[Issue]: TopoSystem::MatchGpuAndNic segfaults on RDNA 4 (gfx1201) + Pollara ionic NICs

[jlochhead]

Problem Description

I have a small GPU lab with two machines, each has 2 x R9700 PCIe GPUs and 2 x Pollara NICs. I wanted to run disaggregated inference with MoRI instead of RIXL, but I encountered this issue.

I didn't submit a PR because I'm not sure if you want PCIe GPUs supported.

Hardware:

• GPU: AMD Radeon AI PRO R9700 (gfx1201, RDNA 4)
• NIC: AMD Pollara AI NIC (ionic_0, ionic_1)
• ROCm: 7.2.0
• MoRI: bundled in vllm/vllm-openai-rocm:nightly (vLLM 0.22.1rc1)

Symptom:MoRIIOConnector segfaults on first KV transfer request with the following stack trace:

mori::application::CollectAndSortCandidates mori::application::TopoSystem::MatchAllGpusAndNics mori::application::TopoSystem::MatchGpuAndNic mori::io::RdmaManager::Search mori::io::ControlPlaneServer::BuildRdmaConn mori::io::RdmaBackend::CreateSession

Root cause:
In src/application/topology/pci.cpp, CreateTopoNodePciFrom() only recognizes PCI class 0x1200 (Processing Accelerator) as a GPU:

cpp

} else if (cls == 0x1200) {
    return TopoNodePci::CreateGpu(bus, numa);
}

RDNA 4 consumer/workstation GPUs (R9700) enumerate as PCI class 0x0300 (VGA compatible controller).

Proposed fix:

} else if (cls == 0x1200 || cls == 0x0300 || cls == 0x0302) {
    return TopoNodePci::CreateGpu(bus, numa);
}

Where 0x0302 covers 3D controllers used by some workstation GPUs.

Verification:
Applied this fix locally, rebuilt MoRI, and confirmed P/D disaggregation works end-to-end on R9700 + Pollara NICs with no segfault.

Operating System

Ubuntu 24.04

CPU

AMD EPYC 9535 64-Core Processor

GPU

AMD R9700

ROCm Version

RoCM 7.2

ROCm Component

No response

Steps to Reproduce

No response

(Optional for Linux users) Output of /opt/rocm/bin/rocminfo --support

rocminfo --support output

Paste output here

Additional Information

No response

[jhchouuu]

Hi @jlochhead thanks for the information.
Amazing work! In fact, we haven't even attempted to run mori on nodes with 2 x R9700 PCIe GPUs and 2 x Pollara NICs.
If it's only the part of the fix that you mentioned, I don't think it will have any impact. So feel free to raise a PR about this.

[jhchouuu]

Hi @jlochhead , We are very interested in your work of running mori on the R9700 + AINIC. Could you please share any code or performance data? thanks!!!

[jlochhead]

Sure. I can share a document on the setup and some benchmark data. How would you like me to share it with you?

[jhchouuu]

Sure. I can share a document on the setup and some benchmark data. How would you like me to share it with you?

Thanks @jlochhead ! Either works for me, if the setup doc and benchmark data are OK to share publicly, feel free to attach them here or open a short PR. If any of it isn't public, just email me at jiahzhou@amd.com and we'll take it from there. Appreciate it!