hv_netvsc: Add XDP support

This patch adds support of XDP in native mode for hv_netvsc driver, and
transparently sets the XDP program on the associated VF NIC as well.

Setting / unsetting XDP program on synthetic NIC (netvsc) propagates to
VF NIC automatically. Setting / unsetting XDP program on VF NIC directly
is not recommended, also not propagated to synthetic NIC, and may be
overwritten by setting of synthetic NIC.

The Azure/Hyper-V synthetic NIC receive buffer doesn't provide headroom
for XDP. We thought about re-use the RNDIS header space, but it's too
small. So we decided to copy the packets to a page buffer for XDP. And,
most of our VMs on Azure have Accelerated Network (SRIOV) enabled, so
most of the packets run on VF NIC. The synthetic NIC is considered as a
fallback data-path. So the data copy on netvsc won't impact performance
significantly.

XDP program cannot run with LRO (RSC) enabled, so you need to disable LRO
before running XDP:
ethtool -K eth0 lro off

XDP actions not yet supported:
XDP_REDIRECT

Signed-off-by: Haiyang Zhang <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/hyperv/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_HYPERV_NET) += hv_netvsc.o
 
-hv_netvsc-y := netvsc_drv.o netvsc.o rndis_filter.o netvsc_trace.o
+hv_netvsc-y := netvsc_drv.o netvsc.o rndis_filter.o netvsc_trace.o netvsc_bpf.o

drivers/net/hyperv/hyperv_net.h

···
 	u32  send_section_size;
 	u32  recv_section_size;
 
+	struct bpf_prog *bprog;
+
 	u8 rss_key[NETVSC_HASH_KEYLEN];
 };
 
···
 		struct hv_netvsc_packet *packet,
 		struct rndis_message *rndis_msg,
 		struct hv_page_buffer *page_buffer,
-		struct sk_buff *skb);
+		struct sk_buff *skb,
+		bool xdp_tx);
 void netvsc_linkstatus_callback(struct net_device *net,
 				struct rndis_message *resp);
 int netvsc_recv_callback(struct net_device *net,
···
 			 struct netvsc_channel *nvchan);
 void netvsc_channel_cb(void *context);
 int netvsc_poll(struct napi_struct *napi, int budget);
+
+u32 netvsc_run_xdp(struct net_device *ndev, struct netvsc_channel *nvchan,
+		   struct xdp_buff *xdp);
+unsigned int netvsc_xdp_fraglen(unsigned int len);
+struct bpf_prog *netvsc_xdp_get(struct netvsc_device *nvdev);
+int netvsc_xdp_set(struct net_device *dev, struct bpf_prog *prog,
+		   struct netlink_ext_ack *extack,
+		   struct netvsc_device *nvdev);
+int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog);
+int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf);
 
 int rndis_set_subchannel(struct net_device *ndev,
 			 struct netvsc_device *nvdev,
···
 #define RNDIS_MAX_PKT_DEFAULT 8
 #define RNDIS_PKT_ALIGN_DEFAULT 8
 
+#define NETVSC_XDP_HDRM 256
+
 struct multi_send_data {
 	struct sk_buff *skb; /* skb containing the pkt */
 	struct hv_netvsc_packet *pkt; /* netvsc pkt pending */
···
 	u64 bytes;
 	u64 broadcast;
 	u64 multicast;
+	u64 xdp_drop;
 	struct u64_stats_sync syncp;
 };
 
···
 	struct multi_recv_comp mrc;
 	atomic_t queue_sends;
 	struct nvsc_rsc rsc;
+
+	struct bpf_prog __rcu *bpf_prog;
+	struct xdp_rxq_info xdp_rxq;
 
 	struct netvsc_stats tx_stats;
 	struct netvsc_stats rx_stats;

drivers/net/hyperv/netvsc.c

···
 	vfree(nvdev->send_buf);
 	kfree(nvdev->send_section_map);
 
-	for (i = 0; i < VRSS_CHANNEL_MAX; i++)
+	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
+		xdp_rxq_info_unreg(&nvdev->chan_table[i].xdp_rxq);
 		vfree(nvdev->chan_table[i].mrc.slots);
+	}
 
 	kfree(nvdev);
 }
···
 		struct hv_netvsc_packet *packet,
 		struct rndis_message *rndis_msg,
 		struct hv_page_buffer *pb,
-		struct sk_buff *skb)
+		struct sk_buff *skb,
+		bool xdp_tx)
 {
 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
 	struct netvsc_device *net_device
···
 	packet->send_buf_index = NETVSC_INVALID_INDEX;
 	packet->cp_partial = false;
 
-	/* Send control message directly without accessing msd (Multi-Send
-	 * Data) field which may be changed during data packet processing.
+	/* Send a control message or XDP packet directly without accessing
+	 * msd (Multi-Send Data) field which may be changed during data packet
+	 * processing.
 	 */
-	if (!skb)
+	if (!skb || xdp_tx)
 		return netvsc_send_pkt(device, packet, net_device, pb, skb);
 
 	/* batch packets in send buffer if possible */
···
 		nvchan->net_device = net_device;
 		u64_stats_init(&nvchan->tx_stats.syncp);
 		u64_stats_init(&nvchan->rx_stats.syncp);
+
+		ret = xdp_rxq_info_reg(&nvchan->xdp_rxq, ndev, i);
+
+		if (ret) {
+			netdev_err(ndev, "xdp_rxq_info_reg fail: %d\n", ret);
+			goto cleanup2;
+		}
+
+		ret = xdp_rxq_info_reg_mem_model(&nvchan->xdp_rxq,
+						 MEM_TYPE_PAGE_SHARED, NULL);
+
+		if (ret) {
+			netdev_err(ndev, "xdp reg_mem_model fail: %d\n", ret);
+			goto cleanup2;
+		}
 	}
 
 	/* Enable NAPI handler before init callbacks */
···
 
 cleanup:
 	netif_napi_del(&net_device->chan_table[0].napi);
+
+cleanup2:
 	free_netvsc_device(&net_device->rcu);
 
 	return ERR_PTR(ret);

drivers/net/hyperv/netvsc_bpf.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019, Microsoft Corporation.
+ *
+ * Author:
+ *   Haiyang Zhang <[e-mail]>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
+#include <linux/kernel.h>
+#include <net/xdp.h>
+
+#include <linux/mutex.h>
+#include <linux/rtnetlink.h>
+
+#include "hyperv_net.h"
+
+u32 netvsc_run_xdp(struct net_device *ndev, struct netvsc_channel *nvchan,
+		   struct xdp_buff *xdp)
+{
+	void *data = nvchan->rsc.data[0];
+	u32 len = nvchan->rsc.len[0];
+	struct page *page = NULL;
+	struct bpf_prog *prog;
+	u32 act = XDP_PASS;
+
+	xdp->data_hard_start = NULL;
+
+	rcu_read_lock();
+	prog = rcu_dereference(nvchan->bpf_prog);
+
+	if (!prog)
+		goto out;
+
+	/* allocate page buffer for data */
+	page = alloc_page(GFP_ATOMIC);
+	if (!page) {
+		act = XDP_DROP;
+		goto out;
+	}
+
+	xdp->data_hard_start = page_address(page);
+	xdp->data = xdp->data_hard_start + NETVSC_XDP_HDRM;
+	xdp_set_data_meta_invalid(xdp);
+	xdp->data_end = xdp->data + len;
+	xdp->rxq = &nvchan->xdp_rxq;
+	xdp->handle = 0;
+
+	memcpy(xdp->data, data, len);
+
+	act = bpf_prog_run_xdp(prog, xdp);
+
+	switch (act) {
+	case XDP_PASS:
+	case XDP_TX:
+	case XDP_DROP:
+		break;
+
+	case XDP_ABORTED:
+		trace_xdp_exception(ndev, prog, act);
+		break;
+
+	default:
+		bpf_warn_invalid_xdp_action(act);
+	}
+
+out:
+	rcu_read_unlock();
+
+	if (page && act != XDP_PASS && act != XDP_TX) {
+		__free_page(page);
+		xdp->data_hard_start = NULL;
+	}
+
+	return act;
+}
+
+unsigned int netvsc_xdp_fraglen(unsigned int len)
+{
+	return SKB_DATA_ALIGN(len) +
+	       SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+}
+
+struct bpf_prog *netvsc_xdp_get(struct netvsc_device *nvdev)
+{
+	return rtnl_dereference(nvdev->chan_table[0].bpf_prog);
+}
+
+int netvsc_xdp_set(struct net_device *dev, struct bpf_prog *prog,
+		   struct netlink_ext_ack *extack,
+		   struct netvsc_device *nvdev)
+{
+	struct bpf_prog *old_prog;
+	int buf_max, i;
+
+	old_prog = netvsc_xdp_get(nvdev);
+
+	if (!old_prog && !prog)
+		return 0;
+
+	buf_max = NETVSC_XDP_HDRM + netvsc_xdp_fraglen(dev->mtu + ETH_HLEN);
+	if (prog && buf_max > PAGE_SIZE) {
+		netdev_err(dev, "XDP: mtu:%u too large, buf_max:%u\n",
+			   dev->mtu, buf_max);
+		NL_SET_ERR_MSG_MOD(extack, "XDP: mtu too large");
+
+		return -EOPNOTSUPP;
+	}
+
+	if (prog && (dev->features & NETIF_F_LRO)) {
+		netdev_err(dev, "XDP: not support LRO\n");
+		NL_SET_ERR_MSG_MOD(extack, "XDP: not support LRO");
+
+		return -EOPNOTSUPP;
+	}
+
+	if (prog)
+		bpf_prog_add(prog, nvdev->num_chn);
+
+	for (i = 0; i < nvdev->num_chn; i++)
+		rcu_assign_pointer(nvdev->chan_table[i].bpf_prog, prog);
+
+	if (old_prog)
+		for (i = 0; i < nvdev->num_chn; i++)
+			bpf_prog_put(old_prog);
+
+	return 0;
+}
+
+int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog)
+{
+	struct netdev_bpf xdp;
+	bpf_op_t ndo_bpf;
+
+	ASSERT_RTNL();
+
+	if (!vf_netdev)
+		return 0;
+
+	ndo_bpf = vf_netdev->netdev_ops->ndo_bpf;
+	if (!ndo_bpf)
+		return 0;
+
+	memset(&xdp, 0, sizeof(xdp));
+
+	xdp.command = XDP_SETUP_PROG;
+	xdp.prog = prog;
+
+	return ndo_bpf(vf_netdev, &xdp);
+}
+
+static u32 netvsc_xdp_query(struct netvsc_device *nvdev)
+{
+	struct bpf_prog *prog = netvsc_xdp_get(nvdev);
+
+	if (prog)
+		return prog->aux->id;
+
+	return 0;
+}
+
+int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
+{
+	struct net_device_context *ndevctx = netdev_priv(dev);
+	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
+	struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
+	struct netlink_ext_ack *extack = bpf->extack;
+	int ret;
+
+	if (!nvdev || nvdev->destroy) {
+		if (bpf->command == XDP_QUERY_PROG) {
+			bpf->prog_id = 0;
+			return 0; /* Query must always succeed */
+		} else {
+			return -ENODEV;
+		}
+	}
+
+	switch (bpf->command) {
+	case XDP_SETUP_PROG:
+		ret = netvsc_xdp_set(dev, bpf->prog, extack, nvdev);
+
+		if (ret)
+			return ret;
+
+		ret = netvsc_vf_setxdp(vf_netdev, bpf->prog);
+
+		if (ret) {
+			netdev_err(dev, "vf_setxdp failed:%d\n", ret);
+			NL_SET_ERR_MSG_MOD(extack, "vf_setxdp failed");
+
+			netvsc_xdp_set(dev, NULL, extack, nvdev);
+		}
+
+		return ret;
+
+	case XDP_QUERY_PROG:
+		bpf->prog_id = netvsc_xdp_query(nvdev);
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}

drivers/net/hyperv/netvsc_drv.c

···
 #include <linux/slab.h>
 #include <linux/rtnetlink.h>
 #include <linux/netpoll.h>
+#include <linux/bpf.h>
 
 #include <net/arp.h>
 #include <net/route.h>
···
 	return rc;
 }
 
-static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
+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;
···
 	/* timestamp packet in software */
 	skb_tx_timestamp(skb);
 
-	ret = netvsc_send(net, packet, rndis_msg, pb, skb);
+	ret = netvsc_send(net, packet, rndis_msg, pb, skb, xdp_tx);
 	if (likely(ret == 0))
 		return NETDEV_TX_OK;
 
···
 no_memory:
 	++net_device_ctx->eth_stats.tx_no_memory;
 	goto drop;
+}
+
+static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	return netvsc_xmit(skb, ndev, false);
 }
 
 /*
···
 	schedule_delayed_work(&ndev_ctx->dwork, 0);
 }
 
+static 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;
···
 }
 
 static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net,
-					     struct netvsc_channel *nvchan)
+					     struct netvsc_channel *nvchan,
+					     struct xdp_buff *xdp)
 {
 	struct napi_struct *napi = &nvchan->napi;
 	const struct ndis_pkt_8021q_info *vlan = nvchan->rsc.vlan;
···
 						nvchan->rsc.csum_info;
 	const u32 *hash_info = nvchan->rsc.hash_info;
 	struct sk_buff *skb;
+	void *xbuf = xdp->data_hard_start;
 	int i;
 
-	skb = napi_alloc_skb(napi, nvchan->rsc.pktlen);
-	if (!skb)
-		return skb;
+	if (xbuf) {
+		unsigned int hdroom = xdp->data - xdp->data_hard_start;
+		unsigned int xlen = xdp->data_end - xdp->data;
+		unsigned int frag_size = netvsc_xdp_fraglen(hdroom + xlen);
 
-	/*
-	 * 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 = 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);
 
···
 	struct vmbus_channel *channel = nvchan->channel;
 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
 	struct sk_buff *skb;
-	struct netvsc_stats *rx_stats;
+	struct netvsc_stats *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_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);
+	skb = netvsc_alloc_recv_skb(net, nvchan, &xdp);
 
 	if (unlikely(!skb)) {
 		++net_device_ctx->eth_stats.rx_no_memory;
···
 	 * on the synthetic device because modifying the VF device
 	 * statistics will not work correctly.
 	 */
-	rx_stats = &nvchan->rx_stats;
 	u64_stats_update_begin(&rx_stats->syncp);
 	rx_stats->packets++;
 	rx_stats->bytes += nvchan->rsc.pktlen;
···
 	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;
···
 /* 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)
+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);
 
···
 		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;
···
 
 		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;
···
 	}
 
 	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,
···
 	/* 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)) {
···
 	struct hv_device *hdev = ndev_ctx->device_ctx;
 	struct netvsc_device *nvdev;
 	struct rndis_device *rdev;
-	int ret;
+	struct bpf_prog *prog;
+	int ret = 0;
 
 	nvdev = rndis_filter_device_add(hdev, dev_info);
 	if (IS_ERR(nvdev))
···
 		}
 	}
 
+	prog = dev_info->bprog;
+	if (prog) {
+		ret = netvsc_xdp_set(ndev, prog, NULL, nvdev);
+		if (ret)
+			goto err1;
+	}
+
 	/* In any case device is now ready */
 	netif_device_attach(ndev);
 
···
 	if (netif_running(ndev)) {
 		ret = rndis_filter_open(nvdev);
 		if (ret)
-			goto err;
+			goto err2;
 
 		rdev = nvdev->extension;
 		if (!rdev->link_state)
···
 
 	return 0;
 
-err:
+err2:
 	netif_device_detach(ndev);
 
+err1:
 	rndis_filter_device_remove(hdev, nvdev);
 
 	return ret;
···
 	}
 
 out:
-	kfree(device_info);
+	netvsc_devinfo_put(device_info);
 	return ret;
 }
 
···
 		dev_set_mtu(vf_netdev, orig_mtu);
 
 out:
-	kfree(device_info);
+	netvsc_devinfo_put(device_info);
 	return ret;
 }
 
···
 /* statistics per queue (rx/tx packets/bytes) */
 #define NETVSC_PCPU_STATS_LEN (num_present_cpus() * ARRAY_SIZE(pcpu_stats))
 
-/* 4 statistics per queue (rx/tx packets/bytes) */
-#define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 4)
+/* 5 statistics per queue (rx/tx packets/bytes, rx xdp_drop) */
+#define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 5)
 
 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
 {
···
 	struct netvsc_ethtool_pcpu_stats *pcpu_sum;
 	unsigned int start;
 	u64 packets, bytes;
+	u64 xdp_drop;
 	int i, j, cpu;
 
 	if (!nvdev)
···
 			start = u64_stats_fetch_begin_irq(&qstats->syncp);
 			packets = qstats->packets;
 			bytes = qstats->bytes;
+			xdp_drop = qstats->xdp_drop;
 		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
 		data[i++] = packets;
 		data[i++] = bytes;
+		data[i++] = xdp_drop;
 	}
 
 	pcpu_sum = kvmalloc_array(num_possible_cpus(),
···
 			sprintf(p, "rx_queue_%u_packets", i);
 			p += ETH_GSTRING_LEN;
 			sprintf(p, "rx_queue_%u_bytes", i);
+			p += ETH_GSTRING_LEN;
+			sprintf(p, "rx_queue_%u_xdp_drop", i);
 			p += ETH_GSTRING_LEN;
 		}
 
···
 	}
 
 out:
-	kfree(device_info);
+	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,
···
 	.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,
 };
 
 /*
···
 {
 	struct net_device_context *net_device_ctx;
 	struct netvsc_device *netvsc_dev;
+	struct bpf_prog *prog;
 	struct net_device *ndev;
 	int ret;
 
···
 	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;
 }
 
···
 	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);
···
 	list_add(&net_device_ctx->list, &netvsc_dev_list);
 	rtnl_unlock();
 
-	kfree(device_info);
+	netvsc_devinfo_put(device_info);
 	return 0;
 
 register_failed:
 	rtnl_unlock();
 	rndis_filter_device_remove(dev, nvdev);
 rndis_failed:
-	kfree(device_info);
+	netvsc_devinfo_put(device_info);
 devinfo_failed:
 	free_percpu(net_device_ctx->vf_stats);
 no_stats:
···
 
 	rtnl_lock();
 	nvdev = rtnl_dereference(ndev_ctx->nvdev);
-	if (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
···
 
 	ret = netvsc_attach(net, device_info);
 
-	rtnl_unlock();
-
-	kfree(device_info);
+	netvsc_devinfo_put(device_info);
 	net_device_ctx->saved_netvsc_dev_info = NULL;
+
+	rtnl_unlock();
 
 	return ret;
 }

drivers/net/hyperv/rndis_filter.c

···
 	trace_rndis_send(dev->ndev, 0, &req->request_msg);
 
 	rcu_read_lock_bh();
-	ret = netvsc_send(dev->ndev, packet, NULL, pb, NULL);
+	ret = netvsc_send(dev->ndev, packet, NULL, pb, NULL, false);
 	rcu_read_unlock_bh();
 
 	return ret;