On Tue, May 16, 2023 at 11:32:27PM +0900, ~akihirosuda wrote: > > From: Akihiro Suda <akihiro.suda...@hco.ntt.co.jp> > > "zlib" clusters are actually raw deflate (RFC1951) clusters without > zlib headers. > > Signed-off-by: Akihiro Suda <akihiro.suda...@hco.ntt.co.jp> > --- > docs/interop/qcow2.txt | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-)
Seems like a useful clarification to me (there's a difference between the encoding name and the program used to create/parse that encoding). Reviewed-by: Eric Blake <ebl...@redhat.com> > > diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt > index f7dc304ff6..e7f036c286 100644 > --- a/docs/interop/qcow2.txt > +++ b/docs/interop/qcow2.txt > @@ -214,14 +214,18 @@ version 2. > type. > > If the incompatible bit "Compression type" is set: the > field > - must be present and non-zero (which means non-zlib > + must be present and non-zero (which means non-deflate > compression type). Otherwise, this field must not be > present > - or must be zero (which means zlib). > + or must be zero (which means deflate). > > Available compression type values: > - 0: zlib <https://www.zlib.net/> > + 0: deflate <https://www.ietf.org/rfc/rfc1951.txt> > 1: zstd <http://github.com/facebook/zstd> > > + The deflate compression type is called "zlib" > + <https://www.zlib.net/> in QEMU. However, clusters with > the > + deflate compression type do not have zlib headers. > + > > === Header padding === > > -- > 2.38.4 > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
