Re: [PATCH] RDMA/rxe: Add network namespace support

["yanjun.zhu" <yanjun.zhu@linux.dev>]

On 2/25/26 9:26 AM, David Ahern wrote:
> Allow rxe to work across network namespaces by making the sockets
> per namespace using net_generic. Defer socket initialization until
> a device is created in the namespace.

https://github.com/zhuyj/linux/tree/upstream/6.14-net-namespace

Do you make tests with the above link?

Compared with the net namespace in the above link, what is the 
difference between this commit and the above link?

Thanks a lot.
Yanjun.Zhu

> 
> Signed-off-by: David Ahern <dsahern@kernel.org>
> ---
>   drivers/infiniband/sw/rxe/rxe_net.c | 123 ++++++++++++++++++++--------
>   1 file changed, 88 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
> index 0bd0902b11f7..f51afc38c9df 100644
> --- a/drivers/infiniband/sw/rxe/rxe_net.c
> +++ b/drivers/infiniband/sw/rxe/rxe_net.c
> @@ -18,7 +18,10 @@
>   #include "rxe_net.h"
>   #include "rxe_loc.h"
>   
> -static struct rxe_recv_sockets recv_sockets;
> +static int __rxe_netns_init(struct net *net,
> +			    struct rxe_recv_sockets *sockets);
> +
> +static unsigned int rxe_net_id;
>   
>   #ifdef CONFIG_DEBUG_LOCK_ALLOC
>   /*
> @@ -105,6 +108,7 @@ static struct dst_entry *rxe_find_route4(struct rxe_qp *qp,
>   					 struct in_addr *saddr,
>   					 struct in_addr *daddr)
>   {
> +	struct net *net = dev_net(ndev);
>   	struct rtable *rt;
>   	struct flowi4 fl = { { 0 } };
>   
> @@ -114,7 +118,7 @@ static struct dst_entry *rxe_find_route4(struct rxe_qp *qp,
>   	memcpy(&fl.daddr, daddr, sizeof(*daddr));
>   	fl.flowi4_proto = IPPROTO_UDP;
>   
> -	rt = ip_route_output_key(&init_net, &fl);
> +	rt = ip_route_output_key(net, &fl);
>   	if (IS_ERR(rt)) {
>   		rxe_dbg_qp(qp, "no route to %pI4\n", &daddr->s_addr);
>   		return NULL;
> @@ -129,6 +133,8 @@ static struct dst_entry *rxe_find_route6(struct rxe_qp *qp,
>   					 struct in6_addr *saddr,
>   					 struct in6_addr *daddr)
>   {
> +	struct net *net = dev_net(ndev);
> +	struct rxe_recv_sockets *recv_socket = net_generic(net, rxe_net_id);
>   	struct dst_entry *ndst;
>   	struct flowi6 fl6 = { { 0 } };
>   
> @@ -138,9 +144,8 @@ static struct dst_entry *rxe_find_route6(struct rxe_qp *qp,
>   	memcpy(&fl6.daddr, daddr, sizeof(*daddr));
>   	fl6.flowi6_proto = IPPROTO_UDP;
>   
> -	ndst = ipv6_stub->ipv6_dst_lookup_flow(sock_net(recv_sockets.sk6->sk),
> -					       recv_sockets.sk6->sk, &fl6,
> -					       NULL);
> +	ndst = ipv6_stub->ipv6_dst_lookup_flow(net, recv_socket->sk6->sk,
> +					       &fl6, NULL);
>   	if (IS_ERR(ndst)) {
>   		rxe_dbg_qp(qp, "no route to %pI6\n", daddr);
>   		return NULL;
> @@ -606,8 +611,16 @@ const char *rxe_parent_name(struct rxe_dev *rxe, unsigned int port_num)
>   
>   int rxe_net_add(const char *ibdev_name, struct net_device *ndev)
>   {
> -	int err;
> +	struct net *net = dev_net(ndev);
> +	struct rxe_recv_sockets *sockets = net_generic(net, rxe_net_id);
>   	struct rxe_dev *rxe = NULL;
> +	int err;
> +
> +	if (!sockets->sk4) {
> +		err = __rxe_netns_init(net, sockets);
> +		if (err)
> +			return err;
> +	}
>   
>   	rxe = ib_alloc_device(rxe_dev, ib_dev);
>   	if (!rxe)
> @@ -709,12 +722,13 @@ static struct notifier_block rxe_net_notifier = {
>   	.notifier_call = rxe_notify,
>   };
>   
> -static int rxe_net_ipv4_init(void)
> +static int rxe_net_ipv4_init(struct net *net,
> +			     struct rxe_recv_sockets *sockets)
>   {
> -	recv_sockets.sk4 = rxe_setup_udp_tunnel(&init_net,
> -				htons(ROCE_V2_UDP_DPORT), false);
> -	if (IS_ERR(recv_sockets.sk4)) {
> -		recv_sockets.sk4 = NULL;
> +	sockets->sk4 = rxe_setup_udp_tunnel(net, htons(ROCE_V2_UDP_DPORT),
> +					    false);
> +	if (IS_ERR(sockets->sk4)) {
> +		sockets->sk4 = NULL;
>   		pr_err("Failed to create IPv4 UDP tunnel\n");
>   		return -1;
>   	}
> @@ -722,31 +736,74 @@ static int rxe_net_ipv4_init(void)
>   	return 0;
>   }
>   
> -static int rxe_net_ipv6_init(void)
> -{
>   #if IS_ENABLED(CONFIG_IPV6)
> -
> -	recv_sockets.sk6 = rxe_setup_udp_tunnel(&init_net,
> -						htons(ROCE_V2_UDP_DPORT), true);
> -	if (PTR_ERR(recv_sockets.sk6) == -EAFNOSUPPORT) {
> -		recv_sockets.sk6 = NULL;
> -		pr_warn("IPv6 is not supported, can not create a UDPv6 socket\n");
> -		return 0;
> -	}
> -
> -	if (IS_ERR(recv_sockets.sk6)) {
> -		recv_sockets.sk6 = NULL;
> +static int rxe_net_ipv6_init(struct net *net,
> +			     struct rxe_recv_sockets *sockets)
> +{
> +	sockets->sk6 = rxe_setup_udp_tunnel(net, htons(ROCE_V2_UDP_DPORT),
> +					    true);
> +	if (IS_ERR(sockets->sk6)) {
> +		sockets->sk6 = NULL;
>   		pr_err("Failed to create IPv6 UDP tunnel\n");
>   		return -1;
>   	}
> +	return 0;
> +}
> +#endif
> +
> +/* Initialize per network namespace state */
> +static int __rxe_netns_init(struct net *net,
> +			    struct rxe_recv_sockets *sockets)
> +{
> +	int err;
> +
> +	err = rxe_net_ipv4_init(net, sockets);
> +	if (err)
> +		return err;
> +
> +#if IS_ENABLED(CONFIG_IPV6)
> +	err = rxe_net_ipv6_init(net, sockets);
> +	if (err) {
> +		rxe_release_udp_tunnel(sockets->sk4);
> +		return err;
> +	}
>   #endif
> +
> +	return 0;
> +}
> +
> +static int __net_init rxe_netns_init(struct net *net)
> +{
> +	/* defer socket create in the namespace to the first
> +	 * device create.
> +	 */
>   	return 0;
>   }
>   
> +static void __net_exit rxe_netns_exit(struct net *net)
> +{
> +	struct rxe_recv_sockets *sockets;
> +
> +	sockets = net_generic(net, rxe_net_id);
> +
> +#if IS_ENABLED(CONFIG_IPV6)
> +	if (sockets->sk6)
> +		rxe_release_udp_tunnel(sockets->sk6);
> +#endif
> +	if (sockets->sk4)
> +		rxe_release_udp_tunnel(sockets->sk4);
> +}
> +
> +static struct pernet_operations rxe_net_ops __net_initdata = {
> +	.init = rxe_netns_init,
> +	.exit = rxe_netns_exit,
> +	.id   = &rxe_net_id,
> +	.size = sizeof(struct rxe_recv_sockets),
> +};
> +
>   void rxe_net_exit(void)
>   {
> -	rxe_release_udp_tunnel(recv_sockets.sk6);
> -	rxe_release_udp_tunnel(recv_sockets.sk4);
> +	unregister_pernet_device(&rxe_net_ops);
>   	unregister_netdevice_notifier(&rxe_net_notifier);
>   }
>   
> @@ -754,21 +811,17 @@ int rxe_net_init(void)
>   {
>   	int err;
>   
> -	recv_sockets.sk6 = NULL;
> -
> -	err = rxe_net_ipv4_init();
> -	if (err)
> -		return err;
> -	err = rxe_net_ipv6_init();
> -	if (err)
> -		goto err_out;
>   	err = register_netdevice_notifier(&rxe_net_notifier);
>   	if (err) {
>   		pr_err("Failed to register netdev notifier\n");
>   		goto err_out;
>   	}
> +	err = register_pernet_device(&rxe_net_ops);
> +	if (err)
> +		goto err_out;
> +
>   	return 0;
>   err_out:
> -	rxe_net_exit();
> +	unregister_netdevice_notifier(&rxe_net_notifier);
>   	return err;
>   }