Re: [PATCH v8 14/29] iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl

Jason Gunthorpe
2025-07-09T17:09:09Z

On Fri, Jul 04, 2025 at 06:13:30PM -0700, Nicolin Chen wrote:
> +static struct iommufd_access *
> +iommufd_hw_queue_alloc_phys(struct iommu_hw_queue_alloc *cmd,
> + struct iommufd_viommu *viommu, phys_addr_t *base_pa)
> +{
> + struct iommufd_access *access;
> + struct page **pages;
> + size_t max_npages;
> + size_t length;
> + u64 offset;
> + size_t i;
> + int rc;
> +
> + offset =
> + cmd->nesting_parent_iova - PAGE_ALIGN(cmd->nesting_parent_iova);

PAGE_ALIGN is ALIGN UP, that is the wrong direction?

It is just:

offset = cmd->nesting_parent_iova % PAGE_SIZE;

And this is missing:

*base_pa = (page_to_pfn(pages[0]) << PAGE_SHIFT) + offset;

??

Jason