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Bug 1554928

Summary: 'update-device' with alias in disk did not work actually and 'cold-plug' device with alias to running VM will fail in dumpxml file [rhel-7.5.z]
Product: Red Hat Enterprise Linux 7 Reporter: Oneata Mircea Teodor <toneata>
Component: libvirtAssignee: Michal Privoznik <mprivozn>
Status: CLOSED ERRATA QA Contact: jiyan <jiyan>
Severity: urgent Docs Contact:
Priority: urgent    
Version: 7.5CC: dyuan, hhan, jdenemar, jherrman, jiyan, jsuchane, lmen, meili, mprivozn, mtessun, rbalakri, salmy, xuzhang, yalzhang, yisun
Target Milestone: rcKeywords: Upstream, ZStream
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: libvirt-3.9.0-14.el7_5.1 Doc Type: Bug Fix
Doc Text:
Previously, the libvirt service used the incorrect XML configuration when checking for a duplicate user alias. As a consequence, hot-plugging a device with a unique alias to a guest virtual machine in some cases failed with a "non unique alias" error message. With this update, libvirt uses the correct XML files for verifying the device alias, which prevents the problem from occurring.
 Story Points: ---
Clone Of: 1543775 Environment:
Last Closed: 2018-04-10 19:13:42 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: 1543775    
Bug Blocks:    

Description Oneata Mircea Teodor 2018-03-13 15:15:47 UTC 
This bug has been copied from bug #1543775 and has been proposed to be backported to 7.5 z-stream (EUS).
Comment 3 Michal Privoznik 2018-03-14 07:26:53 UTC 
To POST:

http://post-office.corp.redhat.com/archives/rhvirt-patches/2018-March/msg00318.html

Scratch build to test can be found here:

https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=15543618
Comment 5 jiyan 2018-03-16 03:43:14 UTC 
Hi, Michal, I still can reproduce this issue: 'update-device' with alias in disk did not work actually. Could you please help to check it?

Version:
kernel-3.10.0-860.el7.x86_64
qemu-kvm-rhev-2.10.0-21.el7_5.1.x86_64
libvirt-3.9.0-14.virtcov.el7_5.1.x86_64

Step:
# virsh domstate test1
shut off

# virsh start test1
Domain test1 started

# virsh dumpxml test1 |grep "<disk" -A7
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/RHEL-7.5-x86_64-latest.qcow2'/>
      <backingStore/>
      <target dev='hda' bus='usb'/>
      <alias name='usb-disk0'/>
      <address type='usb' bus='0' port='1.3'/>
    </disk>

# cat diskchangealias.xml 
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/RHEL-7.5-x86_64-latest.qcow2'/>
      <backingStore/>
      <target dev='hda' bus='usb'/>
      <alias name='ua-disk2'/>
    </disk>

# virsh update-device test1 diskchangealias.xml 
Device updated successfully

# virsh dumpxml test1 |grep "<disk" -A7
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/RHEL-7.5-x86_64-latest.qcow2'/>
      <backingStore/>
      <target dev='hda' bus='usb'/>
      <alias name='usb-disk0'/>   ***Not changed here***
      <address type='usb' bus='0' port='1.3'/>
    </disk>
Comment 6 Michal Privoznik 2018-03-16 11:52:13 UTC 
(In reply to jiyan from comment #5)
> Hi, Michal, I still can reproduce this issue: 'update-device' with alias in
> disk did not work actually. Could you please help to check it?
> 
> Version:
> kernel-3.10.0-860.el7.x86_64
> qemu-kvm-rhev-2.10.0-21.el7_5.1.x86_64
> libvirt-3.9.0-14.virtcov.el7_5.1.x86_64
> 
> Step:
> # virsh domstate test1
> shut off
> 
> # virsh start test1
> Domain test1 started
> 
> # virsh dumpxml test1 |grep "<disk" -A7
>     <disk type='file' device='disk'>
>       <driver name='qemu' type='qcow2'/>
>       <source file='/var/lib/libvirt/images/RHEL-7.5-x86_64-latest.qcow2'/>
>       <backingStore/>
>       <target dev='hda' bus='usb'/>
>       <alias name='usb-disk0'/>
>       <address type='usb' bus='0' port='1.3'/>
>     </disk>
> 
> # cat diskchangealias.xml 
>     <disk type='file' device='disk'>
>       <driver name='qemu' type='qcow2'/>
>       <source file='/var/lib/libvirt/images/RHEL-7.5-x86_64-latest.qcow2'/>
>       <backingStore/>
>       <target dev='hda' bus='usb'/>
>       <alias name='ua-disk2'/>
>     </disk>
> 
> # virsh update-device test1 diskchangealias.xml 
> Device updated successfully
> 
> # virsh dumpxml test1 |grep "<disk" -A7
>     <disk type='file' device='disk'>
>       <driver name='qemu' type='qcow2'/>
>       <source file='/var/lib/libvirt/images/RHEL-7.5-x86_64-latest.qcow2'/>
>       <backingStore/>
>       <target dev='hda' bus='usb'/>
>       <alias name='usb-disk0'/>   ***Not changed here***
>       <address type='usb' bus='0' port='1.3'/>
>     </disk>

This is harmless. I'm gonna post a patch that forbids changing alias for live domains. However, this shouldn't matter for RHEL-7.5.z.
Comment 7 jiyan 2018-03-19 01:13:44 UTC 
Version:
qemu-kvm-rhev-2.10.0-21.el7_5.1.x86_64
kernel-3.10.0-861.el7.x86_64
libvirt-3.9.0-14.el7_5.1.x86_64

The following steps are trying to verify the Issue-2 in the bug description.

Scenario: Cold-plug interface to running VM twice, then hot-plug the interface twice, at last, hot-unplug and cold-unplug the interface.

Step1. Prepare a shutdown VM and a xml file as following
# virsh domstate test1
shut off

# virsh dumpxml test1 |grep "<interface" -A5
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

# cat interface.xml 
    <interface type='network'>
      <mac address='22:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <alias name='ua-interface'/>
    </interface>

Step2. Start VM and cold-plug the interface, check dumpxml file info
# virsh start test1
Domain test1 started

# virsh attach-device test1 interface.xml --config
Device attached successfully

# virsh dumpxml test1 |grep "<interface" -A7
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default' bridge='virbr0'/>
      <target dev='vnet0'/>
      <model type='rtl8139'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

# virsh dumpxml test1 --inactive|grep "<interface" -A6
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <interface type='network'>
      <mac address='22:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <alias name='ua-interface'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </interface>

Step3: Clod-plug the interface again, there should be some error info, the dumpxml file info shoule be same with Step-2
# virsh attach-device test1 interface.xml --config
error: Failed to attach device from interface.xml
error: XML error: non unique alias detected: ua-interface

# virsh dumpxml test1 |grep "<interface" -A7
Same with Step-2

# virsh dumpxml test1 --inactive|grep "<interface" -A6
Same with Step-2

Step4: Hot-plug the interface again and check the dumpxml file info
# virsh attach-device test1 interface.xml 
Device attached successfully

# virsh dumpxml test1 |grep "<interface" -A7
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default' bridge='virbr0'/>
      <target dev='vnet0'/>
      <model type='rtl8139'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <interface type='network'>
      <mac address='22:54:00:32:e6:35'/>
      <source network='default' bridge='virbr0'/>
      <target dev='vnet1'/>
      <model type='rtl8139'/>
      <alias name='ua-interface'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </interface>

# virsh dumpxml test1 --inactive|grep "<interface" -A6
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <interface type='network'>
      <mac address='22:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <alias name='ua-interface'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </interface>

Step5: Hot-plug the interface again, there should be some error info, the dumpxml file info shoule be same with Step-4
# virsh attach-device test1 interface.xml
error: Failed to attach device from interface.xml
error: XML error: non unique alias detected: ua-interface

# virsh dumpxml test1 |grep "<interface" -A7
Same with Step-4

# virsh dumpxml test1 --inactive|grep "<interface" -A6
Same with Step-4

Step6: Hot-unplug the interface and check the dumpxml file info
# virsh detach-device test1 interface.xml 
Device detached successfully

# virsh dumpxml test1 --inactive|grep "<interface" -A6
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <interface type='network'>
      <mac address='22:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <alias name='ua-interface'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </interface>

# virsh dumpxml test1|grep "<interface" -A7
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default' bridge='virbr0'/>
      <target dev='vnet0'/>
      <model type='rtl8139'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

Step7: Hot-unplug the interface again, there should be some error info, the dumpxml file info shoule be same with Step-6
# virsh detach-device test1 interface.xml 
error: Failed to detach device from interface.xml
error: operation failed: no device matching MAC address 22:54:00:32:e6:35 found

# virsh dumpxml test1 |grep "<interface" -A7
Same with Step-6

# virsh dumpxml test1 --inactive|grep "<interface" -A6
Same with Step-6

Step8: Cold-unplug the interface and check the dumpxml file info
# virsh detach-device test1 interface.xml --config
Device detached successfully

# virsh dumpxml test1|grep "<interface" -A7
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default' bridge='virbr0'/>
      <target dev='vnet0'/>
      <model type='rtl8139'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

# virsh dumpxml test1 --inactive|grep "<interface" -A5
    <interface type='network'>
      <mac address='52:54:00:32:e6:35'/>
      <source network='default'/>
      <model type='rtl8139'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

Step9: Cold-unplug the interface again, there should be some error info, the dumpxml file info shoule be same with Step-8
# virsh detach-device test1 interface.xml --config
error: Failed to detach device from interface.xml
error: operation failed: no device matching MAC address 22:54:00:32:e6:35 found

# virsh dumpxml test1 |grep "<interface" -A7
Same with Step-8

# virsh dumpxml test1 --inactive|grep "<interface" -A5
Same with Step-8

All the results are as expected, move this bug to 'verified'.
Comment 10 errata-xmlrpc 2018-04-10 19:13:42 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-2018:1056