KVM: s390: pfmf: take care of amode when setting reg2

Depending on the addressing mode, we must not overwrite bit 0-31 of the
register. In addition, 24 bit and 31 bit have to set certain bits to 0,
which is guaranteed by converting the end address to an effective
address.

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

arch/s390/kvm/priv.c

@@ -733,8 +733,15 @@ static int handle_pfmf(struct kvm_vcpu *vcpu)
 
 		start += PAGE_SIZE;
 	}
-	if (vcpu->run->s.regs.gprs[reg1] & PFMF_FSC)
-		vcpu->run->s.regs.gprs[reg2] = end;
+	if (vcpu->run->s.regs.gprs[reg1] & PFMF_FSC) {
+		if (psw_bits(vcpu->arch.sie_block->gpsw).eaba == PSW_AMODE_64BIT) {
+			vcpu->run->s.regs.gprs[reg2] = end;
+		} else {
+			vcpu->run->s.regs.gprs[reg2] &= ~0xffffffffUL;
+			end = kvm_s390_logical_to_effective(vcpu, end);
+			vcpu->run->s.regs.gprs[reg2] |= end;
+		}
+	}
 	return 0;
 }