Re: [PATCH RESEND] netvsc: transfer lower device max tso size

[Jakub Kicinski]

On Tue, 22 Jul 2025 09:04:20 +0800 Jason Wang wrote:
> On Tue, Jul 22, 2025 at 7:28 AM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
> > On Fri, 18 Jul 2025 14:17:55 +0800 Cindy Lu wrote:  
> > > Subject: [PATCH RESEND] netvsc: transfer lower device max tso size  
> >
> > You say RESEND but I don't see a link to previous posting anywhere.

Someone should respond to this part, please.

> > I'd rather we didn't extend the magic behavior of hyperv/netvsc any
> > further.  
> 
> Are you referring to the netdev coupling model of the VF acceleration?

Yes, it tries to apply whole bunch of policy automatically in 
the kernel.

> > We have enough problems with it.
> 
> But this fixes a real problem, otherwise nested VM performance will be
> broken due to the GSO software segmentation.

Perhaps, possibly, a migration plan can be devised, away from the
netvsc model, so we don't have to deal with nuggets of joy like:
https://lore.kernel.org/all/1752870014-28909-1-git-send-email-haiyangz@xxxxxxxxxxxxxxxxxxx/