Markus Armbruster <arm...@redhat.com> writes:
> = Introduction =
>
> BDSes can be opened in various ways. Some of them don't provide for
> user configuration. Some of them should.
>
> Example: -drive format=qcow2,file=foo.qcow2 where foo.qcow2 has a raw
> backing file foo.raw. This creates the the following tree of BDSes:
>
> (qcow2,foo.qcow2)
> / \
> (file,foo.qcow2) (raw,foo.raw)
> |
> (file,foo.raw)
>
> Before Kevin added driver-specific options, -drive let you configure
> basically just the root. Configuration for the others was inferred from
> the root's configuration and the images. Driver-specific options let
> you configure all the nodes. Defaults are still inferred as before.
>
> Example: blockdev-snapshot-sync provides only a small subset of the full
> configuration options for the BDS it creates. Could be fixed by
> duplicating the full options, i.e. blockdev-add's. But a command that
> just snapshots and leaves BDS creation to blockdev-add would be cleaner.
>
> This is a systematic review of all the ways you can open BDSes in qemu
> proper, i.e. not in qemu-{img,io,nbd}. I tracked them down by following
> the call chains leading to bdrv_open().
Forgot to mention: I ignored HMP commands, too.
[...]
