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 = 128; 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_SEND_COMMAND_SG_MAX 2 43 #define VIRTNET_DRIVER_VERSION "1.0.0" 44 45 struct virtnet_stats { 46 struct u64_stats_sync tx_syncp; 47 struct u64_stats_sync rx_syncp; 48 u64 tx_bytes; 49 u64 tx_packets; 50 51 u64 rx_bytes; 52 u64 rx_packets; 53 }; 54 55 /* Internal representation of a send virtqueue */ 56 struct send_queue { 57 /* Virtqueue associated with this send _queue */ 58 struct virtqueue *vq; 59 60 /* TX: fragments + linear part + virtio header */ 61 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 62 63 /* Name of the send queue: output.$index */ 64 char name[40]; 65 }; 66 67 /* Internal representation of a receive virtqueue */ 68 struct receive_queue { 69 /* Virtqueue associated with this receive_queue */ 70 struct virtqueue *vq; 71 72 struct napi_struct napi; 73 74 /* Number of input buffers, and max we've ever had. */ 75 unsigned int num, max; 76 77 /* Chain pages by the private ptr. */ 78 struct page *pages; 79 80 /* RX: fragments + linear part + virtio header */ 81 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 82 83 /* Name of this receive queue: input.$index */ 84 char name[40]; 85 }; 86 87 struct virtnet_info { 88 struct virtio_device *vdev; 89 struct virtqueue *cvq; 90 struct net_device *dev; 91 struct send_queue *sq; 92 struct receive_queue *rq; 93 unsigned int status; 94 95 /* Max # of queue pairs supported by the device */ 96 u16 max_queue_pairs; 97 98 /* # of queue pairs currently used by the driver */ 99 u16 curr_queue_pairs; 100 101 /* I like... big packets and I cannot lie! */ 102 bool big_packets; 103 104 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 105 bool mergeable_rx_bufs; 106 107 /* Has control virtqueue */ 108 bool has_cvq; 109 110 /* enable config space updates */ 111 bool config_enable; 112 113 /* Active statistics */ 114 struct virtnet_stats __percpu *stats; 115 116 /* Work struct for refilling if we run low on memory. */ 117 struct delayed_work refill; 118 119 /* Work struct for config space updates */ 120 struct work_struct config_work; 121 122 /* Lock for config space updates */ 123 struct mutex config_lock; 124 125 /* Does the affinity hint is set for virtqueues? */ 126 bool affinity_hint_set; 127 128 /* Per-cpu variable to show the mapping from CPU to virtqueue */ 129 int __percpu *vq_index; 130 131 /* CPU hot plug notifier */ 132 struct notifier_block nb; 133 }; 134 135 struct skb_vnet_hdr { 136 union { 137 struct virtio_net_hdr hdr; 138 struct virtio_net_hdr_mrg_rxbuf mhdr; 139 }; 140 }; 141 142 struct padded_vnet_hdr { 143 struct virtio_net_hdr hdr; 144 /* 145 * virtio_net_hdr should be in a separated sg buffer because of a 146 * QEMU bug, and data sg buffer shares same page with this header sg. 147 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 148 */ 149 char padding[6]; 150 }; 151 152 /* Converting between virtqueue no. and kernel tx/rx queue no. 153 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq 154 */ 155 static int vq2txq(struct virtqueue *vq) 156 { 157 return (virtqueue_get_queue_index(vq) - 1) / 2; 158 } 159 160 static int txq2vq(int txq) 161 { 162 return txq * 2 + 1; 163 } 164 165 static int vq2rxq(struct virtqueue *vq) 166 { 167 return virtqueue_get_queue_index(vq) / 2; 168 } 169 170 static int rxq2vq(int rxq) 171 { 172 return rxq * 2; 173 } 174 175 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 176 { 177 return (struct skb_vnet_hdr *)skb->cb; 178 } 179 180 /* 181 * private is used to chain pages for big packets, put the whole 182 * most recent used list in the beginning for reuse 183 */ 184 static void give_pages(struct receive_queue *rq, struct page *page) 185 { 186 struct page *end; 187 188 /* Find end of list, sew whole thing into vi->rq.pages. */ 189 for (end = page; end->private; end = (struct page *)end->private); 190 end->private = (unsigned long)rq->pages; 191 rq->pages = page; 192 } 193 194 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) 195 { 196 struct page *p = rq->pages; 197 198 if (p) { 199 rq->pages = (struct page *)p->private; 200 /* clear private here, it is used to chain pages */ 201 p->private = 0; 202 } else 203 p = alloc_page(gfp_mask); 204 return p; 205 } 206 207 static void skb_xmit_done(struct virtqueue *vq) 208 { 209 struct virtnet_info *vi = vq->vdev->priv; 210 211 /* Suppress further interrupts. */ 212 virtqueue_disable_cb(vq); 213 214 /* We were probably waiting for more output buffers. */ 215 netif_wake_subqueue(vi->dev, vq2txq(vq)); 216 } 217 218 static void set_skb_frag(struct sk_buff *skb, struct page *page, 219 unsigned int offset, unsigned int *len) 220 { 221 int size = min((unsigned)PAGE_SIZE - offset, *len); 222 int i = skb_shinfo(skb)->nr_frags; 223 224 __skb_fill_page_desc(skb, i, page, offset, size); 225 226 skb->data_len += size; 227 skb->len += size; 228 skb->truesize += PAGE_SIZE; 229 skb_shinfo(skb)->nr_frags++; 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_buf(rq->vq, rq->sg, 0, 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_buf(rq->vq, rq->sg, 0, 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_buf(rq->vq, rq->sg, 0, 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->max_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->max_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_buf(sq->vq, sq->sg, num_sg, 714 0, skb, GFP_ATOMIC); 715 } 716 717 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 718 { 719 struct virtnet_info *vi = netdev_priv(dev); 720 int qnum = skb_get_queue_mapping(skb); 721 struct send_queue *sq = &vi->sq[qnum]; 722 int err; 723 724 /* Free up any pending old buffers before queueing new ones. */ 725 free_old_xmit_skbs(sq); 726 727 /* Try to transmit */ 728 err = xmit_skb(sq, skb); 729 730 /* This should not happen! */ 731 if (unlikely(err)) { 732 dev->stats.tx_fifo_errors++; 733 if (net_ratelimit()) 734 dev_warn(&dev->dev, 735 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); 736 dev->stats.tx_dropped++; 737 kfree_skb(skb); 738 return NETDEV_TX_OK; 739 } 740 virtqueue_kick(sq->vq); 741 742 /* Don't wait up for transmitted skbs to be freed. */ 743 skb_orphan(skb); 744 nf_reset(skb); 745 746 /* Apparently nice girls don't return TX_BUSY; stop the queue 747 * before it gets out of hand. Naturally, this wastes entries. */ 748 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { 749 netif_stop_subqueue(dev, qnum); 750 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { 751 /* More just got used, free them then recheck. */ 752 free_old_xmit_skbs(sq); 753 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { 754 netif_start_subqueue(dev, qnum); 755 virtqueue_disable_cb(sq->vq); 756 } 757 } 758 } 759 760 return NETDEV_TX_OK; 761 } 762 763 static int virtnet_set_mac_address(struct net_device *dev, void *p) 764 { 765 struct virtnet_info *vi = netdev_priv(dev); 766 struct virtio_device *vdev = vi->vdev; 767 int ret; 768 769 ret = eth_mac_addr(dev, p); 770 if (ret) 771 return ret; 772 773 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 774 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 775 dev->dev_addr, dev->addr_len); 776 777 return 0; 778 } 779 780 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 781 struct rtnl_link_stats64 *tot) 782 { 783 struct virtnet_info *vi = netdev_priv(dev); 784 int cpu; 785 unsigned int start; 786 787 for_each_possible_cpu(cpu) { 788 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); 789 u64 tpackets, tbytes, rpackets, rbytes; 790 791 do { 792 start = u64_stats_fetch_begin_bh(&stats->tx_syncp); 793 tpackets = stats->tx_packets; 794 tbytes = stats->tx_bytes; 795 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start)); 796 797 do { 798 start = u64_stats_fetch_begin_bh(&stats->rx_syncp); 799 rpackets = stats->rx_packets; 800 rbytes = stats->rx_bytes; 801 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start)); 802 803 tot->rx_packets += rpackets; 804 tot->tx_packets += tpackets; 805 tot->rx_bytes += rbytes; 806 tot->tx_bytes += tbytes; 807 } 808 809 tot->tx_dropped = dev->stats.tx_dropped; 810 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 811 tot->rx_dropped = dev->stats.rx_dropped; 812 tot->rx_length_errors = dev->stats.rx_length_errors; 813 tot->rx_frame_errors = dev->stats.rx_frame_errors; 814 815 return tot; 816 } 817 818 #ifdef CONFIG_NET_POLL_CONTROLLER 819 static void virtnet_netpoll(struct net_device *dev) 820 { 821 struct virtnet_info *vi = netdev_priv(dev); 822 int i; 823 824 for (i = 0; i < vi->curr_queue_pairs; i++) 825 napi_schedule(&vi->rq[i].napi); 826 } 827 #endif 828 829 /* 830 * Send command via the control virtqueue and check status. Commands 831 * supported by the hypervisor, as indicated by feature bits, should 832 * never fail unless improperly formated. 833 */ 834 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 835 struct scatterlist *data, int out, int in) 836 { 837 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 838 struct virtio_net_ctrl_hdr ctrl; 839 virtio_net_ctrl_ack status = ~0; 840 unsigned int tmp; 841 int i; 842 843 /* Caller should know better */ 844 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 845 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 846 847 out++; /* Add header */ 848 in++; /* Add return status */ 849 850 ctrl.class = class; 851 ctrl.cmd = cmd; 852 853 sg_init_table(sg, out + in); 854 855 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 856 for_each_sg(data, s, out + in - 2, i) 857 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 858 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 859 860 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0); 861 862 virtqueue_kick(vi->cvq); 863 864 /* 865 * Spin for a response, the kick causes an ioport write, trapping 866 * into the hypervisor, so the request should be handled immediately. 867 */ 868 while (!virtqueue_get_buf(vi->cvq, &tmp)) 869 cpu_relax(); 870 871 return status == VIRTIO_NET_OK; 872 } 873 874 static void virtnet_ack_link_announce(struct virtnet_info *vi) 875 { 876 rtnl_lock(); 877 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE, 878 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, 879 0, 0)) 880 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n"); 881 rtnl_unlock(); 882 } 883 884 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) 885 { 886 struct scatterlist sg; 887 struct virtio_net_ctrl_mq s; 888 struct net_device *dev = vi->dev; 889 890 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) 891 return 0; 892 893 s.virtqueue_pairs = queue_pairs; 894 sg_init_one(&sg, &s, sizeof(s)); 895 896 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ, 897 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){ 898 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", 899 queue_pairs); 900 return -EINVAL; 901 } else 902 vi->curr_queue_pairs = queue_pairs; 903 904 return 0; 905 } 906 907 static int virtnet_close(struct net_device *dev) 908 { 909 struct virtnet_info *vi = netdev_priv(dev); 910 int i; 911 912 /* Make sure refill_work doesn't re-enable napi! */ 913 cancel_delayed_work_sync(&vi->refill); 914 915 for (i = 0; i < vi->max_queue_pairs; i++) 916 napi_disable(&vi->rq[i].napi); 917 918 return 0; 919 } 920 921 static void virtnet_set_rx_mode(struct net_device *dev) 922 { 923 struct virtnet_info *vi = netdev_priv(dev); 924 struct scatterlist sg[2]; 925 u8 promisc, allmulti; 926 struct virtio_net_ctrl_mac *mac_data; 927 struct netdev_hw_addr *ha; 928 int uc_count; 929 int mc_count; 930 void *buf; 931 int i; 932 933 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 934 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 935 return; 936 937 promisc = ((dev->flags & IFF_PROMISC) != 0); 938 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 939 940 sg_init_one(sg, &promisc, sizeof(promisc)); 941 942 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 943 VIRTIO_NET_CTRL_RX_PROMISC, 944 sg, 1, 0)) 945 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 946 promisc ? "en" : "dis"); 947 948 sg_init_one(sg, &allmulti, sizeof(allmulti)); 949 950 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 951 VIRTIO_NET_CTRL_RX_ALLMULTI, 952 sg, 1, 0)) 953 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 954 allmulti ? "en" : "dis"); 955 956 uc_count = netdev_uc_count(dev); 957 mc_count = netdev_mc_count(dev); 958 /* MAC filter - use one buffer for both lists */ 959 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 960 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 961 mac_data = buf; 962 if (!buf) { 963 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 964 return; 965 } 966 967 sg_init_table(sg, 2); 968 969 /* Store the unicast list and count in the front of the buffer */ 970 mac_data->entries = uc_count; 971 i = 0; 972 netdev_for_each_uc_addr(ha, dev) 973 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 974 975 sg_set_buf(&sg[0], mac_data, 976 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 977 978 /* multicast list and count fill the end */ 979 mac_data = (void *)&mac_data->macs[uc_count][0]; 980 981 mac_data->entries = mc_count; 982 i = 0; 983 netdev_for_each_mc_addr(ha, dev) 984 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 985 986 sg_set_buf(&sg[1], mac_data, 987 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 988 989 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 990 VIRTIO_NET_CTRL_MAC_TABLE_SET, 991 sg, 2, 0)) 992 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 993 994 kfree(buf); 995 } 996 997 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 998 { 999 struct virtnet_info *vi = netdev_priv(dev); 1000 struct scatterlist sg; 1001 1002 sg_init_one(&sg, &vid, sizeof(vid)); 1003 1004 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1005 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 1006 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 1007 return 0; 1008 } 1009 1010 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 1011 { 1012 struct virtnet_info *vi = netdev_priv(dev); 1013 struct scatterlist sg; 1014 1015 sg_init_one(&sg, &vid, sizeof(vid)); 1016 1017 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1018 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 1019 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 1020 return 0; 1021 } 1022 1023 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu) 1024 { 1025 int i; 1026 int cpu; 1027 1028 if (vi->affinity_hint_set) { 1029 for (i = 0; i < vi->max_queue_pairs; i++) { 1030 virtqueue_set_affinity(vi->rq[i].vq, -1); 1031 virtqueue_set_affinity(vi->sq[i].vq, -1); 1032 } 1033 1034 vi->affinity_hint_set = false; 1035 } 1036 1037 i = 0; 1038 for_each_online_cpu(cpu) { 1039 if (cpu == hcpu) { 1040 *per_cpu_ptr(vi->vq_index, cpu) = -1; 1041 } else { 1042 *per_cpu_ptr(vi->vq_index, cpu) = 1043 ++i % vi->curr_queue_pairs; 1044 } 1045 } 1046 } 1047 1048 static void virtnet_set_affinity(struct virtnet_info *vi) 1049 { 1050 int i; 1051 int cpu; 1052 1053 /* In multiqueue mode, when the number of cpu is equal to the number of 1054 * queue pairs, we let the queue pairs to be private to one cpu by 1055 * setting the affinity hint to eliminate the contention. 1056 */ 1057 if (vi->curr_queue_pairs == 1 || 1058 vi->max_queue_pairs != num_online_cpus()) { 1059 virtnet_clean_affinity(vi, -1); 1060 return; 1061 } 1062 1063 i = 0; 1064 for_each_online_cpu(cpu) { 1065 virtqueue_set_affinity(vi->rq[i].vq, cpu); 1066 virtqueue_set_affinity(vi->sq[i].vq, cpu); 1067 *per_cpu_ptr(vi->vq_index, cpu) = i; 1068 i++; 1069 } 1070 1071 vi->affinity_hint_set = true; 1072 } 1073 1074 static int virtnet_cpu_callback(struct notifier_block *nfb, 1075 unsigned long action, void *hcpu) 1076 { 1077 struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb); 1078 1079 switch(action & ~CPU_TASKS_FROZEN) { 1080 case CPU_ONLINE: 1081 case CPU_DOWN_FAILED: 1082 case CPU_DEAD: 1083 virtnet_set_affinity(vi); 1084 break; 1085 case CPU_DOWN_PREPARE: 1086 virtnet_clean_affinity(vi, (long)hcpu); 1087 break; 1088 default: 1089 break; 1090 } 1091 return NOTIFY_OK; 1092 } 1093 1094 static void virtnet_get_ringparam(struct net_device *dev, 1095 struct ethtool_ringparam *ring) 1096 { 1097 struct virtnet_info *vi = netdev_priv(dev); 1098 1099 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq); 1100 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq); 1101 ring->rx_pending = ring->rx_max_pending; 1102 ring->tx_pending = ring->tx_max_pending; 1103 } 1104 1105 1106 static void virtnet_get_drvinfo(struct net_device *dev, 1107 struct ethtool_drvinfo *info) 1108 { 1109 struct virtnet_info *vi = netdev_priv(dev); 1110 struct virtio_device *vdev = vi->vdev; 1111 1112 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 1113 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 1114 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 1115 1116 } 1117 1118 /* TODO: Eliminate OOO packets during switching */ 1119 static int virtnet_set_channels(struct net_device *dev, 1120 struct ethtool_channels *channels) 1121 { 1122 struct virtnet_info *vi = netdev_priv(dev); 1123 u16 queue_pairs = channels->combined_count; 1124 int err; 1125 1126 /* We don't support separate rx/tx channels. 1127 * We don't allow setting 'other' channels. 1128 */ 1129 if (channels->rx_count || channels->tx_count || channels->other_count) 1130 return -EINVAL; 1131 1132 if (queue_pairs > vi->max_queue_pairs) 1133 return -EINVAL; 1134 1135 get_online_cpus(); 1136 err = virtnet_set_queues(vi, queue_pairs); 1137 if (!err) { 1138 netif_set_real_num_tx_queues(dev, queue_pairs); 1139 netif_set_real_num_rx_queues(dev, queue_pairs); 1140 1141 virtnet_set_affinity(vi); 1142 } 1143 put_online_cpus(); 1144 1145 return err; 1146 } 1147 1148 static void virtnet_get_channels(struct net_device *dev, 1149 struct ethtool_channels *channels) 1150 { 1151 struct virtnet_info *vi = netdev_priv(dev); 1152 1153 channels->combined_count = vi->curr_queue_pairs; 1154 channels->max_combined = vi->max_queue_pairs; 1155 channels->max_other = 0; 1156 channels->rx_count = 0; 1157 channels->tx_count = 0; 1158 channels->other_count = 0; 1159 } 1160 1161 static const struct ethtool_ops virtnet_ethtool_ops = { 1162 .get_drvinfo = virtnet_get_drvinfo, 1163 .get_link = ethtool_op_get_link, 1164 .get_ringparam = virtnet_get_ringparam, 1165 .set_channels = virtnet_set_channels, 1166 .get_channels = virtnet_get_channels, 1167 }; 1168 1169 #define MIN_MTU 68 1170 #define MAX_MTU 65535 1171 1172 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 1173 { 1174 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 1175 return -EINVAL; 1176 dev->mtu = new_mtu; 1177 return 0; 1178 } 1179 1180 /* To avoid contending a lock hold by a vcpu who would exit to host, select the 1181 * txq based on the processor id. 1182 */ 1183 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb) 1184 { 1185 int txq; 1186 struct virtnet_info *vi = netdev_priv(dev); 1187 1188 if (skb_rx_queue_recorded(skb)) { 1189 txq = skb_get_rx_queue(skb); 1190 } else { 1191 txq = *__this_cpu_ptr(vi->vq_index); 1192 if (txq == -1) 1193 txq = 0; 1194 } 1195 1196 while (unlikely(txq >= dev->real_num_tx_queues)) 1197 txq -= dev->real_num_tx_queues; 1198 1199 return txq; 1200 } 1201 1202 static const struct net_device_ops virtnet_netdev = { 1203 .ndo_open = virtnet_open, 1204 .ndo_stop = virtnet_close, 1205 .ndo_start_xmit = start_xmit, 1206 .ndo_validate_addr = eth_validate_addr, 1207 .ndo_set_mac_address = virtnet_set_mac_address, 1208 .ndo_set_rx_mode = virtnet_set_rx_mode, 1209 .ndo_change_mtu = virtnet_change_mtu, 1210 .ndo_get_stats64 = virtnet_stats, 1211 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 1212 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 1213 .ndo_select_queue = virtnet_select_queue, 1214 #ifdef CONFIG_NET_POLL_CONTROLLER 1215 .ndo_poll_controller = virtnet_netpoll, 1216 #endif 1217 }; 1218 1219 static void virtnet_config_changed_work(struct work_struct *work) 1220 { 1221 struct virtnet_info *vi = 1222 container_of(work, struct virtnet_info, config_work); 1223 u16 v; 1224 1225 mutex_lock(&vi->config_lock); 1226 if (!vi->config_enable) 1227 goto done; 1228 1229 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS, 1230 offsetof(struct virtio_net_config, status), 1231 &v) < 0) 1232 goto done; 1233 1234 if (v & VIRTIO_NET_S_ANNOUNCE) { 1235 netdev_notify_peers(vi->dev); 1236 virtnet_ack_link_announce(vi); 1237 } 1238 1239 /* Ignore unknown (future) status bits */ 1240 v &= VIRTIO_NET_S_LINK_UP; 1241 1242 if (vi->status == v) 1243 goto done; 1244 1245 vi->status = v; 1246 1247 if (vi->status & VIRTIO_NET_S_LINK_UP) { 1248 netif_carrier_on(vi->dev); 1249 netif_tx_wake_all_queues(vi->dev); 1250 } else { 1251 netif_carrier_off(vi->dev); 1252 netif_tx_stop_all_queues(vi->dev); 1253 } 1254 done: 1255 mutex_unlock(&vi->config_lock); 1256 } 1257 1258 static void virtnet_config_changed(struct virtio_device *vdev) 1259 { 1260 struct virtnet_info *vi = vdev->priv; 1261 1262 schedule_work(&vi->config_work); 1263 } 1264 1265 static void virtnet_free_queues(struct virtnet_info *vi) 1266 { 1267 kfree(vi->rq); 1268 kfree(vi->sq); 1269 } 1270 1271 static void free_receive_bufs(struct virtnet_info *vi) 1272 { 1273 int i; 1274 1275 for (i = 0; i < vi->max_queue_pairs; i++) { 1276 while (vi->rq[i].pages) 1277 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0); 1278 } 1279 } 1280 1281 static void free_unused_bufs(struct virtnet_info *vi) 1282 { 1283 void *buf; 1284 int i; 1285 1286 for (i = 0; i < vi->max_queue_pairs; i++) { 1287 struct virtqueue *vq = vi->sq[i].vq; 1288 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) 1289 dev_kfree_skb(buf); 1290 } 1291 1292 for (i = 0; i < vi->max_queue_pairs; i++) { 1293 struct virtqueue *vq = vi->rq[i].vq; 1294 1295 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { 1296 if (vi->mergeable_rx_bufs || vi->big_packets) 1297 give_pages(&vi->rq[i], buf); 1298 else 1299 dev_kfree_skb(buf); 1300 --vi->rq[i].num; 1301 } 1302 BUG_ON(vi->rq[i].num != 0); 1303 } 1304 } 1305 1306 static void virtnet_del_vqs(struct virtnet_info *vi) 1307 { 1308 struct virtio_device *vdev = vi->vdev; 1309 1310 virtnet_clean_affinity(vi, -1); 1311 1312 vdev->config->del_vqs(vdev); 1313 1314 virtnet_free_queues(vi); 1315 } 1316 1317 static int virtnet_find_vqs(struct virtnet_info *vi) 1318 { 1319 vq_callback_t **callbacks; 1320 struct virtqueue **vqs; 1321 int ret = -ENOMEM; 1322 int i, total_vqs; 1323 const char **names; 1324 1325 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by 1326 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by 1327 * possible control vq. 1328 */ 1329 total_vqs = vi->max_queue_pairs * 2 + 1330 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); 1331 1332 /* Allocate space for find_vqs parameters */ 1333 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); 1334 if (!vqs) 1335 goto err_vq; 1336 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); 1337 if (!callbacks) 1338 goto err_callback; 1339 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); 1340 if (!names) 1341 goto err_names; 1342 1343 /* Parameters for control virtqueue, if any */ 1344 if (vi->has_cvq) { 1345 callbacks[total_vqs - 1] = NULL; 1346 names[total_vqs - 1] = "control"; 1347 } 1348 1349 /* Allocate/initialize parameters for send/receive virtqueues */ 1350 for (i = 0; i < vi->max_queue_pairs; i++) { 1351 callbacks[rxq2vq(i)] = skb_recv_done; 1352 callbacks[txq2vq(i)] = skb_xmit_done; 1353 sprintf(vi->rq[i].name, "input.%d", i); 1354 sprintf(vi->sq[i].name, "output.%d", i); 1355 names[rxq2vq(i)] = vi->rq[i].name; 1356 names[txq2vq(i)] = vi->sq[i].name; 1357 } 1358 1359 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, 1360 names); 1361 if (ret) 1362 goto err_find; 1363 1364 if (vi->has_cvq) { 1365 vi->cvq = vqs[total_vqs - 1]; 1366 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1367 vi->dev->features |= NETIF_F_HW_VLAN_FILTER; 1368 } 1369 1370 for (i = 0; i < vi->max_queue_pairs; i++) { 1371 vi->rq[i].vq = vqs[rxq2vq(i)]; 1372 vi->sq[i].vq = vqs[txq2vq(i)]; 1373 } 1374 1375 kfree(names); 1376 kfree(callbacks); 1377 kfree(vqs); 1378 1379 return 0; 1380 1381 err_find: 1382 kfree(names); 1383 err_names: 1384 kfree(callbacks); 1385 err_callback: 1386 kfree(vqs); 1387 err_vq: 1388 return ret; 1389 } 1390 1391 static int virtnet_alloc_queues(struct virtnet_info *vi) 1392 { 1393 int i; 1394 1395 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL); 1396 if (!vi->sq) 1397 goto err_sq; 1398 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL); 1399 if (!vi->rq) 1400 goto err_rq; 1401 1402 INIT_DELAYED_WORK(&vi->refill, refill_work); 1403 for (i = 0; i < vi->max_queue_pairs; i++) { 1404 vi->rq[i].pages = NULL; 1405 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll, 1406 napi_weight); 1407 1408 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); 1409 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); 1410 } 1411 1412 return 0; 1413 1414 err_rq: 1415 kfree(vi->sq); 1416 err_sq: 1417 return -ENOMEM; 1418 } 1419 1420 static int init_vqs(struct virtnet_info *vi) 1421 { 1422 int ret; 1423 1424 /* Allocate send & receive queues */ 1425 ret = virtnet_alloc_queues(vi); 1426 if (ret) 1427 goto err; 1428 1429 ret = virtnet_find_vqs(vi); 1430 if (ret) 1431 goto err_free; 1432 1433 get_online_cpus(); 1434 virtnet_set_affinity(vi); 1435 put_online_cpus(); 1436 1437 return 0; 1438 1439 err_free: 1440 virtnet_free_queues(vi); 1441 err: 1442 return ret; 1443 } 1444 1445 static int virtnet_probe(struct virtio_device *vdev) 1446 { 1447 int i, err; 1448 struct net_device *dev; 1449 struct virtnet_info *vi; 1450 u16 max_queue_pairs; 1451 1452 /* Find if host supports multiqueue virtio_net device */ 1453 err = virtio_config_val(vdev, VIRTIO_NET_F_MQ, 1454 offsetof(struct virtio_net_config, 1455 max_virtqueue_pairs), &max_queue_pairs); 1456 1457 /* We need at least 2 queue's */ 1458 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN || 1459 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX || 1460 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1461 max_queue_pairs = 1; 1462 1463 /* Allocate ourselves a network device with room for our info */ 1464 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); 1465 if (!dev) 1466 return -ENOMEM; 1467 1468 /* Set up network device as normal. */ 1469 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE; 1470 dev->netdev_ops = &virtnet_netdev; 1471 dev->features = NETIF_F_HIGHDMA; 1472 1473 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 1474 SET_NETDEV_DEV(dev, &vdev->dev); 1475 1476 /* Do we support "hardware" checksums? */ 1477 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 1478 /* This opens up the world of extra features. */ 1479 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1480 if (csum) 1481 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1482 1483 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 1484 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 1485 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 1486 } 1487 /* Individual feature bits: what can host handle? */ 1488 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 1489 dev->hw_features |= NETIF_F_TSO; 1490 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 1491 dev->hw_features |= NETIF_F_TSO6; 1492 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 1493 dev->hw_features |= NETIF_F_TSO_ECN; 1494 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1495 dev->hw_features |= NETIF_F_UFO; 1496 1497 if (gso) 1498 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1499 /* (!csum && gso) case will be fixed by register_netdev() */ 1500 } 1501 1502 /* Configuration may specify what MAC to use. Otherwise random. */ 1503 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC, 1504 offsetof(struct virtio_net_config, mac), 1505 dev->dev_addr, dev->addr_len) < 0) 1506 eth_hw_addr_random(dev); 1507 1508 /* Set up our device-specific information */ 1509 vi = netdev_priv(dev); 1510 vi->dev = dev; 1511 vi->vdev = vdev; 1512 vdev->priv = vi; 1513 vi->stats = alloc_percpu(struct virtnet_stats); 1514 err = -ENOMEM; 1515 if (vi->stats == NULL) 1516 goto free; 1517 1518 vi->vq_index = alloc_percpu(int); 1519 if (vi->vq_index == NULL) 1520 goto free_stats; 1521 1522 mutex_init(&vi->config_lock); 1523 vi->config_enable = true; 1524 INIT_WORK(&vi->config_work, virtnet_config_changed_work); 1525 1526 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1527 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1528 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1529 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1530 vi->big_packets = true; 1531 1532 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1533 vi->mergeable_rx_bufs = true; 1534 1535 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1536 vi->has_cvq = true; 1537 1538 /* Use single tx/rx queue pair as default */ 1539 vi->curr_queue_pairs = 1; 1540 vi->max_queue_pairs = max_queue_pairs; 1541 1542 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ 1543 err = init_vqs(vi); 1544 if (err) 1545 goto free_index; 1546 1547 netif_set_real_num_tx_queues(dev, 1); 1548 netif_set_real_num_rx_queues(dev, 1); 1549 1550 err = register_netdev(dev); 1551 if (err) { 1552 pr_debug("virtio_net: registering device failed\n"); 1553 goto free_vqs; 1554 } 1555 1556 /* Last of all, set up some receive buffers. */ 1557 for (i = 0; i < vi->max_queue_pairs; i++) { 1558 try_fill_recv(&vi->rq[i], GFP_KERNEL); 1559 1560 /* If we didn't even get one input buffer, we're useless. */ 1561 if (vi->rq[i].num == 0) { 1562 free_unused_bufs(vi); 1563 err = -ENOMEM; 1564 goto free_recv_bufs; 1565 } 1566 } 1567 1568 vi->nb.notifier_call = &virtnet_cpu_callback; 1569 err = register_hotcpu_notifier(&vi->nb); 1570 if (err) { 1571 pr_debug("virtio_net: registering cpu notifier failed\n"); 1572 goto free_recv_bufs; 1573 } 1574 1575 /* Assume link up if device can't report link status, 1576 otherwise get link status from config. */ 1577 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1578 netif_carrier_off(dev); 1579 schedule_work(&vi->config_work); 1580 } else { 1581 vi->status = VIRTIO_NET_S_LINK_UP; 1582 netif_carrier_on(dev); 1583 } 1584 1585 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", 1586 dev->name, max_queue_pairs); 1587 1588 return 0; 1589 1590 free_recv_bufs: 1591 free_receive_bufs(vi); 1592 unregister_netdev(dev); 1593 free_vqs: 1594 cancel_delayed_work_sync(&vi->refill); 1595 virtnet_del_vqs(vi); 1596 free_index: 1597 free_percpu(vi->vq_index); 1598 free_stats: 1599 free_percpu(vi->stats); 1600 free: 1601 free_netdev(dev); 1602 return err; 1603 } 1604 1605 static void remove_vq_common(struct virtnet_info *vi) 1606 { 1607 vi->vdev->config->reset(vi->vdev); 1608 1609 /* Free unused buffers in both send and recv, if any. */ 1610 free_unused_bufs(vi); 1611 1612 free_receive_bufs(vi); 1613 1614 virtnet_del_vqs(vi); 1615 } 1616 1617 static void virtnet_remove(struct virtio_device *vdev) 1618 { 1619 struct virtnet_info *vi = vdev->priv; 1620 1621 unregister_hotcpu_notifier(&vi->nb); 1622 1623 /* Prevent config work handler from accessing the device. */ 1624 mutex_lock(&vi->config_lock); 1625 vi->config_enable = false; 1626 mutex_unlock(&vi->config_lock); 1627 1628 unregister_netdev(vi->dev); 1629 1630 remove_vq_common(vi); 1631 1632 flush_work(&vi->config_work); 1633 1634 free_percpu(vi->vq_index); 1635 free_percpu(vi->stats); 1636 free_netdev(vi->dev); 1637 } 1638 1639 #ifdef CONFIG_PM 1640 static int virtnet_freeze(struct virtio_device *vdev) 1641 { 1642 struct virtnet_info *vi = vdev->priv; 1643 int i; 1644 1645 /* Prevent config work handler from accessing the device */ 1646 mutex_lock(&vi->config_lock); 1647 vi->config_enable = false; 1648 mutex_unlock(&vi->config_lock); 1649 1650 netif_device_detach(vi->dev); 1651 cancel_delayed_work_sync(&vi->refill); 1652 1653 if (netif_running(vi->dev)) 1654 for (i = 0; i < vi->max_queue_pairs; i++) { 1655 napi_disable(&vi->rq[i].napi); 1656 netif_napi_del(&vi->rq[i].napi); 1657 } 1658 1659 remove_vq_common(vi); 1660 1661 flush_work(&vi->config_work); 1662 1663 return 0; 1664 } 1665 1666 static int virtnet_restore(struct virtio_device *vdev) 1667 { 1668 struct virtnet_info *vi = vdev->priv; 1669 int err, i; 1670 1671 err = init_vqs(vi); 1672 if (err) 1673 return err; 1674 1675 if (netif_running(vi->dev)) 1676 for (i = 0; i < vi->max_queue_pairs; i++) 1677 virtnet_napi_enable(&vi->rq[i]); 1678 1679 netif_device_attach(vi->dev); 1680 1681 for (i = 0; i < vi->max_queue_pairs; i++) 1682 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 1683 schedule_delayed_work(&vi->refill, 0); 1684 1685 mutex_lock(&vi->config_lock); 1686 vi->config_enable = true; 1687 mutex_unlock(&vi->config_lock); 1688 1689 virtnet_set_queues(vi, vi->curr_queue_pairs); 1690 1691 return 0; 1692 } 1693 #endif 1694 1695 static struct virtio_device_id id_table[] = { 1696 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1697 { 0 }, 1698 }; 1699 1700 static unsigned int features[] = { 1701 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1702 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1703 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1704 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1705 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1706 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1707 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1708 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, 1709 }; 1710 1711 static struct virtio_driver virtio_net_driver = { 1712 .feature_table = features, 1713 .feature_table_size = ARRAY_SIZE(features), 1714 .driver.name = KBUILD_MODNAME, 1715 .driver.owner = THIS_MODULE, 1716 .id_table = id_table, 1717 .probe = virtnet_probe, 1718 .remove = virtnet_remove, 1719 .config_changed = virtnet_config_changed, 1720 #ifdef CONFIG_PM 1721 .freeze = virtnet_freeze, 1722 .restore = virtnet_restore, 1723 #endif 1724 }; 1725 1726 static int __init init(void) 1727 { 1728 return register_virtio_driver(&virtio_net_driver); 1729 } 1730 1731 static void __exit fini(void) 1732 { 1733 unregister_virtio_driver(&virtio_net_driver); 1734 } 1735 module_init(init); 1736 module_exit(fini); 1737 1738 MODULE_DEVICE_TABLE(virtio, id_table); 1739 MODULE_DESCRIPTION("Virtio network driver"); 1740 MODULE_LICENSE("GPL"); 1741