Quadro RTX 6000 BAR 1 size for RDMA

I want to do RDMA transfers on Nvidia Quadro RTX 6000 cards and I notice that the BAR 1 is only 256 MiB which is too little for our application case. So, I have looked around about this limitation. I found that we can potentially resize (or more technically speaking ‘rebar’) this BAR 1 for doing larger RDMA transfers. Our system is a Linux Ubuntu. For checking that the resizeable BAR is well enabled on the system, I patched nvidia.ko for printing the output of pci_rebar_get_possible_sizes, recompiled/reinstalled the nvidia.ko and it works. The function returns 0x1c0 which meems that the resizable bar feature is well enabled !.. but that the possible sizes are only 64, 128 and 256 MiB…

Is there any way to get a larger BAR 1 on Quadro RTX 6000 for doing RDMA ?

It seems that other GPUs (GeForce RTX) have larger BAR 1.

Looking at p.8 of the datasheet NVIDIA-Quadro-RTX-6000-PCIe-Server-Card-PB-FINAL-1219.pdf, it seems BAR 1 can do 32GiB…

Should enable/disable SR-IOV/ARI support in the bios ? Here is my configuration : bios configuration supermicro

The host is a SuperMicro SuperServer 4029GP-TRT