From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Wed, 19 Sep 2007 05:46:33 +0000 (-0700)
Subject: xen: don't bother trying to set cr4
X-Git-Tag: v2.6.23-rc7~22
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=389a3c02496dd1b399bb0efd005e9fa2be24e9ee;p=linux-2.6

xen: don't bother trying to set cr4

Xen ignores all updates to cr4, and some versions will kill the domain if
you try to change its value.  Just ignore all changes.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/i386/xen/enlighten.c b/arch/i386/xen/enlighten.c
index f0c37511d8..f01bfcd4bd 100644
--- a/arch/i386/xen/enlighten.c
+++ b/arch/i386/xen/enlighten.c
@@ -623,8 +623,8 @@ static unsigned long xen_read_cr2_direct(void)
 
 static void xen_write_cr4(unsigned long cr4)
 {
-	/* never allow TSC to be disabled */
-	native_write_cr4(cr4 & ~X86_CR4_TSD);
+	/* Just ignore cr4 changes; Xen doesn't allow us to do
+	   anything anyway. */
 }
 
 static unsigned long xen_read_cr3(void)