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