File xsa321-5.patch of Package xen.26345

From: <security@xenproject.org>
Subject: x86/alternative: introduce alternative_2

It's based on alternative_io_2 without inputs or outputs but with an
added memory clobber.

This is part of XSA-321.

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

--- a/xen/include/asm-x86/alternative.h
+++ b/xen/include/asm-x86/alternative.h
@@ -85,6 +85,11 @@ extern void alternative_instructions(voi
 #define alternative(oldinstr, newinstr, feature)                        \
         asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
 
+#define alternative_2(oldinstr, newinstr1, feature1, newinstr2, feature2) \
+	asm volatile (ALTERNATIVE_2(oldinstr, newinstr1, feature1,	\
+				    newinstr2, feature2)		\
+		      : : : "memory")
+
 /*
  * Alternative inline assembly with input.
  *