Re: 'make check-tcg' fails with an assert in qemu_plugin_vcpu_init_hook

[Peter Maydell]

On Tue, 20 Jun 2023 at 17:56, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> $ make -C build/x86 check-tcg
> make: Entering directory 
> '/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/x86'
> [...]
>   TEST    munmap-pthread on arm
> **
> ERROR:../../plugins/core.c:221:qemu_plugin_vcpu_init_hook: assertion
> failed: (success)
> **
> ERROR:../../accel/tcg/cpu-exec.c:1024:cpu_exec_setjmp: assertion
> failed: (cpu == current_cpu)

git bisect blames commit d7ee93e2435970:

    cputlb: Restrict SavedIOTLB to system emulation

I think that commit is not correct, because it means that
the size of 'struct CPUState' and also the offset of fields
like 'cpu_index' will be different for files which are
compile-per-target-for-usermode and files which are
compile-once-only. The assert happens here because the
code which sets up cpu_index is build-once, but the code
in qemu_plugin_vcpu_init_hook() which reads cpu_index is
build-per-target and now they don't agree about where in
the struct the field is...

Reverting the commit fixes the bug.

thanks
-- PMM