|WARNING| [v2] net/i40e: add IEEE1588 handling to AVX vector paths

[dpdklab at iol.unh.edu]

Test-Label: ai-code-review
Test-Status: WARNING
https://dpdk.org/patch/171705

_AI Code Review_

=== Patch Review: series.patch (via Claude) ===
Review date: 2026-10-19

# DPDK Patch Review

## ERRORS

None identified.

## WARNINGS

### Missing Release Notes

This patch adds IEEE1588 support to AVX2/AVX512 vector Rx paths, which is a significant new feature for users relying on PTP timestamping. This change should be documented in the release notes under the i40e PMD section.

**Suggested fix:**
Add an entry to `doc/guides/rel_notes/release_26_11.rst` (or the appropriate current release file):

```rst
* **Updated net/i40e driver.**

  * Added IEEE1588 PTP timestamp support to AVX2 and AVX512 vector Rx paths.
```

### Missing Feature Matrix Update

The patch enables IEEE1588 support in vector paths, which changes the conditions under which the feature is available. The PMD features matrix should be updated to reflect that IEEE1588 now works with vector Rx.

**Suggested fix:**
Verify and potentially update `doc/guides/nics/features/i40e.ini` to ensure the IEEE1588 feature documentation accurately reflects the new vector path support.

## INFO

### Code Quality Notes

The implementation correctly follows the existing FDIR pattern for extracting per-packet metadata in the vector paths. The approach is sound:

1. Builds flags from already-loaded descriptor status bits (no extra reads)
2. Handles the timestamp index field with per-packet stores (unavoidable, same as FDIR ID)
3. Correctly propagates the `timesync` field in the scatter path (`rx.h`)

The architecture-specific conditional compilation logic is correctly structured, allowing IEEE1588 on x86 vector paths while falling back to scalar on other architectures.

Review-Result: WARNING