* Borislav Petkov <bp@xxxxxxxxx> wrote: > On Sun, Sep 27, 2015 at 09:06:44AM +0200, Ingo Molnar wrote: > > > Could we please re-list all the arguments pro and contra of 1:1 physical > > mappings, in a post that also explains the background so that more people can > > chime in, not just people versed in EFI internals? It's very much possible > > that a bad decision was made. > > The main reason why we did the additional, top-down mapping was kexec kernel > wanting to use UEFI runtime facilities too and the braindead design of > SetVirtualAddressMap() being callable only once per system boot. So we had to > have stable mappings which are valid in the kexec-ed kernel too. > > But this was long time ago and I most certainly have forgotten all the details. > > And now I'm wondering why didn't we do the 1:1 thing and rebuild the exact same > EFI pagetable in the kexec-ed kernel? Because when we do an EFI call, we switch > to the special pagetable so why didn't we make the kexec-ed kernel rebuild the > 1:1 pagetable which it can use for EFI calls... Yeah. > Hmm, again, I've forgotten a lot of details so I'm sure Matt will come in and > say "No, you can't do that because..." Would be nice to re-examine all this. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
