Xen devel - Dec 2011 - [PATCH] linux-2.6.18/x86: refuse to initialize the microcode driver in DomU

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/arch/i386/kernel/microcode-xen.c
+++ b/arch/i386/kernel/microcode-xen.c
@@ -121,6 +121,9 @@ static int __init microcode_init (void)
 {
 	int error;
 
+	if (!is_initial_xendomain())
+		return -ENODEV;
+
 	error = misc_register(&microcode_dev);
 	if (error) {
 		printk(KERN_ERR