[Qemu-devel] Re: [PATCH 1/1] qemu-kvm: virtio-net: Re-instate GSO code removed upstream

[Mark McLoughlin]

On Wed, 2009-09-30 at 15:55 +0200, Avi Kivity wrote:
> On 09/30/2009 03:51 PM, Christoph Hellwig wrote:
> > I might sound like a broken record, but why isn't the full GSO support
> > for virtio-net upstream in qemu?
> >    
> 
> IIRC the current hacks are not upstream quality.
> 
> The problem (again IIRC) is that the guest and host negotiate a 
> protocol, but the qemu vlan model doesn't have a guest and a host, it 
> has peers (possibly more than two), so a lot of translation has to take 
> place if you have one peer supporting a guest feature and another not.

Right.

> IMO the best way out is to drop the vlan model.  It has its uses, but 
> they can all be implemented in other ways, and are all have minor usage 
> compared to the business of getting data into and out of a guest.

I think we should keep the vlan stuff, just de-emphasise it.

I'm planning on adding -hostnet and -nic arguments, which would not use
vlans by default but rather connect the nic directly to the host side.

The QemuOpts conversion of -net which is waiting to be merged is the
first stage of that.

Cheers,
Mark.