2016-07-01 17:07+0200, Paolo Bonzini: > On 01/07/2016 16:54, Radim Krčmář wrote: >>> > (Hint: we >>> > want kvm-unit-tests for this). >> :) Something like this? >> >> 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.