Re: [PATCH v11 2/3] KVM: s390: guest support for topology function

[Pierre Morel]

On 7/4/22 13:02, Pierre Morel wrote:
> On 7/4/22 11:08, Janis Schoetterl-Glausch wrote:
> > On 7/1/22 18:25, Pierre Morel wrote:

...

> > > +    if (test_kvm_facility(vcpu->kvm, 11))
> > > +        vcpu->arch.sie_block->ecb |= ECB_PTF;
> > >       if (test_kvm_facility(vcpu->kvm, 73))
> > >           vcpu->arch.sie_block->ecb |= ECB_TE;
> > >       if (!kvm_is_ucontrol(vcpu->kvm))
> > > @@ -3403,6 +3437,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
> > >       rc = kvm_s390_vcpu_setup(vcpu);
> > >       if (rc)
> > >           goto out_ucontrol_uninit;
> > > +
> > > +    kvm_s390_update_topology_change_report(vcpu->kvm, 1);
> > >       return 0;
> > >   out_ucontrol_uninit:
> > > diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
> > > index 12c464c7cddf..046afee1be94 100644
> > > --- a/arch/s390/kvm/priv.c
> > > +++ b/arch/s390/kvm/priv.c
> > > @@ -873,10 +873,13 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
> > >       if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
> > >           return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
> > > -    if (fc > 3) {
> > > -        kvm_s390_set_psw_cc(vcpu, 3);
> > > -        return 0;
> > > -    }
> > > +    /* Bailout forbidden function codes */
> > > +    if (fc > 3 && (fc != 15 || kvm_s390_pv_cpu_is_protected(vcpu)))
> > > +        goto out_no_data;
> > > +
> > > +    /* fc 15 is provided with PTF/CPU topology support */
> > > +    if (fc == 15 && !test_kvm_facility(vcpu->kvm, 11))
> > > +        goto out_no_data;
> > >       if (vcpu->run->s.regs.gprs[0] & 0x0fffff00
> > >           || vcpu->run->s.regs.gprs[1] & 0xffff0000)
> > > @@ -910,6 +913,11 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
> > >               goto out_no_data;
> > >           handle_stsi_3_2_2(vcpu, (void *) mem);
> > >           break;
> > > +    case 15: /* fc 15 is fully handled in userspace */
> > > +        if (vcpu->kvm->arch.user_stsi)
> > > +            insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);
> > > +        trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
> > > +        return -EREMOTE;
> >
> > This doesn't look right to me, you still return -EREMOTE if user_stsi 
> > is false.
> > The way I read the PoP here is that it is ok to set condition code 3 
> > for the else case
>
> Yes it is what I wanted to do.
> I do not understand what I did here is stupid.

I thought again on this as I explain in another thread, I do not think 
we need to check on user_stsi here.


>

--
Pierre Morel
IBM Lab Boeblingen