[PATCH v6 0/2] Deprecate Power8E and Power8NVL

[PATCH v6 0/2] Deprecate Power8E and Power8NVL

[Aditya Gupta]

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
=========
v6:
  + change qemu version from 10.0 to 10.1 in doc
v5 (https://lore.kernel.org/qemu-devel/20250422043843.26115-1-adityag@linux.ibm.com/):
  + split into 2 patches, defining macro, and deprecating 8e & 8nvl
v4 (https://lore.kernel.org/qemu-devel/20250330211012.2932258-1-adityag@linux.ibm.com/):
  + remove unnecessary 'if'
v3:
  + add 'deprecation_note' argument to the POWERPC_DEPRECATED_CPU macro
v2:
  + add mention to docs/about/deprecated.rst
  + add '(deprecated)' in output of qemu-system-ppc64 --cpu help

Base Commit: a9cd5bc6399a80fcf233ed0fffe6067b731227d8

Aditya Gupta (2):
  target/ppc: Introduce macro for deprecating PowerPC CPUs
  target/ppc: Deprecate Power8E and Power8NVL

 docs/about/deprecated.rst |  9 +++++++++
 target/ppc/cpu-models.c   | 20 +++++++++++++++-----
 target/ppc/cpu_init.c     |  7 ++++++-
 3 files changed, 30 insertions(+), 6 deletions(-)

-- 
2.49.0

[PATCH v6 1/2] target/ppc: Introduce macro for deprecating PowerPC CPUs

[Aditya Gupta]

QEMU has a way to deprecate CPUs by setting the 'deprecation_note' in
CPUClass.

Currently PowerPC CPUs don't use this deprecation process.

Introduce 'POWERPC_DEPRECATED_CPU' macro to deprecate particular PowerPC
CPUs in future.

With the change, QEMU will print a warning like below when the
deprecated CPU/Chips are used (example output if power8nvl is deprecated):

    $ ./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.
    ...

Also, print '(deprecated)' for deprecated CPUs in 'qemu-system-ppc64
--cpu ?' (example output if power8nvl is deprecated):

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

Suggested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
---
 target/ppc/cpu-models.c | 12 +++++++++++-
 target/ppc/cpu_init.c   |  7 ++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/target/ppc/cpu-models.c b/target/ppc/cpu-models.c
index ece348178188..78ef23b4c4b8 100644
--- a/target/ppc/cpu-models.c
+++ b/target/ppc/cpu-models.c
@@ -32,17 +32,20 @@
 /* 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, _deprecation_note) \
     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;                                          \
+                                                                            \
+        cc->deprecation_note = _deprecation_note;                           \
     }                                                                       \
                                                                             \
     static const TypeInfo                                                   \
@@ -63,6 +66,13 @@
     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, NULL)
+
+#define POWERPC_DEPRECATED_CPU(_name, _pvr, _type, _desc, _deprecation_note)\
+    POWERPC_DEF_SVR_DEPR(_name, _desc, _pvr, POWERPC_SVR_NONE, _type,       \
+            _deprecation_note)
+
 #define POWERPC_DEF(_name, _pvr, _type, _desc)                              \
     POWERPC_DEF_SVR(_name, _desc, _pvr, POWERPC_SVR_NONE, _type)
 
diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index f81cb680fc38..78a25637ad4f 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -7144,6 +7144,7 @@ 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;
@@ -7154,7 +7155,11 @@ 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

[PATCH v6 2/2] target/ppc: Deprecate Power8E and Power8NVL

[Aditya Gupta]

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

Power8NVL CPU doesn't boot since skiboot v7.0, or following skiboot commit
to be exact:

    commit c5424f683ee3 ("Remove support for POWER8 DD1")

Deprecate the 8E and 8NVL variants.

Suggested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
---
 docs/about/deprecated.rst | 9 +++++++++
 target/ppc/cpu-models.c   | 8 ++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 05381441a9ff..966f2e634028 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 10.1)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+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 78ef23b4c4b8..cc79a6373d63 100644
--- a/target/ppc/cpu-models.c
+++ b/target/ppc/cpu-models.c
@@ -732,12 +732,12 @@
                 "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,
-                "POWER8E v2.1")
+    POWERPC_DEPRECATED_CPU("power8e_v2.1",  CPU_POWERPC_POWER8E_v21, POWER8,
+                "POWER8E v2.1", "CPU is unmaintained.")
     POWERPC_DEF("power8_v2.0",   CPU_POWERPC_POWER8_v20,             POWER8,
                 "POWER8 v2.0")
-    POWERPC_DEF("power8nvl_v1.0", CPU_POWERPC_POWER8NVL_v10,         POWER8,
-                "POWER8NVL v1.0")
+    POWERPC_DEPRECATED_CPU("power8nvl_v1.0", CPU_POWERPC_POWER8NVL_v10, POWER8,
+                "POWER8NVL v1.0", "CPU is unmaintained.")
     POWERPC_DEF("power9_v2.0",   CPU_POWERPC_POWER9_DD20,            POWER9,
                 "POWER9 v2.0")
     POWERPC_DEF("power9_v2.2",   CPU_POWERPC_POWER9_DD22,            POWER9,
-- 
2.49.0

Re: [PATCH v6 2/2] target/ppc: Deprecate Power8E and Power8NVL

[Cédric Le Goater]

On 4/22/25 08:00, Aditya Gupta wrote:
> Power8E and Power8NVL variants are not of much use in QEMU now, and not
> being maintained either.
> 
> Power8NVL CPU doesn't boot since skiboot v7.0, or following skiboot commit
> to be exact:
> 
>      commit c5424f683ee3 ("Remove support for POWER8 DD1")
> 
> Deprecate the 8E and 8NVL variants.
> 
> Suggested-by: Cédric Le Goater <clg@kaod.org>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   docs/about/deprecated.rst | 9 +++++++++
>   target/ppc/cpu-models.c   | 8 ++++----
>   2 files changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
> index 05381441a9ff..966f2e634028 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 10.1)
> +'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
> +
> +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 78ef23b4c4b8..cc79a6373d63 100644
> --- a/target/ppc/cpu-models.c
> +++ b/target/ppc/cpu-models.c
> @@ -732,12 +732,12 @@
>                   "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,
> -                "POWER8E v2.1")
> +    POWERPC_DEPRECATED_CPU("power8e_v2.1",  CPU_POWERPC_POWER8E_v21, POWER8,
> +                "POWER8E v2.1", "CPU is unmaintained.")
>       POWERPC_DEF("power8_v2.0",   CPU_POWERPC_POWER8_v20,             POWER8,
>                   "POWER8 v2.0")
> -    POWERPC_DEF("power8nvl_v1.0", CPU_POWERPC_POWER8NVL_v10,         POWER8,
> -                "POWER8NVL v1.0")
> +    POWERPC_DEPRECATED_CPU("power8nvl_v1.0", CPU_POWERPC_POWER8NVL_v10, POWER8,
> +                "POWER8NVL v1.0", "CPU is unmaintained.")
>       POWERPC_DEF("power9_v2.0",   CPU_POWERPC_POWER9_DD20,            POWER9,
>                   "POWER9 v2.0")
>       POWERPC_DEF("power9_v2.2",   CPU_POWERPC_POWER9_DD22,            POWER9,