Re: [PATCH v6 05/21] KVM: s390: CPU model support for AP virtualization

[Tony Krowiak]

On 07/02/2018 11:41 AM, Cornelia Huck wrote:
> On Mon, 2 Jul 2018 11:37:11 -0400
> Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
>
> > On 07/02/2018 10:38 AM, Christian Borntraeger wrote:
> > > On 06/29/2018 11:11 PM, Tony Krowiak wrote:
> > > > Introduces a new CPU model feature and two CPU model
> > > > facilities to support AP virtualization for KVM guests.
> > > >
> > > > CPU model feature:
> > > >
> > > > The KVM_S390_VM_CPU_FEAT_AP feature indicates that
> > > > AP instructions are available on the guest. This
> > > > feature will be enabled by the kernel only if the AP
> > > > instructions are installed on the linux host. This feature
> > > > must be specifically turned on for the KVM guest from
> > > > userspace to use the VFIO AP device driver for guest
> > > > access to AP devices.
> > > >
> > > > CPU model facilities:
> > > >
> > > > 1. AP Query Configuration Information (QCI) facility is installed.
> > > >
> > > >      This is indicated by setting facilities bit 12 for
> > > >      the guest. The kernel will not enable this facility
> > > >      for the guest if it is not set on the host. This facility
> > > >      must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP
> > > >      feature is not installed.
> > > >
> > > >      If this facility is not set for the KVM guest, then only
> > > >      APQNs with an APQI less than 16 will be available to the
> > > >      guest regardless of the guest's matrix configuration. This
> > > >      is a limitation of the AP bus running on the guest.
> > > >
> > > > 2. AP Facilities Test facility (APFT) is installed.
> > > >
> > > >      This is indicated by setting facilities bit 15 for
> > > >      the guest. The kernel will not enable this facility for
> > > >      the guest if it is not set on the host. This facility
> > > >      must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP
> > > >      feature is not installed.
> > > >
> > > >      If this facility is not set for the KVM guest, then no
> > > >      AP devices will be available to the guest regardless of
> > > >      the guest's matrix configuration. This is a limitation
> > > >      of the AP bus running under the guest.
> > > >
> > > > Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> > > > Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
> > > > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> > > I think it probably should be at the end of the series, other than that its good.
> > If I move this to the end of the series, the very next patch checks the
> >
> > KVM_S390_VM_CPU_FEAT_AP feature?
> Introduce it here, offer it only with the last patch?

I apologize, but I don't know what you mean by this. Are you suggesting 
this patch
should only include the #define for KVM_S390_VM_CPU_FEAT_AP?

>