Comment # 4 on bug 1070478 from James Fehlig

(In reply to Walddys Emmanuel Dorrejo C�spedes from comment #2)
> <disk type='file' device='disk'>
>   <driver name='qemu' type='raw'/>
>   <source file='/home/wedc/VMs/crs.img'/>
>   <target dev='vdb' bus='virtio'/>
>   <shareable/>
>   <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
> </disk>

This XML snippet of your disk device is correct. The <shareable> element should
allow the disk to be shared. But as Fei noted, your libvirt is not passing
'share-rw=on' when invoking qemu. There is an upstream patch to fix it, which
will be included in the upcoming libvirt 3.10.0 release.