Re: [Qemu-devel] [PATCH v2 1/2] s390x/tcg: wire up pci instructions

[Cornelia Huck <cohuck@redhat.com>]

On Thu, 1 Feb 2018 13:42:52 +0100
David Hildenbrand <david@redhat.com> wrote:

> On 31.01.2018 19:17, Cornelia Huck wrote:

> > +#ifndef CONFIG_USER_ONLY
> > +void HELPER(clp)(CPUS390XState *env, uint32_t r2)
> > +{
> > +    S390CPU *cpu = s390_env_get_cpu(env);
> > +    int r;
> > +
> > +    qemu_mutex_lock_iothread();
> > +    r = clp_service_call(cpu, r2, GETPC());
> > +    qemu_mutex_unlock_iothread();
> > +    if (r) {
> > +        s390_program_interrupt(env, PGM_OPERATION, 4, GETPC());
> > +    }  
> 
> We don't need the if (r) ... so I suggest dropping all these. (as I
> said, will be handled later via the generic flag checking in translation
> code). We can ignore any error from these functions.

I did not check the instruction implementations in detail... was the
error really only for the !CONFIG_PCI case?

(I really should know that...)

> A sane guest will newer trigger this. (if we have no CONFIG_PCI, the
> also the ZPCI feature will not be available)

Hopefully we can also handle non-sane guests correctly...

> 
> Makes the code even shorter :)
>