Ctrl, VM: Require restart when socket count is reduced

[orelmisan]

What this PR does

Before this PR:
Currently, it is possible to reduce the sockets count of a VirtualMachine object.
Doing so causes the following steps to happen:

1. The VirtualMachineInstance is updated.
2. A migration is triggered.
3. The target virt-launcher pod is created according to the updated VMI.
4. The domain is migrated as-is.
5. On the target virt-launcher pod - the domain is updated to fit.

This works well for CPU hotplug, but is problematic for CPU hotunplug in several scenarios, for example:

1. When using dedicated CPUs
2. When using networkInterfaceMultiqueue: true

After this PR:
RestartRequired condition is added on the VM in case the socket count is reduced.
This will make sure the virt-launcher pod and the domain are aligned.

Fixes #

Why we need it and why it was done in this way

The following tradeoffs were made:

The following alternatives were considered:

Links to places where the discussion took place:

Special notes for your reviewer

Depends on #11836, please only review the last commit.

Checklist

This checklist is not enforcing, but it's a reminder of items that could be relevant to every PR.
Approvers are expected to review this list.

• Design: A design document was considered and is present (link) or not required
• PR: The PR description is expressive enough and will help future contributors
• Code: Write code that humans can understand and Keep it simple
• Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• Testing: New code requires new unit tests. New features and bug fixes require at least on e2e test
• Documentation: A user-guide update was considered and is present (link) or not required. You want a user-guide update if it's a user facing feature / API change.
• Community: Announcement to kubevirt-dev was considered

Release note

Restart of a VM is required when the CPU socket count is reduced

[kubevirt-bot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[lyarwood]

/cc

[xpivarc]

Please, create an bug issue as well so we keep a track of it.

[orelmisan]

Change: Rebase on top of #11836

[orelmisan]

Rebase

[fossedihelm]

Thank you

[jean-edouard]

/approve

[kubevirt-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jean-edouard

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• OWNERS [jean-edouard]

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[kubevirt-commenter-bot]

Required labels detected, running phase 2 presubmits:
/test pull-kubevirt-e2e-windows2016
/test pull-kubevirt-e2e-kind-sriov
/test pull-kubevirt-e2e-k8s-1.30-ipv6-sig-network
/test pull-kubevirt-e2e-k8s-1.28-sig-network
/test pull-kubevirt-e2e-k8s-1.28-sig-storage
/test pull-kubevirt-e2e-k8s-1.28-sig-compute
/test pull-kubevirt-e2e-k8s-1.28-sig-operator
/test pull-kubevirt-e2e-k8s-1.29-sig-network
/test pull-kubevirt-e2e-k8s-1.29-sig-storage
/test pull-kubevirt-e2e-k8s-1.29-sig-compute
/test pull-kubevirt-e2e-k8s-1.29-sig-operator

[acardace]

/cherrypick release-1.2

[kubevirt-bot]

@acardace: once the present PR merges, I will cherry-pick it on top of release-1.2 in a new PR and assign it to you.

In response to this:

/cherrypick release-1.2

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[kubevirt-bot]

@orelmisan: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-kubevirt-e2e-k8s-1.30-sig-network	000c9c3	link	unknown	/test pull-kubevirt-e2e-k8s-1.30-sig-network

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.

[fossedihelm]

/retest-required

[kubevirt-bot]

@acardace: new pull request created: #11985

In response to this:

/cherrypick release-1.2

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.