Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 2026 insertions, 0 deletions

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
new file mode 100644
index 000000000..6ed3ee811
--- /dev/null
+++ b/drivers/net/veth.c
@@ -0,0 +1,2026 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  drivers/net/veth.c
+ *
+ *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
+ *
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
+ *
+ */
+
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/ethtool.h>
+#include <linux/etherdevice.h>
+#include <linux/u64_stats_sync.h>
+
+#include <net/rtnetlink.h>
+#include <net/dst.h>
+#include <net/netdev_lock.h>
+#include <net/xfrm.h>
+#include <net/xdp.h>
+#include <linux/veth.h>
+#include <linux/module.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/ptr_ring.h>
+#include <linux/bpf_trace.h>
+#include <linux/net_tstamp.h>
+#include <linux/skbuff_ref.h>
+#include <net/page_pool/helpers.h>
+
+#define DRV_NAME	"veth"
+#define DRV_VERSION	"1.0"
+
+#define VETH_XDP_FLAG		BIT(0)
+#define VETH_RING_SIZE		256
+#define VETH_XDP_HEADROOM	(XDP_PACKET_HEADROOM + NET_IP_ALIGN)
+
+#define VETH_XDP_TX_BULK_SIZE	16
+#define VETH_XDP_BATCH		16
+
+struct veth_stats {
+	u64	rx_drops;
+	/* xdp */
+	u64	xdp_packets;
+	u64	xdp_bytes;
+	u64	xdp_redirect;
+	u64	xdp_drops;
+	u64	xdp_tx;
+	u64	xdp_tx_err;
+	u64	peer_tq_xdp_xmit;
+	u64	peer_tq_xdp_xmit_err;
+};
+
+struct veth_rq_stats {
+	struct veth_stats	vs;
+	struct u64_stats_sync	syncp;
+};
+
+struct veth_rq {
+	struct napi_struct	xdp_napi;
+	struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
+	struct net_device	*dev;
+	struct bpf_prog __rcu	*xdp_prog;
+	struct xdp_mem_info	xdp_mem;
+	struct veth_rq_stats	stats;
+	bool			rx_notify_masked;
+	struct ptr_ring		xdp_ring;
+	struct xdp_rxq_info	xdp_rxq;
+	struct page_pool	*page_pool;
+};
+
+struct veth_priv {
+	struct net_device __rcu	*peer;
+	atomic64_t		dropped;
+	struct bpf_prog		*_xdp_prog;
+	struct veth_rq		*rq;
+	unsigned int		requested_headroom;
+	netdevice_tracker	peer_tracker;
+};
+
+struct veth_xdp_tx_bq {
+	struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
+	unsigned int count;
+};
+
+/*
+ * ethtool interface
+ */
+
+struct veth_q_stat_desc {
+	char	desc[ETH_GSTRING_LEN];
+	size_t	offset;
+};
+
+#define VETH_RQ_STAT(m)	offsetof(struct veth_stats, m)
+
+static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
+	{ "xdp_packets",	VETH_RQ_STAT(xdp_packets) },
+	{ "xdp_bytes",		VETH_RQ_STAT(xdp_bytes) },
+	{ "drops",		VETH_RQ_STAT(rx_drops) },
+	{ "xdp_redirect",	VETH_RQ_STAT(xdp_redirect) },
+	{ "xdp_drops",		VETH_RQ_STAT(xdp_drops) },
+	{ "xdp_tx",		VETH_RQ_STAT(xdp_tx) },
+	{ "xdp_tx_errors",	VETH_RQ_STAT(xdp_tx_err) },
+};
+
+#define VETH_RQ_STATS_LEN	ARRAY_SIZE(veth_rq_stats_desc)
+
+static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
+	{ "xdp_xmit",		VETH_RQ_STAT(peer_tq_xdp_xmit) },
+	{ "xdp_xmit_errors",	VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
+};
+
+#define VETH_TQ_STATS_LEN	ARRAY_SIZE(veth_tq_stats_desc)
+
+static struct {
+	const char string[ETH_GSTRING_LEN];
+} ethtool_stats_keys[] = {
+	{ "peer_ifindex" },
+};
+
+struct veth_xdp_buff {
+	struct xdp_buff xdp;
+	struct sk_buff *skb;
+};
+
+static int veth_get_link_ksettings(struct net_device *dev,
+				   struct ethtool_link_ksettings *cmd)
+{
+	cmd->base.speed		= SPEED_10000;
+	cmd->base.duplex	= DUPLEX_FULL;
+	cmd->base.port		= PORT_TP;
+	cmd->base.autoneg	= AUTONEG_DISABLE;
+	return 0;
+}
+
+static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
+	strscpy(info->version, DRV_VERSION, sizeof(info->version));
+}
+
+static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+	u8 *p = buf;
+	int i, j;
+
+	switch(stringset) {
+	case ETH_SS_STATS:
+		memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
+		p += sizeof(ethtool_stats_keys);
+		for (i = 0; i < dev->real_num_rx_queues; i++)
+			for (j = 0; j < VETH_RQ_STATS_LEN; j++)
+				ethtool_sprintf(&p, "rx_queue_%u_%.18s",
+						i, veth_rq_stats_desc[j].desc);
+
+		for (i = 0; i < dev->real_num_tx_queues; i++)
+			for (j = 0; j < VETH_TQ_STATS_LEN; j++)
+				ethtool_sprintf(&p, "tx_queue_%u_%.18s",
+						i, veth_tq_stats_desc[j].desc);
+
+		page_pool_ethtool_stats_get_strings(p);
+		break;
+	}
+}
+
+static int veth_get_sset_count(struct net_device *dev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(ethtool_stats_keys) +
+		       VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
+		       VETH_TQ_STATS_LEN * dev->real_num_tx_queues +
+		       page_pool_ethtool_stats_get_count();
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static void veth_get_page_pool_stats(struct net_device *dev, u64 *data)
+{
+#ifdef CONFIG_PAGE_POOL_STATS
+	struct veth_priv *priv = netdev_priv(dev);
+	struct page_pool_stats pp_stats = {};
+	int i;
+
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		if (!priv->rq[i].page_pool)
+			continue;
+		page_pool_get_stats(priv->rq[i].page_pool, &pp_stats);
+	}
+	page_pool_ethtool_stats_get(data, &pp_stats);
+#endif /* CONFIG_PAGE_POOL_STATS */
+}
+
+static void veth_get_ethtool_stats(struct net_device *dev,
+		struct ethtool_stats *stats, u64 *data)
+{
+	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+	int i, j, idx, pp_idx;
+
+	data[0] = peer ? peer->ifindex : 0;
+	idx = 1;
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
+		const void *stats_base = (void *)&rq_stats->vs;
+		unsigned int start;
+		size_t offset;
+
+		do {
+			start = u64_stats_fetch_begin(&rq_stats->syncp);
+			for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
+				offset = veth_rq_stats_desc[j].offset;
+				data[idx + j] = *(u64 *)(stats_base + offset);
+			}
+		} while (u64_stats_fetch_retry(&rq_stats->syncp, start));
+		idx += VETH_RQ_STATS_LEN;
+	}
+	pp_idx = idx;
+
+	if (!peer)
+		goto page_pool_stats;
+
+	rcv_priv = netdev_priv(peer);
+	for (i = 0; i < peer->real_num_rx_queues; i++) {
+		const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
+		const void *base = (void *)&rq_stats->vs;
+		unsigned int start, tx_idx = idx;
+		u64 buf[VETH_TQ_STATS_LEN];
+		size_t offset;
+
+		do {
+			start = u64_stats_fetch_begin(&rq_stats->syncp);
+			for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
+				offset = veth_tq_stats_desc[j].offset;
+				buf[j] = *(u64 *)(base + offset);
+			}
+		} while (u64_stats_fetch_retry(&rq_stats->syncp, start));
+
+		tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
+		for (j = 0; j < VETH_TQ_STATS_LEN; j++)
+			data[tx_idx + j] += buf[j];
+	}
+	pp_idx = idx + dev->real_num_tx_queues * VETH_TQ_STATS_LEN;
+
+page_pool_stats:
+	veth_get_page_pool_stats(dev, &data[pp_idx]);
+}
+
+static void veth_get_channels(struct net_device *dev,
+			      struct ethtool_channels *channels)
+{
+	channels->tx_count = dev->real_num_tx_queues;
+	channels->rx_count = dev->real_num_rx_queues;
+	channels->max_tx = dev->num_tx_queues;
+	channels->max_rx = dev->num_rx_queues;
+}
+
+static int veth_set_channels(struct net_device *dev,
+			     struct ethtool_channels *ch);
+
+static const struct ethtool_ops veth_ethtool_ops = {
+	.get_drvinfo		= veth_get_drvinfo,
+	.get_link		= ethtool_op_get_link,
+	.get_strings		= veth_get_strings,
+	.get_sset_count		= veth_get_sset_count,
+	.get_ethtool_stats	= veth_get_ethtool_stats,
+	.get_link_ksettings	= veth_get_link_ksettings,
+	.get_ts_info		= ethtool_op_get_ts_info,
+	.get_channels		= veth_get_channels,
+	.set_channels		= veth_set_channels,
+};
+
+/* general routines */
+
+static bool veth_is_xdp_frame(void *ptr)
+{
+	return (unsigned long)ptr & VETH_XDP_FLAG;
+}
+
+static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
+{
+	return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
+}
+
+static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
+{
+	return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
+}
+
+static void veth_ptr_free(void *ptr)
+{
+	if (veth_is_xdp_frame(ptr))
+		xdp_return_frame(veth_ptr_to_xdp(ptr));
+	else
+		kfree_skb(ptr);
+}
+
+static void __veth_xdp_flush(struct veth_rq *rq)
+{
+	/* Write ptr_ring before reading rx_notify_masked */
+	smp_mb();
+	if (!READ_ONCE(rq->rx_notify_masked) &&
+	    napi_schedule_prep(&rq->xdp_napi)) {
+		WRITE_ONCE(rq->rx_notify_masked, true);
+		__napi_schedule(&rq->xdp_napi);
+	}
+}
+
+static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
+{
+	if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb)))
+		return NETDEV_TX_BUSY; /* signal qdisc layer */
+
+	return NET_RX_SUCCESS; /* same as NETDEV_TX_OK */
+}
+
+static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
+			    struct veth_rq *rq, bool xdp)
+{
+	return __dev_forward_skb(dev, skb) ?: xdp ?
+		veth_xdp_rx(rq, skb) :
+		__netif_rx(skb);
+}
+
+/* return true if the specified skb has chances of GRO aggregation
+ * Don't strive for accuracy, but try to avoid GRO overhead in the most
+ * common scenarios.
+ * When XDP is enabled, all traffic is considered eligible, as the xmit
+ * device has TSO off.
+ * When TSO is enabled on the xmit device, we are likely interested only
+ * in UDP aggregation, explicitly check for that if the skb is suspected
+ * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
+ * to belong to locally generated UDP traffic.
+ */
+static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
+					 const struct net_device *rcv,
+					 const struct sk_buff *skb)
+{
+	return !(dev->features & NETIF_F_ALL_TSO) ||
+		(skb->destructor == sock_wfree &&
+		 rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
+}
+
+static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+	struct veth_rq *rq = NULL;
+	struct netdev_queue *txq;
+	struct net_device *rcv;
+	int length = skb->len;
+	bool use_napi = false;
+	int ret, rxq;
+
+	rcu_read_lock();
+	rcv = rcu_dereference(priv->peer);
+	if (unlikely(!rcv) || !pskb_may_pull(skb, ETH_HLEN)) {
+		kfree_skb(skb);
+		goto drop;
+	}
+
+	rcv_priv = netdev_priv(rcv);
+	rxq = skb_get_queue_mapping(skb);
+	if (rxq < rcv->real_num_rx_queues) {
+		rq = &rcv_priv->rq[rxq];
+
+		/* The napi pointer is available when an XDP program is
+		 * attached or when GRO is enabled
+		 * Don't bother with napi/GRO if the skb can't be aggregated
+		 */
+		use_napi = rcu_access_pointer(rq->napi) &&
+			   veth_skb_is_eligible_for_gro(dev, rcv, skb);
+	}
+
+	skb_tx_timestamp(skb);
+
+	ret = veth_forward_skb(rcv, skb, rq, use_napi);
+	switch (ret) {
+	case NET_RX_SUCCESS: /* same as NETDEV_TX_OK */
+		if (!use_napi)
+			dev_sw_netstats_tx_add(dev, 1, length);
+		else
+			__veth_xdp_flush(rq);
+		break;
+	case NETDEV_TX_BUSY:
+		/* If a qdisc is attached to our virtual device, returning
+		 * NETDEV_TX_BUSY is allowed.
+		 */
+		txq = netdev_get_tx_queue(dev, rxq);
+
+		if (qdisc_txq_has_no_queue(txq)) {
+			dev_kfree_skb_any(skb);
+			goto drop;
+		}
+		/* Restore Eth hdr pulled by dev_forward_skb/eth_type_trans */
+		__skb_push(skb, ETH_HLEN);
+		netif_tx_stop_queue(txq);
+		/* Makes sure NAPI peer consumer runs. Consumer is responsible
+		 * for starting txq again, until then ndo_start_xmit (this
+		 * function) will not be invoked by the netstack again.
+		 */
+		__veth_xdp_flush(rq);
+		break;
+	case NET_RX_DROP: /* same as NET_XMIT_DROP */
+drop:
+		atomic64_inc(&priv->dropped);
+		ret = NET_XMIT_DROP;
+		break;
+	default:
+		net_crit_ratelimited("%s(%s): Invalid return code(%d)",
+				     __func__, dev->name, ret);
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	result->peer_tq_xdp_xmit_err = 0;
+	result->xdp_packets = 0;
+	result->xdp_tx_err = 0;
+	result->xdp_bytes = 0;
+	result->rx_drops = 0;
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
+		struct veth_rq_stats *stats = &priv->rq[i].stats;
+		unsigned int start;
+
+		do {
+			start = u64_stats_fetch_begin(&stats->syncp);
+			peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
+			xdp_tx_err = stats->vs.xdp_tx_err;
+			packets = stats->vs.xdp_packets;
+			bytes = stats->vs.xdp_bytes;
+			drops = stats->vs.rx_drops;
+		} while (u64_stats_fetch_retry(&stats->syncp, start));
+		result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
+		result->xdp_tx_err += xdp_tx_err;
+		result->xdp_packets += packets;
+		result->xdp_bytes += bytes;
+		result->rx_drops += drops;
+	}
+}
+
+static void veth_get_stats64(struct net_device *dev,
+			     struct rtnl_link_stats64 *tot)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+	struct veth_stats rx;
+
+	tot->tx_dropped = atomic64_read(&priv->dropped);
+	dev_fetch_sw_netstats(tot, dev->tstats);
+
+	veth_stats_rx(&rx, dev);
+	tot->tx_dropped += rx.xdp_tx_err;
+	tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
+	tot->rx_bytes += rx.xdp_bytes;
+	tot->rx_packets += rx.xdp_packets;
+
+	rcu_read_lock();
+	peer = rcu_dereference(priv->peer);
+	if (peer) {
+		struct rtnl_link_stats64 tot_peer = {};
+
+		dev_fetch_sw_netstats(&tot_peer, peer->tstats);
+		tot->rx_bytes += tot_peer.tx_bytes;
+		tot->rx_packets += tot_peer.tx_packets;
+
+		veth_stats_rx(&rx, peer);
+		tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
+		tot->rx_dropped += rx.xdp_tx_err;
+		tot->tx_bytes += rx.xdp_bytes;
+		tot->tx_packets += rx.xdp_packets;
+	}
+	rcu_read_unlock();
+}
+
+/* fake multicast ability */
+static void veth_set_multicast_list(struct net_device *dev)
+{
+}
+
+static int veth_select_rxq(struct net_device *dev)
+{
+	return smp_processor_id() % dev->real_num_rx_queues;
+}
+
+static struct net_device *veth_peer_dev(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+
+	/* Callers must be under RCU read side. */
+	return rcu_dereference(priv->peer);
+}
+
+static int veth_xdp_xmit(struct net_device *dev, int n,
+			 struct xdp_frame **frames,
+			 u32 flags, bool ndo_xmit)
+{
+	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+	int i, ret = -ENXIO, nxmit = 0;
+	struct net_device *rcv;
+	unsigned int max_len;
+	struct veth_rq *rq;
+
+	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+		return -EINVAL;
+
+	rcu_read_lock();
+	rcv = rcu_dereference(priv->peer);
+	if (unlikely(!rcv))
+		goto out;
+
+	rcv_priv = netdev_priv(rcv);
+	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
+	/* The napi pointer is set if NAPI is enabled, which ensures that
+	 * xdp_ring is initialized on receive side and the peer device is up.
+	 */
+	if (!rcu_access_pointer(rq->napi))
+		goto out;
+
+	max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
+
+	spin_lock(&rq->xdp_ring.producer_lock);
+	for (i = 0; i < n; i++) {
+		struct xdp_frame *frame = frames[i];
+		void *ptr = veth_xdp_to_ptr(frame);
+
+		if (unlikely(xdp_get_frame_len(frame) > max_len ||
+			     __ptr_ring_produce(&rq->xdp_ring, ptr)))
+			break;
+		nxmit++;
+	}
+	spin_unlock(&rq->xdp_ring.producer_lock);
+
+	if (flags & XDP_XMIT_FLUSH)
+		__veth_xdp_flush(rq);
+
+	ret = nxmit;
+	if (ndo_xmit) {
+		u64_stats_update_begin(&rq->stats.syncp);
+		rq->stats.vs.peer_tq_xdp_xmit += nxmit;
+		rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
+		u64_stats_update_end(&rq->stats.syncp);
+	}
+
+out:
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
+			     struct xdp_frame **frames, u32 flags)
+{
+	int err;
+
+	err = veth_xdp_xmit(dev, n, frames, flags, true);
+	if (err < 0) {
+		struct veth_priv *priv = netdev_priv(dev);
+
+		atomic64_add(n, &priv->dropped);
+	}
+
+	return err;
+}
+
+static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
+{
+	int sent, i, err = 0, drops;
+
+	sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
+	if (sent < 0) {
+		err = sent;
+		sent = 0;
+	}
+
+	for (i = sent; unlikely(i < bq->count); i++)
+		xdp_return_frame(bq->q[i]);
+
+	drops = bq->count - sent;
+	trace_xdp_bulk_tx(rq->dev, sent, drops, err);
+
+	u64_stats_update_begin(&rq->stats.syncp);
+	rq->stats.vs.xdp_tx += sent;
+	rq->stats.vs.xdp_tx_err += drops;
+	u64_stats_update_end(&rq->stats.syncp);
+
+	bq->count = 0;
+}
+
+static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
+{
+	struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
+	struct net_device *rcv;
+	struct veth_rq *rcv_rq;
+
+	rcu_read_lock();
+	veth_xdp_flush_bq(rq, bq);
+	rcv = rcu_dereference(priv->peer);
+	if (unlikely(!rcv))
+		goto out;
+
+	rcv_priv = netdev_priv(rcv);
+	rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
+	/* xdp_ring is initialized on receive side? */
+	if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
+		goto out;
+
+	__veth_xdp_flush(rcv_rq);
+out:
+	rcu_read_unlock();
+}
+
+static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
+		       struct veth_xdp_tx_bq *bq)
+{
+	struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
+
+	if (unlikely(!frame))
+		return -EOVERFLOW;
+
+	if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
+		veth_xdp_flush_bq(rq, bq);
+
+	bq->q[bq->count++] = frame;
+
+	return 0;
+}
+
+static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
+					  struct xdp_frame *frame,
+					  struct veth_xdp_tx_bq *bq,
+					  struct veth_stats *stats)
+{
+	struct xdp_frame orig_frame;
+	struct bpf_prog *xdp_prog;
+
+	rcu_read_lock();
+	xdp_prog = rcu_dereference(rq->xdp_prog);
+	if (likely(xdp_prog)) {
+		struct veth_xdp_buff vxbuf;
+		struct xdp_buff *xdp = &vxbuf.xdp;
+		u32 act;
+
+		xdp_convert_frame_to_buff(frame, xdp);
+		xdp->rxq = &rq->xdp_rxq;
+		vxbuf.skb = NULL;
+
+		act = bpf_prog_run_xdp(xdp_prog, xdp);
+
+		switch (act) {
+		case XDP_PASS:
+			if (xdp_update_frame_from_buff(xdp, frame))
+				goto err_xdp;
+			break;
+		case XDP_TX:
+			orig_frame = *frame;
+			xdp->rxq->mem.type = frame->mem_type;
+			if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
+				trace_xdp_exception(rq->dev, xdp_prog, act);
+				frame = &orig_frame;
+				stats->rx_drops++;
+				goto err_xdp;
+			}
+			stats->xdp_tx++;
+			rcu_read_unlock();
+			goto xdp_xmit;
+		case XDP_REDIRECT:
+			orig_frame = *frame;
+			xdp->rxq->mem.type = frame->mem_type;
+			if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
+				frame = &orig_frame;
+				stats->rx_drops++;
+				goto err_xdp;
+			}
+			stats->xdp_redirect++;
+			rcu_read_unlock();
+			goto xdp_xmit;
+		default:
+			bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
+			fallthrough;
+		case XDP_ABORTED:
+			trace_xdp_exception(rq->dev, xdp_prog, act);
+			fallthrough;
+		case XDP_DROP:
+			stats->xdp_drops++;
+			goto err_xdp;
+		}
+	}
+	rcu_read_unlock();
+
+	return frame;
+err_xdp:
+	rcu_read_unlock();
+	xdp_return_frame(frame);
+xdp_xmit:
+	return NULL;
+}
+
+/* frames array contains VETH_XDP_BATCH at most */
+static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
+				  int n_xdpf, struct veth_xdp_tx_bq *bq,
+				  struct veth_stats *stats)
+{
+	void *skbs[VETH_XDP_BATCH];
+	int i;
+
+	if (unlikely(!napi_skb_cache_get_bulk(skbs, n_xdpf))) {
+		for (i = 0; i < n_xdpf; i++)
+			xdp_return_frame(frames[i]);
+		stats->rx_drops += n_xdpf;
+
+		return;
+	}
+
+	for (i = 0; i < n_xdpf; i++) {
+		struct sk_buff *skb = skbs[i];
+
+		skb = __xdp_build_skb_from_frame(frames[i], skb,
+						 rq->dev);
+		if (!skb) {
+			xdp_return_frame(frames[i]);
+			stats->rx_drops++;
+			continue;
+		}
+		napi_gro_receive(&rq->xdp_napi, skb);
+	}
+}
+
+static void veth_xdp_get(struct xdp_buff *xdp)
+{
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
+	int i;
+
+	get_page(virt_to_page(xdp->data));
+	if (likely(!xdp_buff_has_frags(xdp)))
+		return;
+
+	for (i = 0; i < sinfo->nr_frags; i++)
+		__skb_frag_ref(&sinfo->frags[i]);
+}
+
+static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
+					struct xdp_buff *xdp,
+					struct sk_buff **pskb)
+{
+	struct sk_buff *skb = *pskb;
+	u32 frame_sz;
+
+	if (skb_shared(skb) || skb_head_is_locked(skb) ||
+	    skb_is_nonlinear(skb) ||
+	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
+		if (skb_pp_cow_data(rq->page_pool, pskb, XDP_PACKET_HEADROOM))
+			goto drop;
+
+		skb = *pskb;
+	}
+
+	/* SKB "head" area always have tailroom for skb_shared_info */
+	frame_sz = skb_end_pointer(skb) - skb->head;
+	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+	xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
+	xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
+			 skb_headlen(skb), true);
+
+	if (skb_shinfo(skb)->nr_frags) {
+		skb_shinfo(skb)->xdp_frags_size = skb->data_len;
+		xdp_buff_set_frags_flag(xdp);
+	} else {
+		xdp_buff_clear_frags_flag(xdp);
+	}
+	*pskb = skb;
+
+	return 0;
+drop:
+	consume_skb(skb);
+	*pskb = NULL;
+
+	return -ENOMEM;
+}
+
+static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
+					struct sk_buff *skb,
+					struct veth_xdp_tx_bq *bq,
+					struct veth_stats *stats)
+{
+	void *orig_data, *orig_data_end;
+	struct bpf_prog *xdp_prog;
+	struct veth_xdp_buff vxbuf;
+	struct xdp_buff *xdp = &vxbuf.xdp;
+	u32 act, metalen;
+	int off;
+
+	skb_prepare_for_gro(skb);
+
+	rcu_read_lock();
+	xdp_prog = rcu_dereference(rq->xdp_prog);
+	if (unlikely(!xdp_prog)) {
+		rcu_read_unlock();
+		goto out;
+	}
+
+	__skb_push(skb, skb->data - skb_mac_header(skb));
+	if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
+		goto drop;
+	vxbuf.skb = skb;
+
+	orig_data = xdp->data;
+	orig_data_end = xdp->data_end;
+
+	act = bpf_prog_run_xdp(xdp_prog, xdp);
+
+	switch (act) {
+	case XDP_PASS:
+		break;
+	case XDP_TX:
+		veth_xdp_get(xdp);
+		consume_skb(skb);
+		xdp->rxq->mem = rq->xdp_mem;
+		if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
+			trace_xdp_exception(rq->dev, xdp_prog, act);
+			stats->rx_drops++;
+			goto err_xdp;
+		}
+		stats->xdp_tx++;
+		rcu_read_unlock();
+		goto xdp_xmit;
+	case XDP_REDIRECT:
+		veth_xdp_get(xdp);
+		consume_skb(skb);
+		xdp->rxq->mem = rq->xdp_mem;
+		if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
+			stats->rx_drops++;
+			goto err_xdp;
+		}
+		stats->xdp_redirect++;
+		rcu_read_unlock();
+		goto xdp_xmit;
+	default:
+		bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
+		fallthrough;
+	case XDP_ABORTED:
+		trace_xdp_exception(rq->dev, xdp_prog, act);
+		fallthrough;
+	case XDP_DROP:
+		stats->xdp_drops++;
+		goto xdp_drop;
+	}
+	rcu_read_unlock();
+
+	/* check if bpf_xdp_adjust_head was used */
+	off = orig_data - xdp->data;
+	if (off > 0)
+		__skb_push(skb, off);
+	else if (off < 0)
+		__skb_pull(skb, -off);
+
+	skb_reset_mac_header(skb);
+
+	/* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
+	 * (e.g. bpf_xdp_adjust_tail). Remove the old fragment contribution
+	 * from skb->len before updating data_len, then add the new one back.
+	 */
+	skb->len -= skb->data_len;
+	if (xdp_buff_has_frags(xdp)) {
+		skb->data_len = skb_shinfo(skb)->xdp_frags_size;
+		skb->len += skb->data_len;
+	} else {
+		skb->data_len = 0;
+	}
+
+	/* Synchronize the skb tail with XDP's updated linear area. */
+	off = xdp->data_end - orig_data_end;
+	if (off != 0) {
+		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
+		skb->len += off; /* positive on grow, negative on shrink */
+	}
+
+	skb->protocol = eth_type_trans(skb, rq->dev);
+
+	metalen = xdp->data - xdp->data_meta;
+	if (metalen)
+		skb_metadata_set(skb, metalen);
+out:
+	return skb;
+drop:
+	stats->rx_drops++;
+xdp_drop:
+	rcu_read_unlock();
+	kfree_skb(skb);
+	return NULL;
+err_xdp:
+	rcu_read_unlock();
+	xdp_return_buff(xdp);
+xdp_xmit:
+	return NULL;
+}
+
+static int veth_xdp_rcv(struct veth_rq *rq, int budget,
+			struct veth_xdp_tx_bq *bq,
+			struct veth_stats *stats)
+{
+	int i, done = 0, n_xdpf = 0;
+	void *xdpf[VETH_XDP_BATCH];
+
+	for (i = 0; i < budget; i++) {
+		void *ptr = __ptr_ring_consume(&rq->xdp_ring);
+
+		if (!ptr)
+			break;
+
+		if (veth_is_xdp_frame(ptr)) {
+			/* ndo_xdp_xmit */
+			struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
+
+			stats->xdp_bytes += xdp_get_frame_len(frame);
+			frame = veth_xdp_rcv_one(rq, frame, bq, stats);
+			if (frame) {
+				/* XDP_PASS */
+				xdpf[n_xdpf++] = frame;
+				if (n_xdpf == VETH_XDP_BATCH) {
+					veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
+							      bq, stats);
+					n_xdpf = 0;
+				}
+			}
+		} else {
+			/* ndo_start_xmit */
+			struct sk_buff *skb = ptr;
+
+			stats->xdp_bytes += skb->len;
+			skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
+			if (skb) {
+				if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
+					netif_receive_skb(skb);
+				else
+					napi_gro_receive(&rq->xdp_napi, skb);
+			}
+		}
+		done++;
+	}
+
+	if (n_xdpf)
+		veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
+
+	u64_stats_update_begin(&rq->stats.syncp);
+	rq->stats.vs.xdp_redirect += stats->xdp_redirect;
+	rq->stats.vs.xdp_bytes += stats->xdp_bytes;
+	rq->stats.vs.xdp_drops += stats->xdp_drops;
+	rq->stats.vs.rx_drops += stats->rx_drops;
+	rq->stats.vs.xdp_packets += done;
+	u64_stats_update_end(&rq->stats.syncp);
+
+	return done;
+}
+
+static int veth_poll(struct napi_struct *napi, int budget)
+{
+	struct veth_rq *rq =
+		container_of(napi, struct veth_rq, xdp_napi);
+	struct veth_priv *priv = netdev_priv(rq->dev);
+	int queue_idx = rq - priv->rq;
+	struct netdev_queue *peer_txq;
+	struct veth_stats stats = {};
+	struct net_device *peer_dev;
+	struct veth_xdp_tx_bq bq;
+	int done;
+
+	bq.count = 0;
+
+	/* NAPI functions as RCU section */
+	peer_dev = rcu_dereference_check(priv->peer, rcu_read_lock_bh_held());
+	peer_txq = (peer_dev && queue_idx < peer_dev->real_num_tx_queues) ?
+		   netdev_get_tx_queue(peer_dev, queue_idx) : NULL;
+
+	xdp_set_return_frame_no_direct();
+	done = veth_xdp_rcv(rq, budget, &bq, &stats);
+
+	if (stats.xdp_redirect > 0)
+		xdp_do_flush();
+	if (stats.xdp_tx > 0)
+		veth_xdp_flush(rq, &bq);
+	xdp_clear_return_frame_no_direct();
+
+	if (done < budget && napi_complete_done(napi, done)) {
+		/* Write rx_notify_masked before reading ptr_ring */
+		smp_store_mb(rq->rx_notify_masked, false);
+		if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
+			if (napi_schedule_prep(&rq->xdp_napi)) {
+				WRITE_ONCE(rq->rx_notify_masked, true);
+				__napi_schedule(&rq->xdp_napi);
+			}
+		}
+	}
+
+	/* Release backpressure per NAPI poll */
+	smp_rmb(); /* Paired with netif_tx_stop_queue set_bit */
+	if (peer_txq && netif_tx_queue_stopped(peer_txq)) {
+		txq_trans_cond_update(peer_txq);
+		netif_tx_wake_queue(peer_txq);
+	}
+
+	return done;
+}
+
+static int veth_create_page_pool(struct veth_rq *rq)
+{
+	struct page_pool_params pp_params = {
+		.order = 0,
+		.pool_size = VETH_RING_SIZE,
+		.nid = NUMA_NO_NODE,
+		.dev = &rq->dev->dev,
+	};
+
+	rq->page_pool = page_pool_create(&pp_params);
+	if (IS_ERR(rq->page_pool)) {
+		int err = PTR_ERR(rq->page_pool);
+
+		rq->page_pool = NULL;
+		return err;
+	}
+
+	return 0;
+}
+
+static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int err, i;
+
+	for (i = start; i < end; i++) {
+		err = veth_create_page_pool(&priv->rq[i]);
+		if (err)
+			goto err_page_pool;
+	}
+
+	for (i = start; i < end; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
+		if (err)
+			goto err_xdp_ring;
+	}
+
+	for (i = start; i < end; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		napi_enable(&rq->xdp_napi);
+		rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
+	}
+
+	return 0;
+
+err_xdp_ring:
+	for (i--; i >= start; i--)
+		ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
+	i = end;
+err_page_pool:
+	for (i--; i >= start; i--) {
+		page_pool_destroy(priv->rq[i].page_pool);
+		priv->rq[i].page_pool = NULL;
+	}
+
+	return err;
+}
+
+static int __veth_napi_enable(struct net_device *dev)
+{
+	return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
+}
+
+static void veth_napi_del_range(struct net_device *dev, int start, int end)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	for (i = start; i < end; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		rcu_assign_pointer(priv->rq[i].napi, NULL);
+		napi_disable(&rq->xdp_napi);
+		__netif_napi_del(&rq->xdp_napi);
+	}
+	synchronize_net();
+
+	for (i = start; i < end; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		rq->rx_notify_masked = false;
+		ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
+	}
+
+	for (i = start; i < end; i++) {
+		page_pool_destroy(priv->rq[i].page_pool);
+		priv->rq[i].page_pool = NULL;
+	}
+}
+
+static void veth_napi_del(struct net_device *dev)
+{
+	veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
+}
+
+static bool veth_gro_requested(const struct net_device *dev)
+{
+	return !!(dev->wanted_features & NETIF_F_GRO);
+}
+
+static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
+				 bool napi_already_on)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int err, i;
+
+	for (i = start; i < end; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		if (!napi_already_on)
+			netif_napi_add(dev, &rq->xdp_napi, veth_poll);
+		err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
+		if (err < 0)
+			goto err_rxq_reg;
+
+		err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
+						 MEM_TYPE_PAGE_SHARED,
+						 NULL);
+		if (err < 0)
+			goto err_reg_mem;
+
+		/* Save original mem info as it can be overwritten */
+		rq->xdp_mem = rq->xdp_rxq.mem;
+	}
+	return 0;
+
+err_reg_mem:
+	xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
+err_rxq_reg:
+	if (!napi_already_on)
+		netif_napi_del(&priv->rq[i].xdp_napi);
+	for (i--; i >= start; i--) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		xdp_rxq_info_unreg(&rq->xdp_rxq);
+		if (!napi_already_on)
+			netif_napi_del(&rq->xdp_napi);
+	}
+
+	return err;
+}
+
+static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
+				   bool delete_napi)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	for (i = start; i < end; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		rq->xdp_rxq.mem = rq->xdp_mem;
+		xdp_rxq_info_unreg(&rq->xdp_rxq);
+
+		if (delete_napi)
+			netif_napi_del(&rq->xdp_napi);
+	}
+}
+
+static int veth_enable_xdp(struct net_device *dev)
+{
+	bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
+	struct veth_priv *priv = netdev_priv(dev);
+	int err, i;
+
+	if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
+		err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
+		if (err)
+			return err;
+
+		if (!napi_already_on) {
+			err = __veth_napi_enable(dev);
+			if (err) {
+				veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
+				return err;
+			}
+		}
+	}
+
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
+		rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
+	}
+
+	return 0;
+}
+
+static void veth_disable_xdp(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	for (i = 0; i < dev->real_num_rx_queues; i++)
+		rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
+
+	if (!netif_running(dev) || !veth_gro_requested(dev))
+		veth_napi_del(dev);
+
+	veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
+}
+
+static int veth_napi_enable_range(struct net_device *dev, int start, int end)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int err, i;
+
+	for (i = start; i < end; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		netif_napi_add(dev, &rq->xdp_napi, veth_poll);
+	}
+
+	err = __veth_napi_enable_range(dev, start, end);
+	if (err) {
+		for (i = start; i < end; i++) {
+			struct veth_rq *rq = &priv->rq[i];
+
+			netif_napi_del(&rq->xdp_napi);
+		}
+		return err;
+	}
+	return err;
+}
+
+static int veth_napi_enable(struct net_device *dev)
+{
+	return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
+}
+
+static void veth_disable_range_safe(struct net_device *dev, int start, int end)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+
+	if (start >= end)
+		return;
+
+	if (priv->_xdp_prog) {
+		veth_napi_del_range(dev, start, end);
+		veth_disable_xdp_range(dev, start, end, false);
+	} else if (veth_gro_requested(dev)) {
+		veth_napi_del_range(dev, start, end);
+	}
+}
+
+static int veth_enable_range_safe(struct net_device *dev, int start, int end)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int err;
+
+	if (start >= end)
+		return 0;
+
+	if (priv->_xdp_prog) {
+		/* these channels are freshly initialized, napi is not on there even
+		 * when GRO is requeste
+		 */
+		err = veth_enable_xdp_range(dev, start, end, false);
+		if (err)
+			return err;
+
+		err = __veth_napi_enable_range(dev, start, end);
+		if (err) {
+			/* on error always delete the newly added napis */
+			veth_disable_xdp_range(dev, start, end, true);
+			return err;
+		}
+	} else if (veth_gro_requested(dev)) {
+		return veth_napi_enable_range(dev, start, end);
+	}
+	return 0;
+}
+
+static void veth_set_xdp_features(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+
+	peer = rtnl_dereference(priv->peer);
+	if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
+		struct veth_priv *priv_peer = netdev_priv(peer);
+		xdp_features_t val = NETDEV_XDP_ACT_BASIC |
+				     NETDEV_XDP_ACT_REDIRECT |
+				     NETDEV_XDP_ACT_RX_SG;
+
+		if (priv_peer->_xdp_prog || veth_gro_requested(peer))
+			val |= NETDEV_XDP_ACT_NDO_XMIT |
+			       NETDEV_XDP_ACT_NDO_XMIT_SG;
+		xdp_set_features_flag(dev, val);
+	} else {
+		xdp_clear_features_flag(dev);
+	}
+}
+
+static int veth_set_channels(struct net_device *dev,
+			     struct ethtool_channels *ch)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	unsigned int old_rx_count, new_rx_count;
+	struct veth_priv *peer_priv;
+	struct net_device *peer;
+	int err;
+
+	/* sanity check. Upper bounds are already enforced by the caller */
+	if (!ch->rx_count || !ch->tx_count)
+		return -EINVAL;
+
+	/* avoid braking XDP, if that is enabled */
+	peer = rtnl_dereference(priv->peer);
+	peer_priv = peer ? netdev_priv(peer) : NULL;
+	if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
+		return -EINVAL;
+
+	if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
+		return -EINVAL;
+
+	old_rx_count = dev->real_num_rx_queues;
+	new_rx_count = ch->rx_count;
+	if (netif_running(dev)) {
+		/* turn device off */
+		netif_carrier_off(dev);
+		if (peer)
+			netif_carrier_off(peer);
+
+		/* try to allocate new resources, as needed*/
+		err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
+		if (err)
+			goto out;
+	}
+
+	err = netif_set_real_num_rx_queues(dev, ch->rx_count);
+	if (err)
+		goto revert;
+
+	err = netif_set_real_num_tx_queues(dev, ch->tx_count);
+	if (err) {
+		int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
+
+		/* this error condition could happen only if rx and tx change
+		 * in opposite directions (e.g. tx nr raises, rx nr decreases)
+		 * and we can't do anything to fully restore the original
+		 * status
+		 */
+		if (err2)
+			pr_warn("Can't restore rx queues config %d -> %d %d",
+				new_rx_count, old_rx_count, err2);
+		else
+			goto revert;
+	}
+
+out:
+	if (netif_running(dev)) {
+		/* note that we need to swap the arguments WRT the enable part
+		 * to identify the range we have to disable
+		 */
+		veth_disable_range_safe(dev, new_rx_count, old_rx_count);
+		netif_carrier_on(dev);
+		if (peer)
+			netif_carrier_on(peer);
+	}
+
+	/* update XDP supported features */
+	veth_set_xdp_features(dev);
+	if (peer)
+		veth_set_xdp_features(peer);
+
+	return err;
+
+revert:
+	new_rx_count = old_rx_count;
+	old_rx_count = ch->rx_count;
+	goto out;
+}
+
+static int veth_open(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+	int err;
+
+	if (!peer)
+		return -ENOTCONN;
+
+	if (priv->_xdp_prog) {
+		err = veth_enable_xdp(dev);
+		if (err)
+			return err;
+	} else if (veth_gro_requested(dev)) {
+		err = veth_napi_enable(dev);
+		if (err)
+			return err;
+	}
+
+	if (peer->flags & IFF_UP) {
+		netif_carrier_on(dev);
+		netif_carrier_on(peer);
+	}
+
+	veth_set_xdp_features(dev);
+
+	return 0;
+}
+
+static int veth_close(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+
+	netif_carrier_off(dev);
+	if (peer)
+		netif_carrier_off(peer);
+
+	if (priv->_xdp_prog)
+		veth_disable_xdp(dev);
+	else if (veth_gro_requested(dev))
+		veth_napi_del(dev);
+
+	return 0;
+}
+
+static int is_valid_veth_mtu(int mtu)
+{
+	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
+}
+
+static int veth_alloc_queues(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	priv->rq = kvzalloc_objs(*priv->rq, dev->num_rx_queues,
+				 GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
+	if (!priv->rq)
+		return -ENOMEM;
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		priv->rq[i].dev = dev;
+		u64_stats_init(&priv->rq[i].stats.syncp);
+	}
+
+	return 0;
+}
+
+static void veth_free_queues(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+
+	kvfree(priv->rq);
+}
+
+static int veth_dev_init(struct net_device *dev)
+{
+	netdev_lockdep_set_classes(dev);
+	return veth_alloc_queues(dev);
+}
+
+static void veth_dev_free(struct net_device *dev)
+{
+	veth_free_queues(dev);
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void veth_poll_controller(struct net_device *dev)
+{
+	/* veth only receives frames when its peer sends one
+	 * Since it has nothing to do with disabling irqs, we are guaranteed
+	 * never to have pending data when we poll for it so
+	 * there is nothing to do here.
+	 *
+	 * We need this though so netpoll recognizes us as an interface that
+	 * supports polling, which enables bridge devices in virt setups to
+	 * still use netconsole
+	 */
+}
+#endif	/* CONFIG_NET_POLL_CONTROLLER */
+
+static int veth_get_iflink(const struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+	int iflink;
+
+	rcu_read_lock();
+	peer = rcu_dereference(priv->peer);
+	iflink = peer ? READ_ONCE(peer->ifindex) : 0;
+	rcu_read_unlock();
+
+	return iflink;
+}
+
+static netdev_features_t veth_fix_features(struct net_device *dev,
+					   netdev_features_t features)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+
+	peer = rtnl_dereference(priv->peer);
+	if (peer) {
+		struct veth_priv *peer_priv = netdev_priv(peer);
+
+		if (peer_priv->_xdp_prog)
+			features &= ~NETIF_F_GSO_SOFTWARE;
+	}
+
+	return features;
+}
+
+static int veth_set_features(struct net_device *dev,
+			     netdev_features_t features)
+{
+	netdev_features_t changed = features ^ dev->features;
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+	int err;
+
+	if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
+		return 0;
+
+	peer = rtnl_dereference(priv->peer);
+	if (features & NETIF_F_GRO) {
+		err = veth_napi_enable(dev);
+		if (err)
+			return err;
+
+		if (peer)
+			xdp_features_set_redirect_target(peer, true);
+	} else {
+		if (peer)
+			xdp_features_clear_redirect_target(peer);
+		veth_napi_del(dev);
+	}
+	return 0;
+}
+
+static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
+{
+	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
+	struct net_device *peer;
+
+	if (new_hr < 0)
+		new_hr = 0;
+
+	rcu_read_lock();
+	peer = rcu_dereference(priv->peer);
+	if (unlikely(!peer))
+		goto out;
+
+	peer_priv = netdev_priv(peer);
+	priv->requested_headroom = new_hr;
+	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
+	dev->needed_headroom = new_hr;
+	peer->needed_headroom = new_hr;
+
+out:
+	rcu_read_unlock();
+}
+
+static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
+			struct netlink_ext_ack *extack)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct bpf_prog *old_prog;
+	struct net_device *peer;
+	unsigned int max_mtu;
+	int err;
+
+	old_prog = priv->_xdp_prog;
+	priv->_xdp_prog = prog;
+	peer = rtnl_dereference(priv->peer);
+
+	if (prog) {
+		if (!peer) {
+			NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
+			err = -ENOTCONN;
+			goto err;
+		}
+
+		max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
+			  peer->hard_header_len;
+		/* Allow increasing the max_mtu if the program supports
+		 * XDP fragments.
+		 */
+		if (prog->aux->xdp_has_frags)
+			max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
+
+		if (peer->mtu > max_mtu) {
+			NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
+			err = -ERANGE;
+			goto err;
+		}
+
+		if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
+			NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
+			err = -ENOSPC;
+			goto err;
+		}
+
+		if (dev->flags & IFF_UP) {
+			err = veth_enable_xdp(dev);
+			if (err) {
+				NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
+				goto err;
+			}
+		}
+
+		if (!old_prog) {
+			peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
+			peer->max_mtu = max_mtu;
+		}
+
+		xdp_features_set_redirect_target(peer, true);
+	}
+
+	if (old_prog) {
+		if (!prog) {
+			if (peer && !veth_gro_requested(dev))
+				xdp_features_clear_redirect_target(peer);
+
+			if (dev->flags & IFF_UP)
+				veth_disable_xdp(dev);
+
+			if (peer) {
+				peer->hw_features |= NETIF_F_GSO_SOFTWARE;
+				peer->max_mtu = ETH_MAX_MTU;
+			}
+		}
+		bpf_prog_put(old_prog);
+	}
+
+	if ((!!old_prog ^ !!prog) && peer)
+		netdev_update_features(peer);
+
+	return 0;
+err:
+	priv->_xdp_prog = old_prog;
+
+	return err;
+}
+
+static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+	switch (xdp->command) {
+	case XDP_SETUP_PROG:
+		return veth_xdp_set(dev, xdp->prog, xdp->extack);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
+{
+	struct veth_xdp_buff *_ctx = (void *)ctx;
+
+	if (!_ctx->skb)
+		return -ENODATA;
+
+	*timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
+	return 0;
+}
+
+static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
+			    enum xdp_rss_hash_type *rss_type)
+{
+	struct veth_xdp_buff *_ctx = (void *)ctx;
+	struct sk_buff *skb = _ctx->skb;
+
+	if (!skb)
+		return -ENODATA;
+
+	*hash = skb_get_hash(skb);
+	*rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
+
+	return 0;
+}
+
+static int veth_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
+				u16 *vlan_tci)
+{
+	const struct veth_xdp_buff *_ctx = (void *)ctx;
+	const struct sk_buff *skb = _ctx->skb;
+	int err;
+
+	if (!skb)
+		return -ENODATA;
+
+	err = __vlan_hwaccel_get_tag(skb, vlan_tci);
+	if (err)
+		return err;
+
+	*vlan_proto = skb->vlan_proto;
+	return err;
+}
+
+static const struct net_device_ops veth_netdev_ops = {
+	.ndo_init            = veth_dev_init,
+	.ndo_open            = veth_open,
+	.ndo_stop            = veth_close,
+	.ndo_start_xmit      = veth_xmit,
+	.ndo_get_stats64     = veth_get_stats64,
+	.ndo_set_rx_mode     = veth_set_multicast_list,
+	.ndo_set_mac_address = eth_mac_addr,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller	= veth_poll_controller,
+#endif
+	.ndo_get_iflink		= veth_get_iflink,
+	.ndo_fix_features	= veth_fix_features,
+	.ndo_set_features	= veth_set_features,
+	.ndo_features_check	= passthru_features_check,
+	.ndo_set_rx_headroom	= veth_set_rx_headroom,
+	.ndo_bpf		= veth_xdp,
+	.ndo_xdp_xmit		= veth_ndo_xdp_xmit,
+	.ndo_get_peer_dev	= veth_peer_dev,
+};
+
+static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
+	.xmo_rx_timestamp		= veth_xdp_rx_timestamp,
+	.xmo_rx_hash			= veth_xdp_rx_hash,
+	.xmo_rx_vlan_tag		= veth_xdp_rx_vlan_tag,
+};
+
+#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
+		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
+		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
+		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
+		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
+
+static void veth_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	dev->priv_flags |= IFF_NO_QUEUE;
+	dev->priv_flags |= IFF_PHONY_HEADROOM;
+	dev->priv_flags |= IFF_DISABLE_NETPOLL;
+	dev->lltx = true;
+
+	dev->netdev_ops = &veth_netdev_ops;
+	dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
+	dev->ethtool_ops = &veth_ethtool_ops;
+	dev->features |= VETH_FEATURES;
+	dev->vlan_features = dev->features &
+			     ~(NETIF_F_HW_VLAN_CTAG_TX |
+			       NETIF_F_HW_VLAN_STAG_TX |
+			       NETIF_F_HW_VLAN_CTAG_RX |
+			       NETIF_F_HW_VLAN_STAG_RX);
+	dev->needs_free_netdev = true;
+	dev->priv_destructor = veth_dev_free;
+	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
+	dev->max_mtu = ETH_MAX_MTU;
+
+	dev->hw_features = VETH_FEATURES;
+	dev->hw_enc_features = VETH_FEATURES;
+	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
+	netif_set_tso_max_size(dev, GSO_MAX_SIZE);
+}
+
+/*
+ * netlink interface
+ */
+
+static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
+			 struct netlink_ext_ack *extack)
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+			return -EINVAL;
+		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+			return -EADDRNOTAVAIL;
+	}
+	if (tb[IFLA_MTU]) {
+		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static struct rtnl_link_ops veth_link_ops;
+
+static void veth_disable_gro(struct net_device *dev)
+{
+	dev->features &= ~NETIF_F_GRO;
+	dev->wanted_features &= ~NETIF_F_GRO;
+	netdev_update_features(dev);
+}
+
+static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
+{
+	int err;
+
+	if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
+		err = netif_set_real_num_tx_queues(dev, 1);
+		if (err)
+			return err;
+	}
+	if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
+		err = netif_set_real_num_rx_queues(dev, 1);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+static int veth_newlink(struct net_device *dev,
+			struct rtnl_newlink_params *params,
+			struct netlink_ext_ack *extack)
+{
+	struct net *peer_net = rtnl_newlink_peer_net(params);
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
+	int err;
+	struct net_device *peer;
+	struct veth_priv *priv;
+	char ifname[IFNAMSIZ];
+	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
+	unsigned char name_assign_type;
+	struct ifinfomsg *ifmp;
+
+	/*
+	 * create and register peer first
+	 */
+	if (data && data[VETH_INFO_PEER]) {
+		struct nlattr *nla_peer = data[VETH_INFO_PEER];
+
+		ifmp = nla_data(nla_peer);
+		rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
+		tbp = peer_tb;
+	} else {
+		ifmp = NULL;
+		tbp = tb;
+	}
+
+	if (ifmp && tbp[IFLA_IFNAME]) {
+		nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
+		name_assign_type = NET_NAME_USER;
+	} else {
+		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
+		name_assign_type = NET_NAME_ENUM;
+	}
+
+	peer = rtnl_create_link(peer_net, ifname, name_assign_type,
+				&veth_link_ops, tbp, extack);
+	if (IS_ERR(peer))
+		return PTR_ERR(peer);
+
+	if (!ifmp || !tbp[IFLA_ADDRESS])
+		eth_hw_addr_random(peer);
+
+	if (ifmp && (dev->ifindex != 0))
+		peer->ifindex = ifmp->ifi_index;
+
+	netif_inherit_tso_max(peer, dev);
+
+	err = register_netdevice(peer);
+	if (err < 0)
+		goto err_register_peer;
+
+	/* keep GRO disabled by default to be consistent with the established
+	 * veth behavior
+	 */
+	veth_disable_gro(peer);
+	netif_carrier_off(peer);
+
+	err = rtnl_configure_link(peer, ifmp, 0, NULL);
+	if (err < 0)
+		goto err_configure_peer;
+
+	/*
+	 * register dev last
+	 *
+	 * note, that since we've registered new device the dev's name
+	 * should be re-allocated
+	 */
+
+	if (tb[IFLA_ADDRESS] == NULL)
+		eth_hw_addr_random(dev);
+
+	if (tb[IFLA_IFNAME])
+		nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
+	else
+		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
+
+	err = register_netdevice(dev);
+	if (err < 0)
+		goto err_register_dev;
+
+	netif_carrier_off(dev);
+
+	/*
+	 * tie the deviced together
+	 */
+
+	priv = netdev_priv(dev);
+	rcu_assign_pointer(priv->peer, peer);
+	netdev_hold(peer, &priv->peer_tracker, GFP_KERNEL);
+	err = veth_init_queues(dev, tb);
+	if (err)
+		goto err_queues;
+
+	priv = netdev_priv(peer);
+	rcu_assign_pointer(priv->peer, dev);
+	netdev_hold(dev, &priv->peer_tracker, GFP_KERNEL);
+	err = veth_init_queues(peer, tb);
+	if (err)
+		goto err_peer_queues;
+
+	veth_disable_gro(dev);
+	/* update XDP supported features */
+	veth_set_xdp_features(dev);
+	veth_set_xdp_features(peer);
+
+	return 0;
+
+err_peer_queues:
+	netdev_put(dev, &priv->peer_tracker);
+	priv = netdev_priv(dev);
+err_queues:
+	netdev_put(peer, &priv->peer_tracker);
+	unregister_netdevice(dev);
+err_register_dev:
+	/* nothing to do */
+err_configure_peer:
+	unregister_netdevice(peer);
+	return err;
+
+err_register_peer:
+	free_netdev(peer);
+	return err;
+}
+
+static void veth_dellink(struct net_device *dev, struct list_head *head)
+{
+	netdevice_tracker *peer_tracker;
+	struct net_device *peer;
+	struct veth_priv *priv;
+
+	priv = netdev_priv(dev);
+	peer_tracker = &priv->peer_tracker;
+	peer = unrcu_pointer(xchg(&priv->peer, NULL));
+	if (!peer)
+		return;
+
+	unregister_netdevice_queue(dev, head);
+
+	priv = netdev_priv(peer);
+	dev = unrcu_pointer(xchg(&priv->peer, NULL));
+	if (dev)
+		unregister_netdevice_queue_net(dev_net(dev), peer, head);
+
+	netdev_put(peer, peer_tracker);
+	netdev_put(dev, &priv->peer_tracker);
+}
+
+static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
+	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
+};
+
+static struct net *veth_get_link_net(const struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+
+	return peer ? dev_net(peer) : dev_net(dev);
+}
+
+static unsigned int veth_get_num_queues(void)
+{
+	/* enforce the same queue limit as rtnl_create_link */
+	int queues = num_possible_cpus();
+
+	if (queues > 4096)
+		queues = 4096;
+	return queues;
+}
+
+static struct rtnl_link_ops veth_link_ops = {
+	.kind		= DRV_NAME,
+	.priv_size	= sizeof(struct veth_priv),
+	.setup		= veth_setup,
+	.validate	= veth_validate,
+	.newlink	= veth_newlink,
+	.dellink	= veth_dellink,
+	.policy		= veth_policy,
+	.peer_type	= VETH_INFO_PEER,
+	.maxtype	= VETH_INFO_MAX,
+	.get_link_net	= veth_get_link_net,
+	.get_num_tx_queues	= veth_get_num_queues,
+	.get_num_rx_queues	= veth_get_num_queues,
+};
+
+/*
+ * init/fini
+ */
+
+static __init int veth_init(void)
+{
+	return rtnl_link_register(&veth_link_ops);
+}
+
+static __exit void veth_exit(void)
+{
+	rtnl_link_unregister(&veth_link_ops);
+}
+
+module_init(veth_init);
+module_exit(veth_exit);
+
+MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_RTNL_LINK(DRV_NAME);