From 959b4fdfe7e27bcf101e2381e500e4076f2bb9ce Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Wed, 2 May 2007 19:27:16 +0200
Subject: [PATCH] [PATCH] i386: PARAVIRT: Allow boot-time disable of
paravirt_ops patching
Add "noreplace-paravirt" to disable paravirt_ops patching.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
Documentation/kernel-parameters.txt | 3 +++
arch/i386/kernel/alternative.c | 13 +++++++++++++
2 files changed, 16 insertions(+)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 242b3a09b6ceb..38d7db3262c7e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -64,6 +64,7 @@ parameter is applicable:
GENERIC_TIME The generic timeofday code is enabled.
NFS Appropriate NFS support is enabled.
OSS OSS sound support is enabled.
+ PV_OPS A paravirtualized kernel
PARIDE The ParIDE subsystem is enabled.
PARISC The PA-RISC architecture is enabled.
PCI PCI bus support is enabled.
@@ -1164,6 +1165,8 @@ and is between 256 and 4096 characters. It is defined in the file
nomce [IA-32] Machine Check Exception
+ noreplace-paravirt [IA-32,PV_OPS] Don't patch paravirt_ops
+
noreplace-smp [IA-32,SMP] Don't replace SMP instructions
with UP alternatives
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index c5d037c60950f..080a59d56ea69 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -30,6 +30,16 @@ static int __init setup_noreplace_smp(char *str)
}
__setup("noreplace-smp", setup_noreplace_smp);
+#ifdef CONFIG_PARAVIRT
+static int noreplace_paravirt = 0;
+
+static int __init setup_noreplace_paravirt(char *str)
+{
+ noreplace_paravirt = 1;
+ return 1;
+}
+__setup("noreplace-paravirt", setup_noreplace_paravirt);
+#endif
#define DPRINTK(fmt, args...) if (debug_alternative) \
printk(KERN_DEBUG fmt, args)
@@ -330,6 +340,9 @@ void apply_paravirt(struct paravirt_patch_site *start,
{
struct paravirt_patch_site *p;
+ if (noreplace_paravirt)
+ return;
+
for (p = start; p < end; p++) {
unsigned int used;
--
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