[PATCH v4 5/6] KVM: selftests: Refactor invalid nVMX state test to prepare for RSM testcase

[Sean Christopherson <seanjc@google.com>]

In the invalid nVMX guest state test, extract the creation of the VM and
initial running of the vCPU to get to L2 into helpers so that the common
code can be reused to extend the test to also cover RSM.

Eliminate the unnecessary global "vm", and opportunistically free the VM
after the testcase as there's zero reason not to.

Opportunistically assert that L2 is never resumed after the I/O exit to L1,
e.g. to guard against false passes.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../kvm/x86/vmx_invalid_nested_guest_state.c  | 61 +++++++++++++------
 1 file changed, 42 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86/vmx_invalid_nested_guest_state.c b/tools/testing/selftests/kvm/x86/vmx_invalid_nested_guest_state.c
index fb9444ca0d7e..ab00265d6c94 100644
--- a/tools/testing/selftests/kvm/x86/vmx_invalid_nested_guest_state.c
+++ b/tools/testing/selftests/kvm/x86/vmx_invalid_nested_guest_state.c
@@ -11,8 +11,6 @@
 
 #define ARBITRARY_IO_PORT 0x80
 
-static struct kvm_vm *vm;
-
 static void l2_guest_code(void)
 {
 	/*
@@ -21,6 +19,7 @@ static void l2_guest_code(void)
 	 */
 	asm volatile("inb $" __stringify(ARBITRARY_IO_PORT) ", %%al"
 		     ::: "rax");
+	GUEST_FAIL("L2 resumed after stuffing invalid guest state");
 }
 
 static void l1_guest_code(struct vmx_pages *vmx_pages)
@@ -46,35 +45,50 @@ static void l1_guest_code(struct vmx_pages *vmx_pages)
 	GUEST_DONE();
 }
 
-int main(int argc, char *argv[])
+static void vcpu_run_to_io(struct kvm_vcpu *vcpu, bool want_l2)
+{
+	struct kvm_run *run = vcpu->run;
+
+	vcpu_run(vcpu);
+
+	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
+
+	TEST_ASSERT(run->io.port == ARBITRARY_IO_PORT &&
+		    (!!(run->flags & KVM_RUN_X86_GUEST_MODE) == want_l2  ||
+		     !kvm_has_cap(KVM_CAP_X86_GUEST_MODE)),
+		    "Expected IN from port %d from L2, got port %d from L%u",
+		    ARBITRARY_IO_PORT, run->io.port,
+		    1 + !!(run->flags & KVM_RUN_X86_GUEST_MODE));
+}
+
+static struct kvm_vm *vm_create_and_run_l2(struct kvm_vcpu **vcpu)
 {
 	gva_t vmx_pages_gva;
-	struct kvm_sregs sregs;
-	struct kvm_vcpu *vcpu;
-	struct kvm_run *run;
-	struct ucall uc;
+	struct kvm_vm *vm;
 
-	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
-
-	vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
+	vm = vm_create_with_one_vcpu(vcpu, l1_guest_code);
 
 	/* Allocate VMX pages and shared descriptors (vmx_pages). */
 	vcpu_alloc_vmx(vm, &vmx_pages_gva);
-	vcpu_args_set(vcpu, 1, vmx_pages_gva);
-
-	vcpu_run(vcpu);
-
-	run = vcpu->run;
+	vcpu_args_set(*vcpu, 1, vmx_pages_gva);
 
 	/*
 	 * The first exit to L0 userspace should be an I/O access from L2.
 	 * Running L1 should launch L2 without triggering an exit to userspace.
 	 */
-	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
+	vcpu_run_to_io(*vcpu, true);
 
-	TEST_ASSERT(run->io.port == ARBITRARY_IO_PORT,
-		    "Expected IN from port %d from L2, got port %d",
-		    ARBITRARY_IO_PORT, run->io.port);
+	return vm;
+}
+
+static void test_invalid_l2_guest_state(void)
+{
+	struct kvm_sregs sregs;
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	struct ucall uc;
+
+	vm = vm_create_and_run_l2(&vcpu);
 
 	/*
 	 * Stuff invalid guest state for L2 by making TR unusable.  The next
@@ -96,4 +110,13 @@ int main(int argc, char *argv[])
 	default:
 		TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
 	}
+
+	kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
+
+	test_invalid_l2_guest_state();
 }
-- 
2.55.0.229.g6434b31f56-goog