[PATCH v11 16/16] s390x: Add unpack facility feature to GA1

[Janosch Frank <frankja@linux.ibm.com>]

From: Christian Borntraeger <borntraeger@de.ibm.com>

The unpack facility is an indication that diagnose 308 subcodes 8-10
are available to the guest. That means, that the guest can put itself
into protected mode.

Once it is in protected mode, the hardware stops any attempt of VM
introspection by the hypervisor.

Some features are currently not supported in protected mode:
     * vfio devices
     * Migration
     * Huge page backings

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 target/s390x/gen-features.c | 1 +
 target/s390x/kvm.c          | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index 6278845b12b8dee8..8ddeebc54419a3e2 100644
--- a/target/s390x/gen-features.c
+++ b/target/s390x/gen-features.c
@@ -562,6 +562,7 @@ static uint16_t full_GEN15_GA1[] = {
     S390_FEAT_GROUP_MSA_EXT_9,
     S390_FEAT_GROUP_MSA_EXT_9_PCKMO,
     S390_FEAT_ETOKEN,
+    S390_FEAT_UNPACK,
 };
 
 /* Default features (in order of release)
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 6b7819d2c51a111c..3630c15f45a48864 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -2410,6 +2410,14 @@ void kvm_s390_get_host_cpu_model(S390CPUModel *model, Error **errp)
         clear_bit(S390_FEAT_BPB, model->features);
     }
 
+    /*
+     * If we have support for protected virtualization, indicate
+     * the protected virtualization IPL unpack facility.
+     */
+    if (cap_protected) {
+        set_bit(S390_FEAT_UNPACK, model->features);
+    }
+
     /* We emulate a zPCI bus and AEN, therefore we don't need HW support */
     set_bit(S390_FEAT_ZPCI, model->features);
     set_bit(S390_FEAT_ADAPTER_EVENT_NOTIFICATION, model->features);
-- 
2.25.1