Doca Comm Channel Admin

---
license: Apache-2.0
name: doca-comm-channel-admin
description: >
  Use this skill to enumerate host↔DPU DOCA comch (formerly
  Comm Channel) servers and connections via the shipped
  doca_comm_channel_admin binary — listing comch-capable
  devices and decoding the per-device server / connection
  table (server name, PID, in-use / max, PCIe address). The
  shipped binary is a SINGLE-SHOT SCAN-AND-PRINT tool with no
  registered arguments — NO list / inspect / drain / restart
  subcommands; one inventory pass over every comch-capable
  doca_dev on this side. Channel reset / drain / restart go to
  doca-comch (program side), doca-setup / doca-hardware-safety
  (driver reload), or BFB / RShim — NOT to this binary.
  Trigger on phrasings like "list comch servers", "which
  channels are active on this BlueField", or "verify admin
  tool sees same channel as program." Refuse and route
  elsewhere for the comch programming API, library install,
  protocol design, channel reset, or general orientation.
metadata:
  kind: tool
compatibility: >
  Requires DOCA SDK installed at /opt/mellanox/doca on Linux
  (Ubuntu 22.04/24.04 or RHEL/SLES) with the Comm Channel tooling
  subpackage so the CLI is present under
  /opt/mellanox/doca/tools/. Runs from either the x86/Arm host or
  the BlueField Arm side; a live host↔DPU comch channel created
  via the doca-comch library is needed for non-empty tables.
---

# DOCA Comm Channel Admin Tool

> **Actual binary contract.** `doca_comm_channel_admin` is one
> zero-application-argument, read-only scan-and-print operation.
> It scans every comch-capable `doca_dev` on the current side via
> `resourcedump` (MFT) and prints SERVERS and CONNECTIONS tables.
> It has no list, inspect, device-scope, drain, restart, or other
> application operation. This skill does not retain conceptual
> workflows under invented command names.

**Where to start:** This is a tool skill for invoking the DOCA Comm
Channel Admin Tool — the **read-only inventory** CLI counterpart
to the [`doca-comch`](../../libs/doca-comch/SKILL.md) library. The
shipped `doca_comm_channel_admin` binary takes **no arguments
beyond ARGP defaults** (`--help`, `--version`, `--log-level`,
`--sdk-log-level`, `--json`) and performs **one inventory pass**
per invocation: it walks every `doca_dev` on this side, filters
to comch-capable devices, shells out to `resourcedump` (MFT) on
each, and prints two ASCII tables (SERVERS and CONNECTIONS).
There is no `list` subcommand, no `inspect` subcommand, no
`drain` flag, and no `restart` flag — those are not part of the
tool's surface. Open [`TASKS.md`](TASKS.md) and start at
[`## run`](TASKS.md#run) for the single-shot invocation, or
[`## debug`](TASKS.md#debug) when the user reports the tool sees
a different channel set than the program. Open
[`CAPABILITIES.md`](CAPABILITIES.md) when the question is *what
the printed tables actually mean* and *what is not in this
tool's scope*. If the user has not installed DOCA yet, route to
[`doca-setup`](../../doca-setup/SKILL.md) first; if the user
needs MFT (`resourcedump` on `PATH` with the privilege documented
for the installed release), `doca-setup` + `doca-public-knowledge-map`
cover that. If the user is holding pre-2.5 docs that mention
"Comm Channel", route to
[`doca-comch CAPABILITIES.md ## Version compatibility`](../../libs/doca-comch/CAPABILITIES.md#version-compatibility)
for the rename rule. If the user wants to *change* channel
state, route to the program-side
reconnect lifecycle in [`doca-comch`](../../libs/doca-comch/SKILL.md)
or to BlueField mode / driver reload in
[`doca-setup`](../../doca-setup/SKILL.md) +
[`doca-hardware-safety`](../../doca-hardware-safety/SKILL.md) — **not**
to this tool.

## Example questions this skill answers well

The CLASSES of admin-tool questions this skill is built to answer,
each with one worked example. The class is the load-bearing piece;
the worked example is one instance.

- **"Which comch servers and connections are currently visible?"** —
  worked example: *"print every server and connection row visible
  on this side"*. Answered by the scan-and-print surface in
  [`CAPABILITIES.md ## Capabilities and modes`](CAPABILITIES.md#capabilities-and-modes)
  + the single invocation in
  [`TASKS.md ## run`](TASKS.md#run).
- **"What does the tool report for this server or connection?"** —
  locate the matching row in the SERVERS or CONNECTIONS table;
  there is no second per-channel query. Answered by
  [`CAPABILITIES.md ## Capabilities and modes`](CAPABILITIES.md#capabilities-and-modes)
  + [`TASKS.md ## run`](TASKS.md#run).
- **"How do I know the admin tool's view matches what my Comch
  program sees?"** — worked example: *"the program reports
  CONNECTED but the admin tool lists zero channels"*. Answered by
  the cross-checking pattern in
  [`TASKS.md ## test`](TASKS.md#test) and the representor-binding
  layer in
  [`CAPABILITIES.md ## Error taxonomy`](CAPABILITIES.md#error-taxonomy).
- **"Is this admin tool on my installed DOCA version, and does it
  match the comch library version?"** — worked example: *"is the
  tool available on DOCA 2.4"*. Answered by the overlay in
  [`CAPABILITIES.md ## Version compatibility`](CAPABILITIES.md#version-compatibility),
  which redirects to the canonical
  [`doca-version`](../../doca-version/SKILL.md) rules and adds the
  Comm Channel Admin Tool specifics.
- **"The tool prints nothing — is the install broken or is there
  genuinely no channel?"** — worked example: *"`list` returned an
  empty result on a host with a known-good Comch client"*.
  Answered by the empty-output interpretation rules in
  [`TASKS.md ## debug`](TASKS.md#debug) +
  [`CAPABILITIES.md ## Error taxonomy`](CAPABILITIES.md#error-taxonomy).

## Audience

This skill serves **external operators and AI agents who need to
inventory a host-DPU comch channel from the outside**
— after the [`doca-comch`](../../libs/doca-comch/SKILL.md) library
has been used to create the channel from a program. Concretely:

- A platform operator who runs a Comch-using service on BlueField
  and needs to confirm the channel is healthy before declaring the
  service ready.
- A developer of a Comch consumer who sees `DOCA_ERROR_AGAIN` or a
  silent stall on the program side and wants to read the channel's
  state from outside the program rather than guessing.
- An AI agent capturing the external server/connection rows before
  recommending a program-side code or lifecycle change.

It is **not** for users debugging the admin tool itself, **not** a
substitute for the live public DOCA Comm Channel Admin Tool guide,
and **not** the right place for users learning the comch API —
that audience belongs in
[`doca-comch`](../../libs/doca-comch/SKILL.md).

The tool is shipped as a CLI binary under
`/opt/mellanox/doca/tools/`, not a library you link against. The
skill uses the same `kind: tool` three-file shape as the rest of
the bundle so the agent's task-verb contract
(`configure / build / modify / run / test / debug`) is uniform
across libraries, services, and tools.

## When to load this skill

Load this skill when the user is — or the agent needs to — invoke
the DOCA Comm Channel Admin Tool on a real host or BlueField Arm
with DOCA installed (or inside the public NGC DOCA container with
the right device passthrough). Concretely:

- Listing currently active comch channels on a host or DPU.
- Reading the row for one named server or connection from the
  complete zero-argument scan.
- Cross-checking the admin tool's view against the program-side
  connection callback state when the two appear to disagree.
- Capturing a side-effect-free channel snapshot as prerequisite
  evidence for a later debug session that crosses program /
  channel / driver layers.

Do **not** load this skill for general DOCA orientation, the comch
programming API, library install, or comch protocol design. For
those, route to
[`doca-public-knowledge-map`](../../doca-public-knowledge-map/SKILL.md),
[`doca-comch`](../../libs/doca-comch/SKILL.md), or
[`doca-setup`](../../doca-setup/SKILL.md).

## What this skill provides

This is a **thin loader**. Substantive material lives in two
companion files:

- `CAPABILITIES.md` — what the Comm Channel Admin Tool reports:
  the two read-only tables, the version-availability overlay
  that redirects to [`doca-version`](../../doca-version/SKILL.md),
  the layered error taxonomy (tool-not-installed / device-binding
  / channel-discovery / channel-state-stuck / permission /
  version / cross-cutting), the tool's role as an observability
  primitive for [`doca-comch`](../../libs/doca-comch/SKILL.md)
  debug sessions, and the read-only safety policy.
- `TASKS.md` — step-by-step workflows for the in-scope task verbs:
  `configure` (route to install), `build` (route to install),
  `modify` (refuse), `run` (one scan-and-print), `test`
  (cross-check the printed rows), `debug` (the layered
  diagnosis ladder), plus a `Deferred task verbs` block and a
  `Command appendix` that honors the bundle's
  [`doca-structured-tools-contract`](../../doca-structured-tools-contract/SKILL.md)
  preamble.

The skill assumes a host or BlueField where DOCA is already
installed (or the public NGC DOCA container is running with the
right device passthrough) and the operator has whatever privileges
the public DOCA Comm Channel Admin Tool guide requires.

## What this skill deliberately does not ship

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

- **Verbatim flag inventories, subcommand names, or output column
  names.** The public DOCA Comm Channel Admin Tool guide on
  `docs.nvidia.com` and the installed `--help` on the user's
  version are the joint source of truth; copying them here pins
  the skill to one release and silently rots when the tool
  evolves. The skill routes the agent at those sources instead.
- **Pre-baked example output.** Output is install-, version-, and
  channel-state-specific. A captured example will mislead an
  operator on a different platform / state.
- **Wrappers, parsers, or scripts** in any language that consume
  the admin tool's output. The output format is documented; users
  who want to script against it should read the live guide and
  write the parser against their installed version.
- **A `samples/` or `reference/` subtree.** This is a thin loader
  for a documented CLI; substantive material lives on the public
  page and in `--help`.

## Loading order

1. Read this `SKILL.md` first to confirm the user's question is in
   scope (the user wants to inventory a comch
   channel from the outside, not learn the comch API).
2. **For what the tool reports, version availability, the layered error surface,
   observability, and safety posture, see
   [CAPABILITIES.md](CAPABILITIES.md).**
3. **For the single invocation and cross-check
   workflow — `configure`, `build`, `modify`, `run`, `test`,
   `debug`, plus the `Command appendix` — see
   [TASKS.md](TASKS.md).**

## Related skills

- [`doca-comch`](../../libs/doca-comch/SKILL.md) — the library
  whose channels this tool inventories. Pair them in every
  triage session: the program-side connection callback and the
  admin tool's channel state are the two halves of the same
  picture.
- [`doca-public-knowledge-map`](../../doca-public-knowledge-map/SKILL.md)
  — routing to the public DOCA Comm Channel Admin Tool guide and
  the rest of the public DOCA documentation set.
- [`doca-version`](../../doca-version/SKILL.md) — canonical DOCA
  version-handling rules. The `## Version compatibility` section
  in [`CAPABILITIES.md`](CAPABILITIES.md) is a concise overlay
  that redirects here for the body.
- [`doca-structured-tools-contract`](../../doca-structured-tools-contract/SKILL.md)
  — the bundle's detect → prefer → fall back → report contract for
  structured helper tools. The Command appendix in
  [`TASKS.md`](TASKS.md) honors this contract.
- [`doca-setup`](../../doca-setup/SKILL.md) — env preparation,
  install verification, representor visibility checks, and the
  *I have no install yet* path with the public NGC DOCA
  container. This skill assumes its preconditions are satisfied.
- [`doca-debug`](../../doca-debug/SKILL.md) — the cross-cutting
  debug ladder. The Comm Channel Admin Tool slots in at the
  *runtime* layer as the read-only inventory surface before any
  code change is recommended.