Re: [PATCH v4 05/15] memory/iommu: Add IOMMU_ATTR_DMA_TRANSLATION attribute

[Eric Auger <eauger@redhat.com>]

Hi Joao,

On 6/22/23 23:48, Joao Martins wrote:
> Add a new IOMMU attribute IOMMU_ATTR_DMA_TRANSLATION which indicates
> whether the IOMMU supports DMA Translation.
doesn't it return whether the DMA translation is enabled instead?
> 
> This attribute will be used by VFIO device dirty page tracking so it can
> restrict the IOVA under tracking to the memory map when vIOMMU is
> enabled only for interrupt remapping without dma translation enabled.
The above sentence sounds a bit cryptic to me. Knowing whether DMAR is
enabled allows you to restrict the scope of dirty page tracking, is that
a correct understand?

Thanks

Eric
> 
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> ---
>  include/exec/memory.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 47c2e0221c35..5d6c2ab1f397 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -319,7 +319,8 @@ typedef struct MemoryRegionClass {
>  
>  
>  enum IOMMUMemoryRegionAttr {
> -    IOMMU_ATTR_SPAPR_TCE_FD
> +    IOMMU_ATTR_SPAPR_TCE_FD,
> +    IOMMU_ATTR_DMA_TRANSLATION,
>  };
>  
>  /*