Re: [Qemu-devel] [PATCH v1 01/30] target-sparc: ignore MMU-faults if MMU is disabled in hypervisor mode

[Richard Henderson]

On 11/04/2016 02:50 PM, Artyom Tarasenko wrote:
> +    if (is_exec) { /* XXX has_hypervisor */
> +        if (env->lsu & (IMMU_E)) {
> +            cpu_raise_exception_ra(env, TT_CODE_ACCESS, GETPC());
> +        } else if (cpu_has_hypervisor(env) && !(env->hpstate & HS_PRIV)) {
> +            cpu_raise_exception_ra(env, TT_INSN_REAL_TRANSLATION_MISS, 
> GETPC());
> +        }
> +    } else {
> +        if (env->lsu & (DMMU_E)) {
> +            cpu_raise_exception_ra(env, TT_DATA_ACCESS, GETPC());
> +        } else if (cpu_has_hypervisor(env) && !(env->hpstate & HS_PRIV)) {
> +            cpu_raise_exception_ra(env, TT_DATA_REAL_TRANSLATION_MISS, 
> GETPC());
> +        }
> +    }

And if the hypervisor itself has a bug and references bad memory?  Or does the 
hypervisor *have* to do such things in order to probe for device on startup, 
and should therefore not trap.

I'm actually assuming this is the case based on the fact that you wrote this 
patch in the first place.  But if so, we need a comment here.


r~