Am 17.09.18 um 10:19 schrieb David Hildenbrand: > Am 12.09.18 um 22:08 schrieb Tony Krowiak: >> A new CPU model feature and two new CPU model facilities are >> introduced to support AP devices for a KVM guest. >> >> CPU model features: >> >> 1. The KVM_S390_VM_CPU_FEAT_AP CPU model feature indicates that >> AP facilities are installed. This feature will be enabled by >> the kernel only if the AP facilities are installed on the linux >> host. This feature must be turned on from userspace to access >> AP devices from the KVM guest. The QEMU command line to turn >> this feature looks something like this: >> >> qemu-system-s390x ... -cpu xxx,ap=on >> >> This feature will be supported for zEC12 and newer CPU models. >> The feature will not be supported for older models due to >> testability issues. > > I think we (me, Halil and Pierre) agreed that this should not be a > CPU_FEAT but instead some AP_INTERPRETATION toggle, that can be turned > on/off dynamically. (CPU_FEAT cannot be changed after CPUs have been > created). > > Can you discuss that with Halil + Pierre? > >
Just found patch #2, I don't see a reason for KVM_S390_VM_CPU_FEAT_AP anymore. You can simply sense KVM_S390_VM_CRYPTO_ENABLE_APIE and use it to indicate the AP cpu feature. -- Thanks, David / dhildenb
