On Mon, 07 Nov 2016 19:34:42 +1100 Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote: > Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: > > On 04/11/2016 06:48, Michael Ellerman wrote: > >> diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig > >> index da6e2ce77495..6b51a4ebed8a 100644 > >> --- a/drivers/vfio/Kconfig > >> +++ b/drivers/vfio/Kconfig > >> @@ -6,12 +6,12 @@ config VFIO_IOMMU_TYPE1 > >> config VFIO_IOMMU_SPAPR_TCE > >> tristate > >> depends on VFIO && SPAPR_TCE_IOMMU > >> - default n > >> + default VFIO > > > > No need to depend on VFIO since you already have it in "default". depends and defaults are different beasts though, if VFIO is not enabled and we're not on a powerpc system with SPAPR, VFIO_IOMMU_SPAPR_TCE should not be selectable, not just default to 'n'. > > True, I can take that out. > > > (I assume you cannot use "default y" because "depends on" doesn't downgrade > > "y" to "m" when VFIO is a module. > > Correct. > > > A shorthand is > > > > def_tristate VFIO && SPAPR_TCE_IOMMU > > Yep. My experience though is that a lot of folks don't really know what > that means. So I prefer to spell it out with an explicit type, depends > and default. > > But I'll respin it that way if Alex prefers the shorter style. Perhaps I'm one of those people. Non-powerpc archs should not have an option to select this, which is why the depends is there, AIUI. So long as we don't start exposing options that aren't relevant to a platform, I'm flexible on what shorthands we use, but you may need to teach me about them first. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
