linux-kernel - Re: [PATCH v3] hv_netvsc: Set VF priv_flags to IFF_NO_ADDRCONF before open to prevent IPv6 addrconf

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Message-ID: <20250716092927.GO721198@horms.kernel.org>
Date: Wed, 16 Jul 2025 10:29:27 +0100
From: Simon Horman <horms@...nel.org>
To: Li Tian <litian@...hat.com>
Cc: netdev@...r.kernel.org, linux-hyperv@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Haiyang Zhang <haiyangz@...rosoft.com>,
	Dexuan Cui <decui@...rosoft.com>,
	Stephen Hemminger <stephen@...workplumber.org>,
	Long Li <longli@...rosoft.com>, Xin Long <lucien.xin@...il.com>
Subject: Re: [PATCH v3] hv_netvsc: Set VF priv_flags to IFF_NO_ADDRCONF
 before open to prevent IPv6 addrconf

+ Xin Long

On Wed, Jul 16, 2025 at 08:26:05AM +0800, Li Tian wrote:
> Set an additional flag IFF_NO_ADDRCONF to prevent ipv6 addrconf.
> 
> Commit under Fixes added a new flag change that was not made
> to hv_netvsc resulting in the VF being assinged an IPv6.
> 
> Fixes: 8a321cf7becc ("net: add IFF_NO_ADDRCONF and use it in bonding to prevent ipv6 addrconf")
> Suggested-by: Cathy Avery <cavery@...hat.com>
> Signed-off-by: Li Tian <litian@...hat.com>
> ---
> v3:
>   - only fixes commit message.
> v2: https://lore.kernel.org/netdev/20250710024603.10162-1-litian@redhat.com/
>   - instead of replacing flag, add it.
> v1: https://lore.kernel.org/netdev/20250710024603.10162-1-litian@redhat.com/
> ---
>  drivers/net/hyperv/netvsc_drv.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Hi Li Tian,

Thanks for addressing earlier feedback.

I don't think you need to repost because of this, but for future reference:

1. Because this is a fix for a commit that is present in net
   it should be targeted at that tree.

   Subject: [PATCH net vX] ...

2. Please use get_maintainers.pl this.patch to generate the CC list. In
   this case Xin Long (now CCed) should be included as he is the author of the
   patch cited in the Fixes tag.

   b4 can help you with this and other aspects of patch management.

> 
> 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
> 
>