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