KVM: s390: protvirt: Support cmd 5 operation state

Code 5 for the set cpu state UV call tells the UV to load a PSW from
the SE header (first IPL) or from guest location 0x0 (diag 308 subcode
0/1). Also it sets the cpu into operating state afterwards, so we can
start it.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/include/asm/uv.h

@@ -169,6 +169,7 @@ struct uv_cb_unp {
 #define PV_CPU_STATE_OPR	1
 #define PV_CPU_STATE_STP	2
 #define PV_CPU_STATE_CHKSTP	3
+#define PV_CPU_STATE_OPR_LOAD	5
 
 struct uv_cb_cpu_set_state {
 	struct uv_cb_header header;

arch/s390/kvm/kvm-s390.c

@@ -3736,6 +3736,12 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 		rc = kvm_s390_vcpu_start(vcpu);
 		break;
 	case KVM_MP_STATE_LOAD:
+		if (!kvm_s390_pv_cpu_is_protected(vcpu)) {
+			rc = -ENXIO;
+			break;
+		}
+		rc = kvm_s390_pv_set_cpu_state(vcpu, PV_CPU_STATE_OPR_LOAD);
+		break;
 	case KVM_MP_STATE_CHECK_STOP:
 		/* fall through - CHECK_STOP and LOAD are not supported yet */
 	default: