x86/fpu: Make XSAVE check the base CPUID features before enabling
authorAndi Kleen <ak@linux.intel.com>
Fri, 13 Oct 2017 21:56:44 +0000 (14:56 -0700)
committerIngo Molnar <mingo@kernel.org>
Tue, 17 Oct 2017 15:14:57 +0000 (17:14 +0200)
commitccb18db2ab9d923df07e7495123fe5fb02329713
tree9a92ec9bf8e676cdffdb8ba91bc906d228b67813
parent0c2a3913d6f50503f7c59d83a6219e39508cc898
x86/fpu: Make XSAVE check the base CPUID features before enabling

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>
arch/x86/kernel/fpu/xstate.c