nova/releasenotes/notes/hide_hypervisor_id-6f93e7552336930d.yaml
Daniel Pawlik c7c08e590e Add img_hide_hypervisor_id image property
Image hide_hypervisor_id property helps libvirt set an xml instance file
property, which will hide on guest host KVM hypervisor signature
("KVMKVMKVM\0\0\0").
According to the commit message in QEMU repository [1]:

"The latest Nvidia driver (337.88) specifically checks
for KVM as the hypervisor and reports Code 43 for the
driver  in a Windows guest when found.  Removing or
changing the KVM signature is sufficient for the driver
to load and work."

DocImpact: New feature ``img_hide_hypervisor_id`` image property should be
added in the glance-property-keys page of the cli-reference docs [2].

[1]: http://git.qemu.org/?p=qemu.git;a=commitdiff;h=f522d2a
[2]: https://docs.openstack.org/cli-reference/glance-property-keys.html

Implements: blueprint add-kvm-hidden-feature

Co-Authored-By: Adam Kijak <adam.kijak@corp.ovh.com>

Change-Id: Ie8227fececa40e502aaa39d77de2a1cd0cd72682
2017-05-29 16:03:43 +00:00

33 lines
1.2 KiB
YAML

---
features:
- |
Some hypervisors add a signature to their guests, e.g. KVM is adding
``KVMKVMKVM\0\0\0``, Xen: ``XenVMMXenVMM``.
The existence of a hypervisor signature enables some paravirtualization
features on the guest as well as disallowing certain drivers which test
for the hypervisor to load e.g. Nvidia driver [1]:
"The latest Nvidia driver (337.88) specifically checks
for KVM as the hypervisor and reports Code 43 for the
driver in a Windows guest when found. Removing or
changing the KVM signature is sufficient for the driver
to load and work."
The new ``img_hide_hypervisor_id`` image metadata property hides the
hypervisor signature for the guest.
Currently only the libvirt compute driver can hide hypervisor signature
for the guest host.
To verify if hiding hypervisor id is working on Linux based system::
$ cpuid | grep -i hypervisor_id
The result should not be (for KVM hypervisor)::
$ hypervisor_id = KVMKVMKVM\0\0\0
You can enable this feature by setting the ``img_hide_hypervisor_id=true``
property in a Glance image.
[1]: http://git.qemu.org/?p=qemu.git;a=commitdiff;h=f522d2a