Re: [Qemu-devel] [PATCH v3 2/8] block: set snapshot option for block devices in blkreplay module

[Paolo Bonzini]

On 20/09/2016 14:43, Pavel Dovgalyuk wrote:
> > No, this is unnecessary.  The image is unused in this case, so you can
> > specify the overlay as image=foo.qcow2.
>
> This branch allows user do not bother about overlays at all.
> Driver will automatically create temporary snapshot.

See other message.  There is already a way to do this in QEMU, which is
-snapshot.  I think it's a requirement that -snapshot works, and also
that your temporary overlay is implemented on top of -snapshot.

You can add some magic ways to enable -snapshot if you want, of course.

Paolo