Blueprints hide-hypervisor-id-flavor-extra-spec [1] and
add-kvm-hidden-feature [2] allow hiding KVM's signature for guests,
which is necessary for Nvidia drivers to work in VMs with passthrough
GPUs. While this works well for linux guests on KVM, it doesn't work
for Windows guests.
For them, KVM emulates some HyperV features. With the
current implementation, KVM's signature is hidden, but HyperV's is not,
and Nvidia drivers don't work in Windows VMs.
This change generates an extra element in the libvirt xml for Windows
guests on KVM which obfuscates HyperV's signature too, controlled by the
existing image and flavor parameters (img_hide_hypervisor_id and
hide_hypervisor_id correspondingly). The extra xml element is
<vendor_id state='on' value='1234567890ab'/>
in features/hyperv.
[1] https://blueprints.launchpad.net/nova/+spec/hide-hypervisor-id-flavor-extra-spec
[2] https://blueprints.launchpad.net/nova/+spec/add-kvm-hidden-feature
Change-Id: Iaaeae9281301f14f4ae9b43f4a06de58b699fd68
Closes-Bug: 1779845
ca543438e1