Combination of 'hw_video_ram' image metadata prop, 'hw_video:ram_max_mb' extra spec raises error

[Stephen Finucane]

The 'hw_video_ram' image metadata property is used to configure the amount of memory allocated to VRAM. Using it requires specifying the 'hw_video:ram_max_mb' extra spec or you'll get the following error:

  nova.exception.RequestedVRamTooHigh: The requested amount of video memory 8 is higher than the maximum allowed by flavor 0.

However, specifying these currently results in a libvirt failure.

  ERROR nova.compute.manager [None ...] [instance: 11a71ae4-e410-4856-aeab-eea6ca4784c5] Failed to build and run instance: libvirt.libvirtError: XML error: cannot parse video vram '8192.0'
  ERROR nova.compute.manager [instance: ...] Traceback (most recent call last):
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/compute/manager.py", line 2333, in _build_and_run_instance
  ERROR nova.compute.manager [instance: ...] accel_info=accel_info)
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 3632, in spawn
  ERROR nova.compute.manager [instance: ...] cleanup_instance_disks=created_disks)
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 6527, in _create_domain_and_network
  ERROR nova.compute.manager [instance: ...] cleanup_instance_disks=cleanup_instance_disks)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
  ERROR nova.compute.manager [instance: ...] self.force_reraise()
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
  ERROR nova.compute.manager [instance: ...] six.reraise(self.type_, self.value, self.tb)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/six.py", line 703, in reraise
  ERROR nova.compute.manager [instance: ...] raise value
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 6496, in _create_domain_and_network
  ERROR nova.compute.manager [instance: ...] post_xml_callback=post_xml_callback)
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 6425, in _create_domain
  ERROR nova.compute.manager [instance: ...] guest = libvirt_guest.Guest.create(xml, self._host)
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/virt/libvirt/guest.py", line 127, in create
  ERROR nova.compute.manager [instance: ...] encodeutils.safe_decode(xml))
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
  ERROR nova.compute.manager [instance: ...] self.force_reraise()
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
  ERROR nova.compute.manager [instance: ...] six.reraise(self.type_, self.value, self.tb)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/six.py", line 703, in reraise
  ERROR nova.compute.manager [instance: ...] raise value
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/virt/libvirt/guest.py", line 123, in create
  ERROR nova.compute.manager [instance: ...] guest = host.write_instance_config(xml)
  ERROR nova.compute.manager [instance: ...] File "/opt/stack/nova/nova/virt/libvirt/host.py", line 1135, in write_instance_config
  ERROR nova.compute.manager [instance: ...] domain = self.get_connection().defineXML(xml)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/eventlet/tpool.py", line 190, in doit
  ERROR nova.compute.manager [instance: ...] result = proxy_call(self._autowrap, f, *args, **kwargs)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/eventlet/tpool.py", line 148, in proxy_call
  ERROR nova.compute.manager [instance: ...] rv = execute(f, *args, **kwargs)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/eventlet/tpool.py", line 129, in execute
  ERROR nova.compute.manager [instance: ...] six.reraise(c, e, tb)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/six.py", line 703, in reraise
  ERROR nova.compute.manager [instance: ...] raise value
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/eventlet/tpool.py", line 83, in tworker
  ERROR nova.compute.manager [instance: ...] rv = meth(*args, **kwargs)
  ERROR nova.compute.manager [instance: ...] File "/usr/local/lib/python3.6/dist-packages/libvirt.py", line 3703, in defineXML
  ERROR nova.compute.manager [instance: ...] if ret is None:raise libvirtError('virDomainDefineXML() failed', conn=self)
  ERROR nova.compute.manager [instance: ...] libvirt.libvirtError: XML error: cannot parse video vram '8192.0'
  ERROR nova.compute.manager [instance: ...]

This appears to be a Python 3 thing, introduced by division of ints now returning a float.

Steps to reproduce:

1. Set the 'hw_video_ram' image metadata property on an image:

   $ openstack image set --property hw_video_ram=8 $IMAGE

2. Set the 'hw_video:ram_max_mb' flavor extra spec on a flavor:

   $ openstack flavor update --property hw_video:ram_max_mb=16384 $FLAVOR

3. Create a server using this flavor and image:

   $ openstack server create --image $IMAGE --flavor $FLAVOR ... test-server

Expected result:

Instance should be created with 8MB of VRAM.

Actual result:

Instance fails to create.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/753011

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/753011
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=f2ca089bce842127e7d0644b38a11da9278db8ea
Submitter: Zuul
Branch: master

commit f2ca089bce842127e7d0644b38a11da9278db8ea
Author: Stephen Finucane <email address hidden>
Date: Mon Sep 21 16:11:38 2020 +0100

    libvirt: 'video.vram' property must be an integer

    The 'vram' property of the 'video' device must be an integer else
    libvirt will spit the dummy out, e.g.

      libvirt.libvirtError: XML error: cannot parse video vram '8192.0'

    The division operator in Python 3 results in a float, not an integer
    like in Python 2. Use the truncation division operator instead.

    Change-Id: Iebf678c229da4f455459d068cafeee5f241aea1f
    Signed-off-by: Stephen Finucane <email address hidden>
    Closes-Bug: #1896496

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/victoria
Review: https://review.opendev.org/757616

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ussuri
Review: https://review.opendev.org/757617

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/train
Review: https://review.opendev.org/757618

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/757616
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=fd7c66f61c0b07cff82d93e0f884777949170857
Submitter: Zuul
Branch: stable/victoria

commit fd7c66f61c0b07cff82d93e0f884777949170857
Author: Stephen Finucane <email address hidden>
Date: Mon Sep 21 16:11:38 2020 +0100

    libvirt: 'video.vram' property must be an integer

    The 'vram' property of the 'video' device must be an integer else
    libvirt will spit the dummy out, e.g.

      libvirt.libvirtError: XML error: cannot parse video vram '8192.0'

    The division operator in Python 3 results in a float, not an integer
    like in Python 2. Use the truncation division operator instead.

    Change-Id: Iebf678c229da4f455459d068cafeee5f241aea1f
    Signed-off-by: Stephen Finucane <email address hidden>
    Closes-Bug: #1896496
    (cherry picked from commit f2ca089bce842127e7d0644b38a11da9278db8ea)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 23.0.0.0rc1 release candidate.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/nova/+/757617
Committed: https://opendev.org/openstack/nova/commit/121e481a880b48ce800aafdeca0b8b086e2cddf3
Submitter: "Zuul (22348)"
Branch: stable/ussuri

commit 121e481a880b48ce800aafdeca0b8b086e2cddf3
Author: Stephen Finucane <email address hidden>
Date: Mon Sep 21 16:11:38 2020 +0100

    libvirt: 'video.vram' property must be an integer

    The 'vram' property of the 'video' device must be an integer else
    libvirt will spit the dummy out, e.g.

      libvirt.libvirtError: XML error: cannot parse video vram '8192.0'

    The division operator in Python 3 results in a float, not an integer
    like in Python 2. Use the truncation division operator instead.

    Change-Id: Iebf678c229da4f455459d068cafeee5f241aea1f
    Signed-off-by: Stephen Finucane <email address hidden>
    Closes-Bug: #1896496
    (cherry picked from commit f2ca089bce842127e7d0644b38a11da9278db8ea)
    (cherry picked from commit fd7c66f61c0b07cff82d93e0f884777949170857)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/nova/+/757618
Committed: https://opendev.org/openstack/nova/commit/06b8f1467dc80203098de983cfc335b898440573
Submitter: "Zuul (22348)"
Branch: stable/train

commit 06b8f1467dc80203098de983cfc335b898440573
Author: Stephen Finucane <email address hidden>
Date: Mon Sep 21 16:11:38 2020 +0100

    libvirt: 'video.vram' property must be an integer

    The 'vram' property of the 'video' device must be an integer else
    libvirt will spit the dummy out, e.g.

      libvirt.libvirtError: XML error: cannot parse video vram '8192.0'

    The division operator in Python 3 results in a float, not an integer
    like in Python 2. Use the truncation division operator instead.

    Change-Id: Iebf678c229da4f455459d068cafeee5f241aea1f
    Signed-off-by: Stephen Finucane <email address hidden>
    Closes-Bug: #1896496
    (cherry picked from commit f2ca089bce842127e7d0644b38a11da9278db8ea)
    (cherry picked from commit fd7c66f61c0b07cff82d93e0f884777949170857)
    (cherry picked from commit 121e481a880b48ce800aafdeca0b8b086e2cddf3)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 21.2.1 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 20.6.1 release.