drivers/net/virtio_net.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* A network driver using virtio.
   3  *
   4  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
   5  */
   6 //#define DEBUG
   7 #include <linux/netdevice.h>
   8 #include <linux/etherdevice.h>
   9 #include <linux/ethtool.h>
  10 #include <linux/module.h>
  11 #include <linux/virtio.h>
  12 #include <linux/virtio_net.h>
  13 #include <linux/bpf.h>
  14 #include <linux/bpf_trace.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/if_vlan.h>
  17 #include <linux/slab.h>
  18 #include <linux/cpu.h>
  19 #include <linux/average.h>
  20 #include <linux/filter.h>
  21 #include <linux/kernel.h>
  22 #include <net/route.h>
  23 #include <net/xdp.h>
  24 #include <net/net_failover.h>
  25
  26 static int napi_weight = NAPI_POLL_WEIGHT;
  27 module_param(napi_weight, int, 0444);
  28
  29 static bool csum = true, gso = true, napi_tx = true;
  30 module_param(csum, bool, 0444);
  31 module_param(gso, bool, 0444);
  32 module_param(napi_tx, bool, 0644);
  33
  34 /* FIXME: MTU in config. */
  35 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  36 #define GOOD_COPY_LEN   128
  37
  38 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
  39
  40 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
  41 #define VIRTIO_XDP_HEADROOM 256
  42
  43 /* Separating two types of XDP xmit */
  44 #define VIRTIO_XDP_TX           BIT(0)
  45 #define VIRTIO_XDP_REDIR        BIT(1)
  46
  47 #define VIRTIO_XDP_FLAG BIT(0)
  48
  49 /* RX packet size EWMA. The average packet size is used to determine the packet
  50  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  51  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  52  * term, transient changes in packet size.
  53  */
  54 DECLARE_EWMA(pkt_len, 0, 64)
  55
  56 #define VIRTNET_DRIVER_VERSION "1.0.0"
  57
  58 static const unsigned long guest_offloads[] = {
  59         VIRTIO_NET_F_GUEST_TSO4,
  60         VIRTIO_NET_F_GUEST_TSO6,
  61         VIRTIO_NET_F_GUEST_ECN,
  62         VIRTIO_NET_F_GUEST_UFO,
  63         VIRTIO_NET_F_GUEST_CSUM
  64 };
  65
  66 #define GUEST_OFFLOAD_LRO_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
  67                                 (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
  68                                 (1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
  69                                 (1ULL << VIRTIO_NET_F_GUEST_UFO))
  70
  71 struct virtnet_stat_desc {
  72         char desc[ETH_GSTRING_LEN];
  73         size_t offset;
  74 };
  75
  76 struct virtnet_sq_stats {
  77         struct u64_stats_sync syncp;
  78         u64 packets;
  79         u64 bytes;
  80         u64 xdp_tx;
  81         u64 xdp_tx_drops;
  82         u64 kicks;
  83 };
  84
  85 struct virtnet_rq_stats {
  86         struct u64_stats_sync syncp;
  87         u64 packets;
  88         u64 bytes;
  89         u64 drops;
  90         u64 xdp_packets;
  91         u64 xdp_tx;
  92         u64 xdp_redirects;
  93         u64 xdp_drops;
  94         u64 kicks;
  95 };
  96
  97 #define VIRTNET_SQ_STAT(m)      offsetof(struct virtnet_sq_stats, m)
  98 #define VIRTNET_RQ_STAT(m)      offsetof(struct virtnet_rq_stats, m)
  99
 100 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
 101         { "packets",            VIRTNET_SQ_STAT(packets) },
 102         { "bytes",              VIRTNET_SQ_STAT(bytes) },
 103         { "xdp_tx",             VIRTNET_SQ_STAT(xdp_tx) },
 104         { "xdp_tx_drops",       VIRTNET_SQ_STAT(xdp_tx_drops) },
 105         { "kicks",              VIRTNET_SQ_STAT(kicks) },
 106 };
 107
 108 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
 109         { "packets",            VIRTNET_RQ_STAT(packets) },
 110         { "bytes",              VIRTNET_RQ_STAT(bytes) },
 111         { "drops",              VIRTNET_RQ_STAT(drops) },
 112         { "xdp_packets",        VIRTNET_RQ_STAT(xdp_packets) },
 113         { "xdp_tx",             VIRTNET_RQ_STAT(xdp_tx) },
 114         { "xdp_redirects",      VIRTNET_RQ_STAT(xdp_redirects) },
 115         { "xdp_drops",          VIRTNET_RQ_STAT(xdp_drops) },
 116         { "kicks",              VIRTNET_RQ_STAT(kicks) },
 117 };
 118
 119 #define VIRTNET_SQ_STATS_LEN    ARRAY_SIZE(virtnet_sq_stats_desc)
 120 #define VIRTNET_RQ_STATS_LEN    ARRAY_SIZE(virtnet_rq_stats_desc)
 121
 122 /* Internal representation of a send virtqueue */
 123 struct send_queue {
 124         /* Virtqueue associated with this send _queue */
 125         struct virtqueue *vq;
 126
 127         /* TX: fragments + linear part + virtio header */
 128         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 129
 130         /* Name of the send queue: output.$index */
 131         char name[40];
 132
 133         struct virtnet_sq_stats stats;
 134
 135         struct napi_struct napi;
 136 };
 137
 138 /* Internal representation of a receive virtqueue */
 139 struct receive_queue {
 140         /* Virtqueue associated with this receive_queue */
 141         struct virtqueue *vq;
 142
 143         struct napi_struct napi;
 144
 145         struct bpf_prog __rcu *xdp_prog;
 146
 147         struct virtnet_rq_stats stats;
 148
 149         /* Chain pages by the private ptr. */
 150         struct page *pages;
 151
 152         /* Average packet length for mergeable receive buffers. */
 153         struct ewma_pkt_len mrg_avg_pkt_len;
 154
 155         /* Page frag for packet buffer allocation. */
 156         struct page_frag alloc_frag;
 157
 158         /* RX: fragments + linear part + virtio header */
 159         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 160
 161         /* Min single buffer size for mergeable buffers case. */
 162         unsigned int min_buf_len;
 163
 164         /* Name of this receive queue: input.$index */
 165         char name[40];
 166
 167         struct xdp_rxq_info xdp_rxq;
 168 };
 169
 170 /* Control VQ buffers: protected by the rtnl lock */
 171 struct control_buf {
 172         struct virtio_net_ctrl_hdr hdr;
 173         virtio_net_ctrl_ack status;
 174         struct virtio_net_ctrl_mq mq;
 175         u8 promisc;
 176         u8 allmulti;
 177         __virtio16 vid;
 178         __virtio64 offloads;
 179 };
 180
 181 struct virtnet_info {
 182         struct virtio_device *vdev;
 183         struct virtqueue *cvq;
 184         struct net_device *dev;
 185         struct send_queue *sq;
 186         struct receive_queue *rq;
 187         unsigned int status;
 188
 189         /* Max # of queue pairs supported by the device */
 190         u16 max_queue_pairs;
 191
 192         /* # of queue pairs currently used by the driver */
 193         u16 curr_queue_pairs;
 194
 195         /* # of XDP queue pairs currently used by the driver */
 196         u16 xdp_queue_pairs;
 197
 198         /* I like... big packets and I cannot lie! */
 199         bool big_packets;
 200
 201         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 202         bool mergeable_rx_bufs;
 203
 204         /* Has control virtqueue */
 205         bool has_cvq;
 206
 207         /* Host can handle any s/g split between our header and packet data */
 208         bool any_header_sg;
 209
 210         /* Packet virtio header size */
 211         u8 hdr_len;
 212
 213         /* Work struct for refilling if we run low on memory. */
 214         struct delayed_work refill;
 215
 216         /* Work struct for config space updates */
 217         struct work_struct config_work;
 218
 219         /* Does the affinity hint is set for virtqueues? */
 220         bool affinity_hint_set;
 221
 222         /* CPU hotplug instances for online & dead */
 223         struct hlist_node node;
 224         struct hlist_node node_dead;
 225
 226         struct control_buf *ctrl;
 227
 228         /* Ethtool settings */
 229         u8 duplex;
 230         u32 speed;
 231
 232         unsigned long guest_offloads;
 233         unsigned long guest_offloads_capable;
 234
 235         /* failover when STANDBY feature enabled */
 236         struct failover *failover;
 237 };
 238
 239 struct padded_vnet_hdr {
 240         struct virtio_net_hdr_mrg_rxbuf hdr;
 241         /*
 242          * hdr is in a separate sg buffer, and data sg buffer shares same page
 243          * with this header sg. This padding makes next sg 16 byte aligned
 244          * after the header.
 245          */
 246         char padding[4];
 247 };
 248
 249 static bool is_xdp_frame(void *ptr)
 250 {
 251         return (unsigned long)ptr & VIRTIO_XDP_FLAG;
 252 }
 253
 254 static void *xdp_to_ptr(struct xdp_frame *ptr)
 255 {
 256         return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
 257 }
 258
 259 static struct xdp_frame *ptr_to_xdp(void *ptr)
 260 {
 261         return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
 262 }
 263
 264 /* Converting between virtqueue no. and kernel tx/rx queue no.
 265  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 266  */
 267 static int vq2txq(struct virtqueue *vq)
 268 {
 269         return (vq->index - 1) / 2;
 270 }
 271
 272 static int txq2vq(int txq)
 273 {
 274         return txq * 2 + 1;
 275 }
 276
 277 static int vq2rxq(struct virtqueue *vq)
 278 {
 279         return vq->index / 2;
 280 }
 281
 282 static int rxq2vq(int rxq)
 283 {
 284         return rxq * 2;
 285 }
 286
 287 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 288 {
 289         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 290 }
 291
 292 /*
 293  * private is used to chain pages for big packets, put the whole
 294  * most recent used list in the beginning for reuse
 295  */
 296 static void give_pages(struct receive_queue *rq, struct page *page)
 297 {
 298         struct page *end;
 299
 300         /* Find end of list, sew whole thing into vi->rq.pages. */
 301         for (end = page; end->private; end = (struct page *)end->private);
 302         end->private = (unsigned long)rq->pages;
 303         rq->pages = page;
 304 }
 305
 306 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 307 {
 308         struct page *p = rq->pages;
 309
 310         if (p) {
 311                 rq->pages = (struct page *)p->private;
 312                 /* clear private here, it is used to chain pages */
 313                 p->private = 0;
 314         } else
 315                 p = alloc_page(gfp_mask);
 316         return p;
 317 }
 318
 319 static void virtqueue_napi_schedule(struct napi_struct *napi,
 320                                     struct virtqueue *vq)
 321 {
 322         if (napi_schedule_prep(napi)) {
 323                 virtqueue_disable_cb(vq);
 324                 __napi_schedule(napi);
 325         }
 326 }
 327
 328 static void virtqueue_napi_complete(struct napi_struct *napi,
 329                                     struct virtqueue *vq, int processed)
 330 {
 331         int opaque;
 332
 333         opaque = virtqueue_enable_cb_prepare(vq);
 334         if (napi_complete_done(napi, processed)) {
 335                 if (unlikely(virtqueue_poll(vq, opaque)))
 336                         virtqueue_napi_schedule(napi, vq);
 337         } else {
 338                 virtqueue_disable_cb(vq);
 339         }
 340 }
 341
 342 static void skb_xmit_done(struct virtqueue *vq)
 343 {
 344         struct virtnet_info *vi = vq->vdev->priv;
 345         struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
 346
 347         /* Suppress further interrupts. */
 348         virtqueue_disable_cb(vq);
 349
 350         if (napi->weight)
 351                 virtqueue_napi_schedule(napi, vq);
 352         else
 353                 /* We were probably waiting for more output buffers. */
 354                 netif_wake_subqueue(vi->dev, vq2txq(vq));
 355 }
 356
 357 #define MRG_CTX_HEADER_SHIFT 22
 358 static void *mergeable_len_to_ctx(unsigned int truesize,
 359                                   unsigned int headroom)
 360 {
 361         return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
 362 }
 363
 364 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
 365 {
 366         return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
 367 }
 368
 369 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
 370 {
 371         return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
 372 }
 373
 374 /* Called from bottom half context */
 375 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 376                                    struct receive_queue *rq,
 377                                    struct page *page, unsigned int offset,
 378                                    unsigned int len, unsigned int truesize,
 379                                    bool hdr_valid, unsigned int metasize)
 380 {
 381         struct sk_buff *skb;
 382         struct virtio_net_hdr_mrg_rxbuf *hdr;
 383         unsigned int copy, hdr_len, hdr_padded_len;
 384         char *p;
 385
 386         p = page_address(page) + offset;
 387
 388         /* copy small packet so we can reuse these pages for small data */
 389         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 390         if (unlikely(!skb))
 391                 return NULL;
 392
 393         hdr = skb_vnet_hdr(skb);
 394
 395         hdr_len = vi->hdr_len;
 396         if (vi->mergeable_rx_bufs)
 397                 hdr_padded_len = sizeof(*hdr);
 398         else
 399                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 400
 401         /* hdr_valid means no XDP, so we can copy the vnet header */
 402         if (hdr_valid)
 403                 memcpy(hdr, p, hdr_len);
 404
 405         len -= hdr_len;
 406         offset += hdr_padded_len;
 407         p += hdr_padded_len;
 408
 409         copy = len;
 410         if (copy > skb_tailroom(skb))
 411                 copy = skb_tailroom(skb);
 412         skb_put_data(skb, p, copy);
 413
 414         if (metasize) {
 415                 __skb_pull(skb, metasize);
 416                 skb_metadata_set(skb, metasize);
 417         }
 418
 419         len -= copy;
 420         offset += copy;
 421
 422         if (vi->mergeable_rx_bufs) {
 423                 if (len)
 424                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 425                 else
 426                         put_page(page);
 427                 return skb;
 428         }
 429
 430         /*
 431          * Verify that we can indeed put this data into a skb.
 432          * This is here to handle cases when the device erroneously
 433          * tries to receive more than is possible. This is usually
 434          * the case of a broken device.
 435          */
 436         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 437                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 438                 dev_kfree_skb(skb);
 439                 return NULL;
 440         }
 441         BUG_ON(offset >= PAGE_SIZE);
 442         while (len) {
 443                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 444                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 445                                 frag_size, truesize);
 446                 len -= frag_size;
 447                 page = (struct page *)page->private;
 448                 offset = 0;
 449         }
 450
 451         if (page)
 452                 give_pages(rq, page);
 453
 454         return skb;
 455 }
 456
 457 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
 458                                    struct send_queue *sq,
 459                                    struct xdp_frame *xdpf)
 460 {
 461         struct virtio_net_hdr_mrg_rxbuf *hdr;
 462         int err;
 463
 464         if (unlikely(xdpf->headroom < vi->hdr_len))
 465                 return -EOVERFLOW;
 466
 467         /* Make room for virtqueue hdr (also change xdpf->headroom?) */
 468         xdpf->data -= vi->hdr_len;
 469         /* Zero header and leave csum up to XDP layers */
 470         hdr = xdpf->data;
 471         memset(hdr, 0, vi->hdr_len);
 472         xdpf->len   += vi->hdr_len;
 473
 474         sg_init_one(sq->sg, xdpf->data, xdpf->len);
 475
 476         err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
 477                                    GFP_ATOMIC);
 478         if (unlikely(err))
 479                 return -ENOSPC; /* Caller handle free/refcnt */
 480
 481         return 0;
 482 }
 483
 484 static struct send_queue *virtnet_xdp_sq(struct virtnet_info *vi)
 485 {
 486         unsigned int qp;
 487
 488         qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
 489         return &vi->sq[qp];
 490 }
 491
 492 static int virtnet_xdp_xmit(struct net_device *dev,
 493                             int n, struct xdp_frame **frames, u32 flags)
 494 {
 495         struct virtnet_info *vi = netdev_priv(dev);
 496         struct receive_queue *rq = vi->rq;
 497         struct bpf_prog *xdp_prog;
 498         struct send_queue *sq;
 499         unsigned int len;
 500         int packets = 0;
 501         int bytes = 0;
 502         int drops = 0;
 503         int kicks = 0;
 504         int ret, err;
 505         void *ptr;
 506         int i;
 507
 508         /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
 509          * indicate XDP resources have been successfully allocated.
 510          */
 511         xdp_prog = rcu_access_pointer(rq->xdp_prog);
 512         if (!xdp_prog)
 513                 return -ENXIO;
 514
 515         sq = virtnet_xdp_sq(vi);
 516
 517         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
 518                 ret = -EINVAL;
 519                 drops = n;
 520                 goto out;
 521         }
 522
 523         /* Free up any pending old buffers before queueing new ones. */
 524         while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 525                 if (likely(is_xdp_frame(ptr))) {
 526                         struct xdp_frame *frame = ptr_to_xdp(ptr);
 527
 528                         bytes += frame->len;
 529                         xdp_return_frame(frame);
 530                 } else {
 531                         struct sk_buff *skb = ptr;
 532
 533                         bytes += skb->len;
 534                         napi_consume_skb(skb, false);
 535                 }
 536                 packets++;
 537         }
 538
 539         for (i = 0; i < n; i++) {
 540                 struct xdp_frame *xdpf = frames[i];
 541
 542                 err = __virtnet_xdp_xmit_one(vi, sq, xdpf);
 543                 if (err) {
 544                         xdp_return_frame_rx_napi(xdpf);
 545                         drops++;
 546                 }
 547         }
 548         ret = n - drops;
 549
 550         if (flags & XDP_XMIT_FLUSH) {
 551                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
 552                         kicks = 1;
 553         }
 554 out:
 555         u64_stats_update_begin(&sq->stats.syncp);
 556         sq->stats.bytes += bytes;
 557         sq->stats.packets += packets;
 558         sq->stats.xdp_tx += n;
 559         sq->stats.xdp_tx_drops += drops;
 560         sq->stats.kicks += kicks;
 561         u64_stats_update_end(&sq->stats.syncp);
 562
 563         return ret;
 564 }
 565
 566 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
 567 {
 568         return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
 569 }
 570
 571 /* We copy the packet for XDP in the following cases:
 572  *
 573  * 1) Packet is scattered across multiple rx buffers.
 574  * 2) Headroom space is insufficient.
 575  *
 576  * This is inefficient but it's a temporary condition that
 577  * we hit right after XDP is enabled and until queue is refilled
 578  * with large buffers with sufficient headroom - so it should affect
 579  * at most queue size packets.
 580  * Afterwards, the conditions to enable
 581  * XDP should preclude the underlying device from sending packets
 582  * across multiple buffers (num_buf > 1), and we make sure buffers
 583  * have enough headroom.
 584  */
 585 static struct page *xdp_linearize_page(struct receive_queue *rq,
 586                                        u16 *num_buf,
 587                                        struct page *p,
 588                                        int offset,
 589                                        int page_off,
 590                                        unsigned int *len)
 591 {
 592         struct page *page = alloc_page(GFP_ATOMIC);
 593
 594         if (!page)
 595                 return NULL;
 596
 597         memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
 598         page_off += *len;
 599
 600         while (--*num_buf) {
 601                 int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 602                 unsigned int buflen;
 603                 void *buf;
 604                 int off;
 605
 606                 buf = virtqueue_get_buf(rq->vq, &buflen);
 607                 if (unlikely(!buf))
 608                         goto err_buf;
 609
 610                 p = virt_to_head_page(buf);
 611                 off = buf - page_address(p);
 612
 613                 /* guard against a misconfigured or uncooperative backend that
 614                  * is sending packet larger than the MTU.
 615                  */
 616                 if ((page_off + buflen + tailroom) > PAGE_SIZE) {
 617                         put_page(p);
 618                         goto err_buf;
 619                 }
 620
 621                 memcpy(page_address(page) + page_off,
 622                        page_address(p) + off, buflen);
 623                 page_off += buflen;
 624                 put_page(p);
 625         }
 626
 627         /* Headroom does not contribute to packet length */
 628         *len = page_off - VIRTIO_XDP_HEADROOM;
 629         return page;
 630 err_buf:
 631         __free_pages(page, 0);
 632         return NULL;
 633 }
 634
 635 static struct sk_buff *receive_small(struct net_device *dev,
 636                                      struct virtnet_info *vi,
 637                                      struct receive_queue *rq,
 638                                      void *buf, void *ctx,
 639                                      unsigned int len,
 640                                      unsigned int *xdp_xmit,
 641                                      struct virtnet_rq_stats *stats)
 642 {
 643         struct sk_buff *skb;
 644         struct bpf_prog *xdp_prog;
 645         unsigned int xdp_headroom = (unsigned long)ctx;
 646         unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
 647         unsigned int headroom = vi->hdr_len + header_offset;
 648         unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 649                               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 650         struct page *page = virt_to_head_page(buf);
 651         unsigned int delta = 0;
 652         struct page *xdp_page;
 653         int err;
 654         unsigned int metasize = 0;
 655
 656         len -= vi->hdr_len;
 657         stats->bytes += len;
 658
 659         rcu_read_lock();
 660         xdp_prog = rcu_dereference(rq->xdp_prog);
 661         if (xdp_prog) {
 662                 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
 663                 struct xdp_frame *xdpf;
 664                 struct xdp_buff xdp;
 665                 void *orig_data;
 666                 u32 act;
 667
 668                 if (unlikely(hdr->hdr.gso_type))
 669                         goto err_xdp;
 670
 671                 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
 672                         int offset = buf - page_address(page) + header_offset;
 673                         unsigned int tlen = len + vi->hdr_len;
 674                         u16 num_buf = 1;
 675
 676                         xdp_headroom = virtnet_get_headroom(vi);
 677                         header_offset = VIRTNET_RX_PAD + xdp_headroom;
 678                         headroom = vi->hdr_len + header_offset;
 679                         buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 680                                  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 681                         xdp_page = xdp_linearize_page(rq, &num_buf, page,
 682                                                       offset, header_offset,
 683                                                       &tlen);
 684                         if (!xdp_page)
 685                                 goto err_xdp;
 686
 687                         buf = page_address(xdp_page);
 688                         put_page(page);
 689                         page = xdp_page;
 690                 }
 691
 692                 xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
 693                 xdp.data = xdp.data_hard_start + xdp_headroom;
 694                 xdp.data_end = xdp.data + len;
 695                 xdp.data_meta = xdp.data;
 696                 xdp.rxq = &rq->xdp_rxq;
 697                 xdp.frame_sz = buflen;
 698                 orig_data = xdp.data;
 699                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 700                 stats->xdp_packets++;
 701
 702                 switch (act) {
 703                 case XDP_PASS:
 704                         /* Recalculate length in case bpf program changed it */
 705                         delta = orig_data - xdp.data;
 706                         len = xdp.data_end - xdp.data;
 707                         metasize = xdp.data - xdp.data_meta;
 708                         break;
 709                 case XDP_TX:
 710                         stats->xdp_tx++;
 711                         xdpf = xdp_convert_buff_to_frame(&xdp);
 712                         if (unlikely(!xdpf))
 713                                 goto err_xdp;
 714                         err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 715                         if (unlikely(err < 0)) {
 716                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 717                                 goto err_xdp;
 718                         }
 719                         *xdp_xmit |= VIRTIO_XDP_TX;
 720                         rcu_read_unlock();
 721                         goto xdp_xmit;
 722                 case XDP_REDIRECT:
 723                         stats->xdp_redirects++;
 724                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
 725                         if (err)
 726                                 goto err_xdp;
 727                         *xdp_xmit |= VIRTIO_XDP_REDIR;
 728                         rcu_read_unlock();
 729                         goto xdp_xmit;
 730                 default:
 731                         bpf_warn_invalid_xdp_action(act);
 732                         fallthrough;
 733                 case XDP_ABORTED:
 734                         trace_xdp_exception(vi->dev, xdp_prog, act);
 735                 case XDP_DROP:
 736                         goto err_xdp;
 737                 }
 738         }
 739         rcu_read_unlock();
 740
 741         skb = build_skb(buf, buflen);
 742         if (!skb) {
 743                 put_page(page);
 744                 goto err;
 745         }
 746         skb_reserve(skb, headroom - delta);
 747         skb_put(skb, len);
 748         if (!xdp_prog) {
 749                 buf += header_offset;
 750                 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
 751         } /* keep zeroed vnet hdr since XDP is loaded */
 752
 753         if (metasize)
 754                 skb_metadata_set(skb, metasize);
 755
 756 err:
 757         return skb;
 758
 759 err_xdp:
 760         rcu_read_unlock();
 761         stats->xdp_drops++;
 762         stats->drops++;
 763         put_page(page);
 764 xdp_xmit:
 765         return NULL;
 766 }
 767
 768 static struct sk_buff *receive_big(struct net_device *dev,
 769                                    struct virtnet_info *vi,
 770                                    struct receive_queue *rq,
 771                                    void *buf,
 772                                    unsigned int len,
 773                                    struct virtnet_rq_stats *stats)
 774 {
 775         struct page *page = buf;
 776         struct sk_buff *skb =
 777                 page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0);
 778
 779         stats->bytes += len - vi->hdr_len;
 780         if (unlikely(!skb))
 781                 goto err;
 782
 783         return skb;
 784
 785 err:
 786         stats->drops++;
 787         give_pages(rq, page);
 788         return NULL;
 789 }
 790
 791 static struct sk_buff *receive_mergeable(struct net_device *dev,
 792                                          struct virtnet_info *vi,
 793                                          struct receive_queue *rq,
 794                                          void *buf,
 795                                          void *ctx,
 796                                          unsigned int len,
 797                                          unsigned int *xdp_xmit,
 798                                          struct virtnet_rq_stats *stats)
 799 {
 800         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 801         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 802         struct page *page = virt_to_head_page(buf);
 803         int offset = buf - page_address(page);
 804         struct sk_buff *head_skb, *curr_skb;
 805         struct bpf_prog *xdp_prog;
 806         unsigned int truesize = mergeable_ctx_to_truesize(ctx);
 807         unsigned int headroom = mergeable_ctx_to_headroom(ctx);
 808         unsigned int metasize = 0;
 809         unsigned int frame_sz;
 810         int err;
 811
 812         head_skb = NULL;
 813         stats->bytes += len - vi->hdr_len;
 814
 815         rcu_read_lock();
 816         xdp_prog = rcu_dereference(rq->xdp_prog);
 817         if (xdp_prog) {
 818                 struct xdp_frame *xdpf;
 819                 struct page *xdp_page;
 820                 struct xdp_buff xdp;
 821                 void *data;
 822                 u32 act;
 823
 824                 /* Transient failure which in theory could occur if
 825                  * in-flight packets from before XDP was enabled reach
 826                  * the receive path after XDP is loaded.
 827                  */
 828                 if (unlikely(hdr->hdr.gso_type))
 829                         goto err_xdp;
 830
 831                 /* Buffers with headroom use PAGE_SIZE as alloc size,
 832                  * see add_recvbuf_mergeable() + get_mergeable_buf_len()
 833                  */
 834                 frame_sz = headroom ? PAGE_SIZE : truesize;
 835
 836                 /* This happens when rx buffer size is underestimated
 837                  * or headroom is not enough because of the buffer
 838                  * was refilled before XDP is set. This should only
 839                  * happen for the first several packets, so we don't
 840                  * care much about its performance.
 841                  */
 842                 if (unlikely(num_buf > 1 ||
 843                              headroom < virtnet_get_headroom(vi))) {
 844                         /* linearize data for XDP */
 845                         xdp_page = xdp_linearize_page(rq, &num_buf,
 846                                                       page, offset,
 847                                                       VIRTIO_XDP_HEADROOM,
 848                                                       &len);
 849                         frame_sz = PAGE_SIZE;
 850
 851                         if (!xdp_page)
 852                                 goto err_xdp;
 853                         offset = VIRTIO_XDP_HEADROOM;
 854                 } else {
 855                         xdp_page = page;
 856                 }
 857
 858                 /* Allow consuming headroom but reserve enough space to push
 859                  * the descriptor on if we get an XDP_TX return code.
 860                  */
 861                 data = page_address(xdp_page) + offset;
 862                 xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
 863                 xdp.data = data + vi->hdr_len;
 864                 xdp.data_end = xdp.data + (len - vi->hdr_len);
 865                 xdp.data_meta = xdp.data;
 866                 xdp.rxq = &rq->xdp_rxq;
 867                 xdp.frame_sz = frame_sz - vi->hdr_len;
 868
 869                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 870                 stats->xdp_packets++;
 871
 872                 switch (act) {
 873                 case XDP_PASS:
 874                         metasize = xdp.data - xdp.data_meta;
 875
 876                         /* recalculate offset to account for any header
 877                          * adjustments and minus the metasize to copy the
 878                          * metadata in page_to_skb(). Note other cases do not
 879                          * build an skb and avoid using offset
 880                          */
 881                         offset = xdp.data - page_address(xdp_page) -
 882                                  vi->hdr_len - metasize;
 883
 884                         /* recalculate len if xdp.data, xdp.data_end or
 885                          * xdp.data_meta were adjusted
 886                          */
 887                         len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
 888                         /* We can only create skb based on xdp_page. */
 889                         if (unlikely(xdp_page != page)) {
 890                                 rcu_read_unlock();
 891                                 put_page(page);
 892                                 head_skb = page_to_skb(vi, rq, xdp_page, offset,
 893                                                        len, PAGE_SIZE, false,
 894                                                        metasize);
 895                                 return head_skb;
 896                         }
 897                         break;
 898                 case XDP_TX:
 899                         stats->xdp_tx++;
 900                         xdpf = xdp_convert_buff_to_frame(&xdp);
 901                         if (unlikely(!xdpf))
 902                                 goto err_xdp;
 903                         err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 904                         if (unlikely(err < 0)) {
 905                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 906                                 if (unlikely(xdp_page != page))
 907                                         put_page(xdp_page);
 908                                 goto err_xdp;
 909                         }
 910                         *xdp_xmit |= VIRTIO_XDP_TX;
 911                         if (unlikely(xdp_page != page))
 912                                 put_page(page);
 913                         rcu_read_unlock();
 914                         goto xdp_xmit;
 915                 case XDP_REDIRECT:
 916                         stats->xdp_redirects++;
 917                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
 918                         if (err) {
 919                                 if (unlikely(xdp_page != page))
 920                                         put_page(xdp_page);
 921                                 goto err_xdp;
 922                         }
 923                         *xdp_xmit |= VIRTIO_XDP_REDIR;
 924                         if (unlikely(xdp_page != page))
 925                                 put_page(page);
 926                         rcu_read_unlock();
 927                         goto xdp_xmit;
 928                 default:
 929                         bpf_warn_invalid_xdp_action(act);
 930                         fallthrough;
 931                 case XDP_ABORTED:
 932                         trace_xdp_exception(vi->dev, xdp_prog, act);
 933                         fallthrough;
 934                 case XDP_DROP:
 935                         if (unlikely(xdp_page != page))
 936                                 __free_pages(xdp_page, 0);
 937                         goto err_xdp;
 938                 }
 939         }
 940         rcu_read_unlock();
 941
 942         if (unlikely(len > truesize)) {
 943                 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 944                          dev->name, len, (unsigned long)ctx);
 945                 dev->stats.rx_length_errors++;
 946                 goto err_skb;
 947         }
 948
 949         head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
 950                                metasize);
 951         curr_skb = head_skb;
 952
 953         if (unlikely(!curr_skb))
 954                 goto err_skb;
 955         while (--num_buf) {
 956                 int num_skb_frags;
 957
 958                 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
 959                 if (unlikely(!buf)) {
 960                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 961                                  dev->name, num_buf,
 962                                  virtio16_to_cpu(vi->vdev,
 963                                                  hdr->num_buffers));
 964                         dev->stats.rx_length_errors++;
 965                         goto err_buf;
 966                 }
 967
 968                 stats->bytes += len;
 969                 page = virt_to_head_page(buf);
 970
 971                 truesize = mergeable_ctx_to_truesize(ctx);
 972                 if (unlikely(len > truesize)) {
 973                         pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 974                                  dev->name, len, (unsigned long)ctx);
 975                         dev->stats.rx_length_errors++;
 976                         goto err_skb;
 977                 }
 978
 979                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 980                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 981                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 982
 983                         if (unlikely(!nskb))
 984                                 goto err_skb;
 985                         if (curr_skb == head_skb)
 986                                 skb_shinfo(curr_skb)->frag_list = nskb;
 987                         else
 988                                 curr_skb->next = nskb;
 989                         curr_skb = nskb;
 990                         head_skb->truesize += nskb->truesize;
 991                         num_skb_frags = 0;
 992                 }
 993                 if (curr_skb != head_skb) {
 994                         head_skb->data_len += len;
 995                         head_skb->len += len;
 996                         head_skb->truesize += truesize;
 997                 }
 998                 offset = buf - page_address(page);
 999                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
1000                         put_page(page);
1001                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
1002                                              len, truesize);
1003                 } else {
1004                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
1005                                         offset, len, truesize);
1006                 }
1007         }
1008
1009         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
1010         return head_skb;
1011
1012 err_xdp:
1013         rcu_read_unlock();
1014         stats->xdp_drops++;
1015 err_skb:
1016         put_page(page);
1017         while (num_buf-- > 1) {
1018                 buf = virtqueue_get_buf(rq->vq, &len);
1019                 if (unlikely(!buf)) {
1020                         pr_debug("%s: rx error: %d buffers missing\n",
1021                                  dev->name, num_buf);
1022                         dev->stats.rx_length_errors++;
1023                         break;
1024                 }
1025                 stats->bytes += len;
1026                 page = virt_to_head_page(buf);
1027                 put_page(page);
1028         }
1029 err_buf:
1030         stats->drops++;
1031         dev_kfree_skb(head_skb);
1032 xdp_xmit:
1033         return NULL;
1034 }
1035
1036 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1037                         void *buf, unsigned int len, void **ctx,
1038                         unsigned int *xdp_xmit,
1039                         struct virtnet_rq_stats *stats)
1040 {
1041         struct net_device *dev = vi->dev;
1042         struct sk_buff *skb;
1043         struct virtio_net_hdr_mrg_rxbuf *hdr;
1044
1045         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1046                 pr_debug("%s: short packet %i\n", dev->name, len);
1047                 dev->stats.rx_length_errors++;
1048                 if (vi->mergeable_rx_bufs) {
1049                         put_page(virt_to_head_page(buf));
1050                 } else if (vi->big_packets) {
1051                         give_pages(rq, buf);
1052                 } else {
1053                         put_page(virt_to_head_page(buf));
1054                 }
1055                 return;
1056         }
1057
1058         if (vi->mergeable_rx_bufs)
1059                 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1060                                         stats);
1061         else if (vi->big_packets)
1062                 skb = receive_big(dev, vi, rq, buf, len, stats);
1063         else
1064                 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1065
1066         if (unlikely(!skb))
1067                 return;
1068
1069         hdr = skb_vnet_hdr(skb);
1070
1071         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1072                 skb->ip_summed = CHECKSUM_UNNECESSARY;
1073
1074         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1075                                   virtio_is_little_endian(vi->vdev))) {
1076                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1077                                      dev->name, hdr->hdr.gso_type,
1078                                      hdr->hdr.gso_size);
1079                 goto frame_err;
1080         }
1081
1082         skb_record_rx_queue(skb, vq2rxq(rq->vq));
1083         skb->protocol = eth_type_trans(skb, dev);
1084         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1085                  ntohs(skb->protocol), skb->len, skb->pkt_type);
1086
1087         napi_gro_receive(&rq->napi, skb);
1088         return;
1089
1090 frame_err:
1091         dev->stats.rx_frame_errors++;
1092         dev_kfree_skb(skb);
1093 }
1094
1095 /* Unlike mergeable buffers, all buffers are allocated to the
1096  * same size, except for the headroom. For this reason we do
1097  * not need to use  mergeable_len_to_ctx here - it is enough
1098  * to store the headroom as the context ignoring the truesize.
1099  */
1100 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1101                              gfp_t gfp)
1102 {
1103         struct page_frag *alloc_frag = &rq->alloc_frag;
1104         char *buf;
1105         unsigned int xdp_headroom = virtnet_get_headroom(vi);
1106         void *ctx = (void *)(unsigned long)xdp_headroom;
1107         int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1108         int err;
1109
1110         len = SKB_DATA_ALIGN(len) +
1111               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1112         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1113                 return -ENOMEM;
1114
1115         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1116         get_page(alloc_frag->page);
1117         alloc_frag->offset += len;
1118         sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1119                     vi->hdr_len + GOOD_PACKET_LEN);
1120         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1121         if (err < 0)
1122                 put_page(virt_to_head_page(buf));
1123         return err;
1124 }
1125
1126 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1127                            gfp_t gfp)
1128 {
1129         struct page *first, *list = NULL;
1130         char *p;
1131         int i, err, offset;
1132
1133         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
1134
1135         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
1136         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
1137                 first = get_a_page(rq, gfp);
1138                 if (!first) {
1139                         if (list)
1140                                 give_pages(rq, list);
1141                         return -ENOMEM;
1142                 }
1143                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1144
1145                 /* chain new page in list head to match sg */
1146                 first->private = (unsigned long)list;
1147                 list = first;
1148         }
1149
1150         first = get_a_page(rq, gfp);
1151         if (!first) {
1152                 give_pages(rq, list);
1153                 return -ENOMEM;
1154         }
1155         p = page_address(first);
1156
1157         /* rq->sg[0], rq->sg[1] share the same page */
1158         /* a separated rq->sg[0] for header - required in case !any_header_sg */
1159         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1160
1161         /* rq->sg[1] for data packet, from offset */
1162         offset = sizeof(struct padded_vnet_hdr);
1163         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1164
1165         /* chain first in list head */
1166         first->private = (unsigned long)list;
1167         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
1168                                   first, gfp);
1169         if (err < 0)
1170                 give_pages(rq, first);
1171
1172         return err;
1173 }
1174
1175 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1176                                           struct ewma_pkt_len *avg_pkt_len,
1177                                           unsigned int room)
1178 {
1179         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1180         unsigned int len;
1181
1182         if (room)
1183                 return PAGE_SIZE - room;
1184
1185         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1186                                 rq->min_buf_len, PAGE_SIZE - hdr_len);
1187
1188         return ALIGN(len, L1_CACHE_BYTES);
1189 }
1190
1191 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1192                                  struct receive_queue *rq, gfp_t gfp)
1193 {
1194         struct page_frag *alloc_frag = &rq->alloc_frag;
1195         unsigned int headroom = virtnet_get_headroom(vi);
1196         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1197         unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1198         char *buf;
1199         void *ctx;
1200         int err;
1201         unsigned int len, hole;
1202
1203         /* Extra tailroom is needed to satisfy XDP's assumption. This
1204          * means rx frags coalescing won't work, but consider we've
1205          * disabled GSO for XDP, it won't be a big issue.
1206          */
1207         len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1208         if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1209                 return -ENOMEM;
1210
1211         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1212         buf += headroom; /* advance address leaving hole at front of pkt */
1213         get_page(alloc_frag->page);
1214         alloc_frag->offset += len + room;
1215         hole = alloc_frag->size - alloc_frag->offset;
1216         if (hole < len + room) {
1217                 /* To avoid internal fragmentation, if there is very likely not
1218                  * enough space for another buffer, add the remaining space to
1219                  * the current buffer.
1220                  */
1221                 len += hole;
1222                 alloc_frag->offset += hole;
1223         }
1224
1225         sg_init_one(rq->sg, buf, len);
1226         ctx = mergeable_len_to_ctx(len, headroom);
1227         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1228         if (err < 0)
1229                 put_page(virt_to_head_page(buf));
1230
1231         return err;
1232 }
1233
1234 /*
1235  * Returns false if we couldn't fill entirely (OOM).
1236  *
1237  * Normally run in the receive path, but can also be run from ndo_open
1238  * before we're receiving packets, or from refill_work which is
1239  * careful to disable receiving (using napi_disable).
1240  */
1241 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1242                           gfp_t gfp)
1243 {
1244         int err;
1245         bool oom;
1246
1247         do {
1248                 if (vi->mergeable_rx_bufs)
1249                         err = add_recvbuf_mergeable(vi, rq, gfp);
1250                 else if (vi->big_packets)
1251                         err = add_recvbuf_big(vi, rq, gfp);
1252                 else
1253                         err = add_recvbuf_small(vi, rq, gfp);
1254
1255                 oom = err == -ENOMEM;
1256                 if (err)
1257                         break;
1258         } while (rq->vq->num_free);
1259         if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1260                 unsigned long flags;
1261
1262                 flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
1263                 rq->stats.kicks++;
1264                 u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
1265         }
1266
1267         return !oom;
1268 }
1269
1270 static void skb_recv_done(struct virtqueue *rvq)
1271 {
1272         struct virtnet_info *vi = rvq->vdev->priv;
1273         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1274
1275         virtqueue_napi_schedule(&rq->napi, rvq);
1276 }
1277
1278 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1279 {
1280         napi_enable(napi);
1281
1282         /* If all buffers were filled by other side before we napi_enabled, we
1283          * won't get another interrupt, so process any outstanding packets now.
1284          * Call local_bh_enable after to trigger softIRQ processing.
1285          */
1286         local_bh_disable();
1287         virtqueue_napi_schedule(napi, vq);
1288         local_bh_enable();
1289 }
1290
1291 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1292                                    struct virtqueue *vq,
1293                                    struct napi_struct *napi)
1294 {
1295         if (!napi->weight)
1296                 return;
1297
1298         /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1299          * enable the feature if this is likely affine with the transmit path.
1300          */
1301         if (!vi->affinity_hint_set) {
1302                 napi->weight = 0;
1303                 return;
1304         }
1305
1306         return virtnet_napi_enable(vq, napi);
1307 }
1308
1309 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1310 {
1311         if (napi->weight)
1312                 napi_disable(napi);
1313 }
1314
1315 static void refill_work(struct work_struct *work)
1316 {
1317         struct virtnet_info *vi =
1318                 container_of(work, struct virtnet_info, refill.work);
1319         bool still_empty;
1320         int i;
1321
1322         for (i = 0; i < vi->curr_queue_pairs; i++) {
1323                 struct receive_queue *rq = &vi->rq[i];
1324
1325                 napi_disable(&rq->napi);
1326                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1327                 virtnet_napi_enable(rq->vq, &rq->napi);
1328
1329                 /* In theory, this can happen: if we don't get any buffers in
1330                  * we will *never* try to fill again.
1331                  */
1332                 if (still_empty)
1333                         schedule_delayed_work(&vi->refill, HZ/2);
1334         }
1335 }
1336
1337 static int virtnet_receive(struct receive_queue *rq, int budget,
1338                            unsigned int *xdp_xmit)
1339 {
1340         struct virtnet_info *vi = rq->vq->vdev->priv;
1341         struct virtnet_rq_stats stats = {};
1342         unsigned int len;
1343         void *buf;
1344         int i;
1345
1346         if (!vi->big_packets || vi->mergeable_rx_bufs) {
1347                 void *ctx;
1348
1349                 while (stats.packets < budget &&
1350                        (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1351                         receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1352                         stats.packets++;
1353                 }
1354         } else {
1355                 while (stats.packets < budget &&
1356                        (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1357                         receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1358                         stats.packets++;
1359                 }
1360         }
1361
1362         if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1363                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1364                         schedule_delayed_work(&vi->refill, 0);
1365         }
1366
1367         u64_stats_update_begin(&rq->stats.syncp);
1368         for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1369                 size_t offset = virtnet_rq_stats_desc[i].offset;
1370                 u64 *item;
1371
1372                 item = (u64 *)((u8 *)&rq->stats + offset);
1373                 *item += *(u64 *)((u8 *)&stats + offset);
1374         }
1375         u64_stats_update_end(&rq->stats.syncp);
1376
1377         return stats.packets;
1378 }
1379
1380 static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
1381 {
1382         unsigned int len;
1383         unsigned int packets = 0;
1384         unsigned int bytes = 0;
1385         void *ptr;
1386
1387         while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1388                 if (likely(!is_xdp_frame(ptr))) {
1389                         struct sk_buff *skb = ptr;
1390
1391                         pr_debug("Sent skb %p\n", skb);
1392
1393                         bytes += skb->len;
1394                         napi_consume_skb(skb, in_napi);
1395                 } else {
1396                         struct xdp_frame *frame = ptr_to_xdp(ptr);
1397
1398                         bytes += frame->len;
1399                         xdp_return_frame(frame);
1400                 }
1401                 packets++;
1402         }
1403
1404         /* Avoid overhead when no packets have been processed
1405          * happens when called speculatively from start_xmit.
1406          */
1407         if (!packets)
1408                 return;
1409
1410         u64_stats_update_begin(&sq->stats.syncp);
1411         sq->stats.bytes += bytes;
1412         sq->stats.packets += packets;
1413         u64_stats_update_end(&sq->stats.syncp);
1414 }
1415
1416 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
1417 {
1418         if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
1419                 return false;
1420         else if (q < vi->curr_queue_pairs)
1421                 return true;
1422         else
1423                 return false;
1424 }
1425
1426 static void virtnet_poll_cleantx(struct receive_queue *rq)
1427 {
1428         struct virtnet_info *vi = rq->vq->vdev->priv;
1429         unsigned int index = vq2rxq(rq->vq);
1430         struct send_queue *sq = &vi->sq[index];
1431         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1432
1433         if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1434                 return;
1435
1436         if (__netif_tx_trylock(txq)) {
1437                 free_old_xmit_skbs(sq, true);
1438                 __netif_tx_unlock(txq);
1439         }
1440
1441         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1442                 netif_tx_wake_queue(txq);
1443 }
1444
1445 static int virtnet_poll(struct napi_struct *napi, int budget)
1446 {
1447         struct receive_queue *rq =
1448                 container_of(napi, struct receive_queue, napi);
1449         struct virtnet_info *vi = rq->vq->vdev->priv;
1450         struct send_queue *sq;
1451         unsigned int received;
1452         unsigned int xdp_xmit = 0;
1453
1454         virtnet_poll_cleantx(rq);
1455
1456         received = virtnet_receive(rq, budget, &xdp_xmit);
1457
1458         /* Out of packets? */
1459         if (received < budget)
1460                 virtqueue_napi_complete(napi, rq->vq, received);
1461
1462         if (xdp_xmit & VIRTIO_XDP_REDIR)
1463                 xdp_do_flush();
1464
1465         if (xdp_xmit & VIRTIO_XDP_TX) {
1466                 sq = virtnet_xdp_sq(vi);
1467                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1468                         u64_stats_update_begin(&sq->stats.syncp);
1469                         sq->stats.kicks++;
1470                         u64_stats_update_end(&sq->stats.syncp);
1471                 }
1472         }
1473
1474         return received;
1475 }
1476
1477 static int virtnet_open(struct net_device *dev)
1478 {
1479         struct virtnet_info *vi = netdev_priv(dev);
1480         int i, err;
1481
1482         for (i = 0; i < vi->max_queue_pairs; i++) {
1483                 if (i < vi->curr_queue_pairs)
1484                         /* Make sure we have some buffers: if oom use wq. */
1485                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1486                                 schedule_delayed_work(&vi->refill, 0);
1487
1488                 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
1489                 if (err < 0)
1490                         return err;
1491
1492                 err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1493                                                  MEM_TYPE_PAGE_SHARED, NULL);
1494                 if (err < 0) {
1495                         xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1496                         return err;
1497                 }
1498
1499                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1500                 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1501         }
1502
1503         return 0;
1504 }
1505
1506 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1507 {
1508         struct send_queue *sq = container_of(napi, struct send_queue, napi);
1509         struct virtnet_info *vi = sq->vq->vdev->priv;
1510         unsigned int index = vq2txq(sq->vq);
1511         struct netdev_queue *txq;
1512
1513         if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1514                 /* We don't need to enable cb for XDP */
1515                 napi_complete_done(napi, 0);
1516                 return 0;
1517         }
1518
1519         txq = netdev_get_tx_queue(vi->dev, index);
1520         __netif_tx_lock(txq, raw_smp_processor_id());
1521         free_old_xmit_skbs(sq, true);
1522         __netif_tx_unlock(txq);
1523
1524         virtqueue_napi_complete(napi, sq->vq, 0);
1525
1526         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1527                 netif_tx_wake_queue(txq);
1528
1529         return 0;
1530 }
1531
1532 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1533 {
1534         struct virtio_net_hdr_mrg_rxbuf *hdr;
1535         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1536         struct virtnet_info *vi = sq->vq->vdev->priv;
1537         int num_sg;
1538         unsigned hdr_len = vi->hdr_len;
1539         bool can_push;
1540
1541         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1542
1543         can_push = vi->any_header_sg &&
1544                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1545                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1546         /* Even if we can, don't push here yet as this would skew
1547          * csum_start offset below. */
1548         if (can_push)
1549                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1550         else
1551                 hdr = skb_vnet_hdr(skb);
1552
1553         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1554                                     virtio_is_little_endian(vi->vdev), false,
1555                                     0))
1556                 BUG();
1557
1558         if (vi->mergeable_rx_bufs)
1559                 hdr->num_buffers = 0;
1560
1561         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1562         if (can_push) {
1563                 __skb_push(skb, hdr_len);
1564                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1565                 if (unlikely(num_sg < 0))
1566                         return num_sg;
1567                 /* Pull header back to avoid skew in tx bytes calculations. */
1568                 __skb_pull(skb, hdr_len);
1569         } else {
1570                 sg_set_buf(sq->sg, hdr, hdr_len);
1571                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1572                 if (unlikely(num_sg < 0))
1573                         return num_sg;
1574                 num_sg++;
1575         }
1576         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1577 }
1578
1579 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1580 {
1581         struct virtnet_info *vi = netdev_priv(dev);
1582         int qnum = skb_get_queue_mapping(skb);
1583         struct send_queue *sq = &vi->sq[qnum];
1584         int err;
1585         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1586         bool kick = !netdev_xmit_more();
1587         bool use_napi = sq->napi.weight;
1588
1589         /* Free up any pending old buffers before queueing new ones. */
1590         free_old_xmit_skbs(sq, false);
1591
1592         if (use_napi && kick)
1593                 virtqueue_enable_cb_delayed(sq->vq);
1594
1595         /* timestamp packet in software */
1596         skb_tx_timestamp(skb);
1597
1598         /* Try to transmit */
1599         err = xmit_skb(sq, skb);
1600
1601         /* This should not happen! */
1602         if (unlikely(err)) {
1603                 dev->stats.tx_fifo_errors++;
1604                 if (net_ratelimit())
1605                         dev_warn(&dev->dev,
1606                                  "Unexpected TXQ (%d) queue failure: %d\n",
1607                                  qnum, err);
1608                 dev->stats.tx_dropped++;
1609                 dev_kfree_skb_any(skb);
1610                 return NETDEV_TX_OK;
1611         }
1612
1613         /* Don't wait up for transmitted skbs to be freed. */
1614         if (!use_napi) {
1615                 skb_orphan(skb);
1616                 nf_reset_ct(skb);
1617         }
1618
1619         /* If running out of space, stop queue to avoid getting packets that we
1620          * are then unable to transmit.
1621          * An alternative would be to force queuing layer to requeue the skb by
1622          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1623          * returned in a normal path of operation: it means that driver is not
1624          * maintaining the TX queue stop/start state properly, and causes
1625          * the stack to do a non-trivial amount of useless work.
1626          * Since most packets only take 1 or 2 ring slots, stopping the queue
1627          * early means 16 slots are typically wasted.
1628          */
1629         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1630                 netif_stop_subqueue(dev, qnum);
1631                 if (!use_napi &&
1632                     unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1633                         /* More just got used, free them then recheck. */
1634                         free_old_xmit_skbs(sq, false);
1635                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1636                                 netif_start_subqueue(dev, qnum);
1637                                 virtqueue_disable_cb(sq->vq);
1638                         }
1639                 }
1640         }
1641
1642         if (kick || netif_xmit_stopped(txq)) {
1643                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1644                         u64_stats_update_begin(&sq->stats.syncp);
1645                         sq->stats.kicks++;
1646                         u64_stats_update_end(&sq->stats.syncp);
1647                 }
1648         }
1649
1650         return NETDEV_TX_OK;
1651 }
1652
1653 /*
1654  * Send command via the control virtqueue and check status.  Commands
1655  * supported by the hypervisor, as indicated by feature bits, should
1656  * never fail unless improperly formatted.
1657  */
1658 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1659                                  struct scatterlist *out)
1660 {
1661         struct scatterlist *sgs[4], hdr, stat;
1662         unsigned out_num = 0, tmp;
1663
1664         /* Caller should know better */
1665         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1666
1667         vi->ctrl->status = ~0;
1668         vi->ctrl->hdr.class = class;
1669         vi->ctrl->hdr.cmd = cmd;
1670         /* Add header */
1671         sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1672         sgs[out_num++] = &hdr;
1673
1674         if (out)
1675                 sgs[out_num++] = out;
1676
1677         /* Add return status. */
1678         sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1679         sgs[out_num] = &stat;
1680
1681         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1682         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1683
1684         if (unlikely(!virtqueue_kick(vi->cvq)))
1685                 return vi->ctrl->status == VIRTIO_NET_OK;
1686
1687         /* Spin for a response, the kick causes an ioport write, trapping
1688          * into the hypervisor, so the request should be handled immediately.
1689          */
1690         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1691                !virtqueue_is_broken(vi->cvq))
1692                 cpu_relax();
1693
1694         return vi->ctrl->status == VIRTIO_NET_OK;
1695 }
1696
1697 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1698 {
1699         struct virtnet_info *vi = netdev_priv(dev);
1700         struct virtio_device *vdev = vi->vdev;
1701         int ret;
1702         struct sockaddr *addr;
1703         struct scatterlist sg;
1704
1705         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
1706                 return -EOPNOTSUPP;
1707
1708         addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1709         if (!addr)
1710                 return -ENOMEM;
1711
1712         ret = eth_prepare_mac_addr_change(dev, addr);
1713         if (ret)
1714                 goto out;
1715
1716         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1717                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1718                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1719                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1720                         dev_warn(&vdev->dev,
1721                                  "Failed to set mac address by vq command.\n");
1722                         ret = -EINVAL;
1723                         goto out;
1724                 }
1725         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1726                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1727                 unsigned int i;
1728
1729                 /* Naturally, this has an atomicity problem. */
1730                 for (i = 0; i < dev->addr_len; i++)
1731                         virtio_cwrite8(vdev,
1732                                        offsetof(struct virtio_net_config, mac) +
1733                                        i, addr->sa_data[i]);
1734         }
1735
1736         eth_commit_mac_addr_change(dev, p);
1737         ret = 0;
1738
1739 out:
1740         kfree(addr);
1741         return ret;
1742 }
1743
1744 static void virtnet_stats(struct net_device *dev,
1745                           struct rtnl_link_stats64 *tot)
1746 {
1747         struct virtnet_info *vi = netdev_priv(dev);
1748         unsigned int start;
1749         int i;
1750
1751         for (i = 0; i < vi->max_queue_pairs; i++) {
1752                 u64 tpackets, tbytes, rpackets, rbytes, rdrops;
1753                 struct receive_queue *rq = &vi->rq[i];
1754                 struct send_queue *sq = &vi->sq[i];
1755
1756                 do {
1757                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1758                         tpackets = sq->stats.packets;
1759                         tbytes   = sq->stats.bytes;
1760                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1761
1762                 do {
1763                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1764                         rpackets = rq->stats.packets;
1765                         rbytes   = rq->stats.bytes;
1766                         rdrops   = rq->stats.drops;
1767                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1768
1769                 tot->rx_packets += rpackets;
1770                 tot->tx_packets += tpackets;
1771                 tot->rx_bytes   += rbytes;
1772                 tot->tx_bytes   += tbytes;
1773                 tot->rx_dropped += rdrops;
1774         }
1775
1776         tot->tx_dropped = dev->stats.tx_dropped;
1777         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1778         tot->rx_length_errors = dev->stats.rx_length_errors;
1779         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1780 }
1781
1782 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1783 {
1784         rtnl_lock();
1785         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1786                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1787                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1788         rtnl_unlock();
1789 }
1790
1791 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1792 {
1793         struct scatterlist sg;
1794         struct net_device *dev = vi->dev;
1795
1796         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1797                 return 0;
1798
1799         vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1800         sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
1801
1802         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1803                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1804                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1805                          queue_pairs);
1806                 return -EINVAL;
1807         } else {
1808                 vi->curr_queue_pairs = queue_pairs;
1809                 /* virtnet_open() will refill when device is going to up. */
1810                 if (dev->flags & IFF_UP)
1811                         schedule_delayed_work(&vi->refill, 0);
1812         }
1813
1814         return 0;
1815 }
1816
1817 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1818 {
1819         int err;
1820
1821         rtnl_lock();
1822         err = _virtnet_set_queues(vi, queue_pairs);
1823         rtnl_unlock();
1824         return err;
1825 }
1826
1827 static int virtnet_close(struct net_device *dev)
1828 {
1829         struct virtnet_info *vi = netdev_priv(dev);
1830         int i;
1831
1832         /* Make sure refill_work doesn't re-enable napi! */
1833         cancel_delayed_work_sync(&vi->refill);
1834
1835         for (i = 0; i < vi->max_queue_pairs; i++) {
1836                 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1837                 napi_disable(&vi->rq[i].napi);
1838                 virtnet_napi_tx_disable(&vi->sq[i].napi);
1839         }
1840
1841         return 0;
1842 }
1843
1844 static void virtnet_set_rx_mode(struct net_device *dev)
1845 {
1846         struct virtnet_info *vi = netdev_priv(dev);
1847         struct scatterlist sg[2];
1848         struct virtio_net_ctrl_mac *mac_data;
1849         struct netdev_hw_addr *ha;
1850         int uc_count;
1851         int mc_count;
1852         void *buf;
1853         int i;
1854
1855         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1856         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1857                 return;
1858
1859         vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
1860         vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1861
1862         sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
1863
1864         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1865                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1866                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1867                          vi->ctrl->promisc ? "en" : "dis");
1868
1869         sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
1870
1871         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1872                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1873                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1874                          vi->ctrl->allmulti ? "en" : "dis");
1875
1876         uc_count = netdev_uc_count(dev);
1877         mc_count = netdev_mc_count(dev);
1878         /* MAC filter - use one buffer for both lists */
1879         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1880                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1881         mac_data = buf;
1882         if (!buf)
1883                 return;
1884
1885         sg_init_table(sg, 2);
1886
1887         /* Store the unicast list and count in the front of the buffer */
1888         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1889         i = 0;
1890         netdev_for_each_uc_addr(ha, dev)
1891                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1892
1893         sg_set_buf(&sg[0], mac_data,
1894                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1895
1896         /* multicast list and count fill the end */
1897         mac_data = (void *)&mac_data->macs[uc_count][0];
1898
1899         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1900         i = 0;
1901         netdev_for_each_mc_addr(ha, dev)
1902                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1903
1904         sg_set_buf(&sg[1], mac_data,
1905                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1906
1907         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1908                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1909                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1910
1911         kfree(buf);
1912 }
1913
1914 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1915                                    __be16 proto, u16 vid)
1916 {
1917         struct virtnet_info *vi = netdev_priv(dev);
1918         struct scatterlist sg;
1919
1920         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1921         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1922
1923         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1924                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1925                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1926         return 0;
1927 }
1928
1929 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1930                                     __be16 proto, u16 vid)
1931 {
1932         struct virtnet_info *vi = netdev_priv(dev);
1933         struct scatterlist sg;
1934
1935         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1936         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1937
1938         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1939                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1940                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1941         return 0;
1942 }
1943
1944 static void virtnet_clean_affinity(struct virtnet_info *vi)
1945 {
1946         int i;
1947
1948         if (vi->affinity_hint_set) {
1949                 for (i = 0; i < vi->max_queue_pairs; i++) {
1950                         virtqueue_set_affinity(vi->rq[i].vq, NULL);
1951                         virtqueue_set_affinity(vi->sq[i].vq, NULL);
1952                 }
1953
1954                 vi->affinity_hint_set = false;
1955         }
1956 }
1957
1958 static void virtnet_set_affinity(struct virtnet_info *vi)
1959 {
1960         cpumask_var_t mask;
1961         int stragglers;
1962         int group_size;
1963         int i, j, cpu;
1964         int num_cpu;
1965         int stride;
1966
1967         if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
1968                 virtnet_clean_affinity(vi);
1969                 return;
1970         }
1971
1972         num_cpu = num_online_cpus();
1973         stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
1974         stragglers = num_cpu >= vi->curr_queue_pairs ?
1975                         num_cpu % vi->curr_queue_pairs :
1976                         0;
1977         cpu = cpumask_next(-1, cpu_online_mask);
1978
1979         for (i = 0; i < vi->curr_queue_pairs; i++) {
1980                 group_size = stride + (i < stragglers ? 1 : 0);
1981
1982                 for (j = 0; j < group_size; j++) {
1983                         cpumask_set_cpu(cpu, mask);
1984                         cpu = cpumask_next_wrap(cpu, cpu_online_mask,
1985                                                 nr_cpu_ids, false);
1986                 }
1987                 virtqueue_set_affinity(vi->rq[i].vq, mask);
1988                 virtqueue_set_affinity(vi->sq[i].vq, mask);
1989                 __netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, false);
1990                 cpumask_clear(mask);
1991         }
1992
1993         vi->affinity_hint_set = true;
1994         free_cpumask_var(mask);
1995 }
1996
1997 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1998 {
1999         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2000                                                    node);
2001         virtnet_set_affinity(vi);
2002         return 0;
2003 }
2004
2005 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
2006 {
2007         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2008                                                    node_dead);
2009         virtnet_set_affinity(vi);
2010         return 0;
2011 }
2012
2013 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
2014 {
2015         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2016                                                    node);
2017
2018         virtnet_clean_affinity(vi);
2019         return 0;
2020 }
2021
2022 static enum cpuhp_state virtionet_online;
2023
2024 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
2025 {
2026         int ret;
2027
2028         ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2029         if (ret)
2030                 return ret;
2031         ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2032                                                &vi->node_dead);
2033         if (!ret)
2034                 return ret;
2035         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2036         return ret;
2037 }
2038
2039 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2040 {
2041         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2042         cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2043                                             &vi->node_dead);
2044 }
2045
2046 static void virtnet_get_ringparam(struct net_device *dev,
2047                                 struct ethtool_ringparam *ring)
2048 {
2049         struct virtnet_info *vi = netdev_priv(dev);
2050
2051         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2052         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2053         ring->rx_pending = ring->rx_max_pending;
2054         ring->tx_pending = ring->tx_max_pending;
2055 }
2056
2057
2058 static void virtnet_get_drvinfo(struct net_device *dev,
2059                                 struct ethtool_drvinfo *info)
2060 {
2061         struct virtnet_info *vi = netdev_priv(dev);
2062         struct virtio_device *vdev = vi->vdev;
2063
2064         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2065         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2066         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2067
2068 }
2069
2070 /* TODO: Eliminate OOO packets during switching */
2071 static int virtnet_set_channels(struct net_device *dev,
2072                                 struct ethtool_channels *channels)
2073 {
2074         struct virtnet_info *vi = netdev_priv(dev);
2075         u16 queue_pairs = channels->combined_count;
2076         int err;
2077
2078         /* We don't support separate rx/tx channels.
2079          * We don't allow setting 'other' channels.
2080          */
2081         if (channels->rx_count || channels->tx_count || channels->other_count)
2082                 return -EINVAL;
2083
2084         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2085                 return -EINVAL;
2086
2087         /* For now we don't support modifying channels while XDP is loaded
2088          * also when XDP is loaded all RX queues have XDP programs so we only
2089          * need to check a single RX queue.
2090          */
2091         if (vi->rq[0].xdp_prog)
2092                 return -EINVAL;
2093
2094         get_online_cpus();
2095         err = _virtnet_set_queues(vi, queue_pairs);
2096         if (!err) {
2097                 netif_set_real_num_tx_queues(dev, queue_pairs);
2098                 netif_set_real_num_rx_queues(dev, queue_pairs);
2099
2100                 virtnet_set_affinity(vi);
2101         }
2102         put_online_cpus();
2103
2104         return err;
2105 }
2106
2107 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2108 {
2109         struct virtnet_info *vi = netdev_priv(dev);
2110         char *p = (char *)data;
2111         unsigned int i, j;
2112
2113         switch (stringset) {
2114         case ETH_SS_STATS:
2115                 for (i = 0; i < vi->curr_queue_pairs; i++) {
2116                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2117                                 snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
2118                                          i, virtnet_rq_stats_desc[j].desc);
2119                                 p += ETH_GSTRING_LEN;
2120                         }
2121                 }
2122
2123                 for (i = 0; i < vi->curr_queue_pairs; i++) {
2124                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2125                                 snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
2126                                          i, virtnet_sq_stats_desc[j].desc);
2127                                 p += ETH_GSTRING_LEN;
2128                         }
2129                 }
2130                 break;
2131         }
2132 }
2133
2134 static int virtnet_get_sset_count(struct net_device *dev, int sset)
2135 {
2136         struct virtnet_info *vi = netdev_priv(dev);
2137
2138         switch (sset) {
2139         case ETH_SS_STATS:
2140                 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2141                                                VIRTNET_SQ_STATS_LEN);
2142         default:
2143                 return -EOPNOTSUPP;
2144         }
2145 }
2146
2147 static void virtnet_get_ethtool_stats(struct net_device *dev,
2148                                       struct ethtool_stats *stats, u64 *data)
2149 {
2150         struct virtnet_info *vi = netdev_priv(dev);
2151         unsigned int idx = 0, start, i, j;
2152         const u8 *stats_base;
2153         size_t offset;
2154
2155         for (i = 0; i < vi->curr_queue_pairs; i++) {
2156                 struct receive_queue *rq = &vi->rq[i];
2157
2158                 stats_base = (u8 *)&rq->stats;
2159                 do {
2160                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
2161                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2162                                 offset = virtnet_rq_stats_desc[j].offset;
2163                                 data[idx + j] = *(u64 *)(stats_base + offset);
2164                         }
2165                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
2166                 idx += VIRTNET_RQ_STATS_LEN;
2167         }
2168
2169         for (i = 0; i < vi->curr_queue_pairs; i++) {
2170                 struct send_queue *sq = &vi->sq[i];
2171
2172                 stats_base = (u8 *)&sq->stats;
2173                 do {
2174                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
2175                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2176                                 offset = virtnet_sq_stats_desc[j].offset;
2177                                 data[idx + j] = *(u64 *)(stats_base + offset);
2178                         }
2179                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
2180                 idx += VIRTNET_SQ_STATS_LEN;
2181         }
2182 }
2183
2184 static void virtnet_get_channels(struct net_device *dev,
2185                                  struct ethtool_channels *channels)
2186 {
2187         struct virtnet_info *vi = netdev_priv(dev);
2188
2189         channels->combined_count = vi->curr_queue_pairs;
2190         channels->max_combined = vi->max_queue_pairs;
2191         channels->max_other = 0;
2192         channels->rx_count = 0;
2193         channels->tx_count = 0;
2194         channels->other_count = 0;
2195 }
2196
2197 static int virtnet_set_link_ksettings(struct net_device *dev,
2198                                       const struct ethtool_link_ksettings *cmd)
2199 {
2200         struct virtnet_info *vi = netdev_priv(dev);
2201
2202         return ethtool_virtdev_set_link_ksettings(dev, cmd,
2203                                                   &vi->speed, &vi->duplex);
2204 }
2205
2206 static int virtnet_get_link_ksettings(struct net_device *dev,
2207                                       struct ethtool_link_ksettings *cmd)
2208 {
2209         struct virtnet_info *vi = netdev_priv(dev);
2210
2211         cmd->base.speed = vi->speed;
2212         cmd->base.duplex = vi->duplex;
2213         cmd->base.port = PORT_OTHER;
2214
2215         return 0;
2216 }
2217
2218 static int virtnet_set_coalesce(struct net_device *dev,
2219                                 struct ethtool_coalesce *ec)
2220 {
2221         struct virtnet_info *vi = netdev_priv(dev);
2222         int i, napi_weight;
2223
2224         if (ec->tx_max_coalesced_frames > 1 ||
2225             ec->rx_max_coalesced_frames != 1)
2226                 return -EINVAL;
2227
2228         napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2229         if (napi_weight ^ vi->sq[0].napi.weight) {
2230                 if (dev->flags & IFF_UP)
2231                         return -EBUSY;
2232                 for (i = 0; i < vi->max_queue_pairs; i++)
2233                         vi->sq[i].napi.weight = napi_weight;
2234         }
2235
2236         return 0;
2237 }
2238
2239 static int virtnet_get_coalesce(struct net_device *dev,
2240                                 struct ethtool_coalesce *ec)
2241 {
2242         struct ethtool_coalesce ec_default = {
2243                 .cmd = ETHTOOL_GCOALESCE,
2244                 .rx_max_coalesced_frames = 1,
2245         };
2246         struct virtnet_info *vi = netdev_priv(dev);
2247
2248         memcpy(ec, &ec_default, sizeof(ec_default));
2249
2250         if (vi->sq[0].napi.weight)
2251                 ec->tx_max_coalesced_frames = 1;
2252
2253         return 0;
2254 }
2255
2256 static void virtnet_init_settings(struct net_device *dev)
2257 {
2258         struct virtnet_info *vi = netdev_priv(dev);
2259
2260         vi->speed = SPEED_UNKNOWN;
2261         vi->duplex = DUPLEX_UNKNOWN;
2262 }
2263
2264 static void virtnet_update_settings(struct virtnet_info *vi)
2265 {
2266         u32 speed;
2267         u8 duplex;
2268
2269         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2270                 return;
2271
2272         virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
2273
2274         if (ethtool_validate_speed(speed))
2275                 vi->speed = speed;
2276
2277         virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
2278
2279         if (ethtool_validate_duplex(duplex))
2280                 vi->duplex = duplex;
2281 }
2282
2283 static const struct ethtool_ops virtnet_ethtool_ops = {
2284         .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES,
2285         .get_drvinfo = virtnet_get_drvinfo,
2286         .get_link = ethtool_op_get_link,
2287         .get_ringparam = virtnet_get_ringparam,
2288         .get_strings = virtnet_get_strings,
2289         .get_sset_count = virtnet_get_sset_count,
2290         .get_ethtool_stats = virtnet_get_ethtool_stats,
2291         .set_channels = virtnet_set_channels,
2292         .get_channels = virtnet_get_channels,
2293         .get_ts_info = ethtool_op_get_ts_info,
2294         .get_link_ksettings = virtnet_get_link_ksettings,
2295         .set_link_ksettings = virtnet_set_link_ksettings,
2296         .set_coalesce = virtnet_set_coalesce,
2297         .get_coalesce = virtnet_get_coalesce,
2298 };
2299
2300 static void virtnet_freeze_down(struct virtio_device *vdev)
2301 {
2302         struct virtnet_info *vi = vdev->priv;
2303         int i;
2304
2305         /* Make sure no work handler is accessing the device */
2306         flush_work(&vi->config_work);
2307
2308         netif_tx_lock_bh(vi->dev);
2309         netif_device_detach(vi->dev);
2310         netif_tx_unlock_bh(vi->dev);
2311         cancel_delayed_work_sync(&vi->refill);
2312
2313         if (netif_running(vi->dev)) {
2314                 for (i = 0; i < vi->max_queue_pairs; i++) {
2315                         napi_disable(&vi->rq[i].napi);
2316                         virtnet_napi_tx_disable(&vi->sq[i].napi);
2317                 }
2318         }
2319 }
2320
2321 static int init_vqs(struct virtnet_info *vi);
2322
2323 static int virtnet_restore_up(struct virtio_device *vdev)
2324 {
2325         struct virtnet_info *vi = vdev->priv;
2326         int err, i;
2327
2328         err = init_vqs(vi);
2329         if (err)
2330                 return err;
2331
2332         virtio_device_ready(vdev);
2333
2334         if (netif_running(vi->dev)) {
2335                 for (i = 0; i < vi->curr_queue_pairs; i++)
2336                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2337                                 schedule_delayed_work(&vi->refill, 0);
2338
2339                 for (i = 0; i < vi->max_queue_pairs; i++) {
2340                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2341                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2342                                                &vi->sq[i].napi);
2343                 }
2344         }
2345
2346         netif_tx_lock_bh(vi->dev);
2347         netif_device_attach(vi->dev);
2348         netif_tx_unlock_bh(vi->dev);
2349         return err;
2350 }
2351
2352 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2353 {
2354         struct scatterlist sg;
2355         vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
2356
2357         sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
2358
2359         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2360                                   VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2361                 dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
2362                 return -EINVAL;
2363         }
2364
2365         return 0;
2366 }
2367
2368 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2369 {
2370         u64 offloads = 0;
2371
2372         if (!vi->guest_offloads)
2373                 return 0;
2374
2375         return virtnet_set_guest_offloads(vi, offloads);
2376 }
2377
2378 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2379 {
2380         u64 offloads = vi->guest_offloads;
2381
2382         if (!vi->guest_offloads)
2383                 return 0;
2384
2385         return virtnet_set_guest_offloads(vi, offloads);
2386 }
2387
2388 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2389                            struct netlink_ext_ack *extack)
2390 {
2391         unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2392         struct virtnet_info *vi = netdev_priv(dev);
2393         struct bpf_prog *old_prog;
2394         u16 xdp_qp = 0, curr_qp;
2395         int i, err;
2396
2397         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2398             && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2399                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2400                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2401                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
2402                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
2403                 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO/CSUM, disable LRO/CSUM first");
2404                 return -EOPNOTSUPP;
2405         }
2406
2407         if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2408                 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2409                 return -EINVAL;
2410         }
2411
2412         if (dev->mtu > max_sz) {
2413                 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2414                 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2415                 return -EINVAL;
2416         }
2417
2418         curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2419         if (prog)
2420                 xdp_qp = nr_cpu_ids;
2421
2422         /* XDP requires extra queues for XDP_TX */
2423         if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2424                 NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
2425                 netdev_warn(dev, "request %i queues but max is %i\n",
2426                             curr_qp + xdp_qp, vi->max_queue_pairs);
2427                 return -ENOMEM;
2428         }
2429
2430         old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
2431         if (!prog && !old_prog)
2432                 return 0;
2433
2434         if (prog)
2435                 bpf_prog_add(prog, vi->max_queue_pairs - 1);
2436
2437         /* Make sure NAPI is not using any XDP TX queues for RX. */
2438         if (netif_running(dev)) {
2439                 for (i = 0; i < vi->max_queue_pairs; i++) {
2440                         napi_disable(&vi->rq[i].napi);
2441                         virtnet_napi_tx_disable(&vi->sq[i].napi);
2442                 }
2443         }
2444
2445         if (!prog) {
2446                 for (i = 0; i < vi->max_queue_pairs; i++) {
2447                         rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2448                         if (i == 0)
2449                                 virtnet_restore_guest_offloads(vi);
2450                 }
2451                 synchronize_net();
2452         }
2453
2454         err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2455         if (err)
2456                 goto err;
2457         netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2458         vi->xdp_queue_pairs = xdp_qp;
2459
2460         if (prog) {
2461                 for (i = 0; i < vi->max_queue_pairs; i++) {
2462                         rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2463                         if (i == 0 && !old_prog)
2464                                 virtnet_clear_guest_offloads(vi);
2465                 }
2466         }
2467
2468         for (i = 0; i < vi->max_queue_pairs; i++) {
2469                 if (old_prog)
2470                         bpf_prog_put(old_prog);
2471                 if (netif_running(dev)) {
2472                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2473                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2474                                                &vi->sq[i].napi);
2475                 }
2476         }
2477
2478         return 0;
2479
2480 err:
2481         if (!prog) {
2482                 virtnet_clear_guest_offloads(vi);
2483                 for (i = 0; i < vi->max_queue_pairs; i++)
2484                         rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
2485         }
2486
2487         if (netif_running(dev)) {
2488                 for (i = 0; i < vi->max_queue_pairs; i++) {
2489                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2490                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2491                                                &vi->sq[i].napi);
2492                 }
2493         }
2494         if (prog)
2495                 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2496         return err;
2497 }
2498
2499 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2500 {
2501         switch (xdp->command) {
2502         case XDP_SETUP_PROG:
2503                 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2504         default:
2505                 return -EINVAL;
2506         }
2507 }
2508
2509 static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
2510                                       size_t len)
2511 {
2512         struct virtnet_info *vi = netdev_priv(dev);
2513         int ret;
2514
2515         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2516                 return -EOPNOTSUPP;
2517
2518         ret = snprintf(buf, len, "sby");
2519         if (ret >= len)
2520                 return -EOPNOTSUPP;
2521
2522         return 0;
2523 }
2524
2525 static int virtnet_set_features(struct net_device *dev,
2526                                 netdev_features_t features)
2527 {
2528         struct virtnet_info *vi = netdev_priv(dev);
2529         u64 offloads;
2530         int err;
2531
2532         if ((dev->features ^ features) & NETIF_F_LRO) {
2533                 if (vi->xdp_queue_pairs)
2534                         return -EBUSY;
2535
2536                 if (features & NETIF_F_LRO)
2537                         offloads = vi->guest_offloads_capable;
2538                 else
2539                         offloads = vi->guest_offloads_capable &
2540                                    ~GUEST_OFFLOAD_LRO_MASK;
2541
2542                 err = virtnet_set_guest_offloads(vi, offloads);
2543                 if (err)
2544                         return err;
2545                 vi->guest_offloads = offloads;
2546         }
2547
2548         return 0;
2549 }
2550
2551 static const struct net_device_ops virtnet_netdev = {
2552         .ndo_open            = virtnet_open,
2553         .ndo_stop            = virtnet_close,
2554         .ndo_start_xmit      = start_xmit,
2555         .ndo_validate_addr   = eth_validate_addr,
2556         .ndo_set_mac_address = virtnet_set_mac_address,
2557         .ndo_set_rx_mode     = virtnet_set_rx_mode,
2558         .ndo_get_stats64     = virtnet_stats,
2559         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2560         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2561         .ndo_bpf                = virtnet_xdp,
2562         .ndo_xdp_xmit           = virtnet_xdp_xmit,
2563         .ndo_features_check     = passthru_features_check,
2564         .ndo_get_phys_port_name = virtnet_get_phys_port_name,
2565         .ndo_set_features       = virtnet_set_features,
2566 };
2567
2568 static void virtnet_config_changed_work(struct work_struct *work)
2569 {
2570         struct virtnet_info *vi =
2571                 container_of(work, struct virtnet_info, config_work);
2572         u16 v;
2573
2574         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2575                                  struct virtio_net_config, status, &v) < 0)
2576                 return;
2577
2578         if (v & VIRTIO_NET_S_ANNOUNCE) {
2579                 netdev_notify_peers(vi->dev);
2580                 virtnet_ack_link_announce(vi);
2581         }
2582
2583         /* Ignore unknown (future) status bits */
2584         v &= VIRTIO_NET_S_LINK_UP;
2585
2586         if (vi->status == v)
2587                 return;
2588
2589         vi->status = v;
2590
2591         if (vi->status & VIRTIO_NET_S_LINK_UP) {
2592                 virtnet_update_settings(vi);
2593                 netif_carrier_on(vi->dev);
2594                 netif_tx_wake_all_queues(vi->dev);
2595         } else {
2596                 netif_carrier_off(vi->dev);
2597                 netif_tx_stop_all_queues(vi->dev);
2598         }
2599 }
2600
2601 static void virtnet_config_changed(struct virtio_device *vdev)
2602 {
2603         struct virtnet_info *vi = vdev->priv;
2604
2605         schedule_work(&vi->config_work);
2606 }
2607
2608 static void virtnet_free_queues(struct virtnet_info *vi)
2609 {
2610         int i;
2611
2612         for (i = 0; i < vi->max_queue_pairs; i++) {
2613                 __netif_napi_del(&vi->rq[i].napi);
2614                 __netif_napi_del(&vi->sq[i].napi);
2615         }
2616
2617         /* We called __netif_napi_del(),
2618          * we need to respect an RCU grace period before freeing vi->rq
2619          */
2620         synchronize_net();
2621
2622         kfree(vi->rq);
2623         kfree(vi->sq);
2624         kfree(vi->ctrl);
2625 }
2626
2627 static void _free_receive_bufs(struct virtnet_info *vi)
2628 {
2629         struct bpf_prog *old_prog;
2630         int i;
2631
2632         for (i = 0; i < vi->max_queue_pairs; i++) {
2633                 while (vi->rq[i].pages)
2634                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2635
2636                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2637                 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2638                 if (old_prog)
2639                         bpf_prog_put(old_prog);
2640         }
2641 }
2642
2643 static void free_receive_bufs(struct virtnet_info *vi)
2644 {
2645         rtnl_lock();
2646         _free_receive_bufs(vi);
2647         rtnl_unlock();
2648 }
2649
2650 static void free_receive_page_frags(struct virtnet_info *vi)
2651 {
2652         int i;
2653         for (i = 0; i < vi->max_queue_pairs; i++)
2654                 if (vi->rq[i].alloc_frag.page)
2655                         put_page(vi->rq[i].alloc_frag.page);
2656 }
2657
2658 static void free_unused_bufs(struct virtnet_info *vi)
2659 {
2660         void *buf;
2661         int i;
2662
2663         for (i = 0; i < vi->max_queue_pairs; i++) {
2664                 struct virtqueue *vq = vi->sq[i].vq;
2665                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2666                         if (!is_xdp_frame(buf))
2667                                 dev_kfree_skb(buf);
2668                         else
2669                                 xdp_return_frame(ptr_to_xdp(buf));
2670                 }
2671         }
2672
2673         for (i = 0; i < vi->max_queue_pairs; i++) {
2674                 struct virtqueue *vq = vi->rq[i].vq;
2675
2676                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2677                         if (vi->mergeable_rx_bufs) {
2678                                 put_page(virt_to_head_page(buf));
2679                         } else if (vi->big_packets) {
2680                                 give_pages(&vi->rq[i], buf);
2681                         } else {
2682                                 put_page(virt_to_head_page(buf));
2683                         }
2684                 }
2685         }
2686 }
2687
2688 static void virtnet_del_vqs(struct virtnet_info *vi)
2689 {
2690         struct virtio_device *vdev = vi->vdev;
2691
2692         virtnet_clean_affinity(vi);
2693
2694         vdev->config->del_vqs(vdev);
2695
2696         virtnet_free_queues(vi);
2697 }
2698
2699 /* How large should a single buffer be so a queue full of these can fit at
2700  * least one full packet?
2701  * Logic below assumes the mergeable buffer header is used.
2702  */
2703 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2704 {
2705         const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2706         unsigned int rq_size = virtqueue_get_vring_size(vq);
2707         unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2708         unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2709         unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2710
2711         return max(max(min_buf_len, hdr_len) - hdr_len,
2712                    (unsigned int)GOOD_PACKET_LEN);
2713 }
2714
2715 static int virtnet_find_vqs(struct virtnet_info *vi)
2716 {
2717         vq_callback_t **callbacks;
2718         struct virtqueue **vqs;
2719         int ret = -ENOMEM;
2720         int i, total_vqs;
2721         const char **names;
2722         bool *ctx;
2723
2724         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2725          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2726          * possible control vq.
2727          */
2728         total_vqs = vi->max_queue_pairs * 2 +
2729                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2730
2731         /* Allocate space for find_vqs parameters */
2732         vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
2733         if (!vqs)
2734                 goto err_vq;
2735         callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
2736         if (!callbacks)
2737                 goto err_callback;
2738         names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
2739         if (!names)
2740                 goto err_names;
2741         if (!vi->big_packets || vi->mergeable_rx_bufs) {
2742                 ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
2743                 if (!ctx)
2744                         goto err_ctx;
2745         } else {
2746                 ctx = NULL;
2747         }
2748
2749         /* Parameters for control virtqueue, if any */
2750         if (vi->has_cvq) {
2751                 callbacks[total_vqs - 1] = NULL;
2752                 names[total_vqs - 1] = "control";
2753         }
2754
2755         /* Allocate/initialize parameters for send/receive virtqueues */
2756         for (i = 0; i < vi->max_queue_pairs; i++) {
2757                 callbacks[rxq2vq(i)] = skb_recv_done;
2758                 callbacks[txq2vq(i)] = skb_xmit_done;
2759                 sprintf(vi->rq[i].name, "input.%d", i);
2760                 sprintf(vi->sq[i].name, "output.%d", i);
2761                 names[rxq2vq(i)] = vi->rq[i].name;
2762                 names[txq2vq(i)] = vi->sq[i].name;
2763                 if (ctx)
2764                         ctx[rxq2vq(i)] = true;
2765         }
2766
2767         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2768                                          names, ctx, NULL);
2769         if (ret)
2770                 goto err_find;
2771
2772         if (vi->has_cvq) {
2773                 vi->cvq = vqs[total_vqs - 1];
2774                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2775                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2776         }
2777
2778         for (i = 0; i < vi->max_queue_pairs; i++) {
2779                 vi->rq[i].vq = vqs[rxq2vq(i)];
2780                 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2781                 vi->sq[i].vq = vqs[txq2vq(i)];
2782         }
2783
2784         /* run here: ret == 0. */
2785
2786
2787 err_find:
2788         kfree(ctx);
2789 err_ctx:
2790         kfree(names);
2791 err_names:
2792         kfree(callbacks);
2793 err_callback:
2794         kfree(vqs);
2795 err_vq:
2796         return ret;
2797 }
2798
2799 static int virtnet_alloc_queues(struct virtnet_info *vi)
2800 {
2801         int i;
2802
2803         vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
2804         if (!vi->ctrl)
2805                 goto err_ctrl;
2806         vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
2807         if (!vi->sq)
2808                 goto err_sq;
2809         vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
2810         if (!vi->rq)
2811                 goto err_rq;
2812
2813         INIT_DELAYED_WORK(&vi->refill, refill_work);
2814         for (i = 0; i < vi->max_queue_pairs; i++) {
2815                 vi->rq[i].pages = NULL;
2816                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2817                                napi_weight);
2818                 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2819                                   napi_tx ? napi_weight : 0);
2820
2821                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2822                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2823                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2824
2825                 u64_stats_init(&vi->rq[i].stats.syncp);
2826                 u64_stats_init(&vi->sq[i].stats.syncp);
2827         }
2828
2829         return 0;
2830
2831 err_rq:
2832         kfree(vi->sq);
2833 err_sq:
2834         kfree(vi->ctrl);
2835 err_ctrl:
2836         return -ENOMEM;
2837 }
2838
2839 static int init_vqs(struct virtnet_info *vi)
2840 {
2841         int ret;
2842
2843         /* Allocate send & receive queues */
2844         ret = virtnet_alloc_queues(vi);
2845         if (ret)
2846                 goto err;
2847
2848         ret = virtnet_find_vqs(vi);
2849         if (ret)
2850                 goto err_free;
2851
2852         get_online_cpus();
2853         virtnet_set_affinity(vi);
2854         put_online_cpus();
2855
2856         return 0;
2857
2858 err_free:
2859         virtnet_free_queues(vi);
2860 err:
2861         return ret;
2862 }
2863
2864 #ifdef CONFIG_SYSFS
2865 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2866                 char *buf)
2867 {
2868         struct virtnet_info *vi = netdev_priv(queue->dev);
2869         unsigned int queue_index = get_netdev_rx_queue_index(queue);
2870         unsigned int headroom = virtnet_get_headroom(vi);
2871         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
2872         struct ewma_pkt_len *avg;
2873
2874         BUG_ON(queue_index >= vi->max_queue_pairs);
2875         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2876         return sprintf(buf, "%u\n",
2877                        get_mergeable_buf_len(&vi->rq[queue_index], avg,
2878                                        SKB_DATA_ALIGN(headroom + tailroom)));
2879 }
2880
2881 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2882         __ATTR_RO(mergeable_rx_buffer_size);
2883
2884 static struct attribute *virtio_net_mrg_rx_attrs[] = {
2885         &mergeable_rx_buffer_size_attribute.attr,
2886         NULL
2887 };
2888
2889 static const struct attribute_group virtio_net_mrg_rx_group = {
2890         .name = "virtio_net",
2891         .attrs = virtio_net_mrg_rx_attrs
2892 };
2893 #endif
2894
2895 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2896                                     unsigned int fbit,
2897                                     const char *fname, const char *dname)
2898 {
2899         if (!virtio_has_feature(vdev, fbit))
2900                 return false;
2901
2902         dev_err(&vdev->dev, "device advertises feature %s but not %s",
2903                 fname, dname);
2904
2905         return true;
2906 }
2907
2908 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
2909         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2910
2911 static bool virtnet_validate_features(struct virtio_device *vdev)
2912 {
2913         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2914             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2915                              "VIRTIO_NET_F_CTRL_VQ") ||
2916              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2917                              "VIRTIO_NET_F_CTRL_VQ") ||
2918              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2919                              "VIRTIO_NET_F_CTRL_VQ") ||
2920              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2921              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2922                              "VIRTIO_NET_F_CTRL_VQ"))) {
2923                 return false;
2924         }
2925
2926         return true;
2927 }
2928
2929 #define MIN_MTU ETH_MIN_MTU
2930 #define MAX_MTU ETH_MAX_MTU
2931
2932 static int virtnet_validate(struct virtio_device *vdev)
2933 {
2934         if (!vdev->config->get) {
2935                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2936                         __func__);
2937                 return -EINVAL;
2938         }
2939
2940         if (!virtnet_validate_features(vdev))
2941                 return -EINVAL;
2942
2943         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2944                 int mtu = virtio_cread16(vdev,
2945                                          offsetof(struct virtio_net_config,
2946                                                   mtu));
2947                 if (mtu < MIN_MTU)
2948                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2949         }
2950
2951         return 0;
2952 }
2953
2954 static int virtnet_probe(struct virtio_device *vdev)
2955 {
2956         int i, err = -ENOMEM;
2957         struct net_device *dev;
2958         struct virtnet_info *vi;
2959         u16 max_queue_pairs;
2960         int mtu;
2961
2962         /* Find if host supports multiqueue virtio_net device */
2963         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2964                                    struct virtio_net_config,
2965                                    max_virtqueue_pairs, &max_queue_pairs);
2966
2967         /* We need at least 2 queue's */
2968         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
2969             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
2970             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2971                 max_queue_pairs = 1;
2972
2973         /* Allocate ourselves a network device with room for our info */
2974         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
2975         if (!dev)
2976                 return -ENOMEM;
2977
2978         /* Set up network device as normal. */
2979         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
2980         dev->netdev_ops = &virtnet_netdev;
2981         dev->features = NETIF_F_HIGHDMA;
2982
2983         dev->ethtool_ops = &virtnet_ethtool_ops;
2984         SET_NETDEV_DEV(dev, &vdev->dev);
2985
2986         /* Do we support "hardware" checksums? */
2987         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
2988                 /* This opens up the world of extra features. */
2989                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2990                 if (csum)
2991                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2992
2993                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
2994                         dev->hw_features |= NETIF_F_TSO
2995                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
2996                 }
2997                 /* Individual feature bits: what can host handle? */
2998                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
2999                         dev->hw_features |= NETIF_F_TSO;
3000                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3001                         dev->hw_features |= NETIF_F_TSO6;
3002                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3003                         dev->hw_features |= NETIF_F_TSO_ECN;
3004
3005                 dev->features |= NETIF_F_GSO_ROBUST;
3006
3007                 if (gso)
3008                         dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3009                 /* (!csum && gso) case will be fixed by register_netdev() */
3010         }
3011         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3012                 dev->features |= NETIF_F_RXCSUM;
3013         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3014             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3015                 dev->features |= NETIF_F_LRO;
3016         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3017                 dev->hw_features |= NETIF_F_LRO;
3018
3019         dev->vlan_features = dev->features;
3020
3021         /* MTU range: 68 - 65535 */
3022         dev->min_mtu = MIN_MTU;
3023         dev->max_mtu = MAX_MTU;
3024
3025         /* Configuration may specify what MAC to use.  Otherwise random. */
3026         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
3027                 virtio_cread_bytes(vdev,
3028                                    offsetof(struct virtio_net_config, mac),
3029                                    dev->dev_addr, dev->addr_len);
3030         else
3031                 eth_hw_addr_random(dev);
3032
3033         /* Set up our device-specific information */
3034         vi = netdev_priv(dev);
3035         vi->dev = dev;
3036         vi->vdev = vdev;
3037         vdev->priv = vi;
3038
3039         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3040
3041         /* If we can receive ANY GSO packets, we must allocate large ones. */
3042         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3043             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3044             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
3045             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
3046                 vi->big_packets = true;
3047
3048         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
3049                 vi->mergeable_rx_bufs = true;
3050
3051         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
3052             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3053                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
3054         else
3055                 vi->hdr_len = sizeof(struct virtio_net_hdr);
3056
3057         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
3058             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3059                 vi->any_header_sg = true;
3060
3061         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3062                 vi->has_cvq = true;
3063
3064         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3065                 mtu = virtio_cread16(vdev,
3066                                      offsetof(struct virtio_net_config,
3067                                               mtu));
3068                 if (mtu < dev->min_mtu) {
3069                         /* Should never trigger: MTU was previously validated
3070                          * in virtnet_validate.
3071                          */
3072                         dev_err(&vdev->dev,
3073                                 "device MTU appears to have changed it is now %d < %d",
3074                                 mtu, dev->min_mtu);
3075                         goto free;
3076                 }
3077
3078                 dev->mtu = mtu;
3079                 dev->max_mtu = mtu;
3080
3081                 /* TODO: size buffers correctly in this case. */
3082                 if (dev->mtu > ETH_DATA_LEN)
3083                         vi->big_packets = true;
3084         }
3085
3086         if (vi->any_header_sg)
3087                 dev->needed_headroom = vi->hdr_len;
3088
3089         /* Enable multiqueue by default */
3090         if (num_online_cpus() >= max_queue_pairs)
3091                 vi->curr_queue_pairs = max_queue_pairs;
3092         else
3093                 vi->curr_queue_pairs = num_online_cpus();
3094         vi->max_queue_pairs = max_queue_pairs;
3095
3096         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
3097         err = init_vqs(vi);
3098         if (err)
3099                 goto free;
3100
3101 #ifdef CONFIG_SYSFS
3102         if (vi->mergeable_rx_bufs)
3103                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
3104 #endif
3105         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
3106         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
3107
3108         virtnet_init_settings(dev);
3109
3110         if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3111                 vi->failover = net_failover_create(vi->dev);
3112                 if (IS_ERR(vi->failover)) {
3113                         err = PTR_ERR(vi->failover);
3114                         goto free_vqs;
3115                 }
3116         }
3117
3118         err = register_netdev(dev);
3119         if (err) {
3120                 pr_debug("virtio_net: registering device failed\n");
3121                 goto free_failover;
3122         }
3123
3124         virtio_device_ready(vdev);
3125
3126         err = virtnet_cpu_notif_add(vi);
3127         if (err) {
3128                 pr_debug("virtio_net: registering cpu notifier failed\n");
3129                 goto free_unregister_netdev;
3130         }
3131
3132         virtnet_set_queues(vi, vi->curr_queue_pairs);
3133
3134         /* Assume link up if device can't report link status,
3135            otherwise get link status from config. */
3136         netif_carrier_off(dev);
3137         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
3138                 schedule_work(&vi->config_work);
3139         } else {
3140                 vi->status = VIRTIO_NET_S_LINK_UP;
3141                 virtnet_update_settings(vi);
3142                 netif_carrier_on(dev);
3143         }
3144
3145         for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
3146                 if (virtio_has_feature(vi->vdev, guest_offloads[i]))
3147                         set_bit(guest_offloads[i], &vi->guest_offloads);
3148         vi->guest_offloads_capable = vi->guest_offloads;
3149
3150         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
3151                  dev->name, max_queue_pairs);
3152
3153         return 0;
3154
3155 free_unregister_netdev:
3156         vi->vdev->config->reset(vdev);
3157
3158         unregister_netdev(dev);
3159 free_failover:
3160         net_failover_destroy(vi->failover);
3161 free_vqs:
3162         cancel_delayed_work_sync(&vi->refill);
3163         free_receive_page_frags(vi);
3164         virtnet_del_vqs(vi);
3165 free:
3166         free_netdev(dev);
3167         return err;
3168 }
3169
3170 static void remove_vq_common(struct virtnet_info *vi)
3171 {
3172         vi->vdev->config->reset(vi->vdev);
3173
3174         /* Free unused buffers in both send and recv, if any. */
3175         free_unused_bufs(vi);
3176
3177         free_receive_bufs(vi);
3178
3179         free_receive_page_frags(vi);
3180
3181         virtnet_del_vqs(vi);
3182 }
3183
3184 static void virtnet_remove(struct virtio_device *vdev)
3185 {
3186         struct virtnet_info *vi = vdev->priv;
3187
3188         virtnet_cpu_notif_remove(vi);
3189
3190         /* Make sure no work handler is accessing the device. */
3191         flush_work(&vi->config_work);
3192
3193         unregister_netdev(vi->dev);
3194
3195         net_failover_destroy(vi->failover);
3196
3197         remove_vq_common(vi);
3198
3199         free_netdev(vi->dev);
3200 }
3201
3202 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
3203 {
3204         struct virtnet_info *vi = vdev->priv;
3205
3206         virtnet_cpu_notif_remove(vi);
3207         virtnet_freeze_down(vdev);
3208         remove_vq_common(vi);
3209
3210         return 0;
3211 }
3212
3213 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
3214 {
3215         struct virtnet_info *vi = vdev->priv;
3216         int err;
3217
3218         err = virtnet_restore_up(vdev);
3219         if (err)
3220                 return err;
3221         virtnet_set_queues(vi, vi->curr_queue_pairs);
3222
3223         err = virtnet_cpu_notif_add(vi);
3224         if (err)
3225                 return err;
3226
3227         return 0;
3228 }
3229
3230 static struct virtio_device_id id_table[] = {
3231         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
3232         { 0 },
3233 };
3234
3235 #define VIRTNET_FEATURES \
3236         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
3237         VIRTIO_NET_F_MAC, \
3238         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
3239         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
3240         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
3241         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
3242         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
3243         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
3244         VIRTIO_NET_F_CTRL_MAC_ADDR, \
3245         VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
3246         VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
3247
3248 static unsigned int features[] = {
3249         VIRTNET_FEATURES,
3250 };
3251
3252 static unsigned int features_legacy[] = {
3253         VIRTNET_FEATURES,
3254         VIRTIO_NET_F_GSO,
3255         VIRTIO_F_ANY_LAYOUT,
3256 };
3257
3258 static struct virtio_driver virtio_net_driver = {
3259         .feature_table = features,
3260         .feature_table_size = ARRAY_SIZE(features),
3261         .feature_table_legacy = features_legacy,
3262         .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
3263         .driver.name =  KBUILD_MODNAME,
3264         .driver.owner = THIS_MODULE,
3265         .id_table =     id_table,
3266         .validate =     virtnet_validate,
3267         .probe =        virtnet_probe,
3268         .remove =       virtnet_remove,
3269         .config_changed = virtnet_config_changed,
3270 #ifdef CONFIG_PM_SLEEP
3271         .freeze =       virtnet_freeze,
3272         .restore =      virtnet_restore,
3273 #endif
3274 };
3275
3276 static __init int virtio_net_driver_init(void)
3277 {
3278         int ret;
3279
3280         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
3281                                       virtnet_cpu_online,
3282                                       virtnet_cpu_down_prep);
3283         if (ret < 0)
3284                 goto out;
3285         virtionet_online = ret;
3286         ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
3287                                       NULL, virtnet_cpu_dead);
3288         if (ret)
3289                 goto err_dead;
3290
3291         ret = register_virtio_driver(&virtio_net_driver);
3292         if (ret)
3293                 goto err_virtio;
3294         return 0;
3295 err_virtio:
3296         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3297 err_dead:
3298         cpuhp_remove_multi_state(virtionet_online);
3299 out:
3300         return ret;
3301 }
3302 module_init(virtio_net_driver_init);
3303
3304 static __exit void virtio_net_driver_exit(void)
3305 {
3306         unregister_virtio_driver(&virtio_net_driver);
3307         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3308         cpuhp_remove_multi_state(virtionet_online);
3309 }
3310 module_exit(virtio_net_driver_exit);
3311
3312 MODULE_DEVICE_TABLE(virtio, id_table);
3313 MODULE_DESCRIPTION("Virtio network driver");
3314 MODULE_LICENSE("GPL");