KVM: x86: fix x2apic logical address matching

We cannot hit the bug now, but future patches will expose this path.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 99c536597332..555956c3c473 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -599,7 +599,8 @@ static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda)
         logical_id = kvm_apic_get_reg(apic, APIC_LDR);
 
         if (apic_x2apic_mode(apic))
-                return (logical_id & mda) != 0;
+                return ((logical_id >> 16) == (mda >> 16))
+                       && (logical_id & mda & 0xffff) != 0;
 
         logical_id = GET_APIC_LOGICAL_ID(logical_id);