Disable SME on iOS - #433
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… > 0 Apple processors like A18/A19 physically support SME/SME2 in hardware, so hw.optional.arm.FEAT_SME returns true. However, XNU on iOS disables user-mode (EL0) SME execution (arm_sme_version() == 0), causing instructions like SMSTART to fault with EXC_BAD_INSTRUCTION. macOS and iPadOS (e.g. on M4) support and enable user-mode SME, setting hw.optional.arm.sme_max_svl_b > 0. Check hw.optional.arm.sme_max_svl_b > 0 before enabling SME feature flags to ensure SME is only reported when the OS allows user-space execution.
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Check hw.optional.arm.sme_max_svl_b > 0 before enabling SME feature flags to ensure SME is only reported when the OS allows user-space execution.
Fixes #432