1 /* A network driver using virtio. 2 * 3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 //#define DEBUG 20 #include <linux/netdevice.h> 21 #include <linux/etherdevice.h> 22 #include <linux/ethtool.h> 23 #include <linux/module.h> 24 #include <linux/virtio.h> 25 #include <linux/virtio_net.h> 26 #include <linux/scatterlist.h> 27 #include <linux/if_vlan.h> 28 #include <linux/slab.h> 29 30 static int napi_weight = 128; 31 module_param(napi_weight, int, 0444); 32 33 static bool csum = true, gso = true; 34 module_param(csum, bool, 0444); 35 module_param(gso, bool, 0444); 36 37 /* FIXME: MTU in config. */ 38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 39 #define GOOD_COPY_LEN 128 40 41 #define VIRTNET_SEND_COMMAND_SG_MAX 2 42 #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 }; 127 128 struct skb_vnet_hdr { 129 union { 130 struct virtio_net_hdr hdr; 131 struct virtio_net_hdr_mrg_rxbuf mhdr; 132 }; 133 }; 134 135 struct padded_vnet_hdr { 136 struct virtio_net_hdr hdr; 137 /* 138 * virtio_net_hdr should be in a separated sg buffer because of a 139 * QEMU bug, and data sg buffer shares same page with this header sg. 140 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 141 */ 142 char padding[6]; 143 }; 144 145 /* Converting between virtqueue no. and kernel tx/rx queue no. 146 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq 147 */ 148 static int vq2txq(struct virtqueue *vq) 149 { 150 return (virtqueue_get_queue_index(vq) - 1) / 2; 151 } 152 153 static int txq2vq(int txq) 154 { 155 return txq * 2 + 1; 156 } 157 158 static int vq2rxq(struct virtqueue *vq) 159 { 160 return virtqueue_get_queue_index(vq) / 2; 161 } 162 163 static int rxq2vq(int rxq) 164 { 165 return rxq * 2; 166 } 167 168 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 169 { 170 return (struct skb_vnet_hdr *)skb->cb; 171 } 172 173 /* 174 * private is used to chain pages for big packets, put the whole 175 * most recent used list in the beginning for reuse 176 */ 177 static void give_pages(struct receive_queue *rq, struct page *page) 178 { 179 struct page *end; 180 181 /* Find end of list, sew whole thing into vi->rq.pages. */ 182 for (end = page; end->private; end = (struct page *)end->private); 183 end->private = (unsigned long)rq->pages; 184 rq->pages = page; 185 } 186 187 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) 188 { 189 struct page *p = rq->pages; 190 191 if (p) { 192 rq->pages = (struct page *)p->private; 193 /* clear private here, it is used to chain pages */ 194 p->private = 0; 195 } else 196 p = alloc_page(gfp_mask); 197 return p; 198 } 199 200 static void skb_xmit_done(struct virtqueue *vq) 201 { 202 struct virtnet_info *vi = vq->vdev->priv; 203 204 /* Suppress further interrupts. */ 205 virtqueue_disable_cb(vq); 206 207 /* We were probably waiting for more output buffers. */ 208 netif_wake_subqueue(vi->dev, vq2txq(vq)); 209 } 210 211 static void set_skb_frag(struct sk_buff *skb, struct page *page, 212 unsigned int offset, unsigned int *len) 213 { 214 int size = min((unsigned)PAGE_SIZE - offset, *len); 215 int i = skb_shinfo(skb)->nr_frags; 216 217 __skb_fill_page_desc(skb, i, page, offset, size); 218 219 skb->data_len += size; 220 skb->len += size; 221 skb->truesize += PAGE_SIZE; 222 skb_shinfo(skb)->nr_frags++; 223 *len -= size; 224 } 225 226 /* Called from bottom half context */ 227 static struct sk_buff *page_to_skb(struct receive_queue *rq, 228 struct page *page, unsigned int len) 229 { 230 struct virtnet_info *vi = rq->vq->vdev->priv; 231 struct sk_buff *skb; 232 struct skb_vnet_hdr *hdr; 233 unsigned int copy, hdr_len, offset; 234 char *p; 235 236 p = page_address(page); 237 238 /* copy small packet so we can reuse these pages for small data */ 239 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 240 if (unlikely(!skb)) 241 return NULL; 242 243 hdr = skb_vnet_hdr(skb); 244 245 if (vi->mergeable_rx_bufs) { 246 hdr_len = sizeof hdr->mhdr; 247 offset = hdr_len; 248 } else { 249 hdr_len = sizeof hdr->hdr; 250 offset = sizeof(struct padded_vnet_hdr); 251 } 252 253 memcpy(hdr, p, hdr_len); 254 255 len -= hdr_len; 256 p += offset; 257 258 copy = len; 259 if (copy > skb_tailroom(skb)) 260 copy = skb_tailroom(skb); 261 memcpy(skb_put(skb, copy), p, copy); 262 263 len -= copy; 264 offset += copy; 265 266 /* 267 * Verify that we can indeed put this data into a skb. 268 * This is here to handle cases when the device erroneously 269 * tries to receive more than is possible. This is usually 270 * the case of a broken device. 271 */ 272 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 273 net_dbg_ratelimited("%s: too much data\n", skb->dev->name); 274 dev_kfree_skb(skb); 275 return NULL; 276 } 277 278 while (len) { 279 set_skb_frag(skb, page, offset, &len); 280 page = (struct page *)page->private; 281 offset = 0; 282 } 283 284 if (page) 285 give_pages(rq, page); 286 287 return skb; 288 } 289 290 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb) 291 { 292 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 293 struct page *page; 294 int num_buf, i, len; 295 296 num_buf = hdr->mhdr.num_buffers; 297 while (--num_buf) { 298 i = skb_shinfo(skb)->nr_frags; 299 if (i >= MAX_SKB_FRAGS) { 300 pr_debug("%s: packet too long\n", skb->dev->name); 301 skb->dev->stats.rx_length_errors++; 302 return -EINVAL; 303 } 304 page = virtqueue_get_buf(rq->vq, &len); 305 if (!page) { 306 pr_debug("%s: rx error: %d buffers missing\n", 307 skb->dev->name, hdr->mhdr.num_buffers); 308 skb->dev->stats.rx_length_errors++; 309 return -EINVAL; 310 } 311 312 if (len > PAGE_SIZE) 313 len = PAGE_SIZE; 314 315 set_skb_frag(skb, page, 0, &len); 316 317 --rq->num; 318 } 319 return 0; 320 } 321 322 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) 323 { 324 struct virtnet_info *vi = rq->vq->vdev->priv; 325 struct net_device *dev = vi->dev; 326 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 327 struct sk_buff *skb; 328 struct page *page; 329 struct skb_vnet_hdr *hdr; 330 331 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 332 pr_debug("%s: short packet %i\n", dev->name, len); 333 dev->stats.rx_length_errors++; 334 if (vi->mergeable_rx_bufs || vi->big_packets) 335 give_pages(rq, buf); 336 else 337 dev_kfree_skb(buf); 338 return; 339 } 340 341 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 342 skb = buf; 343 len -= sizeof(struct virtio_net_hdr); 344 skb_trim(skb, len); 345 } else { 346 page = buf; 347 skb = page_to_skb(rq, page, len); 348 if (unlikely(!skb)) { 349 dev->stats.rx_dropped++; 350 give_pages(rq, page); 351 return; 352 } 353 if (vi->mergeable_rx_bufs) 354 if (receive_mergeable(rq, skb)) { 355 dev_kfree_skb(skb); 356 return; 357 } 358 } 359 360 hdr = skb_vnet_hdr(skb); 361 362 u64_stats_update_begin(&stats->rx_syncp); 363 stats->rx_bytes += skb->len; 364 stats->rx_packets++; 365 u64_stats_update_end(&stats->rx_syncp); 366 367 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 368 pr_debug("Needs csum!\n"); 369 if (!skb_partial_csum_set(skb, 370 hdr->hdr.csum_start, 371 hdr->hdr.csum_offset)) 372 goto frame_err; 373 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 374 skb->ip_summed = CHECKSUM_UNNECESSARY; 375 } 376 377 skb->protocol = eth_type_trans(skb, dev); 378 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 379 ntohs(skb->protocol), skb->len, skb->pkt_type); 380 381 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 382 pr_debug("GSO!\n"); 383 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 384 case VIRTIO_NET_HDR_GSO_TCPV4: 385 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 386 break; 387 case VIRTIO_NET_HDR_GSO_UDP: 388 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 389 break; 390 case VIRTIO_NET_HDR_GSO_TCPV6: 391 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 392 break; 393 default: 394 net_warn_ratelimited("%s: bad gso type %u.\n", 395 dev->name, hdr->hdr.gso_type); 396 goto frame_err; 397 } 398 399 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 400 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 401 402 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 403 if (skb_shinfo(skb)->gso_size == 0) { 404 net_warn_ratelimited("%s: zero gso size.\n", dev->name); 405 goto frame_err; 406 } 407 408 /* Header must be checked, and gso_segs computed. */ 409 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 410 skb_shinfo(skb)->gso_segs = 0; 411 } 412 413 netif_receive_skb(skb); 414 return; 415 416 frame_err: 417 dev->stats.rx_frame_errors++; 418 dev_kfree_skb(skb); 419 } 420 421 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) 422 { 423 struct virtnet_info *vi = rq->vq->vdev->priv; 424 struct sk_buff *skb; 425 struct skb_vnet_hdr *hdr; 426 int err; 427 428 skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); 429 if (unlikely(!skb)) 430 return -ENOMEM; 431 432 skb_put(skb, MAX_PACKET_LEN); 433 434 hdr = skb_vnet_hdr(skb); 435 sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); 436 437 skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); 438 439 err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp); 440 if (err < 0) 441 dev_kfree_skb(skb); 442 443 return err; 444 } 445 446 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp) 447 { 448 struct page *first, *list = NULL; 449 char *p; 450 int i, err, offset; 451 452 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ 453 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 454 first = get_a_page(rq, gfp); 455 if (!first) { 456 if (list) 457 give_pages(rq, list); 458 return -ENOMEM; 459 } 460 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE); 461 462 /* chain new page in list head to match sg */ 463 first->private = (unsigned long)list; 464 list = first; 465 } 466 467 first = get_a_page(rq, gfp); 468 if (!first) { 469 give_pages(rq, list); 470 return -ENOMEM; 471 } 472 p = page_address(first); 473 474 /* rq->sg[0], rq->sg[1] share the same page */ 475 /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */ 476 sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr)); 477 478 /* rq->sg[1] for data packet, from offset */ 479 offset = sizeof(struct padded_vnet_hdr); 480 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); 481 482 /* chain first in list head */ 483 first->private = (unsigned long)list; 484 err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2, 485 first, gfp); 486 if (err < 0) 487 give_pages(rq, first); 488 489 return err; 490 } 491 492 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) 493 { 494 struct page *page; 495 int err; 496 497 page = get_a_page(rq, gfp); 498 if (!page) 499 return -ENOMEM; 500 501 sg_init_one(rq->sg, page_address(page), PAGE_SIZE); 502 503 err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp); 504 if (err < 0) 505 give_pages(rq, page); 506 507 return err; 508 } 509 510 /* 511 * Returns false if we couldn't fill entirely (OOM). 512 * 513 * Normally run in the receive path, but can also be run from ndo_open 514 * before we're receiving packets, or from refill_work which is 515 * careful to disable receiving (using napi_disable). 516 */ 517 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) 518 { 519 struct virtnet_info *vi = rq->vq->vdev->priv; 520 int err; 521 bool oom; 522 523 do { 524 if (vi->mergeable_rx_bufs) 525 err = add_recvbuf_mergeable(rq, gfp); 526 else if (vi->big_packets) 527 err = add_recvbuf_big(rq, gfp); 528 else 529 err = add_recvbuf_small(rq, gfp); 530 531 oom = err == -ENOMEM; 532 if (err) 533 break; 534 ++rq->num; 535 } while (rq->vq->num_free); 536 if (unlikely(rq->num > rq->max)) 537 rq->max = rq->num; 538 virtqueue_kick(rq->vq); 539 return !oom; 540 } 541 542 static void skb_recv_done(struct virtqueue *rvq) 543 { 544 struct virtnet_info *vi = rvq->vdev->priv; 545 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)]; 546 547 /* Schedule NAPI, Suppress further interrupts if successful. */ 548 if (napi_schedule_prep(&rq->napi)) { 549 virtqueue_disable_cb(rvq); 550 __napi_schedule(&rq->napi); 551 } 552 } 553 554 static void virtnet_napi_enable(struct receive_queue *rq) 555 { 556 napi_enable(&rq->napi); 557 558 /* If all buffers were filled by other side before we napi_enabled, we 559 * won't get another interrupt, so process any outstanding packets 560 * now. virtnet_poll wants re-enable the queue, so we disable here. 561 * We synchronize against interrupts via NAPI_STATE_SCHED */ 562 if (napi_schedule_prep(&rq->napi)) { 563 virtqueue_disable_cb(rq->vq); 564 local_bh_disable(); 565 __napi_schedule(&rq->napi); 566 local_bh_enable(); 567 } 568 } 569 570 static void refill_work(struct work_struct *work) 571 { 572 struct virtnet_info *vi = 573 container_of(work, struct virtnet_info, refill.work); 574 bool still_empty; 575 int i; 576 577 for (i = 0; i < vi->max_queue_pairs; i++) { 578 struct receive_queue *rq = &vi->rq[i]; 579 580 napi_disable(&rq->napi); 581 still_empty = !try_fill_recv(rq, GFP_KERNEL); 582 virtnet_napi_enable(rq); 583 584 /* In theory, this can happen: if we don't get any buffers in 585 * we will *never* try to fill again. 586 */ 587 if (still_empty) 588 schedule_delayed_work(&vi->refill, HZ/2); 589 } 590 } 591 592 static int virtnet_poll(struct napi_struct *napi, int budget) 593 { 594 struct receive_queue *rq = 595 container_of(napi, struct receive_queue, napi); 596 struct virtnet_info *vi = rq->vq->vdev->priv; 597 void *buf; 598 unsigned int len, received = 0; 599 600 again: 601 while (received < budget && 602 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { 603 receive_buf(rq, buf, len); 604 --rq->num; 605 received++; 606 } 607 608 if (rq->num < rq->max / 2) { 609 if (!try_fill_recv(rq, GFP_ATOMIC)) 610 schedule_delayed_work(&vi->refill, 0); 611 } 612 613 /* Out of packets? */ 614 if (received < budget) { 615 napi_complete(napi); 616 if (unlikely(!virtqueue_enable_cb(rq->vq)) && 617 napi_schedule_prep(napi)) { 618 virtqueue_disable_cb(rq->vq); 619 __napi_schedule(napi); 620 goto again; 621 } 622 } 623 624 return received; 625 } 626 627 static int virtnet_open(struct net_device *dev) 628 { 629 struct virtnet_info *vi = netdev_priv(dev); 630 int i; 631 632 for (i = 0; i < vi->max_queue_pairs; i++) { 633 /* Make sure we have some buffers: if oom use wq. */ 634 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 635 schedule_delayed_work(&vi->refill, 0); 636 virtnet_napi_enable(&vi->rq[i]); 637 } 638 639 return 0; 640 } 641 642 static void free_old_xmit_skbs(struct send_queue *sq) 643 { 644 struct sk_buff *skb; 645 unsigned int len; 646 struct virtnet_info *vi = sq->vq->vdev->priv; 647 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 648 649 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { 650 pr_debug("Sent skb %p\n", skb); 651 652 u64_stats_update_begin(&stats->tx_syncp); 653 stats->tx_bytes += skb->len; 654 stats->tx_packets++; 655 u64_stats_update_end(&stats->tx_syncp); 656 657 dev_kfree_skb_any(skb); 658 } 659 } 660 661 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) 662 { 663 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 664 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 665 struct virtnet_info *vi = sq->vq->vdev->priv; 666 unsigned num_sg; 667 668 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 669 670 if (skb->ip_summed == CHECKSUM_PARTIAL) { 671 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 672 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 673 hdr->hdr.csum_offset = skb->csum_offset; 674 } else { 675 hdr->hdr.flags = 0; 676 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 677 } 678 679 if (skb_is_gso(skb)) { 680 hdr->hdr.hdr_len = skb_headlen(skb); 681 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 682 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 683 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 684 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 685 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 686 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 687 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 688 else 689 BUG(); 690 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 691 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 692 } else { 693 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 694 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 695 } 696 697 hdr->mhdr.num_buffers = 0; 698 699 /* Encode metadata header at front. */ 700 if (vi->mergeable_rx_bufs) 701 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr); 702 else 703 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr); 704 705 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1; 706 return virtqueue_add_buf(sq->vq, sq->sg, num_sg, 707 0, skb, GFP_ATOMIC); 708 } 709 710 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 711 { 712 struct virtnet_info *vi = netdev_priv(dev); 713 int qnum = skb_get_queue_mapping(skb); 714 struct send_queue *sq = &vi->sq[qnum]; 715 int err; 716 717 /* Free up any pending old buffers before queueing new ones. */ 718 free_old_xmit_skbs(sq); 719 720 /* Try to transmit */ 721 err = xmit_skb(sq, skb); 722 723 /* This should not happen! */ 724 if (unlikely(err)) { 725 dev->stats.tx_fifo_errors++; 726 if (net_ratelimit()) 727 dev_warn(&dev->dev, 728 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); 729 dev->stats.tx_dropped++; 730 kfree_skb(skb); 731 return NETDEV_TX_OK; 732 } 733 virtqueue_kick(sq->vq); 734 735 /* Don't wait up for transmitted skbs to be freed. */ 736 skb_orphan(skb); 737 nf_reset(skb); 738 739 /* Apparently nice girls don't return TX_BUSY; stop the queue 740 * before it gets out of hand. Naturally, this wastes entries. */ 741 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { 742 netif_stop_subqueue(dev, qnum); 743 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { 744 /* More just got used, free them then recheck. */ 745 free_old_xmit_skbs(sq); 746 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { 747 netif_start_subqueue(dev, qnum); 748 virtqueue_disable_cb(sq->vq); 749 } 750 } 751 } 752 753 return NETDEV_TX_OK; 754 } 755 756 static int virtnet_set_mac_address(struct net_device *dev, void *p) 757 { 758 struct virtnet_info *vi = netdev_priv(dev); 759 struct virtio_device *vdev = vi->vdev; 760 int ret; 761 762 ret = eth_mac_addr(dev, p); 763 if (ret) 764 return ret; 765 766 if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) 767 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 768 dev->dev_addr, dev->addr_len); 769 770 return 0; 771 } 772 773 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 774 struct rtnl_link_stats64 *tot) 775 { 776 struct virtnet_info *vi = netdev_priv(dev); 777 int cpu; 778 unsigned int start; 779 780 for_each_possible_cpu(cpu) { 781 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); 782 u64 tpackets, tbytes, rpackets, rbytes; 783 784 do { 785 start = u64_stats_fetch_begin_bh(&stats->tx_syncp); 786 tpackets = stats->tx_packets; 787 tbytes = stats->tx_bytes; 788 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start)); 789 790 do { 791 start = u64_stats_fetch_begin_bh(&stats->rx_syncp); 792 rpackets = stats->rx_packets; 793 rbytes = stats->rx_bytes; 794 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start)); 795 796 tot->rx_packets += rpackets; 797 tot->tx_packets += tpackets; 798 tot->rx_bytes += rbytes; 799 tot->tx_bytes += tbytes; 800 } 801 802 tot->tx_dropped = dev->stats.tx_dropped; 803 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 804 tot->rx_dropped = dev->stats.rx_dropped; 805 tot->rx_length_errors = dev->stats.rx_length_errors; 806 tot->rx_frame_errors = dev->stats.rx_frame_errors; 807 808 return tot; 809 } 810 811 #ifdef CONFIG_NET_POLL_CONTROLLER 812 static void virtnet_netpoll(struct net_device *dev) 813 { 814 struct virtnet_info *vi = netdev_priv(dev); 815 int i; 816 817 for (i = 0; i < vi->curr_queue_pairs; i++) 818 napi_schedule(&vi->rq[i].napi); 819 } 820 #endif 821 822 /* 823 * Send command via the control virtqueue and check status. Commands 824 * supported by the hypervisor, as indicated by feature bits, should 825 * never fail unless improperly formated. 826 */ 827 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 828 struct scatterlist *data, int out, int in) 829 { 830 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 831 struct virtio_net_ctrl_hdr ctrl; 832 virtio_net_ctrl_ack status = ~0; 833 unsigned int tmp; 834 int i; 835 836 /* Caller should know better */ 837 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 838 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 839 840 out++; /* Add header */ 841 in++; /* Add return status */ 842 843 ctrl.class = class; 844 ctrl.cmd = cmd; 845 846 sg_init_table(sg, out + in); 847 848 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 849 for_each_sg(data, s, out + in - 2, i) 850 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 851 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 852 853 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0); 854 855 virtqueue_kick(vi->cvq); 856 857 /* 858 * Spin for a response, the kick causes an ioport write, trapping 859 * into the hypervisor, so the request should be handled immediately. 860 */ 861 while (!virtqueue_get_buf(vi->cvq, &tmp)) 862 cpu_relax(); 863 864 return status == VIRTIO_NET_OK; 865 } 866 867 static void virtnet_ack_link_announce(struct virtnet_info *vi) 868 { 869 rtnl_lock(); 870 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE, 871 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, 872 0, 0)) 873 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n"); 874 rtnl_unlock(); 875 } 876 877 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) 878 { 879 struct scatterlist sg; 880 struct virtio_net_ctrl_mq s; 881 struct net_device *dev = vi->dev; 882 883 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) 884 return 0; 885 886 s.virtqueue_pairs = queue_pairs; 887 sg_init_one(&sg, &s, sizeof(s)); 888 889 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ, 890 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){ 891 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", 892 queue_pairs); 893 return -EINVAL; 894 } else 895 vi->curr_queue_pairs = queue_pairs; 896 897 return 0; 898 } 899 900 static int virtnet_close(struct net_device *dev) 901 { 902 struct virtnet_info *vi = netdev_priv(dev); 903 int i; 904 905 /* Make sure refill_work doesn't re-enable napi! */ 906 cancel_delayed_work_sync(&vi->refill); 907 908 for (i = 0; i < vi->max_queue_pairs; i++) 909 napi_disable(&vi->rq[i].napi); 910 911 return 0; 912 } 913 914 static void virtnet_set_rx_mode(struct net_device *dev) 915 { 916 struct virtnet_info *vi = netdev_priv(dev); 917 struct scatterlist sg[2]; 918 u8 promisc, allmulti; 919 struct virtio_net_ctrl_mac *mac_data; 920 struct netdev_hw_addr *ha; 921 int uc_count; 922 int mc_count; 923 void *buf; 924 int i; 925 926 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 927 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 928 return; 929 930 promisc = ((dev->flags & IFF_PROMISC) != 0); 931 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 932 933 sg_init_one(sg, &promisc, sizeof(promisc)); 934 935 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 936 VIRTIO_NET_CTRL_RX_PROMISC, 937 sg, 1, 0)) 938 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 939 promisc ? "en" : "dis"); 940 941 sg_init_one(sg, &allmulti, sizeof(allmulti)); 942 943 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 944 VIRTIO_NET_CTRL_RX_ALLMULTI, 945 sg, 1, 0)) 946 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 947 allmulti ? "en" : "dis"); 948 949 uc_count = netdev_uc_count(dev); 950 mc_count = netdev_mc_count(dev); 951 /* MAC filter - use one buffer for both lists */ 952 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 953 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 954 mac_data = buf; 955 if (!buf) { 956 dev_warn(&dev->dev, "No memory for MAC address buffer\n"); 957 return; 958 } 959 960 sg_init_table(sg, 2); 961 962 /* Store the unicast list and count in the front of the buffer */ 963 mac_data->entries = uc_count; 964 i = 0; 965 netdev_for_each_uc_addr(ha, dev) 966 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 967 968 sg_set_buf(&sg[0], mac_data, 969 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 970 971 /* multicast list and count fill the end */ 972 mac_data = (void *)&mac_data->macs[uc_count][0]; 973 974 mac_data->entries = mc_count; 975 i = 0; 976 netdev_for_each_mc_addr(ha, dev) 977 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 978 979 sg_set_buf(&sg[1], mac_data, 980 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 981 982 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 983 VIRTIO_NET_CTRL_MAC_TABLE_SET, 984 sg, 2, 0)) 985 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 986 987 kfree(buf); 988 } 989 990 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 991 { 992 struct virtnet_info *vi = netdev_priv(dev); 993 struct scatterlist sg; 994 995 sg_init_one(&sg, &vid, sizeof(vid)); 996 997 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 998 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 999 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 1000 return 0; 1001 } 1002 1003 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 1004 { 1005 struct virtnet_info *vi = netdev_priv(dev); 1006 struct scatterlist sg; 1007 1008 sg_init_one(&sg, &vid, sizeof(vid)); 1009 1010 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1011 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 1012 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 1013 return 0; 1014 } 1015 1016 static void virtnet_set_affinity(struct virtnet_info *vi, bool set) 1017 { 1018 int i; 1019 1020 /* In multiqueue mode, when the number of cpu is equal to the number of 1021 * queue pairs, we let the queue pairs to be private to one cpu by 1022 * setting the affinity hint to eliminate the contention. 1023 */ 1024 if ((vi->curr_queue_pairs == 1 || 1025 vi->max_queue_pairs != num_online_cpus()) && set) { 1026 if (vi->affinity_hint_set) 1027 set = false; 1028 else 1029 return; 1030 } 1031 1032 for (i = 0; i < vi->max_queue_pairs; i++) { 1033 int cpu = set ? i : -1; 1034 virtqueue_set_affinity(vi->rq[i].vq, cpu); 1035 virtqueue_set_affinity(vi->sq[i].vq, cpu); 1036 } 1037 1038 if (set) 1039 vi->affinity_hint_set = true; 1040 else 1041 vi->affinity_hint_set = false; 1042 } 1043 1044 static void virtnet_get_ringparam(struct net_device *dev, 1045 struct ethtool_ringparam *ring) 1046 { 1047 struct virtnet_info *vi = netdev_priv(dev); 1048 1049 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq); 1050 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq); 1051 ring->rx_pending = ring->rx_max_pending; 1052 ring->tx_pending = ring->tx_max_pending; 1053 } 1054 1055 1056 static void virtnet_get_drvinfo(struct net_device *dev, 1057 struct ethtool_drvinfo *info) 1058 { 1059 struct virtnet_info *vi = netdev_priv(dev); 1060 struct virtio_device *vdev = vi->vdev; 1061 1062 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 1063 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 1064 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 1065 1066 } 1067 1068 /* TODO: Eliminate OOO packets during switching */ 1069 static int virtnet_set_channels(struct net_device *dev, 1070 struct ethtool_channels *channels) 1071 { 1072 struct virtnet_info *vi = netdev_priv(dev); 1073 u16 queue_pairs = channels->combined_count; 1074 int err; 1075 1076 /* We don't support separate rx/tx channels. 1077 * We don't allow setting 'other' channels. 1078 */ 1079 if (channels->rx_count || channels->tx_count || channels->other_count) 1080 return -EINVAL; 1081 1082 if (queue_pairs > vi->max_queue_pairs) 1083 return -EINVAL; 1084 1085 err = virtnet_set_queues(vi, queue_pairs); 1086 if (!err) { 1087 netif_set_real_num_tx_queues(dev, queue_pairs); 1088 netif_set_real_num_rx_queues(dev, queue_pairs); 1089 1090 virtnet_set_affinity(vi, true); 1091 } 1092 1093 return err; 1094 } 1095 1096 static void virtnet_get_channels(struct net_device *dev, 1097 struct ethtool_channels *channels) 1098 { 1099 struct virtnet_info *vi = netdev_priv(dev); 1100 1101 channels->combined_count = vi->curr_queue_pairs; 1102 channels->max_combined = vi->max_queue_pairs; 1103 channels->max_other = 0; 1104 channels->rx_count = 0; 1105 channels->tx_count = 0; 1106 channels->other_count = 0; 1107 } 1108 1109 static const struct ethtool_ops virtnet_ethtool_ops = { 1110 .get_drvinfo = virtnet_get_drvinfo, 1111 .get_link = ethtool_op_get_link, 1112 .get_ringparam = virtnet_get_ringparam, 1113 .set_channels = virtnet_set_channels, 1114 .get_channels = virtnet_get_channels, 1115 }; 1116 1117 #define MIN_MTU 68 1118 #define MAX_MTU 65535 1119 1120 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 1121 { 1122 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 1123 return -EINVAL; 1124 dev->mtu = new_mtu; 1125 return 0; 1126 } 1127 1128 /* To avoid contending a lock hold by a vcpu who would exit to host, select the 1129 * txq based on the processor id. 1130 * TODO: handle cpu hotplug. 1131 */ 1132 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb) 1133 { 1134 int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 1135 smp_processor_id(); 1136 1137 while (unlikely(txq >= dev->real_num_tx_queues)) 1138 txq -= dev->real_num_tx_queues; 1139 1140 return txq; 1141 } 1142 1143 static const struct net_device_ops virtnet_netdev = { 1144 .ndo_open = virtnet_open, 1145 .ndo_stop = virtnet_close, 1146 .ndo_start_xmit = start_xmit, 1147 .ndo_validate_addr = eth_validate_addr, 1148 .ndo_set_mac_address = virtnet_set_mac_address, 1149 .ndo_set_rx_mode = virtnet_set_rx_mode, 1150 .ndo_change_mtu = virtnet_change_mtu, 1151 .ndo_get_stats64 = virtnet_stats, 1152 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 1153 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 1154 .ndo_select_queue = virtnet_select_queue, 1155 #ifdef CONFIG_NET_POLL_CONTROLLER 1156 .ndo_poll_controller = virtnet_netpoll, 1157 #endif 1158 }; 1159 1160 static void virtnet_config_changed_work(struct work_struct *work) 1161 { 1162 struct virtnet_info *vi = 1163 container_of(work, struct virtnet_info, config_work); 1164 u16 v; 1165 1166 mutex_lock(&vi->config_lock); 1167 if (!vi->config_enable) 1168 goto done; 1169 1170 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS, 1171 offsetof(struct virtio_net_config, status), 1172 &v) < 0) 1173 goto done; 1174 1175 if (v & VIRTIO_NET_S_ANNOUNCE) { 1176 netdev_notify_peers(vi->dev); 1177 virtnet_ack_link_announce(vi); 1178 } 1179 1180 /* Ignore unknown (future) status bits */ 1181 v &= VIRTIO_NET_S_LINK_UP; 1182 1183 if (vi->status == v) 1184 goto done; 1185 1186 vi->status = v; 1187 1188 if (vi->status & VIRTIO_NET_S_LINK_UP) { 1189 netif_carrier_on(vi->dev); 1190 netif_tx_wake_all_queues(vi->dev); 1191 } else { 1192 netif_carrier_off(vi->dev); 1193 netif_tx_stop_all_queues(vi->dev); 1194 } 1195 done: 1196 mutex_unlock(&vi->config_lock); 1197 } 1198 1199 static void virtnet_config_changed(struct virtio_device *vdev) 1200 { 1201 struct virtnet_info *vi = vdev->priv; 1202 1203 schedule_work(&vi->config_work); 1204 } 1205 1206 static void virtnet_free_queues(struct virtnet_info *vi) 1207 { 1208 kfree(vi->rq); 1209 kfree(vi->sq); 1210 } 1211 1212 static void free_receive_bufs(struct virtnet_info *vi) 1213 { 1214 int i; 1215 1216 for (i = 0; i < vi->max_queue_pairs; i++) { 1217 while (vi->rq[i].pages) 1218 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0); 1219 } 1220 } 1221 1222 static void free_unused_bufs(struct virtnet_info *vi) 1223 { 1224 void *buf; 1225 int i; 1226 1227 for (i = 0; i < vi->max_queue_pairs; i++) { 1228 struct virtqueue *vq = vi->sq[i].vq; 1229 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) 1230 dev_kfree_skb(buf); 1231 } 1232 1233 for (i = 0; i < vi->max_queue_pairs; i++) { 1234 struct virtqueue *vq = vi->rq[i].vq; 1235 1236 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { 1237 if (vi->mergeable_rx_bufs || vi->big_packets) 1238 give_pages(&vi->rq[i], buf); 1239 else 1240 dev_kfree_skb(buf); 1241 --vi->rq[i].num; 1242 } 1243 BUG_ON(vi->rq[i].num != 0); 1244 } 1245 } 1246 1247 static void virtnet_del_vqs(struct virtnet_info *vi) 1248 { 1249 struct virtio_device *vdev = vi->vdev; 1250 1251 virtnet_set_affinity(vi, false); 1252 1253 vdev->config->del_vqs(vdev); 1254 1255 virtnet_free_queues(vi); 1256 } 1257 1258 static int virtnet_find_vqs(struct virtnet_info *vi) 1259 { 1260 vq_callback_t **callbacks; 1261 struct virtqueue **vqs; 1262 int ret = -ENOMEM; 1263 int i, total_vqs; 1264 const char **names; 1265 1266 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by 1267 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by 1268 * possible control vq. 1269 */ 1270 total_vqs = vi->max_queue_pairs * 2 + 1271 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); 1272 1273 /* Allocate space for find_vqs parameters */ 1274 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); 1275 if (!vqs) 1276 goto err_vq; 1277 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); 1278 if (!callbacks) 1279 goto err_callback; 1280 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); 1281 if (!names) 1282 goto err_names; 1283 1284 /* Parameters for control virtqueue, if any */ 1285 if (vi->has_cvq) { 1286 callbacks[total_vqs - 1] = NULL; 1287 names[total_vqs - 1] = "control"; 1288 } 1289 1290 /* Allocate/initialize parameters for send/receive virtqueues */ 1291 for (i = 0; i < vi->max_queue_pairs; i++) { 1292 callbacks[rxq2vq(i)] = skb_recv_done; 1293 callbacks[txq2vq(i)] = skb_xmit_done; 1294 sprintf(vi->rq[i].name, "input.%d", i); 1295 sprintf(vi->sq[i].name, "output.%d", i); 1296 names[rxq2vq(i)] = vi->rq[i].name; 1297 names[txq2vq(i)] = vi->sq[i].name; 1298 } 1299 1300 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, 1301 names); 1302 if (ret) 1303 goto err_find; 1304 1305 if (vi->has_cvq) { 1306 vi->cvq = vqs[total_vqs - 1]; 1307 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1308 vi->dev->features |= NETIF_F_HW_VLAN_FILTER; 1309 } 1310 1311 for (i = 0; i < vi->max_queue_pairs; i++) { 1312 vi->rq[i].vq = vqs[rxq2vq(i)]; 1313 vi->sq[i].vq = vqs[txq2vq(i)]; 1314 } 1315 1316 kfree(names); 1317 kfree(callbacks); 1318 kfree(vqs); 1319 1320 return 0; 1321 1322 err_find: 1323 kfree(names); 1324 err_names: 1325 kfree(callbacks); 1326 err_callback: 1327 kfree(vqs); 1328 err_vq: 1329 return ret; 1330 } 1331 1332 static int virtnet_alloc_queues(struct virtnet_info *vi) 1333 { 1334 int i; 1335 1336 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL); 1337 if (!vi->sq) 1338 goto err_sq; 1339 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL); 1340 if (!vi->rq) 1341 goto err_rq; 1342 1343 INIT_DELAYED_WORK(&vi->refill, refill_work); 1344 for (i = 0; i < vi->max_queue_pairs; i++) { 1345 vi->rq[i].pages = NULL; 1346 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll, 1347 napi_weight); 1348 1349 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); 1350 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); 1351 } 1352 1353 return 0; 1354 1355 err_rq: 1356 kfree(vi->sq); 1357 err_sq: 1358 return -ENOMEM; 1359 } 1360 1361 static int init_vqs(struct virtnet_info *vi) 1362 { 1363 int ret; 1364 1365 /* Allocate send & receive queues */ 1366 ret = virtnet_alloc_queues(vi); 1367 if (ret) 1368 goto err; 1369 1370 ret = virtnet_find_vqs(vi); 1371 if (ret) 1372 goto err_free; 1373 1374 virtnet_set_affinity(vi, true); 1375 return 0; 1376 1377 err_free: 1378 virtnet_free_queues(vi); 1379 err: 1380 return ret; 1381 } 1382 1383 static int virtnet_probe(struct virtio_device *vdev) 1384 { 1385 int i, err; 1386 struct net_device *dev; 1387 struct virtnet_info *vi; 1388 u16 max_queue_pairs; 1389 1390 /* Find if host supports multiqueue virtio_net device */ 1391 err = virtio_config_val(vdev, VIRTIO_NET_F_MQ, 1392 offsetof(struct virtio_net_config, 1393 max_virtqueue_pairs), &max_queue_pairs); 1394 1395 /* We need at least 2 queue's */ 1396 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN || 1397 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX || 1398 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1399 max_queue_pairs = 1; 1400 1401 /* Allocate ourselves a network device with room for our info */ 1402 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); 1403 if (!dev) 1404 return -ENOMEM; 1405 1406 /* Set up network device as normal. */ 1407 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE; 1408 dev->netdev_ops = &virtnet_netdev; 1409 dev->features = NETIF_F_HIGHDMA; 1410 1411 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 1412 SET_NETDEV_DEV(dev, &vdev->dev); 1413 1414 /* Do we support "hardware" checksums? */ 1415 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 1416 /* This opens up the world of extra features. */ 1417 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1418 if (csum) 1419 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1420 1421 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 1422 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 1423 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 1424 } 1425 /* Individual feature bits: what can host handle? */ 1426 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 1427 dev->hw_features |= NETIF_F_TSO; 1428 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 1429 dev->hw_features |= NETIF_F_TSO6; 1430 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 1431 dev->hw_features |= NETIF_F_TSO_ECN; 1432 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1433 dev->hw_features |= NETIF_F_UFO; 1434 1435 if (gso) 1436 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1437 /* (!csum && gso) case will be fixed by register_netdev() */ 1438 } 1439 1440 /* Configuration may specify what MAC to use. Otherwise random. */ 1441 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC, 1442 offsetof(struct virtio_net_config, mac), 1443 dev->dev_addr, dev->addr_len) < 0) 1444 eth_hw_addr_random(dev); 1445 1446 /* Set up our device-specific information */ 1447 vi = netdev_priv(dev); 1448 vi->dev = dev; 1449 vi->vdev = vdev; 1450 vdev->priv = vi; 1451 vi->stats = alloc_percpu(struct virtnet_stats); 1452 err = -ENOMEM; 1453 if (vi->stats == NULL) 1454 goto free; 1455 1456 mutex_init(&vi->config_lock); 1457 vi->config_enable = true; 1458 INIT_WORK(&vi->config_work, virtnet_config_changed_work); 1459 1460 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1461 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1462 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1463 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1464 vi->big_packets = true; 1465 1466 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1467 vi->mergeable_rx_bufs = true; 1468 1469 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1470 vi->has_cvq = true; 1471 1472 /* Use single tx/rx queue pair as default */ 1473 vi->curr_queue_pairs = 1; 1474 vi->max_queue_pairs = max_queue_pairs; 1475 1476 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ 1477 err = init_vqs(vi); 1478 if (err) 1479 goto free_stats; 1480 1481 netif_set_real_num_tx_queues(dev, 1); 1482 netif_set_real_num_rx_queues(dev, 1); 1483 1484 err = register_netdev(dev); 1485 if (err) { 1486 pr_debug("virtio_net: registering device failed\n"); 1487 goto free_vqs; 1488 } 1489 1490 /* Last of all, set up some receive buffers. */ 1491 for (i = 0; i < vi->max_queue_pairs; i++) { 1492 try_fill_recv(&vi->rq[i], GFP_KERNEL); 1493 1494 /* If we didn't even get one input buffer, we're useless. */ 1495 if (vi->rq[i].num == 0) { 1496 free_unused_bufs(vi); 1497 err = -ENOMEM; 1498 goto free_recv_bufs; 1499 } 1500 } 1501 1502 /* Assume link up if device can't report link status, 1503 otherwise get link status from config. */ 1504 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1505 netif_carrier_off(dev); 1506 schedule_work(&vi->config_work); 1507 } else { 1508 vi->status = VIRTIO_NET_S_LINK_UP; 1509 netif_carrier_on(dev); 1510 } 1511 1512 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", 1513 dev->name, max_queue_pairs); 1514 1515 return 0; 1516 1517 free_recv_bufs: 1518 free_receive_bufs(vi); 1519 unregister_netdev(dev); 1520 free_vqs: 1521 cancel_delayed_work_sync(&vi->refill); 1522 virtnet_del_vqs(vi); 1523 free_stats: 1524 free_percpu(vi->stats); 1525 free: 1526 free_netdev(dev); 1527 return err; 1528 } 1529 1530 static void remove_vq_common(struct virtnet_info *vi) 1531 { 1532 vi->vdev->config->reset(vi->vdev); 1533 1534 /* Free unused buffers in both send and recv, if any. */ 1535 free_unused_bufs(vi); 1536 1537 free_receive_bufs(vi); 1538 1539 virtnet_del_vqs(vi); 1540 } 1541 1542 static void virtnet_remove(struct virtio_device *vdev) 1543 { 1544 struct virtnet_info *vi = vdev->priv; 1545 1546 /* Prevent config work handler from accessing the device. */ 1547 mutex_lock(&vi->config_lock); 1548 vi->config_enable = false; 1549 mutex_unlock(&vi->config_lock); 1550 1551 unregister_netdev(vi->dev); 1552 1553 remove_vq_common(vi); 1554 1555 flush_work(&vi->config_work); 1556 1557 free_percpu(vi->stats); 1558 free_netdev(vi->dev); 1559 } 1560 1561 #ifdef CONFIG_PM 1562 static int virtnet_freeze(struct virtio_device *vdev) 1563 { 1564 struct virtnet_info *vi = vdev->priv; 1565 int i; 1566 1567 /* Prevent config work handler from accessing the device */ 1568 mutex_lock(&vi->config_lock); 1569 vi->config_enable = false; 1570 mutex_unlock(&vi->config_lock); 1571 1572 netif_device_detach(vi->dev); 1573 cancel_delayed_work_sync(&vi->refill); 1574 1575 if (netif_running(vi->dev)) 1576 for (i = 0; i < vi->max_queue_pairs; i++) { 1577 napi_disable(&vi->rq[i].napi); 1578 netif_napi_del(&vi->rq[i].napi); 1579 } 1580 1581 remove_vq_common(vi); 1582 1583 flush_work(&vi->config_work); 1584 1585 return 0; 1586 } 1587 1588 static int virtnet_restore(struct virtio_device *vdev) 1589 { 1590 struct virtnet_info *vi = vdev->priv; 1591 int err, i; 1592 1593 err = init_vqs(vi); 1594 if (err) 1595 return err; 1596 1597 if (netif_running(vi->dev)) 1598 for (i = 0; i < vi->max_queue_pairs; i++) 1599 virtnet_napi_enable(&vi->rq[i]); 1600 1601 netif_device_attach(vi->dev); 1602 1603 for (i = 0; i < vi->max_queue_pairs; i++) 1604 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 1605 schedule_delayed_work(&vi->refill, 0); 1606 1607 mutex_lock(&vi->config_lock); 1608 vi->config_enable = true; 1609 mutex_unlock(&vi->config_lock); 1610 1611 virtnet_set_queues(vi, vi->curr_queue_pairs); 1612 1613 return 0; 1614 } 1615 #endif 1616 1617 static struct virtio_device_id id_table[] = { 1618 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1619 { 0 }, 1620 }; 1621 1622 static unsigned int features[] = { 1623 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1624 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1625 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1626 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1627 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1628 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1629 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1630 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, 1631 }; 1632 1633 static struct virtio_driver virtio_net_driver = { 1634 .feature_table = features, 1635 .feature_table_size = ARRAY_SIZE(features), 1636 .driver.name = KBUILD_MODNAME, 1637 .driver.owner = THIS_MODULE, 1638 .id_table = id_table, 1639 .probe = virtnet_probe, 1640 .remove = virtnet_remove, 1641 .config_changed = virtnet_config_changed, 1642 #ifdef CONFIG_PM 1643 .freeze = virtnet_freeze, 1644 .restore = virtnet_restore, 1645 #endif 1646 }; 1647 1648 static int __init init(void) 1649 { 1650 return register_virtio_driver(&virtio_net_driver); 1651 } 1652 1653 static void __exit fini(void) 1654 { 1655 unregister_virtio_driver(&virtio_net_driver); 1656 } 1657 module_init(init); 1658 module_exit(fini); 1659 1660 MODULE_DEVICE_TABLE(virtio, id_table); 1661 MODULE_DESCRIPTION("Virtio network driver"); 1662 MODULE_LICENSE("GPL"); 1663