My proposal [1] to add an autoclear all-zero-content bit to the qcow2 format has now stalled into 5.1 territory, but several patches in my initial proposal are uncontroversial and obvious bug fixes worth having in 5.0.
[1] https://lists.gnu.org/archive/html/qemu-devel/2020-01/msg08075.html Eric Blake (4): qcow2: Comment typo fixes qcow2: List autoclear bit names in header qcow2: Avoid feature name extension on small cluster size sheepdog: Consistently set bdrv_has_zero_init_truncate docs/interop/qcow2.txt | 3 ++- block/qcow2.c | 29 +++++++++++++++++++++++------ block/sheepdog.c | 2 ++ tests/qemu-iotests/031.out | 8 ++++---- tests/qemu-iotests/036 | 6 ++++-- tests/qemu-iotests/036.out | 4 ++-- tests/qemu-iotests/061 | 6 ++++-- tests/qemu-iotests/061.out | 14 +++++++------- 8 files changed, 48 insertions(+), 24 deletions(-) -- 2.26.0.rc2