DOCA DPDK Bridge

Examples

• "How do I add DOCA Flow to my DPDK app?" — this is in scope. Bind the DPDK port with doca_dpdk_port_probe; do not rewrite the data-plane as native doca-eth.
• "DOCA_ERROR_NOT_FOUND on port registration." — check the DPDK/DOCA matched-pair window before changing the probe call.

Instructions

Follow Loading order below. Open the tasks companion for configure / probe / debug. Open the capabilities companion for port binding and mbuf conversion. Do not open every companion file.

Where to start: This skill assumes DOCA is already installed, DPDK is already installed, the user has an existing DPDK application, and they want to add DOCA capabilities to it in-place (most commonly DOCA Flow for hardware steering) without migrating the data-plane to DOCA-native APIs. Open the tasks companion if the user wants to do something (configure / build / modify / run / test / debug); open the capabilities companion when the question is what the bridge can express on this version. If the user has not installed DOCA yet, route to doca-setup first. If the user is starting fresh (no DPDK code yet) and just wants line-rate packet I/O against DOCA, route to doca-eth instead — the bridge exists for the interop case, not the start-fresh case.

How to use this skill. Read this file, then search the companion file for the ## <name> heading the question needs and read that whole section. Answer completely from it, quoting only its symbols and commands. Do not browse docs; use the entry points in doca-public-knowledge-map. Give environment checks as commands for the user's DOCA host. For out-of-scope requests, name the skill that owns them and stop.

Example questions this skill answers well

The CLASSES of DOCA DPDK Bridge questions this skill is built to answer, each with one worked example. The agent should treat the class as the load-bearing piece — the worked example is a single instance.

• "I have a DPDK app — how do I add DOCA Flow rules to it without rewriting the data-plane?" — worked example: "my packet-processing app already drives mbufs through rte_eth_* ports; I want to install DOCA Flow steering rules on those ports for HW offload". Answered by the bridge-vs-native selection rule in

  Capabilities and modes

  • the port-handover workflow in

  configure step 3.

• "How do I make a DPDK port visible to DOCA?" — worked example: "I have a DPDK port id from rte_eth_dev_*; how does DOCA see it". Answered by the DPDK-port-id ↔ doca_dev mapping (doca_dpdk_port_probe / doca_dpdk_port_as_dev) in

  Capabilities and modes

  bridge-objects table + the binding workflow in

  configure step 4.

• "How do I move packets between DPDK mbufs and DOCA bufs?" — worked example: "DPDK delivers an rte_mbuf to my fastpath; I want a DOCA library to operate on the payload". Answered by the mbuf ↔ DOCA-buf conversion shape in

  Capabilities and modes

  • the conversion-step workflow in

  modify.

• "Is the bridge even installed and is its DPDK compatible with my DOCA?" — worked example: "pkg-config --exists doca-dpdk-bridge returns failure on a host that has DPDK separately installed". Answered by the version-coupling rule in

  Version compatibility

  • the cap-check workflow in

  configure step 1.

• "Should I be using doca-dpdk-bridge or doca-eth?" — worked example: "new project; I have not committed to DPDK yet". Answered by the path-selection table in

  Capabilities and modes

  bridge-vs-native row + the deferred-verbs note in

  Deferred task verbs.

• "What does this DOCA_ERROR_* from a bridge call mean and which layer caused it?" — worked example: "DOCA_ERROR_NOT_FOUND on a port-registration call after the DPDK port came up cleanly". Answered by the bridge overlay on the cross-library taxonomy in

  Error taxonomy

  • the layered ladder in

  debug that escalates to

  doca-debug.

Audience

This skill serves external developers who already maintain a DPDK-based packet-processing application — i.e., users whose data-plane already drives rte_eth_* ports and rte_mbuf buffers — and who want to add DOCA capabilities (most commonly hardware steering via DOCA Flow) by linking the bridge into the same process. It is not for users starting a fresh DOCA-native project (route to doca-eth) and not for users running pure DPDK with no interest in DOCA (no skill in this bundle applies). It is also not for NVIDIA developers contributing to DOCA DPDK Bridge itself.

Language scope. DOCA DPDK Bridge ships as a C library with pkg-config module name doca-dpdk-bridge (the agent must confirm the spelling against the user's install via pkg-config --exists doca-dpdk-bridge; some DOCA releases use a slightly different module name and the agent must not guess). The shipped samples are written in C. C and C++ consumers are the canonical case; the worked examples in the tasks companion assume that path. Other-language consumers (Rust, Go, Python, …) typically do not use this bridge — DPDK itself is C-shaped, and a non-C DPDK app is rare; if the user is in that minority, the skill's contribution is to keep the port-handover, capability, permission, and error-taxonomy guidance language-neutral and route them to the public C ABI as the authoritative surface.

When to load this skill

Load this skill when the user is doing hands-on DOCA DPDK Bridge work, in any language. Concretely:

• The user has an EXISTING DPDK application (their data-plane already drives rte_eth_dev_* ports and rte_mbuf buffers), and they want to layer DOCA on top — adding DOCA Flow rules, feeding packets into a DOCA accelerator (Compress, AES-GCM, …), or wiring a DOCA service into the same process.
• The user needs to bind a DPDK port id to a doca_dev (via doca_dpdk_port_probe / doca_dpdk_port_as_dev) so DOCA Core / DOCA Flow can operate on the same physical port.
• The user needs to convert between DPDK mbufs and DOCA-bufs at the data-plane boundary, and is asking about the conversion helpers and their cost.
• The user is debugging a DOCA_ERROR_* returned from a bridge call (lifecycle vs. permission vs. capability vs. DPDK-port-not- registered vs. mbuf-conversion-failed) and the layered DPDK ↔ DOCA stack underneath.
• The user is hitting cross-version pain: their DPDK install and their DOCA install are not the matched pair the bridge expects.
• The user is asking "native doca-eth or doca-dpdk-bridge?" and the agent needs the path-selection rule.

Do not load this skill for general DOCA orientation, install of DOCA itself, fresh DOCA-native packet I/O (use doca-eth), flow-rule programming on its own (use doca-flow), host ↔ DPU control messaging (use doca-comch), or RDMA data movement (use doca-rdma). For DOCA documentation orientation, use doca-public-knowledge-map.

What this skill provides

This is a thin loader. The body keeps only the orientation needed to pick the right next file. The substantive bridge- specific material lives in two companion files:

• the capabilities companion — what the DOCA DPDK Bridge can express on this version: the bridge-vs-native selection rule (when to use doca-dpdk-bridge vs native doca-eth), the bridge-object surface (DPDK-port-id ↔ doca_dev mapping, the doca_dpdk_mempool mbuf ↔ DOCA-buf conversion), the capability-query surface (the single doca_dpdk_cap_is_rep_port_supported), the bridge error taxonomy (mapped onto the cross-library DOCA_ERROR_* set), the observability surface (DPDK-side counters + DOCA-side PE events), and the safety policy that gates the matched-pair DPDK ↔ DOCA version coupling, the EAL-must-be-up precondition, and DPDK-side privileges.
• the tasks companion — step-by-step workflows for the six in-scope bridge verbs: configure, build, modify, run, test, debug. Plus a Deferred task verbs block that points out-of-scope questions at the right next skill, and a Command appendix of the recurring commands the agent reaches for.

The skill assumes a host or BlueField where DOCA AND DPDK are already installed at the standard locations and the user has the privileges their public install profile expects (typically sudo or mlnx-group membership for DOCA, plus the DPDK-side privileges to mount hugepages, bind PCIe ports, and open the target rte_eth device). It does not cover installing DOCA — that path goes through doca-setup; it does not cover installing or learning DPDK itself — that belongs in upstream DPDK documentation reachable via doca-public-knowledge-map.

What this skill deliberately does not ship

This skill is agent guidance, not a samples or templates bundle. To keep the boundary clean, it deliberately does not contain — and pull requests should not add:

• Pre-written DOCA DPDK Bridge application source code, in any language. The verified bridge source code is the bridge usage inside the shipped C DOCA Flow samples at /opt/mellanox/doca/samples/doca_flow/ (e.g. flow_common.c, which calls doca_dpdk_port_probe() / doca_dpdk_port_as_dev()), plus the canonical reference applications that pair DPDK + DOCA Flow (see doca-public-knowledge-map for the reference-applications index). The agent's job is to route the user to those files and prescribe a minimum-diff modification on them via the universal modify-a-sample workflow in doca-programming-guide, layered with the bridge-specific overrides in

  modify.

• Standalone build manifests (meson.build, CMakeLists.txt, Cargo.toml, …) parked inside the skill. The agent constructs the build manifest in the user's project directory against the user's installed DOCA + DPDK, where pkg-config --modversion doca-dpdk-bridge and pkg-config --modversion libdpdk are the source of truth.
• A samples/, bindings/, or reference/ subtree of any kind. A mock or incomplete artifact in this skill's tree, even one labeled "reference", is misleading: users will read it as buildable.

Loading order

1. Read this skill first to confirm the user's question is in scope (existing DPDK app + wants DOCA on top — not fresh).
2. For the bridge capability matrix, the bridge-vs-native selection rule, port-handover surface, capability-query rules, error taxonomy, observability, and safety policy, see the capabilities companion.
3. For step-by-step workflows — configure, build, modify, run, test, debug — see the tasks companion.

Both companion files cross-link to each other, doca-version for the canonical DOCA version-handling rules, doca-eth for the start-fresh path that is the bridge's deliberate alternative, doca-flow for the steering library that is the most common reason to use this bridge in the first place, and doca-public-knowledge-map whenever the right answer is "look it up in the public docs or the installed package layout" rather than "bridge-specific guidance".

Related skills

• doca-public-knowledge-map — the routing table for every public DOCA documentation source and the on-disk layout of an installed DOCA package. The bridge URL slug is DOCA-DPDK-Bridge. Reference applications that pair DPDK + DOCA Flow (the canonical adopters of this bridge) are reachable from the same map's reference- applications index.
• doca-setup — env preparation, install verification, hugepage mounts (DPDK requirement), port-state checks (devlink dev show, ip link), permission and group-membership requirements for opening a doca_dev AND for binding PCIe ports under DPDK. This skill assumes its preconditions are satisfied.
• doca-version — canonical DOCA version-handling rules. This skill's ## Version compatibility cross-links the four-way match rule and adds only the bridge-specific overlay (DPDK ↔ DOCA matched-pair coupling).
• doca-structured-tools-contract — the bundle's structured-tools precedence rule (detect / prefer / fall back / report). The Command appendix in the tasks companion honors this contract.
• doca-programming-guide — general DOCA programming patterns shared by every library: the canonical pkg-config + meson build pattern, the universal modify-a-shipped-sample first-app workflow, the universal lifecycle, the cross-library DOCA_ERROR_* taxonomy, and the program-side debug order. This skill layers bridge specifics on top.
• doca-eth — the alternative path for users starting fresh: pure DOCA-native queue I/O via doca_eth_rxq / doca_eth_txq with no DPDK in the picture. The bridge exists because migrating an existing DPDK app to doca-eth is often the wrong tradeoff; for a new project with no DPDK lock-in, doca-eth is the right choice.
• doca-flow — the steering library that is the most common reason a DPDK app reaches for this bridge. The bridge binds a DPDK port id to a doca_dev; DOCA Flow programs steering rules onto that doca_dev. The two libraries are designed to compose.
• doca-debug — the cross-cutting debug ladder (install / version / build / link / runtime / program / driver). Bridge-specific debug (DPDK ↔ DOCA version drift, port-not-registered symptoms, mbuf-conversion failures) overlays on top of that ladder.