Cloud Hypervisor is an open source Virtual Machine Monitor (VMM) that runs on top of KVM. The project focuses on exclusively running modern, cloud workloads, on top of a limited set of hardware architectures and platforms. Cloud workloads refers to those that are usually run by customers inside a cloud provider. For our purposes this means modern operating systems with most I/O handled by paravirtualised devices (i.e. virtio), no requirement for legacy devices, and 64-bit CPUs.
The libvirt Cloud Hypervisor (CH) driver is intended to be run as a session driver without privileges. The cloud-hypervisor binary itself should be setcap cap_net_admin+ep (in order to create tap interfaces). Though, system-wide connection URI is also supported.
Expected connection URI would be
ch:///session (local access to per-user instance) ch:///system (local access to system instance)
But all other transport modes are supported too (see documentation).
The CH driver comes with sane default values. However, during its initialization it reads a configuration file which offers system administrator or an user to override some of that default. The location of the file depends on the connection URI, as follows:
ch:///system |
/etc/libvirt/ch.conf |
ch:///session |
$XDG_CONFIG_HOME/libvirt/ch/ch.conf |
If $XDG_CONFIG_HOME is not set in the environment, it defaults to $HOME/.config.
The Cloud Hypervisor driver in libvirt is in its early stage under active development only supporting a limited number of Cloud Hypervisor features.
Firmware is from hypervisor-fw
Note: Only virtio devices are supported
<domain type='kvm'>
<name>cloudhypervisor</name>
<uuid>4dea22b3-1d52-d8f3-2516-782e98ab3fa0</uuid>
<os>
<type>hvm</type>
<kernel>hypervisor-fw</kernel>
</os>
<memory unit='G'>2</memory>
<devices>
<disk type='file'>
<source file='disk.raw'/>
<target dev='vda' bus='virtio'/>
</disk>
<interface type='ethernet'>
<model type='virtio'/>
</interface>
</devices>
<vcpu>2</vcpu>
</domain>