RE: [Xen-users] Slow windows network with gplpv driver.

["James Harper" <james.harper@xxxxxxxxxxxxxxxx>]

> >
> > The point of the offloading in DomU is that no checksum generation
is
> > necessary, so the checksums will always be invalid while the packets
> > exist on the bridge. If the packet is sent to another DomU that
supports
> > checksum offload then Dom0 will leave the checksum invalid and pass
a
> > flag with the packet to say that the packet is checked and so
looking at
> > the checksum is unnecessary. If the packet is sent to a DomU that
> > doesn't support offload then Dom0 will just calculate the checksum.
If
> > the packet hits a physical network adapter then the hardware will
> > calculate the checksum or if the hardware doesn't support it then
Dom0
> > will calculate it.
> 
> Right, understood, but I tend to see bad checksums on packets when
they
> reach the destination (or are on the wire, via a Network TAP), and not
> just on the local bridge.
> 

I guess the important distinction then is do you see the same problems
with Linux DomU's with checksum offload too, or is it just GPLPV? If
it's just GPLPV then obviously the problem is mine :)

James

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