> From: Paolo Bonzini <pbonzini@xxxxxxxxxx> ... > (2) in particular holds even on bare metal. The kernel bug here is that > X86_FEATURE_AVX only tells you if the instructions are _present_, not if > they are _usable_. Indeed, the XCR0 check is present for all other > files in arch/x86/crypto, either instead or in addition to > boot_cpu_has(X86_FEATURE_AVX). > > Maxim had sent a patch about a year ago to do it in aesni-intel-glue.c > but Dave told him to fix the dependencies instead > (https://lore.kernel.org/all/20211103124614.499580-1- > mlevitsk@xxxxxxxxxx/). > What do you think of applying that patch instead? Most of the x86 crypto modules using X86_FEATURE_AVX do check cpu_has_xfeatures(XFEATURE_MASK_YMM, ... so it's probably prudent to add it to the rest (or remove it everywhere if it is not needed). 1. Currently checking XSAVE YMM: aria_aesni_avx_glue blake2s-glue camellia_aesni_avx2_glue camellia_aesni_avx_glue cast5_avx_glue cast6_avx_glue chacha_glue poly1305_glue serpent_avx2_glue serpent_avx_glue sha1_ssse3_glue sha256_ssse3_glue sha512_ssse3_glue sm3_avx_glue sm4_aesni_avx2_glue sm4_aesni_avx_glue twofish_avx_glue Currently not checking XSAVE YMM: aesni-intel_glue curve25519-x86_64 nhpoly1305-avx2-glue polyval-clmulni_glue 2. Similarly, modules using X86_FEATURE_AVX512F, X86_FEATURE_AVXX512VL and/or X86_FEATURE_AVX512BW probably need to check XFEATURE_MASK_AVX512: Currently checking XSAVE AVX512: blake2s-glue poly1305_glue Currently not checking XSAVE AVX512: chacha_glue 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
