KVM: s390: trace and count all skey intercepts

Let's trace and count all skey handling operations, even if lazy skey
handling was already activated. Also, don't enable lazy skey handling if
anything went wrong while enabling skey handling for the SIE.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kvm/priv.c

@@ -152,24 +152,27 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
 static int __skey_check_enable(struct kvm_vcpu *vcpu)
 {
 	int rc = 0;
+
+	trace_kvm_s390_skey_related_inst(vcpu);
 	if (!(vcpu->arch.sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)))
 		return rc;
 
 	rc = s390_enable_skey();
-	VCPU_EVENT(vcpu, 3, "%s", "enabling storage keys for guest");
-	trace_kvm_s390_skey_related_inst(vcpu);
-	vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE);
+	VCPU_EVENT(vcpu, 3, "enabling storage keys for guest: %d", rc);
+	if (!rc)
+		vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE);
 	return rc;
 }
 
 
 static int handle_skey(struct kvm_vcpu *vcpu)
 {
-	int rc = __skey_check_enable(vcpu);
+	int rc;
 
+	vcpu->stat.instruction_storage_key++;
+	rc = __skey_check_enable(vcpu);
 	if (rc)
 		return rc;
-	vcpu->stat.instruction_storage_key++;
 
 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

arch/s390/kvm/trace.h

@@ -41,7 +41,7 @@ TRACE_EVENT(kvm_s390_skey_related_inst,
 	    TP_fast_assign(
 		    VCPU_ASSIGN_COMMON
 		    ),
-	    VCPU_TP_PRINTK("%s", "first instruction related to skeys on vcpu")
+	    VCPU_TP_PRINTK("%s", "storage key related instruction")
 	);
 
 TRACE_EVENT(kvm_s390_major_guest_pfault,