DOCA Rivermax

Where to start: This skill assumes DOCA is already installed, AND that the NVIDIA Rivermax SDK is separately installed with a valid Rivermax license present on the host. The agent's FIRST action on any Rivermax question is to confirm both — without Rivermax SDK + license, doca-rmax cannot function regardless of how clean the DOCA-side code is, and this is the #1 first-app confusion (DOCA does not bundle Rivermax; it wraps it). Open TASKS.md if the user wants to do something (configure / build / modify / run / test / debug); open CAPABILITIES.md when the question is what can DOCA Rivermax express on this version + this Rivermax install. If the user has not installed DOCA yet, route to doca-setup first; for the Rivermax SDK + license install itself, route to the public DOCA Rivermax guide (slug DOCA-Rivermax) via doca-public-knowledge-map. If the user is asking "how do I get packets to land on my Rivermax input stream at all", the answer is layered: doca-rmax is the Rivermax integration surface, doca-eth is the queue surface that carries the packets, and doca-flow is the steering surface that directs them.

Example questions this skill answers well

The CLASSES of DOCA Rivermax 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.

• "Can I even use doca-rmax on this host?" — worked

example: "the public docs mention `doca-rmax`; is it usable without doing anything else?". Answered by the Rivermax-SDK + license precondition rule in CAPABILITIES.md ## Safety policy + the env-prep checklist in TASKS.md ## configure step 1, which routes the install-side question to the public Rivermax guide via doca-public-knowledge-map and refuses to recommend a fallback to doca-eth alone that would silently lose the timing properties.

• "How do I set up a SMPTE ST 2110 video receive stream?" —

worked example: "line up an inbound Rivermax stream on a representor of a BlueField port for first-run testing". Answered by the per-stream object lifecycle in TASKS.md ## configure + CAPABILITIES.md ## Capabilities and modes input stream capability table.

• "Which doca_rmax_get_*_supported query do I have to call before

picking a PTP clock or hardware packet-placement order?" — worked example: "can this device + this Rivermax install use ST 2110-20 sequence-number placement?". Answered by the capability-query rule in CAPABILITIES.md ## Capabilities and modes + step 3 in TASKS.md ## configure.

• "My stream is set up but no packets arrive — why?" —

worked example: "the Rivermax stream object started cleanly but no recv events fire". Answered by the precondition matrix in CAPABILITIES.md ## Safety policy + the env-prep checklist in TASKS.md ## configure step 1, which routes the steering side to doca-flow, the queue side to doca-eth, and the license side back to the Rivermax-side precondition.

• "Is this Rivermax integration capability available on my

device + my installed DOCA + my Rivermax SDK?" — worked example: "does this device + this Rivermax version advertise the PTP clock or placement mode I need". Answered by the capability-query rule in CAPABILITIES.md ## Capabilities and modes + the version-and-device overlay in CAPABILITIES.md ## Version compatibility, which adds the Rivermax-side version is a second axis rule on top of the canonical DOCA version-handling chain in doca-version.

• "What does this DOCA_ERROR_* from a Rivermax call mean and

which layer caused it?" — worked example: "`DOCA_ERROR_NOT_SUPPORTED` from `doca_rmax_init()`". Answered by the Rivermax overlay on the cross-library taxonomy in CAPABILITIES.md ## Error taxonomy + the layered ladder in TASKS.md ## debug that escalates to doca-debug, and which preserves the installed header's call-specific mapping: init-time _NOT_SUPPORTED routes first to Rivermax SDK / license checks; later errors are interpreted from the exact failing call rather than generalized into a license diagnosis.

Audience

This skill serves external developers building applications that consume the DOCA Rivermax integration — i.e., users whose code calls doca_rmax_* (directly in C/C++, or through FFI/bindings from another language) to drive timing-precise media-over-IP streams (SMPTE ST 2110, real-time market data, high-throughput scientific instrument streams) on top of a separately-installed NVIDIA Rivermax SDK on a BlueField or ConnectX host. It is not for NVIDIA developers contributing to DOCA Rivermax itself, and it is not for users who want best-effort packet I/O — for that, route to doca-eth directly.

Language scope. DOCA Rivermax ships as a C library with pkg-config module name doca-rmax. The shipped samples live under /opt/mellanox/doca/samples/doca_rmax/ and are written in C. C and C++ consumers are the canonical case; the worked examples in TASKS.md assume that path. Other-language consumers (Rust, Go, Python, …) consume the same *.so through FFI or language-specific bindings; the skill's contribution in that case is to keep the precondition rule (Rivermax SDK + license), per-stream lifecycle, capability-discovery, permission, scheduling-discipline, and error-taxonomy guidance language-neutral, and to route the agent to the public C ABI as the authoritative surface that any wrapper will eventually call.

When to load this skill

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

• Confirming that the NVIDIA Rivermax SDK and a valid Rivermax

license are present on the host before any DOCA-side code is written — this is a mandatory precondition, not an error path; without it the answer is "`doca-rmax` cannot be used; pick a different library", not "let's try and see what fails".

• Initializing the global DOCA Rivermax engine with

doca_rmax_init() / doca_rmax_release(), then creating a doca_rmax_in_stream (receive) context with doca_rmax_in_stream_create() on a doca_dev opened against a physical port, a representor, or an SF, and converting it via doca_rmax_in_stream_as_ctx() before doca_ctx_start(). The public DOCA Rivermax API is receive-only — there is no transmit/output stream object.

• Configuring a Rivermax input stream for SMPTE ST 2110 audio +

video over IP, real-time market data feeds, or a scientific instrument stream — with awareness that PTP-clock and hardware packet-placement-order support are device- and Rivermax-conditional and gate on the matching doca_rmax_get_*_supported query.

• Reading or setting Rivermax stream properties via

doca_rmax_in_stream_set_* and querying device + Rivermax capability via the doca_rmax_get_*_supported family before assuming PTP-clock or hardware packet-placement-order support.

• Pairing the Rivermax stream with the doca-eth queue surface

that carries the packets and the doca-flow rules that steer them — Rivermax does not program steering itself.

• Designing the real-time scheduling discipline for the

streaming threads (the underlying Rivermax stack expects real-time priority for sub-microsecond jitter; the canonical scheduling guidance lives in the Rivermax SDK docs reachable through doca-public-knowledge-map).

• Debugging a DOCA_ERROR_* returned from a Rivermax call

(lifecycle vs. license / permission vs. capability vs. driver-below) where the cause may live in the DOCA-side wrapper, the underlying Rivermax stack, or the licensing layer.

• Designing or extending non-C bindings (Rust, Go, Python, …)

that wrap the DOCA Rivermax C ABI — for the precondition rule, lifecycle, capability, permission, and scheduling rules the wrapper must honor.

Do not load this skill for general DOCA orientation, for installing DOCA itself, for installing the Rivermax SDK or managing the Rivermax license file (those live in the public Rivermax SDK guide reachable through doca-public-knowledge-map), for best-effort packet I/O without timing requirements (use doca-eth directly), or for pure host-side data processing without networking. 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 Rivermax-specific material lives in two companion files:

• CAPABILITIES.md — what DOCA Rivermax can express on this

version and this Rivermax SDK install: the Rivermax-as-hard-dependency rule, the receive-only doca_rmax_in_stream object model, the capability-query surface (doca_rmax_get_*_supported), the Rivermax error taxonomy (mapped onto the cross-library DOCA_ERROR_* set, with Rivermax-specific causes called out per row), the observability surface (per-stream progress engine events, capability snapshots, Rivermax-side license + driver state), and the safety policy that gates the Rivermax-SDK-present / license-present / device-access / scheduling-discipline preconditions.

• TASKS.md — step-by-step workflows for the six in-scope

Rivermax verbs: configure, build, modify, run, test, debug. Plus a Deferred task verbs block that points out-of-scope questions (installing Rivermax, managing the license, programming steering, programming the underlying queue) 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 is already installed at the standard location, the NVIDIA Rivermax SDK is installed at its expected location with a valid license, and the user has the privileges their public install profile expects (typically sudo or mlnx-group membership to open a doca_dev against a port). It does not cover installing DOCA — that path goes through doca-setup. It does not cover installing Rivermax or its license — that path goes through the public Rivermax SDK guide reachable through 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 Rivermax application source code, in any

language. The verified Rivermax source code is the shipped C samples at /opt/mellanox/doca/samples/doca_rmax/<name>/. 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 Rivermax-specific overrides in TASKS.md ## 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, where pkg-config --modversion doca-rmax is the source of truth.

• Quoted Rivermax symbol names beyond the public family

pattern (doca_rmax_get_*_supported for capability discovery, receive-only doca_rmax_in_stream session objects driven by the standard DOCA Core context lifecycle). Exact Rivermax symbol names are install-bound and Rivermax-SDK-version- bound; the agent should read them from the installed headers at $(pkg-config --variable=includedir doca-common) and from the public DOCA Rivermax guide rather than rely on agent memory.

• 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.md first to confirm the user's question is

in scope and that the Rivermax-SDK + license precondition has been considered.

1. For the Rivermax capability matrix, the receive-only input

stream model, capability-query rules, error taxonomy, observability, and safety policy, see CAPABILITIES.md.

1. For step-by-step workflows — configure, build, modify,

run, test, debug — see TASKS.md.

Both companion files cross-link to each other, doca-version for the canonical DOCA version-handling rules (Rivermax adds a Rivermax-SDK- version axis on top), doca-eth for the queue surface that carries the packets, doca-flow for the steering side that decides which packets land on which queue, and doca-public-knowledge-map whenever the right answer is "look it up in the public Rivermax SDK guide or the installed package layout" rather than "Rivermax-integration-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 Rivermax URL slug is DOCA-Rivermax; the public Rivermax SDK guide (separate product) is reachable from the same routing table when the user asks how to install Rivermax or its license.

• doca-setup — env preparation,

install verification, port-state checks (devlink dev show, ip link), permission and group-membership requirements for opening a doca_dev. This skill assumes its preconditions are satisfied; the Rivermax-SDK + license preconditions are layered on top.

• doca-version — canonical

DOCA version-handling rules. This skill's ## Version compatibility cross-links the four-way match rule and adds the Rivermax-specific overlay (Rivermax SDK version is a second axis; the capability set on this host is the intersection of DOCA-side cap-query results and Rivermax-side capabilities).

• doca-structured-tools-contract —

the bundle's structured-tools precedence rule (detect / prefer / fall back / report). The Command appendix in TASKS.md 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 Rivermax specifics on top.

• doca-eth — the queue surface

that carries the packets a Rivermax stream produces or consumes. DOCA Rivermax does not program the underlying queue itself; it integrates with the queue programmed via doca-eth. The two skills' lifecycles are independent.

• doca-flow — the steering

surface that decides which packets land on which queue. DOCA Rivermax does not program steering itself; an empty Rivermax input stream almost always means a missing or wrong Flow rule (or a missing Rivermax license), not a Rivermax bug.

• doca-debug — the

cross-cutting debug ladder (install / version / build / link / runtime / program / driver). Rivermax-specific debug (license precondition gaps, stream-type / packet-rate capability mismatches, scheduling-discipline jitter symptoms) overlays on top of that ladder.