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

[Stephen Hemminger]

On Wed, 23 Jul 2025 15:16:22 -0700
Jakub Kicinski <kuba@xxxxxxxxxx> wrote:

> On Wed, 23 Jul 2025 20:18:03 +0000 Haiyang Zhang wrote:
> > > > Btw, if I understand this correctly. This is for future development so
> > > > it's not a blocker for this patch?    
> > >
> > > Not a blocker, I'm just giving an example of the netvsc auto-weirdness
> > > being a source of tech debt and bugs. Commit d7501e076d859d is another
> > > recent one off the top of my head. IIUC systemd-networkd is broadly
> > > deployed now. It'd be great if there was some migration plan for moving
> > > this sort of VM auto-bonding to user space (with the use of the common
> > > bonding driver, not each hypervisor rolling its own).    
> > 
> > Actually, we had used the common bonding driver 9 years ago. But it's
> > replaced by this kernel/netvsc based "transparent" bonding mode. See
> > the patches listed below.
> > 
> > The user mode bonding scripts were unstable, and difficult to deliver
> > & update for various distros. So Stephen developed the new "transparent"
> > bonding mode, which greatly improves the situation.  
> 
> I specifically highlighted systemd-networkd as the change in the user
> space landscape.

Haiyang tried valiantly but getting every distro to do the right thing
with VF's bonding and hot plug was impossible to support.