Let's use the KVM_SET_DEVICE_ATTR ioctl to enable hardware
interpretation of AP instructions executed on the guest.
If the S390_FEAT_AP feature is switched on for the guest,
AP instructions must 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: NTony Krowiak <akrowiak@linux.ibm.com>
Tested-by: NPierre Morel <pmorel@linux.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NHalil Pasic <pasic@linux.ibm.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20181010170309.12045-4-akrowiak@linux.ibm.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>