linux/drivers/net/virtio_net.c
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   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
  26static int napi_weight = NAPI_POLL_WEIGHT;
  27module_param(napi_weight, int, 0444);
  28
  29static bool csum = true, gso = true, napi_tx = true;
  30module_param(csum, bool, 0444);
  31module_param(gso, bool, 0444);
  32module_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 */
  54DECLARE_EWMA(pkt_len, 0, 64)
  55
  56#define VIRTNET_DRIVER_VERSION "1.0.0"
  57
  58static 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
  71struct virtnet_stat_desc {
  72        char desc[ETH_GSTRING_LEN];
  73        size_t offset;
  74};
  75
  76struct 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
  85struct 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
 100static 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
 108static 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 */
 123struct 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.$index */
 131        char name[40];
 132
 133        struct virtnet_sq_stats stats;
 134
 135        struct napi_struct napi;
 136};
 137
 138/* Internal representation of a receive virtqueue */
 139struct receive_queue {
 140        /* Virtqueue associated with this receive_queue */
 141        struct virtqueue *vq;
 142
 143        struct napi_struct napi;
 144
 145        struct bpf_prog __rcu *xdp_prog;
 146
 147        struct virtnet_rq_stats stats;
 148
 149        /* Chain pages by the private ptr. */
 150        struct page *pages;
 151
 152        /* Average packet length for mergeable receive buffers. */
 153        struct ewma_pkt_len mrg_avg_pkt_len;
 154
 155        /* Page frag for packet buffer allocation. */
 156        struct page_frag alloc_frag;
 157
 158        /* RX: fragments + linear part + virtio header */
 159        struct scatterlist sg[MAX_SKB_FRAGS + 2];
 160
 161        /* Min single buffer size for mergeable buffers case. */
 162        unsigned int min_buf_len;
 163
 164        /* Name of this receive queue: input.$index */
 165        char name[40];
 166
 167        struct xdp_rxq_info xdp_rxq;
 168};
 169
 170/* Control VQ buffers: protected by the rtnl lock */
 171struct 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
 181struct 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
 239struct 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
 249static bool is_xdp_frame(void *ptr)
 250{
 251        return (unsigned long)ptr & VIRTIO_XDP_FLAG;
 252}
 253
 254static void *xdp_to_ptr(struct xdp_frame *ptr)
 255{
 256        return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
 257}
 258
 259static 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 */
 267static int vq2txq(struct virtqueue *vq)
 268{
 269        return (vq->index - 1) / 2;
 270}
 271
 272static int txq2vq(int txq)
 273{
 274        return txq * 2 + 1;
 275}
 276
 277static int vq2rxq(struct virtqueue *vq)
 278{
 279        return vq->index / 2;
 280}
 281
 282static int rxq2vq(int rxq)
 283{
 284        return rxq * 2;
 285}
 286
 287static 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 */
 296static 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
 306static 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
 319static 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
 328static 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
 342static 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
 358static 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
 364static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
 365{
 366        return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
 367}
 368
 369static 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 */
 375static 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
 457static 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
 484static 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
 492static 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        }
 554out:
 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
 566static 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 */
 585static 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;
 630err_buf:
 631        __free_pages(page, 0);
 632        return NULL;
 633}
 634
 635static 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
 756err:
 757        return skb;
 758
 759err_xdp:
 760        rcu_read_unlock();
 761        stats->xdp_drops++;
 762        stats->drops++;
 763        put_page(page);
 764xdp_xmit:
 765        return NULL;
 766}
 767
 768static 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
 785err:
 786        stats->drops++;
 787        give_pages(rq, page);
 788        return NULL;
 789}
 790
 791static 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
1012err_xdp:
1013        rcu_read_unlock();
1014        stats->xdp_drops++;
1015err_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        }
1029err_buf:
1030        stats->drops++;
1031        dev_kfree_skb(head_skb);
1032xdp_xmit:
1033        return NULL;
1034}
1035
1036static 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
1090frame_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 */
1100static 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
1126static 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
1175static 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
1191static 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 */
1241static 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
1270static 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
1278static 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
1291static 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
1309static void virtnet_napi_tx_disable(struct napi_struct *napi)
1310{
1311        if (napi->weight)
1312                napi_disable(napi);
1313}
1314
1315static 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
1337static 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
1380static 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
1416static 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
1426static 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
1445static 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
1477static 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);
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
1506static 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
1532static 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
1579static 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 */
1658static 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
1697static 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
1739out:
1740        kfree(addr);
1741        return ret;
1742}
1743
1744static 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
1782static 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
1791static 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
1817static 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
1827static 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
1844static 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
1914static 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
1929static 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
1944static 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
1958static 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
1997static 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
2005static 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
2013static 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
2022static enum cpuhp_state virtionet_online;
2023
2024static 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
2039static 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
2046static 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
2058static 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 */
2071static 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
2107static 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
2134static 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
2147static 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
2184static 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
2197static 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
2206static 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
2218static 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
2239static 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
2256static 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
2264static 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
2283static 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
2300static 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
2321static int init_vqs(struct virtnet_info *vi);
2322
2323static 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
2352static 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
2368static 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
2378static 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
2388static 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
2480err:
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
2499static 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
2509static 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
2525static 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
2551static 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
2568static 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
2601static 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
2608static 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
2627static 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
2643static void free_receive_bufs(struct virtnet_info *vi)
2644{
2645        rtnl_lock();
2646        _free_receive_bufs(vi);
2647        rtnl_unlock();
2648}
2649
2650static 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
2658static 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
2688static 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 */
2703static 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
2715static 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
2787err_find:
2788        kfree(ctx);
2789err_ctx:
2790        kfree(names);
2791err_names:
2792        kfree(callbacks);
2793err_callback:
2794        kfree(vqs);
2795err_vq:
2796        return ret;
2797}
2798
2799static 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
2831err_rq:
2832        kfree(vi->sq);
2833err_sq:
2834        kfree(vi->ctrl);
2835err_ctrl:
2836        return -ENOMEM;
2837}
2838
2839static 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
2858err_free:
2859        virtnet_free_queues(vi);
2860err:
2861        return ret;
2862}
2863
2864#ifdef CONFIG_SYSFS
2865static 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
2881static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2882        __ATTR_RO(mergeable_rx_buffer_size);
2883
2884static struct attribute *virtio_net_mrg_rx_attrs[] = {
2885        &mergeable_rx_buffer_size_attribute.attr,
2886        NULL
2887};
2888
2889static const struct attribute_group virtio_net_mrg_rx_group = {
2890        .name = "virtio_net",
2891        .attrs = virtio_net_mrg_rx_attrs
2892};
2893#endif
2894
2895static 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
2911static 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
2932static 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
2954static 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
3155free_unregister_netdev:
3156        vi->vdev->config->reset(vdev);
3157
3158        unregister_netdev(dev);
3159free_failover:
3160        net_failover_destroy(vi->failover);
3161free_vqs:
3162        cancel_delayed_work_sync(&vi->refill);
3163        free_receive_page_frags(vi);
3164        virtnet_del_vqs(vi);
3165free:
3166        free_netdev(dev);
3167        return err;
3168}
3169
3170static 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
3184static 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
3202static __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
3213static __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
3230static 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
3248static unsigned int features[] = {
3249        VIRTNET_FEATURES,
3250};
3251
3252static unsigned int features_legacy[] = {
3253        VIRTNET_FEATURES,
3254        VIRTIO_NET_F_GSO,
3255        VIRTIO_F_ANY_LAYOUT,
3256};
3257
3258static 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
3276static __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;
3295err_virtio:
3296        cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3297err_dead:
3298        cpuhp_remove_multi_state(virtionet_online);
3299out:
3300        return ret;
3301}
3302module_init(virtio_net_driver_init);
3303
3304static __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}
3310module_exit(virtio_net_driver_exit);
3311
3312MODULE_DEVICE_TABLE(virtio, id_table);
3313MODULE_DESCRIPTION("Virtio network driver");
3314MODULE_LICENSE("GPL");
3315