[libvirt] [PATCHv1 0/5] qcow3 support

[Ján Tomko]

This adds support for qcow3 to storage and qemu drivers (except for
snapshots, I still need to do that).

Qcow3 adds feature bits for compatible, incompatible and autoclear features.
I'm not sure if it makes sense to differentiate between them in the XML.
If yes, perhaps unknown incompatible features might result in an error, while
we could just warn about unknown compatible ones.
If not, one bitmap should be enough to track the ones that interest us.

There are two feature bits so far: lazy_refcounts (delayed refcount updates)
and a dirty bit (refcounts haven't been updated and older QEMU can't read this).
If we knew what features are supported by QEMU, we could refuse to use them,
however I don't know about other way to find out than running:
qemu-img create -f qcow2 -o ? /dev/null
If we don't know, I don't think it's any good to find out the dirty bit value.

Ján Tomko (5):
  storage: refactor qemu-img command line generation
  storage: use virBuffer for generating qemu options string
  util: add qcow3 format probing
  conf: add format features to target XML
  qemu: add support for creating and using qcow3 images

 src/conf/storage_conf.c          |   90 +++++++++++++++++++++++++++++
 src/conf/storage_conf.h          |    3 +
 src/libvirt_private.syms         |    3 +
 src/qemu/qemu_command.c          |    2 +-
 src/qemu/qemu_hotplug.c          |    4 +-
 src/storage/storage_backend.c    |  106 ++++++++++++++++++-----------------
 src/storage/storage_backend_fs.c |    7 ++
 src/util/virstoragefile.c        |  116 ++++++++++++++++++++++++++++++++++++--
 src/util/virstoragefile.h        |   27 +++++++++
 9 files changed, 298 insertions(+), 60 deletions(-)

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1.7.8.6