Bug 1982224

Summary:	[RHEL9]qemu segfault after the 2rd postcopy live migration with vhost-user
Product:	Red Hat Enterprise Linux 9	Reporter:	Pei Zhang <pezhang>
Component:	qemu-kvm	Assignee:	Juan Quintela <quintela>
qemu-kvm sub component:	Live Migration	QA Contact:	Pei Zhang <pezhang>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	high
Priority:	high	CC:	chayang, dgilbert, jinzhao, juzhang, maxime.coquelin, mrezanin, quintela, virt-maint
Version:	9.0
Target Milestone:	beta
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	qemu-kvm-6.2.0-1.el9	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:	1981782	Environment:
Last Closed:	2022-05-17 12:23:27 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:
Bug Depends On:	1981782, 2021976, 2021981, 2024981, 2025609
Bug Blocks:

Comment 1 Pei Zhang 2021-07-14 13:16:34 UTC

Versions:
5.13.0-1.rt3.1.el9.x86_64
qemu-kvm-6.0.0-8.el9.x86_64
libvirt-7.4.0-1.el9.x86_64
openvswitch2.15-2.15.0-16.el9fdp.x86_64

Note:
Currently postcopy hit existed issue: Bug 1945420 - [RHEL9] Setup vm.unprivileged_userfaultfd for postcopy

The workaround is: execute below cmd on both src and des host before doing postcopy live migration.

# echo 1 >/proc/sys/vm/unprivileged_userfaultfd

Comment 2 John Ferlan 2021-07-22 18:45:50 UTC

Meirav - keeping this and the cloned from bug together.

Comment 3 Juan Quintela 2021-11-10 10:19:45 UTC

Hi Pei

This brew should fix the issue:

https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=41123115

Patch exist upstream, and merge request has been sent.

Could you try it?

Thanks, Juan.

Comment 4 Pei Zhang 2021-11-11 06:19:50 UTC

(In reply to Juan Quintela from comment #3)
> Hi Pei
> 
> This brew should fix the issue:
> 
> https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=41123115
> 
> Patch exist upstream, and merge request has been sent.
> 
> Could you try it?

Juan, thank you providing this build. 

This bug cannot be reproduced this build, post copy live migration works well and no any error any more.

Versions:
qemu-kvm-6.1.0-6.el9.quintela202111091652.x86_64

Tested:
Testcase: live_migration_nonrt_server_2Q_1G_iommu_ovs_postcopy
PASS

Testcase: live_migration_nonrt_server_1Q_1G_iommu_ovs_postcopy
PASS

Testcase: live_migration_nonrt_server_4Q_1G_iommu_ovs_postcopy
PASS

Thanks.

Best regards,

Pei



> 
> Thanks, Juan.

Comment 5 Pei Zhang 2021-12-17 04:11:23 UTC

Verification:

Versions:
qemu-kvm-6.2.0-1.el9.x86_64
libvirt-7.10.0-1.el9.x86_64
5.14.0-31.el9.x86_64
openvswitch2.15-2.15.0-33.el9fdp.x86_64
tuned-2.16.0-4.el9.noarch

vhost-user 1Q/2Q/4Q post copy live migration work well, no qemu crash and no any error any more.  


Testcase: live_migration_nonrt_server_2Q_1G_iommu_ovs_postcopy
PASS

Testcase: live_migration_nonrt_server_1Q_1G_iommu_ovs_postcopy
PASS

Testcase: live_migration_nonrt_server_4Q_1G_iommu_ovs_postcopy
PASS


So this bug has been fixed very well. Will move to Verified once ON_QA.

Comment 6 Yanan Fu 2021-12-20 12:44:35 UTC

QE bot(pre verify): Set 'Verified:Tested,SanityOnly' as gating/tier1 test pass.

Comment 11 errata-xmlrpc 2022-05-17 12:23:27 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (new packages: qemu-kvm), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2022:2307