[PATCH v10 0/9] s390x: CPU Topology

Pierre Morel
2022-10-12T16:21:34Z

Hi,

The implementation of the CPU Topology in QEMU has been drastically
modified since the last patch series and the number of LOCs has been
greatly reduced.

1) Unnecessary objects have been removed, only a single S390Topology
object is created to support migration and reset.

2) The introduction of drawers and books is deferred to a later version.

3) A new property, topology-disable, is added for new machines for test
purpose and migration to/from a host without facility 11 from/to a
host with the facility 11.

Also a documentation has been added to the series.

To use the QEMU patches, you will need Linux V6-rc1 or newer,
or use the following Linux mainline patches:

f5ecfee94493 2022-07-20 KVM: s390: resetting the Topology-Change-Report
24fe0195bc19 2022-07-20 KVM: s390: guest support for topology function
0130337ec45b 2022-07-20 KVM: s390: Cleanup ipte lock access and SIIF fac..

Currently this code is for KVM only, I have no idea if it is interesting
to provide a TCG patch. If ever it will be done in another series.

To have a better understanding of the S390x CPU Topology and its
implementation in QEMU you can have a look at the documentation in the
last patch of this series.

The admin will want to match the host and the guest topology, taking
into account that the guest does not recognize multithreading.
Consequently, two vCPU assigned to threads of the same real CPU should
preferably be assigned to the same socket of the guest machine.

Regards,
Pierre

Pierre Morel (9):
s390x/cpu topology: core_id sets s390x CPU topology
s390x/cpu topology: reporting the CPU topology to the guest
s390x/cpu_topology: resetting the Topology-Change-Report
s390x/cpu_topology: CPU topology migration
target/s390x: interception of PTF instruction
s390x/cpu topology: add topology-disable machine property
s390x/cpu topology: add max_threads machine class attribute
s390x/cpu_topology: activating CPU topology
docs/s390x: document s390x cpu topology

docs/system/s390x/cpu_topology.rst | 80 +++++++++
include/hw/boards.h | 3 +
include/hw/s390x/cpu-topology.h | 65 +++++++
include/hw/s390x/s390-virtio-ccw.h | 9 +
target/s390x/cpu.h | 50 ++++++
target/s390x/kvm/kvm_s390x.h | 1 +
hw/core/machine.c | 5 +
hw/s390x/cpu-topology.c | 279 +++++++++++++++++++++++++++++
hw/s390x/s390-virtio-ccw.c | 85 ++++++++-
target/s390x/cpu-sysemu.c | 15 ++
target/s390x/cpu_topology.c | 109 +++++++++++
target/s390x/kvm/kvm.c | 56 +++++-
util/qemu-config.c | 4 +
hw/s390x/meson.build | 1 +
qemu-options.hx | 6 +-
target/s390x/meson.build | 1 +
16 files changed, 766 insertions(+), 3 deletions(-)
create mode 100644 docs/system/s390x/cpu_topology.rst
create mode 100644 include/hw/s390x/cpu-topology.h
create mode 100644 hw/s390x/cpu-topology.c
create mode 100644 target/s390x/cpu_topology.c

--
2.31.1

Changelog:

- since v9

- remove books and drawers

- remove thread denying and replace with a merge
of cores * threads to specify the CPUs available
to the guest

- add a class option to avoid topology on older
machines
(Cedric)

- Allocate a SYSIB buffer of the maximal length to
avoid overflow.
(Nico, Janis)

- suppress redundancy of smp parameters in topology
and use directly the machine smp structure

- Early check for topology support
(Cedric)

- since v8

- Linux patches are now mainline

- simplification of the implementation
(Janis)

- Migration, new machine definition
(Thomas)

- Documentation

- since v7

- Coherence with the Linux patch series changes for MTCR get
(Pierre)

- check return values during new CPU creation
(Thomas)

- Improving codding style and argument usages
(Thomas)

- since v6

- Changes on smp args in qemu-options
(Daniel)

- changed comments in machine.jason
(Daniel)

- Added reset
(Janosch)

- since v5

- rebasing on newer QEMU version

- reworked most lines above 80 characters.

- since v4

- Added drawer and books to topology

- Added numa topology

- Added documentation

- since v3

- Added migration
(Thomas)

- Separated STSI instruction from KVM to prepare TCG
(Thomas)

- Take care of endianess to prepare TCG
(Thomas)

- Added comments on STSI CPU container and PFT instruction
(Thomas)

- Moved enabling the instructions as the last patch
(Thomas)