KVM: s390: protvirt: STSI handling

Save response to sidad and disable address checking for protected
guests.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kvm/priv.c

@@ -2,7 +2,7 @@
 /*
  * handling privileged instructions
  *
- * Copyright IBM Corp. 2008, 2018
+ * Copyright IBM Corp. 2008, 2020
  *
  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  *               Christian Borntraeger <borntraeger@de.ibm.com>
@@ -872,7 +872,7 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 
 	operand2 = kvm_s390_get_base_disp_s(vcpu, &ar);
 
-	if (operand2 & 0xfff)
+	if (!kvm_s390_pv_cpu_is_protected(vcpu) && (operand2 & 0xfff))
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
 	switch (fc) {
@@ -893,8 +893,13 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 		handle_stsi_3_2_2(vcpu, (void *) mem);
 		break;
 	}
-
-	rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
+	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+		memcpy((void *)sida_origin(vcpu->arch.sie_block), (void *)mem,
+		       PAGE_SIZE);
+		rc = 0;
+	} else {
+		rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
+	}
 	if (rc) {
 		rc = kvm_s390_inject_prog_cond(vcpu, rc);
 		goto out;