diff options
| author | yu-cheng yu <yu-cheng.yu@intel.com> | 2016-01-06 14:24:52 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-01-12 11:51:21 +0100 |
| commit | eb7c5f872e697b0aebd846cf3a3328d71e9decb2 (patch) | |
| tree | 51f15308a9124ba9cbe52d03aa5d2c99bfedcdda /arch/x86/kernel/fpu | |
| parent | 4f81cbafcce2c603db7865e9d0e461f7947d77d4 (diff) | |
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@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/1452119094-7252-3-git-send-email-yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/fpu')
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 40f100285984..d489f277a8a0 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); } /* |