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