KVM: arm64: selftests: Refactor debug-exceptions to make it amenable to new test cases

Split up the current test into a helper, but leave the debug version
checking in main(), to make it convenient to add a new debug exception
test case in a subsequent patch.
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220917010600.532642-4-reijiw@google.com

tools/testing/selftests/kvm/aarch64/debug-exceptions.c

@@ -246,7 +246,7 @@ static int debug_version(struct kvm_vcpu *vcpu)
 	return id_aa64dfr0 & 0xf;
 }
 
-int main(int argc, char *argv[])
+static void test_guest_debug_exceptions(void)
 {
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
@@ -259,9 +259,6 @@ int main(int argc, char *argv[])
 	vm_init_descriptor_tables(vm);
 	vcpu_init_descriptor_tables(vcpu);
 
-	__TEST_REQUIRE(debug_version(vcpu) >= 6,
-		       "Armv8 debug architecture not supported.");
-
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
 				ESR_EC_BRK_INS, guest_sw_bp_handler);
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
@@ -294,5 +291,18 @@ int main(int argc, char *argv[])
 
 done:
 	kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+	__TEST_REQUIRE(debug_version(vcpu) >= 6,
+		       "Armv8 debug architecture not supported.");
+	kvm_vm_free(vm);
+	test_guest_debug_exceptions();
+
 	return 0;
 }