[PATCH v3 06/14] iommufd: Add IOMMUFD_OBJ_VIRQ and IOMMUFD_CMD_VIRQ_ALLOC

[Jason Gunthorpe]

On Tue, Dec 17, 2024 at 09:00:19PM -0800, Nicolin Chen wrote:
> +/* An iommufd_virq_header packs a vIOMMU interrupt in an iommufd_virq queue */
> +struct iommufd_virq_header {
> +	struct list_head node;
> +	ssize_t irq_len;
> +	void *irq_data;
> +};

Based on how it is used in iommufd_viommu_report_irq()

+       header = kzalloc(sizeof(*header) + irq_len, GFP_KERNEL);
+       header->irq_data = (void *)header + sizeof(*header);
+       memcpy(header->irq_data, irq_ptr, irq_len);

It should be a flex array and use the various flexarray tools

struct iommufd_virq_header {
       ssize_t irq_len;
       u64 irq_data[] __counted_by(irq_len);
}

Jason