KVM: selftests: Extend nested x2APIC test to validate disabling x2APIC virt

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260813223610.2043560-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 68 insertions, 20 deletions

diff --git a/tools/testing/selftests/kvm/x86/nested_x2apic_test.c b/tools/testing/selftests/kvm/x86/nested_x2apic_test.c
index 3b59ba3e3342..964937aefe39 100644
--- a/tools/testing/selftests/kvm/x86/nested_x2apic_test.c
+++ b/tools/testing/selftests/kvm/x86/nested_x2apic_test.c
@@ -29,10 +29,12 @@ static void l2_guest_code(void)
 	if (inhibit_apicv)
 		wrmsr(MSR_IA32_APICBASE, rdmsr(MSR_IA32_APICBASE) & GENMASK_ULL(11, 0));
 
-	x2apic_write_reg(APIC_TASKPRI, 0xf0);
-	GUEST_ASSERT_EQ(x2apic_read_reg(APIC_TASKPRI), 0xf0);
+	for (;;) {
+		x2apic_write_reg(APIC_TASKPRI, 0xf0);
+		GUEST_ASSERT_EQ(x2apic_read_reg(APIC_TASKPRI), 0xf0);
 
-	asm volatile("cpuid" ::: "eax", "ebx", "ecx", "edx");
+		asm volatile("cpuid" ::: "eax", "ebx", "ecx", "edx");
+	}
 }
 
 static void l1_svm_code(struct svm_test_data *svm)
@@ -46,6 +48,7 @@ static void l1_svm_code(struct svm_test_data *svm)
 	GUEST_ASSERT_EQ(ctrl->exit_code, SVM_EXIT_CPUID);
 
 	stgi();
+	x2apic_write_reg(APIC_TASKPRI, 0);
 }
 
 static void l1_vmx_code(struct vmx_pages *vmx)
@@ -58,22 +61,50 @@ static void l1_vmx_code(struct vmx_pages *vmx)
 	prepare_vmcs(vmx, NULL);
 	GUEST_ASSERT_EQ(vmwrite(GUEST_RIP, (unsigned long)l2_guest_code), 0);
 
+	control = vmreadz(PIN_BASED_VM_EXEC_CONTROL);
+	control |= PIN_BASED_EXT_INTR_MASK;
+	vmwrite(PIN_BASED_VM_EXEC_CONTROL, control);
+
 	control = vmreadz(CPU_BASED_VM_EXEC_CONTROL);
-	control |= CPU_BASED_USE_MSR_BITMAPS;
+	control |= CPU_BASED_USE_MSR_BITMAPS | CPU_BASED_TPR_SHADOW;
 	GUEST_ASSERT_EQ(vmwrite(CPU_BASED_VM_EXEC_CONTROL, control), 0);
 
+	control = vmreadz(SECONDARY_VM_EXEC_CONTROL);
+	control |= SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
+		   SECONDARY_EXEC_APIC_REGISTER_VIRT |
+		   SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY;
+	control &= (rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2) >> 32);
+	GUEST_ASSERT_EQ(vmwrite(SECONDARY_VM_EXEC_CONTROL, control), 0);
+
 	GUEST_ASSERT(!vmlaunch());
 	GUEST_ASSERT_EQ(vmreadz(VM_EXIT_REASON), EXIT_REASON_CPUID);
+	GUEST_ASSERT_EQ(vmwrite(GUEST_RIP,
+			vmreadz(GUEST_RIP) + vmreadz(VM_EXIT_INSTRUCTION_LEN)), 0);
 }
 
-static void l1_guest_code(void *test_data)
+static void l1_vmx_code_part2(void)
 {
-	x2apic_enable();
+	u64 control;
 
-	if (this_cpu_has(X86_FEATURE_SVM))
-		l1_svm_code(test_data);
-	else
-		l1_vmx_code(test_data);
+	control = vmreadz(CPU_BASED_VM_EXEC_CONTROL);
+	control &= ~CPU_BASED_TPR_SHADOW;
+	GUEST_ASSERT_EQ(vmwrite(CPU_BASED_VM_EXEC_CONTROL, control), 0);
+
+	control = vmreadz(SECONDARY_VM_EXEC_CONTROL);
+	control &= ~(SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
+			SECONDARY_EXEC_APIC_REGISTER_VIRT |
+			SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
+	GUEST_ASSERT_EQ(vmwrite(SECONDARY_VM_EXEC_CONTROL, control), 0);
+
+	GUEST_ASSERT(!vmresume());
+	GUEST_ASSERT_EQ(vmreadz(VM_EXIT_REASON), EXIT_REASON_CPUID);
+	GUEST_ASSERT_EQ(vmwrite(GUEST_RIP,
+			vmreadz(GUEST_RIP) + vmreadz(VM_EXIT_INSTRUCTION_LEN)), 0);
+}
+
+static void l1_test_x2apic_intercepts(void)
+{
+	GUEST_ASSERT_EQ(nr_irqs, 0);
 
 	sti_nop();
 
@@ -93,16 +124,40 @@ static void l1_guest_code(void *test_data)
 	x2apic_write_reg(APIC_ICR, APIC_DEST_SELF | APIC_INT_ASSERT | POSTED_INTR_NESTED_VECTOR);
 	GUEST_ASSERT_EQ(nr_irqs, 3);
 
+	nr_irqs = 0;
+}
+
+static void l1_guest_code(void *test_data)
+{
+	x2apic_enable();
+
+	if (this_cpu_has(X86_FEATURE_SVM))
+		l1_svm_code(test_data);
+	else
+		l1_vmx_code(test_data);
+
+	GUEST_ASSERT_EQ(x2apic_read_reg(APIC_TASKPRI), 0);
+	x2apic_write_reg(APIC_TASKPRI, 0xf0);
+
+	l1_test_x2apic_intercepts();
+
+	if (this_cpu_has(X86_FEATURE_VMX)) {
+		l1_vmx_code_part2();
+		l1_test_x2apic_intercepts();
+	}
+
 	GUEST_DONE();
 }
 
-static void __test_x2apic_intercepts(void)
+static void __test_x2apic_intercepts(bool with_inhibit_apicv)
 {
 	gva_t nested_test_data_gva;
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	struct ucall uc;
 
+	inhibit_apicv = with_inhibit_apicv;
+
 	vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
 	vm_install_exception_handler(vm, POSTED_INTR_VECTOR, guest_irq_handler);
 	vm_install_exception_handler(vm, POSTED_INTR_WAKEUP_VECTOR, guest_irq_handler);
@@ -134,17 +189,10 @@ static void __test_x2apic_intercepts(void)
 	kvm_vm_free(vm);
 }
 
-#define test_x2apic_intercepts(inhibit_apic_setting)	\
-do {							\
-	inhibit_apic_setting;				\
-							\
-	__test_x2apic_intercepts();			\
-} while (0)
-
 int main(int argc, char *argv[])
 {
 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM) || kvm_cpu_has(X86_FEATURE_VMX));
 
-	test_x2apic_intercepts(inhibit_apicv = true);
-	test_x2apic_intercepts(inhibit_apicv = false);
+	test_x2apic_intercepts(true);
+	test_x2apic_intercepts(false);
 }