KVM: selftests: Convert get-reg-list away from its "VCPU_ID"

Track the vCPU's 'struct kvm_vcpu' object in get-reg-list instead of
hardcoding '0' everywhere.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/aarch64/get-reg-list.c

@@ -411,6 +411,7 @@ static void run_test(struct vcpu_config *c)
 	struct kvm_vcpu_init init = { .target = -1, };
 	int new_regs = 0, missing_regs = 0, i, n;
 	int failed_get = 0, failed_set = 0, failed_reject = 0;
+	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	struct reg_sublist *s;
 
@@ -418,11 +419,11 @@ static void run_test(struct vcpu_config *c)
 
 	vm = vm_create_barebones();
 	prepare_vcpu_init(c, &init);
-	__vm_vcpu_add(vm, 0);
-	aarch64_vcpu_setup(vm, 0, &init);
-	finalize_vcpu(vm, 0, c);
+	vcpu = __vm_vcpu_add(vm, 0);
+	aarch64_vcpu_setup(vm, vcpu->id, &init);
+	finalize_vcpu(vm, vcpu->id, c);
 
-	reg_list = vcpu_get_reg_list(vm, 0);
+	reg_list = vcpu_get_reg_list(vm, vcpu->id);
 
 	if (fixup_core_regs)
 		core_reg_fixup();
@@ -458,7 +459,7 @@ static void run_test(struct vcpu_config *c)
 		bool reject_reg = false;
 		int ret;
 
-		ret = __vcpu_get_reg(vm, 0, reg_list->reg[i], &addr);
+		ret = __vcpu_get_reg(vm, vcpu->id, reg_list->reg[i], &addr);
 		if (ret) {
 			printf("%s: Failed to get ", config_name(c));
 			print_reg(c, reg.id);
@@ -470,7 +471,7 @@ static void run_test(struct vcpu_config *c)
 		for_each_sublist(c, s) {
 			if (s->rejects_set && find_reg(s->rejects_set, s->rejects_set_n, reg.id)) {
 				reject_reg = true;
-				ret = __vcpu_ioctl(vm, 0, KVM_SET_ONE_REG, &reg);
+				ret = __vcpu_ioctl(vm, vcpu->id, KVM_SET_ONE_REG, &reg);
 				if (ret != -1 || errno != EPERM) {
 					printf("%s: Failed to reject (ret=%d, errno=%d) ", config_name(c), ret, errno);
 					print_reg(c, reg.id);
@@ -482,7 +483,7 @@ static void run_test(struct vcpu_config *c)
 		}
 
 		if (!reject_reg) {
-			ret = __vcpu_ioctl(vm, 0, KVM_SET_ONE_REG, &reg);
+			ret = __vcpu_ioctl(vm, vcpu->id, KVM_SET_ONE_REG, &reg);
 			if (ret) {
 				printf("%s: Failed to set ", config_name(c));
 				print_reg(c, reg.id);