Hi Tazaki-san, CC arnd
On Fri, 19 Sept 2025 at 11:32, Hajime Tazaki <[email protected]> wrote: > On Fri, 19 Sep 2025 16:24:07 +0900, > Johannes Berg wrote: > > On Fri, 2025-09-19 at 09:03 +0900, Hajime Tazaki wrote: > > > > This doesn't make a lot of sense to me. Why would we even want to build > > > > PCI on NOMMU-UML if PCI in general is dependent on MMU now? > > > > > > > > It's not like ARCH=um with PCI and NOMMU has any value even for testing > > > > if such a configuration cannot exist in reality? > > > > > > totally understand your point. > > > > > > now I see that we don't have to have this work around by using > > > --kconfig_add option to kunit.py. > > > > > > # like --kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=n (in addition to > > > --kconfig_add CONFIG_MMU=n). > > > > That's not what I mean. I think it should be made impossible to build > > the broken code. > > okay. > # I think now I lost the point... > > currently, drivers/pci/Kconfig (CONFIG_PCI) marks as depends on MMU, > so we cannot select it when CONFIG_MMU=n. That is a fairly recent change, see commit 8fe743b5eba0abfb ("PCI: Add CONFIG_MMU dependency") in v6.16-rc1. As this is not a "hard" dependency, perhaps it should be reverted, iff you are willing to take care of the casual breakage? > > but it's different with kunit when using them via kunit.py config, > > it first adds > > CONFIG_VIRTIO_UML=y > CONFIG_UML_PCI_OVER_VIRTIO=y > > via tools/testing/kunit/configs/arch_uml.config, and then add > > CONIFG_MMU=n > > via --kconfig_add CONFIG_MMU=n. > > and then execute make ARCH=um olddefconfig, which in turn enables > CONFIG_UML_PCI_OVER_VIRTIO. > > if we append "--kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=n" to kunit.py, > it will overwrite the arch_uml.config. > > # I don't know how kunit handles those appended CONFIG entries, though.. > > my goal is simple; to test !MMU code via kunit. > my original patch or the additional kconfig argument (--kconfig_add) > satisfies this goal. > > > The problem is probably UML_PCI_OVER_VIRTIO selecting UML_PCI selecting > > various PCI code, but nothing depends on PCI in the first place. Which > > it should, then? > > I don't understand the 'nothing depends on PCI...' part. care to > elaborate ? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected] In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
