Re: [Qemu-devel] [PATCH v2 0/2] kvm: x86 CPU power management

[Eduardo Habkost]

On Thu, Jun 14, 2018 at 05:40:41PM +0200, Paolo Bonzini wrote:
> On 14/06/2018 10:18, Daniel P. Berrangé wrote:
> > I don't think
> > the -realtime flag should ever have been introduced, and we certainly
> > shouldn't add more stuff under it.
> > 
> > "-realtime" is referring to a very specific use case, while the
> > properties listed under it are all general purpose features. Real
> > time guests just happen to be one possible use case, but it is
> > valid to use them for non-real time guests.
> > 
> > IOW, I think we should just have this as an option under -cpu or
> > some other *functionally* named option, not a option named after
> > a specific usage scenario.
> 
> "-cpu" is certainly wrong for KVM_CAP_X86_DISABLE_EXITS. "-cpu" is a
> device option, while this is about host behavior.  "-realtime"'s name is
> awful, but I still think it's the best place for this option.  Maybe we
> could call it "-realtime power-mgmt={host|guest}".
> 
> A separate issue is whether the same flag should control both
> KVM_CAP_X86_DISABLE_EXITS and the monitor/mwait CPUID leaf.  Eduardo,
> what do you think?

Making "-cpu host" be affected by a host-side option is
acceptable to me.  A "-cpu" option would be more appropriate if
we decide to allow monitor/mwait be enabled for other CPU models
too.

-- 
Eduardo