Re: [Qemu-devel] [PATCH v5 06/11] block: add drive-backup QMP command

[Kevin Wolf <kwolf@redhat.com>]

Am 20.06.2013 um 14:19 hat Stefan Hajnoczi geschrieben:
> On Wed, Jun 19, 2013 at 01:07:42PM +0200, Kevin Wolf wrote:
> > Am 30.05.2013 um 14:34 hat Stefan Hajnoczi geschrieben:
> > > @drive-backup
> > > 
> > > Start a point-in-time copy of a block device to a new destination.  The
> > > status of ongoing drive-backup operations can be checked with
> > > query-block-jobs where the BlockJobInfo.type field has the value 'backup'.
> > > The operation can be stopped before it has completed using the
> > > block-job-cancel command.
> > > 
> > > @device: the name of the device which should be copied.
> > > 
> > > @target: the target of the new image. If the file exists, or if it
> > >          is a device, the existing file/device will be used as the new
> > >          destination.  If it does not exist, a new file will be created.
> > > 
> > > @format: #optional the format of the new destination, default is to
> > >          probe if @mode is 'existing', else the format of the source
> > > 
> > > @mode: #optional whether and how QEMU should create a new image, default is
> > >        'absolute-paths'.
> > > 
> > > @speed: #optional the maximum speed, in bytes per second
> > > 
> > > @on-source-error: #optional the action to take on an error on the source,
> > >                   default 'report'.  'stop' and 'enospc' can only be used
> > >                   if the block device supports io-status (see BlockInfo).
> > > 
> > > @on-target-error: #optional the action to take on an error on the target,
> > >                   default 'report' (no limitations, since this applies to
> > >                   a different block device than @device).
> > > 
> > > Note that @on-source-error and @on-target-error only affect background I/O.
> > > If an error occurs during a guest write request, the device's rerror/werror
> > > actions will be used.
> > > 
> > > Returns: nothing on success
> > >          If @device is not a valid block device, DeviceNotFound
> > > 
> > > Since 1.6
> > > 
> > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > 
> > Reviewed-by: Kevin Wolf <kwolf@redhat.com>
> > 
> > But what about HMP, the series doesn't seem to have a separate patch to
> > add a command there?
> 
> I can send it as a follow-up if you want.  The test cases use QMP and so
> do management tools - I didn't feel the need for HMP.

Yes, please do. HMP is what plain qemu users use. I wouldn't consider it
legacy - quite the opposite: Having QMP as a stable machine-readable
protocol gives us more freedom to make HMP a good interface for human
users.

Kevin