[PATCH v2] target/ppc: Deprecate Power8E and Power8NVL

[Aditya Gupta <adityag@linux.ibm.com>]

Power8E and Power8NVL variants are not of much use in QEMU now, and not
being maintained either.

Newer skiboot might not be able to boot Power8NVL since skiboot v7.0

Deprecate the 8E and 8NVL variants.

After deprecation, QEMU will print a warning like below when the
CPU/Chips are used:

    $ ./build/qemu-system-ppc64 -M powernv8 --cpu power8nvl -nographic
    qemu-system-ppc64: warning: CPU model power8nvl_v1.0-powerpc64-cpu is deprecated -- CPU is unmaintained.
    ...
    $ ./build/qemu-system-ppc64 -M powernv8 --cpu power8e -nographic
    qemu-system-ppc64: warning: CPU model power8e_v2.1-powerpc64-cpu is deprecated -- CPU is unmaintained.
    ...
    $ ./build/qemu-system-ppc64 -M pseries --cpu power8e -nographic
    qemu-system-ppc64: warning: CPU model power8e_v2.1-powerpc64-cpu is deprecated -- CPU is unmaintained.
    ...

Also, print '(deprecated)' for deprecated CPUs in 'qemu-system-ppc64
--cpu ?':

    $ ./build/qemu-system-ppc64 --cpu help
      ...
      power8e_v2.1     PVR 004b0201 (deprecated)
      power8e          (alias for power8e_v2.1)
      power8nvl_v1.0   PVR 004c0100 (deprecated)
      power8nvl        (alias for power8nvl_v1.0)
      power8_v2.0      PVR 004d0200
      power8           (alias for power8_v2.0)
      power9_v2.0      PVR 004e1200
      power9_v2.2      PVR 004e1202
      ...

Suggested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>

---
Cover Letter
============

Power8E and Power8NVL are not maintained, and not useful to qemu, and
upstream skiboot also has removed support till Power8 DD1.
Power8NVL CPU doesn't boot since skiboot v7.0, or following skiboot commit
to be exact:

    commit c5424f683ee3 ("Remove support for POWER8 DD1")

No direct way to deprecate the pnv chips, a field like deprecation_note
could be added, but felt not needed as the chip will only get used if
the user requests corresponding 8E / 8NVL CPU, which will print
deprecation warning.

Also, no separate pnv machine for 8E and 8NVL, user has to pass --cpu,
which will throw the deprecation warning. So just deprecating CPUs should
be enough.

Changelog
=========
v2:
  + add mention to docs/about/deprecated.rst
  + add '(deprecated)' in output of qemu-system-ppc64 --cpu help
---
---
 docs/about/deprecated.rst |  9 +++++++++
 target/ppc/cpu-models.c   | 17 ++++++++++++++---
 target/ppc/cpu_init.c     |  7 ++++++-
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index e2b4f077d453..d6b39db2aaca 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -275,6 +275,15 @@ embedded 405 for power management (OCC) and other internal tasks, it
 is theoretically possible to use QEMU to model them. Let's keep the
 CPU implementation for a while before removing all support.
 
+Power8E and Power8NVL CPUs and corresponding Pnv chips (since 10.0)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+The Power8E and Power8NVL variants of Power8 are not really useful anymore
+in qemu, and are old and unmaintained now.
+
+The CPUs as well as corresponding Power8NVL and Power8E PnvChips will also
+be considered deprecated.
+
 System emulator machines
 ------------------------
 
diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
index ece348178188..6f2062e2c484 100644
--- a/target/ppc/cpu-models.c
+++ b/target/ppc/cpu-models.c
@@ -32,17 +32,22 @@
 /* PowerPC CPU definitions                                                 */
 #define POWERPC_DEF_PREFIX(pvr, svr, type)                                  \
     glue(glue(glue(glue(pvr, _), svr), _), type)
-#define POWERPC_DEF_SVR(_name, _desc, _pvr, _svr, _type)                    \
+#define POWERPC_DEF_SVR_DEPR(_name, _desc, _pvr, _svr, _type, _is_deprecated) \
     static void                                                             \
     glue(POWERPC_DEF_PREFIX(_pvr, _svr, _type), _cpu_class_init)            \
     (ObjectClass *oc, void *data)                                           \
     {                                                                       \
         DeviceClass *dc = DEVICE_CLASS(oc);                                 \
+        CPUClass *cc    = CPU_CLASS(oc);                                    \
         PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);                       \
                                                                             \
         pcc->pvr          = _pvr;                                           \
         pcc->svr          = _svr;                                           \
         dc->desc          = _desc;                                          \
+                                                                            \
+        if (_is_deprecated) {                                               \
+            cc->deprecation_note = "CPU is unmaintained.";                  \
+        }                                                                   \
     }                                                                       \
                                                                             \
     static const TypeInfo                                                   \
@@ -63,6 +68,12 @@
     type_init(                                                              \
         glue(POWERPC_DEF_PREFIX(_pvr, _svr, _type), _cpu_register_types))
 
+#define POWERPC_DEF_SVR(_name, _desc, _pvr, _svr, _type)                    \
+    POWERPC_DEF_SVR_DEPR(_name, _desc, _pvr, _svr, _type, false)
+
+#define POWERPC_DEPRECATED_CPU(_name, _pvr, _type, _desc)                   \
+    POWERPC_DEF_SVR_DEPR(_name, _desc, _pvr, POWERPC_SVR_NONE, _type, true)
+
 #define POWERPC_DEF(_name, _pvr, _type, _desc)                              \
     POWERPC_DEF_SVR(_name, _desc, _pvr, POWERPC_SVR_NONE, _type)
 
@@ -722,11 +733,11 @@
                 "POWER7 v2.3")
     POWERPC_DEF("power7p_v2.1",  CPU_POWERPC_POWER7P_v21,            POWER7,
                 "POWER7+ v2.1")
-    POWERPC_DEF("power8e_v2.1",  CPU_POWERPC_POWER8E_v21,            POWER8,
+    POWERPC_DEPRECATED_CPU("power8e_v2.1",  CPU_POWERPC_POWER8E_v21, POWER8,
                 "POWER8E v2.1")
     POWERPC_DEF("power8_v2.0",   CPU_POWERPC_POWER8_v20,             POWER8,
                 "POWER8 v2.0")
-    POWERPC_DEF("power8nvl_v1.0", CPU_POWERPC_POWER8NVL_v10,         POWER8,
+    POWERPC_DEPRECATED_CPU("power8nvl_v1.0", CPU_POWERPC_POWER8NVL_v10, POWER8,
                 "POWER8NVL v1.0")
     POWERPC_DEF("power9_v2.0",   CPU_POWERPC_POWER9_DD20,            POWER9,
                 "POWER9 v2.0")
diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index 7decc09aec8f..fade53f7e2d6 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -7143,6 +7143,7 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
 {
     ObjectClass *oc = data;
     PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
+    CPUClass *cc = CPU_CLASS(oc);
     DeviceClass *family = DEVICE_CLASS(ppc_cpu_get_family_class(pcc));
     const char *typename = object_class_get_name(oc);
     char *name;
@@ -7153,7 +7154,11 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
     }
 
     name = cpu_model_from_type(typename);
-    qemu_printf("  %-16s PVR %08x\n", name, pcc->pvr);
+    if (cc->deprecation_note) {
+        qemu_printf("  %-16s PVR %08x (deprecated)\n", name, pcc->pvr);
+    } else {
+        qemu_printf("  %-16s PVR %08x\n", name, pcc->pvr);
+    }
     for (i = 0; ppc_cpu_aliases[i].alias != NULL; i++) {
         PowerPCCPUAlias *alias = &ppc_cpu_aliases[i];
         ObjectClass *alias_oc = ppc_cpu_class_by_name(alias->model);
-- 
2.49.0