Re: [Qemu-devel] [PATCH V4 10/10] vhost_net: device IOTLB support

[Jason Wang <jasowang@redhat.com>]

On 2017年01月10日 12:55, Michael S. Tsirkin wrote:
> On Fri, Dec 30, 2016 at 06:09:19PM +0800, Jason Wang wrote:
>> This patches implements Device IOTLB support for vhost kernel. This is
>> done through:
>>
>> 1) switch to use dma helpers when map/unmap vrings from vhost codes
>> 2) introduce a set of VhostOps to:
>>     - setting up device IOTLB request callback
>>     - processing device IOTLB request
>>     - processing device IOTLB invalidation
>> 2) kernel support for Device IOTLB API:
>>
>> - allow vhost-net to query the IOMMU IOTLB entry through eventfd
>> - enable the ability for qemu to update a specified mapping of vhost
>> - through ioctl.
>> - enable the ability to invalidate a specified range of iova for the
>>    device IOTLB of vhost through ioctl. In x86/intel_iommu case this is
>>    triggered through iommu memory region notifier from device IOTLB
>>    invalidation descriptor processing routine.
>>
>> With all the above, kernel vhost_net can co-operate with userspace
>> IOMMU. For vhost-user, the support could be easily done on top by
>> implementing the VhostOps.
>>
>> Cc: Michael S. Tsirkin<mst@redhat.com>
>> Signed-off-by: Jason Wang<jasowang@redhat.com>
> Specifically this patch is the one causing issues.
>
>

Yes, this is because it tries to enable device IOTLB for vhost-user. 
Will post a new version for this patch.

Thanks