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 #include <linux/cpu.h> 30 31 static int napi_weight = NAPI_POLL_WEIGHT; 32 module_param(napi_weight, int, 0444); 33 34 static bool csum = true, gso = true; 35 module_param(csum, bool, 0444); 36 module_param(gso, bool, 0444); 37 38 /* FIXME: MTU in config. */ 39 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 40 #define GOOD_COPY_LEN 128 41 42 #define VIRTNET_DRIVER_VERSION "1.0.0" 43 44 struct virtnet_stats { 45 struct u64_stats_sync tx_syncp; 46 struct u64_stats_sync rx_syncp; 47 u64 tx_bytes; 48 u64 tx_packets; 49 50 u64 rx_bytes; 51 u64 rx_packets; 52 }; 53 54 /* Internal representation of a send virtqueue */ 55 struct send_queue { 56 /* Virtqueue associated with this send _queue */ 57 struct virtqueue *vq; 58 59 /* TX: fragments + linear part + virtio header */ 60 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 61 62 /* Name of the send queue: output.$index */ 63 char name[40]; 64 }; 65 66 /* Internal representation of a receive virtqueue */ 67 struct receive_queue { 68 /* Virtqueue associated with this receive_queue */ 69 struct virtqueue *vq; 70 71 struct napi_struct napi; 72 73 /* Number of input buffers, and max we've ever had. */ 74 unsigned int num, max; 75 76 /* Chain pages by the private ptr. */ 77 struct page *pages; 78 79 /* RX: fragments + linear part + virtio header */ 80 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 81 82 /* Name of this receive queue: input.$index */ 83 char name[40]; 84 }; 85 86 struct virtnet_info { 87 struct virtio_device *vdev; 88 struct virtqueue *cvq; 89 struct net_device *dev; 90 struct send_queue *sq; 91 struct receive_queue *rq; 92 unsigned int status; 93 94 /* Max # of queue pairs supported by the device */ 95 u16 max_queue_pairs; 96 97 /* # of queue pairs currently used by the driver */ 98 u16 curr_queue_pairs; 99 100 /* I like... big packets and I cannot lie! */ 101 bool big_packets; 102 103 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 104 bool mergeable_rx_bufs; 105 106 /* Has control virtqueue */ 107 bool has_cvq; 108 109 /* Host can handle any s/g split between our header and packet data */ 110 bool any_header_sg; 111 112 /* enable config space updates */ 113 bool config_enable; 114 115 /* Active statistics */ 116 struct virtnet_stats __percpu *stats; 117 118 /* Work struct for refilling if we run low on memory. */ 119 struct delayed_work refill; 120 121 /* Work struct for config space updates */ 122 struct work_struct config_work; 123 124 /* Lock for config space updates */ 125 struct mutex config_lock; 126 127 /* Does the affinity hint is set for virtqueues? */ 128 bool affinity_hint_set; 129 130 /* Per-cpu variable to show the mapping from CPU to virtqueue */ 131 int __percpu *vq_index; 132 133 /* CPU hot plug notifier */ 134 struct notifier_block nb; 135 }; 136 137 struct skb_vnet_hdr { 138 union { 139 struct virtio_net_hdr hdr; 140 struct virtio_net_hdr_mrg_rxbuf mhdr; 141 }; 142 }; 143 144 struct padded_vnet_hdr { 145 struct virtio_net_hdr hdr; 146 /* 147 * virtio_net_hdr should be in a separated sg buffer because of a 148 * QEMU bug, and data sg buffer shares same page with this header sg. 149 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 150 */ 151 char padding[6]; 152 }; 153 154 /* Converting between virtqueue no. and kernel tx/rx queue no. 155 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq 156 */ 157 static int vq2txq(struct virtqueue *vq) 158 { 159 return (vq->index - 1) / 2; 160 } 161 162 static int txq2vq(int txq) 163 { 164 return txq * 2 + 1; 165 } 166 167 static int vq2rxq(struct virtqueue *vq) 168 { 169 return vq->index / 2; 170 } 171 172 static int rxq2vq(int rxq) 173 { 174 return rxq * 2; 175 } 176 177 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 178 { 179 return (struct skb_vnet_hdr *)skb->cb; 180 } 181 182 /* 183 * private is used to chain pages for big packets, put the whole 184 * most recent used list in the beginning for reuse 185 */ 186 static void give_pages(struct receive_queue *rq, struct page *page) 187 { 188 struct page *end; 189 190 /* Find end of list, sew whole thing into vi->rq.pages. */ 191 for (end = page; end->private; end = (struct page *)end->private); 192 end->private = (unsigned long)rq->pages; 193 rq->pages = page; 194 } 195 196 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) 197 { 198 struct page *p = rq->pages; 199 200 if (p) { 201 rq->pages = (struct page *)p->private; 202 /* clear private here, it is used to chain pages */ 203 p->private = 0; 204 } else 205 p = alloc_page(gfp_mask); 206 return p; 207 } 208 209 static void skb_xmit_done(struct virtqueue *vq) 210 { 211 struct virtnet_info *vi = vq->vdev->priv; 212 213 /* Suppress further interrupts. */ 214 virtqueue_disable_cb(vq); 215 216 /* We were probably waiting for more output buffers. */ 217 netif_wake_subqueue(vi->dev, vq2txq(vq)); 218 } 219 220 static void set_skb_frag(struct sk_buff *skb, struct page *page, 221 unsigned int offset, unsigned int *len) 222 { 223 int size = min((unsigned)PAGE_SIZE - offset, *len); 224 int i = skb_shinfo(skb)->nr_frags; 225 226 __skb_fill_page_desc(skb, i, page, offset, size); 227 228 skb->data_len += size; 229 skb->len += size; 230 skb->truesize += PAGE_SIZE; 231 skb_shinfo(skb)->nr_frags++; 232 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 233 *len -= size; 234 } 235 236 /* Called from bottom half context */ 237 static struct sk_buff *page_to_skb(struct receive_queue *rq, 238 struct page *page, unsigned int len) 239 { 240 struct virtnet_info *vi = rq->vq->vdev->priv; 241 struct sk_buff *skb; 242 struct skb_vnet_hdr *hdr; 243 unsigned int copy, hdr_len, offset; 244 char *p; 245 246 p = page_address(page); 247 248 /* copy small packet so we can reuse these pages for small data */ 249 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 250 if (unlikely(!skb)) 251 return NULL; 252 253 hdr = skb_vnet_hdr(skb); 254 255 if (vi->mergeable_rx_bufs) { 256 hdr_len = sizeof hdr->mhdr; 257 offset = hdr_len; 258 } else { 259 hdr_len = sizeof hdr->hdr; 260 offset = sizeof(struct padded_vnet_hdr); 261 } 262 263 memcpy(hdr, p, hdr_len); 264 265 len -= hdr_len; 266 p += offset; 267 268 copy = len; 269 if (copy > skb_tailroom(skb)) 270 copy = skb_tailroom(skb); 271 memcpy(skb_put(skb, copy), p, copy); 272 273 len -= copy; 274 offset += copy; 275 276 /* 277 * Verify that we can indeed put this data into a skb. 278 * This is here to handle cases when the device erroneously 279 * tries to receive more than is possible. This is usually 280 * the case of a broken device. 281 */ 282 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 283 net_dbg_ratelimited("%s: too much data\n", skb->dev->name); 284 dev_kfree_skb(skb); 285 return NULL; 286 } 287 288 while (len) { 289 set_skb_frag(skb, page, offset, &len); 290 page = (struct page *)page->private; 291 offset = 0; 292 } 293 294 if (page) 295 give_pages(rq, page); 296 297 return skb; 298 } 299 300 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb) 301 { 302 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 303 struct page *page; 304 int num_buf, i, len; 305 306 num_buf = hdr->mhdr.num_buffers; 307 while (--num_buf) { 308 i = skb_shinfo(skb)->nr_frags; 309 if (i >= MAX_SKB_FRAGS) { 310 pr_debug("%s: packet too long\n", skb->dev->name); 311 skb->dev->stats.rx_length_errors++; 312 return -EINVAL; 313 } 314 page = virtqueue_get_buf(rq->vq, &len); 315 if (!page) { 316 pr_debug("%s: rx error: %d buffers missing\n", 317 skb->dev->name, hdr->mhdr.num_buffers); 318 skb->dev->stats.rx_length_errors++; 319 return -EINVAL; 320 } 321 322 if (len > PAGE_SIZE) 323 len = PAGE_SIZE; 324 325 set_skb_frag(skb, page, 0, &len); 326 327 --rq->num; 328 } 329 return 0; 330 } 331 332 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) 333 { 334 struct virtnet_info *vi = rq->vq->vdev->priv; 335 struct net_device *dev = vi->dev; 336 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 337 struct sk_buff *skb; 338 struct page *page; 339 struct skb_vnet_hdr *hdr; 340 341 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 342 pr_debug("%s: short packet %i\n", dev->name, len); 343 dev->stats.rx_length_errors++; 344 if (vi->mergeable_rx_bufs || vi->big_packets) 345 give_pages(rq, buf); 346 else 347 dev_kfree_skb(buf); 348 return; 349 } 350 351 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 352 skb = buf; 353 len -= sizeof(struct virtio_net_hdr); 354 skb_trim(skb, len); 355 } else { 356 page = buf; 357 skb = page_to_skb(rq, page, len); 358 if (unlikely(!skb)) { 359 dev->stats.rx_dropped++; 360 give_pages(rq, page); 361 return; 362 } 363 if (vi->mergeable_rx_bufs) 364 if (receive_mergeable(rq, skb)) { 365 dev_kfree_skb(skb); 366 return; 367 } 368 } 369 370 hdr = skb_vnet_hdr(skb); 371 372 u64_stats_update_begin(&stats->rx_syncp); 373 stats->rx_bytes += skb->len; 374 stats->rx_packets++; 375 u64_stats_update_end(&stats->rx_syncp); 376 377 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 378 pr_debug("Needs csum!\n"); 379 if (!skb_partial_csum_set(skb, 380 hdr->hdr.csum_start, 381 hdr->hdr.csum_offset)) 382 goto frame_err; 383 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 384 skb->ip_summed = CHECKSUM_UNNECESSARY; 385 } 386 387 skb->protocol = eth_type_trans(skb, dev); 388 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 389 ntohs(skb->protocol), skb->len, skb->pkt_type); 390 391 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 392 pr_debug("GSO!\n"); 393 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 394 case VIRTIO_NET_HDR_GSO_TCPV4: 395 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 396 break; 397 case VIRTIO_NET_HDR_GSO_UDP: 398 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 399 break; 400 case VIRTIO_NET_HDR_GSO_TCPV6: 401 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 402 break; 403 default: 404 net_warn_ratelimited("%s: bad gso type %u.\n", 405 dev->name, hdr->hdr.gso_type); 406 goto frame_err; 407 } 408 409 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 410 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 411 412 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 413 if (skb_shinfo(skb)->gso_size == 0) { 414 net_warn_ratelimited("%s: zero gso size.\n", dev->name); 415 goto frame_err; 416 } 417 418 /* Header must be checked, and gso_segs computed. */ 419 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 420 skb_shinfo(skb)->gso_segs = 0; 421 } 422 423 netif_receive_skb(skb); 424 return; 425 426 frame_err: 427 dev->stats.rx_frame_errors++; 428 dev_kfree_skb(skb); 429 } 430 431 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) 432 { 433 struct virtnet_info *vi = rq->vq->vdev->priv; 434 struct sk_buff *skb; 435 struct skb_vnet_hdr *hdr; 436 int err; 437 438 skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); 439 if (unlikely(!skb)) 440 return -ENOMEM; 441 442 skb_put(skb, MAX_PACKET_LEN); 443 444 hdr = skb_vnet_hdr(skb); 445 sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); 446 447 skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); 448 449 err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp); 450 if (err < 0) 451 dev_kfree_skb(skb); 452 453 return err; 454 } 455 456 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp) 457 { 458 struct page *first, *list = NULL; 459 char *p; 460 int i, err, offset; 461 462 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ 463 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 464 first = get_a_page(rq, gfp); 465 if (!first) { 466 if (list) 467 give_pages(rq, list); 468 return -ENOMEM; 469 } 470 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE); 471 472 /* chain new page in list head to match sg */ 473 first->private = (unsigned long)list; 474 list = first; 475 } 476 477 first = get_a_page(rq, gfp); 478 if (!first) { 479 give_pages(rq, list); 480 return -ENOMEM; 481 } 482 p = page_address(first); 483 484 /* rq->sg[0], rq->sg[1] share the same page */ 485 /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */ 486 sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr)); 487 488 /* rq->sg[1] for data packet, from offset */ 489 offset = sizeof(struct padded_vnet_hdr); 490 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); 491 492 /* chain first in list head */ 493 first->private = (unsigned long)list; 494 err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2, 495 first, gfp); 496 if (err < 0) 497 give_pages(rq, first); 498 499 return err; 500 } 501 502 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) 503 { 504 struct page *page; 505 int err; 506 507 page = get_a_page(rq, gfp); 508 if (!page) 509 return -ENOMEM; 510 511 sg_init_one(rq->sg, page_address(page), PAGE_SIZE); 512 513 err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, page, gfp); 514 if (err < 0) 515 give_pages(rq, page); 516 517 return err; 518 } 519 520 /* 521 * Returns false if we couldn't fill entirely (OOM). 522 * 523 * Normally run in the receive path, but can also be run from ndo_open 524 * before we're receiving packets, or from refill_work which is 525 * careful to disable receiving (using napi_disable). 526 */ 527 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) 528 { 529 struct virtnet_info *vi = rq->vq->vdev->priv; 530 int err; 531 bool oom; 532 533 do { 534 if (vi->mergeable_rx_bufs) 535 err = add_recvbuf_mergeable(rq, gfp); 536 else if (vi->big_packets) 537 err = add_recvbuf_big(rq, gfp); 538 else 539 err = add_recvbuf_small(rq, gfp); 540 541 oom = err == -ENOMEM; 542 if (err) 543 break; 544 ++rq->num; 545 } while (rq->vq->num_free); 546 if (unlikely(rq->num > rq->max)) 547 rq->max = rq->num; 548 virtqueue_kick(rq->vq); 549 return !oom; 550 } 551 552 static void skb_recv_done(struct virtqueue *rvq) 553 { 554 struct virtnet_info *vi = rvq->vdev->priv; 555 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)]; 556 557 /* Schedule NAPI, Suppress further interrupts if successful. */ 558 if (napi_schedule_prep(&rq->napi)) { 559 virtqueue_disable_cb(rvq); 560 __napi_schedule(&rq->napi); 561 } 562 } 563 564 static void virtnet_napi_enable(struct receive_queue *rq) 565 { 566 napi_enable(&rq->napi); 567 568 /* If all buffers were filled by other side before we napi_enabled, we 569 * won't get another interrupt, so process any outstanding packets 570 * now. virtnet_poll wants re-enable the queue, so we disable here. 571 * We synchronize against interrupts via NAPI_STATE_SCHED */ 572 if (napi_schedule_prep(&rq->napi)) { 573 virtqueue_disable_cb(rq->vq); 574 local_bh_disable(); 575 __napi_schedule(&rq->napi); 576 local_bh_enable(); 577 } 578 } 579 580 static void refill_work(struct work_struct *work) 581 { 582 struct virtnet_info *vi = 583 container_of(work, struct virtnet_info, refill.work); 584 bool still_empty; 585 int i; 586 587 for (i = 0; i < vi->curr_queue_pairs; i++) { 588 struct receive_queue *rq = &vi->rq[i]; 589 590 napi_disable(&rq->napi); 591 still_empty = !try_fill_recv(rq, GFP_KERNEL); 592 virtnet_napi_enable(rq); 593 594 /* In theory, this can happen: if we don't get any buffers in 595 * we will *never* try to fill again. 596 */ 597 if (still_empty) 598 schedule_delayed_work(&vi->refill, HZ/2); 599 } 600 } 601 602 static int virtnet_poll(struct napi_struct *napi, int budget) 603 { 604 struct receive_queue *rq = 605 container_of(napi, struct receive_queue, napi); 606 struct virtnet_info *vi = rq->vq->vdev->priv; 607 void *buf; 608 unsigned int r, len, received = 0; 609 610 again: 611 while (received < budget && 612 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { 613 receive_buf(rq, buf, len); 614 --rq->num; 615 received++; 616 } 617 618 if (rq->num < rq->max / 2) { 619 if (!try_fill_recv(rq, GFP_ATOMIC)) 620 schedule_delayed_work(&vi->refill, 0); 621 } 622 623 /* Out of packets? */ 624 if (received < budget) { 625 r = virtqueue_enable_cb_prepare(rq->vq); 626 napi_complete(napi); 627 if (unlikely(virtqueue_poll(rq->vq, r)) && 628 napi_schedule_prep(napi)) { 629 virtqueue_disable_cb(rq->vq); 630 __napi_schedule(napi); 631 goto again; 632 } 633 } 634 635 return received; 636 } 637 638 static int virtnet_open(struct net_device *dev) 639 { 640 struct virtnet_info *vi = netdev_priv(dev); 641 int i; 642 643 for (i = 0; i < vi->max_queue_pairs; i++) { 644 if (i < vi->curr_queue_pairs) 645 /* Make sure we have some buffers: if oom use wq. */ 646 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 647 schedule_delayed_work(&vi->refill, 0); 648 virtnet_napi_enable(&vi->rq[i]); 649 } 650 651 return 0; 652 } 653 654 static void free_old_xmit_skbs(struct send_queue *sq) 655 { 656 struct sk_buff *skb; 657 unsigned int len; 658 struct virtnet_info *vi = sq->vq->vdev->priv; 659 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 660 661 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { 662 pr_debug("Sent skb %p\n", skb); 663 664 u64_stats_update_begin(&stats->tx_syncp); 665 stats->tx_bytes += skb->len; 666 stats->tx_packets++; 667 u64_stats_update_end(&stats->tx_syncp); 668 669 dev_kfree_skb_any(skb); 670 } 671 } 672 673 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) 674 { 675 struct skb_vnet_hdr *hdr; 676 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 677 struct virtnet_info *vi = sq->vq->vdev->priv; 678 unsigned num_sg; 679 unsigned hdr_len; 680 bool can_push; 681 682 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 683 if (vi->mergeable_rx_bufs) 684 hdr_len = sizeof hdr->mhdr; 685 else 686 hdr_len = sizeof hdr->hdr; 687 688 can_push = vi->any_header_sg && 689 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) && 690 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len; 691 /* Even if we can, don't push here yet as this would skew 692 * csum_start offset below. */ 693 if (can_push) 694 hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len); 695 else 696 hdr = skb_vnet_hdr(skb); 697 698 if (skb->ip_summed == CHECKSUM_PARTIAL) { 699 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 700 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 701 hdr->hdr.csum_offset = skb->csum_offset; 702 } else { 703 hdr->hdr.flags = 0; 704 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 705 } 706 707 if (skb_is_gso(skb)) { 708 hdr->hdr.hdr_len = skb_headlen(skb); 709 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 710 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 711 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 712 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 713 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 714 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 715 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 716 else 717 BUG(); 718 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 719 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 720 } else { 721 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 722 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 723 } 724 725 if (vi->mergeable_rx_bufs) 726 hdr->mhdr.num_buffers = 0; 727 728 if (can_push) { 729 __skb_push(skb, hdr_len); 730 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len); 731 /* Pull header back to avoid skew in tx bytes calculations. */ 732 __skb_pull(skb, hdr_len); 733 } else { 734 sg_set_buf(sq->sg, hdr, hdr_len); 735 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1; 736 } 737 return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC); 738 } 739 740 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 741 { 742 struct virtnet_info *vi = netdev_priv(dev); 743 int qnum = skb_get_queue_mapping(skb); 744 struct send_queue *sq = &vi->sq[qnum]; 745 int err; 746 747 /* Free up any pending old buffers before queueing new ones. */ 748 free_old_xmit_skbs(sq); 749 750 /* Try to transmit */ 751 err = xmit_skb(sq, skb); 752 753 /* This should not happen! */ 754 if (unlikely(err)) { 755 dev->stats.tx_fifo_errors++; 756 if (net_ratelimit()) 757 dev_warn(&dev->dev, 758 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); 759 dev->stats.tx_dropped++; 760 kfree_skb(skb); 761 return NETDEV_TX_OK; 762 } 763 virtqueue_kick(sq->vq); 764 765 /* Don't wait up for transmitted skbs to be freed. */ 766 skb_orphan(skb); 767 nf_reset(skb); 768 769 /* Apparently nice girls don't return TX_BUSY; stop the queue 770 * before it gets out of hand. Naturally, this wastes entries. */ 771 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { 772 netif_stop_subqueue(dev, qnum); 773 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { 774 /* More just got used, free them then recheck. */ 775 free_old_xmit_skbs(sq); 776 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { 777 netif_start_subqueue(dev, qnum); 778 virtqueue_disable_cb(sq->vq); 779 } 780 } 781 } 782 783 return NETDEV_TX_OK; 784 } 785 786 /* 787 * Send command via the control virtqueue and check status. Commands 788 * supported by the hypervisor, as indicated by feature bits, should 789 * never fail unless improperly formated. 790 */ 791 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 792 struct scatterlist *out, 793 struct scatterlist *in) 794 { 795 struct scatterlist *sgs[4], hdr, stat; 796 struct virtio_net_ctrl_hdr ctrl; 797 virtio_net_ctrl_ack status = ~0; 798 unsigned out_num = 0, in_num = 0, tmp; 799 800 /* Caller should know better */ 801 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)); 802 803 ctrl.class = class; 804 ctrl.cmd = cmd; 805 /* Add header */ 806 sg_init_one(&hdr, &ctrl, sizeof(ctrl)); 807 sgs[out_num++] = &hdr; 808 809 if (out) 810 sgs[out_num++] = out; 811 if (in) 812 sgs[out_num + in_num++] = in; 813 814 /* Add return status. */ 815 sg_init_one(&stat, &status, sizeof(status)); 816 sgs[out_num + in_num++] = &stat; 817 818 BUG_ON(out_num + in_num > ARRAY_SIZE(sgs)); 819 BUG_ON(virtqueue_add_sgs(vi->cvq, sgs, out_num, in_num, vi, GFP_ATOMIC) 820 < 0); 821 822 virtqueue_kick(vi->cvq); 823 824 /* Spin for a response, the kick causes an ioport write, trapping 825 * into the hypervisor, so the request should be handled immediately. 826 */ 827 while (!virtqueue_get_buf(vi->cvq, &tmp)) 828 cpu_relax(); 829 830 return status == VIRTIO_NET_OK; 831 } 832 833 static int virtnet_set_mac_address(struct net_device *dev, void *p) 834 { 835 struct virtnet_info *vi = netdev_priv(dev); 836 struct virtio_device *vdev = vi->vdev; 837 int ret; 838 struct sockaddr *addr = p; 839 struct scatterlist sg; 840 841 ret = eth_prepare_mac_addr_change(dev, p); 842 if (ret) 843 return ret; 844 845 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) { 846 sg_init_one(&sg, addr->sa_data, dev->addr_len); 847 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 848 VIRTIO_NET_CTRL_MAC_ADDR_SET, 849 &sg, NULL)) { 850 dev_warn(&vdev->dev, 851 "Failed to set mac address by vq command.\n"); 852 return -EINVAL; 853 } 854 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 855 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 856 addr->sa_data, dev->addr_len); 857 } 858 859 eth_commit_mac_addr_change(dev, p); 860 861 return 0; 862 } 863 864 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 865 struct rtnl_link_stats64 *tot) 866 { 867 struct virtnet_info *vi = netdev_priv(dev); 868 int cpu; 869 unsigned int start; 870 871 for_each_possible_cpu(cpu) { 872 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); 873 u64 tpackets, tbytes, rpackets, rbytes; 874 875 do { 876 start = u64_stats_fetch_begin_bh(&stats->tx_syncp); 877 tpackets = stats->tx_packets; 878 tbytes = stats->tx_bytes; 879 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start)); 880 881 do { 882 start = u64_stats_fetch_begin_bh(&stats->rx_syncp); 883 rpackets = stats->rx_packets; 884 rbytes = stats->rx_bytes; 885 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start)); 886 887 tot->rx_packets += rpackets; 888 tot->tx_packets += tpackets; 889 tot->rx_bytes += rbytes; 890 tot->tx_bytes += tbytes; 891 } 892 893 tot->tx_dropped = dev->stats.tx_dropped; 894 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 895 tot->rx_dropped = dev->stats.rx_dropped; 896 tot->rx_length_errors = dev->stats.rx_length_errors; 897 tot->rx_frame_errors = dev->stats.rx_frame_errors; 898 899 return tot; 900 } 901 902 #ifdef CONFIG_NET_POLL_CONTROLLER 903 static void virtnet_netpoll(struct net_device *dev) 904 { 905 struct virtnet_info *vi = netdev_priv(dev); 906 int i; 907 908 for (i = 0; i < vi->curr_queue_pairs; i++) 909 napi_schedule(&vi->rq[i].napi); 910 } 911 #endif 912 913 static void virtnet_ack_link_announce(struct virtnet_info *vi) 914 { 915 rtnl_lock(); 916 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE, 917 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, NULL)) 918 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n"); 919 rtnl_unlock(); 920 } 921 922 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) 923 { 924 struct scatterlist sg; 925 struct virtio_net_ctrl_mq s; 926 struct net_device *dev = vi->dev; 927 928 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) 929 return 0; 930 931 s.virtqueue_pairs = queue_pairs; 932 sg_init_one(&sg, &s, sizeof(s)); 933 934 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ, 935 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, NULL)) { 936 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", 937 queue_pairs); 938 return -EINVAL; 939 } else { 940 vi->curr_queue_pairs = queue_pairs; 941 schedule_delayed_work(&vi->refill, 0); 942 } 943 944 return 0; 945 } 946 947 static int virtnet_close(struct net_device *dev) 948 { 949 struct virtnet_info *vi = netdev_priv(dev); 950 int i; 951 952 /* Make sure refill_work doesn't re-enable napi! */ 953 cancel_delayed_work_sync(&vi->refill); 954 955 for (i = 0; i < vi->max_queue_pairs; i++) 956 napi_disable(&vi->rq[i].napi); 957 958 return 0; 959 } 960 961 static void virtnet_set_rx_mode(struct net_device *dev) 962 { 963 struct virtnet_info *vi = netdev_priv(dev); 964 struct scatterlist sg[2]; 965 u8 promisc, allmulti; 966 struct virtio_net_ctrl_mac *mac_data; 967 struct netdev_hw_addr *ha; 968 int uc_count; 969 int mc_count; 970 void *buf; 971 int i; 972 973 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 974 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 975 return; 976 977 promisc = ((dev->flags & IFF_PROMISC) != 0); 978 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 979 980 sg_init_one(sg, &promisc, sizeof(promisc)); 981 982 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 983 VIRTIO_NET_CTRL_RX_PROMISC, 984 sg, NULL)) 985 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 986 promisc ? "en" : "dis"); 987 988 sg_init_one(sg, &allmulti, sizeof(allmulti)); 989 990 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 991 VIRTIO_NET_CTRL_RX_ALLMULTI, 992 sg, NULL)) 993 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 994 allmulti ? "en" : "dis"); 995 996 uc_count = netdev_uc_count(dev); 997 mc_count = netdev_mc_count(dev); 998 /* MAC filter - use one buffer for both lists */ 999 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 1000 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 1001 mac_data = buf; 1002 if (!buf) 1003 return; 1004 1005 sg_init_table(sg, 2); 1006 1007 /* Store the unicast list and count in the front of the buffer */ 1008 mac_data->entries = uc_count; 1009 i = 0; 1010 netdev_for_each_uc_addr(ha, dev) 1011 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 1012 1013 sg_set_buf(&sg[0], mac_data, 1014 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 1015 1016 /* multicast list and count fill the end */ 1017 mac_data = (void *)&mac_data->macs[uc_count][0]; 1018 1019 mac_data->entries = mc_count; 1020 i = 0; 1021 netdev_for_each_mc_addr(ha, dev) 1022 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 1023 1024 sg_set_buf(&sg[1], mac_data, 1025 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 1026 1027 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 1028 VIRTIO_NET_CTRL_MAC_TABLE_SET, 1029 sg, NULL)) 1030 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 1031 1032 kfree(buf); 1033 } 1034 1035 static int virtnet_vlan_rx_add_vid(struct net_device *dev, 1036 __be16 proto, u16 vid) 1037 { 1038 struct virtnet_info *vi = netdev_priv(dev); 1039 struct scatterlist sg; 1040 1041 sg_init_one(&sg, &vid, sizeof(vid)); 1042 1043 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1044 VIRTIO_NET_CTRL_VLAN_ADD, &sg, NULL)) 1045 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 1046 return 0; 1047 } 1048 1049 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, 1050 __be16 proto, u16 vid) 1051 { 1052 struct virtnet_info *vi = netdev_priv(dev); 1053 struct scatterlist sg; 1054 1055 sg_init_one(&sg, &vid, sizeof(vid)); 1056 1057 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1058 VIRTIO_NET_CTRL_VLAN_DEL, &sg, NULL)) 1059 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 1060 return 0; 1061 } 1062 1063 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu) 1064 { 1065 int i; 1066 int cpu; 1067 1068 if (vi->affinity_hint_set) { 1069 for (i = 0; i < vi->max_queue_pairs; i++) { 1070 virtqueue_set_affinity(vi->rq[i].vq, -1); 1071 virtqueue_set_affinity(vi->sq[i].vq, -1); 1072 } 1073 1074 vi->affinity_hint_set = false; 1075 } 1076 1077 i = 0; 1078 for_each_online_cpu(cpu) { 1079 if (cpu == hcpu) { 1080 *per_cpu_ptr(vi->vq_index, cpu) = -1; 1081 } else { 1082 *per_cpu_ptr(vi->vq_index, cpu) = 1083 ++i % vi->curr_queue_pairs; 1084 } 1085 } 1086 } 1087 1088 static void virtnet_set_affinity(struct virtnet_info *vi) 1089 { 1090 int i; 1091 int cpu; 1092 1093 /* In multiqueue mode, when the number of cpu is equal to the number of 1094 * queue pairs, we let the queue pairs to be private to one cpu by 1095 * setting the affinity hint to eliminate the contention. 1096 */ 1097 if (vi->curr_queue_pairs == 1 || 1098 vi->max_queue_pairs != num_online_cpus()) { 1099 virtnet_clean_affinity(vi, -1); 1100 return; 1101 } 1102 1103 i = 0; 1104 for_each_online_cpu(cpu) { 1105 virtqueue_set_affinity(vi->rq[i].vq, cpu); 1106 virtqueue_set_affinity(vi->sq[i].vq, cpu); 1107 *per_cpu_ptr(vi->vq_index, cpu) = i; 1108 i++; 1109 } 1110 1111 vi->affinity_hint_set = true; 1112 } 1113 1114 static int virtnet_cpu_callback(struct notifier_block *nfb, 1115 unsigned long action, void *hcpu) 1116 { 1117 struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb); 1118 1119 switch(action & ~CPU_TASKS_FROZEN) { 1120 case CPU_ONLINE: 1121 case CPU_DOWN_FAILED: 1122 case CPU_DEAD: 1123 virtnet_set_affinity(vi); 1124 break; 1125 case CPU_DOWN_PREPARE: 1126 virtnet_clean_affinity(vi, (long)hcpu); 1127 break; 1128 default: 1129 break; 1130 } 1131 return NOTIFY_OK; 1132 } 1133 1134 static void virtnet_get_ringparam(struct net_device *dev, 1135 struct ethtool_ringparam *ring) 1136 { 1137 struct virtnet_info *vi = netdev_priv(dev); 1138 1139 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq); 1140 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq); 1141 ring->rx_pending = ring->rx_max_pending; 1142 ring->tx_pending = ring->tx_max_pending; 1143 } 1144 1145 1146 static void virtnet_get_drvinfo(struct net_device *dev, 1147 struct ethtool_drvinfo *info) 1148 { 1149 struct virtnet_info *vi = netdev_priv(dev); 1150 struct virtio_device *vdev = vi->vdev; 1151 1152 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 1153 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 1154 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 1155 1156 } 1157 1158 /* TODO: Eliminate OOO packets during switching */ 1159 static int virtnet_set_channels(struct net_device *dev, 1160 struct ethtool_channels *channels) 1161 { 1162 struct virtnet_info *vi = netdev_priv(dev); 1163 u16 queue_pairs = channels->combined_count; 1164 int err; 1165 1166 /* We don't support separate rx/tx channels. 1167 * We don't allow setting 'other' channels. 1168 */ 1169 if (channels->rx_count || channels->tx_count || channels->other_count) 1170 return -EINVAL; 1171 1172 if (queue_pairs > vi->max_queue_pairs) 1173 return -EINVAL; 1174 1175 get_online_cpus(); 1176 err = virtnet_set_queues(vi, queue_pairs); 1177 if (!err) { 1178 netif_set_real_num_tx_queues(dev, queue_pairs); 1179 netif_set_real_num_rx_queues(dev, queue_pairs); 1180 1181 virtnet_set_affinity(vi); 1182 } 1183 put_online_cpus(); 1184 1185 return err; 1186 } 1187 1188 static void virtnet_get_channels(struct net_device *dev, 1189 struct ethtool_channels *channels) 1190 { 1191 struct virtnet_info *vi = netdev_priv(dev); 1192 1193 channels->combined_count = vi->curr_queue_pairs; 1194 channels->max_combined = vi->max_queue_pairs; 1195 channels->max_other = 0; 1196 channels->rx_count = 0; 1197 channels->tx_count = 0; 1198 channels->other_count = 0; 1199 } 1200 1201 static const struct ethtool_ops virtnet_ethtool_ops = { 1202 .get_drvinfo = virtnet_get_drvinfo, 1203 .get_link = ethtool_op_get_link, 1204 .get_ringparam = virtnet_get_ringparam, 1205 .set_channels = virtnet_set_channels, 1206 .get_channels = virtnet_get_channels, 1207 }; 1208 1209 #define MIN_MTU 68 1210 #define MAX_MTU 65535 1211 1212 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 1213 { 1214 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 1215 return -EINVAL; 1216 dev->mtu = new_mtu; 1217 return 0; 1218 } 1219 1220 /* To avoid contending a lock hold by a vcpu who would exit to host, select the 1221 * txq based on the processor id. 1222 */ 1223 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb) 1224 { 1225 int txq; 1226 struct virtnet_info *vi = netdev_priv(dev); 1227 1228 if (skb_rx_queue_recorded(skb)) { 1229 txq = skb_get_rx_queue(skb); 1230 } else { 1231 txq = *__this_cpu_ptr(vi->vq_index); 1232 if (txq == -1) 1233 txq = 0; 1234 } 1235 1236 while (unlikely(txq >= dev->real_num_tx_queues)) 1237 txq -= dev->real_num_tx_queues; 1238 1239 return txq; 1240 } 1241 1242 static const struct net_device_ops virtnet_netdev = { 1243 .ndo_open = virtnet_open, 1244 .ndo_stop = virtnet_close, 1245 .ndo_start_xmit = start_xmit, 1246 .ndo_validate_addr = eth_validate_addr, 1247 .ndo_set_mac_address = virtnet_set_mac_address, 1248 .ndo_set_rx_mode = virtnet_set_rx_mode, 1249 .ndo_change_mtu = virtnet_change_mtu, 1250 .ndo_get_stats64 = virtnet_stats, 1251 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 1252 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 1253 .ndo_select_queue = virtnet_select_queue, 1254 #ifdef CONFIG_NET_POLL_CONTROLLER 1255 .ndo_poll_controller = virtnet_netpoll, 1256 #endif 1257 }; 1258 1259 static void virtnet_config_changed_work(struct work_struct *work) 1260 { 1261 struct virtnet_info *vi = 1262 container_of(work, struct virtnet_info, config_work); 1263 u16 v; 1264 1265 mutex_lock(&vi->config_lock); 1266 if (!vi->config_enable) 1267 goto done; 1268 1269 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS, 1270 offsetof(struct virtio_net_config, status), 1271 &v) < 0) 1272 goto done; 1273 1274 if (v & VIRTIO_NET_S_ANNOUNCE) { 1275 netdev_notify_peers(vi->dev); 1276 virtnet_ack_link_announce(vi); 1277 } 1278 1279 /* Ignore unknown (future) status bits */ 1280 v &= VIRTIO_NET_S_LINK_UP; 1281 1282 if (vi->status == v) 1283 goto done; 1284 1285 vi->status = v; 1286 1287 if (vi->status & VIRTIO_NET_S_LINK_UP) { 1288 netif_carrier_on(vi->dev); 1289 netif_tx_wake_all_queues(vi->dev); 1290 } else { 1291 netif_carrier_off(vi->dev); 1292 netif_tx_stop_all_queues(vi->dev); 1293 } 1294 done: 1295 mutex_unlock(&vi->config_lock); 1296 } 1297 1298 static void virtnet_config_changed(struct virtio_device *vdev) 1299 { 1300 struct virtnet_info *vi = vdev->priv; 1301 1302 schedule_work(&vi->config_work); 1303 } 1304 1305 static void virtnet_free_queues(struct virtnet_info *vi) 1306 { 1307 kfree(vi->rq); 1308 kfree(vi->sq); 1309 } 1310 1311 static void free_receive_bufs(struct virtnet_info *vi) 1312 { 1313 int i; 1314 1315 for (i = 0; i < vi->max_queue_pairs; i++) { 1316 while (vi->rq[i].pages) 1317 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0); 1318 } 1319 } 1320 1321 static void free_unused_bufs(struct virtnet_info *vi) 1322 { 1323 void *buf; 1324 int i; 1325 1326 for (i = 0; i < vi->max_queue_pairs; i++) { 1327 struct virtqueue *vq = vi->sq[i].vq; 1328 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) 1329 dev_kfree_skb(buf); 1330 } 1331 1332 for (i = 0; i < vi->max_queue_pairs; i++) { 1333 struct virtqueue *vq = vi->rq[i].vq; 1334 1335 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { 1336 if (vi->mergeable_rx_bufs || vi->big_packets) 1337 give_pages(&vi->rq[i], buf); 1338 else 1339 dev_kfree_skb(buf); 1340 --vi->rq[i].num; 1341 } 1342 BUG_ON(vi->rq[i].num != 0); 1343 } 1344 } 1345 1346 static void virtnet_del_vqs(struct virtnet_info *vi) 1347 { 1348 struct virtio_device *vdev = vi->vdev; 1349 1350 virtnet_clean_affinity(vi, -1); 1351 1352 vdev->config->del_vqs(vdev); 1353 1354 virtnet_free_queues(vi); 1355 } 1356 1357 static int virtnet_find_vqs(struct virtnet_info *vi) 1358 { 1359 vq_callback_t **callbacks; 1360 struct virtqueue **vqs; 1361 int ret = -ENOMEM; 1362 int i, total_vqs; 1363 const char **names; 1364 1365 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by 1366 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by 1367 * possible control vq. 1368 */ 1369 total_vqs = vi->max_queue_pairs * 2 + 1370 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); 1371 1372 /* Allocate space for find_vqs parameters */ 1373 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); 1374 if (!vqs) 1375 goto err_vq; 1376 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); 1377 if (!callbacks) 1378 goto err_callback; 1379 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); 1380 if (!names) 1381 goto err_names; 1382 1383 /* Parameters for control virtqueue, if any */ 1384 if (vi->has_cvq) { 1385 callbacks[total_vqs - 1] = NULL; 1386 names[total_vqs - 1] = "control"; 1387 } 1388 1389 /* Allocate/initialize parameters for send/receive virtqueues */ 1390 for (i = 0; i < vi->max_queue_pairs; i++) { 1391 callbacks[rxq2vq(i)] = skb_recv_done; 1392 callbacks[txq2vq(i)] = skb_xmit_done; 1393 sprintf(vi->rq[i].name, "input.%d", i); 1394 sprintf(vi->sq[i].name, "output.%d", i); 1395 names[rxq2vq(i)] = vi->rq[i].name; 1396 names[txq2vq(i)] = vi->sq[i].name; 1397 } 1398 1399 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, 1400 names); 1401 if (ret) 1402 goto err_find; 1403 1404 if (vi->has_cvq) { 1405 vi->cvq = vqs[total_vqs - 1]; 1406 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1407 vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER; 1408 } 1409 1410 for (i = 0; i < vi->max_queue_pairs; i++) { 1411 vi->rq[i].vq = vqs[rxq2vq(i)]; 1412 vi->sq[i].vq = vqs[txq2vq(i)]; 1413 } 1414 1415 kfree(names); 1416 kfree(callbacks); 1417 kfree(vqs); 1418 1419 return 0; 1420 1421 err_find: 1422 kfree(names); 1423 err_names: 1424 kfree(callbacks); 1425 err_callback: 1426 kfree(vqs); 1427 err_vq: 1428 return ret; 1429 } 1430 1431 static int virtnet_alloc_queues(struct virtnet_info *vi) 1432 { 1433 int i; 1434 1435 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL); 1436 if (!vi->sq) 1437 goto err_sq; 1438 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL); 1439 if (!vi->rq) 1440 goto err_rq; 1441 1442 INIT_DELAYED_WORK(&vi->refill, refill_work); 1443 for (i = 0; i < vi->max_queue_pairs; i++) { 1444 vi->rq[i].pages = NULL; 1445 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll, 1446 napi_weight); 1447 1448 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); 1449 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); 1450 } 1451 1452 return 0; 1453 1454 err_rq: 1455 kfree(vi->sq); 1456 err_sq: 1457 return -ENOMEM; 1458 } 1459 1460 static int init_vqs(struct virtnet_info *vi) 1461 { 1462 int ret; 1463 1464 /* Allocate send & receive queues */ 1465 ret = virtnet_alloc_queues(vi); 1466 if (ret) 1467 goto err; 1468 1469 ret = virtnet_find_vqs(vi); 1470 if (ret) 1471 goto err_free; 1472 1473 get_online_cpus(); 1474 virtnet_set_affinity(vi); 1475 put_online_cpus(); 1476 1477 return 0; 1478 1479 err_free: 1480 virtnet_free_queues(vi); 1481 err: 1482 return ret; 1483 } 1484 1485 static int virtnet_probe(struct virtio_device *vdev) 1486 { 1487 int i, err; 1488 struct net_device *dev; 1489 struct virtnet_info *vi; 1490 u16 max_queue_pairs; 1491 1492 /* Find if host supports multiqueue virtio_net device */ 1493 err = virtio_config_val(vdev, VIRTIO_NET_F_MQ, 1494 offsetof(struct virtio_net_config, 1495 max_virtqueue_pairs), &max_queue_pairs); 1496 1497 /* We need at least 2 queue's */ 1498 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN || 1499 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX || 1500 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1501 max_queue_pairs = 1; 1502 1503 /* Allocate ourselves a network device with room for our info */ 1504 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); 1505 if (!dev) 1506 return -ENOMEM; 1507 1508 /* Set up network device as normal. */ 1509 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE; 1510 dev->netdev_ops = &virtnet_netdev; 1511 dev->features = NETIF_F_HIGHDMA; 1512 1513 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 1514 SET_NETDEV_DEV(dev, &vdev->dev); 1515 1516 /* Do we support "hardware" checksums? */ 1517 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 1518 /* This opens up the world of extra features. */ 1519 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1520 if (csum) 1521 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1522 1523 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 1524 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 1525 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 1526 } 1527 /* Individual feature bits: what can host handle? */ 1528 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 1529 dev->hw_features |= NETIF_F_TSO; 1530 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 1531 dev->hw_features |= NETIF_F_TSO6; 1532 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 1533 dev->hw_features |= NETIF_F_TSO_ECN; 1534 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1535 dev->hw_features |= NETIF_F_UFO; 1536 1537 if (gso) 1538 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1539 /* (!csum && gso) case will be fixed by register_netdev() */ 1540 } 1541 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM)) 1542 dev->features |= NETIF_F_RXCSUM; 1543 1544 dev->vlan_features = dev->features; 1545 1546 /* Configuration may specify what MAC to use. Otherwise random. */ 1547 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC, 1548 offsetof(struct virtio_net_config, mac), 1549 dev->dev_addr, dev->addr_len) < 0) 1550 eth_hw_addr_random(dev); 1551 1552 /* Set up our device-specific information */ 1553 vi = netdev_priv(dev); 1554 vi->dev = dev; 1555 vi->vdev = vdev; 1556 vdev->priv = vi; 1557 vi->stats = alloc_percpu(struct virtnet_stats); 1558 err = -ENOMEM; 1559 if (vi->stats == NULL) 1560 goto free; 1561 1562 vi->vq_index = alloc_percpu(int); 1563 if (vi->vq_index == NULL) 1564 goto free_stats; 1565 1566 mutex_init(&vi->config_lock); 1567 vi->config_enable = true; 1568 INIT_WORK(&vi->config_work, virtnet_config_changed_work); 1569 1570 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1571 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1572 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1573 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1574 vi->big_packets = true; 1575 1576 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1577 vi->mergeable_rx_bufs = true; 1578 1579 if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) 1580 vi->any_header_sg = true; 1581 1582 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1583 vi->has_cvq = true; 1584 1585 /* Use single tx/rx queue pair as default */ 1586 vi->curr_queue_pairs = 1; 1587 vi->max_queue_pairs = max_queue_pairs; 1588 1589 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ 1590 err = init_vqs(vi); 1591 if (err) 1592 goto free_index; 1593 1594 netif_set_real_num_tx_queues(dev, 1); 1595 netif_set_real_num_rx_queues(dev, 1); 1596 1597 err = register_netdev(dev); 1598 if (err) { 1599 pr_debug("virtio_net: registering device failed\n"); 1600 goto free_vqs; 1601 } 1602 1603 /* Last of all, set up some receive buffers. */ 1604 for (i = 0; i < vi->curr_queue_pairs; i++) { 1605 try_fill_recv(&vi->rq[i], GFP_KERNEL); 1606 1607 /* If we didn't even get one input buffer, we're useless. */ 1608 if (vi->rq[i].num == 0) { 1609 free_unused_bufs(vi); 1610 err = -ENOMEM; 1611 goto free_recv_bufs; 1612 } 1613 } 1614 1615 vi->nb.notifier_call = &virtnet_cpu_callback; 1616 err = register_hotcpu_notifier(&vi->nb); 1617 if (err) { 1618 pr_debug("virtio_net: registering cpu notifier failed\n"); 1619 goto free_recv_bufs; 1620 } 1621 1622 /* Assume link up if device can't report link status, 1623 otherwise get link status from config. */ 1624 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1625 netif_carrier_off(dev); 1626 schedule_work(&vi->config_work); 1627 } else { 1628 vi->status = VIRTIO_NET_S_LINK_UP; 1629 netif_carrier_on(dev); 1630 } 1631 1632 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", 1633 dev->name, max_queue_pairs); 1634 1635 return 0; 1636 1637 free_recv_bufs: 1638 free_receive_bufs(vi); 1639 unregister_netdev(dev); 1640 free_vqs: 1641 cancel_delayed_work_sync(&vi->refill); 1642 virtnet_del_vqs(vi); 1643 free_index: 1644 free_percpu(vi->vq_index); 1645 free_stats: 1646 free_percpu(vi->stats); 1647 free: 1648 free_netdev(dev); 1649 return err; 1650 } 1651 1652 static void remove_vq_common(struct virtnet_info *vi) 1653 { 1654 vi->vdev->config->reset(vi->vdev); 1655 1656 /* Free unused buffers in both send and recv, if any. */ 1657 free_unused_bufs(vi); 1658 1659 free_receive_bufs(vi); 1660 1661 virtnet_del_vqs(vi); 1662 } 1663 1664 static void virtnet_remove(struct virtio_device *vdev) 1665 { 1666 struct virtnet_info *vi = vdev->priv; 1667 1668 unregister_hotcpu_notifier(&vi->nb); 1669 1670 /* Prevent config work handler from accessing the device. */ 1671 mutex_lock(&vi->config_lock); 1672 vi->config_enable = false; 1673 mutex_unlock(&vi->config_lock); 1674 1675 unregister_netdev(vi->dev); 1676 1677 remove_vq_common(vi); 1678 1679 flush_work(&vi->config_work); 1680 1681 free_percpu(vi->vq_index); 1682 free_percpu(vi->stats); 1683 free_netdev(vi->dev); 1684 } 1685 1686 #ifdef CONFIG_PM 1687 static int virtnet_freeze(struct virtio_device *vdev) 1688 { 1689 struct virtnet_info *vi = vdev->priv; 1690 int i; 1691 1692 /* Prevent config work handler from accessing the device */ 1693 mutex_lock(&vi->config_lock); 1694 vi->config_enable = false; 1695 mutex_unlock(&vi->config_lock); 1696 1697 netif_device_detach(vi->dev); 1698 cancel_delayed_work_sync(&vi->refill); 1699 1700 if (netif_running(vi->dev)) 1701 for (i = 0; i < vi->max_queue_pairs; i++) { 1702 napi_disable(&vi->rq[i].napi); 1703 netif_napi_del(&vi->rq[i].napi); 1704 } 1705 1706 remove_vq_common(vi); 1707 1708 flush_work(&vi->config_work); 1709 1710 return 0; 1711 } 1712 1713 static int virtnet_restore(struct virtio_device *vdev) 1714 { 1715 struct virtnet_info *vi = vdev->priv; 1716 int err, i; 1717 1718 err = init_vqs(vi); 1719 if (err) 1720 return err; 1721 1722 if (netif_running(vi->dev)) 1723 for (i = 0; i < vi->max_queue_pairs; i++) 1724 virtnet_napi_enable(&vi->rq[i]); 1725 1726 netif_device_attach(vi->dev); 1727 1728 for (i = 0; i < vi->curr_queue_pairs; i++) 1729 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 1730 schedule_delayed_work(&vi->refill, 0); 1731 1732 mutex_lock(&vi->config_lock); 1733 vi->config_enable = true; 1734 mutex_unlock(&vi->config_lock); 1735 1736 virtnet_set_queues(vi, vi->curr_queue_pairs); 1737 1738 return 0; 1739 } 1740 #endif 1741 1742 static struct virtio_device_id id_table[] = { 1743 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1744 { 0 }, 1745 }; 1746 1747 static unsigned int features[] = { 1748 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1749 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1750 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1751 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1752 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1753 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1754 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1755 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, 1756 VIRTIO_NET_F_CTRL_MAC_ADDR, 1757 VIRTIO_F_ANY_LAYOUT, 1758 }; 1759 1760 static struct virtio_driver virtio_net_driver = { 1761 .feature_table = features, 1762 .feature_table_size = ARRAY_SIZE(features), 1763 .driver.name = KBUILD_MODNAME, 1764 .driver.owner = THIS_MODULE, 1765 .id_table = id_table, 1766 .probe = virtnet_probe, 1767 .remove = virtnet_remove, 1768 .config_changed = virtnet_config_changed, 1769 #ifdef CONFIG_PM 1770 .freeze = virtnet_freeze, 1771 .restore = virtnet_restore, 1772 #endif 1773 }; 1774 1775 module_virtio_driver(virtio_net_driver); 1776 1777 MODULE_DEVICE_TABLE(virtio, id_table); 1778 MODULE_DESCRIPTION("Virtio network driver"); 1779 MODULE_LICENSE("GPL"); 1780