On Tue, Jan 14, 2020 at 04:25:44PM +0100, Max Reitz wrote:
> On 09.01.20 12:10, Stefan Hajnoczi wrote:
> > The qcow2 .bdrv_measure() code calculates the crypto payload offset.
> > This logic really belongs in block/crypto.c where it can be reused by
> > other image formats.
> > 
> > The "luks" block driver will need this same logic in order to implement
> > .bdrv_measure(), so extract the block_crypto_calculate_payload_offset()
> > function now.
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >  block/crypto.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  block/crypto.h |  5 ++++
> >  block/qcow2.c  | 59 ++++------------------------------------------
> >  3 files changed, 73 insertions(+), 55 deletions(-)
> > 
> > diff --git a/block/crypto.c b/block/crypto.c
> > index 24823835c1..ed32202fa2 100644
> > --- a/block/crypto.c
> > +++ b/block/crypto.c
> > @@ -185,6 +185,70 @@ block_crypto_create_opts_init(QDict *opts, Error **errp)
> 
> [...]
> 
> > +/* Determine the number of bytes for the crypto header */
> > +bool block_crypto_calculate_payload_offset(QemuOpts *opts,
> > +                                           const char *optprefix,
> > +                                           size_t *len,
> > +                                           Error **errp)
> > +{
> > +    QDict *cryptoopts_qdict;
> > +    QCryptoBlockCreateOptions *cryptoopts;
> > +    QCryptoBlock *crypto;
> > +
> > +    /* Extract options into a qdict */
> > +    if (optprefix) {
> > +        QDict *opts_qdict = qemu_opts_to_qdict(opts, NULL);
> > +
> > +        qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, optprefix);
> > +        qobject_unref(opts_qdict);
> > +    } else {
> > +        cryptoopts_qdict = qemu_opts_to_qdict(opts, NULL);
> > +    }
> > +
> > +    /* Build QCryptoBlockCreateOptions object from qdict */
> > +    qdict_put_str(cryptoopts_qdict, "format", "luks");
> 
> Should this be a parameter?

Maybe one day, but there are no users who need it yet.

Stefan