Messages in this thread | | | Date | Sat, 7 Oct 2023 17:38:17 +0800 | Subject | Re: [PATCH v4 01/17] iommu: Add hwpt_type with user_data for domain_alloc_user op | From | Yi Liu <> |
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On 2023/9/27 09:08, Tian, Kevin wrote: >> From: Jason Gunthorpe <jgg@nvidia.com> >> Sent: Wednesday, September 27, 2023 12:29 AM >> >> On Tue, Sep 26, 2023 at 06:37:55AM +0000, Tian, Kevin wrote: >>>> From: Robin Murphy <robin.murphy@arm.com> >>>> Sent: Friday, September 22, 2023 5:48 PM >>>> >>>> I could go on enjoying myself, but basically yeah, "default" can't be a >>>> type in itself (at best it would be a meta-type which could be >>>> requested, such that it resolves to some real type to actually >>>> allocate), so a good name should reflect what the type functionally >>>> *means* to the user. IIUC the important distinction is that it's an >>>> abstract kernel-owned pagetable for the user to indirectly control via >>>> the API, rather than one it owns and writes directly (and thus has to be >>>> in a specific agreed format). >>>> >>> >>> IOMMU_HWPT_TYPE_KERNEL then? >>> >>> IOMMU_HWPT_TYPE_GENERIC also doesn't sound a straight word. >> >> At the end of the day this enum is the type tag for: >> >> struct iommu_hwpt_alloc { >> __u32 size; >> __u32 pt_id; >> __u32 out_hwpt_id; >> __u32 __reserved; >> + __u32 hwpt_type; >> + __u32 data_len; >> + __aligned_u64 data_uptr; >> }; >> >> That pointer. >> >> IOMMU_HWPT_ALLOC_DATA_NONE = 0 >> IOMMU_HWPT_ALLOC_DATA_INTEL_VTD >> IOMMU_HWPT_ALLOC_DATA_ARM_SMMUV3 >> >> etc? >> >> DATA_NONE requires data_len == 0 >> > > Looks good. Probably hwpt_type can be also renamed to data_type > to better match this interpretation.
ack.
-- Regards, Yi Liu
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