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arm64: Move BP hardening and SSBD workaround to CPU_FEAT framework
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Authored by sarah.walker2_arm.com on Oct 15 2025, 12:35 PM.
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Summary

Port the BP hardening and SSBD workaround from cpu_quirks to the
CPU_FEAT framework.

Sponsored by: Arm Ltd

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rG FreeBSD src repository
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The best names I can come up with for a workaround for a missing feature is feat_foo_missing or feat_foo_workaround

sys/arm64/arm64/spec_workaround.c
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I'd like to keep feat_* for architectural features. The closest feature is FEAT_CSV2, however this tells us when the workaround is not needed, so maybe we could come up with something based on that.

The name is used in the hw.feat sysctls & can be used to enable/disable features/workarounds on boot.

165

The appropriate feature here is FEAT_SSBS

This revision is now accepted and ready to land.Oct 16 2025, 2:52 PM