docs: formatdomain: Mention the QEMU requirement for discard_no_unref

Signed-off-by: Han Han <hhan@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index 973de8dd4f31ef30bad3df4a61595945db38bb8b..cd9cb02bf8be69845a3c0d37117bd77e973497b3 100644 (file)
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -3296,7 +3296,8 @@ paravirtualized driver is specified via the ``disk`` element.
       image. When enabled, a discard request from within the guest will mark the
       qcow2 cluster as zero, but will keep the reference/offset of that cluster.
       But it will still pass the discard further to the lower layer.
-      This will resolve fragmentation within the qcow2 image. :since:`Since 9.5.0`
+      This will resolve fragmentation within the qcow2 image. :since:`Since 9.5.0
+      (QEMU 8.1)`
 
       In the majority of cases the default configuration used by the hypervisor
       is sufficient so modifying this setting should not be necessary. For