[RFC PATCH] arm64/efi: use stable virtual mappings for UEFI runtime services

[Ard Biesheuvel]

On 14 October 2014 18:53, Geoff Levand <geoff.levand at linaro.org> wrote:
> Hi Ard,
>
> On Tue, 2014-10-14 at 12:26 +0200, Ard Biesheuvel wrote:
>> On 14 October 2014 04:17, Dave Young <dyoung at redhat.com> wrote:
>> > On 10/13/14 at 03:52pm, Geoff Levand wrote:
>> >> early_memremap() returns 0xFFFFFFBFFBCBF618, and the dereference
>> >> starts the crash.  I did not look into it further.
>> >
>> > This is an expected behaviour as I mentioned before, we need save fw_vendor
>> > and the other two physical addresses and pass them to 2nd kernel.
>> >
>> > UEFI firmware will convert them to virtual address after entering virtual mode.
>> >
>>
>>  Yes, you did point that out before, and I haven't addressed it in my patch.
>>
>> But allow me to emphasize *again* that these issues will simply cease
>> to exist if we decide to not use SetVirtualAddressMap() at all, and
>> call the UEFI Runtime Services through their physical mappings.
>
> Once you figure out what you will do, and you think you have a complete
> working solution, let me know and I will test them.  I don't plan to do
> any more UEFI testing until then.
>

I agree it makes sense that we align on and implement a complete
approach before spending any more of your time on this.

Thanks for testing,
Ard.