Hello,

I try to use the virtio-scsi driver to use my disks. But my setup at first:
The new kernel and dirty things from Jessie are for discard support (also not working with current configuration despite thin volumes with working discard). Once I have the this "new" qemu version, why not to use virtio...

Every disk with target bus "scsi" gets an own scsi-hd device. Libvirt ignores the scsi controller of type virtio-scsi.
Here is a XML snippet:
<devices>
<controller type='scsi' model='virtio-scsi' index="0"/>
<disk type="block" device="disk">
    <source dev="/dev/ssd0/sarabi"/>
    <driver discard="unmap"/>
    <target dev="sda" bus="scsi"/>
    <address type="drive" controller="0" bus=0/>
</disk>
</devices>

This creates the virtio-scsi controller (verified by lspci in guest) but do not "connect" the disks to it. The resulting command line looks following:
kvm [...] -device virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0x5 -drive file=/dev/ssd0/sarabi,if=none,id=drive-scsi0-0-0-0,format=raw,discard=unmap -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=2 [...]

How get my disk to run over virtio-scsi? Or did I found something like a bug?

Bye Markus