KVM: s390: VCPU_EVENT cleanup for prefix changes

SPX (SET PREFIX)  and SIGP (Set prefix) can change the prefix
register of a CPU. As sigp set prefix may be handled in user
space (KVM_CAP_S390_USER_SIGP), we would not log the changes
triggered via SIGP in that case. Let's have just one VCPU_EVENT
at the central location that tracks prefix changes.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>

arch/s390/kvm/interrupt.c

@@ -427,7 +427,6 @@ static int __must_check __deliver_set_prefix(struct kvm_vcpu *vcpu)
 	clear_bit(IRQ_PEND_SET_PREFIX, &li->pending_irqs);
 	spin_unlock(&li->lock);
 
-	VCPU_EVENT(vcpu, 4, "interrupt: set prefix to %x", prefix.address);
 	vcpu->stat.deliver_prefix_signal++;
 	trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id,
 					 KVM_S390_SIGP_SET_PREFIX,

arch/s390/kvm/kvm-s390.h

@@ -65,6 +65,8 @@ static inline u32 kvm_s390_get_prefix(struct kvm_vcpu *vcpu)
 
 static inline void kvm_s390_set_prefix(struct kvm_vcpu *vcpu, u32 prefix)
 {
+	VCPU_EVENT(vcpu, 3, "set prefix of cpu %03u to 0x%x", vcpu->vcpu_id,
+		   prefix);
 	vcpu->arch.sie_block->prefix = prefix >> GUEST_PREFIX_SHIFT;
 	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 	kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu);

arch/s390/kvm/priv.c

@@ -98,8 +98,6 @@ static int handle_set_prefix(struct kvm_vcpu *vcpu)
 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 
 	kvm_s390_set_prefix(vcpu, address);
-
-	VCPU_EVENT(vcpu, 5, "setting prefix to %x", address);
 	trace_kvm_s390_handle_prefix(vcpu, 1, address);
 	return 0;
 }

arch/s390/kvm/sigp.c

@@ -205,9 +205,6 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 		*reg &= 0xffffffff00000000UL;
 		*reg |= SIGP_STATUS_INCORRECT_STATE;
 		return SIGP_CC_STATUS_STORED;
-	} else if (rc == 0) {
-		VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x",
-			   dst_vcpu->vcpu_id, irq.u.prefix.address);
 	}
 
 	return rc;