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Date:   Wed, 22 Mar 2023 16:44:17 +0100
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Reply-To: eric.auger@redhat.com
Subject: Re: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain helper
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To:     Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>,
        Nicolin Chen <nicolinc@nvidia.com>,
        "lpieralisi@kernel.org" <lpieralisi@kernel.org>
Cc:     Jason Gunthorpe <jgg@nvidia.com>,
        "robin.murphy@arm.com" <robin.murphy@arm.com>,
        "will@kernel.org" <will@kernel.org>,
        "kevin.tian@intel.com" <kevin.tian@intel.com>,
        "baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
        "joro@8bytes.org" <joro@8bytes.org>,
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        "linux-arm-kernel@lists.infradead.org" 
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        "iommu@lists.linux.dev" <iommu@lists.linux.dev>,
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From:   Eric Auger <eric.auger@redhat.com>
In-Reply-To: <7726b990f7c4486d9f3597979ebc4e7e@huawei.com>
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Hi,

On 3/16/23 20:56, Shameerali Kolothum Thodi wrote:
>
>> -----Original Message-----
>> From: Nicolin Chen [mailto:nicolinc@nvidia.com]
>> Sent: 16 March 2023 19:51
>> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;
>> Eric Auger <eric.auger@redhat.com>
>> Cc: Jason Gunthorpe <jgg@nvidia.com>; robin.murphy@arm.com;
>> will@kernel.org; kevin.tian@intel.com; baolu.lu@linux.intel.com;
>> joro@8bytes.org; jean-philippe@linaro.org;
>> linux-arm-kernel@lists.infradead.org; iommu@lists.linux.dev;
>> linux-kernel@vger.kernel.org
>> Subject: Re: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain
>> helper
>>
>> Hi Shameer/Eric,
>>
>> On Fri, Mar 10, 2023 at 04:30:03PM +0000, Shameerali Kolothum Thodi
>> wrote:
>>> External email: Use caution opening links or attachments
>>>
>>>
>>>> -----Original Message-----
>>>> From: Jason Gunthorpe [mailto:jgg@nvidia.com]
>>>> Sent: 10 March 2023 16:21
>>>> To: Shameerali Kolothum Thodi
>> <shameerali.kolothum.thodi@huawei.com>
>>>> Cc: Eric Auger <eric.auger@redhat.com>; Nicolin Chen
>>>> <nicolinc@nvidia.com>; robin.murphy@arm.com; will@kernel.org;
>>>> kevin.tian@intel.com; baolu.lu@linux.intel.com; joro@8bytes.org;
>>>> jean-philippe@linaro.org; linux-arm-kernel@lists.infradead.org;
>>>> iommu@lists.linux.dev; linux-kernel@vger.kernel.org
>>>> Subject: Re: [PATCH v1 01/14] iommu: Add
>> iommu_get_unmanaged_domain
>>>> helper
>>>>
>>>> On Fri, Mar 10, 2023 at 04:07:38PM +0000, Shameerali Kolothum Thodi
>>>> wrote:
>> https://lore.kernel.org/linux-arm-kernel/20220420164836.1181-5-shame
>>>> er
>>>>>>> ali.kolothum.thodi@huawei.com/
>>>>>> So "boot configration" is more like "don't change the RIDs"? Ie
>>>>>> don't
>>>> enable
>>>>>> SRIOV?
>>>>> Yes. Don't think it will work with SR-IOV if you can't guarantee
>>>>> the RMR
>>>> specified
>>>>> SID.
>>>> So I think we are probably good them because vSR-IOV is already not
>>>> supported by qemu, so it impossible for a VM to change the PCI
>>>> configuration in a way that would alter the RID to SID mapping?
>>>>
>>> Provided we fix the issue mentioned by Eric. This was discussed here
>>> previously,
>>>
>>> https://lore.kernel.org/linux-arm-kernel/bb3688c7-8f42-039e-e22f-65290
>>> 78da97d@redhat.com/
>> Have we fixed the issue? I saw Lorenzo replying in that thread:
>> https://lore.kernel.org/linux-arm-kernel/Yi8nV8H4Jjlpadmk@lpieralisi/
>>
>> Or, what's remaining here regarding this topic? Is it a blocker?
> [+Lorenzo]

I am not aware of any change in the situation.

Thanks

Eric
>
> Not sure it is fixed yet. Also, assuming we take RMR path, do we plan to support 
> DT base Guests at all?
>
> Thanks,
> Shameer
>