Re: [PATCH v5 2/3] hw/s390x: add Control-Program Identification to QOM

[Thomas Huth <thuth@redhat.com>]

On 03/06/2025 15.56, Shalini Chellathurai Saroja wrote:
> Add Control-Program Identification (CPI) data to the QEMU Object
> Model (QOM), along with the timestamp in which the data was received
> as shown below.
...
> diff --git a/qapi/machine.json b/qapi/machine.json
> index 5373e1368c..1f2db68032 100644
> --- a/qapi/machine.json
> +++ b/qapi/machine.json
> @@ -2279,3 +2279,61 @@
>   # Since: 1.2
>   ##
>   { 'command': 'query-cpu-definitions', 'returns': ['CpuDefinitionInfo'] }
> +
> +##
> +# @S390ControlProgramId:
> +#
> +# Control-program identifiers provide data about the guest operating system.
> +# The control-program identifiers are: system type, system name, system level
> +# and sysplex name.
> +#
> +# In Linux, all the control-program identifiers are user configurable. The
> +# system type, system name, and sysplex name use EBCDIC characters from
> +# this set: capital A-Z, 0-9, $, @, #, and blank.  In Linux, the system type,
> +# system name and sysplex name are arbitrary free-form texts.
> +#
> +# In Linux, the 8-byte hexadecimal system-level has the format
> +# 0x<a><b><cc><dd><eeee><ff><gg><hh>, where:
> +# <a>: is one hexadecimal byte, its most significant bit indicates hypervisor
> +# use

  Hi Shalini!

While testing the patches, the above description caused some headache for 
me, but I think it's simply typo here: This is not a hexadecimal byte, it's 
just a nibble / 4-bit digit for this <a>, right? Could you please fix the 
description in the next version of the patch series, please?

  Thanks,
   Thomas


> +# <b>: is one digit that represents Linux distributions as follows
> +# 0: generic Linux
> +# 1: Red Hat Enterprise Linux
> +# 2: SUSE Linux Enterprise Server
> +# 3: Canonical Ubuntu
> +# 4: Fedora
> +# 5: openSUSE Leap
> +# 6: Debian GNU/Linux
> +# 7: Red Hat Enterprise Linux CoreOS
> +# <cc>: are two digits for a distribution-specific encoding of the major version
> +# of the distribution
> +# <dd>: are two digits for a distribution-specific encoding of the minor version
> +# of the distribution
> +# <eeee>: are four digits for the patch level of the distribution
> +# <ff>: are two digits for the major version of the kernel
> +# <gg>: are two digits for the minor version of the kernel
> +# <hh>: are two digits for the stable version of the kernel
> +# (e.g. 74872343805430528, when converted to hex is 0x010a000000060b00). On
> +# machines prior to z16, some of the values are not available to display.
> +#
> +# Sysplex refers to a cluster of logical partitions that communicates and
> +# co-operates with each other.
> +#
> +# @system-type: operating system (e.g. "LINUX   ")
> +#
> +# @system-name: user configurable name of the VM (e.g. "TESTVM  ")
> +#
> +# @system-level: distribution and kernel version in Linux
> +#
> +# @sysplex-name: sysplex which the VM belongs to, if any (e.g. "PLEX ")
> +#
> +# @timestamp: latest update of CPI data in nanoseconds since the UNIX EPOCH
> +#
> +# Since: 10.1
> +##
> +{ 'struct': 'S390ControlProgramId', 'data': {
> +     'system-type': 'str',
> +     'system-name': 'str',
> +     'system-level': 'uint64',
> +     'sysplex-name': 'str',
> +     'timestamp': 'uint64' } }