xen: don't bother trying to set cr4

PATCH New Jeremy Fitzhardinge 1 participant 1 message Sep 12, 2007

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Jeremy Fitzhardinge

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2007-09-12 23:44 UTC #0 lore raw

PATCH 1/1 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]>

---
 arch/i386/xen/enlighten.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

===================================================================

arch/i386/xen/enlighten.c +2 -2

@@ -625,8 +625,8 @@ static unsigned long xen_read_cr2_direct
 
 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)