Subject: Re: netfront for review

From: Rusty Russell <[email-masked]>
Date: Wed, 02 May 2007 14:23:02 +1000

On Wed, 2007-05-02 at 13:51 +1000, Herbert Xu wrote:
> On Wed, May 02, 2007 at 01:37:13PM +1000, Rusty Russell wrote:
> >
> > > +static int xennet_change_mtu(struct net_device *dev, int mtu)
> > > +{
> > > +	int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN;
> >
> > This seems odd to me: just because a device does TSO should we really
> > allow huge mtu settings?  Herbert?
> 
> Actually this has nothing to do with TSO/GSO.  This driver inherently
> supports arbitrary MTUs that's only limited by our network stack.  If
> the physical network device can't handle it you'll just get an ICMP
> error back or fragmentation.

Oops, I misread "xennet_can_sg" as a test for GSO.

Thanks for the clarification,
Rusty.