x86/fpu: Make XSAVE check the base CPUID features before enabling

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commit ccb18db2ab upstream.

Before enabling XSAVE, not only check the XSAVE specific CPUID bits,
but also the base CPUID features of the respective XSAVE feature.
This allows to disable individual XSAVE states using the existing
clearcpuid= option, which can be useful for performance testing
and debugging, and also in general avoids inconsistencies.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20171013215645.23166-5-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Andi Kleen 2017-10-13 14:56:44 -07:00 • committed by Greg Kroah-Hartman

parent f01d7efac7

commit 0e7127aa76

1 changed files with 23 additions and 0 deletions

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arch/x86/kernel/fpu/xstate.c

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