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/scatterlist.h>
  26 #include <linux/if_vlan.h>
  27 #include <linux/slab.h>
  28 #include <linux/cpu.h>
  29 #include <linux/average.h>
  30 #include <net/busy_poll.h>
  31
  32 static int napi_weight = NAPI_POLL_WEIGHT;
  33 module_param(napi_weight, int, 0444);
  34
  35 static bool csum = true, gso = true;
  36 module_param(csum, bool, 0444);
  37 module_param(gso, bool, 0444);
  38
  39 /* FIXME: MTU in config. */
  40 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  41 #define GOOD_COPY_LEN   128
  42
  43 /* RX packet size EWMA. The average packet size is used to determine the packet
  44  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  45  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  46  * term, transient changes in packet size.
  47  */
  48 DECLARE_EWMA(pkt_len, 1, 64)
  49
  50 /* With mergeable buffers we align buffer address and use the low bits to
  51  * encode its true size. Buffer size is up to 1 page so we need to align to
  52  * square root of page size to ensure we reserve enough bits to encode the true
  53  * size.
  54  */
  55 #define MERGEABLE_BUFFER_MIN_ALIGN_SHIFT ((PAGE_SHIFT + 1) / 2)
  56
  57 /* Minimum alignment for mergeable packet buffers. */
  58 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, \
  59                                    1 << MERGEABLE_BUFFER_MIN_ALIGN_SHIFT)
  60
  61 #define VIRTNET_DRIVER_VERSION "1.0.0"
  62
  63 struct virtnet_stats {
  64         struct u64_stats_sync tx_syncp;
  65         struct u64_stats_sync rx_syncp;
  66         u64 tx_bytes;
  67         u64 tx_packets;
  68
  69         u64 rx_bytes;
  70         u64 rx_packets;
  71 };
  72
  73 /* Internal representation of a send virtqueue */
  74 struct send_queue {
  75         /* Virtqueue associated with this send _queue */
  76         struct virtqueue *vq;
  77
  78         /* TX: fragments + linear part + virtio header */
  79         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  80
  81         /* Name of the send queue: output.$index */
  82         char name[40];
  83 };
  84
  85 /* Internal representation of a receive virtqueue */
  86 struct receive_queue {
  87         /* Virtqueue associated with this receive_queue */
  88         struct virtqueue *vq;
  89
  90         struct napi_struct napi;
  91
  92         /* Chain pages by the private ptr. */
  93         struct page *pages;
  94
  95         /* Average packet length for mergeable receive buffers. */
  96         struct ewma_pkt_len mrg_avg_pkt_len;
  97
  98         /* Page frag for packet buffer allocation. */
  99         struct page_frag alloc_frag;
 100
 101         /* RX: fragments + linear part + virtio header */
 102         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 103
 104         /* Name of this receive queue: input.$index */
 105         char name[40];
 106 };
 107
 108 struct virtnet_info {
 109         struct virtio_device *vdev;
 110         struct virtqueue *cvq;
 111         struct net_device *dev;
 112         struct send_queue *sq;
 113         struct receive_queue *rq;
 114         unsigned int status;
 115
 116         /* Max # of queue pairs supported by the device */
 117         u16 max_queue_pairs;
 118
 119         /* # of queue pairs currently used by the driver */
 120         u16 curr_queue_pairs;
 121
 122         /* I like... big packets and I cannot lie! */
 123         bool big_packets;
 124
 125         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 126         bool mergeable_rx_bufs;
 127
 128         /* Has control virtqueue */
 129         bool has_cvq;
 130
 131         /* Host can handle any s/g split between our header and packet data */
 132         bool any_header_sg;
 133
 134         /* Packet virtio header size */
 135         u8 hdr_len;
 136
 137         /* Active statistics */
 138         struct virtnet_stats __percpu *stats;
 139
 140         /* Work struct for refilling if we run low on memory. */
 141         struct delayed_work refill;
 142
 143         /* Work struct for config space updates */
 144         struct work_struct config_work;
 145
 146         /* Does the affinity hint is set for virtqueues? */
 147         bool affinity_hint_set;
 148
 149         /* CPU hotplug instances for online & dead */
 150         struct hlist_node node;
 151         struct hlist_node node_dead;
 152
 153         /* Control VQ buffers: protected by the rtnl lock */
 154         struct virtio_net_ctrl_hdr ctrl_hdr;
 155         virtio_net_ctrl_ack ctrl_status;
 156         struct virtio_net_ctrl_mq ctrl_mq;
 157         u8 ctrl_promisc;
 158         u8 ctrl_allmulti;
 159         u16 ctrl_vid;
 160
 161         /* Ethtool settings */
 162         u8 duplex;
 163         u32 speed;
 164 };
 165
 166 struct padded_vnet_hdr {
 167         struct virtio_net_hdr_mrg_rxbuf hdr;
 168         /*
 169          * hdr is in a separate sg buffer, and data sg buffer shares same page
 170          * with this header sg. This padding makes next sg 16 byte aligned
 171          * after the header.
 172          */
 173         char padding[4];
 174 };
 175
 176 /* Converting between virtqueue no. and kernel tx/rx queue no.
 177  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 178  */
 179 static int vq2txq(struct virtqueue *vq)
 180 {
 181         return (vq->index - 1) / 2;
 182 }
 183
 184 static int txq2vq(int txq)
 185 {
 186         return txq * 2 + 1;
 187 }
 188
 189 static int vq2rxq(struct virtqueue *vq)
 190 {
 191         return vq->index / 2;
 192 }
 193
 194 static int rxq2vq(int rxq)
 195 {
 196         return rxq * 2;
 197 }
 198
 199 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 200 {
 201         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 202 }
 203
 204 /*
 205  * private is used to chain pages for big packets, put the whole
 206  * most recent used list in the beginning for reuse
 207  */
 208 static void give_pages(struct receive_queue *rq, struct page *page)
 209 {
 210         struct page *end;
 211
 212         /* Find end of list, sew whole thing into vi->rq.pages. */
 213         for (end = page; end->private; end = (struct page *)end->private);
 214         end->private = (unsigned long)rq->pages;
 215         rq->pages = page;
 216 }
 217
 218 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 219 {
 220         struct page *p = rq->pages;
 221
 222         if (p) {
 223                 rq->pages = (struct page *)p->private;
 224                 /* clear private here, it is used to chain pages */
 225                 p->private = 0;
 226         } else
 227                 p = alloc_page(gfp_mask);
 228         return p;
 229 }
 230
 231 static void skb_xmit_done(struct virtqueue *vq)
 232 {
 233         struct virtnet_info *vi = vq->vdev->priv;
 234
 235         /* Suppress further interrupts. */
 236         virtqueue_disable_cb(vq);
 237
 238         /* We were probably waiting for more output buffers. */
 239         netif_wake_subqueue(vi->dev, vq2txq(vq));
 240 }
 241
 242 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
 243 {
 244         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
 245         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
 246 }
 247
 248 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
 249 {
 250         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
 251
 252 }
 253
 254 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 255 {
 256         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
 257         return (unsigned long)buf | (size - 1);
 258 }
 259
 260 /* Called from bottom half context */
 261 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 262                                    struct receive_queue *rq,
 263                                    struct page *page, unsigned int offset,
 264                                    unsigned int len, unsigned int truesize)
 265 {
 266         struct sk_buff *skb;
 267         struct virtio_net_hdr_mrg_rxbuf *hdr;
 268         unsigned int copy, hdr_len, hdr_padded_len;
 269         char *p;
 270
 271         p = page_address(page) + offset;
 272
 273         /* copy small packet so we can reuse these pages for small data */
 274         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 275         if (unlikely(!skb))
 276                 return NULL;
 277
 278         hdr = skb_vnet_hdr(skb);
 279
 280         hdr_len = vi->hdr_len;
 281         if (vi->mergeable_rx_bufs)
 282                 hdr_padded_len = sizeof *hdr;
 283         else
 284                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 285
 286         memcpy(hdr, p, hdr_len);
 287
 288         len -= hdr_len;
 289         offset += hdr_padded_len;
 290         p += hdr_padded_len;
 291
 292         copy = len;
 293         if (copy > skb_tailroom(skb))
 294                 copy = skb_tailroom(skb);
 295         memcpy(skb_put(skb, copy), p, copy);
 296
 297         len -= copy;
 298         offset += copy;
 299
 300         if (vi->mergeable_rx_bufs) {
 301                 if (len)
 302                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 303                 else
 304                         put_page(page);
 305                 return skb;
 306         }
 307
 308         /*
 309          * Verify that we can indeed put this data into a skb.
 310          * This is here to handle cases when the device erroneously
 311          * tries to receive more than is possible. This is usually
 312          * the case of a broken device.
 313          */
 314         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 315                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 316                 dev_kfree_skb(skb);
 317                 return NULL;
 318         }
 319         BUG_ON(offset >= PAGE_SIZE);
 320         while (len) {
 321                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 322                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 323                                 frag_size, truesize);
 324                 len -= frag_size;
 325                 page = (struct page *)page->private;
 326                 offset = 0;
 327         }
 328
 329         if (page)
 330                 give_pages(rq, page);
 331
 332         return skb;
 333 }
 334
 335 static struct sk_buff *receive_small(struct virtnet_info *vi, void *buf, unsigned int len)
 336 {
 337         struct sk_buff * skb = buf;
 338
 339         len -= vi->hdr_len;
 340         skb_trim(skb, len);
 341
 342         return skb;
 343 }
 344
 345 static struct sk_buff *receive_big(struct net_device *dev,
 346                                    struct virtnet_info *vi,
 347                                    struct receive_queue *rq,
 348                                    void *buf,
 349                                    unsigned int len)
 350 {
 351         struct page *page = buf;
 352         struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 353
 354         if (unlikely(!skb))
 355                 goto err;
 356
 357         return skb;
 358
 359 err:
 360         dev->stats.rx_dropped++;
 361         give_pages(rq, page);
 362         return NULL;
 363 }
 364
 365 static struct sk_buff *receive_mergeable(struct net_device *dev,
 366                                          struct virtnet_info *vi,
 367                                          struct receive_queue *rq,
 368                                          unsigned long ctx,
 369                                          unsigned int len)
 370 {
 371         void *buf = mergeable_ctx_to_buf_address(ctx);
 372         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 373         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 374         struct page *page = virt_to_head_page(buf);
 375         int offset = buf - page_address(page);
 376         unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 377
 378         struct sk_buff *head_skb = page_to_skb(vi, rq, page, offset, len,
 379                                                truesize);
 380         struct sk_buff *curr_skb = head_skb;
 381
 382         if (unlikely(!curr_skb))
 383                 goto err_skb;
 384         while (--num_buf) {
 385                 int num_skb_frags;
 386
 387                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 388                 if (unlikely(!ctx)) {
 389                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 390                                  dev->name, num_buf,
 391                                  virtio16_to_cpu(vi->vdev,
 392                                                  hdr->num_buffers));
 393                         dev->stats.rx_length_errors++;
 394                         goto err_buf;
 395                 }
 396
 397                 buf = mergeable_ctx_to_buf_address(ctx);
 398                 page = virt_to_head_page(buf);
 399
 400                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 401                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 402                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 403
 404                         if (unlikely(!nskb))
 405                                 goto err_skb;
 406                         if (curr_skb == head_skb)
 407                                 skb_shinfo(curr_skb)->frag_list = nskb;
 408                         else
 409                                 curr_skb->next = nskb;
 410                         curr_skb = nskb;
 411                         head_skb->truesize += nskb->truesize;
 412                         num_skb_frags = 0;
 413                 }
 414                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 415                 if (curr_skb != head_skb) {
 416                         head_skb->data_len += len;
 417                         head_skb->len += len;
 418                         head_skb->truesize += truesize;
 419                 }
 420                 offset = buf - page_address(page);
 421                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 422                         put_page(page);
 423                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 424                                              len, truesize);
 425                 } else {
 426                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 427                                         offset, len, truesize);
 428                 }
 429         }
 430
 431         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
 432         return head_skb;
 433
 434 err_skb:
 435         put_page(page);
 436         while (--num_buf) {
 437                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 438                 if (unlikely(!ctx)) {
 439                         pr_debug("%s: rx error: %d buffers missing\n",
 440                                  dev->name, num_buf);
 441                         dev->stats.rx_length_errors++;
 442                         break;
 443                 }
 444                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
 445                 put_page(page);
 446         }
 447 err_buf:
 448         dev->stats.rx_dropped++;
 449         dev_kfree_skb(head_skb);
 450         return NULL;
 451 }
 452
 453 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 454                         void *buf, unsigned int len)
 455 {
 456         struct net_device *dev = vi->dev;
 457         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 458         struct sk_buff *skb;
 459         struct virtio_net_hdr_mrg_rxbuf *hdr;
 460
 461         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 462                 pr_debug("%s: short packet %i\n", dev->name, len);
 463                 dev->stats.rx_length_errors++;
 464                 if (vi->mergeable_rx_bufs) {
 465                         unsigned long ctx = (unsigned long)buf;
 466                         void *base = mergeable_ctx_to_buf_address(ctx);
 467                         put_page(virt_to_head_page(base));
 468                 } else if (vi->big_packets) {
 469                         give_pages(rq, buf);
 470                 } else {
 471                         dev_kfree_skb(buf);
 472                 }
 473                 return;
 474         }
 475
 476         if (vi->mergeable_rx_bufs)
 477                 skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len);
 478         else if (vi->big_packets)
 479                 skb = receive_big(dev, vi, rq, buf, len);
 480         else
 481                 skb = receive_small(vi, buf, len);
 482
 483         if (unlikely(!skb))
 484                 return;
 485
 486         hdr = skb_vnet_hdr(skb);
 487
 488         u64_stats_update_begin(&stats->rx_syncp);
 489         stats->rx_bytes += skb->len;
 490         stats->rx_packets++;
 491         u64_stats_update_end(&stats->rx_syncp);
 492
 493         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
 494                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 495
 496         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
 497                                   virtio_is_little_endian(vi->vdev))) {
 498                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
 499                                      dev->name, hdr->hdr.gso_type,
 500                                      hdr->hdr.gso_size);
 501                 goto frame_err;
 502         }
 503
 504         skb->protocol = eth_type_trans(skb, dev);
 505         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 506                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 507
 508         napi_gro_receive(&rq->napi, skb);
 509         return;
 510
 511 frame_err:
 512         dev->stats.rx_frame_errors++;
 513         dev_kfree_skb(skb);
 514 }
 515
 516 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 517                              gfp_t gfp)
 518 {
 519         struct sk_buff *skb;
 520         struct virtio_net_hdr_mrg_rxbuf *hdr;
 521         int err;
 522
 523         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 524         if (unlikely(!skb))
 525                 return -ENOMEM;
 526
 527         skb_put(skb, GOOD_PACKET_LEN);
 528
 529         hdr = skb_vnet_hdr(skb);
 530         sg_init_table(rq->sg, 2);
 531         sg_set_buf(rq->sg, hdr, vi->hdr_len);
 532
 533         err = skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 534         if (unlikely(err < 0)) {
 535                 dev_kfree_skb(skb);
 536                 return err;
 537         }
 538
 539         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 540         if (err < 0)
 541                 dev_kfree_skb(skb);
 542
 543         return err;
 544 }
 545
 546 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
 547                            gfp_t gfp)
 548 {
 549         struct page *first, *list = NULL;
 550         char *p;
 551         int i, err, offset;
 552
 553         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 554
 555         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 556         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 557                 first = get_a_page(rq, gfp);
 558                 if (!first) {
 559                         if (list)
 560                                 give_pages(rq, list);
 561                         return -ENOMEM;
 562                 }
 563                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 564
 565                 /* chain new page in list head to match sg */
 566                 first->private = (unsigned long)list;
 567                 list = first;
 568         }
 569
 570         first = get_a_page(rq, gfp);
 571         if (!first) {
 572                 give_pages(rq, list);
 573                 return -ENOMEM;
 574         }
 575         p = page_address(first);
 576
 577         /* rq->sg[0], rq->sg[1] share the same page */
 578         /* a separated rq->sg[0] for header - required in case !any_header_sg */
 579         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
 580
 581         /* rq->sg[1] for data packet, from offset */
 582         offset = sizeof(struct padded_vnet_hdr);
 583         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 584
 585         /* chain first in list head */
 586         first->private = (unsigned long)list;
 587         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 588                                   first, gfp);
 589         if (err < 0)
 590                 give_pages(rq, first);
 591
 592         return err;
 593 }
 594
 595 static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
 596 {
 597         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 598         unsigned int len;
 599
 600         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
 601                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 602         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 603 }
 604
 605 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 606 {
 607         struct page_frag *alloc_frag = &rq->alloc_frag;
 608         char *buf;
 609         unsigned long ctx;
 610         int err;
 611         unsigned int len, hole;
 612
 613         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 614         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 615                 return -ENOMEM;
 616
 617         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 618         ctx = mergeable_buf_to_ctx(buf, len);
 619         get_page(alloc_frag->page);
 620         alloc_frag->offset += len;
 621         hole = alloc_frag->size - alloc_frag->offset;
 622         if (hole < len) {
 623                 /* To avoid internal fragmentation, if there is very likely not
 624                  * enough space for another buffer, add the remaining space to
 625                  * the current buffer. This extra space is not included in
 626                  * the truesize stored in ctx.
 627                  */
 628                 len += hole;
 629                 alloc_frag->offset += hole;
 630         }
 631
 632         sg_init_one(rq->sg, buf, len);
 633         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 634         if (err < 0)
 635                 put_page(virt_to_head_page(buf));
 636
 637         return err;
 638 }
 639
 640 /*
 641  * Returns false if we couldn't fill entirely (OOM).
 642  *
 643  * Normally run in the receive path, but can also be run from ndo_open
 644  * before we're receiving packets, or from refill_work which is
 645  * careful to disable receiving (using napi_disable).
 646  */
 647 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
 648                           gfp_t gfp)
 649 {
 650         int err;
 651         bool oom;
 652
 653         gfp |= __GFP_COLD;
 654         do {
 655                 if (vi->mergeable_rx_bufs)
 656                         err = add_recvbuf_mergeable(rq, gfp);
 657                 else if (vi->big_packets)
 658                         err = add_recvbuf_big(vi, rq, gfp);
 659                 else
 660                         err = add_recvbuf_small(vi, rq, gfp);
 661
 662                 oom = err == -ENOMEM;
 663                 if (err)
 664                         break;
 665         } while (rq->vq->num_free);
 666         virtqueue_kick(rq->vq);
 667         return !oom;
 668 }
 669
 670 static void skb_recv_done(struct virtqueue *rvq)
 671 {
 672         struct virtnet_info *vi = rvq->vdev->priv;
 673         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 674
 675         /* Schedule NAPI, Suppress further interrupts if successful. */
 676         if (napi_schedule_prep(&rq->napi)) {
 677                 virtqueue_disable_cb(rvq);
 678                 __napi_schedule(&rq->napi);
 679         }
 680 }
 681
 682 static void virtnet_napi_enable(struct receive_queue *rq)
 683 {
 684         napi_enable(&rq->napi);
 685
 686         /* If all buffers were filled by other side before we napi_enabled, we
 687          * won't get another interrupt, so process any outstanding packets
 688          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 689          * We synchronize against interrupts via NAPI_STATE_SCHED */
 690         if (napi_schedule_prep(&rq->napi)) {
 691                 virtqueue_disable_cb(rq->vq);
 692                 local_bh_disable();
 693                 __napi_schedule(&rq->napi);
 694                 local_bh_enable();
 695         }
 696 }
 697
 698 static void refill_work(struct work_struct *work)
 699 {
 700         struct virtnet_info *vi =
 701                 container_of(work, struct virtnet_info, refill.work);
 702         bool still_empty;
 703         int i;
 704
 705         for (i = 0; i < vi->curr_queue_pairs; i++) {
 706                 struct receive_queue *rq = &vi->rq[i];
 707
 708                 napi_disable(&rq->napi);
 709                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 710                 virtnet_napi_enable(rq);
 711
 712                 /* In theory, this can happen: if we don't get any buffers in
 713                  * we will *never* try to fill again.
 714                  */
 715                 if (still_empty)
 716                         schedule_delayed_work(&vi->refill, HZ/2);
 717         }
 718 }
 719
 720 static int virtnet_receive(struct receive_queue *rq, int budget)
 721 {
 722         struct virtnet_info *vi = rq->vq->vdev->priv;
 723         unsigned int len, received = 0;
 724         void *buf;
 725
 726         while (received < budget &&
 727                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 728                 receive_buf(vi, rq, buf, len);
 729                 received++;
 730         }
 731
 732         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 733                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
 734                         schedule_delayed_work(&vi->refill, 0);
 735         }
 736
 737         return received;
 738 }
 739
 740 static int virtnet_poll(struct napi_struct *napi, int budget)
 741 {
 742         struct receive_queue *rq =
 743                 container_of(napi, struct receive_queue, napi);
 744         unsigned int r, received;
 745
 746         received = virtnet_receive(rq, budget);
 747
 748         /* Out of packets? */
 749         if (received < budget) {
 750                 r = virtqueue_enable_cb_prepare(rq->vq);
 751                 napi_complete_done(napi, received);
 752                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 753                     napi_schedule_prep(napi)) {
 754                         virtqueue_disable_cb(rq->vq);
 755                         __napi_schedule(napi);
 756                 }
 757         }
 758
 759         return received;
 760 }
 761
 762 #ifdef CONFIG_NET_RX_BUSY_POLL
 763 /* must be called with local_bh_disable()d */
 764 static int virtnet_busy_poll(struct napi_struct *napi)
 765 {
 766         struct receive_queue *rq =
 767                 container_of(napi, struct receive_queue, napi);
 768         struct virtnet_info *vi = rq->vq->vdev->priv;
 769         int r, received = 0, budget = 4;
 770
 771         if (!(vi->status & VIRTIO_NET_S_LINK_UP))
 772                 return LL_FLUSH_FAILED;
 773
 774         if (!napi_schedule_prep(napi))
 775                 return LL_FLUSH_BUSY;
 776
 777         virtqueue_disable_cb(rq->vq);
 778
 779 again:
 780         received += virtnet_receive(rq, budget);
 781
 782         r = virtqueue_enable_cb_prepare(rq->vq);
 783         clear_bit(NAPI_STATE_SCHED, &napi->state);
 784         if (unlikely(virtqueue_poll(rq->vq, r)) &&
 785             napi_schedule_prep(napi)) {
 786                 virtqueue_disable_cb(rq->vq);
 787                 if (received < budget) {
 788                         budget -= received;
 789                         goto again;
 790                 } else {
 791                         __napi_schedule(napi);
 792                 }
 793         }
 794
 795         return received;
 796 }
 797 #endif  /* CONFIG_NET_RX_BUSY_POLL */
 798
 799 static int virtnet_open(struct net_device *dev)
 800 {
 801         struct virtnet_info *vi = netdev_priv(dev);
 802         int i;
 803
 804         for (i = 0; i < vi->max_queue_pairs; i++) {
 805                 if (i < vi->curr_queue_pairs)
 806                         /* Make sure we have some buffers: if oom use wq. */
 807                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
 808                                 schedule_delayed_work(&vi->refill, 0);
 809                 virtnet_napi_enable(&vi->rq[i]);
 810         }
 811
 812         return 0;
 813 }
 814
 815 static void free_old_xmit_skbs(struct send_queue *sq)
 816 {
 817         struct sk_buff *skb;
 818         unsigned int len;
 819         struct virtnet_info *vi = sq->vq->vdev->priv;
 820         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 821
 822         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 823                 pr_debug("Sent skb %p\n", skb);
 824
 825                 u64_stats_update_begin(&stats->tx_syncp);
 826                 stats->tx_bytes += skb->len;
 827                 stats->tx_packets++;
 828                 u64_stats_update_end(&stats->tx_syncp);
 829
 830                 dev_kfree_skb_any(skb);
 831         }
 832 }
 833
 834 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 835 {
 836         struct virtio_net_hdr_mrg_rxbuf *hdr;
 837         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 838         struct virtnet_info *vi = sq->vq->vdev->priv;
 839         int num_sg;
 840         unsigned hdr_len = vi->hdr_len;
 841         bool can_push;
 842
 843         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 844
 845         can_push = vi->any_header_sg &&
 846                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 847                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 848         /* Even if we can, don't push here yet as this would skew
 849          * csum_start offset below. */
 850         if (can_push)
 851                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
 852         else
 853                 hdr = skb_vnet_hdr(skb);
 854
 855         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
 856                                     virtio_is_little_endian(vi->vdev), false))
 857                 BUG();
 858
 859         if (vi->mergeable_rx_bufs)
 860                 hdr->num_buffers = 0;
 861
 862         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
 863         if (can_push) {
 864                 __skb_push(skb, hdr_len);
 865                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 866                 if (unlikely(num_sg < 0))
 867                         return num_sg;
 868                 /* Pull header back to avoid skew in tx bytes calculations. */
 869                 __skb_pull(skb, hdr_len);
 870         } else {
 871                 sg_set_buf(sq->sg, hdr, hdr_len);
 872                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
 873                 if (unlikely(num_sg < 0))
 874                         return num_sg;
 875                 num_sg++;
 876         }
 877         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 878 }
 879
 880 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 881 {
 882         struct virtnet_info *vi = netdev_priv(dev);
 883         int qnum = skb_get_queue_mapping(skb);
 884         struct send_queue *sq = &vi->sq[qnum];
 885         int err;
 886         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
 887         bool kick = !skb->xmit_more;
 888
 889         /* Free up any pending old buffers before queueing new ones. */
 890         free_old_xmit_skbs(sq);
 891
 892         /* timestamp packet in software */
 893         skb_tx_timestamp(skb);
 894
 895         /* Try to transmit */
 896         err = xmit_skb(sq, skb);
 897
 898         /* This should not happen! */
 899         if (unlikely(err)) {
 900                 dev->stats.tx_fifo_errors++;
 901                 if (net_ratelimit())
 902                         dev_warn(&dev->dev,
 903                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 904                 dev->stats.tx_dropped++;
 905                 dev_kfree_skb_any(skb);
 906                 return NETDEV_TX_OK;
 907         }
 908
 909         /* Don't wait up for transmitted skbs to be freed. */
 910         skb_orphan(skb);
 911         nf_reset(skb);
 912
 913         /* If running out of space, stop queue to avoid getting packets that we
 914          * are then unable to transmit.
 915          * An alternative would be to force queuing layer to requeue the skb by
 916          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
 917          * returned in a normal path of operation: it means that driver is not
 918          * maintaining the TX queue stop/start state properly, and causes
 919          * the stack to do a non-trivial amount of useless work.
 920          * Since most packets only take 1 or 2 ring slots, stopping the queue
 921          * early means 16 slots are typically wasted.
 922          */
 923         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 924                 netif_stop_subqueue(dev, qnum);
 925                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 926                         /* More just got used, free them then recheck. */
 927                         free_old_xmit_skbs(sq);
 928                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 929                                 netif_start_subqueue(dev, qnum);
 930                                 virtqueue_disable_cb(sq->vq);
 931                         }
 932                 }
 933         }
 934
 935         if (kick || netif_xmit_stopped(txq))
 936                 virtqueue_kick(sq->vq);
 937
 938         return NETDEV_TX_OK;
 939 }
 940
 941 /*
 942  * Send command via the control virtqueue and check status.  Commands
 943  * supported by the hypervisor, as indicated by feature bits, should
 944  * never fail unless improperly formatted.
 945  */
 946 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 947                                  struct scatterlist *out)
 948 {
 949         struct scatterlist *sgs[4], hdr, stat;
 950         unsigned out_num = 0, tmp;
 951
 952         /* Caller should know better */
 953         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 954
 955         vi->ctrl_status = ~0;
 956         vi->ctrl_hdr.class = class;
 957         vi->ctrl_hdr.cmd = cmd;
 958         /* Add header */
 959         sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
 960         sgs[out_num++] = &hdr;
 961
 962         if (out)
 963                 sgs[out_num++] = out;
 964
 965         /* Add return status. */
 966         sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
 967         sgs[out_num] = &stat;
 968
 969         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
 970         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
 971
 972         if (unlikely(!virtqueue_kick(vi->cvq)))
 973                 return vi->ctrl_status == VIRTIO_NET_OK;
 974
 975         /* Spin for a response, the kick causes an ioport write, trapping
 976          * into the hypervisor, so the request should be handled immediately.
 977          */
 978         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 979                !virtqueue_is_broken(vi->cvq))
 980                 cpu_relax();
 981
 982         return vi->ctrl_status == VIRTIO_NET_OK;
 983 }
 984
 985 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 986 {
 987         struct virtnet_info *vi = netdev_priv(dev);
 988         struct virtio_device *vdev = vi->vdev;
 989         int ret;
 990         struct sockaddr *addr;
 991         struct scatterlist sg;
 992
 993         addr = kmalloc(sizeof(*addr), GFP_KERNEL);
 994         if (!addr)
 995                 return -ENOMEM;
 996         memcpy(addr, p, sizeof(*addr));
 997
 998         ret = eth_prepare_mac_addr_change(dev, addr);
 999         if (ret)
1000                 goto out;
1001
1002         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1003                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1004                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1005                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1006                         dev_warn(&vdev->dev,
1007                                  "Failed to set mac address by vq command.\n");
1008                         ret = -EINVAL;
1009                         goto out;
1010                 }
1011         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1012                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1013                 unsigned int i;
1014
1015                 /* Naturally, this has an atomicity problem. */
1016                 for (i = 0; i < dev->addr_len; i++)
1017                         virtio_cwrite8(vdev,
1018                                        offsetof(struct virtio_net_config, mac) +
1019                                        i, addr->sa_data[i]);
1020         }
1021
1022         eth_commit_mac_addr_change(dev, p);
1023         ret = 0;
1024
1025 out:
1026         kfree(addr);
1027         return ret;
1028 }
1029
1030 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1031                                                struct rtnl_link_stats64 *tot)
1032 {
1033         struct virtnet_info *vi = netdev_priv(dev);
1034         int cpu;
1035         unsigned int start;
1036
1037         for_each_possible_cpu(cpu) {
1038                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1039                 u64 tpackets, tbytes, rpackets, rbytes;
1040
1041                 do {
1042                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1043                         tpackets = stats->tx_packets;
1044                         tbytes   = stats->tx_bytes;
1045                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1046
1047                 do {
1048                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1049                         rpackets = stats->rx_packets;
1050                         rbytes   = stats->rx_bytes;
1051                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1052
1053                 tot->rx_packets += rpackets;
1054                 tot->tx_packets += tpackets;
1055                 tot->rx_bytes   += rbytes;
1056                 tot->tx_bytes   += tbytes;
1057         }
1058
1059         tot->tx_dropped = dev->stats.tx_dropped;
1060         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1061         tot->rx_dropped = dev->stats.rx_dropped;
1062         tot->rx_length_errors = dev->stats.rx_length_errors;
1063         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1064
1065         return tot;
1066 }
1067
1068 #ifdef CONFIG_NET_POLL_CONTROLLER
1069 static void virtnet_netpoll(struct net_device *dev)
1070 {
1071         struct virtnet_info *vi = netdev_priv(dev);
1072         int i;
1073
1074         for (i = 0; i < vi->curr_queue_pairs; i++)
1075                 napi_schedule(&vi->rq[i].napi);
1076 }
1077 #endif
1078
1079 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1080 {
1081         rtnl_lock();
1082         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1083                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1084                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1085         rtnl_unlock();
1086 }
1087
1088 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1089 {
1090         struct scatterlist sg;
1091         struct net_device *dev = vi->dev;
1092
1093         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1094                 return 0;
1095
1096         vi->ctrl_mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1097         sg_init_one(&sg, &vi->ctrl_mq, sizeof(vi->ctrl_mq));
1098
1099         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1100                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1101                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1102                          queue_pairs);
1103                 return -EINVAL;
1104         } else {
1105                 vi->curr_queue_pairs = queue_pairs;
1106                 /* virtnet_open() will refill when device is going to up. */
1107                 if (dev->flags & IFF_UP)
1108                         schedule_delayed_work(&vi->refill, 0);
1109         }
1110
1111         return 0;
1112 }
1113
1114 static int virtnet_close(struct net_device *dev)
1115 {
1116         struct virtnet_info *vi = netdev_priv(dev);
1117         int i;
1118
1119         /* Make sure refill_work doesn't re-enable napi! */
1120         cancel_delayed_work_sync(&vi->refill);
1121
1122         for (i = 0; i < vi->max_queue_pairs; i++)
1123                 napi_disable(&vi->rq[i].napi);
1124
1125         return 0;
1126 }
1127
1128 static void virtnet_set_rx_mode(struct net_device *dev)
1129 {
1130         struct virtnet_info *vi = netdev_priv(dev);
1131         struct scatterlist sg[2];
1132         struct virtio_net_ctrl_mac *mac_data;
1133         struct netdev_hw_addr *ha;
1134         int uc_count;
1135         int mc_count;
1136         void *buf;
1137         int i;
1138
1139         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1140         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1141                 return;
1142
1143         vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1144         vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1145
1146         sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1147
1148         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1149                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1150                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1151                          vi->ctrl_promisc ? "en" : "dis");
1152
1153         sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1154
1155         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1156                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1157                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1158                          vi->ctrl_allmulti ? "en" : "dis");
1159
1160         uc_count = netdev_uc_count(dev);
1161         mc_count = netdev_mc_count(dev);
1162         /* MAC filter - use one buffer for both lists */
1163         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1164                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1165         mac_data = buf;
1166         if (!buf)
1167                 return;
1168
1169         sg_init_table(sg, 2);
1170
1171         /* Store the unicast list and count in the front of the buffer */
1172         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1173         i = 0;
1174         netdev_for_each_uc_addr(ha, dev)
1175                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1176
1177         sg_set_buf(&sg[0], mac_data,
1178                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1179
1180         /* multicast list and count fill the end */
1181         mac_data = (void *)&mac_data->macs[uc_count][0];
1182
1183         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1184         i = 0;
1185         netdev_for_each_mc_addr(ha, dev)
1186                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1187
1188         sg_set_buf(&sg[1], mac_data,
1189                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1190
1191         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1192                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1193                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1194
1195         kfree(buf);
1196 }
1197
1198 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1199                                    __be16 proto, u16 vid)
1200 {
1201         struct virtnet_info *vi = netdev_priv(dev);
1202         struct scatterlist sg;
1203
1204         vi->ctrl_vid = vid;
1205         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1206
1207         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1208                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1209                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1210         return 0;
1211 }
1212
1213 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1214                                     __be16 proto, u16 vid)
1215 {
1216         struct virtnet_info *vi = netdev_priv(dev);
1217         struct scatterlist sg;
1218
1219         vi->ctrl_vid = vid;
1220         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1221
1222         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1223                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1224                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1225         return 0;
1226 }
1227
1228 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1229 {
1230         int i;
1231
1232         if (vi->affinity_hint_set) {
1233                 for (i = 0; i < vi->max_queue_pairs; i++) {
1234                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1235                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1236                 }
1237
1238                 vi->affinity_hint_set = false;
1239         }
1240 }
1241
1242 static void virtnet_set_affinity(struct virtnet_info *vi)
1243 {
1244         int i;
1245         int cpu;
1246
1247         /* In multiqueue mode, when the number of cpu is equal to the number of
1248          * queue pairs, we let the queue pairs to be private to one cpu by
1249          * setting the affinity hint to eliminate the contention.
1250          */
1251         if (vi->curr_queue_pairs == 1 ||
1252             vi->max_queue_pairs != num_online_cpus()) {
1253                 virtnet_clean_affinity(vi, -1);
1254                 return;
1255         }
1256
1257         i = 0;
1258         for_each_online_cpu(cpu) {
1259                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1260                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1261                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1262                 i++;
1263         }
1264
1265         vi->affinity_hint_set = true;
1266 }
1267
1268 static int virtnet_cpu_online(unsigned int cpu, struct hlist_node *node)
1269 {
1270         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1271                                                    node);
1272         virtnet_set_affinity(vi);
1273         return 0;
1274 }
1275
1276 static int virtnet_cpu_dead(unsigned int cpu, struct hlist_node *node)
1277 {
1278         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1279                                                    node_dead);
1280         virtnet_set_affinity(vi);
1281         return 0;
1282 }
1283
1284 static int virtnet_cpu_down_prep(unsigned int cpu, struct hlist_node *node)
1285 {
1286         struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
1287                                                    node);
1288
1289         virtnet_clean_affinity(vi, cpu);
1290         return 0;
1291 }
1292
1293 static enum cpuhp_state virtionet_online;
1294
1295 static int virtnet_cpu_notif_add(struct virtnet_info *vi)
1296 {
1297         int ret;
1298
1299         ret = cpuhp_state_add_instance_nocalls(virtionet_online, &vi->node);
1300         if (ret)
1301                 return ret;
1302         ret = cpuhp_state_add_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1303                                                &vi->node_dead);
1304         if (!ret)
1305                 return ret;
1306         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1307         return ret;
1308 }
1309
1310 static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
1311 {
1312         cpuhp_state_remove_instance_nocalls(virtionet_online, &vi->node);
1313         cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_NET_DEAD,
1314                                             &vi->node_dead);
1315 }
1316
1317 static void virtnet_get_ringparam(struct net_device *dev,
1318                                 struct ethtool_ringparam *ring)
1319 {
1320         struct virtnet_info *vi = netdev_priv(dev);
1321
1322         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1323         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1324         ring->rx_pending = ring->rx_max_pending;
1325         ring->tx_pending = ring->tx_max_pending;
1326 }
1327
1328
1329 static void virtnet_get_drvinfo(struct net_device *dev,
1330                                 struct ethtool_drvinfo *info)
1331 {
1332         struct virtnet_info *vi = netdev_priv(dev);
1333         struct virtio_device *vdev = vi->vdev;
1334
1335         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1336         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1337         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1338
1339 }
1340
1341 /* TODO: Eliminate OOO packets during switching */
1342 static int virtnet_set_channels(struct net_device *dev,
1343                                 struct ethtool_channels *channels)
1344 {
1345         struct virtnet_info *vi = netdev_priv(dev);
1346         u16 queue_pairs = channels->combined_count;
1347         int err;
1348
1349         /* We don't support separate rx/tx channels.
1350          * We don't allow setting 'other' channels.
1351          */
1352         if (channels->rx_count || channels->tx_count || channels->other_count)
1353                 return -EINVAL;
1354
1355         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1356                 return -EINVAL;
1357
1358         get_online_cpus();
1359         err = virtnet_set_queues(vi, queue_pairs);
1360         if (err) {
1361                 put_online_cpus();
1362                 goto err;
1363         }
1364         virtnet_set_affinity(vi);
1365         put_online_cpus();
1366
1367         netif_set_real_num_tx_queues(dev, queue_pairs);
1368         netif_set_real_num_rx_queues(dev, queue_pairs);
1369 err:
1370         return err;
1371 }
1372
1373 static void virtnet_get_channels(struct net_device *dev,
1374                                  struct ethtool_channels *channels)
1375 {
1376         struct virtnet_info *vi = netdev_priv(dev);
1377
1378         channels->combined_count = vi->curr_queue_pairs;
1379         channels->max_combined = vi->max_queue_pairs;
1380         channels->max_other = 0;
1381         channels->rx_count = 0;
1382         channels->tx_count = 0;
1383         channels->other_count = 0;
1384 }
1385
1386 /* Check if the user is trying to change anything besides speed/duplex */
1387 static bool virtnet_validate_ethtool_cmd(const struct ethtool_cmd *cmd)
1388 {
1389         struct ethtool_cmd diff1 = *cmd;
1390         struct ethtool_cmd diff2 = {};
1391
1392         /* cmd is always set so we need to clear it, validate the port type
1393          * and also without autonegotiation we can ignore advertising
1394          */
1395         ethtool_cmd_speed_set(&diff1, 0);
1396         diff2.port = PORT_OTHER;
1397         diff1.advertising = 0;
1398         diff1.duplex = 0;
1399         diff1.cmd = 0;
1400
1401         return !memcmp(&diff1, &diff2, sizeof(diff1));
1402 }
1403
1404 static int virtnet_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1405 {
1406         struct virtnet_info *vi = netdev_priv(dev);
1407         u32 speed;
1408
1409         speed = ethtool_cmd_speed(cmd);
1410         /* don't allow custom speed and duplex */
1411         if (!ethtool_validate_speed(speed) ||
1412             !ethtool_validate_duplex(cmd->duplex) ||
1413             !virtnet_validate_ethtool_cmd(cmd))
1414                 return -EINVAL;
1415         vi->speed = speed;
1416         vi->duplex = cmd->duplex;
1417
1418         return 0;
1419 }
1420
1421 static int virtnet_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1422 {
1423         struct virtnet_info *vi = netdev_priv(dev);
1424
1425         ethtool_cmd_speed_set(cmd, vi->speed);
1426         cmd->duplex = vi->duplex;
1427         cmd->port = PORT_OTHER;
1428
1429         return 0;
1430 }
1431
1432 static void virtnet_init_settings(struct net_device *dev)
1433 {
1434         struct virtnet_info *vi = netdev_priv(dev);
1435
1436         vi->speed = SPEED_UNKNOWN;
1437         vi->duplex = DUPLEX_UNKNOWN;
1438 }
1439
1440 static const struct ethtool_ops virtnet_ethtool_ops = {
1441         .get_drvinfo = virtnet_get_drvinfo,
1442         .get_link = ethtool_op_get_link,
1443         .get_ringparam = virtnet_get_ringparam,
1444         .set_channels = virtnet_set_channels,
1445         .get_channels = virtnet_get_channels,
1446         .get_ts_info = ethtool_op_get_ts_info,
1447         .get_settings = virtnet_get_settings,
1448         .set_settings = virtnet_set_settings,
1449 };
1450
1451 #define MIN_MTU 68
1452 #define MAX_MTU 65535
1453
1454 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1455 {
1456         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1457                 return -EINVAL;
1458         dev->mtu = new_mtu;
1459         return 0;
1460 }
1461
1462 static const struct net_device_ops virtnet_netdev = {
1463         .ndo_open            = virtnet_open,
1464         .ndo_stop            = virtnet_close,
1465         .ndo_start_xmit      = start_xmit,
1466         .ndo_validate_addr   = eth_validate_addr,
1467         .ndo_set_mac_address = virtnet_set_mac_address,
1468         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1469         .ndo_change_mtu      = virtnet_change_mtu,
1470         .ndo_get_stats64     = virtnet_stats,
1471         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1472         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1473 #ifdef CONFIG_NET_POLL_CONTROLLER
1474         .ndo_poll_controller = virtnet_netpoll,
1475 #endif
1476 #ifdef CONFIG_NET_RX_BUSY_POLL
1477         .ndo_busy_poll          = virtnet_busy_poll,
1478 #endif
1479         .ndo_features_check     = passthru_features_check,
1480 };
1481
1482 static void virtnet_config_changed_work(struct work_struct *work)
1483 {
1484         struct virtnet_info *vi =
1485                 container_of(work, struct virtnet_info, config_work);
1486         u16 v;
1487
1488         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1489                                  struct virtio_net_config, status, &v) < 0)
1490                 return;
1491
1492         if (v & VIRTIO_NET_S_ANNOUNCE) {
1493                 netdev_notify_peers(vi->dev);
1494                 virtnet_ack_link_announce(vi);
1495         }
1496
1497         /* Ignore unknown (future) status bits */
1498         v &= VIRTIO_NET_S_LINK_UP;
1499
1500         if (vi->status == v)
1501                 return;
1502
1503         vi->status = v;
1504
1505         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1506                 netif_carrier_on(vi->dev);
1507                 netif_tx_wake_all_queues(vi->dev);
1508         } else {
1509                 netif_carrier_off(vi->dev);
1510                 netif_tx_stop_all_queues(vi->dev);
1511         }
1512 }
1513
1514 static void virtnet_config_changed(struct virtio_device *vdev)
1515 {
1516         struct virtnet_info *vi = vdev->priv;
1517
1518         schedule_work(&vi->config_work);
1519 }
1520
1521 static void virtnet_free_queues(struct virtnet_info *vi)
1522 {
1523         int i;
1524
1525         for (i = 0; i < vi->max_queue_pairs; i++) {
1526                 napi_hash_del(&vi->rq[i].napi);
1527                 netif_napi_del(&vi->rq[i].napi);
1528         }
1529
1530         /* We called napi_hash_del() before netif_napi_del(),
1531          * we need to respect an RCU grace period before freeing vi->rq
1532          */
1533         synchronize_net();
1534
1535         kfree(vi->rq);
1536         kfree(vi->sq);
1537 }
1538
1539 static void free_receive_bufs(struct virtnet_info *vi)
1540 {
1541         int i;
1542
1543         for (i = 0; i < vi->max_queue_pairs; i++) {
1544                 while (vi->rq[i].pages)
1545                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1546         }
1547 }
1548
1549 static void free_receive_page_frags(struct virtnet_info *vi)
1550 {
1551         int i;
1552         for (i = 0; i < vi->max_queue_pairs; i++)
1553                 if (vi->rq[i].alloc_frag.page)
1554                         put_page(vi->rq[i].alloc_frag.page);
1555 }
1556
1557 static void free_unused_bufs(struct virtnet_info *vi)
1558 {
1559         void *buf;
1560         int i;
1561
1562         for (i = 0; i < vi->max_queue_pairs; i++) {
1563                 struct virtqueue *vq = vi->sq[i].vq;
1564                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1565                         dev_kfree_skb(buf);
1566         }
1567
1568         for (i = 0; i < vi->max_queue_pairs; i++) {
1569                 struct virtqueue *vq = vi->rq[i].vq;
1570
1571                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1572                         if (vi->mergeable_rx_bufs) {
1573                                 unsigned long ctx = (unsigned long)buf;
1574                                 void *base = mergeable_ctx_to_buf_address(ctx);
1575                                 put_page(virt_to_head_page(base));
1576                         } else if (vi->big_packets) {
1577                                 give_pages(&vi->rq[i], buf);
1578                         } else {
1579                                 dev_kfree_skb(buf);
1580                         }
1581                 }
1582         }
1583 }
1584
1585 static void virtnet_del_vqs(struct virtnet_info *vi)
1586 {
1587         struct virtio_device *vdev = vi->vdev;
1588
1589         virtnet_clean_affinity(vi, -1);
1590
1591         vdev->config->del_vqs(vdev);
1592
1593         virtnet_free_queues(vi);
1594 }
1595
1596 static int virtnet_find_vqs(struct virtnet_info *vi)
1597 {
1598         vq_callback_t **callbacks;
1599         struct virtqueue **vqs;
1600         int ret = -ENOMEM;
1601         int i, total_vqs;
1602         const char **names;
1603
1604         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1605          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1606          * possible control vq.
1607          */
1608         total_vqs = vi->max_queue_pairs * 2 +
1609                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1610
1611         /* Allocate space for find_vqs parameters */
1612         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1613         if (!vqs)
1614                 goto err_vq;
1615         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1616         if (!callbacks)
1617                 goto err_callback;
1618         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1619         if (!names)
1620                 goto err_names;
1621
1622         /* Parameters for control virtqueue, if any */
1623         if (vi->has_cvq) {
1624                 callbacks[total_vqs - 1] = NULL;
1625                 names[total_vqs - 1] = "control";
1626         }
1627
1628         /* Allocate/initialize parameters for send/receive virtqueues */
1629         for (i = 0; i < vi->max_queue_pairs; i++) {
1630                 callbacks[rxq2vq(i)] = skb_recv_done;
1631                 callbacks[txq2vq(i)] = skb_xmit_done;
1632                 sprintf(vi->rq[i].name, "input.%d", i);
1633                 sprintf(vi->sq[i].name, "output.%d", i);
1634                 names[rxq2vq(i)] = vi->rq[i].name;
1635                 names[txq2vq(i)] = vi->sq[i].name;
1636         }
1637
1638         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1639                                          names);
1640         if (ret)
1641                 goto err_find;
1642
1643         if (vi->has_cvq) {
1644                 vi->cvq = vqs[total_vqs - 1];
1645                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1646                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1647         }
1648
1649         for (i = 0; i < vi->max_queue_pairs; i++) {
1650                 vi->rq[i].vq = vqs[rxq2vq(i)];
1651                 vi->sq[i].vq = vqs[txq2vq(i)];
1652         }
1653
1654         kfree(names);
1655         kfree(callbacks);
1656         kfree(vqs);
1657
1658         return 0;
1659
1660 err_find:
1661         kfree(names);
1662 err_names:
1663         kfree(callbacks);
1664 err_callback:
1665         kfree(vqs);
1666 err_vq:
1667         return ret;
1668 }
1669
1670 static int virtnet_alloc_queues(struct virtnet_info *vi)
1671 {
1672         int i;
1673
1674         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1675         if (!vi->sq)
1676                 goto err_sq;
1677         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1678         if (!vi->rq)
1679                 goto err_rq;
1680
1681         INIT_DELAYED_WORK(&vi->refill, refill_work);
1682         for (i = 0; i < vi->max_queue_pairs; i++) {
1683                 vi->rq[i].pages = NULL;
1684                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1685                                napi_weight);
1686
1687                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1688                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
1689                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1690         }
1691
1692         return 0;
1693
1694 err_rq:
1695         kfree(vi->sq);
1696 err_sq:
1697         return -ENOMEM;
1698 }
1699
1700 static int init_vqs(struct virtnet_info *vi)
1701 {
1702         int ret;
1703
1704         /* Allocate send & receive queues */
1705         ret = virtnet_alloc_queues(vi);
1706         if (ret)
1707                 goto err;
1708
1709         ret = virtnet_find_vqs(vi);
1710         if (ret)
1711                 goto err_free;
1712
1713         get_online_cpus();
1714         virtnet_set_affinity(vi);
1715         put_online_cpus();
1716
1717         return 0;
1718
1719 err_free:
1720         virtnet_free_queues(vi);
1721 err:
1722         return ret;
1723 }
1724
1725 #ifdef CONFIG_SYSFS
1726 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1727                 struct rx_queue_attribute *attribute, char *buf)
1728 {
1729         struct virtnet_info *vi = netdev_priv(queue->dev);
1730         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1731         struct ewma_pkt_len *avg;
1732
1733         BUG_ON(queue_index >= vi->max_queue_pairs);
1734         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1735         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1736 }
1737
1738 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1739         __ATTR_RO(mergeable_rx_buffer_size);
1740
1741 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1742         &mergeable_rx_buffer_size_attribute.attr,
1743         NULL
1744 };
1745
1746 static const struct attribute_group virtio_net_mrg_rx_group = {
1747         .name = "virtio_net",
1748         .attrs = virtio_net_mrg_rx_attrs
1749 };
1750 #endif
1751
1752 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
1753                                     unsigned int fbit,
1754                                     const char *fname, const char *dname)
1755 {
1756         if (!virtio_has_feature(vdev, fbit))
1757                 return false;
1758
1759         dev_err(&vdev->dev, "device advertises feature %s but not %s",
1760                 fname, dname);
1761
1762         return true;
1763 }
1764
1765 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
1766         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
1767
1768 static bool virtnet_validate_features(struct virtio_device *vdev)
1769 {
1770         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
1771             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
1772                              "VIRTIO_NET_F_CTRL_VQ") ||
1773              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
1774                              "VIRTIO_NET_F_CTRL_VQ") ||
1775              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
1776                              "VIRTIO_NET_F_CTRL_VQ") ||
1777              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
1778              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
1779                              "VIRTIO_NET_F_CTRL_VQ"))) {
1780                 return false;
1781         }
1782
1783         return true;
1784 }
1785
1786 static int virtnet_probe(struct virtio_device *vdev)
1787 {
1788         int i, err;
1789         struct net_device *dev;
1790         struct virtnet_info *vi;
1791         u16 max_queue_pairs;
1792         int mtu;
1793
1794         if (!vdev->config->get) {
1795                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
1796                         __func__);
1797                 return -EINVAL;
1798         }
1799
1800         if (!virtnet_validate_features(vdev))
1801                 return -EINVAL;
1802
1803         /* Find if host supports multiqueue virtio_net device */
1804         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1805                                    struct virtio_net_config,
1806                                    max_virtqueue_pairs, &max_queue_pairs);
1807
1808         /* We need at least 2 queue's */
1809         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1810             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1811             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1812                 max_queue_pairs = 1;
1813
1814         /* Allocate ourselves a network device with room for our info */
1815         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1816         if (!dev)
1817                 return -ENOMEM;
1818
1819         /* Set up network device as normal. */
1820         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1821         dev->netdev_ops = &virtnet_netdev;
1822         dev->features = NETIF_F_HIGHDMA;
1823
1824         dev->ethtool_ops = &virtnet_ethtool_ops;
1825         SET_NETDEV_DEV(dev, &vdev->dev);
1826
1827         /* Do we support "hardware" checksums? */
1828         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1829                 /* This opens up the world of extra features. */
1830                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1831                 if (csum)
1832                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1833
1834                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1835                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1836                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1837                 }
1838                 /* Individual feature bits: what can host handle? */
1839                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1840                         dev->hw_features |= NETIF_F_TSO;
1841                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1842                         dev->hw_features |= NETIF_F_TSO6;
1843                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1844                         dev->hw_features |= NETIF_F_TSO_ECN;
1845                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1846                         dev->hw_features |= NETIF_F_UFO;
1847
1848                 dev->features |= NETIF_F_GSO_ROBUST;
1849
1850                 if (gso)
1851                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1852                 /* (!csum && gso) case will be fixed by register_netdev() */
1853         }
1854         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1855                 dev->features |= NETIF_F_RXCSUM;
1856
1857         dev->vlan_features = dev->features;
1858
1859         /* Configuration may specify what MAC to use.  Otherwise random. */
1860         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1861                 virtio_cread_bytes(vdev,
1862                                    offsetof(struct virtio_net_config, mac),
1863                                    dev->dev_addr, dev->addr_len);
1864         else
1865                 eth_hw_addr_random(dev);
1866
1867         /* Set up our device-specific information */
1868         vi = netdev_priv(dev);
1869         vi->dev = dev;
1870         vi->vdev = vdev;
1871         vdev->priv = vi;
1872         vi->stats = alloc_percpu(struct virtnet_stats);
1873         err = -ENOMEM;
1874         if (vi->stats == NULL)
1875                 goto free;
1876
1877         for_each_possible_cpu(i) {
1878                 struct virtnet_stats *virtnet_stats;
1879                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1880                 u64_stats_init(&virtnet_stats->tx_syncp);
1881                 u64_stats_init(&virtnet_stats->rx_syncp);
1882         }
1883
1884         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1885
1886         /* If we can receive ANY GSO packets, we must allocate large ones. */
1887         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1888             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1889             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1890             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1891                 vi->big_packets = true;
1892
1893         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1894                 vi->mergeable_rx_bufs = true;
1895
1896         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
1897             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1898                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1899         else
1900                 vi->hdr_len = sizeof(struct virtio_net_hdr);
1901
1902         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
1903             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1904                 vi->any_header_sg = true;
1905
1906         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1907                 vi->has_cvq = true;
1908
1909         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
1910                 mtu = virtio_cread16(vdev,
1911                                      offsetof(struct virtio_net_config,
1912                                               mtu));
1913                 if (virtnet_change_mtu(dev, mtu))
1914                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
1915         }
1916
1917         if (vi->any_header_sg)
1918                 dev->needed_headroom = vi->hdr_len;
1919
1920         /* Use single tx/rx queue pair as default */
1921         vi->curr_queue_pairs = 1;
1922         vi->max_queue_pairs = max_queue_pairs;
1923
1924         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1925         err = init_vqs(vi);
1926         if (err)
1927                 goto free_stats;
1928
1929 #ifdef CONFIG_SYSFS
1930         if (vi->mergeable_rx_bufs)
1931                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1932 #endif
1933         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1934         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1935
1936         virtnet_init_settings(dev);
1937
1938         err = register_netdev(dev);
1939         if (err) {
1940                 pr_debug("virtio_net: registering device failed\n");
1941                 goto free_vqs;
1942         }
1943
1944         virtio_device_ready(vdev);
1945
1946         err = virtnet_cpu_notif_add(vi);
1947         if (err) {
1948                 pr_debug("virtio_net: registering cpu notifier failed\n");
1949                 goto free_unregister_netdev;
1950         }
1951
1952         /* Assume link up if device can't report link status,
1953            otherwise get link status from config. */
1954         netif_carrier_off(dev);
1955         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1956                 schedule_work(&vi->config_work);
1957         } else {
1958                 vi->status = VIRTIO_NET_S_LINK_UP;
1959                 netif_carrier_on(dev);
1960         }
1961
1962         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1963                  dev->name, max_queue_pairs);
1964
1965         return 0;
1966
1967 free_unregister_netdev:
1968         vi->vdev->config->reset(vdev);
1969
1970         unregister_netdev(dev);
1971 free_vqs:
1972         cancel_delayed_work_sync(&vi->refill);
1973         free_receive_page_frags(vi);
1974         virtnet_del_vqs(vi);
1975 free_stats:
1976         free_percpu(vi->stats);
1977 free:
1978         free_netdev(dev);
1979         return err;
1980 }
1981
1982 static void remove_vq_common(struct virtnet_info *vi)
1983 {
1984         vi->vdev->config->reset(vi->vdev);
1985
1986         /* Free unused buffers in both send and recv, if any. */
1987         free_unused_bufs(vi);
1988
1989         free_receive_bufs(vi);
1990
1991         free_receive_page_frags(vi);
1992
1993         virtnet_del_vqs(vi);
1994 }
1995
1996 static void virtnet_remove(struct virtio_device *vdev)
1997 {
1998         struct virtnet_info *vi = vdev->priv;
1999
2000         virtnet_cpu_notif_remove(vi);
2001
2002         /* Make sure no work handler is accessing the device. */
2003         flush_work(&vi->config_work);
2004
2005         unregister_netdev(vi->dev);
2006
2007         remove_vq_common(vi);
2008
2009         free_percpu(vi->stats);
2010         free_netdev(vi->dev);
2011 }
2012
2013 #ifdef CONFIG_PM_SLEEP
2014 static int virtnet_freeze(struct virtio_device *vdev)
2015 {
2016         struct virtnet_info *vi = vdev->priv;
2017         int i;
2018
2019         virtnet_cpu_notif_remove(vi);
2020
2021         /* Make sure no work handler is accessing the device */
2022         flush_work(&vi->config_work);
2023
2024         netif_device_detach(vi->dev);
2025         cancel_delayed_work_sync(&vi->refill);
2026
2027         if (netif_running(vi->dev)) {
2028                 for (i = 0; i < vi->max_queue_pairs; i++)
2029                         napi_disable(&vi->rq[i].napi);
2030         }
2031
2032         remove_vq_common(vi);
2033
2034         return 0;
2035 }
2036
2037 static int virtnet_restore(struct virtio_device *vdev)
2038 {
2039         struct virtnet_info *vi = vdev->priv;
2040         int err, i;
2041
2042         err = init_vqs(vi);
2043         if (err)
2044                 return err;
2045
2046         virtio_device_ready(vdev);
2047
2048         if (netif_running(vi->dev)) {
2049                 for (i = 0; i < vi->curr_queue_pairs; i++)
2050                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
2051                                 schedule_delayed_work(&vi->refill, 0);
2052
2053                 for (i = 0; i < vi->max_queue_pairs; i++)
2054                         virtnet_napi_enable(&vi->rq[i]);
2055         }
2056
2057         netif_device_attach(vi->dev);
2058
2059         rtnl_lock();
2060         virtnet_set_queues(vi, vi->curr_queue_pairs);
2061         rtnl_unlock();
2062
2063         err = virtnet_cpu_notif_add(vi);
2064         if (err)
2065                 return err;
2066
2067         return 0;
2068 }
2069 #endif
2070
2071 static struct virtio_device_id id_table[] = {
2072         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2073         { 0 },
2074 };
2075
2076 #define VIRTNET_FEATURES \
2077         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
2078         VIRTIO_NET_F_MAC, \
2079         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
2080         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
2081         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
2082         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
2083         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
2084         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
2085         VIRTIO_NET_F_CTRL_MAC_ADDR, \
2086         VIRTIO_NET_F_MTU
2087
2088 static unsigned int features[] = {
2089         VIRTNET_FEATURES,
2090 };
2091
2092 static unsigned int features_legacy[] = {
2093         VIRTNET_FEATURES,
2094         VIRTIO_NET_F_GSO,
2095         VIRTIO_F_ANY_LAYOUT,
2096 };
2097
2098 static struct virtio_driver virtio_net_driver = {
2099         .feature_table = features,
2100         .feature_table_size = ARRAY_SIZE(features),
2101         .feature_table_legacy = features_legacy,
2102         .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
2103         .driver.name =  KBUILD_MODNAME,
2104         .driver.owner = THIS_MODULE,
2105         .id_table =     id_table,
2106         .probe =        virtnet_probe,
2107         .remove =       virtnet_remove,
2108         .config_changed = virtnet_config_changed,
2109 #ifdef CONFIG_PM_SLEEP
2110         .freeze =       virtnet_freeze,
2111         .restore =      virtnet_restore,
2112 #endif
2113 };
2114
2115 static __init int virtio_net_driver_init(void)
2116 {
2117         int ret;
2118
2119         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "AP_VIRT_NET_ONLINE",
2120                                       virtnet_cpu_online,
2121                                       virtnet_cpu_down_prep);
2122         if (ret < 0)
2123                 goto out;
2124         virtionet_online = ret;
2125         ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "VIRT_NET_DEAD",
2126                                       NULL, virtnet_cpu_dead);
2127         if (ret)
2128                 goto err_dead;
2129
2130         ret = register_virtio_driver(&virtio_net_driver);
2131         if (ret)
2132                 goto err_virtio;
2133         return 0;
2134 err_virtio:
2135         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2136 err_dead:
2137         cpuhp_remove_multi_state(virtionet_online);
2138 out:
2139         return ret;
2140 }
2141 module_init(virtio_net_driver_init);
2142
2143 static __exit void virtio_net_driver_exit(void)
2144 {
2145         cpuhp_remove_multi_state(CPUHP_VIRT_NET_DEAD);
2146         cpuhp_remove_multi_state(virtionet_online);
2147         unregister_virtio_driver(&virtio_net_driver);
2148 }
2149 module_exit(virtio_net_driver_exit);
2150
2151 MODULE_DEVICE_TABLE(virtio, id_table);
2152 MODULE_DESCRIPTION("Virtio network driver");
2153 MODULE_LICENSE("GPL");