selftests: KVM: Free the GIC FD when cleaning up in arch_timer

In order to correctly destroy a VM, all references to the VM must be
freed. The arch_timer selftest creates a VGIC for the guest, which
itself holds a reference to the VM.

Close the GIC FD when cleaning up a VM.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220406235615.1447180-4-oupton@google.com

tools/testing/selftests/kvm/aarch64/arch_timer.c

@@ -362,11 +362,12 @@ static void test_init_timer_irq(struct kvm_vm *vm)
 	pr_debug("ptimer_irq: %d; vtimer_irq: %d\n", ptimer_irq, vtimer_irq);
 }
 
+static int gic_fd;
+
 static struct kvm_vm *test_vm_create(void)
 {
 	struct kvm_vm *vm;
 	unsigned int i;
-	int ret;
 	int nr_vcpus = test_args.nr_vcpus;
 
 	vm = vm_create_default_with_vcpus(nr_vcpus, 0, 0, guest_code, NULL);
@@ -383,8 +384,8 @@ static struct kvm_vm *test_vm_create(void)
 
 	ucall_init(vm, NULL);
 	test_init_timer_irq(vm);
-	ret = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
-	if (ret < 0) {
+	gic_fd = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
+	if (gic_fd < 0) {
 		print_skip("Failed to create vgic-v3");
 		exit(KSFT_SKIP);
 	}
@@ -395,6 +396,12 @@ static struct kvm_vm *test_vm_create(void)
 	return vm;
 }
 
+static void test_vm_cleanup(struct kvm_vm *vm)
+{
+	close(gic_fd);
+	kvm_vm_free(vm);
+}
+
 static void test_print_help(char *name)
 {
 	pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n",
@@ -478,7 +485,7 @@ int main(int argc, char *argv[])
 
 	vm = test_vm_create();
 	test_run(vm);
-	kvm_vm_free(vm);
+	test_vm_cleanup(vm);
 
 	return 0;
 }