[PATCH] arm64: efi: add check for broken efi poweroff

[Ard Biesheuvel]

On Mon, 17 May 2021 at 02:59, Shawn Guo <shawn.guo at linaro.org> wrote:
>
> + Maximilian
>
> On Fri, Mar 05, 2021 at 08:01:02AM +0100, Ard Biesheuvel wrote:
> > On Fri, 5 Mar 2021 at 07:51, Shawn Guo <shawn.guo at linaro.org> wrote:
> > >
> > > Poweroff via UEFI Runtime Services doesn't always work on every single
> > > arm64 machine.  For example, on Lenovo Flex 5G laptop, it results in
> > > a system reboot rather than shutdown.  Add a DMI check to keep such
> > > system stay with the original poweroff method (PSCI).
> > >
> > > Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
> >
> > What is the point of using EFI runtime services on this machine if
> > poweroff doesn't work either? Can't we just boot this thing with
> > efi=noruntime?
>
> Ard,
>
> With Maximilian playing ACPI kernel on Microsoft Surface Pro X, this
> ResetSystem service issue triggers more discussion and testing [1].
> Maximilian tested it with uefi-test-runner and reported that ResetSystem
> actually works [2].
>
> Looking at the kernel dump, I'm wondering if it's because that kernel
> calls into the services with assuming they are in virtual addressing
> mode, while actually they are in flat physical mode instead, due to
> that SetVirtualAddressMap() call is skipped (efi_novamap).
>

That looks like a firmware bug. Boot with efi=debug to figure out
whether the faulting address is a physical address that falls inside a
EfiRuntimeServicesData region.