[PATCH v6 07/14] iommufd/viommu: Add iommufd_viommu_report_event helper

[Jason Gunthorpe]

On Fri, Jan 24, 2025 at 04:30:36PM -0800, Nicolin Chen wrote:
> +int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
> +				enum iommu_veventq_type type, void *event_data,
> +				size_t data_len)
> +{
> +	struct iommufd_veventq *veventq;
> +	struct iommufd_vevent *vevent;
> +	int rc = 0;
> +
> +	if (WARN_ON_ONCE(!data_len || !event_data))
> +		return -EINVAL;
> +
> +	down_read(&viommu->veventqs_rwsem);
> +
> +	veventq = iommufd_viommu_find_veventq(viommu, type);
> +	if (!veventq) {
> +		rc = -EOPNOTSUPP;
> +		goto out_unlock_veventqs;
> +	}
> +
> +	if (atomic_read(&veventq->num_events) == veventq->depth) {
> +		vevent = &veventq->overflow;
> +		goto out_set_header;
> +	}
> +
> +	vevent = kmalloc(struct_size(vevent, event_data, data_len), GFP_KERNEL);
> +	if (!vevent) {
> +		rc = -ENOMEM;
> +		goto out_unlock_veventqs;

This should record an overflow too

Jason