KVM: s390: protvirt: handle secure guest prefix pages

The SPX instruction is handled by the ultravisor. We do get a
notification intercept, though. Let us update our internal view.

In addition to that, when the guest prefix page is not secure, an
intercept 112 (0x70) is indicated. Let us make the prefix pages
secure again.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@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

@@ -225,6 +225,7 @@ struct kvm_s390_sie_block {
 #define ICPT_INT_ENABLE	0x64
 #define ICPT_PV_INSTR	0x68
 #define ICPT_PV_NOTIFY	0x6c
+#define ICPT_PV_PREF	0x70
 	__u8	icptcode;		/* 0x0050 */
 	__u8	icptstatus;		/* 0x0051 */
 	__u16	ihcpu;			/* 0x0052 */

arch/s390/kvm/intercept.c

@@ -451,6 +451,15 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
 	return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 }
 
+static int handle_pv_spx(struct kvm_vcpu *vcpu)
+{
+	u32 pref = *(u32 *)vcpu->arch.sie_block->sidad;
+
+	kvm_s390_set_prefix(vcpu, pref);
+	trace_kvm_s390_handle_prefix(vcpu, 1, pref);
+	return 0;
+}
+
 static int handle_pv_sclp(struct kvm_vcpu *vcpu)
 {
 	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
@@ -477,6 +486,8 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu)
 
 static int handle_pv_notification(struct kvm_vcpu *vcpu)
 {
+	if (vcpu->arch.sie_block->ipa == 0xb210)
+		return handle_pv_spx(vcpu);
 	if (vcpu->arch.sie_block->ipa == 0xb220)
 		return handle_pv_sclp(vcpu);
 
@@ -534,6 +545,13 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 	case ICPT_PV_NOTIFY:
 		rc = handle_pv_notification(vcpu);
 		break;
+	case ICPT_PV_PREF:
+		rc = 0;
+		gmap_convert_to_secure(vcpu->arch.gmap,
+				       kvm_s390_get_prefix(vcpu));
+		gmap_convert_to_secure(vcpu->arch.gmap,
+				       kvm_s390_get_prefix(vcpu) + PAGE_SIZE);
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}