On Tue, Jun 21, 2022 at 8:53 PM David Gow <davidgow@xxxxxxxxxx> wrote: > > There are several tests which depend on PCI, and hence need a bunch of > extra options to run under UML. This makes it awkward to give > configuration instructions (whether in documentation, or as part of a > .kunitconfig file), as two separate, incompatible sets of config options > are required for UML and "most other architectures". > > For non-UML architectures, it's possible to add default kconfig options > via the qemu_config python files, but there's no equivalent for UML. Add > a new tools/testing/kunit/configs/arch_uml.config file containing extra > kconfig options to use on UML. > > Signed-off-by: David Gow <davidgow@xxxxxxxxxx> > --- > > It's really ugly to have to type: > --kconfig_add CONFIG_VIRTIO_UML=y > --kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y > when running many tests under UML, particularly since it isn't required > on other architectures. > > This came up in discussion with Daniel this morning, and while the > ability to repeat the --kunitconfig flag would go some way to alleviate > this, having to add: > --kunitconfig ./tools/testing/kunit/config/uml_pci.kunitconfig > isn't all that much better. > > So it seems like adding something by default would be nice. > > This implementation is not perfect (in particular, there's no easy way > of _disabling_ these options now, though [1] probably will help). The I assume the missing link for [1] is https://lore.kernel.org/linux-kselftest/20220520224200.3764027-1-dlatypov@xxxxxxxxxx/ Note that we'll have to update one of these patches depending on the order they go in. [1] had to change make_arch_qemuconfig() to ensure that arch/qemu configs have *lower* priority than user-specified overrides. So we'll either need to do the same here or update [1] for this to work out. > 'arch_uml.config' filename can be bikeshedded, too. > > Thoughts? I was initially against effectively hard-coding these in, but it feels like making CONFIG_PCI=y work by default on UML is worth it. We've talked about architecture-specific options in kunitconfig files and it's only ever been about PCI. Nothing else has come up yet, so this patch would eliminate that concern for now.
