version: Document guest_handle

And what it is usually used for.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/include/public/version.h b/xen/include/public/version.h
index 44f26b0cb57153e0997a5de999b96d0e5d168649..24a582f32d981371084fc195ef365135bc8add13 100644 (file)
--- a/xen/include/public/version.h
+++ b/xen/include/public/version.h
@@ -77,7 +77,11 @@ typedef struct xen_feature_info xen_feature_info_t;
 /* arg == NULL; returns host memory page size. */
 #define XENVER_pagesize 7
 
-/* arg == xen_domain_handle_t. */
+/* arg == xen_domain_handle_t.
+ *
+ * The toolstack fills it out for guest consumption. It is intended to hold
+ * the UUID of the guest.
+ */
 #define XENVER_guest_handle 8
 
 #define XENVER_commandline 9