selftests: kvm: consolidate VMX support checks

vmx_* tests require VMX and three of them implement the same check. Move it
to vmx library.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/include/x86_64/vmx.h

@@ -580,6 +580,8 @@ bool prepare_for_vmx_operation(struct vmx_pages *vmx);
 void prepare_vmcs(struct vmx_pages *vmx, void *guest_rip, void *guest_rsp);
 bool load_vmcs(struct vmx_pages *vmx);
 
+void nested_vmx_check_supported(void);
+
 void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm,
 		   uint64_t nested_paddr, uint64_t paddr, uint32_t eptp_memslot);
 void nested_map(struct vmx_pages *vmx, struct kvm_vm *vm,

tools/testing/selftests/kvm/lib/x86_64/vmx.c

@@ -376,6 +376,16 @@ void prepare_vmcs(struct vmx_pages *vmx, void *guest_rip, void *guest_rsp)
 	init_vmcs_guest_state(guest_rip, guest_rsp);
 }
 
+void nested_vmx_check_supported(void)
+{
+	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
+
+	if (!(entry->ecx & CPUID_VMX)) {
+		fprintf(stderr, "nested VMX not enabled, skipping test\n");
+		exit(KSFT_SKIP);
+	}
+}
+
 void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm,
 	 	   uint64_t nested_paddr, uint64_t paddr, uint32_t eptp_memslot)
 {

tools/testing/selftests/kvm/x86_64/vmx_close_while_nested_test.c

@@ -53,12 +53,8 @@ static void l1_guest_code(struct vmx_pages *vmx_pages)
 int main(int argc, char *argv[])
 {
 	vm_vaddr_t vmx_pages_gva;
-	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
 
-	if (!(entry->ecx & CPUID_VMX)) {
-		fprintf(stderr, "nested VMX not enabled, skipping test\n");
-		exit(KSFT_SKIP);
-	}
+	nested_vmx_check_supported();
 
 	vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code);
 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());

tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c

@@ -224,7 +224,6 @@ int main(int argc, char *argv[])
 {
 	struct kvm_vm *vm;
 	struct kvm_nested_state state;
-	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
 
 	have_evmcs = kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS);
 
@@ -237,10 +236,7 @@ int main(int argc, char *argv[])
 	 * AMD currently does not implement set_nested_state, so for now we
 	 * just early out.
 	 */
-	if (!(entry->ecx & CPUID_VMX)) {
-		fprintf(stderr, "nested VMX not enabled, skipping test\n");
-		exit(KSFT_SKIP);
-	}
+	nested_vmx_check_supported();
 
 	vm = vm_create_default(VCPU_ID, 0, 0);
 

tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c

@@ -128,12 +128,8 @@ static void report(int64_t val)
 int main(int argc, char *argv[])
 {
 	vm_vaddr_t vmx_pages_gva;
-	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
 
-	if (!(entry->ecx & CPUID_VMX)) {
-		fprintf(stderr, "nested VMX not enabled, skipping test\n");
-		exit(KSFT_SKIP);
-	}
+	nested_vmx_check_supported();
 
 	vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code);
 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());