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

From: Jason Gunthorpe
Date: Thu Jan 02 2025 - 15:53:03 EST


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