libvirt + libxl (Xen) PV console broken

[GeorgeDunlap]

Using virt-installer with libvirt/libxl in 14.04 I saw this:

http://pastebin.com/6pbS6Db7

# virt-install --connect=xen:/// --name u14.04 --ram 1024 --disk U1L1.img,size=2 --location http://ftp.ubuntu.com/ubuntu/dists/raring/main/installer-amd64/

Starting install...
Retrieving file MANIFEST...
                        | 2.1 kB 00:00 ...
Retrieving file MANIFEST...
                        | 2.1 kB 00:00 ...
Retrieving file vmlinuz...
                        | 10 MB 00:00 ...
Retrieving file initrd.gz...
                        | 36 MB 02:34 ...
Creating storage file U1L1.img
                        | 2.0 GB 00:00
Creating domain...
                        | 0 B 00:03
Connected to domain u14.04
Escape character is ^]
error: internal error: cannot find character device <null>

It turns out this was fixed in libvirt 1.2.4; c/s
657cb1e44d90bab451256616f9d98fb4439a080c

(You can browse the commit here:
http://libvirt.org/git/?p=libvirt.git;a=commit;h=657cb1e44d90bab451256616f9d98fb4439a080c
)

Would it be possible to backport that change into 14.04, so
virt-install can be used to install PV guests?

[Stefan Bader (smb)]

The libvirt version in utopic (1.2.5) already contains that change.

[Stefan Bader (smb)]

SRU Justification (for Trusty)

Impact: Currently it is not possible to use "console <guest>" from virsh for a PV guest, even when a console is defined. With the patch applied this works.

Fix: Single patch cherry-picked from upstream solves the issue.

Testcase: Define a PV guest in libvirt with the following console definition:

<console type='pty'>
  <target type='xen'/>
</console>

Start the PV guest from virsh and try to connect to the console (console <domid|domname>). Without the patch this results in an error message. With the patch applied the console output shows up.

[Chris J Arges (arges)]

Hello GeorgeDunlap, or anyone else affected,

Accepted libvirt into trusty-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/libvirt/1.2.2-0ubuntu13.1.2 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!

[Stefan Bader (smb)]

Hey George, would have been great if you had had time for verification. ;) Anyway, tried the proposed package with a PV guest through libxl/libvirt and can connect to the console via the console command.

[Launchpad Janitor (janitor)]

This bug was fixed in the package libvirt - 1.2.2-0ubuntu13.1.2

---------------
libvirt (1.2.2-0ubuntu13.1.2) trusty; urgency=low

  * debian/apparmor/usr.sbin.libvirtd: allow libvirtd to run
    libxl-save-helper (required for save restore through libxl).
    (LP: #1334195)
  * debian/apparmor/usr.sbin.libvirtd: allow pygrub to be run
    (LP: #1326003)
  * debian/patches/libxl-Support-PV-consoles.patch
    Enable console support for PV guests (LP: #1334738)
 -- Stefan Bader <email address hidden> Thu, 26 Jun 2014 16:03:42 +0200

[Chris J Arges (arges)]

The verification of the Stable Release Update for libvirt 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 regressions.