Add an additional flag IFF_NO_ADDRCONF to prevent ipv6 addrconf.

Commit 8a321cf7becc6c065ae595b837b826a2a81036b9
("net: add IFF_NO_ADDRCONF and use it in bonding to prevent ipv6 addrconf")

This new flag change was not made to hv_netvsc resulting in the VF being
assinged an IPv6.

Suggested-by: Cathy Avery <cavery@redhat.com>

Signed-off-by: Li Tian <litian@redhat.com>
---
 drivers/net/hyperv/netvsc_drv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index c41a025c66f0..8be9bce66a4e 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2317,8 +2317,11 @@ static int netvsc_prepare_bonding(struct net_device *vf_netdev)
 	if (!ndev)
 		return NOTIFY_DONE;
 
-	/* set slave flag before open to prevent IPv6 addrconf */
+	/* Set slave flag and no addrconf flag before open
+	 * to prevent IPv6 addrconf.
+	 */
 	vf_netdev->flags |= IFF_SLAVE;
+	vf_netdev->priv_flags |= IFF_NO_ADDRCONF;
 	return NOTIFY_DONE;
 }
 
-- 
2.50.0

On Fri, 11 Jul 2025 11:39:58 +0800
Li Tian <litian@redhat.com> wrote:

> Add an additional flag IFF_NO_ADDRCONF to prevent ipv6 addrconf.
> 
> Commit 8a321cf7becc6c065ae595b837b826a2a81036b9
> ("net: add IFF_NO_ADDRCONF and use it in bonding to prevent ipv6 addrconf")
> 
> This new flag change was not made to hv_netvsc resulting in the VF being
> assinged an IPv6.
> 
> Suggested-by: Cathy Avery <cavery@redhat.com>
> 
> Signed-off-by: Li Tian <litian@redhat.com>
> ---
>  drivers/net/hyperv/netvsc_drv.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index c41a025c66f0..8be9bce66a4e 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -2317,8 +2317,11 @@ static int netvsc_prepare_bonding(struct net_device *vf_netdev)
>  	if (!ndev)
>  		return NOTIFY_DONE;
>  
> -	/* set slave flag before open to prevent IPv6 addrconf */
> +	/* Set slave flag and no addrconf flag before open
> +	 * to prevent IPv6 addrconf.
> +	 */
>  	vf_netdev->flags |= IFF_SLAVE;
> +	vf_netdev->priv_flags |= IFF_NO_ADDRCONF;
>  	return NOTIFY_DONE;
>  }
>  


Thanks this worked originally but got broken, please add:

Fixes: 8a321cf7becc ("net: add IFF_NO_ADDRCONF and use it in bonding to prevent ipv6 addrconf")
Cc: lucien.xin@gmail.com

Looks like team and failover have the same problem.