qclib

qclib provides a C API for extraction of system information for Linux on z
Systems.
For instance, it will provide the number of CPUs

on the machine (CEC, Central Electronic Complex) layer
on the PR/SM (Processor Resource/Systems Manager) layer, i.e. visible to
LPARs
in z/VM hosts, guests and CPU pools
in KVM hosts and guests

This allows calculating the upper limit of CPU resources a highest level guest
can use.
E.g.: If an LPAR on a z13 provides 4 CPUs to a z/VM hypervisor, and the
hypervisor provides 8 virtual CPUs to a guest, qclib can be used to retrieve
all of these numbers, and it can be concluded that not more capacity than 4
CPUs can be used by the software running in the guest.
qclib uses various interfaces and provides this data through a common and
consistent API (Application Programming Interface), using information provided
by:

STSI (Store System Information) instruction - for more details, refer to
the z/Architecture Principles of Operation (SA22-7832)
STHYI (Store Hypervisor Information) instruction as provided by a z/VM
hypervisor - for more information, refer to z/VM: V6R3 CP Programming
Service (SC24-6179), chapter 'Store Hypervisor Information (STHYI)
Instruction'.
hypfs file system - for more information, refer to 'Device Drivers,
Features, and Commands', chapter 'S/390 hypervisor file system'.


          

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License: BSD-3-Clause
URL: https://github.com/ibm-s390-linux/qclib/archive/refs/tags/2.5.1.tar.gz