Re: [Qemu-devel] [Questio] What the proper vfio NIC for emulation smmu?

[Jia He]

Hi Eric

On 6/22/2018 2:39 PM, Auger Eric Wrote:
> Hello Jia,
> 
> On 06/22/2018 03:44 AM, Jia He wrote:
>> Hi Eric
>> I want to test your smmu emulation patchset with vfio-pci ethernet device.
>> Could you kindly give me the NIC type information.
>> In my test, there is vf probe error for menallox connect 4 NIC and TX Unit
>> hang error for Intel X540 NIC. That's the reason why I ask this question.
>>
> virtual SMMUv3 is not integrated with VFIO and is not planned to be. It
> was tested with virtio-net-pci (without vhost-net).
> 
> With upstream code you should see the following warning:
> 
> "SMMUV3 does not support vhost/vfio integration yet: devices of those
> types will not function properly"
> 
> With "[PATCH v3 0/4] ARM SMMUv3: IOTLB Emulation and VHOST Support",
> vhost-net gets integrated. VFIO won't be integrated either. If vfio-pci
> device are attempted to be used along with vsmmu, you will get
> "SMMUv3 does not support notification on MAP: device %s will not
> function properly"

Thanks for the information. Actually, I am using your vsmmu-optim-v3 branch.
I assumed vfio worked fine since you removed that warning in commit
("hw/arm/smmuv3: Add notifications on invalidation"). Seems I am wrong ;-)

> 
> My attempt to integrate the vsmmu with VFIO in the same manner as intel
> iommu (using a fake caching mode) was rejected by the kernel maintainer.
> So for VFIO use case, we need either 2 stage enablement (not implemented
> yet) or virtio-iommu. I will respin this latter against v0.7 spec
> probably next week.
Ok. got it, thanks
> 
> Thanks
> 
> Eric
> 

-- 
Cheers,
Jia