Bug 1567858

Summary: [Regression] - Cannot start VM with <Empty> vNIC
Product: [oVirt] ovirt-engine Reporter: Michael Burman <mburman>
Component: BLL.VirtAssignee: Arik <ahadas>
Status: CLOSED CURRENTRELEASE QA Contact: Michael Burman <mburman>
Severity: high Docs Contact:
Priority: urgent    
Version: 4.2.2.6CC: bugs, danken, michal.skrivanek
Target Milestone: ovirt-4.2.3Keywords: Automation, Regression
Target Release: 4.2.3.2Flags: rule-engine: ovirt-4.2+
rule-engine: blocker+
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: ovirt-engine-4.2.3.2 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2018-05-10 06:29:12 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: Virt RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
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Description Michael Burman 2018-04-16 10:07:31 UTC 
Created attachment 1422395 [details]
logs

Description of problem:
[Regression] -  Cannot start VM with <Empty> vNIC.

The same BZ 1554222 that was successfully verified on 4.2.2.2-0.1.el7 and run in automation tests for a month, started failing again on latest 4.2.3 build.

xml - 
 <interface type="bridge">
      <model type="virtio"/>
      <link state="up"/>
      <source bridge=""/>
      <alias name="ua-a17b8639-477b-43fd-8621-ea4c1f80745b"/>
      <address bus="0x00" domain="0x0000" function="0x0" slot="0x03" type="pci"/>
      <boot order="2"/>
      <mac address="00:00:00:00:00:50"/>
      <bandwidth/>
    </interface>

2018-04-16 12:58:18,674+0300 ERROR (vm/f8abc451) [virt.vm] (vmId='f8abc451-ad7d-4916-ae0b-fca5cfa643bb') The vm start process failed (vm:943)
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/vdsm/virt/vm.py", line 872, in _startUnderlyingVm
    self._run()
  File "/usr/lib/python2.7/site-packages/vdsm/virt/vm.py", line 2872, in _run
    dom.createWithFlags(flags)
  File "/usr/lib/python2.7/site-packages/vdsm/common/libvirtconnection.py", line 130, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/vdsm/common/function.py", line 92, in wrapper
    return func(inst, *args, **kwargs)
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 1099, in createWithFlags
    if ret == -1: raise libvirtError ('virDomainCreateWithFlags() failed', dom=self)
libvirtError: Cannot get interface MTU on '': No such device
2018-04-16 12:58:18,674+0300 INFO  (vm/f8abc451) [virt.vm] (vmId='f8abc451-ad7d-4916-ae0b-fca5cfa643bb') Changed state to Down: Cannot get interface MTU on '': No such device (code=1) (vm:1683)

Version-Release number of selected component (if applicable):
rhvm-4.2.3-0.1.el7.noarch
vdsm-4.20.25-1.el7ev.x86_64
kernel-3.10.0-862.el7.x86_64
libvirt-client-3.9.0-14.el7_5.2.x86_64
libvirt-daemon-3.9.0-14.el7_5.2.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Try to run VM with <Empty> vNIC

Actual results:
libvirtError: Cannot get interface MTU on '': No such device

Expected results:
Should work
Comment 1 Michal Skrivanek 2018-04-17 05:15:43 UTC 
The engine should really send the dummy bridge instead. The approach in bug 1533762 for the same issue in hotplug was wrong
Comment 2 Michael Burman 2018-04-22 07:46:22 UTC 
Verified on - 4.2.3.2-0.1.el7
Comment 3 Sandro Bonazzola 2018-05-10 06:29:12 UTC 
This bugzilla is included in oVirt 4.2.3 release, published on May 4th 2018.

Since the problem described in this bug report should be
resolved in oVirt 4.2.3 release, it has been closed with a resolution of CURRENT RELEASE.

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