Am 09.03.2018 um 22:58 hat Eric Blake geschrieben: > On 03/09/2018 03:46 PM, Kevin Wolf wrote: > > This adds the .bdrv_co_create driver callback to qcow, which > > enables image creation over QMP. > > > > Signed-off-by: Kevin Wolf <[email protected]> > > --- > > qapi/block-core.json | 21 +++++- > > block/qcow.c | 196 > > ++++++++++++++++++++++++++++++++++----------------- > > 2 files changed, 150 insertions(+), 67 deletions(-) > > Pre-review question: do we REALLY want to support creation of new qcow > images from QMP? Or are we at the point where we want to declare qcow > a read-only format where we only support it to the extent that you can > convert an existing qcow file into a better supported format like > qcow2?
I don't think we want read-only formats if it can be avoided, because we're in a much worse position to run tests then. The other option you mentioned in your reply to the qed patch, just not implementing .bdrv_co_create, but keeping the old callback, would mean that we'd be stuck in a half-converted state forever. My goal is to get rid of .bdrv_co_create_opts in the long run. And actually, qcow and qed were two of the simpler conversions where little remains to be done before the logic in .bdrv_co_create_opts can be generalised in block.c. So I'd just do the conversion. Kevin
