On 09/27/2015 12:06 AM, Ingo Molnar wrote: > > * Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > >>> If we allocate the EFI runtime as a single virtual memory block then issues >>> like rounding between sections does not even come up as a problem: we map the >>> original offsets and sizes byte by byte. >> >> Well, by that reasoning, we should not call SetVirtualAddressMap() in the first >> place, and just use the 1:1 mapping UEFI uses natively. This is more than >> feasible on arm64, and I actually fought hard against using >> SetVirtualAddressMap() at all, but I was overruled by others. I think this is >> also trivially possible on X64, since the 1:1 mapping is already active >> alongside the VA mapping. > > 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. > Pro: by far the sanest way to map the UEFI tables. Con: doesn't actually work (breaks on several known platforms.) -hpa -- 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
