drivers/net/virtio_net.c

   1 /* A network driver using virtio.
   2  *
   3  * Copyright 2007 Rusty Russell <[email protected]> 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/bpf_trace.h>
  27 #include <linux/scatterlist.h>
  28 #include <linux/if_vlan.h>
  29 #include <linux/slab.h>
  30 #include <linux/cpu.h>
  31 #include <linux/average.h>
  32 #include <linux/filter.h>
  33 #include <linux/kernel.h>
  34 #include <linux/pci.h>
  35 #include <net/route.h>
  36 #include <net/xdp.h>
  37 #include <net/net_failover.h>
  38
  39 static int napi_weight = NAPI_POLL_WEIGHT;
  40 module_param(napi_weight, int, 0444);
  41
  42 static bool csum = true, gso = true, napi_tx;
  43 module_param(csum, bool, 0444);
  44 module_param(gso, bool, 0444);
  45 module_param(napi_tx, bool, 0644);
  46
  47 /* FIXME: MTU in config. */
  48 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  49 #define GOOD_COPY_LEN   128
  50
  51 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
  52
  53 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
  54 #define VIRTIO_XDP_HEADROOM 256
  55
  56 /* Separating two types of XDP xmit */
  57 #define VIRTIO_XDP_TX           BIT(0)
  58 #define VIRTIO_XDP_REDIR        BIT(1)
  59
  60 /* RX packet size EWMA. The average packet size is used to determine the packet
  61  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  62  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  63  * term, transient changes in packet size.
  64  */
  65 DECLARE_EWMA(pkt_len, 0, 64)
  66
  67 #define VIRTNET_DRIVER_VERSION "1.0.0"
  68
  69 static const unsigned long guest_offloads[] = {
  70         VIRTIO_NET_F_GUEST_TSO4,
  71         VIRTIO_NET_F_GUEST_TSO6,
  72         VIRTIO_NET_F_GUEST_ECN,
  73         VIRTIO_NET_F_GUEST_UFO,
  74         VIRTIO_NET_F_GUEST_CSUM
  75 };
  76
  77 struct virtnet_stat_desc {
  78         char desc[ETH_GSTRING_LEN];
  79         size_t offset;
  80 };
  81
  82 struct virtnet_sq_stats {
  83         struct u64_stats_sync syncp;
  84         u64 packets;
  85         u64 bytes;
  86         u64 xdp_tx;
  87         u64 xdp_tx_drops;
  88         u64 kicks;
  89 };
  90
  91 struct virtnet_rq_stats {
  92         struct u64_stats_sync syncp;
  93         u64 packets;
  94         u64 bytes;
  95         u64 drops;
  96         u64 xdp_packets;
  97         u64 xdp_tx;
  98         u64 xdp_redirects;
  99         u64 xdp_drops;
 100         u64 kicks;
 101 };
 102
 103 #define VIRTNET_SQ_STAT(m)      offsetof(struct virtnet_sq_stats, m)
 104 #define VIRTNET_RQ_STAT(m)      offsetof(struct virtnet_rq_stats, m)
 105
 106 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
 107         { "packets",            VIRTNET_SQ_STAT(packets) },
 108         { "bytes",              VIRTNET_SQ_STAT(bytes) },
 109         { "xdp_tx",             VIRTNET_SQ_STAT(xdp_tx) },
 110         { "xdp_tx_drops",       VIRTNET_SQ_STAT(xdp_tx_drops) },
 111         { "kicks",              VIRTNET_SQ_STAT(kicks) },
 112 };
 113
 114 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
 115         { "packets",            VIRTNET_RQ_STAT(packets) },
 116         { "bytes",              VIRTNET_RQ_STAT(bytes) },
 117         { "drops",              VIRTNET_RQ_STAT(drops) },
 118         { "xdp_packets",        VIRTNET_RQ_STAT(xdp_packets) },
 119         { "xdp_tx",             VIRTNET_RQ_STAT(xdp_tx) },
 120         { "xdp_redirects",      VIRTNET_RQ_STAT(xdp_redirects) },
 121         { "xdp_drops",          VIRTNET_RQ_STAT(xdp_drops) },
 122         { "kicks",              VIRTNET_RQ_STAT(kicks) },
 123 };
 124
 125 #define VIRTNET_SQ_STATS_LEN    ARRAY_SIZE(virtnet_sq_stats_desc)
 126 #define VIRTNET_RQ_STATS_LEN    ARRAY_SIZE(virtnet_rq_stats_desc)
 127
 128 /* Internal representation of a send virtqueue */
 129 struct send_queue {
 130         /* Virtqueue associated with this send _queue */
 131         struct virtqueue *vq;
 132
 133         /* TX: fragments + linear part + virtio header */
 134         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 135
 136         /* Name of the send queue: output.$index */
 137         char name[40];
 138
 139         struct virtnet_sq_stats stats;
 140
 141         struct napi_struct napi;
 142 };
 143
 144 /* Internal representation of a receive virtqueue */
 145 struct receive_queue {
 146         /* Virtqueue associated with this receive_queue */
 147         struct virtqueue *vq;
 148
 149         struct napi_struct napi;
 150
 151         struct bpf_prog __rcu *xdp_prog;
 152
 153         struct virtnet_rq_stats stats;
 154
 155         /* Chain pages by the private ptr. */
 156         struct page *pages;
 157
 158         /* Average packet length for mergeable receive buffers. */
 159         struct ewma_pkt_len mrg_avg_pkt_len;
 160
 161         /* Page frag for packet buffer allocation. */
 162         struct page_frag alloc_frag;
 163
 164         /* RX: fragments + linear part + virtio header */
 165         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 166
 167         /* Min single buffer size for mergeable buffers case. */
 168         unsigned int min_buf_len;
 169
 170         /* Name of this receive queue: input.$index */
 171         char name[40];
 172
 173         struct xdp_rxq_info xdp_rxq;
 174 };
 175
 176 /* Control VQ buffers: protected by the rtnl lock */
 177 struct control_buf {
 178         struct virtio_net_ctrl_hdr hdr;
 179         virtio_net_ctrl_ack status;
 180         struct virtio_net_ctrl_mq mq;
 181         u8 promisc;
 182         u8 allmulti;
 183         __virtio16 vid;
 184         __virtio64 offloads;
 185 };
 186
 187 struct virtnet_info {
 188         struct virtio_device *vdev;
 189         struct virtqueue *cvq;
 190         struct net_device *dev;
 191         struct send_queue *sq;
 192         struct receive_queue *rq;
 193         unsigned int status;
 194
 195         /* Max # of queue pairs supported by the device */
 196         u16 max_queue_pairs;
 197
 198         /* # of queue pairs currently used by the driver */
 199         u16 curr_queue_pairs;
 200
 201         /* # of XDP queue pairs currently used by the driver */
 202         u16 xdp_queue_pairs;
 203
 204         /* I like... big packets and I cannot lie! */
 205         bool big_packets;
 206
 207         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 208         bool mergeable_rx_bufs;
 209
 210         /* Has control virtqueue */
 211         bool has_cvq;
 212
 213         /* Host can handle any s/g split between our header and packet data */
 214         bool any_header_sg;
 215
 216         /* Packet virtio header size */
 217         u8 hdr_len;
 218
 219         /* Work struct for refilling if we run low on memory. */
 220         struct delayed_work refill;
 221
 222         /* Work struct for config space updates */
 223         struct work_struct config_work;
 224
 225         /* Does the affinity hint is set for virtqueues? */
 226         bool affinity_hint_set;
 227
 228         /* CPU hotplug instances for online & dead */
 229         struct hlist_node node;
 230         struct hlist_node node_dead;
 231
 232         struct control_buf *ctrl;
 233
 234         /* Ethtool settings */
 235         u8 duplex;
 236         u32 speed;
 237
 238         unsigned long guest_offloads;
 239
 240         /* failover when STANDBY feature enabled */
 241         struct failover *failover;
 242 };
 243
 244 struct padded_vnet_hdr {
 245         struct virtio_net_hdr_mrg_rxbuf hdr;
 246         /*
 247          * hdr is in a separate sg buffer, and data sg buffer shares same page
 248          * with this header sg. This padding makes next sg 16 byte aligned
 249          * after the header.
 250          */
 251         char padding[4];
 252 };
 253
 254 /* Converting between virtqueue no. and kernel tx/rx queue no.
 255  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 256  */
 257 static int vq2txq(struct virtqueue *vq)
 258 {
 259         return (vq->index - 1) / 2;
 260 }
 261
 262 static int txq2vq(int txq)
 263 {
 264         return txq * 2 + 1;
 265 }
 266
 267 static int vq2rxq(struct virtqueue *vq)
 268 {
 269         return vq->index / 2;
 270 }
 271
 272 static int rxq2vq(int rxq)
 273 {
 274         return rxq * 2;
 275 }
 276
 277 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 278 {
 279         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 280 }
 281
 282 /*
 283  * private is used to chain pages for big packets, put the whole
 284  * most recent used list in the beginning for reuse
 285  */
 286 static void give_pages(struct receive_queue *rq, struct page *page)
 287 {
 288         struct page *end;
 289
 290         /* Find end of list, sew whole thing into vi->rq.pages. */
 291         for (end = page; end->private; end = (struct page *)end->private);
 292         end->private = (unsigned long)rq->pages;
 293         rq->pages = page;
 294 }
 295
 296 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 297 {
 298         struct page *p = rq->pages;
 299
 300         if (p) {
 301                 rq->pages = (struct page *)p->private;
 302                 /* clear private here, it is used to chain pages */
 303                 p->private = 0;
 304         } else
 305                 p = alloc_page(gfp_mask);
 306         return p;
 307 }
 308
 309 static void virtqueue_napi_schedule(struct napi_struct *napi,
 310                                     struct virtqueue *vq)
 311 {
 312         if (napi_schedule_prep(napi)) {
 313                 virtqueue_disable_cb(vq);
 314                 __napi_schedule(napi);
 315         }
 316 }
 317
 318 static void virtqueue_napi_complete(struct napi_struct *napi,
 319                                     struct virtqueue *vq, int processed)
 320 {
 321         int opaque;
 322
 323         opaque = virtqueue_enable_cb_prepare(vq);
 324         if (napi_complete_done(napi, processed)) {
 325                 if (unlikely(virtqueue_poll(vq, opaque)))
 326                         virtqueue_napi_schedule(napi, vq);
 327         } else {
 328                 virtqueue_disable_cb(vq);
 329         }
 330 }
 331
 332 static void skb_xmit_done(struct virtqueue *vq)
 333 {
 334         struct virtnet_info *vi = vq->vdev->priv;
 335         struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
 336
 337         /* Suppress further interrupts. */
 338         virtqueue_disable_cb(vq);
 339
 340         if (napi->weight)
 341                 virtqueue_napi_schedule(napi, vq);
 342         else
 343                 /* We were probably waiting for more output buffers. */
 344                 netif_wake_subqueue(vi->dev, vq2txq(vq));
 345 }
 346
 347 #define MRG_CTX_HEADER_SHIFT 22
 348 static void *mergeable_len_to_ctx(unsigned int truesize,
 349                                   unsigned int headroom)
 350 {
 351         return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
 352 }
 353
 354 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
 355 {
 356         return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
 357 }
 358
 359 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
 360 {
 361         return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
 362 }
 363
 364 /* Called from bottom half context */
 365 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 366                                    struct receive_queue *rq,
 367                                    struct page *page, unsigned int offset,
 368                                    unsigned int len, unsigned int truesize)
 369 {
 370         struct sk_buff *skb;
 371         struct virtio_net_hdr_mrg_rxbuf *hdr;
 372         unsigned int copy, hdr_len, hdr_padded_len;
 373         char *p;
 374
 375         p = page_address(page) + offset;
 376
 377         /* copy small packet so we can reuse these pages for small data */
 378         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 379         if (unlikely(!skb))
 380                 return NULL;
 381
 382         hdr = skb_vnet_hdr(skb);
 383
 384         hdr_len = vi->hdr_len;
 385         if (vi->mergeable_rx_bufs)
 386                 hdr_padded_len = sizeof(*hdr);
 387         else
 388                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 389
 390         memcpy(hdr, p, hdr_len);
 391
 392         len -= hdr_len;
 393         offset += hdr_padded_len;
 394         p += hdr_padded_len;
 395
 396         copy = len;
 397         if (copy > skb_tailroom(skb))
 398                 copy = skb_tailroom(skb);
 399         skb_put_data(skb, p, copy);
 400
 401         len -= copy;
 402         offset += copy;
 403
 404         if (vi->mergeable_rx_bufs) {
 405                 if (len)
 406                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 407                 else
 408                         put_page(page);
 409                 return skb;
 410         }
 411
 412         /*
 413          * Verify that we can indeed put this data into a skb.
 414          * This is here to handle cases when the device erroneously
 415          * tries to receive more than is possible. This is usually
 416          * the case of a broken device.
 417          */
 418         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 419                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 420                 dev_kfree_skb(skb);
 421                 return NULL;
 422         }
 423         BUG_ON(offset >= PAGE_SIZE);
 424         while (len) {
 425                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 426                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 427                                 frag_size, truesize);
 428                 len -= frag_size;
 429                 page = (struct page *)page->private;
 430                 offset = 0;
 431         }
 432
 433         if (page)
 434                 give_pages(rq, page);
 435
 436         return skb;
 437 }
 438
 439 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
 440                                    struct send_queue *sq,
 441                                    struct xdp_frame *xdpf)
 442 {
 443         struct virtio_net_hdr_mrg_rxbuf *hdr;
 444         int err;
 445
 446         /* virtqueue want to use data area in-front of packet */
 447         if (unlikely(xdpf->metasize > 0))
 448                 return -EOPNOTSUPP;
 449
 450         if (unlikely(xdpf->headroom < vi->hdr_len))
 451                 return -EOVERFLOW;
 452
 453         /* Make room for virtqueue hdr (also change xdpf->headroom?) */
 454         xdpf->data -= vi->hdr_len;
 455         /* Zero header and leave csum up to XDP layers */
 456         hdr = xdpf->data;
 457         memset(hdr, 0, vi->hdr_len);
 458         xdpf->len   += vi->hdr_len;
 459
 460         sg_init_one(sq->sg, xdpf->data, xdpf->len);
 461
 462         err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdpf, GFP_ATOMIC);
 463         if (unlikely(err))
 464                 return -ENOSPC; /* Caller handle free/refcnt */
 465
 466         return 0;
 467 }
 468
 469 static struct send_queue *virtnet_xdp_sq(struct virtnet_info *vi)
 470 {
 471         unsigned int qp;
 472
 473         qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
 474         return &vi->sq[qp];
 475 }
 476
 477 static int virtnet_xdp_xmit(struct net_device *dev,
 478                             int n, struct xdp_frame **frames, u32 flags)
 479 {
 480         struct virtnet_info *vi = netdev_priv(dev);
 481         struct receive_queue *rq = vi->rq;
 482         struct xdp_frame *xdpf_sent;
 483         struct bpf_prog *xdp_prog;
 484         struct send_queue *sq;
 485         unsigned int len;
 486         int drops = 0;
 487         int kicks = 0;
 488         int ret, err;
 489         int i;
 490
 491         sq = virtnet_xdp_sq(vi);
 492
 493         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
 494                 ret = -EINVAL;
 495                 drops = n;
 496                 goto out;
 497         }
 498
 499         /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
 500          * indicate XDP resources have been successfully allocated.
 501          */
 502         xdp_prog = rcu_dereference(rq->xdp_prog);
 503         if (!xdp_prog) {
 504                 ret = -ENXIO;
 505                 drops = n;
 506                 goto out;
 507         }
 508
 509         /* Free up any pending old buffers before queueing new ones. */
 510         while ((xdpf_sent = virtqueue_get_buf(sq->vq, &len)) != NULL)
 511                 xdp_return_frame(xdpf_sent);
 512
 513         for (i = 0; i < n; i++) {
 514                 struct xdp_frame *xdpf = frames[i];
 515
 516                 err = __virtnet_xdp_xmit_one(vi, sq, xdpf);
 517                 if (err) {
 518                         xdp_return_frame_rx_napi(xdpf);
 519                         drops++;
 520                 }
 521         }
 522         ret = n - drops;
 523
 524         if (flags & XDP_XMIT_FLUSH) {
 525                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
 526                         kicks = 1;
 527         }
 528 out:
 529         u64_stats_update_begin(&sq->stats.syncp);
 530         sq->stats.xdp_tx += n;
 531         sq->stats.xdp_tx_drops += drops;
 532         sq->stats.kicks += kicks;
 533         u64_stats_update_end(&sq->stats.syncp);
 534
 535         return ret;
 536 }
 537
 538 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
 539 {
 540         return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
 541 }
 542
 543 /* We copy the packet for XDP in the following cases:
 544  *
 545  * 1) Packet is scattered across multiple rx buffers.
 546  * 2) Headroom space is insufficient.
 547  *
 548  * This is inefficient but it's a temporary condition that
 549  * we hit right after XDP is enabled and until queue is refilled
 550  * with large buffers with sufficient headroom - so it should affect
 551  * at most queue size packets.
 552  * Afterwards, the conditions to enable
 553  * XDP should preclude the underlying device from sending packets
 554  * across multiple buffers (num_buf > 1), and we make sure buffers
 555  * have enough headroom.
 556  */
 557 static struct page *xdp_linearize_page(struct receive_queue *rq,
 558                                        u16 *num_buf,
 559                                        struct page *p,
 560                                        int offset,
 561                                        int page_off,
 562                                        unsigned int *len)
 563 {
 564         struct page *page = alloc_page(GFP_ATOMIC);
 565
 566         if (!page)
 567                 return NULL;
 568
 569         memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
 570         page_off += *len;
 571
 572         while (--*num_buf) {
 573                 int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 574                 unsigned int buflen;
 575                 void *buf;
 576                 int off;
 577
 578                 buf = virtqueue_get_buf(rq->vq, &buflen);
 579                 if (unlikely(!buf))
 580                         goto err_buf;
 581
 582                 p = virt_to_head_page(buf);
 583                 off = buf - page_address(p);
 584
 585                 /* guard against a misconfigured or uncooperative backend that
 586                  * is sending packet larger than the MTU.
 587                  */
 588                 if ((page_off + buflen + tailroom) > PAGE_SIZE) {
 589                         put_page(p);
 590                         goto err_buf;
 591                 }
 592
 593                 memcpy(page_address(page) + page_off,
 594                        page_address(p) + off, buflen);
 595                 page_off += buflen;
 596                 put_page(p);
 597         }
 598
 599         /* Headroom does not contribute to packet length */
 600         *len = page_off - VIRTIO_XDP_HEADROOM;
 601         return page;
 602 err_buf:
 603         __free_pages(page, 0);
 604         return NULL;
 605 }
 606
 607 static struct sk_buff *receive_small(struct net_device *dev,
 608                                      struct virtnet_info *vi,
 609                                      struct receive_queue *rq,
 610                                      void *buf, void *ctx,
 611                                      unsigned int len,
 612                                      unsigned int *xdp_xmit,
 613                                      struct virtnet_rq_stats *stats)
 614 {
 615         struct sk_buff *skb;
 616         struct bpf_prog *xdp_prog;
 617         unsigned int xdp_headroom = (unsigned long)ctx;
 618         unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
 619         unsigned int headroom = vi->hdr_len + header_offset;
 620         unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 621                               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 622         struct page *page = virt_to_head_page(buf);
 623         unsigned int delta = 0;
 624         struct page *xdp_page;
 625         int err;
 626
 627         len -= vi->hdr_len;
 628         stats->bytes += len;
 629
 630         rcu_read_lock();
 631         xdp_prog = rcu_dereference(rq->xdp_prog);
 632         if (xdp_prog) {
 633                 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
 634                 struct xdp_frame *xdpf;
 635                 struct xdp_buff xdp;
 636                 void *orig_data;
 637                 u32 act;
 638
 639                 if (unlikely(hdr->hdr.gso_type))
 640                         goto err_xdp;
 641
 642                 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
 643                         int offset = buf - page_address(page) + header_offset;
 644                         unsigned int tlen = len + vi->hdr_len;
 645                         u16 num_buf = 1;
 646
 647                         xdp_headroom = virtnet_get_headroom(vi);
 648                         header_offset = VIRTNET_RX_PAD + xdp_headroom;
 649                         headroom = vi->hdr_len + header_offset;
 650                         buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 651                                  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 652                         xdp_page = xdp_linearize_page(rq, &num_buf, page,
 653                                                       offset, header_offset,
 654                                                       &tlen);
 655                         if (!xdp_page)
 656                                 goto err_xdp;
 657
 658                         buf = page_address(xdp_page);
 659                         put_page(page);
 660                         page = xdp_page;
 661                 }
 662
 663                 xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
 664                 xdp.data = xdp.data_hard_start + xdp_headroom;
 665                 xdp_set_data_meta_invalid(&xdp);
 666                 xdp.data_end = xdp.data + len;
 667                 xdp.rxq = &rq->xdp_rxq;
 668                 orig_data = xdp.data;
 669                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 670                 stats->xdp_packets++;
 671
 672                 switch (act) {
 673                 case XDP_PASS:
 674                         /* Recalculate length in case bpf program changed it */
 675                         delta = orig_data - xdp.data;
 676                         len = xdp.data_end - xdp.data;
 677                         break;
 678                 case XDP_TX:
 679                         stats->xdp_tx++;
 680                         xdpf = convert_to_xdp_frame(&xdp);
 681                         if (unlikely(!xdpf))
 682                                 goto err_xdp;
 683                         err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 684                         if (unlikely(err < 0)) {
 685                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 686                                 goto err_xdp;
 687                         }
 688                         *xdp_xmit |= VIRTIO_XDP_TX;
 689                         rcu_read_unlock();
 690                         goto xdp_xmit;
 691                 case XDP_REDIRECT:
 692                         stats->xdp_redirects++;
 693                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
 694                         if (err)
 695                                 goto err_xdp;
 696                         *xdp_xmit |= VIRTIO_XDP_REDIR;
 697                         rcu_read_unlock();
 698                         goto xdp_xmit;
 699                 default:
 700                         bpf_warn_invalid_xdp_action(act);
 701                         /* fall through */
 702                 case XDP_ABORTED:
 703                         trace_xdp_exception(vi->dev, xdp_prog, act);
 704                 case XDP_DROP:
 705                         goto err_xdp;
 706                 }
 707         }
 708         rcu_read_unlock();
 709
 710         skb = build_skb(buf, buflen);
 711         if (!skb) {
 712                 put_page(page);
 713                 goto err;
 714         }
 715         skb_reserve(skb, headroom - delta);
 716         skb_put(skb, len);
 717         if (!delta) {
 718                 buf += header_offset;
 719                 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
 720         } /* keep zeroed vnet hdr since packet was changed by bpf */
 721
 722 err:
 723         return skb;
 724
 725 err_xdp:
 726         rcu_read_unlock();
 727         stats->xdp_drops++;
 728         stats->drops++;
 729         put_page(page);
 730 xdp_xmit:
 731         return NULL;
 732 }
 733
 734 static struct sk_buff *receive_big(struct net_device *dev,
 735                                    struct virtnet_info *vi,
 736                                    struct receive_queue *rq,
 737                                    void *buf,
 738                                    unsigned int len,
 739                                    struct virtnet_rq_stats *stats)
 740 {
 741         struct page *page = buf;
 742         struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 743
 744         stats->bytes += len - vi->hdr_len;
 745         if (unlikely(!skb))
 746                 goto err;
 747
 748         return skb;
 749
 750 err:
 751         stats->drops++;
 752         give_pages(rq, page);
 753         return NULL;
 754 }
 755
 756 static struct sk_buff *receive_mergeable(struct net_device *dev,
 757                                          struct virtnet_info *vi,
 758                                          struct receive_queue *rq,
 759                                          void *buf,
 760                                          void *ctx,
 761                                          unsigned int len,
 762                                          unsigned int *xdp_xmit,
 763                                          struct virtnet_rq_stats *stats)
 764 {
 765         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 766         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 767         struct page *page = virt_to_head_page(buf);
 768         int offset = buf - page_address(page);
 769         struct sk_buff *head_skb, *curr_skb;
 770         struct bpf_prog *xdp_prog;
 771         unsigned int truesize;
 772         unsigned int headroom = mergeable_ctx_to_headroom(ctx);
 773         int err;
 774
 775         head_skb = NULL;
 776         stats->bytes += len - vi->hdr_len;
 777
 778         rcu_read_lock();
 779         xdp_prog = rcu_dereference(rq->xdp_prog);
 780         if (xdp_prog) {
 781                 struct xdp_frame *xdpf;
 782                 struct page *xdp_page;
 783                 struct xdp_buff xdp;
 784                 void *data;
 785                 u32 act;
 786
 787                 /* Transient failure which in theory could occur if
 788                  * in-flight packets from before XDP was enabled reach
 789                  * the receive path after XDP is loaded.
 790                  */
 791                 if (unlikely(hdr->hdr.gso_type))
 792                         goto err_xdp;
 793
 794                 /* This happens when rx buffer size is underestimated
 795                  * or headroom is not enough because of the buffer
 796                  * was refilled before XDP is set. This should only
 797                  * happen for the first several packets, so we don't
 798                  * care much about its performance.
 799                  */
 800                 if (unlikely(num_buf > 1 ||
 801                              headroom < virtnet_get_headroom(vi))) {
 802                         /* linearize data for XDP */
 803                         xdp_page = xdp_linearize_page(rq, &num_buf,
 804                                                       page, offset,
 805                                                       VIRTIO_XDP_HEADROOM,
 806                                                       &len);
 807                         if (!xdp_page)
 808                                 goto err_xdp;
 809                         offset = VIRTIO_XDP_HEADROOM;
 810                 } else {
 811                         xdp_page = page;
 812                 }
 813
 814                 /* Allow consuming headroom but reserve enough space to push
 815                  * the descriptor on if we get an XDP_TX return code.
 816                  */
 817                 data = page_address(xdp_page) + offset;
 818                 xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
 819                 xdp.data = data + vi->hdr_len;
 820                 xdp_set_data_meta_invalid(&xdp);
 821                 xdp.data_end = xdp.data + (len - vi->hdr_len);
 822                 xdp.rxq = &rq->xdp_rxq;
 823
 824                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 825                 stats->xdp_packets++;
 826
 827                 switch (act) {
 828                 case XDP_PASS:
 829                         /* recalculate offset to account for any header
 830                          * adjustments. Note other cases do not build an
 831                          * skb and avoid using offset
 832                          */
 833                         offset = xdp.data -
 834                                         page_address(xdp_page) - vi->hdr_len;
 835
 836                         /* recalculate len if xdp.data or xdp.data_end were
 837                          * adjusted
 838                          */
 839                         len = xdp.data_end - xdp.data + vi->hdr_len;
 840                         /* We can only create skb based on xdp_page. */
 841                         if (unlikely(xdp_page != page)) {
 842                                 rcu_read_unlock();
 843                                 put_page(page);
 844                                 head_skb = page_to_skb(vi, rq, xdp_page,
 845                                                        offset, len, PAGE_SIZE);
 846                                 return head_skb;
 847                         }
 848                         break;
 849                 case XDP_TX:
 850                         stats->xdp_tx++;
 851                         xdpf = convert_to_xdp_frame(&xdp);
 852                         if (unlikely(!xdpf))
 853                                 goto err_xdp;
 854                         err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 855                         if (unlikely(err < 0)) {
 856                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 857                                 if (unlikely(xdp_page != page))
 858                                         put_page(xdp_page);
 859                                 goto err_xdp;
 860                         }
 861                         *xdp_xmit |= VIRTIO_XDP_TX;
 862                         if (unlikely(xdp_page != page))
 863                                 put_page(page);
 864                         rcu_read_unlock();
 865                         goto xdp_xmit;
 866                 case XDP_REDIRECT:
 867                         stats->xdp_redirects++;
 868                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
 869                         if (err) {
 870                                 if (unlikely(xdp_page != page))
 871                                         put_page(xdp_page);
 872                                 goto err_xdp;
 873                         }
 874                         *xdp_xmit |= VIRTIO_XDP_REDIR;
 875                         if (unlikely(xdp_page != page))
 876                                 put_page(page);
 877                         rcu_read_unlock();
 878                         goto xdp_xmit;
 879                 default:
 880                         bpf_warn_invalid_xdp_action(act);
 881                         /* fall through */
 882                 case XDP_ABORTED:
 883                         trace_xdp_exception(vi->dev, xdp_prog, act);
 884                         /* fall through */
 885                 case XDP_DROP:
 886                         if (unlikely(xdp_page != page))
 887                                 __free_pages(xdp_page, 0);
 888                         goto err_xdp;
 889                 }
 890         }
 891         rcu_read_unlock();
 892
 893         truesize = mergeable_ctx_to_truesize(ctx);
 894         if (unlikely(len > truesize)) {
 895                 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 896                          dev->name, len, (unsigned long)ctx);
 897                 dev->stats.rx_length_errors++;
 898                 goto err_skb;
 899         }
 900
 901         head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
 902         curr_skb = head_skb;
 903
 904         if (unlikely(!curr_skb))
 905                 goto err_skb;
 906         while (--num_buf) {
 907                 int num_skb_frags;
 908
 909                 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
 910                 if (unlikely(!buf)) {
 911                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 912                                  dev->name, num_buf,
 913                                  virtio16_to_cpu(vi->vdev,
 914                                                  hdr->num_buffers));
 915                         dev->stats.rx_length_errors++;
 916                         goto err_buf;
 917                 }
 918
 919                 stats->bytes += len;
 920                 page = virt_to_head_page(buf);
 921
 922                 truesize = mergeable_ctx_to_truesize(ctx);
 923                 if (unlikely(len > truesize)) {
 924                         pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 925                                  dev->name, len, (unsigned long)ctx);
 926                         dev->stats.rx_length_errors++;
 927                         goto err_skb;
 928                 }
 929
 930                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 931                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 932                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 933
 934                         if (unlikely(!nskb))
 935                                 goto err_skb;
 936                         if (curr_skb == head_skb)
 937                                 skb_shinfo(curr_skb)->frag_list = nskb;
 938                         else
 939                                 curr_skb->next = nskb;
 940                         curr_skb = nskb;
 941                         head_skb->truesize += nskb->truesize;
 942                         num_skb_frags = 0;
 943                 }
 944                 if (curr_skb != head_skb) {
 945                         head_skb->data_len += len;
 946                         head_skb->len += len;
 947                         head_skb->truesize += truesize;
 948                 }
 949                 offset = buf - page_address(page);
 950                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 951                         put_page(page);
 952                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 953                                              len, truesize);
 954                 } else {
 955                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 956                                         offset, len, truesize);
 957                 }
 958         }
 959
 960         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
 961         return head_skb;
 962
 963 err_xdp:
 964         rcu_read_unlock();
 965         stats->xdp_drops++;
 966 err_skb:
 967         put_page(page);
 968         while (num_buf-- > 1) {
 969                 buf = virtqueue_get_buf(rq->vq, &len);
 970                 if (unlikely(!buf)) {
 971                         pr_debug("%s: rx error: %d buffers missing\n",
 972                                  dev->name, num_buf);
 973                         dev->stats.rx_length_errors++;
 974                         break;
 975                 }
 976                 stats->bytes += len;
 977                 page = virt_to_head_page(buf);
 978                 put_page(page);
 979         }
 980 err_buf:
 981         stats->drops++;
 982         dev_kfree_skb(head_skb);
 983 xdp_xmit:
 984         return NULL;
 985 }
 986
 987 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 988                         void *buf, unsigned int len, void **ctx,
 989                         unsigned int *xdp_xmit,
 990                         struct virtnet_rq_stats *stats)
 991 {
 992         struct net_device *dev = vi->dev;
 993         struct sk_buff *skb;
 994         struct virtio_net_hdr_mrg_rxbuf *hdr;
 995
 996         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 997                 pr_debug("%s: short packet %i\n", dev->name, len);
 998                 dev->stats.rx_length_errors++;
 999                 if (vi->mergeable_rx_bufs) {
1000                         put_page(virt_to_head_page(buf));
1001                 } else if (vi->big_packets) {
1002                         give_pages(rq, buf);
1003                 } else {
1004                         put_page(virt_to_head_page(buf));
1005                 }
1006                 return;
1007         }
1008
1009         if (vi->mergeable_rx_bufs)
1010                 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1011                                         stats);
1012         else if (vi->big_packets)
1013                 skb = receive_big(dev, vi, rq, buf, len, stats);
1014         else
1015                 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1016
1017         if (unlikely(!skb))
1018                 return;
1019
1020         hdr = skb_vnet_hdr(skb);
1021
1022         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1023                 skb->ip_summed = CHECKSUM_UNNECESSARY;
1024
1025         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1026                                   virtio_is_little_endian(vi->vdev))) {
1027                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1028                                      dev->name, hdr->hdr.gso_type,
1029                                      hdr->hdr.gso_size);
1030                 goto frame_err;
1031         }
1032
1033         skb->protocol = eth_type_trans(skb, dev);
1034         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1035                  ntohs(skb->protocol), skb->len, skb->pkt_type);
1036
1037         napi_gro_receive(&rq->napi, skb);
1038         return;
1039
1040 frame_err:
1041         dev->stats.rx_frame_errors++;
1042         dev_kfree_skb(skb);
1043 }
1044
1045 /* Unlike mergeable buffers, all buffers are allocated to the
1046  * same size, except for the headroom. For this reason we do
1047  * not need to use  mergeable_len_to_ctx here - it is enough
1048  * to store the headroom as the context ignoring the truesize.
1049  */
1050 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1051                              gfp_t gfp)
1052 {
1053         struct page_frag *alloc_frag = &rq->alloc_frag;
1054         char *buf;
1055         unsigned int xdp_headroom = virtnet_get_headroom(vi);
1056         void *ctx = (void *)(unsigned long)xdp_headroom;
1057         int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1058         int err;
1059
1060         len = SKB_DATA_ALIGN(len) +
1061               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1062         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1063                 return -ENOMEM;
1064
1065         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1066         get_page(alloc_frag->page);
1067         alloc_frag->offset += len;
1068         sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1069                     vi->hdr_len + GOOD_PACKET_LEN);
1070         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1071         if (err < 0)
1072                 put_page(virt_to_head_page(buf));
1073         return err;
1074 }
1075
1076 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1077                            gfp_t gfp)
1078 {
1079         struct page *first, *list = NULL;
1080         char *p;
1081         int i, err, offset;
1082
1083         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
1084
1085         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
1086         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
1087                 first = get_a_page(rq, gfp);
1088                 if (!first) {
1089                         if (list)
1090                                 give_pages(rq, list);
1091                         return -ENOMEM;
1092                 }
1093                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1094
1095                 /* chain new page in list head to match sg */
1096                 first->private = (unsigned long)list;
1097                 list = first;
1098         }
1099
1100         first = get_a_page(rq, gfp);
1101         if (!first) {
1102                 give_pages(rq, list);
1103                 return -ENOMEM;
1104         }
1105         p = page_address(first);
1106
1107         /* rq->sg[0], rq->sg[1] share the same page */
1108         /* a separated rq->sg[0] for header - required in case !any_header_sg */
1109         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1110
1111         /* rq->sg[1] for data packet, from offset */
1112         offset = sizeof(struct padded_vnet_hdr);
1113         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1114
1115         /* chain first in list head */
1116         first->private = (unsigned long)list;
1117         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
1118                                   first, gfp);
1119         if (err < 0)
1120                 give_pages(rq, first);
1121
1122         return err;
1123 }
1124
1125 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1126                                           struct ewma_pkt_len *avg_pkt_len,
1127                                           unsigned int room)
1128 {
1129         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1130         unsigned int len;
1131
1132         if (room)
1133                 return PAGE_SIZE - room;
1134
1135         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1136                                 rq->min_buf_len, PAGE_SIZE - hdr_len);
1137
1138         return ALIGN(len, L1_CACHE_BYTES);
1139 }
1140
1141 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1142                                  struct receive_queue *rq, gfp_t gfp)
1143 {
1144         struct page_frag *alloc_frag = &rq->alloc_frag;
1145         unsigned int headroom = virtnet_get_headroom(vi);
1146         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1147         unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1148         char *buf;
1149         void *ctx;
1150         int err;
1151         unsigned int len, hole;
1152
1153         /* Extra tailroom is needed to satisfy XDP's assumption. This
1154          * means rx frags coalescing won't work, but consider we've
1155          * disabled GSO for XDP, it won't be a big issue.
1156          */
1157         len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1158         if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1159                 return -ENOMEM;
1160
1161         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1162         buf += headroom; /* advance address leaving hole at front of pkt */
1163         get_page(alloc_frag->page);
1164         alloc_frag->offset += len + room;
1165         hole = alloc_frag->size - alloc_frag->offset;
1166         if (hole < len + room) {
1167                 /* To avoid internal fragmentation, if there is very likely not
1168                  * enough space for another buffer, add the remaining space to
1169                  * the current buffer.
1170                  */
1171                 len += hole;
1172                 alloc_frag->offset += hole;
1173         }
1174
1175         sg_init_one(rq->sg, buf, len);
1176         ctx = mergeable_len_to_ctx(len, headroom);
1177         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1178         if (err < 0)
1179                 put_page(virt_to_head_page(buf));
1180
1181         return err;
1182 }
1183
1184 /*
1185  * Returns false if we couldn't fill entirely (OOM).
1186  *
1187  * Normally run in the receive path, but can also be run from ndo_open
1188  * before we're receiving packets, or from refill_work which is
1189  * careful to disable receiving (using napi_disable).
1190  */
1191 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1192                           gfp_t gfp)
1193 {
1194         int err;
1195         bool oom;
1196
1197         do {
1198                 if (vi->mergeable_rx_bufs)
1199                         err = add_recvbuf_mergeable(vi, rq, gfp);
1200                 else if (vi->big_packets)
1201                         err = add_recvbuf_big(vi, rq, gfp);
1202                 else
1203                         err = add_recvbuf_small(vi, rq, gfp);
1204
1205                 oom = err == -ENOMEM;
1206                 if (err)
1207                         break;
1208         } while (rq->vq->num_free);
1209         if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1210                 u64_stats_update_begin(&rq->stats.syncp);
1211                 rq->stats.kicks++;
1212                 u64_stats_update_end(&rq->stats.syncp);
1213         }
1214
1215         return !oom;
1216 }
1217
1218 static void skb_recv_done(struct virtqueue *rvq)
1219 {
1220         struct virtnet_info *vi = rvq->vdev->priv;
1221         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1222
1223         virtqueue_napi_schedule(&rq->napi, rvq);
1224 }
1225
1226 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1227 {
1228         napi_enable(napi);
1229
1230         /* If all buffers were filled by other side before we napi_enabled, we
1231          * won't get another interrupt, so process any outstanding packets now.
1232          * Call local_bh_enable after to trigger softIRQ processing.
1233          */
1234         local_bh_disable();
1235         virtqueue_napi_schedule(napi, vq);
1236         local_bh_enable();
1237 }
1238
1239 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1240                                    struct virtqueue *vq,
1241                                    struct napi_struct *napi)
1242 {
1243         if (!napi->weight)
1244                 return;
1245
1246         /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1247          * enable the feature if this is likely affine with the transmit path.
1248          */
1249         if (!vi->affinity_hint_set) {
1250                 napi->weight = 0;
1251                 return;
1252         }
1253
1254         return virtnet_napi_enable(vq, napi);
1255 }
1256
1257 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1258 {
1259         if (napi->weight)
1260                 napi_disable(napi);
1261 }
1262
1263 static void refill_work(struct work_struct *work)
1264 {
1265         struct virtnet_info *vi =
1266                 container_of(work, struct virtnet_info, refill.work);
1267         bool still_empty;
1268         int i;
1269
1270         for (i = 0; i < vi->curr_queue_pairs; i++) {
1271                 struct receive_queue *rq = &vi->rq[i];
1272
1273                 napi_disable(&rq->napi);
1274                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1275                 virtnet_napi_enable(rq->vq, &rq->napi);
1276
1277                 /* In theory, this can happen: if we don't get any buffers in
1278                  * we will *never* try to fill again.
1279                  */
1280                 if (still_empty)
1281                         schedule_delayed_work(&vi->refill, HZ/2);
1282         }
1283 }
1284
1285 static int virtnet_receive(struct receive_queue *rq, int budget,
1286                            unsigned int *xdp_xmit)
1287 {
1288         struct virtnet_info *vi = rq->vq->vdev->priv;
1289         struct virtnet_rq_stats stats = {};
1290         unsigned int len;
1291         void *buf;
1292         int i;
1293
1294         if (!vi->big_packets || vi->mergeable_rx_bufs) {
1295                 void *ctx;
1296
1297                 while (stats.packets < budget &&
1298                        (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1299                         receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1300                         stats.packets++;
1301                 }
1302         } else {
1303                 while (stats.packets < budget &&
1304                        (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1305                         receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1306                         stats.packets++;
1307                 }
1308         }
1309
1310         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
1311                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1312                         schedule_delayed_work(&vi->refill, 0);
1313         }
1314
1315         u64_stats_update_begin(&rq->stats.syncp);
1316         for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1317                 size_t offset = virtnet_rq_stats_desc[i].offset;
1318                 u64 *item;
1319
1320                 item = (u64 *)((u8 *)&rq->stats + offset);
1321                 *item += *(u64 *)((u8 *)&stats + offset);
1322         }
1323         u64_stats_update_end(&rq->stats.syncp);
1324
1325         return stats.packets;
1326 }
1327
1328 static void free_old_xmit_skbs(struct send_queue *sq)
1329 {
1330         struct sk_buff *skb;
1331         unsigned int len;
1332         unsigned int packets = 0;
1333         unsigned int bytes = 0;
1334
1335         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1336                 pr_debug("Sent skb %p\n", skb);
1337
1338                 bytes += skb->len;
1339                 packets++;
1340
1341                 dev_consume_skb_any(skb);
1342         }
1343
1344         /* Avoid overhead when no packets have been processed
1345          * happens when called speculatively from start_xmit.
1346          */
1347         if (!packets)
1348                 return;
1349
1350         u64_stats_update_begin(&sq->stats.syncp);
1351         sq->stats.bytes += bytes;
1352         sq->stats.packets += packets;
1353         u64_stats_update_end(&sq->stats.syncp);
1354 }
1355
1356 static void virtnet_poll_cleantx(struct receive_queue *rq)
1357 {
1358         struct virtnet_info *vi = rq->vq->vdev->priv;
1359         unsigned int index = vq2rxq(rq->vq);
1360         struct send_queue *sq = &vi->sq[index];
1361         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1362
1363         if (!sq->napi.weight)
1364                 return;
1365
1366         if (__netif_tx_trylock(txq)) {
1367                 free_old_xmit_skbs(sq);
1368                 __netif_tx_unlock(txq);
1369         }
1370
1371         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1372                 netif_tx_wake_queue(txq);
1373 }
1374
1375 static int virtnet_poll(struct napi_struct *napi, int budget)
1376 {
1377         struct receive_queue *rq =
1378                 container_of(napi, struct receive_queue, napi);
1379         struct virtnet_info *vi = rq->vq->vdev->priv;
1380         struct send_queue *sq;
1381         unsigned int received;
1382         unsigned int xdp_xmit = 0;
1383
1384         virtnet_poll_cleantx(rq);
1385
1386         received = virtnet_receive(rq, budget, &xdp_xmit);
1387
1388         /* Out of packets? */
1389         if (received < budget)
1390                 virtqueue_napi_complete(napi, rq->vq, received);
1391
1392         if (xdp_xmit & VIRTIO_XDP_REDIR)
1393                 xdp_do_flush_map();
1394
1395         if (xdp_xmit & VIRTIO_XDP_TX) {
1396                 sq = virtnet_xdp_sq(vi);
1397                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1398                         u64_stats_update_begin(&sq->stats.syncp);
1399                         sq->stats.kicks++;
1400                         u64_stats_update_end(&sq->stats.syncp);
1401                 }
1402         }
1403
1404         return received;
1405 }
1406
1407 static int virtnet_open(struct net_device *dev)
1408 {
1409         struct virtnet_info *vi = netdev_priv(dev);
1410         int i, err;
1411
1412         for (i = 0; i < vi->max_queue_pairs; i++) {
1413                 if (i < vi->curr_queue_pairs)
1414                         /* Make sure we have some buffers: if oom use wq. */
1415                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1416                                 schedule_delayed_work(&vi->refill, 0);
1417
1418                 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i);
1419                 if (err < 0)
1420                         return err;
1421
1422                 err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1423                                                  MEM_TYPE_PAGE_SHARED, NULL);
1424                 if (err < 0) {
1425                         xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1426                         return err;
1427                 }
1428
1429                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1430                 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1431         }
1432
1433         return 0;
1434 }
1435
1436 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1437 {
1438         struct send_queue *sq = container_of(napi, struct send_queue, napi);
1439         struct virtnet_info *vi = sq->vq->vdev->priv;
1440         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
1441
1442         __netif_tx_lock(txq, raw_smp_processor_id());
1443         free_old_xmit_skbs(sq);
1444         __netif_tx_unlock(txq);
1445
1446         virtqueue_napi_complete(napi, sq->vq, 0);
1447
1448         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1449                 netif_tx_wake_queue(txq);
1450
1451         return 0;
1452 }
1453
1454 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1455 {
1456         struct virtio_net_hdr_mrg_rxbuf *hdr;
1457         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1458         struct virtnet_info *vi = sq->vq->vdev->priv;
1459         int num_sg;
1460         unsigned hdr_len = vi->hdr_len;
1461         bool can_push;
1462
1463         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1464
1465         can_push = vi->any_header_sg &&
1466                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1467                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1468         /* Even if we can, don't push here yet as this would skew
1469          * csum_start offset below. */
1470         if (can_push)
1471                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1472         else
1473                 hdr = skb_vnet_hdr(skb);
1474
1475         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1476                                     virtio_is_little_endian(vi->vdev), false,
1477                                     0))
1478                 BUG();
1479
1480         if (vi->mergeable_rx_bufs)
1481                 hdr->num_buffers = 0;
1482
1483         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1484         if (can_push) {
1485                 __skb_push(skb, hdr_len);
1486                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1487                 if (unlikely(num_sg < 0))
1488                         return num_sg;
1489                 /* Pull header back to avoid skew in tx bytes calculations. */
1490                 __skb_pull(skb, hdr_len);
1491         } else {
1492                 sg_set_buf(sq->sg, hdr, hdr_len);
1493                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1494                 if (unlikely(num_sg < 0))
1495                         return num_sg;
1496                 num_sg++;
1497         }
1498         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1499 }
1500
1501 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1502 {
1503         struct virtnet_info *vi = netdev_priv(dev);
1504         int qnum = skb_get_queue_mapping(skb);
1505         struct send_queue *sq = &vi->sq[qnum];
1506         int err;
1507         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1508         bool kick = !skb->xmit_more;
1509         bool use_napi = sq->napi.weight;
1510
1511         /* Free up any pending old buffers before queueing new ones. */
1512         free_old_xmit_skbs(sq);
1513
1514         if (use_napi && kick)
1515                 virtqueue_enable_cb_delayed(sq->vq);
1516
1517         /* timestamp packet in software */
1518         skb_tx_timestamp(skb);
1519
1520         /* Try to transmit */
1521         err = xmit_skb(sq, skb);
1522
1523         /* This should not happen! */
1524         if (unlikely(err)) {
1525                 dev->stats.tx_fifo_errors++;
1526                 if (net_ratelimit())
1527                         dev_warn(&dev->dev,
1528                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
1529                 dev->stats.tx_dropped++;
1530                 dev_kfree_skb_any(skb);
1531                 return NETDEV_TX_OK;
1532         }
1533
1534         /* Don't wait up for transmitted skbs to be freed. */
1535         if (!use_napi) {
1536                 skb_orphan(skb);
1537                 nf_reset(skb);
1538         }
1539
1540         /* If running out of space, stop queue to avoid getting packets that we
1541          * are then unable to transmit.
1542          * An alternative would be to force queuing layer to requeue the skb by
1543          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1544          * returned in a normal path of operation: it means that driver is not
1545          * maintaining the TX queue stop/start state properly, and causes
1546          * the stack to do a non-trivial amount of useless work.
1547          * Since most packets only take 1 or 2 ring slots, stopping the queue
1548          * early means 16 slots are typically wasted.
1549          */
1550         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1551                 netif_stop_subqueue(dev, qnum);
1552                 if (!use_napi &&
1553                     unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1554                         /* More just got used, free them then recheck. */
1555                         free_old_xmit_skbs(sq);
1556                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1557                                 netif_start_subqueue(dev, qnum);
1558                                 virtqueue_disable_cb(sq->vq);
1559                         }
1560                 }
1561         }
1562
1563         if (kick || netif_xmit_stopped(txq)) {
1564                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1565                         u64_stats_update_begin(&sq->stats.syncp);
1566                         sq->stats.kicks++;
1567                         u64_stats_update_end(&sq->stats.syncp);
1568                 }
1569         }
1570
1571         return NETDEV_TX_OK;
1572 }
1573
1574 /*
1575  * Send command via the control virtqueue and check status.  Commands
1576  * supported by the hypervisor, as indicated by feature bits, should
1577  * never fail unless improperly formatted.
1578  */
1579 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1580                                  struct scatterlist *out)
1581 {
1582         struct scatterlist *sgs[4], hdr, stat;
1583         unsigned out_num = 0, tmp;
1584
1585         /* Caller should know better */
1586         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1587
1588         vi->ctrl->status = ~0;
1589         vi->ctrl->hdr.class = class;
1590         vi->ctrl->hdr.cmd = cmd;
1591         /* Add header */
1592         sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1593         sgs[out_num++] = &hdr;
1594
1595         if (out)
1596                 sgs[out_num++] = out;
1597
1598         /* Add return status. */
1599         sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1600         sgs[out_num] = &stat;
1601
1602         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1603         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1604
1605         if (unlikely(!virtqueue_kick(vi->cvq)))
1606                 return vi->ctrl->status == VIRTIO_NET_OK;
1607
1608         /* Spin for a response, the kick causes an ioport write, trapping
1609          * into the hypervisor, so the request should be handled immediately.
1610          */
1611         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1612                !virtqueue_is_broken(vi->cvq))
1613                 cpu_relax();
1614
1615         return vi->ctrl->status == VIRTIO_NET_OK;
1616 }
1617
1618 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1619 {
1620         struct virtnet_info *vi = netdev_priv(dev);
1621         struct virtio_device *vdev = vi->vdev;
1622         int ret;
1623         struct sockaddr *addr;
1624         struct scatterlist sg;
1625
1626         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
1627                 return -EOPNOTSUPP;
1628
1629         addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1630         if (!addr)
1631                 return -ENOMEM;
1632
1633         ret = eth_prepare_mac_addr_change(dev, addr);
1634         if (ret)
1635                 goto out;
1636
1637         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1638                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1639                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1640                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1641                         dev_warn(&vdev->dev,
1642                                  "Failed to set mac address by vq command.\n");
1643                         ret = -EINVAL;
1644                         goto out;
1645                 }
1646         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1647                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1648                 unsigned int i;
1649
1650                 /* Naturally, this has an atomicity problem. */
1651                 for (i = 0; i < dev->addr_len; i++)
1652                         virtio_cwrite8(vdev,
1653                                        offsetof(struct virtio_net_config, mac) +
1654                                        i, addr->sa_data[i]);
1655         }
1656
1657         eth_commit_mac_addr_change(dev, p);
1658         ret = 0;
1659
1660 out:
1661         kfree(addr);
1662         return ret;
1663 }
1664
1665 static void virtnet_stats(struct net_device *dev,
1666                           struct rtnl_link_stats64 *tot)
1667 {
1668         struct virtnet_info *vi = netdev_priv(dev);
1669         unsigned int start;
1670         int i;
1671
1672         for (i = 0; i < vi->max_queue_pairs; i++) {
1673                 u64 tpackets, tbytes, rpackets, rbytes, rdrops;
1674                 struct receive_queue *rq = &vi->rq[i];
1675                 struct send_queue *sq = &vi->sq[i];
1676
1677                 do {
1678                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1679                         tpackets = sq->stats.packets;
1680                         tbytes   = sq->stats.bytes;
1681                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1682
1683                 do {
1684                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1685                         rpackets = rq->stats.packets;
1686                         rbytes   = rq->stats.bytes;
1687                         rdrops   = rq->stats.drops;
1688                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1689
1690                 tot->rx_packets += rpackets;
1691                 tot->tx_packets += tpackets;
1692                 tot->rx_bytes   += rbytes;
1693                 tot->tx_bytes   += tbytes;
1694                 tot->rx_dropped += rdrops;
1695         }
1696
1697         tot->tx_dropped = dev->stats.tx_dropped;
1698         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1699         tot->rx_length_errors = dev->stats.rx_length_errors;
1700         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1701 }
1702
1703 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1704 {
1705         rtnl_lock();
1706         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1707                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1708                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1709         rtnl_unlock();
1710 }
1711
1712 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1713 {
1714         struct scatterlist sg;
1715         struct net_device *dev = vi->dev;
1716
1717         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1718                 return 0;
1719
1720         vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1721         sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
1722
1723         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1724                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1725                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1726                          queue_pairs);
1727                 return -EINVAL;
1728         } else {
1729                 vi->curr_queue_pairs = queue_pairs;
1730                 /* virtnet_open() will refill when device is going to up. */
1731                 if (dev->flags & IFF_UP)
1732                         schedule_delayed_work(&vi->refill, 0);
1733         }
1734
1735         return 0;
1736 }
1737
1738 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1739 {
1740         int err;
1741
1742         rtnl_lock();
1743         err = _virtnet_set_queues(vi, queue_pairs);
1744         rtnl_unlock();
1745         return err;
1746 }
1747
1748 static int virtnet_close(struct net_device *dev)
1749 {
1750         struct virtnet_info *vi = netdev_priv(dev);
1751         int i;
1752
1753         /* Make sure refill_work doesn't re-enable napi! */
1754         cancel_delayed_work_sync(&vi->refill);
1755
1756         for (i = 0; i < vi->max_queue_pairs; i++) {
1757                 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1758                 napi_disable(&vi->rq[i].napi);
1759                 virtnet_napi_tx_disable(&vi->sq[i].napi);
1760         }
1761
1762         return 0;
1763 }
1764
1765 static void virtnet_set_rx_mode(struct net_device *dev)
1766 {
1767         struct virtnet_info *vi = netdev_priv(dev);
1768         struct scatterlist sg[2];
1769         struct virtio_net_ctrl_mac *mac_data;
1770         struct netdev_hw_addr *ha;
1771         int uc_count;
1772         int mc_count;
1773         void *buf;
1774         int i;
1775
1776         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1777         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1778                 return;
1779
1780         vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
1781         vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1782
1783         sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
1784
1785         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1786                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1787                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1788                          vi->ctrl->promisc ? "en" : "dis");
1789
1790         sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
1791
1792         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1793                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1794                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1795                          vi->ctrl->allmulti ? "en" : "dis");
1796
1797         uc_count = netdev_uc_count(dev);
1798         mc_count = netdev_mc_count(dev);
1799         /* MAC filter - use one buffer for both lists */
1800         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1801                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1802         mac_data = buf;
1803         if (!buf)
1804                 return;
1805
1806         sg_init_table(sg, 2);
1807
1808         /* Store the unicast list and count in the front of the buffer */
1809         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1810         i = 0;
1811         netdev_for_each_uc_addr(ha, dev)
1812                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1813
1814         sg_set_buf(&sg[0], mac_data,
1815                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1816
1817         /* multicast list and count fill the end */
1818         mac_data = (void *)&mac_data->macs[uc_count][0];
1819
1820         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1821         i = 0;
1822         netdev_for_each_mc_addr(ha, dev)
1823                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1824
1825         sg_set_buf(&sg[1], mac_data,
1826                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1827
1828         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1829                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1830                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1831
1832         kfree(buf);
1833 }
1834
1835 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1836                                    __be16 proto, u16 vid)
1837 {
1838         struct virtnet_info *vi = netdev_priv(dev);
1839         struct scatterlist sg;
1840
1841         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1842         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1843
1844         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1845                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1846                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1847         return 0;
1848 }
1849
1850 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1851                                     __be16 proto, u16 vid)
1852 {
1853         struct virtnet_info *vi = netdev_priv(dev);
1854         struct scatterlist sg;
1855
1856         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1857         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1858
1859         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1860                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1861                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1862         return 0;
1863 }
1864
1865 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1866 {
1867         int i;
1868
1869         if (vi->affinity_hint_set) {
1870                 for (i = 0; i < vi->max_queue_pairs; i++) {
1871                         virtqueue_set_affinity(vi->rq[i].vq, NULL);
1872                         virtqueue_set_affinity(vi->sq[i].vq, NULL);
1873                 }
1874
1875                 vi->affinity_hint_set = false;
1876         }
1877 }
1878
1879 static void virtnet_set_affinity(struct virtnet_info *vi)
1880 {
1881         cpumask_var_t mask;
1882         int stragglers;
1883         int group_size;
1884         int i, j, cpu;
1885         int num_cpu;
1886         int stride;
1887
1888         if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
1889                 virtnet_clean_affinity(vi, -1);
1890                 return;
1891         }
1892
1893         num_cpu = num_online_cpus();
1894         stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
1895         stragglers = num_cpu >= vi->curr_queue_pairs ?
1896                         num_cpu % vi->curr_queue_pairs :
1897                         0;
1898         cpu = cpumask_next(-1, cpu_online_mask);
1899
1900         for (i = 0; i < vi->curr_queue_pairs; i++) {
1901                 group_size = stride + (i < stragglers ? 1 : 0);
1902
1903                 for (j = 0; j < group_size; j++) {
1904                         cpumask_set_cpu(cpu, mask);
1905                         cpu = cpumask_next_wrap(cpu, cpu_online_mask,
1906                                                 nr_cpu_ids, false);
1907                 }
1908                 virtqueue_set_affinity(vi->rq[i].vq, mask);
1909                 virtqueue_set_affinity(vi->sq[i].vq, mask);
1910                 __netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, false);
1911                 cpumask_clear(mask);
1912         }
1913
1914         vi->affinity_hint_set = true;
1915         free_cpumask_var(mask);
1916 }
1917
1918 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1919 {
1920         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1921                                                    node);
1922         virtnet_set_affinity(vi);
1923         return 0;
1924 }
1925
1926 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1927 {
1928         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1929                                                    node_dead);
1930         virtnet_set_affinity(vi);
1931         return 0;
1932 }
1933
1934 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1935 {
1936         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1937                                                    node);
1938
1939         virtnet_clean_affinity(vi, cpu);
1940         return 0;
1941 }
1942
1943 static enum cpuhp_state virtionet_online;
1944
1945 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1946 {
1947         int ret;
1948
1949         ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
1950         if (ret)
1951                 return ret;
1952         ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1953                                                &vi->node_dead);
1954         if (!ret)
1955                 return ret;
1956         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1957         return ret;
1958 }
1959
1960 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
1961 {
1962         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1963         cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1964                                             &vi->node_dead);
1965 }
1966
1967 static void virtnet_get_ringparam(struct net_device *dev,
1968                                 struct ethtool_ringparam *ring)
1969 {
1970         struct virtnet_info *vi = netdev_priv(dev);
1971
1972         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1973         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1974         ring->rx_pending = ring->rx_max_pending;
1975         ring->tx_pending = ring->tx_max_pending;
1976 }
1977
1978
1979 static void virtnet_get_drvinfo(struct net_device *dev,
1980                                 struct ethtool_drvinfo *info)
1981 {
1982         struct virtnet_info *vi = netdev_priv(dev);
1983         struct virtio_device *vdev = vi->vdev;
1984
1985         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1986         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1987         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1988
1989 }
1990
1991 /* TODO: Eliminate OOO packets during switching */
1992 static int virtnet_set_channels(struct net_device *dev,
1993                                 struct ethtool_channels *channels)
1994 {
1995         struct virtnet_info *vi = netdev_priv(dev);
1996         u16 queue_pairs = channels->combined_count;
1997         int err;
1998
1999         /* We don't support separate rx/tx channels.
2000          * We don't allow setting 'other' channels.
2001          */
2002         if (channels->rx_count || channels->tx_count || channels->other_count)
2003                 return -EINVAL;
2004
2005         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2006                 return -EINVAL;
2007
2008         /* For now we don't support modifying channels while XDP is loaded
2009          * also when XDP is loaded all RX queues have XDP programs so we only
2010          * need to check a single RX queue.
2011          */
2012         if (vi->rq[0].xdp_prog)
2013                 return -EINVAL;
2014
2015         get_online_cpus();
2016         err = _virtnet_set_queues(vi, queue_pairs);
2017         if (!err) {
2018                 netif_set_real_num_tx_queues(dev, queue_pairs);
2019                 netif_set_real_num_rx_queues(dev, queue_pairs);
2020
2021                 virtnet_set_affinity(vi);
2022         }
2023         put_online_cpus();
2024
2025         return err;
2026 }
2027
2028 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2029 {
2030         struct virtnet_info *vi = netdev_priv(dev);
2031         char *p = (char *)data;
2032         unsigned int i, j;
2033
2034         switch (stringset) {
2035         case ETH_SS_STATS:
2036                 for (i = 0; i < vi->curr_queue_pairs; i++) {
2037                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2038                                 snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
2039                                          i, virtnet_rq_stats_desc[j].desc);
2040                                 p += ETH_GSTRING_LEN;
2041                         }
2042                 }
2043
2044                 for (i = 0; i < vi->curr_queue_pairs; i++) {
2045                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2046                                 snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
2047                                          i, virtnet_sq_stats_desc[j].desc);
2048                                 p += ETH_GSTRING_LEN;
2049                         }
2050                 }
2051                 break;
2052         }
2053 }
2054
2055 static int virtnet_get_sset_count(struct net_device *dev, int sset)
2056 {
2057         struct virtnet_info *vi = netdev_priv(dev);
2058
2059         switch (sset) {
2060         case ETH_SS_STATS:
2061                 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2062                                                VIRTNET_SQ_STATS_LEN);
2063         default:
2064                 return -EOPNOTSUPP;
2065         }
2066 }
2067
2068 static void virtnet_get_ethtool_stats(struct net_device *dev,
2069                                       struct ethtool_stats *stats, u64 *data)
2070 {
2071         struct virtnet_info *vi = netdev_priv(dev);
2072         unsigned int idx = 0, start, i, j;
2073         const u8 *stats_base;
2074         size_t offset;
2075
2076         for (i = 0; i < vi->curr_queue_pairs; i++) {
2077                 struct receive_queue *rq = &vi->rq[i];
2078
2079                 stats_base = (u8 *)&rq->stats;
2080                 do {
2081                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
2082                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2083                                 offset = virtnet_rq_stats_desc[j].offset;
2084                                 data[idx + j] = *(u64 *)(stats_base + offset);
2085                         }
2086                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
2087                 idx += VIRTNET_RQ_STATS_LEN;
2088         }
2089
2090         for (i = 0; i < vi->curr_queue_pairs; i++) {
2091                 struct send_queue *sq = &vi->sq[i];
2092
2093                 stats_base = (u8 *)&sq->stats;
2094                 do {
2095                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
2096                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2097                                 offset = virtnet_sq_stats_desc[j].offset;
2098                                 data[idx + j] = *(u64 *)(stats_base + offset);
2099                         }
2100                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
2101                 idx += VIRTNET_SQ_STATS_LEN;
2102         }
2103 }
2104
2105 static void virtnet_get_channels(struct net_device *dev,
2106                                  struct ethtool_channels *channels)
2107 {
2108         struct virtnet_info *vi = netdev_priv(dev);
2109
2110         channels->combined_count = vi->curr_queue_pairs;
2111         channels->max_combined = vi->max_queue_pairs;
2112         channels->max_other = 0;
2113         channels->rx_count = 0;
2114         channels->tx_count = 0;
2115         channels->other_count = 0;
2116 }
2117
2118 /* Check if the user is trying to change anything besides speed/duplex */
2119 static bool
2120 virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
2121 {
2122         struct ethtool_link_ksettings diff1 = *cmd;
2123         struct ethtool_link_ksettings diff2 = {};
2124
2125         /* cmd is always set so we need to clear it, validate the port type
2126          * and also without autonegotiation we can ignore advertising
2127          */
2128         diff1.base.speed = 0;
2129         diff2.base.port = PORT_OTHER;
2130         ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
2131         diff1.base.duplex = 0;
2132         diff1.base.cmd = 0;
2133         diff1.base.link_mode_masks_nwords = 0;
2134
2135         return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
2136                 bitmap_empty(diff1.link_modes.supported,
2137                              __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2138                 bitmap_empty(diff1.link_modes.advertising,
2139                              __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2140                 bitmap_empty(diff1.link_modes.lp_advertising,
2141                              __ETHTOOL_LINK_MODE_MASK_NBITS);
2142 }
2143
2144 static int virtnet_set_link_ksettings(struct net_device *dev,
2145                                       const struct ethtool_link_ksettings *cmd)
2146 {
2147         struct virtnet_info *vi = netdev_priv(dev);
2148         u32 speed;
2149
2150         speed = cmd->base.speed;
2151         /* don't allow custom speed and duplex */
2152         if (!ethtool_validate_speed(speed) ||
2153             !ethtool_validate_duplex(cmd->base.duplex) ||
2154             !virtnet_validate_ethtool_cmd(cmd))
2155                 return -EINVAL;
2156         vi->speed = speed;
2157         vi->duplex = cmd->base.duplex;
2158
2159         return 0;
2160 }
2161
2162 static int virtnet_get_link_ksettings(struct net_device *dev,
2163                                       struct ethtool_link_ksettings *cmd)
2164 {
2165         struct virtnet_info *vi = netdev_priv(dev);
2166
2167         cmd->base.speed = vi->speed;
2168         cmd->base.duplex = vi->duplex;
2169         cmd->base.port = PORT_OTHER;
2170
2171         return 0;
2172 }
2173
2174 static int virtnet_set_coalesce(struct net_device *dev,
2175                                 struct ethtool_coalesce *ec)
2176 {
2177         struct ethtool_coalesce ec_default = {
2178                 .cmd = ETHTOOL_SCOALESCE,
2179                 .rx_max_coalesced_frames = 1,
2180         };
2181         struct virtnet_info *vi = netdev_priv(dev);
2182         int i, napi_weight;
2183
2184         if (ec->tx_max_coalesced_frames > 1)
2185                 return -EINVAL;
2186
2187         ec_default.tx_max_coalesced_frames = ec->tx_max_coalesced_frames;
2188         napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2189
2190         /* disallow changes to fields not explicitly tested above */
2191         if (memcmp(ec, &ec_default, sizeof(ec_default)))
2192                 return -EINVAL;
2193
2194         if (napi_weight ^ vi->sq[0].napi.weight) {
2195                 if (dev->flags & IFF_UP)
2196                         return -EBUSY;
2197                 for (i = 0; i < vi->max_queue_pairs; i++)
2198                         vi->sq[i].napi.weight = napi_weight;
2199         }
2200
2201         return 0;
2202 }
2203
2204 static int virtnet_get_coalesce(struct net_device *dev,
2205                                 struct ethtool_coalesce *ec)
2206 {
2207         struct ethtool_coalesce ec_default = {
2208                 .cmd = ETHTOOL_GCOALESCE,
2209                 .rx_max_coalesced_frames = 1,
2210         };
2211         struct virtnet_info *vi = netdev_priv(dev);
2212
2213         memcpy(ec, &ec_default, sizeof(ec_default));
2214
2215         if (vi->sq[0].napi.weight)
2216                 ec->tx_max_coalesced_frames = 1;
2217
2218         return 0;
2219 }
2220
2221 static void virtnet_init_settings(struct net_device *dev)
2222 {
2223         struct virtnet_info *vi = netdev_priv(dev);
2224
2225         vi->speed = SPEED_UNKNOWN;
2226         vi->duplex = DUPLEX_UNKNOWN;
2227 }
2228
2229 static void virtnet_update_settings(struct virtnet_info *vi)
2230 {
2231         u32 speed;
2232         u8 duplex;
2233
2234         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2235                 return;
2236
2237         speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
2238                                                   speed));
2239         if (ethtool_validate_speed(speed))
2240                 vi->speed = speed;
2241         duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
2242                                                   duplex));
2243         if (ethtool_validate_duplex(duplex))
2244                 vi->duplex = duplex;
2245 }
2246
2247 static const struct ethtool_ops virtnet_ethtool_ops = {
2248         .get_drvinfo = virtnet_get_drvinfo,
2249         .get_link = ethtool_op_get_link,
2250         .get_ringparam = virtnet_get_ringparam,
2251         .get_strings = virtnet_get_strings,
2252         .get_sset_count = virtnet_get_sset_count,
2253         .get_ethtool_stats = virtnet_get_ethtool_stats,
2254         .set_channels = virtnet_set_channels,
2255         .get_channels = virtnet_get_channels,
2256         .get_ts_info = ethtool_op_get_ts_info,
2257         .get_link_ksettings = virtnet_get_link_ksettings,
2258         .set_link_ksettings = virtnet_set_link_ksettings,
2259         .set_coalesce = virtnet_set_coalesce,
2260         .get_coalesce = virtnet_get_coalesce,
2261 };
2262
2263 static void virtnet_freeze_down(struct virtio_device *vdev)
2264 {
2265         struct virtnet_info *vi = vdev->priv;
2266         int i;
2267
2268         /* Make sure no work handler is accessing the device */
2269         flush_work(&vi->config_work);
2270
2271         netif_tx_lock_bh(vi->dev);
2272         netif_device_detach(vi->dev);
2273         netif_tx_unlock_bh(vi->dev);
2274         cancel_delayed_work_sync(&vi->refill);
2275
2276         if (netif_running(vi->dev)) {
2277                 for (i = 0; i < vi->max_queue_pairs; i++) {
2278                         napi_disable(&vi->rq[i].napi);
2279                         virtnet_napi_tx_disable(&vi->sq[i].napi);
2280                 }
2281         }
2282 }
2283
2284 static int init_vqs(struct virtnet_info *vi);
2285
2286 static int virtnet_restore_up(struct virtio_device *vdev)
2287 {
2288         struct virtnet_info *vi = vdev->priv;
2289         int err, i;
2290
2291         err = init_vqs(vi);
2292         if (err)
2293                 return err;
2294
2295         virtio_device_ready(vdev);
2296
2297         if (netif_running(vi->dev)) {
2298                 for (i = 0; i < vi->curr_queue_pairs; i++)
2299                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2300                                 schedule_delayed_work(&vi->refill, 0);
2301
2302                 for (i = 0; i < vi->max_queue_pairs; i++) {
2303                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2304                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2305                                                &vi->sq[i].napi);
2306                 }
2307         }
2308
2309         netif_tx_lock_bh(vi->dev);
2310         netif_device_attach(vi->dev);
2311         netif_tx_unlock_bh(vi->dev);
2312         return err;
2313 }
2314
2315 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2316 {
2317         struct scatterlist sg;
2318         vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
2319
2320         sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
2321
2322         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2323                                   VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2324                 dev_warn(&vi->dev->dev, "Fail to set guest offload. \n");
2325                 return -EINVAL;
2326         }
2327
2328         return 0;
2329 }
2330
2331 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2332 {
2333         u64 offloads = 0;
2334
2335         if (!vi->guest_offloads)
2336                 return 0;
2337
2338         return virtnet_set_guest_offloads(vi, offloads);
2339 }
2340
2341 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2342 {
2343         u64 offloads = vi->guest_offloads;
2344
2345         if (!vi->guest_offloads)
2346                 return 0;
2347
2348         return virtnet_set_guest_offloads(vi, offloads);
2349 }
2350
2351 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2352                            struct netlink_ext_ack *extack)
2353 {
2354         unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2355         struct virtnet_info *vi = netdev_priv(dev);
2356         struct bpf_prog *old_prog;
2357         u16 xdp_qp = 0, curr_qp;
2358         int i, err;
2359
2360         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2361             && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2362                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2363                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2364                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
2365                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
2366                 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO/CSUM, disable LRO/CSUM first");
2367                 return -EOPNOTSUPP;
2368         }
2369
2370         if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2371                 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2372                 return -EINVAL;
2373         }
2374
2375         if (dev->mtu > max_sz) {
2376                 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2377                 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2378                 return -EINVAL;
2379         }
2380
2381         curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2382         if (prog)
2383                 xdp_qp = nr_cpu_ids;
2384
2385         /* XDP requires extra queues for XDP_TX */
2386         if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2387                 NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
2388                 netdev_warn(dev, "request %i queues but max is %i\n",
2389                             curr_qp + xdp_qp, vi->max_queue_pairs);
2390                 return -ENOMEM;
2391         }
2392
2393         if (prog) {
2394                 prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
2395                 if (IS_ERR(prog))
2396                         return PTR_ERR(prog);
2397         }
2398
2399         /* Make sure NAPI is not using any XDP TX queues for RX. */
2400         if (netif_running(dev))
2401                 for (i = 0; i < vi->max_queue_pairs; i++)
2402                         napi_disable(&vi->rq[i].napi);
2403
2404         netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2405         err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2406         if (err)
2407                 goto err;
2408         vi->xdp_queue_pairs = xdp_qp;
2409
2410         for (i = 0; i < vi->max_queue_pairs; i++) {
2411                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2412                 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2413                 if (i == 0) {
2414                         if (!old_prog)
2415                                 virtnet_clear_guest_offloads(vi);
2416                         if (!prog)
2417                                 virtnet_restore_guest_offloads(vi);
2418                 }
2419                 if (old_prog)
2420                         bpf_prog_put(old_prog);
2421                 if (netif_running(dev))
2422                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2423         }
2424
2425         return 0;
2426
2427 err:
2428         for (i = 0; i < vi->max_queue_pairs; i++)
2429                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2430         if (prog)
2431                 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2432         return err;
2433 }
2434
2435 static u32 virtnet_xdp_query(struct net_device *dev)
2436 {
2437         struct virtnet_info *vi = netdev_priv(dev);
2438         const struct bpf_prog *xdp_prog;
2439         int i;
2440
2441         for (i = 0; i < vi->max_queue_pairs; i++) {
2442                 xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2443                 if (xdp_prog)
2444                         return xdp_prog->aux->id;
2445         }
2446         return 0;
2447 }
2448
2449 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2450 {
2451         switch (xdp->command) {
2452         case XDP_SETUP_PROG:
2453                 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2454         case XDP_QUERY_PROG:
2455                 xdp->prog_id = virtnet_xdp_query(dev);
2456                 return 0;
2457         default:
2458                 return -EINVAL;
2459         }
2460 }
2461
2462 static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
2463                                       size_t len)
2464 {
2465         struct virtnet_info *vi = netdev_priv(dev);
2466         int ret;
2467
2468         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2469                 return -EOPNOTSUPP;
2470
2471         ret = snprintf(buf, len, "sby");
2472         if (ret >= len)
2473                 return -EOPNOTSUPP;
2474
2475         return 0;
2476 }
2477
2478 static const struct net_device_ops virtnet_netdev = {
2479         .ndo_open            = virtnet_open,
2480         .ndo_stop            = virtnet_close,
2481         .ndo_start_xmit      = start_xmit,
2482         .ndo_validate_addr   = eth_validate_addr,
2483         .ndo_set_mac_address = virtnet_set_mac_address,
2484         .ndo_set_rx_mode     = virtnet_set_rx_mode,
2485         .ndo_get_stats64     = virtnet_stats,
2486         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2487         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2488         .ndo_bpf                = virtnet_xdp,
2489         .ndo_xdp_xmit           = virtnet_xdp_xmit,
2490         .ndo_features_check     = passthru_features_check,
2491         .ndo_get_phys_port_name = virtnet_get_phys_port_name,
2492 };
2493
2494 static void virtnet_config_changed_work(struct work_struct *work)
2495 {
2496         struct virtnet_info *vi =
2497                 container_of(work, struct virtnet_info, config_work);
2498         u16 v;
2499
2500         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2501                                  struct virtio_net_config, status, &v) < 0)
2502                 return;
2503
2504         if (v & VIRTIO_NET_S_ANNOUNCE) {
2505                 netdev_notify_peers(vi->dev);
2506                 virtnet_ack_link_announce(vi);
2507         }
2508
2509         /* Ignore unknown (future) status bits */
2510         v &= VIRTIO_NET_S_LINK_UP;
2511
2512         if (vi->status == v)
2513                 return;
2514
2515         vi->status = v;
2516
2517         if (vi->status & VIRTIO_NET_S_LINK_UP) {
2518                 virtnet_update_settings(vi);
2519                 netif_carrier_on(vi->dev);
2520                 netif_tx_wake_all_queues(vi->dev);
2521         } else {
2522                 netif_carrier_off(vi->dev);
2523                 netif_tx_stop_all_queues(vi->dev);
2524         }
2525 }
2526
2527 static void virtnet_config_changed(struct virtio_device *vdev)
2528 {
2529         struct virtnet_info *vi = vdev->priv;
2530
2531         schedule_work(&vi->config_work);
2532 }
2533
2534 static void virtnet_free_queues(struct virtnet_info *vi)
2535 {
2536         int i;
2537
2538         for (i = 0; i < vi->max_queue_pairs; i++) {
2539                 napi_hash_del(&vi->rq[i].napi);
2540                 netif_napi_del(&vi->rq[i].napi);
2541                 netif_napi_del(&vi->sq[i].napi);
2542         }
2543
2544         /* We called napi_hash_del() before netif_napi_del(),
2545          * we need to respect an RCU grace period before freeing vi->rq
2546          */
2547         synchronize_net();
2548
2549         kfree(vi->rq);
2550         kfree(vi->sq);
2551         kfree(vi->ctrl);
2552 }
2553
2554 static void _free_receive_bufs(struct virtnet_info *vi)
2555 {
2556         struct bpf_prog *old_prog;
2557         int i;
2558
2559         for (i = 0; i < vi->max_queue_pairs; i++) {
2560                 while (vi->rq[i].pages)
2561                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2562
2563                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2564                 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2565                 if (old_prog)
2566                         bpf_prog_put(old_prog);
2567         }
2568 }
2569
2570 static void free_receive_bufs(struct virtnet_info *vi)
2571 {
2572         rtnl_lock();
2573         _free_receive_bufs(vi);
2574         rtnl_unlock();
2575 }
2576
2577 static void free_receive_page_frags(struct virtnet_info *vi)
2578 {
2579         int i;
2580         for (i = 0; i < vi->max_queue_pairs; i++)
2581                 if (vi->rq[i].alloc_frag.page)
2582                         put_page(vi->rq[i].alloc_frag.page);
2583 }
2584
2585 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
2586 {
2587         if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
2588                 return false;
2589         else if (q < vi->curr_queue_pairs)
2590                 return true;
2591         else
2592                 return false;
2593 }
2594
2595 static void free_unused_bufs(struct virtnet_info *vi)
2596 {
2597         void *buf;
2598         int i;
2599
2600         for (i = 0; i < vi->max_queue_pairs; i++) {
2601                 struct virtqueue *vq = vi->sq[i].vq;
2602                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2603                         if (!is_xdp_raw_buffer_queue(vi, i))
2604                                 dev_kfree_skb(buf);
2605                         else
2606                                 put_page(virt_to_head_page(buf));
2607                 }
2608         }
2609
2610         for (i = 0; i < vi->max_queue_pairs; i++) {
2611                 struct virtqueue *vq = vi->rq[i].vq;
2612
2613                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2614                         if (vi->mergeable_rx_bufs) {
2615                                 put_page(virt_to_head_page(buf));
2616                         } else if (vi->big_packets) {
2617                                 give_pages(&vi->rq[i], buf);
2618                         } else {
2619                                 put_page(virt_to_head_page(buf));
2620                         }
2621                 }
2622         }
2623 }
2624
2625 static void virtnet_del_vqs(struct virtnet_info *vi)
2626 {
2627         struct virtio_device *vdev = vi->vdev;
2628
2629         virtnet_clean_affinity(vi, -1);
2630
2631         vdev->config->del_vqs(vdev);
2632
2633         virtnet_free_queues(vi);
2634 }
2635
2636 /* How large should a single buffer be so a queue full of these can fit at
2637  * least one full packet?
2638  * Logic below assumes the mergeable buffer header is used.
2639  */
2640 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2641 {
2642         const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2643         unsigned int rq_size = virtqueue_get_vring_size(vq);
2644         unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2645         unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2646         unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2647
2648         return max(max(min_buf_len, hdr_len) - hdr_len,
2649                    (unsigned int)GOOD_PACKET_LEN);
2650 }
2651
2652 static int virtnet_find_vqs(struct virtnet_info *vi)
2653 {
2654         vq_callback_t **callbacks;
2655         struct virtqueue **vqs;
2656         int ret = -ENOMEM;
2657         int i, total_vqs;
2658         const char **names;
2659         bool *ctx;
2660
2661         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2662          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2663          * possible control vq.
2664          */
2665         total_vqs = vi->max_queue_pairs * 2 +
2666                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2667
2668         /* Allocate space for find_vqs parameters */
2669         vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
2670         if (!vqs)
2671                 goto err_vq;
2672         callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
2673         if (!callbacks)
2674                 goto err_callback;
2675         names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
2676         if (!names)
2677                 goto err_names;
2678         if (!vi->big_packets || vi->mergeable_rx_bufs) {
2679                 ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
2680                 if (!ctx)
2681                         goto err_ctx;
2682         } else {
2683                 ctx = NULL;
2684         }
2685
2686         /* Parameters for control virtqueue, if any */
2687         if (vi->has_cvq) {
2688                 callbacks[total_vqs - 1] = NULL;
2689                 names[total_vqs - 1] = "control";
2690         }
2691
2692         /* Allocate/initialize parameters for send/receive virtqueues */
2693         for (i = 0; i < vi->max_queue_pairs; i++) {
2694                 callbacks[rxq2vq(i)] = skb_recv_done;
2695                 callbacks[txq2vq(i)] = skb_xmit_done;
2696                 sprintf(vi->rq[i].name, "input.%d", i);
2697                 sprintf(vi->sq[i].name, "output.%d", i);
2698                 names[rxq2vq(i)] = vi->rq[i].name;
2699                 names[txq2vq(i)] = vi->sq[i].name;
2700                 if (ctx)
2701                         ctx[rxq2vq(i)] = true;
2702         }
2703
2704         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2705                                          names, ctx, NULL);
2706         if (ret)
2707                 goto err_find;
2708
2709         if (vi->has_cvq) {
2710                 vi->cvq = vqs[total_vqs - 1];
2711                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2712                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2713         }
2714
2715         for (i = 0; i < vi->max_queue_pairs; i++) {
2716                 vi->rq[i].vq = vqs[rxq2vq(i)];
2717                 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2718                 vi->sq[i].vq = vqs[txq2vq(i)];
2719         }
2720
2721         /* run here: ret == 0. */
2722
2723
2724 err_find:
2725         kfree(ctx);
2726 err_ctx:
2727         kfree(names);
2728 err_names:
2729         kfree(callbacks);
2730 err_callback:
2731         kfree(vqs);
2732 err_vq:
2733         return ret;
2734 }
2735
2736 static int virtnet_alloc_queues(struct virtnet_info *vi)
2737 {
2738         int i;
2739
2740         vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
2741         if (!vi->ctrl)
2742                 goto err_ctrl;
2743         vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
2744         if (!vi->sq)
2745                 goto err_sq;
2746         vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
2747         if (!vi->rq)
2748                 goto err_rq;
2749
2750         INIT_DELAYED_WORK(&vi->refill, refill_work);
2751         for (i = 0; i < vi->max_queue_pairs; i++) {
2752                 vi->rq[i].pages = NULL;
2753                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2754                                napi_weight);
2755                 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2756                                   napi_tx ? napi_weight : 0);
2757
2758                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2759                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2760                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2761
2762                 u64_stats_init(&vi->rq[i].stats.syncp);
2763                 u64_stats_init(&vi->sq[i].stats.syncp);
2764         }
2765
2766         return 0;
2767
2768 err_rq:
2769         kfree(vi->sq);
2770 err_sq:
2771         kfree(vi->ctrl);
2772 err_ctrl:
2773         return -ENOMEM;
2774 }
2775
2776 static int init_vqs(struct virtnet_info *vi)
2777 {
2778         int ret;
2779
2780         /* Allocate send & receive queues */
2781         ret = virtnet_alloc_queues(vi);
2782         if (ret)
2783                 goto err;
2784
2785         ret = virtnet_find_vqs(vi);
2786         if (ret)
2787                 goto err_free;
2788
2789         get_online_cpus();
2790         virtnet_set_affinity(vi);
2791         put_online_cpus();
2792
2793         return 0;
2794
2795 err_free:
2796         virtnet_free_queues(vi);
2797 err:
2798         return ret;
2799 }
2800
2801 #ifdef CONFIG_SYSFS
2802 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2803                 char *buf)
2804 {
2805         struct virtnet_info *vi = netdev_priv(queue->dev);
2806         unsigned int queue_index = get_netdev_rx_queue_index(queue);
2807         unsigned int headroom = virtnet_get_headroom(vi);
2808         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
2809         struct ewma_pkt_len *avg;
2810
2811         BUG_ON(queue_index >= vi->max_queue_pairs);
2812         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2813         return sprintf(buf, "%u\n",
2814                        get_mergeable_buf_len(&vi->rq[queue_index], avg,
2815                                        SKB_DATA_ALIGN(headroom + tailroom)));
2816 }
2817
2818 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2819         __ATTR_RO(mergeable_rx_buffer_size);
2820
2821 static struct attribute *virtio_net_mrg_rx_attrs[] = {
2822         &mergeable_rx_buffer_size_attribute.attr,
2823         NULL
2824 };
2825
2826 static const struct attribute_group virtio_net_mrg_rx_group = {
2827         .name = "virtio_net",
2828         .attrs = virtio_net_mrg_rx_attrs
2829 };
2830 #endif
2831
2832 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2833                                     unsigned int fbit,
2834                                     const char *fname, const char *dname)
2835 {
2836         if (!virtio_has_feature(vdev, fbit))
2837                 return false;
2838
2839         dev_err(&vdev->dev, "device advertises feature %s but not %s",
2840                 fname, dname);
2841
2842         return true;
2843 }
2844
2845 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
2846         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2847
2848 static bool virtnet_validate_features(struct virtio_device *vdev)
2849 {
2850         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2851             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2852                              "VIRTIO_NET_F_CTRL_VQ") ||
2853              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2854                              "VIRTIO_NET_F_CTRL_VQ") ||
2855              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2856                              "VIRTIO_NET_F_CTRL_VQ") ||
2857              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2858              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2859                              "VIRTIO_NET_F_CTRL_VQ"))) {
2860                 return false;
2861         }
2862
2863         return true;
2864 }
2865
2866 #define MIN_MTU ETH_MIN_MTU
2867 #define MAX_MTU ETH_MAX_MTU
2868
2869 static int virtnet_validate(struct virtio_device *vdev)
2870 {
2871         if (!vdev->config->get) {
2872                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2873                         __func__);
2874                 return -EINVAL;
2875         }
2876
2877         if (!virtnet_validate_features(vdev))
2878                 return -EINVAL;
2879
2880         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2881                 int mtu = virtio_cread16(vdev,
2882                                          offsetof(struct virtio_net_config,
2883                                                   mtu));
2884                 if (mtu < MIN_MTU)
2885                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2886         }
2887
2888         return 0;
2889 }
2890
2891 static int virtnet_probe(struct virtio_device *vdev)
2892 {
2893         int i, err = -ENOMEM;
2894         struct net_device *dev;
2895         struct virtnet_info *vi;
2896         u16 max_queue_pairs;
2897         int mtu;
2898
2899         /* Find if host supports multiqueue virtio_net device */
2900         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2901                                    struct virtio_net_config,
2902                                    max_virtqueue_pairs, &max_queue_pairs);
2903
2904         /* We need at least 2 queue's */
2905         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
2906             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
2907             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2908                 max_queue_pairs = 1;
2909
2910         /* Allocate ourselves a network device with room for our info */
2911         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
2912         if (!dev)
2913                 return -ENOMEM;
2914
2915         /* Set up network device as normal. */
2916         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
2917         dev->netdev_ops = &virtnet_netdev;
2918         dev->features = NETIF_F_HIGHDMA;
2919
2920         dev->ethtool_ops = &virtnet_ethtool_ops;
2921         SET_NETDEV_DEV(dev, &vdev->dev);
2922
2923         /* Do we support "hardware" checksums? */
2924         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
2925                 /* This opens up the world of extra features. */
2926                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2927                 if (csum)
2928                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2929
2930                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
2931                         dev->hw_features |= NETIF_F_TSO
2932                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
2933                 }
2934                 /* Individual feature bits: what can host handle? */
2935                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
2936                         dev->hw_features |= NETIF_F_TSO;
2937                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
2938                         dev->hw_features |= NETIF_F_TSO6;
2939                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
2940                         dev->hw_features |= NETIF_F_TSO_ECN;
2941
2942                 dev->features |= NETIF_F_GSO_ROBUST;
2943
2944                 if (gso)
2945                         dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
2946                 /* (!csum && gso) case will be fixed by register_netdev() */
2947         }
2948         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
2949                 dev->features |= NETIF_F_RXCSUM;
2950
2951         dev->vlan_features = dev->features;
2952
2953         /* MTU range: 68 - 65535 */
2954         dev->min_mtu = MIN_MTU;
2955         dev->max_mtu = MAX_MTU;
2956
2957         /* Configuration may specify what MAC to use.  Otherwise random. */
2958         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
2959                 virtio_cread_bytes(vdev,
2960                                    offsetof(struct virtio_net_config, mac),
2961                                    dev->dev_addr, dev->addr_len);
2962         else
2963                 eth_hw_addr_random(dev);
2964
2965         /* Set up our device-specific information */
2966         vi = netdev_priv(dev);
2967         vi->dev = dev;
2968         vi->vdev = vdev;
2969         vdev->priv = vi;
2970
2971         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
2972
2973         /* If we can receive ANY GSO packets, we must allocate large ones. */
2974         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2975             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2976             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
2977             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
2978                 vi->big_packets = true;
2979
2980         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
2981                 vi->mergeable_rx_bufs = true;
2982
2983         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
2984             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2985                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2986         else
2987                 vi->hdr_len = sizeof(struct virtio_net_hdr);
2988
2989         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
2990             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2991                 vi->any_header_sg = true;
2992
2993         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2994                 vi->has_cvq = true;
2995
2996         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2997                 mtu = virtio_cread16(vdev,
2998                                      offsetof(struct virtio_net_config,
2999                                               mtu));
3000                 if (mtu < dev->min_mtu) {
3001                         /* Should never trigger: MTU was previously validated
3002                          * in virtnet_validate.
3003                          */
3004                         dev_err(&vdev->dev, "device MTU appears to have changed "
3005                                 "it is now %d < %d", mtu, dev->min_mtu);
3006                         goto free;
3007                 }
3008
3009                 dev->mtu = mtu;
3010                 dev->max_mtu = mtu;
3011
3012                 /* TODO: size buffers correctly in this case. */
3013                 if (dev->mtu > ETH_DATA_LEN)
3014                         vi->big_packets = true;
3015         }
3016
3017         if (vi->any_header_sg)
3018                 dev->needed_headroom = vi->hdr_len;
3019
3020         /* Enable multiqueue by default */
3021         if (num_online_cpus() >= max_queue_pairs)
3022                 vi->curr_queue_pairs = max_queue_pairs;
3023         else
3024                 vi->curr_queue_pairs = num_online_cpus();
3025         vi->max_queue_pairs = max_queue_pairs;
3026
3027         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
3028         err = init_vqs(vi);
3029         if (err)
3030                 goto free;
3031
3032 #ifdef CONFIG_SYSFS
3033         if (vi->mergeable_rx_bufs)
3034                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
3035 #endif
3036         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
3037         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
3038
3039         virtnet_init_settings(dev);
3040
3041         if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3042                 vi->failover = net_failover_create(vi->dev);
3043                 if (IS_ERR(vi->failover)) {
3044                         err = PTR_ERR(vi->failover);
3045                         goto free_vqs;
3046                 }
3047         }
3048
3049         err = register_netdev(dev);
3050         if (err) {
3051                 pr_debug("virtio_net: registering device failed\n");
3052                 goto free_failover;
3053         }
3054
3055         virtio_device_ready(vdev);
3056
3057         err = virtnet_cpu_notif_add(vi);
3058         if (err) {
3059                 pr_debug("virtio_net: registering cpu notifier failed\n");
3060                 goto free_unregister_netdev;
3061         }
3062
3063         virtnet_set_queues(vi, vi->curr_queue_pairs);
3064
3065         /* Assume link up if device can't report link status,
3066            otherwise get link status from config. */
3067         netif_carrier_off(dev);
3068         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
3069                 schedule_work(&vi->config_work);
3070         } else {
3071                 vi->status = VIRTIO_NET_S_LINK_UP;
3072                 virtnet_update_settings(vi);
3073                 netif_carrier_on(dev);
3074         }
3075
3076         for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
3077                 if (virtio_has_feature(vi->vdev, guest_offloads[i]))
3078                         set_bit(guest_offloads[i], &vi->guest_offloads);
3079
3080         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
3081                  dev->name, max_queue_pairs);
3082
3083         return 0;
3084
3085 free_unregister_netdev:
3086         vi->vdev->config->reset(vdev);
3087
3088         unregister_netdev(dev);
3089 free_failover:
3090         net_failover_destroy(vi->failover);
3091 free_vqs:
3092         cancel_delayed_work_sync(&vi->refill);
3093         free_receive_page_frags(vi);
3094         virtnet_del_vqs(vi);
3095 free:
3096         free_netdev(dev);
3097         return err;
3098 }
3099
3100 static void remove_vq_common(struct virtnet_info *vi)
3101 {
3102         vi->vdev->config->reset(vi->vdev);
3103
3104         /* Free unused buffers in both send and recv, if any. */
3105         free_unused_bufs(vi);
3106
3107         free_receive_bufs(vi);
3108
3109         free_receive_page_frags(vi);
3110
3111         virtnet_del_vqs(vi);
3112 }
3113
3114 static void virtnet_remove(struct virtio_device *vdev)
3115 {
3116         struct virtnet_info *vi = vdev->priv;
3117
3118         virtnet_cpu_notif_remove(vi);
3119
3120         /* Make sure no work handler is accessing the device. */
3121         flush_work(&vi->config_work);
3122
3123         unregister_netdev(vi->dev);
3124
3125         net_failover_destroy(vi->failover);
3126
3127         remove_vq_common(vi);
3128
3129         free_netdev(vi->dev);
3130 }
3131
3132 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
3133 {
3134         struct virtnet_info *vi = vdev->priv;
3135
3136         virtnet_cpu_notif_remove(vi);
3137         virtnet_freeze_down(vdev);
3138         remove_vq_common(vi);
3139
3140         return 0;
3141 }
3142
3143 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
3144 {
3145         struct virtnet_info *vi = vdev->priv;
3146         int err;
3147
3148         err = virtnet_restore_up(vdev);
3149         if (err)
3150                 return err;
3151         virtnet_set_queues(vi, vi->curr_queue_pairs);
3152
3153         err = virtnet_cpu_notif_add(vi);
3154         if (err)
3155                 return err;
3156
3157         return 0;
3158 }
3159
3160 static struct virtio_device_id id_table[] = {
3161         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
3162         { 0 },
3163 };
3164
3165 #define VIRTNET_FEATURES \
3166         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
3167         VIRTIO_NET_F_MAC, \
3168         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
3169         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
3170         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
3171         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
3172         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
3173         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
3174         VIRTIO_NET_F_CTRL_MAC_ADDR, \
3175         VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
3176         VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
3177
3178 static unsigned int features[] = {
3179         VIRTNET_FEATURES,
3180 };
3181
3182 static unsigned int features_legacy[] = {
3183         VIRTNET_FEATURES,
3184         VIRTIO_NET_F_GSO,
3185         VIRTIO_F_ANY_LAYOUT,
3186 };
3187
3188 static struct virtio_driver virtio_net_driver = {
3189         .feature_table = features,
3190         .feature_table_size = ARRAY_SIZE(features),
3191         .feature_table_legacy = features_legacy,
3192         .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
3193         .driver.name =  KBUILD_MODNAME,
3194         .driver.owner = THIS_MODULE,
3195         .id_table =     id_table,
3196         .validate =     virtnet_validate,
3197         .probe =        virtnet_probe,
3198         .remove =       virtnet_remove,
3199         .config_changed = virtnet_config_changed,
3200 #ifdef CONFIG_PM_SLEEP
3201         .freeze =       virtnet_freeze,
3202         .restore =      virtnet_restore,
3203 #endif
3204 };
3205
3206 static __init int virtio_net_driver_init(void)
3207 {
3208         int ret;
3209
3210         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
3211                                       virtnet_cpu_online,
3212                                       virtnet_cpu_down_prep);
3213         if (ret < 0)
3214                 goto out;
3215         virtionet_online = ret;
3216         ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
3217                                       NULL, virtnet_cpu_dead);
3218         if (ret)
3219                 goto err_dead;
3220
3221         ret = register_virtio_driver(&virtio_net_driver);
3222         if (ret)
3223                 goto err_virtio;
3224         return 0;
3225 err_virtio:
3226         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3227 err_dead:
3228         cpuhp_remove_multi_state(virtionet_online);
3229 out:
3230         return ret;
3231 }
3232 module_init(virtio_net_driver_init);
3233
3234 static __exit void virtio_net_driver_exit(void)
3235 {
3236         unregister_virtio_driver(&virtio_net_driver);
3237         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3238         cpuhp_remove_multi_state(virtionet_online);
3239 }
3240 module_exit(virtio_net_driver_exit);
3241
3242 MODULE_DEVICE_TABLE(virtio, id_table);
3243 MODULE_DESCRIPTION("Virtio network driver");
3244 MODULE_LICENSE("GPL");