Re: [PATCH v5 20/20] linux-user/s390x: Add vdso

[Richard Henderson]

On 9/4/23 08:00, Alex Bennée wrote:
> Due to the b4 dropping the vdso.so in the patch this fails:
>
>    Program build-vdso.sh found: YES 
> (/home/alex/lsrc/qemu.git/linux-user/build-vdso.sh)
>    ../../linux-user/s390x/meson.build:24:0: ERROR: File vdso.so does not exist.
>    A full log can be found at 
> /home/alex/lsrc/qemu.git/builds/all/meson-logs/meson-log.txt
>    FAILED: build.ninja
>    /home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/meson --internal regenerate 
> /home/alex/lsrc/qemu.git /home/alex/lsrc/qemu.git/builds/all
>    ninja: error: rebuilding 'build.ninja': subcommand failed
>      BUILD   aarch64-softmmu guest-tests
>    tests/tcg/aarch64-softmmu: -march=armv8.3-a detected
>
> which makes me think the dependencies are broken anyway because I have a
> working s390x compiler:
>
>    ➜  cat tests/tcg/s390x-linux-user/config-target.mak
>    # Automatically generated by configure - do not modify
>    TARGET_NAME=s390x
>    TARGET=s390x-linux-user
>    EXTRA_CFLAGS=
>    CC=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-gcc -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    CCAS=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-gcc -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    AR=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-ar -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    AS=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-as -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    LD=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-ld -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    NM=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-nm -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    OBJCOPY=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-objcopy -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git 
> --
>    RANLIB=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-ranlib -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    STRIP=/home/alex/lsrc/qemu.git/builds/all/pyvenv/bin/python3 -B 
> /home/alex/lsrc/qemu.git/tests/docker/docker.py --engine docker cc --cc 
> s390x-linux-gnu-strip -i qemu/debian-s390x-cross -s /home/alex/lsrc/qemu.git --
>    BUILD_STATIC=y
>    QEMU=/home/alex/lsrc/qemu.git/builds/all/qemu-s390x
>    HOST_GDB_SUPPORTS_ARCH=y
>
> We really need to express the dependency on
> docker-image-debian-s390x-cross (when using containers) to ensure we can
> build the vdso.so and not rely on the copy we have.

I think expressing the dependency is a mistake.

The major problem is network unreliability.  I installed a new vm to build test this, and 
it took more than a dozen retrys to get all of the docker images built.

What we do right now is determine if docker or podman is present and works, and then 
*assume* we can make all of the cross-compilers work later, and so register them as 
cross-compilers early.

I think the only moderately reliable thing is to determine what containers are already 
present and working and use only those.  Developers will need to manually rebuild 
containers periodically and then re-run configure to make those visible to the cross-build 
machinery.  Not completely ideal, of course, but nothing else is either.


r~