Commit facb07cd authored by Igor Mammedov's avatar Igor Mammedov Committed by Eduardo Habkost
Browse files

pc: apic_common: Reset APIC ID to initial ID when switching into x2APIC mode 



SDM: x2APIC State Transitions:
         State Changes From xAPIC Mode to x2APIC Mode
"
Any APIC ID value written to the memory-mapped
local APIC ID register is not preserved
"

Signed-off-by: default avatarIgor Mammedov <imammedo@redhat.com>
Reviewed-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Reviewed-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent 4c34897a

hw/intc/apic_common.c

+5 −0
Original line number Diff line number Diff line
@@ -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);

    }

}