Re: [PATCH v10 11/11] vfio: Document nested stage control

[Auger Eric]

Hi Zenghui,

On 9/24/20 3:42 PM, Zenghui Yu wrote:
> Hi Eric,
> 
> On 2020/3/21 0:19, Eric Auger wrote:
>> The VFIO API was enhanced to support nested stage control: a bunch of
>> new iotcls, one DMA FAULT region and an associated specific IRQ.
>>
>> Let's document the process to follow to set up nested mode.
>>
>> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
> 
> [...]
> 
>> +The userspace must be prepared to receive faults. The VFIO-PCI device
>> +exposes one dedicated DMA FAULT region: it contains a ring buffer and
>> +its header that allows to manage the head/tail indices. The region is
>> +identified by the following index/subindex:
>> +- VFIO_REGION_TYPE_NESTED/VFIO_REGION_SUBTYPE_NESTED_DMA_FAULT
>> +
>> +The DMA FAULT region exposes a VFIO_REGION_INFO_CAP_PRODUCER_FAULT
>> +region capability that allows the userspace to retrieve the ABI version
>> +of the fault records filled by the host.
> 
> Nit: I don't see this capability in the code.

Thank you very much for the review. I am late doing the respin but I
will take into account all your comments.

Thanks!

Eric
> 
> 
> Thanks,
> Zenghui
>