--- xen-4.14.0/xen/include/crypto/vmac.h.orig	2020-07-23 16:07:51.000000000 +0100
+++ xen-4.14.0/xen/include/crypto/vmac.h	2020-10-24 15:45:49.246467465 +0100
@@ -142,7 +142,7 @@
 
 #define vmac_update vhash_update
 
-void vhash_update(unsigned char m[],
+void vhash_update(uint8_t *m,
           unsigned int mbytes,
           vmac_ctx_t *ctx);
 
diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c
index 320e06f..618ae92 100644
--- a/xen/arch/x86/tboot.c
+++ b/xen/arch/x86/tboot.c
@@ -91,7 +91,7 @@ static void __init tboot_copy_memory(unsigned char *va, uint32_t size,
 
 void __init tboot_probe(void)
 {
-    tboot_shared_t *tboot_shared;
+    tboot_shared_t * volatile tboot_shared;
     static const uuid_t __initconst tboot_shared_uuid = TBOOT_SHARED_UUID;
 
     /* Look for valid page-aligned address for shared page. */