Booting vdi image on virtualbox using libvirt

I am not able to boot a vdi image on virtualbox using libvirt .It keeps showing me "Bootable medium not found". I have tried booting it manually with virtualbox GUI and it boots without any problem. May there is some problem with my libvirt domain XML .

---

<os> 
<type>hvm</type> 
<boot dev='hd'/>       开发者_C百科    
</os> 

---

<devices>
<disk type='file' device='disk'> 
<source file='disk.vdi'/> 
<target dev='hdd'/> 
</disk>
</devices>

---

i would try to convert image to another format just to make sure that everything is ok

try something like that: qemu-img convert -f vdi disk.vdi -O qcow2 disk.qcow2 and then: qemu-kvm disk.qcow2 -m 1024