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 <[email protected]> Cc: Andi Kleen <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
chewitt · Sep 19, 2007 · 389a3c0 · 389a3c0
1 parent 248bdd5
commit 389a3c0
Showing 1 changed file with 2 additions and 2 deletions.
diff --git 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)