Am 23.09.2025 um 20:09 hat Eric Blake geschrieben: > On Tue, Sep 23, 2025 at 06:37:35PM +0200, Kevin Wolf wrote: > > Add a new --limits option to 'qemu-img info' that displays the block > > limits for the image and all of its children, making the information > > more accessible for human users than in QMP. This option is not enabled > > by default because it can be a lot of output that isn't usually relevant > > if you're not specifically trying to diagnose some I/O problem. > > > > This makes the same information automatically also available in HMP > > 'info block -v'. > > > > Signed-off-by: Kevin Wolf <kw...@redhat.com> > > --- > > docs/tools/qemu-img.rst | 6 +++++- > > include/block/qapi.h | 2 +- > > block/qapi.c | 34 ++++++++++++++++++++++++++++++++-- > > qemu-img.c | 15 ++++++++++++--- > > qemu-img-cmds.hx | 4 ++-- > > 5 files changed, 52 insertions(+), 9 deletions(-) > > > > > +++ b/qemu-img.c > > > @@ -3119,6 +3123,8 @@ static int img_info(const img_cmd_t *ccmd, int argc, > > char **argv) > > " display information about the backing chain for copy-on-write > > overlays\n" > > " -U, --force-share\n" > > " open image in shared mode for concurrent access\n" > > +" --limits\n" > > +" show detected block limits (may depend on options, e.g. cache > > mode)\n" > > I'm trying to figure out how the parenthetical helps the --help > message. The fact that it is detected limits already implies that > anything else (like cache mode) that can change what gets detected > would have an impact. So I think it would be fine to just use " show > detected block limits\n".
Yes, other options can influence the limits, too. I just thought that the most common pitfall for users will be that they actually want to know the limits for cache=none because that's what their VM uses, but 'qemu-img info' returns them for cache=writeback. So it felt helpful to add the note. But if you think that we'd better leave it out, I can remove it. Actually, this reminds me that I wanted to add a -t <cache_mode> option to 'qemu-img info', too, so that you can actually get the interesting information without using --image-opts. That will be something for a separate patch, though. Kevin
