Created attachment 1226382 [details]
logs

Description of problem:
Some work was done in introducing support of q35 machine type - https://gerrit.ovirt.org/#/c/57775/4.
Part of this change includes adjustment of changeCD cmd to support an extended changeCD cmd in VDSM.
It seems something is wrong as I tried to changeCD with a vm with q35 machine type and got the following error msg:

"Error while executing action Change CD: Failed to perform "Change CD" operation, CD might be still in use by the VM.
Please try to manually detach the CD from withing the VM:
1. Log in to the VM
2 For Linux VMs, un-mount the CD using umount command;
For Windows VMs, right click on the CD drive and click 'Eject';"

No interesting information in engine.log or vdsm.log but I will attach it anyway.

When trying the same flow after stopping the vm and changing the machine type back to default (i440fx) , changeCD worked as expected.

Version-Release number of selected component (if applicable):
ovirt-engine-4.1.0-0.0.master.20161127231313.git9bb30a5.el7.centos

How reproducible:
always


Steps to Reproduce:
1. Create a vm with rhel7.2 os e.g. Select CDROM as secondary boot device.
2. After vm starts try to changeCD and choose some iso from your iso_domain.

Actual results:
Get the error mentioned above.

Expected results:
CD is changed as expcted.

Additional info:
vm domain xml: