On 11.09.23 22:52, Collin Walling wrote:
Patch subject is wrong (should contain "static-recommended")
Newer S390 machines may drop support for features completely, rendering
guests operating with older CPU models incapable of running on said
machines. A manual effort to disable certain CPU features would be
required.
To alleviate this issue, a list of "deprecated" features are now
retained within QEMU, and a new "static-recommended" CPU model expansion
type has been created to allow a query of the host-model with deprecated
features explicitly disabled.
Signed-off-by: Collin Walling <wall...@linux.ibm.com>
---
qapi/machine-target.json | 8 +++++++-
target/s390x/cpu_features.c | 14 ++++++++++++++
target/s390x/cpu_features.h | 1 +
target/s390x/cpu_models_sysemu.c | 26 +++++++++++++++++++++-----
4 files changed, 43 insertions(+), 6 deletions(-)
diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index f0a6b72414..4dc891809d 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -42,6 +42,12 @@
# to be migration-safe, but allows tooling to get an insight and
# work with model details.
#
+# @static-recommended: Expand to a static CPU model with property
+# changes suggested by the architecture. This is useful for
+# expanding a CPU model expected to operate in mixed
+# CPU-generation environments. The @static-recommended CPU
+# models are migration-safe.
+#
Can we instead make this a new parameter for query-cpu-model-expansion
("no-deprecated-features" ? ), that properly gets rejected from other
archs when not supported?
[...]
/* convert S390CPUDef into a static CpuModelInfo */
static void cpu_info_from_model(CpuModelInfo *info, const S390CPUModel *model,
- bool delta_changes)
+ bool delta_changes, bool disable_dep_feats)
"dep" can be misleading ("depended")
"no_deprecated_feat" ?
--
Cheers,
David / dhildenb
