When "noxsave" is given as a command-line input, the kernel should disable XGETBV1. This issue currently does not cause any actual problems. XGETBV1 is only useful if we have something using the 'init optimization' (i.e. xsaveopt, xsaves). We already clear both of those in fpu__xstate_clear_all_cpu_caps(). But this is good for completeness.
Signed-off-by: Yu-cheng Yu <yu-cheng...@intel.com> Reviewed-by: Dave Hansen <dave.han...@intel.com> Cc: x...@kernel.org Cc: H. Peter Anvin <h...@zytor.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Borislav Petkov <b...@suse.de> Cc: Sai Praneeth Prakhya <sai.praneeth.prak...@intel.com> Cc: Ravi V. Shankar <ravi.v.shan...@intel.com> Cc: Fenghua Yu <fenghua...@intel.com> --- arch/x86/kernel/fpu/xstate.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 70fc312..b27d3b6 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -52,6 +52,7 @@ void fpu__xstate_clear_all_cpu_caps(void) setup_clear_cpu_cap(X86_FEATURE_AVX512ER); setup_clear_cpu_cap(X86_FEATURE_AVX512CD); setup_clear_cpu_cap(X86_FEATURE_MPX); + setup_clear_cpu_cap(X86_FEATURE_XGETBV1); } /* -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/