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Subject: Re: [PATCH 1/1] iommu/arm-smmu-v3: add support for BBML
To:     Will Deacon <will@kernel.org>, Robin Murphy <robin.murphy@arm.com>
CC:     Joerg Roedel <joro@8bytes.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        iommu <iommu@lists.linux-foundation.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Yang Yingliang <yangyingliang@huawei.com>
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From:   "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
Message-ID: <8a9685ec-67aa-824f-5429-f408bf79c5ab@huawei.com>
Date:   Wed, 27 Jan 2021 10:01:34 +0800
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On 2021/1/26 18:12, Will Deacon wrote:
> On Mon, Jan 25, 2021 at 08:23:40PM +0000, Robin Murphy wrote:
>> Now we probably will need some degreee of BBML feature awareness for the
>> sake of SVA if and when we start using it for CPU pagetables, but I still
>> cannot see any need to consider it in io-pgtable.
> 
> Agreed; I don't think this is something that io-pgtable should have to care
> about.

Yes, the SVA works in stall mode, and the failed device access requests are not
discarded.

Let me look for examples. The BBML usage scenario was told by a former colleague.

> 
> Will
> 
> .
>