linux/drivers/net/virtio_net.c
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   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
  30static int napi_weight = 128;
  31module_param(napi_weight, int, 0444);
  32
  33static bool csum = true, gso = true;
  34module_param(csum, bool, 0444);
  35module_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
  44struct 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
  54struct virtnet_info {
  55        struct virtio_device *vdev;
  56        struct virtqueue *rvq, *svq, *cvq;
  57        struct net_device *dev;
  58        struct napi_struct napi;
  59        unsigned int status;
  60
  61        /* Number of input buffers, and max we've ever had. */
  62        unsigned int num, max;
  63
  64        /* I like... big packets and I cannot lie! */
  65        bool big_packets;
  66
  67        /* Host will merge rx buffers for big packets (shake it! shake it!) */
  68        bool mergeable_rx_bufs;
  69
  70        /* enable config space updates */
  71        bool config_enable;
  72
  73        /* Active statistics */
  74        struct virtnet_stats __percpu *stats;
  75
  76        /* Work struct for refilling if we run low on memory. */
  77        struct delayed_work refill;
  78
  79        /* Work struct for config space updates */
  80        struct work_struct config_work;
  81
  82        /* Lock for config space updates */
  83        struct mutex config_lock;
  84
  85        /* Chain pages by the private ptr. */
  86        struct page *pages;
  87
  88        /* fragments + linear part + virtio header */
  89        struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
  90        struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
  91};
  92
  93struct skb_vnet_hdr {
  94        union {
  95                struct virtio_net_hdr hdr;
  96                struct virtio_net_hdr_mrg_rxbuf mhdr;
  97        };
  98        unsigned int num_sg;
  99};
 100
 101struct padded_vnet_hdr {
 102        struct virtio_net_hdr hdr;
 103        /*
 104         * virtio_net_hdr should be in a separated sg buffer because of a
 105         * QEMU bug, and data sg buffer shares same page with this header sg.
 106         * This padding makes next sg 16 byte aligned after virtio_net_hdr.
 107         */
 108        char padding[6];
 109};
 110
 111static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 112{
 113        return (struct skb_vnet_hdr *)skb->cb;
 114}
 115
 116/*
 117 * private is used to chain pages for big packets, put the whole
 118 * most recent used list in the beginning for reuse
 119 */
 120static void give_pages(struct virtnet_info *vi, struct page *page)
 121{
 122        struct page *end;
 123
 124        /* Find end of list, sew whole thing into vi->pages. */
 125        for (end = page; end->private; end = (struct page *)end->private);
 126        end->private = (unsigned long)vi->pages;
 127        vi->pages = page;
 128}
 129
 130static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
 131{
 132        struct page *p = vi->pages;
 133
 134        if (p) {
 135                vi->pages = (struct page *)p->private;
 136                /* clear private here, it is used to chain pages */
 137                p->private = 0;
 138        } else
 139                p = alloc_page(gfp_mask);
 140        return p;
 141}
 142
 143static void skb_xmit_done(struct virtqueue *svq)
 144{
 145        struct virtnet_info *vi = svq->vdev->priv;
 146
 147        /* Suppress further interrupts. */
 148        virtqueue_disable_cb(svq);
 149
 150        /* We were probably waiting for more output buffers. */
 151        netif_wake_queue(vi->dev);
 152}
 153
 154static void set_skb_frag(struct sk_buff *skb, struct page *page,
 155                         unsigned int offset, unsigned int *len)
 156{
 157        int size = min((unsigned)PAGE_SIZE - offset, *len);
 158        int i = skb_shinfo(skb)->nr_frags;
 159
 160        __skb_fill_page_desc(skb, i, page, offset, size);
 161
 162        skb->data_len += size;
 163        skb->len += size;
 164        skb->truesize += PAGE_SIZE;
 165        skb_shinfo(skb)->nr_frags++;
 166        *len -= size;
 167}
 168
 169/* Called from bottom half context */
 170static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 171                                   struct page *page, unsigned int len)
 172{
 173        struct sk_buff *skb;
 174        struct skb_vnet_hdr *hdr;
 175        unsigned int copy, hdr_len, offset;
 176        char *p;
 177
 178        p = page_address(page);
 179
 180        /* copy small packet so we can reuse these pages for small data */
 181        skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 182        if (unlikely(!skb))
 183                return NULL;
 184
 185        hdr = skb_vnet_hdr(skb);
 186
 187        if (vi->mergeable_rx_bufs) {
 188                hdr_len = sizeof hdr->mhdr;
 189                offset = hdr_len;
 190        } else {
 191                hdr_len = sizeof hdr->hdr;
 192                offset = sizeof(struct padded_vnet_hdr);
 193        }
 194
 195        memcpy(hdr, p, hdr_len);
 196
 197        len -= hdr_len;
 198        p += offset;
 199
 200        copy = len;
 201        if (copy > skb_tailroom(skb))
 202                copy = skb_tailroom(skb);
 203        memcpy(skb_put(skb, copy), p, copy);
 204
 205        len -= copy;
 206        offset += copy;
 207
 208        /*
 209         * Verify that we can indeed put this data into a skb.
 210         * This is here to handle cases when the device erroneously
 211         * tries to receive more than is possible. This is usually
 212         * the case of a broken device.
 213         */
 214        if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 215                if (net_ratelimit())
 216                        pr_debug("%s: too much data\n", skb->dev->name);
 217                dev_kfree_skb(skb);
 218                return NULL;
 219        }
 220
 221        while (len) {
 222                set_skb_frag(skb, page, offset, &len);
 223                page = (struct page *)page->private;
 224                offset = 0;
 225        }
 226
 227        if (page)
 228                give_pages(vi, page);
 229
 230        return skb;
 231}
 232
 233static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
 234{
 235        struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 236        struct page *page;
 237        int num_buf, i, len;
 238
 239        num_buf = hdr->mhdr.num_buffers;
 240        while (--num_buf) {
 241                i = skb_shinfo(skb)->nr_frags;
 242                if (i >= MAX_SKB_FRAGS) {
 243                        pr_debug("%s: packet too long\n", skb->dev->name);
 244                        skb->dev->stats.rx_length_errors++;
 245                        return -EINVAL;
 246                }
 247                page = virtqueue_get_buf(vi->rvq, &len);
 248                if (!page) {
 249                        pr_debug("%s: rx error: %d buffers missing\n",
 250                                 skb->dev->name, hdr->mhdr.num_buffers);
 251                        skb->dev->stats.rx_length_errors++;
 252                        return -EINVAL;
 253                }
 254
 255                if (len > PAGE_SIZE)
 256                        len = PAGE_SIZE;
 257
 258                set_skb_frag(skb, page, 0, &len);
 259
 260                --vi->num;
 261        }
 262        return 0;
 263}
 264
 265static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
 266{
 267        struct virtnet_info *vi = netdev_priv(dev);
 268        struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 269        struct sk_buff *skb;
 270        struct page *page;
 271        struct skb_vnet_hdr *hdr;
 272
 273        if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 274                pr_debug("%s: short packet %i\n", dev->name, len);
 275                dev->stats.rx_length_errors++;
 276                if (vi->mergeable_rx_bufs || vi->big_packets)
 277                        give_pages(vi, buf);
 278                else
 279                        dev_kfree_skb(buf);
 280                return;
 281        }
 282
 283        if (!vi->mergeable_rx_bufs && !vi->big_packets) {
 284                skb = buf;
 285                len -= sizeof(struct virtio_net_hdr);
 286                skb_trim(skb, len);
 287        } else {
 288                page = buf;
 289                skb = page_to_skb(vi, page, len);
 290                if (unlikely(!skb)) {
 291                        dev->stats.rx_dropped++;
 292                        give_pages(vi, page);
 293                        return;
 294                }
 295                if (vi->mergeable_rx_bufs)
 296                        if (receive_mergeable(vi, skb)) {
 297                                dev_kfree_skb(skb);
 298                                return;
 299                        }
 300        }
 301
 302        hdr = skb_vnet_hdr(skb);
 303
 304        u64_stats_update_begin(&stats->rx_syncp);
 305        stats->rx_bytes += skb->len;
 306        stats->rx_packets++;
 307        u64_stats_update_end(&stats->rx_syncp);
 308
 309        if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 310                pr_debug("Needs csum!\n");
 311                if (!skb_partial_csum_set(skb,
 312                                          hdr->hdr.csum_start,
 313                                          hdr->hdr.csum_offset))
 314                        goto frame_err;
 315        } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 316                skb->ip_summed = CHECKSUM_UNNECESSARY;
 317        }
 318
 319        skb->protocol = eth_type_trans(skb, dev);
 320        pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 321                 ntohs(skb->protocol), skb->len, skb->pkt_type);
 322
 323        if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 324                pr_debug("GSO!\n");
 325                switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 326                case VIRTIO_NET_HDR_GSO_TCPV4:
 327                        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 328                        break;
 329                case VIRTIO_NET_HDR_GSO_UDP:
 330                        skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 331                        break;
 332                case VIRTIO_NET_HDR_GSO_TCPV6:
 333                        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 334                        break;
 335                default:
 336                        if (net_ratelimit())
 337                                printk(KERN_WARNING "%s: bad gso type %u.\n",
 338                                       dev->name, hdr->hdr.gso_type);
 339                        goto frame_err;
 340                }
 341
 342                if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 343                        skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 344
 345                skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 346                if (skb_shinfo(skb)->gso_size == 0) {
 347                        if (net_ratelimit())
 348                                printk(KERN_WARNING "%s: zero gso size.\n",
 349                                       dev->name);
 350                        goto frame_err;
 351                }
 352
 353                /* Header must be checked, and gso_segs computed. */
 354                skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 355                skb_shinfo(skb)->gso_segs = 0;
 356        }
 357
 358        netif_receive_skb(skb);
 359        return;
 360
 361frame_err:
 362        dev->stats.rx_frame_errors++;
 363        dev_kfree_skb(skb);
 364}
 365
 366static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
 367{
 368        struct sk_buff *skb;
 369        struct skb_vnet_hdr *hdr;
 370        int err;
 371
 372        skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
 373        if (unlikely(!skb))
 374                return -ENOMEM;
 375
 376        skb_put(skb, MAX_PACKET_LEN);
 377
 378        hdr = skb_vnet_hdr(skb);
 379        sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr);
 380
 381        skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
 382
 383        err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 2, skb, gfp);
 384        if (err < 0)
 385                dev_kfree_skb(skb);
 386
 387        return err;
 388}
 389
 390static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
 391{
 392        struct page *first, *list = NULL;
 393        char *p;
 394        int i, err, offset;
 395
 396        /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
 397        for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 398                first = get_a_page(vi, gfp);
 399                if (!first) {
 400                        if (list)
 401                                give_pages(vi, list);
 402                        return -ENOMEM;
 403                }
 404                sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE);
 405
 406                /* chain new page in list head to match sg */
 407                first->private = (unsigned long)list;
 408                list = first;
 409        }
 410
 411        first = get_a_page(vi, gfp);
 412        if (!first) {
 413                give_pages(vi, list);
 414                return -ENOMEM;
 415        }
 416        p = page_address(first);
 417
 418        /* vi->rx_sg[0], vi->rx_sg[1] share the same page */
 419        /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
 420        sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr));
 421
 422        /* vi->rx_sg[1] for data packet, from offset */
 423        offset = sizeof(struct padded_vnet_hdr);
 424        sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset);
 425
 426        /* chain first in list head */
 427        first->private = (unsigned long)list;
 428        err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
 429                                first, gfp);
 430        if (err < 0)
 431                give_pages(vi, first);
 432
 433        return err;
 434}
 435
 436static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
 437{
 438        struct page *page;
 439        int err;
 440
 441        page = get_a_page(vi, gfp);
 442        if (!page)
 443                return -ENOMEM;
 444
 445        sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE);
 446
 447        err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 1, page, gfp);
 448        if (err < 0)
 449                give_pages(vi, page);
 450
 451        return err;
 452}
 453
 454/*
 455 * Returns false if we couldn't fill entirely (OOM).
 456 *
 457 * Normally run in the receive path, but can also be run from ndo_open
 458 * before we're receiving packets, or from refill_work which is
 459 * careful to disable receiving (using napi_disable).
 460 */
 461static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
 462{
 463        int err;
 464        bool oom;
 465
 466        do {
 467                if (vi->mergeable_rx_bufs)
 468                        err = add_recvbuf_mergeable(vi, gfp);
 469                else if (vi->big_packets)
 470                        err = add_recvbuf_big(vi, gfp);
 471                else
 472                        err = add_recvbuf_small(vi, gfp);
 473
 474                oom = err == -ENOMEM;
 475                if (err < 0)
 476                        break;
 477                ++vi->num;
 478        } while (err > 0);
 479        if (unlikely(vi->num > vi->max))
 480                vi->max = vi->num;
 481        virtqueue_kick(vi->rvq);
 482        return !oom;
 483}
 484
 485static void skb_recv_done(struct virtqueue *rvq)
 486{
 487        struct virtnet_info *vi = rvq->vdev->priv;
 488        /* Schedule NAPI, Suppress further interrupts if successful. */
 489        if (napi_schedule_prep(&vi->napi)) {
 490                virtqueue_disable_cb(rvq);
 491                __napi_schedule(&vi->napi);
 492        }
 493}
 494
 495static void virtnet_napi_enable(struct virtnet_info *vi)
 496{
 497        napi_enable(&vi->napi);
 498
 499        /* If all buffers were filled by other side before we napi_enabled, we
 500         * won't get another interrupt, so process any outstanding packets
 501         * now.  virtnet_poll wants re-enable the queue, so we disable here.
 502         * We synchronize against interrupts via NAPI_STATE_SCHED */
 503        if (napi_schedule_prep(&vi->napi)) {
 504                virtqueue_disable_cb(vi->rvq);
 505                local_bh_disable();
 506                __napi_schedule(&vi->napi);
 507                local_bh_enable();
 508        }
 509}
 510
 511static void refill_work(struct work_struct *work)
 512{
 513        struct virtnet_info *vi;
 514        bool still_empty;
 515
 516        vi = container_of(work, struct virtnet_info, refill.work);
 517        napi_disable(&vi->napi);
 518        still_empty = !try_fill_recv(vi, GFP_KERNEL);
 519        virtnet_napi_enable(vi);
 520
 521        /* In theory, this can happen: if we don't get any buffers in
 522         * we will *never* try to fill again. */
 523        if (still_empty)
 524                schedule_delayed_work(&vi->refill, HZ/2);
 525}
 526
 527static int virtnet_poll(struct napi_struct *napi, int budget)
 528{
 529        struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
 530        void *buf;
 531        unsigned int len, received = 0;
 532
 533again:
 534        while (received < budget &&
 535               (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) {
 536                receive_buf(vi->dev, buf, len);
 537                --vi->num;
 538                received++;
 539        }
 540
 541        if (vi->num < vi->max / 2) {
 542                if (!try_fill_recv(vi, GFP_ATOMIC))
 543                        schedule_delayed_work(&vi->refill, 0);
 544        }
 545
 546        /* Out of packets? */
 547        if (received < budget) {
 548                napi_complete(napi);
 549                if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
 550                    napi_schedule_prep(napi)) {
 551                        virtqueue_disable_cb(vi->rvq);
 552                        __napi_schedule(napi);
 553                        goto again;
 554                }
 555        }
 556
 557        return received;
 558}
 559
 560static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
 561{
 562        struct sk_buff *skb;
 563        unsigned int len, tot_sgs = 0;
 564        struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 565
 566        while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
 567                pr_debug("Sent skb %p\n", skb);
 568
 569                u64_stats_update_begin(&stats->tx_syncp);
 570                stats->tx_bytes += skb->len;
 571                stats->tx_packets++;
 572                u64_stats_update_end(&stats->tx_syncp);
 573
 574                tot_sgs += skb_vnet_hdr(skb)->num_sg;
 575                dev_kfree_skb_any(skb);
 576        }
 577        return tot_sgs;
 578}
 579
 580static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
 581{
 582        struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 583        const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 584
 585        pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 586
 587        if (skb->ip_summed == CHECKSUM_PARTIAL) {
 588                hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 589                hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 590                hdr->hdr.csum_offset = skb->csum_offset;
 591        } else {
 592                hdr->hdr.flags = 0;
 593                hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 594        }
 595
 596        if (skb_is_gso(skb)) {
 597                hdr->hdr.hdr_len = skb_headlen(skb);
 598                hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 599                if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 600                        hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 601                else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 602                        hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 603                else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 604                        hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 605                else
 606                        BUG();
 607                if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 608                        hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 609        } else {
 610                hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 611                hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 612        }
 613
 614        hdr->mhdr.num_buffers = 0;
 615
 616        /* Encode metadata header at front. */
 617        if (vi->mergeable_rx_bufs)
 618                sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
 619        else
 620                sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
 621
 622        hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
 623        return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg,
 624                                 0, skb, GFP_ATOMIC);
 625}
 626
 627static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 628{
 629        struct virtnet_info *vi = netdev_priv(dev);
 630        int capacity;
 631
 632        /* Free up any pending old buffers before queueing new ones. */
 633        free_old_xmit_skbs(vi);
 634
 635        /* Try to transmit */
 636        capacity = xmit_skb(vi, skb);
 637
 638        /* This can happen with OOM and indirect buffers. */
 639        if (unlikely(capacity < 0)) {
 640                if (likely(capacity == -ENOMEM)) {
 641                        if (net_ratelimit())
 642                                dev_warn(&dev->dev,
 643                                         "TX queue failure: out of memory\n");
 644                } else {
 645                        dev->stats.tx_fifo_errors++;
 646                        if (net_ratelimit())
 647                                dev_warn(&dev->dev,
 648                                         "Unexpected TX queue failure: %d\n",
 649                                         capacity);
 650                }
 651                dev->stats.tx_dropped++;
 652                kfree_skb(skb);
 653                return NETDEV_TX_OK;
 654        }
 655        virtqueue_kick(vi->svq);
 656
 657        /* Don't wait up for transmitted skbs to be freed. */
 658        skb_orphan(skb);
 659        nf_reset(skb);
 660
 661        /* Apparently nice girls don't return TX_BUSY; stop the queue
 662         * before it gets out of hand.  Naturally, this wastes entries. */
 663        if (capacity < 2+MAX_SKB_FRAGS) {
 664                netif_stop_queue(dev);
 665                if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
 666                        /* More just got used, free them then recheck. */
 667                        capacity += free_old_xmit_skbs(vi);
 668                        if (capacity >= 2+MAX_SKB_FRAGS) {
 669                                netif_start_queue(dev);
 670                                virtqueue_disable_cb(vi->svq);
 671                        }
 672                }
 673        }
 674
 675        return NETDEV_TX_OK;
 676}
 677
 678static int virtnet_set_mac_address(struct net_device *dev, void *p)
 679{
 680        struct virtnet_info *vi = netdev_priv(dev);
 681        struct virtio_device *vdev = vi->vdev;
 682        int ret;
 683
 684        ret = eth_mac_addr(dev, p);
 685        if (ret)
 686                return ret;
 687
 688        if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 689                vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
 690                                  dev->dev_addr, dev->addr_len);
 691
 692        return 0;
 693}
 694
 695static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
 696                                               struct rtnl_link_stats64 *tot)
 697{
 698        struct virtnet_info *vi = netdev_priv(dev);
 699        int cpu;
 700        unsigned int start;
 701
 702        for_each_possible_cpu(cpu) {
 703                struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
 704                u64 tpackets, tbytes, rpackets, rbytes;
 705
 706                do {
 707                        start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
 708                        tpackets = stats->tx_packets;
 709                        tbytes   = stats->tx_bytes;
 710                } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
 711
 712                do {
 713                        start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
 714                        rpackets = stats->rx_packets;
 715                        rbytes   = stats->rx_bytes;
 716                } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
 717
 718                tot->rx_packets += rpackets;
 719                tot->tx_packets += tpackets;
 720                tot->rx_bytes   += rbytes;
 721                tot->tx_bytes   += tbytes;
 722        }
 723
 724        tot->tx_dropped = dev->stats.tx_dropped;
 725        tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 726        tot->rx_dropped = dev->stats.rx_dropped;
 727        tot->rx_length_errors = dev->stats.rx_length_errors;
 728        tot->rx_frame_errors = dev->stats.rx_frame_errors;
 729
 730        return tot;
 731}
 732
 733#ifdef CONFIG_NET_POLL_CONTROLLER
 734static void virtnet_netpoll(struct net_device *dev)
 735{
 736        struct virtnet_info *vi = netdev_priv(dev);
 737
 738        napi_schedule(&vi->napi);
 739}
 740#endif
 741
 742static int virtnet_open(struct net_device *dev)
 743{
 744        struct virtnet_info *vi = netdev_priv(dev);
 745
 746        /* Make sure we have some buffers: if oom use wq. */
 747        if (!try_fill_recv(vi, GFP_KERNEL))
 748                schedule_delayed_work(&vi->refill, 0);
 749
 750        virtnet_napi_enable(vi);
 751        return 0;
 752}
 753
 754/*
 755 * Send command via the control virtqueue and check status.  Commands
 756 * supported by the hypervisor, as indicated by feature bits, should
 757 * never fail unless improperly formated.
 758 */
 759static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 760                                 struct scatterlist *data, int out, int in)
 761{
 762        struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
 763        struct virtio_net_ctrl_hdr ctrl;
 764        virtio_net_ctrl_ack status = ~0;
 765        unsigned int tmp;
 766        int i;
 767
 768        /* Caller should know better */
 769        BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
 770                (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
 771
 772        out++; /* Add header */
 773        in++; /* Add return status */
 774
 775        ctrl.class = class;
 776        ctrl.cmd = cmd;
 777
 778        sg_init_table(sg, out + in);
 779
 780        sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
 781        for_each_sg(data, s, out + in - 2, i)
 782                sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
 783        sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
 784
 785        BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
 786
 787        virtqueue_kick(vi->cvq);
 788
 789        /*
 790         * Spin for a response, the kick causes an ioport write, trapping
 791         * into the hypervisor, so the request should be handled immediately.
 792         */
 793        while (!virtqueue_get_buf(vi->cvq, &tmp))
 794                cpu_relax();
 795
 796        return status == VIRTIO_NET_OK;
 797}
 798
 799static void virtnet_ack_link_announce(struct virtnet_info *vi)
 800{
 801        rtnl_lock();
 802        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
 803                                  VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
 804                                  0, 0))
 805                dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
 806        rtnl_unlock();
 807}
 808
 809static int virtnet_close(struct net_device *dev)
 810{
 811        struct virtnet_info *vi = netdev_priv(dev);
 812
 813        /* Make sure refill_work doesn't re-enable napi! */
 814        cancel_delayed_work_sync(&vi->refill);
 815        napi_disable(&vi->napi);
 816
 817        return 0;
 818}
 819
 820static void virtnet_set_rx_mode(struct net_device *dev)
 821{
 822        struct virtnet_info *vi = netdev_priv(dev);
 823        struct scatterlist sg[2];
 824        u8 promisc, allmulti;
 825        struct virtio_net_ctrl_mac *mac_data;
 826        struct netdev_hw_addr *ha;
 827        int uc_count;
 828        int mc_count;
 829        void *buf;
 830        int i;
 831
 832        /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
 833        if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
 834                return;
 835
 836        promisc = ((dev->flags & IFF_PROMISC) != 0);
 837        allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
 838
 839        sg_init_one(sg, &promisc, sizeof(promisc));
 840
 841        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 842                                  VIRTIO_NET_CTRL_RX_PROMISC,
 843                                  sg, 1, 0))
 844                dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
 845                         promisc ? "en" : "dis");
 846
 847        sg_init_one(sg, &allmulti, sizeof(allmulti));
 848
 849        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 850                                  VIRTIO_NET_CTRL_RX_ALLMULTI,
 851                                  sg, 1, 0))
 852                dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
 853                         allmulti ? "en" : "dis");
 854
 855        uc_count = netdev_uc_count(dev);
 856        mc_count = netdev_mc_count(dev);
 857        /* MAC filter - use one buffer for both lists */
 858        buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
 859                      (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
 860        mac_data = buf;
 861        if (!buf) {
 862                dev_warn(&dev->dev, "No memory for MAC address buffer\n");
 863                return;
 864        }
 865
 866        sg_init_table(sg, 2);
 867
 868        /* Store the unicast list and count in the front of the buffer */
 869        mac_data->entries = uc_count;
 870        i = 0;
 871        netdev_for_each_uc_addr(ha, dev)
 872                memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 873
 874        sg_set_buf(&sg[0], mac_data,
 875                   sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
 876
 877        /* multicast list and count fill the end */
 878        mac_data = (void *)&mac_data->macs[uc_count][0];
 879
 880        mac_data->entries = mc_count;
 881        i = 0;
 882        netdev_for_each_mc_addr(ha, dev)
 883                memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 884
 885        sg_set_buf(&sg[1], mac_data,
 886                   sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
 887
 888        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 889                                  VIRTIO_NET_CTRL_MAC_TABLE_SET,
 890                                  sg, 2, 0))
 891                dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
 892
 893        kfree(buf);
 894}
 895
 896static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
 897{
 898        struct virtnet_info *vi = netdev_priv(dev);
 899        struct scatterlist sg;
 900
 901        sg_init_one(&sg, &vid, sizeof(vid));
 902
 903        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 904                                  VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
 905                dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
 906        return 0;
 907}
 908
 909static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
 910{
 911        struct virtnet_info *vi = netdev_priv(dev);
 912        struct scatterlist sg;
 913
 914        sg_init_one(&sg, &vid, sizeof(vid));
 915
 916        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 917                                  VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
 918                dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
 919        return 0;
 920}
 921
 922static void virtnet_get_ringparam(struct net_device *dev,
 923                                struct ethtool_ringparam *ring)
 924{
 925        struct virtnet_info *vi = netdev_priv(dev);
 926
 927        ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq);
 928        ring->tx_max_pending = virtqueue_get_vring_size(vi->svq);
 929        ring->rx_pending = ring->rx_max_pending;
 930        ring->tx_pending = ring->tx_max_pending;
 931
 932}
 933
 934
 935static void virtnet_get_drvinfo(struct net_device *dev,
 936                                struct ethtool_drvinfo *info)
 937{
 938        struct virtnet_info *vi = netdev_priv(dev);
 939        struct virtio_device *vdev = vi->vdev;
 940
 941        strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
 942        strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
 943        strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
 944
 945}
 946
 947static const struct ethtool_ops virtnet_ethtool_ops = {
 948        .get_drvinfo = virtnet_get_drvinfo,
 949        .get_link = ethtool_op_get_link,
 950        .get_ringparam = virtnet_get_ringparam,
 951};
 952
 953#define MIN_MTU 68
 954#define MAX_MTU 65535
 955
 956static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
 957{
 958        if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
 959                return -EINVAL;
 960        dev->mtu = new_mtu;
 961        return 0;
 962}
 963
 964static const struct net_device_ops virtnet_netdev = {
 965        .ndo_open            = virtnet_open,
 966        .ndo_stop            = virtnet_close,
 967        .ndo_start_xmit      = start_xmit,
 968        .ndo_validate_addr   = eth_validate_addr,
 969        .ndo_set_mac_address = virtnet_set_mac_address,
 970        .ndo_set_rx_mode     = virtnet_set_rx_mode,
 971        .ndo_change_mtu      = virtnet_change_mtu,
 972        .ndo_get_stats64     = virtnet_stats,
 973        .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
 974        .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
 975#ifdef CONFIG_NET_POLL_CONTROLLER
 976        .ndo_poll_controller = virtnet_netpoll,
 977#endif
 978};
 979
 980static void virtnet_config_changed_work(struct work_struct *work)
 981{
 982        struct virtnet_info *vi =
 983                container_of(work, struct virtnet_info, config_work);
 984        u16 v;
 985
 986        mutex_lock(&vi->config_lock);
 987        if (!vi->config_enable)
 988                goto done;
 989
 990        if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
 991                              offsetof(struct virtio_net_config, status),
 992                              &v) < 0)
 993                goto done;
 994
 995        if (v & VIRTIO_NET_S_ANNOUNCE) {
 996                netdev_notify_peers(vi->dev);
 997                virtnet_ack_link_announce(vi);
 998        }
 999
1000        /* Ignore unknown (future) status bits */
1001        v &= VIRTIO_NET_S_LINK_UP;
1002
1003        if (vi->status == v)
1004                goto done;
1005
1006        vi->status = v;
1007
1008        if (vi->status & VIRTIO_NET_S_LINK_UP) {
1009                netif_carrier_on(vi->dev);
1010                netif_wake_queue(vi->dev);
1011        } else {
1012                netif_carrier_off(vi->dev);
1013                netif_stop_queue(vi->dev);
1014        }
1015done:
1016        mutex_unlock(&vi->config_lock);
1017}
1018
1019static void virtnet_config_changed(struct virtio_device *vdev)
1020{
1021        struct virtnet_info *vi = vdev->priv;
1022
1023        schedule_work(&vi->config_work);
1024}
1025
1026static int init_vqs(struct virtnet_info *vi)
1027{
1028        struct virtqueue *vqs[3];
1029        vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
1030        const char *names[] = { "input", "output", "control" };
1031        int nvqs, err;
1032
1033        /* We expect two virtqueues, receive then send,
1034         * and optionally control. */
1035        nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
1036
1037        err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names);
1038        if (err)
1039                return err;
1040
1041        vi->rvq = vqs[0];
1042        vi->svq = vqs[1];
1043
1044        if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
1045                vi->cvq = vqs[2];
1046
1047                if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1048                        vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1049        }
1050        return 0;
1051}
1052
1053static int virtnet_probe(struct virtio_device *vdev)
1054{
1055        int err;
1056        struct net_device *dev;
1057        struct virtnet_info *vi;
1058
1059        /* Allocate ourselves a network device with room for our info */
1060        dev = alloc_etherdev(sizeof(struct virtnet_info));
1061        if (!dev)
1062                return -ENOMEM;
1063
1064        /* Set up network device as normal. */
1065        dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1066        dev->netdev_ops = &virtnet_netdev;
1067        dev->features = NETIF_F_HIGHDMA;
1068
1069        SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1070        SET_NETDEV_DEV(dev, &vdev->dev);
1071
1072        /* Do we support "hardware" checksums? */
1073        if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1074                /* This opens up the world of extra features. */
1075                dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1076                if (csum)
1077                        dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1078
1079                if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1080                        dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1081                                | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1082                }
1083                /* Individual feature bits: what can host handle? */
1084                if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1085                        dev->hw_features |= NETIF_F_TSO;
1086                if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1087                        dev->hw_features |= NETIF_F_TSO6;
1088                if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1089                        dev->hw_features |= NETIF_F_TSO_ECN;
1090                if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1091                        dev->hw_features |= NETIF_F_UFO;
1092
1093                if (gso)
1094                        dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1095                /* (!csum && gso) case will be fixed by register_netdev() */
1096        }
1097
1098        /* Configuration may specify what MAC to use.  Otherwise random. */
1099        if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1100                                  offsetof(struct virtio_net_config, mac),
1101                                  dev->dev_addr, dev->addr_len) < 0)
1102                eth_hw_addr_random(dev);
1103
1104        /* Set up our device-specific information */
1105        vi = netdev_priv(dev);
1106        netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
1107        vi->dev = dev;
1108        vi->vdev = vdev;
1109        vdev->priv = vi;
1110        vi->pages = NULL;
1111        vi->stats = alloc_percpu(struct virtnet_stats);
1112        err = -ENOMEM;
1113        if (vi->stats == NULL)
1114                goto free;
1115
1116        INIT_DELAYED_WORK(&vi->refill, refill_work);
1117        mutex_init(&vi->config_lock);
1118        vi->config_enable = true;
1119        INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1120        sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
1121        sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
1122
1123        /* If we can receive ANY GSO packets, we must allocate large ones. */
1124        if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1125            virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1126            virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1127                vi->big_packets = true;
1128
1129        if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1130                vi->mergeable_rx_bufs = true;
1131
1132        err = init_vqs(vi);
1133        if (err)
1134                goto free_stats;
1135
1136        err = register_netdev(dev);
1137        if (err) {
1138                pr_debug("virtio_net: registering device failed\n");
1139                goto free_vqs;
1140        }
1141
1142        /* Last of all, set up some receive buffers. */
1143        try_fill_recv(vi, GFP_KERNEL);
1144
1145        /* If we didn't even get one input buffer, we're useless. */
1146        if (vi->num == 0) {
1147                err = -ENOMEM;
1148                goto unregister;
1149        }
1150
1151        /* Assume link up if device can't report link status,
1152           otherwise get link status from config. */
1153        if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1154                netif_carrier_off(dev);
1155                schedule_work(&vi->config_work);
1156        } else {
1157                vi->status = VIRTIO_NET_S_LINK_UP;
1158                netif_carrier_on(dev);
1159        }
1160
1161        pr_debug("virtnet: registered device %s\n", dev->name);
1162        return 0;
1163
1164unregister:
1165        unregister_netdev(dev);
1166free_vqs:
1167        vdev->config->del_vqs(vdev);
1168free_stats:
1169        free_percpu(vi->stats);
1170free:
1171        free_netdev(dev);
1172        return err;
1173}
1174
1175static void free_unused_bufs(struct virtnet_info *vi)
1176{
1177        void *buf;
1178        while (1) {
1179                buf = virtqueue_detach_unused_buf(vi->svq);
1180                if (!buf)
1181                        break;
1182                dev_kfree_skb(buf);
1183        }
1184        while (1) {
1185                buf = virtqueue_detach_unused_buf(vi->rvq);
1186                if (!buf)
1187                        break;
1188                if (vi->mergeable_rx_bufs || vi->big_packets)
1189                        give_pages(vi, buf);
1190                else
1191                        dev_kfree_skb(buf);
1192                --vi->num;
1193        }
1194        BUG_ON(vi->num != 0);
1195}
1196
1197static void remove_vq_common(struct virtnet_info *vi)
1198{
1199        vi->vdev->config->reset(vi->vdev);
1200
1201        /* Free unused buffers in both send and recv, if any. */
1202        free_unused_bufs(vi);
1203
1204        vi->vdev->config->del_vqs(vi->vdev);
1205
1206        while (vi->pages)
1207                __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1208}
1209
1210static void __devexit virtnet_remove(struct virtio_device *vdev)
1211{
1212        struct virtnet_info *vi = vdev->priv;
1213
1214        /* Prevent config work handler from accessing the device. */
1215        mutex_lock(&vi->config_lock);
1216        vi->config_enable = false;
1217        mutex_unlock(&vi->config_lock);
1218
1219        unregister_netdev(vi->dev);
1220
1221        remove_vq_common(vi);
1222
1223        flush_work(&vi->config_work);
1224
1225        free_percpu(vi->stats);
1226        free_netdev(vi->dev);
1227}
1228
1229#ifdef CONFIG_PM
1230static int virtnet_freeze(struct virtio_device *vdev)
1231{
1232        struct virtnet_info *vi = vdev->priv;
1233
1234        /* Prevent config work handler from accessing the device */
1235        mutex_lock(&vi->config_lock);
1236        vi->config_enable = false;
1237        mutex_unlock(&vi->config_lock);
1238
1239        netif_device_detach(vi->dev);
1240        cancel_delayed_work_sync(&vi->refill);
1241
1242        if (netif_running(vi->dev))
1243                napi_disable(&vi->napi);
1244
1245        remove_vq_common(vi);
1246
1247        flush_work(&vi->config_work);
1248
1249        return 0;
1250}
1251
1252static int virtnet_restore(struct virtio_device *vdev)
1253{
1254        struct virtnet_info *vi = vdev->priv;
1255        int err;
1256
1257        err = init_vqs(vi);
1258        if (err)
1259                return err;
1260
1261        if (netif_running(vi->dev))
1262                virtnet_napi_enable(vi);
1263
1264        netif_device_attach(vi->dev);
1265
1266        if (!try_fill_recv(vi, GFP_KERNEL))
1267                schedule_delayed_work(&vi->refill, 0);
1268
1269        mutex_lock(&vi->config_lock);
1270        vi->config_enable = true;
1271        mutex_unlock(&vi->config_lock);
1272
1273        return 0;
1274}
1275#endif
1276
1277static struct virtio_device_id id_table[] = {
1278        { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1279        { 0 },
1280};
1281
1282static unsigned int features[] = {
1283        VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1284        VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1285        VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1286        VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1287        VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1288        VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1289        VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1290        VIRTIO_NET_F_GUEST_ANNOUNCE,
1291};
1292
1293static struct virtio_driver virtio_net_driver = {
1294        .feature_table = features,
1295        .feature_table_size = ARRAY_SIZE(features),
1296        .driver.name =  KBUILD_MODNAME,
1297        .driver.owner = THIS_MODULE,
1298        .id_table =     id_table,
1299        .probe =        virtnet_probe,
1300        .remove =       __devexit_p(virtnet_remove),
1301        .config_changed = virtnet_config_changed,
1302#ifdef CONFIG_PM
1303        .freeze =       virtnet_freeze,
1304        .restore =      virtnet_restore,
1305#endif
1306};
1307
1308static int __init init(void)
1309{
1310        return register_virtio_driver(&virtio_net_driver);
1311}
1312
1313static void __exit fini(void)
1314{
1315        unregister_virtio_driver(&virtio_net_driver);
1316}
1317module_init(init);
1318module_exit(fini);
1319
1320MODULE_DEVICE_TABLE(virtio, id_table);
1321MODULE_DESCRIPTION("Virtio network driver");
1322MODULE_LICENSE("GPL");
1323
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