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