riscv glibc testing

[Palmer Dabbelt]

On Fri, 11 Nov 2022 11:51:21 PST (-0800), philipp.tomsich@vrull.eu wrote:
> Vineet,
>
> We run all testing using qemu userland through binfmt_misc by
> replacing the system-installed qemu with our own (containing the
> latest extensions).
> This supports even the strangest cases (such as fork + exec that
> alternates host and target binaries): e.g., even the test-workload of
> perlbench_r is no problem.

THat's OK for the GCC and binutils test suites, but last I checked 
QEMU's user-mode emulation couldn't handle the glibc test suite and 
wasn't accepted as a target for saying "this patch passes the tests".  
It's kind of a bummer because it makes running the glibc test suite 
without real hardware a lot more of a headache, but I think it's just 
the nature of the beast here: the glibc test suite exercises a lot of 
edge case behavior in the Linux uABI, trying to get that all matched 
perfectly in QEMU would be a lot of work (and IIUC come with some 
performance issues).

I don't think any of that has changed, but it's not really a 
RISC-V-specific problem so one of the global maintainers would know for 
sure.  I know DJ's been doing a lot of work on the patchwork testing 
stuff, so it's entirely possible something's changed?

> Philipp.
>
>
> On Fri, 11 Nov 2022 at 20:48, Vineet Gupta <vineetg@rivosinc.com> wrote:
>>
>> Hi,
>>
>> Trying to understand how folks working on riscv glibc run the testsuite.
>>
>> One could run native on Unmatched (but doesn't allow testing new
>> extensions) or native on qemu with linux (but that will likely be too
>> slow) specially the building part.
>>
>> My preferred solution would be to avoid linux altogether, do a host
>> cross-build and test with User mode qemu. And then wire it into
>> riscv-gnu-toolchain [1] just like it currently tests gcc dejagnu.
>> However glibc cross testing from my prior ARC work required linux+ssh etc.
>>
>> This email is to see if someone has such as setup already.
>>
>> Thx,
>> -Vineet
>>
>> [1] https://github.com/riscv-collab/riscv-gnu-toolchain