Re: [libvirt] [PATCH 10/11] Rewrite qemu-img backing store format handling

When creating qcow2 files with a backing store, it is important to set an explicit format to prevent QEMU probing. The storage backend was only doing this if it found a 'kvm-img' binary. This is wrong because plenty of kvm-img binaries don't support an explicit format, and plenty of 'qemu-img' binaries do support a format. The result was that most qcow2 files were not getting a backing store format. This patch runs 'qemu-img -h' to check for the two support argument formats '-o backing_format=raw' '-F raw' and use whichever option it finds * src/storage/storage_backend.c: Query binary to determine how to set the backing store format --- src/storage/storage_backend.c | 214 +++++++++++++++++++++++++++++------------ 1 files changed, 152 insertions(+), 62 deletions(-)