diff --git a/tools/testing/selftests/kvm/irq_test.c b/tools/testing/selftests/kvm/irq_test.c
index d2c745c54960..240f6f0fdbe4 100644
--- a/tools/testing/selftests/kvm/irq_test.c
+++ b/tools/testing/selftests/kvm/irq_test.c
@@ -18,6 +18,7 @@ static u64 timeout_ns = 2ULL * 1000 * 1000 * 1000;
 static bool guest_ready_for_irqs[KVM_MAX_VCPUS];
 static bool guest_received_irq[KVM_MAX_VCPUS];
 static bool guest_received_nmi[KVM_MAX_VCPUS];
+static bool x2apic = true;
 static bool irq_affinity;
 static bool done;
 
@@ -31,14 +32,20 @@ static bool done;
 
 static u32 guest_get_vcpu_id(void)
 {
-	return x2apic_read_reg(APIC_ID);
+	if (x2apic)
+		return x2apic_read_reg(APIC_ID);
+	else
+		return xapic_read_reg(APIC_ID) >> 24;
 }
 
 static void guest_irq_handler(struct ex_regs *regs)
 {
 	WRITE_ONCE(guest_received_irq[guest_get_vcpu_id()], true);
 
-	x2apic_write_reg(APIC_EOI, 0);
+	if (x2apic)
+		x2apic_write_reg(APIC_EOI, 0);
+	else
+		xapic_write_reg(APIC_EOI, 0);
 }
 
 static void guest_nmi_handler(struct ex_regs *regs)
@@ -48,7 +55,10 @@ static void guest_nmi_handler(struct ex_regs *regs)
 
 static void guest_code(void)
 {
-	x2apic_enable();
+	if (x2apic)
+		x2apic_enable();
+	else
+		xapic_enable();
 
 	sti_nop();
 
@@ -158,7 +168,7 @@ static const char *probe_iommu_type(void)
 
 static void help(const char *name)
 {
-	printf("Usage: %s [-a] [-d <segment:bus:device.function>] [-e] [-h] [-i nr_irqs] [-m] [-n] [-t iommu_type] [-v nr_vcpus]\n", name);
+	printf("Usage: %s [-a] [-d <segment:bus:device.function>] [-e] [-h] [-i nr_irqs] [-m] [-n] [-t iommu_type] [-v nr_vcpus] [-x]\n", name);
 	printf("\n");
 	printf("Tests KVM interrupt routing and delivery via irqfd.\n");
 	printf("-a	Affine the device's host IRQ to a random physical CPU\n");
@@ -169,6 +179,7 @@ static void help(const char *name)
 	printf("-n	Deliver 50 percent of IRQs as non-maskable interrupts\n");
 	printf("-t	Override the IOMMU type to use (vfio_type1_iommu or iommufd)\n");
 	printf("-v	Number of vCPUS to run\n");
+	printf("-x	Use xAPIC mode instead of x2APIC mode in the guest\n");
 	printf("\n");
 	exit(KSFT_FAIL);
 }
@@ -205,7 +216,7 @@ int main(int argc, char **argv)
 	struct kvm_vm *vm;
 	int irq, irq_cpu;
 
-	while ((c = getopt(argc, argv, "ad:ehi:mnt:v:")) != -1) {
+	while ((c = getopt(argc, argv, "ad:ehi:mnt:v:x")) != -1) {
 		switch (c) {
 		case 'a':
 			irq_affinity = true;
@@ -233,6 +244,9 @@ int main(int argc, char **argv)
 			TEST_ASSERT(nr_vcpus <= KVM_MAX_VCPUS,
 				    "KVM selftests support at most %u vCPUs", KVM_MAX_VCPUS);
 			break;
+		case 'x':
+			x2apic = false;
+			break;
 		case 'h':
 		default:
 			help(argv[0]);
@@ -248,6 +262,11 @@ int main(int argc, char **argv)
 	vm_install_exception_handler(vm, vector, guest_irq_handler);
 	vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler);
 
+	if (!x2apic) {
+		TEST_ASSERT(nr_vcpus < 256, "xAPIC can only target IDs [0-254] (255 vCPUs)");
+		virt_pg_map(vm, APIC_DEFAULT_GPA, APIC_DEFAULT_GPA);
+	}
+
 	if (device_bdf) {
 		if (!iommu_type)
 			iommu_type = probe_iommu_type();
@@ -271,6 +290,8 @@ int main(int argc, char **argv)
 
 	kvm_assign_irqfd(vm, gsi, eventfd);
 
+	sync_global_to_guest(vm, x2apic);
+
 	if (migrate_vcpus)
 		kvm_sched_getaffinity(0, sizeof(available_cpus), &available_cpus);