Re: [Qemu-devel] [PATCH v2] docs/specs/qcow2.txt: fix incorrect bits of offsets in entries

[Hu Tao]

On Mon, Jan 20, 2014 at 10:10:22AM +0100, Kevin Wolf wrote:
> Am 17.01.2014 um 08:40 hat Stefan Hajnoczi geschrieben:
> > On Mon, Dec 30, 2013 at 04:00:17PM +0800, Hu Tao wrote:
> > > Fix incorrect bits of offsets in refcount table entry, l1 table
> > > entry and l2 table entry. See REFT_OFFSET_MASK, L1E_OFFSET_MASK
> > > and L2E_OFFSET_MASK.
> > > 
> > > Fix a typo while at the file.
> > > 
> > > Signed-off-by: Hu Tao <address@hidden>
> > > ---
> > > 
> > > v2: update comments as well.
> > > 
> > >  docs/specs/qcow2.txt | 14 +++++++-------
> > >  1 file changed, 7 insertions(+), 7 deletions(-)
> > 
> > Thanks, applied to my block tree:
> > https://github.com/stefanha/qemu/commits/block
> 
> This patch is wrong. It's the qcow2.h #defines that need to be fixed,
> not the spec. The smallest possible cluster size is 512 bytes, i.e.
> nine zero bits at the end, not just eight.

You're right. Thanks to bit 8 in these entries are reserved as zero,
we're not running into problem with wrong masks.