Re: [Qemu-devel] [PATCH v4 04/54] target/arm: remove run time semihosting checks

[Richard Henderson]

On 7/31/19 9:06 AM, Alex Bennée wrote:
> -static inline bool check_for_semihosting(CPUState *cs)
> +/*
> + * Do semihosting call and set the appropriate return value. All the
> + * permission and validity checks have been done at translate time.
> + *
> + * We only see semihosting exceptions in TCG only as they are not
> + * trapped to the hypervisor in KVM.
> + */
> +static void handle_semihosting(CPUState *cs)
>  {
>  #ifdef CONFIG_TCG

Let's move the ifdef outside the function...

> -    if (check_for_semihosting(cs)) {
> +    if (cs->exception_index == EXCP_SEMIHOST) {
> +        handle_semihosting(cs);
>          return;
>      }

... and put another one here.

Peter described how we can't get EXCP_SEMIHOST here from kvm, and suggested an
assert.  Well, the assert is already present just below:

    assert(!excp_is_internal(cs->exception_index));

All we need to do is not return early beforehand.


r~