Subject: Re: [v1][KVM][PATCH 1/1] kvm:ppc:booehv: direct ISI exception to Guest

From: Scott Wood <[email-masked]>
Date: Fri, 10 May 2013 14:22:37 -0500

On 05/10/2013 12:57:33 PM, Alexander Graf wrote:
> Could you guys please collect performance data during the next weeks =20
> on both guest-directed ISIs as well as VF MMIOs (preferably with =20
> in-kernel MMIO), so that we can decide on the direction that's worth =20
> going towards?

Collecting data on VF MMIO would require implementing it (or at least =20
salvaging and fixing some old code), which is not a high priority at =20
the moment.  If we do implement VF in the future we could always undo =20
the direct ISI change, but it would still be nice to know if there's =20
any real benefit in the first place.

FWIW, I doubt that the "more stress on HW TLB" will be significant.

-Scott=