hypervisor: allow Ubuntu 18.04 to be added as KVM host (#2626)

This adds and allows Ubuntu 18.04 to be used as KVM host. In addition,
on the UI when hypervisor version key is missing, this adds and display
the host os and version detail which is useful to show the KVM host
os and version.

When cache mode 'none' is used for empty cdrom drives, systemvms
and guest VMs fail to start on newer libvirtd such as Ubuntu bionic.
The fix is ensure that cachemode is not declared when drives are empty
upon starting of the VM. Similar issue logged at redhat here:
https://bugzilla.redhat.com/show_bug.cgi?id=1342999

The workaround is to ensure that we don't configure cachemode for
cdrom devices at all. This also fixes live VM migration issue.

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: yadvr

debian/control

@@ -22,7 +22,7 @@ Description: CloudStack server library
 
 Package: cloudstack-agent
 Architecture: all
-Depends: ${python:Depends}, openjdk-8-jre-headless | java8-runtime-headless | java8-runtime, cloudstack-common (= ${source:Version}), lsb-base (>= 4.0), libcommons-daemon-java, openssh-client, qemu-kvm (>= 1.0), libvirt-bin (>= 1.2.2), uuid-runtime, iproute, ebtables, vlan, jsvc, ipset, python-libvirt, ethtool, iptables, lsb-release, init-system-helpers (>= 1.14~), aria2
+Depends: ${python:Depends}, openjdk-8-jre-headless | java8-runtime-headless | java8-runtime, cloudstack-common (= ${source:Version}), lsb-base (>= 4.0), libcommons-daemon-java, openssh-client, qemu-kvm (>= 1.0), libvirt-bin (>= 1.2.2), uuid-runtime, iproute2, ebtables, vlan, jsvc, ipset, python-libvirt, ethtool, iptables, lsb-release, init-system-helpers (>= 1.14~), aria2
 Recommends: init-system-helpers
 Conflicts: cloud-agent, cloud-agent-libs, cloud-agent-deps, cloud-agent-scripts
 Description: CloudStack agent

plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtDomainXMLParser.java

@@ -121,7 +121,7 @@ public boolean parseDomainXML(String domXML) {
                         def.defBlockBasedDisk(diskDev, diskLabel,
                             DiskDef.DiskBus.valueOf(bus.toUpperCase()));
                     }
-                    if (diskCacheMode != null) {
+                    if (StringUtils.isNotBlank(diskCacheMode)) {
                         def.setCacheMode(DiskDef.DiskCacheMode.valueOf(diskCacheMode.toUpperCase()));
                     }
                 }

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

@@ -819,8 +819,12 @@ public String toString() {
             diskBuilder.append(" type='" + _diskType + "'");
             diskBuilder.append(">\n");
             if(qemuDriver) {
-                diskBuilder.append("<driver name='qemu'" + " type='" + _diskFmtType
-                        + "' cache='" + _diskCacheMode + "' ");
+                diskBuilder.append("<driver name='qemu'" + " type='" + _diskFmtType + "' ");
+
+                if (_deviceType != DeviceType.CDROM) {
+                    diskBuilder.append("cache='" + _diskCacheMode + "' ");
+                }
+
                 if(_discard != null && _discard != DiscardType.IGNORE) {
                     diskBuilder.append("discard='" + _discard.toString() + "' ");
                 }

plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStopCommandWrapper.java

@@ -71,7 +71,7 @@ public Answer execute(final StopCommand command, final LibvirtComputingResource
                 //move the command line file to backup.
                 s_logger.debug("backing up the cmdline");
                 try{
-                    Pair<Boolean, String> ret = SshHelper.sshExecute(command.getControlIp(), 3922, "root", pemFile, null,"mv -f "+CMDLINE_PATH+" "+CMDLINE_BACKUP_PATH);
+                    Pair<Boolean, String> ret = SshHelper.sshExecute(command.getControlIp(), 3922, "root", pemFile, null,"cp -f "+CMDLINE_PATH+" "+CMDLINE_BACKUP_PATH);
                     if(!ret.first()){
                         s_logger.debug("Failed to backup cmdline file due to "+ret.second());
                     }

ui/scripts/system.js

@@ -17484,6 +17484,10 @@
                                                 item.powerstate = item.outofbandmanagement.powerstate;
                                             }
 
+                                            if (!item.hypervisorversion && item.details && item.details["Host.OS"]) {
+                                                item.hypervisorversion =  item.details["Host.OS"] + " " +  item.details["Host.OS.Version"];
+                                            }
+
                                             if (item && item.hostha) {
                                                 item.hastate = item.hostha.hastate;
                                                 item.haprovider = item.hostha.haprovider;