On 02/28/2018 10:48 AM, David Hildenbrand wrote: > On 27.02.2018 15:28, 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 the >> AP facilities are installed on the KVM guest. This >> feature will be enabled by the kernel only if the AP >> facilities are installed on the linux host. This feature >> must be specifically turned on for the KVM guest from >> userspace to allow guest access to AP devices installed >> on the linux host. >> >> 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. >> >> 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. >> >> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> >> Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxxxxxxx> >> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> >> --- >> arch/s390/include/uapi/asm/kvm.h | 1 + >> arch/s390/kvm/kvm-s390.c | 4 ++++ >> arch/s390/tools/gen_facilities.c | 2 ++ >> 3 files changed, 7 insertions(+), 0 deletions(-) >> >> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >> index 4cdaa55..a580dec 100644 >> --- a/arch/s390/include/uapi/asm/kvm.h >> +++ b/arch/s390/include/uapi/asm/kvm.h >> @@ -130,6 +130,7 @@ struct kvm_s390_vm_cpu_machine { >> #define KVM_S390_VM_CPU_FEAT_PFMFI 11 >> #define KVM_S390_VM_CPU_FEAT_SIGPIF 12 >> #define KVM_S390_VM_CPU_FEAT_KSS 13 >> +#define KVM_S390_VM_CPU_FEAT_AP 14 >> struct kvm_s390_vm_cpu_feat { >> __u64 feat[16]; >> }; >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index de1e299..c68ca86 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -347,6 +347,10 @@ static void kvm_s390_cpu_feat_init(void) >> >> if (MACHINE_HAS_ESOP) >> allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP); >> + >> + if (ap_instructions_installed()) /* AP instructions installed on host */ >> + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP); > > Don't we have a SIE specific AP feature? So is it true, that once we > have AP instructions, we are allowed to use them for SIE? Isn't there a > "AP interpretation facility" or anything like that? (that unlocks ECA_APIE) This seems to be coupled to the AP facility and there is no facility or scp bit. AP is too old to have that (predates STFLE) -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html