Re: [PATCH qemu v2 2/3] hw/s390x: add SCLP event type CPI

[shalini <shalini@imap.linux.ibm.com>]

On 2025-03-05 19:04, Thomas Huth wrote:
> On 24/02/2025 13.04, Shalini Chellathurai Saroja wrote:
>> Implement the SCLP event type Control-Program Identification
>> (CPI) in QEMU. This event is used to send CPI identifiers,
>> which provide information about the guest OS to the host.
>> 
>> Save the information obtained from the SCLP CPI event to the
>> QOM along with the timestamp in which the data was received.
>> 
>> Example:
>> virsh # qemu-monitor-command vm --pretty '{
>> "execute":"qom-get","arguments": {
>> "path": "/machine", "property": "s390-control-program_id"}}'
> 
> I guess it should be a "-" instead of a "_" between "program" and "id"?

Hello Thomas,

Thank you very much for the review. Yes, that is correct. I will change 
it.

[...]

>> diff --git a/hw/s390x/sclpcpi.c b/hw/s390x/sclpcpi.c
>> new file mode 100644
>> index 0000000000..f2830d2d57
>> --- /dev/null
>> +++ b/hw/s390x/sclpcpi.c
>> @@ -0,0 +1,105 @@
>> +/*
> 
> scripts/checkpatch.pl recently learnt a new check to mandate SPDX
> license tags now for new files ... so please add one here now!
> 

ok.

[...]

>> +static int write_event_data(SCLPEvent *event, EventBufferHeader 
>> *evt_buf_hdr)
>> +{
>> +    ControlProgramIdMsg *cpi = container_of(evt_buf_hdr, 
>> ControlProgramIdMsg,
>> +                                            ebh);
>> +    S390CcwMachineState *ms = S390_CCW_MACHINE(qdev_get_machine());
>> +
>> +    ascii_put(ms->cpi.system_type, (char *)cpi->data.system_type, 8);
>> +    ascii_put(ms->cpi.system_name, (char *)cpi->data.system_name, 8);
>> +    ascii_put(ms->cpi.sysplex_name, (char *)cpi->data.sysplex_name, 
>> 8);
>> +    ms->cpi.system_level = be64_to_cpu(cpi->data.system_level);
> 
> Can we be confident that system_level is always properly aligned?
> Otherwise it's maybe better to use ldq_be_p() instead?

ok, I will use ldq_be_p() instead.

> 
>  Thomas

-- 
Mit freundlichen Grüßen / Kind regards
Shalini Chellathurai Saroja
Software Developer
Linux on IBM Z & KVM Development
IBM Deutschland Research & Development GmbH
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