Where is qemu kvm

Releases prior to Karmic 9. After the installation, you need to relogin so that your user becomes an effective member of kvm and libvirtd user groups. Create a new virtual machine by pressing the top left Create a new virtual machine toolbar button.

Version-specific Notes 8. Ubuntu-virt-server installs the packages needed to setup a base virtulization host kvm, libvirt-bin and openssh-server and ubuntu-virt-mgmt installs what you need to administer it from a management station virt-manager, python-vm-builder and virt-viewer. You can optionally specify the dimensions of the virtual console:. The command creates a new virtual console called vc1 of the specified size, and connects the QEMU monitor to it.

The path is required and will be created if it does not exist. You can, however, create your own character devices and use them for just mentioned purposes. The following options will help you:. By default, it is a virtual console vc in graphical mode, and stdio in non-graphical mode. The -serial understands many suboptions. See the manual page man 1 qemu-kvm for their complete list.

You can emulate up to 4 serial ports. Use -serial none to disable all serial ports. Redirects the VM Guest's parallel port to a device. This option supports the same devices as -serial. You can emulate up to 3 parallel ports. Use -parallel none to disable all parallel ports. By default, it is a virtual console vc in a graphical mode, and stdio in non-graphical mode. For a complete list of available character devices back-ends, see the man page man 1 qemu-kvm.

Use the -net option to define a network interface and a specific type of networking for your VM Guest. Currently, SUSE supports the following options: none , nic , user , bridge , and tap. For a complete list of -net suboptions, see the manual page man 1 qemu-kvm. Disables a network card emulation on VM Guest. Only the loopback lo network interface is available.

Uses a specified network helper to configure the TAP interface and attach it to a specified bridge. For more information, see Section Specifies a user-mode networking. Specifies a bridged or routed networking. Connects the network interface to VLAN number 1. You can specify your own number, it is mainly useful for identification purpose.

If you omit this suboption, QEMU uses the default 0. It is a unique identifier and you are advised to always specify it. Specifies the model of the network card. Currently, SUSE supports the models rtl and virtio. The -net user option instructs QEMU to use a user-mode networking. This is the default if no networking mode is selected. Therefore, these command lines are equivalent:. This mode is useful if you want to allow the VM Guest to access the external network resources, such as Internet.

By default, no incoming traffic is permitted and therefore, the VM Guest is not visible to other machines on the network. No administrator privileges are required in this networking mode.

You can use ssh to connect to VM Host Server at Specifies a human readable name of the network stack. Useful when identifying it in the QEMU monitor. Isolates VM Guest. It will not be able to communicate with VM Host Server and no network packets will be routed to the external network.

Default is Broadcasts the specified file as a BOOTP a network protocol which offers an IP address and a network location of a boot image, often used in diskless workstations file. When used together with tftp , the VM Guest can boot from network from the local directory on the host. If sshd is running on VM Guest, enter.

Its network interface is then visible to the rest of the network. This method does not work by default and has to be explicitly specified. First, create a network bridge and add a VM Host Server physical network interface usually eth0 to it:. Click Next. Choose whether you need a dynamically or statically assigned IP address, and fill the related network settings if applicable.

In the Bridged Devices pane, select the Ethernet device to add to the bridge. When asked about adapting an already configured device, click Continue. Click OK to apply the changes.

Check if the bridge is created:. Use the following example script to connect VM Guest to the newly created bridge interface br0.

Several commands in the script are run via the sudo mechanism because they require root privileges. Make sure the tunctl and bridge-utils packages are installed on the VM Host Server. If not, install them with zypper in tunctl bridge-utils.

The guest state has its own set of ring states, but privileged ring0 instructions fall back to the hypervisor code. Since it is a new processor mode of execution, the code doesn't have to be modified in any way.

Apart from the processor state switching, the kernel module also handles a few low-level parts of the emulation like the MMU registers used to handle VM and some parts of the PCI emulated hardware.

Second, KVM is a fork of the Qemu executable. Both teams work actively to keep differences at a minimum, and there are advances in reducing it. Eventually, the goal is that Qemu should work anywhere, and if a KVM kernel module is available, it could be automatically used. But for the foreseeable future, the Qemu team focuses on hardware emulation and portability, while KVM folks focus on the kernel module sometimes moving small parts of the emulation there, if it improves performance , and interfacing with the rest of the userspace code.

The kvm-qemu executable works like normal Qemu: allocates RAM, loads the code, and instead of recompiling it, or calling KQemu, it spawns a thread this is important. On a privileged instruction, it switches back to the KVM kernel module, which, if necessary, signals the Qemu thread to handle most of the hardware emulation.

One of the nice things of this architecture is that the guest code is emulated in a posix thread which you can manage with normal Linux tools. If you want a VM with 2 or 4 cores, kvm-qemu creates 2 or 4 threads, each of them calls the KVM kernel module to start executing. The concurrency—if you have enough real cores—or scheduling—if not—is managed by the normal Linux scheduler, keeping code small and surprises limited.

KVM is a kernel module which allows passing through CPU cores via host-passthrough without virtualizing them. It also allows passing through PCI devices via vfio-pci kernel module. All these passthrough functionality are possible via IOMMU Input output memory mapping unit , which maps real DMA addresses to virtualized addresses so direct access becomes possible and it brings bare-metal native performance.

Libvirt is a library, allowing you to use python and other programming languages to configure virtual machines. Virsh is a toolkit which works in terminal to monitor and configure virtual machine settings. Qemu-img is a cli tool which creates, converts, snapshots disk images.

Virtio is the iommu access driver and method name to disks, NICs ethernet and video. KVM is a Linux kernel module. But what is full virtualization, you may ask? As you can imagine this has a massive performance impact. As previously mentioned, QEMU can run independently, but due to the emulation being performed entirely in software it is extremely slow.

So to conclude: QEMU is a type 2 hypervisor that runs within user space and performs virtual hardware emulation, whereas KVM is a type 1 hypervisor that runs in kernel space, that allows a user space program access to the hardware virtualization features of various processors. However, this has now been merged into QEMU upstream and the fork has now been discontinued.

Or in other words, as per Linux KVM,.