+#ifdef CONFIG_XEN
+struct bio_vec;
+
+extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
+ const struct bio_vec *vec2);
+
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
+ (__BIOVEC_PHYS_MERGEABLE(vec1, vec2) && \
+ (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
+#endif /* CONFIG_XEN */
+