Re: [qemu-s390x] [PATCH v8 3/6] s390x/kvm: enable/disable AP instruction interpretation for guest

[Tony Krowiak]

On 09/13/2018 01:28 AM, Thomas Huth wrote:
> On 2018-09-12 22:08, Tony Krowiak wrote:
> > From: Tony Krowiak <address@hidden>
> >
> > Let's use the KVM_SET_DEVICE_ATTR ioctl to enable or disable
> > hardware interpretation of AP instructions executed on the guest.
> > If the S390_FEAT_AP feature is installed, AP instructions will
> > be interpreted by default; otherwise, they will be intercepted.
> > This attribute setting may be overridden by a device. For example,
> > a device may want to provide AP instructions to the guest (i.e.,
> > S390_FEAT_AP turned on), but it may want to emulate them. In this
> > case, the AP instructions executed on the guest must be
> > intercepted; so when the device is realized, it must disable
> > interpretation.
> >
> > Signed-off-by: Tony Krowiak <address@hidden>
> > ---
> >   target/s390x/kvm.c |   16 ++++++++++++++++
> >   1 files changed, 16 insertions(+), 0 deletions(-)
> >
> > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> > index c4bd84d..28a3900 100644
> > --- a/target/s390x/kvm.c
> > +++ b/target/s390x/kvm.c
> > @@ -2297,6 +2297,19 @@ void kvm_s390_get_host_cpu_model(S390CPUModel *model, 
> > Error **errp)
> >                  S390_FEAT_MAX);
> >   }
> >   
> > +static void kvm_s390_configure_apie(int interpret)
> In case you respin, maybe use "bool interpret" instead of "int interpret"?
>
>   Thomas

Will do

> > +{
> > +    uint64_t attr = KVM_S390_VM_CRYPTO_DISABLE_APIE;
> > +
> > +    if (interpret) {
> > +        attr = KVM_S390_VM_CRYPTO_ENABLE_APIE;
> > +    }
> > +
> > +    if (kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO, attr)) {
> > +            kvm_s390_set_attr(attr);
> > +    }
> > +}
> > +
> >   void kvm_s390_apply_cpu_model(const S390CPUModel *model, Error **errp)
> >   {
> >       struct kvm_s390_vm_cpu_processor prop  = {
> > @@ -2346,6 +2359,9 @@ void kvm_s390_apply_cpu_model(const S390CPUModel *model, 
> > Error **errp)
> >       if (test_bit(S390_FEAT_CMM, model->features)) {
> >           kvm_s390_enable_cmma();
> >       }
> > +
> > +    /* configure hardware interpretation of AP instructions */
> > +    kvm_s390_configure_apie(test_bit(S390_FEAT_AP, model->features));
> >   }
> >   
> >   void kvm_s390_restart_interrupt(S390CPU *cpu)