attach-device of usb falsely declares device in use by other domain

[Bill Mills]

=================================
SRU Justification
1. Impact: cannot attach host usb device to domain 2 after attaching it to domain 1 and shutting down domain 1.
2. Development fix: Reattach usb device to host when domain shuts down
3. Stable fix: same as development fix backport of upstream patch.
4. test case:
 To test inside a precise kvm guest,
 1. create a nested libvirt domain as per https://wiki.ubuntu.com/SergeHallyn_libvirtnest
 2. Create usb.xml file containing:
    <hostdev mode='subsystem' type='usb' managed='yes'>
      <source>
        <vendor id='0x1d6b'/>
        <product id='0x0001'/>
      </source>
    </hostdev>
        3. start cdboot, and attach the device to it
    virsh start cdboot
    virsh attach-device cdboot usb.xml
 4. stop cdboot, restart it, and try to attach the device again
    virsh destroy cdboot
    virsh start cdboot
    virsh attach-device cdboot usb.xml
 Without this fix, the second attach-device will fail.
5. Regression potential:
   This adds new code to the domain shutdown and libvirt start sequences. However they
   only affect the list of usb devices, so any regressions should be caught at usb
   device add/remove and libvirtd start/stop.

=================================

Running Ubuntu 12.04 x86_64
libvirt0 and libvirt-bin 0.9.8-2ubuntu17.8 causes a regression.
I am using QEMU/KVM virtual machines.

To reproduce:
   use virsh to create/start a vm
   use virsh to attach-device a host usb device
   use virsh to stop/destroy the vm
   use virsh to create vm again
   use virsh to attach the usb device again

I get:
virsh attach-device vm1 /var/lib/libvirt/hotplug/usb-serial.xml
error: Failed to attach device from /var/lib/libvirt/hotplug/usb-serial.xml
error: Requested operation is not valid: USB device 002:005 is in use by domain ..

Note the ".." characters. That is literal. It is printing garbage characters.
The failure is not 100% of the time but is pretty high (50% ?)

usb-serial.xml:
    <hostdev mode='subsystem' type='usb' managed='yes'>
      <source>
        <vendor id='0x067b'/>
        <product id='0x2303'/>
      </source>
    </hostdev>

backing up libvirt0 and libvirt-bin to 0.9.8-2ubuntu17.7 makes this problem go away.

While looking at this I found a Fedora bug that looks similar. The upstream patches they identified may be of interest.
https://bugzilla.redhat.com/show_bug.cgi?id=814866

[Serge Hallyn (serge-hallyn)]

The attached debdiff fixed the problem for me.

Unfortunately we need to wait for 0.9.8-2ubuntu17.10 to be promoted from precise-proposed to precise-updates (for bug 1113821) before we can push this.

The debdiff will also need to be refreshed against 0.9.8-2ubuntu17.10.

[Dave Walker (davewalker)]

Hello Bill, or anyone else affected,

Accepted libvirt into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/libvirt/0.9.8-2ubuntu17.14 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Serge Hallyn (serge-hallyn)]

There was a failure to build due to a failed testcase. Sorry, investigating.

[Stéphane Graber (stgraber)]

Hello Bill, or anyone else affected,

Accepted libvirt into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/libvirt/0.9.8-2ubuntu17.15 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Serge Hallyn (serge-hallyn)]

Fix confirmed in precise-proposed.

[Launchpad Janitor (janitor)]

This bug was fixed in the package libvirt - 0.9.8-2ubuntu17.15

---------------
libvirt (0.9.8-2ubuntu17.15) precise-proposed; urgency=low

  * update fix-for-parallel-port-passthrough-for-qemu: the xml for the new
    testcase was too modern and caused the test to fail by including new
    keywords.

libvirt (0.9.8-2ubuntu17.14) precise-proposed; urgency=low

  * qemu-delete-usb-devices-on-stop and
    qemu-build-activeusbhostdevs-on-reconnect: ensure that we can re-use
    a usb device after another domain using the device has shut
    down. (LP: #1190387) Backported from upstream git.
  * cherrypick fix-for-parallel-port-passthrough-for-qemu from upstream
    (LP: #1203620)
 -- Serge Hallyn <email address hidden> Mon, 14 Oct 2013 10:32:22 -0500

[Colin Watson (cjwatson)]

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.