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Commit d12a72b8 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
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x86/mm: Add a 'noinvpcid' boot option to turn off INVPCID 



This adds a chicken bit to turn off INVPCID in case something goes
wrong.  It's an early_param() because we do TLB flushes before we
parse __setup() parameters.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/f586317ed1bc2b87aee652267e515b90051af385.1454096309.git.luto@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 060a402a

Documentation/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -2566,6 +2566,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 


	nointroute	[IA-64]



	noinvpcid	[X86] Disable the INVPCID cpu feature.



	nojitter	[IA-64] Disables jitter checking for ITC timers.



	no-kvmclock	[X86,KVM] Disable paravirtualized KVM clock driver

arch/x86/kernel/cpu/common.c

+16 −0
Original line number Diff line number Diff line
@@ -162,6 +162,22 @@ static int __init x86_mpx_setup(char *s) 
}

__setup("nompx", x86_mpx_setup);



static int __init x86_noinvpcid_setup(char *s)

{

	/* noinvpcid doesn't accept parameters */

	if (s)

		return -EINVAL;



	/* do not emit a message if the feature is not present */

	if (!boot_cpu_has(X86_FEATURE_INVPCID))

		return 0;



	setup_clear_cpu_cap(X86_FEATURE_INVPCID);

	pr_info("noinvpcid: INVPCID feature disabled\n");

	return 0;

}

early_param("noinvpcid", x86_noinvpcid_setup);



#ifdef CONFIG_X86_32

static int cachesize_override = -1;

static int disable_x86_serial_nr = 1;