Re: [kvm-unit-tests RFC PATCH 1/6] powerpc: add pmu tests

[Chinmay Rath <rathc@linux.ibm.com>]

On 6/8/26 19:27, Thomas Huth wrote:
> On 08/06/2026 14.45, Thomas Huth wrote:
>> On 02/06/2026 08.48, Chinmay Rath wrote:
>>> From: Nicholas Piggin <npiggin@gmail.com>
>>>
>>> Add some initial PMU testing.
>>>
>>> - PMC5/6 tests
>>> - PMAE / PMI test
>>> - BHRB basic tests
>>>
>>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>>> Signed-off-by: Chinmay Rath <rathc@linux.ibm.com>
>>> ---
>>>   lib/powerpc/asm/processor.h |   2 +
>>>   lib/powerpc/asm/reg.h       |   9 +
>>>   lib/powerpc/asm/setup.h     |   1 +
>>>   lib/powerpc/setup.c         |  20 ++
>>>   powerpc/Makefile.common     |   3 +-
>>>   powerpc/pmu.c               | 567 
>>> ++++++++++++++++++++++++++++++++++++
>>>   powerpc/unittests.cfg       |   3 +
>>>   7 files changed, 604 insertions(+), 1 deletion(-)
>>>   create mode 100644 powerpc/pmu.c
>>
>>   Hi Chinmay,
>>
>> the problem with Clang on Travis [*] still seems to persist:
>>
>>   https://app.travis-ci.com/github/huth/kvm-unit-tests/jobs/639614142
>>
>> Could you please have a look?
>>
>>   Thanks,
>>    Thomas
>>
>>
>> [*] This already happened with Nicolas' last version:
>>
>>   https://www.spinics.net/lists/kvm/msg351218.html
>
> I managed to get access to a ppc64 machine. The error is:
>
> /tmp/pmu-eab466.s: Assembler messages:
> /tmp/pmu-eab466.s:1649: Error: unrecognized opcode: `ldat'
> clang: error: assembler command failed with exit code 1 (use -v to see 
> invocation)
> make: *** [<builtin>: powerpc/pmu.o] Error 1
>
>  HTH,
>   Thomas
Hi Thomas,

Thanks for looking into this and providing the exact error message.

I was looking into this Travis CI job that you pointed to and noticed 
that the clang version being used was 14.
I was wondering, would it be possible to use a newer version of clang 
for the job since LDAT is a legit PPC insn,
that was introduced with Power 9, ISA version 3.0, way back a decade in 
2016 !
So I was wondering if using a newer version of clang that recognizes the 
instruction would be a better approach.

I checked the .travis.yml file (config) for the job, which mentions :
|apt_packages: clang qemu-system-ppc|

Can we change it to something like :
|apt_packages: clang19 qemu-system-ppc |or (clang-19)  ?

In the same config s390x uses a specific version of clang that is 11 in 
similar manner.

However if you'd still prefer working around LDAT, I could try with 
LDARX instead, but I am unable to verify if
clang-14 will recognize that since the oldest version of clang I could 
find in ppc64le repo was clang-15 which
was able to work with LDAT as well. Hence, could you help me with 
providing the steps to use Travis-CI so I could verify ?
(I had skipped doing the credit card payment while signing up, in case 
that's mandatory for Travis CI. Pardon me I'm new to it XD)

Thanks,
Chinmay