[Qemu-devel] Re: [PATCH 3/5] blockdev: Reject multiple definitions for the same drive

[Kevin Wolf <kwolf@redhat.com>]

Am 21.01.2011 18:30, schrieb Markus Armbruster:
> Kevin Wolf <kwolf@redhat.com> writes:
> 
>> Am 21.01.2011 17:58, schrieb Markus Armbruster:
>>> Kevin Wolf <kwolf@redhat.com> writes:
>>>
>>>> Am 17.01.2011 19:31, schrieb Markus Armbruster:
>>>>> For reasons lost in the mist of time, we silently ignore multiple
>>>>> definitions for the same drive:
>>>>>
>>>>>     $ qemu-system-x86_64 -nodefaults -vnc :1 -S -monitor stdio -drive if=ide,index=1,file=tmp.qcow2 -drive if=ide,index=1,file=nonexistant
>>>>>     QEMU 0.13.50 monitor - type 'help' for more information
>>>>>     (qemu) info block
>>>>>     ide0-hd1: type=hd removable=0 file=tmp.qcow2 backing_file=tmp.img ro=0 drv=qcow2 encrypted=0
>>>>>
>>>>> With if=none, this can become quite confusing:
>>>>>
>>>>>     $ qemu-system-x86_64 -nodefaults -vnc :1 -S -monitor stdio -drive if=none,index=1,file=tmp.qcow2,id=eins -drive if=none,index=1,file=nonexistant,id=zwei -device ide-drive,drive=eins -device ide-drive,drive=zwei
>>>>>     qemu-system-x86_64: -device ide-drive,drive=zwei: Property 'ide-drive.drive' can't find value 'zwei'
>>>>>
>>>>> The second -device fails, because it refers to drive zwei, which got
>>>>> silently ignored.
>>>>>
>>>>> Make multiple drive definitions fail cleanly.
>>>>>
>>>>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>>>>
>>>> Dropped this one (and patch 5, which depends on it) from the block
>>>> branch again, it breaks -cdrom and probably other drives which are
>>>> created by default.
>>>
>>> --verbose?
>>>
>>> I was wondering what crap could depend on the crazy silent ignore...
>>
>> Just try using -cdrom and you'll see yourself.
> 
> Works for me.  Possibly due to some "it's late on Friday" stupidity on
> my part.
> 
>> >From what I understand, we always create the default device. If the user
>> has actually specified one, we still try to create the default device,
>> it fails and that failure was ignored until now (and with the patch
>> applied qemu aborts in this case).
> 
> Example command line for the mentally-challenged-on-Fridays?

$ x86_64-softmmu/qemu-system-x86_64 -cdrom /dev/null
qemu-system-x86_64: drive with bus=1, unit=0 (index=2) exists

Kevin