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

[Auger Eric <eric.auger@redhat.com>]

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"

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.

Thanks

Eric