Commit-ID: eb7c5f872e697b0aebd846cf3a3328d71e9decb2 Gitweb: http://git.kernel.org/tip/eb7c5f872e697b0aebd846cf3a3328d71e9decb2 Author: yu-cheng yu <yu-cheng.yu@xxxxxxxxx> AuthorDate: Wed, 6 Jan 2016 14:24:52 -0800 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 12 Jan 2016 11:51:21 +0100 x86/fpu: Disable XGETBV1 when no XSAVE 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.yu@xxxxxxxxx> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Quentin Casasnovas <quentin.casasnovas@xxxxxxxxxx> Cc: Ravi V. Shankar <ravi.v.shankar@xxxxxxxxx> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: yu-cheng yu <yu-cheng.yu@xxxxxxxxx> Link: http://lkml.kernel.org/r/1452119094-7252-3-git-send-email-yu-cheng.yu@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- 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 40f1002..d489f27 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); } /* -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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