Re: [Qemu-devel] [PATCH v2 0/3] blockdev: Defer creation of implicit PCI devices for IF_VIRTIO drives

[Peter Maydell]

On 9 June 2015 at 18:48, Peter Maydell <address@hidden> wrote:
> Patch 3 is the one-liner to change the default-drive-type. Unfortunately
> just doing that alone will break commandlines that currently work

The other problem with taking patch 3 alone is that it completely
breaks everything, because:
 * by default we create a "cdrom" drive whose type is <board-default>
   and which has no media inserted
 * the virtio-blk device barfs if you give it a drive with no media:
   "Device needs media, but drive is empty"

The S390 systems get around this by specifying no_cdrom = 1, but
it doesn't seem terribly satisfactory that this has to be manually
done by any machine with a virtio default drive type...

-- PMM