Re: [PATCH kvm-unit-tests 5/5] add hyperv_connections test

["Radim Krčmář" <rkrcmar@redhat.com>]

2017-06-14 16:21+0300, Roman Kagan:
> On Wed, Jun 14, 2017 at 02:59:51PM +0200, Radim Krčmář wrote:
> > 2017-06-14 15:01+0300, Roman Kagan:
> > > On Tue, Jun 13, 2017 at 09:28:59PM +0200, Radim Krčmář wrote:
> > > > 2017-06-06 22:19+0300, Roman Kagan:
> > > > > Add a test for Hyper-V message and event connections.
> > > > > 
> > > > > It requires QEMU with the extended test device supporting message end
> > > > > event connection test modes (recently posted on qemu-devel).  On older
> > > > > QEMU versions it fails.
> > > > 
> > > > Doesn't QEMU provide a way to detect this feature from the outside (some
> > > > command line magic) that we could use it to skip the test?
> > > 
> > > I didn't know there was such a trick.  However, I failed to figure out
> > > how to get it to work here: the -device options appeared to be
> > > interpreted after -kernel so it didn't cause a SKIP;
> > 
> > Hm, the test should be skipped if QEMU fails to start.
> 
> IIUC the SKIP is taken when QEMU is run with the command line as if in
> the real test, but with a -kernel option pointing at a non-existing
> file, and the error message contains that filename.

Yes, it's an ugly hack.

> The assumption is apparently that QEMU was ok with all other options.
> 
> The problem is that many options are interpreted after -kernel, so the
> skip-checking logic decides that QEMU is ok with the options but the
> actual test start shows that it's not, resulting in a FAIL.

I see, thanks, that is a bug.

Dropping the -kernel option in the check seems nicer than providing a
minimal working kernel ... I'll see how much refactoring is needed.