[Ubuntu 24.04] hotplug of 68 or more cpus is making the guest shutoff!

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== Comment: #0 - Kowshik Jois B S <email address hidden> - 2024-05-21 01:41:34 ==
I have created a guest with maxcpus as 128 and given current value as 4. When I try to hotplug 68 or more cpus, the guest is entering the shut off state.

This behavior was observed initially on the guest with 2G Memory. Then I increased it to 4G but exactly the same behavior is seen again!

---uname output---
Linux ubuntulp3host 6.8.0-31-generic #31-Ubuntu SMP Sat Apr 20 00:05:55 UTC 2024 ppc64le ppc64le ppc64le GNU/Linux

Machine Type = P10 Denali

Contact Information = <email address hidden>

---Steps to Reproduce---
1. virsh define hotplug.xml
2. virsh start Ubuntu --console
3. On the other L1 terminal,
    virsh setvcpus Ubuntu 68

Expected Output:
68 cpus should be hotplugged.

Actual output:
1. guest session terminated.

2. root@ubuntulp3host:~# virsh setvcpus Ubuntu 68
error: Unable to read from monitor: Connection reset by peer

3. host dmesg:
[257209.825657] audit: type=1400 audit(1716219915.959:190): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="libvirt-6c80667b-c7e4-42d0-ad6f-13ba24e6b059//passt" pid=11594 comm="apparmor_parser"
[257211.741363] virbr0: port 1(vnet0) entered learning state
[257213.761361] virbr0: port 1(vnet0) entered forwarding state
[257213.761369] virbr0: topology change detected, propagating
[257251.720268] KVM: Create Guest vcpu hcall failed, rc=-44
[257251.782307] virbr0: port 1(vnet0) entered disabled state
[257251.782609] vnet0 (unregistering): left allmulticast mode
[257251.782612] vnet0 (unregistering): left promiscuous mode
[257251.782615] virbr0: port 1(vnet0) entered disabled state
[257251.996802] audit: type=1400 audit(1716219958.127:191): apparmor="STATUS" operation="profile_remove" profile="unconfined" name="libvirt-6c80667b-c7e4-42d0-ad6f-13ba24e6b059" pid=11720 comm="apparmor_parser"

please include this patch

https://<email address hidden>/T/#m9081c12e6fb42f34ebff78d91beee9dbfc5990fd

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Default Comment by Bridge

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------- Comment From <email address hidden> 2024-06-18 02:54 EDT-------
distro, any update on this bug?

[Frank Heimes (fheimes)]

Hello, as far as I can see (and I just double checked at github.com/qemu) the patch set
PATCH v2 - "target/ppc: vcpu hotplug failure handling fixes" (4 parts)
is still not upstream accepted - not in 9.0.1 (latest) nor in master (commit list).
(But please, correct me if I'm wrong, in case the commit names have changes or other reasons that may have prevented me from finding them upstream.)

Please note that we need the patches to be upstream accepted before we can pick (and 'SRU') them.
(A ping here in case they got accepted would be helpful too.)