Bug 1731918

Summary:	[libvirt] Safe mechanism for updating CPU models
Product:	Red Hat Enterprise Virtualization Manager	Reporter:	Jaroslav Suchanek <jsuchane>
Component:	vdsm	Assignee:	Nobody <nobody>
Status:	CLOSED DEFERRED	QA Contact:	Lukas Svaty <lsvaty>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	chhu, dyuan, ehabkost, jdenemar, kchamart, lsurette, mvanderw, srevivo, xuzhang, yalzhang, ycui
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:	1727122	Environment:
Last Closed:	2021-09-29 11:33:06 UTC	Type:	---
Regression:	---	Mount Type:	---
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oVirt Team:	Virt	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1697663, 1727122
Bug Blocks:

Description Jaroslav Suchanek 2019-07-22 11:56:03 UTC

+++ This bug was initially created as a clone of Bug #1727122 +++

This bug was initially created as a copy of Bug #1697663

I am copying this bug because: 
Now that versioned CPU models are available in QEMU, we need libvirt APIs that will translate unversioned CPU model names (e.g. "Westmere", "Cascadelake-Server") to versioned names (e.g. "Westmere-v1", "Cascadelake-Server-v2").


Today, we have two limitations in the CPU model system in QEMU and libvirt:

* Updates to CPU models need to be coupled to machine-types, making CPU security updates more risky because they may bring unexpected ABI changes to VMs.

* New features may require updates to host hardware or software (e.g. CPU microcode updates and/or KVM module updates) and can't be added unconditionally to existing CPU models (otherwise existing VM configurations that are runnable may become not runnable).

We need management software to update CPU model configuration in VMs in a convenient way without the limitations above.

Comment 2 Michal Skrivanek 2021-08-20 08:27:15 UTC

This bug/RFE is more than 2 years old and it didn't get enough attention so far, and is now flagged as pending close. 
Please review if it is still relevant and provide additional details/justification/patches if you believe it should get more attention for the next oVirt release.

Comment 3 Michal Skrivanek 2021-09-29 11:33:06 UTC

This bug didn't get any attention in a long time, and it's not planned in foreseeable future. oVirt development team has no plans to work on it.
Please feel free to reopen if you have a plan how to contribute this feature/bug fix.