Re: [kvm-unit-tests PATCH v1 2/2] s390x: create persistent comm-key

Nico Boehr
2022-07-22T07:31:13Z

Quoting Claudio Imbrenda (2022-07-21 18:32:45)
> On Thu, 21 Jul 2022 15:26:47 +0200
> Nico Boehr <nrb@linux.ibm.com> wrote:
>
> > To decrypt the dump of a PV guest, the comm-key (CCK) is required. Until
> > now, no comm-key was provided to genprotimg, therefore decrypting the
> > dump of a kvm-unit-test under PV was not possible.
> >
> > This patch makes sure that we create a random CCK if there's no
> > $(TEST_DIR)/comm.key file.
> >
> > Also allow dumping of PV tests by passing the appropriate PCF to
> > genprotimg (bit 34). --x-pcf is used to be compatible with older
> > genprotimg versions, which don't support --enable-dump. 0xe0 is the
> > default PCF value and only bit 34 is added.
> >
> > Unfortunately, recent versions of genprotimg removed the --x-comm-key
> > argument which was used by older versions to specify the CCK. To support
> > these versions, we need to parse the genprotimg help output and decide
> > which argument to use.
>
> I wonder if we can simply support only the newest version?
> would make the code cleaner, and updating genprotimg is not too
> complicated

I would be annoyed by having to compile s390-tools every time I want to run PV tests on older distros.

If we want to avoid the --help parsing stuff, we could add a configure option to disable PV dump support. Not sure if it's a good idea.