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 30static int napi_weight = 128; 31module_param(napi_weight, int, 0444); 32 33static bool csum = true, gso = true; 34module_param(csum, bool, 0444); 35module_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#define VIRTNET_DRIVER_VERSION "1.0.0" 43 44struct virtnet_stats { 45 struct u64_stats_sync syncp; 46 u64 tx_bytes; 47 u64 tx_packets; 48 49 u64 rx_bytes; 50 u64 rx_packets; 51}; 52 53struct virtnet_info { 54 struct virtio_device *vdev; 55 struct virtqueue *rvq, *svq, *cvq; 56 struct net_device *dev; 57 struct napi_struct napi; 58 unsigned int status; 59 60 /* Number of input buffers, and max we've ever had. */ 61 unsigned int num, max; 62 63 /* I like... big packets and I cannot lie! */ 64 bool big_packets; 65 66 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 67 bool mergeable_rx_bufs; 68 69 /* Active statistics */ 70 struct virtnet_stats __percpu *stats; 71 72 /* Work struct for refilling if we run low on memory. */ 73 struct delayed_work refill; 74 75 /* Chain pages by the private ptr. */ 76 struct page *pages; 77 78 /* fragments + linear part + virtio header */ 79 struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; 80 struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; 81}; 82 83struct skb_vnet_hdr { 84 union { 85 struct virtio_net_hdr hdr; 86 struct virtio_net_hdr_mrg_rxbuf mhdr; 87 }; 88 unsigned int num_sg; 89}; 90 91struct padded_vnet_hdr { 92 struct virtio_net_hdr hdr; 93 /* 94 * virtio_net_hdr should be in a separated sg buffer because of a 95 * QEMU bug, and data sg buffer shares same page with this header sg. 96 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 97 */ 98 char padding[6]; 99}; 100 101static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 102{ 103 return (struct skb_vnet_hdr *)skb->cb; 104} 105 106/* 107 * private is used to chain pages for big packets, put the whole 108 * most recent used list in the beginning for reuse 109 */ 110static void give_pages(struct virtnet_info *vi, struct page *page) 111{ 112 struct page *end; 113 114 /* Find end of list, sew whole thing into vi->pages. */ 115 for (end = page; end->private; end = (struct page *)end->private); 116 end->private = (unsigned long)vi->pages; 117 vi->pages = page; 118} 119 120static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) 121{ 122 struct page *p = vi->pages; 123 124 if (p) { 125 vi->pages = (struct page *)p->private; 126 /* clear private here, it is used to chain pages */ 127 p->private = 0; 128 } else 129 p = alloc_page(gfp_mask); 130 return p; 131} 132 133static void skb_xmit_done(struct virtqueue *svq) 134{ 135 struct virtnet_info *vi = svq->vdev->priv; 136 137 /* Suppress further interrupts. */ 138 virtqueue_disable_cb(svq); 139 140 /* We were probably waiting for more output buffers. */ 141 netif_wake_queue(vi->dev); 142} 143 144static void set_skb_frag(struct sk_buff *skb, struct page *page, 145 unsigned int offset, unsigned int *len) 146{ 147 int size = min((unsigned)PAGE_SIZE - offset, *len); 148 int i = skb_shinfo(skb)->nr_frags; 149 150 __skb_fill_page_desc(skb, i, page, offset, size); 151 152 skb->data_len += size; 153 skb->len += size; 154 skb->truesize += PAGE_SIZE; 155 skb_shinfo(skb)->nr_frags++; 156 *len -= size; 157} 158 159/* Called from bottom half context */ 160static struct sk_buff *page_to_skb(struct virtnet_info *vi, 161 struct page *page, unsigned int len) 162{ 163 struct sk_buff *skb; 164 struct skb_vnet_hdr *hdr; 165 unsigned int copy, hdr_len, offset; 166 char *p; 167 168 p = page_address(page); 169 170 /* copy small packet so we can reuse these pages for small data */ 171 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 172 if (unlikely(!skb)) 173 return NULL; 174 175 hdr = skb_vnet_hdr(skb); 176 177 if (vi->mergeable_rx_bufs) { 178 hdr_len = sizeof hdr->mhdr; 179 offset = hdr_len; 180 } else { 181 hdr_len = sizeof hdr->hdr; 182 offset = sizeof(struct padded_vnet_hdr); 183 } 184 185 memcpy(hdr, p, hdr_len); 186 187 len -= hdr_len; 188 p += offset; 189 190 copy = len; 191 if (copy > skb_tailroom(skb)) 192 copy = skb_tailroom(skb); 193 memcpy(skb_put(skb, copy), p, copy); 194 195 len -= copy; 196 offset += copy; 197 198 /* 199 * Verify that we can indeed put this data into a skb. 200 * This is here to handle cases when the device erroneously 201 * tries to receive more than is possible. This is usually 202 * the case of a broken device. 203 */ 204 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 205 if (net_ratelimit()) 206 pr_debug("%s: too much data\n", skb->dev->name); 207 dev_kfree_skb(skb); 208 return NULL; 209 } 210 211 while (len) { 212 set_skb_frag(skb, page, offset, &len); 213 page = (struct page *)page->private; 214 offset = 0; 215 } 216 217 if (page) 218 give_pages(vi, page); 219 220 return skb; 221} 222 223static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) 224{ 225 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 226 struct page *page; 227 int num_buf, i, len; 228 229 num_buf = hdr->mhdr.num_buffers; 230 while (--num_buf) { 231 i = skb_shinfo(skb)->nr_frags; 232 if (i >= MAX_SKB_FRAGS) { 233 pr_debug("%s: packet too long\n", skb->dev->name); 234 skb->dev->stats.rx_length_errors++; 235 return -EINVAL; 236 } 237 page = virtqueue_get_buf(vi->rvq, &len); 238 if (!page) { 239 pr_debug("%s: rx error: %d buffers missing\n", 240 skb->dev->name, hdr->mhdr.num_buffers); 241 skb->dev->stats.rx_length_errors++; 242 return -EINVAL; 243 } 244 245 if (len > PAGE_SIZE) 246 len = PAGE_SIZE; 247 248 set_skb_frag(skb, page, 0, &len); 249 250 --vi->num; 251 } 252 return 0; 253} 254 255static void receive_buf(struct net_device *dev, void *buf, unsigned int len) 256{ 257 struct virtnet_info *vi = netdev_priv(dev); 258 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 259 struct sk_buff *skb; 260 struct page *page; 261 struct skb_vnet_hdr *hdr; 262 263 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 264 pr_debug("%s: short packet %i\n", dev->name, len); 265 dev->stats.rx_length_errors++; 266 if (vi->mergeable_rx_bufs || vi->big_packets) 267 give_pages(vi, buf); 268 else 269 dev_kfree_skb(buf); 270 return; 271 } 272 273 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 274 skb = buf; 275 len -= sizeof(struct virtio_net_hdr); 276 skb_trim(skb, len); 277 } else { 278 page = buf; 279 skb = page_to_skb(vi, page, len); 280 if (unlikely(!skb)) { 281 dev->stats.rx_dropped++; 282 give_pages(vi, page); 283 return; 284 } 285 if (vi->mergeable_rx_bufs) 286 if (receive_mergeable(vi, skb)) { 287 dev_kfree_skb(skb); 288 return; 289 } 290 } 291 292 hdr = skb_vnet_hdr(skb); 293 294 u64_stats_update_begin(&stats->syncp); 295 stats->rx_bytes += skb->len; 296 stats->rx_packets++; 297 u64_stats_update_end(&stats->syncp); 298 299 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 300 pr_debug("Needs csum!\n"); 301 if (!skb_partial_csum_set(skb, 302 hdr->hdr.csum_start, 303 hdr->hdr.csum_offset)) 304 goto frame_err; 305 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 306 skb->ip_summed = CHECKSUM_UNNECESSARY; 307 } 308 309 skb->protocol = eth_type_trans(skb, dev); 310 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 311 ntohs(skb->protocol), skb->len, skb->pkt_type); 312 313 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 314 pr_debug("GSO!\n"); 315 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 316 case VIRTIO_NET_HDR_GSO_TCPV4: 317 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 318 break; 319 case VIRTIO_NET_HDR_GSO_UDP: 320 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 321 break; 322 case VIRTIO_NET_HDR_GSO_TCPV6: 323 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 324 break; 325 default: 326 if (net_ratelimit()) 327 printk(KERN_WARNING "%s: bad gso type %u.\n", 328 dev->name, hdr->hdr.gso_type); 329 goto frame_err; 330 } 331 332 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 333 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 334 335 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 336 if (skb_shinfo(skb)->gso_size == 0) { 337 if (net_ratelimit()) 338 printk(KERN_WARNING "%s: zero gso size.\n", 339 dev->name); 340 goto frame_err; 341 } 342 343 /* Header must be checked, and gso_segs computed. */ 344 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 345 skb_shinfo(skb)->gso_segs = 0; 346 } 347 348 netif_receive_skb(skb); 349 return; 350 351frame_err: 352 dev->stats.rx_frame_errors++; 353 dev_kfree_skb(skb); 354} 355 356static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) 357{ 358 struct sk_buff *skb; 359 struct skb_vnet_hdr *hdr; 360 int err; 361 362 skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); 363 if (unlikely(!skb)) 364 return -ENOMEM; 365 366 skb_put(skb, MAX_PACKET_LEN); 367 368 hdr = skb_vnet_hdr(skb); 369 sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); 370 371 skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); 372 373 err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); 374 if (err < 0) 375 dev_kfree_skb(skb); 376 377 return err; 378} 379 380static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) 381{ 382 struct page *first, *list = NULL; 383 char *p; 384 int i, err, offset; 385 386 /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ 387 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 388 first = get_a_page(vi, gfp); 389 if (!first) { 390 if (list) 391 give_pages(vi, list); 392 return -ENOMEM; 393 } 394 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); 395 396 /* chain new page in list head to match sg */ 397 first->private = (unsigned long)list; 398 list = first; 399 } 400 401 first = get_a_page(vi, gfp); 402 if (!first) { 403 give_pages(vi, list); 404 return -ENOMEM; 405 } 406 p = page_address(first); 407 408 /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ 409 /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ 410 sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); 411 412 /* vi->rx_sg[1] for data packet, from offset */ 413 offset = sizeof(struct padded_vnet_hdr); 414 sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); 415 416 /* chain first in list head */ 417 first->private = (unsigned long)list; 418 err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, 419 first, gfp); 420 if (err < 0) 421 give_pages(vi, first); 422 423 return err; 424} 425 426static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 427{ 428 struct page *page; 429 int err; 430 431 page = get_a_page(vi, gfp); 432 if (!page) 433 return -ENOMEM; 434 435 sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); 436 437 err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 1, page, gfp); 438 if (err < 0) 439 give_pages(vi, page); 440 441 return err; 442} 443 444/* 445 * Returns false if we couldn't fill entirely (OOM). 446 * 447 * Normally run in the receive path, but can also be run from ndo_open 448 * before we're receiving packets, or from refill_work which is 449 * careful to disable receiving (using napi_disable). 450 */ 451static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) 452{ 453 int err; 454 bool oom; 455 456 do { 457 if (vi->mergeable_rx_bufs) 458 err = add_recvbuf_mergeable(vi, gfp); 459 else if (vi->big_packets) 460 err = add_recvbuf_big(vi, gfp); 461 else 462 err = add_recvbuf_small(vi, gfp); 463 464 oom = err == -ENOMEM; 465 if (err < 0) 466 break; 467 ++vi->num; 468 } while (err > 0); 469 if (unlikely(vi->num > vi->max)) 470 vi->max = vi->num; 471 virtqueue_kick(vi->rvq); 472 return !oom; 473} 474 475static void skb_recv_done(struct virtqueue *rvq) 476{ 477 struct virtnet_info *vi = rvq->vdev->priv; 478 /* Schedule NAPI, Suppress further interrupts if successful. */ 479 if (napi_schedule_prep(&vi->napi)) { 480 virtqueue_disable_cb(rvq); 481 __napi_schedule(&vi->napi); 482 } 483} 484 485static void virtnet_napi_enable(struct virtnet_info *vi) 486{ 487 napi_enable(&vi->napi); 488 489 /* If all buffers were filled by other side before we napi_enabled, we 490 * won't get another interrupt, so process any outstanding packets 491 * now. virtnet_poll wants re-enable the queue, so we disable here. 492 * We synchronize against interrupts via NAPI_STATE_SCHED */ 493 if (napi_schedule_prep(&vi->napi)) { 494 virtqueue_disable_cb(vi->rvq); 495 __napi_schedule(&vi->napi); 496 } 497} 498 499static void refill_work(struct work_struct *work) 500{ 501 struct virtnet_info *vi; 502 bool still_empty; 503 504 vi = container_of(work, struct virtnet_info, refill.work); 505 napi_disable(&vi->napi); 506 still_empty = !try_fill_recv(vi, GFP_KERNEL); 507 virtnet_napi_enable(vi); 508 509 /* In theory, this can happen: if we don't get any buffers in 510 * we will *never* try to fill again. */ 511 if (still_empty) 512 queue_delayed_work(system_nrt_wq, &vi->refill, HZ/2); 513} 514 515static int virtnet_poll(struct napi_struct *napi, int budget) 516{ 517 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); 518 void *buf; 519 unsigned int len, received = 0; 520 521again: 522 while (received < budget && 523 (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) { 524 receive_buf(vi->dev, buf, len); 525 --vi->num; 526 received++; 527 } 528 529 if (vi->num < vi->max / 2) { 530 if (!try_fill_recv(vi, GFP_ATOMIC)) 531 queue_delayed_work(system_nrt_wq, &vi->refill, 0); 532 } 533 534 /* Out of packets? */ 535 if (received < budget) { 536 napi_complete(napi); 537 if (unlikely(!virtqueue_enable_cb(vi->rvq)) && 538 napi_schedule_prep(napi)) { 539 virtqueue_disable_cb(vi->rvq); 540 __napi_schedule(napi); 541 goto again; 542 } 543 } 544 545 return received; 546} 547 548static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) 549{ 550 struct sk_buff *skb; 551 unsigned int len, tot_sgs = 0; 552 struct virtnet_stats __percpu *stats = this_cpu_ptr(vi->stats); 553 554 while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { 555 pr_debug("Sent skb %p\n", skb); 556 557 u64_stats_update_begin(&stats->syncp); 558 stats->tx_bytes += skb->len; 559 stats->tx_packets++; 560 u64_stats_update_end(&stats->syncp); 561 562 tot_sgs += skb_vnet_hdr(skb)->num_sg; 563 dev_kfree_skb_any(skb); 564 } 565 return tot_sgs; 566} 567 568static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) 569{ 570 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 571 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 572 573 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 574 575 if (skb->ip_summed == CHECKSUM_PARTIAL) { 576 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 577 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 578 hdr->hdr.csum_offset = skb->csum_offset; 579 } else { 580 hdr->hdr.flags = 0; 581 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 582 } 583 584 if (skb_is_gso(skb)) { 585 hdr->hdr.hdr_len = skb_headlen(skb); 586 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 587 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 588 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 589 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 590 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 591 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 592 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 593 else 594 BUG(); 595 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 596 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 597 } else { 598 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 599 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 600 } 601 602 hdr->mhdr.num_buffers = 0; 603 604 /* Encode metadata header at front. */ 605 if (vi->mergeable_rx_bufs) 606 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); 607 else 608 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); 609 610 hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; 611 return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, 612 0, skb, GFP_ATOMIC); 613} 614 615static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 616{ 617 struct virtnet_info *vi = netdev_priv(dev); 618 int capacity; 619 620 /* Free up any pending old buffers before queueing new ones. */ 621 free_old_xmit_skbs(vi); 622 623 /* Try to transmit */ 624 capacity = xmit_skb(vi, skb); 625 626 /* This can happen with OOM and indirect buffers. */ 627 if (unlikely(capacity < 0)) { 628 if (net_ratelimit()) { 629 if (likely(capacity == -ENOMEM)) { 630 dev_warn(&dev->dev, 631 "TX queue failure: out of memory\n"); 632 } else { 633 dev->stats.tx_fifo_errors++; 634 dev_warn(&dev->dev, 635 "Unexpected TX queue failure: %d\n", 636 capacity); 637 } 638 } 639 dev->stats.tx_dropped++; 640 kfree_skb(skb); 641 return NETDEV_TX_OK; 642 } 643 virtqueue_kick(vi->svq); 644 645 /* Don't wait up for transmitted skbs to be freed. */ 646 skb_orphan(skb); 647 nf_reset(skb); 648 649 /* Apparently nice girls don't return TX_BUSY; stop the queue 650 * before it gets out of hand. Naturally, this wastes entries. */ 651 if (capacity < 2+MAX_SKB_FRAGS) { 652 netif_stop_queue(dev); 653 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { 654 /* More just got used, free them then recheck. */ 655 capacity += free_old_xmit_skbs(vi); 656 if (capacity >= 2+MAX_SKB_FRAGS) { 657 netif_start_queue(dev); 658 virtqueue_disable_cb(vi->svq); 659 } 660 } 661 } 662 663 return NETDEV_TX_OK; 664} 665 666static int virtnet_set_mac_address(struct net_device *dev, void *p) 667{ 668 struct virtnet_info *vi = netdev_priv(dev); 669 struct virtio_device *vdev = vi->vdev; 670 int ret; 671 672 ret = eth_mac_addr(dev, p); 673 if (ret) 674 return ret; 675 676 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 677 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 678 dev->dev_addr, dev->addr_len); 679 680 return 0; 681} 682 683static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 684 struct rtnl_link_stats64 *tot) 685{ 686 struct virtnet_info *vi = netdev_priv(dev); 687 int cpu; 688 unsigned int start; 689 690 for_each_possible_cpu(cpu) { 691 struct virtnet_stats __percpu *stats 692 = per_cpu_ptr(vi->stats, cpu); 693 u64 tpackets, tbytes, rpackets, rbytes; 694 695 do { 696 start = u64_stats_fetch_begin(&stats->syncp); 697 tpackets = stats->tx_packets; 698 tbytes = stats->tx_bytes; 699 rpackets = stats->rx_packets; 700 rbytes = stats->rx_bytes; 701 } while (u64_stats_fetch_retry(&stats->syncp, start)); 702 703 tot->rx_packets += rpackets; 704 tot->tx_packets += tpackets; 705 tot->rx_bytes += rbytes; 706 tot->tx_bytes += tbytes; 707 } 708 709 tot->tx_dropped = dev->stats.tx_dropped; 710 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 711 tot->rx_dropped = dev->stats.rx_dropped; 712 tot->rx_length_errors = dev->stats.rx_length_errors; 713 tot->rx_frame_errors = dev->stats.rx_frame_errors; 714 715 return tot; 716} 717 718#ifdef CONFIG_NET_POLL_CONTROLLER 719static void virtnet_netpoll(struct net_device *dev) 720{ 721 struct virtnet_info *vi = netdev_priv(dev); 722 723 napi_schedule(&vi->napi); 724} 725#endif 726 727static int virtnet_open(struct net_device *dev) 728{ 729 struct virtnet_info *vi = netdev_priv(dev); 730 731 /* Make sure we have some buffers: if oom use wq. */ 732 if (!try_fill_recv(vi, GFP_KERNEL)) 733 queue_delayed_work(system_nrt_wq, &vi->refill, 0); 734 735 virtnet_napi_enable(vi); 736 return 0; 737} 738 739/* 740 * Send command via the control virtqueue and check status. Commands 741 * supported by the hypervisor, as indicated by feature bits, should 742 * never fail unless improperly formated. 743 */ 744static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 745 struct scatterlist *data, int out, int in) 746{ 747 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 748 struct virtio_net_ctrl_hdr ctrl; 749 virtio_net_ctrl_ack status = ~0; 750 unsigned int tmp; 751 int i; 752 753 /* Caller should know better */ 754 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 755 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 756 757 out++; /* Add header */ 758 in++; /* Add return status */ 759 760 ctrl.class = class; 761 ctrl.cmd = cmd; 762 763 sg_init_table(sg, out + in); 764 765 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 766 for_each_sg(data, s, out + in - 2, i) 767 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 768 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 769 770 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0); 771 772 virtqueue_kick(vi->cvq); 773 774 /* 775 * Spin for a response, the kick causes an ioport write, trapping 776 * into the hypervisor, so the request should be handled immediately. 777 */ 778 while (!virtqueue_get_buf(vi->cvq, &tmp)) 779 cpu_relax(); 780 781 return status == VIRTIO_NET_OK; 782} 783 784static int virtnet_close(struct net_device *dev) 785{ 786 struct virtnet_info *vi = netdev_priv(dev); 787 788 /* Make sure refill_work doesn't re-enable napi! */ 789 cancel_delayed_work_sync(&vi->refill); 790 napi_disable(&vi->napi); 791 792 return 0; 793} 794 795static void virtnet_set_rx_mode(struct net_device *dev) 796{ 797 struct virtnet_info *vi = netdev_priv(dev); 798 struct scatterlist sg[2]; 799 u8 promisc, allmulti; 800 struct virtio_net_ctrl_mac *mac_data; 801 struct netdev_hw_addr *ha; 802 int uc_count; 803 int mc_count; 804 void *buf; 805 int i; 806 807 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 808 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 809 return; 810 811 promisc = ((dev->flags & IFF_PROMISC) != 0); 812 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 813 814 sg_init_one(sg, &promisc, sizeof(promisc)); 815 816 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 817 VIRTIO_NET_CTRL_RX_PROMISC, 818 sg, 1, 0)) 819 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 820 promisc ? "en" : "dis"); 821 822 sg_init_one(sg, &allmulti, sizeof(allmulti)); 823 824 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 825 VIRTIO_NET_CTRL_RX_ALLMULTI, 826 sg, 1, 0)) 827 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 828 allmulti ? "en" : "dis"); 829 830 uc_count = netdev_uc_count(dev); 831 mc_count = netdev_mc_count(dev); 832 /* MAC filter - use one buffer for both lists */ 833 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 834 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 835 mac_data = buf; 836 if (!buf) { 837 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 838 return; 839 } 840 841 sg_init_table(sg, 2); 842 843 /* Store the unicast list and count in the front of the buffer */ 844 mac_data->entries = uc_count; 845 i = 0; 846 netdev_for_each_uc_addr(ha, dev) 847 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 848 849 sg_set_buf(&sg[0], mac_data, 850 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 851 852 /* multicast list and count fill the end */ 853 mac_data = (void *)&mac_data->macs[uc_count][0]; 854 855 mac_data->entries = mc_count; 856 i = 0; 857 netdev_for_each_mc_addr(ha, dev) 858 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 859 860 sg_set_buf(&sg[1], mac_data, 861 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 862 863 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 864 VIRTIO_NET_CTRL_MAC_TABLE_SET, 865 sg, 2, 0)) 866 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 867 868 kfree(buf); 869} 870 871static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 872{ 873 struct virtnet_info *vi = netdev_priv(dev); 874 struct scatterlist sg; 875 876 sg_init_one(&sg, &vid, sizeof(vid)); 877 878 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 879 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 880 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 881 return 0; 882} 883 884static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 885{ 886 struct virtnet_info *vi = netdev_priv(dev); 887 struct scatterlist sg; 888 889 sg_init_one(&sg, &vid, sizeof(vid)); 890 891 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 892 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 893 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 894 return 0; 895} 896 897static void virtnet_get_ringparam(struct net_device *dev, 898 struct ethtool_ringparam *ring) 899{ 900 struct virtnet_info *vi = netdev_priv(dev); 901 902 ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq); 903 ring->tx_max_pending = virtqueue_get_vring_size(vi->svq); 904 ring->rx_pending = ring->rx_max_pending; 905 ring->tx_pending = ring->tx_max_pending; 906 907} 908 909 910static void virtnet_get_drvinfo(struct net_device *dev, 911 struct ethtool_drvinfo *info) 912{ 913 struct virtnet_info *vi = netdev_priv(dev); 914 struct virtio_device *vdev = vi->vdev; 915 916 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 917 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 918 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 919 920} 921 922static const struct ethtool_ops virtnet_ethtool_ops = { 923 .get_drvinfo = virtnet_get_drvinfo, 924 .get_link = ethtool_op_get_link, 925 .get_ringparam = virtnet_get_ringparam, 926}; 927 928#define MIN_MTU 68 929#define MAX_MTU 65535 930 931static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 932{ 933 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 934 return -EINVAL; 935 dev->mtu = new_mtu; 936 return 0; 937} 938 939static const struct net_device_ops virtnet_netdev = { 940 .ndo_open = virtnet_open, 941 .ndo_stop = virtnet_close, 942 .ndo_start_xmit = start_xmit, 943 .ndo_validate_addr = eth_validate_addr, 944 .ndo_set_mac_address = virtnet_set_mac_address, 945 .ndo_set_rx_mode = virtnet_set_rx_mode, 946 .ndo_change_mtu = virtnet_change_mtu, 947 .ndo_get_stats64 = virtnet_stats, 948 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 949 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 950#ifdef CONFIG_NET_POLL_CONTROLLER 951 .ndo_poll_controller = virtnet_netpoll, 952#endif 953}; 954 955static void virtnet_update_status(struct virtnet_info *vi) 956{ 957 u16 v; 958 959 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS, 960 offsetof(struct virtio_net_config, status), 961 &v) < 0) 962 return; 963 964 /* Ignore unknown (future) status bits */ 965 v &= VIRTIO_NET_S_LINK_UP; 966 967 if (vi->status == v) 968 return; 969 970 vi->status = v; 971 972 if (vi->status & VIRTIO_NET_S_LINK_UP) { 973 netif_carrier_on(vi->dev); 974 netif_wake_queue(vi->dev); 975 } else { 976 netif_carrier_off(vi->dev); 977 netif_stop_queue(vi->dev); 978 } 979} 980 981static void virtnet_config_changed(struct virtio_device *vdev) 982{ 983 struct virtnet_info *vi = vdev->priv; 984 985 virtnet_update_status(vi); 986} 987 988static int init_vqs(struct virtnet_info *vi) 989{ 990 struct virtqueue *vqs[3]; 991 vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; 992 const char *names[] = { "input", "output", "control" }; 993 int nvqs, err; 994 995 /* We expect two virtqueues, receive then send, 996 * and optionally control. */ 997 nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; 998 999 err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names); 1000 if (err) 1001 return err; 1002 1003 vi->rvq = vqs[0]; 1004 vi->svq = vqs[1]; 1005 1006 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { 1007 vi->cvq = vqs[2]; 1008 1009 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1010 vi->dev->features |= NETIF_F_HW_VLAN_FILTER; 1011 } 1012 return 0; 1013} 1014 1015static int virtnet_probe(struct virtio_device *vdev) 1016{ 1017 int err; 1018 struct net_device *dev; 1019 struct virtnet_info *vi; 1020 1021 /* Allocate ourselves a network device with room for our info */ 1022 dev = alloc_etherdev(sizeof(struct virtnet_info)); 1023 if (!dev) 1024 return -ENOMEM; 1025 1026 /* Set up network device as normal. */ 1027 dev->priv_flags |= IFF_UNICAST_FLT; 1028 dev->netdev_ops = &virtnet_netdev; 1029 dev->features = NETIF_F_HIGHDMA; 1030 1031 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 1032 SET_NETDEV_DEV(dev, &vdev->dev); 1033 1034 /* Do we support "hardware" checksums? */ 1035 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 1036 /* This opens up the world of extra features. */ 1037 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1038 if (csum) 1039 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1040 1041 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 1042 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 1043 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 1044 } 1045 /* Individual feature bits: what can host handle? */ 1046 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 1047 dev->hw_features |= NETIF_F_TSO; 1048 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 1049 dev->hw_features |= NETIF_F_TSO6; 1050 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 1051 dev->hw_features |= NETIF_F_TSO_ECN; 1052 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1053 dev->hw_features |= NETIF_F_UFO; 1054 1055 if (gso) 1056 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1057 /* (!csum && gso) case will be fixed by register_netdev() */ 1058 } 1059 1060 /* Configuration may specify what MAC to use. Otherwise random. */ 1061 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC, 1062 offsetof(struct virtio_net_config, mac), 1063 dev->dev_addr, dev->addr_len) < 0) 1064 random_ether_addr(dev->dev_addr); 1065 1066 /* Set up our device-specific information */ 1067 vi = netdev_priv(dev); 1068 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); 1069 vi->dev = dev; 1070 vi->vdev = vdev; 1071 vdev->priv = vi; 1072 vi->pages = NULL; 1073 vi->stats = alloc_percpu(struct virtnet_stats); 1074 err = -ENOMEM; 1075 if (vi->stats == NULL) 1076 goto free; 1077 1078 INIT_DELAYED_WORK(&vi->refill, refill_work); 1079 sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); 1080 sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); 1081 1082 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1083 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1084 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1085 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1086 vi->big_packets = true; 1087 1088 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1089 vi->mergeable_rx_bufs = true; 1090 1091 err = init_vqs(vi); 1092 if (err) 1093 goto free_stats; 1094 1095 err = register_netdev(dev); 1096 if (err) { 1097 pr_debug("virtio_net: registering device failed\n"); 1098 goto free_vqs; 1099 } 1100 1101 /* Last of all, set up some receive buffers. */ 1102 try_fill_recv(vi, GFP_KERNEL); 1103 1104 /* If we didn't even get one input buffer, we're useless. */ 1105 if (vi->num == 0) { 1106 err = -ENOMEM; 1107 goto unregister; 1108 } 1109 1110 /* Assume link up if device can't report link status, 1111 otherwise get link status from config. */ 1112 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1113 netif_carrier_off(dev); 1114 virtnet_update_status(vi); 1115 } else { 1116 vi->status = VIRTIO_NET_S_LINK_UP; 1117 netif_carrier_on(dev); 1118 } 1119 1120 pr_debug("virtnet: registered device %s\n", dev->name); 1121 return 0; 1122 1123unregister: 1124 unregister_netdev(dev); 1125free_vqs: 1126 vdev->config->del_vqs(vdev); 1127free_stats: 1128 free_percpu(vi->stats); 1129free: 1130 free_netdev(dev); 1131 return err; 1132} 1133 1134static void free_unused_bufs(struct virtnet_info *vi) 1135{ 1136 void *buf; 1137 while (1) { 1138 buf = virtqueue_detach_unused_buf(vi->svq); 1139 if (!buf) 1140 break; 1141 dev_kfree_skb(buf); 1142 } 1143 while (1) { 1144 buf = virtqueue_detach_unused_buf(vi->rvq); 1145 if (!buf) 1146 break; 1147 if (vi->mergeable_rx_bufs || vi->big_packets) 1148 give_pages(vi, buf); 1149 else 1150 dev_kfree_skb(buf); 1151 --vi->num; 1152 } 1153 BUG_ON(vi->num != 0); 1154} 1155 1156static void remove_vq_common(struct virtnet_info *vi) 1157{ 1158 vi->vdev->config->reset(vi->vdev); 1159 1160 /* Free unused buffers in both send and recv, if any. */ 1161 free_unused_bufs(vi); 1162 1163 vi->vdev->config->del_vqs(vi->vdev); 1164 1165 while (vi->pages) 1166 __free_pages(get_a_page(vi, GFP_KERNEL), 0); 1167} 1168 1169static void __devexit virtnet_remove(struct virtio_device *vdev) 1170{ 1171 struct virtnet_info *vi = vdev->priv; 1172 1173 unregister_netdev(vi->dev); 1174 1175 remove_vq_common(vi); 1176 1177 free_percpu(vi->stats); 1178 free_netdev(vi->dev); 1179} 1180 1181#ifdef CONFIG_PM 1182static int virtnet_freeze(struct virtio_device *vdev) 1183{ 1184 struct virtnet_info *vi = vdev->priv; 1185 1186 virtqueue_disable_cb(vi->rvq); 1187 virtqueue_disable_cb(vi->svq); 1188 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) 1189 virtqueue_disable_cb(vi->cvq); 1190 1191 netif_device_detach(vi->dev); 1192 cancel_delayed_work_sync(&vi->refill); 1193 1194 if (netif_running(vi->dev)) 1195 napi_disable(&vi->napi); 1196 1197 remove_vq_common(vi); 1198 1199 return 0; 1200} 1201 1202static int virtnet_restore(struct virtio_device *vdev) 1203{ 1204 struct virtnet_info *vi = vdev->priv; 1205 int err; 1206 1207 err = init_vqs(vi); 1208 if (err) 1209 return err; 1210 1211 if (netif_running(vi->dev)) 1212 virtnet_napi_enable(vi); 1213 1214 netif_device_attach(vi->dev); 1215 1216 if (!try_fill_recv(vi, GFP_KERNEL)) 1217 queue_delayed_work(system_nrt_wq, &vi->refill, 0); 1218 1219 return 0; 1220} 1221#endif 1222 1223static struct virtio_device_id id_table[] = { 1224 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1225 { 0 }, 1226}; 1227 1228static unsigned int features[] = { 1229 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1230 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1231 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1232 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1233 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1234 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1235 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1236}; 1237 1238static struct virtio_driver virtio_net_driver = { 1239 .feature_table = features, 1240 .feature_table_size = ARRAY_SIZE(features), 1241 .driver.name = KBUILD_MODNAME, 1242 .driver.owner = THIS_MODULE, 1243 .id_table = id_table, 1244 .probe = virtnet_probe, 1245 .remove = __devexit_p(virtnet_remove), 1246 .config_changed = virtnet_config_changed, 1247#ifdef CONFIG_PM 1248 .freeze = virtnet_freeze, 1249 .restore = virtnet_restore, 1250#endif 1251}; 1252 1253static int __init init(void) 1254{ 1255 return register_virtio_driver(&virtio_net_driver); 1256} 1257 1258static void __exit fini(void) 1259{ 1260 unregister_virtio_driver(&virtio_net_driver); 1261} 1262module_init(init); 1263module_exit(fini); 1264 1265MODULE_DEVICE_TABLE(virtio, id_table); 1266MODULE_DESCRIPTION("Virtio network driver"); 1267MODULE_LICENSE("GPL"); 1268