Re: [RFC v7 09/26] vfio: Force nested if iommu requires it

[Auger Eric]

Hi Kunkun,

On 11/28/20 10:01 AM, Kunkun Jiang wrote:
> Hi Eric,
>> @@ -1668,6 +1679,14 @@ static int vfio_connect_container(VFIOGroup *group, 
>> AddressSpace *as,
>>      VFIOContainer *container;
>>      int ret, fd;
>>      VFIOAddressSpace *space;
>> +    IOMMUMemoryRegion *iommu_mr;
>> +    bool nested = false;
>> +
>> +    if (as != &address_space_memory && memory_region_is_iommu(as->root)) {
>> +        iommu_mr = IOMMU_MEMORY_REGION(as->root);
>> +        memory_region_iommu_get_attr(iommu_mr, IOMMU_ATTR_VFIO_NESTED,
>> +                                     (void *)&nested);
>> +    }
>>  
>>      space = vfio_get_address_space(as);
> Is the condition "as != &address_space_memory" needed to determine whether
> a vIOMMU is in place? I think "memory_region_is_iommu(as->root)" is enough.
> 
> Looking forward to your reply.:)

Yes I think so.

Thank you for your report!

Eric
> 
> Thanks,
> 
> Kunkun Jiang
>