Re: [RFC PATCH 12/42] iommufd: Introduce allocation data info and flag for KVM managed HWPT

[Yan Zhao]

On Mon, Dec 04, 2023 at 02:29:28PM -0400, Jason Gunthorpe wrote:
> On Sat, Dec 02, 2023 at 05:21:13PM +0800, Yan Zhao wrote:
> 
> > @@ -413,11 +422,13 @@ struct iommu_hwpt_arm_smmuv3 {
> >   * @IOMMU_HWPT_DATA_NONE: no data
> >   * @IOMMU_HWPT_DATA_VTD_S1: Intel VT-d stage-1 page table
> >   * @IOMMU_HWPT_DATA_ARM_SMMUV3: ARM SMMUv3 Context Descriptor Table
> > + * @IOMMU_HWPT_DATA_KVM: KVM managed stage-2 page table
> >   */
> >  enum iommu_hwpt_data_type {
> >  	IOMMU_HWPT_DATA_NONE,
> >  	IOMMU_HWPT_DATA_VTD_S1,
> >  	IOMMU_HWPT_DATA_ARM_SMMUV3,
> > +	IOMMU_HWPT_DATA_KVM,
> >  };
> 
> Definately no, the HWPT_DATA is for the *driver* - it should not be
> "kvm".
> 
> Add the kvm fd to the main structure
>
Do you mean add a "int kvm_fd" to "struct iommu_hwpt_alloc" ?
struct iommu_hwpt_alloc {
        __u32 size;
        __u32 flags;
        __u32 dev_id;
        __u32 pt_id;
        __u32 out_hwpt_id;
        __u32 __reserved;
        __u32 data_type;
        __u32 data_len;
        __aligned_u64 data_uptr;
};

Then always create the HWPT as IOMMUFD_OBJ_HWPT_KVM as long as kvm_fd > 0 ?