drivers/net/virtio_net.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* A network driver using virtio.
   3  *
   4  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
   5  */
   6 //#define DEBUG
   7 #include <linux/netdevice.h>
   8 #include <linux/etherdevice.h>
   9 #include <linux/ethtool.h>
  10 #include <linux/module.h>
  11 #include <linux/virtio.h>
  12 #include <linux/virtio_net.h>
  13 #include <linux/bpf.h>
  14 #include <linux/bpf_trace.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/if_vlan.h>
  17 #include <linux/slab.h>
  18 #include <linux/cpu.h>
  19 #include <linux/average.h>
  20 #include <linux/filter.h>
  21 #include <linux/kernel.h>
  22 #include <net/route.h>
  23 #include <net/xdp.h>
  24 #include <net/net_failover.h>
  25
  26 static int napi_weight = NAPI_POLL_WEIGHT;
  27 module_param(napi_weight, int, 0444);
  28
  29 static bool csum = true, gso = true, napi_tx = true;
  30 module_param(csum, bool, 0444);
  31 module_param(gso, bool, 0444);
  32 module_param(napi_tx, bool, 0644);
  33
  34 /* FIXME: MTU in config. */
  35 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  36 #define GOOD_COPY_LEN   128
  37
  38 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
  39
  40 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
  41 #define VIRTIO_XDP_HEADROOM 256
  42
  43 /* Separating two types of XDP xmit */
  44 #define VIRTIO_XDP_TX           BIT(0)
  45 #define VIRTIO_XDP_REDIR        BIT(1)
  46
  47 #define VIRTIO_XDP_FLAG BIT(0)
  48
  49 /* RX packet size EWMA. The average packet size is used to determine the packet
  50  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  51  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  52  * term, transient changes in packet size.
  53  */
  54 DECLARE_EWMA(pkt_len, 0, 64)
  55
  56 #define VIRTNET_DRIVER_VERSION "1.0.0"
  57
  58 static const unsigned long guest_offloads[] = {
  59         VIRTIO_NET_F_GUEST_TSO4,
  60         VIRTIO_NET_F_GUEST_TSO6,
  61         VIRTIO_NET_F_GUEST_ECN,
  62         VIRTIO_NET_F_GUEST_UFO,
  63         VIRTIO_NET_F_GUEST_CSUM
  64 };
  65
  66 #define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
  67                                 (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
  68                                 (1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
  69                                 (1ULL << VIRTIO_NET_F_GUEST_UFO))
  70
  71 struct virtnet_stat_desc {
  72         char desc[ETH_GSTRING_LEN];
  73         size_t offset;
  74 };
  75
  76 struct virtnet_sq_stats {
  77         struct u64_stats_sync syncp;
  78         u64 packets;
  79         u64 bytes;
  80         u64 xdp_tx;
  81         u64 xdp_tx_drops;
  82         u64 kicks;
  83 };
  84
  85 struct virtnet_rq_stats {
  86         struct u64_stats_sync syncp;
  87         u64 packets;
  88         u64 bytes;
  89         u64 drops;
  90         u64 xdp_packets;
  91         u64 xdp_tx;
  92         u64 xdp_redirects;
  93         u64 xdp_drops;
  94         u64 kicks;
  95 };
  96
  97 #define VIRTNET_SQ_STAT(m)      offsetof(struct virtnet_sq_stats, m)
  98 #define VIRTNET_RQ_STAT(m)      offsetof(struct virtnet_rq_stats, m)
  99
 100 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
 101         { "packets",            VIRTNET_SQ_STAT(packets) },
 102         { "bytes",              VIRTNET_SQ_STAT(bytes) },
 103         { "xdp_tx",             VIRTNET_SQ_STAT(xdp_tx) },
 104         { "xdp_tx_drops",       VIRTNET_SQ_STAT(xdp_tx_drops) },
 105         { "kicks",              VIRTNET_SQ_STAT(kicks) },
 106 };
 107
 108 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
 109         { "packets",            VIRTNET_RQ_STAT(packets) },
 110         { "bytes",              VIRTNET_RQ_STAT(bytes) },
 111         { "drops",              VIRTNET_RQ_STAT(drops) },
 112         { "xdp_packets",        VIRTNET_RQ_STAT(xdp_packets) },
 113         { "xdp_tx",             VIRTNET_RQ_STAT(xdp_tx) },
 114         { "xdp_redirects",      VIRTNET_RQ_STAT(xdp_redirects) },
 115         { "xdp_drops",          VIRTNET_RQ_STAT(xdp_drops) },
 116         { "kicks",              VIRTNET_RQ_STAT(kicks) },
 117 };
 118
 119 #define VIRTNET_SQ_STATS_LEN    ARRAY_SIZE(virtnet_sq_stats_desc)
 120 #define VIRTNET_RQ_STATS_LEN    ARRAY_SIZE(virtnet_rq_stats_desc)
 121
 122 /* Internal representation of a send virtqueue */
 123 struct send_queue {
 124         /* Virtqueue associated with this send _queue */
 125         struct virtqueue *vq;
 126
 127         /* TX: fragments + linear part + virtio header */
 128         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 129
 130         /* Name of the send queue: output.$index */
 131         char name[40];
 132
 133         struct virtnet_sq_stats stats;
 134
 135         struct napi_struct napi;
 136 };
 137
 138 /* Internal representation of a receive virtqueue */
 139 struct receive_queue {
 140         /* Virtqueue associated with this receive_queue */
 141         struct virtqueue *vq;
 142
 143         struct napi_struct napi;
 144
 145         struct bpf_prog __rcu *xdp_prog;
 146
 147         struct virtnet_rq_stats stats;
 148
 149         /* Chain pages by the private ptr. */
 150         struct page *pages;
 151
 152         /* Average packet length for mergeable receive buffers. */
 153         struct ewma_pkt_len mrg_avg_pkt_len;
 154
 155         /* Page frag for packet buffer allocation. */
 156         struct page_frag alloc_frag;
 157
 158         /* RX: fragments + linear part + virtio header */
 159         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 160
 161         /* Min single buffer size for mergeable buffers case. */
 162         unsigned int min_buf_len;
 163
 164         /* Name of this receive queue: input.$index */
 165         char name[40];
 166
 167         struct xdp_rxq_info xdp_rxq;
 168 };
 169
 170 /* Control VQ buffers: protected by the rtnl lock */
 171 struct control_buf {
 172         struct virtio_net_ctrl_hdr hdr;
 173         virtio_net_ctrl_ack status;
 174         struct virtio_net_ctrl_mq mq;
 175         u8 promisc;
 176         u8 allmulti;
 177         __virtio16 vid;
 178         __virtio64 offloads;
 179 };
 180
 181 struct virtnet_info {
 182         struct virtio_device *vdev;
 183         struct virtqueue *cvq;
 184         struct net_device *dev;
 185         struct send_queue *sq;
 186         struct receive_queue *rq;
 187         unsigned int status;
 188
 189         /* Max # of queue pairs supported by the device */
 190         u16 max_queue_pairs;
 191
 192         /* # of queue pairs currently used by the driver */
 193         u16 curr_queue_pairs;
 194
 195         /* # of XDP queue pairs currently used by the driver */
 196         u16 xdp_queue_pairs;
 197
 198         /* xdp_queue_pairs may be 0, when xdp is already loaded. So add this. */
 199         bool xdp_enabled;
 200
 201         /* I like... big packets and I cannot lie! */
 202         bool big_packets;
 203
 204         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 205         bool mergeable_rx_bufs;
 206
 207         /* Has control virtqueue */
 208         bool has_cvq;
 209
 210         /* Host can handle any s/g split between our header and packet data */
 211         bool any_header_sg;
 212
 213         /* Packet virtio header size */
 214         u8 hdr_len;
 215
 216         /* Work struct for refilling if we run low on memory. */
 217         struct delayed_work refill;
 218
 219         /* Work struct for config space updates */
 220         struct work_struct config_work;
 221
 222         /* Does the affinity hint is set for virtqueues? */
 223         bool affinity_hint_set;
 224
 225         /* CPU hotplug instances for online & dead */
 226         struct hlist_node node;
 227         struct hlist_node node_dead;
 228
 229         struct control_buf *ctrl;
 230
 231         /* Ethtool settings */
 232         u8 duplex;
 233         u32 speed;
 234
 235         unsigned long guest_offloads;
 236         unsigned long guest_offloads_capable;
 237
 238         /* failover when STANDBY feature enabled */
 239         struct failover *failover;
 240 };
 241
 242 struct padded_vnet_hdr {
 243         struct virtio_net_hdr_mrg_rxbuf hdr;
 244         /*
 245          * hdr is in a separate sg buffer, and data sg buffer shares same page
 246          * with this header sg. This padding makes next sg 16 byte aligned
 247          * after the header.
 248          */
 249         char padding[4];
 250 };
 251
 252 static bool is_xdp_frame(void *ptr)
 253 {
 254         return (unsigned long)ptr & VIRTIO_XDP_FLAG;
 255 }
 256
 257 static void *xdp_to_ptr(struct xdp_frame *ptr)
 258 {
 259         return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
 260 }
 261
 262 static struct xdp_frame *ptr_to_xdp(void *ptr)
 263 {
 264         return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
 265 }
 266
 267 /* Converting between virtqueue no. and kernel tx/rx queue no.
 268  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 269  */
 270 static int vq2txq(struct virtqueue *vq)
 271 {
 272         return (vq->index - 1) / 2;
 273 }
 274
 275 static int txq2vq(int txq)
 276 {
 277         return txq * 2 + 1;
 278 }
 279
 280 static int vq2rxq(struct virtqueue *vq)
 281 {
 282         return vq->index / 2;
 283 }
 284
 285 static int rxq2vq(int rxq)
 286 {
 287         return rxq * 2;
 288 }
 289
 290 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 291 {
 292         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 293 }
 294
 295 /*
 296  * private is used to chain pages for big packets, put the whole
 297  * most recent used list in the beginning for reuse
 298  */
 299 static void give_pages(struct receive_queue *rq, struct page *page)
 300 {
 301         struct page *end;
 302
 303         /* Find end of list, sew whole thing into vi->rq.pages. */
 304         for (end = page; end->private; end = (struct page *)end->private);
 305         end->private = (unsigned long)rq->pages;
 306         rq->pages = page;
 307 }
 308
 309 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 310 {
 311         struct page *p = rq->pages;
 312
 313         if (p) {
 314                 rq->pages = (struct page *)p->private;
 315                 /* clear private here, it is used to chain pages */
 316                 p->private = 0;
 317         } else
 318                 p = alloc_page(gfp_mask);
 319         return p;
 320 }
 321
 322 static void virtqueue_napi_schedule(struct napi_struct *napi,
 323                                     struct virtqueue *vq)
 324 {
 325         if (napi_schedule_prep(napi)) {
 326                 virtqueue_disable_cb(vq);
 327                 __napi_schedule(napi);
 328         }
 329 }
 330
 331 static void virtqueue_napi_complete(struct napi_struct *napi,
 332                                     struct virtqueue *vq, int processed)
 333 {
 334         int opaque;
 335
 336         opaque = virtqueue_enable_cb_prepare(vq);
 337         if (napi_complete_done(napi, processed)) {
 338                 if (unlikely(virtqueue_poll(vq, opaque)))
 339                         virtqueue_napi_schedule(napi, vq);
 340         } else {
 341                 virtqueue_disable_cb(vq);
 342         }
 343 }
 344
 345 static void skb_xmit_done(struct virtqueue *vq)
 346 {
 347         struct virtnet_info *vi = vq->vdev->priv;
 348         struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
 349
 350         /* Suppress further interrupts. */
 351         virtqueue_disable_cb(vq);
 352
 353         if (napi->weight)
 354                 virtqueue_napi_schedule(napi, vq);
 355         else
 356                 /* We were probably waiting for more output buffers. */
 357                 netif_wake_subqueue(vi->dev, vq2txq(vq));
 358 }
 359
 360 #define MRG_CTX_HEADER_SHIFT 22
 361 static void *mergeable_len_to_ctx(unsigned int truesize,
 362                                   unsigned int headroom)
 363 {
 364         return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
 365 }
 366
 367 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
 368 {
 369         return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
 370 }
 371
 372 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
 373 {
 374         return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
 375 }
 376
 377 /* Called from bottom half context */
 378 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 379                                    struct receive_queue *rq,
 380                                    struct page *page, unsigned int offset,
 381                                    unsigned int len, unsigned int truesize,
 382                                    bool hdr_valid, unsigned int metasize,
 383                                    bool whole_page)
 384 {
 385         struct sk_buff *skb;
 386         struct virtio_net_hdr_mrg_rxbuf *hdr;
 387         unsigned int copy, hdr_len, hdr_padded_len;
 388         struct page *page_to_free = NULL;
 389         int tailroom, shinfo_size;
 390         char *p, *hdr_p, *buf;
 391
 392         p = page_address(page) + offset;
 393         hdr_p = p;
 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         /* If whole_page, there is an offset between the beginning of the
 402          * data and the allocated space, otherwise the data and the allocated
 403          * space are aligned.
 404          *
 405          * Buffers with headroom use PAGE_SIZE as alloc size, see
 406          * add_recvbuf_mergeable() + get_mergeable_buf_len()
 407          */
 408         if (whole_page) {
 409                 /* Buffers with whole_page use PAGE_SIZE as alloc size,
 410                  * see add_recvbuf_mergeable() + get_mergeable_buf_len()
 411                  */
 412                 truesize = PAGE_SIZE;
 413
 414                 /* page maybe head page, so we should get the buf by p, not the
 415                  * page
 416                  */
 417                 tailroom = truesize - len - offset_in_page(p);
 418                 buf = (char *)((unsigned long)p & PAGE_MASK);
 419         } else {
 420                 tailroom = truesize - len;
 421                 buf = p;
 422         }
 423
 424         len -= hdr_len;
 425         offset += hdr_padded_len;
 426         p += hdr_padded_len;
 427
 428         shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 429
 430         /* copy small packet so we can reuse these pages */
 431         if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) {
 432                 skb = build_skb(buf, truesize);
 433                 if (unlikely(!skb))
 434                         return NULL;
 435
 436                 skb_reserve(skb, p - buf);
 437                 skb_put(skb, len);
 438                 goto ok;
 439         }
 440
 441         /* copy small packet so we can reuse these pages for small data */
 442         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 443         if (unlikely(!skb))
 444                 return NULL;
 445
 446         /* Copy all frame if it fits skb->head, otherwise
 447          * we let virtio_net_hdr_to_skb() and GRO pull headers as needed.
 448          */
 449         if (len <= skb_tailroom(skb))
 450                 copy = len;
 451         else
 452                 copy = ETH_HLEN + metasize;
 453         skb_put_data(skb, p, copy);
 454
 455         len -= copy;
 456         offset += copy;
 457
 458         if (vi->mergeable_rx_bufs) {
 459                 if (len)
 460                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 461                 else
 462                         page_to_free = page;
 463                 goto ok;
 464         }
 465
 466         /*
 467          * Verify that we can indeed put this data into a skb.
 468          * This is here to handle cases when the device erroneously
 469          * tries to receive more than is possible. This is usually
 470          * the case of a broken device.
 471          */
 472         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 473                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 474                 dev_kfree_skb(skb);
 475                 return NULL;
 476         }
 477         BUG_ON(offset >= PAGE_SIZE);
 478         while (len) {
 479                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 480                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 481                                 frag_size, truesize);
 482                 len -= frag_size;
 483                 page = (struct page *)page->private;
 484                 offset = 0;
 485         }
 486
 487         if (page)
 488                 give_pages(rq, page);
 489
 490 ok:
 491         /* hdr_valid means no XDP, so we can copy the vnet header */
 492         if (hdr_valid) {
 493                 hdr = skb_vnet_hdr(skb);
 494                 memcpy(hdr, hdr_p, hdr_len);
 495         }
 496         if (page_to_free)
 497                 put_page(page_to_free);
 498
 499         if (metasize) {
 500                 __skb_pull(skb, metasize);
 501                 skb_metadata_set(skb, metasize);
 502         }
 503
 504         return skb;
 505 }
 506
 507 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
 508                                    struct send_queue *sq,
 509                                    struct xdp_frame *xdpf)
 510 {
 511         struct virtio_net_hdr_mrg_rxbuf *hdr;
 512         int err;
 513
 514         if (unlikely(xdpf->headroom < vi->hdr_len))
 515                 return -EOVERFLOW;
 516
 517         /* Make room for virtqueue hdr (also change xdpf->headroom?) */
 518         xdpf->data -= vi->hdr_len;
 519         /* Zero header and leave csum up to XDP layers */
 520         hdr = xdpf->data;
 521         memset(hdr, 0, vi->hdr_len);
 522         xdpf->len   += vi->hdr_len;
 523
 524         sg_init_one(sq->sg, xdpf->data, xdpf->len);
 525
 526         err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
 527                                    GFP_ATOMIC);
 528         if (unlikely(err))
 529                 return -ENOSPC; /* Caller handle free/refcnt */
 530
 531         return 0;
 532 }
 533
 534 /* when vi->curr_queue_pairs > nr_cpu_ids, the txq/sq is only used for xdp tx on
 535  * the current cpu, so it does not need to be locked.
 536  *
 537  * Here we use marco instead of inline functions because we have to deal with
 538  * three issues at the same time: 1. the choice of sq. 2. judge and execute the
 539  * lock/unlock of txq 3. make sparse happy. It is difficult for two inline
 540  * functions to perfectly solve these three problems at the same time.
 541  */
 542 #define virtnet_xdp_get_sq(vi) ({                                       \
 543         struct netdev_queue *txq;                                       \
 544         typeof(vi) v = (vi);                                            \
 545         unsigned int qp;                                                \
 546                                                                         \
 547         if (v->curr_queue_pairs > nr_cpu_ids) {                         \
 548                 qp = v->curr_queue_pairs - v->xdp_queue_pairs;          \
 549                 qp += smp_processor_id();                               \
 550                 txq = netdev_get_tx_queue(v->dev, qp);                  \
 551                 __netif_tx_acquire(txq);                                \
 552         } else {                                                        \
 553                 qp = smp_processor_id() % v->curr_queue_pairs;          \
 554                 txq = netdev_get_tx_queue(v->dev, qp);                  \
 555                 __netif_tx_lock(txq, raw_smp_processor_id());           \
 556         }                                                               \
 557         v->sq + qp;                                                     \
 558 })
 559
 560 #define virtnet_xdp_put_sq(vi, q) {                                     \
 561         struct netdev_queue *txq;                                       \
 562         typeof(vi) v = (vi);                                            \
 563                                                                         \
 564         txq = netdev_get_tx_queue(v->dev, (q) - v->sq);                 \
 565         if (v->curr_queue_pairs > nr_cpu_ids)                           \
 566                 __netif_tx_release(txq);                                \
 567         else                                                            \
 568                 __netif_tx_unlock(txq);                                 \
 569 }
 570
 571 static int virtnet_xdp_xmit(struct net_device *dev,
 572                             int n, struct xdp_frame **frames, u32 flags)
 573 {
 574         struct virtnet_info *vi = netdev_priv(dev);
 575         struct receive_queue *rq = vi->rq;
 576         struct bpf_prog *xdp_prog;
 577         struct send_queue *sq;
 578         unsigned int len;
 579         int packets = 0;
 580         int bytes = 0;
 581         int nxmit = 0;
 582         int kicks = 0;
 583         void *ptr;
 584         int ret;
 585         int i;
 586
 587         /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
 588          * indicate XDP resources have been successfully allocated.
 589          */
 590         xdp_prog = rcu_access_pointer(rq->xdp_prog);
 591         if (!xdp_prog)
 592                 return -ENXIO;
 593
 594         sq = virtnet_xdp_get_sq(vi);
 595
 596         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
 597                 ret = -EINVAL;
 598                 goto out;
 599         }
 600
 601         /* Free up any pending old buffers before queueing new ones. */
 602         while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 603                 if (likely(is_xdp_frame(ptr))) {
 604                         struct xdp_frame *frame = ptr_to_xdp(ptr);
 605
 606                         bytes += frame->len;
 607                         xdp_return_frame(frame);
 608                 } else {
 609                         struct sk_buff *skb = ptr;
 610
 611                         bytes += skb->len;
 612                         napi_consume_skb(skb, false);
 613                 }
 614                 packets++;
 615         }
 616
 617         for (i = 0; i < n; i++) {
 618                 struct xdp_frame *xdpf = frames[i];
 619
 620                 if (__virtnet_xdp_xmit_one(vi, sq, xdpf))
 621                         break;
 622                 nxmit++;
 623         }
 624         ret = nxmit;
 625
 626         if (flags & XDP_XMIT_FLUSH) {
 627                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
 628                         kicks = 1;
 629         }
 630 out:
 631         u64_stats_update_begin(&sq->stats.syncp);
 632         sq->stats.bytes += bytes;
 633         sq->stats.packets += packets;
 634         sq->stats.xdp_tx += n;
 635         sq->stats.xdp_tx_drops += n - nxmit;
 636         sq->stats.kicks += kicks;
 637         u64_stats_update_end(&sq->stats.syncp);
 638
 639         virtnet_xdp_put_sq(vi, sq);
 640         return ret;
 641 }
 642
 643 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
 644 {
 645         return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0;
 646 }
 647
 648 /* We copy the packet for XDP in the following cases:
 649  *
 650  * 1) Packet is scattered across multiple rx buffers.
 651  * 2) Headroom space is insufficient.
 652  *
 653  * This is inefficient but it's a temporary condition that
 654  * we hit right after XDP is enabled and until queue is refilled
 655  * with large buffers with sufficient headroom - so it should affect
 656  * at most queue size packets.
 657  * Afterwards, the conditions to enable
 658  * XDP should preclude the underlying device from sending packets
 659  * across multiple buffers (num_buf > 1), and we make sure buffers
 660  * have enough headroom.
 661  */
 662 static struct page *xdp_linearize_page(struct receive_queue *rq,
 663                                        u16 *num_buf,
 664                                        struct page *p,
 665                                        int offset,
 666                                        int page_off,
 667                                        unsigned int *len)
 668 {
 669         struct page *page = alloc_page(GFP_ATOMIC);
 670
 671         if (!page)
 672                 return NULL;
 673
 674         memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
 675         page_off += *len;
 676
 677         while (--*num_buf) {
 678                 int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 679                 unsigned int buflen;
 680                 void *buf;
 681                 int off;
 682
 683                 buf = virtqueue_get_buf(rq->vq, &buflen);
 684                 if (unlikely(!buf))
 685                         goto err_buf;
 686
 687                 p = virt_to_head_page(buf);
 688                 off = buf - page_address(p);
 689
 690                 /* guard against a misconfigured or uncooperative backend that
 691                  * is sending packet larger than the MTU.
 692                  */
 693                 if ((page_off + buflen + tailroom) > PAGE_SIZE) {
 694                         put_page(p);
 695                         goto err_buf;
 696                 }
 697
 698                 memcpy(page_address(page) + page_off,
 699                        page_address(p) + off, buflen);
 700                 page_off += buflen;
 701                 put_page(p);
 702         }
 703
 704         /* Headroom does not contribute to packet length */
 705         *len = page_off - VIRTIO_XDP_HEADROOM;
 706         return page;
 707 err_buf:
 708         __free_pages(page, 0);
 709         return NULL;
 710 }
 711
 712 static struct sk_buff *receive_small(struct net_device *dev,
 713                                      struct virtnet_info *vi,
 714                                      struct receive_queue *rq,
 715                                      void *buf, void *ctx,
 716                                      unsigned int len,
 717                                      unsigned int *xdp_xmit,
 718                                      struct virtnet_rq_stats *stats)
 719 {
 720         struct sk_buff *skb;
 721         struct bpf_prog *xdp_prog;
 722         unsigned int xdp_headroom = (unsigned long)ctx;
 723         unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
 724         unsigned int headroom = vi->hdr_len + header_offset;
 725         unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 726                               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 727         struct page *page = virt_to_head_page(buf);
 728         unsigned int delta = 0;
 729         struct page *xdp_page;
 730         int err;
 731         unsigned int metasize = 0;
 732
 733         len -= vi->hdr_len;
 734         stats->bytes += len;
 735
 736         if (unlikely(len > GOOD_PACKET_LEN)) {
 737                 pr_debug("%s: rx error: len %u exceeds max size %d\n",
 738                          dev->name, len, GOOD_PACKET_LEN);
 739                 dev->stats.rx_length_errors++;
 740                 goto err_len;
 741         }
 742         rcu_read_lock();
 743         xdp_prog = rcu_dereference(rq->xdp_prog);
 744         if (xdp_prog) {
 745                 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
 746                 struct xdp_frame *xdpf;
 747                 struct xdp_buff xdp;
 748                 void *orig_data;
 749                 u32 act;
 750
 751                 if (unlikely(hdr->hdr.gso_type))
 752                         goto err_xdp;
 753
 754                 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
 755                         int offset = buf - page_address(page) + header_offset;
 756                         unsigned int tlen = len + vi->hdr_len;
 757                         u16 num_buf = 1;
 758
 759                         xdp_headroom = virtnet_get_headroom(vi);
 760                         header_offset = VIRTNET_RX_PAD + xdp_headroom;
 761                         headroom = vi->hdr_len + header_offset;
 762                         buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 763                                  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 764                         xdp_page = xdp_linearize_page(rq, &num_buf, page,
 765                                                       offset, header_offset,
 766                                                       &tlen);
 767                         if (!xdp_page)
 768                                 goto err_xdp;
 769
 770                         buf = page_address(xdp_page);
 771                         put_page(page);
 772                         page = xdp_page;
 773                 }
 774
 775                 xdp_init_buff(&xdp, buflen, &rq->xdp_rxq);
 776                 xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
 777                                  xdp_headroom, len, true);
 778                 orig_data = xdp.data;
 779                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 780                 stats->xdp_packets++;
 781
 782                 switch (act) {
 783                 case XDP_PASS:
 784                         /* Recalculate length in case bpf program changed it */
 785                         delta = orig_data - xdp.data;
 786                         len = xdp.data_end - xdp.data;
 787                         metasize = xdp.data - xdp.data_meta;
 788                         break;
 789                 case XDP_TX:
 790                         stats->xdp_tx++;
 791                         xdpf = xdp_convert_buff_to_frame(&xdp);
 792                         if (unlikely(!xdpf))
 793                                 goto err_xdp;
 794                         err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 795                         if (unlikely(!err)) {
 796                                 xdp_return_frame_rx_napi(xdpf);
 797                         } else if (unlikely(err < 0)) {
 798                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 799                                 goto err_xdp;
 800                         }
 801                         *xdp_xmit |= VIRTIO_XDP_TX;
 802                         rcu_read_unlock();
 803                         goto xdp_xmit;
 804                 case XDP_REDIRECT:
 805                         stats->xdp_redirects++;
 806                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
 807                         if (err)
 808                                 goto err_xdp;
 809                         *xdp_xmit |= VIRTIO_XDP_REDIR;
 810                         rcu_read_unlock();
 811                         goto xdp_xmit;
 812                 default:
 813                         bpf_warn_invalid_xdp_action(act);
 814                         fallthrough;
 815                 case XDP_ABORTED:
 816                         trace_xdp_exception(vi->dev, xdp_prog, act);
 817                         goto err_xdp;
 818                 case XDP_DROP:
 819                         goto err_xdp;
 820                 }
 821         }
 822         rcu_read_unlock();
 823
 824         skb = build_skb(buf, buflen);
 825         if (!skb) {
 826                 put_page(page);
 827                 goto err;
 828         }
 829         skb_reserve(skb, headroom - delta);
 830         skb_put(skb, len);
 831         if (!xdp_prog) {
 832                 buf += header_offset;
 833                 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
 834         } /* keep zeroed vnet hdr since XDP is loaded */
 835
 836         if (metasize)
 837                 skb_metadata_set(skb, metasize);
 838
 839 err:
 840         return skb;
 841
 842 err_xdp:
 843         rcu_read_unlock();
 844         stats->xdp_drops++;
 845 err_len:
 846         stats->drops++;
 847         put_page(page);
 848 xdp_xmit:
 849         return NULL;
 850 }
 851
 852 static struct sk_buff *receive_big(struct net_device *dev,
 853                                    struct virtnet_info *vi,
 854                                    struct receive_queue *rq,
 855                                    void *buf,
 856                                    unsigned int len,
 857                                    struct virtnet_rq_stats *stats)
 858 {
 859         struct page *page = buf;
 860         struct sk_buff *skb =
 861                 page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0, 0);
 862
 863         stats->bytes += len - vi->hdr_len;
 864         if (unlikely(!skb))
 865                 goto err;
 866
 867         return skb;
 868
 869 err:
 870         stats->drops++;
 871         give_pages(rq, page);
 872         return NULL;
 873 }
 874
 875 static struct sk_buff *receive_mergeable(struct net_device *dev,
 876                                          struct virtnet_info *vi,
 877                                          struct receive_queue *rq,
 878                                          void *buf,
 879                                          void *ctx,
 880                                          unsigned int len,
 881                                          unsigned int *xdp_xmit,
 882                                          struct virtnet_rq_stats *stats)
 883 {
 884         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 885         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 886         struct page *page = virt_to_head_page(buf);
 887         int offset = buf - page_address(page);
 888         struct sk_buff *head_skb, *curr_skb;
 889         struct bpf_prog *xdp_prog;
 890         unsigned int truesize = mergeable_ctx_to_truesize(ctx);
 891         unsigned int headroom = mergeable_ctx_to_headroom(ctx);
 892         unsigned int metasize = 0;
 893         unsigned int frame_sz;
 894         int err;
 895
 896         head_skb = NULL;
 897         stats->bytes += len - vi->hdr_len;
 898
 899         if (unlikely(len > truesize)) {
 900                 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 901                          dev->name, len, (unsigned long)ctx);
 902                 dev->stats.rx_length_errors++;
 903                 goto err_skb;
 904         }
 905         rcu_read_lock();
 906         xdp_prog = rcu_dereference(rq->xdp_prog);
 907         if (xdp_prog) {
 908                 struct xdp_frame *xdpf;
 909                 struct page *xdp_page;
 910                 struct xdp_buff xdp;
 911                 void *data;
 912                 u32 act;
 913
 914                 /* Transient failure which in theory could occur if
 915                  * in-flight packets from before XDP was enabled reach
 916                  * the receive path after XDP is loaded.
 917                  */
 918                 if (unlikely(hdr->hdr.gso_type))
 919                         goto err_xdp;
 920
 921                 /* Buffers with headroom use PAGE_SIZE as alloc size,
 922                  * see add_recvbuf_mergeable() + get_mergeable_buf_len()
 923                  */
 924                 frame_sz = headroom ? PAGE_SIZE : truesize;
 925
 926                 /* This happens when rx buffer size is underestimated
 927                  * or headroom is not enough because of the buffer
 928                  * was refilled before XDP is set. This should only
 929                  * happen for the first several packets, so we don't
 930                  * care much about its performance.
 931                  */
 932                 if (unlikely(num_buf > 1 ||
 933                              headroom < virtnet_get_headroom(vi))) {
 934                         /* linearize data for XDP */
 935                         xdp_page = xdp_linearize_page(rq, &num_buf,
 936                                                       page, offset,
 937                                                       VIRTIO_XDP_HEADROOM,
 938                                                       &len);
 939                         frame_sz = PAGE_SIZE;
 940
 941                         if (!xdp_page)
 942                                 goto err_xdp;
 943                         offset = VIRTIO_XDP_HEADROOM;
 944                 } else {
 945                         xdp_page = page;
 946                 }
 947
 948                 /* Allow consuming headroom but reserve enough space to push
 949                  * the descriptor on if we get an XDP_TX return code.
 950                  */
 951                 data = page_address(xdp_page) + offset;
 952                 xdp_init_buff(&xdp, frame_sz - vi->hdr_len, &rq->xdp_rxq);
 953                 xdp_prepare_buff(&xdp, data - VIRTIO_XDP_HEADROOM + vi->hdr_len,
 954                                  VIRTIO_XDP_HEADROOM, len - vi->hdr_len, true);
 955
 956                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 957                 stats->xdp_packets++;
 958
 959                 switch (act) {
 960                 case XDP_PASS:
 961                         metasize = xdp.data - xdp.data_meta;
 962
 963                         /* recalculate offset to account for any header
 964                          * adjustments and minus the metasize to copy the
 965                          * metadata in page_to_skb(). Note other cases do not
 966                          * build an skb and avoid using offset
 967                          */
 968                         offset = xdp.data - page_address(xdp_page) -
 969                                  vi->hdr_len - metasize;
 970
 971                         /* recalculate len if xdp.data, xdp.data_end or
 972                          * xdp.data_meta were adjusted
 973                          */
 974                         len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
 975                         /* We can only create skb based on xdp_page. */
 976                         if (unlikely(xdp_page != page)) {
 977                                 rcu_read_unlock();
 978                                 put_page(page);
 979                                 head_skb = page_to_skb(vi, rq, xdp_page, offset,
 980                                                        len, PAGE_SIZE, false,
 981                                                        metasize, true);
 982                                 return head_skb;
 983                         }
 984                         break;
 985                 case XDP_TX:
 986                         stats->xdp_tx++;
 987                         xdpf = xdp_convert_buff_to_frame(&xdp);
 988                         if (unlikely(!xdpf))
 989                                 goto err_xdp;
 990                         err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 991                         if (unlikely(!err)) {
 992                                 xdp_return_frame_rx_napi(xdpf);
 993                         } else if (unlikely(err < 0)) {
 994                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 995                                 if (unlikely(xdp_page != page))
 996                                         put_page(xdp_page);
 997                                 goto err_xdp;
 998                         }
 999                         *xdp_xmit |= VIRTIO_XDP_TX;
1000                         if (unlikely(xdp_page != page))
1001                                 put_page(page);
1002                         rcu_read_unlock();
1003                         goto xdp_xmit;
1004                 case XDP_REDIRECT:
1005                         stats->xdp_redirects++;
1006                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
1007                         if (err) {
1008                                 if (unlikely(xdp_page != page))
1009                                         put_page(xdp_page);
1010                                 goto err_xdp;
1011                         }
1012                         *xdp_xmit |= VIRTIO_XDP_REDIR;
1013                         if (unlikely(xdp_page != page))
1014                                 put_page(page);
1015                         rcu_read_unlock();
1016                         goto xdp_xmit;
1017                 default:
1018                         bpf_warn_invalid_xdp_action(act);
1019                         fallthrough;
1020                 case XDP_ABORTED:
1021                         trace_xdp_exception(vi->dev, xdp_prog, act);
1022                         fallthrough;
1023                 case XDP_DROP:
1024                         if (unlikely(xdp_page != page))
1025                                 __free_pages(xdp_page, 0);
1026                         goto err_xdp;
1027                 }
1028         }
1029         rcu_read_unlock();
1030
1031         head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
1032                                metasize, !!headroom);
1033         curr_skb = head_skb;
1034
1035         if (unlikely(!curr_skb))
1036                 goto err_skb;
1037         while (--num_buf) {
1038                 int num_skb_frags;
1039
1040                 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
1041                 if (unlikely(!buf)) {
1042                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
1043                                  dev->name, num_buf,
1044                                  virtio16_to_cpu(vi->vdev,
1045                                                  hdr->num_buffers));
1046                         dev->stats.rx_length_errors++;
1047                         goto err_buf;
1048                 }
1049
1050                 stats->bytes += len;
1051                 page = virt_to_head_page(buf);
1052
1053                 truesize = mergeable_ctx_to_truesize(ctx);
1054                 if (unlikely(len > truesize)) {
1055                         pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
1056                                  dev->name, len, (unsigned long)ctx);
1057                         dev->stats.rx_length_errors++;
1058                         goto err_skb;
1059                 }
1060
1061                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
1062                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
1063                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
1064
1065                         if (unlikely(!nskb))
1066                                 goto err_skb;
1067                         if (curr_skb == head_skb)
1068                                 skb_shinfo(curr_skb)->frag_list = nskb;
1069                         else
1070                                 curr_skb->next = nskb;
1071                         curr_skb = nskb;
1072                         head_skb->truesize += nskb->truesize;
1073                         num_skb_frags = 0;
1074                 }
1075                 if (curr_skb != head_skb) {
1076                         head_skb->data_len += len;
1077                         head_skb->len += len;
1078                         head_skb->truesize += truesize;
1079                 }
1080                 offset = buf - page_address(page);
1081                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
1082                         put_page(page);
1083                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
1084                                              len, truesize);
1085                 } else {
1086                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
1087                                         offset, len, truesize);
1088                 }
1089         }
1090
1091         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
1092         return head_skb;
1093
1094 err_xdp:
1095         rcu_read_unlock();
1096         stats->xdp_drops++;
1097 err_skb:
1098         put_page(page);
1099         while (num_buf-- > 1) {
1100                 buf = virtqueue_get_buf(rq->vq, &len);
1101                 if (unlikely(!buf)) {
1102                         pr_debug("%s: rx error: %d buffers missing\n",
1103                                  dev->name, num_buf);
1104                         dev->stats.rx_length_errors++;
1105                         break;
1106                 }
1107                 stats->bytes += len;
1108                 page = virt_to_head_page(buf);
1109                 put_page(page);
1110         }
1111 err_buf:
1112         stats->drops++;
1113         dev_kfree_skb(head_skb);
1114 xdp_xmit:
1115         return NULL;
1116 }
1117
1118 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
1119                         void *buf, unsigned int len, void **ctx,
1120                         unsigned int *xdp_xmit,
1121                         struct virtnet_rq_stats *stats)
1122 {
1123         struct net_device *dev = vi->dev;
1124         struct sk_buff *skb;
1125         struct virtio_net_hdr_mrg_rxbuf *hdr;
1126
1127         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
1128                 pr_debug("%s: short packet %i\n", dev->name, len);
1129                 dev->stats.rx_length_errors++;
1130                 if (vi->mergeable_rx_bufs) {
1131                         put_page(virt_to_head_page(buf));
1132                 } else if (vi->big_packets) {
1133                         give_pages(rq, buf);
1134                 } else {
1135                         put_page(virt_to_head_page(buf));
1136                 }
1137                 return;
1138         }
1139
1140         if (vi->mergeable_rx_bufs)
1141                 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
1142                                         stats);
1143         else if (vi->big_packets)
1144                 skb = receive_big(dev, vi, rq, buf, len, stats);
1145         else
1146                 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
1147
1148         if (unlikely(!skb))
1149                 return;
1150
1151         hdr = skb_vnet_hdr(skb);
1152
1153         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
1154                 skb->ip_summed = CHECKSUM_UNNECESSARY;
1155
1156         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
1157                                   virtio_is_little_endian(vi->vdev))) {
1158                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
1159                                      dev->name, hdr->hdr.gso_type,
1160                                      hdr->hdr.gso_size);
1161                 goto frame_err;
1162         }
1163
1164         skb_record_rx_queue(skb, vq2rxq(rq->vq));
1165         skb->protocol = eth_type_trans(skb, dev);
1166         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
1167                  ntohs(skb->protocol), skb->len, skb->pkt_type);
1168
1169         napi_gro_receive(&rq->napi, skb);
1170         return;
1171
1172 frame_err:
1173         dev->stats.rx_frame_errors++;
1174         dev_kfree_skb(skb);
1175 }
1176
1177 /* Unlike mergeable buffers, all buffers are allocated to the
1178  * same size, except for the headroom. For this reason we do
1179  * not need to use  mergeable_len_to_ctx here - it is enough
1180  * to store the headroom as the context ignoring the truesize.
1181  */
1182 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
1183                              gfp_t gfp)
1184 {
1185         struct page_frag *alloc_frag = &rq->alloc_frag;
1186         char *buf;
1187         unsigned int xdp_headroom = virtnet_get_headroom(vi);
1188         void *ctx = (void *)(unsigned long)xdp_headroom;
1189         int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
1190         int err;
1191
1192         len = SKB_DATA_ALIGN(len) +
1193               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1194         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
1195                 return -ENOMEM;
1196
1197         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1198         get_page(alloc_frag->page);
1199         alloc_frag->offset += len;
1200         sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
1201                     vi->hdr_len + GOOD_PACKET_LEN);
1202         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1203         if (err < 0)
1204                 put_page(virt_to_head_page(buf));
1205         return err;
1206 }
1207
1208 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
1209                            gfp_t gfp)
1210 {
1211         struct page *first, *list = NULL;
1212         char *p;
1213         int i, err, offset;
1214
1215         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
1216
1217         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
1218         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
1219                 first = get_a_page(rq, gfp);
1220                 if (!first) {
1221                         if (list)
1222                                 give_pages(rq, list);
1223                         return -ENOMEM;
1224                 }
1225                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1226
1227                 /* chain new page in list head to match sg */
1228                 first->private = (unsigned long)list;
1229                 list = first;
1230         }
1231
1232         first = get_a_page(rq, gfp);
1233         if (!first) {
1234                 give_pages(rq, list);
1235                 return -ENOMEM;
1236         }
1237         p = page_address(first);
1238
1239         /* rq->sg[0], rq->sg[1] share the same page */
1240         /* a separated rq->sg[0] for header - required in case !any_header_sg */
1241         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1242
1243         /* rq->sg[1] for data packet, from offset */
1244         offset = sizeof(struct padded_vnet_hdr);
1245         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1246
1247         /* chain first in list head */
1248         first->private = (unsigned long)list;
1249         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
1250                                   first, gfp);
1251         if (err < 0)
1252                 give_pages(rq, first);
1253
1254         return err;
1255 }
1256
1257 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1258                                           struct ewma_pkt_len *avg_pkt_len,
1259                                           unsigned int room)
1260 {
1261         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1262         unsigned int len;
1263
1264         if (room)
1265                 return PAGE_SIZE - room;
1266
1267         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1268                                 rq->min_buf_len, PAGE_SIZE - hdr_len);
1269
1270         return ALIGN(len, L1_CACHE_BYTES);
1271 }
1272
1273 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1274                                  struct receive_queue *rq, gfp_t gfp)
1275 {
1276         struct page_frag *alloc_frag = &rq->alloc_frag;
1277         unsigned int headroom = virtnet_get_headroom(vi);
1278         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1279         unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1280         char *buf;
1281         void *ctx;
1282         int err;
1283         unsigned int len, hole;
1284
1285         /* Extra tailroom is needed to satisfy XDP's assumption. This
1286          * means rx frags coalescing won't work, but consider we've
1287          * disabled GSO for XDP, it won't be a big issue.
1288          */
1289         len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1290         if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1291                 return -ENOMEM;
1292
1293         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1294         buf += headroom; /* advance address leaving hole at front of pkt */
1295         get_page(alloc_frag->page);
1296         alloc_frag->offset += len + room;
1297         hole = alloc_frag->size - alloc_frag->offset;
1298         if (hole < len + room) {
1299                 /* To avoid internal fragmentation, if there is very likely not
1300                  * enough space for another buffer, add the remaining space to
1301                  * the current buffer.
1302                  */
1303                 len += hole;
1304                 alloc_frag->offset += hole;
1305         }
1306
1307         sg_init_one(rq->sg, buf, len);
1308         ctx = mergeable_len_to_ctx(len, headroom);
1309         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1310         if (err < 0)
1311                 put_page(virt_to_head_page(buf));
1312
1313         return err;
1314 }
1315
1316 /*
1317  * Returns false if we couldn't fill entirely (OOM).
1318  *
1319  * Normally run in the receive path, but can also be run from ndo_open
1320  * before we're receiving packets, or from refill_work which is
1321  * careful to disable receiving (using napi_disable).
1322  */
1323 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1324                           gfp_t gfp)
1325 {
1326         int err;
1327         bool oom;
1328
1329         do {
1330                 if (vi->mergeable_rx_bufs)
1331                         err = add_recvbuf_mergeable(vi, rq, gfp);
1332                 else if (vi->big_packets)
1333                         err = add_recvbuf_big(vi, rq, gfp);
1334                 else
1335                         err = add_recvbuf_small(vi, rq, gfp);
1336
1337                 oom = err == -ENOMEM;
1338                 if (err)
1339                         break;
1340         } while (rq->vq->num_free);
1341         if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
1342                 unsigned long flags;
1343
1344                 flags = u64_stats_update_begin_irqsave(&rq->stats.syncp);
1345                 rq->stats.kicks++;
1346                 u64_stats_update_end_irqrestore(&rq->stats.syncp, flags);
1347         }
1348
1349         return !oom;
1350 }
1351
1352 static void skb_recv_done(struct virtqueue *rvq)
1353 {
1354         struct virtnet_info *vi = rvq->vdev->priv;
1355         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1356
1357         virtqueue_napi_schedule(&rq->napi, rvq);
1358 }
1359
1360 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1361 {
1362         napi_enable(napi);
1363
1364         /* If all buffers were filled by other side before we napi_enabled, we
1365          * won't get another interrupt, so process any outstanding packets now.
1366          * Call local_bh_enable after to trigger softIRQ processing.
1367          */
1368         local_bh_disable();
1369         virtqueue_napi_schedule(napi, vq);
1370         local_bh_enable();
1371 }
1372
1373 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1374                                    struct virtqueue *vq,
1375                                    struct napi_struct *napi)
1376 {
1377         if (!napi->weight)
1378                 return;
1379
1380         /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1381          * enable the feature if this is likely affine with the transmit path.
1382          */
1383         if (!vi->affinity_hint_set) {
1384                 napi->weight = 0;
1385                 return;
1386         }
1387
1388         return virtnet_napi_enable(vq, napi);
1389 }
1390
1391 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1392 {
1393         if (napi->weight)
1394                 napi_disable(napi);
1395 }
1396
1397 static void refill_work(struct work_struct *work)
1398 {
1399         struct virtnet_info *vi =
1400                 container_of(work, struct virtnet_info, refill.work);
1401         bool still_empty;
1402         int i;
1403
1404         for (i = 0; i < vi->curr_queue_pairs; i++) {
1405                 struct receive_queue *rq = &vi->rq[i];
1406
1407                 napi_disable(&rq->napi);
1408                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1409                 virtnet_napi_enable(rq->vq, &rq->napi);
1410
1411                 /* In theory, this can happen: if we don't get any buffers in
1412                  * we will *never* try to fill again.
1413                  */
1414                 if (still_empty)
1415                         schedule_delayed_work(&vi->refill, HZ/2);
1416         }
1417 }
1418
1419 static int virtnet_receive(struct receive_queue *rq, int budget,
1420                            unsigned int *xdp_xmit)
1421 {
1422         struct virtnet_info *vi = rq->vq->vdev->priv;
1423         struct virtnet_rq_stats stats = {};
1424         unsigned int len;
1425         void *buf;
1426         int i;
1427
1428         if (!vi->big_packets || vi->mergeable_rx_bufs) {
1429                 void *ctx;
1430
1431                 while (stats.packets < budget &&
1432                        (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1433                         receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
1434                         stats.packets++;
1435                 }
1436         } else {
1437                 while (stats.packets < budget &&
1438                        (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1439                         receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
1440                         stats.packets++;
1441                 }
1442         }
1443
1444         if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
1445                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1446                         schedule_delayed_work(&vi->refill, 0);
1447         }
1448
1449         u64_stats_update_begin(&rq->stats.syncp);
1450         for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
1451                 size_t offset = virtnet_rq_stats_desc[i].offset;
1452                 u64 *item;
1453
1454                 item = (u64 *)((u8 *)&rq->stats + offset);
1455                 *item += *(u64 *)((u8 *)&stats + offset);
1456         }
1457         u64_stats_update_end(&rq->stats.syncp);
1458
1459         return stats.packets;
1460 }
1461
1462 static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
1463 {
1464         unsigned int len;
1465         unsigned int packets = 0;
1466         unsigned int bytes = 0;
1467         void *ptr;
1468
1469         while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1470                 if (likely(!is_xdp_frame(ptr))) {
1471                         struct sk_buff *skb = ptr;
1472
1473                         pr_debug("Sent skb %p\n", skb);
1474
1475                         bytes += skb->len;
1476                         napi_consume_skb(skb, in_napi);
1477                 } else {
1478                         struct xdp_frame *frame = ptr_to_xdp(ptr);
1479
1480                         bytes += frame->len;
1481                         xdp_return_frame(frame);
1482                 }
1483                 packets++;
1484         }
1485
1486         /* Avoid overhead when no packets have been processed
1487          * happens when called speculatively from start_xmit.
1488          */
1489         if (!packets)
1490                 return;
1491
1492         u64_stats_update_begin(&sq->stats.syncp);
1493         sq->stats.bytes += bytes;
1494         sq->stats.packets += packets;
1495         u64_stats_update_end(&sq->stats.syncp);
1496 }
1497
1498 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
1499 {
1500         if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
1501                 return false;
1502         else if (q < vi->curr_queue_pairs)
1503                 return true;
1504         else
1505                 return false;
1506 }
1507
1508 static void virtnet_poll_cleantx(struct receive_queue *rq)
1509 {
1510         struct virtnet_info *vi = rq->vq->vdev->priv;
1511         unsigned int index = vq2rxq(rq->vq);
1512         struct send_queue *sq = &vi->sq[index];
1513         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1514
1515         if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
1516                 return;
1517
1518         if (__netif_tx_trylock(txq)) {
1519                 do {
1520                         virtqueue_disable_cb(sq->vq);
1521                         free_old_xmit_skbs(sq, true);
1522                 } while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1523
1524                 if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1525                         netif_tx_wake_queue(txq);
1526
1527                 __netif_tx_unlock(txq);
1528         }
1529 }
1530
1531 static int virtnet_poll(struct napi_struct *napi, int budget)
1532 {
1533         struct receive_queue *rq =
1534                 container_of(napi, struct receive_queue, napi);
1535         struct virtnet_info *vi = rq->vq->vdev->priv;
1536         struct send_queue *sq;
1537         unsigned int received;
1538         unsigned int xdp_xmit = 0;
1539
1540         virtnet_poll_cleantx(rq);
1541
1542         received = virtnet_receive(rq, budget, &xdp_xmit);
1543
1544         /* Out of packets? */
1545         if (received < budget)
1546                 virtqueue_napi_complete(napi, rq->vq, received);
1547
1548         if (xdp_xmit & VIRTIO_XDP_REDIR)
1549                 xdp_do_flush();
1550
1551         if (xdp_xmit & VIRTIO_XDP_TX) {
1552                 sq = virtnet_xdp_get_sq(vi);
1553                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1554                         u64_stats_update_begin(&sq->stats.syncp);
1555                         sq->stats.kicks++;
1556                         u64_stats_update_end(&sq->stats.syncp);
1557                 }
1558                 virtnet_xdp_put_sq(vi, sq);
1559         }
1560
1561         return received;
1562 }
1563
1564 static int virtnet_open(struct net_device *dev)
1565 {
1566         struct virtnet_info *vi = netdev_priv(dev);
1567         int i, err;
1568
1569         for (i = 0; i < vi->max_queue_pairs; i++) {
1570                 if (i < vi->curr_queue_pairs)
1571                         /* Make sure we have some buffers: if oom use wq. */
1572                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1573                                 schedule_delayed_work(&vi->refill, 0);
1574
1575                 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
1576                 if (err < 0)
1577                         return err;
1578
1579                 err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
1580                                                  MEM_TYPE_PAGE_SHARED, NULL);
1581                 if (err < 0) {
1582                         xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1583                         return err;
1584                 }
1585
1586                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1587                 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1588         }
1589
1590         return 0;
1591 }
1592
1593 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1594 {
1595         struct send_queue *sq = container_of(napi, struct send_queue, napi);
1596         struct virtnet_info *vi = sq->vq->vdev->priv;
1597         unsigned int index = vq2txq(sq->vq);
1598         struct netdev_queue *txq;
1599         int opaque;
1600         bool done;
1601
1602         if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
1603                 /* We don't need to enable cb for XDP */
1604                 napi_complete_done(napi, 0);
1605                 return 0;
1606         }
1607
1608         txq = netdev_get_tx_queue(vi->dev, index);
1609         __netif_tx_lock(txq, raw_smp_processor_id());
1610         virtqueue_disable_cb(sq->vq);
1611         free_old_xmit_skbs(sq, true);
1612
1613         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1614                 netif_tx_wake_queue(txq);
1615
1616         opaque = virtqueue_enable_cb_prepare(sq->vq);
1617
1618         done = napi_complete_done(napi, 0);
1619
1620         if (!done)
1621                 virtqueue_disable_cb(sq->vq);
1622
1623         __netif_tx_unlock(txq);
1624
1625         if (done) {
1626                 if (unlikely(virtqueue_poll(sq->vq, opaque))) {
1627                         if (napi_schedule_prep(napi)) {
1628                                 __netif_tx_lock(txq, raw_smp_processor_id());
1629                                 virtqueue_disable_cb(sq->vq);
1630                                 __netif_tx_unlock(txq);
1631                                 __napi_schedule(napi);
1632                         }
1633                 }
1634         }
1635
1636         return 0;
1637 }
1638
1639 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1640 {
1641         struct virtio_net_hdr_mrg_rxbuf *hdr;
1642         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1643         struct virtnet_info *vi = sq->vq->vdev->priv;
1644         int num_sg;
1645         unsigned hdr_len = vi->hdr_len;
1646         bool can_push;
1647
1648         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1649
1650         can_push = vi->any_header_sg &&
1651                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1652                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1653         /* Even if we can, don't push here yet as this would skew
1654          * csum_start offset below. */
1655         if (can_push)
1656                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1657         else
1658                 hdr = skb_vnet_hdr(skb);
1659
1660         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1661                                     virtio_is_little_endian(vi->vdev), false,
1662                                     0))
1663                 return -EPROTO;
1664
1665         if (vi->mergeable_rx_bufs)
1666                 hdr->num_buffers = 0;
1667
1668         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1669         if (can_push) {
1670                 __skb_push(skb, hdr_len);
1671                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1672                 if (unlikely(num_sg < 0))
1673                         return num_sg;
1674                 /* Pull header back to avoid skew in tx bytes calculations. */
1675                 __skb_pull(skb, hdr_len);
1676         } else {
1677                 sg_set_buf(sq->sg, hdr, hdr_len);
1678                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1679                 if (unlikely(num_sg < 0))
1680                         return num_sg;
1681                 num_sg++;
1682         }
1683         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1684 }
1685
1686 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1687 {
1688         struct virtnet_info *vi = netdev_priv(dev);
1689         int qnum = skb_get_queue_mapping(skb);
1690         struct send_queue *sq = &vi->sq[qnum];
1691         int err;
1692         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1693         bool kick = !netdev_xmit_more();
1694         bool use_napi = sq->napi.weight;
1695
1696         /* Free up any pending old buffers before queueing new ones. */
1697         do {
1698                 if (use_napi)
1699                         virtqueue_disable_cb(sq->vq);
1700
1701                 free_old_xmit_skbs(sq, false);
1702
1703         } while (use_napi && kick &&
1704                unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
1705
1706         /* timestamp packet in software */
1707         skb_tx_timestamp(skb);
1708
1709         /* Try to transmit */
1710         err = xmit_skb(sq, skb);
1711
1712         /* This should not happen! */
1713         if (unlikely(err)) {
1714                 dev->stats.tx_fifo_errors++;
1715                 if (net_ratelimit())
1716                         dev_warn(&dev->dev,
1717                                  "Unexpected TXQ (%d) queue failure: %d\n",
1718                                  qnum, err);
1719                 dev->stats.tx_dropped++;
1720                 dev_kfree_skb_any(skb);
1721                 return NETDEV_TX_OK;
1722         }
1723
1724         /* Don't wait up for transmitted skbs to be freed. */
1725         if (!use_napi) {
1726                 skb_orphan(skb);
1727                 nf_reset_ct(skb);
1728         }
1729
1730         /* If running out of space, stop queue to avoid getting packets that we
1731          * are then unable to transmit.
1732          * An alternative would be to force queuing layer to requeue the skb by
1733          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1734          * returned in a normal path of operation: it means that driver is not
1735          * maintaining the TX queue stop/start state properly, and causes
1736          * the stack to do a non-trivial amount of useless work.
1737          * Since most packets only take 1 or 2 ring slots, stopping the queue
1738          * early means 16 slots are typically wasted.
1739          */
1740         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1741                 netif_stop_subqueue(dev, qnum);
1742                 if (!use_napi &&
1743                     unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1744                         /* More just got used, free them then recheck. */
1745                         free_old_xmit_skbs(sq, false);
1746                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1747                                 netif_start_subqueue(dev, qnum);
1748                                 virtqueue_disable_cb(sq->vq);
1749                         }
1750                 }
1751         }
1752
1753         if (kick || netif_xmit_stopped(txq)) {
1754                 if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
1755                         u64_stats_update_begin(&sq->stats.syncp);
1756                         sq->stats.kicks++;
1757                         u64_stats_update_end(&sq->stats.syncp);
1758                 }
1759         }
1760
1761         return NETDEV_TX_OK;
1762 }
1763
1764 /*
1765  * Send command via the control virtqueue and check status.  Commands
1766  * supported by the hypervisor, as indicated by feature bits, should
1767  * never fail unless improperly formatted.
1768  */
1769 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1770                                  struct scatterlist *out)
1771 {
1772         struct scatterlist *sgs[4], hdr, stat;
1773         unsigned out_num = 0, tmp;
1774         int ret;
1775
1776         /* Caller should know better */
1777         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1778
1779         vi->ctrl->status = ~0;
1780         vi->ctrl->hdr.class = class;
1781         vi->ctrl->hdr.cmd = cmd;
1782         /* Add header */
1783         sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1784         sgs[out_num++] = &hdr;
1785
1786         if (out)
1787                 sgs[out_num++] = out;
1788
1789         /* Add return status. */
1790         sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1791         sgs[out_num] = &stat;
1792
1793         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1794         ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1795         if (ret < 0) {
1796                 dev_warn(&vi->vdev->dev,
1797                          "Failed to add sgs for command vq: %d\n.", ret);
1798                 return false;
1799         }
1800
1801         if (unlikely(!virtqueue_kick(vi->cvq)))
1802                 return vi->ctrl->status == VIRTIO_NET_OK;
1803
1804         /* Spin for a response, the kick causes an ioport write, trapping
1805          * into the hypervisor, so the request should be handled immediately.
1806          */
1807         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1808                !virtqueue_is_broken(vi->cvq))
1809                 cpu_relax();
1810
1811         return vi->ctrl->status == VIRTIO_NET_OK;
1812 }
1813
1814 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1815 {
1816         struct virtnet_info *vi = netdev_priv(dev);
1817         struct virtio_device *vdev = vi->vdev;
1818         int ret;
1819         struct sockaddr *addr;
1820         struct scatterlist sg;
1821
1822         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
1823                 return -EOPNOTSUPP;
1824
1825         addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1826         if (!addr)
1827                 return -ENOMEM;
1828
1829         ret = eth_prepare_mac_addr_change(dev, addr);
1830         if (ret)
1831                 goto out;
1832
1833         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1834                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1835                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1836                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1837                         dev_warn(&vdev->dev,
1838                                  "Failed to set mac address by vq command.\n");
1839                         ret = -EINVAL;
1840                         goto out;
1841                 }
1842         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1843                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1844                 unsigned int i;
1845
1846                 /* Naturally, this has an atomicity problem. */
1847                 for (i = 0; i < dev->addr_len; i++)
1848                         virtio_cwrite8(vdev,
1849                                        offsetof(struct virtio_net_config, mac) +
1850                                        i, addr->sa_data[i]);
1851         }
1852
1853         eth_commit_mac_addr_change(dev, p);
1854         ret = 0;
1855
1856 out:
1857         kfree(addr);
1858         return ret;
1859 }
1860
1861 static void virtnet_stats(struct net_device *dev,
1862                           struct rtnl_link_stats64 *tot)
1863 {
1864         struct virtnet_info *vi = netdev_priv(dev);
1865         unsigned int start;
1866         int i;
1867
1868         for (i = 0; i < vi->max_queue_pairs; i++) {
1869                 u64 tpackets, tbytes, rpackets, rbytes, rdrops;
1870                 struct receive_queue *rq = &vi->rq[i];
1871                 struct send_queue *sq = &vi->sq[i];
1872
1873                 do {
1874                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1875                         tpackets = sq->stats.packets;
1876                         tbytes   = sq->stats.bytes;
1877                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1878
1879                 do {
1880                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1881                         rpackets = rq->stats.packets;
1882                         rbytes   = rq->stats.bytes;
1883                         rdrops   = rq->stats.drops;
1884                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1885
1886                 tot->rx_packets += rpackets;
1887                 tot->tx_packets += tpackets;
1888                 tot->rx_bytes   += rbytes;
1889                 tot->tx_bytes   += tbytes;
1890                 tot->rx_dropped += rdrops;
1891         }
1892
1893         tot->tx_dropped = dev->stats.tx_dropped;
1894         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1895         tot->rx_length_errors = dev->stats.rx_length_errors;
1896         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1897 }
1898
1899 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1900 {
1901         rtnl_lock();
1902         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1903                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1904                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1905         rtnl_unlock();
1906 }
1907
1908 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1909 {
1910         struct scatterlist sg;
1911         struct net_device *dev = vi->dev;
1912
1913         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1914                 return 0;
1915
1916         vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1917         sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
1918
1919         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1920                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1921                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1922                          queue_pairs);
1923                 return -EINVAL;
1924         } else {
1925                 vi->curr_queue_pairs = queue_pairs;
1926                 /* virtnet_open() will refill when device is going to up. */
1927                 if (dev->flags & IFF_UP)
1928                         schedule_delayed_work(&vi->refill, 0);
1929         }
1930
1931         return 0;
1932 }
1933
1934 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1935 {
1936         int err;
1937
1938         rtnl_lock();
1939         err = _virtnet_set_queues(vi, queue_pairs);
1940         rtnl_unlock();
1941         return err;
1942 }
1943
1944 static int virtnet_close(struct net_device *dev)
1945 {
1946         struct virtnet_info *vi = netdev_priv(dev);
1947         int i;
1948
1949         /* Make sure refill_work doesn't re-enable napi! */
1950         cancel_delayed_work_sync(&vi->refill);
1951
1952         for (i = 0; i < vi->max_queue_pairs; i++) {
1953                 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1954                 napi_disable(&vi->rq[i].napi);
1955                 virtnet_napi_tx_disable(&vi->sq[i].napi);
1956         }
1957
1958         return 0;
1959 }
1960
1961 static void virtnet_set_rx_mode(struct net_device *dev)
1962 {
1963         struct virtnet_info *vi = netdev_priv(dev);
1964         struct scatterlist sg[2];
1965         struct virtio_net_ctrl_mac *mac_data;
1966         struct netdev_hw_addr *ha;
1967         int uc_count;
1968         int mc_count;
1969         void *buf;
1970         int i;
1971
1972         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1973         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1974                 return;
1975
1976         vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
1977         vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1978
1979         sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
1980
1981         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1982                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1983                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1984                          vi->ctrl->promisc ? "en" : "dis");
1985
1986         sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
1987
1988         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1989                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1990                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1991                          vi->ctrl->allmulti ? "en" : "dis");
1992
1993         uc_count = netdev_uc_count(dev);
1994         mc_count = netdev_mc_count(dev);
1995         /* MAC filter - use one buffer for both lists */
1996         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1997                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1998         mac_data = buf;
1999         if (!buf)
2000                 return;
2001
2002         sg_init_table(sg, 2);
2003
2004         /* Store the unicast list and count in the front of the buffer */
2005         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
2006         i = 0;
2007         netdev_for_each_uc_addr(ha, dev)
2008                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2009
2010         sg_set_buf(&sg[0], mac_data,
2011                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
2012
2013         /* multicast list and count fill the end */
2014         mac_data = (void *)&mac_data->macs[uc_count][0];
2015
2016         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
2017         i = 0;
2018         netdev_for_each_mc_addr(ha, dev)
2019                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
2020
2021         sg_set_buf(&sg[1], mac_data,
2022                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
2023
2024         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
2025                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
2026                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
2027
2028         kfree(buf);
2029 }
2030
2031 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
2032                                    __be16 proto, u16 vid)
2033 {
2034         struct virtnet_info *vi = netdev_priv(dev);
2035         struct scatterlist sg;
2036
2037         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2038         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2039
2040         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2041                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
2042                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
2043         return 0;
2044 }
2045
2046 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
2047                                     __be16 proto, u16 vid)
2048 {
2049         struct virtnet_info *vi = netdev_priv(dev);
2050         struct scatterlist sg;
2051
2052         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
2053         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
2054
2055         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
2056                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
2057                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
2058         return 0;
2059 }
2060
2061 static void virtnet_clean_affinity(struct virtnet_info *vi)
2062 {
2063         int i;
2064
2065         if (vi->affinity_hint_set) {
2066                 for (i = 0; i < vi->max_queue_pairs; i++) {
2067                         virtqueue_set_affinity(vi->rq[i].vq, NULL);
2068                         virtqueue_set_affinity(vi->sq[i].vq, NULL);
2069                 }
2070
2071                 vi->affinity_hint_set = false;
2072         }
2073 }
2074
2075 static void virtnet_set_affinity(struct virtnet_info *vi)
2076 {
2077         cpumask_var_t mask;
2078         int stragglers;
2079         int group_size;
2080         int i, j, cpu;
2081         int num_cpu;
2082         int stride;
2083
2084         if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
2085                 virtnet_clean_affinity(vi);
2086                 return;
2087         }
2088
2089         num_cpu = num_online_cpus();
2090         stride = max_t(int, num_cpu / vi->curr_queue_pairs, 1);
2091         stragglers = num_cpu >= vi->curr_queue_pairs ?
2092                         num_cpu % vi->curr_queue_pairs :
2093                         0;
2094         cpu = cpumask_next(-1, cpu_online_mask);
2095
2096         for (i = 0; i < vi->curr_queue_pairs; i++) {
2097                 group_size = stride + (i < stragglers ? 1 : 0);
2098
2099                 for (j = 0; j < group_size; j++) {
2100                         cpumask_set_cpu(cpu, mask);
2101                         cpu = cpumask_next_wrap(cpu, cpu_online_mask,
2102                                                 nr_cpu_ids, false);
2103                 }
2104                 virtqueue_set_affinity(vi->rq[i].vq, mask);
2105                 virtqueue_set_affinity(vi->sq[i].vq, mask);
2106                 __netif_set_xps_queue(vi->dev, cpumask_bits(mask), i, XPS_CPUS);
2107                 cpumask_clear(mask);
2108         }
2109
2110         vi->affinity_hint_set = true;
2111         free_cpumask_var(mask);
2112 }
2113
2114 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
2115 {
2116         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2117                                                    node);
2118         virtnet_set_affinity(vi);
2119         return 0;
2120 }
2121
2122 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
2123 {
2124         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2125                                                    node_dead);
2126         virtnet_set_affinity(vi);
2127         return 0;
2128 }
2129
2130 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
2131 {
2132         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
2133                                                    node);
2134
2135         virtnet_clean_affinity(vi);
2136         return 0;
2137 }
2138
2139 static enum cpuhp_state virtionet_online;
2140
2141 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
2142 {
2143         int ret;
2144
2145         ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
2146         if (ret)
2147                 return ret;
2148         ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2149                                                &vi->node_dead);
2150         if (!ret)
2151                 return ret;
2152         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2153         return ret;
2154 }
2155
2156 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
2157 {
2158         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
2159         cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
2160                                             &vi->node_dead);
2161 }
2162
2163 static void virtnet_get_ringparam(struct net_device *dev,
2164                                 struct ethtool_ringparam *ring)
2165 {
2166         struct virtnet_info *vi = netdev_priv(dev);
2167
2168         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
2169         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
2170         ring->rx_pending = ring->rx_max_pending;
2171         ring->tx_pending = ring->tx_max_pending;
2172 }
2173
2174
2175 static void virtnet_get_drvinfo(struct net_device *dev,
2176                                 struct ethtool_drvinfo *info)
2177 {
2178         struct virtnet_info *vi = netdev_priv(dev);
2179         struct virtio_device *vdev = vi->vdev;
2180
2181         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
2182         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
2183         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
2184
2185 }
2186
2187 /* TODO: Eliminate OOO packets during switching */
2188 static int virtnet_set_channels(struct net_device *dev,
2189                                 struct ethtool_channels *channels)
2190 {
2191         struct virtnet_info *vi = netdev_priv(dev);
2192         u16 queue_pairs = channels->combined_count;
2193         int err;
2194
2195         /* We don't support separate rx/tx channels.
2196          * We don't allow setting 'other' channels.
2197          */
2198         if (channels->rx_count || channels->tx_count || channels->other_count)
2199                 return -EINVAL;
2200
2201         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
2202                 return -EINVAL;
2203
2204         /* For now we don't support modifying channels while XDP is loaded
2205          * also when XDP is loaded all RX queues have XDP programs so we only
2206          * need to check a single RX queue.
2207          */
2208         if (vi->rq[0].xdp_prog)
2209                 return -EINVAL;
2210
2211         get_online_cpus();
2212         err = _virtnet_set_queues(vi, queue_pairs);
2213         if (err) {
2214                 put_online_cpus();
2215                 goto err;
2216         }
2217         virtnet_set_affinity(vi);
2218         put_online_cpus();
2219
2220         netif_set_real_num_tx_queues(dev, queue_pairs);
2221         netif_set_real_num_rx_queues(dev, queue_pairs);
2222  err:
2223         return err;
2224 }
2225
2226 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
2227 {
2228         struct virtnet_info *vi = netdev_priv(dev);
2229         unsigned int i, j;
2230         u8 *p = data;
2231
2232         switch (stringset) {
2233         case ETH_SS_STATS:
2234                 for (i = 0; i < vi->curr_queue_pairs; i++) {
2235                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++)
2236                                 ethtool_sprintf(&p, "rx_queue_%u_%s", i,
2237                                                 virtnet_rq_stats_desc[j].desc);
2238                 }
2239
2240                 for (i = 0; i < vi->curr_queue_pairs; i++) {
2241                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++)
2242                                 ethtool_sprintf(&p, "tx_queue_%u_%s", i,
2243                                                 virtnet_sq_stats_desc[j].desc);
2244                 }
2245                 break;
2246         }
2247 }
2248
2249 static int virtnet_get_sset_count(struct net_device *dev, int sset)
2250 {
2251         struct virtnet_info *vi = netdev_priv(dev);
2252
2253         switch (sset) {
2254         case ETH_SS_STATS:
2255                 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
2256                                                VIRTNET_SQ_STATS_LEN);
2257         default:
2258                 return -EOPNOTSUPP;
2259         }
2260 }
2261
2262 static void virtnet_get_ethtool_stats(struct net_device *dev,
2263                                       struct ethtool_stats *stats, u64 *data)
2264 {
2265         struct virtnet_info *vi = netdev_priv(dev);
2266         unsigned int idx = 0, start, i, j;
2267         const u8 *stats_base;
2268         size_t offset;
2269
2270         for (i = 0; i < vi->curr_queue_pairs; i++) {
2271                 struct receive_queue *rq = &vi->rq[i];
2272
2273                 stats_base = (u8 *)&rq->stats;
2274                 do {
2275                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
2276                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
2277                                 offset = virtnet_rq_stats_desc[j].offset;
2278                                 data[idx + j] = *(u64 *)(stats_base + offset);
2279                         }
2280                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
2281                 idx += VIRTNET_RQ_STATS_LEN;
2282         }
2283
2284         for (i = 0; i < vi->curr_queue_pairs; i++) {
2285                 struct send_queue *sq = &vi->sq[i];
2286
2287                 stats_base = (u8 *)&sq->stats;
2288                 do {
2289                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
2290                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
2291                                 offset = virtnet_sq_stats_desc[j].offset;
2292                                 data[idx + j] = *(u64 *)(stats_base + offset);
2293                         }
2294                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
2295                 idx += VIRTNET_SQ_STATS_LEN;
2296         }
2297 }
2298
2299 static void virtnet_get_channels(struct net_device *dev,
2300                                  struct ethtool_channels *channels)
2301 {
2302         struct virtnet_info *vi = netdev_priv(dev);
2303
2304         channels->combined_count = vi->curr_queue_pairs;
2305         channels->max_combined = vi->max_queue_pairs;
2306         channels->max_other = 0;
2307         channels->rx_count = 0;
2308         channels->tx_count = 0;
2309         channels->other_count = 0;
2310 }
2311
2312 static int virtnet_set_link_ksettings(struct net_device *dev,
2313                                       const struct ethtool_link_ksettings *cmd)
2314 {
2315         struct virtnet_info *vi = netdev_priv(dev);
2316
2317         return ethtool_virtdev_set_link_ksettings(dev, cmd,
2318                                                   &vi->speed, &vi->duplex);
2319 }
2320
2321 static int virtnet_get_link_ksettings(struct net_device *dev,
2322                                       struct ethtool_link_ksettings *cmd)
2323 {
2324         struct virtnet_info *vi = netdev_priv(dev);
2325
2326         cmd->base.speed = vi->speed;
2327         cmd->base.duplex = vi->duplex;
2328         cmd->base.port = PORT_OTHER;
2329
2330         return 0;
2331 }
2332
2333 static int virtnet_set_coalesce(struct net_device *dev,
2334                                 struct ethtool_coalesce *ec)
2335 {
2336         struct virtnet_info *vi = netdev_priv(dev);
2337         int i, napi_weight;
2338
2339         if (ec->tx_max_coalesced_frames > 1 ||
2340             ec->rx_max_coalesced_frames != 1)
2341                 return -EINVAL;
2342
2343         napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
2344         if (napi_weight ^ vi->sq[0].napi.weight) {
2345                 if (dev->flags & IFF_UP)
2346                         return -EBUSY;
2347                 for (i = 0; i < vi->max_queue_pairs; i++)
2348                         vi->sq[i].napi.weight = napi_weight;
2349         }
2350
2351         return 0;
2352 }
2353
2354 static int virtnet_get_coalesce(struct net_device *dev,
2355                                 struct ethtool_coalesce *ec)
2356 {
2357         struct ethtool_coalesce ec_default = {
2358                 .cmd = ETHTOOL_GCOALESCE,
2359                 .rx_max_coalesced_frames = 1,
2360         };
2361         struct virtnet_info *vi = netdev_priv(dev);
2362
2363         memcpy(ec, &ec_default, sizeof(ec_default));
2364
2365         if (vi->sq[0].napi.weight)
2366                 ec->tx_max_coalesced_frames = 1;
2367
2368         return 0;
2369 }
2370
2371 static void virtnet_init_settings(struct net_device *dev)
2372 {
2373         struct virtnet_info *vi = netdev_priv(dev);
2374
2375         vi->speed = SPEED_UNKNOWN;
2376         vi->duplex = DUPLEX_UNKNOWN;
2377 }
2378
2379 static void virtnet_update_settings(struct virtnet_info *vi)
2380 {
2381         u32 speed;
2382         u8 duplex;
2383
2384         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2385                 return;
2386
2387         virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
2388
2389         if (ethtool_validate_speed(speed))
2390                 vi->speed = speed;
2391
2392         virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
2393
2394         if (ethtool_validate_duplex(duplex))
2395                 vi->duplex = duplex;
2396 }
2397
2398 static const struct ethtool_ops virtnet_ethtool_ops = {
2399         .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES,
2400         .get_drvinfo = virtnet_get_drvinfo,
2401         .get_link = ethtool_op_get_link,
2402         .get_ringparam = virtnet_get_ringparam,
2403         .get_strings = virtnet_get_strings,
2404         .get_sset_count = virtnet_get_sset_count,
2405         .get_ethtool_stats = virtnet_get_ethtool_stats,
2406         .set_channels = virtnet_set_channels,
2407         .get_channels = virtnet_get_channels,
2408         .get_ts_info = ethtool_op_get_ts_info,
2409         .get_link_ksettings = virtnet_get_link_ksettings,
2410         .set_link_ksettings = virtnet_set_link_ksettings,
2411         .set_coalesce = virtnet_set_coalesce,
2412         .get_coalesce = virtnet_get_coalesce,
2413 };
2414
2415 static void virtnet_freeze_down(struct virtio_device *vdev)
2416 {
2417         struct virtnet_info *vi = vdev->priv;
2418         int i;
2419
2420         /* Make sure no work handler is accessing the device */
2421         flush_work(&vi->config_work);
2422
2423         netif_tx_lock_bh(vi->dev);
2424         netif_device_detach(vi->dev);
2425         netif_tx_unlock_bh(vi->dev);
2426         cancel_delayed_work_sync(&vi->refill);
2427
2428         if (netif_running(vi->dev)) {
2429                 for (i = 0; i < vi->max_queue_pairs; i++) {
2430                         napi_disable(&vi->rq[i].napi);
2431                         virtnet_napi_tx_disable(&vi->sq[i].napi);
2432                 }
2433         }
2434 }
2435
2436 static int init_vqs(struct virtnet_info *vi);
2437
2438 static int virtnet_restore_up(struct virtio_device *vdev)
2439 {
2440         struct virtnet_info *vi = vdev->priv;
2441         int err, i;
2442
2443         err = init_vqs(vi);
2444         if (err)
2445                 return err;
2446
2447         virtio_device_ready(vdev);
2448
2449         if (netif_running(vi->dev)) {
2450                 for (i = 0; i < vi->curr_queue_pairs; i++)
2451                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2452                                 schedule_delayed_work(&vi->refill, 0);
2453
2454                 for (i = 0; i < vi->max_queue_pairs; i++) {
2455                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2456                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2457                                                &vi->sq[i].napi);
2458                 }
2459         }
2460
2461         netif_tx_lock_bh(vi->dev);
2462         netif_device_attach(vi->dev);
2463         netif_tx_unlock_bh(vi->dev);
2464         return err;
2465 }
2466
2467 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2468 {
2469         struct scatterlist sg;
2470         vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
2471
2472         sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
2473
2474         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2475                                   VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2476                 dev_warn(&vi->dev->dev, "Fail to set guest offload.\n");
2477                 return -EINVAL;
2478         }
2479
2480         return 0;
2481 }
2482
2483 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2484 {
2485         u64 offloads = 0;
2486
2487         if (!vi->guest_offloads)
2488                 return 0;
2489
2490         return virtnet_set_guest_offloads(vi, offloads);
2491 }
2492
2493 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2494 {
2495         u64 offloads = vi->guest_offloads;
2496
2497         if (!vi->guest_offloads)
2498                 return 0;
2499
2500         return virtnet_set_guest_offloads(vi, offloads);
2501 }
2502
2503 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2504                            struct netlink_ext_ack *extack)
2505 {
2506         unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2507         struct virtnet_info *vi = netdev_priv(dev);
2508         struct bpf_prog *old_prog;
2509         u16 xdp_qp = 0, curr_qp;
2510         int i, err;
2511
2512         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2513             && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2514                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2515                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2516                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
2517                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
2518                 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
2519                 return -EOPNOTSUPP;
2520         }
2521
2522         if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2523                 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2524                 return -EINVAL;
2525         }
2526
2527         if (dev->mtu > max_sz) {
2528                 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2529                 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2530                 return -EINVAL;
2531         }
2532
2533         curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2534         if (prog)
2535                 xdp_qp = nr_cpu_ids;
2536
2537         /* XDP requires extra queues for XDP_TX */
2538         if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2539                 netdev_warn(dev, "XDP request %i queues but max is %i. XDP_TX and XDP_REDIRECT will operate in a slower locked tx mode.\n",
2540                             curr_qp + xdp_qp, vi->max_queue_pairs);
2541                 xdp_qp = 0;
2542         }
2543
2544         old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
2545         if (!prog && !old_prog)
2546                 return 0;
2547
2548         if (prog)
2549                 bpf_prog_add(prog, vi->max_queue_pairs - 1);
2550
2551         /* Make sure NAPI is not using any XDP TX queues for RX. */
2552         if (netif_running(dev)) {
2553                 for (i = 0; i < vi->max_queue_pairs; i++) {
2554                         napi_disable(&vi->rq[i].napi);
2555                         virtnet_napi_tx_disable(&vi->sq[i].napi);
2556                 }
2557         }
2558
2559         if (!prog) {
2560                 for (i = 0; i < vi->max_queue_pairs; i++) {
2561                         rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2562                         if (i == 0)
2563                                 virtnet_restore_guest_offloads(vi);
2564                 }
2565                 synchronize_net();
2566         }
2567
2568         err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2569         if (err)
2570                 goto err;
2571         netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2572         vi->xdp_queue_pairs = xdp_qp;
2573
2574         if (prog) {
2575                 vi->xdp_enabled = true;
2576                 for (i = 0; i < vi->max_queue_pairs; i++) {
2577                         rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2578                         if (i == 0 && !old_prog)
2579                                 virtnet_clear_guest_offloads(vi);
2580                 }
2581         } else {
2582                 vi->xdp_enabled = false;
2583         }
2584
2585         for (i = 0; i < vi->max_queue_pairs; i++) {
2586                 if (old_prog)
2587                         bpf_prog_put(old_prog);
2588                 if (netif_running(dev)) {
2589                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2590                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2591                                                &vi->sq[i].napi);
2592                 }
2593         }
2594
2595         return 0;
2596
2597 err:
2598         if (!prog) {
2599                 virtnet_clear_guest_offloads(vi);
2600                 for (i = 0; i < vi->max_queue_pairs; i++)
2601                         rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
2602         }
2603
2604         if (netif_running(dev)) {
2605                 for (i = 0; i < vi->max_queue_pairs; i++) {
2606                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2607                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2608                                                &vi->sq[i].napi);
2609                 }
2610         }
2611         if (prog)
2612                 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2613         return err;
2614 }
2615
2616 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2617 {
2618         switch (xdp->command) {
2619         case XDP_SETUP_PROG:
2620                 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2621         default:
2622                 return -EINVAL;
2623         }
2624 }
2625
2626 static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
2627                                       size_t len)
2628 {
2629         struct virtnet_info *vi = netdev_priv(dev);
2630         int ret;
2631
2632         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
2633                 return -EOPNOTSUPP;
2634
2635         ret = snprintf(buf, len, "sby");
2636         if (ret >= len)
2637                 return -EOPNOTSUPP;
2638
2639         return 0;
2640 }
2641
2642 static int virtnet_set_features(struct net_device *dev,
2643                                 netdev_features_t features)
2644 {
2645         struct virtnet_info *vi = netdev_priv(dev);
2646         u64 offloads;
2647         int err;
2648
2649         if ((dev->features ^ features) & NETIF_F_GRO_HW) {
2650                 if (vi->xdp_enabled)
2651                         return -EBUSY;
2652
2653                 if (features & NETIF_F_GRO_HW)
2654                         offloads = vi->guest_offloads_capable;
2655                 else
2656                         offloads = vi->guest_offloads_capable &
2657                                    ~GUEST_OFFLOAD_GRO_HW_MASK;
2658
2659                 err = virtnet_set_guest_offloads(vi, offloads);
2660                 if (err)
2661                         return err;
2662                 vi->guest_offloads = offloads;
2663         }
2664
2665         return 0;
2666 }
2667
2668 static const struct net_device_ops virtnet_netdev = {
2669         .ndo_open            = virtnet_open,
2670         .ndo_stop            = virtnet_close,
2671         .ndo_start_xmit      = start_xmit,
2672         .ndo_validate_addr   = eth_validate_addr,
2673         .ndo_set_mac_address = virtnet_set_mac_address,
2674         .ndo_set_rx_mode     = virtnet_set_rx_mode,
2675         .ndo_get_stats64     = virtnet_stats,
2676         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2677         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2678         .ndo_bpf                = virtnet_xdp,
2679         .ndo_xdp_xmit           = virtnet_xdp_xmit,
2680         .ndo_features_check     = passthru_features_check,
2681         .ndo_get_phys_port_name = virtnet_get_phys_port_name,
2682         .ndo_set_features       = virtnet_set_features,
2683 };
2684
2685 static void virtnet_config_changed_work(struct work_struct *work)
2686 {
2687         struct virtnet_info *vi =
2688                 container_of(work, struct virtnet_info, config_work);
2689         u16 v;
2690
2691         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2692                                  struct virtio_net_config, status, &v) < 0)
2693                 return;
2694
2695         if (v & VIRTIO_NET_S_ANNOUNCE) {
2696                 netdev_notify_peers(vi->dev);
2697                 virtnet_ack_link_announce(vi);
2698         }
2699
2700         /* Ignore unknown (future) status bits */
2701         v &= VIRTIO_NET_S_LINK_UP;
2702
2703         if (vi->status == v)
2704                 return;
2705
2706         vi->status = v;
2707
2708         if (vi->status & VIRTIO_NET_S_LINK_UP) {
2709                 virtnet_update_settings(vi);
2710                 netif_carrier_on(vi->dev);
2711                 netif_tx_wake_all_queues(vi->dev);
2712         } else {
2713                 netif_carrier_off(vi->dev);
2714                 netif_tx_stop_all_queues(vi->dev);
2715         }
2716 }
2717
2718 static void virtnet_config_changed(struct virtio_device *vdev)
2719 {
2720         struct virtnet_info *vi = vdev->priv;
2721
2722         schedule_work(&vi->config_work);
2723 }
2724
2725 static void virtnet_free_queues(struct virtnet_info *vi)
2726 {
2727         int i;
2728
2729         for (i = 0; i < vi->max_queue_pairs; i++) {
2730                 __netif_napi_del(&vi->rq[i].napi);
2731                 __netif_napi_del(&vi->sq[i].napi);
2732         }
2733
2734         /* We called __netif_napi_del(),
2735          * we need to respect an RCU grace period before freeing vi->rq
2736          */
2737         synchronize_net();
2738
2739         kfree(vi->rq);
2740         kfree(vi->sq);
2741         kfree(vi->ctrl);
2742 }
2743
2744 static void _free_receive_bufs(struct virtnet_info *vi)
2745 {
2746         struct bpf_prog *old_prog;
2747         int i;
2748
2749         for (i = 0; i < vi->max_queue_pairs; i++) {
2750                 while (vi->rq[i].pages)
2751                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2752
2753                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2754                 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2755                 if (old_prog)
2756                         bpf_prog_put(old_prog);
2757         }
2758 }
2759
2760 static void free_receive_bufs(struct virtnet_info *vi)
2761 {
2762         rtnl_lock();
2763         _free_receive_bufs(vi);
2764         rtnl_unlock();
2765 }
2766
2767 static void free_receive_page_frags(struct virtnet_info *vi)
2768 {
2769         int i;
2770         for (i = 0; i < vi->max_queue_pairs; i++)
2771                 if (vi->rq[i].alloc_frag.page)
2772                         put_page(vi->rq[i].alloc_frag.page);
2773 }
2774
2775 static void free_unused_bufs(struct virtnet_info *vi)
2776 {
2777         void *buf;
2778         int i;
2779
2780         for (i = 0; i < vi->max_queue_pairs; i++) {
2781                 struct virtqueue *vq = vi->sq[i].vq;
2782                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2783                         if (!is_xdp_frame(buf))
2784                                 dev_kfree_skb(buf);
2785                         else
2786                                 xdp_return_frame(ptr_to_xdp(buf));
2787                 }
2788         }
2789
2790         for (i = 0; i < vi->max_queue_pairs; i++) {
2791                 struct virtqueue *vq = vi->rq[i].vq;
2792
2793                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2794                         if (vi->mergeable_rx_bufs) {
2795                                 put_page(virt_to_head_page(buf));
2796                         } else if (vi->big_packets) {
2797                                 give_pages(&vi->rq[i], buf);
2798                         } else {
2799                                 put_page(virt_to_head_page(buf));
2800                         }
2801                 }
2802         }
2803 }
2804
2805 static void virtnet_del_vqs(struct virtnet_info *vi)
2806 {
2807         struct virtio_device *vdev = vi->vdev;
2808
2809         virtnet_clean_affinity(vi);
2810
2811         vdev->config->del_vqs(vdev);
2812
2813         virtnet_free_queues(vi);
2814 }
2815
2816 /* How large should a single buffer be so a queue full of these can fit at
2817  * least one full packet?
2818  * Logic below assumes the mergeable buffer header is used.
2819  */
2820 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2821 {
2822         const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2823         unsigned int rq_size = virtqueue_get_vring_size(vq);
2824         unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2825         unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2826         unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2827
2828         return max(max(min_buf_len, hdr_len) - hdr_len,
2829                    (unsigned int)GOOD_PACKET_LEN);
2830 }
2831
2832 static int virtnet_find_vqs(struct virtnet_info *vi)
2833 {
2834         vq_callback_t **callbacks;
2835         struct virtqueue **vqs;
2836         int ret = -ENOMEM;
2837         int i, total_vqs;
2838         const char **names;
2839         bool *ctx;
2840
2841         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2842          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2843          * possible control vq.
2844          */
2845         total_vqs = vi->max_queue_pairs * 2 +
2846                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2847
2848         /* Allocate space for find_vqs parameters */
2849         vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
2850         if (!vqs)
2851                 goto err_vq;
2852         callbacks = kmalloc_array(total_vqs, sizeof(*callbacks), GFP_KERNEL);
2853         if (!callbacks)
2854                 goto err_callback;
2855         names = kmalloc_array(total_vqs, sizeof(*names), GFP_KERNEL);
2856         if (!names)
2857                 goto err_names;
2858         if (!vi->big_packets || vi->mergeable_rx_bufs) {
2859                 ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
2860                 if (!ctx)
2861                         goto err_ctx;
2862         } else {
2863                 ctx = NULL;
2864         }
2865
2866         /* Parameters for control virtqueue, if any */
2867         if (vi->has_cvq) {
2868                 callbacks[total_vqs - 1] = NULL;
2869                 names[total_vqs - 1] = "control";
2870         }
2871
2872         /* Allocate/initialize parameters for send/receive virtqueues */
2873         for (i = 0; i < vi->max_queue_pairs; i++) {
2874                 callbacks[rxq2vq(i)] = skb_recv_done;
2875                 callbacks[txq2vq(i)] = skb_xmit_done;
2876                 sprintf(vi->rq[i].name, "input.%d", i);
2877                 sprintf(vi->sq[i].name, "output.%d", i);
2878                 names[rxq2vq(i)] = vi->rq[i].name;
2879                 names[txq2vq(i)] = vi->sq[i].name;
2880                 if (ctx)
2881                         ctx[rxq2vq(i)] = true;
2882         }
2883
2884         ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
2885                                   names, ctx, NULL);
2886         if (ret)
2887                 goto err_find;
2888
2889         if (vi->has_cvq) {
2890                 vi->cvq = vqs[total_vqs - 1];
2891                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2892                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2893         }
2894
2895         for (i = 0; i < vi->max_queue_pairs; i++) {
2896                 vi->rq[i].vq = vqs[rxq2vq(i)];
2897                 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2898                 vi->sq[i].vq = vqs[txq2vq(i)];
2899         }
2900
2901         /* run here: ret == 0. */
2902
2903
2904 err_find:
2905         kfree(ctx);
2906 err_ctx:
2907         kfree(names);
2908 err_names:
2909         kfree(callbacks);
2910 err_callback:
2911         kfree(vqs);
2912 err_vq:
2913         return ret;
2914 }
2915
2916 static int virtnet_alloc_queues(struct virtnet_info *vi)
2917 {
2918         int i;
2919
2920         if (vi->has_cvq) {
2921                 vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
2922                 if (!vi->ctrl)
2923                         goto err_ctrl;
2924         } else {
2925                 vi->ctrl = NULL;
2926         }
2927         vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
2928         if (!vi->sq)
2929                 goto err_sq;
2930         vi->rq = kcalloc(vi->max_queue_pairs, sizeof(*vi->rq), GFP_KERNEL);
2931         if (!vi->rq)
2932                 goto err_rq;
2933
2934         INIT_DELAYED_WORK(&vi->refill, refill_work);
2935         for (i = 0; i < vi->max_queue_pairs; i++) {
2936                 vi->rq[i].pages = NULL;
2937                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2938                                napi_weight);
2939                 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2940                                   napi_tx ? napi_weight : 0);
2941
2942                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2943                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2944                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2945
2946                 u64_stats_init(&vi->rq[i].stats.syncp);
2947                 u64_stats_init(&vi->sq[i].stats.syncp);
2948         }
2949
2950         return 0;
2951
2952 err_rq:
2953         kfree(vi->sq);
2954 err_sq:
2955         kfree(vi->ctrl);
2956 err_ctrl:
2957         return -ENOMEM;
2958 }
2959
2960 static int init_vqs(struct virtnet_info *vi)
2961 {
2962         int ret;
2963
2964         /* Allocate send & receive queues */
2965         ret = virtnet_alloc_queues(vi);
2966         if (ret)
2967                 goto err;
2968
2969         ret = virtnet_find_vqs(vi);
2970         if (ret)
2971                 goto err_free;
2972
2973         get_online_cpus();
2974         virtnet_set_affinity(vi);
2975         put_online_cpus();
2976
2977         return 0;
2978
2979 err_free:
2980         virtnet_free_queues(vi);
2981 err:
2982         return ret;
2983 }
2984
2985 #ifdef CONFIG_SYSFS
2986 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2987                 char *buf)
2988 {
2989         struct virtnet_info *vi = netdev_priv(queue->dev);
2990         unsigned int queue_index = get_netdev_rx_queue_index(queue);
2991         unsigned int headroom = virtnet_get_headroom(vi);
2992         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
2993         struct ewma_pkt_len *avg;
2994
2995         BUG_ON(queue_index >= vi->max_queue_pairs);
2996         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2997         return sprintf(buf, "%u\n",
2998                        get_mergeable_buf_len(&vi->rq[queue_index], avg,
2999                                        SKB_DATA_ALIGN(headroom + tailroom)));
3000 }
3001
3002 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
3003         __ATTR_RO(mergeable_rx_buffer_size);
3004
3005 static struct attribute *virtio_net_mrg_rx_attrs[] = {
3006         &mergeable_rx_buffer_size_attribute.attr,
3007         NULL
3008 };
3009
3010 static const struct attribute_group virtio_net_mrg_rx_group = {
3011         .name = "virtio_net",
3012         .attrs = virtio_net_mrg_rx_attrs
3013 };
3014 #endif
3015
3016 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
3017                                     unsigned int fbit,
3018                                     const char *fname, const char *dname)
3019 {
3020         if (!virtio_has_feature(vdev, fbit))
3021                 return false;
3022
3023         dev_err(&vdev->dev, "device advertises feature %s but not %s",
3024                 fname, dname);
3025
3026         return true;
3027 }
3028
3029 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
3030         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
3031
3032 static bool virtnet_validate_features(struct virtio_device *vdev)
3033 {
3034         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
3035             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
3036                              "VIRTIO_NET_F_CTRL_VQ") ||
3037              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
3038                              "VIRTIO_NET_F_CTRL_VQ") ||
3039              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
3040                              "VIRTIO_NET_F_CTRL_VQ") ||
3041              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
3042              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
3043                              "VIRTIO_NET_F_CTRL_VQ"))) {
3044                 return false;
3045         }
3046
3047         return true;
3048 }
3049
3050 #define MIN_MTU ETH_MIN_MTU
3051 #define MAX_MTU ETH_MAX_MTU
3052
3053 static int virtnet_validate(struct virtio_device *vdev)
3054 {
3055         if (!vdev->config->get) {
3056                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
3057                         __func__);
3058                 return -EINVAL;
3059         }
3060
3061         if (!virtnet_validate_features(vdev))
3062                 return -EINVAL;
3063
3064         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3065                 int mtu = virtio_cread16(vdev,
3066                                          offsetof(struct virtio_net_config,
3067                                                   mtu));
3068                 if (mtu < MIN_MTU)
3069                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
3070         }
3071
3072         return 0;
3073 }
3074
3075 static int virtnet_probe(struct virtio_device *vdev)
3076 {
3077         int i, err = -ENOMEM;
3078         struct net_device *dev;
3079         struct virtnet_info *vi;
3080         u16 max_queue_pairs;
3081         int mtu;
3082
3083         /* Find if host supports multiqueue virtio_net device */
3084         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
3085                                    struct virtio_net_config,
3086                                    max_virtqueue_pairs, &max_queue_pairs);
3087
3088         /* We need at least 2 queue's */
3089         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
3090             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
3091             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3092                 max_queue_pairs = 1;
3093
3094         /* Allocate ourselves a network device with room for our info */
3095         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
3096         if (!dev)
3097                 return -ENOMEM;
3098
3099         /* Set up network device as normal. */
3100         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE |
3101                            IFF_TX_SKB_NO_LINEAR;
3102         dev->netdev_ops = &virtnet_netdev;
3103         dev->features = NETIF_F_HIGHDMA;
3104
3105         dev->ethtool_ops = &virtnet_ethtool_ops;
3106         SET_NETDEV_DEV(dev, &vdev->dev);
3107
3108         /* Do we support "hardware" checksums? */
3109         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
3110                 /* This opens up the world of extra features. */
3111                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3112                 if (csum)
3113                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
3114
3115                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
3116                         dev->hw_features |= NETIF_F_TSO
3117                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
3118                 }
3119                 /* Individual feature bits: what can host handle? */
3120                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
3121                         dev->hw_features |= NETIF_F_TSO;
3122                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
3123                         dev->hw_features |= NETIF_F_TSO6;
3124                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
3125                         dev->hw_features |= NETIF_F_TSO_ECN;
3126
3127                 dev->features |= NETIF_F_GSO_ROBUST;
3128
3129                 if (gso)
3130                         dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
3131                 /* (!csum && gso) case will be fixed by register_netdev() */
3132         }
3133         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
3134                 dev->features |= NETIF_F_RXCSUM;
3135         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3136             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
3137                 dev->features |= NETIF_F_GRO_HW;
3138         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
3139                 dev->hw_features |= NETIF_F_GRO_HW;
3140
3141         dev->vlan_features = dev->features;
3142
3143         /* MTU range: 68 - 65535 */
3144         dev->min_mtu = MIN_MTU;
3145         dev->max_mtu = MAX_MTU;
3146
3147         /* Configuration may specify what MAC to use.  Otherwise random. */
3148         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
3149                 virtio_cread_bytes(vdev,
3150                                    offsetof(struct virtio_net_config, mac),
3151                                    dev->dev_addr, dev->addr_len);
3152         else
3153                 eth_hw_addr_random(dev);
3154
3155         /* Set up our device-specific information */
3156         vi = netdev_priv(dev);
3157         vi->dev = dev;
3158         vi->vdev = vdev;
3159         vdev->priv = vi;
3160
3161         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
3162
3163         /* If we can receive ANY GSO packets, we must allocate large ones. */
3164         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
3165             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
3166             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
3167             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
3168                 vi->big_packets = true;
3169
3170         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
3171                 vi->mergeable_rx_bufs = true;
3172
3173         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
3174             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3175                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
3176         else
3177                 vi->hdr_len = sizeof(struct virtio_net_hdr);
3178
3179         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
3180             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
3181                 vi->any_header_sg = true;
3182
3183         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
3184                 vi->has_cvq = true;
3185
3186         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
3187                 mtu = virtio_cread16(vdev,
3188                                      offsetof(struct virtio_net_config,
3189                                               mtu));
3190                 if (mtu < dev->min_mtu) {
3191                         /* Should never trigger: MTU was previously validated
3192                          * in virtnet_validate.
3193                          */
3194                         dev_err(&vdev->dev,
3195                                 "device MTU appears to have changed it is now %d < %d",
3196                                 mtu, dev->min_mtu);
3197                         err = -EINVAL;
3198                         goto free;
3199                 }
3200
3201                 dev->mtu = mtu;
3202                 dev->max_mtu = mtu;
3203
3204                 /* TODO: size buffers correctly in this case. */
3205                 if (dev->mtu > ETH_DATA_LEN)
3206                         vi->big_packets = true;
3207         }
3208
3209         if (vi->any_header_sg)
3210                 dev->needed_headroom = vi->hdr_len;
3211
3212         /* Enable multiqueue by default */
3213         if (num_online_cpus() >= max_queue_pairs)
3214                 vi->curr_queue_pairs = max_queue_pairs;
3215         else
3216                 vi->curr_queue_pairs = num_online_cpus();
3217         vi->max_queue_pairs = max_queue_pairs;
3218
3219         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
3220         err = init_vqs(vi);
3221         if (err)
3222                 goto free;
3223
3224 #ifdef CONFIG_SYSFS
3225         if (vi->mergeable_rx_bufs)
3226                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
3227 #endif
3228         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
3229         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
3230
3231         virtnet_init_settings(dev);
3232
3233         if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3234                 vi->failover = net_failover_create(vi->dev);
3235                 if (IS_ERR(vi->failover)) {
3236                         err = PTR_ERR(vi->failover);
3237                         goto free_vqs;
3238                 }
3239         }
3240
3241         err = register_netdev(dev);
3242         if (err) {
3243                 pr_debug("virtio_net: registering device failed\n");
3244                 goto free_failover;
3245         }
3246
3247         virtio_device_ready(vdev);
3248
3249         err = virtnet_cpu_notif_add(vi);
3250         if (err) {
3251                 pr_debug("virtio_net: registering cpu notifier failed\n");
3252                 goto free_unregister_netdev;
3253         }
3254
3255         virtnet_set_queues(vi, vi->curr_queue_pairs);
3256
3257         /* Assume link up if device can't report link status,
3258            otherwise get link status from config. */
3259         netif_carrier_off(dev);
3260         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
3261                 schedule_work(&vi->config_work);
3262         } else {
3263                 vi->status = VIRTIO_NET_S_LINK_UP;
3264                 virtnet_update_settings(vi);
3265                 netif_carrier_on(dev);
3266         }
3267
3268         for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
3269                 if (virtio_has_feature(vi->vdev, guest_offloads[i]))
3270                         set_bit(guest_offloads[i], &vi->guest_offloads);
3271         vi->guest_offloads_capable = vi->guest_offloads;
3272
3273         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
3274                  dev->name, max_queue_pairs);
3275
3276         return 0;
3277
3278 free_unregister_netdev:
3279         vi->vdev->config->reset(vdev);
3280
3281         unregister_netdev(dev);
3282 free_failover:
3283         net_failover_destroy(vi->failover);
3284 free_vqs:
3285         cancel_delayed_work_sync(&vi->refill);
3286         free_receive_page_frags(vi);
3287         virtnet_del_vqs(vi);
3288 free:
3289         free_netdev(dev);
3290         return err;
3291 }
3292
3293 static void remove_vq_common(struct virtnet_info *vi)
3294 {
3295         vi->vdev->config->reset(vi->vdev);
3296
3297         /* Free unused buffers in both send and recv, if any. */
3298         free_unused_bufs(vi);
3299
3300         free_receive_bufs(vi);
3301
3302         free_receive_page_frags(vi);
3303
3304         virtnet_del_vqs(vi);
3305 }
3306
3307 static void virtnet_remove(struct virtio_device *vdev)
3308 {
3309         struct virtnet_info *vi = vdev->priv;
3310
3311         virtnet_cpu_notif_remove(vi);
3312
3313         /* Make sure no work handler is accessing the device. */
3314         flush_work(&vi->config_work);
3315
3316         unregister_netdev(vi->dev);
3317
3318         net_failover_destroy(vi->failover);
3319
3320         remove_vq_common(vi);
3321
3322         free_netdev(vi->dev);
3323 }
3324
3325 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
3326 {
3327         struct virtnet_info *vi = vdev->priv;
3328
3329         virtnet_cpu_notif_remove(vi);
3330         virtnet_freeze_down(vdev);
3331         remove_vq_common(vi);
3332
3333         return 0;
3334 }
3335
3336 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
3337 {
3338         struct virtnet_info *vi = vdev->priv;
3339         int err;
3340
3341         err = virtnet_restore_up(vdev);
3342         if (err)
3343                 return err;
3344         virtnet_set_queues(vi, vi->curr_queue_pairs);
3345
3346         err = virtnet_cpu_notif_add(vi);
3347         if (err) {
3348                 virtnet_freeze_down(vdev);
3349                 remove_vq_common(vi);
3350                 return err;
3351         }
3352
3353         return 0;
3354 }
3355
3356 static struct virtio_device_id id_table[] = {
3357         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
3358         { 0 },
3359 };
3360
3361 #define VIRTNET_FEATURES \
3362         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
3363         VIRTIO_NET_F_MAC, \
3364         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
3365         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
3366         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
3367         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
3368         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
3369         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
3370         VIRTIO_NET_F_CTRL_MAC_ADDR, \
3371         VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
3372         VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
3373
3374 static unsigned int features[] = {
3375         VIRTNET_FEATURES,
3376 };
3377
3378 static unsigned int features_legacy[] = {
3379         VIRTNET_FEATURES,
3380         VIRTIO_NET_F_GSO,
3381         VIRTIO_F_ANY_LAYOUT,
3382 };
3383
3384 static struct virtio_driver virtio_net_driver = {
3385         .feature_table = features,
3386         .feature_table_size = ARRAY_SIZE(features),
3387         .feature_table_legacy = features_legacy,
3388         .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
3389         .driver.name =  KBUILD_MODNAME,
3390         .driver.owner = THIS_MODULE,
3391         .id_table =     id_table,
3392         .validate =     virtnet_validate,
3393         .probe =        virtnet_probe,
3394         .remove =       virtnet_remove,
3395         .config_changed = virtnet_config_changed,
3396 #ifdef CONFIG_PM_SLEEP
3397         .freeze =       virtnet_freeze,
3398         .restore =      virtnet_restore,
3399 #endif
3400 };
3401
3402 static __init int virtio_net_driver_init(void)
3403 {
3404         int ret;
3405
3406         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
3407                                       virtnet_cpu_online,
3408                                       virtnet_cpu_down_prep);
3409         if (ret < 0)
3410                 goto out;
3411         virtionet_online = ret;
3412         ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
3413                                       NULL, virtnet_cpu_dead);
3414         if (ret)
3415                 goto err_dead;
3416
3417         ret = register_virtio_driver(&virtio_net_driver);
3418         if (ret)
3419                 goto err_virtio;
3420         return 0;
3421 err_virtio:
3422         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3423 err_dead:
3424         cpuhp_remove_multi_state(virtionet_online);
3425 out:
3426         return ret;
3427 }
3428 module_init(virtio_net_driver_init);
3429
3430 static __exit void virtio_net_driver_exit(void)
3431 {
3432         unregister_virtio_driver(&virtio_net_driver);
3433         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3434         cpuhp_remove_multi_state(virtionet_online);
3435 }
3436 module_exit(virtio_net_driver_exit);
3437
3438 MODULE_DEVICE_TABLE(virtio, id_table);
3439 MODULE_DESCRIPTION("Virtio network driver");
3440 MODULE_LICENSE("GPL");