On 27/07/18 11:47, Paolo Bonzini wrote:
On 27/07/2018 12:43, Mark Cave-Ayland wrote:
The issue here seems to be that according to "info qtree" there is
*always* an ide-cd device plugged into the location equivalent to that
of -cdrom, and so with the above command QEMU ends up adding a second
ide-cd device to the ide.1 bus which confuses OpenBIOS. Is this
deliberate behaviour?
Yes, the default CD-ROM is always placed as secondary/master.
If you use -device ide-cd the implicit CD-ROM should go away. However,
-drive alone doesn't have that effect (probably for backwards
compatibility reasons, this predates me even though by only a few months).
I see, thanks for the detailed explanation. So in that case shouldn't
the following work?
$ ./qemu-system-ppc -drive
id=cd,file=MacOS921-macsbug.iso,if=ide,media=cdrom -device
ide-cd,drive=cd,bootindex=0 -nographic -prom-env 'auto-boot?=false'
qemu-system-ppc: -device ide-cd,drive=cd,bootindex=0: Drive 'cd' is
already in use because it has been automatically connected to another
device (did you need 'if=none' in the drive options?)
From what I can see you must have if=ide present so that the code will
take into account that the machine block_default_type is set to IF_IDE
and understand it's the existing internal IDE buses that need to be
(re)used?
Alternatively, you can use -nodefaults of course.
For the moment I'd like to come up with equivalents to the -hda and
-cdrom options to allow users to switch to the new syntax, and of course
this is all a pre-cursor to adding virtio support to OpenBIOS :)
It seems to me that -nodefaults is intended more for tools like libvirt
that want to build up a machine from scratch, although again there is
always the issue as to how to handle internal devices i.e. the
difference between plugging a drive into an internal IDE interface vs.
adding one into a spare PCI slot via -device and instead plugging the
drive into that.
ATB,
Mark.
