+#ifdef __XEN__
+#if defined(__i386__)
+#define set_xen_guest_handle(hnd, val) \
+ do { \
+ if (sizeof(hnd) == 8) \
+ *(uint64_t *)&(hnd) = 0; \
+ (hnd).p = val; \
+ } while (0)
+#elif defined(__x86_64__)
+#define set_xen_guest_handle(hnd, val) do { (hnd).p = val; } while (0)
+#endif
+#else
+#if defined(__i386__)
+#define set_xen_guest_handle(hnd, val) \
+ do { \
+ if (sizeof(hnd) == 8) \
+ *(uint64_t *)&(hnd) = 0; \
+ (hnd) = val; \
+ } while (0)
+#elif defined(__x86_64__)
+#define set_xen_guest_handle(hnd, val) do { (hnd) = val; } while (0)
+#endif
+#endif
+