Re: [RFC PATCH 15/27] x86/virt/tdx: Extend tdx_page_array to support IOMMU_MT

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Fri, 19 Sep 2025 07:22:24 -0700
Dan Williams <dan.j.williams@intel.com> wrote:

> From: Xu Yilun <yilun.xu@linux.intel.com>
> 
> IOMMU_MT is another TDX Module defined structure similar to HPA_ARRAY_T
> and HPA_LIST_INFO. The difference is it supports multi-order contiguous
> pages. It adds an additional NUM_PAGES field for every multi-order page
> entry [1].
> 
> Add an dedicated allocation helper for IOMMU_MT. Maybe a general
> allocation helper for multi-order is better but could postpond until

postponed

> another user appears.
> 
> Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>


> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 1ae97a0b8ec7..719cc479f9e7 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1360,6 +1360,8 @@ static inline void folio_put(struct folio *folio)
>  		__folio_put(folio);
>  }
>  
> +DEFINE_FREE(folio_put, struct folio *, if (_T) folio_put(_T))

Another case of buried mm stuff that maybe could go ahead of this series
so this doesn't stall on any controversy around that.

> +
>  /**
>   * folio_put_refs - Reduce the reference count on a folio.
>   * @folio: The folio.