Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for APIC ID register

[Paolo Bonzini]

On 01/07/2016 17:53, Radim KrÄmÃÅ wrote:
>> >>   enable_xapic()
>> >>   id = apic_id()
>> >>   set_apic_id(id+1) // ?
>> >>   enable_x2apic()
>> >>   id == apic_id() & 0xff
>> >>   disable_apic()
>> >>   enable_xapic()
>> >>   id == apic_id()
>> >> 
> > 
> > Yes, plus checking that it "moves" appropriately between low and high bits.
> 
> x2APIC cannot use MMIO interface, so apic_id() already does the best we
> can ... if KVM is shifting wrong somwhere, then the id should differ.

Yeah, fair enough.

Paolo