Message-ID: <f7b0cbef-3d7d-e5aa-1971-fe230d0c80e1@linux.intel.com>
Date:   Tue, 7 Mar 2023 09:41:42 +0800
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Cc:     baolu.lu@linux.intel.com, dmaengine@vger.kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Alistair Popple <apopple@nvidia.com>,
        Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Lorenzo Stoakes <lstoakes@gmail.com>,
        Christoph Hellwig <hch@infradead.org>, iommu@lists.linux.dev
Subject: Re: [PATCH v2 08/16] iommu: define and export
 iommu_access_remote_vm()
Content-Language: en-US
To:     Fenghua Yu <fenghua.yu@intel.com>, Vinod Koul <vkoul@kernel.org>,
        Dave Jiang <dave.jiang@intel.com>
References: <20230306163138.587484-1-fenghua.yu@intel.com>
 <20230306163138.587484-9-fenghua.yu@intel.com>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <20230306163138.587484-9-fenghua.yu@intel.com>
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On 3/7/23 12:31 AM, Fenghua Yu wrote:
> Define and export iommu_access_remote_vm() to allow IOMMU related
> drivers to access user address space by PASID.
> 
> The IDXD driver would like to use it to write the user's completion
> record that the hardware device is not able to write to due to user
> page fault.

I don't quite follow here. Isn't I/O page fault already supported?

Best regards,
baolu