diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c index ea3c8caef5..d78c885509 100644 --- a/hw/intc/apic_common.c +++ b/hw/intc/apic_common.c @@ -40,6 +40,11 @@ void cpu_set_apic_base(DeviceState *dev, uint64_t val) if (dev) { APICCommonState *s = APIC_COMMON(dev); APICCommonClass *info = APIC_COMMON_GET_CLASS(s); + /* switching to x2APIC, reset possibly modified xAPIC ID */ + if (!(s->apicbase & MSR_IA32_APICBASE_EXTD) && + (val & MSR_IA32_APICBASE_EXTD)) { + s->id = s->initial_apic_id; + } info->set_base(s, val); } }