drivers/net/virtio_net.c

   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, see <http://www.gnu.org/licenses/>.
  17  */
  18 //#define DEBUG
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/ethtool.h>
  22 #include <linux/module.h>
  23 #include <linux/virtio.h>
  24 #include <linux/virtio_net.h>
  25 #include <linux/bpf.h>
  26 #include <linux/scatterlist.h>
  27 #include <linux/if_vlan.h>
  28 #include <linux/slab.h>
  29 #include <linux/cpu.h>
  30 #include <linux/average.h>
  31 #include <net/busy_poll.h>
  32
  33 static int napi_weight = NAPI_POLL_WEIGHT;
  34 module_param(napi_weight, int, 0444);
  35
  36 static bool csum = true, gso = true;
  37 module_param(csum, bool, 0444);
  38 module_param(gso, bool, 0444);
  39
  40 /* FIXME: MTU in config. */
  41 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  42 #define GOOD_COPY_LEN   128
  43
  44 /* RX packet size EWMA. The average packet size is used to determine the packet
  45  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  46  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  47  * term, transient changes in packet size.
  48  */
  49 DECLARE_EWMA(pkt_len, 1, 64)
  50
  51 /* Minimum alignment for mergeable packet buffers. */
  52 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
  53
  54 #define VIRTNET_DRIVER_VERSION "1.0.0"
  55
  56 struct virtnet_stats {
  57         struct u64_stats_sync tx_syncp;
  58         struct u64_stats_sync rx_syncp;
  59         u64 tx_bytes;
  60         u64 tx_packets;
  61
  62         u64 rx_bytes;
  63         u64 rx_packets;
  64 };
  65
  66 /* Internal representation of a send virtqueue */
  67 struct send_queue {
  68         /* Virtqueue associated with this send _queue */
  69         struct virtqueue *vq;
  70
  71         /* TX: fragments + linear part + virtio header */
  72         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  73
  74         /* Name of the send queue: output.$index */
  75         char name[40];
  76 };
  77
  78 /* Internal representation of a receive virtqueue */
  79 struct receive_queue {
  80         /* Virtqueue associated with this receive_queue */
  81         struct virtqueue *vq;
  82
  83         struct napi_struct napi;
  84
  85         struct bpf_prog __rcu *xdp_prog;
  86
  87         /* Chain pages by the private ptr. */
  88         struct page *pages;
  89
  90         /* Average packet length for mergeable receive buffers. */
  91         struct ewma_pkt_len mrg_avg_pkt_len;
  92
  93         /* Page frag for packet buffer allocation. */
  94         struct page_frag alloc_frag;
  95
  96         /* RX: fragments + linear part + virtio header */
  97         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  98
  99         /* Name of this receive queue: input.$index */
 100         char name[40];
 101 };
 102
 103 struct virtnet_info {
 104         struct virtio_device *vdev;
 105         struct virtqueue *cvq;
 106         struct net_device *dev;
 107         struct send_queue *sq;
 108         struct receive_queue *rq;
 109         unsigned int status;
 110
 111         /* Max # of queue pairs supported by the device */
 112         u16 max_queue_pairs;
 113
 114         /* # of queue pairs currently used by the driver */
 115         u16 curr_queue_pairs;
 116
 117         /* # of XDP queue pairs currently used by the driver */
 118         u16 xdp_queue_pairs;
 119
 120         /* I like... big packets and I cannot lie! */
 121         bool big_packets;
 122
 123         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 124         bool mergeable_rx_bufs;
 125
 126         /* Has control virtqueue */
 127         bool has_cvq;
 128
 129         /* Host can handle any s/g split between our header and packet data */
 130         bool any_header_sg;
 131
 132         /* Packet virtio header size */
 133         u8 hdr_len;
 134
 135         /* Active statistics */
 136         struct virtnet_stats __percpu *stats;
 137
 138         /* Work struct for refilling if we run low on memory. */
 139         struct delayed_work refill;
 140
 141         /* Work struct for config space updates */
 142         struct work_struct config_work;
 143
 144         /* Does the affinity hint is set for virtqueues? */
 145         bool affinity_hint_set;
 146
 147         /* CPU hotplug instances for online & dead */
 148         struct hlist_node node;
 149         struct hlist_node node_dead;
 150
 151         /* Control VQ buffers: protected by the rtnl lock */
 152         struct virtio_net_ctrl_hdr ctrl_hdr;
 153         virtio_net_ctrl_ack ctrl_status;
 154         struct virtio_net_ctrl_mq ctrl_mq;
 155         u8 ctrl_promisc;
 156         u8 ctrl_allmulti;
 157         u16 ctrl_vid;
 158
 159         /* Ethtool settings */
 160         u8 duplex;
 161         u32 speed;
 162 };
 163
 164 struct padded_vnet_hdr {
 165         struct virtio_net_hdr_mrg_rxbuf hdr;
 166         /*
 167          * hdr is in a separate sg buffer, and data sg buffer shares same page
 168          * with this header sg. This padding makes next sg 16 byte aligned
 169          * after the header.
 170          */
 171         char padding[4];
 172 };
 173
 174 /* Converting between virtqueue no. and kernel tx/rx queue no.
 175  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 176  */
 177 static int vq2txq(struct virtqueue *vq)
 178 {
 179         return (vq->index - 1) / 2;
 180 }
 181
 182 static int txq2vq(int txq)
 183 {
 184         return txq * 2 + 1;
 185 }
 186
 187 static int vq2rxq(struct virtqueue *vq)
 188 {
 189         return vq->index / 2;
 190 }
 191
 192 static int rxq2vq(int rxq)
 193 {
 194         return rxq * 2;
 195 }
 196
 197 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 198 {
 199         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 200 }
 201
 202 /*
 203  * private is used to chain pages for big packets, put the whole
 204  * most recent used list in the beginning for reuse
 205  */
 206 static void give_pages(struct receive_queue *rq, struct page *page)
 207 {
 208         struct page *end;
 209
 210         /* Find end of list, sew whole thing into vi->rq.pages. */
 211         for (end = page; end->private; end = (struct page *)end->private);
 212         end->private = (unsigned long)rq->pages;
 213         rq->pages = page;
 214 }
 215
 216 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 217 {
 218         struct page *p = rq->pages;
 219
 220         if (p) {
 221                 rq->pages = (struct page *)p->private;
 222                 /* clear private here, it is used to chain pages */
 223                 p->private = 0;
 224         } else
 225                 p = alloc_page(gfp_mask);
 226         return p;
 227 }
 228
 229 static void skb_xmit_done(struct virtqueue *vq)
 230 {
 231         struct virtnet_info *vi = vq->vdev->priv;
 232
 233         /* Suppress further interrupts. */
 234         virtqueue_disable_cb(vq);
 235
 236         /* We were probably waiting for more output buffers. */
 237         netif_wake_subqueue(vi->dev, vq2txq(vq));
 238 }
 239
 240 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
 241 {
 242         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
 243         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
 244 }
 245
 246 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
 247 {
 248         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
 249
 250 }
 251
 252 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 253 {
 254         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
 255         return (unsigned long)buf | (size - 1);
 256 }
 257
 258 /* Called from bottom half context */
 259 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 260                                    struct receive_queue *rq,
 261                                    struct page *page, unsigned int offset,
 262                                    unsigned int len, unsigned int truesize)
 263 {
 264         struct sk_buff *skb;
 265         struct virtio_net_hdr_mrg_rxbuf *hdr;
 266         unsigned int copy, hdr_len, hdr_padded_len;
 267         char *p;
 268
 269         p = page_address(page) + offset;
 270
 271         /* copy small packet so we can reuse these pages for small data */
 272         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 273         if (unlikely(!skb))
 274                 return NULL;
 275
 276         hdr = skb_vnet_hdr(skb);
 277
 278         hdr_len = vi->hdr_len;
 279         if (vi->mergeable_rx_bufs)
 280                 hdr_padded_len = sizeof *hdr;
 281         else
 282                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 283
 284         memcpy(hdr, p, hdr_len);
 285
 286         len -= hdr_len;
 287         offset += hdr_padded_len;
 288         p += hdr_padded_len;
 289
 290         copy = len;
 291         if (copy > skb_tailroom(skb))
 292                 copy = skb_tailroom(skb);
 293         memcpy(skb_put(skb, copy), p, copy);
 294
 295         len -= copy;
 296         offset += copy;
 297
 298         if (vi->mergeable_rx_bufs) {
 299                 if (len)
 300                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 301                 else
 302                         put_page(page);
 303                 return skb;
 304         }
 305
 306         /*
 307          * Verify that we can indeed put this data into a skb.
 308          * This is here to handle cases when the device erroneously
 309          * tries to receive more than is possible. This is usually
 310          * the case of a broken device.
 311          */
 312         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 313                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 314                 dev_kfree_skb(skb);
 315                 return NULL;
 316         }
 317         BUG_ON(offset >= PAGE_SIZE);
 318         while (len) {
 319                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 320                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 321                                 frag_size, truesize);
 322                 len -= frag_size;
 323                 page = (struct page *)page->private;
 324                 offset = 0;
 325         }
 326
 327         if (page)
 328                 give_pages(rq, page);
 329
 330         return skb;
 331 }
 332
 333 static void virtnet_xdp_xmit(struct virtnet_info *vi,
 334                              struct receive_queue *rq,
 335                              struct send_queue *sq,
 336                              struct xdp_buff *xdp)
 337 {
 338         struct page *page = virt_to_head_page(xdp->data);
 339         struct virtio_net_hdr_mrg_rxbuf *hdr;
 340         unsigned int num_sg, len;
 341         void *xdp_sent;
 342         int err;
 343
 344         /* Free up any pending old buffers before queueing new ones. */
 345         while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 346                 struct page *sent_page = virt_to_head_page(xdp_sent);
 347
 348                 if (vi->mergeable_rx_bufs)
 349                         put_page(sent_page);
 350                 else
 351                         give_pages(rq, sent_page);
 352         }
 353
 354         /* Zero header and leave csum up to XDP layers */
 355         hdr = xdp->data;
 356         memset(hdr, 0, vi->hdr_len);
 357
 358         num_sg = 1;
 359         sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data);
 360         err = virtqueue_add_outbuf(sq->vq, sq->sg, num_sg,
 361                                    xdp->data, GFP_ATOMIC);
 362         if (unlikely(err)) {
 363                 if (vi->mergeable_rx_bufs)
 364                         put_page(page);
 365                 else
 366                         give_pages(rq, page);
 367                 return; // On error abort to avoid unnecessary kick
 368         } else if (!vi->mergeable_rx_bufs) {
 369                 /* If not mergeable bufs must be big packets so cleanup pages */
 370                 give_pages(rq, (struct page *)page->private);
 371                 page->private = 0;
 372         }
 373
 374         virtqueue_kick(sq->vq);
 375 }
 376
 377 static u32 do_xdp_prog(struct virtnet_info *vi,
 378                        struct receive_queue *rq,
 379                        struct bpf_prog *xdp_prog,
 380                        struct page *page, int offset, int len)
 381 {
 382         int hdr_padded_len;
 383         struct xdp_buff xdp;
 384         unsigned int qp;
 385         u32 act;
 386         u8 *buf;
 387
 388         buf = page_address(page) + offset;
 389
 390         if (vi->mergeable_rx_bufs)
 391                 hdr_padded_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 392         else
 393                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 394
 395         xdp.data = buf + hdr_padded_len;
 396         xdp.data_end = xdp.data + (len - vi->hdr_len);
 397
 398         act = bpf_prog_run_xdp(xdp_prog, &xdp);
 399         switch (act) {
 400         case XDP_PASS:
 401                 return XDP_PASS;
 402         case XDP_TX:
 403                 qp = vi->curr_queue_pairs -
 404                         vi->xdp_queue_pairs +
 405                         smp_processor_id();
 406                 xdp.data = buf + (vi->mergeable_rx_bufs ? 0 : 4);
 407                 virtnet_xdp_xmit(vi, rq, &vi->sq[qp], &xdp);
 408                 return XDP_TX;
 409         default:
 410                 bpf_warn_invalid_xdp_action(act);
 411         case XDP_ABORTED:
 412         case XDP_DROP:
 413                 return XDP_DROP;
 414         }
 415 }
 416
 417 static struct sk_buff *receive_small(struct virtnet_info *vi, void *buf, unsigned int len)
 418 {
 419         struct sk_buff * skb = buf;
 420
 421         len -= vi->hdr_len;
 422         skb_trim(skb, len);
 423
 424         return skb;
 425 }
 426
 427 static struct sk_buff *receive_big(struct net_device *dev,
 428                                    struct virtnet_info *vi,
 429                                    struct receive_queue *rq,
 430                                    void *buf,
 431                                    unsigned int len)
 432 {
 433         struct bpf_prog *xdp_prog;
 434         struct page *page = buf;
 435         struct sk_buff *skb;
 436
 437         rcu_read_lock();
 438         xdp_prog = rcu_dereference(rq->xdp_prog);
 439         if (xdp_prog) {
 440                 struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 441                 u32 act;
 442
 443                 if (unlikely(hdr->hdr.gso_type))
 444                         goto err_xdp;
 445                 act = do_xdp_prog(vi, rq, xdp_prog, page, 0, len);
 446                 switch (act) {
 447                 case XDP_PASS:
 448                         break;
 449                 case XDP_TX:
 450                         rcu_read_unlock();
 451                         goto xdp_xmit;
 452                 case XDP_DROP:
 453                 default:
 454                         goto err_xdp;
 455                 }
 456         }
 457         rcu_read_unlock();
 458
 459         skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 460         if (unlikely(!skb))
 461                 goto err;
 462
 463         return skb;
 464
 465 err_xdp:
 466         rcu_read_unlock();
 467 err:
 468         dev->stats.rx_dropped++;
 469         give_pages(rq, page);
 470 xdp_xmit:
 471         return NULL;
 472 }
 473
 474 /* The conditions to enable XDP should preclude the underlying device from
 475  * sending packets across multiple buffers (num_buf > 1). However per spec
 476  * it does not appear to be illegal to do so but rather just against convention.
 477  * So in order to avoid making a system unresponsive the packets are pushed
 478  * into a page and the XDP program is run. This will be extremely slow and we
 479  * push a warning to the user to fix this as soon as possible. Fixing this may
 480  * require resolving the underlying hardware to determine why multiple buffers
 481  * are being received or simply loading the XDP program in the ingress stack
 482  * after the skb is built because there is no advantage to running it here
 483  * anymore.
 484  */
 485 static struct page *xdp_linearize_page(struct receive_queue *rq,
 486                                        u16 *num_buf,
 487                                        struct page *p,
 488                                        int offset,
 489                                        unsigned int *len)
 490 {
 491         struct page *page = alloc_page(GFP_ATOMIC);
 492         unsigned int page_off = 0;
 493
 494         if (!page)
 495                 return NULL;
 496
 497         memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
 498         page_off += *len;
 499
 500         while (--*num_buf) {
 501                 unsigned int buflen;
 502                 unsigned long ctx;
 503                 void *buf;
 504                 int off;
 505
 506                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &buflen);
 507                 if (unlikely(!ctx))
 508                         goto err_buf;
 509
 510                 buf = mergeable_ctx_to_buf_address(ctx);
 511                 p = virt_to_head_page(buf);
 512                 off = buf - page_address(p);
 513
 514                 /* guard against a misconfigured or uncooperative backend that
 515                  * is sending packet larger than the MTU.
 516                  */
 517                 if ((page_off + buflen) > PAGE_SIZE) {
 518                         put_page(p);
 519                         goto err_buf;
 520                 }
 521
 522                 memcpy(page_address(page) + page_off,
 523                        page_address(p) + off, buflen);
 524                 page_off += buflen;
 525                 put_page(p);
 526         }
 527
 528         *len = page_off;
 529         return page;
 530 err_buf:
 531         __free_pages(page, 0);
 532         return NULL;
 533 }
 534
 535 static struct sk_buff *receive_mergeable(struct net_device *dev,
 536                                          struct virtnet_info *vi,
 537                                          struct receive_queue *rq,
 538                                          unsigned long ctx,
 539                                          unsigned int len)
 540 {
 541         void *buf = mergeable_ctx_to_buf_address(ctx);
 542         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 543         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 544         struct page *page = virt_to_head_page(buf);
 545         int offset = buf - page_address(page);
 546         struct sk_buff *head_skb, *curr_skb;
 547         struct bpf_prog *xdp_prog;
 548         unsigned int truesize;
 549
 550         head_skb = NULL;
 551
 552         rcu_read_lock();
 553         xdp_prog = rcu_dereference(rq->xdp_prog);
 554         if (xdp_prog) {
 555                 struct page *xdp_page;
 556                 u32 act;
 557
 558                 /* This happens when rx buffer size is underestimated */
 559                 if (unlikely(num_buf > 1)) {
 560                         /* linearize data for XDP */
 561                         xdp_page = xdp_linearize_page(rq, &num_buf,
 562                                                       page, offset, &len);
 563                         if (!xdp_page)
 564                                 goto err_xdp;
 565                         offset = 0;
 566                 } else {
 567                         xdp_page = page;
 568                 }
 569
 570                 /* Transient failure which in theory could occur if
 571                  * in-flight packets from before XDP was enabled reach
 572                  * the receive path after XDP is loaded. In practice I
 573                  * was not able to create this condition.
 574                  */
 575                 if (unlikely(hdr->hdr.gso_type))
 576                         goto err_xdp;
 577
 578                 act = do_xdp_prog(vi, rq, xdp_prog, xdp_page, offset, len);
 579                 switch (act) {
 580                 case XDP_PASS:
 581                         /* We can only create skb based on xdp_page. */
 582                         if (unlikely(xdp_page != page)) {
 583                                 rcu_read_unlock();
 584                                 put_page(page);
 585                                 head_skb = page_to_skb(vi, rq, xdp_page,
 586                                                        0, len, PAGE_SIZE);
 587                                 return head_skb;
 588                         }
 589                         break;
 590                 case XDP_TX:
 591                         if (unlikely(xdp_page != page))
 592                                 goto err_xdp;
 593                         rcu_read_unlock();
 594                         goto xdp_xmit;
 595                 case XDP_DROP:
 596                 default:
 597                         if (unlikely(xdp_page != page))
 598                                 __free_pages(xdp_page, 0);
 599                         goto err_xdp;
 600                 }
 601         }
 602         rcu_read_unlock();
 603
 604         truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 605         head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
 606         curr_skb = head_skb;
 607
 608         if (unlikely(!curr_skb))
 609                 goto err_skb;
 610         while (--num_buf) {
 611                 int num_skb_frags;
 612
 613                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 614                 if (unlikely(!ctx)) {
 615                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 616                                  dev->name, num_buf,
 617                                  virtio16_to_cpu(vi->vdev,
 618                                                  hdr->num_buffers));
 619                         dev->stats.rx_length_errors++;
 620                         goto err_buf;
 621                 }
 622
 623                 buf = mergeable_ctx_to_buf_address(ctx);
 624                 page = virt_to_head_page(buf);
 625
 626                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 627                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 628                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 629
 630                         if (unlikely(!nskb))
 631                                 goto err_skb;
 632                         if (curr_skb == head_skb)
 633                                 skb_shinfo(curr_skb)->frag_list = nskb;
 634                         else
 635                                 curr_skb->next = nskb;
 636                         curr_skb = nskb;
 637                         head_skb->truesize += nskb->truesize;
 638                         num_skb_frags = 0;
 639                 }
 640                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 641                 if (curr_skb != head_skb) {
 642                         head_skb->data_len += len;
 643                         head_skb->len += len;
 644                         head_skb->truesize += truesize;
 645                 }
 646                 offset = buf - page_address(page);
 647                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 648                         put_page(page);
 649                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 650                                              len, truesize);
 651                 } else {
 652                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 653                                         offset, len, truesize);
 654                 }
 655         }
 656
 657         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
 658         return head_skb;
 659
 660 err_xdp:
 661         rcu_read_unlock();
 662 err_skb:
 663         put_page(page);
 664         while (--num_buf) {
 665                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 666                 if (unlikely(!ctx)) {
 667                         pr_debug("%s: rx error: %d buffers missing\n",
 668                                  dev->name, num_buf);
 669                         dev->stats.rx_length_errors++;
 670                         break;
 671                 }
 672                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
 673                 put_page(page);
 674         }
 675 err_buf:
 676         dev->stats.rx_dropped++;
 677         dev_kfree_skb(head_skb);
 678 xdp_xmit:
 679         return NULL;
 680 }
 681
 682 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 683                         void *buf, unsigned int len)
 684 {
 685         struct net_device *dev = vi->dev;
 686         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 687         struct sk_buff *skb;
 688         struct virtio_net_hdr_mrg_rxbuf *hdr;
 689
 690         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 691                 pr_debug("%s: short packet %i\n", dev->name, len);
 692                 dev->stats.rx_length_errors++;
 693                 if (vi->mergeable_rx_bufs) {
 694                         unsigned long ctx = (unsigned long)buf;
 695                         void *base = mergeable_ctx_to_buf_address(ctx);
 696                         put_page(virt_to_head_page(base));
 697                 } else if (vi->big_packets) {
 698                         give_pages(rq, buf);
 699                 } else {
 700                         dev_kfree_skb(buf);
 701                 }
 702                 return;
 703         }
 704
 705         if (vi->mergeable_rx_bufs)
 706                 skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len);
 707         else if (vi->big_packets)
 708                 skb = receive_big(dev, vi, rq, buf, len);
 709         else
 710                 skb = receive_small(vi, buf, len);
 711
 712         if (unlikely(!skb))
 713                 return;
 714
 715         hdr = skb_vnet_hdr(skb);
 716
 717         u64_stats_update_begin(&stats->rx_syncp);
 718         stats->rx_bytes += skb->len;
 719         stats->rx_packets++;
 720         u64_stats_update_end(&stats->rx_syncp);
 721
 722         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
 723                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 724
 725         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
 726                                   virtio_is_little_endian(vi->vdev))) {
 727                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
 728                                      dev->name, hdr->hdr.gso_type,
 729                                      hdr->hdr.gso_size);
 730                 goto frame_err;
 731         }
 732
 733         skb->protocol = eth_type_trans(skb, dev);
 734         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 735                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 736
 737         napi_gro_receive(&rq->napi, skb);
 738         return;
 739
 740 frame_err:
 741         dev->stats.rx_frame_errors++;
 742         dev_kfree_skb(skb);
 743 }
 744
 745 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 746                              gfp_t gfp)
 747 {
 748         struct sk_buff *skb;
 749         struct virtio_net_hdr_mrg_rxbuf *hdr;
 750         int err;
 751
 752         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 753         if (unlikely(!skb))
 754                 return -ENOMEM;
 755
 756         skb_put(skb, GOOD_PACKET_LEN);
 757
 758         hdr = skb_vnet_hdr(skb);
 759         sg_init_table(rq->sg, 2);
 760         sg_set_buf(rq->sg, hdr, vi->hdr_len);
 761         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 762
 763         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 764         if (err < 0)
 765                 dev_kfree_skb(skb);
 766
 767         return err;
 768 }
 769
 770 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
 771                            gfp_t gfp)
 772 {
 773         struct page *first, *list = NULL;
 774         char *p;
 775         int i, err, offset;
 776
 777         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 778
 779         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 780         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 781                 first = get_a_page(rq, gfp);
 782                 if (!first) {
 783                         if (list)
 784                                 give_pages(rq, list);
 785                         return -ENOMEM;
 786                 }
 787                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 788
 789                 /* chain new page in list head to match sg */
 790                 first->private = (unsigned long)list;
 791                 list = first;
 792         }
 793
 794         first = get_a_page(rq, gfp);
 795         if (!first) {
 796                 give_pages(rq, list);
 797                 return -ENOMEM;
 798         }
 799         p = page_address(first);
 800
 801         /* rq->sg[0], rq->sg[1] share the same page */
 802         /* a separated rq->sg[0] for header - required in case !any_header_sg */
 803         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
 804
 805         /* rq->sg[1] for data packet, from offset */
 806         offset = sizeof(struct padded_vnet_hdr);
 807         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 808
 809         /* chain first in list head */
 810         first->private = (unsigned long)list;
 811         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 812                                   first, gfp);
 813         if (err < 0)
 814                 give_pages(rq, first);
 815
 816         return err;
 817 }
 818
 819 static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
 820 {
 821         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 822         unsigned int len;
 823
 824         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
 825                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 826         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 827 }
 828
 829 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 830 {
 831         struct page_frag *alloc_frag = &rq->alloc_frag;
 832         char *buf;
 833         unsigned long ctx;
 834         int err;
 835         unsigned int len, hole;
 836
 837         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 838         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 839                 return -ENOMEM;
 840
 841         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 842         ctx = mergeable_buf_to_ctx(buf, len);
 843         get_page(alloc_frag->page);
 844         alloc_frag->offset += len;
 845         hole = alloc_frag->size - alloc_frag->offset;
 846         if (hole < len) {
 847                 /* To avoid internal fragmentation, if there is very likely not
 848                  * enough space for another buffer, add the remaining space to
 849                  * the current buffer. This extra space is not included in
 850                  * the truesize stored in ctx.
 851                  */
 852                 len += hole;
 853                 alloc_frag->offset += hole;
 854         }
 855
 856         sg_init_one(rq->sg, buf, len);
 857         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 858         if (err < 0)
 859                 put_page(virt_to_head_page(buf));
 860
 861         return err;
 862 }
 863
 864 /*
 865  * Returns false if we couldn't fill entirely (OOM).
 866  *
 867  * Normally run in the receive path, but can also be run from ndo_open
 868  * before we're receiving packets, or from refill_work which is
 869  * careful to disable receiving (using napi_disable).
 870  */
 871 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
 872                           gfp_t gfp)
 873 {
 874         int err;
 875         bool oom;
 876
 877         gfp |= __GFP_COLD;
 878         do {
 879                 if (vi->mergeable_rx_bufs)
 880                         err = add_recvbuf_mergeable(rq, gfp);
 881                 else if (vi->big_packets)
 882                         err = add_recvbuf_big(vi, rq, gfp);
 883                 else
 884                         err = add_recvbuf_small(vi, rq, gfp);
 885
 886                 oom = err == -ENOMEM;
 887                 if (err)
 888                         break;
 889         } while (rq->vq->num_free);
 890         virtqueue_kick(rq->vq);
 891         return !oom;
 892 }
 893
 894 static void skb_recv_done(struct virtqueue *rvq)
 895 {
 896         struct virtnet_info *vi = rvq->vdev->priv;
 897         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 898
 899         /* Schedule NAPI, Suppress further interrupts if successful. */
 900         if (napi_schedule_prep(&rq->napi)) {
 901                 virtqueue_disable_cb(rvq);
 902                 __napi_schedule(&rq->napi);
 903         }
 904 }
 905
 906 static void virtnet_napi_enable(struct receive_queue *rq)
 907 {
 908         napi_enable(&rq->napi);
 909
 910         /* If all buffers were filled by other side before we napi_enabled, we
 911          * won't get another interrupt, so process any outstanding packets
 912          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 913          * We synchronize against interrupts via NAPI_STATE_SCHED */
 914         if (napi_schedule_prep(&rq->napi)) {
 915                 virtqueue_disable_cb(rq->vq);
 916                 local_bh_disable();
 917                 __napi_schedule(&rq->napi);
 918                 local_bh_enable();
 919         }
 920 }
 921
 922 static void refill_work(struct work_struct *work)
 923 {
 924         struct virtnet_info *vi =
 925                 container_of(work, struct virtnet_info, refill.work);
 926         bool still_empty;
 927         int i;
 928
 929         for (i = 0; i < vi->curr_queue_pairs; i++) {
 930                 struct receive_queue *rq = &vi->rq[i];
 931
 932                 napi_disable(&rq->napi);
 933                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 934                 virtnet_napi_enable(rq);
 935
 936                 /* In theory, this can happen: if we don't get any buffers in
 937                  * we will *never* try to fill again.
 938                  */
 939                 if (still_empty)
 940                         schedule_delayed_work(&vi->refill, HZ/2);
 941         }
 942 }
 943
 944 static int virtnet_receive(struct receive_queue *rq, int budget)
 945 {
 946         struct virtnet_info *vi = rq->vq->vdev->priv;
 947         unsigned int len, received = 0;
 948         void *buf;
 949
 950         while (received < budget &&
 951                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 952                 receive_buf(vi, rq, buf, len);
 953                 received++;
 954         }
 955
 956         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 957                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
 958                         schedule_delayed_work(&vi->refill, 0);
 959         }
 960
 961         return received;
 962 }
 963
 964 static int virtnet_poll(struct napi_struct *napi, int budget)
 965 {
 966         struct receive_queue *rq =
 967                 container_of(napi, struct receive_queue, napi);
 968         unsigned int r, received;
 969
 970         received = virtnet_receive(rq, budget);
 971
 972         /* Out of packets? */
 973         if (received < budget) {
 974                 r = virtqueue_enable_cb_prepare(rq->vq);
 975                 napi_complete_done(napi, received);
 976                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 977                     napi_schedule_prep(napi)) {
 978                         virtqueue_disable_cb(rq->vq);
 979                         __napi_schedule(napi);
 980                 }
 981         }
 982
 983         return received;
 984 }
 985
 986 #ifdef CONFIG_NET_RX_BUSY_POLL
 987 /* must be called with local_bh_disable()d */
 988 static int virtnet_busy_poll(struct napi_struct *napi)
 989 {
 990         struct receive_queue *rq =
 991                 container_of(napi, struct receive_queue, napi);
 992         struct virtnet_info *vi = rq->vq->vdev->priv;
 993         int r, received = 0, budget = 4;
 994
 995         if (!(vi->status & VIRTIO_NET_S_LINK_UP))
 996                 return LL_FLUSH_FAILED;
 997
 998         if (!napi_schedule_prep(napi))
 999                 return LL_FLUSH_BUSY;
1000
1001         virtqueue_disable_cb(rq->vq);
1002
1003 again:
1004         received += virtnet_receive(rq, budget);
1005
1006         r = virtqueue_enable_cb_prepare(rq->vq);
1007         clear_bit(NAPI_STATE_SCHED, &napi->state);
1008         if (unlikely(virtqueue_poll(rq->vq, r)) &&
1009             napi_schedule_prep(napi)) {
1010                 virtqueue_disable_cb(rq->vq);
1011                 if (received < budget) {
1012                         budget -= received;
1013                         goto again;
1014                 } else {
1015                         __napi_schedule(napi);
1016                 }
1017         }
1018
1019         return received;
1020 }
1021 #endif  /* CONFIG_NET_RX_BUSY_POLL */
1022
1023 static int virtnet_open(struct net_device *dev)
1024 {
1025         struct virtnet_info *vi = netdev_priv(dev);
1026         int i;
1027
1028         for (i = 0; i < vi->max_queue_pairs; i++) {
1029                 if (i < vi->curr_queue_pairs)
1030                         /* Make sure we have some buffers: if oom use wq. */
1031                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1032                                 schedule_delayed_work(&vi->refill, 0);
1033                 virtnet_napi_enable(&vi->rq[i]);
1034         }
1035
1036         return 0;
1037 }
1038
1039 static void free_old_xmit_skbs(struct send_queue *sq)
1040 {
1041         struct sk_buff *skb;
1042         unsigned int len;
1043         struct virtnet_info *vi = sq->vq->vdev->priv;
1044         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
1045
1046         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1047                 pr_debug("Sent skb %p\n", skb);
1048
1049                 u64_stats_update_begin(&stats->tx_syncp);
1050                 stats->tx_bytes += skb->len;
1051                 stats->tx_packets++;
1052                 u64_stats_update_end(&stats->tx_syncp);
1053
1054                 dev_kfree_skb_any(skb);
1055         }
1056 }
1057
1058 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1059 {
1060         struct virtio_net_hdr_mrg_rxbuf *hdr;
1061         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1062         struct virtnet_info *vi = sq->vq->vdev->priv;
1063         unsigned num_sg;
1064         unsigned hdr_len = vi->hdr_len;
1065         bool can_push;
1066
1067         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1068
1069         can_push = vi->any_header_sg &&
1070                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1071                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1072         /* Even if we can, don't push here yet as this would skew
1073          * csum_start offset below. */
1074         if (can_push)
1075                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1076         else
1077                 hdr = skb_vnet_hdr(skb);
1078
1079         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1080                                     virtio_is_little_endian(vi->vdev)))
1081                 BUG();
1082
1083         if (vi->mergeable_rx_bufs)
1084                 hdr->num_buffers = 0;
1085
1086         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1087         if (can_push) {
1088                 __skb_push(skb, hdr_len);
1089                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1090                 /* Pull header back to avoid skew in tx bytes calculations. */
1091                 __skb_pull(skb, hdr_len);
1092         } else {
1093                 sg_set_buf(sq->sg, hdr, hdr_len);
1094                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
1095         }
1096         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1097 }
1098
1099 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1100 {
1101         struct virtnet_info *vi = netdev_priv(dev);
1102         int qnum = skb_get_queue_mapping(skb);
1103         struct send_queue *sq = &vi->sq[qnum];
1104         int err;
1105         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1106         bool kick = !skb->xmit_more;
1107
1108         /* Free up any pending old buffers before queueing new ones. */
1109         free_old_xmit_skbs(sq);
1110
1111         /* timestamp packet in software */
1112         skb_tx_timestamp(skb);
1113
1114         /* Try to transmit */
1115         err = xmit_skb(sq, skb);
1116
1117         /* This should not happen! */
1118         if (unlikely(err)) {
1119                 dev->stats.tx_fifo_errors++;
1120                 if (net_ratelimit())
1121                         dev_warn(&dev->dev,
1122                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
1123                 dev->stats.tx_dropped++;
1124                 dev_kfree_skb_any(skb);
1125                 return NETDEV_TX_OK;
1126         }
1127
1128         /* Don't wait up for transmitted skbs to be freed. */
1129         skb_orphan(skb);
1130         nf_reset(skb);
1131
1132         /* If running out of space, stop queue to avoid getting packets that we
1133          * are then unable to transmit.
1134          * An alternative would be to force queuing layer to requeue the skb by
1135          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1136          * returned in a normal path of operation: it means that driver is not
1137          * maintaining the TX queue stop/start state properly, and causes
1138          * the stack to do a non-trivial amount of useless work.
1139          * Since most packets only take 1 or 2 ring slots, stopping the queue
1140          * early means 16 slots are typically wasted.
1141          */
1142         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1143                 netif_stop_subqueue(dev, qnum);
1144                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1145                         /* More just got used, free them then recheck. */
1146                         free_old_xmit_skbs(sq);
1147                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1148                                 netif_start_subqueue(dev, qnum);
1149                                 virtqueue_disable_cb(sq->vq);
1150                         }
1151                 }
1152         }
1153
1154         if (kick || netif_xmit_stopped(txq))
1155                 virtqueue_kick(sq->vq);
1156
1157         return NETDEV_TX_OK;
1158 }
1159
1160 /*
1161  * Send command via the control virtqueue and check status.  Commands
1162  * supported by the hypervisor, as indicated by feature bits, should
1163  * never fail unless improperly formatted.
1164  */
1165 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1166                                  struct scatterlist *out)
1167 {
1168         struct scatterlist *sgs[4], hdr, stat;
1169         unsigned out_num = 0, tmp;
1170
1171         /* Caller should know better */
1172         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1173
1174         vi->ctrl_status = ~0;
1175         vi->ctrl_hdr.class = class;
1176         vi->ctrl_hdr.cmd = cmd;
1177         /* Add header */
1178         sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
1179         sgs[out_num++] = &hdr;
1180
1181         if (out)
1182                 sgs[out_num++] = out;
1183
1184         /* Add return status. */
1185         sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
1186         sgs[out_num] = &stat;
1187
1188         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1189         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1190
1191         if (unlikely(!virtqueue_kick(vi->cvq)))
1192                 return vi->ctrl_status == VIRTIO_NET_OK;
1193
1194         /* Spin for a response, the kick causes an ioport write, trapping
1195          * into the hypervisor, so the request should be handled immediately.
1196          */
1197         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1198                !virtqueue_is_broken(vi->cvq))
1199                 cpu_relax();
1200
1201         return vi->ctrl_status == VIRTIO_NET_OK;
1202 }
1203
1204 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1205 {
1206         struct virtnet_info *vi = netdev_priv(dev);
1207         struct virtio_device *vdev = vi->vdev;
1208         int ret;
1209         struct sockaddr *addr;
1210         struct scatterlist sg;
1211
1212         addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1213         if (!addr)
1214                 return -ENOMEM;
1215         memcpy(addr, p, sizeof(*addr));
1216
1217         ret = eth_prepare_mac_addr_change(dev, addr);
1218         if (ret)
1219                 goto out;
1220
1221         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1222                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1223                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1224                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1225                         dev_warn(&vdev->dev,
1226                                  "Failed to set mac address by vq command.\n");
1227                         ret = -EINVAL;
1228                         goto out;
1229                 }
1230         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1231                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1232                 unsigned int i;
1233
1234                 /* Naturally, this has an atomicity problem. */
1235                 for (i = 0; i < dev->addr_len; i++)
1236                         virtio_cwrite8(vdev,
1237                                        offsetof(struct virtio_net_config, mac) +
1238                                        i, addr->sa_data[i]);
1239         }
1240
1241         eth_commit_mac_addr_change(dev, p);
1242         ret = 0;
1243
1244 out:
1245         kfree(addr);
1246         return ret;
1247 }
1248
1249 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1250                                                struct rtnl_link_stats64 *tot)
1251 {
1252         struct virtnet_info *vi = netdev_priv(dev);
1253         int cpu;
1254         unsigned int start;
1255
1256         for_each_possible_cpu(cpu) {
1257                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1258                 u64 tpackets, tbytes, rpackets, rbytes;
1259
1260                 do {
1261                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1262                         tpackets = stats->tx_packets;
1263                         tbytes   = stats->tx_bytes;
1264                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1265
1266                 do {
1267                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1268                         rpackets = stats->rx_packets;
1269                         rbytes   = stats->rx_bytes;
1270                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1271
1272                 tot->rx_packets += rpackets;
1273                 tot->tx_packets += tpackets;
1274                 tot->rx_bytes   += rbytes;
1275                 tot->tx_bytes   += tbytes;
1276         }
1277
1278         tot->tx_dropped = dev->stats.tx_dropped;
1279         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1280         tot->rx_dropped = dev->stats.rx_dropped;
1281         tot->rx_length_errors = dev->stats.rx_length_errors;
1282         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1283
1284         return tot;
1285 }
1286
1287 #ifdef CONFIG_NET_POLL_CONTROLLER
1288 static void virtnet_netpoll(struct net_device *dev)
1289 {
1290         struct virtnet_info *vi = netdev_priv(dev);
1291         int i;
1292
1293         for (i = 0; i < vi->curr_queue_pairs; i++)
1294                 napi_schedule(&vi->rq[i].napi);
1295 }
1296 #endif
1297
1298 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1299 {
1300         rtnl_lock();
1301         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1302                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1303                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1304         rtnl_unlock();
1305 }
1306
1307 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1308 {
1309         struct scatterlist sg;
1310         struct net_device *dev = vi->dev;
1311
1312         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1313                 return 0;
1314
1315         vi->ctrl_mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1316         sg_init_one(&sg, &vi->ctrl_mq, sizeof(vi->ctrl_mq));
1317
1318         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1319                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1320                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1321                          queue_pairs);
1322                 return -EINVAL;
1323         } else {
1324                 vi->curr_queue_pairs = queue_pairs;
1325                 /* virtnet_open() will refill when device is going to up. */
1326                 if (dev->flags & IFF_UP)
1327                         schedule_delayed_work(&vi->refill, 0);
1328         }
1329
1330         return 0;
1331 }
1332
1333 static int virtnet_close(struct net_device *dev)
1334 {
1335         struct virtnet_info *vi = netdev_priv(dev);
1336         int i;
1337
1338         /* Make sure refill_work doesn't re-enable napi! */
1339         cancel_delayed_work_sync(&vi->refill);
1340
1341         for (i = 0; i < vi->max_queue_pairs; i++)
1342                 napi_disable(&vi->rq[i].napi);
1343
1344         return 0;
1345 }
1346
1347 static void virtnet_set_rx_mode(struct net_device *dev)
1348 {
1349         struct virtnet_info *vi = netdev_priv(dev);
1350         struct scatterlist sg[2];
1351         struct virtio_net_ctrl_mac *mac_data;
1352         struct netdev_hw_addr *ha;
1353         int uc_count;
1354         int mc_count;
1355         void *buf;
1356         int i;
1357
1358         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1359         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1360                 return;
1361
1362         vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1363         vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1364
1365         sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1366
1367         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1368                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1369                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1370                          vi->ctrl_promisc ? "en" : "dis");
1371
1372         sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1373
1374         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1375                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1376                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1377                          vi->ctrl_allmulti ? "en" : "dis");
1378
1379         uc_count = netdev_uc_count(dev);
1380         mc_count = netdev_mc_count(dev);
1381         /* MAC filter - use one buffer for both lists */
1382         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1383                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1384         mac_data = buf;
1385         if (!buf)
1386                 return;
1387
1388         sg_init_table(sg, 2);
1389
1390         /* Store the unicast list and count in the front of the buffer */
1391         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1392         i = 0;
1393         netdev_for_each_uc_addr(ha, dev)
1394                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1395
1396         sg_set_buf(&sg[0], mac_data,
1397                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1398
1399         /* multicast list and count fill the end */
1400         mac_data = (void *)&mac_data->macs[uc_count][0];
1401
1402         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1403         i = 0;
1404         netdev_for_each_mc_addr(ha, dev)
1405                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1406
1407         sg_set_buf(&sg[1], mac_data,
1408                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1409
1410         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1411                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1412                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1413
1414         kfree(buf);
1415 }
1416
1417 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1418                                    __be16 proto, u16 vid)
1419 {
1420         struct virtnet_info *vi = netdev_priv(dev);
1421         struct scatterlist sg;
1422
1423         vi->ctrl_vid = vid;
1424         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1425
1426         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1427                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1428                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1429         return 0;
1430 }
1431
1432 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1433                                     __be16 proto, u16 vid)
1434 {
1435         struct virtnet_info *vi = netdev_priv(dev);
1436         struct scatterlist sg;
1437
1438         vi->ctrl_vid = vid;
1439         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1440
1441         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1442                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1443                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1444         return 0;
1445 }
1446
1447 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1448 {
1449         int i;
1450
1451         if (vi->affinity_hint_set) {
1452                 for (i = 0; i < vi->max_queue_pairs; i++) {
1453                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1454                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1455                 }
1456
1457                 vi->affinity_hint_set = false;
1458         }
1459 }
1460
1461 static void virtnet_set_affinity(struct virtnet_info *vi)
1462 {
1463         int i;
1464         int cpu;
1465
1466         /* In multiqueue mode, when the number of cpu is equal to the number of
1467          * queue pairs, we let the queue pairs to be private to one cpu by
1468          * setting the affinity hint to eliminate the contention.
1469          */
1470         if (vi->curr_queue_pairs == 1 ||
1471             vi->max_queue_pairs != num_online_cpus()) {
1472                 virtnet_clean_affinity(vi, -1);
1473                 return;
1474         }
1475
1476         i = 0;
1477         for_each_online_cpu(cpu) {
1478                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1479                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1480                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1481                 i++;
1482         }
1483
1484         vi->affinity_hint_set = true;
1485 }
1486
1487 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1488 {
1489         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1490                                                    node);
1491         virtnet_set_affinity(vi);
1492         return 0;
1493 }
1494
1495 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1496 {
1497         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1498                                                    node_dead);
1499         virtnet_set_affinity(vi);
1500         return 0;
1501 }
1502
1503 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1504 {
1505         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1506                                                    node);
1507
1508         virtnet_clean_affinity(vi, cpu);
1509         return 0;
1510 }
1511
1512 static enum cpuhp_state virtionet_online;
1513
1514 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1515 {
1516         int ret;
1517
1518         ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
1519         if (ret)
1520                 return ret;
1521         ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1522                                                &vi->node_dead);
1523         if (!ret)
1524                 return ret;
1525         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1526         return ret;
1527 }
1528
1529 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
1530 {
1531         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1532         cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1533                                             &vi->node_dead);
1534 }
1535
1536 static void virtnet_get_ringparam(struct net_device *dev,
1537                                 struct ethtool_ringparam *ring)
1538 {
1539         struct virtnet_info *vi = netdev_priv(dev);
1540
1541         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1542         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1543         ring->rx_pending = ring->rx_max_pending;
1544         ring->tx_pending = ring->tx_max_pending;
1545 }
1546
1547
1548 static void virtnet_get_drvinfo(struct net_device *dev,
1549                                 struct ethtool_drvinfo *info)
1550 {
1551         struct virtnet_info *vi = netdev_priv(dev);
1552         struct virtio_device *vdev = vi->vdev;
1553
1554         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1555         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1556         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1557
1558 }
1559
1560 /* TODO: Eliminate OOO packets during switching */
1561 static int virtnet_set_channels(struct net_device *dev,
1562                                 struct ethtool_channels *channels)
1563 {
1564         struct virtnet_info *vi = netdev_priv(dev);
1565         u16 queue_pairs = channels->combined_count;
1566         int err;
1567
1568         /* We don't support separate rx/tx channels.
1569          * We don't allow setting 'other' channels.
1570          */
1571         if (channels->rx_count || channels->tx_count || channels->other_count)
1572                 return -EINVAL;
1573
1574         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1575                 return -EINVAL;
1576
1577         /* For now we don't support modifying channels while XDP is loaded
1578          * also when XDP is loaded all RX queues have XDP programs so we only
1579          * need to check a single RX queue.
1580          */
1581         if (vi->rq[0].xdp_prog)
1582                 return -EINVAL;
1583
1584         get_online_cpus();
1585         err = virtnet_set_queues(vi, queue_pairs);
1586         if (!err) {
1587                 netif_set_real_num_tx_queues(dev, queue_pairs);
1588                 netif_set_real_num_rx_queues(dev, queue_pairs);
1589
1590                 virtnet_set_affinity(vi);
1591         }
1592         put_online_cpus();
1593
1594         return err;
1595 }
1596
1597 static void virtnet_get_channels(struct net_device *dev,
1598                                  struct ethtool_channels *channels)
1599 {
1600         struct virtnet_info *vi = netdev_priv(dev);
1601
1602         channels->combined_count = vi->curr_queue_pairs;
1603         channels->max_combined = vi->max_queue_pairs;
1604         channels->max_other = 0;
1605         channels->rx_count = 0;
1606         channels->tx_count = 0;
1607         channels->other_count = 0;
1608 }
1609
1610 /* Check if the user is trying to change anything besides speed/duplex */
1611 static bool virtnet_validate_ethtool_cmd(const struct ethtool_cmd *cmd)
1612 {
1613         struct ethtool_cmd diff1 = *cmd;
1614         struct ethtool_cmd diff2 = {};
1615
1616         /* cmd is always set so we need to clear it, validate the port type
1617          * and also without autonegotiation we can ignore advertising
1618          */
1619         ethtool_cmd_speed_set(&diff1, 0);
1620         diff2.port = PORT_OTHER;
1621         diff1.advertising = 0;
1622         diff1.duplex = 0;
1623         diff1.cmd = 0;
1624
1625         return !memcmp(&diff1, &diff2, sizeof(diff1));
1626 }
1627
1628 static int virtnet_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1629 {
1630         struct virtnet_info *vi = netdev_priv(dev);
1631         u32 speed;
1632
1633         speed = ethtool_cmd_speed(cmd);
1634         /* don't allow custom speed and duplex */
1635         if (!ethtool_validate_speed(speed) ||
1636             !ethtool_validate_duplex(cmd->duplex) ||
1637             !virtnet_validate_ethtool_cmd(cmd))
1638                 return -EINVAL;
1639         vi->speed = speed;
1640         vi->duplex = cmd->duplex;
1641
1642         return 0;
1643 }
1644
1645 static int virtnet_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1646 {
1647         struct virtnet_info *vi = netdev_priv(dev);
1648
1649         ethtool_cmd_speed_set(cmd, vi->speed);
1650         cmd->duplex = vi->duplex;
1651         cmd->port = PORT_OTHER;
1652
1653         return 0;
1654 }
1655
1656 static void virtnet_init_settings(struct net_device *dev)
1657 {
1658         struct virtnet_info *vi = netdev_priv(dev);
1659
1660         vi->speed = SPEED_UNKNOWN;
1661         vi->duplex = DUPLEX_UNKNOWN;
1662 }
1663
1664 static const struct ethtool_ops virtnet_ethtool_ops = {
1665         .get_drvinfo = virtnet_get_drvinfo,
1666         .get_link = ethtool_op_get_link,
1667         .get_ringparam = virtnet_get_ringparam,
1668         .set_channels = virtnet_set_channels,
1669         .get_channels = virtnet_get_channels,
1670         .get_ts_info = ethtool_op_get_ts_info,
1671         .get_settings = virtnet_get_settings,
1672         .set_settings = virtnet_set_settings,
1673 };
1674
1675 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog)
1676 {
1677         unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
1678         struct virtnet_info *vi = netdev_priv(dev);
1679         struct bpf_prog *old_prog;
1680         u16 xdp_qp = 0, curr_qp;
1681         int i, err;
1682
1683         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1684             virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6)) {
1685                 netdev_warn(dev, "can't set XDP while host is implementing LRO, disable LRO first\n");
1686                 return -EOPNOTSUPP;
1687         }
1688
1689         if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
1690                 netdev_warn(dev, "XDP expects header/data in single page, any_header_sg required\n");
1691                 return -EINVAL;
1692         }
1693
1694         if (dev->mtu > max_sz) {
1695                 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
1696                 return -EINVAL;
1697         }
1698
1699         curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
1700         if (prog)
1701                 xdp_qp = nr_cpu_ids;
1702
1703         /* XDP requires extra queues for XDP_TX */
1704         if (curr_qp + xdp_qp > vi->max_queue_pairs) {
1705                 netdev_warn(dev, "request %i queues but max is %i\n",
1706                             curr_qp + xdp_qp, vi->max_queue_pairs);
1707                 return -ENOMEM;
1708         }
1709
1710         err = virtnet_set_queues(vi, curr_qp + xdp_qp);
1711         if (err) {
1712                 dev_warn(&dev->dev, "XDP Device queue allocation failure.\n");
1713                 return err;
1714         }
1715
1716         if (prog) {
1717                 prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
1718                 if (IS_ERR(prog)) {
1719                         virtnet_set_queues(vi, curr_qp);
1720                         return PTR_ERR(prog);
1721                 }
1722         }
1723
1724         vi->xdp_queue_pairs = xdp_qp;
1725         netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
1726
1727         for (i = 0; i < vi->max_queue_pairs; i++) {
1728                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
1729                 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
1730                 if (old_prog)
1731                         bpf_prog_put(old_prog);
1732         }
1733
1734         return 0;
1735 }
1736
1737 static bool virtnet_xdp_query(struct net_device *dev)
1738 {
1739         struct virtnet_info *vi = netdev_priv(dev);
1740         int i;
1741
1742         for (i = 0; i < vi->max_queue_pairs; i++) {
1743                 if (vi->rq[i].xdp_prog)
1744                         return true;
1745         }
1746         return false;
1747 }
1748
1749 static int virtnet_xdp(struct net_device *dev, struct netdev_xdp *xdp)
1750 {
1751         switch (xdp->command) {
1752         case XDP_SETUP_PROG:
1753                 return virtnet_xdp_set(dev, xdp->prog);
1754         case XDP_QUERY_PROG:
1755                 xdp->prog_attached = virtnet_xdp_query(dev);
1756                 return 0;
1757         default:
1758                 return -EINVAL;
1759         }
1760 }
1761
1762 static const struct net_device_ops virtnet_netdev = {
1763         .ndo_open            = virtnet_open,
1764         .ndo_stop            = virtnet_close,
1765         .ndo_start_xmit      = start_xmit,
1766         .ndo_validate_addr   = eth_validate_addr,
1767         .ndo_set_mac_address = virtnet_set_mac_address,
1768         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1769         .ndo_get_stats64     = virtnet_stats,
1770         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1771         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1772 #ifdef CONFIG_NET_POLL_CONTROLLER
1773         .ndo_poll_controller = virtnet_netpoll,
1774 #endif
1775 #ifdef CONFIG_NET_RX_BUSY_POLL
1776         .ndo_busy_poll          = virtnet_busy_poll,
1777 #endif
1778         .ndo_xdp                = virtnet_xdp,
1779 };
1780
1781 static void virtnet_config_changed_work(struct work_struct *work)
1782 {
1783         struct virtnet_info *vi =
1784                 container_of(work, struct virtnet_info, config_work);
1785         u16 v;
1786
1787         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1788                                  struct virtio_net_config, status, &v) < 0)
1789                 return;
1790
1791         if (v & VIRTIO_NET_S_ANNOUNCE) {
1792                 netdev_notify_peers(vi->dev);
1793                 virtnet_ack_link_announce(vi);
1794         }
1795
1796         /* Ignore unknown (future) status bits */
1797         v &= VIRTIO_NET_S_LINK_UP;
1798
1799         if (vi->status == v)
1800                 return;
1801
1802         vi->status = v;
1803
1804         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1805                 netif_carrier_on(vi->dev);
1806                 netif_tx_wake_all_queues(vi->dev);
1807         } else {
1808                 netif_carrier_off(vi->dev);
1809                 netif_tx_stop_all_queues(vi->dev);
1810         }
1811 }
1812
1813 static void virtnet_config_changed(struct virtio_device *vdev)
1814 {
1815         struct virtnet_info *vi = vdev->priv;
1816
1817         schedule_work(&vi->config_work);
1818 }
1819
1820 static void virtnet_free_queues(struct virtnet_info *vi)
1821 {
1822         int i;
1823
1824         for (i = 0; i < vi->max_queue_pairs; i++) {
1825                 napi_hash_del(&vi->rq[i].napi);
1826                 netif_napi_del(&vi->rq[i].napi);
1827         }
1828
1829         /* We called napi_hash_del() before netif_napi_del(),
1830          * we need to respect an RCU grace period before freeing vi->rq
1831          */
1832         synchronize_net();
1833
1834         kfree(vi->rq);
1835         kfree(vi->sq);
1836 }
1837
1838 static void free_receive_bufs(struct virtnet_info *vi)
1839 {
1840         struct bpf_prog *old_prog;
1841         int i;
1842
1843         rtnl_lock();
1844         for (i = 0; i < vi->max_queue_pairs; i++) {
1845                 while (vi->rq[i].pages)
1846                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1847
1848                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
1849                 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
1850                 if (old_prog)
1851                         bpf_prog_put(old_prog);
1852         }
1853         rtnl_unlock();
1854 }
1855
1856 static void free_receive_page_frags(struct virtnet_info *vi)
1857 {
1858         int i;
1859         for (i = 0; i < vi->max_queue_pairs; i++)
1860                 if (vi->rq[i].alloc_frag.page)
1861                         put_page(vi->rq[i].alloc_frag.page);
1862 }
1863
1864 static bool is_xdp_queue(struct virtnet_info *vi, int q)
1865 {
1866         if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
1867                 return false;
1868         else if (q < vi->curr_queue_pairs)
1869                 return true;
1870         else
1871                 return false;
1872 }
1873
1874 static void free_unused_bufs(struct virtnet_info *vi)
1875 {
1876         void *buf;
1877         int i;
1878
1879         for (i = 0; i < vi->max_queue_pairs; i++) {
1880                 struct virtqueue *vq = vi->sq[i].vq;
1881                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1882                         if (!is_xdp_queue(vi, i))
1883                                 dev_kfree_skb(buf);
1884                         else
1885                                 put_page(virt_to_head_page(buf));
1886                 }
1887         }
1888
1889         for (i = 0; i < vi->max_queue_pairs; i++) {
1890                 struct virtqueue *vq = vi->rq[i].vq;
1891
1892                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1893                         if (vi->mergeable_rx_bufs) {
1894                                 unsigned long ctx = (unsigned long)buf;
1895                                 void *base = mergeable_ctx_to_buf_address(ctx);
1896                                 put_page(virt_to_head_page(base));
1897                         } else if (vi->big_packets) {
1898                                 give_pages(&vi->rq[i], buf);
1899                         } else {
1900                                 dev_kfree_skb(buf);
1901                         }
1902                 }
1903         }
1904 }
1905
1906 static void virtnet_del_vqs(struct virtnet_info *vi)
1907 {
1908         struct virtio_device *vdev = vi->vdev;
1909
1910         virtnet_clean_affinity(vi, -1);
1911
1912         vdev->config->del_vqs(vdev);
1913
1914         virtnet_free_queues(vi);
1915 }
1916
1917 static int virtnet_find_vqs(struct virtnet_info *vi)
1918 {
1919         vq_callback_t **callbacks;
1920         struct virtqueue **vqs;
1921         int ret = -ENOMEM;
1922         int i, total_vqs;
1923         const char **names;
1924
1925         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1926          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1927          * possible control vq.
1928          */
1929         total_vqs = vi->max_queue_pairs * 2 +
1930                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1931
1932         /* Allocate space for find_vqs parameters */
1933         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1934         if (!vqs)
1935                 goto err_vq;
1936         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1937         if (!callbacks)
1938                 goto err_callback;
1939         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1940         if (!names)
1941                 goto err_names;
1942
1943         /* Parameters for control virtqueue, if any */
1944         if (vi->has_cvq) {
1945                 callbacks[total_vqs - 1] = NULL;
1946                 names[total_vqs - 1] = "control";
1947         }
1948
1949         /* Allocate/initialize parameters for send/receive virtqueues */
1950         for (i = 0; i < vi->max_queue_pairs; i++) {
1951                 callbacks[rxq2vq(i)] = skb_recv_done;
1952                 callbacks[txq2vq(i)] = skb_xmit_done;
1953                 sprintf(vi->rq[i].name, "input.%d", i);
1954                 sprintf(vi->sq[i].name, "output.%d", i);
1955                 names[rxq2vq(i)] = vi->rq[i].name;
1956                 names[txq2vq(i)] = vi->sq[i].name;
1957         }
1958
1959         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1960                                          names);
1961         if (ret)
1962                 goto err_find;
1963
1964         if (vi->has_cvq) {
1965                 vi->cvq = vqs[total_vqs - 1];
1966                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1967                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1968         }
1969
1970         for (i = 0; i < vi->max_queue_pairs; i++) {
1971                 vi->rq[i].vq = vqs[rxq2vq(i)];
1972                 vi->sq[i].vq = vqs[txq2vq(i)];
1973         }
1974
1975         kfree(names);
1976         kfree(callbacks);
1977         kfree(vqs);
1978
1979         return 0;
1980
1981 err_find:
1982         kfree(names);
1983 err_names:
1984         kfree(callbacks);
1985 err_callback:
1986         kfree(vqs);
1987 err_vq:
1988         return ret;
1989 }
1990
1991 static int virtnet_alloc_queues(struct virtnet_info *vi)
1992 {
1993         int i;
1994
1995         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1996         if (!vi->sq)
1997                 goto err_sq;
1998         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1999         if (!vi->rq)
2000                 goto err_rq;
2001
2002         INIT_DELAYED_WORK(&vi->refill, refill_work);
2003         for (i = 0; i < vi->max_queue_pairs; i++) {
2004                 vi->rq[i].pages = NULL;
2005                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2006                                napi_weight);
2007
2008                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2009                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2010                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2011         }
2012
2013         return 0;
2014
2015 err_rq:
2016         kfree(vi->sq);
2017 err_sq:
2018         return -ENOMEM;
2019 }
2020
2021 static int init_vqs(struct virtnet_info *vi)
2022 {
2023         int ret;
2024
2025         /* Allocate send & receive queues */
2026         ret = virtnet_alloc_queues(vi);
2027         if (ret)
2028                 goto err;
2029
2030         ret = virtnet_find_vqs(vi);
2031         if (ret)
2032                 goto err_free;
2033
2034         get_online_cpus();
2035         virtnet_set_affinity(vi);
2036         put_online_cpus();
2037
2038         return 0;
2039
2040 err_free:
2041         virtnet_free_queues(vi);
2042 err:
2043         return ret;
2044 }
2045
2046 #ifdef CONFIG_SYSFS
2047 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2048                 struct rx_queue_attribute *attribute, char *buf)
2049 {
2050         struct virtnet_info *vi = netdev_priv(queue->dev);
2051         unsigned int queue_index = get_netdev_rx_queue_index(queue);
2052         struct ewma_pkt_len *avg;
2053
2054         BUG_ON(queue_index >= vi->max_queue_pairs);
2055         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2056         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
2057 }
2058
2059 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2060         __ATTR_RO(mergeable_rx_buffer_size);
2061
2062 static struct attribute *virtio_net_mrg_rx_attrs[] = {
2063         &mergeable_rx_buffer_size_attribute.attr,
2064         NULL
2065 };
2066
2067 static const struct attribute_group virtio_net_mrg_rx_group = {
2068         .name = "virtio_net",
2069         .attrs = virtio_net_mrg_rx_attrs
2070 };
2071 #endif
2072
2073 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2074                                     unsigned int fbit,
2075                                     const char *fname, const char *dname)
2076 {
2077         if (!virtio_has_feature(vdev, fbit))
2078                 return false;
2079
2080         dev_err(&vdev->dev, "device advertises feature %s but not %s",
2081                 fname, dname);
2082
2083         return true;
2084 }
2085
2086 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
2087         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2088
2089 static bool virtnet_validate_features(struct virtio_device *vdev)
2090 {
2091         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2092             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2093                              "VIRTIO_NET_F_CTRL_VQ") ||
2094              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2095                              "VIRTIO_NET_F_CTRL_VQ") ||
2096              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2097                              "VIRTIO_NET_F_CTRL_VQ") ||
2098              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2099              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2100                              "VIRTIO_NET_F_CTRL_VQ"))) {
2101                 return false;
2102         }
2103
2104         return true;
2105 }
2106
2107 #define MIN_MTU ETH_MIN_MTU
2108 #define MAX_MTU ETH_MAX_MTU
2109
2110 static int virtnet_probe(struct virtio_device *vdev)
2111 {
2112         int i, err;
2113         struct net_device *dev;
2114         struct virtnet_info *vi;
2115         u16 max_queue_pairs;
2116         int mtu;
2117
2118         if (!vdev->config->get) {
2119                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2120                         __func__);
2121                 return -EINVAL;
2122         }
2123
2124         if (!virtnet_validate_features(vdev))
2125                 return -EINVAL;
2126
2127         /* Find if host supports multiqueue virtio_net device */
2128         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2129                                    struct virtio_net_config,
2130                                    max_virtqueue_pairs, &max_queue_pairs);
2131
2132         /* We need at least 2 queue's */
2133         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
2134             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
2135             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2136                 max_queue_pairs = 1;
2137
2138         /* Allocate ourselves a network device with room for our info */
2139         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
2140         if (!dev)
2141                 return -ENOMEM;
2142
2143         /* Set up network device as normal. */
2144         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
2145         dev->netdev_ops = &virtnet_netdev;
2146         dev->features = NETIF_F_HIGHDMA;
2147
2148         dev->ethtool_ops = &virtnet_ethtool_ops;
2149         SET_NETDEV_DEV(dev, &vdev->dev);
2150
2151         /* Do we support "hardware" checksums? */
2152         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
2153                 /* This opens up the world of extra features. */
2154                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2155                 if (csum)
2156                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2157
2158                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
2159                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
2160                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
2161                 }
2162                 /* Individual feature bits: what can host handle? */
2163                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
2164                         dev->hw_features |= NETIF_F_TSO;
2165                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
2166                         dev->hw_features |= NETIF_F_TSO6;
2167                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
2168                         dev->hw_features |= NETIF_F_TSO_ECN;
2169                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
2170                         dev->hw_features |= NETIF_F_UFO;
2171
2172                 dev->features |= NETIF_F_GSO_ROBUST;
2173
2174                 if (gso)
2175                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
2176                 /* (!csum && gso) case will be fixed by register_netdev() */
2177         }
2178         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
2179                 dev->features |= NETIF_F_RXCSUM;
2180
2181         dev->vlan_features = dev->features;
2182
2183         /* MTU range: 68 - 65535 */
2184         dev->min_mtu = MIN_MTU;
2185         dev->max_mtu = MAX_MTU;
2186
2187         /* Configuration may specify what MAC to use.  Otherwise random. */
2188         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
2189                 virtio_cread_bytes(vdev,
2190                                    offsetof(struct virtio_net_config, mac),
2191                                    dev->dev_addr, dev->addr_len);
2192         else
2193                 eth_hw_addr_random(dev);
2194
2195         /* Set up our device-specific information */
2196         vi = netdev_priv(dev);
2197         vi->dev = dev;
2198         vi->vdev = vdev;
2199         vdev->priv = vi;
2200         vi->stats = alloc_percpu(struct virtnet_stats);
2201         err = -ENOMEM;
2202         if (vi->stats == NULL)
2203                 goto free;
2204
2205         for_each_possible_cpu(i) {
2206                 struct virtnet_stats *virtnet_stats;
2207                 virtnet_stats = per_cpu_ptr(vi->stats, i);
2208                 u64_stats_init(&virtnet_stats->tx_syncp);
2209                 u64_stats_init(&virtnet_stats->rx_syncp);
2210         }
2211
2212         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
2213
2214         /* If we can receive ANY GSO packets, we must allocate large ones. */
2215         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2216             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2217             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
2218             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
2219                 vi->big_packets = true;
2220
2221         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
2222                 vi->mergeable_rx_bufs = true;
2223
2224         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
2225             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2226                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2227         else
2228                 vi->hdr_len = sizeof(struct virtio_net_hdr);
2229
2230         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
2231             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2232                 vi->any_header_sg = true;
2233
2234         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2235                 vi->has_cvq = true;
2236
2237         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2238                 mtu = virtio_cread16(vdev,
2239                                      offsetof(struct virtio_net_config,
2240                                               mtu));
2241                 if (mtu < dev->min_mtu) {
2242                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2243                 } else {
2244                         dev->mtu = mtu;
2245                         dev->max_mtu = mtu;
2246                 }
2247         }
2248
2249         if (vi->any_header_sg)
2250                 dev->needed_headroom = vi->hdr_len;
2251
2252         /* Enable multiqueue by default */
2253         if (num_online_cpus() >= max_queue_pairs)
2254                 vi->curr_queue_pairs = max_queue_pairs;
2255         else
2256                 vi->curr_queue_pairs = num_online_cpus();
2257         vi->max_queue_pairs = max_queue_pairs;
2258
2259         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
2260         err = init_vqs(vi);
2261         if (err)
2262                 goto free_stats;
2263
2264 #ifdef CONFIG_SYSFS
2265         if (vi->mergeable_rx_bufs)
2266                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
2267 #endif
2268         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
2269         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
2270
2271         virtnet_init_settings(dev);
2272
2273         err = register_netdev(dev);
2274         if (err) {
2275                 pr_debug("virtio_net: registering device failed\n");
2276                 goto free_vqs;
2277         }
2278
2279         virtio_device_ready(vdev);
2280
2281         err = virtnet_cpu_notif_add(vi);
2282         if (err) {
2283                 pr_debug("virtio_net: registering cpu notifier failed\n");
2284                 goto free_unregister_netdev;
2285         }
2286
2287         rtnl_lock();
2288         virtnet_set_queues(vi, vi->curr_queue_pairs);
2289         rtnl_unlock();
2290
2291         /* Assume link up if device can't report link status,
2292            otherwise get link status from config. */
2293         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
2294                 netif_carrier_off(dev);
2295                 schedule_work(&vi->config_work);
2296         } else {
2297                 vi->status = VIRTIO_NET_S_LINK_UP;
2298                 netif_carrier_on(dev);
2299         }
2300
2301         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
2302                  dev->name, max_queue_pairs);
2303
2304         return 0;
2305
2306 free_unregister_netdev:
2307         vi->vdev->config->reset(vdev);
2308
2309         unregister_netdev(dev);
2310 free_vqs:
2311         cancel_delayed_work_sync(&vi->refill);
2312         free_receive_page_frags(vi);
2313         virtnet_del_vqs(vi);
2314 free_stats:
2315         free_percpu(vi->stats);
2316 free:
2317         free_netdev(dev);
2318         return err;
2319 }
2320
2321 static void remove_vq_common(struct virtnet_info *vi)
2322 {
2323         vi->vdev->config->reset(vi->vdev);
2324
2325         /* Free unused buffers in both send and recv, if any. */
2326         free_unused_bufs(vi);
2327
2328         free_receive_bufs(vi);
2329
2330         free_receive_page_frags(vi);
2331
2332         virtnet_del_vqs(vi);
2333 }
2334
2335 static void virtnet_remove(struct virtio_device *vdev)
2336 {
2337         struct virtnet_info *vi = vdev->priv;
2338
2339         virtnet_cpu_notif_remove(vi);
2340
2341         /* Make sure no work handler is accessing the device. */
2342         flush_work(&vi->config_work);
2343
2344         unregister_netdev(vi->dev);
2345
2346         remove_vq_common(vi);
2347
2348         free_percpu(vi->stats);
2349         free_netdev(vi->dev);
2350 }
2351
2352 #ifdef CONFIG_PM_SLEEP
2353 static int virtnet_freeze(struct virtio_device *vdev)
2354 {
2355         struct virtnet_info *vi = vdev->priv;
2356         int i;
2357
2358         virtnet_cpu_notif_remove(vi);
2359
2360         /* Make sure no work handler is accessing the device */
2361         flush_work(&vi->config_work);
2362
2363         netif_device_detach(vi->dev);
2364         cancel_delayed_work_sync(&vi->refill);
2365
2366         if (netif_running(vi->dev)) {
2367                 for (i = 0; i < vi->max_queue_pairs; i++)
2368                         napi_disable(&vi->rq[i].napi);
2369         }
2370
2371         remove_vq_common(vi);
2372
2373         return 0;
2374 }
2375
2376 static int virtnet_restore(struct virtio_device *vdev)
2377 {
2378         struct virtnet_info *vi = vdev->priv;
2379         int err, i;
2380
2381         err = init_vqs(vi);
2382         if (err)
2383                 return err;
2384
2385         virtio_device_ready(vdev);
2386
2387         if (netif_running(vi->dev)) {
2388                 for (i = 0; i < vi->curr_queue_pairs; i++)
2389                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2390                                 schedule_delayed_work(&vi->refill, 0);
2391
2392                 for (i = 0; i < vi->max_queue_pairs; i++)
2393                         virtnet_napi_enable(&vi->rq[i]);
2394         }
2395
2396         netif_device_attach(vi->dev);
2397
2398         rtnl_lock();
2399         virtnet_set_queues(vi, vi->curr_queue_pairs);
2400         rtnl_unlock();
2401
2402         err = virtnet_cpu_notif_add(vi);
2403         if (err)
2404                 return err;
2405
2406         return 0;
2407 }
2408 #endif
2409
2410 static struct virtio_device_id id_table[] = {
2411         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2412         { 0 },
2413 };
2414
2415 #define VIRTNET_FEATURES \
2416         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
2417         VIRTIO_NET_F_MAC, \
2418         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
2419         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
2420         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
2421         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
2422         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
2423         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
2424         VIRTIO_NET_F_CTRL_MAC_ADDR, \
2425         VIRTIO_NET_F_MTU
2426
2427 static unsigned int features[] = {
2428         VIRTNET_FEATURES,
2429 };
2430
2431 static unsigned int features_legacy[] = {
2432         VIRTNET_FEATURES,
2433         VIRTIO_NET_F_GSO,
2434         VIRTIO_F_ANY_LAYOUT,
2435 };
2436
2437 static struct virtio_driver virtio_net_driver = {
2438         .feature_table = features,
2439         .feature_table_size = ARRAY_SIZE(features),
2440         .feature_table_legacy = features_legacy,
2441         .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
2442         .driver.name =  KBUILD_MODNAME,
2443         .driver.owner = THIS_MODULE,
2444         .id_table =     id_table,
2445         .probe =        virtnet_probe,
2446         .remove =       virtnet_remove,
2447         .config_changed = virtnet_config_changed,
2448 #ifdef CONFIG_PM_SLEEP
2449         .freeze =       virtnet_freeze,
2450         .restore =      virtnet_restore,
2451 #endif
2452 };
2453
2454 static __init int virtio_net_driver_init(void)
2455 {
2456         int ret;
2457
2458         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "AP_VIRT_NET_ONLINE",
2459                                       virtnet_cpu_online,
2460                                       virtnet_cpu_down_prep);
2461         if (ret < 0)
2462                 goto out;
2463         virtionet_online = ret;
2464         ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "VIRT_NET_DEAD",
2465                                       NULL, virtnet_cpu_dead);
2466         if (ret)
2467                 goto err_dead;
2468
2469         ret = register_virtio_driver(&virtio_net_driver);
2470         if (ret)
2471                 goto err_virtio;
2472         return 0;
2473 err_virtio:
2474         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2475 err_dead:
2476         cpuhp_remove_multi_state(virtionet_online);
2477 out:
2478         return ret;
2479 }
2480 module_init(virtio_net_driver_init);
2481
2482 static __exit void virtio_net_driver_exit(void)
2483 {
2484         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2485         cpuhp_remove_multi_state(virtionet_online);
2486         unregister_virtio_driver(&virtio_net_driver);
2487 }
2488 module_exit(virtio_net_driver_exit);
2489
2490 MODULE_DEVICE_TABLE(virtio, id_table);
2491 MODULE_DESCRIPTION("Virtio network driver");
2492 MODULE_LICENSE("GPL");