[Pkg-libvirt-maintainers] Bug#665329: libvirt-bin: Starting a kvm virtual machine with a serial/parallel chardevice attached to a pty fails with 'chardev: opening backend "pty" failed'

[Sebastian Schrader]

Package: libvirt-bin
Version: 0.8.3-5+squeeze2
Severity: important

Whenever a serial or parallel character device is attached to a kvm virtual
machine and presented to the host as pty, libvirt reports
  chardev: opening backend "pty" failed

Starting the virtual machine manually using the command-line libvirt used
according /var/log/libvirt/qemu/<domain>.log works fine. Using the backported
libvirt yields a more verbose error message:
  chardev: opening backend "pty" failed: Permission denied

Steps to reproduce:
Add the following elements
<serial type='pty'>
  <target port='0'/>
</serial>
<console type='pty'>
  <target type='serial' port='0'/>
</console>
to a libvirt qemu domain.

-- System Information:
Debian Release: 6.0.4
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-0.bpo.1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libvirt-bin depends on:
ii  adduser            3.112+nmu2            add and remove users and groups
ii  libavahi-client3   0.6.27-2+squeeze1     Avahi client library
ii  libavahi-common3   0.6.27-2+squeeze1     Avahi common library
ii  libblkid1          2.17.2-9              block device id library
ii  libc6              2.11.3-3              Embedded GNU C Library: Shared lib
ii  libcap-ng0         0.6.4-1               An alternate posix capabilities li
ii  libdevmapper1.02.1 2:1.02.48-5           The Linux Kernel Device Mapper use
ii  libgcrypt11        1.4.5-2               LGPL Crypto library - runtime libr
ii  libgnutls26        2.8.6-1+squeeze1      the GNU TLS library - runtime libr
ii  libnl1             1.1-6                 library for dealing with netlink s
ii  libparted0debian1  2.3-5                 The GNU Parted disk partitioning s
ii  libpciaccess0      0.12.0-1              Generic PCI access library for X
ii  libreadline6       6.1-3                 GNU readline and history libraries
ii  libsasl2-2         2.1.23.dfsg1-7        Cyrus SASL - authentication abstra
ii  libudev0           164-3                 libudev shared library
ii  libuuid1           2.17.2-9              Universally Unique ID library
ii  libvirt0           0.8.3-5+squeeze2      library for interfacing with diffe
ii  libxenstore3.0     4.0.1-4               Xenstore communications library fo
ii  libxml2            2.7.8.dfsg-2+squeeze3 GNOME XML library
ii  logrotate          3.7.8-6               Log rotation utility

Versions of packages libvirt-bin recommends:
ii  bridge-utils      1.4-5                  Utilities for configuring the Linu
pn  dnsmasq-base      <none>                 (no description available)
ii  ebtables          2.0.9.2-2              Ethernet bridge frame table admini
ii  gawk              1:3.1.7.dfsg-5         GNU awk, a pattern scanning and pr
ii  iptables          1.4.8-3                administration tools for packet fi
ii  libxml2-utils     2.7.8.dfsg-2+squeeze3  XML utilities
ii  netcat-openbsd    1.89-4                 TCP/IP swiss army knife
ii  qemu-kvm          0.12.5+dfsg-5+squeeze8 Full virtualization on x86 hardwar

Versions of packages libvirt-bin suggests:
pn  policykit-1                   <none>     (no description available)

-- Configuration Files:
/etc/libvirt/qemu.conf changed [not included]

-- no debconf information