Messages in this thread | | | Date | Thu, 3 Nov 2022 14:30:56 +0100 | Subject | Re: [PATCH v2 1/5] perf/x86/intel/lbr: use setup_clear_cpu_cap instead of clear_cpu_cap | From | Paolo Bonzini <> |
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On 11/2/22 15:27, Elliott, Robert (Servers) wrote: > > 3. Similarly, modules using X86_FEATURE_XMM2 probably need to > check XFEATURE_MASK_SSE: > > Currently checking XSAVE SSE: > aegis128-aesni-glue > > Current not checking XSAVE SSE: > nhpoly1305-sse2_glue > serpent_sse2_glue
These should check boot_cpu_has(X86_FEATURE_FXSR). Checking XFEATURE_MASK_SSE will fail on systems without XSAVE, because fpu_kernel_cfg.max_features is zero there (see fpu__init_system_xstate() in arch/x86/kernel/fpu/xstate.c).
It happens to work for aegis128-aesni-glue because AES instructions only exist on new-enough parts, but it should probably be changed as well.
Paolo
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