Re: [PATCH 1/3] target/arm: Use CONFIG_SEMIHOSTING instead of TCG for semihosting

[Peter Maydell]

On Thu, 4 May 2023 at 08:33, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 5/3/23 21:38, Fabiano Rosas wrote:
> > When building --without-default-devices, the semihosting code will not
> > be available, so check the proper config.

I think the changes to the ifdeffery are conceptually
fine (only do semihosting if it was configured in), but
it sounds like there's a separate problem here.
Whether we need semihosting depends on the accelerator (ie
"is it TCG or not"), not on what set of devices we're building.
So the problem seems to me to be that --without-default-devices
is causing the semihosting code not to be built in.

> Acked-by: Paolo Bonzini <pbonzini@redhat.com>
>
> for this change; however, there are two more related issues:
>
> 1) you still want to leave out the code if !TCG, because KVM is not able
> to exit to userspace on semihosting calls as far as I understand
>
> 2) I am not sure why CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y appears in
> config/targets/{arm,riscv32,riscv64}-softmmu/default.mak.

Because those are the architectures which have
"arm-compatible" semihosting ABIs ?

-- PMM