1 /* A network driver using virtio. 2 * 3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 //#define DEBUG 20 #include <linux/netdevice.h> 21 #include <linux/etherdevice.h> 22 #include <linux/ethtool.h> 23 #include <linux/module.h> 24 #include <linux/virtio.h> 25 #include <linux/virtio_net.h> 26 #include <linux/scatterlist.h> 27 #include <linux/if_vlan.h> 28 #include <linux/slab.h> 29 30 static int napi_weight = 128; 31 module_param(napi_weight, int, 0444); 32 33 static int csum = 1, gso = 1; 34 module_param(csum, bool, 0444); 35 module_param(gso, bool, 0444); 36 37 /* FIXME: MTU in config. */ 38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 39 #define GOOD_COPY_LEN 128 40 41 #define VIRTNET_SEND_COMMAND_SG_MAX 2 42 43 struct virtnet_info 44 { 45 struct virtio_device *vdev; 46 struct virtqueue *rvq, *svq, *cvq; 47 struct net_device *dev; 48 struct napi_struct napi; 49 unsigned int status; 50 51 /* Number of input buffers, and max we've ever had. */ 52 unsigned int num, max; 53 54 /* I like... big packets and I cannot lie! */ 55 bool big_packets; 56 57 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 58 bool mergeable_rx_bufs; 59 60 /* Work struct for refilling if we run low on memory. */ 61 struct delayed_work refill; 62 63 /* Chain pages by the private ptr. */ 64 struct page *pages; 65 }; 66 67 struct skb_vnet_hdr { 68 union { 69 struct virtio_net_hdr hdr; 70 struct virtio_net_hdr_mrg_rxbuf mhdr; 71 }; 72 unsigned int num_sg; 73 }; 74 75 struct padded_vnet_hdr { 76 struct virtio_net_hdr hdr; 77 /* 78 * virtio_net_hdr should be in a separated sg buffer because of a 79 * QEMU bug, and data sg buffer shares same page with this header sg. 80 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 81 */ 82 char padding[6]; 83 }; 84 85 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 86 { 87 return (struct skb_vnet_hdr *)skb->cb; 88 } 89 90 /* 91 * private is used to chain pages for big packets, put the whole 92 * most recent used list in the beginning for reuse 93 */ 94 static void give_pages(struct virtnet_info *vi, struct page *page) 95 { 96 struct page *end; 97 98 /* Find end of list, sew whole thing into vi->pages. */ 99 for (end = page; end->private; end = (struct page *)end->private); 100 end->private = (unsigned long)vi->pages; 101 vi->pages = page; 102 } 103 104 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 105 { 106 struct page *p = vi->pages; 107 108 if (p) { 109 vi->pages = (struct page *)p->private; 110 /* clear private here, it is used to chain pages */ 111 p->private = 0; 112 } else 113 p = alloc_page(gfp_mask); 114 return p; 115 } 116 117 static void skb_xmit_done(struct virtqueue *svq) 118 { 119 struct virtnet_info *vi = svq->vdev->priv; 120 121 /* Suppress further interrupts. */ 122 svq->vq_ops->disable_cb(svq); 123 124 /* We were probably waiting for more output buffers. */ 125 netif_wake_queue(vi->dev); 126 } 127 128 static void set_skb_frag(struct sk_buff *skb, struct page *page, 129 unsigned int offset, unsigned int *len) 130 { 131 int i = skb_shinfo(skb)->nr_frags; 132 skb_frag_t *f; 133 134 f = &skb_shinfo(skb)->frags[i]; 135 f->size = min((unsigned)PAGE_SIZE - offset, *len); 136 f->page_offset = offset; 137 f->page = page; 138 139 skb->data_len += f->size; 140 skb->len += f->size; 141 skb_shinfo(skb)->nr_frags++; 142 *len -= f->size; 143 } 144 145 static struct sk_buff *page_to_skb(struct virtnet_info *vi, 146 struct page *page, unsigned int len) 147 { 148 struct sk_buff *skb; 149 struct skb_vnet_hdr *hdr; 150 unsigned int copy, hdr_len, offset; 151 char *p; 152 153 p = page_address(page); 154 155 /* copy small packet so we can reuse these pages for small data */ 156 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 157 if (unlikely(!skb)) 158 return NULL; 159 160 hdr = skb_vnet_hdr(skb); 161 162 if (vi->mergeable_rx_bufs) { 163 hdr_len = sizeof hdr->mhdr; 164 offset = hdr_len; 165 } else { 166 hdr_len = sizeof hdr->hdr; 167 offset = sizeof(struct padded_vnet_hdr); 168 } 169 170 memcpy(hdr, p, hdr_len); 171 172 len -= hdr_len; 173 p += offset; 174 175 copy = len; 176 if (copy > skb_tailroom(skb)) 177 copy = skb_tailroom(skb); 178 memcpy(skb_put(skb, copy), p, copy); 179 180 len -= copy; 181 offset += copy; 182 183 while (len) { 184 set_skb_frag(skb, page, offset, &len); 185 page = (struct page *)page->private; 186 offset = 0; 187 } 188 189 if (page) 190 give_pages(vi, page); 191 192 return skb; 193 } 194 195 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) 196 { 197 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 198 struct page *page; 199 int num_buf, i, len; 200 201 num_buf = hdr->mhdr.num_buffers; 202 while (--num_buf) { 203 i = skb_shinfo(skb)->nr_frags; 204 if (i >= MAX_SKB_FRAGS) { 205 pr_debug("%s: packet too long\n", skb->dev->name); 206 skb->dev->stats.rx_length_errors++; 207 return -EINVAL; 208 } 209 210 page = vi->rvq->vq_ops->get_buf(vi->rvq, &len); 211 if (!page) { 212 pr_debug("%s: rx error: %d buffers missing\n", 213 skb->dev->name, hdr->mhdr.num_buffers); 214 skb->dev->stats.rx_length_errors++; 215 return -EINVAL; 216 } 217 if (len > PAGE_SIZE) 218 len = PAGE_SIZE; 219 220 set_skb_frag(skb, page, 0, &len); 221 222 --vi->num; 223 } 224 return 0; 225 } 226 227 static void receive_buf(struct net_device *dev, void *buf, unsigned int len) 228 { 229 struct virtnet_info *vi = netdev_priv(dev); 230 struct sk_buff *skb; 231 struct page *page; 232 struct skb_vnet_hdr *hdr; 233 234 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 235 pr_debug("%s: short packet %i\n", dev->name, len); 236 dev->stats.rx_length_errors++; 237 if (vi->mergeable_rx_bufs || vi->big_packets) 238 give_pages(vi, buf); 239 else 240 dev_kfree_skb(buf); 241 return; 242 } 243 244 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 245 skb = buf; 246 len -= sizeof(struct virtio_net_hdr); 247 skb_trim(skb, len); 248 } else { 249 page = buf; 250 skb = page_to_skb(vi, page, len); 251 if (unlikely(!skb)) { 252 dev->stats.rx_dropped++; 253 give_pages(vi, page); 254 return; 255 } 256 if (vi->mergeable_rx_bufs) 257 if (receive_mergeable(vi, skb)) { 258 dev_kfree_skb(skb); 259 return; 260 } 261 } 262 263 hdr = skb_vnet_hdr(skb); 264 skb->truesize += skb->data_len; 265 dev->stats.rx_bytes += skb->len; 266 dev->stats.rx_packets++; 267 268 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 269 pr_debug("Needs csum!\n"); 270 if (!skb_partial_csum_set(skb, 271 hdr->hdr.csum_start, 272 hdr->hdr.csum_offset)) 273 goto frame_err; 274 } 275 276 skb->protocol = eth_type_trans(skb, dev); 277 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 278 ntohs(skb->protocol), skb->len, skb->pkt_type); 279 280 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 281 pr_debug("GSO!\n"); 282 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 283 case VIRTIO_NET_HDR_GSO_TCPV4: 284 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 285 break; 286 case VIRTIO_NET_HDR_GSO_UDP: 287 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 288 break; 289 case VIRTIO_NET_HDR_GSO_TCPV6: 290 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 291 break; 292 default: 293 if (net_ratelimit()) 294 printk(KERN_WARNING "%s: bad gso type %u.\n", 295 dev->name, hdr->hdr.gso_type); 296 goto frame_err; 297 } 298 299 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 300 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 301 302 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 303 if (skb_shinfo(skb)->gso_size == 0) { 304 if (net_ratelimit()) 305 printk(KERN_WARNING "%s: zero gso size.\n", 306 dev->name); 307 goto frame_err; 308 } 309 310 /* Header must be checked, and gso_segs computed. */ 311 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 312 skb_shinfo(skb)->gso_segs = 0; 313 } 314 315 netif_receive_skb(skb); 316 return; 317 318 frame_err: 319 dev->stats.rx_frame_errors++; 320 dev_kfree_skb(skb); 321 } 322 323 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) 324 { 325 struct sk_buff *skb; 326 struct skb_vnet_hdr *hdr; 327 struct scatterlist sg[2]; 328 int err; 329 330 sg_init_table(sg, 2); 331 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); 332 if (unlikely(!skb)) 333 return -ENOMEM; 334 335 skb_put(skb, MAX_PACKET_LEN); 336 337 hdr = skb_vnet_hdr(skb); 338 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr); 339 340 skb_to_sgvec(skb, sg + 1, 0, skb->len); 341 342 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 2, skb); 343 if (err < 0) 344 dev_kfree_skb(skb); 345 346 return err; 347 } 348 349 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 350 { 351 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 352 struct page *first, *list = NULL; 353 char *p; 354 int i, err, offset; 355 356 sg_init_table(sg, MAX_SKB_FRAGS + 2); 357 /* page in sg[MAX_SKB_FRAGS + 1] is list tail */ 358 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 359 first = get_a_page(vi, gfp); 360 if (!first) { 361 if (list) 362 give_pages(vi, list); 363 return -ENOMEM; 364 } 365 sg_set_buf(&sg[i], page_address(first), PAGE_SIZE); 366 367 /* chain new page in list head to match sg */ 368 first->private = (unsigned long)list; 369 list = first; 370 } 371 372 first = get_a_page(vi, gfp); 373 if (!first) { 374 give_pages(vi, list); 375 return -ENOMEM; 376 } 377 p = page_address(first); 378 379 /* sg[0], sg[1] share the same page */ 380 /* a separated sg[0] for virtio_net_hdr only during to QEMU bug*/ 381 sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr)); 382 383 /* sg[1] for data packet, from offset */ 384 offset = sizeof(struct padded_vnet_hdr); 385 sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset); 386 387 /* chain first in list head */ 388 first->private = (unsigned long)list; 389 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2, 390 first); 391 if (err < 0) 392 give_pages(vi, first); 393 394 return err; 395 } 396 397 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 398 { 399 struct page *page; 400 struct scatterlist sg; 401 int err; 402 403 page = get_a_page(vi, gfp); 404 if (!page) 405 return -ENOMEM; 406 407 sg_init_one(&sg, page_address(page), PAGE_SIZE); 408 409 err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page); 410 if (err < 0) 411 give_pages(vi, page); 412 413 return err; 414 } 415 416 /* Returns false if we couldn't fill entirely (OOM). */ 417 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 418 { 419 int err; 420 bool oom = false; 421 422 do { 423 if (vi->mergeable_rx_bufs) 424 err = add_recvbuf_mergeable(vi, gfp); 425 else if (vi->big_packets) 426 err = add_recvbuf_big(vi, gfp); 427 else 428 err = add_recvbuf_small(vi, gfp); 429 430 if (err < 0) { 431 oom = true; 432 break; 433 } 434 ++vi->num; 435 } while (err > 0); 436 if (unlikely(vi->num > vi->max)) 437 vi->max = vi->num; 438 vi->rvq->vq_ops->kick(vi->rvq); 439 return !oom; 440 } 441 442 static void skb_recv_done(struct virtqueue *rvq) 443 { 444 struct virtnet_info *vi = rvq->vdev->priv; 445 /* Schedule NAPI, Suppress further interrupts if successful. */ 446 if (napi_schedule_prep(&vi->napi)) { 447 rvq->vq_ops->disable_cb(rvq); 448 __napi_schedule(&vi->napi); 449 } 450 } 451 452 static void refill_work(struct work_struct *work) 453 { 454 struct virtnet_info *vi; 455 bool still_empty; 456 457 vi = container_of(work, struct virtnet_info, refill.work); 458 napi_disable(&vi->napi); 459 still_empty = !try_fill_recv(vi, GFP_KERNEL); 460 napi_enable(&vi->napi); 461 462 /* In theory, this can happen: if we don't get any buffers in 463 * we will *never* try to fill again. */ 464 if (still_empty) 465 schedule_delayed_work(&vi->refill, HZ/2); 466 } 467 468 static int virtnet_poll(struct napi_struct *napi, int budget) 469 { 470 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 471 void *buf; 472 unsigned int len, received = 0; 473 474 again: 475 while (received < budget && 476 (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) { 477 receive_buf(vi->dev, buf, len); 478 --vi->num; 479 received++; 480 } 481 482 if (vi->num < vi->max / 2) { 483 if (!try_fill_recv(vi, GFP_ATOMIC)) 484 schedule_delayed_work(&vi->refill, 0); 485 } 486 487 /* Out of packets? */ 488 if (received < budget) { 489 napi_complete(napi); 490 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) && 491 napi_schedule_prep(napi)) { 492 vi->rvq->vq_ops->disable_cb(vi->rvq); 493 __napi_schedule(napi); 494 goto again; 495 } 496 } 497 498 return received; 499 } 500 501 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) 502 { 503 struct sk_buff *skb; 504 unsigned int len, tot_sgs = 0; 505 506 while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) { 507 pr_debug("Sent skb %p\n", skb); 508 vi->dev->stats.tx_bytes += skb->len; 509 vi->dev->stats.tx_packets++; 510 tot_sgs += skb_vnet_hdr(skb)->num_sg; 511 dev_kfree_skb_any(skb); 512 } 513 return tot_sgs; 514 } 515 516 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 517 { 518 struct scatterlist sg[2+MAX_SKB_FRAGS]; 519 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 520 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 521 522 sg_init_table(sg, 2+MAX_SKB_FRAGS); 523 524 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 525 526 if (skb->ip_summed == CHECKSUM_PARTIAL) { 527 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 528 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb); 529 hdr->hdr.csum_offset = skb->csum_offset; 530 } else { 531 hdr->hdr.flags = 0; 532 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 533 } 534 535 if (skb_is_gso(skb)) { 536 hdr->hdr.hdr_len = skb_headlen(skb); 537 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 538 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 539 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 540 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 541 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 542 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 543 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 544 else 545 BUG(); 546 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 547 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 548 } else { 549 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 550 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 551 } 552 553 hdr->mhdr.num_buffers = 0; 554 555 /* Encode metadata header at front. */ 556 if (vi->mergeable_rx_bufs) 557 sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr); 558 else 559 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr); 560 561 hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; 562 return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb); 563 } 564 565 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 566 { 567 struct virtnet_info *vi = netdev_priv(dev); 568 int capacity; 569 570 again: 571 /* Free up any pending old buffers before queueing new ones. */ 572 free_old_xmit_skbs(vi); 573 574 /* Try to transmit */ 575 capacity = xmit_skb(vi, skb); 576 577 /* This can happen with OOM and indirect buffers. */ 578 if (unlikely(capacity < 0)) { 579 netif_stop_queue(dev); 580 dev_warn(&dev->dev, "Unexpected full queue\n"); 581 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { 582 vi->svq->vq_ops->disable_cb(vi->svq); 583 netif_start_queue(dev); 584 goto again; 585 } 586 return NETDEV_TX_BUSY; 587 } 588 vi->svq->vq_ops->kick(vi->svq); 589 590 /* Don't wait up for transmitted skbs to be freed. */ 591 skb_orphan(skb); 592 nf_reset(skb); 593 594 /* Apparently nice girls don't return TX_BUSY; stop the queue 595 * before it gets out of hand. Naturally, this wastes entries. */ 596 if (capacity < 2+MAX_SKB_FRAGS) { 597 netif_stop_queue(dev); 598 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { 599 /* More just got used, free them then recheck. */ 600 capacity += free_old_xmit_skbs(vi); 601 if (capacity >= 2+MAX_SKB_FRAGS) { 602 netif_start_queue(dev); 603 vi->svq->vq_ops->disable_cb(vi->svq); 604 } 605 } 606 } 607 608 return NETDEV_TX_OK; 609 } 610 611 static int virtnet_set_mac_address(struct net_device *dev, void *p) 612 { 613 struct virtnet_info *vi = netdev_priv(dev); 614 struct virtio_device *vdev = vi->vdev; 615 int ret; 616 617 ret = eth_mac_addr(dev, p); 618 if (ret) 619 return ret; 620 621 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 622 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 623 dev->dev_addr, dev->addr_len); 624 625 return 0; 626 } 627 628 #ifdef CONFIG_NET_POLL_CONTROLLER 629 static void virtnet_netpoll(struct net_device *dev) 630 { 631 struct virtnet_info *vi = netdev_priv(dev); 632 633 napi_schedule(&vi->napi); 634 } 635 #endif 636 637 static int virtnet_open(struct net_device *dev) 638 { 639 struct virtnet_info *vi = netdev_priv(dev); 640 641 napi_enable(&vi->napi); 642 643 /* If all buffers were filled by other side before we napi_enabled, we 644 * won't get another interrupt, so process any outstanding packets 645 * now. virtnet_poll wants re-enable the queue, so we disable here. 646 * We synchronize against interrupts via NAPI_STATE_SCHED */ 647 if (napi_schedule_prep(&vi->napi)) { 648 vi->rvq->vq_ops->disable_cb(vi->rvq); 649 __napi_schedule(&vi->napi); 650 } 651 return 0; 652 } 653 654 /* 655 * Send command via the control virtqueue and check status. Commands 656 * supported by the hypervisor, as indicated by feature bits, should 657 * never fail unless improperly formated. 658 */ 659 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 660 struct scatterlist *data, int out, int in) 661 { 662 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 663 struct virtio_net_ctrl_hdr ctrl; 664 virtio_net_ctrl_ack status = ~0; 665 unsigned int tmp; 666 int i; 667 668 /* Caller should know better */ 669 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 670 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 671 672 out++; /* Add header */ 673 in++; /* Add return status */ 674 675 ctrl.class = class; 676 ctrl.cmd = cmd; 677 678 sg_init_table(sg, out + in); 679 680 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 681 for_each_sg(data, s, out + in - 2, i) 682 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 683 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 684 685 BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0); 686 687 vi->cvq->vq_ops->kick(vi->cvq); 688 689 /* 690 * Spin for a response, the kick causes an ioport write, trapping 691 * into the hypervisor, so the request should be handled immediately. 692 */ 693 while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp)) 694 cpu_relax(); 695 696 return status == VIRTIO_NET_OK; 697 } 698 699 static int virtnet_close(struct net_device *dev) 700 { 701 struct virtnet_info *vi = netdev_priv(dev); 702 703 napi_disable(&vi->napi); 704 705 return 0; 706 } 707 708 static int virtnet_set_tx_csum(struct net_device *dev, u32 data) 709 { 710 struct virtnet_info *vi = netdev_priv(dev); 711 struct virtio_device *vdev = vi->vdev; 712 713 if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) 714 return -ENOSYS; 715 716 return ethtool_op_set_tx_hw_csum(dev, data); 717 } 718 719 static void virtnet_set_rx_mode(struct net_device *dev) 720 { 721 struct virtnet_info *vi = netdev_priv(dev); 722 struct scatterlist sg[2]; 723 u8 promisc, allmulti; 724 struct virtio_net_ctrl_mac *mac_data; 725 struct dev_addr_list *addr; 726 struct netdev_hw_addr *ha; 727 int uc_count; 728 int mc_count; 729 void *buf; 730 int i; 731 732 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 733 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 734 return; 735 736 promisc = ((dev->flags & IFF_PROMISC) != 0); 737 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 738 739 sg_init_one(sg, &promisc, sizeof(promisc)); 740 741 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 742 VIRTIO_NET_CTRL_RX_PROMISC, 743 sg, 1, 0)) 744 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 745 promisc ? "en" : "dis"); 746 747 sg_init_one(sg, &allmulti, sizeof(allmulti)); 748 749 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 750 VIRTIO_NET_CTRL_RX_ALLMULTI, 751 sg, 1, 0)) 752 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 753 allmulti ? "en" : "dis"); 754 755 uc_count = netdev_uc_count(dev); 756 mc_count = netdev_mc_count(dev); 757 /* MAC filter - use one buffer for both lists */ 758 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 759 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 760 mac_data = buf; 761 if (!buf) { 762 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 763 return; 764 } 765 766 sg_init_table(sg, 2); 767 768 /* Store the unicast list and count in the front of the buffer */ 769 mac_data->entries = uc_count; 770 i = 0; 771 netdev_for_each_uc_addr(ha, dev) 772 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 773 774 sg_set_buf(&sg[0], mac_data, 775 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 776 777 /* multicast list and count fill the end */ 778 mac_data = (void *)&mac_data->macs[uc_count][0]; 779 780 mac_data->entries = mc_count; 781 i = 0; 782 netdev_for_each_mc_addr(addr, dev) 783 memcpy(&mac_data->macs[i++][0], addr->da_addr, ETH_ALEN); 784 785 sg_set_buf(&sg[1], mac_data, 786 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 787 788 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 789 VIRTIO_NET_CTRL_MAC_TABLE_SET, 790 sg, 2, 0)) 791 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 792 793 kfree(buf); 794 } 795 796 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 797 { 798 struct virtnet_info *vi = netdev_priv(dev); 799 struct scatterlist sg; 800 801 sg_init_one(&sg, &vid, sizeof(vid)); 802 803 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 804 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 805 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 806 } 807 808 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 809 { 810 struct virtnet_info *vi = netdev_priv(dev); 811 struct scatterlist sg; 812 813 sg_init_one(&sg, &vid, sizeof(vid)); 814 815 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 816 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 817 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 818 } 819 820 static const struct ethtool_ops virtnet_ethtool_ops = { 821 .set_tx_csum = virtnet_set_tx_csum, 822 .set_sg = ethtool_op_set_sg, 823 .set_tso = ethtool_op_set_tso, 824 .set_ufo = ethtool_op_set_ufo, 825 .get_link = ethtool_op_get_link, 826 }; 827 828 #define MIN_MTU 68 829 #define MAX_MTU 65535 830 831 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 832 { 833 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 834 return -EINVAL; 835 dev->mtu = new_mtu; 836 return 0; 837 } 838 839 static const struct net_device_ops virtnet_netdev = { 840 .ndo_open = virtnet_open, 841 .ndo_stop = virtnet_close, 842 .ndo_start_xmit = start_xmit, 843 .ndo_validate_addr = eth_validate_addr, 844 .ndo_set_mac_address = virtnet_set_mac_address, 845 .ndo_set_rx_mode = virtnet_set_rx_mode, 846 .ndo_change_mtu = virtnet_change_mtu, 847 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 848 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 849 #ifdef CONFIG_NET_POLL_CONTROLLER 850 .ndo_poll_controller = virtnet_netpoll, 851 #endif 852 }; 853 854 static void virtnet_update_status(struct virtnet_info *vi) 855 { 856 u16 v; 857 858 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 859 return; 860 861 vi->vdev->config->get(vi->vdev, 862 offsetof(struct virtio_net_config, status), 863 &v, sizeof(v)); 864 865 /* Ignore unknown (future) status bits */ 866 v &= VIRTIO_NET_S_LINK_UP; 867 868 if (vi->status == v) 869 return; 870 871 vi->status = v; 872 873 if (vi->status & VIRTIO_NET_S_LINK_UP) { 874 netif_carrier_on(vi->dev); 875 netif_wake_queue(vi->dev); 876 } else { 877 netif_carrier_off(vi->dev); 878 netif_stop_queue(vi->dev); 879 } 880 } 881 882 static void virtnet_config_changed(struct virtio_device *vdev) 883 { 884 struct virtnet_info *vi = vdev->priv; 885 886 virtnet_update_status(vi); 887 } 888 889 static int virtnet_probe(struct virtio_device *vdev) 890 { 891 int err; 892 struct net_device *dev; 893 struct virtnet_info *vi; 894 struct virtqueue *vqs[3]; 895 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 896 const char *names[] = { "input", "output", "control" }; 897 int nvqs; 898 899 /* Allocate ourselves a network device with room for our info */ 900 dev = alloc_etherdev(sizeof(struct virtnet_info)); 901 if (!dev) 902 return -ENOMEM; 903 904 /* Set up network device as normal. */ 905 dev->netdev_ops = &virtnet_netdev; 906 dev->features = NETIF_F_HIGHDMA; 907 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 908 SET_NETDEV_DEV(dev, &vdev->dev); 909 910 /* Do we support "hardware" checksums? */ 911 if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 912 /* This opens up the world of extra features. */ 913 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 914 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 915 dev->features |= NETIF_F_TSO | NETIF_F_UFO 916 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 917 } 918 /* Individual feature bits: what can host handle? */ 919 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 920 dev->features |= NETIF_F_TSO; 921 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 922 dev->features |= NETIF_F_TSO6; 923 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 924 dev->features |= NETIF_F_TSO_ECN; 925 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 926 dev->features |= NETIF_F_UFO; 927 } 928 929 /* Configuration may specify what MAC to use. Otherwise random. */ 930 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 931 vdev->config->get(vdev, 932 offsetof(struct virtio_net_config, mac), 933 dev->dev_addr, dev->addr_len); 934 } else 935 random_ether_addr(dev->dev_addr); 936 937 /* Set up our device-specific information */ 938 vi = netdev_priv(dev); 939 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 940 vi->dev = dev; 941 vi->vdev = vdev; 942 vdev->priv = vi; 943 vi->pages = NULL; 944 INIT_DELAYED_WORK(&vi->refill, refill_work); 945 946 /* If we can receive ANY GSO packets, we must allocate large ones. */ 947 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 948 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 949 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 950 vi->big_packets = true; 951 952 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 953 vi->mergeable_rx_bufs = true; 954 955 /* We expect two virtqueues, receive then send, 956 * and optionally control. */ 957 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 958 959 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 960 if (err) 961 goto free; 962 963 vi->rvq = vqs[0]; 964 vi->svq = vqs[1]; 965 966 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 967 vi->cvq = vqs[2]; 968 969 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 970 dev->features |= NETIF_F_HW_VLAN_FILTER; 971 } 972 973 err = register_netdev(dev); 974 if (err) { 975 pr_debug("virtio_net: registering device failed\n"); 976 goto free_vqs; 977 } 978 979 /* Last of all, set up some receive buffers. */ 980 try_fill_recv(vi, GFP_KERNEL); 981 982 /* If we didn't even get one input buffer, we're useless. */ 983 if (vi->num == 0) { 984 err = -ENOMEM; 985 goto unregister; 986 } 987 988 vi->status = VIRTIO_NET_S_LINK_UP; 989 virtnet_update_status(vi); 990 netif_carrier_on(dev); 991 992 pr_debug("virtnet: registered device %s\n", dev->name); 993 return 0; 994 995 unregister: 996 unregister_netdev(dev); 997 cancel_delayed_work_sync(&vi->refill); 998 free_vqs: 999 vdev->config->del_vqs(vdev); 1000 free: 1001 free_netdev(dev); 1002 return err; 1003 } 1004 1005 static void free_unused_bufs(struct virtnet_info *vi) 1006 { 1007 void *buf; 1008 while (1) { 1009 buf = vi->svq->vq_ops->detach_unused_buf(vi->svq); 1010 if (!buf) 1011 break; 1012 dev_kfree_skb(buf); 1013 } 1014 while (1) { 1015 buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq); 1016 if (!buf) 1017 break; 1018 if (vi->mergeable_rx_bufs || vi->big_packets) 1019 give_pages(vi, buf); 1020 else 1021 dev_kfree_skb(buf); 1022 --vi->num; 1023 } 1024 BUG_ON(vi->num != 0); 1025 } 1026 1027 static void __devexit virtnet_remove(struct virtio_device *vdev) 1028 { 1029 struct virtnet_info *vi = vdev->priv; 1030 1031 /* Stop all the virtqueues. */ 1032 vdev->config->reset(vdev); 1033 1034 1035 unregister_netdev(vi->dev); 1036 cancel_delayed_work_sync(&vi->refill); 1037 1038 /* Free unused buffers in both send and recv, if any. */ 1039 free_unused_bufs(vi); 1040 1041 vdev->config->del_vqs(vi->vdev); 1042 1043 while (vi->pages) 1044 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1045 1046 free_netdev(vi->dev); 1047 } 1048 1049 static struct virtio_device_id id_table[] = { 1050 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1051 { 0 }, 1052 }; 1053 1054 static unsigned int features[] = { 1055 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1056 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1057 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1058 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1059 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1060 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1061 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1062 }; 1063 1064 static struct virtio_driver virtio_net_driver = { 1065 .feature_table = features, 1066 .feature_table_size = ARRAY_SIZE(features), 1067 .driver.name = KBUILD_MODNAME, 1068 .driver.owner = THIS_MODULE, 1069 .id_table = id_table, 1070 .probe = virtnet_probe, 1071 .remove = __devexit_p(virtnet_remove), 1072 .config_changed = virtnet_config_changed, 1073 }; 1074 1075 static int __init init(void) 1076 { 1077 return register_virtio_driver(&virtio_net_driver); 1078 } 1079 1080 static void __exit fini(void) 1081 { 1082 unregister_virtio_driver(&virtio_net_driver); 1083 } 1084 module_init(init); 1085 module_exit(fini); 1086 1087 MODULE_DEVICE_TABLE(virtio, id_table); 1088 MODULE_DESCRIPTION("Virtio network driver"); 1089 MODULE_LICENSE("GPL"); 1090