Messages in this thread Patch in this message | | | From | "Fenghua Yu" <> | Subject | [PATCH 02/15] x86/xsaves: Add kernel parameter to disable xsaves/xrstors | Date | Mon, 26 May 2014 10:01:09 -0700 |
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From: Fenghua Yu <fenghua.yu@intel.com>
Add kernel parameter noxsaves to disable xsaves/xrstors feature.
Add kernel parameter noxsaveopt in doc.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> --- Documentation/kernel-parameters.txt | 9 +++++++++ arch/x86/kernel/cpu/common.c | 8 ++++++++ 2 files changed, 17 insertions(+)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4384217..8541752 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2124,6 +2124,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. and restore using xsave. The kernel will fallback to enabling legacy floating-point and sse state. + noxsaveopt [X86] Disables x86 extended register state context + switch using xsaveopt. The kernel wil fallback to use + not optimized xsave to do context switch. + + noxsaves [X86] Disables x86 extended register state context + switch and save/restore compacted formated xsave + area using xsaves. Then the kernel uses standard + xsave area for xstate. + eagerfpu= [X86] on enable eager fpu restore off disable eager fpu restore diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index a135239..409f47c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -146,6 +146,7 @@ static int __init x86_xsave_setup(char *s) { setup_clear_cpu_cap(X86_FEATURE_XSAVE); setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); + setup_clear_cpu_cap(X86_FEATURE_XSAVES); setup_clear_cpu_cap(X86_FEATURE_AVX); setup_clear_cpu_cap(X86_FEATURE_AVX2); return 1; @@ -159,6 +160,13 @@ static int __init x86_xsaveopt_setup(char *s) } __setup("noxsaveopt", x86_xsaveopt_setup); +static int __init x86_xsaves_setup(char *s) +{ + setup_clear_cpu_cap(X86_FEATURE_XSAVES); + return 1; +} +__setup("noxsaves", x86_xsaves_setup); + #ifdef CONFIG_X86_32 static int cachesize_override = -1; static int disable_x86_serial_nr = 1; -- 1.8.1.2
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