20.2.2. Host Physical Machine Boot Loader

Hypervisors employing paravirtualization do not usually emulate a BIOS, but instead the host physical machine is responsible for the operating system boot. This may use a pseudo-bootloader in the host physical machine to provide an interface to choose a kernel for the guest virtual machine. An example is pygrub with Xen.
 ...
  <bootloader>/usr/bin/pygrub</bootloader>
  <bootloader_args>--append single</bootloader_args>
  ...

Figure 20.3. Host physical machine boot loader domain XML

The components of this section of the domain XML are as follows:

Table 20.3. BIOS boot loader elements

ElementDescription
<bootloader>provides a fully qualified path to the boot loader executable in the host physical machine OS. This boot loader will choose which kernel to boot. The required output of the boot loader is dependent on the hypervisor in use.
<bootloader_args>allows command line arguments to be passed to the boot loader (optional command)