[PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Thomas Huth]

Old CPU models are not officially supported anymore by IBM, and for
downstream builds of QEMU, we would like to be able to disable these
CPUs in the build. Thus add a CONFIG switch that can be used to
disable these CPUs (and old machine types that use them by default).

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 If you're interested, the PDF that can be downloaded from
 https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
 shows the supported CPUs in a nice diagram

 hw/s390x/s390-virtio-ccw.c | 9 +++++++++
 target/s390x/cpu_models.c  | 3 +++
 target/s390x/Kconfig       | 5 +++++
 3 files changed, 17 insertions(+)

diff --git a/target/s390x/Kconfig b/target/s390x/Kconfig
index d886be48b4..8a95f2bc3f 100644
--- a/target/s390x/Kconfig
+++ b/target/s390x/Kconfig
@@ -2,3 +2,8 @@ config S390X
     bool
     select PCI
     select S390_FLIC
+
+config S390X_LEGACY_CPUS
+    bool
+    default y
+    depends on S390X
diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index efb508cd2e..ffae95dcb3 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -22,6 +22,7 @@
 #include "qemu/module.h"
 #include "qemu/hw-version.h"
 #include "qemu/qemu-print.h"
+#include CONFIG_DEVICES
 #ifndef CONFIG_USER_ONLY
 #include "sysemu/sysemu.h"
 #include "target/s390x/kvm/pv.h"
@@ -47,6 +48,7 @@
  * generation 15 one base feature and one optional feature have been deprecated.
  */
 static S390CPUDef s390_cpu_defs[] = {
+#ifdef CONFIG_S390X_LEGACY_CPUS
     CPUDEF_INIT(0x2064, 7, 1, 38, 0x00000000U, "z900", "IBM zSeries 900 GA1"),
     CPUDEF_INIT(0x2064, 7, 2, 38, 0x00000000U, "z900.2", "IBM zSeries 900 GA2"),
     CPUDEF_INIT(0x2064, 7, 3, 38, 0x00000000U, "z900.3", "IBM zSeries 900 GA3"),
@@ -78,6 +80,7 @@ static S390CPUDef s390_cpu_defs[] = {
     CPUDEF_INIT(0x2964, 13, 1, 47, 0x08000000U, "z13", "IBM z13 GA1"),
     CPUDEF_INIT(0x2964, 13, 2, 47, 0x08000000U, "z13.2", "IBM z13 GA2"),
     CPUDEF_INIT(0x2965, 13, 2, 47, 0x08000000U, "z13s", "IBM z13s GA1"),
+#endif
     CPUDEF_INIT(0x3906, 14, 1, 47, 0x08000000U, "z14", "IBM z14 GA1"),
     CPUDEF_INIT(0x3906, 14, 2, 47, 0x08000000U, "z14.2", "IBM z14 GA2"),
     CPUDEF_INIT(0x3907, 14, 1, 47, 0x08000000U, "z14ZR1", "IBM z14 Model ZR1 GA1"),
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 3d0bc3e7f2..7529d2fba8 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -47,6 +47,7 @@
 #include "migration/blocker.h"
 #include "qapi/visitor.h"
 #include "hw/s390x/cpu-topology.h"
+#include CONFIG_DEVICES
 
 static Error *pv_mig_blocker;
 
@@ -603,6 +604,8 @@ static void s390_nmi(NMIState *n, int cpu_index, Error **errp)
     s390_cpu_restart(S390_CPU(cs));
 }
 
+#ifdef CONFIG_S390X_LEGACY_CPUS
+
 static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
 {
     /* same logic as in sclp.c */
@@ -623,6 +626,8 @@ static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
     return newsz;
 }
 
+#endif
+
 static inline bool machine_get_aes_key_wrap(Object *obj, Error **errp)
 {
     S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
@@ -989,6 +994,8 @@ static void ccw_machine_6_1_class_options(MachineClass *mc)
 }
 DEFINE_CCW_MACHINE(6_1, "6.1", false);
 
+#ifdef CONFIG_S390X_LEGACY_CPUS
+
 static void ccw_machine_6_0_instance_options(MachineState *machine)
 {
     static const S390FeatInit qemu_cpu_feat = { S390_FEAT_LIST_QEMU_V6_0 };
@@ -1272,6 +1279,8 @@ static void ccw_machine_2_4_class_options(MachineClass *mc)
 }
 DEFINE_CCW_MACHINE(2_4, "2.4", false);
 
+#endif
+
 static void ccw_machine_register_types(void)
 {
     type_register_static(&ccw_machine_info);
-- 
2.45.2

Re: [PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Philippe Mathieu-Daudé]

Hi Thomas,

On 13/6/24 19:07, Thomas Huth wrote:
> Old CPU models are not officially supported anymore by IBM, and for
> downstream builds of QEMU, we would like to be able to disable these
> CPUs in the build. Thus add a CONFIG switch that can be used to
> disable these CPUs (and old machine types that use them by default).
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   If you're interested, the PDF that can be downloaded from
>   https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
>   shows the supported CPUs in a nice diagram

I'd add this link ...

>   hw/s390x/s390-virtio-ccw.c | 9 +++++++++
>   target/s390x/cpu_models.c  | 3 +++
>   target/s390x/Kconfig       | 5 +++++
>   3 files changed, 17 insertions(+)
> 
> diff --git a/target/s390x/Kconfig b/target/s390x/Kconfig
> index d886be48b4..8a95f2bc3f 100644
> --- a/target/s390x/Kconfig
> +++ b/target/s390x/Kconfig
> @@ -2,3 +2,8 @@ config S390X
>       bool
>       select PCI
>       select S390_FLIC
> +
> +config S390X_LEGACY_CPUS
> +    bool
> +    default y
> +    depends on S390X
> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
> index efb508cd2e..ffae95dcb3 100644
> --- a/target/s390x/cpu_models.c
> +++ b/target/s390x/cpu_models.c
> @@ -22,6 +22,7 @@
>   #include "qemu/module.h"
>   #include "qemu/hw-version.h"
>   #include "qemu/qemu-print.h"
> +#include CONFIG_DEVICES
>   #ifndef CONFIG_USER_ONLY
>   #include "sysemu/sysemu.h"
>   #include "target/s390x/kvm/pv.h"
> @@ -47,6 +48,7 @@
>    * generation 15 one base feature and one optional feature have been deprecated.
>    */
>   static S390CPUDef s390_cpu_defs[] = {
> +#ifdef CONFIG_S390X_LEGACY_CPUS

... here :)

>       CPUDEF_INIT(0x2064, 7, 1, 38, 0x00000000U, "z900", "IBM zSeries 900 GA1"),
>       CPUDEF_INIT(0x2064, 7, 2, 38, 0x00000000U, "z900.2", "IBM zSeries 900 GA2"),
>       CPUDEF_INIT(0x2064, 7, 3, 38, 0x00000000U, "z900.3", "IBM zSeries 900 GA3"),
> @@ -78,6 +80,7 @@ static S390CPUDef s390_cpu_defs[] = {
>       CPUDEF_INIT(0x2964, 13, 1, 47, 0x08000000U, "z13", "IBM z13 GA1"),
>       CPUDEF_INIT(0x2964, 13, 2, 47, 0x08000000U, "z13.2", "IBM z13 GA2"),
>       CPUDEF_INIT(0x2965, 13, 2, 47, 0x08000000U, "z13s", "IBM z13s GA1"),
> +#endif
>       CPUDEF_INIT(0x3906, 14, 1, 47, 0x08000000U, "z14", "IBM z14 GA1"),
>       CPUDEF_INIT(0x3906, 14, 2, 47, 0x08000000U, "z14.2", "IBM z14 GA2"),
>       CPUDEF_INIT(0x3907, 14, 1, 47, 0x08000000U, "z14ZR1", "IBM z14 Model ZR1 GA1"),
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 3d0bc3e7f2..7529d2fba8 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -47,6 +47,7 @@
>   #include "migration/blocker.h"
>   #include "qapi/visitor.h"
>   #include "hw/s390x/cpu-topology.h"
> +#include CONFIG_DEVICES
>   
>   static Error *pv_mig_blocker;
>   
> @@ -603,6 +604,8 @@ static void s390_nmi(NMIState *n, int cpu_index, Error **errp)
>       s390_cpu_restart(S390_CPU(cs));
>   }
>   
> +#ifdef CONFIG_S390X_LEGACY_CPUS
> +
>   static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
>   {
>       /* same logic as in sclp.c */
> @@ -623,6 +626,8 @@ static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
>       return newsz;
>   }
>   
> +#endif
> +
>   static inline bool machine_get_aes_key_wrap(Object *obj, Error **errp)
>   {
>       S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
> @@ -989,6 +994,8 @@ static void ccw_machine_6_1_class_options(MachineClass *mc)
>   }
>   DEFINE_CCW_MACHINE(6_1, "6.1", false);
>   
> +#ifdef CONFIG_S390X_LEGACY_CPUS
> +
>   static void ccw_machine_6_0_instance_options(MachineState *machine)
>   {
>       static const S390FeatInit qemu_cpu_feat = { S390_FEAT_LIST_QEMU_V6_0 };

Should we deprecate machines up to v6.0?

> @@ -1272,6 +1279,8 @@ static void ccw_machine_2_4_class_options(MachineClass *mc)
>   }
>   DEFINE_CCW_MACHINE(2_4, "2.4", false);
>   
> +#endif
> +
>   static void ccw_machine_register_types(void)
>   {
>       type_register_static(&ccw_machine_info);

Re: [PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Thomas Huth]

On 13/06/2024 19.17, Philippe Mathieu-Daudé wrote:
> Hi Thomas,
> 
> On 13/6/24 19:07, Thomas Huth wrote:
>> Old CPU models are not officially supported anymore by IBM, and for
>> downstream builds of QEMU, we would like to be able to disable these
>> CPUs in the build. Thus add a CONFIG switch that can be used to
>> disable these CPUs (and old machine types that use them by default).
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
>>   If you're interested, the PDF that can be downloaded from
>>   https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
>>   shows the supported CPUs in a nice diagram
> 
> I'd add this link ...
> 
>>   hw/s390x/s390-virtio-ccw.c | 9 +++++++++
>>   target/s390x/cpu_models.c  | 3 +++
>>   target/s390x/Kconfig       | 5 +++++
>>   3 files changed, 17 insertions(+)
>>
>> diff --git a/target/s390x/Kconfig b/target/s390x/Kconfig
>> index d886be48b4..8a95f2bc3f 100644
>> --- a/target/s390x/Kconfig
>> +++ b/target/s390x/Kconfig
>> @@ -2,3 +2,8 @@ config S390X
>>       bool
>>       select PCI
>>       select S390_FLIC
>> +
>> +config S390X_LEGACY_CPUS
>> +    bool
>> +    default y
>> +    depends on S390X
>> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
>> index efb508cd2e..ffae95dcb3 100644
>> --- a/target/s390x/cpu_models.c
>> +++ b/target/s390x/cpu_models.c
>> @@ -22,6 +22,7 @@
>>   #include "qemu/module.h"
>>   #include "qemu/hw-version.h"
>>   #include "qemu/qemu-print.h"
>> +#include CONFIG_DEVICES
>>   #ifndef CONFIG_USER_ONLY
>>   #include "sysemu/sysemu.h"
>>   #include "target/s390x/kvm/pv.h"
>> @@ -47,6 +48,7 @@
>>    * generation 15 one base feature and one optional feature have been 
>> deprecated.
>>    */
>>   static S390CPUDef s390_cpu_defs[] = {
>> +#ifdef CONFIG_S390X_LEGACY_CPUS
> 
> ... here :)

Can do ... let's just hope that the link is stable in the course of time!

>>       CPUDEF_INIT(0x2064, 7, 1, 38, 0x00000000U, "z900", "IBM zSeries 900 
>> GA1"),
>>       CPUDEF_INIT(0x2064, 7, 2, 38, 0x00000000U, "z900.2", "IBM zSeries 
>> 900 GA2"),
>>       CPUDEF_INIT(0x2064, 7, 3, 38, 0x00000000U, "z900.3", "IBM zSeries 
>> 900 GA3"),
>> @@ -78,6 +80,7 @@ static S390CPUDef s390_cpu_defs[] = {
>>       CPUDEF_INIT(0x2964, 13, 1, 47, 0x08000000U, "z13", "IBM z13 GA1"),
>>       CPUDEF_INIT(0x2964, 13, 2, 47, 0x08000000U, "z13.2", "IBM z13 GA2"),
>>       CPUDEF_INIT(0x2965, 13, 2, 47, 0x08000000U, "z13s", "IBM z13s GA1"),
>> +#endif
>>       CPUDEF_INIT(0x3906, 14, 1, 47, 0x08000000U, "z14", "IBM z14 GA1"),
>>       CPUDEF_INIT(0x3906, 14, 2, 47, 0x08000000U, "z14.2", "IBM z14 GA2"),
>>       CPUDEF_INIT(0x3907, 14, 1, 47, 0x08000000U, "z14ZR1", "IBM z14 Model 
>> ZR1 GA1"),
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 3d0bc3e7f2..7529d2fba8 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -47,6 +47,7 @@
>>   #include "migration/blocker.h"
>>   #include "qapi/visitor.h"
>>   #include "hw/s390x/cpu-topology.h"
>> +#include CONFIG_DEVICES
>>   static Error *pv_mig_blocker;
>> @@ -603,6 +604,8 @@ static void s390_nmi(NMIState *n, int cpu_index, Error 
>> **errp)
>>       s390_cpu_restart(S390_CPU(cs));
>>   }
>> +#ifdef CONFIG_S390X_LEGACY_CPUS
>> +
>>   static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
>>   {
>>       /* same logic as in sclp.c */
>> @@ -623,6 +626,8 @@ static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
>>       return newsz;
>>   }
>> +#endif
>> +
>>   static inline bool machine_get_aes_key_wrap(Object *obj, Error **errp)
>>   {
>>       S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
>> @@ -989,6 +994,8 @@ static void ccw_machine_6_1_class_options(MachineClass 
>> *mc)
>>   }
>>   DEFINE_CCW_MACHINE(6_1, "6.1", false);
>> +#ifdef CONFIG_S390X_LEGACY_CPUS
>> +
>>   static void ccw_machine_6_0_instance_options(MachineState *machine)
>>   {
>>       static const S390FeatInit qemu_cpu_feat = { S390_FEAT_LIST_QEMU_V6_0 };
> 
> Should we deprecate machines up to v6.0?

I'm still hoping that Daniel will be able to get his auto-deprecation 
patches merged in this cycle - then we shouldn't derive from that, I think.

By the way, what's up with your i440fx removal series? ... it would be good 
to get this finally merged now...?

  Thomas

Re: [PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Philippe Mathieu-Daudé]

On 13/6/24 19:22, Thomas Huth wrote:
> On 13/06/2024 19.17, Philippe Mathieu-Daudé wrote:
>> Hi Thomas,
>>
>> On 13/6/24 19:07, Thomas Huth wrote:
>>> Old CPU models are not officially supported anymore by IBM, and for
>>> downstream builds of QEMU, we would like to be able to disable these
>>> CPUs in the build. Thus add a CONFIG switch that can be used to
>>> disable these CPUs (and old machine types that use them by default).
>>>
>>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>>> ---
>>>   If you're interested, the PDF that can be downloaded from
>>>   https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
>>>   shows the supported CPUs in a nice diagram
>>
>> I'd add this link ...
>>
>>>   hw/s390x/s390-virtio-ccw.c | 9 +++++++++
>>>   target/s390x/cpu_models.c  | 3 +++
>>>   target/s390x/Kconfig       | 5 +++++
>>>   3 files changed, 17 insertions(+)
>>>
>>> diff --git a/target/s390x/Kconfig b/target/s390x/Kconfig
>>> index d886be48b4..8a95f2bc3f 100644
>>> --- a/target/s390x/Kconfig
>>> +++ b/target/s390x/Kconfig
>>> @@ -2,3 +2,8 @@ config S390X
>>>       bool
>>>       select PCI
>>>       select S390_FLIC
>>> +
>>> +config S390X_LEGACY_CPUS
>>> +    bool
>>> +    default y
>>> +    depends on S390X
>>> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
>>> index efb508cd2e..ffae95dcb3 100644
>>> --- a/target/s390x/cpu_models.c
>>> +++ b/target/s390x/cpu_models.c
>>> @@ -22,6 +22,7 @@
>>>   #include "qemu/module.h"
>>>   #include "qemu/hw-version.h"
>>>   #include "qemu/qemu-print.h"
>>> +#include CONFIG_DEVICES
>>>   #ifndef CONFIG_USER_ONLY
>>>   #include "sysemu/sysemu.h"
>>>   #include "target/s390x/kvm/pv.h"
>>> @@ -47,6 +48,7 @@
>>>    * generation 15 one base feature and one optional feature have 
>>> been deprecated.
>>>    */
>>>   static S390CPUDef s390_cpu_defs[] = {
>>> +#ifdef CONFIG_S390X_LEGACY_CPUS
>>
>> ... here :)
> 
> Can do ... let's just hope that the link is stable in the course of time!

Else we'll use an archived version.

>>>       CPUDEF_INIT(0x2064, 7, 1, 38, 0x00000000U, "z900", "IBM zSeries 
>>> 900 GA1"),
>>>       CPUDEF_INIT(0x2064, 7, 2, 38, 0x00000000U, "z900.2", "IBM 
>>> zSeries 900 GA2"),
>>>       CPUDEF_INIT(0x2064, 7, 3, 38, 0x00000000U, "z900.3", "IBM 
>>> zSeries 900 GA3"),
>>> @@ -78,6 +80,7 @@ static S390CPUDef s390_cpu_defs[] = {
>>>       CPUDEF_INIT(0x2964, 13, 1, 47, 0x08000000U, "z13", "IBM z13 GA1"),
>>>       CPUDEF_INIT(0x2964, 13, 2, 47, 0x08000000U, "z13.2", "IBM z13 
>>> GA2"),
>>>       CPUDEF_INIT(0x2965, 13, 2, 47, 0x08000000U, "z13s", "IBM z13s 
>>> GA1"),
>>> +#endif
>>>       CPUDEF_INIT(0x3906, 14, 1, 47, 0x08000000U, "z14", "IBM z14 GA1"),
>>>       CPUDEF_INIT(0x3906, 14, 2, 47, 0x08000000U, "z14.2", "IBM z14 
>>> GA2"),
>>>       CPUDEF_INIT(0x3907, 14, 1, 47, 0x08000000U, "z14ZR1", "IBM z14 
>>> Model ZR1 GA1"),
>>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>>> index 3d0bc3e7f2..7529d2fba8 100644
>>> --- a/hw/s390x/s390-virtio-ccw.c
>>> +++ b/hw/s390x/s390-virtio-ccw.c
>>> @@ -47,6 +47,7 @@
>>>   #include "migration/blocker.h"
>>>   #include "qapi/visitor.h"
>>>   #include "hw/s390x/cpu-topology.h"
>>> +#include CONFIG_DEVICES
>>>   static Error *pv_mig_blocker;
>>> @@ -603,6 +604,8 @@ static void s390_nmi(NMIState *n, int cpu_index, 
>>> Error **errp)
>>>       s390_cpu_restart(S390_CPU(cs));
>>>   }
>>> +#ifdef CONFIG_S390X_LEGACY_CPUS
>>> +
>>>   static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
>>>   {
>>>       /* same logic as in sclp.c */
>>> @@ -623,6 +626,8 @@ static ram_addr_t s390_fixup_ram_size(ram_addr_t sz)
>>>       return newsz;
>>>   }
>>> +#endif
>>> +
>>>   static inline bool machine_get_aes_key_wrap(Object *obj, Error **errp)
>>>   {
>>>       S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
>>> @@ -989,6 +994,8 @@ static void 
>>> ccw_machine_6_1_class_options(MachineClass *mc)
>>>   }
>>>   DEFINE_CCW_MACHINE(6_1, "6.1", false);
>>> +#ifdef CONFIG_S390X_LEGACY_CPUS
>>> +
>>>   static void ccw_machine_6_0_instance_options(MachineState *machine)
>>>   {
>>>       static const S390FeatInit qemu_cpu_feat = { 
>>> S390_FEAT_LIST_QEMU_V6_0 };
>>
>> Should we deprecate machines up to v6.0?
> 
> I'm still hoping that Daniel will be able to get his auto-deprecation 
> patches merged in this cycle - then we shouldn't derive from that, I think.

OK.

> By the way, what's up with your i440fx removal series? ... it would be 
> good to get this finally merged now...?

Igor made some comments that I need to address before respining :/

Re: [PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Christian Borntraeger]

Am 13.06.24 um 19:07 schrieb Thomas Huth:
> Old CPU models are not officially supported anymore by IBM, and for
> downstream builds of QEMU, we would like to be able to disable these
> CPUs in the build. Thus add a CONFIG switch that can be used to
> disable these CPUs (and old machine types that use them by default).
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   If you're interested, the PDF that can be downloaded from
>   https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
>   shows the supported CPUs in a nice diagram

z13 is still supported so the patch needs to be fixed at least.
Furthermore, z14 has the IBC/VAL cabability to behave like a z13,
same for z15. (we do support VAL to N-2)

I fail to see the value of this given how stable this code is.

Re: [PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Thomas Huth]

On 14/06/2024 08.07, Christian Borntraeger wrote:
> 
> 
> Am 13.06.24 um 19:07 schrieb Thomas Huth:
>> Old CPU models are not officially supported anymore by IBM, and for
>> downstream builds of QEMU, we would like to be able to disable these
>> CPUs in the build. Thus add a CONFIG switch that can be used to
>> disable these CPUs (and old machine types that use them by default).
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
>>   If you're interested, the PDF that can be downloaded from
>>   https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
>>   shows the supported CPUs in a nice diagram
> 
> z13 is still supported so the patch needs to be fixed at least.

Oh, drat, I misread the diagram, indeed. 'should have looked at the table 
instead :-/

> Furthermore, z14 has the IBC/VAL cabability to behave like a z13,
> same for z15. (we do support VAL to N-2)

Hmm, so if z13 is still supported, and also has the possibility to do N-2, I 
assume the z114/196 and z12 should still be considered as non-legacy, too?

> I fail to see the value of this given how stable this code is.

As mentioned in the patch description, it's meant for downstream builds of 
QEMU where we'd like to avoid legacy devices and CPUs in the builds (it 
doesn't make sense to have support for e.g. z900 CPUs there).

  Thomas

Re: [PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Christian Borntraeger]

Am 14.06.24 um 09:15 schrieb Thomas Huth:
> On 14/06/2024 08.07, Christian Borntraeger wrote:
>>
>>
>> Am 13.06.24 um 19:07 schrieb Thomas Huth:
>>> Old CPU models are not officially supported anymore by IBM, and for
>>> downstream builds of QEMU, we would like to be able to disable these
>>> CPUs in the build. Thus add a CONFIG switch that can be used to
>>> disable these CPUs (and old machine types that use them by default).
>>>
>>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>>> ---
>>>   If you're interested, the PDF that can be downloaded from
>>>   https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
>>>   shows the supported CPUs in a nice diagram
>>
>> z13 is still supported so the patch needs to be fixed at least.
> 
> Oh, drat, I misread the diagram, indeed. 'should have looked at the table instead :-/
> 
>> Furthermore, z14 has the IBC/VAL cabability to behave like a z13,
>> same for z15. (we do support VAL to N-2)
> 
> Hmm, so if z13 is still supported, and also has the possibility to do N-2, I assume the z114/196 and z12 should still be considered as non-legacy, too?

Yes. z9 and older is no longer relevant (only for people that collect old HW) but the upstream kernel has an minimum requirement for z10 so maybe we still want to support that for testing purposes.
For upstream I prefer to keep the full list but I would be ok to hide those ancient things behind a config switch.

Re: [PATCH] target/s390x: Add a CONFIG switch to disable legacy CPUs

[Thomas Huth]

On 14/06/2024 10.17, Christian Borntraeger wrote:
> 
> 
> Am 14.06.24 um 09:15 schrieb Thomas Huth:
>> On 14/06/2024 08.07, Christian Borntraeger wrote:
>>>
>>>
>>> Am 13.06.24 um 19:07 schrieb Thomas Huth:
>>>> Old CPU models are not officially supported anymore by IBM, and for
>>>> downstream builds of QEMU, we would like to be able to disable these
>>>> CPUs in the build. Thus add a CONFIG switch that can be used to
>>>> disable these CPUs (and old machine types that use them by default).
>>>>
>>>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>>>> ---
>>>>   If you're interested, the PDF that can be downloaded from
>>>>   https://www.ibm.com/support/pages/ibm-mainframe-life-cycle-history
>>>>   shows the supported CPUs in a nice diagram
>>>
>>> z13 is still supported so the patch needs to be fixed at least.
>>
>> Oh, drat, I misread the diagram, indeed. 'should have looked at the table 
>> instead :-/
>>
>>> Furthermore, z14 has the IBC/VAL cabability to behave like a z13,
>>> same for z15. (we do support VAL to N-2)
>>
>> Hmm, so if z13 is still supported, and also has the possibility to do N-2, 
>> I assume the z114/196 and z12 should still be considered as non-legacy, too?
> 
> Yes. z9 and older is no longer relevant (only for people that collect old 
> HW) but the upstream kernel has an minimum requirement for z10 so maybe we 
> still want to support that for testing purposes.

Ok, fair point, kernel support is a good hint, too.

> For upstream I prefer to keep the full list but I would be ok to hide those 
> ancient things behind a config switch.

That's what this patch is trying to do - by default, all CPUs are still 
enabled, you have actively disable the switch to get rid of the old ones.

  Thomas