Re: Re: HVM network performance

[Andi Kleen <ak@suse.de>]

On Friday 05 May 2006 20:56, Andrew Theurer wrote:
> Andi Kleen wrote:
> > Steve Dobbelstein <steved@us.ibm.com> writes:
> >   
> >> I don't see any obvious problems in the Xenoprof output.  Anyone with
> >> experience with the inner workings of HVM domains care to comment on what
> >> might be causing the network performance to suffer so much?
> >>     
> >
> > You'll never get good throughput either from a NE2000 nor from a pcnet32
> > model.
> >   
> That was a suspicion of mine, but I wasn't sure.  I wonder if qemu-dm 
> could emulate another adapter (if so, which one would be best?) 

I looked some time ago at specs but all the promising adapters 
(widely used, good features, not too broken design) had very restrictive
license terms on their specifications (if they were available) 

They tended to only allow
using the specification to write drivers for the hardware.

> or do we  
> just punt and go for para-virt drivers.

That's the easy and probably fastest way short term, but long term 
it's a lot more work (you will need to write drivers for all the old and new guest OS
you want to run to get good performance) 

Also it's a logistical problem because you'll need to distribute and setup
all these drivers even if they are written.

-Andi