add qemu and libvirt version checks

Author: bradh352

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java

@@ -1341,7 +1341,9 @@ public String getMemBalloonStatsPeriod() {
         public String toString() {
             StringBuilder memBalloonBuilder = new StringBuilder();
             memBalloonBuilder.append("<memballoon model='" + memBalloonModel + "'");
-            if (memBalloonModel != MemBalloonModel.NONE) {
+            /* Version integer format: major * 1,000,000 + minor * 1,000 + release.
+             * Require: libvirt 6.9.0, qemu 5.1.0 */
+            if (memBalloonModel != MemBalloonModel.NONE && s_qemuVersion >= 5001000 && s_libvirtVersion >= 6009000) {
                 memBalloonBuilder.append(" autodeflate='on' freePageReporting='on'");
             }
             memBalloonBuilder.append(">\n");