KVM: s390: protvirt: Instruction emulation

We have two new SIE exit codes dealing with instructions.
104 (0x68) for a secure instruction interception, on which the SIE needs
hypervisor action to complete the instruction. We can piggy-back on the
existing instruction handlers.

108 which is merely a notification and provides data for tracking and
management. For example this is used to tell the host about a new value
for the prefix register. As there will be several special case handlers
in later patches, we handle this in a separate function.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/include/asm/kvm_host.h

@@ -217,6 +217,8 @@ struct kvm_s390_sie_block {
 #define ICPT_KSS	0x5c
 #define ICPT_MCHKREQ	0x60
 #define ICPT_INT_ENABLE	0x64
+#define ICPT_PV_INSTR	0x68
+#define ICPT_PV_NOTIFY	0x6c
 	__u8	icptcode;		/* 0x0050 */
 	__u8	icptstatus;		/* 0x0051 */
 	__u16	ihcpu;			/* 0x0052 */

arch/s390/kvm/intercept.c

@@ -444,6 +444,11 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
 	return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 }
 
+static int handle_pv_notification(struct kvm_vcpu *vcpu)
+{
+	return handle_instruction(vcpu);
+}
+
 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 {
 	int rc, per_rc = 0;
@@ -489,6 +494,12 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 		 */
 		rc = 0;
 		break;
+	case ICPT_PV_INSTR:
+		rc = handle_instruction(vcpu);
+		break;
+	case ICPT_PV_NOTIFY:
+		rc = handle_pv_notification(vcpu);
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}