Re: [Qemu-devel] How to specify the full block driver tree on the CLI ?

[Kevin Wolf <kwolf@redhat.com>]

Am 29.10.2015 um 09:15 hat Daniel P. Berrange geschrieben:
> On Thu, Oct 29, 2015 at 09:11:15AM +0100, Kevin Wolf wrote:
> > In qemu proper, you can use a dot syntax for -drive instead:
> > 
> >     qemu-system-x86_64 -drive \
> >     driver=luks,\
> >     secret=x,\
> >     file.driver=file,\
> >     file.filename=test.luks
> > 
> > In qemu-io, you can't use such syntax on the command line, but the open
> > command supports an -o option that accepts the same dot syntax.
> > 
> > Note that qemu-img can't deal with this stuff yet, so you'll have
> > trouble creating an image with such a specification. I guess you need to
> > create it as a local file first and then use non-qemu tools to copy it
> > somewhere where it's exported by rbd, iscsi or gluster.
> 
> I wonder if my patches to qemu-io & qemu-img here do the right thing to
> make this dot syntax work....
> 
>    https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg04382.html
>    https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg04375.html

I haven't looked at the series in detail yet, but considering that it's
probably harder to prevent it from working than getting it, I assume
that your patches do allow it.

Just passing the options QDict to bdrv_open() is enough, nesting is
represented with the dot syntax in the keys there. In fact, if you use
blockdev-add in QMP, it first converts the options to a flattened QDict
with dot syntax for the keys before it processes it.

Kevin