Libvirt

Author: g | 2025-04-25

libvirt-clients Programs for the libvirt library libvirt-clients-qemu Programs for the libvirt library (QEMU specific) libvirt-common data files for the libvirt library libvirt-daemon Virtualization daemon libvirt-daemon-common Virtualization daemon common files libvirt-daemon-config-network Libvirt daemon configuration files (default network)

libvirt: Module libvirt-domain from libvirt

DescriptionThis repository provides tools to build Oracle Linux images for cloud deployment.Note: as of March 2024 the scripts have been refactored and introduce breaking changes. See CHANGELOG for details.The tools are architected around distribution flavours and target clouds.They currently support:Distributions:Oracle Linux 7 update 9 -- Slim (x86_64 only)Oracle Linux 8 update 10 -- Slim (x86_64 and aarch64)Oracle Linux 9 update 4 -- Slim (x86_64 and aarch64)Clouds:Microsoft Azure cloud (x86_64)Target packages: WALinuxAgentImage format: VHDOracle Cloud Infrastructure (OCI) (x86_64 and aarch64)Target packages: qemu-guest-agent / cloud-initImage format: QCOW2Note: no specific OCI tools are actually installed; this image can be used in any cloud-init based environment.Oracle Linux Virtualization Manager (OLVM) (x86_64)Target packages: qemu-guest-agent / cloud-initImage format: OLVM OVAOracle VM Server (OVM) (x86_64)Target packages: oracle-template-config + vmapiImage format: OVM OVAVagrant (VirtualBox provider) (x86_64)Target packages: VirtualBox guest additionsImage format: boxVagrant (libvirt provider) (x86_64)Target packages: nfs-utilsImage format: boxUTM (UTM for macOS) (aarch64)Target packages: noneImage format: utmNote: only for aarch64 distributionsGeneric (No cloud setup) (x86_64 and aarch64)Target packages: noneImage format: VirtualBox OVA or QCOW2 (depending on the builder used)RequirementsOverviewThe tools require a Linux host supporting KVM virtualization with the following installed:qemu-kvm (Including qemu-img)libvirtvirt-installlibguestfs (including tools)Additionally:the host architecture must match the architecture of the target image (e.g.: an aarch64 host is needed to build aarch64 images)the host kernel must support the filesystem used in the guest (e.g.: the host kernel must support btrfs to build an image with a btrfs filesystem)For building HashiCorp Vagrant boxes for the libvirt provider, download the create_box.sh third party script from the vagrant-libvirt project or install Vagrant and the vagrant-libvirt plugin.Oracle Linux 8dnf module install virtdnf install qemu-img libguestfs-tools virt-installdnf install zip # For UTM imagesOracle Linux 9dnf install libvirt qemu-kvm libguestfsdnf install qemu-img guestfs-tools virt-installdnf install zip # For UTM imagesBuild instructionsThe image builder does not require system privileges and should not be run as root.Clone this repo:git clone up a separate workspace directory where the image will be built.Ensure there is enough free space in the workspace partition, the builder will need up the two times the image size.Configure your build environment in the env.properties file (or in a copy).Minimal configuration:WORKSPACE: path of your workspace directoryISO_URL: location of the Oracle Linux distribution ISOISO_CHECKSUM: checksum for the ISO fileChecksums files are available on the Verify Oracle Linux Downloads pageCLOUD: cloud target (azure, oci, olvm, ovm, utm, vagrant-libvirt, vagrant-virtualbox or none)Run the builder as a non-privileged user:./bin/build-image.sh --env ENV_PROPERTY_FILE`Advanced configurationUsing boot ISO imagesInstead of providing an Oracle Linux distribution ISO you can use a boot ISO image.In that case, you will have to provide an URL to an installation tree and optionally additional yum repositories required by the installation.Example for an Oracle Linux 9 using the UEK boot ISO:ISO_URL=" buildsThe build tool can be KVM-QEMUPerforming virtualization in Linux requires three components:KVM works exclusively with QEMU and performs hardware acceleration for x86 VMs with Intel and AMD CPUs. KVM and QEMU are hypervisors that emulate the VMs; the pair is often called KVM-QEMU or just KVM.QEMU is a machine emulator that can allow the host machine to emulate the CPU architecture of the guest machine. Because QEMU does not provide hardware acceleration, it works well with KVM.libvirt provides an abstraction language to define and launch VMs, but is normally used just to launch single VMs. It uses XML to represent and define the VM.This section describes how to install and set up Cumulus VX with KVM/QEMU and Libvirt on a Linux server to create the two leaf and one spine topology shown below.In the topology, leaf01 and leaf02 are the access layer switches on the network. leaf01 and leaf02 connect to spine01, which is the aggregation layer switch on the network. To facilitate additional configuration after the initial setup descibed in this guide, leaf01 and leaf02 also have two connections to each other.Follow the steps below to:Create three VMs (leaf01, leaf02, and spine01) and the network connections between themLog in to the switchesPerform basic switch configurationVerify configurationThese steps were tested with Cumulus VX 4.2, KVM/QEMU version 1:4.2-3ubuntu6.3, and Libvirt version 6.0.0 on Ubuntu Linux version 20.04.Create and Configure the VMsThe following procedure creates leaf01, leaf02, and spine01 and the network connections between them. This section assumes you have Linux and KVM experience.Download and Install the SoftwareDownload the Cumulus VX Qcow2 image for KVM.Run the following commands to install KVM, QEMU and Libvirt:local@host:~$ sudo apt update -ylocal@host:~$ sudo apt install -qy qemu ebtables dnsmasq-base qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils virt-manager python3-piplocal@host:~$ sudo apt install -qy libxslt-dev libxml2-dev libvirt-dev zlib1g-devConfirm that your Linux kernel and BIOS settings permit the use of KVM hardware acceleration:local@host:~$ kvm-okINFO: /dev/kvm existsKVM acceleration can be usedCreate the VMs and Network ConnectionsCopy the qcow2 image onto a Linux server three times to create the three VMs. Name them as follows:leaf01.qcow2leaf02.qcow2spine01.qcow2Run the following commands to configure each VM. Make sure you specify the location of

3.2. libvirt and libvirt Tools

For generic KVM servers with libvirt, Alt Server-V, OpenStack, OpenNebula and any other virtualization environments based on them. To save a memory dump in ELF format to the KVM host, run as root: sudo virsh dump --memory-only All virsh commands can be run without sudo, if the user is in libvirt group To save a dump in Windows crashdump format, VM has to have latest virtio-win drivers installed and vmcoreinfo feature has to be enabled in VM's configuration file: export VMID=; export xml_path="/etc/libvirt/qemu/$VMID.xml"; sudo grep vmcoreinfo $xml_path; if [ $? -ne 0 ]; virsh shutdown $VMID; sudo systemctl stop libvirtd; then sudo sed -i "s//&\n /" $xml_path; sudo systemctl start libvirtd; sudo virsh start $VMID; fi; After VM boots up (or crashes), run the following to create the dump: sudo virsh qemu-monitor-command dump-guest-memory -w file> Check dump file size, if it is 0 bytes, it means that the VM couldn't load the vmcoreinfo driver and the only way is to create an ELF dump Copy the dump from the node, one way it can be done is by using scp: scp @: Citrix Hypervisor The only way to capture a memory dump in a virtual machine running on Citrix Hypervisor is to use memory dump mechanisms built into the guest OS, but a crash of the guest can be triggered from the hypervisor by running:. libvirt-clients Programs for the libvirt library libvirt-clients-qemu Programs for the libvirt library (QEMU specific) libvirt-common data files for the libvirt library libvirt-daemon Virtualization daemon libvirt-daemon-common Virtualization daemon common files libvirt-daemon-config-network Libvirt daemon configuration files (default network)

Module libvirt-stream from libvirt

Communicate with libvirt using libvirt-lxc to launch containers was a good idea. There were serious concerns with this approach. Consider the following example of starting a container with the Docker client (docker-cli) and the layers of calls before the container process (pid1OfContainer) is started:docker-cli → docker-daemon → libvirt-lxc → pid1OfContainerI did not like the idea of having two daemons between your tool to launch containers and the final running container.My team worked hard with the upstream docker developers on a native Go programming language implementation of the container runtime, called libcontainer. This library eventually got released as the initial implementation of the OCI Runtime Specification along with runc.docker- cli → docker-daemon @ pid1OfContainerAlthough most people mistakenly think that when they execute a container, the container process is a child of the docker-cli, they actually have executed a client/server operation and the container process is running as a child of a totally separate environment. This client/server operation can lead to instability and potential security concerns, and it blocks useful features. For example, systemd has a feature called socket activation, where you can set up a daemon to run only when a process connects to a socket. This means your system uses less memory and only has services executing when they are needed. The way socket activation works is systemd listens at a TCP socket, and when a packet arrives for the socket, systemd activates the service that normally listens on the socket. Once the service is activated, systemd hands the socket Apt install qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils virtinst libvirt-daemon virt-manager -yDone? Great. You should now have the Virtual Machine Manager in your app launcher. The last step is to install Manjaro but to do that, we need a disk image. Head over to the Manjaro website and grab the 64-bit download. You can grab the full installation like me or the minimal desktop setup if you don’t want a lot of extra software installed. The best part about this setup is that you will actually have the option to run Manjaro as a live image which means you can test out the desktop environment before you actually install it on your machine. Once you have it downloaded, open your Files app and move it to the Linux folder. That will make it easier when it comes time to install the image. Head to your app launcher and fire up the Virtual Machine Manager. Click on the icon below the File menu to create a new VM. Shop Best Chromebooks of 2020 So Far on Chrome ShopSelect “Local install media” and click forward. Then, click “browse” and “browse local” to find the .iso image for Manjaro. It should open to the Linux folder and be right there for you to grab. Under the “operating system you are installing,” deselect auto detect and type “generic” to find the generic OS option. Select that and click forward. Now you will alot RAM and CPU cores. I opted for 6GB of RAM and all four

Module libvirt-host from libvirt

Dock-Droid · Follow @sickcodes on TwitterDocker Android - Run QEMU Android x86 and Android ARM in a Docker! X11 Forwarding! CI/CD for Android!CapabilitiesSecurity Research of ARM apps on x86!ADB on port :5555Magisk, riru, LSPosed on Android x86SSH enabled (localhost:50922)SCRCPY enabled (localhost:5555)WebCam forwarding enabled (/dev/video0)Audio forwarding enabled (/dev/snd)GPU passthrough (/dev/dri)X11 forwarding is enabledruns on top of QEMU + KVMsupports BlissOS, custom images, VDI files, any Android x86 image, Xvfb headless modeyou can clone your container with docker commitAuthorThis project is maintained by @sickcodes Sick.Codes. (Twitter)Additional credits can be found here: thanks to @BlissRoms who maintain absolutely incredible Android x86 images. If you love their images, consider donating to the project: thanks to @zhouziyang who maintains an even more native fork Redroid!This project is heavily based on Docker-OSX: Generation Anbox Style LXC: in a Docker using BlissOS: and ashmem for use in anbox related 5.7+ Kernel distribuitons (soon to be all): disk space for bare minimum installationvirtualization should be enabled in your BIOS settingsa kvm-capable host (not required, but slow otherwise)Initial setupBefore you do anything else, you will need to turn on hardware virtualization in your BIOS. Precisely how will depend on your particular machine (and BIOS), but it should be straightforward.Then, you'll need QEMU and some other dependencies on your host:# ARCHsudo pacman -S qemu libvirt dnsmasq virt-manager bridge-utils flex bison iptables-nft edk2-ovmf# UBUNTU DEBIANsudo apt install qemu qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils virt-manager# CENTOS RHEL FEDORAsudo yum install libvirt qemu-kvmThen, enable libvirt and load the KVM kernel module:sudo systemctl enable --now libvirtdsudo systemctl enable --now virtlogdecho 1 | sudo tee /sys/module/kvm/parameters/ignore_msrssudo modprobe kvmQuick Start Dock-DroidYou can run the Live OS image, or install to disk.Connect to the WiFi network called VirtWifi.BlissOS x86 Image docker run -it \ --device /dev/kvm \ -v /tmp/.X11-unix:/tmp/.X11-unix \ -e "DISPLAY=${DISPLAY:-:0.0}" \ -p 5555:5555 \ sickcodes/dock-droid:latestHeadlessly (on a server, or locally)docker run -it \ --device /dev/kvm \ -e EXTRA="-display none -vnc 0.0.0.0:99,password=on" \ -p 5555:5555 \ -p 5999:5999 \ sickcodes/dock-droid:latestFor headless, in the QEMU console, type change vnc password userAnd then connect on localhost:5999, or the server IP, or Docker IP.No Image (:naked) docker run -it \ --device /dev/kvm \ -v /tmp/.X11-unix:/tmp/.X11-unix \ -e "DISPLAY=${DISPLAY:-:0.0}" \ -v "${PWD}/android.qcow2:/home/arch/dock-droid/android.qcow2" \ -p 5555:5555 \ sickcodes/dock-droid:nakedRun without KVM (Work in Progress)This will boot, but currently does not "work".Change CPU to Penryn, which is normally hostChange ENABLE_KVM, which is normally -enable-kvmChange KVM, which is normally accel=kvm:tcgChange CPUID_FLAGS, which is normally very long.# use a spacebar in quotes-e CPU=qemu64 \-e ENABLE_KVM=' ' \-e KVM=' ' \-e CPUID_FLAGS=' ' \For example (Work in Progress):docker run -it \ -e CPU=Penryn \ -e ENABLE_KVM=' ' \ -e KVM=' ' \ -e CPUID_FLAGS=' ' \ -v /tmp/.X11-unix:/tmp/.X11-unix \ -e "DISPLAY=${DISPLAY:-:0.0}" \ -p 5555:5555 \ sickcodes/dock-droid:latestIncrease RAMIncrease

Module libvirt-common from libvirt

Commands to install WebVirtCloud on Ubuntu 20.04 to provide KVM with a web-based graphical user interface.WebVirtCloud is a free and open-source project that offers a GUI web interface for the command-line KVM virtualization of Linux systems. Well, if you don’t know about the KVM – stands for Kernel Virtual Machine. It is a Type-1 Hypervisor that uses the kernel of Linux to offer the virtualization environment. Whereas VirtualBox and Vmware Workstation are Type-2 hypervisors where the Guest OS doesn’t have direct as to hardware.An advantage of KVM is that the guest systems run at almost native speeds, i.e. the guest system responds almost as quickly as a native system.To manage and communicate KVM using the tools like Virt Manager we required Libvirt, a virtualization management layer. The same Libvirt API is used by the WebVirtCloud web UI to manage KVM.It can delegate Virtual Machines to users. A noVNC viewer presents a full graphical console to the guest domain. KVM is currently the only hypervisor supported. Although RedHat’s Virt-Manager is already a great GUI option to connect KVM, however, the user needs to access the server physically or over an SSH session. However, this can bypass using WebVirtCloud, a python-based software still in its initial stage of development. It offers an easy-to-understand interface that can be used to create, deploy, manage, and delete virtual machines running on a remote server using the local browser.Features:• QEMU/KVM Hypervisor and Instance Management• Get Instance status• Manage Multiple QEMU/KVM Hypervisor, Datastore pools, Networks• User-Based Authorization and Authentication• Instance Console Access with Browsers• Libvirt API-based web management UI• Supports cloud-init Datasource interface• Users can add SSH public key to root in Instance and can change root password in Instances.Steps to install WebVirtCloud on Ubuntu 20.041. Requirements• Debian based Ubuntu system• Virtualization-supported hardware• A non-root user with sudo rights• Terminal Access• Internet Connection2. Run system update using DNFIt is good to run the system update command on your system before installing any software, this reduces the chances of errors caused by the old packages.sudo dnf update && sudo dfn upgrade3. Install KVM on Ubuntu 2004Well, if you already have KVM enabled on your Ubuntu 20.04 then you don’t need to follow this step. Move to the next one. However, if you don’t have one, then of course go through all the given commands:Check Virtualization supported by your CPUcat /proc/cpuinfo | egrep "vmx|svm"If the Hardware virtualization is enabled then for Intel CPU you will get VMX in the result and for AMD – it will be SVM.Next, Install KVMsudo apt install qemu qemu-kvm libvirt-daemon bridge-utils virt-manager virtinst -yStart & Enable KVM service:sudo systemctl enable --now libvirtd4. Script to install WebVirtCloud on Ubuntu 20.04 LTSThere are a few packages. libvirt-clients Programs for the libvirt library libvirt-clients-qemu Programs for the libvirt library (QEMU specific) libvirt-common data files for the libvirt library libvirt-daemon Virtualization daemon libvirt-daemon-common Virtualization daemon common files libvirt-daemon-config-network Libvirt daemon configuration files (default network)

Module libvirt-secret from libvirt

Hardware platform, which is much slower than hardware-assisted virtualization.2. What is the purpose of libvirt in KVM/QEMU?Libvirt is a toolkit and API used to manage virtualization platforms. It abstracts the management of VMs, networks, storage, and other resources. It simplifies managing KVM and QEMU through command-line tools (like virsh) or graphical tools like virt-manager.3. What is the difference between a full virtualization and para-virtualization in KVM/QEMU?Full virtualization: The guest OS is unaware it is running on a virtualized system. KVM provides complete isolation from the host system and simulates the entire hardware environment.Para-virtualization: The guest OS is modified to be aware that it’s running in a virtualized environment. It communicates directly with the hypervisor (KVM) for improved performance.ConclusionBoth QEMU and KVM are powerful virtualization technologies, each with unique strengths and weaknesses. If you need cross-platform support, flexibility, and ease of use, QEMU might be better suited for your virtualization needs. On the other hand, if performance, efficiency, and seamless integration with Linux are your priorities, KVM is a highly suitable choice. Ultimately, the decision between QEMU and KVM depends on your specific requirements, workload characteristics, and familiarity with Linux systems.