Allow KVM overcommit to work without reducing minimum VM memory when vm ballooning is disabled

agent/conf/agent.properties

@@ -218,8 +218,9 @@ hypervisor.type=kvm
 #guest.cpu.features=
 
 # Disables memory ballooning on VM guests for overcommit.
-# By default overcommit feature enables balloon and sets currentMemory to a minimum value.
-#vm.memballoon.disable=false
+# By default this feature is disabled, when enabled by setting the value to false
+# the overcommit feature enables balloon and sets currentMemory to a minimum value.
+#vm.memballoon.disable=true
 
 # The time interval (in seconds) at which the balloon driver will get memory stats updates.
 # This is equivalent to Libvirt's --period parameter when using the dommemstat command.

agent/src/main/java/com/cloud/agent/properties/AgentProperties.java

@@ -395,11 +395,11 @@ public class AgentProperties{
 
     /**
      * Disables memory ballooning on VM guests for overcommit.<br>
-     * By default overcommit feature enables balloon and sets currentMemory to a minimum value.<br>
+     * By default the setting is disabled; when it's enabled overcommit feature enables balloon and sets currentMemory to a minimum value.<br>
      * Data type: Boolean.<br>
-     * Default value: <code>false</code>
+     * Default value: <code>true</code>
      */
-    public static final Property<Boolean> VM_MEMBALLOON_DISABLE = new Property<>("vm.memballoon.disable", false);
+    public static final Property<Boolean> VM_MEMBALLOON_DISABLE = new Property<>("vm.memballoon.disable", true);
 
     /**
      * Set to true to check disk activity on VM's disks before starting a VM.<br>

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

@@ -2780,15 +2780,10 @@ protected GuestResourceDef createGuestResourceDef(VirtualMachineTO vmTO){
 
         grd.setMemBalloning(!_noMemBalloon);
 
-        long maxRam = ByteScaleUtils.bytesToKibibytes(vmTO.getMaxRam());
-        long currRam = vmTO.getType() == VirtualMachine.Type.User ? getCurrentMemAccordingToMemBallooning(vmTO, maxRam) : maxRam;
-
-        if (s_logger.isTraceEnabled()) {
-            s_logger.trace(String.format("memory values for VM %s are %d/%d",vmTO.getName(),maxRam, currRam));
-        }
+        Long maxRam = ByteScaleUtils.bytesToKibibytes(vmTO.getMaxRam());
 
         grd.setMemorySize(maxRam);
-        grd.setCurrentMem(currRam);
+        grd.setCurrentMem(getCurrentMemAccordingToMemBallooning(vmTO, maxRam));
 
         int vcpus = vmTO.getCpus();
         Integer maxVcpus = vmTO.getVcpuMaxLimit();

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

@@ -282,7 +282,7 @@ public void setMemBalloning(boolean memoryBalloning) {
         @Override
         public String toString() {
             StringBuilder response = new StringBuilder();
-            response.append(String.format("<memory>%s</memory>\n", this.memory));
+            response.append(String.format("<memory>%s</memory>\n", this.currentMemory));
             response.append(String.format("<currentMemory>%s</currentMemory>\n", this.currentMemory));
 
             if (this.memory > this.currentMemory) {
@@ -1238,7 +1238,7 @@ public String getMemBalloonStatsPeriod() {
         @Override
         public String toString() {
             StringBuilder memBalloonBuilder = new StringBuilder();
-            memBalloonBuilder.append("<memballoon model='" + memBalloonModel + "' autodeflate='on'>\n");
+            memBalloonBuilder.append("<memballoon model='" + memBalloonModel + "'>\n");
             if (StringUtils.isNotBlank(memBalloonStatsPeriod)) {
                 memBalloonBuilder.append("<stats period='" + memBalloonStatsPeriod +"'/>\n");
             }

plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtComputingResourceTest.java

@@ -760,7 +760,7 @@ private void verifyVcpu(VirtualMachineTO to, Document domainDoc) {
 
     private void verifyMemory(VirtualMachineTO to, Document domainDoc, String minRam) {
         assertXpath(domainDoc, "/domain/maxMemory/text()", String.valueOf( to.getMaxRam() / 1024 ));
-        assertXpath(domainDoc, "/domain/currentMemory/text()",minRam);
+        assertXpath(domainDoc, "/domain/memory/text()",minRam);
         assertXpath(domainDoc, "/domain/cpu/numa/cell/@memory", minRam);
         assertXpath(domainDoc, "/domain/currentMemory/text()", minRam);
     }

plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java

@@ -214,11 +214,11 @@ public void testDiskDef() {
         assertEquals(bus, disk.getBusType());
         assertEquals(DiskDef.DeviceType.DISK, disk.getDeviceType());
 
-        String resultingXml = disk.toString();
+        String xmlDef = disk.toString();
         String expectedXml = "<disk  device='disk' type='file'>\n<driver name='qemu' type='" + type.toString() + "' cache='" + cacheMode.toString() + "' />\n" +
                              "<source file='" + filePath + "'/>\n<target dev='" + diskLabel + "' bus='" + bus.toString() + "'/>\n</disk>\n";
 
-        assertEquals(expectedXml, resultingXml);
+        assertEquals(xmlDef, expectedXml);
     }
 
     @Test
@@ -236,7 +236,7 @@ public void testDiskDefWithEncryption() {
             "<secret type='passphrase' uuid='" + passphraseUuid + "' />\n" +
             "</encryption>\n" +
             "</disk>\n";
-        assertEquals(expectedXML, disk.toString());
+        assertEquals(disk.toString(), expectedXML);
     }
 
     @Test
@@ -346,7 +346,7 @@ public void testDiskDefWithBurst() {
         LibvirtVMDef.setGlobalQemuVersion(2006000L);
         LibvirtVMDef.setGlobalLibvirtVersion(9008L);
 
-        String resultingXml = disk.toString();
+        String xmlDef = disk.toString();
         String expectedXml = "<disk  device='disk' type='file'>\n<driver name='qemu' type='" + type.toString() + "' cache='none' />\n" +
                 "<source file='" + filePath + "'/>\n<target dev='" + diskLabel + "' bus='" + bus.toString() + "'/>\n" +
                 "<iotune>\n<read_bytes_sec>"+bytesReadRate+"</read_bytes_sec>\n<write_bytes_sec>"+bytesWriteRate+"</write_bytes_sec>\n" +
@@ -356,29 +356,29 @@ public void testDiskDefWithBurst() {
                 "<read_bytes_sec_max_length>"+bytesReadRateMaxLength+"</read_bytes_sec_max_length>\n<write_bytes_sec_max_length>"+bytesWriteRateMaxLength+"</write_bytes_sec_max_length>\n" +
                 "<read_iops_sec_max_length>"+iopsReadRateMaxLength+"</read_iops_sec_max_length>\n<write_iops_sec_max_length>"+iopsWriteRateMaxLength+"</write_iops_sec_max_length>\n</iotune>\n</disk>\n";
 
-                assertEquals(expectedXml, resultingXml);
+                assertEquals(xmlDef, expectedXml);
     }
 
     @Test
     public void memBalloonDefTestNone() {
-        String expectedXml = "<memballoon model='none' autodeflate='on'>\n</memballoon>";
+        String expectedXml = "<memballoon model='none'>\n</memballoon>";
         MemBalloonDef memBalloonDef = new MemBalloonDef();
         memBalloonDef.defNoneMemBalloon();
 
-        String resultingXml = memBalloonDef.toString();
+        String xmlDef = memBalloonDef.toString();
 
-        assertEquals(expectedXml, resultingXml);
+        assertEquals(xmlDef, expectedXml);
     }
 
     @Test
     public void memBalloonDefTestVirtio() {
-        String expectedXml = "<memballoon model='virtio' autodeflate='on'>\n<stats period='60'/>\n</memballoon>";
+        String expectedXml = "<memballoon model='virtio'>\n<stats period='60'/>\n</memballoon>";
         MemBalloonDef memBalloonDef = new MemBalloonDef();
         memBalloonDef.defVirtioMemBalloon("60");
 
-        String resultingXml = memBalloonDef.toString();
+        String xmlDef = memBalloonDef.toString();
 
-        assertEquals(expectedXml, resultingXml);
+        assertEquals(xmlDef, expectedXml);
     }
 
     @Test
@@ -413,11 +413,11 @@ public void testRngDef() {
         int bytes = 2048;
 
         LibvirtVMDef.RngDef def = new LibvirtVMDef.RngDef(path, backendModel, bytes, period);
-        assertEquals(path, def.getPath());
-        assertEquals(backendModel, def.getRngBackendModel());
-        assertEquals(LibvirtVMDef.RngDef.RngModel.VIRTIO, def.getRngModel());
-        assertEquals(bytes, def.getRngRateBytes());
-        assertEquals(period, def.getRngRatePeriod());
+        assertEquals(def.getPath(), path);
+        assertEquals(def.getRngBackendModel(), backendModel);
+        assertEquals(def.getRngModel(), LibvirtVMDef.RngDef.RngModel.VIRTIO);
+        assertEquals(def.getRngRateBytes(), bytes);
+        assertEquals(def.getRngRatePeriod(), period);
     }
 
     @Test
@@ -441,8 +441,8 @@ public void testWatchDogDef() {
         LibvirtVMDef.WatchDogDef.WatchDogAction action = LibvirtVMDef.WatchDogDef.WatchDogAction.RESET;
 
         LibvirtVMDef.WatchDogDef def = new LibvirtVMDef.WatchDogDef(action, model);
-        assertEquals(model, def.getModel());
-        assertEquals(action, def.getAction());
+        assertEquals(def.getModel(), model);
+        assertEquals(def.getAction(), action);
     }
 
     @Test
@@ -453,6 +453,6 @@ public void testSCSIDef() {
                 "<address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>\n" +
                 "<driver queues='4'/>\n" +
                 "</controller>\n";
-        assertEquals(expected, str);
+        assertEquals(str, expected);
     }
 }