Re: [PATCH] KVM: PPC: Book3S HV: Remove vcpu->arch.dec usage

From: Paul Mackerras
Date: Thu Jan 11 2018 - 05:02:16 EST


On Tue, Dec 19, 2017 at 03:56:24PM +0100, Alexander Graf wrote:
> On Book3S in HV mode, we don't use the vcpu->arch.dec field at all.
> Instead, all logic is built around vcpu->arch.dec_expires.
>
> So let's remove the one remaining piece of code that was setting it.
>
> Signed-off-by: Alexander Graf <agraf@xxxxxxx>

Thanks, applied to my kvm-ppc-next branch.

> Looking through the DEC logic, I fail to see any code that allows
> save or restore of DEC. Do we maybe miss out on that register for
> (live) migration?

Yes, it looks like we do. I'm amazed no-one has noticed before. I'll
fix it.

Paul.