On Fri, Mar 22, 2019 at 10:47 PM Eric Blake <ebl...@redhat.com> wrote:
> On 3/22/19 3:22 PM, Nir Soffer wrote: > > > Thanks for fixing this! This will be a very important performance fix for > > importing > > VMs. > > > > The change description sounds good to me. > > > > Can you make these patches available on some git repo to make it easy to > > test? > > Based on commit titles, this branch looks reasonably close (at the moment): > > https://repo.or.cz/qemu/kevin.git/shortlog/refs/heads/qcow2-data-file I tested the patches and they work correctly with NBD server (tested both nbdkit and qemu-nbd), skipping pre zero step, and zeroing only the unallocated areas. However zeroing is always done without BDRV_REQ_MAY_UNMAP, creating fully allocated images when the expected result is sparse image. I posted a patch with possible fix, explaining this issue with mode details. I don't see it yest in mail archive, but the patch is available here: https://github.com/nirs/qemu/commit/5023405ee42dc0d8e9a03ac03d247079f719b455 Nir
