Description:

Unable to start virtual machine with libvirt 1.2.1, libvirtd segfaults.
Previously worked with libvirt 1.2.0 (and downgrading fixes the problem).

Additional info:
* libvirt 1.2.1-1
* Log from journald:

Jan 17 12:50:10 kvmhost0 systemd[1]: Stopping Virtualization daemon...
Jan 17 12:50:10 kvmhost0 systemd[1]: Starting Virtualization daemon...
Jan 17 12:50:10 kvmhost0 systemd[1]: Started Virtualization daemon.
Jan 17 12:50:10 kvmhost0 libvirtd[1196]: libvirt version: 1.2.1
Jan 17 12:50:10 kvmhost0 libvirtd[1196]: Cannot check dnsmasq binary /sbin/dnsmasq: No such file or directory
Jan 17 12:50:10 kvmhost0 libvirtd[1196]: Could not find 'ebtables' executable
Jan 17 12:50:10 kvmhost0 libvirtd[1196]: Cannot find 'pm-is-supported' in path: No such file or directory
Jan 17 12:50:10 kvmhost0 libvirtd[1196]: Failed to get host power management capabilities
Jan 17 12:50:13 kvmhost0 libvirtd[1196]: Cannot find 'pm-is-supported' in path: No such file or directory
Jan 17 12:50:13 kvmhost0 libvirtd[1196]: Failed to get host power management capabilities
Jan 17 12:50:13 kvmhost0 libvirtd[1196]: Cannot find 'pm-is-supported' in path: No such file or directory
Jan 17 12:50:13 kvmhost0 libvirtd[1196]: Failed to get host power management capabilities
Jan 17 12:50:13 kvmhost0 avahi-daemon[142]: Joining mDNS multicast group on interface virbr0.IPv4 with address 192.168.122.1.
Jan 17 12:50:13 kvmhost0 avahi-daemon[142]: New relevant interface virbr0.IPv4 for mDNS.
Jan 17 12:50:13 kvmhost0 avahi-daemon[142]: Registering new address record for 192.168.122.1 on virbr0.IPv4.
Jan 17 12:50:13 kvmhost0 avahi-daemon[142]: Interface virbr0.IPv4 no longer relevant for mDNS.
Jan 17 12:50:13 kvmhost0 avahi-daemon[142]: Leaving mDNS multicast group on interface virbr0.IPv4 with address 192.168.122.1.
Jan 17 12:50:13 kvmhost0 avahi-daemon[142]: Withdrawing address record for 192.168.122.1 on virbr0.
Jan 17 12:50:13 kvmhost0 kernel: IPv6: ADDRCONF(NETDEV_UP): virbr0: link is not ready
Jan 17 12:50:13 kvmhost0 libvirtd[1196]: Cannot check dnsmasq binary /sbin/dnsmasq: No such file or directory
Jan 17 12:50:13 kvmhost0 avahi-daemon[142]: Withdrawing workstation service for virbr0.
Jan 17 12:50:31 kvmhost0 libvirtd[1196]: Caught Segmentation violation dumping internal log buffer:
Jan 17 12:50:31 kvmhost0 libvirtd[1196]: ====== start of log =====
Jan 17 12:50:31 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b231d4
Jan 17 12:50:31 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleEndMap:881 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleStartMap:853 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b231e1
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b231e9
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b231f1
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b231f9
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b23216
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b2321e
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleEndMap:881 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleStartMap:853 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b2322a
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b23232
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b2323a
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b23242
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b2325b
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b23263
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleEndMap:881 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleStartMap:853 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b23270
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b23278
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b23281
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b23289
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b232ae
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b232b6
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleEndMap:881 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleStartMap:853 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b232c2
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b232ca
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b232d2
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b232da
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleMapKey:835 : parser=0x7fffa90e46b0 key=0x7f9491b23303
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleString:815 : parser=0x7fffa90e46b0 str=0x7f9491b2330b
Jan 17 12:50:32 kvmhost0 libvirtd[1196]: 2014-01-17 02:20:31.947+0000: 1196: debug : virJSONParserHandleEndMap:881 : parser=0x7fffa90e46b0
Jan 17 12:50:32 kvmhost0 systemd[1]: libvirtd.service: main process exited, code=dumped, status=11/SEGV
Jan 17 12:50:32 kvmhost0 systemd[1]: Unit libvirtd.service entered failed state.

Steps to reproduce:

# virsh start win7
error: Failed to start domain win7
error: End of file while reading data: Input/output error
error: Failed to reconnect to the hypervisor

# virsh dumpxml win7
<domain type='kvm'>
<name>win7</name>
<uuid>fb683081-01c0-ee11-3e6f-580c62216b59</uuid>
<memory unit='KiB'>2097152</memory>
<currentMemory unit='KiB'>2097152</currentMemory>
<vcpu placement='static'>2</vcpu>
<os>
<type arch='x86_64' machine='pc-i440fx-1.7'>hvm</type>
<boot dev='cdrom'/>
<boot dev='hd'/>
</os>
<features>
<acpi/>
<apic/>
<pae/>
</features>
<clock offset='localtime'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<devices>
<emulator>/usr/bin/qemu-system-x86_64</emulator>
<disk type='volume' device='disk'>
<driver name='qemu' type='raw' cache='none'/>
<source pool='vmspace' volume='win7.img'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</disk>
<disk type='volume' device='cdrom'>
<driver name='qemu' type='raw'/>
<source startupPolicy='optional'/>
<target dev='hdc' bus='ide'/>
<readonly/>
<address type='drive' controller='0' bus='1' target='0' unit='0'/>
</disk>
<controller type='ide' index='0'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
</controller>
<controller type='usb' index='0'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
</controller>
<controller type='pci' index='0' model='pci-root'/>
<interface type='bridge'>
<mac address='52:54:00:cd:7a:f1'/>
<source bridge='br0'/>
<model type='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
<serial type='pty'>
<target port='0'/>
</serial>
<console type='pty'>
<target type='serial' port='0'/>
</console>
<input type='tablet' bus='usb'/>
<input type='mouse' bus='ps2'/>
<graphics type='vnc' port='-1' autoport='yes' listen='127.0.0.1'>
<listen type='address' address='127.0.0.1'/>
</graphics>
<video>
<model type='cirrus' vram='9216' heads='1'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
</video>
<memballoon model='virtio'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
</memballoon>
</devices>
<seclabel type='none'/>
</domain>