diff --git a/xen/arch/arm/include/asm/cache.h b/xen/arch/arm/include/asm/cache.h
index 240b6ae0ea..029b2896fb 100644
--- a/xen/arch/arm/include/asm/cache.h
+++ b/xen/arch/arm/include/asm/cache.h
@@ -6,6 +6,7 @@
 #define L1_CACHE_SHIFT  (CONFIG_ARM_L1_CACHE_SHIFT)
 #define L1_CACHE_BYTES  (1 << L1_CACHE_SHIFT)
 
+/* TODO: Phase out the use of this via cache.h */
 #define __read_mostly __section(".data.read_mostly")
 
 #endif
diff --git a/xen/arch/ppc/include/asm/cache.h b/xen/arch/ppc/include/asm/cache.h
index 0d7323d789..13c0bf3242 100644
--- a/xen/arch/ppc/include/asm/cache.h
+++ b/xen/arch/ppc/include/asm/cache.h
@@ -3,6 +3,7 @@
 #ifndef _ASM_PPC_CACHE_H
 #define _ASM_PPC_CACHE_H
 
+/* TODO: Phase out the use of this via cache.h */
 #define __read_mostly __section(".data.read_mostly")
 
 #endif /* _ASM_PPC_CACHE_H */
diff --git a/xen/arch/x86/include/asm/cache.h b/xen/arch/x86/include/asm/cache.h
index e4770efb22..956c05493e 100644
--- a/xen/arch/x86/include/asm/cache.h
+++ b/xen/arch/x86/include/asm/cache.h
@@ -9,6 +9,7 @@
 #define L1_CACHE_SHIFT	(CONFIG_X86_L1_CACHE_SHIFT)
 #define L1_CACHE_BYTES	(1 << L1_CACHE_SHIFT)
 
+/* TODO: Phase out the use of this via cache.h */
 #define __read_mostly __section(".data.read_mostly")
 
 #ifndef __ASSEMBLY__
diff --git a/xen/include/xen/cache.h b/xen/include/xen/cache.h
index f52a0aedf7..55456823c5 100644
--- a/xen/include/xen/cache.h
+++ b/xen/include/xen/cache.h
@@ -15,6 +15,7 @@
 #define __cacheline_aligned __attribute__((__aligned__(SMP_CACHE_BYTES)))
 #endif
 
+/* TODO: Phase out the use of this via cache.h */
 #define __ro_after_init __section(".data.ro_after_init")
 
 #endif /* __LINUX_CACHE_H */
diff --git a/xen/include/xen/sections.h b/xen/include/xen/sections.h
index b6cb5604c2..f2fac8d7fa 100644
--- a/xen/include/xen/sections.h
+++ b/xen/include/xen/sections.h
@@ -3,9 +3,30 @@
 #ifndef __XEN_SECTIONS_H__
 #define __XEN_SECTIONS_H__
 
+#include <xen/compiler.h>
+
 /* SAF-0-safe */
 extern char __init_begin[], __init_end[];
 
+/*
+ * Some data is expected to be written rarely (if at all).
+ *
+ * For performance reasons is it helpful to group such data in the build, to
+ * avoid the linker placing it adjacent to often-written data.
+ */
+#define __read_mostly __section(".data.read_mostly")
+
+/*
+ * Some data should be chosen during boot and be immutable thereafter.
+ *
+ * Variables annotated with __ro_after_init will become read-only after boot
+ * and suffer a runtime access fault if modified.
+ *
+ * For architectures/platforms which haven't implemented support, these
+ * variables will be treated as regular mutable data.
+ */
+#define __ro_after_init __section(".data.ro_after_init")
+
 #endif /* !__XEN_SECTIONS_H__ */
 /*
  * Local variables: