2 files changed, 30 insertions, 2 deletions
diff --git a/tools/testing/selftests/kvm/aarch64/get-reg-list.c b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
index 709d7d721760..4abebde78187 100644
--- a/tools/testing/selftests/kvm/aarch64/get-reg-list.c
+++ b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
@@ -32,13 +32,13 @@ static struct feature_id_reg feat_id_regs[] = {
 	{
 		ARM64_SYS_REG(3, 0, 10, 2, 2),	/* PIRE0_EL1 */
 		ARM64_SYS_REG(3, 0, 0, 7, 3),	/* ID_AA64MMFR3_EL1 */
-		4,
+		8,
 		1
 	},
 	{
 		ARM64_SYS_REG(3, 0, 10, 2, 3),	/* PIR_EL1 */
 		ARM64_SYS_REG(3, 0, 0, 7, 3),	/* ID_AA64MMFR3_EL1 */
-		4,
+		8,
 		1
 	}
 };
diff --git a/tools/testing/selftests/kvm/x86_64/xapic_state_test.c b/tools/testing/selftests/kvm/x86_64/xapic_state_test.c
index 69849acd95b0..618cd2442390 100644
--- a/tools/testing/selftests/kvm/x86_64/xapic_state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xapic_state_test.c
@@ -184,6 +184,33 @@ static void test_apic_id(void)
 	kvm_vm_free(vm);
 }
 
+static void test_x2apic_id(void)
+{
+	struct kvm_lapic_state lapic = {};
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	int i;
+
+	vm = vm_create_with_one_vcpu(&vcpu, NULL);
+	vcpu_set_msr(vcpu, MSR_IA32_APICBASE, MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE);
+
+	/*
+	 * Try stuffing a modified x2APIC ID, KVM should ignore the value and
+	 * always return the vCPU's default/readonly x2APIC ID.
+	 */
+	for (i = 0; i <= 0xff; i++) {
+		*(u32 *)(lapic.regs + APIC_ID) = i << 24;
+		*(u32 *)(lapic.regs + APIC_SPIV) = APIC_SPIV_APIC_ENABLED;
+		vcpu_ioctl(vcpu, KVM_SET_LAPIC, &lapic);
+
+		vcpu_ioctl(vcpu, KVM_GET_LAPIC, &lapic);
+		TEST_ASSERT(*((u32 *)&lapic.regs[APIC_ID]) == vcpu->id << 24,
+			    "x2APIC ID should be fully readonly");
+	}
+
+	kvm_vm_free(vm);
+}
+
 int main(int argc, char *argv[])
 {
 	struct xapic_vcpu x = {
@@ -211,4 +238,5 @@ int main(int argc, char *argv[])
 	kvm_vm_free(vm);
 
 	test_apic_id();
+	test_x2apic_id();
 }