.rx_frame_errors++; 319 dev_kfree_skb(skb); 320 } 321 322 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) 323 { 324 struct sk_buff *skb; 325 struct skb_vnet_hdr *hdr; 326 struct scatterlist sg[2]; 327 int err; 328 329 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); 330 if (unlikely(!skb)) 331 return -ENOMEM; 332 333 skb_put(skb, MAX_PACKET_LEN); 334 335 hdr = skb_vnet_hdr(skb); 336 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr); 337 338 skb_to_sgvec(skb, sg + 1, 0, skb->len); 339 340 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 2, skb); 341 if (err < 0) 342 dev_kfree_skb(skb); 343 344 return err; 345 } 346 347 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 348 { 349 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 350 struct page *first, *list = NULL; 351 char *p; 352 int i, err, offset; 353 354 /* page in sg[MAX_SKB_FRAGS + 1] is list tail */ 355 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 356 first = get_a_page(vi, gfp); 357 if (!first) { 358 if (list) 359 give_pages(vi, list); 360 return -ENOMEM; 361 } 362 sg_set_buf(&sg[i], page_address(first), PAGE_SIZE); 363 364 /* chain new page in list head to match sg */ 365 first->private = (unsigned long)list; 366 list = first; 367 } 368 369 first = get_a_page(vi, gfp); 370 if (!first) { 371 give_pages(vi, list); 372 return -ENOMEM; 373 } 374 p = page_address(first); 375 376 /* sg[0], sg[1] share the same page */ 377 /* a separated sg[0] for virtio_net_hdr only during to QEMU bug*/ 378 sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr)); 379 380 /* sg[1] for data packet, from offset */ 381 offset = sizeof(struct padded_vnet_hdr); 382 sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset); 383 384 /* chain first in list head */ 385 first->private = (unsigned long)list; 386 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2, 387 first); 388 if (err < 0) 389 give_pages(vi, first); 390 391 return err; 392 } 393 394 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 395 { 396 struct page *page; 397 struct scatterlist sg; 398 int err; 399 400 page = get_a_page(vi, gfp); 401 if (!page) 402 return -ENOMEM; 403 404 sg_init_one(&sg, page_address(page), PAGE_SIZE); 405 406 err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page); 407 if (err < 0) 408 give_pages(vi, page); 409 410 return err; 411 } 412 413 /* Returns false if we couldn't fill entirely (OOM). */ 414 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 415 { 416 int err; 417 bool oom = false; 418 419 do { 420 if (vi->mergeable_rx_bufs) 421 err = add_recvbuf_mergeable(vi, gfp); 422 else if (vi->big_packets) 423 err = add_recvbuf_big(vi, gfp); 424 else 425 err = add_recvbuf_small(vi, gfp); 426 427 if (err < 0) { 428 oom = true; 429 break; 430 } 431 ++vi->num; 432 } while (err > 0); 433 if (unlikely(vi->num > vi->max)) 434 vi->max = vi->num; 435 vi->rvq->vq_ops->kick(vi->rvq); 436 return !oom; 437 } 438 439 static void skb_recv_done(struct virtqueue *rvq) 440 { 441 struct virtnet_info *vi = rvq->vdev->priv; 442 /* Schedule NAPI, Suppress further interrupts if successful. */ 443 if (napi_schedule_prep(&vi->napi)) { 444 rvq->vq_ops->disable_cb(rvq); 445 __napi_schedule(&vi->napi); 446 } 447 } 448 449 static void refill_work(struct work_struct *work) 450 { 451 struct virtnet_info *vi; 452 bool still_empty; 453 454 vi = container_of(work, struct virtnet_info, refill.work); 455 napi_disable(&vi->napi); 456 still_empty = !try_fill_recv(vi, GFP_KERNEL); 457 napi_enable(&vi->napi); 458 459 /* In theory, this can happen: if we don't get any buffers in 460 * we will *never* try to fill again. */ 461 if (still_empty) 462 schedule_delayed_work(&vi->refill, HZ/2); 463 } 464 465 static int virtnet_poll(struct napi_struct *napi, int budget) 466 { 467 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 468 void *buf; 469 unsigned int len, received = 0; 470 471 again: 472 while (received < budget && 473 (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) { 474 receive_buf(vi->dev, buf, len); 475 --vi->num; 476 received++; 477 } 478 479 if (vi->num < vi->max / 2) { 480 if (!try_fill_recv(vi, GFP_ATOMIC)) 481 schedule_delayed_work(&vi->refill, 0); 482 } 483 484 /* Out of packets? */ 485 if (received < budget) { 486 napi_complete(napi); 487 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) && 488 napi_schedule_prep(napi)) { 489 vi->rvq->vq_ops->disable_cb(vi->rvq); 490 __napi_schedule(napi); 491 goto again; 492 } 493 } 494 495 return received; 496 } 497 498 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) 499 { 500 struct sk_buff *skb; 501 unsigned int len, tot_sgs = 0; 502 503 while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) { 504 pr_debug("Sent skb %p\n", skb); 505 vi->dev->stats.tx_bytes += skb->len; 506 vi->dev->stats.tx_packets++; 507 tot_sgs += skb_vnet_hdr(skb)->num_sg; 508 dev_kfree_skb_any(skb); 509 } 510 return tot_sgs; 511 } 512 513 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 514 { 515 struct scatterlist sg[2+MAX_SKB_FRAGS]; 516 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 517 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 518 519 sg_init_table(sg, 2+MAX_SKB_FRAGS); 520 521 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 522 523 if (skb->ip_summed == CHECKSUM_PARTIAL) { 524 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 525 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb); 526 hdr->hdr.csum_offset = skb->csum_offset; 527 } else { 528 hdr->hdr.flags = 0; 529 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 530 } 531 532 if (skb_is_gso(skb)) { 533 hdr->hdr.hdr_len = skb_headlen(skb); 534 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 535 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 536 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 537 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 538 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 539 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 540 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 541 else 542 BUG(); 543 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 544 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 545 } else { 546 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 547 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 548 } 549 550 hdr->mhdr.num_buffers = 0; 551 552 /* Encode metadata header at front. */ 553 if (vi->mergeable_rx_bufs) 554 sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr); 555 else 556 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr); 557 558 hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; 559 return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb); 560 } 561 562 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 563 { 564 struct virtnet_info *vi = netdev_priv(dev); 565 int capacity; 566 567 again: 568 /* Free up any pending old buffers before queueing new ones. */ 569 free_old_xmit_skbs(vi); 570 571 /* Try to transmit */ 572 capacity = xmit_skb(vi, skb); 573 574 /* This can happen with OOM and indirect buffers. */ 575 if (unlikely(capacity < 0)) { 576 netif_stop_queue(dev); 577 dev_warn(&dev->dev, "Unexpected full queue\n"); 578 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { 579 vi->svq->vq_ops->disable_cb(vi->svq); 580 netif_start_queue(dev); 581 goto again; 582 } 583 return NETDEV_TX_BUSY; 584 } 585 vi->svq->vq_ops->kick(vi->svq); 586 587 /* Don't wait up for transmitted skbs to be freed. */ 588 skb_orphan(skb); 589 nf_reset(skb); 590 591 /* Apparently nice girls don't return TX_BUSY; stop the queue 592 * before it gets out of hand. Naturally, this wastes entries. */ 593 if (capacity < 2+MAX_SKB_FRAGS) { 594 netif_stop_queue(dev); 595 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { 596 /* More just got used, free them then recheck. */ 597 capacity += free_old_xmit_skbs(vi); 598 if (capacity >= 2+MAX_SKB_FRAGS) { 599 netif_start_queue(dev); 600 vi->svq->vq_ops->disable_cb(vi->svq); 601 } 602 } 603 } 604 605 return NETDEV_TX_OK; 606 } 607 608 static int virtnet_set_mac_address(struct net_device *dev, void *p) 609 { 610 struct virtnet_info *vi = netdev_priv(dev); 611 struct virtio_device *vdev = vi->vdev; 612 int ret; 613 614 ret = eth_mac_addr(dev, p); 615 if (ret) 616 return ret; 617 618 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 619 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 620 dev->dev_addr, dev->addr_len); 621 622 return 0; 623 } 624 625 #ifdef CONFIG_NET_POLL_CONTROLLER 626 static void virtnet_netpoll(struct net_device *dev) 627 { 628 struct virtnet_info *vi = netdev_priv(dev); 629 630 napi_schedule(&vi->napi); 631 } 632 #endif 633 634 static int virtnet_open(struct net_device *dev) 635 { 636 struct virtnet_info *vi = netdev_priv(dev); 637 638 napi_enable(&vi->napi); 639 640 /* If all buffers were filled by other side before we napi_enabled, we 641 * won't get another interrupt, so process any outstanding packets 642 * now. virtnet_poll wants re-enable the queue, so we disable here. 643 * We synchronize against interrupts via NAPI_STATE_SCHED */ 644 if (napi_schedule_prep(&vi->napi)) { 645 vi->rvq->vq_ops->disable_cb(vi->rvq); 646 __napi_schedule(&vi->napi); 647 } 648 return 0; 649 } 650 651 /* 652 * Send command via the control virtqueue and check status. Commands 653 * supported by the hypervisor, as indicated by feature bits, should 654 * never fail unless improperly formated. 655 */ 656 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 657 struct scatterlist *data, int out, int in) 658 { 659 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 660 struct virtio_net_ctrl_hdr ctrl; 661 virtio_net_ctrl_ack status = ~0; 662 unsigned int tmp; 663 int i; 664 665 /* Caller should know better */ 666 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 667 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 668 669 out++; /* Add header */ 670 in++; /* Add return status */ 671 672 ctrl.class = class; 673 ctrl.cmd = cmd; 674 675 sg_init_table(sg, out + in); 676 677 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 678 for_each_sg(data, s, out + in - 2, i) 679 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 680 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 681 682 BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0); 683 684 vi->cvq->vq_ops->kick(vi->cvq); 685 686 /* 687 * Spin for a response, the kick causes an ioport write, trapping 688 * into the hypervisor, so the request should be handled immediately. 689 */ 690 while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp)) 691 cpu_relax(); 692 693 return status == VIRTIO_NET_OK; 694 } 695 696 static int virtnet_close(struct net_device *dev) 697 { 698 struct virtnet_info *vi = netdev_priv(dev); 699 700 napi_disable(&vi->napi); 701 702 return 0; 703 } 704 705 static int virtnet_set_tx_csum(struct net_device *dev, u32 data) 706 { 707 struct virtnet_info *vi = netdev_priv(dev); 708 struct virtio_device *vdev = vi->vdev; 709 710 if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) 711 return -ENOSYS; 712 713 return ethtool_op_set_tx_hw_csum(dev, data); 714 } 715 716 static void virtnet_set_rx_mode(struct net_device *dev) 717 { 718 struct virtnet_info *vi = netdev_priv(dev); 719 struct scatterlist sg[2]; 720 u8 promisc, allmulti; 721 struct virtio_net_ctrl_mac *mac_data; 722 struct dev_addr_list *addr; 723 struct netdev_hw_addr *ha; 724 int uc_count; 725 int mc_count; 726 void *buf; 727 int i; 728 729 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 730 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 731 return; 732 733 promisc = ((dev->flags & IFF_PROMISC) != 0); 734 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 735 736 sg_init_one(sg, &promisc, sizeof(promisc)); 737 738 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 739 VIRTIO_NET_CTRL_RX_PROMISC, 740 sg, 1, 0)) 741 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 742 promisc ? "en" : "dis"); 743 744 sg_init_one(sg, &allmulti, sizeof(allmulti)); 745 746 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 747 VIRTIO_NET_CTRL_RX_ALLMULTI, 748 sg, 1, 0)) 749 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 750 allmulti ? "en" : "dis"); 751 752 uc_count = netdev_uc_count(dev); 753 mc_count = netdev_mc_count(dev); 754 /* MAC filter - use one buffer for both lists */ 755 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 756 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 757 mac_data = buf; 758 if (!buf) { 759 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 760 return; 761 } 762 763 sg_init_table(sg, 2); 764 765 /* Store the unicast list and count in the front of the buffer */ 766 mac_data->entries = uc_count; 767 i = 0; 768 netdev_for_each_uc_addr(ha, dev) 769 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 770 771 sg_set_buf(&sg[0], mac_data, 772 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 773 774 /* multicast list and count fill the end */ 775 mac_data = (void *)&mac_data->macs[uc_count][0]; 776 777 mac_data->entries = mc_count; 778 i = 0; 779 netdev_for_each_mc_addr(addr, dev) 780 memcpy(&mac_data->macs[i++][0], addr->da_addr, ETH_ALEN); 781 782 sg_set_buf(&sg[1], mac_data, 783 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 784 785 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 786 VIRTIO_NET_CTRL_MAC_TABLE_SET, 787 sg, 2, 0)) 788 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 789 790 kfree(buf); 791 } 792 793 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 794 { 795 struct virtnet_info *vi = netdev_priv(dev); 796 struct scatterlist sg; 797 798 sg_init_one(&sg, &vid, sizeof(vid)); 799 800 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 801 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 802 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 803 } 804 805 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 806 { 807 struct virtnet_info *vi = netdev_priv(dev); 808 struct scatterlist sg; 809 810 sg_init_one(&sg, &vid, sizeof(vid)); 811 812 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 813 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 814 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 815 } 816 817 static const struct ethtool_ops virtnet_ethtool_ops = { 818 .set_tx_csum = virtnet_set_tx_csum, 819 .set_sg = ethtool_op_set_sg, 820 .set_tso = ethtool_op_set_tso, 821 .set_ufo = ethtool_op_set_ufo, 822 .get_link = ethtool_op_get_link, 823 }; 824 825 #define MIN_MTU 68 826 #define MAX_MTU 65535 827 828 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 829 { 830 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 831 return -EINVAL; 832 dev->mtu = new_mtu; 833 return 0; 834 } 835 836 static const struct net_device_ops virtnet_netdev = { 837 .ndo_open = virtnet_open, 838 .ndo_stop = virtnet_close, 839 .ndo_start_xmit = start_xmit, 840 .ndo_validate_addr = eth_validate_addr, 841 .ndo_set_mac_address = virtnet_set_mac_address, 842 .ndo_set_rx_mode = virtnet_set_rx_mode, 843 .ndo_change_mtu = virtnet_change_mtu, 844 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 845 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 846 #ifdef CONFIG_NET_POLL_CONTROLLER 847 .ndo_poll_controller = virtnet_netpoll, 848 #endif 849 }; 850 851 static void virtnet_update_status(struct virtnet_info *vi) 852 { 853 u16 v; 854 855 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 856 return; 857 858 vi->vdev->config->get(vi->vdev, 859 offsetof(struct virtio_net_config, status), 860 &v, sizeof(v)); 861 862 /* Ignore unknown (future) status bits */ 863 v &= VIRTIO_NET_S_LINK_UP; 864 865 if (vi->status == v) 866 return; 867 868 vi->status = v; 869 870 if (vi->status & VIRTIO_NET_S_LINK_UP) { 871 netif_carrier_on(vi->dev); 872 netif_wake_queue(vi->dev); 873 } else { 874 netif_carrier_off(vi->dev); 875 netif_stop_queue(vi->dev); 876 } 877 } 878 879 static void virtnet_config_changed(struct virtio_device *vdev) 880 { 881 struct virtnet_info *vi = vdev->priv; 882 883 virtnet_update_status(vi); 884 } 885 886 static int virtnet_probe(struct virtio_device *vdev) 887 { 888 int err; 889 struct net_device *dev; 890 struct virtnet_info *vi; 891 struct virtqueue *vqs[3]; 892 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 893 const char *names[] = { "input", "output", "control" }; 894 int nvqs; 895 896 /* Allocate ourselves a network device with room for our info */ 897 dev = alloc_etherdev(sizeof(struct virtnet_info)); 898 if (!dev) 899 return -ENOMEM; 900 901 /* Set up network device as normal. */ 902 dev->netdev_ops = &virtnet_netdev; 903 dev->features = NETIF_F_HIGHDMA; 904 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 905 SET_NETDEV_DEV(dev, &vdev->dev); 906 907 /* Do we support "hardware" checksums? */ 908 if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 909 /* This opens up the world of extra features. */ 910 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 911 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 912 dev->features |= NETIF_F_TSO | NETIF_F_UFO 913 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 914 } 915 /* Individual feature bits: what can host handle? */ 916 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 917 dev->features |= NETIF_F_TSO; 918 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 919 dev->features |= NETIF_F_TSO6; 920 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 921 dev->features |= NETIF_F_TSO_ECN; 922 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 923 dev->features |= NETIF_F_UFO; 924 } 925 926 /* Configuration may specify what MAC to use. Otherwise random. */ 927 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 928 vdev->config->get(vdev, 929 offsetof(struct virtio_net_config, mac), 930 dev->dev_addr, dev->addr_len); 931 } else 932 random_ether_addr(dev->dev_addr); 933 934 /* Set up our device-specific information */ 935 vi = netdev_priv(dev); 936 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 937 vi->dev = dev; 938 vi->vdev = vdev; 939 vdev->priv = vi; 940 vi->pages = NULL; 941 INIT_DELAYED_WORK(&vi->refill, refill_work); 942 943 /* If we can receive ANY GSO packets, we must allocate large ones. */ 944 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 945 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 946 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 947 vi->big_packets = true; 948 949 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 950 vi->mergeable_rx_bufs = true; 951 952 /* We expect two virtqueues, receive then send, 953 * and optionally control. */ 954 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 955 956 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 957 if (err) 958 goto free; 959 960 vi->rvq = vqs[0]; 961 vi->svq = vqs[1]; 962 963 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 964 vi->cvq = vqs[2]; 965 966 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 967 dev->features |= NETIF_F_HW_VLAN_FILTER; 968 } 969 970 err = register_netdev(dev); 971 if (err) { 972 pr_debug("virtio_net: registering device failed\n"); 973 goto free_vqs; 974 } 975 976 /* Last of all, set up some receive buffers. */ 977 try_fill_recv(vi, GFP_KERNEL); 978 979 /* If we didn't even get one input buffer, we're useless. */ 980 if (vi->num == 0) { 981 err = -ENOMEM; 982 goto unregister; 983 } 984 985 vi->status = VIRTIO_NET_S_LINK_UP; 986 virtnet_update_status(vi); 987 netif_carrier_on(dev); 988 989 pr_debug("virtnet: registered device %s\n", dev->name); 990 return 0; 991 992 unregister: 993 unregister_netdev(dev); 994 cancel_delayed_work_sync(&vi->refill); 995 free_vqs: 996 vdev->config->del_vqs(vdev); 997 free: 998 free_netdev(dev); 999 return err; 1000 } 1001 1002 static void free_unused_bufs(struct virtnet_info *vi) 1003 { 1004 void *buf; 1005 while (1) { 1006 buf = vi->svq->vq_ops->detach_unused_buf(vi->svq); 1007 if (!buf) 1008 break; 1009 dev_kfree_skb(buf); 1010 } 1011 while (1) { 1012 buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq); 1013 if (!buf) 1014 break; 1015 if (vi->mergeable_rx_bufs || vi->big_packets) 1016 give_pages(vi, buf); 1017 else 1018 dev_kfree_skb(buf); 1019 --vi->num; 1020 } 1021 BUG_ON(vi->num != 0); 1022 } 1023 1024 static void __devexit virtnet_remove(struct virtio_device *vdev) 1025 { 1026 struct virtnet_info *vi = vdev->priv; 1027 1028 /* Stop all the virtqueues. */ 1029 vdev->config->reset(vdev); 1030 1031 1032 unregister_netdev(vi->dev); 1033 cancel_delayed_work_sync(&vi->refill); 1034 1035 /* Free unused buffers in both send and recv, if any. */ 1036 free_unused_bufs(vi); 1037 1038 vdev->config->del_vqs(vi->vdev); 1039 1040 while (vi->pages) 1041 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1042 1043 free_netdev(vi->dev); 1044 } 1045 1046 static struct virtio_device_id id_table[] = { 1047 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1048 { 0 }, 1049 }; 1050 1051 static unsigned int features[] = { 1052 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1053 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1054 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1055 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1056 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1057 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1058 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1059 }; 1060 1061 static struct virtio_driver virtio_net_driver = { 1062 .feature_table = features, 1063 .feature_table_size = ARRAY_SIZE(features), 1064 .driver.name = KBUILD_MODNAME, 1065 .driver.owner = THIS_MODULE, 1066 .id_table = id_table, 1067 .probe = virtnet_probe, 1068 .remove = __devexit_p(virtnet_remove), 1069 .config_changed = virtnet_config_changed, 1070 }; 1071 1072 static int __init init(void) 1073 { 1074 return register_virtio_driver(&virtio_net_driver); 1075 } 1076 1077 static void __exit fini(void) 1078 { 1079 unregister_virtio_driver(&virtio_net_driver); 1080 } 1081 module_init(init); 1082 module_exit(fini); 1083 1084 MODULE_DEVICE_TABLE(virtio, id_table); 1085 MODULE_DESCRIPTION("Virtio network driver"); 1086 MODULE_LICENSE("GPL"); 1087