Index: 2007-04-27/xen/arch/x86/traps.c
===================================================================
--- 2007-04-27.orig/xen/arch/x86/traps.c	2007-04-27 11:02:48.000000000 +0200
+++ 2007-04-27/xen/arch/x86/traps.c	2007-05-09 17:56:43.000000000 +0200
@@ -594,6 +594,8 @@ static int emulate_forced_invalid_op(str
     else if ( regs->eax == 0x80000001 )
     {
         /* Modify Feature Information. */
+        if ( is_pv_32on64_vcpu(current) )
+            clear_bit(X86_FEATURE_SYSCALL % 32, &d);
         clear_bit(X86_FEATURE_RDTSCP % 32, &d);
     }
     else