Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs
From: Jacob Pan <hidden>
Date: 2021-03-19 00:20:49
Also in:
linux-iommu, lkml
Hi Jean, Slightly off the title. As we are moving to use cgroup to limit PASID allocations, it would be much simpler if we enforce on the current task. However, iommu_sva_alloc_pasid() takes an mm_struct pointer as argument which implies it can be something other the the current task mm. So far all kernel callers use current task mm. Is there a use case for doing PASID allocation on behalf of another mm? If not, can we remove the mm argument? Thanks, Jacob
quoted hunk ↗ jump to hunk
/** * iommu_sva_alloc_pasid - Allocate a PASID for the mm@@ -35,11 +44,11 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm,ioasid_t min, ioasid_t max) mutex_lock(&iommu_sva_lock); if (mm->pasid) { if (mm->pasid >= min && mm->pasid <= max) - ioasid_get(mm->pasid); + ioasid_get(iommu_sva_pasid, mm->pasid); else ret = -EOVERFLOW; } else { - pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm); + pasid = ioasid_alloc(iommu_sva_pasid, min, max, mm); if (pasid == INVALID_IOASID) ret = -ENOMEM;
Thanks, Jacob