Re: [PATCH] binfmt: Don't consider riscv{32, 64} part of the same family

[Alistair Francis]

On Fri, Jan 3, 2025 at 2:04 AM Andrea Bolognani <abologna@redhat.com> wrote:
>
> On Tue, Dec 03, 2024 at 10:47:02AM +0100, Andrea Bolognani wrote:
> > Currently the script won't generate a configuration file that
> > sets up qemu-user-riscv32 on riscv64, likely under the
> > assumption that 64-bit RISC-V machines can natively run 32-bit
> > RISC-V code.
> >
> > However this functionality, while theoretically possible, in
> > practice is missing from most commonly available RISC-V hardware
> > and not enabled at the distro level. So qemu-user-riscv32 really
> > is the only option to run riscv32 binaries on riscv64.
> >
> > Make riscv32 and riscv64 each its own family, so that the
> > configuration file we need to make 32-on-64 userspace emulation
> > work gets generated.
> >
> > Link: https://src.fedoraproject.org/rpms/qemu/pull-request/72
> > Thanks: David Abdurachmanov <davidlt@rivosinc.com>
> > Thanks: Daniel P. Berrangé <berrange@redhat.com>
> > Signed-off-by: Andrea Bolognani <abologna@redhat.com>
> > ---
> >  scripts/qemu-binfmt-conf.sh | 7 ++-----
> >  1 file changed, 2 insertions(+), 5 deletions(-)
>
> ping
>
> There are already two ACKs so I think we just need a maintainer to
> pick this up.

We didn't get an answer to the issue of a CPU supporting RV32 and yet
the kernel still calls QEMU.

I understand this allows things to work out of the box, but seems like
a disservice to any hardware that does support RV32

Alistair

>
> --
> Andrea Bolognani / Red Hat / Virtualization
>
>