]> git.baikalelectronics.ru Git - kernel.git/commit
x86/fpu: Disable XGETBV1 when no XSAVE
authoryu-cheng yu <yu-cheng.yu@intel.com>
Wed, 6 Jan 2016 22:24:52 +0000 (14:24 -0800)
committerIngo Molnar <mingo@kernel.org>
Tue, 12 Jan 2016 10:51:21 +0000 (11:51 +0100)
commit2a177fad6fabf0a07582d740d0a02775202de5a1
tree51f15308a9124ba9cbe52d03aa5d2c99bfedcdda
parent7ab1c6a205fc299c8a90700e2acc72b814fb226b
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>
arch/x86/kernel/fpu/xstate.c