Re: [Qemu-devel] [PATCH v2 5/7] ACPICA: Integrate package handling with module-level code

[Dan Williams]

On Mon, Apr 16, 2018 at 4:15 PM, Schmauss, Erik <address@hidden> wrote:
> [ trimming ]
>> >> Rafael, we may want to hold back on the module-level code changes
>> >> (the patches below) for rc1. Between this and the strange _TSS issue,
>> >> it seems like there are a few more things to resolve before this is
>> >> ready for kernel upstream.
>> >
> Hi Rafael,
>
>> > It looks like you are asking me to queue up reverts as per the Dan's
>> > report, is that correct?
>
> This is indeed what I meant last week. However, I've looked into the issue 
> and Dan's qemu
> instance had AML that we no longer support. This is because the ACPICA commit 
> makes changes to the execution of AML
> during table load to match windows AML interpreter behavior so this commit 
> also got rid of support for executing code
> containing forward references (except for package elements).
>
> I've suggested a fix for the firmware in a separate email. So I would say 
> that this issue is resolved after if Dan can run
> his test successfully with the adjusted firmware.
>
> If Dan's test is successful, we don’t need to revert these changes

I'm concerned about other qemu-kvm users that do not upgrade their
hypervisor at the same pace as their guest kernel. Especially for
cloud providers that may be running latest mainline kernel on older
qemu-kvm this will look like a pure kernel regression. Is there a
quick fix we can carry in the kernel to support these forward
references, at least until we know that qemu-kvm is no longer shipping
the broken AML?