Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Bug 2214502

Summary: [RHEL8][CPU-hotplug][s390x] after hotplug CPU by qmp command /proc/cpuinfo still shows the wrong info
Product: Red Hat Enterprise Linux 8 Reporter: bfu <bfu>
Component: systemdAssignee: systemd-maint
Status: CLOSED NOTABUG QA Contact: Frantisek Sumsal <fsumsal>
Severity: high Docs Contact:
Priority: high    
Version: 8.9CC: clegoate, cohuck, coli, dgilbert, dhorak, hannsj_uhl, jinzhao, juzhang, knoel, lijin, pbonzini, ribarry, smitterl, stefanha, thuth, vgoyal, virt-maint, virt-qe-z, yiwei
Target Milestone: rcKeywords: Regression
Target Release: ---Flags: pm-rhel: mirror+
Hardware: s390x   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2023-06-13 08:39:40 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description bfu 2023-06-13 07:38:40 UTC
Description of problem:
/proc/cpuinfo cannot shows correct CPU number after hotplug vCPU by qmp command

Version-Release number of selected component (if applicable):
kernel: 4.18.0-496.el8.s390x
qemu-kvm: qemu-kvm-6.2.0-35.module+el8.9.0+19024+8193e2ac.s390x

How reproducible:
100%

1. boot up guest with
"-smp 5,maxcpus=6,cores=3,threads=1,sockets=2  \"
2. hot-plug 1 vCPU by command in qmp:
"{"execute": "device_add", "arguments": {"id": "vcpu1", "driver": "host-s390x-cpu", "core-id": 5}, "id": "F13T8uRq"}"
3. search the CPU info in /proc/cpuinfo
"grep -c "^processor\b" /proc/cpuinfo"

Actual results:
[root@localhost ~]# grep -c "^processor\b" /proc/cpuinfo
5


Expected results:
[root@localhost ~]# grep -c "^processor\b" /proc/cpuinfo
6

Additional info:
Didn't hit this issue with:

kernel version: 4.18.0-492.el8.s390x
qemu version: qemu-kvm-6.2.0-34.module+el8.9.0+18868+5565e56d.s390x


http://10.0.136.47/7944438/test-results/101-Host_RHEL.m8.u9.v0.product_rhel.nographic.qcow2.virtio_scsi.up.virtio_net.Guest.RHEL.9.3.0.s390x.io-github-autotest-qemu.cpu_device_hotpluggable.hotplug.single_vcpu.with_reboot.shell_reboot.s390-virtio/debug.log

Comment 2 bfu 2023-06-13 08:39:40 UTC
sorry, wrong bug reported