Re: [Qemu-devel] [PATCH] block: Expose host_* drivers in blockdev-add

[Kevin Wolf]

Am 24.04.2014 um 09:27 hat Markus Armbruster geschrieben:
> Kevin Wolf <address@hidden> writes:
> 
> > Am 23.04.2014 um 17:34 hat Eric Blake geschrieben:
> >> On 04/23/2014 09:12 AM, Kevin Wolf wrote:
> >> > All the functionality to use the host_device, host_cdrom and host_floppy
> >> > drivers is already there, they just need to be added to the schema.
> >> > 
> >> > Signed-off-by: Kevin Wolf <address@hidden>
> >> > ---
> >> >  qapi-schema.json | 6 +++++-
> >> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >> > 
> >> > diff --git a/qapi-schema.json b/qapi-schema.json
> >> > index 391356f..0fc0f12 100644
> >> > --- a/qapi-schema.json
> >> > +++ b/qapi-schema.json
> >> > @@ -4288,7 +4288,8 @@
> >> >  # Since: 2.0
> >> 
> >> We haven't been good at tracking enum growth, but it can't hurt to try.
> >>  It might be worth changing this line to read:
> >> 
> >> # Since: 2.0, 'host_device', 'host_cdrom', 'host_floppy' since 2.1
> >
> > I'm fine with documenting the changes, but this format doesn't look like
> > it works very well in the long term.
> >
> >> >  ##
> >> >  { 'enum': 'BlockdevDriver',
> >> > - 'data': [ 'file', 'http', 'https', 'ftp', 'ftps', 'tftp',
> >> > vvfat', 'blkdebug',
> >> > +  'data': [ 'file', 'host_device', 'host_cdrom', 'host_floppy',
> >> 
> >> Any reason you used _ instead of - in these names?  Newer QMP tends to
> >> prefer - unless there is a good reason why _ has already been baked in
> >> due to back-compat.
> >
> > The block driver has always been called host_device with an underscore.
> > We can't change it because that would break compatibility on the command
> > line.
> 
> A simple indirection could buy us a little more consistency in QMP.  If
> you say that's not worth the trouble because there's so much
> inconsistency already, you have a point.  I still hate it, though :)

Is inconsistency between block device configuration in QMP and block
device configuration on the command line any better than inconsistency
between one QMP command and part of the other QMP commands?

> Probably the only way to stop the proliferation of this '-' vs. '_'
> nuisance is to accept both '-' and '_' everywhere in QMP, and use only
> '-' in documentation.  Clearly beyond the scope of your patch.

Not sure how hard this would be to implement, but I agree that this
would be the best solution.

Kevin