Re: [PATCH v3 2/9] s390: ap: kvm: setting a hook for PQAP instructions

[Pierre Morel]

On 15/02/2019 10:26, Cornelia Huck wrote:
> On Thu, 14 Feb 2019 17:45:06 +0100
> Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
>
> > On 14/02/2019 16:54, Cornelia Huck wrote:
> > > On Thu, 14 Feb 2019 14:51:02 +0100
> > > Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
> > >    
> > > > This patch adds interception code for the PQAP instructions,
> > > > and a callback inside the KVM arch structure for s390.
> > > >
> > > > If a VFIO-AP drivers needs to intercept PQAP/AQIC or PQAP/TAPQ
> > >
> > > s/drivers/driver/
> >
> > thanks. OK
>
> > > > + *
> > > > + * This callback only handles PQAP/AQIC instruction and
> > >
> > > Here you only talk about PQAP/AQIC, what about PQAP/TAPQ mentioned in
> > > the patch description?
> >
> > I can add "for now" or "in this patch" or suppress the reference to
> > PAPQ/TAPQ
>
> I'd just add a note to the patch description that this patch only
> handles PQAP/AQCI and that handling PQAP/TAPQ is something for a
> follow-on patch.

OK, I will clear this.
Thanks


> > >   

...snip...

> > > > +	/* PQAP instructions are allowed for guest kernel only */
> > > > +	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
> > > > +		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
> > > > +	/* AQIC instruction is allowed only if facility 65 is available */
> > > > +	if (!test_kvm_facility(vcpu->kvm, 65))
> > > > +		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
> > > > +	/* All right, call the callback */
> > > > +	return vcpu->kvm->arch.crypto.pqap_hook(vcpu);
> > >
> > > Can that callback also return -EOPNOTSUPP to order to drop to user
> > > space?
> >
> > Yes.
> > Why not?
>
> Maybe also mention that in the function description?

Will do thanks.

Regards,
Pierre

--
Pierre Morel
Linux/KVM/QEMU in BÃblingen - Germany