Re: [PATCH] Add I/O hypercalls for i386 paravirt

Rusty Russell
2007-08-22T06:26:44Z

On Wed, 2007-08-22 at 08:34 +0300, Avi Kivity wrote:
> Zachary Amsden wrote:
> > This patch provides hypercalls for the i386 port I/O instructions,
> > which vastly helps guests which use native-style drivers. For certain
> > VMI workloads, this provides a performance boost of up to 30%. We
> > expect KVM and lguest to be able to achieve similar gains on I/O
> > intensive workloads.
>
> Won't these workloads be better off using paravirtualized drivers?
> i.e., do the native drivers with paravirt I/O instructions get anywhere
> near the performance of paravirt drivers?

This patch also means I can kill off the emulation code in
drivers/lguest/core.c, which is a real relief.

Cheers,
Rusty.