[PATCH v2 00/14] Nested PAPR API (KVM on PowerVM)

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

There is an existing Nested-HV API to enable nested guests on powernv
machines. However, that is not supported on pseries/PowerVM LPARs.
This patch series implements required hcall interfaces to enable nested
guests with KVM on PowerVM.
Unlike Nested-HV, with this API, entire L2 state is retained by L0
during guest entry/exit and uses pre-defined Guest State Buffer (GSB)
format to communicate guest state between L1 and L2 via L0.

L0 here refers to the phyp/PowerVM, or launching a Qemu TCG L0 with the
newly introduced option cap-nested-papr=true.
L1 refers to the LPAR host on PowerVM or Linux booted on Qemu TCG with
above mentioned option cap-nested-papr=true.
L2 refers to nested guest running on top of L1 using KVM.
No SW changes needed for Qemu running in L1 Linux as well as L2 Kernel.

There is a Linux Kernel side patch series to enable support for Nested
PAPR in L1 and same can be found at below url:

Linux Kernel patch series:
- https://lore.kernel.org/linuxppc-dev/20230914030600.16993-1-jniethe5@gmail.com/

For more details, documentation can be referred in either of patch
series.

There are scripts available to assist in setting up an environment for
testing nested guests at https://github.com/iamjpn/kvm-powervm-test

A tree with this series is available at:
https://github.com/planetharsh/qemu/tree/upstream-kop-1012

Thanks to Michael Neuling, Shivaprasad Bhat, Kautuk Consul, Vaibhav Jain
and Jordan Niethe.

Changelog:

v2:
    - Addressed review comments from Nick on v1 series.
v1:
    - https://lore.kernel.org/qemu-devel/20230906043333.448244-1-harshpb@linux.ibm.com/

Harsh Prateek Bora (14):
  spapr: nested:  move nested part of spapr_get_pate into spapr_nested.c
  spapr: nested: Introduce SpaprMachineStateNested to store related
    info.
  spapr: nested: Document Nested PAPR API
  spapr: nested: Introduce cap-nested-papr for Nested PAPR API
  spapr: nested: register nested-hv api hcalls only for cap-nested-hv
  spapr: nested: Introduce H_GUEST_[GET|SET]_CAPABILITIES hcalls.
  spapr: nested: Introduce H_GUEST_[CREATE|DELETE] hcalls.
  spapr: nested: Introduce H_GUEST_CREATE_VPCU hcall.
  spapr: nested: Initialize the GSB elements lookup table.
  spapr: nested: Introduce H_GUEST_[GET|SET]_STATE hcalls.
  spapr: nested: Use correct source for parttbl info for nested PAPR
    API.
  spapr: nested: rename nested_host_state to nested_hv_host
  spapr: nested: keep nested-hv exit code restricted to its API.
  spapr: nested: Introduce H_GUEST_RUN_VCPU hcall.

 docs/devel/nested-papr.txt      |  500 +++++++++++
 hw/ppc/spapr.c                  |   32 +-
 hw/ppc/spapr_caps.c             |   63 ++
 hw/ppc/spapr_hcall.c            |    2 -
 hw/ppc/spapr_nested.c           | 1439 ++++++++++++++++++++++++++++++-
 include/hw/ppc/spapr.h          |   21 +-
 include/hw/ppc/spapr_cpu_core.h |    7 +-
 include/hw/ppc/spapr_nested.h   |  361 ++++++++
 target/ppc/cpu.h                |    2 +
 9 files changed, 2368 insertions(+), 59 deletions(-)
 create mode 100644 docs/devel/nested-papr.txt

-- 
2.39.3