While we have removed csske and bpb from the default model, the very
common case of "host-model" in libvirt (expanded to a base model
+ features) would still contain bpb and csske. This can prevent
migration to a future machine for a host-model machine. Let us fence
bpb and csske when we run on a generation 15. If necessary the
user can still use -cpu 8561,csske=on,bpb=on to force enable these
features.
Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com>
---
target/s390x/cpu_models.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index e727519686..03bdca1fb8 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -629,6 +629,17 @@ CpuModelExpansionInfo
*qmp_query_cpu_model_expansion(CpuModelExpansionType type,
return NULL;
}
+ /*
+ * Do not claim CSSKE and BPB if the host model expands to
+ * generation 15 or newer
+ */
+ if (s390_model.def->gen >= 15) {
+ clear_bit(S390_FEAT_CONDITIONAL_SSKE,
+ (unsigned long *) &s390_model.features);
+ clear_bit(S390_FEAT_BPB,
+ (unsigned long *) &s390_model.features);
+ }
+
if (type == CPU_MODEL_EXPANSION_TYPE_STATIC) {
delta_changes = true;
} else if (type != CPU_MODEL_EXPANSION_TYPE_FULL) {
--
2.19.1
