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

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Jan 02, 2025 at 07:30:21PM -0800, Nicolin Chen wrote:
> 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);
> -------------------------------------------------------------------------

Yeah, that's right

Jason