Messages in this thread | | | Date | Mon, 25 Jul 2022 18:22:06 +0800 | Subject | Re: [PATCH v10 08/12] iommu/sva: Refactoring iommu_sva_bind/unbind_device() | From | Baolu Lu <> |
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On 2022/7/25 15:50, Tian, Kevin wrote: >> From: Baolu Lu <baolu.lu@linux.intel.com> >> Sent: Sunday, July 24, 2022 9:48 PM >>> >>> The API is really refcounting the PASID: >>> >>>> +struct iommu_sva *iommu_sva_bind_device(struct device *dev, >>>> + struct mm_struct *mm); >>>> +void iommu_sva_unbind_device(struct iommu_sva *handle); >>> >>> So what you need to do is store that 'iommu_sva' in the group's PASID >>> xarray. >>> >>> The bind logic would be >>> >>> sva = xa_load(group->pasid, mm->pasid) >>> if (sva) >>> refcount_inc(sva->users) >>> return sva >>> sva = kalloc >>> sva->domain = domain >>> xa_store(group->pasid, sva); >> >> Thanks for the suggestion. It makes a lot of sense to me. >> >> Furthermore, I'd like to separate the generic data from the caller- >> specific things because the group->pasid_array should also be able to >> serve other usages. Hence, the attach/detach_device_pasid interfaces >> might be changed like below: >> >> /* Collection of per-pasid IOMMU data */ >> struct group_pasid { >> struct iommu_domain *domain; >> void *priv; >> }; >> > > Is there any reason why pasid refcnt is sva specific and needs to be > in a priv field?
I am going to store the iommu_sva data which represents the bind relationship between device and domain.
Best regards, baolu
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