Bug 1720612

Summary: Video element of type "none" has its alias removed
Product: Red Hat Enterprise Linux Advanced Virtualization Reporter: Tomasz Barański <tbaransk>
Component: libvirtAssignee: Jonathon Jongsma <jjongsma>
Status: CLOSED ERRATA QA Contact: yafu <yafu>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 8.0CC: chhu, dyuan, jdenemar, jsuchane, knoel, lmen, xuzhang, yafu, yalzhang
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: libvirt-5.9.0-1.el8 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-05-05 09:46:33 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:
Embargoed:

Description Tomasz Barański 2019-06-14 11:14:06 UTC
Description of problem:

When using vGPU as a display device, an video of type "none" needs to be included in the XML to prevent an insertion of a default video device. However, when queried, libvirt reports the "none" video device but replaces device's alias with a different value.

Version-Release number of selected component (if applicable):
libvirt-4.5.0-10.el7_6.9.x86_64
qemu-kvm-rhev-2.12.0-18.el7_6.5.x86_64


How reproducible:
100%


Steps to Reproduce:
1. Define a VM with the following elements:

    <video>
      <model type="none"/>
      <alias name="ua-1035e984-8238-46e1-bf56-b546246e1a14"/>
    </video>
    <hostdev mode="subsystem" type="mdev" model="vfio-pci" display="on">
      <source>
        <address uuid="4c38d85c-8ad8-44b8-a98f-b48448ff8e18"/>
      </source>
    </hostdev>

and a graphics element.

2. Start a VM

3. Query libvirt for VM's XML definition

Actual results:

The following video element is returned:

    <video>
      <model type='none'/>
      <alias name='video0'/>
    </video>


Expected results:
Video should match the one used when defining the VM.

Comment 2 Jonathon Jongsma 2019-09-04 21:10:29 UTC
Out of curiosity, what's the use case for assigning a user alias to a video of type 'none'? This is really an indication that there are no devices rather than an actual device with properties.

Comment 3 Tomasz Barański 2019-09-05 13:42:18 UTC
oVirt uses it to correlate between the devices it keeps track of and the devices libvirt reports. It uses aliases to do it.

Comment 4 Jonathon Jongsma 2019-09-09 14:26:30 UTC
fix pushed upstream:

commit 9f90a4bfb4f93b9922680a11eaff9baa9046b4f8
Author: Jonathon Jongsma <jjongsma>

    qemu: maintain user alias for video type 'none'

Comment 6 yafu 2020-02-04 02:47:48 UTC
Verified with libvirt-6.0.0-2.module+el8.2.0+5513+34927b6c.x86_64.

Test steps:
1.Edit a guest with 'none' type video and alias name:
#virsh edit vm1
 <video>
      <model type='none'/>
      <alias name='ua-1035e984-8238-46e1-bf56-b546246e1a35'/>
 </video>

2.Check the alias name of 'none' type video:
#virsh dumpxml xm1 | grep -A5 video
<video>
  <model type='none'/>
  <alias name='ua-1035e984-8238-46e1-bf56-b546246e1a35'/>
</video>

3.Start guest:
#virsh start vm1

4.Check the alias name of 'none' type video:
#virsh dumpxml xm1 | grep -A5 video
<video>
  <model type='none'/>
  <alias name='ua-1035e984-8238-46e1-bf56-b546246e1a35'/>
</video>

Comment 8 errata-xmlrpc 2020-05-05 09:46:33 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, 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-2020:2017