(06) dpdk: device configuration and lifecycle

[daniel-noland]

I know that the coverage report for this is empty.

Fixing that in a practical way requires n-vm. That is fine, it just arrives later in the stack. I may be able to pull those tests back here. Still working on that. That said, the logic itself is ready for review

[coderabbitai]

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• Run ID: 6afa4861-d959-4325-adb8-ffd543528c43

📥 Commits

Reviewing files that changed from the base of the PR and between 113667a and 2533d80.

📒 Files selected for processing (3)

• dpdk/src/dev.rs
• dpdk/src/queue/rx.rs
• dpdk/src/queue/tx.rs

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📝 Walkthrough

Walkthrough

Device configuration now supports MTU limits and advertised LRO sizing. Device lifecycle transitions use stopped and started typestates. RX and TX queue setup adjust descriptor counts through DPDK before configuring each queue.

Changes

Device configuration and lifecycle

Layer / File(s)	Summary
Device configuration and capabilities dpdk/src/dev.rs	DevConfig accepts an optional MTU, rejects explicit values outside a valid advertised range, and clamps the default MTU to that range. Device RX configuration uses the resolved MTU and advertised maximum LRO packet size. DevInfo exposes queue offload capabilities and MTU limits.
Typestate lifecycle transitions dpdk/src/dev.rs	Dev uses Stopped and Started typestates. Start and stop consume the device and return it in its unchanged state on failure. Drop behavior depends on the device state.

Queue descriptor adjustment

Layer / File(s)	Summary
Adjust descriptors before queue setup dpdk/src/queue/rx.rs, dpdk/src/queue/tx.rs	RX and TX queue setup pass configured descriptor counts to DPDK for adjustment, then use the adjusted count. RX returns adjustment errors through ConfigFailure::check; TX maps allocation errors to NoMemory and other errors to Unexpected. Both configurations document that zero thresholds select PMD defaults.

Priority: ➖ Normal

Merge Risk: ⚪ Minimal · up to 2533d

This change adds typed stopped and started states, MTU validation, LRO sizing from device limits, and descriptor-limit adjustment for DPDK devices. No concrete defects were identified, and the change appears ready to merge.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 18 functions across 3 files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly describes the main changes to DPDK device configuration and lifecycle.
Description check	✅ Passed	The description discusses test coverage and review status for the changeset, so it is related to the pull request.

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 112 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
dpdk/src/dev.rs	0.00%	86 Missing ⚠️
dpdk/src/queue/rx.rs	0.00%	13 Missing ⚠️
dpdk/src/queue/tx.rs	0.00%	13 Missing ⚠️

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