Re: s390x/qemu-user: TODO /home/dhildenb/git/qemu/tcg/tci.c:859: tcg_qemu_tb_exec()

[Philippe Mathieu-Daudé]

On 10/17/19 12:35 PM, David Hildenbrand wrote:
> On 17.10.19 12:25, Philippe Mathieu-Daudé wrote:
> > Hi David,
> >
> > On 10/17/19 12:02 PM, David Hildenbrand wrote:
> > > Hi,
> > >
> > > I'm currently trying to run Fedora 31 under qemu-user
> > > (https://github.com/fedora-cloud/docker-brew-fedora/tree/8a81f67271e959dfc8f8a888b161bbd540b7a83b/s390x) 
> > >
> > > in order to debug  a vector instruction issue.
> > >
> > > Strangely, when trying to chroot into above rootfs and running
> > > /bin/bash, I get
> > >
> > > t460s: ~/f31  $ sudo chroot . ./qemu-s390x  /bin/bash
> > > TODO /home/dhildenb/git/qemu/tcg/tci.c:859: tcg_qemu_tb_exec()
> > > /home/dhildenb/git/qemu/tcg/tci.c:859: tcg fatal error
> > > Aborted
> > >
> > >
> > > But it's not fundamentally broken:
> > >
> > > t460s: ~/f31  $ sudo chroot . ./qemu-s390x  /bin/ls
> > > bin   dev  home  lib64       media  opt   qemu-s390x  run   srv  tmp  
> > > var
> > > boot  etc  lib   lost+found  mnt    proc  root        sbin  sys  usr
> > >
> > >
> > > I do wonder why we don't run into the same issue under qemu-systems390x.
> >
> > Are you also using TCI in system emulation?
>
> Most probably not. It took me longer than expected to find a ./configure 
> variant that at least allows me to build static qemu-user binaries. Most 
> probably something sneeked in there.
>
> > Can you simply use TCG to debug your vector instruction issue instead?
>
> I was using
>
> ./configure --disable-strip --disable-werror --python=/usr/bin/python3 
> --enable-tcg-interpreter --disable-system --enable-linux-user --static 
> --disable-pie --disable-sdl --disable-gtk --disable-spice 
> --disable-tools --disable-guest-agent --disable-guest-agent-msi 
> --disable-curses --disable-curl --disable-gnutls --disable-gcrypt 
> --disable-nettle --disable-cap-ng --disable-brlapi --disable-mpath 
> --disable-capstone --disable-xen --disable-rdma 
> --extra-ldflags="-Wl,-z,relro -Wl,-z,now" --target-list=s390x-linux-user
>
> inspired by the Fedora rpm SPEC.
>
> "--enable-tcg-interpreter" is the relevant bit I blindly copied without 
> thinking about it (in the rpm SPEC, it is wrapped by an ifdef ...)

I thought there was a patch adding a big warning when ./configure is run 
with this option, but I can't find it so maybe we just talked about it.

> Thanks for the hint, will try with --disable-tcg-interpreter
>
> > Regards,
> >
> > Phil.