[PATCH 8/8] KVM: selftests: vmx_apic_access_test: Check APIC virtualization support

[Ewan Hai-oc]

From: Frank Zhu <frankzhu@xxxxxxxxxxx>

Not all CPUs that support VMX necessarily support the "virtualize APIC
accesses" secondary processor-based VM-execution control. For example,
some Zhaoxin CPUs lack this feature. Add a capability check before
running the test to properly skip on unsupported hardware instead of
failing.

Add kvm_cpu_has_vmx_apic_access_virt() helper to vmx.c, following the
same pattern as kvm_cpu_has_ept().

Signed-off-by: Frank Zhu <frankzhu@xxxxxxxxxxx>
Signed-off-by: Ewan Hai <ewanhai-oc@xxxxxxxxxxx>
---
 tools/testing/selftests/kvm/include/x86/vmx.h     |  1 +
 tools/testing/selftests/kvm/lib/x86/vmx.c         | 15 +++++++++++++++
 .../selftests/kvm/x86/vmx_apic_access_test.c      |  1 +
 3 files changed, 17 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86/vmx.h b/tools/testing/selftests/kvm/include/x86/vmx.h
index 4bcfd60e3aec..d9e3bbd56040 100644
--- a/tools/testing/selftests/kvm/include/x86/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86/vmx.h
@@ -560,6 +560,7 @@ bool load_vmcs(struct vmx_pages *vmx);
 bool ept_1g_pages_supported(void);
 
 bool kvm_cpu_has_ept(void);
+bool kvm_cpu_has_vmx_apic_access_virt(void);
 void vm_enable_ept(struct kvm_vm *vm);
 void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm);
 
diff --git a/tools/testing/selftests/kvm/lib/x86/vmx.c b/tools/testing/selftests/kvm/lib/x86/vmx.c
index cd09c9de4485..d634a0f00166 100644
--- a/tools/testing/selftests/kvm/lib/x86/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86/vmx.c
@@ -390,6 +390,21 @@ bool kvm_cpu_has_ept(void)
 	return ctrl & SECONDARY_EXEC_ENABLE_EPT;
 }
 
+bool kvm_cpu_has_vmx_apic_access_virt(void)
+{
+	u64 ctrl;
+
+	if (!kvm_cpu_has(X86_FEATURE_VMX))
+		return false;
+
+	ctrl = kvm_get_feature_msr(MSR_IA32_VMX_TRUE_PROCBASED_CTLS) >> 32;
+	if (!(ctrl & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))
+		return false;
+
+	ctrl = kvm_get_feature_msr(MSR_IA32_VMX_PROCBASED_CTLS2) >> 32;
+	return ctrl & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
+}
+
 void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm)
 {
 	vmx->apic_access = (void *)vm_alloc_page(vm);
diff --git a/tools/testing/selftests/kvm/x86/vmx_apic_access_test.c b/tools/testing/selftests/kvm/x86/vmx_apic_access_test.c
index 463f73aa9159..a1b6da4c0740 100644
--- a/tools/testing/selftests/kvm/x86/vmx_apic_access_test.c
+++ b/tools/testing/selftests/kvm/x86/vmx_apic_access_test.c
@@ -78,6 +78,7 @@ int main(int argc, char *argv[])
 	struct kvm_vm *vm;
 
 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
+	TEST_REQUIRE(kvm_cpu_has_vmx_apic_access_virt());
 
 	vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
 
-- 
2.34.1