Re: [PATCH v4 net-next 10/12] veth: enable BIG TCP packets

From: Jakub Kicinski <kuba@kernel.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "David S . Miller" <davem@davemloft.net>,
	Paolo Abeni <pabeni@redhat.com>, netdev <netdev@vger.kernel.org>,
	Coco Li <lixiaoyan@google.com>,
	Eric Dumazet <edumazet@google.com>
Subject: Re: [PATCH v4 net-next 10/12] veth: enable BIG TCP packets
Date: Fri, 6 May 2022 15:33:39 -0700	[thread overview]
Message-ID: <20220506153339.70a78f84@kernel.org> (raw)
In-Reply-To: <20220506153048.3695721-11-eric.dumazet@gmail.com>

On Fri,  6 May 2022 08:30:46 -0700 Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
> 
> Set the driver limit to 512 KB per TSO ipv6 packet.
> 
> This allows the admin/user to set a GSO ipv6 limit up to this value.
> 
> ip link set dev veth10 gso_ipv6_max_size 200000
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/veth.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> index f474e79a774580e4cb67da44b5f0c796c3ce8abb..989248b0f0c64349494a54735bb5abac66a42a93 100644
> --- a/drivers/net/veth.c
> +++ b/drivers/net/veth.c
> @@ -1647,6 +1647,7 @@ static void veth_setup(struct net_device *dev)
>  	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, 512 * 1024);

Should we have a define for a "good SW device limit" ?
Or set it to infinity (TSO_MAX_SIZE)?

>  }