How do vGPU support GPUDirect RDMA/storage under SR-IOV?

From CUDA document, it is explained that GPUDirect RDMA must disable or pass-through IOMMU to work.

GPUDirect RDMA (nvidia.cn)

While Virtual GPU software claims GPUDirect RDMA is supported. So, I’m confused that whether vGPU do GPUDirect RDMA under SR-IOV platform? Rely on PCIe ATC? How can guest OS get the SPA in NIC WQ?

Thanks…