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

From: Shawn Guo <shawn.guo@linaro.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Maximilian Luz <luzmaximilian@gmail.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Jeffrey Hugo <jhugo@codeaurora.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	linux-efi <linux-efi@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>
Subject: Re: [PATCH] arm64: efi: add check for broken efi poweroff
Date: Wed, 19 May 2021 22:05:45 +0800	[thread overview]
Message-ID: <20210519140545.GA26772@dragon> (raw)
In-Reply-To: <CAMj1kXFY_0uqGVn7La7v=8Aocz+X5T+zN=ZOzfwHHmjRe-Jhzg@mail.gmail.com>

On Tue, May 18, 2021 at 09:44:12AM +0200, Ard Biesheuvel wrote:
> On Mon, 17 May 2021 at 02:59, Shawn Guo <shawn.guo@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@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@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.

Last time when I was seeing reboot/poweroff broken on Flex 5G, I did not
capture any kernel dumps.  I will retry with efi=debug and see if I can
get more information.

In the meantime, could you help me understand if EFI must be running in
virtual address mode when kernel is calling into the services, or it
should work no matter EFI is running in virtual or physical address
mode?  Thanks!

Shawn

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