Re: [PATCH 00/27] single-binary: implement dynamic filtering for machine types

On Fri, Jul 31, 2026 at 1:34 AM Pierrick Bouvier <
[email protected]> wrote:
>
> On 7/23/2026 5:09 PM, Pierrick Bouvier wrote:
> > Now that we can link a single-binary with at least two targets (arm,
aarch64),
> > we want to make sure that we expose the same set of machines (later
devices and
> > cpus) than target binaries. For that, we implemented a static filtering
based on
> > target interfaces that each machine will implement to declare which
targets have
> > this machine.
> >
> > However, we discovered that this static filtering is not enough.
Indeed, some
> > machines and devices do not depend only on target, and their presence
can depend
> > on Kconfig or host/target combination. Thus, our static approach can't
work, and
> > we need something more flexible.
> >
> > This series adds a new TYPE_TARGET_SPECIFIC, that declare a single
function
> > bool is_available(void). From there, any machine type (and later
devices and
> > cpus) can implement it to override their presence for each target.
> > We first replace the existing static mechanism with this, and once
done, we
> > cleanup all the old interface. One nice benefit is that we can get rid
of
> > config/targets/*.c files, which saves duplication.
> >
> > This series was tested by comparing list of machines for all qemu system
> > binaries, before and after this change, to make sure we don't introduce
a
> > regression.
> >

I am also tracing for this. So what's the shape of the final command line?

Maybe we can at least get arm/arm64/riscv32/risv64/riscv32-be/risv64-be to
be in a single binary.

The -be is needed because gdbstub would need this to get gdb working fine.
so the endian mode is important. arm/arm64 have nothing about be support
yet, even though in spec also have



> > Pierrick Bouvier (27):
> >   include/qemu/target-info-qom.h: declare TYPE_TARGET_SPECIFIC interface
> >   hw/arm: implement TYPE_TARGET_SPECIFIC
> >   target-info: add target_riscv32 and target_base_riscv
> >   hw/riscv: implement TYPE_TARGET_SPECIFIC
> >   target-info: add target_config_multiprocess
> >   hw/remote/machine: remove unsupported arm target
> >   hw/remote/machine: implement TYPE_TARGET_SPECIFIC
> >   target-info: add target_config_xen
> >   hw/arm/xen-pvh: implement TYPE_TARGET_SPECIFIC
> >   hw/xenpv/xen_machine_pv: implement TYPE_TARGET_SPECIFIC
> >   target-info: add target_config_nitro
> >   hw/nitro/machine: implement TYPE_TARGET_SPECIFIC
> >   target-info-qom: implement new machine filtering per target
> >   target-info-qom: use TYPE_MACHINE instead of target_machine_typename
> >   target-info: remove target_machine_typename
> >   target-info-qom: add type_target_specific
> >   hw/arm: remove TYPE_TARGET_{AARCH64,ARM}_MACHINE
> >   hw/arm: remove {arm,arm_aarch64,aarch64}_machine_interfaces
> >   include/hw/core/boards.h: add DEFINE_MACHINE_TARGET_SPECIFIC
> >   hw/arm: remove DEFINE_MACHINE_{AARCH64,ARM}
> >   hw/arm: remove machines-qom.h
> >   hw/riscv: remove TYPE_TARGET_{RISCV32,RISCV64}_MACHINE
> >   hw/riscv: remove {riscv32,riscv32_64,riscv64}_machine_interfaces
> >   hw/riscv: remove DEFINE_MACHINE_{RISCV32,RISCV64}
> >   hw/riscv: remove machines-qom.h
> >   configs/targets: remove target info definitions

> >   target-info: rename target-info-stub.c in target-info-def.c

Does that mean  target-info-def.c would be compiled N-times. N is the
target list count and finally linkage into a single binary?
How to choose this target-info?


> >
>
> Gentle ping after a week.
> You're welcome to review only your architecture if time is limited, and
> validate the global approach.
>
> Regards,
> Pierrick
>


--
         此致
礼
罗勇刚
Yours
    sincerely,
Yonggang Luo