KVM: x86: reset APIC ID when enabling LAPIC

APIC ID should be set to the initial APIC ID when enabling LAPIC.
This only matters if the guest changes APIC ID.  No sane OS does that.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 41089dbeeafcb0a853f21b4b6ca06b143f217024..0fce77fdbe91e879b645dc96dad002fa0f08f67b 100644 (file)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1720,9 +1720,10 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 
        /* update jump label if enable bit changes */
        if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) {
-               if (value & MSR_IA32_APICBASE_ENABLE)
+               if (value & MSR_IA32_APICBASE_ENABLE) {
+                       kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
                        static_key_slow_dec_deferred(&apic_hw_disabled);
-               else
+               } else
                        static_key_slow_inc(&apic_hw_disabled.key);
                recalculate_apic_map(vcpu->kvm);
        }