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Date:   Wed, 14 Apr 2021 08:26:02 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Lu Baolu <baolu.lu@linux.intel.com>
Cc:     Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        LKML <linux-kernel@vger.kernel.org>,
        iommu@lists.linux-foundation.org, Joerg Roedel <joro@8bytes.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Yi Liu <yi.l.liu@intel.com>, Raj Ashok <ashok.raj@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>,
        Dave Jiang <dave.jiang@intel.com>, wangzhou1@hisilicon.com,
        zhangfei.gao@linaro.org, vkoul@kernel.org
Subject: Re: [PATCH 2/2] iommu/sva: Remove mm parameter from SVA bind API
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On Wed, Apr 14, 2021 at 02:22:09PM +0800, Lu Baolu wrote:

> I still worry about supervisor pasid allocation.
> 
> If we use iommu_sva_alloc_pasid() to allocate a supervisor pasid, which
> mm should the pasid be set? I've ever thought about passing &init_mm to
> iommu_sva_alloc_pasid(). But if you add "mm != current->mm", this seems
> not to work. Or do you prefer a separated interface for supervisor pasid
> allocation/free?

Without a mm_struct it is not SVA, so don't use SVA APIs for whatever
a 'supervisor pasid' is

Jason