1 /* A network driver using virtio. 2 * 3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 //#define DEBUG 20 #include <linux/netdevice.h> 21 #include <linux/etherdevice.h> 22 #include <linux/ethtool.h> 23 #include <linux/module.h> 24 #include <linux/virtio.h> 25 #include <linux/virtio_net.h> 26 #include <linux/scatterlist.h> 27 #include <linux/if_vlan.h> 28 #include <linux/slab.h> 29 #include <linux/cpu.h> 30 31 static int napi_weight = 128; 32 module_param(napi_weight, int, 0444); 33 34 static bool csum = true, gso = true; 35 module_param(csum, bool, 0444); 36 module_param(gso, bool, 0444); 37 38 /* FIXME: MTU in config. */ 39 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) 40 #define GOOD_COPY_LEN 128 41 42 #define VIRTNET_SEND_COMMAND_SG_MAX 2 43 #define VIRTNET_DRIVER_VERSION "1.0.0" 44 45 struct virtnet_stats { 46 struct u64_stats_sync tx_syncp; 47 struct u64_stats_sync rx_syncp; 48 u64 tx_bytes; 49 u64 tx_packets; 50 51 u64 rx_bytes; 52 u64 rx_packets; 53 }; 54 55 /* Internal representation of a send virtqueue */ 56 struct send_queue { 57 /* Virtqueue associated with this send _queue */ 58 struct virtqueue *vq; 59 60 /* TX: fragments + linear part + virtio header */ 61 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 62 63 /* Name of the send queue: output.$index */ 64 char name[40]; 65 }; 66 67 /* Internal representation of a receive virtqueue */ 68 struct receive_queue { 69 /* Virtqueue associated with this receive_queue */ 70 struct virtqueue *vq; 71 72 struct napi_struct napi; 73 74 /* Number of input buffers, and max we've ever had. */ 75 unsigned int num, max; 76 77 /* Chain pages by the private ptr. */ 78 struct page *pages; 79 80 /* RX: fragments + linear part + virtio header */ 81 struct scatterlist sg[MAX_SKB_FRAGS + 2]; 82 83 /* Name of this receive queue: input.$index */ 84 char name[40]; 85 }; 86 87 struct virtnet_info { 88 struct virtio_device *vdev; 89 struct virtqueue *cvq; 90 struct net_device *dev; 91 struct send_queue *sq; 92 struct receive_queue *rq; 93 unsigned int status; 94 95 /* Max # of queue pairs supported by the device */ 96 u16 max_queue_pairs; 97 98 /* # of queue pairs currently used by the driver */ 99 u16 curr_queue_pairs; 100 101 /* I like... big packets and I cannot lie! */ 102 bool big_packets; 103 104 /* Host will merge rx buffers for big packets (shake it! shake it!) */ 105 bool mergeable_rx_bufs; 106 107 /* Has control virtqueue */ 108 bool has_cvq; 109 110 /* enable config space updates */ 111 bool config_enable; 112 113 /* Active statistics */ 114 struct virtnet_stats __percpu *stats; 115 116 /* Work struct for refilling if we run low on memory. */ 117 struct delayed_work refill; 118 119 /* Work struct for config space updates */ 120 struct work_struct config_work; 121 122 /* Lock for config space updates */ 123 struct mutex config_lock; 124 125 /* Does the affinity hint is set for virtqueues? */ 126 bool affinity_hint_set; 127 128 /* Per-cpu variable to show the mapping from CPU to virtqueue */ 129 int __percpu *vq_index; 130 131 /* CPU hot plug notifier */ 132 struct notifier_block nb; 133 }; 134 135 struct skb_vnet_hdr { 136 union { 137 struct virtio_net_hdr hdr; 138 struct virtio_net_hdr_mrg_rxbuf mhdr; 139 }; 140 }; 141 142 struct padded_vnet_hdr { 143 struct virtio_net_hdr hdr; 144 /* 145 * virtio_net_hdr should be in a separated sg buffer because of a 146 * QEMU bug, and data sg buffer shares same page with this header sg. 147 * This padding makes next sg 16 byte aligned after virtio_net_hdr. 148 */ 149 char padding[6]; 150 }; 151 152 /* Converting between virtqueue no. and kernel tx/rx queue no. 153 * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq 154 */ 155 static int vq2txq(struct virtqueue *vq) 156 { 157 return (virtqueue_get_queue_index(vq) - 1) / 2; 158 } 159 160 static int txq2vq(int txq) 161 { 162 return txq * 2 + 1; 163 } 164 165 static int vq2rxq(struct virtqueue *vq) 166 { 167 return virtqueue_get_queue_index(vq) / 2; 168 } 169 170 static int rxq2vq(int rxq) 171 { 172 return rxq * 2; 173 } 174 175 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) 176 { 177 return (struct skb_vnet_hdr *)skb->cb; 178 } 179 180 /* 181 * private is used to chain pages for big packets, put the whole 182 * most recent used list in the beginning for reuse 183 */ 184 static void give_pages(struct receive_queue *rq, struct page *page) 185 { 186 struct page *end; 187 188 /* Find end of list, sew whole thing into vi->rq.pages. */ 189 for (end = page; end->private; end = (struct page *)end->private); 190 end->private = (unsigned long)rq->pages; 191 rq->pages = page; 192 } 193 194 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) 195 { 196 struct page *p = rq->pages; 197 198 if (p) { 199 rq->pages = (struct page *)p->private; 200 /* clear private here, it is used to chain pages */ 201 p->private = 0; 202 } else 203 p = alloc_page(gfp_mask); 204 return p; 205 } 206 207 static void skb_xmit_done(struct virtqueue *vq) 208 { 209 struct virtnet_info *vi = vq->vdev->priv; 210 211 /* Suppress further interrupts. */ 212 virtqueue_disable_cb(vq); 213 214 /* We were probably waiting for more output buffers. */ 215 netif_wake_subqueue(vi->dev, vq2txq(vq)); 216 } 217 218 static void set_skb_frag(struct sk_buff *skb, struct page *page, 219 unsigned int offset, unsigned int *len) 220 { 221 int size = min((unsigned)PAGE_SIZE - offset, *len); 222 int i = skb_shinfo(skb)->nr_frags; 223 224 __skb_fill_page_desc(skb, i, page, offset, size); 225 226 skb->data_len += size; 227 skb->len += size; 228 skb->truesize += PAGE_SIZE; 229 skb_shinfo(skb)->nr_frags++; 230 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 231 *len -= size; 232 } 233 234 /* Called from bottom half context */ 235 static struct sk_buff *page_to_skb(struct receive_queue *rq, 236 struct page *page, unsigned int len) 237 { 238 struct virtnet_info *vi = rq->vq->vdev->priv; 239 struct sk_buff *skb; 240 struct skb_vnet_hdr *hdr; 241 unsigned int copy, hdr_len, offset; 242 char *p; 243 244 p = page_address(page); 245 246 /* copy small packet so we can reuse these pages for small data */ 247 skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); 248 if (unlikely(!skb)) 249 return NULL; 250 251 hdr = skb_vnet_hdr(skb); 252 253 if (vi->mergeable_rx_bufs) { 254 hdr_len = sizeof hdr->mhdr; 255 offset = hdr_len; 256 } else { 257 hdr_len = sizeof hdr->hdr; 258 offset = sizeof(struct padded_vnet_hdr); 259 } 260 261 memcpy(hdr, p, hdr_len); 262 263 len -= hdr_len; 264 p += offset; 265 266 copy = len; 267 if (copy > skb_tailroom(skb)) 268 copy = skb_tailroom(skb); 269 memcpy(skb_put(skb, copy), p, copy); 270 271 len -= copy; 272 offset += copy; 273 274 /* 275 * Verify that we can indeed put this data into a skb. 276 * This is here to handle cases when the device erroneously 277 * tries to receive more than is possible. This is usually 278 * the case of a broken device. 279 */ 280 if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { 281 net_dbg_ratelimited("%s: too much data\n", skb->dev->name); 282 dev_kfree_skb(skb); 283 return NULL; 284 } 285 286 while (len) { 287 set_skb_frag(skb, page, offset, &len); 288 page = (struct page *)page->private; 289 offset = 0; 290 } 291 292 if (page) 293 give_pages(rq, page); 294 295 return skb; 296 } 297 298 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb) 299 { 300 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 301 struct page *page; 302 int num_buf, i, len; 303 304 num_buf = hdr->mhdr.num_buffers; 305 while (--num_buf) { 306 i = skb_shinfo(skb)->nr_frags; 307 if (i >= MAX_SKB_FRAGS) { 308 pr_debug("%s: packet too long\n", skb->dev->name); 309 skb->dev->stats.rx_length_errors++; 310 return -EINVAL; 311 } 312 page = virtqueue_get_buf(rq->vq, &len); 313 if (!page) { 314 pr_debug("%s: rx error: %d buffers missing\n", 315 skb->dev->name, hdr->mhdr.num_buffers); 316 skb->dev->stats.rx_length_errors++; 317 return -EINVAL; 318 } 319 320 if (len > PAGE_SIZE) 321 len = PAGE_SIZE; 322 323 set_skb_frag(skb, page, 0, &len); 324 325 --rq->num; 326 } 327 return 0; 328 } 329 330 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) 331 { 332 struct virtnet_info *vi = rq->vq->vdev->priv; 333 struct net_device *dev = vi->dev; 334 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 335 struct sk_buff *skb; 336 struct page *page; 337 struct skb_vnet_hdr *hdr; 338 339 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { 340 pr_debug("%s: short packet %i\n", dev->name, len); 341 dev->stats.rx_length_errors++; 342 if (vi->mergeable_rx_bufs || vi->big_packets) 343 give_pages(rq, buf); 344 else 345 dev_kfree_skb(buf); 346 return; 347 } 348 349 if (!vi->mergeable_rx_bufs && !vi->big_packets) { 350 skb = buf; 351 len -= sizeof(struct virtio_net_hdr); 352 skb_trim(skb, len); 353 } else { 354 page = buf; 355 skb = page_to_skb(rq, page, len); 356 if (unlikely(!skb)) { 357 dev->stats.rx_dropped++; 358 give_pages(rq, page); 359 return; 360 } 361 if (vi->mergeable_rx_bufs) 362 if (receive_mergeable(rq, skb)) { 363 dev_kfree_skb(skb); 364 return; 365 } 366 } 367 368 hdr = skb_vnet_hdr(skb); 369 370 u64_stats_update_begin(&stats->rx_syncp); 371 stats->rx_bytes += skb->len; 372 stats->rx_packets++; 373 u64_stats_update_end(&stats->rx_syncp); 374 375 if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 376 pr_debug("Needs csum!\n"); 377 if (!skb_partial_csum_set(skb, 378 hdr->hdr.csum_start, 379 hdr->hdr.csum_offset)) 380 goto frame_err; 381 } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) { 382 skb->ip_summed = CHECKSUM_UNNECESSARY; 383 } 384 385 skb->protocol = eth_type_trans(skb, dev); 386 pr_debug("Receiving skb proto 0x%04x len %i type %i\n", 387 ntohs(skb->protocol), skb->len, skb->pkt_type); 388 389 if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { 390 pr_debug("GSO!\n"); 391 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 392 case VIRTIO_NET_HDR_GSO_TCPV4: 393 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; 394 break; 395 case VIRTIO_NET_HDR_GSO_UDP: 396 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 397 break; 398 case VIRTIO_NET_HDR_GSO_TCPV6: 399 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 400 break; 401 default: 402 net_warn_ratelimited("%s: bad gso type %u.\n", 403 dev->name, hdr->hdr.gso_type); 404 goto frame_err; 405 } 406 407 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) 408 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 409 410 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; 411 if (skb_shinfo(skb)->gso_size == 0) { 412 net_warn_ratelimited("%s: zero gso size.\n", dev->name); 413 goto frame_err; 414 } 415 416 /* Header must be checked, and gso_segs computed. */ 417 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 418 skb_shinfo(skb)->gso_segs = 0; 419 } 420 421 netif_receive_skb(skb); 422 return; 423 424 frame_err: 425 dev->stats.rx_frame_errors++; 426 dev_kfree_skb(skb); 427 } 428 429 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp) 430 { 431 struct virtnet_info *vi = rq->vq->vdev->priv; 432 struct sk_buff *skb; 433 struct skb_vnet_hdr *hdr; 434 int err; 435 436 skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp); 437 if (unlikely(!skb)) 438 return -ENOMEM; 439 440 skb_put(skb, MAX_PACKET_LEN); 441 442 hdr = skb_vnet_hdr(skb); 443 sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr); 444 445 skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); 446 447 err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp); 448 if (err < 0) 449 dev_kfree_skb(skb); 450 451 return err; 452 } 453 454 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp) 455 { 456 struct page *first, *list = NULL; 457 char *p; 458 int i, err, offset; 459 460 /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */ 461 for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { 462 first = get_a_page(rq, gfp); 463 if (!first) { 464 if (list) 465 give_pages(rq, list); 466 return -ENOMEM; 467 } 468 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE); 469 470 /* chain new page in list head to match sg */ 471 first->private = (unsigned long)list; 472 list = first; 473 } 474 475 first = get_a_page(rq, gfp); 476 if (!first) { 477 give_pages(rq, list); 478 return -ENOMEM; 479 } 480 p = page_address(first); 481 482 /* rq->sg[0], rq->sg[1] share the same page */ 483 /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */ 484 sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr)); 485 486 /* rq->sg[1] for data packet, from offset */ 487 offset = sizeof(struct padded_vnet_hdr); 488 sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset); 489 490 /* chain first in list head */ 491 first->private = (unsigned long)list; 492 err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2, 493 first, gfp); 494 if (err < 0) 495 give_pages(rq, first); 496 497 return err; 498 } 499 500 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp) 501 { 502 struct page *page; 503 int err; 504 505 page = get_a_page(rq, gfp); 506 if (!page) 507 return -ENOMEM; 508 509 sg_init_one(rq->sg, page_address(page), PAGE_SIZE); 510 511 err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp); 512 if (err < 0) 513 give_pages(rq, page); 514 515 return err; 516 } 517 518 /* 519 * Returns false if we couldn't fill entirely (OOM). 520 * 521 * Normally run in the receive path, but can also be run from ndo_open 522 * before we're receiving packets, or from refill_work which is 523 * careful to disable receiving (using napi_disable). 524 */ 525 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) 526 { 527 struct virtnet_info *vi = rq->vq->vdev->priv; 528 int err; 529 bool oom; 530 531 do { 532 if (vi->mergeable_rx_bufs) 533 err = add_recvbuf_mergeable(rq, gfp); 534 else if (vi->big_packets) 535 err = add_recvbuf_big(rq, gfp); 536 else 537 err = add_recvbuf_small(rq, gfp); 538 539 oom = err == -ENOMEM; 540 if (err) 541 break; 542 ++rq->num; 543 } while (rq->vq->num_free); 544 if (unlikely(rq->num > rq->max)) 545 rq->max = rq->num; 546 virtqueue_kick(rq->vq); 547 return !oom; 548 } 549 550 static void skb_recv_done(struct virtqueue *rvq) 551 { 552 struct virtnet_info *vi = rvq->vdev->priv; 553 struct receive_queue *rq = &vi->rq[vq2rxq(rvq)]; 554 555 /* Schedule NAPI, Suppress further interrupts if successful. */ 556 if (napi_schedule_prep(&rq->napi)) { 557 virtqueue_disable_cb(rvq); 558 __napi_schedule(&rq->napi); 559 } 560 } 561 562 static void virtnet_napi_enable(struct receive_queue *rq) 563 { 564 napi_enable(&rq->napi); 565 566 /* If all buffers were filled by other side before we napi_enabled, we 567 * won't get another interrupt, so process any outstanding packets 568 * now. virtnet_poll wants re-enable the queue, so we disable here. 569 * We synchronize against interrupts via NAPI_STATE_SCHED */ 570 if (napi_schedule_prep(&rq->napi)) { 571 virtqueue_disable_cb(rq->vq); 572 local_bh_disable(); 573 __napi_schedule(&rq->napi); 574 local_bh_enable(); 575 } 576 } 577 578 static void refill_work(struct work_struct *work) 579 { 580 struct virtnet_info *vi = 581 container_of(work, struct virtnet_info, refill.work); 582 bool still_empty; 583 int i; 584 585 for (i = 0; i < vi->max_queue_pairs; i++) { 586 struct receive_queue *rq = &vi->rq[i]; 587 588 napi_disable(&rq->napi); 589 still_empty = !try_fill_recv(rq, GFP_KERNEL); 590 virtnet_napi_enable(rq); 591 592 /* In theory, this can happen: if we don't get any buffers in 593 * we will *never* try to fill again. 594 */ 595 if (still_empty) 596 schedule_delayed_work(&vi->refill, HZ/2); 597 } 598 } 599 600 static int virtnet_poll(struct napi_struct *napi, int budget) 601 { 602 struct receive_queue *rq = 603 container_of(napi, struct receive_queue, napi); 604 struct virtnet_info *vi = rq->vq->vdev->priv; 605 void *buf; 606 unsigned int len, received = 0; 607 608 again: 609 while (received < budget && 610 (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) { 611 receive_buf(rq, buf, len); 612 --rq->num; 613 received++; 614 } 615 616 if (rq->num < rq->max / 2) { 617 if (!try_fill_recv(rq, GFP_ATOMIC)) 618 schedule_delayed_work(&vi->refill, 0); 619 } 620 621 /* Out of packets? */ 622 if (received < budget) { 623 napi_complete(napi); 624 if (unlikely(!virtqueue_enable_cb(rq->vq)) && 625 napi_schedule_prep(napi)) { 626 virtqueue_disable_cb(rq->vq); 627 __napi_schedule(napi); 628 goto again; 629 } 630 } 631 632 return received; 633 } 634 635 static int virtnet_open(struct net_device *dev) 636 { 637 struct virtnet_info *vi = netdev_priv(dev); 638 int i; 639 640 for (i = 0; i < vi->max_queue_pairs; i++) { 641 /* Make sure we have some buffers: if oom use wq. */ 642 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 643 schedule_delayed_work(&vi->refill, 0); 644 virtnet_napi_enable(&vi->rq[i]); 645 } 646 647 return 0; 648 } 649 650 static void free_old_xmit_skbs(struct send_queue *sq) 651 { 652 struct sk_buff *skb; 653 unsigned int len; 654 struct virtnet_info *vi = sq->vq->vdev->priv; 655 struct virtnet_stats *stats = this_cpu_ptr(vi->stats); 656 657 while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { 658 pr_debug("Sent skb %p\n", skb); 659 660 u64_stats_update_begin(&stats->tx_syncp); 661 stats->tx_bytes += skb->len; 662 stats->tx_packets++; 663 u64_stats_update_end(&stats->tx_syncp); 664 665 dev_kfree_skb_any(skb); 666 } 667 } 668 669 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) 670 { 671 struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); 672 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; 673 struct virtnet_info *vi = sq->vq->vdev->priv; 674 unsigned num_sg; 675 676 pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); 677 678 if (skb->ip_summed == CHECKSUM_PARTIAL) { 679 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 680 hdr->hdr.csum_start = skb_checksum_start_offset(skb); 681 hdr->hdr.csum_offset = skb->csum_offset; 682 } else { 683 hdr->hdr.flags = 0; 684 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; 685 } 686 687 if (skb_is_gso(skb)) { 688 hdr->hdr.hdr_len = skb_headlen(skb); 689 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; 690 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 691 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 692 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) 693 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 694 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 695 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; 696 else 697 BUG(); 698 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) 699 hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; 700 } else { 701 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; 702 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; 703 } 704 705 hdr->mhdr.num_buffers = 0; 706 707 /* Encode metadata header at front. */ 708 if (vi->mergeable_rx_bufs) 709 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr); 710 else 711 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr); 712 713 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1; 714 return virtqueue_add_buf(sq->vq, sq->sg, num_sg, 715 0, skb, GFP_ATOMIC); 716 } 717 718 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) 719 { 720 struct virtnet_info *vi = netdev_priv(dev); 721 int qnum = skb_get_queue_mapping(skb); 722 struct send_queue *sq = &vi->sq[qnum]; 723 int err; 724 725 /* Free up any pending old buffers before queueing new ones. */ 726 free_old_xmit_skbs(sq); 727 728 /* Try to transmit */ 729 err = xmit_skb(sq, skb); 730 731 /* This should not happen! */ 732 if (unlikely(err)) { 733 dev->stats.tx_fifo_errors++; 734 if (net_ratelimit()) 735 dev_warn(&dev->dev, 736 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err); 737 dev->stats.tx_dropped++; 738 kfree_skb(skb); 739 return NETDEV_TX_OK; 740 } 741 virtqueue_kick(sq->vq); 742 743 /* Don't wait up for transmitted skbs to be freed. */ 744 skb_orphan(skb); 745 nf_reset(skb); 746 747 /* Apparently nice girls don't return TX_BUSY; stop the queue 748 * before it gets out of hand. Naturally, this wastes entries. */ 749 if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { 750 netif_stop_subqueue(dev, qnum); 751 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { 752 /* More just got used, free them then recheck. */ 753 free_old_xmit_skbs(sq); 754 if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { 755 netif_start_subqueue(dev, qnum); 756 virtqueue_disable_cb(sq->vq); 757 } 758 } 759 } 760 761 return NETDEV_TX_OK; 762 } 763 764 /* 765 * Send command via the control virtqueue and check status. Commands 766 * supported by the hypervisor, as indicated by feature bits, should 767 * never fail unless improperly formated. 768 */ 769 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 770 struct scatterlist *data, int out, int in) 771 { 772 struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; 773 struct virtio_net_ctrl_hdr ctrl; 774 virtio_net_ctrl_ack status = ~0; 775 unsigned int tmp; 776 int i; 777 778 /* Caller should know better */ 779 BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || 780 (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); 781 782 out++; /* Add header */ 783 in++; /* Add return status */ 784 785 ctrl.class = class; 786 ctrl.cmd = cmd; 787 788 sg_init_table(sg, out + in); 789 790 sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); 791 for_each_sg(data, s, out + in - 2, i) 792 sg_set_buf(&sg[i + 1], sg_virt(s), s->length); 793 sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); 794 795 BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0); 796 797 virtqueue_kick(vi->cvq); 798 799 /* Spin for a response, the kick causes an ioport write, trapping 800 * into the hypervisor, so the request should be handled immediately. 801 */ 802 while (!virtqueue_get_buf(vi->cvq, &tmp)) 803 cpu_relax(); 804 805 return status == VIRTIO_NET_OK; 806 } 807 808 static int virtnet_set_mac_address(struct net_device *dev, void *p) 809 { 810 struct virtnet_info *vi = netdev_priv(dev); 811 struct virtio_device *vdev = vi->vdev; 812 int ret; 813 struct sockaddr *addr = p; 814 struct scatterlist sg; 815 816 ret = eth_prepare_mac_addr_change(dev, p); 817 if (ret) 818 return ret; 819 820 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) { 821 sg_init_one(&sg, addr->sa_data, dev->addr_len); 822 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 823 VIRTIO_NET_CTRL_MAC_ADDR_SET, 824 &sg, 1, 0)) { 825 dev_warn(&vdev->dev, 826 "Failed to set mac address by vq command.\n"); 827 return -EINVAL; 828 } 829 } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { 830 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), 831 addr->sa_data, dev->addr_len); 832 } 833 834 eth_commit_mac_addr_change(dev, p); 835 836 return 0; 837 } 838 839 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev, 840 struct rtnl_link_stats64 *tot) 841 { 842 struct virtnet_info *vi = netdev_priv(dev); 843 int cpu; 844 unsigned int start; 845 846 for_each_possible_cpu(cpu) { 847 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu); 848 u64 tpackets, tbytes, rpackets, rbytes; 849 850 do { 851 start = u64_stats_fetch_begin_bh(&stats->tx_syncp); 852 tpackets = stats->tx_packets; 853 tbytes = stats->tx_bytes; 854 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start)); 855 856 do { 857 start = u64_stats_fetch_begin_bh(&stats->rx_syncp); 858 rpackets = stats->rx_packets; 859 rbytes = stats->rx_bytes; 860 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start)); 861 862 tot->rx_packets += rpackets; 863 tot->tx_packets += tpackets; 864 tot->rx_bytes += rbytes; 865 tot->tx_bytes += tbytes; 866 } 867 868 tot->tx_dropped = dev->stats.tx_dropped; 869 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 870 tot->rx_dropped = dev->stats.rx_dropped; 871 tot->rx_length_errors = dev->stats.rx_length_errors; 872 tot->rx_frame_errors = dev->stats.rx_frame_errors; 873 874 return tot; 875 } 876 877 #ifdef CONFIG_NET_POLL_CONTROLLER 878 static void virtnet_netpoll(struct net_device *dev) 879 { 880 struct virtnet_info *vi = netdev_priv(dev); 881 int i; 882 883 for (i = 0; i < vi->curr_queue_pairs; i++) 884 napi_schedule(&vi->rq[i].napi); 885 } 886 #endif 887 888 static void virtnet_ack_link_announce(struct virtnet_info *vi) 889 { 890 rtnl_lock(); 891 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE, 892 VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, 893 0, 0)) 894 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n"); 895 rtnl_unlock(); 896 } 897 898 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) 899 { 900 struct scatterlist sg; 901 struct virtio_net_ctrl_mq s; 902 struct net_device *dev = vi->dev; 903 904 if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) 905 return 0; 906 907 s.virtqueue_pairs = queue_pairs; 908 sg_init_one(&sg, &s, sizeof(s)); 909 910 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ, 911 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){ 912 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n", 913 queue_pairs); 914 return -EINVAL; 915 } else 916 vi->curr_queue_pairs = queue_pairs; 917 918 return 0; 919 } 920 921 static int virtnet_close(struct net_device *dev) 922 { 923 struct virtnet_info *vi = netdev_priv(dev); 924 int i; 925 926 /* Make sure refill_work doesn't re-enable napi! */ 927 cancel_delayed_work_sync(&vi->refill); 928 929 for (i = 0; i < vi->max_queue_pairs; i++) 930 napi_disable(&vi->rq[i].napi); 931 932 return 0; 933 } 934 935 static void virtnet_set_rx_mode(struct net_device *dev) 936 { 937 struct virtnet_info *vi = netdev_priv(dev); 938 struct scatterlist sg[2]; 939 u8 promisc, allmulti; 940 struct virtio_net_ctrl_mac *mac_data; 941 struct netdev_hw_addr *ha; 942 int uc_count; 943 int mc_count; 944 void *buf; 945 int i; 946 947 /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ 948 if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) 949 return; 950 951 promisc = ((dev->flags & IFF_PROMISC) != 0); 952 allmulti = ((dev->flags & IFF_ALLMULTI) != 0); 953 954 sg_init_one(sg, &promisc, sizeof(promisc)); 955 956 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 957 VIRTIO_NET_CTRL_RX_PROMISC, 958 sg, 1, 0)) 959 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", 960 promisc ? "en" : "dis"); 961 962 sg_init_one(sg, &allmulti, sizeof(allmulti)); 963 964 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, 965 VIRTIO_NET_CTRL_RX_ALLMULTI, 966 sg, 1, 0)) 967 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", 968 allmulti ? "en" : "dis"); 969 970 uc_count = netdev_uc_count(dev); 971 mc_count = netdev_mc_count(dev); 972 /* MAC filter - use one buffer for both lists */ 973 buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + 974 (2 * sizeof(mac_data->entries)), GFP_ATOMIC); 975 mac_data = buf; 976 if (!buf) 977 return; 978 979 sg_init_table(sg, 2); 980 981 /* Store the unicast list and count in the front of the buffer */ 982 mac_data->entries = uc_count; 983 i = 0; 984 netdev_for_each_uc_addr(ha, dev) 985 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 986 987 sg_set_buf(&sg[0], mac_data, 988 sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); 989 990 /* multicast list and count fill the end */ 991 mac_data = (void *)&mac_data->macs[uc_count][0]; 992 993 mac_data->entries = mc_count; 994 i = 0; 995 netdev_for_each_mc_addr(ha, dev) 996 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); 997 998 sg_set_buf(&sg[1], mac_data, 999 sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); 1000 1001 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, 1002 VIRTIO_NET_CTRL_MAC_TABLE_SET, 1003 sg, 2, 0)) 1004 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); 1005 1006 kfree(buf); 1007 } 1008 1009 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) 1010 { 1011 struct virtnet_info *vi = netdev_priv(dev); 1012 struct scatterlist sg; 1013 1014 sg_init_one(&sg, &vid, sizeof(vid)); 1015 1016 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1017 VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) 1018 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); 1019 return 0; 1020 } 1021 1022 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) 1023 { 1024 struct virtnet_info *vi = netdev_priv(dev); 1025 struct scatterlist sg; 1026 1027 sg_init_one(&sg, &vid, sizeof(vid)); 1028 1029 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, 1030 VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) 1031 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); 1032 return 0; 1033 } 1034 1035 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu) 1036 { 1037 int i; 1038 int cpu; 1039 1040 if (vi->affinity_hint_set) { 1041 for (i = 0; i < vi->max_queue_pairs; i++) { 1042 virtqueue_set_affinity(vi->rq[i].vq, -1); 1043 virtqueue_set_affinity(vi->sq[i].vq, -1); 1044 } 1045 1046 vi->affinity_hint_set = false; 1047 } 1048 1049 i = 0; 1050 for_each_online_cpu(cpu) { 1051 if (cpu == hcpu) { 1052 *per_cpu_ptr(vi->vq_index, cpu) = -1; 1053 } else { 1054 *per_cpu_ptr(vi->vq_index, cpu) = 1055 ++i % vi->curr_queue_pairs; 1056 } 1057 } 1058 } 1059 1060 static void virtnet_set_affinity(struct virtnet_info *vi) 1061 { 1062 int i; 1063 int cpu; 1064 1065 /* In multiqueue mode, when the number of cpu is equal to the number of 1066 * queue pairs, we let the queue pairs to be private to one cpu by 1067 * setting the affinity hint to eliminate the contention. 1068 */ 1069 if (vi->curr_queue_pairs == 1 || 1070 vi->max_queue_pairs != num_online_cpus()) { 1071 virtnet_clean_affinity(vi, -1); 1072 return; 1073 } 1074 1075 i = 0; 1076 for_each_online_cpu(cpu) { 1077 virtqueue_set_affinity(vi->rq[i].vq, cpu); 1078 virtqueue_set_affinity(vi->sq[i].vq, cpu); 1079 *per_cpu_ptr(vi->vq_index, cpu) = i; 1080 i++; 1081 } 1082 1083 vi->affinity_hint_set = true; 1084 } 1085 1086 static int virtnet_cpu_callback(struct notifier_block *nfb, 1087 unsigned long action, void *hcpu) 1088 { 1089 struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb); 1090 1091 switch(action & ~CPU_TASKS_FROZEN) { 1092 case CPU_ONLINE: 1093 case CPU_DOWN_FAILED: 1094 case CPU_DEAD: 1095 virtnet_set_affinity(vi); 1096 break; 1097 case CPU_DOWN_PREPARE: 1098 virtnet_clean_affinity(vi, (long)hcpu); 1099 break; 1100 default: 1101 break; 1102 } 1103 return NOTIFY_OK; 1104 } 1105 1106 static void virtnet_get_ringparam(struct net_device *dev, 1107 struct ethtool_ringparam *ring) 1108 { 1109 struct virtnet_info *vi = netdev_priv(dev); 1110 1111 ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq); 1112 ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq); 1113 ring->rx_pending = ring->rx_max_pending; 1114 ring->tx_pending = ring->tx_max_pending; 1115 } 1116 1117 1118 static void virtnet_get_drvinfo(struct net_device *dev, 1119 struct ethtool_drvinfo *info) 1120 { 1121 struct virtnet_info *vi = netdev_priv(dev); 1122 struct virtio_device *vdev = vi->vdev; 1123 1124 strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); 1125 strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version)); 1126 strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info)); 1127 1128 } 1129 1130 /* TODO: Eliminate OOO packets during switching */ 1131 static int virtnet_set_channels(struct net_device *dev, 1132 struct ethtool_channels *channels) 1133 { 1134 struct virtnet_info *vi = netdev_priv(dev); 1135 u16 queue_pairs = channels->combined_count; 1136 int err; 1137 1138 /* We don't support separate rx/tx channels. 1139 * We don't allow setting 'other' channels. 1140 */ 1141 if (channels->rx_count || channels->tx_count || channels->other_count) 1142 return -EINVAL; 1143 1144 if (queue_pairs > vi->max_queue_pairs) 1145 return -EINVAL; 1146 1147 get_online_cpus(); 1148 err = virtnet_set_queues(vi, queue_pairs); 1149 if (!err) { 1150 netif_set_real_num_tx_queues(dev, queue_pairs); 1151 netif_set_real_num_rx_queues(dev, queue_pairs); 1152 1153 virtnet_set_affinity(vi); 1154 } 1155 put_online_cpus(); 1156 1157 return err; 1158 } 1159 1160 static void virtnet_get_channels(struct net_device *dev, 1161 struct ethtool_channels *channels) 1162 { 1163 struct virtnet_info *vi = netdev_priv(dev); 1164 1165 channels->combined_count = vi->curr_queue_pairs; 1166 channels->max_combined = vi->max_queue_pairs; 1167 channels->max_other = 0; 1168 channels->rx_count = 0; 1169 channels->tx_count = 0; 1170 channels->other_count = 0; 1171 } 1172 1173 static const struct ethtool_ops virtnet_ethtool_ops = { 1174 .get_drvinfo = virtnet_get_drvinfo, 1175 .get_link = ethtool_op_get_link, 1176 .get_ringparam = virtnet_get_ringparam, 1177 .set_channels = virtnet_set_channels, 1178 .get_channels = virtnet_get_channels, 1179 }; 1180 1181 #define MIN_MTU 68 1182 #define MAX_MTU 65535 1183 1184 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) 1185 { 1186 if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) 1187 return -EINVAL; 1188 dev->mtu = new_mtu; 1189 return 0; 1190 } 1191 1192 /* To avoid contending a lock hold by a vcpu who would exit to host, select the 1193 * txq based on the processor id. 1194 */ 1195 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb) 1196 { 1197 int txq; 1198 struct virtnet_info *vi = netdev_priv(dev); 1199 1200 if (skb_rx_queue_recorded(skb)) { 1201 txq = skb_get_rx_queue(skb); 1202 } else { 1203 txq = *__this_cpu_ptr(vi->vq_index); 1204 if (txq == -1) 1205 txq = 0; 1206 } 1207 1208 while (unlikely(txq >= dev->real_num_tx_queues)) 1209 txq -= dev->real_num_tx_queues; 1210 1211 return txq; 1212 } 1213 1214 static const struct net_device_ops virtnet_netdev = { 1215 .ndo_open = virtnet_open, 1216 .ndo_stop = virtnet_close, 1217 .ndo_start_xmit = start_xmit, 1218 .ndo_validate_addr = eth_validate_addr, 1219 .ndo_set_mac_address = virtnet_set_mac_address, 1220 .ndo_set_rx_mode = virtnet_set_rx_mode, 1221 .ndo_change_mtu = virtnet_change_mtu, 1222 .ndo_get_stats64 = virtnet_stats, 1223 .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, 1224 .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, 1225 .ndo_select_queue = virtnet_select_queue, 1226 #ifdef CONFIG_NET_POLL_CONTROLLER 1227 .ndo_poll_controller = virtnet_netpoll, 1228 #endif 1229 }; 1230 1231 static void virtnet_config_changed_work(struct work_struct *work) 1232 { 1233 struct virtnet_info *vi = 1234 container_of(work, struct virtnet_info, config_work); 1235 u16 v; 1236 1237 mutex_lock(&vi->config_lock); 1238 if (!vi->config_enable) 1239 goto done; 1240 1241 if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS, 1242 offsetof(struct virtio_net_config, status), 1243 &v) < 0) 1244 goto done; 1245 1246 if (v & VIRTIO_NET_S_ANNOUNCE) { 1247 netdev_notify_peers(vi->dev); 1248 virtnet_ack_link_announce(vi); 1249 } 1250 1251 /* Ignore unknown (future) status bits */ 1252 v &= VIRTIO_NET_S_LINK_UP; 1253 1254 if (vi->status == v) 1255 goto done; 1256 1257 vi->status = v; 1258 1259 if (vi->status & VIRTIO_NET_S_LINK_UP) { 1260 netif_carrier_on(vi->dev); 1261 netif_tx_wake_all_queues(vi->dev); 1262 } else { 1263 netif_carrier_off(vi->dev); 1264 netif_tx_stop_all_queues(vi->dev); 1265 } 1266 done: 1267 mutex_unlock(&vi->config_lock); 1268 } 1269 1270 static void virtnet_config_changed(struct virtio_device *vdev) 1271 { 1272 struct virtnet_info *vi = vdev->priv; 1273 1274 schedule_work(&vi->config_work); 1275 } 1276 1277 static void virtnet_free_queues(struct virtnet_info *vi) 1278 { 1279 kfree(vi->rq); 1280 kfree(vi->sq); 1281 } 1282 1283 static void free_receive_bufs(struct virtnet_info *vi) 1284 { 1285 int i; 1286 1287 for (i = 0; i < vi->max_queue_pairs; i++) { 1288 while (vi->rq[i].pages) 1289 __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0); 1290 } 1291 } 1292 1293 static void free_unused_bufs(struct virtnet_info *vi) 1294 { 1295 void *buf; 1296 int i; 1297 1298 for (i = 0; i < vi->max_queue_pairs; i++) { 1299 struct virtqueue *vq = vi->sq[i].vq; 1300 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) 1301 dev_kfree_skb(buf); 1302 } 1303 1304 for (i = 0; i < vi->max_queue_pairs; i++) { 1305 struct virtqueue *vq = vi->rq[i].vq; 1306 1307 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) { 1308 if (vi->mergeable_rx_bufs || vi->big_packets) 1309 give_pages(&vi->rq[i], buf); 1310 else 1311 dev_kfree_skb(buf); 1312 --vi->rq[i].num; 1313 } 1314 BUG_ON(vi->rq[i].num != 0); 1315 } 1316 } 1317 1318 static void virtnet_del_vqs(struct virtnet_info *vi) 1319 { 1320 struct virtio_device *vdev = vi->vdev; 1321 1322 virtnet_clean_affinity(vi, -1); 1323 1324 vdev->config->del_vqs(vdev); 1325 1326 virtnet_free_queues(vi); 1327 } 1328 1329 static int virtnet_find_vqs(struct virtnet_info *vi) 1330 { 1331 vq_callback_t **callbacks; 1332 struct virtqueue **vqs; 1333 int ret = -ENOMEM; 1334 int i, total_vqs; 1335 const char **names; 1336 1337 /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by 1338 * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by 1339 * possible control vq. 1340 */ 1341 total_vqs = vi->max_queue_pairs * 2 + 1342 virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ); 1343 1344 /* Allocate space for find_vqs parameters */ 1345 vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL); 1346 if (!vqs) 1347 goto err_vq; 1348 callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL); 1349 if (!callbacks) 1350 goto err_callback; 1351 names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL); 1352 if (!names) 1353 goto err_names; 1354 1355 /* Parameters for control virtqueue, if any */ 1356 if (vi->has_cvq) { 1357 callbacks[total_vqs - 1] = NULL; 1358 names[total_vqs - 1] = "control"; 1359 } 1360 1361 /* Allocate/initialize parameters for send/receive virtqueues */ 1362 for (i = 0; i < vi->max_queue_pairs; i++) { 1363 callbacks[rxq2vq(i)] = skb_recv_done; 1364 callbacks[txq2vq(i)] = skb_xmit_done; 1365 sprintf(vi->rq[i].name, "input.%d", i); 1366 sprintf(vi->sq[i].name, "output.%d", i); 1367 names[rxq2vq(i)] = vi->rq[i].name; 1368 names[txq2vq(i)] = vi->sq[i].name; 1369 } 1370 1371 ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, 1372 names); 1373 if (ret) 1374 goto err_find; 1375 1376 if (vi->has_cvq) { 1377 vi->cvq = vqs[total_vqs - 1]; 1378 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) 1379 vi->dev->features |= NETIF_F_HW_VLAN_FILTER; 1380 } 1381 1382 for (i = 0; i < vi->max_queue_pairs; i++) { 1383 vi->rq[i].vq = vqs[rxq2vq(i)]; 1384 vi->sq[i].vq = vqs[txq2vq(i)]; 1385 } 1386 1387 kfree(names); 1388 kfree(callbacks); 1389 kfree(vqs); 1390 1391 return 0; 1392 1393 err_find: 1394 kfree(names); 1395 err_names: 1396 kfree(callbacks); 1397 err_callback: 1398 kfree(vqs); 1399 err_vq: 1400 return ret; 1401 } 1402 1403 static int virtnet_alloc_queues(struct virtnet_info *vi) 1404 { 1405 int i; 1406 1407 vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL); 1408 if (!vi->sq) 1409 goto err_sq; 1410 vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL); 1411 if (!vi->rq) 1412 goto err_rq; 1413 1414 INIT_DELAYED_WORK(&vi->refill, refill_work); 1415 for (i = 0; i < vi->max_queue_pairs; i++) { 1416 vi->rq[i].pages = NULL; 1417 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll, 1418 napi_weight); 1419 1420 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); 1421 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); 1422 } 1423 1424 return 0; 1425 1426 err_rq: 1427 kfree(vi->sq); 1428 err_sq: 1429 return -ENOMEM; 1430 } 1431 1432 static int init_vqs(struct virtnet_info *vi) 1433 { 1434 int ret; 1435 1436 /* Allocate send & receive queues */ 1437 ret = virtnet_alloc_queues(vi); 1438 if (ret) 1439 goto err; 1440 1441 ret = virtnet_find_vqs(vi); 1442 if (ret) 1443 goto err_free; 1444 1445 get_online_cpus(); 1446 virtnet_set_affinity(vi); 1447 put_online_cpus(); 1448 1449 return 0; 1450 1451 err_free: 1452 virtnet_free_queues(vi); 1453 err: 1454 return ret; 1455 } 1456 1457 static int virtnet_probe(struct virtio_device *vdev) 1458 { 1459 int i, err; 1460 struct net_device *dev; 1461 struct virtnet_info *vi; 1462 u16 max_queue_pairs; 1463 1464 /* Find if host supports multiqueue virtio_net device */ 1465 err = virtio_config_val(vdev, VIRTIO_NET_F_MQ, 1466 offsetof(struct virtio_net_config, 1467 max_virtqueue_pairs), &max_queue_pairs); 1468 1469 /* We need at least 2 queue's */ 1470 if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN || 1471 max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX || 1472 !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1473 max_queue_pairs = 1; 1474 1475 /* Allocate ourselves a network device with room for our info */ 1476 dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs); 1477 if (!dev) 1478 return -ENOMEM; 1479 1480 /* Set up network device as normal. */ 1481 dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE; 1482 dev->netdev_ops = &virtnet_netdev; 1483 dev->features = NETIF_F_HIGHDMA; 1484 1485 SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); 1486 SET_NETDEV_DEV(dev, &vdev->dev); 1487 1488 /* Do we support "hardware" checksums? */ 1489 if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { 1490 /* This opens up the world of extra features. */ 1491 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1492 if (csum) 1493 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; 1494 1495 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { 1496 dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO 1497 | NETIF_F_TSO_ECN | NETIF_F_TSO6; 1498 } 1499 /* Individual feature bits: what can host handle? */ 1500 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) 1501 dev->hw_features |= NETIF_F_TSO; 1502 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) 1503 dev->hw_features |= NETIF_F_TSO6; 1504 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) 1505 dev->hw_features |= NETIF_F_TSO_ECN; 1506 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) 1507 dev->hw_features |= NETIF_F_UFO; 1508 1509 if (gso) 1510 dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); 1511 /* (!csum && gso) case will be fixed by register_netdev() */ 1512 } 1513 1514 /* Configuration may specify what MAC to use. Otherwise random. */ 1515 if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC, 1516 offsetof(struct virtio_net_config, mac), 1517 dev->dev_addr, dev->addr_len) < 0) 1518 eth_hw_addr_random(dev); 1519 1520 /* Set up our device-specific information */ 1521 vi = netdev_priv(dev); 1522 vi->dev = dev; 1523 vi->vdev = vdev; 1524 vdev->priv = vi; 1525 vi->stats = alloc_percpu(struct virtnet_stats); 1526 err = -ENOMEM; 1527 if (vi->stats == NULL) 1528 goto free; 1529 1530 vi->vq_index = alloc_percpu(int); 1531 if (vi->vq_index == NULL) 1532 goto free_stats; 1533 1534 mutex_init(&vi->config_lock); 1535 vi->config_enable = true; 1536 INIT_WORK(&vi->config_work, virtnet_config_changed_work); 1537 1538 /* If we can receive ANY GSO packets, we must allocate large ones. */ 1539 if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || 1540 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || 1541 virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) 1542 vi->big_packets = true; 1543 1544 if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) 1545 vi->mergeable_rx_bufs = true; 1546 1547 if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) 1548 vi->has_cvq = true; 1549 1550 /* Use single tx/rx queue pair as default */ 1551 vi->curr_queue_pairs = 1; 1552 vi->max_queue_pairs = max_queue_pairs; 1553 1554 /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ 1555 err = init_vqs(vi); 1556 if (err) 1557 goto free_index; 1558 1559 netif_set_real_num_tx_queues(dev, 1); 1560 netif_set_real_num_rx_queues(dev, 1); 1561 1562 err = register_netdev(dev); 1563 if (err) { 1564 pr_debug("virtio_net: registering device failed\n"); 1565 goto free_vqs; 1566 } 1567 1568 /* Last of all, set up some receive buffers. */ 1569 for (i = 0; i < vi->max_queue_pairs; i++) { 1570 try_fill_recv(&vi->rq[i], GFP_KERNEL); 1571 1572 /* If we didn't even get one input buffer, we're useless. */ 1573 if (vi->rq[i].num == 0) { 1574 free_unused_bufs(vi); 1575 err = -ENOMEM; 1576 goto free_recv_bufs; 1577 } 1578 } 1579 1580 vi->nb.notifier_call = &virtnet_cpu_callback; 1581 err = register_hotcpu_notifier(&vi->nb); 1582 if (err) { 1583 pr_debug("virtio_net: registering cpu notifier failed\n"); 1584 goto free_recv_bufs; 1585 } 1586 1587 /* Assume link up if device can't report link status, 1588 otherwise get link status from config. */ 1589 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { 1590 netif_carrier_off(dev); 1591 schedule_work(&vi->config_work); 1592 } else { 1593 vi->status = VIRTIO_NET_S_LINK_UP; 1594 netif_carrier_on(dev); 1595 } 1596 1597 pr_debug("virtnet: registered device %s with %d RX and TX vq's\n", 1598 dev->name, max_queue_pairs); 1599 1600 return 0; 1601 1602 free_recv_bufs: 1603 free_receive_bufs(vi); 1604 unregister_netdev(dev); 1605 free_vqs: 1606 cancel_delayed_work_sync(&vi->refill); 1607 virtnet_del_vqs(vi); 1608 free_index: 1609 free_percpu(vi->vq_index); 1610 free_stats: 1611 free_percpu(vi->stats); 1612 free: 1613 free_netdev(dev); 1614 return err; 1615 } 1616 1617 static void remove_vq_common(struct virtnet_info *vi) 1618 { 1619 vi->vdev->config->reset(vi->vdev); 1620 1621 /* Free unused buffers in both send and recv, if any. */ 1622 free_unused_bufs(vi); 1623 1624 free_receive_bufs(vi); 1625 1626 virtnet_del_vqs(vi); 1627 } 1628 1629 static void virtnet_remove(struct virtio_device *vdev) 1630 { 1631 struct virtnet_info *vi = vdev->priv; 1632 1633 unregister_hotcpu_notifier(&vi->nb); 1634 1635 /* Prevent config work handler from accessing the device. */ 1636 mutex_lock(&vi->config_lock); 1637 vi->config_enable = false; 1638 mutex_unlock(&vi->config_lock); 1639 1640 unregister_netdev(vi->dev); 1641 1642 remove_vq_common(vi); 1643 1644 flush_work(&vi->config_work); 1645 1646 free_percpu(vi->vq_index); 1647 free_percpu(vi->stats); 1648 free_netdev(vi->dev); 1649 } 1650 1651 #ifdef CONFIG_PM 1652 static int virtnet_freeze(struct virtio_device *vdev) 1653 { 1654 struct virtnet_info *vi = vdev->priv; 1655 int i; 1656 1657 /* Prevent config work handler from accessing the device */ 1658 mutex_lock(&vi->config_lock); 1659 vi->config_enable = false; 1660 mutex_unlock(&vi->config_lock); 1661 1662 netif_device_detach(vi->dev); 1663 cancel_delayed_work_sync(&vi->refill); 1664 1665 if (netif_running(vi->dev)) 1666 for (i = 0; i < vi->max_queue_pairs; i++) { 1667 napi_disable(&vi->rq[i].napi); 1668 netif_napi_del(&vi->rq[i].napi); 1669 } 1670 1671 remove_vq_common(vi); 1672 1673 flush_work(&vi->config_work); 1674 1675 return 0; 1676 } 1677 1678 static int virtnet_restore(struct virtio_device *vdev) 1679 { 1680 struct virtnet_info *vi = vdev->priv; 1681 int err, i; 1682 1683 err = init_vqs(vi); 1684 if (err) 1685 return err; 1686 1687 if (netif_running(vi->dev)) 1688 for (i = 0; i < vi->max_queue_pairs; i++) 1689 virtnet_napi_enable(&vi->rq[i]); 1690 1691 netif_device_attach(vi->dev); 1692 1693 for (i = 0; i < vi->max_queue_pairs; i++) 1694 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) 1695 schedule_delayed_work(&vi->refill, 0); 1696 1697 mutex_lock(&vi->config_lock); 1698 vi->config_enable = true; 1699 mutex_unlock(&vi->config_lock); 1700 1701 virtnet_set_queues(vi, vi->curr_queue_pairs); 1702 1703 return 0; 1704 } 1705 #endif 1706 1707 static struct virtio_device_id id_table[] = { 1708 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 1709 { 0 }, 1710 }; 1711 1712 static unsigned int features[] = { 1713 VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, 1714 VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, 1715 VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, 1716 VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, 1717 VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, 1718 VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, 1719 VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, 1720 VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, 1721 VIRTIO_NET_F_CTRL_MAC_ADDR, 1722 }; 1723 1724 static struct virtio_driver virtio_net_driver = { 1725 .feature_table = features, 1726 .feature_table_size = ARRAY_SIZE(features), 1727 .driver.name = KBUILD_MODNAME, 1728 .driver.owner = THIS_MODULE, 1729 .id_table = id_table, 1730 .probe = virtnet_probe, 1731 .remove = virtnet_remove, 1732 .config_changed = virtnet_config_changed, 1733 #ifdef CONFIG_PM 1734 .freeze = virtnet_freeze, 1735 .restore = virtnet_restore, 1736 #endif 1737 }; 1738 1739 module_virtio_driver(virtio_net_driver); 1740 1741 MODULE_DEVICE_TABLE(virtio, id_table); 1742 MODULE_DESCRIPTION("Virtio network driver"); 1743 MODULE_LICENSE("GPL"); 1744