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 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 /* fragments + linear part + virtio header */ 66 struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; 67 struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; 68 }; 69 70 struct skb_vnet_hdr { 71 union { 72 struct virtio_net_hdr hdr; 73 struct virtio_net_hdr_mrg_rxbuf mhdr; 74 }; 75 unsigned int num_sg; 76 }; 77 78 struct padded_vnet_hdr { 79 struct virtio_net_hdr hdr; 80 /* 81 * virtio_net_hdr should be in a separated sg buffer because of a 82 * QEMU bug, and data sg buffer shares same page with this header sg. 83 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 84 */ 85 char padding[6]; 86 }; 87 88 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 89 { 90 return (struct skb_vnet_hdr *)skb->cb; 91 } 92 93 /* 94 * private is used to chain pages for big packets, put the whole 95 * most recent used list in the beginning for reuse 96 */ 97 static void give_pages(struct virtnet_info *vi, struct page *page) 98 { 99 struct page *end; 100 101 /* Find end of list, sew whole thing into vi->pages. */ 102 for (end = page; end->private; end = (struct page *)end->private); 103 end->private = (unsigned long)vi->pages; 104 vi->pages = page; 105 } 106 107 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 108 { 109 struct page *p = vi->pages; 110 111 if (p) { 112 vi->pages = (struct page *)p->private; 113 /* clear private here, it is used to chain pages */ 114 p->private = 0; 115 } else 116 p = alloc_page(gfp_mask); 117 return p; 118 } 119 120 static void skb_xmit_done(struct virtqueue *svq) 121 { 122 struct virtnet_info *vi = svq->vdev->priv; 123 124 /* Suppress further interrupts. */ 125 virtqueue_disable_cb(svq); 126 127 /* We were probably waiting for more output buffers. */ 128 netif_wake_queue(vi->dev); 129 } 130 131 static void set_skb_frag(struct sk_buff *skb, struct page *page, 132 unsigned int offset, unsigned int *len) 133 { 134 int i = skb_shinfo(skb)->nr_frags; 135 skb_frag_t *f; 136 137 f = &skb_shinfo(skb)->frags[i]; 138 f->size = min((unsigned)PAGE_SIZE - offset, *len); 139 f->page_offset = offset; 140 f->page = page; 141 142 skb->data_len += f->size; 143 skb->len += f->size; 144 skb_shinfo(skb)->nr_frags++; 145 *len -= f->size; 146 } 147 148 static struct sk_buff *page_to_skb(struct virtnet_info *vi, 149 struct page *page, unsigned int len) 150 { 151 struct sk_buff *skb; 152 struct skb_vnet_hdr *hdr; 153 unsigned int copy, hdr_len, offset; 154 char *p; 155 156 p = page_address(page); 157 158 /* copy small packet so we can reuse these pages for small data */ 159 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 160 if (unlikely(!skb)) 161 return NULL; 162 163 hdr = skb_vnet_hdr(skb); 164 165 if (vi->mergeable_rx_bufs) { 166 hdr_len = sizeof hdr->mhdr; 167 offset = hdr_len; 168 } else { 169 hdr_len = sizeof hdr->hdr; 170 offset = sizeof(struct padded_vnet_hdr); 171 } 172 173 memcpy(hdr, p, hdr_len); 174 175 len -= hdr_len; 176 p += offset; 177 178 copy = len; 179 if (copy > skb_tailroom(skb)) 180 copy = skb_tailroom(skb); 181 memcpy(skb_put(skb, copy), p, copy); 182 183 len -= copy; 184 offset += copy; 185 186 while (len) { 187 set_skb_frag(skb, page, offset, &len); 188 page = (struct page *)page->private; 189 offset = 0; 190 } 191 192 if (page) 193 give_pages(vi, page); 194 195 return skb; 196 } 197 198 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) 199 { 200 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 201 struct page *page; 202 int num_buf, i, len; 203 204 num_buf = hdr->mhdr.num_buffers; 205 while (--num_buf) { 206 i = skb_shinfo(skb)->nr_frags; 207 if (i >= MAX_SKB_FRAGS) { 208 pr_debug("%s: packet too long\n", skb->dev->name); 209 skb->dev->stats.rx_length_errors++; 210 return -EINVAL; 211 } 212 213 page = virtqueue_get_buf(vi->rvq, &len); 214 if (!page) { 215 pr_debug("%s: rx error: %d buffers missing\n", 216 skb->dev->name, hdr->mhdr.num_buffers); 217 skb->dev->stats.rx_length_errors++; 218 return -EINVAL; 219 } 220 if (len > PAGE_SIZE) 221 len = PAGE_SIZE; 222 223 set_skb_frag(skb, page, 0, &len); 224 225 --vi->num; 226 } 227 return 0; 228 } 229 230 static void receive_buf(struct net_device *dev, void *buf, unsigned int len) 231 { 232 struct virtnet_info *vi = netdev_priv(dev); 233 struct sk_buff *skb; 234 struct page *page; 235 struct skb_vnet_hdr *hdr; 236 237 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 238 pr_debug("%s: short packet %i\n", dev->name, len); 239 dev->stats.rx_length_errors++; 240 if (vi->mergeable_rx_bufs || vi->big_packets) 241 give_pages(vi, buf); 242 else 243 dev_kfree_skb(buf); 244 return; 245 } 246 247 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 248 skb = buf; 249 len -= sizeof(struct virtio_net_hdr); 250 skb_trim(skb, len); 251 } else { 252 page = buf; 253 skb = page_to_skb(vi, page, len); 254 if (unlikely(!skb)) { 255 dev->stats.rx_dropped++; 256 give_pages(vi, page); 257 return; 258 } 259 if (vi->mergeable_rx_bufs) 260 if (receive_mergeable(vi, skb)) { 261 dev_kfree_skb(skb); 262 return; 263 } 264 } 265 266 hdr = skb_vnet_hdr(skb); 267 skb->truesize += skb->data_len; 268 dev->stats.rx_bytes += skb->len; 269 dev->stats.rx_packets++; 270 271 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 272 pr_debug("Needs csum!\n"); 273 if (!skb_partial_csum_set(skb, 274 hdr->hdr.csum_start, 275 hdr->hdr.csum_offset)) 276 goto frame_err; 277 } 278 279 skb->protocol = eth_type_trans(skb, dev); 280 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 281 ntohs(skb->protocol), skb->len, skb->pkt_type); 282 283 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 284 pr_debug("GSO!\n"); 285 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 286 case VIRTIO_NET_HDR_GSO_TCPV4: 287 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 288 break; 289 case VIRTIO_NET_HDR_GSO_UDP: 290 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 291 break; 292 case VIRTIO_NET_HDR_GSO_TCPV6: 293 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 294 break; 295 default: 296 if (net_ratelimit()) 297 printk(KERN_WARNING "%s: bad gso type %u.\n", 298 dev->name, hdr->hdr.gso_type); 299 goto frame_err; 300 } 301 302 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 303 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 304 305 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 306 if (skb_shinfo(skb)->gso_size == 0) { 307 if (net_ratelimit()) 308 printk(KERN_WARNING "%s: zero gso size.\n", 309 dev->name); 310 goto frame_err; 311 } 312 313 /* Header must be checked, and gso_segs computed. */ 314 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 315 skb_shinfo(skb)->gso_segs = 0; 316 } 317 318 netif_receive_skb(skb); 319 return; 320 321 frame_err: 322 dev->stats.rx_frame_errors++; 323 dev_kfree_skb(skb); 324 } 325 326 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) 327 { 328 struct sk_buff *skb; 329 struct skb_vnet_hdr *hdr; 330 int err; 331 332 skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); 333 if (unlikely(!skb)) 334 return -ENOMEM; 335 336 skb_put(skb, MAX_PACKET_LEN); 337 338 hdr = skb_vnet_hdr(skb); 339 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); 340 341 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); 342 343 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); 344 if (err < 0) 345 dev_kfree_skb(skb); 346 347 return err; 348 } 349 350 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 351 { 352 struct page *first, *list = NULL; 353 char *p; 354 int i, err, offset; 355 356 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ 357 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 358 first = get_a_page(vi, gfp); 359 if (!first) { 360 if (list) 361 give_pages(vi, list); 362 return -ENOMEM; 363 } 364 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); 365 366 /* chain new page in list head to match sg */ 367 first->private = (unsigned long)list; 368 list = first; 369 } 370 371 first = get_a_page(vi, gfp); 372 if (!first) { 373 give_pages(vi, list); 374 return -ENOMEM; 375 } 376 p = page_address(first); 377 378 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ 379 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ 380 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); 381 382 /* vi->rx_sg[1] for data packet, from offset */ 383 offset = sizeof(struct padded_vnet_hdr); 384 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); 385 386 /* chain first in list head */ 387 first->private = (unsigned long)list; 388 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, 389 first, gfp); 390 if (err < 0) 391 give_pages(vi, first); 392 393 return err; 394 } 395 396 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 397 { 398 struct page *page; 399 int err; 400 401 page = get_a_page(vi, gfp); 402 if (!page) 403 return -ENOMEM; 404 405 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); 406 407 err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp); 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 virtqueue_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 virtqueue_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 = virtqueue_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(!virtqueue_enable_cb(vi->rvq)) && 489 napi_schedule_prep(napi)) { 490 virtqueue_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 = virtqueue_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 skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 517 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 518 519 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 520 521 if (skb->ip_summed == CHECKSUM_PARTIAL) { 522 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 523 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb); 524 hdr->hdr.csum_offset = skb->csum_offset; 525 } else { 526 hdr->hdr.flags = 0; 527 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 528 } 529 530 if (skb_is_gso(skb)) { 531 hdr->hdr.hdr_len = skb_headlen(skb); 532 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 533 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 534 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 535 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 536 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 537 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 538 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 539 else 540 BUG(); 541 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 542 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 543 } else { 544 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 545 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 546 } 547 548 hdr->mhdr.num_buffers = 0; 549 550 /* Encode metadata header at front. */ 551 if (vi->mergeable_rx_bufs) 552 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); 553 else 554 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); 555 556 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; 557 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, 558 0, skb); 559 } 560 561 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 562 { 563 struct virtnet_info *vi = netdev_priv(dev); 564 int capacity; 565 566 again: 567 /* Free up any pending old buffers before queueing new ones. */ 568 free_old_xmit_skbs(vi); 569 570 /* Try to transmit */ 571 capacity = xmit_skb(vi, skb); 572 573 /* This can happen with OOM and indirect buffers. */ 574 if (unlikely(capacity < 0)) { 575 netif_stop_queue(dev); 576 dev_warn(&dev->dev, "Unexpected full queue\n"); 577 if (unlikely(!virtqueue_enable_cb(vi->svq))) { 578 virtqueue_disable_cb(vi->svq); 579 netif_start_queue(dev); 580 goto again; 581 } 582 return NETDEV_TX_BUSY; 583 } 584 virtqueue_kick(vi->svq); 585 586 /* Don't wait up for transmitted skbs to be freed. */ 587 skb_orphan(skb); 588 nf_reset(skb); 589 590 /* Apparently nice girls don't return TX_BUSY; stop the queue 591 * before it gets out of hand. Naturally, this wastes entries. */ 592 if (capacity < 2+MAX_SKB_FRAGS) { 593 netif_stop_queue(dev); 594 if (unlikely(!virtqueue_enable_cb(vi->svq))) { 595 /* More just got used, free them then recheck. */ 596 capacity += free_old_xmit_skbs(vi); 597 if (capacity >= 2+MAX_SKB_FRAGS) { 598 netif_start_queue(dev); 599 virtqueue_disable_cb(vi->svq); 600 } 601 } 602 } 603 604 return NETDEV_TX_OK; 605 } 606 607 static int virtnet_set_mac_address(struct net_device *dev, void *p) 608 { 609 struct virtnet_info *vi = netdev_priv(dev); 610 struct virtio_device *vdev = vi->vdev; 611 int ret; 612 613 ret = eth_mac_addr(dev, p); 614 if (ret) 615 return ret; 616 617 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 618 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 619 dev->dev_addr, dev->addr_len); 620 621 return 0; 622 } 623 624 #ifdef CONFIG_NET_POLL_CONTROLLER 625 static void virtnet_netpoll(struct net_device *dev) 626 { 627 struct virtnet_info *vi = netdev_priv(dev); 628 629 napi_schedule(&vi->napi); 630 } 631 #endif 632 633 static int virtnet_open(struct net_device *dev) 634 { 635 struct virtnet_info *vi = netdev_priv(dev); 636 637 napi_enable(&vi->napi); 638 639 /* If all buffers were filled by other side before we napi_enabled, we 640 * won't get another interrupt, so process any outstanding packets 641 * now. virtnet_poll wants re-enable the queue, so we disable here. 642 * We synchronize against interrupts via NAPI_STATE_SCHED */ 643 if (napi_schedule_prep(&vi->napi)) { 644 virtqueue_disable_cb(vi->rvq); 645 __napi_schedule(&vi->napi); 646 } 647 return 0; 648 } 649 650 /* 651 * Send command via the control virtqueue and check status. Commands 652 * supported by the hypervisor, as indicated by feature bits, should 653 * never fail unless improperly formated. 654 */ 655 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 656 struct scatterlist *data, int out, int in) 657 { 658 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 659 struct virtio_net_ctrl_hdr ctrl; 660 virtio_net_ctrl_ack status = ~0; 661 unsigned int tmp; 662 int i; 663 664 /* Caller should know better */ 665 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 666 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 667 668 out++; /* Add header */ 669 in++; /* Add return status */ 670 671 ctrl.class = class; 672 ctrl.cmd = cmd; 673 674 sg_init_table(sg, out + in); 675 676 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 677 for_each_sg(data, s, out + in - 2, i) 678 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 679 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 680 681 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0); 682 683 virtqueue_kick(vi->cvq); 684 685 /* 686 * Spin for a response, the kick causes an ioport write, trapping 687 * into the hypervisor, so the request should be handled immediately. 688 */ 689 while (!virtqueue_get_buf(vi->cvq, &tmp)) 690 cpu_relax(); 691 692 return status == VIRTIO_NET_OK; 693 } 694 695 static int virtnet_close(struct net_device *dev) 696 { 697 struct virtnet_info *vi = netdev_priv(dev); 698 699 napi_disable(&vi->napi); 700 701 return 0; 702 } 703 704 static int virtnet_set_tx_csum(struct net_device *dev, u32 data) 705 { 706 struct virtnet_info *vi = netdev_priv(dev); 707 struct virtio_device *vdev = vi->vdev; 708 709 if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) 710 return -ENOSYS; 711 712 return ethtool_op_set_tx_hw_csum(dev, data); 713 } 714 715 static void virtnet_set_rx_mode(struct net_device *dev) 716 { 717 struct virtnet_info *vi = netdev_priv(dev); 718 struct scatterlist sg[2]; 719 u8 promisc, allmulti; 720 struct virtio_net_ctrl_mac *mac_data; 721 struct netdev_hw_addr *ha; 722 int uc_count; 723 int mc_count; 724 void *buf; 725 int i; 726 727 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 728 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 729 return; 730 731 promisc = ((dev->flags & IFF_PROMISC) != 0); 732 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 733 734 sg_init_one(sg, &promisc, sizeof(promisc)); 735 736 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 737 VIRTIO_NET_CTRL_RX_PROMISC, 738 sg, 1, 0)) 739 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 740 promisc ? "en" : "dis"); 741 742 sg_init_one(sg, &allmulti, sizeof(allmulti)); 743 744 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 745 VIRTIO_NET_CTRL_RX_ALLMULTI, 746 sg, 1, 0)) 747 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 748 allmulti ? "en" : "dis"); 749 750 uc_count = netdev_uc_count(dev); 751 mc_count = netdev_mc_count(dev); 752 /* MAC filter - use one buffer for both lists */ 753 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 754 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 755 mac_data = buf; 756 if (!buf) { 757 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 758 return; 759 } 760 761 sg_init_table(sg, 2); 762 763 /* Store the unicast list and count in the front of the buffer */ 764 mac_data->entries = uc_count; 765 i = 0; 766 netdev_for_each_uc_addr(ha, dev) 767 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 768 769 sg_set_buf(&sg[0], mac_data, 770 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 771 772 /* multicast list and count fill the end */ 773 mac_data = (void *)&mac_data->macs[uc_count][0]; 774 775 mac_data->entries = mc_count; 776 i = 0; 777 netdev_for_each_mc_addr(ha, dev) 778 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 779 780 sg_set_buf(&sg[1], mac_data, 781 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 782 783 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 784 VIRTIO_NET_CTRL_MAC_TABLE_SET, 785 sg, 2, 0)) 786 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 787 788 kfree(buf); 789 } 790 791 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 792 { 793 struct virtnet_info *vi = netdev_priv(dev); 794 struct scatterlist sg; 795 796 sg_init_one(&sg, &vid, sizeof(vid)); 797 798 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 799 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 800 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 801 } 802 803 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 804 { 805 struct virtnet_info *vi = netdev_priv(dev); 806 struct scatterlist sg; 807 808 sg_init_one(&sg, &vid, sizeof(vid)); 809 810 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 811 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 812 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 813 } 814 815 static const struct ethtool_ops virtnet_ethtool_ops = { 816 .set_tx_csum = virtnet_set_tx_csum, 817 .set_sg = ethtool_op_set_sg, 818 .set_tso = ethtool_op_set_tso, 819 .set_ufo = ethtool_op_set_ufo, 820 .get_link = ethtool_op_get_link, 821 }; 822 823 #define MIN_MTU 68 824 #define MAX_MTU 65535 825 826 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 827 { 828 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 829 return -EINVAL; 830 dev->mtu = new_mtu; 831 return 0; 832 } 833 834 static const struct net_device_ops virtnet_netdev = { 835 .ndo_open = virtnet_open, 836 .ndo_stop = virtnet_close, 837 .ndo_start_xmit = start_xmit, 838 .ndo_validate_addr = eth_validate_addr, 839 .ndo_set_mac_address = virtnet_set_mac_address, 840 .ndo_set_rx_mode = virtnet_set_rx_mode, 841 .ndo_change_mtu = virtnet_change_mtu, 842 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 843 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 844 #ifdef CONFIG_NET_POLL_CONTROLLER 845 .ndo_poll_controller = virtnet_netpoll, 846 #endif 847 }; 848 849 static void virtnet_update_status(struct virtnet_info *vi) 850 { 851 u16 v; 852 853 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 854 return; 855 856 vi->vdev->config->get(vi->vdev, 857 offsetof(struct virtio_net_config, status), 858 &v, sizeof(v)); 859 860 /* Ignore unknown (future) status bits */ 861 v &= VIRTIO_NET_S_LINK_UP; 862 863 if (vi->status == v) 864 return; 865 866 vi->status = v; 867 868 if (vi->status & VIRTIO_NET_S_LINK_UP) { 869 netif_carrier_on(vi->dev); 870 netif_wake_queue(vi->dev); 871 } else { 872 netif_carrier_off(vi->dev); 873 netif_stop_queue(vi->dev); 874 } 875 } 876 877 static void virtnet_config_changed(struct virtio_device *vdev) 878 { 879 struct virtnet_info *vi = vdev->priv; 880 881 virtnet_update_status(vi); 882 } 883 884 static int virtnet_probe(struct virtio_device *vdev) 885 { 886 int err; 887 struct net_device *dev; 888 struct virtnet_info *vi; 889 struct virtqueue *vqs[3]; 890 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 891 const char *names[] = { "input", "output", "control" }; 892 int nvqs; 893 894 /* Allocate ourselves a network device with room for our info */ 895 dev = alloc_etherdev(sizeof(struct virtnet_info)); 896 if (!dev) 897 return -ENOMEM; 898 899 /* Set up network device as normal. */ 900 dev->netdev_ops = &virtnet_netdev; 901 dev->features = NETIF_F_HIGHDMA; 902 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 903 SET_NETDEV_DEV(dev, &vdev->dev); 904 905 /* Do we support "hardware" checksums? */ 906 if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 907 /* This opens up the world of extra features. */ 908 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 909 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 910 dev->features |= NETIF_F_TSO | NETIF_F_UFO 911 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 912 } 913 /* Individual feature bits: what can host handle? */ 914 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 915 dev->features |= NETIF_F_TSO; 916 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 917 dev->features |= NETIF_F_TSO6; 918 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 919 dev->features |= NETIF_F_TSO_ECN; 920 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 921 dev->features |= NETIF_F_UFO; 922 } 923 924 /* Configuration may specify what MAC to use. Otherwise random. */ 925 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 926 vdev->config->get(vdev, 927 offsetof(struct virtio_net_config, mac), 928 dev->dev_addr, dev->addr_len); 929 } else 930 random_ether_addr(dev->dev_addr); 931 932 /* Set up our device-specific information */ 933 vi = netdev_priv(dev); 934 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 935 vi->dev = dev; 936 vi->vdev = vdev; 937 vdev->priv = vi; 938 vi->pages = NULL; 939 INIT_DELAYED_WORK(&vi->refill, refill_work); 940 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); 941 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); 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 = virtqueue_detach_unused_buf(vi->svq); 1007 if (!buf) 1008 break; 1009 dev_kfree_skb(buf); 1010 } 1011 while (1) { 1012 buf = virtqueue_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