Re: [edk2-devel] [PATCH v2 2/2] ArmVirtPkg/ArmVirtQemu: Avoid early ID map on ThunderX

["Ard Biesheuvel" <ardb@kernel.org>]

On Tue, 7 Feb 2023 at 11:51, Oliver Steffen <osteffen@redhat.com> wrote:
>
> On Thu, Feb 2, 2023 at 12:09 PM Oliver Steffen <osteffen@redhat.com> wrote:
>>
>>
>> On Wed, Feb 1, 2023 at 2:29 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>>>
>>> On Wed, 1 Feb 2023 at 13:59, Oliver Steffen <osteffen@redhat.com> wrote:
>>> >
>>> > On Wed, Feb 1, 2023 at 12:52 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>>> >>
>>> >> On Wed, 1 Feb 2023 at 10:14, Oliver Steffen <osteffen@redhat.com> wrote:
>>> >> >
>>
>> [...]
>>>
>>> >> > I am sorry, this story does not seem to be over yet.
>>> >> >
>>> >> > We are using the Erratum patch and also included the commit 406504c7 in
>>> >> > the kernel.
>>> >> > Now the firmware crashes sometimes (10 out of 89 tests).
>>> >> >
>>> >>
>>> >> Thanks for the report. Is this still on ThunderX2?
>>> >>
>>> >> > Any hints are very welcome!
>>> >> >
>>> >>
>>> >> Do  you have access to those build artifacts?
>>> >
>>> >
>>> > https://kojihub.stream.centos.org/kojifiles/work/tasks/5251/1835251/edk2-aarch64-20221207gitfff6d81270b5-4.el9.test.noarch.rpm
>>> >
>>> > and/or here:
>>> >
>>> > https://kojihub.stream.centos.org/koji/taskinfo?taskID=1835251
>>> >
>>> > Source for reference:
>>> > https://gitlab.com/redhat/centos-stream/src/edk2/-/merge_requests/24
>>> >
>>>
>>> Any chance the .dll files (which are actually ELF executables) have
>>> been preserved somewhere?
>>
>> Here is the build folder (~90MB):
>> https://gitlab.com/osteffen/thunderx2-debug/-/raw/main/armvirt-thunderx2-issue.tar.xz
>>
>> I am waiting for the tests with the additional debug output to run.
>
>
> We reran the test suite with the Erratum and the additional debug
> output enabled.  Strangely, the problem does not occur anymore, the
> firmware boots up normally.
>
> We retried the tests without the additional debug output.
> RHEL ships two firmware flavors for AARCH64: a silent and a verbose
> version.

Are these RELEASE vs DEBUG builds?

> Both were tried. We see no problems with the verbose
> one. The silent one fails noticeably more often if a software TPM device
> is present.
>

This smells like some missing cache or TLB maintenance - the verbose
one exits to the host much more often, and likely relies on cache/TLB
maintenance occurring in the hypervisor.

So the build always includes TPM support but the issue only occurs
when the sw TPM is actually exposed by QEMU?

> Could this be related to how much stuff is going on in the early phase
> of the firmware (when logging is enabled: formatting of messages and
> sending to serial port...) ?
>

I'll try to see if I can rig something up that logs into a buffer
rather than straight to the serial, and dump it all out when handling
the crash