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Subject: Re: [PATCH v12 01/13] vfio: VFIO_IOMMU_SET_PASID_TABLE
To:     Zenghui Yu <yuzenghui@huawei.com>
Cc:     eric.auger.pro@gmail.com, iommu@lists.linux-foundation.org,
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References: <20210223210625.604517-1-eric.auger@redhat.com>
 <20210223210625.604517-2-eric.auger@redhat.com>
 <d0f254c3-0b63-e4d3-1f58-8940adc7c0bf@huawei.com>
From:   Auger Eric <eric.auger@redhat.com>
Message-ID: <513f8129-7ddc-f19f-e25a-e2a4b6cbe593@redhat.com>
Date:   Sun, 11 Apr 2021 14:12:27 +0200
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Hi Zenghui,

On 4/7/21 11:33 AM, Zenghui Yu wrote:
> Hi Eric,
> 
> On 2021/2/24 5:06, Eric Auger wrote:
>> +/*
>> + * VFIO_IOMMU_SET_PASID_TABLE - _IOWR(VFIO_TYPE, VFIO_BASE + 18,
>> + *            struct vfio_iommu_type1_set_pasid_table)
>> + *
>> + * The SET operation passes a PASID table to the host while the
>> + * UNSET operation detaches the one currently programmed. Setting
>> + * a table while another is already programmed replaces the old table.
> 
> It looks to me that this description doesn't match the IOMMU part.

Yep that's misleanding.

I replaced it by:

 It is allowed to "SET" the table several times without un-setting as
 long as the table config does not stay IOMMU_PASID_CONFIG_TRANSLATE.

> 
> [v14,05/13] iommu/smmuv3: Implement attach/detach_pasid_table
> 
> |    case IOMMU_PASID_CONFIG_TRANSLATE:
> |        /* we do not support S1 <-> S1 transitions */
> |        if (smmu_domain->s1_cfg.set)
> |            goto out;
> 
> Maybe I've misread something?
> 
> 
> Thanks,
> Zenghui
> 

Thanks

Eric