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Message-ID: <9e786a91-6239-1fa5-cad9-f319794b6055@linux.intel.com>
Date:   Fri, 20 May 2022 19:03:02 +0800
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Cc:     baolu.lu@linux.intel.com, Jason Gunthorpe <jgg@nvidia.com>,
        Christoph Hellwig <hch@infradead.org>,
        Kevin Tian <kevin.tian@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Eric Auger <eric.auger@redhat.com>,
        Liu Yi L <yi.l.liu@intel.com>,
        Jacob jun Pan <jacob.jun.pan@intel.com>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] iommu: Add blocking_domain_ops field in iommu_ops
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To:     Joerg Roedel <joro@8bytes.org>
References: <20220516015759.2952771-1-baolu.lu@linux.intel.com>
 <20220516015759.2952771-3-baolu.lu@linux.intel.com>
 <YodVJ7ervpIdWfg+@8bytes.org>
From:   Baolu Lu <baolu.lu@linux.intel.com>
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On 2022/5/20 16:45, Joerg Roedel wrote:
> On Mon, May 16, 2022 at 09:57:56AM +0800, Lu Baolu wrote:
>>   	const struct iommu_domain_ops *default_domain_ops;
>> +	const struct iommu_domain_ops *blocking_domain_ops;
> 
> I don't understand why extra domain-ops are needed for this. I think it
> would be more straight-forward to implement allocation of
> IOMMU_DOMAIN_BLOCKED domains in each driver and let the details be
> handled in the set_dev() call-back. The IOMMU driver can make sure DMA
> is blocked for a device when it encounters a IOMMU_DOMAIN_BLOCKED
> domain.
> 
> For IOMMUs that have no explicit way to block DMA could just use an
> unmanaged domain with an empty page-table.

Yes, this is what will go.

Best regards,
baolu