Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Shalini Chellathurai Saroja]

On 2025-04-28 11:22, Janis Schoetterl-Glausch wrote:
> On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai Saroja wrote:
>> Implement the Service-Call Logical Processor (SCLP) event
>> type Control-Program Identification (CPI) in QEMU. This
>> event is used to send CPI identifiers from the guest to the
>> host. The CPI identifiers are: system type, system name,
>> system level and sysplex name.
>> 
>> System type: operating system of the guest (e.g. "LINUX").
>> System name: user configurable name of the guest (e.g. "TESTVM").
>> System level: distribution and kernel version, if the system type is 
>> Linux
>> (e.g. 0x50e00).
>> Sysplex name: name of the cluster which the guest belongs to (if any)
>> (e.g. "PLEX").
>> 
>> Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>> ---
>>  hw/s390x/event-facility.c         |  2 +
>>  hw/s390x/meson.build              |  1 +
>>  hw/s390x/s390-virtio-ccw.c        | 14 +++++
>>  hw/s390x/sclpcpi.c                | 92 
>> +++++++++++++++++++++++++++++++
>>  include/hw/s390x/event-facility.h | 13 +++++
>>  5 files changed, 122 insertions(+)
>>  create mode 100644 hw/s390x/sclpcpi.c
>> 
>> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
>> index 2b0332c20e..60237b8581 100644
>> --- a/hw/s390x/event-facility.c
>> +++ b/hw/s390x/event-facility.c
>> @@ -4,6 +4,7 @@
>>   *       handles SCLP event types
>>   *          - Signal Quiesce - system power down
>>   *          - ASCII Console Data - VT220 read and write
>> + *          - Control-Program Identification - Send OS data from 
>> guest to host
>>   *
>>   * Copyright IBM, Corp. 2012
>>   *
>> @@ -40,6 +41,7 @@ struct SCLPEventFacility {
>>      SysBusDevice parent_obj;
>>      SCLPEventsBus sbus;
>>      SCLPEvent quiesce, cpu_hotplug;
>> +    SCLPEventCPI cpi;
>>      /* guest's receive mask */
>>      union {
>>          uint32_t receive_mask_pieces[2];
>> diff --git a/hw/s390x/meson.build b/hw/s390x/meson.build
>> index 3bbebfd817..eb7950489c 100644
>> --- a/hw/s390x/meson.build
>> +++ b/hw/s390x/meson.build
>> @@ -13,6 +13,7 @@ s390x_ss.add(files(
>>    's390-skeys.c',
>>    's390-stattrib.c',
>>    'sclp.c',
>> +  'sclpcpi.c',
>>    'sclpcpu.c',
>>    'sclpquiesce.c',
>>    'tod.c',
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 75b32182eb..7f28cbd1de 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -260,6 +260,17 @@ static void s390_create_sclpconsole(SCLPDevice 
>> *sclp,
>>      qdev_realize_and_unref(dev, ev_fac_bus, &error_fatal);
>>  }
>> 
>> +static void s390_create_sclpcpi(SCLPDevice *sclp)
>> +{
>> +    SCLPEventFacility *ef = sclp->event_facility;
>> +    BusState *ev_fac_bus = sclp_get_event_facility_bus(ef);
>> +    DeviceState *dev;
>> +
>> +    dev = qdev_new(TYPE_SCLP_EVENT_CPI);
>> +    object_property_add_child(OBJECT(ef), "sclpcpi", OBJECT(dev));
>> +    qdev_realize_and_unref(dev, ev_fac_bus, &error_fatal);
> 
> I wonder if we should drop this and add control-program-id directly
> on the event facility. I don't see what purpose having the intermediate
> level sclpcpi serves.
> 

Hello Nina,

sclpcpi is the qemu device which handles the SCLP event type 
Control-Program Identification by performing the following.
1. The sclpcpi device indicates to the guest OS that QEMU is able to 
process the event buffers of the SCLP event type Control-Program 
Identification.
2. The sclpcpi device receives the data from the event buffers of the 
SCLP event type Control-Program Identification sent by the guest OS.
The received data is stored in control-program-id, which is the property 
of the device sclpcpi. So, the sclpcpi device cannot be dropped.

In addition, Thomas Huth told that the migration data of a device must 
be stored in the device itself during his review of the previous 
versions of this patch series. So control-program-id cannot be stored in 
the event facility.

It is possible to add the identifiers directly as the properties of 
sclpcpi (eg. system type as shown below) and remove the 
control-program-id.

virsh # qemu-monitor-command vm --pretty 
'{"execute":"qom-list","arguments": {"path": 
"/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
{
   "return": [
     {
       "name": "type",
       "type": "string"
     },
     {
       "name": "parent_bus",
       "type": "link<bus>"
     },
     {
       "name": "realized",
       "type": "bool"
     },
     {
       "name": "hotplugged",
       "type": "bool"
     },
     {
       "name": "hotpluggable",
       "type": "bool"
     },
     {
       "name": "system_type",
       "type": "string"
     },
     {
       "name": "control-program-id",
       "type": "S390ControlProgramId"
     }
   ],
   "id": "libvirt-16"
}

virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get", 
"arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi", 
"property":"system_type"}}'
{
   "return": "LINUX   ",
   "id": "libvirt-17"
}

However, Hendrik Brückner suggested to group the identifiers together 
during the initial discussion of this line item. So, I would prefer to 
leave this as it is. Please let me know if you still think otherwise.

>> +}
> 
> [...]
> 
>> diff --git a/include/hw/s390x/event-facility.h 
>> b/include/hw/s390x/event-facility.h
>> index ff874e792d..ef469e62ae 100644
>> --- a/include/hw/s390x/event-facility.h
>> +++ b/include/hw/s390x/event-facility.h
> 
> [...]
>    I.
>> +struct SCLPEventCPI {
>> +    DeviceState qdev;
>> +    SCLPEvent event;
> 
> I think you should just inherit from SCLPEvent, which in turn inherits
> from DeviceState.
> So without the qdev.
> 

Ok, I will do so. Thank you very much for the review.

>> +};
>> +
>>  #define TYPE_SCLP_EVENT_FACILITY "s390-sclp-event-facility"
>>  typedef struct SCLPEventFacility SCLPEventFacility;
>>  typedef struct SCLPEventFacilityClass SCLPEventFacilityClass;

-- 
Mit freundlichen Grüßen / Kind regards
Shalini Chellathurai Saroja
Software Developer
Linux on IBM Z & KVM Development
IBM Deutschland Research & Development GmbH
Dept 1419, Schoenaicher Str. 220, 71032 Boeblingen
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht 
Stuttgart, HRB 243294

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Nina Schoetterl-Glausch]

On Mon, 2025-05-05 at 08:55 +0200, Shalini Chellathurai Saroja wrote:
> On 2025-04-28 11:22, Janis Schoetterl-Glausch wrote:
> > On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai Saroja wrote:
> > > Implement the Service-Call Logical Processor (SCLP) event
> > > type Control-Program Identification (CPI) in QEMU. This
> > > event is used to send CPI identifiers from the guest to the
> > > host. The CPI identifiers are: system type, system name,
> > > system level and sysplex name.
> > > 
> > > System type: operating system of the guest (e.g. "LINUX").
> > > System name: user configurable name of the guest (e.g. "TESTVM").
> > > System level: distribution and kernel version, if the system type is 
> > > Linux
> > > (e.g. 0x50e00).
> > > Sysplex name: name of the cluster which the guest belongs to (if any)
> > > (e.g. "PLEX").
> > > 
> > > Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
> > > Reviewed-by: Thomas Huth <thuth@redhat.com>
> > > ---
> > >  hw/s390x/event-facility.c         |  2 +
> > >  hw/s390x/meson.build              |  1 +
> > >  hw/s390x/s390-virtio-ccw.c        | 14 +++++
> > >  hw/s390x/sclpcpi.c                | 92 
> > > +++++++++++++++++++++++++++++++
> > >  include/hw/s390x/event-facility.h | 13 +++++
> > >  5 files changed, 122 insertions(+)
> > >  create mode 100644 hw/s390x/sclpcpi.c
> > > 
> > > diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> > > index 2b0332c20e..60237b8581 100644
> > > --- a/hw/s390x/event-facility.c
> > > +++ b/hw/s390x/event-facility.c

[...]

> It is possible to add the identifiers directly as the properties of 
> sclpcpi (eg. system type as shown below) and remove the 
> control-program-id.

This is what I meant, drop it from qom.
> 
> virsh # qemu-monitor-command vm --pretty 
> '{"execute":"qom-list","arguments": {"path": 
> "/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
> {
>    "return": [
>      {
>        "name": "type",
>        "type": "string"
>      },
>      {
>        "name": "parent_bus",
>        "type": "link<bus>"
>      },
>      {
>        "name": "realized",
>        "type": "bool"
>      },
>      {
>        "name": "hotplugged",
>        "type": "bool"
>      },
>      {
>        "name": "hotpluggable",
>        "type": "bool"
>      },
>      {
>        "name": "system_type",
>        "type": "string"
>      },
>      {
>        "name": "control-program-id",
>        "type": "S390ControlProgramId"
>      }
>    ],
>    "id": "libvirt-16"
> }
> 
> virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get", 
> "arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi", 
> "property":"system_type"}}'
> {
>    "return": "LINUX   ",
>    "id": "libvirt-17"
> }
> 
> However, Hendrik Brückner suggested to group the identifiers together 
> during the initial discussion of this line item. So, I would prefer to 

They are grouped together under "sclpcpi", no?

> leave this as it is. Please let me know if you still think otherwise.

I don't have a strong opinion on this, just wanted to mention it and see what other people say.
> 
> > > +}
> > 
> > [...]
> > 
> > > diff --git a/include/hw/s390x/event-facility.h 
> > > b/include/hw/s390x/event-facility.h
> > > index ff874e792d..ef469e62ae 100644
> > > --- a/include/hw/s390x/event-facility.h
> > > +++ b/include/hw/s390x/event-facility.h
> > 
> > [...]
> >    I.
> > > +struct SCLPEventCPI {
> > > +    DeviceState qdev;
> > > +    SCLPEvent event;
> > 
> > I think you should just inherit from SCLPEvent, which in turn inherits
> > from DeviceState.
> > So without the qdev.
> > 
> 
> Ok, I will do so. Thank you very much for the review.
> 
> > > +};
> > > +
> > >  #define TYPE_SCLP_EVENT_FACILITY "s390-sclp-event-facility"
> > >  typedef struct SCLPEventFacility SCLPEventFacility;
> > >  typedef struct SCLPEventFacilityClass SCLPEventFacilityClass;
> 

-- 
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Thomas Huth]

On 06/05/2025 08.48, Nina Schoetterl-Glausch wrote:
> On Mon, 2025-05-05 at 08:55 +0200, Shalini Chellathurai Saroja wrote:
>> On 2025-04-28 11:22, Janis Schoetterl-Glausch wrote:
>>> On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai Saroja wrote:
>>>> Implement the Service-Call Logical Processor (SCLP) event
>>>> type Control-Program Identification (CPI) in QEMU. This
>>>> event is used to send CPI identifiers from the guest to the
>>>> host. The CPI identifiers are: system type, system name,
>>>> system level and sysplex name.
>>>>
>>>> System type: operating system of the guest (e.g. "LINUX").
>>>> System name: user configurable name of the guest (e.g. "TESTVM").
>>>> System level: distribution and kernel version, if the system type is
>>>> Linux
>>>> (e.g. 0x50e00).
>>>> Sysplex name: name of the cluster which the guest belongs to (if any)
>>>> (e.g. "PLEX").
>>>>
>>>> Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
>>>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>>>> ---
>>>>   hw/s390x/event-facility.c         |  2 +
>>>>   hw/s390x/meson.build              |  1 +
>>>>   hw/s390x/s390-virtio-ccw.c        | 14 +++++
>>>>   hw/s390x/sclpcpi.c                | 92
>>>> +++++++++++++++++++++++++++++++
>>>>   include/hw/s390x/event-facility.h | 13 +++++
>>>>   5 files changed, 122 insertions(+)
>>>>   create mode 100644 hw/s390x/sclpcpi.c
>>>>
>>>> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
>>>> index 2b0332c20e..60237b8581 100644
>>>> --- a/hw/s390x/event-facility.c
>>>> +++ b/hw/s390x/event-facility.c
> 
> [...]
> 
>> It is possible to add the identifiers directly as the properties of
>> sclpcpi (eg. system type as shown below) and remove the
>> control-program-id.
> 
> This is what I meant, drop it from qom.
>>
>> virsh # qemu-monitor-command vm --pretty
>> '{"execute":"qom-list","arguments": {"path":
>> "/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
>> {
>>     "return": [
>>       {
>>         "name": "type",
>>         "type": "string"
>>       },
>>       {
>>         "name": "parent_bus",
>>         "type": "link<bus>"
>>       },
>>       {
>>         "name": "realized",
>>         "type": "bool"
>>       },
>>       {
>>         "name": "hotplugged",
>>         "type": "bool"
>>       },
>>       {
>>         "name": "hotpluggable",
>>         "type": "bool"
>>       },
>>       {
>>         "name": "system_type",
>>         "type": "string"
>>       },
>>       {
>>         "name": "control-program-id",
>>         "type": "S390ControlProgramId"
>>       }
>>     ],
>>     "id": "libvirt-16"
>> }
>>
>> virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get",
>> "arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi",
>> "property":"system_type"}}'
>> {
>>     "return": "LINUX   ",
>>     "id": "libvirt-17"
>> }
>>
>> However, Hendrik Brückner suggested to group the identifiers together
>> during the initial discussion of this line item. So, I would prefer to
> 
> They are grouped together under "sclpcpi", no?
> 
>> leave this as it is. Please let me know if you still think otherwise.
> 
> I don't have a strong opinion on this, just wanted to mention it and see what other people say.

I guess it mostly depends on whether there are future plans for using the 
QOM type elsewhere. If this type is supposed to be used in other QAPI calls 
in the future, it makes sense to keep it separate now. If there are no such 
plans, it's maybe easier to integrate the values into sclpcpi directly. 
Hendrik, any opinion from your side?

  Thomas

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Shalini Chellathurai Saroja]

On 2025-05-06 09:48, Thomas Huth wrote:
> On 06/05/2025 08.48, Nina Schoetterl-Glausch wrote:
>> On Mon, 2025-05-05 at 08:55 +0200, Shalini Chellathurai Saroja wrote:
>>> On 2025-04-28 11:22, Janis Schoetterl-Glausch wrote:
>>>> On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai Saroja 
>>>> wrote:
>>>>> Implement the Service-Call Logical Processor (SCLP) event
>>>>> type Control-Program Identification (CPI) in QEMU. This
>>>>> event is used to send CPI identifiers from the guest to the
>>>>> host. The CPI identifiers are: system type, system name,
>>>>> system level and sysplex name.
>>>>> 
>>>>> System type: operating system of the guest (e.g. "LINUX").
>>>>> System name: user configurable name of the guest (e.g. "TESTVM").
>>>>> System level: distribution and kernel version, if the system type 
>>>>> is
>>>>> Linux
>>>>> (e.g. 0x50e00).
>>>>> Sysplex name: name of the cluster which the guest belongs to (if 
>>>>> any)
>>>>> (e.g. "PLEX").
>>>>> 
>>>>> Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
>>>>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>>>>> ---
>>>>>   hw/s390x/event-facility.c         |  2 +
>>>>>   hw/s390x/meson.build              |  1 +
>>>>>   hw/s390x/s390-virtio-ccw.c        | 14 +++++
>>>>>   hw/s390x/sclpcpi.c                | 92
>>>>> +++++++++++++++++++++++++++++++
>>>>>   include/hw/s390x/event-facility.h | 13 +++++
>>>>>   5 files changed, 122 insertions(+)
>>>>>   create mode 100644 hw/s390x/sclpcpi.c
>>>>> 
>>>>> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
>>>>> index 2b0332c20e..60237b8581 100644
>>>>> --- a/hw/s390x/event-facility.c
>>>>> +++ b/hw/s390x/event-facility.c
>> 
>> [...]
>> 
>>> It is possible to add the identifiers directly as the properties of
>>> sclpcpi (eg. system type as shown below) and remove the
>>> control-program-id.
>> 
>> This is what I meant, drop it from qom.

Ok.

>>> 
>>> virsh # qemu-monitor-command vm --pretty
>>> '{"execute":"qom-list","arguments": {"path":
>>> "/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
>>> {
>>>     "return": [
>>>       {
>>>         "name": "type",
>>>         "type": "string"
>>>       },
>>>       {
>>>         "name": "parent_bus",
>>>         "type": "link<bus>"
>>>       },
>>>       {
>>>         "name": "realized",
>>>         "type": "bool"
>>>       },
>>>       {
>>>         "name": "hotplugged",
>>>         "type": "bool"
>>>       },
>>>       {
>>>         "name": "hotpluggable",
>>>         "type": "bool"
>>>       },
>>>       {
>>>         "name": "system_type",
>>>         "type": "string"
>>>       },
>>>       {
>>>         "name": "control-program-id",
>>>         "type": "S390ControlProgramId"
>>>       }
>>>     ],
>>>     "id": "libvirt-16"
>>> }
>>> 
>>> virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get",
>>> "arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi",
>>> "property":"system_type"}}'
>>> {
>>>     "return": "LINUX   ",
>>>     "id": "libvirt-17"
>>> }
>>> 
>>> However, Hendrik Brückner suggested to group the identifiers together
>>> during the initial discussion of this line item. So, I would prefer 
>>> to
>> 
>> They are grouped together under "sclpcpi", no?

Yes.

>> 
>>> leave this as it is. Please let me know if you still think otherwise.
>> 
>> I don't have a strong opinion on this, just wanted to mention it and 
>> see what other people say.
> 
> I guess it mostly depends on whether there are future plans for using
> the QOM type elsewhere. If this type is supposed to be used in other
> QAPI calls in the future, it makes sense to keep it separate now. If
> there are no such plans, it's maybe easier to integrate the values
> into sclpcpi directly. Hendrik, any opinion from your side?
> 
>  Thomas

Hello Hendrik,

I have provided the output of both the options below. Please let me know 
which option do you prefer.

I have incorporated the other comments. So I will be able to send V5 
after your response. Thank you very much!

Option 1: Control-program identifiers set as the properties of sclpcpi:

virsh # qemu-monitor-command vm --pretty 
'{"execute":"qom-list","arguments": {"path": 
"/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
{
   "return": [
     {
[...]
     },
     {
       "name": "system_level",
       "type": "uint64"
     },
     {
       "name": "system_name",
       "type": "string"
     },
     {
       "name": "system_type",
       "type": "string"
     },
     {
       "name": "timestamp",
       "type": "uint64"
     },
     {
       "name": "sysplex_name",
       "type": "string"
     }
   ],
   "id": "libvirt-14"
}

virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get", 
"arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi", 
"property":"system_type"}}'
{
   "return": "LINUX   ",
   "id": "libvirt-18"
}
virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get", 
"arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi", 
"property":"system_name"}}'
{
   "return": "TESTVM  ",
   "id": "libvirt-19"
}
virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get", 
"arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi", 
"property":"sysplex_name"}}'
{
   "return": "PLEX    ",
   "id": "libvirt-20"
}
virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get", 
"arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi", 
"property":"system_level"}}'
{
   "return": 74872343805430528,
   "id": "libvirt-21"
}


Option 2: control-program-id of type S390ControlProgramId set as a 
property of sclpcpi:

virsh # qemu-monitor-command vm --pretty 
'{"execute":"qom-list","arguments": {"path": 
"/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
{
   "return": [
     {
[...]
     },
     {
       "name": "control-program-id",
       "type": "S390ControlProgramId"
     }
   ],
   "id": "libvirt-14"
}

virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get", 
"arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi", 
"property":"control-program-id"}}'
{
   "return": {
     "timestamp": 1746532735581612000,
     "system-level": 74872343805430528,
     "sysplex-name": "PLEX    ",
     "system-name": "TESTVM  ",
     "system-type": "LINUX   "
   },
   "id": "libvirt-22"
}



-- 
Mit freundlichen Grüßen / Kind regards
Shalini Chellathurai Saroja
Software Developer
Linux on IBM Z & KVM Development
IBM Deutschland Research & Development GmbH
Dept 1419, Schoenaicher Str. 220, 71032 Boeblingen
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht 
Stuttgart, HRB 243294

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Hendrik Brueckner]

On Tue, May 06, 2025 at 02:16:18PM +0200, Shalini Chellathurai Saroja wrote:
> On 2025-05-06 09:48, Thomas Huth wrote:
> > On 06/05/2025 08.48, Nina Schoetterl-Glausch wrote:
> > > On Mon, 2025-05-05 at 08:55 +0200, Shalini Chellathurai Saroja wrote:
> > > > On 2025-04-28 11:22, Janis Schoetterl-Glausch wrote:
> > > > > On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai
> > > > > Saroja wrote:
> > > > > > Implement the Service-Call Logical Processor (SCLP) event
> > > > > > type Control-Program Identification (CPI) in QEMU. This
> > > > > > event is used to send CPI identifiers from the guest to the
> > > > > > host. The CPI identifiers are: system type, system name,
> > > > > > system level and sysplex name.
> > > > > > 
> > > > > > System type: operating system of the guest (e.g. "LINUX").
> > > > > > System name: user configurable name of the guest (e.g. "TESTVM").
> > > > > > System level: distribution and kernel version, if the
> > > > > > system type is
> > > > > > Linux
> > > > > > (e.g. 0x50e00).
> > > > > > Sysplex name: name of the cluster which the guest
> > > > > > belongs to (if any)
> > > > > > (e.g. "PLEX").
> > > > > > 
> > > > > > Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
> > > > > > Reviewed-by: Thomas Huth <thuth@redhat.com>
> > > > > > ---
> > > > > >   hw/s390x/event-facility.c         |  2 +
> > > > > >   hw/s390x/meson.build              |  1 +
> > > > > >   hw/s390x/s390-virtio-ccw.c        | 14 +++++
> > > > > >   hw/s390x/sclpcpi.c                | 92
> > > > > > +++++++++++++++++++++++++++++++
> > > > > >   include/hw/s390x/event-facility.h | 13 +++++
> > > > > >   5 files changed, 122 insertions(+)
> > > > > >   create mode 100644 hw/s390x/sclpcpi.c
> > > > > > 
> > > > > > diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> > > > > > index 2b0332c20e..60237b8581 100644
> > > > > > --- a/hw/s390x/event-facility.c
> > > > > > +++ b/hw/s390x/event-facility.c
> > > 
> > > [...]
> > > 
> > > > It is possible to add the identifiers directly as the properties of
> > > > sclpcpi (eg. system type as shown below) and remove the
> > > > control-program-id.
> > > 
> > > This is what I meant, drop it from qom.
> 
> Ok.
> 
> > > > 
> > > > virsh # qemu-monitor-command vm --pretty
> > > > '{"execute":"qom-list","arguments": {"path":
> > > > "/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
> > > > {
> > > >     "return": [
> > > >       {
> > > >         "name": "type",
> > > >         "type": "string"
> > > >       },
> > > >       {
> > > >         "name": "parent_bus",
> > > >         "type": "link<bus>"
> > > >       },
> > > >       {
> > > >         "name": "realized",
> > > >         "type": "bool"
> > > >       },
> > > >       {
> > > >         "name": "hotplugged",
> > > >         "type": "bool"
> > > >       },
> > > >       {
> > > >         "name": "hotpluggable",
> > > >         "type": "bool"
> > > >       },
> > > >       {
> > > >         "name": "system_type",
> > > >         "type": "string"
> > > >       },
> > > >       {
> > > >         "name": "control-program-id",
> > > >         "type": "S390ControlProgramId"
> > > >       }
> > > >     ],
> > > >     "id": "libvirt-16"
> > > > }
> > > > 
> > > > virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get",
> > > > "arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi",
> > > > "property":"system_type"}}'
> > > > {
> > > >     "return": "LINUX   ",
> > > >     "id": "libvirt-17"
> > > > }
> > > > 
> > > > However, Hendrik Brückner suggested to group the identifiers together
> > > > during the initial discussion of this line item. So, I would
> > > > prefer to
> > > 
> > > They are grouped together under "sclpcpi", no?
> 
> Yes.
> 
> > > 
> > > > leave this as it is. Please let me know if you still think otherwise.
> > > 
> > > I don't have a strong opinion on this, just wanted to mention it and
> > > see what other people say.
> > 
> > I guess it mostly depends on whether there are future plans for using
> > the QOM type elsewhere. If this type is supposed to be used in other
> > QAPI calls in the future, it makes sense to keep it separate now. If
> > there are no such plans, it's maybe easier to integrate the values
> > into sclpcpi directly. Hendrik, any opinion from your side?
> > 
> >  Thomas
> 
> Hello Hendrik,
> 
> I have provided the output of both the options below. Please let me know
> which option do you prefer.
> 
> I have incorporated the other comments. So I will be able to send V5 after
> your response. Thank you very much!
> 
> Option 1: Control-program identifiers set as the properties of sclpcpi:
> 
> virsh # qemu-monitor-command vm --pretty '{"execute":"qom-list","arguments":
> {"path": "/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
> {
>   "return": [
>     {
> [...]
>     },
>     {
>       "name": "system_level",
>       "type": "uint64"
>     },
>     {
>       "name": "system_name",
>       "type": "string"
>     },
>     {
>       "name": "system_type",
>       "type": "string"
>     },
>     {
>       "name": "timestamp",
>       "type": "uint64"
>     },
>     {
>       "name": "sysplex_name",
>       "type": "string"
>     }
>   ],
>   "id": "libvirt-14"
> }

I would vote for Option 1 as this seems to be a bit more natural from
an object model.  There is not much impact for the upcoming changes
to consume this information.

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Shalini Chellathurai Saroja]

On 2025-05-23 14:07, Hendrik Brueckner wrote:
> On Tue, May 06, 2025 at 02:16:18PM +0200, Shalini Chellathurai Saroja 
> wrote:
>> On 2025-05-06 09:48, Thomas Huth wrote:
>> > On 06/05/2025 08.48, Nina Schoetterl-Glausch wrote:
>> > > On Mon, 2025-05-05 at 08:55 +0200, Shalini Chellathurai Saroja wrote:
>> > > > On 2025-04-28 11:22, Janis Schoetterl-Glausch wrote:
>> > > > > On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai
>> > > > > Saroja wrote:
>> > > > > > Implement the Service-Call Logical Processor (SCLP) event
>> > > > > > type Control-Program Identification (CPI) in QEMU. This
>> > > > > > event is used to send CPI identifiers from the guest to the
>> > > > > > host. The CPI identifiers are: system type, system name,
>> > > > > > system level and sysplex name.
>> > > > > >
>> > > > > > System type: operating system of the guest (e.g. "LINUX").
>> > > > > > System name: user configurable name of the guest (e.g. "TESTVM").
>> > > > > > System level: distribution and kernel version, if the
>> > > > > > system type is
>> > > > > > Linux
>> > > > > > (e.g. 0x50e00).
>> > > > > > Sysplex name: name of the cluster which the guest
>> > > > > > belongs to (if any)
>> > > > > > (e.g. "PLEX").
>> > > > > >
>> > > > > > Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
>> > > > > > Reviewed-by: Thomas Huth <thuth@redhat.com>
>> > > > > > ---
>> > > > > >   hw/s390x/event-facility.c         |  2 +
>> > > > > >   hw/s390x/meson.build              |  1 +
>> > > > > >   hw/s390x/s390-virtio-ccw.c        | 14 +++++
>> > > > > >   hw/s390x/sclpcpi.c                | 92
>> > > > > > +++++++++++++++++++++++++++++++
>> > > > > >   include/hw/s390x/event-facility.h | 13 +++++
>> > > > > >   5 files changed, 122 insertions(+)
>> > > > > >   create mode 100644 hw/s390x/sclpcpi.c
>> > > > > >
>> > > > > > diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
>> > > > > > index 2b0332c20e..60237b8581 100644
>> > > > > > --- a/hw/s390x/event-facility.c
>> > > > > > +++ b/hw/s390x/event-facility.c
>> > >
>> > > [...]
>> > >
>> > > > It is possible to add the identifiers directly as the properties of
>> > > > sclpcpi (eg. system type as shown below) and remove the
>> > > > control-program-id.
>> > >
>> > > This is what I meant, drop it from qom.
>> 
>> Ok.
>> 
>> > > >
>> > > > virsh # qemu-monitor-command vm --pretty
>> > > > '{"execute":"qom-list","arguments": {"path":
>> > > > "/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
>> > > > {
>> > > >     "return": [
>> > > >       {
>> > > >         "name": "type",
>> > > >         "type": "string"
>> > > >       },
>> > > >       {
>> > > >         "name": "parent_bus",
>> > > >         "type": "link<bus>"
>> > > >       },
>> > > >       {
>> > > >         "name": "realized",
>> > > >         "type": "bool"
>> > > >       },
>> > > >       {
>> > > >         "name": "hotplugged",
>> > > >         "type": "bool"
>> > > >       },
>> > > >       {
>> > > >         "name": "hotpluggable",
>> > > >         "type": "bool"
>> > > >       },
>> > > >       {
>> > > >         "name": "system_type",
>> > > >         "type": "string"
>> > > >       },
>> > > >       {
>> > > >         "name": "control-program-id",
>> > > >         "type": "S390ControlProgramId"
>> > > >       }
>> > > >     ],
>> > > >     "id": "libvirt-16"
>> > > > }
>> > > >
>> > > > virsh # qemu-monitor-command vm --pretty '{"execute":"qom-get",
>> > > > "arguments":{"path":"/machine/sclp/s390-sclp-event-facility/sclpcpi",
>> > > > "property":"system_type"}}'
>> > > > {
>> > > >     "return": "LINUX   ",
>> > > >     "id": "libvirt-17"
>> > > > }
>> > > >
>> > > > However, Hendrik Brückner suggested to group the identifiers together
>> > > > during the initial discussion of this line item. So, I would
>> > > > prefer to
>> > >
>> > > They are grouped together under "sclpcpi", no?
>> 
>> Yes.
>> 
>> > >
>> > > > leave this as it is. Please let me know if you still think otherwise.
>> > >
>> > > I don't have a strong opinion on this, just wanted to mention it and
>> > > see what other people say.
>> >
>> > I guess it mostly depends on whether there are future plans for using
>> > the QOM type elsewhere. If this type is supposed to be used in other
>> > QAPI calls in the future, it makes sense to keep it separate now. If
>> > there are no such plans, it's maybe easier to integrate the values
>> > into sclpcpi directly. Hendrik, any opinion from your side?
>> >
>> >  Thomas
>> 
>> Hello Hendrik,
>> 
>> I have provided the output of both the options below. Please let me 
>> know
>> which option do you prefer.
>> 
>> I have incorporated the other comments. So I will be able to send V5 
>> after
>> your response. Thank you very much!
>> 
>> Option 1: Control-program identifiers set as the properties of 
>> sclpcpi:
>> 
>> virsh # qemu-monitor-command vm --pretty 
>> '{"execute":"qom-list","arguments":
>> {"path": "/machine/sclp/s390-sclp-event-facility/sclpcpi"}}'
>> {
>>   "return": [
>>     {
>> [...]
>>     },
>>     {
>>       "name": "system_level",
>>       "type": "uint64"
>>     },
>>     {
>>       "name": "system_name",
>>       "type": "string"
>>     },
>>     {
>>       "name": "system_type",
>>       "type": "string"
>>     },
>>     {
>>       "name": "timestamp",
>>       "type": "uint64"
>>     },
>>     {
>>       "name": "sysplex_name",
>>       "type": "string"
>>     }
>>   ],
>>   "id": "libvirt-14"
>> }
> 
> I would vote for Option 1 as this seems to be a bit more natural from
> an object model.  There is not much impact for the upcoming changes
> to consume this information.

Hello Hendrik,

Ok, I will incorporate this and will send the next version of this 
series.
Thank you very much!

-- 
Mit freundlichen Grüßen / Kind regards
Shalini Chellathurai Saroja
Software Developer
Linux on IBM Z & KVM Development
IBM Deutschland Research & Development GmbH
Dept 1419, Schoenaicher Str. 220, 71032 Boeblingen
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht 
Stuttgart, HRB 243294

[PATCH v4 0/4] Add SCLP event type CPI

[Shalini Chellathurai Saroja]

Implement the Service-Call Logical Processor (SCLP) event
type Control-Program Identification (CPI) in QEMU.

Changed since v3:
- Add QOM object sclpcpi from ccw_init()
- Add SCLPEventCPI state to store the CPI data in the sclpcpi device
- Other minor changes

Changed since v2:
- Add SPDX license tag in the new file hw/s390x/sclpcpi.c
- Store the control-program Identification data in the sclpcpi device
- Update the description of CPI attributes
- Use ldq_be_p() intead of be64_to_cpu()
- Return the CPI attribute system-level as an integer in QMP
- Add compat handling for backward migration
- Other minor changes

Shalini Chellathurai Saroja (4):
  hw/s390x: add SCLP event type CPI
  hw/s390x: add Control-Program Identification to QOM
  hw/s390x: support migration of CPI data
  hw/s390x: compat handling for backward migration

 hw/s390x/event-facility.c          |   2 +
 hw/s390x/meson.build               |   1 +
 hw/s390x/s390-virtio-ccw.c         |  22 ++++
 hw/s390x/sclpcpi.c                 | 156 +++++++++++++++++++++++++++++
 include/hw/s390x/event-facility.h  |  22 ++++
 include/hw/s390x/s390-virtio-ccw.h |   1 +
 qapi/machine.json                  |  58 +++++++++++
 7 files changed, 262 insertions(+)
 create mode 100644 hw/s390x/sclpcpi.c

-- 
2.49.0

[PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Shalini Chellathurai Saroja]

Implement the Service-Call Logical Processor (SCLP) event
type Control-Program Identification (CPI) in QEMU. This
event is used to send CPI identifiers from the guest to the
host. The CPI identifiers are: system type, system name,
system level and sysplex name.

System type: operating system of the guest (e.g. "LINUX").
System name: user configurable name of the guest (e.g. "TESTVM").
System level: distribution and kernel version, if the system type is Linux
(e.g. 0x50e00).
Sysplex name: name of the cluster which the guest belongs to (if any)
(e.g. "PLEX").

Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 hw/s390x/event-facility.c         |  2 +
 hw/s390x/meson.build              |  1 +
 hw/s390x/s390-virtio-ccw.c        | 14 +++++
 hw/s390x/sclpcpi.c                | 92 +++++++++++++++++++++++++++++++
 include/hw/s390x/event-facility.h | 13 +++++
 5 files changed, 122 insertions(+)
 create mode 100644 hw/s390x/sclpcpi.c

diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
index 2b0332c20e..60237b8581 100644
--- a/hw/s390x/event-facility.c
+++ b/hw/s390x/event-facility.c
@@ -4,6 +4,7 @@
  *       handles SCLP event types
  *          - Signal Quiesce - system power down
  *          - ASCII Console Data - VT220 read and write
+ *          - Control-Program Identification - Send OS data from guest to host
  *
  * Copyright IBM, Corp. 2012
  *
@@ -40,6 +41,7 @@ struct SCLPEventFacility {
     SysBusDevice parent_obj;
     SCLPEventsBus sbus;
     SCLPEvent quiesce, cpu_hotplug;
+    SCLPEventCPI cpi;
     /* guest's receive mask */
     union {
         uint32_t receive_mask_pieces[2];
diff --git a/hw/s390x/meson.build b/hw/s390x/meson.build
index 3bbebfd817..eb7950489c 100644
--- a/hw/s390x/meson.build
+++ b/hw/s390x/meson.build
@@ -13,6 +13,7 @@ s390x_ss.add(files(
   's390-skeys.c',
   's390-stattrib.c',
   'sclp.c',
+  'sclpcpi.c',
   'sclpcpu.c',
   'sclpquiesce.c',
   'tod.c',
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 75b32182eb..7f28cbd1de 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -260,6 +260,17 @@ static void s390_create_sclpconsole(SCLPDevice *sclp,
     qdev_realize_and_unref(dev, ev_fac_bus, &error_fatal);
 }
 
+static void s390_create_sclpcpi(SCLPDevice *sclp)
+{
+    SCLPEventFacility *ef = sclp->event_facility;
+    BusState *ev_fac_bus = sclp_get_event_facility_bus(ef);
+    DeviceState *dev;
+
+    dev = qdev_new(TYPE_SCLP_EVENT_CPI);
+    object_property_add_child(OBJECT(ef), "sclpcpi", OBJECT(dev));
+    qdev_realize_and_unref(dev, ev_fac_bus, &error_fatal);
+}
+
 static void ccw_init(MachineState *machine)
 {
     MachineClass *mc = MACHINE_GET_CLASS(machine);
@@ -323,6 +334,9 @@ static void ccw_init(MachineState *machine)
 
     /* init the TOD clock */
     s390_init_tod();
+
+    /* init SCLP event Control-Program Identification */
+    s390_create_sclpcpi(ms->sclp);
 }
 
 static void s390_cpu_plug(HotplugHandler *hotplug_dev,
diff --git a/hw/s390x/sclpcpi.c b/hw/s390x/sclpcpi.c
new file mode 100644
index 0000000000..13589459b1
--- /dev/null
+++ b/hw/s390x/sclpcpi.c
@@ -0,0 +1,92 @@
+ /*
+  * SPDX-License-Identifier: GPL-2.0-or-later
+  *
+  * SCLP event type 11 - Control-Program Identification (CPI):
+  *    CPI is used to send program identifiers from the guest to the
+  *    Service-Call Logical Processor (SCLP). It is not sent by the SCLP.
+  *    Please refer S390ControlProgramId QOM-type description for details
+  *    on the contents of the CPI.
+  *
+  * Copyright IBM, Corp. 2024
+  *
+  * Authors:
+  *  Shalini Chellathurai Saroja <shalini@linux.ibm.com>
+  *
+  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
+  * option) any later version.  See the COPYING file in the top-level directory.
+  *
+  */
+
+#include "qemu/osdep.h"
+#include "hw/s390x/event-facility.h"
+
+typedef struct Data {
+    uint8_t id_format;
+    uint8_t reserved0;
+    uint8_t system_type[8];
+    uint64_t reserved1;
+    uint8_t system_name[8];
+    uint64_t reserved2;
+    uint64_t system_level;
+    uint64_t reserved3;
+    uint8_t sysplex_name[8];
+    uint8_t reserved4[16];
+} QEMU_PACKED Data;
+
+typedef struct ControlProgramIdMsg {
+    EventBufferHeader ebh;
+    Data data;
+} QEMU_PACKED ControlProgramIdMsg;
+
+static bool can_handle_event(uint8_t type)
+{
+    return type == SCLP_EVENT_CTRL_PGM_ID;
+}
+
+static sccb_mask_t send_mask(void)
+{
+    return 0;
+}
+
+/* Enable SCLP to accept buffers of event type CPI from the control-program. */
+static sccb_mask_t receive_mask(void)
+{
+    return SCLP_EVENT_MASK_CTRL_PGM_ID;
+}
+
+static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
+{
+    ControlProgramIdMsg *cpim = container_of(evt_buf_hdr, ControlProgramIdMsg,
+                                             ebh);
+
+    cpim->ebh.flags = SCLP_EVENT_BUFFER_ACCEPTED;
+    return SCLP_RC_NORMAL_COMPLETION;
+}
+
+static void cpi_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
+
+    dc->user_creatable = false;
+
+    k->can_handle_event = can_handle_event;
+    k->get_send_mask = send_mask;
+    k->get_receive_mask = receive_mask;
+    k->write_event_data = write_event_data;
+}
+
+static const TypeInfo sclp_cpi_info = {
+    .name          = TYPE_SCLP_EVENT_CPI,
+    .parent        = TYPE_SCLP_EVENT,
+    .instance_size = sizeof(SCLPEventCPI),
+    .class_init    = cpi_class_init,
+};
+
+static void sclp_cpi_register_types(void)
+{
+    type_register_static(&sclp_cpi_info);
+}
+
+type_init(sclp_cpi_register_types)
+
diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
index ff874e792d..ef469e62ae 100644
--- a/include/hw/s390x/event-facility.h
+++ b/include/hw/s390x/event-facility.h
@@ -25,6 +25,7 @@
 #define SCLP_EVENT_MESSAGE                      0x02
 #define SCLP_EVENT_CONFIG_MGT_DATA              0x04
 #define SCLP_EVENT_PMSGCMD                      0x09
+#define SCLP_EVENT_CTRL_PGM_ID                  0x0b
 #define SCLP_EVENT_ASCII_CONSOLE_DATA           0x1a
 #define SCLP_EVENT_SIGNAL_QUIESCE               0x1d
 
@@ -35,6 +36,7 @@
 #define SCLP_EVENT_MASK_MSG             SCLP_EVMASK(SCLP_EVENT_MESSAGE)
 #define SCLP_EVENT_MASK_CONFIG_MGT_DATA SCLP_EVMASK(SCLP_EVENT_CONFIG_MGT_DATA)
 #define SCLP_EVENT_MASK_PMSGCMD         SCLP_EVMASK(SCLP_EVENT_PMSGCMD)
+#define SCLP_EVENT_MASK_CTRL_PGM_ID     SCLP_EVMASK(SCLP_EVENT_CTRL_PGM_ID)
 #define SCLP_EVENT_MASK_MSG_ASCII       SCLP_EVMASK(SCLP_EVENT_ASCII_CONSOLE_DATA)
 #define SCLP_EVENT_MASK_SIGNAL_QUIESCE  SCLP_EVMASK(SCLP_EVENT_SIGNAL_QUIESCE)
 
@@ -191,6 +193,17 @@ struct SCLPEventClass {
     bool (*can_handle_event)(uint8_t type);
 };
 
+#define TYPE_SCLP_EVENT_CPI "sclpcpi"
+typedef struct SCLPEventCPIClass SCLPEventCPIClass;
+typedef struct SCLPEventCPI SCLPEventCPI;
+OBJECT_DECLARE_TYPE(SCLPEventCPI, SCLPEventCPIClass,
+                    SCLP_EVENT_CPI)
+
+struct SCLPEventCPI {
+    DeviceState qdev;
+    SCLPEvent event;
+};
+
 #define TYPE_SCLP_EVENT_FACILITY "s390-sclp-event-facility"
 typedef struct SCLPEventFacility SCLPEventFacility;
 typedef struct SCLPEventFacilityClass SCLPEventFacilityClass;
-- 
2.49.0

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Janis Schoetterl-Glausch]

On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai Saroja wrote:
> Implement the Service-Call Logical Processor (SCLP) event
> type Control-Program Identification (CPI) in QEMU. This
> event is used to send CPI identifiers from the guest to the
> host. The CPI identifiers are: system type, system name,
> system level and sysplex name.
> 
> System type: operating system of the guest (e.g. "LINUX").
> System name: user configurable name of the guest (e.g. "TESTVM").
> System level: distribution and kernel version, if the system type is Linux
> (e.g. 0x50e00).
> Sysplex name: name of the cluster which the guest belongs to (if any)
> (e.g. "PLEX").
> 
> Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
>  hw/s390x/event-facility.c         |  2 +
>  hw/s390x/meson.build              |  1 +
>  hw/s390x/s390-virtio-ccw.c        | 14 +++++
>  hw/s390x/sclpcpi.c                | 92 +++++++++++++++++++++++++++++++
>  include/hw/s390x/event-facility.h | 13 +++++
>  5 files changed, 122 insertions(+)
>  create mode 100644 hw/s390x/sclpcpi.c
> 
> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> index 2b0332c20e..60237b8581 100644
> --- a/hw/s390x/event-facility.c
> +++ b/hw/s390x/event-facility.c
> @@ -4,6 +4,7 @@
>   *       handles SCLP event types
>   *          - Signal Quiesce - system power down
>   *          - ASCII Console Data - VT220 read and write
> + *          - Control-Program Identification - Send OS data from guest to host
>   *
>   * Copyright IBM, Corp. 2012
>   *
> @@ -40,6 +41,7 @@ struct SCLPEventFacility {
>      SysBusDevice parent_obj;
>      SCLPEventsBus sbus;
>      SCLPEvent quiesce, cpu_hotplug;
> +    SCLPEventCPI cpi;
>      /* guest's receive mask */
>      union {
>          uint32_t receive_mask_pieces[2];
> diff --git a/hw/s390x/meson.build b/hw/s390x/meson.build
> index 3bbebfd817..eb7950489c 100644
> --- a/hw/s390x/meson.build
> +++ b/hw/s390x/meson.build
> @@ -13,6 +13,7 @@ s390x_ss.add(files(
>    's390-skeys.c',
>    's390-stattrib.c',
>    'sclp.c',
> +  'sclpcpi.c',
>    'sclpcpu.c',
>    'sclpquiesce.c',
>    'tod.c',
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 75b32182eb..7f28cbd1de 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -260,6 +260,17 @@ static void s390_create_sclpconsole(SCLPDevice *sclp,
>      qdev_realize_and_unref(dev, ev_fac_bus, &error_fatal);
>  }
>  
> +static void s390_create_sclpcpi(SCLPDevice *sclp)
> +{
> +    SCLPEventFacility *ef = sclp->event_facility;
> +    BusState *ev_fac_bus = sclp_get_event_facility_bus(ef);
> +    DeviceState *dev;
> +
> +    dev = qdev_new(TYPE_SCLP_EVENT_CPI);
> +    object_property_add_child(OBJECT(ef), "sclpcpi", OBJECT(dev));
> +    qdev_realize_and_unref(dev, ev_fac_bus, &error_fatal);

I wonder if we should drop this and add control-program-id directly
on the event facility. I don't see what purpose having the intermediate
level sclpcpi serves.

> +}

[...]

> diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
> index ff874e792d..ef469e62ae 100644
> --- a/include/hw/s390x/event-facility.h
> +++ b/include/hw/s390x/event-facility.h

[...]
   I. 
> +struct SCLPEventCPI {
> +    DeviceState qdev;
> +    SCLPEvent event;

I think you should just inherit from SCLPEvent, which in turn inherits from DeviceState.
So without the qdev.

> +};
> +
>  #define TYPE_SCLP_EVENT_FACILITY "s390-sclp-event-facility"
>  typedef struct SCLPEventFacility SCLPEventFacility;
>  typedef struct SCLPEventFacilityClass SCLPEventFacilityClass;

-- 
IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Wolfgang Wendt Geschäftsführung: David Faller Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB
243294

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Nina Schoetterl-Glausch]

On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai Saroja wrote:
> Implement the Service-Call Logical Processor (SCLP) event
> type Control-Program Identification (CPI) in QEMU. This
> event is used to send CPI identifiers from the guest to the
> host. The CPI identifiers are: system type, system name,
> system level and sysplex name.
> 
> System type: operating system of the guest (e.g. "LINUX").
> System name: user configurable name of the guest (e.g. "TESTVM").
> System level: distribution and kernel version, if the system type is Linux
> (e.g. 0x50e00).
> Sysplex name: name of the cluster which the guest belongs to (if any)
> (e.g. "PLEX").
> 
> Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
>  hw/s390x/event-facility.c         |  2 +
>  hw/s390x/meson.build              |  1 +
>  hw/s390x/s390-virtio-ccw.c        | 14 +++++
>  hw/s390x/sclpcpi.c                | 92 +++++++++++++++++++++++++++++++
>  include/hw/s390x/event-facility.h | 13 +++++
>  5 files changed, 122 insertions(+)
>  create mode 100644 hw/s390x/sclpcpi.c

[...]


>  static void s390_cpu_plug(HotplugHandler *hotplug_dev,
> diff --git a/hw/s390x/sclpcpi.c b/hw/s390x/sclpcpi.c
> new file mode 100644
> index 0000000000..13589459b1
> --- /dev/null
> +++ b/hw/s390x/sclpcpi.c

[...]

> +static void cpi_class_init(ObjectClass *klass, void *data)

Should be 'const void *data'.

> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
> +
> +    dc->user_creatable = false;
> +
> +    k->can_handle_event = can_handle_event;
> +    k->get_send_mask = send_mask;
> +    k->get_receive_mask = receive_mask;
> +    k->write_event_data = write_event_data;
> +}

[...]

-- 
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294

Re: [PATCH v4 1/4] hw/s390x: add SCLP event type CPI

[Shalini Chellathurai Saroja]

On 2025-04-29 11:20, Nina Schoetterl-Glausch wrote:
> On Thu, 2025-04-10 at 17:09 +0200, Shalini Chellathurai Saroja wrote:
>> Implement the Service-Call Logical Processor (SCLP) event
>> type Control-Program Identification (CPI) in QEMU. This
>> event is used to send CPI identifiers from the guest to the
>> host. The CPI identifiers are: system type, system name,
>> system level and sysplex name.
>> 
>> System type: operating system of the guest (e.g. "LINUX").
>> System name: user configurable name of the guest (e.g. "TESTVM").
>> System level: distribution and kernel version, if the system type is 
>> Linux
>> (e.g. 0x50e00).
>> Sysplex name: name of the cluster which the guest belongs to (if any)
>> (e.g. "PLEX").
>> 
>> Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>> ---
>>  hw/s390x/event-facility.c         |  2 +
>>  hw/s390x/meson.build              |  1 +
>>  hw/s390x/s390-virtio-ccw.c        | 14 +++++
>>  hw/s390x/sclpcpi.c                | 92 
>> +++++++++++++++++++++++++++++++
>>  include/hw/s390x/event-facility.h | 13 +++++
>>  5 files changed, 122 insertions(+)
>>  create mode 100644 hw/s390x/sclpcpi.c
> 
> [...]
> 
> 
>>  static void s390_cpu_plug(HotplugHandler *hotplug_dev,
>> diff --git a/hw/s390x/sclpcpi.c b/hw/s390x/sclpcpi.c
>> new file mode 100644
>> index 0000000000..13589459b1
>> --- /dev/null
>> +++ b/hw/s390x/sclpcpi.c
> 
> [...]
> 
>> +static void cpi_class_init(ObjectClass *klass, void *data)
> 
> Should be 'const void *data'.
> 

Ok, thank you.

>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>> +    SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
>> +
>> +    dc->user_creatable = false;
>> +
>> +    k->can_handle_event = can_handle_event;
>> +    k->get_send_mask = send_mask;
>> +    k->get_receive_mask = receive_mask;
>> +    k->write_event_data = write_event_data;
>> +}
> 
> [...]

-- 
Mit freundlichen Grüßen / Kind regards
Shalini Chellathurai Saroja
Software Developer
Linux on IBM Z & KVM Development
IBM Deutschland Research & Development GmbH
Dept 1419, Schoenaicher Str. 220, 71032 Boeblingen
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht 
Stuttgart, HRB 243294