Bug 1974096

Summary:	libvirt.libvirtError: unsupported configuration: IOThreads only available for virtio pci and virtio ccw disk
Product:	Red Hat Enterprise Linux Advanced Virtualization	Reporter:	Igor Raits <igor.raits>
Component:	libvirt	Assignee:	Peter Krempa <pkrempa>
Status:	CLOSED ERRATA	QA Contact:	Han Han <hhan>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	8.5	CC:	bstinson, dyuan, jdenemar, jwboyer, lmen, pkrempa, smitterl, virt-maint, virt-qe-z
Target Milestone:	rc	Keywords:	Regression, Triaged
Target Release:	8.5	Flags:	pm-rhel: mirror+
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	libvirt-7.5.0-1.el8	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-11-16 07:54:24 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:	7.5.0
Embargoed:
Bug Depends On:	1970277
Bug Blocks:

Description Igor Raits 2021-06-20 14:07:45 UTC

Description of problem:
When trying to attach external volume (EBS, via iSCSI) to a VM that has IOThreads configured, I get following error.

Version-Release number of selected component (if applicable):

libvirt-7.4.0-1.el8s.x86_64
qemu-kvm-6.0.0-19.el8s.x86_64

How reproducible:

Always.

Steps to Reproduce:

Sadly I don't have some easy reproduction scenario.

Actual results:
libvirt.libvirtError: unsupported configuration: IOThreads only available for virtio pci and virtio ccw disk

Expected results:
No error.

Additional info:

I was able to find that this used to be an issue long time ago (https://bugzilla.redhat.com/show_bug.cgi?id=1430275) but it was fixed then, so probably it is regression again.

This actually happens with packages of CentOS Virtualization SIG (which is kinda maintained by Red Hat) and I could not find better place where to report this bug.

Comment 1 Igor Raits 2021-06-20 14:16:29 UTC

FTR previously libvirt was accepting this action and XML it generated was:

    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native' iothread='2'/>
      <source dev='/dev/dm-58' index='4'/>
      <backingStore/>
      <target dev='vdc' bus='virtio'/>
      <serial>05fcc448-4775-4692-9c22-f931d3356ca1</serial>
      <alias name='virtio-disk2'/>
      <address type='pci' domain='0x0000' bus='0x08' slot='0x00' function='0x0'/>
    </disk>

Comment 2 Igor Raits 2021-06-20 14:27:15 UTC

This has been introduced by a following commit (reverting fixes the problem):

commit 3df66f27a606c5c0f27958edf7bfaaf7dcc71264
Author: Peter Krempa <pkrempa>
Date:   Fri Apr 30 16:19:15 2021 +0200

    qemu: Move iothread and s390 address validation for disk devices into the validator
    
    The "machine-loadparm-multiple-disks-nets-s390" case now requires the
    QEMU_CAPS_CCW feature to pass validation.
    
    Signed-off-by: Peter Krempa <pkrempa>
    Reviewed-by: Ján Tomko <jtomko>
    Reviewed-by: Pavel Hrdina <phrdina>

Comment 3 Peter Krempa 2021-06-21 07:12:42 UTC

Fixed upstream:

commit c29bb0fbb623af7994925bccad04060c5e27b64b
Author: Peter Krempa <pkrempa>
Date:   Thu Jun 10 16:43:36 2021 +0200

    qemu: validate: Don't check bus type in qemuValidateDomainDeviceDefDiskIOThreads
    
    IOThreads are supported with all 3 currently supported buses which can
    have virtio devices (PCI, CCW, MMIO) , so there's no need for this check.
    
    Additionally this check was buggy in the current location as on e.g.
    hotplug cases the address may not yet be assigned for the disk and thus
    a bogus error would be printed.
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1970277
    Signed-off-by: Peter Krempa <pkrempa>
    Reviewed-by: Ján Tomko <jtomko>

v7.4.0-161-gc29bb0fbb6

Comment 6 Han Han 2021-07-15 05:56:38 UTC

Fixed on libvirt-7.5.0-1.module+el8.5.0+11664+59f87560.x86_64
Test case: rhel.cpu.iothread.negative_test.disk_attach.delete_without_detach

Comment 8 errata-xmlrpc 2021-11-16 07:54:24 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 (virt:av bug fix and enhancement update), 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-2021:4684