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 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); 331 if (unlikely(!skb)) 332 return -ENOMEM; 333 334 skb_put(skb, MAX_PACKET_LEN); 335 336 hdr = skb_vnet_hdr(skb); 337 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr); 338 339 skb_to_sgvec(skb, sg + 1, 0, skb->len); 340 341 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 2, skb); 342 if (err < 0) 343 dev_kfree_skb(skb); 344 345 return err; 346 } 347 348 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 349 { 350 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 351 struct page *first, *list = NULL; 352 char *p; 353 int i, err, offset; 354 355 /* page in sg[MAX_SKB_FRAGS + 1] is list tail */ 356 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 357 first = get_a_page(vi, gfp); 358 if (!first) { 359 if (list) 360 give_pages(vi, list); 361 return -ENOMEM; 362 } 363 sg_set_buf(&sg[i], page_address(first), PAGE_SIZE); 364 365 /* chain new page in list head to match sg */ 366 first->private = (unsigned long)list; 367 list = first; 368 } 369 370 first = get_a_page(vi, gfp); 371 if (!first) { 372 give_pages(vi, list); 373 return -ENOMEM; 374 } 375 p = page_address(first); 376 377 /* sg[0], sg[1] share the same page */ 378 /* a separated sg[0] for virtio_net_hdr only during to QEMU bug*/ 379 sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr)); 380 381 /* sg[1] for data packet, from offset */ 382 offset = sizeof(struct padded_vnet_hdr); 383 sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset); 384 385 /* chain first in list head */ 386 first->private = (unsigned long)list; 387 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2, 388 first); 389 if (err < 0) 390 give_pages(vi, first); 391 392 return err; 393 } 394 395 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 396 { 397 struct page *page; 398 struct scatterlist sg; 399 int err; 400 401 page = get_a_page(vi, gfp); 402 if (!page) 403 return -ENOMEM; 404 405 sg_init_one(&sg, page_address(page), PAGE_SIZE); 406 407 err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page); 408 if (err < 0) 409 give_pages(vi, page); 410 411 return err; 412 } 413 414 /* Returns false if we couldn't fill entirely (OOM). */ 415 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 416 { 417 int err; 418 bool oom = false; 419 420 do { 421 if (vi->mergeable_rx_bufs) 422 err = add_recvbuf_mergeable(vi, gfp); 423 else if (vi->big_packets) 424 err = add_recvbuf_big(vi, gfp); 425 else 426 err = add_recvbuf_small(vi, gfp); 427 428 if (err < 0) { 429 oom = true; 430 break; 431 } 432 ++vi->num; 433 } while (err > 0); 434 if (unlikely(vi->num > vi->max)) 435 vi->max = vi->num; 436 vi->rvq->vq_ops->kick(vi->rvq); 437 return !oom; 438 } 439 440 static void skb_recv_done(struct virtqueue *rvq) 441 { 442 struct virtnet_info *vi = rvq->vdev->priv; 443 /* Schedule NAPI, Suppress further interrupts if successful. */ 444 if (napi_schedule_prep(&vi->napi)) { 445 rvq->vq_ops->disable_cb(rvq); 446 __napi_schedule(&vi->napi); 447 } 448 } 449 450 static void refill_work(struct work_struct *work) 451 { 452 struct virtnet_info *vi; 453 bool still_empty; 454 455 vi = container_of(work, struct virtnet_info, refill.work); 456 napi_disable(&vi->napi); 457 still_empty = !try_fill_recv(vi, GFP_KERNEL); 458 napi_enable(&vi->napi); 459 460 /* In theory, this can happen: if we don't get any buffers in 461 * we will *never* try to fill again. */ 462 if (still_empty) 463 schedule_delayed_work(&vi->refill, HZ/2); 464 } 465 466 static int virtnet_poll(struct napi_struct *napi, int budget) 467 { 468 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 469 void *buf; 470 unsigned int len, received = 0; 471 472 again: 473 while (received < budget && 474 (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) { 475 receive_buf(vi->dev, buf, len); 476 --vi->num; 477 received++; 478 } 479 480 if (vi->num < vi->max / 2) { 481 if (!try_fill_recv(vi, GFP_ATOMIC)) 482 schedule_delayed_work(&vi->refill, 0); 483 } 484 485 /* Out of packets? */ 486 if (received < budget) { 487 napi_complete(napi); 488 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) && 489 napi_schedule_prep(napi)) { 490 vi->rvq->vq_ops->disable_cb(vi->rvq); 491 __napi_schedule(napi); 492 goto again; 493 } 494 } 495 496 return received; 497 } 498 499 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) 500 { 501 struct sk_buff *skb; 502 unsigned int len, tot_sgs = 0; 503 504 while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) { 505 pr_debug("Sent skb %p\n", skb); 506 vi->dev->stats.tx_bytes += skb->len; 507 vi->dev->stats.tx_packets++; 508 tot_sgs += skb_vnet_hdr(skb)->num_sg; 509 dev_kfree_skb_any(skb); 510 } 511 return tot_sgs; 512 } 513 514 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 515 { 516 struct scatterlist sg[2+MAX_SKB_FRAGS]; 517 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 518 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 519 520 sg_init_table(sg, 2+MAX_SKB_FRAGS); 521 522 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 523 524 if (skb->ip_summed == CHECKSUM_PARTIAL) { 525 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 526 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb); 527 hdr->hdr.csum_offset = skb->csum_offset; 528 } else { 529 hdr->hdr.flags = 0; 530 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 531 } 532 533 if (skb_is_gso(skb)) { 534 hdr->hdr.hdr_len = skb_headlen(skb); 535 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 536 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 537 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 538 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 539 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 540 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 541 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 542 else 543 BUG(); 544 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 545 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 546 } else { 547 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 548 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 549 } 550 551 hdr->mhdr.num_buffers = 0; 552 553 /* Encode metadata header at front. */ 554 if (vi->mergeable_rx_bufs) 555 sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr); 556 else 557 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr); 558 559 hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; 560 return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb); 561 } 562 563 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 564 { 565 struct virtnet_info *vi = netdev_priv(dev); 566 int capacity; 567 568 again: 569 /* Free up any pending old buffers before queueing new ones. */ 570 free_old_xmit_skbs(vi); 571 572 /* Try to transmit */ 573 capacity = xmit_skb(vi, skb); 574 575 /* This can happen with OOM and indirect buffers. */ 576 if (unlikely(capacity < 0)) { 577 netif_stop_queue(dev); 578 dev_warn(&dev->dev, "Unexpected full queue\n"); 579 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { 580 vi->svq->vq_ops->disable_cb(vi->svq); 581 netif_start_queue(dev); 582 goto again; 583 } 584 return NETDEV_TX_BUSY; 585 } 586 vi->svq->vq_ops->kick(vi->svq); 587 588 /* Don't wait up for transmitted skbs to be freed. */ 589 skb_orphan(skb); 590 nf_reset(skb); 591 592 /* Apparently nice girls don't return TX_BUSY; stop the queue 593 * before it gets out of hand. Naturally, this wastes entries. */ 594 if (capacity < 2+MAX_SKB_FRAGS) { 595 netif_stop_queue(dev); 596 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { 597 /* More just got used, free them then recheck. */ 598 capacity += free_old_xmit_skbs(vi); 599 if (capacity >= 2+MAX_SKB_FRAGS) { 600 netif_start_queue(dev); 601 vi->svq->vq_ops->disable_cb(vi->svq); 602 } 603 } 604 } 605 606 return NETDEV_TX_OK; 607 } 608 609 static int virtnet_set_mac_address(struct net_device *dev, void *p) 610 { 611 struct virtnet_info *vi = netdev_priv(dev); 612 struct virtio_device *vdev = vi->vdev; 613 int ret; 614 615 ret = eth_mac_addr(dev, p); 616 if (ret) 617 return ret; 618 619 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 620 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 621 dev->dev_addr, dev->addr_len); 622 623 return 0; 624 } 625 626 #ifdef CONFIG_NET_POLL_CONTROLLER 627 static void virtnet_netpoll(struct net_device *dev) 628 { 629 struct virtnet_info *vi = netdev_priv(dev); 630 631 napi_schedule(&vi->napi); 632 } 633 #endif 634 635 static int virtnet_open(struct net_device *dev) 636 { 637 struct virtnet_info *vi = netdev_priv(dev); 638 639 napi_enable(&vi->napi); 640 641 /* If all buffers were filled by other side before we napi_enabled, we 642 * won't get another interrupt, so process any outstanding packets 643 * now. virtnet_poll wants re-enable the queue, so we disable here. 644 * We synchronize against interrupts via NAPI_STATE_SCHED */ 645 if (napi_schedule_prep(&vi->napi)) { 646 vi->rvq->vq_ops->disable_cb(vi->rvq); 647 __napi_schedule(&vi->napi); 648 } 649 return 0; 650 } 651 652 /* 653 * Send command via the control virtqueue and check status. Commands 654 * supported by the hypervisor, as indicated by feature bits, should 655 * never fail unless improperly formated. 656 */ 657 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 658 struct scatterlist *data, int out, int in) 659 { 660 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 661 struct virtio_net_ctrl_hdr ctrl; 662 virtio_net_ctrl_ack status = ~0; 663 unsigned int tmp; 664 int i; 665 666 /* Caller should know better */ 667 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 668 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 669 670 out++; /* Add header */ 671 in++; /* Add return status */ 672 673 ctrl.class = class; 674 ctrl.cmd = cmd; 675 676 sg_init_table(sg, out + in); 677 678 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 679 for_each_sg(data, s, out + in - 2, i) 680 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 681 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 682 683 BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0); 684 685 vi->cvq->vq_ops->kick(vi->cvq); 686 687 /* 688 * Spin for a response, the kick causes an ioport write, trapping 689 * into the hypervisor, so the request should be handled immediately. 690 */ 691 while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp)) 692 cpu_relax(); 693 694 return status == VIRTIO_NET_OK; 695 } 696 697 static int virtnet_close(struct net_device *dev) 698 { 699 struct virtnet_info *vi = netdev_priv(dev); 700 701 napi_disable(&vi->napi); 702 703 return 0; 704 } 705 706 static int virtnet_set_tx_csum(struct net_device *dev, u32 data) 707 { 708 struct virtnet_info *vi = netdev_priv(dev); 709 struct virtio_device *vdev = vi->vdev; 710 711 if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) 712 return -ENOSYS; 713 714 return ethtool_op_set_tx_hw_csum(dev, data); 715 } 716 717 static void virtnet_set_rx_mode(struct net_device *dev) 718 { 719 struct virtnet_info *vi = netdev_priv(dev); 720 struct scatterlist sg[2]; 721 u8 promisc, allmulti; 722 struct virtio_net_ctrl_mac *mac_data; 723 struct dev_addr_list *addr; 724 struct netdev_hw_addr *ha; 725 int uc_count; 726 int mc_count; 727 void *buf; 728 int i; 729 730 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 731 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 732 return; 733 734 promisc = ((dev->flags & IFF_PROMISC) != 0); 735 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 736 737 sg_init_one(sg, &promisc, sizeof(promisc)); 738 739 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 740 VIRTIO_NET_CTRL_RX_PROMISC, 741 sg, 1, 0)) 742 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 743 promisc ? "en" : "dis"); 744 745 sg_init_one(sg, &allmulti, sizeof(allmulti)); 746 747 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 748 VIRTIO_NET_CTRL_RX_ALLMULTI, 749 sg, 1, 0)) 750 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 751 allmulti ? "en" : "dis"); 752 753 uc_count = netdev_uc_count(dev); 754 mc_count = netdev_mc_count(dev); 755 /* MAC filter - use one buffer for both lists */ 756 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 757 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 758 mac_data = buf; 759 if (!buf) { 760 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 761 return; 762 } 763 764 sg_init_table(sg, 2); 765 766 /* Store the unicast list and count in the front of the buffer */ 767 mac_data->entries = uc_count; 768 i = 0; 769 netdev_for_each_uc_addr(ha, dev) 770 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 771 772 sg_set_buf(&sg[0], mac_data, 773 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 774 775 /* multicast list and count fill the end */ 776 mac_data = (void *)&mac_data->macs[uc_count][0]; 777 778 mac_data->entries = mc_count; 779 i = 0; 780 netdev_for_each_mc_addr(addr, dev) 781 memcpy(&mac_data->macs[i++][0], addr->da_addr, ETH_ALEN); 782 783 sg_set_buf(&sg[1], mac_data, 784 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 785 786 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 787 VIRTIO_NET_CTRL_MAC_TABLE_SET, 788 sg, 2, 0)) 789 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 790 791 kfree(buf); 792 } 793 794 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 795 { 796 struct virtnet_info *vi = netdev_priv(dev); 797 struct scatterlist sg; 798 799 sg_init_one(&sg, &vid, sizeof(vid)); 800 801 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 802 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 803 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 804 } 805 806 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 807 { 808 struct virtnet_info *vi = netdev_priv(dev); 809 struct scatterlist sg; 810 811 sg_init_one(&sg, &vid, sizeof(vid)); 812 813 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 814 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 815 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 816 } 817 818 static const struct ethtool_ops virtnet_ethtool_ops = { 819 .set_tx_csum = virtnet_set_tx_csum, 820 .set_sg = ethtool_op_set_sg, 821 .set_tso = ethtool_op_set_tso, 822 .set_ufo = ethtool_op_set_ufo, 823 .get_link = ethtool_op_get_link, 824 }; 825 826 #define MIN_MTU 68 827 #define MAX_MTU 65535 828 829 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 830 { 831 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 832 return -EINVAL; 833 dev->mtu = new_mtu; 834 return 0; 835 } 836 837 static const struct net_device_ops virtnet_netdev = { 838 .ndo_open = virtnet_open, 839 .ndo_stop = virtnet_close, 840 .ndo_start_xmit = start_xmit, 841 .ndo_validate_addr = eth_validate_addr, 842 .ndo_set_mac_address = virtnet_set_mac_address, 843 .ndo_set_rx_mode = virtnet_set_rx_mode, 844 .ndo_change_mtu = virtnet_change_mtu, 845 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 846 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 847 #ifdef CONFIG_NET_POLL_CONTROLLER 848 .ndo_poll_controller = virtnet_netpoll, 849 #endif 850 }; 851 852 static void virtnet_update_status(struct virtnet_info *vi) 853 { 854 u16 v; 855 856 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 857 return; 858 859 vi->vdev->config->get(vi->vdev, 860 offsetof(struct virtio_net_config, status), 861 &v, sizeof(v)); 862 863 /* Ignore unknown (future) status bits */ 864 v &= VIRTIO_NET_S_LINK_UP; 865 866 if (vi->status == v) 867 return; 868 869 vi->status = v; 870 871 if (vi->status & VIRTIO_NET_S_LINK_UP) { 872 netif_carrier_on(vi->dev); 873 netif_wake_queue(vi->dev); 874 } else { 875 netif_carrier_off(vi->dev); 876 netif_stop_queue(vi->dev); 877 } 878 } 879 880 static void virtnet_config_changed(struct virtio_device *vdev) 881 { 882 struct virtnet_info *vi = vdev->priv; 883 884 virtnet_update_status(vi); 885 } 886 887 static int virtnet_probe(struct virtio_device *vdev) 888 { 889 int err; 890 struct net_device *dev; 891 struct virtnet_info *vi; 892 struct virtqueue *vqs[3]; 893 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 894 const char *names[] = { "input", "output", "control" }; 895 int nvqs; 896 897 /* Allocate ourselves a network device with room for our info */ 898 dev = alloc_etherdev(sizeof(struct virtnet_info)); 899 if (!dev) 900 return -ENOMEM; 901 902 /* Set up network device as normal. */ 903 dev->netdev_ops = &virtnet_netdev; 904 dev->features = NETIF_F_HIGHDMA; 905 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 906 SET_NETDEV_DEV(dev, &vdev->dev); 907 908 /* Do we support "hardware" checksums? */ 909 if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 910 /* This opens up the world of extra features. */ 911 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 912 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 913 dev->features |= NETIF_F_TSO | NETIF_F_UFO 914 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 915 } 916 /* Individual feature bits: what can host handle? */ 917 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 918 dev->features |= NETIF_F_TSO; 919 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 920 dev->features |= NETIF_F_TSO6; 921 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 922 dev->features |= NETIF_F_TSO_ECN; 923 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 924 dev->features |= NETIF_F_UFO; 925 } 926 927 /* Configuration may specify what MAC to use. Otherwise random. */ 928 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 929 vdev->config->get(vdev, 930 offsetof(struct virtio_net_config, mac), 931 dev->dev_addr, dev->addr_len); 932 } else 933 random_ether_addr(dev->dev_addr); 934 935 /* Set up our device-specific information */ 936 vi = netdev_priv(dev); 937 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 938 vi->dev = dev; 939 vi->vdev = vdev; 940 vdev->priv = vi; 941 vi->pages = NULL; 942 INIT_DELAYED_WORK(&vi->refill, refill_work); 943 944 /* If we can receive ANY GSO packets, we must allocate large ones. */ 945 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 946 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 947 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 948 vi->big_packets = true; 949 950 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 951 vi->mergeable_rx_bufs = true; 952 953 /* We expect two virtqueues, receive then send, 954 * and optionally control. */ 955 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 956 957 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 958 if (err) 959 goto free; 960 961 vi->rvq = vqs[0]; 962 vi->svq = vqs[1]; 963 964 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 965 vi->cvq = vqs[2]; 966 967 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 968 dev->features |= NETIF_F_HW_VLAN_FILTER; 969 } 970 971 err = register_netdev(dev); 972 if (err) { 973 pr_debug("virtio_net: registering device failed\n"); 974 goto free_vqs; 975 } 976 977 /* Last of all, set up some receive buffers. */ 978 try_fill_recv(vi, GFP_KERNEL); 979 980 /* If we didn't even get one input buffer, we're useless. */ 981 if (vi->num == 0) { 982 err = -ENOMEM; 983 goto unregister; 984 } 985 986 vi->status = VIRTIO_NET_S_LINK_UP; 987 virtnet_update_status(vi); 988 netif_carrier_on(dev); 989 990 pr_debug("virtnet: registered device %s\n", dev->name); 991 return 0; 992 993 unregister: 994 unregister_netdev(dev); 995 cancel_delayed_work_sync(&vi->refill); 996 free_vqs: 997 vdev->config->del_vqs(vdev); 998 free: 999 free_netdev(dev); 1000 return err; 1001 } 1002 1003 static void free_unused_bufs(struct virtnet_info *vi) 1004 { 1005 void *buf; 1006 while (1) { 1007 buf = vi->svq->vq_ops->detach_unused_buf(vi->svq); 1008 if (!buf) 1009 break; 1010 dev_kfree_skb(buf); 1011 } 1012 while (1) { 1013 buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq); 1014 if (!buf) 1015 break; 1016 if (vi->mergeable_rx_bufs || vi->big_packets) 1017 give_pages(vi, buf); 1018 else 1019 dev_kfree_skb(buf); 1020 --vi->num; 1021 } 1022 BUG_ON(vi->num != 0); 1023 } 1024 1025 static void __devexit virtnet_remove(struct virtio_device *vdev) 1026 { 1027 struct virtnet_info *vi = vdev->priv; 1028 1029 /* Stop all the virtqueues. */ 1030 vdev->config->reset(vdev); 1031 1032 1033 unregister_netdev(vi->dev); 1034 cancel_delayed_work_sync(&vi->refill); 1035 1036 /* Free unused buffers in both send and recv, if any. */ 1037 free_unused_bufs(vi); 1038 1039 vdev->config->del_vqs(vi->vdev); 1040 1041 while (vi->pages) 1042 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1043 1044 free_netdev(vi->dev); 1045 } 1046 1047 static struct virtio_device_id id_table[] = { 1048 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1049 { 0 }, 1050 }; 1051 1052 static unsigned int features[] = { 1053 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1054 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1055 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1056 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1057 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1058 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1059 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1060 }; 1061 1062 static struct virtio_driver virtio_net_driver = { 1063 .feature_table = features, 1064 .feature_table_size = ARRAY_SIZE(features), 1065 .driver.name = KBUILD_MODNAME, 1066 .driver.owner = THIS_MODULE, 1067 .id_table = id_table, 1068 .probe = virtnet_probe, 1069 .remove = __devexit_p(virtnet_remove), 1070 .config_changed = virtnet_config_changed, 1071 }; 1072 1073 static int __init init(void) 1074 { 1075 return register_virtio_driver(&virtio_net_driver); 1076 } 1077 1078 static void __exit fini(void) 1079 { 1080 unregister_virtio_driver(&virtio_net_driver); 1081 } 1082 module_init(init); 1083 module_exit(fini); 1084 1085 MODULE_DEVICE_TABLE(virtio, id_table); 1086 MODULE_DESCRIPTION("Virtio network driver"); 1087 MODULE_LICENSE("GPL"); 1088