Re: [PATCH] KVM: SVM: compile out AVIC if !CONFIG_X86_LOCAL_APIC

[Suravee Suthikulanit]

On 6/14/2016 5:01 PM, Paolo Bonzini wrote:
> On 14/06/2016 23:44, Suravee Suthikulanit wrote:
> > > On 6/14/2016 4:22 PM, Paolo Bonzini wrote:
> > > >> ----- Original Message -----
> > > > >>> From: "Suravee Suthikulanit" <suravee.suthikulpanit@xxxxxxx>
> > > > >>> To: "Paolo Bonzini" <pbonzini@xxxxxxxxxx>,
> > > > >>> linux-kernel@xxxxxxxxxxxxxxx, kvm@xxxxxxxxxxxxxxx
> > > > >>> Cc: rkrcmar@xxxxxxxxxx
> > > > >>> Sent: Tuesday, June 14, 2016 8:20:30 PM
> > > > >>> Subject: Re: [PATCH] KVM: SVM: compile out AVIC if
> > > > >>> !CONFIG_X86_LOCAL_APIC
> > > > >>>
> > > > >>> Hi Paolo,
> > > > >>>
> > > > >>> On 6/14/2016 11:40 AM, Paolo Bonzini wrote:
> > > > > >>>> AVIC needs __default_cpu_present_to_apicid.  Stub out all functions
> > > > > >>>> that use it, and disable the module parameter, if Linux is
> > > > > >>>> compiled without local APIC support.
> > > > >>>
> > > > >>> I think you are right that we should disable AVIC #ifndef
> > > > >>> CONFIG_X86_LOCAL_APIC. However, do you think we should just use
> > > > >>> default_cpu_present_to_apicid() instead of the
> > > > >>> __default_cpu_present_to_apicid()?
> > > >>
> > > >> I'm not sure why that would help?  default_cpu_present_to_apicid
> > > >> is also declared only if CONFIG_X86_LOCAL_APIC is defined.
> > >
> > > Actually, I also meant to include the change that I sent out
> > > (https://lkml.org/lkml/2016/6/13/898), which declares a dummy for the
> > > case #ifndef CONFIG_X86_LOCAL_APIC.  That should help with the issue here.
> I think it is by design that default_cpu_present_to_apicid() is absent.
>
> Perhaps you could create a kvm_cpu_get_apicid() function that is either
> __default_cpu_present_to_apicid() or WARN_ON_ONCE(1)+return 0?
>
> Paolo

Ok, I'll do that and send out V2.

Thanks,
Suravee