Booting with the drive specified within the XML also gives a blank DVD in the VM, no luck there. It turns out I'm running libvirt 7.0, was there a large change between 7.0 and 7.1 in the way they handle mounting block devices?
After mounting at runtime, not at boot to the VM.
virsh # dumpxml Montreal
<domain type='kvm' id='3'>
<name>Montreal</name>
<uuid>0f79ba7f-27bf-16a0-5887-6cfa2b5569f1</uuid>
<memory>2097152</memory>
<currentMemory>2097152</currentMemory>
<vcpu>4</vcpu>
<os>
<type arch='x86_64' machine='pc-0.11'>hvm</type>
<boot dev='hd'/>
</os>
<features>
<acpi/>
<apic/>
<pae/>
</features>
<clock offset='utc'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<devices>
<emulator>/usr/bin/kvm</emulator>
<disk type='block' device='cdrom'>
<source dev='/dev/dvd'/>
<target dev='hdc' bus='ide'/>
<readonly/>
</disk>
<disk type='file' device='disk'>
<source file='/mnt/vmdrive/Montreal-ubuntu-media/montreal.vmdk'/>
<target dev='vda' bus='virtio'/>
</disk>
<interface type='bridge'>
<mac address='54:52:00:63:bf:8d'/>
<source bridge='br0'/>
<target dev='vnet0'/>
<model type='virtio'/>
</interface>
<serial type='pty'>
<source path='/dev/pts/1'/>
<target port='0'/>
</serial>
<console type='pty' tty='/dev/pts/1'>
<source path='/dev/pts/1'/>
<target port='0'/>
</console>
<input type='mouse' bus='ps2'/>
<graphics type='vnc' port='5900' autoport='yes' keymap='en-us'/>
<video>
<model type='cirrus' vram='9216' heads='1'/>
</video>
</devices>
<seclabel type='dynamic' model='apparmor'>
<label>libvirt-0f79ba7f-27bf-16a0-5887-6cfa2b5569f1</label>
<imagelabel>libvirt-0f79ba7f-27bf-16a0-5887-6cfa2b5569f1</imagelabel>
</seclabel>
</domain>
virsh # version
Compiled against library: libvir 0.7.0
Using library: libvir 0.7.0
Using API: QEMU 0.7.0
Running hypervisor: QEMU 0.11.0
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