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    SubjectRe: [PATCH V9 02/10] iommu/uapi: Define a mask for bind data
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    Hi Jacob,

    On 1/29/20 7:01 AM, Jacob Pan wrote:
    > Memory type related guest PASID bind data can be grouped together for
    > one simple check.
    Those are flags related to memory type.
    > Link: https://lore.kernel.org/linux-iommu/20200109095123.17ed5e6b@jacob-builder/
    not sure the link is really helpful.
    >
    > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
    > ---
    > include/uapi/linux/iommu.h | 5 ++++-
    > 1 file changed, 4 insertions(+), 1 deletion(-)
    >
    > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
    > index 4ad3496e5c43..fcafb6401430 100644
    > --- a/include/uapi/linux/iommu.h
    > +++ b/include/uapi/linux/iommu.h
    > @@ -284,7 +284,10 @@ struct iommu_gpasid_bind_data_vtd {
    > __u32 pat;
    > __u32 emt;
    > };
    > -
    > +#define IOMMU_SVA_VTD_GPASID_EMT_MASK (IOMMU_SVA_VTD_GPASID_CD | \
    > + IOMMU_SVA_VTD_GPASID_EMTE | \
    > + IOMMU_SVA_VTD_GPASID_PCD | \
    > + IOMMU_SVA_VTD_GPASID_PWT)
    Why EMT rather than MT or MTS?
    the spec says:
    Those fields are treated as Reserved(0) for implementations not
    supporting Memory Type (MTS=0 in Extended Capability Register).

    > /**
    > * struct iommu_gpasid_bind_data - Information about device and guest PASID binding
    > * @version: Version of this data structure
    >

    Thanks

    Eric

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