2.1 BlueField platform

Q: A BlueField-3 should act as a plain network adapter with its Arm cores off. Which mode is that?

NIC Mode. BlueField is NVIDIA's DPU (data processing unit): a network card with its own Arm CPU cores. In DPU Mode the Arm cores run and manage the NIC. In NIC Mode, BlueField behaves like a ConnectX adapter and, on BlueField-3, the Arm cores are inactive.

NCP-AII · Physical Layer Management (5% of the exam) · Official objective: “Configure and manage a BlueField network platform.”

NIC mode vs DPU mode, and installing a BFB image through RShim.

Key points

BlueField is NVIDIA's DPU (data processing unit): a network card with its own Arm CPU cores. In DPU Mode the Arm cores run and manage the NIC. In NIC Mode, BlueField behaves like a ConnectX adapter and, on BlueField-3, the Arm cores are inactive.
What NVIDIA says (2)
“In NIC Mode, BlueField operates as a ConnectX network adapter for the external host. For BlueField-3, the Arm cores are inactive”
— DOCA: BlueField Modes of Operation
“enforcing restrictions on the external host (host isolation)”
— DOCA: BlueField Modes of Operation
A BFB (BlueField bootstream) is the bundle with the BlueField OS and firmware. RShim is the host-side driver that gives a path into the BlueField over PCIe. Each BlueField shows up as rshim0, rshim1, and so on.
What NVIDIA says (2)
“host# sudo bfb-install --rshim rshim<N> --bfb <image_path.bfb>”
— DOCA: BF-Bundle Installation and Upgrade
“To list the RShim devices present on your system, run the following command:”
— DOCA: BF-Bundle Installation and Upgrade
DPU mode turns on the BlueField's Arm cores. They run services that own the NIC and the data path. All host traffic flows through a virtual switch on those cores. In NIC mode the Arm cores are off.
What NVIDIA says (2)
“In DPU Mode, the NIC resources and functionality are owned and controlled by the embedded Arm subsystem.”
— DOCA: BlueField Modes of Operation
“BlueField-2 DPU and BlueField-3 DPU SKUs are shipped in DPU Mode by default.”
— DOCA: BlueField Modes of Operation

Key terms

BlueField DPU: A network card with its own Arm cores; in DPU mode those cores own the NIC, in NIC mode they are off.
BFB image: The bundled BlueField software image that bfb-install writes to the card through RShim.
RShim: The host-side interface used to reach and install a BlueField device from the host.

Sample question

A BlueField-3 should act as a plain network adapter with its Arm cores off. Which mode is that?

Show the answer

Answer: NIC Mode

BlueField is NVIDIA's DPU (data processing unit): a network card with its own Arm CPU cores. In DPU Mode the Arm cores run and manage the NIC. In NIC Mode, BlueField behaves like a ConnectX adapter and, on BlueField-3, the Arm cores are inactive.

What NVIDIA says (2)

“In NIC Mode, BlueField operates as a ConnectX network adapter for the external host. For BlueField-3, the Arm cores are inactive”
— DOCA: BlueField Modes of Operation

“enforcing restrictions on the external host (host isolation)”
— DOCA: BlueField Modes of Operation

Practice 2.1 (3 questions) Full Physical Layer Management guide

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