drivers/net/hyperv/netvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, see <http://www.gnu.org/licenses/>.
  15  *
  16  * Authors:
  17  *   Haiyang Zhang <haiyangz@microsoft.com>
  18  *   Hank Janssen  <hjanssen@microsoft.com>
  19  */
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/init.h>
  23 #include <linux/atomic.h>
  24 #include <linux/module.h>
  25 #include <linux/highmem.h>
  26 #include <linux/device.h>
  27 #include <linux/io.h>
  28 #include <linux/delay.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/etherdevice.h>
  32 #include <linux/skbuff.h>
  33 #include <linux/if_vlan.h>
  34 #include <linux/in.h>
  35 #include <linux/slab.h>
  36 #include <net/arp.h>
  37 #include <net/route.h>
  38 #include <net/sock.h>
  39 #include <net/pkt_sched.h>
  40
  41 #include "hyperv_net.h"
  42
  43
  44 #define RING_SIZE_MIN 64
  45 #define LINKCHANGE_INT (2 * HZ)
  46 #define NETVSC_HW_FEATURES      (NETIF_F_RXCSUM | \
  47                                  NETIF_F_SG | \
  48                                  NETIF_F_TSO | \
  49                                  NETIF_F_TSO6 | \
  50                                  NETIF_F_HW_CSUM)
  51 static int ring_size = 128;
  52 module_param(ring_size, int, S_IRUGO);
  53 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
  54
  55 static int max_num_vrss_chns = 8;
  56
  57 static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
  58                                 NETIF_MSG_LINK | NETIF_MSG_IFUP |
  59                                 NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
  60                                 NETIF_MSG_TX_ERR;
  61
  62 static int debug = -1;
  63 module_param(debug, int, S_IRUGO);
  64 MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
  65
  66 static void do_set_multicast(struct work_struct *w)
  67 {
  68         struct net_device_context *ndevctx =
  69                 container_of(w, struct net_device_context, work);
  70         struct netvsc_device *nvdev;
  71         struct rndis_device *rdev;
  72
  73         nvdev = hv_get_drvdata(ndevctx->device_ctx);
  74         if (nvdev == NULL || nvdev->ndev == NULL)
  75                 return;
  76
  77         rdev = nvdev->extension;
  78         if (rdev == NULL)
  79                 return;
  80
  81         if (nvdev->ndev->flags & IFF_PROMISC)
  82                 rndis_filter_set_packet_filter(rdev,
  83                         NDIS_PACKET_TYPE_PROMISCUOUS);
  84         else
  85                 rndis_filter_set_packet_filter(rdev,
  86                         NDIS_PACKET_TYPE_BROADCAST |
  87                         NDIS_PACKET_TYPE_ALL_MULTICAST |
  88                         NDIS_PACKET_TYPE_DIRECTED);
  89 }
  90
  91 static void netvsc_set_multicast_list(struct net_device *net)
  92 {
  93         struct net_device_context *net_device_ctx = netdev_priv(net);
  94
  95         schedule_work(&net_device_ctx->work);
  96 }
  97
  98 static int netvsc_open(struct net_device *net)
  99 {
 100         struct net_device_context *net_device_ctx = netdev_priv(net);
 101         struct hv_device *device_obj = net_device_ctx->device_ctx;
 102         struct netvsc_device *nvdev;
 103         struct rndis_device *rdev;
 104         int ret = 0;
 105
 106         netif_carrier_off(net);
 107
 108         /* Open up the device */
 109         ret = rndis_filter_open(device_obj);
 110         if (ret != 0) {
 111                 netdev_err(net, "unable to open device (ret %d).\n", ret);
 112                 return ret;
 113         }
 114
 115         netif_tx_wake_all_queues(net);
 116
 117         nvdev = hv_get_drvdata(device_obj);
 118         rdev = nvdev->extension;
 119         if (!rdev->link_state)
 120                 netif_carrier_on(net);
 121
 122         return ret;
 123 }
 124
 125 static int netvsc_close(struct net_device *net)
 126 {
 127         struct net_device_context *net_device_ctx = netdev_priv(net);
 128         struct hv_device *device_obj = net_device_ctx->device_ctx;
 129         struct netvsc_device *nvdev = hv_get_drvdata(device_obj);
 130         int ret;
 131         u32 aread, awrite, i, msec = 10, retry = 0, retry_max = 20;
 132         struct vmbus_channel *chn;
 133
 134         netif_tx_disable(net);
 135
 136         /* Make sure netvsc_set_multicast_list doesn't re-enable filter! */
 137         cancel_work_sync(&net_device_ctx->work);
 138         ret = rndis_filter_close(device_obj);
 139         if (ret != 0) {
 140                 netdev_err(net, "unable to close device (ret %d).\n", ret);
 141                 return ret;
 142         }
 143
 144         /* Ensure pending bytes in ring are read */
 145         while (true) {
 146                 aread = 0;
 147                 for (i = 0; i < nvdev->num_chn; i++) {
 148                         chn = nvdev->chn_table[i];
 149                         if (!chn)
 150                                 continue;
 151
 152                         hv_get_ringbuffer_availbytes(&chn->inbound, &aread,
 153                                                      &awrite);
 154
 155                         if (aread)
 156                                 break;
 157
 158                         hv_get_ringbuffer_availbytes(&chn->outbound, &aread,
 159                                                      &awrite);
 160
 161                         if (aread)
 162                                 break;
 163                 }
 164
 165                 retry++;
 166                 if (retry > retry_max || aread == 0)
 167                         break;
 168
 169                 msleep(msec);
 170
 171                 if (msec < 1000)
 172                         msec *= 2;
 173         }
 174
 175         if (aread) {
 176                 netdev_err(net, "Ring buffer not empty after closing rndis\n");
 177                 ret = -ETIMEDOUT;
 178         }
 179
 180         return ret;
 181 }
 182
 183 static void *init_ppi_data(struct rndis_message *msg, u32 ppi_size,
 184                                 int pkt_type)
 185 {
 186         struct rndis_packet *rndis_pkt;
 187         struct rndis_per_packet_info *ppi;
 188
 189         rndis_pkt = &msg->msg.pkt;
 190         rndis_pkt->data_offset += ppi_size;
 191
 192         ppi = (struct rndis_per_packet_info *)((void *)rndis_pkt +
 193                 rndis_pkt->per_pkt_info_offset + rndis_pkt->per_pkt_info_len);
 194
 195         ppi->size = ppi_size;
 196         ppi->type = pkt_type;
 197         ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
 198
 199         rndis_pkt->per_pkt_info_len += ppi_size;
 200
 201         return ppi;
 202 }
 203
 204 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
 205                         void *accel_priv, select_queue_fallback_t fallback)
 206 {
 207         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 208         struct hv_device *hdev =  net_device_ctx->device_ctx;
 209         struct netvsc_device *nvsc_dev = hv_get_drvdata(hdev);
 210         u32 hash;
 211         u16 q_idx = 0;
 212
 213         if (nvsc_dev == NULL || ndev->real_num_tx_queues <= 1)
 214                 return 0;
 215
 216         hash = skb_get_hash(skb);
 217         q_idx = nvsc_dev->send_table[hash % VRSS_SEND_TAB_SIZE] %
 218                 ndev->real_num_tx_queues;
 219
 220         if (!nvsc_dev->chn_table[q_idx])
 221                 q_idx = 0;
 222
 223         return q_idx;
 224 }
 225
 226 static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
 227                         struct hv_page_buffer *pb)
 228 {
 229         int j = 0;
 230
 231         /* Deal with compund pages by ignoring unused part
 232          * of the page.
 233          */
 234         page += (offset >> PAGE_SHIFT);
 235         offset &= ~PAGE_MASK;
 236
 237         while (len > 0) {
 238                 unsigned long bytes;
 239
 240                 bytes = PAGE_SIZE - offset;
 241                 if (bytes > len)
 242                         bytes = len;
 243                 pb[j].pfn = page_to_pfn(page);
 244                 pb[j].offset = offset;
 245                 pb[j].len = bytes;
 246
 247                 offset += bytes;
 248                 len -= bytes;
 249
 250                 if (offset == PAGE_SIZE && len) {
 251                         page++;
 252                         offset = 0;
 253                         j++;
 254                 }
 255         }
 256
 257         return j + 1;
 258 }
 259
 260 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
 261                            struct hv_netvsc_packet *packet,
 262                            struct hv_page_buffer **page_buf)
 263 {
 264         struct hv_page_buffer *pb = *page_buf;
 265         u32 slots_used = 0;
 266         char *data = skb->data;
 267         int frags = skb_shinfo(skb)->nr_frags;
 268         int i;
 269
 270         /* The packet is laid out thus:
 271          * 1. hdr: RNDIS header and PPI
 272          * 2. skb linear data
 273          * 3. skb fragment data
 274          */
 275         if (hdr != NULL)
 276                 slots_used += fill_pg_buf(virt_to_page(hdr),
 277                                         offset_in_page(hdr),
 278                                         len, &pb[slots_used]);
 279
 280         packet->rmsg_size = len;
 281         packet->rmsg_pgcnt = slots_used;
 282
 283         slots_used += fill_pg_buf(virt_to_page(data),
 284                                 offset_in_page(data),
 285                                 skb_headlen(skb), &pb[slots_used]);
 286
 287         for (i = 0; i < frags; i++) {
 288                 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
 289
 290                 slots_used += fill_pg_buf(skb_frag_page(frag),
 291                                         frag->page_offset,
 292                                         skb_frag_size(frag), &pb[slots_used]);
 293         }
 294         return slots_used;
 295 }
 296
 297 static int count_skb_frag_slots(struct sk_buff *skb)
 298 {
 299         int i, frags = skb_shinfo(skb)->nr_frags;
 300         int pages = 0;
 301
 302         for (i = 0; i < frags; i++) {
 303                 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
 304                 unsigned long size = skb_frag_size(frag);
 305                 unsigned long offset = frag->page_offset;
 306
 307                 /* Skip unused frames from start of page */
 308                 offset &= ~PAGE_MASK;
 309                 pages += PFN_UP(offset + size);
 310         }
 311         return pages;
 312 }
 313
 314 static int netvsc_get_slots(struct sk_buff *skb)
 315 {
 316         char *data = skb->data;
 317         unsigned int offset = offset_in_page(data);
 318         unsigned int len = skb_headlen(skb);
 319         int slots;
 320         int frag_slots;
 321
 322         slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
 323         frag_slots = count_skb_frag_slots(skb);
 324         return slots + frag_slots;
 325 }
 326
 327 static u32 get_net_transport_info(struct sk_buff *skb, u32 *trans_off)
 328 {
 329         u32 ret_val = TRANSPORT_INFO_NOT_IP;
 330
 331         if ((eth_hdr(skb)->h_proto != htons(ETH_P_IP)) &&
 332                 (eth_hdr(skb)->h_proto != htons(ETH_P_IPV6))) {
 333                 goto not_ip;
 334         }
 335
 336         *trans_off = skb_transport_offset(skb);
 337
 338         if ((eth_hdr(skb)->h_proto == htons(ETH_P_IP))) {
 339                 struct iphdr *iphdr = ip_hdr(skb);
 340
 341                 if (iphdr->protocol == IPPROTO_TCP)
 342                         ret_val = TRANSPORT_INFO_IPV4_TCP;
 343                 else if (iphdr->protocol == IPPROTO_UDP)
 344                         ret_val = TRANSPORT_INFO_IPV4_UDP;
 345         } else {
 346                 if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
 347                         ret_val = TRANSPORT_INFO_IPV6_TCP;
 348                 else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
 349                         ret_val = TRANSPORT_INFO_IPV6_UDP;
 350         }
 351
 352 not_ip:
 353         return ret_val;
 354 }
 355
 356 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 357 {
 358         struct net_device_context *net_device_ctx = netdev_priv(net);
 359         struct hv_netvsc_packet *packet = NULL;
 360         int ret;
 361         unsigned int num_data_pgs;
 362         struct rndis_message *rndis_msg;
 363         struct rndis_packet *rndis_pkt;
 364         u32 rndis_msg_size;
 365         bool isvlan;
 366         bool linear = false;
 367         struct rndis_per_packet_info *ppi;
 368         struct ndis_tcp_ip_checksum_info *csum_info;
 369         struct ndis_tcp_lso_info *lso_info;
 370         int  hdr_offset;
 371         u32 net_trans_info;
 372         u32 hash;
 373         u32 skb_length;
 374         struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT];
 375         struct hv_page_buffer *pb = page_buf;
 376         struct netvsc_stats *tx_stats = this_cpu_ptr(net_device_ctx->tx_stats);
 377
 378         /* We will atmost need two pages to describe the rndis
 379          * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
 380          * of pages in a single packet. If skb is scattered around
 381          * more pages we try linearizing it.
 382          */
 383
 384 check_size:
 385         skb_length = skb->len;
 386         num_data_pgs = netvsc_get_slots(skb) + 2;
 387         if (num_data_pgs > MAX_PAGE_BUFFER_COUNT && linear) {
 388                 net_alert_ratelimited("packet too big: %u pages (%u bytes)\n",
 389                                       num_data_pgs, skb->len);
 390                 ret = -EFAULT;
 391                 goto drop;
 392         } else if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
 393                 if (skb_linearize(skb)) {
 394                         net_alert_ratelimited("failed to linearize skb\n");
 395                         ret = -ENOMEM;
 396                         goto drop;
 397                 }
 398                 linear = true;
 399                 goto check_size;
 400         }
 401
 402         /*
 403          * Place the rndis header in the skb head room and
 404          * the skb->cb will be used for hv_netvsc_packet
 405          * structure.
 406          */
 407         ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
 408         if (ret) {
 409                 netdev_err(net, "unable to alloc hv_netvsc_packet\n");
 410                 ret = -ENOMEM;
 411                 goto drop;
 412         }
 413         /* Use the skb control buffer for building up the packet */
 414         BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
 415                         FIELD_SIZEOF(struct sk_buff, cb));
 416         packet = (struct hv_netvsc_packet *)skb->cb;
 417
 418
 419         packet->q_idx = skb_get_queue_mapping(skb);
 420
 421         packet->total_data_buflen = skb->len;
 422
 423         rndis_msg = (struct rndis_message *)skb->head;
 424
 425         memset(rndis_msg, 0, RNDIS_AND_PPI_SIZE);
 426
 427         isvlan = skb->vlan_tci & VLAN_TAG_PRESENT;
 428
 429         /* Add the rndis header */
 430         rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
 431         rndis_msg->msg_len = packet->total_data_buflen;
 432         rndis_pkt = &rndis_msg->msg.pkt;
 433         rndis_pkt->data_offset = sizeof(struct rndis_packet);
 434         rndis_pkt->data_len = packet->total_data_buflen;
 435         rndis_pkt->per_pkt_info_offset = sizeof(struct rndis_packet);
 436
 437         rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
 438
 439         hash = skb_get_hash_raw(skb);
 440         if (hash != 0 && net->real_num_tx_queues > 1) {
 441                 rndis_msg_size += NDIS_HASH_PPI_SIZE;
 442                 ppi = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
 443                                     NBL_HASH_VALUE);
 444                 *(u32 *)((void *)ppi + ppi->ppi_offset) = hash;
 445         }
 446
 447         if (isvlan) {
 448                 struct ndis_pkt_8021q_info *vlan;
 449
 450                 rndis_msg_size += NDIS_VLAN_PPI_SIZE;
 451                 ppi = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
 452                                         IEEE_8021Q_INFO);
 453                 vlan = (struct ndis_pkt_8021q_info *)((void *)ppi +
 454                                                 ppi->ppi_offset);
 455                 vlan->vlanid = skb->vlan_tci & VLAN_VID_MASK;
 456                 vlan->pri = (skb->vlan_tci & VLAN_PRIO_MASK) >>
 457                                 VLAN_PRIO_SHIFT;
 458         }
 459
 460         net_trans_info = get_net_transport_info(skb, &hdr_offset);
 461         if (net_trans_info == TRANSPORT_INFO_NOT_IP)
 462                 goto do_send;
 463
 464         /*
 465          * Setup the sendside checksum offload only if this is not a
 466          * GSO packet.
 467          */
 468         if (skb_is_gso(skb))
 469                 goto do_lso;
 470
 471         if ((skb->ip_summed == CHECKSUM_NONE) ||
 472             (skb->ip_summed == CHECKSUM_UNNECESSARY))
 473                 goto do_send;
 474
 475         rndis_msg_size += NDIS_CSUM_PPI_SIZE;
 476         ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
 477                             TCPIP_CHKSUM_PKTINFO);
 478
 479         csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
 480                         ppi->ppi_offset);
 481
 482         if (net_trans_info & (INFO_IPV4 << 16))
 483                 csum_info->transmit.is_ipv4 = 1;
 484         else
 485                 csum_info->transmit.is_ipv6 = 1;
 486
 487         if (net_trans_info & INFO_TCP) {
 488                 csum_info->transmit.tcp_checksum = 1;
 489                 csum_info->transmit.tcp_header_offset = hdr_offset;
 490         } else if (net_trans_info & INFO_UDP) {
 491                 /* UDP checksum offload is not supported on ws2008r2.
 492                  * Furthermore, on ws2012 and ws2012r2, there are some
 493                  * issues with udp checksum offload from Linux guests.
 494                  * (these are host issues).
 495                  * For now compute the checksum here.
 496                  */
 497                 struct udphdr *uh;
 498                 u16 udp_len;
 499
 500                 ret = skb_cow_head(skb, 0);
 501                 if (ret)
 502                         goto drop;
 503
 504                 uh = udp_hdr(skb);
 505                 udp_len = ntohs(uh->len);
 506                 uh->check = 0;
 507                 uh->check = csum_tcpudp_magic(ip_hdr(skb)->saddr,
 508                                               ip_hdr(skb)->daddr,
 509                                               udp_len, IPPROTO_UDP,
 510                                               csum_partial(uh, udp_len, 0));
 511                 if (uh->check == 0)
 512                         uh->check = CSUM_MANGLED_0;
 513
 514                 csum_info->transmit.udp_checksum = 0;
 515         }
 516         goto do_send;
 517
 518 do_lso:
 519         rndis_msg_size += NDIS_LSO_PPI_SIZE;
 520         ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
 521                             TCP_LARGESEND_PKTINFO);
 522
 523         lso_info = (struct ndis_tcp_lso_info *)((void *)ppi +
 524                         ppi->ppi_offset);
 525
 526         lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
 527         if (net_trans_info & (INFO_IPV4 << 16)) {
 528                 lso_info->lso_v2_transmit.ip_version =
 529                         NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
 530                 ip_hdr(skb)->tot_len = 0;
 531                 ip_hdr(skb)->check = 0;
 532                 tcp_hdr(skb)->check =
 533                 ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
 534                                    ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
 535         } else {
 536                 lso_info->lso_v2_transmit.ip_version =
 537                         NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
 538                 ipv6_hdr(skb)->payload_len = 0;
 539                 tcp_hdr(skb)->check =
 540                 ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
 541                                 &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
 542         }
 543         lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
 544         lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
 545
 546 do_send:
 547         /* Start filling in the page buffers with the rndis hdr */
 548         rndis_msg->msg_len += rndis_msg_size;
 549         packet->total_data_buflen = rndis_msg->msg_len;
 550         packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
 551                                                skb, packet, &pb);
 552
 553         /* timestamp packet in software */
 554         skb_tx_timestamp(skb);
 555         ret = netvsc_send(net_device_ctx->device_ctx, packet,
 556                           rndis_msg, &pb, skb);
 557
 558 drop:
 559         if (ret == 0) {
 560                 u64_stats_update_begin(&tx_stats->syncp);
 561                 tx_stats->packets++;
 562                 tx_stats->bytes += skb_length;
 563                 u64_stats_update_end(&tx_stats->syncp);
 564         } else {
 565                 if (ret != -EAGAIN) {
 566                         dev_kfree_skb_any(skb);
 567                         net->stats.tx_dropped++;
 568                 }
 569         }
 570
 571         return (ret == -EAGAIN) ? NETDEV_TX_BUSY : NETDEV_TX_OK;
 572 }
 573
 574 /*
 575  * netvsc_linkstatus_callback - Link up/down notification
 576  */
 577 void netvsc_linkstatus_callback(struct hv_device *device_obj,
 578                                 struct rndis_message *resp)
 579 {
 580         struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
 581         struct net_device *net;
 582         struct net_device_context *ndev_ctx;
 583         struct netvsc_device *net_device;
 584         struct netvsc_reconfig *event;
 585         unsigned long flags;
 586
 587         /* Handle link change statuses only */
 588         if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
 589             indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
 590             indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
 591                 return;
 592
 593         net_device = hv_get_drvdata(device_obj);
 594         net = net_device->ndev;
 595
 596         if (!net || net->reg_state != NETREG_REGISTERED)
 597                 return;
 598
 599         ndev_ctx = netdev_priv(net);
 600
 601         event = kzalloc(sizeof(*event), GFP_ATOMIC);
 602         if (!event)
 603                 return;
 604         event->event = indicate->status;
 605
 606         spin_lock_irqsave(&ndev_ctx->lock, flags);
 607         list_add_tail(&event->list, &ndev_ctx->reconfig_events);
 608         spin_unlock_irqrestore(&ndev_ctx->lock, flags);
 609
 610         schedule_delayed_work(&ndev_ctx->dwork, 0);
 611 }
 612
 613 /*
 614  * netvsc_recv_callback -  Callback when we receive a packet from the
 615  * "wire" on the specified device.
 616  */
 617 int netvsc_recv_callback(struct hv_device *device_obj,
 618                                 struct hv_netvsc_packet *packet,
 619                                 void **data,
 620                                 struct ndis_tcp_ip_checksum_info *csum_info,
 621                                 struct vmbus_channel *channel,
 622                                 u16 vlan_tci)
 623 {
 624         struct net_device *net;
 625         struct net_device_context *net_device_ctx;
 626         struct sk_buff *skb;
 627         struct netvsc_stats *rx_stats;
 628
 629         net = ((struct netvsc_device *)hv_get_drvdata(device_obj))->ndev;
 630         if (!net || net->reg_state != NETREG_REGISTERED) {
 631                 return NVSP_STAT_FAIL;
 632         }
 633         net_device_ctx = netdev_priv(net);
 634         rx_stats = this_cpu_ptr(net_device_ctx->rx_stats);
 635
 636         /* Allocate a skb - TODO direct I/O to pages? */
 637         skb = netdev_alloc_skb_ip_align(net, packet->total_data_buflen);
 638         if (unlikely(!skb)) {
 639                 ++net->stats.rx_dropped;
 640                 return NVSP_STAT_FAIL;
 641         }
 642
 643         /*
 644          * Copy to skb. This copy is needed here since the memory pointed by
 645          * hv_netvsc_packet cannot be deallocated
 646          */
 647         memcpy(skb_put(skb, packet->total_data_buflen), *data,
 648                 packet->total_data_buflen);
 649
 650         skb->protocol = eth_type_trans(skb, net);
 651         if (csum_info) {
 652                 /* We only look at the IP checksum here.
 653                  * Should we be dropping the packet if checksum
 654                  * failed? How do we deal with other checksums - TCP/UDP?
 655                  */
 656                 if (csum_info->receive.ip_checksum_succeeded)
 657                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 658                 else
 659                         skb->ip_summed = CHECKSUM_NONE;
 660         }
 661
 662         if (vlan_tci & VLAN_TAG_PRESENT)
 663                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
 664                                        vlan_tci);
 665
 666         skb_record_rx_queue(skb, channel->
 667                             offermsg.offer.sub_channel_index);
 668
 669         u64_stats_update_begin(&rx_stats->syncp);
 670         rx_stats->packets++;
 671         rx_stats->bytes += packet->total_data_buflen;
 672         u64_stats_update_end(&rx_stats->syncp);
 673
 674         /*
 675          * Pass the skb back up. Network stack will deallocate the skb when it
 676          * is done.
 677          * TODO - use NAPI?
 678          */
 679         netif_rx(skb);
 680
 681         return 0;
 682 }
 683
 684 static void netvsc_get_drvinfo(struct net_device *net,
 685                                struct ethtool_drvinfo *info)
 686 {
 687         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
 688         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 689 }
 690
 691 static void netvsc_get_channels(struct net_device *net,
 692                                 struct ethtool_channels *channel)
 693 {
 694         struct net_device_context *net_device_ctx = netdev_priv(net);
 695         struct hv_device *dev = net_device_ctx->device_ctx;
 696         struct netvsc_device *nvdev = hv_get_drvdata(dev);
 697
 698         if (nvdev) {
 699                 channel->max_combined   = nvdev->max_chn;
 700                 channel->combined_count = nvdev->num_chn;
 701         }
 702 }
 703
 704 static int netvsc_set_channels(struct net_device *net,
 705                                struct ethtool_channels *channels)
 706 {
 707         struct net_device_context *net_device_ctx = netdev_priv(net);
 708         struct hv_device *dev = net_device_ctx->device_ctx;
 709         struct netvsc_device *nvdev = hv_get_drvdata(dev);
 710         struct netvsc_device_info device_info;
 711         u32 num_chn;
 712         u32 max_chn;
 713         int ret = 0;
 714         bool recovering = false;
 715
 716         if (!nvdev || nvdev->destroy)
 717                 return -ENODEV;
 718
 719         num_chn = nvdev->num_chn;
 720         max_chn = min_t(u32, nvdev->max_chn, num_online_cpus());
 721
 722         if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5) {
 723                 pr_info("vRSS unsupported before NVSP Version 5\n");
 724                 return -EINVAL;
 725         }
 726
 727         /* We do not support rx, tx, or other */
 728         if (!channels ||
 729             channels->rx_count ||
 730             channels->tx_count ||
 731             channels->other_count ||
 732             (channels->combined_count < 1))
 733                 return -EINVAL;
 734
 735         if (channels->combined_count > max_chn) {
 736                 pr_info("combined channels too high, using %d\n", max_chn);
 737                 channels->combined_count = max_chn;
 738         }
 739
 740         ret = netvsc_close(net);
 741         if (ret)
 742                 goto out;
 743
 744  do_set:
 745         nvdev->start_remove = true;
 746         rndis_filter_device_remove(dev);
 747
 748         nvdev->num_chn = channels->combined_count;
 749
 750         net_device_ctx->device_ctx = dev;
 751         hv_set_drvdata(dev, net);
 752
 753         memset(&device_info, 0, sizeof(device_info));
 754         device_info.num_chn = nvdev->num_chn; /* passed to RNDIS */
 755         device_info.ring_size = ring_size;
 756         device_info.max_num_vrss_chns = max_num_vrss_chns;
 757
 758         ret = rndis_filter_device_add(dev, &device_info);
 759         if (ret) {
 760                 if (recovering) {
 761                         netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
 762                         return ret;
 763                 }
 764                 goto recover;
 765         }
 766
 767         nvdev = hv_get_drvdata(dev);
 768
 769         ret = netif_set_real_num_tx_queues(net, nvdev->num_chn);
 770         if (ret) {
 771                 if (recovering) {
 772                         netdev_err(net, "could not set tx queue count (ret %d)\n", ret);
 773                         return ret;
 774                 }
 775                 goto recover;
 776         }
 777
 778         ret = netif_set_real_num_rx_queues(net, nvdev->num_chn);
 779         if (ret) {
 780                 if (recovering) {
 781                         netdev_err(net, "could not set rx queue count (ret %d)\n", ret);
 782                         return ret;
 783                 }
 784                 goto recover;
 785         }
 786
 787  out:
 788         netvsc_open(net);
 789
 790         return ret;
 791
 792  recover:
 793         /* If the above failed, we attempt to recover through the same
 794          * process but with the original number of channels.
 795          */
 796         netdev_err(net, "could not set channels, recovering\n");
 797         recovering = true;
 798         channels->combined_count = num_chn;
 799         goto do_set;
 800 }
 801
 802 static bool netvsc_validate_ethtool_ss_cmd(const struct ethtool_cmd *cmd)
 803 {
 804         struct ethtool_cmd diff1 = *cmd;
 805         struct ethtool_cmd diff2 = {};
 806
 807         ethtool_cmd_speed_set(&diff1, 0);
 808         diff1.duplex = 0;
 809         /* advertising and cmd are usually set */
 810         diff1.advertising = 0;
 811         diff1.cmd = 0;
 812         /* We set port to PORT_OTHER */
 813         diff2.port = PORT_OTHER;
 814
 815         return !memcmp(&diff1, &diff2, sizeof(diff1));
 816 }
 817
 818 static void netvsc_init_settings(struct net_device *dev)
 819 {
 820         struct net_device_context *ndc = netdev_priv(dev);
 821
 822         ndc->speed = SPEED_UNKNOWN;
 823         ndc->duplex = DUPLEX_UNKNOWN;
 824 }
 825
 826 static int netvsc_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 827 {
 828         struct net_device_context *ndc = netdev_priv(dev);
 829
 830         ethtool_cmd_speed_set(cmd, ndc->speed);
 831         cmd->duplex = ndc->duplex;
 832         cmd->port = PORT_OTHER;
 833
 834         return 0;
 835 }
 836
 837 static int netvsc_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 838 {
 839         struct net_device_context *ndc = netdev_priv(dev);
 840         u32 speed;
 841
 842         speed = ethtool_cmd_speed(cmd);
 843         if (!ethtool_validate_speed(speed) ||
 844             !ethtool_validate_duplex(cmd->duplex) ||
 845             !netvsc_validate_ethtool_ss_cmd(cmd))
 846                 return -EINVAL;
 847
 848         ndc->speed = speed;
 849         ndc->duplex = cmd->duplex;
 850
 851         return 0;
 852 }
 853
 854 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 855 {
 856         struct net_device_context *ndevctx = netdev_priv(ndev);
 857         struct hv_device *hdev =  ndevctx->device_ctx;
 858         struct netvsc_device *nvdev = hv_get_drvdata(hdev);
 859         struct netvsc_device_info device_info;
 860         int limit = ETH_DATA_LEN;
 861         int ret = 0;
 862
 863         if (nvdev == NULL || nvdev->destroy)
 864                 return -ENODEV;
 865
 866         if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
 867                 limit = NETVSC_MTU - ETH_HLEN;
 868
 869         if (mtu < NETVSC_MTU_MIN || mtu > limit)
 870                 return -EINVAL;
 871
 872         ret = netvsc_close(ndev);
 873         if (ret)
 874                 goto out;
 875
 876         nvdev->start_remove = true;
 877         rndis_filter_device_remove(hdev);
 878
 879         ndev->mtu = mtu;
 880
 881         ndevctx->device_ctx = hdev;
 882         hv_set_drvdata(hdev, ndev);
 883
 884         memset(&device_info, 0, sizeof(device_info));
 885         device_info.ring_size = ring_size;
 886         device_info.num_chn = nvdev->num_chn;
 887         device_info.max_num_vrss_chns = max_num_vrss_chns;
 888         rndis_filter_device_add(hdev, &device_info);
 889
 890 out:
 891         netvsc_open(ndev);
 892
 893         return ret;
 894 }
 895
 896 static struct rtnl_link_stats64 *netvsc_get_stats64(struct net_device *net,
 897                                                     struct rtnl_link_stats64 *t)
 898 {
 899         struct net_device_context *ndev_ctx = netdev_priv(net);
 900         int cpu;
 901
 902         for_each_possible_cpu(cpu) {
 903                 struct netvsc_stats *tx_stats = per_cpu_ptr(ndev_ctx->tx_stats,
 904                                                             cpu);
 905                 struct netvsc_stats *rx_stats = per_cpu_ptr(ndev_ctx->rx_stats,
 906                                                             cpu);
 907                 u64 tx_packets, tx_bytes, rx_packets, rx_bytes;
 908                 unsigned int start;
 909
 910                 do {
 911                         start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
 912                         tx_packets = tx_stats->packets;
 913                         tx_bytes = tx_stats->bytes;
 914                 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
 915
 916                 do {
 917                         start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
 918                         rx_packets = rx_stats->packets;
 919                         rx_bytes = rx_stats->bytes;
 920                 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
 921
 922                 t->tx_bytes     += tx_bytes;
 923                 t->tx_packets   += tx_packets;
 924                 t->rx_bytes     += rx_bytes;
 925                 t->rx_packets   += rx_packets;
 926         }
 927
 928         t->tx_dropped   = net->stats.tx_dropped;
 929         t->tx_errors    = net->stats.tx_dropped;
 930
 931         t->rx_dropped   = net->stats.rx_dropped;
 932         t->rx_errors    = net->stats.rx_errors;
 933
 934         return t;
 935 }
 936
 937 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
 938 {
 939         struct net_device_context *ndevctx = netdev_priv(ndev);
 940         struct hv_device *hdev =  ndevctx->device_ctx;
 941         struct sockaddr *addr = p;
 942         char save_adr[ETH_ALEN];
 943         unsigned char save_aatype;
 944         int err;
 945
 946         memcpy(save_adr, ndev->dev_addr, ETH_ALEN);
 947         save_aatype = ndev->addr_assign_type;
 948
 949         err = eth_mac_addr(ndev, p);
 950         if (err != 0)
 951                 return err;
 952
 953         err = rndis_filter_set_device_mac(hdev, addr->sa_data);
 954         if (err != 0) {
 955                 /* roll back to saved MAC */
 956                 memcpy(ndev->dev_addr, save_adr, ETH_ALEN);
 957                 ndev->addr_assign_type = save_aatype;
 958         }
 959
 960         return err;
 961 }
 962
 963 #ifdef CONFIG_NET_POLL_CONTROLLER
 964 static void netvsc_poll_controller(struct net_device *net)
 965 {
 966         /* As netvsc_start_xmit() works synchronous we don't have to
 967          * trigger anything here.
 968          */
 969 }
 970 #endif
 971
 972 static const struct ethtool_ops ethtool_ops = {
 973         .get_drvinfo    = netvsc_get_drvinfo,
 974         .get_link       = ethtool_op_get_link,
 975         .get_channels   = netvsc_get_channels,
 976         .set_channels   = netvsc_set_channels,
 977         .get_ts_info    = ethtool_op_get_ts_info,
 978         .get_settings   = netvsc_get_settings,
 979         .set_settings   = netvsc_set_settings,
 980 };
 981
 982 static const struct net_device_ops device_ops = {
 983         .ndo_open =                     netvsc_open,
 984         .ndo_stop =                     netvsc_close,
 985         .ndo_start_xmit =               netvsc_start_xmit,
 986         .ndo_set_rx_mode =              netvsc_set_multicast_list,
 987         .ndo_change_mtu =               netvsc_change_mtu,
 988         .ndo_validate_addr =            eth_validate_addr,
 989         .ndo_set_mac_address =          netvsc_set_mac_addr,
 990         .ndo_select_queue =             netvsc_select_queue,
 991         .ndo_get_stats64 =              netvsc_get_stats64,
 992 #ifdef CONFIG_NET_POLL_CONTROLLER
 993         .ndo_poll_controller =          netvsc_poll_controller,
 994 #endif
 995 };
 996
 997 /*
 998  * Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
 999  * down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
1000  * present send GARP packet to network peers with netif_notify_peers().
1001  */
1002 static void netvsc_link_change(struct work_struct *w)
1003 {
1004         struct net_device_context *ndev_ctx;
1005         struct net_device *net;
1006         struct netvsc_device *net_device;
1007         struct rndis_device *rdev;
1008         struct netvsc_reconfig *event = NULL;
1009         bool notify = false, reschedule = false;
1010         unsigned long flags, next_reconfig, delay;
1011
1012         ndev_ctx = container_of(w, struct net_device_context, dwork.work);
1013         net_device = hv_get_drvdata(ndev_ctx->device_ctx);
1014         rdev = net_device->extension;
1015         net = net_device->ndev;
1016
1017         next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
1018         if (time_is_after_jiffies(next_reconfig)) {
1019                 /* link_watch only sends one notification with current state
1020                  * per second, avoid doing reconfig more frequently. Handle
1021                  * wrap around.
1022                  */
1023                 delay = next_reconfig - jiffies;
1024                 delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
1025                 schedule_delayed_work(&ndev_ctx->dwork, delay);
1026                 return;
1027         }
1028         ndev_ctx->last_reconfig = jiffies;
1029
1030         spin_lock_irqsave(&ndev_ctx->lock, flags);
1031         if (!list_empty(&ndev_ctx->reconfig_events)) {
1032                 event = list_first_entry(&ndev_ctx->reconfig_events,
1033                                          struct netvsc_reconfig, list);
1034                 list_del(&event->list);
1035                 reschedule = !list_empty(&ndev_ctx->reconfig_events);
1036         }
1037         spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1038
1039         if (!event)
1040                 return;
1041
1042         rtnl_lock();
1043
1044         switch (event->event) {
1045                 /* Only the following events are possible due to the check in
1046                  * netvsc_linkstatus_callback()
1047                  */
1048         case RNDIS_STATUS_MEDIA_CONNECT:
1049                 if (rdev->link_state) {
1050                         rdev->link_state = false;
1051                         netif_carrier_on(net);
1052                         netif_tx_wake_all_queues(net);
1053                 } else {
1054                         notify = true;
1055                 }
1056                 kfree(event);
1057                 break;
1058         case RNDIS_STATUS_MEDIA_DISCONNECT:
1059                 if (!rdev->link_state) {
1060                         rdev->link_state = true;
1061                         netif_carrier_off(net);
1062                         netif_tx_stop_all_queues(net);
1063                 }
1064                 kfree(event);
1065                 break;
1066         case RNDIS_STATUS_NETWORK_CHANGE:
1067                 /* Only makes sense if carrier is present */
1068                 if (!rdev->link_state) {
1069                         rdev->link_state = true;
1070                         netif_carrier_off(net);
1071                         netif_tx_stop_all_queues(net);
1072                         event->event = RNDIS_STATUS_MEDIA_CONNECT;
1073                         spin_lock_irqsave(&ndev_ctx->lock, flags);
1074                         list_add_tail(&event->list, &ndev_ctx->reconfig_events);
1075                         spin_unlock_irqrestore(&ndev_ctx->lock, flags);
1076                         reschedule = true;
1077                 }
1078                 break;
1079         }
1080
1081         rtnl_unlock();
1082
1083         if (notify)
1084                 netdev_notify_peers(net);
1085
1086         /* link_watch only sends one notification with current state per
1087          * second, handle next reconfig event in 2 seconds.
1088          */
1089         if (reschedule)
1090                 schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
1091 }
1092
1093 static void netvsc_free_netdev(struct net_device *netdev)
1094 {
1095         struct net_device_context *net_device_ctx = netdev_priv(netdev);
1096
1097         free_percpu(net_device_ctx->tx_stats);
1098         free_percpu(net_device_ctx->rx_stats);
1099         free_netdev(netdev);
1100 }
1101
1102 static int netvsc_probe(struct hv_device *dev,
1103                         const struct hv_vmbus_device_id *dev_id)
1104 {
1105         struct net_device *net = NULL;
1106         struct net_device_context *net_device_ctx;
1107         struct netvsc_device_info device_info;
1108         struct netvsc_device *nvdev;
1109         int ret;
1110
1111         net = alloc_etherdev_mq(sizeof(struct net_device_context),
1112                                 num_online_cpus());
1113         if (!net)
1114                 return -ENOMEM;
1115
1116         netif_carrier_off(net);
1117
1118         net_device_ctx = netdev_priv(net);
1119         net_device_ctx->device_ctx = dev;
1120         net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
1121         if (netif_msg_probe(net_device_ctx))
1122                 netdev_dbg(net, "netvsc msg_enable: %d\n",
1123                            net_device_ctx->msg_enable);
1124
1125         net_device_ctx->tx_stats = netdev_alloc_pcpu_stats(struct netvsc_stats);
1126         if (!net_device_ctx->tx_stats) {
1127                 free_netdev(net);
1128                 return -ENOMEM;
1129         }
1130         net_device_ctx->rx_stats = netdev_alloc_pcpu_stats(struct netvsc_stats);
1131         if (!net_device_ctx->rx_stats) {
1132                 free_percpu(net_device_ctx->tx_stats);
1133                 free_netdev(net);
1134                 return -ENOMEM;
1135         }
1136
1137         hv_set_drvdata(dev, net);
1138         INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
1139         INIT_WORK(&net_device_ctx->work, do_set_multicast);
1140
1141         spin_lock_init(&net_device_ctx->lock);
1142         INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
1143
1144         net->netdev_ops = &device_ops;
1145
1146         net->hw_features = NETVSC_HW_FEATURES;
1147         net->features = NETVSC_HW_FEATURES | NETIF_F_HW_VLAN_CTAG_TX;
1148
1149         net->ethtool_ops = &ethtool_ops;
1150         SET_NETDEV_DEV(net, &dev->device);
1151
1152         /* We always need headroom for rndis header */
1153         net->needed_headroom = RNDIS_AND_PPI_SIZE;
1154
1155         /* Notify the netvsc driver of the new device */
1156         memset(&device_info, 0, sizeof(device_info));
1157         device_info.ring_size = ring_size;
1158         device_info.max_num_vrss_chns = max_num_vrss_chns;
1159         ret = rndis_filter_device_add(dev, &device_info);
1160         if (ret != 0) {
1161                 netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
1162                 netvsc_free_netdev(net);
1163                 hv_set_drvdata(dev, NULL);
1164                 return ret;
1165         }
1166         memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
1167
1168         nvdev = hv_get_drvdata(dev);
1169         netif_set_real_num_tx_queues(net, nvdev->num_chn);
1170         netif_set_real_num_rx_queues(net, nvdev->num_chn);
1171
1172         netvsc_init_settings(net);
1173
1174         ret = register_netdev(net);
1175         if (ret != 0) {
1176                 pr_err("Unable to register netdev.\n");
1177                 rndis_filter_device_remove(dev);
1178                 netvsc_free_netdev(net);
1179         }
1180
1181         return ret;
1182 }
1183
1184 static int netvsc_remove(struct hv_device *dev)
1185 {
1186         struct net_device *net;
1187         struct net_device_context *ndev_ctx;
1188         struct netvsc_device *net_device;
1189
1190         net_device = hv_get_drvdata(dev);
1191         net = net_device->ndev;
1192
1193         if (net == NULL) {
1194                 dev_err(&dev->device, "No net device to remove\n");
1195                 return 0;
1196         }
1197
1198         net_device->start_remove = true;
1199
1200         ndev_ctx = netdev_priv(net);
1201         cancel_delayed_work_sync(&ndev_ctx->dwork);
1202         cancel_work_sync(&ndev_ctx->work);
1203
1204         /* Stop outbound asap */
1205         netif_tx_disable(net);
1206
1207         unregister_netdev(net);
1208
1209         /*
1210          * Call to the vsc driver to let it know that the device is being
1211          * removed
1212          */
1213         rndis_filter_device_remove(dev);
1214
1215         netvsc_free_netdev(net);
1216         return 0;
1217 }
1218
1219 static const struct hv_vmbus_device_id id_table[] = {
1220         /* Network guid */
1221         { HV_NIC_GUID, },
1222         { },
1223 };
1224
1225 MODULE_DEVICE_TABLE(vmbus, id_table);
1226
1227 /* The one and only one */
1228 static struct  hv_driver netvsc_drv = {
1229         .name = KBUILD_MODNAME,
1230         .id_table = id_table,
1231         .probe = netvsc_probe,
1232         .remove = netvsc_remove,
1233 };
1234
1235 static void __exit netvsc_drv_exit(void)
1236 {
1237         vmbus_driver_unregister(&netvsc_drv);
1238 }
1239
1240 static int __init netvsc_drv_init(void)
1241 {
1242         if (ring_size < RING_SIZE_MIN) {
1243                 ring_size = RING_SIZE_MIN;
1244                 pr_info("Increased ring_size to %d (min allowed)\n",
1245                         ring_size);
1246         }
1247         return vmbus_driver_register(&netvsc_drv);
1248 }
1249
1250 MODULE_LICENSE("GPL");
1251 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
1252
1253 module_init(netvsc_drv_init);
1254 module_exit(netvsc_drv_exit);