Re: [PATCH v3 2/4] hw/s390x: add Control-Program Identification to QOM

[Nina Schoetterl-Glausch <nsg@linux.ibm.com>]

On Mon, 2025-03-31 at 16:00 +0200, Shalini Chellathurai Saroja wrote:
> Add Control-Program Identification data to the QEMU Object
> Model (QOM), along with the timestamp in which the data was received.
> 
> Example:
> virsh # qemu-monitor-command vm --pretty '{
> "execute": "qom-get",
> "arguments": {
> "path": "/machine/sclp/s390-sclp-event-facility/sclpcpi",
> "property": "control-program-id" }}'
> {
>   "return": {
>     "timestamp": 1742390410685762000,
>     "system-level": 74872343805430528,
>     "sysplex-name": "PLEX ",
>     "system-name": "TESTVM  ",
>     "system-type": "LINUX   "
>   },
>   "id": "libvirt-15"
> }
> 
> Signed-off-by: Shalini Chellathurai Saroja <shalini@linux.ibm.com>
> ---
>  hw/s390x/sclpcpi.c                | 38 ++++++++++++++++++++
>  include/hw/s390x/event-facility.h |  9 +++++
>  qapi/machine.json                 | 58 +++++++++++++++++++++++++++++++
>  3 files changed, 105 insertions(+)
> 
> diff --git a/hw/s390x/sclpcpi.c b/hw/s390x/sclpcpi.c
> index 7ace5dd64e..969c15e43d 100644
> --- a/hw/s390x/sclpcpi.c
> +++ b/hw/s390x/sclpcpi.c
> @@ -57,8 +57,11 @@
>    */
>  
>  #include "qemu/osdep.h"
> +#include "qemu/timer.h"
>  #include "hw/s390x/sclp.h"
>  #include "hw/s390x/event-facility.h"
> +#include "hw/s390x/ebcdic.h"
> +#include "qapi/qapi-visit-machine.h"
>  
>  typedef struct Data {
>      uint8_t id_format;
> @@ -99,10 +102,37 @@ static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
>      ControlProgramIdMsg *cpim = container_of(evt_buf_hdr, ControlProgramIdMsg,
>                                               ebh);
>  
> +    ascii_put(event->cpi.system_type, (char *)cpim->data.system_type, 8);
> +    ascii_put(event->cpi.system_name, (char *)cpim->data.system_name, 8);
> +    ascii_put(event->cpi.sysplex_name, (char *)cpim->data.sysplex_name, 8);
> +    event->cpi.system_level = ldq_be_p(&cpim->data.system_level);
> +    event->cpi.timestamp = qemu_clock_get_ns(QEMU_CLOCK_HOST);
> +
>      cpim->ebh.flags = SCLP_EVENT_BUFFER_ACCEPTED;
>      return SCLP_RC_NORMAL_COMPLETION;
>  }
>  
> +static void get_control_program_id(Object *obj, Visitor *v,
> +                                   const char *name, void *opaque,
> +                                   Error **errp)
> +{
> +    SCLPEvent *event = (SCLPEvent *)(obj);

Do a checked cast with SCLP_EVENT(obj).

> +    S390ControlProgramId *cpi;
> +
> +    cpi = &(S390ControlProgramId){
> +        .system_type = g_strndup((char *) event->cpi.system_type,
> +                                 sizeof(event->cpi.system_type)),
> +        .system_name = g_strndup((char *) event->cpi.system_name,
> +                                 sizeof(event->cpi.system_name)),
> +        .system_level = event->cpi.system_level,
> +        .sysplex_name = g_strndup((char *) event->cpi.sysplex_name,
> +                                  sizeof(event->cpi.sysplex_name)),
> +        .timestamp = event->cpi.timestamp
> +    };
> +
> +    visit_type_S390ControlProgramId(v, name, &cpi, errp);
> +}
> +
>  static void cpi_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
> @@ -114,6 +144,14 @@ static void cpi_class_init(ObjectClass *klass, void *data)
>      k->get_send_mask = send_mask;
>      k->get_receive_mask = receive_mask;
>      k->write_event_data = write_event_data;
> +
> +    object_class_property_add(klass, "control-program-id",
> +                              "S390ControlProgramId",
> +                              get_control_program_id,
> +                              NULL, NULL, NULL);
> +    object_class_property_set_description(klass, "control-program-id",
> +        "Control-program identifiers provide data about the guest "
> +        "operating system");
>  }
>  
>  static const TypeInfo sclp_cpi_info = {
> diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
> index f445d2f9f5..39e589ed44 100644
> --- a/include/hw/s390x/event-facility.h
> +++ b/include/hw/s390x/event-facility.h
> @@ -169,10 +169,19 @@ typedef struct ReadEventData {
>      };
>  } QEMU_PACKED ReadEventData;
>  
> +typedef struct ControlProgramId {
> +    uint8_t system_type[8];
> +    uint8_t system_name[8];
> +    uint64_t system_level;
> +    uint8_t sysplex_name[8];
> +    uint64_t timestamp;
> +} QEMU_PACKED ControlProgramId;
> +
>  struct SCLPEvent {
>      DeviceState qdev;
>      bool event_pending;
>      char *name;
> +    ControlProgramId cpi;

I don't think this should go into SCLPEvent.
Rather SCLPEventFacility or SCLPDevice. Otherwise all events,
so also quiesce and cpu_hotplug have a cpi field.

>  };

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