Commit 0790c9aa authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
Browse files

x86/mm: Add the 'nopcid' boot option to turn off PCID

The parameter is only present on x86_64 systems to save a few bytes,
as PCID is always disabled on x86_32.

Signed-off-by: default avatarAndy Lutomirski <>
Reviewed-by: default avatarNadav Amit <>
Reviewed-by: default avatarBorislav Petkov <>
Reviewed-by: default avatarThomas Gleixner <>
Cc: Andrew Morton <>
Cc: Arjan van de Ven <>
Cc: Borislav Petkov <>
Cc: Dave Hansen <>
Cc: Linus Torvalds <>
Cc: Mel Gorman <>
Cc: Peter Zijlstra <>
Cc: Rik van Riel <>

Signed-off-by: default avatarIngo Molnar <>
parent cba4671a
......@@ -2657,6 +2657,8 @@
nopat [X86] Disable PAT (page attribute table extension of
pagetables) support.
nopcid [X86-64] Disable the PCID cpu feature.
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
......@@ -168,6 +168,24 @@ static int __init x86_mpx_setup(char *s)
__setup("nompx", x86_mpx_setup);
#ifdef CONFIG_X86_64
static int __init x86_pcid_setup(char *s)
/* require an exact match without trailing characters */
if (strlen(s))
return 0;
/* do not emit a message if the feature is not present */
if (!boot_cpu_has(X86_FEATURE_PCID))
return 1;
pr_info("nopcid: PCID feature disabled\n");
return 1;
__setup("nopcid", x86_pcid_setup);
static int __init x86_noinvpcid_setup(char *s)
/* noinvpcid doesn't accept parameters */
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