Subject: Re: [Qemu-ppc] [RFC PATCH 12/17] PowerPC: booke64: Add DO_KVM kernel hooks

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 12 Jul 2012 08:43:04 +1000

On Thu, 2012-07-12 at 00:35 +0200, Alexander Graf wrote:
> > On Thu, 2012-07-12 at 00:25 +0200, Alexander Graf wrote:
> >> Or just free up another register early on, like here.
> > 
> > If you're going to do that, you want to measure the impact on null
> > syscall performance though.
> 
> That should hold true for any change in that code, no?

Yes, but adding a gpr save is more invasive (you have to also load it
back later on & put it on the stack).

Cheers,
Ben.