static int acrn_ioeventfd_assign()

in acrn/ioeventfd.c [76:145]

• 47 lines of code
• 11 McCabe index (conditional complexity)

static int acrn_ioeventfd_assign(struct acrn_vm *vm,
				 struct acrn_ioeventfd *args)
{
	struct eventfd_ctx *eventfd;
	struct hsm_ioeventfd *p;
	int ret;

	/* Check for range overflow */
	if (args->addr + args->len < args->addr)
		return -EINVAL;

	/*
	 * Currently, acrn_ioeventfd is used to support vhost. 1,2,4,8 width
	 * accesses can cover vhost's requirements.
	 */
	if (!(args->len == 1 || args->len == 2 ||
	      args->len == 4 || args->len == 8))
		return -EINVAL;

	eventfd = eventfd_ctx_fdget(args->fd);
	if (IS_ERR(eventfd))
		return PTR_ERR(eventfd);

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p) {
		ret = -ENOMEM;
		goto fail;
	}

	INIT_LIST_HEAD(&p->list);
	p->addr = args->addr;
	p->length = args->len;
	p->eventfd = eventfd;
	p->type = ioreq_type_from_flags(args->flags);

	/*
	 * ACRN_IOEVENTFD_FLAG_DATAMATCH flag is set in virtio 1.0 support, the
	 * writing of notification register of each virtqueue may trigger the
	 * notification. There is no data matching requirement.
	 */
	if (args->flags & ACRN_IOEVENTFD_FLAG_DATAMATCH)
		p->data = args->data;
	else
		p->wildcard = true;

	mutex_lock(&vm->ioeventfds_lock);

	if (hsm_ioeventfd_is_conflict(vm, p)) {
		ret = -EEXIST;
		goto unlock_fail;
	}

	/* register the I/O range into ioreq client */
	ret = acrn_ioreq_range_add(vm->ioeventfd_client, p->type,
				   p->addr, p->addr + p->length - 1);
	if (ret < 0)
		goto unlock_fail;

	list_add_tail(&p->list, &vm->ioeventfds);
	mutex_unlock(&vm->ioeventfds_lock);

	return 0;

unlock_fail:
	mutex_unlock(&vm->ioeventfds_lock);
	kfree(p);
fail:
	eventfd_ctx_put(eventfd);
	return ret;
}