2015-01-30 10:19+0100, Paolo Bonzini: > On 29/01/2015 22:48, Radim Krčmář wrote: > > We want to support mixed modes and the easiest solution is to avoid > > optimizing those weird and unlikely scenarios. > > Hmm, what happens if use maxcpus to disable some CPUs at startup? Their APICs are kept sw-disabled in xAPIC mode. > Could > the disabled CPUs remain in xapic mode while the others move to x2apic? Yes, but it would only matter if the OS set LDR on them. I mark x2APIC with perfectly configured xAPIC on unused processors as "weird" ... (Linux 3.18 and 2.6.32 doesn't do it.) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
