drivers/net/virtio_net.c

   1 /* A network driver using virtio.
   2  *
   3  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18 //#define DEBUG
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/ethtool.h>
  22 #include <linux/module.h>
  23 #include <linux/virtio.h>
  24 #include <linux/virtio_net.h>
  25 #include <linux/bpf.h>
  26 #include <linux/bpf_trace.h>
  27 #include <linux/scatterlist.h>
  28 #include <linux/if_vlan.h>
  29 #include <linux/slab.h>
  30 #include <linux/cpu.h>
  31 #include <linux/average.h>
  32 #include <linux/filter.h>
  33 #include <net/route.h>
  34 #include <net/xdp.h>
  35
  36 static int napi_weight = NAPI_POLL_WEIGHT;
  37 module_param(napi_weight, int, 0444);
  38
  39 static bool csum = true, gso = true, napi_tx;
  40 module_param(csum, bool, 0444);
  41 module_param(gso, bool, 0444);
  42 module_param(napi_tx, bool, 0644);
  43
  44 /* FIXME: MTU in config. */
  45 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  46 #define GOOD_COPY_LEN   128
  47
  48 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
  49
  50 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
  51 #define VIRTIO_XDP_HEADROOM 256
  52
  53 /* RX packet size EWMA. The average packet size is used to determine the packet
  54  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  55  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  56  * term, transient changes in packet size.
  57  */
  58 DECLARE_EWMA(pkt_len, 0, 64)
  59
  60 #define VIRTNET_DRIVER_VERSION "1.0.0"
  61
  62 static const unsigned long guest_offloads[] = {
  63         VIRTIO_NET_F_GUEST_TSO4,
  64         VIRTIO_NET_F_GUEST_TSO6,
  65         VIRTIO_NET_F_GUEST_ECN,
  66         VIRTIO_NET_F_GUEST_UFO
  67 };
  68
  69 struct virtnet_stat_desc {
  70         char desc[ETH_GSTRING_LEN];
  71         size_t offset;
  72 };
  73
  74 struct virtnet_sq_stats {
  75         struct u64_stats_sync syncp;
  76         u64 packets;
  77         u64 bytes;
  78 };
  79
  80 struct virtnet_rq_stats {
  81         struct u64_stats_sync syncp;
  82         u64 packets;
  83         u64 bytes;
  84 };
  85
  86 #define VIRTNET_SQ_STAT(m)      offsetof(struct virtnet_sq_stats, m)
  87 #define VIRTNET_RQ_STAT(m)      offsetof(struct virtnet_rq_stats, m)
  88
  89 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
  90         { "packets",    VIRTNET_SQ_STAT(packets) },
  91         { "bytes",      VIRTNET_SQ_STAT(bytes) },
  92 };
  93
  94 static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
  95         { "packets",    VIRTNET_RQ_STAT(packets) },
  96         { "bytes",      VIRTNET_RQ_STAT(bytes) },
  97 };
  98
  99 #define VIRTNET_SQ_STATS_LEN    ARRAY_SIZE(virtnet_sq_stats_desc)
 100 #define VIRTNET_RQ_STATS_LEN    ARRAY_SIZE(virtnet_rq_stats_desc)
 101
 102 /* Internal representation of a send virtqueue */
 103 struct send_queue {
 104         /* Virtqueue associated with this send _queue */
 105         struct virtqueue *vq;
 106
 107         /* TX: fragments + linear part + virtio header */
 108         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 109
 110         /* Name of the send queue: output.$index */
 111         char name[40];
 112
 113         struct virtnet_sq_stats stats;
 114
 115         struct napi_struct napi;
 116 };
 117
 118 /* Internal representation of a receive virtqueue */
 119 struct receive_queue {
 120         /* Virtqueue associated with this receive_queue */
 121         struct virtqueue *vq;
 122
 123         struct napi_struct napi;
 124
 125         struct bpf_prog __rcu *xdp_prog;
 126
 127         struct virtnet_rq_stats stats;
 128
 129         /* Chain pages by the private ptr. */
 130         struct page *pages;
 131
 132         /* Average packet length for mergeable receive buffers. */
 133         struct ewma_pkt_len mrg_avg_pkt_len;
 134
 135         /* Page frag for packet buffer allocation. */
 136         struct page_frag alloc_frag;
 137
 138         /* RX: fragments + linear part + virtio header */
 139         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 140
 141         /* Min single buffer size for mergeable buffers case. */
 142         unsigned int min_buf_len;
 143
 144         /* Name of this receive queue: input.$index */
 145         char name[40];
 146
 147         struct xdp_rxq_info xdp_rxq;
 148 };
 149
 150 /* Control VQ buffers: protected by the rtnl lock */
 151 struct control_buf {
 152         struct virtio_net_ctrl_hdr hdr;
 153         virtio_net_ctrl_ack status;
 154         struct virtio_net_ctrl_mq mq;
 155         u8 promisc;
 156         u8 allmulti;
 157         __virtio16 vid;
 158         __virtio64 offloads;
 159 };
 160
 161 struct virtnet_info {
 162         struct virtio_device *vdev;
 163         struct virtqueue *cvq;
 164         struct net_device *dev;
 165         struct send_queue *sq;
 166         struct receive_queue *rq;
 167         unsigned int status;
 168
 169         /* Max # of queue pairs supported by the device */
 170         u16 max_queue_pairs;
 171
 172         /* # of queue pairs currently used by the driver */
 173         u16 curr_queue_pairs;
 174
 175         /* # of XDP queue pairs currently used by the driver */
 176         u16 xdp_queue_pairs;
 177
 178         /* I like... big packets and I cannot lie! */
 179         bool big_packets;
 180
 181         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 182         bool mergeable_rx_bufs;
 183
 184         /* Has control virtqueue */
 185         bool has_cvq;
 186
 187         /* Host can handle any s/g split between our header and packet data */
 188         bool any_header_sg;
 189
 190         /* Packet virtio header size */
 191         u8 hdr_len;
 192
 193         /* Work struct for refilling if we run low on memory. */
 194         struct delayed_work refill;
 195
 196         /* Work struct for config space updates */
 197         struct work_struct config_work;
 198
 199         /* Does the affinity hint is set for virtqueues? */
 200         bool affinity_hint_set;
 201
 202         /* CPU hotplug instances for online & dead */
 203         struct hlist_node node;
 204         struct hlist_node node_dead;
 205
 206         struct control_buf *ctrl;
 207
 208         /* Ethtool settings */
 209         u8 duplex;
 210         u32 speed;
 211
 212         unsigned long guest_offloads;
 213 };
 214
 215 struct padded_vnet_hdr {
 216         struct virtio_net_hdr_mrg_rxbuf hdr;
 217         /*
 218          * hdr is in a separate sg buffer, and data sg buffer shares same page
 219          * with this header sg. This padding makes next sg 16 byte aligned
 220          * after the header.
 221          */
 222         char padding[4];
 223 };
 224
 225 /* Converting between virtqueue no. and kernel tx/rx queue no.
 226  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 227  */
 228 static int vq2txq(struct virtqueue *vq)
 229 {
 230         return (vq->index - 1) / 2;
 231 }
 232
 233 static int txq2vq(int txq)
 234 {
 235         return txq * 2 + 1;
 236 }
 237
 238 static int vq2rxq(struct virtqueue *vq)
 239 {
 240         return vq->index / 2;
 241 }
 242
 243 static int rxq2vq(int rxq)
 244 {
 245         return rxq * 2;
 246 }
 247
 248 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 249 {
 250         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 251 }
 252
 253 /*
 254  * private is used to chain pages for big packets, put the whole
 255  * most recent used list in the beginning for reuse
 256  */
 257 static void give_pages(struct receive_queue *rq, struct page *page)
 258 {
 259         struct page *end;
 260
 261         /* Find end of list, sew whole thing into vi->rq.pages. */
 262         for (end = page; end->private; end = (struct page *)end->private);
 263         end->private = (unsigned long)rq->pages;
 264         rq->pages = page;
 265 }
 266
 267 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 268 {
 269         struct page *p = rq->pages;
 270
 271         if (p) {
 272                 rq->pages = (struct page *)p->private;
 273                 /* clear private here, it is used to chain pages */
 274                 p->private = 0;
 275         } else
 276                 p = alloc_page(gfp_mask);
 277         return p;
 278 }
 279
 280 static void virtqueue_napi_schedule(struct napi_struct *napi,
 281                                     struct virtqueue *vq)
 282 {
 283         if (napi_schedule_prep(napi)) {
 284                 virtqueue_disable_cb(vq);
 285                 __napi_schedule(napi);
 286         }
 287 }
 288
 289 static void virtqueue_napi_complete(struct napi_struct *napi,
 290                                     struct virtqueue *vq, int processed)
 291 {
 292         int opaque;
 293
 294         opaque = virtqueue_enable_cb_prepare(vq);
 295         if (napi_complete_done(napi, processed)) {
 296                 if (unlikely(virtqueue_poll(vq, opaque)))
 297                         virtqueue_napi_schedule(napi, vq);
 298         } else {
 299                 virtqueue_disable_cb(vq);
 300         }
 301 }
 302
 303 static void skb_xmit_done(struct virtqueue *vq)
 304 {
 305         struct virtnet_info *vi = vq->vdev->priv;
 306         struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
 307
 308         /* Suppress further interrupts. */
 309         virtqueue_disable_cb(vq);
 310
 311         if (napi->weight)
 312                 virtqueue_napi_schedule(napi, vq);
 313         else
 314                 /* We were probably waiting for more output buffers. */
 315                 netif_wake_subqueue(vi->dev, vq2txq(vq));
 316 }
 317
 318 #define MRG_CTX_HEADER_SHIFT 22
 319 static void *mergeable_len_to_ctx(unsigned int truesize,
 320                                   unsigned int headroom)
 321 {
 322         return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);
 323 }
 324
 325 static unsigned int mergeable_ctx_to_headroom(void *mrg_ctx)
 326 {
 327         return (unsigned long)mrg_ctx >> MRG_CTX_HEADER_SHIFT;
 328 }
 329
 330 static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
 331 {
 332         return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
 333 }
 334
 335 /* Called from bottom half context */
 336 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 337                                    struct receive_queue *rq,
 338                                    struct page *page, unsigned int offset,
 339                                    unsigned int len, unsigned int truesize)
 340 {
 341         struct sk_buff *skb;
 342         struct virtio_net_hdr_mrg_rxbuf *hdr;
 343         unsigned int copy, hdr_len, hdr_padded_len;
 344         char *p;
 345
 346         p = page_address(page) + offset;
 347
 348         /* copy small packet so we can reuse these pages for small data */
 349         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 350         if (unlikely(!skb))
 351                 return NULL;
 352
 353         hdr = skb_vnet_hdr(skb);
 354
 355         hdr_len = vi->hdr_len;
 356         if (vi->mergeable_rx_bufs)
 357                 hdr_padded_len = sizeof(*hdr);
 358         else
 359                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 360
 361         memcpy(hdr, p, hdr_len);
 362
 363         len -= hdr_len;
 364         offset += hdr_padded_len;
 365         p += hdr_padded_len;
 366
 367         copy = len;
 368         if (copy > skb_tailroom(skb))
 369                 copy = skb_tailroom(skb);
 370         skb_put_data(skb, p, copy);
 371
 372         len -= copy;
 373         offset += copy;
 374
 375         if (vi->mergeable_rx_bufs) {
 376                 if (len)
 377                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 378                 else
 379                         put_page(page);
 380                 return skb;
 381         }
 382
 383         /*
 384          * Verify that we can indeed put this data into a skb.
 385          * This is here to handle cases when the device erroneously
 386          * tries to receive more than is possible. This is usually
 387          * the case of a broken device.
 388          */
 389         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 390                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 391                 dev_kfree_skb(skb);
 392                 return NULL;
 393         }
 394         BUG_ON(offset >= PAGE_SIZE);
 395         while (len) {
 396                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 397                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 398                                 frag_size, truesize);
 399                 len -= frag_size;
 400                 page = (struct page *)page->private;
 401                 offset = 0;
 402         }
 403
 404         if (page)
 405                 give_pages(rq, page);
 406
 407         return skb;
 408 }
 409
 410 static void virtnet_xdp_flush(struct net_device *dev)
 411 {
 412         struct virtnet_info *vi = netdev_priv(dev);
 413         struct send_queue *sq;
 414         unsigned int qp;
 415
 416         qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
 417         sq = &vi->sq[qp];
 418
 419         virtqueue_kick(sq->vq);
 420 }
 421
 422 static bool __virtnet_xdp_xmit(struct virtnet_info *vi,
 423                                struct xdp_buff *xdp)
 424 {
 425         struct virtio_net_hdr_mrg_rxbuf *hdr;
 426         unsigned int len;
 427         struct send_queue *sq;
 428         unsigned int qp;
 429         void *xdp_sent;
 430         int err;
 431
 432         qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
 433         sq = &vi->sq[qp];
 434
 435         /* Free up any pending old buffers before queueing new ones. */
 436         while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 437                 struct page *sent_page = virt_to_head_page(xdp_sent);
 438
 439                 put_page(sent_page);
 440         }
 441
 442         xdp->data -= vi->hdr_len;
 443         /* Zero header and leave csum up to XDP layers */
 444         hdr = xdp->data;
 445         memset(hdr, 0, vi->hdr_len);
 446
 447         sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data);
 448
 449         err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp->data, GFP_ATOMIC);
 450         if (unlikely(err))
 451                 return false; /* Caller handle free/refcnt */
 452
 453         return true;
 454 }
 455
 456 static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp)
 457 {
 458         struct virtnet_info *vi = netdev_priv(dev);
 459         struct receive_queue *rq = vi->rq;
 460         struct bpf_prog *xdp_prog;
 461         bool sent;
 462
 463         /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
 464          * indicate XDP resources have been successfully allocated.
 465          */
 466         xdp_prog = rcu_dereference(rq->xdp_prog);
 467         if (!xdp_prog)
 468                 return -ENXIO;
 469
 470         sent = __virtnet_xdp_xmit(vi, xdp);
 471         if (!sent)
 472                 return -ENOSPC;
 473         return 0;
 474 }
 475
 476 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
 477 {
 478         return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
 479 }
 480
 481 /* We copy the packet for XDP in the following cases:
 482  *
 483  * 1) Packet is scattered across multiple rx buffers.
 484  * 2) Headroom space is insufficient.
 485  *
 486  * This is inefficient but it's a temporary condition that
 487  * we hit right after XDP is enabled and until queue is refilled
 488  * with large buffers with sufficient headroom - so it should affect
 489  * at most queue size packets.
 490  * Afterwards, the conditions to enable
 491  * XDP should preclude the underlying device from sending packets
 492  * across multiple buffers (num_buf > 1), and we make sure buffers
 493  * have enough headroom.
 494  */
 495 static struct page *xdp_linearize_page(struct receive_queue *rq,
 496                                        u16 *num_buf,
 497                                        struct page *p,
 498                                        int offset,
 499                                        int page_off,
 500                                        unsigned int *len)
 501 {
 502         struct page *page = alloc_page(GFP_ATOMIC);
 503
 504         if (!page)
 505                 return NULL;
 506
 507         memcpy(page_address(page) + page_off, page_address(p) + offset, *len);
 508         page_off += *len;
 509
 510         while (--*num_buf) {
 511                 int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 512                 unsigned int buflen;
 513                 void *buf;
 514                 int off;
 515
 516                 buf = virtqueue_get_buf(rq->vq, &buflen);
 517                 if (unlikely(!buf))
 518                         goto err_buf;
 519
 520                 p = virt_to_head_page(buf);
 521                 off = buf - page_address(p);
 522
 523                 /* guard against a misconfigured or uncooperative backend that
 524                  * is sending packet larger than the MTU.
 525                  */
 526                 if ((page_off + buflen + tailroom) > PAGE_SIZE) {
 527                         put_page(p);
 528                         goto err_buf;
 529                 }
 530
 531                 memcpy(page_address(page) + page_off,
 532                        page_address(p) + off, buflen);
 533                 page_off += buflen;
 534                 put_page(p);
 535         }
 536
 537         /* Headroom does not contribute to packet length */
 538         *len = page_off - VIRTIO_XDP_HEADROOM;
 539         return page;
 540 err_buf:
 541         __free_pages(page, 0);
 542         return NULL;
 543 }
 544
 545 static struct sk_buff *receive_small(struct net_device *dev,
 546                                      struct virtnet_info *vi,
 547                                      struct receive_queue *rq,
 548                                      void *buf, void *ctx,
 549                                      unsigned int len,
 550                                      bool *xdp_xmit)
 551 {
 552         struct sk_buff *skb;
 553         struct bpf_prog *xdp_prog;
 554         unsigned int xdp_headroom = (unsigned long)ctx;
 555         unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
 556         unsigned int headroom = vi->hdr_len + header_offset;
 557         unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 558                               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 559         struct page *page = virt_to_head_page(buf);
 560         unsigned int delta = 0;
 561         struct page *xdp_page;
 562         bool sent;
 563         int err;
 564
 565         len -= vi->hdr_len;
 566
 567         rcu_read_lock();
 568         xdp_prog = rcu_dereference(rq->xdp_prog);
 569         if (xdp_prog) {
 570                 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
 571                 struct xdp_buff xdp;
 572                 void *orig_data;
 573                 u32 act;
 574
 575                 if (unlikely(hdr->hdr.gso_type))
 576                         goto err_xdp;
 577
 578                 if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) {
 579                         int offset = buf - page_address(page) + header_offset;
 580                         unsigned int tlen = len + vi->hdr_len;
 581                         u16 num_buf = 1;
 582
 583                         xdp_headroom = virtnet_get_headroom(vi);
 584                         header_offset = VIRTNET_RX_PAD + xdp_headroom;
 585                         headroom = vi->hdr_len + header_offset;
 586                         buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 587                                  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 588                         xdp_page = xdp_linearize_page(rq, &num_buf, page,
 589                                                       offset, header_offset,
 590                                                       &tlen);
 591                         if (!xdp_page)
 592                                 goto err_xdp;
 593
 594                         buf = page_address(xdp_page);
 595                         put_page(page);
 596                         page = xdp_page;
 597                 }
 598
 599                 xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
 600                 xdp.data = xdp.data_hard_start + xdp_headroom;
 601                 xdp_set_data_meta_invalid(&xdp);
 602                 xdp.data_end = xdp.data + len;
 603                 xdp.rxq = &rq->xdp_rxq;
 604                 orig_data = xdp.data;
 605                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 606
 607                 switch (act) {
 608                 case XDP_PASS:
 609                         /* Recalculate length in case bpf program changed it */
 610                         delta = orig_data - xdp.data;
 611                         break;
 612                 case XDP_TX:
 613                         sent = __virtnet_xdp_xmit(vi, &xdp);
 614                         if (unlikely(!sent)) {
 615                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 616                                 goto err_xdp;
 617                         }
 618                         *xdp_xmit = true;
 619                         rcu_read_unlock();
 620                         goto xdp_xmit;
 621                 case XDP_REDIRECT:
 622                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
 623                         if (err)
 624                                 goto err_xdp;
 625                         *xdp_xmit = true;
 626                         rcu_read_unlock();
 627                         goto xdp_xmit;
 628                 default:
 629                         bpf_warn_invalid_xdp_action(act);
 630                 case XDP_ABORTED:
 631                         trace_xdp_exception(vi->dev, xdp_prog, act);
 632                 case XDP_DROP:
 633                         goto err_xdp;
 634                 }
 635         }
 636         rcu_read_unlock();
 637
 638         skb = build_skb(buf, buflen);
 639         if (!skb) {
 640                 put_page(page);
 641                 goto err;
 642         }
 643         skb_reserve(skb, headroom - delta);
 644         skb_put(skb, len + delta);
 645         if (!delta) {
 646                 buf += header_offset;
 647                 memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
 648         } /* keep zeroed vnet hdr since packet was changed by bpf */
 649
 650 err:
 651         return skb;
 652
 653 err_xdp:
 654         rcu_read_unlock();
 655         dev->stats.rx_dropped++;
 656         put_page(page);
 657 xdp_xmit:
 658         return NULL;
 659 }
 660
 661 static struct sk_buff *receive_big(struct net_device *dev,
 662                                    struct virtnet_info *vi,
 663                                    struct receive_queue *rq,
 664                                    void *buf,
 665                                    unsigned int len)
 666 {
 667         struct page *page = buf;
 668         struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 669
 670         if (unlikely(!skb))
 671                 goto err;
 672
 673         return skb;
 674
 675 err:
 676         dev->stats.rx_dropped++;
 677         give_pages(rq, page);
 678         return NULL;
 679 }
 680
 681 static struct sk_buff *receive_mergeable(struct net_device *dev,
 682                                          struct virtnet_info *vi,
 683                                          struct receive_queue *rq,
 684                                          void *buf,
 685                                          void *ctx,
 686                                          unsigned int len,
 687                                          bool *xdp_xmit)
 688 {
 689         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 690         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 691         struct page *page = virt_to_head_page(buf);
 692         int offset = buf - page_address(page);
 693         struct sk_buff *head_skb, *curr_skb;
 694         struct bpf_prog *xdp_prog;
 695         unsigned int truesize;
 696         unsigned int headroom = mergeable_ctx_to_headroom(ctx);
 697         bool sent;
 698         int err;
 699
 700         head_skb = NULL;
 701
 702         rcu_read_lock();
 703         xdp_prog = rcu_dereference(rq->xdp_prog);
 704         if (xdp_prog) {
 705                 struct page *xdp_page;
 706                 struct xdp_buff xdp;
 707                 void *data;
 708                 u32 act;
 709
 710                 /* This happens when rx buffer size is underestimated
 711                  * or headroom is not enough because of the buffer
 712                  * was refilled before XDP is set. This should only
 713                  * happen for the first several packets, so we don't
 714                  * care much about its performance.
 715                  */
 716                 if (unlikely(num_buf > 1 ||
 717                              headroom < virtnet_get_headroom(vi))) {
 718                         /* linearize data for XDP */
 719                         xdp_page = xdp_linearize_page(rq, &num_buf,
 720                                                       page, offset,
 721                                                       VIRTIO_XDP_HEADROOM,
 722                                                       &len);
 723                         if (!xdp_page)
 724                                 goto err_xdp;
 725                         offset = VIRTIO_XDP_HEADROOM;
 726                 } else {
 727                         xdp_page = page;
 728                 }
 729
 730                 /* Transient failure which in theory could occur if
 731                  * in-flight packets from before XDP was enabled reach
 732                  * the receive path after XDP is loaded. In practice I
 733                  * was not able to create this condition.
 734                  */
 735                 if (unlikely(hdr->hdr.gso_type))
 736                         goto err_xdp;
 737
 738                 /* Allow consuming headroom but reserve enough space to push
 739                  * the descriptor on if we get an XDP_TX return code.
 740                  */
 741                 data = page_address(xdp_page) + offset;
 742                 xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
 743                 xdp.data = data + vi->hdr_len;
 744                 xdp_set_data_meta_invalid(&xdp);
 745                 xdp.data_end = xdp.data + (len - vi->hdr_len);
 746                 xdp.rxq = &rq->xdp_rxq;
 747
 748                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 749
 750                 switch (act) {
 751                 case XDP_PASS:
 752                         /* recalculate offset to account for any header
 753                          * adjustments. Note other cases do not build an
 754                          * skb and avoid using offset
 755                          */
 756                         offset = xdp.data -
 757                                         page_address(xdp_page) - vi->hdr_len;
 758
 759                         /* We can only create skb based on xdp_page. */
 760                         if (unlikely(xdp_page != page)) {
 761                                 rcu_read_unlock();
 762                                 put_page(page);
 763                                 head_skb = page_to_skb(vi, rq, xdp_page,
 764                                                        offset, len, PAGE_SIZE);
 765                                 return head_skb;
 766                         }
 767                         break;
 768                 case XDP_TX:
 769                         sent = __virtnet_xdp_xmit(vi, &xdp);
 770                         if (unlikely(!sent)) {
 771                                 trace_xdp_exception(vi->dev, xdp_prog, act);
 772                                 if (unlikely(xdp_page != page))
 773                                         put_page(xdp_page);
 774                                 goto err_xdp;
 775                         }
 776                         *xdp_xmit = true;
 777                         if (unlikely(xdp_page != page))
 778                                 goto err_xdp;
 779                         rcu_read_unlock();
 780                         goto xdp_xmit;
 781                 case XDP_REDIRECT:
 782                         err = xdp_do_redirect(dev, &xdp, xdp_prog);
 783                         if (err) {
 784                                 if (unlikely(xdp_page != page))
 785                                         put_page(xdp_page);
 786                                 goto err_xdp;
 787                         }
 788                         *xdp_xmit = true;
 789                         if (unlikely(xdp_page != page))
 790                                 goto err_xdp;
 791                         rcu_read_unlock();
 792                         goto xdp_xmit;
 793                 default:
 794                         bpf_warn_invalid_xdp_action(act);
 795                 case XDP_ABORTED:
 796                         trace_xdp_exception(vi->dev, xdp_prog, act);
 797                 case XDP_DROP:
 798                         if (unlikely(xdp_page != page))
 799                                 __free_pages(xdp_page, 0);
 800                         goto err_xdp;
 801                 }
 802         }
 803         rcu_read_unlock();
 804
 805         truesize = mergeable_ctx_to_truesize(ctx);
 806         if (unlikely(len > truesize)) {
 807                 pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 808                          dev->name, len, (unsigned long)ctx);
 809                 dev->stats.rx_length_errors++;
 810                 goto err_skb;
 811         }
 812
 813         head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
 814         curr_skb = head_skb;
 815
 816         if (unlikely(!curr_skb))
 817                 goto err_skb;
 818         while (--num_buf) {
 819                 int num_skb_frags;
 820
 821                 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
 822                 if (unlikely(!buf)) {
 823                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 824                                  dev->name, num_buf,
 825                                  virtio16_to_cpu(vi->vdev,
 826                                                  hdr->num_buffers));
 827                         dev->stats.rx_length_errors++;
 828                         goto err_buf;
 829                 }
 830
 831                 page = virt_to_head_page(buf);
 832
 833                 truesize = mergeable_ctx_to_truesize(ctx);
 834                 if (unlikely(len > truesize)) {
 835                         pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 836                                  dev->name, len, (unsigned long)ctx);
 837                         dev->stats.rx_length_errors++;
 838                         goto err_skb;
 839                 }
 840
 841                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 842                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 843                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 844
 845                         if (unlikely(!nskb))
 846                                 goto err_skb;
 847                         if (curr_skb == head_skb)
 848                                 skb_shinfo(curr_skb)->frag_list = nskb;
 849                         else
 850                                 curr_skb->next = nskb;
 851                         curr_skb = nskb;
 852                         head_skb->truesize += nskb->truesize;
 853                         num_skb_frags = 0;
 854                 }
 855                 if (curr_skb != head_skb) {
 856                         head_skb->data_len += len;
 857                         head_skb->len += len;
 858                         head_skb->truesize += truesize;
 859                 }
 860                 offset = buf - page_address(page);
 861                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 862                         put_page(page);
 863                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 864                                              len, truesize);
 865                 } else {
 866                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 867                                         offset, len, truesize);
 868                 }
 869         }
 870
 871         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
 872         return head_skb;
 873
 874 err_xdp:
 875         rcu_read_unlock();
 876 err_skb:
 877         put_page(page);
 878         while (--num_buf) {
 879                 buf = virtqueue_get_buf(rq->vq, &len);
 880                 if (unlikely(!buf)) {
 881                         pr_debug("%s: rx error: %d buffers missing\n",
 882                                  dev->name, num_buf);
 883                         dev->stats.rx_length_errors++;
 884                         break;
 885                 }
 886                 page = virt_to_head_page(buf);
 887                 put_page(page);
 888         }
 889 err_buf:
 890         dev->stats.rx_dropped++;
 891         dev_kfree_skb(head_skb);
 892 xdp_xmit:
 893         return NULL;
 894 }
 895
 896 static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 897                        void *buf, unsigned int len, void **ctx, bool *xdp_xmit)
 898 {
 899         struct net_device *dev = vi->dev;
 900         struct sk_buff *skb;
 901         struct virtio_net_hdr_mrg_rxbuf *hdr;
 902         int ret;
 903
 904         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 905                 pr_debug("%s: short packet %i\n", dev->name, len);
 906                 dev->stats.rx_length_errors++;
 907                 if (vi->mergeable_rx_bufs) {
 908                         put_page(virt_to_head_page(buf));
 909                 } else if (vi->big_packets) {
 910                         give_pages(rq, buf);
 911                 } else {
 912                         put_page(virt_to_head_page(buf));
 913                 }
 914                 return 0;
 915         }
 916
 917         if (vi->mergeable_rx_bufs)
 918                 skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit);
 919         else if (vi->big_packets)
 920                 skb = receive_big(dev, vi, rq, buf, len);
 921         else
 922                 skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit);
 923
 924         if (unlikely(!skb))
 925                 return 0;
 926
 927         hdr = skb_vnet_hdr(skb);
 928
 929         ret = skb->len;
 930
 931         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
 932                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 933
 934         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
 935                                   virtio_is_little_endian(vi->vdev))) {
 936                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
 937                                      dev->name, hdr->hdr.gso_type,
 938                                      hdr->hdr.gso_size);
 939                 goto frame_err;
 940         }
 941
 942         skb->protocol = eth_type_trans(skb, dev);
 943         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 944                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 945
 946         napi_gro_receive(&rq->napi, skb);
 947         return ret;
 948
 949 frame_err:
 950         dev->stats.rx_frame_errors++;
 951         dev_kfree_skb(skb);
 952         return 0;
 953 }
 954
 955 /* Unlike mergeable buffers, all buffers are allocated to the
 956  * same size, except for the headroom. For this reason we do
 957  * not need to use  mergeable_len_to_ctx here - it is enough
 958  * to store the headroom as the context ignoring the truesize.
 959  */
 960 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 961                              gfp_t gfp)
 962 {
 963         struct page_frag *alloc_frag = &rq->alloc_frag;
 964         char *buf;
 965         unsigned int xdp_headroom = virtnet_get_headroom(vi);
 966         void *ctx = (void *)(unsigned long)xdp_headroom;
 967         int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom;
 968         int err;
 969
 970         len = SKB_DATA_ALIGN(len) +
 971               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 972         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 973                 return -ENOMEM;
 974
 975         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 976         get_page(alloc_frag->page);
 977         alloc_frag->offset += len;
 978         sg_init_one(rq->sg, buf + VIRTNET_RX_PAD + xdp_headroom,
 979                     vi->hdr_len + GOOD_PACKET_LEN);
 980         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
 981         if (err < 0)
 982                 put_page(virt_to_head_page(buf));
 983         return err;
 984 }
 985
 986 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
 987                            gfp_t gfp)
 988 {
 989         struct page *first, *list = NULL;
 990         char *p;
 991         int i, err, offset;
 992
 993         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 994
 995         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 996         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 997                 first = get_a_page(rq, gfp);
 998                 if (!first) {
 999                         if (list)
1000                                 give_pages(rq, list);
1001                         return -ENOMEM;
1002                 }
1003                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
1004
1005                 /* chain new page in list head to match sg */
1006                 first->private = (unsigned long)list;
1007                 list = first;
1008         }
1009
1010         first = get_a_page(rq, gfp);
1011         if (!first) {
1012                 give_pages(rq, list);
1013                 return -ENOMEM;
1014         }
1015         p = page_address(first);
1016
1017         /* rq->sg[0], rq->sg[1] share the same page */
1018         /* a separated rq->sg[0] for header - required in case !any_header_sg */
1019         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
1020
1021         /* rq->sg[1] for data packet, from offset */
1022         offset = sizeof(struct padded_vnet_hdr);
1023         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
1024
1025         /* chain first in list head */
1026         first->private = (unsigned long)list;
1027         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
1028                                   first, gfp);
1029         if (err < 0)
1030                 give_pages(rq, first);
1031
1032         return err;
1033 }
1034
1035 static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
1036                                           struct ewma_pkt_len *avg_pkt_len,
1037                                           unsigned int room)
1038 {
1039         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1040         unsigned int len;
1041
1042         if (room)
1043                 return PAGE_SIZE - room;
1044
1045         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
1046                                 rq->min_buf_len, PAGE_SIZE - hdr_len);
1047
1048         return ALIGN(len, L1_CACHE_BYTES);
1049 }
1050
1051 static int add_recvbuf_mergeable(struct virtnet_info *vi,
1052                                  struct receive_queue *rq, gfp_t gfp)
1053 {
1054         struct page_frag *alloc_frag = &rq->alloc_frag;
1055         unsigned int headroom = virtnet_get_headroom(vi);
1056         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
1057         unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
1058         char *buf;
1059         void *ctx;
1060         int err;
1061         unsigned int len, hole;
1062
1063         /* Extra tailroom is needed to satisfy XDP's assumption. This
1064          * means rx frags coalescing won't work, but consider we've
1065          * disabled GSO for XDP, it won't be a big issue.
1066          */
1067         len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room);
1068         if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp)))
1069                 return -ENOMEM;
1070
1071         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1072         buf += headroom; /* advance address leaving hole at front of pkt */
1073         get_page(alloc_frag->page);
1074         alloc_frag->offset += len + room;
1075         hole = alloc_frag->size - alloc_frag->offset;
1076         if (hole < len + room) {
1077                 /* To avoid internal fragmentation, if there is very likely not
1078                  * enough space for another buffer, add the remaining space to
1079                  * the current buffer.
1080                  */
1081                 len += hole;
1082                 alloc_frag->offset += hole;
1083         }
1084
1085         sg_init_one(rq->sg, buf, len);
1086         ctx = mergeable_len_to_ctx(len, headroom);
1087         err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
1088         if (err < 0)
1089                 put_page(virt_to_head_page(buf));
1090
1091         return err;
1092 }
1093
1094 /*
1095  * Returns false if we couldn't fill entirely (OOM).
1096  *
1097  * Normally run in the receive path, but can also be run from ndo_open
1098  * before we're receiving packets, or from refill_work which is
1099  * careful to disable receiving (using napi_disable).
1100  */
1101 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
1102                           gfp_t gfp)
1103 {
1104         int err;
1105         bool oom;
1106
1107         do {
1108                 if (vi->mergeable_rx_bufs)
1109                         err = add_recvbuf_mergeable(vi, rq, gfp);
1110                 else if (vi->big_packets)
1111                         err = add_recvbuf_big(vi, rq, gfp);
1112                 else
1113                         err = add_recvbuf_small(vi, rq, gfp);
1114
1115                 oom = err == -ENOMEM;
1116                 if (err)
1117                         break;
1118         } while (rq->vq->num_free);
1119         virtqueue_kick(rq->vq);
1120         return !oom;
1121 }
1122
1123 static void skb_recv_done(struct virtqueue *rvq)
1124 {
1125         struct virtnet_info *vi = rvq->vdev->priv;
1126         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
1127
1128         virtqueue_napi_schedule(&rq->napi, rvq);
1129 }
1130
1131 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
1132 {
1133         napi_enable(napi);
1134
1135         /* If all buffers were filled by other side before we napi_enabled, we
1136          * won't get another interrupt, so process any outstanding packets now.
1137          * Call local_bh_enable after to trigger softIRQ processing.
1138          */
1139         local_bh_disable();
1140         virtqueue_napi_schedule(napi, vq);
1141         local_bh_enable();
1142 }
1143
1144 static void virtnet_napi_tx_enable(struct virtnet_info *vi,
1145                                    struct virtqueue *vq,
1146                                    struct napi_struct *napi)
1147 {
1148         if (!napi->weight)
1149                 return;
1150
1151         /* Tx napi touches cachelines on the cpu handling tx interrupts. Only
1152          * enable the feature if this is likely affine with the transmit path.
1153          */
1154         if (!vi->affinity_hint_set) {
1155                 napi->weight = 0;
1156                 return;
1157         }
1158
1159         return virtnet_napi_enable(vq, napi);
1160 }
1161
1162 static void virtnet_napi_tx_disable(struct napi_struct *napi)
1163 {
1164         if (napi->weight)
1165                 napi_disable(napi);
1166 }
1167
1168 static void refill_work(struct work_struct *work)
1169 {
1170         struct virtnet_info *vi =
1171                 container_of(work, struct virtnet_info, refill.work);
1172         bool still_empty;
1173         int i;
1174
1175         for (i = 0; i < vi->curr_queue_pairs; i++) {
1176                 struct receive_queue *rq = &vi->rq[i];
1177
1178                 napi_disable(&rq->napi);
1179                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
1180                 virtnet_napi_enable(rq->vq, &rq->napi);
1181
1182                 /* In theory, this can happen: if we don't get any buffers in
1183                  * we will *never* try to fill again.
1184                  */
1185                 if (still_empty)
1186                         schedule_delayed_work(&vi->refill, HZ/2);
1187         }
1188 }
1189
1190 static int virtnet_receive(struct receive_queue *rq, int budget, bool *xdp_xmit)
1191 {
1192         struct virtnet_info *vi = rq->vq->vdev->priv;
1193         unsigned int len, received = 0, bytes = 0;
1194         void *buf;
1195
1196         if (!vi->big_packets || vi->mergeable_rx_bufs) {
1197                 void *ctx;
1198
1199                 while (received < budget &&
1200                        (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
1201                         bytes += receive_buf(vi, rq, buf, len, ctx, xdp_xmit);
1202                         received++;
1203                 }
1204         } else {
1205                 while (received < budget &&
1206                        (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
1207                         bytes += receive_buf(vi, rq, buf, len, NULL, xdp_xmit);
1208                         received++;
1209                 }
1210         }
1211
1212         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
1213                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
1214                         schedule_delayed_work(&vi->refill, 0);
1215         }
1216
1217         u64_stats_update_begin(&rq->stats.syncp);
1218         rq->stats.bytes += bytes;
1219         rq->stats.packets += received;
1220         u64_stats_update_end(&rq->stats.syncp);
1221
1222         return received;
1223 }
1224
1225 static void free_old_xmit_skbs(struct send_queue *sq)
1226 {
1227         struct sk_buff *skb;
1228         unsigned int len;
1229         unsigned int packets = 0;
1230         unsigned int bytes = 0;
1231
1232         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
1233                 pr_debug("Sent skb %p\n", skb);
1234
1235                 bytes += skb->len;
1236                 packets++;
1237
1238                 dev_consume_skb_any(skb);
1239         }
1240
1241         /* Avoid overhead when no packets have been processed
1242          * happens when called speculatively from start_xmit.
1243          */
1244         if (!packets)
1245                 return;
1246
1247         u64_stats_update_begin(&sq->stats.syncp);
1248         sq->stats.bytes += bytes;
1249         sq->stats.packets += packets;
1250         u64_stats_update_end(&sq->stats.syncp);
1251 }
1252
1253 static void virtnet_poll_cleantx(struct receive_queue *rq)
1254 {
1255         struct virtnet_info *vi = rq->vq->vdev->priv;
1256         unsigned int index = vq2rxq(rq->vq);
1257         struct send_queue *sq = &vi->sq[index];
1258         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
1259
1260         if (!sq->napi.weight)
1261                 return;
1262
1263         if (__netif_tx_trylock(txq)) {
1264                 free_old_xmit_skbs(sq);
1265                 __netif_tx_unlock(txq);
1266         }
1267
1268         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1269                 netif_tx_wake_queue(txq);
1270 }
1271
1272 static int virtnet_poll(struct napi_struct *napi, int budget)
1273 {
1274         struct receive_queue *rq =
1275                 container_of(napi, struct receive_queue, napi);
1276         struct virtnet_info *vi = rq->vq->vdev->priv;
1277         struct send_queue *sq;
1278         unsigned int received, qp;
1279         bool xdp_xmit = false;
1280
1281         virtnet_poll_cleantx(rq);
1282
1283         received = virtnet_receive(rq, budget, &xdp_xmit);
1284
1285         /* Out of packets? */
1286         if (received < budget)
1287                 virtqueue_napi_complete(napi, rq->vq, received);
1288
1289         if (xdp_xmit) {
1290                 qp = vi->curr_queue_pairs - vi->xdp_queue_pairs +
1291                      smp_processor_id();
1292                 sq = &vi->sq[qp];
1293                 virtqueue_kick(sq->vq);
1294                 xdp_do_flush_map();
1295         }
1296
1297         return received;
1298 }
1299
1300 static int virtnet_open(struct net_device *dev)
1301 {
1302         struct virtnet_info *vi = netdev_priv(dev);
1303         int i, err;
1304
1305         for (i = 0; i < vi->max_queue_pairs; i++) {
1306                 if (i < vi->curr_queue_pairs)
1307                         /* Make sure we have some buffers: if oom use wq. */
1308                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1309                                 schedule_delayed_work(&vi->refill, 0);
1310
1311                 err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i);
1312                 if (err < 0)
1313                         return err;
1314
1315                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
1316                 virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
1317         }
1318
1319         return 0;
1320 }
1321
1322 static int virtnet_poll_tx(struct napi_struct *napi, int budget)
1323 {
1324         struct send_queue *sq = container_of(napi, struct send_queue, napi);
1325         struct virtnet_info *vi = sq->vq->vdev->priv;
1326         struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
1327
1328         __netif_tx_lock(txq, raw_smp_processor_id());
1329         free_old_xmit_skbs(sq);
1330         __netif_tx_unlock(txq);
1331
1332         virtqueue_napi_complete(napi, sq->vq, 0);
1333
1334         if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
1335                 netif_tx_wake_queue(txq);
1336
1337         return 0;
1338 }
1339
1340 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
1341 {
1342         struct virtio_net_hdr_mrg_rxbuf *hdr;
1343         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
1344         struct virtnet_info *vi = sq->vq->vdev->priv;
1345         int num_sg;
1346         unsigned hdr_len = vi->hdr_len;
1347         bool can_push;
1348
1349         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
1350
1351         can_push = vi->any_header_sg &&
1352                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
1353                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
1354         /* Even if we can, don't push here yet as this would skew
1355          * csum_start offset below. */
1356         if (can_push)
1357                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
1358         else
1359                 hdr = skb_vnet_hdr(skb);
1360
1361         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
1362                                     virtio_is_little_endian(vi->vdev), false))
1363                 BUG();
1364
1365         if (vi->mergeable_rx_bufs)
1366                 hdr->num_buffers = 0;
1367
1368         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
1369         if (can_push) {
1370                 __skb_push(skb, hdr_len);
1371                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
1372                 if (unlikely(num_sg < 0))
1373                         return num_sg;
1374                 /* Pull header back to avoid skew in tx bytes calculations. */
1375                 __skb_pull(skb, hdr_len);
1376         } else {
1377                 sg_set_buf(sq->sg, hdr, hdr_len);
1378                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
1379                 if (unlikely(num_sg < 0))
1380                         return num_sg;
1381                 num_sg++;
1382         }
1383         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
1384 }
1385
1386 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
1387 {
1388         struct virtnet_info *vi = netdev_priv(dev);
1389         int qnum = skb_get_queue_mapping(skb);
1390         struct send_queue *sq = &vi->sq[qnum];
1391         int err;
1392         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
1393         bool kick = !skb->xmit_more;
1394         bool use_napi = sq->napi.weight;
1395
1396         /* Free up any pending old buffers before queueing new ones. */
1397         free_old_xmit_skbs(sq);
1398
1399         if (use_napi && kick)
1400                 virtqueue_enable_cb_delayed(sq->vq);
1401
1402         /* timestamp packet in software */
1403         skb_tx_timestamp(skb);
1404
1405         /* Try to transmit */
1406         err = xmit_skb(sq, skb);
1407
1408         /* This should not happen! */
1409         if (unlikely(err)) {
1410                 dev->stats.tx_fifo_errors++;
1411                 if (net_ratelimit())
1412                         dev_warn(&dev->dev,
1413                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
1414                 dev->stats.tx_dropped++;
1415                 dev_kfree_skb_any(skb);
1416                 return NETDEV_TX_OK;
1417         }
1418
1419         /* Don't wait up for transmitted skbs to be freed. */
1420         if (!use_napi) {
1421                 skb_orphan(skb);
1422                 nf_reset(skb);
1423         }
1424
1425         /* If running out of space, stop queue to avoid getting packets that we
1426          * are then unable to transmit.
1427          * An alternative would be to force queuing layer to requeue the skb by
1428          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
1429          * returned in a normal path of operation: it means that driver is not
1430          * maintaining the TX queue stop/start state properly, and causes
1431          * the stack to do a non-trivial amount of useless work.
1432          * Since most packets only take 1 or 2 ring slots, stopping the queue
1433          * early means 16 slots are typically wasted.
1434          */
1435         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
1436                 netif_stop_subqueue(dev, qnum);
1437                 if (!use_napi &&
1438                     unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
1439                         /* More just got used, free them then recheck. */
1440                         free_old_xmit_skbs(sq);
1441                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
1442                                 netif_start_subqueue(dev, qnum);
1443                                 virtqueue_disable_cb(sq->vq);
1444                         }
1445                 }
1446         }
1447
1448         if (kick || netif_xmit_stopped(txq))
1449                 virtqueue_kick(sq->vq);
1450
1451         return NETDEV_TX_OK;
1452 }
1453
1454 /*
1455  * Send command via the control virtqueue and check status.  Commands
1456  * supported by the hypervisor, as indicated by feature bits, should
1457  * never fail unless improperly formatted.
1458  */
1459 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
1460                                  struct scatterlist *out)
1461 {
1462         struct scatterlist *sgs[4], hdr, stat;
1463         unsigned out_num = 0, tmp;
1464
1465         /* Caller should know better */
1466         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
1467
1468         vi->ctrl->status = ~0;
1469         vi->ctrl->hdr.class = class;
1470         vi->ctrl->hdr.cmd = cmd;
1471         /* Add header */
1472         sg_init_one(&hdr, &vi->ctrl->hdr, sizeof(vi->ctrl->hdr));
1473         sgs[out_num++] = &hdr;
1474
1475         if (out)
1476                 sgs[out_num++] = out;
1477
1478         /* Add return status. */
1479         sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
1480         sgs[out_num] = &stat;
1481
1482         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1483         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1484
1485         if (unlikely(!virtqueue_kick(vi->cvq)))
1486                 return vi->ctrl->status == VIRTIO_NET_OK;
1487
1488         /* Spin for a response, the kick causes an ioport write, trapping
1489          * into the hypervisor, so the request should be handled immediately.
1490          */
1491         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1492                !virtqueue_is_broken(vi->cvq))
1493                 cpu_relax();
1494
1495         return vi->ctrl->status == VIRTIO_NET_OK;
1496 }
1497
1498 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1499 {
1500         struct virtnet_info *vi = netdev_priv(dev);
1501         struct virtio_device *vdev = vi->vdev;
1502         int ret;
1503         struct sockaddr *addr;
1504         struct scatterlist sg;
1505
1506         addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
1507         if (!addr)
1508                 return -ENOMEM;
1509
1510         ret = eth_prepare_mac_addr_change(dev, addr);
1511         if (ret)
1512                 goto out;
1513
1514         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1515                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1516                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1517                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1518                         dev_warn(&vdev->dev,
1519                                  "Failed to set mac address by vq command.\n");
1520                         ret = -EINVAL;
1521                         goto out;
1522                 }
1523         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1524                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1525                 unsigned int i;
1526
1527                 /* Naturally, this has an atomicity problem. */
1528                 for (i = 0; i < dev->addr_len; i++)
1529                         virtio_cwrite8(vdev,
1530                                        offsetof(struct virtio_net_config, mac) +
1531                                        i, addr->sa_data[i]);
1532         }
1533
1534         eth_commit_mac_addr_change(dev, p);
1535         ret = 0;
1536
1537 out:
1538         kfree(addr);
1539         return ret;
1540 }
1541
1542 static void virtnet_stats(struct net_device *dev,
1543                           struct rtnl_link_stats64 *tot)
1544 {
1545         struct virtnet_info *vi = netdev_priv(dev);
1546         unsigned int start;
1547         int i;
1548
1549         for (i = 0; i < vi->max_queue_pairs; i++) {
1550                 u64 tpackets, tbytes, rpackets, rbytes;
1551                 struct receive_queue *rq = &vi->rq[i];
1552                 struct send_queue *sq = &vi->sq[i];
1553
1554                 do {
1555                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1556                         tpackets = sq->stats.packets;
1557                         tbytes   = sq->stats.bytes;
1558                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1559
1560                 do {
1561                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1562                         rpackets = rq->stats.packets;
1563                         rbytes   = rq->stats.bytes;
1564                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1565
1566                 tot->rx_packets += rpackets;
1567                 tot->tx_packets += tpackets;
1568                 tot->rx_bytes   += rbytes;
1569                 tot->tx_bytes   += tbytes;
1570         }
1571
1572         tot->tx_dropped = dev->stats.tx_dropped;
1573         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1574         tot->rx_dropped = dev->stats.rx_dropped;
1575         tot->rx_length_errors = dev->stats.rx_length_errors;
1576         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1577 }
1578
1579 #ifdef CONFIG_NET_POLL_CONTROLLER
1580 static void virtnet_netpoll(struct net_device *dev)
1581 {
1582         struct virtnet_info *vi = netdev_priv(dev);
1583         int i;
1584
1585         for (i = 0; i < vi->curr_queue_pairs; i++)
1586                 napi_schedule(&vi->rq[i].napi);
1587 }
1588 #endif
1589
1590 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1591 {
1592         rtnl_lock();
1593         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1594                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1595                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1596         rtnl_unlock();
1597 }
1598
1599 static int _virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1600 {
1601         struct scatterlist sg;
1602         struct net_device *dev = vi->dev;
1603
1604         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1605                 return 0;
1606
1607         vi->ctrl->mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1608         sg_init_one(&sg, &vi->ctrl->mq, sizeof(vi->ctrl->mq));
1609
1610         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1611                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1612                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1613                          queue_pairs);
1614                 return -EINVAL;
1615         } else {
1616                 vi->curr_queue_pairs = queue_pairs;
1617                 /* virtnet_open() will refill when device is going to up. */
1618                 if (dev->flags & IFF_UP)
1619                         schedule_delayed_work(&vi->refill, 0);
1620         }
1621
1622         return 0;
1623 }
1624
1625 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1626 {
1627         int err;
1628
1629         rtnl_lock();
1630         err = _virtnet_set_queues(vi, queue_pairs);
1631         rtnl_unlock();
1632         return err;
1633 }
1634
1635 static int virtnet_close(struct net_device *dev)
1636 {
1637         struct virtnet_info *vi = netdev_priv(dev);
1638         int i;
1639
1640         /* Make sure refill_work doesn't re-enable napi! */
1641         cancel_delayed_work_sync(&vi->refill);
1642
1643         for (i = 0; i < vi->max_queue_pairs; i++) {
1644                 xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
1645                 napi_disable(&vi->rq[i].napi);
1646                 virtnet_napi_tx_disable(&vi->sq[i].napi);
1647         }
1648
1649         return 0;
1650 }
1651
1652 static void virtnet_set_rx_mode(struct net_device *dev)
1653 {
1654         struct virtnet_info *vi = netdev_priv(dev);
1655         struct scatterlist sg[2];
1656         struct virtio_net_ctrl_mac *mac_data;
1657         struct netdev_hw_addr *ha;
1658         int uc_count;
1659         int mc_count;
1660         void *buf;
1661         int i;
1662
1663         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1664         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1665                 return;
1666
1667         vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
1668         vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1669
1670         sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));
1671
1672         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1673                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1674                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1675                          vi->ctrl->promisc ? "en" : "dis");
1676
1677         sg_init_one(sg, &vi->ctrl->allmulti, sizeof(vi->ctrl->allmulti));
1678
1679         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1680                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1681                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1682                          vi->ctrl->allmulti ? "en" : "dis");
1683
1684         uc_count = netdev_uc_count(dev);
1685         mc_count = netdev_mc_count(dev);
1686         /* MAC filter - use one buffer for both lists */
1687         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1688                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1689         mac_data = buf;
1690         if (!buf)
1691                 return;
1692
1693         sg_init_table(sg, 2);
1694
1695         /* Store the unicast list and count in the front of the buffer */
1696         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1697         i = 0;
1698         netdev_for_each_uc_addr(ha, dev)
1699                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1700
1701         sg_set_buf(&sg[0], mac_data,
1702                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1703
1704         /* multicast list and count fill the end */
1705         mac_data = (void *)&mac_data->macs[uc_count][0];
1706
1707         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1708         i = 0;
1709         netdev_for_each_mc_addr(ha, dev)
1710                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1711
1712         sg_set_buf(&sg[1], mac_data,
1713                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1714
1715         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1716                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1717                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1718
1719         kfree(buf);
1720 }
1721
1722 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1723                                    __be16 proto, u16 vid)
1724 {
1725         struct virtnet_info *vi = netdev_priv(dev);
1726         struct scatterlist sg;
1727
1728         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1729         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1730
1731         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1732                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1733                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1734         return 0;
1735 }
1736
1737 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1738                                     __be16 proto, u16 vid)
1739 {
1740         struct virtnet_info *vi = netdev_priv(dev);
1741         struct scatterlist sg;
1742
1743         vi->ctrl->vid = cpu_to_virtio16(vi->vdev, vid);
1744         sg_init_one(&sg, &vi->ctrl->vid, sizeof(vi->ctrl->vid));
1745
1746         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1747                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1748                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1749         return 0;
1750 }
1751
1752 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1753 {
1754         int i;
1755
1756         if (vi->affinity_hint_set) {
1757                 for (i = 0; i < vi->max_queue_pairs; i++) {
1758                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1759                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1760                 }
1761
1762                 vi->affinity_hint_set = false;
1763         }
1764 }
1765
1766 static void virtnet_set_affinity(struct virtnet_info *vi)
1767 {
1768         int i;
1769         int cpu;
1770
1771         /* In multiqueue mode, when the number of cpu is equal to the number of
1772          * queue pairs, we let the queue pairs to be private to one cpu by
1773          * setting the affinity hint to eliminate the contention.
1774          */
1775         if (vi->curr_queue_pairs == 1 ||
1776             vi->max_queue_pairs != num_online_cpus()) {
1777                 virtnet_clean_affinity(vi, -1);
1778                 return;
1779         }
1780
1781         i = 0;
1782         for_each_online_cpu(cpu) {
1783                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1784                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1785                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1786                 i++;
1787         }
1788
1789         vi->affinity_hint_set = true;
1790 }
1791
1792 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1793 {
1794         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1795                                                    node);
1796         virtnet_set_affinity(vi);
1797         return 0;
1798 }
1799
1800 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1801 {
1802         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1803                                                    node_dead);
1804         virtnet_set_affinity(vi);
1805         return 0;
1806 }
1807
1808 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1809 {
1810         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1811                                                    node);
1812
1813         virtnet_clean_affinity(vi, cpu);
1814         return 0;
1815 }
1816
1817 static enum cpuhp_state virtionet_online;
1818
1819 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1820 {
1821         int ret;
1822
1823         ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
1824         if (ret)
1825                 return ret;
1826         ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1827                                                &vi->node_dead);
1828         if (!ret)
1829                 return ret;
1830         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1831         return ret;
1832 }
1833
1834 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
1835 {
1836         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1837         cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1838                                             &vi->node_dead);
1839 }
1840
1841 static void virtnet_get_ringparam(struct net_device *dev,
1842                                 struct ethtool_ringparam *ring)
1843 {
1844         struct virtnet_info *vi = netdev_priv(dev);
1845
1846         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1847         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1848         ring->rx_pending = ring->rx_max_pending;
1849         ring->tx_pending = ring->tx_max_pending;
1850 }
1851
1852
1853 static void virtnet_get_drvinfo(struct net_device *dev,
1854                                 struct ethtool_drvinfo *info)
1855 {
1856         struct virtnet_info *vi = netdev_priv(dev);
1857         struct virtio_device *vdev = vi->vdev;
1858
1859         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1860         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1861         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1862
1863 }
1864
1865 /* TODO: Eliminate OOO packets during switching */
1866 static int virtnet_set_channels(struct net_device *dev,
1867                                 struct ethtool_channels *channels)
1868 {
1869         struct virtnet_info *vi = netdev_priv(dev);
1870         u16 queue_pairs = channels->combined_count;
1871         int err;
1872
1873         /* We don't support separate rx/tx channels.
1874          * We don't allow setting 'other' channels.
1875          */
1876         if (channels->rx_count || channels->tx_count || channels->other_count)
1877                 return -EINVAL;
1878
1879         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1880                 return -EINVAL;
1881
1882         /* For now we don't support modifying channels while XDP is loaded
1883          * also when XDP is loaded all RX queues have XDP programs so we only
1884          * need to check a single RX queue.
1885          */
1886         if (vi->rq[0].xdp_prog)
1887                 return -EINVAL;
1888
1889         get_online_cpus();
1890         err = _virtnet_set_queues(vi, queue_pairs);
1891         if (!err) {
1892                 netif_set_real_num_tx_queues(dev, queue_pairs);
1893                 netif_set_real_num_rx_queues(dev, queue_pairs);
1894
1895                 virtnet_set_affinity(vi);
1896         }
1897         put_online_cpus();
1898
1899         return err;
1900 }
1901
1902 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
1903 {
1904         struct virtnet_info *vi = netdev_priv(dev);
1905         char *p = (char *)data;
1906         unsigned int i, j;
1907
1908         switch (stringset) {
1909         case ETH_SS_STATS:
1910                 for (i = 0; i < vi->curr_queue_pairs; i++) {
1911                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
1912                                 snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
1913                                          i, virtnet_rq_stats_desc[j].desc);
1914                                 p += ETH_GSTRING_LEN;
1915                         }
1916                 }
1917
1918                 for (i = 0; i < vi->curr_queue_pairs; i++) {
1919                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
1920                                 snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
1921                                          i, virtnet_sq_stats_desc[j].desc);
1922                                 p += ETH_GSTRING_LEN;
1923                         }
1924                 }
1925                 break;
1926         }
1927 }
1928
1929 static int virtnet_get_sset_count(struct net_device *dev, int sset)
1930 {
1931         struct virtnet_info *vi = netdev_priv(dev);
1932
1933         switch (sset) {
1934         case ETH_SS_STATS:
1935                 return vi->curr_queue_pairs * (VIRTNET_RQ_STATS_LEN +
1936                                                VIRTNET_SQ_STATS_LEN);
1937         default:
1938                 return -EOPNOTSUPP;
1939         }
1940 }
1941
1942 static void virtnet_get_ethtool_stats(struct net_device *dev,
1943                                       struct ethtool_stats *stats, u64 *data)
1944 {
1945         struct virtnet_info *vi = netdev_priv(dev);
1946         unsigned int idx = 0, start, i, j;
1947         const u8 *stats_base;
1948         size_t offset;
1949
1950         for (i = 0; i < vi->curr_queue_pairs; i++) {
1951                 struct receive_queue *rq = &vi->rq[i];
1952
1953                 stats_base = (u8 *)&rq->stats;
1954                 do {
1955                         start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
1956                         for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
1957                                 offset = virtnet_rq_stats_desc[j].offset;
1958                                 data[idx + j] = *(u64 *)(stats_base + offset);
1959                         }
1960                 } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
1961                 idx += VIRTNET_RQ_STATS_LEN;
1962         }
1963
1964         for (i = 0; i < vi->curr_queue_pairs; i++) {
1965                 struct send_queue *sq = &vi->sq[i];
1966
1967                 stats_base = (u8 *)&sq->stats;
1968                 do {
1969                         start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
1970                         for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
1971                                 offset = virtnet_sq_stats_desc[j].offset;
1972                                 data[idx + j] = *(u64 *)(stats_base + offset);
1973                         }
1974                 } while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
1975                 idx += VIRTNET_SQ_STATS_LEN;
1976         }
1977 }
1978
1979 static void virtnet_get_channels(struct net_device *dev,
1980                                  struct ethtool_channels *channels)
1981 {
1982         struct virtnet_info *vi = netdev_priv(dev);
1983
1984         channels->combined_count = vi->curr_queue_pairs;
1985         channels->max_combined = vi->max_queue_pairs;
1986         channels->max_other = 0;
1987         channels->rx_count = 0;
1988         channels->tx_count = 0;
1989         channels->other_count = 0;
1990 }
1991
1992 /* Check if the user is trying to change anything besides speed/duplex */
1993 static bool
1994 virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
1995 {
1996         struct ethtool_link_ksettings diff1 = *cmd;
1997         struct ethtool_link_ksettings diff2 = {};
1998
1999         /* cmd is always set so we need to clear it, validate the port type
2000          * and also without autonegotiation we can ignore advertising
2001          */
2002         diff1.base.speed = 0;
2003         diff2.base.port = PORT_OTHER;
2004         ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
2005         diff1.base.duplex = 0;
2006         diff1.base.cmd = 0;
2007         diff1.base.link_mode_masks_nwords = 0;
2008
2009         return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
2010                 bitmap_empty(diff1.link_modes.supported,
2011                              __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2012                 bitmap_empty(diff1.link_modes.advertising,
2013                              __ETHTOOL_LINK_MODE_MASK_NBITS) &&
2014                 bitmap_empty(diff1.link_modes.lp_advertising,
2015                              __ETHTOOL_LINK_MODE_MASK_NBITS);
2016 }
2017
2018 static int virtnet_set_link_ksettings(struct net_device *dev,
2019                                       const struct ethtool_link_ksettings *cmd)
2020 {
2021         struct virtnet_info *vi = netdev_priv(dev);
2022         u32 speed;
2023
2024         speed = cmd->base.speed;
2025         /* don't allow custom speed and duplex */
2026         if (!ethtool_validate_speed(speed) ||
2027             !ethtool_validate_duplex(cmd->base.duplex) ||
2028             !virtnet_validate_ethtool_cmd(cmd))
2029                 return -EINVAL;
2030         vi->speed = speed;
2031         vi->duplex = cmd->base.duplex;
2032
2033         return 0;
2034 }
2035
2036 static int virtnet_get_link_ksettings(struct net_device *dev,
2037                                       struct ethtool_link_ksettings *cmd)
2038 {
2039         struct virtnet_info *vi = netdev_priv(dev);
2040
2041         cmd->base.speed = vi->speed;
2042         cmd->base.duplex = vi->duplex;
2043         cmd->base.port = PORT_OTHER;
2044
2045         return 0;
2046 }
2047
2048 static void virtnet_init_settings(struct net_device *dev)
2049 {
2050         struct virtnet_info *vi = netdev_priv(dev);
2051
2052         vi->speed = SPEED_UNKNOWN;
2053         vi->duplex = DUPLEX_UNKNOWN;
2054 }
2055
2056 static void virtnet_update_settings(struct virtnet_info *vi)
2057 {
2058         u32 speed;
2059         u8 duplex;
2060
2061         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
2062                 return;
2063
2064         speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
2065                                                   speed));
2066         if (ethtool_validate_speed(speed))
2067                 vi->speed = speed;
2068         duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
2069                                                   duplex));
2070         if (ethtool_validate_duplex(duplex))
2071                 vi->duplex = duplex;
2072 }
2073
2074 static const struct ethtool_ops virtnet_ethtool_ops = {
2075         .get_drvinfo = virtnet_get_drvinfo,
2076         .get_link = ethtool_op_get_link,
2077         .get_ringparam = virtnet_get_ringparam,
2078         .get_strings = virtnet_get_strings,
2079         .get_sset_count = virtnet_get_sset_count,
2080         .get_ethtool_stats = virtnet_get_ethtool_stats,
2081         .set_channels = virtnet_set_channels,
2082         .get_channels = virtnet_get_channels,
2083         .get_ts_info = ethtool_op_get_ts_info,
2084         .get_link_ksettings = virtnet_get_link_ksettings,
2085         .set_link_ksettings = virtnet_set_link_ksettings,
2086 };
2087
2088 static void virtnet_freeze_down(struct virtio_device *vdev)
2089 {
2090         struct virtnet_info *vi = vdev->priv;
2091         int i;
2092
2093         /* Make sure no work handler is accessing the device */
2094         flush_work(&vi->config_work);
2095
2096         netif_device_detach(vi->dev);
2097         netif_tx_disable(vi->dev);
2098         cancel_delayed_work_sync(&vi->refill);
2099
2100         if (netif_running(vi->dev)) {
2101                 for (i = 0; i < vi->max_queue_pairs; i++) {
2102                         napi_disable(&vi->rq[i].napi);
2103                         virtnet_napi_tx_disable(&vi->sq[i].napi);
2104                 }
2105         }
2106 }
2107
2108 static int init_vqs(struct virtnet_info *vi);
2109
2110 static int virtnet_restore_up(struct virtio_device *vdev)
2111 {
2112         struct virtnet_info *vi = vdev->priv;
2113         int err, i;
2114
2115         err = init_vqs(vi);
2116         if (err)
2117                 return err;
2118
2119         virtio_device_ready(vdev);
2120
2121         if (netif_running(vi->dev)) {
2122                 for (i = 0; i < vi->curr_queue_pairs; i++)
2123                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2124                                 schedule_delayed_work(&vi->refill, 0);
2125
2126                 for (i = 0; i < vi->max_queue_pairs; i++) {
2127                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2128                         virtnet_napi_tx_enable(vi, vi->sq[i].vq,
2129                                                &vi->sq[i].napi);
2130                 }
2131         }
2132
2133         netif_device_attach(vi->dev);
2134         return err;
2135 }
2136
2137 static int virtnet_set_guest_offloads(struct virtnet_info *vi, u64 offloads)
2138 {
2139         struct scatterlist sg;
2140         vi->ctrl->offloads = cpu_to_virtio64(vi->vdev, offloads);
2141
2142         sg_init_one(&sg, &vi->ctrl->offloads, sizeof(vi->ctrl->offloads));
2143
2144         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
2145                                   VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &sg)) {
2146                 dev_warn(&vi->dev->dev, "Fail to set guest offload. \n");
2147                 return -EINVAL;
2148         }
2149
2150         return 0;
2151 }
2152
2153 static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
2154 {
2155         u64 offloads = 0;
2156
2157         if (!vi->guest_offloads)
2158                 return 0;
2159
2160         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
2161                 offloads = 1ULL << VIRTIO_NET_F_GUEST_CSUM;
2162
2163         return virtnet_set_guest_offloads(vi, offloads);
2164 }
2165
2166 static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
2167 {
2168         u64 offloads = vi->guest_offloads;
2169
2170         if (!vi->guest_offloads)
2171                 return 0;
2172         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
2173                 offloads |= 1ULL << VIRTIO_NET_F_GUEST_CSUM;
2174
2175         return virtnet_set_guest_offloads(vi, offloads);
2176 }
2177
2178 static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
2179                            struct netlink_ext_ack *extack)
2180 {
2181         unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
2182         struct virtnet_info *vi = netdev_priv(dev);
2183         struct bpf_prog *old_prog;
2184         u16 xdp_qp = 0, curr_qp;
2185         int i, err;
2186
2187         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
2188             && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2189                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2190                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
2191                 virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO))) {
2192                 NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO, disable LRO first");
2193                 return -EOPNOTSUPP;
2194         }
2195
2196         if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
2197                 NL_SET_ERR_MSG_MOD(extack, "XDP expects header/data in single page, any_header_sg required");
2198                 return -EINVAL;
2199         }
2200
2201         if (dev->mtu > max_sz) {
2202                 NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
2203                 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
2204                 return -EINVAL;
2205         }
2206
2207         curr_qp = vi->curr_queue_pairs - vi->xdp_queue_pairs;
2208         if (prog)
2209                 xdp_qp = nr_cpu_ids;
2210
2211         /* XDP requires extra queues for XDP_TX */
2212         if (curr_qp + xdp_qp > vi->max_queue_pairs) {
2213                 NL_SET_ERR_MSG_MOD(extack, "Too few free TX rings available");
2214                 netdev_warn(dev, "request %i queues but max is %i\n",
2215                             curr_qp + xdp_qp, vi->max_queue_pairs);
2216                 return -ENOMEM;
2217         }
2218
2219         if (prog) {
2220                 prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
2221                 if (IS_ERR(prog))
2222                         return PTR_ERR(prog);
2223         }
2224
2225         /* Make sure NAPI is not using any XDP TX queues for RX. */
2226         if (netif_running(dev))
2227                 for (i = 0; i < vi->max_queue_pairs; i++)
2228                         napi_disable(&vi->rq[i].napi);
2229
2230         netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
2231         err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
2232         if (err)
2233                 goto err;
2234         vi->xdp_queue_pairs = xdp_qp;
2235
2236         for (i = 0; i < vi->max_queue_pairs; i++) {
2237                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2238                 rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
2239                 if (i == 0) {
2240                         if (!old_prog)
2241                                 virtnet_clear_guest_offloads(vi);
2242                         if (!prog)
2243                                 virtnet_restore_guest_offloads(vi);
2244                 }
2245                 if (old_prog)
2246                         bpf_prog_put(old_prog);
2247                 if (netif_running(dev))
2248                         virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2249         }
2250
2251         return 0;
2252
2253 err:
2254         for (i = 0; i < vi->max_queue_pairs; i++)
2255                 virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
2256         if (prog)
2257                 bpf_prog_sub(prog, vi->max_queue_pairs - 1);
2258         return err;
2259 }
2260
2261 static u32 virtnet_xdp_query(struct net_device *dev)
2262 {
2263         struct virtnet_info *vi = netdev_priv(dev);
2264         const struct bpf_prog *xdp_prog;
2265         int i;
2266
2267         for (i = 0; i < vi->max_queue_pairs; i++) {
2268                 xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2269                 if (xdp_prog)
2270                         return xdp_prog->aux->id;
2271         }
2272         return 0;
2273 }
2274
2275 static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
2276 {
2277         switch (xdp->command) {
2278         case XDP_SETUP_PROG:
2279                 return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
2280         case XDP_QUERY_PROG:
2281                 xdp->prog_id = virtnet_xdp_query(dev);
2282                 xdp->prog_attached = !!xdp->prog_id;
2283                 return 0;
2284         default:
2285                 return -EINVAL;
2286         }
2287 }
2288
2289 static const struct net_device_ops virtnet_netdev = {
2290         .ndo_open            = virtnet_open,
2291         .ndo_stop            = virtnet_close,
2292         .ndo_start_xmit      = start_xmit,
2293         .ndo_validate_addr   = eth_validate_addr,
2294         .ndo_set_mac_address = virtnet_set_mac_address,
2295         .ndo_set_rx_mode     = virtnet_set_rx_mode,
2296         .ndo_get_stats64     = virtnet_stats,
2297         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
2298         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
2299 #ifdef CONFIG_NET_POLL_CONTROLLER
2300         .ndo_poll_controller = virtnet_netpoll,
2301 #endif
2302         .ndo_bpf                = virtnet_xdp,
2303         .ndo_xdp_xmit           = virtnet_xdp_xmit,
2304         .ndo_xdp_flush          = virtnet_xdp_flush,
2305         .ndo_features_check     = passthru_features_check,
2306 };
2307
2308 static void virtnet_config_changed_work(struct work_struct *work)
2309 {
2310         struct virtnet_info *vi =
2311                 container_of(work, struct virtnet_info, config_work);
2312         u16 v;
2313
2314         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
2315                                  struct virtio_net_config, status, &v) < 0)
2316                 return;
2317
2318         if (v & VIRTIO_NET_S_ANNOUNCE) {
2319                 netdev_notify_peers(vi->dev);
2320                 virtnet_ack_link_announce(vi);
2321         }
2322
2323         /* Ignore unknown (future) status bits */
2324         v &= VIRTIO_NET_S_LINK_UP;
2325
2326         if (vi->status == v)
2327                 return;
2328
2329         vi->status = v;
2330
2331         if (vi->status & VIRTIO_NET_S_LINK_UP) {
2332                 virtnet_update_settings(vi);
2333                 netif_carrier_on(vi->dev);
2334                 netif_tx_wake_all_queues(vi->dev);
2335         } else {
2336                 netif_carrier_off(vi->dev);
2337                 netif_tx_stop_all_queues(vi->dev);
2338         }
2339 }
2340
2341 static void virtnet_config_changed(struct virtio_device *vdev)
2342 {
2343         struct virtnet_info *vi = vdev->priv;
2344
2345         schedule_work(&vi->config_work);
2346 }
2347
2348 static void virtnet_free_queues(struct virtnet_info *vi)
2349 {
2350         int i;
2351
2352         for (i = 0; i < vi->max_queue_pairs; i++) {
2353                 napi_hash_del(&vi->rq[i].napi);
2354                 netif_napi_del(&vi->rq[i].napi);
2355                 netif_napi_del(&vi->sq[i].napi);
2356         }
2357
2358         /* We called napi_hash_del() before netif_napi_del(),
2359          * we need to respect an RCU grace period before freeing vi->rq
2360          */
2361         synchronize_net();
2362
2363         kfree(vi->rq);
2364         kfree(vi->sq);
2365         kfree(vi->ctrl);
2366 }
2367
2368 static void _free_receive_bufs(struct virtnet_info *vi)
2369 {
2370         struct bpf_prog *old_prog;
2371         int i;
2372
2373         for (i = 0; i < vi->max_queue_pairs; i++) {
2374                 while (vi->rq[i].pages)
2375                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
2376
2377                 old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
2378                 RCU_INIT_POINTER(vi->rq[i].xdp_prog, NULL);
2379                 if (old_prog)
2380                         bpf_prog_put(old_prog);
2381         }
2382 }
2383
2384 static void free_receive_bufs(struct virtnet_info *vi)
2385 {
2386         rtnl_lock();
2387         _free_receive_bufs(vi);
2388         rtnl_unlock();
2389 }
2390
2391 static void free_receive_page_frags(struct virtnet_info *vi)
2392 {
2393         int i;
2394         for (i = 0; i < vi->max_queue_pairs; i++)
2395                 if (vi->rq[i].alloc_frag.page)
2396                         put_page(vi->rq[i].alloc_frag.page);
2397 }
2398
2399 static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
2400 {
2401         if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
2402                 return false;
2403         else if (q < vi->curr_queue_pairs)
2404                 return true;
2405         else
2406                 return false;
2407 }
2408
2409 static void free_unused_bufs(struct virtnet_info *vi)
2410 {
2411         void *buf;
2412         int i;
2413
2414         for (i = 0; i < vi->max_queue_pairs; i++) {
2415                 struct virtqueue *vq = vi->sq[i].vq;
2416                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2417                         if (!is_xdp_raw_buffer_queue(vi, i))
2418                                 dev_kfree_skb(buf);
2419                         else
2420                                 put_page(virt_to_head_page(buf));
2421                 }
2422         }
2423
2424         for (i = 0; i < vi->max_queue_pairs; i++) {
2425                 struct virtqueue *vq = vi->rq[i].vq;
2426
2427                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
2428                         if (vi->mergeable_rx_bufs) {
2429                                 put_page(virt_to_head_page(buf));
2430                         } else if (vi->big_packets) {
2431                                 give_pages(&vi->rq[i], buf);
2432                         } else {
2433                                 put_page(virt_to_head_page(buf));
2434                         }
2435                 }
2436         }
2437 }
2438
2439 static void virtnet_del_vqs(struct virtnet_info *vi)
2440 {
2441         struct virtio_device *vdev = vi->vdev;
2442
2443         virtnet_clean_affinity(vi, -1);
2444
2445         vdev->config->del_vqs(vdev);
2446
2447         virtnet_free_queues(vi);
2448 }
2449
2450 /* How large should a single buffer be so a queue full of these can fit at
2451  * least one full packet?
2452  * Logic below assumes the mergeable buffer header is used.
2453  */
2454 static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq)
2455 {
2456         const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2457         unsigned int rq_size = virtqueue_get_vring_size(vq);
2458         unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu;
2459         unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len;
2460         unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size);
2461
2462         return max(max(min_buf_len, hdr_len) - hdr_len,
2463                    (unsigned int)GOOD_PACKET_LEN);
2464 }
2465
2466 static int virtnet_find_vqs(struct virtnet_info *vi)
2467 {
2468         vq_callback_t **callbacks;
2469         struct virtqueue **vqs;
2470         int ret = -ENOMEM;
2471         int i, total_vqs;
2472         const char **names;
2473         bool *ctx;
2474
2475         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
2476          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
2477          * possible control vq.
2478          */
2479         total_vqs = vi->max_queue_pairs * 2 +
2480                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
2481
2482         /* Allocate space for find_vqs parameters */
2483         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
2484         if (!vqs)
2485                 goto err_vq;
2486         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
2487         if (!callbacks)
2488                 goto err_callback;
2489         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
2490         if (!names)
2491                 goto err_names;
2492         if (!vi->big_packets || vi->mergeable_rx_bufs) {
2493                 ctx = kzalloc(total_vqs * sizeof(*ctx), GFP_KERNEL);
2494                 if (!ctx)
2495                         goto err_ctx;
2496         } else {
2497                 ctx = NULL;
2498         }
2499
2500         /* Parameters for control virtqueue, if any */
2501         if (vi->has_cvq) {
2502                 callbacks[total_vqs - 1] = NULL;
2503                 names[total_vqs - 1] = "control";
2504         }
2505
2506         /* Allocate/initialize parameters for send/receive virtqueues */
2507         for (i = 0; i < vi->max_queue_pairs; i++) {
2508                 callbacks[rxq2vq(i)] = skb_recv_done;
2509                 callbacks[txq2vq(i)] = skb_xmit_done;
2510                 sprintf(vi->rq[i].name, "input.%d", i);
2511                 sprintf(vi->sq[i].name, "output.%d", i);
2512                 names[rxq2vq(i)] = vi->rq[i].name;
2513                 names[txq2vq(i)] = vi->sq[i].name;
2514                 if (ctx)
2515                         ctx[rxq2vq(i)] = true;
2516         }
2517
2518         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
2519                                          names, ctx, NULL);
2520         if (ret)
2521                 goto err_find;
2522
2523         if (vi->has_cvq) {
2524                 vi->cvq = vqs[total_vqs - 1];
2525                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
2526                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2527         }
2528
2529         for (i = 0; i < vi->max_queue_pairs; i++) {
2530                 vi->rq[i].vq = vqs[rxq2vq(i)];
2531                 vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
2532                 vi->sq[i].vq = vqs[txq2vq(i)];
2533         }
2534
2535         kfree(names);
2536         kfree(callbacks);
2537         kfree(vqs);
2538         kfree(ctx);
2539
2540         return 0;
2541
2542 err_find:
2543         kfree(ctx);
2544 err_ctx:
2545         kfree(names);
2546 err_names:
2547         kfree(callbacks);
2548 err_callback:
2549         kfree(vqs);
2550 err_vq:
2551         return ret;
2552 }
2553
2554 static int virtnet_alloc_queues(struct virtnet_info *vi)
2555 {
2556         int i;
2557
2558         vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
2559         if (!vi->ctrl)
2560                 goto err_ctrl;
2561         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
2562         if (!vi->sq)
2563                 goto err_sq;
2564         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
2565         if (!vi->rq)
2566                 goto err_rq;
2567
2568         INIT_DELAYED_WORK(&vi->refill, refill_work);
2569         for (i = 0; i < vi->max_queue_pairs; i++) {
2570                 vi->rq[i].pages = NULL;
2571                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
2572                                napi_weight);
2573                 netif_tx_napi_add(vi->dev, &vi->sq[i].napi, virtnet_poll_tx,
2574                                   napi_tx ? napi_weight : 0);
2575
2576                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
2577                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
2578                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
2579
2580                 u64_stats_init(&vi->rq[i].stats.syncp);
2581                 u64_stats_init(&vi->sq[i].stats.syncp);
2582         }
2583
2584         return 0;
2585
2586 err_rq:
2587         kfree(vi->sq);
2588 err_sq:
2589         kfree(vi->ctrl);
2590 err_ctrl:
2591         return -ENOMEM;
2592 }
2593
2594 static int init_vqs(struct virtnet_info *vi)
2595 {
2596         int ret;
2597
2598         /* Allocate send & receive queues */
2599         ret = virtnet_alloc_queues(vi);
2600         if (ret)
2601                 goto err;
2602
2603         ret = virtnet_find_vqs(vi);
2604         if (ret)
2605                 goto err_free;
2606
2607         get_online_cpus();
2608         virtnet_set_affinity(vi);
2609         put_online_cpus();
2610
2611         return 0;
2612
2613 err_free:
2614         virtnet_free_queues(vi);
2615 err:
2616         return ret;
2617 }
2618
2619 #ifdef CONFIG_SYSFS
2620 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
2621                 char *buf)
2622 {
2623         struct virtnet_info *vi = netdev_priv(queue->dev);
2624         unsigned int queue_index = get_netdev_rx_queue_index(queue);
2625         unsigned int headroom = virtnet_get_headroom(vi);
2626         unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
2627         struct ewma_pkt_len *avg;
2628
2629         BUG_ON(queue_index >= vi->max_queue_pairs);
2630         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
2631         return sprintf(buf, "%u\n",
2632                        get_mergeable_buf_len(&vi->rq[queue_index], avg,
2633                                        SKB_DATA_ALIGN(headroom + tailroom)));
2634 }
2635
2636 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
2637         __ATTR_RO(mergeable_rx_buffer_size);
2638
2639 static struct attribute *virtio_net_mrg_rx_attrs[] = {
2640         &mergeable_rx_buffer_size_attribute.attr,
2641         NULL
2642 };
2643
2644 static const struct attribute_group virtio_net_mrg_rx_group = {
2645         .name = "virtio_net",
2646         .attrs = virtio_net_mrg_rx_attrs
2647 };
2648 #endif
2649
2650 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
2651                                     unsigned int fbit,
2652                                     const char *fname, const char *dname)
2653 {
2654         if (!virtio_has_feature(vdev, fbit))
2655                 return false;
2656
2657         dev_err(&vdev->dev, "device advertises feature %s but not %s",
2658                 fname, dname);
2659
2660         return true;
2661 }
2662
2663 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
2664         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
2665
2666 static bool virtnet_validate_features(struct virtio_device *vdev)
2667 {
2668         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
2669             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
2670                              "VIRTIO_NET_F_CTRL_VQ") ||
2671              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
2672                              "VIRTIO_NET_F_CTRL_VQ") ||
2673              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
2674                              "VIRTIO_NET_F_CTRL_VQ") ||
2675              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
2676              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
2677                              "VIRTIO_NET_F_CTRL_VQ"))) {
2678                 return false;
2679         }
2680
2681         return true;
2682 }
2683
2684 #define MIN_MTU ETH_MIN_MTU
2685 #define MAX_MTU ETH_MAX_MTU
2686
2687 static int virtnet_validate(struct virtio_device *vdev)
2688 {
2689         if (!vdev->config->get) {
2690                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
2691                         __func__);
2692                 return -EINVAL;
2693         }
2694
2695         if (!virtnet_validate_features(vdev))
2696                 return -EINVAL;
2697
2698         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2699                 int mtu = virtio_cread16(vdev,
2700                                          offsetof(struct virtio_net_config,
2701                                                   mtu));
2702                 if (mtu < MIN_MTU)
2703                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
2704         }
2705
2706         return 0;
2707 }
2708
2709 static int virtnet_probe(struct virtio_device *vdev)
2710 {
2711         int i, err = -ENOMEM;
2712         struct net_device *dev;
2713         struct virtnet_info *vi;
2714         u16 max_queue_pairs;
2715         int mtu;
2716
2717         /* Find if host supports multiqueue virtio_net device */
2718         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
2719                                    struct virtio_net_config,
2720                                    max_virtqueue_pairs, &max_queue_pairs);
2721
2722         /* We need at least 2 queue's */
2723         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
2724             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
2725             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2726                 max_queue_pairs = 1;
2727
2728         /* Allocate ourselves a network device with room for our info */
2729         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
2730         if (!dev)
2731                 return -ENOMEM;
2732
2733         /* Set up network device as normal. */
2734         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
2735         dev->netdev_ops = &virtnet_netdev;
2736         dev->features = NETIF_F_HIGHDMA;
2737
2738         dev->ethtool_ops = &virtnet_ethtool_ops;
2739         SET_NETDEV_DEV(dev, &vdev->dev);
2740
2741         /* Do we support "hardware" checksums? */
2742         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
2743                 /* This opens up the world of extra features. */
2744                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2745                 if (csum)
2746                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
2747
2748                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
2749                         dev->hw_features |= NETIF_F_TSO
2750                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
2751                 }
2752                 /* Individual feature bits: what can host handle? */
2753                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
2754                         dev->hw_features |= NETIF_F_TSO;
2755                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
2756                         dev->hw_features |= NETIF_F_TSO6;
2757                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
2758                         dev->hw_features |= NETIF_F_TSO_ECN;
2759
2760                 dev->features |= NETIF_F_GSO_ROBUST;
2761
2762                 if (gso)
2763                         dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
2764                 /* (!csum && gso) case will be fixed by register_netdev() */
2765         }
2766         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
2767                 dev->features |= NETIF_F_RXCSUM;
2768
2769         dev->vlan_features = dev->features;
2770
2771         /* MTU range: 68 - 65535 */
2772         dev->min_mtu = MIN_MTU;
2773         dev->max_mtu = MAX_MTU;
2774
2775         /* Configuration may specify what MAC to use.  Otherwise random. */
2776         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
2777                 virtio_cread_bytes(vdev,
2778                                    offsetof(struct virtio_net_config, mac),
2779                                    dev->dev_addr, dev->addr_len);
2780         else
2781                 eth_hw_addr_random(dev);
2782
2783         /* Set up our device-specific information */
2784         vi = netdev_priv(dev);
2785         vi->dev = dev;
2786         vi->vdev = vdev;
2787         vdev->priv = vi;
2788
2789         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
2790
2791         /* If we can receive ANY GSO packets, we must allocate large ones. */
2792         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
2793             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
2794             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
2795             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
2796                 vi->big_packets = true;
2797
2798         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
2799                 vi->mergeable_rx_bufs = true;
2800
2801         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
2802             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2803                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2804         else
2805                 vi->hdr_len = sizeof(struct virtio_net_hdr);
2806
2807         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
2808             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
2809                 vi->any_header_sg = true;
2810
2811         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
2812                 vi->has_cvq = true;
2813
2814         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
2815                 mtu = virtio_cread16(vdev,
2816                                      offsetof(struct virtio_net_config,
2817                                               mtu));
2818                 if (mtu < dev->min_mtu) {
2819                         /* Should never trigger: MTU was previously validated
2820                          * in virtnet_validate.
2821                          */
2822                         dev_err(&vdev->dev, "device MTU appears to have changed "
2823                                 "it is now %d < %d", mtu, dev->min_mtu);
2824                         goto free;
2825                 }
2826
2827                 dev->mtu = mtu;
2828                 dev->max_mtu = mtu;
2829
2830                 /* TODO: size buffers correctly in this case. */
2831                 if (dev->mtu > ETH_DATA_LEN)
2832                         vi->big_packets = true;
2833         }
2834
2835         if (vi->any_header_sg)
2836                 dev->needed_headroom = vi->hdr_len;
2837
2838         /* Enable multiqueue by default */
2839         if (num_online_cpus() >= max_queue_pairs)
2840                 vi->curr_queue_pairs = max_queue_pairs;
2841         else
2842                 vi->curr_queue_pairs = num_online_cpus();
2843         vi->max_queue_pairs = max_queue_pairs;
2844
2845         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
2846         err = init_vqs(vi);
2847         if (err)
2848                 goto free;
2849
2850 #ifdef CONFIG_SYSFS
2851         if (vi->mergeable_rx_bufs)
2852                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
2853 #endif
2854         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
2855         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
2856
2857         virtnet_init_settings(dev);
2858
2859         err = register_netdev(dev);
2860         if (err) {
2861                 pr_debug("virtio_net: registering device failed\n");
2862                 goto free_vqs;
2863         }
2864
2865         virtio_device_ready(vdev);
2866
2867         err = virtnet_cpu_notif_add(vi);
2868         if (err) {
2869                 pr_debug("virtio_net: registering cpu notifier failed\n");
2870                 goto free_unregister_netdev;
2871         }
2872
2873         virtnet_set_queues(vi, vi->curr_queue_pairs);
2874
2875         /* Assume link up if device can't report link status,
2876            otherwise get link status from config. */
2877         netif_carrier_off(dev);
2878         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
2879                 schedule_work(&vi->config_work);
2880         } else {
2881                 vi->status = VIRTIO_NET_S_LINK_UP;
2882                 virtnet_update_settings(vi);
2883                 netif_carrier_on(dev);
2884         }
2885
2886         for (i = 0; i < ARRAY_SIZE(guest_offloads); i++)
2887                 if (virtio_has_feature(vi->vdev, guest_offloads[i]))
2888                         set_bit(guest_offloads[i], &vi->guest_offloads);
2889
2890         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
2891                  dev->name, max_queue_pairs);
2892
2893         return 0;
2894
2895 free_unregister_netdev:
2896         vi->vdev->config->reset(vdev);
2897
2898         unregister_netdev(dev);
2899 free_vqs:
2900         cancel_delayed_work_sync(&vi->refill);
2901         free_receive_page_frags(vi);
2902         virtnet_del_vqs(vi);
2903 free:
2904         free_netdev(dev);
2905         return err;
2906 }
2907
2908 static void remove_vq_common(struct virtnet_info *vi)
2909 {
2910         vi->vdev->config->reset(vi->vdev);
2911
2912         /* Free unused buffers in both send and recv, if any. */
2913         free_unused_bufs(vi);
2914
2915         free_receive_bufs(vi);
2916
2917         free_receive_page_frags(vi);
2918
2919         virtnet_del_vqs(vi);
2920 }
2921
2922 static void virtnet_remove(struct virtio_device *vdev)
2923 {
2924         struct virtnet_info *vi = vdev->priv;
2925
2926         virtnet_cpu_notif_remove(vi);
2927
2928         /* Make sure no work handler is accessing the device. */
2929         flush_work(&vi->config_work);
2930
2931         unregister_netdev(vi->dev);
2932
2933         remove_vq_common(vi);
2934
2935         free_netdev(vi->dev);
2936 }
2937
2938 static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
2939 {
2940         struct virtnet_info *vi = vdev->priv;
2941
2942         virtnet_cpu_notif_remove(vi);
2943         virtnet_freeze_down(vdev);
2944         remove_vq_common(vi);
2945
2946         return 0;
2947 }
2948
2949 static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
2950 {
2951         struct virtnet_info *vi = vdev->priv;
2952         int err;
2953
2954         err = virtnet_restore_up(vdev);
2955         if (err)
2956                 return err;
2957         virtnet_set_queues(vi, vi->curr_queue_pairs);
2958
2959         err = virtnet_cpu_notif_add(vi);
2960         if (err)
2961                 return err;
2962
2963         return 0;
2964 }
2965
2966 static struct virtio_device_id id_table[] = {
2967         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2968         { 0 },
2969 };
2970
2971 #define VIRTNET_FEATURES \
2972         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
2973         VIRTIO_NET_F_MAC, \
2974         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
2975         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
2976         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
2977         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
2978         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
2979         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
2980         VIRTIO_NET_F_CTRL_MAC_ADDR, \
2981         VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
2982         VIRTIO_NET_F_SPEED_DUPLEX
2983
2984 static unsigned int features[] = {
2985         VIRTNET_FEATURES,
2986 };
2987
2988 static unsigned int features_legacy[] = {
2989         VIRTNET_FEATURES,
2990         VIRTIO_NET_F_GSO,
2991         VIRTIO_F_ANY_LAYOUT,
2992 };
2993
2994 static struct virtio_driver virtio_net_driver = {
2995         .feature_table = features,
2996         .feature_table_size = ARRAY_SIZE(features),
2997         .feature_table_legacy = features_legacy,
2998         .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
2999         .driver.name =  KBUILD_MODNAME,
3000         .driver.owner = THIS_MODULE,
3001         .id_table =     id_table,
3002         .validate =     virtnet_validate,
3003         .probe =        virtnet_probe,
3004         .remove =       virtnet_remove,
3005         .config_changed = virtnet_config_changed,
3006 #ifdef CONFIG_PM_SLEEP
3007         .freeze =       virtnet_freeze,
3008         .restore =      virtnet_restore,
3009 #endif
3010 };
3011
3012 static __init int virtio_net_driver_init(void)
3013 {
3014         int ret;
3015
3016         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
3017                                       virtnet_cpu_online,
3018                                       virtnet_cpu_down_prep);
3019         if (ret < 0)
3020                 goto out;
3021         virtionet_online = ret;
3022         ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
3023                                       NULL, virtnet_cpu_dead);
3024         if (ret)
3025                 goto err_dead;
3026
3027         ret = register_virtio_driver(&virtio_net_driver);
3028         if (ret)
3029                 goto err_virtio;
3030         return 0;
3031 err_virtio:
3032         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3033 err_dead:
3034         cpuhp_remove_multi_state(virtionet_online);
3035 out:
3036         return ret;
3037 }
3038 module_init(virtio_net_driver_init);
3039
3040 static __exit void virtio_net_driver_exit(void)
3041 {
3042         unregister_virtio_driver(&virtio_net_driver);
3043         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
3044         cpuhp_remove_multi_state(virtionet_online);
3045 }
3046 module_exit(virtio_net_driver_exit);
3047
3048 MODULE_DEVICE_TABLE(virtio, id_table);
3049 MODULE_DESCRIPTION("Virtio network driver");
3050 MODULE_LICENSE("GPL");