Re: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain helper

[Eric Auger]

Hi,

On 3/16/23 20:56, Shameerali Kolothum Thodi wrote:
>
>> -----Original Message-----
>> From: Nicolin Chen [mailto:nicolinc@xxxxxxxxxx]
>> Sent: 16 March 2023 19:51
>> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>;
>> Eric Auger <eric.auger@xxxxxxxxxx>
>> Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>; robin.murphy@xxxxxxx;
>> will@xxxxxxxxxx; kevin.tian@xxxxxxxxx; baolu.lu@xxxxxxxxxxxxxxx;
>> joro@xxxxxxxxxx; jean-philippe@xxxxxxxxxx;
>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; iommu@xxxxxxxxxxxxxxx;
>> linux-kernel@xxxxxxxxxxxxxxx
>> 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@xxxxxxxxxx]
>>>> Sent: 10 March 2023 16:21
>>>> To: Shameerali Kolothum Thodi
>> <shameerali.kolothum.thodi@xxxxxxxxxx>
>>>> Cc: Eric Auger <eric.auger@xxxxxxxxxx>; Nicolin Chen
>>>> <nicolinc@xxxxxxxxxx>; robin.murphy@xxxxxxx; will@xxxxxxxxxx;
>>>> kevin.tian@xxxxxxxxx; baolu.lu@xxxxxxxxxxxxxxx; joro@xxxxxxxxxx;
>>>> jean-philippe@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
>>>> iommu@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
>>>> 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@xxxxxxxxxx/
>>>>>> 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@xxxxxxxxxx/
>> 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
>