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

[Nicolin Chen <nicolinc@nvidia.com>]

On Thu, Jan 02, 2025 at 04:52:46PM -0400, Jason Gunthorpe wrote:
> 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);
> }

Changed to
-------------------------------------------------------------------------
/* An iommufd_vevent represents a vIOMMU event in an iommufd_veventq */
struct iommufd_vevent {
	struct list_head node;
	ssize_t data_len;
	u64 event_data[] __counted_by(data_len);
};
[...]
	vevent = kmalloc(struct_size(vevent, event_data, data_len), GFP_KERNEL);
-	header->irq_data = (void *)header + sizeof(*header);
-------------------------------------------------------------------------

Thanks
Nicolin