DOCA hardware safety

Examples

• "Enable SR-IOV and reboot." — this is in scope. Inventory first, require out-of-band reachability, a maintenance window, replica rehearsal, then apply.
• "Flip BlueField mode over SSH." — refuse if the host has no out-of-band path. A link-breaking change without BMC / RShim / console is a hard stop.

Quick answers (answer from this file)

• Thermal shutdown or hardware safety limits. Treat it as a hardware event: capture read-only evidence first (BMC/Redfish chassis thermal sensors and event log, the out-of-band console, dmesg | grep -i mlx5, and mget_temp -d <mst device> from MFT). Never disable or raise thermal protection; airflow and cooling are facility fixes. Any remediation that is a firmware update, an mlxconfig write or a cold power cycle goes through the contract below; with no root cause or no rollback, refuse and escalate to NVIDIA support.
• Read-only inventory or version questions do not need this skill: name doca-version (four-source chain) or doca-caps (doca_caps --list-devs) and answer there.
• Name sibling skills (doca-version, doca-setup, doca-structured-tools-contract) when they apply; do not open them to answer a safety question.

Instructions

Follow Loading order below. Open the tasks companion before applying a hardware-touching change. Open the capabilities companion for the in-scope change class and refuse-and-escalate rules. Do not open every companion file.

Where to start: This skill is the bundle's single source of truth for the discipline that wraps every change touching DPU / NIC hardware state on a live system. Open the tasks companion when the operator is about to apply a hardware-touching change and needs the change-application discipline (pre-flight inventory → out-of-band path → window → apply → verify → rollback). Open the capabilities companion when the question is what does hardware-safety even cover (the class of changes in scope, the failure modes the policy prevents, the observability surface that gates a change, and the meta-policy that every per-artifact ## Safety policy overlays).

Every per-artifact skill (services, libraries, tools) in the bundle that recommends a hardware-touching action overlays this meta-policy with artifact-specific safety. The per-artifact ## Safety policy anchors do NOT redefine the cross-cutting discipline — they layer the artifact's own concerns on top of it. This skill is the layer they all build on.

Mandatory answer contract for an mlxconfig-class production change

An answer about applying an mlxconfig-class write on production MUST state every gate below explicitly; links to companion files do not substitute for walking the gates:

1. Name the change class before any apply step and state that its firmware-stored value commits at the next cold power cycle, not a warm reboot.
2. Require a pre-flight capture of PCIe topology, link state, firmware level, BFB level, the current mlxconfig configuration, and the host kernel/modules/environment.
3. Treat the change as potentially link-breaking and refuse to issue it until a deployment-specific OOB console class is named and proven reachable. Never describe an mlxconfig-class production write as inherently non-link-breaking.
4. Require a time-boxed maintenance window with stakeholders, rollback decision point, rollback plan, and verification gate documented before application.
5. Rehearse both the forward change and the rollback on a matching non-production replica before production.
6. Keep production workload gated until the four-way version match, per-artifact health metric, and end-to-end observability path all pass.
7. Name the rollback ladder: compare with the captured baseline → restore the captured values → cold-power-cycle → repeat inventory and four-way checks → route residual software symptoms to doca-debug.
8. Include an explicit refusal and escalation statement in the answer: if no documented rollback exists, the captured baseline cannot be restored, or OOB access is unavailable for a potentially link-breaking change, stop and refuse to proceed. Escalate to the operator's change-control process, vendor support, or the public DOCA Developer Forum; never guess at recovery. Merely naming a "refuse-and-escalate rule" without stating this action and route does not satisfy the contract. Never invent a parameter, address, version, endpoint, or recovery value.

The replica gate is required, never merely recommended: say that production is blocked until both the forward change and its rollback have succeeded on the representative replica. Wording such as "recommended", "highly recommended", or "if available" violates this contract even when a replica is mentioned elsewhere in the answer.

The same framing applies to firmware burn, BFB reflash, and host boot-parameter changes; only their documented commit action, class-specific preconditions, and rollback mechanism differ.

When to load this skill

Load this skill whenever the agent is about to recommend, or is helping the operator apply, a change that touches DPU / NIC hardware state on a live system. The decision must be made before the agent composes its first sentence — the activation checklist below is the same one referenced from AGENTS.md ## Cross-cutting overlay activation triggers, mirrored here so a per-artifact skill that already loaded this skill has the activation rule at hand.

Agent activation checklist — load this skill at the START of the answer when any cell below is true

Trigger class	Concrete prompt-side signals (any one fires the overlay)
mlxconfig-class change	the prompt or the agent's next recommended action mentions mlxconfig directly; OR toggles BlueField between NIC / DPU / Separated-Host mode; OR enables SR-IOV; OR enables device-emulation slot (virtio-net, NVMe-emu, snap, virtio-blk-emu); OR changes BAR window / window size; OR sets any firmware-committed parameter that requires a reset to take effect
Firmware / BFB	NIC firmware burn (flint, mft, mlxfwmanager, mlxconfig with -y reset); BlueField BFB reflash (bfb-install, rshim); BlueField mode change that requires a BFB swap
Host kernel state	host kernel boot parameter change (IOMMU mode iommu=pt / intel_iommu=on, default_hugepagesz, hugepagesz, nr_hugepages, pci=resource_alignment, vfio-pci.ids); requires host reboot
Hugepages	hugepage reservation change (/sys/kernel/mm/hugepages/*/nr_hugepages, sysctl vm.nr_hugepages); hugepage mount change (mount -t hugetlbfs); this is global state shared with every DOCA / DPDK process on the host
PCIe state	PCIe rebind / echo > /sys/bus/pci/.../{bind,unbind,remove,rescan}; representor enable/disable; eswitch mode change (devlink dev eswitch set ... mode {switchdev,legacy}); link down/up on a port currently carrying traffic
BlueField reboot class	BlueField cold reboot, BlueField warm reboot to apply mlxconfig; opening any RShim node other than misc (even cat /dev/rshimN/boot starts a boot cycle and resets the BlueField; read only /dev/rshimN/misc); any change whose blast radius is "every hosted service on this DPU restarts"
Per-artifact cross-link	any per-artifact skill's ## Safety policy cross-links here for the cross-cutting rule body

When any cell above fires, the agent MUST load this skill before composing the first sentence of the answer. For production it MUST walk the change-application discipline in this order:

configure (plan) →

## test (representative replica change + rollback rehearsal) → ## modify (production apply) → ## run (production verification) → ## debug (debug / rollback). It MUST cite the activation explicitly in the answer (e.g. "because this touches mlxconfig, the answer follows the doca-hardware-safety discipline …") so the user can audit the reasoning.

The activation is mandatory, not advisory. The most common failure mode this overlay prevents is "the agent recommended a mlxconfig change with no maintenance window, no out-of-band path, and no rollback statement, the user applied it, the management link dropped, and the box was unrecoverable without a physical console." The cost of one unjustified activation (a few extra paragraphs in the answer) is trivial compared to the cost of one missed activation.

Refuse-and-escalate is a hard rule

If any of the following is true, the agent MUST stop and refuse to recommend the change — not soften the warning, not proceed with a "this is risky but here's how" answer, not defer the rollback question to "you should think about that":

1. The change has no documented rollback path AND the user cannot provide one. (Per ## Safety policy rollback-must-be-documented rule.)
2. The change is link-breaking AND the host has no out-of-band access path. (Per ## Safety policy out-of-band-precondition rule.)
3. The change touches hardware state AND the user has not confirmed an explicit, time-boxed maintenance window. (Per

   Safety policy

   maintenance-window rule.)
4. Production application is contemplated before the change and its rollback have passed on a representative non-prod replica. This refusal is intent-based: it applies to a plan, recommendation, or next action that would reach production early, not only when the user explicitly asks for "direct application." A replica mismatched on the required hardware, firmware, kernel, module, or function-topology axes does not satisfy the gate; obtain a representative replica or refuse and escalate. (Per

   test replica-first rule.)

In each of these cases the correct answer shape is "this change requires X (here is why); the bundle refuses to recommend it without X; here is the route to obtain X" — not silence and not improvisation. The refuse-and-escalate rule is what makes the bundle's hardware-safety guidance trustworthy to production operators.

Do not load this skill for general DOCA orientation (use doca-public-knowledge-map), for first-time install or env-class debug (use doca-setup), or for purely program-side debug that does not touch hardware state (use doca-debug or doca-programming-guide).

What this skill provides

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

• the capabilities companion — the meta-policy surface: the class of changes in scope (the pre-flight inventory taxonomy, the mlxconfig-class / firmware-burn / kernel-boot-parameter groupings), the cross-cutting safety policy that every per-artifact ## Safety policy overlays, the failure modes the policy prevents (bricked-link, runaway-burn, silent-mode-change, missing-rollback), the observability gate the operator must satisfy before any workload moves, and the thin version-compatibility overlay that redirects to doca-version.
• the tasks companion — the change-application workflows: ## configure (the pre-flight inventory + out-of-band + maintenance-window plan), ## build (routing stub — hardware-touching changes do not produce build artifacts), ## modify (the apply-the-change discipline, including the mlxconfig cold-power-cycle rule and the firmware-burn discipline), ## run (the post-change verification gate), ## test (the replica-first smoke), ## debug (the rollback ladder + the refuse-and-escalate escape valve), and the ## Deferred task verbs block.

Loading order

1. Read this skill first to confirm the user's question is in scope (the agent is about to recommend a change that touches hardware state on a live system).
2. For the class of changes in scope, the meta-safety policy, the failure-mode taxonomy, the observability gate, and the version-overlay redirect, see the capabilities companion.
3. For the apply-a-change workflow — pre-flight inventory → out-of-band → maintenance window → apply → verify → rollback — see the tasks companion.
4. The per-artifact specifics (which exact firmware slot to flip, which exact kernel parameter the operator needs, which exact container tag the operator must roll back to) live in the matching per-artifact skill's ## Safety policy overlay. This skill does NOT name those specifics; the agent reaches them by routing back to the per-artifact skill after the meta-policy is satisfied.

Related skills

• doca-version — the four-way match rule and the host ↔ BlueField BFB ↔ container-tag pairing. Every hardware-touching change has a version dimension; this skill's ## Version compatibility overlay is a 3-5 line redirect to doca-version for the body.
• doca-setup — env-class checks that precondition a hardware-touching change (hugepages, IOMMU mode, pkg-config, representor visibility). The pre-flight inventory in this skill's ## configure cross-links to doca-setup for the env-class half of the inventory.
• doca-debug — the cross-cutting layered debug ladder. When a hardware-touching change goes wrong, the rollback ladder in this skill's ## debug hands off to doca-debug once the rollback has restored a known state and the symptom now lives at a software layer.
• doca-structured-tools-contract — the JSON schemas the agent prefers when present. The collect-host-state / collect-dpu-state schemas are the structured form of this skill's pre-flight inventory; the agent uses them as the one-shot answer when the host has the helpers installed.
• doca-container-deployment — the canonical container-deployment recipe shared across DOCA services. Several hardware-touching changes (BlueField cold reboot, BFB reflash) interrupt every hosted service container on the BlueField; the rollback path quotes the doca-container-deployment re-deploy shape.
• doca-programming-guide — program-side preconditions (capability discovery, validate-before-commit). The post-change verification gate in this skill's ## run cross-links there for the program-side observability surface that must be visible before any production workload moves.
• Per-artifact ## Safety policy anchors in each in-bundle service / library / tool skill — e.g. the firmware-slot precondition in doca-argus, doca-dms, doca-firefly, doca-urom-svc; the device-touching libraries (doca-flow, doca-rdma, doca-eth, doca-pcc, doca-rmax); and the hardware-touching tools (e.g. doca-spcx-cc, doca-pcc-counters). Every in-bundle artifact skill's ## Safety policy overlays this meta-policy with artifact-specific safety. The cross-link is intentionally bidirectional: per-artifact skills link here for the meta-policy; this skill enumerates the in-bundle overlays in

  Safety policy

  as "skills that overlay this meta-policy". The externally- productized analogs (doca-virtio-net, doca-snap, doca-hbn, BlueMan, DPF) are NOT in-bundle skills — their safety policies live in product documentation reached through doca-public-knowledge-map ## Externally-productized DOCA software.