Add documentation for Instance setting for machine type on KVM

Author: nvazquez

source/adminguide/virtual_machines.rst

@@ -1169,6 +1169,11 @@ An example list of settings as well as their possible values are shown on the im
 |vm-settings-kvm-guest-cpu-model.png|
 (KVM guest CPU model, available for root admin since 4.20.1.0)
 
+CloudStack supports setting the guest machine type for KVM instances since 4.22.0 by the Instance setting 'kvm.guest.os.machine.type'. The list of supported machine types will depend on the QEMU version on the Instance KVM host.
+
+.. note::
+   For Ubuntu 24 KVM hosts (and other distros containing QEMU 8.x versions) setting the machine type for Windows VMs to 'pc-i440fx-8.0' mitigates an issue in which the instance UUID could not be obtained from within the guest VM through the command: `wmic path win32_computersystemproduct get uuid`.
+
 Instance Settings for Virtual Trusted Platform Module (vTPM)
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