OSCL-LXR linux-6.0.1/​drivers/​net/​hyperv/​netvsc_drv.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2009, Microsoft Corporation.
  *
  * Authors:
  *   Haiyang Zhang <haiyangz@microsoft.com>
  *   Hank Janssen  <hjanssen@microsoft.com>
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/init.h>
 #include <linux/atomic.h>
 #include <linux/ethtool.h>
 #include <linux/module.h>
 #include <linux/highmem.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/delay.h>
 #include <linux/netdevice.h>
 #include <linux/inetdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/pci.h>
 #include <linux/skbuff.h>
 #include <linux/if_vlan.h>
 #include <linux/in.h>
 #include <linux/slab.h>
 #include <linux/rtnetlink.h>
 #include <linux/netpoll.h>
 #include <linux/bpf.h>
 
 #include <net/arp.h>
 #include <net/route.h>
 #include <net/sock.h>
 #include <net/pkt_sched.h>
 #include <net/checksum.h>
 #include <net/ip6_checksum.h>
 
 #include "hyperv_net.h"
 
 #define RING_SIZE_MIN   64
 
 #define LINKCHANGE_INT (2 * HZ)
 #define VF_TAKEOVER_INT (HZ / 10)
 
 static unsigned int ring_size __ro_after_init = 128;
 module_param(ring_size, uint, 0444);
 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
 unsigned int netvsc_ring_bytes __ro_after_init;
 
 static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
                 NETIF_MSG_LINK | NETIF_MSG_IFUP |
                 NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
                 NETIF_MSG_TX_ERR;
 
 static int debug = -1;
 module_param(debug, int, 0444);
 MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
 
 static LIST_HEAD(netvsc_dev_list);
 
 static void netvsc_change_rx_flags(struct net_device *net, int change)
 {
     struct net_device_context *ndev_ctx = netdev_priv(net);
     struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
     int inc;
 
     if (!vf_netdev)
         return;
 
     if (change & IFF_PROMISC) {
         inc = (net->flags & IFF_PROMISC) ? 1 : -1;
         dev_set_promiscuity(vf_netdev, inc);
     }
 
     if (change & IFF_ALLMULTI) {
         inc = (net->flags & IFF_ALLMULTI) ? 1 : -1;
         dev_set_allmulti(vf_netdev, inc);
     }
 }
 
 static void netvsc_set_rx_mode(struct net_device *net)
 {
     struct net_device_context *ndev_ctx = netdev_priv(net);
     struct net_device *vf_netdev;
     struct netvsc_device *nvdev;
 
     rcu_read_lock();
     vf_netdev = rcu_dereference(ndev_ctx->vf_netdev);
     if (vf_netdev) {
         dev_uc_sync(vf_netdev, net);
         dev_mc_sync(vf_netdev, net);
     }
 
     nvdev = rcu_dereference(ndev_ctx->nvdev);
     if (nvdev)
         rndis_filter_update(nvdev);
     rcu_read_unlock();
 }
 
 static void netvsc_tx_enable(struct netvsc_device *nvscdev,
                  struct net_device *ndev)
 {
     nvscdev->tx_disable = false;
     virt_wmb(); /* ensure queue wake up mechanism is on */
 
     netif_tx_wake_all_queues(ndev);
 }
 
 static int netvsc_open(struct net_device *net)
 {
     struct net_device_context *ndev_ctx = netdev_priv(net);
     struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
     struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev);
     struct rndis_device *rdev;
     int ret = 0;
 
     netif_carrier_off(net);
 
     /* Open up the device */
     ret = rndis_filter_open(nvdev);
     if (ret != 0) {
         netdev_err(net, "unable to open device (ret %d).\n", ret);
         return ret;
     }
 
     rdev = nvdev->extension;
     if (!rdev->link_state) {
         netif_carrier_on(net);
         netvsc_tx_enable(nvdev, net);
     }
 
     if (vf_netdev) {
         /* Setting synthetic device up transparently sets
          * slave as up. If open fails, then slave will be
          * still be offline (and not used).
          */
         ret = dev_open(vf_netdev, NULL);
         if (ret)
             netdev_warn(net,
                     "unable to open slave: %s: %d\n",
                     vf_netdev->name, ret);
     }
     return 0;
 }
 
 static int netvsc_wait_until_empty(struct netvsc_device *nvdev)
 {
     unsigned int retry = 0;
     int i;
 
     /* Ensure pending bytes in ring are read */
     for (;;) {
         u32 aread = 0;
 
         for (i = 0; i < nvdev->num_chn; i++) {
             struct vmbus_channel *chn
                 = nvdev->chan_table[i].channel;
 
             if (!chn)
                 continue;
 
             /* make sure receive not running now */
             napi_synchronize(&nvdev->chan_table[i].napi);
 
             aread = hv_get_bytes_to_read(&chn->inbound);
             if (aread)
                 break;
 
             aread = hv_get_bytes_to_read(&chn->outbound);
             if (aread)
                 break;
         }
 
         if (aread == 0)
             return 0;
 
         if (++retry > RETRY_MAX)
             return -ETIMEDOUT;
 
         usleep_range(RETRY_US_LO, RETRY_US_HI);
     }
 }
 
 static void netvsc_tx_disable(struct netvsc_device *nvscdev,
                   struct net_device *ndev)
 {
     if (nvscdev) {
         nvscdev->tx_disable = true;
         virt_wmb(); /* ensure txq will not wake up after stop */
     }
 
     netif_tx_disable(ndev);
 }
 
 static int netvsc_close(struct net_device *net)
 {
     struct net_device_context *net_device_ctx = netdev_priv(net);
     struct net_device *vf_netdev
         = rtnl_dereference(net_device_ctx->vf_netdev);
     struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
     int ret;
 
     netvsc_tx_disable(nvdev, net);
 
     /* No need to close rndis filter if it is removed already */
     if (!nvdev)
         return 0;
 
     ret = rndis_filter_close(nvdev);
     if (ret != 0) {
         netdev_err(net, "unable to close device (ret %d).\n", ret);
         return ret;
     }
 
     ret = netvsc_wait_until_empty(nvdev);
     if (ret)
         netdev_err(net, "Ring buffer not empty after closing rndis\n");
 
     if (vf_netdev)
         dev_close(vf_netdev);
 
     return ret;
 }
 
 static inline void *init_ppi_data(struct rndis_message *msg,
                   u32 ppi_size, u32 pkt_type)
 {
     struct rndis_packet *rndis_pkt = &msg->msg.pkt;
     struct rndis_per_packet_info *ppi;
 
     rndis_pkt->data_offset += ppi_size;
     ppi = (void *)rndis_pkt + rndis_pkt->per_pkt_info_offset
         + rndis_pkt->per_pkt_info_len;
 
     ppi->size = ppi_size;
     ppi->type = pkt_type;
     ppi->internal = 0;
     ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
 
     rndis_pkt->per_pkt_info_len += ppi_size;
 
     return ppi + 1;
 }
 
 static inline int netvsc_get_tx_queue(struct net_device *ndev,
                       struct sk_buff *skb, int old_idx)
 {
     const struct net_device_context *ndc = netdev_priv(ndev);
     struct sock *sk = skb->sk;
     int q_idx;
 
     q_idx = ndc->tx_table[netvsc_get_hash(skb, ndc) &
                   (VRSS_SEND_TAB_SIZE - 1)];
 
     /* If queue index changed record the new value */
     if (q_idx != old_idx &&
         sk && sk_fullsock(sk) && rcu_access_pointer(sk->sk_dst_cache))
         sk_tx_queue_set(sk, q_idx);
 
     return q_idx;
 }
 
 /*
  * Select queue for transmit.
  *
  * If a valid queue has already been assigned, then use that.
  * Otherwise compute tx queue based on hash and the send table.
  *
  * This is basically similar to default (netdev_pick_tx) with the added step
  * of using the host send_table when no other queue has been assigned.
  *
  * TODO support XPS - but get_xps_queue not exported
  */
 static u16 netvsc_pick_tx(struct net_device *ndev, struct sk_buff *skb)
 {
     int q_idx = sk_tx_queue_get(skb->sk);
 
     if (q_idx < 0 || skb->ooo_okay || q_idx >= ndev->real_num_tx_queues) {
         /* If forwarding a packet, we use the recorded queue when
          * available for better cache locality.
          */
         if (skb_rx_queue_recorded(skb))
             q_idx = skb_get_rx_queue(skb);
         else
             q_idx = netvsc_get_tx_queue(ndev, skb, q_idx);
     }
 
     return q_idx;
 }
 
 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
                    struct net_device *sb_dev)
 {
     struct net_device_context *ndc = netdev_priv(ndev);
     struct net_device *vf_netdev;
     u16 txq;
 
     rcu_read_lock();
     vf_netdev = rcu_dereference(ndc->vf_netdev);
     if (vf_netdev) {
         const struct net_device_ops *vf_ops = vf_netdev->netdev_ops;
 
         if (vf_ops->ndo_select_queue)
             txq = vf_ops->ndo_select_queue(vf_netdev, skb, sb_dev);
         else
             txq = netdev_pick_tx(vf_netdev, skb, NULL);
 
         /* Record the queue selected by VF so that it can be
          * used for common case where VF has more queues than
          * the synthetic device.
          */
         qdisc_skb_cb(skb)->slave_dev_queue_mapping = txq;
     } else {
         txq = netvsc_pick_tx(ndev, skb);
     }
     rcu_read_unlock();
 
     while (txq >= ndev->real_num_tx_queues)
         txq -= ndev->real_num_tx_queues;
 
     return txq;
 }
 
 static u32 fill_pg_buf(unsigned long hvpfn, u32 offset, u32 len,
                struct hv_page_buffer *pb)
 {
     int j = 0;
 
     hvpfn += offset >> HV_HYP_PAGE_SHIFT;
     offset = offset & ~HV_HYP_PAGE_MASK;
 
     while (len > 0) {
         unsigned long bytes;
 
         bytes = HV_HYP_PAGE_SIZE - offset;
         if (bytes > len)
             bytes = len;
         pb[j].pfn = hvpfn;
         pb[j].offset = offset;
         pb[j].len = bytes;
 
         offset += bytes;
         len -= bytes;
 
         if (offset == HV_HYP_PAGE_SIZE && len) {
             hvpfn++;
             offset = 0;
             j++;
         }
     }
 
     return j + 1;
 }
 
 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
                struct hv_netvsc_packet *packet,
                struct hv_page_buffer *pb)
 {
     u32 slots_used = 0;
     char *data = skb->data;
     int frags = skb_shinfo(skb)->nr_frags;
     int i;
 
     /* The packet is laid out thus:
      * 1. hdr: RNDIS header and PPI
      * 2. skb linear data
      * 3. skb fragment data
      */
     slots_used += fill_pg_buf(virt_to_hvpfn(hdr),
                   offset_in_hvpage(hdr),
                   len,
                   &pb[slots_used]);
 
     packet->rmsg_size = len;
     packet->rmsg_pgcnt = slots_used;
 
     slots_used += fill_pg_buf(virt_to_hvpfn(data),
                   offset_in_hvpage(data),
                   skb_headlen(skb),
                   &pb[slots_used]);
 
     for (i = 0; i < frags; i++) {
         skb_frag_t *frag = skb_shinfo(skb)->frags + i;
 
         slots_used += fill_pg_buf(page_to_hvpfn(skb_frag_page(frag)),
                       skb_frag_off(frag),
                       skb_frag_size(frag),
                       &pb[slots_used]);
     }
     return slots_used;
 }
 
 static int count_skb_frag_slots(struct sk_buff *skb)
 {
     int i, frags = skb_shinfo(skb)->nr_frags;
     int pages = 0;
 
     for (i = 0; i < frags; i++) {
         skb_frag_t *frag = skb_shinfo(skb)->frags + i;
         unsigned long size = skb_frag_size(frag);
         unsigned long offset = skb_frag_off(frag);
 
         /* Skip unused frames from start of page */
         offset &= ~HV_HYP_PAGE_MASK;
         pages += HVPFN_UP(offset + size);
     }
     return pages;
 }
 
 static int netvsc_get_slots(struct sk_buff *skb)
 {
     char *data = skb->data;
     unsigned int offset = offset_in_hvpage(data);
     unsigned int len = skb_headlen(skb);
     int slots;
     int frag_slots;
 
     slots = DIV_ROUND_UP(offset + len, HV_HYP_PAGE_SIZE);
     frag_slots = count_skb_frag_slots(skb);
     return slots + frag_slots;
 }
 
 static u32 net_checksum_info(struct sk_buff *skb)
 {
     if (skb->protocol == htons(ETH_P_IP)) {
         struct iphdr *ip = ip_hdr(skb);
 
         if (ip->protocol == IPPROTO_TCP)
             return TRANSPORT_INFO_IPV4_TCP;
         else if (ip->protocol == IPPROTO_UDP)
             return TRANSPORT_INFO_IPV4_UDP;
     } else {
         struct ipv6hdr *ip6 = ipv6_hdr(skb);
 
         if (ip6->nexthdr == IPPROTO_TCP)
             return TRANSPORT_INFO_IPV6_TCP;
         else if (ip6->nexthdr == IPPROTO_UDP)
             return TRANSPORT_INFO_IPV6_UDP;
     }
 
     return TRANSPORT_INFO_NOT_IP;
 }
 
 /* Send skb on the slave VF device. */
 static int netvsc_vf_xmit(struct net_device *net, struct net_device *vf_netdev,
               struct sk_buff *skb)
 {
     struct net_device_context *ndev_ctx = netdev_priv(net);
     unsigned int len = skb->len;
     int rc;
 
     skb->dev = vf_netdev;
     skb_record_rx_queue(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
 
     rc = dev_queue_xmit(skb);
     if (likely(rc == NET_XMIT_SUCCESS || rc == NET_XMIT_CN)) {
         struct netvsc_vf_pcpu_stats *pcpu_stats
             = this_cpu_ptr(ndev_ctx->vf_stats);
 
         u64_stats_update_begin(&pcpu_stats->syncp);
         pcpu_stats->tx_packets++;
         pcpu_stats->tx_bytes += len;
         u64_stats_update_end(&pcpu_stats->syncp);
     } else {
         this_cpu_inc(ndev_ctx->vf_stats->tx_dropped);
     }
 
     return rc;
 }
 
 static int netvsc_xmit(struct sk_buff *skb, struct net_device *net, bool xdp_tx)
 {
     struct net_device_context *net_device_ctx = netdev_priv(net);
     struct hv_netvsc_packet *packet = NULL;
     int ret;
     unsigned int num_data_pgs;
     struct rndis_message *rndis_msg;
     struct net_device *vf_netdev;
     u32 rndis_msg_size;
     u32 hash;
     struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT];
 
     /* If VF is present and up then redirect packets to it.
      * Skip the VF if it is marked down or has no carrier.
      * If netpoll is in uses, then VF can not be used either.
      */
     vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev);
     if (vf_netdev && netif_running(vf_netdev) &&
         netif_carrier_ok(vf_netdev) && !netpoll_tx_running(net) &&
         net_device_ctx->data_path_is_vf)
         return netvsc_vf_xmit(net, vf_netdev, skb);
 
     /* We will atmost need two pages to describe the rndis
      * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
      * of pages in a single packet. If skb is scattered around
      * more pages we try linearizing it.
      */
 
     num_data_pgs = netvsc_get_slots(skb) + 2;
 
     if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) {
         ++net_device_ctx->eth_stats.tx_scattered;
 
         if (skb_linearize(skb))
             goto no_memory;
 
         num_data_pgs = netvsc_get_slots(skb) + 2;
         if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
             ++net_device_ctx->eth_stats.tx_too_big;
             goto drop;
         }
     }
 
     /*
      * Place the rndis header in the skb head room and
      * the skb->cb will be used for hv_netvsc_packet
      * structure.
      */
     ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
     if (ret)
         goto no_memory;
 
     /* Use the skb control buffer for building up the packet */
     BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
             sizeof_field(struct sk_buff, cb));
     packet = (struct hv_netvsc_packet *)skb->cb;
 
     packet->q_idx = skb_get_queue_mapping(skb);
 
     packet->total_data_buflen = skb->len;
     packet->total_bytes = skb->len;
     packet->total_packets = 1;
 
     rndis_msg = (struct rndis_message *)skb->head;
 
     /* Add the rndis header */
     rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
     rndis_msg->msg_len = packet->total_data_buflen;
 
     rndis_msg->msg.pkt = (struct rndis_packet) {
         .data_offset = sizeof(struct rndis_packet),
         .data_len = packet->total_data_buflen,
         .per_pkt_info_offset = sizeof(struct rndis_packet),
     };
 
     rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
 
     hash = skb_get_hash_raw(skb);
     if (hash != 0 && net->real_num_tx_queues > 1) {
         u32 *hash_info;
 
         rndis_msg_size += NDIS_HASH_PPI_SIZE;
         hash_info = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
                       NBL_HASH_VALUE);
         *hash_info = hash;
     }
 
     /* When using AF_PACKET we need to drop VLAN header from
      * the frame and update the SKB to allow the HOST OS
      * to transmit the 802.1Q packet
      */
     if (skb->protocol == htons(ETH_P_8021Q)) {
         u16 vlan_tci;
 
         skb_reset_mac_header(skb);
         if (eth_type_vlan(eth_hdr(skb)->h_proto)) {
             if (unlikely(__skb_vlan_pop(skb, &vlan_tci) != 0)) {
                 ++net_device_ctx->eth_stats.vlan_error;
                 goto drop;
             }
 
             __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tci);
             /* Update the NDIS header pkt lengths */
             packet->total_data_buflen -= VLAN_HLEN;
             packet->total_bytes -= VLAN_HLEN;
             rndis_msg->msg_len = packet->total_data_buflen;
             rndis_msg->msg.pkt.data_len = packet->total_data_buflen;
         }
     }
 
     if (skb_vlan_tag_present(skb)) {
         struct ndis_pkt_8021q_info *vlan;
 
         rndis_msg_size += NDIS_VLAN_PPI_SIZE;
         vlan = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
                      IEEE_8021Q_INFO);
 
         vlan->value = 0;
         vlan->vlanid = skb_vlan_tag_get_id(skb);
         vlan->cfi = skb_vlan_tag_get_cfi(skb);
         vlan->pri = skb_vlan_tag_get_prio(skb);
     }
 
     if (skb_is_gso(skb)) {
         struct ndis_tcp_lso_info *lso_info;
 
         rndis_msg_size += NDIS_LSO_PPI_SIZE;
         lso_info = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
                      TCP_LARGESEND_PKTINFO);
 
         lso_info->value = 0;
         lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
         if (skb->protocol == htons(ETH_P_IP)) {
             lso_info->lso_v2_transmit.ip_version =
                 NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
             ip_hdr(skb)->tot_len = 0;
             ip_hdr(skb)->check = 0;
             tcp_hdr(skb)->check =
                 ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
                            ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
         } else {
             lso_info->lso_v2_transmit.ip_version =
                 NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
             tcp_v6_gso_csum_prep(skb);
         }
         lso_info->lso_v2_transmit.tcp_header_offset = skb_transport_offset(skb);
         lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
     } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
         if (net_checksum_info(skb) & net_device_ctx->tx_checksum_mask) {
             struct ndis_tcp_ip_checksum_info *csum_info;
 
             rndis_msg_size += NDIS_CSUM_PPI_SIZE;
             csum_info = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
                           TCPIP_CHKSUM_PKTINFO);
 
             csum_info->value = 0;
             csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
 
             if (skb->protocol == htons(ETH_P_IP)) {
                 csum_info->transmit.is_ipv4 = 1;
 
                 if (ip_hdr(skb)->protocol == IPPROTO_TCP)
                     csum_info->transmit.tcp_checksum = 1;
                 else
                     csum_info->transmit.udp_checksum = 1;
             } else {
                 csum_info->transmit.is_ipv6 = 1;
 
                 if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
                     csum_info->transmit.tcp_checksum = 1;
                 else
                     csum_info->transmit.udp_checksum = 1;
             }
         } else {
             /* Can't do offload of this type of checksum */
             if (skb_checksum_help(skb))
                 goto drop;
         }
     }
 
     /* Start filling in the page buffers with the rndis hdr */
     rndis_msg->msg_len += rndis_msg_size;
     packet->total_data_buflen = rndis_msg->msg_len;
     packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
                            skb, packet, pb);
 
     /* timestamp packet in software */
     skb_tx_timestamp(skb);
 
     ret = netvsc_send(net, packet, rndis_msg, pb, skb, xdp_tx);
     if (likely(ret == 0))
         return NETDEV_TX_OK;
 
     if (ret == -EAGAIN) {
         ++net_device_ctx->eth_stats.tx_busy;
         return NETDEV_TX_BUSY;
     }
 
     if (ret == -ENOSPC)
         ++net_device_ctx->eth_stats.tx_no_space;
 
 drop:
     dev_kfree_skb_any(skb);
     net->stats.tx_dropped++;
 
     return NETDEV_TX_OK;
 
 no_memory:
     ++net_device_ctx->eth_stats.tx_no_memory;
     goto drop;
 }
 
 static netdev_tx_t netvsc_start_xmit(struct sk_buff *skb,
                      struct net_device *ndev)
 {
     return netvsc_xmit(skb, ndev, false);
 }
 
 /*
  * netvsc_linkstatus_callback - Link up/down notification
  */
 void netvsc_linkstatus_callback(struct net_device *net,
                 struct rndis_message *resp,
                 void *data, u32 data_buflen)
 {
     struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
     struct net_device_context *ndev_ctx = netdev_priv(net);
     struct netvsc_reconfig *event;
     unsigned long flags;
 
     /* Ensure the packet is big enough to access its fields */
     if (resp->msg_len - RNDIS_HEADER_SIZE < sizeof(struct rndis_indicate_status)) {
         netdev_err(net, "invalid rndis_indicate_status packet, len: %u\n",
                resp->msg_len);
         return;
     }
 
     /* Copy the RNDIS indicate status into nvchan->recv_buf */
     memcpy(indicate, data + RNDIS_HEADER_SIZE, sizeof(*indicate));
 
     /* Update the physical link speed when changing to another vSwitch */
     if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
         u32 speed;
 
         /* Validate status_buf_offset and status_buflen.
          *
          * Certain (pre-Fe) implementations of Hyper-V's vSwitch didn't account
          * for the status buffer field in resp->msg_len; perform the validation
          * using data_buflen (>= resp->msg_len).
          */
         if (indicate->status_buflen < sizeof(speed) ||
             indicate->status_buf_offset < sizeof(*indicate) ||
             data_buflen - RNDIS_HEADER_SIZE < indicate->status_buf_offset ||
             data_buflen - RNDIS_HEADER_SIZE - indicate->status_buf_offset
                 < indicate->status_buflen) {
             netdev_err(net, "invalid rndis_indicate_status packet\n");
             return;
         }
 
         speed = *(u32 *)(data + RNDIS_HEADER_SIZE + indicate->status_buf_offset) / 10000;
         ndev_ctx->speed = speed;
         return;
     }
 
     /* Handle these link change statuses below */
     if (indicate->status != RNDIS_STATUS_NETWORK_CHANGE &&
         indicate->status != RNDIS_STATUS_MEDIA_CONNECT &&
         indicate->status != RNDIS_STATUS_MEDIA_DISCONNECT)
         return;
 
     if (net->reg_state != NETREG_REGISTERED)
         return;
 
     event = kzalloc(sizeof(*event), GFP_ATOMIC);
     if (!event)
         return;
     event->event = indicate->status;
 
     spin_lock_irqsave(&ndev_ctx->lock, flags);
     list_add_tail(&event->list, &ndev_ctx->reconfig_events);
     spin_unlock_irqrestore(&ndev_ctx->lock, flags);
 
     schedule_delayed_work(&ndev_ctx->dwork, 0);
 }
 
 /* This function should only be called after skb_record_rx_queue() */
 void netvsc_xdp_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
     int rc;
 
     skb->queue_mapping = skb_get_rx_queue(skb);
     __skb_push(skb, ETH_HLEN);
 
     rc = netvsc_xmit(skb, ndev, true);
 
     if (dev_xmit_complete(rc))
         return;
 
     dev_kfree_skb_any(skb);
     ndev->stats.tx_dropped++;
 }
 
 static void netvsc_comp_ipcsum(struct sk_buff *skb)
 {
     struct iphdr *iph = (struct iphdr *)skb->data;
 
     iph->check = 0;
     iph->check = ip_fast_csum(iph, iph->ihl);
 }
 
 static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net,
                          struct netvsc_channel *nvchan,
                          struct xdp_buff *xdp)
 {
     struct napi_struct *napi = &nvchan->napi;
     const struct ndis_pkt_8021q_info *vlan = &nvchan->rsc.vlan;
     const struct ndis_tcp_ip_checksum_info *csum_info =
                         &nvchan->rsc.csum_info;
     const u32 *hash_info = &nvchan->rsc.hash_info;
     u8 ppi_flags = nvchan->rsc.ppi_flags;
     struct sk_buff *skb;
     void *xbuf = xdp->data_hard_start;
     int i;
 
     if (xbuf) {
         unsigned int hdroom = xdp->data - xdp->data_hard_start;
         unsigned int xlen = xdp->data_end - xdp->data;
         unsigned int frag_size = xdp->frame_sz;
 
         skb = build_skb(xbuf, frag_size);
 
         if (!skb) {
             __free_page(virt_to_page(xbuf));
             return NULL;
         }
 
         skb_reserve(skb, hdroom);
         skb_put(skb, xlen);
         skb->dev = napi->dev;
     } else {
         skb = napi_alloc_skb(napi, nvchan->rsc.pktlen);
 
         if (!skb)
             return NULL;
 
         /* Copy to skb. This copy is needed here since the memory
          * pointed by hv_netvsc_packet cannot be deallocated.
          */
         for (i = 0; i < nvchan->rsc.cnt; i++)
             skb_put_data(skb, nvchan->rsc.data[i],
                      nvchan->rsc.len[i]);
     }
 
     skb->protocol = eth_type_trans(skb, net);
 
     /* skb is already created with CHECKSUM_NONE */
     skb_checksum_none_assert(skb);
 
     /* Incoming packets may have IP header checksum verified by the host.
      * They may not have IP header checksum computed after coalescing.
      * We compute it here if the flags are set, because on Linux, the IP
      * checksum is always checked.
      */
     if ((ppi_flags & NVSC_RSC_CSUM_INFO) && csum_info->receive.ip_checksum_value_invalid &&
         csum_info->receive.ip_checksum_succeeded &&
         skb->protocol == htons(ETH_P_IP)) {
         /* Check that there is enough space to hold the IP header. */
         if (skb_headlen(skb) < sizeof(struct iphdr)) {
             kfree_skb(skb);
             return NULL;
         }
         netvsc_comp_ipcsum(skb);
     }
 
     /* Do L4 checksum offload if enabled and present. */
     if ((ppi_flags & NVSC_RSC_CSUM_INFO) && (net->features & NETIF_F_RXCSUM)) {
         if (csum_info->receive.tcp_checksum_succeeded ||
             csum_info->receive.udp_checksum_succeeded)
             skb->ip_summed = CHECKSUM_UNNECESSARY;
     }
 
     if ((ppi_flags & NVSC_RSC_HASH_INFO) && (net->features & NETIF_F_RXHASH))
         skb_set_hash(skb, *hash_info, PKT_HASH_TYPE_L4);
 
     if (ppi_flags & NVSC_RSC_VLAN) {
         u16 vlan_tci = vlan->vlanid | (vlan->pri << VLAN_PRIO_SHIFT) |
             (vlan->cfi ? VLAN_CFI_MASK : 0);
 
         __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
                        vlan_tci);
     }
 
     return skb;
 }
 
 /*
  * netvsc_recv_callback -  Callback when we receive a packet from the
  * "wire" on the specified device.
  */
 int netvsc_recv_callback(struct net_device *net,
              struct netvsc_device *net_device,
              struct netvsc_channel *nvchan)
 {
     struct net_device_context *net_device_ctx = netdev_priv(net);
     struct vmbus_channel *channel = nvchan->channel;
     u16 q_idx = channel->offermsg.offer.sub_channel_index;
     struct sk_buff *skb;
     struct netvsc_stats_rx *rx_stats = &nvchan->rx_stats;
     struct xdp_buff xdp;
     u32 act;
 
     if (net->reg_state != NETREG_REGISTERED)
         return NVSP_STAT_FAIL;
 
     act = netvsc_run_xdp(net, nvchan, &xdp);
 
     if (act == XDP_REDIRECT)
         return NVSP_STAT_SUCCESS;
 
     if (act != XDP_PASS && act != XDP_TX) {
         u64_stats_update_begin(&rx_stats->syncp);
         rx_stats->xdp_drop++;
         u64_stats_update_end(&rx_stats->syncp);
 
         return NVSP_STAT_SUCCESS; /* consumed by XDP */
     }
 
     /* Allocate a skb - TODO direct I/O to pages? */
     skb = netvsc_alloc_recv_skb(net, nvchan, &xdp);
 
     if (unlikely(!skb)) {
         ++net_device_ctx->eth_stats.rx_no_memory;
         return NVSP_STAT_FAIL;
     }
 
     skb_record_rx_queue(skb, q_idx);
 
     /*
      * Even if injecting the packet, record the statistics
      * on the synthetic device because modifying the VF device
      * statistics will not work correctly.
      */
     u64_stats_update_begin(&rx_stats->syncp);
     if (act == XDP_TX)
         rx_stats->xdp_tx++;
 
     rx_stats->packets++;
     rx_stats->bytes += nvchan->rsc.pktlen;
 
     if (skb->pkt_type == PACKET_BROADCAST)
         ++rx_stats->broadcast;
     else if (skb->pkt_type == PACKET_MULTICAST)
         ++rx_stats->multicast;
     u64_stats_update_end(&rx_stats->syncp);
 
     if (act == XDP_TX) {
         netvsc_xdp_xmit(skb, net);
         return NVSP_STAT_SUCCESS;
     }
 
     napi_gro_receive(&nvchan->napi, skb);
     return NVSP_STAT_SUCCESS;
 }
 
 static void netvsc_get_drvinfo(struct net_device *net,
                    struct ethtool_drvinfo *info)
 {
     strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
     strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 }
 
 static void netvsc_get_channels(struct net_device *net,
                 struct ethtool_channels *channel)
 {
     struct net_device_context *net_device_ctx = netdev_priv(net);
     struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
 
     if (nvdev) {
         channel->max_combined   = nvdev->max_chn;
         channel->combined_count = nvdev->num_chn;
     }
 }
 
 /* Alloc struct netvsc_device_info, and initialize it from either existing
  * struct netvsc_device, or from default values.
  */
 static
 struct netvsc_device_info *netvsc_devinfo_get(struct netvsc_device *nvdev)
 {
     struct netvsc_device_info *dev_info;
     struct bpf_prog *prog;
 
     dev_info = kzalloc(sizeof(*dev_info), GFP_ATOMIC);
 
     if (!dev_info)
         return NULL;
 
     if (nvdev) {
         ASSERT_RTNL();
 
         dev_info->num_chn = nvdev->num_chn;
         dev_info->send_sections = nvdev->send_section_cnt;
         dev_info->send_section_size = nvdev->send_section_size;
         dev_info->recv_sections = nvdev->recv_section_cnt;
         dev_info->recv_section_size = nvdev->recv_section_size;
 
         memcpy(dev_info->rss_key, nvdev->extension->rss_key,
                NETVSC_HASH_KEYLEN);
 
         prog = netvsc_xdp_get(nvdev);
         if (prog) {
             bpf_prog_inc(prog);
             dev_info->bprog = prog;
         }
     } else {
         dev_info->num_chn = VRSS_CHANNEL_DEFAULT;
         dev_info->send_sections = NETVSC_DEFAULT_TX;
         dev_info->send_section_size = NETVSC_SEND_SECTION_SIZE;
         dev_info->recv_sections = NETVSC_DEFAULT_RX;
         dev_info->recv_section_size = NETVSC_RECV_SECTION_SIZE;
     }
 
     return dev_info;
 }
 
 /* Free struct netvsc_device_info */
 static void netvsc_devinfo_put(struct netvsc_device_info *dev_info)
 {
     if (dev_info->bprog) {
         ASSERT_RTNL();
         bpf_prog_put(dev_info->bprog);
     }
 
     kfree(dev_info);
 }
 
 static int netvsc_detach(struct net_device *ndev,
              struct netvsc_device *nvdev)
 {
     struct net_device_context *ndev_ctx = netdev_priv(ndev);
     struct hv_device *hdev = ndev_ctx->device_ctx;
     int ret;
 
     /* Don't try continuing to try and setup sub channels */
     if (cancel_work_sync(&nvdev->subchan_work))
         nvdev->num_chn = 1;
 
     netvsc_xdp_set(ndev, NULL, NULL, nvdev);
 
     /* If device was up (receiving) then shutdown */
     if (netif_running(ndev)) {
         netvsc_tx_disable(nvdev, ndev);
 
         ret = rndis_filter_close(nvdev);
         if (ret) {
             netdev_err(ndev,
                    "unable to close device (ret %d).\n", ret);
             return ret;
         }
 
         ret = netvsc_wait_until_empty(nvdev);
         if (ret) {
             netdev_err(ndev,
                    "Ring buffer not empty after closing rndis\n");
             return ret;
         }
     }
 
     netif_device_detach(ndev);
 
     rndis_filter_device_remove(hdev, nvdev);
 
     return 0;
 }
 
 static int netvsc_attach(struct net_device *ndev,
              struct netvsc_device_info *dev_info)
 {
     struct net_device_context *ndev_ctx = netdev_priv(ndev);
     struct hv_device *hdev = ndev_ctx->device_ctx;
     struct netvsc_device *nvdev;
     struct rndis_device *rdev;
     struct bpf_prog *prog;
     int ret = 0;
 
     nvdev = rndis_filter_device_add(hdev, dev_info);
     if (IS_ERR(nvdev))
         return PTR_ERR(nvdev);
 
     if (nvdev->num_chn > 1) {
         ret = rndis_set_subchannel(ndev, nvdev, dev_info);
 
         /* if unavailable, just proceed with one queue */
         if (ret) {
             nvdev->max_chn = 1;
             nvdev->num_chn = 1;
         }
     }
 
     prog = dev_info->bprog;
     if (prog) {
         bpf_prog_inc(prog);
         ret = netvsc_xdp_set(ndev, prog, NULL, nvdev);
         if (ret) {
             bpf_prog_put(prog);
             goto err1;
         }
     }
 
     /* In any case device is now ready */
     nvdev->tx_disable = false;
     netif_device_attach(ndev);
 
     /* Note: enable and attach happen when sub-channels setup */
     netif_carrier_off(ndev);
 
     if (netif_running(ndev)) {
         ret = rndis_filter_open(nvdev);
         if (ret)
             goto err2;
 
         rdev = nvdev->extension;
         if (!rdev->link_state)
             netif_carrier_on(ndev);
     }
 
     return 0;
 
 err2:
     netif_device_detach(ndev);
 
 err1:
     rndis_filter_device_remove(hdev, nvdev);
 
     return ret;
 }
 
 static int netvsc_set_channels(struct net_device *net,
                    struct ethtool_channels *channels)
 {
     struct net_device_context *net_device_ctx = netdev_priv(net);
     struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev);
     unsigned int orig, count = channels->combined_count;
     struct netvsc_device_info *device_info;
     int ret;
 
     /* We do not support separate count for rx, tx, or other */
     if (count == 0 ||
         channels->rx_count || channels->tx_count || channels->other_count)
         return -EINVAL;
 
     if (!nvdev || nvdev->destroy)
         return -ENODEV;
 
     if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5)
         return -EINVAL;
 
     if (count > nvdev->max_chn)
         return -EINVAL;
 
     orig = nvdev->num_chn;
 
     device_info = netvsc_devinfo_get(nvdev);
 
     if (!device_info)
         return -ENOMEM;
 
     device_info->num_chn = count;
 
     ret = netvsc_detach(net, nvdev);
     if (ret)
         goto out;
 
     ret = netvsc_attach(net, device_info);
     if (ret) {
         device_info->num_chn = orig;
         if (netvsc_attach(net, device_info))
             netdev_err(net, "restoring channel setting failed\n");
     }
 
 out:
     netvsc_devinfo_put(device_info);
     return ret;
 }
 
 static void netvsc_init_settings(struct net_device *dev)
 {
     struct net_device_context *ndc = netdev_priv(dev);
 
     ndc->l4_hash = HV_DEFAULT_L4HASH;
 
     ndc->speed = SPEED_UNKNOWN;
     ndc->duplex = DUPLEX_FULL;
 
     dev->features = NETIF_F_LRO;
 }
 
 static int netvsc_get_link_ksettings(struct net_device *dev,
                      struct ethtool_link_ksettings *cmd)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct net_device *vf_netdev;
 
     vf_netdev = rtnl_dereference(ndc->vf_netdev);
 
     if (vf_netdev)
         return __ethtool_get_link_ksettings(vf_netdev, cmd);
 
     cmd->base.speed = ndc->speed;
     cmd->base.duplex = ndc->duplex;
     cmd->base.port = PORT_OTHER;
 
     return 0;
 }
 
 static int netvsc_set_link_ksettings(struct net_device *dev,
                      const struct ethtool_link_ksettings *cmd)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
 
     if (vf_netdev) {
         if (!vf_netdev->ethtool_ops->set_link_ksettings)
             return -EOPNOTSUPP;
 
         return vf_netdev->ethtool_ops->set_link_ksettings(vf_netdev,
                                   cmd);
     }
 
     return ethtool_virtdev_set_link_ksettings(dev, cmd,
                           &ndc->speed, &ndc->duplex);
 }
 
 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 {
     struct net_device_context *ndevctx = netdev_priv(ndev);
     struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
     struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
     int orig_mtu = ndev->mtu;
     struct netvsc_device_info *device_info;
     int ret = 0;
 
     if (!nvdev || nvdev->destroy)
         return -ENODEV;
 
     device_info = netvsc_devinfo_get(nvdev);
 
     if (!device_info)
         return -ENOMEM;
 
     /* Change MTU of underlying VF netdev first. */
     if (vf_netdev) {
         ret = dev_set_mtu(vf_netdev, mtu);
         if (ret)
             goto out;
     }
 
     ret = netvsc_detach(ndev, nvdev);
     if (ret)
         goto rollback_vf;
 
     ndev->mtu = mtu;
 
     ret = netvsc_attach(ndev, device_info);
     if (!ret)
         goto out;
 
     /* Attempt rollback to original MTU */
     ndev->mtu = orig_mtu;
 
     if (netvsc_attach(ndev, device_info))
         netdev_err(ndev, "restoring mtu failed\n");
 rollback_vf:
     if (vf_netdev)
         dev_set_mtu(vf_netdev, orig_mtu);
 
 out:
     netvsc_devinfo_put(device_info);
     return ret;
 }
 
 static void netvsc_get_vf_stats(struct net_device *net,
                 struct netvsc_vf_pcpu_stats *tot)
 {
     struct net_device_context *ndev_ctx = netdev_priv(net);
     int i;
 
     memset(tot, 0, sizeof(*tot));
 
     for_each_possible_cpu(i) {
         const struct netvsc_vf_pcpu_stats *stats
             = per_cpu_ptr(ndev_ctx->vf_stats, i);
         u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
         unsigned int start;
 
         do {
             start = u64_stats_fetch_begin_irq(&stats->syncp);
             rx_packets = stats->rx_packets;
             tx_packets = stats->tx_packets;
             rx_bytes = stats->rx_bytes;
             tx_bytes = stats->tx_bytes;
         } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
 
         tot->rx_packets += rx_packets;
         tot->tx_packets += tx_packets;
         tot->rx_bytes   += rx_bytes;
         tot->tx_bytes   += tx_bytes;
         tot->tx_dropped += stats->tx_dropped;
     }
 }
 
 static void netvsc_get_pcpu_stats(struct net_device *net,
                   struct netvsc_ethtool_pcpu_stats *pcpu_tot)
 {
     struct net_device_context *ndev_ctx = netdev_priv(net);
     struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
     int i;
 
     /* fetch percpu stats of vf */
     for_each_possible_cpu(i) {
         const struct netvsc_vf_pcpu_stats *stats =
             per_cpu_ptr(ndev_ctx->vf_stats, i);
         struct netvsc_ethtool_pcpu_stats *this_tot = &pcpu_tot[i];
         unsigned int start;
 
         do {
             start = u64_stats_fetch_begin_irq(&stats->syncp);
             this_tot->vf_rx_packets = stats->rx_packets;
             this_tot->vf_tx_packets = stats->tx_packets;
             this_tot->vf_rx_bytes = stats->rx_bytes;
             this_tot->vf_tx_bytes = stats->tx_bytes;
         } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
         this_tot->rx_packets = this_tot->vf_rx_packets;
         this_tot->tx_packets = this_tot->vf_tx_packets;
         this_tot->rx_bytes   = this_tot->vf_rx_bytes;
         this_tot->tx_bytes   = this_tot->vf_tx_bytes;
     }
 
     /* fetch percpu stats of netvsc */
     for (i = 0; i < nvdev->num_chn; i++) {
         const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
         const struct netvsc_stats_tx *tx_stats;
         const struct netvsc_stats_rx *rx_stats;
         struct netvsc_ethtool_pcpu_stats *this_tot =
             &pcpu_tot[nvchan->channel->target_cpu];
         u64 packets, bytes;
         unsigned int start;
 
         tx_stats = &nvchan->tx_stats;
         do {
             start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
             packets = tx_stats->packets;
             bytes = tx_stats->bytes;
         } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
 
         this_tot->tx_bytes  += bytes;
         this_tot->tx_packets    += packets;
 
         rx_stats = &nvchan->rx_stats;
         do {
             start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
             packets = rx_stats->packets;
             bytes = rx_stats->bytes;
         } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
 
         this_tot->rx_bytes  += bytes;
         this_tot->rx_packets    += packets;
     }
 }
 
 static void netvsc_get_stats64(struct net_device *net,
                    struct rtnl_link_stats64 *t)
 {
     struct net_device_context *ndev_ctx = netdev_priv(net);
     struct netvsc_device *nvdev;
     struct netvsc_vf_pcpu_stats vf_tot;
     int i;
 
     rcu_read_lock();
 
     nvdev = rcu_dereference(ndev_ctx->nvdev);
     if (!nvdev)
         goto out;
 
     netdev_stats_to_stats64(t, &net->stats);
 
     netvsc_get_vf_stats(net, &vf_tot);
     t->rx_packets += vf_tot.rx_packets;
     t->tx_packets += vf_tot.tx_packets;
     t->rx_bytes   += vf_tot.rx_bytes;
     t->tx_bytes   += vf_tot.tx_bytes;
     t->tx_dropped += vf_tot.tx_dropped;
 
     for (i = 0; i < nvdev->num_chn; i++) {
         const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
         const struct netvsc_stats_tx *tx_stats;
         const struct netvsc_stats_rx *rx_stats;
         u64 packets, bytes, multicast;
         unsigned int start;
 
         tx_stats = &nvchan->tx_stats;
         do {
             start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
             packets = tx_stats->packets;
             bytes = tx_stats->bytes;
         } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
 
         t->tx_bytes += bytes;
         t->tx_packets   += packets;
 
         rx_stats = &nvchan->rx_stats;
         do {
             start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
             packets = rx_stats->packets;
             bytes = rx_stats->bytes;
             multicast = rx_stats->multicast + rx_stats->broadcast;
         } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
 
         t->rx_bytes += bytes;
         t->rx_packets   += packets;
         t->multicast    += multicast;
     }
 out:
     rcu_read_unlock();
 }
 
 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
 {
     struct net_device_context *ndc = netdev_priv(ndev);
     struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
     struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
     struct sockaddr *addr = p;
     int err;
 
     err = eth_prepare_mac_addr_change(ndev, p);
     if (err)
         return err;
 
     if (!nvdev)
         return -ENODEV;
 
     if (vf_netdev) {
         err = dev_set_mac_address(vf_netdev, addr, NULL);
         if (err)
             return err;
     }
 
     err = rndis_filter_set_device_mac(nvdev, addr->sa_data);
     if (!err) {
         eth_commit_mac_addr_change(ndev, p);
     } else if (vf_netdev) {
         /* rollback change on VF */
         memcpy(addr->sa_data, ndev->dev_addr, ETH_ALEN);
         dev_set_mac_address(vf_netdev, addr, NULL);
     }
 
     return err;
 }
 
 static const struct {
     char name[ETH_GSTRING_LEN];
     u16 offset;
 } netvsc_stats[] = {
     { "tx_scattered", offsetof(struct netvsc_ethtool_stats, tx_scattered) },
     { "tx_no_memory", offsetof(struct netvsc_ethtool_stats, tx_no_memory) },
     { "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
     { "tx_too_big",   offsetof(struct netvsc_ethtool_stats, tx_too_big) },
     { "tx_busy",      offsetof(struct netvsc_ethtool_stats, tx_busy) },
     { "tx_send_full", offsetof(struct netvsc_ethtool_stats, tx_send_full) },
     { "rx_comp_busy", offsetof(struct netvsc_ethtool_stats, rx_comp_busy) },
     { "rx_no_memory", offsetof(struct netvsc_ethtool_stats, rx_no_memory) },
     { "stop_queue", offsetof(struct netvsc_ethtool_stats, stop_queue) },
     { "wake_queue", offsetof(struct netvsc_ethtool_stats, wake_queue) },
     { "vlan_error", offsetof(struct netvsc_ethtool_stats, vlan_error) },
 }, pcpu_stats[] = {
     { "cpu%u_rx_packets",
         offsetof(struct netvsc_ethtool_pcpu_stats, rx_packets) },
     { "cpu%u_rx_bytes",
         offsetof(struct netvsc_ethtool_pcpu_stats, rx_bytes) },
     { "cpu%u_tx_packets",
         offsetof(struct netvsc_ethtool_pcpu_stats, tx_packets) },
     { "cpu%u_tx_bytes",
         offsetof(struct netvsc_ethtool_pcpu_stats, tx_bytes) },
     { "cpu%u_vf_rx_packets",
         offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_packets) },
     { "cpu%u_vf_rx_bytes",
         offsetof(struct netvsc_ethtool_pcpu_stats, vf_rx_bytes) },
     { "cpu%u_vf_tx_packets",
         offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_packets) },
     { "cpu%u_vf_tx_bytes",
         offsetof(struct netvsc_ethtool_pcpu_stats, vf_tx_bytes) },
 }, vf_stats[] = {
     { "vf_rx_packets", offsetof(struct netvsc_vf_pcpu_stats, rx_packets) },
     { "vf_rx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, rx_bytes) },
     { "vf_tx_packets", offsetof(struct netvsc_vf_pcpu_stats, tx_packets) },
     { "vf_tx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, tx_bytes) },
     { "vf_tx_dropped", offsetof(struct netvsc_vf_pcpu_stats, tx_dropped) },
 };
 
 #define NETVSC_GLOBAL_STATS_LEN ARRAY_SIZE(netvsc_stats)
 #define NETVSC_VF_STATS_LEN ARRAY_SIZE(vf_stats)
 
 /* statistics per queue (rx/tx packets/bytes) */
 #define NETVSC_PCPU_STATS_LEN (num_present_cpus() * ARRAY_SIZE(pcpu_stats))
 
 /* 8 statistics per queue (rx/tx packets/bytes, XDP actions) */
 #define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 8)
 
 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
 
     if (!nvdev)
         return -ENODEV;
 
     switch (string_set) {
     case ETH_SS_STATS:
         return NETVSC_GLOBAL_STATS_LEN
             + NETVSC_VF_STATS_LEN
             + NETVSC_QUEUE_STATS_LEN(nvdev)
             + NETVSC_PCPU_STATS_LEN;
     default:
         return -EINVAL;
     }
 }
 
 static void netvsc_get_ethtool_stats(struct net_device *dev,
                      struct ethtool_stats *stats, u64 *data)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
     const void *nds = &ndc->eth_stats;
     const struct netvsc_stats_tx *tx_stats;
     const struct netvsc_stats_rx *rx_stats;
     struct netvsc_vf_pcpu_stats sum;
     struct netvsc_ethtool_pcpu_stats *pcpu_sum;
     unsigned int start;
     u64 packets, bytes;
     u64 xdp_drop;
     u64 xdp_redirect;
     u64 xdp_tx;
     u64 xdp_xmit;
     int i, j, cpu;
 
     if (!nvdev)
         return;
 
     for (i = 0; i < NETVSC_GLOBAL_STATS_LEN; i++)
         data[i] = *(unsigned long *)(nds + netvsc_stats[i].offset);
 
     netvsc_get_vf_stats(dev, &sum);
     for (j = 0; j < NETVSC_VF_STATS_LEN; j++)
         data[i++] = *(u64 *)((void *)&sum + vf_stats[j].offset);
 
     for (j = 0; j < nvdev->num_chn; j++) {
         tx_stats = &nvdev->chan_table[j].tx_stats;
 
         do {
             start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
             packets = tx_stats->packets;
             bytes = tx_stats->bytes;
             xdp_xmit = tx_stats->xdp_xmit;
         } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
         data[i++] = packets;
         data[i++] = bytes;
         data[i++] = xdp_xmit;
 
         rx_stats = &nvdev->chan_table[j].rx_stats;
         do {
             start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
             packets = rx_stats->packets;
             bytes = rx_stats->bytes;
             xdp_drop = rx_stats->xdp_drop;
             xdp_redirect = rx_stats->xdp_redirect;
             xdp_tx = rx_stats->xdp_tx;
         } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
         data[i++] = packets;
         data[i++] = bytes;
         data[i++] = xdp_drop;
         data[i++] = xdp_redirect;
         data[i++] = xdp_tx;
     }
 
     pcpu_sum = kvmalloc_array(num_possible_cpus(),
                   sizeof(struct netvsc_ethtool_pcpu_stats),
                   GFP_KERNEL);
     if (!pcpu_sum)
         return;
 
     netvsc_get_pcpu_stats(dev, pcpu_sum);
     for_each_present_cpu(cpu) {
         struct netvsc_ethtool_pcpu_stats *this_sum = &pcpu_sum[cpu];
 
         for (j = 0; j < ARRAY_SIZE(pcpu_stats); j++)
             data[i++] = *(u64 *)((void *)this_sum
                          + pcpu_stats[j].offset);
     }
     kvfree(pcpu_sum);
 }
 
 static void netvsc_get_strings(struct net_device *dev, u32 stringset, u8 *data)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
     u8 *p = data;
     int i, cpu;
 
     if (!nvdev)
         return;
 
     switch (stringset) {
     case ETH_SS_STATS:
         for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++)
             ethtool_sprintf(&p, netvsc_stats[i].name);
 
         for (i = 0; i < ARRAY_SIZE(vf_stats); i++)
             ethtool_sprintf(&p, vf_stats[i].name);
 
         for (i = 0; i < nvdev->num_chn; i++) {
             ethtool_sprintf(&p, "tx_queue_%u_packets", i);
             ethtool_sprintf(&p, "tx_queue_%u_bytes", i);
             ethtool_sprintf(&p, "tx_queue_%u_xdp_xmit", i);
             ethtool_sprintf(&p, "rx_queue_%u_packets", i);
             ethtool_sprintf(&p, "rx_queue_%u_bytes", i);
             ethtool_sprintf(&p, "rx_queue_%u_xdp_drop", i);
             ethtool_sprintf(&p, "rx_queue_%u_xdp_redirect", i);
             ethtool_sprintf(&p, "rx_queue_%u_xdp_tx", i);
         }
 
         for_each_present_cpu(cpu) {
             for (i = 0; i < ARRAY_SIZE(pcpu_stats); i++)
                 ethtool_sprintf(&p, pcpu_stats[i].name, cpu);
         }
 
         break;
     }
 }
 
 static int
 netvsc_get_rss_hash_opts(struct net_device_context *ndc,
              struct ethtool_rxnfc *info)
 {
     const u32 l4_flag = RXH_L4_B_0_1 | RXH_L4_B_2_3;
 
     info->data = RXH_IP_SRC | RXH_IP_DST;
 
     switch (info->flow_type) {
     case TCP_V4_FLOW:
         if (ndc->l4_hash & HV_TCP4_L4HASH)
             info->data |= l4_flag;
 
         break;
 
     case TCP_V6_FLOW:
         if (ndc->l4_hash & HV_TCP6_L4HASH)
             info->data |= l4_flag;
 
         break;
 
     case UDP_V4_FLOW:
         if (ndc->l4_hash & HV_UDP4_L4HASH)
             info->data |= l4_flag;
 
         break;
 
     case UDP_V6_FLOW:
         if (ndc->l4_hash & HV_UDP6_L4HASH)
             info->data |= l4_flag;
 
         break;
 
     case IPV4_FLOW:
     case IPV6_FLOW:
         break;
     default:
         info->data = 0;
         break;
     }
 
     return 0;
 }
 
 static int
 netvsc_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
          u32 *rules)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
 
     if (!nvdev)
         return -ENODEV;
 
     switch (info->cmd) {
     case ETHTOOL_GRXRINGS:
         info->data = nvdev->num_chn;
         return 0;
 
     case ETHTOOL_GRXFH:
         return netvsc_get_rss_hash_opts(ndc, info);
     }
     return -EOPNOTSUPP;
 }
 
 static int netvsc_set_rss_hash_opts(struct net_device_context *ndc,
                     struct ethtool_rxnfc *info)
 {
     if (info->data == (RXH_IP_SRC | RXH_IP_DST |
                RXH_L4_B_0_1 | RXH_L4_B_2_3)) {
         switch (info->flow_type) {
         case TCP_V4_FLOW:
             ndc->l4_hash |= HV_TCP4_L4HASH;
             break;
 
         case TCP_V6_FLOW:
             ndc->l4_hash |= HV_TCP6_L4HASH;
             break;
 
         case UDP_V4_FLOW:
             ndc->l4_hash |= HV_UDP4_L4HASH;
             break;
 
         case UDP_V6_FLOW:
             ndc->l4_hash |= HV_UDP6_L4HASH;
             break;
 
         default:
             return -EOPNOTSUPP;
         }
 
         return 0;
     }
 
     if (info->data == (RXH_IP_SRC | RXH_IP_DST)) {
         switch (info->flow_type) {
         case TCP_V4_FLOW:
             ndc->l4_hash &= ~HV_TCP4_L4HASH;
             break;
 
         case TCP_V6_FLOW:
             ndc->l4_hash &= ~HV_TCP6_L4HASH;
             break;
 
         case UDP_V4_FLOW:
             ndc->l4_hash &= ~HV_UDP4_L4HASH;
             break;
 
         case UDP_V6_FLOW:
             ndc->l4_hash &= ~HV_UDP6_L4HASH;
             break;
 
         default:
             return -EOPNOTSUPP;
         }
 
         return 0;
     }
 
     return -EOPNOTSUPP;
 }
 
 static int
 netvsc_set_rxnfc(struct net_device *ndev, struct ethtool_rxnfc *info)
 {
     struct net_device_context *ndc = netdev_priv(ndev);
 
     if (info->cmd == ETHTOOL_SRXFH)
         return netvsc_set_rss_hash_opts(ndc, info);
 
     return -EOPNOTSUPP;
 }
 
 static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
 {
     return NETVSC_HASH_KEYLEN;
 }
 
 static u32 netvsc_rss_indir_size(struct net_device *dev)
 {
     return ITAB_NUM;
 }
 
 static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
                u8 *hfunc)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
     struct rndis_device *rndis_dev;
     int i;
 
     if (!ndev)
         return -ENODEV;
 
     if (hfunc)
         *hfunc = ETH_RSS_HASH_TOP;  /* Toeplitz */
 
     rndis_dev = ndev->extension;
     if (indir) {
         for (i = 0; i < ITAB_NUM; i++)
             indir[i] = ndc->rx_table[i];
     }
 
     if (key)
         memcpy(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN);
 
     return 0;
 }
 
 static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
                const u8 *key, const u8 hfunc)
 {
     struct net_device_context *ndc = netdev_priv(dev);
     struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev);
     struct rndis_device *rndis_dev;
     int i;
 
     if (!ndev)
         return -ENODEV;
 
     if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
         return -EOPNOTSUPP;
 
     rndis_dev = ndev->extension;
     if (indir) {
         for (i = 0; i < ITAB_NUM; i++)
             if (indir[i] >= ndev->num_chn)
                 return -EINVAL;
 
         for (i = 0; i < ITAB_NUM; i++)
             ndc->rx_table[i] = indir[i];
     }
 
     if (!key) {
         if (!indir)
             return 0;
 
         key = rndis_dev->rss_key;
     }
 
     return rndis_filter_set_rss_param(rndis_dev, key);
 }
 
 /* Hyper-V RNDIS protocol does not have ring in the HW sense.
  * It does have pre-allocated receive area which is divided into sections.
  */
 static void __netvsc_get_ringparam(struct netvsc_device *nvdev,
                    struct ethtool_ringparam *ring)
 {
     u32 max_buf_size;
 
     ring->rx_pending = nvdev->recv_section_cnt;
     ring->tx_pending = nvdev->send_section_cnt;
 
     if (nvdev->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
         max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
     else
         max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 
     ring->rx_max_pending = max_buf_size / nvdev->recv_section_size;
     ring->tx_max_pending = NETVSC_SEND_BUFFER_SIZE
         / nvdev->send_section_size;
 }
 
 static void netvsc_get_ringparam(struct net_device *ndev,
                  struct ethtool_ringparam *ring,
                  struct kernel_ethtool_ringparam *kernel_ring,
                  struct netlink_ext_ack *extack)
 {
     struct net_device_context *ndevctx = netdev_priv(ndev);
     struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
 
     if (!nvdev)
         return;
 
     __netvsc_get_ringparam(nvdev, ring);
 }
 
 static int netvsc_set_ringparam(struct net_device *ndev,
                 struct ethtool_ringparam *ring,
                 struct kernel_ethtool_ringparam *kernel_ring,
                 struct netlink_ext_ack *extack)
 {
     struct net_device_context *ndevctx = netdev_priv(ndev);
     struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
     struct netvsc_device_info *device_info;
     struct ethtool_ringparam orig;
     u32 new_tx, new_rx;
     int ret = 0;
 
     if (!nvdev || nvdev->destroy)
         return -ENODEV;
 
     memset(&orig, 0, sizeof(orig));
     __netvsc_get_ringparam(nvdev, &orig);
 
     new_tx = clamp_t(u32, ring->tx_pending,
              NETVSC_MIN_TX_SECTIONS, orig.tx_max_pending);
     new_rx = clamp_t(u32, ring->rx_pending,
              NETVSC_MIN_RX_SECTIONS, orig.rx_max_pending);
 
     if (new_tx == orig.tx_pending &&
         new_rx == orig.rx_pending)
         return 0;    /* no change */
 
     device_info = netvsc_devinfo_get(nvdev);
 
     if (!device_info)
         return -ENOMEM;
 
     device_info->send_sections = new_tx;
     device_info->recv_sections = new_rx;
 
     ret = netvsc_detach(ndev, nvdev);
     if (ret)
         goto out;
 
     ret = netvsc_attach(ndev, device_info);
     if (ret) {
         device_info->send_sections = orig.tx_pending;
         device_info->recv_sections = orig.rx_pending;
 
         if (netvsc_attach(ndev, device_info))
             netdev_err(ndev, "restoring ringparam failed");
     }
 
 out:
     netvsc_devinfo_put(device_info);
     return ret;
 }
 
 static netdev_features_t netvsc_fix_features(struct net_device *ndev,
                          netdev_features_t features)
 {
     struct net_device_context *ndevctx = netdev_priv(ndev);
     struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
 
     if (!nvdev || nvdev->destroy)
         return features;
 
     if ((features & NETIF_F_LRO) && netvsc_xdp_get(nvdev)) {
         features ^= NETIF_F_LRO;
         netdev_info(ndev, "Skip LRO - unsupported with XDP\n");
     }
 
     return features;
 }
 
 static int netvsc_set_features(struct net_device *ndev,
                    netdev_features_t features)
 {
     netdev_features_t change = features ^ ndev->features;
     struct net_device_context *ndevctx = netdev_priv(ndev);
     struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
     struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
     struct ndis_offload_params offloads;
     int ret = 0;
 
     if (!nvdev || nvdev->destroy)
         return -ENODEV;
 
     if (!(change & NETIF_F_LRO))
         goto syncvf;
 
     memset(&offloads, 0, sizeof(struct ndis_offload_params));
 
     if (features & NETIF_F_LRO) {
         offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
         offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_ENABLED;
     } else {
         offloads.rsc_ip_v4 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
         offloads.rsc_ip_v6 = NDIS_OFFLOAD_PARAMETERS_RSC_DISABLED;
     }
 
     ret = rndis_filter_set_offload_params(ndev, nvdev, &offloads);
 
     if (ret) {
         features ^= NETIF_F_LRO;
         ndev->features = features;
     }
 
 syncvf:
     if (!vf_netdev)
         return ret;
 
     vf_netdev->wanted_features = features;
     netdev_update_features(vf_netdev);
 
     return ret;
 }
 
 static int netvsc_get_regs_len(struct net_device *netdev)
 {
     return VRSS_SEND_TAB_SIZE * sizeof(u32);
 }
 
 static void netvsc_get_regs(struct net_device *netdev,
                 struct ethtool_regs *regs, void *p)
 {
     struct net_device_context *ndc = netdev_priv(netdev);
     u32 *regs_buff = p;
 
     /* increase the version, if buffer format is changed. */
     regs->version = 1;
 
     memcpy(regs_buff, ndc->tx_table, VRSS_SEND_TAB_SIZE * sizeof(u32));
 }
 
 static u32 netvsc_get_msglevel(struct net_device *ndev)
 {
     struct net_device_context *ndev_ctx = netdev_priv(ndev);
 
     return ndev_ctx->msg_enable;
 }
 
 static void netvsc_set_msglevel(struct net_device *ndev, u32 val)
 {
     struct net_device_context *ndev_ctx = netdev_priv(ndev);
 
     ndev_ctx->msg_enable = val;
 }
 
 static const struct ethtool_ops ethtool_ops = {
     .get_drvinfo    = netvsc_get_drvinfo,
     .get_regs_len   = netvsc_get_regs_len,
     .get_regs   = netvsc_get_regs,
     .get_msglevel   = netvsc_get_msglevel,
     .set_msglevel   = netvsc_set_msglevel,
     .get_link   = ethtool_op_get_link,
     .get_ethtool_stats = netvsc_get_ethtool_stats,
     .get_sset_count = netvsc_get_sset_count,
     .get_strings    = netvsc_get_strings,
     .get_channels   = netvsc_get_channels,
     .set_channels   = netvsc_set_channels,
     .get_ts_info    = ethtool_op_get_ts_info,
     .get_rxnfc  = netvsc_get_rxnfc,
     .set_rxnfc  = netvsc_set_rxnfc,
     .get_rxfh_key_size = netvsc_get_rxfh_key_size,
     .get_rxfh_indir_size = netvsc_rss_indir_size,
     .get_rxfh   = netvsc_get_rxfh,
     .set_rxfh   = netvsc_set_rxfh,
     .get_link_ksettings = netvsc_get_link_ksettings,
     .set_link_ksettings = netvsc_set_link_ksettings,
     .get_ringparam  = netvsc_get_ringparam,
     .set_ringparam  = netvsc_set_ringparam,
 };
 
 static const struct net_device_ops device_ops = {
     .ndo_open =         netvsc_open,
     .ndo_stop =         netvsc_close,
     .ndo_start_xmit =       netvsc_start_xmit,
     .ndo_change_rx_flags =      netvsc_change_rx_flags,
     .ndo_set_rx_mode =      netvsc_set_rx_mode,
     .ndo_fix_features =     netvsc_fix_features,
     .ndo_set_features =     netvsc_set_features,
     .ndo_change_mtu =       netvsc_change_mtu,
     .ndo_validate_addr =        eth_validate_addr,
     .ndo_set_mac_address =      netvsc_set_mac_addr,
     .ndo_select_queue =     netvsc_select_queue,
     .ndo_get_stats64 =      netvsc_get_stats64,
     .ndo_bpf =          netvsc_bpf,
     .ndo_xdp_xmit =         netvsc_ndoxdp_xmit,
 };
 
 /*
  * Handle link status changes. For RNDIS_STATUS_NETWORK_CHANGE emulate link
  * down/up sequence. In case of RNDIS_STATUS_MEDIA_CONNECT when carrier is
  * present send GARP packet to network peers with netif_notify_peers().
  */
 static void netvsc_link_change(struct work_struct *w)
 {
     struct net_device_context *ndev_ctx =
         container_of(w, struct net_device_context, dwork.work);
     struct hv_device *device_obj = ndev_ctx->device_ctx;
     struct net_device *net = hv_get_drvdata(device_obj);
     unsigned long flags, next_reconfig, delay;
     struct netvsc_reconfig *event = NULL;
     struct netvsc_device *net_device;
     struct rndis_device *rdev;
     bool reschedule = false;
 
     /* if changes are happening, comeback later */
     if (!rtnl_trylock()) {
         schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
         return;
     }
 
     net_device = rtnl_dereference(ndev_ctx->nvdev);
     if (!net_device)
         goto out_unlock;
 
     rdev = net_device->extension;
 
     next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
     if (time_is_after_jiffies(next_reconfig)) {
         /* link_watch only sends one notification with current state
          * per second, avoid doing reconfig more frequently. Handle
          * wrap around.
          */
         delay = next_reconfig - jiffies;
         delay = delay < LINKCHANGE_INT ? delay : LINKCHANGE_INT;
         schedule_delayed_work(&ndev_ctx->dwork, delay);
         goto out_unlock;
     }
     ndev_ctx->last_reconfig = jiffies;
 
     spin_lock_irqsave(&ndev_ctx->lock, flags);
     if (!list_empty(&ndev_ctx->reconfig_events)) {
         event = list_first_entry(&ndev_ctx->reconfig_events,
                      struct netvsc_reconfig, list);
         list_del(&event->list);
         reschedule = !list_empty(&ndev_ctx->reconfig_events);
     }
     spin_unlock_irqrestore(&ndev_ctx->lock, flags);
 
     if (!event)
         goto out_unlock;
 
     switch (event->event) {
         /* Only the following events are possible due to the check in
          * netvsc_linkstatus_callback()
          */
     case RNDIS_STATUS_MEDIA_CONNECT:
         if (rdev->link_state) {
             rdev->link_state = false;
             netif_carrier_on(net);
             netvsc_tx_enable(net_device, net);
         } else {
             __netdev_notify_peers(net);
         }
         kfree(event);
         break;
     case RNDIS_STATUS_MEDIA_DISCONNECT:
         if (!rdev->link_state) {
             rdev->link_state = true;
             netif_carrier_off(net);
             netvsc_tx_disable(net_device, net);
         }
         kfree(event);
         break;
     case RNDIS_STATUS_NETWORK_CHANGE:
         /* Only makes sense if carrier is present */
         if (!rdev->link_state) {
             rdev->link_state = true;
             netif_carrier_off(net);
             netvsc_tx_disable(net_device, net);
             event->event = RNDIS_STATUS_MEDIA_CONNECT;
             spin_lock_irqsave(&ndev_ctx->lock, flags);
             list_add(&event->list, &ndev_ctx->reconfig_events);
             spin_unlock_irqrestore(&ndev_ctx->lock, flags);
             reschedule = true;
         }
         break;
     }
 
     rtnl_unlock();
 
     /* link_watch only sends one notification with current state per
      * second, handle next reconfig event in 2 seconds.
      */
     if (reschedule)
         schedule_delayed_work(&ndev_ctx->dwork, LINKCHANGE_INT);
 
     return;
 
 out_unlock:
     rtnl_unlock();
 }
 
 static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
 {
     struct net_device_context *net_device_ctx;
     struct net_device *dev;
 
     dev = netdev_master_upper_dev_get(vf_netdev);
     if (!dev || dev->netdev_ops != &device_ops)
         return NULL;    /* not a netvsc device */
 
     net_device_ctx = netdev_priv(dev);
     if (!rtnl_dereference(net_device_ctx->nvdev))
         return NULL;    /* device is removed */
 
     return dev;
 }
 
 /* Called when VF is injecting data into network stack.
  * Change the associated network device from VF to netvsc.
  * note: already called with rcu_read_lock
  */
 static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
 {
     struct sk_buff *skb = *pskb;
     struct net_device *ndev = rcu_dereference(skb->dev->rx_handler_data);
     struct net_device_context *ndev_ctx = netdev_priv(ndev);
     struct netvsc_vf_pcpu_stats *pcpu_stats
          = this_cpu_ptr(ndev_ctx->vf_stats);
 
     skb = skb_share_check(skb, GFP_ATOMIC);
     if (unlikely(!skb))
         return RX_HANDLER_CONSUMED;
 
     *pskb = skb;
 
     skb->dev = ndev;
 
     u64_stats_update_begin(&pcpu_stats->syncp);
     pcpu_stats->rx_packets++;
     pcpu_stats->rx_bytes += skb->len;
     u64_stats_update_end(&pcpu_stats->syncp);
 
     return RX_HANDLER_ANOTHER;
 }
 
 static int netvsc_vf_join(struct net_device *vf_netdev,
               struct net_device *ndev)
 {
     struct net_device_context *ndev_ctx = netdev_priv(ndev);
     int ret;
 
     ret = netdev_rx_handler_register(vf_netdev,
                      netvsc_vf_handle_frame, ndev);
     if (ret != 0) {
         netdev_err(vf_netdev,
                "can not register netvsc VF receive handler (err = %d)\n",
                ret);
         goto rx_handler_failed;
     }
 
     ret = netdev_master_upper_dev_link(vf_netdev, ndev,
                        NULL, NULL, NULL);
     if (ret != 0) {
         netdev_err(vf_netdev,
                "can not set master device %s (err = %d)\n",
                ndev->name, ret);
         goto upper_link_failed;
     }
 
     /* set slave flag before open to prevent IPv6 addrconf */
     vf_netdev->flags |= IFF_SLAVE;
 
     schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
 
     call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
 
     netdev_info(vf_netdev, "joined to %s\n", ndev->name);
     return 0;
 
 upper_link_failed:
     netdev_rx_handler_unregister(vf_netdev);
 rx_handler_failed:
     return ret;
 }
 
 static void __netvsc_vf_setup(struct net_device *ndev,
                   struct net_device *vf_netdev)
 {
     int ret;
 
     /* Align MTU of VF with master */
     ret = dev_set_mtu(vf_netdev, ndev->mtu);
     if (ret)
         netdev_warn(vf_netdev,
                 "unable to change mtu to %u\n", ndev->mtu);
 
     /* set multicast etc flags on VF */
     dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE, NULL);
 
     /* sync address list from ndev to VF */
     netif_addr_lock_bh(ndev);
     dev_uc_sync(vf_netdev, ndev);
     dev_mc_sync(vf_netdev, ndev);
     netif_addr_unlock_bh(ndev);
 
     if (netif_running(ndev)) {
         ret = dev_open(vf_netdev, NULL);
         if (ret)
             netdev_warn(vf_netdev,
                     "unable to open: %d\n", ret);
     }
 }
 
 /* Setup VF as slave of the synthetic device.
  * Runs in workqueue to avoid recursion in netlink callbacks.
  */
 static void netvsc_vf_setup(struct work_struct *w)
 {
     struct net_device_context *ndev_ctx
         = container_of(w, struct net_device_context, vf_takeover.work);
     struct net_device *ndev = hv_get_drvdata(ndev_ctx->device_ctx);
     struct net_device *vf_netdev;
 
     if (!rtnl_trylock()) {
         schedule_delayed_work(&ndev_ctx->vf_takeover, 0);
         return;
     }
 
     vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
     if (vf_netdev)
         __netvsc_vf_setup(ndev, vf_netdev);
 
     rtnl_unlock();
 }
 
 /* Find netvsc by VF serial number.
  * The PCI hyperv controller records the serial number as the slot kobj name.
  */
 static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
 {
     struct device *parent = vf_netdev->dev.parent;
     struct net_device_context *ndev_ctx;
     struct net_device *ndev;
     struct pci_dev *pdev;
     u32 serial;
 
     if (!parent || !dev_is_pci(parent))
         return NULL; /* not a PCI device */
 
     pdev = to_pci_dev(parent);
     if (!pdev->slot) {
         netdev_notice(vf_netdev, "no PCI slot information\n");
         return NULL;
     }
 
     if (kstrtou32(pci_slot_name(pdev->slot), 10, &serial)) {
         netdev_notice(vf_netdev, "Invalid vf serial:%s\n",
                   pci_slot_name(pdev->slot));
         return NULL;
     }
 
     list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
         if (!ndev_ctx->vf_alloc)
             continue;
 
         if (ndev_ctx->vf_serial != serial)
             continue;
 
         ndev = hv_get_drvdata(ndev_ctx->device_ctx);
         if (ndev->addr_len != vf_netdev->addr_len ||
             memcmp(ndev->perm_addr, vf_netdev->perm_addr,
                ndev->addr_len) != 0)
             continue;
 
         return ndev;
 
     }
 
     netdev_notice(vf_netdev,
               "no netdev found for vf serial:%u\n", serial);
     return NULL;
 }
 
 static int netvsc_register_vf(struct net_device *vf_netdev)
 {
     struct net_device_context *net_device_ctx;
     struct netvsc_device *netvsc_dev;
     struct bpf_prog *prog;
     struct net_device *ndev;
     int ret;
 
     if (vf_netdev->addr_len != ETH_ALEN)
         return NOTIFY_DONE;
 
     ndev = get_netvsc_byslot(vf_netdev);
     if (!ndev)
         return NOTIFY_DONE;
 
     net_device_ctx = netdev_priv(ndev);
     netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
     if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
         return NOTIFY_DONE;
 
     /* if synthetic interface is a different namespace,
      * then move the VF to that namespace; join will be
      * done again in that context.
      */
     if (!net_eq(dev_net(ndev), dev_net(vf_netdev))) {
         ret = dev_change_net_namespace(vf_netdev,
                            dev_net(ndev), "eth%d");
         if (ret)
             netdev_err(vf_netdev,
                    "could not move to same namespace as %s: %d\n",
                    ndev->name, ret);
         else
             netdev_info(vf_netdev,
                     "VF moved to namespace with: %s\n",
                     ndev->name);
         return NOTIFY_DONE;
     }
 
     netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
 
     if (netvsc_vf_join(vf_netdev, ndev) != 0)
         return NOTIFY_DONE;
 
     dev_hold(vf_netdev);
     rcu_assign_pointer(net_device_ctx->vf_netdev, vf_netdev);
 
     if (ndev->needed_headroom < vf_netdev->needed_headroom)
         ndev->needed_headroom = vf_netdev->needed_headroom;
 
     vf_netdev->wanted_features = ndev->features;
     netdev_update_features(vf_netdev);
 
     prog = netvsc_xdp_get(netvsc_dev);
     netvsc_vf_setxdp(vf_netdev, prog);
 
     return NOTIFY_OK;
 }
 
 /* Change the data path when VF UP/DOWN/CHANGE are detected.
  *
  * Typically a UP or DOWN event is followed by a CHANGE event, so
  * net_device_ctx->data_path_is_vf is used to cache the current data path
  * to avoid the duplicate call of netvsc_switch_datapath() and the duplicate
  * message.
  *
  * During hibernation, if a VF NIC driver (e.g. mlx5) preserves the network
  * interface, there is only the CHANGE event and no UP or DOWN event.
  */
 static int netvsc_vf_changed(struct net_device *vf_netdev, unsigned long event)
 {
     struct net_device_context *net_device_ctx;
     struct netvsc_device *netvsc_dev;
     struct net_device *ndev;
     bool vf_is_up = false;
     int ret;
 
     if (event != NETDEV_GOING_DOWN)
         vf_is_up = netif_running(vf_netdev);
 
     ndev = get_netvsc_byref(vf_netdev);
     if (!ndev)
         return NOTIFY_DONE;
 
     net_device_ctx = netdev_priv(ndev);
     netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
     if (!netvsc_dev)
         return NOTIFY_DONE;
 
     if (net_device_ctx->data_path_is_vf == vf_is_up)
         return NOTIFY_OK;
 
     ret = netvsc_switch_datapath(ndev, vf_is_up);
 
     if (ret) {
         netdev_err(ndev,
                "Data path failed to switch %s VF: %s, err: %d\n",
                vf_is_up ? "to" : "from", vf_netdev->name, ret);
         return NOTIFY_DONE;
     } else {
         netdev_info(ndev, "Data path switched %s VF: %s\n",
                 vf_is_up ? "to" : "from", vf_netdev->name);
     }
 
     return NOTIFY_OK;
 }
 
 static int netvsc_unregister_vf(struct net_device *vf_netdev)
 {
     struct net_device *ndev;
     struct net_device_context *net_device_ctx;
 
     ndev = get_netvsc_byref(vf_netdev);
     if (!ndev)
         return NOTIFY_DONE;
 
     net_device_ctx = netdev_priv(ndev);
     cancel_delayed_work_sync(&net_device_ctx->vf_takeover);
 
     netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
 
     netvsc_vf_setxdp(vf_netdev, NULL);
 
     netdev_rx_handler_unregister(vf_netdev);
     netdev_upper_dev_unlink(vf_netdev, ndev);
     RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
     dev_put(vf_netdev);
 
     ndev->needed_headroom = RNDIS_AND_PPI_SIZE;
 
     return NOTIFY_OK;
 }
 
 static int netvsc_probe(struct hv_device *dev,
             const struct hv_vmbus_device_id *dev_id)
 {
     struct net_device *net = NULL;
     struct net_device_context *net_device_ctx;
     struct netvsc_device_info *device_info = NULL;
     struct netvsc_device *nvdev;
     int ret = -ENOMEM;
 
     net = alloc_etherdev_mq(sizeof(struct net_device_context),
                 VRSS_CHANNEL_MAX);
     if (!net)
         goto no_net;
 
     netif_carrier_off(net);
 
     netvsc_init_settings(net);
 
     net_device_ctx = netdev_priv(net);
     net_device_ctx->device_ctx = dev;
     net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
     if (netif_msg_probe(net_device_ctx))
         netdev_dbg(net, "netvsc msg_enable: %d\n",
                net_device_ctx->msg_enable);
 
     hv_set_drvdata(dev, net);
 
     INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
 
     spin_lock_init(&net_device_ctx->lock);
     INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
     INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
 
     net_device_ctx->vf_stats
         = netdev_alloc_pcpu_stats(struct netvsc_vf_pcpu_stats);
     if (!net_device_ctx->vf_stats)
         goto no_stats;
 
     net->netdev_ops = &device_ops;
     net->ethtool_ops = &ethtool_ops;
     SET_NETDEV_DEV(net, &dev->device);
     dma_set_min_align_mask(&dev->device, HV_HYP_PAGE_SIZE - 1);
 
     /* We always need headroom for rndis header */
     net->needed_headroom = RNDIS_AND_PPI_SIZE;
 
     /* Initialize the number of queues to be 1, we may change it if more
      * channels are offered later.
      */
     netif_set_real_num_tx_queues(net, 1);
     netif_set_real_num_rx_queues(net, 1);
 
     /* Notify the netvsc driver of the new device */
     device_info = netvsc_devinfo_get(NULL);
 
     if (!device_info) {
         ret = -ENOMEM;
         goto devinfo_failed;
     }
 
     nvdev = rndis_filter_device_add(dev, device_info);
     if (IS_ERR(nvdev)) {
         ret = PTR_ERR(nvdev);
         netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
         goto rndis_failed;
     }
 
     eth_hw_addr_set(net, device_info->mac_adr);
 
     /* We must get rtnl lock before scheduling nvdev->subchan_work,
      * otherwise netvsc_subchan_work() can get rtnl lock first and wait
      * all subchannels to show up, but that may not happen because
      * netvsc_probe() can't get rtnl lock and as a result vmbus_onoffer()
      * -> ... -> device_add() -> ... -> __device_attach() can't get
      * the device lock, so all the subchannels can't be processed --
      * finally netvsc_subchan_work() hangs forever.
      */
     rtnl_lock();
 
     if (nvdev->num_chn > 1)
         schedule_work(&nvdev->subchan_work);
 
     /* hw_features computed in rndis_netdev_set_hwcaps() */
     net->features = net->hw_features |
         NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX |
         NETIF_F_HW_VLAN_CTAG_RX;
     net->vlan_features = net->features;
 
     netdev_lockdep_set_classes(net);
 
     /* MTU range: 68 - 1500 or 65521 */
     net->min_mtu = NETVSC_MTU_MIN;
     if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
         net->max_mtu = NETVSC_MTU - ETH_HLEN;
     else
         net->max_mtu = ETH_DATA_LEN;
 
     nvdev->tx_disable = false;
 
     ret = register_netdevice(net);
     if (ret != 0) {
         pr_err("Unable to register netdev.\n");
         goto register_failed;
     }
 
     list_add(&net_device_ctx->list, &netvsc_dev_list);
     rtnl_unlock();
 
     netvsc_devinfo_put(device_info);
     return 0;
 
 register_failed:
     rtnl_unlock();
     rndis_filter_device_remove(dev, nvdev);
 rndis_failed:
     netvsc_devinfo_put(device_info);
 devinfo_failed:
     free_percpu(net_device_ctx->vf_stats);
 no_stats:
     hv_set_drvdata(dev, NULL);
     free_netdev(net);
 no_net:
     return ret;
 }
 
 static int netvsc_remove(struct hv_device *dev)
 {
     struct net_device_context *ndev_ctx;
     struct net_device *vf_netdev, *net;
     struct netvsc_device *nvdev;
 
     net = hv_get_drvdata(dev);
     if (net == NULL) {
         dev_err(&dev->device, "No net device to remove\n");
         return 0;
     }
 
     ndev_ctx = netdev_priv(net);
 
     cancel_delayed_work_sync(&ndev_ctx->dwork);
 
     rtnl_lock();
     nvdev = rtnl_dereference(ndev_ctx->nvdev);
     if (nvdev) {
         cancel_work_sync(&nvdev->subchan_work);
         netvsc_xdp_set(net, NULL, NULL, nvdev);
     }
 
     /*
      * Call to the vsc driver to let it know that the device is being
      * removed. Also blocks mtu and channel changes.
      */
     vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
     if (vf_netdev)
         netvsc_unregister_vf(vf_netdev);
 
     if (nvdev)
         rndis_filter_device_remove(dev, nvdev);
 
     unregister_netdevice(net);
     list_del(&ndev_ctx->list);
 
     rtnl_unlock();
 
     hv_set_drvdata(dev, NULL);
 
     free_percpu(ndev_ctx->vf_stats);
     free_netdev(net);
     return 0;
 }
 
 static int netvsc_suspend(struct hv_device *dev)
 {
     struct net_device_context *ndev_ctx;
     struct netvsc_device *nvdev;
     struct net_device *net;
     int ret;
 
     net = hv_get_drvdata(dev);
 
     ndev_ctx = netdev_priv(net);
     cancel_delayed_work_sync(&ndev_ctx->dwork);
 
     rtnl_lock();
 
     nvdev = rtnl_dereference(ndev_ctx->nvdev);
     if (nvdev == NULL) {
         ret = -ENODEV;
         goto out;
     }
 
     /* Save the current config info */
     ndev_ctx->saved_netvsc_dev_info = netvsc_devinfo_get(nvdev);
     if (!ndev_ctx->saved_netvsc_dev_info) {
         ret = -ENOMEM;
         goto out;
     }
     ret = netvsc_detach(net, nvdev);
 out:
     rtnl_unlock();
 
     return ret;
 }
 
 static int netvsc_resume(struct hv_device *dev)
 {
     struct net_device *net = hv_get_drvdata(dev);
     struct net_device_context *net_device_ctx;
     struct netvsc_device_info *device_info;
     int ret;
 
     rtnl_lock();
 
     net_device_ctx = netdev_priv(net);
 
     /* Reset the data path to the netvsc NIC before re-opening the vmbus
      * channel. Later netvsc_netdev_event() will switch the data path to
      * the VF upon the UP or CHANGE event.
      */
     net_device_ctx->data_path_is_vf = false;
     device_info = net_device_ctx->saved_netvsc_dev_info;
 
     ret = netvsc_attach(net, device_info);
 
     netvsc_devinfo_put(device_info);
     net_device_ctx->saved_netvsc_dev_info = NULL;
 
     rtnl_unlock();
 
     return ret;
 }
 static const struct hv_vmbus_device_id id_table[] = {
     /* Network guid */
     { HV_NIC_GUID, },
     { },
 };
 
 MODULE_DEVICE_TABLE(vmbus, id_table);
 
 /* The one and only one */
 static struct  hv_driver netvsc_drv = {
     .name = KBUILD_MODNAME,
     .id_table = id_table,
     .probe = netvsc_probe,
     .remove = netvsc_remove,
     .suspend = netvsc_suspend,
     .resume = netvsc_resume,
     .driver = {
         .probe_type = PROBE_FORCE_SYNCHRONOUS,
     },
 };
 
 /*
  * On Hyper-V, every VF interface is matched with a corresponding
  * synthetic interface. The synthetic interface is presented first
  * to the guest. When the corresponding VF instance is registered,
  * we will take care of switching the data path.
  */
 static int netvsc_netdev_event(struct notifier_block *this,
                    unsigned long event, void *ptr)
 {
     struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
 
     /* Skip our own events */
     if (event_dev->netdev_ops == &device_ops)
         return NOTIFY_DONE;
 
     /* Avoid non-Ethernet type devices */
     if (event_dev->type != ARPHRD_ETHER)
         return NOTIFY_DONE;
 
     /* Avoid Vlan dev with same MAC registering as VF */
     if (is_vlan_dev(event_dev))
         return NOTIFY_DONE;
 
     /* Avoid Bonding master dev with same MAC registering as VF */
     if (netif_is_bond_master(event_dev))
         return NOTIFY_DONE;
 
     switch (event) {
     case NETDEV_REGISTER:
         return netvsc_register_vf(event_dev);
     case NETDEV_UNREGISTER:
         return netvsc_unregister_vf(event_dev);
     case NETDEV_UP:
     case NETDEV_DOWN:
     case NETDEV_CHANGE:
     case NETDEV_GOING_DOWN:
         return netvsc_vf_changed(event_dev, event);
     default:
         return NOTIFY_DONE;
     }
 }
 
 static struct notifier_block netvsc_netdev_notifier = {
     .notifier_call = netvsc_netdev_event,
 };
 
 static void __exit netvsc_drv_exit(void)
 {
     unregister_netdevice_notifier(&netvsc_netdev_notifier);
     vmbus_driver_unregister(&netvsc_drv);
 }
 
 static int __init netvsc_drv_init(void)
 {
     int ret;
 
     if (ring_size < RING_SIZE_MIN) {
         ring_size = RING_SIZE_MIN;
         pr_info("Increased ring_size to %u (min allowed)\n",
             ring_size);
     }
     netvsc_ring_bytes = ring_size * PAGE_SIZE;
 
     ret = vmbus_driver_register(&netvsc_drv);
     if (ret)
         return ret;
 
     register_netdevice_notifier(&netvsc_netdev_notifier);
     return 0;
 }
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
 
 module_init(netvsc_drv_init);
 module_exit(netvsc_drv_exit);