Re: [PATCH v4 10/23] iommufd/viommu: Introduce IOMMUFD_OBJ_HW_QUEUE and its related struct

Jason Gunthorpe
2025-05-15T15:39:08Z

On Thu, May 08, 2025 at 08:02:31PM -0700, Nicolin Chen wrote:
> +#define iommufd_hw_queue_alloc(viommu, drv_struct, member) \
> + ({ \
> + drv_struct *ret; \
> + \
> + static_assert(__same_type(struct iommufd_viommu, *viommu)); \
> + static_assert(__same_type(struct iommufd_hw_queue, \
> + ((drv_struct *)NULL)->member)); \
> + static_assert(offsetof(drv_struct, member.obj) == 0); \
> + ret = (drv_struct *)_iommufd_object_alloc( \
> + viommu->ictx, sizeof(drv_struct), \
> + IOMMUFD_OBJ_HW_QUEUE); \
> + if (!IS_ERR(ret)) { \
> + ret->member.viommu = viommu; \
> + ret->member.ictx = viommu->ictx; \
> + } \
> + ret; \
> + })

This should just call

__iommufd_object_alloc(viommu->ictx, ret, IOMMUFD_OBJ_HW_QUEUE member.obj)

And all the casting and asserts should be in that macro, move it to
this header

> /* Helper for IOMMU driver to destroy structures created by allocators above */
> #define iommufd_struct_destroy(drv_struct, member) \
> ({ \

This is abort not destroy, the names should be consistent. But looking
more at the series I think it will be better to do the little rework I
suggested and not give this function to the driver in the first place.

Jason