Re: [Qemu-devel] [PATCH v9 07/11] block: Add QMP support for streaming to an intermediate layer

[Alberto Garcia]

On Tue 03 May 2016 03:18:39 PM CEST, Kevin Wolf wrote:
>> > On the other hand, this code assumes that there is only a single
>> > top-level node. This isn't necessarily true any more these days.
>> 
>> Hmm... if you give me an example I can test that scenario.
>
> Simply reference the same node twice:
>
> $ x86_64-softmmu/qemu-system-x86_64 \
> -drive if=none,file=/tmp/backing.qcow2,id=backing \
> -drive file=/tmp/test.qcow2,backing=backing,id=hda \
> -drive file=/tmp/test2.qcow2,backing=backing,id=hdb

You're right, but maybe we need to add additional checks to some of the
existing commands then, because if you run e.g block-commit on hda
you're gonna corrupt hdb.

Berto