Re: [libvirt] [PATCH 0/3] libxl: Add a test suite for libxl_domain_config generator

On Fri, Jul 14, 2017 at 05:59:57PM -0600, Jim Fehlig wrote: > On 07/01/2017 08:16 PM, Marek Marczykowski-Górecki wrote: >> On Sun, Feb 26, 2017 at 07:02:24PM -0700, Jim Fehlig wrote: >>> Long ago danpb posted some patches to test libvirt domXML to >>> libxl_domain_config conversion >>> >>> https://www.redhat.com/archives/libvir-list/2014-May/msg01102.html >>> >>> Some of the prerequisite patches were pushed, but we've never managed >>> to push patches actually providing the conversion tests. I sent several >>> follow-ups to Dan's work but never converged on a satisfactory solution >>> for all the Xen versions supported by libvirt. The last attempt was in >>> Sept 2014 >>> >>> https://www.redhat.com/archives/libvir-list/2014-September/msg00698.html >>> >>> I tried to revive the work in Jan 2015, but that also stalled >>> >>> https://www.redhat.com/archives/libvir-list/2015-January/msg00924.html >>> >>> Fast-forward over 2.5 years from the first attempt and libvirt no longer >>> supports older Xen versions 4.2 and 4.3 that were proving to be problematic. >>> Starting with Xen 4.5 libxl added support for libxl_domain_config_from_json, >>> which provides a way to implement the conversion tests that work with all >>> Xen versions >= 4.5 (including latest xen.git master). >> >> Few more months have passed... > > And a few more weeks :-). Sorry for the delay. Slowly catching up on libvirt > mail after some time away... It's me this time... >> FWIW, I've tested it with Xen 4.6. The patch needs very minor update: >> - s/VIRT_TEST_MAIN_PRELOAD/VIR_TEST_MAIN_PRELOAD/ >> - add xencaps argument to libxlBuildDomainConfig cal > >> >> After that, it works! When I made some test to fail, reported error is >> not so helpful ("libvirt: Xen Light Driver error : internal error: >> Expected and actual libxl_domain_config objects do not compare"), but it >> do catch failures. >> Then, if I change strcmp to virTestCompareToString, the output is much >> more helpful. > > Thanks for the improvements. I noticed you included them in your V2 of patch > 3/3. I assume you needed patches 1 and 2 as well? Yes, in this tests shape. But see below. >> I'd really love to have it merged, mostly because I want to add more tests >> using this framework (see "Add setting CPU features (CPUID) with >> libxenlight driver" thread). > > I really dislike patches 1 and 2. They remove very useful checks IMO. > Shortly after posting the series in Feb, I tried mocking the emulator > checks. I failed quite a bit before coming up with something that worked, > yet not so satisfying :-). I'll attach the (now rather old) patches for > reference. My independent try to this test approach ("tests: check domain XML to libxl structures conversion") had much simpler (but uglier) solution for this problem: use /bin/true as emulator path (replaced in runtime, just after loading XML from file).

> Do you have time to update these old patches, test, and repost to the list? > Or perhaps have better ideas on mocking, or approaches that avoid the need > for 1/3 and 2/3. If using /bin/true as emulator path is acceptable, I can finish this and post updated version.