The following commit has been merged into the x86/fpu branch of tip: Commit-ID: 70c3f1671b0cbc386b387f1de33b7837e276a195 Gitweb: https://git.kernel.org/tip/70c3f1671b0cbc386b387f1de33b7837e276a195 Author: Chang S. Bae <chang.seok.bae@xxxxxxxxx> AuthorDate: Thu, 21 Oct 2021 15:55:23 -07:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Tue, 26 Oct 2021 10:53:02 +02:00 x86/fpu/xstate: Prepare XSAVE feature table for gaps in state component numbers The kernel checks at boot time which features are available by walking a XSAVE feature table which contains the CPUID feature bit numbers which need to be checked whether a feature is available on a CPU or not. So far the feature numbers have been linear, but AMX will create a gap which the current code cannot handle. Make the table entries explicitly indexed and adjust the loop code accordingly to prepare for that. No functional change. Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Len Brown <len.brown@xxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lore.kernel.org/r/20211021225527.10184-20-chang.seok.bae@xxxxxxxxx --- arch/x86/kernel/fpu/xstate.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index db0bfc2..e3d1898 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -53,18 +53,18 @@ static const char *xfeature_names[] = "unknown xstate feature" , }; -static short xsave_cpuid_features[] __initdata = { - X86_FEATURE_FPU, - X86_FEATURE_XMM, - X86_FEATURE_AVX, - X86_FEATURE_MPX, - X86_FEATURE_MPX, - X86_FEATURE_AVX512F, - X86_FEATURE_AVX512F, - X86_FEATURE_AVX512F, - X86_FEATURE_INTEL_PT, - X86_FEATURE_PKU, - X86_FEATURE_ENQCMD, +static unsigned short xsave_cpuid_features[] __initdata = { + [XFEATURE_FP] = X86_FEATURE_FPU, + [XFEATURE_SSE] = X86_FEATURE_XMM, + [XFEATURE_YMM] = X86_FEATURE_AVX, + [XFEATURE_BNDREGS] = X86_FEATURE_MPX, + [XFEATURE_BNDCSR] = X86_FEATURE_MPX, + [XFEATURE_OPMASK] = X86_FEATURE_AVX512F, + [XFEATURE_ZMM_Hi256] = X86_FEATURE_AVX512F, + [XFEATURE_Hi16_ZMM] = X86_FEATURE_AVX512F, + [XFEATURE_PT_UNIMPLEMENTED_SO_FAR] = X86_FEATURE_INTEL_PT, + [XFEATURE_PKRU] = X86_FEATURE_PKU, + [XFEATURE_PASID] = X86_FEATURE_ENQCMD, }; static unsigned int xstate_offsets[XFEATURE_MAX] __ro_after_init = @@ -809,7 +809,10 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) * Clear XSAVE features that are disabled in the normal CPUID. */ for (i = 0; i < ARRAY_SIZE(xsave_cpuid_features); i++) { - if (!boot_cpu_has(xsave_cpuid_features[i])) + unsigned short cid = xsave_cpuid_features[i]; + + /* Careful: X86_FEATURE_FPU is 0! */ + if ((i != XFEATURE_FP && !cid) || !boot_cpu_has(cid)) fpu_kernel_cfg.max_features &= ~BIT_ULL(i); }
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