libvirt
Virtual Machine Manager's
view offers in-depth information about the VM Guest's complete configuration and hardware equipment. Using this view, you can also change the guest configuration or add and modify virtual hardware. To access this view, open the guest's console in Virtual Machine Manager and either choose › from the menu, or click in the toolbar.
The left panel of the window lists VM Guest overview and already installed
hardware. After clicking an item on the list, you can access its detailed
settings in the details view. You can change the hardware parameters to
match your needs, then click virt-manager
warns you about
that fact.
To remove installed hardware from a VM Guest, select the appropriate list entry in the left panel and then click
in the bottom right of the window.To add new hardware, click
below the left panel, then select the type of the hardware you want to add in the window. Modify its parameters and confirm with .The following sections describe configuration options for the specific hardware type being added. They do not focus on modifying an existing piece of hardware, as the options are identical.
This section describes the setup of the virtualized processor and memory hardware. These components are vital to a VM Guest, therefore you cannot remove them. It also shows how to view the overview and performance information, and how to change boot parameters.
shows basic details about VM Guest and the hypervisor.
, , and are editable and help you identify VM Guest in the list of machines.
shows the universally unique identifier of the virtual machine, while shows its current status— , , or .
The
section shows the hypervisor type, CPU architecture, used emulator, and chipset type. None of the hypervisor parameters can be changed.shows regularly updated charts of CPU and memory usage, and disk and network I/O.
Not all the charts in the
view are enabled by default. To enable these charts, go to › , then select › › , and check the charts that you want to see regularly updated.includes detailed information about VM Guest processor configuration.
In the
section, you can configure the number of virtual CPUs allocated to the VM Guest. shows the number of online and usable CPUs on the VM Host Server.The
section lets you configure the CPU model and topology.
When activated, the virsh
capabilities
command. When deactivated, the CPU model needs
to be specified from the models available in the drop-down box.
The host CPU model provides a good trade-off between CPU
features and the ability to migrate the VM Guest. libvirt
does not model
every aspect of each CPU, so the VM Guest CPU does not match the
VM Host Server CPU exactly. But the ABI provided to the VM Guest is
reproducible and during migration the complete CPU model definition is
transferred to the destination VM Host Server, ensuring the migrated
VM Guest can see the exact same CPU model on the destination.
The host-passthrough
model provides the VM Guest
with a CPU that is exactly the same as the VM Host Server CPU. This can be
useful when the VM Guest workload requires CPU features not available
in libvirt
's simplified host-model
CPU. The
host-passthrough
model comes with the disadvantage
of reduced migration capability. A VM Guest with
host-passthrough
model CPU can only be migrated to a
VM Host Server with identical hardware.
For more information on libvirt
's CPU model and topology options, see
the CPU model and topology documentation at
https://libvirt.org/formatdomain.html#cpu-model-and-topology.
After you activate
, you can specify a custom number of sockets, cores and threads for the CPU.contains information about the memory that is available to VM Guest.
Total amount of memory installed on VM Host Server.
The amount of memory currently available to VM Guest. You can hotplug more memory by increasing this value up to the value of
.
Specify if the virtual machine can use shared memory via the
memfd
backed. It is a requirement for using
the virtiofs file system. Find more details
in
https://libvirt.org/kbase/virtiofs.html.
The maximum value to which you can hotplug the currently available memory. Any change to this value takes effect after the next VM Guest reboot.
If the VM Host Server supports AMD-SEV technology, activating this option enables a secured guest with encrypted memory. This option requires a virtual machine with chipset type Q35.
VM Guests with memory requirements of 4 TB or more must either
use the host-passthrough
CPU mode, or explicitly
specify the virtual CPU address size when using
host-model
or custom
CPU modes.
The default virtual CPU address size for these modes may not be
sufficient for memory configurations of 4 TB or more. The address size
can only be specified by editing the VM Guests XML configuration.
See Section 14.6, “Configuring memory allocation” for more
information on specifying virtual CPU address size.
introduces options affecting the VM Guest boot process.
In the
section, you can specify whether the virtual machine should automatically start during the VM Host Server boot phase.In the
, activate the devices used for booting VM Guest. You can change their order with the up and down arrow buttons on the right side of the list. To choose from a list of bootable devices on VM Guest start, activate .To boot a different kernel than the one on the boot device, activate
and specify the paths to the alternative kernel and initrd placed on the VM Host Server file system. You can also specify kernel arguments that are passed to the loaded kernel.This section gives you a detailed description of configuration options for storage devices. It includes both hard disks and removable media, such as USB or CD-ROM drives.
Below the left panel, click
to open the window. There, select .
To create a qcow2
disk image in the default
location, activate and specify its size in gigabytes.
To gain more control over the disk image creation, activate Section 8.2.2, “Managing storage with Virtual Machine Manager”.
and click to manage storage pools and images. The window opens, which has almost identical functionality as the tab described in
SUSE only supports the following storage formats:
raw
and qcow2
.
After you create and specify the disk image file, specify the
. It can be one of the following options:
: does not allow using .
: does not allow using .
: required to use an existing SCSI storage directly without adding it into a storage pool.
Select the
for your device. The list of available options depends on the device type you selected in the previous step. The types based on use paravirtualized drivers.In the Chapter 16, Disk cache modes.
section, select the preferred . For more information on cache modes, seeConfirm your settings with
. A new storage device appears in the left panel.This section focuses on adding and configuring new controllers.
Below the left panel, click
to open the window. There, select .Select the type of the controller. You can choose from
, , , , (paravirtualized), , or (smart card devices).Optionally, for a USB or SCSI controller, select a controller model.
Confirm your settings with
. A new controller appears in the left panel.This section describes how to add and configure new network devices.
Below the left panel, click
to open the window. There, select .From the Section 8.1, “Configuring networks” for more information on setting up virtual networks with Virtual Machine Manager.
list, select the source for the network connection. The list includes VM Host Server's available physical network interfaces, network bridges, or network bonds. You can also assign the VM Guest to an already defined virtual network. SeeSpecify a
for the network device. While Virtual Machine Manager pre-fills a random value for your convenience, it is recommended to supply a MAC address appropriate for your network environment to avoid network conflicts.Select a device model from the list. You can either leave the virtio uses paravirtualized drivers.
, or specify one of , , or models.Confirm your settings with
. A new network device appears in the left panel.This section focuses on adding and configuring new input devices, such as a mouse, a keyboard or a tablet.
Below the left panel, click
to open the window. There, select .Select a device type from the list.
Confirm your settings with
. A new input device appears in the left panel.When you click within a VM Guest's console with the mouse, the pointer is captured by the console window and cannot be used outside the console unless it is explicitly released (by pressing Alt–Ctrl). To prevent the console from grabbing the key and to enable seamless pointer movement between host and guest instead, follow the instructions in Procedure 13.4, “Adding a new input device” to add an to the VM Guest.
Adding a tablet has the additional advantage of synchronizing the mouse pointer movement between VM Host Server and VM Guest when using a graphical environment on the guest. With no tablet configured on the guest, you may often see two pointers with one dragging behind the other.
This section describes how to add and configure new video devices.
Below the left panel, click
to open the window. There, select .Select a model from the drop-down box.
Only
and can be added as secondary video devices.Confirm your settings with
. A new video device appears in the left panel.USB devices that are connected to the client machine can be redirected to the VM Guest by using
.Below the left panel, click
to open the window. There, select .Select a device type from the list. Depending on your configuration, you can either select a
or a redirector.Confirm your settings with
. A new USB redirector appears in the left panel.Smartcard functionality can be added via the
element. A physical USB smartcard reader can then be passed through to the VM Guest.Virtual watchdog devices are also supported. They can be created via the
element. The model and the action of the device can be specified.QA virtual watchdog devices require a specific driver and daemon to be installed in the VM Guest. Otherwise, the virtual watchdog device does not work.
You can use the Host TPM device in the VM Guest by adding TPM functionality via the
element.The Host TPM can only be used in one VM Guest at a time.
KVM supports CD or DVD-ROMs in VM Guest either by directly accessing a
physical drive on the VM Host Server or by accessing ISO images. To create an
ISO image from an existing CD or DVD, use dd
:
>
sudo
dd if=/dev/CD_DVD_DEVICE of=my_distro.iso bs=2048
To add a CD/DVD-ROM device to your VM Guest, proceed as follows:
Double-click a VM Guest entry in the Virtual Machine Manager to open its console and switch to the
view with › .Click
and choose in the pop-up window.Change the
to .Select
.
To assign the device to a physical medium, enter the path to the
VM Host Server's CD/DVD-ROM device (for example,
/dev/cdrom
) next to
. Alternatively, use
to open a file browser and then click
to select the device. Assigning
the device to a physical medium is only possible when the Virtual Machine Manager
was started on the VM Host Server.
To assign the device to an existing image, click
to choose an image from a storage pool. If the Virtual Machine Manager was started on the VM Host Server, alternatively choose an image from another location on the file system by clicking . Select an image and close the file browser with .Save the new virtualized device with
.Reboot the VM Guest to make the new device available. For more information, see Section 13.11, “Ejecting and changing floppy or CD/DVD-ROM media with Virtual Machine Manager”.
Currently, KVM only supports the use of floppy disk images—using a
physical floppy drive is not supported. Create a floppy disk image from
an existing floppy using dd
:
>
sudo
dd if=/dev/fd0 of=/var/lib/libvirt/images/floppy.img
To create an empty floppy disk image, use one of the following commands:
>
sudo
dd if=/dev/zero of=/var/lib/libvirt/images/floppy.img bs=512 count=2880
>
sudo
mkfs.msdos -C /var/lib/libvirt/images/floppy.img 1440
To add a floppy device to your VM Guest, proceed as follows:
Double-click a VM Guest entry in the Virtual Machine Manager to open its console and switch to the
view with › .Click
and choose in the pop-up window.Change the
to .Choose
and click to choose an existing image from a storage pool. If Virtual Machine Manager was started on the VM Host Server, alternatively choose an image from another location on the file system by clicking . Select an image and close the file browser with .Save the new virtualized device with
.Reboot the VM Guest to make the new device available. For more information, see Section 13.11, “Ejecting and changing floppy or CD/DVD-ROM media with Virtual Machine Manager”.
Whether you are using the VM Host Server's physical CD/DVD-ROM device or an
ISO/floppy image: before you can change the media or image of an existing
device in the VM Guest, you first need to disconnect
the media from the guest.
Double-click a VM Guest entry in the Virtual Machine Manager to open its console and switch to the
view with › .Choose the Floppy or CD/DVD-ROM device and “eject” the medium by clicking .
To “insert” a new medium, click .
If using the VM Host Server's physical CD/DVD-ROM device, first change the media in the device (this may require unmounting it on the VM Host Server before it can be ejected). Then choose
and select the device from the drop-down box.If you are using an ISO image, choose
and select an image by clicking . When connecting from a remote host, you may only choose images from existing storage pools.Click
to finish. The new media can now be accessed in the VM Guest.You can directly assign host-PCI devices to guests (PCI pass-through). When the PCI device is assigned to one VM Guest, it cannot be used on the host or by another VM Guest unless it is reassigned. A prerequisite for this feature is a VM Host Server configuration as described in Important: Requirements for VFIO and SR-IOV.
The following procedure describes how to assign a PCI device from the host machine to a VM Guest using Virtual Machine Manager:
Double-click a VM Guest entry in the Virtual Machine Manager to open its console and switch to the
view with › .Click
and choose the category in the left panel. A list of available PCI devices appears in the right part of the window.From the list of available PCI devices, choose the one you want to pass to the guest. Confirm with
.
On a newer QEMU machine type (pc-i440fx-2.0 or higher) with
SLES 11 SP4 KVM guests, the
acpiphp
module is not
loaded by default in the guest. This module must be loaded to enable
hotplugging of disk and network devices. To load the module manually,
use the command modprobe acpiphp
. It is also
possible to autoload the module by adding install acpiphp
/bin/true
to the
/etc/modprobe.conf.local
file.
KVM guests using the QEMU Q35 machine type have a PCI topology
that includes a pcie-root
controller and seven
pcie-root-port
controllers. The
pcie-root
controller does not support hotplugging.
Each pcie-root-port
controller supports
hotplugging a single PCIe device. PCI controllers cannot be
hotplugged, so plan accordingly and add more
pcie-root-port
s for more than seven hotplugged
PCIe devices. A pcie-to-pci-bridge
controller can
be added to support hotplugging legacy PCI devices. See
https://libvirt.org/pci-hotplug.html for more
information about PCI topology between QEMU machine types.
Analogous to assigning host PCI devices (see Section 13.12, “Assigning a host PCI device to a VM Guest”), you can directly assign host USB devices to guests. When the USB device is assigned to one VM Guest, it cannot be used on the host or by another VM Guest unless it is reassigned.
To assign a host USB device to VM Guest using Virtual Machine Manager, follow these steps:
Double-click a VM Guest entry in the Virtual Machine Manager to open its console and switch to the
view with › .Click
and choose the category in the left panel. A list of available USB devices appears in the right part of the window.From the list of available USB devices, choose the one you want to pass to the guest. Confirm with
. The new USB device appears in the left pane of the view.To remove the host USB device assignment, click it in the left pane of the
view and confirm with .