Re: gdb support for SME-without-SVE ?

[Thiago Jung Bauermann via Gdb <gdb@sourceware.org>]

Peter Maydell <peter.maydell@linaro.org> writes:

> On Fri, 30 Jan 2026 at 17:06, Thiago Jung Bauermann
> <thiago.bauermann@linaro.org> wrote:
>> Peter Maydell <peter.maydell@linaro.org> writes:
>> > Is there something I can rm in my build directory that will delete
>> > all the testsuite stuff and force it to recreate it ? (I would
>> > prefer not to have to blow away the whole build directory and
>> > spend hours waiting for gdb to be rebuilt...)
>>
>> You can try deleting these under $GDB_BUILD_DIR:
>>
>> gdb/testsuite/site.exp
>> gdb/testsuite/cache
>> gdb/testsuite/outputs
>>
>> In the worst case, you could delete the whole gdb/ directory. You'll
>> have to rebuild all the gdb files, but at least not bfd, gdbserver,
>> gdbsupport etc.
>
> I tried removing all of gdb/testsuite/ and then putting back
> the files that 'make' complained were missing (config.status
> and Makefile). That seemed to do the trick at least as far
> as being able to run the tests now.

Great!

> With my updated QEMU
> (which you can find in the new "sme-no-sve-2" in my gitlab repo)
> that can now run the tests without making the kernel fall over.
> It reports:
>
> # of expected passes            241
> # of unexpected failures        37
>
> Is that the same as you see on the fast model, or does this
> indicate that I still have more QEMU bugs to track down?
> (Peeking into gdb.log, these failures seem to be run-on
> failures from the program under test getting a SIGILL
> in initialize_zt_state(), so my guess is QEMU is still not
> quite right.)

Indeed, there seems to be something off with QEMU.
On FVP, all the tests pass:

                === gdb Summary ===

# of expected passes            278

-- 
Thiago