On 20.10.2014 at 14:48, Peter Lieven wrote:
On 20.10.2014 14:19, Max Reitz wrote:
On 2014-10-20 at 14:16, Peter Lieven wrote:
On 20.10.2014 13:51, Max Reitz wrote:
On 2014-10-20 at 12:03, Peter Lieven wrote:
[...]
Can you further help here. I think my problem was that I
don't have access to the commandline options in
bdrv_open?!
You do. It's the "options" QDict. :-)
Maybe I just don't get it.
If I specify
qemu -drive if=virtio,file=image.qcow2,write-merging=off
and check with
qdict_get_try_bool(options, "write-merging", true);
in bdrv_open() directly before bdrv_swap I always get true.
Hm, judging from fprintf(stderr, "%s\n",
qstring_get_str(qobject_to_json_pretty(QOBJECT(options))));,
it's there for me (directly after qdict_del(options,
"node-name"). The output is:
Qemu wrote:
{
"filename": "image.qcow2"
}
{
"write-merging": "off"
}
qemu-system-x86_64: -drive
if=virtio,file=image.qcow2,write-merging=off: could not open
disk image image.qcow2: Block format 'qcow2' used by device
'virtio0' doesn't support the option 'write-merging'
But as you can see, it's a string and not a bool. So the problem
is that there are (at least) two parameter "types" in qemu: One
is just giving a QDict, and the other are QemuOpts. QDicts are
just the raw user input and the user can only input strings, so
everything is just a string. As far as I know, typing everything
correctly is done by converting the QDict to a QemuOpts object
(as you can see in generally every block driver which supports
some options (e.g. qcow2) and also in blockdev_init(), it's
qemu_opts_absorb_qdict()).
Sooo, right, I forgot that. Currently, there are no non-string
non-block-driver-specific options for mid-tree BDS (in contrast
to the root BDS, which are parsed in blockdev_init()), so you
now have the honorable task of introducing such a QemuOptsList
along with qemu_opts_absorb_qdict() and everything to
bdrv_open_common(). *cough*