KVM: s390: Support keyless subset guest mode
If the KSS facility is available on the machine, we also make it
available for our KVM guests.
The KSS facility bypasses storage key management as long as the guest
does not issue a related instruction. When that happens, the control is
returned to the host, which has to turn off KSS for a guest vcpu
before retrying the instruction.
Signed-off-by: Corey S. McQuay <csmcquay@linux.vnet.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 2c9ad25..bf92679 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -119,6 +119,7 @@ struct kvm_s390_vm_cpu_machine {
#define KVM_S390_VM_CPU_FEAT_CMMA 10
#define KVM_S390_VM_CPU_FEAT_PFMFI 11
#define KVM_S390_VM_CPU_FEAT_SIGPIF 12
+#define KVM_S390_VM_CPU_FEAT_KSS 13
struct kvm_s390_vm_cpu_feat {
__u64 feat[16];
};