diff options
Diffstat (limited to 'arch/x86/kvm/lapic.c')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 50354c7a2dc1..9d4f73c4dc02 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -826,17 +826,17 @@ static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda) if (kvm_apic_broadcast(apic, mda)) return true; - if (apic_x2apic_mode(apic)) - return mda == kvm_x2apic_id(apic); - /* - * Hotplug hack: Make LAPIC in xAPIC mode also accept interrupts as if - * it were in x2APIC mode. Hotplugged VCPUs start in xAPIC mode and - * this allows unique addressing of VCPUs with APIC ID over 0xff. - * The 0xff condition is needed because writeable xAPIC ID. + * Hotplug hack: Accept interrupts for vCPUs in xAPIC mode as if they + * were in x2APIC mode if the target APIC ID can't be encoded as an + * xAPIC ID. This allows unique addressing of hotplugged vCPUs (which + * start in xAPIC mode) with an APIC ID that is unaddressable in xAPIC + * mode. Match the x2APIC ID if and only if the target APIC ID can't + * be encoded in xAPIC to avoid spurious matches against a vCPU that + * changed its (addressable) xAPIC ID (which is writable). */ - if (kvm_x2apic_id(apic) > 0xff && mda == kvm_x2apic_id(apic)) - return true; + if (apic_x2apic_mode(apic) || mda > 0xff) + return mda == kvm_x2apic_id(apic); return mda == kvm_xapic_id(apic); } |