sst: compile on non-amd64 architectures

[TonyxSun]

Summary

The SST package generates Linux ioctl request declarations in an amd64-only Go file. Importers therefore fail to compile on other architectures before SST support detection can report that the Intel-only feature is unavailable.

This change generates the ISST UAPI declarations into a single architecture-independent file from the Linux/amd64 ABI source. They are fixed-width structs and constants, so they compile everywhere. Device detection and the real ioctl transport remain amd64-only. Non-amd64 builds report SST as unsupported and reject ioctl calls before accessing the device path. It does not emulate SST or enable Intel SST features on ARM.

Native arm64 CI now runs the same make verify and make test targets as amd64. This unblocks ARM64 consumers such as containers/nri-plugins in containers/nri-plugins#461.

Test plan

• make verify
• make test in a Linux/arm64 container
• CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build ./...
• CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build ./...
• go test ./pkg/sst/... on Linux/amd64 and Linux/arm64
• Fork Verify workflow, including the native arm64 job

[Copilot]

Pull request overview

Enables SST importers to compile on non-amd64 architectures while keeping SST hardware access amd64-only.

Changes:

• Splits SST detection and ioctl transport by architecture.
• Generates compile-only non-amd64 ABI declarations.
• Adds amd64/arm64 tests and native arm64 CI coverage.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pkg/sst/platform.go	Moves architecture-specific detection out of shared code.
pkg/sst/platform_amd64.go	Retains device-based SST detection on amd64.
pkg/sst/platform_nonamd64.go	Reports SST unsupported on non-amd64.
pkg/sst/platform_amd64_test.go	Tests amd64 device detection.
pkg/sst/platform_nonamd64_test.go	Tests non-amd64 rejection.
pkg/sst/internal/isst/isst.go	Removes shared ioctl transport.
pkg/sst/internal/isst/ioctl_amd64.go	Provides the real amd64 ioctl transport.
pkg/sst/internal/isst/ioctl_nonamd64.go	Rejects non-amd64 ioctl requests.
pkg/sst/internal/isst/ioctl_nonamd64_test.go	Tests deterministic ioctl rejection.
pkg/sst/internal/isst/_types_amd64.go	Defines the shared Linux/amd64 generation source.
pkg/sst/internal/isst/types_nonamd64.go	Supplies compile-only ABI declarations.
pkg/sst/internal/isst/gen_types.sh	Generates both architecture outputs.
.github/workflows/verify.yaml	Adds cross-build and native arm64 validation.

Files not reviewed (1)

• pkg/sst/internal/isst/types_nonamd64.go: Generated file

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[TonyxSun]

@klihub this is mostly lift and shift from isst.go and platform.go into platform spcific arch specific src files, and not a lot of change. feel free to review / steer.

[klihub]

/cc @marquiz

[klihub]

@TonyxSun This looks fine to me.

I have one micro-nit regarding the commit message itself: the message body is 423 characters long, formatted as a single line. Could you reformat that to multiple lines with <= 72 characters each.

[TonyxSun]

@klihub done! ty for reminder about convention

[marquiz]

Thanks @TonyxSun for the contribution. Generally looks ok, but some comments below