On Mon, 5 Jun 2023 at 21:23, Richard Henderson <richard.hender...@linaro.org> wrote: > > If CONFIG_USER_ONLY is ok generically, so is CONFIG_SOFTMMU, > because they are exactly opposite.
This isn't quite right. CONFIG_USER_ONLY is theoretically something we should poison, because it's unsafe in the general case to use it in compiled-once source files. But in practice we make quite a lot of use of it in "we know this specific use of it is OK" situations, like ifdeffing out function prototypes. So we'd like to poison it, but we can't poison it without a huge amoun of refactoring which isn't really worth the effort. So it's not a good model for "therefore it's OK not to poison CONFIG_SOFTMMU" -- we should leave that poisoned if we can, so we don't introduce either new buggy uses of CONFIG_SOFTMMU, or new "we know this is safe" uses of it which will make it difficult to put it back into the poison-list later... thanks -- PMM
