Configuring a VFIO DASD as IPL device

Boot a guest from a VFIO pass-through DASD.

Before you begin

Prepare your device with a root file system and a bootable kernel.

Procedure

Configure the DASD with the root file system as a persistent device, see Configuring a pass-through DASD.
Per default, the guest is booted from the first specified disk device in the current libvirt-internal configuration. To avoid possible errors, explicitly specify the boot device with the boot element in the disk device definition (see <boot>).

boot order attribute: <number>

The guest is booted from the disk with the lowest specified boot order value.

If the specified device has a boot menu configuration, you can use the loadparm attribute of the boot element to specify a particular menu entry to be booted.

boot loadparm attribute: <selection>

boot order attribute:	`<number>`

boot loadparm attribute:	`<selection>`

Example

The following domain configuration-XML configures a virtual server V3, which is booted from a VFIO pass-through DASD 00a1:

<domain type="kvm">
    <name>V3</name>
    ...
    <devices>
        ...
        <hostdev mode="subsystem" type="mdev" model="vfio-ccw">
           <source>
              <address uuid="90c6c135-ad44-41d0-b1b7-bae47de48627"/>
           </source>
           <address type="ccw" cssid="0xfe" ssid="0x0" devno="0x00a1"/>
           <boot order="1"/>
       </hostdev>
        ...
    </devices>
</domain>

Note: Make sure the device with boot order="1" is valid and accessible before you start the virtual machine. On IBM Z, if the device with boot order="1" is not valid, the virtual machine does not try the next device and fails to boot.