Bug 2109621

Summary:	Nova fails to reuse mdev vgpu devices
Product:	Red Hat OpenStack	Reporter:	Sylvain Bauza <sbauza>
Component:	openstack-nova	Assignee:	OSP DFG:Compute <osp-dfg-compute>
Status:	CLOSED UPSTREAM	QA Contact:	OSP DFG:Compute <osp-dfg-compute>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	17.0 (Wallaby)	CC:	alifshit, dasmith, egallen, eglynn, jhakimra, kchamart, mburns, osp-dfg-compute, pgrist, sbauza, sgordon, vromanso
Target Milestone:	---	Keywords:	Regression, Triaged
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
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Fixed In Version:		Doc Type:	If docs needed, set a value
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Last Closed:	2023-05-16 17:17:04 UTC	Type:	Bug
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Documentation:	---	CRM:
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2109450
Bug Blocks:

Description Sylvain Bauza 2022-07-21 15:59:05 UTC

Description of problem:

Due to some breaking change in libvirt on 8.0.0 or earlier, now nova isn't able to see the mdevs it created, leading to some capacity leaking for vGPUs.

A better explanation of the impact can be found in https://bugs.launchpad.net/nova/+bug/1981631

A libvirt bug report was created against this regression : https://bugzilla.redhat.com/show_bug.cgi?id=2109450

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Create an instance with a VGPU flavor
2. Inventory of the RP will have a 'total' value reducing by 1.

Actual results:


Expected results:
Inventory "total" value shouldn't change.

Additional info:

Comment 5 Artom Lifshitz 2023-05-16 17:17:04 UTC

https://bugzilla.redhat.com/show_bug.cgi?id=2109616 is the bug used to track Nova's work to handle libvirt renaming mdev devices in RHEL 9.2.

This BZ, while related, is for a different thing, and is tracked as a Opinion upstream, with a patch at https://review.opendev.org/c/openstack/nova/+/858012, which isn't getting much traction for now. Let's close this as UPSTREAM for now.