From d81c695b3a38569a5c9e95f6bc366e34151fa612 Mon Sep 17 00:00:00 2001
From: Brad House <brad@brad-house.com>
Date: Wed, 29 Oct 2025 10:57:27 -0400
Subject: [PATCH 1/4] use Free Page Reporting

---
 .../com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java     | 6 +++++-
 .../hypervisor/kvm/resource/LibvirtDomainXMLParserTest.java | 4 ++--
 .../com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java | 2 +-
 .../wrapper/LibvirtMigrateVolumeCommandWrapperTest.java     | 2 +-
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java
index 46a5024bf154..bce0849a1819 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java
@@ -1340,7 +1340,11 @@ public String getMemBalloonStatsPeriod() {
         @Override
         public String toString() {
             StringBuilder memBalloonBuilder = new StringBuilder();
-            memBalloonBuilder.append("<memballoon model='" + memBalloonModel + "'>\n");
+            memBalloonBuilder.append("<memballoon model='" + memBalloonModel + "'");
+            if (memBalloonModel != MemBalloonModel.NONE) {
+                memBalloonBuilder.append(" autodeflate='on' freePageReporting='on'");
+            }
+            memBalloonBuilder.append(">\n");
             if (StringUtils.isNotBlank(memBalloonStatsPeriod)) {
                 memBalloonBuilder.append("<stats period='" + memBalloonStatsPeriod +"'/>\n");
             }
diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtDomainXMLParserTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtDomainXMLParserTest.java
index de50cf342024..e73b40798668 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtDomainXMLParserTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtDomainXMLParserTest.java
@@ -196,7 +196,7 @@ public void testDomainXMLParser() {
                      "<alias name='video0'/>" +
                      "<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>" +
                      "</video>" +
-                     "<memballoon model='virtio'>" +
+                     "<memballoon model='virtio' autodeflate='on' freePageReporting='on'>" +
                      "<stats period='60'/>" +
                      "<alias name='balloon0'/>" +
                      "<address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>" +
@@ -379,7 +379,7 @@ public void testDomainXMLParserWithoutModelName() {
                 "    <redirdev bus='usb' type='spicevmc'>\n" +
                 "      <address type='usb' bus='0' port='3'/>\n" +
                 "    </redirdev>\n" +
-                "    <memballoon model='virtio'>\n" +
+                "    <memballoon model='virtio' autodeflate='on' freePageReporting='on'>\n" +
                 "      <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>\n" +
                 "    </memballoon>\n" +
                 "  </devices>\n" +
diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
index 856dc0be9dcf..a429bbf8c3f5 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
@@ -465,7 +465,7 @@ public void memBalloonDefTestNone() {
 
     @Test
     public void memBalloonDefTestVirtio() {
-        String expectedXml = "<memballoon model='virtio'>\n<stats period='60'/>\n</memballoon>";
+        String expectedXml = "<memballoon model='virtio' autodeflate='on' freePageReporting='on'>\n<stats period='60'/>\n</memballoon>";
         MemBalloonDef memBalloonDef = new MemBalloonDef();
         memBalloonDef.defVirtioMemBalloon("60");
 
diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtMigrateVolumeCommandWrapperTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtMigrateVolumeCommandWrapperTest.java
index 4f1eba1a772a..e3d35dfb4d1f 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtMigrateVolumeCommandWrapperTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtMigrateVolumeCommandWrapperTest.java
@@ -208,7 +208,7 @@ public class LibvirtMigrateVolumeCommandWrapperTest {
             "      <alias name='watchdog0'/>\n" +
             "      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>\n" +
             "    </watchdog>\n" +
-            "    <memballoon model='virtio'>\n" +
+            "    <memballoon model='virtio' autodeflate='on' freePageReporting='on'>\n" +
             "      <alias name='balloon0'/>\n" +
             "      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>\n" +
             "    </memballoon>\n" +

From c57377a08d3b936dca908c9d733d517d2ba0a9ae Mon Sep 17 00:00:00 2001
From: Brad House <brad@brad-house.com>
Date: Wed, 29 Oct 2025 17:56:30 -0400
Subject: [PATCH 2/4] add qemu and libvirt version checks

---
 .../java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java  | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java
index bce0849a1819..22d143d87b15 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java
+++ b/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");

From f6a92dac7a6b9410019390a9529218ada78abbb1 Mon Sep 17 00:00:00 2001
From: Brad House <brad@brad-house.com>
Date: Wed, 29 Oct 2025 19:17:27 -0400
Subject: [PATCH 3/4] add test for old and new libvirt/qemu

---
 .../hypervisor/kvm/resource/LibvirtVMDefTest.java   | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
index a429bbf8c3f5..f97728d6bbc9 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
@@ -465,6 +465,8 @@ public void memBalloonDefTestNone() {
 
     @Test
     public void memBalloonDefTestVirtio() {
+        LibvirtVMDef.setGlobalQemuVersion(5001000L);
+        LibvirtVMDef.setGlobalLibvirtVersion(6009000L);
         String expectedXml = "<memballoon model='virtio' autodeflate='on' freePageReporting='on'>\n<stats period='60'/>\n</memballoon>";
         MemBalloonDef memBalloonDef = new MemBalloonDef();
         memBalloonDef.defVirtioMemBalloon("60");
@@ -474,6 +476,17 @@ public void memBalloonDefTestVirtio() {
         assertEquals(expectedXml, xmlDef);
     }
 
+    @Test
+    public void memBalloonDefTestVirtioOld() {
+        String expectedXml = "<memballoon model='virtio'>\n<stats period='60'/>\n</memballoon>";
+        MemBalloonDef memBalloonDef = new MemBalloonDef();
+        memBalloonDef.defVirtioMemBalloon("60");
+
+        String xmlDef = memBalloonDef.toString();
+
+        assertEquals(expectedXml, xmlDef);
+    }
+
     @Test
     public void testHypervEnlightDef() {
         LibvirtVMDef.FeaturesDef featuresDef = new LibvirtVMDef.FeaturesDef();

From f43cdf9f6d11a88abaf756af08ca9dce3fcebffe Mon Sep 17 00:00:00 2001
From: Brad House <brad@brad-house.com>
Date: Wed, 29 Oct 2025 20:07:53 -0400
Subject: [PATCH 4/4] revert back to older versions

---
 .../com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java     | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
index f97728d6bbc9..56ad267eac7e 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
@@ -478,6 +478,8 @@ public void memBalloonDefTestVirtio() {
 
     @Test
     public void memBalloonDefTestVirtioOld() {
+        LibvirtVMDef.setGlobalQemuVersion(2006000L);
+        LibvirtVMDef.setGlobalLibvirtVersion(9008L);
         String expectedXml = "<memballoon model='virtio'>\n<stats period='60'/>\n</memballoon>";
         MemBalloonDef memBalloonDef = new MemBalloonDef();
         memBalloonDef.defVirtioMemBalloon("60");