Re: [PATCH 2/2] hv_netvsc: Use VF's tso_max_size value when data path is VF

[Stephen Hemminger]

On Tue,  4 Feb 2025 20:21:55 -0800
Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx> wrote:

> On Azure, increasing VF's TCP segment size to up-to GSO_MAX_SIZE
> is not possible without allowing the same for netvsc NIC
> (as the NICs are bonded together). For bonded NICs, the min of the max
> segment size of the members is propagated in the stack.
> 
> Therefore, we use netif_set_tso_max_size() to set max segment size
> to VF's segment size for netvsc too, when the data path is switched over
> to the VF
> Tested on azure env with Accelerated Networking enabled and disabled.
> 
> Signed-off-by: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>

Since datapath can change at anytime (ie hot remove of VF).
How does TCP stack react to GSO max size changing underneath it.
Is it like a path MTU change where some packets are lost until
TCP retries and has to rediscover?