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; 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 oom = err == -ENOMEM; 429 if (err < 0) 430 break; 431 ++vi->num; 432 } while (err > 0); 433 if (unlikely(vi->num > vi->max)) 434 vi->max = vi->num; 435 virtqueue_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 virtqueue_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 = virtqueue_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(!virtqueue_enable_cb(vi->rvq)) && 488 napi_schedule_prep(napi)) { 489 virtqueue_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 = virtqueue_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 skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 516 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 517 518 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 519 520 if (skb->ip_summed == CHECKSUM_PARTIAL) { 521 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 522 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb); 523 hdr->hdr.csum_offset = skb->csum_offset; 524 } else { 525 hdr->hdr.flags = 0; 526 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 527 } 528 529 if (skb_is_gso(skb)) { 530 hdr->hdr.hdr_len = skb_headlen(skb); 531 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 532 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 533 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 534 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 535 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 536 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 537 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 538 else 539 BUG(); 540 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 541 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 542 } else { 543 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 544 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 545 } 546 547 hdr->mhdr.num_buffers = 0; 548 549 /* Encode metadata header at front. */ 550 if (vi->mergeable_rx_bufs) 551 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); 552 else 553 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); 554 555 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; 556 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, 557 0, skb); 558 } 559 560 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 561 { 562 struct virtnet_info *vi = netdev_priv(dev); 563 int capacity; 564 565 /* Free up any pending old buffers before queueing new ones. */ 566 free_old_xmit_skbs(vi); 567 568 /* Try to transmit */ 569 capacity = xmit_skb(vi, skb); 570 571 /* This can happen with OOM and indirect buffers. */ 572 if (unlikely(capacity < 0)) { 573 if (net_ratelimit()) { 574 if (likely(capacity == -ENOMEM)) { 575 dev_warn(&dev->dev, 576 "TX queue failure: out of memory\n"); 577 } else { 578 dev->stats.tx_fifo_errors++; 579 dev_warn(&dev->dev, 580 "Unexpected TX queue failure: %d\n", 581 capacity); 582 } 583 } 584 dev->stats.tx_dropped++; 585 kfree_skb(skb); 586 return NETDEV_TX_OK; 587 } 588 virtqueue_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(!virtqueue_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 virtqueue_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 virtqueue_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(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0); 686 687 virtqueue_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 (!virtqueue_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 netdev_hw_addr *ha; 726 int uc_count; 727 int mc_count; 728 void *buf; 729 int i; 730 731 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 732 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 733 return; 734 735 promisc = ((dev->flags & IFF_PROMISC) != 0); 736 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 737 738 sg_init_one(sg, &promisc, sizeof(promisc)); 739 740 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 741 VIRTIO_NET_CTRL_RX_PROMISC, 742 sg, 1, 0)) 743 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 744 promisc ? "en" : "dis"); 745 746 sg_init_one(sg, &allmulti, sizeof(allmulti)); 747 748 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 749 VIRTIO_NET_CTRL_RX_ALLMULTI, 750 sg, 1, 0)) 751 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 752 allmulti ? "en" : "dis"); 753 754 uc_count = netdev_uc_count(dev); 755 mc_count = netdev_mc_count(dev); 756 /* MAC filter - use one buffer for both lists */ 757 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 758 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 759 mac_data = buf; 760 if (!buf) { 761 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 762 return; 763 } 764 765 sg_init_table(sg, 2); 766 767 /* Store the unicast list and count in the front of the buffer */ 768 mac_data->entries = uc_count; 769 i = 0; 770 netdev_for_each_uc_addr(ha, dev) 771 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 772 773 sg_set_buf(&sg[0], mac_data, 774 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 775 776 /* multicast list and count fill the end */ 777 mac_data = (void *)&mac_data->macs[uc_count][0]; 778 779 mac_data->entries = mc_count; 780 i = 0; 781 netdev_for_each_mc_addr(ha, dev) 782 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 783 784 sg_set_buf(&sg[1], mac_data, 785 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 786 787 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 788 VIRTIO_NET_CTRL_MAC_TABLE_SET, 789 sg, 2, 0)) 790 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 791 792 kfree(buf); 793 } 794 795 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 796 { 797 struct virtnet_info *vi = netdev_priv(dev); 798 struct scatterlist sg; 799 800 sg_init_one(&sg, &vid, sizeof(vid)); 801 802 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 803 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 804 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 805 } 806 807 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 808 { 809 struct virtnet_info *vi = netdev_priv(dev); 810 struct scatterlist sg; 811 812 sg_init_one(&sg, &vid, sizeof(vid)); 813 814 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 815 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 816 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 817 } 818 819 static const struct ethtool_ops virtnet_ethtool_ops = { 820 .set_tx_csum = virtnet_set_tx_csum, 821 .set_sg = ethtool_op_set_sg, 822 .set_tso = ethtool_op_set_tso, 823 .set_ufo = ethtool_op_set_ufo, 824 .get_link = ethtool_op_get_link, 825 }; 826 827 #define MIN_MTU 68 828 #define MAX_MTU 65535 829 830 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 831 { 832 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 833 return -EINVAL; 834 dev->mtu = new_mtu; 835 return 0; 836 } 837 838 static const struct net_device_ops virtnet_netdev = { 839 .ndo_open = virtnet_open, 840 .ndo_stop = virtnet_close, 841 .ndo_start_xmit = start_xmit, 842 .ndo_validate_addr = eth_validate_addr, 843 .ndo_set_mac_address = virtnet_set_mac_address, 844 .ndo_set_rx_mode = virtnet_set_rx_mode, 845 .ndo_change_mtu = virtnet_change_mtu, 846 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 847 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 848 #ifdef CONFIG_NET_POLL_CONTROLLER 849 .ndo_poll_controller = virtnet_netpoll, 850 #endif 851 }; 852 853 static void virtnet_update_status(struct virtnet_info *vi) 854 { 855 u16 v; 856 857 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) 858 return; 859 860 vi->vdev->config->get(vi->vdev, 861 offsetof(struct virtio_net_config, status), 862 &v, sizeof(v)); 863 864 /* Ignore unknown (future) status bits */ 865 v &= VIRTIO_NET_S_LINK_UP; 866 867 if (vi->status == v) 868 return; 869 870 vi->status = v; 871 872 if (vi->status & VIRTIO_NET_S_LINK_UP) { 873 netif_carrier_on(vi->dev); 874 netif_wake_queue(vi->dev); 875 } else { 876 netif_carrier_off(vi->dev); 877 netif_stop_queue(vi->dev); 878 } 879 } 880 881 static void virtnet_config_changed(struct virtio_device *vdev) 882 { 883 struct virtnet_info *vi = vdev->priv; 884 885 virtnet_update_status(vi); 886 } 887 888 static int virtnet_probe(struct virtio_device *vdev) 889 { 890 int err; 891 struct net_device *dev; 892 struct virtnet_info *vi; 893 struct virtqueue *vqs[3]; 894 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 895 const char *names[] = { "input", "output", "control" }; 896 int nvqs; 897 898 /* Allocate ourselves a network device with room for our info */ 899 dev = alloc_etherdev(sizeof(struct virtnet_info)); 900 if (!dev) 901 return -ENOMEM; 902 903 /* Set up network device as normal. */ 904 dev->netdev_ops = &virtnet_netdev; 905 dev->features = NETIF_F_HIGHDMA; 906 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 907 SET_NETDEV_DEV(dev, &vdev->dev); 908 909 /* Do we support "hardware" checksums? */ 910 if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 911 /* This opens up the world of extra features. */ 912 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 913 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 914 dev->features |= NETIF_F_TSO | NETIF_F_UFO 915 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 916 } 917 /* Individual feature bits: what can host handle? */ 918 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 919 dev->features |= NETIF_F_TSO; 920 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 921 dev->features |= NETIF_F_TSO6; 922 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 923 dev->features |= NETIF_F_TSO_ECN; 924 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 925 dev->features |= NETIF_F_UFO; 926 } 927 928 /* Configuration may specify what MAC to use. Otherwise random. */ 929 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 930 vdev->config->get(vdev, 931 offsetof(struct virtio_net_config, mac), 932 dev->dev_addr, dev->addr_len); 933 } else 934 random_ether_addr(dev->dev_addr); 935 936 /* Set up our device-specific information */ 937 vi = netdev_priv(dev); 938 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 939 vi->dev = dev; 940 vi->vdev = vdev; 941 vdev->priv = vi; 942 vi->pages = NULL; 943 INIT_DELAYED_WORK(&vi->refill, refill_work); 944 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); 945 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); 946 947 /* If we can receive ANY GSO packets, we must allocate large ones. */ 948 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 949 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 950 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 951 vi->big_packets = true; 952 953 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 954 vi->mergeable_rx_bufs = true; 955 956 /* We expect two virtqueues, receive then send, 957 * and optionally control. */ 958 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 959 960 err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); 961 if (err) 962 goto free; 963 964 vi->rvq = vqs[0]; 965 vi->svq = vqs[1]; 966 967 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 968 vi->cvq = vqs[2]; 969 970 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 971 dev->features |= NETIF_F_HW_VLAN_FILTER; 972 } 973 974 err = register_netdev(dev); 975 if (err) { 976 pr_debug("virtio_net: registering device failed\n"); 977 goto free_vqs; 978 } 979 980 /* Last of all, set up some receive buffers. */ 981 try_fill_recv(vi, GFP_KERNEL); 982 983 /* If we didn't even get one input buffer, we're useless. */ 984 if (vi->num == 0) { 985 err = -ENOMEM; 986 goto unregister; 987 } 988 989 vi->status = VIRTIO_NET_S_LINK_UP; 990 virtnet_update_status(vi); 991 netif_carrier_on(dev); 992 993 pr_debug("virtnet: registered device %s\n", dev->name); 994 return 0; 995 996 unregister: 997 unregister_netdev(dev); 998 cancel_delayed_work_sync(&vi->refill); 999 free_vqs: 1000 vdev->config->del_vqs(vdev); 1001 free: 1002 free_netdev(dev); 1003 return err; 1004 } 1005 1006 static void free_unused_bufs(struct virtnet_info *vi) 1007 { 1008 void *buf; 1009 while (1) { 1010 buf = virtqueue_detach_unused_buf(vi->svq); 1011 if (!buf) 1012 break; 1013 dev_kfree_skb(buf); 1014 } 1015 while (1) { 1016 buf = virtqueue_detach_unused_buf(vi->rvq); 1017 if (!buf) 1018 break; 1019 if (vi->mergeable_rx_bufs || vi->big_packets) 1020 give_pages(vi, buf); 1021 else 1022 dev_kfree_skb(buf); 1023 --vi->num; 1024 } 1025 BUG_ON(vi->num != 0); 1026 } 1027 1028 static void __devexit virtnet_remove(struct virtio_device *vdev) 1029 { 1030 struct virtnet_info *vi = vdev->priv; 1031 1032 /* Stop all the virtqueues. */ 1033 vdev->config->reset(vdev); 1034 1035 1036 unregister_netdev(vi->dev); 1037 cancel_delayed_work_sync(&vi->refill); 1038 1039 /* Free unused buffers in both send and recv, if any. */ 1040 free_unused_bufs(vi); 1041 1042 vdev->config->del_vqs(vi->vdev); 1043 1044 while (vi->pages) 1045 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1046 1047 free_netdev(vi->dev); 1048 } 1049 1050 static struct virtio_device_id id_table[] = { 1051 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1052 { 0 }, 1053 }; 1054 1055 static unsigned int features[] = { 1056 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1057 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1058 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1059 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1060 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1061 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1062 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1063 }; 1064 1065 static struct virtio_driver virtio_net_driver = { 1066 .feature_table = features, 1067 .feature_table_size = ARRAY_SIZE(features), 1068 .driver.name = KBUILD_MODNAME, 1069 .driver.owner = THIS_MODULE, 1070 .id_table = id_table, 1071 .probe = virtnet_probe, 1072 .remove = __devexit_p(virtnet_remove), 1073 .config_changed = virtnet_config_changed, 1074 }; 1075 1076 static int __init init(void) 1077 { 1078 return register_virtio_driver(&virtio_net_driver); 1079 } 1080 1081 static void __exit fini(void) 1082 { 1083 unregister_virtio_driver(&virtio_net_driver); 1084 } 1085 module_init(init); 1086 module_exit(fini); 1087 1088 MODULE_DEVICE_TABLE(virtio, id_table); 1089 MODULE_DESCRIPTION("Virtio network driver"); 1090 MODULE_LICENSE("GPL"); 1091