Re: [Qemu-devel] [PATCH v2 1/4] qmp: Introduce blockdev-change-medium

[Max Reitz]

On 2014-12-05 at 14:10, Eric Blake wrote:
> On 12/05/2014 03:08 AM, Max Reitz wrote:
> > Introduce a new QMP command 'blockdev-change-medium' which is intended
> > to replace the 'change' command for block devices. The existing function
> > qmp_change_blockdev() is accordingly renamed to
> > qmp_blockdev_change_medium().
> >
> > Signed-off-by: Max Reitz <address@hidden>
> > ---
> >   blockdev.c                |  7 ++++---
> >   include/sysemu/blockdev.h |  2 --
> >   qapi/block-core.json      | 21 +++++++++++++++++++++
> >   qmp-commands.hx           | 31 +++++++++++++++++++++++++++++++
> >   qmp.c                     |  2 +-
> >   5 files changed, 57 insertions(+), 6 deletions(-)
> I like it!

Good :-)

> >   
> >   ##
> > +# @blockdev-change-medium:
> > +#
> > +# Changes the medium inserted into a block device by ejecting the current 
> > medium
> > +# and loading a new image file which is inserted as the new medium.
> > +#
> > +# @device:      block device name
> > +#
> > +# @filename:    filename of the new image to be loaded
> > +#
> > +# @format:      #optional, format to open the new image with (defaults to the
> > +#               probed format)
> > +#
> > +# Since: 2.3
> > +##
> > +{ 'command': 'blockdev-change-medium',
> > +  'data': { 'device': 'str',
> > +            'filename': 'str',
> > +            '*format': 'str' } }
> Someday, we should quit open-coding format as 'str' and instead make it
> an enum; but that is a separate patch series, and can get this location
> as part of that series.
>
> Should there be a way to empty a cdrom drive?  That is, how do I change
> a drive from visiting a file to being empty?

Doesn't 'eject' work?

> Does passing the empty
> string for mandatory 'filename' do that, or should we be strict and
> state that filename is optional (omit to empty the drive) and that an
> empty string as filename is forbidden?
>
> Please also improve the documentation in qapi-schema.json to have the
> 'change' command mention that it is kept for backwards compatibility,
> but that it is no longer the preferred command and point users to
> 'blockdev-change-medium'.

And to 'change-vnc-password'. Will do.

Max