Re: [Qemu-devel] [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices

[Alexey Kardashevskiy]

On 08/11/16 17:52, Alexey Kardashevskiy wrote:
> On 05/11/16 08:10, Kirti Wankhede wrote:
>> VFIO IOMMU drivers are designed for the devices which are IOMMU capable.
>> Mediated device only uses IOMMU APIs, the underlying hardware can be
>> managed by an IOMMU domain.
>>
>> Aim of this change is:
>> - To use most of the code of TYPE1 IOMMU driver for mediated devices
>> - To support direct assigned device and mediated device in single module
>>
>> This change adds pin and unpin support for mediated device to TYPE1 IOMMU
>> backend module. More details:
>> - vfio_pin_pages() callback here uses task and address space of vfio_dma,
>>   that is, of the process who mapped that iova range.
>> - Added pfn_list tracking logic to address space structure. All pages
>>   pinned through this interface are trached in its address space.
>> - Pinned pages list is used to verify unpinning request and to unpin
>>   remaining pages while detaching the group for that device.
>> - Page accounting is updated to account in its address space where the
>>   pages are pinned/unpinned.
>> -  Accouting for mdev device is only done if there is no iommu capable
>>   domain in the container. When there is a direct device assigned to the
>>   container and that domain is iommu capable, all pages are already pinned
>>   during DMA_MAP.
>> - Page accouting is updated on hot plug and unplug mdev device and pass
>>   through device.
>>
>> Tested by assigning below combinations of devices to a single VM:
>> - GPU pass through only
> 
> This does not require this patchset, right?
> 
>> - vGPU device only
> 
> Out of curiosity - how exactly did you test this? The exact GPU, how to
> create vGPU, what was the QEMU command line and the guest does with this
> passed device? Thanks.


ping?


-- 
Alexey