diff options
| author | yu-cheng yu <[email protected]> | 2016-01-06 14:24:52 -0800 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2016-01-12 11:51:21 +0100 |
| commit | eb7c5f872e697b0aebd846cf3a3328d71e9decb2 (patch) | |
| tree | 51f15308a9124ba9cbe52d03aa5d2c99bfedcdda | |
| 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 <[email protected]>
Reviewed-by: Dave Hansen <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Quentin Casasnovas <[email protected]>
Cc: Ravi V. Shankar <[email protected]>
Cc: Sai Praneeth Prakhya <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: yu-cheng yu <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -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); } /* |