Re: [Qemu-devel] [PATCH v3 03/10] tests: Add vm test lib

[Fam Zheng <famz@redhat.com>]

On Tue, 08/22 08:19, Philippe Mathieu-Daudé wrote:
> > +    def add_source_dir(self, data_dir):
> > +        name = "data-" + hashlib.sha1(data_dir).hexdigest()[:5]
> > +        tarfile = os.path.join(self._tmpdir, name + ".tar")
> > +        logging.debug("Creating archive %s for data dir: %s", tarfile, data_dir)
> > +        subprocess.check_call(["tar", "--exclude-vcs",
> 
> --exclude-vcs-ignores will process .gitignore,

Sounds useful, thanks!

> you can also list with 'git ls-files',
> or generate tarball with scripts/make-release

They won't handle submodules, will they?

> 
> > +                               "--exclude=tests/vm/*.img",
> > +                               "--exclude=tests/vm/*.img.*",
> > +                               "--exclude=*.d",
> > +                               "--exclude=*.o",
> > +                               "--exclude=docker-src.*",
> > +                               "-cf", tarfile, '.'], cwd=data_dir,
> > +                              stdin=self._devnull, stdout=self._stdout)
> > +        self._data_args += ["-drive",
> > +                            "file=%s,if=none,id=%s,cache=writeback,format=raw" % \
> > +                                    (tarfile, name),
> > +                            "-device",
> > +                            "virtio-blk,drive=%s,serial=%s,bootindex=1" % (name, name)]
> 
> what about mounting readonly via '-device virtio-9p-pci' (not using
> tarball)?
> 

It doesn't work. That way an out-of-tree build is required in the guest, but if
an in-tree build has been done in host side, out-of-tree builds fail.  Also the
performance will be much worse, I believe: untar is sequential read, and after
that everything is in the guest page cache; with virtio-9p, there will be a
large amount of "random" requests between guest and host.

Fam